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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatically switchable sprinkler head for automatically discharging fire extinguishing water by opening a valve against the surrounding temperature rise by a fire and automatically ceasing the water discharge by closing the valve against the surrounding temperature drop by the extinguishment of the fire.
2. Description of the Related Art
In conventional sprinkler heads, the channel connecting the water supply opening of the head connecting part for the fire extinguishing pipe and the water discharge opening at the tip of the head is sealed by a heat sensitive material, which is melted by the heat of the fire, such as a fusible alloy. When the temperature is raised over a predetermined temperature by a fire, the heat sensitive material is melted so that the channel is opened for discharging water.
Therefore, once the channel is opened by the drive of the sprinkler head by the hot air in the fire, the water discharge continues even after the extinguishment of the fire until the water supply from the water source is finished, or the valve is closed manually by a clerk, who confirms the site so that the damage by the water discharge has been considerable.
Accordingly, a sprinkler head, which opens the valve by the temperature rise by a fire so as to automatically discharges water and closes the valve by the temperature drop by the extinguishment of the fire so as to automatically ceases the water discharge, using a bimetal or a shape-memory alloy has been proposed.
Specifically, U.S. Pat. No. 4,553,602, Japanese Unexamined Patent Publication No. 53-48397, and Japanese Unexamined Utility Model Publication No. 54-131800 (based on the priority claim: U.S. Application No. 196641 filed on Nov. 8, 1971) disclose a sprinkler head utilizing a bimetal.
Further, Japanese Unexamined patent Publication No. 60-249978 (based on the priority claim: U.S. application No. 605201 filed on Apr. 30, 1984) and Japanese Unexamined Patent Publication No. 5-123419 disclose a sprinkler head utilizing a shape-memory alloy.
In such a conventional sprinkler head, when the surrounding of the sprinkler head has an ordinary temperature, the bimetal or the shape-memory alloy is maintained in the ordinary temperature shape. In this state, the water discharging path inside the sprinkler head is kept in the closed state directly by the bimetal or the shape-memory alloy in the ordinary temperature state or indirectly via an optional element. When the temperature surrounding the sprinkler head is higher than a predetermined operating temperature, the bimetal deforms into a high temperature shape, or the shape-memory alloy restores the memorized shape. At the time, the water discharging path is opened by the deformed bimetal or restored shape-memory alloy so that the water discharging operation is initiated. Further, when the surrounding of the sprinkler head regains an ordinary temperature after the extinguishment of the fire by the water discharge, the bimetal or the shape-memory alloy deforms to the ordinary temperature shape so as to close the water discharging path.
In summary, in the conventional sprinkler heads, the water discharging path is opened by the bimetal deformation or the restoration of the shape-memory alloy caused by a temperature higher than a predetermined operating temperature.
However, a problem is involved in the bimetal corrosion. That is, the expected deformation cannot be achieved even at the predetermined operating temperature due to the bimetal corrosion so that the sprinkler head cannot be operated.
Further, since the temperature at which a bimetal deforms or a shape-memory alloy restores can be defined only in a range within several ten degrees so that the temperature at which the deformation or the restoration takes place cannot be pinpointed in the range. Therefore, the temperature at which the water discharging path is opened, that is, the sprinkler head starts the operation cannot be determined accurately. For the same reason, when the water discharging path is closed after the water discharge, the temperature at which the water discharging path is closed, that is, the operation of the sprinkler head is ceased cannot be determined accurately. Hence it has been difficult to accurately operate a conventional sprinkler head.
Moreover, in the conventional sprinkler heads, the water discharge is controlled only by the bimetal or the shape-memory alloy as mentioned above. Therefore, in order to discharge water at a predetermined water discharging temperature, a shape-memory alloy needs to be produced and assembled such that it can be immediately restored when the surrounding temperature reaches the water discharging temperature. However, as mentioned above, since the temperature at which a shape-memory alloy restores can be defined only in a range within several ten degrees, and due to the production difficulty of a shape-memory alloy, which can immediately restore at a predetermined temperature and generation of a production error, adjustment of each sprinkler head in assembly has been required. This makes the sprinkler head inefficient, and deteriorates the mass-productivity.
The above-mentioned problems will be explained more specifically with reference to an automatically switchable sprinkler head using a shape-memory alloy disclosed in Japanese Unexamined Patent Publication No. 5-123419.
A sprinkler head of FIG. 9 has a coil spring-like shape-memory alloy 120 at a lower part of a main body 101. When the shape-memory alloy 120 exceeds a predetermined temperature by a fire, the shape-memory alloy 120 restores a preliminarily memorized stretched shape from the coil-spring shape. The restored shape-memory alloy 120 opens a pilot valve hole 110 by pushing up a pilot valve body 112 provided on a valve shaft 111, resisting to a spring 113. Accordingly, the pressure in a room above a piston 108 is lowered to raise the piston 108 so that a rubber packing 114 leaves a valve seat and fire extinguishing water is discharged from a water discharging opening 116.
When the temperature is lowered by the extinguishment of fire by the water discharge, the restoring force to the memorized shape of the shape-memory alloy 120 is lowered so that the pilot valve body 112 is pushed down by the spring 113 to close the pilot valve hole 110. Accordingly, the piston is pushed down by the pressure introduction of the fire extinguishing water from a pilot introduction hole 104 so that the valve seat is closed with the rubber packing 114 to automatically cease the water discharge.
However, in the automatically switchable sprinkler head using a shape-memory alloy as mentioned above, the operation cannot be conducted securely by opening the valve at a predetermined temperature in a fire.
FIG. 10 shows an elastic modulus of a shape-memory alloy with respect to the temperature. The restoring force is proportional to the elastic modulus. The shape-memory alloy is in the crystalline state of a martensite phase. With the temperature rise, it transfers to the crystalline state of an austenite phase. A shape-memory region, which is known as a two phase region, exists therebetween. The shape-memory region has a range in the temperature, for example, of more than several ten degrees.
In order to open a valve in a fire, using the shape-memory alloy 120 having such a characteristic, an operating temperature T1 is determined for starting the water discharge subject to hot air in the fire, and an elastic coefficient G1 corresponding to the operating temperature T1 at the point P is sought. Once the elastic coefficient G1 is sought, the restoring force of the shape-memory alloy 120 having a coil spring-like shape at the operating temperature T1 can be determined so that the force of the spring 113 is set such that the pilot valve body 112 is opened by the restoring force.
Then, the shape-memory alloy 120 is deformed to a stretched memorized shape while being heated at a predetermined operating temperature T1, and contracted to the initial shape before the memorizing operation in an ordinary temperature so as to be assembled as shown in FIG. 9.
However, since the elastic coefficient of the shape-memory alloy increases in the shape-memory region according to the temperature rise as shown in FIG. 10, the restoring force to the memorized shape gradually increases accordingly. On the other hand, the force for opening the pilot valve body 112 fluctuates by the fire extinguishing water pressure introduced into the piston room 109 and the sliding resistance of the valve shaft 111 in addition to the spring 113 force, and thus it has an irregularity to some extent.
Therefore, even if a predetermined restoring force is set by memorizing a stretched shape in the shape-memory alloy 120 at the predetermined operating temperature T1, the restoring force gradually increases according to the temperature rise. With a lowered force for opening the pilot valve 112, the water discharge can be started at a temperature lower than the predetermined operating temperature T1. Or with an increased force for opening the pilot valve 112, the water discharge can be started at a temperature higher than the predetermined operating temperature T1.
As a result, start of the water discharge when it reaches a predetermined operating temperature T1 by hot air in a fire cannot be ensured so that the operating temperature for starting the water discharge cannot be stable, and thus a problem is involved in the lack of reliability. Further, mass production is extremely difficult due to the need of labor in adjusting the shape-memory alloy.
Besides, if the fire extinguishing water is discharged from the water discharging opening 116 with the piston 108 raised in a fire, the water is scattered below the sprinkler head. Therefore, the fire extinguishing water is poured onto a lid 115 so as to cool down the shape-memory alloy 120 by the fire extinguishing water itself, resulting in the termination of the water discharge from the sprinkler head without extinguishing the fire.
Furthermore, if the lid 115 is damaged by the clash of the sprinkler head with a substance, the sprinkler head cannot be operated in a fire.
SUMMARY OF THE INVENTION
In order to solve the above-mentioned conventional problems, an object of the present invention is to provide an automatically switchable sprinkler head, capable of accurately opening a valve in a fire at a predetermined temperature using a shape-memory alloy so as to discharge fire extinguishing water with excellent reliability and mass productivity.
In order to achieve the object, the present invention has the following configuration. A subject of the present invention is a closed type sprinkler head for discharging fire extinguishing water in a fire, comprising a valve mechanism for switching the channel of the fire extinguishing water, connected to a fire extinguishing piping filled with the fire extinguishing water supplied with pressure.
A closed type sprinkler head in the present invention comprises a first heat sensitive operation part where a shape-memory alloy and a restoring force member are arranged facing to each other so that the shape-memory alloy is deformed to an initial shape by the restoring force member so as to maintain a valve mechanism at a water discharge stopping position when the temperature of the shape-memory alloy is lower than a predetermined memory restoring temperature, and the valve mechanism can be driven to a water discharging position by the restoring force of the shape-memory alloy to a memorized shape when the temperature of the shape-memory alloy reaches the memory restoring temperature, and a second heat sensitive operation part where a predetermined water discharge starting temperature higher than the memory restoring temperature is set so that the valve mechanism is maintained in a closed state regardless of the operation state of the first heat sensitive operation part when the temperature is lower than the water discharge starting temperature, and the closure of the valve mechanism is released so as to discharge fire extinguishing water by thermally disassembling itself at least partially when the temperature reaches the water discharge starting temperature.
It is more preferable that when the valve mechanism is in a state capable of being driven to the water discharging position, with the shape-memory alloy temperature lower than the memory restoring temperature, the valve mechanism is closed so as to cease the water discharge by the deforming the shape-memory alloy into the initial state by the restoring force member in the first heat sensitive operation part.
In such a sprinkler head according to the present invention, by receiving hot air by a fire, when it reaches the memory restoring temperature of the shape-memory alloy set at a low level, the shape-memory alloy generates the restoring force to deform into the memorized shape so that the first heat sensitive operation part is driven so as to have the valve mechanism in a state capable of discharging water. In this state, when the temperature is further raised by the hot air so that it reaches the predetermined water discharge starting temperature, the fusible alloy or the glass valve of the second heat sensitive operation part is thermally disassembled so that the sustenance of the operation of the first heat sensitive operation part already functioning in the water discharge available state is released so as to start the water discharge.
Therefore, even if the shape-memory alloy has a range in the memory restoring temperature, since the water discharge starting temperature can be ensured by being set at a predetermined temperature by the fusible metal or the glass valve provided in the second heat sensitive operation part as a heat sensitive member, the reliability of the automatically switchable sprinkler head using the shape-memory alloy can be ensured.
The temperature for starting the water discharge can be determined by the fusible alloy or the glass valve of the second heat sensitive operation part where the disassembling temperature can be easily set. On the other hand, the memory restoring temperature needs not be set accurately concerning the shape-memory alloy, having the memory restoring temperature hardly set accurately. Accordingly, since much time is not needed for the production or adjustment of a shape-memory alloy unlike the conventional products, the production efficiency of the sprinkler head can be improved so as to facilitate the mass productivity.
Moreover, since the water discharge is started only when both of the first heat sensitive operation part and the second heat sensitive operation part are driven in this configuration, even if, for example, the device is damaged by the clash with a substance during monitor, it is almost impossible that both of them are driven into the operation state due to the damage so that the inadvertent water discharge caused by the damage can be securely prevented.
With the temperature drop by the extinguishment of the fire by the water discharge, the valve mechanism in the first heat sensitive operation part can be in a closed state to automatically cease the water discharge owing to the shape-memory alloy deformation into the initial shape by the restoring force member, and thus damage by water after extinguishing the fire can be restrained at the minimum level.
Further, the temperature for stopping the water discharge is a shape restoring temperature set at a lower level with respect to the water discharge starting temperature set in the second heat sensitive operation mechanism, and by setting the water discharge stopping temperature at a sufficiently low level, the possibility of recurrence of the fire after the extinguishing operation can be drastically lowered.
It is further preferable that if the shape-memory alloy temperature regains the memory restoring temperature after stopping the water discharge by deforming the shape-memory alloy in the initial shape by the temperature drop by the water discharge in the first heat sensitive operation part, the water is discharged again by driving the valve mechanism to the water discharging position by the restoring force of the shape-memory alloy to the memorized shape. Therefore, if by any chance, the fire gains the momentum again after stopping the water discharge, the water discharge is automatically resumed so that the fire can be extinguished securely.
It is more preferable that the a plurality of shape-memory alloys are provided in the first heat sensitive part, surrounding the second heat sensitive operation part so that the valve mechanism can be driven to the water discharging position when at least one of the plurality of the shape-memory alloys restores the memorized shape. By accordingly providing shape-memory alloys in a plurality, the temperature difference by the direction of the hot air in a fire can be offset, and thus the water discharge operation can be conducted securely.
It is further preferable that the valve mechanism is driven into the closed state so as to stop the water discharge when all of the plurality of the shape-memory alloys restore the initial shape. Therefore, since the water discharge cannot be stopped as long as hot air flows from any direction, the fire can be extinguished securely.
It is more preferable that a water sprinkling part to be exposed below the sprinkler head when the second heat sensitive operation part is driven is provided so that the water discharge stoppage before completing the extinguishment of the fire can be prevented due to the cool-down of the shape-memory alloy by the fire extinguishing water itself by providing the shape-memory alloy above the exposed water sprinkling part, and further, the malfunction caused by the blockage of the hot air toward the shape-memory alloy with the fire extinguishing water can be prevented.
It is further preferable that the shape-memory alloy used in the first heat sensitive operation part has an initial shape of a coil spring contracted in the axial direction and a memorized shape of a coil spring stretched in the axial direction. The shape-memory alloy can have an initial shape of a plate spring shape with the center bent in an arc-like shape, and a memorized shape of a plate spring shape stretched in the axial direction.
It is more preferable that the valve mechanism comprises a main valve provided switchably in the channel from the inflow opening to the water discharging opening, an actuator for driving the main valve into the closed position by the pilot pressure supply and driving the main valve into the opened position by the pilot pressure discharge, and a pilot valve for supplying the pilot pressure to the actuator at the valve position determined by the initial shape of the shape-memory alloy so as to close the main valve and discharging the pilot pressure from the actuator at the valve position determined by the shape-memory alloy deformation to the memorized shape so as to open the main valve for the water discharge.
Herein, the actuator comprises a shaft member having a diaphragm piston or a piston slidably by the introduction or discharge of the pilot pressure integrally, with the diaphragm piston or the piston maintained at the closed state by the second heat sensitive operation part.
Another embodiment of the valve structure comprises a first valve member provided switchably in the channel from the inflow opening to the water discharging opening, maintained at the closed position by the second heat sensitive operation part, to be driven to the opened position by the release at the time of attaining the water discharge starting temperature for the water discharge, a second valve member provided in the secondary channel of the first valve member for switching the channel, an actuator for driving the second valve member to the closed state by the pilot pressure introduction from the inflow opening side and driving the second valve member to the opened state by the pilot pressure discharge, and a pilot valve for introducing the pilot pressure to the actuator at the valve position determined by the initial shape of the shape-memory alloy so as to drive the second valve member in the closed state and discharging the pilot pressure at the valve position determined by the shape-memory alloy deformation into the memorized state for discharging water, and driving the second valve member into the closed state for stopping the water discharge by the re-introduction of the pilot pressure when the shape-memory alloy restores the initial shape after driving the first valve member into the opened position.
It is more preferable that the second heat sensitive operation part comprises a fusible alloy or a glass valve to be disassembled by the heat attaining the water discharge starting temperature so as to be removed from the second heat sensitive operation part so that the water discharge starting temperature can be set accurately.
Moreover, a shape-memory alloy using, for example, an NiTi alloy has a high corrosion resistance as the material characteristic so that a high reliability can be ensured by the secure operation started by the hot air in a fire even after the installation over a long period. Furthermore, since there is no need for depending on the fire detection signal from a fire alarm concerning the stoppage and start of the water discharge, the problem of the water discharge caused by the malfunction of the fire alarm can be avoided so that the reliability can be ensured when it is mounted in fixed fire extinguishing equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view showing half each of the monitor state and the water discharge state of a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken on the line A--A of FIG. 1.
FIG. 3 is a graph showing the characteristic of the elastic coefficient actually measured with respect to the temperature of the shape-memory alloy of FIG. 1.
FIG. 4 is a graph for explaining the operation of the first embodiment of the present invention.
FIG. 5 is a cross-sectional view showing half each of the monitor state and the water discharge state of a second embodiment of the present invention.
FIG. 6 is a cross-sectional view taken on the line B--B of FIG. 5.
FIG. 7 is a cross-sectional view showing half each of the monitor state and the water discharge state of a third embodiment of the present invention.
FIG. 8 is a cross-sectional view taken on the line B--B of FIG. 7.
FIG. 9 is a cross-sectional view of a conventional sprinkler head.
FIG. 10 is a graph showing the characteristic of the elastic coefficient with respect to the temperature of the shape-memory alloy.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a vertical cross-sectional view of a first embodiment of an automatically switchable sprinkler head of the present invention. The right side with respect to the center line in the axial direction shows the cross-sectional structure of a constant monitor state where the water discharge is ceased, and the left side shows the cross-sectional structure of a state in the water discharging operation subject to hot air in a fire.
In FIG. 1, a sprinkler head 1 comprises a head connecting part 1a, a head main body part 1b, and a head water discharging part 1c from the above, screwed to each other in the axial direction. An actuator storing part 1d is assembled inside the central head main body part 1b.
The head connecting part 1a has a connecting screw 4 to be connected with a water supply piping for supplying pressed fire extinguishing water so that the pressed fire extinguishing water filled in the water supply piping from an inflow opening 3 can be introduced. A strainer 21 is mounted at the end of the inflow opening 3 for eliminating dusts.
A spool hole 3a is provided next to the position where the strainer 21 is assembled. The spool hole 3a communicates with an internal channel 3b. The spool hole 3a further leads to an internal channel 3c at the lower part through a communicating hole 20 in the periphery of the actuator storing part 1d with respect to the axial direction, and finally communicates with a water discharging opening 5 inside the head water discharging part 1c.
A spool valve body 7a is disposed in the spool hole 3a provided next to the inflow opening 3 in a constant monitor state for closing between the inflow opening 3 and the internal channel 3b. The spool valve body 7a is formed at one end of a valve shaft 7c. Next to the spool valve body 7a is a piston part 7b integrally formed in the actuator storing part 1d. An actuator 8 for switching the spool valve body 7a is assembled inside the actuator storing part 1d.
The actuator 8 is fixed by mounting the inner periphery part of a diaphragm 8a to the piston part 7b integrally formed in the valve shaft 7c, and sandwiching the outer periphery part of the diaphragm 8a with the actuator storing part 1d having a vertically-split structure. Accordingly, the storing room of the diaphragm 8a is partitioned into a lower side diaphragm room 9a and an upper side diaphragm room 9b.
As shown in the right side of the head main body part 1b, a pilot valve 12 is provided for the actuator 8. In the pilot valve 12, a pilot valve body 12a is accommodated in a pilot valve room 12b, with a valve shaft 12c elongating from the lower part of the pilot valve body 12a.
The pilot valve room 12b communicates with a pilot inflow channel 15 from the part where the strainer 21 is assembled in the inflow opening 3. The pilot valve room 12b further communicate with the diaphragm room 9a via a pilot supply path 16. Moreover, the lower part of the pilot valve body 12a communicates with a pilot discharge path 18 toward the opened part inside the head water discharging part 1c.
The pilot discharge path 18 is connected with the inside of the head water discharging part 1c for keeping a shape-memory alloy 10 provided outside the head water discharging part 1c away from the fire extinguishing water discharged from the pilot discharge path 18 by the pilot pressure discharge driven by the operation of the pilot valve 12, resulting in lowering the temperature heated by hot air.
A restoring spring (restoring force member) 14 and the shape-memory alloy 10 are provided below the pilot valve 12, forcing with each other via a cylindrical spacer 11 surrounding the outer periphery of the head water discharging part 1c. The shape-memory alloy 10 has a shape wound like a coil spring in this embodiment so as to be assembled in plural positions inside a protruding part 1e in the lower end outer periphery part of the head water discharging part 1c.
The lower end of the valve shaft 12c of the pilot valve 12 is fixed to a spacer 11 provided in the outer periphery part of the head water discharging part 1c next to the shape-memory alloy 10 slidably in the axial direction, with a restoring spring 14 assembled therebetween.
As the shape-memory alloy 10, for example, one using an NiTi alloy, and the like, having a one-way property with a high corrosion resistance can be used. The one-way property of a shape-memory alloy herein denotes the property where the shape-memory alloy is deformed into the initial shape at a low temperature after memorizing a constant shape at a predetermined memory restoring temperature so that it regains the memorized shape by being heated into a memory restoring temperature higher than the transformation point, but it cannot regain the initial shape deformed at a low temperature by being in the low temperature again thereafter.
The restoring shape with the coil spring stretched in the axial direction is memorized in such a one-way shape memory alloy 10 at a predetermined memory restoring temperature T1. Then the shape-memory alloy is contracted into the initial shape as illustrated in a low temperature so as to be assembled between the protruding part 1e and the spacer 11. The restoring force F1 of the shape-memory alloy 10 at the low temperature state in the initial shape is sufficiently lower than the restoring force F2 of the restoring spring 14 assembled in the pilot valve 12 side so that the shape-memory alloy 10 can maintain the initial shape as illustrated by receiving the pressure by the restoring force F2 of the restoring spring 14.
In a low temperature where the shape-memory alloy 10 has the initial shape, the pilot valve body 12a is maintained at a position for closing the pilot discharge path 18 as illustrated by the restoring force F2 of the restoring spring 14. Therefore, the pilot pressure from the pilot inflow path 15 stemming from the fire extinguishing water supplied in the inflow opening 3 is supplied to the diaphragm room 9a of the actuator 8 through the pilot valve 12 and the pilot supply path 16. The pilot pressure pushes up the piston part 7b with the diaphragm 8a so that the spool valve body 7a is fitted into the spool hole 3a for closing the channel from the inflow opening 3 to the internal channel 3b.
On the other hand, if the sprinkler head 1 receives hot air by a fire so that the shape-memory alloy 10 assembled in the periphery of the head water discharging part 1c is heated, the restoring force F1 is increased by the stretch of the shape-memory alloy 10 into the memorized shape. When the restoring force F1 exceeds the restoring force F2 of the restoring spring 14, the pilot valve body 12a is pushed upward by the valve shaft 12c via the spacer 11 so that the pilot discharge path 18 is closed with respect to the pilot valve room 12b and at the same time the pilot inflow path 15 is closed.
Accordingly, the pilot pressure supplied to the diaphragm room 9a of the actuator 8 flows away from the diaphragm room 9a through the pilot discharge path 18. Then, the spool valve body 7a is pushed downward by the pressure of the fire extinguishing water functioning on the spool valve body 7a so that the spool hole 3a can be in a state to be opened.
FIG. 2 is a cross-sectional view of the head main body part 1b of FIG. 1 taken on the line A--A. Communicating holes 20 separated in two positions are provided in the periphery of the actuator storing part 1d assembled inside, with the diaphragm room 9a of the actuator formed in the center. The diaphragm room 9a is connected with the pilot supply path 16 from the pilot valve room 12b of the pilot valve 12 assembled in the head main body part 12b side and further, a pilot inflow path 15 is provided upward.
As apparent from the left side cross-section of FIG. 1, the diaphragm room 9b above the diaphragm 8a is opened to the atmosphere by an atmosphere communication path 17 so that the piston part 7b can be moved vertically.
The first heat sensitive operation part 6 of the present invention is provided with a configuration including the spool valve body 7a, the actuator 8, the shape-memory alloy 10, the restoring spring 14 and the pilot valve 12 provided in the sprinkler head 1 shown in FIGS. 1 and 2.
A second heat sensitive operation part 22 is provided at the head water discharging part 1c side with respect to the first heat sensitive operation part 6. The second heat sensitive operation part 22 accommodates a deflector 23 descendably below the water discharging opening 5, maintained by a heat sensitive operation mechanism using a fusible alloy 30, which is a part of itself. That is, a supporting member 24 is mounted in the center part of the deflector 23, with the center concave part of the supporting member 24 contacting with the tip of the valve shaft 7c integrally comprising the spool valve body 7a and the piston part 7b.
The supporting member 24 is supported by the heat sensitive operation mechanism comprising the fusible alloy 30. The heat sensitive operation mechanism comprises a supporting plate 25, a pressing plate 26, a lock ball 27, heat gathering plates 28, 29. the fusible alloy 30, a spacer 31 and a fastening screw 32. That is, the two heat gathering plates 28, 29 having the fusible alloy 30 fixed thereon are fixed with the supporting plate 25 via the spacer 31 and the pressing plate 26 by the fastening screw 32, with the lock ball 27 fitted in the outer periphery part of the supporting plate 25 and the pressing plate 26, and fitted with a protruding part 1g inside the head water discharging part 1c and a fitting concave part 1f provided below.
If the fusible alloy 30 is melted by hot air in a fire in the second heat sensitive operation part 22, the lock ball 27 enters the gap with respect to the supporting plate 25 by the release of the pressing plate 26 supporting the same via the spacer 31. Then, the part below the supporting plate 25 is separated from the head water discharging part 1c as shown in the lower part of the left side crosssection so as to release the maintenance of the valve shaft 7c. When the second heat sensitive operation part 22 starts the operation, the deflector 23 (water discharging part) accommodated inside the head water discharging part 1c descends so as to be exposed below the sprinkler head 1.
When the maintenance of the valve shaft 7c is released by the separation of the fusible alloy 30 of the second heat sensitive operation part 22 by being melted by the heat in the fire, the spool valve body 7a of the first heat sensitive operation part 6 is already in a state to be opened at a shape memory temperature lower than that. Therefore, when the maintenance of the valve shaft 7c is released, the spool valve body 7a comes out from the spool hole 3a so as to open the channel. Then, the pressed fire extinguishing water from the inflow opening 3 is discharged from the water discharging opening 5 through the communicating hole 20 of the actuator storing part 1d, and further, the internal channel 3c so as to be reflected by the deflector 23 and scattered.
With the restoring temperature of the shape-memory alloy 10 for making the state where the spool valve body 7a can be opened by the actuator 8 by the operation of the pilot valve 12 provided in the first heat sensitive operation part 6 defined as T1, and the water discharge starting temperature determined by the melting temperature of the fusible alloy 30 in the second heat sensitive operation part 22 defined as T2, the memory restoring temperature T1 of the shape-memory alloy 10 is set lower than the water discharge starting temperature T2.
Therefore, by receiving hot air by a fire, the actuator 8 can be in a state capable of opening the spool valve body 7a by the operation of the pilot valve 12 when the temperature rises to the memory restoring temperature T1 of the shape-memory alloy 10. By melting the fusible alloy 30 when the temperature reaches the water discharge starting temperature T2 by the hot air by the fire, the maintenance of the spool valve body 7a is released via the valve shaft 7c by the second heat sensitive operation part 22 so as to start the water discharge.
The water discharge starting temperature T2 of the fusible alloy 30 for starting the water discharge is accurately determined by the fusible alloy 30 material. Since the memory restoring temperature T1 of the shape-memory alloy 10 is in the stage preceding the start of the water discharge, even if the restoring force of the shape-memory alloy 10 has a range with respect to the temperature rise, the water discharge can be conducted securely at a predetermined water discharge starting temperature T2 determined by the fusible alloy 30 material without suffering the effect of the restoring force range of the shape-memory alloy 10.
FIG. 3 shows the characteristic of the elastic coefficient G with respect to the temperature T of the shape-memory alloy 10 having a coil spring shape provided in the sprinkler head 1 of FIG. 1 actually measured. For example, with the water discharge starting temperature determined by the fusible alloy 30 in the second heat sensitive operation part 22 T2=74-C., the operation temperature range of the pilot valve 12 by the restoring force of the shape-memory alloy can be set in a range of T1=30 to 60-C., for example, at 50-C.
More specifically, the restoring force F2 of the restoring spring 14 is determined such that the channel of the pilot discharge path 18 of the pilot valve body 12a is closed in balance with the restoring force F1 of the shape-memory alloy 10 based on the elastic coefficient G50 at 50-C. in FIG. 3. That is, the restoring force F2 is set equally or slightly higher than the restoring force F1 of the shape-memory alloy 10.
Accordingly, when the temperature of the shape-memory alloy 10 reaches T1=50-C., the restoring force F1 of the shape-memory alloy 10 exceeds the restoring force F2 of the restoring spring 14 so as to push up the pilot valve body 12a and close the pilot inflow path 15 simultaneously to be in the state for discharging the pilot pressure from the diaphragm room 9a of the actuator 8.
When at least one of a plurality of the shape-memory alloys 10 provided in the outer periphery of the head water discharging part 1c reaches the shape restoring temperature T1, the spacer 11 is ascended so as to operate the pilot valve 12 to be in the water discharge available state. Accordingly, delay of the temperature detection by the air flow effect can be prevented. That is, if only one shape memory alloy 10 is provided, a long time is needed for the temperature rise of the shape-memory alloy 10 by the hot air when it is applied far from the shape-memory alloy 10. On the other hand, when a plurality of the shape-memory alloys 10 are provided as in the present invention, the fire temperature can be detected securely regardless of the hot air direction so as to start the water discharge.
Further, the protruding part 1e elongating at the outer periphery of the end part of the head water discharging part 1c also serves for repelling water for preventing the water discharge stoppage before extinguishing a fire by the discharged fire extinguishing water poured onto the shape-memory alloy 10 so as to directly cool down the same.
The plurality of the shape-memory alloys 10 provided around the second heat sensitive operation part 22 are provided above the exposing position of the deflector 23 as the water scattering part for scattering around the fire extinguishing water during the operation of the second heat sensitive operation part 22. Therefore, the water discharge stoppage before extinguishing the fire by blocking the hot air toward the shape-memory alloys 10 by the fire extinguishing water without cooling the shape-memory alloy by the discharged fire extinguishing water so that the malfunction can be prevented by accurately detecting the periphery heat.
More specifically, the shape-memory alloy 10 can be provided as long as it is positioned above the upper surface of the fire extinguishing water to be scattered by the deflector 23.
The operation of the embodiment shown in FIG. 1 will be explained with reference to FIG. 4. FIG. 4 is a graph showing the operation of each part of the sprinkler head in with respect to the surrounding temperature. Herein the curve a is a temperature curve immediately above the fire source, and the curve b is a temperature curve surrounding the sprinkler head 1 provided away from the position immediately above the fire source.
In a low temperature to be in a constant monitor state, the restoring force F2 of the restoring spring 14 is larger than the restoring force F1 of the shape-memory alloy 10 provided in the first heat sensitive operation part 6 in a constant temperature so that it is contracted in the initial shape via the space 11 as illustrated. Therefore, the pilot valve 12 opens the pilot inflow path 15 to the pilot valve room 12b by the pilot valve body 12a so as to be maintained at a valve position closing the pilot discharge path 18.
Accordingly, the pressure from the pressed fire extinguishing water filled in the fire extinguishing piping supplied from the inflow opening 3 is supplied to the diaphragm room 9a of the actuator 8 as the pilot pressure. The pilot pressure pushes up the diaphragm 8a and the piston part 7 as illustrated so that the spool valve body 7a at the tip of the valve shaft 3c is positioned at the spool hole 3a for closing the channel from the inflow opening 3 with respect to the internal channel 3b.
By receiving hot air by a fire in this state, the restoring force F1 of the shape-memory alloy 10 exceeds the restoring force F2 of the restoring spring 14 when the temperature reaches a predetermined memory restoring temperature T1 at which the shape was memorized. Then, the pilot valve body 12a is pushed up by the valve shaft 12c via the spacer 11 for closing the pilot inflow path 15 and at the same time opening the pilot discharge path 18 to the pilot valve room 12b.
Therefore, the pilot pressure supplied to the diaphragm room 9a of the actuator 8 is discharged from the pilot discharge path 18 from the pilot supply path 16 and the pilot valve room 12b so that the force for pushing the spool main body 7a to the position for closing the spool hole 3a is released. However, since the second heat sensitive operation part 22 is not operated so that the valve shaft 7c is maintained at a position where the spool valve body 7a is positioned at the spool hole 3a in a closed state.
Accordingly, when the temperature is raised by hot air by a fire with the first heat sensitive operation part 6 functioning to the water discharge starting temperature T2 where the fusible alloy 30 of the second heat sensitive operation part 22 is melted, the fusible alloy 30 is melted. When the fusible alloy 30 is melted, the supporting plate 26 descends with the spacer 31 and the heat gathering plates 28, 29 so that the lock by the lock ball 27 can be released. Then, the members of the heat sensitive operation mechanism below the supporting plate 25 are disassembled to fall off as shown in the left side cross-section in FIG. 1.
Accordingly, the maintenance of the valve shaft 7c in the closed state by the supporting member 24 can be released so that it falls down to the opening part 1h of the head water discharging part 1c with the deflector 23 so as to be maintained by the protruding part 1g. By the release of the maintenance of the valve shaft 7c, since the actuator 8 can drive the spool valve body 7a into the opened state already, the spool valve body 7a descends by the pressure of the fire extinguishing water from the inflow opening 3 so as to open the spool hole 3a.
Accordingly, the fire extinguishing water from the inflow opening 3 is discharged from the water discharging opening 5 toward the deflector 23 through the spool hole 3a, the internal channel 3b, the communicating hole 20 and the internal channel 3c so as to be scattered around by the contact with the deflector 23. Since the fire loses the force by the fire extinguishing water discharge, the hot air temperature gradually drops as shown by the curve b of FIG. 4.
When the fire is extinguished by the fire extinguishing water discharge, the temperature is lowered for not receiving the hot air. When the temperature of the shape-memory alloy 10 becomes lower than the memory restoring temperature T1 by the temperature decline, the restoring force F1 of the shape-memory alloy 10 becomes smaller than the restoring force F2 of the restoring spring 14 so that the shape-memory alloy 10 is deformed into the initial shape by being forced by the restoring spring 14 as illustrated.
At the time, the pilot valve body 12a of the pilot valve 12 closes the pilot discharge path 18 and at the same time opens the pilot inflow path 15 so that the pressure of the pressed fire extinguishing water with respect to the inflow opening 3 is supplied to the diaphragm room 9a of the actuator as the pilot pressure. Accordingly, the spool valve body 7a is pushed up by the diaphragm 8a and the piston part 7b so as to be fitted into the spool hole 3a for closing the channel. Then, the fire extinguishing water discharge can be stopped automatically.
If the fire regains the momentum by any chance as shown by the broken line in FIG. 4 after automatically stopping the fire extinguishing water discharge so that the temperature of the shape-memory alloy 10 is raised by the hot air to the memory restoring temperature T1, the pilot valve 12 functions again for discharging the pilot pressure in the diaphragm room 9a. Since the second heat sensitive operation part 22 is already functioning, the spool valve body 7a is taken out downward from the spool hole 3a for opening the channel by the fire extinguishing water pressure accompanying the pilot pressure discharge from the diaphragm room 9a so as to resume the fire extinguishing water discharge.
When the fire is extinguished after the resumption of the water discharge so that the temperature of the shape-memory alloy 10 becomes lower than the memory restoring temperature T1, the shape-memory alloy 10 is deformed into the initial shape by the restoring force 2 of the restoring spring 14. Then, the pilot valve 12 is switched into the state for supplying the pilot pressure to the diaphragm room 9a so that the spool valve body 7a returns to the spool hole 3a thereby for closing the channel again for stopping the water discharge.
FIG. 5 shows a second embodiment of an automatically switchable sprinkler head of the present invention. The right side with respect to the center line in the axial direction shows the cross-section of a state when the water discharge is ceased at a low temperature, and the left side shows the cross-section of a state in the water discharging operation subject to hot air in a fire. In the second embodiment, a glass valve is used for the second heat sensitive operation part 22.
In FIG. 5, an automatically switchable sprinkler head 1 comprises a head connecting part 1a, a head main body part 1b, and a head water discharging part 1c from the above, screwed to each other. An actuator storing part 1d is assembled inside the central head main body part 1b, with the spool hole 3a formed at the end part, and the spool valve body 7a formed at one end of the valve shaft 7c slidably assembled.
The actuator 8 is assembled in the actuator storing part 1d accommodated inside the head main body part 1b. In this embodiment, an actuator piston 7d is formed in the valve shaft 7c in place of the diaphragm piston as the actuator 8, slidably assembled in the cylinder 9.
The cylinder 9 is partitioned into the lower cylinder room 9c and the upper cylinder room 9d by the actuator piston 7d. The actuator 8 is operated by a plurality of the pilot valves 12. The pilot valve body 12a is assembled in the pilot valve room 12b, with the pilot valve room 12b communicating with the pilot inflow path 15 from the above, and the pilot supply path 16 communicating with the cylinder room 9c in the pilot valve 12.
Furthermore, the valve shaft 13 integrally elongating from the lower part of the pilot valve body 12a is provided, with the pilot discharge path 18 connected with the inside of the head water discharging part 1c for accommodating the valve shaft 13. The tip of the valve shaft 13 is fixed to the spacer 11, with the shape-memory alloy 10 assembled in the lower side of the spacer 11 and the restoring spring 14 assembled in the upper side of the spacer 11.
The first heat sensitive operation part 6 of this embodiment is provided with a configuration including the spool valve body 7a, the actuator 8, the shape-memory alloy 10, the restoring spring 14 and the pilot valve 12.
FIG. 6 is a cross-section of the head main body part 1b of FIG. 5 taken on the line B--B. As apparent from the cross-section, the actuator storing part 1d is assembled inside the head main body 1b, with the actuator storing part 1d provided with communicating holes 20 separated in two positions. The cylinder 9 is formed at the center part of the actuator storing part 1d, with the center penetrated by the valve shaft 7c comprising the spool valve body 7a and the actuator piston 7d.
The pilot supply path 16 communicates with the cylinder room of the cylinder 9 from the pilot valve rooms 12b provided in the number the same as that of the shape-memory alloys. The pilot inflow path 15 is formed upward from one of the pilot valve rooms 12b.
As shown in FIG. 5, the atmosphere communicating path 17 is connected to the cylinder room 9d above the actuator piston of the cylinder 9.
The second heat sensitive operation part 22 is provided for the head water discharging part 1c. In the second heat sensitive operation part 22 of this embodiment, the glass valve 36 is used in place of the fusible alloy 30 shown in FIG. 1 as a part of itself. The glass valve 36 is provided between the lower end of the valve shaft 7c and the supporting member 39 fixed by screwing to the supporting member 33 at the center of the deflector 37 mounted to the lower opening part of the head water discharging part 1c so as to maintain the spool valve body 7a at the tip of the valve shaft 7c located at the spool hole 3a in a closed state.
The position of the spool valve body 7a by the glass valve 36 can be slightly adjusted by screwing of the supporting member 38 with respect to the supporting member 39. As it is known, the glass valve 36 has a configuration where an alcohol solution is sealed in a capsule-like glass container so that the solution expands to break the glass capsule when it received hot air. As the temperature for breaking the glass valve 36, a predetermined operating temperature, that is, a predetermined water discharge starting temperature T2 in the sprinkler head 1 of the present invention is set. The memory restoring temperature T1 of the shape-memory alloy 10 provided in the first heat sensitive operation part 6 is set lower than the water discharge starting temperature T2 determined by the glass valve 36.
In the embodiment of FIG. 5, a plurality of the shape-memory alloys 10 are provided around the head water discharging part 1c, and a spacer 11, a restoring spring 14, and a pilot valve 12 are provided for each shape-memory alloy 10.
Since the shape-memory alloys 10, the restoring springs 14, and the pilot valves 12 are provided in plural positions around the sprinkler head 1, the shape-memory alloy 10 at a position receiving the hot air most starts the operation regardless of the hot air direction by a fire. The shape-memory alloy 10, which started the operation, discharges the pilot pressure from the cylinder room 9c by the pilot valve 12. When the temperature is raised by the hot air to the water discharge starting temperature T2 determined by the glass valve 36, the maintenance of the spool valve body 7a in the closed state is released by the breakage of the glass valve 36 so that the fire extinguishing water is discharged.
On the other hand, the water discharge is stopped by the temperature drop after extinguishing the fire by the water discharge when the temperature of all of the shape-memory alloys 10 provided in the plural positions around the sprinkler head 1 becomes lower than the memory restoring temperature T1. That is, when all of the shape-memory alloys 10 deform into the illustrated initial shape by the restoring spring 14 so as to restore the pilot valve 12, the pilot pressure supply from the actuator 8 to the cylinder room 9c becomes effective. At the time, the spool valve body 7a returns to the spool hole 3a by being pushed up by the actuator piston 7d so as to close the channel for stopping the water discharge.
FIG. 7 shows a third embodiment of an automatically switchable sprinkler head of the present invention. The right side with respect to the center line in the axial direction shows the cross-section of a state when the water discharge is ceased at a low temperature, and the left side shows the cross-section of a state in the water discharging operation subject to hot air in a fire.
In the third embodiment shown in FIG. 7, an automatically switchable sprinkler head 1 has a split configuration, comprising a head connecting part 1a, a head main body part 1b, and a head water discharging part 1c, screwed to each other. An inflow opening 3 is provided to the heat connecting part 1a, the strainer 21 is assembled in the inflow opening 3, and the spool hole 3a is formed for accommodating the spool valve body 7a.
The spool valve body 7a comprises the first valve mechanism 41 for maintaining the tip of the valve shaft 7 in a closed state with the second heat sensitive operation part 22 mounted below. The second valve mechanism 42 is provided around the first valve mechanism 41. The second valve mechanism 42 accommodates the valve piston 44 slidably in the cylinder 43 partitioned by the partition wall 50 of the head connecting part 1a and the head main body part 1b via the spring 45 provided above.
The valve piston 44 accommodates the inner periphery hole of the small diameter part 44a slidably in the cylindrical guide part 51 formed surrounding the spool hole 3a communicating with the inflow opening 3 and the large diameter part 44c with the level gradation in the axial direction slidably in the cylinder 43 via the cylindrical part 44b. Furthermore, the valve seal 46 is mounted on the end face of the large diameter part 44c for conducting the switching operation by the pressure on the end face of the partition wall 50 of the head main body part 1b.
FIG. 8 shows the cross-section taken on the line C--C in FIG. 7. The communicating holes 20 are formed in two positions partitioned by the partition wall 50 of the head main body part 1b, with the valve shaft 7c comprising the spool valve body 7a penetrating the center. The pilot inflow path 15 is formed for the pilot valve 12 in the periphery wall part.
As shown in FIG. 7, the pilot inflow path 48 is connected with the cylinder room accommodating the spring 45 of the valve piston 44 from the inflow opening 3. The pilot valve 12 is provided for the head main body part 1b. The pilot inflow path 15 communicates with the pilot valve room 12b of the pilot valve 12 from the cylinder room of the second valve mechanism 42. Furthermore, the opposite side of the pilot valve body 12a is connected with the inside of the head water discharging part 1c by the pilot discharge path 18.
The valve shaft 12c of the pilot valve 12 is taken out downward. The cylindrical spacer 11 is fixed to the tip of the valve shaft 12c, and the shape-memory alloy 40 is mounted between the lower part of the spacer 11 and the protruding part 1e elongating to the outer periphery end part of the head water discharging part 1c. In this embodiment, the shape-memory alloy 40 has a plate spring shape bent in the arc-like shape in the center. It memorizes the shape with the arc part stretched as shown in the left side cross-section when the temperature exceeds the memory restoring temperature by the hot air in the fire.
The first heat sensitive operation part 6 of this embodiment is provided with a configuration including the second valve mechanism 42, the shape-memory alloy 40, the restoring spring 14 and the pilot valve 12. The second valve mechanism 42 also serves as the actuator to be driven by the introduction or discharge of the pilot pressure.
As the second heat sensitive operation part 22 provided at the head water discharging part 1c, the fusible alloy 30 the same as the one used in the first embodiment shown in FIG. 1 is used as a part of itself. The memory restoring temperature T1 of the shape-memory alloy 40 is set lower than the water discharge starting temperature T2 in the second heat sensitive operation part 22 determined by the fusible alloy 30.
The operation of the third embodiment of FIG. 7 will be explained. In a constant monitor state at a low temperature, the shape-memory alloy 40 maintains the initial shape as the plate spring bent at the center in the arc shape by receiving the pressure from the restoring spring 14 as shown in the right side cross-section shown in FIG. 7. At the time, the pilot valve 12 shuts the communication with the pilot discharge path 18 by the pilot main body 12a.
Accordingly, the pressure of the pressed fire extinguishing water is applied to the cylinder room of the second valve mechanism 42 from the pilot inflow path 48 so as to push down the valve piston 44, combined with the force of the spring 45. The valve seal 46 mounted on the end face of the large diameter part 44c is pressed against the partition wall 50 of the head main body part 1b so as to be in the state with the valve closed.
If the shape-memory alloy 40 in the constant monitor state at a low temperature is heated to the predetermined memory restoring temperature T1 by the hot air in the fire, the shape-memory alloy 40 stretches in the axial direction so as to push up the pilot valve body 12a by the valve shaft 12c via the spacer 11, resisting to the restoring spring 14. Then, the pilot inflow path 15 is opened to the pilot discharge path 18 so as to discharge the pressure applied on the cylinder room of the second valve mechanism 42. Accordingly, the valve piston 44 is pressed and supported in the closed state only by the spring 45.
If the temperature is raised by the hot air to reach the water discharge starting temperature T2, the fusible alloy 30 provided in the second heat sensitive operation part 22 is melted so that the members provided below the supporting plate 22 are disassembled to fall off as shown at the lower side of the left side cross-section. Accordingly, the maintenance of the spool valve body 7a in the closed state by the first valve mechanism 41 via the valve shaft 7c is released so that the spool valve body 7c descends by the pressure of the fire extinguishing water from the inflow opening 3 so as to be accommodated in the spool storing part 47.
Therefore, the pressed fire extinguishing water flows inside the valve piston through the inflow opening 3 and the spool hole 3a so as to push up the valve piston 44, resisting to the spring 44 as shown in the left side cross-section so that the second valve mechanism 42 is released from the closed state by the valve seal 46. The introduced fire extinguishing water is discharged from the water discharging opening 5 provided in the lower part through the communicating hole 20 connected with the periphery part of the partition wall 50 as shown by the broken line so as to be contacted with the deflector 23 dropped downward by the heat sensitive operation of the second heat sensitive operation part 22 so as to be scattered.
When the fire is extinguished by the fire extinguishing water discharge from the sprinkler head 1 so as to lose the hot air and lower the temperature, the restoring force F1 of the shape-memory alloy 40 becomes lower than the restoring force F2 of the restoring spring 14 with the temperature lower than the predetermined memory restoring temperature T1. The shape-memory alloy 40 is pressed by the restoring spring 14 so as to be deformed into the initial shape shown in the left side cross-section. Then the pilot valve body 12a of the pilot valve 12 blocks the communication with the pilot discharge path 18.
Accordingly, the pressed fire extinguishing water is introduced to the cylinder room of the valve piston 44 form the pilot inflow path 48 so that the valve piston 44 descends as shown in the right side cross-section for contacting the valve seal 46 with the partition wall 50 and closing the inflow path leading to the communicating hole 20 so as to automatically stop the water discharge.
If the temperature of the shape-memory alloy 40 becomes higher than the memory restoring temperature T1 by the hot air by the recurrence of the fire after stopping the water discharge, the pilot valve body 12a of the pilot valve 12 is driven by the restoring force so as to make a state communicating with the pilot discharge path 18. Then, since the pressure applied on the cylinder room accommodating the spring 45 of the second valve mechanism 42 is discharged, the valve piston 44 ascends by the fire extinguishing water pressure applied on the inside of the valve piston 44 as shown in the left side cross-section so that the valve seal 46 is detached from the end face of the partition wall 50 for opening the channel again for the water discharge. When the temperature of the shape-memory alloy 40 becomes lower than the memory restoring temperature T1 by the water discharge, the water discharge is automatically stopped again.
The present invention is not limited to the above-mentioned embodiments but other optional configurations can be employed as long as the memory restoring temperature T1 of the shape-memory alloy for generating the restoring force for the heat sensitive operation of the first heat sensitive operation part is set lower than the water discharge starting temperature T2 of the fusible alloy or the glass valve for starting the water discharge at the second heat sensitive operation part, and thus the present invention is not limited by the above-mentioned embodiments.
Furthermore, the shape-memory alloy 10 and the restoring spring 14 do not always need to be provided, pressing with each other, but can be provided, facing with each other such that the restoring spring 14 can function for returning the shape-memory alloy into the initial state when it is lower than the memory restoring temperature T1. | The present invention is to discharge the fire extinguishing water by accurately opening the valve, using a shape-memory alloy at a predetermined temperature in a fire. When a shape-memory alloy in a first heat sensitive operation part is heated to a predetermined memory restoring temperature, a pilot valve is operated by the restoring force thereof so that a spool valve can be in a state capable of being opened by an actuator. When a second heat sensitive operation part reaches a predetermined water discharge starting temperature higher than the memory restoring temperature, a fusible alloy provided inside is thermally decomposed so that the first heat sensitive operation part maintained in the closed state is released so as to discharge the fire extinguishing water. When the temperature becomes lower than the memory restoring temperature by the fire extinguishment by the water discharge, a restoring spring deforms the shape-memory alloy into the initial shape so as to drive the valve mechanism into the closed state for stopping the water discharge. Accordingly, since the start of the water discharge can be controlled by the water discharge starting temperature having less fluctuation with respect to the memory restoring temperature, the water can be discharged further accurately. Moreover, since the memory restoring temperature needs not be set accurately, the production efficiency of the sprinkler head can be improved to facilitate the mass productivity. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to optical fiber cable, and in particular to constructions of such cables that are gas blocking.
In view of their potential for use in a submarine environment cable constructions have been proposed that are held out to be water blocking so that should such a cable be cut when submerged the penetration of water shall be limited. One example of a patent specification directed to water-blocked optical fiber cable is given by United Kingdom Patent Specification No. 2099179A. Although there are some similarities between the factors necessary to achieve satisfactory gas blocking, there are also major differences which are attributable in part to the much lower viscosity of gases, to the smaller values of hydrostatic pressure typically to be resisted, and to the fact that in achieving a gas-blocking design due attention must be paid to the prevention of ballooning of the cable sheath. It is in consideration of this last mentioned factor that the present invention is particularly concerned with cable constructions employing relatively high tensile modulus sheath materials.
SUMMARY OF THE INVENTION
Accordingly it is a general object of the present invention to provide a construction of optical fiber cable that is gas blocking. In pursuance of this there is provided a gas blocked optical fiber cable having an extruded sheath in which is embedded a central strength member that is longitudinally impermeable to gas. Also embedded in the extruded sheath, around the strength member, is a set of plastics packaged glass optical fibers spaced apart from each other and from the strength member. Each member of the set consists of a glass optical fiber possessing an optical waveguiding structure within the glass, and is provided with primary and secondary plastics coatings respectively of lower tensile modulus material that is not degraded at the extrusion temperature of the sheath material, and of higher modulus material that has a Vicat softening temperature higher than the extrusion temperature of the sheath material. The sheath is a pressure extruded sheath annealed to produce shrinkage, and is made of material having a tensile modulus of at least 700 MPa.
BRIEF DESCRIPTION OF THE DRAWINGS
There follows a description of the manufacture of a gas blocked optical fiber cable embodying the invention in a preferred form. This description refers to the accompanying drawings in which:
FIG. 1 depicts a schematic cross-section of the cable, and
FIGS. 2 and 3 depict respectively side view and transverse section of the extruder point employed in extruding the cable sheath.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The cable now to be described has been designed to meet a specification requiring a 3 meter length of the cable to be able to withstand a pressure of at least 850 KPa applied to one end for a period of at least 25 hours without producing any noticeable leakage. The test for revealing the presence of leakage consisted of immersing the other end of the cable in a beaker of water and looking for the formation of any bubbles.
A high tensile modulus material is required for the cable sheath, and this material must be capable of being annealed to produce the necessary contraction. Nylon 12 is a suitable material for this purpose having regard to the fact that it can be annealed to produce contractions in the region of 1/4% and that it can be extruded at a temperature of about 215° C. which is low enough not to degrade a conventional silicone resin fiber package primary coating and is beneath the Vicat softening temperature of ECTFE (ethylenechlorotetrafluoroethylene) which can satisfactorily be used as the secondary coating material.
Referring now to FIG. 1, the central strength member 1 for this cable was an epoxy saturated helically wound glass fiber bundle supplied by Sportex of Neu-Ulm Germany as a cable strength member. This strength member was 2.1 mm in diameter, and around it were arranged four plastics packaged optical fibers 2 that were 0.85 mm in diameter. These packaged fibers 2 were evenly distributed around the strength member 1, and were positioned to be buried approximately mid-way through the thickness of the cable sheath 3 which had an overall diameter of 6.8 mm.
At the core of each packaged fiber 2 was a silica optical fiber 125 microns in diameter possessing an internal waveguiding structure. These fibers were each provided with a thin silicone resin primary plastics coating in the conventional way on-line with the fibers being drawn from preform, one of the functions of such primary coatings being to protect the pristine surface of the freshly drawn fiber from degradation by atmospheric attack, and another being to provide a measure of mechanical buffering for the fiber affording some protection from microbending. The primary coated fibers had a diameter of 220 microns, and this was brought up to 0.85 mm by the provision of a higher modulus secondary coating of ECTFE extruded around the primary coated fiber.
Referring now to FIGS. 2 and 3, a special point was constructed for the cross-head extruder used for extruding the cable sheath. This point was designed to keep all four packaged fibers and the strength member separated from each other as they entered the extruder so that each of the fiber filaments should be individually completely encircled by the melt. For this purpose the extruder point comprised a central length 4 of 2.5 mm bore hypodermic tubing surrounded by four lengths 5 of 0.9 mm bore hypodermic tubing, with these five lengths being soldered with silver solder 6 in position within a tube 7. The bores of the lengths of tubing 4 and 5 were dimensioned to accept passage of the strength member 1 and the packaged fibers 2 respectively. The in-board end of the tube 6 was given a slight chamfer to assist the flow of the extruder melt around the emerging filaments.
Previous work on the pressure extrusion of Nylon 12 used for the provision of secondary plastics coatings on optical fibers has revealed that contractions in the region of 1/4% can be obtained with an appropriate annealing schedule for the product emerging from the extruder. (Some aspects of this work are reported by S. R. Barnes et al. in a paper entitled `Processing and Characterisation of Tight Nylon Secondary Coatings for Optical Fibres` given at the PRI `Plastics in Telecommunications III` Conference, Sept. 15th-17th, 1982, Conference Publication pages 15-1 to 15-12.) Based on this work, the cable sheath 3 was pressure extruded using a die with a bore the same diameter as the required finished size of the cable, a melt temperature of 213° C. and melt pressure of 2.9 MPa. The strength member and packaged fibers were preheated to 120° C., and, with a line speed of 4.5 meters per minute, the annealing schedule comprised passing the emerging cable first into a 0.6 meter long water trough maintained at 80° C., and then allowing it to cool in ambient air for a further 6.4 meters before take-up.
Tests upon the resulting cable revealed no noticeable leakage at a pressure of 1.3 Mpa. ln this particular construction adequate flexibility to meet the particular design specification results without recourse to any helical lay of the fibers around the strength members. Hence a straight lay configuration was adopted. It will however, be evident that the apparatus can be modified in a straight-forward manner to enable the production of gas-blocked cables whose packaged fibers are helically stranded around the central strength member. | A design of optical fiber cable that is gas blocking has a set of four plastics packaged optical fibers (2) around a central strength member (1). The fibers and strength members are embedded in spaced apart relationship in a nylon 12 pressure extruded sheath (3) which has been annealed to provide a contraction in the region of 1/4%. | 6 |
This application claims priority to German Application No. 199 28 777.5 filed on Jun. 23, 1999 and International Application Publication Number WO/01 00354 A1 filed on Jun. 21, 2000.
BACKGROUND OF THE INVENTION
The commercially most significant process for the production of amorphous and/or microcrystalline materials in the form of ribbons, wires, or foils is the rapid solidification of melted metal via melt-spinning processes. In this production process, a melted metal is sprayed through a nozzle onto a casting roller, casting rim, or casting drum which is rotating at speeds of up to 30 m/s. In so doing, the melt cools at a rate of cooling between 10 4 -10 6 K/s, solidifies on the casting surface to form a continuous ribbon, and is separated from the casting roller. In U.S. Pat. No. 4,142,571, an apparatus of this type for the production of metallic thin ribbons is described.
In the production process described for metal ribbons or foils the following problems or requirements for the casting wheel material arise:
a) The casting wheel material must have a sufficiently high thermal conductivity in order to discharge the heat being released during the solidification of the melt or during the further cooling of the solidified ribbon, wire, or foil. If this is not the case then, for example, the following problems can arise: sparking, no formation of ribbons, the strived-for microstructure of the metal foil to be produced, and thus its strived-for properties, not being achieved (for example, poor magnetic properties of amorphous foils due to partial crystallization), and/or the ribbon produced being brittle and thus mechanically not further processible.
b) The casting wheel material must be highly resistant to thermal as well as mechanical stress since the surface of the casting wheel is exposed to significant wear through its interaction with the melt or with the solidified ribbon. The occurrence of wear is expressed in a poor quality of the ribbon produced, such as, for example, holes, rough surfaces, and so on. These mechanical defects affect the mechanical and magnetic properties of the produced ribbon sensitively. The wear of the casting wheel furthermore leads to a poor thermal contact between casting wheel and ribbon or to a poor spreading of the melted metal on the casting wheel. Thus the rate of cooling of the ribbon is reduced which brings on the problems already cited under a). The constellation of problems of casting wheel wear just described occurs in particular with longer casting times and worsens with increasing casting time until finally proper ribbon formation is no longer possible.
SUMMARY OF THE INVENTION
It is thus one objective of the invention to find a material whose use as casting wheel material makes possible the problem-free production of amorphous or microcrystalline, qualitatively high-value metal alloys, in particular in large commercial amounts and which minimizes the problems described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 2 , and 3 illustrate metallurgic photographs of surface patterns of casting wheel materials.
DETAILED DESCRIPTION
For the reduction of wear of the casting wheels, which is determined to a considerable extent by the cyclic thermal stress during the casting process, they must have a sufficient mechanical hardness and strength as well as resistance to fatigue. In order to achieve the high rates of cooling which are necessary for the production of materials with amorphous microstructure, a uniformly high thermal conductivity of the casting wheels is furthermore required.
The high thermal conductivity and the high strength of the casting wheel materials cannot be developed independently of one another in this case. As a rule an increase of the hardness, which has a positive effect on the wear behavior of the casting wheels, leads to a reduction of the thermal conductivity. This brings with it problems for the casting of sensitive amorphous alloys.
The high thermal conductivity is achieved in this case by the use of highly thermally conductive steels, coppers, or copper alloys. In this case, quick-hardenable and dispersion-hardened copper alloys as well as Cu—Be bronzes come into use along with oxygen-free copper.
Along with the choice of material and an optimization of the material properties, the casting wheels can be provided with suitable coatings (see European Patent No. EP 0 024 506) in order to improve their wear behavior during the casting process.
A fine-grain composite of the casting wheel materials has proven itself in developing a high mechanical strength in connection with a high thermal conductivity (see FIG. 1 ), which has a favorable effect on the casting properties, in particular in relation to wear and lifetime of the casting wheel. Such composites can be realized by a reforming process (as a rule hot or cold forging or ring rolling) in connection with a heat treatment. Casting wheels for rapid solidification are thus as a rule first of all cut from cast blocks and reformed with various forging (free-form forging, drop forging) or other reforming process (for example, ring rolling). For forging and heat treatment processes of this type for casting wheel materials various process patents already exist: In JP 62-097 748 a composite with a grain size<1000 μm has been developed, for example, in a cast Cu—Cr—Zr casting wheel through a certain heat treatment which prevents the formation of large grains.
In WO 96/33828 composites as well as forging and annealing processes for casting rollers are described with which a uniform grain size <1000 μm can be developed in order to achieve sufficient hardness and resistance to wear in connection with high thermal conductivity.
In WO 98/07535 a grain size <500 μm in connection with a equiaxial grain geometry has been developed by forging variations in order to adapt the casting wheels to the profile of requirements (high strength, resistance to wear, high thermal conductivity). The wear and the lifetime of the casting wheels can be further improved by the grain geometry. Along with the contribution to the precipitation hardening, the strength according to the Hall-Petch equation is increased by this grain refinement (cf., for example, Gräfen, H.: VDI-Lexikon Werkstofrtechnik [Association of German Engineers' Encyclopedia of Materials Technology], VID Verlag, Düisseldorf 1993].
Despite these numerous efforts, casting wheels produced according to the state of the art do not solve the constellation of problems described above in the production of ribbons in a satisfactory manner.
In the case of these forged and heat-treated casting wheels, various problems still occur.
In practice, it has nonetheless proven itself difficult, as a rule, to produce the homogeneous and fine grain structure recognized as favorable. Thus an inhomogeneous composite structure, wherein very coarse grains are present along with small grains, can arise in the casting wheels through a non-uniform deformation during the forging process. This leads to an increased and inhomogeneous wear of the surface of the casting wheel when used. During the casting process, surface cracks are formed predominantly at these inhomogeneities or in part complete grains are torn out of the substrate material. The casting wheels must thus be reworked after a relatively short operating time for the purpose of eliminating the surface defects. The casting process must be interrupted for the reworking. On reworking (turning outside diameter) of the casting wheel, the problem can result in this case that the grain structure becomes inhomogeneous and/or coarser whereby the wear behavior deteriorates. This problem is linked to the production technology of conventional wheels which ultimately can guarantee a reproducible composite structure only at the surface.
Furthermore, areas on the surface of the casting wheel with different thermal conductivity can arise due to the partially inhomogeneous composite structure over the circumference of the forged casting wheels. This leads in the case of amorphous alloys, which have a very sensitive casting behavior (for example, Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 ) to undesired occurrences of brittleness due to locally delayed cooling of the melt. Thus, these amorphous thin ribbons are no longer suitable for further processing.
Along with the problems in the casting process, additional difficulties arise in the production of forged casting wheels of this type.
On heating up of larger parts for hot forging (casting wheels have diameters up to 1.2 m), stress fractures in the material can arise whereby the casting ring is completely destroyed. Moreover, long heat-up times have to be applied in the case of large structural parts in order to achieve a uniform heating throughout and therewith homogeneous deformation. In the case of certain modes of construction of the casting wheels, in which a ring of the highly thermally conductive alloy is shrunk onto a steel or aluminum hub, cracks or separation of material can arise during the shrinking process due to the inhomogeneous composite structure or other forging faults, whereby the casting wheel also cannot be used.
The production of the forged casting wheels according to the state of the art is very cost-intensive and demanding of apparatus due to the difficulties presented. Due to the production problems, only a few firms are in the position to produce casting wheels of this type with the requirement profile necessary for rapid solidification or to guarantee a consistently uniform quality of the casting wheels. Their acquisition is thus difficult and expensive.
It has been shown that the objective initially described can be realized in a particularly advantageous manner by the use of a casting roller material which has non-equiaxial, longitudinally extended crystal grains whose long axis is oriented in the radial direction of the casting wheel. This texturized grain zone prevents a breaking out of entire grains from the surface of the casting wheel since the grains are firmly anchored in the surface of the casting wheel by their longitudinal structure.
Furthermore, the longitudinal structure of the grains favors the discharge of heat from the surface of the casting wheel. A composite structure textured in this manner furthermore favors the formation of a uniform grain structure in the radial direction as well as in the circumferential direction. Thus no local nests of wear arise over the circumference which affect the ribbon quality locally. Furthermore, the uniformly fine composite structure also continues to exist after the reworking of the casting wheel (turning outside diameter).
Casting wheels with a composite structure of this type can be realized via a centrifugal casting process. In this production process the melt is solidified under the action of a very high radial acceleration (up to 120 times gravitational acceleration). By the pressure arising, a strong degassing of the melt occurs whereby all the impurities of the liquid melt are prevented. Through this solidification property a very pure, highly densified composite arises which already has very favorable mechanical properties in the cast state. The centrifugally cast components distinguish themselves moreover by a very homogeneous, finely structured cast composite which is free of intrusions, bubbles, and cavities. This cast composite, which is, above all at the surface, very homogeneous, reduces in addition the occurrence of wear and is thus an additional feature of our invention.
Through the uniform, directed solidification from the mold wall to the hole, the directed grain composite, favorable for the casting process, arises, in which composite the longitudinal grains are oriented in the radial direction. This very homogeneous composite structure causes a uniformly low wear over the entire circumference of the casting wheel and provides therewith a contribution to the reliability of the process of rapid solidification. By this composite structure the grains are furthermore firmly anchored in the surface of the casting wheel and the breaking out of complete grains, as can be observed in the case of forged casting wheels, no longer occurs in composites of this type.
Restricted by the very uniform composite structure no undesired variations in the thermal conductivity occur over the circumference of the casting wheel whereby sensitive, amorphous alloys can be cast with a higher process reliability and improved quality (ductility). The grain geometry and grain orientation in the radial direction moreover are associated with an accelerated heat discharge from the surface of the casting wheel, which brings with it significant advantages for the rapid solidification of melted metals.
Along with the advantages of the composite structure the cost-intensive reforming and forging processes are eliminated by the near-final-form forming with centrifugal casting, with which rotationally symmetric cast parts up to 6000 mm in diameter can be produced. This leads to a significant reduction of the production expense and therewith very favorable production costs.
Moreover, the production and availability difficulties described previously no longer exist. The invention is described in the following with the aid of an exemplary embodiment and with the aid of three figures.
The composite of a centrifugally cast casting wheel with the use of a Cu—Cr—Zr alloy is composed of a near-surface, fine-grain zone with a depth of up to ca. 15 mm with a grain size between 100 and 2000 μm and an adjacent stem crystal zone which has grains oriented in the radial direction with a grain size between ca. 1000 μm and 6000 μm.
The grains are penetrated, in the near-surface, fine-grain zone as well as in the adjacent stem crystal zone, with so-called dendrites, which is represented in FIG. 2 . This is characteristic for casting composites that are not further reformed. These dendrites lead to a mechanical reinforcement of the cast composite. Through this mechanical reinforcement of the casting composite the very good casting properties cited in the introduction to the description are decisively achieved for the casting wheels centrifugally cast according to the invention.
In FIG. 3, a section of a cast composite of a Cu—Cr—Zr casting wheel material is shown once again. Therein the grains oriented in the radial direction with longitudinally extended grain geometry are once again clearly recognizable.
It is noted that the photographs of ground surface patterns of Cu—Cr—Zr casting wheel materials shown in FIGS. 1, 2 , and 3 merely serve to illustrate a single casting wheel material. Images and metallurgic pictures of Cu—Ni—Si casting wheel materials as well as Cu—Be bronzes show similar casting composites which also have the typical dendrites. | The invention relates to novel casting wheels for the rapid solidification technique which are produced by centrifugal casting. The wheels are made of an alloy with a non-equiaxial granular structure, wherein the grains are elongated and their longitudinal axis lies substantially perpendicular to the casting-wheel surface. | 2 |
RELATED PATENT APPLICATIONS
This application claims priority from U.S. Provisional Patent Application Ser. No. 61/567,303, filed on Dec. 6, 2011, entitled ADJUSTABLE VENT ADAPTER FOR CLOTHES DRYER, the disclosure of which is incorporated herein in its entirety, including the specification, drawing, and claims, by this reference.
TECHNICAL FIELD
The present disclosure relates to clothes dryer vents, and more specifically, to a dryer vent adapter useful for installation of a clothes dryer, in order to compensate for misalignment between a clothes dryer exhaust outlet, and a discharge vent line for receiving hot moist air from a clothes dryer for transport through a wall or the like to an exterior exhaust discharge point.
BACKGROUND
Clothes dryers are used to remove moisture from clothing and/or other textiles, generally after such materials have been cleaned in a washing machine. Most clothes dryers which are designed for use in homes, apartments, or otherwise, have a hot air exhaust outlet for the discharge of hot air containing the moisture just removed from the clothing and/or other textiles being dried. In anticipation of installation of a clothes dryer, builders will generally install a receptacle to a discharge vent line as indicated in the plans, or as judged on site to be most practical. The receptacle and downstream discharge vent line are configured to receive the hot, moisture laden air for routing to and discharge at a suitable location discharge point, normally outdoors. However, clothes dryers come in various sizes, with varying heights and lateral locations of a hot air exhaust outlet. Thus, in most instances, during installation of a clothes dryer, the hot air exhaust outlet of the clothes dryer is not in alignment with the receptacle of the discharge vent line. Thus, there is a requirement for a dryer vent transition device or assembly for securely and safely routing hot moist exhaust air from the clothes dryer to a receptacle for a line configured for transport and exterior exhaust discharge of such hot moist air.
Various attempts have been made, with varying degrees of success, to provide an apparatus for use in various methods of compensating for misalignment between hot air exhaust outlets on clothes dryers and the receptacles for the discharge vent lines, so as to provide a suitable dryer vent transition device. One of the more useful configurations amongst various prior art vent adapters is described in my prior U.S. Pat. No. 6,578,286 B2, which issued Jun. 17, 2003, entitled Clothes Dryer Vent Adapter. In that apparatus, first and second cylindrical portions are provided which are adjustably positionable to a desired configuration for alignment of an inlet on the first cylindrical portion with a dryer hot air exhaust outlet, and for alignment of an outlet on the second cylindrical portion with the receptacle of a discharge vent line. However, offset distance available by use of that device is effectively limited by the diameter of the first and second cylindrical portions. As a practical matter, the offset-reach that may be overcome with that prior art design is limited, and in many embodiments of that design, such off-set reach distance may not exceed about eight (8) inches, or slightly less, when rather expensive adjoining cylindrical tubular segments of about twelve (12) inches in diameter are utilized. If smaller, less expensive adjoining cylindrical tubular segments of about eight (8) inches or less in diameter are utilized in that prior art design, then the misalignment, or offset-reach distance that may be overcome is limited to the maximum range of up to about three and a half (3.5) inches or thereabouts.
Thus, in spite of the extensive body of prior art for vent adapters for installation of clothes dryers, there still remains an as yet unmet need for an improved vent adapter that simply and effectively allows for use both when only a slight amount of misalignment needs to be corrected, as well as when relatively large misalignment distances need to be overcome. Availability of such an improved dryer vent adapter would reduce installation time, and be easy to utilize, especially if provided in a configuration that would accommodate an extension length that is as great as, or greater than, the typically encountered proposed center to center distance between a hot air exhaust outlet on a clothes dryer and a receptacle of a discharge vent line in a structure in which the dryer is to be installed. Moreover, it would be advantageous if such an apparatus were available in (or could easily be manufactured using) inexpensive materials, in an easy to use design, and manufacturable in various standard configurations and sizes.
OBJECTS, ADVANTAGES, AND NOVEL FEATURES
My novel adjustable dryer vent as disclosed herein includes a first duct having an inlet, a second duct having an outlet, and a joint therebetween rotating the second duct with respect to the first duct to a desired installation position, while preserving an effectively leak tight joint between the first duct and the second duct.
The adjustable dryer vent described herein is particularly advantageous in that it allows an installation contractor (or a homeowner's supply store) to maintain stock of a single part, rather than an assortment of parts, in order that the installer be prepared, during installation of a clothes dryer, to securely connect a clothes dryer exhaust outlet with a receptacle in a building structure for a discharge vent line, regardless of the offset distance that may be encountered, at least to a very large range of offset distances, and at any offset angle.
Further, it is an advantage that the adjustable dryer vent described herein may also be used when there is no offset distance, or offset angle, i.e., when the clothes dryer exhaust outlet and the receptacle in a building structure for a discharge vent line are perfectly in alignment.
It is also an object, in an embodiment of the adjustable dryer vent described herein that, to minimize or prevent leakage of warm moist air between first and second ducts, and such objective may be accomplished by design of the joint between the first and second ducts, and/or by providing a joint seal.
It is an object of the invention to provide an easily cleanable dryer vent adapter, and such objective may be accomplished, in an embodiment, by the use of a hinged end panel in the first duct and/or the second duct.
It is an advantage that in various embodiments, the first duct and the second duct may each be provided in the shape of hollow parallelepiped structures, and are adjustably arranged in a partially overlapping relationship, so that a joint between the first duct and the second duct may be securely provided in configuration with little or no leakage, so that warm moist and lint laden air does not escape into the area behind a clothes dryer.
In an embodiment, it is an advantage that the first duct and the second duct are easily adjusted with respect to each other, by the provision of a lubricated seal at the joint between the first duct and the second duct.
It is yet another objective to provide a dryer vent adapter that allows a clothes dryer to fit relatively tightly against a wall, without having to be concerned with restricted airflow as might result from crushed and/or contorted prior art flexible vent ducts.
In an embodiment, it is an advantage that the various components of the adjustable vent adapter may be provided using conventional sheet metal, and conventional sheet metal construction techniques, thereby minimizing cost.
Another objective is to provide a fire-safe dryer vent adapter.
Thus, it is yet a further advantage that the use of rigid materials of construction, such as the above mentioned conventional sheet metal, minimizes or avoids the buildup of lint, thus minimizing the danger of fire, as compared to prior art flexible plastic or metal structures that inherently include ridges, valleys, or crevices for accumulation of lint.
It is yet another objective to provide an adjustable vent adapter that reduces the installation labor time.
These and other objects, advantages, and novel features of the adjustable dryer vent adapter described herein will become apparent to the reader from the foregoing and from the appended claims, and the ensuing detailed description, as the discussion below proceeds in connection with examination of the accompanying figures of the drawing.
SUMMARY
I have now developed an improved dryer vent adapter. The device can be easily and quickly manually adjusted to overcome misalignment distance between a clothes dryer exhaust outlet and the receptacle for a discharge vent line that is configured for receiving hot moist air discharged from a clothes dryer. Further, in an embodiment, the device provides for accommodation of a small misalignment distance, and alternately for accommodation of a large misalignment distance. In an embodiment, misalignment distances in excess of about eight (8) inches may be accommodated during dryer installation. In an embodiment, misalignment offset distances of up to as much as about twenty (20) inches may be accommodated during dryer installation. In an embodiment, such an improved dryer vent adapter may be used even when there is no misalignment distance, thus saving labor and the costs of stocking of other devices to accommodate other offset-reach distance configurations.
In an embodiment, the dryer vent adapter includes a first duct having an inlet, and a second duct having an outlet, where the first duct and second duct are coupled and adjustably mounted with respect to each other. In an embodiment, the first duct and the second duct are rotatably mounted each with respect to the other, with a passageway therebetween adapted for passage of hot moist air through the passageway therebetween. In an embodiment, the first duct and the second duct are rotatably assembled in back-to-back fashion. In an embodiment, the passageway between the first duct and the second duct is coincident with an adjustable joint therebetween. In an embodiment, the first duct may be provided in the general configuration of a hollow parallelpiped sheet metal structure. In an embodiment, the second duct may be provided in the general configuration of a hollow parallelpiped sheet metal structure. In an embodiment, the first duct may have a generally rectangular cross-sectional configuration. In an embodiment, the second duct may have a generally rectangular cross-sectional configuration.
In an embodiment, the inlet to the first duct may be provided in a female configuration, adapted to receive a clothes dryer exhaust outlet. Tight fitting sizing may be utilized to minimize or eliminate leakage in the joint between the clothes dryer exhaust outlet and the inlet to the first duct. However, conventional duct tape suitable for the service conditions may be utilized to assure leak tight sealing of such first joint, in order to avoid outflow of moisture or lint from the clothes being dried. In an embodiment, the outlet from the second duct may be provided in a male configuration, adapted to connect with a building structure's receptacle for the dryer discharge vent line. Again, tight fitting sizing may minimize or eliminate leakage in such second joint between the outlet from the second duct and the receptacle for the discharge vent line. However, conventional duct tape suitable for the service conditions may also be utilized to assure sealing of such second joint. In any event, in various embodiments, and after fitting and alignment adjustment, an adjustable dryer vent as described herein may be quickly and easily manually secured for use.
The foregoing briefly describes certain aspects and elements of an exemplary adjustable vent adapter for clothes dryer installation, and various components thereof. The various objectives, features and advantages of the invention(s) will be more readily understood upon consideration of the detailed description, taken in conjunction with careful examination of the accompanying figures of the drawing.
BRIEF DESCRIPTION OF DRAWING
In order to enable the reader to attain a more complete appreciation of the invention, and of the novel features and advantages thereof, attention is directed to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 provides a rear perspective view of a typical clothes dryer, showing an adjustable vent adapter as described herein affixed to the clothes dryer exhaust outlet, and configured for operational placement and connection to a receptacle (not shown) for a discharge vent line to a through-wall passageway in a selected building structure.
FIG. 2 provides a top perspective view of an embodiment of an adjustable vent adapter for clothes dryer, configured for passage of hot moist air from an external inlet to an elongated first duct to an external outlet from an elongated second duct, and configured in a fully extended arrangement for correction of misalignment between a clothes dryer exhaust outlet (not shown) for hot moist air, and a receptacle for a discharge vent line in a building structure (not shown).
FIG. 2A provides another top perspective view of an embodiment of an adjustable vent adapter for clothes dryer, configured for passage of hot moist air from an external inlet to an elongated first duct to an external outlet from an elongated second duct, and configured in a fully extended arrangement for correction of misalignment between a clothes dryer exhaust outlet (not shown) for hot moist air, and a receptacle for a discharge vent line in a building structure (not shown), and further depicting the first turning radius R 1 afforded by the first duct, and the second radius R 2 afforded by the second duct, from as measured from centerlines of the inlet and the outlet.
FIG. 3 provides a diagrammatic view of an embodiment of the adjustable vent adapter for clothes dryer which was depicted in FIGS. 1 , 2 , and 2 A above, now showing that the adjustable vent adapter (a) may be adjusted to a desired position around an inlet centerline provided at the inlet to the first duct, with freedom of movement along a line A defined by radius R 1 , which thus locates the centerline of the joint passageway between the first duct and the second duct, that is more precisely, between the inlet centerline and a joint centerline, and (b) may be rotated with freedom of movement along a line B defined by radius R 2 , which extends between the joint centerline and the outlet centerline of the second duct.
FIG. 4 provides a diagrammatic view of an embodiment of the adjustable vent adapter for clothes dryer which was depicted in FIGS. 1 , 2 , 2 A, and 3 above, now showing that the adjustable vent adapter may be adjusted to a maximum extension position, wherein the second duct is rotated by an angle alpha (α) of one hundred eighty (180) degrees with respect to the first duct, so that, in combination, the first duct and second duct provide an overall maximum extension distance of R 3 , with freedom of movement along line C.
FIG. 5 provides a vertical cross-sectional view, showing an external inlet, an elongated first duct, a joint for passage of hot moist air from the elongated first duct to an elongated second duct, and an external outlet from the elongated second duct.
FIG. 6 shows an arrangement of the adjustable dryer vent, where there has been no angular displacement provided at the joint, and thus, the inlet and outlet are provided along a common baseline, and, in this embodiment, with their respective centerlines coincident.
FIG. 7 provides a partial cross-sectional view to illustrate a first embodiment for construction of a joint between the first duct and a second duct, using a plurality of notched and crimped flange leaf elements.
FIG. 8 provides a top perspective view of an embodiment of a second duct, before attachment to a first duct, showing a plurality of notched flange leaf elements that may be configured, after attachment, to provide a joint as set forth in FIG. 7 above.
FIG. 9 provides a bottom perspective of an embodiment for an elongated first duct, before attachment of an elongated second duct, showing a circular sidewall that defines a through passageway in a back portion of the elongated first duct, and which circular sidewall is configured for attachment to the elongated second duct, for example by use of notched and crimped flange leaf elements as shown in FIGS. 7 and 8 above.
FIG. 10 provides another embodiment for construction of a joint between an elongated first duct and an elongated second duct, using a plurality of notched and crimped flange leaf elements, and further including a joint seal member that may both facilitate movement between the elongated first duct and the elongated second duct, and effectively seal the joint against escape of moisture laden air, during operation of a clothes dryer.
FIG. 11 provides the layout for assembly for fabrication of an end piece for an elongated first duct and/or an elongated second duct, showing how a piece of sheet metal may be bent along the indicated broken lines, such as by a sheet metal brake (not shown) to fit into a generally rectangular shaped end opening of a partially completed, rectangular cross-section shaped tubular structure for an elongated first duct or an elongated second duct.
FIG. 12 is a side elevation view of an elongated first duct, showing how a hinged end panel may be used in the fabrication of an elongated duct, in order to provide a method and structure for cleaning of either an elongated first duct or an elongated second duct, rather than the simpler alternate method of construction using a fixed, insertable end piece, such as just illustrated in fabrication details noted in FIG. 11 above.
In the various figures of the drawing, like features may be illustrated with the same reference numerals, without further mention thereof. Further, the drawing figures are merely exemplary, and may contain various elements that might be present or omitted from actual implementations of various embodiments depending upon the circumstances. An attempt has been made to draw the figures in a way that illustrates at least those elements that are significant for an understanding of the various embodiments and aspects of the invention. However, the figures of the drawing are generalized in form in the interest of clarity and conciseness. Notably, other elements or functional components for an adjustable vent adapter for clothes dryer, as well as different embodiments or shapes of particular components such as the shape of certain elements such as the first ducts and second ducts as set forth herein, or an inlet to the first duct, or the outlet from the second duct, may be utilized in order to provide a useful, adjustable, and reliable vent adapter for clothes dryers, while within the literal scope and coverage of the claims set forth herein, or legal equivalents thereof.
DETAILED DESCRIPTION
Attention is directed to FIG. 1 , which illustrates a typical clothes dryer 20 having an outlet vent stub 22 in the lower reaches 23 of the reverse side 24 . An adjustable dryer vent adapter 30 is provided attached to the outlet vent stub 22 . The adjustable dryer vent adapter 30 includes an elongated first duct 32 and an elongated second duct 34 , which are arranged in an offset manner with respect to each other at a selected angle alpha (α), which in this embodiment is an obtuse angle, that is, more than ninety (90) degrees but less than one hundred eighty (180) degrees. As further explained below, in various embodiments, angle alpha (α) may be freely adjustable for dryer installation, that is, from no angular adjustment (where elongated first duct and elongated second duct are in overlapping alignment), to any adjustment, that is, having freedom of movement to any selected angle alpha (α) among a full three hundred and sixty (360) degrees. Thus, adjustment can be made in any direction around the dryer outlet vent stub 22 . The elongated second duct 34 is provided with an external outlet 36 , which, in an embodiment as illustrated in FIG. 1 , may be provided a generally cylindrical tubular configuration, with flutes 38 , to make installation and fitting easier, and in a male configuration for insertion into a receptacle (not shown) for a dryer discharge vent line in a selected building structure.
Turning now to FIG. 2 , a perspective view of an embodiment for an adjustable dryer vent adapter 30 is shown. The adjustable dryer vent adapter includes an elongated first duct 32 having an inlet side 40 and a first joint side 42 . Located on the inlet side 40 is an external inlet 44 . The first joint side 42 includes an internal exit 46 , herein defined by broken lines indicating the position of outlet sidewall 48 . The external inlet 44 and the internal exit 46 are spaced apart along a first longitudinal axis L 1 in a non-overlapping configuration. The elongated second duct 34 includes an outlet side 50 and a second joint side 52 . The outlet side 50 further includes an external outlet 36 . The second joint side 52 further includes an internal inlet 54 , defined by inlet sidewalls shown by broken lines 58 . The internal inlet 54 and the external outlet 36 are spaced apart along a second longitudinal axis L 2 in a non-overlapping configuration.
As may be better seen in FIG. 2A , an adjustable dryer vent adapter 30 may be provided in an embodiment where the external inlet 44 is provided in a cylindrical tubular configuration of radius R E measured from an external inlet centerline. In an embodiment, the external inlet 44 may be provided in female configuration, for accepting the outlet vent stub 22 of the clothes dryer 20 . Also, in an embodiment, the internal exit 46 may be provided with an outlet sidewall 48 in a generally circular configuration having a radius R IE measured from an internal exit joint centerline. In such instance, the elongated first duct 32 may be said to have a nominal length R 1 as measured from the external inlet centerline (indicated by reference numeral 56 ) to the internal exit joint centerline. In such an embodiment, R 1 may be provided sufficiently large and the radius R E and radius R IE may be each configured and spaced apart so that the external inlet 44 and the internal exit 46 do not overlap. In an embodiment, the nominal length R 1 may be provided at about seven and one half (7.5) inches, or less. Alternately, nominal length R 1 may be provided in a length exceeding about seven and one half (7.5) inches. Over time, for various locales, different standard lengths may be found to be useful, depending upon local construction practices, and the prevalent local dryer sizing and outlet vent stub 22 configurations.
As also seen in FIG. 2A , in an embodiment, the external outlet 36 may be provided in a cylindrical tubular configuration of radius R EO measured from an external outlet centerline. Further, in an embodiment, the internal inlet 54 may be provided in a generally circular configuration having a radius R II measured from an internal inlet or joint centerline. In an embodiment, the elongated second duct 34 has a nominal length R 2 as measured from the internal inlet 54 joint centerline to the external outlet 36 centerline (indicated by reference numeral 57 ). In such an embodiment, R 2 may be provided sufficiently large and the radius R EO and radius R 11 may be each configured and spaced apart so that the external outlet 34 and the internal inlet 54 do not overlap. In an embodiment, the nominal length R 2 may be provided at about seven and one half (7.5) inches, or less. Alternately, nominal length R 2 may be provided in a length exceeding about seven and one half (7.5) inches.
In various embodiments, an adjustable dryer vent adapter 30 may be provided using sheet metal for construction of each of the elongated first duct 32 and the elongated second duct 34 . In any event, a joint 60 is provided between the elongated first duct 32 and the elongated second duct 34 . In an embodiment, such joint 60 is configured between the first joint side 42 of the elongated first duct 32 and the second joint side 52 of the elongated second duct 34 . The adjustable dryer vent adapter 30 is rotatably adjustable at joint 60 , so that an angle alpha (α) between the first longitudinal axis L 1 and the second longitudinal axis L 2 may be set to a desired value for angle alpha (α).
In an embodiment, as seen in FIG. 8 , the second joint side 52 of the second duct 34 may include a plurality of flange tabs 62 . As further illustrated in FIGS. 7 and 10 , in an embodiment, the flange tabs 62 may be bent over the first joint side 42 of the elongated first duct 32 , to mechanically connect the first joint side 42 with the second joint side 52 and thus form joint 60 . However, embodiments may include use of flange tabs 62 on at least one of the first joint side 42 or the second joint side 52 , adjacent the internal exit 46 or the internal inlet 54 , respectively, in order to provided flange tabs 62 that mechanically connect the first joint side 42 and the second joint side 52 together. In various embodiments, the flange tabs 62 are turned and configured to extend a sufficient distance D J radially outward, as seen in FIGS. 7 and 10 , and thence against the surface of the component being placed in compression (e.g., the inner surface 64 of the first joint side 42 as seen in FIGS. 7 and 10 ), to provide friction between the plurality of flange tabs 62 and the adjacent surface, e.g. the inner surface 64 of the first joint side 42 of the elongated first duct 32 .
As illustrated in FIG. 10 , in an embodiment, a joint 60 ′ may be further provided with a seal 66 . In various embodiments, seal 66 may be provided in an elastomeric material. In other aspects, joint 60 ′ is similar to joint 60 as described otherwise herein. Alternately, in another embodiment as shown in FIG. 5 , a dry lube rolled edge, clamped seal 68 may be provided with an internal lube layer seal, or, but with similar appearance to the embodiment illustrated in FIG. 5 , an extruded polytetrafluoroethylene (Teflon®) retainer seal may be provided for clamped seal 68 . In such embodiments, a clamped seal 68 may be seated either or both outlet sidewall 48 of internal exit 46 , or the inlet sidewall 58 of internal inlet 54 . In such an embodiment, the clamped seal 68 cooperates with the joint assembly to provide a sealed joint 60 ″. In any event, in embodiments utilizing a seal, whether it be seal 66 as shown in FIG. 10 , or seal 68 as shown in FIG. 5 , or otherwise, the internal exit 46 has an outlet sidewall 48 , and the seal 66 or 68 is provided in a sealing relationship adjacent the outlet sidewall 48 .
As seen in the vertical cross-sectional view depicted in FIG. 5 , during operation hot moist air as indicated by reference arrows H 1 and H 2 from a dryer (not shown) enters the external inlet 44 and thence traverses along the elongated first duct 32 as indicated by reference arrow H 3 . Then, the hot moist air passes through joint 60 ″ (or similarly, joint 60 or 60 ′, in other embodiments) as indicated by reference arrows H 4 . The hot moist air then traverses along the elongated second duct 34 as indicated by reference arrow H 5 . Finally the hot moist air exits the external outlet 36 as indicated by reference arrows H 6 .
As may be seen in the various figures, for example FIG. 2A , the external inlet 44 may be provided as a short, substantially cylindrical tubular portion.
In an embodiment, the external inlet 44 may be provided with a radius R EI such that the external inlet 44 has a nominal overall diameter of approximately four (4) inches.
As may be seen in the various figures, for example FIG. 2A , the external outlet 36 may be provided as a short, substantially cylindrical tubular portion. In an embodiment, the external outlet 36 may be provided with a radius R EO such that the external outlet 36 has a nominal overall diameter of approximately four (4) inches. In an embodiment, the external outlet 36 may be fluted, e.g. having a plurality of flutes 38 .
In various embodiments, the primary components of the adjustable vent adapter 30 for clothes dryer may be conventional sheet metal. For example, in an embodiment, a suitable material may be 26 gauge galvanized sheet metal. Of course, thicker or thinner materials may be suitable. As illustrated in various drawing figures, in an embodiment, the elongated first duct 32 and the elongated second duct 34 may be provided in the general shape of hollow parallelepiped structures. As may be best seen in FIG. 5 , in an embodiment, the elongated first duct 32 may have opposing first 70 and second 72 end panels. The elongated second duct 34 may have opposing third 74 and fourth 76 end panels.
The opposing first 70 and second 72 end panels, as well as the opposing third 74 and fourth 76 end panels, may be fabricated from sheet metal cut as a hexagonal shaped blank 78 as depicted in FIG. 11 . Then, such aforementioned end panels may be bent along the broken lines 80 , 82 , 84 , and 86 depicted in FIG. 11 , normally at about a ninety (90) degree angle, for insertion into ends 90 and 92 of the elongated first duct 32 , and ends 94 and 96 of the elongated second duct 34 . The use of such first 70 and second 72 end panels, or of such opposing third 74 and fourth 76 end panels, enables such end panels to be fabricated from a friction fit sheet metal part. Alternately, or additionally, such end panels may be secured using conventional sheet metal assembly techniques.
Alternately, as depicted in FIG. 12 , either an elongated first duct 32 or an elongated second duct 34 may be provided with a first end panel and/or a second end panel which is configured as end panel 100 , which is hingedly affixed, via hinge 102 , to an elongated first duct 32 as depicted, or similarly, to an elongated second duct 34 . The hinged end panel 100 is closed, or opened, as indicated by the arc of lead line noted with reference letter Z. Opening may provide the owner or operator of the dyer the ability to clean accumulated dust and lint from the adjustable dryer vent adapter 30 , after a period of dryer operation. As also noted in FIG. 12 , in an embodiment, an elongated first duct 32 may be provided having a thickness T of about one and three quarters (1.75) of an inch, more or less. An elongated second duct 34 may be provided with similar thickness T. In an embodiment, the external inlet 44 may be provided with an inlet length I of about three and one half (3.5) inches, more or less.
The flexibility afforded by use of the adjustable dryer vent adapter 30 as described herein may be more fully appreciated by review of the adjustment possibilities as illustrated in FIGS. 3 and 4 . FIG. 3 provides a diagrammatic view, showing elongated first duct 32 having a first longitudinal axis L 1 and an elongated second duct 34 having a second longitudinal axis L 2 . The elongated second duct 34 is rotated at joint 60 to provide an angle alpha (α) between the first longitudinal axis L 1 and the second longitudinal axis L 2 , which is FIG. 3 is an obtuse angle. In FIG. 4 , the elongated second duct 34 is rotated at joint 60 to provide an angle alpha (α) between the first longitudinal axis L 1 and the second longitudinal axis L 2 of one hundred eighty (180) degrees, which provides maximum length of extension (i.e. maximum length of R 1 plus R 2 ) for the adjustable dryer vent adapter 30 . Note that the adjustable dryer vent adapter 30 may be adjusted to a desired position around an inlet centerline C L INLET provided at the external inlet 44 , with freedom of movement along a line A defined by radius R 1 , which thus locates the centerline C L JOINT of the joint 60 passageway between the elongated first duct 32 and the elongated second duct 34 , i.e., between the inlet centerline C L INLET and a joint centerline C L JOINT . The elongated second duct 34 may also be rotated with freedom of movement along a line B defined by radius R 2 , which extends between the joint centerline C L JOINT and the outlet centerline C L OUTLET of the elongated second duct 34 .
Note that FIG. 4 provides a diagrammatic view of an embodiment of the adjustable dryer vent adapter 30 where the vent adapter 30 has been adjusted to a maximum extension position, that is, wherein the elongated second duct 34 has been rotated by an angle alpha (α) of one hundred eighty (180) degrees with respect to the elongated first duct 32 , so that, in combination, the elongated first duct 32 and the elongated second duct 34 provide an overall maximum extension distance of R 3 , with freedom of movement along a line C. Moreover, note that for any given extension distance R 3 (i.e. the sum of R 1 and R 2 ) an adjustment distance, and location, may be accommodated from the external inlet centerline C L INLET to any point located within the area defined by the bounding line C, i.e. any point with a desired extension radius R X equal to or less than R 3 .
It is to be appreciated that the various aspects, features, structures, and embodiments of an adjustable vent adapter for clothes dryer as described herein is a significant improvement in the state of the art. The apparatus described is simple, reliable, and easy to use. Although only a few exemplary aspects and embodiments have been described in detail, various details are sufficiently set forth in the drawing figures and in the specification provided herein to enable one of ordinary skill in the art to make and use the invention(s), which need not be further described by additional writing.
Importantly, the aspects, features, structures, and embodiments described and claimed herein may be modified from those shown without materially departing from the novel teachings and advantages provided, and may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the various aspects and embodiments presented herein are to be considered in all respects as illustrative and not restrictive. As such, this disclosure is intended to cover the structures described herein and not only structural equivalents thereof, but also equivalent structures. Numerous modifications and variations are possible in light of the above teachings. The scope of the invention, as described herein is thus intended to include variations from the various aspects and embodiments provided which are nevertheless described by the broad meaning and range properly afforded to the language herein, as explained by and in light of the terms included herein, or the legal equivalents thereof. | An adjustable dryer vent transition device. The device provides an adjustable dryer vent adapter with an elongated first duct and an elongated second duct which are rotatably adjustable with respect each to the other. An external inlet is provided at the elongated first duct for receiving hot most air from a clothes dryer. An external exit is provided from the elongated second duct for discharge of hot moist air from a clothes dryer. The adjustable dryer vent adapter provides a three hundred sixty (360) degree freedom of movement for placement of the external inlet and the external outlet along centerlines that may be coincident, or spaced maximally apart according to the distances afforded by the length of elongated first duct and elongated second duct, and at any rotational angle with respect to an outlet stub from a clothes dryer. | 3 |
FIELD OF INVENTION
This invention relates to water closets and urinals.
BACKGROUND
The human body must rid itself of body fluids in the form of urine. This urine is accumulated in the bladder where it is stored, stretching its elastic like walls until the bladder sends a signal to the brain that it has attained “full” status. While the bladder has been receiving this urine it has been expanding and forcing the walls to stretch. This stretching in turn continues to create an increased pressure on the urine which is being held in check by the squeezing of the urinary tube which is surrounded by the stronger muscle of the prostate gland. When the brain receives the signal from the bladder that it is “full” it in turn sends a signal to the prostate gland to release or relax the pressure on the urinary tube allowing the urine; under pressure, to pass through the urinary tube located in the male penis. The wall of urinary tube in the penis expands as the pressurized urine enters it and flows toward the outlet or head of the penis where it is expelled by the bladder pressure. As the bladder pressure is reduced and the urine flow is diminished, the prostate again increases its pressure on the urinary tube as that bladder empties itself. The bladder is again ready to accept urine which will again be kept in check as the prostate muscle again squeezes the urinary tube and the process starts all over again. Due to the released amount of urine and the reduction in bladder pressure to expel the last of the urine, the walls of the urinary tube and the muscles of the penis puts the squeeze on any remaining urine and empties the urinary tube. The urine; having been expelled from the end of the urinary tube, which has now lost it's bladder pressure is pushed from the head of the penis and into space where it is immediately effected by atmospheric pressure and forcing it to create an arc from the end of the penis down to the urinal surface below. This stream of urine, upon leaving the end of the penis is in many instances fractured due to the unevenness of the penis opening and may create several fractures due to the solid stream along with many droplets breaking away from the perimeter of those fractured streams and are known as “splatter”. These streams and droplets under atmospheric pressure are being forced down into a resistance such as a flat bottom of the urinal bowl, a flat metal strainer, a somewhat flat rubber or plastic screen or an accumulated amount of water whose purpose is to create a soil pipe gas liquid seal in the urinal trap. Many of these conditions have been occurring for the last 150 years plus and has been the reason for the noisy sound of one urinating with splash and splatter of urine toilet seats, rims and floors. These basic same basic problems still occur today. In order to control the flow of these fractured and splatter streams of urine, one must make the receiving surface compatible rather then harsh. Therefore, a need remains for a urinal capable of overcoming these faulty, prior designs.
SUMMARY
Accordingly, an embodiment of the present invention is directed to an automated no splash urinal device, comprising: a vertically elongated receptacle bowl configured to inhibit a liquid from exiting the vertically elongated receptacle bowl as a stream of the liquid is directed into the vertically elongated receptacle bowl; a flushing mechanism, comprising: a flush valve configured for a four second operating flush, the four second operating flush producing 15 ounces of flush water; a water supply line configured to supply flush water to the flush valve; a flush hose for a left side of the vertically elongated receptacle bowl; a flush hose for a right side of the vertically elongated receptacle bowl; a flush tube for a rear wall of the vertically elongated receptacle bowl; a lighting mechanism, comprising: a motion detector for detecting a presence of a user of the automated no splash urinal device; two light emitting diodes (LED) configured to illuminate the vertically elongated receptacle bowl; a battery configured to supply power to the two LED; a water trap configured for receiving a content of the vertically elongated receptacle bowl, the water trap comprising: a three ounce water supply contained in the water trap, the water trap configured for prevention of gas flow from a sewage line; the water trap further configured a vertical distance from the stream of liquid, the vertical distance sufficient to eliminate direct contact between the stream of liquid and the three ounce water supply, wherein the automated no splash urinal device weighs less than ten pounds.
An additional embodiment of the present invention includes a removable top for servicing, the removable top is further configured with an offset hole in the removable top, the offset hole configured for a protruding flush valve activator, the removable top is further configured with a motion detector hole for the motion detector.
An additional embodiment of the present invention includes a flush valve configured for automatic shut-off, the automated no splash urinal device is fabricated of Polymeric material, and the automated no splash urinal device is further configured to couple to a wall via two integral hangers.
BRIEF DESCRIPTION OF THE DRAWINGS
The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:
FIG. 1 is a perspective view of the first embodiment of this invention;
FIG. 2 Is a perspective view of the embodiment of the urinal top section;
FIG. 3 is a perspective view of the embodiment of the urinal top lid;
FIG. 4 is a perspective view of one embodiment of the toilet connection; and
FIG. 5 is a perspective view of one embodiment of the toilet connection.
DETAILED DESCRIPTION
A lightweight, less than 10 Lbs. non ceramic urinal, which hangs on two wall brackets. It comes with a water supply line connected to a push type flush valve with auto shutoff, delivering 15 ounces of flushing water or 5 times the amount of drain pipe trap liquid of 3 ounces. This urinal develops no urinating sounds, splash or splatter from any of its parts. The urinal receiving bowl has an elongated drain pipe connecting to a soil pipe trap and drain line which connects to a fitting set into a drilled hole in the side of the toilet giving access to the toilets internal drain pipe system or the drain line can be connected directly into any soil pipe.
It is in the most simple, familiar design and uncomplicated construction containing significant and unique elements of improvements that make it capable of outperforming all previous urinals and financially accessible to the mass population throughout the world, even in our struggling economies. This invention addresses all of the known problems that have existed since the first urinal was made, some one hundred and fifty years ago. Listed here are the ten known problems and complaints that this invention addresses and ultimately corrects. #1. The waste of fresh water. #2. High cost of present urinals and flush valves. #3. Expensive installation. #4. Maintenance. #5. Urine contamination around urinals, allowing bacteria to develop and putting health at risk. #6. Splattering and splashing or urine on those urinating. #7. Odors that permeates the surrounding air. #8. Cost on average, the use of many light bulbs used to illuminate a bathroom and many are to often left on. #9. The sound of someone urinating followed by the loud flushing of many gallons of-fresh water for only a few ounces of urine.
The Home Urinal accomplishes to an acceptable degree that has never been reached before due to its special designs. FIG. 1 shows a perspective view of one embodiment of the present invention. Using a receding and deep and descending surface of the urinal bowl 12 from under and inside the top lip 13 of the urinal bowl down towards the deep oversized elliptical cone, the inside vertical sides of which lead into the drain line 19 .
FIG. 1 displays additional components of the home urinal including 2 is a perspective view of the urinal lid 2 , the hole 3 in the front of the lid for “eve” of motion detector, the hole 4 in the top of the lid for flush valve activation, the space 5 for the flush valve body, the space 6 for the motion detector, the fresh water tube 7 from toilet service valve to flush valve, the internal flush hose 8 for the right side, the flush hose 9 for the left side, the two wall hanger brackets 10 , the inside upper wall rear wall flushing tube 11 , the redesigned urinal bowl 12 , the urinal bowl top flush water control flange 13 , the urinal bowl outside top flush water control flange 14 , the outside lower section 15 of the urinal bowl, the elongated drain pipe section 16 of the urinal bowl the drain pipe trap 17 , the drain pipe trap clean out plug 18 , and the drain pipe 19 .
FIG. 2 shows a perspective view of one embodiment of the urinal top section. Elements of the top section may include: an interior rear wall 20 of the urinal, the left side wall 21 , the shelf 22 , for the flush valve and motion detector, the left side flush tube 23 , the service water tube 24 to inlet side of flush valve, the “press to activate” flush valve 25 , the flush valve outlet “T” connection 26 , the right side flushing tube 27 , the inside right wall 28 of the urinal, the outside right wall 29 of the urinal, the “T” connection 30 for both side wall flush tubes, and the interior rear wall top flushing tube 31 .
FIG. 3 shows a perspective view of one embodiment of the urinal top lid. Elements of the top lid of the urinal may include: the top lid 32 the hole 33 in the front of the lid, for “eve” of motion detector, the hole 34 in the top of the lid, for flush valve activator, the large decal 35 indicating “Faucet Shuts-Off Automatically,” the motion detector and battery case 36 , and the two LED lifetime light bulbs 37 .
FIG. 4 shows a perspective view of one embodiment of the toilet connection. Elements of the toilet connection may include: the internal toilet drain pipe 38 , the drain pipe adapter fitting 39 , the toilet base 40 , and the soil pipe 41 . In this embodiment, a hole is wet drilled in the toilet base wall on either side or the rear just above the base plate and a fluid type coupling means 39 is installed for joining the urinal drain lines 19 to the toilet internal sewage pipe 38 .
FIG. 5 shows a perspective view of one embodiment of the toilet connection. Elements of the toilet connection may include: the internal toilet drain pipe 42 , the threaded drain pipe adapter fitting 43 , the factory installed threaded plug 44 for shipping, the thicker threaded section 44 of the toilet wall, the toilet base 46 , and the soil pipe 47 . In this embodiment, the drain line 19 is connected directly into the toilet threaded drain pipe adapter fitting 43 via thicker threaded section 44 . Additionally, drain pipe 19 may be directly connected into a septic tank or other type of drain field application.
This invention deals with those previous indicated problems by making these following improvements. Some of which are, #1 The least amount of fresh water required per flush in the industry of 15 ounces whose flush valve is quiet and takes only 4 seconds to operate. #2 A no splash, no splatter quiet urinal. #3Newly designed angular surface of the receptacle bowl combining to develop an elongated drain pipe 16 . Although this urinal drain pipe 16 is elongated, it does not negate the person from seeing the liquid in the trap 17 at its base which is required by some plumbing codes. Within the same elongated drain pipe 16 the urine stream angle which is much lower than the visual angle, will not allow the urine stream to directly impinge on the liquid in the trap 17 therefor no splash or splatter can transpire. #4 The relocation of the drain pipe trap 17 along with joining the drain line with the toilet internal sewage pipe 34 and 42 . Along with these improvements the Home Urinal comes with all the hardware required to install it within most bathrooms. This includes the fresh water line 7 and compression fittings, the “T” fittings and internal flush lines 23 and 27 secured by the “U” bolt and mounted flush valve, battery operated Motion Detector 36 and two LED light bulbs and batteries, 37 , two wall fasteners, 10 drain pipes 19 Ells and couplings along with chemicals and instructions.
There is a lightweight cover or lid on the urinal 32 much like any toilet tank lid. The flush valve 25 protrudes up through the center of the lid 34 for easy access along with a decal 35 on the front of the lid indicating “FAUCET SHUTS OFF AUTOMATICALLY”. There is also a hole in the front center 33 where the Motion Detector sensor “eye” 36 fits flush with the front lip of the lid. The sensor will activate when someone enters a darkened bathroom or at night. The sensor illumination is from two small LED lifetime light bulbs 37 battery powered and bright enough to do almost anything in the bathroom, it will remain on for two minutes after one leaves the bathroom giving a soft glow back to their room. This is a safety factor for the young, old and everyone in between because when one leaves a illuminated room into a dark hallway or bedroom, one must wait until our vision adjust to the darkness. The urinal top 32 is very lightweight and also removable to make any service adjustments which may become necessary, such as battery changes every two years. The entire urinal weighs less than ten pounds and hangs on the wall using two supplied wall hangers 10 . The Home Urinal is easy to install and operate, easy to clean with brush supplied and service if necessary. It also eliminates that female question “WHO LEFT THE SEAT UP” once and for all as males will no longer be required to lift the seat on a toilet to urinate. It is “Whisper Quiet” in operation both for urinating and for flushing. The total cost of the total cost of the complete kit will be less than one third of those on the market today. It should have a return on investment of only 2 years, saving you money and a 1,000 gallons of fresh water per month per mate person for many years to come. Installation can be done by a Do-It-Yourself person or by a plumber in less than 4 hours. The walls and floor need not be disturbed and the inch and a quarter drain pipe meets plumbing code with no electric required. | A lightweight urinal designed for low water use and intended to be used adjacent to a toilet in a household residence. Device connects to existing water source and waste lines with minimal effort by a homeowner or professional installer. Push button control in combination with the shape of the urinal flushes contents automatically after use while using just 15 ounces of water. | 4 |
RELATED APPLICATION DATA
[0001] This application claims the benefit of U.S. Provisional Application No. 61/678,346, filed Aug. 1, 2012. The disclosure of U.S. Provisional Application No. 61/678,346 is incorporated herein by reference in its entirety.
GOVERNMENT RIGHTS
[0002] This invention was made with the support of Grants RO1 AI054483-09, U54 AI057160-08, R01 AI084887-02 from the National Institutes of Health. The government of the United States of America may have certain rights in this work.
INCORPORATION BY REFERENCE OF SEQUENCE LISTING
[0003] The Sequence Listing, which is a part of the present disclosure, includes a computer readable form comprising nucleotide and amino acid sequences of the present invention submitted via EFS-Web. The subject matter of the Sequence Listing is incorporated herein by reference in its entirety.
INTRODUCTION
[0004] Astroviruses are non-enveloped, positive-sense, poly-adenylated RNA viruses often associated with gastrointestinal disease (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007). To date, astroviruses have been isolated from a number of hosts, including wild and domestic animals, marine mammals, birds, and humans, and new astrovirus-susceptible hosts continue to be identified (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Finkbeiner, S. R., et al., Virol. J. 5: 117, 2008; Koci, M. D., et al., J. Virol. 74: 6173-7, 2000; Li. L, et al., J. Virol. 85: 9909-17, 2011; Phan, T. G., et al., PLoS. Pathog. 7: e1002218, 2011; Reuter, G., et al., Arch. Virol. 156: 125-8, 2011). The Human astroviruses (HAstV) in particular are an important cause of gastroenteritis in inpatient and outpatient pediatric, HIV-infected and immunocompromised, and elderly populations, and have been shown to cause sporadic outbreaks of gastroenteritis in immunocompetent adults as well (Belliot, G., et al., J. Med. Virol. 51:101-6, 1997; Coppo, P., et al., Ann. Hematol. 79:43-5, 2000; Cunliffe, N. A., et al., J. Med. Virol. 67: 563-6, 2002; Dennehy, P. H., et al., J. Infect. Dis. 184: 10-5, 2001; Finkbeiner, S. R., et al., J. Virol. 83: 10836-9, 2009; Gray, J. J., et al., J. Med. Virol. 23: 377-81, 1987; Grohmann, G. S., et al., N. Engl. J. Med. 329: 14-20, 1993; Herrmann, J. E., et al., N. Engl. J. Med. 324: 1757-60, 1991; Jeong, H. S., et al., Korean. J. Peds. 55: 77-82, 2012; Lewis, D. C., et al., J. Hosp. Infect. 14: 9-14, 1989; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007; Oishi, I., et al., J. Infect. Dis. 170: 439-43; Palombo, E. A. and Bishop, R. F., J. Clin. Microbiol. 34: 1750-3, 1996; Shastri, S., et al., J. Clin. Microbiol. 36: 2571-4, 1998; Wood, D. J., et al., J. Med. Virol. 24:435-44, 1988). As a viral agent of pediatric diarrhea, astrovirus is reportedly second only to rotavirus (Dennehy, P. H., et al., J. Infect. Dis. 184: 10-5, 2001; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007), with a seroprevalence of neutralizing antibodies to Human Astrovirus (HAstV) 1 nearing 90% by the age of 9 (Koopmans, M. P., et al., Clin. Diagn. Lab. Immun. 5: 33-7, 1998). Furthermore, given the incorporation of rotavirus vaccines into national immunization programs (Patel, M. M., et al., Lancet. Infect. Dis. 12: 561-70, 2012), the proportion of astrovirus-mediated diarrhea is likely to increase.
[0005] However, astrovirus disease is not limited only to the gastrointestinal tract. Astroviruses have been implicated as the cause of hepatitis in ducks and neurological disease in minks (Blomström, A. L., et al., J. Clin. Microbiol. 48: 4392-6, 2010; Gough, R. E., et al., Avian. Pathol. 14: 227-36, 1985). In humans, an astrovirus was identified as the cause of encephalitis in an immunocompromised child with X-linked agammaglobulinemia (Quan, P. L., et al., Emerg. Infect. Dis. 16: 918-25, 2010). Furthermore, we have previously reported the presence of the human astrovirus MLB2 in the plasma of a febrile child (Holtz, L. R., et al. Emerg. Infect. Dis. 17: 2050-2, 2011).
[0006] The Astroviridae family is divided into the mamastrovirus and avastrovirus genera-characterized by the ability to infect mammals and avian species, respectively. Across both genera, the astrovirus genome ranges from 6.1 to 7.7 kilobases (kB) in length, not including the 3′-polyadenylated tail, and contains three open reading frames (ORFs) and 5′ and 3′ untranslated regions (UTRs) (Mendez, E. and Arias, C. F., Fields Virology, 5 h ed. p. 981-99, 2007). ORF1a encodes a polypeptide of 920-935 amino acids (aa) in length containing conserved motifs, including a serine protease (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007). A highly conserved heptanucleotide motif and downstream hairpin structure at the ORF1a/ORF1b junction generates a-1 frameshift (Jiang, B., et al., P. Natl. Acad. Sci. USA. 90: 10539-43, 1993; Lewis, T. L. and Matsui, S. M., Arch. Virol. 140: 1127-35, 1995) to lead to the translation of an ORF1a/1b polypeptide which is later cleaved into polypeptides corresponding to ORF1a and ORF1b (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007). ORF1b encodes a polypeptide of approximately 515-528 as which contains the RNA-dependent RNA polymerase (Lewis, T. L., et al., J. Virol. 68: 77-83, 1994; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007). ORF2 encodes a 672-816 aa polypeptide which encodes the viral structural proteins including the capsid (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Lewis, T. L., et al., J. Virol. 68: 77-83, 1994; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007).
[0007] Despite the prevalence of astrovirus infection and the potential for extra-intestinal disease, there are no specific treatment protocols for astrovirus infection, and no vaccine exists. To date, little is known about the molecular mechanisms of astrovirus infection, replication, and disease pathogenesis, in part due to the lack of a genetically manipulable small animal model. Astroviruses have been identified as pathogens in humans as well as in a wide variety of non-human animals. Thus, it would be desirable to develop new approaches for treating or preventing diseases caused by astroviruses. This can be achieved by the development and testing of new vaccines and pharmaceutical agents using small animal models of astroviral diseases.
SUMMARY
[0008] The present inventors have utilized next generation sequencing (NGS) in combination with sequence analysis software (the pipeline VirusHunter software package) to identify a number of novel human astroviruses by analyzing the nucleic acid sequences generated by the Roche/454 next-generation sequencing platform (Voelkerding, K. V. et al., Clinical Chemistry 55: 641-658, 2009) or by Sanger sequencing (Sanger, F., et al., Proc. Nat'l. Acad. Sci. USA 74: 5463-5467, 1978) and their predicted translation products (Finkbeiner, S. R., et al., J. Virol. 83: 10836-9, 2009; Finkbeiner, S. R., et al., Virol. J. 5: 117, 2008; Finkbeiner, S. R., et al., J. Virol. 6:161, 2009). Whereas previous work in our lab identified murine norovirus as a common pathogen found in research mice, we applied our custom pipeline to further analyze the enteric virome of the research mouse (Karst, S. M., et al., Science. 299:1575-8, 2003; Thackray, L. B., et al., J. Virol. 81:10460-73, 2007; Wobus, C. E., et al., J. Virol. 80: 5104-12, 2006).
[0009] The present inventors have established that astrovirus can infect rodents such as, without limitation, laboratory mice. Accordingly, the present disclosure relates to methods of detecting astrovirus in mammals, in particular murine astrovirus in mice.
[0010] In various aspects, the present teachings can comprise methods of monitoring astrovirus infection in a population of mice, such as, in non-limiting example, in a colony of laboratory mice. The methods can comprise detecting a murine astrovirus antigen or nucleic acid in one or more animals housed in a colony.
[0011] In various embodiments of the present teachings, murine astroviruses can provide an animal model for developing and testing vaccines vaccination protocols, pharmaceutical agents, and therapeutic treatment protocols to prevent and/or treat diseases caused by astroviruses or linked to astrovirus infection. In various embodiments, the animal model can be a murine model. Because related astroviruses infect humans, a murine astrovirus model of infection can serve as a model system for developing vaccines and therapeutics that could be effective in preventing or treating human astrovirus-linked diseases, or astrovirus-linked diseases in non-human animals.
[0012] Thus, one embodiment can involve the use of mice that are infected with astroviruses. Any of a variety of strains of mice can be used. The present studies have shown that adaptive immunity is essential for restricting astrovirus replication as has also been shown to be the case in humans (Wood, D. J., et al., J. Med. Virol. 24:435-44, 1988). Thus, in certain embodiments, the murine model can include mice that are immunocompromised such as B-cell deficient mice (MuMT) or RAG deficient mice (RAG1 −/− ).
[0013] In some aspects, the present teachings include selecting, monitoring, or modifying a treatment on the basis of the detection of the presence, absence or quantity of astrovirus in a subject. In these aspects, the detection of the presence, absence or quantity of astrovirus in a subject can comprise detection of astrovirus in a sample from the subject.
[0014] In some aspects, the present teachings include detection of a murine astrovirus using one or more nucleic acid probes. A probe of these aspects can comprise, consist essentially of, or consist of a sequence having at least 70% sequence identity with a sequence of a murine astrovirus nucleic acid, or a complement thereof. In various configurations, a sequence having at least 70% sequence identity with a sequence of a murine astrovirus nucleic acid, or a complement thereof, can have at least 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity with a murine astrovirus nucleic acid, or a complement thereof. In various embodiments, a nucleic acid of the present teachings can be at least 10 nucleotides in length up to about 100 nucleotides in length.
[0015] In various embodiments, detection of a murine astrovirus can comprise a hybridization assay using a nucleic acid probe that hybridizes to a murine astroviral nucleic acid sequence under stringent conditions.
[0016] In various embodiments, detection of the astrovirus can involve the use of one or more nucleic acid probes including hybridization assays using a nucleic acid probe that hybridizes to a murine astroviral nucleic acid sequence under stringent conditions. Hybridization assays can include a southern blot, a northern blot, a dot blot, or a slot blot. In some aspects, murine astrovirus can be detected using a PCR assay such as an RT-PCR assay or a quantitative RT-PCR assay, or a sequencing-based assay such as a pyrosequencing assay.
[0017] In some embodiments, presence, absence, or quantity of astrovirus can be measured using an antibody probe that binds an astrovirus antigen to form an immune complex which can then be detected as to presence, absence or quantity of an immune complex.
[0018] In various embodiments, detecting a murine astrovirus in a subject can comprise a) providing a biological sample from the subject; b) contacting the sample with at least one antibody probe that binds at least one murine astrovirus antigen under conditions sufficient for formation of an immune complex comprising the at least one probe and the least one astrovirus antigen if present; and c) detecting presence, absence or quantity of an immune complex comprising the at least one probe and the at least one astrovirus antigen. In these embodiments, a sample can comprise astrovirus, or can be suspected of comprising astrovirus. An antibody probe can be a monoclonal or polyclonal antibody, or a portion thereof such as a Fab fragment. In some aspects, a murine astrovirus antigen can be a capsid protein or a portion thereof, or any other protein encoded by a murine astrovirus ORF, or a portion thereof. In some aspects, a murine astrovirus antigen can be immunologically cross-reactive with an astrovirus antigen hosted by another species. In various configurations, a murine astrovirus antigen of the present teachings can comprise, consist essentially of, or consist of at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, at least 14 or at least 15 contiguous amino acid residues of an astrovirus polypeptide. In various configurations, a murine astrovirus antigen of the present teachings can comprise, consist essentially of, or consist of a full length, isolated murine astrovirus polypeptide, such as, in non-limiting example, an astrovirus antigen such as a capsid protein that is expressed in a microorganism such as an E. coli or yeast, or in a mammalian, avian, or insect cell culture. In various configurations, a murine astrovirus antigen of the present teachings can comprise, consist essentially of, or consist of a murine astrovirus antigen of less than full length, such as, without limitation, an astrovirus antigen consisting essentially of or consisting of up to 100 amino acid residues, up to 90 amino acid residues, up to 80 amino acid residues, up to 70 amino acid residues, up to 60 amino acid residues, up to 50 amino acid residues, up to 40 amino acid residues, up to 30 amino acid residues, up to 25 amino acid residues, up to 20 amino acid residues, up to 15 amino acid residues or up to 10 amino acid residues.
[0019] In various embodiments, detection of astrovirus in a sample can comprise, without limitation, determining presence, absence or quantity of an antibody against astrovirus in a subject. In some aspects, determining presence, absence or quantity of an antibody against astrovirus can comprise providing a sample from the subject; forming a mixture comprising a) the sample or antibodies comprised by the sample, and b) at least one astrovirus antigen, under conditions sufficient for formation of an antibody/antigen complex between the at least one astrovirus antigen and an anti-astrovirus antibody if present; and c) detecting presence, absence or quantity of an antibody/antigen complex.
[0020] In some aspects, methods disclosed in the present teachings comprise obtaining a sample from a subject, and detecting presence, absence or quantity of astrovirus in the sample. In various embodiments set forth herein, a sample from a subject can be a body fluid sample, such as, without limitation, a blood sample, a serum sample, a plasma sample, a cerebrospinal fluid sample, and/or a solid tissue sample. In some configurations, a blood sample can be a peripheral blood sample. In various configurations, a sample can comprise fibroblasts, endothelial cells, peripheral blood mononuclear cells, haematopoietic cells and various combinations thereof. In some embodiments, a sample can be a solid tissue sample, or a fecal (stool) sample. In some embodiments, a sample can comprise or can be suspected of comprising astrovirus.
[0021] In various aspects of these methods, detecting, diagnosing, monitoring or managing astrovirus in a subject can comprise providing a biological sample from the subject, and contacting the sample with at least one primary probe that binds at least one astrovirus antigen under conditions sufficient for formation of a probe/antigen complex between the at least one astrovirus antigen and the at least one probe, and detecting presence, absence or quantity of a complex comprising the at least one probe and the at least one astrovirus antigen. In some configurations, a probe that can bind a murine astrovirus antigen can be an antibody against a murine astrovirus antigen. In some embodiments, a primary probe can be any molecule that can bind a structure or antigen comprised by a murine astrovirus, such as an astrovirus protein or polypeptide, or an epitope thereof. In various configurations, the binding between a primary probe and a murine astrovirus structure or antigen can have a binding constant Kd of 10 −5 or less, 10 −6 or less, 10 −7 or less, 10 −8 or less, or 10 −9 or less. In various embodiments, such primary probes can have high specificity, i.e., bind a murine astrovirus antigen with a binding constant less than that of a non-murine astrovirus antigen. Types of probes include, without limitation, an antibody, an antigen binding domain or antigen binding fragment of an antibody such as an Fab fragment, an aptamer (Jayasena, S. D., et al., Clinical Chemistry 45: 1628-1650, 1999), an avimer (Silverman, J., et al., Nature Biotechnology 23: 1556-1561, 2005) or any combination thereof. In various configurations, an antibody can be a monoclonal antibody, a polyclonal antibody or a combination thereof, and an aptamer can be an RNA aptamer, a DNA aptamer, a peptide aptamer, or a combination thereof. In various aspects, detection of binding of a probe to a polypeptide can comprise detecting a label bound directly or indirectly to the probe. A label can be any label known to skilled artisans, such as, for example, a radioisotope, a chromophore, a fluorophore, a quantum dot, an enzyme and a resonance light scattering (RLS) particle. In some configurations, an astrovirus antigen can comprise a contiguous sequence of at least 4 amino acids, at least 5 amino acids, at least 6 amino acids, at least 7 amino acids, at least 8 amino acids, at least 9 amino acids, or at least 10 amino acids of an astrovirus polypeptide.
[0022] In some embodiments, the present teachings include an antibody against an astrovirus such as a murine astrovirus, and methods of generating such antibodies. In various configurations, these methods include providing an astrovirus antigen such as a capsid antigen, inoculating a host animal such as, in non-limiting example, a mouse, a hamster, a rat, a rabbit, or a bird (e.g. a chicken or duck), and collecting body fluid such as, for example, blood, plasma, serum, from the animal to obtain a polyclonal antiserum (or egg yolk from a bird to obtain an IgY antibody, see Schade, R., et al., Altern. Lab Anim. 33: 129-154, 2005). Alternatively, a monoclonal antibody against an astrovirus antigen such as a capsid protein can be generated using established methods (see, e.g. Kohler G, Milstein C., Continuous cultures of fused cells secreting antibody of predefined specificity, Nature 256: 495-497, 1975; Schreiber, R. D., et al., J. Immunol. 134: 1609-1618, 1985; Harlow, E., Using Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1999). In various embodiments, an astrovirus itself can be a source of antigen. Alternatively, an astrovirus antigen can be an astrovirus protein expressed by recombinant means. For example, an astrovirus capsid protein or a portion thereof encoded by a plasmid vector can be expressed in a prokaryote such as E. coli , and the recombinant polypeptide can serve as antigen for generating an antibody.
[0023] In some configurations of the present teachings, detection of binding between the at least one antibody and at least one astrovirus antigen can comprise any binding detection method known to skilled artisans, such as, without limitation, an immunoprecipitation, a radioimmunoassay, a Western blot, an ELISA or a flow cytometry (FACS) assay.
[0024] Various configurations of the present teachings include methods of detecting, diagnosing, monitoring or managing an astrovirus infection or astrovirus-related disease. In various aspects, these methods comprise contacting a sample or antigens thereof with at least one probe that binds at least one astrovirus antigen under conditions sufficient for formation of a complex comprising the at least one probe and the least one astrovirus antigen if present. In various configurations, the methods can comprise a) contacting a biological sample with a solid surface that binds at least one astrovirus antigen; and b) subsequent to a), contacting the surface with at least one probe. In some configurations of these aspects, the detecting presence, absence or quantity of a complex can comprise quantifying the at least one probe bound to the surface subsequent to b). In some configurations, the at least one probe can comprise a label, and the detecting presence, absence or quantity of a complex can comprise quantifying the label, which can be any label known to skilled artisans such as an enzyme, a radioisotope, a fluorogen, a fluorophore, a chromogen, or a chromophore.
[0025] In various embodiments, detection of binding between at least one probe directed against an astrovirus antigen, and an astrovirus or astrovirus antigen comprised by a sample can comprise direct detection, i.e., detection of a label comprised by the at least one probe, such as detection of a radioisotope or fluorophore comprised by the at least one antibody.
[0026] In various embodiments, detection of binding between at least one antibody directed against an astrovirus antigen (a “primary” antibody or probe), and an astrovirus or astrovirus antigen comprised by a sample can comprise indirect detection, comprising detection of a label comprised by a secondary probe such as a secondary antibody directed against the primary antibody, a labeled avidin, a labeled streptavidin, or a labeled anti-biotin antibody for detection of a primary probe that is tagged with a biotin, or a labeled anti-digoxygenin antibody for detection of a primary probe that is tagged with a digoxygenin.
[0027] In various configurations, an antibody or probe of these aspects can further comprise one or more labels, such as an enzyme, a radioisotope, a fluorogen, a fluorophore, a chromogen, or a chromophore.
[0028] A radioisotope of the various configurations can be any radioisotope known to skilled artisans, such as, for example, 3 H, 14 C, 32 P, 33 P, 35 S, or 125 I.
[0029] A fluorophore of the various configurations can be any fluorophore known to skilled artisans, for example a fluorescein, a rhodamine, a coumarin, an indocyanine, or a green fluorescent protein (GFP).
[0030] An enzyme of the various configurations can be any enzyme for which a suitable substrate is available, such as, for example, alkaline phosphatase, a horseradish peroxidase or a chloramphenicol acetyltransferase. A suitable substrate is a substrate that, when contacted by an enzyme, produces a product that is detectable by methods known to skilled artisans. For example, the substrate can be a chromogenic substrate, such as, for example, p-dinitrophenyl phosphate as a substrate for alkaline phosphatase, or diaminobenzidine as a substrate for horseradish peroxidase. An enzyme substrate can alternatively be, in various configurations, a fluorogenic substrate, such as, for example, disodium 4-methylumbelliferyl phosphate substrate for alkaline phosphatase, or a chemiluminescent substrate, such as, for example, 5-amino-2,3-dihydrophthalazine-1,4-dione (luminol) for horseradish peroxidase, or disodium 3-(4-methoxyspiro{1,2-dioxetane-3,2′-(5′-chloro)tricyclo[3.3.1.13,7]decan}-4-yl)phenyl phosphate for alkaline phosphatase.
[0031] A hapten of the present teachings can be any hapten for which a probe is available. For example, the hapten can be a biotin, detectable with an avidin, a streptavidin, or an anti-biotin antibody, or a digoxigenin detectable with an anti-digoxigenin antibody, by methods well known to skilled artisans.
[0032] In various configurations, a sample can be a biological sample obtained from a subject, such as a biological fluid sample or a biological tissue sample. A biological fluid sample can be, without limitation, a blood sample such as a sample comprising peripheral blood mononuclear cells (PBMCs), a plasma sample, a serum sample, a cerebrospinal fluid sample, a urine sample, or a saliva sample. A fluid sample can comprise cells, or can be cell-free. In some configurations, a fluid sample can be a peripheral blood sample. In some configurations, a sample can be a fecal (stool) sample.
[0033] In various configurations, a sample would be a cell culture sample, such as, for example, a culture supernatant from an astrovirus-infected culture, or a sample comprising cells from such a culture.
[0034] In various aspects of the methods, detecting astrovirus in a subject can comprise detecting presence, absence or quantity of antibodies against murine astrovirus in a sample from the subject, such as a fecal sample, a blood sample, a serum sample, a plasma sample, or a cerebrospinal fluid sample. These methods can include contacting a sample with a murine astrovirus or an astrovirus antigen such as, for example a polypeptide component of an astrovirus or a peptide comprising an epitope of a murine astrovirus polypeptide, and detecting formation of a binding complex comprising antibody comprised by the sample and the astrovirus or astrovirus antigen. In some embodiments, a murine astrovirus or astrovirus antigen can be immobilized on a solid support. In some configurations, a solid support can be, without limitation, an ELISA plate, a bead, a dip stick, a test strip or a microarray.
[0035] In some configurations, methods of the present teachings can comprise providing a solid surface to which one or more antigens comprised by a sample are bound, contacting at least one probe to the solid surface under conditions sufficient for formation of a complex comprising at least one probe and one or more astrovirus antigens, and detecting presence, absence, or quantity of a complex comprising the at least one probe and at least one astrovirus antigen. In various configurations, the detecting can comprise an ELISA, a radioimmunoassay, a Western blot assay or a flow cytometry assay. In some embodiments, presence, absence or quantity of a complex comprising at least one astrovirus antigen and at least one probe can be determined by immunoprecipitation.
[0036] In various embodiments of the present teachings, the inventors disclose methods of detecting, diagnosing, monitoring or managing astrovirus in a subject in a seroconversion-type assay. In various aspects, these methods can comprise providing a sample from the subject, and forming a mixture comprising the sample and at least one murine astrovirus antigen under conditions sufficient for formation of an antibody/antigen complex between the at least one murine astrovirus antigen and an antibody, and detecting presence, absence or quantity of an antibody/antigen complex, wherein the sample comprises circulating antibodies from the subject. In various configurations, a sample can be a body fluid sample, such as a sample comprising circulating antibodies. In various configurations, a sample can be a blood sample, a plasma sample, a serum sample, a cerebrospinal fluid sample, a fecal (stool) sample or a combination thereof. In various aspects, detecting the presence, absence or quantity of an antibody/antigen complex can comprise contacting the mixture with at least one probe directed against a circulating antibody under conditions sufficient for formation of a probe/antibody complex; and detecting presence, absence or quantity of the probe. In some configurations, the probe can be directed against murine immunoglobulin, and can be, for example, an antibody, an antigen-binding fragment thereof, an aptamer or an avimer. In some configurations, the probe can comprise a label. In some configurations, the at least one astrovirus can be immobilized on a solid support.
[0037] In various embodiments of the present teachings, the inventors disclose vaccines against astrovirus infection. In these embodiments, a vaccine can comprise, consist essentially of, or consist of a murine astrovirus antigen, or a portion thereof. In some embodiments, a vaccine can comprise a vector comprising a murine astrovirus nucleic acid that encodes an entire open reading frame of a murine astrovirus polypeptide, or a portion thereof. A vector can be, for example, an adeno-associated virus (AAV) such as, without limitation, an AAV5 vector.
[0038] In various embodiments of the present teachings, the inventors disclose methods of testing vaccines and anti-viral agents against astrovirus infection. In a typical protocol for a murine model, a vaccine or pharmaceutical agent would be administered to mice in a pre-treatment or treatment protocol, the mice would then be exposed to murine astrovirus through administration of the virus and/or through contact or co-housing with animals known to be infected with astrovirus. Outcomes of exposure would then be monitored.
[0039] In assessing a vaccine, the vaccine would be administered to infected mice and the effect of vaccination on the course of the infection monitored. Vaccine administration can be prior to administration of an astroviral challenge, at the about the same time or after administration of the astroviral challenge. The astroviral challenge can comprise, consist essentially of, or consist of administration of a preparation containing the astrovirus to one or more subject mice, exposure of a mouse or mice to an infected mouse or mice by co-housing or by any other suitable method that exposes an animal to the astrovirus.
[0040] A vaccine can comprise a murine astrovirus antigen, or a portion thereof. In some embodiments, the vaccine can comprise a vector comprising a murine astrovirus nucleic acid that encodes an entire open reading frame of a murine astrovirus polypeptide, or a portion thereof. A vector can be, for example, an adeno-associated virus such as, without limitation, an AAV5 vector.
[0041] In assessing a pharmaceutical agent, the agent can be administered after administration of the astroviral challenge. Any of a wide variety of agents can be tested in the model.
[0042] A candidate agent can be a candidate vaccine or a candidate pharmaceutical agent including synthetic, naturally occurring, or recombinantly produced molecules. Non-limiting examples include small molecules such as known anti-virals; drugs; peptides; antibodies (including antigen-binding antibody fragments, e.g., to provide for passive immunity) or other immunotherapeutic agents; endogenous factors present in eukaryotic or prokaryotic cells (e.g., polypeptides, plant extracts).
[0043] In various embodiments, candidate agents can encompass numerous chemical classes, though typically they are organic molecules, preferably small organic compounds having a molecular weight of more than 50 and less than about 2,500 Daltons. In some embodiments, candidate agents can comprise functional groups necessary for structural interaction with proteins, for example hydrogen bonding, and can include, for example, an amine, a carbonyl, a hydroxyl or a carboxyl group, preferably at least two functional chemical groups. In some configurations, a candidate agent can comprise cyclical carbon or heterocyclic structures and/or aromatic or polyaromatic structures substituted with one or more of the above functional groups.
[0044] Candidate agents can also be found among biomolecules including, but not limited to: peptides, saccharides, fatty acids, steroids, purines, pyrimidines, derivatives thereof, structural analogs thereof or combinations thereof.
[0045] Candidate agents can be obtained from a wide variety of sources including libraries of synthetic or natural compounds. For example, numerous means are available for random and directed synthesis of a wide variety of organic compounds and biomolecules, including expression of randomized oligonucleotides and oligopeptides. Alternatively, libraries of natural compounds in the form of bacterial, fungal, plant and animal extracts are available or readily produced. Additionally, natural or synthetically produced libraries and compounds are readily modified through conventional chemical, physical and biochemical means, and can be used to produce combinatorial libraries. Known pharmacological agents can be subjected to directed or random chemical modifications, such as acylation, alkylation, esterification, amidification, etc. to produce structural analogs.
[0046] The outcome of infection can be monitored by any of a variety of methods including detection the presence, absence or quantity of astrovirus in a sample from an infected mouse, measuring immunochemistry aspects such as antibody produced in response to infection, detecting any symptomotology or any other suitable method.
[0047] The present teachings include, without limitation, the following aspects:
[0000] 1. An isolated polynucleotide comprising, consisting essentially of, or consisting of a nucleotide sequence that is at least 70% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, and wherein a virus comprising said polynucleotide is infectious towards a mammal.
2. An isolated polynucleotide in accordance with aspect 1, wherein the nucleotide sequence is at least 75% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4
3. An isolated polynucleotide in accordance with aspect 1, wherein the nucleotide sequence is at least 80% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
4. An isolated polynucleotide in accordance with aspect 1, wherein the nucleotide sequence is at least 85% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
5. An isolated polynucleotide in accordance with aspect 1, wherein the nucleotide sequence is at least 90% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
6. An isolated polynucleotide in accordance with aspect 1, wherein the nucleotide sequence is at least 95% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
7. An isolated polynucleotide in accordance with aspect 1, wherein the nucleotide sequence is 100% identical to any one of SEQ ID NO:1, SEQ ID NO.2, SEQ ID NO:3, and SEQ ID NO:4.
8. An isolated polynucleotide in accordance with aspect 1, wherein the mammal is a primate.
9. An isolated polynucleotide in accordance with aspect 1, wherein the primate is a human.
10. An isolated polynucleotide in accordance with aspect 1, wherein the mammal is a rodent.
11. An isolated polynucleotide in accordance with aspect 10, wherein the rodent is a mouse.
12. An oligonucleotide comprising, consisting essentially of, or consisting of a sequence consisting of about 10, from 10 to 70, or about 70 nucleotides, wherein said oligonucleotide hybridizes to a nucleic acid of a murine astrovirus or the complement thereof under high stringency conditions (Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, 3rd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 2001; Ausubel, F. M., et al., ed., Current Protocols in Molecular Biology, Wiley Interscience, 2003).
13. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide comprises, consists essentially of, or consists of a sequence consisting of about 10, from 10 to 60, or about 60 nucleotides.
14. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide comprises, consists essentially of, or consists of a sequence consisting of about 10, from 10 to 50, or about 50 nucleotides.
15. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide comprises, consists essentially of, or consists of a sequence consisting of about 10, from 10 to 40, or about 40 nucleotides.
16. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide probe comprises, consists essentially of, or consists of a sequence consisting of about 10, from 10 to 30, or about 30 nucleotides.
17. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide probe comprises, consists essentially of, or consists of a sequence consisting of about 10, from 10 to 20, or about 20 nucleotides.
18. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide comprises, consists essentially of, or consists of a sequence consisting of about 15, from 15 to 60, or about 60 nucleotides.
19. An oligonucleotide in accordance with aspect 12, wherein the oligonucleotide comprises, consists essentially of, or consists of a sequence consisting of about 20, from 20 to 60, or about 60 nucleotides.
20. An oligonucleotide selected from the group consisting of
[0000] (SEQ ID NO: 6) CCAAGAAAGAGGCACTAGTGGCACTC; (SEQ ID NO: 7) GTTTTTTTTTTTTTTTTTTTTTGCCAATTTTTATGCCAATTATATCACC C; (SEQ ID NO: 8) TACATCGAGCGGGTGGTCGC; (SEQ ID NO: 9) GTGTCACTAACGCGCACCTTTTCA; and (SEQ ID NO: 10) TTTGGCATGTGGGTTAA.
21. A nucleic acid-based vaccine, comprising a vector comprising a murine astrovirus sequence encoding an astrovirus polypeptide or a portion thereof, wherein the vector is other than a murine astrovirus.
22. A method of detecting presence, absence or quantity of an murine astrovirus in a biological sample, the method comprising:
[0048] providing a sample comprising or suspected of comprising an astrovirus;
[0049] contacting the sample with at least one nucleic acid that is complementary to a nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, under hybridization conditions; and
[0050] detecting the presence, absence or quantity of a hybrid nucleic acid comprising the probe and the astrovirus nucleic acid.
[0000] 23. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 22, wherein the nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, has at least 75% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof.
24. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 22, wherein the nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, has at least 80% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof.
25. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 22, wherein the nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, has at least 85% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof.
26. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 22, wherein the nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, has at least 90% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof.
27. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 22, wherein the nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, has at least 95% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof.
28. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 22, wherein the nucleotide sequence that has at least 70% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof, has 100% sequence identity with an astrovirus nucleic acid sequence, or the complement thereof.
29. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with any one of aspects 22-28, wherein the detecting comprises a quantitative PCR assay.
30. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with aspect 29, wherein the quantitative PCR assay is a quantitative RT-PCR assay.
31. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with any one of aspects 22-28, wherein the detecting comprises a pyrosequencing assay.
32. A method of detecting presence, absence or quantity of an astrovirus in a biological sample in accordance with any one of aspects 22-28, wherein the detecting comprises a hybridization assay selected from the group consisting of a southern blot, a northern blot, a dot blot, and a slot blot, and a RACE assay.
33. A method according to any one of aspects 22-32, wherein the diagnostic sample is selected from the group consisting of a fecal sample, a vomitus sample, a tissue sample and a blood sample.
34. An isolated polypeptide comprising, consisting essentially of, or consisting an amino acid sequence at least 70% identical to at least 4 contiguous amino acids of a polypeptide encoded by an open reading frame comprised by a nucleotide sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
35. An isolated polypeptide in accordance with aspect 34, wherein the nucleotide sequence is at least 75% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4
36. An isolated polypeptide in accordance with aspect 34, wherein the nucleotide sequence is at least 80% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
37. An isolated polypeptide in accordance with aspect 34, wherein the nucleotide sequence is at least 85% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
38. An isolated polypeptide in accordance with aspect 34, wherein the nucleotide sequence is at least 90% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
39. An isolated polypeptide in accordance with aspect 34, wherein the nucleotide sequence is at least 95% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
40. An isolated polypeptide in accordance with aspect 34, wherein the nucleotide sequence is 100% identical to any one of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4.
41. An isolated polypeptide in accordance with aspect 34, wherein the mammal is a primate.
42. An isolated polypeptide in accordance with aspect 41, wherein the primate is a human.
43. An isolated polypeptide in accordance with aspect 34, wherein the mammal is a rodent.
44. An isolated polypeptide in accordance with aspect 45, wherein the rodent is a mouse.
45. An oligopeptide comprising, consisting essentially of, or consisting of at least 4 up to 60, or about 60 amino acid residues of a murine astrovirus antigen.
46. An oligopeptide in accordance with aspect 45, wherein the oligopeptide comprises, consists essentially of, or consists of up to 50, or about 50 amino acid residues.
47. An oligopeptide in accordance with aspect 45, wherein the oligopeptide comprises, consists essentially of, or consists of up to 40, or about 40 amino acid residues.
48. An oligopeptide in accordance with aspect 45, wherein the oligopeptide comprises, consists essentially of, or consists of up to 30, or about 30 amino acid residues.
49. An oligopeptide in accordance with aspect 45, wherein the oligopeptide comprises, consists essentially of, or consists of up 20, or to about 20 amino acid residues.
50. An oligopeptide in accordance with aspect 45, wherein the oligopeptide comprises, consists essentially of, or consists of up to 15, or about 15 amino acid residues.
51. An oligopeptide in accordance with aspect 45, wherein the oligopeptide comprises, consists essentially of, or consists of up to 10, or about 10 amino acid residues.
52. An oligopeptide in accordance with any one of aspects 34-51, further comprising a label.
53. An oligopeptide in accordance with aspect 52, wherein the label is selected from the group consisting of a fluorphore, a hapten, an enzyme and a radioisotope.
54. An antibody directed against a polypeptide or oligopeptide of any one of aspects 34-51.
55. A method of detecting presence, absence or quantity of an astrovirus in a biological sample, comprising performing a virus detection assay selected from the group consisting of a cytopathic assay, an antibody assay and a protein detection assay.
56. A method according to aspect 55, wherein the cytopathic assay is selected from the group consisting of a dye exclusion assay, an enzyme release assay and an apoptosis assay.
57. A method according to aspect 55, wherein the antibody assay is selected from the group consisting of a Western blot assay, an ELISA assay, an immunofluorescence assay, an immunoprecipitation assay and a radioimmunoassay.
58. A seroconversion assay for detecting a murine astrovirus in a murine subject, comprising:
[0053] providing a serum or plasma sample from a subject;
[0054] contacting the sample with an oligopeptide of any one of aspects 45-53; and
[0055] detecting presence, absence or quantity of a complex comprising the oligopeptide and antibody that binds the oligopeptide.
[0000] 59. A method for screening a candidate agent for anti-viral activity against an astrovirus, the method comprising:
a) providing a mouse susceptible to a disease or condition caused by the astrovirus;
b) infecting the mouse with the astrovirus;
c) administering the candidate agent to the mammal; and
d) monitoring indices of infection wherein decreased indices of infection indicates anti-viral activity against the astrovirus.
60. A method according to aspect 59, wherein the astrovirus is MoAstV.
61. A method according to aspect 59, wherein the candidate agent is a vaccine.
62. A method according to aspect 59, wherein the candidate agent is pharmaceutical agent.
63. A method according to aspect 59, wherein the mouse is an immunocompromised mouse.
64. A method according to aspect 60, wherein the mouse is a MuMT or RAG1 −/− mouse.
65. A method according to aspect 59, wherein the monitoring comprises detecting presence, absence or quantity of an astrovirus in a biological sample obtained from the mouse by performing a virus detection assay according to any one of aspects 22-33 or 55-57 wherein absence or decreased quantity of astrovirus indicates antiviral activity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] FIG. 1 illustrates a comparison between identified astrovirus sequences.
[0057] FIG. 2 illustrates a schematic of the identified astrovirus genomes.
[0058] FIG. 3 illustrates detection of astrovirus in immunocompromised mice by PCR.
[0059] FIG. 4 illustrates that adaptive immune response is required to control astrovirus replication.
[0060] FIG. 5 illustrates that astrovirus can be detected in commercially available mice.
[0061] FIG. 6 illustrates antibody responses during murine astrovirus infection.
[0062] FIG. 7 illustrates genetic diversity of murine astroviruses identified by next generation sequencing.
[0063] FIG. 8 illustrates kinetics of murine astrovirus shedding.
[0064] FIG. 9 illustrates an AstV (astrovirus virus-like particles) ELISA validation.
[0065] FIG. 10 illustrates a second AstV (astrovirus virus-like particles) ELISA validation.
[0066] FIG. 11 illustrates an AstV (astrovirus virus-like particles) ELISA screen.
DETAILED DESCRIPTION
Methods
[0067] Methods and compositions described herein utilize laboratory techniques well known to skilled artisans. Such methods and compositions can be found described in laboratory manuals such as Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, 3rd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 2001; Spector, D. L. et al., Cells: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1998; Harlow, E., Using Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1999; Ausubel, F. M., et al., ed., Current Protocols in Molecular Biology, Wiley Interscience, 2003; Nagy, A., et al., Manipulating the Mouse Embryo: A Laboratory Manual (Third Edition), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 2003. Methods of administration of pharmaceuticals and dosage regimes, can be determined according to standard principles of pharmacology well known skilled artisans, using methods provided by standard reference texts such as Remington: the Science and Practice of Pharmacy (Alfonso R. Gennaro ed. 19th ed. 1995); Hardman, J. G., et al., Goodman & Gilman's The Pharmacological Basis of Therapeutics, Ninth Edition, McGraw-Hill, 1996; and Rowe, R. C., et al., Handbook of Pharmaceutical Excipients, Fourth Edition, Pharmaceutical Press, 2003. These publications are incorporated herein by reference, each in its entirety.
[0068] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. Examples presented herein are illustrative and are not intended to be limiting to the scope of any claim.
[0069] Sequences of murine astroviruses of the present teachings include the following:
[0000]
>Mouse_Astrovirus_STL_CY1_20120531_Update
(SEQ ID NO: 1)
CCAAGAAAGAGGCACUAGUGGCACUCCUGCUGCUAGUAAGUCUGACAUGGCCCUG
CGUAAGGAGUAUACUUCCCUUGUGGACCAAGCGGUCGACGCUGGGAAUUACCUG
GCCCGCUGCCAGUUGCCAACUACGGCAAUUCUGCUGCUGCGCAAUAUGCCUGACC
ACUAUCCUAACCGGCCUUGGUCUGUCCAUUCGACCCCCCGCCAUUUGGUCUAUCC
CUCAACAACGGAUGAUCCAAAGACGCGGGUUAUAACAGCCUCCUCCGUCACAGUG
GAGGAUGAAUGGGUGACCUAUGUCUGGACCGGCGCGCGCUGGCAGCAGGUGGCA
ACGGCCCCUGACUGUGGAAAAACGAUCCUGGUCUGUGCCCUCCUGAACGAACAUA
AGCGGCUCAAGGAUGAGAAUGCAAGCCUUAAACUUGCCAAGGCGAAUUUGGAGG
UUGAUAACACCACACUGCGGGUGGCGUCAGCGGCCAUUACCAACUCGGCCCCUCG
CCGUUCGCGCCUCCCUUGGAUCCUGGCACUCUUGGCUGUGCUUUUCUCCCUCCUC
ACGACCUCGGCUGCCUUUGAAACCAGCUCUACCUCACGGAGCUAUGCCCCUGAGG
AUAUUGCUAGGCACUCUGAGGAUUUGAACACCUUUAUUGAGAACGCUUUGAGGG
UGAACCACACACGCUCCUACACAGAGUACACCUACCAACUGUACGCCACACAUGC
UCAGACUUUCUUGGACCGCAUGGCCUUGACAUUUAACACCUGGCAAGCUUAUGAU
CCGCACUUCUUUGCGAAAACACCCUUGCAAAGUGCGCUUCUGAGUGUCCUCCAGU
AUGUAACACCCUGGACGUGGGAGAUAGCCCUUACGGGCUUGGUAUUGGCGCUCA
UGCUAGCGGAAAACUCUAGCCCUUGGUCGCUGCUCUACCUGGCCUGUGCUACUCU
CACAAGGACCCGCUUUGCCCUCUUGGCCGUGGCGCCCUUCCAGACACGCUACACG
ACGGCUGUCACCGUUGCCGCCUCGGUGCUCUACGCACUCGACCCCUUGGUCGCAG
UGGCGUGCCUGGUGCUACACCUCUUUCUCCUGGCAGUGGUGGGGCUCUUCAUGGA
GGAUACCUCCUAUGUCCAAAACUUGAAGGGCGCCUUCCUGCUGCUAUGCGCCUUC
UUCGGCCAUGCCCUCUGUGCCUCUUCGGAGUGAGCUCGGCGCCAGUCACAACAC
UAGCUGUUGCCUGGCGGAUCUGGCGGCUACUCUCUCGUGCCGGAACAACAGGCAC
CGUGGAGGUGCGCAAUGAAGAAGGCAAGGUGGUCUCAAAACAGACCACGCAACCC
AACUUCCUCUUCCGCUUCAAGCAGGCGUUGAGGAGGAUGAGACAACUCAGAACGA
CCCAGACCCCCCUAGCGCGCGUCAAUCCUGAUGCGCUCUGCCACAUCAGCGUGGC
CGGGGCGAAAGGCACUGGCUUCUUUUGUGGUAACUACGCUGUGACAUGUGCACA
CGUAGUCGGGAGUGAGACAGUCGUCAACCUGUGCUAUAAAGGCCGUAACUAUCA
GGCCCCAGUGAAGAAAAUCCUGGAGCAAAAGGAUGUGGCACUCAUUCCCAUACCU
GCGGGGAUAACACCACCCCGCUUGAAGAUCUCCAAGAAGCACUGCUGCGACUGGG
UCUGUGUCUGUGCCCCCGACGGUGAUGGUGCCUACCUAACUGCUGUGACUGAGGG
UUGCGAGCAUGAUGGUCACUACUCCUAUGCCUGCCCGACGCGGGAUGGGAUGUCU
GGCGCUCCUCUGUUAGACAUAGAUGGCCAUGUUCUUGGGAUACACACUAACAACA
CUGGCUACACUGGUGGUGCCCAACGCCUCGACCUUGAGGACAUAGUUGAAGCCCC
CAAGCCAAAUCCCAAGCAGCUCGCCCUCGAGAGGGAGAUUGAAGAACUGAAAAAG
CAGCUUGCGGCCCUGCAGCCUGAACCACCUAGGCCUGAGCCCGUGGCUGCCCCUC
CCUCACCCGUUCAGCCCGGCCCCCUAGUGGUUCCAACUACCUGCCCCCCUCCAGCC
CCACCGGCACCAACUGUGGCCCCUGCUCCUGUGGCCCCCAGCCCUGUGGCGCACU
AUGUGGUCAAACCCACCCAAAUUCCACCUAUGCAACAAAGCCUAACAACUAGUGA
UGUGGUGGAUCUUGUGCGUGCGGCAAUGGGUCGUGAGAUGCAAAUCCUGCGGGA
CGAGCUGAACCUGAUGAAUCAGGCUAAAGGGAAGACCAAACGUGGCCGUGGGAA
GAAGCAUACCAUCGGGGCUCGUGUUGGUGGCCGUCGCAGACAGCGUGGGCCUGCC
UUCACCGAGGAGGAGUACAAGGAGAUGCUGGACCAAGGGAUUGACCCCGAUGAG
AUCAAGCGCCUAGCCGAAGACCUCUGGGAGGACCAGACUGGCUUCCCGGAGUGGA
GUGACCCUGAGUUCUCUGAUGAGGACGAUGGUUGGACACCAAAGACCCAUGACU
GGCUAGACUUUGAUUAUGAGGAUGAUUUGGAACAAACUUACGUCCCIUGGUCCCU
GGGCCCAGAAAUGCAAGAUACCUCUCGUCGACUACGUCAAGAAGAUCUUUGACAA
AGGCUCCGUUGAUGAGAUGUUACAAAAUCUUGCCCCUCUGGAGAAGAAGCUCUG
UAGGAAACAACUUGAGGCCGUUCGCCAGGCAAAAACUGAUAUCGAGCUCUCUGU
UGCACUUGGCGCUUUGGAUCGUCGUGCUGCCGAUGUGGGCAUGCAGCCCUUUACA
CCAGGGCUAGAGUAUAAACAAGCUGUUCCAAAAAACGCCAAGGGCCCCCGCAAGG
GGGCAAAAGAUCAGGGCUCGAAGACUGGAAAGAACUAAGGCAGCCCCCCUUUCGC
CUCCUGGUACCCCAGCCUUACCCUGUUGUCUGCAGCUUACCCCUGGACCGGCCCA
UCUAUGACAACGAUGAGCCUAAAGAUCCACUUCUGGGGGUGUUGCCACAUGUAG
ACUAUGAGGGUAACUUUGCACCAACAACCUGGGGAGGCGCAGCUUACGCGAAGA
GUUUCGAGAAGUUCACGUAUGCUCAACCUGUGGACUUCGAAAAGCACUAUCCUG
UAGAAACUCAGUUCGCUGACUGGGCCUGGCGAGUCCACCACGCUUACCUGGAAGG
CACUCGGGUAUGCCACAUCAUGUCUACAGAGAAAAAUACCGACUCAACCCCUGCC
UACCCCAAAUGCCUGGACUACUCCACCGAGGCCGACUACCUAGAGGAACAUGGCU
GGGAGCCCUAUGUCAACGCUUUCCGUGCCAUUGACUCCGGGGAGCGGCCCCAGGU
UCUCUGGUUCCUCUUCUUGAAGAAGGAGAUUCUCAAACAAGAGAAGAUUCGCGA
UUCAGACAUUCGUCAGAUUGUCUGUUCAGAUCCCAUCUAUGCGCGGAUCGGAGCU
UGCUUCGAACAACAUCAAAACCAUCUCAUGAAGCAAAAAACAGAGACCCAUUCCG
GGCAAUGUGGCUGGUGCCCCCUGAAGGGGGGCUUUGAGGCAAUGUGCCACCGUCU
UGCCUCUAAGCAGGGUGUCUUUGUGGAAUUUGACUGGACACGCUUUGAUGGAAC
AAUCCCCGUACAACUCUUCCGCAGGAUAAAGAAGCUCCGCUGGUCCAUGAUUUGU
CCCGAACAUCAGCAGCGCUACGGGCACAUGUACCAGUGGUAUGUUAACAAUCUCU
UGCACCGCUACACCGUGCUGCCCUCAGGUGAGGUGACCAUCCAAACUCGUGGCAA
CCCCUCAGGGCAAAUCUCAACAACAAUGGAUAACAACAUGGUUAACUACUGGCUU
CAGGCAUUUGAGUUCUGCUACUUCUUUGGCCCUGAUAAAGAUCUCUGGCGGCAG
UAUGAUACUGUCUGCUAUGGUGAUGACCGGCUUACGCGCUACCCUGUGCUACCAC
CCCAUUACAUCGAGCGGGUGGUCGCCAUGUACAAGGACAUCUUUGGCAUGUGGG
UUAAACCUGAAAAGGUGCGCGUUAGUGACACCCUGGUUGGUCUCACCUUUUGUG
GCUUUAGAAUAGGGGAGCACUAUUUGCCCUAUCCUGCACAGGAAGACAAACUCU
UUGCCGGCCUCGUCCGGCCAGUGAGGAAAUUGGCUGACUUUAAAACACUCCAUGG
GAAACUCUUGAGCCUGCAGCUUCUGAUGCACUUCCACCCUCCGAGUCCCUUUAAG
GACUACUUGGAGAUGUGCUUGGCAAACACCGCCAAGUACUGCCCGGAACUUCCGG
CGCGGUUUUCAGAGCGUCAGAUGGACAAGCUUUGGAGGGGAGGACCAAAAGCUG
UUCAUGGCUAAGGCCAAACAACAACAGAAAAAUGCCACGACCGUCACUACUACAA
CUGUCACUGGUCGCAGUAGUCGGCGGUCUCGCAGGCGCUCUGUACGGCGCCGCGC
UGCAGGCCCUUCUAACCCCCCAACAAAGACAACAACUGUUCGGACUGUUUUUCGC
CGCACUGCCCGGCCUCGCGGUGAUCGCCGCAGGAGUAGGAAUGCUCAGCGGCAGG
CUCCUCGCGAGGUUGUUCAGACGGUUACGGCGACCCUCGGAACGGUUGGCGCGAA
CCAGGGCAAUCAGGUCGAGCUUGAGAUGGCAGCGCUCCUCAACCCAGCGCUAAUU
AAAGAAACAACUGGCUCAAACGCCUUCGGACCACUCCAGAUGUAUGCCUCCACGC
AUGCCAUGUGGAAAGUGGAUAGGCUCACACUCAAGCUCACCCCUCUGGUCGGCGC
CUCUGCUGUUUCCGGUACAGCGGUCCGUGCCUCACUGAAUAUGACAUCUGGGCCC
GCCGCGCCCGCCUGGUCAGCCUUGGGCGCGCGGAAGCAUGUGGACACCAAUCCUG
GUCGGCCGGCUUCCUUCACCCUCACAGCCGCCGAUGUACCUGGCCCCAAGCAGGG
UUGGUUCUUUACUAAUACUAAGCAGGAGGCCGGCUUUACAGUCGGCGGGGCCAU
UGAGAUCCAUACCCUCGGCAAGACGAUGUCAACCUACCAGAACUCAGCCUAUACG
GGCCCACUCUUUCUUGCCGAGGUCACAGGUACCUGGAGGUUUAAGAACUACGAGC
CCCAGCCCGGCUUGCUCAACCUCCUCAAGACCGAGGUUAAAGAGCCUGCGGGCAC
UGUGAAGGUACACUCCAAACCUGGAGAACCUGUCACGCUCUCCAUCCCUCAAGCA
GGGACCUUUGCUGGCCUAGAGAGGCUAAAUCCAACAGCCUCGGCCACACCAGGUG
AGAUCAUCUGGGAGGUAGUGGAUUCCGCUGCGAAUGCGGUCUCCGGCUUGCUUCC
UCAACCCUGGCAGUGGCUUUUUAAAGGCGGCUGGUUCUUCCUGAAAAGAAUUGC
CAACCGGAAACCUGUUGGUGCCGCCAGUGUGGCGGGUGAACCUGAUGGAGGUGA
AGUGACUUUCCGCGUGUACGCCAGUAUCGCGGAUGCCCAGAAUGAUGUGCCCUGU
AUUGCCAGCUCGGCGGCCUCCACUCAAUCCAUACAGACGGAGGGUCUCAAGAUCU
CCCAGGUGACUCCUGGGACCAUUGGUAUGCCUGAAACUGCAGUAGCCACACACAA
CAUGGCUCCACCACCCGAGUCCGGACCCUAUACCUAUCAAGGGCCCACCUUGGAG
GCUGCUGCUCCUUUGCACGCCCCCAAGUAUACACAGUGGACUAUUGUAGAUGCUG
GUACCUCCCAGGAGCAGGCCCGCCUGCGCUCCGGGGUGGUCCCAGCAGAGCAGAC
CUCAGCCUGGUCGAGCUGUACUCUGGAGCUCCCAGGCACCUUCCUCCAGAAUAUG
UAUGAGAUUGAUCCCCGUGAUAUUGCAGCCGGUACCUUUCCCAUCAAUCACUGGA
ACGUGAGCACCUCGCGGCUCACGCGGCUUGGCACCGCCUACGGUUGCAAUCAGGC
GCGGGUCCGCACCUAUGGGGAGGGAGUCCCGCAUGUGGUUAUCUCUACCACUUCU
GUCCUCUGGAUGGCCGACGUUUCCACAGGGUGGAACUAUGACAACUUCUCCGCUG
CCAUCUGGAAUCCCAUAGUGGUAGCUGGGCCAAACGUCCAUGGGACUGAACAGGG
CAUUCCUCUCACCCGGGGAACCCUCAACUGGCCCGGGGGCGAUAGGAAUCGCUGG
CCCUACCGCAACCAGAUUGAGAAGGGUCACUGGUAUGUGACCUUCUGGACUCAGU
ACGAUCCUGAUGAGUGGGUCUGGUUGGAUGAGUUCCAUCUCCAGUUCACCUUGC
AACCGGGCACGCACACCCCCACUGAAAACCAUUACUGGGAUGUAACAGCAGACAG
CUUAGGUACUGGCCUCUGGGGCCUCCGGGACCUUGUGUUCUACCCAAUAGGUACC
CAGCCCAGGAUAGUGAUACCAAACACUGGGCCUACCAGCUCCCAUGUGACCUUCG
ACCUCCCCCCGGGUGAGGGCGAAGAUUACUCUACAGAUGAGGAAGGCGAGUCCGA
UGAGGGAGCUGAGGAUGAUGAAGGAAAUCCCCUUGAAUUUGACCACCCAUUAGA
CGGCGAUCUCUCGCAACCCCCCGCCGCCGUCCUGAAAGAUCUGACCUACAAGGGG
CGUAAUCUCGCCAAUGAAUUGUGGAGUACGGGGGUGCCAGAUGCGAAGGCCUGG
CUGGCGGGACAGACCAUCGACCCGUCGCCAUCCUUUCGCCGCUGGCGAGAGACUU
UUCAAAAAGCGCUCCAGCGUGGUGUAGCACCCCUGGAAGCGCAUGAGCUCGCUAC
UAGCGAGUUCCUUGCUCAAAGAGAAAGCCGCGGCCACGCCGAGUAGGAUCGAGGG
UACAGCUUUCUCCCCUGCUUUUCUGCUUCUUUCUGUGCUUUGGUGUUACUUUAGG
GUGAUAUAAUUGGCAUAAAAAUUGGCAAAAAAAAAAAAAAAAAAAAA
>Mouse_Astrovirus_STL_CY2_20120531_Update
(SEQ ID NO: 2)
CCAAGAAAGAGGCACUAGUGGCACUCCUGCUGCUAGUAAGUCUGACAUGGCCCUG
CGUAAGGAGUAUACUUCCCUUGUGGACCAAGCGUUCGACGCCGGGAACUAUCUGG
CCCGCUGCCAGUUGCCAACUACGGCAAUUCUGCUGUUGCGCAACAUGCCCGACCA
CCACUCCAAUCGGCCCUGGUCUGUCCAUUCAACUCCCCGCCACUUGGUCUAUCCC
UCAACAACGGACGACCCAAGGAUGCGGGUUAUAACAGCCUCCUCCGUAACAGUGG
AGGAUGAAUGGGUGACCUAUGCCUGGACCGGUGCGCGCUGGCAGCAGGUGGCAA
CGGCCCCUGAUUGCGGGAAGACGAUCCUGGUCUGCGCCCUCCUGAACGAACAUAA
GCGGCUCAAGGAUGAGAAUGCAAGCCUCAAACUUGCCAAGGCGAACUUGGAGGU
UGAUAACACCACACUACGGGUGGCGUCGGCGGCCAUCACCAACCCGGCCCCUCGC
CGCUCGCGCCUCCCCUGGAUCCUGGCACUCUUGGCUGUCUUCUUCUCCCUCCUCA
CGACCUCGGCUGCCUUUGAAACCAGCUCUACCUCGCGGAGUUAUGCCCCUGAGGA
UAUUGCUAGGCACUCUGAGGACUUGAACACCUUUAUUGAGAACGCUUUGAGGGU
AAACCAUACACGCUCCUACACGGAGUACACCUACCAACUGUAUUCCACACAUGCU
CAGACUUUCUUAGAUCGCAUGGCCUUGACAUUCAACACCUGGCAAGCCUAUGAUC
CGCACUUCUUUGUGAAAACACCUCUGCAAAGUGCGCUUCUGAGUGUCCUCCAGUA
UGUAACACCCUGGACGUGGGAGAUAGCCCUUACGGGCUUGGUGCUGGCGCUCAUG
CUAGCAGAGAAUACUAGCCCUUGGGCGCUGCUCUACCUAGCCUGCGCUACUCUCA
CAAGGACCCGCUUUGCCCUCUUGGCCGUGGCGCCCUUCCAGACACGCUACACGAC
GGCUGUAACUAUUGCCGUCUCGGUGCUCUACGCACUCGACCCCUUGGUCGCUGUG
GCGUGCCUGGUGCUACACCUCUUUCUCUUGGCAGUGGUGGGGCUCUUCAUGGAGG
ACACCUCCUAUGUCCAAAACUUGAAGGGCGCCUUUCUGCUGCUAUGCGCCUUCUU
UGGCCACGCCCUCUGCGCCCUCUUCGGAGUGAGCUCGGCGCCAGUCACGACACUG
GCUGUCGUCUGGCGAAUCUGGCGGCUACUCUCUCGUGCCGGAACAACAGGCACUG
UGGAGGUGCGCAAUGAAGAAGGCAAGGUGGUCUCAAAACAGACCACACAACCCA
ACUUCCUCUUCCGCUUCAAGCAGGCGUUGAGGAGGAUGAGACAACUUAGAACGAC
CCAGACCCCCCUGGCACGCGUCAAUCCUGAUGCGCUCUGCCACGUCAGCGUAACC
GGGGCGAAGGGCACUGGCUUCUUCUGUGGUAACUAUGCUGUGACAUGCGCACAC
GUAGUUGGGAGUGAGACAGUUGUCAACCUGUGCUAUAAAGGCCAUAACUACCAG
GCCCCAGUGAAGAAAAUCCUGGCGCAUAAGGAUGUGGCACUCAUUUCCAUACCAA
CGGGGCUAACACCACCCCGCUUGAAGAUCUCUAGGAAGCACUGCUGCGACUGGGU
CUGCGUUUGUGCCCCCGACGGUGAUGGCGCCUACCUAACCGCUGUAACUGAGGGU
UGCGAGCAUGAUGGUCACUACUCCUACGUCUGCCCGACGCGGGAUGGGAUGUCUG
GUGCUCCUCUGCUAGACAUAGAUGGCCAUGUCCUUGGGAUACAUACCAACAAUAC
UGGCUAUACUGGUGGUGCCCAACGCCUCGACCUUGAUGAUAUAGUUGAGCCCCCC
AAGCCAAGUCCCAGGCAGCUCGCCCUCGAGGCGGAGGUUGAAAACCUGAGAAAAC
AGCUCGAAAGUCUGCGGUCUGAACCCUUUAGGCCUGAGUCCGUGGCUGCCCUCUC
UUCAACCGUGCAGCCCGGCCCCCUAGUGGUUCCAACUACCUGCCCUCCUCCAGCCC
CACCGGCACCAACUGUGGUCCCUGUUCCCGUGGCCCCUAGCCCUGUGGUUAAACC
CACCCAAACUCCACCUAUGCAACAAAGCUUGACAACUAGUGAUGUGGUGGAUCUU
GUGCGCGCGGCAAUGGGUCGUGAGAUGCAAAUCCUGCGGGACGAGUUGAACCUG
AUGAAUCAGGCUAAAGGGAAGACUAAGCGUGGCCGUGGGAAGAAGCACACUAUC
GGGGCUCGUGUUGGUGGCCGCCGCAAACAGCGUGGGCCUGCCUUCACUGAAGAGG
AGUAUAAGGAGAUGCUGGACCAAGGGAUUGAUCCCGAUGAGAUCAAGCGUCUAG
CUGAAGACCUCUGGGAGGACCAGACUGGUUUCCCAGAGUGGAGUGAUCCUGAGU
UCUCUGAUGAGGACGAUGGCUGGACACCAAAAACUCAUGAUUGGCUAGACUUUG
AUUAUGAGGAUGACUUGGAACAAACCCAUGUCCCUGGUCCCUGGGCCCAGAAAUG
CAAGAUACCUCUCGUCGACUAUGUCAAGAAGAUCUUUGACAGAGGCUCUGUUGA
UGAGAUGUUACAAAAUCUUGCCCCCCUGGAGAAGAAGCUCUGUAGGAAACAGCU
CGAGGCCGUCCGCCAGGCAAACACUGAUAUCGAGCUUUCCGUUGCACUUGGCGCC
UUGGAUCGUCGUGCUGCCGAUGUCGGCAUGCAGCCCUUUACACCAGGCCUAGAGU
ACAAACAGGCUGUUCCAAAAAACGCCAAGGGCCCCCGCAAGGGGGCAAAAGAUCA
GGGCUCGAAGACUGGAAAGAACUGAGGCAGCCCCCCUUUCGCCUCCUGGUACCCC
AGCCUUACCCUGUUGUCUGCAGCUUACCCCUGGACCGGCCCAUCUAUGACAACGA
UGAGCCCAAAGAUCCGCUUCUGGGGGUGUUGCCACAUGUGGACUACGAGGGUAA
UUUUGCACCAACAACCUGGGGAGGCGCAGCCUACGCGAAGAGUUUCGAGAAGUUC
ACAUACGCUCAACCUGUGGACUUCGAAAAGCACUAUCCUGUAGAAACUCAGUUCG
CUGACUGGGCCUGGCGAGUCCAUCACGCCUAUCUGGAAGGCACUCGGGUCUGUCA
CAUCAUGUCUACAGAGAAAAAUACCGACUCGACCCCCGCCUACCCCAAAUGCCUG
GACUACUCCACCGAGGCCGACUACCUGGAGGAACAUGGCUGGGAGCCCUAUGUCA
ACGCCUUCCGUGCCAUCGAUUCCGGGGAGCGGCCCCAGGUUCUCUGGUUCCUCUU
CUUGAAGAAGGAGAUUCUCAAACAAGAGAAGAUUCGCGACUCAGACAUUCGUCA
GAUUGUCUGCUCAGAUCCCAUCUAUGCGCGGAUCGGAGCUUGCUUCGAACAACAU
CAAAAUCAUCUCAUGAAGCAAAAAACAGAGACCCACUCCGGGCAAUGUGGGUGG
UGCCCCCUGAAGGGGGGCUUUGAGGCAAUGUGCCAUCGUCUUGCCUCUAAGCAGG
GUGUCUUUGUGGAAUUUGACUGGACACGCUUUGAUGGAACAAUCCCUGUACAAC
UCUUCCGCAGGAUAAAGAAGCUUCGCUGGUCCAUGGUUUGCCCCGAACAUCAGCA
GCGCUACGGGCACAUGUACCGGUGGUAUGUUAACAACCUCCUGCACCGCUACACC
GUGCUGCCCUCAGGCGAGGUGACCAUCCAAACUCGUGGCAACCCCUCAGGGCAAA
UCUCAACAACAAUGGAUAAUAAUAUGGUUAACUACUGGCUUCAGGCAUUUGAGU
UCUGCUACUUCUUUGGCCCCAAUAAGGAUCUCUGGCGGCAGUAUGAUACUGUCUG
CUAUGGUGAUGACCGGCUCACGCGCUACCCUGUGCUACCGCCCCACUACAUCGAG
CGGGUGGUCGCCAUGUAUAAGGACAUCUUUGGCAUGUGGGUUAAACCUGAAAAG
GUGCGCGUUAGUGACACUCUGGUUGGUCUCACCUUCUGUGGCUUUAGAAUAGGG
GAGCACUAUUUGCCUUAUCCUGCACAGGAAGAUAAACUCUUUGCCGGCCUCGUCC
GGCCAGUGAGGAAAUUGGCUGACUUCAAAACACUCCAUGGGAAACUCUUGAGCC
UGCAGCUUCUGAUGCACUUUCAUCCUCCGAGUCCCUUCAAGGACUACUUGGAGAU
GUGCCUGGCAAACACCGCCAAGUACUGCCCGGAACUUCCGGCGCGGUUUUCAGAG
CGUCAGAUGGACAAGCUUUGGAGGGGAGGACCAAAAGCUGUUCAUGGCUAAGGC
CAAACAACCACAGAAAAAUGCCACGACCGUCACUACUACAACUGUCUCUGGUGGC
AGUAGUCGGCGGUCUCGCAGGCGCUCUGUACGGCGCCGCGCUACAGGCUCUUCUA
ACCCCCCAACAAAGACAACAACUGUUCGGACUGUUUUUCGCCGCAAUACCCGGCC
UCGCGGUAAUCGCCGCAGGAGUAGGAAUGCUCAGCGGCAGGCUCCUCGCGAGGUU
GUCCAGACGGUUACGGCGACCCUCGGAACGGUUGGCGCGAACCAGGGCGAUCAGG
UCGAGCUUGAGAUGGCAGCGCUCCUCAGCCCAGCGCUGAUUAAGGAAACAACUGG
UUCAAACGCCUUUGGGCCACUCCAGAUGUAUGCCUCACGCAUGCCAUGUGGAGA
GUGGACAGGCUCACACUCAGGCUCACCCCCCUGGUCGGCGCCUCUGCCGUUUCCG
GCACAGCAGUCCGUGCCUCACUGAACAUGACAUCUGGGCCCGCUGCGCCCGCCUG
GUCAGCCUUGGGCGCGCGGAAGCAUGUGGAUACCAACCCUGGUCGGCCGGCUUCC
UUCACCCUUACAGCCGCCGAUGUACCUGGCCCCAAGCAGGGCUGGUUCCUUACUA
ACACUAAGCAGGAUGCCGGCUUUUCAGUCGGCGGGGCCAUUGAGAUACACACCCU
CGGCAAGACGAUGUCAACUUAUCAGAAUAAAGCCUAUGAUGGCCCACUUUUUCU
UGCCGAGGUCACGGGCACCUGGAGGUUUAAGAACUAUGAGCCCCAGCCCGGCAUG
CUCAACCUCCUCAAGACCGAGGUCAAGGAGCCCGCGGGUACUGUGAAGAUCCACU
CCAAGCCUGGAGAACCUGUCACGCUCUCCAUCCCUGAAGCAGGGACCUUUGCUGG
CCUAGAGAGGCUAAAUCCAACAGCCUCGGCCACGCCAGGUGAGAUCAUCUGGGAG
GUAGUGGAUUCCGCCGCGAAGGCGGUUUCCGGCUUGCUUCCUCAACCCUGGCAGU
GGCUCUUUAAAGGCGGCUGGUUUUUCCUGAAAAGAAUUGCCAACCGGAAACCUG
UUGGCGCUGCCAGUGUGGCGGGUGAACCUGAUGGAGGUGAGGUGACCUUCCGCG
UAUACGCUAGUAUCGCGGAUGCCCAGAAUGAUGUACCCUGUAUCGCCAGCUCGGC
GGCCUCUACUCAAUCCAUACAGACGGAGGGGCUCAAGAUUUCCCAGGUGACUCCU
GGGACCAUUGGCAUGCCUGAAACUGCAAUUGCCACACAUAAUAUGGUCCCACCAC
CCGAGUCCGGACCCUACUACUAUCAGGGGCCCACCUGGAGGCUGCUAUUCCCUU
GCGCGGCCCCAAGUAUACACAGUGGAUUCUUGUGGAUGCCGGACGCUCCCAGGAA
UCGGCCCGCCUCCAUUCCGGGGUGGUCCCGGCAGAGCAGACCUCGGCCUGGUCGA
GCUGUACCUUGGAACUCCCAGGCACUUUCCUCCAGAAUAUGCAUGAGAUUGAUCC
CCGUGAUGUUGCAGCCGGUACCUUUCCCAUCAACUACUGGAAUGCGAGCACCUCG
ACGCUCACGCGGCUCGGUACCGCCUACGGUUGCAAUCAAGCGCGGGCACGCACCU
AUGGGGAGGGAGUCCCGCAUGUGGUCAUCUCCACCACCUCUGUCCUCUGGAGGGC
CGAUGUCUCCGAAGGGUGGAACUAUGACAACUUUGUAGCUGCCAUCUGGAAUCC
UAUUGUGGAGGCUGGGCCUAAUGUCCAUGGAACCGAACAGGGCAUGCCUCUUACC
CGUGGCACUCUCAACUGGCCCGGAGGCGAUAGGAAUCGCUGGCCCUACCGCAACC
AGAUUGAGGAGGGUCGCUGGUACGUGACCUUCUGGACUCAGUACGAUCCUGAUG
AGUGGGUCUGGUUGGAUGAGUUCCAUCUUCAGUUCACCUUGCAGCCGGGCACGCA
UGCCCCUACCGAUAACCAUCACUGGGAUAUAACAACAGAUAGUCUAGGUACUGGC
CUCUGGGGCCUCCGGGAUCUUGUGUUCUACCCAAUAGGUGUUCAGCCCAGGAUAG
UGAUACCCCCCACUGGGCCUACCAGCUCCCGUGUGACCUUCGACCUCCCCUCGGG
UGAGGACGAUGAGUACUACACAGAUGAGGAAGGCGAGUCCGAUGAGGGAGCUGA
GGAUGAUGAAGGACCCCCCCUUGAAUUUGACCACCCAUUAGACGGCGAUCUCUCG
CAACCCCCCGCCGCCGUCUUGAAAGAUCUGACCUACAAGGGGCGCAAUCUCGCCA
AUGAGUUGUGGAGUACGGGGGUGCCAGAUGCGAAGGCCUGGCUGGCGGGACAGA
CCGUUGACCCGUCGCCAUCCUUUCGCCGCUGGCGGGAGACUUUUCAAAAAGCGCU
CCAGCGUGGUGUGAAACCCCUGGAAGCGCGUGAGCUCGCUACUAGCGAGUUCCUU
GCUCAAAGAGAAAGCCGCGGCCACGCCGAGUAGGAUCGAGGGUACAGCUUUCUCC
CCUUGCUUUUCUGCUUCUUUCUGUGCUUUGGUGUUACUUUAGGGUGAUAUAAUU
GGCAUAAAAAUUGGCAAAAAAAAAAAAAAAAAAAAA
>Mouse_Astrovirus_STL_CY3_20120618_Partial
(SEQ ID NO: 3)
CUUUGGAGGGGUGGACCAAAAGCUGUUCAUGGCUAAGGCCAAACAACAACAGAA
AAAUGCUACGACCGUCACCACUACAACUGUUUCUGGUGGCAGUGGUCGGCGGUCU
CGCAGGCGCGCUGUACGGCGCCGCGCUGCAGGCUCUUCUAACCCCUCAACAAAGA
CAACAACUGUUCGGACUGUUUUUCGCCGCAAUACCCGGCCUCGCGGUAAUCGCCG
CAGGAGUAGGAAUGCUCAGCGGCAGACUCCUCGCGAGGUUGUCCAGACGGUUACG
GCGACCCUCGGAACGGUGGCGCGAACCAGGGCGAUCAGGUCGAGCUUGAGAUGG
CAGCGCUCCUCAGCCCAGCGCUGAUCAAGGAAACAACUGGCUCAAAUGCAUUUGG
UCCACUACAGAUGUAUGCCUCCACGCAUGCCAUGUGGAGGGUGGAUAGGCUCACA
CUCAAGCUCACCCCCUUGGUCGGCGCCUCCGCCGUCUCCGGUACAGCAGUUCGUG
CCUCACUGAAUAUGACAUCAGGACCCGCUGCGCCCGCCUGGUCAGCUCUGGGCGC
GCGGAAGCACGUGGAUACCAACCCUGGUCGGUCGGCCUCCUUCACCCUCACAGCC
GCCGACAUCCCUGGCCCUAAGCAAGGUUGGUUCCUCACUAACACCAAGCAAGACG
CCGGCUUCUCAGUCGGCGGGGCCAUUGAGAUCCAUACUCUCGGCAAGACAAUGUC
AACCUACCAGAAUGCGCCCUACACCGGCCCACUCUUUCUUGCCGAGGUCACAGGC
ACCUGGAGGUUUAAGAACUAUGAGCCCCAGCCUGGCAUGCUUAACCUCCUCAAGA
CCGAGGUUAAAGAGCCUGCGGGCACUGUGAAAGUACACUCAAAGCCCGGGGAGCC
UGUCACACUCUCUAUUCCUGAAGCAGGGACCUUUGCCGGCCUUGAGAGGCUAAAU
CCAACAGCUUCGGCCACGCCGGGUGAGAUCAUCUGGGAGGUGGUGGACUCCGCCG
CGAAUGCGGUCUCCGGACUACUCCCUCAACCCUGGCAGUGGCUCUUUAAAGGCGG
CUGGUUCUUCCUGAAAAGGAUUGCCAACCGGAAACCGGUUGGUGCUGCUACUGU
GGCGGGUGAACCUGAUGGAGGUGAAGUUACCUUCCGCGUCUAUGCCAGCAUCGCG
GAUGCCCAGAAUGAUGUUCCUUGCAUUGCUUCCUCGCAGGCCUCUACUCAAUCCA
UACAGACGCAGGGGCUUAAGAUCUCUCAAGUGACUCCUGGGACCAUUGGCAUGCC
CGAAACCGCGAUUGCCACCCAUAAUAUGGUCCCACCACCUGAGUCUGGACCCUAC
UACUAUCAGGGGCCCACCCUGGAGGCUGCUGCUCCCCUGAAAGCCCCCAAAUACA
CACAGUGGAUACUUGUGGACGCUGGGGCUUCCCAGGAGGGGCCUCGCCUACACUC
CGGGUGGUUCCAGCAGAGCAGACCUCAGCCUGGUCGAGCUGCACCUUGGAGCUC
CCAGGCACCUUCCUCCAGAACAUGCAUGAGAUUGACCCCCGUGACGUUGCAGCCG
GUACCUUUCCCAUCAAUCACUGGAAUGCGAACACUUCGGUGCUCACGCGGCUUGG
CACCGCCUACGGUUGCAACCAAGCGCGGGUUCGCACCUCCGGGGAAGUCACGCUG
GUUAUCUCCACCACUUCUGUUCUCUGGAGGGCCGAUGUCUCCAUAGGGUGGAACU
AUGACAACUUCCUAGCUGCCAUCUGGUGCCCCAUUGUGGUGGCUGGGCCUGGUGU
CCAUGGAACUGAACAGGGCAUGCCUCUUACCCGGGGCACUCUCAACUGGCCCGGG
GGCGAUAGGAAUCGCUGGCCCUACCGUAACCAGAUUGAGGAGGGUCACUGGUAU
GUGACCUUCUGGACUCAGUACGAUCCUGAUGAGUGGGUCUGGUUGGACGACUUC
CACCUCCAGUUCACCUUGCAACCGGGCACGCAUACCCCCACUGAUAACCACCGCU
GGGAUAUAACAACAGAUAGCUUGGGCACUGGCCUCUGGGGCCUCCGGGACCUUGU
GUUCUACCCAAUAGGUGUUCAGCCCAGGAUAGUGAUACCACCCACUGGGCCUACC
AGCUCCCGUGUGGUCUUCGACCUCCCCUCGGGUGAGGACGAUGAGUACUACACAG
AUGAGGAAGGCGAGUCCGAUGAGGGAGCUGAGGAUGAUGAAGGAAACCCCCUUG
AUUUUGACCACCCAUUAGACGGCGAUCUCUCGCAACCCCCCGCCGCCGUCUUGAA
AGAUCUGACUUAUAAGGGGCGUAAUCUCGCCAAUGAGUUGUGGAGUACGGGGGU
GCCAGAUGCGAAGGCCUGGUUGGCGGGACAAGCCGUUGACCCGUCGCCAUCCUUU
CGCCGCUGGCGGGAGACCUAUCAAAAAGCGCUCCAGCGUGGUUUGAAACCCCUGG
AAGCGCGUGAGCUCGCUACUAGCGAGUUCCUUGCUCAAAGAGAAAGCCGCGGCCA
CGCCGAGUAGGAUCGAGGGUACAGCUUUCUCCCCUGCUUUUCUGCUUCUUUCUGU
GCUUCUGGUGUUACUUUAGGGUGAUAUAAUUGGCAUAAAAAUUGGCAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
>Mouse_Astrovirus_STL_CY4_20120618_Partial
(SEQ ID NO: 4)
CUUUGGAGGGGUGGACCAAAAGCUGUUCAUGGCUAAGGCCAAACAACAACAGAA
AAAUGCCACGACCGUCACCACUACAACUGUUUCUGGUGGCAGUGGUCGGCGGUCU
CGCAGGCGCGCUGUACGGCGCCGCGCUGCAGGCUCUUCUAACCCCUCAACAAAGA
CAACAACUGUUCGGACUGUUUUUCGCCGCAAUACCCGGCCUCGCGGUAAUCGCCG
CAGGAGUAGGAAUGCUCAGCGGCAGACUCCUCGCGAGGUUGUCCAGACGGUUACG
GCGACCCUCGGAACGGUUGGCGCGAACCAGGGCGAUCAGGUCGAGCUUGAGAUGG
CAGCGCUCCUCAGCCCAGCGCUGAUCAAGGAAACAACUGGCUCAAAUGCUUUUGG
UCCACUACAGAUGUAUGCCUCCACGCAUGCCAUGUGGAGGGUGGAUAGGCUCACA
CUCAAGCUCACCCCCUUGGUCGGCGCCUCCGCCGUCUCCGGCACAGCAGUUCGUG
CCUCACUGAAUAUGACAUCAGGACCCGCUGCGCCCGCCUGGUCAGCUCUGGGCGC
GCGGAAGCACGUGGAUACCAACCCUGGUCGGUCGGCCUCUUUCACCCUCACAGCC
GCCGACAUCCCUGGCCCUAAGCAAGGUUGGUUCCUCACUAACACCAAGCAAGACG
CCGGCUUCUCAGUCGGCGGGGCCAUUGAGAUUCAUACUCUCGGCAAGACAAUGUC
AACCUACCAGAAUGCGCCCUAUACCGGCCCACUCUUUCUUGCCGAGGUCACAGGU
ACCUGGAGGUUUAAGAACUAUGAGCCCCAGCCUGGCAUGCUUAACCUCCUCAAGA
CCGAGGUUAAAGAGCCUGCGGGCACUGUGAAAGUACAUUCAAAGCCCGGGGAGCC
UGUCACACUUUCUAUUCCUGAAGCAGGGACCUUUGCCGGCCUUGAGAGGCUAAAU
CCAACAGCCUCGGCCACGCCGGGUGAGAUCAUCUGGGAGGUGGUGGACUCCGCCG
CGAAUGCGGUCUCCGGACUACUCCCUCAACCCUGGCAGUGGCUCUUUAAAGGCGG
CUGGUUCUUCCUGAAAAGGAUUGCCAACCGGAAACCGGUUGGUGCUGCUACUGU
GGCGGGUGAACCUGAUGGAGGUGAAGUUACCUUCCGCGUCUAUGCCAGCAUCGCG
GAUGCCCAGAAUGAUGUUCCUUGCAUUGCCUCCUCGCAGGCCUCUACUCAAUCCA
UACAGACGCAGGGGCUUAAGAUCUCUCAAGUGACUCCUGGGACCAUUGGCAUGCC
CGAAACCGCGAUUGCCACCCAUAAUAUGGUCCCACCACCUGAGUCUGGACCCUAU
UACUAUCAGGGGCCCACCCUGGAGGCUGCUGCUCCCCUGAAAGCCCCCAAAUACA
CACAGUGGAUACUUGUGGACGCUGGGACUUCCCAGGAGGGGCCUCGCUUACACUC
CGGGGUGGUUCCAGCAGGGCAGACCUCAGCCUGGUCGAGCUGCACCUUGGAGCUC
CCAGGCACCUUUCUUCAGAACAUGCAUGAGAUUGAUCCCCGUGAUGUUGCAGCUG
GCACUUUUCCCAUCAACCACUGGAACGUGCGCACCUCGACGCUUACGCGGCUUGG
CAUCGCCUAUGGCUGUAAUCAGGCGCGGGUCCGCACCUAUGGGGAAGGGGUCCCG
CAUGUGGUCAUUUCCACCACCUCUGUGCUCUGGAGGGCCGAUGUCUCCGAAGGCU
GGAACUAUGACAACUUUCUUGCUGCCAUCUGGAAUCCCAUUGUGGAGGCUGGGCC
CUCCACCCAUGGAACUGAACAGGGUGUGCCUCUUACCCGGGGCACUCUCAACUGG
CCCGGGGGUGAUAGAAAUCGCUGGCCCUACCGCAACCAGGUUGAGGAAGGUCACU
GGUACGUGACCUUCUGGACUCAGUACGAUCCUGAUGAGUGGGUCUGGUUGGAUG
AGUUCAAUCUCCAGUUCACCUUGCAGCCCGGCAACCACACCCCUACUGCUAACCA
CCACUGGGAUAUAACAACAGAUAGCUUAGGCACUGGCCUCUGGGGCCUCCGGGAC
CUUGUGUUCUAUCCAAUAGGUGUCCAGCCCAGGAUAGUGAUACCGCCUACUGGGC
CUACUAGCUCCCGUGUGACCUUCGACCUCCCCUCGGGUGAGGACGAUGAGUAUUA
CACAGAUGAGGAAGGCGAGUCCGAUGAGGGAGCUCAGGAUGAUGAAGGGAAUCC
CCUUGAAUUUGACCAUCCAUUAGACGGCGAUCUCUCGCAACCCCCCGCCGCCGUC
CUGAAAGAUCUAACCUACAAGGGGCAAAAUCUCGCCAAUGAGUUGUGGAGUACG
GGGGUGCCAGAUGCGAAGGCCUGGCUGGCGGGGCAGACUGUUGACCCGUCGCCAU
CCUUUCGCCGCUGGCGGGAGACCUUUCAAAAAGCGCUCCAGCGUGGUGGUAAAGCC
CCUGGAAGCGCGAGAACUCGCCACCAGCGAGUUCCUUGCUCAAAGAGAAAGCCGC
GGCCACGCCGAGUAGGAUCGAGGGUACAGCUUUCUCUCCCCGCUUUUCUGCUCCU
UUUCUGUGCUUUUGGUGUUACUUUAGGGUGAUAUAAUUGGCAUAAAAAUUGGCA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
[0070] Oligonucleotides of the present teachings, which include but are not limited to oligonucleotides which can serve as probes and/or primers for detecting a murine astrovirus, include the following non-limiting examples:
[0000]
(SEQ ID NO: 5)
CUUUGGAGGGGAGGACCAAAAGCUCUUCAUGGGC;
(SEQ ID NO: 6)
CCAAGAAAGAGGCACTAGTGGCACTC;
(SEQ ID NO: 7)
GTTTTTTTTTTTTTTTTTTTTTGCCAATTTTTATGCCAATTATATCACC
C;
(SEQ ID NO: 8)
TACATCGAGCGGGTGGTCGC;
(SEQ ID NO: 9)
GTGTCACTAACGCGCACCTTTTCA;
and
(SEQ ID NO: 10)
TTTGGCATGTGGGTTAA.
[0071] In various aspects, an oligonucleotide can be RNA, DNA or a synthetic analogue such as a peptide nucleic acid. In various aspects, an oligonucleotide of the present teachings can further comprise one or more labels, such as a fluorophore, a fluorescence quencher, a hapten such as biotin, or a radioisotope such as 33 H, 14 C, 32 P, 33 P, 35 S, or 125 I.
[0072] Oligopeptides of the present teachings, which include but are not limited to peptides that can serve as antigens for a vaccine, an antibody or a serum conversion assay, or a competitive probe for an antibody-based assay such as a radioimmunoassay include, without limitation,
[0000]
(SEQ ID NO: 11)
CGGDRNRWPYRNQIE
and
(SEQ ID NO: 12)
CSEFLAQRESRGHAE.
EXAMPLES
[0073] The present teachings including descriptions provided in the Examples that are not intended to limit the scope of any claim or aspect. Unless specifically presented in the past tense, an example can be a prophetic or an actual example. The following non-limiting examples are provided to further illustrate the present teachings. Those of skill in the art, in light of the present disclosure, will appreciate that many changes can be made in the specific embodiments that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the present teachings.
Example 1
[0074] This example demonstrates the detection of astroviruses using next generation sequencing.
[0075] In these experiments, to examine the mouse virome in an unbiased manner, fecal RNA and DNA libraries from three immunocompetent C57BL/6 (B6) mice were generated. The fecal RNA and DNA libraries were sequenced using 454 (pyrosequencing) technology (Roche) and VirusHunter was used to analyze the resulting reads. 100 mg of frozen stool was chipped and then resuspended in 6 volumes of PBS (Finkbeiner, S. R., et al., PLoS. Pathog. 4: e1000011, 2008). The sample was centrifuged to pellet particulate matter and the supernatant was then passed through a 0.45 μm filter. Total nucleic acid was isolated from 200 μL primary stool filtrate using AMPLIPREP DNA extraction machine (Roche) according to manufacturer's instructions. To enable subsequent detection of both RNA and DNA viruses, total nucleic acid from each sample was reverse transcribed and amplified as previously described (Wang, D., et al., PLoS Biol. 1: E2, 2003). Briefly, RNA templates were reverse transcribed using primerA containing a 16-nucleotide specific sequence followed by 9 random nucleotides for random priming. The 16-nucleotide specific sequence is unique for each sample and served as a barcode in assigning sequencing reads to a sample. SEQUENASE (United States Biochemical) was used for second strand cDNA synthesis and for random-primed amplification of DNA templates using PrimerA. Each sample was then subjected to 40 cycles of PCR amplification using PrimerB containing the same 16 nucleotide specific sequence as in the corresponding PrimerA. Amplification products were pooled, adaptor-ligated and sequenced at the Washington University Genome Sequencing Center on the 454 GS-FLX platform (454 Life Sciences).
[0076] Sequences were analyzed using customized pipeline VirusHunter as described (Zhao, G., et al., J. Virol. 85: 10230-8, 2011). Briefly, sequence reads were assigned to samples based on the unique barcode sequences (i.e. PrimerB sequences). For further analysis, primer sequences were trimmed off and the sequence reads were clustered using CD-HIT (Li, W., and Godzik, A., Bioinform. 22: 1658-9, 2006) to identify redundant reads. Sequences were clustered on the basis of 95% identity over 95% sequence length, and the longest sequence from each cluster was picked as the representative sequence. Then, unique sequences were masked by REPEATMASKER (http://www.repeatmasker.org). If a sequence did not contain a stretch of at least 50 consecutive non-“N” nucleotides or if greater than 40% of the total length of the sequence is masked, it was removed from further analysis (i.e., “filtered”). Good quality sequences after filtering were sequentially compared against (i) the human genome using BLASTn; (ii) GenBank nt database using BLASTn; (iii) GenBank nr database using BLASTx (Altschul, S. F., et al., J. Mol. Biol. 215: 403-10, 1990); Minimal e-value cutoffs of 1e −10 and 1e −5 were applied for BLASTn and BLASTx, respectively. Sequences were phylotyped as human, mouse, fungal, bacterial, phage, viral, or other based on the identity of the top BLAST hit. Sequences without any significant hit to any of the databases were placed in the “unassigned” category. If a sequence aligns to both a virus and other kingdom (e.g. bacteria or fungi) with the same e value it is classified as “ambiguous”. All eukaryotic viral sequences were further classified into viral families based on the taxonomy ID of the best hit.
[0077] All viral sequences and unassigned sequences from each sample were assembled into contigs using NEWBLER (454 Life Sciences) with default parameters. Sample 31H_B6_CR6 and 31H_B6_untreated were sequenced twice. Both sequencing data from each sample were used to try to obtain the best assembly.
[0078] 132 astrovirus sequences were identified: 21, 76, and 35 from mouse A, B, and C, respectively. No other viral reads were identified. The viral and unassigned reads detected in the feces of mouse B were used to assemble a 6,748-nucleotide (nt) contig with 9-fold coverage. A BLASTn (Altschul, S. F., et al., J. Mol. Biol. 215: 403-10, 1990) search of the NCBI nt database identified this contig to be a highly divergent astrovirus with at most 60% amino acid identity to Human Astrovirus 6 isolate Katano ( FIG. 1 ). Reads detected in the feces of mouse C were used to assemble four contigs ranging from 288 to 3095 nt with 99.0-99.7% nt identity to the 6,748-nt contig from mouse B. Reads detected in the feces of mouse A were used to assemble three contigs ranging from 1024 to 2463 nt with 89.1-95.2% identity to mouse B contig00001 ( FIG. 1 ). These data show the presence of at least two unidentified astroviruses in a specific-pathogen free research facility.
Example 2
[0079] This example illustrates the generation and sequencing of full-length murine astrovirus genomes.
[0080] In these experiments, subsequent analysis of the fecal specimens from mouse B and mouse C utilizing rapid amplification of cDNA ends (RACE) reactions and traditional Sanger sequencing generated the complete consensus genomes of the two mouse astroviruses: MoAstV STL CY1 and MoAstV STL CY2 ( FIG. 2 ).
[0081] Total RNA was extracted from the murine stool samples previously used in the deep sequencing reaction using an RNEASY mini kit (Qiagen, Valencia, Calif.). One microgram of RNA was used as the template for Rapid Amplification of cDNA Ends (RACE) reactions to generate the 5′ and 3′ genome ends using 5′ RACE and 3′ RACE kits (Invitrogen, Carsbad, Calif.) according to the manufacturer's instructions. To generate full genomic sequences, one microgram of RNA was used as the template for cDNA synthesis using the SUPERSCRIPT III first-strand synthesis kit and an oligo(dT) 12-20 primer (Invitrogen) according to the manufacturer's instructions. Full genomic sequences were then amplified using ELONGASE Enzyme Mix (Invitrogen) and primers 5′-CCAAGAAAGAGGCACTAGTGGCACTC-3′ (SEQ ID NO:6) and 5′-GTITITITIITIITIITIIITGCCAATTITTATGCCAATTATATCACCC-3′ (SEQ ID NO:7). The 6.7 kb PCR product was gel purified and ligated into a pCR4-TOPO TA sequencing vector (Invitrogen). Universal M13 forward and reverse primers were used for sequencing, and primer walking was applied as needed. Four clones with 2 to 4-fold redundancy each were used to construct consensus sequence 1 using GENEIOUS Pro v5.0 (Biomatters Ltd.) (Bosma, M. J., and Carroll, A. M., Ann. Rev. Immun. 9: 323-50 m 1991). Three clones with 2 to 4-fold redundancy each were used to construct consensus sequence 2. Predicted ORFs were identified using GENEIOUS. Protein motifs were predicted using Pfam (Finn, R. D., et al., Nuc. Acid. Res. 38: D211-D222, 2010).
[0082] Comparison of the MoAstV STL CY1 genome to contig BI generated by 454 pyrosequencing showed 99.9% nt identity, demonstrating that they are the same virus. Comparison of the MoAstV STL CY2 genome to contigs A00001, A00002, and A00010 generated by 454 pyrosequencing showed 99.6-99.9% nt identity, demonstrating that they are the same virus.
Example 3
[0083] This example illustrates that the MoAstV STL genome organization is consistent with other mamastroviruses.
[0084] In these experiments, the complete genome length of MoAstV STL CY1 and MoAstV STL CY2 was 6,817 nt, excluding the poly-A tail. MoAstV STL CY1 and MoAstV STL CY2 were predicted to contain a 5′ untranslated region (UTR), three open reading frames (ORF 1a, 1b, and 2), a 3′ UTR, and a polyA tail . The 5′ and 3′ UTR were determined to be 46 and 90 nt in length, respectively.
[0085] ORF1a of MoAstV STL CY1 and MoAstV STL CY2 was predicted to encode a 928 as protein containing a trypsin-like peptidase domain and showed significant similarity to known astroviruses by BLASTP (Altschul, S. F., et al., J. Mol. Biol. 215: 403-10, 1990). The 58-nt ORF1a/1b junction of MoAstV STL CY1 and MoAstV STL CY2 contained the heptanucleotide frameshift signal (AAAAAAC) conserved in all astroviruses (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Jiang, B., et al., P. Natl. Acad. Sci. USA. 90: 10539-43, 1993; Lewis, T. L. and Matsui, S. M., Arch. Virol. 140:1127-35, 1995; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007). Furthermore FSFinder analysis (Moon, S., et al., Nucleic. Acids. Res. 32: 4884-92, 2004) confirmed that the downstream sequence was capable of generating a stem-loop structure required for a-1 ribosomal frameshift to lead to ORF lab translation (Brierley, I., et al., Biochem. Soc. T. 36: 684-9, 2008; Giedroc, D. P. and Comish, P. V., Virus Res. 139: 193-208, 2009; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007). The first amino acid in frame with the frameshift signal was predicted to be the start position for ORF1b of MoAstV STL CY1 and MoAstV STL CY2. ORF1b of MoAstV STL CY1 and MoAstV STL CY2 is predicted to encode a 502 as protein containing an RNA dependent RNA polymerase (RdRP) domain, consistent with other astroviruses (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011; Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007).
[0086] MoAstV STL contained a sequence upstream of ORF2—highly conserved among mammalian astroviruses—CUUUGGAGGGAGGACCAAAAGCUCUUCAUGGGC (SEQ ID NO: 5), which encompasses the ORF2 start codon (in bold) and is suggested to be a promoter for sgRNA synthesis (Mendez, E. and Arias, C. F., Fields Virology, 5 th ed. p. 981-99, 2007; Walter, J. E., et al., Arch. Virol. 146: 2357-67, 2001). As in most other mamastroviruses (De Benedictis, P., et al., Infect. Genet. Evol. 11: 1529-44, 2011), MoAstV STL had an 8-nt region of overlap at the end of ORF1b and beginning of ORF2, with ORF2 maintained in the same frame as ORF1a. ORF2 of MoAstV STL CY1 and MoAstV STL CY2 was predicted to encode an 819-aa protein containing the structural capsid protein.
[0087] Collectively, these data demonstrate that the genome organization of MoAstV STL CY1 and MoAstV STL CY2 is consistent with other members of the Astroviridae family, and the mamastrovirus genus in particular.
Example 4
[0088] This example illustrates that MoAstV STL viruses are members of a new mamastrovirus genogroup.
[0089] In these experiments, to evaluate the relationship between MoAstV STL CY1 and MoAstV STL CY2 and other known astroviruses, phylogenetic analysis was performed using aa sequences predicted to correspond to the capsid-containing ORF2. Analyses performed for ORF1a and 1b showed similar relationships. In all analyses, MoAstV STL clustered with the mamastrovirus genus and not the avastrovirus genus.
[0090] Sequences from astrovirus genomic segments encoding ORF1a, 1b, and 2 were translated. These sequences were aligned using ClustalX 2.0.12 (Larkin, M. A., et al., Bioimform. 23: 2947-8, 2007). Phylogenetic inference was performed with maximum parsimony using PAUP 4b10 and maximum likelihood using RAxML (Stamatakis, A., Bioinform. 22: 2688-90, 2006) and BLOSUM62 transition matrix methods with 1000 bootstrap replicates. The resulting phylogenetic trees were visualized using FIGTREE 1.3.1 (http://tree.bio.ed.ac.uk/software/figtree). MEGA 5.05 was used for distance estimation (uncorrected p-distance) (Tamura, K., et al., Mol. Biol. Evol. 28: 2731-9, 2011).
[0091] The MoAstV STL viruses were most closely related to a clade of recently characterized porcine and wild boar astroviruses, but shared only 33-36% amino acid identity in the capsid region and 63-67% amino acid identity in the RdRp region. This genetic grouping also included the recently deposited mouse astrovirus sequence derived from laboratory mice in Cincinnati, murine astrovirus strain TF18LM but was highly divergent from mouse astrovirus M-52/USA/2008, previously detected in wild mice (Phan, T. G., et al., PLoS Pathog. 7: e1002218, 2011).
[0092] In analyses of ORF2, the MoAstV STL viruses formed a distinct genetic cluster with a mean amino acid genetic distance (p-dist) of 0.762±0.010 and 0.789±0.010 to mamastrovirus genogroups I and II, respectively. Intra-group p-dists were 0.548±0.010, 0.629±0.011, and 0.641±0.009 for mamastrovirus genogroups I, II, and the MoAstV STL genetic cluster, respectively.
[0093] Collectively, these data demonstrate that MoAstV STL is a mammalian astrovirus and is likely a member of a new third genogroup of mamastroviruses.
Example 5
[0094] This example illustrates that adaptive immunity is required to control MoAstV replication.
[0095] In these experiments, since MoAstV STL CY1 and MoAstV STL CY2 were originally identified in the feces of asymptomatic B6 mice, whether MoAstV STL was present in the feces of other mice from the same specific-pathogen free research mouse colony was examined. First, astrovirus was detected in immunocompromised mice in the cleanest barrier facility by PCR ( FIG. 3 ). In FIG. 3 , B-cell deficient mice are labeled MuMT and RAG deficient mice are labeled B6 RAG. To quantify the number of MoAstV STL CY1 and MoAstV STL CY2 genome copies in tissues and feces, a Taqman-based quantitative reverse transcriptase PCR (qRT-PCR) assay was designed ( FIG. 4 a ), which targeted a 72-bp region of the RdRP conserved between MoAstV STL CY1 and MoAstV STL CY2.
[0096] Total RNA was extracted from individual stool pellets using an RNeasy mini kit (Qiagen) or from tissue samples using Trizol reagent (Invitrogen). One tenth of the total stool RNA or 1 μg of tissue RNA was reverse transcribed using ImpromII RT (Promega, Madison, Wis.) and random primers (Invitrogen) to yield cDNA. Triplicate qPCR reactions were performed using one tenth of the cDNA, primers specific to an 80 nt region of ORF1b (sense: 5′-TACATCGAGCCGCKTGGTCGC-3′ (SEQ ID NO: 8); antisense: 5′-GTGTCACTAACGCGCACCTTITCA-3′) (SEQ ID NO: 9), and a Taqman probe (Applied Biosystems, Foster City, Calif.) with the sequence 5′-TTGGCATGTGGGTTAA-3′ (SEQ ID NO:10) containing a 5′ 6-carboxyfluorescein (6FAM) dye label, 3′ nonfluorescence quencher (NFQ) and minor groove binder (MGB). The number of genome copies per sample was determined by comparison to a standard curve (generated by a 10-fold dilution of target-containing-plasmid in tRNA (Invitrogen)). For stool samples, the number of genome copies per sample was multiplied by 100 to account for dilution from total RNA originally extracted from the stool pellet and are reported as genome copies per stool pellet.
[0097] Across multiple experiments, the assay was able to repeatedly detect from 10 6 to 10 1 genome copies, and 1 genome copy was detected in 2 of 3 technical replicates consistent with Poissan distribution statistics, suggesting that this assay was both sensitive and robust.
[0098] Given that previous human studies have implicated the adaptive immune system as essential in the control of astrovirus pathogenesis (Wood, D. J., et al., J. Med. Virol. 24:435-44, 1988), the number of astrovirus genome copies were measured in the feces of mice deficient in B and T cells due to a mutation in Recombination Activating Gene 1 [RAG1, (Mombaerts, P., et al., Cell. 68: 869-77, 1992). While these mice exhibited no overt signs of illness, up to 10 9 astrovirus genome copies per fecal pellet were detected and notably, 21/21 RAG −/− mice screened were positive for astrovirus. These data suggest that adaptive immunity is essential for restricting MoAstV replication.
Example 6
[0099] This example illustrates that innate and adaptive immunity contributes to the control of MoAstV replication.
[0100] In these experiments, to assess the relative hierarchy of innate and adaptive immunity in restricting MoAstV replication, the timecourse of natural astrovirus infection in B6 and RAG1 −/− mice were examined, as well as mice deficient in STAT1 −/− (STAT1 −/− ). C57BL/6J, B6.RAG1 −/− , and STAT1 −/− mice were bred and housed in an enhanced barrier specific-pathogen-free facility at Washington University in St. Louis in compliance with federal and institutional guidelines (Cadwell, K., et al., Cell. 141: 1135-45, 2010). All studies were performed using age-matched female mice between eight and ten weeks of age. Three mice, one of each genotype, were cohoused on day 0, and fecal samples were collected every 2 days to follow astrovirus shedding. Mice were euthanized on day 14 and tissues were harvested for analysis.
[0101] As previous studies have shown that astrovirus infections can spread beyond the gastrointestinal tract (Blomström, A. L., et al., J. Clin. Microbiol. 48: 4392-6, 2010; Quan, P. L., et al., Emerg. Infect. Dis. 16: 918-25, 2010), the distribution of MoAstV was investigated in multiple tissues as well as feces. In order to address the potential presence of additional astrovirus strains that might not be detectable by the TAQMAN assay, B6, STAT1 −/− , and RAG1 −/− mice were cohoused for 14 days to ensure infection by the same viruses occurred.
[0102] High levels of MoAstV shedding in fecal samples were observed in RAG1 −/− mice at day 0 and at all timepoints tested ( FIG. 4 b ). In contrast, low levels of MoAstV were observed in the feces of both B6 and STAT1 −/− mice at day 0, prior to cohousing. Two days of cohousing, elevated levels of MoAstV genome copies were detected in feces from B6 and STAT1 −/− mice, with STAT1 −/− mice shedding significantly more MoAstV than B6 mice at day 2 (p<0.05). Overall, MoAstV shedding over the course of the experiment differed significantly by genotype (p<0.0001 for all combinations).
[0103] The tissue distribution of MoAstV STL was analyzed after 14 days of cohousing. High levels of genome copies in the GI tract of RAG1 −/− mice were detected ( FIG. 4 c ), consistent with the observation that RAG1 −/− mice shed up to 10 9 genome copies per stool pellet. The quantity of viral genome copies detected in the GI tract of B6 and STAT1 −/− mice were significantly lower than in the RAG1 −/− mice (p<0.001 for all GI tract tissues tested). While MoAstV RNA was detected in the liver and kidney of RAG1 −/− mice, it was not detected in the liver or kidney of B6 or STAT1 −/− . A limited number of genome copies in the spleen of STAT1 −/− mice were detected, twice as many as observed in the spleen of wild-type mice, though this comparison was not statistically significant. MoAstV STL was undetectable in the brain of any mouse tested, in contrast to previously identified enteric mouse pathogens in immunocompromised mice (Karst, S. M., et al., Science. 299: 1575-8, 2003).
[0104] These data demonstrate a role for both the innate and adaptive immune systems in the control of astrovirus infection and replication.
Example 7
[0105] This example illustrates that MoAstV is present in mice from commercial mouse colonies.
[0106] In these experiments, the presence of MoAstV in mice available from commercial vendors was assessed. Since extremely high levels of MoAstV STL in the feces of RAG1 −/− mice were previously observed, the present inventors decided to assess the presence of MoAstV STL in commercially available mice lacking B and T cells. RAG1 −/− mice (B6.129S7-Rag1 tm1Mom /J, cat #002216) were purchased from The Jackson Laboratory, RAG2 −/− mice (129S6/SvEvTac-Rag2 tm1Fwa , cat#RAG2-F) (Shinkai, Y., et al., Cell. 68: 855-67, 1992) from Taconic facility IBU25, and SCID mice (CB17/Icr-Prkdc scid /IcrCrl, cat#236) (Bosma, M. J., and Carroll, A. M., Ann. Rev. Immun. 9: 323-50 m 1991) from Charles River facility WO9—the three major mouse vendors in the United States. Mice were sacrificed immediately upon arrival and samples were collected for analysis.
[0107] Consistent with previous findings ( FIG. 4 ), extremely high levels of MoAstV STL were observed in fecal and tissue samples from RAG1 −/− and RAG2 −/− mice ( FIG. 5 ). MoAstV was undetectable in the feces or tissues of SCID mice. Overall, however, these data suggest that MoAstV STL is a common pathogen, likely present in many research mouse facilities in the United States.
Example 8
[0108] This example illustrates antibody responses during murine astrovirus infection.
[0109] In these experiments, B6 mice were inoculated with MuAstV or mock-inoculated. Serum antibody responses measured at 16 days. Differences in MuAstV-specific antibodies were observed between MuAstV- and mock-inoculated mice (p<0.02; Mann-Whitney test) ( FIG. 6 ).
[0110] The astrovirus capsid protein can assemble into virus-like particles (VLP) which share biological properties of virions. A baculovirus system was used to express the capsid protein of MuAstV strain STL 2. The ability of MuAstV VLP to detect serum antibodies specific to MuAstV by ELISA were validated using MuAstV VLP compared to MNV virions, as well as MuAstV and MNV-inoculated mice (data not shown). Using this assay, an elevation of virus-specific antibodies was observed in the serum of MuAstV-inoculated mice compared to mock-inoculated control mice ( FIG. 6 ). These data demonstrate that VLP derived from the sequence of the capsid protein of MuAstV STL2 can detect a serological response to MuAstV infection, which can be used for the establishment of MuAstV-free mice.
Example 9
[0111] This example illustrates the prevalence of murine astrovirus in a specific pathogen-free breeding facility.
[0112] Fecal pellets were obtained from mice from Dec. 4, 2011-Jan. 15, 2012 and the presence of murine astrovirus tested by quantitative RT-PCR. Limit of detection=100 genome copies/fecal pellet. Mice were housed 1-5 mice/cage, on 7 racks in 1 breeding room. Bedding sentinels were housed 2 mice/cage, 1 cage/rack in the same room.
[0113] MuAstV sequences were detected by next generation sequencing or quantitative PCR (qPCR) in the feces of mice from at least six research institutions and two commercial vendors. Furthermore, MuAstV was detected by qPCR in 73% of mouse lines in a single breeding room at Washington University School of Medicine (Table. 1). These results demonstrate that the prevalence of MuAstV in laboratory mice can be equal to or greater than that of murine norovirus (MNV), which is the most prevalent, recognized viral agent in laboratory mice today.
[0000]
TABLE 1
Mice
Sentinels
# of
# of
# of
# of
# of
# of
mice
cages
lines
racks
mice
cages
MuAstV positive
122
72
32
7
5
3
Total tested
485
178
44
7
14
7
Prevalence of MuAstV
25%
40%
73%
100%
36%
43%
Example 10
[0114] This example illustrates genetic diversity of murine astroviruses identified by next-generation sequencing.
[0115] Virus contigs from fecal samples (red) were aligned with known (black) MuAstV sequences using ClustalW. A maximum-likelihood phylogenetic tree was generated using MEGA.
[0116] Shotgun sequencing of libraries of RNA and DNA isolated from 35 fecal samples from laboratory rodents using the 454 GS FLX Titanium platform generated an average of 31,781 high quality reads per sample. The virome was examined using VirusHunter. Sequences with 76-99% nucleotide (nt) identity to MuAstV strain STL 1 were detected in mouse samples (example sequences illustrated in FIG. 7 ). These data demonstrate that MuAstV can be genetically diverse.
Example 11
[0117] This example illustrates kinetics of murine astrovirus shedding.
[0118] In these experiments, C57BL/6 (B6) and STAT1 −/− mice were inoculated with MuAstV and shedding in feces was measured. RAG1 −/− mice were naturally infected with MuAstV and shedding in feces measured for 14 days. Differences in MuAstV shedding were observed between B6 and STAT1 −/− mice at 6-12 days (p<0.05; one way ANOVA); significant differences in MuAstV shedding were observed between B6 and RAG1 −/− mice, STAT1 −/− and RAG1 −/− mice at all time points (p<0.05; one way ANOVA).
[0119] Experiments using naturally-infected RAG1 −/− mice co-housed with B6 and STAT1 −/− mice suggest that both innate and adaptive immunity control MuAstV replication. Since the high level, sustained shedding observed in RAG1 −/− mice may confound the kinetics of MuAstV replication and clearance in co-housed B6 and STAT1 −/− mice, MuAstV shedding in B6 and STAT1 −/− mice orally inoculated with a filtered fecal stock of MuAstV containing 5×10 5 genome copies of MuAstV was re-examined ( FIG. 8 ). Peak MuAstV shedding was reached 6 days after inoculation in B6 and STAT1 −/− mice. MuAstV shedding was elevated in STAT1 −/− mice compared to B6 mice confirming a role for innate immunity in control of MuAstV replication ( FIG. 8 ). MuAstV shedding declined to baseline in B6 and STAT1 −/− mice 16 days after inoculation ( FIG. 8 ), demonstrating that innate immunity can not necessarily be required to control MuAstV clearance.
Example 12
[0120] This example illustrates specificity of an ELISA for Astrovirus (AstV) virus-like particles (VLP), and that an ELISA can be used to detect AstV-specific antibodies in mice previously infected with AstV.
[0121] Astrovirus VLP generation—The astrovirus capsid protein can assemble into virus-like particles (VLP) which share the biological properties of virions (Moser, L., et. al., J. Virol. 81:11937-45, 2007). To generate virus-like particles, cDNA corresponding to ORF2 of STL CY2 was tagged with a 3′ TEV recognition site and 6×His tag and cloned into a pFastBac1 donor vector (Invitrogen) for baculovirus expression. Protein was generated and astrovirus VLPs were purified.
[0122] Astrovirus ELISA validation—ELISA plates were coated with serial dilutions of astrovirus VLPs and blocked with 3% BSA prior to use. Serum samples from mock and infected mice were added to the ELISA plate at a 1:100 dilution. Astrovirus VLP-specific antibodies were detected by goat-anti-mouse HRP antibodies (Jackson Immunoresearch) and ABTS peroxidase substrate (ThermoScientific) Signal was detected using a BioRad IMARK microplate reader at 415 nm. Based on the interpolated standard curve ( FIG. 9 ), a concentration of 0.1 ng/L astrovirus VLPs was selected for use in future experiments.
[0123] To further test for specificity, ELISA plates were coated with astrovirus VLPs or UV-inactivated murine norovirus MNV virions. Serum samples from mock, AstV-infected, and MNV-infected mice were analyzed. The data ( FIG. 10 ) validate specificity of the test.
[0124] Astrovirus ELISA screen—C57BL/6J mice were orally inoculated on days 0 and/or 18 with 5e5 genome copies of a heterogeneous AstV solution or PBS (mock infected). At day 34 post infection, serum was collected for analysis by ELISA. ( FIG. 11 ). The data illustrate detection of murine astrovirus antibodies by ELISA.
[0125] All references cited herein are incorporated by reference, each in its entirety. Applicant reserves the right to challenge any conclusions presented by the authors of any reference. | Novel murine astroviruses, and methods of detecting the viruses are disclosed. Also disclosed are uses of the viruses and infected animals as model systems for discovery and development of vaccines and therapies for diseases caused by or associated with astrovirus infection, including human astrovirus-based diseases. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to provisional application No. 62/115,181, filed Feb. 12, 2015, entitled Frame and Removable Lampshade, naming the inventor as: Mark A. Kimmet
FIELD
[0002] The present invention relates to the field of lampshades and particularly relates to a lampshade having a frame and an easily removable shade.
BACKGROUND
[0003] Lampshades are typically constructed on a wire frame with a cloth shade. In general, the shade is not intended to be separated from the frame. Of course, it is possible to separate the shade and replace the shade, but it is generally difficult and not frequently done. Even in lampshades that have been designed for easy removal of the shade, the process remains cumbersome. In the embodiments described herein the deficiencies of prior lampshades have been overcome by providing a lampshade that has a sturdy attractive frame and the shade itself is designed for easy convenient attachment and removal.
[0004] In one embodiment, the lampshade includes a frame and a shade. The frame has a generally cylindrical shape and includes upper and lower cylindrical flanges. A plurality of middle flanges extend between the upper and lower cylindrical flanges, and the plurality of windows are formed by the flanges. A plurality of projections extend inwardly from the lamp shade frame for holding the shade. The shade is dimensioned to fit within the generally cylindrical shape of the frame. The shade includes apertures that are dimensioned to snuggly receive or fit over each of the plurality of projections on the interior of the frame. The apertures on the shade are positioned such that the shade will fit completely within the lampshade frame and cover the plurality of windows. Thus, the apertures in the shade are mounted on the projections to securely hold the shade within the frame. A plurality of covers are configured for releasably attaching to the plurality of projections after the shade is mounted thereon. Thus, the covers may be used to hold or capture the shade on the projections within the frame and thereby secure the shade within the frame.
[0005] To mount the lampshade on an electric lamp, a spider is provided. The spider is preferably constructed with arms made of a resilient flexible material such as a metal wire, and the arms extend outwardly from a central hub. The configuration of the hub is designed to fit on an electric lamp and it will vary from this configuration depending upon the type of electric lamp on which the lampshade is being mounted. In most configurations, the hub is constructed of stamped metal, but any material of suitable strength and heat resistance may be used for the hub. The spider is held in position within the frame by the resiliency of the frame and the resiliency of the spider itself. Preferably, hoops are formed on the outside ends of the arms distal from the hub. The hoops are dimensioned to fit relatively snuggly over the covers on the projections. To mount the spider within the frame, the arms of the spider must be flexed inwardly so that they fit over the covers. At the same time that the spider arms are flexed, the frame itself may be flexed to allow the hoops to be positioned over the covers. Once the hoops are properly positioned, the arms and the frame will return to a non-flexed position to the extent possible with the hoops sliding over the covers in an outward direction. The resiliency of both the arms and the frame hold the spiders in place on the lampshade.
[0006] In this configuration, the spider may be easily attached and removed from the lampshade and similarly the covers may be quickly removed from the projections so that the shade can be removed and replaced with another shade of the same dimensions and configuration. Thus, the lampshade will accommodate numerous different shades and the shades may be easily replaced if desired. In one embodiment, a plurality of images are printed or otherwise formed on the shade. The number of images is equal to the number of windows in the lampshade frame, and the images are disposed on the shade so that each image will be positioned at least partially within a window when the shade is mounted in the frame. Thus, the lampshade frame may function as a plurality of picture frames displaying a plurality of images. In alternate embodiments at least one image may be formed on the shade and the image may be positioned at least partially in at least one window when the shade is mounted the frame. In this embodiment an image may overlap the windows and appear in more than one window.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Further advantages of the invention are apparent by reference to the detailed description when considered in conjunction with the FIGS., which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
[0008] FIG. 1 is a perspective view of a sheet metal blank used to construct a lampshade frame for holding replaceable shades;
[0009] FIG. 2 Is a perspective view of the sheet metal blank after processing to create curvature in the blank;
[0010] FIG. 3 is a plan view of a lamp shade held by the lampshade frame;
[0011] FIG. 4 is a plan view of a shade showing multiple images on the shade for being displayed and held by the lampshade frame;
[0012] FIG. 5 is a perspective view of the lampshade frame after it has been assembled into its final configuration;
[0013] FIG. 6 is a detailed view of a screw and cylindrical nut holding the opposite ends of the lampshade frame together to form a frame having a cylindrical configuration;
[0014] FIG. 7 is a disassembled view of the screw and nut shown in FIG. 6 .
[0015] FIG. 8 is a rubber cover that is mounted on the nut within the assembled lampshade frame;
[0016] FIG. 9 is a is a perspective illustration of a shade being manually inserted into an assembled lampshade frame;
[0017] FIG. 10 is a perspective view of a shade mounted within the lampshade frame and held on the cylindrical nuts;
[0018] FIG. 11 is a perspective view of a spider that is mounted within the assembled frame;
[0019] FIG. 12 is a perspective view of the shade and lampshade frame assembled with a spider mounted thereon held in place by the spring force of the frame and spider;
[0020] FIG. 13 is a front perspective view of the assembled lampshade and frame;
[0021] FIG. 14 a back perspective view of the lampshade and frame;
[0022] FIGS. 15, 16 and 17 are top, side and front views of a spider that may be used in the assembled lampshade frame;
[0023] FIGS. 18, 19 and 20 are top, side and front views of another spider that may be used in the assembled lampshade and frame;
[0024] FIG. 21 is a plan view of a metal blank for use in making a lampshade frame;
[0025] FIG. 22 is a plan view of another metal blank for use in making a lampshade frame;
[0026] FIG. 23 is a perspective of a tall slender lamp shade frame having rectangular panels;
[0027] FIG. 24 is a perspective view of a short lamp shade frame having square panels;
[0028] FIG. 25 is a plan view of a blank 98 used to construct the lampshade frame of FIG. 23 ;
[0029] FIG. 26 is a plan view of a blank 100 used to construct the lampshade frame of FIG. 24
[0030] FIG. 27 is a perspective view of a frustro-conically shaped lamp shade frame having a circular cross-section;
[0031] FIG. 28 is a plan view of a blank used to construct the lamp shade frame of FIG. 27 ;
[0032] FIG. 29 is a perspective view of a frustro-conically shaped lamp shade frame having a square cross-section; and
[0033] FIG. 30 is a plan view of a blank used to construct a frame of FIG. 29 .
DETAILED DESCRIPTION
[0034] Referring now to the drawings in which like reference characters to designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a metal blank 32 that is used to construct a frame 52 for holding a lampshade 44 , both of which are best shown in FIG. 12 . The blank 32 is originally constructed with a flat or planar configuration and may be stamped from a metal sheet such as an aluminum sheet. Alternatively, it could be constructed from a resilient strong polymer, such as nylon, PVC or polypropylene; or a cellulose based material, such as bamboo, wood or paper; or a resin based product such as fiberglass or carbon fiber. The blank 32 includes a lower horizontal flange 34 and an upper horizontal flange 36 . Extending between the upper and lower flanges 34 and 36 are two vertical middle flanges 38 and two vertical and flanges 40 . In this configuration the blank 32 forms a thin-walled beam structure suitable for assembly into the lampshade frame 52 ( FIG. 12 ). The blank further includes a plurality of apertures 42 that are spaced apart along the lower flange 34 and the upper flange 36 . The apertures 34 are dimensioned to receive hardware for holding the blank 32 in the shape of the frame 52 and for holding the shade 44 in the frame as will hereinafter be described.
[0035] As a first step in forming the lampshade, the metal blank 32 may be cold rolled to place a slight continuous bend into the blank 32 such that it adopts the configuration shown in FIG. 2 . In this configuration, the outer surface of the blank 32 stretched or tensioned and the inner surface is relatively compressed. Thus, the blank is predisposed to adopt a cylindrical shape during later assembly.
[0036] Referring now to FIG. 3 , there is shown a shade 44 that has a rectangular configuration that will precisely match the shape of the blank 32 . The shade 44 may have slightly smaller exterior dimensions such that it will fit within the overall dimensions of the blank 32 . Apertures 43 formed in the shade 44 spaced apart along the upper and lower edges of the state 44 . The apertures 43 are positioned in the shade 44 such that they will precisely align with the apertures 42 in the blank 32 when the blank is curved into a cylindrical shape.
[0037] Referring to FIG. 4 , the opposite side of the shade 44 is shown, which is normally the exterior side of the shade. In this view, it is seen that the shade 44 includes three images 46 , 48 and 50 that are dimensioned to be viewed when the shade 44 is mounted in the frame 52 . In FIG. 5 a top perspective view of an assembled lampshade frame 52 is shown. To form a generally cylindrical lampshade frame 52 the upper and lower horizontal Flanges 34 and 36 have been curved and placed into tension until they form a cylinder shape. The two end flanges 40 precisely overlap each other, and the apertures 42 are aligned to such that the two end flanges 40 may be secured together by screws 54 and nuts 56 that are positioned and secured through the apertures 42 . The two end flanges 40 are secured together by two screws 54 and nuts 56 . In this cylindrical configuration, three windows 60 , 62 and 64 are created within the lampshade frame 52 . The vertical margins of the windows are defined by the two middle vertical flanges 38 and by the two end flanges 40 . The horizontal margins of the windows 60 , 62 and 64 are defined by the upper and lower horizontal flanges 36 and 38 . The images 46 , 48 and 50 are dimensioned and positioned to be framed by the windows 60 , 62 and 64 , and the apertures 43 and 44 are configured to ensure that the images are properly positioned within the windows.
[0038] While FIG. 4 displays three identical images 46 , 48 and 50 , it will be understood that the images may be different if desired. For example, the lampshade 44 may be constructed with personal images printed on the shade. Or example, different wedding pictures or engagement pictures could be printed on the shade and displayed at a wedding reception. Every lamp at the reception could have three different pictures such that tens or even hundreds of pictures could be displayed. When the lampshade 44 is used at home, the lampshade could be replaced periodically to change the appearance of a lamp. For example, the pictures 46 , 48 and 50 could be different seasonal pictures and the lampshade 44 could be changed with the four seasons.
[0039] The lampshade 44 may be constructed of a white translucent material such as a polymer sheet or cloth. The material is chosen such that it may be printed on easily to create a substantially permanent set of images 46 , 48 and 50 . The material may also be heat resistant and flame resistant. In alternate embodiments the material may be laminated. For example, the interior laminate may be a paper or cloth specifically designed for printing images. The interior and exterior laminates may be transparent films designed to protect the image from abrasion, heat and oxygen. If desired, a transparent material may be used for the lampshade 44 , such as a transparent film. With both transparent and translucent lampshades 44 the image may be printed with an image (including graphics and designs) to completely cover or partially cover the windows 60 , 62 and 64 .
[0040] Detailed views of the hardware used in constructing the frame 52 are shown in FIGS. 6 and 7 . As best shown in FIG. 7 , the threaded nut 56 has a cylindrical exterior as does the head of screw 54 . The screw 54 is inserted through the apertures 42 and the nut 56 is used to secure the screws 54 in the apertures 42 . As best shown in FIG. 5 , two screws 54 are used to secure the end flanges 40 together and four additional screws 54 and nuts 56 are secured in the lampshade in positions immediately above and below the middle vertical flanges 38 . The diameter of the cylindrical nut 56 is slightly smaller than the diameter of the apertures 43 such that the six nuts 56 on the interior of the frame may be snuggly positioned within the apertures 43 when the shade 44 is mounted within the frame 52 .
[0041] The assembly of the shade 44 within the frame 52 is best illustrated in FIGS. 9 and 10 . To install the shade 44 , it is first coiled into a cylindrical shape having a diameter smaller than the frame 52 , and the shade 44 is inserted into the frame 52 is shown in FIG. 9 . Then, the apertures 43 are aligned with and positioned on the nuts 56 . In this embodiment the shade has a stiffness and a resiliency that will tend to hold the shade 44 on the nuts 56 . In other words, the resiliency of the shade 44 will cause it to uncoil and expand outwardly such that it captures itself on the nuts 56 . To further secure the shade 44 in place, rubber covers 66 are positioned on the exposed nuts 56 . The rubber covers 66 are resilient, slightly tacky and dimensioned to snuggly fit on the outside of the nuts 56 . When the covers 66 are placed on the nuts 56 , the shade 44 is captured in a desired position within the frame 42 on the nuts 56 .
[0042] Referring to FIG. 11 , a spider 70 is illustrated. The spider 70 is used to mount the lampshade onto a conventional electric lamp. Numerous different types of spider configurations are used in the lamp industry, and all of the configurations can be adapted for use in combination with the lampshade of the present invention. The spider 70 includes a central hub 72 that is used to mount the spider 72 and electric lamp. Three arms 74 extend outwardly from the hub 72 and are spaced apart by a 120°. Hoops 76 are formed on the outside ends the arms 74 and the hoops 76 are dimensioned to snuggly fit over the rubber covers 66 . To install the spider 70 , two of the hoops 76 are inserted over the rubber covers 66 mounted on the nuts 56 . The first two hoops 76 may be properly positioned over the covers 66 with only a slight bending or flexing of the arms 74 . However, the spider 70 is dimensioned such that the positioning of the third hoop 76 requires significant flexing of both the arm 74 and the frame 52 . Both are designed of resilient materials that will flex to allow proper positioning of the hoop. Once the third hoop 76 is assembled over the nut 56 , the spider is held in position by the spring resiliency of both the spider 70 and the frame 52 .
[0043] A perspective view of an assembled frame 52 and shade 44 is shown in FIG. 12 . In this view, the shade 44 has been mounted inside-out, meaning the images on the lampshade 44 are facing in when they would normally face out. This assembly was chosen to increase contrast for illustration purposes. Also, by viewing the images 46 , 48 and 50 inside the frame 52 , it is clear that the images (when facing outwardly) will be positioned to fit over and cover the windows 60 , 62 and 64 . In this view, the rubber covers 66 are positioned on the nuts 56 to hold the shade 44 in position on the frame 52 . In FIG. 12 , a spider 78 is mounted within the frame 52 in the manner described above. This particular spider 78 differs slightly from the spider 70 described above in that a different type of hub 80 is used. This different hub 80 is designed to fit a different type of conventional electrical lamp. However, otherwise the spider is configured similarly with flexible resilient arms 74 extending outwardly from the hub 80 . The arms 74 extend outwardly and terminate at hoops similar to hoops 76 disclosed in FIG. 11 . Such hoops are positioned over the rubber covers 66 to mount the spider 78 within the frame 52 .
[0044] A front view of the assembled frame 52 and shade 44 is shown in FIG. 13 and a back view of the frame 52 and shade 44 is shown in FIG. 14 . In these two views, it may be appreciated that the frame 52 creates three windows 60 , 62 and 64 that appear almost as picture frames surrounding a portion of the shade 44 . In these FIGS., the shade 44 is shown inside out and thus only a translucent white shade material is visible through the three windows. However, it will be appreciated that any three images could be printed on the lampshade so that the images appear in the windows 60 , 62 and 64 . Thus, when the lampshade is mounted on an electric lamp, the images would be illuminated from within and would appear as back lighted picture images. Even when placed in the shade inside out, the images would be partially visible through a translucent shade, and it may be desirable to place certain images on the interior of the frame 52 to create an effect on the appearance of the images.
[0045] FIGS. 15, 16 and 17 illustrate top, side and loop front views of the spider 78 shown in FIG. 12 . Likewise, FIGS. 18, 19 and 20 illustrate top, side and loop front views of spider 70 shown in FIG. 11 . By comparing these various views, it will be appreciated that the spiders differ slightly so as to accommodate different types of conventional electric lamps. However, they function similarly in that they are held in place by hoops 76 that are mounted on the rubber covers 66 within the lampshade frame 52 . The resiliency of the spiders 70 and 78 create spring force that will hold the spiders 70 and 78 in place within the frame 52 . Thus, a spider of this general construction may be modified in minor ways to fit any conventional lamp.
[0046] FIGS. 21 and 22 illustrate lamp shade blanks 90 and 92 similar to the blank 32 shown in FIG. 1 . As illustrated by the blanks 90 and 92 , the lampshade frame 52 may have many different dimensions such that the windows created by the frames may appear to be square, landscape rectangles, or portrait rectangles.
[0047] FIGS. 23 and 24 illustrate lamp shade frames 94 and 96 having circular cross-sections and rectangular openings or panels. These figures illustrate that the circular diameters and height of the lampshade may assume various dimensions. FIGS. 25 and 26 illustrate blanks 98 and 100 that are used to construct the frames 94 and 96 respectively.
[0048] FIG. 27 illustrates a lamp shade frame 102 having a frustoconical shape and a circular cross-section. In this particular embodiment, the frame 102 is constructed with three openings or panels through which the lamp shade is viewable.
[0049] FIG. 29 illustrates a lamp shade frame 106 having a frustoconical shape and a square cross-section. This particular embodiment illustrates that the lamp shade frame of the present invention may not have a circular cross-section. In this particular embodiment, the cross-section is square, but the cross-section could also be in the shape of any polygon, such as a triangle, a pentagon, a hexagon, etc. This particular embodiment also illustrates that the apertures 108 in the frame 106 may be placed in the mid region of the horizontal flanges and need not be placed above and below the vertical flanges.
[0050] Referring to FIG. 30 , a plan view of a blank 110 used to construct the frame 106 is shown. In this view, it may be appreciated that the apertures 108 are formed in the mid regions of lower horizontal flanges 118 , 120 and 122 . Likewise, apertures 108 are formed in the mid regions of the upper horizontal flanges 112 , 114 and 116 . These apertures are designed to receive hardware, such as the bolts described above, that in turn secure a lampshade to the frame 106 .
[0051] Apertures 108 are also formed adjacent the ends of lower horizontal flanges 126 and 130 . Likewise, apertures 108 are formed adjacent the ends of upper horizontal flanges 124 and 128 . When the blank 110 is assembled into the frame 106 , the vertical flanges of the blank 110 are bent approximately 90° along crease lines 132 forming the frustoconical shape shown in FIG. 29 . In that configuration, flange 124 overlaps flange 128 and flange 126 overlaps flange 130 with the apertures 108 in the ends of the flanges being aligned. Thus, a nut and bolt may be used to secure flange 124 to flange 128 and flange 126 to flange 130 . When secured together, flanges 126 and 130 form a single horizontal flange in the frame 106 . Likewise flanges 124 and 128 form a single upper horizontal flange in the frame 106 .
[0052] From the above discussion of different embodiments and variations, it will be appreciated that the invention is capable of numerous rearrangements, modifications and and substitutions of parts without departing from the scope of the invention as defined by the appended claims. The embodiments described herein are intended as examples and should not be construed as limitations. | A lampshade includes a frame having a shape that forms a plurality of windows. A shade fits within the frame mounted on projections extending from the frame. Apertures in the shade receive the projections, and covers are resiliently affixed to the projections to capture the shade on the projections. A spider mounts the frame to an electric lamp. The spider includes a hub that attaches to an electric lamp and a plurality of arms that are attached to the inside of the lampshade frame. In this configuration the covers, the spider and the shade are easily removed and replaced. Images are formed on the shade and are positioned to be displayed in the windows of the frame such that the windows act as picture frames. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a liquid electrophotographic printer, and more particularly, to a liquid electrophotographic printer having a development system that includes three rollers.
[0003] 2. Description of the Related Art
[0004] Electrophotographic printers such as laser printers output a desired image by forming a latent electrostatic image on a photoreceptor medium such as a photoreceptor drum or photoreceptor web, developing the latent electrostatic image with a predetermined color toner, and transferring the toner image to a print paper. Electrophotographic printers are classified into a dry type or liquid type according to the toner used. The liquid type printer uses an ink containing a volatile liquid carrier and toner particles in a predetermined ratio to implement a color image with excellent print quality. The dry type printer uses toner in a powder form.
[0005] [0005]FIG. 1 shows a conventional liquid electrophotographic printer, which uses a photoreceptor web 10 as a photoreceptor medium. The photoreceptor web 10 circulates around a continuous path by being supported by three rollers 11 , 12 and 13 , and a main charger 20 is provided adjacent to the photoreceptor web 10 to uniformly charge the photoreceptor web 10 to a predetermined potential. Laser scanning units (LSUs) 30 a , 30 b , 30 c and 30 d for emitting light beams onto the charged photoreceptor web 10 to form a latent electrostatic image, and development units 40 a , 40 b , 40 c and 40 d for developing the latent electrostatic image as a toner image with a predetermined color ink are provided below the photoreceptor web 10 . The conventional liquid electrophotographic printer includes a drying unit 50 for drying the developed image, a transfer unit 60 for printing the dried image on a print paper P, and an eraser 70 for removing the remaining latent electrostatic image from the surface of the photoreceptor web 10 . For a color printer, the four development units 40 a , 40 b , 40 c , and 40 d for sequentially developing four color toner images of yellow (Y), cyan (C), magenta (M), and black (K), respectively, to implement a multi-color image are provided. The four LSUs 30 a , 30 b , 30 c , and 30 d are provided corresponding to the number of the development units.
[0006] The drying unit 50 includes a drying roller 51 which rotates in contact with the photoreceptor web 10 and absorbs the liquid carrier from the surface of the photoreceptor web 10 , and a heat roller 52 for evaporating the liquid carrier absorbed by the surface of the drying roller 51 by heating.
[0007] The transfer unit 60 includes a transfer roller 61 which rotates in contact with the photoreceptor web 10 and transfers the toner image formed on the surface of the photoreceptor web 10 to the print paper P, and a fusing roller 63 for hot pressing the print paper against the transfer roller 61 . Reference numerals 62 and 64 are cleaning rollers for cleaning the transfer roller 61 and the fusing roller 63 , respectively.
[0008] The four development units 40 a , 40 b , 40 c , and 40 d are arranged below the photoreceptor web 10 in series in a circulation direction of the photoreceptor web 10 . In a lower portion of the development units 40 a , 40 b , 40 c and 40 d , ink reservoirs 80 a , 80 b , 80 c and 80 d which contain Y, C, M, and K inks, are provided, respectively. In the inks contained in the ink reservoirs 80 a , 80 b , 80 c and 80 d , toner particles are mixed with a pure liquid carrier in a concentration amount of 2.5-3% solution by weight.
[0009] The structure of the development units 40 a , 40 b , 40 c , and 40 d will be described with reference to the development unit 40 a for developing a yellow (Y) toner image, referred to herein as a Y-development unit. Referring to FIG. 2, a developer roller 41 , a squeeze roller 43 and a topping corona 45 are installed in the upper portion of the Y-development unit 40 a . An ink supply nozzle 49 for supplying an ink to the gap between the photoreceptor web 10 and the developer roller 41 is installed adjacent to the developer roller 41 . A cleaning roller 47 is installed underneath the developer roller 41 . A cleaning blade 48 is affixed to the lower portion of the squeeze roller 43 . The developer roller 41 serves to make the ink adhere to a latent electrostatic image region of the photoreceptor web 10 . The squeeze roller 43 squeezes the liquid carrier out of the ink adhering to the photoreceptor web 10 . The topping corona 45 recharges the photoreceptor web 10 to a predetermined potential for development of another color image. The cleaning roller 47 and blade 48 are used for removing the excessive ink or liquid carrier remaining on the surface of the developer roller 41 and the squeeze roller 43 , respectively.
[0010] A development system of the conventional liquid electrophotographic printer having the configuration described above will now be described in greater detail.
[0011] The photoreceptor web 10 is charged to a potential of about 650 volts by the main charger 20 . The Y-LSU 30 a emits a beam onto the charged surface of the photoreceptor web 10 to form a latent electrostatic image of Y color. The Y-LSU 30 a selectively erases the surface potential of the photoreceptor web 10 to form a latent electrostatic image, so that the potential of an image region in which a latent electrostatic image is formed drops to about 100 volts or less.
[0012] The latent electrostatic image is developed into a Y-image by the Y-development unit 40 a . In particular, the surface of the developer roller 41 is charged to a potential V D of about 500 volts, and the developer roller 41 rotates in a circulation direction of the photoreceptor web 10 with a development gap G of 100-200 Φm from the photoreceptor web 10 . When a Y-ink is supplied into the gap between the photoreceptor web 10 and the developer roller 41 by the ink supply nozzle 49 , a nip N having about 6-mm width is formed between the photoreceptor web 10 and the developer roller 41 . The toner particles contained in the ink are generally charged to a positive potential. Thus, toner particles selectively adhere to an image region B having a potential relatively lower than that in a non-image region A in which no latent electrostatic image is formed, so that a high-concentration toner image is developed.
[0013] During this development process, excess ink adhering to the surface of the rotating developer roller 41 is removed by the cleaning roller 47 . The squeeze roller 43 squeezes the liquid carrier out of the developed toner image region by compression, so that a toner image having a concentration of about 50% is formed in the image region B of the photoreceptor web 10 passed through the squeeze roller 43 . The liquid carrier squeezed by the squeeze roller 43 is also removed from the surface of the squeeze roller 43 by the cleaning blade 48 . The ink and liquid carrier removed by the cleaning roller 47 and blade 48 is recovered into the ink reservoir 80 a .
[0014] After the Y-image is developed, the photoreceptor web 10 is charged again to a predetermined potential by the topping corona 45 for development of a next color image, i.e., a C-image. The C-LSU 30 b emits a light beam onto the surface of the photoreceptor web 10 to form a latent electrostatic image of C color. The latent electrostatic image is developed into a C-toner image by the C-development unit 40 b.
[0015] As described above, the images of four colors are sequentially developed in the order of Y, C, M, and K, so that a full color image is formed. The developed color image is dried in the drying unit 50 to the extent of appropriately performing a subsequent transfer process, and in turn transferred to the print paper P in the transfer unit 60 .
[0016] However, the conventional liquid electrophotographic printer which operates with the configuration, as described above, has the following problems.
[0017] First, two layers are formed on the surface of the photoreceptor web 10 passed through the developer roller 41 , including a high-concentration ink layer adhering to the image region B, and a liquid carrier layer covering the non-image region A and the ink layer. Here, no toner particles should exist in the liquid carrier layer. However, it is difficult to completely remove toner particles from the liquid carrier layer, and thus actually about 0.5% toner particles exist in the liquid carrier. Accordingly, even after the liquid carrier is mostly removed by the squeeze roller 43 , a thin liquid carrier film containing toner particles remains in the non-image region A of the photoreceptor web 10 . As the photoreceptor web 10 circulates, the toner particles in the thin liquid carrier film are carried into the C-development unit 40 b and are mixed with toner particles of another color. As a result, the C-development unit 40 b , M-development unit 40 c , and K-development unit 40 d arranged in the order, and the inks contained in the development units are sequentially contaminated. In addition, toner particles remaining in the non-image region A are also transferred to the print paper P in the transfer unit 60 , so that the non-image region of the print paper P is smeared.
[0018] Second, when the liquid carrier is squeezed out of the image region B of the photoreceptor web 10 by the squeeze roller 43 , a part of the image may adhere to the surface of the squeeze roller 43 by compression force applied to the image region B of the photoreceptor web 10 . In this case, the part of the image remaining on the surface of the squeeze roller 43 may be transferred onto a next color image.
[0019] Third, when the liquid carrier is squeezed out of the image region B of the photoreceptor web 10 by the squeeze roller 43 , the image formed in the image region B is compressed and thus forced beyond its intended edge, so that it extends into the neighboring non-image region or other color image regions.
[0020] The problems described above degrade the overall quality of color images.
SUMMARY OF THE INVENTION
[0021] To solve the problems of the prior art, it is an aspect of the present invention to provide a liquid electrophotographic printer adopting a development system including three rollers, one of which is a toner removal roller, in which contamination of a development unit is prevented and image quality improved.
[0022] To achieve the foregoing aspect of the present invention, there is provided a liquid electrophotographic printer comprising: a photoreceptor web circulating around a continuous path, having a non-image region charged by a main charger to a first potential and an image region in which a latent electrostatic image is formed by a laser scanning unit to have a second potential, wherein the second potential is lower than the first potential; a development unit for developing the latent electrostatic image using an ink in which toner particles of a predetermined color are dispersed in a liquid carrier; a drying unit for drying a developed toner image; and a transfer unit for transferring a dried image to a print paper, wherein the development unit comprises: a developer roller rotatably installed with a predetermined separation gap from the photoreceptor web, for forming the toner image by attaching the toner particles of the ink to the image region; a toner removal roller rotatably installed with a predetermined separation gap from the photoreceptor web, for removing toner particles remaining in a liquid carrier film adhering to the non-image region; and a squeeze roller rotatably installed in contact with the photoreceptor web, for squeezing the liquid carrier out of the toner image by compressing the toner image.
[0023] In one embodiment, the surface of the developer roller is charged to a third potential whose level is between the first and second potentials. In this case, preferably, the third potential is at least 100 volts lower than the first potential.
[0024] In another embodiment, the surface of the toner removal roller is charged to a fourth potential whose level is between the potential of the non-image region passed through the developer roller and the potential of the image region passed through the developer roller. Preferably, the fourth potential is at least 50 volts lower than the potential of the non-image region passed through the developer roller. Preferably, the toner removal roller rotates in a direction opposite to a circulation direction of the photoreceptor web.
[0025] In still another embodiment, the surface of the squeeze roller is charged to a fifth potential whose level is higher than the first potential so as to recharge the surface of the photoreceptor web to a predetermined potential. Preferably, the squeeze roller is formed of a resistive material having a resistance of 10 5 -10 9 Ω.
[0026] Further, a method utilizing the above described apparatus is employed to overcome the problems evident in the prior art.
[0027] Thus, according to the present invention, contamination of the development unit and the inks is prevented and image quality is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The above aspect 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:
[0029] [0029]FIG. 1 is a schematic diagram showing the main parts of a conventional liquid electrophotographic printer;
[0030] [0030]FIG. 2 is a schematic diagram showing the inner structure and the development process of the development unit of FIG. 1;
[0031] [0031]FIG. 3 is a schematic diagram showing the structure of the main parts of a liquid electrophotographic printer according to the present invention;
[0032] [0032]FIG. 4 is a schematic diagram showing the inner structure of the development unit of the liquid electrophotographic printer of FIG. 3 according to the present invention;
[0033] [0033]FIG. 5 is a schematic diagram showing the development unit of the liquid electrophotographic printer according to the present invention for describing the development system thereof in detail; and
[0034] [0034]FIG. 6 is a schematic diagram showing the potential conditions and potential variations for the constituent elements of the development unit of the liquid electrophotographic printer according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] An exemplary embodiment of a liquid electrophotographic printer according to the present invention will be described in greater detail with reference to the appended drawings. The main elements of a liquid electrophotographic printer according to the present invention are shown in FIG. 3. Referring to FIG. 3, the liquid electrophotographic printer uses a photoreceptor web 110 as a photoreceptor medium. When the photoreceptor medium in the form of a belt is used, a color image is implemented by sequentially forming overlapping multiple color images. The multiple color images are simultaneously transferred to a printer paper P through a single transfer process. Thus, the print speed of the liquid electrophotographic printer is faster than an electrophotographic printer using a drum-type photoreceptor medium and the image quality is also better.
[0036] The photoreceptor web 110 circulates around a continuous path and is supported by three rollers 111 , 112 and 113 , including a driving roller and a steering roller. A main charger 120 is provided adjacent to the photoreceptor web 110 to uniformly charge the photoreceptor web 110 to a predetermined potential.
[0037] Laser scanning units (LSUs) 130 a , 130 b , 130 c and 130 d for emitting light beams onto the charged photoreceptor web 110 to form a latent electrostatic image, and development units 140 a , 140 b , 140 c and 140 d for developing the latent electrostatic image as a toner image with a predetermined color ink are provided below the photoreceptor web 110 . For a color printer, four development units 140 a , 140 b , 140 c and 140 d for sequentially developing overlapping four color toner images of yellow (Y), cyan (C), magenta (M), and black (K), respectively, are provided to implement a multi-color image. The four LSUs 130 a , 130 b , 130 c and 130 d are also provided for forming latent images of each respective color. The four development units 140 a , 140 b , 140 c and 140 d are arranged below the photoreceptor web 110 in series in a circulation direction of the photoreceptor web 110 . In a lower portion of the development units 140 a , 140 b , 140 c and 140 d , ink reservoirs 180 a , 180 b , 180 c and 180 d are provided. Ink reservoirs 180 a , 180 b , 180 c and 180 d contain Y, C, M, and K inks, respectively. In the inks contained in the ink reservoirs 180 a , 180 b , 180 c and 180 d , toner particles are dispersed in a pure liquid carrier in a concentration amount of about 2.0-3%, preferably 2.5%, by weight. The inks having an appropriate conductivity are prepared. This will be described later. The four color images may be developed in the order of Y, M, C, and K.
[0038] The developed image is dried by the drying unit 150 to the extent that a subsequent transfer process can be appropriately performed. The drying unit 150 includes a drying roller 151 which rotates in contact with the photoreceptor web 110 and absorbs the liquid carrier from the surface of the photoreceptor web 110 , and a heat roller 152 for evaporating the liquid carrier absorbed by the surface of the drying roller 151 by heating.
[0039] The liquid electrophotographic printer includes a transfer unit 160 for printing the dried image on a print paper P. The transfer unit 160 includes a transfer roller 161 which rotates in contact with the photoreceptor web 110 and transfers the toner image formed on the surface of the photoreceptor web 110 to the print paper P, and a fusing roller 163 for hot pressing the print paper against the transfer roller 161 . Reference numerals 162 and 164 are cleaning rollers for cleaning the transfer roller 162 and the fusing roller 163 , respectively.
[0040] An eraser 170 for removing the remaining latent electrostatic image from the surface of the photoreceptor web 110 may be provided.
[0041] The main feature of the present invention is the structure of the development units 140 a , 140 b , 140 c , and 140 d . The four development units 140 a , 140 b , 140 c , and 140 d have the same structure, and the structure of the development units 140 a , 140 b , 140 c , and 140 d will be described in greater detail with reference to the Y-development unit 140 a for developing a Y-image.
[0042] Referring to FIG. 4, three rollers including a developer roller 141 a , a toner removal roller 142 , and a squeeze roller 143 are installed in an upper portion of the Y-development unit 140 a . The liquid electrophotographic printer according to the present invention employs the development system that uses three rollers. The developer roller 141 makes the toner particles of the ink to adhere to the latent electrostatic image region of the photoreceptor web 110 to develop the latent electrostatic image into a toner image. The toner removal roller 142 removes the toner from the liquid carrier layer adhering to a non-image region of the photoreceptor web 110 . To this end, a predetermined voltage is applied to the toner removal roller 142 . This will be described later. The squeeze roller 143 a presses a portion of the photoreceptor web 110 in which the toner image is formed to squeeze excess liquid carrier from the portion. Also, a relatively high-voltage is applied to the squeeze roller 143 to charge the photoreceptor web 110 to a predetermined potential for the development of another color image. The squeeze roller 143 according to the present invention also performs the functions of the topping corona 45 (see FIG. 2) of the conventional liquid electrophotographic printer. To this end, at least the surface of the squeeze roller 143 is formed of a resistive material with a high resistance of 10 5 -10 9 Ω, preferably 10 6 Ω. For example, the resistive material may be a synthetic material formed of urethane rubber and carbon.
[0043] As described above, although the development unit 140 a of the liquid electrophotographic printer according to the present invention includes one more roller 141 , 142 , and 143 than the conventional development unit of a printer, there is no increase in the overall volume of the development unit 140 a because there is no need to install the topping corona 45 (FIG. 2) therein.
[0044] An ink supply nozzle 149 is installed adjacent to the developer roller 141 . The ink supply nozzle 149 serves to supply the ink contained in the ink reservoir 180 a to the gap between the photoreceptor web 110 and the developer roller 141 . Cleaning rollers 147 and 148 rotating in contact with the developer roller 141 and the toner removal roller 142 are installed underneath the developer roller 141 and the toner removal roller 142 . The two cleaning rollers 147 and 148 remove the ink adhering to the surface of the development roller 141 and the toner removal roller 142 , respectively. The cleaning rollers 147 and 148 are a cleaning means for cleaning the development roller 141 and the toner removal roller 142 , and are replaced with blades (not shown) in an alternative embodiment. In another alternative embodiment, both the cleaning rollers 147 and 148 and a blade are utilized. Since no toner particles adhere to the squeeze roller 143 , an additional cleaning means is not required for the squeeze roller 143 .
[0045] The development system of the liquid electrophotographic printer according to the present invention, which has the configuration described above, will be described with reference to FIGS. 5 and 6.
[0046] The photoreceptor web 110 is charged by the main charger 120 to a first potential of 500-600 volts, and preferably, about 550 volts. The Y-LSU 130 a emits a beam onto the surface of the charged photoreceptor web 110 to form a latent electrostatic image corresponding to a yellow color image. The Y-LSU 130 a selectively erases the potential of the surface of the photoreceptor web 110 to form the latent electrostatic image. Thus, a potential V BY (not shown) of an image region B 1 , where the latent electrostatic image is formed, drops to a second potential of about 150 volts or less; for example, 100 volts. A potential V A (not shown) of a non-image region A 1 is kept at the first potential, i.e., 550 volts, charged by the main charger 120 .
[0047] The latent electrostatic image is developed into a Y-toner image by the Y-development unit 140 a . In particular, as the photoreceptor web 110 passes over the developer roller 141 , Y-toner particles adhere to the image region B 1 , in which the electrostatic latent image is formed, to form a Y-toner image. As a predetermined voltage is applied to the developer roller 141 , the surface of the developer roller 141 is charged to a third potential V D of 300-400 volts, and preferably, about 350 volts. The third potential V D of the development roller 141 is determined to be lower than the first potential V A (550V) of the non-image region A 1 and to be higher than the second potential V BY (100V) of the image region B 1 . It is preferable that the differences between the third potential V D and each of the first and second potentials V A and V BY are at least 100 volts or more, and preferably 200 volts or more. As the potential differences become greater, the affinity of toner particles to the photoreceptor web 110 and the developer roller 141 becomes more apparent. The developer roller 141 rotates in the circulation direction of the photoreceptor web 110 with a development gap G D of 100-200 μm from the photoreceptor web 110 . As the ink containing Y-toner particles of about 2.5% solution by weight, contained in the Y-ink reservoir 180 a , is supplied to the gap between the photoreceptor web 110 and the developer roller 141 by an ink supply means, i.e., by the ink supply nozzle 149 , a nip ND as a liquid carrier film having about 6-mm width is formed between the photoreceptor web 110 and the developer roller 141 .
[0048] The toner particles of the ink are charged to a positive potential and move in the nip N D as follows. The second potential V BY (100 volts) of the image region B 1 of the photoreceptor web 110 is lower than the third potential V D (350 volts) of the development roller 141 , so that the toner particles move towards the image region B 1 and adhere to the image region B 1 . The first potential V A (550 volts) of the non-image region A 1 is greater than the third potential V D (350 volts) of the developer roller 141 , so that the toner particles move towards the developer roller 141 and adhere to the surface of the developer roller 141 . Thus, the toner particles selectively adhere to only the image region B 1 charged to a relatively low potential, so that a toner image is formed therein. Excess ink and toner particles stuck to the surface of the rotating developer roller 141 are removed by the cleaning roller 147 .
[0049] In an image region B 2 of the photoreceptor web 110 , which has passed the developer roller 141 , a high-concentration ink layer and a liquid carrier film covering the ink layer are formed. Only the liquid carrier film exits in a non-image region A 2 . However, even after the photoreceptor web 110 has passed the developer roller 141 , toner particles of about 0.5% remain in the liquid carrier film. Once the image region B 1 and the non-image region A 1 of the photoreceptor web 110 pass the developer roller 141 , due to the ink layer or the liquid carrier film existing in the image region B 2 and the non-image region A 2 , the second potential V BY of the image region B 2 increases to about 160 volts and the first potential V A of the non-image region A 2 drops to about 380 volts, as shown in FIG. 6.
[0050] Next, when the photoreceptor web 110 passes the toner removal roller 142 , the toner particles existing in the liquid carrier film adhering to the non-image region A 2 are removed, so that a toner-free liquid carrier film remains. In particular, as a voltage is applied to the toner removal roller 142 , the surface of the toner removal roller 142 is charged to a fourth potential V R of about 250 volts. The fourth potential V R of the toner removal roller 142 is determined to be higher than the second potential V BY (160 volts) of the image region B 2 and to be lower than the first potential V A (380 volts) of the non-image region A 2 . It is preferable that the difference between the fourth potential V R of the toner removal roller 142 and the first potential V A of the non-image region A 2 is at least 50 volts or more. The greater the potential difference, the easier the removal of the unnecessary toner particles from the liquid carrier film. The toner removal roller 142 is installed with a separation gap G R of 100-200 μm from the photoreceptor web 110 , and a nip N R having a width of 1-3 mm is formed between the toner removal roller 142 and the photoreceptor web 110 . The width of the nip N R may be adjusted according to the diameter of the toner removal roller 142 and the width of the gap G R . The toner removal roller 142 may rotate in any direction. However, it is preferable that the toner removal roller 142 rotate in a direction opposite to the circulation direction of the photoreceptor web 110 for easier formation of the nip N R .
[0051] The toner particles move in the nip N R formed between the photoreceptor web 110 and the toner removal roller 142 as follows. The first potential V A (380 volts) of the non-image region A 2 of the photoreceptor web 110 is higher than the fourth potential V R (250 volts) of the toner removal roller 142 , so that the toner particles remaining in the liquid carrier film move toward the toner removal roller 142 . The second potential V BY (160 volts) of the image region B 2 is lower than the fourth potential V R (250 volts) of the toner removal roller 142 , so that the toner particles move toward the image region B 2 and adhere to the image region B 2 . The toner particles and liquid carrier adhering to the surface of the rotating toner removal roller 142 are removed by the cleaning roller 148 . When the photoreceptor web 110 passes through the toner removal roller 142 , the second potential V BY of the image region B 2 and the first potential V A of the non-image region A 2 slightly change, as shown in FIG. 6.
[0052] The liquid carrier film is formed while the photoreceptor web 110 passes the Y-development unit 140 a . Toner particles remaining in the liquid carrier film adhering to the non-image region A 2 can be almost completely removed by the toner removal roller 142 , thereby resulting in a toner-free liquid carrier film in the non-image region A 3 passed through the toner removal roller 142 . As a result, the problems caused by the conventional technique can be solved. In other words, the transfer of Y-toner particles remaining in the liquid carrier film to the next C-development unit 140 b is prevented. Thus, the problem of the successive contamination of the C-, M-, and K-development units 140 b , 140 c and 140 d , and the inks contained therein is solved. No toner particles exist in the non-image region of the photoreceptor web 110 . Therefore, the problem of ink smearing in the non-image region of the print paper P is solved.
[0053] As the photoreceptor web 110 passes the squeeze roller 143 , the developed toner image region of the photoreceptor web 110 is pressed by the squeeze roller 143 , so that excess liquid carrier is squeezed from the toner image. In particular, the squeeze roller 143 rotates in the circulation direction of the photoreceptor web 110 in contact with the photoreceptor web 110 with a compression force of, for example, about 20 kgf. As a result, the liquid carrier covering the toner image formed in the image region B 3 of the photoreceptor web 110 , and the liquid carrier adhering to the non-image region A 3 are mostly removed. When the photoreceptor web 110 has passed the squeeze roller 143 , a toner image having about 50% toner particles is formed in the image region B 3 of the photoreceptor web 110 .
[0054] As described above, the squeeze roller 143 can charge the photoreceptor web 110 to a predetermined potential to develop another color image. To this end, a relatively high voltage is applied to the squeeze roller 143 such that the surface of the squeeze roller 143 is charged to a fifth potential V S of about 800 volts or greater, and preferably, about 900 volts. At that exemplary value of V S , the first potential V A of the non-image region A 3 of the photoreceptor web 110 passed through the squeeze roller 143 increases to about 820 volts and the second potential V BY of the image region B 3 increases to about 750 volts, as shown in FIG. 6. These potential levels may slightly vary depending on the property of the squeeze roller 143 . When the surface of the squeeze roller 143 is charged to a high potential, the toner particles forming the toner image much more strongly adhere to the image region B 3 due to the repulsive force exerted between the squeeze roller 143 and the toner particles. Thus, although the toner image is compressed by the squeeze roller 143 , the edge of the toner image does not spread and a part of the toner image does not stick to the surface of the squeeze roller 143 .
[0055] After a Y-toner image is developed through the procedure above, the C-LSU 130 b emits a beam onto the surface of the photoreceptor web 110 to develop another color image, i.e., a C-toner image, so that a latent electrostatic image corresponding to a cyan image is formed. The latent electrostatic image has a potential V BC of about 100 volts and is developed into a C-toner image in the same manner as described above.
[0056] When the four color images of Y, C, M, and K are sequentially developed, overlapping each other, as described above, a complete color image is formed in the photoreceptor web 110 . This developed color image is dried by the drying unit 150 such that it can be appropriately transferred, and is transferred to the print paper P by the transfer unit 160 .
[0057] To sequentially develop the overlapping four color toner images, the potential of the rollers of each of the development units 140 a , 140 b , 140 c , and 140 d , and the conductivity of the ink used in each of the development units 140 a , 140 b , 140 c , and 140 d should be appropriately adjusted, as shown in Table 1. The figures in Table 1 are obtained through many experiments performed by the present inventor, and thus a possible slight deviation above or below the levels should be considered. The potential and the ink conductivity illustrated in Table 1 may vary depending on the type and property of the photoreceptor web 110 , ink, and rollers 141 , 142 and 143 .
TABLE 1 Y- C- M- K- develop- develop- develop- develop- ment ment ment ment Items Unit Unit Unit Unit Ink Conductivity 80-150 70-150 100-200 80-200 (pMho/cm) Non-image A 1 550 820 890 900 Region A 2 380 510 590 700 Potential (V A) A 3 820 890 900 1,100 Image Region B 1 100 100 100 100 Potential (V B) B 2 160 320 340 410 B 3 750 810 780 950 Development Roller 350 500 600 600 Potential (V D ) Toner Removal Roller 250 450 500 500 Potential (V R ) Squeeze Roller 900 1,000 1,000 1,300 Potential (V s )
[0058] As shown in Table 1, the conductivity of the inks is in the range of 70-200 pMho/cm. The conductivity of the ink is appropriately adjusted within the range depending on color. The potential (third potential) of the developer roller is determined to be 200-300 volts lower than the potential (first potential) of the non-image region A 1 and 250-500 volts higher than the potential (second potential) of the image region B 1 . The potential (fourth potential) of the toner removal roller is determined to be 60-200 volts lower than the potential of the non-image region A 2 and 90-100 volts higher than the potential of the image region B 2 of the photoreceptor web 110 passed through the developer roller.
[0059] As the photoreceptor web 110 sequentially passes the C-, M-, and K-development units so that the color toner images are formed overlapping one another, the difference in the potential between the non-image region and the image region decreases. In this case, it is difficult to appropriately set the third and fourth potentials. Thus, the potential (fifth potential) of the squeeze roller is determined to be relatively higher than the other potential levels at 900-1,300 volts. As a result, the first potential of a non-image region for the next color image becomes higher, thereby increasing the difference between the first potential and the second potential of adjacent image region. Thus, the selection range of the third and fourth potential levels, which are determined as a value between the first and second potential levels, becomes wider.
[0060] The above-listed ink conductivity and potential levels are exemplary of a smooth operation of the development system according to the present invention.
[0061] As described above, the liquid electrophotographic printer according to the present invention has the following advantages.
[0062] First, since the toner particles are removed from the liquid carrier film adhering to the non-image region by the toner removal roller 142 , contamination of a next development unit and another color ink by the transfer of toner particles of a certain color to the development unit is prevented. No toner particles remain in the non-image region of the photoreceptor web 110 , so that the non-image region of print paper P is not smeared with the toner particles.
[0063] Second, the toner image is formed by the high-voltage squeeze roller 143 , so that the toner particles strongly adhere to the image region of the photoreceptor web 110 . As a result, even after the toner image is compressed by the squeeze roller 143 , the edge of the toner image does not spread and a part of the toner image does not stick to the surface of the squeeze roller 143 . A smearing of the toner image or an offset of overlapping of different color images is suppressed.
[0064] Due to these advantages, the quality of the printed color image is improved.
[0065] While this invention has been particularly shown and described with reference to exemplary embodiment(s) thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | A liquid electrophotographic printer employs a continuously circulating photoreceptor web having a non-image region with a potential higher than an image region. A laser scanner forms a latent electrostatic image in the image region, and a development unit develops the latent image using an ink having toner particles dispersed in a liquid carrier. The development unit includes a developer roller with a surface potential in between that of the image and non-image region for forming the toner image by attaching the toner particles to the image region; a toner removal roller with a surface potential between that of the image and non-image regions after they pass through the developer roller, for removing toner particles remaining in a liquid carrier film in the non-image region; and a squeeze roller with a surface potential higher than any of the foregoing, for squeezing the liquid carrier out of the toner image by compression. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Korean Patent Application No. 10-2013-0054315, filed on May 14, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] Apparatuses and methods consistent with exemplary embodiments relate to a superconducting rotating machine and a cooling method thereof, and more particularly, to a superconducting rotating machine in which a coolant for cooling a rotor having a superconductive coil is enabled to circulate naturally and compulsively, and a cooling method thereof.
[0003] A superconducting rotating machine includes a superconductive coil which must be cooled during the operation of the superconducting rotating machine. A metallic oxide superconductive material having the transition temperature higher than 77K is generally known in the art. A machine including a superconductive coil containing such a material may be cooled, for example, by liquid nitrogen.
[0004] A technique of cooling a rotor of a superconducting rotating machine is known in the related art.
[0005] The rotor includes a thermal conductive rotor body, and a superconductive coil made of a superconductive material and installed to a coil supporter.
[0006] The rotor body has a central cavity extending in an axial direction and having a cylindrical shape, in which coolant line members drawn out from the coil supporter are connected to a side surface of the central cavity. The line members extends to a condenser chamber of a cooling apparatus geodetically located at a higher position, so that the line members form a closed single-tube line system together with the condenser chamber and the central cavity.
[0007] The coolant is circulated in the line system due to the thermosiphon effect. The coolant condensed in the condenser chamber flows into the central cavity through the coolant line members. The coolant in the central cavity is thermally coupled to the superconductive coil as well as the coil supporter, so that the coolant is evaporated by absorbing heat. Then, the evaporated coolant fluid again arrives at the condenser chamber through the same line members, and then, the coolant is again condensed in the condenser chamber.
[0008] When cooling is performed by the thermosiphon effect, since the conveyance of the liquid coolant is enabled under the gravity, the cooling apparatus or the condenser chamber must be placed at a position higher than that of the coil supporter.
[0009] In addition, when the cooling is performed by the thermosiphon effect, since the rotor is cooled using a natural circulation of the coolant, the initial cooling time is too long.
SUMMARY
[0010] One or more exemplary embodiments provide a superconducting rotating machine which can improve the cooling efficiency of a rotor by using schemes of passively or actively circulating a coolant and a cooling method thereof.
[0011] Further, one or more exemplary embodiments provide a superconducting rotating machine which is configured to actively supply an external liquid coolant when a rotor of the superconducting rotating machine is initially cooled, and a cooling method thereof.
[0012] According to an aspect of an exemplary embodiment, there is provided a superconducting rotating machine including a rotor supported rotatably about a rotation axis and including: at least one superconductive coil; and a central cavity; and a cooling apparatus disposed at an exterior of the rotor and configured to communicate with the cavity, wherein the cooling apparatus includes: a condenser configured to condense a gas coolant supplied through a gas coolant supplying pipe to generate a condensed coolant; a coolant circulating unit configured to supply the condensed coolant into the cavity, configured to recover a vapor coolant evaporated in the cavity into the condenser and configured to circulate the condensed coolant; and a forced circulating unit configured to actively circulate the condensed coolant into the cavity in response to the rotor being tilted.
[0013] The coolant circulating unit may include: at least one internal coolant supplying line configured to supply the condensed coolant into the cavity; and at least one coolant recovery line configured to recover the vapor coolant into the condenser.
[0014] The forced circulating unit may include a pump connected between the condenser and the internal coolant supplying line, the pump configured to actively supply the condensed coolant of the condenser into the cavity through the internal coolant supplying line.
[0015] The superconducting rotating machine may further include an external liquid coolant supplying unit configured to actively supply an external liquid coolant into the cavity.
[0016] The external liquid coolant supplying unit may include: at least one external coolant supplying line configured to supply the external liquid coolant into the cavity; and a connecting line connecting the pump to the external coolant supplying line.
[0017] The superconducting rotating machine may further include a check valve provided at the connecting line and configured to induce the external liquid coolant to flow in one direction through the external coolant supplying line.
[0018] The internal coolant supplying line, the coolant recovery line and the external coolant supplying line may be concentrically disposed about the rotation axis.
[0019] The superconducting rotating machine may further include: a first connecting line vacuum part configured to enclose the internal coolant supplying line, the coolant recovery line and the external coolant supplying line; a second connecting line vacuum part connected to the rotor to surround the first connecting line vacuum part; and a mechanical seal provided between the first and second connecting line vacuum parts.
[0020] The superconducting rotating machine may further include: a tilt sensor configured to sense a tilt of the rotor; and a control unit configured to output a driving signal configured to drive the pump in response to the control unit receiving a tilt signal from the tilt sensor.
[0021] The superconducting rotating machine may further an initial cooling state sensor configured to determine whether the external liquid coolant is supplied through the external coolant supplying line so that a temperature of the rotor reaches an initial cooling temperature, wherein the control unit may be configured to stop driving the pump and configured to output a signal to supply a gas coolant through the gas coolant supplying line in response to the temperature of the rotor reaching the initial cooling temperature.
[0022] The initial cooling state sensor comprises at least one of a time counter configured to count an initial coolant circulating time, a temperature measuring sensor configured to measure the temperature of the rotor, and a rotation number sensor configured to check a number of rotations of the rotor.
[0023] The superconducting rotating machine may further include a vacuum housing enclosing the condenser and the pump.
[0024] According to an aspect of an exemplary embodiment, there is provided a method of cooling a superconducting rotating machine, the method including: passively circulating a coolant in a thermosiphon scheme to recover a vapor coolant into a condenser through at least one coolant recovery line, wherein the vapor coolant is generated by evaporating a condensed coolant supplied into a cavity of a rotor through at least one internal supplying line by gravity, and the condensed coolant is generated by condensing a gas coolant through the condenser of a cooling apparatus; determining whether the rotor is tilted; and actively circulating the condensed coolant to supply the condensed coolant in response to determining that the rotor is tilted.
[0025] The actively circulating the condensed coolant may be performed through a pumping force of a pump provided between the internal coolant supplying line and the condenser.
[0026] The actively circulating of the condensed coolant may include: determining whether the rotor is tilted while the passively circulating the condensed coolant is performed; and driving the pump in response the rotor being tilted.
[0027] The method may further include initially cooling the rotor by actively supplying an external liquid coolant into the cavity of the rotor before performing the passively circulating the condensed coolant.
[0028] The initial cooling of the rotor may include: actively supplying the external liquid coolant through at least one external coolant supplying line; determining whether a temperature of the rotor reaches at an initial cooling temperature by an initial cooling state sensor; and supplying the gas coolant to a cooling unit after stopping the supplying the external liquid coolant in response to the temperature of the rotor reaching the initial cooling temperature.
[0029] The condensed coolant and the external liquid coolant may be actively supplied by a single pump.
[0030] A check valve may be configured to prevent the external liquid coolant from flowing reversely while the external liquid coolant is being supplied through the external coolant supplying line.
[0031] The determining the temperature of the rotor may include at least one of counting an initial coolant circulating time, sensing the rotor temperature and checking a number of rotations of the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The above and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings in which:
[0033] FIG. 1 is a view showing an entire configuration of a superconducting rotating machine according to an exemplary embodiment.
[0034] FIG. 2 is a view of the superconducting rotating machine when seen in the direction of arrow Π of FIG. 1 according to an exemplary embodiment.
[0035] FIG. 3 is a flowchart illustrating a method of cooling a superconducting rotating machine according to an exemplary embodiment.
[0036] FIG. 4 is a flowchart illustrating an initial coolant circulating step of FIG. 3 according to an exemplary embodiment.
DETAILED DESCRIPTION
[0037] Hereinafter, exemplary embodiments will be described in more detail with reference to accompanying drawings. The present inventive concept is not limited to the following the exemplary embodiments but includes various applications and modifications. The exemplary embodiments will allow those skilled in the art to completely comprehend the scope of the present inventive concept.
[0038] FIG. 1 is a view showing a configuration of a superconducting rotating machine according to an exemplary embodiment.
[0039] Referring to FIG. 1 , the superconducting rotating machine 1 includes an outer housing 3 , a stator coil 5 installed in the outer housing 3 , and a rotor 10 placed in the outer housing 3 and surrounded with the stator coil 5 .
[0040] The rotor 10 includes a vacuum housing 11 rotatably supported based on a rotation axis A by a bearing 7 in the outer housing 3 , and a coil supporter 15 having a superconductive coil 12 and supported in the vacuum housing 11 , for example, by a hollow cylindrical torque transferring supporting member 13 .
[0041] The coil supporter 15 includes a central cavity 17 disposed concentrically with the rotation axis A and extending along the rotation axis A. The cavity 17 may have a cylindrical shape. The cavity 17 is maintained in a vacuum state by the coil supporter 15 . One side of the rotor 10 is supported in the outer housing 3 by a rotational shaft 19 .
[0042] For example, a cooling apparatus 30 may be provided at an outside of the rotor 10 while being spaced apart from the rotor 10 by several meters.
[0043] The cooling apparatus 30 includes a cooler 31 for indirectly cooling the superconductive coil 12 through a thermal conductive member. A cold head 31 a of the cooler 31 is only depicted in the drawings. The cooler 31 may be formed in a Gifford-McMahon type, a Stirling type or a pulse-tube type.
[0044] The cooling apparatus 30 may include a condenser 35 which is thermally coupled to the thermal conductive member (not shown) coupled to the cold head 31 a to condense a gas coolant G supplied through a gas coolant supplying line 33 , and a coolant circulating unit 37 which connects the cavity and the condenser 35 to each other.
[0045] The coolant circulating unit 37 allows the coolant L 1 condensed in the condenser 35 to flow into the cavity 17 . The condensed coolant L 1 is thermally coupled to the superconductive coil 12 as well as the coil supporter 15 in the cavity 17 , so that the condensed coolant absorbs heat to evaporate, and then, the evaporated coolant V returns to the condenser 35 .
[0046] The coolant circulating unit 37 includes at least one internal coolant supplying line 37 a for supplying the condensed coolant L 1 from the condenser 35 into the cavity 17 and at least one coolant recovery line 37 b for drawing back the evaporated coolant V evaporated in the cavity 17 into the condenser 35 , so that the coolant may be circulated by thermosiphon effect.
[0047] A connecting line 37 c may be further provided between the coolant recovery line 37 b and the condenser 35 .
[0048] In this case, the internal coolant supplying line 37 a and the coolant recovering line 37 b may be prepared as the same line, such that the condensed coolant L 1 and the evaporated coolant V may be circulated through the same line.
[0049] The cooling apparatus 30 may include a forced circulating unit 38 for actively supplying the condensed coolant L 1 into the cavity 17 when the rotor 10 is tilted.
[0050] The tilting of the rotor 10 corresponds to an unbalance state of the superconducting rotating machine 1 , that is, the tilting of the rotor 10 occurs when the superconducting rotating machine 1 is inclined from a horizontal state H at a predetermined angle (α°) or more when the superconducting rotating machine 1 is employed in a ship or coastal equipment. In other words, the tilting of the rotor corresponds to a state where the condenser 35 is placed at a position lower than that of the cavity 17 in the gravity direction.
[0051] Further, the tilting of the rotor 10 means that there may be a problem in the flow of the condensed coolant from the condenser 35 to the cavity 17 .
[0052] The forced circulating unit 38 may include a pump 38 a connected between the condenser 35 and the internal coolant supplying line 37 a to actively supply the condensed coolant L 1 supplied from the condenser 35 into the cavity 17 through the internal coolant supplying line 37 a . In other words, the pump 38 a moves the condensed coolant L 1 supplied from the condenser 35 into the cavity 17 through pumping action.
[0053] The superconducting rotating machine 1 may further include a tilt sensor 21 in order to determine whether the rotor 10 is tilted. For example, the tilt sensor 21 may adhere to an upper portion of the outer housing 3 . However, the exemplary embodiment is not limited thereto.
[0054] The superconducting rotating machine 1 may include a control unit 23 which outputs a driving signal to drive the pump 38 a when the superconducting rotating machine 1 receives a tilt signal indicating that the superconducting rotating machine 1 is tilted from the tilt sensor 21 .
[0055] The cooling apparatus 30 may further include an external liquid supplying unit 39 for actively supplying or moving an external liquid coolant when the rotor 10 is initially cooled.
[0056] The external liquid supplying unit 39 may include at least one external coolant supplying line 39 a and a pump to supply an external liquid coolant L 2 into the cavity 17 . The pump the same as the pump 38 a employed in the forced circulating unit 38 may be used. That is, the pump 38 a may supply the condensed coolant L 1 from the condenser 35 and the external liquid coolant L 2 supplied through the external coolant supplying line 39 a into the cavity 17 via pumping the condensed coolant L 1 and the external liquid coolant L 2 .
[0057] A connecting line 39 c may be provided between the external coolant supplying line 39 a and the pump 38 a . The connecting line 39 c may be connected to a main supplying pipe 39 e for supplying the external liquid coolant L 2 .
[0058] A control valve 45 may be provided to the main supplying pipe 39 e to be enabled to be opened or closed, such that the control valve 45 may control the supplying or blocking of the external liquid coolant L 2 .
[0059] The external liquid coolant L 2 may include an extremely low temperature liquid coolant such as liquid nitrogen.
[0060] A check valve 32 may be provided to the connecting line 39 c , such that, when the external liquid coolant L 2 is supplied by the pump 38 a through the external supplying line 39 a , the external liquid coolant L 2 is induced to flow through the connecting line 39 c along the external supplying line 39 a in a single direction and is prevented from flowing in the reverse direction.
[0061] The external liquid supplying unit 39 may further include an initial cooling state sensor 25 for sensing whether the external liquid coolant L 2 is supplied through the external coolant supplying line 39 a so that the rotor 10 is cooled at the initial cooling temperature.
[0062] The initial cooling state sensor 25 may include a counter for counting an initial coolant circulating time taken for the external liquid coolant L 2 to be circulated, a temperature sensor for sensing the temperature of the rotor 10 , and a rotation sensor for checking the rotation number of the rotor 10 .
[0063] When the control unit 23 determines that the temperature of the rotor 10 reaches the initial cooling temperature based on the signal transferred from the initial cooling state sensor 25 , the control unit 23 may stop driving the pump 38 a and may output a signal by which the gas coolant G is enabled to be supplied through the gas supplying line 33 .
[0064] The gas coolant may include at least one of neon, hydrogen and helium.
[0065] The condenser 35 and the pump 38 a are surrounded by the vacuum housing 36 of the cooling apparatus to be heat-insulated from an outside.
[0066] A first connecting line vacuum part 36 a , which surrounds the internal coolant supplying line 37 a , the coolant recovery line 37 b and the external coolant supplying line 39 a to be heat-insulated from an outside, may be provided to a portion of the vacuum housing 36 .
[0067] A second connecting line vacuum part 11 a , which surrounds the first connecting line vacuum part 36 a to be heat-insulated, may be provided to a portion of the vacuum housing 11 .
[0068] A magnetic liquid seal 41 may be provided near the vacuum housing 36 of the cooling apparatus between the first and second connecting line vacuum parts 36 a and 11 a and a mechanical seal 43 may be further provided opposite to the magnetic liquid seal 41 between the first and second connecting line vacuum parts 36 a and 11 a.
[0069] The magnetic liquid seal 41 and the mechanical seal are spaced apart from each other by a predetermined interval, so that the coolant is doubly prevented from being leaked. Specifically, the mechanical seal 43 may primarily prevent the coolant from being leaked, so that the magnetic liquid seal 41 may be prevented from being corroded by the coolant.
[0070] FIG. 2 is a view of the superconducting rotating machine when seen in the direction of arrow Π of FIG. 1 according to an exemplary embodiment.
[0071] Referring to FIG. 2 , the internal coolant supply line 37 a , the coolant recovery line 37 b and the external coolant supplying line 39 a are concentrically disposed about the rotation axis A.
[0072] At least one internal coolant supplying line 37 a may be provided and may be disposed to allow the center to be on the rotation axis A.
[0073] At least one coolant recovery line 37 b may be provided at a predetermined interval in a circumferential direction about the inner coolant supplying line 37 a.
[0074] The external coolant supplying line 39 a may be disposed between the coolant supplying line 37 a and the coolant recovery line 37 b and aligned in a circumferential direction at a predetermined interval.
[0075] Hereinafter, a method of cooling a superconducting rotating machine according to an exemplary embodiment will be described.
[0076] FIG. 3 is a flowchart illustrating a method of cooling a superconducting rotating machine according to an exemplary embodiment.
[0077] Referring to FIGS. 1 and 3 , the method of cooling a superconducting rotating machine may include a passive coolant circulating step S 30 , a rotor tilt determining step S 50 , and an active condensed coolant circulating step S 70 .
[0078] In the passive coolant circulating step S 30 , the gas coolant G supplied through the gas coolant supplying line 33 is condensed by the condenser 35 . The condensed coolant L 1 by the condenser 35 is supplied into the cavity 17 of the rotor 10 through the internal coolant supplying line 37 a by gravity.
[0079] The condensed coolant L 1 supplied into the cavity 17 is evaporated. The coolant V evaporated in a vapor type by absorbing heat flows into the condenser 35 through the coolant recovery line 37 b . The coolant circulation is achieved under the condition of using so-called “thermosiphon effect.”
[0080] In the rotor tilt determining step S 50 , the tilt sensor 23 senses a tilt of the rotor 10 .
[0081] Based on the signal received through the tilt sensor 23 , the control unit 23 determines whether the rotor 10 is tilted and then, determines whether the rotor 10 is tilted at a predetermined angle (α°) or more, so that it is impossible to supply the liquid coolant L 1 into the cavity 17 by gravity.
[0082] As described above, when it is determined in the rotor tilt determining step S 50 that the rotor is tilted, the control unit 23 outputs the pump driving signal to drive the pump 38 a.
[0083] Thus, the liquid coolant L 1 received in the condenser 35 is actively supplied into the cavity 17 by the driving force of the pump 38 a . The liquid coolant L 1 supplied into the cavity 17 is evaporated by absorbing heat and the vapor coolant V flows into the condenser 35 through the coolant recovery line 37 b.
[0084] In addition, an initial coolant circulating step S 10 for actively circulating the external liquid coolant L 2 before performing the natural coolant circulating step S 30 may be further included.
[0085] FIG. 4 is a flowchart illustrating details of the initial coolant circulating step S 10 of FIG. 3 according to an exemplary embodiment.
[0086] Referring to FIGS. 1 and 4 , the initial coolant circulating step S 10 includes an external liquid coolant supplying step S 11 , an initial cooling state determining step S 13 and a gas coolant supplying step S 15 .
[0087] In the external liquid coolant supplying step S 11 , the pump 38 a is driven and the control valve 45 is opened so that the external liquid coolant L 2 , which is liquid nitrogen, is supplied through the main supplying pipe 39 e . In this case, the control valve 45 is opened according to the signal output from the control unit 23 .
[0088] The external liquid coolant L 2 is supplied into the cavity 17 through the connecting line 39 c and the external liquid coolant supplying line 39 a.
[0089] The external liquid coolant L 2 supplied into the cavity 17 absorbs heat to evaporate into a vapor state and then, the evaporated coolant flows into the condenser 35 through the coolant recovery line 37 b , so that the evaporated coolant is re-condensed. The re-condensed coolant L 1 is supplied into the cavity 17 through the internal coolant supplying line 37 a.
[0090] While the external liquid coolant L 2 is actively pumped by the pumping force of the pump 38 a , the external liquid coolant L 2 is induced to flow in one direction by the check valve 32 provided in the connecting line 39 c , so that the external liquid coolant L 2 flows along the external liquid coolant supplying line 39 a through the connecting line 39 c and is prevented from flowing in the reverse direction.
[0091] Thus, as the external liquid coolant L 2 is compulsively supplied into the cavity 17 by the driving force of the pump 38 a , the initial cooling time of the rotor 10 may be reduced.
[0092] It is described above that the driving force for circulating the external liquid coolant L 2 is provided by the pump 38 a which actively pumps the condensed coolant L 1 , but it is understood that another pump may be used instead of the pump 38 a.
[0093] In the initial cooling state determining step S 13 , the external liquid coolant L 2 is supplied into the cavity 17 to evaporate and then, the initial cooling state of the rotor 10 is sensed through the initial cooling state sensor 25 while an initial coolant circulation operation, in which the vapor coolant is recovered into the condenser 35 to be re-condensed and the re-condensed coolant L 1 is supplied into the cavity 17 , is performed.
[0094] The sensing of the initial cooling state may be performed by counting an initial coolant circulating time, sensing the temperature of the rotor 10 or checking the rotation number of the rotor 10 .
[0095] In the gas coolant supplying step S 15 , the control unit 23 determines whether the temperature of the rotor 10 reaches the desired initial cooling temperature based on the date received through the initial coolant state sensor 25 .
[0096] When it is determined that the temperature of the rotor 10 reaches the desired initial cooling temperature, the control unit 23 outputs the driving signal to stop driving the pump 38 a and then, allows the gas coolant G including at least one of neon, hydrogen and helium to be supplied through the gas coolant supplying line 33 .
[0097] Thus, when the rotor 10 is initially cooled through liquid nitrogen, after the gas coolant G is supplied through the gas coolant supplying line 33 and condensed through the condenser 35 , the coolant is supplied into the cavity 17 by gravity so that the rotor 10 is cooled at the target temperature.
[0098] According to the exemplary embodiment of the present invention, it is configured in a natural circulation scheme or a compulsive circulation scheme to enable the coolant to be circulated, so that the coolant can be smoothly circulated even in state that the rotor is in a non-level state (i.e. not in a horizontal state).
[0099] According to the exemplary embodiment, the superconducting rotating machine is configured to actively circulate liquid nitrogen in the initial cooling of the rotating machine, so that the initial cooling time of the superconducting rotating machine can be reduced.
[0100] While exemplary embodiments have been particularly described above, it will be understood by those skilled in the art that various modifications, additions and substitutions in form and details may be made therein without departing from the scope and spirit of the inventive concept as defined by the following claims. | Provided are a superconducting rotating machine which improves the cooling efficiency of a rotor by using schemes of passively or actively circulating a coolant and a cooling method thereof. The superconducting rotating machine includes a rotor supported rotatably about a rotation axis and including: at least one superconductive coil; and a central cavity; and a cooling apparatus disposed at an exterior of the rotor and configured to communicate with the cavity, wherein the cooling apparatus includes: a condenser configured to condense a gas coolant supplied through a gas coolant supplying pipe to generate a condensed coolant; a coolant circulating unit configured to supply the condensed coolant into the cavity, configured to recover a vapor coolant evaporated in the cavity into the condenser and configured to circulate the condensed coolant; and a forced circulating unit configured to actively circulate the condensed coolant into the cavity in response to the rotor being tilted. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 12/276,990, filed Nov. 24, 2008, (issuing as U.S. Pat. No. 8,297,282 on Oct. 30, 2012), which was a non-provisional of U.S. Provisional Patent Application Ser. No. 60/989,889, filed Nov. 23, 2007. Both of these applications are incorporated herein by reference and priority to each is hereby claimed.
BACKGROUND
The term “hyperbaric” is used herein to mean a pressure greater than ambient, over and above the range of pressure variation encountered in the course of normal fluctuations in atmospheric pressure caused by changes in the weather. In one embodiment pressures between 1.2 and 1.6 atmospheres are contemplated. In various embodiments higher pressures can be used. In various embodiments lower pressures can be used.
A variety of acute, subacute and chronic conditions related to brief or prolonged exposure to altitude (or to decompression, in the case of divers and others working at elevated pressure) are nevertheless alleviated by treatment in a hyperbaric atmosphere.
In one embodiment is provided a hyperbaric training facility, providing an environment of elevated pressure. In one embodiment, the facility serves as an exercise environment, permitting an improved endurance training regimen. In another embodiment, the facility is adapted for the emergency treatment of various pressure changing sicknesses, such as “mountain sickness” or acute pulmonary edema.
In one embodiment is provided an exercise facility where training exercises at atmospheric pressures greater than normal pressure at sea level. This embodiment allows persons exercising at elevated pressures (compared to one atmosphere at sea level) regardless of the ambient exterior pressure.
Air-supported structures, tennis domes, radar domes and the like are distinguished from the devices of the present invention by the fact that only a minuscule increment of pressure is needed to maintain such structures in an inflated condition. For example, a pressure differential of only 70 mm water pressure is all that is required to maintain the rigidity of a radar dome of 15 meter diameter in winds up to 240 mph. In units of pounds per square inch (“psi”), 70 mm of water is approximately 0.1 lb/sq. inch, an amount within the range of normal atmospheric fluctuations due to weather conditions and not hyperbaric as herein defined. Examples of air-supported, but nonhyperbaric structures are shown by Dent, R. M., Principles of Pneumatic Architecture (1972), John Wiley & Sons, Inc., New York; by Riordan, U.S. Pat. No. 4,103,369; and by Jones III, U.S. Pat. No. 3,801,093.
Accordingly, it is desired to provide a hyperbaric exercise facility which overcomes the disadvantages of the prior art.
SUMMARY
In one embodiment, there is provided a hyperbaric enclosure for use by an individual for a beneficial health-related effect. In one embodiment, this enclosure can be in the form of a single piece dome which is seamless to avoid localization/enhancement of stresses.
In one embodiment, the facility is at least partially spherical/hemispherical which increases the ability to handle elevated interior pressures.
In one embodiment, the facility is relatively impermeable in order to maintain constant elevated pressure without substantial air leakage.
In one embodiment, the facility provides at least one airlock to allow entering and exiting of the interior without losing a substantial amount of interior pressure.
In one embodiment, the facility provides at least one double ended airlock the chamber that can remain pressurized indefinitely, eliminating cycling time and associated stresses with individuals entering and leaving interior.
In one embodiment, the facility is of a reinforced concrete construction.
In one embodiment, the facility is in the form of a concrete dome that is fireproof, providing safety for human occupants.
In one embodiment, the interior pressures can be provided by a compressor, blower, and/or bottled gasses.
In one embodiment, the facility is at least one pressure regulator to display and regulate internal pressure
In one embodiment, the facility provides at least one grade beam that is extended well below finished floor elevation and integrally tied to a thin-shell concrete dome with reinforcement material (rebar, rods, post-tensioning wire cable, mesh, fabric, etc) to eliminate local stresses at intersection of floor and dome shell.
In one embodiment, the apparatus features a grade beam that ensures structure integrity in the event of soil subsidence or seismic activity.
In one embodiment, the apparatus features a concrete floor that rests upon thickened section of grade beam to prevent downward thrust.
In one embodiment, the apparatus features optional post-tensioning cables, arranged latitudinally and longitudinally, and torqued to increased measured values. Cables can be used to bind a thin-shell concrete dome and foundation integrally together and making the chamber highly resistant to soil subsidence, earthquake, tornadoes, hurricanes.
In one embodiment, the apparatus features a half-sphere, post-tensioned concrete, double airlock shell with pressurization equipment (e.g. compressor) and a pressure regulator.
Various embodiments are adapted to achieve specific beneficial effects, including, but not limited to increased beneficial results from exercising at hyperbaric pressures, relief from altitude sickness, pulmonary edema, rapid decompression, and improved endurance conditioning for athletes.
In one embodiment is provided a spherical or near-spherical shell (along at least one axis of symmetry), construction of nonbreathable material (or semi-permeable material) for achieving and maintaining air (or other gas mixture) pressure inside the interior which can be adjustable from 0-10 lbs. per square inch greater than ambient, and preferably 0.2-10 lbs per square inch greater than ambient, and means for ingress and egress which can be closed to prevent air loss.
In one embodiment is provided geodesic construction (along at least one axis of symmetry), construction of nonbreathable or semi-permeable material for achieving and maintaining air (or other gas mixture) pressure inside the interior which can be adjustable from 0-10 lbs. per square inch greater than ambient, and preferably 0.2-10 lbs per square inch greater than ambient, and means for ingress and egress which can be closed to prevent air loss.
In one embodiment is provided constructions for achieving and maintaining air or other gas mixture pressure inside the chamber from 0.2 psi to 10 psi greater than ambient and in preferred embodiments the pressure is achieved and maintained in the range from 0.2 psi to 4 psi above ambient.
In one embodiment is provided a hyperbaric exercise training facility having a 40 to 1,000 foot diameter size, greater or lesser, made of a nonbreathable concrete material that can be pressurized to hyperbaric pressure using air pumping equipment such as an air compressor and/or blower. The air can be continuously circulated in the facility by simultaneously controlling the internal pressure by means of an inlet valve and an exhaust valve.
In one embodiment inside the training facility can be a gym, providing exercise equipment such as weight machines, treadmills, exercise bikes, free weights, rowing machines, ski machines, training equipment.
In one embodiment various control instruments can be added, such as a barometer, along with devices to measure heart rate, blood plasma oxygen levels, breathing rate or body temperature of the individuals using the exercise equipment.
In one embodiment these measurements can be remotely monitored using wireless devices and provided to data acquisition devices and to detect and react to key values.
In various embodiments, the hyperbaric exercise facility can be constructed to design standards of, and will receive from, the US Coast Guard a certification of PV-HO, designating a pressure vessel rated for human occupancy. There are no rigid domes in existence which have such a designation.
In one embodiment, the hyperbaric exercise facility is used for hyperbaric exercise training.
In one embodiment, the hyperbaric exercise facility is used for training and/or testing in the fields of military, aerospace, or diving. In various embodiments, the hyperbaric dome has a very high resistance to wind loads and seismic events, making an ideal catastrophe shelter for tornadoes, hurricanes, earthquakes.
In one embodiment, the hyperbaric exercise facility can be used for endurance conditioning by carrying out various exercise routines in a training regimen.
In one embodiment a maximum benefit can be obtained by exercising daily within the hyperbaric exercise facility exerciser for a sufficient period to elicit maximum cardiopulmonary performance.
In one embodiment one or more far infrared saunas are provided. These saunas can be used with various treatment schemes such as removal of various environmental toxins, deep tissue regeneration, and various other items.
In one embodiment the color temperature of lighting can be changed. In one embodiment this can be done on a programmed basis. In one embodiment a selection of a plurality of pre-programmed light and/or temperature scenarios can be provided. In one embodiment the selected scenario can be implemented during an exercise regime. In one embodiment the user can select an individual pre-programmed selections. In one embodiment the program varying in at least a plurality of ways the color temperature, and/or wavelength, and/or frequency.
In one embodiment is provided a hyperbaric exercise facility wherein the pressure inside the hyperbaric facility is increased from ambient pressure levels to allow more efficient athletic and fitness training, including cardiovascular training.
In one embodiment a hyperbaric dome is constructed of reinforced concrete material. The dome has means for ingress and egress which may be closed to provide an essentially air-tight seal. Means for pressurizing the dome and achieving an elevated pressure and valve means for controlling air pressure are provided. Optionally, means for scavenging excess moisture and carbon dioxide from the interior may be provided. Double airlocks allow for the change of occupants without the need to de-pressurize the dome.
In one embodiment is provided a catastrophe shelter for civil defense, homeland security, and military applications to protect occupants against natural and manmade catastrophes, terrorist attacks, environmental and climatalogical (including the ability to modify interior pressure variants to external barometric pressure), biological warfare agents, chemical warfare agents, and nuclear or radiological blasts and radioactive fallout. This embodiment can be provided with separate airlocks and separate air supplies for decontamination and quarantine, all with varying bariatric pressures user programmable upon requirements and from which access can be provided directly into chamber. Design parameters can be increased for added protection, such as increasing the thickness of the high performance concrete, together with specific types of reinforcements, to provide impact resistance.
A deformable and trimmable rigid emergency repair kit, typically made from metallic sheets or Kevlar, carbon, or graphite fibers, can be provided which can be rapidly deployed to prevent depressurization from bullet, shrapnel, or rocket penetrations. Anchored in place by quick setting epoxy or cements, followed by applying layers of quick-setting high performance cements, such as magnesium oxide, for a permanent or semi-permanent repair.
Air quality can be insured on the incoming process airstream used for pressurization by: high efficiency particulate filtration; adiabatic compression to rapidly increase the temperature to 600 degrees F. or greater, followed by a rapid decrease of pressure which serves to sterilize biologicals and cause molecular dissociation of volatile organic compounds. Plasma, either hot or cold but preferably cold can sterilize biologicals and cause molecular dissociation of volatile organic compounds when air is passed through the corona, (with enhanced effects if pure oxygen is introduced) generating mono-atomic allotropes of oxygen which is highly oxidative. Introducing hydrogen peroxide can be used to generate highly reactive hydroxyl ions, where the allotropic oxygen and hydroxyl ions may be blended, if desired, by user programmability. Ultraviolet radiation in the C-band, centering at or about 254 nm in wavelength can be employed.
Excess ions, both hydroxyl and ozone, as well as volatile organic compounds (VOC's), can be removed from the incoming and re-circulated airstreams by an activated carbon filter media affixed across the airstream. Impregnating the activated carbon with selected dopants, such as potassium iodide, can enhance the removal of high and low molecular weight VOC's.
The amount of ions in the air can be regulated using an automated system. The same methods can be utilized for insuring interior air quality as it is being re-circulated through climate control apparatus, either before or after. Self-contained living quarters can be provided with varying bariatric levels for short or long term length of stay.
Another embodiment of this invention is a closed circuit rebreather which includes the use of an oxygen source and carbon dioxide removal means. This allows the invention to be used without continuous pumping or other attention for a period of hours.
“Rebreather” means an embodiment of this invention which is large enough to hold a sufficient volume of air for a human to breathe during a period of time sufficient for an attendant to take care of necessary maintenance tasks other than air maintenance, preferably one-half hour or more. The rebreather must be substantially leak proof, and is large enough to contain a whole human body.
This closed-circuit breathing system supplies air, preferably not oxygen-enriched, at whatever pressure desired, for periods of time (preferably at least about six hours) depending on the amount of oxygen in the oxygen source and the capacity of the carbon dioxide removal means. This embodiment also dispenses with the need for constant monitoring and adjustment of oxygen flow. It is used preferably in mountain environments, but may also be used in any environment where an extended period must be spent in an enclosed space, such as underground or under water. In such environments, the preferred pressure to be maintained within the bubble is atmospheric pressure.
In this embodiment, an oxygen source, preferably a container of compressed oxygen, is connected to the interior of the chamber through a pressure regulator such that oxygen is bled into the chamber in response to a pressure drop below a preselected pressure. As the air inside the facility is breathed, oxygen is converted to carbon dioxide and exhaled into the facility. The carbon dioxide is then removed by the carbon dioxide removal means inside the facility. The original gas composition inside the facility can be any breathable mixture, including an enriched oxygen mixture.
The exerciser embodiment is intended to achieve the following goals: to provide a structure capable of maintaining in its interior an elevated pressures above ambient, allowing individuals to carry out fitness training using training equipment, and to provide an exercise method for athletes desiring maximal endurance conditioning.
While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and/or changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”
FIGURES
FIG. 1 is a perspective view of the preferred embodiment of the apparatus of the present invention in the form of a dome;
FIG. 2 is a perspective view of the preferred embodiment of the apparatus of the present invention showing an individual entering a dome through a double air lock system;
FIG. 3 is a perspective view of the preferred embodiment of the apparatus of the present invention showing an individual entering a dome through a double air lock system;
FIG. 4 is a perspective view of the preferred embodiment of the apparatus of the present invention showing an individual entering a dome through a double air lock system;
FIG. 5 is a partial top view of the preferred embodiment of the apparatus of the present invention showing the training floor;
FIG. 6 is a sectional side view of the preferred embodiment of the apparatus of the present invention schematically showing reinforcement in the dome, floor, and support ring portions;
FIG. 7 is a perspective view of the dome schematically showing both longitudinal and latitudinal reinforcement;
FIG. 8 is a sectional perspective view of the preferred embodiment of the apparatus of the present invention showing both longitudinal and latitudinal reinforcement;
FIG. 9 is a perspective view of the preferred embodiment of the apparatus of the present invention showing the supporting dome ring;
FIG. 10 is a top view of the ring;
FIG. 11 is a sectional view of the preferred embodiment of the apparatus of the present invention showing the connection between the dome and the support ring with interconnecting reinforcement;
FIG. 12 is another sectional view of the preferred embodiment of the apparatus of the present invention showing the dome and support ring with reinforcement;
FIG. 13 is a sectional view of the preferred embodiment of the apparatus of the present invention showing dome and support ring with reinforcement;
FIG. 14 is another section view of the preferred embodiment of the apparatus of the present invention showing dome and support ring with reinforcement;
FIG. 15 is a top schematic view of the preferred embodiment of the apparatus of the present invention for a multi-dome configuration;
FIG. 16 shows a cross section of the preferred embodiment of the apparatus of the present invention showing a parabolic shape where the maximum height is larger than the radius of the circular base;
FIG. 17 shows a cross section of the preferred embodiment of the apparatus of the present invention having a parabolic shape where the maximum height is smaller than the radius of the circular base;
FIG. 18 shows a dome cross section of semi-circular shape;
FIG. 19 shows a dome cross section having a shape with its radius of curvature varying at predefined rates;
FIG. 20 shows a sinusoidal function example of various inputs during therapy; and
FIG. 21 shows a composite function example of various inputs during therapy.
FIGS. 22 and 23 show two embodiments of a spherical dome.
DETAILED DESCRIPTION
The various embodiments herein described, as well as other embodiments constructed according to the teachings herein, have many structural features in common.
In one embodiment, a specially engineered and specially constructed dome is used for a hyperbaric chamber which can substantially increase the size of the confined space compared to a rectilinear or cylindrical format. The geometric increase in volume allows enough space to avoid being in a clinical situation and substantially reducing and/or eliminating claustrophobia which is a major objection to hyperbaric structures (such as that used for hyperbaric oxygen therapy). The economy of scale provided with this embodiment can substantially revolutionize the capacity and costs of construction and usage.
FIGS. 1 and 6 are views of a pressurized facility 10 in the shape of a dome 100 . Pressurized facility 10 can comprise dome 100 having interior 130 , front 150 , rear 140 , floor 200 , and support ring 20 . To pressurize interior 130 a pressurizing system 800 (which is described below) can be provided. A venting system 900 can also be provided. To enter and exit facility 10 an entrance 400 can be provided (see FIG. 2 ). Entrance 400 can comprise first side 410 , second side 420 , floor 440 , walls 450 , and interior 430 (between first and second sides 410 , 420 ).
On first side 410 can be door 460 which can open to the interior 430 of entrance 400 as schematically indicated by arrow 530 . Opening to interior 430 provides a fail safe mode as the pressure in interior 430 should consistently be greater than (or at least equal to) ambient pressure outside of entrance 400 . Around door 460 can be a sealing system as described below.
On second side 420 can be door 470 which can open to the interior 130 of dome 100 as schematically indicated by arrow 540 . Opening to interior 130 provides a fail safe mode as the pressure in interior 130 should consistently be greater than (or at least equal to) pressure of interior 430 of entrance 400 . Around door 470 can be a sealing system as described below.
In one embodiment a double air lock is used to resist excessive pressure loss to interior 130 of dome 100 when individuals enter and exit facility 10 . FIGS. 2 , 3 , and 4 are perspective views of the steps of an individual 405 entering a pressurized facility 10 as schematically indicated by arrow 500 through entrance 400 having a double air lock system (e.g., sealed doors 460 , 470 ).
In one embodiment equalization options are provided to the person 405 entering and/or exiting the double type air lock. The double type air lock can include first sealed lock, an interior space, and a second sealed lock. The first sealed lock can be the transition point between the outside and the interior space. The second sealed lock can be the transition point between the interior space and the interior of the hyperbaric facility.
The hyperbaric facility 10 will be at a higher pressure than the surrounding outside environment. Accordingly, it is preferred to have a system to reduce the transient pressure change when entering and exiting the hyperbaric facility. This can be done through increasing or decreasing relatively slowly the pressure in the interior space relative to the pressure the individual 405 will see when moving from the interior space to either the outside (outside pressure being assumed to be at 1 atmosphere which will be lower than the initial pressure of the interior space) or to the interior of the hyperbaric facility (which interior facility pressure will be higher than the pressure of the interior space) as schematically indicated by arrows 510 , 520 .
To avoid having the individual 405 see a sharp increase or decrease of pressure, a timed increase or decrease in the interior space is envisioned. This timed decrease of pressure can be obtained through slowly venting the interior space to the outside until the interior pressure equals that of the outside. This timed increase of pressure can be obtained by slowing venting interior pressure of the facility into the interior space until the pressure of the interior space equals the pressure of the interior of the facility. Possible venting systems can include properly sized orifice which can be opened and closed, for example using a valve (ball, gate, butterfly, etc.) where the individual 405 can open the valve to equalize the pressure and then close the valve.
In one embodiment, a pressurized exercise facility can be provided in apparatus 10 which includes dome 100 . FIG. 5 is a top view of the training floor 200 which can include various exercise equipment along with other facilities. For example, machines 250 (butterflies), 260 (pulls), 270 (leg press), 280 (leg curls), 290 (climber/stepper), 300 (treadmill), 310 (climber/stepper) and 320 (elliptical trainer) can be included. Additionally, free weight stations can be included along with other exercise equipment found in gyms. The training floor 200 can also be an oxygen station 370 that can be located in the center of the floor 200 .
In one embodiment there can be included a message center in interior 130 which includes at least one message table. In one embodiment a plurality of message centers are provided. In one embodiment each message center includes a plurality of message tables. In one embodiment one or more saunas 350 , 360 (e.g. infrared saunas) are provided. These saunas 350 , 360 can be used to various treatment schemes such as removal of various environmental toxins, deep tissue regeneration, and various other items.
Below will be described the construction of a typical dome 100 . Pressurized facility 10 can comprise dome 100 having interior 130 , floor 200 , and support ring 20 . FIG. 6 is a sectional side view of dome 100 schematically showing reinforcement in the dome 100 portion, top 110 portion, floor 200 portion, bottom 120 portion, and support ring 20 portion. FIG. 7 is a perspective view of dome 100 schematically showing both longitudinal 60 , 62 , 64 , 66 , and 68 and latitudinal 70 , 72 , 74 , 76 , and 78 reinforcement. FIG. 8 is a sectional perspective view of dome 100 (taken through FIG. 7 ) showing both longitudinal and latitudinal reinforcement. FIG. 9 is a top view of supporting dome ring 20 , having a top 30 and a bottom 40 . FIG. 10 is a perspective view of ring 20 .
Dome 100 can include a plurality of reinforcement, which can be both in a latitudinal direction along with a longitudinal direction. In one embodiment the reinforcement can be pre-tensioned. In one embodiment the reinforcement can be post tensioned. Support ring 20 can be connected to dome 100 by interlocking reinforcement. Interlocking should be developed to prevent dome portion 100 from being lifted up if its interior 130 pressure increases substantially above ambient pressure. In one embodiment floor 200 can be connected to dome 100 by interlocking reinforcement. In one embodiment floor 200 can be connected to support ring 20 by interlocking reinforcement. In one embodiment floor 200 can be connected to both dome 100 and support ring 20 by interlocking reinforcement.
FIG. 11 is a sectional view of the connection between dome 100 and support ring 20 with interconnecting reinforcement. FIG. 12 is another sectional view (exploded) of dome 100 and support ring 20 with reinforcement. Reinforcement shown includes 82, 82′, 80 , 80 ′, and 84 ′.
FIG. 13 is a sectional view of dome 100 and support ring 20 with reinforcement in the form of reinforcing bars or “rebar”. Support ring 20 includes horizontal rebars 90 , 92 , 94 , 96 , and 98 which can circumnavigate the extent of support ring 20 . Support ring 20 can also include a plurality of vertically connecting rebars 90 which can interconnect with rebars in floor 200 (via portion 80 ′). Plurality of vertically connecting rebars 90 can be symmetrically spaced about support ring 20 . Support ring 20 can also include a plurality of vertically connecting rebars 84 which can interconnect with rebars in dome 100 (via portion 84 ′). Plurality of vertically connecting rebars 84 can be symmetrically spaced about support ring 20 .
Dome 100 can include a plurality of longitudinal reinforcing bars or “rebars” 60 , 62 , 64 , 66 , 68 which circumnavigate dome 100 . These plurality of longitudinal rebars can be interconnected with plurality of vertical rebars 84 in support ring 20 . These plurality of longitudinal rebars can be interconnected with plurality of horizontal rebars 82 (via vertical portions 82 ′) in floor 200 . Plurality of horizontal rebars can be of a spoke formation and symmetrically spaced about floor 200 .
Dome 100 can also include a perimeter rib 124 . Floor 200 can also include a perimeter groove 204 . Perimeter rib 124 can fit inside perimeter groove 204 . In one embodiment dome 100 can be directly connected to support ring 20 . Support ring 20 could have perimeter groove 204 ′, and floor 200 can abut the interior of support ring 20 . However, even in this embodiment it is preferred that all three items (dome 100 , floor 200 , and support ring 20 ) be interconnected.
FIG. 14 is another section view of dome 100 and support ring 20 with reinforcement in the form of prestressed reinforcement. Although not shown for clarity, support ring 20 can includes horizontal reinforcement 90 , 92 , 94 , and 96 which can circumnavigate the extent of support ring 20 . This horizontal reinforcement can be post tensioned to reduce the tensile load on support ring 20 . Support ring 20 can also include a plurality of vertically connecting reinforcement 60 which can interconnect with reinforcement 80 ′ in floor 200 (via portion 80 ′). These reinforcement can be post tensioned reinforcement. Plurality of vertically connecting reinforcement 60 can be symmetrically spaced about support ring 20 . Support ring 20 can also include a plurality of vertically connecting reinforcement 60 ′ which can interconnect (or be one continuous piece of reinforcement) with reinforcement in dome 100 . Plurality of vertically connecting reinforcement 60 ′ can be symmetrically spaced about support ring 20 .
Dome 100 can include a plurality of longitudinal post tensioned reinforcement 60 , 62 , 64 , etc. which circumnavigate dome 100 . These plurality of longitudinal reinforcement can be interconnected with post tensioned reinforcement in support ring 20 . These plurality of post tensioned longitudinal reinforcement can be interconnected with plurality of post tensioned reinforcement in floor 200 . Plurality of horizontal post tensioned reinforcement can be of a spoke formation and symmetrically spaced about floor 200 .
Dome 100 can also include a perimeter rib 124 . Floor 200 can also include a perimeter groove 204 . Perimeter rib 124 can fit inside perimeter groove 204 . In one embodiment dome 100 can be directly connected to support ring 20 —here support ring 20 could have perimeter groove 204 ′, and floor 200 can abut the interior of support ring 20 . However, even in this embodiment it is preferred that all three items (dome 100 , floor 200 , and support ring 20 ) be interconnected.
Using a dome made of sprayed concrete or shotcrete can dramatically reduce the cost of constructing the hyperbaric facility. This also allows a dramatic increase in the overall size the dome over conventionally available hyperbaric chambers. For example, domes having diameters ranging between about 20 feet to 1000 feet in diameter can be used; more preferably between about 30 feet to 900 feet, more preferably between about 40 feet to 800 feet, more preferably between about 50 feet to 700 feet. Additionally, domes having diameters of at least about 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, and 1000 feet can be used. Alternatively, ranges of diameters of domes between about any of the two above specified diameters can be used.
In one embodiment the interior of the facility is maintained at a pressure of between about 1.2 to 2.4 atmospheres absolute of pressure in the interior to provide a hyperbaric situation (assuming 1.0 atm=14.7 psi at standard temperature at sea level); more preferably between about 1.2 to 2.0; more preferably between about 1.2 to 1.8; more preferably between about 1.2 to 1.6; more preferably between about 1.2 to 1.4, more preferably, between about 1.2 to 1.3; and most preferably about 1.3. Alternatively, ranges of pressures between about any of the two above specified pressures can be used. Alternatively, pressure can be maintained between about 1.3 to 1.4 atmospheres. Alternatively, pressures between about 1.4 to 2.4, more preferably between about 1.6 to 2.4, and more preferably between about 1.8 to 2.4. Alternatively, ranges of pressures between about any of the two above specified pressures can be used.
The hyperbaric chamber devices of the invention are designed to maintain pressure from 0-20 psi above ambient. In other embodiments the pressure range can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and/or 20 psi above ambient. Alternatively, ranges of pressures between about any of the two above specified pressures can be used.
FIG. 15 is a top schematic view of a multi-dome configuration for a pressurized facility. The multi-dome configuration can include domes 100 ′, 100 ″, and 100 ′″. Entrance 400 ′ can be attached to dome 100 ′. Entrance 400 ′ can be a double air lock with doors 460 ′ and 470 ′. Entrance 400 ″ can connect domes 100 ′ and 100″. Entrance 400 ″ can be a double air lock with doors 460 ″ and 470 ″. Entrance 400 ′″ can connect domes 100 ″ and 100 ′″. Entrance 400 ′″ can be a double air lock with doors 460 ′″ and 470 ′″. Each of the domes 100 ′, 100 ″, and 100 ′″ can include exercise facilities. In one embodiment different themes can be provided for each of the domes. For example, in dome 100 ′ exercise machines can be provided, while in dome 100 ″ saunas can be provided, while in dome 100 ′″ a rest and relaxation environment can be provided.
Although a semicircular shape is preferred for the dome (e.g., having a semicircular cross section and constant radius of curvature) embodying a hemisphere of a sphere, variations of the radius of curvature are envisioned. For example, a cross section of the dome can have the ratio of the radius of curvature (at an angle of inclination from the horizontal of 90 degrees) compared to the radius of curvature (at an angle of inclination from the horizontal of 0 degrees) varying between about 8/16 to 16/16; about 9/16 to 15/16, about 10/16 to 14/16, about 11/16 to 13/16, and 12/16. Alternatively, ranges between about any of the two above specified ratios can be used. For example, at a ratio of 8/16 the height of the dome (H) would be the one fourth of the length of the base (D).
As another example, a cross section of the dome can have the ratio of the radius of curvature (at an angle of inclination from the horizontal of 90 degrees) compared to the radius of curvature (at an angle of inclination from the horizontal of 0 degrees) varying between about 32/16 to 16/16; about 30/16 to 18/16, about 28/16 to 20/16, about 26/16 to 22/16, and 24/16. Alternatively, ranges between about any of the two above specified ratios can be used. For example, at a ratio of 24/16 the height of the dome (H) would be the same as the length of the base (D).
FIG. 16 shows a dome cross section 1000 having a parabolic shape with the maximum height of the top 1010 being larger than the radius of the circular base. Dome 1000 can have top 1010 , side 1030 , and bottom 1040 . At top 1010 is height 1020 . In this example height 1020 ( 2 R) is equal to the width of dome 1000 at bottom 1040 .
FIG. 17 shows a dome 1100 having a parabolic shape with the maximum height of the top 1110 being smaller than the radius of the circular base. Dome 1100 can have top 1110 , side 1130 , and bottom 1140 . At top 1110 is height 1120 . In this example height 1120 (½R) is equal to one fourth of the width of dome 1100 at bottom 1140 .
FIG. 18 shows a dome 1200 cross section having a semicircular shape. Dome 1200 can have top 1210 , side 1230 , and bottom 1240 . At top 1210 is height 1220 . In this example height 1220 (R) is equal to one half of the width of dome 1200 at bottom 1240 .
FIG. 19 shows a dome 1300 cross section having a shape with its radius of curvature varying at predefined rates—being a function of its angle Theta. Dome 1300 can have top 1310 , side 1330 , and bottom 1340 .
In one embodiment a tension ring can be provided at the base of the structure to resist/absorb expansive stresses of the dome.
In one embodiment, the interior of the facility includes an increased percentage of oxygen compared to ambient oxygen found at ambient pressures and sea level.
In one embodiment, as an alternative to increasing the percentage of oxygen in the interior (compared to ambient oxygen found at ambient pressures and sea level) the interior of the facility is provided with one or more high concentration oxygen sources. Enhanced O 2 can be provided to interior occupants and can be provided via hoses attached to hood, mask, nasal tubing, or canula delivering O 2 from bottles or oxygen concentrator, at pressures slightly, modestly, and/or highly elevated over internal chamber pressure.
In one embodiment aerobic exercise can be performed within chamber for enhanced oxygenation of tissues and detoxification of tissues.
Many suitable means for introducing air or gas mixtures to achieve a desired pressure are known in the art. The choice thereof will depend on the use to be made of the device, the volume of air to be delivered and the desired rate of circulation. Other considerations, such as temperature, humidity and noise level are also significant. For an exerciser, where a larger volume must be filled, an electric or gas-powered compressor can be used. Where a constant air flow at preset pressure is desired, a differential pressure gauge with an exhaust valve may be included. Other means, including supplying air or gas from a pressurized tank may be used, as will be understood by those of ordinary skill in the art. It will also be understood that positive displacement pumping means are required because fans, blowers and the like are not capable of providing the desired range of pressures.
The internal atmospheric composition can be controlled by means known to the art. As examples without any limitation of such means, known expedients for scavenging CO 2 and humidity may be employed, the capacity of such means being provided according to the intended use of the devices. The mountain bubble, enclosing a resting individual, can contain such CO 2 and humidity control as required using portable scavenging materials known in the art. The exerciser devices require larger capacities according to the needs of an exercising person. Alternatively, the exerciser can be provided with a sufficient flow of input air or gas mixture that the device is essentially continuously purged of excess CO 2 and humidity. Inasmuch as such means are peripheral to the basic devices, substitutions may be made as desired without the necessity of making major changes to the device itself, all within the scope of ordinary skill as presently known or later devised, according to the desired and intended function of the device.
Temperature can be controlled, where needed, by conventional means external to the devices themselves. In the exerciser, cooling is the more likely requirement accomplished, for example, by passing input air over the cooling coils of an air conditioning unit.
Entrances and exits to the dome can be designed to minimize any pressure loss to the interior of the facility when individuals enter and exit the facility. A double type air lock is envisioned. In one embodiment this double type air lock can comprise a pair of spaced apart hinged doors which open to the interior of the facility, the doors being placed in a pressure rated corridor. Preferably, each door swings open toward the interior of the facility. In one embodiment the doors can be automated where they automatically open and close. In one embodiment the doors can be manually opened and closed.
Each door can be pressure rated to the design pressure of the facility. Each door should have a seal around its perimeter where the interior pressure will push against the door and increase the effectiveness of the seal. One example seal can be foam rubber or neoprene rubber. In one embodiment at least one window is placed in each door. In one embodiment, an automatic lock can be activated where the interior pressure is below a set limit at least until the interior pressure raises to the specified limit. In one embodiment the lock is only on the outer door. In one embodiment a warning signal is made when the interior pressure is below a specified minimum so that the person attempting to open the door can decide whether to override the warning signal. In one embodiment the automatic lock can be overridden by the person opening the door.
In one embodiment equalization options are provided to the person entering and/or exiting the double type air lock. The double type air lock can include first sealed lock, an interior space, and a second sealed lock. The first sealed lock can be the transition point between the outside and the interior space. The second sealed lock can be the transition point between the interior space and the interior of the hyperbaric facility. The hyperbaric facility will be at a higher pressure than the outside. Accordingly, it is preferred to have a system to reduce the transient pressure change when entering and exiting the hyperbaric facility. This can be done through increasing or decreasing relatively slowly the pressure in the interior space relative to the pressure the individual will see when moving from the interior space to either the outside (outside pressure being assumed to be at 1 atmosphere which will be lower than the initial pressure of the interior space) or to the interior of the hyperbaric facility (which interior facility pressure will be higher than the pressure of the interior space). To avoid having the individual see a sharp increase or decrease of pressure, a timed increase or decrease in the interior space is envisioned. This timed decrease of pressure can be obtained through slowly venting the interior space to the outside until the interior pressure equals that of the outside. This timed increase of pressure can be obtained by slowing venting interior pressure of the facility into the interior space until the pressure of the interior space equals the pressure of the interior of the facility. Possible venting systems can include properly sized orifice which can be opened and closed (such as a valve—ball, gate, butterfly, etc.) where the individual can open the valve to equalize the pressure and then close the valve. An emergency pressure release can be provided.
Alternatively, the timed venting can be automated by using a plurality of sensors (at the outside, interior space, and interior of the facility), where automatic valves are used and the pressure equalized based on the differences in pressure sensed by the sensors. In one embodiment the timing of opening and closing the doors can be set by the user to open and close in a specified programmed time period.
Alternatively, the doors can be opened slowly to allow this slow venting process.
Alternatively, a second double air lock to the interior of the hyperbaric facility can be provided where one of the double air locks is specified as being the entrance, and the second of the double air locks is specified as being the exit.
In one embodiment, one or more of the doors can be a sliding door which slides open and closed. In the closed position the door seals with conventionally available seals. The sliding doors can be automated or can be manual.
In one embodiment the interior pressure of the hyperbaric facility is maintained at one of the specified levels in this application. The desired elevated pressures can be obtained through the use of one more pumps, compressors, and/or gas filled canisters. Where pumps are used, centrifugal, reciprocating, rotary, vane, piston, blower, screw, double screw, etc. types pumps can be used. Where compressors are, rotary, vane type, blowers, and/or piston type compressors can be used. Additionally, one or more blowers can be used.
One or more redundant systems to increase and/or maintain pressure can be used, such that where one of the primary pressure system fails, a redundant pressure system can be used to maintain the pressure of the interior of the hyperbaric facility.
In one embodiment one or more pressure sensors can be used to measure the interior pressure of the hyperbaric facility and the pressure system runs until the interior pressure reaches a specified minimum. In one embodiment the pressure will turn back on when the interior pressure falls below a specified level. In one embodiment the specified level to cut off the pressure is higher than the specified level to turn on the pressure. In one embodiment the pressure levels are the same.
In one embodiment where gas filled canisters are used. In one embodiment one or more pressure sensors can be used to measure the interior pressure of the hyperbaric facility and the canisters are opened until the interior pressure reaches a specified minimum. In one embodiment the canisters are again opened when the interior pressure falls below a specified level. In one embodiment the specified level to open the canisters is higher than the specified level to close the canisters. In one embodiment the pressure levels are the same.
In one embodiment one or more pressure regulators can be used to ensure that the interior pressure in the facility does not exceed a specified limit. If the pressure exceeds this specified level for whatever reason the regulator opens and bleeds off until a second specified lower limit is achieved.
In one embodiment the interior of the hyperbaric facility includes a climate control system. The climate control system maintains temperature and air quality. It can include conventionally available heating systems (such as steam, hot water, infrared, electric heating, etc.); conventionally available cooling systems, such as a chilled water and brine systems, absorption chillers, centrifugal chillers, cooling towers, and/or gas sorbent systems. Heat transfer can occur through either heated or cooled piping which moves the heated or cooled gases or fluids through the interior of the facility.
Air quality can be achieved and/or maintained by a bleeder valve system to flush “stale” air and/or carbon dioxide. In one embodiment includes conventionally available gas removal systems such as gas absorption systems and/or membrane separation systems. In one embodiment a sensor driven automated gas pressure swing absorption molecular sieve sorbents to selectively remove gases such as carbon dioxide.
In one embodiment one or more closed-circuit rebreathers can be used, such as that described herein and in U.S. Pat. No. 4,974,829, incorporated herein by reference. CO 2 produced by the users of the hyperbaric facility can be vented from the interior by means of one or more pressure relief valves. It is believed that continuous ventilation of the interior 42 liter/min, per person occupancy serves both to bring in fresh oxygen and vent out CO 2 , such that the O 2 concentration in the chamber never drops to below 20% and CO 2 never reaches a 1% level (2).
In one embodiment, higher CO2 levels of up to 7% can be user programmed to prevent blood vessel restriction resulting from hyperoxia and will initiate dilation of blood vessels, at which levels it is believed the bodies regulatory mechanisms allow more oxygen to cross the blood/brain barrier and thereby provide more oxygen directly to the brain, spinal cord, organs, and capillaries.
In one embodiment one or more closed-circuit rebreathers can be provided which can both remove the CO 2 from the exhalant and replace the O 2 consumed by the users of the facility. Such devices have been routinely used by divers, firemen and miners. In one embodiment a CO 2 scrubber can be used. The scrubber can include a series of one foot square pads that have been impregnated with LiOH. One pad has been determined to last on the order of 20 minutes. The pads function not only to remove the CO 2 but also the accumulated moisture. A Matheson, model 8-2, pressure regulator, full scale range 0 to 3 psi, was used to both maintain chamber pressure and to also replace the spent oxygen.
In one embodiment a humidity control system can be used. These can include cold coil and/or desiccant types and can control the latent heat to optimal levels, typically ranging from a low of 40% relative humidity (RH) to a high of 80% RH in order to effectuate various modalities of therapeutics. In one embodiment the humidity control system can be automated, such as a sensor control system, and which can be user programmable in a stepped interval across a diurnal cycle.
In one embodiment a system for removing volatile organic compounds from the interior of the hyperbaric facility can be used. These can include the use of various sorbent systems, such as an activated carbon system. Activated carbons can be used for the adsorption ofmany organic compounds from contaminated water and air streams. The adsorption process results from a physical attraction which holds molecules of the absorbate (e.g., stuff to be removed) at the surface of a solid by the surface tension of the solid.
In one embodiment an oxygen regulatory system can be used to regulate the concentration of oxygen. This can be the partial pressure of oxygen, or by weight or volume percent. The regulatory system can be automated through sensor and computer control. Oxygen can be added through various means such as pressurized gas canisters of pure and/or concentrated oxygen, sieve systems (e.g., molecular sieves), and/or membrane separation systems.
In one embodiment the oxygen level of the interior of the hyperbaric facility can be programmable as to level and timing. For example, the level content can be programmed to change over a set period of time and/or in a specified manner and/or pattern. For example, the oxygen level can follow a sinusoidal pattern, or a ramped pattern, or a stepped pattern over time so that when extra physical activities are performed extra oxygen can be available for such physical activities. This can be programmable over time and pattern, such as during set times during the day, or set days during the week. In one embodiment, the number of individuals occupying the interior can determine which of the available patterns will be selected. It is believed that varying the level of oxygen in different set patterns can increase the efficacy of exercising and/or physical activities performed in the interior of the facility. In one embodiment the level of oxygen in the interior can vary between a low of 21 percent to a high of 42 percent based on partial pressures.
FIG. 20 shows a sinusoidal function 2000 example of various inputs during therapy. Here, the oxygen level in the interior 130 of dome 100 can vary as set forth in function 200 . Alternatively, pressure can vary as set forth in function 2000 . An average value 2010 of the varying input can be maintained even though the transient value will change over time. In FIG. 20 the X axis measures time and the Y axis measures amount of the varied item (e.g., oxygen level, pressure, etc.). The varying input function has a lower value 2020 , wavelength 2040 , period 2050 . At selected times changes in activity can occur—e.g., at time 2110 exercise can begin where oxygen levels start increasing, at time 2120 exercise can be stopped. Alternatively, the function 2000 can be programmable for period 2050 , wavelength 2040 , amplitude 2030 , and average value 2010 by attendants of facility 10 , or by users of facility 10 .
FIG. 21 shows a composite function 2200 example of various inputs during therapy. Here, the function varying items in dome 100 can be a combination of more than one function 2300 (sinusoidal), 2400 (step), and 2500 (sinusoidal). Again, each one of the functions can be programmable for period, wavelength, amplitude, and average value.
Additionally, one or more oxygen outlets can be provided in the interior of the hyperbaric facility. The oxygen should be supplied through materials compatible therewith such as stainless steel, polymers, and/or other materials which do not substantially react with the oxygen. In one embodiment the level of oxygen can vary between a low of 21 percent to a high of 42 percent based on partial pressures.
In one embodiment even higher levels of oxygen (up to 100 percent) can be supplied to selected individuals through appropriate means, such as nasal tubes, masks, and/or hoods.
In one embodiment is provided a catastrophe shelter for civil defense, environmental and climatalogical disaster shelters (including the ability to modify interior pressure variants to external barometric pressure), homeland security, and military applications to protect occupants against terrorist attacks, biological warfare agents, chemical warfare agents, and nuclear or radiological blasts and radioactive fallout (NBC). This invention can be provided with separate airlocks and separate air supplies for decontamination and quarantine, all with varying bariatric pressures user programmable upon requirements and from which access can be provided directly into chamber. Design parameters can be increased for added protection, such as increasing the thickness of the high performance concrete, together with reinforcements. A deformable and trimmable rigid emergency repair kit, typically made from metallic sheets or Kevlar, carbon, or graphite fibers, can be provided which can be rapidly deployed to prevent depressurization from bullet, shrapnel, or rocket penetrations. Anchored in place by quick setting epoxy or cements, followed by applying layers of quick-setting high performance cements, such as magnesium oxide, for a permanent or semi-permament repair. Air quality can be insured on the incoming process airstream used for pressurization by: high efficiency particulate filtration; adiabatic compression (following the Ideal Gas Law, which states in part that when pressure increases temperature correlatively increases) to rapidly increase the temperature to 600 degrees F. or greater, followed by a rapid decrease of pressure which serves to sterilize biologicals and cause molecular dissociation of volatile organic compounds; plasma, either hot or cold, but preferably cold, which serves to sterilize biologicals and cause molecular dissociation of volatile organic compounds when air is passed through the corona, with enhanced effects if pure oxygen is introduced, generating mono-atomic allotropes of oxygen which is highly oxidative, or introducing hydrogen peroxide, which generates highly reactive hydroxyl ions, and where the allotropic oxygen and hydroxyl ions may be blended, if desired, by user programmability; and ultraviolet radiation in the C-band (UVC), centering at or about 254 nm in wavelength, which serves to sterilize biological organisms. Excess ions, both hydroxyl and ozone, as well as volatile organic compounds (VOC's), can be removed from the incoming and recirculated airstreams by means of an activated carbon filter media affixed across the airstream. Impregnating the activated carbon with selected dopants, such as potassium iodide, can enhance the removal of high and low molecular weight VOC's. The amount and types of ions in the air can be regulated using an automated sensor driven system.
In various embodiments the above described methods can be used for insuring interior air quality as it is being recirculated through climate control apparatus, either before or after. Self-contained living quarters can be provided with varying bariatric levels for short-term or long-term length of stay.
Construction
In various embodiments the shape of the dome can be formed from various materials, such as metal, pre-formed and pre-cast blocks made of expanded polystyrene foam (EPS) or cellular concrete, which is both lightweight and self-insulating, and can be continuously curvilinear or geodesic. These pre-formed building blocks or panels can be cemented and affixed into place. High strength and resistance to the expansive stress of interior pressure are easiest to achieve and most economical by spraying high performance blends of shotcrete over appropriate reinforcement, typically deformed iron rebar or post-tensioning cables arranged longitudinally and latitudinally. Since iron is magnetic, the utilization of iron rebar and/or cables for reinforcement in the dome envolope will generate a galvanic shell, or Ferriday Cage. Alternatively, non-magnetic reinforcements, such as bars or fibers made of basalt, glass, or polymers can be used to eliminate the galvanic shell.
The thickness of the shot-crete and the number, sizes, and types of reinforcement can be varied depending on desired usage. For use in military application, blast shields can be designed in increase impact resistance.
In one embodiment a reinforced concrete slab is poured, leaving a key-way joint. Pre-formed building blocks made of EPS or cellular concrete are cemented into place forming the shape of the dome. Deformed rebar and/or post-tensioning cables is suspended from the dome shell, then sprayed with consecutive thin layers of high performance concrete until built up to design thickness. Augments form the tunnels for the airlocks and are constructed in like manner. The exterior can then weatherproofed with an acrylic elastomeric coating.
In one embodiment the pre-formed, pre-cast building blocks are made of lightweight cellular concrete composed of magnesium phosphate, and which can optionally contain an admixture of cellulosic fibers.
In one embodiment the reinforcement is non-magnetic to eliminate the generation of a galvanic shell, or Ferriday Cage.
In one embodiment the pre-formed, pre-cast building blocks are made in a six-sided geodesic design, and can be made of various materials, including cellular concrete, magnesium phosphate, or EPS foam, are cemented into place forming the shape of the dome. Alternatively, the geodesic panels can be made of metal and welded into place, and can have an external reinforcing framework of a geometric design.
In one embodiment a reinforced concrete foundation is poured, leaving a keyway joint. A pre-lofted roofing membrane, such as polyvinyl chloride (PVC) or EDPM, is cemented to the perimeter for the foundation. Alternatively, a ring-beam can be poured and the remainder of the foundation poured at a later time. Vane-type blowers running continuously are used to inflate the roofing membrane which, when inflated, becomes an airform holding the shape of the dome and its augments. Closed-cell polyurethane foam insulation is sprayed onto the interior of the airform, rapidly hardening to form the permanent shape, at which time the blowers can be turned off. Alternatively, shot-crete, preferably with reinforcing fibers, can be sprayed onto the airform in thin, successive layers prior to the polyurethane foam, thus forming a hardened shell and which can be built up to application design thickness. Deformed rebar and/or post-tensioning cables is suspended from the dome shell, then sprayed with consecutive thin layers of high performance concrete until built up to design thickness. Augments form the tunnels for the airlocks and are constructed in like manner. The exterior can then additionally reinforced and sprayed with successive layers of shot-crete to reach design load. Additionally, the exterior can then weatherproofed with an acrylic elastomeric coating, if desired.
Alternate Embodiments
In one embodiment is provided a method and apparatus of using a hyperbaric facility comprising the steps of: (a) providing a hyperbaric dome, the dome including an interior and at least one double air lock for entering the interior; (b) increasing the pressure of the interior; and (c) a plurality of people entering the dome and excising.
In one embodiment the dome in comprises a dome, support ring, and floor, each of these components being structurally connected to each other by reinforcement.
In one embodiment the interior includes a plurality of exercise equipment including weight machines, treadmills, exercise bikes, free weights, rowing machines, ski machines, and training equipment. In one embodiment the interior includes at least one sauna. In one embodiment the sauna is an infra red sauna. In one embodiment the interior includes at least one oxygen supply which individuals can access for increasing the amount of oxygen breathed while in the dome.
In one embodiment is provided a method further comprising a second hyperbaric dome which is connected to the dome of step “a.” In one embodiment the interior pressure of the second dome is different than the interior pressure of the dome of step “a.” In one embodiment the domes are connected via a double air lock. In one embodiment is provided a method further comprising a third hyperbaric dome which is connected to the second dome. In one embodiment the three domes are connected via double air locks.
In one embodiment a cross section through one or more domes has the shape of a parabola. In one embodiment a cross section through one or more of the domes has the shape of an ellipse. In one embodiment the radius of curvature of one or more of the domes varies depending on the angular orientation from the floor.
In one embodiment one or more of the domes has a diameter between about 20 and about 1000 feet. In one embodiment the dome has a diameter between about 30 and about 900 feet. In one embodiment the dome has a diameter between about 40 and about 800 feet. In one embodiment the dome has a diameter between about 50 and about 700 feet. In one embodiment the dome has a diameter of at least about 75 feet. In one embodiment the dome has a diameter of at least about 100 feet. In one embodiment dome has a diameter of at least about 150 feet. In one embodiment the dome has a diameter of at least about 200 feet. In one embodiment the dome has a diameter of at least about 250 feet. In one embodiment the dome has a diameter of at least about 500 feet. In one embodiment the dome has a diameter of at least about 750 feet In one embodiment the dome has a diameter of at least about 1000 feet.
In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 2.4 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 2.0 atmospheres In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.8 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.6 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.5 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.3 atmospheres. In one embodiment the pressure of the interior is maintained between about 2 psi and about 20 psi above ambient pressure In one embodiment the pressure of the interior is maintained between about 3 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 4 psi and about 20 psi above ambient pressure In one embodiment the pressure of the interior is maintained between about 5 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 6 psi and about 20 psi above ambient pressure In one embodiment the pressure of the interior is maintained between about 7 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 8 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 9 psi and about 20 psi above ambient pressure In one embodiment the pressure of the interior is maintained between about 10 psi and about 20 psi above ambient pressure.
In one embodiment the interior of one or more of the domes includes a plurality of devices for measuring heart rate, breathing rate and body temperature of individuals inside the dome.
In one embodiment is provided a method and apparatus for using a hyperbaric facility comprising the steps of: (a) providing a hyperbaric dome, the dome including an interior, a support ring, and floor, wherein each of these components are structurally connected to each other by reinforcement bars; (b) increasing the pressure of the interior; and (c) a plurality of people entering the dome and excising.
In one embodiment the interior of one or more of the domes includes a plurality of exercise equipment including weight machines, treadmills, exercise bikes, free weights, rowing machines, ski machines, and training equipment In one embodiment the interior includes at least one sauna. In one embodiment the sauna is an infra red sauna. In one embodiment the interior includes at least one oxygen supply which individuals can access for increasing the amount of oxygen breathed while in the dome.
In one embodiment the method and apparatus further comprises a second hyperbaric dome which is connected to the dome of step “a.” In one embodiment the interior pressure of the second dome is different than the interior pressure of the dome of step “a.” In one embodiment the domes are connected via a double air lock. In one embodiment the method and apparatus further comprises a third hyperbaric dome which is connected to the second dome. In one embodiment the domes are connected via a double air lock. In one embodiment a cross section through at least one of the domes has the shape of a parabola. In one embodiment a cross section through the dome has the shape of an ellipse.
In one embodiment the radius of curvature of at least one of the domes varies depending on the angular orientation from the floor In one embodiment the dome has a diameter between about 20 and about 1000 feet. In one embodiment the dome has a diameter between about 30 and about 900 feet. In one embodiment the dome has a diameter between about 40 and about 800 feet. In one embodiment the dome has a diameter between about 50 and about 700 feet. In one embodiment the dome has a diameter of at least about 75 feet. In one embodiment wherein the dome has a diameter of at least about 100 feet. In one embodiment the dome has a diameter of at least about 150 feet. In one embodiment the dome has a diameter of at least about 200 feet. In one embodiment the dome has a diameter of at least about 250 feet. In one embodiment dome has a diameter of at least about 500 feet. In one embodiment the dome has a diameter of at least about 750 feet. In one embodiment dome has a diameter of at least about 1000 feet.
In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 2.4 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 2.0 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.8 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.6 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.5 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.3 atmospheres. In one embodiment the pressure of the interior is maintained between about 2 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 3 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 4 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 5 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 6 psi and about 20 psi above ambient pressure. In one embodiment pressure of the interior is maintained between about 7 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 8 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 9 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 10 psi and about 20 psi above ambient pressure.
In one embodiment the interior of the dome includes a plurality of devices for measuring heart rate, breathing rate and body temperature of individuals inside the dome.
In one embodiment is provided a method and apparatus for using a hyperbaric facility comprising the steps of: (a) providing a plurality of hyperbaric domes interconnected to each other; (b) increasing the pressure of the interior; and (c) a plurality of people entering the dome and excising. In one embodiment wherein there are two domes In one embodiment there are three domes. In one embodiment there are more than three domes. In one embodiment each dome includes an interior, a support ring, and floor, wherein each of these components are structurally connected to each other by reinforcement bars.
In one embodiment the interiors of the domes each include a plurality of exercise equipment including weight machines, treadmills, exercise bikes, free weights, rowing machines, ski machines, and training equipment. In one embodiment the interior includes at least one sauna. In one embodiment the sauna is an infra red sauna. In one embodiment the interior includes at least one oxygen supply which individuals can access for increasing the amount of oxygen breathed while in the dome.
In one embodiment further comprising a second hyperbaric dome which is connected to the dome of step “a.” In one embodiment wherein the interior pressure of the second dome is different than the interior pressure of the dome of step “a.” In one embodiment the domes are connected via a double air lock. In one embodiment the method and apparatus includes a third hyperbaric dome which is connected to the second dome. In one embodiment the domes are connected via a double air lock. In one embodiment at least one of the domes includes a cross section through the dome having the shape of a parabola. In one embodiment a cross section through the dome has the shape of an ellipse. In one embodiment the radius of curvature of the dome varies depending on the angular orientation from the floor.
In one embodiment the dome has a diameter between about 20 and about 1000 feet. In one embodiment the dome has a diameter between about 30 and about 900 feet. In one embodiment the dome has a diameter between about 40 and about 800 feet. In one embodiment the dome has a diameter between about 50 and about 700 feet. In one embodiment the dome has a diameter of at least about 75 feet. In one embodiment the dome has a diameter of at least about 100 feet. In one embodiment the dome has a diameter of at least about 150 feet. In one embodiment the dome has a diameter of at least about 200 feet. In one embodiment the dome has a diameter of at least about 250 feet. In one embodiment the dome has a diameter of at least about 500 feet. In one embodiment the dome has a diameter of at least about 750 feet. In one embodiment the dome has a diameter of at least about 1000 feet.
In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 2.4 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 2.0 atmospheres.
In one embodiment wherein the pressure of the interior of the dome is maintained between about 1.2 and about 1.8 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.6 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.5 atmospheres. In one embodiment the pressure of the interior of the dome is maintained between about 1.2 and about 1.3 atmospheres. In one embodiment the pressure of the interior is maintained between about 2 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 3 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 4 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 5 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 6 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 7 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 8 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 9 psi and about 20 psi above ambient pressure. In one embodiment the pressure of the interior is maintained between about 10 psi and about 20 psi above ambient pressure.
In one embodiment the interior of the dome includes a plurality of devices for measuring heart rate, PO2, breathing rate and body temperature of individuals inside the dome.
In one embodiment the dome does not have to be de-pressurized to facilitate the change of occupants.
In one embodiment the dome is a catastrophe, civil defense, homeland security, or military shelter.
In one embodiment the dome and its apparatus protects its occupants against natural or man-made disasters, including but not limited to: climatalogical, radiological, epidemics, pandemic disease, earthquake, tornado, and hurricane.
In one embodiment the dome and its apparatus protects against nuclear, radiological, biological, or chemical warfare agents.
FIGS. 22 and 23 show embodiments of a spherical dome. In one embodiment at least a portion of one or more of the domes extends below the ground surface and maintains a domelike shape below the ground surface.
In various embodiments the dome can be a complete sphere with at least part of the sphere extending below the ground surface. In one embodiment the following percentages of a diameter can extend below the ground surface: about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent. In various embodiments a range of between about any two of the specified percentages can be used.
In various embodiments the dome can be a partially complete sphere with at least part of the partially complete sphere extending below the ground surface. Here a horizontal plane cutting off the dome can be used to make the floor surface. In one embodiment the horizontal plane intersects the dome at the following radial percentage: about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent. In various embodiments a range of intersection of between about any two of the specified percentages can be used. In one embodiment the intersecting plane forms the floor of the dome and the floor is located below a ground surface. In one embodiment the following percentages of the radius can be used to provide the underground location the intersecting plane or flow below the ground surface: about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent. In various embodiments a range of between about any two of the specified percentages can be used.
In various embodiments the dome actually increases in size when below the ground surface (or a horizontal great circle of the dome is located below the ground surface). In one embodiment the horizontal great circle is located at the following radial percentage: about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 percent. In various embodiments a range of intersection of between about any two of the specified percentages can be used.
The following is a list of reference numerals:
LIST FOR REFERENCE NUMERALS
(Reference No.)
(Description)
10
apparatus/facility
20
support ring
30
top
40
bottom
50
length
60
reinforcement
62
reinforcement
64
reinforcement
66
reinforcement
68
reinforcement
70
reinforcement
72
reinforcement
74
reinforcement
76
reinforcement
78
reinforcement
80
reinforcement
82
reinforcement
84
reinforcement
86
reinforcement
88
reinforcement
90
reinforcement
92
reinforcement
94
reinforcement
96
reinforcement
98
reinforcement
100
dome
110
top
120
bottom
124
perimeter rib
130
interior
140
thickness
150
front
160
rear
170
inlet
200
floor
204
perimeter groove
210
exercise portion
220
first area
230
second area
240
third area
250
machine
260
machine
270
machine
280
machine
290
machine
300
machine
310
machine
320
machine
350
sauna
360
sauna
370
oxygen station
400
entrance
405
person/individual
410
first side
420
second side
430
interior
440
floor
450
walls
460
door
470
door
490
arrow
500
arrow
510
arrow
530
arrow
540
arrow
800
pressurizing system
900
venting system
1000
dome geometry
1010
highest point/top
1020
distance to highest point/top
1030
side
1040
base
1100
dome geometry
1110
highest point/top
1120
distance to highest point/top
1130
side
1140
base
1200
dome geometry
1210
highest point/top
1220
distance to highest point/top
1230
side
1240
base
1300
dome geometry
1310
highest point/top
1320
distance to highest point/top
1330
side
1340
base
2000
function
2010
average value
2020
lower value
2030
amplitude
2040
wavelength
2050
period
2100
change in activity point
2110
change in activity point
2120
change in activity point
2200
composite function
2300
first function
2400
second function
2500
third function
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A hyperbaric exercise facility is provided allowing a persons to perform exercises and other activities at increased pressures along with controlled levels of oxygen. Additionally, a catastrophe shelter is provided to protect its occupants from peril. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This disclosure relates to controlling transportation of data packets, and in particular, but not exclusively, to control of data packets via a node provided with a filtering function.
2. Description of the Related Art
A communication system can be seen as a facility that enables communication sessions between two or more entities such as user equipment and/or other nodes associated with the system. Establishment of a communication session enables a user to be provided with various services. The communication may comprise, for example, communication of voice, video or other audio and/or image data, multimedia or any other data. A session may, for example, comprise a two-way telephone call or multi-way conference session or connection between a user equipment and an application server (AS), such as a service provider server or a proxy.
A communication system typically operates in accordance with a given standard or specification which sets out what the various entities associated with the communication system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment is provided with a circuit switched service and/or a packet switched service. Communication protocols and/or parameters which shall be used for the connection may also be defined. In other words, a specific set of “rules” on which the communication can be based on needs to be defined to enable communication by means of the system.
Signalling is an example of functions that is commonly defined in an appropriate communication protocol or protocols. Signalling between various entities associated with a communication session is typically required in order to control the communication session. Control is typically required for the set-up of the communication session and also later on during communication on the established communication session.
The communication may be provided by fixed line and/or wireless communication interfaces. Examples of fixed line systems include a public switched telephone network (PSTN), a local area network (LAN) and any other data network provided by means of fixed connections between the nodes thereof. The wireless communication may be provided, for example, by means of a mobile communication system or wireless local area networks (WLANs). Mobile communication systems refers generally to any telecommunications systems which enable a wireless communication when users are moving within the service area of the system. An example of a typical mobile communication system is a Public Land Mobile Network (PLMN).
The mobile communications network can provide an access network providing a user with a wireless access to external networks, hosts, or services offered by specific service providers. The user may need to have a subscribership with the mobile communications system in order to be able to use the services of the mobile system. The mobile subscription information of the subscriber may indicate parameters such as parameters regarding the quality of service (QoS) the subscriber is entitled to receive, priorities, service restrictions, security, authentications, and so on.
An access point or gateway node of the mobile communication network provides further access to an external network or an external host. For example, if the requested service is provided by a service provider located in another network, the service request is routed via a gateway to the other network and the service provider.
Various user equipment (UE) such as computers (fixed or portable), mobile telephones and other mobile stations, personal data assistants or organizers, and so on may be used for accessing packet switched services. Mobile user equipment, typically referred to as a mobile station (MS), can be defined as a means that is capable of communication via a wireless interface with another device such as a base station of a mobile telecommunication network or any other station. The increasing popularity of Third Generation (3G) communication systems will, in all likelihood, significantly increase the possibilities for accessing services on the packet data networks via mobile user equipment (UE) as well as other types of UE.
The term “service” used above and hereinafter will generally be understood to broadly cover any service or goods which a user may desire, require or be provided with. The term also will generally be understood to cover the provision of complementary services. In particular, but not exclusively, the term “service” will be understood to include browsing, downloading, email, streaming services, Internet Protocol (IP) multimedia (IM) services, conferencing, telephony, gaming, rich call, presence, e-commerce and messaging, for example, instant messaging.
A more detailed example of a wireless packet switched communication system will now be described with reference to general packet radio service (GPRS). The GPRS operational environment comprises one or more subnetwork service areas, which are interconnected by a GPRS backbone network. Each subnetwork may comprise a number of packet data service nodes (SN). In this specification the service nodes will be referred to as serving GPRS support nodes (SGSN). Each of the SGSNs is connected to radio networks, typically to base station systems and/or radio access networks by way of base station controllers (BSC) and/or radio network controllers (RNC) in such a way that they can provide a packet service for mobile user equipment via several base stations. The intermediate mobile communication network provides packet-switched data transmission between a support node and mobile user equipment. The subnetworks are in turn connected to an external data network, e.g. to a packet data network (PDN), via GPRS gateway support nodes (GGSN). The GPRS thus allow transmission of packet data between mobile user equipment and external data networks.
A packet data protocol (PDP) context may be established to carry traffic flows over the packet switched communication system. A PDP context typically includes a radio access bearer provided between the user equipment, the radio network controller and the SGSN, and switched packet data channels provided between the serving GPRS service node (SGSN) and the gateway GPRS service node (GGSN). A session between the user equipment and other party would then be carried on the established PDP context. A PDP context can carry more than one traffic flow, but all traffic flows within one particular PDP context are treated the same way as regards their transmission across the network. This requirement regarding the similar treatment is based on PDP context treatment attributes associated with the traffic flows. These attributes may comprise, for example, quality of service and/or charging and/or filtering attributes. From the above mentioned functions filtering generally refers to operations wherein it is checked if the address information in the data packet matches a filtering criteria. If a data packet passes the filter, the packet is allowed to be forwarded to a next router. If a data packet does not meet the predefined criteria, it is commonly dropped.
A policy controller entity, for example a policy decision function (PDF), can be provided for controlling the transport layer of a PDP context. The policy decision function (PDF) may be provided by any appropriate controller entity. The PDF and GGSN are commonly arranged to communicate information to enable co-operation between the GPRS bearer level and the IMS level of the communication system. The PDF may be used for storing attributes for the purposes of functions such as the Quality of Service, filtering of data packet in the GGSN and so on.
An IP Multimedia Service (IMS) session related set of binding information generated by a policy decision function (PDF) and sent via the user equipment, to the GGSN can be used to verify that the PDP context operations requested by the user equipment comply with the preceding negotiation on the IMS level during the set-up or modification of the PDP context. As a result of the verification, the PDF authorizes QoS parameters for the GGSN. The authorized parameters sent by the PDF to the GGSN may include, among other things, filter parameters known as Packet Classifiers. Packet Classifiers can be used by the GGSN to filter the user plane traffic, both uplink and downlink, in the relevant PDP context. Packet Classifier parameters are commonly derived from signalling, for example from SDP/SIP (Session Description Protocol/Session Initiation Protocol) signalling. Packet Classifiers may employ information about source address, source port, destination address, destination port and protocol.
When a user equipment sending data packets defines a route through the network, for example by using the Internet Protocol version 6 (IPv6) Routing Header, the user equipment may define additional routing information. For example, the sending user equipment may indicate a specific route that the data packets shall follow when communicated over the network. To implement this, it is possible to define the destination address in each data packet at the time of sending thereof such that the destination address of the data packet is the address of the next router in the selected route, and not the actual i.e. final destination address.
However, typically the filtering criteria is based on the address of the final destination. Thus the filtering criteria used by a Packet Classifier or any other appropriate filtering mechanism used by a node may not be based on the address of the next node but is instead based on the final destination address. That is, the filtering function of a node is not necessarily made aware that the destination address assigned for a data packet by a user equipment or a previous node is not the final destination address of that data packet. Thus the node would still apply a filtering criteria that is based on the final destination address on that data packet. As a result of this the filtering process may drop the packets because they do not match the filtering criteria. Thus the transmission of packets may fail.
SUMMARY OF THE INVENTION
Embodiments of the present invention aim to address the problems associated with the use of non-matching filtering criteria.
According to one embodiment there is provided a method for transport control in a packet switched communication system. The method comprises receiving in a node a data packet assigned with a destination address and detecting that the destination address does not meet a filtering criteria. It is then checked if at least one further destination address has been assigned for the data packet. If it is found that at least one further destination address is assigned for the data packet, the filtering criteria is applied to the at least one further destination address. The data packet is forwarded from the node to a next node in response to detection that the data packet is assigned with a further destination address that meets the filtering criteria.
According to another embodiment there is provided a node for a packet switched communication system. The node comprises an input for receiving data packets assigned with at least one destination address and an output for forwarding data packets to another node based on the destination address. Control means for checking if at least one additional destination address has been assigned for a data packet and a filter for filtering destination addresses of received data packets are also provided. The configuration of the node is such that a data packet whose destination address does not meet a filtering criteria is nevertheless forwarded from the node if it is detected that the data packet is assigned with an additional destination address that meets the filtering criteria.
According to yet another embodiment there is provided a communication system provided with a node as described above.
The embodiments may provide a solution wherein an intermediate node, for example a gateway or another router does not drop a data packet even if an address checked based on a filtering criteria does not meet the filtering criteria. A more specific embodiment provides improved compatibility between data packet routing methods allowing changing destination addresses and a policy control function that is based on a final destination address or other one address. In some embodiments filter criteria of an intermediate router is updated to take into account the changed address.
BRIEF DESCRIPTION OF THE DRAWINGS
For better understanding of the present invention, reference will now be made by way of example to the accompanying drawings in which:
FIG. 1 shows schematically a communication system wherein the present invention may be embodied; and
FIGS. 2 and 3 are flowcharts illustrating operation of two embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a communication system suitable for embodying the present invention. More particularly, certain embodiments of the present invention will be described by way of example, with reference to the architecture of a third generation (3G) mobile communications system of FIG. 1 . However, it will be understood that the invention may be applied to any other suitable form of packet switched network.
FIG. 1 shows a mobile user equipment 30 . The basic operational principles of a mobile user equipment, that may also be referenced to as a mobile station, are generally known by those skilled person. A mobile user equipment is normally configured for wireless communication with other stations, typically with the base stations of a mobile communication system for enabling mobility thereof. A mobile user equipment may include an antenna element for wirelessly receiving and/or transmitting signals from and/or to the base stations of the mobile communication system. A mobile user equipment may also be provided with a display for displaying images and/or other graphical information for the user of the mobile user equipment. Speaker means are also typically provided. The operation of the mobile user equipment may be controlled by means of an appropriate user interface, such as control buttons, voice commands and so on. Furthermore, a mobile user equipment is typically provided with a processor entity and/or a memory means. The memory means, or other types of computer readable medium, may include computer code, including program code or instructions, configured to execute on the processor entity, or other computer-based devices, procedures such as a method for transport control in a packet switched communication system, as more particularly described herein. Communication between the user equipment and the entities of the communication network may be based on any appropriate communication protocol. A user may use the mobile user equipment for tasks such as, but not limited to, for making and receiving phone calls, for receiving and sending data from and to the network and for experiencing, for example, multimedia content by means of PDP contexts. For example, a user may access the network by means of a Personal Computer (PC), Personal Data Assistant (PDA), mobile station (MS) and so on.
A mobile communication system, in turn, may logically be divided between a radio access network (RAN) and a core network (CN). In the simplified presentation of FIG. 1 , the base station 32 belongs to the radio access network. It shall be appreciated that, although, for clarity, FIG. 1 shows the base station of only one radio access network, a typical communication network system usually includes a number of radio access networks. It shall also be understood that the mobile communication system 31 of FIG. 1 may be arranged to serve a plurality of mobile user equipment 30 .
The 3G radio access network (RAN) is typically connected to an appropriate core network entity or entities such as, but not limited to, a serving general packet radio service support node (SGSN) 34 . A subscriber information database entity 36 for storing information associated with the subscriber of the user equipment 30 is also shown. The HLR may contain various records 38 associated with the subscriber, such as details of PDP context subscriptions of the subscriber.
A user equipment within the radio access network may communicate with a radio network controller via radio network channels which are typically referred to as radio bearers (RB). These radio network channels may be set up in a mobile communication system in a known manner. Each user equipment 30 may have one or more radio network channels open at any one time with the radio network controller. The radio access network controller is in communication with the serving GPRS support node 34 via an appropriate interface, for example on an Iu interface.
The serving GPRS support node 34 , in turn, typically communicates with a gateway GPRS support node 40 via the GPRS backbone network on interface 39 . This interface is commonly a switched packet data interface. The serving GPRS support node (SGSN) 34 and/or the gateway GPRS support node (GGSN) 40 are for provision of support for GPRS services in the network. The exemplifying GGSN 40 of FIG. 1 is shown to be provided with a filter means 41 and a controller 42 configured to control the operation of the node in accordance with the principles of the invention.
Overall communication between user equipment 30 in the access entity and the gateway GPRS support node 40 is generally provided by a packet data protocol (PDP) context. Each PDP context usually provides a communication pathway between a particular user equipment and the gateway GPRS support node 40 . Once established, a PDP context may carry multiple flows. Each flow normally represents, for example, a particular service and/or a component of a particular service. The PDP context therefore often represents a logical communication pathway for one or more flows across the network. To implement the PDP context between user equipment 30 and the serving GPRS support node 40 , radio access bearers (RAB) are usually established which commonly allow for data transfer for the user equipment. The implementation of these logical and physical channels is known to those skilled in the art and is therefore not discussed further herein.
The user equipment may connect, via the GPRS network, to servers that are generally connected to an external packet data network, for example to an Internet Protocol (IP) network.
FIG. 1 shows a policy controlling entity, hereinafter referred to as the policy decision function (PDF) 44 . The policy decision function (PDF) 44 may be provided by an appropriate controller entity. The policy decision function may be provided with an appropriate database 46 for storing information required by the policy control operations. A non-limiting example for the appropriate controller is an Internet Protocol Session Control (IPSC) entity.
A session related set of binding information may be generated by the policy decision function (PDF) 44 and sent via the user equipment to the GGSN 40 for use in checking that the PDP context operations requested by the user equipment 30 comply with the preceding negotiation on the IMS level. As a result of the verification, the PDF 44 authorizes QoS parameters for the GGSN 40 .
The authorized parameters sent by the PDF 44 to the GGSN 40 may include, among other things, appropriate filtering criteria. For example, Packet Classifiers may be provided for the gateway 40 . Packet Classifiers may be based on information about source address, source port, destination address, destination port and protocol. As explained above, the Packet Classifiers can be used by the GGSN 40 to filter the user plane traffic, both uplink and downlink, in the relevant PDP context.
The user equipment 30 sending data packets may define a route through the network, for example by including additional routing information in a routing header of a packet. An example of the routing headers is the IPv6 (Internet Protocol version 6) Routing Header. The routing header enables definition of a specific route the packet shall take to reach the final destination. The routing header may consist of router addresses that are swapped with the destination address of the packet, one by one on each hop, until the packet reaches its final destination. At sending, the destination address in the packet is the address of the first router in the wanted route. Thus the destination address in each packet may be the address of the next router in the selected route, this address being changed in each router.
Because of the changing destination addresses the filter address used by the Packet Classifier as filtering criteria may not match with the destination address of the packet. The following describes with reference also to FIGS. 2 and 3 some exemplifying embodiments how to avoid dropping of packets because the destination address thereof does not match the filter parameters.
In accordance with an embodiment shown in FIG. 2 , when the GGSN 40 receives at step 100 an IPv6 packet on a policy controlled PDP context from the user equipment 30 , the filter function 41 thereof may check if the destination address in the packet matches with a predefined filtering criteria. The GGSN 40 may find out at step 102 that the destination address in the data packet does not match the filtering criteria, for example, a destination address or a range of addresses of the uplink filter parameters. If so, the controller 42 of the GGSN may scan the extension headers of the data packet at step 106 to find out if the packet is provided with a routing header. The scanning may be accomplished e.g. by checking the next header fields of the packet.
If a routing header is found from the packet, the GGSN 40 looks for the final destination address from the routing header. This may be accomplished e.g. by employing parameters such as the ‘Header Extension Length’ and ‘Segments Left’. If the final destination address is found, the filter is applied thereto at steps 110 , 112 and it is checked if the final destination address matches the destination address (or range of addresses) of the uplink filter parameters.
If there is no match, the GGSN may discard the packet. The GGSN may inform the sender by sending an appropriate message informing the receiver thereof that the destination is unreachable.
If the addresses match, the GGSN sends the packet forward, see step 114 .
FIG. 2 shows also a further possible embodiment in which the operation is looped such that even if the second address checked does not match the filter at step 112 , the controller looks for further possible addresses, thus in practice returning to step 110 . In accordance with this embodiment the packet is only dropped at step 118 when it has become clear that no such address can be found from the data packet that matches the filtering criteria.
It shall be appreciated that the loop between steps 116 and 110 is not always necessary, or even preferred. As shown in FIG. 3 , the data packet may be dropped at step 118 after the first further destination address or a limited number of addresses has been checked at step 112 .
In accordance with an embodiment shown in FIG. 3 it is possible for the GGSN to update the filtering criteria at step 120 . For example, the controller 42 may be configured to add the destination address of a data packet, i.e. the address of the next router in the selected route, which has passed the filter in step 112 , to the destination address filter parameters of the uplink Packet Classifier filter. By means of this subsequent data packets sent by the user equipment 30 in the same PDP context with the same routing information will pass the filter function of GGSN 40 based on commonly used screening techniques without any further checks, i.e. without steps 106 to 112 of FIG. 3 .
The updatable filtering criteria enables a user to start a session with one routing header and then change the routing header to another while keeping the first address the same. It is acknowledged that this might tempt a fraudulent user to try to pass data packets through the packet filter such that at least one of the remaining addresses of the subsequent packets is different from that of the first packet. The different addresses might be used to route the data packets to a different service/destination than what was indicated by the initial packet. However, the risk of unauthorised access of services is relatively low already for the reason that a user who sends packets to another server/service cannot receive any packets from that other server/service. This is so because the source address of that false destination would not match the downlink filter address, for example Ipv6 prefix, that is set up based on the Ipv6 prefix indicated by the original server at the SIP/SDP session establishment stage.
A further step may also be added to the screening procedure to improve security in this regards. In the further screening step, when further packets are being checked based on the address of the next router in the selected route as described above, a further check may be performed on the routing header to make sure that the user is not trying to cheat. Depending on what is to be checked, either a part of the routing header of the first packet or the whole routing header may be saved and compared later on against the header of subsequent packets. If the subsequent packet fails the test, it is dropped. For example, a gateway may compare the final destination address of the first data packet with the final destination address of any subsequent data packet. The length of the routing headers, segment's left field and/or the address fields of subsequent packets may also be checked. The entire routing header of a subsequent data packet may be compared with the routing header of the first data packet.
It shall be appreciated that whilst embodiments of the present invention have been described by using IPv6 Routing Header as an example, the same principles apply to any packet switched addressing method. For example, the filtering routine may be based on IPv4 source routing mechanism.
It shall also be appreciated that whilst embodiments of the present invention have been described in relation to user equipment such as mobile stations, embodiments of the present invention are applicable to any other suitable type of user equipment.
The examples are described with reference to PDP contexts. In alternative embodiments of the invention data packet may be transported on any suitable communication session, for example a Wireless Local Area Network (WLAN) access bearer connected to a policy controlled packet mobile network.
The embodiment of the present invention has been described in the context of a communication system that is based on a GPRS system. This invention is also applicable to any other communication systems and nodes where similar problem may exist. In addition to a gateway node such as a GGSN, similar filtering may be provided for example in wired IP or other packet switched network routers or in a packet data gateway (PDG) of a WLAN access to a policy controlled packet mobile network.
In addition, the term policy decision function (PDF) is intended to cover all controller entities configured to provide restriction parameters such as filtering criteria for controlling communication of packet data.
It is also noted herein that while the above describes exemplifying embodiments of the invention, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention as defined in the appended claims. | A method for transport control in a packet switched communication system is disclosed. In the method a data packet assigned with a destination address is received at a node. It may then be detected that the destination address does not meet a filtering criteria. It may then be checked if at least one further destination address has been assigned for the data packet. If it is found that at least one further destination address is assigned for the data packet, the filtering criteria is applied to the at least one further destination address. The data packet is forwarded from the node to a next node in response to detection that the data packet is assigned with a further destination address that meets the filtering criteria. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of German Application No. 10 2006 003 684.0, filed Jan. 24, 2006, the complete disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
a) Field of the Invention
The invention is directed to a method for generating a predetermined break line in a multilayer airbag covering in which the material of a carrier layer has a greater density than the material of an adjoining supporting layer adjoined by a decorative layer. A generic method of this kind is known from DE 102 27 118 A1.
b) Description of the Related Art
Many methods are known for introducing a predetermined break line in a multilayer airbag covering. Initially, only the dashboard or steering wheel hub were used as airbag coverings for covering a front airbag. In the meantime, it has become standard also for door panels and seat upholstery to cover a side airbag, for the inside roof lining to cover a head airbag, or even for the safety belt to cover a front airbag, e.g., for the rear passengers.
This has increased not only the variety of airbag covering constructions but also the variety of materials that are used to produce multilayer airbag coverings for this purpose. Currently, the most common layer construction for an airbag covering comprises a rigid carrier layer, e.g., of plastic or natural bonded fiber, a soft supporting layer, e.g., of foamed material or a spacer fabric, and a decorative layer, e.g., of plastic, woven textile or leather. In a layer construction of this kind, the material density of the carrier layer is appreciably greater than that of the supporting layer.
Although it is not expressly mentioned in all of the relevant publications, a predetermined break line with a defined tear resistance must be produced in principle and should be invisible from the passenger compartment (decorative side of the airbag covering) for aesthetic reasons.
The relevant prior-art methods for producing a predetermined break line of the type mentioned above differ substantially with respect to the sequence of individual method steps on one hand and the application of different cutting techniques on the other hand.
With regard to the technical sequence, the methods can be grouped according to whether the layer construction of the airbag covering is produced first and then a predetermined break line is introduced in the prefabricated airbag covering, or whether a predetermined break line is introduced in individual layers before these layers are assembled.
The different cutting techniques are essentially defined by the application of different tools. Mechanical cutting tools or chip-removing tools, heat knives, ultrasonic knives, and lasers are used for this purpose.
In recent years, laser methods in particular have progressed and expanded in application. For a layer construction of the type described above, lasers are especially advantageous in that no mechanical pressure is exerted on the workpiece (in this case, the airbag covering). Further, the tool is not subject to wear, which is particularly beneficial for large-scale production as in the automobile supplier industry. Further, it is advantageous that different ablation regimes which may be advantageous for different material compositions can be realized in a simple manner by selecting suitable laser parameters such as laser output and pulse frequency. Further, ablation can be regulated by detecting the working beam transmitted to the ablation site through the residual material or when there is an opening in the material.
In all of the known prior-art laser methods in which a predetermined break line is introduced in a prefabricated airbag covering having a layer construction of the type described above, a laser beam is directed to the airbag covering on the carrier layer side and is moved long the desired predetermined break line relative to the airbag covering. It is known to select the type of laser beam and its wavelength, the laser output, the relative speed, pulse duration, and pulse frequency depending on the layer construction and to regulate the variable laser parameters depending on the ablation depth or residual wall thickness.
As was already mentioned, the predetermined break line must have a reproducible tear resistance defined along its length. The tear resistance should be low enough so that, on the one hand, the predetermined break line can be destroyed by only a slight tearing force in case the airbag is activated and, on the other hand, so that the predetermined break line does not break already due to an uncontrolled random force acting on the passenger compartment side. An ablation regime is selected depending on a correspondingly suitable tear resistance and the material characteristics and material thickness of the individual layers. The remaining webs of material in the different layers, their widths and spacing, and the ablating depth determine the tear resistance along the predetermined break line.
Aside from a suitable reproducible tear resistance, it must also be ensured that the predetermined break line remains invisible over the long term. On the one hand, this means that the decorative layer may not be overly weakened by too great an ablation depth, and on the other hand the supporting layer must be retained as far as possible.
To solve this problem, it is known, for example, from DE 196 36 429 C1, to generate the weakened line by means of a series of blind holes. The blind holes extend completely through the carrier layer and the supporting layer into the decorative layer leaving a remaining residual wall thickness. Instead of blind holes, a satisfactory predetermined break line can also be generated by means of microperforations which are not perceptible to the naked eye.
However, practical experience has shown that these blind holes or microperforations have a nearly constant diameter only in the region of the carrier layer. In the region of the supporting layer, the blind holes undergo a distinct bubble-like expansion. The increased ablating volume in the supporting layer can be explained particularly in that the material density is substantially lower than in the carrier layer. In addition to the evaporation caused by the laser, the hot combustion gases also promote evaporation of the material. The combustion gases which can only escape in limited quantity via the opening of the respective blind hole in the carrier layer cause extensive displacement of the supporting layer due to their pressure combined with their temperature which accelerates the softening of the supporting layer.
Accordingly, in order to obtain webs in the supporting layer with an effective minimum width between the individual blind holes, there must be a defined minimum distance between the centers of the holes that is greater than the maximum diameter of the blind holes in the region of the supporting layer. For decorative layers with a high tear resistance, this distance may be too great for generating a weakened line with the desired tear resistance.
As a solution to this problem, the Applicant describes in Patent Application DE 102 27 118 A1 how groups of blind holes of different depth are deliberately generated. A first group extends only in the carrier layer so that the supporting layer lying above the latter is retained and a wide web is formed as a support for the decorative layer. A second group penetrates the supporting layer into the decorative layer. The distances between the hole centers can be selected so as to be small enough that webs are only retained in the decorative layer. Regardless of the distance, the supporting layer is destroyed in this ablation regime. This means that a smaller spacing causes a greater weakening of the decorative layer without affecting the supporting action of the supporting layer.
The weakening may also be unsatisfactory in this method when the tear resistance of the decorative layer is very high.
OBJECT AND SUMMARY OF THE INVENTION
It is the primary object of the invention to provide a method using a laser by which a predetermined break line in the form of a perforation line can be generated in a terminating decorative layer in a multilayer airbag covering, wherein broader webs are retained in an adjoining supporting layer compared to known methods in spite of smaller distances between the centers of the holes.
According to the invention, this object is met in a method for generating a predetermined break line in a multilayer airbag covering with a carrier layer, a supporting layer and a decorative layer. The method comprises the steps of providing that material of the carrier layer has a greater density than material of the supporting layer; generating blind holes or microperforations which are spaced apart along a desired predetermined break line in the decorative layer by a laser which impinges upon the airbag covering with a beam diameter (a) and which has a Gaussian beam density distribution: providing that the material of the carrier layer is completely ablated over a width (b) along the predetermined break line at least in the spaces between the spaced blind holes or microperforations, where (b) is greater than (a); generating the spaced blind holes or microperforations through the openings created in the carrier layer by the laser; and allowing the combustion gases that occur to escape through the openings.
It is essential to the invention that the ablation in the carrier layer is carried out so as to be deliberately broader than the diameter of the beam impinging on the airbag covering, or more exactly the supporting layer, for working the decorative layer so that the combustion gases occurring during the evaporation or combustion of the supporting layer and decorative layer can escape and not lead to undesirably large hollow spaces in the supporting layer. The ablation width is preferably greater than twice the diameter. The specific width at which a minimum combustion volume and therefore a minimum hollow space occurs in the supporting layer can be quickly determined by a few practical trials. The material characteristics of the supporting layer and its thickness in particular determine the rate of gas development and the amount of the occurring combustion gas volume.
In practice, the supporting layer which is connected to the decorative layer can be lasered without a carrier layer in a first trial. The combustion volume that occurs in so doing is a guideline for the minimum attainable combustion volume for subsequent trials. In the subsequent trials in which the complete layer construction is lasered, the carrier layer can first be provided with progressively larger openings. In this way, it is possible to gradually approximate an opening size which does not excessively weaken the carrier but allows the combustion gas to escape sufficiently quickly.
The openings can be constructed as individual holes whose center-to-center hole spacing is the same as that of the blind holes in the decorative layer. However, they can also be smaller than width b so that the holes overlap and no web remains in the carrier layer between the holes. However, a web width remaining at least between individual overlapping hole groups can be useful as a stabilizing connection in the carrier layer. In that case, it is possible to make the openings larger over their width rather than over their length along the predetermined break line. In contrast to an increasing length, an increasing width has no effect on the tear resistance of the carrier layer but enlarges the opening to the same degree.
The ablation in the carrier layer and in the decorative layer can be carried out at the same time, at overlapping times, or consecutively. It is compulsory that the carrier layer is ablated through its entire thickness. The supporting layer advantageously remains unaffected by this ablation. With thicker supporting layers, however, a slight ablation of the supporting layer also does not have disadvantageous results.
The invention will be described more fully in the following with reference to embodiment examples.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows a schematic sectional diagram of an airbag covering which is cut according to the invention;
FIG. 2 shows a schematic top view of an airbag covering which is cut according to the invention;
FIG. 3 shows the beam profiles of two lasers according to a first embodiment example; and
FIG. 4 shows the beam profiles of two lasers according to a second embodiment example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method according to the invention is used for working a multilayer airbag covering with a rigid carrier layer 1 and a supporting layer 2 succeeding the latter as was noted in the description of the prior art. The supporting layer 2 is made from a material with a lower density than that of the material of the carrier layer 1 . The supporting layer 2 is followed by at least one other layer, namely, the decorative layer 3 .
In a first embodiment example, the ablation in the carrier layer 1 and the ablation in the decorative layer 3 are carried out at the same time, i.e., the ablation in the carrier layer 1 , in the supporting layer 2 and in the decorative layer 3 are carried out directly one after the other at one place. A laser beam with an expanded annular beam density distribution is selected for working the carrier layer 1 , the beam being directed to the carrier layer 1 (see FIG. 3 ) coaxial to a laser beam with Gaussian beam density distribution. The two laser beams act on the airbag covering simultaneously. After the carrier layer 1 is ablated through its entire thickness at this location in the form of a round hole with a diameter twice as great as (a) in cooperation with the two laser beams, the laser is turned off and the ablation continues through the supporting layer 2 into the decorative layer 3 by means of the second laser whose beam cross section in the working area has a diameter (a) (see FIGS. 1 and 2 ). It will be clear to the person skilled in the art that diameter (a), which is ideally equal to the focusing diameter of the laser beam, is not ideally constant over the entire thickness of the airbag covering. However, these deviations are comparatively insignificant.
In a second embodiment example, a laser with a top head beam profile is used for the ablation in the carrier (see FIG. 4 ). The ablation in the decorative layer 3 is carried out after a delay.
The overlapping ablation in the carrier forms an opening which, in contrast to the first embodiment example, does not have an approximately round hole shape but rather extends more in direction of the predetermined break line, i.e., a slit-shaped opening (see the right-hand views in FIGS. 1 and 2 ). Alternatively, the openings in the carrier layer can have the shape of a hole or slit, or the shapes can be combined within one predetermined break line.
The advantage of delayed lasering of the decorative layer 3 consists in that the combustion gases developing at the respective ablation site when ablating the carrier layer have already evaporated and that the quantity of blind holes along the length of the slit-shaped ablation can be selected independent from the ablation of the carrier layer 1 .
In a third embodiment example, the ablation is carried out successively. For this purpose, it is advantageous that two lasers need not necessarily be used, and more than 10 blind holes or perforations can be introduced by means of a laser in a slot which is formed, e.g., by 10 overlapping hole-shaped openings. When working the carrier with laser beams as was described in the two first embodiment examples, the beam profile of the laser with Gaussian distribution, which is needed in any case for the ablation in the decorative layer 3 , can be modified by arranging special optics, e.g., an axicon, in front of it, which forms an annular beam density distribution from a Gaussian beam density distribution. The laser can also be used with its Gaussian beam density distribution when it is directed to the carrier material with corresponding defocusing.
When using a laser for ablation in the carrier layer 1 , it may be advantageous regardless of the beam profile to introduce a foil-type barrier layer between the carrier layer 1 and the supporting layer 2 when producing the airbag covering before implementing the method. The function of this foil-type barrier layer is to prevent laser radiation from penetrating into the supporting layer 2 during the ablation of the carrier material. The barrier layer is advantageously permeable to gas. In order to prevent damage to the barrier layer during the ablation of the carrier material, a material whose melting temperature is above the evaporation temperature of the carrier material must be used for the barrier layer.
When the barrier layer is not permeable to gas, it must be destroyed after the ablation of the carrier material. This can be carried out during the ablation of the decorative layer 3 by the higher energy input in the radiation peak of the laser or by mechanical destruction, e.g., by means of a knife. It is sufficient to introduce a slit in order for the barrier layer to be blown apart by the pressure of the combustion gases so that the combustion gas can escape.
Instead of using lasers to ablate the carrier layer 1 , a chip-removing tool can also be used for all three time regimes mentioned in the embodiment examples. For simultaneous ablation, a special cutter having a hollow core through which the laser radiation can be directed can be used, for example. Conventional drills or cutters in particular can be used for delayed ablation and ablation which is carried out consecutively.
While the foregoing description and drawings represent the present invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention. | The invention is directed to a method for introducing a predetermined break line in a multilayer airbag covering with a carrier layer, a supporting layer and a decorative layer by a laser. In order to prevent an undesirable burning of the supporting layer over a large area as a result of the occurring combustion gases, it is suggested that the carrier material is ablated by a width that is greater than the diameter of the impinging beam to facilitate the escape of the combustion gases. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2002-197503 filed in Japan on Jul. 5, 2002, the entirety of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transmission, and more particularly to a transmission for a saddle type vehicle (buggy) for operation on rough terrain.
2. Description of the Background Art
A conventional transmission of the background art is described in Japanese Patent Publication No. 63-61212, the entirety of which is hereby incorporated by reference. This transmission includes a primary shaft, a main shaft, and a countershaft. Power is transmitted between the primary shaft, main shaft and countershaft respectively, e.g., the countershaft is a final shaft in this transmission.
In general, gears having diameters larger than the diameters of gears mounted on front-stage shafts are mounted on rear-stage shafts, e.g., so as to sequentially reduce a rotational speed during power transmission. In the above-described transmission of the background art, larger-diameter gears are mounted on the final shaft.
More specifically, two larger-diameter gears having different diameters are fixed to the final shaft (the countershaft in the above publication). Two smaller-diameter gears normally meshing with the two larger-diameter gears are rotatably supported relative to the shaft (the main shaft in the above publication) provided on the directly front stage of the final shaft. Further, gear selecting and fixing means (a gear selecting mechanism in the above publication) is provided between these smaller-diameter gears. Either of these smaller-diameter gears is selected and fixed to the support shaft by the gear selecting and fixing means, thereby allowing the selection of any one of different operational conditions.
Applicants have determined that the background art suffers from the following disadvantages. As mentioned above, the two larger-diameter gears are mounted on the final shaft of the transmission in the related art, causing an increase in weight of the transmission.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings associated with the background art and achieves other advantages not realized by the background art.
An object of the present invention is to reduce the weight of the transmission by mounting only one larger-diameter gear on the final shaft;
One or more of these and other objects are accomplished by a transmission comprising an output shaft; a countershaft extending parallel to the output shaft; an intermediate shaft extending parallel to the output shaft; a forward drive gear being rotatably supported relative to the countershaft; a reverse drive gear being rotatably supported relative to the countershaft; a first intermediate gear being rotatably supported relative to the intermediate shaft, the first intermediate gear meshing with the reverse drive gear; a second intermediate gear rotatably supported relative to the intermediate shaft, the second intermediate gear being interlocked with the first intermediate gear to rotate therewith; an output shaft driven gear fixed to the output shaft, the output shaft driven gear meshing with the forward drive gear and the second intermediate gear; and a gear selecting and fixing device axially and movably mounted on the countershaft for selectively fixing the forward drive gear and the reverse drive gear to the countershaft.
One or more of these and other objects are further accomplished by a power unit for a four-wheeled vehicle comprising an internal combustion engine having a crankshaft arranged with respect to a longitudinal direction of the engine; a transmission including a main shaft operatively engaged with the crankshaft through a torque converter and a primary drive gear on the crankshaft and a primary driven gear on the main shaft; an output shaft; a countershaft extending parallel to the output shaft; an intermediate shaft extending parallel to the output shaft; a forward drive gear being rotatably supported relative to the countershaft; a reverse drive; gear being rotatably supported relative to the countershaft; a first intermediate gear being rotatably supported relative to the intermediate shaft, the first intermediate gear meshing with the reverse drive gear; a second intermediate gear rotatably supported relative to the intermediate shaft, the second intermediate gear being interlocked with the first intermediate gear to rotate therewith; an output shaft driven gear fixed to the output shaft, the output shaft driven gear meshing with the forward drive gear and the second intermediate gear; and a gear selecting and fixing device axially and movably mounted on the countershaft for selectively engaging the forward drive gear and the reverse drive gear to the countershaft.
With this configuration, only one larger-diameter gear is mounted on the final shaft of the transmission as the output shaft driven gear, thereby allowing a reduction in the overall weight of the transmission.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and 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
The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by Way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a side view of a four-wheeled buggy, e.g., saddle type vehicle for operating in rough terrain, having a transmission according to a preferred embodiment of the present invention;
FIG. 2 is an elevational view of a power unit in the vehicle shown in FIG. 1 ;
FIG. 3 is a rear elevation of a rear crankcase of the power unit;
FIG. 4 is a longitudinal sectional view of an internal structure of a crankcase, showing a structural relationship between a crankshaft and a main shaft;
FIG. 5 is a longitudinal sectional view of the internal structure of the crankcase, showing the structural relationship between the main shaft, a countershaft, an intermediate shaft, and an output shaft; and
FIG. 6 is a longitudinal sectional view showing a driving mechanism for a dog clutch for forward/reverse selection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will hereinafter be described with reference to the accompanying drawings. FIG. 1 is a side view of a four-wheeled buggy, e.g., saddle type vehicle for operating in rough terrain, having a transmission according to a preferred embodiment of the present invention. FIG. 2 is an elevational view of a power unit in the vehicle shown in FIG. 1 . FIG. 3 is a rear elevation of a rear crankcase of the power unit. FIG. 4 is a longitudinal sectional view of an internal structure of a crankcase, showing a structural relationship between a crankshaft and a main shaft. FIG. 5 is a longitudinal sectional view of the internal structure of the crankcase, showing the structural relationship between the main shaft, a countershaft, an intermediate shaft, and an output shaft. FIG. 6 is a longitudinal sectional view showing a driving mechanism for a dog clutch for forward/reverse selection.
As seen in FIG. 1 , a buggy includes a body frame 1 , a pair of right and left front wheels 2 provided at a front portion of the body frame 1 , and a pair of right and left rear wheels 3 provided at a rear portion of the body frame 1 . A power unit 6 configured by integrating an internal combustion engine 4 and a transmission 5 is supported by a central portion of the body frame 1 . The power unit 6 is arranged so that a crankshaft 7 extends in the longitudinal direction of the vehicle.
As will be described in greater detail hereinafter, the rotation of the crankshaft 7 is transmitted through a main shaft 8 , a countershaft 9 , and an intermediate shaft 10 (each being shown in FIG. 3 ) to an output shaft 11 in the transmission 5 . These shafts 8 , 9 , 10 , and 11 also extend parallel to the crankshaft 7 in the longitudinal direction of the vehicle. The front wheels 2 are driven by a front drive shaft 12 connected to the front end of the output shaft 11 , and the rear wheels 3 are driven by a rear drive shaft 13 connected to the rear end of the output shaft 11 . A steering handle 14 , a fuel tank 15 , and a saddle seat 16 are arranged in this order from the front side of the vehicle on an upper portion of the body frame 1 .
FIG. 2 is an elevational view of the power unit 6 as viewed from the front side of the power unit 6 . The power unit 6 generally includes a cylinder head cover 20 , a cylinder head 21 , a cylinder block 22 , and a crankcase 23 arranged in this order from the upper side of the power unit 6 . The crankcase 23 is divided into four parts along planes perpendicular to the crankshaft 7 . That is, as partially shown in FIGS. 4 and 5 , the crankcase 23 includes a front crankcase cover 24 , a front crankcase 25 , a rear crankcase 26 , and a rear crankcase cover 27 arranged in this order from the front side of the power unit 6 . In FIG. 2 , the front crankcase cover 24 is generally shown and the front crankcase 25 is slightly shown around the front crankcase cover 24 . Various devices and pipes are mounted on the front surface of the front crankcase cover 24 .
FIG. 3 is a rear elevation of the rear crankcase 26 , showing the positions of the crankshaft 7 , the main shaft 8 , the countershaft 9 , the intermediate shaft 10 , and the output shaft 11 . FIGS. 4 and 5 are longitudinal sectional views showing an internal structure of the crankcase 23 along these shafts 7 to 11 . More specifically, FIG. 4 shows the relationship between the crankshaft 7 and the main shaft 8 , and FIG. 5 shows the relationship between the main shaft 8 , the countershaft 9 , the intermediate shaft 10 , and the output shaft 11 . In FIGS. 4 and 5 , the arrow F indicates the front side of the crankcase 23 .
FIG. 4 shows a power transmitting mechanism for the crankshaft 7 and the main shaft 8 . The crankshaft 7 is rotatably supported through bearings to the front and rear crankcases 25 and 26 . An extended front end of the crankshaft 7 is supported through a bearing to the front crankcase cover 24 . The crankshaft 7 is divided into front and rear sections in the longitudinal direction. The front and rear sections of the crankshaft 7 are connected at their crank webs 7 a by a crankpin 7 b . An alternator 28 for producing alternating current by the rotation of the crankshaft 7 is mounted on a rear end portion of the crankshaft 7 (the rear section). Reference numeral 29 denotes an oil filter provided on the front crankcase cover 24 for cleaning a clutch operating oil.
A torque converter 30 is mounted on a front portion of the crankshaft 7 (the front section), and a primary drive gear 31 is mounted adjacent to the torque converter 30 . The primary drive gear 31 is rotatably supported through a needle bearing 32 relative to the crankshaft 7 . The torque converter 30 includes a pump impeller 33 fixed to the crankshaft 7 , a turbine runner 34 opposed to the pump impeller 33 , and a stator 35 . The primary drive gear 31 rotatable relative to the crankshaft 7 is connected to the turbine runner 34 , and power from the crankshaft 7 is hydraulically transmitted through the torque converter 30 to the primary drive gear 31 . A primary driven gear 36 normally meshing with the primary drive gear 31 is fixed to a front end portion of the main shaft 8 . The rotation of the crankshaft 7 is transmitted through the torque converter, the primary drive gear 31 , and the primary driven gear 36 to the main shaft 8 with a primary speed reduction obtained by the gears 31 and 36 .
FIG. 5 shows a power transmitting mechanism and its relationship with the main shaft 8 , the countershaft 9 , the intermediate shaft 10 , and the output shaft 11 . The main shaft 8 is rotatably supported through bearings to the front and rear crankcases 25 and 26 . A first-speed drive gear 40 , a second-speed drive gear 41 , and a third-speed drive gear 42 different in the number of teeth according to gear ratios are mounted on the main shaft 8 . The second-speed drive gear 41 and the third-speed drive gear 42 are fixed to the main shaft 8 , and the first-speed drive gear 40 is relatively rotatably supported through needle bearings 43 to the main shaft 8 . In the following description, a gear relatively rotatably supported through a needle bearing to a rotating shaft will be referred to generally as an idle gear. A first-speed hydraulic multi-plate clutch 50 is interposed between the main shaft 8 and the first-speed drive gear 40 . The first-speed hydraulic multi-plate clutch 50 has an outer member 51 fixed to the main shaft 8 and an inner member 52 connected to the first-speed drive gear 40 . A pressure plate 53 is axially movably engaged in the outer member 51 . The main shaft 8 has a front center hole 55 axially extending from the front end of the main shaft 8 to an intermediate portion and a rear center hole 56 axially extending from the rear end of the main shaft 8 to the intermediate portion. The rear center hole 56 is slightly larger in diameter than the front center hole 55 . Thus, the front center hole 55 and the rear center hole 56 of the main shaft 8 are not in communication with each other at this intermediate portion. The main shaft 8 further has an operating oil supply hole 57 communicating with the front center hole 55 and the first-speed hydraulic multi-plate clutch 50 , and has lubricating oil supply holes 58 communicating with the rear center hole 56 and the needle bearings 43 .
As shown in FIG. 5 , an operating oil for the first-speed hydraulic multi-plate clutch 50 is supplied from the front crankcase cover 24 side through an operating oil supply pipe 59 into the front center hole 55 , and is further supplied through the operating oil supply hole 57 into the clutch 50 . The operating oil supplied to the clutch 50 is introduced into a space between the outer member 51 and the pressure plate 53 . When the pressure plate 53 is moved by this oil pressure to engage the clutch 50 , the first-speed drive gear 40 is fixed to the main shaft 8 , so that the rotation of the main shaft 8 is transmitted to the first-speed drive gear 40 . A lubricating oil to the needle bearings 43 for supporting the first-speed drive gear 40 is supplied from the rear center hole 56 through the lubricating oil supply holes 58 .
The countershaft 9 is composed of a front countershaft 9 a and a rear countershaft 9 b integrally connected with each other. The countershaft 9 is rotatably supported through bearings to the front crankcase 25 , the rear crankcase 26 , and the rear crankcase cover 27 . A first-speed driven gear 60 , a second-speed driven gear 61 , and a third-speed driven gear 62 respectively meshing with the first-speed drive gear 40 , the second-speed drive gear 41 , and the third-speed drive gear 42 supported to the main shaft 8 are mounted on the front countershaft 9 a . The first-speed driven gear 60 is fixed to the front countershaft 9 a . The second-speed driven gear 61 and the third-speed driven gear 62 are idle gears, which are rotatably supported through needle bearings 63 and 64 relative to the front countershaft 9 a , respectively.
A second-speed hydraulic multi-plate clutch 65 is interposed between the front countershaft 9 a and the second-speed driven gear 61 . A third-speed hydraulic multi-plate clutch 66 is interposed between the front countershaft 9 a and the third-speed driven gear 62 . The second-speed hydraulic multi-plate clutch 65 has an outer member fixed to the front countershaft 9 a and an inner member connected to the idle gear 61 , and the third-speed hydraulic multi-plate clutch 66 has an outer member fixed to the front countershaft 9 a and an inner member connected to the idle gear 62 . These clutches 65 and 66 are similar in configuration and operation to the first-speed hydraulic multi-plate clutch 50 mentioned above. An operating oil for these clutches 65 and 66 is supplied through operating oil supply holes 67 and 68 formed in the front countershaft 9 a , respectively, thereby stopping idle rotation of the idle gears 61 and 62 to permit power transmission and effect a second-speed or third-speed reduction. A lubricating oil to the needle bearings 63 and 64 for respectively supporting the second-speed driven gear 61 and the third-speed driven gear 62 is supplied through lubricating oil supply holes 69 and 70 formed in the front countershaft 9 a .
The front countershaft 9 a has a front center hole 78 axially extending from the front end of the shaft 9 a to an intermediate portion and a rear center hole 79 axially extending from the rear end of the shaft 9 a to the intermediate portion. The front center hole 78 has a stepwise diameter, and the rear center hole 79 is larger in diameter than the front center hole 78 . Thus, the front center hole 78 and the rear center hole 79 of the front countershaft 9 a are not in communication with each other at this intermediate portion. On the other hand, the rear countershaft 9 b has a through center hole 80 axially extending between the opposite ends of the shaft 9 b . The front end of the rear countershaft 9 b is engaged with the rear center hole 79 of the front countershaft 9 a , thus making an integral rotation of the front and rear countershafts 9 a and 9 b . The rear center hole 79 of the front countershaft 9 a is in communication with the through center hole 80 of the rear countershaft 9 b.
The supply of the operating oil to the second-speed and third-speed hydraulic multi-plate clutches 65 and 66 is performed through a double pipe 81 inserted in the front center hole 78 of the countershaft 9 from the front crankcase cover 24 side. The double pipe 81 is composed of an outer pipe 8 la and an inner pipe 81 b inserted in the outer pipe 81 a . The operating oil to the second-speed hydraulic multi-plate clutch 65 is supplied through an oil passage defined between the outer pipe 81 a and the inner pipe 81 b and through the operating oil supply hole 67 . The operating oil to the third-speed hydraulic multi-plate clutch 66 is supplied through an oil passage defined inside the inner pipe 81 b and through the operating oil supply hole 68 . The lubricating oil to the needle bearing 63 for supporting the second-speed driven gear 61 is supplied from the front crankcase 25 side through an oil passage defined between the front countershaft 9 a and the outer pipe 81 a and through the lubricating oil supply hole 69 . The lubricating oil to the needle bearing 64 for supporting the third-speed driven gear 62 is supplied from the rear crankcase cover 27 side through the through center hole 80 , the rear center hole 79 , and the lubricating oil supply hole 70 .
A forward drive gear 71 and a reverse drive gear 72 are mounted on the rear countershaft 9 b . These gears 71 and 72 are idle gears. A manually operated dog clutch 73 , providing a gear selecting and fixing function, is interposed between these gears 71 and 72 so that the dog clutch 73 is engageable with either the gear 71 or 72 . Accordingly, either the gear 71 or 72 engaged with the dog clutch 73 is selectively fixed to the rear countershaft 9 b , thereby allowing power transmission. The rear countershaft 9 b is formed with lubricating oil supply holes 76 and 77 for respectively supplying the lubricating oil to needle bearings 74 and 75 for respectively supporting the forward drive gear 71 and the reverse drive gear 72 . The lubricating oil to the needle bearings 74 and 75 is supplied from the rear crankcase cover 27 side through the through center hole 80 and the lubricating oil supply holes 76 and 77 of the rear countershaft 9 b.
The intermediate shaft 10 is supported by the rear crankcase 26 and the rear crankcase cover 27 . A first intermediate gear 82 normally meshing with the reverse drive gear 72 and a second intermediate gear 83 having a long sleeve portion 83 a connected to the first intermediate gear 82 is rotatably supported relative to the intermediate shaft 10 . These gears 82 and 83 are idle gears. The lubricating oil to sliding portions of the intermediate shaft 10 for sliding the first and second intermediate gears 82 and 83 is supplied from the rear crankcase 26 side through a center hole of the intermediate shaft 10 and lubricating oil supply holes 84 of the intermediate shaft 10 .
The output shaft 11 is rotatably supported through bearings to the front crankcase cover 24 , the rear crankcase 26 , and the rear crankcase cover 27 . The output shaft 11 extends through the front crankcase 25 in a non-contact relationship therewith. An output shaft driven gear 85 normally meshing with the forward drive gear 71 and the second intermediate gear 83 is fixed to the output shaft 11 . The output shaft driven gear 85 is driven in a forward direction or a reverse direction through either the gear 71 or 72 engaged with the dog clutch 73 , thereby rotating the output shaft 11 in a direction adapted to the forward running or reverse running of the vehicle. The reverse driving of the output shaft driven gear 85 is effected only when the countershaft 9 is being rotated at the first speed.
All of the gears in this transmission are constant-mesh type gears, and what gear ratio is to be selected is determined by the hydraulic multi-plate clutches 50 , 65 , and 66 that is engaged. The hydraulic control for these clutches 50 , 65 , and 66 is performed by a valve body 90 (see FIG. 2 ) assembled as a hydraulic control unit including a solenoid valve and a pressure switching valve. As shown in FIG. 2 , the valve body 90 is mounted on the front surface of the front crankcase cover 24 .
As shown in FIG. 5 , the operating oil to the first-speed hydraulic multi-plate clutch 50 is supplied from the valve body 90 through an oil passage 91 formed in the front crankcase cover 24 and the operating oil supply pipe 59 inserted in the front center hole 55 of the main shaft 8 into the front center hole 55 , and is further supplied through the operating oil supply hole 57 to the first-speed hydraulic multi-plate clutch 50 .
The operating oil to the second-speed hydraulic multi-plate clutch 65 or the third-speed hydraulic multi-plate clutch 66 is supplied from the valve body 90 through an oil passage 92 or 93 formed in the front crankcase cover 24 and the outer passage or the inner passage of the double pipe 81 inserted in the front center hole 78 of the countershaft 9 into the front center hole 78 . The operating oil is further supplied through the operating oil supply hole 67 or 68 to the second-speed hydraulic multi-plate clutch 65 or the third-speed hydraulic multi-plate clutch 66 .
A driving mechanism for the dog clutch 73 for selecting the forward running or the reverse running of the vehicle is shown in FIGS. 3 and 6 . Referring to FIG. 6 , the outer surface of the dog clutch 73 is formed with a circumferential groove 73 a , and a shift fork 100 is engaged at its forked portion with the circumferential groove 73 a of the dog clutch 73 . The shift fork 100 is axially slidably engaged with a guide shaft 101 . The guide shaft 101 is a fixed shaft supported to the rear crankcase 26 and the rear crankcase cover 27 . The shift fork 100 is integrally formed with a shifter pin 102 opposite to the forked portion. The head of the shifter pin 102 is slidably engaged with a helical groove 103 a formed on a shift drum 103 .
The helical groove 103 a of the shift drum 103 is a short groove extending along a substantially half portion of the outer circumference of the shift drum 103 . Accordingly, an unnecessary portion of the shift drum 103 is cut away for the purpose of weight reduction. The shift drum 103 is supported to a drum shaft 104 . A drum driven gear 105 and a shift cam 106 are also mounted on the drum shaft 104 . The shift drum 103 , the drum driven gear 105 , and the shift cam 106 are joined together by an interlocking pin 107 to restrain their relative rotation, e.g., so that these members 103 , 105 , and 106 are rotated together.
A shift spindle 108 is rotatably supported to the rear crankcase 26 and the rear crankcase cover 27 . A sector gear 109 meshing with the drum driven gear 105 is fixed to the shift spindle 108 . When the shift spindle 108 is rotated, the drum driven gear 105 , the shift drum 103 , and the shift cam 106 are rotated together by the sector gear 109 . The shift spindle 108 is connected through an operating cable (not shown) to a shift lever (not shown) provided on the steering handle 14 of the vehicle, and is rotated by manually operating the shift lever.
As shown in FIG. 3 , the shift cam 106 is a star plate member, and a roller 111 supported at the upper end of a shift drum stopper 110 is in contact with the outer circumference of the shift cam 106 . The shift drum stopper 110 is pivotably supported to a in 112 , and a spring 113 is engaged with the shift drum stopper 110 to normally bias the roller 111 against the outer circumference of the shift cam 106 . This mechanism constitutes a rotational position holding device for the shift drum 103 such that the rotational position of the shift drum 103 becomes stable when the roller 111 comes into contact with any one of the valleys formed on the outer circumference of the shift cam 106 . There are three stable positions of the shift drum 103 corresponding to forward, neutral, and reverse conditions.
When the shift lever provided on the steering handle 14 of the vehicle is rotationally operated from a neutral position to a forward position or a reverse position, the shift spindle 108 and the sector gear 109 are rotated together, thereby rotating the drum driven gear 105 to a stable position given by the shift cam 106 . At the same time, the shift drum 103 is rotated about the drum shaft 104 together with the drum driven gear 105 by the operation of the interlocking pin 107 , so that the shifter pin 102 is pushed by the inner edge of the helical groove 103 a formed on the outer circumference of the shift drum 103 . As a result, the shift fork 100 supported to the guide shaft 101 is axially slid, and the dog clutch 73 is accordingly moved in the axial direction of the countershaft 9 through the circumferential groove 73 a of the dog clutch 73 . At this time, one of the projections formed at the opposite ends of the dog clutch 73 comes into engagement with either the forward drive gear 71 or the reverse drive gear 72 to fix the gear 71 or 72 to the countershaft 9 , thus allowing power transmission and effecting forward or reverse running of the vehicle.
According to this preferred embodiment as described above in detail, the countershaft and the intermediate shaft are provided parallel to the output shaft. The forward drive gear and the reverse drive gear are rotatably supported relative to the countershaft. The first intermediate gear and the second intermediate gear are rotatably supported relative to the intermediate shaft. The first intermediate gear is normally in mesh with the reverse drive gear, and the second intermediate gear is rotatable together with the first intermediate gear. The single output shaft driven gear normally meshing with the forward drive gear and the second intermediate gear is fixed to the output shaft as a final shaft. Further, the dog clutch, performing the gear selecting and fixing function, is provided to selectively fix the forward drive gear and the reverse drive gear to the countershaft, thereby selecting different operational conditions of the vehicle. Thus, only one larger-diameter gear is mounted on the final shaft of the transmission as the output shaft driven gear, thereby allowing a reduction in weight of the transmission.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | In the transmissions of the background art, two larger-diameter gears are mounted on a final shaft thereby causing an increase in weight of the transmission. The present invention reduces the weight of a transmission by mounting only one larger-diameter gear on a final shaft. The transmission of the present invention includes an output shaft; a countershaft extending parallel to the output shaft; an intermediate shaft extending parallel to the output shaft; a forward drive gear rotatably supported relative to the countershaft; a reverse drive gear rotatably supported relative to the countershaft; a first intermediate gear rotatably supported relative to the intermediate shaft, the first intermediate gear normally meshing with the reverse drive gear; a second intermediate gear rotatably supported relative to the intermediate shaft, the second intermediate gear being interlocked with the first intermediate gear to rotate therewith; an output shaft driven gear fixed to the output shaft, the output shaft driven gear being normally meshing with the forward drive gear and the second intermediate gear; and a gear selecting and fixing device axially movably mounted on the countershaft for selectively fixing the forward drive gear and the reverse drive gear to the countershaft. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for wrenching or torquing a threaded member of a movable device. More particularly, the wrenching apparatus is a power tool for loosening threaded nipples attached to meters.
Power tools to apply wrenching to threaded nuts and bolts have been disclosed in U.S. Pat. Nos. 3,955,447 and 4,027,560 to Parker and U.S. Pat. No. 3,706,244 to Wilmeth. These tools are used on devices that have a series of bolts and nuts; each tool uses one nut to provide the reaction force while wrenching is applied to another nut.
Wilmeth also shows in U.S. Pat. No. 4,309,923 a power tool for torquing a threaded connector mounted on a fixed pipe. In this case, the reaction force to the wrenching action on the connector is provided by a reaction foot that abuts the floor below the stationary pipe.
The prior art has not addressed the problem of loosening a threaded nipple from a meter after it has been disconnected for reconditioning and calibration. After years of service, the sealing compound used on the threads of the nipple sets so hard that it takes a torque in the range of 1000 to 2000 pound-feet to loosen a 3- or 4-inch nipple. Inasmuch as meters are made in different shapes and sizes, it is a difficult problem to hold the meter while such a large torque is applied to the nipple. A simple and practical structure for restraining meters of different configurations has not been found.
It is therefore a principal object of this invention to provide a wrenching tool that receives its reaction force solely from the device to which the threaded member is attached.
Another important object is to provide a power tool that is easily fitted to meters and nipples of different sizes.
Other features and advantages of the invention will be apparent from the description which follows.
SUMMARY OF THE INVENTION
In accordance with this invention, a power tool for loosening a threaded member of a movable device, such as a pipe nipple of a disconnected gas meter, comprises a rigid plate with an approximately centered bore so that the plate can be slipped over the nipple and placed against the meter, means attached to the rigid plate to engage or press against a part of the device, such as the flange at the top of the meter, a reaction arm with a hole at one end so that it can be slipped over the nipple and fastened to the rigid plate, a split-head wrench arm that can grip the nipple, and a hydraulic cylinder with its opposite ends connected to the reaction arm and wrench arm.
To make the tool of this invention usable on nipples of different diameters, the central hole in the rigid plate should be at least as large as the largest nipple that will be encountered. Bushings having bores of different diameters to slip on nipples of different diameters are provided to fit in the hole of the rigid plate and thus reduce the hole size to that of a specific nipple.
The plate or disk has a generally circular shape and is provided with a tangential extension on which a block can be mounted to act as the means that engages the device to provide the reaction force to the applied torque force. The flange at the top of a gas meter is a convenient and practical place where the block can establish the reaction point to a torque force. The rigid plate or disk also has a series of holes or perforations, equally spaced from one another along a circular line which is concentric with the central hole. The hole at one end of the reaction arm is dimensioned like the central hole of the rigid disk, i.e., it is at least as large as the largest nipple to be loosened and fits the bushings used with the rigid disk. The reaction arm has, intermediate its ends, a smaller hole that is aligned with the holes in the rigid plate when the reaction arm is slipped on the nipple and placed against the plate. A pin that fits this hole and any of the spaced holes in the plate is used to lock the reaction arm in different angular positions on the plate.
The wrench or torque arm grips the nipple and is rotatable counterclockwise while the reaction arm fastened to the disk by the pin cannot move because the block mounted on the disk is abutted against the flange at the top of the meter to prevent clockwise movement of the disk and reaction arm.
To apply the required force to the torque arm, a hydraulic cylinder is pivotally connected to the free ends of the reaction and torque arms. The distance between adjacent holes in the plate depends on the full distance traveled by the piston rod or plunger of the hydraulic cylinder. Thus, if each full extension of the piston rod causes the wrench arm to move away from the reaction arm by an additional angle of 15°, the holes in the rigid plate should be spaced from one another by substantially the same angle.
At the end of each stroke of the plunger of the hydraulic cylinder, the wrench arm has been moved to a new angular position. Thereupon, with the release of pressure on the hydraulic cylinder, the pin can be pulled out so that the reaction arm can be moved toward the wrench arm and thereby cause the piston rod to recede in the hydraulic cylinder. At this point, the pin can be inserted to lock the reaction arm to the plate at the hole adjacent the hole used by the pin before the wrench arm was partially rotated.
The hydraulic cylinder is again pressurized by hand pump or electrically driven pump to cause another angular displacement of the torque arm. At the completion of the stroke of the piston plunger, the pressure on the hydraulic cylinder is released and the reaction arm with the pin withdrawn is advanced toward the torque arm sufficiently to permit the pin to enter the hole in the plate next to the hole last used. By repeating these operational steps, the nipple not only is loosened from its cemented or frozen condition but also is rotated sufficiently so that it can then be easily removed from the meter with an ordinary wrench.
If the first and last holes in the series of holes in the rigid disk or plate are separated by an angle of at least 180°, it is rare that such an angular rotation of the nipple will not be adequate to permit the removal of the nipple with a simple wrench. In the rare case where a large torque is still required to rotate the nipple after the reaction arm has been locked to the disk at the last hole therein, the split head of the wrench arm is loosened so that it can be freely rotated clockwise back to the position it had when it was originally clamped on the nipple. Simultaneously, the reaction arm with the locking pin withdrawn is also rotated clockwise until the pin can enter the first hole or a hole near it in the series of holes in the disk. At this stage, the split head of the torque arm is again tightened to establish a firm grip on the nipple, and the repetitive operational steps are again performed until the nipple can be easily rotated counterclockwise with a simple wrench.
BRIEF DESCRIPTION OF THE DRAWINGS
For further clarification of the invention, the ensuing description will refer to the appended drawings of which:
FIG. 1 is a front isometric view of the power tool of the invention for torquing and loosening a threaded nipple of a gas meter when mounted on the nipple; and
FIG. 2 is an exploded isometric view showing the parts of the tool of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, the wrenching tool 10 of the invention comprises five principal parts: perforated disk 11, reaction block 12, reaction lever or arm 13, wrenching or torque lever or arm 14 and hydraulic cylinder 15.
Disk 11 has a substantially centralized bore 16 large enough to slide over the nipple that is to be loosened from the gas meter. To make disk 11 adaptable for use with nipples of various sizes, it is preferred to make bore 16 large enough to fit the largest nipple that will be encountered and to provide a bushing 17 that fits into bore 16 and has a smaller bore 18. For example, bore 16 may fit a 4-inch nipple and bushing 17 can adapt disk 11 for a 3-inch nipple. Obviously, a bushing 17 can be provided for each other nipple size such as 21/2- or 31/2-inch nipple.
With bushing 17 fitted on nipple N so that it abuts meter M and with disk 11 fitted on bushing 17, reaction block 12 is mounted on tangential extension 19 by having slot 20 of block 12 straddle flat edge 21 of disk extension 19. The position of block 12 along the length of edge 21 is adjustable so that it can be positioned to make the best engagement with the bottom of flange F in the top portion of meter M. Bolt 22 can be turned by hand to lock block 12 in the desired position on disk 11.
Disk 11 has a series of perforations or holes 23 equally spaced from one another along a circular line (imaginary) that is concentric with bore 16. With disk 11 mounted on nipple N, reaction arm 13 with bore 24 is slipped over nipple N and fitted on bushing 17. Preferably, arm 13 has bolts 25 extending radially into bore 24 so that they can be turned down until their ends loosely fit in groove 26 encircling bushing 17. Thus, bolts 25 can positively position arm 13 adjacent disk 11 while permitting arm 13 to rotate freely on bushing 17.
Reaction arm 13 has a hole 27 spaced from bore 24 by the same distance between any hole 23 and bore 16 of disk 11. In other words, hole 27 which is of the same size as holes 23 overlies the circular series of holes 23 and can be positioned to coincide with any hole 23 so that a simple plug or pin can be inserted in hole 27 and a chosen hole 23 to keep arm 13 in an angularly fixed position relative to disk 11.
FIG. 2 shows an elaborate pin 28 with ring 29 and stem 30. The length of pin 28 is substantially equal to the combined width of disk 11 and arm 13. While stem 30 could provide the place for gripping pin 28 with the fingers to insert it in hole 27 and any hole 23 or to withdraw pin 28 therefrom, FIG. 2 shows a thin rod 31 axially connected to the free end of stem 30 and a compression spring 32 encircling rod 31. A cylindrical cap 33, large enough to permit ring 29 to slide therein as a piston would, is attached by screws 34 and flange 35 to arm 13. Rod 31 extends through a hole in end 36 of cylindrical cap 33 and terminates in grip 37. The length of cap 33 is sufficient to hold ring 29, stem 30 and compression spring 32 in its expanded state. When grip 37 is pulled with the fingers, spring 32 must contract enough for pin 28 to be pulled out of a hole 23 so that arm 13 can be rotated in order to insert pin 28 in another hole 23. When grip 37 is released, spring 32 will automatically push pin 28 into the selected hole 23.
With disk 11, reaction arm 13 and bushing 17 mounted on nipple N so that block 12 on disk 11 presses against the bottom of flange F of meter M, torque arm 14 is fastened directly on nipple N adjacent to reaction arm 13. Torque arm 14 has means at one end for clamping arm 14 tightly on nipple N. Such means, as shown in FIG. 2, comprises bore 38 formed between end 39 of arm 14 and yoke-like part 40 connected to end 39 by a pair of bolts 41. Bore 38 is so shaped and dimensioned that part 40 will not contact end 39 when placed around nipple N; therefore, bolts 41 can be tightened to clamp arm 14 firmly on nipple N.
The ends of arms 13,14 remote from bores 24,38, respectively, have offset hangers 42,43 for hydraulic cylinder 15. Hanger 42 on arm 13 has slot 44 on the side of arm 13 that faces arm 14, while hanger 43 on arm 14 has slot 45 on the side of arm 14 that faces arm 13. Thus, slots 44,45 are in the same plane even though arms 13,14 are in different planes. Hangers 42,43 are fastened to arms 13,14, respectively, in any desired way, such as by welding or with bolts.
The conventional hydraulic cylinder 15 has base clevis 46 and plunger clevis 47. Clevis 46 is pivotally held in slot 44 by pin 48 inserted through hole 49 in hanger 42 and through hole 50 of clevis 46. Similarly, clevis 47 is pivotally held in slot 45 by pin 51 inserted through hole 52 in hanger 43 and through hole 53 of clevis 47. Cylinder 15, which has threaded adapter 54 for connecting the hose of a hydraulic pump (not shown), operated manually or by electric motor, may be installed with base clevis 46 in hanger 43 and plunger clevis 47 in hanger 42.
With the tool of the invention fully assembled and mounted on nipple N of meter M as shown in FIG. 1, reaction arm 13 is swung clockwise and locked to disk 11 by inserting pin 28 into a hole 23, preferably hole 23 nearest extension 19 of disk 11. The length of cylinder 15 with its plunger fully retracted naturally sets the minimum angular distance of torque arm 14 from reaction arm 13. At this minimum angle, bolts 41 are tightened until yoke-like part 40 firmly clamps nipple N in bore 38 of torque arm 14. To ensure that there will be no slippage of arm 14 on nipple N when a large torque force is applied by arm 14, it is advisable to have serrations or like irregularities on the curved surfaces that form bore 38. As known, serrations and the like tend to dig into the surface of nipple N and thus provide a more positive grip on nipple N.
Having connected the hose of a hydraulic pump to adapter 54 of cylinder 15, hydraulic pressure is then applied until the plunger of cylinder 15 is fully extended. Inasmuch as the position of reaction arm 13 is immovable because arm 13 is locked to disk 11 by pin 28 inserted through holes 27, 23 and because clockwise rotation of disk 11 is prevented by block 12 abutted against the bottom of flange F of meter M, the extension of the plunger of cylinder 15 forces counterclockwise movement of torque arm 14 and nipple N. Holes 23 are spaced from one another by a distance commensurate to the distance traveled by the fully extended plunger of cylinder 15. Hence, by pulling pin 28 out of hole 23 and manually pushing arm 13 to cause the plunger of cylinder 15 to be fully retracted, arm 13 is again locked to disk 11 by inserting pin 28 in hole 23 to the right of hole 23 from which pin 28 was withdrawn. With each extension of the plunger of cylinder 15, torque arm 14 and nipple N are moved counterclockwise by several angular degrees equal to the angular degrees between consecutive holes 23. After each such extension, reaction arm 13 is advanced to the next hole 23 in the counterclockwise direction. In the rare case where having advanced reaction arm 13 to hole 23 farthest from extension 19 of disk 11 has failed to loosen nipple N completely, the tool can be reset on nipple N to continue its use until nipple N is satisfactorily unscrewed.
To reset the tool, bolts 41 are loosened so that arm 14, while pin 28 is out of hole 23, can be swung by hand clockwise until pin 28 can be inserted in hole 23 nearest extension 19 of disk 11. With arm 13 again locked to disk 11 in its original starting position and with arm 14 swung clockwise until the plunger of cylinder 15 is fully retracted, bolts 41 are tightened to again firmly clamp arm 14 on nipple N. The tool is now ready to continue the stepwise loosening and unscrewing of nipple N as has already been described.
It will be noted that bores 16 and 24 of disk 11 and reaction arm 13, respectively, have the same diameter to fit on bushing 17, but bore 38 of torque arm 14 has a smaller diameter to fit and grip nipple N. However, if tool 10 is required for loosening nipples of only one diameter, then bushing 17 can be elminated and bores 16, 24 and 38 of disk 11, reaction arm 13 and torque arm 14, respectively, can all have substantially the same diameter to fit that particular nipple. Where tool 10 is required for loosening nipples of various diameters, a different bushing 17 is required for each nipple size other than the largest nipple. Alternatively, bushing 17 may be used for the first step-down in nipple size, and a cylindrical liner or sleeve may be inserted between a still smaller nipple and bushing 17. For example, if bores 16,24 fit a 4-inch nipple, bushing 17 can be made to fit in bores 16,24 and on a 31/2-inch nipple, and a sleeve can be slipped into the 31/2-inch bore of bushing 17 and over a 3-inch nipple.
Because of the tremendous torque applied by arm 14 on nipple N and the need to clamp nipple N between yoke 40 and arm 14 so tightly that there is no slippage, it is generally advisable to provide for each nipple size an arm 14 with bore 38 and yoke 40 dimensioned to fit a specific nipple size. It is possible to reduce bore 38 of arm 14 by placing serrated semicylindrical fillers within bore 38 to grip a nipple smaller than bore 38 but this may not always prevent slippage of arm 14 on a smaller nipple.
Variations and modifications of the invention as illustrated herein will be apparent to those skilled in the art without departing from the spirit or scope of the invention. For instance, the means for restraining clockwise movement of disk 11, shown as block 12 mounted on extension 19 of disk 11, can be replaced by a large pin or bolt through extension 19 of sufficient length beyond the back of disk 11 to engage the bottom of flange F of meter M. Also, a simple cylindrical sleeve can be substituted for flanged bushing 17. While bolts 25 in reaction arm 13 and groove 26 in bushing 17 are desirable for holding arm 13 in position before torque arm 14 is clamped on nipple, bolts 25 and groove 26 can be eliminated because arm 13 will be kept in position against disk 11 as so on as arm 14 is clamped on nipple N. Other known forms of pipe clamping means for torque arm 14 can be used in lieu of yoke 40. Accordingly, only such limitations should be imposed on the invention as are set forth in the appended claims. | A power tool for torquing a threaded member of a movable device, such as a pipe nipple of a gas meter sent for repairs, comprises a rigid disk with a bore to fit the nipple so that the disk can be placed against the meter, a block attached to the disk to prevent its movement, a reaction arm that cam be rotatably fitted on the nipple and locked to the disk, a torque arm that can be clamped on the nipple adjacent the reaction arm, and a hydraulic cylinder with its opposite ends connected to the reaction and torque arms to provide the force to move the torque arm. | 1 |
This is a continuation of copending application Ser. No. 08/484,189, filed Jun. 7, 1995, now U.S. Pat. No. 5,728,152.
FIELD OF THE INVENTION
This invention relates to bioprosthetic heart valves combining the advantages of stented and stentless valves. More particularly, the invention relates to biocompatible heart valve stents that are resorbed by the patient following implantation.
BACKGROUND OF THE INVENTION
Prosthetic heart valves may be used to replace diseased natural heart valves in human patients. Mechanical heart valves typically have a rigid orifice ring and rigid hinged leaflets coated with a blood compatible substance such as pyrolytic carbon. Other configurations, such as ball-and-cage assemblies, have also been used for such mechanical valves.
In contrast to mechanical heart valves, bioprosthetic heart valves comprise valve leaflets formed of biological material. Many bioprosthetic valves include a support structure, or stent, for supporting the leaflets and maintaining the anatomical structure of the valve. Stented bioprosthetic valves generally are prepared in one of two ways. In a first method of preparation, a complete valve is obtained from either a deceased human or from a slaughtered pig or other mammal. Human valves or valve components implanted into a human patient are referred to herein as a "homografts," while the corresponding animal valves or valve components are termed "xenografts." In the case of homografts, the retrieved valve typically is treated with antibiotics and then cryopreserved in a solution of nutrient medium (e.g., RPMI), fetal calf serum and 10% DMSO. In the case of xenografts, the retrieved valve is trimmed to remove the aortic root, and the valve is chemically cross-linked, typically in a glutaraldehyde solution. The cross-linked valve is then attached to a stent. The stent provides structural support to the valve and, with a sewing cuff, facilitates attachment of the valve to the patient by suturing. In a second method of preparation, individual valve leaflets are removed from a donor valve or are fashioned from other sources of biological material, e.g., bovine pericardium. The individual leaflets are then assembled by suturing the valve leaflets both to each other and to the stent. When bovine pericardium is used, the valve (trileaflet or bileaflet) is fashioned from one piece of pericardium. The material is then draped on the stent to form the "cusps."
One of the major functions of stents is to serve as a framework for attachment of the valve and for suturing the valve into place in the human patient. Toward that end, stents are frequently covered with a sewable fabric, and have a cloth sewing or suture cuff, typically an annular sewing ring, attached to them. The annular sewing ring serves as an anchor for the sutures by which the valve is attached to the patient. Various stent designs have been implemented in a continuing effort to render valve implantation simpler and more efficient. Inevitably, however, a stent limits interactions with aortic wall dynamics and tends to inhibit natural valve movement. This results in post-operative transvalvular gradients with resultant additional work burden on the heart. In addition, a stent causes a reduction in size of the bioprosthetic valve that can be placed in a particular location, since the stent and sewing cuff occupy space that otherwise would be available for blood flow.
Stentless valves have demonstrated better hemodynamic function than stented valves. This is because stentless valves are sewn directly into the host tissues, without the need for extraneous structure such as a sewing cuff. Such extraneous structures inevitably compromise hemodynamics. Stentless valves closely resemble native valves in their appearance and function, and rely upon the patient's tissues to supply the structural support normally provided by a stent. The main disadvantage to stentless valves has been in their difficulty of implantation. Stentless valves require both inflow and outflow suturing, and physicians qualified to implant stented valves can lack the surgical training and experience required for implantation of stentless valves.
Some bioprosthetic valve manufacturers have attempted to develop methods and materials to ease the implantation of stentless valves, including holders, different suturing techniques or suturing aids. None of these approaches has significantly shortened implant times without adversely affecting valve performance.
Stents for bioprosthetic heart valves have been formed from a variety of non-resorbable materials including metals and polymers. With non-resorbable materials, the long-term fatigue characteristics of the material are of critical importance. Unusually short or uneven wear of a stent material may necessitate early and undesirable replacement of the valve. The selected material must also be biocompatible and have the desired stress/strain characteristics.
Various biodegradable materials have been suggested or proposed for use with vascular or non-vascular implants. For example, Goldberg et al., U.S. Pat. No. 5,085,629 discloses a biodegradable infusion stent for use in treating ureteral obstructions. Stack et al., U.S. Pat. No. 5,306,286 discloses an absorbable stent for placement within a blood vessel during coronary angioplasty. Duran, U.S. Pat. No. 5,376,112 discloses an annuloplasty ring to be implanted into the heart to function together with the native heart valve. Duran suggests (Col. 6, lines 6-8) without further elaboration that the annuloplasty ring could be fashioned of resorbable materials.
The prior art stents are designed primarily to maintain a fluid flow patency for a selected period of time. These stents are not designed to support a secondarily functional tissue such as a valve apparatus. Thus, the prior art does not teach or suggest that heart valve stents, with their particular configuration and stress/strain requirements, could be fashioned of bioresorbable materials.
SUMMARY OF THE INVENTION
The invention relates to a bioprosthetic heart valve comprising a valvular tissue graft secured to a biocompatible, resorbable heart valve stent. The stent facilitates surgical joining of the bioprosthetic heart valve with valve-receiving cardiac tissue of a heart patient. Importantly, the stent is operably resorbed by the patient following substantially complete healing of said heart valve with said valve-receiving cardiac tissue. That is, the material of the stent is broken down and resorbed or metabolized by the patient's body to the extent that the stent no longer contributes substantially to the structure or function of the implanted bioprosthesis.
The valvular tissue graft of the bioprosthetic heart valve may be adapted to function at the aortic, mitral, tricuspid or pulmonic valve positions of the heart. Moreover, the stent of the present invention may comprise a sheath-type or frame-type stent structure of generally annular configuration, with either structure being contoured to the shape of the valvular tissue graft.
The sheath or frame may comprise a biocompatible, resorbable polymer, including without limitation dextran, hydroxyethyl starch, gelatin, derivatives of gelatin, polyvinylpyrolidone, polyvinyl alcohol, poly N-(2-hydroxypropyl)methacrylamide!, polyglycols, polyesters, poly (orthoesters), poly (ester-amides) and polyanhydrides. The polyesters may include without limitation poly (hydroxy acids) and copolymers thereof, poly ( epsilon!-caprolactone), poly (dimethyl glycolic acid) and poly (hydroxy butyrate). Most preferably the polymer comprises D,L-polylactic acid, L-polylactic acid, or glycolic acid, or copolymers of D,L-polylactic acid, L-polylactic acid, and glycolic acid.
A sheath-type or frame-type stent of the present invention may be manufactured to be of non-uniform rigidity in order to be adapted to the structural and functional characteristics of a particular valvular graft. Moreover, a polymer material of a resorbable stent of the present invention may be invested with one or more biological response modifiers. The biological response modifiers may include without limitation cell adhesion molecules, growth factors and differentiation factors.
The invention further comprises a method for treating a patient having a defective aortic valve, providing a bioprosthetic heart valve as described above, and surgically implanting the heart valve in the heart of the patient. The invention is applicable to patients requiring implantation of a bioprosthetic heart valve adapted to function at the aortic, mitral, tricuspid or pulmonic valve positions of the heart.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a bioprosthetic heart valve comprising a porcine valvular graft and a resorbable sheath-type stent of the present invention.
FIG. 2 is a perspective view of a resorbable sheath-type stent of the present invention, viewed in isolation from a valvular graft tissue.
FIG. 3 depicts a frame-type stent of the present invention.
DETAILED DESCRIPTION
The resorbable stents for prosthetic heart valves of the present invention create a new class of implantable heart valves, merging the benefits of stented and stentless valves. Using the stent and heart valve of the present invention, the surgeon is able to implant a bioprosthetic valve using a relatively simple procedure, comparable to that used for stented valves. Over time, the stent is resorbed, thereby yielding the hemodynamic benefits now observed with stentless valves. The patients additionally benefit from decreased crossclamp and bypass times during surgery, as well as from the improvement in quality of life that results from improved hemodynamics.
The resorbable stent of the present invention serves to support the bioprosthetic valve and provides for close approximation of the valve and adjacent host structures, allowing for rapid tissue ingrowth and effective tissue remodelling by the host. The resorbable stent provides a mechanical scaffold facilitating implantation with a minimum of suturing at the valve outflow aspect. This provides for relatively natural opening and closing of the valve leaflets without prolapse or perivalvular leakage. Preferably the stent is of the minimum possible thickness permitted by the particular resorbable material used for construction, allowing the largest possible bioprosthetic valve to be used for the implant.
The resorbable stent has mechanical properties sufficient to support the valve during implantation and during the post-implant healing period, while allowing the function of the adjacent structures, for example the aorta, to be retained. Preferably the stent is of sufficient flexibility such that the native compliance of the adjacent host structures (e.g., aorta) and of the valve commissures is not significantly reduced.
Preferably, the bioresorbable material of the stent degrades, post implantation, at a rate that allows good tissue incorporation, but that also results in sufficient resorption within the normal post-operative period, approximately 4-6 months. A variety of resorbable, biocompatible materials, for example polymers, may be employed for manufacture of the stent of the present invention. Homopolymers and copolymers such as those disclosed in U.S. Pat. No. 5,412,068, incorporated herein by reference, are appropriate for the resorbable stents of the present invention. Other polymers include without limitation dextran, hydroxyethyl starch, gelatin, derivatives of gelatin, polyvinylpyrolidone, polyvinyl alcohol, poly N-(2-hydroxypropyl)methacrylamide!, polyglycols, polyesters, poly (orthoesters), poly (ester-amides) and polyanhydrides. Preferably the stents of the present invention are fashioned from polyesters such as poly (hydroxy acids) and copolymers thereof, poly (ε-caprolactone), poly (dimethyl glycolic acid), or poly (hydroxy butyrate).
Most preferably the stents are manufactured of polymers of D,L-polylactic acid, L-polylactic acid, or glycolic acid, or copolymers (two or more) of D,L-polylactic acid, L-polylactic acid, and glycolic acid. Such polymers may be manufactured and configured as disclosed, for example, in U.S. Pat. No. 5,133,755, incorporated by reference herein.
It will be apparent to the average skilled artisan that particular bioresorbable materials may be chosen to fit particular patient needs. For example, polymers may be chosen to be resorbed within the normal 4-6-month interval referenced above, but other polymers may be chosen to be resorbed within shorter or longer intervals. Variations in selected times to resorption may depend on, for example, the over-all health of the patient, variations in anticipated immune reactions of the patient to the implant, the site of implantation, and other clinical indicia apparent to the skilled artisan.
Preferably the fabricated resorbable stent has an open, interconnected porosity allowing rapid clot stabilization and subsequent tissue ingrowth. The porous resorbable stent may be fabricated using any of a variety of processes known to those of average skill in the art, including a "replamineform" process, a positive replication process or common textile processes.
The replamineform process involves infiltrating a porous, inorganic structure (typically, calcium carbonate) with wax, dissolving the calcium carbonate, adding the appropriate monomer or mixture of monomers, polymerizing the monomers, and finally increasing the temperature to withdraw the wax. See, for example, Hiratzka et al., Arch. Surgery 114: 698-702 (1979), incorporated herein by reference. This process yields a positive copy of the porous, inorganic structure. Negative copies or casts of the porous inorganic structure may be made by filling the pores with a selected polymer, then dissolving the inorganic matrix (e.g., calcium carbonate) as a final step. What remains following completion of either the positive- or negative-cast steps of the replamineform process is a polymer with defined porosity.
A positive replication process is disclosed in, for example, Jamshidi et al., Resorbable Structured Porous Materials in the Healing Process of Hard Tissue Defects, ASAIO 34: 755-60 (1988), incorporated herein by reference. In principle, a positive replication process is very similar to the replamineform process.
In a further alternative embodiment, porosity can also be introduced by mixing the polymer with particles of a specific size range (e.g., 20 to 300 micron diameters), then dissolving those particles during a final stage of the fabrication process. For example, sodium chloride crystals may be incorporated into a polymer or copolymer by adding crystals of the salt to a solution of dissolved polymer. After evaporating the solvent, annealing the polymer or copolymer by heating, and cooling at controlled rates, the sodium chloride crystals may be leached out using water. This leaves a porous polymer matrix. Porosity and pore size may be controlled by varying the concentration and size of the crystals. See, for example, Hubbell and Langer, Chem. & Engineering News, Mar. 13, 1995, pages 47-50.
The open porosity of the above-described resorbable stents provides a scaffold for cellular ingrowth. To facilitate ingrowth of host or other cells either before or after implantation, a variety of biological response modifiers may incorporated into the structure of the resorbable stent. Biological response modifier molecules may be covalently or non-covalently coupled to the various internal and external surfaces defining the porosity of the resorbable stent, or may be incorporated directly into the resorbable material during, for example, the polymerization process. In the latter case, the biological response modifier is slowly released as the stent is resorbed.
Appropriate biological response modifiers may include, for example, cell adhesion molecules, cytokines including growth factors, and differentiation factors. Mammalian cells, including those cell types useful or necessary for populating the resorbable stent of the present invention, are anchorage-dependent. That is, such cells require a substrate on which to migrate, proliferate and differentiate.
Cell adhesion molecules (CAM) may be incorporated into the resorbable stent in order to stimulate cell attachment, which is critical for normal cell function. Various CAM useful for incorporation include without limitation fibronectin, vitronectin, fibrinogen, collagen and laminin. See, e.g., Beck et al., J. FASEB 4: 148-160 (1990); Ruoslahti et al., Science 238: 491-97 (1987). The cell attachment activity has been isolated to specific amino acids sequences (expressed herein with standard single-letter code), for example RGD in the case of fibronectin, fibrinogen, collagen, osteopontin and others, REDV from fibronectin and YIGSR from laminin. Hubbell et al., Bio/Technology 9: 586-72 (1991); Humphries et al., J. Cell Biol. 103: 2637-47 (1986); Graf et al., Cell 48: 989-96 (1987). Other examples of cell attachment domains include the heparin-binding domains of fibronectin, KQAGDV and GPRP-containing peptides of fibrinogen and EILDV-containing peptides of fibronectin. Hynes et al., Cell 69: 11-25 (1992); Loike et al., Proc. Natl. Acad. Sci. USA 88: 1044-48 (1991). Thus, any cell attachment peptide-containing molecules functional as CAM for the cells seeded onto or migrating into the resorbable stent may be incorporated into the stent structure during or after fabrication.
The bioresorbable stent may also be fabricated to have a structure conducive to formation of a stabilized blood clot after implantation. These include without limitation stents with relatively high porosity, i.e., relatively high internal surface area. Alternatively, the stabilized clot may be induced to form by inclusion of chemicals, e.g., coagulants, into the stent structure as described above. Inducing a stabilized clot layer to form on the surface upon implantation facilitates cell ingrowth and healing, with the clot layer potentially functioning as a provisional matrix for healing, comparable to that occurring during normal vessel repair. Van Der Lei et al., Int. Angiol. 10: 202-08 (1991), for example, reported on the poor healing of expanded polytetrafluoroethylene prostheses in general, but also reported success in encouraging complete healing by inducing a clot layer to form on the graft surface upon implantation.
Cellular ingrowth may be further facilitated through use of growth factors, including without limitation the fibroblast growth factors including acidic (1), basic (2) and FGF 3 through 9, platelet-derived growth factors including PDGF, PDGF-AA, PDGF-BB and PDGF-AB, transforming growth factors (β1-β5), epidermal growth factors including heparin-binding EGF, transforming growth factor α and other members of the epidermal growth factor family, the insulin-like growth factors I and II, platelet-derived endothelial cell growth factor and vascular endothelial growth factor. These factors have been shown to stimulate cellular migration (useful for attracting the appropriate cell population(s) into the stent), proliferation (cell replication) and protein synthesis (required for production of extracellular matrix as the newly indwelling cells remodel the resorbing structure of the stent). Albumin may be added to a particular growth factor to increase its effectiveness. Murray et al., Cancer Drug Delivery 1: 119 (1984).
Other biological response modifiers that may be incorporated into the resorbable stent of the present invention include without limitation polysaccharides, mucopolysaccharides, glycoproteins, and glycosaminoglycans such as hyaluronic acid, chondroitin, chondroitin 4-sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, alginate, poly-D-lysine, laminin and collagen types I, III and IV. It will be apparent to the average skilled artisan that variations in individual biological response modifiers or combinations of biological response modifiers may be employed to suit the requirements of particular cell types, stent materials, stent configurations, sites of implantation and patient needs.
Referring now to the Figures, a bioprosthetic heart valve with a resorbable stent may be fashioned to have an appearance very similar to the current Toronto SPV® valve (see, e.g., FIG. 1), marketed by St. Jude Medical, Inc., St. Paul, Minnesota. The Toronto SPV® valve is designed for implantation at the aortic valve position. See, for example, David et al., J. Heart Valve Dis. 1: 244-48 (1992). It will be appreciated by the skilled artisan, however, that the stent of the present invention is applicable to any heart valve that has been adapted or is adaptable to a stented configuration.
As depicted in FIG. 1 and FIG. 2, the valve 10 comprises a resorbable stent 12 and a valvular graft 14 adapted for implantation in the aortic position. Typically, the graft would constitute a cross-linked porcine xenograft. However, the stent may be used to support grafts from other species and, when appropriate, may provide support for a homograft.
The graft 14 has three leaflets 16, 18 and 20 meeting along commissures 22. The resorbable stent 12 may comprise a sheath contoured to the external surface of the valvular graft, as depicted in FIG. 1. In this configuration, the stent 12 consists of a generally annular base 24 and a triad of axially-projecting and circumferentially-spaced commissure supports 26, 28 and 30 communicating at their spaced lower ends by arcuate connecting portions 32.
The resorbable material of the stent 12 preferably is flexible, allowing inward and outward bending of the commissure supports 26, 28, 30 as well as limited deformability of the base 24. Preferably the flexibility of the stent 12 is selected and manufactured to approximate that of the valvular graft and its native supporting structure. As desired, the rigidity of the stent (reflective of flexibility) may vary from one point to another on the stent, i.e., the stent may be of non-uniform rigidity. For example, the stent may be manufactured of a resorbable polymer such that the base 24 is more or less rigid than the commissure supports 26, 28, 30. Alternatively, rigidity of the resorbable polymeric stent material may vary continuously from one region of the stent 12 to another region, or may vary in multiple step-wise increments from one region to another.
The bioresorbable sheath-type stent 12 is preferably attached to the valvular graft 14 using a continuous suture technique similar to that used to attach a non-resorbable polyester cloth to the current Toronto SPV® valve. Referring to FIG. 1, sutures 34 are found along the entire inflow 36 and outflow 38 edges of the valve 10 to ensure adequate attachment of the stent 12 to the valvular graft 14. Other techniques, including non-suturing techniques, are adaptable to attachment of the sheath-type stent to the valvular graft. These include, without limitation, laser-induced welding of the resorbable stent to the valvular graft.
In an alternative embodiment depicted in FIG. 3, the invention comprises a frame-type stent 40. The frame is contoured to conform to the shape of a valvular graft. In the embodiment depicted in FIG. 3, the frame is adapted to be used with a valve similar in configuration to the current Toronto SPV® valve. It will be appreciated by the skilled artisan, however, that the frame-type stent 40 may have a wide range of shapes to conform to any selected valvular graft configuration.
As depicted in FIG. 3, the stent 40 comprises an elongated flexible frame member 42 of over-all generally annular configuration. The frame member 42 may be generally circular in cross section, or may be oval or flattened in cross section. The frame member 42 is formed to define a triad of axially-projecting and circumferentially-spaced commissure supports 44, 46 and 48. As shown in FIG. 3, each commissure support is of generally U-shaped configuration, having legs 50 bending smoothly at their spaced lower ends with arcuate connecting portions 52.
The resorbable material of the frame member 42 preferably is flexible, allowing inward and outward bending of the commissure supports 44, 46, 48 as well as limited deformability of the frame-type stent 40 as a whole. Preferably the flexibility of the frame member 42 is selected and manufactured to approximate that of the valvular graft and its native supporting structure. As desired, the rigidity of the frame-type stent 40 (reflective of flexibility) may vary from one point to another on the stent, i.e., the stent 40 may be of non-uniform rigidity. For example, the stent may be manufactured of a resorbable polymer such that the arcuate connecting portions 52 are more or less rigid than the legs 50. Alternatively, rigidity of the resorbable polymeric stent material may vary continuously from one region of the stent 40 to another region, or may vary in multiple step-wise increments from one region to another.
The bioresorbable frame-type stent is preferably attached to the valvular graft using a winding suture around the frame, with the suture passing through the tissue of the valvular graft with each wind. As with the sheath-type resorbable stent, the frame-type stent may be attached to the valvular graft with other procedures, including without limitation laser-induced welding.
In the cases of both the sheath-type and frame-type stents of the present invention, any sutures used for attachment to a valvular graft and to the patient may be bioresorbable. Preferably the resorption rate of the sutures is similar to that of the stent.
A bioprosthetic heart valve with a resorbable stent of the present invention is implantable with a variety of surgical techniques appropriate to the configuration of the valvular tissue and stent and to the site of implantation. These surgical procedures will be apparent to the skilled artisan, and may include without limitation subcoronary implantation techniques similar to those used for free-hand homograft valve implant techniques. Such techniques are disclosed in, for example, R. A. Hopkins, Cardiac Reconstructions with Allograft Valves, Springer-Verlag (1989), pages 97-122. Generally, a series of interrupted sutures is placed around the tissue annulus. The valve is then parachuted down the sutures and tied in place. Following this, stay sutures are placed at the commissures to stabilize them into the adjacent host tissue, e.g., the aortic wall. The cardiovascular incision (e.g., aortotomy) is then closed and the heart restarted.
With the bioprosthetic heart valve and resorbable stent of the present invention, cross-clamp times for implantation will approximate those required with present stented valves, in which the stent consists of non-resorbable materials. This opens the "stentless" valve procedures to less skilled surgeons, who may not otherwise have the technical expertise to handle a typical stentless valve's more demanding surgical technique. Thus, additional patients receive the hemodynamic benefit of a "stentless" valve implant.
The foregoing detailed description has been provided for a better understanding of the invention only and no unnecessary limitation should be understood therefrom as some modifications will be apparent to those skilled in the art without deviating from the spirit and scope of the appended claims. | This invention relates to bioprosthetic heart valve stents that are fashioned of bioresorbable materials. Such stents may be configured as sheaths or frames contoured to the shape of a valvular graft. The stents are eventually resorbed by the patent, leaving a functional "stentless" valve with improved hemodynamic characteristics compared to stented valve implants. | 8 |
This is a division of application Ser. No. 09/149,082, filed Sep. 8, 1998 which is a divisional of Ser. No. 08/262,067 filed Jun. 17, 1994 now U.S. Pat. No. 5,865,907.
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to a composite magnetic member comprising at least one non-magnetized part and at least one ferromagnetized part, both parts being continuously and integrally formed, a process for producing the member and an electromagnetic valve using the member, and particularly to a composite magnetic member capable of fully maintaining ferromagnetic and non-magnetic characteristics against changes in temperature, a process for producing the member and an electromagnetic valve using the member.
2) Description of the Related Art
In generating a magnetic circuit in products such as electromagnetic valves, etc. by discretely providing a ferromagnetic part and a non-magnetic part in one product, it is necessary to make a mild steel part from a ferromagnetic material and an austenitic stainless steel part from a non-magnetic material individually, then assemble the ferromagnetic part and the non-magnetic part together while joining the parts properly by bonding, for example, by soldering, to make a member for the magnetic circuit. However, in making a member for the magnetic circuit in this manner, it is necessary to make a plurality of parts from a ferromagnetic material and a plurality of parts from a non-magnetic material individually and assemble such pluralities of the parts, while joining them by bonding. Thus, many steps and much labor are required for making such a member, complicating the procedure.
It is known that ordinary austenite stainless steel, high manganese steel, etc. are in a non-magnetic state after solid-solution treatment, but can be given a ferromagnetic property by cold working at room temperature to induce and generate a martensite structure. However, the degree of ferromagnetization obtained by this procedure is not high and thus it is actually difficult to apply this procedure to the production of members for the magnetic circuit.
It is also possible as a means for locally non-magnetizing part of a ferromagnetic material such as mild steel, etc. to diffuse an austenitizing element such as Mn, Cr, Ni, etc. into the ferromagnetic material from the surface, but such a means still has a problem in the production of members for the magnetic circuit.
JP-A-63-161146 discloses materials utilizable as a magnetic scale by optimizing the composition of austenite stainless steel or high manganese steel and working procedures for such materials to make members having both ferromagnetic and non-magnetic properties at the same time, where metastable austenite stainless steel is cold drawn into wires, thereby ferromagnetizing the austenite stainless steel based on martensitizing of austenite structure and part of the martensitized wires are further subjected to a local solid-solution treatment to locally non-magnetize the martensitized wires on the basis of local back-austenitization. Members having both ferromagnetic and non-magnetic properties at the same time can be obtained thereby. In this case, the composite magnetic members disclosed in JP-A-63-161146 can have a satisfactorily ferromagnetized part and a satisfactorily non-magnetized part, as integrated together, which can work satisfactorily under the ordinary circumstances, but no measures have been taken against temperatures at which the non-magnetized parts are to be used. That is, under severe temperature circumstance such as an extremely low temperature circumstance, a martensite structure is generated on the non-magnetized part, thereby transforming the non-magnetic properties to ferromagnetic properties. This has been a problem.
Currently available electromagnetic valves work as follows: a magnetic circuit is generated by passing an electric current through a coil in the valve, and a plunger is actuated through a sleeve undergoing magnetic working by the generated magnetic circuit. Particularly when an electromagnetic valve is used for oil-hydraulic control, the plunger must slide oil-tight along the inside surface of the sleeve. The conventional sleeve is made from a non-magnetic material, and to make the plunger behavior more sensitive, the magnetic circuit must be permeated through the non-magnetic material, and thus the force of excitation of the coil itself must be increased. Still furthermore, it is possible to ferromagnetize only part of the sleeve through which the magnetic circuit is to permeate. In the sleeve structure made by integrating a plurality of parts by bonding, the bonding must be carried out by soldering, welding, or the like to make the sleeve, and thus considerable post-working is required for obtaining desired dimension, shape and precision. Thus, there is a post-working problem.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a composite magnetic member comprising at least one satisfactorily ferromagnetized part and at least one satisfactorily non-magnetized part, both parts being continuously and integrally formed, which can work under severe circumstances such as an extremely low temperatures; a process for producing the member; and an electromagnetic member using the member.
At first, the present inventors have carefully checked what physical characteristics are desirable for a composite magnetic member having satisfactory ferromagnetic and non-magnetic characteristics at the same time under ordinary circumstances, and have found that a composite magnetic member is required to comprise a non-magnetized part having a relative magnetic permeability μ of not more than 1.2 and the remaining ferromagnetized part having a magnetic flux density B 50 of not less than 0.3 T at the same time except at the transition region between the non-magnetized part and the ferromagnetized part and except parts particularly not required for the ferromagnetic characteristics.
To satisfy the above-mentioned requirements, the present inventors have selected the following composition which can generate a stable austenite structure at room temperature and also generate a martensite structure by cold working to make the cold worked parts ferromagnetic and can give satisfactory magnetic characteristics.
A metallic member that can meet the above-mentioned requirements has a composition which comprises not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb, and the balance being Fe and inevitable impurities, where it is desirable that:
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19%, wherein % is and will be hereinafter by weight.
As to Hirayama's equivalent, reference is made to Nihon Kinzoku Gakkaishi (Journal of the Society of Metallurgy of Japan), 34 No. 5, 507-510 (1970); 34 No. 8, 826-829 (1970); 34 No. 8, 830-835 (1970); 35 No. 5, 447-451 (1971).
The C content is selected to be not more than 0.6% in the above-mentioned composition of the metallic member because shapability by working is lowered with increasing carbide content, though the magnetic characteristics can be satisfied over 0.6% C. The Cr content is selected to be 12 to 19% and the Ni content to be 6 to 12%, Since non-magnetic properties, for example, a relative magnetic permeability μ of not more than 1.2, cannot be obtained below the lower limit Cr and Ni contents, whereas above the higher limit Cr and Ni contents, B 4000 , a magnetic flux density when the intensity of magnetic field is 3.980 A/m, cannot be made less than 0.3 T (0.3 tesla). When the Mn content is over 2%, the shapability by working is lowered. Thus, the upper limit Mn content is selected to be 2%.
Furthermore, specific amounts of Mo and Nb can be contained in the metallic member. Mo, when contained, can effectively lower a Ms point, and Nb, when contained, can effectively contribute to an increase in the strength of the metallic member. Mo or Nb or both Mo and Nb can be contained, depending on the desired purpose. It is preferable that the metallic member contains not more than 2% Mo and not more than 1% Nb. Above these upper limit contents the shapability by working will be lowered.
Limitation of the respective elements to the above-mentioned ranges is still not satisfactory, and it is necessary that desired magnetic characteristics be obtained by combinations within these combination ranges. To this effect, Hirayama's equivalent H eq=20-23%, nickel equivalent Ni eq=9-12% and chromium equivalent Cr eq=16-19% must be satisfied in the present invention. Unless these conditions are not satisfied, only one of desired ferromagnetic characteristics and desired non-magnetic characteristics is satisfied.
Grounds for specifying these conditions will be explained below:
FIG. 1 shows a relationship between a Hirayama's equivalent and a relative magnetic permeability.
As is apparent from FIG. 1, a relative magnetic permeability μ is lowered with increasing Hirayama's equivalent H eq, and when the Hirayama's equivalent H eq is not less than 20%, a relative magnetic permeability μ of not more than 1.2 can be satisfied. Thus, the lower limit to the Hirayama's equivalent H eq is selected to be 20%.
FIG. 2 shows a relationship between a draft percentage at cold working and a magnetic flux density B 4000 after the cold working.
As is apparent from FIG. 2, the austenite structure is stabilized with increasing Hirayama's equivalent H eq, and as a result ferromagnetization by cold working is hard to take place and the magnetic flux density B 4000 is lowered. At the cold rolling as cold working, B 4000 =0.3 T was hard to obtain over H eq=23%, even if the draft percentage was increased. Thus, the upper limit to Hirayama's equivalent H eq is selected to be 23% in the present invention.
A nickel equivalent Ni eq and a chromium equivalent Cr eq are selected to be 9-12% and 16-19%, respectively, for the same reasons as above.
Usually not more than 2% Si and not more than, 0.5% Al as deoxidizing elements and other inevitable impurity elements are contained in the metallic member, but these elements will not give any adverse effect on the characteristics of the composite magnetic member, when produced.
The present inventors have further found that the metallic member having the above-mentioned composition did not have satisfactory magnetic characteristics under severe temperatures, and have made a further extensive study. That is, the present inventors made metallic members satisfying the above-mentioned conditions for the composition and subjected the members to solid-solution treatment to non-magnetize them, and then left them to stand at various low temperatures. As shown in FIG. 3, an increase in the relative magnetic permeability was observed in the members and the requirements of μ=not more than 1.2 as the non-magnetic characteristics were not satisfied.
Thus, it has been found further necessary that the metallic members having the above-mentioned composition satisfy the requirements for ferromagnetic and non-magnetic characteristics at the same time and undergo no change in the relative magnetic permeability μ of the non-magnetized part even under a severe temperature circumstance.
As a result of further extensive studies, the present inventors have found metal member structures without any change in the relative magnetic permeability μ even at an extremely low temperature, such as a temperature as low as −40° C. That is, the present inventors have found that an increase in the relative magnetic permeability μ at an extremely low temperature is due to a fact that the extremely low temperature is lower than an Ms point temperature, i.e. a temperature that initiates to transform the austenite structure to the martensite structure, and have conceived that an increase in the relative magnetic permeability at a temperature as low as −40° C. can be suppressed by making the Ms point temperatures of the metallic members having the above-mentioned composition lower than, for example, −40° C.
Thus, the present invention is characterized by changing grain sizes of austenite crystal grains to make the Ms point temperature lower than the conventional Ms point temperature, thereby suppressing changing of the non-magnetic characteristics to the ferromagnetic characteristics in an extremely low temperature circumstance. That is, the present invention has applied to the composite magnetic members for the first time the following fact the Ms point temperature that initiates to transform the austenite structure to the martensite structure is lowered be decreasing austenite crystal grain sizes.
FIG. 4 shows a conceptual diagram showing the above-mentioned fact. As is apparent from FIG. 4, the austenite crystal grain sizes and the Ms point temperature are closely related each other and the Ms point temperature is abruptly lowered at a specific crystal grain size.
FIG. 5 shows changes in the relative magnetic permeability μ of metallic member before cooling and after being cooled to and retained at −40° C. for one hour. As is apparent from FIG. 5, the present inventors have found for the first time that the relative magnetic permeability μ will not exceed 1.2, even when the metallic members is kept at −40° C. by selecting heating conditions so that the austenite crystal grain size is kept not more than 30 μm.
The present inventors have furthermore studied an optimum process for making the crystal grain size of austenite part (non-magnetized part) of the metallic member not more than 30 μm, and have found that the optimum process comprises subjecting the metallic member to cold working, thereby ferromagnetizing the member and then to solid-solution treatment within 10 seconds. That is, the heating of the member must be carried out for a very short time. An increase in the grain size in the region of the member, where the martensite structure is transformed to the austenite structure, can be prevented by conducting the solid-solution treatment within 10 seconds. To this effect, specifically it is desirable to use high frequency heating in the solid-solution treatment.
FIG. 5 will be explained in more detail below. That is, FIG. 5 shows a relationship between crystal grain size in the non-magnetized region obtained by local solid-solution treatment of the ferromagnetized part by high frequency heating and changes in the relative magnetic permeability μ after cooling to and retaining the non-magnetized region at −40° C. As already mentioned above, it has been found that the relative magnetic permeability μ will not exceed 1.2 even after having retained the non-magnetized region at −40° C. by selecting the heating conditions so that the crystal grain size can be kept not more than 30 μm.
The present inventors have found the desired conditions for metallic members applicable to desired composite magnetic members, as mentioned above, but have not yet found a fully satisfactory process for producing a desired composite magnetic member. For example, the present inventors tried to make cup-shaped members 10 shown in FIG. 10C by the conventional continuous press drawing work, but have found that the magnetic flux density B 4000 of not less than 0.3 T, as desired in the present invention, could not constantly be obtained only by conducting such a continuous press drawing work. As a result of further investigations, the present inventors have attributed the following fact to a failure to obtain the desired magnetic flux density B 4000 .
Explanation will be made, referring to FIG. 6, which shows a relationship between a degree of working in working steps and a working temperature of the metallic member under plastic working.
Once a strain is given to the metallic member, the working temperature of the member under plastic working will readily reach the Md point, a limit temperature for the transformation of austenite structure showing non-magnetic properties to martensite structure showing ferromagnetic properties due to heat generation during the plastic working. The present inventors have found that the further working over a point X corresponding to the Md point will be an over-working α that gives a strain that does not contribute any more the generation of martensite structure, and thus working only up to the point X can give an effective strain, though the over working α has a possibility for ferromagnetization.
Thus, the present inventors have conceived that the above-mentioned problem can be solved by giving a strain divisionally, thereby suppressing or reducing the heat generation during the working to a minimum, and that further ferromagnetization can be attained by cooling the member to not more than the room temperature to remove the heat generated during the divisional plastic working in advance to a succeeding divisional working step and then conducting the succeeding plastic working step to give a strain to the member.
That is, by conducting the plastic working such as drawing and ironing in a divisional manner, for example, at as many stages as possible, to obtain a metastable austenite stainless steel structure, it can be optimized to give a strain in the plastic working, as shown by a zigzag line B in FIG. 6, and the heat generation due to the plastic working can be suppressed thereby.
In FIG. 6, the plastic working shown by zigzag line B is conducted by dividing the conventional single working step to three stages {circle around (1)}, {circle around (2)} and {circle around (3)}.
By conducting the plastic working at a plurality of stages in this manner, the plastic working can be performed to the desired final degree of working while maintaining the working temperature below the Md point and thus a satisfactory ferromagnetic property can be given to the member.
Furthermore, the plastic working to give a strain can be carried out after cooling the member in advance. By cooling the member in advance, the working temperature of the member can be kept lower than the Md point even at the final degree of working, as shown by line C in FIG. 6, and the ferromagnetization level of the member, for example, B 4000 , can be readily made not less than 0.3 T thereby. That is, the member is cooled to an extremely low temperature such as down to −196° C. to improve the ferromagnetization level and remove the heat generated during the plastic working. By this cooling treatment, the target ferromagnetization level such as a magnetic flux density B 4000 of not less than 0.3 T can be attained without any increased number of working stages, that is, with a higher working efficiency. The working temperature of the member at the individual working stages should be not more than 100° C. for the following reasons.
FIG. 7 shows a relationship between a working temperature of metallic member and a martensite proportion (%).
The present inventors investigated a relationship between a strain-giving rate and an increase in the working temperature of the member by tension tests. Then, the present inventors conducted a tension test of metastable austenite stainless steel in a thermostat tank at a strain-giving rate of 1 mm/min at which the heat generation due to the plastic working could be disregarded. As a result, it was found that the no more martensite structure was generated at 100° C. or higher, as shown in FIG. 7 . That is, the proportion of generated martensite structure is 10% or less at 100° C. or higher. Thus, the desired magnetic characteristics could be obtained by using a working temperature of not more than 100° C. in the plastic working of the member.
The present inventors have made further studies and have found that stress corrosion cracking can be prevented by applying an ironing work of 10% or more to the metallic member after the drawing work.
FIG. 8 shows a relationship between a degree of ironing work and changes in residual stress.
The main factor for causing stress corrosion crackings is said to be a residual tensile stress occurring along the circumferential direction (see FIG. 9 ), generated by the drawing work, and the residual tensile stress can be considerably reduced by the ironing work. As shown in FIG. 8, the residual stress can enter into a region causing no more residual stress cracking at a degree of ironing work of 10%, and can be completely changed in a residual compression strain, contrary to expectation, at a degree of ironing work of 20% or more. Samples of an ironed member were evaluated by dipping in an aqueous 42% magnesium chloride solution. It was found by this test that no stress corrosion cracking occurred on the samples subjected to ironing work with a degree of ironing work of 10% or more as shown in Table 1. The ironing work is also a very effective means for giving a strain to attain ferromagnetization, and thus is one of steps for ferromagnetization.
TABLE 1
Degree of
0
5
10
20
30
40
50
ironing
Stress
occurred
occurred
non
non
non
non
non
corrosion
cracking
In summary, according to a first aspect of the present invention there is provided a composite magnetic member which comprises a metallic member comprising not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% No, not more than 1% Nb, and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19, wherein % is by weight, the metallic member being ferromagnetized by cold working, part of the ferromagnetized member being made by local solid-solution treatment to have crystal grain sizes of not more than 30 μm, thereby making the locally non-magnetized part have a relative magnetic permeability μ of not more than 1.2 at a temperature as low as −40° C.
It is preferable, after the ferromagnetization by cold working or after local non-magnetization of part of the ferromagnetized member by local heating, to further conduct a stress relieving annealing at a temperature of not higher than 500° C. By conducting the stress relieving annealing, the ferromagnetization can be further intensified. The stress relieving annealing is a treatment to improve the magnetic characteristics by removing plastic strains given to the member by cold working.
According to a second aspect of the present invention, there is provided a process for producing a composite magnetic member, which comprises ferromagnetizing a metallic member comprising not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb, and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19%, wherein % is by weight, by cold working, and then subjecting part of the ferromagnetized member to local solid-solution treatment within 10 seconds without melting the part, thereby making crystal grain sizes of the part not more than 30 μm and making the thus no-magnetized part have a relative magnetic permeability μ of not more than 1.2 at a temperature as low as −40° C. It is preferable to conduct the solid-solubilization treatment within 2 seconds.
According to a third aspect of the present invention there is provided a process for producing a composite magnetic member, which comprises subjecting a metallic member comprising not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb, and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19%, wherein % is by weight, to a drawing step and an ironing step, thereby ferromagnetizing the member, and then non-magnetizing part of the ferromagnetized member, thereby making the non-magnetized part have a relative magnetic permeability μ not more than 1.2 at a temperature as low as −40° C.
According to a fourth aspect of the present invention, there is provided a process for producing a composite magnetic member, which comprises subjecting a metallic member comprising not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb, and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19%, wherein % is by weight, to a strain-giving working step at a plurality of stages while controlling the working temperature of the individual working stages to not more than 100° C., thereby making the member into a ferromagnetized member having a magnetic flux density B 4000 of not less than 0.3 T, and then subjecting part of the ferromagnetized member to local solid-solution treatment within 10 seconds, thereby making crystal grain sizes of the solid-solution-treated part not more than 30 μm.
According to a fifth aspect of the present invention, there is provided a process for producing a composite magnetic member, which comprises cooling a metallic member comprising not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb, and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19%, wherein % is by weight, to a temperature of not more than room temperature, then subjecting the member to a strain-giving working step, while controlling working temperature to not more than 100° C., thereby making the member into a ferromagnetized member having a magnetic flux density B 4000 of not less than 0.3 T, and subjecting part of the ferromagnetized member to local solid-solution treatment within 10 seconds, thereby making crystal grain sizes of the solid-solution-treated part not more than 30 μm.
According to a sixth aspect of the present invention, there is provided a process for producing a composite magnetic member, which comprises subjecting a metallic member comprising not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb, and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19%, wherein % is by weight, to a strain-giving working step at a plurality of stages while controlling the working temperature of the individual working stages to not more than 100° C., then subjecting the member to ironing work at a degree of ironing of not less than 10%, thereby making the member into a ferromagnetized member having a magnetic flux density B 4000 of not less than 0.3 T, and then subjecting part of the ferromagnetized member to local solid-solution treatment within 10 seconds, thereby making the locally solid-solution-treated part have crystal grain sizes of not more than 30 μm. After the solid-solution treatment, the resulting member may be subjected to not working at a temperature of not less than 100° C, thereby forming the member into a desired shape.
According to a seventh aspect of the present invention there is provided an electromagnetic valve, which comprises a movable iron core provided slidably in a magnetic circuit formed by excitation of a coil, the movable iron core being adapted to open or shut a fluid passage by sliding caused by the excitation of the coil, and a support member with a slide hole through which the movable iron core is inserted slidably, at least one part of the support member being provided in the magnetic circuit, the support member being made from a metallic member comprising at least one ferromagnetized part and at least one non-magnetized part, as continuously and integrally formed, the non-magnetized part having a span of not less than 1 mm wide.
According to an eighth aspect of the present invention there is provided an electromagnetic valve, which comprises a movable iron core provided slidably in a magnetic circuit formed by excitation of a coil, the movable iron core being adapted to open or shut a fluid passage by sliding caused by the excitation of the coil, and a support member with a hole through which the movable iron core is inserted slidably, at least one part of the support member being provided in the magnetic circuit, the support member being made from a metallic member comprising at least one ferromagnetized part and at least one non-magnetized part, as continuously and integrally formed, and the non-magnetized part surrounding at least the lower end of the movable iron core.
In the first to third aspects of the present invention a remarkable composite magnetic member, whose non-magnetized part is never converted to a ferromagnetized part, even when exposed to a severe temperature condition, can be provided on the basis of the novel findings shown in FIGS. 1 to 5 .
In the first to sixth aspects of the present invention a composite magnetic member having at least one ferromagnetized part and at least one non-magnetized part, as continuously and integrally formed, can be produced quite easily, on the basis of the novel findings shown in FIGS. 1 to 8 .
In the seventh aspect of the present invention, a support member having at least one ferromagnetized part and at least one non-magnetized part, as continuously and integrally formed, is used in an electromagnetic valve and a movable iron core can be stably driven by using the non-magnetized part having a span of not less than 1 mm wide.
In the eighth aspect of the present invention the support member, whose non-magnetized part is made to surround the lower end of the movable iron core, is provided and thus the movable iron core can be more stably driven.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a characteristic diagram showing a relationship between a Hirayama's equivalent H eq and a relative magnetic permeability μ.
FIG. 2 is a characteristic diagram showing a relationship between a draft percentage and a magnetic flux density μ.
FIG. 3 is a characteristic diagram showing a relationship between a Hirayama's equivalent H eq and a relative magnetic permeability μ at various temperatures.
FIG. 4 is a conceptual diagram showing a relationship between a crystal grain size and temperatures at which transformation to a martensite structure takes place.
FIG. 5 is a diagram showing changes in a relative magnetic permeability of metallic member before cooling and after having been cooled to and retained at −40° C. for one hour.
FIG. 6 is a characteristic diagram showing a relationship between a degree of working in working step and a working temperature of metallic member under plastic working.
FIG. 7 is a diagram showing a relationship between a working temperature of metallic member and a martensite proportion (%).
FIG. 8 is a characteristic diagram showing a relationship between a degree of ironing work and changes in residual stress.
FIG. 9 is a view showing the circumferential direction along which a residual tensile stress occurs.
FIGS. 10A to 10 F show steps for producing the present composite magnetic member.
FIGS. 11A and 11B show steps for producing the present composite magnetic member.
FIG. 12 is a diagram showing a relationship between annealing condition for stress relieving and magnetic flux density.
FIGS. 13A to 13 F show steps for producing the present composite magnetic member.
FIGS. 14A and 14B show steps for producing the present composite magnetic member.
FIG. 15 is a vertical cross-sectional view of an electromagnetic valve using the present composite magnetic member.
FIG. 16 is a diagram showing a relationship between the width of non-magnetized part in an electromagnetic valve and a magnetic force.
FIG. 17 is a view showing a relationship between the width of a non-magnetized part in an electromagnetic valve and that of ferromagnetized part.
FIG. 18 is a vertical cross-sectional view of an electromagnetic valve using the present composite magnetic member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
EXAMPLES 1 TO 4
Alloys of compositions shown in the following Table 2 as Examples 1 to 4 were melted in a vacuum induction furnace and each formed into disk plates 1 , 1.0 mm thick, by casting and rolling, and the disk plates 1 were annealed into a softened state at 1,000° C. in a heating furnace.
TABLE 2
Ex-
am-
Chemical composition (wt %)
ple
C
Si
Mn
Ni
Cr
Fe
Ni eq
Cr eq
H eq
1
0.030
0.35
0.47
8.50
17.38
bal-
9.66
17.91
20.79
ance
2
0.030
0.35
0.51
10.15
15.52
bal-
11.35
16.05
21.31
ance
3
0.028
0.38
0.51
9.55
17.30
bal-
10.65
17.87
21.82
ance
4
0.028
0.38
0.51
10.62
17.29
bal-
11.72
17.86
22.88
ance
The disk plates 1 of alloys of Examples 1 to 4 thus prepared were subjected to stagewise drawing work at room temperature through the shape shown in FIG. 10B, while preventing an increase in the working temperature to obtain cup shapes 10 having a good ferromagnetic property, as shown in FIG. 10 C. Then, by further ironing work through shapes shown in FIGS. 10D and 10E to attain a degree of ironing (=t−t′/t×100) of 30% or more, where t is thickness of a disk plate before the ironing and t′ is that thereafter, desired cylinders 20 having a ferromagnetic property throughout were obtained, as shown in FIG. 10 F.
Degree of ferromagnetization by martensitization of austenite structure largely depends not only on the degree of working, but also on the working temperature, and further ferromagnetization can be attained by controlling the working temperature.
In the present invention, the following procedure was employed for local solid-solution treatment. That is, a high frequency coil 22 was provided to surround the middle part of the ferromagnetized cylinder 20 , as shown in FIG. 11A, and part of the cylinder 20 was locally heated and cooled by a cooling liquid at a temperature of about 20° C., thereby non-magnetizing the part. The following high frequency heating conditions were employed:
Frequency: 100 kHz
Plate voltage: 6 kV
Plate current: 2.1 A
Heating time: 0.8 sec
The high frequency heating was employed as a heating means for a non-magnetizing part of the cylinder 20 on the following grounds:
Heretofore, part of the martensite region (ferromagnetized region) has been subjected to local solid-solution treatment to convert it to an austenite region (non-magnetized region). For the local solid-solution treatment of the ferromagnetized region, a high energy beam such as a laser, an electron beam, etc. has been used. In order to form the non-magnetized region to a sufficient depth, the crystal grains having strains due to cold working have been once melted by hitting the surface of the ferromagnetized region with a high energy beam and immediately cooled to form a solidification structure, thereby non-magnetizing the ferromagnetized region. However, it has been difficult to make the non-magnetized region have a desired relative magnetic permeability μ of not more than 1.2 because of generation of δ ferrite peculiar to the solidification structure and enlarged crystal grains in the heat-influenced region near the molten part by the high energy beam, etc. Thus, it has been heretofore very difficult to obtain a non-magnetized region having a relative magnetic permeability μ of not more than 1.2 to a sufficient depth. Thus, high frequency heating is employed in the present invention.
Since the high frequency heating uses an eddy current locally generated in the member by high frequency current as a heating source, not only solid-solution treatment can be carried out very simply within a short time without any local melting by properly controlling the coil shape, frequency, current voltage, etc., but also crystal grain size can be prevented from enlargement because of a short heating time such as a few seconds.
The cylinder 20 was magnetically sectioned into, for example, three regions A, B and C, as shown in FIG. 11B, by the above-mentioned local high frequency heating and cooling, where the regions A and C had ferromagnetic characteristics, whereas the region B therebetween had non-magnetic characteristics.
Test pieces for determining magnetic characteristics were sampled from the ferromagnetized regions A and C and also from the non-magnetized region B of the thus obtained cylinders of Examples 1 to 4, and subjected to determination of magnetic characteristics by a DC magnetic fluxmeter or by a permeameter. The results are shown in the following Table 3, and it was found that composite magnetic members having desired magnetic characteristics and crystal grain sizes of not more than 30 μm as conditions for retaining the non-magnetic property at an extremely low temperature were obtained thereby.
TABLE 3
Magnetic
Relative
flux density
magnetic per-
Crystal grain
of ferro-
meability of
size of non-
magnetized
non-magnetized
magnetized
region
region
region
Example
B 4000 (T)
μ
μm
1
0.75
1.14
14
2
0.52
1.06
10
3
0.44
1.06
12
4
0.33
1.03
11
EXAMPLE 5
In Example 5, stress relieving annealing was further carried out at 500° C. or temperatures below 500° C. on the cylinder 20 of Example 2 after the above-mentioned cold working to attain further ferromagnetization. FIG. 12 shows changes in the magnetic characteristics of the cylinder of Example 2, when the cylinder was subjected to stress relieving annealing at 500° C. or temperatures below 500° C.
As is apparent from FIG. 12, the magnetic characteristics can be increased with increasing annealing temperature and the maximum magnetic characteristics can be obtained at 450° C. with air cooling.
The foregoing Examples 1 to 4 show an example of cup-shaped members, but the present invention is not limited thereto. That is, a pipe-shaped member can be made from the present metallic member composition for the present composite magnetic member and ferromagnetized by cold working such as drawing, etc., and the resulting ferromagnetized member can be locally non-magnetized by high frequency heating, or a plate-shaped member can be prepared from the present metallic member composition for the present composite magnetic member, ferromagnetized by cold working such as rolling, etc., and the resulting ferromagnetized member can be locally non-magnetized by high frequency heating.
In the foregoing Examples 1 to 4, high frequency heating was employed for a local solid-solution treatment, but the present invention is not limited thereto. That is, any procedure for heating only part of the ferromagnetized member to be non-magnetized within a short time without melting it can be employed in the present invention.
In Example 5 maximum magnetic characteristics could be obtained at an annealing temperature of 450° C., but the present invention is not limited thereto. That is, when the metallic member composition and cold working conditions are changed, an annealing temperature capable of obtaining optimum magnetic characteristics will change in a temperature range of not more 500° C.
EXAMPLES 6 TO 13
Alloys of compositions shown in the following Table 4 as Examples 6 to 13 were melted in a vacuum induction furnace and each formed into disk plates 1 , 1.2 mm thick, by casting and rolling as shown in FIG. 13A, and the disk plates 1 were annealed into a softened state by heating at 950° C.
TABLE 4
Chemical composition (wt %)
Example
C
Si
Mn
Ni
Cr
Fe
Mo
Nb
Ni eq
Cr eq
H eq
6
0.030
0.35
0.47
8.50
17.38
balance
—
—
9.66
17.91
20.79
7
0.030
0.35
0.51
10.15
15.52
″
—
—
11.35
16.05
21.31
8
0.028
0.38
0.51
9.55
17.30
″
—
—
10.65
17.87
21.82
9
0.028
0.38
0.51
10.62
17.29
″
—
—
11.72
17.86
22.88
10
0.046
0.41
0.60
8.38
18.01
″
—
0.32
10.06
18.78
21.43
11
0.052
0.33
1.03
8.22
17.09
″
—
0.76
10.29
18.06
21.24
12
0.029
0.18
0.43
8.25
17.65
″
0.51
—
9.8
18.4
20.6
13
0.030
0.19
0.43
8.35
16.91
″
1.03
—
10.1
18.2
20.2
The disk plates 1 of alloys of Examples 6 to 9 thus prepared were subjected to stagewise drawing work at room temperature through the shape shown in FIG. 13B to obtain cup shapes 15 , as shown in FIG. 13 C. The stagewise drawing of the disk plates 1 was carried out at 7 stages to prevent an increase in the working temperature and obtain a good ferromagnetic property, while keeping the working temperature of the disk plates 1 below 100° C., thereby obtaining the cup-shapes 15 . Then, by further ironing works through shapes, as shown in FIGS. 13D and 13E, to attain a degree of ironing (=t−t′/t×100) of 10% or more, where t is thickness of a disk plate before the ironing and t′ is that thereafter, desired cylinders 25 having a ferromagnetic property throughout were obtained, as shown in FIG. 13 F.
Degree of ferromagnetization by martensitization of austenite structure largely depends not only on the degree of working, but also on the working temperature, and further ferromagnetization can be attained by controlling the working temperature.
When the members of the compositions shown in Table 4 are worked into cup shapes only by drawing, there is a fear of stress corrosion cracking or season cracking due to residual stress. However, in these Examples 6 to 13, the residual stress can be reduced and the reduced residual stress can be converted from compression stress to tensile stress in the member by further ironing work. Thus, the stress corrosion cracking, etc. due to the residual stress, etc. can be prevented thereby.
In the present invention, the following procedure was employed for local solid-solution treatment. That is, a high frequency coil 27 was provided to surround the middle part of the ferromagnetized cylinder 25 , as shown in FIG. 14A, and part of the cylinder 25 was locally heated and cooled by a cooling liquid at a temperature of about 20° C., thereby non-magnetizing the part. The following high frequency heating conditions were employed:
Frequency: 100 kHz
Plate voltage: 6 kV
Plate current: 2.1 A
Heating time: 0.8 sec
Since the high frequency heating uses an eddy current locally generated in the member by high frequency current as a heating source, not only solid-solution treatment can be carried out very simply within a short time without any local melting by properly controlling the coil shape, frequency, current voltage, etc., but also crystal grain size can be prevented from enlargement because of a short heating time such as a few seconds.
The cylinder 25 was magnetically sectioned into, for example, three regions A, B and C, as shown in FIG. 14B, by the above-mentioned local high frequency heating and cooling, where the regions A and C had ferromagnetic characteristics, whereas the region B therebetween had non-magnetic characteristics.
Test pieces for determining magnetic characteristics were sampled from the ferromagnetized regions A and C and also from the non-magnetized region B of the thus obtained cylinders of Examples 6 to 13, and subjected to determination of magnetic characteristics by a DC magnetic fluxmeter or by a permeameter. The results are shown in the following Table 5, and it was found that compound magnetic members having desired magnetic characteristics and crystal grain sizes of not more than 30 μm as conditions for retaining the non-magnetic property at an extremely low temperature could be obtained.
TABLE 5
Magnetic
Relative
flux density
magnetic per-
Crystal grain
of ferro-
meability of
size of non-
magnetized
non-magnetized
magnetized
region
region
region
Example
B 4000 (T)
μ
μm
6
0.85
1.10
3
7
0.62
1.06
3
8
0.53
1.06
2
9
0.38
1.03
2
10
0.58
1.05
3
11
0.69
1.09
3
12
0.68
1.05
3
13
0.54
1.06
3
In the foregoing Examples 6 to 13, high frequency heating was employed for local solid-solution treatment, but the present invention is not limited thereto. That is, any procedure for heating only part of the ferromagnetized member to be non-magnetized within a short time without melting it can be employed in the present invention.
EXAMPLES 14 AND 15
In these Examples 14 and 15 cooling was conducted before giving a strain to the alloy. The alloy used in these Examples 14 and 15 was the alloy having the same composition as that of Example 6.
That is, the alloy of the same composition as in Example 6 was melted in a vacuum induction furnace and formed into disk plates 1 , 1.2 mm thick, as shown in FIG. 13A, by casting and rolling, and the disk plates 1 were annealed to a softened state by heating at 950° C.
The thus prepared disk plates were cooled to −77° C. by dipping the disk plates into a liquid methanol cooled to −77° C. by adding thereto dry ice in Example 14, whereas the other disk plates were cooled to −196° C. by dipping the disk plates into a liquefied nitrogen in Example 15.
Then, the disk plates thus prepared were subjected to stagewise drawing work at room temperature through the shape shown in FIG. 13B to obtain cup shapes 15 , as shown in FIG. 13 C. That is, the stagewise drawing was carried out at three stages to prevent an increase in the working temperature, while keeping the working temperature of the disk plate 1 below 100° C., thereby obtaining the cup shapes 15 . Then, by further ironing work through shapes, as shown in FIGS. 13D and 13E, to attain a degree of ironing (=t−t′/t×100) of 30% or more, where t is thickness of a disk plate before the ironing and t′ is that thereafter, desired cylinders 25 having a ferromagnetic property throughout were obtained, as shown in FIG. 13 F.
Then, the thus obtained cylinders were subjected to local high frequency heating and determination of magnetic characteristics in the same manner as in Examples 1 to 4. The results are shown in the following Table 6.
TABLE 6
Magnetic
Relative
flux density
magnetic per-
Crystal grain
of ferro-
meability of
size of non-
magnetized
non-magnetized
magnetized
Cooling
region
region
region
Example
(° C.)
B 4000 (T)
μ
μm
14
to −77
0.92
1.10
3
15
to −196
1.18
1.09
3
As is apparent from Table 6, composite magnetic members having a ferromagnetic property can be obtained by cooling the alloy before the drawing, and composite magnetic members having at least one satisfactorily ferromagnetized part and at least one satisfactorily non-magnetized part, as continuously and integrally formed, can be obtained with less working steps by cooling before the strain-giving working.
EXAMPLE 16
In this Example 16, application of the composite magnetic members obtained in the foregoing Examples 1 to 4 to an electromagnetic valve to be employed in automobiles, etc. will be described.
FIG. 15 is a vertical cross-sectional view of an electromagnetic valve for closing an oil-hydraulic line, using the present composite magnetic member.
An electromagnetic valve 30 is provided with a cup-shaped sleeve 32 with a ferromagnetized part 32 a and a non-magnetized part 32 b as continuously and integrally formed by cold working and high frequency heating of alloy of Example 1 as a support member. The sleeve 32 is coaxially with a coil 31 . The sleeve 32 is hermetically bonded to a stator 33 as a ferromagnetic core by bonding such as welding, etc. so as to prevent any leakage of an oil-hydraulic fluid.
A plunger 34 as a slidable, movable iron core is inserted into the sleeve 32 , and the plunger 34 is hermetically fixed to an upper end of a shaft 35 , whereas a ball 36 is fixed to the lower end of the shaft 35 . An insertion hole 37 is formed in the stator 33 in the axial direction so that the shaft 35 can slidably move through the insertion hole 37 .
At the ball 36 -fixing end, i.e. the lower end, of the shaft 35 , outflow openings 50 are provided in the radial direction and a seat valve 38 is inserted into the insertion hole 37 . A hole 54 communicating an inflow opening 52 with the outflow openings 50 is provided through the seat valve 38 . A valve seat 56 is formed on the top end of the seat valve 38 . A spring 39 is provided between the seat valve 38 and the shaft 35 against the valve seat 56 to give an expansion force to the shaft 35 in the direction to depart the ball 36 from the valve seat 56 . A ferromagnetic yoke 40 is provided in contact with the stator 33 and the sleeve 32 so as to cover the outer periphery of the coil 31 .
Working of the electromagnetic valve 30 , as shown in FIG. 15, will be explained below:
Normally, the shaft 35 and the plunger 34 are pressed to the top end of the sleeve 32 by the expansion force exerted by the spring 39 , and the ball 36 is departed from the valve seat 56 thereby. Thus, the inflow opening 52 is communicated with the outflow openings 50 through the communication hole 54 to open the valve, and the oil-hydraulic fluid is passed from the inflow opening 52 to the outflow openings 50 .
When it is necessary to close the valve on the other hand, excitation of the coil 31 is made to take place by passing an electric current through the coil 31 and a magnetic circuit is generated in the direction of yoke 40 →ferromagnetized part 32 a of the sleeve 32 →plunger 34 →stator 33 , as shown by excitation route L as the magnetic circuit, whereby the plunger 34 is attracted downwards in the axial direction to push the shaft 35 to slide through the insertion hole 37 . Then, the ball 36 is set onto the valve seat 56 to shut off communication of the inflow opening 52 with the outflow openings 50 and close the valve.
When the valve is to be opened, the electric current to the coil 31 is shut off, thereby decaying the magnetic circuit. By the expansion force exerted by the spring 39 , the shaft 35 slides upwards and the upper end of the plunger 34 is moved upwards to contact the inside top end of the sleeve 32 . Thus, the ball 36 is departed from the valve seat 56 . Thus, the inflow opening 52 is communicated again with the outflow openings 50 through the communication hole 54 to open the valve.
The sleeve 32 will be explained in detail below.
The sleeve 32 is ferromagnetized throughout by drawing work and ironing work and then locally non-magnetized in a desired region by high frequency heating, as described in Examples 1 to 4. Position and span or width of the non-magnetized region give a large influence on the magnetic force acting on the plunger 34 . That is, the electromagnetic valve of this Example is formed so that a clearance 60 is provided between the plunger 34 and the stator 33 within the axial length of the coil 31 . By providing the clearance 60 within the axial length of the coil 31 , a decrease in the magnetic force due to leakage of magnetic flux can be prevented when an electric current is applied to the coil 31 .
The span or width of the non-magnetized part 32 b formed in the sleeve 32 also contributes to prevent a decrease in the magnetic force.
FIG. 16 shows a relationship between a span or width of non-magnetized part 32 b and a magnetic force.
As is apparent from FIG. 16, the magnetic force is abruptly lowered when the span or width of the non-magnetized part 32 b is less than 1 mm, and thus the lower limit width must be 1 mm. Furthermore, as shown in FIG. 17, when the upper limit width of the non-magnetized part 32 b is set to an l/L ratio of not more than 0.95, where L is the axial length of sleeve 32 and l is the axial length of non-magnetized part 32 b, a sufficiently satisfied magnetic force can be obtained, because when the width of non-magnetized part 32 b is less than 1 mm, a relative magnetic permeability μ at the clearance 60 is smaller than that of non-magnetized part 32 b of the sleeve 32 , and consequently the magnetic circuit that goes through the clearance 60 will go around the non-magnetized part 32 b of the sleeve 32 , and the magnetic force onto the plunger 34 will be lowered.
Furthermore, when a ratio l/L is more than 0.95, the width of the ferromagnetized part 32 a will be smaller and consequently the magnetic flux that generates a magnetic circuit will be saturated, and the magnetic force will be also lowered.
In FIG. 15, the ferromagnetization of sleeve 32 was uniformly carried out along the entire axial length of sleeve 32 by further ironing work within a temperature range not exceeding the Md point, as in Examples 6 to 13, and the magnetic force was stabilized thereby.
Furthermore, not only uniform ferromagnetization but also higher dimensional precision could be obtained at the same time by drawing work, followed by ironing work.
When the conventional composite magnetic member having a ferromagnetized part and a non-magnetized part, as integrally formed, was used as a sleeve 32 for an electromagnetic valve, the top end part of sleeve 32 was ferromagnetized, and thus when an electric current was passed through a coil 31 , the generated magnetic flux went not only along the side surface of the sleeve 32 , as shown in FIG. 15, but also went around the top end part. Thus, the magnetic force was lowered.
In the present invention, on the other hand, the sleeve 32 was formed by cold working the top end part of the sleeve 32 at a lower degree of plastic deformation than that of the side surface of the sleeve 32 , and thus a lower stress was applied to the top end part of the sleeve 32 , thereby lowering the ferromagnetization level at the top end part, as compared with that along the side surface. That is, two ferromagnetized parts having different ferromagnetization levels could be formed on the same sleeve 32 , and thus when the upper end of plunger 34 was made to contact the inside periphery at the top end part of the sleeve 32 in a point or line contact state, the magnetic flux no more went around the top end part of the sleeve 32 . Thus, in the present invention uniform and sufficient ferromagnetic characteristics were obtained at the site where such characteristics were required, and the ferromagnetic characteristics could be suppressed to a lower level at the site where not required.
In the present electromagnetic valve, the magnetic flux density B 4000 was made to be not less than 0.3 T as the ferromagnetization level on the side surface of the sleeve, whereby the magnetic force could be stabilized.
After the entire sleeve 32 was ferromagnetized by ironing work, non-magnetized part 32 b was locally formed on the sleeve 32 by conducting local high frequency heating to the part desired to be non-magnetized from the outside or the inside of the sleeve 32 , thereby uniformly conducting solid-solution treatment of the desired part on all the outer and inner peripheral sides at the same time. Thus, the high frequency-heated part of sleeve 32 could be completely and uniformly non-magnetized with a better dimensional precision. By making the relative magnetic permeability μ as a non-magnetic level not more than 1.2, the magnetic force could be stabilized.
By employing the present composite magnetic member comprising at least one ferromagnetized part 32 a and at least one non-magnetized part 32 b, as continuously and integrally formed, as the sleeve 32 for the electromagnetic valve 30 , as shown in this Example 16, the magnetic flux could be effectively generated by passing an electric current through the coil 31 , while considerably reducing the magnetic resistance at the ferromagnetized part 32 a of sleeve 32 , contributing to efficient driving of plunger 34 . Thus, the magnetic force could be increased by about 40% over that of the conventional sleeve having only the non-magnetized part. That is, the amount of coil could be reduced, corresponding to the 40% increase in the magnetic force, and the electromagnetic valve could be made considerably smaller in the size.
Still furthermore, the drawing work and ironing work were used in the formation of sleeve 32 , and thus the desired parts could be made thin to an extreme limit with a better dimensional precision, whereby the electromagnetic valve could be made much smaller in the size.
EXAMPLE 17
FIG. 18 is a vertical cross-sectional view of another electromagnetic valve for opening or closing, for example, an oil hydraulic line, using the present composite magnetic member, where identical members to those of FIG. 15 are identified with the identical numerals.
The electromagnetic valve shown in FIG. 18 has also a sleeve 32 with two ferromagnetized parts 32 a and one non-magnetized part 32 b coaxially with a coil 31 , and the sleeve 32 is inserted into a hole 33 a of a stator 33 as a ferromagnetic core and hermetically bonded to the stator 33 by bonding such as welding, etc. so as to prevent any leakage of an oil-hydraulic fluid.
A ferromagnetic stopper 70 is hermetically fixed to the inside top end of sleeve 32 by a hermetically fixing means such as welding, caulking, etc. Below the lower end of the stopper 70 and inside the sleeve, a slidable ferromagnetic plunger 74 is inserted into the sleeve 32 , as separated by a non-magnetic plate 72 . The plunger 74 is fixed to the upper end part of a shaft 35 at a given distance from the top end of the plunger 74 to provide a hollow space 84 and a ball 36 is fixed to the lower end of the shaft 35 .
An insertion hole 37 through which the shaft 35 can slidably move is formed through the stator 33 in the axial direction. Inflow openings 76 are provided through the stator 33 at the ball 36 -fixing end, i.e. lower end, of the shaft 35 , and a seat valve 38 with a valve seat 82 is inserted into an outflow opening 78 at a contacting position with the ball 36 , and a hole 80 that communicates the inflow openings 76 with the outflow opening 78 is provided through the seat valve 38 in the axial direction.
Into a hollow space 84 formed between the top end of the plunger 74 and the upper end part of the shaft 35 , a spring 86 is provided between the lower end of the stopper 70 and the upper end of the shaft 35 to exert an expansion force so that the fixed assembly of the plunger 74 and the shaft 35 can move downwards to put the ball 36 onto the valve seat 82 . A ferromagnetic yoke 88 is provided in contact with the stator 33 and the sleeve 32 to cover the outer periphery of a coil 31 .
Working of the electromagnetic valve of this Example 17 will be explained below.
Normally, the fixed assembly of shaft 35 and plunger 74 is pushed downwards in the axial direction by the expansion force exerted by the spring 86 to put the ball 36 onto the valve seat 82 . Thus, communication of the inflow openings 76 with the outflow opening 78 is shut off and also the flow of the oil-hydraulic fluid is shut off.
When the valve is to be opened, on the other hand, an electric current is passed through the coil 31 to excite the coil 31 , and a magnetic circuit is generated, as shown by an excitation route R in FIG. 18, in the direction of yoke 88 →stator 33 →lower ferromagnetic part 32 a of sleeve 32 →plunger 74 →stopper 70 →upper ferromagnetic part 32 a of sleeve 32 , whereby the plunger 74 is attracted upwards in the axial direction and the shaft 35 slidably move upwards through the insertion hole 37 . Thus, the ball 36 is departed from the valve seat 82 , and the inflow openings 76 are communicated with the outflow opening 78 through the communication hole 80 to open the valve. Thus, the oil-hydraulic fluid flows from the inflow openings 76 to the outflow opening 78 .
When the valve is to be closed, passage of the electric current to the coil 31 is shut off to decay the magnetic circuit. The fixed assembly of the shaft 35 and the plunger 74 slidably moves downwards in the axial direction by the expansion force exerted by the spring 86 to put the ball 36 onto the valve seat 82 . Thus, the communication of inflow openings 76 with the outflow opening 78 is shut off, and the valve is closed.
In Example 17, the present composite magnetic member comprising two ferromagnetized parts 32 a and one non-magnetized part 32 b, as continuously and integrally formed, was employed as the sleeve 32 , and the shaft 35 could be driven under a severe temperature condition without any change in the magnetic characteristics.
In Example 17, the present composite magnetic member is used in an electromagnetic valve for controlling the oil hydraulic line. The present electro-magnetic valve is not limited to electromagnetic valves for controlling the oil hydraulic line, but the present compound magnetic member can be employed, for example, in electromagnetic valves for use in injectors, etc. and in those for controlling a flow rate of a gas, etc. | A metallic member including not more than 0.6% C, 12 to 19% Cr, 6 to 12% Ni, not more than 2% Mn, not more than 2% Mo, not more than 1% Nb and the balance being Fe and inevitable impurities, where
Hirayama's equivalent H eq=[Ni %]+1.05 [Mn %]+0.65 [Cr %]+0.35 [Si %]+12.6 [C %] is 20 to 23%;
Nickel equivalent Ni eq=[Ni %]+30 [C %]+0.5 [Mn %] is 9 to 12%, and
Chromium equivalent Cr eq=[Cr %]+[Mo %]+1.5 [Si %]+0.5 [Nb %] is 16 to 19, wherein % is by weight, is made to have at least one ferromagnetized part having a magnetic flux density B 4000 of not less than 0.3 T and at least one non-magnetized part having a relative magnetic permeability μ of not more than 1.2 at a temperature of not less than −40° C., as continuously and integrally formed. The non-magnetized part has crystal grain sizes of not more than 30 μm. The metallic member is subjected to magnetization and successive local non-magnetization of part or parts of the ferromagnetized member, and the thus obtained composite magnetic member is employed as a support member such as a sleeve in electromagnetic valves. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 325,666, filed on Mar. 20, 1990, entitled "Continuous Miner With Duct Assembly", now U.S. Pat. No. 4,936,632, a continuation in part of application Ser. No. 076,155 filed on June 20, 1989 entitled "Continuous Miner With Duct Assembly", now U.S. Pat. No. 4,840,432.
BACKGROUND OF THE INVENTION
1. Field Of The Invention
This invention relates to a mining machine, and more particularly, to a continuous miner which includes a mobile frame assembly and a boom assembly pivotally secured to the mobile frame assembly by a plurality of connectors which distribute the load placed on the boom assembly as the boom assembly is pivoted upwardly from the mobile frame assembly evenly throughout the boom structure, and to a dust collecting system for collecting airborne particles produced as a material dislodging head mounted on the end of the boom assembly dislodges material from a mine face.
2. Description Of The Prior Art
In underground mining, it is well known to provide a continuous mining machine which includes a material dislodging head positioned on the front end of the mining machine for dislodging material from a mine face. The dislodged material is conveyed rearwardly of the mining machine by a conveying system positioned on the continuous mining machine. The continuous mining is designed to continuously advance and dislodge material being mined to form an entry or tunnel in the material seam.
Various types of continuous mining machines having different types of tilting of pivoting mining heads are known. U.S. Pat. No. 2,986,384 discloses a mining machine having tiltable, dual mining heads. U.S. Pat. Nos. 3,479,090 and 3,495,876 disclose continuous mining machines each having a pivoting structure for supporting a mining head.
U.S. Pat. No. 3,498,676 discloses a continuous mining machine having a mining head that is positioned at the top of the mine face. The mining head is advanced into the mine face and traversed downwardly through the mine face to cut and break the material out of the mine face. The mining machine is supported on traction treads by which the machine is propelled forwardly to advance the mining head into the mine face.
U.S. Pat. No. 3,499,684 discloses a mining machine with a mining head positioned at the forward end of the machine. Traction means propels the mining machine, and gathering means collects the mined material and transfers the material to a conveyor for moving the mined material to the rear of the machine. The mining head is positioned on a boom that is movable upwardly and downwardly about the transverse axis of a pivot support on the machine main frame.
U.S. Pat. No. 3,516,712 discloses a continuous mining machine with a transverse rotary mining head for mining material from the entire area of the mine face by traversing the mining head through the mine face.
U.S. Pat. No. 3,874,735 discloses a continuous mining machine adapted for low overhead coal seams having a relatively small diameter cutter head of the non-oscillating or fixed head type driven by chains that also cut coal and convey it rearwardly to a gathering head mounted on the front of the machine. The gathering head carries a pair of counter-rotating discs having veins cooperating with conveyor fences for sweeping and discharging coal to a conventional conveyor mounted on the machine chassis.
U.S. Pat. No. 3,966,258 discloses a mining machine having a disintegrating head carried on the front end of the machine by a pivotal link arrangement.
In continuous underground mining, it is also known to provide a mining machine which includes a dust collecting system mounted thereon for collecting airborne dust particles produced as the mining machine cutting or dislodging head operates. The dust collecting system provides a relatively clean environment for the mining machine operator.
U.S. Pat. No. 3,712,678 discloses a continuous miner which is provided with a dust collecting system comprising boom-carried ducting adapted to receive dust-entrained air adjacent and rearwardly of the mining head. The mining machine chassis carries ducting which is operable to alternatively discharge the air to opposite sides of the machine. Counter-rotating centrifugal fans mounted in the boom-carried ducting draw dust-entrained air to such ducting whereby the air flows therethrough to the chassis-carried ducting. Scrubbers or cleaners are operatively associated with the boom-carried ducting for removing larger dust particles from the air.
U.S. Pat. No. 3,810,677 discloses a mining machine having a boom enclosed dust collector assembly for use in a coal mining operation wherein the dusty air from a mining operation is gathered directly from the operation, collected in the mining machine boom and selectively wetted and separated by centrifugal processing into a coal slurry for disposal. The clean air is exhausted to atmosphere. The coal slurry is discharged from the mining machine boom through a flexible hose which lies on the ground along a side of the machine.
U.S. Pat. No. 4,380,353 discloses a dust control system for a mining machine comprising a ductwork system having intakes adjacent the cutter head of the mining machine. A fan draws air through the ductwork system, and a flooded bed scrubber in the ductwork system upstream from the fan entrains the dust in droplets of water. The dust laden water is pumped to a point adjacent the cutting head.
U.S. Pat. No. 4,557,524 discloses a continuous mining machine having a dust control system which includes a generally rectangular intake duct section associated with the boom and a generally rectangular fixed duct section mounted on the vehicle. A transition section is connected to the intake of the fixed duct section. The transition section consists of a two piece arrangement wherein each piece is hinged to the intake duct section and is capable of slidingly engaging the fixed duct section at the end thereof adjacent the boom to sealingly couple the intake duct section to the fixed duct section as the boom swings upwardly and downwardly.
Although the prior art continuous mining machines include various types of cutting heads pivotally mounted on the mining machine, there is a need for an improved mining machine having a boom assembly pivotally connected to the mining machine frame assembly by a plurality of connectors which distribute the load on the mining machine boom assembly as it is pivoted upwardly from the mining machine frame assembly evenly throughout the boom assembly structure. Further, there is a need for a simple, efficient dust collecting system whereby dust produced as a dislodging head dislodges material from a mine face is passed through a boom assembly hollow interior portion to a dust collecting system mounted on the mining machine frame. A portion of the boom assembly forms a pivoting joint with a portion of the dust collecting system positioned on the mobile frame assembly to allow airborne dust particles to be withdrawn from the mine face as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
In another embodiment of the invention, two portions of the boom assembly form pivoting joints with portions of the dust collecting system positioned on each side of the mobile frame assembly to allow airborne dust particles to be withdrawn from the mine face as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
Twin ducts of the collecting system meet the boom on each side of the mining machine and extend rearwardly along each side of the mobile frame assembly. One of the twin ducts passes between the conveying reach and the return reach of the conveying system to join with the other duct to allow a single fan to withdraw airborne dust particles from the mine face.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a continuous mining machine for use in an underground mine which includes a mobile frame assembly and a boom assembly extending from the mobile frame assembly. The boom assembly has a first end portion pivotally connected to the mobile frame assembly by a plurality of connecting means and a second end portion spaced from the first end portion. The boom assembly first end portion is pivotally connected to the mobile frame assembly to permit upward and downward pivotal movement of the boom assembly relative to the mobile frame assembly. A material dislodging head is connected to the boom assembly second end portion. The plurality of connecting means are positioned on the boom assembly to distribute the load placed on the boom assembly as it is pivoted upwardly from the mobile frame assembly evenly through the boom assembly structure.
In one embodiment of the invention, the boom assembly has a hollow interior portion with an air inlet portion connected to the hollow interior portion at each boom assembly second end portion and an air outlet portion at the boom assembly first end portion. A collecting means is positioned on the mobile frame assembly. The collecting means induces a flow of air through the boom assembly hollow interior portion. As the dislodging head operates to dislodge material from a mine face, the collecting means draws airborne dust produced by the dislodging head through the hollow interior portion of the boom assembly into the collecting means positioned on the mobile frame assembly. A portion of the boom assembly air outlet portion is pivotally connected to a portion of the mobile frame assembly collecting means to allow the collecting means to continually draw airborne dust from the mine face as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
In another embodiment of the invention, the boom assembly has a hollow interior portion with inlet portions connected to the hollow interior portion at each boom assembly second end portion and air outlet portion at the boom assembly first end portion. A collecting means is positioned on the mobile frame assembly. The collecting means induces a flow of air through the boom assembly hollow interior portion. As the dislodging head operates to dislodge material from a mine face, the collecting means draws airborne dust produced by the dislodging head through the hollow interior portion of the boom assembly into the collecting means positioned on the mobile frame assembly. Two portions of the boom assembly air outlet portions are pivotally connected to portions of the mobile frame assembly collecting means to allow the collecting means to continually draw airborne dust from the mine face as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly. Twin ducts of the collecting system meet the boom assembly on each side of the mining machine and the ducts of the collecting system extend rearwardly along each side of the mobile frame assembly. The first duct assembly extends longitudinally along the first side of the mobile frame assembly. The second duct assembly extends longitudinally along part of the second side of the mobile frame. The second duct assembly then traverses the mobile frame by means of a cross-over portion that passes between the conveying reach and the return reach of a conveying means to join with the first duct assembly. Each duct assembly opposite end portion is in fluid communication with the boom assembly hollow interior portions in all positions that the boom assembly pivots upwardly and downwardly so that a single fan may be used to draw airborne dust through the system.
The continuous mining machine further includes the conveying system which extends longitudinally through the center of the mining machine. The conveying system includes a longitudinal first section which extends from the front end of the mobile frame assembly to the rear end of the mobile frame assembly. The conveying system also includes a conveyor second section pivotally connected to the conveyor first section which extends rearwardly from the rear end of the mobile frame assembly. The conveyor second section is pivotally connected to the conveyor first section for selected lateral and vertical movement relative to the conveyor first section. Material removed from the mine face by the dislodging head is transferred rearwardly of the mining machine along the conveyor system first and second sections by a plurality of spaced flights. The conveyor second section is pivoted relative to the conveyor first section to deposit dislodged material at predetermined locations rearwardly of the mining machine.
Accordingly, the principal object of the present invention is to provide a continuous mining machine which includes a boom assembly pivotally connected to the mining machine mobile frame assembly by a plurality of connecting means.
Another object of the present invention is to provide a continuous mining machine having a boom assembly pivotally connected to a mobile frame assembly by a plurality of connecting means suitably positioned on the boom assembly to distribute the loading created on the boom assembly as the boom assembly is pivoted upwardly relative to the mobile frame assembly evenly throughout the boom assembly structure.
A further object of the present invention is to provide a continuous mining machine which includes a dust collecting system positioned on the mobile frame assembly for inducing a flow of air through a hollow interior portion of the boom assembly as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
A further object of the present invention in one of its embodiments is to provide a continuous mining machine which includes a dust collecting system with one fan and twin ducts positioned on the mobile frame assembly for inducing a flow of air through two hollow interior portions of the boom assembly as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
Still another object of the present invention is to provide a continuous mining machine which includes a conveying system longitudinally positioned on the mobile frame assembly to receive material dislodged from a mine face by a dislodging head and transfer the dislodged material rearwardly from the mine face.
These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of one embodiment of a self-propelled continuous mining machine which is the subject of this invention.
FIG. 2 is a view in side elevation of the continuous mining machine shown in FIG. 1, illustrating a boom assembly having a dislodging head secured thereto resting on a mine floor, and illustrating in phantom the boom assembly pivoted upwardly relative to the mining machine to show the extent of travel of the boom assembly.
FIG. 3 is a top plan view of one embodiment of a boom assembly, illustrating in phantom the boom assembly connections to the mining machine.
FIG. 4 is a partial fragmentary view in side elevation of the boom assembly shown in FIG. 3, illustrating a pivoting joint connection which is the subject of this invention.
FIG. 5 is a top plan view of a second embodiment of a self-propelled continuous mining machine which is the subject of this invention.
FIG. 6 is a view in side elevation of the continuous mining machine shown in FIG. 5, illustrating a boom assembly having a dislodging head secured thereto adjacent the mine floor, and illustrating in phantom the boom assembly pivoted upwardly relative to the mining machine to show the extent of travel of the boom assembly.
FIG. 7 is a top plan view of a second embodiment of a boom assembly, illustrating in phantom the boom assembly connections to each side of the mobile frame assembly of the mining machine.
FIG. 8 is a partial fragmentary view in side elevation of the boom assembly shown in FIG. 7, illustrating a pivoting joint connection which is the subject of this invention, and illustrating in phantom the boom assembly pivoted upwardly relative to the mining machine to show the operation of the pivoting joint connection.
FIG. 9 is a fragmentary cross section of the conveying system showing the cross-over portion of the second duct assembly passing between the conveying reach and the return reach of the conveying system.
FIG. 10 is a fragmentary sectional view taken along line X--X of FIG. 9 showing a portion of the cross-over duct.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and particularly to FIGS. 1, 2, 5, and 6, there is illustrated a continuous mining machine generally designated by the numeral 10 for use in an underground mine to dislodge material from a mine face. Continuous mining machine 10 includes a mobile frame assembly 12 and a pair of ground engaging traction means 14 (one shown in FIGS. 2 and 6) positioned at each side of mobile frame assembly 12 for propelling mining machine 10 within a mine 16 along the floor 18 thereof.
Continuous mining machine 10 is capable of being operated from an operating station 20 in a manner similar to other such machines to dislodge material from a mine face 36 and transport it rearwardly of the rear end 46 of mining machine 10. Accordingly, mining machine 10 includes operating controls and sources of power for operating ground engaging traction means 14 and other equipment included thereon.
Mining machine 10 includes a boom assembly 22 having a first end section 24 pivotally secured to the front end 26 of mobile frame assembly 12. Boom assembly 22 also includes a second end section 28. As seen in FIGS. 1, 2, 5, and 6, a material dislodging head generally designated by the numeral 30 is connected to boom assembly 22 second end section 28. Although a material dislodging head such as dislodging head 30 is illustrated in the figures, it should be understood that any desired dislodging head 30 known in the art may be secured to boom assembly 22 second end section 28.
Boom assembly 22 also includes four longitudinally extending engaging plates 32 which extend rearwardly from boom assembly 22 first end section 24 to engage four generally U-shaped retainers 34 secured to the front end 26 of mobile frame assembly 12. Boom assembly 22 engaging plates 32 are pivotally secured to the mobile frame assembly 12 generally U-shaped retainers 34 to allow boom assembly 22 to be pivoted upwardly and downwardly relative to mobile frame assembly 12. In this manner, as boom assembly 22 is pivoted upwardly and downwardly relative to mobile frame assembly 12, dislodging head 30 may be operated to dislodge material from a face 36 of the mine 16.
Although not specifically illustrated in the figures, actuating cylinders, preferably hydraulic cylinders, are connected at one end to front end 26 of mobile frame assembly 12. The other ends of the actuating cylinders are connected to retainers 38 (one shown in FIGS. 4 and 8) on boom assembly 22. As the actuating cylinders extensible rod portions are extended outwardly from their respective cylinder bodies, boom assembly 22 pivots vertically relative to mobile frame assembly 12 to allow dislodging head 30 to dislodge material from the full vertical surface of mine face 36. As seen in FIGS. 2 and 6, since boom assembly 22 is pivotally connected to mobile frame assembly 12, boom assembly 22 travels in an arcuate path between mine floor 18 and mine roof 40 as dislodging head 30 dislodges material from mine face 36. As also seen in FIGS. 2 and 6, boom assembly 22 is capable of downward arcuate movement to allow dislodging head 30 to travel below the surface of mine floor 18.
As illustrated in phantom in FIGS. 2 and 6, since boom assembly 22 is pivotally secured to mobile frame assembly 12, boom assembly 22 travels in an arcuate path from a point beneath mine floor 18 to mine roof 40. As boom assembly 22 pivots upwardly towards mine roof 40, the weight of boom assembly 22 and dislodging head 30 creates torsional loading on the four pivot pins (shown in FIGS. 3 and 7) which secure boom assembly 22 engaging plates 32 to mobile frame assembly 12 generally U-shaped retainers 34. However, since boom assembly 22 is pivotally connected to mobile frame assembly 12 by four engaging plates 32, this four point connection allows the torsional loading created as boom assembly 22 and dislodging head 30 are pivoted upwardly towards mine roof 40 to be evenly spread through boom assembly 22. This four point connection reduces the wear on the pivot pins and provides a sturdy connection between boom assembly 22 and mobile frame assembly 12.
In the embodiment of FIGS. 1-4, mining machine 10 also includes a dust collecting system generally designated by the numeral 42. Dust collecting system 42 is operable to remove airborne particles produced as dislodging head 30 dislodges material from mine face 36 to provide a clean working environment for the mining machine 10 operator. Dust collecting system 42 includes a fan assembly 44 mounted on mobile frame assembly 12 at the rear end 46 of mining machine 10. Dust collector 50 is also positioned on mobile frame assembly 12 and is connected to fan assembly 44. Duct assembly 48, which runs longitudinally along mobile frame assembly 12, has an end portion connected to a dust collector 50 and an opposite end portion which extends between a pair of generally U-shaped retainers 34 on mobile frame assembly 12. As will be explained later, duct assembly 48 includes a top wall 49 and a bottom wall 51 each having formed, arcuate end sections. As will also be explained later and illustrated in FIG. 4, boom assembly 22 includes a hollow interior portion 78 and an air inlet 52 which form part of dust collecting system 42. A portion of boom assembly 22 forms a pivoting joint with the formed, arcuate end sections of duct assembly 48 top wall 49 and bottom wall 51.
As dislodging head 30 operates to dislodge material from mine face 36, fan assembly 44 draws airborne dust produced by dislodging head 30 into boom assembly 22 air inlet portion 52 and through the hollow interior 78 of boom assembly 22 into duct assembly 48 positioned on mobile frame assembly 12. The dust which passes through duct assembly 48 is collected in dust collector 50. Dust collecting system 42 withdraws airborne dust from the area adjacent mine face 36 for the safety of the mining machine 10 operator. The pivoting point formed duct assembly 48 and boom assembly 22 allows collecting system 42 to draw airborne dust away from mine face 36 as boom assembly 22 is pivoted upwardly and downwardly on mobile frame assembly 12.
In the embodiment of FIGS. 5-10, mining machine 10 includes a dust collecting system also generally designated by the numeral 42. Dust collecting system 42 is operable to remove airborne particles produced as dislodging head 30 dislodges material from mine face 36 to provide a clean working environment for the mining machine 10 operator. Dust collecting system 42 includes a fan assembly 44 mounted on mobile frame 12 at the rear end 46 of mine machine 10. A dust collector 50 is also positioned on mobile frame assembly 12 and is connected to fan assembly 44. A duct assembly generally designated by the numeral 48 includes first duct assembly 47, which runs longitudinally along mobile frame assembly 12, has an end portion connected to a dust collector 50 and an opposite end portion which extends between a pair of generally U-shaped retainers 34 on mobile frame assembly 12 and includes second duct assembly 90. On the opposite side of mobile frame 12 from first duct assembly 47 the second duct assembly 90 runs longitudinally partially along mobile frame assembly 12 to a traverse cross-over portion 92 extending between the conveying reach 59 and the return reach 61 (shown in FIG. 10) of conveyor deck 60 where the end portion 94 of second duct assembly 90 interconnects with first duct assembly 48.
As will be explained later in greater detail, first duct assembly 48 and second duct assembly 90 each include a top wall 49 having formed, arcuate end section 85 and a bottom wall 51 having a formed, arcuate end section 87 that are connected to a pair of vertically extending side walls 91 (shown in FIG. 9). As will be explained later in greater detail and illustrated in FIG. 8, boom assembly 22 includes a hollow interior portion 78 and an air inlet 52 which forms a part of dust collecting system 42. Two portions of boom assembly 22 form sliding joints 41 with the formed, arcuate end sections 85, 87 of first duct assembly 48 top wall 49 and bottom wall 51 and with the formed, arcuate end sections 85, 87 of second duct assembly 90 top wall 49 and bottom wall 51. This allows airborne dust to pass between joint space 89 located between the ends of formed, arcuate end section 85 and the formed, arcuate end section 87.
As dislodging head 30 operates to dislodge material from mine face 36, fan assembly 44 draws airborne dust produced by dislodging head 30 into boom assembly 22 air inlet portion 52 and through the hollow interior 78 of boom assembly 22 into first duct assembly 47 and second duct assembly 90 positioned on opposite ends of mobile frame assembly 12. The dust which passes through first duct assembly 47 is collected in dust collector 50. The dust which passes through second duct assembly 90 then passes through cross-over portion 92 to end portion 94 and therethrough to first duct assembly 48 where the duct is collected in dust collector 50. As described, dust collecting system 42 withdraws airborne dust from the area adjacent mine face 36 for the safety of the mining machine 10 operator. Sliding joints 41 formed from first duct assembly 47 and boom assembly 22 and from second duct assembly 90 and boom assembly 22 allow collecting system 42 to draw airborne dust away from mine face 36 as boom assembly 22 is pivoted upwardly and downwardly on mobile frame assembly 12.
In both embodiments of the invention, mining machine 10 also includes a conveyor system generally designated by the numeral 54. Conveyor system 54 extends longitudinally from the front end 26 of mobile frame assembly 12 to a location rearwardly of the rear end 46 of mobile frame assembly 12. Conveyor system 54 includes a conveyor first section 56 which extends longitudinally through the center of mobile frame assembly 12. Conveyor system 54 also includes a conveyor second section 58 which extends rearwardly to the rear end 46 of the mobile frame assembly 12 and is pivotally connected to the conveyor first section 56 for lateral movement relative to conveyor first section 56. In this manner, conveyor second section 58 can be suitably positioned to deposit material provided to conveyor system 54 by dislodging head 30 at a preselected location rearwardly of rear end 46 of mining machine 10. Further, as illustrated in phantom in FIGS. 2 and 6, conveyor second section 58 may be inclined to conveyor first section 56 if it is desired to deposit the dislodged material into a receiver. Conveyor first and second sections 56, 58 include a common conveyor deck 60 having track 107 which rotates by conventional means over a conveying reach 59 above and a return reach 61 below common conveyor deck 60. A plurality of spaced flights 62 transports material dislodged by dislodging head 30 over conveying reach 59 rearwardly of the rear end 46 of mining machine 10 along the common conveyor deck 60 of conveyor first section 56 and conveyor second section 58.
As seen in FIGS. 2 and 6, mining machine 10 also includes a stabilizer 64 which is pivotally connected to mobile frame assembly 12. Before mining machine 10 commences operation to dislodge material for mine face 36, stabilizer 64 is extended downwardly to contact mine floor 18. As boom assembly 22 and dislodging head 30 are pivoted vertically relative to mobile frame assembly 12 to dislodge material from mine face 36, stabilizer 64 operates to stabilize the rear end 46 of mining machine 10 to prevent vertical movement of the rear end 46 of mining machine 10.
Referring to FIGS. 3, 4, 7, and 8, there is illustrated boom assembly 22 previously described. Boom assembly 22 includes a generally transverse front wall 66 and a pair of generally longitudinally extending outer side walls 68 connected to a transverse front wall 66. Generally longitudinally extending outer side walls 68 each include a bent portion 69 which provides clearance for dislodging head 30 drive motors 71.
Boom assembly 22 also includes a horizontally extending top wall 72 and a horizontally extending bottom wall 74. Horizontally extending top wall 72 and horizontally extending bottom wall 74 are connected between the generally longitudinally extending outer side walls 68. Horizontally extending top and bottom wall 72, 74 are also connected to transverse front wall 66.
As seen in FIGS. 3 and 7, horizontally extending top wall 72 and horizontally extending bottom wall 74 each include a generally U-shaped cutout 76. The generally U-shaped cutouts 76 and horizontally extending top wall 72 and horizontally extending bottom wall 74 provide clearance for conveyor first section 56 which passes longitudinally through the center of mobile frame assembly 12.
A pair of longitudinally extending inner side walls 70 are connected between horizontally extending top wall 72 and horizontally extending bottom wall 74 as shown in FIGS. 3 and 7. As seen, the arrangement of generally longitudinally extending outer side walls 68, longitudinally extending inner side walls 70, transverse front wall 66 and horizontally extending top and bottom walls 72, 74 provide boom assembly 22 with the hollow interior 78 previously described.
As seen in FIGS. 3 and 7, the pair of generally longitudinally extending outer side walls 68 include a pair of outer side wall plates 32 arranged to be received by a pair of generally U-shaped retainers 34 secured on mobile frame assembly 12 and illustrated in phantom. Similarly, the pair of longitudinally extending inner side walls 70 include a pair of inner side wall plates 32 arranged to be received by another pair of generally U-shaped retainers 34 secured on mobile frame assembly 12 and illustrated in phantom. Outer side wall plates 32 and inner side wall plates 32 represent the engaging plates 32 previously described.
Outer side wall plates of engaging plates 32, inner side wall plates of engaging plates 32 and the four generally U-shaped retainers 34 each include aligned holes to receive four pivot pins 84. As earlier described, boom assembly 22 pivots upwardly and downwardly about pivot pins 84 as the actuating means (not shown) operates to raise and lower boom assembly 22 relative to mobile frame assembly 12. This four pivot pin arrangement evenly distributes the torsional loading placed on boom assembly 22 as boom assembly 22 and dislodging head 30 are pivoted upwardly relative to mobile frame assembly 12. Since the torsional loading is evenly distributed throughout the four pivot pins 84, frictional wearing on each pivot pin 84 is reduced, and the frictional wearing on the pivot pin receiving holes in outer side wall plates of engaging plates 32 and inner side wall plates of engaging plates 32 is also reduced.
In one embodiment of the invention, referring to FIG. 4, there is illustrated the pivoting joint previously described. The pivoting joint is generally designated by the numeral 57. Horizontally extending top wall 72 and horizontally extending bottom wall 74 include formed, arcuate ends 86, 88, respectively, positioned between a pair of generally U-shaped retainers 34 illustrated in FIG. 3.
As earlier described, collecting system 42 duct assembly 48 includes duct top wall 49 and duct bottom wall 51 having formed, arcuate ends 53, 55, respectively. As seen in FIG. 4, horizontally extending top wall 72 and horizontally extending bottom wall 74 arcuate ends 86, 88 contact the inner surfaces of arcuate ends 53, 55 of each duct top wall 49 and each duct bottom wall 51, respectively, to form pivoting joint 57 between boom assembly 22 and duct assembly 48.
As boom assembly 22 is pivoted upwardly or downwardly relative to mobile frame assembly 12, arcuate ends 86, 88 pivotally contact the inner surfaces of duct assembly 48 arcuate ends 53, 55 to provide pivoting joint 57. In this manner, as fan assembly 44 operates to draw airborne dust produced by dislodging head 30 through air inlet 52 and boom assembly 22 hollow interior 78, the dust passes through pivoting joint 57 formed by arcuate ends 86, 88 and arcuate ends 53, 55 into duct assembly 48. As boom assembly 22 is raised and lowered relative to mobile frame assembly 12 to allow dislodging head 30 to remove material from the full vertical surface of mine face 36, the dust produced by dislodging head 30 is passed through the hollow interior 78 of boom assembly 22 into duct assembly 48 by means of pivoting joint 57. As seen, collecting system 42 can operate to withdraw airborne dust from mine face 36 regardless of the position of boom assembly 22 relative to mobile frame assembly 12. As described, the pivoting joint 57 formed by arcuate ends 86, 88 and arcuate ends 53, 55 eliminates the need for flexible or telescoping duct connections between duct assembly 48 and boom assembly 22.
In a second embodiment of the invention, referring to FIG. 8, there is illustrated the sliding joint previously described. The sliding joint is generally designated by the numeral 41. Horizontally extending top wall 72 and horizontally extending bottom wall 74 include formed, arcuate ends 73, 75, respectively, positioned between a pair of generally U-shaped retainers 34 illustrated in FIG. 7.
As earlier described, collecting system 42 first duct assembly 47 and second duct assembly 90 each include duct top wall 49 and duct bottom wall 51 having formed, arcuate ends 85, 87, respectively. As seen in FIG. 8, horizontally extending top wall 72 and horizontally extending bottom wall 74 arcuate ends 73, 75 contact the inner surfaces of arcuate ends 85, 87 of each duct top wall 49 in each duct bottom wall 51, respectively, to form sliding joint 41 between boom assembly 22 and first duct assembly 47 and between boom assembly 22 and second duct assembly 90. As shown, arcuate ends 85, 87 do not interconnect leaving joint space 89 to allow for the passage of airborne dust between the hollow interior 78 of boom assembly 22 and mobile frame assembly 12 first duct assembly 47 and second duct assembly 90.
As boom assembly 22 is pivoted upwardly or downwardly relative to the mobile frame assembly 12, arcuate ends 73, 75 slidingly contact the inner surfaces of first duct assembly 47 and second duct assembly 90 arcuate ends 85, 87 to provide sliding joint 41. In this manner, as fan assembly 44 operates to draw airborne dust produced by dislodging head 30 through air inlet 52 and boom assembly 22 hollow interior 78, the dust passes through joint space 89 of sliding joint 41 formed by arcuate ends 73, 75 and arcuate ends 85, 87 into first duct assembly 47 and second duct assembly 90. As boom assembly 22 is raised and lowered relative to mobile frame assembly 12 to another dislodging head 30 to remove material from the full vertical surface of mine face 36, the dust produced by dislodging head 30 is passed through the hollow interior 78 of boom assembly 22 into first duct assembly 47 and second duct assembly 90 through joint space 89 by means of sliding joint 41. As seen, collecting face 42 can operate to withdraw airborne dust from mine face 36 regardless of the position of boom assembly 22 relative to mobile frame assembly 12. As described, the sliding joint 41 formed by arcuate ends 73, 75 and arcuate ends 85, 87 eliminate the need for flexible or telescoping duct connections between boom assembly 22 and between first duct assembly 47 and second duct assembly 90, respectively.
There is also retaining wall 97 which is pivotally fastened by conventional means to mobile frame assembly 12 by mobile frame assembly fastener 96 and to boom assembly 22 by boom assembly fastener 98. Retaining wall 97 pivotally moves in an arcuate direction as boom assembly 22 is moved upwardly and downwardly and provides extra support to the connection between boom assembly 22 and mobile frame assembly 12.
As described previously, second duct assembly 90 traverse cross-over portion 92 passes between conveying reach 59 and return reach 61 of conveyor first section 56 to end portion 94 where it connects with first duct assembly 47. Portions of both interior walls of mobile frame assembly 12 are cut open (as shown in FIG. 5) to receive cross-over portion 92 of second duct assembly 90.
Referring to FIG. 9, there is illustrated a fragmentary cross section of conveyor first section 56 and traverse cross-over portion 92 of second duct assembly 90. Conveyor first section 56 includes conveying reach 59 with bottom portion 100 positioned above return reach 61 with top portion 102 with hollow conveyor interior of first section 104 positioned therebetween. Cross-over portion 92 of second duct assembly 90 is positioned in hollow conveyor interior 104 between bottom portion 100 of conveying reach 59 and top portion 102 of return reach 61. Cross-over portion 92 of second duct assembly 90 includes a horizontal top wall 49 and a horizontal bottom wall 51. Horizontally extending top wall 49 and horizontally extending bottom wall 51 are connected between the vertically extending side walls 91 to provide for a hollow cavity 93 surrounded by top wall 49, bottom wall 51 and side walls 91. This hollow cavity facilitates the withdrawal of airborne dust from mine face 36 to dust collector 50.
Referring to FIG. 10, a transverse cross section of cross-over portion 92 of second duct assembly 90 and conveyor first section 56 is taken along line X--X of FIG. 9. Return reach 61 includes horizontal top portion 102 and horizontal bottom portion 108 which encloses the track 107 and spaced flights 62 of return reach 61. Horizontal top portion 102 and horizontal bottom portion 108 of return reach 61 are connected to vertically extending side walls 106 which extend beyond the top portion 102 of return reach 61 to bottom wall 51 of crossover portion 92. Conveying reach 59 includes horizontal bottom portion 100 extending below track 107 and spaced flights 62 connecting to vertically extending side walls 110. Vertical side walls 110 extend below bottom portion 100 of conveying reach 59 to top wall 49 of cross-over portion 92. Vertical side walls 110 and vertical side walls 106 wedge in top wall 49 and bottom wall 51 of cross-over portion 92 of second duct assembly 90, respectively, to provide stability for cross-over portion 92 of second duct assembly 90 while mobile frame assembly 12 is in all modes of operation.
According to the provisions of the Patent Statutes, we have explained the principle, preferred construction and mode of operation of our invention and have illustrated and described what we now consider to represent its best embodiments. However, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described. | A self-propelled continuous mining machine includes a mobile frame assembly having a front end portion with a boom assembly pivotally retained thereon. A dust collecting system is positioned on the mobile frame assembly for inducing a flow of air through a hollow interior portion of the boom assembly. As a dislodging head removes material from a mine face, the dust collecting system draws airborne dust created by the dislodging head through a hollow interior of the boom assembly and into the collecting system mounted on the mobile frame assembly. Two portions of the boom assembly are pivotally connected to portions of the collecting system mounted on the mobile frame assembly to provide pivoting joints to allow the collecting system to draw airborne dust through the boom assembly with the boom assembly in any preselected position relative to the mobile frame assembly. Twin ducts of the collecting system meet the boom on each side of the mining machine and the ducts of the collecting system extend rearwardly along each side of the mobile frame assembly. A conveying system mounted on the mobile frame assembly receives material from the dislodging head and transports the material rearwardly of the machine. One of the twin ducts crosses to the other side of the mobile frame by passing between the conveying reach and the return reach of the conveying system and joins with the other duct so that a single fan may be used to draw airborne dust through the system. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to a method of producing optical polymer components having integrated vertical coupling structures, wherein the optical polymer components have regions for receiving light waveguides and fiber guide structures, preferably configured as V-shaped positioning trenches, for receiving optical fiber structures to be coupled to the light waveguides, and the polymer components comprise a polymer substrate and a polymer lid plate. More particularly, the present invention relates to a method of producing optical polymer components, as mentioned above, having integrated vertical coupling structures, and which is used in the mass-production of monomode or multimode components, particularly opto-optical components, of integrated optics having monolithically-integrated fiber-chip coupling.
The increasing use of integrated-optical components for optical communications, for sensory technology and the computer field (optical databus) lends ever-increasing significance to optical connection techniques (chip-fiber coupling) and optical coupling techniques. Smaller, private relay stations having approximately 1000 subscriber stations already require, for example, several thousand optical connections and coupling stations between the individual sub-switching stages, because the number and complexity of the optical components integrated on individual substrates are severely limited due to the extreme aspect conditions in the optics. In such cases the reliability (mechanic and thermal stability) and ability of the optical connection and coupling technology to be realized, and the required connection expenditure ultimately determine the achievable degree of expansion of an optical relay system.
The basic mode of operation of vertical directional couplers is known in which two light waveguides disposed one above the other approach one another so closely over a defined length that a coupling occurs between them and energy can be exchanged. Usually such components are structured in stacked, thin films (film waveguides), with the layer lying between the waveguides determining the coupling strength of the waveguides with its optical thickness. The homogeneity of this intermediate layer is therefore critical for the operation of such components, and technologically difficult to control. Moreover, up to now neither self-adjusting optical connection techniques for such waveguides located at different heights, nor mass-producibilty of such components using an injection-molding technique has been possible.
In known parallel strip couplers, typically coplanar waveguides must be guided precisely adjacently in the coupling region with a few μm lateral spacing over a few hundred μm coupling length. Such structures are difficult to realize using injection-molding techniques, because very narrow webs for the waveguides would have to be produced between trench structures.
So-called imprinting techniques for monomode light waveguides in plastics ("embossing" or photopolymerization) are known from H. Hosokawa et al in the Integrated Photonics Research Conf., (1991). However, neither an arrangement of waveguides one above the other nor the simultaneous production of a substrate-integrated fiber guidance is possible in this technique.
Furthermore, it is known from A. Neyer et al in the Integrated Photonics Research Conf., (1992) to shape waveguide structures in a substrate and then fill this with a light-guiding polymer having a high refractive index. In this instance waveguides can only be created on one side in a substrate layer, but an arrangement of waveguide coupling structures one above the other is excluded.
Moreover, the principle of duplicating microstructures using galvanic shaping and injection-molding is known as the so-called "LIGA" technique. In this technique the primary structures to be shaped are usually created by means of X-irradiation of plastics on a synchrotron, and from there the mold inserts for the injection molding are galvanically produced. An alternating arrangement of higher-lying and lower-lying fiber guide structures, as become necessary for vertical coupling elements, is not possible according to the current state of the LIGA technology, because the necessary X-irradiation principally permits no depth resolution.
SUMMARY AND ADVANTAGES OF THE INVENTION
In contrast, the method of the invention, according to the characteristics of the main claim, offers the advantage that a mass-scale production of polymer components having integrated vertical coupling structures with high coupling precision is possible in a simple manner.
According to the present invention, both passive as well as opto-optically active or acousto-optical components of the integrated optics can be mass-produced with monolithically-integrated fiber-chip coupling.
For this purpose, according to the basic concept of the invention, it is provided that respectively at least one structure for receiving a light waveguide and respectively at least two fiber guide structures, as well as respectively at least two adjusting structures, are produced on the substrate plate and on the lid plate in such a way that both the substrate plate and the lid plate possess fiber guide structures with which the adjusting structures located opposite in the substrate plate or lid plate are associated after assembly, and the light waveguide structures of the substrate plate and the lid plate which connect the fiber guide structures extend parallel to each other in at least one region.
Further advantageous embodiments ensue from the measures disclosed in the dependent claims.
Using known anisotropic etching techniques of the silicon, in a simple manner V-shaped trench structures are etched into {100} oriented wafers which create the substrate plate and the lid plate, resulting in a highly-precise structure by way of which the later exact position of glass fiber structures and waveguide structures with respect to one another is defined.
Such a V-groove is particularly suited as a fiber guide structure and adjusting structure, because the angular adjustment, parallel to the crystal surface, is automatically set, and the height position of the fiber core can be set exactly over the wafer surface by way of the opening width of the V-groove and controlled using production techniques.
In an advantageous manner, the V-grooves are filled with polymer materials, and the resulting planar surface is subsequently coated with a photoresist or another polymer that can be structured. Trench-shaped openings that define the dimensions of the later light waveguides are structured into the cover layer in this manner.
Moreover, the V-grooves are subsequently re-opened by means of excimer laser ablation techniques known per se, and in a particularly advantageous manner, vertical fiber structure stops are cut at the end of the V-grooves on the side of the light waveguide.
In a further advantageous embodiment of the invention, it is provided that the master structures are shaped from light waveguide structures and integrated fiber guide structures and adjusting structures by means of galvanization methods known per se.
The negative form resulting in this manner is used to produce numerous daughter copies of the master structure. This is advantageously effected by means of injection-molding or injection-embossing methods in the polymer material.
According to the invention, the trench-shaped openings, later forming the light waveguides, are structured such that they respectively connect two fiber guide structures located opposite one another in the substrate plate or lid plate, and have at least one region in which, after assembly, the opening for the substrate plate-side light waveguide extends vertically spaced and parallel to the opening for the lid plate-side light waveguide.
Because of the intrinsic design of the component with vertical coupling structures instead of coplanar, adjacent coupling arms (the usual embodiment of directional coupling components), it is particularly possible to pour different materials into the upper and lower openings which form the light waveguides. Because of this, for example, undesirable damping losses of a particular opto-optically active material in the other optical connection plane can be avoided, or separate switching effects can be achieved above and below (polymer substrate plate and polymer lid plate) by means of control light beams of different wavelengths. The control light can also principally be guided in the same light waveguide (fiber) as the signal light to be switched.
In an advantageous manner, a method has been proposed for mass-production-capable design of different polymer components having vertical coupling structures, which are considered both for passive components, such as, for example, 2×2-directional couplers or star couplers/power dividers, and optically-controlled optical switching elements having a two-layer optical design. Particularly advantageous is the chip-integrated, simultaneous production of fiber guide structures for a self-adjusting optical contacting of the coupling components on two different planes.
Moreover, the self-adjusting adjustment technique in the assembly of the components is advantageous, in which not only the fibers are passively adjusted to the light waveguides, but the polymer lid and bottom plates (substrate plates) also "lock in place" to fit perfectly with one another. Because of the vertical arrangement of the light waveguides, the coupling distance of all components of a chip can be easily controlled technologically by the thickness of the worked-in polymer film.
The ability of different core polymers to be freely combined in the lower and the upper plane of the component can have many applications; for example, at least one of the polymers is doped with X.sup.(3) materials in order to obtain optical switching functions.
Also in an advantageous manner, the inserted polymer film itself can effect a switching function in that acousto-optical effects, for example in a piezoelectric film (PVDF film), lead to an adaptation of the expansion constants of the light in differently-dimensioned light waveguides below and above, and thus trigger a switching behavior of the couplers induced by acoustic phonon absorption.
BRIEF DESCRIPTION OF THE DRAWING
Embodiments of the invention are represented in the drawings and described in detail in the following description wherein:
Shown are in:
FIG. 1 is a cross-section of a master structure for a fiber guide structure;
FIG. 2 is a side view according to FIG. 1;
FIG. 3 is a negative form for a fiber guide structure;
FIG. 4 is a side view according to FIG. 3;
FIG. 5 is a section of a polymer component produced with a negative form represented in FIGS. 3 and 4;
FIG. 6 is a side view according to FIG. 5;
FIG. 7 is a projectional top view of a complete polymer component;
FIG. 8 is a section along line A--A from FIG. 7;
FIG. 9 is a section along line B--B from FIG. 7;
FIG. 10 is a section along line C--C from FIG. 7;
FIG. 11 is a coupling structure in detail;
FIG. 12 is a projectional top view of a further polymer component, and,
FIG. 13 is a projectional top view of aa further polymer component.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The master structure illustrated in FIGS. 1 and 2 is intended to clarify the integrated fiber-chip coupling of a polymer component 10 (FIG. 7) by way of example. In fact, a number of fiber-chip couplings are disposed on each polymer component. The fiber-chip coupling is, however, essentially a precondition for the later-described, actual vertical coupling structure.
The master structure--here represented on the side of the substrate plate--comprises a silicon substrate 12, into which a fiber guide structure 14 (positioning trench) having a V-shaped cross-section is anisotropically etched in order to receive a glass fiber not shown here.
By means of the anisotropic etching techniques of the silicon, which are known per se, V-shaped trench structures can be etched into the {100} oriented wafer, with the depth of these trenches being set as a function of the width of a rectangular opening w in the etching mask parallel to the <110> direction. The inclined {111} side surfaces forming create a natural etching stop defined by the anisotropic etching properties of the crystal. Such a V-groove is particularly suited as a fiber guide structure 14, because the angular adjustment (parallel to the crystal surface) is set automatically, and the height position δ of the fiber core can be set exactly above the wafer surface by way of the opening width of the V-groove, and can be controlled with production technology.
The following relationship applies for the later height position of the fiber core: ##EQU1## with R=fiber jacket diameter (typ. 125 μm), α=angle of inclination of the {111} surfaces in relation to the wafer surface (α=54.7356°), w=width of the V-groove at the wafer surface. A change in Δ w=1 μm results in a change in the height position Δδ=0.7 μm.
After etching of the V-grooves in silicon, these are planated (filled to be planar) with polymer materials 16, so that a planar surface 18 results for the subsequent coating with photoresist or another polymer 20 that can be structured. Structured into this cover layer 20 of a thickness s are trench-shaped openings 22 which define the dimensions of the later light waveguides (the height position of the fiber core above the wafer surface in this example would have to be δ=3 μm, so that the optical axes of light waveguides and glass fibers are aligned) and which have typical dimensions of 6 μm×6 μm cross-section surface (=structure width×layer thickness s).
The fiber guide structures 14 are subsequently partially re-opened, preferably by means of excimer laser ablation technique, and a vertical fiber stop 24 is thereby cut at the end of the V-groove on the side of the light waveguide. This technique permits a guidance of the light waveguides in the openings 22 beyond the diagonal end surfaces of the V-grooves to a vertically-cut stop, so that optical fibers (glass fibers) and light waveguides can be coupled with one another directly end-to-end.
The lateral adjustment of the light waveguides adjoining the fibers can be achieved with sufficient precision using conventional techniques of photolithography.
According to FIGS. 3 and 4, this master structure of light waveguide prestructures (opening 22) and integrated fiber guide structures 14 is shaped on silicon using conventional galvanic methods, so that a negative form 26, for example of nickel, is created. The negative form 26 has a region 28 that imitates the fiber guide structure 14, and a region 20, which imitates the opening 22. With this negative form 26, numerous daughter copies of the master structure can be produced in the polymer material (e.g. PMMA or polycarbonate) by means of injection-molding or injection-embossing methods.
As already mentioned, in the example only one fiber guide structure 14 of a polymer substrate plate is described in detail. The finished polymer component 10, however, possesses a number of fiber guide structures 14, and the openings 22 which later form the light waveguides. Furthermore, the component 10 has a polymer lid plate 34, in which fiber guide structures 14 and openings 22 are likewise disposed. Both the polymer substrate plate 32 and the polymer lid plate 34 likewise have adjusting structures 36. The adjusting structures 36 are disposed exactly opposite a fiber guide structure 14 after assembly.
The adjusting structures 36 are anisotropically etched in the same, already-described manner as the fiber guide structures 14, preferably in V-shape.
A complete master structure is respectively produced for a polymer substrate plate 32 and a polymer lid plate 34. The layout, that is, the position of fiber guide structures 14, adjusting structures 36 and openings 22, is oriented toward the later design of the complete polymer component 10.
A fiber-chip coupling point 38 of a completed polymer component 10 is shown in its entirety in FIGS. 5 and 6.
The coupling point 36 comprises a fiber guide structure 14 disposed in the substrate plate 32, and a light waveguide 40 poured into the openings 22. The fiber guide structure 14 is allocated an adjusting structure 36 in the lid plate 34. An optical buffer film 42 is provided between lid plate 34 and substrate plate 32. The glass fiber, not shown here, lies in the recess 44 which results when the lid plate 34 is placed on top, and is aligned with its optical axis in that the fiber guide structure 14 is configured lower than the adjusting structure 36, with the optical axis of the light waveguide 40 disposed in the substrate plate 32. Details regarding the low embodiment of the structures 14 and 36 and the thickness of the buffer film 42 are given further below.
FIG. 7 shows a projectional top view of a polymer component 10 configured as a 2×2-directional coupler.
Polymer substrate plate 32 and lid plate 34 (not shown here) each have fiber guide structures 14 (V-grooves), adjusting structures 36 and waveguide prestructures (openings 22) so that, during the assembly one on top of the other, vertical coupling structures 45 are created that are only separated in superimposed regions of the light waveguides 40, 46 by way of the thickness of an intermediate polymer film (buffer film 42) having suitable optical properties.
In FIG. 7 the light waveguides 40 lie in the polymer substrate plate 32 (below). The associated fiber guide structures 14 (V-trenches) in the view are somewhat wider, so that the (consequently lower-lying) glass fiber axes become aligned with the optical axes of the associated light waveguides 40. The buffer film 42 comes to lie above the light waveguides 40 of the substrate plate 32. The light waveguides 46 (which actually lie on the underside of the polymer lid plate 34) then come into position in an assembled component 10, as shown by way of example. The narrower V-trenches in the substrate plate 32 form the adjusting structures 36 of the glass fibers to be held in the lid plate 34 in the fiber guide structures 14, and thus serve simultaneously to adjust lid plate 34 and substrate plate 32 relative to one another. The coupling distance (film thickness of the buffer film 42) and the effective coupling length L eff (a function of the detailed layout of a coupler) of such a passive directional coupler determine whether, for example, the light is completely overcoupled from the low-lying light waveguide 40 into the upper-lying light waveguide 46, or is divided in a determined ratio between the two light waveguides 40, 46.
The precise design of the component 10 is explained by way of the cross-sections of lines A--A, B--B, C--C shown in FIGS. 8 through 10.
FIG. 8 shows a section through the region of the fiber guide structures 14 and the adjusting structures 36 with inserted glass fibers 50.
Typical values for glass fibers 50 are R=125 μm for the fiber jacket diameter and r=9 μm for the field diameter of a glass fiber core 52. The glass fibers 50 are disposed laterally in a grid a (typically 250 μm), with the glass fibers 50 lying so as to fit exactly with respect to the optical axes of the light waveguides 40, 46 to be respectively contacted by them and which are in the substrate plate 32 or lid plate 34. With an assumed depth s of the light waveguides 40, 46, this presupposes a vertical offset by d+2(s/2)=d+s (d is the distance between substrate plate 32 and lid plate 34 determined by the thickness of the buffer film 42). The depths of the polymer guide structures t 1 and t 2 (fiber guide structure 14 or adjusting structure 36) result here from the depth of the respective V-groove etched into silicon plus the thickness s of the polymer cover layer (photoresist) on the master structure, into which the openings 22 were structured (corresponds to the depth of the light waveguides 40, 46). After the master structure was galvanically shaped and injection-molded, there is, of course, a difference between original Si surface 18 and polymer cover layer 20 in the polymer structures of FIG. 7 is no longer possible--hence, a horizontal dashed line was respectively drawn for clarification of this.
The widths of the V-grooves w 1 to be etched into the silicon master structures for the fiber guide structures 14 and w 2 for the respective V-shaped adjusting structures 36 on the opposite polymer plate are easy to calculate in this example: ##EQU2## In the example given, w 1 =148.8 μm (for δ 1 =3 μm) and w 2 =126.2 μm (for δ 2 =d+3/2 s=19 μm).
FIGS. 9 and 10 show cross-sections through the directional coupling component 10 of FIG. 7, with FIG. 9 showing the section (B--B) directly behind the fiber-coupling point, and clarifying the end-to-end coupling of the glass fibers with the light waveguides alternatingly lying in the substrate or lid plate, which coupling is respectively aligned with its optical axes.
FIG. 10 shows the section (C--C) through the center of the coupling region 45, in which the light waveguides 40, 46 come to lie exactly one above the other, and the coupling distance is determined only by way of the thickness d of the buffer film 42. A crucial point here is the exact adjustment of the light waveguides 40, 46 relative to one another, which is effected by means of the V-shaped guides (fiber guide structure 14 and adjusting structure 36) in lid plate 34 and substrate plate 32, and the glass fibers 50 inserted therein, because the V-shaped structures can respectively assume two defined overlay points on the round glass fibers 50 (free from play). By means of the photolithographic production, the guides can be positioned sufficiently precisely laterally with submicrometer precision. During assembly of the components 10, the glass fibers 50 are inserted into their fiber guide structure 14, and then cross-linkable prepolymers (core polymer) are poured into the light-conductive trenches (openings 22) of the substrate plate 32, which thus create the light waveguides 40, the buffer film 42 is placed on top, and the lid plate 34, likewise filled with prepolymer, is pressed on from above. Overhanging prepolymer is pressed away with this assembly technique and, after its cross-linking, assures a tabular connection. As a function of the viscosity of the prepolymer, a thin, tabular residual layer thickness of the same must possibly be included in determining the film thickness of the buffer film.
A simple estimate shows that the coupling distance k (calculated between light waveguide centers) varies with Δk 2 =(d+s) 2 +Δy 2 .
With the data from the above example, changes in the coupling distance Δk=0.5 μm result from a lateral mismatch of the light waveguides of Δy=4 μm (assuming radially symmetrical optical fields).
For simplified assembly, the polymer film 42 need not necessarily be guided up to the light waveguide ends of the light waveguides 40, 46 to fit exactly. Because of the very slight index differences of the waveguide core and substrate/film, the exit aperture angles at the light waveguide ends are very small (similar to those of the monomode fibers). Because the prepolymer, like an index liquid, guides the fields up to the end surface of the glass fibers, the actual light waveguide 40, 46 can already end in distances of approximately 20-50 μm in front of the glass fiber end, with tolerably small coupling losses. Tolerances of the film dimensions of this magnitude are therefore allowed in the light waveguide direction.
FIG. 11 shows a detailed coupling region 45 in section.
The cross-section dimensions of the light waveguide trench structures (openings 22) are to be dimensioned so as to be as independent as possible of the light wavelength to be guided, on the one hand, and, on the other hand, that the radially symmetrical field distribution of the glass fibers 50 is approached as closely as possible in order to achieve high degrees of coupling efficiency. For this purpose the refraction index of the light-guiding polymer (waveguide core) in the openings 22 must be slightly higher than the refraction indices of substrate plate 32, lid plate 34 and buffer film 42. Typical cross-section dimensions for monomode components at λ=1300 nm are 6 μm×6 μm with an index difference n core -n substrate 0.003. Corresponding to FIG. 11, the flanks of the light waveguides 40, 46 can advantageously be inclined by an angle of 70°≦γ90° in order to permit a simpler removal from the mold in injection molding (trapezoidal cross-section). The optimum thickness for an optical buffer film 42 is extremely dependent on its refractive index. For an assumed refraction index similar to the one of the substrate in the above example, the thickness could then be, for example, 10 μm (in individual cases, the optimum layout of the directional coupler structures must be adapted to the field distributions and coupling distances).
FIG. 12 shows a projectional top view of a 1×8 power divider as an example of a further polymer component 10. The component possesses inputs 1 through 8 and outputs 1 through 8, which are respectively connected to one another by means of light waveguides 40, 46.
As in FIG. 7, a top view of the substrate plate 32 with its light waveguides 40 and fiber guide structures 14 is represented. Shown opposite are the buffer film 42 and the imaginary position of the light waveguides 46 lying in the lid plate 34. Furthermore, for a simplified representation, the individual S-shaped light waveguide bendings at the inputs and outputs of each coupling region 45 are only schematically represented, respectively by a diagonal connection. It is shown how, for example, alternating light waveguides 40, 46 from the upper and the lower plane (substrate plate 32, lid plate 34) can be coupled with one another in order to achieve an optical signal division of an input (e.g. input No. 5) onto the outputs 1 through 8. In the example shown, the signal power (disregarding losses) would be 1/16 of the input power at the outputs 3, 4, 5, 6.
FIG. 13 illustrates a further embodiment which shows an optically-controlled optical switch. By way of example, the switching function is described here by way of an optical bypass switch; analogous expansions of the switching principle up to switching matrices for switching functions are possible.
For principle production and construction, refer to the explanations already given for the other examples.
In the normal state, the incident signal light is guided from input 1 to the photodiode (PD) at output 1, and the light of a local transmitting laser (LD) is conducted by way of the input 3 to the output 3 (input 4 is not engaged). A directional coupler 45 is passed through respectively on the two light paths in the "bar" state, i.e. the light is not overcoupled from the lower light waveguide 40 into the upper light waveguide 46. This is achieved by means of a deliberate detuning (Δβ) of the expansion constants (β) in the upper light waveguide 46 with an optically-induced change in the refraction index in the upper light waveguide 46: for this purpose this can include, for example, a non-linear-optical X.sup.(3) polymer which lowers its refraction index slightly by means of an additional irradiated control signal. If the control light signal is deactivated, the reduction in the index disappears, and the directional couplers 45 are respectively switched into the "cross" state, i.e. the input signal light goes to output 3 and the light of the transmitting laser goes into the non-engaged output 2 (sink). This switching function would be practical during, for example, interference (voltage breakdown) of a subscriber station, during which this station would then be bridged until the control light beam is reactivated. The control light can be generated locally in the receiver station (for example by means of an SLD coupled directly to the optical polymer chip) or fed by way of a fiber over the local network (optical "remote" switch).
Whereas the X.sup.(3) nonlinearities are normally very small, and would require unacceptably high control light outputs, so-called cis/trans nonlinearities (molecular structure changes) already assure sufficiently dramatic changes in refractive index of Δn˜0.0008 at light outputs of a few˜m Watts, but usually at the expense of the switching speeds. For example, "methyl red derivatives" can be dissolved in prepolymers (e.g. epoxy resins) and thus poured into the light-conductive trenches openings 22) as core material and cross-linked. Here switching takes place with "red" light in a wavelength range of 600-700 nm. For the control light source, an inexpensive, broadband red laser diode, or even a simple superluminescence diode (SLD) can be used (unlike for the expensive transmitting laser at 1300 nm or 1550 nm), provided that sufficient light output (a few mW) can be coupled into the light waveguide 46. Because the light waveguides 46 are dimensioned in a monomode manner, for example, for 1550 nm, the same light waveguides 46 are multimode for 600-700 nm wavelength, which significantly simplifies light absorption from the control light source. At the same time, the evanescent fields of the shorter wavelength decay considerably faster over the thickness of the buffer film 42, so that practically no control light is overcoupled into the low-lying communication channels (light waveguides 400, whereas the long-wave light can pass through the coupler, depending on the switching state, in the cross or bar state.
The listed switching functions are also to be used analogously, depending on the layout of the directional couplers 45, and the desired system application, such that switching the directional couplers 45 from cross to bar (or vice versa) is effected by means of activating the control light source--the associated switching speeds of known X.sup.(3) materials are higher during the activation process. | A method of producing passive and/or active optical polymer components (10) having vertical coupling structures (45), wherein at least one structure (22) for receiving a light waveguide (40; 46), and at least two fiber guide structures (14) and at least two adjusting structures (36) are produced on a substrate plate (32) and on a lid plate (34) such that both the plate and the lid plate possess fiber guide structures (14) with which the adjusting structures (36) located opposite in the lid plate or substrate, plate respectively are associated after assembly, and wherein the light waveguide structures (22) of the substrate plate (32) and the lid plate (34) which connect the fiber guide structures (14) extend parallel to each other in at least one region (45) such that the optical fields in the respective light waveguides (40) can be coupled with one another. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a vector for large scale production of human or animal proteins using plant cells, a method of large scale production of human or animal proteins using plant cells, to a method of large scale production of human protein C using plant cells and to plant bioreactors for the expression of human or animal proteins using plant cells.
2. Description of Prior Art
Several foreign proteins have been expressed in plants for diverse purposes: pest resistance, viral and fungal resistance, environmental stress tolerance, herbicide resistance or tolerance, food quality and processing, experimental studies, and for the expression of specialty chemicals.
Among the proteins which were expressed in plant cells, there is the following:
A human neuropeptide which was linked to a fragment of the plant 2S albumin gene. The peptide accumulated in the seeds of Arabidopsis and of oilseed rape at levels up to 200 nmol and 50 nmol respectively per gram of seeds;
Chicken ovalbumin in alfalfa with levels of ovalbumin up to 0.01% of total soluble proteins;
The prepro-human serum albumin gene was transfected in potatoes. The prosequence was not cleaved before secretion from the plant cells but the human signal sequence was recognized by the plant endoplasmic reticulum; and
Antibodies were produced in tobacco plants.
Using plant transgenics for the mass production of foreign proteins has several advantages, such as the low cost of growing the plants, the possibility of growing the transgenic plants on a very large scale, the transformation procedures which are well established, and the possibility of using specific plant parts as a sink for engineered proteins. However, in the case of human or animal proteins requiring post-translational modifications, the lack of knowledge concerning the post-translational modifications in plants represents a potential problem.
Agrobacterium-mediated gene transfer is the most widely used technique for plant transformation. Agrobacterium tumefaciens is a saprophytic soil bacterium which is also a pathogen of many dicotyledonous plants causing the formation of crown galls. Pathogenic Agrobacterium has a megaplasmid of approximately 200 kilo base pairs called the Ti plasmid or tumour-inducing plasmid. The T-DNA (or transferred DNA) within the megaplasmid is delimited by two 25 base-pair (bp) sequences called the right and left borders. Virulence genes are located outside the T-DNA. These contain the information for the excision of the T-DNA at the T-DNA borders, and its transfer to the plant cells. Agrobacterium-mediated gene transfer takes advantage of this system to transfer foreign DNA.
The binary vector strategy exploited here uses E. coli-Agrobacterium shuttle vector. This vector contains the T-DNA borders flanking the foreign DNA. This vector is introduced into Agrobacterium which moves the T-DNA in trans to the plant cells. The binary vector strategy uses disarmed Ti plasmids.
There is a demand for many human or animal proteins which have therapeutical applications. These proteins are sometimes difficult to produce in large quantities.
Since the use of human protein C (HPC) concentrate as a therapy appears promising (Dreyfus, M. et al., 1991, N. Engl. J. Med., 325:1565-1568), several isolation and production systems have been studied.
The purification of HPC from human plasma constitutes a challenge since HPC is present in the plasma at concentrations of approximately 4 μg/ml and contaminants from similar vitamin K-dependent plasma proteins may be difficult to remove. In addition, there is always the possibility of infectious agent contamination. Nevertheless, Velander et al. (1991, In protein C and related anticoagulants, Bruley, D. F. and W. N. Drohan (eds), Portfolio, The Woodlands, Texas, p.11-27) designed a protocol to purify HPC from plasma. The starting material is either cryopoor plasma or reconstituted Cohn IV-1 paste which is filtered and adsorbed on an anion-exchange chromatography column. The eluate containing HPC is treated with solvent and detergent to inactivate viruses and it is adsorbed on a protein C immunoaffinity column. The eluate is again adsorbed on anion-exchange chromatography and HPC finally undergoes diafiltration before formulation. The amount of purified HPC is small and may not be useful for industrial applications.
Synthesis of biologically active recombinant protein C by bacteria or yeast is precluded because those organisms are unable to perform some of the critical post-translational modifications. Production of vitamin K-dependent plasma proteins by most mammalian cells resulted in partially processed proteins and low transcription levels (Anson et al., 1985, Nature, 315:683-685; Busby et al., 1985, Nature, 316:271-273; Grinnell et al., 1987, Bio/Technology, 5:1189-1192; de la Salle et al., 1985, Nature, 316:268-270). However, improved cell lines have been described recently, which secreted correctly processed HPC (McClure et al., 1992, J. Biol. Chem., 267:19710-19717). The best results have been achieved using transgenic animals. Velander et al. (1991, Ann. N.Y. Acad. Sci., 665:391-403) demonstrated that engineered mice could produce biologically active HPC in their milk at concentrations of up to 3 μg/ml. Velander et al. (1992, Proc. Natl. Acad. Sci. USA, 89:12003-12007), also reported that transgenic swine were capable of high-level expression of HPC. A concentration of 1 g per liter of milk was detected from the best animal. The use of animals for the production of human protein C is not desirable due to the difficulties associated with the purification of the human transgenic protein away from related animal proteins.
It would be highly desirable to be provided with a vector for the large scale production of human or animal proteins using plant cells.
It would be highly desirable to be provided with a bioreactor for the large scale production of human or animal proteins using plant cells.
It would be highly desirable to be provided with a method of large scale production of human or animal proteins using plant cells.
It would be highly desirable to be provided with a method of large scale production of human protein C using plant cells.
SUMMARY OF THE INVENTION
One aim of the present invention is to provide a vector for the large scale production of human or animal proteins using plant cells.
Another aim of the present invention is to provide a method of large scale production of human or animal proteins using plant cells.
Another aim of the present invention is to provide a bioreactor for the large scale production of human or animal proteins using plant cells.
Another aim of the present invention is to provide a method of large scale production of human protein C using plant cells.
In accordance with one embodiment of the present invention, there is provided an expression vector for the large scale production of a human or animal protein, which comprises a DNA construct consisting of operatively linked DNA coding for a plant promoter, a transcription terminator and said human or animal protein to be expressed. More specifically, the expression vector is referred to as pCP2.
In accordance with another embodiment of the present invention, there is provided an expression vector for the large scale production of a human or animal protein, which comprises a DNA construct consisting of operatively linked DNA coding for a plant promoter, a mRNA stabilizer, a transcription terminator, and said human or animal protein to be expressed. More specifically, the expression vector is referred to as pLG3.
In accordance with the present invention there is provided a plant bioreactor for the large scale production of a human or animal protein, which comprises dicotyledonous plants transformed with a DNA construct consisting of operatively linked DNA coding for a plant promoter, a transcription terminator and said human or animal protein to be expressed flanked by T-DNA borders and a suitable selectable marker for plant transformation.
In accordance with the present invention there is provided a plant bioreactor for the large scale production of a human or animal protein, which comprises dicotyledonous plants transformed with a DNA construct consisting of operatively linked DNA coding for a plant promoter, a mRNA stabilizer, a transcription terminator and said human or animal protein to be expressed flanked by T-DNA borders and a suitable selectable marker for plant transformation.
In accordance with the present invention there is provided a method of large scale production of human or animal proteins, which comprises the steps of:
a) inserting a suitable recombinant expression vector in plant cells using Agrobacterium transformation, said expression vector comprising operatively linked DNA coding for a plant promoter, a transcription terminator and said human or animal protein to be expressed flanked by T-DNA borders and a suitable selectable marker for plant transformation; and
b) recovering said expressed human or animal protein of step a) from said culture medium.
In accordance with the present invention there is provided a method of large scale production of human or animal proteins, which comprises the steps of:
a) inserting a suitable recombinant expression vector in plant cells using Agrobacterium transformation, said expression vector comprising operatively linked DNA coding for a plant promoter, a mRNA stabilizer, a transcription terminator and said human or animal protein to be expressed flanked by T-DNA borders and a suitable selectable marker for plant transformation; and
b) recovering said expressed human or animal protein of step a) from said culture medium.
In accordance with the present invention there is provided a method of large scale production of human protein C, which comprises the steps of:
a) inserting a suitable recombinant expression vector in plant cells using Agrobacterium transformation, said expression vector comprising operatively linked DNA coding for a plant promoter, a transcription terminator and said human protein C to be expressed flanked by T-DNA borders and a suitable selectable marker for plant transformation; and
b) recovering said expressed human protein C of step a) from said culture medium.
In accordance with the present invention there is provided a method of large scale production of human protein C, which comprises the steps of:
a) inserting a suitable recombinant expression vector in plant cells using Agrobacterium transformation, said expression vector comprising operatively linked DNA coding for a plant promoter, a mRNA stabilizer, a transcription terminator, and said human protein C to be expressed flanked by T-DNA borders and a suitable selectable marker for plant transformation; and
b) recovering said expressed human protein C of step a) from said culture medium.
For the purpose of the present invention the following terms are defined below.
The term "human or animal proteins" is intended to mean any human or animal protein which include without limitation, human protein C (HPC), factor VIII, growth hormone, erythropoietin, interleukin 1 to 7, colony stimulating factors, relaxins, polypeptide hormones, cytokines, growth factors and coagulation factors.
The term "plants" is intended to mean any dicotyledonous plants, which include without limitation tobacco, tomato, potato, crucifers.
The term "operatively linked" is intended to mean that the elements are physically joined on the same piece of DNA to produce a unit with a specific purpose.
The term "T-DNA borders" is intended to mean the 25 base pair Agrobacterium-derived sequences that delimit the fragment of DNA that will be transferred to the plant cell with the help of Agrobacterium proteins.
The expression "a suitable selectable marker for plant transformation" is intended to mean any gene coding for a function that will allow the identification of transformed plant cells, such as kanamycin resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the construction of plasmid pCP2;
FIG. 2 illustrates the construction of plasmid pLG3;
FIG. 3 is a graph of first screen for HPC production of samples 1 to 27;
FIG. 4 is a graph of first screen for HPC production of samples 28 to 54;
FIG. 5 is a graph of first screen for HPC production of samples 55 to 81;
FIG. 6 is a graph of first screen for HPC production of samples 82 to 104;
FIG. 7 illustrates a Western immunoblot of reduced samples from ion-exchange #7 using a rabbit anti-HPC serum.
DETAILED DESCRIPTION OF THE INVENTION
The present invention was designed to express human or animal proteins, namely human protein C (HPC), in plants. This novel approach has several advantages over mammalian transgenics: the low cost of growing the plants, the ability to produce the protein on a very large scale, and the elimination of contamination by related animal proteins during purification of the expressed human or animal protein.
The preferred biorectors in accordance with the present invention include most dicotyledonous plants, particularly the solonacae, which include (but are not limited to) tobacco, potato and tomato, and the crucifers as transformed with the vector of the present invention.
The preferred plants in accordance with the present invention include without limitation tobacco, tomato, potato and crucifers.
Many other human or animal proteins, beside human protein C, may be prepared in accordance with the present invention. The preferred human or animal proteins to be expressed in accordance with the present invention include, but are not limited to, anticoagulation proteins, such as human protein C, factor VIII, or tissue plasminogen activator, and other proteins of pharmaceutical or veterinary interest.
Human protein C (HPC) is a vitamin K-dependent plasma glycoprotein which is a key element of the anticoagulation cascade. It is synthesized by the liver cells as a single peptide but is modified into a heterodimer linked by a disulfide bond before its secretion to the bloodstream. Some individuals are partially or completely HPC deficient, a situation that increases the likelihood of an early thrombotic event which may be lethal. Purified HPC injection has been used as an experimental treatment for homozygous deficient patients who are not producing HPC, but is also a promising drug for several other complications such as septic shock, thrombolytic therapy, and hip replacement. The annual demand in the U.S.A. for HPC represents about 96 kg. At the moment, HPC is purified from human plasma. Several researchers are experimenting with the synthesis of HPC in the milk of transgenic animals. In accordance with the present invention, the production of HPC is intended to serve as an example of the human or animal proteins which can be produced at a very large scale using plants as bioreactors.
The method of the present invention involved engineering tobacco plants using Agrobacterium-mediated gene transfer associated with the binary vector strategy of Hoekema et al. (1983, Nature, 303:179-180). Agrobacterium-mediated gene transfer takes advantage of the gene transfer system provided by the bacterium. The binary vector strategy consists of using A. tumefaciens with a Ti plasmid, inserting an accessory plasmid called the binary vector into the bacterium, and allowing T-DNA transfer. The accessory plasmid contains T-DNA border sequences with the desired genes and regulating elements located between them.
Engineering tobacco plants to produce human or animal proteins, or for example HPC, was achieved via the use of either of the two plasmids with different elements for the regulation of the expression of the introduced cDNA. The first plasmid included the constitutive cauliflower mosaic virus (CaMV) 35S promoter to drive gene expression, the second included a dimer of the 35S constitutive promoter with an alfalfa mosaic virus (AMV) leader sequence to enhance stability of the transcript. Duplicating the promoter has previously been found to enhance transcription, while the leader sequence enhanced translation.
Expression of the T-DNA was verified by analyzing HPC and neomycin phosphotransferase II (NPTII) synthesis by enzyme linked immunosorbent assay (ELISA) and inheritance of the T-DNA insert was observed by germinating R 1 seeds on antibiotic-containing medium or by ELISA to HPC on R 1 seedlings.
Purification protocols were created and preliminary experiments are described. Biological activity of various protein fractions was measured.
Tobacco plants engineered with the human protein C (HPC) cDNA and plant promoters expressed HPC. This was demonstrated by ELISA and Western assays using a combination of antibodies to human protein C. No similar protein was found in non-transformed plants. The protein had the expected molecular weight of the uncleaved form of HPC.
Changes in coagulation times were observed in several experiments when tobacco extracts were tested for clotting activity.
Plant transformation and selection
Several cell types or tissues can be used but cells must be totipotent, that is, able to regenerate mature plants. Plant cells or tissues are co-cultivated with Agrobacterium for a few days to allow T-DNA transfer. After co-cultivation, plant cells and tissues are grown on media with antibiotic which suppresses bacterial growth. Engineered plant cells survive because an antibiotic resistance marker gene is transferred with the foreign DNA. This system allows elimination of non-transformed plant cells. Plantlets are regenerated for analysis using plant tissue culture media with various plant growth regulator levels.
HPC structure and post-translational modifications
HPC is a complex vitamin K-dependent plasma glycoprotein. The HPC mRNA codes for a single peptide including a signal peptide and a propeptide sequence. After cleavage of the single chain by removal of the KR dipeptide (Lys-Arg), HPC is secreted to the bloodstream as a two-chain glycoprotein with a molecular weight of 62,000 Da. The light chain (21,000 Da) and the heavy chain (41,000 Da) remain attached by a disulfide bond. However, before secretion, HPC must undergo several post-translational modifications.
Determination of HPC's biological activity
A cDNA clone coding for HPC was inserted downstream of the CaMV 35S promoter and of a dimer of the CaMV 35S promoter. Tobacco plants were transformed using Agrobacterium and a binary vector strategy. Kanamycin resistant plants were regenerated. T-DNA integration was tested to insure that plants were stably transformed. R 1 seedlings were also analyzed. A second round of transformation was performed in order to increase the level of HPC expression. Partial protein purification (using ion-exchange chromatography), dialysis and ultrafiltration were followed by various analyses (SDS-PAGE, Western immunoblot) in order to assess protein purity and activity. Clotting assays were performed in order to determine whether the plant-produced HPC was biologically active.
1. Recombinant DNA manipulations
The binary vector pBI121 and a culture of Agrobacterium tumefaciens strain LBA4404 were purchased from Clontech. The plasmid pBI524 and pLPC were provided by Dr. Bill Crosby from Agriculture Canada and by Dr. Jeff Turner (Department of Animal Science, McGill University). Restriction and modifying enzymes were purchased from New England Biolabs and the DNA marker (1KB DNA ladder) from BRL. Standard recombinant DNA manipulations were used during the construction of the binary vectors and all plasmid manipulations were performed using E. coli strain DH5α if not specified. Finally, the concentration of agarose for gel electrophoresis was 0.8% unless mentioned, and gels were run in 0.7X TBE buffer (89 mM Tris, 89 mM boric acid, 2 mM EDTA, pH 8.3). Specific DNA fragments to be recovered after enzymatic digestion were electrophoresed in TAE buffer (40 mM Tris-acetate, 2 mM Na 2 EDTA, pH 8.5) and the Geneclean™ II kit (BiO 101) was used to purify and extract the DNA from the agarose gel.
1.1 Non-radioactive hybridization
Plasmid DNA was digested with XbaI and EcoRI, electrophoresed in 1% agarose gels (TBE), and transferred onto Hybond™ N + nylon membrane (Amersham) by alkaline transfer with 0.4M NaOH according to the membrane manufacturer's instructions. The BclI fragment containing the HPC cDNA from pLPC was digested, electrophoresed in an agarose gel in TAE, and isolated by Geneclean™ II. The BclI fragment was used as the probe. Probe labelling, hybridization, and detection was carried out using non-radioactive DIG™ DNA Labelling and Detection Kit (Boehringer Mannheim) according to the manufacturer's instructions.
1.2 Genomic DNA isolation
Plant genomic DNA from transgenic tobacco was isolated using the CTAB (hexadecyltrimethylammonium bromide) method. Five grams of leaf material (previously frozen at -70° C.) were homogenized in 15 ml of prewarmed CTAB buffer (100 mM Tris-Cl pH 8.0, 1.4M NaCl, 20 mM EDTA, 0.2% β-mercaptoethanol, 2% CTAB) in a Waring™ blender and incubated for 30 minutes at 60° C. The solution was mixed every 5 minutes. An equal volume of chloroform-isoamyl alcohol (24:1) was added to the tube, mixed well and centrifuged 3000 g for 15 minutes at 4° C. The aqueous phase was collected and chloroform-extracted once more. The aqueous phase was transferred to a new tube and precooled (-20° C.) isopropanol was added 2/3 volume of the aqueous solution. The mixture was inverted a few times and incubated at -20° C. for at least 60 minutes. DNA was precipitated by centrifugation 10,000 g for 10 minutes at 4° C. Supernatant was removed and the DNA pellet washed with 10 mM ammonium acetate in 76% ethanol. DNA was vacuum-dried and resuspended in TE buffer (10 mM Tris-Cl and 1 mM EDTA, pH 8.0).
1.3 Southern hybridization
Genomic DNA (20 μg) was digested with Sau3AI and DNA fragments were separated by agarose gel electrophoresis (1% agarose) in TBE buffer. DNA was transferred to Hybond™ N + nylon membrane (Amersham) using alkaline transfer following the manufacturer's instructions. The DNA probe was the cDNA of HPC (BclI fragment of pLPC) labelled with α 32 P-dCTP (ICN) using the T7 Quickprime™ kit of Pharmacia. The nylon membrane was incubated in 30 ml of prehybridization buffer (250 mM NaHPO 4 pH 7.2, 2.5 mM EDTA, 7% sodium dodecyl sulfate (SDS), 1% blocking reagent (Boehringer Mannheim), 50% deionized formamide) for 24 hours at 42° C. The prehybridization buffer was replaced by 15 ml of hybridization buffer (prehybridization buffer with 10% dextran sulfate) and incubated with the probe and the membrane overnight at 42° C. The membrane was washed three times 15 minutes at 42° C. with 2X SSC (20X SSC was 3M NaCl and 0.3M Na 3 citrate, pH 7.0) and 0.1% SDS, followed by 0.5X SSC and 0.1% SDS, and then 0.1X SSC and 0.1% SDS. The final wash was with 0.1X SSC and 0.1% SDS for 30 minutes at 52° C. The X-ray film (Kodak™ X-OMAT AR) was exposed for approximately 7 days.
1.4 Transfer of plasmids into Agrobacterium
Three plasmids (pBI121, pCP2, and pLG3) were purified from E. coli using an alkaline lysis DNA minipreparation. Vector DNA was transferred to A. tumefaciens strain LBA4404 using a freeze and thaw method.
2. Plant transformation
2.1 Plant material propagation
Seeds of Nicotiana tabacum cv. Xanthi were sterilized for 15 minutes in a 10% bleach solution with a drop of detergent (Tween™-20). Seeds were washed at least five times with sterile distilled water and allowed to germinate and grow on artificial medium composed of basal MS salts, B5 vitamins, 3% sucrose, and 0.6% agar (Anachemia) at pH 5.7-5.8. Seed were grown under a 16 hour photoperiod with a light intensity of 50 μE and a temperature of 24° C.
2.2 Preparation of Agrobacterium inoculum
A. tumefaciens was grown in Luria Broth (LB) (1% tryprone, 0.5% yeast extract, 85 mM NaCl, pH 7.0) medium supplemented with 50 μg/ml kanamycin and 25 μg/ml of streptomycin for 18 hours or until the optical density at 595 nm reached 0.5 to 1.0. Cells were spun down at 3,000 g for 5 minutes and the pellet was resuspended to its initial volume with MS-104 medium (MS basal salts, B5 vitamins, 3% sucrose, 1.0 μg/ml benzylaminopurine (BAP), 0.1 μg/ml naphtaleneacetic acid (NAA), pH 5.7-5.8, and 0.8% agar) without agar.
2.3 Leaf disc transformation
Leaf squares of about 64 mm 2 were dissected using a sharp scalpel, immersed in the inoculum for 15-30 minutes and plated onto MS-104 medium for 2 days under a 16 hour photoperiod, under low light intensity (20 μE) at 24° C. for cocultivation. Leaf discs were washed alternately three times with sterile distilled water for 1 minute and sterile distilled water supplemented with 500 μg/ml of carbenicillin for 5 minutes. Leaf discs were transferred to MS-104 medium with 500 μg/ml of carbenicillin for another 2 days under the same environmental conditions.
2.4 Selection and regeneration
Leaf discs were washed as above, plated on MS-104 medium with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin, and grown using the above environmental conditions until calluses appeared. The light intensity was increased to 50 μE and the explants were allowed to grow until development of well-formed shoots. Shoots were excised and transferred onto MS-rooting medium (MS-104 but with 0.6% agar and no plant growth regulators) with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin. Surviving plantlets with well-formed roots were removed from the artificial medium, dipped alternately in a 0.06% 50WP Benlate™ solution and in a rooting powder (Stim-root #1) containing indole-3 butyric acid, and transplanted into pasteurized Promix™ soil mixture. Plantlets were covered with a transparent cover which was gradually lifted during the following 7 days.
3. T-DNA expression analysis
3.1 NPTII immunoassay
A double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) was used to analyze T-DNA expression. The DAS-ELISA for NPTII detection was based on the Nagel et al. (1992, Plant Mol. Biol. Rep., 10:263-272) procedure. Approximately 100 mg of leaf material was homogenized in 300 μl of PBS-TP (137 mM NaCl, 43 mM Na 2 HPO 4 , 27 mM KCl, 14 mM KH 2 PO 4 , 0.05% Tween™-20, 2% polyvinylpyrrolidone (PVP), pH 7.4). Debris was removed by centrifugation (10,000 g for 2 minutes) and the concentration of soluble proteins was determined for every sample using the Bradford method (Bradford, N. M. 1976, Anal. Bio. Chem., 72:248-254). Samples were diluted to 400 μg/ml in PBS-TP. Microtiter plates (Falcon) were coated with 200 μl of rabbit anti-NPTII (5 Prime→3 Prime Inc.) diluted 1:500 in carbonate buffer (35 mM NaHCO 3 , 15 mM Na 2 CO 3 , pH 9.6). The antibody was incubated for 2 hours at 37° C. Wells were washed five times with PBS-T (PBS-TP without PVP) by alternately filling the wells with a multichannel pipette and emptying the plates in the sink. Wells were blocked with a solution of PBS-T containing 2% BSA for 30 minutes at room temperature (RT). Wells were washed five more times. Leaf samples (200 μl) were added and incubated for 2 hours at RT. Wells were washed five times and 200 μl of biotinylated NPTII antibody (5 Prime→3 Prime Inc.), diluted 1:500 in PBS-TPO (PBS-TP with 0.2% BSA), was added and incubated at RT for 1 hour. Wells were washed five times and 200 μl of P-nitrophenyl phosphate (PNP) diluted to 1 mg/ml in substrate buffer (9.7% diethanolamine, pH 9.8) was incubated for approximately 40 minutes. Absorbance was measured by a microtiter plate reader (Bio-Rad™ 450) with a 405 nm filter.
3.2 HPC immunoassay
Plant samples were homogenized as for the NPTII ELISA. A polyclonal rabbit anti-HPC (Sigma) was diluted 1:2000 in carbonate buffer and used to coat the wells of microtiter plates (Falcon) for 2 hours at 37° C. Wells were washed five times with PBS-T and blocked with a solution of PBS-T and 2% BSA for 30 minutes at RT. Wells were washed five more times and 200 μl of leaf extract was added and incubated overnight at 4° C. Wells were washed five times and 200 μl of a polyclonal goat anti-HPC (Biopool), diluted 1:2000 in PBS-TPO, was added and incubated at RT for 2 hours. Wells were washed five times and 200 μl of a swine anti-goat IgG (Cedarlane), diluted 1:3000 in PBS-TPO, was added and incubated at RT for 1 hour. Wells were washed five more times and 200 μl of 1 mg/ml PNP dissolved in substrate buffer was added. Color development was allowed to proceed in the dark for at least 1 hour and color intensity was measured using a microtiter plate reader with a 405 nm filter. A standard curve was also made using purified HPC (American Diagnostica) diluted in PBS-T.
3.3 Germination of R 1 seeds on kanamycin-containing medium
Seeds produced by R 0 plants were collected and germinated on artificial medium (see described in section 2.1) containing 100 μg/ml of kanamycin to assay for antibiotic resistance among the R 1 generation and segregation of the transferred gene.
3.4 Double transformation
R 1 seeds from S-2B transformed tobacco plant were grown in vitro and transformed using the pCP2 vector inserted in Agrobacterium tumefaciens (as described in section 2. above).
A total of three S-2B controls (transformed once) and 104 potentially double transformant plants were analyzed for their HPC production. DAS-ELISA was used to determine HPC concentration (using PBS-T as a blank) while the Bradford method was used to measure the soluble protein concentration (the latter analysis was made with the Bio-Rad™ protein assay kit using ddH 2 O as a blank). ##EQU1## 4. Engineering tobacco for the expression of protein C
The tobacco genome was modified in order to synthesize HPC. This involved the construction of two plasmids which contained a T-DNA and the HPC cDNA, the transfer of HPC cDNA into tobacco and the analysis of T-DNA expression among regenerated plants.
4.1 Binary vectors
Two binary vectors for the expression of plant HPC were constructed in order to avoid using a single construct which could have errors acquired during DNA manipulations. Both pCP2 (FIG. 1) and pLG3 (FIG. 2) constructs contained the right and left T-DNA border sequences and the selectable marker gene NPTII, which provides resistance to kanamycin and allows quick selection of engineered plants.
Plasmid pCP2 is a derivative of pBI 121. Its T-DNA is delimited by two T-DNA border sequences (triangles, FIG. 1) which flank the selectable marker gene neomycin phosphotransferase II (NPTII) preceeded by the nopaline synthase promoter (P) and terminated with the nopaline synthase terminator (T). In addition, the cDNA of HPC (cDNA HPC) was cloned in between the CaMV 35S promoter (35S) and a nopaline synthase terminator (T). Approximate sizes of the elements between the border sequences are indicated and key restriction sites are indicated above the diagram.
Plasmid pLG3 is a derivative of pBI 121. Its T-DNA is delimited by two T-DNA border sequences (triangles, FIG. 2)) which flank the selectable marker gene neomycin phosphotransferase II (NPTII) preceeded by the nopaline synthase promoter (P) and terminated with the nopaline synthase terminator (T). In addition, the cDNA of HPC (cDNA HPC) was cloned downstream of a double CaMV 35S promoter (35S) and an AMV leader sequence and upstream of a nopaline synthase terminator (T). Approximate sizes of the elements between the border sequences are indicated and key restriction sites are indicated above the diagram.
The NPTII gene is regulated by the nopaline synthase promoter and the NOS-T.
pCP2 construct
A 1420 bp BclI fragment, which contained the cDNA of HPC, was cut out from pLPC and cloned into the BamHI site of vector pBI524. pBI524 is a derivative of pUC9 with, (5' to 3'), a dimer of the CaMV 35S promoter, an alfalfa mosaic virus (AMV) leader sequence, a polylinker (NcoI, XbaI, BamHI), and a NOS-T. The new construct was called pCP1. The cDNA sequence was preferred to the genomic sequence because it is easier to manipulate smaller DNA sequences, and it is not known if plant cells will correctly splice out human introns.
In order to verify the-orientation of the cloned HPC cDNA, a BglII restriction digestion was performed on plasmid DNA isolated from recovered E. coli colonies. BglII was expected to cleave at the 3' end of the double CaMV 35S promoter and 210 bp away from the 5' end of HPC cDNA thus generating two DNA fragments of approximately 300 bp and 4800 bp if the cDNA was well oriented, that is the ATG codon from the HPC cDNA was immediately downstream of the AMV leader sequence. Two bands of the correct size were observed.
An XbaI-EcoRI cassette was isolated from pCP1 and ligated in place of the XbaI-EcoRI cassette from pBI121. Therefore, the GUS gene with the NOS-T was replaced by the cDNA of HPC with its accompanying NOS-T forming the plasmid pCP2. The HPC cDNA is under the control of the constitutive CaMV 35S promoter from pBI121 which is known to highly express foreign proteins.
pLG3 construct
Vector pBI524 contained an undesirable ATG which is part of the NcoI restriction site. The ATG was deleted by cleaving pBI524 with NcoI, removing single stranded sticky ends with mung bean nuclease, and ligating the modified vector which was named pLG1. The removal of the NcoI restriction site was verified with a double digestion with NcoI and ScaI. Two bands were observed when pBI524 was digested with the two restriction enzymes while only one band appeared for pLG1 indicating that the NcoI site was missing.
The HPC cDNA BclI fragment was cloned into the BamHI site of pLG1 to create pLG2. Then, a HindIII-EcoRI cassette from pLG2 was cloned in place of the HindIII-EcoRI from pBI121. Therefore, the CaMV 35S promoter along with the GUS gene and a NOS-T were replaced by a dimer of the CaMV 35S promoter with an AMV leader sequence, the cDNA of HPC, and a NOS-T. Doubling the CaMV 35S promoter is known to markedly increase transcription, while the leader sequence enhances translation of the expressed protein.
Transfer of Plasmids pCP2 and pLG3 into A. tumefaciens
Plasmids pCP2 and pLG3 were transferred into A. tumefaciens LBA4404 using a freeze/thaw method. In order to verify whether the plasmids were successfully transferred, a non-radioactive Southern hybridization was attempted. The cDNA of HPC was observed to hybridize to plasmid DNA isolated from A. tumefaciens and E. coli transfected with pCP2 while there was no hybridization with the control plasmid pBI121.
4.2 Engineering tobacco and selection of transformants
Leaf discs were inoculated with four Agrobacterium inocula:
A) Seventy-five leaf discs were inoculated with LBA4404 without any binary vector. Half of the leaf discs were grown on kanamycin-containing medium in order to verify the efficacy of kanamycin selection while the other half were grown on medium without antibiotic in order to recover negative control plants (untransformed tobacco).
B) One hundred leaf discs were inoculated with LBA4404 with the binary vector pBI121 as a control to monitor the transformation procedure's efficiency.
C) Two hundred leaf discs were inoculated with LBA4404 with the binary vector pCP2 for the expression of HPC.
D) Two hundred leaf discs were inoculated with LBA4404 with the binary vector pLG3 for the expression of HPC.
Kanamycin repressed regeneration of leaf discs inoculated with Agrobacterium without binary vector when cultivated on kanamycin-containing medium. Thus, the antibiotic selection was efficient in removing untransformed plants. Thirty-six plants were kanamycin resistant and survived transplantation to the greenhouse following inoculation with the binary vector pBI121. This indicates that the T-DNA transfer took place. A total of 230 kanamycin-resistant plants were regenerated: 118 engineered with pCP2 and 112 engineered with pLG3.
4.3 Analysis of HPC and NPTII expression
Screening R 0 plants for HPC expression
A DAS-ELISA procedure was preferred to other ELISA methods because this type of assay is less susceptible to non-specific binding of antibodies. Two polyclonal antibodies for HPC were selected for the sandwich complex with the HPC antigen because polyclonal antibodies recognize several epitopes of HPC. The ELISA for HPC was used to screen all recovered plants engineered with the pCP2 and pLG3 binary vectors, and to find which R 0 plants were potentially highly expressing HPC. A dilution of 1:2,000 was used for coating the rabbit anti-HPC antibody and 1:1,000 for the goat anti-HPC antibody. The dilution of swine anti-goat IgG was 1:3,000 as recommended by the manufacturer. Finally, the concentration of soluble protein in sap extracts was adjusted to 1 mg/ml. Negative control plants had ELISA values, after the background was removed, (PBS-TP buffer in place of sap extract) ranging from -0.003 to 0.125 with an average of 0.061 (n=38). Results for engineered plants varied from 0.025 to 0.513. All plants with ELISA values above 0.375 were selected for the optimization of the ELISA conditions and for the accurate quantification of HPC expression.
Optimization of HPC DAS-ELISA
Prior to the final HPC quantification, different ELISA conditions were tested in order to optimize the assay. Dilutions of the rabbit anti-HPC antibody and of the swine anti-goat IGg were kept as before while a 1:2,000 dilution of the goat anti-HPC antibody was used since reducing the quantity of antibody was found to only slow down color development. Eight concentrations of sap extract were tested: 1,000, 500, 250, 125, 63, 32, 16, and 8 μg/ml and the quantity of HPC present was determined using purified HPC. Overall, the percentage of HPC increased with the dilution of the sap extract (Table 1). Sap was extracted from six plants which had ELISA readings greater than 0.375 during HPC screening. Numbers represent the percentage of plant-produced HPC among total soluble proteins. ELISA readings were blanked against sap of non-transformed plants and the percentage of HPC determined against a purified HPC standard curve. A protein concentration of 5 μg/ml was selected because a lower concentration of soluble protein would be too close to the lower limit of detection and a higher concentration would lead to underestimation of the amount of HPC present.
TABLE 1______________________________________Determination of optimal soluble protein concentrationin sap extractions for the immunodetection of HPCμg/ml leafextract S2F SS4B SS2E S4F SS1A SS1B______________________________________1000 0.0002 0.0000 0.0001 0.0000 0.0001 0.0001500 0.0004 0.0002 0.0002 0.0001 0.0001 0.0003250 0.0006 0.0003 0.0003 0.0001 0.0002 0.0004125 0.0013 0.0005 0.0006 0.0001 0.0005 0.000763 0.0022 0.0011 0.0014 0.0002 0.0012 0.001632 0.0034 0.0017 0.0028 0.0003 0.0023 0.003216 0.0057 0.0026 0.0050 0.0005 0.0048 0.00548 0.0079 0.0031 0.0072 0.0004 0.0068 0.0089______________________________________ Plant identification starting with "S" were engineered with the plasmid pCP2 while those starting with "SS" were engineered with pLG3.
Quantification of protein C expression
To confirm results from the first ELISA screening and to obtain a better estimate Of the amount of protein C in transformed plants, an ELISA assay using the above antibodies and sample dilutions was performed. Sap was extracted from each R 0 plant selected during the screening, and triplicates of the samples were incubated with the antibodies. Twelve non-transformed plants were used as negative controls to remove background due to plant proteins, and ELISA values were plotted against a purified HPC standard curve. Some R 0 plants expressed HPC at almost 0.03% of their proteins, others failed to produce significant amounts (Table 2). The five best plants, S5N, S5R, S2B, SS2D, and S5FF, were selected for a final quantification of HPC and verified for the expression of the NPTII marker gene. The percentage of HPC relative to plant proteins was determined as well as standard deviation.
TABLE 2______________________________________Quantification of HPC among R.sub.0 plants which werepotentially highly expressing protein CPLANT % HPC STD DEV PLANT % HPC STD DEV______________________________________S5N 0.028 0.001 S5F 0.009 0.001S5R 0.025 0.001 S1B 0.009 0.001S2B 0.025 0.001 SS7G 0.008 0.002SS2D 0.023 0.001 S1F 0.008 0.001S5FF 0.020 0.000 S5W 0.008 0.001SS7R 0.019 0.001 S5U 0.008 0.001SS1A 0.019 0.001 SS5G 0.007 0.003S6B 0.018 0.002 S1I 0.007 0.001S5B 0.018 0.001 SS1F 0.005 0.002S8C 0.017 0.003 S5CC 0.004 0.002SS1B 0.017 0.005 SS4B 0.004 0.000S7L 0.017 0.002 S4F 0.003 0.001SS5J 0.017 0.001 S5H 0.002 0.002SS3F 0.016 0.000 S7F 0.001 0.001S5L 0.015 0.000 S5X 0.000 0.000S2F 0.015 0.006 S7O -0.000 0.002S5G 0.014 0.001 SS5B -0.002 0.001SS8M 0.014 0.003 S7K -0.003 0.001SS6B 0.014 0.002 S6H -0.003 0.002SS5Q 0.013 0.000 S5K -0.005 0.001SS2E 0.012 0.000 S51 -0.005 0.000SS6P 0.011 0.002______________________________________ Plant identifications starting with "S" were engineered with the plasmid pCP2 while those starting with "SS" were engineered with pLG3. Readings represent the average of three replicates. "% HPC" is the percent among total soluble tobacco proteins.
Expression of the marker gene NPTII and HPC among the best five plants
The same HPC ELISA procedure as above was used to confirm HPC quantification of the best five HPC-producing tobacco plants. In addition, NPTII ELISA was used to verify the expression of the marker gene. After removing background (PBS-TP buffer) from ELISA readings, all five plants had positive NPTII readings while all four negative control plants had negative NPTII readings (Table 3). Moreover, HPC percentage among soluble proteins was slightly negative for control plants because they consistently had ELISA readings lower than the PBS-TP buffer used to blank readings. Some engineered plants produced 0.02 to 0.03% of HPC. S2B, S5N, S5R, S5FF were transformed with pCP2, SS2D was transformed with pLG3 and C1B, C2A, C3A, C3D were not transformed with a binary vector.
TABLE 3______________________________________Percentage of HPC and detection of NPTII fromselected R.sub.0 plantsNPTII NPTII HPCREADINGS.sup.a STD DEV. % HPC.sup.b STD DEV.______________________________________S2B 0.371 0.015 0.033 0.001S5N 0.048 0.014 0.024 0.001S5R 0.040 0.010 0.023 0.001SS2D 0.155 0.030 0.021 0.001S5FF 0.134 0.050 0.020 0.002C1B -0.079 0.017 -0.008 0.001C2A -0.101 0.018 -0.007 0.001C3A -0.152 0.007 -0.010 0.001C3D -0.084 0.002 -0.004 0.003______________________________________ .sup.a NPTII ELISA readings were blanked against PBSTP buffer reading. .sup.b % HPC is the percentage of HPC among tobacco soluble proteins. Numbers represent the mean of three replicates.
Expression of HPC in R 1 families
The ELISA assay for HPC was used to verify the synthesis of HPC among the progenies of two of the best five HPC-producing tobacco plants. Seeds of S2B, S5N, and C3A were collected and germinated in soil. When R 1 plants had approximately four leaves, an ELISA was used to quantify HPC levels (Table 4). Twenty seedlings were tested per mother plant and ratios of seedlings synthesizing HPC versus those not synthesizing HPC were statistically analyzed. Mother plants were S2B and S5N, which were transformed with pCP2. The ratio of S5N progenies expressing HPC to those not expressing HPC was in agreement with the segregation of one dominant gene (Table 4). All S2B progeny expressed HPC, suggesting that two or more T-DNAs were present in the plant genome of the S2B mother plant.
TABLE 4______________________________________Inheritance of HPC expression in the R.sub.1 generation% HPCDetected S2B.sup.a S5N.sup.b C3A______________________________________0.02 11 0 00.01 9 14 00.00 0 6 10______________________________________ Numbers represent the number of R.sub.1 plants from which 0.02, 0.01, or 0.00% of soluble HPC protein was detected by ELISA. .sup.a Chisquare analysis at p = 0.05 for the segregation of two or more TDNA .sup.b Chisquare analysis at p = 0.05 for the segregation of one TDNA (3:1).
Double transformation
The S2B tobacco plants used here for a second transformation had previously been screened for their ability to survive on kanamycin medium. It was therefore not possible to use kanamycin selection to identify plants that were transformed a second time, since the same plasmid was used for both transformations. Plants capable of producing larger amounts of HPC (as a result of a second transformation event) were identified by comparing the putative double transformants to three single transformed plants (F 1 generation of S-2B plant) for the level of HPC using a DAS-ELISA.
First screen
FIGS. 3 to 6 show the relative HPC content of various second transformants; of 104 plants, eight produced significantly higher amounts of HPC: A 9-4 (#37), B 4-5 (#80), B 5-1 (#81), B 5-2 (#82), B 8-4 (#94), B 9-2 (#97), B 9-4 (#99) and B 10-1 (#100). To avoid eliminating plants that were high producers but were not among the eight best identified above, the 17 best plants (DAS-ELISA units/Bradford units higher than 7) were transferred to the greenhouse for further analysis (indicated by arrows on FIGS. 3 to 6).
Second and third screens
Following two additional quantitative evaluations, three plants showed consistantly higher HPC content: plants B 2-2, B 5-1 and B 8-1. During the second and the third evaluations, their average HPC production were respectively 42% and 23% higher than the three controls.
The plasmid pCP2 contained the marker gene NPTII and the cDNA of HPC under the control of the CaMV 35S promoter. Plasmid pLG3 contained NPTII and the cDNA of HPC was controlled by a dimer of CaMV 35S promoter with an AMV leader sequence. Growing non-transformed tobacco plants on kanamycin-containing medium indicated that the antibiotic selection was efficient while engineering leaf discs with pBI121 showed that the T-DNA was transferred properly to plant cells. The best HPC-producing tobacco plants were shown to express NPTII and HPC at levels representing 0.02 to 0.03% of their soluble proteins. The expression of HPC in R 1 plants was transmitted with a 3:1 ratio for S5N progeny while all S2B progeny expressed HPC, suggesting that the mother plant had two or more T-DNA inserts in its genome.
Some plants, transformed a second time, produced more HPC than the original transformants, with the best "twice-transformed" plant producing 43% more than the original mother plant.
5. Partial purification of plant-produced protein C
A series of experiments were designed to partially purify HPC in order to eventually characterize the protein and assay for its activity. All manipulations were performed either on ice or in a cold room at 4° C.
Anion-exchange chromatography
HPC expressed in tobacco plants was partially purified using an affinity chromatography purification protocol. Approximately 10 g of tobacco leaves with positive HPC ELISA readings were homogenized in a Waring™ blender with 30 ml of extraction buffer (20 mM Tris-Cl pH 7.4, 150 mM NaCl, 4 mM EDTA pH 7.4, 5 mM benzamidine-HCl). Most debris was removed by filtration through Miracloth™ and by centrifugation at 15,000 g for 10 minutes. A 16×200 mm column (Pharmacia) was filled with 10 ml of Fast Flow Q™ Sepharose (FFQ) anion exchanger (Pharmacia). FFQ resin was washed with 30 ml of equilibration buffer (20 mM Tris-Cl pH 7.4, 150 mM NaCl, 2 mM EDTA pH 7.4, 2 mM benzamidine-HCl). The sample was applied at the surface of the resin followed by another 30 ml of equilibration buffer. HPC was eluted by injecting 30 ml of elution buffer (20 mM Tris-Cl pH 7.4, 150 mM NaCl, 10 mM CaCl 2 , 2 mM benzamidine-HCl). A high salt elution was then applied (20 mM Tris-Cl pH 7.4, 400 mM NaCl, 2 mM benzamidine-HCl) and the resin was cleaned with a solution of 2M sodium acetate.
Sephadex desalting
Salts were removed from sap extracts immediately after centrifugation, using PD-10™ columns (Pharmacia) according to the manufacturer's instructions.
Complete debris removal
After centrifugation of the sap extract at 15,000 g, the solution was centrifuged for 1 hour at 100,000 g.
6. Partial purification of plant-produced HPC using ion-exchange chromatography
Following tests to optimize the pH of buffers (as described above in section 5.), three preliminary tests were made on the automated liquid chromatography system (BioRad) in order to set larger scale working conditions.
During experiments, the relative amount of total protein was monitored using the system's UV monitor, whereas the relative amount of HPC was determined on eluted samples using DAS-ELISA. All experiments were conducted under the following conditions:
Samples: Approximately 5.0 g of HPC + tobacco leaves were homogenized with 15.0 ml of extraction buffer and removed from debris using Miracloth™ and 10 minutes of centrifugation at 15,000 g.
Buffers:
Extraction buffer: 20 mM Tris-Cl, 150 mM NaCl, 4 mM EDTA, 5 mM benzamidine-HCl, pH 8.
Equilibration buffer: 20 mM Tris-Cl, 150 mM NaCl, 2 mM EDTA, 2 mM benzamidine-HCl, pH 5 or 8.
Elution buffer: 20 mM Tris-Cl, 150 mM NaCl, 2 mM benzamidine-HCl, pH 8.
Ca 2+ elution buffer: 20 mM Tris-Cl, 150 mM NaCl, 10 mM CaCl 2 , 2 mM benzamidine-HCl, pH 8.
Ion-exchange conditions
Column: Sepharose™ Q (Sigma), 5 ml
Buffers:
Extraction and equilibration at pH 8
Elution at pH 8
10 mM Ca 2+ elution at pH 8
10 mM Ca 2+ salt elution with 200 and
400 mM NaCl at pH 8
7. Analysis of plant-produced HPC
7.1 SDS-PAGE and Western immunoblot
Human Protein C is a 62,000 Da protein made of two subunits (41,000 and 21,000 Da) linked by a disulfide bridge. The addition of mercaptoethanol to the sample before loading onto the gel has the effect of destroying that disulfide bridge. Gel electrophoresis and Western blots were used to characterize the protein produced in tobacco plants.
Western immunoblot
Immunodetection was conducted by blocking 30 minutes with PBS and 5% powdered milk. Rabbit anti-HPC antibody (1:7,000) was added to the blocking solution. After an overnight incubation, the nitrocellulose was washed three times for 10 minutes each with PBS+0.5% Triton™ followed by a 10 minutes wash in TBS. The nitrocellulose was then transferred to TBS+5% powdered milk supplemented with a 1:14,000 dilution of goat anti-rabbit IgG conjugate (Bio-Rad) for 60 minutes. The nitrocellulose was washed four times in TBS for 15 minuntes each. Colorimetric detection of HPC was carried out using alkaline phosphatase activity.
Using these parameters, the samples used were:
S 25 ng of standard HPC (Sigma);
T+ HPC + tobacco plant (S-2B);
T- HPC - tobacco plant; and
T++ HPC + tobacco plant (second transformant).
This immunoblot confirmed the presence of HPC in transformed tobacco plants (FIG. 7). Both transformed plants displayed a major protein reacting with anti-HPC serum (lanes T+ and T++:61,300 MW) whereas no band was detected in the control (non-transformed) tobacco plant (lane T-). Lane S contained 25 ng of Sigma HPC. Two major proteins were detected corresponding to the heavy and light chains (40,100 and 23,700 Da, respectively).
From these results, it was concluded that: 1- HPC was produced in transformed plants; 2- HPC was not completely processed and possibly not cleaved into the heavy and light chain.
7.2 HPC location in tobacco plant
HPC concentration was measured in different tissues of a twice-transformed tobacco plant: 1- roots; 2- stem; 3- primary vein of the leaf; 4- leaf without the primary vein. An equal amount of each part of the plant (5.0 g) was homogenized with 15.0 ml of extraction buffer (20 mM Tris, 10 mM benzamidine-HCl, pH 7.4), filtered and centrifuged 10 minutes at 15,000 g. These four extracts were analysed for HPC content using DAS-ELISA.
HPC content of different tissues of tobacco plants was measured using DAS-ELISA. Leaves showed a higher concentration than other parts tested (Table 5). HPC concentration was lowest in the roots.
TABLE 5______________________________________HPC content of various tissues measures usingDAS-ELISA Amount of HPCPlant tissue (μg HPC/g fresh tissue)______________________________________Leaves 0.388Stem 0.274Veins 0.235Roots 0.173______________________________________
7.3 Biological activity using delay in coagulation time
The Acticlot™ assay kit (from American Diagnostica) was used. HPC + and HPC - sera, dilution buffer and solutions were prepared according to the manufacturer's instructions. Tubes, Acticlot™ activator and CaCl 2 stock solution were prewarmed to working temperature (37° C.).
Prior to testing, HPC samples were prepared as follows: 50 μl undiluted sample, 50 μl HPC deficient plasma, 400 μl American Diagnostica's dilution buffer. A 50 μl volume of this prepared sample was mixed with an equal amount of HPC deficient plasma and incubated for 2 minutes. A volume of 50 μl of Acticlot activator was mixed with the sample solution and incubated five more minutes. Finally, 50 μl of calcium chloride stock solution was added and clotting time was monitored by the tilt-tube technique.
Changes in coagulation times were observed in several experiments when tobacco extracts were tested for clotting activity. Some of the clotting assays indicated that biological activity was present.
TABLE 6______________________________________Coagulation times of a tobacco extract usingAmerican Diagnostica's Acticlot assay kit chromato chromato #9 #8 HPC HPC neg. HPC.sup.+ plasma tobacco control______________________________________Assay 1 60 sec. 44 sec. 52 sec. 107 sec.Assay 2 -- -- 145 sec. 130 sec.Assay 3 -- -- 40 sec. 60 sec.Assay 4 -- -- 140 sec. 130 sec.______________________________________
The present invention will be more readily understood by referring to the following examples which are given to illustrate the invention rather than to limit its scope.
EXAMPLE I
Expression vector pCP2 construction for the production of human protein C
A 1420 bp BclI fragment, which contained the cDNA of HPC, was cut out from pLPC and cloned into the BamHI site of vector pBI524. pBI524 is a derivative of pUC9 with, (5' to 3'), a dimer of the CaMV 35S promoter, an alfalfa mosaic virus (AMV) leader sequence, a polylinker (NcoI, XbaI, BamHI), and a NOS-T. The new construct was called pCP1. In order to verify the orientation of the cloned HPC cDNA, a BglII restriction digestion was performed on plasmid DNA isolated from recovered E. coli colonies. BglII is expected to cleave at the 3' end of the double CaMV 35S promoter and 210 bp away from the 5' end of HPC cDNA thus generating two DNA fragments of approximately 300 bp and 4800 bp if the cDNA was well oriented, that is the ATG codon from the HPC cDNA was immediately downstream of the AMV leader sequence.
An XbaI-EcoRI cassette was isolated from pCP1 and ligated in place of the XbaI-EcoRI cassette from pBI121. Therefore, the GUS gene with the NOS-T was replaced by the cDNA of HPC with its accompanying NOS-T forming the plasmid pCP2. The HPC cDNA is under the control of the constitutive CaMV 35S promoter from pBI121.
Plasmid pCP2 was transferred into A. tumefaciens LBA4404 using the freeze/thaw method. In order to verify whether the plasmids were successfully transferred, a non-radioactive Southern hybridization was performed. The cDNA of HPC was observed to hybridize to plasmid DNA isolated from A. tumefaciens and E. coli.
Seeds of Nicotiana tabacum cv. Xanthi were sterilized for 15 minutes in a 10% bleach solution with a drop of detergent (Tween™-20). Seeds were washed at least five times with sterile distilled water and allowed to germinate and grow on artificial medium composed of the basal MS salts, B5 vitamins, 3% sucrose, and 0.6% agar (Anachemia) at pH 5.7-5.8. Seed were grown under a 16 hour photoperiod with a light intensity of 50 μE and a temperature of 24° C.
A. tumefaciens was grown in Luria Broth (LB) (1% tryptone, 0.5% yeast extract, 85 mM NaCl, pH 7.0) medium supplemented with 50 μg/ml kanamycin and 25 μg/ml of streptomycin for 18 hours or until the optical density at 595 nm reached 0.5 to 1.0. Cells were spun down at 3,000 g for 5 minutes and the pellet was resuspended to its initial volume with MS-104 medium (MS basal salts, B5 vitamins, 3% sucrose, 1.0 μg/ml benzylaminopurine (BAP), 0.1 μg/ml naphtaleneacetic acid (NAA), pH 5.7-5.8, and 0.8% agar) without agar.
Leaf squares of about 64 mm 2 were dissected using a sharp scalpel, immersed in the inoculum for 15-30 minutes and plated onto MS-104 medium for 2 days under a 16 hour photoperiod, under low light intensity (20 μE) at 24° C. for cocultivation. Leaf discs were washed alternately three times with sterile distilled water for 1 minute and sterile distilled water supplemented with 500 μg/ml of carbenicillin for 5 minutes. Leaf discs were transferred to MS-104 medium with 500 μg/ml of carbenicillin for another 2 days under the same environmental conditions.
Leaf discs were washed as above, plated on MS-104 medium with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin, and grown using the above environmental conditions until calluses appeared. The light intensity was increased to 50 μE and the explants were allowed to grow until development of well-formed shoots. Shoots were excised and transferred onto MS-rooting medium (MS-104 but with 0.6% agar and no plant growth regulators) with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin. Surviving plantlets with well-formed roots were removed from the artificial medium, dipped alternately in a 0.06% 50WP Benlate solution and in a rooting powder (Stim-root #1) containing indole-3 butyric acid, and transplanted into pasteurized Promix soil mixture. Plantlets were covered with a transparent cover which was gradually lifted during the following 7 days.
EXAMPLE II
Expression vector pLG3 construction for the production of human protein C
Vector pBI524 contained an undesirable ATG which is part of the NcoI restriction site. The ATG was deleted by cleaving pBI524 with NcoI, removing single stranded sticky ends with mung bean nuclease, and ligating the modified vector which was named pLG1. The removal of the NcoI restriction site was verified with a double digestion with NcoI and ScaI. Two bands were observed when pBI524 was digested with the two restriction enzymes while only one band appeared for pLG1 indicating that the NcoI site was missing.
The HPC cDNA BclI fragment was cloned into the BamHI site of pLG1 to create pLG2. Then, a HindIII-EcoRI cassette from pLG2 was cloned in place of the HindIII-EcoRI from pBI121. Therefore, the CaMV 35S promoter along with the GUS gene and a NOS-T were replaced by a dimer of the CaMV 35S promoter with an AMV leader sequence, the cDNA of HPC, and a NOS-T.
Plasmid pLG3 was transferred into A. tumefaciens LBA4404 using the freeze/thaw method. In order to verify whether the plasmids were successfully transferred, a non-radioactive Southern hybridization was performed. The cDNA of HPC was observed to hybridize to plasmid DNA isolated from A. tumefaciens and E. coli.
Seeds of Nicotiana tabacum cv. Xanthi were sterilized for 15 minutes in a 10% bleach solution with a drop of detergent (Tween™-20). Seeds were washed at least five times with sterile distilled water and allowed to germinate and grow on artificial medium composed of the basal MS salts, B5 vitamins, 3% sucrose, and 0.6% agar (Anachemia) at pH 5.7-5.8. Seed were grown under a 16 hour photoperiod with a light intensity of 50 μE and a temperature of 24° C.
A. tumefaciens was grown in Luria Broth (LB) (1% tryptone, 0.5% yeast extract, 85 mM NaCl, pH 7.0) medium supplemented with 50 μg/ml kanamycin and 25 μg/ml of streptomycin for 18 hours or until the optical density at 595 nm reached 0.5 to 1.0. Cells were spun down at 3,000 g for 5 minutes and the pellet was resuspended to its initial volume with MS-104 medium (MS basal salts, B5 vitamins, 3% sucrose, 1.0 μg/ml benzylaminopurine (BAP), 0.1 μg/ml naphtaleneacetic acid (NAA), pH 5.7-5.8, and 0.8% agar) without agar.
Leaf squares of about 64 mm 2 were dissected using a sharp scalpel, immersed in the inoculum for 15-30 minutes and plated onto MS-104 medium for 2 days under a 16 hour photoperiod, under low light intensity (20 μE) at 24° C. for cocultivation. Leaf discs were washed alternately three times with sterile distilled water for 1 minute and sterile distilled water supplemented with 500 μg/ml of carbenicillin for 5 minutes. Leaf discs were transferred to MS-104 medium with 500 μg/ml of carbenicillin for another 2 days under the same environmental conditions.
Leaf discs were washed as above, plated on MS-104 medium with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin, and grown using the above environmental conditions until calluses appeared. The light intensity was increased to 50 μE and the explants were allowed to grow until development of well-formed shoots. Shoots were excised and transferred onto MS-rooting medium (MS-104 but with 0.6% agar and no plant growth regulators) with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin. Surviving plantlets with well-formed roots were removed from the artificial medium, dipped alternately in a 0.06% 50WP Benlate solution and in a rooting powder (Stim-root #1) containing indole-3 butyric acid, and transplanted into pasteurized Promix soil mixture. Plantlets were covered with a transparent cover which was gradually lifted during the following 7 days.
EXAMPLE III
Expression vector construction for the production of chicken nuclear oncoprotein p53
Proceeding as for Example I, but using a cDNA sequence coding for chicken nuclear oncoprotein p53 instead of the cDNA of the human protein C gene.
Vector pBI524 contained an undesirable ATG which is part of the NcoI restriction site. The ATG was deleted by cleaving pBI524 with NcoI, removing single stranded sticky ends with mung bean nuclease, and ligating the modified vector which was named pLG1. The removal of the NcoI restriction site was verified with a double digestion with NcoI and ScaI. Two bands were observed when pBI524 was digested with the two restriction enzymes while only one band appeared for pLG1 indicating that the NcoI site was missing.
The chicken cDNA for nuclear oncoprotein p53 is excised using EcoRI restriction digestion. T4 DNA polymerase is used to fill in the 3' recessed end and therefore eliminate the EcoRI site. BamHI linkers (5'-CGGATCCG-3') are added by ligation with T4 DNA ligase. The BamHI ends are then digested with BamHI and ligated into the BamHI site of pLG1 to create pLG53. Then, a HindIII-EcoRI cassette from pLG2 is cloned in place of the HindIII-EcoRI from pBI121. Therefore, the CaMV 35S promoter along with the GUS gene and a NOS-T were replaced by a dimer of the CaMV 35S promoter with an AMV leader sequence, the cDNA of HPC, and a NOS-T. Plasmids pLG53 is transferred into A. tumefaciens LBA4404 using the freeze/thaw method.
Seeds of Nicotiana tabacum cv. Xanthi are sterilized for 15 minutes in a 10% bleach solution with a drop of detergent (Tween™-20). Seeds are washed at least five times with sterile distilled water and allowed to germinate and grow on artificial medium composed of the basal MS salts, B5 vitamins, 3% sucrose, and 0.6% agar (Anachemia) at pH 5.7-5.8. Seed are grown under a 16 hour photoperiod with a light intensity of 50 μE and a temperature of 24° C.
A. tumefaciens is grown in Luria Broth (LB) (1% tryptone, 0.5% yeast extract, 85 mM NaCl, pH 7.0) medium supplemented with 50 μg/ml kanamycin and 25 μg/ml of streptomycin for 18 hours or until the optical density at 595 nm reaches 0.5 to 1.0. Cells are spun down at 3,000 g for 5 minutes and the pellet is resuspended to its initial volume with MS-104 medium (MS basal salts, B5 vitamins, 3% sucrose, 1.0 μg/ml benzylaminopurine (BAP), 0.1 μg/ml naphtaleneacetic acid (NAA), pH 5.7-5.8, and 0.8% agar) without agar.
Leaf squares of about 64 mm 2 are dissected using a sharp scalpel, immersed in the inoculum for 15-30 minutes and plated onto MS-104 medium for 2 days under a 16 hour photoperiod, under low light intensity (20 μE) at 24° C. for cocultivation. Leaf discs are washed alternately three times with sterile distilled water for 1 minute and sterile distilled water supplemented with 500 μg/ml of carbenicillin for 5 minutes. Leaf discs are transferred to MS-104 medium with 500 μg/ml of carbenicillin for another 2 days under the same environmental conditions.
Leaf discs are washed as above, plated on MS-104 medium with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin, and grown using the above environmental conditions until calluses appeared. The light intensity is increased to 50 μE and the explants allowed to grow until development of well-formed shoots. Shoots are excised and transferred onto MS-rooting medium (MS-104 but with 0.6% agar and no plant growth regulators) with 500 μg/ml of carbenicillin and 100 μg/ml of kanamycin. Surviving plantlets with well-formed roots are removed from the artificial medium, dipped alternately in a 0.06% 50WP Benlate solution and in a rooting powder (Stim-root #1) containing indole-3 butyric acid, and transplanted into pasteurized Promix soil mixture. Plantlets are covered with a transparent cover which is gradually lifted during the following 7 days.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims. | The present invention relates to an expression vector for the large scale production of a human or animal protein, which comprises a DNA construct consisting of operatively linked DNA coding for a plant promoter, a transcription terminator and the human or animal protein to be expressed. Such human or animal proteins may be selected from the group consisting of human protein C (HPC), factor VIII, growth hormone, erythropoietin, interleukin 1 to 7, colony stimulating factors, relaxins, polypeptide hormones, cytokines, growth factors and coagulation factors. The present invention also relates to the plant bioreactor and to the method for the large scale production of human or animal proteins. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This application is related to U.S. Ser. No. 06/587,532, entitled, "Load Cell Mass Comparator", filed in the names of Thomas F. Scrivener and Randall M. Schoonover, on Mar. 8, 1984, and is assigned to the assignee of this invention.
BACKGROUND OF THE INVENTION
To overcome the disadvantages experienced in the calibration of mass standards employing conventional mechanical balances, it has been proposed to use a strain gauge load cell which produces an electric signal in proportion to the force exerted on the cell. Typically, a plurality of strain gauges are located in the cell and are internally connected in the form of a bridge circuit, the output of which is connected to electronic measuring and recording equipment. Where the electronic measuring circuit is comprised of a low noise, high stability electronic circuit, wide fluctuations at the output of the bridge circuit due to temperature drift is not only undesireable, but intolerable where difference measurements are made betwen a standard weight and a test weight.
Accordingly, the present invention is directed to an improved bridge circuit formed by the strain qauges located in the load cell of a load cell mass comparator. The bridge circuit is modified for use as a difference transducer by coupling a temperature compensating circuit between ends of strain gauges in adjacent arms of the bridge. The compensating circuit is located remotely from the load cell containing the strain gauges and is comprised of a pair of relatively low valued series connected low noise, drift free precision resistors, which are respectively shunted by relatively high valued resistive potentiometers which are used for balancing the bridge. One potentiometer additionally includes a series connected relatively high valued low noise, drift free precision resistor for providing a means for providing fine balance of the bridge, while the other potentiometer is used for providing coarse balance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a mechanical schematic diagram of a load cell mass comparator utilized in connection with the present invention;
FIG. 2 is an electrical schematic diagram of a typical prior art bridge circuit of strain gauges located in the load cell mass comparator shown in FIG. 1; and
FIG. 3 is an electrical schematic diagram of the preferred embodiment of the subject invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and more particularly to FIG. 1, there is shown a load cell mass comparator of the type shown and described in the above referenced related application, U.S. Ser. No. 587,532 filed Mar. 8, l984, now U.S. Pat. No. 4,523,653. As shown in FIG. 1, reference numeral 1 denotes a conventional load cell which may be, for example, a type manufactured by Revere Corporation of America, and which includes a plurality of strain gauges, not shown, internally wired together to form a Wheatstone bridge such as shown in FIG. 2 and which additionally includes an output cable 2 for being coupled to an externally located supply and measuring circuit, not shown.
The load cell 1 is connected at its upper end to a floating plate 3 through a self aligning coupling such as a universal joint assembly 4. The floating plate 3 is slidably mounted on a plurality of guide rods 5 extending between a fixed upper plate 6 and a fixed lower plate 7. A spring and shock absorber assembly shown schematically by reference numeral 8 is mounted between the floating plate 3 and the upper fixed plate 6. The lower end of the load cell 1 is connected to the mass to be calibrated, not shown, through a second self-aligning coupling 9, a thrust bearing 10, and a load stop bearing 11. The mass to be calibrated is connected to an eyelet 12 provided on the lower end of a rod 13 connected to the thrust bearing 10 and the load stop bearing 11. Another eyelet 14 is secured to the upper fixed plate 6 through a hydraulic cylinder 15 so that the entire assembly may be suspended from a suitable support and the comparator can be loaded and unloaded by actuation of the hydraulic cylinder.
As force is applied to the load cell 1, minute deflections are imposed on the internally located strain gauges resulting in changes in the cross section thereof. As is well known, the strain gauges are electrical components whose resistance changes upon the application of external force. Accordingly, the strain gauges in the load cell 1 are represented as resistors R 1 , R 2 , R 3 and R 4 in both FIGS. 2 and 3 and are connected in a bridge circuit configuration. With a fixed excitation voltage applied across the bridge, for example, at terminals 16 and 17 (FIG. 2) and which are connected to a first pair of mutually opposing circuit junctions 18 and 19, the bridge becomes unbalanced and an output voltage is generated across a second pair of mutually opposing junctions 20 and 21. The output voltage is then coupled to the output terminals 22 and 23 and is proportional to the applied load, which when coupled to the measuring circuit, not shown, can be appropriately amplified, displayed, printed or otherwise interfaced to a fully automated control system.
In order to compensate for temperature changes experienced by the load cell 1 and the strain gauges included therein, reference is now made to FIG. 3 which discloses the preferred embodiment of the invention which comprises a modification to the bridge circuit shown in FIG. 2. Accordingly, an integrated strain gauge supply, measuring and recording instrument 24 is shown located remotely from the load cell mass comparator containing the load cell 1 by a distance d which may be, for example, 25 feet or more. The inventive concept is directed to an external resistive type compensation circuit connected into output junction 21 (FIG. 2) intermediate the output side of the strain gauges R 2 and R 3 , which form two adjacent forms of the bridge. The compensating circuit 25, moreover, is preferably located remote from the strain gauge bridge, such as being located in close proximity to or incorporated with the measuring instrument 24 and thus being separated from the bridge by the distance d.
The temperature compensation circuit 25 is comprised of a pair of series connected precision resistors having fixed values of relatively low resistance in comparison to the resistance values of the strain gauge elements R 1 , R 2 , R 3 and R 4 but exhibiting low noise and low temperature drift characteristics. The precision resistors 26 and 27 are shown in FIG. 3 coupled between the terminals 21 a and 21 b by means of electrical connecting leads 28 and 29 which span the length d.
The addition of the two precision resistor elements 26 and 27 permit two additional points in the bridge to be accessed electrically, namely the circuit junctions 30, 31 and 32 instead of the single junction 21, as shown in FIG. 2. The compensating circuit 25 in addition to two series resistors 26 and 27, however, additionally includes circuit means which permits the bridge to be balanced during operation, i.e., when it is under strain because of an applied load. The balancing means comprises a pair of relatively high valued variable resistances in the form of potentiometers 33 and 34, respectively shunting the low valued precision resistors 26 and 27. One potentiometer, specifically potentiometer 33 additionally includes a series connected high valued precision resistor of fixed value so that the potentiometer 33 can be utilized as a means for fine balance, whereas the single potentiometer 34 coupled across the resistor 27 can be utilized to provide a coarse balance. The slider of the potentiometer 34, moreover, is coupled to an output lead 36 which couples to terminal 22 which is shown in FIG. 3 located on the measuring instrument 24 along with terminal 23 which connects back to the other output junction 20 of the bridge by circuit lead 37.
The values of the two potentiometers 33 and 34 as well as the third fixed resistor 35 are selected to be of a much greater resistance value than the pair of fixed resistors 26 and 27 so that the operation of the potentiometers 33 and 34 will not degrade the performance of the bridge and as a result can be nulled at any load within its capacity since there will always be a point between terminals 21 a and 21 b which will be at the same potential as the opposing output circuit junction 20.
In operation, the null appearing at output terminals 22 and 23 is first determined by weighing a standard mass. Then the mass to be calibrated is weighed. The strain gauge bridge which was previously nulled by using the standard mass will then indicate the difference between the weight to be calibrated and the standard weight. The temperature stability of the configuration as shown in FIG. 3 is significantly improved over the standard or conventional prior art method as shown in FIG. 2 because the additional precision resistors have a value which is small in relation to the resistance of the strain gauge elements R 1 , R 2 , R 3 and R 4 and are connected such that the symmetry of the bridge is preserved.
In the event that a fine adjustment of bridge balance is not required, the fine balance potentiometer 33 and the series connected fixed precision resistor 35 can be eliminated, leaving only the pair of low value precision resistors 26 and 27 connected between the terminals 21 a and 21 b and with but a single potentiometer such as potentiometer 34 shunting one of the precision resistors.
It is to be understood that the embodiment of the invention herewith shown and described is to be taken as a preferred example and being shown for purposes of illustration and not limitation. Accordingly, various changes, modifications, and alterations may be resorted to without departing from the spirit of the invention or scope of the subjoined claims. | The strain gauge bridge circuit located in the load cell of a load cell mass comparator is modified to provide temperature stability by coupling a remotely located temperature compensating circuit between the two normally connected output ends of strain gauges in adjacent arms of the bridge. The compensating circuit is comprised of a pair of series connected low noise, drift free precision resistors of relatively low resistance value compared to the resistance of the strain gauges. The precision resistors are shunted by relatively high valued potentiometers which operate to balance the bridge. One potentiometer additionally includes a series connected high value precision resistor for providing fine balance while the other potentiometer is used for coarse balance. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
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REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates generally to optics. More particularly, the invention provides techniques for correcting optical aberrations. Merely by way of example, the invention has been applied to optical mirrors, but it would be recognized that the invention has a much broader range of applicability.
Optical system has been widely used for detecting images of various targets. The optical system usually introduces discrepancies to the images. The discrepancies including phase errors result from various sources, such as aberrations associated with individual segments of optical system including optical mirrors and discrepancies between input and output of optical system. These errors often need to be estimated and corrected in order to improve image quality. For example, a space telescope such as the James Webb Space Telescope may have large phase errors after its deployment, and these aberrations often need to be corrected with the telescope remaining in space.
In order to correct the optical aberrations, a Green's function approach has been proposed. This method derives the transport of intensity equation and solves for the auxiliary function. In other words, the Green's function approach uses known phase or phase gradient at the boundary of optical aperture of the optical system and determines the phase map of the entire optical aperture. Applied to an astronomical telescope, this method measures irradiance on either side of telescope focus and radial gradient of wavefront at the edge of telescope aperture. Irradiance measurements do not need to be performed on planes symmetrically located on either side of telescope focus. Consequently, a Poisson equation is solved to obtain the wavefront error in the interior of the telescope aperture.
When the wavefront error of an aperture is large, the Green's function approach usually cannot effectively sample the entire optical aperture. Instead, the optical aperture is usually divided into several sub-apertures, and phases within each sub-aperture are measured. Phase errors in each sub-aperture are then determined and corrected. Afterwards, sizes of sub-apertures are increased, and phase errors within enlarged sub-apertures are further corrected. Through iterations, phase errors within the aperture become so small that the entire aperture may be sampled. This iterative sub-aperture approach requires additional masks and setups, and may even require several iterative corrections at each sub-aperture size. Hence this method is costly and time consuming.
In addition, the above method sometimes uses curvature-based wavefront sensing. This sensing technique requires information about radial derivative of phase at the boundary of optical aperture. For large mirrors with several segments, a large number of boundary radial derivatives need to be determined. Hence this method may be cumbersome.
FIG. 1 is a simplified diagram illustrating technique for phase error correction. The correction method includes at least five processes: secondary mirror alignment process 110 , coarse tilt adjustment process 120 , coarse petal figuring process 130 , inter-petal phasing process 140 , tilt/figure refinement process 150 , and full aperture figuring process 160 . Inter-petal phasing process 140 and tilt/figure refinement process 150 may be performed iteratively. As shown in FIG. 1 , processes 110 , 120 , 130 , and 140 use different pupil plane masks 112 , 122 , 132 , 142 , and 152 respectively. In addition, processes 110 , 130 , 150 , and 160 use additional hardware. For example, process 110 uses Phase Diverse Phase Retrieval (“PDPR”) plates 114 , process 130 uses fine steering mirror 134 , process 150 uses PDPR plates 154 and fine steering mirror 155 , and process 160 uses PDPR plates 164 . At secondary mirror alignment process 110 , point source functions (“PSFs”) in focal plane and defocus planes are measured, and sharpness maximization and PDPR analysis are performed. At coarse tilt adjustment process 120 , PSFs for each petal is measured, and centroid analysis is performed. At coarse petal figuring process 130 , PSFs for each sub-aperture is measured, and analysis based on PSF maximization algorithm is performed. At inter-petal phasing process 140 , grism fringes are measured, and fringe analysis is performed. At tilt/figure refinement process 150 , PSFs for each petal in focal plane and defocus planes are measured, and centroid analysis and PDPR analysis are performed. At full aperture figuring process 160 , PSFs for entire aperture in focal plane and defocus planes are measured, and PDPR analysis is performed.
Hence it is desirable to simplify and improve phase correction technique.
BRIEF SUMMARY OF THE INVENTION
The present invention relates generally to optics. More particularly, the invention provides techniques for correcting optical aberrations. Merely by way of example, the invention has been applied to optical mirrors, but it would be recognized that the invention has a much broader range of applicability.
According to one embodiment of the present invention, a method for estimating and correcting an aberration of an optical system includes capturing a first plurality of images on a first plurality of planes. The first plurality of images is formed by at least the optical system. Additionally, the method includes processing at least information associated with the first plurality of images, and determining a first auxiliary function based upon at least the information associated with the first plurality of images. The first auxiliary function represents a first aberration of the optical system. Moreover, the method includes adjusting the optical system based upon at least information associated with the first auxiliary function.
According to another embodiment of the present invention, a method for estimating and correcting an aberration of an optical system includes capturing a first plurality of images on a first plurality of planes. The first plurality of images is formed by at least the optical system. Additionally, the method includes processing at least information associated with the first plurality of images, and determining a first auxiliary function based upon at least the information associated with the first plurality of images. The first auxiliary function represents a first aberration of the optical system. Moreover, the method includes adjusting the optical system based upon at least information associated with the first auxiliary function. The capturing, the processing, the determining, and the adjusting are free from dividing an aperture of the optical system into a plurality of sub-apertures, estimating an aberration for each sub-aperture, or reducing the aberration for each sub-aperture.
According to yet another embodiment of the present invention, a method for estimating and correcting an aberration of an optical system includes capturing a plurality of images on a plurality of planes. The plurality of images is formed by at least the optical system. Additionally, the method includes measuring a plurality of intensities for each of the plurality of images. The plurality of intensities corresponds to a plurality of locations on each of the plurality of planes respectively. Moreover, the method includes obtaining a plurality of derivatives of intensity with respect to an optical axis of the optical system using at least information associated with the plurality of intensities. The plurality of derivatives corresponds to the plurality of locations on a focal plane of the optical system. Also, the method includes determining a first auxiliary function based upon at least information associated with the plurality of derivatives. The first auxiliary function represents an aberration of the optical system.
According to yet another embodiment of the present invention, a system for estimating and correcting an aberration of an optical system includes a testing system, a control system connected to the testing system, and an adjustment system connected to the testing system and to the control system. The testing system and the control system are configured to capture a plurality of images on a plurality of planes. The plurality of images is formed by at least the optical system. The control system is configured to process at least information associated with the plurality of images and determine an auxiliary function based upon at least the information associated with the plurality of images. The first auxiliary function represents a first aberration of the optical system. The adjustment system and the control system are configured to adjust the optical system based upon at least information associated with the auxiliary function.
The techniques of the present invention have numerous advantages. Certain embodiments of the present invention can sense and correct aberrations on the entire aperture of an optical system without dividing the aperture into sub-apertures. The amount of time required for aberration reduction may be shortened. Some embodiments of the present invention work for segmented apertures. Certain embodiments of the present invention can improve aberration reduction by iterations. The iterative process alleviates convergence problem encountered by conventional techniques. Some embodiments of the present invention can simplify hardware requirements for aberration reduction, such as hardware requirements for coarse alignments of large telescopes. Certain embodiments of the present invention do not use the Pseudo-Hartmann mask, which is often used by conventional techniques for coarse figuring. Conventional techniques for coarse figuring often require Pseudo-Hartmann masks, each of which is made up of sets of several multi-faceted prisms. Fabrication of the masks is difficult, time consuming and costly. Therefore, certain embodiments of the present invention can lower the cost and shorten the time for aberration reduction. Some embodiments of the present invention usually can be implemented with minimum computation time.
Depending upon the embodiment under consideration, one or more of these benefits may be achieved. These benefits and various additional objects, features and advantages of the present invention can be fully appreciated with reference to the detailed description and accompanying drawings that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified diagram illustrating technique for phase error correction.
FIG. 2 is a simplified block diagram for correcting optical aberrations according to one embodiment of the present invention.
FIG. 3 illustrates a simplified geometry for process of intensity measurement according to one embodiment of the present invention.
FIGS. 4A through 4D illustrate measured image intensities on different planes with aberrations on mirror surface.
FIGS. 5A through 5D illustrate measured image intensities on different planes with other aberrations on mirror surface.
FIGS. 6A through 6D illustrate measured image intensities on different planes with yet other aberrations on mirror surface.
FIG. 7 is a simplified system for estimation and correction of aberrations according to one embodiment of the present invention.
FIG. 8 is a simplified system for estimation and correction of aberrations according to another embodiment of the present invention.
FIG. 9 is a simplified system for estimation and correction of large aberrations according to yet another embodiment of the present invention.
FIGS. 10A through 10C show simplified experimental results according to yet another embodiment of the present invention.
FIG. 11 shows actuator commands for each iteration of aberration reduction process.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates generally to optics. More particularly, the invention provides techniques for correcting optical aberrations. Merely by way of example, the invention has been applied to optical mirrors, but it would be recognized that the invention has a much broader range of applicability.
FIG. 2 is a simplified block diagram for correcting optical aberrations according to one embodiment of the present invention. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. The method of correcting optical aberrations includes process 210 for intensity measurement, process 220 for derivative estimation, process 230 for aberration determination, process 240 for aberration reduction, and process 250 for additional measurement determination. Although the above has been shown using a selected sequence of processes, there can be many alternatives, modifications, and variations. For example, some of the processes may be expanded and/or combined. For example, process 220 of derivative estimation and process 230 of aberration determination may be combined. Other processes may be inserted to those noted above. For example, conventional phase diversity process for aberration reduction may be used in combination with processes 210 , 220 , 230 , 240 , and 250 . Depending upon the embodiment, the specific sequences of steps may be interchanged with others replaced. Process 240 for aberration reduction is optional and may be skipped under certain conditions. Further details of these processes are found throughout the present specification and more particularly below.
At process 210 of intensity measurement, optical images are formed on various planes and image intensities are measured. The planes may be located on either side of focal plane or optionally coincide with the focal plane. If aberrations of the optical system do not change image intensities on a certain plane, image intensities on this plane do not need to be measured. The skipped plane may be the focal plane or a defocus plane of the optical system. The optical system may be a telescope, a mirror, or any system with an optical aperture. Measured image intensities describe intensity as a function of location on respective planes.
FIG. 3 illustrates a simplified geometry for process 210 of intensity measurement according to one embodiment of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 3 , optical system 310 with optical aberrations has an optical axis z. Focal plane 320 of optical system 310 is located at z equal to zero. Positions of defocus planes are measured by z values. Z value is larger than zero for defocus planes, such as plane 330 , located on the right side of focal plane 320 , as shown in FIG. 3 . Similarly, z value is smaller than zero for defocus planes, such as plane 340 , located to the left side of focal plane 320 , as shown in FIG. 3 . Locations on each plane are measured by x and y values. Hence measured intensities depend on x, y, and z. More specifically, measured intensities may include I measure (x,y,z 1 ), I measure (x,y,z 2 ), . . . , I measure (x,y,z n ), . . . , I measure (x,y,z N ), where N is a positive integer representing the number of different planes on which image intensities are measured. For example, N may be equal to 2, 3, 100, or any other positive integer.
At process 220 of derivative estimation, the derivative of measured intensities taken along the z axis at z equal to zero is estimated as shown below.
D
(
x
,
y
)
=
∂
I
(
x
,
y
,
z
)
∂
z
❘
z
=
0
(
Equation
1
)
where I(x,y,z) is image intensity as a function of x, y, and z. D(x,y) is the derivative of intensity taken along the z axis at z equal to zero. z equal to zero corresponds to location of the focal plane, so D(x,y) is effectively the derivative of I(x,y,z) along the z direction on the focal plane.
D(x,y) may be estimated with various methods. For example, D(x,y) may be obtained if I(x,y,z) is obtained within at least the vicinity of the focal plane, i.e., −a<z<b, where a and b is larger than or equal to zero. Preferably a and b are both larger than zero. I(x,y,z) may be estimated by fitting measured intensities on various planes to a function. The measured intensities includes I measure (x,y,z 1 ), I measure (x,y,z 2 ), . . . , I measure (x,y,z n ), I measure (x,y,z N ). The function that can describe I(x,y,z) in the vicinity of the focal plane may include at least
∑ m = 0 M a m ( x , y ) z m ,
where M is an arbitrary positive integer. a m (x,y) varies with x and y but is independent of z. For example,
when M= 1 , I ( x,y,z )= a 0 ( x,y )+ a 1 ( x,y )× z (Equation 2)
when M= 2 , I ( x,y,z )= a 0 ( x,y )+ a 1 ( x,y )× z+a 2 ( x,y )× z 2 (Equation 3)
when M= 3 , I ( x,y,z )= a 0 ( x,y )+ a 1 ( x,y )× z+a 2 ( x,y )× z 2 +a 3 ( x,y )× z 3 (Equation 4)
Magnitude of M determines the minimum number of different planes on which image intensities need to be measured at process 210 of intensity measurement. N usually needs to be larger than M. Regardless of magnitude of M, a m (x,y) is usually estimated with measured intensities such as I measure (x,y,z), I measure (x,y,z 2 ), . . . , I measure (x,y,z n ), . . . , I measure (x,y,z N ).
Coefficients of a fitting function I(x,y,z) may be estimated by the least square fit method. I(x,y,z) may be
∑ m = 0 M a m ( x , y ) z m
or any other function. For example,
∑ m = 0 M a m ( x , y ) z m
has coefficients a m (x,y), where 0≦m≦M. The least square fit method assesses closeness of the fitting function I(x,y,z) to measured intensities as follows.
χ
2
=
∫
∫
ImagingArea
[
∑
i
=
1
N
(
I
measure
(
x
,
y
,
z
i
)
-
I
(
x
,
y
,
z
)
I
measure
(
x
,
y
,
z
i
)
)
2
]
ⅆ
x
ⅆ
y
(
Equation
5
)
where ImagingArea covers the area on a plane where any respective one of I measure (x,y,z 1 ), I measure (x,y,z 2 ), . . . , I measure (x,y,z n ), . . . , I measure (x,y,z N ) is captured. By minimizing χ 2 , the least square fit method finds values of coefficients, such as a m (x,y) for
∑
m
=
0
M
a
m
(
x
,
y
)
z
m
.
In addition, the least square fit method may also be used to compare capabilities of various fitting functions to describe measured intensities. For each fitting function, its coefficients may be determined by minimizing χ 2 . The resulting χ 2 minimums for different fitting functions may be different. The fitting function with the smallest χ 2 minimum usually provides the best fit to the measured intensities, and may be chosen to calculate D(x,y) according to Equation 1.
At process 230 of aberration determination, the aberration of the optical system is obtained. The aberration is described by a function called Ψ(x,y,z) at z equal to zero. Ψ(x,y,z) is called auxiliary function. Ψ(x,y,0) can be calculated as follows:
2
π
λ
D
(
x
,
y
)
=
-
∇
2
Ψ
(
x
,
y
,
0
)
where
(
Equation
6
)
∇
2
=
∂
2
∂
x
2
+
∂
2
∂
y
2
(
Equation
7
)
At process 240 of aberration reduction, the optical system is adjusted in order to reduce aberrations. The adjustment may be performed with various methods. For example, surface of an optical mirror may be polished. Also, surface of an optical mirror may be adjusted with actuators. Actuators may be placed on the backside of the mirror. In order to use actuators to reduce aberrations on optical mirror, the relationship between settings of actuators and aberrations, also called influence function, needs to be determined. The influence function may be obtained by measuring influence function data and fitting the measured data to an influence function. The fitting process may use the least square fit method or any other fitting method. The influence function may take the form of various functions. In addition, measurements of influence function data and fitting of the influence function may be performed before process 240 , during process 240 , or combination thereof. Further, process 240 may be skipped if process 230 of aberration determination shows that aberrations are sufficiently small.
At process 250 of additional measurement determination, the need for any additional intensity measurement is determined. For example, if process 230 has determined that aberrations are small or if process 240 has been skipped, no additional measurement may be needed. Other factors may also affect the need for additional intensity measurement, such as time, cost, and performance requirement. If process 250 determines an additional measurement is needed, processes 210 , 220 , 230 , and 240 may be performed. As discussed above, process 240 may be skipped.
In order to effectively reduce aberrations through iterations of processes 210 , 220 , 230 , and 240 , process 210 of intensity measurement may be performed on different sets of planes at different iterations. For example, I measure (x,y,z 1 ), I measure (x,y,z 2 ), . . . , I measure (x,y,z n ), . . . , I measure (x,y,z N ) may be measured on planes having greater distances from the focal plane than respective planes from the focal plane at the previous performance of process 210 . Therefore z 1 , z 2 , . . . , z n , . . . , z N at a subsequent iteration may be larger than z 1 , z 2 , . . . , z n , . . . , z N for previous performance of process 210 respectively. Alternatively, the subsequent iteration may use z 1 , z 2 , . . . , z n , . . . , z N all which are the same as those used for previous measurement respectively. Subsequent iteration may use z 1 , z 2 , . . . , z n , . . . , z N some of which are the same as and rest of which are different from those used for previous measurement respectively. Subsequent iteration may measure intensities on the same number of planes as previous performance of process 210 . Subsequent iteration may measure intensities on different number of planes than previous performance of process 210 .
FIGS. 4A through 4D illustrate measured image intensities on different planes with aberrations on mirror surface. The measurements are merely examples, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 4(A) , direct measurements by Michelson interferometer shows that mirror surface 410 has a valley and a bump in or around center region 412 . These aberrations create bright area 422 and dark area 424 on image 420 that is captured on a plane located farther away from mirror surface 410 than the focal plane from mirror surface 410 by 11 mm, as shown in FIG. 4B . Hence the image plane has a z value of 11 mm as defined in FIG. 3 . In FIG. 4C , image 430 is captured on a plane having a z value of 20 mm. Bright area 432 and dark area 434 indicates the existence of aberrations on mirror surface 410 . Similarly, image 440 is captured on a plane having a z value of −20 mm. Dark area 442 and bright area 444 indicate the existence of aberrations on mirror surface 410 . By comparison, images 430 and 440 are captured on planes symmetrically located on opposite sides of the focal plane. Bright area 432 is located in roughly the same location as dark area 442 ; dark area 434 is located in roughly the same location as bright area 444 . In addition, both images 430 and 440 are captured on planes further away from the focal plane than image 420 from the focal plane. Consequently, areas 432 , 434 , 442 , and 444 have generally bigger sizes and stronger contrasts than areas 422 and 424 . Hence images captured on planes further away from the focal plane usually reflects aberrations on mirror surface more sensitively than images captured on planes closer to the focal plane.
FIGS. 5A through 5D illustrate measured image intensities on different planes with other aberrations on mirror surface. The measurements are merely examples, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 5A , measured Michelson fringes show that mirror surface 510 has a bump and a valley in or around center area 512 . But the bump and valley in FIG. 5A are not as severe as those in FIG. 4A . Consequently, the low bump or the shallow valley does not create strong intensity variations on the plane at z equal to 11 mm, as shown in image 520 of FIG. 5B . In contrast, image 530 captured at z equal to 20 mm has bright area 532 and dark area 534 , as shown in FIG. 5C . Similarly, FIG. 5D shows dark area 542 and bright area 544 on image 540 captured at z equal −20 mm.
FIGS. 6A through 6D illustrate measured image intensities on different planes with yet other aberrations on mirror surface. The measurements are merely examples, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 6A , measured Michelson fringes show that mirror surface 610 has a bump and a valley in or around center area 612 . But the bump and valley in FIG. 6A are not as severe as those in FIGS. 4A and 5A . As shown in FIGS. 5B , 5 C, and 5 D, images 620 , 630 , and 640 are captured at z equal to 11 mm, 20 mm, and 40 mm respectively. For image 640 , there appear bright area 642 and dark area 644 reflecting aberrations on mirror surface 610 . Also, image 640 shows locations of actuators attached to the back of mirror surface 610 , such as locations 646 and 648 .
FIG. 7 is a simplified system for estimation and correction of aberrations according to one embodiment of the present invention. The system is merely an example, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. System 700 includes light source 710 , lens 720 , beam splitter 730 , lens 740 , mirror 750 , and image detector 760 . Although the above has been shown using systems 710 through 760 , there can be many alternatives, modifications, and variations. For example, some of the systems may be expanded and/or combined. Lens 720 may be expanded to several lenses. Also, lens 740 may be expanded to several lenses. Other systems may be inserted to those noted above. Depending upon the embodiment, the specific systems may be replaced. For example, mirror 750 may be replaced by a telescope or other system with optical aperture. Further details of these systems are found throughout the present specification and more particularly below.
As shown in FIG. 7 , light source 710 is a point light source such as a laser source combined with a pin-hole or a fiber-optic, and is placed at the focal point of lens 720 . Light source 710 generates radiation with substantially spherical wavefront. The radiation is converted into collimated beam 722 by lens 720 . Collimated beam 722 travels to beam splitter 730 and is partially reflected to form collimated beam 732 . Beam 732 travels to lens 740 and is converted into beam 744 . Lens 740 focuses beam 744 to focal point 742 , which is also the center of curvature for mirror 750 . Beam 744 travels to focal point 742 and then spreads out to reach mirror 750 . Mirror 750 reflects beam 744 to form beam 752 and focuses beam 752 at focal point 742 . Passing through focal point 742 , beam 752 is then collimated by lens 740 and reaches beam splitter 730 . Beam 752 partially passes through beam splitter 730 and then forms images on planes located either at focal plane 762 of mirror 750 or on either side of focal plane 762 . The images, including their intensities, are captured by image detector 760 . Image detectors 760 may be any detecting device that can measure intensities of images. System 700 may be used to perform method for estimation and correction of aberrations of mirror 750 including process 210 for intensity measurement as shown in FIG. 2 . For example, an aberration includes a hill and a valley on the aperture. The vertical distance between the top of the hill and the bottom of the valley is at least one wavelength of radiation from the light source 710 .
FIG. 8 is a simplified system for estimation and correction of aberrations according to another embodiment of the present invention. The system is merely an example, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications.
FIG. 9 is a simplified system for estimation and correction of large aberrations according to yet another embodiment of the present invention. The system is merely an example, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. System 900 includes testing system 910 , control system 920 , and adjustment system 930 . Although the above has been shown using systems 910 , 920 , and 930 , there can be many alternatives, modifications, and variations. For example, some of the systems may be expanded and/or combined. For example, testing system 910 and testing 930 may be combined. Other systems may be inserted to those noted above. For example, system for performing conventional phase diversity process may be added. Depending upon the embodiment, the specific systems may be replaced. Further details of these systems are found throughout the present specification and more particularly below.
Testing system 910 may have some or all components of system 700 as described in FIG. 7 . Control system 920 may be a personal computer, a server, a customized processor, or any other system. Control system 920 may perform process 220 for derivative estimation, process 230 for aberration determination, and process 250 of additional measurement determination as described in FIG. 2 . In addition, control system 920 and testing system 910 may perform process 210 of intensity measurement. Adjustment system 930 may include polishing system, actuators, or combination thereof. For example, actuators may be placed on the backside of mirror 750 if testing system 910 has at least some components of system 700 . Optical adjustment system 930 and control system 920 may perform process 240 for aberration reduction.
In addition, control system 920 may include code that automatically directs testing system 910 , control system 920 , and adjustment system 930 to perform the inventive process 210 for intensity measurement, process 220 for derivative estimation, process 230 for aberration determination, process 240 for aberration reduction, and process 250 for additional measurement determination. The computer code may be implemented in Matlab, C++, or any other computer language.
FIGS. 10A through 10C show simplified experimental results according to yet another embodiment of the present invention. The experiment is merely an example, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. In the experiment, mirror surface is measured by Michelson interferometer before any aberration reduction process and after each aberration reduction process in order to examine effectiveness of method and system of the present invention. As shown in FIG. 10A , mirror surface has certain aberrations. After the first aberration reduction process is performed according to the present invention, the measured Michelson fringes show reduced aberrations on the mirror surface, as shown in FIG. 10B . After four iterations of aberration reduction processes, the aberrations on the mirror surface are almost eliminated, as shown in FIG. 10C .
FIG. 11 shows actuator commands for each iteration of aberration reduction process as described in FIGS. 10A through 10C . The actuator commands are merely examples, which should not unduly limit the scope of the present invention. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For each actuator, the magnitude of correction usually decreases with number of iteration. In the meantime, the magnitudes of optical aberrations also decrease with number of iteration, as shown in FIGS. 10 through 10C .
The techniques of the present invention have numerous advantages. Certain embodiments of the present invention can sense and correct aberrations on the entire aperture of an optical system without dividing the aperture into sub-apertures. The amount of time required for aberration reduction may be shortened. Some embodiments of the present invention work for segmented apertures. Certain embodiments of the present invention can improve aberration reduction by iterations. The iterative process alleviates convergence problem encountered by conventional techniques. Some embodiments of the present invention can simplify hardware requirements for aberration reduction, such as hardware requirements for coarse alignments of large telescopes. Certain embodiments of the present invention do not use the Pseudo-Hartmann mask, which is often used by conventional techniques for coarse figuring. Conventional techniques for coarse figuring often require two Pseudo-Hartmann masks, each of which is made up of sets of several multi-faceted prisms. Fabrication of the masks is difficult, time consuming and costly. Therefore, certain embodiments of the present invention can lower the cost and shorten the preparation time for aberration reduction. Some embodiments of the present invention usually can be implemented with minimum computation time.
It is understood the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. | System and method for estimating and correcting an aberration of an optical system. The method includes capturing a first plurality of images on a first plurality of planes. The first plurality of images is formed by at least the optical system. Additionally, the method includes processing at least information associated with the first plurality of images, and determining a first auxiliary function based upon at least the information associated with the first plurality of images. The first auxiliary function represents a first aberration of the optical system. Moreover, the method includes adjusting the optical system based upon at least information associated with the first auxiliary function. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary manual controller for use with a game machine for playing a competitive game with simulated racing cars, for example, to reflect a game player's rotary control action in the development of the competitive game played on the game machine.
2. Description of the Related Art
One conventional input device for use with game machines, for example, is a steering-wheel-type rotary manual controller including a steering wheel rotatable with a shaft. The game player turns the steering wheel in one direction or the other to enter control actions for playing the game on the game machine. The input device is usually combined with a game machine for playing a competitive game with simulated racing cars, for example.
The steering-wheel-type rotary manual controller comprises, in addition to the steering wheel mounted on one end of the shaft, a bearing by which the shaft is rotatably supported and a detector attached to the other end of the shaft for detecting an angular displacement of the steering wheel. While seeing the game as it proceeds on a display screen of the game machine, the game player turns the steering wheel through a desired angle in one direction. The angular displacement of the steering wheel is transmitted through the shaft and detected by the detector, and a signal generated by the detector is transmitted to an electronic control system in the game machine. Based on the signal supplied to the electronic control system, the electronic control system controls the game displayed on the display screen, e.g., moves a displayed game character in a corresponding direction in the displayed game.
With the conventional input device, the shaft which supports the steering wheel is freely rotatably supported by the bearing, and does not allow the game player to perceive physically the angle through which the steering wheel has been turned so far. The absence of a physical indication of the angular displacement of the steering wheel may possibly distract the game player's interest from the game.
One solution is to fit a helical spring over the shaft or connect an end of a helical spring to an arm projecting radially outwardly from the shaft, the helical spring being adjusted to exert no forces to the steering wheel when the steering wheel is in its neutral position. When the steering wheel is turned from the neutral position in one direction or the other, the helical spring exerts forces to the steering wheel for thereby resisting the turning of the steering wheel. Therefore, the game player who is gripping the steering wheel can sense the resistive forces applied from the helical spring to the steering wheel, and hence can physically perceive how much the steering wheel has been turned so far. Consequently, the game player is able to manipulate the steering wheel finely at well and become more interested in playing the game.
When the game player turns the steering wheel in one direction or the other, the resistive forces applied from the helical spring to the steering wheel increase or decrease progressively depending on the angular displacement of the steering wheel. With the progressively increasing or decreasing resistive forces, the game player finds it difficult to accurately spot the neutral position of the steering wheel.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a rotary manual controller for use with a game machine, which is of a relatively simple structure capable of allowing the game player to physically perceive how much a manual rotary control member has been turned, and also allowing the game player to recognize when the rotary input device reaches a neutral position thereof, based on a click-like tactile sensation.
According to the present invention, a rotary manual controller for use with a game machine includes a casing, a shaft rotatably mounted in the casing for rotation about its own axis, a manual control member angularly movable with the shaft between a neutral position and a manipulated position, for reflecting a game player's rotary control action in the development of a game played on the game machine, a biased member concentrically fixedly mounted on the shaft, abutment means movably supported in the casing for movement in contact with the biased member, and biasing means coupled to the abutment means for biasing the abutment means into contact with the biased member, the biased member and the abutment means being held in contact with each other through a surface area shaped to develop a click-like tactile sensation for the game player through the manual control member when the manual control member is angularly moved between the neutral position and the manipulated position.
When the manual control member is manually turned by the game player, the shaft is turned about its own axis, causing the biased member to turn with the shaft while under biasing forces from the biasing means. Since the biased member and the abutment means are held in contact with each other through the surface area shaped to develop a click-like tactile sensation for the game player through the manual control member when the manual control member is angularly moved between the neutral position and the manipulated position, the game player can physically perceive whether the manual control member is in the neutral position or the manipulated position. Based on the physical perception, the game player can manipulate the manual control means precisely for the development of the game, and hence can find the game interesting.
The biased member comprises a cam having a cam surface, and the surface area comprises an arcuate surface of the cam surface which is convex radially outwardly and extends between spaced corners thereof, the arcuate surface being held in slidable contact with the abutment means.
When the manual control member is turned to turn the shaft from the neutral position until the abutment means is contacted by one of the corners, the abutment means is angularly displaced largely against the bias of the biasing means. The biasing forces applied from the biasing means to the manual control member are sharply increased, and the game player physically recognizes that the manual control member is displaced from the neutral position to the manipulated position based on the increase in the biasing forces, i.e., a click-like tactile sensation. When the manual control member is returned to return the shaft to the neutral position, the biasing forces applied from the biasing means to the manual control member are sharply reduced. As a result, the game player physically recognizes that the manual control member is displaced back to the neutral position from the manipulated position based on the reduction in the biasing forces, i.e., a click-like tactile sensation.
Since the cam is used to impart the biasing forces from the biasing means to the manual control member and also to develop a click-like tactile sensation, the rotary manual controller is relatively simple in structure, is made up of a relatively small number of parts, can be assembled through a relatively small number of steps, and can be manufactured relatively inexpensively.
Each of the corners comprises an angular corner. Inasmuch as the corners are angular corners, when the manual control member is turned to turn the shaft until the abutment means is contacted by one of the corners, the abutment means is angularly displaced largely by the angular corner. The game player now feels a sudden change in the biasing forces transmitted from the biasing means to the manual control member, and is given a distinct click-like tactile sensation through the manual control member.
The arcuate surface has an angular extent about the axis of the shaft equally on both sides of a spot which is substantially central on the cam surface transversely across the shaft and is held in contact with the abutment means when the manual control member is positioned in the neutral position.
As long as the manual control member is turned in a neutral range, the abutment means remains in contact with the arcuate surface through the angular extent. During this time, the manual control member is in an idling range in which it is subject to no biasing forces from the biasing means. In the idling range, the manual control member can be turned with light forces, allowing the game player to recognize that the manual control member is in the idling range. When the manual control member is turned out of the idling range, the biasing forces transmitted from the biasing means to the manual control member increase greatly as the abutment means is displaced largely by one of the corners of the cam. Consequently, the game player can recognize that the manual control member is turned out of the idling range based on a distinct click-like tactile sensation.
The cam surface includes a pair of flat surfaces extending tangentially from respective ends of the arcuate surface away from each other to the corners, respectively, of the cam surface. The cam surface further comprises a pair of side arcuate facets extending from respective ends of the arcuate surface away from each other, and flat facets extending from respective side arcuate facets to the corners, the side arcuate facets and the flat facets jointly providing recesses in the cam.
With this cam surface profile, the game player is allowed to recognize that the manual control member is turned into and out of the idling range based on a distinct click-like tactile sensation.
The abutment means comprises a pair of abutment members spaced from each other and disposed one on each side of the biased member, the biased member comprising a cam having a pair of cam surfaces, the surface area comprising respective arcuate surfaces of the cam surfaces which are convex radially outwardly and extend between spaced corners thereof, the arcuate surfaces being held in slidable contact with the abutment members, respectively.
Because the cam is sandwiched between the abutment members, forces imposed on the shaft by the abutment members cancel each other, and hence the shaft is free of localized forces perpendicular thereto. As a result, any bearing by which the shaft is supported can be simplified in structure.
Each of the abutment members extends transversely across the shaft and is longer than the cam surfaces, the abutment members being angularly movably supported at ends thereof for pivotal movement about pivot shafts parallel to the shaft, the biasing means comprising a helical spring coupled to and disposed between opposite ends of the abutment members.
With the above structure, insofar as the manual control member is turned the same angle clockwise and counterclockwise, the helical spring imposes the same biasing forces to the manual control member irrespective of whether the manual control member is turned either clockwise or counterclockwise.
The abutment members have respective straight surfaces held in slidable contact with the cam surfaces, respectively.
The straight surfaces of the abutment members are held in slidable contact with the arcuate surfaces of the cam surfaces when the manual control member is in the neutral position. As long as the straight surfaces of the abutment members are held in slidable contact with the arcuate surfaces of the cam surfaces, the biasing forces applied from the biasing means are not changed greatly, and the game player does not develop a click-like tactile sensation through the manual control member. Consequently, the manual control member can be operated idly insofar as the straight surfaces of the abutment members are held in slidable contact with the arcuate surfaces. The game player can feel highly realistic about the manner in which the manual control member, which is preferably a steering wheel, is operated idly, and thus finds the game interesting.
The rotary manual controller further comprises restricting means for restricting angular movement of the shaft. The restricting means comprises a stop lever fixedly mounted on the shaft and a stop lever engaging base mounted in the casing for engaging the stop lever.
Inasmuch as the restricting means restricts angular movement of the shaft, the game player is prevented from turning the manual control member excessively beyond a certain effective angular range, and also from damaging the rotary manual controller.
The above and other objects, features, and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly broken away, of a rotary manual controller according to the present invention;
FIG. 2 is a perspective view, partly broken away, showing an internal structure of the rotary manual controller shown in FIG. 1;
FIG. 3 is a cross-sectional view taken along line III--III of FIG. 1;
FIG. 4 is a cross-sectional view taken along line IV--IV of FIG. 1;
FIG. 5 is a perspective view of the rotary manual controller shown in FIG. 2, showing the position of the parts when a steering wheel of the rotary manual controller is turned clockwise;
FIG. 6 is a perspective view of the rotary manual controller shown in FIG. 2, showing the position of the parts when a steering wheel of the rotary manual controller is turned counterclockwise;
FIG. 7A is a front elevational view of a biasing mechanism of the rotary manual controller, showing a cam as it is in a neutral position;
FIG. 7B is a front elevational view of the biasing mechanism of the rotary manual controller, showing the cam as it is turned clockwise from the neutral position against the bias of a helical spring;
FIG. 7C is a front elevational view of the biasing mechanism of the rotary manual controller, showing the cam as it is turned counterclockwise from the neutral position against the bias of the helical spring;
FIG. 8 is a front elevational view of a biasing mechanism having a cam according to another embodiment of the present invention; and
FIG. 9 is a front elevational view of a biasing mechanism having a cam according to still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a rotary manual controller according to the present invention, which is used as an input device 1 for use with a game machine for playing a competitive game with simulated racing cars, for example. In FIGS. 1 and 2, the directions -X, +X are referred to as transverse directions, whereas the directions -Y, +Y are referred to as longitudinal directions. Particularly, the direction -X refers to a forward or front direction, the direction +X a rearward or rear direction, the direction -Y a leftward or left direction, and the direction +Y a rightward or right direction.
As shown in FIGS. 1 and 2, the input device 1 generally comprises a casing 2 disposed in a game machine housing 11 and mounted on a rear surface of a front panel 12 of the game machine housing 11 which faces the game player, a rotatable shaft 3 extending longitudinally through the casing 2, a steering wheel or manual control member 4 fixedly mounted on a front end of the shaft 3 projecting forwardly from the front panel 12, a biasing mechanism 5 disposed in the casing 2 for applying biasing forces to the steering wheel 4 as it is turned by the game player, a restricting mechanism 6 for restricting the angular movement of the shaft 3, and a detecting mechanism 7 for detecting how much the steering wheel 4 is turned, i.e., an angular displacement of the shaft 3 about its own axis.
The casing 2 is in the form of an upwardly open box which comprises a bottom plate 21, a front plate 22 extending upwardly from a front edge of the bottom plate 21, a pair of transversely spaced side plates 23 extending upwardly from transversely spaced side edges of the bottom late 21, and a rear plate 24 extending transversely between respective rear edges of the side plates 23. The front plate 22 has a circular through hole 22a defined therein through which the shaft 3 extends. The rear edges of the side plates 23 are slanted such that the side plates 23 have their longitudinal dimension progressively greater in the upward direction. Therefore, each of the side plates 23 is of an inverted trapezoidal shape.
A vertical partition plate 25 extends upwardly from the rear edge of the bottom plate 21 and is connected between the side plates 23. The space in the casing 2 is divided by the partition plate 25 into a front chamber 26 defined in front of the partition plate 25 and housing the biasing mechanism 5 and the restricting mechanism 6 therein, and a rear chamber 27 defined behind the partition plate 25 and housing a portion of the detecting mechanism 7.
As shown in FIGS. 2 and 3, a vertical bearing plate 28 disposed in a front region of the front chamber 26 behind the front plate 22 and is connected between the side plates 23. The bearing plate 28 has a support hole 28a defined therein. A front bearing 13a is mounted on a rear surface of the bearing plate 28 coaxially with the circular support hole 28a and has a front end fitted in the circular support hole 28a. A rear bearing 13b is mounted on a front surface of the partition plate 25 coaxially with the front bearing 13a. The shaft 3 is rotatably supported by the front and rear bearings 13a, 13b for rotation about its own axis. The front end of the shaft 3 projects out of the casing 2 through the through hole 22a in the front plate 22. The steering wheel 4 is supported on a support tube 31 fitted over the projecting front end of the shaft 3 and secured thereto by a setscrew or the like.
The steering wheel 4 comprises an annular rim 41 which will be gripped by the game player, a T-shaped rim support spoke structure 42 integral with and positioned within the annular rim 41, and a holder disk 43 fixed to a central area of the rim support spoke structure 42. The rim support spoke structure 42 includes a plurality of bars or arms 42a having respective radially outer ends fixed to the annular rim 41, so that the annular rim 41 and the rim support spoke structure 42 are concentrically integral with other.
The rim support spoke structure 42 has a plurality of through holes defined at equally spaced intervals in an annular pattern in a central region thereof, and the holder disk 43 also has a plurality of through holes defined at equally spaced intervals in an annular pattern therein. Screws are inserted through these through holes in the rim support spoke structure 42 and the holder disk 43 and threaded into respective threaded holes defined in a front end of the support tube 31. The rim support spoke structure 42 and the holder disk 43 are thus fastened to the support tube 31, with the rim support spoke structure 42 being sandwiched between the holder disk 43 and the support tube 31. When the annular rim 41 is manually turned about its own axis by the game player, the shaft 3 is turned about its own axis with the steering wheel 4.
As shown in FIGS. 2 and 4, the biasing mechanism 5 comprises a cross-sectionally U-shaped pivot member 51 vertically mounted on the right end of a longitudinally central area of the bottom plate 21, a pair of vertically spaced, upper and lower transverse abutment members 52 pivotally supported at respective right ends thereof on respective upper and lower portions of the pivot member 51, a helical spring 53 joined vertically between right ends of the abutment members 52, and a cam 54 mounted concentrically on the shaft 3 between the abutment members 52 and having upper and lower cam surfaces slidably engaging respective flat straight surfaces of the abutment members 52, respectively. The upper and lower transverse abutment members 52 extend transversely across the shaft 3 and are longer than the cam 54.
The pivot member 51 comprises a vertical back plate 51a and a pair of front and rear pivot plates 51b bent at a right angle from respective front and rear edges of the back plate 51a to the left. The back plate 51a is fastened to an inner surface of a right one of the side plates 23 by screws. The right ends of the abutment members 52 fitted between the pivot plates 51b. Pivot shafts 51c extend through the pivot plates 51b and the abutment members 52 parallel to the shaft 3 and have opposite ends staked to keep the abutment members 52 pivotally supported on the pivot member 51 for angular movement about the pivot shafts 51c.
The cam 54 is of a partly elliptical, elongate rectangular shape as viewed in front elevation, i.e., along the shaft 3. The cam 54 has a through hole 54a defined centrally therein through which the shaft 3 extends and a slot 54b defined in an inner circumferential surface of the through hole 54a and extending along the shaft 3. The shaft 3 has an axial tooth 32 projecting from an outer circumferential surface thereof and fitted in the slot 54b in the cam 54. The tooth 32 has opposite ends staked on the cam 54. The cam 54 is thus fixedly mounted on the shaft 3 for rotation with the shaft 3.
The upper and lower cam surfaces of the cam 54 include respective upper and lower arcuate surfaces 54c which are convex radially outwardly. When the steering wheel 4 is in its neutral position, the upper and lower abutment members 52 engage the upper and lower arcuate surfaces 54c, respectively, while holding the cam 54 therebetween. At this time, the upper and lower abutment members 52 extend substantially parallel to each other.
When the steering wheel 4 is manually turned clockwise by the game player, the cam 54 is also turned clockwise, causing its upper left and lower right angular corners thereof to turn the upper and lower abutment members 52 away from each other about the respective pivot shafts 51c against the bias of the helical spring 53. Specifically, the upper left angular corner of the cam 54 angularly lifts the upper abutment member 52, and the lower right angular corner of the cam 54 angularly lowers the lower abutment member 52. At this time, biasing forces produced by the helical spring 53 depending on the angular displacement of the shaft 3 and hence the cam 54 are transmitted through the upper and lower abutment members 52, the cam 54, and the shaft 3 to the steering wheel 4.
Conversely, when the steering wheel 4 is manually turned counterclockwise by the game player, the cam 54 is also turned counterclockwise, causing its upper right and lower left angular corners thereof to turn the upper and lower abutment members 52 away from each other about the respective pivot shafts 51c against the bias of the helical spring 53. Specifically, the upper right angular corner of the cam 54 angularly lifts the upper abutment member 52, and the lower left angular corner of the cam 54 angularly lowers the lower abutment member 52. Biasing forces produced by the helical spring 53 are transmitted through the upper and lower abutment members 52, the cam 54, and the shaft 3 to the steering wheel 4. Since the cam 54 is sandwiched between the upper and lower abutment members 52 that are resiliently interconnected by the helical spring 53, when the steering wheel 4 is turned clockwise and counterclockwise through the same angle, the helical spring 53 exerts the same biasing forces to the steering wheel 4.
The restricting mechanism 6 comprises a stop lever 61 fixedly mounted on the shaft 3 and a stop lever engaging base 62 for engaging the stop lever 61. The stop lever 61 is in the form of a transversely elongate thick plate that is symmetrically in shape with respect to its center, and positioned on the shaft 3 slightly in front of the cam 54. The stop lever 61 has a through hole 61a defined centrally therein through which the shaft 3 extends and a slot 61b defined in an inner circumferential surface of the through hole 61a and extending along the shaft 3. The shaft 3 has an axial tooth 33 projecting from an outer circumferential surface thereof and fitted in the slot 61b in the stop lever 61. The tooth 33 has opposite ends staked on the stop lever 61. The stop lever 61 is thus fixedly mounted on the shaft 3 for rotation with the shaft 3.
The stop lever engaging base 62 comprises a cross-sectionally U-shaped channel 63 bent from a metal sheet and a stop lever engaging plate 64 fixedly mounted on the channel 63. The channel 63 has a pair of legs secured to the bottom plate 21, and extends transversely below the stop lever 61. The stop lever engaging plate 64 is fastened to an upper flat plate of the channel 63 by screws.
The stop lever engaging plate 64 has an upper surface slightly spaced downwardly from the stop lever 61 when the stop lever 61 lies horizontally. When the steering wheel 4 and hence the shaft 3 are turned in one direction or the other, the stop lever 61 is turned with the shaft 3, bringing a left or right end thereof into contact with the upper surface of the stop lever engaging plate 64 thereby to stop the angular displacement of the steering wheel 4 and hence the shaft 3. Therefore, the stop lever 61 cooperates with the stop lever engaging plate 64 in defining an angular range in which the shaft 3, i.e., the steering wheel 4, can be turned.
The detecting mechanism 7 comprises a large gear 71 fixedly mounted concentrically on the shaft 3 behind the cam 54, a small gear 72 mounted for corotation on a shaft 72a rotatably mounted longitudinally on the partition plate 25 and held in mesh with the large gear 71, and a rotary encoder 73 coupled to a rear end of the shaft 72a within the rear chamber 27 for detecting an angular displacement of the shaft 3 about its own axis.
Angular displacement of the shaft 3 caused by the steering wheel 4 is transmitted through the large gear 71, the small gear 72, and the shaft 72a to the rotary encoder 73. The rotary encoder 73 detects the number of revolutions of the shaft 72a for thereby detecting the angular displacement of the shaft 3 about its own axis, i.e., how much the steering wheel 4 has been turned. A signal from the rotary encoder 73, representative of how much the steering wheel 4 has been turned, is supplied to a control system (not shown) in the game machine housing 11 and used in a process of controlling the game played on the game machine.
FIG. 5 shows the position of the parts of the input device 1 when the steering wheel 4 is turned clockwise, and FIG. 6 shows the position of the parts of the input device 1 when the steering wheel 4 is turned counterclockwise. When the game player grips the rim 41 of the steering wheel 4 and turns it clockwise as shown in FIG. 5, the rotation of the rim 41 is transmitted through the rim support spoke structure 42, the holder disk 43, and the support tube 31 to the shaft 3, which is also turned clockwise about its own axis.
The cam 54 integral with the shaft 3 is also turned clockwise, causing the upper left angular corner of the cam 54 to engage and lift the upper abutment member 52 and the lower right angular corner of the cam 54 to engage and lower the lower abutment member 52. Therefore, the upper and lower abutment members 52 are turned away from each other about their respective pivot shafts 51c. The movement of the upper and lower abutment members 52 away from each other extends the helical spring 53 joined to the left ends of the upper and lower abutment members 52, increasing the biasing forces produced by the helical spring 53 depending on the angular displacement of the steering wheel 4. Since the increased biasing forces from the helical spring 53 are transmitted to the steering wheel 4, the game player physically recognizes the angular displacement of the steering wheel 4, i.e., how much the steering wheel 4 is turned.
When the game player turns the steering wheel 4 fully through its angular range to a clockwise allowable maximum position, the right end of the stop lever 61 engages the stop lever engaging plate 64, preventing the steering wheel 4 to be turned further clockwise.
When the game player turns the rim 41 counterclockwise as shown in FIG. 6, the upper right angular corner of the cam 54 engages and lifts the upper abutment member 52 and the lower left angular corner of the cam 54 engages and lowers the lower abutment member 52. Therefore, the helical spring 53 is extended, increasing the biasing forces produced by the helical spring 53. The increased biasing forces are transmitted from the helical spring 53 to the steering wheel 4, whereupon, the game player physically recognizes the angular displacement of the steering wheel 4. When the game player turns the steering wheel 4 fully through its angular range to a counterclockwise allowable maximum position, the left end of the stop lever 61 engages the stop lever engaging plate 64, preventing the steering wheel 4 to be turned further counterclockwise.
FIGS. 7A through 7C show the relationship between the positional changes of the abutment members 52 and the biasing forces of the helical spring 53. Specifically, FIG. 7A shows the cam 54 as it is in its neutral position, FIG. 7B shows the cam 54 as it is turned clockwise from the neutral position against the bias of the helical spring 53, and FIG. 7C shows the cam 54 as it is turned counterclockwise from the neutral position against the bias of the helical spring 53.
When the steering wheel 4 is held in the neutral position, as shown in FIG. 7A, the cam 54 is also held in the neutral position in which the cam 54 is horizontally symmetrical with respect to a dot-and-dash vertical line L passing through the axis of the shaft 3. The upper and lower arcuate surfaces 54c of the cam 54 have respective transversely central spots 540c kept in contact with the respective upper and lower abutment members 52 that are being urged toward each other under the bias of the helical spring 53.
Insofar as the game player turns the rim 41 in one direction or the other within a neutral range or idling range where the upper and lower arcuate surfaces 54c of the cam 54 are held in contact with the respective upper and lower abutment members 52, as indicated by the two-dot-and-dash lines in FIG. 7A, the upper and lower abutment members 52 are slightly turned about the respective pivot shafts 51c, slightly increasing the biasing forces produced by the helical spring 53. However, since the upper and lower arcuate surfaces 54c of the cam 54 remain in contact with the respective upper and lower abutment members 52, the increased biasing forces produced by the helical spring 53 and applied to the steering wheel 4 are not large compared with the angular displacement of the steering wheel 4. In this neutral range, the game player 4 can turn the steering wheel 4 with light forces, and can recognize that the steering wheel 4 is in the neutral range or idling range.
When the game player turns the steering wheel 4 clockwise beyond the neutral range, as shown in FIG. 7B, the upper left angular corner, denoted by 541c, of the cam 54 engages and lifts the upper abutment member 52 and the lower right angular corner, denoted by 542c, of the cam 54 engages and lowers the lower abutment member 52. The upper abutment member 52 is lifted a distance much greater than the distance by which it was lifted when the steering wheel 4 was turned in the neutral range as shown in FIG. 7A, and similarly the lower abutment member 52 is lifted a distance much greater than the distance by which it was lowered when the steering wheel 4 was turned in the neutral range as shown in FIG. 7A. Accordingly, when the steering wheel 4 is turned beyond its neutral range, the biasing forces applied from the helical spring 53 to the steering wheel 4 are increased greatly, enabling the game player to physically perceive that the steering wheel 4 has been turned beyond its neutral range or idling range.
When the game player turns the steering wheel 4 counterclockwise beyond the steering range, as shown in FIG. 7C, the upper right angular corner, denoted by 543c, of the cam 54 engages and lifts the upper abutment member 52 and the lower right angular corner, denoted by 544c, of the cam 54 engages and lowers the lower abutment member 52. At this time, the biasing forces applied from the helical spring 53 to the steering wheel 4 are also increased greatly, enabling the game player to physically perceive that the steering wheel 4 has been turned beyond its neutral range or idling range.
Since the cam 54 is always sandwiched between the upper and lower abutment members 52, the moment which is imposed on the cam 54 by the helical spring 53 while the upper left angular corner 541c of the cam 54 is engaging the upper abutment member 52 and the lower right angular corner 542c of the cam 54 is engaging the lower abutment member 52 upon clockwise movement of the steering wheel 4, and the moment which is imposed on the cam 54 by the helical spring 53 while the upper right angular corner 543c of the cam 54 is engaging the upper abutment member 52 and the lower right angular corner 544c of the cam 54 is engaging the lower abutment member 52 upon counterclockwise movement of the steering wheel 4 are equal to each other insofar as the steering wheel 4 is turned clockwise and counterclockwise through the same angle. Consequently, the steering wheel 4 is subject to the same biasing forces from the helical spring 53 regardless of the direction in which the steering wheel 4 is turned.
FIG. 8 shows a biasing mechanism having a cam 55 according to another embodiment of the present invention. Those parts of the biasing mechanism shown in FIG. 8 which are identical to the biasing mechanism 5 shown FIGS. 1 through 7A-7C are denoted by identical reference characters, and will not be described in detail below.
As shown in FIG. 8, the cam 55 has, on each of its upper and lower cam surfaces, a central arcuate surface 55a extending about the axis O of the shaft 3 and a pair of flat straight surfaces 55b extending tangentially from respective ends 551a of the central arcuate surface 55a away from each other to respective outer angular corners 55c of the cam surface. With the steering angle 4 in the neutral position, a straight line extending from the axis O of the shaft 3 to one of the ends 551a of the central arcuate surface 55a is angularly spaced an angle α from the vertical line L passing through the axis O of the shaft 3, and a straight line extending from the axis O of the shaft 3 to the other one of the ends 551a of the central arcuate surface 55a is also angularly spaced the same angle α from the vertical line L passing through the axis O of the shaft 3. Therefore, even when the steering wheel 4 is turned within the angle α either clockwise or counterclockwise from the neutral position, the distance between the upper and lower abutment members 52 remains unchanged. Accordingly, insofar as the steering wheel 4 is turned within the angle α either clockwise or counterclockwise from the neutral position, the steering wheel 4 is idling with no biasing forces applied thereto from the helical spring 53.
When the steering wheel 4 is turned the angle α either clockwise or counterclockwise from the neutral position, the flat surfaces 55b, one on each of the upper and lower cam surfaces, are brought into contact with the upper and lower abutment members 52. Further turning of the steering wheel 4 causes the corresponding angular corners 55c, which are symmetric with respect to the axis O of the shaft 3, to spread the upper and lower abutment members 52 away from each other against the bias of the helical spring 53. The biasing forces from the helical spring 53 are now increased and applied to the steering wheel 4. Therefore, the game player can physically recognize the angular displacement of the steering wheel 4 beyond the angle α based on a click-like tactile sensation imparted by a sudden increase in the biasing forces from the helical spring 53.
When the steering wheel 4 is returned from an angular displacement beyond the angle α back to the idling angular displacement within the angle α, since the biasing forces applied to the steering wheel 4 by the helical spring 53 are suddenly eliminated. Consequently, the game player can also physically recognize the return of the steering wheel 4 to the idling angular displacement within the angle α based on a click-like tactile sensation imparted by a sudden elimination of the biasing forces from the helical spring 53.
The arcuate surfaces 55a on the upper and lower cam surfaces of the cam 55, each angularly extending the angle α-7C are denoted by identical reference characters, and will not be described in detail below.
The cam 56 shown in FIG. 9 is similar to the cam 55 shown in FIG. 8 except that the cam 56 has, on each of its upper and lower cam surfaces, an arcuate surface 56a extending about the axis O of the shaft 3, and the arcuate surface 56a comprises a central arcuate surface 561a and a pair of side arcuate facets 562a extending from the central arcuate surface 561a away from each other. With the steering angle 4 in the neutral position, a straight line extending from the axis O of the shaft 3 to one of the ends of the central arcuate surface 561a is angularly spaced an angle α from the vertical line L passing through the axis O of the shaft 3, and a straight line extending from the axis O of the shaft 3 to the other one of the ends of the central arcuate surface 561a is also angularly spaced the same angle α from the vertical line L passing through the axis O of the shaft 3. Each of the upper and lower cam surfaces of the cam 56 has outer angular corners 56b that are positioned on imaginary straight lines L1 which extend tangentially to boundary points 561b between the central arcuate surface 561a and the side arcuate facets 562a. The side arcuate facets 562a and flat straight facets extending from their ends to the outer angular corners 56b provide recesses in the upper and lower cam surfaces of the cam 56 within the tangential lines L1.
The cam 56 shown in FIG. 9 offers the same advantages as the cam 55 shown in FIG. 8. In addition, since the recesses are defined in the upper and lower cam surfaces of the cam 56 within the tangential lines L1, the material of the cam 56 may be smaller in quantity than the material of the cam 55, and hence the cost of the cam 56 may be smaller than the cost of the cam 55.
In each of the above embodiments, the biasing mechanism has a pair of upper and lower abutment members 52. However, the biasing mechanism may have a pair of transversely spaced abutment members or a pair of diagonally spaced abutment members with the cam being oriented correspondingly. Furthermore, the biasing mechanism may have a single abutment member. If the biasing mechanism has a single abutment member, then since the moment applied to the cam 54 under the bias of the helical spring 53 differs depending on the direction in which the steering wheel 4 is turned, the abutment member should preferably be kept horizontal and translatable toward and away from the shaft 3, rather than being pivotable about the pivot shaft 51c.
In the embodiment shown in FIGS. 1 through 7A-7C, the cam 54 has the upper and lower arcuate surfaces 54c to provide the neutral range or idling range for the steering wheel 4. Instead of the upper and lower arcuate surfaces 54c on the cam 54, each of the upper and lower abutment members 52 may have an arcuate surface facing the cam 54.
In the above embodiments, the manual control member comprises the steering wheel 4. However, the manual control member may be a manual control rod, for example.
In the embodiment shown in FIGS. 1 through 7A-7C, the cam 54 has the upper and lower arcuate surfaces 54c which are convex radially outwardly. However, if a distinct click-like tactile sensation is to be developed for the game player when the steering wheel 4 reaches the neutral position, then the cam 54 may have flat surfaces or radially inwardly concave surfaces rather than the upper and lower arcuate surfaces 54c. With such flat surfaces or radially inwardly concave surfaces on the cam 54, when the steering wheel 4 reaches the neutral position, the abutment members 52 are brought into substantially face-to-face contact with the cam 54. Because no idling range is available for the steering wheel 4, the game player can have a distinct click-like tactile sensation when the steering wheel 4 reaches the neutral position.
In the above embodiments, each of the cams 54, 55, 56 is horizontally symmetrical with respect to its center. However, the cam of the biasing mechanism is not limited to a horizontally symmetrical shape, but may be of a horizontally asymmetrical shape.
Although certain preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications may be made therein without departing from the scope of the appended claims. | A rotary manual controller for use with a game machine has a steering wheel manually operable by the game player to rotate a shaft in one direction or the other between a neutral position and a manipulated position, for entering information about a game player's rotary control action to develop a game played on the game machine. The rotary manual controller includes a biasing mechanism for biasing the shaft to return to the neutral position, and a restricting mechanism for restricting angular movement of the shaft. The biasing mechanism has a cam of a partly elliptical, elongate rectangular shape concentrically mounted on the shaft, a pair of abutment members extending transversely across the shaft and held in slidable contact with respective cam surfaces of the cam, and a helical spring for biasing the abutment members into slidable contact with respective cam surfaces of the cam. | 0 |
This application is a file wrapper continuation of application Ser. No. 07/885,578, filed May 19, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns a disk file storage apparatus of the type in which one or more rigid disks are provided for storage of data which is written to, or read from, the disks by transducers ("heads") while the disks spin. In particular, the invention concerns the measurement of spacing between the transducer mechanisms and the disks.
2. Description of the Prior Art
Data storage on rigid disks is covered extensively in Volume II of the reference work entitled MAGNETIC RECORDING, Mee, et al, eds., McGraw-Hill, 1988. In Chapter 2 of this work, a rigid disk file is described as "a stack of rigid disks" which are rotated at a high speed and whose surfaces are written to or read from using arm-mounted heads which are suspended and positioned by an actuator assembly over the surfaces. The heads are supported against disk surfaces by a thin cushion of air generated by rotation of the disks.
A disk file servo processor controls the radial position of heads with respect to disks so that selected circumferential tracks on a disk surface can be read or written to. A data channel is provided for each head. Data is recovered in a data channel by peak detection means, while head drive circuitry is provided to write data to a disk surface.
The amount of data which can be recorded on a disk (the "density" of data) is a primary indication of how well a disk file operates. One significant limitation on data density is the "spacing loss" which corresponds essentially to the distance between the head and the magnetic recording surface of a disk. Relatedly, the smaller the spacing between a head and a disk, the higher the potential data density. Variation of the distance during rotation of the disk will cause a corresponding variation in data density. Therefore, disk file manufacturing requires not only head suspension mechanisms which will stablely position a head close to a disk, but also disk whose surfaces are as flat and as defect-free as possible.
Therefore, one of the critical control evaluations made during manufacture of disk file components and assembly of disk file mechanisms is the measurement of head/disk spacing. U.S. Pat. No. 4,777,544 of Brown et al, commonly assigned with this application, well describes a method and a means for measurement of head/disk spacing. The '544 patent lays out a harmonic ratio fly height (HRF) technique for calculating head/disk spacing measurement by comparing readback spectral amplitude ratios obtained by reading a previously-recorded clearance measurement signal track at nominal and zero "flying heights".
The means of the '544 patent for taking the nominal and zero height measurements are analog components, which are impractical to integrate into a disk file mechanism because of cost, size, and performance considerations. Further, the '544 patent is directed essentially to measurement of an average flying height and makes no provision for obtaining the profile of a circumferential disk track in the form of a plurality of flying height measurements at discrete points along the track.
SUMMARY OF THE INVENTION
It is, therefore, the principal object of this invention to set forth a method and apparatus for measuring head/disk clearance in a digital manner which provides a head/disk clearance profile over each track or a plurality of tracks on a disk surface.
The invention is practiced in a disk file which includes one or more rigid disks, means for rotating the rigid disks, one or more read/write heads, actuator means for moving the heads across respective surfaces of the disks, servo-processor means controlling the actuator means and the means for rotating, for radially positioning the heads with respect to respective surfaces, and for setting a speed at which disks rotate, and data channel means connected to the heads for reading signals from, and writing signals to, the disk surfaces. In this context, the invention is a combination for measuring the distance between a head and the surface of a disk, and includes:
a digital signal processor in the disk file which responds to a clearance control signal indicative of the speed of the disk by producing predetermined harmonics of a measurement signal read from the surface of the disk by the head;
a clearance test control mechanism in the disk file which:
positions the head with respect to a predetermined area of the surface where the measurement signal is located;
rotates the disk at predetermined speeds; and
generates the clearance signal;
a clearance test analysis mechanism in the disk file, connected to the digital signal processor, and responsive to the predetermined harmonics which produces clearance signals representing the flying height of the head with respect to the surface of the disk at each of a plurality of predetermined locations on a circumference of the surface of the disk; and
storage in the disk file and connected to the clearance test mechanism which stores spacing signals for a plurality of circumferences on the disk surface.
The invention provides the means in a disk file mechanism to maintain and selectively reference a head/disk clearance history which extends from the time that the disk file is manufactured and assembled. The invention supports the provision of a predictive failure analysis mechanism in the disk file which maintains and updates the profile history and which uses the history to anticipate and warn of impending failure caused by a head/disk "crash".
Another benefit provided by the invention is the ability to detect mechanical defects such as asperities on the surface of a disk through a technique known as "glide testing". In this testing procedure, performed using the components of the distance-measuring combination, peak values read from a measurement signal on the disk are compared to average values. If the difference between the peak and average values is greater than a predetermined threshold, the values are further analyzed for the presence of a "contact signature" corresponding to a disk asperity.
Accordingly, another objective of this invention is to provide a method and apparatus for detection of irregularities on the surface of a disk using the components of the head/disk spacing measurement method and means.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description of preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a disk file which incorporates the invention.
FIG. 2 is a plot showing head/disk clearance as a function of a sequence of discrete disk velocities.
FIGS. 3A and 3B are plots showing the signal amplitude of a section of a disk tract containing a clearance signal in which the signal is sampled at a given rate while the disk is spinning at full speed (FIG. 3A) and half speed (FIG. 3B).
FIG. 4 is a composite schematic diagram and waveform plot showing a head/disk clearance profile on a section of a track containing a clearance signal.
FIG. 5 is a schematic representation of a table maintained in disk file storage for containing the head/disk clearance profile history.
FIG. 6 is a schematic illustration of a digital mechanism in a disk file data channel according to the invention.
FIG. 7 is a flow diagram illustrating the steps for a disk/head clearance measurement.
FIG. 8 is a plot of measurements taken on a track containing a glide test signal showing a disk defect.
FIGS. 9 is a flow diagram illustrating a predictive failure analysis component of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention as described is applied to a disk file including rigid electro-magnetic disks. However, those skilled in the art will appreciate that the invention is not so limited, but may be applied to other mechanically moving magnetic storage apparatus, as well.
As the referenced '544 patent points out, the terms "head/disk clearance" and "flying height" are used interchangeably in the art. These terms are considered to be synonymous, and are freely substituted one for another in this description.
FIG. 1 illustrates a disk file assembly and includes a voice coil motor (VCM) assembly 10 with attached arms and suspensions 12, and heads 13. A spindle assembly includes a hub 14, rigid disks 15, and a spindle motor 16. The heads 13 "fly" on both top and bottom surfaces of the disks 15 as they read and/or write data on the magnetic material deposited on the surfaces of the disks. In this regard, a head "flies" over a disk surface supported by a bearing of air induced between the disk and the head in response to the high speed rotation of the disk.
The electro-magnetic transducer in a head is connected to a data channel, one of which is indicated by reference numeral 20. The read and write electronics portions of the data channel 20 are connected to an individual head by conventional means (not shown) such as a flex cable. As a disk rotates adjacent an individual head, a signal is read from a track on the surface of the disk by electro-magnetic detection in the head transducer and then is amplified using a preamplifier 22. The output of the preamplifier 22 is fed to data channel read electronics 24 which filter and equalize the amplified signal and which typically employ a peak detection procedure to detect data in the amplified, processed signal. The channel read electronics 24 may also include clocking circuits to extract a data clock.
The data channel 20 also includes write electronics 25 which may precondition a data signal to be laid down on a disk track. The write electronics provide the signal which is to be recorded to a write driver 26 that is conventionally connected to a head transducer for writing onto a disk track.
The disk file of FIG. 1 also contains processing components including a servo processor 30 and file microprocessor 40. Conventionally, the servo processor 30 may include an invokable application run on a separate microprocessor or on the file microprocessor 40. The servo processor 30 includes a spindle control program component 31 and a VCM actuator control program component program 32. The servo processor is provided to control the actuator assembly including the VCM 10 and arms and suspensions 12 to position the heads 13 at fixed radial locations over the surfaces of the disks 15. The positioning function of the actuator control program 32 is essentially conventional, employing servo signals written continuously onto disk surfaces or into dedicated servo sectors on the surfaces. These signals are read by the heads 13 and fed back to the servo processor 30 through read channel electronics 24 and a demodulator 27. The actuator program 32 functions to move an actuator to a desired position and to maintain the actuator in the desired position by reduction of position error. The actuator control program implements track following, track searching, head registration, and head parking functions which are well understood.
The file microprocessor 40 includes a data interface section 41 which performs interface functions including encoding and decoding of data to be written to and read from a disk, a host interface section 42 for providing control and data information to and receiving commands and data from a host computer, and a mode control section 43 for establishing and changing modes of microprocessor operation.
In the invention, a clearance and glide program 33 is provided as a component of the servo processor 30. This illustrates a preferred embodiment and best mode; however, the inventors contemplate that the clearance and glide program can be lodged according to design considerations in any of the microprocessor resources of a disk file. In addition, predictive failure analysis (PFA) components 34, 44, and 45 are provided in the invention. These programming components are explained in greater detail below.
The major interconnections between the components of the disk file illustrated in FIG. 1 include a data signal path 50 between the data interface 41 of the file microprocessor 40 and the read and write electronics 24 and 25 of the data channel 20. The command/data signal path 52 connects the disk file of FIG. 1 through its host interface 42 with a host computer (not shown). Demodulated servo signals are provided to the spindle control program 31 and actuator control program 32, respectively, from the demodulator 27 over signal paths 53 and 54. The signal path 55a conducts a servo control signal to the VCM 10. Signal path 55b conducts a motor speed control signal from the spindle control program 31 to the spindle motor 16. Signal paths 56, 57, and 58 are used in the invention. The signal path 56 connects the digital read channel electronics 24 with the clearance and glide program 33, conducts control signals to configure the read channel electronics 24 for testing according to the invention and also conducts clearance and glide signal components to the clearance and glide program 33 for analysis. The clearance and glide program is enabled by an appropriate control signal sequence on signal path 57 from the mode control 43. Clearance and glide program data is passed directly by conventional programming means to the predictive failure analysis (PFA) program element 34 in the servo processor 30 and from there on the signal path 58 to the a PFA component 44 and PFA storage 45 in the file microprocessor 40.
Upon receipt of a clearance and glide test command from either the host computer or as requested by the PFA program 34, the clearance and glide section 33 of the servo processor 30 takes control of the digital read channel electronics 24, the VCM control programming 32, and the spindle control program 31 in order to perform clearance and glide test measurements. Results from the clearance and glide test measurements are passed to the PFA program section 34 for preliminary failure analysis. The results of the preliminary analysis are provided to the PFA section 44 of the file microprocessor 40 which, according to the invention, stores results in PFA storage 45 for further trend analysis or calls for additional measurements using the mode control 43. If an imminent head crash or other head/disk interface problem condition is detected, the host computer is notified using the host interface section 42. Additionally, PFA data may be saved in an error log on one or more of the disk surfaces using the data interface section 41. The data interface section 41 is also used to retrieve previously saved clearance and glide test data to be analyzed by the PFA, should such data be stored on one or more of the disks 15.
HEAD/DISK CLEARANCE MEASUREMENTS
The invention overcomes the problem of not being able to determine, using in-situ disk file components, clearance between any head/disk pair in the disk file. The invention employs the theoretical basis of the HRF technique discussed at length in the '544 patent, using digital electronics and the processing capacity of the disk file to calculate head/disk clearance, and maintains historical files of such measurements for predictive failure analysis.
The HRF technique employs a measurement signal written on a disk track, and a multi-step "spin down" of the disk speed to derive a set of points from which a velocity versus clearance curve may be derived. The measurement signal laid down in a disk surface track has a constant spectrum which generates a readback signal including at least two different frequencies which are harmonics of the measurement signal. Preferably, the first and third harmonics are included in the readback signal. The clearance measurement procedure requires rotating the disk at operational speed, and determining the instantaneous amplitudes of the harmonic frequencies at that speed. The logarithm of the ratio of the amplitudes is indicative of head/disk clearance. The rotational velocity of the disk is then reduced while the instantaneous amplitude of the readback signal is monitored. As is known, reduction of the rotational speed of the disk from its operational speed decreases the pressure of the air cushion on the head, thereby reducing the head/disk clearance. As the velocity of the disk is decreased, the instantaneous amplitudes of the harmonics are determined until a velocity is reached where the amplitudes stop changing. When the amplitudes stop changing, the head is assumed to be in contact with the disk. At each measurement velocity between operational velocity and the contact velocity, the ratio of the instantaneous amplitudes of the two harmonics is calculated and numerical methods are employed to derive the flying height at each measurement velocity, using the zero clearance velocity as reference.
In FIG. 2, a head/disk clearance measurement procedure according to the HRF technique is shown graphically. In FIG. 2, the measurement procedure reverses the sequence described above and is essentially a "spin-up" procedure. The line segments 70 give the spindle velocity as a function of time. The amount of head/disk clearance, as determined by the HRF clearance measurement is given by the curve 80, which shows head/disk clearance as a function of spindle velocity. Clearance measurement begins at 73 which coincides with start-up of the spindle motor. For each vertical line segment 70 (such as the segment between the points 73 and 74), the spindle velocity is held constant and the necessary digital measurements to determine head/disk clearance are taken. For a particular head, the digital measurement for start-up corresponds to the point 85 on the clearance versus velocity curve 80. After all heads have been measured at start-up (which occurs at point 74), the spindle velocity is increased to point 76. Measurements for all heads are repeated at this velocity, and so on. The process continues for higher velocities until the measurements have been completed at the nominal operational velocity indicated at point 77. For the particular head given by the clearance curve 80, this point occurs at 88.
The measurement data for each head at each velocity can be processed dynamically or stored in an array for later processing. In either case, the clearance at any velocity is found by subtracting the minimal clearance measurement at point 89 from the clearance measurement at the respective velocity. For example, the nominal clearance at the operational velocity (point 88) is found by subtracting the clearance valve at point 89 from that at point 88. This determination is made for each head. The most direct approach to making this measurement is to assume a mathematical functional form for the continuous clearance curve 80 and then, based on the measurements taken at the discrete velocities, to establish a best fit for the chosen function. From this, the minimum clearance at 89 can be found. Following this step, the clearance for each head is then simply the difference between the digital measurements made at the nominal speed (point 88) and the minimal speed (point 89) scaled by the wavelength of the recorded clearance signal. The magnitude of the clearance is shown in FIG. 2 as the distance 90.
FIGS. 3A, 3B, and 4 illustrate how the invention employs spatial signal processing of the readback signal to make clearance measurements at a series of locations along a circumferential track on which a clearance measurement signal has been written. Of course, the relative dimensions and recorded signal formats are exaggerated or altered from those encountered in practice; however, the exaggerations are for clarity, and not for limitation. In FIG. 4, a high-frequency clearance measurement signal 92 is recorded in a circumferential track 94 of a disk 96. Assume that a head is positioned over the track 94. FIG. 3A represents the clearance measurement signal as one of constant periodicity and shows a portion of the signal in a minute section of the track 94. According to the invention, the signal is sampled at a given rate f s (samples per second), while the disk is spinning at operational speed. FIG. 3A illustrates a sampling rate providing eight samples per period of the recorded clearance measurement signal. Each sample is taken at a particular time and is represented on the waveform 92 by the points 100a-100h.
Next, assume that the rotational velocity of the disk is reduced to one-half of that represented by FIG. 3A and that the sampling rate f s is reduced to one-half of the sampling rate illustrated in FIG. 3A. The clearance measurement signal, with eight samples 101a-101h, is illustrated in FIG. 3B. Note that the samples of the signals in FIG. 3A and 3B occur at exactly the same points in the readback signal and correspond to identical locations in the track 94.
The implication of FIGS. 3A, 3B, and 4 is clear: if the sampling rate of the readback signal generated by a head in response to a clearance measurement signal on a particular track is related to the inverse of the measurement signal's period, the sampling procedure will generate a sequence of samples corresponding to a sequence of physical locations along the track. Another implication: if the sampling rate is changed directly with the rotational speed of the disk during spindown, sets of samples can be generated for each of the sequence of physical locations and the instantaneous flying height at each location can be calculated using a digital form of the HRF algorithm described above. Thus, a profile comprising an envelope connecting a sequence of discrete flying heights in each location of a sequence of locations along the track 94 can be generated by using the HRF measurement technique in combination with spatial sampling as described above. In FIG. 4, a portion of such an envelope is illustrated by connecting the tips of each of the vectors 104, where each vector is a link proportional to the instantaneous flying height calculated at the disk track location at which the vector is positioned.
Well-known digital techniques can be employed to obtain and process the samples and to calculate the flying heights in the manner discussed above, and a plurality of such profiles can be generated for each of a plurality of tracks on a disk surface. These profiles can be stored in tabular form as illustrated in FIG. 5 together with a profile sequence numbers ("PROFILE SN") significant of when a profile was taken. Thus, for example, at disk file assembly, tracks 1-n would each have a profile taken, each profile being given the sequence number 1. Next, at some later time after the disk file is placed in operation, another set of profiles for tracks 1-n can be taken and given profile sequence numbers 2, and so on.
FIG. 6 illustrates, in block diagram form, the digital components necessary for processing a readback signal generated in response to a clearance measurement signal. In FIG. 6, a read head 120 reads the clearance measurement signal from a track on a surface of a disk 121. The disk spins at discrete velocity w i i=1, 2, 4, . . . . A sampling switch circuit 105 samples and digitizes the output x(t) of an arm electronics (AE) amplifier 106 at a rate (1/T i ) which is proportional to the disk spindle speed w i , where T i is the sampling period. Digital bandpass filters 107 and 108 filter out the first and third harmonic signal components of the sampled readback signal, respectively. Due to the spatial sampling described above, the coefficients in the filters 107 and 108 are independent of the rotational velocity w i . The outputs of the bandpass filters 107 and 108 are fed, respectively, to amplitude detectors 109 and 110. The amplitude detectors average the outputs in the filters 107 and 108 to produce the instantaneous amplitudes of the first and third harmonics, which are designated respectively as y 1 (m) and y 3 (m). The logarithmic ratio of these instantaneous amplitudes is output by log ratio circuit 112. The signal output by the log ratio circuit 112, denoted as HRF(m) is proportional to the head/disk clearance (flying height) at the rotational velocity w i .
Those skilled in the art will appreciate that a small number of consecutive samples lie over a small physical space of the readback signal x(t) will produce a corresponding value for HRF(m), and that this value can be associated directly with a location on the track where the clearance measurement signal is recorded. In other words, the sequence of discrete values exhibited at the output of the log ratio circuit 112 represents a sequence of relative head/disk clearances at a corresponding sequence of locations on the measurement signal tract and that the log ratio outputs can be mapped to those locations by counting the number of samples, beginning at some predetermined track location.
Those skilled in the art will appreciate that a slight variation of the circuit illustrated in FIGS. 6 will serve to provide the same spatially-mapped sequence of signals by a temporally-based operation. In this regard, the temporally-based operation is similar to the spatial operation described above except that the sampling rate of the switch circuit 105 is fixed at 1/T, where T remains fixed. The band pass filters 107 and 108 now have algorithmic coefficients that are scaled relative to the discrete rotational velocity w i . These sets of coefficients are labeled K 1 (i) and K 2 (i), where:
K.sub.j (i)=[K.sub.j (i,0),K.sub.j i,1),K.sub.j (i,2), . . . ]; j=1,3
These coefficients can be stored in a look-up table in read-only memory which is accessed in synchronism with the incrementation of the disk rotational velocity during clearance measurement. Under these conditions, the output of the log ratio circuit 112 will be similar to that obtained spatially as described above.
Those skilled in the art will appreciate that the components illustrated in FIG. 6 in either their spatially- or temporally-controlled forms may be implemented by using well-known means either in the digital read channel electronics 24, as an invokable process in the clearance and glide program 33, or partially in both of these components.
FIG. 7 illustrates implementation of the control of the clearance test procedure, and may be implemented, using well-known digital programming techniques, as part of the clearance and glide program 33. The clearance measurement procedure is started by selecting a head/disk pair, positioning the head at a selected disk track and then selecting the initial disk velocity in either "spinup" or "spindown" mode. Once head, track, and velocity have been established, the clearance measurement control component generates a clearance signal corresponding to the disk speed. The clearance signal is provided to either set the sampling rate of the sampling circuit with respect to the disk speed, or the coefficients of the bandpass filters. Next, an initial location is selected on the designated track. The harmonics for the HRF calculations are measured. The head/disk clearance is calculated using the HRF procedure and the results are stored. Alternatively, the harmonic components could be stored and the calculation of HRF clearance left to follow completion of all measurements. After f 1 and f 2 have been measured at the initial location, the next sample corresponding to the next track location in sequence is accessed, the harmonic frequency calculated, and so on, until measurements have been made of the last location on the selected track. Next, the loop comprising clearance signal generation and measurement of harmonics at the sequence of track locations is traversed again for the next disk speed, and so on. When all sample locations for the highest (or lowest) disk velocity have been measured, the selected head may be positioned at another track for another set of HRF measurements at particular locations around the tract. Measurements are made for as many tracks as design or operational considerations call for and then another head/disk pair is selected and the sequence is repeated.
GLIDE MEASUREMENTS
Glide testing is a disk surface evaluation which is currently made prior to the disk file assembly step in the manufacturing process. As presently practiced, the glide test is a once off procedure which is not performed again during the operational lifetime of the disk. In glide testing, a measurement signal is laid down on a test track of a disk, the disk is spun at its operational velocity, and a readback signal is developed from a head which is positioned over the track at a premeasured height. The magnitude of the readback signal is directly dependent upon head/disk clearance. The glide test seeks changes in the head/disk clearance, reflected by changes in the readback signal which are, more likely than not, attributable to irregularities on the disk surface such as asperities. As is known, asperities can result in catastrophic failure due to head/disk contact.
Referring once again to FIG. 6, it will be appreciated that a clearance measurement signal laid on a disk track can serve the additional purpose of providing a readback signal whose continuous magnitude provides a profile of the disk surface area where the track is written. In FIG. 6, the signal used for glide testing can be derived either from the output of the amplitude detector 109 (the first harmonic signal, y 1 (m)) or the output of the amplitude detector 110 (the third harmonic signal). The selected signal is called the continuous modulation detection (CMD) signal. In FIG. 6, the first continuous modulation detection signal CMD 1 (m) is the instantaneous amplitude of the first harmonic signal, while CMD 3 (m) is the instantaneous amplitude of the third harmonic signal.
According to the invention, the surface of a disk (such as the disk 121) is evaluated for mechanical defects by the glide testing procedure. For the invention, disk mechanical defects are identified by measuring the amount and form of displacement of a head relative to a disk surface. Displacement is measured using the process readback signal in the form of either the first or third CMD signal described above.
In the invention, the glide test is performed initially at the time of disk file assembly. In addition, using this invention, it can also be performed at any later time during the life of the disk file. The glide test procedure steps are as follows:
1. A given head is stepped radially across the portion of a disk that is to be glide tested. The physical radial distance between the tracks on the disk must be less than the width of the rail (or pad) of the head having the lowest of flying heights, that is the head which is closest to the surface of the disk, and the greatest width. This restriction will ensure that any disk defect has a chance to contact the lowest flying rail or pad of the head. Without this restriction, it is possible that a disk defect might be missed.
2. At each track position, either the entire track or a portion of the track is measured for a defect. The detection phase is accomplished by digitization of the selected CMD signal and then determining from the digitized samples if head contact with a disk defect has occurred. This is accomplished by comparing "the instantaneous" peak or root mean square (RMS) amplitude to an "average" peak or RMS amplitude. If the difference between the values is greater than a predetermined threshold, the same digitized samples are analyzed to determine if a "contact signature" is present. FIG. 8 shows an example of a disk defect found during the detection phase. In FIG. 8, each sample number represents the instantaneous or RMS amplitude of the readback signal generated in response to a measurement signal on a disk track at a track location which can be determined from the sample number. In FIG. 8, the samples are averaged, the average being indicated by reference numeral 120. The amplitude range denoted by T is the required threshold difference between the average and minimum sample values to continue in a defect "characterization" mode. For each track, or track portion, having a measurement signal, the detection process is used to decide if further defect characterization is required. If not, defects are detected after checking the entire track or track portion, the head is accessed (moved) to the next track having a measurement signal. The detection procedure is then resumed.
3. If a defect is detected during the detection mode, the defect is characterized either as a "glide defect" or as a non-contact defect. Importantly, a glide defect is a disk defect that is substantially in contact with the head. FIG. 8 illustrates a potential glide defect, where the amplitude profile from sample 121 through 123 indicates a rapid decrease in the head/disk clearance. Further, the sample values at points 122 and 123 along the disk track fall below the range defined by the threshold difference T between the average and minimum sample values required to continue to characterize a track. In the circumstances illustrated by FIG. 8, it can be determined whether head/disk contact occurs by comparing the magnitude values at sample locations 122 and 123 with a value expected if a head were to contact a disk defect.
4. If, after checking all track locations identified during detection, there are no glide defects, the head is moved to the next track and the detection process begins again (that is, there is a loop back to step 2).
5. If a glide defect is found on a track, the action taken depends upon when the glide test is being performed. If the glide test is being performed in manufacturing, for example, the disk with the defect would be replaced. If the defect is detected later in time after the disk file has been manufactured and placed in service, then the result of the defect characterization is sent to the predicted failure analysis (PFA) procedure.
PREDICTIVE FAILURE ANALYSIS
The PFA procedure undertakes several analyses. These analyses answer the following questions:
a. Is a glide defect new?
b. For a detected glide defect, are there other proximate glide defects on adjacent tracks?
c. If a glide defect has been previously detected, has its apparent height increased since the last recorded measurement?
d. If new, is the height of a glide defect above a critical threshold?
If questions b, c, or d are answered in the affirmative, the PFA procedure invokes the host interface 42 to provide a message to a host computer that a head/disk failure is imminent.
The purpose of the predictive failure analysis (PFA) mechanism, comprising elements 34, 44, and 45 in FIG. 1, is to determine, based on measurements made using this invention, if a disk file failure due to head crash is imminent. The information available to the PFA is that stored during head/disk and glide test measurement procedures. As discussed above, these measurements are mapped by test procedures and sample number to precise disk locations and stored for use by the PFA procedure. The PFA 10 procedure uses both trend and instantaneous information to make a decision.
For the head/disk clearance, the PFA procedure compares results of periodic measurements to determine if a significant trend, either toward increasing or decreasing clearance, is present. There are many statistical methods available to efficiently perform this analysis in the form of an invokable procedure in the components 34 and 44. If a significant trend is found, the host computer is notified.
Also, for head/disk clearance predictive failure analysis, if a single head shows a significant change in clearance as compared to other heads in the same disk file, and this change is "significant", where, "significant" is a matter of design choice, then the PFA components will notify the host computer.
For either analysis, head/disk clearances are measured as described above at any number of locations on any number of tracks on any number of disks in the disk file. These results can be saved in PFA storage 45 and/or on a disk log.
FIG. 9 illustrates a flow chart for predictive failure analysis according to the invention. Note that both an immediate and trend analysis of the glide and clearance data is performed. By using both types of analysis, the predictive failure analysis procedure can react to both fast and slowly changing conditions in the disk file.
Accordingly, it has been shown that the invention enables the practitioner to make and maintain measurements of head/disk clearance and disk surface characteristics not only at the time of disk manufacture, but at any time during operation of a manufactured disk file. The ability to monitor these parameters over time using native disk file electronics solves the problem of inexpensively monitoring disk file performance during the lifetime of a disk file and eliminates external test hardware now used only during manufacture and assembly. Disk performance testing can be accomplished at any time in the life of the disk file and the results may be saved to support trend analysis. The existing disk file components can be used on a part-time basis to make the measurements. The servo processor, for example, may be used for clearance measurements during its normal idle period when the disk file is spinning up and/or down. Through the use of shared digital filters, all of the frequency domain analysis can be performed without any significant impact to the storage already in the disk file. The implementation of this invention is also independent of the recording channel used. Through the us of spatial filtering, whereby the readback signal is sampled spatially, the requirements for very high sampling rates and large RAM storage in a disk file are eliminated. Spatial filtering also permits very flexible bandpass filter designs for glide testing.
Optimizations of the HRF method are known and the inventors expect that they will be employed in the invention. For example, improvement of the signal-to-noise value of the measurement signal may be realized by using a signal written that consists of only the first and third harmonics which would optimize measurement accuracy. Similarly, the bandwidth of existing HRF analysis means is approximately 20 kHz. This is insufficient for future glide testing as air bearing frequencies will be on the order of 100 kHz. The disclosed method of glide testing has not such band width limitations.
By using digital filters rather than analog filtering techniques, much more consistency can be expected from the measurements made in this invention as digital operations are transportable and identical. This means that any disk file making clearance and glide measurements will employ a measurement process identical with that of any other disk file. Also, by using digital filters, the need to perform a discrete fourier transform in order to determine the harmonic amplitudes is avoided by use of the invention embodiment in which spatial sampling of the read back signal is based on disk rotational velocity.
Using the on-board signal processing capability according to the invention, rather than performing testing by a SCSI interface, means that tests will be performed faster. Consequently, higher throughput rates will be realized in manufacturing. Incorporation of productive failure analysis provides minimal user impact during lifetime self-assessments of any disk file.
Unlike in-use HRF analyzers known to the inventors, phase-lock techniques are unnecessary for synchronous detection of read back signal harmonics in this invention. This is important in manufacturing when an HRF analyzer cannot phase-lock.
Last, the invention is applicable to any recording technology having a Wallace spacing loss relationship. This includes disk files incorporating inductive and magnetoresistive head technology.
Obviously, while the invention has been particularly shown and described with reference to the preferred embodiment described above, it will be understood by those skilled in the art that many changes in form and detail may be made therein without departing from the spirit and scope of the invention. | The invention produces and maintains clearance and glide test results for a disk file, stores these results, and monitors head clearance and disk asperities over the useful life of the file using native disk file electronics. The disk file includes a predictive failure analysis component which utilizes clearance and glide test results to predict impending failure of a disk in the disk file. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
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REFERENCE TO A MICROFICHE APPENDIX
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a high-speed laser-based via generation system for producing through-substrate and blind vias to make interconnects in high-density microelectronics systems. More particularly, this invention relates to an opto-mechanical system which delivers controlled pulses of laser energy to a large number of program-selectable via sites simultaneously at very high optical efficiency regardless of the number or density of vias. The system delivers the full energy of the laser among the vias being generated through the use of a high-speed opto-mechanical beam-steering system and a specialized energy recycling illumination system.
(2) Description of Related Art
Vias, the small diameter holes through one or more substrate layers, play an important role in electronic manufacturing because they provide the interconnections between layers in electronic modules. Electronic manufacturing has evolved to provide denser, faster, and more complex packaging technologies which rely heavily on a large number of micro-vias—vias with diameters less than about 150 μm—to provide the increasing number of required interconnections. The generation of these vias in electronic substrates has become a throughput-limiting and crucial step in the fabrication of advanced electronic modules. Via numbers and densities in these modules have increased to keep pace with the increasing complexity of electronic devices, but current via generation technologies cannot keep up with this growth and are fundamentally limited with respect to achievable throughput rates. This invention seeks to address this problem.
Depending on the application, the vias may need to be generated in regular, periodic patterns, such as in chip carriers, or in non-periodic patterns, such as on high density interconnect printed wiring boards. Often the vias need to be drilled through one or several substrate layers. Almost as often, the vias need to be generated such that they terminate or bottom out at a particular layer or depth—these are called blind vias. The vias need to be generated in a wide range of electronic substrate materials. These materials are most commonly dielectric polymers or glass-filled epoxies, but can also be more mechanically durable materials such as ceramics and metals. The wide range of substrate material properties poses a challenge for via generation systems.
Several technologies currently exist for via generation in electronic substrates: conventional mechanical drilling using metal or ceramic bits; lithographic patterning of the via pattern followed by chemical or plasma etching of the substrates; and direct laser photo-ablation. The mechanical technologies cannot produce micro-vias at high throughputs or with fine dimensions due to breakage of the bits and minimum diameter limitations. Lithographic and etching technologies are expensive, require multiple processing steps, are difficult to reconfigure, and are hard to control in depth for blind via applications. Optical technologies using laser photo-ablation show the most promise for rapid, clean production of micro-vias in a variety of substrates, but current systems are too slow to keep up with current production demands. This is mainly due to the serial nature of the via generation process and the power limitations of current frequency multiplied solid-state laser systems.
Laser via generation through photo-ablation provides many advantages: it allows a multitude of materials to be drilled without generation of harmful debris; it allows flexibility in via diameter, depth, and placement; and it typically does not require additional process steps. Photo-ablation is the process by which material is broken down to its smaller molecular or elemental components by being irradiated by a very high-fluence beam of ultraviolet radiation. For most materials photo-ablation is most efficient for radiation in the UV-region of the spectrum since most materials absorb energy very strongly at these wavelengths. For each material and laser wavelength there is a photo-ablation threshold fluence above which ablation occurs efficiently, and there is a photo-etch rate that characterizes the rate at which the material is ablated away. For most dielectric materials used in electronics manufacturing the ablation threshold fluence can range from about 100 mJ/cm 2 to several Joules/cm 2 at wavelengths near 300 nm, and etch-rates for 1 J/cm 2 fluences at these wavelengths are typically 0.5 μm/pulse. For this reason, powerful UV lasers are required to generate vias efficiently. Currently, only excimer lasers such as XeCl and certain frequency-multiplied solid-state lasers such as Nd:YAG can deliver the required fluences. Excimer lasers are attractive because they are the most powerful of these, whereas frequency-multiplied solid-state lasers are used due to their high repetition rates and focusability.
Systems which use solid-state laser sources typically focus the low average power, frequency-multiplied beam into a very small spot—typically about 20 μm in diameter—to achieve the high fluences required for photo-ablation. They generate the required via patterns by a combination of galvo-mirror beam deflection to move the spot on the substrate and automated planar (X-Y) stage motion to present different areas of the substrate to the beam. The throughput of these systems depends on how quickly the focused laser spot can be moved from one via site to the next, by the dwell time required at via site, and by the average power of the laser source. Although this process can be easily programmed and is, thus, very flexible, it is essentially a serial process, and therefore, has an inherently low throughput. In addition, via diameters are limited to a minimum size of about 20 μm.
Systems using scanning mask projection and high-power excimer lasers for massively parallel via generation have been described in Jain, U.S. Pat. No. 5,285,236. Such systems capitalize on the much greater powers delivered by excimer lasers to generate the required fluences over large areas of the substrate. In these systems a large-area, uniform beam is produced by a specialized illumination system, as described in Jain, U.S. Pat. No. 5,059,013, and Farmiga, U.S. Pat. No. 5,828,505. This beam illuminates a via pattern on a mask which is projected onto the substrate by a projection imaging system. In such a system, all the vias in the illuminated region are generated simultaneously, the throughput being limited only by the etch-rate of the material and not the number of vias. For very dense via density applications, this type of system can achieve extremely high throughputs, especially when the illumination system incorporates energy recycling as described in Hoffman and Jain, U.S. Pat. No. 5,473,408. For low via densities, however, such a large-area projection system can be slow and inefficient. In addition, such a system is not very flexible in that it requires expensive masks to be generated for each required via pattern.
Current electronic manufacturing demands via generation systems with the programmability of the serial solid-state laser-based systems and the high throughputs of the massively parallel excimer laser-based systems. Highly desirable features are high-speed via generation; full via pattern programmability—including via diameter, position, and depth; capability to drill high-threshold photo-ablation substrates; and full and efficient utilization of available laser energy. The invention described below provides all these features. It makes full and efficient use of the power available from excimer lasers and provides full programmability of the via pattern.
BRIEF SUMMARY OF THE INVENTION
This invention is a via generation system which produces vias in a variety of microelectronic substrate materials by the process of laser photo-ablation. This system optimally utilizes the full energy available from the laser source by efficiently dividing and channeling the radiation into a number of beams which is exactly the same as the number of vias to be generated in a given module region. The system ablates all vias in a particular module region simultaneously and allows excess energy (i.e., the unused beam energy due to absence of a via at a location) to be ‘recycled’ to speed the process and make it more efficient. A computer control system allows each via location, size, and depth to be fully programmed and automatically generated. The various subsystems, objects, features, and advantages of this via generation systems are described in more detail below.
An excimer laser, such as a high-power xenon chloride laser operating at 308 nm, serves as the radiation source for the system. The output beam from this laser is shaped and uniformized by the illumination subsystem, a system of optics including standard lens elements and a ‘homogenizer’ unit. The homogenizer unit includes a special mirror at its input end that allows reflected radiation from further down the optical train to be returned into the train for more efficient utilization, in effect recycling the reflected energy. The output of the illumination subsystem is an approximately collimated beam with excellent intensity uniformity and the proper cross-sectional shape, typically hexagonal to allow for densest packing of via-generating beamlet grid as will be described below. The output beam is sized to obtain a high enough fluence at the substrate for photo-ablation; larger beams allow higher throughputs, but the fluence drops as the area is increased.
The shaped, uniformized, and collimated laser beam enters the beamlet steering subsystem which directs the radiation to the proper via sites. The beamlet steering subsystem is a high-speed opto-mechanical system that divides the incident beam into many beamlets and allows computer-controlled steering of each individual beamlet produced to a selected via site.
In the first embodiment of the invention, the nearly collimated input beam from the illumination subsystem is divided into an array of beamlets by a two-dimensional array of micro-lenses known as a fly's-eye lens array. Each lenslet in the array focuses a small fraction of the incident beam onto a single, corresponding, tip-tilt mirror element in a computer-controlled two-dimensional tip-tilt mirror array. The mirror elements in this array are actuated by high-speed actuators such as piezo-ceramic pistons working in groups to accomplish the required tip-tilt motion. The computer control specifies the tip and tilt angles of each mirror element, and, thus, the direction in which each beamlet will be reflected. In this way, computer-controlled simultaneous steering of a large number of beamlets is realized. The beamlets are directed by the steering mirror array into a large array of optical fibers which channel the radiation to the substrate either directly (close proximity) or by a projection lens (which allows a large working distance). Each steering mirror element can direct its beamlet into one of several fibers within its steering range. Typically one mirror element can address any one out of seven fibers packed in a dense, hexagonal array. Beamlets which are not required for ablation (if the number of vias being patterned is less than the maximum), can be reflected back into the energy-recycling illumination subsystem which reuses the available radiation. The optical fiber array covers a certain region of the substrate and each fiber can deliver radiation for photo-ablation of the substrate at one location in this region. Thus, radiation is directed to any of a large number of sites on the substrate for via generation. Via target sites which do not fall on the grid formed by the fiber array are accessed by moving the substrate and/or beam-steering system with a precision X-Y stage. The final result is that a large number of beamlets can be efficiently directed to many different via locations on the substrate simultaneously to generate the required via pattern.
In the second embodiment of the invention, a lens system placed after the homogenizer images the input face of the homogenizer to produce a focal spot array which then impinges on a two-dimensional mirror array similar to that described above. This focal spot array (FSA) is formed because the point source of radiation entering the homogenizer undergoes a multitude of reflections within the internally mirrored homogenizer unit and, when imaged, appears as a multitude of point sources corresponding to the number and angle of the reflections produced within the homogenizer unit. The homogenizer and FSA lens are designed to produce the grid of focal spots required. The intensity of the various focal spots in the FSA can be equalized by the use of an apodization filter if required. Each spot in the FSA impinges on a single steering mirror element and is reflected into a projection lens which refocuses the radiation tightly onto the substrate. By controlling the tip and tilt of the mirror elements, each spot can be positioned anywhere in the image field of the projection lens to generate the required via patterns. Multiple beamlets from different mirror elements can be directed to the same via site to speed the ablation process, or unneeded beamlets can be reflected back into the illumination system for energy recycling.
In either embodiment, the computer control system is a critical component as it controls the beam-steering mirror array to position the beamlets at the correct via locations on the substrate and coordinates the other subsystems to generate the vias correctly. The control system reads information on the via patterns from standard CAD files—this information includes via locations, sizes, and depths—and coordinates the firing of the laser, the motion of the X-Y stages, and, most importantly, the tip-tilt beamlet steering mirror arrays to generate the correct via patterns on the substrate. Because all aspects of the beamlet delivery can be controlled, optimized patterning algorithms can be generated to maximize the efficiency of the via generation process.
For each module being covered on the substrate at a given moment the number and location of beamlets needed to address the via sites selected for via formation will be known in advance from the CAD file. The total laser energy required for full ablation, which can be expressed as the number of laser pulses required to drill through the substrate, depends on the number of selected via sites in the module. Since a portion of the incident laser radiation is recycled when the number of vias is less than the maximum, fewer pulses are required to drill this smaller number of via sites. The varying energy requirement from module to module is managed by the control system to ensure that the correct number of laser pulses, and hence energy, is delivered to each site regardless of how many via sites the module contains. This allows a highly efficient use of the available laser power without sacrificing the benefits of massively parallel via generation.
The object of the invention is to provide an efficient system for laser formation of vias in microelectronics substrates over a very wide range of via densities.
A more specific object of the invention is to provide a computer-controllable pattern of high-fluence, shaped, spatially homogenized, pulse-repetition-controlled, and directed laser beamlets at the selected sites of the substrate to form by photo-ablation the desired via pattern in minimal time with optimal efficiency.
A feature of the invention is energy recycling together with computerized control of the number of laser pulses as required for the number of vias patterned in a given module region. In this way, all the vias in a given module region are generated simultaneously with optimal energy utilization, greatly increasing throughput over serial via generation systems and also over mask-projection via generation systems tasked with patterning modules of varying via densities.
A feature of the invention is the pairing of a fly's-eye micro-lens array with a computer-controlled tip-tilt micro-mirror array to steer an array of beamlets into grouped optical fibers. Each pair of a fly's-eye micro-lens and a micro-mirror can deliver a beamlet to one fiber in an optical fiber group which is part of a larger fiber array, e.g., to one of seven optical fibers grouped six-around-one in a tight hexagonal grouping. Each fiber thus addressed channels the radiation to a unique via location on the substrate allowing a via to be generated there by photo-ablation.
Another feature of the invention is the pairing of a focal spot array generating optical system with a computer controllable tip-tilt micro-mirror array to position beamlets through a projection lens onto selected via sites on the substrate, thereby generating the desired via pattern by photo-ablation.
Another feature of the invention is computer control of the number of laser pulses applied to a selected substrate module region as a combined function of number of vias to be drilled and calculated energy recycling.
Still another feature of the invention is selective fine positioning of the vias within the substrate module by computer controlled displacement, jittering, overlapping, rotating, or other motion of the substrate stage or beamlet steering optics as required to allow for via generation at any set of points on the substrate. This allows vias to be generated with a closer spacing than would be possible with mask-based systems.
An advantage of the invention is that the via generating process can be optimized for each module region of the substrate (for high throughput) by full control of the applied irradiation. The control computer can calculate the optimal number of pulses, beamlet positions, and X-Y translation schedule based on the desired via pattern and the energy recycling factor.
Another advantage of the invention is the ability to use recycled radiation energy to increase the rate of generation of vias in low- to medium-density patterns.
Another advantage of the invention is that the same system may be efficiently used for generating via patterns over a large range of via densities range on the same substrate.
Other objects, features and advantages of the invention will be apparent from the following written description, claims, abstract, and the annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the illumination, beamlet generation, and beamlet steering optical systems, including the energy-recycling homogenizer, fly's-eye lens array and tip-tilt micro-mirror array. The figure depicts the precise delivery of three beamlets to the predetermined optical fibers in the optical fiber bundle, and the reflection of one unused beamlet back to the homogenizer for energy recycling.
FIG. 2 is a schematic representation of the optical fiber bundle with the substrate positioned near its output. A plan view detail illustrates the concept of hexagonal grouping of the optical fibers and the optimization of illumination by this grouping.
FIG. 3 is a schematic side view of the beamlet formation and steering system, including a 2-D fly's-eye microlens array and a controllable 2-D tip-tilt mirror array. The figure illustrates how the individual mirror elements can tilt to direct a beamlet to an individual fiber in the bundle.
FIG. 4 a is a plan view of the controllable tip-tilt mirror array showing a close packed hexagonal arrangement of the hexagonally shaped mirror elements.
FIG. 4 b presents an alternative mirror array arrangement with a 2-D rectangular geometry.
FIG. 4 c presents an alternative mirror array arrangement with a 1-D linear geometry.
FIG. 5 is a schematic perspective view of the rectangular mirror array showing how an individual mirror element reflects a beamlet in the desired direction.
FIG. 6 shows a schematic representation of the system using a focal spot array generator and projection lens to form and steer the individual beamlets.
FIG. 7 shows a variation of the first embodiment of the invention with the inclusion of a projection lens between the exit face of the fiber bundle and the substrate.
DETAILED DESCRIPTION OF THE INVENTION
This invention is a high-resolution, high-speed programmable via generation system which produces vias in a variety of microelectronic substrate materials by the process of laser photo-ablation. This via generation system efficiently divides the full available energy from the laser source among multiple via generating beamlets. The highly efficient illumination system allows the energy in unused beamlets to be ‘recycled’ into the system. Two preferred embodiments of the invention are described. In the first embodiment, the beamlets are formed by a fly's-eye lens array and directed by a micro-mirror array to a fiber bundle which channels the radiation to the substrate. In the second embodiment of the invention, the beamlets are formed from a focal spot array (FSA) and directed by a similar micro-mirror array through a projection lens onto the substrate.
FIG. 1 presents a schematic layout of the first embodiment of the invention and shows the optical path through the system. Radiation originates from the excimer laser source 26 and is fed into the beam-conditioning optics 43 which roughly shape and collimate the beam. The roughly collimated beam 27 is steered by a fold mirror 28 and then focused by a focusing lens 44 into the energy-recycling homogenizer 30 which makes the beam's intensity uniform and gives it the proper cross-sectional shape in the exit plane 34 . A condenser lens 35 then collimates the output beam 36 . A steering mirror 37 directs this beam into a 2-D fly's-eye microlens array 10 which breaks up the collimated beam 36 into an array of converging beamlets such as 38 . Each of these beamlets, e.g. 38 , impinges on a single mirror element, e.g., 39 , of a tip-tilt micro-mirror array 12 . Each mirror element, e.g. 39 or 41 , of the array 12 can be tipped and tilted by a computer-controlled servo system. Each mirror element, such as 41 , also can be tilted enough to retroreflect the beamlet incident upon it to enable the unused beamlet to be directed back into the homogenizer 30 so its energy can be ‘recycled’ into the system. Each mirror element, e.g. 39 , can steer the beamlet incident upon it, e.g. 38 , into one of several fibers, e.g. 40 , in a fiber bundle 1 . The individual fibers, e.g. 40 , of the fiber bundle 1 are arranged in a grid pattern such as the one illustrated in FIG. 2 . Each fiber is positioned over a potential via site 4 . The fibers channel the beamlets down to the substrate 2 (mounted on a substrate stage 58 ) where the radiation in the beamlets forms the vias by the process of photo-ablation. The radiation may either propagate from the fiber across a small gap to the substrate 2 or be imaged by a projection lens (not shown) between the fiber bundle 1 and the substrate 2 . The various subsystems of this first embodiment will be described in more detail below.
FIG. 6 schematically illustrates the layout of the second embodiment of the invention. In this embodiment, as in the first, an excimer laser 26 provides the radiation. The illumination system 46 is very similar to that of the first embodiment of the invention and consists of beam-conditioning optics 43 , a focusing lens 44 , an energy-recycling homogenizer 30 , and a condenser lens 35 . In the second embodiment, however, the condenser lens forms a focal spot array (FSA) 47 by a process to be described below. Each beamlet, e.g. 38 , exiting the FSA is incident on a single mirror element, e.g. 39 , as in the first embodiment. In the second embodiment, each mirror element, e.g. 39 , of the micro-mirror array steers the beam through a projection lens 48 to hit a particular target via site, e.g. 49 , in the addressable area 50 on the substrate panel 2 mounted on a stage 58 . Individual subsystems of the two preferred embodiments of the invention will be described in more detail below.
For both embodiments of the invention, the radiation source is an excimer laser 26 . A XeCl excimer laser operating at a wavelength of 308 nm is preferred. This type of laser typically fires pulses with an average pulsewidth of 30 ns at repetition rates up to several hundred Hz giving average powers up to 200 W. This power output is ten to a hundred times greater than what can be produced by the frequency-multiplied solid state lasers used in some via generation systems. The output beam of such an excimer laser is usually very non-uniform in intensity, highly divergent, and rectangular in cross-section. For this reason the output beam must be uniformized, conditioned, and shaped before it can be used in a controlled manner. The illumination system, which will be described below, accomplishes this.
The illumination consists of several optical components which uniformize, shape, and relay the excimer laser beam: the beam-conditioning optics 43 , the beam-steering mirror(s) 28 , the energy-recycling homogenizer 30 , and the condenser lens 35 . The beam-conditioning optics 43 consist of several cylindrical and spherical lenses which equalize the horizontal and vertical divergences of the beam and expand or compress the beam size along one or both directions to make the rectangular output beam nearly square in cross-section. This conditioned beam then is steered by the beam-steering mirror(s) 28 and focused into the homogenizer 30 by the focusing lens 44 . The focal spot is produced inside the homogenizer 30 just beyond the aperture 32 of the homogenizer entrance mirror 29 whose inner surface 33 is reflective. The radiation from this focal spot fills the internally reflecting surfaces of the homogenizer 30 . The beam undergoes multiple reflections, e.g., for ray 31 , inside the long light tunnel which serve to uniformize the beam intensity distribution by averaging non-uniformities in the source beam. The homogenizer 30 preserves the numerical aperture (NA) of the beam produced by the focusing lens 44 and produces a highly uniform output radiation distribution at its output end 34 . The homogenizer 30 can be constructed with a variety of cross-sectional shapes and the output end 34 can be designed to have almost any polygonal shape. The preferred cross-section is hexagonal. The mirror 29 at the homogenizer's entrance face allows rays that are retroreflected further down the optical train to be reflected back into the illumination train to, in effect, recycle the retroreflected radiation energy. A more detailed description of the principles behind the operation of the homogenizer can be found in U.S. Pat. No. 5,059,013, and details of its construction are given in U.S. Pat. No. 5,828,505. Finally, the condenser lens 35 relays the beam from the homogenizer to the beamlet formation and steering system in one of two ways depending on the embodiment of the invention: for the first embodiment of the invention, the condenser lens roughly collimates the output beam from the homogenizer and directs the collimated beam 36 to the fly's-eye lens array; for the second embodiment of the invention, the focal point at the entrance face of the homogenizer 30 is imaged by the condenser to produce a focal spot array (FSA) as will be described in more detail below.
In the first embodiment of the invention, the beamlet formation and steering system consists of a fly's-eye lenslet array 10 and a tip-tilt micro-mirror array 12 which is computer-controlled by signals from the central control unit 60 . The conditioned and collimated laser beam 36 is directed by a fold mirror 37 towards the fly's-eye lenslet array 10 which divides the beam into an array of converging beamlets, e.g. 18 and 38 . The lenslet array can be in several forms: the lenslets, e.g., 11 , can be arranged in a hexagonal close-packed (HCP) array as illustrated in FIG. 4 a , or in a rectangular grid as shown in FIG. 4 b , or in a staggered array, or any other two-dimensional arrangement. Each of the beamlets produced by the lenslets impinges on a single mirror element, e.g. 39 or 41 , of the tip-tilt micro-mirror array 12 . Because of the one-to-one correspondence between a lenslet/beamlet and a micro-mirror element, the mirror elements, e.g. 13 , in the micro-mirror array 12 need to be arranged in configurations similar to those of the lenslet array 10 , e.g. the HCP array shown in FIG. 4 a , or the rectangular array shown in FIG. 4 b , or the linear array shown in FIG. 4 c . The tip and tilt of each mirror element in the array, e.g. 39 , 41 or 13 , is controlled by appropriate actuators, e.g. 14 , providing small rotations of the mirror element about two axes. An appropriate actuator 14 may be a system of three piezo-ceramic cylinders working in concert to produce the required tip-tilt motion of the mirror element 13 . These actuators receive control signals from a computer-controlled servo system 15 , which receives commands from the central control unit 60 . FIG. 3 illustrates how this arrangement works to allow computer-controlled steering of each beamlet 18 into one of several output directions 20 - 22 . Each mirror element, e.g. 41 , is also capable of retroreflecting unneeded beamlets back into the illumination system for energy recycling as shown by ray 42 in FIG. 1 . In this way, a large number of beamlets can be directed into a much larger number of output directions or channels (including retroreflection for energy recycling) by high-speed computer control.
For the first embodiment of the invention, the output channels for the beamlets, 23 - 25 , are the individual fibers 7 of the fiber bundle 1 which form the beamlet-relay system. As shown in FIG. 2, the fiber bundle 1 receives the incident beamlets 3 and is positioned over the substrate 2 . These fibers would typically be UV-grade fused silica with 5 to 10 micron diameter cores and several micron thick cladding. They are potted in a casing 8 . In fiber bundle 1 the fibers form an array with a pitch of 6 to 30 microns depending on the fiber type. The beamlets emerging from the exit face 6 of this array of fibers represents a grid of possible via sites 4 which are selectable by the beamlet steering system 12 . Each selected fiber channels the incident beamlet 18 to the substrate 2 where a via is generated by the process of photo-ablation. The beamlets can either propagate from the output of the fibers to the via sites across a small air-gap between the fiber bundle 1 and the substrate 2 , or be imaged by a projection lens 55 inserted between the fiber bundle 1 and the substrate as shown in FIG. 7 . Many forms for the fiber array are possible, and the fibers can be grouped into small groups, e.g. 9 , each fiber in a group being addressable by a single beamlet. Examples of possible fiber arrays include: a HCP 7-fiber group 9 arranged 6-around-1 as illustrated in FIG. 2; larger HCP fiber groups; rectangular or square arrays; line arrays where each mirror addresses a segment of the line; and other arrays tailored to the types of via patterns that need to be generated. Vias can be generated at any point on the grid produced by the fiber array. If vias need to be placed at off-grid points, the high-precision X-Y stage 58 moves the substrate and/or the fiber bundle exit face is moved to place the vias at any point desired on the substrate.
The beamlet formation and steering system for the second embodiment of the invention differs from that of the first embodiment in its use of a focal spot array (FSA) 47 . The illumination system 46 in this embodiment is largely the same as what was described above: beam-conditioning optics 43 and steering mirrors 28 deliver the beam to the focusing lens 44 which focuses the beam into the entrance aperture 32 of the energy recycling homogenizer 30 . The point source produced at the entrance aperture 32 is imaged by the condenser lens 35 to form a FSA 47 in a plane further down the optical train. In the FSA the image of the point source in the entrance aperture 32 appears surrounded by an array of spots which are the reflected images of the original focus. The number and spacing of the focal spots in the FSA can be specified by the design of the energy-recycling homogenizer 30 . The length and transverse size of the homogenizer, coupled with the NA of the beam leaving the source focus, determine how many reflections different parts of the beam will undergo in the homogenizer, and, thus, the number and spacing of the spots in the FSA 47 . In general, the intensity of the focal spots in the FSA will not be identical, but an apodization filter 51 placed just after the FSA can be used to equalize the intensities of the beamlets leaving the FSA if required. In addition, an aperture array 56 can be used in the plane of the apodization filter to clean up the edges of the beamlets. This arrangement provides a very efficient way to break up the source beam into a large array of individual beamlets. Each beamlet from each spot in the FSA impinges on a single mirror element of a tip-tilt micro-mirror array 12 which can either steer the beamlet or retroreflect it into the illumination system for energy recycling. The computer controlled mirror array 12 is essentially the same subsystem described for the first embodiment of the invention above.
The second embodiment of the invention also differs from the first in the way the beamlets are relayed to the substrate for via generation. In the second embodiment, a projection lens 48 between the mirror array and the substrate images the spots in the FSA to various via sites 49 in the addressable area 50 on the substrate 2 . The exact position of each via site is determined by the tip-tilt setting of the mirror element which steers that beamlet. In this arrangement, beamlets can be steered to any point in the field-of-view of the projection lens, effectively allowing an infinite number of output channels for the beamlet steering and relay system. This also allows for greater capabilities in the positioning of beamlets on the substrate. For example, multiple beamlets can be directed to the same site on the substrate 2 to enable faster via generation. Or, several beamlets can be steered to nearly overlap at a via site to enable faster generation of larger diameter vias. A dithering capability can be added to either the projection lens 48 , the substrate stage 2 , or the tip-tilt mirrors 12 to blend the edges formed by the overlap of multiple beamlets. This beamlet steering configuration has the added advantage it allows the beamlets to be directed into essentially an infinite number of output channels instead of one channel out of several possible. But while this beamlet steering configuration is more flexible, it requires a much higher level of beamlet-steering control, i.e. more complex servo-controls.
For either embodiment of the invention, the central control system 60 is critical for forming the proper via patterns in the substrate. The control system coordinates the actions of all the subsystems to produce the required array of vias: it controls the pulse energy, repetition rate, and number of pulses fired by the excimer laser 26 ; it controls the beamlet-steering mirror array 12 to direct the beamlets to the correct locations on the substrate 2 ; and it controls the movements of the substrate stage 58 and/or the fiber bundle 1 to bring the appropriate areas of the substrate 2 into the addressable area 50 under the projection lens 55 . The central control system 60 reads the via pattern information from standard CAD-type files. These files contain information on the via locations, sizes, and depths. Using this information, the central control system calculates the optimum way to generate the via pattern. The optimization parameters include possible substrate stage paths to cover all via sites, choice of beamlet-steering mirror angles to address the required via sites, and number of laser pulses to be delivered to each via site. The optimal stage paths and beamlet-steering angles are calculated to minimize time, while the optimal number of pulses relies on a number of different factors. The most important of these factors are the via density in the addressable area 50 , the ablation etch rate of the material being processed, the laser pulse energy and repetition rate, and the energy multiplication factor from the energy-recycling illumination system. The energy multiplication factor varies depending on the number of vias in the addressable area—when more beamlets are available than via sites to pattern, unused beamlets can be retroreflected and, thus, recycled, effectively increasing the energy available for the photo-ablation process in the remaining via sites. Since there are so many parameters involved in the via generation process, flexible computer control allows many paths for optimizing the process for different substrate materials and via patterns.
Either of the two embodiments of the invention provides a very flexible via generation system with the following features: high-throughput via generation; the ability to generate any desired via pattern from CAD-type files; flexibility to optimize the process for various materials and via patterns; full utilization of the available laser source power (and since excimer lasers have very high average output powers, this offers large performance benefits over the more commonly used frequency-multiplied solid state lasers); and the ability to recycle the laser energy when via density is low. Each embodiment of the invention has its relative strengths. The first embodiment uses a simpler control method to generate the via patterns. It also allows the fiber bundle geometry to be chosen to specifically match or optimize a particular via pattern (for example a regular square array). Finally, the first embodiment allows the laser source to be located remotely from the via generation system since the radiation can be delivered very efficiently through the fiber bundle. This allows the system to be very compact and have a small footprint. The second embodiment of the invention, on the other hand, provides more flexibility in the placement of vias and in energy utilization, since multiple beamlets can be overlapped at a single via site. This also allows the system to more efficiently generate larger vias or features by partially overlapping beamlets.
Method of Operation
The preferred method of forming vias comprises the following steps:
Step 1) activating a radiation source to produce a beam of pulses;
Step 2) providing such beam of pulses to a beam conditioning subsystem capable of accepting said beam and delivering a conditioned beam of radiation pulses having defined characteristics;
Step 3) providing a set of conditioned beamlets of radiation pulses;
Step 4) positioning a spatial light modulator array so that said set of conditioned radiation pulse beamlets are incident upon the spatial light modulator array in a defined pattern, transmitting selected beamlets in a defined subpattern, and reflecting unselected beamlets back into the beam conditioning subsystem for re-reflection so as to be re-incident upon the controllable spatial light modulator array;
Step 5) presenting a substrate;
Step 6) projecting said selected beamlet subpattern from said spatial light modulator array onto said substrate; and
Step 7) controlling the pulses from the radiation source, controlling the beam conditioning, and controlling the substrate presentation for delivering pulses of defined characteristics upon the substrate for via formation.
TABLE 1
System Design Example and Estimated Throughput for
High-Speed Maskless Via Generation System
Material to be ablated
Polyimide
Thickness to be removed
12.5
microns
Ablation etch rate
0.6
microns per Joule/sq. cm
Dose (fluence)
2
Joule/sq. cm
Number of steering mirrors
61
Number of fibers
427
Number of selected fibers per
14
(approx. 1 out of every 30)
bundle
Energy recycling multiple
4
Laser repetition rate
1000
Hz
Point-to-point move time
11
msec
Via density
200,000
vias/sq. ft.
Via generation throughput
1000
vias/sec or 18 sq. ft./hr
System Example and Throughput Estimate
In this section we present an example of a system design and throughput analysis which demonstrates the attractive performance of the new via generation system. To arrive at the throughput estimates, we use realistic system parameters and representative manufacturing requirements. The key parameters which influence the throughput are: (a) material properties such as ablation threshold, intrinsic etch rate, and thickness; and (b) the density of the vias and their distribution across the substrate. The system throughput will therefore also show dependence on the design of the interconnect structure of the electronic module. The results of the throughput analysis described below are for the representative case of via generation in 12.5 μm thick polyimide layers. Table 1 shows the throughput figures we have estimated along with the key system design specifications that were used in the calculation.
The system throughput determination is based on the drilling time required for a group of vias (i.e., the vias addressed by one position of the fiber bundle), the time required to move between drilling regions (the region-to-region move time), and the total number of via generation regions, and is calculated by the following equation:
T =( D+M )* N (1)
where T is the total drilling time, D is the drilling time for vias in one region, M is the region-to-region move time, and N is the number of drilling regions. The via region drilling time is a function of the thickness of the material, the fluence delivered to the substrate, and the etch rate of the substrate material. Note that neither the via hole size nor the number of vias in the region have a major effect on the drilling time for this system concept. Rather, they affect the required laser power and fiber bundle design. In this case, a 15 W excimer laser was used to generate holes up to 100 μm in diameter, and a fluence of 2 J per sq. cm was easily obtained. If higher fluences are required, such as for the ablation of metals and other inorganics, they can easily be generated with a higher-power laser (excimer lasers with up to 200 W of average power are commercially available). Finally, the recycling multiple of the energy recycling homogenizer has an impact on the throughput. Multiples of up to 5× have previously been shown to be possible; we have conservatively chosen a multiple of 4× with the knowledge that the eventual number will vary according to the number of vias being ablated simultaneously at any particular region.
The calculation of the region-to-region move time depends on the average distance moved and the acceleration of the positioning stage(s). We have surveyed the specifications of several commercial high-speed scanning stages to determine the acceleration. The distance between via generation regions is expected to vary according to the design of the interconnect structure, the overall density of vias, and the distribution of the vias across the substrate. Although the move time will decrease with shorter distances between regions, the total number of regions will then increase, thereby adversely affecting the throughput. Accordingly, the more uniform the distribution of the vias, the larger the number of via generation regions and, therefore, the lower the net drilling throughput (that is, the system will lose some of its advantage as a highly parallel via drilling machine). The system throughput goes up dramatically with the introduction of local areas of high via density because the number of via generation regions decreases and the benefits of multiple-up via generation can be realized. Such interconnect designs are, in fact, quite common in IC packaging applications. It is therefore reasonable to assume that the average number of vias to be generated per region (the same as the number of selected fibers) ranges from 10 to 20. Using a number in this range and a via density in the range of 100,000 to 300,000 per sq. ft. (which is representative for the high-performance multichip electronic modules), the move distance, move time and number of regions are calculated. Finally, the system throughput is determined according to the via density divided by the total drilling time.
The above throughput projection illustrates the fundamental advantages of the system disclosed in this invention, namely, its ability to combine the benefits of using a high-power excimer laser source, utilizing the source power fully, highly parallel via generation, and programmability in via configuration and site selection.
While the invention has been shown and described with respect to the above preferred embodiments for via generation, it will be obvious to those skilled in the art to use the apparatus and technique for more generalized material processing or treatment by use of controlled photo-ablation or high-fluence photo-treatment, making alterations within the spirit and scope of the invention as defined in the following claims. | High-performance microelectronic modules, such as chip-scale packages, flip-chip modules, integrated micro-opto-electronic boards, fine-line printed circuits, and system-on-a-package modules, span a range of sizes and interconnect densities. Current technologies for via generation are not optimized for the varied cost considerations of different manufacturing requirements—direct-write tools address low-volume needs, whereas mask-projection systems are designed for very high via-density products. The system disclosed here will be highly cost-efficient for producing a wide range of modules. Its desirable features are high-speed via generation for different via densities, full via-pattern programmability, capability to drill high-threshold photo-ablation substrates, and full and efficient utilization of available high-power excimer lasers. A high-power laser beam is divided into multiple beamlets which are simultaneously directed to different via sites by a spatial light modulator array. Beamlets not needed for via generation are returned to the illumination system and recycled with the beamlets that reach via generation sites. A control system uses via site information and material characteristics to direct necessary numbers of laser pulses to selected via sites for optimum via generation efficiency. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to electrolytic etching and milling of metal alloys, particularly nickel superalloys.
Nickel superalloys, such as are used for high temperature service in gas turbines, are quite difficult to machine by conventional processes. Electrolytic etching is a particularly attractive method for removing small quantities of such metals, especially when small depressions or grooves are sought on the surface of a workpiece. Generally, electrolytic etching comprises the selective removal of portions of a workpiece by the combined action of an electric current and a corrodent. The conventional method of electrolytic etching involves immersing the workpiece in an electrolyte with an electrode and applying an electric potential so that the workpiece is anodic. Metals vary, of course, in their susceptibility to electrolytic etching. Many advanced nickel superalloys are by metallurgical design resistant to corrosive elements, including the acids normally used for electrolytic etching. They are complex, multi-phase materials and it is often found that the different phases vary in their rates of removal. Conventional electrolytic etching of the more highly alloyed nickel superalloys is found to result in a rough and uneven surface coated with a substantial sludge residue of complex compounds of tungsten, titanium, and molybdenum. The conclusion of experience is that superalloys having substantial amounts of the foregoing elements, as a class, present the most electrolytic etching difficulty.
The most common application of electrolytic etching is the simple smoothing, or electropolishing, of a surface, by the removal of relatively small quantities, i.e., under 25 μm of material from a surface. In other instances, small depressions or grooves are sought. To accomplish this, the workpiece is coated with an insulative material, or resist, in portions not to be removed. Generally, accurate definition is achieved when the depth of the depression is relatively slight. However, when it is sought to create depressions where the depth is appreciable, compared to the surface plane dimensions, it is found that the depressions are widened from the widths defined by the resist. Thus, for example, a groove of 1.0 mm width, as defined by a resist, when etched to a depth of 0.35 mm may be found to increase in width by as much as 60% to a width of 1.6 mm. Furthermore, the side walls of the groove will be tapered outwardly, e.g., the groove will be wider at its top than it is near its bottom. These lateral dimensional effects are characterized as "side etch". Adding to the undesired side etch effect, as grooves are cut deeper the previously mentioned uneveness and roughness are accentuated. Consequently, it is quite difficult within the state of the art to form grooves which have controllable surface finish, uniform depth, and consistent width.
Another problem frequently encountered in electrolytic etching occurs when a workpiece has separated etchable portions with varying surface areas: the larger areas will suffer greater material removal rates than the smaller areas. Therefore, in the absence of special techniques, uneven and uncontrolled depths will result at different locations in the workpiece.
Of course, some of the foregoing problems may be overcome by using various laboratory-type techniques, e.g., separately etching narrow grooves from wide grooves, using different sequences of electrolytes, and so forth, but these are not suited to the requirements of production of a multiplicity of parts. Therefore, there is a need for an electrolytic etching technique adapted to economically create uniform width, depth, and surface finish grooves of substantial depth, especially in nickel superalloys.
SUMMARY OF THE INVENTION
An object of the invention is improved electrochemical fabrication of difficult-to-machine metals. A more particular object is the efficient and repetitive formation of depressions or grooves having uniform depth and surface finish, even when the depressions have varying widths and are scattered irregularly across the surface of a high temperature nickel superalloy.
According to the method and apparatus of the invention, exposed surfaces of a resist coated nickel superalloy are electrolytically etched using periodically reversed current. The workpiece is placed in an electrolyte with the surfaces to be etched facing vertically upward, to allow the escape of gases liberated at any surface with minimum interference with etching at other locations. The electrode is placed above the workpiece.
According to the invention an aperture containing shield is interposed between the workpiece and the electrode. The shield aperture is made substantially smaller than the workpiece area containing exposed surfaces and produces a desirable current distribution on the workpiece. The shield is further adapted to prevent quantities of liberated gases from traveling toward the electrode and thereby interfering with the electrical current distribution. Further, the shield of the invention is adapted and located to allow free circulation of electrolyte, thereby avoiding localized heating in the region between the electrode and the workpiece. In a preferred embodiment the shield has a concave shape, the concavity being disposed toward the electrode, and the portion nearest the workpiece having the aperture. In a further preferred practice of the invention, thief portions are utilized on noncritical parts of the workpiece to further aid current distribution and the electrolyte is 10 volume percent HCl and water.
In contrast to much prior art wherein it is indicated that desired higher electrolyte temperatures are associated with higher efficiencies, in a preferred practice of the invention, the temperature of the electrolyte is maintained below 20° C. and even more preferably at about 7° C. In a preferred embodiment of the invention, the roughness of etched surfaces is controlled by variation of the electrolyte temperature. Lower temperatures are used to produce smoother surfaces; when higher roughness is desired, the electrolyte temperature is raised to 25° C. or higher.
Advantages of the invention are that disparate areas of superalloys can be etched to a precision heretofore difficult to achieve; depression depths may be made consistent in different areas of the workpiece even when grooves have different widths. Thus, manufacture of precision parts is greatly simplified. Furthermore, the surface finish of parts can be controlled without the necessity for secondary operations. This provides the opportunity for creating grooves and other etched depressions having different surface characteristics, e.g., varying fluid heat transfer rates. In addition, good rates of production are achievable and good efficiency of electrical utilization is achieved.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a general view of the apparatus for electrolytic etching.
FIG. 2 is a graphical representation of electrolytic etching parameters and the surface roughness obtained in grooves.
FIG. 3 is a planar view of grooves etched in the surface of a nickel superalloy workpiece.
FIG. 4 is a view similar to that of FIG. 3 but with etching parameters which provide less side etch.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As will be evident from the following discussion, the apparatus and method of the invention are applicable to various metal alloys and configurations. Nonetheless, the preferred embodiment is described in terms of electrolytically etching grooves of about 300 μm depth in a 1.5 mm thick by 25 mm wide by 100 mm long plate of nickel superalloys such as the commercial alloys IN-625, IN-600, IN-100 and MAR M-200.
FIG. 1 shows an apparatus for electrolytic etching according to the invention. A nonconductive and acid resistive vessel 20 of about two liter capacity is filled with liquid electrolyte to a level 22 near its top. The workpiece 24 rests on the bottom of the vessel and is connected to the power supply 26 by a conductor 28. The workpiece is coated with a resist 30, which by its absence in certain areas defines the pattern of uneven width but uniform depth grooves 32 which is sought on the workpiece. This pattern is more clearly shown in FIG. 4. The workpiece is disposed in the tank so that the surfaces to be etched are facing vertically up. An electrode 34 is mounted vertically above the workpiece at a distance of about 100 mm. The electrode, preferably made of a material such as platinized titanium mesh in a rectangular platelike shape, is connected to the power supply 26 by conductor 36. Interposed between the electrode and the workpiece is a shield 38, made of a nonconducting material such as a methacrylate thermoplastic. The shield is comprised of a base plate 40 inclined side plates 42 and 42' and vertical side plates 44 and 44', all the elements being integrally joined. The base plate and side plates define a concave shaped structure within which the electrode 34 is contained .The shield is supported in its fixed position by extensions of the plates 44 and 44' which rest on the bottom of the tank. Other obvious means could be used to support the shield. The base plate 40 contains an aperture 46 which is approximately centered above the workpiece at a distance of about 55 mm from it. It will be noted that the liquid level is above the top, or open concave end, of the shield. Nonetheless, the only direct path for current flowing between the electrode 34 and workpiece 24 is through the aperture 46.
Discussing now the general mode of operation of the apparatus, the vessel 20 is filled with an electrolyte. Electrolyte composition and concentration will vary with the metal being etched, according to well known art. For nickel superalloys, aqueous solutions of various acids, such as HCl and HNO 3 , and aqueous solutions of salts, such as NaCl, are usable. As noted below HCl is preferred. Before placing the workpiece in the electrolyte it is prepared in the following conventional manner: as necessary, degreasing is followed by other cleaning and drying steps to remove all contaminants; then a resist such as Waycoat S.C. Resist (Phillip A. Hunt Chemical Corporation, Palisades Park, N.J.), is applied to the surface of the workpiece and selectively removed, using common techniques and the manufacturer's instructions, to produce a workpiece wherein the areas which are to be etched are free from the resist. The workpiece is then connected with the conductor 28 and placed in position in the bottom of the vessel. The power supply 26 is a source of electric potential and current of sufficient capacity for the electrode workpiece distance, electrolyte, surface area being etched, and speed of removal which is sought. In the preferred practice of the invention described herein a power supply of 50 volts dc and 25 amperes capacity is adequate. The power supply also has the capability of periodically reversing the direction of the current flow. The workpiece is also optionally provided with integral thief portions 48 and 48'. These are areas free of resist which aid in balancing the distribution of current at the workpiece.
The operation of the apparatus will now be described specifically for the formation of grooves in a modified nickel alloy MAR M-200 which has the composition by weight percent of 9 chromium, 10 cobalt, 12 tungsten, 5 aluminum, 2 titanium, 2 hafnium, 1 columbium and balance nickel. The preferred electrolyte is a 10 volume percent HCl aqueous solution having a specific gravity of 1.047. The concentration of HCl may vary, at least over the range 8-12 percent. If a constant anodic potential is applied to the workpiece, insoluble products are formed on the surface. This is believed to be due to local chemical reactions of the following type:
(1) NI→Ni ++
(2) 2H 2 O→2OH - +O 2
(3) Ni ++ +2OH - →Ni(OH) 2
Thus, metal ions are dissolved (Equation 1); the production of a hydroxide ion due to the breakdown of water (Equation 2) raises the pH locally, which in turn results in the precipitation of metal hydroxides (Equation 3) which constitute the sludge. The precipitated hydroxides are not conductive and, being on the workpiece surfaces, will interfere with uniform etching. General uneveness and a ridge running down the length of a groove will result. To overcome this, the current is reversed, e.g., the workpiece is made cathodic periodically. This results in massive evolution of hydrogen at the workpiece which scrubs its surface and removes the insoluble material collected in the passages. Tests with MAR M-200 and the 10% HCl electrolyte have shown that the preferred workpiece potential versus time cycle comprises 2.5 seconds anodic alternated with 5 seconds cathodic.
As was indicated, a serious problem with electrolytic etching is the uneven milling which is caused by higher primary current densities at larger exposed areas, compared to smaller exposed areas, and at the edges of the workpiece. A common approach for balancing current densities is to use thieves, which are normally extraneous pieces of metal disposed around and electrically connected to the workpiece. Of course, the disadvantage of thieves is that they increase the total current which must be applied by the electrode, not only creating an inefficiency and unnecessary and undesirable heating of the electrolyte, but also at times exceeding the limits of the power supply. As is disclosed below, a combination of thieves and shield was found most suitable for the workpiece of the preferred embodiment. The approach was to use selected portions of the workpiece, e.g., surfaces on which dimensions are not critical, or surfaces on portions of the workpiece which can be discarded in subsequent fabrication.
Control of the variation in current density at the workpiece is quite critical to achieving uniform etching. The current density at a point on the workpiece is a function of primary current distribution, which is dependent on the general geometry of the apparatus, and the secondary current distribution which is related to local effects, such polarization. The shield 38 with its aperture 46 has a substantial effect on the current distribution at the workpiece. One concept is that since the current is forced to pass through the aperture 46, the aperture acts as a virtual electrode. Experiments with the particular workpiece described here have shown that an aperture of 5×8 mm is suitable. The exact aperture and lateral and vertical position with respect to the workpiece is subject to variation, according to the pattern of grooves which are being produced on the workpiece.
As was indicated, it is necessary to use periodically reversed current to eliminate the accumulation of sludge and other byproducts on the workpiece. This results in the evolution of substantial quantities of gases at the workpiece. The reason the workpiece is disposed with the etched surface facing vertically up is to allow the ready escape of these gases without having them interfere with etching as they might if they flowed transversely across the surface of the workpiece. In like fashion, passage of the gases towards the electrode from the workpiece results in gas polarization, that is, it will undesirably decrease the effective cross section of the electrical path between the electrode and workpiece. Therefore, the shield of the invention is shaped to contain and protect the electrode from the gases. Except for those gases which rise directly from the workpiece toward the aperture 46, gases will be intercepted by the shield and deflected laterally by its shape, whereupon they will continue to rise to be liberated at the surface of the electrolyte at the periphery of the shield.
In the description of the apparatus, it was stated that the shield was shaped and positioned within the electrolyte so that there was electrolyte above at least a portion of its open concave end or top. Current passing between the electrode and workpiece will naturally resistively heat the electrolyte and thereby undesirably alter the electrolytic etching conditions. To avoid this, the shield is shaped and positioned so that free circulation of electrolyte within the concavity of the shield is possible. Electrolyte which is heated within the shield will convectively rise to the top of the shield and pass over its edge, being replaced by the inflow of cooler electrolyte through the aperture. In the practice of the invention thus far, it has not been found necessary to use mechanical agitation, due to the convective circulation and activity of evolved gases. However, mechanical agitation could be used in other instances to enhance circulation of the electrolyte. Similarly, it will be apparent that other shapes of the shield than that described would be equally suited to protect the electrode-workpiece space from evolved workpiece gases and at the same time allow the free circulation of electrolyte.
A substantial and potentially useful effect of temperature of the electrolyte near the workpiece on the quality of grooves has been discovered. Heretofore, the general practice has been to operate at room temperature (20° C.) or higher, as the bath will naturally heat during etching. But, it was found that the temperature of the electrolyte affects both the roughness on the etched surface and the degree of side etch. Side etch is defined and quantified in a percent as: ##EQU1## And surface roughness is measured with a device, such as a profilometer; it is the relative change in surface height to the mean as a probe passes across the length of a surface. To evaluate the effects of temperature, grooves from about 0.5 to 2 mm wide were etched, in a pattern similar to that shown in FIGS. 3 and 4. Nominally, the same current and voltage were used. The test conditions used in evaluating the temperature effects are shown in Table I.
TABLE I______________________________________Effect of Electrolyte Temperature onAverage Groove Depth and Side EtchPotential Current Temp. Depth Side EtchVolts amp °C. 10.sup.-2 mm %______________________________________45 15 7 25.7 5145 15 16 30.5 6340 17 25 35.3 8337 17 41 32.0 181______________________________________
FIG. 2 indicates that temperatures lower than 20° C. substantially reduce surface roughness. It was found that the most preferred temperature for MAR M-200 is 7°±1° C. It can be seen further from the data in Table I that the percent side etch rises dramatically with increasing temperature. This effect of side etch is further illustrated in FIGS. 3 and 4 where the widths of grooves 32 produced in identical resist-coated workpieces are substantially reduced when the temperature is lowered from 41° C. to 7° C. A low percentage of side etch is indicative of a process capable of producing narrow grooves of greater depth to width ratio and less sidewall taper. Consequently, not only can finer grooves be manufactured, but less compensation need be made in the resist pattern to achieve a desired groove pattern in a finished article. Conventional means are usable for maintaining the temperature of the electrolyte within the desired range. These include cooling coils and recirculating pumps and heat exchangers.
Although this invention has been shown and described with respect to a preferred embodiment, it will be understood by those skilled in this art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention. | A method for electrolytically etching metals. Nickel superalloys are etched with uniform grooves using a 10 volume percent HCl aqueous solution and periodically reversed current. An aperture containing shield is interposed between an upward facing workpiece and an electrode. The shield is adapted to divert gases evolved at the workpiece from passage to electrode. Controlled roughness in an etched surface is produced by varying electrolyte temperature. Preferred smooth finish is obtained at 7° C. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to the United States design application that was filed concurrently herewith, bearing the title MEDICINE PORTFOLIO ORGANIZER, identified by attorney docket number 20064.1020 and filed under customer number 35856, which application is incorporated herein by reference in its entirety.
BACKGROUND
[0002] According to the Institute of Medicine's Jul. 20, 2006 report bearing the title of PREVENTING MEDICATION ERRORS: QUALITY CHASM SERIES”, it is estimated that in “any given week, four out of five adults in the United States will use prescription medicines, over-the-counter drugs, or dietary supplements of some sort, and nearly one-third of adults will take five or more different medications”. “Statistics prove prescription drugs are 16,400% more deadly than terrorists”. This was the title of an article published by Jessica Fraser on Jul. 5, 2005 on the NATRUALNEWS website which can be found at the URL of www<dot>naturalnews<dot>com. At the time the article was written, the author claimed that over 750,000 people die in the United States every year from conventional medicine mistakes with about 106,000 to 200,000 of these deaths being attributed to prescription drugs related issues. In the Institute of Medicine's Jul. 20, 2006 report, several reported statistics were provided with regards to adverse drug events (ADE) or injuries due to medication. For instance, between 380,000 to 450,000 ADEs were estimated to occur in hospitals but, the committed believed that these numbers were underestimates. The report stated that one study calculated that 800,000 preventable ADEs occure each year in long-term care facilities while another that among outpatient Medicare patients, over 530,000 preventable ADEs occur per year. These statistics are exacerbated by our “take a pill to cure the ill” culture combined with the pharmaceutical ads that flood into our homes on prime time TV.
[0003] An article by Michael A. Steinman, MD and Joshph T. Hanlon, PharmD, MS bearing the title MANAGING MEDICATIONS IN CLINICALLY COMPLEX ELDERS “THERE'S GOT TO BE A HAPPY MEDIUM” highlights the risks and issues involved in ADEs related to elderly patients having multiple medications. The article further addresses the issue by posing several needs in the art. First, a systematic approach to approaching prescribing is essential. Second, an essential first step is to know what the patient is actually taking right now, and to clarify what goals you are trying to achieve by prescribing drugs. Third, it is critical to individualize care based on what benefits and harms a patient is actually experiencing from their drugs.
[0004] “Medication Non-Compliance Estimated to Result in More Than 300,000 Deaths Each Year” was the title of an article posed by Kathy Wetters on Oct. 17, 2010 on the RIGHT AT HOME website. In this article, Ms. Wetters states “Medication non-compliance is becoming one of the most expensive and deadly problems in healthcare today. Hospital costs due to patient non-compliance are estimated at $8.5 billion annually. And with more than 300,000 deaths annually resulting from non-compliance, healthcare professionals, caregivers and Americans are left searching for new ways to fight this avoidable issue”.
[0005] In an article published by FierceHealthcare bearing the title of PATIENTS NOT TAKING MEDICATIONS COST $300B, May 27, 2011 it is stated that the lack of prescription medication adherence costs between $250 and $300 billion annually. Supporting this position, the article cites a report from Express Scripts' released in April of 2011 determining that patients not taking their precribeed medications costs roughly $259 billion per year in emergency room and docober visits, as well as inpatient hospitalizations.
[0006] The website www<dot>abovetheinfluence<dot>com is a web campaign sponsored by the National Youth Anti-Drug Media Campaign and is directed to provide information about drug abuse, overdosing, and non-compliance. With regards to prescription drugs, ABOVETHEINFLUENCE writes:
[0007] “Prescription drugs are medicines that are prescribed to a patient by a doctor to manage pain, treat or cure a health condition such as pain, mental disease, diabetes, cancer, or common infections. These drugs are regulated by the Food and Drug Administration (FDA) and are shown to have medical benefits when prescribed and taken exactly as directed by a health provider. For people who are suffering, these drugs allow them to control their symptoms, cure or treat their diseases, control pain, or fight an infection. However, these medicines are only safe when taken exactly as directed by a doctor, healthcare provider, or as indicated on the packaging. This includes following directions on dosages, how often to take these drugs, and never taking any drug that is not prescribed for you.”
[0008] “Taking prescription drugs that are not prescribed to you—or taking them in any way other than directed by a doctor—is considered non-medical use or abuse and can be as dangerous as taking an illegal drug, such as cocaine or heroin. “Misuse” of a prescription drug is taking it to treat a medical condition but not as directed by a doctor or packaging; “abuse” is taking prescription drugs with the sole intention of getting high. When misused or abused, many prescription drugs can be as dangerous and addictive as “street” drugs. In recent years, there has been a dramatic increase in the number of poisonings and even deaths associated with the abuse and misuse of prescription drugs, including prescription painkillers and anti-depressants.”
[0009] “In other words, even if a medication is prescribed to you, taking larger doses than prescribed, taking it more often than directed, or using it in a way that it is not intended, is abuse and can also lead to severe health consequences and addiction. Between 1995 and 2005, treatment admissions for dependence on prescription pain relievers such as oxycodone (OxyContin) and hydrocodone/acetaminophen (Vicodin) grew more than 300 percent.”
[0010] “Taking prescription drugs without a prescription, not taking them as directed, or mixing them with alcohol are all unsafe and potentially deadly. A 2008 study based on 224,355 U.S. death certificates for which people died from medication errors showed that there was a 3,196 percent increase between 1983 and 2004 in deaths at home from combining prescription drugs with alcohol and/or street drugs.”
[0011] “Additionally, getting prescription drugs without a prescription, called “diversion” is illegal and may put you at risk for arrest and prosecution. Regardless of how you acquire a prescription medication, using these types of drugs without a valid prescription—written for you—is unsafe and illegal.”
[0012] The term “noncompliance” is used in medicine particularly in regard to a patient not taking a prescribed medication or following a prescribed course of therapy. For example, “As many as half of ‘failures’ of treatment to bring elevated blood pressure down to normal levels may be due to unrecognized lapses in taking antihypertensive drugs as prescribed, according to a new study by a team of researchers from the University of Lausannne, Switzerland.” (Stephenson J, JAMA 282: 313, 1999)
[0013] Noncompliance may be overt (as with a Christian Scientist who rejects recommended therapy for religious reasons) or covert (as with children who are supposed to take an antibiotic, say they are taking it but are not, as revealed by a blood test to detect that antibiotic).
[0014] For some individuals, the number of medications that they must take can be overwhelming. Having multiple prescriptions with varying dosage schedules and amounts can become confusing. This, coupled by the similarity in the bottles and labeling, the non-descriptive naming conventions, busy schedules, etc., can easily lead to innocent mistakes by an individual that is taking the medicine—innocent mistakes that can be fatal.
[0015] Whether the cause of non-compliance is due to misuse, abuse, diversion or simply human error, it is clear that the problem is epidemic. Thus, there is a need in the art for a system to help reduce medicine non-compliance.
BRIEF SUMMARY
[0016] Various embodiments disclosed provide a tool, system, method and/or device to help organize and manage the storage, access and administration of prescription and/or over-the-counter medications. In general, a portfolio that includes various storage mechanism, holders and tools that can be used for managing a patient's medications. More specifically, in one embodiment, the portfolio is a two-sided brief-case like device that can be secured in a closed position, or opened to gain access to the interior of the portfolio. The portfolio may include multiple pockets on the outside for storing various items, and a variety of pockets, sleeves, receptors and Velcro or hook and loop structures for receiving and holding various elements such as a pill dispenser, containers, pill bottles, etc. In some embodiments, the portfolio is sold in a particular configuration and/or various versions may include different configurations. In other embodiments, the portfolio may be user configurable by including an interior that includes Velcro or hook and loop surfaces that can receive and securely hold various elements, such as medicine bottle receptors, pockets, sleeves, pill dispensers, communication devices, pouches, etc.
[0017] A particular embodiment includes a portfolio for holding medicine and medicine related items. The portfolio includes a first side and a second side. The first side is joined along one edge with the second side. The joint between the first and second side is flexible or hinged, thereby allowing the first side and the second side to be moved in a hinged like fashion away from each other to an open position and towards each other to a closed position. The one or more of the sides includes a plurality of receptors with each receptor configured to receive a pill bottle. One or more of the sides include at least one pocket for holding a notepad; a surface for receiving and holding pill dispenser; and a calendar. A latching mechanism may be included for securing the first side to the second side in the closed position.
[0018] In various embodiments, the first side and the second side may include interior surfaces with at least portions of the interior surfaces including a fastening element for receiving one or more elements. For instance, the fastening element may be Velcro, hook and loop, snaps, buttons, adhesive, loops, buttons, or other fasteners. The received one or more elements include a mating fastening element. For instance, if the fastening element is Velcro hooks, the mating fastening element may be Velcro loops, etc. As an example, the receptor strips may include the mating fastening element and can be secured to the interior surface of the first or second side. Further, one or more of the elements of a receptor strip, a pocket for holding a notepad; a pill dispenser; a note pad, a calendar, a pouch, a communication device, and a writing instrument may include a mating fastening element that can be secured to the interior surface of the first or second side.
[0019] In other embodiments, the plurality of receptor strips may be fixedly secured to the interior surface of the first or second side. Likewise, one or more of the elements of a receptor strip, a pocket for holding a notepad; a fastening element for a pill dispenser; a note pad holder, a calendar holder, a pouch holder, a communication device holder, and a writing instrument holder can be fixedly secured to the interior surface of the first or second side.
[0020] Further, in other embodiments, a combination of removably attached elements and fixedly attached elements may be utilized in the portfolio.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0021] FIG. 1 is a perspective view of one embodiment of the medication storage and organizer in the form of a portfolio.
[0022] FIG. 2 is a perspective view of the inside of an exemplary embodiment of the portfolio.
[0023] FIG. 3 is a perspective view of an open and populated portfolio in accordance with one embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0024] The present disclosure presents a tool, system and method to help reduce medicine non-compliance by, as well as features and aspects thereof, is directed towards providing an organizer that assists individuals in organizing, identifying and tracking their use, storage and dosing of prescription and over-the-counter medications.
[0025] The disclosed embodiments may include functional elements for the storage of prescription and over-the-counter medications (collectively referred to as medications) and a method for clearly labeling and organizing the medications. Further, the disclosed embodiments may include a dosage tracking functional element for sorting, tracking and verifying medication dosages. Even further, various embodiments may include additional functional elements including, but not limited to, a one or more notepads for writing notes, cautions, instructions, questions/concerns to bring to the attention of the individual's physician, etc., a writing utensil storage element, a calendar, an electronic media and storage receptacle for the same that can contain further information such as instructions, warnings, etc., a calculator for converting measuring units, a dispenser for measuring dosages, a cutter for splitting pills.
[0026] Turning now to the drawings in which like labels represent like elements, various embodiments of medication storage and organizer are presented.
[0027] FIG. 1 is a perspective view of one embodiment of the medication storage and organizer in the form of a portfolio. The portfolio 100 is shown as including a zipper 102 that can be actuated to securely close the portfolio or open the portfolio to allow access to the inside of the portfolio. It will be appreciated that the zipper 102 may include a locking mechanism to prevent unauthorized access. The locking mechanism can be a simple mechanical combination lock, a keyed lock, an electronic lock, etc. It will also be appreciated that the portfolio can be closed using a variety of techniques including snaps, Velcro, straps, buckles, magnets, covering sleeve, or the like, as well as combinations of two or more of these techniques.
[0028] In the illustrated embodiment, the portfolio is shown as including two external pockets 104 and an identification tag 106 . The external pockets 104 can be used for storage of a variety of items including as non-limiting examples, instructions, books, journals, insurance information, insurance cards, prescription cards, HMA cards, etc. Although only two external pockets are illustrated, it should be appreciated that more or fewer pockets can be used in various embodiments. The identification tag 106 allows for the ownership and contact information of the portfolio to be readily accessible and identified without having to gain access to the internal portions of the portfolio. In the illustrated embodiment, the identification tag 106 is illustrated as a card that can receive the owner's name, address and telephone number. However, it will be appreciated that additional or less information can also be provided. In addition, other forms of an identification tag may also be employed, such as an electronic display.
[0029] FIG. 2 is a perspective view of the inside of an exemplary embodiment of the portfolio. The portfolio 100 is shown as including a top or back section 210 , and a bottom or front section 230 . The top section 210 is connected to the bottom section 230 along a single side using a flexible material or a hinge or a hinging structure. The connection between the top section 210 and the bottom section 230 enables the top section 210 to be moved away from the bottom section 230 into an opened position, or moved towards the bottom section 230 to a closed position. The top section 210 is shown as including multiple storage receptors 214 arranged in three receptor rows 212 of seven receptors 214 each. In addition, the illustrated embodiment includes a general receptor 216 . The receptors 214 may be suitable for receiving and holding a standard pill bottle. The illustrated receptors 214 are shown as being uniform in size and constructed using an elastic band that is tacked to the surface of the top section 210 at periodic intervals to form receptor loops for receiving the pill bottles. The receptor loops can be constructed at a single size that may accommodate small, medium and large pill bottles. However, in some embodiments, different loop sizes may be utilized and intermixed throughout the portfolio. For instance, some pill bottles may be extra large and require a larger receptor loop which would not be able to accommodate or securely hold smaller pill bottles. In addition, a variety of other mechanisms may be used for holding and securing the pill bottles, as well as other elements in the portfolio. For instance, a plurality of clips, similar to the clips used on the bottom of TV trays, microphone holding clips, etc. can be fixedly or removably attached to the interior surface of the portfolio. In such embodiments, the pill bottle can be pressed into or slid into the holding clip and secured in place. In addition, holders similar to those used for batteries can be used for receiving the pill bottles.
[0030] The general receptor 216 can be used for storage of a writing instrument, a tool such as a pill cutter, a dosage measuring device, or the like. It should be appreciated that the illustrated configuration is simply one of a variety of configurations that may be implemented in various embodiments. Some embodiments may use more or fewer medicine bottle receptors 214 and more or fewer general receptors 216 .
[0031] The bottom section 230 is illustrated as including multiple regions for housing various functional components. In the illustrated embodiment, the bottom section 230 includes a Velcro fastener for a pill box 232 , a pocket or flap for receiving a calendar 234 , a pocket or flap for receiving a note pad, a Velcro fastener for receiving a detachable pouch or container, and a pocket or flap 240 for receiving and holding another note pad, a calculator, insurance card, etc.
[0032] The top section 210 and the bottom section 230 each are bordered by a flap 218 and 242 such that the flap of the top section 210 mates with the flap of the bottom section 230 to close the portfolio. As previously presented, the flaps may include a zipper to secure the flaps together as well as other mechanisms. The flaps 218 and 242 can be constructed in a variety of manners. As non-limiting examples, the flaps may be (a) flexible to allow them to be pulled back over the top section 210 or bottom section 230 to aid in accessing the portfolio contents or (b) rigid to ensure protection of the portfolio contents and to help prevent items from falling out of an opened portfolio.
[0033] FIG. 3 is a perspective view of an open and populated portfolio in accordance with one embodiment. The portfolio 100 is shown as including a top or back section 210 , and a bottom or front section 230 . The top section 210 is shown as including multiple storage receptors 214 arranged in three receptor rows 212 of seven receptors 214 each. Each of the receptors 214 is illustrated as being populated with a medicine bottle 314 . In the illustrated embodiment, attachable labels are presented for identifying the type of medication that is stored in a particular receptor 214 . In the illustrated embodiment, the label includes a Velcro strip 310 that can be looped through the receptor strap 214 . The Velcro strip 310 includes a label holder 312 and a label 316 that can be placed into the label holder 312 . It should be appreciated that labels could be included using a variety of other techniques. A few non-limiting examples include a label with a clip, a label holder fixedly attached to the receptors 214 , a dry-erase type material fixedly attached to the receptor 214 or above/below the receptor 214 in such a manner that the medicine bottle would not obstruct its view, labels that can be attached directly to the bottles (either the side, top or bottom), etc.
[0034] In addition, the illustrated embodiment includes one or more general receptors 216 . In the illustrated embodiment, a pen is shown as being inserted into the general receptor 216 . In other embodiments, various tools or other devices can also be accommodated. For instance, a general receptor could be used to hold a cellular telephone, a pager, a personal data assistant (PDA), a notebook computer, an iPad, and/or an emergency transmitter (such as the “I have fallen and I can't get up” medical alert device), measuring tool, pill cutter, etc.
[0035] The bottom section 230 is illustrated as housing a note pad for listing medication and/or instructions 336 , a pocket for holding a flash drive or memory device, a note pad for writing questions to be asked during a next visit to the doctor or pharmacy, a pill dispenser box including compartments for morning and evening of each day of the week 332 and a calendar 334 . In the illustrated embodiment, the two note pads 336 and 340 and the calendar are held in pockets 236 , 240 and 234 respectively (see FIG. 2 ). The pill dispenser 338 and the pouch 338 are secured into position by including mating Velcro on the underside of the pill dispenser and pouch.
[0036] In should be appreciated that in varying embodiments, the elements may be permanently secured or detachable as described.
[0037] In another embodiment of the portfolio, the interior may be fully customizable. This can be accomplished using a variety of techniques. For instance, the entire interior surface may include a hook and loop fastening material. In such embodiments, a portfolio may be sold with a general set of attachments and other attachments or options can be purchased and added separately. For instance, various receptor rows 212 may be included with the portfolio with the underside of the receptor row including a mating hook and loop material. Advantageously, in such a configuration the user can include various rows for various needs. As an example, each receptor row 212 may include various receptor sizes. In some embodiments, each row may focus on a particular receptor size while in other embodiments, receptor rows may include a variety of different receptor sizes. Similarly, the portfolio may be sold with a variety of other elements/devices such as a calendar, a variety of notepads, one or more pockets of varying sizes, one or more pill dispensers, a calculator, etc.
[0038] In another embodiment, rather than a folding portfolio, the portfolio may consist of a single tray and a sleeve that slides over the tray. In operation, the tray may be pulled or slid out of the sleeve to provide access to the interior of the portfolio. The sleeve can be open on two sides to allow the tray to be slid out in either direction or, the sleeve can include only a single opening on one side. In yet other embodiments the tray may include a top, similar to a cigar box, to allow access to the interior of the trey. In some embodiments, the portfolio may resemble a briefcase or a satchel with a carrying handle. In some embodiments, the portfolio may open as presented in FIGS. 1-3 , but also include a quick access door located over the pill dispenser box to allow ease of access to the pill dispenser box. Similarly, the portfolio may include a drawer that can be pulled open to provide access to the pill dispenser or other elements in the portfolio without requiring the entire portfolio to be opened.
[0039] In some embodiments, the portfolio may include an embedded processor that can be programmed for providing alerts to the user regarding when medications should be taken. In such an embodiment, the processor may include an interface to a computing system for providing such programming. The interface may be a wired or wireless interface, such a WIFI, Bluetooth, etc. An LCD or other type display may be included to provide instructions to the user, such as reminders to take a dosage of medicine, to call in for refills, or the like.
[0040] The portfolio can be constructed from a variety of materials. As non-limiting examples, the portfolio may be constructed of plastic, aluminum, silicone, cloth, GORE TEX, plastic with a cloth covering, as well as combinations or hybrids of any of these materials as well as other materials.
[0041] In some embodiments, the portfolio is constructed to be water proof or water resistant. In other embodiments, the portfolio is designed to easily slide into a refrigerator. In yet other embodiments, the portfolio may include one or more water proof pockets for holding BLUE ICE or similar devices that can be used to maintain the temperature within the portfolio at a particular temperature. In other embodiments, the portfolio may include insulation or a thermal protection. Alternatively, only portions, pockets, or sections of the portfolio may include insulation or thermal protection. Advantageously, such embodiments allow the portfolio to be portable even for medications that require refrigeration.
[0042] Some embodiments of the portfolio may include a pocket, sleeve or chamber for holding a thermos or water bottle.
[0043] In the description and claims of the present application, each of the verbs, “comprise”, “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements, or parts of the subject or subjects of the verb.
[0044] The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art. Further, the drawings and description has shown various elements being attached or affixed to certain areas and certain sides of the portfolio, but it should be appreciated that a variety of configurations may be employed such that any of the described elements can be placed at any location on any side of the porfolio's interior or exterior.
[0045] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein above. Rather the scope of the invention is defined by the claims that follow. | A portfolio for organizing and managing the storage, access and administration of prescription and/or over-the-counter medications. The portfolio that includes various storage mechanism, holders and tools that can be used for managing a patient's medications. The portfolio is a two-sided brief-case like device that can be secured in a closed position, or opened to gain access to the interior of the portfolio. The portfolio may include multiple pockets on the outside for storing various items, and a variety of pockets, sleeves, receptors and Velcro or hook and loop structures for receiving and holding various elements such as a pill dispenser, containers, pill bottles, etc. The portfolio can be pre-configured or configurable by including an interior that includes Velcro or hook and loop surfaces that can receive and securely hold various elements, such as medicine bottle receptors, pockets, sleeves, pill dispensers, communication devices, pouches, etc. | 0 |
This invention relates to closed die metal forging in general, and specifically to a method of forging an apertured part in one cycle, without a separate piercing step.
BACKGROUND OF THE INVENTION
Closed die metal forging, sometimes referred to as impact machining, has been used for some time as an alternative to more expensive machining techniques. A known apparatus and method are described in detail in U.S. Pat. No. 4,796,459 to Mueller et al, which is assigned to the assignee of the subject invention. Through the use of dies that are forced together under great pressure, quite complex parts, such as toothed gears, can be forged without grinding or machining the teeth. A pair of die supports carry mating cavities that match the desired part shape. When closed together, a metal blank is pressed out, closely filling the mated cavities to create the part. In order to accommodate the extremely high pressures involved, the forging apparatus disclosed in the patent backs the die supports with hydraulic oil chambers formed in a movable upper ram and a fixed lower bolster. A special fluid accumulator and pressure intensifier system is used to control and tailor the fluid pressure in the chambers throughout the forming process. As the die supports initially close, the pressure in the chambers is kept lower to cushion the impact and reduce noise. As the blank begins to be pressed into shape, and the die separation forces consequently rise, the pressure in the chambers is allowed to rise so as to prevent die separation.
When the part formed has a central aperture, such as a pinion gear for a vehicle differential, a pair of coaxial punches is used to partially form the aperture. Each punch is rigidly fixed to a respective ram and bolster, and each die support slides over a punch as it is compressed back into its respective chamber, like a piston. Each die support moves back substantially the same distance as the other, since the pressure backing them is kept substantially constant. In fact, it is the rigid punches that actually apply the force that extrudes the blank out into the mated cavities. A shortcoming of this system is that the punches cannot form a complete aperture. The ends of the punches come close together under great force, but, inevitably, there is a slug of metal left between them. After the part is removed, the slug is punched out in a separate, subsequent step. It would save considerable time and cost if the slug did not have to be removed separately.
SUMMARY OF THE INVENTION
The invention provides a novel method of using the type of apparatus described, which forms the entire part in one cycle.
In the method of the invention, instead of maintaining the pressure behind the die supports equal with a single accumulator and intensifier system, separate, dedicated systems are used to control the pressure behind each die support individually. At the beginning of the cycle, when the die supports first meet, the pressure in the ram chamber is kept very high, while that in bolster chamber is kept low. Therefore, as the ram and bolster move together, the die supports do not move back within their respective chambers equally. Instead, the upper die support moves one-to-one with the ram and upper punch, pushing the lower die support down, which slides down over its punch as fluid is forced out of the lower chamber. As this occurs, the pressure in the upper chamber is maintained, while the expelled fluid from the lower chamber is accumulated and intensified to a higher, intermediate pressure. The intermediate pressure is kept deliberately lower than the upper chamber pressure, however, so that the unequal die support motion is maintained.
At the end of the down stroke, called bottom dead center, the part is fully formed, but for the slug left between the ends of the punches. Next, the fluid in the ram chamber is quickly exhausted, while the accumulated fluid from the bolster chamber is allowed to rush back in. Now, the pressure differential is allowed to equalize, and the lower die support pushes the upper one up as they slide up together over the coaxial punches. As this occurs, the blank is sheared out of the aperture. Finally, the die supports can be parted, and the part and sheared slug removed.
It is, therefore, a general object of the invention to close die forge an apertured part in one press cycle, with no subsequent slug removal operation.
It is another object of the invention to provide a new way of using a known closed die forging apparatus to achieve one-cycle operation.
It is another object of the invention to use the known apparatus with separate, dedicated fluid pressure control systems to create a differential sliding action between the fixed punches and the sliding die supports that will shear off the slug at the end of the press cycle.
It is still another object of the invention to use the dedicated pressure control systems to initially maintain the ram chamber pressure very high and the bolster chamber pressure very low, thereby forcing the bolster die support down with the ram die support while accumulating the fluid expelled from the bolster chamber at a higher intermediate pressure, then exhausting the pressure from the ram chamber and allowing the accumulated fluid to re-enter the bolster chamber, thereby forcing both die supports to slide up together over the punches and shear out the slug.
DESCRIPTION OF THE PREFERRED EMBODIMENT
These and other objects and features of the invention will appear from the following written description, and from the drawings, in which:
FIG. 1 is a partially schematic view of the apparatus used to practice the invention, showing a portion of the ram and bolster in cross section and showing the punches in elevation;
FIG. 2 is part of the apparatus from FIG. 1, showing the die supports at the point of first contact, before the ram and bolster have fully closed;
FIG. 3 shows the ram and bolster fully closed, with the metal blank fully extruded;
FIG. 4 shows the slug sheared off after the die supports have moved up together over the punches;
FIG. 5 shows the ram and bolster reopened to allow part removal.
Referring first to FIG. 1, much of the apparatus used to practice the method of the invention is common to that shown in the patent noted above, but is used in a new way. The common hardware includes a movable upper ram, indicated generally at (10), and a stationary lower bolster, indicated generally at (12). The terminology ram and bolster is arbitrary, and either one, or both, could theoretically move. It is customary for the upper ram (10) to move and for the lower bolster (12) to be stationary, however. Both the ram (10) and bolster (12) are bored out to slidably receive coaxial cylindrical die supports, an upper, ram die support (14) and lower, bolster die support (16). By "die support", it is meant that the members support the matching upper and lower cavities (18) and (20) that together provide all of the part form, but for the aperture. In practice, the die supports (14) and (16) carry separate, removable dies in which the cavities would actually be cut. It is simpler here to depict the die supports and cavities as integral, however. The bore behind each die support (14) and (16) forms a cylindrical, hydraulic fluid filled chamber (22) and (24) respectively, which change in volume as the die supports (14) and (16) slide back and forth in piston like fashion. When the ram (10) and bolster (12) are open, each die support (14) and (16) extends out of its respective chamber (22) and (24) to the greatest degree, and the volume of fluid behind them is therefore largest. Fixed to the ram (10) and bolster (12) are coaxial upper and lower punches (26) and (28), which extend slidably through the die supports (14) and (16) and out of the cavities (18) and (20) respectively. Surrounding the bolster punch (28) is a slidable part knock-out sleeve (30).
Still referring to FIG. 1, separate, dedicated systems are used to control the fluid pressure behind each die support (14) and (16). The bolster chamber (24) is ported to an accumulator/ intensifier system like that described in the patent referred to above, and indicated generally at (32). System (32) has the ability to accumulate hydraulic fluid expelled from bolster chamber (24) and maintain it at a first, higher pressure, and then quickly raise and intensify the pressure to a new, much higher value. In the apparatus described in the patent noted, the two-level pressure capability is used to cushion initial closing impact, and then to prevent die separation throughout the rest of the cycle. Here, that same function is provided and, in addition, system (32) cooperates with a novel pressure control system linked to ram chamber (22) to provide a new function. The separate hydraulic fluid control system linked to ram chamber (22) comprises a high pressure pump (34), an accumulator (36) and one-way check valve (38), to feed fluid into ram chamber (22) through one line (40) from a reservoir (42), and an on-off control valve (44), which lets fluid out of ram chamber (22) to reservoir (42) through another line (46). These separate systems allow the apparatus described to produce an apertured part by the new method described next.
Referring again to FIG. 1, the ram (10) is at its highest point in the cycle, referred to as top dead center. Before the ram (10) is moved, a cylindrical blank (48) of metal is placed into the bolster cavity (20), as shown. The bolster punch (28) is initially oriented lower within its cavity (20), so as to hold the blank (48) easily. At this point, the ram chamber (22) is brought to a predetermined high pressure, somewhere in the range of 2,000 to 2,500 p.s.i., for example. The pressure necessary would be determined based on the pressure calculated to be necessary to extrude blank (48), based on the type of metal involved. Pressurization is accomplished by pump (34) drawing hydraulic fluid from reservoir (42) and pumping it through line (40) into ram chamber (22). Check valve (38) prevents back flow through line (40), and accumulator (36) stores the fluid under pressure so that a sufficient supply of high pressure fluid can be supplied to ram chamber (22) in a short time. The control valve (44) is closed to prevent back flow through line (46). Nonillustrated stop members prevent the ram die support (14) from being expelled. The bolster chamber (24) is at a far lower pressure initially, in the range of only 20 p.s.i., for example.
Referring next to FIGS. 2 and 3, the ram (10) and bolster (12) are next moved partially together, until the die supports (14) and (16) make contact, as shown in FIG. 2. This mates the two cavities (18) and (20). The ends of the coaxial punches (26) and (28) just touch the ends of the cylindrical blank, but no extrusion of metal has yet occurred. The ram (10) is not physically stopped at the FIG. 2 die contact point, but continues to fall in a continuous motion. At and after the FIG. 2 point in the cycle, the pressure in ram chamber (22) is maintained by the check valve (38) and control valve (44). Because it is backed by a much higher pressure, ram die support (14) moves rigidly, one-to-one, with the ram (10), and does not slide over the ram punch (26). It overpowers the bolster die support (16), which is pushed down, sliding over bolster punch (28) and collapsing the bolster chamber (24). Lower pressure hydraulic fluid is forced out of bolster chamber (24), and the force of impact at the die contact point is thereby cushioned. Simultaneously, as ram (10) moves down, the ends of the coaxial punches move together, compressing the blank (48) and forcing it out into the shape of the mated cavities (18) and (20).
Referring next to FIG. 3, the ram (10) has moved all the way down to close with bolster (12), the so called bottom dead center position. The metal blank (48) has become a partially complete part (50). A central, cylindrical aperture has been substantially formed in (50) by the punches (26) and (28), complete but for a thin slug (52) between them. The contact line between the die supports (14) and (16) is below the contact line between the ram (10) and bolster (12), and most of the hydraulic fluid in bolster chamber (24) has been forced out, which is no longer at its initial low pressure. The accumulator/intensifier system (32), working as described in the patent referred to above, has raised its pressure to a higher intermediate pressure that is closer to, but still less than, ram chamber (22), 1,700 to 1,800 p.s.i., for example. The combined pressures forcing the die supports (14) and (16) together is more than enough to overcome the extrusion force attempting to force them apart, as in a conventional forging operation. However, the differential in pressures that causes the asymmetric motion of the die supports (14) and (16) is used to provide an additional function, described next.
Referring next to FIGS. 3 through 5, the final steps in the process are illustrated. At bottom dead center, control valve (44) is opened to allow ram chamber (22) to quickly exhaust through line (46) back to reservoir (42). Simultaneously, the pressurized fluid accumulated in accumulator/intensifier system (32) is allowed to quickly rush back into bolster chamber (24), expanding it. The pressures in the chambers (22) and (24) quickly reach an equilibrium of around 20 p.s.i. As shown in FIG. 4, this quick pressure equalization forces the mated die supports (14) and (16) quickly up, which slide over and are guided by the coaxial, stationary punches (26) and (28). The mated die supports (14) and (16) reverse position, in effect and the contact line between them now moves above the ram (10)-bolster (12) contact line. The result of the quick and forceful reversed relative motion between the die supports (14) and (16) and fixed punches (26) and (28) is that the slug (52) is sheared off and left behind, creating a complete, apertured part (54). Finally, the ram (10) is moved back to top dead center position, as shown in FIG. 5. The completed part (54) can be pulled out of the ram cavity, and knockout sleeve (30) is raised to push the now sheared off slug (52) up for easy removal.
Thus, one-press cycle is all that is needed to form the completed part (54). The shearing of slug (52) is achieved only at the cost of the additional pressure control system for ram chamber (22). The elimination of the punch and the extra operation to remove slug (52) can represent a substantial savings per part. It should be kept in mind that it is the relative, reversed sliding motion between the fixed punches and the movable die supports, caused by the quickly removed relative pressure differential between the fluid chambers, that gives the shearing action. Therefore, it is arbitrary which die support is upper or lower, which chamber is initially the higher pressure chamber, or whether the ram or bolster is fixed or movable relative to ground. That is, the pressure differential could be switched, with the bolster punch (28) initially high within its cavity (20) and the ram punch (26) initially withdrawn up into its cavity (18). Then, when allowed to equalize, the slidable die supports (14) and (16) would be pushed up, not down, until they were even with the ends of the fixed punches (26) and (28), then they would travel back down, rather than up, to create the shearing action. Theoretically, to create the same shearing action, the punches could be made movable, relative to ram and bolster, and the die supports fixed. But that is impractical, because it is the pressure differential in the chambers, acting on the piston like die supports, that is best used to create the relative shearing motion. The pressure differential in the chambers behind the die supports that creates the relative sliding motion could be created by other means. For example, very high capacity, very fast acting pumps could, on demand, keep one chamber at high pressure and the other at low pressure until bottom dead center was reached, then reverse the pressure differential between the two chambers, as opposed to just allowing the pressure differential to equalize. This would provide the same relative shearing motion, without the various accumulators and valves disclosed. The pressure control systems and schemes disclosed are particularly useful, however, as they make at least partial use of know apparatus. Therefore, it will be understood that it is not intended to limit the invention to just the embodiment disclosed. | An apertured part is pressed in a single cycle with no separate slug shearing operation. The press ram and bolster each contain fixed aperture forming punches which extend coaxially and slidably through piston like die supports, each of which is backed by a hydraulic fluid chamber. Separate systems control the fluid pressure in the two chambers so as to cause the dies supports to slide in one direction relative to the punches initially, then quickly in the other direction to shear the slug formed between the ends of the punches away from the part. The ram chamber is maintained at a high pressure throughout the first half of the stroke, while the bolster chamber begins at a low pressure and is allowed to rise to a higher, intermediate pressure that is still lower than the bolster chamber. Thus, the ram die support pushes the bolster die support down. However, when the pressure differential is removed, the two die supports quickly move up together over the fixed punches, shearing the slug out of the part. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to an improved boom assembly for supporting a tool for conditioning metals and the like within a high temperature furnace.
Many of the newer furnaces now being introduced for use in reclaiming metals from scrap material utilize relatively large melting beds. Typically the scrap material is randomly deposited in the melting bed where it is exposed to very high melting temperatures. As the material begins to melt, it is very important to more evenly distribute the materials in the bed in order to provide for a more efficient operation. Once melted, any slag that might have formed on the surface of the liquid is skimmed off prior to pouring the metal from the furnace. A single rake-like tool, which is herein referred to as a conditioning tool, is usually employed to carry out both the skimming and material handling functions.
As best illustrated in U.S. Pat. Nos. 943,591, 3,800,965 and 3,931,898, extendable boom assemblies for supporting conditioning tools have been used for quite some time in the art. Typically, the boom is telescoped within some type of horizontally aligned support structure and is adapted to be run out from the support to increase the reach of the conditioning equipment. There is, however, no provision made in any of the prior art devices for cooling either the boom or the tool contained therein. As a consequence, the usable life of the equipment in a high temperature environment must be relatively short. It is further believed that without some form of cooling, the unsupported end of a boom of any considerable length will in a short period of time warp or sag when exposed to high furnace temperatures whereupon the boom might become lodged in the furnace and thus difficult to remove without damaging the furnace structure.
Hand-held tools, as typically used to skim slag from small melting furnaces, are sometimes furnished with cooling means to protect both the user and the equipment from becoming overheated. As evidenced in the disclosure in U.S. Pat. Nos. 1,827,504 and 2,198,649, a water jacket is generally formed inside the handle and/or blade of the skimmer and cooling water from a remote source is pumped therethrough to furnish the desired cooling. An extensive amount of hose is needed to supply water to the apparatus, particularly where it is used to service more than one furnace. This hose presents a problem in that it can be severed easily and has a way of becoming fouled in other equipment. Similarly, the use of water as a coolant considerably increases the weight of the equipment and, in the case of an elongated boom or the like, would be prohibitive. Furthermore, the use of water as a coolant is generally limited to low temperature applications. When water is exposed to very high temperatures it can quickly flash to steam, thereby giving rise to all the well-known problems associated with handling this relatively dangerous substance.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to improve equipment for supporting and manipulating a conditioning tool within a high temperature furnace.
Another object of the present invention is to provide an air-cooled boom of considerable length for supporting a conditioning tool so that it can be safely and effectively moved into and out of a high temperature furnace.
Yet another object of the present invention is to provide a relatively lightweight boom for supporting a conditioning tool that is of considerable length and which will not be thermally damaged when exposed to high furnace temperatures.
A further object of the present invention is to extend the usable life of equipment used to condition materials in high temperature furnaces.
These and other objects of the present invention are attained by means of an elongated boom that is adapted to support a conditioning tool in one end thereof and which is supported at the opposite end in a carriage mounted upon rails within a horizontally aligned gantry whereby the tool is able to be moved into and out of a furnace. Internal air passages are provided in the boom for directing a flow of cooling air therethrough to cool the parts of the boom and the tool exposed to the high furnace temperatures. A blower is mounted upon the carriage and is arranged to pump ambient air through the air passages to furnish the necessary cooling.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of these and other objects of the present invention, reference is had to the following detailed description of the invention which is to be read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a mobile machine embodying the teachings of the present invention which includes an elongated air-cooled boom that is adapted to move a conditioning tool into and out of a high temperature furnace;
FIG. 2 is a side elevation of the machine shown in FIG. 1 further illustrating the boom being extended into a high temperature furnace for reclaiming scrap material;
FIG. 3 is an enlarged side view showing the back end of the boom secured to a carriage that is arranged to move horizontally within a support gantry;
FIG. 4 is an enlarged side view with portions broken away showing the internal structure of the elongated boom; and
FIG. 5 is an elongated end view taken along lines 5--5 in FIG. 2 showing the carriage construction in greater detail.
DESCRIPTION OF THE INVENTION
Referring initially to FIGS. 1 and 2, there is illustrated apparatus generally referenced 10 embodying the teachings of the present invention. A conditioning tool 11 is shown secured in the front or distal end 12 of an elongated boom 13 by locking the handle 15 of the tool to the boom via suitable locking bolts 16--16 whereby the tool can be conveniently replaced in assembly. As will be explained in greater detail below, the back or proximal end 17 of the boom is supported within a carriage, generally indicated as 20 (FIG. 3) that is adapted to move back and forth within a horizontally aligned gantry 21 along a prescribed path of travel. The main body of the boom extends outwardly through the front of the gantry and rests within a cradle 22 that is also movably mounted within the gantry forward of the carriage. As best seen in FIG. 2 the boom can be extended outwardly from the gantry a considerable length whereby the tool may be passed through an access door 23 of a high temperature furnace 24 to condition materials contained in the furnace bed 25.
The gantry is adjustably supported upon a gear-driven turntable 26 that is arranged to turn in a generally horizontal plane through 360° of rotation on a chassis 27. The chassis is furnished with a pair of conventional endless treads 28--28 whereby the equipment can be freely propelled over the ground to more accurately position the tool within a furnace or to transport the equipment between work stations. The front end of the gantry is vertically aligned at about the forward edge of the turntable with the main body of the gantry extending back some distance from the rear edge thereof. A drive housing 29 is mounted upon the turntable to one side of the gantry which covers an internal combustion engine for providing power to the drive treads and a gear train (not shown) for powering the turntable. Also enclosed within the housing are one or more pumps for providing hydraulic fluid under pressure to various hydraulic components used to drive systems contained in the present apparatus. A cab 30 is also mounted upon the turntable adjacent to the drive housing which contains controls by which the operator can maneuver the conditioning tool. The cab is furnished with a forward-facing transparent heat shield 31 designed to protect the operator from high furnace temperatures while at the same time affording a substantially unimpeded view of the conditioning tool.
The gantry 21 is fabricated from a plurality of structural elements that are brought together by welding and/or bolting to create a bridge-like section in which the boom is movably supported. With further reference to FIGS. 3-5, the boom is suspended beneath the carriage 20 which is adapted to ride along longitudinally extended rails secured to the sidewalls of the gantry. The carriage includes two opposed bogie plates 32--32 in which a pair of wheels 34--34 are journalled for rotation. A horizontal pivot 35 is secured in each bogie plate between the wheels which, among other things, helps to maintain lateral spacing between the wheel pairs. As best seen in FIG. 3, each wheel pair rides between an upper guide rail 37 and a lower guide rail 38. In practice, the rails may be formed of angle irons welded to the inside sidewalls of the gantry so as to present a horizontally turned leg to the carriage wheels. Side rollers 39, which are supported in the upper guide rails as shown in FIG. 5, prevent lateral displacement of the carriage within the gantry as it moves back and forth over its prescribed path of travel.
The boom is suspended below the carriage by means of side hangers 40--40 (FIG. 3) pivotably mounted upon the pivot and secured to the back end of the boom by means of bolts 41--41. Although not shown, suitable bearing means are provided to allow the boom to freely swing about the pivot in a generally vertical plane.
The carriage is moved back and forth over the rails by means of a pair of coacting hydraulically operated winches 42 and 43 (FIG. 1) mounted atop the gantry directly over the turntable. Forward winch 42 is connected to the carriage via a cable 45 that is brought around forward pulley 46 and passed rewardly through the open front of the gantry. Rear winch 43 is connected to the carriage by a second cable 47 arranged to pass over two cooperating rear pulleys 49 and 50 (FIG. 3) which direct the cable inwardly through the rear of the gantry. The ends of both cables are secured to a raised bar 51 that is mounted in the carriage above the pivot between two upraised elements 52--52. The winches are adapted to work in concert to pull the carriage, and thus the tool boom supported therebeneath, back and forth along the rails thus enabling the tool mounted in the distal end of the boom to be moved rapidly into and out of the furnace.
Boom 13 includes an elongated outer cylinder 55 in which is contained a smaller diameter inner cylinder 56. In assembly the length of the inner cylinder is slightly less than that of the outer cylinder. A rear wall 57 is secured, as for example by bolts 58, to the proximal end of the boom and contains a centrally located hole through which the back end of the inner cylinder is passed in airtight relationship therewith. In assembly, the two superimposed cylinders establish two individual air passages within the boom that are parallelly aligned along the axis of the boom. The passages include an outer passage 60 and an inner passage 61. A pair of radially extended fins 62--62 are spirally wrapped about the outside surface of the inner cylinder. The fins extend outwardly in a radial direction so that they span across the width of the outer passage 60. The fins serve to subdivide the outer passage into a plurality of helical-shaped flow channels. In practice, the fins may be welded to the inner cylinder and permitted to rest against the outer cylinder to help support the inner cylinder in coaxial alignment with the outer cylinder. A cruciform-shaped key 65 is used to prevent axial shifting of one cylinder in relation to the other. The key has a pair of horizontally extended legs 66 that are passed through the wall of the inner cylinder and are affixed as by welding to both the inner and outer cylinder walls to secure the two members together in assembly. A pair of short vertical legs 67--67 are further provided which are also affixed as by welding to the wall of the inner cylinder to add strength to the system and to further prevent moving or twisting of the cojoined members.
At the front or tool supporting end 12 of the boom there is provided a tool holder assembly that is generally referenced 68 (FIG. 4). The assembly includes a cylindrical front wall 69 and a companion cylindrical back wall 70 which are slidably received within the outer cylinder 55 of the boom. A sleeve 71 is passed inwardly through an opening provided in the front wall 69 and is abutted in perpendicular alignment against back wall 70. The assembled components are welded in place to support the sleeve in coaxial alignment within the boom. In practice, the handle 17 of the conditioning tool is slidably received within the sleeve so that it bottoms against the back wall 70. The locking bolts 16--16 are then passed through suitably aligned holes to secure the handle to both the sleeve 71 and the outer cylinder 55 of the boom. A cooling chamber 73 is provided between the sleeve and the outer cylinder wall which communicates with the interior of the boom by means of a number of air ports 75--75 formed in the rear wall of the tool holder.
Cooling air is pumped into the boom from a blower 76 that is secured to a base element 77 carried upon the boom carriage. The discharge duct 77 of the blower is connected directly into the rear end of the boom by means of a flexible connector 78 and an inlet pipe 79. The inlet pipe enters the outer air passage at the rear end of the boom as shown in FIG. 4. Under the influence of the blower, ambient cooling air is pumped into the outer passage 60 and forced along the spiral channels described by the vanes toward the front end of the boom. At the front end of the boom the cooling air enters a plenum 80 where the flow stream is turned and caused to return in the opposite direction through the inner passage 61 formed by the inner cylinder 56. The cooling air moves along the inner cylinder in counter flow relationship with the incoming stream and is finally exhausted to atmosphere through the rear wall 57 of the boom. A portion of the cooling air that enters the plenum is passed through air ports 75--75 formed in the back wall of the tool holder assembly and is allowed to circulate under natural flow conditions within the cooling chamber 73 to conductively cool both the tool and the tool holder.
The entire boom structure is rendered airtight by either securely welding the component parts in assembly or providing gaskets where necessary to prevent cooling air from inadvertently leaking from the structure. Sufficient quantities of air are moved through the boom to maintain the boom temperature well below a level at which the equipment will be damaged during the period it is exposed to the high furnace temperatures. The vanes mounted within the outer passage of the boom serve to prevent cooling air from becoming stagnated in localized areas and thus creating "hot spots." The spiral passageways also extend the amount of time that the cooling air remains in heat transfer relationship with the outer boom structure thereby increasing the efficiency of the cooling system.
As best seen in FIGS. 1 and 2, the front end of the boom is mounted with a cradle generally depicted as 22. A rest in the form of a forward roll 85 is mounted in a bifurcated arm 86 secured to the carriage. The roll is arranged to ride in rolling contact against the bottom of the boom to enable the boom to be run out and returned by the carriage. As noted, the cradle is also movably supported within the gantry so that the forward rest position can be altered to help balance the boom in assembly.
While this invention has been described with reference to the structure disclosed herein, it is not confined to the details set forth and this application is intended to cover any modifications or changes as may come within the scope of the following claims. | An elongated boom for supporting a tool for conditioning metal or the like within a high temperature furnace. The boom has internal passageway for directing cooling air therethrough so as to reduce the potentially dangerous effects of high temperatures upon the thermally exposed sections of the boom. The boom is supported at one end in a carriage that is arranged to move back and forth within a horizontally aligned gantry to enable a conditioning tool supported in the opposite end of the boom to be readily moved in and out of the furnace. A blower for pumping ambient air into the boom is mounted directly upon the carriage adjacent to the boom eliminating the need for extensive air handling hoses and the like. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates generally to the field of pricing goods for sale and particularly to a method and apparatus for pricing and selling goods in electronic commerce applications using communications networks.
BACKGROUND OF THE INVENTION
[0002] The industrial age has given rise to a global economy of factories engaged in mass production of various goods. An enormous amount of commerce is transacted in the buying and selling of such goods. While some such goods lose their value with use, e.g., food products, many such goods retain a substantial portion of their value even after use or ownership by another. Such goods are referred to herein as “durable”. A considerable amount of commerce is transacted in the buying and selling of durable goods, particularly used durable goods.
[0003] Almost all durable goods are readily identifiable by a standard unique identification code (“ID code”), particularly those that are mass produced. In the case of computer software, music cassettes or compact discs, videocassettes and digital video discs, the ID code may be a human readable Universal Product Code (“UPC”), a thirteen digit ID code that readily identifies the good. In the case of books, magazines or other publications, the ID code may be a ten-digit International Standard Book Number (“ISBN”). Other items are more readily identified by a manufacturer or brand name and a model number, as for baseball cards and consumer electronics, e.g., a Sony® KV-3620 television. Some goods may be identified by more than one type of ID code.
[0004] Many durable and readily identifiable goods are fungible items that derive their value substantially from their common characteristics. For example, a single signed copy of Michael Jackson's album titled “Thriller” and recorded on a compact disc (“CD”) derives much of its value because it is signed by the performance artist. Such a CD is unique and therefore is not a fungible good. In contrast, an unsigned copy of Michael Jackson's “Thriller” CD derives substantially all of its value because of the songs recorded thereon. Therefore, all such CD's have substantially the same value to consumers. Such CD's are therefore fungible.
[0005] Auctions provide one type of marketplace for selling goods. Used goods sold at auction are sold at prices set by interested buyers. An auctioneer facilitates sale transactions without the need to maintain goods in inventory. Auctions are particularly good for sellers to insure a highest possible sale price, especially for unique, non-fungible items. However, determining and ensuring a fair price is difficult for buyers. Buyers must have a high degree of knowledge to determine whether a price for a certain good is fair.
[0006] Retail selling also provides a marketplace for sale of goods. Used goods sold at retail are sold at prices set by a seller. Retail selling is advantageous to the seller because it allows the seller to control the price of the good. However, it requires the seller to maintain a large inventory of goods, which is expensive and disadvantageous. Competition, particularly for fungible goods, drives prices downward which is advantageous to the buyer. The seller must have a high degree of knowledge to ensure that his price is competitive. In addition, a price for a good may be fair to the buyer when set by the seller, but may no longer be fair if market conditions change after the price is set and before the buyer purchases the good.
[0007] Electronic commerce, or Internet-based sales are common and have problems similar to retail. Numerous online auctions may be found. An example of such an online auction is held by eBay Inc. of San Jose, Calif., at www.ebay.com. Such auctions are better suited to unique goods but are also used for fungible goods. However, “bidding wars” between buyers can lead to high prices for such goods, whether new or used.
[0008] Retail type sales are also conducted at numerous online websites, such as www.amazon.com. Online retail selling is also disadvantageous because it requires the seller to maintain a substantial inventory of goods. A reverse-auction system, where a seller may accept a price set by a buyer is provided on the worldwide web at www.priceline.com by priceline.com Inc. of Stamford, Conn. U.S. Pat. No. 5,797,127 to Walker et al. discloses a reverse auction method, apparatus and program for pricing, selling and exercising options to purchase airline tickets.
[0009] For electronic commerce applications, software-implemented shopping agents are well known. Using a shopping agent, a buyer can identify vendors and prices for a good. One type of shopping agent queries multiple vendor's websites to determine a best price or list of prices. For example Cendant Corp. of New York, N.Y. is a retail seller of new books which provides access to such a shopping agent on the worldwide web at www.books.com. Books.com uses a pricing agent (“Price Compare”) to price items it sells and holds in its inventory. It uses the shopping agent to query several competitors and, if its price for a new book is not less than its competitors' prices, the pricing agent sets the price for its new book at less than the lowest competitor's price for the same new book. However, the seller still controls the price since it determines the method used by its pricing agent to set the price. In addition, the seller is required to maintain a substantial inventory of books.
[0010] Until now, there has been no acceptable way to facilitate sales of goods which ensures fair pricing while eliminating the need for inventory and minimizing pricing burdens on the buyer and the seller. In addition there is no acceptable way to exploit the fungible nature of durable goods.
[0011] Accordingly, it is an object of the present invention to provide a method for facilitating pricing and sales of goods.
[0012] It is another object of the present invention to provide a method which does not require maintenance of an inventory of goods.
[0013] It is yet another object of the present invention to provide a method for pricing goods for sale by independent sellers.
[0014] It is a further object of the present invention to ensure lowest pricing of goods which exploits the fungible nature of goods.
[0015] It is yet a further object of the present invention to exploit the fungible nature of used durable goods to price goods.
[0016] It is yet a further object of the present invention to derive a price for an independent seller's good as a function of a third party's price for a similar good.
[0017] It is yet a further object of the present invention to provide an apparatus for facilitating sales and pricing of goods.
[0018] It is yet a further object of the present invention to provide a computer-implemented method for facilitating sales and pricing of goods.
SUMMARY OF THE INVENTION
[0019] The invention provides a method for facilitating sales and pricing of goods by removing direct price control from the buyer and the seller. The invention automates the pricing process by deriving a sale price from a third party's index price using a method set by either the seller or an intermediary, referred to herein as the “marketeer”. A current index price is determined by reference to a party other than the buyer or seller at a time of listing the good for sale or at a time of the sale. An appealing price for an item may be ensured by using a lowest price of a group of vendors for a comparable good as the index price and deriving a discounted sale price from the index price. The readily identifiable, fungible nature of durable goods is exploited by the sellers to identify used goods to the marketeer using a standard ID code. The good is never received for sale by the marketeer yet its characteristics are known. The marketeer exploits the nature of such goods when determining the index price for a new good and when pricing a used good by deriving from the index price a sale price representing a discount to the buyer for a used good having essentially the same value as a new good.
[0020] A computer-implemented method for pricing an independent seller's good using a marketeer controller is also provided. The marketeer controller is capable of communicating with a buyer interface and a seller interface via a communications network, the marketeer controller including a CPU and a memory operatively connected to the CPU. The marketeer controller stores in its memory a program executable by the CPU for deriving a sale price of the good. The computer-implemented method comprises the steps of: receiving from the buyer via the communications network, an expression of interest in purchasing the good; querying a vendor's controller to determine the vendor's price of a comparable good; and executing the program to derive the sale price of the good using a predetermined method.
[0021] A marketeer controller for processing data for pricing an independent seller's good in accordance with the present invention is also provided. The marketeer controller comprises: a central processing unit (CPU) for executing programs; a memory operatively connected to the CPU; a network interface device operatively connected to the CPU for communicating with a seller interface and a vendor's controller via a communications network; a first program stored in the memory for receiving identification code data from the seller to identify a good and for storing the data; a second program stored in the memory for receiving data from a buyer representing the buyer's interest in purchasing the good; a shopping agent program stored in the memory for querying a vendor's controller to determine the vendor's price of a comparable good similar to the seller's good and for determining an index price as a function of the vendor's price and a pricing agent program stored in the memory for deriving a sale price of the good from the index price using a predetermined method.
[0022] A non-computer-implemented method for pricing an independent seller's good also is provided.
DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a flow diagram providing an example of a transaction in accordance with the present invention;
[0024] FIG. 2 is a block diagram of a marketeer controller in accordance with the present invention; and
[0025] FIG. 3 is a flow diagram providing an example of a computer-implemented method for pricing and facilitating sale of an independent seller's good in accordance with the present invention.
DETAILED DESCRIPTION
[0026] The present invention provides a method and apparatus for facilitating sales between buyers and sellers and pricing goods for sale. A marketeer facilitates sales and pricing of the sellers' goods. In one embodiment an index price is obtained from a third party at a time proximate to the time the buyer wishes to buy the good. In the preferred embodiment, the index price is obtained from a third party at a time proximate to the time the seller registers the good with the marketeer as a good for sale by the seller. The seller agrees, before the sale, to sell his good at a sale price determined by the marketeer using an index price as a reference. The seller may specify a method for deriving the sale price as a function of the index price. Alternatively, the marketeer may specify the method. In alternate embodiments, the seller is presented with additional alternative options for pricing the seller's good, e.g., to specify a fixed price, or to specify a discount from a suggested retail price, i.e., a “list” or “cover” price instead of deriving a price from an index price. The marketeer may optionally store a database of suggested retail prices.
[0027] FIG. 1 is a flow diagram providing an example of a transaction in accordance with the present invention in which the index price is determined at or near the time of the sale. By way of example, the invention will be discussed below in the contexts of sale of a used paperback copy of Sue Grafton's book titled “A is for Alibi”. First, a seller identifies (“registers”) his book for sale with the marketeer as shown at step 20 . The marketeer does not take possession of the book for inventory purposes but rather registers the book as an item for sale. The marketeer presents the book in a marketplace as an item for sale by an undisclosed seller, as shown at step 22 . If the method is computer-implemented, the marketplace may be a website and the book may be presented using images and/or text retrieved from an existing database—such information need not be provided by the seller. To a buyer, it may appear that the book is being offered for sale by the marketeer. In an alternate embodiment, the marketplace could be a conventional type storefront including a booth or kiosk presenting a printed catalog or brochure depicting goods, and/or product samples representing goods for sale.
[0028] The buyer may browse the marketplace and the goods presented for sale by the marketeer. When the buyer expresses an interest in a the book, the marketeer determines an index price for the book, as shown at steps 24 and 26 . In one embodiment, the index price is an independent third party's price for a comparable good, preferably a new book, if the seller is offering a used book. In an alternate embodiment, the index price is the lowest price among a group of independent third parties' prices for the comparable good. If the method is computer-implemented, the index price may be determined by querying a third party vendor's computer or web server, e.g., using a standard product identification code such as a universal product code (“UPC”) or International Standard Book Number (“ISBN”). For example, the marketeer could query amazon.com to determine that amazon.com is selling a new paperback copy of “A is for Alibi” for $10 and set the index price to $10. Determining an index price proximate the time of sale to the buyer ensures a fair or lowest price for the good relative to other vendors' prices.
[0029] The marketeer then derives a sale price from the index price, as shown at step 28 . In one embodiment, the method for deriving the price is determined by the marketeer. In another embodiment, the method for deriving the price is specified by the seller at the time the seller presents the good to the marketeer for sale. For example, the method may represent a discount from the index price, e.g., a 50% discount from the index price. In this example, the marketeer derives a sale price of $5 for the seller's used book by applying a 50% discount to amazon.com's price of $10 for a new paperback copy of “A is for Alibi”. This ensures that the sale price is fair, in one embodiment, or the lowest price, in another embodiment. The marketeer then presents the book for sale to the buyer at the sale price. If the buyer decides to buy the book at the sale price, the marketeer facilitates the purchase/sale transaction between the buyer and the seller, as shown at step 30 and 32 . The marketeer may facilitate the sale, for example, by identifying the buyer to the seller and the seller to the buyer and permitting the buyer and seller to complete the transaction. Alternatively, the marketeer may facilitate the same by referring the parties to a third party intermediary acting as a clearinghouse for the transaction, or by acting as the clearinghouse itself. When the marketeer acts as the clearinghouse, it receives only sold goods and therefore has no inventory in the traditional sense. In the preferred embodiment, the marketeer is compensated for facilitating the transaction.
[0030] It should be appreciated that such a transaction may be implemented in a variety of ways. For example, all communications between the buyer, seller, marketeer, and vendors could be made between humans by telephone. However, in the preferred embodiment, the inventive method is software-implemented in an electronic commerce application and all communications are transmitted electronically between computers communicating via a communications network.
[0031] In the preferred embodiment, the marketeer provides an electronic marketplace, e.g., a website, wherein sellers of goods can register their goods with the marketeer for sale. The website is accessible to buyers and sellers via a communications network, such as the Internet. Buyers and sellers can communicate with the marketeer, or its marketeer controller, e.g., a web server, using an interface and interface software. For example, the buyer and seller interface may each comprise a personal computer running standard web browser software and having network access capability, as is known in the art.
[0032] FIG. 2 is a block diagram of a marketeer controller 70 in accordance with the present invention. The marketeer controller also includes a central processing unit (“CPU”) 72 , random access memory (“RAM”) 74 , read only memory (“ROM”) 76 , and a communications port (“COMM PORT”) 78 connected to a network interface device 80 for communicating over a communications network. The marketeer controller 70 also includes a storage memory including a storage device 82 for storing data including a first program for receiving identification code data from a seller to identify a good presented for sale by a seller, a second program for receiving data representing a buyer's interest in purchasing a good, a shopping agent program for identifying an index price, a pricing agent program for deriving a sale price and other data required to complete sale transactions, e.g. buyer's and sellers identity or contact information, information representing seller's selection of a method for deriving a price, etc.
[0033] The marketeer controller is interconnected with or interconnectable to buyer and seller interfaces (i.e., computers running standard web browser software) via a communications network such that information can be transmitted back and forth between the buyer and seller interfaces and the marketeer controller and such that the marketeer controller can transmit information back and forth between third party vendors' computers (not shown).
[0034] FIG. 3 is a block diagram showing flow of an example of a computer-implemented method for pricing and facilitating sale of an independent seller's good in which the index price is determined near a time of registering the good for sale. A seller first reaches the marketeer's website, as shown at step 100 . In effect, the seller is entering the marketeer's virtual marketplace. A seller may do so by visiting the marketeer's website using his buyer interface, i.e., personal computer, to access the marketeer controller via the communications network. The seller then identifies to the marketeer a good he wishes to sell, in effect, registering the good for sale with the marketeer. To do so, the seller submits a standard identification code to the marketeer, as shown at step 110 . This may be achieved by the seller using his keyboard to enter the code into a field provided by the marketeer's website, as is known in the art. The standard identification code may be a universal product code (UPC) or an International Standard Book Number (ISBN), for example. The use of a standard identification code identifies the good in a manner readily identifiable by the marketeer and/or buyers. The marketeer controller stores the identification code in its memory to register the good as an item for sale by the seller, as shown at step 120 . The marketeer controller may also store in its memory data provided by the seller to identify the seller as the owner of the good.
[0035] In accordance with the method, the seller does not specify a price but rather specifies a method for determining a sale price from an index price, as shown at step 130 . As discussed above, the method could include a discount from a manufacturer's list price. In the preferred embodiment, the seller specifies a method including a discount from a price of a comparable new good by a certain percentage. This may be achieved, for example, by the seller's selection of an option from a menu presented by the marketeer, e.g., by selecting a button or check-box using his mouse, as is well known in the art. For example, the marketeer may present a menu of options for a 70% discount from a manufacturer's suggested retail price, a 70% discount from a price for a comparable new good, a 50% discount from a manufacturer's suggested retail price, or a 50% discount from a price for a comparable new good. The marketeer controller also stores in its memory data indicating the method specified by the seller for pricing the good, as shown at step 140 . In one embodiment, the seller is also presented with an option for specifying a fixed price for the good.
[0036] The marketeer determines an index price for the good, as shown at step 150 . In the preferred embodiment, determination of the index price is performed by the marketeer controller. To do so, the monitor controller queries multiple third party vendors of comparable goods to determine their respective prices and to equate the index price to the lowest price of a group of third party vendors for a new good similar to the used good offered for sale by the seller. The querying step is performed by a shopping agent program stored in the memory of the marketeer controller. It is advantageous to use a standard product identification code, such as the UPC, to perform the query.
[0037] The marketeer then derives a sale price of the good from the index price using the method specified by the seller, as shown at step 160 . This is performed by a pricing agent program stored in the memory of the marketeer controller. Preferably, the method includes a discount of the index price by approximately fifty percent to determine the sale price of the seller's good. In one embodiment, the seller is presented with the sale price and asked to confirm his desire to offer the good for sale at the sale price. After the marketeer controller has derived the sale price, it stores in its memory the sale price of the good.
[0038] At this point, the good is registered with the marketeer for sale by the seller. The marketeer has not taken possession of the good. After a period of time, a buyer enters the marketeer's marketplace by reaching the marketeer's website, as shown at step 170 , using his personal computer to communicate with the marketeer controller via the communications network. The buyer may browse the marketeer's website to shop for a good. Presentation of electronic storefronts, including browsing and searching abilities is well known in the art. For example, books, music, and videos may be categorized by content or genre. Alternatively, for example, a buyer interested in a particular book may search by subject, author or title, and view an image of the cover of the book, read a description or review of the book, etc. In another embodiment, a buyer could search for an item using its standard unique ID code. Any method of categorizing, cataloging or searching may be used which enables a buyer or potential buyer to find a good for which he is looking or in which he may be interested.
[0039] If the buyer is interested in the possibility of purchasing a good, the buyer expresses interest in buying the good, as shown at step 180 . The buyer may do so using any suitable method, as are well known in the art. For example, a buyer may use his mouse to select a button or click a checkbox displayed on a web page and appearing on his video monitor.
[0040] The marketeer then presents the good to the buyer for sale at the sale price, as shown at step 190 . This may be achieved by transmitting to the buyer data for displaying the sale price and a description of the good on the video monitor of the buyer's personal computer.
[0041] If the buyer decides to buy the good at the sale price, as shown at step 200 , he may indicate his intent to do so in a manner similar to that described above with reference to expression of his interest in purchasing the good. The marketeer then facilitates the sale transaction between the buyer and the seller, as shown at step 210 . This may be achieved in a variety of ways. For example, the marketeer may refer the parties to an intermediary clearinghouse or escrow agent or may itself act as the intermediary. In the preferred embodiment, the buyer transmits identification information to the marketeer controller which the marketeer controller stores in its memory and the marketeer controller then identifies the seller to the buyer and the buyer to the seller so that they may complete the sale transaction.
[0042] This arrangement works particularly well for readily identifiable, fungible, durable goods which have been pre-owned or used since the goods are readily identified by both the buyer and the seller, all goods, offer similar value to the consumer, and the fact that the good has been used does not significantly deplete the value of the good to the consumer.
[0043] In this manner, fair prices are ensured to buyers and sellers by allowing a price to be set as a function of an independent, third party vendor's price. Advantageously, the marketeer is not required to maintain an expensive inventory of goods, buyers do not have to shop tirelessly to get good values, and sellers don't have to monitor prices of similar goods. Additionally, in one embodiment, the buyer is ensured a lowest price for a good since the sale price is set using the seller-determined method at a discount from the lowest price of a seller or group of sellers of a comparable new good at the time of the sale, particularly when the index price is for a new good and the sale price is for a used good.
[0044] In one embodiment, goods in addition to those listed or registered for sale by sellers at the marketeer's website are presented by the marketeer for browsing by a buyer. Information concerning such additional goods may be retrieved from a database accessible to the marketeer controller. In one embodiment, the marketeer refers the buyer to a third party vendor if the buyer wishes to purchase the good and the good sought by the buyer is not listed for sale with the marketeer, e.g., by presenting a link to the vendor's website. In another embodiment, the seller is presented with opportunities to select a different pricing option and to thereby change the sale price or to remove the good from the marketeer's list of registered goods after registering the good for sale.
[0045] Having thus described particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements as are made obvious by this disclosure are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention.
[0046] Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto. | A method for facilitating sales and pricing of independent parties' goods. The method removes price control from buyers and sellers by deriving a sale price from an index price using a method set by either the seller or a third party. The index price is provided by a party other than the buyer or seller. The sale price may be derived at a time of sale or at a time of registering the good for sale. The standard ID code of readily identifiable, fungible, durable goods is used by sellers to identify used goods to the marketeer. The marketeer exploits the nature of such goods by choosing the price of a comparable new good as an index price and deriving a discounted sale price for the used good from the price of a new good having essentially the same value due to its fungible, durable nature. A best price for a good is ensured by using as the index price a lowest price among a group of vendors for a comparable good.
In a computer-implemented version of the method, a shopping agent program is used to query one or more vendors to determine a best price for a comparable good and a pricing agent program is used to derive a discounted sale price for the good from the best price for the new good.
An apparatus for performing a computer-implemented version of the inventive method is also provided. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns an insole of elastic material with recesses for taking up exchangeable elastic inserts. A treatment of the foot can be obtained by exchangeable inserts and being able to exercise a greater or lesser pressure at the places of the inserts in comparison to the pressure derived from the material of the inserted sole.
2. Description of the Prior Art
Such an inserted sole is known from DE Patent 845,557, in which the recesses consist of stampings that have penetrated through the material.
Another form of such an inserted sole is described in DE OS 3,713,786, wherein the recesses do not penetrate in the side turned toward the sole of the foot in the inserted sole, but rather true cavities are provided, in which inserts are fitted.
A problem arises in such inserted soles with respect to holding the inserts. Nothing is disclosed in DE Patent 845,557 in this respect. In DE OS 3,713,786, a measure is described for this purpose, which is to provide the sides of the insert adjacent the bottom of the recess with an adhesive. A tight fastening of the inserts is accomplished in this way for the inserts used for the first time, but the adhesive rapidly loses its adhesive force, if the insert is changed several times, which is always the case when there is the necessity within the scope of treatment to use inserts of varying elasticity.
SUMMARY OF THE INVENTION
The invention provides a simple and secure means for holding the inserts, which makes possible a practical exchange of the inserts that can occur as frequently as desired.
According to the invention at least over the region of the inserts, the inserted sole is provided on the side of the recesses with a first layer of a flat adhesive seal as a bearing part, leaving open the recesses, and over this bearing part. Another or second layer of the flat adhesive seal, including the inserts, extends as a covering part.
The furnishing of the inserted sole with a bearing part of a flat adhesive seal, leaving the recesses open, which can be accomplished, e.g., by a permanent adhesive seal which makes it possible, after introducing the inserts, to provide these inserts and the regions of the inserted sole free of inserts with the covering part of the adhesive seal, which holds these inserts securely in their recesses on the basis of its covering of these inserts. Thus, the property of the adhesive seal is utilized, and the covering part can be pulled off the bearing part, without these parts losing their capability of again joining and adhering to each other. By means of flat adhesive seals configured in this way, it is therefore possible without anything further to secure the inserts in their recesses and to change them in a practical manner as often as desired.
Appropriately the padded part or pile is used as the bearing part, and the burred part or hooks of the flat adhesive seal is used as the covering part. In this case, the inserted sole offers a soft support by means of the padded part with respect to the inner sole of a shoe, if by mistake the covering part is not applied.
If the covering part is extended only over the region of the inserts, there results a corresponding savings in material for the covering part and also for the bearing surface with the same extension. For reasons of manufacture, the bearing part may also extend essentially over the entire inserted sole. In this case, the covering part may also be formed in the appropriate dimensions, i.e., the covering part also extends over the entire bearing part.
In order to provide the inserted sole itself with a good adhesive bond to the inner sole of the shoe, adhesive parts can be provided next to the region of the inserts, which are joined with the inserted sole on the side of the bearing part, to penetrate the holding or covering part, and are provided with a layer of self-adhering adhesive turned away from the inserted sole. An inserted sole configured in this way is held against slipping on the inner sole by means of the adhesive seal after it has been inserted in a shoe. The adhering part may or may not be provided with a covering sheet. Appropriately, the design of the finished inserted sole with inserts, flat adhesive seal, as well as adhering parts with a covering sheet is produced, since this assembly cannot slip.
An example of embodiment is shown in the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an inserted sole obliquely viewed from below with inserts, which are enclosed by a covering part extending only over the region of the inserts.
FIG. 2 shows a variant of the form of embodiment according to FIG. 1 with bearing part and covering part extending over the entire inserted sole.
FIG. 3 shows a section along line III--III of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The inserted sole 1 shown in FIG. 1 consists of the sole part 2 of a flexible material, e.g., silicone rubber, into the underside 4 of which recesses 6, viewed from FIG. 3, are made. The inserts 8 adapted to the latter are inserted into recesses 6, and these inserts are also made of elastic material, e.g., silicone rubber. On underside 4 of sole part 2, in the region of inserts 8, the bearing part 12 of a flat adhesive seal (10) is attached (e.g., by gluing) which leaves space for inserts 8, and covering part 14 extends over this. The covering part is represented in FIG. 1 partially drawn away from bearing part 12. Bearing part 12 and covering part 14 have the same dimensions, so that covering part 14 completely covers bearing part 12, if the covering part is completely pressed down on bearing part 12. In the pressed position of covering part 14, which is shown in the region of the two right inserts, covering part 14 solidly holds inserts 8 in their recesses, so that the latter cannot fall out when the inserted sole 1 is worn. In the case of the drawn-away covering part 14 (see the three left inserts 8), inserts 8 may be removed from their recesses and can be replaced by other, e.g., harder or softer inserts, depending on the desired therapeutic effect. Adhesive seal 10 therefore provides for a secure adhering of covering part 14 onto bearing part 12, whereby the known function of the adhesive seal provides for the fact that covering part 14 can be withdrawn repeatedly from bearing part 12 and can be again pressed onto the latter, whereby a secure fastening of inserts 8 in their recesses 6 is constantly assured.
Further, adhering parts 18 are glued onto the underside 4 of sole part 2, and these are provided with a self-adhering layer, over which covering sheet 20 is applied. After withdrawing covering sheet 20 from adhering parts 18, the inserted sole 1 may be inserted into a shoe, in which inserted sole 1 is then given a secure position based on the adhesive effect of adhering parts 18.
In FIG. 2 is shown an inserted sole 1 with a sole part 2, which is provided with five inserts 8, as in the inserted sole 1 according to FIG. 1, in the region of the toe joint, and these inserts are inserted into recesses corresponding to the form of embodiment shown in FIG. 1. In addition to these inserts 8, insert 28, in sole part 2, is inserted into a corresponding recess, by means of which a greater or lesser pressure can be exercised on the heel. The introduction of insert 28 in sole part 2 is conducted in the same way as is the case for inserts 8. This will be described individually in connection with FIG. 3.
Sole part 2 according to FIG. 2 is provided on its entire underside with bearing part 32 of adhesive seal 30, whose covering part 34, like bearing part 32, covers underside 4 of the entire sole part 2. Thus the regions of inserts 8 and 28 are left open by bearing part 32 (as in the form of embodiment according to FIG. 1), and thus the respective inserts 8 or 28 can be changed when cover part 34 is withdrawn.
As in the case of the form of embodiment according to FIG. 1, inserted sole 1 according to FIG. 2 is provided with holding parts 18, which penetrate covering part 34, which is provided for this purpose with recesses 36. Covering parts 18 are adhered onto bearing part 32 with their side turned toward sole part 2. Then by means of holding or covering parts 18, as in the form of embodiment according to FIG. 1, inserted sole 1 can be attached in an adhesive manner in a shoe according to FIG. 2.
The section represented in FIG. 3 along line III--III from FIG. 1 shows the introduction of an insert 8 into a recess 6 of sole part 2. Bearing part. 12 from FIG. 1 (in the form of embodiment according to FIG. 2 this would be bearing part 32) is glued onto sole part 2, and this bearing part is provided in the region of inserts 8 with recesses 16, by means of which inserts 8 can then be removed and again inserted. Covering part 14, which forms adhesive seal 10 together with bearing part 12, is pressed onto bearing part 12, whereby covering part 14 is formed as the burred part and bearing part 12 is formed as the padded part of the flat adhesive seal. This arrangement has the advantage that when covering part 14 is omitted, padded part 12 presses against the inside sole of the respective shoe, and if this were not the case, if rather bearing part 12 were formed of the burred part, a roughness would result due to the individual hooks of the burred part.
In the forms of embodiment of the inserted sole represented in the figures, the latter is provided with inserts and adhesive seal on its underside 4, thus the side turned toward the inner sole of the shoe. However, it is also possible to provide the inserts with the respective recesses and adhesive seal covering on the upper side of the inserted sole. In this case the adhesive seal covering would be turned toward the sole of the foot. The adhering parts for fastening the inserted sole to the inner sole of the shoe would thus of course remain on the underside of the inserted sole. | Described is an insole made of elastic material with recesses designed to accommodate replaceable elastic inserts. At least in the zone in which the inserts are located, the insole has, on the same side as the recesses, a first layer of Velcro™ fabric with apertures which fit over the recesses, the first layer acting as a supporting layer for another second layer of Velcro™ fabric which covers it completely, including the inserts. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 10-2010-0112671, filed on Nov. 12, 2010, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] One or more embodiments of the following description relate to a bus arbitration apparatus and method, and more particularly, to a bus arbitration apparatus and method based on characteristics of masters.
[0004] 2. Description of the Related Art
[0005] Recently, as various types of application programs are implemented in a single system, the number of masters forming a system is increasing, and types and characteristics of masters are becoming diverse. Accordingly, a conventional bus arbitration method has been developed by focusing on a best performance shown by each of various masters in a system.
[0006] However, to improve overall system performance, performance of each master needs to be efficiently adjusted.
[0007] For example, assuming that four processors and a single shared memory are connected to a single bus system, when a request of a single processor transmitted to a bus is processed preferentially, 100% performance of the processor may be achieved, however, the other three processors may not achieve 100% performance, due to the influence of the preferentially processed processor. In this example, overall system performance may be matched to the three processors, instead of the processor achieving 100% performance. Accordingly, such a bus arbitration scheme may cause an efficiency problem.
SUMMARY
[0008] The foregoing and/or other aspects are achieved by providing a bus arbitration apparatus for arbitrating a plurality of masters sending an arbitration request, the bus arbitration apparatus including a processor to control one or more processor-executable units, a collection unit to collect the arbitration request and accumulated arbitration information for each of the plurality of masters, a Quality of Service (QoS) analyzing unit to classify the plurality of masters into a plurality of master types based on a master characteristic of each of the plurality of masters, and to compute a delay time for each of the plurality of masters based on the accumulated arbitration information, the arbitration request, and the plurality of master types, and an arbitration unit to generate a bus arbitration signal based on the plurality of master types and the delay time, the bus arbitration signal being used to arbitrate the plurality of masters.
[0009] The foregoing and/or other aspects are achieved by providing a bus arbitration method for arbitrating a plurality of masters sending an arbitration request, the bus arbitration method including collecting the arbitration request and accumulated arbitration information for each of the plurality of masters, classifying the plurality of masters into a plurality of master types based on a master characteristic of each of the plurality of masters, computing, by way of a processor, a delay time for each of the plurality of masters based on the accumulated arbitration information, the arbitration request, and the plurality of master types, and generating a bus arbitration signal based on the plurality of master types and the delay time, the bus arbitration signal being used to arbitrate the plurality of masters.
[0010] The foregoing and/or other aspects are achieved by providing a bus arbitration apparatus for arbitrating a plurality of masters each sending an arbitration request. The bus arbitration apparatus includes a processor to control one or more processor-executable units, a Quality of Service (QoS) analyzing unit to classify the plurality of masters into a plurality of master types based on a master characteristic of each of the plurality of masters and to compute a delay time for each of the plurality of masters based on arbitration information accumulated for each of the plurality of masters, the arbitration requests, and the plurality of master types, and an arbitration unit to generate a bus arbitration signal to arbitrate the plurality of masters based on the plurality of master types and the delay time.
[0011] The foregoing and/or other aspects are achieved by providing a bus arbitration method for arbitrating a plurality of masters each sending an arbitration request. The bus arbitration method includes classifying the plurality of masters into a plurality of master types based on a master characteristic of each of the plurality of masters, computing, by way of a processor, a delay time for each of the plurality of masters based on arbitration information accumulated for each of the plurality of masters, the arbitration requests, and the plurality of master types, and generating a bus arbitration signal to arbitrate the plurality of masters based on the plurality of master types and the delay time.
[0012] Additional aspects, features, and/or advantages of example embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and/or other aspects and advantages will become apparent and more readily appreciated from the following description of the example embodiments, taken in conjunction with the accompanying drawings of which:
[0014] FIG. 1 illustrates a block diagram of a configuration of a bus arbitration apparatus according to example embodiments;
[0015] FIG. 2 illustrates a diagram of master types according to example embodiments;
[0016] FIG. 3 illustrates a graph of a performance of a single transmission real-time master according to example embodiments;
[0017] FIG. 4 illustrates a graph of a performance of a single transmission non-real-time master according to example embodiments;
[0018] FIG. 5 illustrates a graph of a performance of a multi-transmission real-time master according to example embodiments;
[0019] FIG. 6 illustrates a graph of a performance of a multi-transmission non-real-time master according to example embodiments;
[0020] FIG. 7 illustrates a graph of a time table associated with data transmission of a single transmission master according to example embodiments;
[0021] FIG. 8 illustrates a graph of a time table associated with data transmission of a multi-transmission master according to example embodiments; and
[0022] FIG. 9 illustrates a flowchart of a bus arbitration method according to example embodiments.
DETAILED DESCRIPTION
[0023] Reference will now be made in detail to example embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Example embodiments are described below to explain the present disclosure by referring to the figures.
[0024] FIG. 1 illustrates a block diagram of a configuration of a bus arbitration apparatus according to example embodiments.
[0025] Referring to FIG. 1 , a bus arbitration apparatus 100 for arbitrating a plurality of masters sending an arbitration request for a bus system may include, for example, a collection unit 110 , a Quality of Service (QoS) analyzing unit 120 , and an arbitration unit 130 .
[0026] The collection unit 110 may collect the arbitration requests and accumulated arbitration information for each of the plurality of masters.
[0027] The accumulated arbitration information may include at least one of requested data amount information, transmitted data amount information, remaining data amount information, and current time information.
[0028] The QoS analyzing unit 120 may classify the plurality of masters into a plurality of master types based on a master characteristic of each of the plurality of masters.
[0029] The plurality of master types may include a single transmission real-time master, a multi-transmission real-time master, a single transmission non-real-time master, and a multi-transmission non-real-time master. Hereinafter, the plurality of master types will be further described with reference to FIG. 2 .
[0030] FIG. 2 illustrates a diagram of master types according to example embodiments.
[0031] Referring to FIG. 2 , a master 200 may be divided into a real-time master 211 , and a non-real-time master 212 .
[0032] The real-time master 211 may be a master for which performance is reduced to “0” when a bus insufficiently supports an amount of data required to be transmitted.
[0033] The non-real-time master 212 may be a master for which performance is reduced at a predetermined ratio when a data processing time takes longer than a time requirement.
[0034] The real-time master 211 may be divided into a single transmission real-time master 221 , and a multi-transmission real-time master 222 .
[0035] Additionally, the non-real-time master 212 may be divided into a single transmission non-real-time master 223 , and a multi-transmission non-real-time master 224 .
[0036] A single transmission master classified as the single transmission real-time master 221 or the single transmission non-real-time master 223 may be a master for processing data by transmitting the data once.
[0037] Accordingly, the single transmission real-time master 221 may process data by transmitting the data once, and may have the performance that is reduced to “0” when a bus insufficiently supports an amount of data required to be transmitted.
[0038] Additionally, the single transmission non-real-time master 223 may process data by transmitting the data once, and may have the performance that is reduced at a predetermined ratio when a data processing time takes longer than a time requirement.
[0039] A multi-transmission master classified as the multi-transmission real-time master 222 or the multi-transmission non-real-time master 224 may be a master for processing data by transmitting the data multiple times.
[0040] Accordingly, the multi-transmission real-time master 222 may process data by transmitting the data multiple times, and may have the performance that is reduced to “0” when a bus insufficiently supports an amount of data required to be transmitted.
[0041] Additionally, the multi-transmission non-real-time master 224 may process data by transmitting the data multiple times, and may have the performance that is reduced at a predetermined ratio when a data processing time takes longer than a time requirement.
[0042] Since the single transmission real-time master 221 , the multi-transmission real-time master 222 , the single transmission non-real-time master 223 , and the multi-transmission non-real-time master 224 have different characteristics as described above, each performance may be changed in different forms when data processing is delayed. Hereinafter, a change in performance depending on a delay of data processing will be described in detail with reference to FIGS. 3 to 6 .
[0043] FIG. 3 illustrates a graph of the performance of a single transmission real-time master according to example embodiments.
[0044] Referring to the graph 300 of FIG. 3 , the single transmission real-time master may process data by transmitting the data once, in response to a single arbitration request 310 . Additionally, when a bus insufficiently supports an amount of data required to be transmitted, the performance of the single transmission real-time master may be reduced to “0”, as indicated by reference numeral 320 .
[0045] The performance of the single transmission real-time master may be computed, as given in Equation 1.
[0000] Single transmission real-time master=(Delay time>0) 0:100 [Equation 1]
[0046] FIG. 4 illustrates a graph of the performance of a single transmission non-real-time master according to example embodiments.
[0047] Referring to the graph 400 of FIG. 4 , the single transmission non-real-time master may process data by transmitting the data once, in response to a single arbitration request 410 . Additionally, when a data processing time takes longer than a time requirement, the performance of the single transmission non-real-time master may be reduced at a predetermined ratio, as indicated by reference numeral 420 .
[0048] The performance of the single transmission non-real-time master may be computed, as given in Equation 2.
[0000] Single transmission non-real-time master=Time requirement/(Time requirement+Delay time)×100 [Equation 2]
[0049] FIG. 5 illustrates a graph of the performance of a multi-transmission real-time master according to example embodiments.
[0050] Referring to the graph 500 of FIG. 5 , the multi-transmission real-time master may process data by transmitting the data multiple times, in response to a plurality of arbitration requests 511 , 512 , 513 , 514 , and 515 . Additionally, when a bus insufficiently supports an amount of data required to be transmitted, the performance of the multi-transmission real-time master may be reduced to “0”, as indicated by reference numeral 520 .
[0051] The performance of the multi-transmission real-time master may be computed, as given in Equation 3.
[0000] Multi-transmission real-time master=(Delay time>0) 0:100 [Equation 3]
[0052] FIG. 6 illustrates a graph of the performance of a multi-transmission non-real-time master according to example embodiments.
[0053] Referring to the graph 600 of FIG. 6 , the multi-transmission non-real-time master may process data by transmitting the data multiple times, in response to a plurality of arbitration requests 611 , 612 , 613 , 614 , and 615 . Additionally, when a data processing time takes longer than a time requirement, the performance of the multi-transmission non-real-time master may be reduced at a predetermined ratio, as indicated by reference numeral 620 .
[0054] The performance of the multi-transmission non-real-time master may be computed, as given in Equation 4.
[0000] Multi-transmission non-real-time master=Time requirement/(Time requirement+Delay time)×100 [Equation 4]
[0055] Referring back to FIG. 1 , the QoS analyzing unit 120 may compute a delay time for each of the plurality of masters, based on the accumulated arbitration information, the arbitration requests, and the plurality of master types.
[0056] According to an aspect, the QoS analyzing unit 120 may compute a delay time of a single transmission master, based on at least one of delay time restriction condition information, data margin information, transmitted data amount information, requested data amount information, remaining data amount information, and current time information with respect to the single transmission master. Here, the single transmission master may be classified as the single transmission real-time master or the single transmission non-real-time master.
[0057] Additionally, the QoS analyzing unit 120 may compute a delay time of a multi-transmission master, based on at least one of data period information, information on an amount of data transmitted per period, data margin information, transmitted data amount information, remaining data amount information, and current time information with respect to the multi-transmission master. Here, the multi-transmission master may be classified as the multi-transmission real-time master or the multi-transmission non-real-time master.
[0058] Hereinafter, a method of computing a delay time will be further described with reference to FIGS. 7 and 8 .
[0059] FIG. 7 illustrates a graph 700 of a time table associated with data transmission of a single transmission master according to example embodiments.
[0060] A bus arbitration apparatus according to example embodiment may compute a delay time of the single transmission master, based on information set in advance in a bus system, and accumulated arbitration information regarding the single transmission master. Here, the single transmission master may be classified as the single transmission real-time master or the single transmission non-real-time master.
[0061] The information set in advance in the bus system may include information regarding a delay time restriction condition and a data margin 740 .
[0062] Additionally, the accumulated arbitration information regarding the single transmission master may include information regarding a requested data amount 710 , a transmitted data amount 720 , a remaining data amount 730 , and a current time.
[0063] According to an aspect, the bus arbitration apparatus may compute the delay time of the single transmission master, using Equation 5.
[0000] Delay time of single transmission master=(Current time+Remaining data amount+Data margin)−Time requirement [Equation 5]
[0064] Here, the current time may indicate a cycle counted from a time point that an arbitration request 760 is received from the single transmission master.
[0065] The remaining data amount 730 may indicate a data amount obtained by subtracting the transmitted data amount 720 from the requested data amount 710 .
[0066] The requested data amount 710 may indicate a number of pieces of data requested in response to the arbitration request 760 from the single transmission master.
[0067] The transmitted data amount 720 may indicate a number of pieces of data transmitted from the time point that the arbitration request 760 is received from the single transmission master up to the current time.
[0068] The data margin 740 may indicate a number of cycles sufficient to satisfy a time requirement 750 for the single transmission master.
[0069] The time requirement 750 may indicate a value obtained by adding the requested data amount 710 and the delay time restriction condition, and may be computed using Equation 6.
[0000] Time requirement=Requested data amount+Delay time restriction condition [Equation 6]
[0070] Here, the delay time restriction condition may indicate a time obtained by excluding a data transmission cycle from an allowable delay time of the single transmission master.
[0071] FIG. 8 illustrates a graph of a time table associated with data transmission of a multi-transmission master according to example embodiments.
[0072] A bus arbitration apparatus according to example embodiment may compute a delay time of the multi-transmission master, based on information set in advance in a bus system, and accumulated arbitration information regarding the multi-transmission master. Here, the multi-transmission master may be classified as the multi-transmission real-time master or the multi-transmission non-real-time master.
[0073] The information set in advance in the bus system may include information regarding a data period, an amount 810 of data transmitted per period, and a data margin 840 .
[0074] Additionally, the accumulated arbitration information regarding the multi-transmission master may include information regarding a requested data amount 810 , a transmitted data amount 820 , a remaining data amount 830 , and a current time.
[0075] According to an aspect, the bus arbitration apparatus may compute the delay time of the multi-transmission master, using Equation 7.
[0000] Delay time of multi-transmission master=(Current time+Remaining data amount+Data margin)−Time requirement [Equation 7]
[0076] Here, the current time may indicate a cycle counted from an initiation of a data period.
[0077] The data period may indicate a time interval for data transmission.
[0078] The remaining data amount 830 may indicate a data amount obtained by subtracting the transmitted data amount 820 from the amount 810 of data transmitted per period.
[0079] The amount 810 of data transmitted per period may indicate an amount of data that needs to be transmitted during a single data period.
[0080] The transmitted data amount 820 may indicate a number of pieces of data transmitted to a current cycle from the initiation of the data period.
[0081] The data margin 840 may indicate a number of cycles sufficient to satisfy a time requirement 850 for the multi-transmission master.
[0082] The time requirement 850 may indicate a data period, and may be computed using Equation 8:
[0000] Time requirement=Data period [Equation 8]
[0083] Referring back to FIG. 1 , the arbitration unit 130 may generate a bus arbitration signal based on the plurality of master types and the delay time. The bus arbitration signal may be used to arbitrate the plurality of masters.
[0084] According to an aspect, the arbitration unit 130 may group the plurality of masters into a plurality of groups based on the plurality of master types and the delay time.
[0085] The arbitration unit 130 may generate a group arbitration signal for each of the plurality of groups. The group arbitration signal may be used to arbitrate at least one master included in a single group. Depending on example embodiments, different bus arbitration methods may be set for each of the plurality of groups, and a group arbitration signal may be generated for each of the plurality of groups based on the set bus arbitration methods.
[0086] The arbitration unit 130 may generate a bus arbitration signal from the group arbitration signal, based on priority information of the plurality of groups.
[0087] According to an aspect, the arbitration unit 130 may group, in a first group, a master that has a delay time exceeding “0” and that is classified as a single transmission real-time master and a master that has a delay time exceeding “0” and that is classified as a multi-transmission real-time master among the plurality of masters.
[0088] Additionally, the arbitration unit 130 may group, in a second group, a master that has a delay time exceeding “0” and that is classified as a multi-transmission non-real-time master among the plurality of masters, and a master classified as a single transmission non-real-time master among the plurality of masters.
[0089] The arbitration unit 130 may also group, in a third group, a master that has a delay time of “0” and that is classified as a multi-transmission non-real-time master among the plurality of masters.
[0090] The arbitration unit 130 may also group, in a fourth group, a master that has a delay time of “0” and that is classified as a single transmission real-time master, and a master that has a delay time of “0” and that is classified as a multi-transmission real-time master among the plurality of masters.
[0091] Depending on example embodiments, the priority information may be set so that priority levels may be assigned to the first group to the fourth group in a descending order. In other words, the first group may have a highest priority level, and the fourth group may have a lowest priority level.
[0092] The arbitration unit 130 may generate four group arbitration signals for the first group to the fourth group.
[0093] Additionally, the arbitration unit 130 may generate a final bus arbitration signal from the four group arbitration signals, based on the priority information.
[0094] FIG. 9 illustrates a flowchart of a bus arbitration method according to example embodiments.
[0095] The bus arbitration method of FIG. 9 may be performed to arbitrate a plurality of masters sending an arbitration request to a bus system. In FIG. 9 , in operation 910 , accumulated arbitration information and an arbitration request for each of the plurality of masters may be collected.
[0096] The accumulated arbitration information may include at least one of requested data amount information, transmitted data amount information, remaining data amount information, and current time information.
[0097] In operation 920 , the plurality of masters may be classified into a plurality of master types, based on a master characteristic of each of the plurality of masters.
[0098] The plurality of master types may include a single transmission real-time master, a multi-transmission real-time master, a single transmission non-real-time master, and a multi-transmission non-real-time master.
[0099] In operation 930 , a delay time may be computed for each of the plurality of masters, based on the accumulated arbitration information, the arbitration request, and the plurality of master types.
[0100] According to an aspect, in the bus arbitration method, a delay time of a single transmission master may be computed, based on at least one of delay time restriction condition information, data margin information, transmitted data amount information, requested data amount information, remaining data amount information, and current time information with respect to the single transmission master. Here, the single transmission master may be classified as the single transmission real-time master or the single transmission non-real-time master.
[0101] Additionally, a delay time of a multi-transmission master may be computed, based on at least one of data period information, information on an amount of data transmitted per period, data margin information, transmitted data amount information, remaining data amount information, and current time information with respect to the multi-transmission master. Here, the multi-transmission master may be classified as the multi-transmission real-time master or the multi-transmission non-real-time master.
[0102] In operation 940 , a bus arbitration signal may be generated based on the plurality of master types and the delay time. Here, the bus arbitration signal may be used to arbitrate the plurality of masters.
[0103] According to an aspect, in operation 940 , the plurality of masters may be grouped into a plurality of groups based on the plurality of master types and the delay time.
[0104] Additionally, in operation 940 , a group arbitration signal for each of the plurality of groups may be generated. The group arbitration signal may be used to arbitrate at least one master included in a single group. Depending on example embodiments, different bus arbitration methods may be set for each of the plurality of groups, and a group arbitration signal may be generated for each of the plurality of groups based on the set bus arbitration methods.
[0105] Furthermore, in operation 940 , a bus arbitration signal may be generated from the group arbitration signal, based on priority information of the plurality of groups.
[0106] According to an aspect, a master that has a delay time exceeding “0” and that is classified as a single transmission real-time master or a multi-transmission real-time master among the plurality of masters may be grouped in a first group.
[0107] Additionally, a master that has a delay time exceeding “0” and that is classified as a multi-transmission non-real-time master among the plurality of masters, and a master classified as a single transmission non-real-time master among the plurality of masters may be grouped in a second group.
[0108] Furthermore, a master that has a delay time of “0” and that is classified as a multi-transmission non-real-time master among the plurality of masters may be grouped in a third group.
[0109] Moreover, a master that has a delay time of “0” and that is classified as a single transmission real-time master or a multi-transmission real-time master among the plurality of masters may be grouped in a fourth group.
[0110] Depending on example embodiments, the priority information may be set so that priority levels may be assigned to the first group to the fourth group in a descending order. In other words, the first group may have a highest priority level, and the fourth group may have a lowest priority level.
[0111] In the bus arbitration method, four group arbitration signals for the first group to the fourth group may be generated.
[0112] Additionally, a final bus arbitration signal may be generated from the four group arbitration signals, based on the priority information.
[0113] The above-described example embodiments may be recorded in non-transitory computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The program instructions recorded on the media may be those specially designed and constructed for the purposes of the example embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVDs; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like.
[0114] Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described example embodiments, or vice versa. Any one or more of the software modules or units described herein may be executed by a dedicated processor unique to that unit or by a processor common to one or more of the modules. The described methods may be executed on a general purpose computer or processor or may be executed on a particular machine such as the bus arbitration apparatuses described herein.
[0115] Although example embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these example embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents. | A bus arbitration apparatus and method are provided. A plurality of masters may be classified into master types based on master characteristics, and bus arbitration may be performed. Thus, it is possible to prevent a bus from being distributed to a predetermined master, and it is possible to improve overall performance of a bus system by solving a problem of unbalanced distribution of performance between the plurality of masters. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a process for preparing dialdehydes, and more particularly to a process for preparing dialdehydes in high productivity in the presence of a catalyst of silver particles specially prepared to prevent them from aggregation.
There have hitherto been known processes for preparing dialdehydes by subjecting glycols to oxidation-dehydrogenation in the presence of a silver catalyst, as disclosed in, for instance, Japanese Unexamined Patent Publication No. 103809/1979, No. 203024/1982 and No. 59933/1983, and the like. Since the silver catalyst gives higher conversion of glycols and higher selectivity into dialdehydes than other catalysts do, it is most expectd that the silver catalyst be put to practical use in industrial production.
Although the silver catalyst has excellent selectivity, many problems have to be solved until it can be used in practical operation, such that (1) the high selectivity is incompatible with the high conversion, (2) the conversion is lowered due to shrinkage with the passage of time or aggregation of the catalyst, and the like.
When the production of dialdehydes using the silver catalyst is carried out at a higher temperature in expectation to obtain higher conversion, the shrinkage and aggregation of the catalyst further rapidly progress to result in rapid increase in pressure drop and generation of clearance between the reactor wall and a catalyst bed in an early stage of reaction. Thus, once obtained higher conversion quickly deteriorates in short period of time and the catalyst used in such a way can no longer continue efficient reaction and becomes impossible to reuse. In other words, the catalyst of the silver particles has a very short life.
In order to solve the above defects, there are some proposals as to processes, in which a silver catalyst is also used, to prepare formaline from methanol. For instance, it is proposed to use a silver-gold alloy catalyst in Japanese Unexamined Patent Publication No. 112806/1979, but this proposal is not practical from the point of view of the total cost required for raw materials of catalyst and recovery, and the like. Also, Japanese Unexamined Patent Publication No. 133214/1976 proposes a process using silver particles having a specific particle size (0.01 to 10 μ) or a specified range of specific surface area (3 to 30 m 2 /g), Japanese Unexamined Patent Publication No. 13307/1975 proposes a process wherein silver particles with different particle size are packed in a column to form three or more layers in a certain proportion, Japanese Unexamined Patent Publication No. 33428/1980 proposes a process wherein a net of a metal such as silver or copper is located in a middle of a catalyst layer.
The above proposals in the formaline production process also produce good results in the production of the dialdehydes to a certain extent, but none of them can be substantial solutions to the aforementioned problems. Generally, it is required in commercial plants to start and stop the reaction repeatedly from various operational reasons or troubles. But, by the methods according to the above proposals, if the inner temperature of the reactor decreased to about 300° C. due to interruption of reaction, the catalyst layer is no longer usable because of cracks generated in it and the clearance between the reactor wall. Consequently, it is required to replace the used catalyst with new one. However, it is not easy to take it out from the reactor because the used catalyst is strongly aggregated in the reactor.
An object of the present invention is to provide processes for preparing dialdehydes from glycols in a high conversion of glycols and a high selectivity into dialdehydes, avoiding the above-mentioned problems.
This and other objects of the present invention will become apparent from the description hereinafter.
SUMMARY OF THE INVENTION
It has now been found that when silver particles partially coated with a silicon carbide powder or silicon nitride powder is used as a catalyst in the preparation of dialdehydes from glycols, the problem of cracks, clearance and sintering of catalyst layer can be avoided and eventually there is no significant increase of pressure drop across the catalyst layer for a long period of time of operation. Thus, the new catalyst arrangement exhibits remarkable effects such that the catalyst life is extended considerably, that the conversion of glycols and the selectivity into dialdehydes are maintained at a high level for a long time and that the used catalyst becomes reusable through a simple processing.
According to the present invention, there is provided a process for preparing a dialdehyde which comprises subjecting a glycol to oxidation-dehydrogenation in the presence of silver particles of which the surface is partially coated with a powder of a silicon carbide or a silicon nitride.
DETAILED DESCRIPTION
In the present invention, as a silver catalyst, silver particles are used. Preparation methods of silver particles are not particularly limited and any preparation methods such as a method by electrolysis and a method using an atomizer are applicable to the present invention. There can be practically used silver particles with a particle size of about 5 to 200 mesh, preferably from about 10 to 80 mesh.
In the present invention, it is essential to partially coat the surface of silver particles with the silicon carbide powder or silicon nitride powder. The powder of silicon carbide or silicon nitride with a particle size of 0.01 to 100 μ, preferably from 0.1 to 10 μ, shows remarkabe effect.
As a process for coating the silver particles with the powder of silcon carbide or silicon nitride, it is generally practiced that the silver particles are dry-mixed with the powder of silicon carbide or silicon nitride in a mixer such as a V-shaped blender, and obtained the mixture is heat-treated at a temperature of about 600° to 800° C. to let the silicon powder deposit onto the silver particles. In the present invention, it is necessary to partially coat the silver particles with the silicon powder. It is generally arranged so that the silicon powder covered 1 to 20% of the surface of silver particle and more preferably 5 to 10% of the surface. When the silver particle is completely covered with the silicon powder, it shows poorer catalytic activity.
The silicon carbide or silicon nitride powder is used within a range of an amount of 0.05 to 5.0% by weight, preferably from 0.2 to 2.0% by weight, of the coated silver particle. The silicon carbide powder and the silicon nitride powder may be used alone or as an admixture thereof.
As glycols used as a raw material in the present invention, there are typically exemplified glycols having the formula: HO--CH 2 ) n --OH wherein n is an integer of not less than 2. Typical examples of the glycols are, for instance, ethylene glycol, propylene glycol, 1,4-butanediol, and the like. From ethylene glycol is prepared glyoxal, from propylene glycol is prepared methyl glyoxal and from 1,4-butanediol is prepared 1,4-butanedial (1,2-diformyl ethane).
In the present invention, the oxidation-dehydrogenation reaction is carried out at an elevated temperature in a gaseous phase. The reaction is often carried out within a temperature range of 300° to 700° C., particularly from 550° to 650° C. The reaction is carried out in the vicinity of atmospheric pressure, and, generally, a partial pressure of the raw material, glycol is often not more than 0.5 atm. During the reaction, in order to maintain the partial pressure of the glycol at not more than 0.5 atm, steam, nitrogen, carbon dioxide or the mixture thereof is supplied into the reaction system with the glycol.
In this oxidation-dehydrogenation reaction, oxygen is used as an oxidiger. Oxygen gas and air are often used for such oxygen sources. And, usually as much as 1.1 to 2 times of the stoichiometrical amount to the glycol of oxygen is fed. The contacting time of the reacting mixture with the catalyst is within the range of 0.01 to 1 second, and preferably not more than 0.03 second. In the present invention, it is suitable to adopt a fixed catalyst bed. In case of using fixed catalyst bed, it is preferable that the silver particles are packed into a column so as to form multiple layers with different particle size distribution is located on the side of reaction gas inlet and that with the largest particle size distribution on the side of outlet.
In the present invention, it is not absolutely necessary that the catalyst is of silver particles alone. Copper particles can be used along with the silver particles. In such a case, it is preferable that the copper particles are also partially coated with the powder of silicon carbide or silicon nitride. There is no restriction in using a co-catalyst such as phosphorus or phosphorus-containing compounds to prevent C--C bond in glycols (ethylene glycol, etc.) or dialdehyde (glyoxal, etc.) from fusion.
Dialdehydes thus prepared are chemicals with broad use. They are used in amino acid productions as raw materials. They are also synthesized in various agents for fiber or paper processing, and the like.
In the present invention, when the glycols are subjected to oxidation-dehydrogenation in the presence of the silver particles of which the surface is partially coated with the powder of silicon carbide or silicon nitride, the present invention has great advantage in industrial production of dialdehydes.
The present invention is more specifically described and explained by means of the following Examples, in which all % are by weight unless otherwise noted. It is to be understood that the present invention is not limited to the Examples, and various changes and modifications may be made in the invention without departing from the sprit and scope thereof.
EXAMPLE 1
Silver particles partially coated with silicon carbide powder having different particle sizes were packed in a 20 ml stainless steel tube reactor from bottom to top in order of larger particle size. That is, the group of silver particles having a particle size of from 10 to 20 mesh and 0.2%, based on the coated silver particle, of silicon carbide coating was packed by 3.5 ml at the bottom, the group of silver particles having a particle size of from 20 to 40 mesh and 0.5% of silicon carbide coating was packed by 3.2 ml at the second layer, the group of silver particles having a particle size of from 40 to 50 mesh and 0.5% of silicon carbide coating was packed by 3.2 ml at the third layer, and the group of silver particles having a particle size of from 50 to 80 mesh and 0.5% of silicon carbide coating was packed by 0.8 ml at the top.
After being heated and evaporated, ethylene glycol was mixed with nitrogen gas, air and water (in the state of vapor). Then, the gas mixture was supplied to the catalyst bed which was heated to 400° C. Ethylene glycol was fed at the rate of 160 g/h, nitrogen gas was fed at 700 Nl/h, air was fed at 350 Nl/h, and water was fed at 160 g/h.
The reacted gas mixture taken out from the catalyst bed was introduced to a cold trap cooled with dry ice to obtain a product. In this reaction, the conversion of ethylene glycol was 99.9% and the selectivity into glyoxal was 72%.
After 30 days of continuous reaction, the catalyst bed was carefully examined. No sign of sintering was found in any catalyst layer and the catalyst was taken out from the reactor tube without any trouble and was easily pulverized for reuse.
COMPARATIVE EXAMPLE 1
The procedure of Example 1 was repeated except that no coating was applied to the silver catalyst.
The conversion of ethylene glycol was 98.0% and the selectivity into glyoxal was 68%. After 30 days of reaction, the particles of silver catalyst were severely sintered to form a piece of block. It was not easy to take out the catalyst from the reactor tube, and the used catalyst was no longer usable.
EXAMPLE 2
The procedure of Example 1 was repeated except that silicon nitride was used as a coating material of silver particles instead of silicon carbide.
The conversion of ethylene glycol was 99.9% and the selectivity into glyoxal was 74%. There was no sign of sintering in any layer of the catalyst even after 30 days of continuous reaction.
EXAMPLE 3
The procedure of Example 1 was repeated except that propylene glycol was used instead of ethylene glycol.
The conversion of propylene glycol was 99.8% and the selectivity into methyl glyoxal was 78%. There was no sign of sintering in any layer of catalyst even after 30 days of continuous reaction.
EXAMPLES 4 AND 5
The procedure of Example 1 was repeated except that all of the used silver particles (all of four kinds of silver particles in particle size) have 0.2% of silicon carbide coatings (Example 4), or all of the used silver particles have 1.0% of silicon carbide coatings (Example 5).
The conversion of ethylene glycol was 99.9% in Example 4 and 99.8% in Example 5, and the selectivity into glyoxal was 74% in Example 4 and 70% in Example 5.
COMPARATIVE EXAMPLE 2
Silver particles with different particle size were packed in the same reactor tube as used in Example 1 in order of larger size from bottom to top. That is, the group of silver particles having a particle size of from 10 to 20 mesh and no coating was packed by 3.5 ml at the bottom, the group of silver particles having a particle size of from 20 to 40 mesh and 0.5% of silicon carbide coating was packed by 3.2 ml at the second layer, the group of silver particles having a particle size of from 40 to 50 mesh and 0.5% of silicon carbide coating was packed by 2.0 ml at the third layer, and the group of silver particles having a particle size of from 50 to 80 mesh and no coating was packed by 0.8 ml at the top.
Then, the procedure of Example 1 was repeated. The conversion of ethylene glycol was 99.8% and the selectivity into glyoxal was 70%.
After 30 days of continuous reaction, the catalyst bed was carefully examined. The top layer consisting of the silver particles having no coating was suffered from sintering to form a hard plate. The bottom layer consisting of the silver particles, also, having no coating was suffered from sintering to form an aggregated block. On the other hand, there was no sign of sintering in both the second and third layers consisting of the silver particles having the silicon carbide coating.
In addition to the ingredients used in the Examples, other ingredients can be used in the Examples as set forth in the specification to obtain substantially the same results. | A process for preparing a dialdehyde which comprises subjecting a glycol to oxidation-dehydrogenation in the presence of silver particles of which the surface is partially coated with a silicon carbide powder or a silicon nitride powder. According to the present invention, dialdehydes can be prepared from glycols in high conversion of the glycol in high selectivity into the dialdehyde, and the silver catalyst can be reused even if the reaction is stopped in a while since the silver particles are not aggregated during long time operation. | 1 |
SEQUENCE LISTING
[0001] This application contains a sequence listing in paper format and in computer readable format, the teachings and content of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the use of an immunogenic composition comprising a porcine circovirus type 2 (PCV2) antigen for treatment of several clinical manifestations (diseases). Preferably, those clinical manifestations are associated with a PCV2 infection. More particularly, the present invention is concerned with an immunological composition effective for providing an immune response that reduces, or lessens the severity, of the clinical symptoms associated with PCV2 infection. Preferably, the immunological composition comprises a recombinantly produced antigen of PCV2. More preferably, the PCV2 antigen is a recombinantly produced protein encoded by one of the open reading frames (ORFs) in the PCV2 genome. Still more preferably, the antigen is PCV2 ORF2 protein. Most particularly, the present invention is concerned with an immunological composition effective for treatment of clinical symptoms associated with PCV2 infections in swine receiving the immunological composition, and wherein the composition comprises the protein expressed by ORF2 of PCV2. Another aspect of the present invention is the use of any of the compositions provided herewith as a medicament, preferably as a veterinary medicament, even more preferably as a vaccine. Moreover, the present invention also relates to the use of any of the compositions described herein, for the preparation of a medicament for reducing or lessening the severity of clinical symptoms associated with PCV2 infection. Preferably, the medicament is for the prevention of a PCV2 infection, even more preferably in swine. A further aspect of the present invention relates to a process for the production of a medicament, comprising an immunogenic composition of PCV2 for the treatment of several clinical manifestations.
[0004] 2. Description of the Prior Art
[0005] Porcine circovirus type 2 (PCV2) is a small (17-22 nm in diameter), icosahedral, non-enveloped DNA virus, which contains a single-stranded circular genome. PCV2 shares approximately 80% sequence identity with porcine circovirus type 1 (PCV1). However, in contrast with PCV1, which is generally non-virulent, swine infected with PCV2 exhibit a syndrome commonly referred to as Post-weaning Multisystemic Wasting Syndrome (PMWS). PMWS is clinically characterized by wasting, paleness of the skin, unthriftiness, respiratory distress, diarrhea, icterus, and jaundice. In some affected swine, a combination of all symptoms will be apparent while other affected swine will only have one or two of these symptoms. During necropsy, microscopic and macroscopic lesions also appear on multiple tissues and organs, with lymphoid organs being the most common site for lesions. A strong correlation has been observed between the amount of PCV2 nucleic acid or antigen and the severity of microscopic lymphoid lesions. Mortality rates for swine infected with PCV2 can approach 80%. In addition to PMWS, PCV2 has been associated with several other infections including pseudorabies, porcine reproductive and respiratory syndrome (PRRS), Glasser's disease, streptococcal meningitis, salmonellosis, postweaning colibacillosis, dietetic hepatosis, and suppurative bronchopneumonia. However, research thus far has not confirmed whether any of these clinical symptoms are in fact, the direct result of a PCV2 infection. Moreover, it is not yet known whether any of these clinical symptoms can be effectively reduced or cured by an active agent directed against PCV2.
[0006] Current approaches to treat PCV2 infections include DNA-based vaccines, such as those described in U.S. Pat. No. 6,703,023. However, such vaccines have been ineffective at conferring protective immunity against PCV2 infection or reducing, lessening the severity of, or curing any clinical symptoms associated therewith. Moreover, vaccines described in the prior art were focused solely on the prevention of PCV2 infections in swine, but did not consider any further medical use.
[0007] Accordingly, what is needed in the art is an immunogenic composition for the treatment of several clinical manifestations. Further, what is needed in the art is an immunological composition which confers protective immunity against PCV2 infection but which can also be used to treat existing clinical symptoms associated with PCV2 infection.
DISCLOSURE OF THE INVENTION
[0008] The present invention overcomes the problems inherent in the prior art and provides a distinct advance in the state of the art. The present invention provides a medicinal use(s) of immunogenic composition(s) comprising PCV2 antigen.
[0009] In general no adverse events or injection site reactions were noted for any of the PCV2 antigen immunogenic compositions as used herein. Thus, the immunogenic compositions used herein appear to be safe when administered to young pigs, preferably to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV. According to a further embodiment, the immunogenic compositions used herein for any medicinal use described herein, is adminstered to pigs of 3 weeks of age or older, preferably of 2 weeks of age or older, most preferably but not older than 15 weeks of age.
[0010] Unexpectedly, it was found that the therapeutic use of the immunogenic compositions described below, is effective for lessening the severity of various clinical symptoms in swine. In particular, it was discovered that the therapeutic use of the immunogenic compositions of the present invention, and specifically compositions comprising PCV2 ORF2 antigen, is effective for reducing or lessening lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes in swine infected with PCV2. Moreover, the therapeutic use of an antigenic composition, as provided herewith, and that comprises PCV2 antigen, preferably ORF2 antigen, reduces the overall circovirus load and its immunosuppressive impact, thereby resulting in a higher level of general disease resistance and a reduced incidence of PCV-2 associated diseases and symptoms.
[0011] Thus one aspect of the present invention relates to the use of an immunogenic composition comprising PCV2 antigen, preferably recombinant PCV2 antigen, and more preferably PCV2 ORF2 protein as provided herewith, for the preparation of a medicament for the prevention, lessening and/or reduction of lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes in swine. Preferably, said medicament is effective for the prevention, lessening and/or reduction of lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes associated with PCV2 infections in swine. Still more preferably, said medicament is effective for the prevention, lessening and/or reduction of lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes associated with PCV2 infections in pigs, when administered to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, and most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV.
[0012] Another aspect of the present invention relates to a method for the treatment of lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes in swine, comprising the administration of an immunogenic composition as provided herewith, to a pig, said immunogenic composition comprising a PCV2 antigen, preferably a recombinant PCV2 antigen, and more preferably PCV2 ORF2 protein. In yet another aspect, the present invention provides a method for the treatment of lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes associated with a PCV2 infection in swine, comprising the administration of an immunogenic composition as provided herewith, to a pig, said immunogenic composition comprising a PCV2 antigen, preferably a recombinant PCV2 antigen and more preferably PCV2 ORF2 protein. Preferably, said treatment results in the lessening, reduction, prevention, and/or cure of the lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes in swine receiving said immunogenic composition.
[0013] According to a further aspect, said methods for treatment further comprise the administration of said immunogenic composition to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, and most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV.
[0014] It was further discovered that the therapeutic use of an immunogenic composition comprising PCV2 antigen, preferably a recominant PCV2 antigen, and most preferably PCV2 ORF2 protein, as provided herewith, can reduce or lessen lymphadenopathy in combination with one or a multiple of the following symptoms in affected swine: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc.
[0015] Thus one aspect of the present invention relates to the use of an immunogenic composition comprising PCV2 antigen, preferably a recombinant PCV2 antigen and more preferably, PCV2 ORF2 protein as provided herewith, for the preparation of a medicament for the prevention, lessening and/or reduction of lymphadenopathy in combination with one or a multiple of the following symptoms in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc., in pigs. Preferably, said medicament is effective for the prevention, lessening and/or reduction of lymphadenopathy in combination with one or a multiple of the following symptoms associated with PCV2 infection in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc. According to a further aspect, said medicament is effective for the prevention, lessening and/or reduction of lymphadenopathy in combination with one or a multiple of the following symptoms in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc., in pigs, when administered to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, and most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV.
[0016] Moreover, the present invention also relates to a method for the treatment of lymphadenopathy in combination with one or a multiple of the following symptoms in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc., said method comprising the administration of an immunogenic composition comprising PCV2 antigen, preferably a recombinant PCV2 antigen, and more preferably PCV2 ORF2 protein as provided herewith. Preferably, the present invention also relates to a method for the treatment of lymphadenopathy in combination with one or a multiple of the following symptoms associated with PCV2 infection in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc., said method comprising the administration of an immunogenic composition comprising PCV2 antigen, preferably recombinant PCV2 antigen and more preferably PCV2 ORF2 protein, as provided herewith, to a pig. Preferably, said treatment results in the lessening or reduction of the lymphadenopathy, and one or multiple of the following symptoms associated with PCV2 infection in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc. According to a further aspect, said methods for treatment further comprise administration of the immunogenic composition comprising PCV2 antigen, preferably recombinant PCV2 antigen and more preferably PCV2 ORF2 protein, as provided herein, to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, and most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV.
[0017] It was also unexpectedly found that the therapeutic use of an immunogenic composition comprising PCV antigen, preferably recombinant PCV2 antigen and more preferably PCV2 ORF2 protein as provided herewith, can also reduce or lessen Pia like lesions, normally known to be associated with Lawsonia intracellularis infections (Ileitis).
[0018] Thus one aspect of the present invention relates to the use of an immunogenic composition comprising PCV2 antigen, preferably recombinant PCV2 antigen and more preferably PCV2 ORF2 protein as provided herewith, for the preparation of a medicament for the prevention, lessening the severity of and/or reduction of Pia like lesions, normally known to be associated with Lawsonia intracellularis infections in swine. According to a further aspect, said medicament is effective for the prevention, lessening of the severity of and/or reduction of Pia like lesions, normally known to be associated with Lawsonia intracellularis infections, when administered to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, and most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV.
[0019] Moreover, the present invention also relates to a method for the treatment of Pia like lesions, normally known to be associated with Lawsonia intracellularis infections, said method comprising the administration of an immunogenic composition comprising PCV2 antigen, preferably recombinant PCV2 antigen and more preferably PCV2 ORF2 protein as provided herein, to a pig. Preferably, said treatment results in the lessening or reduction of the Pia like lesions, normally known to be associated with Lawsonia intracellularis infections. According to a further aspect, the methods for treatment described above further comprise the administration of the immunogenic composition comprising PCV2 antigen, preferably recombinant PCV2 antigen, and more preferably PCV2 ORF2 protein as provided herein, to pigs not older than 15 weeks of age, more preferably not older than 6 weeks of age, even more preferably not older than 3 weeks, and most preferably not older than 2 weeks. Alternatively, it is preferred that the administration of the immunogenic compositions of the present invention occur within at least 2 and preferably within at least 3 weeks of exposure to virulent PCV.
The Immunogenic Composition
[0020] The immunogenic composition as used herein is effective for inducing an immune response against PCV2 and preventing, reducing and/or lessening the severity of the clinical symptoms associated with PCV2 infection. The composition generally comprises at least one PCV2 antigen.
[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. The term “immunogenic composition” as used herein refers to any pharmaceutical composition containing a PCV2 antigen, which composition can be used to prevent or treat a PCV2 infection-associated disease or condition in a subject. A preferred immunogenic composition can induce, stimulate or enhance the immune response against PCV2. The term thus encompasses both subunit immunogenic compositions, as described below, as well as compositions containing whole killed, or attenuated and/or inactivated PCV2.
[0022] The term “subunit immunogenic composition” as used herein refers to a composition containing at least one immunogenic polypeptide or antigen, but not all antigens, derived from or homologous to an antigen from PCV2. Such a composition is substantially free of intact PCV2. Thus, a “subunit immunogenic composition” is prepared from at least partially purified or fractionated (preferably substantially purified) immunogenic polypeptides from PCV2, or recombinant analogs thereof. A subunit immunogenic composition can comprise the subunit antigen or antigens of interest substantially free of other antigens or polypeptides from PCV2, or in fractionated from. A preferred immunogenic subunit composition comprises the PCV2 ORF2 protein as described below.
[0023] An “immunological or immune response” to a composition or vaccine is the development in the host of a cellular and/or antibody-mediated immune response to the composition or vaccine of interest. Usually, an “immune response” includes but is not limited to one or more of the following effects: the production or activation of antibodies, B cells, helper T cells, suppressor T cells, and/or cytotoxic T cells and/or yd T cells, directed specifically to an antigen or antigens included in the composition or vaccine of interest. Preferably, the host will display either a therapeutic or protective immunological response such that resistance to new infection will be enhanced and/or the clinical severity of the disease reduced. Such protection will be demonstrated by either a reduction in number or severity of, or lack of one or more of the symptoms associated with PCV2 infections as described above.
[0024] The terms “immunogenic” protein or polypeptide or “antigen” as used herein refer to an amino acid sequence which elicits an immunological response as described above. An “immunogenic” protein or polypeptide, as used herein, includes the full-length sequence of any PCV2 proteins, analogs thereof, or immunogenic fragments thereof. The term “immunogenic fragment” refers to a fragment of a protein which includes one or more epitopes and thus elicits the immunological response described above. Such fragments can be identified using any number of epitope mapping techniques, well known in the art. See, e.g., Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66 (Glenn E. Morris, Ed., 1996) Humana Press, Totowa, N.J. For example, linear epitopes may be determined by e.g., concurrently synthesizing large numbers of peptides on solid supports, the peptides corresponding to portions of the protein molecule, and reacting the peptides with antibodies while the peptides are still attached to the supports. Such techniques are known in the art and described in, e.g., U.S. Pat. No. 4,708,871; Geysen et al. (1984) Proc. Natl. Acad. Sci. USA 81:3998-4002; Geysen et al. (1986) Molec. Immunol. 23:709-715. Similarly, conformational epitopes are readily identified by determining spatial conformation of amino acids such as by, e.g., x-ray crystallography and 2-dimensional nuclear magnetic resonance. See, e.g., Epitope Mapping Protocols, supra.
[0025] Synthetic antigens are also included within the definition, for example, polyepitopes, flanking epitopes, and other recombinant or synthetically derived antigens. See, e.g., Bergmann et al. (1993) Eur. J. Immunol. 23:2777-2781; Bergmann et al. (1996), J. Immunol. 157:3242-3249; Suhrbier, A. (1997), Immunol. and Cell Biol. 75:402-408; Gardner et al., (1998) 12th World AIDS Conference, Geneva, Switzerland, Jun. 28-Jul. 3, 1998.
[0026] In a preferred embodiment of the present invention, an immunogenic composition that induces an immune response and, more preferably, confers protective immunity against the clinical signs of PCV2 infection, is provided. The composition most preferably comprises the polypeptide, or a fragment thereof, expressed by ORF2 of PCV2, as the antigenic component of the composition. PCV2 ORF2 DNA and protein, used herein for the preparation of the compositions and within the processes provided herein is a highly conserved domain within PCV2 isolates and thereby, any PCV2 ORF2 would be effective as the source of the PCV ORF2 DNA and/or polypeptide as used herein. A preferred PCV2 ORF2 protein is that of SEQ ID NO. 11. A preferred PCV ORF2 polypeptide is provided herein as SEQ ID NO. 5, but it is understood by those of skill in the art that this sequence could vary by as much as 6-10% in sequence homology and still retain the antigenic characteristics that render it useful in immunogenic compositions. The antigenic characteristics of an immunological composition can be, for example, estimated by the challenge experiment as provided by Example 4. Moreover, the antigenic characteristic of a modified antigen is still retained, when the modified antigen confers at least 70%, preferably 80%, more preferably 90% of the protective immunity as compared to the PCV2 ORF 2 protein, encoded by the polynucleotide sequence of SEQ ID NO:3 or SEQ ID NO:4. An “immunogenic composition” as used herein, means a PCV2 ORF2 protein which elicits an “immunological response” in the host of a cellular and/or antibody-mediated immune response to PCV2 ORF2 protein. Preferably, this immunogenic composition is capable of eliciting or enhancing an immune response against PCV2 thereby conferring protective immunity against PCV2 infection and a reduction in the incidence of, severity of, or prevention of one or more, and preferably all of the clinical signs associated therewith.
[0027] In some forms, immunogenic portions of PCV2 ORF2 protein are used as the antigenic component in the composition. The term “immunogenic portion” as used herein refers to truncated and/or substituted forms, or fragments of PCV2 ORF2 protein and/or polynucleotide, respectively. Preferably, such truncated and/or substituted forms, or fragments will comprise at least 6 contiguous amino acids from the full-length ORF2 polypeptide. More preferably, the truncated or substituted forms, or fragments will have at least 10, more preferably at least 15, and still more preferably at least 19 contiguous amino acids from the full-length ORF2 polypeptide. Two preferred sequences in this respect are provided herein as SEQ ID NOs. 9 and 10. It is further understood that such sequences may be a part of larger fragments or truncated forms.
[0028] A further preferred PCV2 ORF2 polypeptide provided herein is encoded by the nucleotide sequences of SEQ ID NO: 3 or SEQ ID NO: 4. However, it is understood by those of skill in the art that this sequence could vary by as much as 6-20% in sequence homology and still retain the antigenic characteristics that render it useful in immunogenic compositions. In some forms, a truncated or substituted form, or fragment of this PVC2 ORF2 polypeptide is used as the antigenic component in the composition. Preferably, such truncated or substituted forms, or fragments will comprise at least 18 contiguous nucleotides from the full-length ORF2 nucleotide sequence, e.g. of SEQ ID NO: 3 or SEQ ID NO: 4. More preferably, the truncated or substituted forms, or fragments, will have at least 30, more preferably at least 45, and still more preferably at least 57 contiguous nucleotides of the full-length ORF2 nucleotide sequence, e.g. SEQ ID NO: 3 or SEQ ID NO: 4.
[0029] “Sequence Identity” as it is known in the art refers to a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, namely a reference sequence and a given sequence to be compared with the reference sequence. Sequence identity is determined by comparing the given sequence to the reference sequence after the sequences have been optimally aligned to produce the highest degree of sequence similarity, as determined by the match between strings of such sequences. Upon such alignment, sequence identity is ascertained on a position-by-position basis, e.g., the sequences are “identical” at a particular position if at that position, the nucleotides or amino acid residues are identical. The total number of such position identities is then divided by the total number of nucleotides or residues in the reference sequence to give % sequence identity. Sequence identity can be readily calculated by known methods, including but not limited to, those described in Computational Molecular Biology, Lesk, A. N., ed., Oxford University Press, New York (1988), Biocomputing: Informatics and Genome Projects, Smith, D. W., ed., Academic Press, New York (1993); Computer Analysis of Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., eds., Humana Press, New Jersey (1994); Sequence Analysis in Molecular Biology, von Heinge, G., Academic Press (1987); Sequence Analysis Primer, Gribskov, M. and Devereux, J., eds., M. Stockton Press, New York (1991); and Carillo, H., and Lipman, D., SIAM J. Applied Math., 48: 1073 (1988), the teachings of which are incorporated herein by reference. Preferred methods to determine the sequence identity are designed to give the largest match between the sequences tested. Methods to determine sequence identity are codified in publicly available computer programs which determine sequence identity between given sequences. Examples of such programs include, but are not limited to, the GCG program package (Devereux, J., et al., Nucleic Acids Research, 12(1):387 (1984)), BLASTP, BLASTN and FASTA (Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990). The BLASTX program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S. et al., NCVI NLM NIH Bethesda, Md. 20894, Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990), the teachings of which are incorporated herein by reference). These programs optimally align sequences using default gap weights in order to produce the highest level of sequence identity between the given and reference sequences. As an illustration, by a polynucleotide having a nucleotide sequence having at least, for example, 85%, preferably 90%, even more preferably 95% “sequence identity” to a reference nucleotide sequence, it is intended that the nucleotide sequence of the given polynucleotide is identical to the reference sequence except that the given polynucleotide sequence may include up to 15, preferably up to 10, even more preferably up to 5 point mutations per each 100 nucleotides of the reference nucleotide sequence. In other words, in a polynucleotide having a nucleotide sequence having at least 85%, preferably 90%, even more preferably 95% identity relative to the reference nucleotide sequence, up to 15%, preferably 10%, even more preferably 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 15%, preferably 10%, even more preferably 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. These mutations of the reference sequence may occur at the 5′ or 3′ terminal positions of the reference nucleotide sequence or anywhere between those terminal positions, interspersed either individually among nucleotides in the reference sequence or in one or more contiguous groups within the reference sequence. Analogously, by a polypeptide having a given amino acid sequence having at least, for example, 85%, preferably 90%, even more preferably 95% sequence identity to a reference amino acid sequence, it is intended that the given amino acid sequence of the polypeptide is identical to the reference sequence except that the given polypeptide sequence may include up to 15, preferably up to 10, even more preferably up to 5 amino acid alterations per each 100 amino acids of the reference amino acid sequence. In other words, to obtain a given polypeptide sequence having at least 85%, preferably 90%, even more preferably 95% sequence identity with a reference amino acid sequence, up to 15%, preferably up to 10%, even more preferably up to 5% of the amino acid residues in the reference sequence may be deleted or substituted with another amino acid, or a number of amino acids up to 15%, preferably up to 10%, even more preferably up to 5% of the total number of amino acid residues in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the amino or the carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in the one or more contiguous groups within the reference sequence. Preferably, residue positions which are not identical differ by conservative amino acid substitutions. However, conservative substitutions are not included as a match when determining sequence identity.
[0030] “Sequence homology”, as used herein, refers to a method of determining the relatedness of two sequences. To determine sequence homology, two or more sequences are optimally aligned, and gaps are introduced if necessary. However, in contrast to “sequence identity”, conservative amino acid substitutions are counted as a match when determining sequence homology. In other words, to obtain a polypeptide or polynucleotide having 95% sequence homology with a reference sequence, 85%, preferably 90%, even more preferably 95% of the amino acid residues or nucleotides in the reference sequence must match or comprise a conservative substitution with another amino acid or nucleotide, or a number of amino acids or nucleotides up to 15%, preferably up to 10%, even more preferably up to 5% of the total amino acid residues or nucleotides, not including conservative substitutions, in the reference sequence may be inserted into the reference sequence. Preferably the homolog sequence comprises at least a stretch of 50, even more preferably at least 100, even more preferably at least 250, and even more preferably at least 500 nucleotides.
[0031] A “conservative substitution” refers to the substitution of an amino acid residue or nucleotide with another amino acid residue or nucleotide having similar characteristics or properties including size, hydrophobicity, etc., such that the overall functionality does not change significantly.
[0032] “Isolated” means altered “by the hand of man” from its natural state, i.e., if it occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or polypeptide naturally present in a living organism is not “isolated,” but the same polynucleotide or polypeptide separated from the coexisting materials of its natural state is “isolated”, as the term is employed herein.
[0033] Thus, the immunogenic composition as used herein also refers to a composition that comprises PCV2 ORF2 protein, wherein said PCV2 ORF2 protein is anyone of those, described above. Preferably, said PCV2 ORF2 protein is
i) a polypeptide comprising the sequence of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 9, SEQ ID NO: 10 or SEQ ID NO: 11; ii) any polypeptide that is at least 80% homologous to the polypeptide of i), iii) any immunogenic portion of the polypeptides of i) and/or iv) the immunogenic portion of comprising at least 10 contiguous amino acids included in the sequences of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 9, SEQ ID NO: 10 or SEQ ID NO: 11, v) a polypeptide that is encoded by a DNA comprising the sequence of SEQ ID NO: 3 or SEQ ID NO: 4. vi) any polypeptide that is encoded by a polynucleotide that is at least 80% homologous to the polynucleotide of v), vii) any immunogenic portion of the polypeptides encoded by the polynucleotide of v) and/or vi) viii) the immunogenic portion of vii), wherein polynucleotide coding for said immunogenic portion comprises at least 30 contiguous nucleotides included in the sequences of SEQ ID NO: 3, or SEQ ID NO: 4.
[0042] Preferably any of those immunogenic portions have the immunogenic characteristics of PCV2 ORF2 protein that is encoded by the sequence of SEQ ID NO: 3 or SEQ ID NO: 4.
[0043] According to a further aspect, PCV2 ORF2 protein is provided in the immunological composition at an antigen inclusion level effective for inducing the desired immune response, namely reducing the incidence of, lessening the severity of, or preventing one or more clinical signs resulting from PCV2 infection. Preferably, the PCV2 ORF2 protein inclusion level is at least 0.2 μg antigen/ml of the final immunogenic composition (μg/ml), more preferably from about 0.2 to about 400 μg/ml, still more preferably from about 0.3 to about 200 μg/ml, even more preferably from about 0.35 to about 100 μg/ml, still more preferably from about 0.4 to about 50 μg/ml, still more preferably from about 0.45 to about 30 μg/ml, still more preferably from about 0.6 to about 15 μg/ml, even more preferably from about 0.75 to about 8 μg/ml, even more preferably from about 1.0 to about 6 μg/ml, still more preferably from about 1.3 to about 3.0 μg/ml, even more preferably from about 1.4 to about 2.5 μg/ml, even more preferably from about 1.5 to about 2.0 μg/ml, and most preferably about 1.6 μg/ml.
[0044] According to a further aspect, the ORF2 antigen inclusion level is at least 0.2 μg/PCV2 ORF2 protein as described above per dose of the final antigenic composition (μg/dose), more preferably from about 0.2 to about 400 μg/dose, still more preferably from about 0.3 to about 200 μg/dose, even more preferably from about 0.35 to about 100 μg/dose, still more preferably from about 0.4 to about 50 μg/dose, still more preferably from about 0.45 to about 30 μg/dose, still more preferably from about 0.6 to about 15 μg/dose, even more preferably from about 0.75 to about 8 μg/dose, even more preferably from about 1.0 to about 6 μg/dose, still more preferably from about 1.3 to about 3.0 μg/dose, even more preferably from about 1.4 to about 2.5 μg/dose, even more preferably from about 1.5 to about 2.0 μg/dose, and most preferably about 1.6 μg/dose.
[0045] The PCV2 ORF2 polypeptide used in the immunogenic composition in accordance with the present invention can be derived in any fashion including isolation and purification of PCV2 ORF2, standard protein synthesis, and recombinant methodology. Preferred methods for obtaining PCV2 ORF2 polypeptide are provided in U.S. patent application Ser. No. 11/034,797, the teachings and content of which are hereby incorporated by reference. Briefly, susceptible cells are infected with a recombinant viral vector containing PCV2 ORF2 DNA coding sequences, PCV2 ORF2 polypeptide is expressed by the recombinant virus, and the expressed PCV2 ORF2 polypeptide is recovered from the supernate by filtration and inactivated by any conventional method, preferably using binary ethylenimine, which is then neutralized to stop the inactivation process.
[0046] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF2 protein described above, preferably in concentrations described above, and ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, preferably of a recombinant baculovirus. Moreover, the immunogenic composition can comprise i) any of the PCV2 ORF2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, preferably of a recombinant baculovirus, and iii) a portion of the cell culture supernate.
[0047] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, preferably of a recombinant baculovirus, and iii) a portion of the cell culture; wherein about 90% of the components have a size smaller than 1 μm.
[0048] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, iii) a portion of the cell culture, iv) and inactivating agent to inactivate the recombinant viral vector preferably BEI, wherein about 90% of the components i) to have a size smaller than 1 μm. Preferably, BEI is present in concentrations effective to inactivate the baculovirus. Effective concentrations are described above.
[0049] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, iii) a portion of the cell culture, iv) an inactivating agent to inactivate the recombinant viral vector preferably BEI, and v) an neutralization agent to stop the inactivation mediated by the inactivating agent, wherein about 90% of the components i) to have a size smaller than 1 μm. Preferably, if the inactivating agent is BEI, said composition comprises sodium thiosulfate in equivalent amounts to BEI.
[0050] The polypeptide is incorporated into a composition that can be administered to an animal susceptible to PCV2 infection. In preferred forms, the composition may also include additional components known to those of skill in the art (see also Remington's Pharmaceutical Sciences. (1990). 18th ed. Mack Publ., Easton). Additionally, the composition may include one or more veterinary-acceptable carriers. As used herein, “a veterinary-acceptable carrier” includes any and all solvents, dispersion media, coatings, adjuvants, stabilizing agents, diluents, preservatives, antibacterial and antifungal agents, isotonic agents, adsorption delaying agents, and the like. In a preferred embodiment, the immunogenic composition comprises PCV2 ORF2 protein as provided herewith, preferably in concentrations described above, which is mixed with an adjuvant, preferably Carbopol, and physiological saline.
[0051] Those of skill in the art will understand that the composition used herein may incorporate known injectable, physiologically acceptable sterile solutions. For preparing a ready-to-use solution for parenteral injection or infusion, aqueous isotonic solutions, such as e.g. saline or corresponding plasma protein solutions, are readily available. In addition, the immunogenic and vaccine compositions of the present invention can include diluents, isotonic agents, stabilizers, or adjuvants. Diluents can include water, saline, dextrose, ethanol, glycerol, and the like. Isotonic agents can include sodium chloride, dextrose, mannitol, sorbitol, and lactose, among others. Stabilizers include albumin and alkali salts of ethylendiamintetracetic acid, among others.
[0052] “Adjuvants” as used herein, can include aluminum hydroxide and aluminum phosphate, saponins e.g., Quil A, QS-21 (Cambridge Biotech Inc., Cambridge Mass.), GPI-0100 (Galenica Pharmaceuticals, Inc., Birmingham, Ala.), water-in-oil emulsion, oil-in-water emulsion, water-in-oil-in-water emulsion. The emulsion can be based in particular on light liquid paraffin oil (European Pharmacopea type); isoprenoid oil such as squalane or squalene oil resulting from theoligomerization of alkenes, in particular of isobutene or decene; esters of acids or of alcohols containing a linear alkyl group, more particularly plant oils, ethyl oleate, propylene glycol di-(caprylate/caprate), glyceryl tri-(caprylate/caprate) or propylene glycol dioleate; esters of branched fatty acids or alcohols, in particular isostearic acid esters. The oil is used in combination with emulsifiers to form the emulsion. The emulsifiers are preferably nonionic surfactants, in particular esters of sorbitan, of mannide (e.g. anhydromannitol oleate), of glycol, of polyglycerol, of propylene glycol and of oleic, isostearic, ricinoleic or hydroxystearic acid, which are optionally ethoxylated, and polyoxypropylene-polyoxyethylene copolymer blocks, in particular the Pluronic products, especially L121. See Hunter et al., The Theory and Practical Application of Adjuvants (Ed. Stewart-Tull, D. E. S.). John Wiley and Sons, NY, pp51-94 (1995) and Todd et al., Vaccine 15:564-570 (1997).
[0053] For example, it is possible to use the SPT emulsion described on page 147 of “Vaccine Design, The Subunit and Adjuvant Approach” edited by M. Powell and M. Newman, Plenum Press, 1995, and the emulsion MF59 described on page 183 of this same book.
[0054] A further instance of an adjuvant is a compound chosen from the polymers of acrylic or methacrylic acid and the copolymers of maleic anhydride and alkenyl derivative. Advantageous adjuvant compounds are the polymers of acrylic or methacrylic acid which are cross-linked, especially with polyalkenyl ethers of sugars or polyalcohols. These compounds are known by the term carbomer (Phameuropa Vol. 8, No. 2, June 1996). Persons skilled in the art can also refer to U.S. Pat. No. 2,909,462 which describes such acrylic polymers cross-linked with a polyhydroxylated compound having at least 3 hydroxyl groups, preferably not more than 8, the hydrogen atoms of at least three hydroxyls being replaced by unsaturated aliphatic radicals having at least 2 carbon atoms. The preferred radicals are those containing from 2 to 4 carbon atoms, e.g. vinyls, allyls and other ethylenically unsaturated groups. The unsaturated radicals may themselves contain other substituents, such as methyl. The products sold under the name Carbopol; (BF Goodrich, Ohio, USA) are particularly appropriate. They are cross-linked with an allyl sucrose or with allyl pentaerythritol. Among them, there may be mentioned Carbopol 974P, 934P and 971P. Most preferred is the use of Carbopol, in particular the use of Carbopol 971P, preferably in amounts of about 500 μg to about 5 mg per dose, even more preferred in an amount of about 750 μg to about 2.5 mg per dose and most preferred in an amount of about 1 mg per dose.
[0055] Further suitable adjuvants include, but are not limited to, the RIBI adjuvant system (Ribi Inc.), Block co-polymer (CytRx, Atlanta Ga.), SAF-M (Chiron, Emeryville Calif.), monophosphoryl lipid A, Avridine lipid-amine adjuvant, heat-labile enterotoxin from E. coli (recombinant or otherwise), cholera toxin, IMS 1314, or muramyl dipeptide among many others.
[0056] Preferably, the adjuvant is added in an amount of about 100 μg to about 10 mg per dose. Even more preferably, the adjuvant is added in an amount of about 100 μg to about 10 mg per dose. Even more preferably, the adjuvant is added in an amount of about 500 μg to about 5 mg per dose. Even more preferably, the adjuvant is added in an amount of about 750 μg to about 2.5 mg per dose. Most preferably, the adjuvant is added in an amount of about 1 mg per dose.
[0057] Additionally, the composition can include one or more pharmaceutical-acceptable carriers. As used herein, “a pharmaceutical-acceptable carrier” includes any and all solvents, dispersion media, coatings, stabilizing agents, diluents, preservatives, antibacterial and antifungal agents, isotonic agents, adsorption delaying agents, and the like. Most preferably, the composition provided herewith, contains PCV2 ORF2 protein recovered from the supernate of in vitro cultured cells, wherein said cells were infected with a recombinant viral vector containing PCV2 ORF2 DNA and expressing PCV2 ORF2 protein, and wherein said cell culture was treated with about 2 to about 8 mM BEI, preferably with about 5 mM BEI to inactivate the viral vector, and an equivalent concentration of a neutralization agent, preferably sodium thiosulfate solution to a final concentration of about 2 to about 8 mM, preferably of about 5 mM.
[0058] The present invention also relates to an immunogenic composition that comprises i) any of the PCV2 ORF2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, iii) a portion of the cell culture, iv) an inactivating agent to inactivate the recombinant viral vector preferably BEI, and v) an neutralization agent to stop the inactivation mediated by the inactivating agent, preferably sodium thiosulfate in equivalent amounts to BEI; and vi) a suitable adjuvant, preferably Carbopol 971 in amounts described above; wherein about 90% of the components i) to have a size smaller than 1 μm. According to a further aspect, this immunogenic composition further comprises a pharmaceutical acceptable salt, preferably a phosphate salt in physiologically acceptable concentrations. Preferably, the pH of said immunogenic composition is adjusted to a physiological pH, meaning between about 6.5 and 7.5.
[0059] The immunogenic composition as used herein also refers to a composition that comprises per one ml i) at least 1.6 μg of PCV2 ORF2 protein described above, ii) at least a portion of baculovirus expressing said PCV2 ORF2 protein iii) a portion of the cell culture, iv) about 2 to 8 mM BEI, v) sodium thiosulfate in equivalent amounts to BEI; and vi) about 1 mg Carbopol 971, and vii) phosphate salt in a physiologically acceptable concentration; wherein about 90% of the components i) to have a size smaller than 1 μm and the pH of said immunogenic composition is adjusted to about 6.5 to 7.5.
[0060] The immunogenic compositions can further include one or more other immunomodulatory agents such as, e. g., interleukins, interferons, or other cytokines. The immunogenic compositions can also include Gentamicin and Merthiolate. While the amounts and concentrations of adjuvants and additives useful in the context of the present invention can readily be determined by the skilled artisan, the present invention contemplates compositions comprising from about 50 μg to about 2000 μg of adjuvant and preferably about 250 μg/ml dose of the vaccine composition. Thus, the immunogenic composition as used herein also refers to a composition that comprises from about 1 μg/ml to about 60 μg/ml of antibiotics, and more preferably less than about 30 μg/ml of antibiotics.
[0061] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF2 protein, iii) a portion of the cell culture, iv) an inactivating agent to inactivate the recombinant viral vector preferably BEI, and v) an neutralization agent to stop the inactivation mediated by the inactivating agent, preferably sodium thiosulfate in equivalent amounts to BEI; vi) a suitable adjuvant, preferably Carbopol 971 in amounts described above; vii) a pharmaceutical acceptable concentration of a saline buffer, preferably of a phosphate salt, and viii) an anti-microbiological active agent; wherein about 90% of the components i) to have a size smaller than 1 μm.
[0062] It has been surprisingly found, that the immunogenic composition comprising the PCV2 ORF2 protein was highly stable over a period of 24 months. It has also been found the immunogenic compositions are very effective in reducing the clinical symptoms associated with PCV2 infections. It was also discovered, that the immunogenic compositions comprising the recombinant baculovirus expressed PCV2 ORF2 protein as described above, are surprisingly more effective than an immunogenic composition comprising the whole PCV2 virus in an inactivated form, or isolated viral PCV2 ORF2 antigen. In particular, it has been surprisingly found, that the recombinant baculovirus expressed PCV2 ORF2 protein is effective in very low concentrations, which means in concentrations up to 0.25 μg/dose. This unexpected high immunogenic potential of the PCV2 ORF2 protein is increased by Carbopol. Examples 1 to 3 disclose in detail the production of PCV2 ORF2 comprising immunogenic compositions.
[0063] The immunogenic composition as used herein also refers to Ingelvac® CircoFLEX™ (Boehringer Ingelheim Vetmedica, Inc., St Joseph, Mo., USA), CircoVac® (Merial SAS, Lyon, France), CircoVent (Intervet Inc., Millsboro, Del., USA), or Suvaxyn PCV-2 One Dose® (Fort Dodge Animal Health, Kansas City, Kans., USA).
Administration of the Immunogenic Composition
[0064] The composition according to the invention may be applied intradermally, intratracheally, or intravaginally. The composition preferably may be applied intramuscularly or intranasally, most preferably intramuscularlly. In an animal body, it can prove advantageous to apply the pharmaceutical compositions as described above via an intravenous or by direct injection into target tissues. For systemic application, the intravenous, intravascular, intramuscular, intranasal, intraarterial, intraperitoneal, oral, or intrathecal routes are preferred. A more local application can be effected subcutaneously, intradermally, intracutaneously, intracardially, intralobally, intramedullarly, intrapulmonarily or directly in or near the tissue to be treated (connective-, bone-, muscle-, nerve-, epithelial tissue). Depending on the desired duration and effectiveness of the treatment, the compositions according to the invention may be administered once or several times, also intermittently, for instance on a daily basis for several days, weeks or months and in different dosages.
[0065] Preferably, at least one dose of the immunogenic compositions as described above is intramuscularly administered to the subject in need thereof. According to a further aspect, the PCV-2 antigen or the immunogenic composition comprising any such PCV-2 antigen as described above is formulated and administered in one (1) mL per dose. Thus, according to a further aspect, the present invention also relates to a 1 ml immunogenic composition, comprising PCV-2 antigen as described herein, for reducing or lessening lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes in pigs infected with PCV2.
[0066] According to a further aspect, according to a further aspect, the present invention also relates to a 1 ml immunogenic composition, comprising PCV-2 antigen as described herein, for reducing or lessening lymphadenopathy in combination with one or a multiple of the following symptoms in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies.
[0067] According to a further aspect, at least one further administration of at least one dose of the immunogenic composition as described above is given to a subject in need thereof, wherein the second or any further administration is given at least 14 days beyond the initial or any former administrations. Preferably, the immunogenic composition is administered with an immune stimulant. Preferably, said immune stimulant is given at least twice. Preferably, at least 3 days, more preferably at least 5 days, even more preferably at least 7 days are in between the first and the second or any further administration of the immune stimulant. Preferably, the immune stimulant is given at least 10 days, preferably 15 days, even more preferably 20, even more preferably at least 22 days beyond the initial administration of the immunogenic composition provided herein. A preferred immune stimulant is, for example, keyhole limpet hemocyanin (KLH), preferably emulsified with incomplete Freund's adjuvant (KLH/ICFA). However, it is herewith understood, that any other immune stimulant known to a person skilled in the art can also be used. The term “immune stimulant” as used herein, means any agent or composition that can trigger the immune response, preferably without initiating or increasing a specific immune response, for example the immune response against a specific pathogen. It is further instructed to administer the immune stimulant in a suitable dose.
[0068] Moreover, it has also been surprisingly found that the immunogenic potential of the immunogenic compositions used herein, preferably those that comprise recombinant baculovirus expressed PCV2 ORF2 protein, even more preferably in combination with Carbopol, can be further confirmed by the administration of the IngelVac PRRS MLV vaccine (see Example 5). PCV2 clinical signs and disease manifestations are greatly magnified when PRRS infection is present. However, the immunogenic compositions and vaccination strategies as provided herewith lessened this effect greatly, and more than expected. In other words, an unexpected synergistic effect was observed when animals, preferably piglets were treated with any of the PCV2 ORF2 immunogenic compositions, as provided herewith, and the Ingelvac PRRS MLV vaccine (Boehringer Ingelheim).
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] FIG. 1 is a schematic flow diagram of a preferred construction of PCV2 ORF2 recombinant baculovirus; and
[0070] FIGS. 2 a and 2 b are each schematic flow diagrams of how to produce one of the compositions used in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0071] The following examples set forth preferred materials and procedures in accordance with the present invention. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods, devices, and materials are now described. It is to be understood, however, that these examples are provided by way of illustration only, and nothing therein should be deemed a limitation upon the overall scope of the invention.
Example 1
[0072] This example compares the relative yields of ORF2 using methods of the present invention with methods that are known in the prior art. Four 1000 mL spinner flasks were each seeded with approximately 1.0×10 6 Sf+ cells/ml in 300 mL of insect serum free media, Excell 420 (JRH Biosciences, Inc., Lenexa, Kans.). The master cell culture is identified as SF+( Spodoptera frugiperda ) Master Cell Stock, passage 19, Lot#N112-095W. The cells used to generate the SF+ Master Cell Stock were obtained from Protein Sciences Corporation, Inc., Meriden, Conn. The SF+ cell line for this example was confined between passages 19 and 59. Other passages will work for purposes of the present invention, but in order to scale the process up for large scale production, at least 19 passages will probably be necessary and passages beyond 59 may have an effect on expression, although this was not investigated. In more detail, the initial SF+ cell cultures from liquid nitrogen storage were grown in Excell 420 media in suspension in sterile spinner flasks with constant agitation. The cultures were grown in 100 mL to 250 mL spinner flasks with 25 to 150 mL of Excell 420 serum-free media. When the cells had multiplied to a cell density of 1.0-8.0×10 6 cells/mL, they were split to new vessels with a planting density of 0.5-1.5×10 6 cells/mL. Subsequent expansion cultures were grown in spinner flasks up to 36 liters in size or in stainless steel bioreactors of up to 300 liters for a period of 2-7 days at 25-29° C.
[0073] After seeding, the flasks were incubated at 27° C. for four hours. Subsequently, each flask was seeded with a recombinant baculovirus containing the PCV2 ORF2 gene (SEQ ID NO: 4). The recombinant baculovirus containing the PCV2 ORF2 gene was generated as follows: the PCV2 ORF2 gene from a North American strain of PCV2 was PCR amplified to contain a 5′ Kozak's sequence (SEQ ID NO: 1) and a 3′ EcoR1 site (SEQ ID NO: 2), and cloned into the pGEM-T-Easy vector (Promega, Madison, Wis.). Then, it was subsequently excised and subcloned into the transfer vector pVL1392 (BD Biosciences Pharmingen, San Diego, Calif.). The subcloned portion is represented herein as SEQ ID NO: 7. The pVL1392 plasmid containing the PCV2 ORF2 gene was designated N47-064Y and then co-transfected with BaculoGold® (BD Biosciences Pharmingen) baculovirus DNA into Sf+ insect cells (Protein Sciences, Meriden, Conn.) to generate the recombinant baculovirus containing the PCV2 ORF2 gene. The new construct is provided herein as SEQ ID NO: 8. The recombinant baculovirus containing the PCV2 ORF2 gene was plaque-purified and Master Seed Virus (MSV) was propagated on the SF+ cell line, aliquotted, and stored at −70° C. The MSV was positively identified as PCV2 ORF2 baculovirus by PCR-RFLP using baculovirus specific primers. Insect cells infected with PCV2 ORF2 baculovirus to generate MSV or Working Seed Virus express PCV2 ORF2 antigen as detected by polyclonal serum or monoclonal antibodies in an indirect fluorescent antibody assay. Additionally, the identity of the PCV2 ORF2 baculovirus was confirmed by N-terminal amino acid sequencing. The PCV2 ORF2 baculovirus MSV was also tested for purity in accordance with 9 C.F.R. 113.27 (c), 113.28, and 113.55. Each recombinant baculovirus seeded into the spinner flasks had varying multiplicities of infection (MOIs). Flask 1 was seeded with 7.52 mL of 0.088 MOI seed; flask 2 was seeded with 3.01 mL of 0.36MOI seed; flask 3 was seeded with 1.5 mL of 0.18MOI seed; and flask 4 was seeded with 0.75 mL of 0.09MOI seed. A schematic flow diagram illustrating the basic steps used to construct a PCV2 ORF2 recombinant baculovirus is provided herein as FIG. 1 .
[0074] After being seeded with the baculovirus, the flasks were then incubated at 27±2° C. for 7 days and were also agitated at 100 rpm during that time. The flasks used ventilated caps to allow for air flow. Samples from each flask were taken every 24 hours for the next 7 days. After extraction, each sample was centrifuged, and both the pellet and the supernatant were separated and then microfiltered through a 0.45-1.0 μm pore size membrane.
[0075] The resulting samples then had the amount of ORF2 present within them quantified via an ELISA assay. The ELISA assay was conducted with capture antibody Swine anti-PCV2 Pab IgG Prot. G purified (diluted 1:250 in PBS) diluted to 1:6000 in 0.05M Carbonate buffer (pH 9.6). 100 μL of the antibody was then placed in the wells of the mictrotiter plate, sealed, and incubated overnight at 37° C. The plate was then washed three times with a wash solution which comprised 0.5 mL of Tween 20 (Sigma, St. Louis, Mo.), 100 mL of 10×D-PBS (Gibco Invitrogen, Carlsbad, Calif.) and 899.5 mL of distilled water. Subsequently, 250 μL of a blocking solution (5 g Carnation Non-fat dry milk (Nestle, Glendale, Calif.) in 10 mL of D-PBS QS to 100 mL with distilled water) was added to each of the wells. The next step was to wash the test plate and then add pre-diluted antigen. The pre-diluted antigen was produced by adding 200 μL of diluent solution (0.5 mL Tween 20 in 999.5 mL D-PBS) to each of the wells on a dilution plate. The sample was then diluted at a 1:240 ratio and a 1:480 ratio, and 100 μL of each of these diluted samples was then added to one of the top wells on the dilution plate (i.e. one top well received 100 μL of the 1:240 dilution and the other received 100 μL of the 1:480 dilution). Serial dilutions were then done for the remainder of the plate by removing 100 μL form each successive well and transferring it to the next well on the plate. Each well was mixed prior to doing the next transfer. The test plate washing included washing the plate three times with the wash buffer. The plate was then sealed and incubated for an hour at 37° C. before being washed three more times with the wash buffer. The detection antibody used was monoclonal antibody to PCV ORF2. It was diluted to 1:300 in diluent solution, and 100 μL of the diluted detection antibody was then added to the wells. The plate was then sealed and incubated for an hour at 37° C. before being washed three times with the wash buffer. Conjugate diluent was then prepared by adding normal rabbit serum (Jackson Immunoresearch, West Grove, Pa.) to the diluent solution to 1% concentration. Conjugate antibody Goat anti-mouse (H+1)-HRP (Jackson Immunoresearch) was diluted in the conjugate diluent to 1:10,000. 100 μL of the diluted conjugate antibody was then added to each of the wells. The plate was then sealed and incubated for 45 minutes at 37° C. before being washed three times with the wash buffer. 100 μL of substrate (TMB Peroxidase Substrate, Kirkgaard and Perry Laboratories (KPL), Gaithersberg, Md.), mixed with an equal volume of Peroxidase Substrate B (KPL) was added to each of the wells. The plate was incubated at room temperature for 15 minutes. 100 μL of 1N HCL solution was then added to all of the wells to stop the reaction. The plate was then run through an ELISA reader. The results of this assay are provided in Table 1 below:
[0000]
TABLE 1
ORF2 in
ORF2 in
Day
Flask
pellet (μg)
supernatant (μg)
3
1
47.53
12
3
2
57.46
22
3
3
53.44
14
3
4
58.64
12
4
1
43.01
44
4
2
65.61
62
4
3
70.56
32
4
4
64.97
24
5
1
31.74
100
5
2
34.93
142
5
3
47.84
90
5
4
55.14
86
6
1
14.7
158
6
2
18.13
182
6
3
34.78
140
6
4
36.88
146
7
1
6.54
176
7
2
12.09
190
7
3
15.84
158
7
4
15.19
152
[0076] These results indicate that when the incubation time is extended, expression of ORF2 into the supernatant of the centrifuged cells and media is greater than expression in the pellet of the centrifuged cells and media. Accordingly, allowing the ORF2 expression to proceed for at least 5 days and recovering it in the supernate rather than allowing expression to proceed for less than 5 days and recovering ORF2 from the cells, provides a great increase in ORF2 yields, and a significant improvement over prior methods.
Example 2
[0077] This example provides data as to the efficacy of the invention claimed herein. A 1000 mL spinner flask was seeded with approximately 1.0×10 6 Sf+ cells/ml in 300 mL of Excell 420 media. The flask was then incubated at 27° C. and agitated at 100 rpm. Subsequently, the flask was seeded with 10 mL of PCV2 ORF2/Bac p+6 (the recombinant baculovirus containing the PCV2 ORF2 gene passaged 6 additional times in the Sf9 insect cells) virus seed with a 0.1 MOI after 24 hours of incubation.
[0078] The flask was then incubated at 27° C. for a total of 6 days. After incubation, the flask was then centrifuged and three samples of the resulting supernatant were harvested and inactivated. The supernatant was inactivated by bringing its temperature to 37±2° C. To the first sample, a 0.4M solution of 2-bromoethyleneamine hydrobromide which had been cyclized to 0.2M binary ethlylenimine (BEI) in 0.3N NaOH was added to the supernatant to give a final concentration of BEI of 5 mM. To the second sample, 10 mM BEI was added to the supernatant. To the third sample, no BEI was added to the supernatant. The samples were then stirred continuously for 48 hrs. A 1.0 M sodium thiosulfate solution to give a final minimum concentration of 5 mM was added to neutralize any residual BEI. The quantity of ORF2 in each sample was then quantified using the same ELISA assay procedure as described in Example 1. The results of this may be seen in Table 2 below:
[0000]
TABLE 2
Sample
ORF2 in supernatant (μg)
1
78.71
2
68.75
3
83.33
[0079] This example demonstrates that neutralization with BEI does not remove or degrade significant amounts of the recombinant PCV2 ORF2 protein product. This is evidenced by the fact that there is no large loss of ORF2 in the supernatant from the BEI or elevated temperatures. Those of skill in the art will recognize that the recovered ORF2 is a stable protein product.
Example 3
[0080] This example demonstrates that the present invention is scalable from small scale production of recombinant PCV2 ORF2 to large scale production of recombinant PCV2 ORF2. 5.0×10 5 cells/ml of SF+ cells/ml in 7000 mL of ExCell 420 media was planted in a 20000 mL Applikon Bioreactor. The media and cells were then incubated at 27° C. and agitated at 100RPM for the next 68 hours. At the 68 th hour, 41.3 mL of PCV2 ORF2 Baculovirus MSV+3 was added to 7000 mL of ExCell 420 medium. The resultant mixture was then added to the bioreactor. For the next seven days, the mixture was incubated at 27° C. and agitated at 100RPM. Samples from the bioreactor were extracted every 24 hours beginning at day 4, post-infection, and each sample was centrifuged. The supernatant of the samples were preserved and the amount of ORF2 was then quantified using SDS-PAGE densitometry. The results of this can be seen in Table 3 below:
[0000]
TABLE 3
Day after infection:
ORF2 in supernatant (μg/mL)
4
29.33
5
41.33
6
31.33
7
60.67
Example 4
[0081] This example tests the efficacy of seven PCV2 candidate vaccines and further defines efficacy parameters following exposure to a virulent strain of PCV2. One hundred and eight (108) cesarean derived colostrum deprived (CDCD) piglets, 9-14 days of age, were randomly divided into 9 groups of equal size. Table 4 sets forth the General Study Design for this Example
[0000]
TABLE 4
General Study Design
Challenged
KLH/ICFA
with
on Day 21
Virulent
Necropsy
No. Of
Day of
and
PCV2 on
on
Group
Pigs
Treatment
Treatment
Day 27
Day 24
Day 49
1
12
PCV2 Vaccine No. 1-
0
+
+
+
(vORF2 16 μg)
2
12
PCV2 Vaccine No. 2-
0
+
+
+
(vORF2 8 μg)
3
12
PCV2 Vaccine No. 3-
0
+
+
+
(vORF2 4 μg)
4
12
PCV2 Vaccine No. 4-
0
+
+
+
(rORF2 16 μg)
5
12
PCV2 Vaccine No. 5-
0
+
+
+
(rORF2 8 μg)
6
12
PCV2 Vaccine No. 6-
0
+
+
+
(rORF2 4 μg)
7
12
PCV2 Vaccine No. 7-
0
+
+
+
(Killed whole cell virus)
8
12
None-Challenge Controls
N/A
+
+
+
9
12
None-Strict Negative
N/A
+
−
+
Control Group
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
[0082] Seven of the groups (Groups 1-7) received doses of PCV2 ORF2 polypeptide, one of the groups acted as a challenge control and received no PCV2 ORF2, and another group acted as the strict negative control group and also received no PCV2 ORF2. On Day 0, Groups 1 through 7 were treated with assigned vaccines. Piglets in Group 7 were given a booster treatment on Day 14. Piglets were observed for adverse events and injection site reactions following vaccination and on Day 19, piglets were moved to the second study site. At the second study site, Groups 1-8 were group housed in one building while Group 9 was housed in a separate building. All pigs received keyhole limpet hemocyanin (KLH)/incomplete Freund's adjuvant (ICFA) on Days 21 and 27 and on Day 24, Groups 1-8 were challenged with a virulent PCV2.
[0083] Pre- and post-challenge, blood samples were collected for PCV2 serology. Post-challenge, body weight data for determination of average daily weight gain (ADWG), and clinical symptoms, as well as nasal swab samples to determine nasal shedding of PCV2, were collected. On Day 49, all surviving pigs were necropsied, lungs were scored for lesions, and selected tissues were preserved in formalin for Immunohistochemistry (IHC) testing at a later date.
Materials and Methods
[0084] This was a partially blinded vaccination-challenge feasibility study conducted in CDCD pigs, 9 to 14 days of age on Day 0. To be included in the study, PCV2 IFA titers of sows were ≦1:1000. Additionally, the serologic status of sows were from a known PRRS-negative herd. Twenty-eight (28) sows were tested for PCV2 serological status. Fourteen (14) sows had a PCV2 titer of ≦1000 and were transferred to the first study site. One hundred ten (110) piglets were delivered by cesarean section surgeries and were available for this study on Day −4. On Day −3, 108 CDCD pigs at the first study site were weighed, identified with ear tags, blocked by weight and randomly assigned to 1 of 9 groups, as set forth above in table 4. If any test animal meeting the inclusion criteria was enrolled in the study and was later excluded for any reason, the Investigator and Monitor consulted in order to determine the use of data collected from the animal in the final analysis. The date of which enrolled piglets were excluded and the reason for exclusion was documented. Initially, no sows were excluded. A total of 108 of an available 110 pigs were randomly assigned to one of 9 groups on Day −3. The two smallest pigs (Nos. 17 and 19) were not assigned to a group and were available as extras, if needed. During the course of the study, several animals were removed. Pig 82 (Group 9) on Day −1, Pig No. 56 (Group 6) on Day 3, Pig No. 53 (Group 9) on Day 4, Pig No. 28 (Group 8) on Day 8, Pig No. 69 (Group 8) on Day 7, and Pig No. 93 (Group 4) on Day 9, were each found dead prior to challenge. These six pigs were not included in the final study results. Pig no 17 (one of the extra pigs) was assigned to Group 9. The remaining extra pig, No. 19, was excluded from the study.
[0085] The formulations given to each of the groups were as follows: Group 1 was designed to administer 1 ml of viral ORF2 (vORF2) containing 16 μg ORF2/ml. This was done by mixing 10.24 ml of viral ORF2 (256 μg/25 μg/ml=10.24 ml vORF2) with 3.2 ml of 0.5% Carbopol and 2.56 ml of phosphate buffered saline at a pH of 7.4. This produced 16 ml of formulation for group 1. Group 2 was designed to administer 1 ml of vORF2 containing 8 μg vORF2/ml. This was done by mixing 5.12 ml of vORF2 (128 μg/25 μg/ml=5.12 ml vORF2) with 3.2 ml of 0.5% Carbopol and 7.68 ml of phosphate buffered saline at a pH of 7.4. This produced 16 ml of formulation for group 2. Group 3 was designed to administer 1 ml of vORF2 containing 4 μg vORF2/ml. This was done by mixing 2.56 ml of vORF2 (64 μg/25 μg/ml=2.56 ml vORF2) with 3.2 ml of 0.5% Carbopol and 10.24 ml of phosphate buffered saline at a pH of 7.4. This produced 16 ml of formulation for group 3. Group 4 was designed to administer 1 ml of recombinant ORF2 (rORF2) containing 16 μg rORF2/ml. This was done by mixing 2.23 ml of rORF2 (512 μg/230 μg/ml=2.23 ml rORF2) with 6.4 ml of 0.5% Carbopol and 23.37 ml of phosphate buffered saline at a pH of 7.4. This produced 32 ml of formulation for group 4. Group 5 was designed to administer 1 ml of rORF2 containing 8 μg rORF2/ml. This was done by mixing 1.11 ml of rORF2 (256 μg/230 μg/ml=1.11 ml rORF2) with 6.4 ml of 0.5% Carbopol and 24.49 ml of phosphate-buffered saline at a pH of 7.4. This produced 32 ml of formulation for group 5. Group 6 was designed to administer 1 ml of rORF2 containing 8 μg rORF2/ml. This was done by mixing 0.56 ml of rORF2 (128 μg/230 μg/ml=0.56 ml rORF2) with 6.4 ml of 0.5% Carbopol and 25.04 ml of phosphate buffered saline at a pH of 7.4. This produced 32 ml of formulation for group 6. Group 7 was designed to administer 2 ml of PCV2 whole killed cell vaccine (PCV2 KV) containing the MAX PCV2 KV. This was done by mixing 56 ml of PCV2 KV with 14 ml of 0.5% Carbopol. This produced 70 ml of formulation for group 7. Finally group 8 was designed to administer KLH at 0.5 μg/ml or 1.0 μg/ml per 2 ml dose. This was done by mixing 40.71 ml KLH (7.0 μg protein/ml at 0.5 μg/ml=570 ml (7.0 μg/ml)(×)=(0.5)(570 ml)), 244.29 ml phosphate buffered saline at a pH of 7.4, and 285 ml Freunds adjuvant. Table 5 describes the time frames for the key activities of this Example
[0000]
TABLE 5
Study Activities
Study Day
Study Activity
−4, 0 to 49
General observations for overall health and clinical symptoms
−3
Weighed; Randomized to groups; Collected blood samples
from all pigs
0
Health examination; Administered IVP Nos. 1-7 to Groups
1-7, respectively
0-7
Observed pigs for injection site reactions
14
Boostered Group 7 with PCV2 Vaccine No. 7; Blood samples
from all pigs
14-21
Observed Group 7 for injection site reactions
16-19
Treated all pigs with antibiotics (data missing)
19
Pigs transported from the first test site to a second test site
21
Treated Groups 1-9 with KLH/ICFA
24
Collected blood and nasal swab samples from all pigs;
Weighed all pigs; Challenged Groups 1-8 with PCV2
challenge material
25, 27,
Collected nasal swab samples from all pigs
29, 31,
33, 35,
37, 39,
41, 43,
45, 47
27
Treated Groups 1-9 with KLH/ICFA
31
Collected blood samples from all pigs
49
Collected blood and nasal swab samples from all pigs;
Weighed all pigs; Necropsy all pigs; Gross lesions noted with
emphasis placed on icterus and gastric ulcers; Lungs
evaluated for lesions; Fresh and formalin fixed tissue samples
saved; In-life phase of the study completed
[0086] Following completion of the in-life phase of the study, formalin fixed tissues were examined by Immunohistochemistry (IHC) for detection of PCV2 antigen by a pathologist, blood samples were evaluated for PCV2 serology, nasal swab samples were evaluated for PCV2 shedding, and average daily weight gain (ADWG) was determined from Day 24 to Day 49.
[0087] Animals were housed at the first study site in individual cages in five rooms from birth to approximately 11 days of age (approximately Day 0 of the study). Each room was identical in layout and consisted of stacked individual stainless steel cages with heated and filtered air supplied separately to each isolation unit. Each room had separate heat and ventilation, thereby preventing cross-contamination of air between rooms. Animals were housed in two different buildings at the second study site. Group 9 (The Strict negative control group) was housed separately in a converted finisher building and Groups 1-8 were housed in converted nursery building. Each group was housed in a separate pen (11-12 pigs per pen) and each pen provided approximately 3.0 square feet per pig. Each pen was on an elevated deck with plastic slatted floors. A pit below the pens served as a holding tank for excrement and waste. Each building had its own separate heating and ventilation systems, with little likelihood of cross-contamination of air between buildings.
[0088] At the first study site, piglets were fed a specially formulated milk ration from birth to approximately 3 weeks of age. All piglets were consuming solid, special mixed ration by Day 19 (approximately 4½ weeks of age). At the second study site, all piglets were fed a custom non-medicated commercial mix ration appropriate for their age and weight, ad libitum. Water at both study sites was also available ad libitum.
[0089] All test pigs were treated with Vitamin E on Day −2, with iron injections on Day −1 and with NAXCEL® (1.0 mL, IM, in alternating hams) on Days 16, 17, 18 and 19. In addition, Pig No. 52 (Group 9) was treated with an iron injection on Day 3, Pig 45 (Group 6) was treated with an iron injection on Day 11, Pig No. 69 (Group 8) was treated with NAXCEL® on Day 6, Pig No. 74 (Group 3) was treated with dexamethazone and penicillin on Day 14, and Pig No. 51 (Group 1) was treated with dexamethazone and penicillin on Day 13 and with NAXCEL® on Day 14 for various health reasons.
[0090] While at both study sites, pigs were under veterinary care Animal health examinations were conducted on Day 0 and were recorded on the Health Examination Record Form. All animals were in good health and nutritional status before vaccination as determined by observation on Day 0. All test animals were observed to be in good health and nutritional status prior to challenge. Carcasses and tissues were disposed of by rendering. Final disposition of study animals was records on the Animal Disposition Record.
[0091] On Day 0, pigs assigned to Groups 1-6 received 1.0 mL of PCV2 Vaccines 1-6, respectively, IM in the left neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×½″ needle. Pigs assigned to Group 7 received 2.0 mL of PCV2 Vaccine No. 7 IM in the left neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×½″ needle. On Day 14, pigs assigned to Group 7 received 2.0 mL of PCV2 Vaccine No. 7 IM in the right neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×½″ needle.
[0092] On Day 21 all test pigs received 2.0 mL of KLH/ICFA IM in the right ham region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×1″ needle. On Day 27 all test pigs received 2.0 mL of KLH/ICFA in the left ham region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×1″ needle.
[0093] On Day 24, pigs assigned to Groups 1-8 received 1.0 mL of PCV2 ISUVDL challenge material (5.11 log 10 TCID 50 /mL) IM in the left neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×1″ needle. An additional 1.0 mL of the same material was administered IN to each pig (0.5 mL per nostril) using a sterile 3.0 mL Luer-lock syringe and nasal canula.
[0094] Test pigs were observed daily for overall health and adverse events on Day −4 and from Day 0 to Day 19. Observations were recorded on the Clinical Observation Record. All test pigs were observed from Day 0 to Day 7, and Group 7 was further observed from Day 14 to 21, for injection site reactions. Average daily weight gain was determined by weighing each pig on a calibrated scale on Days −3, 24 and 49, or on the day that a pig was found dead after challenge. Body weights were recorded on the Body Weight Form. Day −3 body weights were utilized to block pigs prior to randomization. Day 24 and Day 49 weight data was utilized to determine the average daily weight gain (ADWG) for each pig during these time points. For pigs that died after challenge and before Day 49, the ADWG was adjusted to represent the ADWG from Day 24 to the day of death.
[0095] In order to determine PCV2 serology, venous whole blood was collected from each piglet from the orbital venous sinus on Days −3 and 14. For each piglet, blood was collected from the orbital venous sinus by inserting a sterile capillary tube into the medial canthus of one of the eyes and draining approximately 3.0 mL of whole blood into a 4.0 mL Serum Separator Tube (SST). On Days 24, 31, and 49, venous whole blood from each pig was collected from the anterior vena cava using a sterile 18 g×1½″ Vacutainer needle (Becton Dickinson and Company, Franklin Lakes, N.J.), a Vacutainer needle holder and a 13 mL SST. Blood collections at each time point were recorded on the Sample Collection Record. Blood in each SST was allowed to clot, each SST was then spun down and the serum harvested. Harvested serum was transferred to a sterile snap tube and stored at −70±10° C. until tested at a later date. Serum samples were tested for the presence of PCV2 antibodies by BIVI-R&D personnel.
[0096] Pigs were observed once daily from Day 20 to Day 49 for clinical symptoms and clinical observations were recorded on the Clinical Observation Record.
[0097] To test for PCV2 nasal shedding, on Days 24, 25, and then every other odd numbered study day up to and including Day 49, a sterile dacron swab was inserted intra nasally into either the left or right nostril of each pig (one swab per pig) as aseptically as possible, swished around for a few seconds and then removed. Each swab was then placed into a single sterile snap-cap tube containing 1.0 mL of EMEM media with 2% II-BS, 500 units/mL of Penicillin, 500 μg/mL of Streptomycin and 2.5 μg/mL of Fungizone. The swab was broken off in the tube, and the snap tube was sealed and appropriately labeled with animal number, study number, date of collection, study day and “nasal swab.” Sealed snap tubes were stored at −40±10° C. until transported overnight on ice to BIVI-St. Joseph. Nasal swab collections were recorded on the Nasal Swab Sample Collection Form. BIVI-R&D conducted quantitative virus isolation (VI) testing for PCV2 on nasal swab samples. The results were expressed in log 10 values. A value of 1.3 logs or less was considered negative and any value greater than 1.3 logs was considered positive.
[0098] Pigs that died (Nos. 28, 52, 56, 69, 82, and 93) at the first study site were necropsied to the level necessary to determine a diagnosis. Gross lesions were recorded and no tissues were retained from these pigs. At the second study site, pigs that died prior to Day 49 (Nos. 45, 23, 58, 35), pigs found dead on Day 49 prior to euthanasia (Nos. 2, 43), and pigs euthanized on Day 49 were necropsied. Any gross lesions were noted and the percentages of lung lobes with lesions were recorded on the Necropsy Report Form.
[0099] From each of the 103 pigs necropsied at the second study site, a tissue sample of tonsil, lung, heart, liver, mesenteric lymph node, kidney and inguinal lymph node was placed into a single container with buffered 10% formalin; while another tissue sample from the same aforementioned organs was placed into a Whirl-pak (M-Tech Diagnostics Ltd., Thelwall, UK) and each Whirl-pak was placed on ice. Each container was properly labeled. Sample collections were recorded on the Necropsy Report Form. Afterwards, formalin-fixed tissue samples and a Diagnostic Request Form were submitted for IHC testing. IHC testing was conducted in accordance with standard ISU laboratory procedures for receiving samples, sample and slide preparation, and staining techniques. Fresh tissues in Whirl-paks were shipped with ice packs to the Study Monitor for storage (−70°±10° C.) and possible future use. Formalin-fixed tissues were examined by a pathologist for detection of PCV2 by IHC and scored using the following scoring system: 0=None; 1=Scant positive staining, few sites; 2=Moderate positive staining, multiple sites; and 3=Abundant positive staining, diffuse throughout the tissue. Due to the fact that the pathologist could not positively differentiate inguinal LN from mesenteric LN, results for these tissues were simply labeled as Lymph Node and the score given the highest score for each of the two tissues per animal.
Results
[0100] Results for this example are given below. It is noted that one pig from Group 9 died before Day 0, and 5 more pigs died post-vaccination (1 pig from Group 4; 1 pig from Group 6; 2 pigs from Group 8; and 1 pig from Group 9). Post-mortem examination indicated all six died due to underlying infections that were not associated with vaccination or PMWS. Additionally, no adverse events or injection site reactions were noted with any groups.
[0101] Average daily weight gain (ADWG) results are presented below in Table 6. Group 9, the strict negative control group, had the highest ADWG (1.06±0.17 lbs/day), followed by Group 5 (0.94±0.22 lbs/day), which received one dose of 8 μg of rORF2. Group 3, which received one dose of 4 μg of vORF2, had the lowest ADWG (0.49±0.21 lbs/day), followed by Group 7 (0.50±0.15 lbs/day), which received 2 doses of killed vaccine.
[0000]
TABLE 6
Summary of Group Average Daily Weight Gain (ADWG)
ADWG - lbs/day
(Day 24 to Day 49) or adjusted
Group
Treatment
N
for pigs dead before Day 29
1
vORF2 - 16 μg (1 dose)
12
0.87 ± 0.29 lbs/day
2
vORF2 - 8 μg (1 dose)
12
0.70 ± 0.32 lbs/day
3
vORF2 - 4 μg (1 dose)
12
0.49 ± 0.21 lbs/day
4
rORF2 - 16 μg (1 dose)
11
0.84 ± 0.30 lbs/day
5
rORF2 - 8 μg (1 dose)
12
0.94 ± 0.22 lbs/day
6
rORF2 - 4 μg (1 dose)
11
0.72 ± 0.25 lbs/day
7
KV (2 doses)
12
0.50 ± 0.15 lbs/day
8
Challenge Controls
10
0.76 ± 0.19 lbs/day
9
Strict Negative Controls
11
1.06 ± 0.17 lbs/day
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
[0102] PCV2 serology results are presented below in Table 7. All nine groups were seronegative for PCV2 on Day −3. On Day 14, Groups receiving vORF2 vaccines had the highest titers, which ranged from 187.5 to 529.2. Pigs receiving killed viral vaccine had the next highest titers, followed by the groups receiving rORF2 vaccines. Groups 8 and 9 remained seronegative at this time. On Day 24 and Day 31, pigs receiving vORF2 vaccines continued to demonstrate a strong serological response, followed closely by the group that received two doses of a killed viral vaccine. Pigs receiving rORF2 vaccines were slower to respond serologically and Groups 8 and 9 continued to remain seronegative. On Day 49, pigs receiving vORF2 vaccine, 2 doses of the killed viral vaccine and the lowest dose of rORF2 demonstrated the strongest serological responses. Pigs receiving 16 μg and 8 μg of rORF2 vaccines had slightly higher IFA titers than challenge controls. Group 9 on Day 49 demonstrated a strong serological response.
[0000]
TABLE 7
Summary of Group PCV2 IFA Titers
AVERAGE IFA TITER
Group
Treatment
Day-3
Day 14
Day 24
Day 31**
Day 49***
1
vORF2-16 μg
50.0
529.2
4400.0
7866.7
11054.5
(1 dose)
2
vORF2-8 μg
50.0
500.0
3466.7
6800.0
10181.8
(1 dose)
3
vORF2-4 μg
50.0
187.5
1133.3
5733.3
9333.3
(1 dose)
4
rORF2-16 μg
50.0
95.5
1550.0
3090.9
8000.0
(1 dose)
5
rORF2-8 μg
50.0
75.0
887.5
2266.7
7416.7
(1 dose)
6
rORF2-4 μg
50.0
50.0
550.0
3118.2
10570.0
(1 dose)
7
KV (2 doses)
50.0
204.2
3087.5
4620.8
8680.0
8
Challenge
50.0
55.0
50.0
50.0
5433.3
Controls
9
Strict Negative
50.0
59.1
59.1
54.5
6136.4
Controls
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
*For calculation purposes, a ≦100 IFA titer was designated as a titer of “50”; a ≧6400 IFA titer was designated as a titer of “12,800”.
**Day of Challenge
***Day of Necropsy
[0103] The results from the post-challenge clinical observations are presented below in Table 8. This summary of results includes observations for Abnormal Behavior, Abnormal Respiration, Cough and Diarrhea. Table 9 includes the results from the Summary of Group Overall Incidence of Clinical Symptoms and Table 10 includes results from the Summary of Group Mortality Rates Post-challenge. The most common clinical symptom noted in this study was abnormal behavior, which was scored as mild to severe lethargy. Pigs receiving the 2 lower doses of vORF2, pigs receiving 16 μg of rORF2 and pigs receiving 2 doses of KV vaccine had incidence rates of ≧27.3%. Pigs receiving 8 μg of rORF2 and the strict negative control group had no abnormal behavior. None of the pigs in this study demonstrated any abnormal respiration. Coughing was noted frequently in all groups (0 to 25%), as was diarrhea (0-20%). None of the clinical symptoms noted were pathognomic for PMWS.
[0104] The overall incidence of clinical symptoms varied between groups. Groups receiving any of the vORF2 vaccines, the group receiving 16 μg of rORF2, the group receiving 2 doses of KV vaccine, and the challenge control group had the highest incidence of overall clinical symptoms (≧36.4%). The strict negative control group, the group receiving 8 μg of rORF2 and the group receiving 4 μg of rORF2 had overall incidence rates of clinical symptoms of 0%, 8.3% and 9.1%, respectively.
[0105] Overall mortality rates between groups varied as well. The group receiving 2 doses of KV vaccine had the highest mortality rate (16.7%); while groups that received 4 μg of vORF2, 16 μg of rORF2, or 8 μg of rORF2 and the strict negative control group all had 0% mortality rates.
[0000]
TABLE 8
Summary of Group Observations for Abnormal Behavior, Abnormal
Respiration, Cough, and Diarrhea
Abnormal
Abnormal
Group
Treatment
N
Behavior 1
Behavior 2
Cough 3
Diarrhea 4
1
vORF2-16 μg
12
2/12
0/12
3/12
2/12
(1 dose)
(16.7%
(0%)
(25%)
(16/7%)
2
vORF2-8 μg
12
4/12
0/12
1/12
1/12
(1 dose)
(33.3%)
(0%)
(8.3%
(8.3%)
3
vORF2-4 μg
12
8/12
0/12
2/12
1/12
(1 dose)
(66.7%)
(0%)
(16.7%)
(8.3%)
4
rORF2-16 μg
11
3/11
0/11
0/11
2/11
(1 dose)
(27.3%)
(0%)
(0%)
(18.2%)
5
rORF2-8 μg
12
0/12
0/12
1/12
0/12
(1 dose)
(0%)
(0%)
(8.3%)
(0%)
6
rORF2-4 μg
11
1/11
0/11
0/11
0/12
(1 dose)
(9.1%)
(0%)
(0%)
(0%)
7
KV (2 doses)
12
7/12
0/12
0/12
1/12
(58.3)
(0%)
(0%)
(8.3%)
8
Challenge
10
1/10
0/10
2/10
2/10
Controls
(10%)
(0%)
(20%)
(20%)
9
Strict Negative
11
0/11
0/11
0/11
0/11
Controls
(0%)
(0%)
(0%)
(0%)
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
1 Total number of pigs in each group that demonstrated any abnormal behavior for at least one day
2 Total number of pigs in each group that demonstrated any abnormal respiration for at least one day
3 Total number of pigs in each group that demonstrated a cough for at least one day
4 Total number of pigs in each group that demonstrated diarrhea for at least one day
[0000]
TABLE 9
Summary of Group Overall Incidence of Clinical Symptoms
Incidence of pigs with
Incidence
Group
Treatment
N
Clinical Symptoms 1
Rate
1
vORF2 - 16 μg (1 dose)
12
5
41.7%
2
vORF2 - 8 μg (1 dose)
12
5
41.7%
3
vORF2 - 4 μg (1 dose)
12
8
66.7%
4
rORF2 - 16 μg (1 dose)
11
4
36.4%
5
rORF2 - 8 μg (1 dose)
12
1
8.3%
6
rORF2 - 4 μg (1 dose)
11
1
9.1%
7
KV (2 doses)
12
7
58.3%
8
Challenge Controls
10
4
40%
9
Strict Negative Controls
11
0
0%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
1 Total number of pigs in each group that demonstrated any clinical symptom for at least one day
[0000]
TABLE 10
Summary of Group Mortality Rates Post-challenge
Dead Post-
Group
Treatment
N
challenge
Mortality Rate
1
vORF2 - 16 μg (1 dose)
12
1
8.3%
2
vORF2 - 8 μg (1 dose)
12
1
8.3%
3
vORF2 - 4 μg (1 dose)
12
0
0%
4
rORF2 - 16 μg (1 dose)
11
0
0%
5
rORF2 - 8 μg (1 dose)
12
0
0%
6
rORF2 - 4 μg (1 dose)
11
1
9.1%
7
KV (2 doses)
12
2
16.7%
8
Challenge Controls
10
1
10%
9
Strict Negative Controls
11
0
0%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
[0106] PCV2 nasal shedding results are presented below in Table 11. Following challenge on Day 24, 1 pig in Group 7 began shedding PCV2 on Day 27. None of the other groups experienced shedding until Day 33. The bulk of nasal shedding was noted from Day 35 to Day 45. Groups receiving any of the three vORF2 vaccines and groups receiving either 4 or 8 μg of rORF2 had the lowest incidence of nasal shedding of PCV2 (≦9.1%). The challenge control group (Group 8) had the highest shedding rate (80%), followed by the strict negative control group (Group 9), which had an incidence rate of 63.6%.
[0000]
TABLE 11
Summary of Group Incidence of Nasal Shedding of PCV2
No. Of pigs that shed
Group
Treatment
N
for at least one day
Incidence Rate
1
vORF2 - 16 μg (1 dose)
12
1
8.3%
2
vORF2 - 8 μg (1 dose)
12
1
8.3%
3
vORF2 - 4 μg (1 dose)
12
1
8.3%
4
rORF2 - 16 μg (1 dose)
11
2
18.2%
5
rORF2 - 8 μg (1 dose)
12
1
8.3%
6
rORF2 - 4 μg (1 dose)
11
1
9.1%
7
KV (2 doses)
12
5
41.7%
8
Challenge Controls
10
8
80%
9
Strict Negative Controls
11
7
63.6%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
killed whole cell virus = PCV2 virus grown in suitable cell culture
[0107] The Summary of Group Incidence of Icterus, Group Incidence of Gastric Ulcers, Group Mean Lung Lesion Scores, and Group Incidence of Lung Lesions are shown below in Table 12. Six pigs died at the first test site during the post-vaccination phase of the study (Group 4, N=1; Group 6, N=1; Group 8, N=2; Group 9, N=2). Four out of six pigs had fibrinous lesions in one or more body cavities, one pig (Group 6) had lesions consistent with clostridial disease, and one pig (Group 9) had no gross lesions. None of the pigs that died during the post-vaccination phased of the study had lesions consistent with PMWS.
[0108] Pigs that died post-challenge and pigs euthanized on Day 49 were necropsied. At necropsy, icterus and gastric ulcers were not present in any group. With regard to mean % lung lesions, Group 9 had lowest mean % lung lesions (0%), followed by Group 1 with 0.40±0.50% and Group 5 with 0.68±1.15%. Groups 2, 3, 7 and 8 had the highest mean % lung lesions (≧7.27%). Each of these four groups contained one pig with % lung lesions ≧71.5%, which skewed the results higher for these four groups. With the exception of Group 9 with 0% lung lesions noted, the remaining 8 groups had ≦36% lung lesions. Almost all lung lesions noted were described as red/purple and consolidated.
[0000]
TABLE 12
Summary of Group Incidence of Icterus, Group Incidence of Gastric
Ulcers, Group Mean % Lung Lesion Scores, and Group Incidence of
Lung Lesions Noted
Mean %
Incidence of
Gastric
Lung
Lung Lesions
Group
Treatment
Icterus
Ulcers
Lesions
Noted
1
vORF2 - 16 μg
0/12 (0%)
0/12
0.40 ± 0.50%
10/12
(1 dose)
(0%)
(83%)
2
vORF2 - 8 μg
0/12 (0%)
0/12
7.41 ± 20.2%
10/12
(1 dose)
(0%)
(83%)
3
vORF2 - 4 μg
0/12 (0%)
0/12
9.20 ± 20.9%
10/12
(1 dose)
(0%)
(83%)
4
rORF2 - 16 μg
0/11 (0%)
0/11
1.5 ± 4.74%
4/11
(1 dose)
(0%)
(36%)
5
rORF2 - 8 μg
0/12 (0%)
0/12
0.68 ± 1.15%
9/12
(1 dose)
(0%)
(75%)
6
rORF2 - 4 μg
0/11 (0%)
0/11
2.95 ± 5.12%
7/11
(1 dose)
(0%)
(64%)
7
KV (2 doses)
0/12 (0%)
0/12
7.27 ± 22.9%
9/12
(0%)
(75%)
8
Challenge
0/10 (0%)
0/10
9.88 ± 29.2%
8/10
Controls
(0%)
(80%)
9
Strict Negative
0/11 (0%)
0/11
0/11
0/11
Controls
(0%)
(0%)
(0%)
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0109] The Summary of Group IHC Positive Incidence Results is shown in Table 13. Group 1 (vORF2-16 μg) and Group 5 (rORF2-8 μg) had the lowest rate of IHC positive results (16.7%). Group 8 (Challenge Controls) and Group 9 (Strict Negative Controls) had the highest rate of IHC positive results, 90% and 90.9%, respectively.
[0000]
TABLE 13
Summary of Group IHC Positive Incidence Rate
No. Of pigs that had at
least one tissue positive
Incidence
Group
Treatment
N
for PCV2
Rate
1
vORF2 - 16 μg (1 dose)
12
2
16.7%
2
vORF2 - 8 μg (1 dose)
12
3
25.0%
3
vORF2 - 4 μg (1 dose)
12
8
66.7%
4
rORF2 - 16 μg (1 dose)
11
4
36.3%
5
rORF2 - 8 μg (1 dose)
12
2
16.7%
6
rORF2 - 4 μg (1 dose)
11
4
36.4%
7
KV (2 doses)
12
5
41.7%
8
Challenge Controls
10
9
90.0%
9
Strict Negative Controls
11
10
90.9%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0110] Post-challenge, Group 5, which received one dose of 8 μg of rORF2 antigen, outperformed the other 6 vaccine groups. Group 5 had the highest ADWG (0.94±0.22 lbs/day), the lowest incidence of abnormal behavior (0%), the second lowest incidence of cough (8.3%), the lowest incidence of overall clinical symptoms (8.3%), the lowest mortality rate (0%), the lowest rate of nasal shedding of PCV2 (8.3%), the second lowest rate for mean % lung lesions (0.68±1.15%) and the lowest incidence rate for positive tissues (16.7%). Groups receiving various levels of rORF2 antigen overall outperformed groups receiving various levels of vORF2 and the group receiving 2 doses of killed whole cell PCV2 vaccine performed the worst. Tables 14 and 15 contain summaries of group post-challenge data.
[0000]
TABLE 14
Summary of Group Post-Challenge Data-Part 1
Overall
Incidence
ADWG
Abnormal
of Clinical
Group
N
Treatment
(lbs/day)
Behavior
Cough
Symptoms
1
12
vORF2-16 μg
0.87 ±
2/12
3/12
41.7%
(1 dose)
0.29
(16.7%)
(25%)
2
12
vORF2-8 μg
0.70 ±
4/12
1/12
41.7%
(1 dose)
0.32
(33.3%
(8.3%
3
12
vORF2-4 μg
0.49 ±
8/12
2/12
66.7%
(1 dose)
0.21
(66.7%)
(16.7%
4
11
rORF2-16 μg
0.84 ±
3/11
0/11
36.4%
(1 dose)
0.30
(27.3%)
(0%)
5
12
rORF2-8 μg
0.94 ±
0/12
1/12
8.3%
(1 dose)
0.22
(0%)
(8.3%
6
11
rORF2-4 μg
0.72 ±
1/11
0/11
9.1%
(1 dose)
0.25
(9.1%
(0%)
7
12
KV
0.50 ±
7/12
0/12
58.3%
(2 doses)
0.15
(58.3)
(0%)
8
10
Challenge
0.76 ±
1/10
2/10
40%
Controls
0.19
(10%)
(20%
9
11
Strict Negative
1.06 ±
0/11
0/11
0%
Controls
0.17
(0%)
(0%)
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0000]
TABLE 15
Summary of Group Post-Challenge Data-Part 2
Incidence
Rate of at
least one
Mean %
tissue IHC
Mortality
Nasal
Lung
positive
Group
N
Treatment
Rate
Shedding
Lesions
for PCV2
1
12
vORF2-16 μg
8.3%
8.3%
0.40 ±
16.7%
(1 dose)
0.50%
2
12
vORF2-8 μg
8.3%
8.3%
7.41 ±
25.0%
(1 dose)
20.2%
3
12
vORF2-4 μg
0%
8.3%
9.20 ±
66.7%
(1 dose)
20.9%
4
11
rORF2-16 μg
0%
18.2%
1.50 ±
36.3%
(1 dose)
4.74%
5
12
rORF2-8 μg
0%
8.3%
0.68 ±
16.7%
(1 dose)
1.15%
6
11
rORF2-4 μg
9.1%
9.1%
2.95 ±
36.4%
(1 dose)
5.12%
7
12
KV
16.7%
41.7%
7.27 ±
41.7%
(2 doses)
22.9%
8
10
Challenge
10%
80%
9.88 ±
90.0%
Controls
29.2%
9
11
Strict Negative
0%
63.6%
0/11
90.9%
Controls
(0%)
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0111] Results of this study indicate that all further vaccine efforts should focus on a rORF2 vaccine. Overall, nasal shedding of PCV2 was detected post-challenge and vaccination with a PCV2 vaccine resulted in a reduction of shedding. Immunohistochemistry of selected lymphoid tissues also served as a good parameter for vaccine efficacy, whereas large differences in ADWG, clinical symptoms, and gross lesions were not detected between groups. This study was complicated by the fact that extraneous PCV2 was introduced at some point during the study, as evidenced by nasal shedding of PCV2, PCV2 seroconversion and positive IHC tissues in Group 9, the strict negative control group.
Discussion
[0112] Seven PCV2 vaccines were evaluated in this study, which included three different dose levels of vORF2 antigen administered once on Day 0, three different dose levels of rORF2 antigen administered once on Day 0 and one dose level of killed whole cell PCV2 vaccine administered on Day 0 and Day 14. Overall, Group 5, which received 1 dose of vaccine containing 8 μg of rORF2 antigen, had the best results. Group 5 had the highest ADWG, the lowest incidence of abnormal behavior, the lowest incidence of abnormal respiration, the second lowest incidence of cough, the lowest incidence of overall clinical symptoms, the lowest mortality rate, the lowest rate of nasal shedding of PCV2, the second lowest rate for mean % lung lesions and the lowest incidence rate for positive IHC tissues.
[0113] Interestingly, Group 4, which received a higher dose of rORF2 antigen than Group 5, did not perform as well or better than Group 5. Group 4 had a slightly lower ADWG, a higher incidence of abnormal behavior, a higher incidence of overall clinical symptoms, a higher rate of nasal shedding of PCV2, a higher mean % lung lesions, and a higher rate for positive IHC tissues than Group 5. Statistical analysis, which may have indicated that the differences between these two groups were not statistically significant, was not conducted on these data, but there was an observed trend that Group 4 did not perform as well as Group 5.
[0114] Post-vaccination, 6 pigs died at the first study site. Four of the six pigs were from Group 8 or Group 9, which received no vaccine. None of the six pigs demonstrated lesions consistent with PMWS, no adverse events were reported and overall, all seven vaccines appeared to be safe when administered to pigs approximately 11 days of age. During the post-vaccination phase of the study, pigs receiving either of three dose levels of vORF2 vaccine or killed whole cell vaccine had the highest IFAT levels, while Group 5 had the lowest IFAT levels just prior to challenge, of the vaccine groups.
[0115] Although not formally proven, the predominant route of transmission of PCV2 to young swine shortly after weaning is believed to be by oronasal direct contact and an efficacious vaccine that reduces nasal shedding of PCV2 in a production setting would help control the spread of infection. Groups receiving one of three vORF2 antigen levels and the group receiving 8 μg of rORF2 had the lowest incidence rate of nasal shedding of PCV2 (8.3%). Expectedly, the challenge control group had the highest incidence rate of nasal shedding (80%).
[0116] Gross lesions in pigs with PMWS secondary to PCV2 infection typically consist of generalized lymphadenopathy in combination with one or a multiple of the following: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc. At necropsy, icterus, hepatitis, nephritis, and gastric ulcers were not noted in any groups and lymphadenopathy was not specifically examined for. The mean % lung lesion scores varied between groups. The group receiving 16 μg of vORF2 antigen had the lowest mean % lung lesion score (0.40±0.50%), followed by the group that received 8 μg of rORF2 (0.68±1.15%). As expected, the challenge control group had the highest mean % lung lesion score (9.88±29.2%). In all four groups, the mean % lung lesion scores were elevated due to one pig in each of these groups that had very high lung lesion scores. Most of the lung lesions were described as red/purple and consolidated. Typically, lung lesions associated with PMWS are described as tan and non-collapsible with interlobular edema. The lung lesions noted in this study were either not associated with PCV2 infection or a second pulmonary infectious agent may have been present. Within the context of this study, the % lung lesion scores probably do not reflect a true measure of the amount of lung infection due to PCV2.
[0117] Other researchers have demonstrated a direct correlation between the presence of PCV2 antigen by IHC and histopathology. Histopathology on select tissues was not conducted with this study. Group 1 (16 μg of vORF2) and Group 5 (8 μg of rORF2) had the lowest incidence rate of pigs positive for PCV2 antigen (8.3%), while Group 9 (the strict negative control group—90.9%) and Group 8 (the challenge control group—90.0%) had the highest incidence rates for pigs positive for PCV2 antigen. Due to the non-subjective nature of this test, IHC results are probably one of the best parameters to judge vaccine efficacy on.
[0118] Thus, in one aspect of the present invention, the Minimum Portective Dosage (MPD) of a 1 ml/1 dose recombinant product with extracted PCV2 ORF2 (rORF2) antigen in the CDCD pig model in the face of a PCV2 challenge was determined Of the three groups that received varying levels of rORF2 antigen, Group 5 (8 μg of rORF2 antigen) clearly had the highest level of protection. Group 5 either had the best results or was tied for the most favorable results with regard to all of the parameters examined. When Group 5 was compared with the other six vaccine groups post-challenge, Group 5 had the highest ADWG (0.94±0.22 lbs/day), the lowest incidence of abnormal behavior (0%), the second lowest incidence of cough (8.3%), the lowest incidence of overall clinical symptoms (8.3%), the lowest mortality rate (0%), the lowest rate of nasal shedding of PCV2 (8.3%), the second lowest rate for mean % lung lesions (0.68±1.15%) and the lowest incidence rate for positive IHC tissues (16.7%).
[0119] In another aspect of the present invention, the MPD of a 1 ml/1 dose conventional product that is partially purified PCV2 ORF2 (vORF2) antigen in the CDCD pig model in the face of a PCV2 challenge was determined Of the three groups that received varying levels of vORF2 antigen, Group 1 (16 μg of vORF2) had the highest level of protection. Group 1 outperformed Groups 2 and 3 with respect to ADWG, mean % lung lesions, and IHC. Groups 1 and 2 (8 μg of vORF2 antigen) performed equally with respect to overall incidence of clinical symptoms, Group 3 (4 μg of vORF2 antigen) had the lowest mortality rate, and all three groups performed equally with respect to nasal shedding. Overall, vORF vaccines did not perform as well as rORF vaccines.
[0120] In yet another aspect of the present invention, the efficacy of a maximum dose of a 2ml/2 dose Conventional Killed PCV2 vaccine in the CDCD pig model in the face of a PCV2 challenge was determined Of the seven vaccines evaluated in this study, the killed whole cell PCV2 vaccine performed the worst. Piglets receiving two doses of killed whole cell PCV2 vaccine had the lowest ADWG, the second highest rate of abnormal behavior (58.3%), the second highest overall incidence of clinical symptoms (58.3%), the highest mortality rate (16.7%), the second highest incidence of nasal shedding (41.7%), highest mean % lung lesions (9.88±29.2%), a high incidence of lung lesions noted (75%) and a moderate IHC incidence rate in tissues (41.7%). However, it was still effective at invoking an immune response.
[0121] In still another aspect of the present invention, nasal shedding of PCV2 was assessed as an efficacy parameter and the previous PCV2 efficacy parameters from previous studies were reconfirmed. Results from this study indicate that nasal shedding of PCV2 occurs following intra nasal challenge and that PCV2 vaccines reduce nasal shedding of PCV2 post-challenge. Furthermore, results from this study and reports in the literature indicate that IHC should continue to be evaluated in future PCV2 vaccine trials as well.
[0122] Some additional conclusions arising from this study are that lymphadenopathy is one of the hallmarks of PMWS. Another one of the hallmarks of PMWS is lymphoid depletion and multinucleated/giant histiocytes. Additionally, no adverse events or injection site reactions were noted for any of the 7 PCV2 vaccines and all 7 PCV2 vaccines appeared to be safe when administered to young pigs.
Example 5
[0123] This example tests the efficacy of eight PCV2 candidate vaccines and reconfirms PCV2 challenge parameters from earlier challenge studies following exposure to a virulent strain of PCV2. One hundred and fifty (150) cesarean derived colostrum deprived (CDCD) piglets, 6-16 days of age, were blocked by weight and randomly divided into 10 groups of equal size. Table 16 sets forth the General Study Design for this Example.
[0000]
TABLE 16
General Study Design
Challenge
KLH/ICFA
with
PRRSV
No.
on Day 22
Virulent
MLV
Necropsy
Of
Day of
and
PCV2 on
on
on
Group
Pigs
Treatment
Treatment
Day 28
Day 25
Day 46
Day 50
1
15
PVC2 Vaccine 1
0 & 14
+
+
+
+
16 μg
rORF2-IMS 1314
2
15
PVC2 Vaccine 2
0 & 14
+
+
+
+
16 μg
vORF2-Carbopol
3
15
PCV2 Vaccine 3
0 & 14
+
+
+
+
16 μg
rORF2-Carbopol
4
15
PCV2 Vaccine 2
0
+
+
+
+
16 μg
vORF2-Carbopol
5
15
PVC2 Vaccine 3
0 & 14
+
+
+
+
4 μg
rORF2-Carbopol
6
15
PVC2 Vaccine 3
0 & 14
+
+
+
+
1 μg
rORF2-Carbopol
7
15
PVC2 Vaccine 3
0 & 14
+
+
+
+
0.25 μg
rORF2-Carbopol
8
15
PVC2 Vaccine 4
0 & 14
+
+
+
+
>8.0 log
KV-Carbopol
9
15
Challenge
N/A
+
+
+
+
Controls
10
15
None-Strict
N/A
+
−
+
+
Negative Control
Group
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0124] The vaccine formulations given to each group were as follows. PCV2 Vaccine No. 1, administered at 1×2 ml dose to Group 1, was a high dose (16 μg/2 ml dose) of inactivated recombinant ORF2 antigen adjuvanted with IMS 1314 (16 μg rORF2—IMS 1314). PCV2 Vaccine No. 2, administered at 1×2 ml dose to Group 2, was a high dose (16 μg/2 ml dose) of a partially purified VIDO R−1 generated PCV2 ORF2 antigen adjuvanted with Carbopol (16 μg vORF2—Carbopol). PCV2 Vaccine No. 3, administered at 1×2 ml dose to Group 3, was a high dose (16 μg/2 ml dose) of inactivated recombinant ORF2 antigen adjuvanted with Carbopol (16 μg rORF2—Carbopol). PCV2 Vaccine No. 4, administered at 1×1 ml dose to Group 4, was a high dose (16 μg/1 ml dose) of a partially purified VIDO R−1 generated PCV2 ORF2 antigen adjuvanted with Carbopol (16 μg vORF2—Carbopol). Vaccine No. 5, administered at 1×2 ml dose to Group 5, was a 4 μg/2 ml dose of an inactivated recombinant ORF2 antigen adjuvanted with Carbopol (4 μg rORF2—Carbopol). PCV2 Vaccine No. 6, administered at 1×2 ml dose to Group 6, was a 1 μg/2 ml dose of an inactivated recombinant ORF2 antigen adjuvanted with Carbopol (1 μg rORF2—Carbopol). PCV2 Vaccine No. 7, administered at 1×2 ml dose to Group 7, was a low dose (0.25 μg/2 ml dose) of inactivated recombinant ORF2 antigen adjuvanted with Carbopol (0.25 μg rORF2—Carbopol). PCV2 Vaccine No. 8, administered at 1×2 ml dose to Group 8, was a high dose (pre-inactivation titer >8.0 log/2 ml dose) Inactivated Conventional Killed VIDO R−1 generated PCV2 Struve antigen adjuvanted with Carbopol (>8.0 log KV-Carbopol). On Day 0, Groups 1-8 were treated with their assigned vaccines. Groups 1-3 and 5-8 received boosters of their respective vaccines again on Day 14. The effectiveness of a single dose of 16 μg of vORF2—Carbopol was tested on Group 4 which did not receive a booster on Day 14. Piglets were observed for adverse events and injection site reactions following both vaccinations. On Day 21 the piglets were moved to a second study site where Groups 1-9 were group housed in one building and Group 10 was housed in a separate building. All pigs received keyhole limpet hemocyanin emulsified with incomplete Freund's adjuvant (KLH/ICFA) on Days 22 and 28. On Day 25, Groups 1-9 were challenged with approximately 4 logs of virulent PCV2 virus. By Day 46, very few deaths had occurred in the challenge control group. In an attempt to immunostimulate the pigs and increase the virulence of the PCV2 challenge material, all Groups were treated with INGELVAC® PRRSV MLV (Porcine Reproductive and Respiratory Vaccine, Modified Live Virus) on Day 46. Pre- and post-challenge blood samples were collected for PCV2 serology. Post-challenge, body weight data for determination of average daily weight gain (ADWG) and observations of clinical signs were collected. On Day 50, all surviving pigs were necropsied, gross lesions were recorded, lungs were scored for pathology, and selected tissues were preserved in formalin for examination by Immunohistochemistry (IHC) for detection of PCV2 antigen at a later date.
Materials and Methods
[0125] This was a partially-blind vaccination-challenge feasibility study conducted in CDCD pigs, 6 to 16 days of age on Day 0. To be included in the study, PCV2 IFA titers of sows were ≦1:1000. Additionally, the serologic status of sows were from a known PRRS-negative herd. Sixteen (16) sows were tested for PCV2 serological status and all sixteen (16) had a PCV2 titer of ≦1000 and were transferred to the first study site. One hundred fifty (150) piglets were delivered by cesarean section surgeries and were available for this study on Day −3. On Day −3, 150 CDCD pigs at the first study site were weighed, identified with ear tags, blocked by weight and randomly assigned to 1 of 10 groups, as set forth above in table 16. Blood samples were collected from all pigs. If any test animal meeting the inclusion criteria was enrolled in the study and was later excluded for any reason, the Investigator and Monitor consulted in order to determine the use of data collected from the animal in the final analysis. The date of which enrolled piglets were excluded and the reason for exclusion was documented. No sows meeting the inclusion criteria, selected for the study and transported to the first study site were excluded. No piglets were excluded from the study, and no test animals were removed from the study prior to termination. Table 17 describes the time frames for the key activities of this Example.
[0000]
TABLE 17
Study Activities
Study
Day
Actual Dates
Study Activity
−3
Apr. 4, 2003
Weighed pigs; health exam; randomized to
groups; collected blood samples
−3, 0-21
Apr. 4, 2003
Observed for overall health and for adverse
Apr. 7, 2003 to
events post-vaccination
May 27, 2003
0
Apr. 7, 2003
Administered respective IVPs to Groups 1-8
0-7
Apr. 7, 2003 to
Observed pigs for injection site reactions
Apr. 14, 2003
14
Apr. 21, 2003
Boostered Groups 1-3, 5-8 with respective
IVPs; blood sampled all pigs
14-21
Apr. 21, 2003 to
Observed pigs for injection reactions
Apr. 28, 2003
19-21
Apr. 26, 2003 to
Treated all pigs with antibiotics
Apr. 28, 2003
21
Apr. 28, 2003
Pigs transported from Struve Labs, Inc. to
Veterinary Resources, Inc.(VRI)
22-50
Apr. 28, 2003 to
Observed pigs for clinical signs post-
May 27, 2003
challenge
22
Apr. 29, 2003
Treated Groups 1-10 with KLH/ICFA
25
May 2, 2003
Collected blood samples from all pigs;
weighed all pigs; challenged Groups 1-9
with PCV2 challenge material
28
May 5, 2003
Treated Groups 1-10 with KLH/ICFA
32
May 9, 2003
Collected blood samples from all pigs
46
May 23, 2003
Administered INGELVAC ® PRRS MLV
to all groups
50
May 27, 2003
Collected blood samples, weighed and
necropsied all pigs; gross lesions were
recorded; lungs were evaluated for lesions;
fresh and formalin fixed tissue samples were
saved; In-life phase of the study was
completed
[0126] Following completion of the in-life phase of the study, formalin fixed tissues were examined by Immunohistochemistry (IHC) for detection of PCV2 antigen by a pathologist, blood samples were evaluated for PCV2 serology, and average daily weight gain (ADWG) was determined from Day 25 to Day 50.
[0127] Animals were housed at the first study site in individual cages in seven rooms from birth to approximately 11 days of age (approximately Day 0 of the study). Each room was identical in layout and consisted of stacked individual stainless steel cages with heated and filtered air supplied separately to each isolation unit. Each room had separate heat and ventilation, thereby preventing cross-contamination of air between rooms. Animals were housed in two different buildings at the second study site. Group 10 (The Strict negative control group) was housed separately in a converted nursery building and Groups 1-9 were housed in a converted farrowing building. Each group was housed in a separate pen (14-15 pigs per pen) and each pen provided approximately 2.3 square feet per pig. Groups 2, 4 and 8 were penned in three adjacent pens on one side of the alleyway and Groups 1, 3, 5, 6, 7, and 9 were penned in six adjacent pens on the other side of the alleyway. The Group separation was due to concern by the Study Monitor that vaccines administered to Groups 2, 4, and 8 had not been fully inactivated. Each pen was on an elevated deck with plastic slatted floors. A pit below the pens served as a holding tank for excrement and waste. Each building had its own separate heating and ventilation systems, with little likelihood of cross-contamination of air between buildings.
[0128] At the first study site, piglets were fed a specially formulated milk ration from birth to approximately 3 weeks of age. All piglets were consuming solid, special mixed ration by Day 21 (approximately 4½ weeks of age). At the second study site, all piglets were fed a custom non-medicated commercial mix ration appropriate for their age and weight, ad libitum. Water at both study sites was also available ad libitum.
[0129] All test pigs were treated with 1.0 mL of NAXCEL®, IM, in alternating hams on Days 19, 20, and 21. In addition, Pig No. 11 (Group 1) was treated with 0.5 mL of NAXCEL® IM on Day 10, Pig No. 13 (Group 10) was treated with 1 mL of Penicillin and 1 mL of PREDEF® 2× on Day 10, Pig No. 4 (Group 9) was treated with 1.0 mL of NAXCEL® IM on Day 11, and Pigs 1 (Group 1), 4 and 11 were each treated with 1.0 mL of NAXCEL® on Day 14 for various health reasons.
[0130] While at both study sites, pigs were under veterinary care Animal health examinations were conducted on Day −3 and were recorded on the Health Examination Record Form. All animals were in good health and nutritional status before vaccination as determined by observation on Day 0. All test animals were observed to be in good health and nutritional status prior to challenge. Carcasses and tissues were disposed of by rendering. Final disposition of study animals was recorded on the Animal Disposition Record.
[0131] On Days 0 and 14, pigs assigned to Groups 1-3 and 5-8 received 2.0 mL of assigned PCV2 Vaccines 1-4, respectively, IM in the right and left neck region, respectively, using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×½″ needle. Pigs assigned to Group 4 received 1.0 mL of PCV2 Vaccine No. 2, IM in the right neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×½″ needle on Day 0 only.
[0132] On Day 22 all test pigs received 2.0 mL of KLH/ICFA IM in the left neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×1″ needle. On Day 28 all test pigs received 2.0 mL of KLH/ICFA in the right ham region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×1″ needle.
[0133] On Day 25, pigs assigned to Groups 1-9 received 1.0 mL of PCV2 ISUVDL challenge material (3.98 log 10 TCID 50 /mL) IM in the right neck region using a sterile 3.0 mL Luer-lock syringe and a sterile 20 g×1″ needle. An additional 1.0 mL of the same material was administered IN to each pig (0.5 mL per nostril) using a sterile 3.0 mL Luer-lock syringe and nasal canula.
[0134] On Day 46, all test pigs received 2.0 mL INGELVAC® PRRS MLV, IM, in the right neck region using a sterile 3.0 mL Luer0lock syringe and a sterile 20 g×1″ needle. The PRRSV MLV was administered in an attempt to increase virulence of the PCV2 challenge material.
[0135] Test pigs were observed daily for overall health and adverse events on Day −3 and from Day 0 to Day 21. Each of the pigs were scored for normal or abnormal behavior, respiration, or cough. Observations were recorded on the Clinical Observation Record. All test pigs were observed from Day 0 to Day 7, and Group 7 was further observed from Day 14 to 21, for injection site reactions. Average daily weight gain was determined by weighing each pig on a calibrated scale on Days −3, 25 and 50, or on the day that a pig was found dead after challenge. Body weights were recorded on the Body Weight Form. Day −3 body weights were utilized to block pigs prior to randomization. Day 25 and Day 50 weight data was utilized to determine the average daily weight gain (ADWG) for each pig during these time points. For pigs that died after challenge and before Day 50, the ADWG was adjusted to represent the ADWG from Day 25 to the day of death.
[0136] In order to determine PCV2 serology, venous whole blood was collected from each piglet from the orbital venous sinus on Days −3 and 14. For each piglet, blood was collected from the orbital venous sinus by inserting a sterile capillary tube into the medial canthus of one of the eyes and draining approximately 3.0 mL of whole blood into a 4.0 mL Serum Separator Tube (SST). On Days 25, 32, and 50, venous whole blood from each pig was collected from the anterior vena cava using a sterile 20 g×1½″ Vacutainer® needle (Becton Dickinson and Company, Franklin Lakes, N.J.), a Vaccutainer® needle holder and a 13 mL SST. Blood collections at each time point were recorded on the Sample Collection Record. Blood in each SST was allowed to clot, each SST was then spun down and the serum harvested. Harvested serum was transferred to a sterile snap tube and stored at −70±10° C. until tested at a later date. Serum samples were tested for the presence of PCV2 antibodies by BIVI-R&D personnel.
[0137] Pigs were observed once daily from Day 22 to Day 50 for clinical symptoms and scored for normal or abnormal behavior, respiration or cough. Clinical observations were recorded on the Clinical Observation Record.
[0138] Pigs Nos. 46 (Group 1) and 98 (Groups 9) died at the first study site. Both of these deaths were categorized as bleeding deaths and necropsies were not conducted on these two pigs. At the second study site, pigs that died after challenge and prior to Day 50, and pigs euthanized on Day 50, were necropsied. Any gross lesions were noted and the percentages of lung lobes with lesions were recorded on the Necropsy Report Form.
[0139] From each of the pigs necropsied at the second study site, a tissue sample of tonsil, lung, heart, and mesenteric lymph node was placed into a single container with buffered 10% formalin; while another tissue sample from the same aforementioned organs was placed into a Whirl-Pak® (M-Tech Diagnostics Ltd., Thelwall, UK) and each Whirl-Pak® was placed on ice. Each container was properly labeled. Sample collections were recorded on the Necropsy Report Form. Afterwards, formalin-fixed tissue samples and a Diagnostic Request Form were submitted for IHC testing. IHC testing was conducted in accordance with standard laboratory procedures for receiving samples, sample and slide preparation, and staining techniques. Fresh tissues in Whirl-Paks® were shipped with ice packs to the Study Monitor for storage (−70°±10° C.) and possible future use.
[0140] Formalin-fixed tissues were examined by a pathologist for detection of PCV2 by IHC and scored using the following scoring system: 0=None; 1=Scant positive staining, few sites; 2=Moderate positive staining, multiple sites; and 3=Abundant positive staining, diffuse throughout the tissue. For analytical purposes, a score of 0 was considered “negative,” and a score of greater than 0 was considered “positive.”
Results
[0141] Results for this example are given below. It is noted that Pigs No. 46 and 98 died on days 14 and 25 respectively. These deaths were categorized as bleeding deaths. Pig No. 11 (Group 1) was panting with rapid respiration on Day 15. Otherwise, all pigs were normal for behavior, respiration and cough during this observation period and no systemic adverse events were noted with any groups. No injection site reactions were noted following vaccination on Day 0. Following vaccination on Day 14, seven (7) out of fourteen (14) Group 1 pigs (50.0%) had swelling with a score of “2” on Day 15. Four (4) out of fourteen (14) Group 1 (28.6%) still had a swelling of “2” on Day 16. None of the other groups experienced injection site reactions following either vaccination.
[0142] Average daily weight gain (ADWG) results are presented below in Table 18. Pig Nos. 46 and 98 that died from bleeding were excluded from group results. Group 4, which received one dose of 16 μg vORF2—Carbopol, had the highest ADWG (1.16±0.26 lbs/day), followed by Groups 1, 2, 3, 5, 6, and 10 which had ADWGs that ranged from 1.07±0.23 lbs/day to 1.11±0.26 lbs/day. Group 9 had the lowest ADWG (0.88±0.29 lbs/day), followed by Groups 8 and 7, which had ADWGs of 0.93±0.33 lbs/day and 0.99±0.44 lbs/day, respectively.
[0000]
TABLE 18
Summary of Group Average Daily Weight Gains (ADWG)
ADWG - lbs/day
(Day 25 to Day 50)
or adjusted for pigs
Group
Treatment
N
dead before Day 50
1
rORF2 - 16 μg - IMS 1314 2 doses
14
1.08 ± 0.30 lbs/day
2
vORF2 - 16 μg - Carbopol 2 doses
15
1.11 ± 0.16 lbs/day
3
rORF2 - 16 μg - Carbopol 2 doses
15
1.07 ± 0.21 lbs/day
4
vORF2 - 16 μg - Carbopol 1 dose
15
1.16 ± 0.26 lbs/day
5
rORF2 - 4 μg - Carbopol 1 dose
15
1.07 ± 0.26 lbs/day
6
rORF2 - 1 μg - Carbopol 2 doses
15
1.11 ± 0.26 lbs/day
7
rORF2 - 0.25 μg - Carbopol 2 doses
15
0.99 ± 0.44 lbs/day
8
KV > 8.0 μg - Carbopol 2 doses
15
0.93 ± 0.33 lbs/day
9
Challenge Controls
14
0.88 ± 0.29 lbs/day
10
Strict Negative Controls
15
1.07 ± 0.23 lbs/day
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0143] PVC2 serology results are presented below in Table 19. All ten (10) groups were seronegative for PCV2 on Day −3. On Day 14, PCV2 titers remained low for all ten (10) groups (range of 50-113). On Day 25, Group 8, which received the whole cell killed virus vaccine, had the highest PCV2 titer (4617), followed by Group 2, which received 16 μg vORF2—Carbopol, Group 4, which received as single dose of 16 μg vORF2—Carbopol, and Group 3, which received 16 μg rORF2—Carbopol, which had titers of 2507, 1920 and 1503 respectively. On Day 32 (one week post challenge), titers for Groups 1-6 and Group 8 ranged from 2360 to 7619; while Groups 7 (0.25 μg rORF2—Carbopol), 9 (Challenge Control), and 10 (Strict negative control) had titers of 382, 129 and 78 respectively. On Day 50 (day of necropsy), all ten (10) groups demonstrated high PCV2 titers (≧1257).
[0144] On Days 25, 32, and 50, Group 3, which received two doses of 16 μg rORF2—Carbopol, had higher antibody titers than Group 1, which received two doses of 16 μg rORF2—IMS 1314. On Days 25, 32 and 50, Group 2, which received two doses of 16 μg vORF2, had higher titers than Group 4, which received only one does of the same vaccine. Groups 3, 5, 6, 7, which received decreasing levels of rORF2—Carbopol, of 16, 4, 1, and 0.25 μg respectively, demonstrated correspondingly decreasing antibody titers on Days 25 and 32.
[0000]
TABLE 19
Summary of Group PCV2 IFA Titers
Group
Treatment
Day-3
Day 14**
Day 25***
Day 32
Day 50****
1
rORF2-16 μg-IMS 1314
50
64
646
3326
4314
2 doses
2
vORF2-16 μg-Carbopol
50
110
2507
5627
4005
2 doses
3
rORF2-16 μg-Carbopol
50
80
1503
5120
6720
2 doses
4
vORF2-16 μg-Carbopol
50
113
1920
3720
1257
1 dose
5
rORF2-4 μg-Carbopol
50
61
1867
3933
4533
1 dose
6
rORF2-Carbopol
50
70
490
2360
5740
2 doses
7
rORF2-0.25 μg-Carbopol
50
73
63
382
5819
2 doses
8
KV > 8.0 log-Carbopol
50
97
4617
7619
10817
2 doses
9
Challenge Controls
50
53
50
129
4288
10
Strict Negative Controls
50
50
50
78
11205
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
*For calculation purposes, a ≦100 IFA titer was designated as a titer of “50”; a ≧6400 IFA titer was designated as a titer of “12,800”.
**Day of Challenge
***Day of Necropsy
[0145] The results from the post-challenge clinical observations are presented below. Table 20 includes observations for Abnormal Behavior, Abnormal Respiration, Cough and Diarrhea. Table 21 includes the results from the Summary of Group Overall Incidence of Clinical Symptoms and Table 22 includes results from the Summary of Group Mortality Rates Post-challenge. The incidence of abnormal behavior, respiration and cough post-challenge were low in pigs receiving 16 μg rORF2—IMS 1314 (Group 1), 16 μg rORF2—Carbopol (Group 3), 1 μg rORF2—Carbopol (Group 6), 0.25 μg rORF2—Carbopol (Group 7), and in pigs in the Challenge Control Group (Group 9). The incidence of abnormal behavior, respiration, and cough post-challenge was zero in pigs receiving 16 μg vORF2—Carbopol (Group 2), a single dose of 16 μg vORF2—Carbopol (Group 4), 4 μg rORF2—Carbopol (Group 5), >8 log KV-Carbopol (Group 8), and in pigs in the strict negative control group (Group 10).
[0146] The overall incidence of clinical symptoms varied between groups. Pigs receiving 16 μg vORF2—Carbopol (Group 2), a single dose of 16 μg vORF2—Carbopol (Group 4), and pigs in the Strict negative control group (Group 10) had incidence rates of 0%; pigs receiving 16 μg rORF2—Carbopol (Group 3), and 1 μg rORF2—Carbopol (Group 6) had incidence rates of 6.7%; pigs receiving 16 μg rORF2—IMS 1314 (Group 1) had an overall incidence rate of 7.1%; pigs receiving 4 μg rORF2—Carbopol (Group 5), 0.25 μg rORF2—Carbopol (Group 7), and >8 log KV vaccine had incidence rates of 13.3%; and pigs in the Challenge Control Group (Group 9) had an incidence rate of 14.3%.
[0147] Overall mortality rates between groups varied as well. Group 8, which received 2 doses of KV vaccine had the highest mortality rate of 20.0%; followed by Group 9, the challenge control group, and Group 7, which received 0.25 μg rORF2—Carbopol and had mortality rates of 14.3% and 13.3% respectively. Group 4, which received one dose of 16 μg vORF2—Carbopol had a 6.7% mortality rate. All of the other Groups, 1, 2, 3, 5, 6, and 10, had a 0% mortality rate.
[0000]
TABLE 20
Summary of Group Observations for Abnormal Behavior, Abnormal
Respiration, and Cough Post-Challenge
Abnormal
Abnormal
Group
Treatment
N
Behavior 1
Behavior 2
Cough 3
1
rORF2 - 16 μg - IMS 1314
14
0/14
0/14
1/14
2 doses
(0%)
(0%)
(7.1%)
2
vORF2 - 16 μg - Carbopol
15
0/15
0/15
0/15
2 doses
(0%)
(0%)
(0%)
3
rORF2 - 16 μg - Carbopol
15
0/15
0/15
1/15
2 doses
(0%)
(0%)
(6.7%)
4
vORF2 - 16 μg - Carbopol
15
0/15
0/15
0/15
1 dose
(0%)
(0%)
(0%)
5
rORF2 - 4 μg - Carbopol
15
1/15
1/15
0/15
1 dose
(6.7%)
(6.7%)
(0%)
6
rORF2 - 1 μg - Carbopol
15
0/15
0/15
1/15
2 doses
(0%)
(0%)
(6.7%)
7
rORF2 - 0.25 μg - Carbopol
15
0/15
0/15
1/15
2 doses
(0%)
(6.7%)
(06.7%)
8
KV > 8.0 log - Carbopol
15
1/15
1/15
0/15
2 doses
(6.7%)
(6.7%)
(0%)
9
Challenge Controls
14
1/14
1/14
2/14
(7.1%)
(7.1%)
(14.3%)
10
Strict Negative Controls
15
0/15
0/15
0/15
(0%)
(0%)
(0%)
1 Total number of pigs in each group that demonstrated any abnormal behavior for at least one day
2 Total number of pigs in each group that demonstrated any abnormal respiration for at least one day
3 Total number of pigs in each group that demonstrated a cough for at least one day
[0000]
TABLE 21
Summary of Group Overall Incidence of Clinical Symptoms Post-
Challenge
Incidence of pigs
with Clinical
Incidence
Group
Treatment
N
Symptoms 1
Rate
1
rORF2 - 16 μg - IMS 1314
14
1
7.1%
2 doses
2
vORF2 - 16 μg - Carbopol
15
0
0.0%
2 doses
3
rORF2 - 16 μg - Carbopol
15
1
6.7%
2 doses
4
vORF2 - 16 μg - Carbopol
15
0
0.0%
1 dose
5
rORF2 - 4 μg - Carbopol
15
2
13.3%
1 dose
6
rORF2 - 1 μg - Carbopol
15
1
6.7%
2 doses
7
rORF2 - 0.25 μg - Carbopol
15
2
13.3%
2 doses
8
KV > 8.0 log - Carbopol
15
2
13.3%
2 doses
9
Challenge Controls
14
2
14.3%
10
Strict Negative Controls
15
0
0.0%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
1 Total number of pigs in each group that demonstrated any clinical symptom for at least one day
[0000]
TABLE 22
Summary of Group Mortality Rates Post-Challenge
Dead Post-
Group
Treatment
N
challenge
Mortality Rate
1
rORF2 - 16 μg - IMS 1314
14
0
0.0%
2 doses
2
vORF2 - 16 μg - Carbopol
15
0
0.0%
2 doses
3
rORF2 - 16 μg - Carbopol
15
0
0.0%
2 doses
4
vORF2 - 16 μg - Carbopol
15
1
6.7%
1 dose
5
rORF2 - 4 μg - Carbopol
15
0
0.0%
1 dose
6
rORF2 - 1 μg - Carbopol
15
0
0.0%
2 doses
7
rORF2 - 0.25 μg - Carbopol
15
2
13.3%
2 doses
8
KV > 8.0 log - Carbopol
15
3
20.0%
2 doses
9
Challenge Controls
14
2
14.3%
10
Strict Negative Controls
15
0
0.0%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0148] The Summary of Group Mean Percentage Lung Lesions and Tentative Diagnosis is given below in Table 23. Group 9, the challenge control group, had the highest percentage lung lesions with a mean of 10.81±23.27%, followed by Group 7, which received 0.25 μg rORF2—Carbopol and had a mean of 6.57±24.74%, Group 5, which received 4 μg rORF2—Carbopol and had a mean of 2.88±8.88%, and Group 8, which received the KV vaccine and had a mean of 2.01±4.98%. The remaining six (6) groups had lower mean percentage lung lesions that ranged from 0.11±0.38% to 0.90±0.15%.
[0149] Tentative diagnosis of pneumonia varied among the groups. Group 3, which received two doses of 16 μg rORF2—Carbopol, had the lowest tentative diagnosis of pneumonia, with 13.3%. Group 9, the challenge control group, had 50% of the group tentatively diagnosed with pneumonia, followed by Group 10, the strict negative control group and Group 2, which received two doses of 16 μg vORF2—Carbopol, with 46.7% and 40% respectively, tentatively diagnosed with pneumonia.
[0150] Groups 1, 2, 3, 5, 9, and 10 had 0% of the group tentatively diagnosed as PCV2 infected; while Group 8, which received two doses if KV vaccine, had the highest group rate of tentative diagnosis of PCV2 infection, with 20%. Group 7, which received two doses of 0.25 μg rORF2—Carbopol, and Group 4, which received one dose of 16 μg vORF2—Carbopol had tentative group diagnoses of PCV2 infection in 13.3% and 6.7% of each group, respectively.
[0151] Gastric ulcers were only diagnosed in one pig in Group 7 (6.7%); while the other 9 groups remained free of gastric ulcers.
[0000]
TABLE 23
Summary of Group Mean % Lung Lesion and Tentative Diagnosis
No. Of pigs that shed
Incidence
Group
Treatment
N
for at least one day
Rate
1
rORF2 - 16 μg - IMS 1314
15
0
0%
2 doses
2
vORF2 - 16 μg - Carbopol
15
1
6.7%
2 doses
3
rORF2 - 16 μg - Carbopol
15
3
20.0%
2 doses
4
vORF2 - 16 μg - Carbopol
15
2
13.3%
1 dose
5
rORF2 - 4 μg - Carbopol
15
3
20.0%
1 dose
6
rORF2 - 1 μg - Carbopol
15
6
40.0%
2 doses
7
rORF2 - 0.25 μg - Carbopol
15
7
46.7%
2 doses
8
KV > 8.0 log - Carbopol
15
12
80%
2 doses
9
Challenge Controls
14
14
100.0%
10
Strict Negative Controls
15
14
93.3%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
[0152] The Summary of Group IHC Positive Incidence Results is shown below in Table 24. Group 1 (16 μg rORF2—IMS 1314) had the lowest group rate of IHC positive results with 0% of the pigs positive for PCV2, followed by Group 2 (16 μg vORF2—Carbopol) and Group 4 (single dose 16 μg vORF2—Carbopol), which had group IHC rates of 6.7% and 13.3% respectively. Group 9, the challenge control group, had the highest IHC positive incidence rate with 100% of the pigs positive for PCV2, followed by Group 10, the strict negative control group, and Group 8 (KV vaccine), with 93.3% and 80% of the pigs positive for PCV2, respectively.
[0000]
TABLE 24
Summary of Group IHC Positive Incidence Rate
No. Of pigs that shed
Incidence
Group
Treatment
N
for at least one day
Rate
1
rORF2 - 16 μg - IMS 1314
15
0
0%
2 doses
2
vORF2 - 16 μg - Carbopol
15
1
6.7%
2 doses
3
rORF2 - 16 μg - Carbopol
15
3
20.0%
2 doses
4
vORF2 - 16 μg - Carbopol
15
2
13.3%
1 dose
5
rORF2 - 4 μg - Carbopol
15
3
20.0%
1 dose
6
rORF2 - 1 μg - Carbopol
15
6
40.0%
2 doses
7
rORF2 - 0.25 μg - Carbopol
15
7
46.7%
2 doses
8
KV > 8.0 log - Carbopol
15
12
80%
2 doses
9
Challenge Controls
14
14
100.0%
10
Strict Negative Controls
15
14
93.3%
vORF2 = isolated viral ORF2;
rORF2 = recombinant baculovirus expressed ORF2;
KV or killed whole cell virus = PCV2 virus grown in suitable cell culture
Discussion
[0153] Seven PCV2 vaccines were evaluated in this example, which included a high dose (16 μg) of rORF2 antigen adjuvanted with IMS 1314 administered twice, a high dose (16 μg) of vORF2 antigen adjuvanted with Carbopol administered once to one group of pigs and twice to a second group of pigs, a high dose (16 μg) of rORF2 antigen adjuvanted with Carbopol administered twice, a 4 μg dose of rORF2 antigen adjuvanted with Carbopol administered twice, a 1 μg dose of rORF2 antigen adjuvanted with Carbopol administered twice, a low dose (0.25 μg) of rORF2 antigen adjuvanted with Carbopol administered twice, and a high dose (>8 log) of killed whole cell PCV2 vaccine adjuvanted with Carbopol. Overall, Group 1, which received two doses of 16 μg rORF2—IMS 1314, performed slightly better than Groups 2 through 7, which received vaccines containing various levels of either vORF2 or rORF2 antigen adjuvanted with Carbopol and much better than Group 8, which received two doses of killed whole cell PCV2 vaccine. Group 1 had the third highest ADWG (1.80±0.30 lbs/day), the lowest incidence of abnormal behavior (0%), the lowest incidence of abnormal respiration (0%), a low incidence of cough (7.1%), a low incidence of overall clinical symptoms (7.1%), was tied with three other groups for the lowest mortality rate (0%), the second lowest rate for mean % lung lesions (0.15±0.34%), the second lowest rate for pneumonia (21.4%) and the lowest incidence rate for positive IHC tissues (0%). Group 1 was, however, the only group in which injection site reactions were noted, which included 50% of the vaccinates 1 day after the second vaccination. The other vaccines administered to Groups 2 through 7 performed better than the killed vaccine and nearly as well as the vaccine administered to Group 1.
[0154] Group 8, which received two doses of killed PCV2 vaccine adjuvanted with Carbopol, had the worst set of results for any vaccine group. Group 8 had the lowest ADWG (0.93±0.33 lbs/day), the second highest rate of abnormal behavior (6.7%), the highest rate of abnormal respiration (6.7%), was tied with three other groups for the highest overall incidence rate of clinical symptoms (13.3%), had the highest mortality rate of all groups (20%), and had the highest positive IHC rate (80%) of any vaccine group. There was concern that the killed whole cell PCV2 vaccine may not have been fully inactivated prior to administration to Group 8, which may explain this group's poor results. Unfortunately, definitive data was not available to confirm this concern. Overall, in the context of this example, a Conventional Killed PCV2 vaccine did not aid in the reduction of PCV2 associated disease.
[0155] As previously mentioned, no adverse events were associated with the test vaccines with exception of the vaccine adjuvanted with IMS 1314. Injection site reactions were noted in 50.0% of the pigs 1 day after the second vaccination with the vaccine formulated with IMS 1314 and in 28.6% of the pigs 2 days after the second vaccination. No reactions were noted in any pigs receiving Carbopol adjuvanted vaccines. Any further studies that include pigs vaccinated with IMS 1314 adjuvanted vaccines should continue to closely monitor pigs for injection site reactions.
[0156] All pigs were sero-negative for PCV2 on Day −3 and only Group 2 had a titer above 100 on Day 14. On Day 25 (day of challenge), Group 8 had the highest PCV2 antibody titer (4619), followed by Group 2 (2507). With the exception of Groups 7, 9 and 10, all groups demonstrated a strong antibody response by Day 32. By Day 50, all groups including Groups 7, 9 and 10 demonstrated a strong antibody response.
[0157] One of the hallmarks of late stage PCV2 infection and subsequent PMWS development is growth retardation in weaned pigs, and in severe cases, weight loss is noted. Average daily weight gain of groups is a quantitative method of demonstrating growth retardation or weight loss. In this example, there was not a large difference in ADWG between groups. Group 8 had the lowest ADWG of 0.88±0.29 lbs/day, while Group 4 had the highest ADWG of 1.16±0.26 lb/day. Within the context of this study there was not a sufficient difference between groups to base future vaccine efficacy on ADWG.
[0158] In addition to weight loss—dyspnea, leghargy, pallor of the skin and sometimes icterus are clinical symptoms associated with PMWS. In this example, abnormal behavior and abnormal respiration and cough were noted infrequently for each group. As evidenced in this study, this challenge model and challenge strain do not result in overwhelming clinical symptoms and this is not a strong parameter on which to base vaccine efficacy.
[0159] Overall, mortality rates were not high in this example and the lack of a high mortality rate in the challenge control group limits this parameter on which to base vaccine efficacy. Prior to Day 46, Groups 4 and 7 each had one out of fifteen pigs die, Group 9 had two out of fourteen pigs die and Group 8 had three out of fifteen pigs die. Due to the fact that Group 9, the challenge control group was not demonstrating PCV2 clinical symptoms and only two deaths had occurred in this group by Day 46, Porcine Respiratory and Reproductive Syndrome Virus (PRRSV) MLV vaccine was administered to all pigs on Day 46. Earlier studies had utilized INGELVAC® PRRS MLV as an immunostimulant to exasperate PCV2-associated PMWS disease and mortality rates were higher in these earlier studies. Two deaths occurred shortly after administering the PRRS vaccine on Day 46—Group 4 had one death on Day 46 and Group 7 had one death on Day 47—which were probably not associated with the administration of the PRRS vaccine. By Day 50, Group 8, which received two doses of killed vaccine, had the highest mortality rate (20%), followed by Group 9 (challenge control) and Group 7 (0.25 μg rORF2—Carbopol), with mortality rates of 14.3% and 13.3% respectively. Overall, administration of the PRRS vaccine to the challenge model late in the post-challenge observation phase of this example did not significantly increase mortality rates.
[0160] Gross lesions in pigs with PMWS secondary to PCV2 infection typically consist of generalized lymphadenopathy in combination with one or more of the following: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc. At necropsy (Day 50), icterus, hepatitis, and nephritis were not noted in any groups. A gastric ulcer was noted in one Group 7 pig, but lymphadenopathy was not specifically examined for. Based on the presence of lesions that were consistent with PCV2 infection, three groups had at least one pig tentatively diagnosed with PCV2 (PMWS). Group 8, which received two doses of killed vaccine, had 20% tentatively diagnosed with PCV2, while Group 7 and Group 4 had 13.3% and 6.7%, respectively, tentatively diagnosed with PCV2. The mean % lung lesion scores varied between groups at necropsy. Groups 1, 2, 3, 4, 6 and 10 had low % lung lesion scores that ranged from 0.11±0.38% to 0.90±0.15%. As expected, Group 9, the challenge control group, had the highest mean % lung lesion score (10.81±23.27%). In four groups, the mean % lung lesion scores were elevated due to one to three pigs in each of these groups having very high lung lesion scores. The lung lesions were red/purple and consolidated. Typically, lung lesions associated with PMWS are described as tan, non-collapsible, and with interlobular edema. The lung lesions noted in this study were either not associated with PCV2 infection or a second pulmonary infectious agent may have been present. Within the context of this study, the % lung lesion scores probably do no reflect a true measure of the amount of lung infection due to PCV2. Likewise, tentative diagnosis of pneumonia may have been over-utilized as well. Any pigs with lung lesions, some as small as 0.10% were listed with a tentative diagnosis of pneumonia. In this example, there was no sufficient difference between groups with respect to gross lesions and % lung lesions on which to base vaccine efficacy.
[0161] IHC results showed the largest differences between groups. Group 1 (16 μg rORF2—IMS 1314) had the lowest positive IHC results for PCV2 antigen (0%); while Groups 9 and 10 had the highest positive IHC results with incidence rates of 100% and 93.3% respectively. Groups 3, 5, 6 and 7, which received 16, 4, 1 or 0.25 μg of rORF2 antigen, respectively, adjuvanted with Carbopol, had IHC positive rates of 20%, 20%, 40% and 46.7%, respectively. Group 2, which received two doses of 16 μg vORF2 adjuvanted with Carbopol had an IHC positive rate of 6.7%, while Group 4 which received only one dose of the same vaccine, had an IHC positive rate of 13.3%. Due to the objective nature of this test and the fact that IHC results correlated with expected results, IHC testing is probably one of the best parameters on which to base vaccine efficacy.
[0162] Thus in one aspect of the present invention, the Minimum Protective Dosage (MPD) of PCV2 rORF2 antigen adjuvanted with Carbopol in the CDCD pig model in the face of a PCV2 challenge is determined Groups 3, 5, 6 and 7 each received two doses of rORF2 antigen adjuvanted with Carbopol, but the level of rORF2 antigen varied for each group. Groups 3, 5, 6 and 7 each received 16, 4, 1 or 0.25 μg of rORF2 antigen respectively. In general, decreasing the level of rORF2 antigen decreased PCV2 antibody titers, and increased the mortality rate, mean % lung lesions, and the incidence of IHC positive tissues. Of the four groups receiving varying levels of rORF2—Carbopol, Groups 3 and 5, which received two doses of 16 or 4 μg of rORF2 antigen, respectively, each had an IHC positive rate of only 20%, and each had similar antibody titers. Overall, based on IHC positive results, the minimum protective dosage of rORF2 antigen administered twice is approximately 4 μg.
[0163] In another aspect of the present invention, the antigenicity of recombinant (rORF2) and VIDO R−1 (vORF2) PCV2 antigens were assessed. Group 2 received two doses of 16 μg vORF2 and Group 3 received two doses of 16 μg rORF2. Both vaccines were adjuvanted with Carbopol. Both vaccines were found to be safe and both had 0% mortality rate. Group 2 had a PCV2 antibody titer of 2507 on Day 25, while Group 3 had a PCV2 antibody titer of 1503. Group 3 had a lower mean % lung lesion score than Group 2 (0.11±0.38% vs. 0.90±0.15%), but Group 2 had a lower IHC positive incidence rate that Group 3 (6.7% vs. 20%). Overall, both vaccines had similar antigenicity, but vORF2 was associated with slightly better IHC results.
[0164] In yet another aspect of the present invention, the suitability of two different adjuvants (Carbopol and IMS 1314) was determined Groups 1 and 3 both received two doses of vaccine containing 16 μg of rORF2 antigen, but Group 1 received the antigen adjuvanted with IMS 1314 while Group 3 received the antigen adjuvanted with Carbopol. Both groups had essentially the same ADWG, essentially the same incidence of clinical signs post-challenge, the same mortality rate, and essentially the same mean % lung lesions; but Group 1 had an IHC positive rate of 0% while Group 3 had an IHC positive rate of 20%. However, Group 3, which received the vaccine adjuvanted with Carbopol, had higher IFAT PCV2 titers on Days 25, 32, and 50 than Group 1, which received the vaccine adjuvanted with IMS 1314. Overall, although the PCV2 vaccine adjuvanted with IMS 1314 did provide better IHC results, it did not provide overwhelmingly better protection from PCV2 infection and did induce injection site reaction. Whereas the PCV2 vaccine adjuvanted with Carbopol performed nearly as well as the IMS 1314 adjuvanted vaccine, but was not associated with any adverse events.
[0165] In still another aspect of the present invention, the feasibility of PCV2 ORF2 as a 1 ml, 1 dose product was determined Groups 2 and 4 both received 16 μg of vORF2 vaccine adjuvanted with Carbopol on Day 0, but Group 2 received a second dose on Day 14. Group 4 had a slightly higher ADWG and a lower mean % lung lesions than Group 2, but Group 2 had higher IFAT PCV2 titers on Day 25, 32 and 50, and a slightly lower incidence rate of IHC positive tissues. All other results for these two groups were similar. Overall, one dose of vORF2 adjuvanted with Carbopol performed similar to two doses of the same vaccine. | The present invention relates to the use of an immunogenic composition that comprises a porcine circovirus type 2 (PCV2) antigen for treatment of several clinical manifestations (diseases). Preferably, the clinical manifestations are associated with a PCV2 infection. Preferably, they include lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes. Moreover, the clinical symptoms include lymphadenopathy in combination with one or a multiple of the following symptoms in pigs: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis and (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc. Furthermore the clinical symptoms include Pia like lesions, normally known to be associated with Lawsonia intracellularis infections. | 2 |
BACKGROUND OF THE INVENTION
1. Field Of The Invention
This invention relates to flush assemblies for toilets. More particularly, the invention relates to a means which prevents opening of the water inlet valve to the toilet flush tank until a flush cycle is deliberately initiated, thereby preventing continued loss of water from the flush tank in the event there should be a leak from the tank caused, for example, by a malfunction in either the water inlet valve or the water outlet valve from the tank.
2. Description Of The Prior Art
A large variety of toilet flush assemblies are known in the prior art. Most of the toilet flush assemblies currently in use, especially in residential applications, utilize a float assembly to control opening and closing of the water inlet valve to the flush tank. When a flush handle is operated to open the flush valve for releasing water from the tank, the float drops, permitting a water inlet valve to open to enable water to flow into the tank and refill it. As the level of water in the tank rises, the float also rises and eventually shuts off the water inlet valve, precluding further flow of water into the tank. However, it is not uncommon for a leak from the tank to develop, e.g. past the water outlet valve, whereby the level of water in the flush tank gradually falls, resulting in lowering of the float and opening of the water inlet valve to introduce more water into the flush tank. This cycle repeats continuously so long as the leak remains unrepaired. Over time, a substantial amount of water is wasted.
Most people repair these leaky toilets as soon as they are discovered. However, some leaks may not be readily apparent, or a needed repair may not be made for other reasons, with the result that a substantial amount of water is lost through leaky toilets.
Numerous solutions have been offered in the prior art to prevent continued loss of water in the event that a leak should develop from a toilet flush tank. Examples of such efforts are shown in the patents submitted with the information disclosure statement filed herewith. These prior art systems provide means which act on the float to prevent the float from moving to open the water inlet valve except when a deliberate flush cycle is initiated. However, these prior art systems are relatively complicated and expensive in construction, and some of them may not be reliable in operation. Many of them also require extensive modification of the conventional flush system, and cannot be conveniently retrofitted into existing systems.
Moreover, since the prior art systems work by retaining the float in an elevated position, they are incapable of functioning to prevent continued leakage if the float never returns to its elevated position. These prior art systems therefore cannot prevent leakage of water from the flush tank in the event of a catastrophic failure of the flush outlet valve, or leakage of water into the float, or other eventuality which prevents return of the float to its normal elevated position, or even a malfunction in the usual water inlet valve.
Accordingly, there is need for a simple and inexpensive means which is reliable in operation and which prevents continued loss of water in the event of leakage from a toilet flush tank. There is also need for such a device which prevents continued loss of water in the event of a catastrophic failure of the flush outlet valve, or other cause for failure of the float to return to its elevated position for closing the water inlet valve.
SUMMARY OF THE INVENTION
The present invention provides a simple, reliable and inexpensive means which prevents opening of a water inlet valve to a toilet flush tank until the flush handle is deliberately operated. This prevents continual loss of water in the event of a leak, since the water inlet valve will not open to introduce additional water until the flush valve is deliberately operated. In contrast, when a leak develops in a conventional flush system, the water level drops in the flush tank, resulting in a lowering of the float, which in turn results in opening the water inlet valve to let more water into the tank, and therefore more water to leak from the system.
The means of the invention comprises a detent which acts either on an inlet valve or on a float which controls an inlet valve to keep the inlet valve closed until a flush cycle is deliberately initiated.
In a preferred form of the invention, the detent is an hydraulic mechanism that comprises a piston reciprocable in a cylinder, wherein the piston is biased into a first position to maintain the inlet valve closed, and upon actuation of the flush actuator is movable to a second position to enable the inlet valve to open. The hydraulic mechanism preferably includes a delay feature which delays for a predetermined interval of time movement of the piston from its second position to its first position. The period of delay is selected to enable the inlet valve to remain open long enough to introduce a predetermined quantity of water into the flush tank, but after the delay the piston will move to its first position to close the inlet valve regardless of whether there is any water in the tank. The hydraulic mechanism thus prevents continued loss of water from the flush tank in the event there should be a malfunction in either the inlet valve or the flush outlet valve, or a leakage of water from the tank due to some other cause.
In a first embodiment of this form of the invention, the hydraulic mechanism is positioned immediately downstream of and adjacent to a primary inlet valve, and a float controlled secondary inlet valve is positioned downstream of the hydraulic mechanism and primary inlet valve. An actuator means is connected between the flush actuator and the primary inlet valve to open the inlet valve to introduce water into the cylinder and move the piston from its first position to its second position. When the flush actuator is operated, an outlet valve from the tank is opened to release water from the tank, causing the float to fall and thereby open the secondary inlet valve to reintroduce water into the tank. If the system is operating properly, the outlet valve will close, enabling the tank to fill with water, and causing the float to rise to close the secondary inlet valve. During the time the tank is filling with water, the piston is moving from its second position to its first position in accordance with the delay feature, so that it will contact the primary inlet valve and move it to its closed position to prevent further inflow of water into the tank. Closing of the primary inlet valve by the hydraulic mechanism thereby prevents further flow of water into the tank and continued leakage of water from the tank in the event the float fails to close the secondary inlet valve or water leaks from the tank due to some other cause.
In accordance with a second embodiment of this form of the invention, there is only one inlet valve to the flush tank, normally held closed by a float mechanism and by the hydraulic detent mechanism of the invention. An actuator means is connected between the flush actuator and the hydraulic mechanism to move the hydraulic mechanism from a first position blocking opening movement of the inlet valve to a second position enabling the inlet valve to open when a flush cycle is initiated. Initiation of a flush cycle also opens an outlet valve from the tank, to release water from the tank, resulting in the float moving to a position to enable the inlet valve to open. The hydraulic mechanism in this embodiment also includes a delay feature which delays return of the hydraulic mechanism to its valve blocking position so that the inlet valve can remain open long enough to introduce a predetermined quantity of water into the flush tank. However, following the predetermined delay interval, the hydraulic mechanism moves to close the inlet valve regardless of the level of water in the tank, thus preventing continued loss of water from the tank in the event there is a malfunction in the outlet valve or leakage from the tank due to some other cause.
In another form of the invention, the detent comprises a mechanical plunger biased into a first position to block opening movement of the inlet valve, and is movable by an actuator means connected between the detent and the flush actuator to a second position in unblocking relationship to the inlet valve. The detent is latched in its second position so that it cannot return to its first position because of release of the actuator means. The inlet valve is controlled by a float mechanism which normally holds the inlet valve closed, but which moves to enable the inlet valve to open when the level of water in the tank falls after the outlet valve is opened. The detent is latched in its second position, and is unlatched by the float mechanism when the float returns to its position to close the inlet valve.
In a further form of the invention, a mechanical detent is biased into a first position to block opening movement of a float mechanism which controls operation of the inlet valve, and is movable to a second position by actuator means connected between the flush actuator and the detent. In its first, blocking position the detent engages the float mechanism to hold it in a valve closing position to thereby prevent opening of the inlet valve and introduction of water into the flush tank until a flush cycle is deliberately initiated. In this form of the invention, the float mechanism includes a float arm, and the float arm may have an articulated or hinged connection between its ends to enable the float to fall with the water level, independently of movement of a rear portion of the float arm which holds the inlet valve closed. This minimizes stress on the detent and float arm assembly in the event of a leak occurring in the system. The articulated joint in the float arm enables the free end of the float arm to pivot only in a downward direction, so that when the water level rises it will elevate the float and the float arm to close the inlet valve. The articulated joint between the ends of the float arm is intended merely to prevent or relieve stress on the float assembly and detent mechanism when the water level falls due to a leak. The pivot is irrelevant when the flush valve is deliberately operated, since the detent will be released to enable the entire float arm to pivot downwardly under the weight of the float.
The invention also has utility in other systems which use a diaphragm or other means to close the inlet valve following a flush cycle, and is not limited to use with float actuated systems. In these other systems, the detent of the invention acts directly on an inlet valve to prevent flow of water into the flush tank except following a deliberate flush cycle.
The invention thus applies to all types of flush valve assemblies, including those which utilize floats, and those which use other means for closing the water inlet valve following a flush cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects and advantages of the invention, will become apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
FIG. 1 is a top perspective view of a typical toilet flush assembly incorporating therein one embodiment of the present invention;
FIG. 2 is an enlarged fragmentary view in elevation, with portions shown in section, of a preferred form of water inlet flow control mechanism according to the invention wherein a primary inlet valve is positioned upstream of the usual valve and controlled by the float, and a hydraulic detent mechanism is used to keep the valve closed until a flush cycle is initiated;
FIG. 3 is a further enlarged fragmentary view in elevation, with portions shown in section, depicting a first form of actuator to open the primary inlet valve;
FIG. 4 is an enlarged fragmentary sectional view in elevation similar to FIG. 3, showing a second form of actuator for initiating opening movement of the primary water inlet control valve;
FIG. 5 is a view similar to FIG. 2, showing a different type of hydraulic mechanism and system for controlling operation of the primary water inlet control valve;
FIG. 6 is a top plan view of a portion of a flush tank wall, showing a typical conventional flush handle and flush rod assembly;
FIG. 7 is a top plan view showing a first form of detent actuating mechanism according to the invention applied to the flush actuating assembly of FIG. 6;
FIG. 8 is a rear view in elevation of the detent actuating mechanism of FIG. 7;
FIG. 9 is a top exploded view of a second form of detent actuating assembly for controlling opening of the water inlet valve at the initiation of a flush cycle;
FIG. 10 is a rear view in elevation of the actuating assembly of FIG. 9;
FIG. 11 is a rear view in elevation similar to FIG. 10, showing a variation of the actuating assembly;
FIG. 12 is a schematic view in elevation of a third form of water inlet control mechanism according to the invention, wherein the mechanism is applied to the inlet valve controlled by the float, showing the assembly in valve closed position;
FIG. 13 is a view in elevation of the assembly of FIG. 12, but showing the valve in open position;
FIG. 14 is a view similar to FIG. 13, showing a variation of the detent mechanism for holding the inlet valve closed, and depicting the valve in open position;
FIG. 15 is a view in elevation of a fifth form of water inlet control mechanism according to the invention, wherein the detent is mechanical in operation and is shown in blocking position to retain the water inlet valve in closed position;
FIG. 16 is a view of the assembly in FIG. 15, showing the detent moved to an unblocking position and the water inlet valve open following downward movement of the float in response to a flush cycle;
FIG. 17 is a view similar to FIG. 16, showing a variation of the mechanical detent, with the detent in a non-blocking position and the inlet valve open;
FIG. 18 is a view similar to view 17, but showing the valve in closed position and the detent in a forwardly biased position to block opening movement of the water inlet valve;
FIG. 19 is a top plan view of the bifurated plunger used in the detent of FIGS. 17 and 18;
FIG. 20 is a side view in elevation of a further form of the invention wherein the mechanical detent acts on the float arm rather than on the water inlet valve, the assembly being shown in this figure in a valve open position with the float having moved downwardly in response to a flush cycle;
FIG. 21 is a top plan view of the assembly of FIG. 20;
FIG. 22 is a side view in elevation similar to FIG. 20, showing the rear portion of the float arm in position to close the water inlet valve, and showing the detent in blocking position to prevent opening movement of the valve-contacting rear portion of the float arm; and
FIG. 23 is a top plan view of the assembly of FIG. 22.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A toilet flush assembly is indicated generally at 10 in FIG. 1. The assembly includes a tank 11 for holding a quantity of water which is released to flush a toilet, not shown. A water supply tube 12 is connected with a suitable source of water, not shown, and flow from the supply tube 12 into the tank is controlled by a water inflow valve 13 positioned at the top of the tube 12. The valve is controlled by a float 14 and associated float arm 14a which moves about a pivot 15 to position a rear portion 16 of the float arm against an actuating button 17 that connects with the inflow valve to hold it against its seat. A flush rod 18 is connected for movement with a flush handle or lever 19 mounted outside the tank 11, and controls movement of a link 20 that is connected with a flap type flush valve 21 to raise the flap valve and open the outlet from the tank during a flush cycle. An overflow tube 22 is connected to the bottom of the tank adjacent the valve 21. The structure thus far described is conventional and illustrates one form of toilet flush assembly on which the present invention may be used. It should be understood, however, that the invention may also be used with those types of flush assemblies in which a float moves vertically on the water supply tube 12 to control opening and closing of the water inlet valve at the top of the tube.
The present invention comprises an actuator assembly 23 positioned inside the tank on the mounting shaft for the flush lever 19 for movement with the flush lever. The actuator assembly is connected through a cable 24 with a detent mechanism 25 that controls a primary water inlet valve 26 at the bottom of the supply tube 12 so that inflow of water to the tank is prevented except when a deliberate flush cycle is initiated.
The actuating mechanism 23 is best seen in FIGS. 7 and 8 and comprises a stationary mounting plate 27 held against an inner surface of the wall of tank 11 behind the flush lever 19. A rotatable follower plate 28 is positioned against the mounting plate 27 for rotation relative thereto and includes a pair of rearwardly projecting pins or prongs 29 that extend in closely spaced parallel relationship to one another on opposite sides, respectively, of the flush rod 18, so that when the flush lever 19 is rotated to cause upward swinging movement of the flush rod 18, the prongs 29 are constrained to follow the flush rod, thus causing rotation of the follower plate 28.
The cable 24 is secured to the mounting plate 27 by a connector 30, with the free, movable cable end or wire 31 of the cable extending into abutting relationship with a cable stop 32 carried by the follower plate 28. Thus, when the flush lever 19 is rotated downwardly to initiate a flush cycle, the flush rod 18 is pivoted upwardly, pushing along the prongs 29 and rotating the follower plate 28 in a clockwise direction (as viewed in FIG. 8), whereby the stop 32 pushes against the cable wire end 31, pushing the cable wire inwardly to actuate the detent 25 at the bottom of the inlet tube 12 to open the primary water inlet valve 26.
The detent mechanism 25 that is controlled by the cable 24 is seen best in FIGS. 2-5.
The preferred form of the invention shown in FIGS. 2-4 utilizes a spring biased detent 25 with a hydraulic timing device to maintain the primary inlet valve 26 closed until a flush cycle is initiated by depressing the flush lever 19. The primary inlet valve 26 is held in closed position by depressing valve pin 26a, and is moved to an open position by elevating the pin 26a. The valve 26 is of conventional construction and will not be further described herein.
To elevate the pin 26a for opening the valve 26, an abutment 33 is provided on the pin for cooperation with a lever 34 that is pivoted by extension of the cable wire 31 when the flush lever 19 is operated. Thus, depression of the flush lever 19 causes the flush rod 18 to elevate, rotating the follower plate 28 and pushing the cable wire 31 outwardly of its sheath to engage one end of the lever 34 to depress it, simultaneously raising the other end and contacting the abutment 33 to raise the pin 26a and open the primary inlet valve 26. The lever 34 is normally maintained in a position spaced from the abutment 33 by a compression spring 35 engaged against that end of the lever which is depressed by the cable wire 31. If desired, the end 31 of the cable may be enclosed in a water tight seal such as bellows 36 (FIG. 4).
The detent for holding the valve pin 26a depressed and keeping the primary inlet valve 26 closed until a flush cycle is initiated comprises a hydraulic mechanism including a cylinder 37 supported in the bottom of tube 12, with a piston 38 reciprocable therein. A first one way valve 39 in the bottom of the cylinder enables flow of water into the cylinder beneath the piston to raise the piston against the downward bias of a spring 40, and a second one way valve 41 at the upper end of the cylinder enables flow of water out through the upper end of the cylinder, but prevents reverse flow back into the cylinder through the upper end. A flexible annular bypass valve 42 is engaged between the outer surface of the cylinder and the inner surface of tube 12 to enable flow around the cylinder and through the inlet valve 13 that is controlled by the float.
In operation of this from of the invention, when the flush lever 19 is depressed to elevate the flush rod 18 and open the outlet valve 21 to enable the tank to empty, the follower plate 28 is caused to rotate by movement of the flush rod against the pins or prongs 29, causing the follower plate to push against the cable wire 31 and causing it to extend outwardly at the lower end of the cable to pivot the lever 34 and raise the pin 26a to open the primary inlet valve to enable flow of water to move upwardly past the valve 39, elevating the piston 38 against the bias of spring 40. Water above the piston flows outwardly through valve 41 at the upper end of the cylinder 37. When the piston reaches its upper limit of travel, the valves 39 and 41 close and flow through the cylinder 37 stops. Flow occurs around the cylinder past the valve 42. In this regard, it should be noted that the valve 39 and 41 have greater flexibility than valve 42 and thus open at a lower water pressure. Water flowing upwardly through the tube 12 thence flows through the valve 13, which is now open because of lowering of the float and movement of the actuator 16 away from valve button 17.
With the valves 39 and 41 closed, there is static hydraulic pressure within cylinder 37, and the spring begins moving the piston 38 downwardly in the cylinder, Controlled leakage of fluid past the piston results in a timed rate of descent of the piston, so that the inlet valve 26 remains open for a length of time necessary to refill the tank with water. The piston 38 then engages 26A, forcing it down to close the valve 26. This action occurs independently of the position or condition of the float, valve 13, or valve 21, thus ensuring that there cannot be further leakage from the tank in spite of failure of the float, or one or both of valves 13 and 21.
Assuming normal operation of the float and the valve 21, as the tank fills with water the float rises with the water level and gradually closes the valve 13 by depressing the button 17. Water pressure equalizes inside cylinder 37 as described before, whereby the spring 40 begins moving the piston 38 downwardly. Downward movement of the piston is possible because of predetermined leakage of water past the piston, either around its outer periphery or through one or more small openings provided through the piston, until the piston reaches the bottom of the cylinder after a predetermined time interval, engaging the end of pin 26a and pushing it downwardly to close the primary inlet valve. With the primary inlet valve 26 closed, it is not possible for additional water to flow into the tank until a flush cycle is again initiated by operating the flush lever. Thus, even if a leak should develop past the outlet valve 21, resulting in a lowering of the water level in the tank and dropping of the float, enabling the inlet valve 13 to open, no additional water can flow into the tank since the primary inlet valve 26 remains closed due to contact of the piston 38 with the valve pin 26a.
A modification of the actuator system for opening the primary inlet valve 26 is shown in FIG. 4, wherein the cable 24 extends to a housing 43 through which the cable wire end 31 extends into close proximity with the abutment 33 on valve pin 26a, for direct action on the valve pin rather than acting through an intermediate lever as in the embodiment of FIG. 3. The cable wire 31 is biased away from the abutment 33 by a spring 44, and the end 31 of the cable wire may be encased in a seal 36 such as that used in the embodiment of FIG. 3. In all other respects, this form of the invention functions the same as that described in relation to FIG. 3.
A modification of the invention of FIG. 2 is indicated generally at 45 in FIG. 5. In this form of the invention, the valves 39, 41 and 42 are omitted, and a plurality of openings 46 are provided through a lower end of the cylinder 47, with piston 48 being reciprocable in the cylinder and biased toward the bottom end thereof by spring 49.
In operation of this form of the invention, actuation of the flush lever 19 causes the cable wire 31 to extend from the bottom end of the cable 24, as previously described, pivoting lever 34 to raise valve pin 26a and open the primary inlet valve 26. Upon opening of this valve, water flows into the cylinder beneath the piston, forcing the piston upwardly in the cylinder 47, while the principal flow of water occurs through the openings 46 and around the cylinder. As the tank fills following a flush cycle, and the float rises, the abutment 17 is depressed to close the valve 13 that is controlled by the float, whereby flow through the tube 12 ceases and the pressure equalizes above and below the piston, enabling the spring 49 to force the piston downwardly into contact with the pin 26a to depress the pin and close the primary inlet valve 26. The primary inlet valve will remain closed even if the tank should empty due to a leak past the outlet valve 21, until a flush cycle is again initiated.
A variation of the actuator assembly 23 is indicated generally at 23' in FIGS. 9 and 10. In this form of the invention, a base plate 50 is first assembled on the flush handle mounting sleeve, and the mounting plate 27 and follower plate 28 are then assembled against the base plate 50. It will be noted that the base plate 50 has a cylindrical hub 51 on which both the mounting plate 27 and the follower plate 28 are rotatably positioned. A spring 52 is connected between the hub 51 and mounting plate 27 to bias the mounting plate 27 in a clockwise direction as viewed in FIG. 10. This resilient connection between base plate 50 and mounting plate 27 is intended to accommodate variations in the dimensions and assembly positions of the various components comprising the actuator to prevent stressing of the components, and to eliminate the need for carefully and accurately positioning all of the components to insure proper travel of the actuator elements. That is, the yieldable connection between mounting plate 27 and base 50 absorbs any misadjustment of parts when the flush lever 23 is depressed to elevate the flush rod 18, causing rotation of the follower plate 28 to actuate the cable. Thus, and with reference to FIG. 10, if the position of the end of the cable 24 is too close to the stop 32 in the at-rest position of the follower plate 28, subsequent depression of the flush lever and consequent rotation of the follower plate 28 would be hindered by contact between the stop 32 and the end of cable 24. This may interfere with proper operation of the flush mechanism. However, in accordance with the variation shown in FIGS. 9 and 10, improper adjustment between the cable end and the at-rest position of the follower plate 28 would be accommodated by the yieldable connection 52. Thus, and with reference to FIG. 10, clockwise rotation of the follower plate 28 could continue even after the stop 32 contacts the end of cable 24 due to the yielding of spring 52, which would enable plate 27 to rotate relative to plate 50. Otherwise, operation of the actuator 23' is normal due to the relatively high resistance of spring 52. In other words, in normal operation the mounting plate 27 remains stationary just as in the form of the invention previously described. However, if the stop 32 should contact the end of stationary cable 24 prior to full movement of the flush lever 19 and full rotation of the follower plate 28, the spring 52 yields to accommodate any further movement required of the flush components.
A different approach to this concept is indicated generally at 23" in FIG. 11. In this variation, a yieldable coupling 53 is interposed between the stop 32' carried by the follower plate 28, and the cable end 31 to absorb any misadjustment between the range of movement of follower plate 28 and the position of the end of cable 24. In this variation, a housing 54 is attached to the mounting plate 27 in place of the mounting bracket 30 previously utilized, and a plunger 55 reciprocable in the housing 54 engages the end 31 of the cable to push the cable when the follower plate is rotated. A spring 56 is interposed between the plunger 55 and stop 32' to absorb any rotation of follower plate 28 required to accomplish a flush cycle, in the event that cable 24 is positioned too close to the stop 32' to accommodate this full movement. Guide rod 57 extends from plunger 55 through an opening in stop 32' to permit reciprocating movement of the plunger relative to the stop when the spring 56 is compressed. The resistance of spring 56 is selected so that operation of the actuator is normal in the absence of any misadjustment between the at-rest positions of the follower plate 28 and cable 24.
In the modification 58 shown in FIGS. 12 and 13, the detent mechanism is applied to the valve 13 controlled by the float 14, and the primary inlet valve described in the preceding forms of the invention is eliminated. Thus, in this form of the invention, the valve button 17' is modified to have an extension 59 projecting from one side thereof for cooperation with a plunger 60 carried in cylinder 61 mounted to a frame or bracket 62 supported on the valve 13. A spring 63 biases the plunger 60 downwardly against the extension 59 to depress the button 17' and maintain the valve 13 closed until the plunger 60 is pulled upwardly against the bias of spring 63 by cable wire 31. The cable wire 31 is connected to be retracted, rather than extended, by operation of the flush handle 19, and to this end is connected to an actuating mechanism 23 or 23' such as previously described, except that the cable 24 is attached to the mounting plate 27 on the opposite side of the pivot axis of flush rod 18, and the cable wire end 31 is connected to the stop 32, so that when the follower plate 28 is rotated in a clockwise direction as shown in FIGS. 8 or 10, for example, the cable wire end 31 is extended or withdrawn from the cable 24 to exert a pulling force on the plunger 60 to retract it against the bias of spring 63.
The plunger 60 is connected through a viscous coupling in the cylinder 61 so that it may be quickly withdrawn upon retraction of the cable wire end 31, but upon return of the flush handle and the cable wire end 31 to their original positions, downward movement of the plunger 60 is damped so that there is a delay in return of the plunger 60 to its extended position to depress the valve button 17' to close the inlet valve 13. This insures that after initiation of a flush cycle and emptying of water from the tank, and lowering of the float arm 14a to open valve 13 to refill the tank, the valve 13 will not be closed until the tank has been refilled and the flush arm 14a returned to its position shown in FIG. 12. At this time, the viscous coupling is designed so that the plunger 60 will also engage the extension 59 to positively retain the valve button 17' depressed and the valve 13 closed, in spite of the subsequent position of the float arm 14a and actuator extension 16, as might be caused, for example, by a leak occurring from the tank and a lowering of the water level therein.
A variation of that form of the invention shown in FIGS. 12 and 13 is indicated generally at 65 in FIG. 14. As in the previously described forms of the invention, the valve 13 is held closed by engagement of a detent against extension 59 on valve button 17'. Opening of the valve 13 can be accomplished only by actuation of the flush handle and extension of cable end 31 to engage the extension 59 and raise the button 17' against the action of the detent engaged with the extension 59. In this form of the invention, the detent comprises an extension 66 on the housing of valve 13, which conveys fluid past one way valve 67 and into cylinder 68 beneath plunger 69 to raise the plunger in the cylinder against the bias of spring 70. This results in a quantity of water being trapped between plunger 69 and valve 67 in the cylinder 68, to prevent free return movement of the plunger under the action of spring 70 when the cable end 31 is withdrawn to permit downward closing movement of valve button 17'. A calibrated vent 71 exhausts fluid from beneath the plunger 69 to permit timed downward movement of the plunger and the detent arm 72 which engages extension 59 on button 17'. After the plunger 69 and detent arm 72 reach their bottom limit of travel, the button 17' is fully depressed to hold the inlet valve 13 closed until a subsequent flush cycle is initiated.
In contrast to the previously described forms of the invention, which utilize hydraulic detent mechanisms, that form of the invention shown in FIGS. 15 and 16 relies upon a mechanical detent 80 to hold the valve 13 closed until a flush cycle is deliberately initiated by depression of the flush lever 19. In this form of the invention, the valve button 17" is held in a depressed position, closing the inlet valve 13, by a plunger 81 that is biased forwardly into engagement with the valve button 17" by spring 82. It will be noted that the valve button 17" and plunger 81 have complementally shaped surfaces 83 and 84, respectively, which engage one another when the plunger 81 is in its forward position.
The plunger 81 is reciprocable in a housing 85 supported on the valve 13, and includes a stem 86 projecting rearwardly through the housing and having a stop shoulder 87 thereon which engages the end of housing 85 to retain the plunger in its retracted position after it has been fully retracted in the housing by pulling back on the cable end 31 upon actuation of the flush assembly.
Forward movement of the plunger 81 into engagement with valve button 17" is prevented until the water level in the tank rises and the float is elevated to lower the rearward portion 16' of the float arm to depress valve button 17" for closing valve 13, and to bring adjustable release member 88 into engagement with the tail or stem 86 to releases the stop 87 and permit the spring 82 to project the plunger 81 forwardly into engagement with valve button 17" to hold the valve button depressed and the valve 13 closed.
FIGS. 17, 18 and 19 show a variation 90 of the mechanical detent illustrated in FIGS. 15 and 16. In this form of the invention, the valve button 17 and actuator arm portion 16 of the float arm are essentially conventional, and a detent plunger arm 91 is reciprocable in a housing 92 positioned to one side of the valve button 17 so that the plunger is biased forward by spring 93 into blocking relationship to the valve button 17 when the valve button is depressed by elevation of the float 14 and downward movement of the actuating arm portion 16. It will be noted that a protrusion 94 may be provided on the underside of actuating arm portion 16 for contacting the valve button 17, and in this event the forward end of plunger 91 may be bifurcated at 95 to straddle the protrusion 94.
The plunger 91 has a tail or stem 96 which protrudes rearwardly from the housing 92 and is connected with the cable wire end 31 so that the plunger may be withdrawn upon retraction of the cable when the flush handle is operated to initiate a flush cycle.
When a flush cycle is initiated, and the tank empties of water, the float 14 falls to the position shown in FIG. 17, and because the plunger 91 has been retracted upon operation of the flush handle, the valve button 17 is enabled to elevate to the position shown in FIG. 17, with the bifurcated end 95 of plunger 91 resting against the side of valve button 17. As the tank fills with water and the float rises, the valve button 17 is depressed by actuator arm portion 16, whereby the plunger may again be moved forwardly by the spring 93 into blocking relationship over the valve button 17 to hold it closed as shown in FIG. 18. The plunger will remain in this position holding the inlet valve 13 closed until a flush cycle is again initiated.
A still further form of the invention is indicated generally at 100 in FIGS. 20-23. In this form of the invention, the float arm 14a' is articulated at a joint 101 between its ends which permits downward bending movement of the free end portion of the arm, as shown in FIG. 22, if the water level in the tank falls but a flush cycle has not been initiated, but prevents upward flexing movement beyond the position shown in FIG. 20 when the water level rises. This articulated joint thus enables the free end of the float arm and the attached float to drop with a lowered water level without imposing stress on that portion of the float arm that contacts the valve button 17 to hold the valve 13' closed, or to impose stress on the detent which engages the float arm to hold the rear portion thereof in a valve blocking position as depicted in FIGS. 22 and 23.
The float arm 14a' is mounted on a pair of brackets 102 carried by the housing for valve 13', and the rear actuating arm portion 16" of the float arm includes a center valve actuating finger 103 having a shaped nose 104 on its end. The finger 103 includes a shaped end portion for contacting the valve button 17 to close the valve 13' when the float arm 14a' is elevated.
The valve actuating arm portion 16" of the float arm is held in its valve closing position, as shown in FIGS. 22 and 23, by a plunger 105 which is biased forwardly by a spring 106 to bring the nose portion 107 of plunger 105 into overlying relationship to the shaped nose 104 on the valve actuating finger 103 of float arm portion 16". See FIGS. 22 and 23. In this position, the plunger 105 holds the float actuating arm portion 16" in the position shown to maintain the valve button 17 depressed and the valve 13' closed. Retraction of the plunger 105 by actuation of the flush handle releases the float arm to enable it to drop as shown in FIGS. 20 and 21, enabling the valve button 17 to rise and the valve 13' to open.
With the parts shown in the relationship illustrated in FIGS. 20 and 21, the shaped surfaces on the nose portions 104 and 107 are such that the float arm can elevate and move downwardly past the plunger 105 to the position shown in FIG. 22. In other words, the shaped surfaces enable portion 104 to slide past portion 107, pushing the plunger 105 back.
While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications may be made to the invention without departing from the spirit and intent of the invention as defined by the scope of the appended claims. | A leak preventing detent apparatus for a toilet flush valve assembly in which an inlet valve to a toilet flush tank is controlled by an inlet valve control device, and an outlet flush valve is controlled by a flush lever. The detent apparatus includes a follower member that is moved in response to movement of the flush lever at the initiation of a flush cycle, and a detent that is operative to prevent opening of an inlet valve except when a flush cycle is deliberately initiated. In a preferred embodiment, the detent member acts directly on the inlet valve to maintain it closed until a flush cycle is deliberately initiated. The detent member may be hydraulically damped to provide a timed delay of its movement into inlet valve closing position. Further, in some forms of the invention a primary inlet valve is provided upstream of the usual inlet valve that is controlled by an inlet valve control device, such as a float, and the detent apparatus effectively cooperates with the primary inlet valve to maintain it closed unless a flush cycle is deliberately initiated. In the preferred form of the invention, the leak preventing apparatus is capable of preventing inflow of water into a toilet flush tank regardless of the position or condition of the inlet valve control device, or the outlet flush valve from the tank, or the usual water inlet valve, unless the flush lever is operated to deliberately initiate a flush cycle. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of the filing of U.S. Provisional Patent Application No. 61/824,869, filed on May 17, 2013, the disclosure of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
The present application relates to the field of fiber optic communication and, more particularly, to optical packaging techniques and designs used for multiple wavelength transmitters.
In the past few decades, optics has gradually become the favored media for transmitting high bandwidths of information. Compared to electrical cabling, fiber optics can transmit modulated light for extreme distances with low loss and low distortion. As the bandwidth requirements in datacenters and between switches and routers have increased, optical links are becoming necessary in ever shorter domains. Thus gradually optics has migrated from long haul, to metro, and now to enterprise and datacenters. In previous decades the signal bandwidth through a fiber has increased generally by modulating the lasers faster and having higher speed photodetectors on the receiver. Thus the industry went from 622 Mbits/second to 2.5 Gb/s and then 10 Gb/s. But now it is becoming harder to have the direct line rate exceed 10 Gb/s or 25 Gb/s. Thus to get to higher speeds, it is generally necessary to put parallel channels within the same fiber, where 40 Gb/s, for example, is achieved using four lanes of 10 Gb/s.
This parallelism can be achieved in a number of ways. Most simply, one could use a ribbon fiber, where there is 10 Gb/s modulated light in each fiber. Alternatively, one could use a more advanced modulation scheme, where the signal has multiple levels, or is modulated in phase as well as amplitude thus achieving multiple bits per symbol. Perhaps the most practical way is to use multiple wavelengths of light, with each signal modulating a light beam of a different wavelength. Because the intrinsic bandwidth of an optical fiber is very high, all the different wavelengths can be multiplexed with a dispersive element such as a diffraction grating into a single fiber. At the receiver end, the wavelengths are demultiplexed and received separately using another matching grating and a photodiode array. Thus 40 Gb/s can be transmitted in four lanes of 10 Gb/s each, at four different wavelengths.
This Wavelength Division Multiplexing (WDM) approach has already been in use extensively in long haul or metro optical links. Typically 40 or 80 channels are multiplexed into one fiber. The problem with using this same technique for shorter distances is that the temperature of the lasers and the multiplexer must be accurately controlled as the optical wavelength of a laser and a multiplexer are both temperature-dependent. Typically in a semiconductor laser, the wavelength of generated light varies at about 0.1 nm per degree Centigrade. The optical passband of a wavelength multiplexer also varies with temperature, but at a slower rate of about 0.01 nm per degree Centigrade. To have 40 or 80 wavelengths all in the same fiber, within the 30 nm range than can be easily amplified using conventional erbium-doped fiber amplifiers, the wavelengths have to be closely spaced at 100 GHz (0.8 nm) or 50 GHz (0.4 nm) spacing. As the equipment temperature varies from −5 C to 75 C, without temperature control a laser would change wavelengths by 8 nm, and a multiplexer by 0.8 nm, in both cases enough to run over other channels. Thus all the optical components are carefully temperature controlled, either with heaters or thermoelectric Peltier coolers.
An alternative for smaller distance optical interconnects that eliminates the precise temperature control is to spread out the wavelength range beyond the 30 nm of an optical fiber span, reduce the number of channels, and also dramatically increase the wavelength spacing between lasers. For example, for 40 Gb/s applications, four 10 Gb/s channels are used over a 60 nm span, with wavelengths at 1270 nm, 1290 nm, 1310 nm, and 1330 nm. With 20 nm spacing, even if the output wavelength of the laser moves by 8 nm, it will not run over adjacent channels. The shift of the output wavelength of the multiplexer of 0.8 nm is inconsequential, so no cooling is necessary. However, one still has misalignment between the output wavelengths of the lasers and the passband center frequencies of the multiplexer. If the wavelengths of the laser output and the multiplexer passband center frequency are aligned at the midpoint of the temperature range, than at the low end of the temperature range, the laser wavelength is too short by 3.6 nm, and at the high end of the temperature range, the laser wavelength is too long by 3.6 nm.
To account for this variation of wavelength with temperature, multiplexers with semi-Gaussian or flat-topped passbands may be used, but such multiplexers tend to have increased insertion loss for passbands covering an appreciable portion of the wavelengths of a channel. For example, in practical implementations, the passband wavelength of the multiplexer may be “flat-topped,” allowing good multiplexing across a 2×3.6 nm or 7.2 nm temperature range. Unfortunately, when one fabricates a flat-topped multiplexer that goes from single mode inputs to a single mode output, the insertion loss is much higher than compared to a standard Gaussian multiplexer. Flat-topped multiplexers, while having a widened passband, therefore induce additional loss, which makes the transmitter inefficient and increases power consumption.
BRIEF SUMMARY OF THE INVENTION
Aspects of the invention provide a plurality of lasers coupled with a multiplexer having a temperature dependent passband wavelength shift matched to laser temperature dependent output wavelength shift. In some embodiments the multiplexer is of a “superthermal” design, with passband characteristics that change much more with temperature. This matches the wavelength drift with temperature of the multiplexer passband with the wavelength drift with temperature of the laser output, such that the wavelengths of the light from the light sources and the multiplexer passband vary together. This allows the use of a “Gaussian” rather than a “flat-topped” design in the grating multiplexer that is of much lower loss.
In some embodiments wavelengths of both the laser and the multiplexer passband vary together with temperature. In some embodiments the lasers and multiplexer output are not the subject of temperature control. In some embodiments an optional receiver that tracks the variation in wavelength, or in some embodiments simply allows for the variation, thus allows more channels, and many more channels in some embodiments, to be used at closer spacing, thus increasing the total bandwidth of the link.
One aspect of the invention provides a transmitter for a wavelength division multiplexing communication system, comprising: a plurality of laser light sources which output light, each of the laser light sources outputting light about different wavelengths, the wavelengths shifting with variation of temperature of the laser light sources; a planar lightwave circuit positioned to receive light from the laser light sources and combine the light, the planar lightwave circuit having a passband with a center wavelength that shifts with variation of temperature of the planar lightwave circuit, the shift in center wavelength with variation of temperature substantially matching half of the shift in wavelength of the light from the lasers with variation of temperature.
These and other aspects of the invention are more fully comprehended upon review of this disclosure.
BRIEF DESCRIPTION OF THE FIGURES
Aspects of the invention are illustrated by way of examples.
FIG. 1 shows a design for a 4×10 Gb/s multiwavelength source.
FIG. 2 shows a design for a further multiwavelength source, showing the AWG with a temperature adjustment section.
FIG. 3 shows aspects of designs for a “superthermal” multiplexer, where the region of the insert is modified to increase the thermal shift to match that of the laser diodes.
FIG. 4 shows the passband of a flat-top multiplexer and a Gaussian multiplexer.
FIG. 5 shows the passband characteristics of an embodiment of the invention, where a lower loss Gaussian design multiplexer tracks the wavelength drift of the laser and thereby provides lower loss multiplexing compared to the conventional flat top passband.
FIG. 6 shows an alternate design of the multiplexer where the region of the insert is not in the arms, but in the star region of the device.
FIG. 7 shows a further alternate design of the multiplexer.
DETAILED DESCRIPTION
Multiwavelength links generally have multiple light sources packaged with a multiplexer that combines light from these sources into a single output. The sources can be directly modulated lasers, or continuous wave lasers together with separate modulator elements, for example. The sources can also incorporate drivers with the modulators or with the lasers. The light from these multiple sources, each generally at a different wavelength, are generally coupled to a chip that multiplexes the light from all the sources into a single output.
This is schematically shown in FIG. 1 for a 4×10 Gb/s transmitter. The transmitter includes a laser diode chip 10 with a laser that sends a beam of light forward into a microlens 20 that in turn focuses the beam into a planar lightwave circuit (PLC) 40 . In some embodiments the laser output wavelength shift is about 0.1 nm per degree Centigrade. Behind the laser is a driver 30 , which provides electrical signals to the laser diode chip. Note that there are four sets of lasers, drivers, and microlenses on the assembly of FIG. 1 .
In some embodiments the lasers are distributed feedback (DFB) lasers. In various embodiments the lasers are of an InP based material, and may be for example of AlGaInAs/Inp or InGaAsP/InP. In some embodiments the microlenses are mounted on moveable arms, for example as discussed in U.S. Patent Application Publication No. 2012/0195551, entitled MEMs Based Levers and Their Use for Alignment of Optical Elements, and U.S. Patent Application Publication No. 2011/0013869, entitled Micromechanically Aligned Optical Assembly, the disclosures of which are incorporated by reference herein.
The PLC that muxes the light together is generally designed to have a passband wavelength dependence with respect to temperature which is the same as or substantially the same as that of the lasers. In some embodiments the temperature dependence may be half that of the lasers, or between half that of the lasers and the same as the lasers, or within 30% of that of the lasers. In many embodiments the PLC is made of glass, for example silica based, incorporating grooves filled with a polymer material in waveguides of the PLC. In some embodiments the polymer material is a silicone resin. In some embodiments the passband wavelength shift is about 0.1 nm per degree Centigrade. The typical operating temperature of the assembly is from −5 C to 75 C, and thus over 80 C temperature difference, one sees about an 8 nm shift in passband wavelength. As the PLC has a much greater passband wavelength shift with respect to temperature than would otherwise be expected, the PLC may be considered a “superthermal” device.
In some embodiments the superthermal device includes a groove structure filled with a material with change in refractive index with respect to temperature (dn/dT) different than the dn/dT of the core of the PLC. Preferably the dn/dT of the material is either a highly positive or highly negative dn/dT, such as the dn/dT for a silicone resin. This, for example, allows the PLC, for example an arrayed waveguide grating (AWG), to have a higher temperature dependent passband center wavelength shift that is much more closely matched to that of an active device, for example such as a semiconductor laser. By varying the groove geometries, devices with arbitrary dλ/dT can be achieved on the same silica platform. Integration with devices that have matched dλ/dT gives advantages of eliminating, in many cases, heating/cooling elements within the integrated module without compromising AWG design and performance.
FIG. 2 shows a further embodiment in accordance with aspects of the invention. The embodiment of FIG. 2 includes a plurality of semiconductor lasers 10 , for example DFB lasers. Light from each of the lasers is focused by a corresponding lens 25 into a corresponding input of an AWG 45 . The lasers and the AWG are coupled to a common substrate, with intervening substrates present in some embodiments.
The AWG has a section 42 , triangular in some embodiments, made in the waveguide arms that are etched out of a region of the glass in which gratings of the AWG are formed, and replaced with polymeric material with a different dn/dT than the dn/dT of the glass. In most embodiments the polymeric material, and the amount of polymeric material in each waveguide of the AWG, is selected such that the AWG is a superthermal AWG. In some embodiments the polymeric material, and its amount, are selected such that the dn/dT of the AWG matches the variation in output wavelengths with respect to temperature of the lasers. To reduce diffraction loss, in some embodiments the groove is replaced with divided grooves, for example in the form of multiple grooves, which does not allow the light to diffract considerably while in the unguided polymer. In various embodiments the waveguides may be widened to reduce loss. Though such configurations sometimes affect the polarization response of the AWG, this is generally not important for a multiplexer that operates only on a single polarization.
In general the wavelength sensitivity of a superthermal AWG is determined by the dn/dT coefficients of the waveguide and the groove filling material. The center wavelength (λ e ) of the passband of the AWG is determined by the equation below:
λ c =ΔL c /m*n c *(1+ n p *ΔL p /( n c *ΔL c )) (1)
where ΔL c is the length difference between each adjacent grating in the silica waveguide, n c is the effective refractive index of the silica grating waveguide, ΔL p is the length difference between each groove length for adjacent grating waveguide regions, n p is the index of refraction the groove filling material, and m is the grating order.
The temperature dependence of center wavelength is given below:
dλ c /dT= 1/ m *( dn c /dT*ΔL c +dn p /dT*ΔL p ) (2)
where typical dn/dT values (ignoring second order temperature dependence) are:
dn c /dT= 1.1×10 −5 /° C., and dn p /dT=− 37×10 −5 /° C.
Combining eq(1) and eq(2),
Δ L p =( m*dλ c /dT−dn c /dT*ΔL c )/( dn p /dT ) (3)
Δ L c =m*λ c /n c *{[1−( dλ c /dT )/λ c *n p *( dn p /dT )]/[1−( n p /n c )*( dn c /dT )/( dn p /dT )] (4)
By selecting an appropriate ΔL p value, the AWG can be made to have a dλ c /dT that matches that of other devices like semiconductor lasers that have approximately 10 times the temperature sensitivity.
For example, for a 10 channel 400 GHz spacing AWG to match a dλ/dT of approximately 100 pm/° C. of a laser, equations (3) and (4) may be used to calculate ΔL p to be −7.66 um (assuming a nominal center wavelength of 1.55 um, n c of 1.4561, n p =1.4, and m of 32).
A design of an AWG based on the above is shown in FIG. 3 . The AWG has 10 channels with 400 GHz spacing, and the refractive index contrast is 1.5% with a core geometry of 4 um×3.5 um. As one can see, ΔL p is a negative number, with a triangular region 61 decreasing in width from a bottom, shorter, waveguide 63 to a top, longer, waveguide 67 . To cover the 65 grating waveguides in the device, the bottom grating waveguide should have an extra length of the silicone region of 498 um compared to that of the top waveguide. As an easy way to implement this, straight waveguides of equal length can be inserted in the middle of the grating region of the AWG to accommodate a rectangular shaped etched trench that is filled with silicone. However, diffraction loss resulted from a long unguided silicone region in a single rectangle of this size may be unacceptable in many cases. Divided grooves 71 instead of a single groove 73 may be implemented to reduce diffraction loss. In this case, dividing the single rectangle into 100 equally spaced narrower rectangles, such that each silicone filled region is no more than Sum long along each grating waveguide, could improve the insertion loss of the device significantly.
FIG. 4 is a graph showing an example Gaussian passband response of a channel of a superthermal AWG in accordance with aspects of the invention. A first curve 140 shows an example Gaussian response of a superthermal AWG, while a second curve 100 shows an example flat-top passband response. As may be seen through a comparison of the two curves, Gaussian response has a higher peak, but passes light in a narrower range of wavelengths.
FIG. 5 shows the optical characteristics of such as system, where Gaussian passbands are used that shift with temperature. 140 is the Gaussian passband curve of the first filter while 110 is the laser wavelength matched to that filter at low temperature. Once the temperature increases, the laser wavelength moves to 130 , but the filter response moves the same amount to 150 . The match between the laser and the filter is maintained. Since the Gaussian filter has much lower loss than the flattop, the efficiency of the module is increased and the laser can run at lower power, saving power consumption.
Commensurately, one can increase the number of channels of this uncooled system and space them closer together. All the channels will drift up and down with temperature together, and one can use a demultiplexer to track this drift and appropriately lock on to the grid. This can be done in many ways. For example, the receiver can be made tunable by controlling the temperature of the demultiplexer. Since the demultiplexer does not generate heat, it can be thermally insulated from the environment and therefore only a small amount of power from a heater would vary the temperature substantially. This would tune the filter. This heater could be made local—for example on a polymer insert into the PLC, or it could heat the entire assembly. To track, a low frequency dither tone can be placed on one channel of the transmitter. The receiver would then detect this dither tone, and adjust the temperature of the receiver with heater power such that the dither would be maximized at the appropriate channel.
The region of different index can also be implemented in areas of the PLC other than the grating waveguides, for example the star region. FIGS. 6 and 7 show implementations where part of the slab of the PLC is etched out and replaced with polymer. The implementation is similar to the version where the grooves are in the grating region, except that the grooves here are concentrically shaped with respect to the center of the input slab region 81 , so that the light in the slab region enters the silicone filled grooves at or close to normal. The effect is that same in that the beam is steered with temperature causing the center wavelength of the multiplexer to shift much more dramatically with temperature.
Although the invention has been discussed with respect to various embodiments, it should be recognized that the invention comprises the novel and non-obvious claims supported by this disclosure. | A transmitter assembly incorporating multiple laser diodes that are wavelength multiplexed together using a planar lightwave circuit, and where the multiplexer's transmission spectrum depends on temperature at the same rate as the laser diodes. This allows a design for lower loss in the multiplexer and therefore is more power efficient. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to converting constant volume heating/air conditioning systems to reduce energy consumption.
2. Description of the Related Art
Multizone air conditioning/heating units have been used extensively in buildings and other spaces for occupant comfort, as well as for process temperature and humidity control. Beginning in the late 1940's, these units were widely placed into service.
With multizone units, several different zones (usually from two to twelve or so) were supplied with air from a centrally located air handling unit. The air handling unit typically had both heating and cooling sections, each of which acted on a portion of the circulating air. Based on the temperature sensed in a particular zone, the required air mixture of heated and cooled air was furnished. Mixing of the heated air and the cooled air was accomplished by regulating the amount of air flow through controllable position flow regulating vents. Multizone units were required by their design to transport a constant volume of air continuously during unit operation. That constant volume was designed to meet peak or worst conditions of the hottest and coldest days of the year. Those conditions occurred less than about five percent of the time. The fans in multizone units were required, though, to produce constant volumes of air based on these worst case conditions. Less than peak loads were met by regulating the mixture of heated and cooled air to achieve the desired temperature, based on sensed temperatures in the various zones.
For a considerable time, multizone and double duct constant volume units were almost exclusively the only type installed. The constant volume for production demanded considerable energy usage. This was not considered a problem so long as inexpensive energy was available. However, in the last twenty or so years, energy costs have risen considerably. Removal and replacement of installed multizone units by variable volume units was a possible technique of energy conservation, but this was available only at a considerable cost. As a result, there are a large number of high energy usage, constant air volume multizone heating/air conditioning units still in service.
SUMMARY OF THE INVENTION
Briefly, the present invention provides a new and improved air handling (heating/air conditioning) system with reduced energy consumption. The system is made by converting an existing air treating system of the type with a constant volume fan. The existing air treating system converted may be a unit of the conventional multizone type, or the bypass multizone type or a double duct unit. Whatever type of existing air treating system is converted, a new and improved air conditioning/heating system results with the present invention. The resulting system is achieved by installing a control system according to the present invention.
With the control system of the present invention, a thermostat detects air conditions in a zone. An air treating unit imparts required characteristics (heating or cooling) to air being moved by a fan based on conditions sensed by the thermostat. An air flow regulator or variable air volume unit controls the volume of moving air, again based on conditions sensed by the thermostat. Pressure of the air being moved by the fan is sensed at the air treating unit, and a fan speed controller adjusts the fan speed by reducing it as air pressure in the treating unit increases. The sensed air pressure increases as the air flow regulator reduces the air flow in response to lower need for heated or cooled air. Thus, fan speed is reduced according to reduced need for air flow, reducing power consumption by the fan and saving energy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a prior art multizone unit.
FIG. 2 is a schematic diagram of a prior art bypass multizone unit, also known as a Texas multizone unit.
FIG. 3 is a schematic diagram of a prior art duct (also called dual duct) unit.
FIG. 4 is a schematic diagram of a double duct mixing box used with the unit of FIG. 1.
FIG. 5 is a diagram of thermostat pneumatic pressure versus flow control damper position relating to prior art systems of FIGS. 1 through 4.
FIG. 6 is a schematic diagram of a multizone unit after conversion to a variable volume unit according to the present invention.
FIG. 7 is a schematic of a bypass or Texas multizone unit after conversion to a variable volume unit according to the present invention.
FIG. 8 is a schematic of a double duct box or terminal after conversion to a variable volume terminal according to the present invention.
FIG. 9 is a diagram of thermostat pneumatic pressure versus flow control damper position illustrative of the operation of the systems shown in FIGS. 6 through 8.
FIG. 10 is a schematic diagram of a multizone unit zone where heating is not required after conversion according to the present invention.
FIG. 11 is a schematic of a double duct box or terminal where heat is not required after conversion according of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
At the outset, a brief explanation of prior art constant volume heating/air conditioning or air handling systems is given for the purposes of a more detailed background. In FIG. 1 of the drawings, a typical prior art standard multi-zone air handling unit M is shown. The multi-zone unit M receives return air after suitable air filtration, as indicated at 20, which is provided to a constant volume fan 22. The constant volume fan 22 after activation by a starter 24 causes the return air to pass into a plenum 25 where air flow is divided into substantially equal portions. A first portion of the air flow from the fan 22 passes into a cold deck 26, while the other portion of the air goes into a hot deck 28.
In the cold deck 26, a cooling coil 30 cools air flowing through it. The cooling coil may be of any conventional type, such as a chilled water unit, or a direct expansion type, or other suitable type to provide the required amount of cooling. A thermostat 32 with a sensing bulb 34 is provided in the flow of air downstream from the cooling coil 30 to sense air temperature. Thermostat 32 provides signals, typically pneumatic, to a control system, shown schematically as a pneumatically controlled valve 36, to cause the cooling coil 30 to impart the required amount of cooling to the air flowing through it.
In the hot deck 28, a heating coil 40 heats air flowing through it. The heating coil 40 may be of the type driven by steam, hot water, electric heat or other suitable heat source to provide the required heating. A thermostat 42 with a sensing bulb 44 is provided in the flow of air downstream from the heating coil 40 to sense air temperature. The thermostat 42 provides control signals, usually pneumatic, to a control system, shown schematically as a pneumatically controlled valve 46, to cause the heating coil 40 to impart the required amount of heat to the air passing through it.
The emerging heated air stream from the hot deck 28 and cooled air stream from the cold deck 26 are passed to a damper section 50. In the damper section 50, for each zone of the multizone unit M being served a set of vanes as shown at 52 are provided. The vane set 52 for a particular zone is mounted on a common activator or actuator shaft 54 located in the flow path across air streams from the hot deck 28 and the cold deck 26. The vanes 52 serve to mix or blend the volume of air to maintain the desired temperature for that particular zone. The vanes 52 for each zone include a suitable number of heat zone flow regulating vanes 52h and a suitable number of cold zone flow regulating vanes 52c. The vanes 52h and 52c for a particular zone mounted on the common shaft 54 undergo concurrent movement in opposite directions as the shaft 54 is moved.
The relative movement of each shaft 54 is controlled by a damper motor 56. Damper motor 56 is in turn controlled by a signal from a thermostat 58 in a zone associated with that particular set of vanes 52. The mixture or blending of air is determined by the relative degree of opening and closing of the associated vanes 52h and vanes 52c for that zone. As the amount of heating required increases, the relative position of the vanes 52h and 52c is adjusted, due to movement of the shaft 54 by damper motor 56, to increase the amount of air permitted to flow through the heat zone vanes 52h. Concurrently the movement of cooled air from the cold deck 26 is inhibited by corresponding movement of the cold zone vanes 52c to a more relatively closed position. When more cooling is required, flow of air through vanes 52c is increased by movement of shaft 54, with consequent reduction of air flow through vanes 52c.
The mixed or blended air is conveyed from the vane set 52 of each damper section 50 by ducts, one of which is indicated schematically at 60. The number of separate zones available on a multi-zone unit is determined by the physical size of the unit. Typically from two to twelve zones are supplied by a single multi-zone unit M. Thus, a set of from two to twelve sets of vanes are normally present, one for each zone having a thermostat 58.
In FIG. 2, a typical prior art bypass multizone unit B is shown. The bypass multizone unit B is a variation of the standard multizone unit M of FIG. 1. Thus, structure of like construction and operating in a like manner to that of FIG. 1 bears like reference numerals. In the bypass multi-zone unit B (FIG. 2), a bypass deck 27 to pass return air at its return temperature is provided. The bypass unit B has no heat deck, since bypass deck 22 is provided in place of the heat deck 28 present in a standard multi-zone unit M (FIG. 1). Usually some sort of air flow restrictor is provided in the bypass deck 27 to cause an air pressure loss to occur in the bypass deck 27 comparable to that occurring in the cold deck 26. This is done to maintain a relatively constant air flow while blending air streams at vanes 52. Heating for the bypass multizone unit, which is also known as a Texas multi-zone unit, is provided by a separate set of heating devices 62, located in each of the ducts 60. The heating devices 62 may be driven by steam, hot water, electrical heat or other suitable heat source. A control system indicated schematically by a valve 64 regulated by the thermostat 58 controls the amount of heating imparted to the air downstream from the vanes 52.
In FIG. 3, a typical prior art double duct system D is shown. The double duct system D has a number of common elements to that of the standard multi-zone unit M, and accordingly structure of like construction and operating in a like manner to that of FIG. 1 bears like reference numerals. In the double duct system D, the heated air from the hot deck 28 passes into a hot air duct system 70. Similarly, the cooled air from the cold deck 26 passes through a cold air duct 72. The hot duct 70 and cold duct 72 extend from the main unit or plenum 25 to each of the individual zones. In each of the individual zones, an individual terminal blending unit U is located, typically near the space being served.
At each such location a double duct mixing box U (FIG. 4) is located. The mixing box U receives warm air at an inlet from duct 70 and cold air an inlet from duct 72. A flow regulating valve having a commonly actuated warm air flow damper 74 and cold air flow damper 76 on a common shaft 78 is selectively positioned to control the relative flows of warm air from the warm air duct 70 and cold air from the cold air duct 72 into a mixing zone 80. The relative amounts of warm air and cold air flowing into the mixing zone 80 as indicated schematically by arrows is controlled by a damper motor 81. Damper motor 81 operates under control of temperature conditions sensed by the thermostat 58. The incoming warm and cold air passes from the mixing zone 80 through a volume control device shown schematically at 82, and therefrom through an outlet 84 into the zone being served by that particular mixing box U.
In FIG. 5 of the drawings, a schematic diagram of common operating characteristics of the prior art constant volume air handling or heating/air conditioning units of FIGS. 1 through 4 is shown. As indicated by a performance characteristic line 90, the hot deck damper function, whether performed by the vanes 52 (FIGS. 1 & 2) or by the hot zone damper 74 (FIG. 4) of the mixing box U, is in a fully closed position as indicated at 90a at low signal pressures from the thermostat 56. At a certain transition temperature, the performance of the hot zone damper, as indicated at region 90b of FIG. 5, begins to gradually allow increasing amounts of heated air to flow through the hot zone damper until a pneumatic signal pressure is reached, as indicated at 90c, at which point the hot zone or hot deck damper becomes fully open.
Conversely, as indicated by a performance line or characteristic 92, the cold deck or zone damper at signal pressures from the thermostat 58 corresponding to closed hot deck vanes 52h or damper 74 begins in a fully opened position as indicated at a region 92a. This continues until a transition temperature established at thermostat 58 is reached. At this point, as indicated by performance characteristic line 92b, the cold deck damper, whether the vanes 52 (FIGS. I & 2) or the cold deck damper 76 of the mixing box U (FIG. 4), begins gradually to increasingly close and restrict flow of cold air in response to changing signal pressure from the thermostat 58. This continues to restrict the flow of cold air until a transition signal pressure or temperature sensed by the thermostat 58 is reached, as indicated at region 92c, at which point the cold deck damper is fully closed so that no cold air is allowed to flow through the vanes 52 or 52c the mixing box U. The region 92c with cold air flow blocked corresponds to the region 90c with hot air flow fully open.
THE PRESENT INVENTION
Turning to FIG. 6 of the drawings, a multizone air conditioning unit M-1 in accordance with the present invention after having been modified with a control system C of the present invention is shown. The multizone unit M-1 is a modified or converted system resulting from modification of the system M of FIG. 1. Accordingly, structure of the unit M-1 performing in a like manner to that of the unit M of FIG. 1 bears like reference numerals.
The fan 22 of the multizone unit M-1 is driven by a variable speed drive 100. The variable speed drive 100 is connected to a static pressure sensor 102 which is connected at an inlet port 104 to sense static air pressure conditions in the plenum 25 of air leaving the fan 22. As static pressure is sensed by the sensor 102 at inlet 104 increases, the variable speed drive 100 causes the speed of operation of the fan 22 to decrease. In a corresponding manner, as static pressure sensed by the sensor 102 decreases, the variable speed drive 100 causes the speed of operation of the fan 22 to increase.
The thermostat 58 of the multizone unit M-1 is connected through a relay 106 receiving power from a pneumatic main 108 to the damper motor 56 controlling position of the vanes 52. A suitable type of relay 106 is a snap-acting or two position relay, such as a model RP-471A from Honeywell, Inc., although it should be understood that other types might also be used.
As will be set forth, the relay 106 causes the vanes 52h and 52c to assume either of two mutually exclusive positions. These two positions depend on the temperature sensed by the thermostat 58. As indicated in FIG. 9, when the temperature sensed by the thermostat 58 is above an established threshold temperature as indicated at 110, the relay 106 causes the cool zone vanes 52c to be fully open, as indicated by a performance curve 108 and the hot zone vanes 52h to be fully closed. Conversely, when the temperature sensed by the thermostat 58 is less than the established threshold 110, the relay 106 causes the vanes 52c and 52h to reverse positions. Thus, the heat zone vanes 52h are fully open as indicated by performance curve 114 and the cold zone vanes 52c are fully closed when the thermostat 58 senses temperature conditions above the threshold temperature indicated at 110.
A set of variable air volume or flow regulating vanes 120 (FIG. 6) are located in each duct 60 of the multizone unit M-1. The vanes 120 control the volume of air moving in duct 60 based on temperature conditions sensed by the thermostat 58. The position of the vanes 120 is set by a damper motor 122 driven by a reversing relay or control 124. The reversing relay is, for example, of the type sold as model RRC 1504 by Krueter Manufacturing Corporation, although other types may also be used for this purpose. The reversing relay 124 is driven by a signal from the thermostat 58 indicative of temperature in the zone being serviced.
As the thermostat 58 indicates either increased heating or increased cooling is needed, the reversing relay 124 and the damper motor 122 allow increasing volumes of air to flow from the multizone unit M-1 through the ductwork 60. Similarly, when the thermostat 58 indicates reduced cooling or heating is needed, the reversing relay 124 and damper motor 122 reduce the volume of air permitted to flow from the unit M-1 through the duct 60.
As the vanes 120 move to a more closed position in response to the damper motor 122, the static pressure sensed at the inlet port 104 by sensor 102 increases.
As can be seen in FIG. 9, the variable air volume or flow regulating unit 120, as indicated by performance curve 126, reduces the static pressure and allows increasing volumes of cooled air to flow through open vanes 52c as the thermostat 58 senses the need for increased cooling. As noted above, the control or relay 106 causes vanes 52h to be closed when vanes 52c are open. Similarly, when thermostat 58 senses that increased heating is required, the flow regulating variable air volume vane unit 120 reduces static pressure, as indicated at 128, while increasing the volume of air permitted to pass through duct 60 from open heat vanes 52h. Again, when the vanes 52h are opened, the vanes 52c are closed by relay 106.
As has been set forth above, this in turn causes the variable speed drive 100 to reduce the speed of the fan 22. Thus, with the present invention, when the thermostat 58 senses reduced need for more heating or cooling in the zone being serviced, the flow regulating vanes 120 are adjusted in position, which in turn reduces the operating speed of the fan 22. The speed of operation of the fan 22 is related to the power consumed by that fan in a third power or cube relation. That is, increases in fan speed cause power consumption by that fan to increase according to the cube or third power of the increase. Thus, with the present invention, it can be seen that the control system incorporated in the multizone unit M-1 causes significant reductions in power consumption by the fan 22 which formerly operated as a constant volume fan.
In FIG. 7, a modified bypass multizone unit B-1 having incorporated therein a control system C of the present invention is shown. In the bypass unit B-1, like structure to that of the bypass unit B bears like reference numerals. As was the case in the multizone unit M-1, the fan 22 is driven by a variable speed drive 100 whose speed is governed by the static pressure senor 102 based on readings taken at the inlet port 104 within the plenum 25. The control system C of bypass multizone unit B-1 includes the control relay 106 like that of the multizone unit M-1, as well as the flow control regulating vanes 120 governed by the damper motor 122 and control relay 124. These elements are of like construction to that of the multizone unit M-1 described above. As is the case with the multizone unit M-1, the performance characteristics of the bypass zone unit B-1 are comparable to those shown in FIG. 9 and operation of the bypass unit B-1 under influence of the control system C occurs in the same manner described above.
Turning to FIG. 8 of the drawings, a mixing box U-1 for use with a double duct system like that shown in FIG. 3 of the drawings is shown. The mixing box U-1 is modified by incorporation therein of the control system C as shown in FIGS. 6 and 7 of the drawings.
Accordingly, like structure to that shown in other figures of the drawings bears like reference numerals where like functions are performed. In the mixing box U-1, the flow regulating vanes or variable air valve unit 120, controlled by the damper motor 122 and control relay 124, is located in the outlet ducting 84 from the mixing box U-1. The control relay 106 controls the position of the damper 74 and 76 of the mixing box U-1 based on the temperature conditions sensed by the thermostat 58 in accordance with the performance chart of FIG. 9 described above. Damper 74 is fully closed below threshold 110, while damper 76 is fully open. When the temperature sensed by thermostat 58 is above threshold 110, damper 76 is fully closed and damper 74 is fully open. Again, the variable air vanes 120 control the volume of air leaving the mixing box U-1, whether heated or cooled, as controlled by the relay 106, and allow the fan 22 to operate at reduced or increased speed, based on the need for volumes of air to maintain the desired temperature conditions in the zone being serviced by the thermostat 58.
In FIG. 10 of the drawings, a standard or modified bypass multizone unit B-2 according to the present invention is shown. In the unit B-2, like structure to that of the units M-1 and B-1 bear like reference numerals. The multizone unit B-2 is used in situations where there is no need for heating. In such situations, the vanes 52h for the hot or bypass zone are locked in the fully closed position, as indicated in FIG. 10, while the vanes 52c for the cold deck zone 26 are lock in the fully open position. The thermostat 58 in the zone being serviced adjusts the volume of air flowing from the treating unit through the damper motor 122, again reducing energy demand by the fan 22 based on temperature conditions sensed by the thermostat 58.
Finally, FIG. 11 of the drawings shows a modified mixing box U-2 used in conditions where no heated air is needed. In such a situation, the warm air duct 70 is capped or sealed, while the position of the cold air damper 76 in the cold air duct 72 is governed by the damper motor 81 based on temperature conditions sensed by the thermostat 58. Again, the relative amount of cold air flowing from the cold air duct 72 based on the temperature conditions sensed by the thermostat 58 govern the volume of air flowing through the mixing box U-2 and thus control the operating speed of the fan 22.
Having described the invention above, various modifications of the techniques, procedures, material and equipment will be apparent to those in the art. It is intended that all such variations within the scope and spirit of the appended claims be embraced thereby. | Constant volume multizone heating/air conditioning systems are converted to variable volume air conditioning systems. Energy conservation is achieved by converting the fan drive from one requiring constant volume air flow. Instead, the volume of air flow is governed by relative heating or cooling needs. Further, mixture of heated and cooled air to achieve the desired temperature is no longer required. Temperature sensors in a zone being heated/cooled detect actual temperature there. When the actual temperature indicates a need for cooling, the vent vanes of the system are opened and the heating vent vanes are closed. The fan speed and volume of air flow are then controlled to provide the required amounts of cooled air. Conversely, when heating is sensed to be needed, the heating and cooling air vent vanes positions are reversed and the fan speed regulated to supply the requisite amount of heated air. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No. 12/400,479, filed Mar. 9, 2009 (now U.S. Pat. No. 7,971,302 issued on Jul. 5, 2011), which is a non-provisional patent application of U.S. Provisional Patent Application Ser. No. 61/046,120, filed Apr. 18, 2008, each of which is incorporated herein by reference.
[0002] This is a continuation-in-part of U.S. patent application Ser. No. 13/052,898, filed Mar. 21, 2011, which is a continuation of U.S. patent application Ser. No. 12/400,497, filed Mar. 9, 2009, which is a non-provisional patent application of U.S. Provisional Patent Application Ser. No. 61/046,118, filed Apr. 18, 2008, each of which is incorporated herein by reference.
[0003] Priority of U.S. Provisional Patent Application Ser. No. 61/046,118, filed Apr. 18, 2008, incorporated herein by reference, is hereby claimed.
[0004] Priority of U.S. Provisional Patent Application Ser. No. 61/046,120, filed Apr. 18, 2008, incorporated herein by reference, is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0005] Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
[0006] Not applicable
BACKGROUND OF THE INVENTION
[0007] 1. Field of the Invention
[0008] The present invention relates to continuous batch washers or tunnel washers. More particularly, the present invention relates to an improved method of washing textiles or fabric articles (e.g. clothing, linen, etc.) in a continuous batch tunnel washer wherein the textiles are moved sequentially from one module or zone to the next module or zone including initial pre-wash zones, a plurality of main wash zones, a pre-rinse zone, and then transferred to an extractor that performs the final rinse and that removes water. More particularly, the present invention relates to an improved method of washing textiles in a continuous batch tunnel washer wherein a counter flow of wash liquor from one module or zone to the next module or zone is stopped, allowing for a standing bath. Chemicals are then added to separate soil from the goods and suspend the soil in the wash liquor. After a period of time, counter flow is commenced again to remove the suspended soil.
[0009] 2. General Background of the Invention
[0010] Currently, washing in a commercial environment is conducted with a continuous batch tunnel washer. Such continuous batch tunnel washers are known (e.g. U.S. Pat. No. 5,454,237) and are commercially available (www.milnor.com). There are also machines that do not counterflow. Continuous batch washers have multiple sectors, zones, stages, or modules including pre-wash, wash, rinse and finishing zone. Commercial continuous batch washing machines utilize a constant counter flow of liquor and a centrifugal extractor or mechanical press for removing most of the liquor from the goods before the goods are dried.
[0011] Currently, a counter flow is used during the entire time that the fabric articles or textiles are in the main wash module zone. This practice dilutes the washing chemical and reduces its effectiveness. Additionally, while the bath liquor is being heated, this thermal energy is partially carried away by the counter flow thus wasting energy while a desired temperature value is achieved.
[0012] A final rinse with any continuous batch washer is sometimes performed using a centrifugal extractor or mechanical press. In prior art systems, if centrifugal extraction is used, it is typically necessary to rotate the extractor at a first low speed that is designed to remove soil laden water before a final extract.
[0013] Patents have issued that are directed to batch washers, tunnel washers, rinsing schemes and the like. The following table provides examples.
[0000]
TABLE
Pat. No.
TITLE
ISSUE DATE
4,236,393
Continuous tunnel batch washer
Dec. 02, 1980
4,485,509
Continuous batch type washing
Dec. 04, 1984
machine and method for
operating same
4,522,046
Continuous batch laundry
Jun. 11, 1985
system
5,211,039
Continuous batch type washing
May 18, 1993
machine
5,454,237
Continuous batch type washing
Oct. 03, 1995
machine
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention improves the current art by reducing water consumption, improving rinsing capability, reducing the number of components required to perform the function of laundering fabric articles or textiles, and saving valuable floor space in the laundry.
[0015] The present invention reduces and/or combines zones, sectors, or modules and improves the method of processing the textiles. Rinsing is done in two zones, first in the continuous batch washer itself in a pre-rinse zone after the main wash. A final rinse is then done in a mechanical water removal machine such as a centrifugal extractor or mechanical press.
[0016] When the goods are initially transferred into the main wash modules, the counter flow of wash liquor into the modules is stopped allowing for a standing bath. Chemicals are added to separate the soil from the goods and suspend the soil in the wash liquor. If needed, the wash liquor to the separate module bath is raised in temperature to facilitate the release of soil from the goods and activate the chemicals.
[0017] Once the soil has been released from the textiles, there is no more work for the chemicals to perform. At this time, the process can be described as chemical equilibrium. At this point, water by counter flow is commenced to remove the suspended soil. This could be termed an intermediate rinse since the water counter flowing into the module or zone is cleaner than what is counter flowing out of the module or zone. When the goods have progressed in this manner through the tunnel to a point where no more wash chemicals are needed, then the water flowing into the module or zone begins the rinsing process. This rinsing is termed pre-rinse. A final rinse can be performed in a centrifugal extractor or mechanical press.
[0018] The process of the present invention uses fresh water in the extractor that can be supplied through an atomizing nozzle while the goods are being extracted at high speed (e.g. between about 200-1,000 g's). Because the free soil has already been removed in the pre-rinse zone, the spray rinse while extracting will not re-deposit soil on the linen thereby reducing or eliminating graying of the goods. It is not necessary to centrifuge (and drain at a low speed) the free water before the final extract. With the present invention the process time is reduced. The amount of fresh water required compared with conventional processes is reduced.
[0019] The method of the present invention uses less water than in current art because the counter flow throughout the wash and rinse modules or zones is stopped for part of the cycle. The spray rinse in the centrifugal extractor or mechanical press is more effective than the current practice of draining the free water from the linen and then refilling.
[0020] The method of the present invention preserves the washing effectiveness of current counter flow washers to wash heavy soil classifications because the amount of soil dilution is the same even though there are less zones, stages, or modules. The present invention provides a higher effective rinsing provided by the spray rinse in the centrifugal extractor because of the pre-rinse in the tunnel washer.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0021] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0022] FIG. 1 is a schematic diagram showing the preferred embodiment of the apparatus of the present invention;
[0023] FIG. 2 is a schematic diagram showing the preferred embodiment of the apparatus of the present invention;
[0024] FIG. 3 is a schematic diagram showing the preferred embodiment of the apparatus of the present invention;
[0025] FIG. 4 is a schematic diagram of an alternate embodiment of the apparatus of the present invention;
[0026] FIG. 5 is a schematic diagram of the alternate embodiment of the apparatus of the present invention;
[0027] FIG. 6 is a partial perspective view of the alternate embodiment of the apparatus of the present invention;
[0028] FIG. 7 is a partial perspective view of the preferred embodiment of the apparatus of the present invention;
[0029] FIG. 8 is a fragmentary perspective view of the alternate embodiment of the apparatus of the present invention showing the starch dispensing nozzle tube;
[0030] FIG. 9 is a fragmentary perspective view of the alternate embodiment of the apparatus of the present invention showing the starch dispensing nozzle tube; and
[0031] FIG. 10 is a fragmentary perspective view of the alternate embodiment of the apparatus of the present invention showing the starch dispensing nozzle tube.
DETAILED DESCRIPTION OF THE INVENTION
[0032] FIGS. 1-3 show schematic diagrams of the textile washing apparatus of the present invention, designated generally by the numeral 10 . Textile washing apparatus 10 provides a tunnel washer 11 having an inlet end portion 12 and an outlet end portion 13 . Tunnel washer 11 provides a number of modules such as the modules 14 - 18 shown in FIG. 1 . These modules 14 - 18 can include a first module 14 and a second module 15 which can be pre-wash modules. The plurality of modules 14 - 18 can also include modules 16 , 17 and 18 which are main wash and pre-rinse modules.
[0033] The total number of modules 14 - 18 can be more or less than the five (5) shown in FIG. 1 . FIG. 2 shows an alternate arrangement that employs a tunnel washer 11 having eight (8) modules 14 - 18 and 35 - 37 . FIG. 3 shows an alternate arrangement that employs a tunnel washer 11 having ten (10) modules 14 - 18 and 35 - 39 . In FIG. 2 , the modules 14 , 15 can be pre-wash modules. In FIG. 3 , modules 14 , 15 , 16 can be pre-wash modules. In FIG. 2 , the modules 16 , 17 , 18 and 35 , 36 , 37 can be main wash and pre-rinse modules. In FIG. 3 , the modules 17 , 18 and 35 , 36 , 37 , 38 , 39 can be main wash and pre-rinse modules. Instead of a two (2) or three (3) module pre-wash section (see FIGS. 1 , 2 , 3 ), a single module 14 could be provided as an alternate option for the pre-wash section.
[0034] Inlet end portion 12 can provide a hopper 19 that enables the intake of textiles or fabric articles to be washed. Such fabric articles, textiles, goods to be washed can include clothing, linens, towels, and the like. An extractor 20 is positioned next to the outlet end portion 13 of tunnel washer 11 . Flow lines 21 , 25 , 26 , 27 , 27 A are provided for adding water and/or chemicals to tunnel washer 11 at selected or desired locations.
[0035] When the fabric articles, goods, linens are initially transferred into the main wash modules 16 , 17 , 18 , a counter flow of wash liquor into these modules 16 , 17 , 18 is stopped allowing for a standing bath. In FIG. 1 , chemicals are then added as indicated by arrows 26 , 27 and 27 A to the modules 16 , 17 and/or 18 . In FIG. 2 , chemicals are added as indicated by arrows 26 , 27 , 27 A to the modules 16 , 17 , 18 , 35 , 36 and/or 37 . In FIG. 3 , chemicals are added to the modules 16 - 18 and 35 - 39 as indicated by the arrows 26 , 27 , 27 A. In each arrangement of FIGS. 1-3 , these chemicals separate the soil from the goods, linens or textiles and suspend the soil in the wash liquor. During this step of the method of the present invention, the wash liquor temperature can be elevated if needed to facilitate the release of soil from the goods, fabric articles or linens and activate the chemicals.
[0036] Once the maximum soil has been released from the textiles or fabric articles in each module, there is no more work for those chemicals to perform. At this time, the process can be described as chemical equilibrium. The flow of water is stopped for a time period sufficient to release soil from the goods such as for example between about twenty (20) seconds and one hundred twenty (120) seconds. However, this time interval can be between about ten (10) and three hundred (300) seconds.
[0037] After this time interval of having no counter flow, water by counter flow is commenced to remove the suspended soil. If more wash chemicals are to be added, then this counter flow can be termed intermediate rinse. Once the goods reach the module or zone where no more wash chemicals are added, then the counter flow can be termed pre-rinse. A final rinse is then performed in a centrifugal extractor or mechanical press 20 . The process of the present invention uses fresh water in the extractor that can be supplied via flow line 29 through an atomizing nozzle, for example while the goods are being extracted at high speed (e.g. between about 200 and 1,000 g's) using the extractor 20 .
[0038] Flow line 21 transmits water to hopper 19 as indicated by arrow 22 . Flow line 21 also carries water to pre-wash module 15 as indicated by arrow 23 . Arrow 24 indicates a flow of water from module 14 to module 15 as part of the pre-wash.
[0039] In FIG. 1 , flow line 25 adds water for counter flow pre-rinse to module 18 . Such water added via flow line 25 to module 18 flows in counter flow fashion from module 18 to module 17 to module 16 (see arrow 25 A). Arrows 26 and indicate chemical addition to modules 16 and 17 respectively. Chemicals to be added to modules 16 and 17 and can include detergent, alkali and/or oxidizing agents as examples.
[0040] In FIG. 2 , flow line 25 adds water for counter flow pre-rinse to module 37 . Such water added via flow line 25 to module 37 flows in counter flow fashion from module 37 to module 36 , then 35 , then 18 , then to module 17 (see arrow 25 B in FIG. 2 ).
[0041] In FIG. 3 , flow line 25 adds water for counter flow pre-rinse to module 38 . Such water added via flow line 25 to module 38 flows in counter flow fashion from module 38 to module 37 , module 36 , module 35 , module 18 , and module (see arrow 25 C).
[0042] In FIG. 1 , textiles or fabric articles that are pre-washed, washed, and then pre-rinsed in tunnel washer 11 are transferred from module 18 to extractor 20 as indicated schematically by arrow 28 . In FIG. 2 , the textiles or fabric articles that are pre-washed, washed, and then pre-rinsed in tunnel washer 11 are transferred from module 37 to extractor 20 as indicated schematically by arrow 28 . In FIG. 3 , textiles or fabric articles that are pre-washed, washed, and then pre-rinsed in tunnel washer 11 are transferred from module 39 to extractor 20 as indicated schematically by arrow 28 .
[0043] The method of the present invention thus conducts rinsing in two zones. Rinsing is first conducted in the tunnel washer 11 in a pre-rinse zone which occurs after the main wash. In FIG. 1 , pre-wash zones can be 14 , 15 . The pre-rinse zone and main wash zone can be modules 16 , 17 , 18 . In FIG. 2 , the pre-wash zone can be modules 14 and 15 while the main wash and pre-rinse zones can be modules 16 , 17 , 18 , 35 , 36 and 37 . In FIG. 3 , the pre-wash zone can be modules 14 , 15 and 16 while the main wash and pre-rinse zones can be modules 17 , 18 , 35 , 36 , 37 , 38 and 39 . The second rinse zone is the final rinse, which is conducted in the extractor 20 or other mechanical water removal machine such as a mechanical press.
[0044] Because the free soil has already been removed in the pre-rinse zone at modules 16 , 17 , 18 of FIGS. 1 (or 16 - 18 , 35 - 37 of FIGS. 2 or 16 - 18 , 35 - 39 of FIG. 3 ) as part of the method of the present invention, the spray rinse while extracting at high speed (between about 200-1,000 g's) will not redeposit soil on the linen thereby reducing or eliminating graying of the goods. With the present invention it is not necessary to centrifuge (and drain at a low speed) the free water before the final extract at 20 . With the present invention, the process time is thus reduced. The amount of fresh water required compared with conventional processes is reduced. The spray rinse and the centrifugal extractor 20 or mechanical press is more effective than the current practice of draining the free water from the linen and then refilling the extractor 20 .
[0045] An additional benefit of the pre-rinse concept of the present invention is to permit the mechanical press or extractor to have more time extracting the free water. This result follows because the effect of the pre-rinse is to remove most of the suspended soil. The amount of fresh water required for final rinse is thus greatly reduced. The time for rinsing is reduced, allowing this saved cycle time for water removal.
[0046] The method of the present invention preserves the washing effectiveness of current counter flow washers 11 to wash heavy soil classifications because the amount of soil dilution is the same even though there are fewer zones or stages or modules.
[0047] The present invention provides a higher effective rinsing provided by the spray rinse (arrow 30 ). Water is supplied by tank 43 . Spray water flows via flow line 29 and is sprayed via a nozzle at 30 into the centrifugal extractor 20 . A higher effective rinsing is provided because of the intermediate and pre-rinse that is conducted in the modules 16 , 17 , 18 as discussed above in FIG. 1 , and the additional modules as discussed above for FIGS. 2 and 3 .
[0048] Outlet valves 33 can be provided on each module 14 - 18 , 35 - 39 for each FIGS. 1 , 2 , 3 enabling any of the modules 14 - 18 or 35 - 39 to be drained as indicated by arrows 34 . Extracted water 31 can be added to water flow line 21 . Extracted water 31 can be supplemented with fresh water via flow line 32 .
[0049] FIGS. 4-10 show an alternate embodiment of the apparatus of the present invention, designated generally by the numeral 40 . The textile washing apparatus 40 of the alternate embodiment can provide the same tunnel washer 11 of the preferred embodiment having the modules 14 - 18 , 35 - 39 provided in any one of the embodiments of FIG. 1 , 2 or 3 . FIG. 4 shows the embodiment of FIG. 1 having a specially configured starch spray arrangement.
[0050] In FIG. 4 , a starch tank 41 contains starch that is to be injected into the linen, fabric articles, or clothing contained in extractor 20 . Starch for the table linen, clothing, fabric articles is pumped in the first phase of the cycle through a spray nozzle 60 (see FIGS. 8-10 ). Controlled flow metering can be achieved for example using an inverter controlled flow metering device. The precise amount of starch is thus injected into the linen, fabric articles, clothing or the like while in extractor 20 . Excess starch can be removed in a separate tank indicated as starch recovery tank 52 in FIG. 4 . Flow line 53 enables recovered starch in tank 52 to be transferred to starch tank 41 .
[0051] Starch tank 41 contains starch that is to be pumped via flow line 42 to nozzle 60 and then to extractor 20 . Fresh water tank 43 can also be used to pipe fresh water to extractor 20 , flowing through valve 45 to nozzle 60 . Valves 44 , 45 and 46 are provided for controlling the flow of either starch or fresh water or a combination thereof to nozzle 60 as shown in FIG. 4 .
[0052] Flow line 49 is a flow line that carries extracted water to tank 51 as it is purged from the fabric articles, clothing or linens contained in extractor 20 . Starch can be recovered via flow lines 49 , 50 to starch recovery tank 52 . Valves 44 , 47 are provided for valving the flow of starch from tank 41 to extractor 20 via flow line 42 . Valve 48 enables tank 41 to be emptied for cleaning or adding new starch.
[0053] In FIGS. 8-10 , starch spray nozzle 60 is shown in more detail. The spray nozzle 60 can provide an elongated section of conduit or pipe 61 . Spray nozzle 60 has an influent end 62 and a discharge end portion 63 . Conduit 61 provides an open ended bore 64 for conveying starch from flow line 42 to nozzle 60 . Influent end 62 provides a connection 80 for attaching conduit 61 to flow line 42 .
[0054] FIGS. 5-7 illustrate the spray pattern 76 that strikes the wall of drum 57 of extractor 20 as emitted by nozzle 60 . In FIGS. 6 and 7 , extractor 20 provides a drum 57 that provides a chamber 55 having an inlet 56 . Clothes, textiles, linens to be sprayed are discharged from tunnel washer 11 via chute 79 into the chamber 55 of extractor 20 . The extractor 20 is preferably movable between a loading and discharging position. The loading position is shown in FIGS. 5 and 6 . In the loading position, clothes transfer from the tunnel washer 11 to the chamber 55 via chute 79 . Pumps 54 can be used to aid in the transfer of water from tank 43 or starch from tank 41 into chamber 55 via nozzle 60 . The spray nozzle 60 produces a spray pattern 76 that extends substantially across the cylindrical wall 58 of drum 57 as shown in FIGS. 6 and 7 . Drum 57 thus provides an inlet 56 for enabling clothing, textiles, or other fabric articles to be added to the drum 57 interior 55 and a rear circular wall 59 . Notice in FIGS. 6 and 7 that the spray pattern 76 extends generally from inlet 56 to circular wall 59 , thus extending substantially across cylindric wall 58 as shown in FIGS. 6 and 7 . Arrow 77 in FIG. 7 illustrates the width of spray pattern 76 which can be about 16 degrees as an example along cylindrical drum wall 58 .
[0055] A mounting plate 65 can be provided having one or more openings 66 for attaching (for example, bolting) spray nozzle 60 to extractor 20 or to a frame that supports extractor 20 .
[0056] The discharge end portion 63 of spray nozzle 60 provides a nozzle tip 67 . The nozzle tip 67 provides a nozzle outlet 70 formed by side plates 71 , 72 , upper plate 73 and lower plate 74 . Atomizing water nozzle 68 , 69 are provided next to nozzle outlet 70 . The atomizing water nozzle 68 is mounted to upper plate 73 . The atomizing water nozzle 69 is mounted to lower plate 74 as shown in FIGS. 8-10 . Spray nozzle 60 can be equipped with aerating or atomizing nozzles 68 , 69 to control the consistency of the starch in the nozzle 60 , thus preventing starch build-up which might eventually plug of the nozzle 60 .
[0057] As part of the method of the present invention, all starch flow lines 42 , 60 can be purged with hot water from fresh water tank via flow line 75 .
[0058] The following is a list of parts and materials suitable for use in the present invention.
[0000]
PARTS LIST
Part
Number
Description
10
textile washing apparatus
11
tunnel washer
12
inlet end portion
13
outlet end portion
14
module
15
module
16
module
17
module
18
module
19
hopper
20
extractor
21
flow line
22
arrow
23
arrow
24
arrow
25
flow line
25A
arrow
25B
arrow
25C
arrow
26
arrow - chemical addition
27
arrow - chemical addition
27A
arrow - chemical addition
28
arrow - textile transfer
29
spray rinse flow line
30
arrow
31
extracted water
32
flow line
33
outlet valve
34
arrow
35
module
36
module
37
module
38
module
39
module
40
textile washing apparatus
41
starch tank
42
flow line
43
fresh water tank
44
valve
45
valve
46
valve
47
valve
48
valve
49
flow line
50
flow line
51
extracted water tank
52
starch recovery tank
53
flow line
54
pump
55
chamber
56
inlet
57
drum
58
cylindrical drum wall
59
circular drum wall
60
spray nozzle
61
conduit
62
influent end
63
discharge end
64
bore
65
mounting plate
66
opening
67
nozzle tip
68
atomizing water nozzle
69
atomizing water nozzle
70
nozzle outlet
71
side plate
72
side plate
73
upper plate
74
lower plate
75
flow line
76
spray pattern
77
arrow
78
drum moving mechanism
79
chute
80
connection
[0059] All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
[0060] The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A method of washing fabric articles in a tunnel washer includes moving the fabric articles from the intake of the washer to the discharge of the washer through first and second sectors that are a pre-wash zone. In the pre-wash zone, liquid is counter flowed in the wash interior along a flow path that is generally opposite the direction of travel of the fabric articles. The fabric articles are transferred to a main wash zone, and a washing chemical is added to the main wash zone. At about the same time, counter flow is reduced or stopped. The main wash zone can be heated as an option. After a period of time (for example, between about 20 and 120 seconds) counter flow is increased. The increased counter flow after chemical treatment amounts to either an intermediate rinse or a pre-rinse depending upon which module or zone the goods occupy. The pre-rinse ensures that the fabric articles are substantially free of soil or the majority of any soil when they are transferred to an extractor for final removal of excess water. | 3 |
BACKGROUND OF THE INVENTION
Conventional high-leg reclining chairs have exposed legs 7"-8"long and high wing backs. They are either two-way or three-way operation activated by pushing on the arms for TV and full-recline positions. They are produced in two sizes, three-way mechanisms in the larger chairs and two-way mechanisms in the smaller chairs. The difference in the sizes of the two types of chairs is approximately three inches, measured from the front of the arm to the rear of the arm. The length of the arm is important to the three-way mechanism due to the movement of the center of gravity of the chair plus occupant from upright to full recline. This can cause the chair to tip backward if the arm is too short.
Also, conventional two-way and three-way high-leg recliner chair mechanisms conventionally require different frames and the mechanisms have few common parts. This becomes important when tooling new mechanisms and inventorying components for mechanisms or frames. Other complaints with existing mechanisms include linkages visible under the chair, ottomans drooping, and backs loose in the upright position.
The terms "two-way" and "three-way" are not to be confused with the term "three-position".
A three-position recliner is one which has a fully-erect, upright position in which the back is erect and the leg-rest is fully stowed, an intermediate (or "TV") position in which the back remains erect, or nearly so, but the leg-rest is at least partly raised and extended, and a reclining position, in which the back is tilted backwards and down, and the leg-rest is fully extended and raised.
A three-position chair can have either two-way or three-way operation. If the chair has two-way operation, usually the seat is fixed in relation to the back, so that the angle between them remains the same during tilting and erecting. However, if the chair has three-way operation, as the chair moves from the TV position to the fully-reclined position, the upper end of the chair back tilts down and backwards relative to the seat, and back up as the chair moves from the fully-reclined position to the TV position. Generally in a chair having two-way operation, framing components unite the chair back and seat into a common structure.
SUMMARY OF THE INVENTION
A pair of side mechanisms mount a back, seat and ottoman on a high-leg chair frame. Although the mechanisms are short, and require less longitudinal travel in operation, they can be used not only for chairs with two-way operation but also three-way operation. The mechanism does not protrude under the seat in use, so the frame legs may be as tall as the aesthetic design requires. The back is secure in the upright position. The sequence link of each mechanism operates on the rear pivot link of the mechanism. The ottoman linkage, including a spring, locks the ottoman in the upright position, although the lock can be overcome by the user pushing forward on the arms of the chair.
The principles of the invention will be further discussed with reference to the drawings wherein a preferred embodiment is shown. The specifics illustrated in the drawings are intended to exemplify, rather than limit, aspects of the invention as defined in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings
FIG. 1 a perspective view of a high-leg recliner chair in its fully-erect position;
FIG. 2 is a side elevation view of one side mechanism, particularly showing the inboard side of a right side mechanism in its fully-erect position and adapted for three-way operation;
FIG. 3 is a side elevation view of the mechanism of FIG. 2 in its TV position; and
FIG. 4 a side elevation view of the mechanism of FIGS. 2 and 3 in its fully-reclined position.
FIG. 5 is a side elevation view of the chair of FIG. 1, with its mechanisms in the three-way fully-reclined position shown in FIG. 4.
FIG. 6 is a side elevation view of the same mechanism as shown in FIGS. 2-4, but adapted for two-way operation (by alternative mounting of one pivot pin), and shown in its fully-reclined position; and
FIG. 7 is a side elevation view of the chair of FIG. 1, with its mechanisms in the two-way fully-reclined position shown in FIG. 6.
DETAILED DESCRIPTION
A high-leg reclining chair is shown at 10 in a perspective view in FIG. 1.
Although the mechanism of the invention could be used in a short-leg recliner chair, the reverse is generally not true. That is, the mechanisms conventionally used in short-leg recliner chairs cannot usually be used on high-leg recliner chairs, because so much of the conventional mechanism for a conventional short-leg recliner chair protrudes under the seat and therefore would be obtrusively visible were the chair seat located far enough up off the floor that a person could see the region under the seat.
Although it is difficult to draw a distinct definitional line between a short-leg recliner chair and a high-leg recliner chair, a good working definition is that a high-leg recliner has at least five inches of leg protruding downwards to the floor from the lower edge of the ottoman when the chair is fully erect, and an overall style that permits a five foot six inch tall person to see the floor under the center of the chair when the chair is fully erect and the person is standing across the room, e.g. at a distance of fifteen feet from the chair. Often, although not essentially, a high-leg recliner has exposed wood legs, often including longitudinal (i.e., front to back) and/or transverse horizontal rungs interconnecting vertically intermediate sites on the legs and/or one another. Also, often, although not essentially, a high-leg recliner has no depending skirt around the lower margin of the upholstered frame.
For convenience in description in referring to the chair and mechanisms, the term "inboard" refers to towards the longitudinal median of the chair; "outboard" refers to the laterally, transversally outwards direction away from the longitudinal median. The terms "right" and "left" are used assuming the perspective of an occupant of the chair.
Although the chair 10 shown in FIG. 1 incorporates two of the mechanisms 12 (shown in FIGS. 2-5) or two of the mechanisms 12' (shown in FIGS. 6 and 7), these mechanisms are hidden by upholstery and other chair structure in FIG. 1. The chair 10 is shown in its fully-erect position in FIG. 1. In this position, the chair back is up, and the ottoman is stowed. The chair 10 in its fully-erect position bears a close resemblance to a non-reclining high-leg upholstered chair, in this instance to a wing back, upholstered library chair of an updated yet traditional style.
The chair 10 includes an upholstered base frame 14 which includes left and right generally vertical sides 16 topped by generally horizontal, longitudinally extending arms, 18 (in this instance upholstered, rolled arms), a set of depending legs 20 for supporting the chair on a floor and various transversally extending components (not all of which are shown, but which are represented by the transverse rung 22) which connect the left and right sides of the frame and provide structural and aesthetic integrity for the chair base.
The chair base frame 14 is shown being upholstered, as are the other components (apart from the mechanisms 12, which will be described below). Conventional upholstery 23 of cloth and/or leather may be used, as may be synthetic sheets and composites such as "vinyl" upholstery. The mechanisms of the invention impose no particular limitations on the materials that the chair can be made of, as it is believed a person of ordinary skill in the art will readily understand. Preferred materials used for manufacturing the chair (apart from the mechanisms) include particle board, wood, mechanical fasteners, adhesive, batting, foamed plastic, chair springs, non-woven fiber, cloth and miscellaneous hardware. The mechanisms are preferably predominately made of links cut and bent from steel plate and painted matte black, these being interpivoted, connected and stopped by steel pins and rivets, with bushings of lubricous plastic sheet material interposed between members of joints. Springs are made of spring steel.
The mechanisms 12 have as one function securing various main parts of the chair together as an operative unit.
The main parts include, in addition to the upholstered base frame 14, a seat 24, a back 26 and an ottoman 28 (which some people would call a leg-rest or a foot-rest). It is conventional for recliner chairs to have two-part ottomans, i.e. a primary ottoman 28 (the one that shows in FIG. 1) and a secondary ottoman which, in the fully-erect position of the chair may be hidden under, in back of and/or behind the primary ottoman. The chair shown in FIG. 1 preferably has a secondary ottoman, and, as can be deduced from FIGS. 2-4, in the fully-erect position of the chair, it is substantially hidden from sight in a downwards-facing orientation closely under the seat about eight inches behind the back of the primary ottoman.
The chair back need not have wings 30, but wings on such chairs are a popular feature. In some high-leg recliners, the seat comprises an underlying support attached to the side mechanisms and surmounted by a loose cushion. In other instances, the support structure and cushion are built into a unitary assembly which is mounted as a whole to the side mechanisms.
In the chair 10 provided with the mechanisms of the present invention, there is preferably no hand crank or motor for operating the chair. Rather, the fully-erect chair is operated by an occupant by pushing forwards on the arms relative to the seat to extend the ottoman and move the seat somewhat forwards relative to the base to achieve the TV position. In instances where the chair 10 is a three-position chair, full recline is achieved from the TV position, by the occupant by pushing back with his or her shoulders on the upper part of the chair back, causing the chair back to tilt down relative to the base (and also lowering the seat relative to the base), thereby lowering the chair/occupant composite center of gravity as reclining of the back shifts the composite center of gravity rearwardly, thereby preserving tolerable stability, despite the fact that the chair is a high-leg chair.
The mechanisms 12 as adapted for three-way operation will be described in detail with reference to FIGS. 1-5. Then the differences of the mechanisms 12' as adapted for two-way operation will be described with reference to FIGS. 1, 6 and 7.
The mechanism 12 shown in FIGS. 2-4 is a right side mechanism. The chair 10 is provided with both a left side mechanism and a right side mechanism, one being a mirror image of the other, each being comparably mounted to the chair parts and the two coacting as the chair is operated.
The mechanism 12 includes a long, upper longitudinal link 32, which, like all the links to be described is preferably stamped, bent and punched or drilled from metal plate. The links are preferably planar, except that many of them have one or more shallow-S double bends in them, where necessary to prevent them from interfering with position or intended loci of movement of one another. Thus, for instance, the forward end portion of the link 32 jogs inboard by one thickness at 34 and the rear portion thereof jogs inboard by three thicknesses at 36, both compared with the central portion of the long link 32. The rear portion of the link 32 is shaped as an upwardly projecting spur 38.
The central portion of the long link 32 is shown provided with a series of holes 40 to receive fasteners for fastening the mechanism to a respective side of the seat 24 of the chair.
The mechanism 12 further includes a base-mounting bracket 42 which is provided by a link folded along a longitudinal axis so as to have an outboard vertically-oriented, longitudinally-extending flange 44 which extends throughout approximately the rear eighty percent of the bracket 42, and a generally horizontally, inboard-extending flange 46 at the lower extent of the flange 44, which extends throughout approximately the foremost two-thirds of the bracket 42. The flange 46 is provided with a series of holes 48 to receive fasteners for fastening a respective side 16 of the base frame 14 to the mechanism 12. The flange 44 is located inboard of the central portion of the long frame-mounting link 32 by about seven link thicknesses.
The feature indicated on the flange 44 is not a slot; rather it is an outboard-facing groove embossed in the link, which causes a corresponding low ridge extending along the inboard face of the flange 44, the purpose of such embossment being to impart improved anti-bending strength to this link. (Other links are shown having similar embossments, as will be briefly pointed out as the respective links are introduced in the description below.)
The link shown located furthest outboard on the mechanism 12 is the flat, V-shaped back-mounting link 50, located on the outboard side of the spur 38 of the seat-mounting link 32. The link 50 is shown provided through the thickness thereof with a series of vertically spaced holes 52 for receiving fasteners for securing the link to a respective edge of the chair back 26.
At its forward end (when in the closed position shown in FIG. 2, equating to the fully erect position of the chair), the mechanism 12 has a primary ottoman mounting bracket 54 in the form of a link folded along a line which is substantially vertical when the mechanism is in its closed position, so as to have a rearwardly-projecting longitudinal flange 56 and, at its forward margin, an inboard-projecting flange 58 provided with a series of vertically spaced openings 60 for mounting a corresponding end of the primary ottoman 28 thereto.
By preference, the chair 10 further includes a secondary ottoman (not shown in FIG. 1, but described above), and, for mounting it, the mechanism preferably includes a secondary ottoman mounting bracket 62. This bracket is shown comprising another link folded along a longitudinal fold line so as to have an elongated, vertical-plane flange 64 and, along its rear third, an inboard-extending flange 66. The latter is provided with a series of holes 68 for mounting a corresponding end of a secondary ottoman thereto. The flange 64 has a jog from about ten percent of the way back, to about half-way back from its front end, which places its rear portion in a plane about seven link-material thicknesses inboard of its front portion.
The links and brackets by which the mechanisms 12 unite the chair into a unitary structure carried on the chair base have all been introduced above; the remainder of the description relates how the links and brackets of a mechanism 12 are interconnected and how they interact in use. Unless the contrary appears, all of the rivets, pivot joints and pins described below have transverse horizontally-extending main axes (i.e., their own longitudinal axes extend crosswise of the chair and are horizontal). Even if not specifically mentioned, any of the pivot joints can include washer-like bushings, e.g. made of a lubricous synthetic plastic material such as nylon, between the interpivoted parts and/or between the pivot pin head and/or upset tail and the respective adjacent part. And any stop pin or mounting pin may be a plain metal pin, or, where cushioning or noise-reduction is a consideration, a metal pin sleeved with a tubular bushing of lubricous synthetic plastic material such as nylon.
A multiple-link lazy tongs-type linkage 70 is provided at the front end of the seat-mounting link 32 for mounting the primary and secondary ottoman-mounting brackets 54 and 62.
The linkage 70 is shown comprising upper and lower forward links 72, 74 and upper and lower rear links 76, 78.
The front ends of the upper and lower forward links 72, 74 are connected one above the other (in the closed position of the mechanism) to the longitudinal flange of the primary ottoman mounting bracket by respective pivot joints 80, 82.
The rear ends of the upper and lower rear links 76, 78 are connected one in front of and above the other to the forward portion of the seat-mounting link 32 by respective pivot joints 84, 86.
A pivot joint 88 is provided where the upper forward link crosses the upper rear link, located approximately eighty percent down from the upper ends of these links. The lower end of the lower front link is connected to the lower end of the upper rear link by a pivot joint 90, and the lower end of the upper front link is connected to the lower end of the lower rear link by a pivot joint 92. In the preferred embodiment, the upper rear link is flat, the central approximately eighty percent of the lower front link is jogged outboards by about two link thicknesses, and the upper approximately twenty percent of the upper and lower rear links are jogged outboards by about three link thicknesses.
An inboard-extending pin 94 provided on the upper rear link about one-third back from its front end is available to engage the upper edge of the upper front link at 96 and 98 to provide respective stops limiting retraction and extension of the lazy tongs linkage as the primary ottoman is stowed and deployed.
Below where the front end of the lower front link mounts to the longitudinal flange of the primary ottoman-mounting bracket, a pivot joint 100 connects the heel of the foot of the longitudinal flange of the secondary ottoman-mounting bracket to the primary ottoman-mounting bracket.
A secondary ottoman operator link 102 is provided having one end connected by a pivot joint 104 to the toe of the foot of the longitudinal flange of the secondary ottoman-mounting bracket (at a location that is spaced generally directly vertically below the pivot joint 100 by about an inch and a half when the mechanism 12 is in its fully closed position). The opposite end of the operator link 102 is connected by a pivot joint 106 to the upper front link about twenty percent back from the front end of the upper front link. Accordingly, as the primary ottoman 28 is extended from its stowed, on edge, location under the front lip of the seat 24, the operator link 102 swings the secondary ottoman-mounting bracket through almost one hundred eighty degrees, from being located occupant's leg support-face down, up under the seat behind the primary ottoman, to right-side-up, and in a common, slightly tilted forwards plane with the primary ottoman, out front of the primary ottoman, e.g. by about three inches.
The feature 108 is a stiffening ridge impressed in the link 102.
An inboard-extending pin 110 provided on the upper front link below and to the rear of the pivot joint 106, about an inch away from the pivot joint 106, in a position to act as a secondary stop limiting travel of the secondary ottoman upon retraction, by engagement with an edge of the secondary ottoman operator link 102.
The seat-mounting link 32 is shown provided with front and rear depending links 112, 113 respectively connected at their upper ends to the central portion of the link 32 about one-third back from the front end of the link 32 by a pivot joint 116, and to the base of the spur 38 near the rear end of the link 32 by a pivot joint 118.
The front depending link 112 is generally L-shaped, with a depending stem and a lower leg 114 projecting forwards. The lower sixty percent of the link 112 is jogged inboards about four link thicknesses compared to the upper twenty percent thereof. The forward end of the lower leg 114 of the link 112 includes an angled downwards toe (located in the same plane as all of the leg 114), on which is provided a pivot joint 116.
An ottoman lazy tongs operator link 118 has a rear, lower end connected to the toe of the front depending link 112 by the pivot joint 116, and a front, upper end connected to a site on the lower rear link of the lazy tongs about forty percent of the way down from the upper end of that link, by a pivot joint 120.
Accordingly, when the front depending link swings forwards about its upper end, the operator link 118 has its rear, lower end pushed towards the pivot joints by which the upper and lower rear links are connected to the base-mounting link 32, thereby extending the lazy tongs and thrusting the ottoman. The reverse happens as the front depending link swings rearwards about its upper end.
The back-mounting link 50 is a generally V-shaped link the rear leg of which is shown being somewhat less tall than the forward leg thereof. One of the holes for mounting the back is shown provided at the upper end of the forward leg, and the other is shown provided about forty percent up the rear leg from the lower end. The back-mounting link is shown connected near its lower end, in the region where its legs join, to the spur 38 of the seat-mounting link 32, near the upper end of the spur 38, by a pivot joint 122.
About three-quarters of an inch about the joint 122, the link 50 is provided with an inboard-projecting pin 124 which is available to engage the rear edge of the spur 38 above the joint 122 as the chair is erected for defining the location of the back in the fully-erect position of the chair and helping to maintain the back tightly in place in the closed position of the mechanism.
The mechanism 12 further includes an operator link 126 for the back-mounting link. The operator link 126 has an upper end connected to the upper end of the rear leg of the back-mounting link 50 by a pivot joint 128, and a lower end connected to the rear end of the vertical, longitudinal flange of the base-mounting bracket 42 by a pivot joint 130. Accordingly, when the base-mounting bracket 42 translates forwards relative to the seat-mounting link 32, and the latter tips upwards to the front slightly as the mechanism opens from the fully closed (FIG. 2) to the TV position (FIG. 3), the operator link 126 mainly merely pivots forwards around its upper end, but also is pulled slightly downwards in a translational sense, so that the back-mounting link 50 tilts slightly to the rear, thus slightly tilting the back of the chair.
The upper ten percent of the operator link 126 is jogged about five link-thicknesses outboards relative to the lowest two-thirds of that link. 128 indicates an impressed stiffening ridge.
If the chair 10 is provided to have a third, fully-reclined position (FIG. 3), in achieving this position from the TV position (by means hereinafter more fully described), the front of the seat-mounting bracket raises about one and a quarter inches, and the rear of the seat-mounting bracket raises about one half of an inch and the seat mounting bracket swings rearwards about one-quarter of an inch. This action, in combination, pulls downwards and forwards on the back-mounting link operating link 126, causing the latter to rotate rearwardly about its connection to the spur 38 by about fifteen degrees, thereby reclining the chair back.
The remaining structure of the mechanism 12 mounts the base-mounting bracket to the seat-mounting link 32 and operates the base-mounting bracket 42 in relation to the seat-mounting link, also causing operation of ottoman and chair back as has been described above. The remaining structure of the mechanism 12 is the most difficult to visualize because it is, in general, sandwiched between the longitudinal flange of the base-mounting bracket 42 and the seat-mounting link 42.
The upper end of the rear depending link 113 is shown provided with a rearwardly-extending prong 130. The base link 32 is shown provided at the base of the spur 38, behind and below the pivot joint connecting the upper end of the rear depending link 113 to the seat-mounting link 32, with an inboards-extending pin 132. The pin 132 engages the lower edge of the prong 130 to limit forwards swinging of the rear depending link (and therefore the front depending link 112 and the seat-mounting bracket) relative to the seat-mounting link 32, as the mechanism 12 opens from the closed to the TV position thereof.
A longitudinally short control link 134 is connected by its upper, rear end to the vertical longitudinal flange of the base-mounting bracket 42 about twenty-five percent forwards from the rear end of the base-mounting bracket 42 and about one-fourth of an inch below the inboards-extending flange of the base-mounting bracket 42, by a pivot joint 136. The link 134 is about two inches long. Its forward, lower inch is jogged outboards relative to its rear, upper inch by about three link thicknesses. That outer portion is provided with a slot 138, elongated along the length of the link 134, and a sliding, pivotal connection is made between such portion and the lower end of the rear depending link 113 by a pivot joint 140 which can slide along the slot 138.
When the mechanism 12 is closed, the link 134 projects downwards and slightly forwards and the pivot joint 140 is located at the upper end of the slot 138. As the mechanism opens from the closed position (FIG. 2) to the TV position (FIG. 3), the link 134 pivots forwards about fifty degrees about its upper end as the pivot joint 140 slides to bottom of the slot 138. As the mechanism moves from the TV position to the fully-reclined position, the link rotates approximately seventy degrees further in the same direction (so that the control link projects upwards and forwards at about a forty-five degree angle) and the pivot joint 140 slides back to the same end of the slot it occupied in the closed (FIG. 2) position. (Because the control link has rotated so much between its FIG. 2 and FIG. 4 positions that it has become generally inverted, the lower end of the slot 138 in FIG. 2 will be called its outer end, and the upper end of the slot 138 in FIG. 2 will be called its inner end, both relative to the pivot joint 136.)
The mechanism 12 further includes three boomerang (or arcuate)-shaped links, namely a forward long one 142, which is concave upwards, a rear long one 144, which is concave downwards, and, under the rear half of the rear long arcuate link, a rear short arcuate link 146, which is concave upwards.
The forward upwardly-concave arcuate link 142 is connected in its central elbow region to the vertical longitudinal flange of the base-mounting bracket 42 near the fold line of the base-mounting bracket, about one-third of the way back from the front end of the base-mounting bracket, by a pivot joint 148. The front end portion (about three-quarters of an inch) of the link 142 is jogged outboards by about two link thicknesses, and about the same amount of the rear end portion is jogged outboards by about one link thickness.
The front end of the link 146 is connected to the base of the upright standard of the front depending link 112 by a pivot joint 150.
In the closed position (and in the TV position), an inboards-projecting pin 152 provided on the front arm of the link 142 about two-thirds of the way forwards along that arm from the pivot joint 148, engages on a recessed upper edge region of the vertical longitudinal flange of the seat-mounting bracket.
In the fully-reclined position (FIGS. 4 and 5), an upper edge portion of the link 142, forwardly of the pivot joint 148, engages an outboards-extending pin provided on the vertical, longitudinal flange of the base-mounting bracket for limiting tilting-down of the back and raising of the seat, both relative to the base-mounting link 32.
The rear upwardly-concave link 146 is connected at its central bend to the vertical, longitudinal flange of the base-mounting bracket at the rear end of the latter, below the connection of the lower end of the back-operating link to that flange, by a pivot joint 154.
The forward end of the rear upwardly-concave link 146 is connected to the rear depending link about forty percent of the way up from the lower end of the latter, by a pivot joint 156.
The link 146 remains immobile as the mechanism moves between its fully closed (FIG. 2) and TV (FIG. 3) positions, with an outboards-projecting pin 158 on the vertical, longitudinal flange of the base-mounting bracket 42 engaging the lower edge of the link 146 approximately midway between the pivot joints 148 and 156.
The mechanism 12 is shown provided with aligned openings 160, 162 through the vertical, longitudinal flange of the base-mounting bracket 42 above the pin 158 and through the link 146. For restricting the chair 10 to having only a fully-erect and a TV position, a rivet 164 can be installed through the aligned openings 160, 162, as well.
The rear, concave-downwards link 144 has its rear end connected to the rear end of the link 146 by a pivot joint 166 and its front end connected to the rear end of the forward concave-upwards link 142 by a pivot joint 166. The links 142, 144 and 146 remain immobile as the mechanism moves between its closed (FIG. 2) and TV (FIG. 3) positions.
As the mechanism moves from the TV position (FIG. 3) to the fully-reclined position (FIG. 4), the forward, upwardly-arcuate link rocks towards the rear about its central pivot joint, thus raising the front of the seat-mounting link 32 relative to the base-mounting bracket 42, shifting the rear, downwardly-concave link 144 rearwards, thereby raising the rear of the seat-mounting link 32.
The raising of the rear of the seat-mounting link pulls down the lower end of the back-operating link, thereby fully reclining the chair back.
When the mechanism is in its TV position (FIG. 3), the ottoman can be retracted by the occupant by pulling backwards with his or her heels on the front edge of the primary ottoman, while pushing forwards on the arms of the chair. However, when the chair is in its fully-reclined position, the pivotal connection of the front end of the rear upwardly-concave link to the intermediate location on the rear depending link forces the pivot joint at the lower end of the rear depending link along the slot in which it is mounted, to the inner end of that slot, and the angular orientation of the link in which the slot is provided then prevents the rear depending link from swinging about its upper end pivot joint, thus preventing the ottoman from being retracted. In other words, the ottoman-mounting lazy tongs is locked in an extended condition so long as the chair back is fully reclined.
In the preferred embodiment, the seat-mounting link is about sixteen inches long (as projected onto a horizontal, longitudinally-extending line, i.e., not adding five more inches for the distance up the spur 38, but only the about two inches that the spur projects rearwards of its own base on the link 32).
Erecting the chair from a reclined position, to a TV position, and to a fully-erect position involves a reversal of the steps explained above. The weight of the person, concentrating on the seat, pushes the seat down, pulling up the back, whereupon ottoman retraction is assisted by the person's heels.
The tension coil spring 168 mounted between pins provided on the seat-mounting link 32 ahead of the pivot joint 116 and an intermediate location on the ottoman lazy tongs operator link 118 acts as the ottoman is retracted to keep the primary ottoman firmly retracted in its stowed position, shown in FIG. 1.
The mechanism 12' shown in FIGS. 6 and 12 is exactly like the mechanism 12 as described in relation to FIGS. 1-5, except that the pivot joint 154 is omitted, but the pivot pin 164 is installed in the openings 160, 162, for mounting the rear, upwardly-concave link 146 to the base-mounting bracket 42 at a correspondingly different (shorter) distance relative to the pivot joint 136 of the short, slotted link 134 to the base-mounting bracket 42.
The mechanism 12' is mounted to a chair 10 in the same manner as has been described in relation to FIGS. 1-5. However, due to the single difference in the placement of the pivot joint which has just been described, as the chair is fully reclined from the TV position, the relationship of the seat to the back remains the same (or nearly so), so that the mechanism 12' thereby provides a two-way, three-position chair.
The difference in back to seat orientation between two-way and a three-way operation in the third (fully reclined) position can best be seen by comparing FIGS. 5 and 7.
(The mechanisms 12, 12' appear somewhat differently in FIGS. 5 and 7 than in FIGS. 2-4 and 6, because, in FIGS. 5 and 7, one is looking directly at the outboard side of a left side mechanism, rather than at the inboard side of a right side mechanism.)
It should now be apparent that the mechanism for high-leg reclining chair as described hereinabove, possesses each of the attributes set forth in the specification under the heading "Summary of the Invention" hereinbefore. Because it can be modified to some extent without departing from the principles thereof as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the spirit and scope of the following claims. | A pair of side mechanisms mount a back, seat and ottoman on a high-leg chair frame. Although the mechanisms are short, and require less longitudinal travel in operation, they can be used not only for chairs with two-way operation but also three-way operation. The mechanism does not protrude under the seat in use, so the frame legs may be as tall as the aesthetic design requires. The back is secure in the upright position. The sequence link of each mechanism operates on the rear pivot link of the mechanism. The ottoman linkage, including a spring, locks the ottoman in the upright position, although the lock can be overcome by the user pushing forward on the arms of the chair. | 0 |
[0001] This invention relates to compounds, compositions and methods for potentiating the action of chemotherapeutic agents, for reducing the dose required for therapeutic effectiveness, and for overcoming resistance to the chemotherapeutic agent. The invention also provides novel aldehyde-releasing compounds which increase the efficacy of chemotherapeutic agents.
BACKGROUND OF THE INVENTION
[0002] Many diseases that afflict animals, including humans, are treated with chemotherapeutic agents. For example, chemotherapeutic agents have proven valuable in the treatment of neoplastic disorders such as cancer, connective or autoimmune diseases, metabolic disorders, and dermatological diseases. Some of these agents are highly effective and do not suffer from any bioavailability or toxic side effect problems such as neutropenia. Unfortunately, many chemotherapeutic agents have severe problems with bioavailability and/or toxic side effects that adversely affect their clinical usefulness.
[0003] The anthracycline group of compounds contains some of the most widely used of all the anti-cancer agents in current clinical use, including Adriamycin which is used in the treatment of a wide range of tumours (Weiss, 1992; DeVita et al., 1993; Pratt et al., 1994; Bishop, 1999). In addition to Adriamycin, other members of this group including daunomycin (2), idarubicin (3), and epirubicin (4) are commonly used. The chemical, biochemical and pharmacological properties of these chemotherapeutic agents have been described in detail (Myers et al., 1988; DeVita et al., 1993; Sweatman and Israel, 1997; Gewirtz, 1999; Phillips and Cullinane, 1999).
[0004] Structures of commonly used anthracyclines 1, Adriamycin; 2, daunomycin; 3, idarubicin; 4, epirubicin.
[0005] Although the anthracyclines have been used for well over two decades, their mechanism of action is not yet fully understood. The lack of understanding of the molecular details of the mechanism of action of the anthracyclines has hindered the development of improved anthracyclines, and this has been exemplified by the fact that over 2,000 derivatives have been assessed to date without yielding new derivatives with substantially improved activity (Weiss, 1992; Phillips and Cullinane, 1999).
[0006] The clinical use of the anthracyclines has also been hindered by two further problems:
[0007] 1. a cumulative, dose-dependent cardiomyopathy which restricts the maximum recommended dose to 550 mg/m 2 ;
[0008] 2. the development of resistance following extended periods of use, due primarily to the over-expression of the active efflux pump P-glycoprotein, but also to a range of other detoxification mechanisms (Chabner and Myers, 1993; Pratt et al., 1994; Sweatman and Israel, 1997).
[0009] Using a transcription assay, the Applicant has shown that Adriamycin is able to form adducts with DNA under appropriate in vitro conditions, and that these adducts form almost exclusively at guanine residues, although mainly at 5′-GC-3′ sequences. The Applicant has also shown that these adducts can be detected in both the nuclear and mitochondrial DNA of cells in culture which have been exposed to Adriamycin. Moreover, the Applicant has revealed a clear correlation between the formation of these DNA adducts and a cytotoxic response, as well as a requirement for the presence of aldehyde, and in particular formaldehyde. The aldehyde has been found to be advantageously provided to the system by a compound that releases aldehyde in situ. Applicant has also found that there was a surprising dependence on the relative order and timing of addition of the chemotherapeutic agent/aldehyde-releasing compound combination.
[0010] From these results the Applicant has now defined a model for the molecular processes involved in the action of Adriamycin, and how the cellular responses to Adriamycin can be directed down one reaction pathway by the use of aldehyde-releasing compounds (also referred to as an. “aldehyde-releasing prodrug” or “prodrug”). This model is shown below:
[0011] This model shows that Adriamycin and other anthracyclines may induce cell killing by several different mechanisms. For simplicity only two such possible pathways have been shown: one involving impairment of the topological enzyme topoisomerase II, the apparent central target, and the other involving the formation of DNA adducts. On the basis of this model the Applicant predicts that in the presence of excess aldehydes, in particular formaldehyde, Adriamycin will be directed down the DNA adduct pathway.
[0012] This leads to several predictions as to the cellular response under such conditions:
[0013] (1) The number of adducts will increase with the aldehyde-releasing compound:chemotherapeutic agent ratio, up to saturation of the available chemotherapeutic agent pool;
[0014] (2) The greater the number of DNA adducts, the greater will be the cytotoxic response; and
[0015] (3) The time of addition of chemotherapeutic agent and aldehyde-releasing compound will affect the extent of adduct formation.
[0016] As shown herein, all of these responses have been confirmed in cells treated in culture with Adriamycin and the aldehyde-releasing compound AN-9, providing good evidence in support of the model.
[0017] All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country.
[0018] For the purposes of this specification it will be clearly understood that the word “comprising” means “including but not limited to”, and that the word “comprises has a corresponding meaning.
SUMMARY OF THE INVENTION
[0019] Applicant has found that certain chemotherapeutic agents such as anthracyclines and related compounds such as anthracenediones, when combined with compounds that increase or supplement the intracellular levels of aldehyde, such as aldehyde-releasing compounds, result in enhanced levels of formation of drug-DNA adducts, leading to an increased cytotoxic response, the response being defined by the relative aldehyde-releasing compound:chemotherapeutic agent ratio, relative time and duration of administration. This could enable decreased levels of the chemotherapeutic agent to be used, thereby reducing the risk of toxic side effects of the therapy.
[0020] Accordingly, in a first aspect, the invention provides a method of treating cancer, comprising the step of administering to a subject in need thereof an effective amount of a compound or compounds which increase or supplement the intracellular levels of endogenous aldehyde, prior to, together with, or subsequent to the administration of a therapeutically-effective amount of a chemotherapeutic agent, wherein the efficacy of the chemotherapeutic agent is enhanced relative to the efficacy of the chemotherapeutic agent alone.
[0021] In one preferred embodiment, the invention further provides a method of treating cancer, comprising the step of administering to a subject in need thereof an effective amount of an aldehyde-releasing compound prior to, together with, or subsequent to the administration of a therapeutically-effective amount of a chemotherapeutic agent, wherein the efficacy of the chemotherapeutic agent is enhanced relative to the efficacy of the chemotherapeutic agent alone.
[0022] In a second aspect, the invention provides a method of preferentially forming a chemotherapeutic agent-DNA adduct, comprising the step of administering to a subject in need thereof an effective amount of an aldehyde-releasing compound prior to, together with, or subsequent to the administration of a therapeutically-effective amount of a chemotherapeutic agent, wherein the chemotherapeutic agent more readily forms and/or increasingly forms, DNA adducts than compared to the chemotherapeutic agent alone.
[0023] Preferably the chemotherapeutic agent is an anthracycline such as Adriamycin, daunomycin, idarubicin or epirubicin, or an anthracenedione such as mitoxantrone. Adriamycin is particularly preferred.
[0024] The aldehyde releasing compound may be any compound that releases an aldehyde in situ. Aldehyde is released by decomposition of the compound or by hydrolysis of the compound by intracellular esterases. It is to be understood that the term aldehyde releasing compound should be interpreted broadly so as to include compounds that undergo a reaction in situ to form another compound that is then hydrolysed or decomposes to form an aldehyde. The aldehyde is usually released with at least one further compound, such as an acid.
[0025] Compounds that may release aldehyde in a given environment require at least one —CHR— unit with groups immediately adjacent to this unit that decompose or hydrolyse in situ. Accordingly, this term encompasses a very broad range of compounds, including:
[0026] (a) those compounds known to release aldehyde (particularly formaldehyde), such as hexamethylmelamine (altretamine) and hexamethylenetetramine (see for instance Ashby and Lefevre, 1982)
[0027] (b) diester compounds containing an ester to each side of the —CHR— unit, (ie R a C(═O)O—CHR—OC(═O)R b , wherein R a and R b independently have the same definitions as R 1 referred to below) including but not limited to compounds disclosed in U.S. Pat. No. 6,110,970, U.S. Pat. No. 6,040,342, U.S. Pat. No. 6,043,277, U.S. Pat. No. 5,710,176, U.S. Pat. No. 5,200,553, U.S. Pat. No. 6,130,248 and U.S. Pat. No. 6,043,389.
[0028] (c) compounds containing any two acid ester groups to either side of the —CHR— unit, such as compounds containing a carboxylic acid ester group and an ester based on an acid of phosphorous [eg (R′O) 2 —P(═O), R′,R″O—P(═O) or R′ 2 —P(═O)] to either side of the —CHR— unit, including but not limited to compounds disclosed in U.S. Pat. No. 6,030,961
[0029] (d) compounds containing groups to either side of the —CHR— unit that will undergo hydrolysis (eg enzymatic hydrolysis) or decomposition to release formaldehyde, including compounds of the formula (I)
X—CHR—Y (I)
[0030] wherein:
[0031] X— and/or Y— is a group that can be converted to OH, NH or SH in situ, so that upon hydrolysis or decomposition the compound releases an aldehyde; and preferably X and Y are each independently —OR 1 ; —NHR 2 ; —NR 3 R 4 ; —SR 5 ; —OAcyl; —SAcyl, a phosphorous acid radical, or a phosphoramide radical, or one of X and Y may be a halogen or hydrogen;
[0032] in which
[0033] R 1 , R 2 , and R 5 are each independently optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl, optionally substituted aralkenyl or optionally substituted aralkynyl group, and
[0034] R 3 and R 4 each independently have the same definitions as R 1 , R 2 and R 5 above, or R 3 and R 4 may together with the nitrogen atom form an optionally substituted heterocyclic ring (eg a morpholine ring); and
[0035] (e) one of the new aldehyde-releasing compounds described in further detail below.
[0036] It is to be noted that the compounds of formula (I) above include within their scope the compounds set out in paragraphs a, b and c.
[0037] The term “alkyl” used either alone or in a compound word such as Optionally substituted alkyl or “optionally substituted cycloalkyl” denotes straight chain, branched or mono- or poly-cyclic alkyl, preferably C1-30 alkyl or cycloalkyl. Examples of straight chain and branched alkyl include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, isoamyl, sec-amyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, hexyl, 4-methylpentyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 1,2,2-trimethylpropyl, 1,1,2-trimethylpropyl, heptyl, 5-methylhexyl, 1-methylhexyl, 2,2-dimethylpentyl, 3,3-dimethylpentyl, 4,4-dimetylpentyl, 1,2-dimethylpentyl, 1,3-dimethylpentyl, 1,4-dimethylpentyl, 1,2,3-trimethylbutyl, 1,1,2-trimethylbutyl, nonyl, 1-, 2-, 3-, 4-, 5-, 6- or 7-methyloctyl, 1-, 2-, 3-, 4- or 5-ethylheptyl, 1-2- or 3-propylhexyl, decyl, 1-, 2-, 3-, 4-, 5-, 6-, 7- and 8-methylnonyl, 1-, 2-, 3-, 4-, 5- or 6-ethyloctyl, 1-, 2-, 3- or 4-propylheptyl, undecyl 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-methyldecyl, 1-, 2-, 3-, 4-, 5-, 6- or 7-ethylnonyl, 1-, 2-, 3-, 4- or 5-propyloctyl, 1-, 2- or 3-butylheptyl, 1-pentylhexyl, dodecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9- or 10-methylundecyl, 1-, 2-, 3-; 4-, 5-, 6-, 7- or 8-ethyldecyl, 1-, 2-, 3-, 4-, 5- or 6-propylnonyl, 1-, 2-, 3- or 4-butyloctyl, 1-2-pentylheptyl and the like. Examples of cyclic alkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl and cyclodecyl and the like.
[0038] The term “alkenyl” used either alone or in compound words such as “alkenyloxy” denotes groups formed from straight chain, branched or cyclic alkenes including ethylenically mono-, di- or poly-unsaturated alkyl or cycloalkyl groups as defined above, preferably C2-20 alkenyl. Examples of alkenyl include vinyl, allyl, 1-methylvinyl, butenyl, iso-butenyl, 3-methyl-2-butenyl, 1-pentenyl, cyclopentenyl, 1-methyl-cyclopentenyl, 1-hexenyl, 3-hexenyl, cyclohexenyl, 1-heptenyl, 3-heptenyl, 1-octenyl, cyclooctenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 3-decenyl, 1,3-butadienyl, 1-4,pentadienyl, 1,3-cyclopentadienyl, 1,3-hexadienyl, 1,4-hexadienyl, 1,3-cyclohexadienyl, 1,4-cyclohexaidenyl, 1,3-cycloheptadienyl, 1,3,5-cycloheptatrienyl and 1,3,5,7-cyclooctatetraenyl.
[0039] The term “alkynyl” used either alone or in compound words such as “alkynyloxy” denotes groups formed from straight chain, branched or cyclic alkynes including ethylynically mono-, di- or poly-unsaturated alkyl or cycloalkyl groups as defined above, preferably C 2-20 alkynyl. The alkynyl preferably contains between 1 and 6 triple bonds. Examples of alkynyl include acetylenyl, prop-2-ynyl, pent-3-ynyl, hex-5-ynyl, 5-ethyldodec-3,6-diynyl, and the like.
[0040] The term “alkoxy” used either alone or in compound words such as “optionally substituted alkoxy” denotes straight chain or branched alkoxy, preferably C1-30 alkoxy. Examples of alkoxy include methoxy, ethoxy, n-propyloxy, isopropyloxy and the different butoxy isomers.
[0041] The term “acyl” used either alone or in compound words such as “optionally substituted acyl” or “optionally substituted acyloxy” denotes carbamoyl, aliphatic acyl group and acyl group containing an aromatic ring, which is referred to as aromatic acyl or a heterocyclic ring which is referred to as heterocyclic acyl, preferably C1-30 acyl. Examples of acyl include carbamoyl; straight chain or branched alkanoyl such as formyl, acetyl, propanoyl, butanoyl, 2-methylpropanoyl, pentanoyl, 2,2-dimethylpropanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl, tridecanoyl, pentadecanoyl, hexadecanoyl, heptadecanoyl, octadecanoyl, nonadecanoyl and icosanoyl; alkoxycarbonyl such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, t-pentyloxycarbonyl and heptyloxycarbonyl; cycloalkylcarbonyl such as cyclopropylcarbonyl cyclobutylcarbonyl, cyclopentylcarbonyl and cyclohexylcarbonyl; alkylsulfonyl such as methylsulfonyl and ethylsulfonyl; alkoxysulfonyl such as methoxysulfonyl and ethoxysulfonyl; aroyl such as benzoyl, toluoyl and naphthoyl; aralkanoyl such as phenylalkanoyl (e.g. phenylacetyl, phenylpropanoyl, phenylbutanoyl, phenylisobutyl, phenylpentanoyl and phenylhexanoyl) and naphthylalkanoyl (e.g. naphthylacetyl, naphthylpropanoyl and naphthylbutanoyl); aralkenoyl such as phenylalkenoyl (e.g. phenylpropenoyl, phenylbutenoyl, phenylmethacrylyl, phenylpentenoyl and phenylhexenoyl and naphthylalkenoyl (e.g. naphthylpropenoyl, naphthylbutenoyl and naphthylpentenoyl); aralkoxycarbonyl such as phenylalkoxycarbonyl (e.g. benzyloxycarbonyl); aryloxycarbonyl such as phenoxycarbonyl and naphthyloxycarbonyl; aryloxyalkanoyl such as phenoxyacetyl and phenoxypropionyl; arylcarbamoyl such as phenylcarbamoyl; arylthiocarbamoyl such as phenylthiocarbamoyl; arylglyoxyloyl such as phenylglyoxyloyl and naphthylglyoxyloyl; arylsulfonyl such as phenylsulfonyl and naphthylsulfonyl; heterocycliccarbonyl; heterocyclicalkanoyl such as thienylacetyl, thienylpropanoyl, thienylbutanoyl, thienylpentanoyl, thienylhexanoyl, thiazolylacetyl, thiadiazolylacetyl and tetrazolylacetyl; heterocyclicalkenoyl such as heterocyclicpropenoyl, heterocyclicbutenoyl, heterocyclicpentenoyl and heterocyclichexenoyl; and heterocyclicglyoxyloyl such as thiazolylglyoxyloyl and thienylglyoxyloyl.
[0042] The term “aryl” used either alone or in compound words such as “optionally substituted aryl”, “optionally substituted aryloxy” or “optionally substituted heteroaryl” denotes single, polynuclear, conjugated and fused residues of aromatic hydrocarbons or aromatic heterocyclic ring systems. Examples of aryl include phenyl, biphenyl, terphenyl, quaterphenyl, phenoxyphenyl, naphtyl, tetrahydronaphthyl, anthracenyl, dihydroanthracenyl, benzanthracenyl, dibenzanthracenyl, phenanthrenyl, fluorenyl, pyrenyl, indenyl, azulenyl, chrysenyl, pyridyl, 4-phenylpyridyl, 3-phenylpyridyl, thienyl, furyl, pyrryl, pyrrolyl, furanyl, imadazolyl, pyrrolydinyl, pyridinyl, piperidinyl, indolyl, pyridazinyl, pyrazolyl, pyrazinyl, thiazolyl, pyrimidinyl, quinolinyl, isoquinolinyl, benzofuranyl, benzothienyl, purinyl, quinazolinyl, phenazinyl, acridinyl, benzoxazolyl, benzothiazolyl and the like. Preferably, the aromatic heterocyclic ring system contains 1 to 4 heteratoms independently selected from N, O and S and containing up to 9 carbon atoms in the ring.
[0043] The term “heterocyclyl”used either alone or in compound words such as “optionally substituted saturated or unsaturated heterocyclyl” denotes monocyclic or polycyclic heterocyclyl groups containing at least one heteroatom atom selected from nitrogen, sulphur and oxygen. Suitable heterocyclyl groups include N-containing heterocyclic groups, such as, unsaturated 3 to 6 membered heteromonocyclic groups containing 1 to 4 nitrogen atoms, for example, pyrrolyl, pyrrolinyl, imidazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazolyl or tetrazolyl;
[0044] saturated 3 to 6-membered heteromonocyclic groups containing 1 to 4 nitrogen atoms, such as, pyrrolidinyl, imidazolidinyl, piperidino or piperazinyl;
[0045] unsaturated condensed heterocyclic groups containing 1 to 5 nitrogen atoms, such as indolyl, isoindolyl, indolizinyl, benzimidazolyl, quinolyl, isoquinolyl, indazolyl, benzotriazolyl or tetrazolopyridazinyl;
[0046] unsaturated 3 to 6-membered heteromonocyclic group containing an oxygen atom, such as, pyranyl or furyl;
[0047] unsaturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulphur atoms, such as, thienyl;
[0048] unsaturated 3 to 6-membered heteromonocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, such as, oxazolyl, isoxazolyl or oxadiazolyl;
[0049] saturated 3 to 6-membered heteromonocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, such as, morpholinyl;
[0050] unsaturated condensed heterocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, such as, benzoxazolyl or benzoxadiazolyl;
[0051] unsaturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulphur atoms and 1 to 3 nitrogen atoms, such as, thiazolyl or thiadiazolyl;
[0052] saturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulphur atoms and 1 to 3 nitrogen atoms, such as, thiazolidinyl; and
[0053] unsaturated condensed heterocyclic group containing 1 to 2 sulphur atoms and 1 to 3 nitrogen atoms, such as benzothiazolyl or benzothiadiazolyl.
[0054] The terms “aralkyl”, “aralkenyl” and “aralkynyl” refer to alkyl, alkenyl and alkynyl, respectively, substituted with an aryl or heteroaryl group.
[0055] In this specification “optionally substituted” means that a group may or may not be further substituted with one or more groups selected from alkyl, alkenyl, alkynyl, aryl, halo, haloalkyl, haloalkenyl, haloalkynyl, haloaryl, hydroxy, alkoxy, alkenyloxy, aryloxy, benzyloxy, haloalkoxy, haloalkenyloxy, haloaryloxy, nitro, nitroalkyl, nitroalkenyl, nitroalkynyl, nitroaryl, nitroheterocyclyl, amino, alkylamino, dialkylamino, alkenylamino, alkynylamino, arylamino, diarylamino, benzylamino, dibenzylamino, acyl, alkenylacyl, alkynylacyl, arylacyl, acylamino, diacylamino, acyloxy, alkylsulphonyloxy, arylsulphenyloxy, heterocyclyl, heterocycloxy, heterocyclamino, haloheterocyclyl, alkylsulphenyl, arylsulphenyl, carboalkoxy, carboaryloxy, mercapto, alkylthio, benzylthio, acylthio, phosphorus-containing groups and the like. Preferred substituents in each instance are alkoxy, alkylthio, hydroxy, halogen, cyano, azido, alkylsulfonyl, oxo and acyloxy, unless otherwise indicated.
[0056] “Halide” or “halo” denotes fluorine, chlorine, bromine or iodine, and preferably F or Cl.
[0057] The term “phosphorous acid radical” denotes one of the phosphorous acids such as (R 6 O) 2 —P(═O), R 7 ,R 80 —P(═O) or R 9 2 —P(═O), in which R 6 , R 7 , R 8 and R 9 each independently have the same definitions as R 1 above.
[0058] The term “phosphoramide radical” is used in this specification in its broadest sense to refer to a radical containing a phosphorous-oxygen double bond, with the same phosphorous atom being bound to a nitrogen atom by a single bond. This nitrogen atom is the one through which the phosphoramide radical is connected to the —CHR— unit. Usually, the phosphoramide radical contains three nitrogen atoms bound to the phosphorous atom in addition to the double-bonded oxygen atom. An example is heptamethyl phosphoramido.
[0059] The aldehyde releasing compounds release one or more further compounds in addition to the aldehyde. The diester compounds referred to under paragraph (b) above release two acids, which, depending on the ester units, may be butyric acid, retinoic acid or any other acid. The compounds referred to under paragraph (c) above release a phosphorous acid.
[0060] In order to avoid any doubt whatsoever, the following explanation is provided of the mechanism by which aldehyde is released from suitable aldehyde releasing compounds in situ. Further information may also be found in Ashby and Lefevre (1982), the entire disclosure of which is incorporated herein by reference. This explanation will assist the person skilled in the art to comprehend the meaning of the term hydrolysable or decomposable group, and therefore the full range of compounds that will release formaldehyde in the given conditions.
[0061] The atom to either side of the —CHR— unit in the aldehyde-releasing compound may be any heteroatom such as O, N or S, or it can be a halogen, if the halogen can be replaced with a heteroatom by reaction in situ. There is a requirement that at least one of the groups to either side of the —CHR— unit must be converted to OH, NH or SH in situ. For instance, ClCH 2 Cl where X═Y═Cl is a stable compound that would not decompose readily to release formaldehyde. On the other hand, the compound C 1 -CH 2 —OH (in which the heteroatom is O, and is connected to a hydrogen atom) is unstable and undergoes instantaneous decomposition to formaldehyde H 2 C═O and HCl. In another example, MeO—CH 2 —OMe is very stable, however in the presence of an acid one of the ether oxygen atoms is protonated, and the protonated compound is destabilised releasing formaldehyde and 2 MeOH moieties. This is also the pathway of decomposition of hexamethylenetetramine, which requires acidic conditions to protonate one nitrogen atom giving a — + NH—CH 2 —N— intermediate that again hydrolyzes to give 6 formaldehyde and 4 NH 3 moieties.
[0062] It is noted that the heteroatom immediately next to the —CHR— cannot be part of an electron withdrawing group, as this stabilises the compound. Accordingly, MeCONH—CH 2 —OH or MeCOCH—CH 2 —NH, are too stable to be efficient sources of formaldehyde.
[0063] Preferably, R in the unit —CHR— is H or C1-4 alkyl, alkenyl or alkynyl. It is most preferred that aldehyde released be formaldehyde (ie the —CHR— unit in the aldehyde releasing compound is —CH 2 —). Nevertheless, smaller aldehydes such as acetaldehyde, propanal, butanal and butenal (eg 2-butenal) may also be suited for use in combination therapies with certain chemotherapeutic agents, and therefore compounds that release these smaller aldehydes are to be considered to be within the broad concept of the invention.
[0064] The present Applicant has developed a new range of aldehyde releasing compounds that have been found to give surprisingly excellent results in adduct formation tests. One class of new aldehyde releasing compounds of formula (II) release more than one equivalent of aldehyde:
Z-(L-M′-CHR-M 2 ) x (II)
[0065] wherein:
[0066] x is an integer of 2 or more;
[0067] Z is a direct bond or a linking group of valency x;
[0068] L is either a direct bond or a spacer group;
[0069] R is H or C1-4 alkyl, alkenyl or alkynyl;
[0070] M 1 is a decomposable or hydrolysable group; and
[0071] M 2 is a second decomposable or hydrolysable group.
[0072] Z may be a direct bond (when x=2) or any group that can link the bracketed portions of the compound together (ie a Blinking groups). For example, Z may be N (x=3, or 2 if the nitrogen atom includes another substituent), P(═O), PO, O, S, an optionally substituted C1-20 alkylene, alkenylene or alkynylene chain, which may optionally be interspersed with one or more aryl or heteroaryl groups (which may also be optionally substituted) and/or one or more O, S or N atoms; or Z may be an optionally substituted heterogenous cyclic group, an aryl group or heteroaryl group.
[0073] The terms “alkylene”, “alkenylene” and “alkynylene” are the divalent radical equivalents of the terms “alkyl” “alkenyl” and “alkynyl”, respectively. The two bonds connecting the alkylene, alkenylene or alkynylene to the adjacent groups may come from the same carbon atom or different carbon atoms in the divalent radical.
[0074] Preferred optional substituents in the linker group Z are selected from halogen, oxy, hydroxy, alkoxy, alkylthio, cyano, azido, acyloxy, alkylsulphonyl, aryl and heteroaryl.
[0075] It will be understood that in addition to being a linking group, Z could have a second function. For example, Z could be a radical based on the chemotherapeutic agent itself.
[0076] The term “spacer group” is to be interpreted broadly so as to include any divalent organic group that separates the next adjacent groups from one another (eg groups Z and M 1 ). As a consequence, L may be any one of the groups outlined above for Z where Z has a valency of 2.
[0077] In the situation where x is 2, Z and L may each be a direct bond, such that M 1 of one of the bracketed groups (hereinafter referred to as “chain a”, and therefore M 1a refers to M 1 in chain a) is directly connected to M 1 of the second of the bracketed groups (referred to as “chain b”). For example, in one preferred embodiment of the invention, M 1a -M 1b is —O—C(═O)—C(═O)—C—O—. It is also to be noted that the hydrolysable groups M 1a and M 1b in this embodiment may form part of the one group. That is, -M 1a -M 1b could for example be —O—C(═O)—O—.
[0078] Each M 2 in the compound (ie M 2a , M 2b , etc) is independently any hydrolysable or decomposable group as described above in relation to the mechanism for the formation of aldehyde in situ, and in one preferred embodiment each M 2 has the same definition as X (or Y) outlined above.
[0079] Each M 1 in the compound (ie M 1a , M 2a , etc) is independently any hydrolysable or decomposable group as described above. M 1 is the divalent radical equivalent of M 2 .
[0080] Each group L, M 1 , R and M 2 in each chain (chains a, b etc) may be the same or different. Accordingly, the compounds may be symmetrical or unsymmetrical.
[0081] As a consequence of the above, the new compounds include compounds of the formula (III):
X′—CH 2 —OOC-Z′-COO—CH 2 —Y′ (III),
[0082] in which X′ and Y′ have the same definitions as X and Y described above for the compounds of formula (I), respectively, and Z′ has the same definition as Z described above for the compound of formula (II), where Z has a valency of 2.
[0083] In one embodiment of the compound of formula III, Z′ is an optionally substituted cyclic alkylidene, an optionally substituted cyclic alkenylidene, an optionally substituted cyclic alkynylidene, an optionally substituted heterocyclic group, an optionally substituted aryl or an optionally substituted heteroaryl group. Thus —OOC-Z′-COO— may be a fragment from a dicarboxy-substituted saturated or unsaturated cyclic diacid, which may be an alicyclic, heterocyclic, aromatic or heteroaromatic ring system, such as 1,3-dicarboxy-cyclohexane; phthalic acid; 2,5-dicarboxy-thiazole; 2,5-dicarboxy-tetrahydrofuran; 3,4-dicarboxy-thiophen; 3,4-dicarboxy-oxazolidine-2-one.
[0084] Where Z′ is a direct bond, —OOC-Z′-COO— may be a fragment derived from oxalic acid.
[0085] Where Z′ is alkylidene, —OOC-Z′-COO— may be a fragment derived for example from malonic acid, succinic acid or glutaric acid. Where Z′ is alkenylidene, —OOC-Z′-COO— may be a fragment derived for example from maleic acid or fumaric acid.
[0086] The present invention also provides a method of synthesising the new compound of formula (II) described above, the method including the step of reacting a compound from which the fragment Z-(L-M 1 -), is derived, with a compound from which the fragment —CHR-M 2 is derived, to form the compound of formula (II). In the situation where the compound from which the fragment Z-(L-M 1 -) x is derived is an acid, the compound from which the fragment —CHR-M 2 is derived may be Hal-CHR-M 2 , in which Hal refers to a halogen or another suitable leaving group. These two fragments can then be reacted together in the presence of a base.
[0087] The leaving group may be one of those disclosed in March, 1992, the entire disclosure of which is incorporated herein by reference.
[0088] Therapeutic effectiveness may be further improved by localisation of the aldehyde-releasing compounds to tumour tissues and/or sub-cellular compartments of tumour cells. Thus preferably the aldehyde-releasing compound is preferentially targeted to the tumour. This may be achieved by any suitable method, including but not limited to:
[0089] (a) coupling the aldehyde-releasing compound to a cellular or subcellular targeting sequence, such as a nuclear targeting sequence; and
[0090] (b) coupling the aldehyde-releasing compound to a tumour-localising component, such as an antibody or an antibody-derived fragment specific for a tumour cell marker.
[0091] As a consequence, the present invention also provides a compound which includes an aldehyde-releasing compound as described above coupled to a cellular or subcellular targeting sequence or a tumour-localising component.
[0092] Polyclonal or monoclonal antibodies may be used, and may be made by methods known in the art; preferably the antibody is a monoclonal antibody. Suitable antibody-derived fragments include ScFv fragments; suitable tumour cell markers are tumour-specific cell surface or intracellular antigens.
[0093] The aldehyde-releasing compound preferably releases aldehyde mainly in tumour tissues. The intracellular level of aldehyde can be further enhanced by reducing the level of aldehyde detoxifying agents in the tissues. The aldehyde detoxifying agents present in the tissues include GSH, GSH-dependent formaldehyde dehydrogenase, mitochondrial aldehyde dehydrogenase (non-glutathione-dependent) and other alcohol dehydrogenases. These agents detoxify the formaldehyde by oxidising the formaldehyde. Inhibitors of these enzymes include buthionine sulfoximine (BSO) (which lowers glutathione (GSH) levels by inhibiting gamma-glutamyl synthetase), Daidzin and crotonaldehyde (which inhibit mitochondrial aldehyde dehydrogenase—see Keung and Vallee, 1993 and Dicker and Cederbaum, 1984, respectively), semicarbazides, dimedone and resveratrol (which all act by direct binding to formaldehyde), diethyl maleate, phorone and cyanamide.
[0094] It follows from the above that the method of the present invention may involve administering a compound that reduces the intracellular level of one or more aldehyde detoxifying agents. This compound may be separate to the aldehyde-releasing compound, or otherwise a single compound may be both the aldehyde-releasing compound and the compound that reduces the intracellular level of the aldehyde detoxify
[0095] In one particular embodiment of the present invention, there is provided an aldehyde releasing compound including a radical based on an inhibitor of an aldehyde detoxifying agent, which aldehyde releasing compound releases said inhibitor and an aldehyde on hydrolysis or decomposition in situ. It is to be understood that the agent and the aldehyde may be one and the same in this embodiment of the invention, as is explained by way of example below.
[0096] Preferably the inhibitor of an aldehyde detoxifying agent is selected from the group consisting of inhibitors of gamma-glutamyl synthetase and inhibitors of alcohol and aldehyde dehydrogenases. Preferably the inhibitor is buthionine sulfoximine or crotonaldehyde, or a derivative of one of these inhibitors.
[0097] This class of new compounds therefore includes compounds of the formula (IV)
M 3 -CHR-M 4 (IV)
[0098] where M 3 and M 4 are each independently a hydrolysable or decomposable group, and
[0099] M 3 and/or M 4 and/or R is a radical based on an inhibitor of an aldehyde detoxifying agent.
[0100] The term “based on” in this context means that the radical is selected such that when the aldehyde-releasing compound is decomposed or hydrolysed, the portion of the compound that contains the specified radical is decomposed or hydrolysed to form said inhibitor. In one embodiment of this aspect of the invention, M 3 is a BSO radical. Accordingly, aldehyde-releasing compounds of this class include the oxymethylesters of BSO which release formaldehyde and BSO on cellular hydrolysis, the BSO functioning to limit formaldehyde detoxification. In another embodiment, R is a radical based on crotonaldehyde (ie a 2-butenyl radical) such that crotonaldehyde is released on hydrolysis. In a preferred embodiment, M 4 has the same definition as Y in the compound of formula (I) above.
[0101] The present invention also provides a method of synthesising an aldehyde releasing compound of the formula M 3 -CHR-M 4 (as defined above) in which M 3 is a radical based on an inhibitor of an aldehyde detoxifying agent, the method comprising the step of coupling the radical based on said inhibitor to a radical —CHR-M 4 . In the situation where the inhibitor is a carboxylic acid (eg when the inhibitor is BSO), the method may involve the step of reacting the inhibitor with the compound Hal-CHR-M 4 , wherein R and M are as defined above, and Hal is a halogen or halogen-like group (eg a leaving group such as a tosylate group) in the presence of a base.
[0102] The new classes of compounds of formulae (II) and (III) referred to above should be understood to include within their scope compounds that release one or more equivalents of an inhibitor of an aldehyde detoxifying agent, together with two or more equivalents of aldehyde. In this embodiment, M 2 should be understood to include BSO. In addition, in the case where the agent that enhances intracellular levels of aldehyde is crotonaldehyde, one or more of the aldehydes released in the molecule could be crotonaldehyde (ie R (eg R a ) is —CH═CHCH 3 ).
[0103] In a fourth aspect, the invention provides a composition comprising
[0104] (a) a chemotherapeutic agent which is a primary or secondary amine, and
[0105] (b) an aldehyde-releasing compound which upon hydrolysis releases one or more equivalents of formaldehyde, together with a pharmaceutically-acceptable carrier.
[0106] The aldehyde-releasing compound may be any one of the known aldehyde-releasing agents, or one of the new aldehyde-releasing agents described above.
[0107] In a fifth aspect, the invention provides a composition comprising one or more of the new aldehyde-releasing compounds as defined above, together with a pharmaceutically-acceptable carrier.
[0108] In a sixth aspect the invention provides for the use of an aldehyde-releasing compound in the manufacture of a medicament for the treatment and/or prophylaxis of cancer. Preferably the aldehyde-releasing compound is one of the new aldehyde-releasing compounds described above.
[0109] In a seventh aspect the invention provides a method of treating cancer comprising the steps of:
[0110] (a) determining the optimum time of administration of a therapeutically effective amount of an aldehyde-releasing compound relative to the administration of a chemotherapeutic agent wherein the optimum time is determined by the number of DNA adducts formed;
[0111] (b) determining the amount of aldehyde-releasing compound relative to the amount of chemotherapeutic agent;
[0112] (c) from step (a) and (b) determining the amount and timing of delivery of aldehyde-releasing compound and chemotherapeutic agent and administering to a patient in need thereof.
[0113] The major potential benefits of the method of the invention are:
[0114] (1) The higher level of tumour cell killing resulting from the combined use of an active chemotherapeutic agent (eg anthracycline or anthracenedione) and an aldehyde-releasing compound enables the chemotherapeutic agent to be used at lower doses in order to achieve the same level of cell killing, hence decreasing the level of undesired side effects of the chemotherapeutic agent (eg cardiotoxicity).
[0115] (2) The co-administration of an anthracycline or anthracenedione with an aldehyde-releasing compound is predicted to be effective against anthracycline-resistant cells, because the chemotherapeutic agent will form adducts with DNA rather than be subjected to active efflux, or other detoxifying mechanisms.
[0116] (3) Targeting of the aldehyde-releasing compound to the tumour localises the formation of chemotherapeutic agent-DNA adducts preferentially to tumours, and hence localises the cell killing primarily to the tumour, thus minimising the side effects which result from damage to normal tissues.
[0117] (4) The potentiation of adduct formation can be utilized as a diagnostic tool for the optimisation of chemotherapeutic agent dosage and the prediction of tumour response to the treatment with the aldehyde-releasing compound/chemotherapeutic agent combinations.
BRIEF DESCRIPTION OF THE FIGURES
[0118] [0118]FIG. 1 illustrates the formation of DNA adducts in IMR-32 (human neuroblastoma) and MCF-7 (human breast adenocarcinoma) cells in the presence of AN-9 and Adriamycin. IMR-32 human neuroblastoma cells (A and B) and MCF-7 human breast adenocarcinoma cells (C and D) were treated with Adriamycin for 2 hr, followed by a further 2 hr incubation with a 25-fold excess of AN-9 (▪), or with AN-9 for 2 hr followed by a further 4 hr incubation with Adriamycin (□).
[0119] [0119]FIG. 2 shows the time-dependent formation of adducts in the mitochondrial genome (A) and DHFR gene (B).
[0120] [0120]FIG. 3 shows the effect on enhanced adduct formation of the order of addition of Adriamycin and AN-9. Adduct/crosslinking levels for both mitochondrial (A) and nuclear (B) DNA are shown.
[0121] [0121]FIG. 4 shows that reversing the order of addition results in diminished adduct formation. Adduct/crosslinking levels for both mitochondrial (A) and nuclear (B) DNA are shown.
[0122] [0122]FIG. 5 shows the effect of AN-9 on barminomycin-induced crosslinking of mitochondrial (A) and nuclear DNA (B). IMR-32 cells were treated with barminomycin alone (0-20 DM, ▪) for 2 hr, or barminomycin for 0.5 hr followed by a further 1.5 hr incubation with AN-9 using a 12,500-fold excess of AN-9 at each barminomycin concentration ( ), or AN-9 for 2 hr followed by a further 2 hr incubation with barminomycin (□).
[0123] [0123]FIG. 6 illustrates the schedule-dependent potentiation of adduct formation by AN-9.
[0124] [0124]FIG. 7 shows the effect of adding AN-9 many hours before Adriamycin, and also shows the effect of butyric acid.
[0125] [0125]FIG. 8 compares adduct formation by AN-9 and by aldehyde-releasing compounds which do not release formaldehyde.
[0126] [0126]FIG. 9 shows the concentration dependence of the effect of AN-9.
[0127] [0127]FIG. 10 shows the ability of hexamethylenetetramine to facilitate Adriamycin adducts.
[0128] [0128]FIG. 11 shows the stability of AN-9 induced Adriamycin adducts in cells.
[0129] [0129]FIG. 12 shows the sequence specificity of AN-9 induced Adriamycin-DNA adducts in cells.
[0130] [0130]FIG. 13 shows the binding of AN-9 induced Adriamycin adducts to RNA, DNA and protein.
DETAILED DESCRIPTION OF THE INVENTION
[0131] Before the present compounds, compositions, and methods are described, it is understood that this invention is not limited to the particular materials and methods described, as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims. It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a compound” includes compounds of similar formula and equivalents thereof known to those skilled in the art, and so forth. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any materials and methods similar or equivalent to those described herein can be used to practice or test the present invention, the preferred materials and methods are now described.
[0132] The methods and compounds of the invention are useful for enhancing the efficacy of chemotherapeutic agents such as, for example, anti-cancer agents like Adriamycin, daunomycin, idarubicin or epirubicin, or an anthracenedione such as mitoxantrone. Increased efficacy may be measured as an increase in bioavailability, increase in antiproliferative activity or decreased toxic side effect of the chemotherapeutic agent. By increasing bioavailability or antiproliferative activity or reducing toxic side effects associated with the use of chemotherapeutic agents, the invention satisfies some of the shortcomings of current therapeutic modalities.
[0133] The description that follows makes use of a number of terms used in pharmaceutical chemistry and cell biology. In order to provide a clear and consistent understanding of the specification and claims, including the scope given such terms, the following definitions are provided.
[0134] The term “endogenous” means originating within the subject, cell, or system being studied. Accordingly, supplementing the endogenous levels of aldehyde means that a compound or compounds is/are administered to a subject such that the total amount of aldehyde in the subject is higher than normally present. Increasing the endogenous levels of aldehyde means that a compound or compounds is/are administered to a subject where the compound or compounds increase the production of aldehyde by the subjects cells or tissue, thereby effectively increasing the total amount of aldehyde in the subject. The endogenous levels of aldehyde may also be effectively increased by decreasing the detoxification of aldehyde. For example, a compound or compounds of the invention when administered to a subject may decrease the rate of detoxification of endogenous aldehyde by inhibiting the effect of detoxifying agents.
[0135] The term “hydrocarbon” refers to alkyl, alkenyl or alkynyl groups as defined above in relation to the compounds of formula (I).
[0136] It will be appreciated by those skilled in the art that the compounds of the invention may be modified to provide pharmaceutically acceptable derivatives thereof at any of the functional groups in the compounds of formula (I).
[0137] The term “pharmaceutically acceptable derivative” means any pharmaceutically acceptable salt, ester or salt of such ester of a compound of formula (I) or any other compound which, upon administration to the recipient, is capable of providing a compound of formula (I) or a biologically active metabolite or residue thereof. Of particular interest as derivatives are compounds modified at the sialic acid carboxy or glycerol hydroxy groups, or at the amino and guanidino groups.
[0138] Pharmaceutically acceptable salts of the compounds of formula (I) include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acids include hydrochloric, hydrobromic, sulphuric, nitric, perchloric, fumaric, maleic, phosphoric, glycolic, lactic, salicylic, succinic, toluene-p-sulphonic, tartaric, acetic, citric, methanesulphonic, formic, benzoic, malonic, naphthalene-2-sulphonic and benzenesulphonic acids. Other acids such as oxalic acid, while not in themselves pharmaceutically acceptable, may be useful in the preparation of salts useful as intermediates in obtaining compounds of the invention and their pharmaceutically acceptable acid addition salts.
[0139] Salts derived from appropriate bases include alkali metal (eg. sodium), alkaline earth metal (eg. magnesium), ammonium, and NR 4 + (where R is C 1-4 alkyl) salts.
[0140] The term “toxic side effects” or “side effects” means the deleterious, unwanted effects of chemotherapy on the subject's normal, non-diseased tissues and organs. For example, toxic side effects may include bone marrow suppression (including neutropenia), cardiac toxicity, hair loss, gastrointestinal toxicity (including nausea and vomiting), neurotoxicity, lung toxicity and asthma.
[0141] The term “subject” as used herein refers to any animal having a disease or condition which requires treatment with a chemotherapeutic agent. The chemotherapeutic agent may also have bioavailability problems or causes toxic side effects. Preferably the subject is suffering from a cellular proliferative disorder (eg., a neoplastic disorder). Subjects for the purposes of the invention include, but are not limited to, mammals (eg., bovine, canine, equine, feline, porcine) and preferably humans.
[0142] By “cell proliferative disorder” is meant that a cell or cells demonstrate abnormal growth, typically aberrant growth, leading to a neoplasm, tumour or a cancer.
[0143] Cell proliferative disorders include, for example, cancers of the breast, lung, prostate, kidney, skin, neural, ovary, uterus, liver, pancreas, epithelial, gastric, intestinal, exocrine, endocrine, lymphatic, haematopoietic system or head and neck tissue.
[0144] Generally, neoplastic diseases are conditions in which abnormal proliferation of cells results in a mass of tissue called a neoplasm or tumour. Neoplasms have varying degrees of abnormalities in structure and behaviour. Some neoplasms are benign while others are malignant or cancerous. An effective treatment of neoplastic disease would be considered a valuable contribution to the search for cancer preventive or curative procedures.
[0145] The methods of this invention involve in one embodiment, (1) the administration of an aldehyde-releasing compound, prior to, together with, or subsequent to the administration of a chemotherapeutic agent; or (2) the administration of a combination of aldehyde-releasing compounds and a chemotherapeutic agent.
[0146] As used herein, the term “effective amount” is meant an amount of an aldehyde-releasing compound of the present invention effective to increase the efficacy of a chemotherapeutic agent in order to yield a desired therapeutic response. For example, to increase the efficacy of a chemotherapeutic agent by increasing bioavailability or by preventing or reducing the toxic side effects caused by the use of chemotherapeutic agents.
[0147] The term therapeutically-effective amount” means an amount of a chemotherapeutic agent to yield a desired therapeutic response. For example, treat or prevent a neoplastic disease.
[0148] The specific “therapeutically-effective amount” will, obviously, vary with such factors as the particular condition being treated, the physical condition of the subject, the type of animal being treated, the duration of the treatment, the nature of concurrent therapy (if any), and the specific formulations employed and the structure of the chemotherapeutic agent or its derivatives.
[0149] As used herein, a “pharmaceutical carrier” is a pharmaceutically-acceptable solvent, suspending agent or vehicle for delivering the aldehyde-releasing compound and/or chemotherapeutic agent to the animal or human. The carrier may be liquid or solid and is selected with the planned manner of administration in mind.
[0150] As used herein, “cancer” refers to all types of cancers or neoplasm or malignant tumours found in marnmals. Cancer includes sarcomas, lymphomas and other cancers. The following types are examples, but are not intended to be limited to these particular types of cancers: prostate, colon, rectal, breast, both the MX-1 and the MCF lines, pancreatic, neuroblastoma, rhabdomysarcoma, bone, lung, murine, melanoma, leukemia, pancreatic, melanoma, ovarian, brain, head & neck, kidney, mesothelioma, sarcoma, Kaposi's sarcoma, stomach, uterine and lymphoma.
[0151] As used herein the term “cell” includes but is not limited to mammalian cells (eg., mouse cells, rat cells or human cells).
[0152] The aldehyde-releasing compound and/or chemotherapeutic agents may be administered orally, topically, or parenterally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants, and vehicles. The term parenteral as used herein includes subcutaneous injections, aerosol, intravenous, intramuscular, intrathecal, intracranial, injection or infusion techniques.
[0153] The present invention also provides suitable topical, oral, and parenteral pharmaceutical formulations for use in the novel methods of treatment of the present invention. The compounds of the present invention may be administered orally as tablets, aqueous or oily suspensions, lozenges, troches, powders, granules, emulsions, capsules, syrups or elixirs. The composition for oral use may contain one or more agents selected from the group of sweetening agents, flavouring agents, colouring agents and preserving agents in order to produce pharmaceutically elegant and palatable preparations. The tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets.
[0154] These excipients may be, for example, (1) inert diluents, such as calcium carbonate, lactose, calcium phosphate or sodium phosphate; (2) granulating and disintegrating agents, such as corn starch or alginic acid; (3) binding agents, such as starch, gelatin or acacia; and (4) lubricating agents, such as magnesium stearate, stearic acid or talc. These tablets may be uncoated or coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. Coating may also be performed using techniques described in the U.S. Pat. Nos. 4,256,108; 4,160,452; and 4,265,874 to form osmotic therapeutic tablets for control release.
[0155] The aldehyde-releasing compounds as well as the chemotherapeutic agents useful in the methods of the invention can be administered, for in vivo application, parenterally by injection or by gradual perfusion over time independently or together. Administration may be intravenously, intra-arterial, intraperitoneally, intramuscularly, subcutaneously, intracavity, or transdermally. For in vitro studies the agents may be added or dissolved in an appropriate biologically acceptable buffer and added to a cell or tissue.
[0156] Preparations for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers (such as those based on Ringer's dextrose), and the like. Preservatives and other additives may also be present such as, for example, anti-microbials, anti-oxidants, chelating agents, growth factors and inert gases and the like.
[0157] It is envisioned that the invention can be used to increase the efficacy of chemotherapeutic agents used to treat cell proliferative disorders, including, for example, neoplasms, cancers (eg., cancers of the breast, lung, prostate, kidney, skin, neural, ovary, uterus, liver, pancreas, epithelial, gastric, intestinal, exocrine, endocrine, lymphatic, haematopoietic system or head and neck tissue), fibrotic disorders and the like.
[0158] The methods and compounds of the invention may also be used to increase the efficacy of chemotherapeutic agents used to treat other diseases such as neurodegenerative disorders, hormonal imbalance and the like.
[0159] Generally, the terms “treating”, “treatment” and the like are used herein to mean affecting a subject, tissue or cell to obtain a desired pharmacologic and/or physiologic effect. The effect may be prophylactic in terms of completely or partially preventing a disease or sign or symptom thereof, and/or may be therapeutic in terms of a partial or complete cure of a disease. “Treating” as used herein covers any treatment of, or prevention of a disease in a vertebrate, a mammal, particularly a human, and includes: (a) preventing the disease from occurring in a subject that may be predisposed to the disease, but has not yet been diagnosed as having it; (b) inhibiting the disease, ie., arresting its development; or (c) relieving or ameliorating the effects, ie., cause regression of the effects of the disease.
[0160] The invention includes various pharmaceutical compositions useful for treating a disease. The pharmaceutical compositions according to one embodiment of the invention are prepared by bringing an aldehyde-releasing compound, analogue, derivative or salt thereof and one or more chemotherapeutic agents into a form suitable for administration to a subject using carriers, excipients and additives or auxiliaries. Frequently used carriers or auxiliaries include magnesium carbonate, titanium dioxide, lactose, mannitol and other sugars, talc, milk protein, gelatin, starch, vitamins, cellulose and its derivatives, animal and vegetable oils, polyethylene glycols and solvents, such as sterile water, alcohols, glycerol and polyhydric alcohols. Intravenous vehicles include fluid and nutrient replenishers. Preservatives include antimicrobial, anti-oxidants, chelating agents and inert gases. Other pharmaceutically acceptable carriers include aqueous solutions, non-toxic excipients, including salts, preservatives, buffers and the like, as described, for instance, in Remington's, 1975, and The National Formulary, 1975, the contents of which are hereby incorporated by reference. The pH and exact concentration of the various components of the pharmaceutical composition are adjusted according to routine skills in the art—see Goodman and Gilman.
[0161] The pharmaceutical compositions are preferably prepared and administered in dose units. Solid dose units are tablets, capsules and suppositories. For treatment of a subject, depending on activity of the chemotherapeutic agent, manner of administration, nature and severity of the disorder, age and body weight of the subject, different daily doses can be used. Under certain circumstances, however, higher or lower daily doses may be appropriate. The administration of the daily dose can be carried out both by single administration in the form of an individual dose unit or else several smaller dose units and also by multiple administration of subdivided doses at specific intervals.
[0162] The pharmaceutical compositions according to the invention may be administered locally or systemically in a therapeutically effective dose. Amounts effective for this use will, of course, depend on the severity of the disease and the weight and general state of the subject. Typically, dosages used in vitro may provide useful guidance in the amounts useful for in situ administration of the pharmaceutical composition, and animal models may be used to determine effective dosages for treatment of particular disease. Various considerations are described, eg. in Langer, 1990. Formulations for oral use may be in the form of hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin. They may also be in the form of soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, such as peanut oil, liquid paraffin or olive oil.
[0163] Aqueous suspensions normally contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspension. Such excipients may be (1) suspending agent such as sodium carboxymethyl cellulose, methyl cellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; (2) dispersing or wetting agents which may be (a) naturally occurring phosphatide such as lecithin; (b) a condensation product of an alkylene oxide with a fatty acid, for example, polyoxyethylene stearate; (c) a condensation product of ethylene oxide with a long chain aliphatic alcohol, for example, heptadecaethylenoxycetanol; (d) a condensation product of ethylene oxide with a partial ester derived from a fatty acid and hexitol such as polyoxyethylene sorbitol monooleate, or (e) a condensation product of ethylene oxide with a partial ester derived from fatty acids and hexitol anhydrides, for example polyoxyethylene sorbitan monooleate.
[0164] The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to known methods using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono-or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.
[0165] Aldehyde-releasing compounds may also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles, and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine, or phosphatidylcholines.
[0166] Dosage levels of the aldehyde-releasing compounds of the present invention are of the order of about 0.5 mg to about 20 mg per kilogram body weight, with a preferred dosage range between about 5 mg to about 20 mg per kilogram body weight per day (from about 0.3 g to about 3 g per patient per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage will vary depending upon the host treated and the particular mode of administration. For example, a formulation intended for oral administration to humans may contain about 5 mg to 1 g of an active compound with an appropriate and convenient amount of carrier material which may vary from about 5 to 95 percent of the total composition. Dosage unit forms will generally contain between from about 5 mg to 500 mg of active ingredient.
[0167] It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, chemotherapeutic agent combination and the severity of the particular disease undergoing therapy.
[0168] In addition, some of the compounds of the instant invention may form solvates with water or common organic solvents. Such solvates are encompassed within the scope of the invention.
[0169] The compounds of the present invention may additionally be combined with other compounds to provide an operative combination. It is intended to include any chemically compatible combination of chemotherapeutic agents or aldehyde-releasing compound, as long as the combination does not eliminate the ability of the aldehyde-releasing compound of this invention to increase efficacy of the chemotherapeutic agents.
[0170] The invention will now be further described by way of reference only to the following non-limiting examples. It should be understood, however, that the examples following are illustrative only, and should not be taken in any way as a restriction on the generality of the invention described above. In particular, while the invention is described in detail in relation to cancer, it will be clearly understood that the findings herein are not limited to treatment of cancer. For example, aldehyde-releasing compounds may be used in combination with chemotherapeutic agents used in the treatment of other diseases.
EXAMPLE 1
Synergism Between Adriamycin and AN-9 in IMR-32 and PC-3 Cells
[0171] Previous data had suggested that there was a synergistic interaction between various anthracyclines and AN-9 in producing a cytotoxic response in mouse Mm-A cells (Kasukabe et al., 1997). In order to test the synergistic relationship between Adriamycin and AN-9 in human cells, cytotoxicity studies were performed in human neuroblastoma and prostate adenocarcinoma cells in culture.
[0172] IMR-32 human neuroblastoma and PC-3 prostate adenocarcinoma cells (100 μL at a density of 5×10 4 cells/mL) were seeded in tissue culture 96 well plates (in triplicate) for 48 hr. They were exposed to different concentrations of the drugs at the specified ratio and times. Viability was determined by neutral-red assay as described by Kopf-Maier and Kolon (1992). The mean value obtained from 3 wells was calculated, and IC 50 values were derived from non-linear regression of the adjusted Y (% control viability) values against the log concentration of the compounds. Combination Index (CI) values were evaluated according to the classical isobologram equation:
CI =( D )( Dx ), +( D ) 2 /( Dx ) 2
[0173] where Dx is the dose of one compound alone required to produce an effect, and (D) 1 and (D) 2 are the doses of both compounds that produce the same effect. From this analysis the combined effects of two compounds can be assessed as either additive (or zero) interaction indicated by CI=1, synergistic interaction as indicated by CI<1, or antagonistic interaction as indicated by CI>1. The results are shown in Table 1.
TABLE 1 CI Order of addition AN-9:Adr IMR-32 PC-3 simultaneous 25:1 0.25 0.88 simultaneous 50:1 0.41 0.61 (AN-9)-1 25:1 2.5 2.0 (AN-9)-1 50:1 2.0 1.66 Adr-1 25:1 0.56 0.62 Adr-1 50:1 0.88 0.49
[0174] Compounds were added to cells simultaneously at ratios of AN-9:Adr of 25:1 and 50:1. The combination exhibited synergy using both ratios. In contrast, when AN-9 was added 16 hr prior to Adriamycin (AN-9-1), antagonism was observed. However, good synergy was maintained when Adriamycin was added 16 hr prior to AN-9 (Adr-1). These results were significant, since they implied a mechanism of cytotoxicity which was highly dependent on a defined sequence of interactions between the two drugs.
EXAMPLE 2
Formation of DNA Adducts in IMR-32 (Human Neuroblastoma) and MCF-7 (Human Breast Adenocarcinoma) Cells in the Presence of AN-9 and Adriamycin
[0175] We sought to investigate the level of DNA adducts formed under various treatment conditions, since we speculated that the peculiar effectiveness of the Adriamycin/AN-9 combination might be due to increased levels of DNA damage in the form of DNA adducts. IMR-32 human neuroblastoma cells (A and B) and MCF-7 human breast adenocarcinoma cells (C and D) were treated with Adriamycin for 2 hr (0-10M as shown) followed by a further 2 hr incubation with a 25-fold excess of AN-9 (▪), or treated with AN-9 for 2 hr followed by a further 4 hr incubation with Adriamycin (□). Genomic DNA was isolated using mild conditions (Cutts et al., 2001) and subjected to gene-specific Southern hybridisation analysis. For detection of the mitochondrial genome, DNA was restriction digested with BamHI, and unreacted or intercalated drug was removed by phenol/chloroform extraction and ethanol precipitation. Samples were resuspended in 60% formamide and heat denatured at 60° C. for 5 min. Samples were resolved electrophoretically through 0.8% agarose, transferred to nylon membranes and probed with mitochondrial RNA. The percentage of double stranded DNA was calculated by phosphorimage analysis; this correlates with adduct formation in the mitochondrial genome (A and C), since the adducts behave functionally as virtual interstrand crosslinks (Zeman et al., 1998; Cullinane et al., 2000). For detection of the DHFR gene, DNA was digested with HindIII and processed as described above; however, randomly primed DHFR DNA was used as the probe for Southern analysis (B and D). Data were derived from each of two separate blots of two biological experiments, and the values are represented as the mean±SE. The results, summarised in FIG. 1, showed dramatic increases in the level of DNA adducts in the presence of AN-9, compared to Adriamycin alone where no adducts were detected. This clearly showed a direct damage mechanism which could result in the synergy displayed by the combination of Adriamycin and AN-9. It is significant that when AN-9 was added after Adriamycin, greatly enhanced levels of adducts were obtained compared to when it was added prior to Adriamycin. This provides a biochemical basis for the synergistic/antagonistic cytotoxicity relationship.
EXAMPLE 3
Reaction Time Dependence of AN-9 Facilitated Adriamycin Adducts
[0176] Since adducts had been demonstrated to be induced by the Adriamycin/AN-9 combination, a greater understanding of the mechanism of adduct formation was needed. It was known that the formation of Adriamycin adducts was highly time-dependent. To confirm that the adducts behave as classical Adriamycin adducts, and also to investigate the optimal conditions for adduct formation, a time course study was initiated. IMR-32 cells were treated with a combination of 4 μM Adriamycin and 100 μM AN-9 for 0-8 hr as described above. Phosphorimage analysis was used to quantitate the time-dependent formation of adducts in the mitochondrial genome (A) and DHFR gene (B). The results, presented in FIG. 2, show that adduct formation reached a plateau between 4 and 8 hr, similar to that previously shown for Adriamycin alone (Cullinane et al., 2000).
EXAMPLE 4
Conditions for Synergistic Adduct Formation
[0177] In order to gain some understanding as to why synergy was greatest when AN-9 was added at the same time as, or after, Adriamycin, a time course of addition of AN-9 was studied. IMR-32 cells were exposed to 4 μM Adriamycin for 4 hr. However, in this experiment 100 μM AN-9 was added at varying times, ranging from 2 hr prior to Adriamycin addition (designated as −2) to 2 hr after Adriamycin addition. Genomic DNA was extracted from the cells and then processed for Southern analysis. Adduct/crosslinking levels are shown in FIG. 3 for both mitochondrial (A) and nuclear (B) DNA, using probes for mtDNA and the DHFR gene respectively. Phosphorimage analysis was used to quantitate the fraction of DS DNA, a measure of adduct formation, for each treatment condition. Adduct formation fluctuated greatly, and depended on a relatively small time frame within which AN-9 was added to cells. Specifically, greatly enhanced levels of adducts were obtained when AN-9 was added shortly after Adriamycin, and this resulted in even higher adduct levels than when the drugs were added simultaneously. This enabled us to predict that if AN-9 was added shortly after Adriamycin in cytotoxicity assays, within say approximately 2 hr, then the Combination Index obtained would be even better than when the drugs were added simultaneously.
EXAMPLE 5
Conditions Which Antagonise Adduct Formation
[0178] To extend the analysis of the effect of the relative timing of addition of AN-9 on adduct levels, a more detailed analysis was initiated. This study was designed to include early times of addition of AN-9, so that the levels of adducts could be established where the combination exhibits antagonism as judged by cytotoxicity assays (Table 1).
[0179] IMR-32 cells were exposed to Adriamycin (6 μm) for 4 hr, and AN-9 (125 μM) was added at varying times from 24 hr prior to Adriamycin addition (−24) to 2 hr after Adriamycin. Genomic DNA was extracted from cells and then processed for Southern analysis. Phosphorimage analysis was used for quantitation of the adducts in mtDNA (A) and the DHFR gene (B), and the results are shown in FIG. 4.
[0180] These results clearly showed that there was no enhancement of adduct levels when AN-9 was administered 5-24 hr prior to Adriamycin, but that detectable levels of adducts were observed when AN-9 was administered approximately 5 hr prior to Adriamycin, and adduct levels increased until AN-9 was administered 2 hr after Adriamycin; administration of AN-9 2 hr after Adriamycin was established in Example 4 to be optimal for adduct formation. This information enabled us to predict the best time of drug addition to obtain high levels of adducts.
EXAMPLE 6
Effect of AN-90N Barminomycin-Induced Crosslinks
[0181] AN-9 releases three components, pivalic acid, butyric acid (BA) and formaldehyde, when it is hydrolysed by intracellular esterases. The enhanced reaction of Adriamycin with DNA could therefore be catalysed by one or more of these components. Butyric acid released by AN-9 is likely to lead to increased adduct formation by Adriamycin, since the expression of BA causes accumulation of multi-acetylated forms of histones H3 and H4, leading to an alteration of chromatin structure (Vidali et al., 1978).
[0182] This altered chromatin structure is more sensitive to DNase I, and is a favourable configuration for transcription, and as a consequence gene regulation is altered at this level. This is accompanied by an increased accessibility to DNA by agents such as acridine orange and actinomycin D (Darzynkiewicz et al., 1969), and probably also for the intercalating agent Adriamycin. AN-9 has been shown to induce histone acetylation in HL-60 cells, presumably due to the release of BA, and this effect is transient since the basal level of acetylation is re-established 6 hr after the exposure to AN-9 (Aviram et al., 1994). We speculated that butyric acid could well lead to increased Adriamycin adduct formation, since early studies suggested that butyric acid and Adriamycin were synergistic in mouse neuroblastoma cells (Prasad, 1979), although more recent data provides little support for this notion (Kasukabe et al., 1997). Alternatively, the formaldehyde released by AN-9 could play a direct role in the increased adduct formation. Formaldehyde is one of the reagents known to lead to increased formation of Adriamycin adducts in naked plasmid and synthetic DNA, and is capable of being incorporated into the Adriamycin adduct.
[0183] In order to test whether formaldehyde or other components are important in the mechanism of enhanced adduct formation by AN-9, an anthracycline related to Adriamycin was used. This anthracycline, barminomycin, is capable of adduct formation in the absence of formaldehyde, ie it does not require activation for the formation of adducts with DNA.
[0184] IMR-32 cells were treated with barminomycin alone (0-20 nM, ▪) for 2 hr, or barminomycin for 0.5 hr followed by a further 1.5 hr incubation with AN-9 using a 12,500-fold excess of AN-9 at each barminomycin concentration (), or AN-9 for 2 hr followed by a further 2 hr incubation with barminomycin (□). Samples were treated as described above. Phosphorimage quantitation was used to generate results for the mitochondrial genome (A) and the DHFR gene (B). These results, illustrated in FIG. 5, demonstrated that AN-9 had no effect on the ability of barminomycin to induce DNA crosslinks, and indicate that barminomycin does not require formaldehyde to form adducts with DNA because it is essentially a “formaldehyde-activated” anthracycline (Perrin et al., 1999). This clearly distinguished barminomycin from Adriamycin, and implied that the mechanism of enhancement of formation of Adriamycin adducts by AN-9 involved activation by formaldehyde.
EXAMPLE 7
Incorporation of [ 14 C] Adriamycin Into Adducts
[0185] [ 14 C]-labelled Adriamycin was used to confirm that the adducts formed in the presence of AN-9 actually contained the Adriamycin chromophore, and also to accurately estimate the levels of adducts induced in the various treatment schedules.
[0186] IMR-32 cells were seeded into 3.5 cm petri dishes at a density of 7.5×10 5 cells/dish 24 hr prior to exposure to 41M [ 14 C]-Adriamycin for 4 hr. In other treatments 100 μM AN-9 was added at varying times: 2 hr prior to Adriamycin addition (−2); simultaneously (O); and 2 hr after Adriamycin (2). Cells were harvested, and the genomic DNA was isolated. Samples were then extracted twice with phenol and once with chloroform, and DNA was selectively precipitated from RNA by ammonium acetate precipitation. DNA pellets were resuspended in 100 μL TE buffer, and the concentration determined spectrophotometically at 260 nm. Aliquots of the genomic DNA (50 μL) were each added to 1 mL of Optiphase Hisafe scintillation cocktail, and the incorporation of [ 14 C]-labelled drug into the DNA was monitored using a Wallac 1410 Liquid Scintillation Counter.
[0187] As shown in FIG. 6, the level of Adriamycin adducts in the absence of AN-9 was approximately 1.5 per 10 kb, and 3.5 per 10 kb for the 2 hr AN-9 pretreatment. When AN-9 and Adriamycin were administered simultaneously there were approximately 12 adducts per 10 kb but 24 per 10 kb when AN-9 was administered 2 hr after Adriamycin. This therefore confirmed the schedule-dependent enhancement of adducts by AN-9, and showed that the level of Adriamycin adducts could be potentiated by up to 15-fold in the presence of AN-9 under these conditions. This experiment also shows that Adriamycin alone produces low levels of adducts, even though it reportedly catalyses the cellular production of formaldehyde (Kato et al., 2000). Therefore the formaldehyde produced by Adriamycin is not sufficient to induce high levels of adducts. This may be due to a number of factors, such as inefficient subcellular localization of this pool of formaldehyde, low levels of formaldehyde production, and production of formaldehyde at inappropriate times.
EXAMPLE 8
[ 14 C] Adducts Induced by AN-9 Compared to Control Compounds
[0188] It was necessary to compare the levels of adducts formed when AN-9 was added many hours prior to Adriamycin to those formed in the presence of Adriamycin alone, as it was under these conditions that the combination exhibited cytotoxic antagonism. It was also necessary to use various control compounds to further identify the components which were most responsible for enhanced adduct formation.
[0189] IMR-32 cells were exposed to 6 μM [ 14 C]-Adriamycin alone (Adr) for 4 hr, or together with 125 μl AN-9 at varying times: 16 hr prior (−16), 2 hr prior (−2), simultaneously (0), and 2 hr after Adriamycin addition (2). The remaining treatments were Adriamycin with 0.5% DMSO (DM), 250 μM AN-158 (158) (which releases BA and acetaldehyde upon hydrolysis), or with sodium butyrate (1 mM) at varying times: 16 hr prior (b-16), 2 hr prior (b-2), simultaneously (b), and 2 hr after Adriamycin (b+2). Genomic DNA was extracted from the cells, and incorporation of radiolabelled drug was determined by scintillation counting to determine the level of [ 14 C] adducts per 10 kb. The results are shown in FIG. 7.
[0190] Significantly, the levels of Adriamycin adducts were diminished when AN-9 was added 16 hr prior to Adriamycin (1.7/10 kb) compared to using Adriamycin alone (2.8/10 kb). This represented a 40% loss of adducts, therefore explaining why the AN-9 treatment under these conditions would have been less effective. In contrast, there was an approximately 20-fold enhancement compared to Adriamycin alone when AN-9 was added 2 hr after Adriamycin. The control results showed that the DMSO vehicle in which AN-9 was dissolved did not contribute to adduct formation. Butyric acid was used as a control under various conditions to test directly whether adduct formation could be increased by the exposure of cells to this agent. However, there were no significant increases in adduct levels under any of the treatment conditions.
EXAMPLE 9
[ 14 C] Adduct Formation Induced by a Series of Aldehyde-Releasing Compounds Related to AN-9
[0191] In order to test whether formaldehyde-releasing drugs other than AN-9 were efficient at facilitating Adriamycin adducts, a series of aldehyde-releasing compounds was assessed. The structures of these aldehyde-releasing compounds and the hydrolysis products which they release are summarised in Table 2.
TABLE 2 NMR(CDCl 3 ) ppm COMPOUNDS NAME STRUCTURE PRODUCTS Spectra AN-9 Pivaloyloxymethyl Butyrate 1) Butyric Acid 2) Formaldehyde 3) Pivalic Acid 0.92(t, MeCH 2 , 3H), 1.16(s, t-Bu, 9H), 1.45 (d, MeCH, 3H), 1.67(sext, MeCH 2 , 2H), 2.3 (t, CH 2 CO, 2H), 6.86(q, OCH 2 O). AN-1 Butyroyloxymethyl Butyrate 1) 2 eq Butyric Acid 2) Formaldehyde 0.95(t, Me, 3H), 1.63(sext, CH 2 Me, 4H), 2.33 (t, CH 2 CO, 4H), 5.78(s, OCH 2 O, 2H). AN-11 Ethylidene Dibutyrate 1) 2 eq Butyric Acid 2) Acetaldehyde 0.95(t, Me, 3H), 1.47(d, MeCH, 3H), 1.65 (sext, CH 2 Me, 4H), 2.3(t, CH 2 CO, 4H), 6.66 (q, CH, 1H). AN-7 Butyroyloxymethyldiethyl Phosphate 1) Butyric Acid 2) Formaldehyde 3) Phosphoric Acid 4) Ethanol 5.63(d, 2H, OCH 2 O), 4.13(d quint, 4H, two CH 2 OP), 2.36(t, 2H, COCH 2 ), 1.69 (sext, 2H, CH 2 CH 2 CO), 1.34 (td, 6H, two MeCH 2 O), 0.96 (t, 3H, Me). AN-88 1-Butyroyloxyethyldiethyl Phosphate 1) Butyric Acid 2) Acetaldehyde 3) Phosphoric Acid 4) Ethanol 6.47(dq, 1H, CHMe), 4.08 (ddquint, 4H, two CH 2 OP), 2.28 (t, 2H, COCH 2 ), 1.62(sext, 2H, CH 2 CH 2 CO), 1.49 (d, 3H, CHMe), 1.29(tdd, 6H, two MeCH 2 O), 0.91(t, 3H, Me) AN-158 1-Pivaloyloxyethyl Butyrate 1) Butyric Acid 2) Acetaldehyde 3) Pivalic Acid 0.95(t, MeCH 2 , 3H), 1.2(s, t-Bu, 9H), 1.45 (d, MeCH, 3H), 1.63(sext, CH 2 Me, 2H), 2.3 (t, CH 2 CO), 6.84 (q, CH, 1H). AN-184 1-Propionylyloxyethyl Pivalate 1) Propionic Acid 2) Acetaldehyde 3) Pivalic Acid 1.12(t, Me, 3H), 1.2(s, CMe 3 , 9H), 1.45 (d, Me, 1), 2.32 (q, CH 2 CO, 2H), 6.85(q, OCH 2 O, 1H). AN-185 1-Isobutyroylyloxyethyl Pivalate 1) Isobutyric Acid 2) Acetaldehyde 3) Pivalic Acid 1.2(d, Me 1 , 3H), 1.21(d, Me 2 , 3H), 1.23 (s, CMe 3 , 9H), 1.5(d, MeCH, 3H), 2.54(sept, CHCO 2 , 1H), 6.83 (q, CH, 1H). AN-36 Propionyloxymethyl Pivalate 1) Propionic Acid 2) Formaldehyde 3) Pivalic Acid 1.15(t, Me, 3H), 1.2(s, t-Bu, 9H), 2.37 (q, CH 2 CO 2 , 2H), 5.76(s, OCH 2 O, 2H). AN-38 Valeroyloxymethyl Pivalate 1) Pentanoic Acid 2) Formaldehyde 3) Pivalic Acid 0.88(t, Me, 3H), 1.22(s, t-Bu, 9H), 1.35 (sext, CH 2 Me, 2H), 1.62 (quint, CH 2 CH 2 Me, 2H), 2.33(t, CH 2 CO 2 , 2H), 5.73(s, OCH 2 O, 2H) AN-37 Isobutyroyloxymethyl Pivalate 1) Isobutyric Acid 2) Formaldehyde 3) Pivalic Acid 1.18(d, Me, 6H), 1.22(s, t-Bu, 9H), 2.6 (sept, CH, 1H), 5.77(s, OCH 2 O, 2H). AN-188 Ethylidene Dipropionate 1) Propionic Acid 2) Acetaldehyde 3) Propionic Acid 1.15(t, Me, 3H), 1.47(d, MeCH, 3H), 2.3 (t, CH 2 CO, 4H), 6.66(q, CH, 1H). AN-190 Oxalic acid bis-(2,2-dimethylpropionyloxymethyl)ester 1) 2 eq Pivalic Acid 2) Oxalic Acid 3) 2 eq Formaldehyde 1.22(s, 9H, t-Bu), 5.7(s, 2H, CH 2 ). AN-192 Succinic acid bis-(2-2-dimethylpropionyloxymethyl)ester 4) 2 eq Pivalic Acid 5) Succinic Acid 6) 2 eq Formaldehyde 1.23(s, t-Bu, 18H), 2.68(s, CH 2 CH 2 , 4H), 5.75(s, OCH 2 O, 4H). AN-193 Succinic acid dibutyryloxymethyl ester 7) 2 eq Butyric Acid 8) Succinic Acid 9) 2 eq Formaldehyde 0.95(t, Me, 9H), 1.64 (sext, MeCH 2 , 4H), 2.34(t, CH 2 CO, 4H), 2.67 (s, CH 2 CH 2 , 4H), 5.76(s, OCH 2 O, 4H). AN-194 Oxalic acid dibutyryloxymethyl ester 10) 2 eq Butyric Acid 11) Oxalic Acid 12) 2 eq Formaldehyde 0.96(t, Me, 3H), 1.7(sext, CH 2 Me, 2H), 2.38 (t, CH 2 CO, 2H), 5.92(s, OCH 2 O, 2H). AN-189 Oxalic acid bis-(1-butyryloxy-ethyl)ester 1) 2 eq Butyric Acid 2) Oxalic Acid 3) 2 eq Acetaldehyde 0.96(t, Me, 3H), 1.58(d, MeCH, 3H), 1.65 (sext, CH 2 , 2H), 2.34(t, CH 2 , 2H), 6.95(qd, CH, 1H). AN-191 Succinic acid bis-(1-butyryloxy-ethyl)ester 1) 2 eq Butyric Acid 2) Succinic Acid 3) 2 eq Acetaldehyde 0.92(t, Me, 6H), 1.43(d, Me, 6H), 1.6 (sext, CH 2 , 4H), 2.3(t, CH 2 , 4H), 2.6(s, CH 2 CH 2 , 4H), 6.8 (q, OCHO, 2H).
[0192] There was a possibility that only AN-9 possessed the unique ability to contribute to adduct formation. This would be apparent if intact AN-9, ie. AN-9 prior to the esterase-dependent release of products, facilitated crosslink formation. It was also possible that no other compound was as efficient as AN-9 at releasing the formaldehyde needed for adduct formation. Therefore, IMR-32 cells were treated with 4 μM [ 14 C] Adriamycin and were simultaneously treated with 100 μM of selected aldehyde-releasing compound. Cells were harvested, genomic DNA was extracted and scintillation analyses were performed as described above. The results are shown in FIG. 8.
[0193] Significantly, only the formaldehyde-releasing drugs AN-9, AN-7, AN-37, and AN-38 enhanced adduct levels compared to levels obtained in the presence of Adriamycin (ADR) alone. However, the enhancement varied dramatically depending on the aldehyde-releasing compound employed.
[0194] AN-9 and AN-38 were the most effective compounds, and exhibited equivalent levels of activation. They are very similar in structure, and therefore may localize similarly in subcellular compartments, and be hydrolysed to constitutive products with similar efficiency. AN-7 and AN-37 also exhibited good activity, but were not as effective as AN-9 and AN-38. This could be due to one or more of a number of factors, such as
[0195] 1) different rates of hydrolysis;
[0196] 2) differences in subcellular localization and/or cell uptake; and
[0197] 3) interference with adduct formation by other hydrolysis products such as isobutyric acid.
[0198] When the control aldehyde-releasing compound AN-158 was used, there was no enhancement of adduct formation. This drug is almost identical to AN-9, in that it releases butyric acid and pivalic acid; however, it releases acetaldehyde rather than formaldehyde. These data therefore provide clear evidence that the formaldehyde component of AN-9 contributed significantly to adduct formation.
[0199] Other control acetaldehyde-releasing prodrugs which were used (AN-88 and AN-188) also reinforced the concept that it was the released formaldehyde which was solely responsible for increased adduct formation.
EXAMPLE 10
[ 14 C] Adriamycin Adducts Obtained with Increasing Concentrations of AN-9
[0200] To test whether a greater fraction of Adriamycin can be utilized for adduct formation when the amount of available formaldehyde is increased, the concentration dependence of AN-9 was investigated. IMR-32 cells were treated with [ 14 C] Adriamycin at a constant concentration of 4 μM. AN-9 was added 2 hr after Adriamycin at concentrations ranging from 4 μM (1:1) to 500 μM (1:125), and the treatment continued for a further 2 hr. Cells were harvested, DNA was extracted and samples were analysed for incorporation of [ 14 C]. The results are shown in FIG. 9.
[0201] At low levels of Adriamycin:AN9, (1:1-1:5), the enhancement of adduct formation was poor, but at higher concentrations there was a near linear relationship between AN-9 concentration and Adriamycin adducts. Significantly, the ratio of Adriamycin:AN-9 routinely employed in experiments is 1:20-1:25, and in this experiment yielded 10 adducts per 10 kb. However, at 500 μM AN-9 (1:125) adduct levels were approximately 10 fold higher. This represents an approximately 100-fold potentiation of Adriamycin adduct levels in the presence of AN-9.
[0202] It is therefore evident that by modulating the level of AN-9, the level of adducts can be enhanced by high aldehyde-releasing compound:chemotherapeutic agent ratios. This is a particularly significant finding, as it implies that very low concentrations of Adriamycin can be employed for adduct formation if high levels of formaldehyde are available. At 500 μM AN-9, approximately 5% of the total Adriamycin added to cells was incorporated into DNA adducts. Since saturation (ie, a plateau) was not observed, this percentage can probably be expected to be further enhanced. Furthermore, since Adriamycin adducts are unstable, with a half-life of (Phillips and Cullinane, 1999) 5-40 hr, the actual level of adducts in the undisturbed cellular environment is presumed to be higher than quantitated in these experiments.
EXAMPLE 11
Reversal of Formaldehyde-Mediated Effects by Semi-Carbazide
[0203] Since formaldehyde has been shown to be a critical element in the formation of DNA adducts, it was important to establish if these adducts were responsible for the enhanced cytotoxicity displayed by the Adriamycin/AN-9 combination. Formaldehyde was sequestered by the addition of high concentrations of semi-carbazide (sc). The results of this study are shown in Table 3.
TABLE 3 Adducts Relative Treatment (lesions/10 kb) survival Adriamycin 0.7 ± 0.01 1.00 ± 0.12 Adriamycin + AN-9 11.0 ± 0.5 0.35 ± 0.06 Adriamycin + AN-9 + sc (250 μM) 6.2 ± 1.1 0.37 ± 0.11 (6.7 ± 0.6) Adriamycin + AN-9 + sc (500 μM) 4.9 ± 1.0 0.71 ± 0.08 (4.6 ± 0.2) Adriamycin + AN-9 + sc (1 mM) 3.9 ± 0.3 0.88 ± 0.22 (3.2 ± 0.2) Adriamycin + sc (1 mM) 0.7 ± 0.01 1.2 ± 0.16
[0204] Adducts (lesions/10 kb) were determined by incubating IMR-32 cells in the presence of 2 μM [ 14 C]Adriamycin for 2 hr. followed by an additional 2 hr in the presence or absence of 100 μM AN-9. Semi-carbazide addition was at the same time as Adriamycin (ie 2 hr before AN-9). However, values in parentheses indicate that semi-carbazide addition was at the same time as AN-9 treatment (ie 2 hr after Adriamycin). As expected, the level of DNA adducts was dramatically reduced by incubation of cells with increasing ratios of semi-carbazide. Little difference was observed between adding semi-carbazide at the same time as Adriamycin or at the same time as AN-9 (2 hr later).
[0205] Cell viability assays were used to measure the effect of semi-carbazide inclusion on the interaction displayed by the Adriamycin/AN-9 combination. To obtain data representing relative survival, cells were seeded at a density of 1×10 4 per well and exposed to increasing concentrations of Adriamycin in the presence or absence of 50 μM AN-9 and/or semi-carbazide (0.25, 0.5 or 1.0 mM as indicated) for 72 hr. IC 50 values for various combinations are shown as relative survival compared to Adriamycin alone. Incubation of Adriamycin and AN-9 with increasing concentrations of semi-carbazide resulted in increasing levels of protection from the drug combination and at the highest semi-carbazide concentration (1 mM) cell viability was similar to that displayed by Adriamycin alone. Overall, the critical role of formaldehyde was confirmed by reversal of formaldehyde-mediated effects by semi-carbazide, which reduced adduct formation and also abolished the cytotoxicity resulting from the interaction of AN-9 with Adriamycin. It is therefore clear that the formation of adducts is at least in part associated with (or responsible for) the synergy displayed by the AN-9/Adriamycin combination.
EXAMPLE 12
The Ability of Hexamethylenetetramine to Facilitate Adriamycin Adducts
[0206] IMR-32 (1×10 6 ) cells were seeded into 10 cm petri dishes and allowed to attach overnight. Cells were then treated with 15 μM Adriamycin and 4 hr later with 0-2.5 mM hexamethylenetetramine (see structure below). Cells were harvested after 8 hr and the DNA extracted using a modified procedure of a QIAamp DNA Blood Mini Kit (QIAGEN), restriction digested and separated electrophoretically on a 0.5% agarose gel (Cutts et al, 2001). The gel was transferred to a nitrocellulose membrane and Southern hybridisation was used to indicate the nuclear DHFR gene and the mitochondrial genome. The virtual crosslinks were calculated as lesions per 10 kb and are shown in FIG. 10 at each hexamethylenetetramine concentration for nuclear DNA (▪) and mt DNA(). Virtual crosslinks were not detected with Adriamycin treatment or hexamethylenetetramine treatment as single compounds. The overall levels of lesions are approximately 60-fold lower than that detected by the [ 14 C] binding assay, due mainly to the loss of adducts using the harsher Southern hybridisation technique (Cutts et al., 2001). These results demonstrate that formaldehyde-releasing compounds (other than the specific aldehyde-releasing compounds examined) have the ability to facilitate adduct formation. However, hexamethylenetetramine is not as effective as AN-9 and similar aldehyde-releasing compounds and this is probably due to the slow release of formaldehyde by hexamethylenetetramine which is favoured under conditions of low pH, as opposed to the rapid hydrolysis of aldehyde-releasing compounds by esterases.
[0207] Structure of Hexamethylenetetramine
EXAMPLE 13
Stability of AN-9 Induced Adriamycin Adducts in Cells
[0208] In order to determine the stability of AN-9 induced DNA adducts we performed the following experiment. We seeded IMR-32 cells at a density of 2.5×10 6 cells per 10 cm petri dish. The following day cells were pretreated with 4 μM [ 14 C] Adriamycin for 2 hr and then treated with 260 μM AN-9 for a further 2 hr. Cells were harvested and genomic DNA was isolated using a modified QIAamp procedure. Residual intercalated Adriamycin was removed by two phenol extractions, one chloroform extraction and ethanol precipitation. Samples were exposed to various times of standing at 37° C. or varying temperatures, and unbound drug was removed by a further phenol/chloroform extraction. Residual [ 14 C] Adriamycin-DNA adducts were assessed by scintillation counting. To confirm that the DNA adducts induced in cells by AN-9 were the same as those produced in vitro, [ 14 C] Adriamycin was also used to form adducts under different conditions in cell free systems. This allowed the fate of the Adriamycin chromophore to be assessed in response to elevated temperature and extended times at 37° C. The results of this study are shown in FIG. 11. Specifically, the conditions for formation of adducts were formaldehyde-facilitated adducts in vitro (1), AN-9/esterase facilitated adducts in vitro (!) and Adriamycin/AN-9 induced adducts in cells (+). Adducts purified from the three different environments all showed similar temperature lability and adduct-DNA dissociation rates, indicating that the adducts in cells are most likely of identical structure to those produced in cell free systems. Specifically, the melting temperature (Tm) of formaldehyde-mediated adducts in vitro was 72.2±1.6° C., with a half life at 37° C. of 33.2±2.7 hr. AN-9/esterase-mediated adducts in vitro had a Tm of 74.3±3.5° C. and a half-life of 31.7±4.4 hr while Adriamycin adducts formed in cells in the presence of AN-9 had a Tm of 75.1±0.4° C. and a half-life of 34.0±3.0 hr.
EXAMPLE 14
Sequence Specificity of AN-9 Induced Adriamycin-DNA Adducts in Cells
[0209] IMR-32 cells were seeded at a density of 1.5×10 6 cells per 10 cm petri dish and allowed to attach overnight. Cells were treated with 4 μM Adriamycin and 500 μM AN-9 for a total of 4 hr (the AN-9 was added 2 hr after Adriamycin) then harvested and washed twice with PBS. Total genomic DNA was extracted using a modified QIAamp procedure. Genomic DNA was restriction digested with EcoRI to isolate a 340 bp alpha satellite repeat. DNA fragments were 3′ end-labelled with [ 32 P]DATP using the Klenow fragment of DNA polymerase and then restriction digested using HaeIII. The 296 bp band was isolated and digested at 37° C. for 1.5 hr using λ exonuclease to progressively release 5′ nucleotides. Adducts provide direct blockages to this stepwise digestion. The remaining lengths of radiolabelled fragment represent blockages and therefore reveal adduct binding sites. The sequence specificity of blockages produced by the Adriamycin/AN9 combination in a region of this sequence is shown in FIG. 12. The sequence is presented 3′-5′. Bands were resolved by electrophoresis and quantitated by PhophorImage analysis to determine the relative intensity of each band corresponding to a drug blockage site. Each blockage site is represented as the mole fraction of total blockages at the corresponding sequence. The striking 5′-GC specificity of the combination is similar to that observed in numerous in vitro experiments, indicating that the adducts formed in vitro and in cells are likely to be of the same structure. It is apparent that the adducts occur at every 3′-CG sequence examined. Of the 6 blockages represented, this includes all four of the 5′-GC sites represented and two 5′-GG sites within the fragment that were analysed. The blockage to exonuclease digestion generally occurs anywhere from 1-4 nucleotides prior to the site of adduct formation, however at the last site the blockage is 4-6 nucleotides prior to the likely site of adduct formation, and this may be due to structural deviations posed to λ exonuclease at the extreme end of the fragment.
EXAMPLE 15
Binding of AN-9 Induced Adriamycin Adducts to RNA, DNA and Protein
[0210] In order to assess whether AN-9 causes Adriamycin adduct formation with cellular macromolecules other than DNA, adduct formation in RNA, DNA and protein were assessed simultaneously. IMR-32 cells (1×10 6 cells) were seeded into 3.5 cm petri dishes and cells were allowed to attach overnight. Cells were treated with 6 μM [ 14 C]-Adriamycin for a total of 4 hr and AN-9 was used at a final concentration of 300 μM. Treatments consisted of Adriamycin alone (Adr), AN-9 added 2 hr earlier (−2), AN-9 added simultaneously (0), or AN-9 added 2 hr after Adriamycin (+2). Cells were then harvested and RNA, DNA and protein were isolated simultaneously using TRI Reagent (Astral). Incorporation of radioactive Adriamycin into each of the fractions was assessed by scintillation counting. The concentration of RNA, DNA and protein in each fraction were also determined. FIG. 13 shows the number of adducts per pg of nucleic acid or protein. This figure demonstrates that adducts mainly form within DNA. DNA was also the dominant target for adduct formation with mitoxantrone and AN-9 (data not shown).
EXAMPLE 16
Alternative Aldehyde-Releasing Compounds
[0211] The series of aldehyde-releasing compounds that were examined was extended to include those that release two molecules of formaldehyde per aldehyde-releasing compound and more than one molecule of butyric acid per aldehyde-releasing compound (compounds AN-189 to AN-194). These compounds were synthesised using the same procedure used in the synthesis of AN-9 as described in A. Nudelman, M. Ruse, A. Aviram, R. Rabizadeh, M. Shaklai, Y. Zimrah and A. Rephaeli, 1992. The procedure was modified by replacing butyric acid with another acid and chloromethyl pivalate with the subject chloromethyl ester.
[0212] To examine adduct formation in the presence of these aldehyde-releasing compound, IMR-32 cells were seeded into 3.5 cm petri dishes at a density of 7.5×10 5 cells/dish 24 hr prior to exposure to 2 μM [ 14 C] Adriamycin for 4 hr. These were simultaneously incubated with the indicated aldehyde-releasing compound at a final concentration of 100 μM. Samples were harvested as indicated previously and DNA was assessed for incorporation of radioactively labelled Adriamycin. The results are shown below in Table 4.
TABLE 4 Treatment Adducts/10 kb Adr alone 0.54 ± 0.04 Adr + AN-9 4.63 ± 0.59 Adr + AN-1 11.45 ± 0.65 Adr + AN-38 5.13 ± 1.42 Adr + AN-37 3.26 ± 0.26 Adr + AN-188 0.7 ± 0.16 Adr + AN-189 0.5 ± 0.04 Adr + AN-191 0.52 ± 0.01 Adr + AN-192 27.1 ± 0.8 Adr + AN-194 29.5 ± 1.5
[0213] At this concentration of Adriamycin (Adr), background levels of adducts were observed with the use of Adriamycin alone. This figure did not increase significantly when acetaldehyde-releasing drugs were used (AN-188, AN-189, AN-191). While AN-189 and AN-191 each released two molecules of acetaldehyde rather than the one released by AN-188, this did not enhance adduct formation. Interestingly, the derivative that releases two molecules of butyric acid and one of formaldehyde enhanced adduct formation at least two-fold higher than AN-9. This indicates an added benefit of this small structural change. The reason for enhanced adduct formation may be better localisation of this drug to the nucleus and/or enhancement of formaldehyde-facilitated adducts by butyric acid. The use of the new aldehyde-releasing compounds which each release two molecules of formaldehyde greatly improved Adriamycin adduct formation with at least a 5-fold increase of adducts compared to the same concentration of AN-9. This increase is far greater than the expected 2-fold increase that was expected to flow from the release of two molecules of formaldehyde instead of one.
EXAMPLE 17
Compounds that Release Aldehyde and an Agent that Enhances Intracellular Levels of Aldehyde
[0214] The results provided above indicated that compounds that release an agent that enhances intracellular levels of aldehyde would be good candidates for use in the methods of the invention. One particularly preferred compound of this class releasing BSO formaldehyde and acid in situ. This compound is synthesised using the same procedure used in the synthesis of AN-9 as described in Nudelman, 1992. The procedure is modified by replacing butyric acid with BSO [Me(CH 2 ) 3 —S(═O) (═NH)—CH 2 —CH 2 CH(—NH 2 )—COOH] and replacing chloromethyl pivalate with chloromethyl butyrate. The ═NH and —NH 2 functional groups of BSO are firstly protected with a protecting group such as t-butoxycarbonyl (t-BOC) before being reached with chloromethyl butyrate. In a final step, the protecting groups are removed with an acid.
EXAMPLE 18
Useable Chemotherapeutics Agents
[0215] In order to test whether chemotherapeutic agents other than the anthracyclines can be activated to form DNA adducts by AN-9, cells were treated with the anthracenedione drug mitoxantrone in the presence and absence of AN-9. Mitoxantrone (see structure below) has been shown to form adducts in the presence of formaldehyde in cell-free systems (Parker et al., 1999). IMR-32 cells (1×10 6 ) were seeded into 3.5 cm petri dishes and allowed to attach overnight. Cells were incubated with 20 μM [ 14 C] mitoxantrone (Mitox) and 500 μM AN-9 at times ranging from 16 hr before mitoxantrone addition to 4 hr after (−16 to +4). Total mitoxantrone incubation time was 6 hr. Cells were harvested and DNA extracted using a modified QIAamp procedure prior to [ 14 C] mitoxantrone counts and DNA concentration being determined. The adducts detected per 10 kb are shown below in Table 5.
[0216] Structure of Mitoxantrone
TABLE 5 Treatment Time of AN-9 addition Adducts/10 kb Mitox alone 0.36 ± 0.06 Mitox + AN-9 −16 0.77 ± 0.01 Mitox + AN-9 −2 0.93 ± 0.04 Mitox + AN-9 simultaneous 1.4 ± 0.12 Mitox + AN-9 +2 1.62 ± 0.01 Mitox + AN-9 +4 1.78 ± 0.1
[0217] This result shows that like Adriamycin, mitoxantrone can also be activated to form adducts in the presence of AN-9 in a cell culture assay. Furthermore, the pattern of activation is similar to Adriamycin in that the adducts are more pronounced when AN-9 is added after-mitoxantrone.
EXAMPLE 19
In Vito Efficacy
[0218] In order to determine the efficacy of the compounds of the invention human prostate carcinoma (PC-3) or human uterine sarcoma (MES-SA/DX5, resistant to doxorubicin) cells (5×10 6 ) are implanted subcutaneously into both rear flanks of athymic nude mice (nu/nu, weighing 17-20 g). After 2-3 weeks, randomized groups of animals, each containing 10 tumour-bearing mice, are treated as follows:
[0219] (a) Control group, vehicle only, weekly×2
[0220] (b) Doxorubicin as single agents 2 mg/kg, weekly×2
[0221] (c) Doxorubicin as single agent, 4 mg/kg, weekly×2
[0222] (d) Doxorubicin as single agent, 8 mg/kg, weekly×2
[0223] (e) Test compounds of formula I at 20 mg/kg, weekly×2
[0224] (f) Test compounds of formula I at 40 mg/kg, weekly×2
[0225] (g) Test compounds of formula I at 80 mg/kg, weekly×2
[0226] (h) The combination of treatments b and e
[0227] (i) The combination of treatments c and f
[0228] In the combination treatment, doxorubicin is given first and the compound is given 4 hr later.
[0229] When control tumours reach the size of 2 g, the experiment is terminated, mice are weighed twice weekly, and tumour measurements are taken by calipers twice weekly. Tumour measurements are converted to tumour weight by the formula L 2 ×W/2 where L and W are the length and width of the tumour respectively. These calculated tumour weights are used to determine the termination date. Upon termination, all mice are weighed, sacrificed, and their tumours excised. Tumours are weighed, and the mean tumour weight per group is calculated. In this model, the mean control tumour weight/mean treated tumour weight×100% (C/T) is subtracted from 100% to give the tumour growth inhibition (TGI) for each group. Some animals experience tumour shrinkage. For these mice, the final weight of a given tumour is subtracted from its own weight at the start of treatment. The difference divided by the initial tumour weight is the % shrinkage. Mean % tumour shrinkage is calculated from data in the group that experienced regressions.
EXAMPLE 20
In Vivo Adduct Formation
[0230] Two animals from each of the treatment groups defined in Example 19 are sacrificed 30 min after the last treatment. Tumour, heart, liver, kidney, and brain are isolated and snap frozen. To determine the conditions (eg, best test compound, best schedules) which lead to adduct formation in tumour DNA samples, a Southern hybridisation-based assay is used. Human tumour and mouse tissue samples are maintained at −80° until they are processed for DNA isolation. DNA isolation procedures are designed to minimise loss of Adriamycin adducts. Specifically, frozen samples are homogenised mechanically in frozen homogenisers. DNA is isolated from the frozen powder using a modified QIAamp procedure, and processed as previously described for the Southern hybridisation procedure (see Example 2). However, as the previously described hybridisation procedure is only specific for human samples (human DHFR and mitochondrial DNA probes) the DNA extracted from mouse tissues will be restriction digested with Kpn I (for DHFR detection), or an enzyme which linearises the mouse mitochondrial genome (eg. Xho I) for detection of adducts in mitochondrial DNA. These samples are subjected to hybridisation with mouse DRFR and mitochondrial DNA probes. Specifically, these probes are PCR products amplified from mouse genomic DNA (Kalinowski et al., 1992). The amount of virtual crosslinks in each sample are determined as previously described (Cullinane et al., 2000).
[0231] It will be apparent to the person skilled in the art that while the invention has been described in some detail for the purposes of clarity and understanding, various modifications and alterations to the embodiments and methods described herein may be made without departing from the scope of the inventive concept disclosed in this specification.
[0232] References cited herein are listed on the following pages, and are incorporated herein by this reference.
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[0254] Perrin L C, Cullinane C, Kimura K-I and Phillips D R (1999) Barminomycin forms GC-specific adducts and virtual interstrand crosslinks with DNA. Nucleic Acids Res 27, 1781-1787.
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[0264] Zeman S M, Phillips D R and Crothers D M (1998) Characterisation of covalent adriamycin-DNA adducts. Proc Natl Acad Sci (USA) 35, 11561-11565. | A method of treating cancer, comprising the step of administering to a subject in need thereof an effective amount of a compound or compounds which increase or supplement the intracellular levels of endogenous aldehyde, prior to, together with, or subsequent to the administration of a therapeutically-effective amount of a chemotherapeutic agent such as anthracyclines and anthracenediones, wherein the efficacy of the chemotherapeutic agent is enhanced relative to the efficacy of the chemotherapeutic agent alone. The compound may be an aldehyde-releasing compound (preferably formaldehyde), including known aldehyde-releasing compounds and two new classes of aldehyde-releasing compounds. One new class of aldehyde-releasing compounds of formula (II) release more than one equivalent of aldehyde Z-(L-M 1 -CHR-M 2 ) x (II) wherein x is an integer of 2 or more Z is a direct bond or a linking group of valency x; L is either a direct bond or a spacer group R is H or C1-4 alkyl, alkenyl or alkynyl; M 1 is a decomposable or hydrolysable group; and M 2 is a second decomposable or hydrolysable group. Another new class of aldehyde-releasing compounds include a radical based on an inhibitor of an aldehyde detoxifying agent, such as buthionine sulphoximine or crotonaldehyde. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to GB 0919393.9 filed Nov. 5, 2009, which is hereby incorporated by reference in its entirety.
BACKGROUND
1. Technical Field
This disclosure relates to cooling systems for a motor vehicle having an internal combustion engine.
2. Background Art
As internal combustion engines become more fuel efficient, less waste heat is produced and consequently, the time taken to reach an optimum running temperature increases. This protracted time has a deleterious effect on fuel economy and engine wear.
Hence, a cooling system which reduces the time taken for a cold engine to reach its optimum running temperature would be desirable.
SUMMARY
Accordingly, in a first embodiment, the present disclosure comprises a cooling system for a motor vehicle having an internal combustion engine, said cooling system including a pump for supplying coolant to the engine, an outflow conduit for connecting the pump outlet to the engine, and a return circuit for connecting the engine to the pump inlet, wherein the return circuit comprises three branches, a first branch including a first valve, a second branch including a radiator and thermostat, and a third branch including a heater matrix, a degas tank and a second valve.
The second branch of the return circuit may further include an engine oil cooler.
The first and second valves may be controlled electronically and the cooling system includes a control unit for controlling the valves in response to an input from at least one of the following onboard vehicle devices; an engine coolant temperature sensor, an ambient air temperature sensor, a timer, a cabin heating demand sensor, an engine operating condition sensor.
The engine operating condition sensor may be, for example, a sensor which detects engine speed, engine load, throttle position or mass air flow into the engine.
To prevent damage to the pump if malfunction of the control unit were to occur, the first valve has its default position set to the closed position and the second valve to has its default position set to the open position.
In accordance with a second embodiment, the present disclosure includes a method of operating a cooling system for a motor vehicle having an internal combustion engine, wherein the cooling system includes a pump for supplying coolant to the engine, an outflow conduit for connecting the pump outlet to the engine, and a return circuit for connecting the engine to the pump inlet, the return circuit comprising three branches, a first branch including a first valve, a second branch including a radiator and thermostat, and a third branch including a heater matrix, a degas tank and a second valve. The method includes: opening both first and second valves for a period long enough to flush air from the system when the engine is started cold. Then, both valves are closed. At least one engine operating condition and engine coolant temperature are monitored. The first valve is closed if one engine operating condition exceeds a pre-set level; and the second valve is opened if engine coolant temperature exceeds a threshold value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a cooling system in accordance with a preferred embodiment of the disclosure,
FIG. 2 is a chart illustrating an operating regime of a first valve which is included in the system of FIG. 1 , and
FIG. 3 is a chart illustrating an operating regime of a second value which is included in the system of FIG. 1 .
DETAILED DESCRIPTION
As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the Figures may be combined with features illustrated in one or more other Figures to produce alternative embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. Those of ordinary skill in the art may recognize similar applications or implementations consistent with the present disclosure, e.g., ones in which components are arranged in a slightly different order than shown in the embodiments in the Figures. Those of ordinary skill in the art will recognize that the teachings of the present disclosure may be applied to other applications or implementations.
With reference to FIG. 1 , a water pump 1 supplies coolant to an internal combustion engine 2 via a conduit 3 which connects the pump outlet to the engine 2 .
Coolant returns to the inlet side of the pump 2 via a return circuit which comprises three branches. A first branch 4 includes an electronically controllable bypass valve 5 . A second branch 6 includes a radiator 7 and thermostat 8 . A third branch 9 includes a heater matrix 10 , an engine oil cooler 11 and electronically-controllable heater/degas valve 12 and a degas tank 13 connected via a side branch 14 upstream of the heater/degas valve 12 and downstream of the oil cooler 11 and heater matrix 10 .
A temperature sensor 15 is provided on the engine 2 for monitoring the temperature of the coolant at the point at which it leaves the engine 2 .
An electronic control unit (ECU) 16 is electrically connected with the bypass valve 5 and the heater/degas valve 12 and controls opening and closing of each valve 5 , 12 . The ECU 16 receives inputs from a timer 17 , an ambient air temperature sensor 18 , an engine speed sensor 19 and a cabin heater demand sensor 20 . A conduit 21 links the engine 2 directly with the degas tank 13 . Alternatively engine speed sensor 19 may be an engine load sensor, a throttle position sensor, or a mass airflow sensor.
Operation of the system of FIG. 1 is described with particular reference to FIGS. 2 and 3 in which FIG. 2 shows operation of valve 5 , a first valve, and FIG. 3 shows operation of valve 12 , a second valve, according to one example embodiment. The specific ranges in speed and temperature shown in the table and the numbers provided herein are non-limiting and merely serve to provide one example.
During operation, the ECU 16 constantly monitors engine coolant temperature, engine speed, ambient air temperature and cabin heat demand (as requested by the occupants of the vehicle) and is also responsive to a signal from the timer 17 . In response to these various inputs, the ECU 16 opens or closes each of the valves 5 , 12 in accordance with a pre-set operating regime.
For a few seconds immediately following a cold start of the engine 2 , both valves 5 , 12 are opened. This measure serves to flush out air that might be in the system. After ten seconds (in this example) have elapsed, as measured by the timer 17 , both valves are closed. Provided that engine speed remains relatively low, both valves 5 , 12 remain closed. With both valves 5 , 12 closed and the thermostat 8 also closed, there is virtually no circulation of coolant through the engine 2 and so the engine warms up quickly. However, if engine speed reaches a threshold value, say 2300 rpm in this example, then the bypass valve 5 is opened to prevent cavitation occurring in the pump 1 . If the engine speed continues to increase, say beyond 3000 rpm them the heater/degas valve 12 is also opened to ensure that no pump damage can occur.
If engine rpm remains within the lower limit, then both valves 5 , 12 remain closed until the engine coolant temperature reaches an intermediate (medium) value, say 60 degrees Celsius, whereupon the bypass valve 5 is opened. This allows some coolant flow through the engine while the thermostat 8 remains shut.
The heater/degas valve remains closed until engine coolant temperature rises further to around 80 degrees Celsius, say, unless ambient air temperature is very low or the occupants demand some cabin heating in which case it is opened sooner.
Throughout the engine coolant temperature range from around 80 degrees Celsius to the point at which the thermostat opens, say 103 degrees Celsius, both valves 5 , 12 are open, irrespective of engine speed. Hence (warm) coolant is supplied to the heater matrix and to the oil cooler for warming the cabin of the vehicle and for maintaining engine oil at an optimum temperature.
Once this threshold temperature of 103 degrees Celsius is exceeded and the thermostat 8 is open, the bypass valve 5 is closed allowing full flow of coolant through the radiator 7 .
If the engine 2 is switched off and the restarted when still hot, the bypass valve 5 is closed and the heater/degas valve is opened.
The default (unpowered) position of the bypass valve 5 is closed and the default (unpowered) position of the heater/degas valve 12 is open. Hence if the ECU 16 fails, the valves 5 , 12 allow coolant to flow such that no damage to the pump 1 or a hot engine 2 can occur.
While the best mode has been described in detail, those familiar with the art will recognize various alternative designs and embodiments within the scope of the following claims. Where one or more embodiments have been described as providing advantages or being preferred over other embodiments and/or over prior art in regard to one or more desired characteristics, one of ordinary skill in the art will recognize that compromises may be made among various features to achieve desired system attributes, which may depend on the specific application or implementation. These attributes include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. The embodiments described as being less desirable relative to other embodiments with respect to one or more characteristics are not outside the scope of the disclosure as claimed. | A cooling system for a vehicle having an internal combustion engine permits rapid warm-up of the engine by the use of two electrically-operated valves in addition to a conventional thermostat. A bypass valve and a heater valve both remain closed at low coolant temperatures and engine speeds, thereby inhibiting coolant flow through the engine. A control unit opens the bypass valve to prevent cavitation in the water pump if engine speed and/or load exceeds a certain value. The heater valve is opened when a threshold engine coolant temperature is reached permitting warming of the heater matrix. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a foldable knife, and more particularly to a structure of a foldable knife in which a handle locks and pivotally supports a blade.
2. Description of the Related Art
A conventional foldable knife includes a blade 51 and a pair of halt handles 52. As shown in FIG. 5, the half handles 52 pivotally hold a blade 51. A spring 53 biases one end of a back metal 54 outward, thereby causing the opposite end 55 of the back metal 54 to engage a tang 56 of the blade 51. The blade 51 is locked either in the unfolded state as shown in FIG. 5 or in a folded state, accordingly.
A relatively burdensome procedure is required to unlock and pivot the blade 51. First, the biased end of the back metal 54 is pressed against the force of the spring 53 by using a hand of the user so that the back metal pivots around the pin 57. The other end of the back metal 54 thus disengages from the tang 56 of the blade 51. Then the blade may be extended by using the other hand of the user.
SUMMARY OF THE INVENTION
It is a major object of the present invention to provide a foldable knife with high operability having a blade which is securely locked when extended and held in place when folded in the handle.
To achieve the foregoing and other objects in accordance with the purpose of the present invention, an improved foldable knife is provided.
A foldable knife according to the present invention includes a handle having a pair of sides, a front edge and a back edge. The knife also has a folding blade having a sharp edge and a back edge opposite to the sharp edge. The blade is pivotable about an axis between a folded position and an extended position such that the back edge of the blade is aligned with the back edge of the handle when the blade is in its extended position and such that the sharp edge enters the handle through the front edge of the handle when it is folded. The knife also includes a mechanism for releasably locking the blade in its extended position and for applying resistance to the blade in its folded position. The mechanism includes a ratchet member having at least a first notch and a second notch formed therein. The ratchet member is connected to the blade. The mechanism also includes a pivotable locking lever for engaging the ratchet member or locking the blade in its extended position and for applying resistance to the blade when the blade is in its folded position. The locking lever has a portion that extends from the front edge of the handle so that it may be manually manipulated to disengage the locking lever from the ratchet member to release the blade from its extended position.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention together objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is an exploded perspective view of a foldable knife according to the present invention;
FIG. 2A is a partial sectional view of the foldable knife with its blade fully extended and FIG. 2B is a partial sectional view of the foldable knife with its blade folded;
FIG. 3 is a sectional view taken along line L--L of FIG. 2B;
FIG. 4 is an exploded perspective view of a foldable knife according to another embodiment of the present invention; and
FIG. 5 is a sectional view illustrating a conventional knife.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment which embodies the present invention will be described below in detail referring to FIGS. 1 to 3.
A handle includes a right outer plate 1a and a left outer plate 1b. A right inner plate 2a and a left inner plate 2b are fitted in the right outer plate 1a and the left outer plate 1b, respectively. Flanges 5a and 5b are formed on the peripheral portion of the outer plates 1a and 1b, respectively, The outer plates 1a and 1b are joined together to form the handle by cementing the flanges 5a and 5b together. The space between the inner plates 2a and 2b serves as a space 6 for accommodating the blade 3 when the knife is folded. A back metal 7 is placed between the inner plates 2a and 2b. The back metal 7 is sandwiched by the inner plates 2a and 2b and fixed there with rivets 25, The outer surface of the back metal 7 fully contacts the inner wall formed by the cemented flanges 5a and 5b.
The blade 3 has a tang 10 at its proximal end. The tang 10 has a hole 26 formed therethrough. A shaft 13 is inserted in the through hole 26. The ends of the shaft 13 are screwed in the outer plates 1a and 1b, respectively. A washer 4 is placed around the shaft 13 between the tang 10 and the inner plate 2a and between the tang 10 and the inner plate 2b. The blade 3 is pivotally supported between the inner plates 2a and 2b, accordingly. A cavity 14 is formed inside a portion of the right outer plate 1a for accommodating a ratchet mechanism that restricts the pivotal movement of the blade 3.
The back metal 7 serves as a stop wall 7a. A part next to the stop wall 7a protrudes inward to form a projection 7b. The projection 7b has a half circular cross section. The stop wall 7a contacts the tang 10 of the blade 3 when the blade 3 is fully extended as shown in FIG. 2A. The projection 7b contacts the heel of the blade 3 when the blade 3 is folded as shown in FIG. 21. Shafts 8 and 9 penetrate the back metal 7. One end of each shaft 8 and 9 also penetrates the right inner plate 2a and contacts the right outer plate 1a. The other end of each shaft penetrates the left inner plate 2b and is screwed in the left outer plate 1b.
As shown in FIG. 3, one end of the shaft 13 penetrates a through hole 19b formed on the left inner plate 2b and is screwed in the left outer plate 1b. The other end of the shaft 13 penetrates a through hole 19a formed on the right inner plate 2a and is screwed in the right outer plate 1a.
As shown in FIG. 2A, a finger lever having a serrated surface 11 is formed on the edge of the tang 10. This surface may alternatively be roughened by knurling or other similar procedure. As soon in FIG. 2A, the serrated surface 11 protrudes from the front side of the outer plates 1a and 1b when the blade 3 is extended. Moving the serrated surface 11 in the direction of arrow A rotates the blade 3 accordingly. As shown in FIG. 2B, the serrated surface 11 protrudes from the back of the outer plates 1a and 1b when the blade 3 is folded. Moving the serrated surface 11 in the direction of arrow B rotates the blade 3 in the same direction.
A part of the tang 10 adjacent to its back serves as a contact wall 10a. The contact wall 10a contacts the stop wall 7a of the back metal 7 when the blade 3 is fully extended. This restricts further rotation of the blade 3 in the opposite direction of arrow A.
A half ring shaped slit 20 is formed on the right inner plate 2a. The slit 20 is concentric with the through hole 19a and has a larger radius of curvature than the diameter of the plate 4. A pin 12 is provided on the surface of the tang 10 facing the right inner plate 2a. The distal end of the pin 12 is inserted in the slit 20. The pin 12 slides in the slit 20 as the tang 10 of the blade rotates The ratchet mechanism includes a ratchet wheel 15 provided between the right inner plate 2a and the right outer plate 1a, a locking lever 16 provided between the ratchet wheel 15 and a coil spring 17. The ratchet wheel 15 is rotatably supported by the shaft 13. The distal end of the pin 12, which protrudes from the slit 20 of the inner plate 2a, is inserted in a hole 12a formed on the ratchet wheel 15. The pin 12 moves within the slit 20, thereby restricting the rotational movement of the ratchet wheel 15, accordingly.
A pair of notches 18 are formed in the periphery of the wheel 15 opposite to each other. Each notch 18 includes a straight part 18a and a curled part 18b. As shown in FIG. 2A, imaginary lines extended from the straight part 18a of each notch are practically parallel and the distance from the center of the wheel 15 to the imaginary lines are equal,
One end of the locking lever 16 is pivotally supported by the shaft 8, and the other end has a projection 21. The projection 21 protrudes from a notch 24 formed on the front side of the right outer plate 1a. The notch 24 is large enough to allow the projection 21 to be moved for controlling the blade 3. Moving the projection 21 in the direction of arrow C and in the opposite direction causes the locking lever 16 to pivot around the shaft 8. The locking lever 16 has a pawl 22 in the approximate center of a side 16b facing the ratchet wheel 15. The pawl 22 engages and disengages with the notches 18. The pawl 22 has a straight part 22a and a curved part 22b that correspond to the notches 18.
The coil spring 17 has a ring portion 17c. The coil spring 17 is attached to the inner plate 2a at a ring portion 17c by the shaft 9. One end 17b of the coil spring 17 contacts a pin 23 provided on the right inner plate 2a. The other end 17a of the coil spring 17 contacts the locking lever 16. The coil spring 17 therefore biases the locking lever 16 in the direction of arrow C. As shown in FIG. 2A, when the blade 3 is fully extended, the coil spring 17 urges the locking lever 16 in the direction of arrow C so that the pawl 22 engages one of the notches 18. The tip of the pawl 22 contacts the straight part 18a of the engaged notch 18. This causes the blade 3 to be locked in position. Even partial contact of the straight part 22a of the pawl 22 with the straight part 18a of the engaged notch 18 ensures the locking of the blade 3.
As shown in FIG. 2B, when the blade 3 is folded, the coil spring 17 biases the locking lever 16 in the direction of arrow C, causing the pawl 22 to engage the other notch 18. The proximate portion of the curved part 22b of the pawl 22 contacts the outer portion of the curved part 18b of the notch 18. This applies resistance to the blade 3, but does not lock it in place. This ensures that blade 3 will be held firmly in the accommodating space 6.
The procedure for extending the blade 3 from the folded state and for locking the blade 3 at the extended state will be now described. As shown in FIG. 2B, the serrated surface 11 of the tang 10 is moved in the direction of arrow B. This rotates the ratchet wheel 15, which is interlocked to the tang 10 with the pin 12, in the direction of arrow B. The rotation of the wheel 15 presses the curved part 18b of the engaged notch 18 against the curved part 22b of the pawl 22. This causes the pawl 22 to move against the force of the coil spring 17. The pawl 22 disengages from the notch 18 and the blade 3 slightly protrudes from the handle, accordingly. Shaking the knife applies centrifugal force to the blade 3, thereby causing the blade 3 to rotate approximately 180 degrees, The rotation of the blade 3 is stopped when the contact surface 10a and the stop wall 7a contact. At this time, the ratchet wheel 15, which is interlocked with the tang 10 of the blade 3 with the pin 12, is also rotated. When one of the notches 18 of the wheel 15 reaches the pawl 22 of tho locking lover 16, the force of the coil spring 17 pushes the locking lever 16 so that the pawl 22 engages the nearest notch 18. The ratchet wheel 15 thus becomes locked. This locks the blade 3, which is interlocked to the ratchet wheel 15 at its extended position.
The following procedure is taken to fold the fully extended blade 3. As shown in FIG. 2A, the locking lever 16 is moved against the force of the coil spring 17 by moving the projection 21 in the direction opposite to arrow C. This disengages the pawl 22 from the notch 18. Next, the blade 3 is slightly rotated by pushing the serrated surface 11 in the direction of arrow A. The back of the blade 3 is pressed so that the blade 3 is folded and accommodated in the space 6. At this time, the ratchet wheel 15, which is interlocked to the tang 10 of the blade 3, is also rotated. The force of the coil spring 17 pushes the locking lever 16 in the direction of arrow C. Therefore, when the nearest notch 18 reaches the pawl 22, the pawl 22 engages with it. This causes the ratchet wheel 15 and the blade 3, which is interlocked to the wheel 15, to be locked.
In the knife according to the present invention, the blade 3 is locked when the straight part 22a of the pawl 22 only partly contacts the straight part 18a of the engaged notch 18. Therefore, high accuracy is not necessarily required for forming the notches 18 and the pawl 22. Accordingly, assembling the knife does not requires precision and therefore is easy.
Although only one embodiment of the present invention has been described so far, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, the invention may be embodied in the following forms.
In the above described embodiment, only two notches 18 are formed. However, three or more notches may be formed on the ratchet wheel so that the blade 3 may be locked at a desired degree between 0 to 180 degrees with respect to the outer plates 1a and 1b.
Instead of the coil spring 17, other types of resilient member, such as a leaf spring or rubber, may be used.
In the above described embodiment, the tip of the back metal 7 serves as the stop wall 7a and part of the tang 10 serves as the contact surface 10a so that the stop wall 7a and the contact surface 1a contact one another to stop the rotation of the blade 3. However, as shown in FIG. 40 recesses 31 having a half circle cross section may be formed on the back of the blade 3 and on the edge side of the blade 3 next to the serrated surface 11 respectively. A projection 32 having a half circular shape in cross section may be formed at the end of the back metal 7. The rotation of the blade 3 is thus stopped by engaging the projection 32 and one of the recesses 31.
In the first embodiment, the projection 21 of the locking lever 16 protrudes from the notch 24 formed on the edge of the right outer plate 1a. However, as shown in FIG. 4, a slot 27 may be formed on the right outer plate 1a from which the projection 28 of the locking lever 16, which is shorter than that of the first embodiment, protrudes. Moving the projection 28 in the direction of arrow C and in the opposite direction pivots the locking lever 16 around the shaft 8. The slot 27 is large enough to allow the projection 28 to be moved for controlling the blade 3. The pawl 22 may be easily disengaged from the engaged notch 18 by simply moving the projection 28 while holding the handle in one hand. Then centrifugal force is applied to the knife by shaking the hand that is holding the knife. This causes the blade 3 and the ratchet wheel 15 to rotate approximately 180 degrees so that the pawl 22 engages the other notch 18. Accordingly, the blade 3 is easily controlled to be extended from the folded state and then locked at the extended state.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | A foldable knife includes a handle and a folding blade. The blade is pivotable about an axis between a folded position and an extended position such that a sharp edge enters the handle when it is folded. The knife also includes a mechanism for releasably locking the blade in its extended position and for applying resistance to the blade in its folded position. The mechanism includes a ratchet member having at least two notches formed therein. The ratchet member is connected to the blade. The mechanism also includes a pivotable locking lever for engaging the ratchet member for locking the blade in its extended position and for applying resistance to the blade when the blade is in its folded position. The locking lever has a extending portion that extends from the front edge of the handle so that it may be manually manipulated to disengage the locking lever from the ratchet member to release the blade from its extended position. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Application No. 62/341,146, filed May 25, 2016, and U.S. Provisional Application No. 62/350,228, filed Jun. 15, 2016, the disclosures of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] This disclosure relates to zeolites having alloyed bimetallic clusters encapsulated therein, methods for preparing the same, and uses thereof.
BACKGROUND
[0003] Bimetallic nanoparticle catalysts attract significant interest because of the unique electronic and structural characteristics of catalytically active mixed metal phases, which can confer synergistic enhancements over pure metals in the turnover frequency and selectivity of reactions as diverse as CO oxidation, alkane dehydrogenation, and NO x reduction. These enhancements in the rate and selectivity are often accompanied by further benefits for catalysis. The addition of a second metal may assist in the reduction of the first, improve the thermal stability of metals prone to cluster agglomeration, or preclude deactivation by sulfur or other poisons. Such effects may be brought forth by electronic modifications of the first metal with
[0000] the second, which lead to partial charges that can alter adsorbate binding characteristics, or through coupled but distinct geometric effects in which small ensembles of the first metal are isolated and stabilized by the diluting metal. Rigorous studies that attempt to clearly distinguish these effects or provide a holistic mechanistic interpretation of the reactivity of bimetallic clusters require nanoparticles that are uniformly distributed in size and composition.
[0004] Strategies to prepare such well-defined alloys, however, often face synthetic challenges that preclude the achievement of these stringent requirements for cluster uniformity or may achieve this uniformity only at the expense of general applicability to clusters of diverse elemental composition.
[0005] Bimetallic clusters are most commonly prepared through the sequential adsorption and precipitation or co-impregnation of metal salts onto mesoporous scaffolds. Such techniques, however, suffer from an inability to carefully control the placement of the metals onto the support, and thus lead to bimodal mixtures of monometallic and bimetallic species. Controlled assembly techniques resolve these shortcomings through sequential grafting of organometallic compounds, first onto an oxide support and then onto the covalently anchored metal itself, where the latter step enforces strong metal-metal interactions that promote alloying. These techniques are limited to metals and metal complexes that selectively interact with each other instead of the support, and often form monometallic clusters of the second deposited metal. Galvanic displacement and electroless deposition methods, by contrast, allow the selective placement of a secondary metal onto pre-formed monometallic clusters through redox chemical reactions. These techniques typically result in bimetallic clusters uniformly distributed in composition, though their dispersion is ultimately limited to that of the monometallic seeding metal; the elements available for deposition onto these seeds are also restricted to metals with precursors stable against homogeneous nucleation of their monometallic clusters. Colloidal synthesis techniques, which typically proceed via the reduction of metal cation precursors in the presence of polymers that prevent agglomeration of the suspended nanoparticles, can produce bimetallic clusters that are uniformly distributed in composition and highly dispersed in size. The removal of the attached polymers, however, often requires treatment at elevated temperatures (>573 K), which can lead to sintering processes that compromise the intended size and compositional uniformity of the bimetallic clusters.
[0006] Alloy nanoparticles can alternatively be prepared within the voids of zeolite materials. Confinement within such voids leads to several and additional and distinct advantages for catalysis, including the protection of active metal surfaces from large poison species, the stabilization of specific transition states, and the reactant size selection properties that have made zeolites such ubiquitously useful catalysts. Metal encapsulation within zeolitic voids is achieved through the ion exchange of cationic metal precursors onto negatively charged sites in zeolite frameworks. Reductive treatment of these exchanged zeolites forms monometallic clusters dispersed throughout the zeolitic voids, after which the exchange and reduction of a second metal forms encapsulated bimetallic clusters. Such techniques have been successfully implemented to prepare encapsulated alloy clusters stable against sintering at temperatures in excess of 573 K, although the successive ion exchange process does not guarantee uniform compositions and is limited to zeolites with pore apertures wide enough for solvated metal cations to enter the framework. The apertures within small-pore and medium-pore zeolites preclude post-synthetic encapsulation protocols via ion-exchange from aqueous media, which require the migration of solvated metal-oxo oligomers that cannot diffuse through the small apertures in such zeolites.
[0007] According to the present disclosure, bimetallic clusters narrowly distributed in size and composition have now been encapsulated within the voids of zeolites that preclude post-synthetic encapsulation protocols via a ligand-assisted hydrothermal synthesis technique.
SUMMARY
[0008] In one aspect, the invention resides in an aluminosilicate zeolite having an alloyed bimetallic cluster encapsulated in the pores of the aluminosilicate zeolite.
[0009] In another aspect, the invention resides in a method of synthesizing the aluminosilicate zeolite described herein, the method comprising the steps of: (a) preparing a reaction mixture capable of forming the zeolite, the reaction mixture comprising: a source of silicon oxide; a source of aluminum oxide; a source of a Group 1 or 2 metal (X); hydroxide ions; sources of a first metal precursor (M 1 ) and a second metal precursor (M 2 ) of Groups 8 to 12 of the Periodic Table of the Elements; a ligating agent (L) having a thiol group and an alkoxysilyl group; and water; (b) heating the reaction mixture under crystallization conditions including a temperature of 85° C. to 180° C. and a time from 5 to 250 hours until crystals of the aluminosilicate zeolite are formed; (c) recovering the aluminosilicate zeolite from step (b); (d) contacting the aluminosilicate zeolite of step (c) with oxygen under oxidative conditions including a temperature of 250° C. to 500° C. and a time of 0.5 to 5 h; and (e) contacting the oxidized aluminosilicate zeolite of step (d) with hydrogen under reductive conditions including a temperature of 250° C. to 500° C. and a time of 0.5 to 5 h.
[0010] In a further aspect, the invention resides in a process for converting a feedstock comprising an organic compound to a conversion product that comprises the step of contacting the feedstock with a catalyst at organic compound conversion conditions, the catalyst comprising the aluminosilicate zeolite material described herein.
[0011] In yet a further aspect, the invention resides in a process for selectively reducing nitrogen oxides (NO x ), the process comprising contacting a gaseous stream containing NO x with a catalyst comprising the aluminosilicate zeolite material described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows the powder X-ray diffraction (XRD) patterns of several bimetallic metal-zeolite samples and a metal-free NaLTA zeolite standard.
[0013] FIGS. 2A-2F show transmission electron micrographs (TEM) and particle size distributions for a selection of monometallic and bimetallic metal zeolite samples. FIG. 2A shows the TEM for AuNaLTA; FIG. 2B shows the TEM for Au 50 Pd 50 NaLTA; FIG. 2C shows the TEM for PdNaLTA; FIG. 2D shows the TEM for Au 50 Pt 50 NaLTA; FIG. 2E shows the TEM for PtNaLTA; and FIG. 2F shows the TEM for Pd 65 PT 35 NaLTA.
[0014] FIG. 3 shows the effect of flowing dry air treatment temperature (1.67 cm 3 g −1 s −1 , 5 h) on the TEM-derived surface-averaged cluster diameter ( d TEM ) of metal particles in AuNaLTA (o), Au 50 Pd 50 NaLTA (Δ), and Au 50 Pt 50 NaLTA (□).
[0015] FIGS. 4A and 4B both show the UV-visible absorption spectra of monometallic AuNaLTA (•••), monometallic PdNaLTA ( 4 A) or PtNaLTA ( 4 B) (-•-), a physical mixture of monometallic AuNaLTA and PdNaLTA ( 4 A) or PtNaLTA ( 4 B) (---), and bimetallic Au 67 Pd 33 NaLTA ( 4 A) or Au 67 Pt 33 NaLTA ( 4 B) (solid line).
[0016] FIGS. 5A-5E show the infrared (IR) spectra of carbon monoxide (CO) adsorbed on monometallic or bimetallic Au n Pd 100-n CaLTA samples (1 kPa CO, 99 kPa He) at 278 K after H 2 treatment (573 K, 20 kPa H 2 , 80 kPa He) (gray spectra) and after heating in CO (1 kPa CO, 99 kPa He) up to 353 K (black spectra). FIG. 5A shows the spectrum for Au; FIG. 5B shows the spectrum for Pt; FIG. 5C shows the spectrum for Pt 33 Au 67 ; FIG. 5D shows the spectrum for Pt 50 Au 50 ; and FIG. 5E shows the spectrum for Pt 67 Au 33 .
[0017] FIGS. 6A-6E show the IR spectra of CO adsorbed on monometallic or bimetallic Au n Pd 100-n CaLTA samples (1 kPa CO, 99 kPa He) at 278 K after H2 treatment (573 K, 20 kPa H2, 80 kPa He) (gray spectra) and after heating in CO (1 kPa CO, 99 kPa He) up to 353 K (black spectra). FIG. 6A shows the spectrum for Au; FIG. 6B shows the spectrum for Pd; FIG. 6C shows the spectrum for Pd 33 Au 67 ; FIG. 6D shows the spectrum for Pd 50 Au 50 ; and FIG. 6E shows the spectrum for Pd 67 Au 33 .
[0018] FIG. 7 shows ratios of the integrated intensities of the Pd—CO (bridged) IR absorption bands to the Pd—CO (atop) bands as a function of Pd/Au atomic ratio in AuPdCaLTA bimetallic samples.
[0019] FIG. 8 shows the IR spectra of CO adsorbed on monometallic or bimetallic Pd n Pt 100-n CaLTA samples (1 kPa CO, 99 kPa He) at 313 K after H2 treatment (573 K, 20 kPa H2, 80 kPa He).
[0020] FIG. 9 shows the ratio of the integrated intensity of the Pd—CO (bridged) absorption band (˜1900 cm −1 ) to that of the metal-CO atop band (˜2100 cm −1 ) as a function of Pd content in Pd n Pt 100-n CaLTA samples.
[0021] FIG. 10 shows Fourier transforms (FT) of the k 3 -weighted extended X-ray absorption fine structure (EXAFS) and their corresponding single scattering fits for Au n Pd 100-n NaLTA and Au foil measured at the Au-L 3 edge. Dotted lines represent experimental data, while solid lines represent fitted data.
[0022] FIG. 11 shows Fourier transforms of the k 3 -weighted EXAFS and their corresponding single scattering fits for Au 50 Pd 50 NaLTA, Pd 65 Pt 35 NaLTA, and Pd foil measured at the Pd—K edge. Dotted lines represent experimental data, while solid lines represent fitted data.
[0023] FIG. 12 shows Fourier transforms of the k 3 -weighted EXAFS and their corresponding single scattering fits for Pd 65 Pt 35 NaLTA and Pt foil measured at the Pt-L 3 edge. Dotted lines represent experimental data, while solid lines represent fitted data.
DETAILED DESCRIPTION
Introduction
[0024] The term “alloy” refers to a bonding structure of two or more elements in their reduced or partially reduced forms without limitation to any specific coordination or elemental identity among the elements present.
[0025] The term “cluster” refers to identifiable associations of 2 or more atoms. Such associations are typically established by some type of bond—ionic, covalent, Van der Waals, and the like.
[0026] The term “encapsulated” refers to substances that are completely surrounded by another material. In the context of the present disclosure, an encapsulated metal is a metal enclosed within microporous zeolite voids.
[0027] The powder X-ray diffraction (XRD) data reported herein were collected with a D8 Discover GADDS Powder Diffractometer with Cu-K□ radiation (□=0.15418 nm, 40 kV, 40 mA). The samples were first ground to fine powders, then placed and leveled on quartz slides for the measurements. Diffractograms were measured for 2θ values ranging from 5-50° and a scan rate of 0.00625 degrees s −1 .
[0028] The transmission electron micrographs (TEM) reported herein were collected with a Philips/FEI Technai 12 microscope. Samples for TEM imaging were prepared by dispersing finely ground powders in acetone and depositing them onto holey carbon films supported on 400 mesh copper grids (Ted Pella Inc.). Metal cluster size distributions were measured from >300 particles for each sample, and used to determine surface-averaged cluster diameters d TEM according to Equation (1):
[0000]
〈
d
TEM
〉
=
∑
n
i
d
i
3
∑
n
i
d
i
2
(
1
)
[0000] where n i is the number of clusters with diameter d i . These size distributions were further used to calculate dispersity index (DI) values, which are given by the ratio of the surface-averaged ( d TEM ) to the number-averaged ( d n ) diameter according to Equation 2:
[0000]
DI
=
〈
d
TEM
〉
〈
d
n
〉
=
(
∑
n
i
d
i
3
∑
n
i
d
i
2
)
(
∑
n
i
d
i
∑
n
i
)
(
2
)
[0000] The DI value indicates the particle size uniformity, with unity corresponding to perfect monodispersity and values<1.5 taken as nearly monodisperse distributions. DI values are not widely reported despite IUPAC guidelines; therefore, standard deviations of the mean particle diameters are also reported here to provide a second metric of the particle size uniformity.
[0029] Metal dispersions (D), defined as the fraction of metal atoms exposed at cluster surfaces, were estimated from d TEM according to Equation (3):
[0000]
D
=
6
v
_
m
/
a
_
m
〈
d
TEM
〉
(
3
)
[0000] where v m is the effective bulk atomic density of the bimetallic samples, estimated as the composition-weighted average of the v m values for pure Au (16.49×10 −3 nm 3 ), Pd (14.70×10 −3 nm 3 ), or Pt (15.10×10 −3 nm 3 ). The value of ā m , the effective area occupied by a metal atom on polycrystalline surfaces, was also calculated as a composition-weighted mean from the pure component values (Au: 8.75×10 −2 nm 2 ; Pd: 7.93×10 −2 nm 2 ; Pt: 8.07×10 −2 nm 2 ).
[0030] UV-visible spectra of synthesized and treated metal-zeolite samples reported herein were acquired using a Varian-Cary 6000i spectrometer with a Harrick scientific diffuse reflectance accessory (DRP-XXX) and a reaction chamber add-on (DRA-2CR). The spectra were collected under 100 kPa of He at ambient temperature for AuNaLTA, Au n Pd 100-n NaLTA, and Au n Pt 100-n NaLTA (0.1 g each) powders, which were ground and sieved to retain <100 μm aggregates. Background spectra were used to isolate the effect of the embedded metals on the spectral absorbance, and were collected on NaLTA samples synthesized and treated as the metal-NaLTA.
[0031] Infrared (IR) spectra of CO adsorbed on Au n Pd 100-n CaLTA, Au n Pt 100-n CaLTA, and Pd n Pt 100-n CaLTA wafers (40 mg cm −2 ) were collected to probe the surface compositions of metal particles. Spectra reported herein were acquired with a Thermo Nicolet 8700 spectrometer equipped with an in situ flow cell. All sample wafers were first heated in flowing H 2 /He mixtures (8.4 cm 3 g −1 s −1 H 2 , 33.6 cm 3 g −1 s −1 He) from ambient temperature to 573 K (0.033 K s −1 ) for 1 h. The Pd n Pt 100-n CaLTA samples were then rapidly cooled in He flow (42.0 cm 3 g −1 s −1 ) to 313 K (−0.17 K s −1 ), and exposed to flowing CO/He (42.0 cm 3 g −1 s −1 ; 1.0 kPa CO) before collecting IR spectra. Au n Pd 100-n CaLTA samples, after the H 2 /He treatment at 573 K, were instead cooled to 278 K (−0.17 K s −1 ), in flowing He (42.0 cm 3 g −1 s −1 ), after which spectra were also collected under flowing CO/He (42.0 cm 3 g −1 s −1 ; 1.0 kPa CO). The Au n Pd 100-n CaLTA samples were then heated in this flowing CO/He to 353 K (0.033 K s −1 ) for 0.5 h, and then cooled back to 278 K (−0.17 K s −1 ) under continuous CO flow at which time a second spectrum was collected. Au n Pt 100-n CaLTA samples were treated analogously to Au n Pd 100-n CaLTA, except they were cooled to 263 K instead of 278 K. The AuPd and AuPt bimetallic samples were subjected to this intermittent period of CO exposure and heating with the intent of inducing changes in the surface compositions of alloyed clusters. The NaLTA zeolites (0.42 nm apertures), produced by the synthesis procedures reported herein, were exchanged with Ca 2+ (forming CaLTA; 0.50 nm apertures) before these experiments to enlarge pore windows and improve the accessibility of CO to the zeolite interior. Spectral contributions from CO(g) and Ca 2+ —CO complexes were subtracted from all reported spectra.
[0032] X-Ray absorption spectroscopy (XAS) data reported herein was performed at the Au-L 3 edge (11,919 eV), Pd—K edge (24,350 eV), and Pt-L 3 edge (11,564 eV) using the XDS beamline of the LNLS (Laboratório Nacional do Luz Síncrotron, Campinas, Brazil). Two-crystal Si(311) or Si(111) monochromators were employed for absorption measurements at the Pd—K edge or Au-L 3 and Pt-L 3 edges, respectively; harmonic beam components were less than 1% using these monochromators. All experiments were performed in transmission mode, and beam intensities were measured using a series of three ionization chambers filled with a mixture of N 2 and Ar at ambient temperature and a pressure of 1 bar. The photon energies were calibrated by measuring the beam transmission, simultaneously with the sample, through a thin film of metallic foil (Au, Pd, or Pt) placed between the second and third ionization chambers. XAS spectra were measured for Au 50 Pd 50 NaLTA and Pd 65 Pt 35 NaLTA samples; spectra of bimetallic samples were collected at the absorption edges of both metals present (Au-L 3 and Pd—K, or Pd—K and Pt-L 3 ) in a range of 200 eV before and 1000 eV after the corresponding edge. The samples (0.1 g each) were prepared first with treatment in flowing 10% H 2 /Ar (1.67 cm 3 g −1 s −1 ) at 573 K (0.033 K s −1 ) for 1 h, then cooled to ambient temperature under Ar flow (1.67 cm 3 g −1 s −1 ). They were then transferred under Ar at atmospheric pressure and ambient temperature to an XAS cell hermetically sealed with KAPTON® windows. The samples were stored in this cell for ˜10 h, after which the XAS spectra were collected at ambient temperature.
[0033] Extended X-ray absorption fine structure (EXAFS) data analyses reported herein was carried out using the IFFEFIT package (Athena, Artemis). Background subtraction and edge-step normalization of the spectra were performed using the AUTOBK algorithm implemented in Athena. Structural information for the metals, including coordination numbers (N), interatomic distances (D), and their Debye-Waller factors (σ 2 ), were obtained from Artemis using nonlinear least squares fits of the Fourier transformed data in r-space, with theoretical amplitudes and phase shifts for all single scattering paths calculated by FEFF (see S. I. Zabinsky et al., Phys. Rev. B 1995, 52, 2995-3009). All data fits were conducted between 1.0-3.0 Å in r-space and were generated by Fourier filtering the k 3 -weighted EXAFS over 2-13 Å −1 in k-space with a Hanning window. The theoretical scattering path amplitudes and phase shifts used in these fits were calculated from crystallographic structures of either monometallic lattices (for Au—Au, Pd—Pd, and Pt—Pt paths) or mixed phase lattices (for Pd—Au and Pd—Pt paths), all of which are face-centered cubic (FCC). The first coordination shell of the absorbing atom in these bimetallic lattices was filled with like or dislike atoms in proportions that reflect the molar ratio of metals measured in each sample by ICP. EXAFS data extracted from bimetallic samples were fit simultaneously at both metal edges, thus ensuring consistency in the interatomic distances and Debye-Waller factors of bimetallic paths. Photoelectron single scattering by low-Z species (O and S), with theoretical amplitudes and phases calculated from metal oxide (PdO, PtO) or metal sulfide (PdS, PtS, Au 2 S 3 ) crystal structures, were also included in the fits to examine the contribution of these nonmetallic bonds to the EXAFS. Passive reduction factors (S 0 2 ) for each metal (Au: 0.95, Pd: 0.83, Pt: 0.96) were obtained from single scattering fits to the EXAFS spectra of the metal foils by constraining the coordination number to 12 in each case.
[0034] Metal contents in the synthesized and treated samples reported herein were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES) using a Perkin Elmer 5300 DV optical emission ICP analyzer.
Reaction Mixture
[0035] In general, the zeolite is synthesized by: (a) preparing a reaction mixture containing (1) a source of silicon oxide; (2) a source of aluminum oxide; (3) a source of a Group 1 or 2 metal (X); (4) hydroxide ions; (5) sources of a first metal precursor (M 1 ) and a second metal precursor (M 2 ) of Groups 8 to 12 of the Periodic Table of the Elements; (6) a ligating agent (L) having a thiol group and an alkoxysilyl group; and (7) water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the zeolite.
[0036] The relative amounts of reagents added to the reactor to form the reaction mixture will also vary in a known manner according to the target zeolite. Thus, in one embodiment, where the target zeolite has the LTA framework type, the composition of the reaction mixture from which the zeolite is formed, in terms of mole ratios, is identified in Table 1 below:
[0000] TABLE 1 Reactants Useful Exemplary SiO 2 /Al 2 O 3 ≧1 1 to 500 X/SiO 2 0.25 to 1.00 0.25 to 1.00 OH/SiO 2 0.25 to 1.00 0.25 to 1.00 (M 1 + M 2 )/SiO 2 0.005 to 0.025 0.005 to 0.020 L/SiO 2 0.02 to 0.25 0.02 to 0.20 H 2 O/SiO 2 ≧50 50 to 100
wherein compositional variables X, M 1 , M 2 , and L are as described herein above.
[0037] Suitable sources of silicon oxide include fumed silica, colloidal silica, precipitated silica, alkali metal silicates, and tetraalkyl orthosilicates.
[0038] Suitable sources of aluminum oxide include hydrated alumina and water-soluble aluminum salts (e.g., aluminum nitrate).
[0039] Sources of Group 1 or 2 metal include metal oxide, metal chloride, metal fluoride, metal sulfate, metal nitrate, or metal aluminate.
[0040] Combined sources of two or more of the components X, Al 2 O 3 and SiO 2 can also be used and can include, for example, sodium aluminate, clays or treated clays (e.g., metakaolin), and aluminosilicate zeolites (e.g., BEA and FAU framework type aluminosilicate zeolites).
[0041] The metal of the first and second metal precursors may be selected from Fe, Ru, Os, Co, Rh, Pd, Pt, Cu, Ag, and Au. Suitably, the metal of the first and second metal precursors may be selected from Pd, Pt, and Au. The second metal precursor is different from the first metal precursor. The metal precursor can be an amine or ethylene diamine complex. The metal precursor can also be a ligated metal.
[0042] The ligating agent is an organic compound having a thiol group and an alkoxysilyl group. Suitable ligating agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, (mercaptomethyl)dimethylethoxysilane, and mercaptomethyltrimethoxysilane.
[0043] Without being bound by any particular theory, it is believed that the thiol group (—SH) in the ligating agent binds strongly to late transition metals to form stable metal-sulfur adducts via ligand-exchange. These metal-sulfur adducts are resistant to formation of bulk metal hydroxides even at the high pH required for zeolite synthesis. Moreover, the alkoxysilyl group of the ligating agent undergoes hydrolysis in alkaline media to form covalent Si—O—Si or Si—O—Al bonds with nucleating zeolite structures, thereby forming linkages that enforce metal encapsulation during subsequent zeolite crystal growth.
[0044] The mole ratio of ligating agent to the first and second metal precursors [L/(M 1 +M 2 )] in the reaction mixture may range from 4 to 10 (e.g., from 5 to 8).
[0045] The reaction mixture may also contain seeds of a zeolite material desirably in an amount of from 0.01 to 10,000 ppm by weight (e.g., from 100 to 5000 ppm by weight) of the reaction mixture.
[0046] The reaction mixture is substantially free of organotemplate materials, wherein “substantially” as employed herein with respect to the amount of one or more organotemplates contained in the one or more materials used in a synthetic process indicates an amount of 0.001 wt. % or less (e.g., 0.0005 wt. % or less, or 0.00001 wt. %) of one or more organotemplates. The amounts of one or more organotemplates, if at all present in any one of the materials used in the synthetic process, may also be denoted as “impurities” or “trace amounts” within the meaning of the present disclosure. The term “organotemplate” as employed in the present disclosure designates any conceivable organic material which is suitable for template-mediated synthesis of a zeolite material, such as a zeolite having a framework type selected from the group consisting of CHA, ERI, EUO, FER, GIS, HEU, KFI, LEV, LTA, MEL, MFI, MFS, MTT, MTW, RTH, SOD, TON, and combinations thereof (e.g., a zeolite having the LTA framework type).
[0047] The reaction mixture can be prepared either batch wise or continuously. Crystal size, morphology and crystallization time of the zeolite described herein can vary with the nature of the reaction mixture and the crystallization conditions.
[0048] Crystallization and Post-Synthesis Treatment
[0049] Crystallization of the zeolite disclosed herein can be carried out under either static, tumbled or stirred conditions in a suitable reactor vessel, such as polypropylene jars or Teflon-lined or stainless steel autoclaves, at a temperature of from about 85° C. to 180° C. for a time sufficient for crystallization to occur at the temperature used, e.g., from 5 to 250 hours. The reaction mixture may be reacted under autogenous pressure, or optionally in the presence of a gas such as nitrogen.
[0050] Once the zeolite crystals have formed, the solid product is separated from the reaction mixture by standard mechanical separation techniques such as centrifugation or filtration. The crystals are water-washed and then dried to obtain the as-synthesized zeolite crystals. The drying step is typically performed at a temperature below 200° C.
[0051] The as-synthesized zeolite is then subjected to sequential oxidative and reductive treatments in the presence of oxygen and hydrogen, respectively. Sequential oxidative and reductive treatment of the zeolite results in the formation of bimetallic clusters, which remain narrowly distributed in size. The reduced material is typically passivated prior to exposure to ambient air.
[0052] Conditions for oxidative and reductive treatment include heating the zeolite to a temperature from 250° C. to 500° C. for an appropriate period of time (e.g. 0.5 to 5 h, or 1 to 3 h) under ambient pressure. Treatment of the as-synthesized zeolite under oxidative conditions also facilitates removal of any of the organic moieties used in its synthesis.
[0053] Characterization of the Zeolite
[0054] The zeolite formed by the process described herein may be a small-pore zeolite or a medium-pore zeolite. A small-pore size zeolite has an average pore size from 3 Å (0.3 nm) to less than 5.0 Å (0.5 nm) and includes, for example, CHA, ERI, GIS, KFI, LEV, LTA, RTH, and SOD framework type zeolites (IUPAC Commission of Zeolite Nomenclature). A medium-pore size zeolite has an average pore diameter 5 Å (0.5 nm) to 7 Å (0.7 nm) and includes for example, EUO, FER, HEU, MEL, MFI, MFS, MTT, MTW, and TON framework type zeolites (IUPAC Commission of Zeolite Nomenclature). In one embodiment, the zeolite formed by the processed described herein has the LTA framework type.
[0055] The apertures of small- and medium-pore zeolites preclude conventional post-synthetic encapsulation protocols via ion exchange from aqueous media, which require migration of solvated metal-oxo oligomers that cannot diffuse through the small apertures in such zeolites (e.g., divalent and higher in small-pore zeolites and trivalent and higher in medium-pore zeolites).
[0056] The encapsulated bimetallic clusters of the zeolite disclosed herein may be characterized as having a small size. The encapsulated clusters may have a surface weighted mean cluster diameter d TEM of 1.0 to 2.0 nm (e.g., 1.1 to 1.9 nm, 1.2 to 1.8 nm, or 1.3 to 1.7 nm). The surface area weighted mean cluster diameter is determined via TEM (see Equation 1).
[0057] The encapsulated bimetallic clusters of the zeolite disclosed herein may be characterized as having a narrow size distribution. The encapsulated clusters may have a dispersity index of 1.50 or less (e.g., 1.00 to 1.50, 1.00 to 1.25, 1.00 to 1.15, 1.05 to 1.50, 1.05 to 1.25, or 1.05 to 1.15). The dispersity index is computed as the surface averaged cluster diameter divided by the number averaged diameter (see Equation 2).
[0058] The collective amount of metals of Groups 8 to 12 can be from 0.1 to 5.0 wt. % (e.g., 0.1 to 2.5 wt. %, 0.1 to 2.0 wt. %, 0.1 to 1.5 wt. %, 0.3 to about 5.0 wt. %, or 0.3 to 2.5 wt. %, 0.3 to 1.5 wt. %, 0.5 to 5.0 wt. %, 0.5 to 2.5 wt. %, or 0.5 to 1.5 wt. %), based on the total weight of the composite.
[0059] The metals in the encapsulated bimetallic clusters of the zeolite disclosed herein may have a metal ratio of the first metal to the second metal of from 99:1 to 1:99 (e.g., 95:5 to 5:95, 75:25 to 25:75, or 60:40 to 40:60). The bimetallic metals may be selected from Groups 8 to 12 of the Periodic Table of Elements. The bimetallic metals may consist of gold and palladium, gold and platinum, or palladium and platinum.
[0060] Processes Using the Zeolite
[0061] The zeolite of the present disclosure can be used as a catalyst to catalyze a wide variety of organic compound conversion processes including many of present commercial/industrial importance. Examples of organic conversion processes which may be catalyzed by the present zeolite include alkylation, (hydro)cracking, disproportionation, (hydro)isomerization, oligomerization, and conversion of oxygenates to one or more olefins, particularly ethylene and propylene.
[0062] The zeolite of the present disclosure can be used as a catalyst for the catalytic reduction of nitrogen oxides in a gas stream.
[0063] As in the case of many catalysts, it may be desirable to incorporate the present zeolite with another material resistant to the temperatures and other conditions employed in organic conversion processes. Such materials include active and inactive materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and/or metal oxides such as alumina. The latter may be either naturally occurring, or in the form of gelatinous precipitates or gels, including mixtures of silica and metal oxides. Use of a material in conjunction with the present zeolite, i.e., combined therewith or present during synthesis of the material, which is active, tends to change the conversion and/or selectivity of the catalyst in certain organic conversion processes. Inactive materials suitably serve as diluents to control the amount of conversion in a given process so that products can be obtained in an economic and orderly manner without employing other means for controlling the rate of reaction. These materials may be incorporated into naturally occurring clays (e.g., bentonite and kaolin) to improve the crush strength of the catalyst under commercial operating conditions. These materials (i.e., clays, oxides, etc.) function as binders for the catalyst. It is desirable to provide a catalyst having good crush strength because in commercial use it is desirable to prevent the catalyst from breaking down into powder-like materials. These clay and/or oxide binders have been employed normally only for the purpose of improving the crush strength of the catalyst.
[0064] Naturally occurring clays that can be composited with the present zeolite include those in the montmorillonite and kaolin family, which families include the subbentonites, and the kaolins commonly known as Dixie, McNamee, Georgia and Florida clays or others in which the main mineral constituent is halloysite, kaolinite, dickite, nacrite, or anauxite. Such clays can be used in the raw state as originally mined or initially subjected to calcination, acid treatment or chemical modification. Binders useful for compositing with the present molecular sieve also include inorganic oxides, such as silica, zirconia, titania, magnesia, beryllia, alumina, and mixtures thereof.
[0065] In addition to the above mentioned materials, the present zeolite can be composited with a porous matrix material such as silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania as well as ternary compositions such as silica-alumina-thoria, silica-alumina-zirconia silica-alumina-magnesia and silica-magnesia-zirconia.
[0066] The relative proportions of the present zeolite and inorganic oxide matrix may vary widely, with the content of the present zeolite ranging from 1 to 90 wt. % (e.g., 2 to 80 wt. %) of the composite.
Examples
[0067] The following illustrative examples are intended to be non-limiting.
Preparation of Zeolite-Encapsulated Au, Pd, Pt and Bimetallic AuPd, AuPt, and PdPt Clusters
[0068] Preparation procedures for bimetallic metal-encapsulated Na-LTA zeolites (M 1 M 2 NaLTA, where M 1 and M 2 are Au, Pd, or Pt) were adapted from hydrothermal synthesis protocols for their monometallic counterparts (see, M. Choi et al., J. Am. Chem. Soc. 2010, 132, 9129-9137; and T. Otto et al., J. Catal. 2016, 339, 195-208) and modified to incorporate multiple metal cation species into zeolite synthesis gels. Synthetic protocols for the three monometallic samples (AuNaLTA, PdNaLTA, and PtNaLTA) and bimetallic samples (Au n Pd 100-n NaLTA, Au n Pt 100-n NaLTA, and Pd n Pt 100-n NaLTA, where 0≦n≦100 and indicates the relative % molar quantity of included metal) follow analogous procedures, which differ only in the identity and fractional amounts of noble metal cations added to each gel.
[0069] In the synthesis of Au 50 Pd 50 NaLTA, for example, the protecting ligand 3-mercaptopropyl-trimethoxysilane (0.96 g) and NaOH (4.8 g) were first dissolved in deionized H 2 O (17.9 MΩ resistance; 18 mL) within an open 125 mL polypropylene bottle and magnetically stirred (6.7 Hz; 8 h). Aqueous solutions of HAuCl 4 .3H 2 O (0.156 g in 9 mL deionized H 2 O) and Pd(NO 3 ) 2 (0.118 g in 9 mL deionized H 2 O) were then added simultaneously and dropwise to the basic ligand solution over a period of 0.5 h as the mixture was continuously agitated with a magnetic bar (6.7 Hz). Colloidal silica (10.67 g, LUDOX® AS-30) was then added to the polypropylene bottle, which was sealed with its cap and heated to 353 K for 0.5 h, also with continuous magnetic bar agitation (6.7 Hz). An aqueous solution of NaAlO 2 (6.0 g in 18 mL deionized H 2 O) was then added dropwise to the silica, ligand, and metal cation solution and allowed to mix by magnetic stirring (6.7 Hz) for 2 h at ambient temperature; this mixing led to a homogeneous synthesis gel with molar ratios of 1.7 SiO 2 /1 Al 2 O 3 /3.2 Na 2 O/110 H 2 O/0.013 Au/0.013 Pd/0.156 ligand. Finally, the gel was heated to 373 K with continuous magnetic stirring (6.7 Hz) for 12 h to form Au 50 Pd 50 NaLTA. The solids formed by this process were filtered (Pyrex 3606 fritted funnel, 4-5.5 μm), washed with deionized H 2 O until the rinse liquids reached a pH 7-8, and treated in a convection oven at 373 K for 8 h. The solids were then heated in flowing dry air (1.67 cm 3 g −1 s −1 ) from ambient temperature to 623 K (0.033 K s −1 ) and held for 2 h, cooled to ambient temperature, and then heated to 623 K (0.033 K s −1 ) in flowing H 2 (1.67 cm 3 g −1 s −1 ) and held for 2 h. A final heating procedure in air (1.67 cm 3 g −1 s −1 ) at 723 K (0.033 K s −1 ) was then conducted for 2 h.
[0070] The molar ratio of the two metals present in each bimetallic sample was adjusted by varying the relative amounts of noble metal cation precursors (HAuCl 4 .3H 2 O, Pd(NO 3 ) 2 , or H 2 PtCl 6 ) added to the gel, while keeping the total metal content fixed at 1.0 wt. % theoretical loading. Monometallic metal-zeolite samples were also synthesized with 1.0 wt. % theoretical loading. The molar ratio of 3-mercaptopropyl-trimethoxysilane to the added metals was kept fixed at 6 for each sample synthesis, regardless of the identity of the metal cations used.
[0071] The air and H 2 treated metal-NaLTA samples were exchanged with Ca 2+ ions to convert the host zeolite CaLTA before use in infrared studies. The calcium exchange was performed by adding monometallic or bimetallic metal-zeolite samples (1-5 g) to an aqueous 1 M solution of CaCl 2 .2H 2 O (1 g zeolite per 100 mL) and stirring magnetically (6.7 Hz) at ambient temperature for 8 h. The exchange was repeated ten times to ensure full Ca 2+ exchange, and the solids were filtered and washed with deionized water (1500 mL g −1 ), and finally treated in ambient air within a convection oven at 373 K for 12 h.
Synthesis of Au, Pd, and Pt Clusters on Mesoporous SiO 2
[0072] Au, Pd, and Pt clusters dispersed on mesoporous SiO 2 were synthesized and used as oxidative dehydrogenation (ODH) catalysts for comparison with the bimetallic clusters supported by zeolites. Pd/SiO 2 and Pt/SiO 2 catalysts were prepared with incipient wetness impregnation using aqueous solutions of Pd (NH 3 ) 4 Cl 2 and H 2 PtCl 6 , respectively. These silica-supported clusters were treated in ambient air, flowing dry air, and flowing H 2 using the same procedures as the metal-zeolite samples.
[0073] Au clusters dispersed on SiO 2 (Cab-O-Sil, HS-5, 310 m 2 g −1 were prepared using an Au(en) 2 Cl 3 (en=ethylenediamine) complex.
Characterization of Zeolite Metal Loading and Phase Purity
[0074] LTA-encapsulated metal nanoparticle samples were synthesized with Au and Pd (Au n Pd 100-n NaLTA), Au and Pt (Au n Pt 100-n NaLTA), or Pd and Pt (Pd n Pt 100-n NaLTA) and a broad range of molar ratios for each metal pair. The quantities of metal precursors added during the synthesis were selected to achieve total metal loadings of 1.0 wt. % in each sample, assuming complete incorporation of the added metal into the recovered solids. The nominal molar ratios of metal species are denoted by the subscripts for each sample (e.g., Au 67 Pd 33 NaLTA; 67 Au: 33 Pd molar ratios).
[0075] Table 1 summarizes the bimetallic samples synthesized as well as the ultimate metal content and composition of these samples, as measured by ICP. Elemental analysis confirms that actual metal loadings and compositions are similar to their nominal values in all cases, consistent with complete incorporation of the added metal species into the synthesized solids. Without being bound by any particular theory, it is believed that such complete incorporation may be attributed to the metal cations' attached ligands, which covalently anchor to solidifying silicates and preclude the solvation of metal precursors in the supernatant solution that is ultimately removed by filtration.
[0000]
TABLE 1
Wt. %
d TEM (b)
Sample
Metal (a)
Metal Ratio (a)
nm
DI (c)
AuNaLTA
1.1
—
2.3 ± 0.4
1.09
PdNaLTA
1.0
—
1.6 ± 0.3
1.10
PtNaLTA
1.1
—
1.3 ± 0.3
1.17
Au 67 Pd 33 NaLTA
1.0
65 Au:35 Pd
1.7 ± 0.3
1.09
Au 50 Pd 50 NaLTA
0.9
54 Au:46 Pd
1.5 ± 0.3
1.08
Au 33 Pd 67 NaLTA
0.7
32 Au:68 Pd
1.5 ± 0.3
1.11
Au 67 Pt 33 NaLTA
1.1
62 Au:38 Pt
1.4 ± 0.3
1.15
Au 50 Pt 50 NaLTA
0.8
52 Au:48 Pt
1.4 ± 0.3
1.09
Au 33 Pt 67 NaLTA
1.2
62 Au:38 Pt
1.3 ± 0.2
1.07
Pd 80 Pt 20 NaLTA
1.1
80 Pd:20 Pt
1.4 ± 0.3
1.09
Pd 65 Pt 35 NaLTA
1.1
61 Pd:39 Pt
1.3 ± 0.2
1.06
Pd 20 Pt 80 NaLTA
1.0
24 Pd:76 Pt
1.3 ± 0.2
1.05
(a) Analyzed by inductively-coupled plasma optical emission spectroscopy.
(b) Surface area weighted mean cluster diameter determined via TEM (Equation 1).
(c) Dispersity Index computed as the surface averaged cluster diameter divided by the number averaged diameter (Equation 2).
[0076] X-Ray diffractograms of the synthesized solids, collected after treatments in O 2 (623 K) and then H 2 (623 K), verified the presence of the intended LTA structures in all samples; representative diffractograms are shown in FIG. 1 . Zeolite crystallinities were greater than 95% for each sample, as determined from the integrated areas of the three most intense Bragg lines, using metal-free NaLTA as a standard. Diffraction lines for bulk metal phases (Au, Pd, or Pt) were absent from these samples, and their crystallinity was unchanged by treatments in air or H 2 at elevated temperature (823 K). Thus, it can be concluded that the synthesized zeolites are crystalline, thermally-stable, and free of large metal crystallites (>10 nm), which would have exhibited their characteristic Bragg lines in the diffractograms.
Assessment of Encapsulated Metal Cluster Size Distributions and Thermal Stability
[0077] TEM micrographs were used to assess the size, location, and thermal stability of metal structures formed by hydrothermal synthesis and post synthetic air and H 2 treatments of the crystallized zeolites. Previous studies have shown that these synthetic protocols, implemented with only a single metal (Au, Pd, or Pt), lead to highly dispersed monometallic clusters free of synthetic debris and located predominantly within the zeolite voids. Clusters form in these zeolites as a result of the H 2 treatment, during which isolated metal cations are reduced and subsequently migrate throughout the framework to form agglomerates; the ultimate size of these agglomerates is dictated by the mobility of the metal atoms during this critical reduction step, with greater mobility (e.g. as a result of higher treatment temperature) leading to larger nanoparticles. FIGS. 2A-2F show TEM micrographs and particle size distributions for these monometallic clusters, as well as a selection of the bimetallic samples considered in this study. The total metal content in each sample is 1 wt. %. Table 1 also summarizes the TEM-derived surface-averaged cluster diameters ( d TEM ; Equation 1) and dispersity indices (DI; Equation 2) for each of the synthesized Au n Pd 100-n NaLTA, Au n Pt 100-n NaLTA, and Pd n Pt 100-n NaLTA samples.
[0078] The surface-averaged cluster diameter of monometallic samples (AuNaLTA: 2.3 nm, PdNaLTA: 1.6 nm, PtNaLTA: 1.3 nm; Table 1) varies inversely with the Tammann temperature of the embedded metal (Au: 668 K, Pd: 914 K, Pt: 1022 K), consistent with the formation of relatively larger clusters by metals with greater mobility. Bimetallic samples gave surface-averaged cluster sizes (e.g. Au 50 Pd 50 NaLTA: 1.5 nm, Au 50 Pt 50 NaLTA: 1.4 nm, and Pd 65 Pt 35 NaLTA: 1.3 nm; Table 1) similar to their most stable single-metal counterparts (i.e., the metal with the higher Tammann temperature), and exhibited cluster size distributions that were both monodisperse (DI: 1.05-1.15; Table 1) and unimodal ( FIGS. 2A-2F ). The addition of Pd to Au, Pt to Au, and Pt to Pd leads to smaller nanoparticle sizes relative to monometallic Au or Pd, consistent with inhibited cluster growth processes brought forth by the addition of a second metal with higher Tammann temperature. Such enhancements in the metal cluster stability generally vary in a highly non-linear fashion with composition; consequently, even bimetallic samples with relatively high Au content (e.g., Au 67 Pd 33 : 1.7 nm, Au 67 Pt 33 : 1.4 nm) exhibited cluster diameters disproportionately smaller than monometallic AuNaLTA (2.3 nm). The nearly monodisperse size distributions in these bimetallic samples implies that their clusters are uniformly distributed in composition; nominally bimetallic clusters that are heterogeneously distributed in composition, by contrast, would typically show a broad range of cluster sizes because of the differing thermal stabilities of their constituent metals. Mixtures of two types of monometallic clusters in a given same sample, for instance, are expected to exhibit bimodal size distributions with poor monodispersity (i.e., DI>1.5), and surface-averaged cluster diameters that reflect the composition-weighted mean value of the corresponding monometallic samples. The small cluster diameters and monodisperse size distributions of the LTA-encapsulated bimetallic samples therefore suggest the predominant presence of alloy nanoparticles.
[0079] The stability of monometallic Au and Au-bimetallic clusters was examined and compared during treatment in flowing air by heating to final temperatures between 623 and 873 K (0.033 K s −1 ) and holding for 5 h. Previous studies of LTA-encapsulated Pt and Pd clusters revealed that the confining environment of the zeolite frameworks entirely precludes agglomeration of these metals in air up to 873 K, while monometallic Au clusters retain their size to approximately 823 K (see, M. Choi et al., J. Am. Chem. Soc. 2010, 132, 9129-9137; and T. Otto et al., J. Catal. 2016, 339, 195-208). The TEM-derived surface-averaged cluster diameters ( d TEM ; Equation 1) of AuNaLTA, Au 50 Pd 50 NaLTA, and Au 50 Pt 50 NaLTA are shown in FIG. 3 as a function of the final air treatment temperature. Cluster diameters of all samples (AuNaLTA: 2.3 nm, Au 50 Pd 50 NaLTA: 1.5 nm, Au 50 Pt 50 NaLTA: 1.4 nm) were unchanged by treatment at or below 773 K, though the monometallic Au clusters increased in size by 65% (to 3.8 nm) after treatment at 873 K. The alloyed clusters, by contrast, increased only slightly in size after treatment at 873 K; clusters in Au 50 Pd 50 NaLTA increased in size by 20% to 1.8 nm, and those in Au 50 Pt 50 NaLTA increased by 14% to 1.6 nm. The dispersity index (DI) values (Equation 2) of these samples also increased as a result of this treatment at 873 K. The DI of clusters in AuNaLTA rose significantly from 1.07 to 1.62, while the bimetallic clusters exhibited much smaller increases (Au 50 Pd 50 NaLTA: 1.09 to 1.23, Au 50 Pt 50 NaLTA: 1.09 to 1.17) and thus remained relatively monodisperse (DI<1.5). It is concluded that the admixture of Au with Pd or Pt, with higher Tamman temperatures, acts to decrease the mobility and thus stabilize Au species, conferring dramatic improvements in cluster stability compared to monometallic Au. These clusters benefit from resistance to thermal sintering as a result of this alloying effect in addition to the strong cluster stabilization provided by the zeolite framework, which renders encapsulated clusters significantly more resistant to agglomeration than those dispersed on mesoporous supports.
UV-Visible Evidence for Intracluster Metal Mixing in AuPd and AuPt Bimetallics
[0080] UV-vis spectra of AuNaLTA, Au n Pd 100-n NaLTA, and Au n Pt 100-n NaLTA were used to confirm the absence of monometallic Au clusters in the crystallized and reduced bimetallic samples. Such monometallic Au clusters, as well as core-shell bimetallic structures with pure Au on the surface, would exhibit localized surface plasmon resonance (LSPR) absorption bands in the range 500-600 nm. Monometallic Pt and Pd clusters or Au-bimetallic clusters, by contrast, show no distinguishing absorption features in the UV-visible range. The presence of an LSPR band thus serves as a diagnostic for Au clusters greater than 2 nm in diameter, the minimum particle size at which Au exhibits plasmon resonance.
[0081] UV-visible spectra of AuNaLTA, Au 67 Pd 33 NaLTA, Au 67 Pt 33 NaLTA, and 2:1 physical mixtures (by moles of metal) of AuNaLTA and PtNaLTA or AuNaLTA and PdNaLTA are shown in FIGS. 4A and 4B .
[0082] AuNaLTA samples and physical mixtures of monometallic AuNaLTA and PdNaLTA or AuNaLTA and PtNaLTA each showed an LSPR absorption band, consistent with the presence of monometallic Au clusters greater than 2 nm in diameter ( d TEM =2.3 nm; FIGS. 2A-2F ) in each sample. The absorption wavelength of these plasmon bands (˜506 nm) is characteristic of Au nanoparticles smaller than 5 nm in diameter, but is insensitive to cluster size below this threshold. The bimetallic and monometallic Pd and Pt samples, by contrast, exhibited only indefinite background features in the relevant range for plasmon resonance (500-600 nm), rather than distinct absorption bands indicative of monometallic Au. Pd or Pt can contribute slightly to diffuse background absorption in the visible range; consequently, the slight differences in the background absorption of the UV-Vis spectra, which are blanked with metal-free NaLTA, can be attributed to differing contents of these metals in each sample. The lack of LSPR band features in Au 67 Pd 33 NaLTA and Au 67 Pt 33 NaLTA confirms the substantive absence of monometallic Au clusters ≧2 nm in diameter, even though ICP analysis confirms the presence of Au in a 2:1 molar ratio with Pt or Pd (Table 1). Au-bimetallic samples with lower Au content (i.e., Au/Pd=1, Au/Pd=0.5, Au/Pt=1, and Au/Pt=0.5) similarly lacked LSPR absorption bands. These spectra are therefore consistent with bimetallic clusters that are homogeneously distributed in composition, even when enriched with less stable Au metal. The surface-averaged cluster diameters of Au 67 Pd 33 NaLTA (1.7 nm) and Au 67 Pt 33 NaLTA (1.4 nm), however, are near the lower size limit for plasmon resonance (2 nm); only 7% and 2% of the clusters in these samples, respectively, are at or above this limit. Monometallic Au clusters, if present in the bimetallics, are expected to preferentially comprise these larger nanoparticles because of the relatively low Tammann temperature of Au, though it is unclear whether such small concentrations would have been evident in UV-Vis spectra via LSPR absorption. It is therefore concluded that the absence of LSPR bands in Au-bimetallic samples is consistent with small cluster sizes and metal alloying, but cannot independently confirm this alloying.
Infrared Evidence for Metal Alloying and Intracluster Metal Atom Mobility Upon CO Binding
[0083] The arrangement of atoms in bimetallic clusters is often understood and categorized in the context of core-shell structures, intimately mixed intermetallic phases with ordered binding arrangements, or random intracluster distributions of each metal species. These specific structures, however, are rarely preserved in practice because alloy clusters undergo dynamic restructuring in response to changes in their environment, including the binding of adsorbates, temperature changes, or metal-support interactions. Here, the aim is to induce this restructuring in the zeolite-encapsulated bimetallic clusters by exposing them to CO. Infrared (IR) spectra of the adsorbed CO are used to deduce the surface compositions of bimetallic clusters and to probe any changes in surface compositions that result from intracluster restructuring.
[0084] IR spectra of CO adsorbed on metal clusters were collected for monometallic and bimetallic samples synthesized and prepared as described herein above; the NaLTA host zeolites (0.42 nm apertures) were exchanged with Ca 2+ to form CaLTA (0.50 nm apertures) before these measurements in order to improve the accessibility of CO to encapsulated metal clusters. Au n Pd 100-n CaLTA and Au n Pt 100-n CaLTA bimetallic samples were first treated in H2 (20 kPa) at 573 K for 1 h before cooling to sub-ambient temperature (278 K and 263 K, respectively) in He (100 kPa). This heating procedure favors the enrichment of bimetallic cluster surfaces with the lower surface energy component, in both cases Au, which tends to diffuse to the surface in order to minimize the total Gibbs free energy of the nanoparticles. The cooled samples were then exposed to CO (1.0 kPa) and IR spectra were collected. Such spectra are predicted to reflect CO adsorption onto bimetallic surfaces enriched with Au. Each sample was next heated to 353 K under 1.0 kPa CO for 0.5 h and cooled back to 278 K or 263 K for the collection of a second spectrum. This heating with exposure to CO is intended to draw Pt or Pd atoms to the surface, thus decreasing the Au surface concentration of the clusters and leading to an apparent hysteresis effect when the second absorption spectrum is collected. Such intracluster rearrangement is driven by the higher binding energy of CO on Pt (atop: 136 kJ mol −1 ) or Pd (atop: 94 kJ mol −1 ; bridged: 146 kJ mol −1 ) relative to Au (atop: 50 kJ mol −1 ), which favors the displacement of surface Au atoms by the more strongly binding metal to decrease the cluster free energy. The mild heating to 353 K was applied to increase the rate of intracluster metal diffusion and more rapidly induce this restructuring. Clear differences in the CO IR absorption before and after this intermittent heating in CO thus provide evidence that the clusters in Au n Pd 100-n CaLTA and Au n Pt 100-n CaLTA are indeed bimetallic. The magnitude of the hysteresis effect is expected to be small for Pd n Pt 100-n CaLTA samples, because differences in CO binding energies on Pd and Pt are relatively minor. Metal alloying in these samples was instead assessed using CO IR spectra collected for a wide variety of metal compositions and also using EXAFS analysis.
[0085] IR spectra of CO adsorbed on 1 wt. % (total metal) Au n Pt 100-n CaLTA samples (for n=0, 33, 50, 67, and 100), measured under 1.0 kPa CO at 263 K before and after intermittent heating in CO at 353 K, are shown in FIGS. 5A-5B . Monometallic Au ( FIG. 5A ) and Pt ( FIG. 5B ) samples exhibit absorption bands at 2120 cm −1 and 2070 cm −1 respectively, which correspond to atop adsorption of CO on Au and Pt. CO bridged bonding absorption bands on Pt (1800-1900 cm −1 ) are weak and undiscernible. The integrated intensity of the Pt—CO band in PtCaLTA is greater than that of the Au—CO band in AuCaLTA by a factor of 18. This difference in the integrated band areas reflects the relatively high intensity of Pt—CO bands (via high absorption cross-section) and the slightly higher density of surface metal atoms in PtCaLTA (0.005 mol surf-Pt g −1 ) compared to AuCaLTA (0.003 mol surf-Au g −1 ). Pt—CO bands, evident in each bimetallic sample spectrum, FIGS. 5C-5E , increase monotonically in intensity with increasing Pt content, consistent with increasing concentrations of surface Pt atoms. A distinct Au—CO band is visible in the Au-rich bimetallic sample (Au 67 Pt 33 CaLTA), but becomes muddled or indistinguishable at lower Au/Pt ratios. This weakening of the Au—CO band intensity can be attributed to the decreasing overall Au content, the relatively small intensity of Au—CO bands relative to Pt—CO, and the preferential adsorption of CO onto more strongly binding Pt atoms in bimetallic clusters. Each of these contributing effects to the decreasing Au—CO band intensity is expected to become more dramatic as the Pt/Au ratio increases, and together lead to the near complete disappearance of the Au—CO band when Pt/Au=2. Intermittent heat treatment of the Pt—Au bimetallics in CO at 353 K leads to significant hysteresis in the IR absorbance for each of the bimetallic samples, while the IR spectra for monometallic Pt and Au samples remain unchanged by this treatment. This intervening thermal treatment leads to increases in the intensity of the Pt—CO bands in the alloy samples, consistent with the displacement of surface Au atoms by more strongly CO-binding Pt atoms. The fractional increase in the Pt—CO band intensity caused by this restructuring decreases monotonically with increasing Pt to Au molar ratios (fractional increases of 20%, 15% and 9% for Pt/Au=0.5, 1, and 2, respectively). This trend is consistent with the expectation that samples with relatively more Pt-rich clusters should undergo less dramatic fractional changes in their Pt surface concentration during restructuring. These data, taken together, show compelling evidence of intracluster restructuring and are consistent with the predominant presence of alloy nanoparticles within the AuPt bimetallic samples.
[0086] IR spectra of CO adsorbed on 1 wt. % (total metal) Au n Pd 100-n CaLTA samples (for n=0, 33, 50, 67, and 100), measured under 1.0 kPa CO at 278 K before and after intermittent heating in CO at 353 K, are shown in FIGS. 6A-6E . AuCaLTA ( FIG. 6A ) shows a weak absorption band at 2130 cm −1 corresponding to atop adsorption of CO on Au, while PdCaLTA ( FIG. 6B ) exhibits significantly more intense absorption bands at 2090 cm −1 and 1930 cm −1 , which can be assigned to atop binding and ridged (vicinal) binding of CO onto Pd, respectively. The relatively weak intensity of the Au—CO band likely results from the incomplete coverage of Au surfaces at the conditions of the measurement and the small absorption cross section of CO on Au surfaces. Atop and bridged Pd—CO bands are present in each bimetallic sample spectra, while Au—CO bands are not clearly distinguishable. The poor intensity and resolution of these Au—CO bands in the bimetallic samples may result from the preferred adsorption of CO onto more strongly binding Pd atoms in bimetallic clusters, or the partial overlap of these Au—CO bands with much more intense atop Pd—CO bands. The intensity of the Pd—CO bands increase monotonically with the Pd/Au ratio ( FIGS. 6C-6E ), consistent with increasing concentrations of surface Pd atoms as the total Pd content increases. The ratio of the integrated intensity (I) of the bridged Pd—CO band to that of the atop Pd—CO band (defined as □=I bridge /I atop ) also increases monotonically with the Pd to Au molar ratio. See FIG. 7 . □ values measured before intermittent heating in CO were 0.9, 1.4, 1.9, and 2.4 for Pd/Au=0.5, 1, 2, and ∞, respectively; α values measured after heating in CO similarly approached the value for pure Pd clusters, but were slightly larger in magnitude. This increasing preference for bridged CO binding on Pd reflects the decreasing concentration of surface Au atoms, which can dilute Pd atom domains on bimetallic clusters and decrease the fraction of vicinal Pd atoms required for bridged CO binding. Mixtures of monometallic Au and Pd clusters, in contrast, would be expected to maintain constant □ values with increasing Pd/Au ratios because of the absence of Pd surface dilution by Au. Heating of the bimetallic samples in CO at 353 K leads to changes in the IR absorption spectra, while the spectra of monometallic samples are unaffected by the same treatment. This treatment in CO leads to greater bridged Pd—CO band intensities for each bimetallic sample, consistent with increased fractions of vicinal Pd atoms brought forth by Pd migration to the cluster surfaces. Atop Pd—CO bands also decrease slightly in intensity following this treatment, which reflects the preference of CO molecules linearly bound on isolated Pd atoms to adopt more stable bridged bonding configurations when vicinal binding sites become available. These trends in the absorption spectra are therefore consistent with cluster alloying and suggest the absence of monometallic clusters in AuPd bimetallic samples.
[0087] The relatively facile restructuring observed for AuPt and AuPd clusters suggests that the bimetallic surfaces are free of strongly bound sulfur contaminants derived from the protecting ligands used in the synthesis. Such contaminants would tend to anchor to Pt or Pd surface atoms because of the high bond energies of Pt—S (233 kJ mol −1 ) and Pd—S (183 kJ mol −1 ) relative to Au—S (126 kJ mol −1 ). These surface-bound sulfur species, if present, would have led to diffuse Pt—CO and Pd—CO bands and also precluded intracluster restructuring because of their higher binding energies relative to CO. The apparent cleanliness of the metal surfaces is consistent with previous chemisorption and CO IR studies of LTA-encapsulated monometallic Pt, Pd, and Au clusters, which were shown to be free of contaminant species and rendered fully accessible after the post-synthetic air (623 K) and H 2 (623 K) treatments applied as described herein.
[0088] FIG. 8 shows IR spectra of CO adsorbed on metal clusters in Pd n Pt 100-n CaLTA samples (for n=100, 80, 65, 50, 20, and 0) at 313 K under 1 kPa CO. The absorption spectra of CO on monometallic Pt and Pd samples at 313 K closely resemble those collected at slightly lower temperatures (Pt—CO: 263 K, FIG. 5 ; Pd—CO: 278 K, FIG. 6 ). PtCaLTA exhibits an intense absorption band at 2070 cm −1 associated with atop CO adsorption, and monometallic Pd shows absorption bands at 2090 cm −1 and 1930 cm −1 , corresponding to atop and bridged CO binding, respectively. The addition of Pt to Pd leads to monotonic increases in the integrated intensity of the linearly bonded CO band and concomitant decreases in the bridged Pd—CO band. The ratio of the integrated intensities for these bands as a function of Pd content is shown in FIG. 9 . The increasing intensity of the atop CO band with the Pt/Pd ratio is consistent with increasing concentrations of Pt—CO surface complexes, which exhibit characteristically high IR absorption intensity. The accompanying decline in the Pd—CO bridged band intensity is an expected consequence of the decreasing Pd content of these samples, but may further result from the dilution of Pd surfaces with Pt, which would decrease the fraction of vicinal Pd atoms required for bridged bonding. This surface dilution requires metal alloying and cannot take effect in samples consisting of mixtures of monometallic metal clusters; consequently, the ratio of bridged to atop absorption in such mixtures is expected to decline monotonically with Pd content, reaching a value of zero only when there is no Pd remaining in the sample. The ratio of bridged to atop absorption bands for alloy clusters, by contrast, is expected to reach a value of zero once the Pd surfaces have been sufficiently diluted with Pt to preclude vicinal CO binding to Pd, at which point the remaining surface Pd atoms will exclusively bind CO in an atop configuration. The trend in FIG. 9 shows that that the ratio of bridged to atop absorption band intensities reaches a value of zero between 20-50 mol % Pd, suggesting the absence of monometallic Pd clusters and the complete isolation of surface Pd atoms by surrounding Pt domains. These data are therefore consistent with metal alloying in the Pd n Pt 100-n CaLTA samples.
Assessment of Metal Cluster Size and Composition with EXAFS Analysis
[0089] Fourier transforms of the k 3 -weighted EXAFS and their corresponding fits for bimetallic samples and reference foils measured at the Au-L 3 , Pd—K, and Pt-L 3 edges are shown in FIGS. 10, 11, and 12 , respectively. X-ray absorption spectra presented in FIGS. 10-12 were collected at ambient temperature under 100 kPa Ar following H 2 treatment (573 K, 10 kPa H 2 , 90 kPa He).
[0090] Metal coordination numbers (N), interatomic distances (D), and Debye-Waller factors (σ 2 ) obtained from these single scattering fits are shown in Table 2 below. Values in parentheses indicate the error in the final digit.
[0000]
TABLE 2
Sample
Edge
Scatterer
N (a)
D (b) , Å
σ 2(c) , Å 2
Au 50 Pd 50 NaLTA
Au-L 3
Au
6
(1) (d)
2.73 (2)
0.011 (4)
Pd
3.2
(8)
2.73 (1)
0.008 (2)
Pd—K
Au
5
(1)
2.73 (1)
0.008 (2)
Pd
3.1
(7)
2.69 (1)
0.007 (1)
Au 65 Pt 35 NaLTA
Pd—K
Pd
4.4
(4)
2.74 (1)
0.008 (1)
Pt
4.0
(3)
2.73 (1)
0.008 (1)
Pt-L 3
Pd
4
(1)
2.73 (1)
0.008 (1)
Pt
5
(1)
2.72 (1)
0.008 (1)
[0091] FIG. 10 shows the Fourier transform amplitudes and corresponding fits of the EXAFS oscillations at the Au-L 3 edge for Au 50 Pd 50 NaLTA and the Au foil. Fits of the Au-L 3 EXAFS for Au 50 Pd 50 NaLTA confirm two unique coordination shells around Au: one Au shell with a coordination number of 6±1 and interatomic distance 2.73±0.02 Å, and one Pd shell with coordination number 3.2±0.8 and interatomic distance 2.73±0.01 Å (Table 2). These individual coordination shells thus lead to a total Au coordination number of 9±1 after applying the propagation of uncertainty and rounding for significant digits. This total coordination number is significantly lower than that of bulk Au or AuPd alloys (12), indicating the prevalence of coordinatively unsaturated metal clusters. The interatomic distance (2.73 Å) derived from the fit is also smaller than that of a bulk Au 50 Pd 50 alloy (˜2.81 Å), consistent with the tendency for interatomic distances to contract in highly dispersed clusters. The total coordination number derived from the fit corresponds to metal clusters 1.3-2.1 nm in diameter assuming that they adopt FCC cuboctahedral structures; this diameter is consistent with that measured by TEM (1.6 nm) (Table 1). These data are consistent with the presence of alloyed phases and highly dispersed clusters, but must be considered concurrently with equivalent measurements at the Pd—K edge to provide a holistic interpretation of the metal coordination.
[0092] Fourier transform amplitudes and fits of the EXAFS oscillations at the Pd—K edge for Au 50 Pd 50 NaLTA and Pd foil are shown in FIG. 11 . Structural parameters derived from these fits (Table 2) showed two coordination shells around Pd absorbers: a Pd shell with coordination number 3.1±0.7 and interatomic distance 2.69±0.01 Å, and an Au shell with coordination number 5±1 and interatomic distance 2.73±0.01 Å. These individual coordination shells give a total Pd coordination number of 8±1. The addition of light scatterers (O or S) did not lead to improvements in the fit, consistent with the exclusive presence of metallic phases. The total coordination number and Au—Pd coordination number derived from these fits at the Pd—K edge are identical to or within error of equivalent parameters originating from the Au-L 3 EXAFS. The close agreement in the total Pd and Au coordination numbers suggests that Pd and Au atoms have similar first surroundings and occupy clusters of the same size, consistent with intimate metal mixing and the substantive absence of segregated metal phases. Randomly mixed alloy clusters with the experimentally measured Pd/Au ratio (Pd/Au=1; Table 1) and the fitted total coordination number (9) would be expected to give Au—Au, Pd—Pd, and Au—Pd coordination numbers of ˜4.5 each. The mean Au—Pd coordination number (4±1) falls within error of this value, suggesting uniform intracluster distributions of metal atoms. Therefore, it is concluded that the Au surface enrichment brought forth by the H 2 pretreatment of these samples at 353 K was lost during the ˜10 h induction period in which the samples were stored at room temperature under inert gas prior to XAS measurements. Such restructuring to well-mixed alloy clusters did not occur prior to CO IR studies, likely because of the rapid cooling (−0.17 K s −1 ) of the samples after treatment at 573 K to sub-ambient temperature (278 K). Au—Au and Pd—Pd coordination numbers (6±1 and 3.2±0.8, respectively) deviated slightly from the coordination number expected from random mixing (˜4.5), though these values are within error of the average Au—Pd coordination number (4±1). The precision of these parameters therefore precludes speculation as to the precise intracluster distribution of metal species or their preferred occupancy on specific surface sites (e.g., corners, terraces). These parameters derived from the EXAFS, however, are consistent at each metal edge and confirm the small size, intimate metal mixing, and absence of monometallic phases in Au 50 Pd 50 NaLTA.
[0093] FIG. 11 shows the Fourier transform amplitudes and fits of the EXAFS at the Pd—K edge of Pd 65 Pt 35 NaLTA; structural parameters derived from these fits are shown in Table 2. The Pd absorbers showed Pd and Pt coordination shells with coordination numbers 4.4±0.4 and 4.0±0.3 and interatomic distances of 2.74±0.01 Å and 2.73±0.01 Å, respectively. These coordination shells lead to a total Pd atom coordination of 8.4±0.5, corresponding to 1.1-1.7 nm clusters assuming FCC cuboctahedral particles. This size is in good agreement with that determined from TEM (1.2 nm, Table 2). The inclusion of O and S scatterers did not improve the fit, suggesting the presence of only metallic phases. FIG. 12 shows the corresponding Fourier transform amplitudes and fits of the EXAFS at the Pt-L 3 edge of Pd 65 Pt 35 NaLTA. Structural parameters extracted from the fit (Table 2) gave two coordination shells around Pt: a Pd shell with coordination number 4±1 and interatomic distance 2.73±0.01 Å, and a Pt shell with coordination number 5±1 and interatomic distance 2.72±0.01 Å, leading to a total coordination number of 9±1. The total coordination number extracted from these fits of the Pt-L 3 EXAFS is within error of that derived from the Pd—K edge of Pd 65 P 35 NaLTA (8.4±0.5). This close agreement in the total coordination numbers indicates that the Pd and Pt atoms occupy clusters of the same size and have similar coordination environments, consistent with the predominant presence of these metals in alloy clusters and the absence of monometallic phases. Randomly mixed PdPt alloy clusters with the experimentally measured Pd/Pt ratio (1.56, Table 1) and the average total coordination number (9±1) are predicted to give Pd—Pd, Pd—Pt, Pt—Pd, and Pt—Pt coordination numbers of 5, 4, 5, and 4, respectively. The Pd—Pt and Pt—Pd coordination numbers derived from the EXAFS fits are within error of these predicted values, suggesting relatively uniform intracluster distributions of metal atoms. The fitted Pd—Pd and Pt—Pt coordination numbers (4.4±0.4 and 5±0.4, respectively) are also similar to the values expected from random intracluster distributions of metal atoms. Monte Carlo simulations of bimetallic PdPt clusters indicate that Pd atoms should preferentially occupy low coordination surface sites (e.g., corners, edges) at the conditions of these XAS measurements, though it is unclear from the extracted coordination numbers whether the zeolite-encapsulated clusters also adopt this configuration. The coordination numbers derived from the EXAFS of Pd 65 Pt 35 NaLTA, however, show internal consistency at the Pd—K and Pt-L 3 edges and confirm the predominant presence of alloy clusters that are highly dispersed and uniform in composition.
Catalytic Assessment of Reactivity and Encapsulation
[0094] Metal cluster confinement within zeolites precludes access by certain reactants or poisons to intracrystalline active clusters. Such restricted access also serves to retain large products until they convert to smaller species that can egress by diffusion, while the small intracrystalline voids can stabilize specific transition states. In all cases, these effects are dictated by the size of the voids and their connecting apertures in a given microporous framework. Here, such zeolite shape-selective properties are exploited by measuring oxidative dehydrogenation (ODH) turnover rates of a small molecule (ethanol, 0.40 nm kinetic diameter) on samples exposed to a large organosulfur molecule that poisons metal surfaces (dibenzothiophene, DBT; 0.9 nm kinetic diameter) to estimate the extent that bimetallic clusters reside within zeolite crystals. Organosulfur compounds such as DBT irreversibly adsorb onto Au, Pd, and Pt surfaces, forming unreactive species that block active sites. Consequently, ethanol ODH turnover rates on metal-SiO 2 samples and extracrystalline bimetallic clusters in metal-NaLTA samples would be suppressed by DBT, while clusters protected by NaLTA pore apertures (0.42 nm) would retain their ODH rates because they cannot be reached by DBT. The rate differences upon contact with DBT then provide a measure of the selectivity of metal encapsulation within intracrystalline domains.
[0095] Alkanol ODH reactions form alkanals as primary products. These alkanals can undergo subsequent reactions with alkanols to form hemiacetals or alkoxyalkanols and then dialkoxyalkanes and carboxylic acids through secondary dehydrogenation or condensations reactions. These secondary reactions do not affect measured turnover rates, because each product molecule formed involves a single ODH event, in which an alkanal forms via kinetically-relevant β-H abstraction from an adsorbed alkoxide by chemisorbed oxygen. The low conversions prevalent in this study (<5%) minimize secondary reactions and lead to high acetaldehyde selectivities (>95%, C-basis).
[0096] Ethanol oxidative dehydrogenation (ODH) turnover rates were measured on catalyst powders first diluted 10-fold by mass with fumed SiO 2 (CAB-O-SIL® HS-5, 310 m 2 g −1 ) and then pressed into pellets and sieved to retain 180-250 μm aggregates. These diluted samples were then mixed in a 1:1 mass ratio with 180-250 μm acid-washed quartz granules to prevent any temperature gradients caused by exothermic ODH reactions. Catalysts were placed on a porous quartz frit within a quartz tube (10 mm O.D.). Samples were heated in 20% O 2 /He (1.67 cm 3 g −1 s −1 ) from ambient temperature to 393 K (at 0.033 K s −1 ) and held at that temperature for rate measurements. Liquid ethanol and deionized water were vaporized into flowing O 2 /He streams at 393 K using liquid syringe pumps (Cole Parmer, 60061 Series). He and O 2 flow rates were adjusted with mass flow controllers (Porter Instrument) to achieve the desired pressures (4 kPa alkanol, 9 kPa O 2 , 87.5 kPa He, and 0.5 kPa H 2 O). Water forms as an ODH product and can have a co-catalytic effect. Thus, water was added to maintain a constant concentration of all species throughout the catalyst bed, thereby ensuring differential conditions. Alkanol conversions were kept below 5% and transfer lines were heated to 393 K to avoid condensation.
[0097] Turnover rates are defined as the molar ethanol conversion rates per surface metal atom estimated from the dispersion values defined in Equation 3. Product formation was not detectable on NaLTA, fumed silica, and empty reactors. Turnover rates were extrapolated to the start of each experiment. Effluent concentrations were measured by gas chromatography (Shimadzu GC-2014) using a methyl-silicone capillary column (HP-1; 50 m×0.32 mm, 1.05 μm film thickness) and a flame ionization detector.
[0098] Metal-NaLTA samples were exposed ex-situ to dibenzothiophene (DBT), an organosulfur poison that irreversibly titrates noble metal surfaces, before their use in ethanol ODH reactions. Ex-situ treatments exposed metal-NaLTA and metal-SiO 2 samples to DBT dissolved in liquid ethanol (300 cm 3 g −1 ; DBT/metal molar ratio of 6) at ambient temperature for 4 h with magnetic agitation (6.7 Hz). The samples were then filtered and treated in ambient air at 343 K for 12 h, and used in ethanol ODH reactions at 393 K. Control samples were also prepared through an identical procedure without DBT and used for ethanol ODH.
[0099] Ethanol (0.40 nm kinetic diameter), but not DBT (0.9 nm), can diffuse through the apertures of NaLTA (0.42 nm). Thus, the extent of deactivation caused by exposure to DBT provides an assessment of the fraction of metal surfaces that are confined within zeolite crystals and protected from any large molecules present in the extracrystalline regions. A comparison of rates before and after exposure to DBT on metal-NaLTA and metal-SiO 2 samples then indicates the fraction of the active surfaces present at extracrystalline locations and thus the selectivity of the encapsulation.
[0100] Samples were exposed to DBT as described herein above before ODH rate measurements at 393 K. ODH rates were also measured on samples that were not contacted with DBT (denoted as “control samples”), but treated otherwise identically. ODH turnover rates measured on these controls (r ODH ) and on samples exposed to DBT (r ODH, DBT) are used to define a parameter Λ DBT according to Equation (4):
[0000]
Λ
DBT
,
i
=
r
ODH
,
DBT
r
ODH
(
4
)
[0000] where i identifies the specific sample (e.g., Au 50 Pd 50 NaLTA, Pt/SiO 2 ). The value of Λ DBT,i reflects the fraction of the active surfaces that remain active for ODH after DBT exposure. A Λ DBT,i value of unity would reflect fully protected clusters, while a value of zero is expected if every active surface atom is accessible to and fully deactivated by DBT. Metal clusters that are encapsulated inside zeolites should be inaccessible to DBT and thus protected from deactivation, while metal clusters outside the zeolite crystals should be accessible to and deactivated by DBT. Exposure to DBT thus selectively suppresses the contribution to the ODH rate that originates from extrazeolite clusters. As a result, the value of Λ DBT,i is proportional to the fraction of encapsulated clusters in metal-zeolite samples. Values of r ODH and Λ DBT,i for Au, Pd, and Pt clusters supported on mesoporous SiO 2 and a representative group of bimetallic samples are shown in Table 3.
[0000]
TABLE 3
Sample
r ODH (10 −3 s −1 mol surf-metal −1 ) a
Λ DBT b
Au 50 Pd 50 NaLTA
110
0.97
Au 50 Pt 50 NaLTA
210
0.95
Pd 65 Pt 35 NaLTA
280
0.98
Au/SiO 2
12
0.11
Pd/SiO 2
320
0.03
Pt/SiO 2
490
0.04
(a) Ethanol ODH turnover rates of samples agitated in EtOH (300 cm 3 g −1 ) at ambient temperature for 4 h, treated in ambient air at 343 K for 12 h, then used in reaction (393 K under 9 kPa O 2 , 4 kPa EtOH, and 0.5 kPa H 2 O).
(b) r ODH, DBT /r ODH (Equation 4), where r ODH, DBT is the ethanol ODH rate of analogously treated samples but with DBT dissolved in the EtOH at a 6:1 DBT:metal molar ratio. Reaction turnover rates are defined as the number of moles of reactant converted per time normalized by the number of exposed surface metal atoms estimated by TEM (Equation 3).
[0101] Ethanol ODH turnover rates were much more weakly suppressed by contact with DBT on metal-NaLTA (Λ DBT,i =0.95-0.98) than on metal-SiO 2 (Λ DBT,i =0.03-0.11) samples (Table 3), indicating that (a) DBT effectively titrates unprotected noble metal surfaces; and (b) most of the metal clusters reside within LTA crystals in metal-NaLTA samples. The small residual ODH activity on SiO 2 -supported samples, even after contact with excess DBT (6:1 DBT:metal molar ratio), may reflect steric effects that hinder access to remaining open sites as DBT-derived species reach near-saturation coverages. The remarkable resistance to DBT poisoning in metal-NaLTA samples, evident in their Λ DBT,i values near unity (0.95-0.98) (Table 3), provides compelling evidence for the near complete encapsulation of these bimetallic clusters, as also found for monometallic clusters encapsulated within LTA and other zeolites using similar hydrothermal synthesis protocols.
[0102] It is concluded that the hydrothermal encapsulation method described herein can be more generally applied to prepare bimetallic clusters which are small and uniform in size, highly stable against thermal sintering, homogeneously distributed in composition, and selectively encapsulated within zeolite crystals.
[0103] As used herein, the term “comprising” means including elements or steps that are identified following that term, but any such elements or steps are not exhaustive, and an embodiment can include other elements or steps.
[0104] Unless otherwise specified, the recitation of a genus of elements, materials or other components, from which an individual component or mixture of components can be selected, is intended to include all possible sub-generic combinations of the listed components and mixtures thereof.
[0105] All ranges disclosed herein are inclusive of the endpoints and are independently combinable. Whenever a numerical range with a lower limit and an upper limit are disclosed, any number falling within the range is also specifically disclosed.
[0106] All documents cited in this application are herein incorporated by reference in their entirety to the extent such disclosure is not inconsistent with this text. | Zeolites having highly dispersed bimetallic clusters, uniformly distributed in size and composition, encapsulated therein are disclosed. Metal encapsulation and alloying is conferred by introducing ligated metal cation precursors into zeolite synthesis gels, which are subsequently crystallized hydrothermally to form zeolites with metal cations occluded in the pores. The ligated cations are anchored to the zeolite framework via siloxane bridges which enforces their uniform dispersion throughout the zeolite crystals. Treatment of the crystallized zeolites in O 2 and then H 2 forms bimetallic clusters, which remain narrowly distributed in size and composition. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
The present invention claims the benefit of Provisional Patent application Ser. No. 60/424,890 filed Nov. 8, 2002, the full disclosures are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is a pushup trainer that will assist the user by increasing or decreasing the force required by increasing or decreasing the weight of the user with the aid of a mechanical means such as a spring, spring bar, elastic bands, hydrodynamics, etc. while performing pushups.
2. Description of the Related Art
The benefits of performing pushups for increased upper body development are well known. Pushups are one of the best exercises for strengthening the triceps, pectorals, and deltoids. Unlike weight training, pushups can be performed without the need for a spotter, and place less stress on the joints.
Several other inventors have proposed various devices for increasing the benefits of performing pushups. However, no other inventor within the knowledge of the present inventor has proposed a pushup trainer having the advantages of the present invention. Specifically, no other pushup trainer provides for an aid of the user to decrease (or increase) the force required to do a push-up. For the majority of individuals, push-ups can be too difficult to do with any significant amount or without doing them from the knees. Hence individuals refrain from doing push ups because they loose enthusiasm. The present invention provides for a force-assist device that allows the user to decrease (or increase for those over zealous athletes) the force required to do push-ups. With this aid, the user can then do more push-ups and remain more enthused for this important strength training exercise.
U.S. Pat. No. 4,854,573 to Johannson discloses an exercise apparatus which has three hand grips having different elevations which are individually selectable to vary the degree of difficulty of push-up exercises. The Johannson device rests on a floor and is rotatable to a plurality of positions. While this device allows for different levels of difficulty, the range of difficulties that may be provided by this device is rather limited unless the device is built to an unduly and inconveniently large size.
U.S. Pat. No. 5,181,897 to Agan provides an exercise apparatus which relies on a non-planar surface other than a floor to enable a user to perform inclined push-up exercises. The Agan device includes angled brackets which are configured to conform to an edge of an object. However, the degree of difficulty which may be selected using this device is dependent upon whatever appropriate surfaces are accessible to a user. In certain circumstances, therefore, the range of difficulty levels which may be selected may be limited. Further, the Agan device is configured to receive an edge of an object in such a manner that the device may rock during normal exercise. Rocking during exercise tends to make the exercise more difficult and less enjoyable, while increasing the risk that the exercise device will become dislodged from the object upon which it is placed, thereby resulting in an injury to the user.
One example of a pushup trainer is U.S. Pat. No. 3,115,338, issued to Katherine and Peter Acs on Dec. 24, 1963. This patent describes a pair of handles having a flat base. The base rests on the floor, while a person performing pushups grips the handles. The handles may have a base with a suction cup, so that the suction cup can attach to a wall, allowing the user to grasp the grip to maintain his balance. A third embodiment has a hook-shaped bolt, allowing the handles to hang from an overhead support for performing pull-ups.
U.S. Pat. No. 4,351,525, issued to William L. Rozenblad on Sep. 28, 1982, describes a pair of wood platforms, each having a non-skid surface on the bottom, and a U-shaped handle on top. The handles may be used in pairs for performing pushups, or only a single handle may be used to provide for a more difficult pushup.
U.S. Pat. No. 4,610,448, issued to David L. Hill on Sep. 9, 1986, describes a pushup training device having both handgrips pivotally attached to the same base. The U-shaped bracket supporting the handgrips can rotate around a vertical axis, and the handgrips can rotate around a longitudinal horizontal axis.
U.S. Pat. No. 5,205,802, issued to William J. Swisher on Apr. 27, 1993, describes a pushup training device having a single elongated base for a pair of handgrips. The base includes holes positioned at various differences from its vertical center, allowing the handgrips to be positioned at a desired distance from the center. The handgrips can rotate around a vertical axis as the user performs pushups.
U.S. Pat. No. 5,226,868, issued to Calvin W. Montgomery on Jul. 13, 1993, describes a pushup training device having a board and two C-shaped handles. The board has holes in various positions for attaching the handles. Only one end of the handles attaches to the board, allowing the handles to rotate around a vertical axis at the attachment point.
U.S. Pat. No. 5,607,380, issued to John E. Duty on Mar. 4, 1997, describes a pushup training device having a pair of bases, with each base supporting a gripping bar. The gripping bar may be positioned at various desired angles. An elastic band extends from one handgrip to the other, passing over the back of the neck, to provide a workout for the neck muscles as the user pushes him up.
U.K. Pat. No. 2,270,636, published on Mar. 23, 1994, describes a pushup-training device having a board and a pair of U-shaped handles. The board has several sets of holes, allowing the user to position each of the handles in a pair of holes. The user can thereby set the handles a desired distance apart.
German Pat. No. 4,229,970, published on Mar. 10, 1994, describes an exercise device.
Additionally, several devices have been used to facilitate the performance of push-up exercises. For instance, U.S. Pat. No. 4,351,525 to Rozenblad, U.S. Pat. No. 4,358,106 to Shadford, and U.S. Pat. No. 4,621,806 to Wheeler, disclose various devices for supporting one or more handgrips on a floor or other flat planar surface.
The above devices are somewhat limited in that they place the hand grips a fixed distance from the floor during exercise. Many people, however, are not strong enough to do regular push-ups (i.e., where the hands and the feet are placed roughly along the same plane, the floor). The difficulty of performing a push-up exercise decreases if the weight bearing on the arms is decreased. It is often beneficial to decrease the level of difficulty of push-up exercises, since many people lack the strength to do standard push-up exercises. This may occur for example because of a previous injury or age. Alternatively, it may be beneficial to decrease the level of difficulty so that the number of repetitions may-be increased, thereby providing a better overall workout.
None of the above patents describes a pushup trainer allowing the user to selectively choose a preferred force that is used for the push-up. Thus a push-up trainer solving the aforementioned problems (a need exists for a device for facilitating the performance of push-up exercises over a wide range of difficulty levels) is desired.
SUMMARY OF THE INVENTION
The present invention is a pushup trainer having a base and a top with a force controller in between. This controller allows the user to aid them by increasing or decreasing the force (usually decreasing).
One embodiment of the present invention is that the top is placed against the chest area and then a spring type mechanism is placed between it and the bottom/base. As the user goes down to begin their first push up, the spring like mechanism pushes up on their chest, removing some force on their arms. As the user begins to push up and complete the push up, the spring like mechanism pushes up thus decreasing the force required.
Another embodiment would be a ring that is made of a spring material that is placed between the chest area and the floor to assist with push-ups. As the user allows him/herself to go toward the floor, the ring goes from a circular shape to oblong to eventually a flat, squashed loop. Because it is made of a spring material (metal or plastic), the squashed loop has a pushing force that will aid in pushing the user back up to this or her original position with the arms extended. This force on the ring is easily changed with the addition/deletion of springs, elastomeric bands in the transverse/horizontal position, etc.
A unique feature of the present device is that it decreases resistance and assists the user in completing the exercise, and does so very simply. Most other exercise devices provide resistance by the means of weights, belts, elastic straps, or hydraulics. In other words, they tend to make the exercise more difficult, rather than providing a means to make the exercise easier.
To facilitate comfort, the device may be provided with a soft compressible covering. It may be contoured to fit the general shape of the human chest. It may be bolstered so that much of the weight of the user is supported by the center of the chest and the upper chest, i.e., the sternum and sternal area and the large upper pectoral muscles provide much of the support to the user. This would diminish the pressure on the breast region, and facilitate comfort for female users.
To facilitate additional exercise, the device may be used as a pull-up device to exercise, strengthen, and tone muscle groups not addressed by the push up routine. The user would stand on the device. Additional bands or spring tension, in the preferred embodiment, may be needed to support the full weight of the user.
To provide a bar or hand hold for the pull-ups, a handle is connected to a U-shaped bracket that fits over the top of a door. The bracket is positioned near the hinged side of the door so that the hinges support most of the weight of the exercise. The user simply positions the assist device of the present invention adjacent to the closed door so that the user is facing the door. The handle of the pull-up bar is parallel with the closed door. The user then stands on the assist device and does pull-ups. The pull-up device may be provided with handles that project perpendicular to the door for exercising additional muscle groups, i.e., the biceps.
Since the doorways in most homes will not provide enough vertical height to allow a full extension pull-up, i.e., one beginning with the arms fully extended, if most users stand on the assist device of the current invention fully erect, the user may elect simply to flex the knees to allow the arms to be fully extended at the onset of the exercise.
Alternatively, a separate frame may be provided for the pull up routine.
Additionally, the user may elect to sit on the device to perform other exercises. By sitting on the device and placing each hand on a chair seat, the assist device will facilitate exercises that target the triceps and shoulder girdle muscles.
Devices described herein are generally the size to fit beneath or above the athlete's/user's chest. There may be different sizes and shapes for difference sizes and shapes of users.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 , 2 & 3 are schematic illustrations of embodiments of the device constructed in accordance with the principles of the present invention.
FIG. 1 is an isometric view of the preferred embodiment of the instant invention, the ‘Push-Up Exercise Apparatus’ or ‘Pull-Up Apparatus’ or ‘Dip Apparatus’.
FIG. 2 is an isometric illustration of the exercise apparatus of the instant invention with the user demonstrating the apparatus for use as a ‘Push-Up Exercise’ apparatus.
FIG. 3 is a schematic illustration of an embodiment of the present invention using a coil spring type of spring element.
These illustrations show only some potential configurations of the present invention. Other parametric changes of the present invention can occur such as location of the force element on the device as well as the actual type of mechanism(s) or element used.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is an isometric drawing of the instant invention. This particular apparatus 1 is most suited to doing exercises such as push-ups, pull-ups or dips. The device 1 consists of a loop spring 2 , a base 3 and a pad 4 . The loop spring has been iteratively designed to add resistance (and subsequently help) to the user while doing exercise. The loop spring 2 is designed with a spring steel piece of flat stock spring steel that is approximately 0.036 inches thick and approximately 1.00 inches wide and approximately 132 inches long. The spring steel band or piece of flat stock is coiled into an approximate diameter 5 of 14 inches. This allows the spring steel band to be coiled three times around into the 14 inch diameter 5 circle. The steel ban is then fastened, usually with a rivet (not shown) to hold the looped spring steel in the circular shape in a 14-inch diameter 5 . A hole (approximately 0.220 inches in diameter (not shown)) is then drilled through the three loops and centered for fastening the bottom 6 of the loop spring 2 to the base 3 . This is most easily accomplished by screwing in a bolt with knob 7 into the base 3 and through the hole in the loop spring 2 . The base 3 has a female thread centered in the base and directly below the screw 7 . Additionally the base 3 has a crescent shaped groove 9 in the base 2 for holding the loop spring 2 in position in the base. Even further, a crescent shaped block 8 with a hole drilled through it approximately 0.220 inches in diameter fits on top of the loop spring 2 . The screw 7 with knob is then placed through the loop spring 2 then the crescent block 8 and finally into the base 3 and tightened. The crescent block 8 provides additional support to the exercise apparatus once assembled. The base is usually made of a polymer plastic such as, but not limited to ABS plastic, which is molded into the preferred configuration show in FIG. 1 . The base 3 has an approximate size of 14 inches by 14 inches as shown in the illustration. This base size allows the un-assembled apparatus to be easily packaged and stored with the base 3 fitting inside the loop spring 2 . The pad 4 can be fabricated of several softer polymers such as polyurethane foam or other polymer foams. The pad provides a softer edge on the topside of the exercise apparatus and adds comfort to the user. In the case of push-ups, against the chest, in the case of dips, against the buttocks and in the case of pull-ups, against the feet. This pad can have a variety of configurations such as wet suit material or even cloth. It may be stitched or bonded to the loop spring 2 with a variety of glues commercially available.
Also illustrated in FIG. 1 is an elastic band 10 that is mounted near the mid diameter of the apparatus. This single band 10 adds spring force to the loop spring 2 so that if the user needs additional resistance while doing an exercise, the elastic band 10 can provide such additional assistance. This elastic band 10 can be of any of a variety of elastomeric materials such as natural rubber (e.g. rubber bands), butyl rubber, silicone rubber, polyurethane, etc. Additionally, although not shown is the fact that additional bands can be added to increase the resistive force. Prototypes were fabricated using as many as five rubber bands that significantly increased the resistive force.
Turning now to FIG. 2 , another isometric drawing of the instant invention is illustrated. In this particular embodiment, the user 11 is doing a push-up using the apparatus 1 . The apparatus 1 is placed under the user's chest while doing the push-up. As the user 11 begins to do a push-up, the apparatus 1 is compressed as the user 11 allows his or her weight to be applied to the apparatus as the user is going downward. Once the user 11 reaches the floor or near the floor in his or her push-up, and he or she begins to push back up away from the direction of the floor, the apparatus applies a force to the user's body and aids with accomplishing the push-up. Not illustrated is the user 11 doing a dip or pull-up, but the same practice of the apparatus 1 applies to aiding with the force to help the user 11 do the exercise. In this illustration, the user 11 has the spring loop 2 oriented perpendicular to the bodyline, but the device has also been used parallel to the body line (not illustrated) between the breasts. Also not illustrated are the elastic bands 10 mentioned above. If additional force/assistance would be required by the user, these bands 10 could be added to FIG. 2 as is shown in FIG. 1 .
FIG. 3 schematically illustrates an apparatus 1 using a coil spring 12 type of spring element between a base 3 and a pad 4 . Also illustrated are spacers 14 which can be added between the coils 16 of spring 12 to permit the compression force to be adjusted.
Although the foregoing invention has been described in some detail by way of illustration and example, for purposes of clarity of understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims. | Exercise devices that have a novel mechanical that allow the force required to do push-ups, pull-ups or dips to be varied to aid with athletic training. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/596311, filed Sep. 14, 2005 and entitled “Method and Apparatus For Forming A melt Spun Nonwoven Web”. The disclosure of this provisional patent application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention pertains to methods and apparatus for spinning thermoplastic polymer filaments and, more particularly, to improvements therein using non-eductive drawing.
BACKGROUND
[0003] In general, spun bond nonwoven production machines can be classified as eductive “open” spinning systems and non-eductive “closed” spinning systems. Conventional broad loom eductive systems can generally trace their roots to the subject matter disclosed in U.S. Pat. No. 3,802,817 (Matsuki et al.) which describes a system that extrudes a curtain of filaments, extending the full width of the machine into, atmosphere (and/or impinged with cooled air). The curtain is then subjected to the action of a pair of air jet streams in a sucker, or filament drawing unit, the jet velocity of said jet streams being selected in the turbulent range. The jets act to entrain air from atmosphere along with the fibers which are then projected from the drawing unit onto a gas pervious conveyor belt collector to form a web. The quenching air system is separate from the filament drawing unit system. The fibers being spun are typically exposed to atmosphere at least once and usually twice: once just after being extruded and then again between the drawing device and the collector belt. This basic design has evolved into modern systems, for example, see U.S. Pat. Nos. 6,183,684 (Lu), 6,783,722 (Taylor) and 6,692,601 (Najour), all of which describe improved non-eductive “open” spinning nonwoven production systems.
[0004] Conventional broad loom non-eductive spinning systems can generally trace their roots to the disclosure in U.S. Pat. No. 4,405,297 (Appel et al.) which describes a system for forming spun bond nonwoven webs by spinning a plurality of filaments into a quench chamber where they are contacted with a quenching fluid, then utilizing the quench fluid to draw the filaments through a nozzle spanning the full machine width, and collecting the filaments as a web on a gas pervious conveyor belt collector. The fibers being spun are usually enclosed or shielded from atmosphere until they are formed into a web on a conveyor. This basic design has evolved into modern systems, for example U.S. Pat. No. 5,032,329 (Reifenhauser).
[0005] There are also hybrids of the two arts in which closed systems are aided by high pressure eductive jets to increase filament speeds, as shown in U.S. Pat. Nos. 5,503,784 (Balk) and 5,814,349 (Geus et al.).
[0006] The systems and methods discussed above have various disadvantages and limitations. Specifically, eductive (open) type systems inherently create high levels of turbulence and vorticity that are hard to control from day to day, and which tend to entangle and group the filaments into bundles, thereby limiting the uniformity of the final products. Furthermore, prior art eductive systems involve small fixed eductor throat openings which suffer drawbacks such as frequent plugging and cannot be opened to clear drips and plugs. In addition to plugging the throat of an eductor, small deposits of polymer drippings, monomer build up and scratches from constant cleaning all affect the patterns of turbulence on a day to day, and even on an hour to hour basis. The high speed jet nozzles themselves tend to become clogged by debris that enter from the process air supply and monomer, thereby drastically upsetting flow in the highest speed areas and creating vortices in the drawing unit. These systems also require two sources of air and two sets of associated equipment; one, a low pressure cooled air source that is used to quench the molten filaments by removing heat energy; and the other, a high pressure air source required to produce high velocity air to draw the filaments. The high velocity air generates high noise levels as it draws the filaments. While higher spin speeds required for spinning polyester and Nylon can be achieved with specialized eductive systems, the problems of turbulence and system hygiene are amplified by higher air jet pressures and velocities. Thus, forming a uniform web is very difficult with these systems because the fiber/air stream is moving very fast relative to the vertically stationary (but horizontally moving) collector belt. The amount of energy in the stream is so high at the belt that the fibers tend to bounce off the belt. The fibers can also be blown off the belt by the excess of air that cannot be passed through the below-the-belt vacuum system that generally is not able to evacuate all of the process air.
[0007] Conventional non-eductive (closed) systems typically permit somewhat more web formation control than do eductive systems; however, the non-eductive systems have fiber spin speed limitations. The long nozzle or throat sections where the fibers are attenuated are subjected to large structural loads from pressurized quench fluid. Even at pressures slightly above atmosphere, these walls must sustain loads of thousands of kilograms. These pressure loads cause deflection of the walls which, in turn, have to be pushed back into place uniformly across the machine width. The geometry of the nozzle controls quench fluid speed, which in turn controls fiber speed and formation of the web. Structural support of the wall geometry severely limits the pressure of the quench fluid, ergo the permissible velocity of the fluid in the nozzle and fiber speed. Also, the large surface areas of the nozzle have the same system hygiene problems as are present in eductive systems, but there is more surface area for deposits to collect, and it is not easy to get inside these nozzles to effect cleaning.
[0008] Hybrid systems were conceived primarily to increase the spin speeds of non-eductive systems. Hybrids typically incorporate eductive air jets somewhere along the nozzle area, which act to boost nozzle velocity without increasing quench fluid pressure. These systems have worked for some but not all higher speed spinning applications, and tend to be very complicated and capital intensive, and require substantial operation and maintenance attention.
SUMMARY OF THE INVENTION
[0009] In contrast to the prior art systems described above, the system and method of the present invention involve an initial quench chamber and the use of a continuous two-dimensional slot across the entire machine width which produces a linear plane of filaments in the slot impingement point section. The linear plane of filaments has substantially constant filament distribution across the machine width, and provides for good control of cross-machine uniformity. As used throughout this description, “machine widths” refers to a dimension corresponding to the width generally of the spinning plate and is perpendicular to the collector belt travel. It is preferred that the width correspond to the desired end web width. The width of the machine is only limited by the ability to machine and maintain close geometric tolerance of the impingement slot dimensions. The process equipment is very simple compared to both eductive and non-eductive systems.
[0010] No air is educted into this system as the quench fluid, usually air, undergoes uniform acceleration into the impingement slot where the drawing force is developed. The same air is used for two purposes: first to quench the filaments and then to draw them as the air exits through the drawing impingement slot at high velocity. The drawing chamber is relatively small and there is substantially no nozzle length parallel to the fiber/air stream; therefore higher quench pressures can be obtained without leading to structural deflection problems that affect spinning area geometric tolerances which in turn would cause variations in spin velocities and turbulence. Higher pressures and the mixing effect of the exiting fiber/quench stream produce very high air and fiber velocities. The small amount of close tolerance machined surface area that is exposed to the fiber stream (i.e., only the tips of the air knives) collect far less dirt, polymer drippings and monomer build up than other systems. Cleaning is much simpler and only takes a few seconds while the machine is running by opening the slot for a few seconds and wiping clean the knife edges. An automatic wiper could be employed. This can be done several times a day, if needed, whereas most other conventional systems require hours and even days to clean educator and nozzle surfaces.
[0011] By selecting a suitable slot gap opening, the necessary drawing tension can be obtained. Filament cooling is controlled by regulating the temperature of the quench fluid and controlling the rate of flow of air past the filaments to exhaust ports near the top of the quench chamber, as is known in the prior art. The amount of quench air exiting the duct is important to the operation of the process, so this flow rate is preferably closely monitored and controlled. If there is too high an exhaust flow, the velocity of the air through the filament bundle will cause the filaments to waver and stick to each other, thereby causing filament breakage. The filaments will also be cooled too rapidly and large denier, brittle filaments will be produced. With too little exhaust, the filaments may not be totally quenched when they enter the drawing impingement slot, increasing the incidence of sticking to the slot's air knives.
[0012] To achieve the benefits of the present invention, it is desirable that the apparatus be constructed and the method carried out within certain ranges of parameters. For example, the quench air should be maintained at a temperature in the range of from about 40° F. to 200° F. The air flow rate should be maintained within the range of from 850 cubic meters per hour to 3,400 cubic meters per hour per meter of machine width, and the slot opening should have a length from about 0.5 mm to 10 mm. As indicated above, the exhaust flow rate is important in achieving the desired filament properties and, generally, will be within the range of from nearly 0 to about 400 cubic meters per hour per meter of machine width.
[0013] The length of the quench chamber for a particular application will depend, of course, upon the material being spun and the particular web properties desired. Accordingly, these parameters may vary widely, but, in general, will be at least 250 mm and, preferably within the range of from about 250 mm to 1500 mm for the length of the quench zone from the spinneret to the impingement slot. Similarly, the spinneret capillaries may be in many configurations but will, generally, be employed in the range of from about 500 to 8000 holes per meter of machine width in a uniform capillary array. As will be apparent from the foregoing description, the method and apparatus of the present invention are extremely flexible and can be varied to accommodate a wide variety of materials and operating conditions. That constitutes a particular advantage and feature of the present invention.
[0014] The above and still further features and advantages of the present invention will become apparent upon consideration of the following definitions, descriptions and descriptive figures of specific embodiments thereof wherein like reference numerals in the various figures are utilized to designate like components. While these descriptions entail specific details of the invention, it should be understood that variations may and do exist and would be apparent to those skilled in the art based on the descriptions herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic flow diagram of a preferred embodiment of the present invention shown operating in a “run” mode.
[0016] FIG. 2 is a schematic flow diagram of the preferred embodiment of FIG. 1 shown operating in a “run” mode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The following detailed explanations of FIGS. 1 and 2 of the preferred embodiments reveal the methods and apparatus of the present invention. The architecture depicted in the drawings is a conceptual diagram illustrating major functional units, and does not necessarily illustrate physical relationships.
[0018] The present invention harnesses the positive aspects of both eductive and non-eductive (and hybrid) systems into a more efficient and simpler design. More importantly, the invention solves many of the problems associated with conventional nonwoven spun bond systems including: spinning speed limitations, energy consumption, machine element cleanliness (i.e., hygiene), web uniformity, capital costs and process control. The invention also incorporates aspects of another, different type of nonwoven web forming technology, the meltblown process, as shown in U.S. Pat. No. 3,825,380 (Harding et al.) to help improve web formation control.
[0019] While the invention is described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
[0020] Referring to FIG. 1 , the first step in the method of the invention is to provide a thermoplastic polymer in fluid condition for spinning. The flexibility of the system and method of the present invention allows a wide variety of polymers to be processed. For example, any of the following may be employed: polyamides, polyesters, polyolefins, polyvinyl acetate, polyvinyl chloride, polyvinyl alcohol, and the like. It is, of course, contemplated to also utilize other spinable materials which may not be ordinarily considered polymers such as, for example, molten glass and carbon fiber pre-cursors. It is important that the material be capable of being made sufficiently fluid for spinning and otherwise have the properties necessary to undergo drawing in the filament drawing zone. Other examples will become apparent to those skilled in the polymer art.
[0021] The molten polymer or other raw material is fed from supply 2 to hopper 4 , then through screw extruder 6 , filter 8 , and polymer transfer pipe 10 to spin box 12 , which contains one or more metering pumps 14 . Filaments 16 are spun through spinneret 18 with appropriate openings arranged in one or more rows forming a curtain of filaments 16 directed into the quench chamber 20 . In the quench chamber 20 the filaments 16 are contacted with air or other cooling fluid 22 received through fluid inlet 24 and diffused through perforated apertured plates 26 . The quench fluid, usually air, is maintained cooler than the filaments, preferably near ambient temperature, but anywhere, for example, in the range of from about 40° F. to 200° F. The quenching fluid is supplied under pressure of less than 4 bar, preferably less than 2 bar, and a portion is preferably directed through the filament curtain 16 and removed as exhaust through ports 28 .
[0022] As described above, the proportion of the air supplied that is discharged as exhaust will depend on the polymer being used and the rapidity of quenching needed to give desired filament characteristics such as denier, tenacity and the like, and to exhaust by-products of extrusion i.e.: smoke and monomer.
[0023] As quenching is completed, the filament curtain is directed through a narrowing lower end 30 of the quenching chamber into the impingement point slot opening 32 where the quench air attains a velocity that can be anywhere in the approximate range of 3,000 to 21,000 meters per minute. The drawing slot extends across the full machine width and is preferably formed by two identical air knives 34 having an angle in the range from about 15° degrees to 80°, with a preferred angle of 45°, spanning the width of the machine. In the preferred embodiment the bottom surfaces of the knives 34 are co-planar and substantially horizontal; however, it is to be understood that these surfaces can be angled to converge toward one another for certain applications. The convergence, if provided, would typically be such as to provide a protruding or convex bottom surface for the chamber, although in some instances a recessed or concave bottom surface may be provided. The movable air knives can be retracted from one another under the chamber assembly using a manually actuable and lockable slide arrangement, or a hydraulically or otherwise actuable arrangement. FIGS. 1 and 2 depict knives forming a 90° entry angle between them. The blades may either slide laterally or instead pivot about a point near the upper corner of the blade, whereby the tip of each blade would swing down in an arc until the upper blade surfaces came into a parallel relationship for cleaning. To pass slubs, the tips would only need to move ½″ or so apart.
[0024] Referring to FIG. 2 , during start-up, the knives are fully retracted or spaced from one another so that the filaments can fall by gravity through the wide open slot. The low velocity of the incoming quench air is maintained through the wide open slot so that little aerodynamic drawing actually occurs. When polymer flow is fully established, the air knives are slowly moved toward one another to decrease the slot opening, increase the air velocity, and draw the filaments. If a major process upset occurs and the drawing slot becomes partially plugged or clogged with polymer during operation, one or both air knives can be momentarily drawn back until the polymer plug falls through the enlarged nozzle opening. The air knives 34 can then be moved back to their normal operating position.
[0025] The position of the air knives relative to each other determines the size of the drawing nozzle opening and thus the velocity of the air going through the nozzle for a given quench air flow rate, pressure and exhaust setting. The filament drawing force increases as the air velocity increases so that the filament denier can be easily changed by simply increasing or decreasing the size of the nozzle opening. Filament denier can also be increased several other ways i.e.: enlarging the slot gap; reducing the air flow rate through the slot by decreasing the pressure in the chamber; increasing the exhaust air flow rate; lowering the quench air temperature; decreasing the polymer temperature; increasing the polymer viscosity; or increasing the polymer throughput per capillary.
[0026] Thus, the filament deniers can be changed relatively easily and rapidly in several different ways which do not affect the distribution of filaments exiting the slot to atmosphere. In all cases, the slot desirably spans the entire width of the machine. Therefore, a distribution of filaments corresponding substantially identically to the distribution of the orifices in the spin plate across the machine width is maintained all the way to the outlet of the slot. When the fibers and quench fluid exit the impingement slot 32 , they are exiting to atmosphere. Exposing the filaments to the interior of a high speed air stream, similar in speed to an eductive fiber draw unit jet stream, produces very good energy transfer from quench fluid velocity to fiber speed, for several reasons:
The air jet formed at the impingement point is transferring energy only to fibers (like a non eductive system) and not wasting energy entraining air from atmosphere to create the low pressure suction at the top of an eductive drawing device. The fibers are exposed to the air jet formed inside the impingement point, which means that the fibers see the peak velocity of the stream. In eductive systems, the fibers enter the stream (in the fiber draw unit) after the jet achieves peak velocity, after it mixes with atmosphere and entrained air, so that that the resultant energy transfer, directly to the fibers, is lower. When a stream of fluid is directed through an air knife slot to atmosphere, it immediately loses its pressure as it expands to atmosphere. Energy of the quench fluid mass is transformed from pressure to velocity. The stream begins to “opens up” or widen from the original slot width as the pressurized compressible gas expands, which, in turn, begins to slow the stream velocity. If one adds fibers at this point, the mix of expanding fluid and independent flexible fibers creates a highly turbulent mixing zone just below the exit which tremendously aids the transferring of quench fluid energy (mass×velocity) to fiber velocity. This also acts to slow down the stream. More specifically, within the first few inches after leaving the slot opening of the pressurized quench chamber, the stream of fibers and quench fluid is rapidly slowed as velocity energy of the quench fluid is transferred to the fibers and the fiber air stream entrains air from atmosphere, resulting in velocities of quench fluid and fibers that are much closer matched than conventional eduction open spinning systems. The fibers have a chance to slow down to a speed lower than their peak spinning speed which causes them to collapse on themselves and interweave and entangle before they reach the conveyor belt, resulting in improved web formation uniformity and isotropicity.
[0030] The distance from the spinneret to the impingement point is comparatively short; thus, the effects of friction between the spinning fibers' velocity and the quench fluid do not create much friction resistance on the fiber bundle compared to conventional systems with long quench and spin line distances. The higher density (compared to atmosphere) acts to remove heat energy faster, but can also lead to higher friction losses. Hence the spin line can be shorter than conventional systems
[0031] The dynamic nature of this fiber and quench fluid “stream” after it exits the slot impingement point is similar in nature to the fiber and air stream in meltblown processes. Therefore, those skilled in the art of forming meltblown nonwoven webs can control the laydown process in a similar manner. An additional advantage of this system is that the velocity energy of the system expands and dissipates very quickly, which means that the lay down speed of the fibers when they land on the conveyor collector are significantly slower than in conventional systems, which is much easier to control and leads to better web uniformity. As the fiber bundle slows down before hitting the belt, the fibers bunch up and fold over on each other, leading to better fiber distribution, which makes a more isotropic web in terms of strength and elongation and visual uniformity of basis weight distribution.
[0032] Referring again to FIG. 1 , a very important element of the invention involves the web forming table 40 positioned below the slot 32 of the quench chamber 20 to receive filaments 16 and form the filaments into a non-woven web. The web forming table 40 comprises a vacuum suction box 42 for pulling down filaments onto a moving mesh wire belt conveyor 44 which transports the as-formed web to the next stage of the process for strengthening the web by conventional techniques to produce the final non-woven fabric web. For example, one possible bonding method could be calendering, 50 . After bonding, the nonwoven fabric can be wound into rolls 60 for ease of shipping to final end user.
[0033] The specific test results listed in the Table below are illustrative of the operation of the present invention. The tests were carried out on apparatus of the type illustrated in FIGS. 1 and 2 having parameters indicated in the Table, a quench zone length of 24 inches from spinneret face to slot opening, slot gap openings as indicated in the Table, and a capillary throughput as indicated in the Table. The polymer spun was 35 MFI polypropylene with a melt temperature of about 235° C. The incoming angle of the combined air knives forming the slot opening was 90°, with an outgoing angle of 180°.
TABLE Quench Air slot Fume pack spin air Press. gap, Exh Low High Avg. Spin press, speed Run # temp F. psig gm/hole/min in. Diam. Denier Denier Denier Well? psi m/min 23 44 7.5 1 0.067 3/16″ 2.2 3.8 3.00 stable 1580 3,000 24 45 10 1 0.067 3/16″ 2.5 4.2 3.35 stable 1600 2,687 25 48 12 1 0.067 3/16″ 2.2 2.8 2.50 stable 1620 3,600 26 50 12 1.21 0.067 none 2.5 3.4 2.95 stable 1810 3,692 27 52 12.5 1.5 0.067 none 2.8 4.2 3.50 stable 2040 3,857 28 51 12.5 0.83 0.067 none 1.7 2.5 2.10 stable 1580 3,557 29 54 12.5 0.55 0.067 none 0.5 2.2 1.35 stable 1320 3,667 30 43 15 0.55 0.05 none 1.2 2.5 1.85 stable 1360 2,676 31 43 15 1 0.05 none 2.8 4.2 3.50 stable 1800 2,571 Conditions common to all runs: 35 MFI polypropylene polymer temperature 230° to 240° C. spinneret with 27 round spinning orifices in a 2″ diameter pattern spinning distance from spinneret face to slot knife edges = 24″ slot entrance vee = 90 degrees and exit flat
[0034] In summary, the foregoing specific examples illustrate the present invention and its operation highlighting spinning advantages. Preferred embodiments include the formation of low basis weight webs from fine polypropylene filaments of under 5 denier and production rates over 200 kg per hour per meter of beam width; point bonding these webs to produce a nonwoven material useful for many applications including (1) liners for sanitary products, (2) limited use garments, (3) surgical drapes and even (4) durable goods.
[0035] Another embodiment would include the formation of webs from fine or coarse filaments of polyester under 15 denier and production rates over 200 kg per hour per meter of beam width; point bonding or area bonding these webs to produce a nonwoven material useful for (1) industrial filtration, (2) automotive carpet, (3) roofing applications, (4) commercial dryer sheets (5) hygiene products.
[0036] The method and apparatus of the present invention are useful to make fine continuous filaments even if they are not formed into a spunbond web. For example, the spun fibers can be collected and used as pillow and cushion stuffing. For this purpose the fibers can be feed directly into the pillow or cushion casing from the slot opening of the quench chamber. Alternatively, the fibers can be baled and sold.
[0037] Thus it is apparent that there has been provided, in accordance with the invention, an improved method and apparatus for forming fine continuous filaments having particular utility in forming nonwoven webs in a manner that that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
[0038] Having described preferred embodiments of a new and improved method and apparatus for forming fine continuous filaments in general and melt spun nonwoven webs in particular, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A method and apparatus for forming nonwoven melt spun webs by spinning a curtain of filaments into a pressurized chamber where they are contacted with pressurized quenching fluid, then using the fluid to draw the filaments through a slot at the bottom of the chamber. The slot is a narrow two dimensional impingement point running the length of the filament curtain where the pressurized quench fluid passes through, escaping to atmosphere. The fluid pressure (potential) energy in the chamber is exchanged for velocity (kinetic) energy at the slot impingement point. The fast moving stream of fluid inside and exiting the slot acts to pull, or draw the filaments through the slot. The fluid and fiber stream is deposited onto a porous collection conveyor belt, forming a fleece web. The invention is more efficient, less complicated, easier to maintain and easier to control than prior systems for melt spinning nonwoven webs. | 3 |
FIELD OF THE INVENTION
This invention relates to marine devices to remotely raise and lower antennae.
BACKGROUND OF THE INVENTION
Prior to the disclosed invention antennae were raised and lowered on marine craft by having a user climb on the side of the vessel to raise and lower the antennae manually. The present invention solves this problem and enables the user to do this remotely.
BRIEF SUMMARY OF THE INVENTION
The present invention includes methods, systems, and other means for raising and lowering antennae. An apparatus for raising and lowering antenna comprises a pivot bar which is immediately adjacent to a T-bracket. The T-bracket is mechanically coupled to a light post and an actuator light post bracket, where the actuator light post bracket is mechanically coupled to an actuator.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 is a perspective view of the invention illustrated in use and in deployed/raised configuration.
FIG. 2 is a perspective view of the invention illustrated in use and in retraced/lowed configuration.
FIG. 3 is an exploded view of the invention.
FIG. 4 is a section view of the invention along line 4 - 4 in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention overcome many of the obstacles associated with raising and lowering antennae, and now will be described more fully hereinafter with reference to the accompanying drawings that show some, but not all embodiments of the claimed inventions. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
FIG. 1 shows the invention in use. Antennae assembly 10 is designed to be mechanically coupled to mounting platform 12 . Antennae assembly 10 comprises pivot bar bracket 30 is mechanically coupled to pivot bar 14 . Pivot bar 14 is immediately adjacent to antenna bracket 20 and T-bracket 16 . Antenna bracket 20 is mechanically coupled to antenna 18 . T-bracket 16 is mechanically coupled to light post 22 and actuator light post bracket 28 . Actuator light post bracket 28 is mechanically coupled to actuator 24 , which is further mechanically coupled to actuator platform bracket 26 . Actuator platform bracket 26 is mechanically coupled to mounting platform 12 .
FIG. 2 shows antennae assembly 10 in use. Actuator 24 is electrically coupled to a 12 V source. The 12 V source is electrically coupled to a switch. The switch can be activated from a remote location either by electrically coupled system or a remote-controlled system. The switches activated actuator 24 expands pushing away light post bracket 28 and folding down light post 22 and antenna 18 as shown.
FIG. 3 shows an exploded view of antennae assembly 10 . Symbol the device a user inserts pivot bar 14 through T-bracket 16 and antenna bracket 20 into pivot bar bracket 30 . In some embodiments pivot bar 14 can be mechanically coupled to T-bracket 16 and antenna bracket 20 by welding, bolting or with any other known coupling technique. As shown here, actuator 24 is mechanically coupled to actuator light post bracket 28 by a bolt.
FIG. 4 is a section view of antennae assembly 10 . As noted above, this invention enables the user to lay down antennae from a remote location. As actuator 24 expands, actuator 24 pushes light post 22 toward mounting platform 12 (not shown). This allows a user to easily set down antennae 18 without having to climb up the side of a boat. | This is directed to systems, processes, machines, and other means that raise and lower an antenna. The invention can utilize an actuator to raise and lower an antenna. | 7 |
This is a continuation of application Ser. No. 08/356,995 filed Dec. 16. 1994, now abandoned.
FIELD OF THE INVENTION
This invention relates to compositions, or mixtures, of fluorinated hydrocarbons and more specifically to azeotropic or azeotrope-like compositions comprising effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like composition. Such compositions are useful as cleaning agents, expansion agents for polyolefins and polyurethanes, refrigerants, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.
BACKGROUND OF THE INVENTION
Fluorinated hydrocarbons have many uses, one of which is as a refrigerant. In refrigeration applications, a refrigerant is often lost during operation through leaks in shaft seals, hose connections, solder joints, and broken lines. In addition, the refrigerant may be released to the atmosphere during maintenance procedures on refrigeration equipment.
Accordingly, it is desirable to use a single fluorinated hydrocarbon or an azeotropic or azeotrope-like composition that includes one or more fluorinated hydrocarbons as a refrigerant. Some nonazeotropic compositions that include one or more fluorinated hydrocarbons may also be used as refrigerants, but they have the disadvantage of changing composition, or fractionating, when a portion of the refrigerant charge is leaked or discharged to the atmosphere. If a non-azeotropic composition contains a flammable component, the blend could become flammable because of such a change in composition. Refrigerant equipment operation could also be adversely affected due to the change in composition and vapor pressure that results from fractionation.
Fluorinated hydrocarbons may also be used as a cleaning agent or solvent to clean, for example, electronic circuit boards. Electronic components are soldered to circuit boards by coating the entire circuit side of the board with flux and thereafter passing the flux-coated board over preheaters and through molten solder. The flux cleans the conductive metal parts and promotes solder fusion, but leave residues on the circuit boards that must be removed with a cleaning agent.
Preferably, cleaning agents should have a low boiling point, nonflammability, low toxicity, and high solvency power so that flux and flux-residues can be removed without damaging the substrate being cleaned. Further, it is desirable that cleaning agents that include a fluorinated hydrocarbon be azeotropic or azeotrope-like so that they do not tend to fractionate upon boiling or evaporation. If the cleaning agent were not azeotropic or azeotrope-like, the more volatile components of the cleaning agent would preferentially evaporate, and the cleaning agent could become flammable or could have less-desirable solvency properties, such as lower rosin flux solvency and lower inertness toward the electrical components being cleaned. The azeotropic property is also desirable in vapor degreasing operations because the cleaning agent is generally redistilled and reused for final rinse cleaning.
Azeotropic or azeotrope-like compositions of fluorinated hydrocarbons are also useful as blowing agents in the manufacture of close-cell polyurethane, phenolic and thermoplastic foams. Insulating foams require blowing agents not only to foam the polymer, but more importantly to utilize the low vapor thermal conductivity of the blowing agents, which is an important characteristic for insulation value.
Aerosol products employ both single component fluorinate hydrocarbons and azeotropic or azeotrope-like compositions of fluorinated hydrocarbons as propellant vapor pressure attenuators in aerosol systems.
Azeotropic mixtures, with their constant compositions and vapor pressures are useful as solvents and propellants in aerosols.
Azeotropic or azeotrope-like compositions that include fluorinated hydrocarbons are also useful as heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids such as for heat pumps, inert media for polymerization reactions, fluids for removing particulates from metal surfaces, and as carrier fluids that may be used, for example, to place a fine film of lubricant on metal parts.
Azeotropic or azeotrope-like compositions that include fluorinated hydrocarbons are further useful as buffing abrasive detergents to remove buffing abrasive compounds from polished surfaces such as metal, as displacement drying agents for removing water such as from jewelry or metal parts, as resist-developers in conventional circuit manufacturing techniques employing chlorine-type developing agents, and as strippers for photoresists when used with, for example, a chlorohydrocarbon such as 1,1,1-trichloroethane or trichloroethylene.
Some of the fluorinated hydrocarbons that are currently used in these applications have been theoretically linked to depletion of the earth's ozone layer. What is needed, therefore, are substitutes for fluorinated hydrocarbons that have low ozone depletion potentials.
SUMMARY OF THE INVENTION
The present invention relates to the discovery that a mixture of perfluoroethane and trifluoromethane is a drop-in replacement refrigerant for R503, which is a mixture of trifluoromethane and chlorotrifluoromethane. The invention also relates to the discovery of azeotropic or azeotrope-like compositions comprising effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like composition.
DETAILED DESCRIPTION
R-503 is a mixture of trifluoromethane (R-23) and chlorotrifluoromethane (R-13). R-13 contains chlorine which has been theoretically linked to depletion of the Earth's ozone layer, and therefore it is desirable to find a replacement for R-503 that is chlorine-free. It has been discovered that certain mixtures of perfluoroethane (R-116) and R-23 can be used as a drop in replacement refrigerant for R-503. Specifically, as shown below, such mixtures include a mixture of 54 weight percent R-116 and 46 weight percent R-23.
The azeotropic or azeotrope-like compositions, or mixtures, of the present invention comprise effective amounts of perfluoroethane (FC-116, or CF 3 -CF 3 , boiling point=-78.3° C.) and trifluoromethane (HFC-23, or CHF 3 , boiling point=-82.1° C.), nitrous oxide (N 2 O, boiling point=-88.5° C.), carbon dioxide (CO 2 , boiling point=-78.5° C.), or fluoromethane (HFC-41, or CH 3 F, boiling point=-78.4° C.) to form substantially constant boiling, azeotropic or azeotrope-like compositions.
Effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like composition, when defined in terms of weight percent of the components at a specific pressure or temperature, include the following.
Substantially constant-boiling, azeotropic or azeotrope-like compositions of perfluoroethane and trifluoromethane comprise about 40 to 65 weight percent perfluoroethane and 35 to 60 weight percent trifluoromethane at 100 psia (689.5 kPa). These compositions boil at about -46.4 +/-0.5° C. A preferred composition of the invention is the azeotrope which comprises about 53.8 weight percent perfluoroethane and about 46.2 weight percent trifluoromethane and which boils at -46.5° C. at 100 psia, and which comprises about 55.9 weight percent perfluoroethane and about 44.1 weight percent trifluoromethane and which boils at -63.55° C. at 49.316 psia.
Substantially constant boiling, azeotropic or azeotrope-like compositions of perfluoroethane and nitrous oxide comprise about 35 to 55 weight percent perfluoroethane and about 45 to 65 percent nitrous oxide at 100 psia. These compositions boil at about -51.1 +/-0.5° C. A preferred composition of the invention is the azeotrope which comprises about 45.3 weight percent perfluoroethane and about 54.7 weight percent nitrous oxide and which boils at -51.2° C. at 100 psia, and which comprises about 44.8 weight percent perfluoroethane and about 55.2 weight percent nitrous oxide and which boils at -45.55° C. at 123.3 psia.
Substantially constant boiling, azeotrope or azeotrope-like compositions of perfluoroethane and carbon dioxide comprise about 45 to 60 weight percent perfluoroethane and about 40 to 55 weight percent carbon dioxide at 100 psia. These compositions boil at about -52.2 +/-0.5° C. A preferred composition of the invention is the azeotrope which comprises about 51.4 weight percent perfluoroethane and about 48.6 weight percent carbon dioxide and which boils at 52.2° C. at 100 psia, and which comprises about 47.9 weight percent perfluoroethane and about 52.1 weight percent carbon dioxide and which boils at -45.55° C. at 138.1 psia.
Substantially constant boiling, azeotrope or azeotrope-like compositions of perfluoroethane and fluoromethane comprise about 78 to 82 weight percent perfluoroethane and 18 to 22 weight percent fluoromethane at 100 psia. These compositions boil at about -47.7 +/-0.5° C. A preferred composition of the invention is the azeotrope which comprises about 80.3 weight percent perfluoroethane and 19.7 weight percent fluoromethane and which boils at -47.6° C. at 100 psia, and which comprises about 80.2 weight percent perfluoroethane and 19.8 weight percent fluoromethane and which boils at -45.55° C. at 108.2 psia.
Effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like composition can also be defined as including amounts of these components such that the difference in dew point temperature and bubble point temperature of the composition is less than or equal to 1° C. It is recognized in the art that a small difference, such as 1° C., between the dew point temperature and the bubble point temperature of a composition at a particular pressure is an indication that the composition is azeotropic or azeotrope-like. It has been found unexpectedly that compositions some distance away from the true azeotropes of FC-116 and HFC-23, or FC-116 and N 2 O, or FC-116 and CO 2 , or FC-116 and HFC-41 have differences in dew point and bubble point temperature of less than or equal to about 1° C.
Therefore, included in this invention are compositions of effective amounts of FC-116 and HFC-23 or compositions of effective amounts of FC-116 and N 2 O, or compositions of effective amounts of FC-116 and CO 2 , or compositions of effective amounts of FC-116 and HFC-41, such that the compositions have a difference in dew point temperature and bubble point temperature of less than or equal to 1° C. Such compositions include binary compositions of about 40 to 65 weight percent FC-116 and about 35 to 60 weight percent HFC-23; binary compositions of about 35 to 55 weight percent FC-116 and about 45 to 65 weight percent N 2 O; binary compositions of about 45 to 60 weight percent FC-116 and about 40 to 55 weight percent CO 2 ; and binary compositions of about 78 to 82 weight percent FC-116 and about 18 to 22 weight percent HFC-41, all at 100 psia.
For purposes of this invention, "effective amount" is defined as the amount of each component of the inventive compositions which, when combined, results in the formation of an azeotropic or azeotrope-like composition. This definition includes the amounts of each component, which amounts may vary depending on the pressure applied to the composition so long as the azeotropic or azeotrope-like compositions continue to exist at the different pressures, but with possible different boiling points.
Therefore, effective amount includes the amounts, such as may be expressed in weight percentages, of each component of the compositions of the instant invention which form azeotropic or azeotrope-like compositions at pressures other than the pressure described herein.
By "azeotropic or azeotrope-like" composition is meant a constant boiling, or substantially constant boiling, liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotropic or azeotrope-like composition is that the vapor produced by partial evaporation or distillation of the liquid has substantially the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without substantial composition change. Constant boiling or substantially constant boiling compositions, which are characterized as azeotropic or azeotrope-like, exhibit either a maximum or minimum boiling point, as compared with that of the nonazeotropic mixtures of the same components.
For the purposes of this discussion, azeotropic or constant-boiling is intended to mean also essentially azeotropic or essentially-constant boiling. In other words, included within the meaning of these terms are not only the true azeotropes described above, but also other compositions containing the same components in different proportions, which are true azeotropes at other temperatures and pressures, as well as those equivalent compositions which are part of the same azeotropic system and are azeotrope-like in their properties. As is well recognized in this art, there is a range of compositions which contain the same components as the azeotrope, which will not only exhibit essentially equivalent properties for refrigeration and other applications, but which will also exhibit essentially equivalent properties to the true azeotropic composition in terms of constant boiling characteristics or tendency not to segregate or fractionate on boiling.
It is possible to characterize, in effect, a constant boiling admixture which may appear under many guises, depending upon the conditions chosen, by any of several criteria:
The composition can be defined as an azeotrope of A, B, C (and D . . . ) since the very term "azeotrope" is at once both definitive and limitative, and requires that effective amounts of A, B, C (and D. . . ) for this unique composition of matter which is a constant boiling composition.
It is well known by those skilled in the art, that, at different pressures, the composition of a given azeotrope will vary at least to some degree, and changes in pressure will also change, at least to some degree, the boiling point temperature. Thus, and azeotrope of A, B, C (and D. . . ) represents a unique type of relationship but with a variable composition which depends on temperature and/or pressure. Therefore, compositional ranges, rather than fixed compositions, are often used to define azeotropes.
The composition can be defined as a particular weight percent relationship or mole percent relationship of A, B, C (and D. . . ), while recognizing that such specific values point out only one particular relationship and that in actuality, a series of such relationships, represented by A, B, C (and D. . . ) actually exist for a given azeotrope, varied by the influence of pressure.
An azeotrope of A, B, C (and D. . . ) can be characterized by defining the compositions as an azeotrope characterized by a boiling point at a given pressure, thus giving identifying characteristics without unduly limiting the scope of the invention by a specific numerical composition, which is limited by and is only as accurate as the analytical equipment available.
The azeotrope or azeotrope-like compositions of the present invention can be prepared by any convenient method including mixing or combining the desired amounts. A preferred method is to weigh the desired component amounts and thereafter combine them in an appropriate container.
Specific examples illustrating the invention are given below. Unless otherwise stated therein, all percentages are by weight. It is to be understood that these examples are merely illustrative and in no way are to be interpreted as limiting the scope of the invention.
FC-116 AND HFC-23
EXAMPLE 1
A phase study was made on perfluoroethane and trifluoromethane, wherein the composition was varied and the vapor pressures measured, at a constant temperature of -63.55° C. An azeotropic composition was obtained as evidenced by the maximum vapor pressure observed and was identified as follows:
Perfluoroethane=55.9 weight percent
Trifluoromethane=44.1 weight percent
Vapor pressure=49.316 psia (340.0 kPa) at -63.55° C.
EXAMPLE 2
Phase studies on perfluoroethane and trifluoromethane at other temperatures and pressures disclose the following azeotropic compositions:
Perfluoroethane=53.8 weight percent
Trifluoromethane=46.2 weight percent
Vapor pressure=100 psia at -46.5° C.
Perfluoroethane=41.1 weight percent
Trifluoroethane=58.9 weight percent
Vapor pressure=14.7 psia (101.3 kPa) at -86.9° C.
EXAMPLE 3
The novel azeotropic or azeotrope-like compositions of the present invention exhibit a higher vapor pressure than either of the two constituents and exhibit dew and bubble points with virtually no temperature differentials. As is well known in the art, a small difference between dew point and bubble point temperatures is an indication of the azeotrope-like behavior of compositions.
A study of dew point and bubble point temperatures for various compositions indicates that the differences in dew point and bubble point temperatures of the azeotrope-like compositions of the invention are very small with respect to the differences in dew point and bubble point temperatures of several known, nonazeotropic, binary compositions, namely, (50+50) weight percent compositions of pentafluoroethane (HFC-125) and 1,1,1,2-tetrafluoroethane (HFC134a), and (50+50) weight percent compositions of chlorodifluoromethane (HCFC22) and 1-chloro-1,1-difluoroethane (HCFC-142b). These data confirm the azeotrope-like behavior of the compositions of this invention.
TABLE 1______________________________________ Temperatures (°C.) at 100 psiaRefrigerant Composition Bubble Point Dew Point Delta T______________________________________HFC-125 + HFC-134a 15.6 19.8 4.2(50 + 50)HCFC-22 + HFC-142b 23.3 33.8 10.5(50 + 50)FC-116 + HFC-23 -46.4 -46.4 0.0(54 + 46)FC-116 + HFC-23 -46.3 -45.5 0.8(40 + 60)FC-116 + HFC-23 -46.5 -46.4 0.1(50 + 50)FC-116 + HFC-23 -46.4 -46.1 0.3(60 + 40)FC-116 + HFC-23 -46.3 -45.4 0.9(65 + 35)______________________________________ Temperatures (°C.) at 14.7 psiaRefrigerant Composition Dew Point Bubble Point Delta T______________________________________FC-116 + HFC-23 -86.0 -86.8 0.8(69 + 31)FC-116 + HFC-23 -85.9 -86.8 0.9(44 + 56)FC-116 + HFC-23 -86.7 -86.9 0.2(54 + 46)______________________________________
EXAMPLE 4
A study compares the refrigeration properties of an azeotropic composition of the invention with Refrigerant-503, which is 40.1 weight percent R-23 and 59.9 weight percent R-13, and perfluoroethane (FC-116). The refrigeration capacity is based on a compressor with a fixed displacement of 3.5 cubic feet per minute. The data are based on a refrigeration cycle with a suction line heat exchanger.
TABLE 2______________________________________COMPARISON OF REFRIGERATION PERFORMANCES Refrig. FC-116/HFC-23 (wt percents) 503 FC-116 (58/42) (54/46) (50/50)______________________________________Evaporator -80.0 -80.0 -80.0 -80.0 -80.0Temp, °F.Evaporator 54.4 32.0 52.8 52.6 52.0Pres, psiaCondenser -10.0 -10.0 -10.0 -10.0 -10.0Temp, °F.Condenser 218.0 138.3 213.4 214.0 213.7Pres, psiaReturn Gas -60.0 -60.0 -60.0 -60.0 -60.0Temp, °F.Compressor 51.8 7.2 33.1 35.9 38.8Discharge, °F.Coefficient 3.8 3.6 3.7 3.7 3.7of PerformanceCapacity 204 113 187.9 190 191.3Btu/min______________________________________
Capacity is intended to mean the change in enthalpy of the refrigerant in the evaporator per pound of refrigerant circulated, i.e., the heat removed by the refrigerant in the evaporator per time.
Coefficient of performance (COP) is intended to mean the ratio of the capacity to the compressor work. It is a measure of refrigerant energy efficiency.
For a refrigeration cycle typified by the above conditions, both the COP and capacity increase by adding HFC-23 to FC-116. These results show that a composition of FC-116 and HFC-23 improves the capacity and energy efficiency of a refrigeration cycle when compared to FC-116 alone.
FC-116 AND NITROUS OXIDE
EXAMPLE 5
A phase study was made on perfluoroethane and nitrous oxide, wherein the composition was varied and the vapor pressures measured, at a constant temperature of -45.55° C. An azeotropic composition was obtained as evidenced by the maximum vapor pressure observed and was identified as follows:
Perfluoroethane=44.8 weight percent
Nitrous oxide=55.2 weight percent
Vapor pressure=123.31 (850.2 kPa) at -45.55° C.
EXAMPLE 6
A second phase study on perfluoroethane and nitrous oxide discloses the following azeotropic composition:
Perfluoroethane=45.3 weight percent
Nitrous oxide=54.7 weight percent
Vapor pressure=100 psia at -51.2° C.
EXAMPLE 7
A study as in Example 3 of dew point temperatures and bubble point confirms the azeotropic or azeotrope-like behavior of compositions of FC-116 and N 2 O.
TABLE 3______________________________________ Temperatures (°C.) at 100 psiaRefrigerant Composition Bubble Point Dew Point Delta T______________________________________HFC-125 + HFC-134a 15.6 19.8 4.2(50 + 50)HCFC-22 + HCFC-142b 23.3 33.8 10.5(50 + 50)FC-116 + N.sub.2 O -51.1 -50.8 0.3(35 + 65)FC-116 + N.sub.2 O -51.2 -51.0 0.2(40 + 60)FC-116 + N.sub.2 O -51.2 -51.0 0.2(50 + 50)FC-116 + N.sub.2 O -51.1 -50.6 0.5(55 + 45)______________________________________
EXAMPLE 8
A study as in Example 4 compares the refrigeration properties of an azeotropic composition of the invention with Refrigerant-503 and perfluoroethane (FC-116).
TABLE 4______________________________________COMPARISON OF REFRIGERATION PERFORMANCES Refrig. FC-116/N.sub.2 O (wt. percents) 503 FC-116 (45/55)______________________________________Evaporator -80.0 -80.0 -80.0Temp, °F.Evaporator 54.4 32.0 65.2Pres, psiaCondenser -10.0 -10.0 -10.0Temp, °F.Condenser 218.0 138.3 257.0Pres, psiaReturn Gas -60.0 -60.0 -60.0Temp, °F.Compressor 51.8 7.2 58.6Discharge, °F.Coefficient 3.8 3.6 3.9of PerformanceCapacity 204 113 252Btu/min______________________________________
For a refrigeration cycle typified by the above conditions, the capacity and the COP of FC-116 is increased by adding N 2 O to the FC-116. These results show that a composition of FC-116 and N 2 O improves the capacity of a refrigeration cycle when compared to Refrigerant 503.
FC-116 AND CARBON DIOXIDE
EXAMPLE 9
A phase study was made on perfluoroethane and carbon dioxide, wherein the composition was varied and the vapor pressure measured, at a constant temperature of -45.55° C. An azeotropic composition was obtained as evidenced by the maximum vapor pressure observed and was identified as follows:
Perfluoroethane=47.9 weight percent
Carbon dioxide=52.1 weight percent
Vapor pressure=138.1 psia (952.2 kPa) at -45.55° C.
EXAMPLE 10
A second phase study on perfluoroethane and carbon dioxide discloses the following azeotropic composition:
Perfluoroethane=51.4 weight percent
Carbon dioxide=48.6 weight percent
Vapor pressure=100 psia at -52.2° C.
EXAMPLE 11
A study as in Example 3 shows that novel azeotropic or azeotrope-like compositions of FC-116 and CO 2 exhibit dew and bubble points with virtually no temperature differentials.
TABLE 5______________________________________ Temperatures (°C.) at 100 psiaRefrigerant Composition Bubble Point Dew Point Delta T______________________________________HFC-125 + HFC-134a 15.6 19.8 4.2(50 + 50)HCFC-22 + HFC-142b 23.3 33.8 10.5(50 + 50)FC-116 + CO.sub.2 -52.2 -52.0 0.2(45 + 55)FC-116 + CO.sub.2 -52.2 -52.2 0.0(50 + 50)FC-116 + CO.sub.2 -52.2 -51.6 0.6(60 + 40)______________________________________
EXAMPLE 12
A study as in Example 4 compares the refrigerant properties of the azeotropic compositions of the invention with Refrigerant-503 and perfluoroethane (FC-116).
TABLE 6______________________________________ Refrig. FC-116/CO.sub.2 (wt. percents) 503 FC-116 (50/50)______________________________________Evaporator -80.0 -80.0 -80.0Temp, °F.Evaporator 54.4 32.0 61.6Pres, psiaCondenser -10.0 -10.0 -10.0Temp, °F.Condenser 218.0 138.3 312.0Pres, psiaReturn Gas -60.0 -60.0 -60.0Temp, °F.Compressor 51.8 7.2 74.4Discharge, °F.Coefficient 3.8 3.6 3.2of PerformanceCapacity 204 113 236Btu/min______________________________________
For a refrigeration cycle typified by the above conditions, the capacity increases by adding CO 2 to FC-116. These results show that a composition of FC116 and CO 2 improves the capacity of a refrigeration cycle when compared to FC116 alone and to Refrigerant 503.
FC-116 AND HFC-41
EXAMPLE 13
A phase study was made on perfluoroethane and fluoromethane, wherein the composition was varied and the vapor pressures measured at a constant temperature of -45.55° C. An azeotropic composition was obtained as evidenced by the maximum vapor pressure observed and was identified as follows:
Perfluoroethane=80.2 weight percent
Fluoromethane=19.8 weight percent
Vapor pressure=108.21 psia (746.1 kPa) at -45.55° C.
EXAMPLE 14
A second phase study on perfluoroethane and fluoromethane discloses the following azeotropic composition:
Perfluoroethane=80.3 weight percent
Fluoroethane=19.7 weight percent
Vapor pressure=100 psia at -47.6° C.
EXAMPLE 15
A study as in Example 3 shows that novel azeotropic or azeotrope-like compositions of FC-116 and HFC-41 exhibit dew and bubble point temperatures with small temperature differentials.
TABLE 7______________________________________ Temperatures (°C.) at 100 psiaRefrigerant Composition Bubble Point Dew Point Delta T______________________________________HFC-125 + HFC-134a 15.6 19.8 4.2(50 + 50)HCFC-22 + HCFC-142b 23.3 33.8 10.5(50 + 50)FC-116 + HFC-41 -47.7 -47.3 0.3(82 + 18)FC-116 + HFC-41 -47.7 -47.1 0.6(78 + 22)FC-116 + HFC-41 -47.7 -47.7 0.0(80 + 20)______________________________________
EXAMPLE 16
A study as in Example 4 compares the refrigeration properties of the azeotropic compositions of the invention with Refrigerant 503 and FC-116.
TABLE 8______________________________________COMPARISON OF REFRIGERATION PERFORMANCES Refrig. FC-116/HFC-41 (wt. percents) 503 FC-116 (80/20)______________________________________Evaporator -80.0 -80.0 -80.0Temp, °F.Evaporator 54.4 32.0 53.7Pres, psiaCondenser -10.0 -10.0 -10.0Temp, °F.Condenser 218.0 138.3 221.0Pres, psiaReturn Gas -60.0 -60.0 -60.0Temp, °F.Compressor 51.8 7.2 36.0Discharge, °F.Coefficient 3.8 3.6 3.5of PerformanceCapacity 204 113 184Btu/min______________________________________
For a refrigeration cycle typified by the above conditions, the capacity increases by adding HFC-41 to FC-1 16. These results show that a composition of FC-116 and HFC-41 increases the capacity of a refrigeration cycle versus FC-116 alone.
The novel azeotrope or azeotrope-like compositions of FC-116 and HFC-23 or FC-116 and N 2 O or FC-116 and CO 2 or FC-116 and HFC-41 may be used to produce refrigeration by condensing the compositions and thereafter evaporating the condensate in the vicinity of the body to be cooled.
The novel azeotrope or azeotrope-like compositions may also be used to produce heat by condensing the refrigerant in the vicinity of the body to be heated and thereafter evaporating the refrigerant.
The use of azeotropic or azeotrope-like compositions eliminates the problem of component fractionation and handling in systems operations, because these compositions behave essentially as a single substance. Several of the novel azeotrope-like compositions also offer the advantage of being essentially nonflammable.
In addition to refrigeration applications, the novel constant boiling compositions of the invention are also useful as aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, expansion agents for polyolefins and polyurethanes and as power cycle working fluids.
Additives such as lubricants, corrosion inhibitors, stabilizers, dyes, and other appropriate materials may be added to the novel compositions of the invention for a variety of purposes provided they do not have an adverse influence on the composition, for their intended applications. | Compositions of perfluoroethane and trifluoromethane are disclosed as acceptable drop in replacements for R-503.
Also disclosed are azeotropic or azeotrope-like compositions of admixtures of effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like composition.
Such compositions are useful as cleaning agents, expansion agents for polyolefins and polyurethanes, refrigerants, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of co-pending International Application No. PCT/US92/0534, filed on Jul. 01, 1992, entitled "Process and Chiral Intermediates for Thiazole Antidiabetics," which is a continuation of U.S. Ser. No. 07/733,548, filed on Jul. 22, 1991, entitled "Process and Chiral Intermediates for Thiazole Antidiabetics" (now abandoned).
BACKGROUND OF THE INVENTION
The compound depicted in formula I and related compounds have been reported in U.S. 4,886,814 to have utility as antidiabetics. ##STR1##
The present invention relates to novel key intermediates in the synthesis of compound I, said intermediates being (R)-4-(2-bromo-1-hydroxyethyl)-2-trifluoromethylthiazole (II) and (S)-4-oxiranyl-2-trifluoromethylthiazole (III), and to an enantioselective reduction process for the preparation of these compounds which results in their being obtained essentially free of their enantiomeric forms.
The racemic form of the bromohydrin (II), depicted below, has been reported. Within the same reference, the racemic form of the epoxide has also been reported. However, the S-bromohydrin (II) and the (S)-epoxide (III) are both previously unknown in their purified chiral forms.
It is advantageous to prepare the bromohydrin and epoxide in optically pure form since the final product of formula I has the S configuration at the hydroxyl-substituted chiral center. Therefore, a process whereby the desired stereochemistry is directly obtained is highly desirable.
The stereoselective reduction process of this invention involves the use of a borane reducing agent and a chiral oxazaborolidine catalyst. Corey, et al. (Journal of the American Chemical Society, 1987, 109, 5551-3 and 7925-6) have described generally the reduction of a limited number of ketones with boranes utilizing chiral oxazaborolidines to elicit enantioselectivity. However, recent studies by Jones, et al. (Journal of Organic Chemistry, 1991, 56, 763-9) have demonstrated that the method loses its effectiveness when molecules possessing borane coordination sites are present in the reaction mixture. Examples of compounds containing borane coordination sites include but are not limited to such compounds as boronic acids, boroxines, prolinols, amines, thiazoles and oxazoles. This loss of effectiveness is manifested in diminished enantioselectivity. The present invention is directed to a process in which the deleterious effect of said borane coordination sites has been overcome.
SUMMARY OF THE INVENTION
This invention is directed to (R)-4-(2-bromo-1-hydroxyethyl)-2-trifluoromethylthiazole (II) and (S)-4-oxiranyl-2-trifluoromethylthiazole (III), both compounds being substantially free of their corresponding R enantiomer. ##STR2##
Also embraced by the invention is a process for the enantioselective preparation of the above-mentioned compounds from the achiral ketone precursor IV. ##STR3## Thus, said ketone IV is enantioselectively reduced using a borane reducing agent such as borane methyl sulfide complex, catecholborane or borane-tetrahydrofuran in the presence Of a chiral oxazaborole catalyst in a cyclic ether solvent such as dioxane or tetrahydrofuran to afford, in essentially optically pure form, (R)-4-(2-bromo-1-hydroxyethyl)-2-trifluoromethylthiazole (II). A preferred reducing agent is borane-methyl sulfide complex; a preferred catalyst is (R)-tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaborole and a preferred solvent is tetrahydro solvent is tetrahydrofuran. The process of this invention results in achievement of a high percent enantiomeric excess.
The bromohydrin (II) is further elaborated to the optically pure (S)-4-oxiranyl-2trifluoromethylthiazole (III) by treatment with sodium hydroxide. This dehydrobromination affords the cyclized product without racemization of the chiral center.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides two novel, optically pure, key intermediates of structures II and III, depicted above. The depicted compounds, (R)-4-(2-bromo-1-hydroxyethyl)-2-trifluoromethylthiazole (II) and (S)-4-oxiranyl-2-trifluoromethylthiazole(III) are provided in optically pure form, substantially free of their corresponding enantiomers.
Also embraced by the invention is the enantioselective reduction process whereby compound II is prepared. ##STR4##
The process, see Scheme I, comprises treating the ketone, 4-bromoacetyl-2trifluoromethylthiazole, with about 1.1 to 2.0 molar equivalents of a borane reducing agent in the presence of a chiral oxazaborolidine catalyst in a cyclic ether solvent at -20° C. to +40° C. Examples of suitable borane reducing agents include but are not limited to borane methyl sulfide complex, catecholborane, and borane tetrahydrofuran. Most preferred is the system in which borane methyl sulfide complex is utilized. The term "chiral oxazaborolidine catalyst" is meant to define compounds of general structure V, wherein X is (C 1 -C 4 )alkyl, phenyl or (C 7 -C 9 )phenylalkyl. Preferred is the case where X is methyl, n-butyl or phenyl. Most preferred is the instance in which X is methyl. The R stereochemistry depicted in the catalyst of formula V is critical to the production of the desired R stereochemistry in the product bromohydrin (II). The term "cyclic ether solvent" is defined as any C-4 to C-6 cycloalkane containing either one or two oxygens Within the ring, such as tetrahydrofuran or dioxane. More preferred is tetrahydrofuran. The ideal temperature for the reaction is ambient temperature, ambient temperature being defined as the temperature of the room within which the reaction is being carded out, when that temperature falls within the range of +18° C. to +25° C.
Progress of the reaction is monitored by methods well-known to those skilled in the art. Such monitoring indicates that the reduction is generally complete after a period of time ranging from 15 minutes to 3 hours, including addition of reagents. At this time the reaction mixture is cooled to 0° C. and quenched by the careful (dropwise) addition of methanol. Isolation and purification is easily accomplished by means of well-established procedures known to those skilled in the art, affording the (R)-bromohydrin (II) substantially free of its S enantiomer.
The process further comprises treatment of the optically pure (R)-4-(2-bromo-1-hydroxyethyl)-2-trifluoromethyl-thiazole with sodium hydroxide to effect dehydrobromination and concomitant cyclization to the optically pure (S)-4-oxiranyl-2-trifluoromethylthiazole (III), without racemization of the chiral center.
The ketone starting material (IV) for this process is readily prepared from commercially available materials by following the known procedure (U.S. 4,886,814). Reaction of trifluoromethyl acetamide with Lawesson's Reagent in dimethoxyethane yields the thioacetamide derivative, which is transformed to 4-bromoacetyl-2trifluoromethylthiazole (IV) by reaction with 1,4-dibromo-2,3-butanedione in acetonitrile.
The (S)-epoxide (III ), which is the product of the process of the present invention, is elaborated to the aforementioned antidiabetic agent of formula I by reaction with the compound of formula VI in methanol to yield the epoxide-ring-opened product (VII) as shown in Scheme II (supra).
The chemistry used to elaborate the ring-opened product (VII) to the final product is also reported in the aforementioned patent. Thus, reaction of VII with HCI(g) in ethanol deprotects the phenol to give VIII, which is reacted with methylbromoacetate and potassium carbonate in acetone to give the O-alkylated material (IX). This material is hydrogenated with palladium on carbon in methanol and the resulting amine is saponified with 1N sodium hydroxide in methanol to afford the desired product (I). ##STR5##
Elaboration to the antidiabetic compound of formula I is also accomplished by reaction of epoxide III with methyl O-[4-(2-aminopropyl)phenyl]glycolate to afford the penultimate compound of Scheme II directly. This compound is simply saponified with 1N NaOH to give compound I.
Methods of using compound I as an antidiabetic agent in humans are described in U.S. Pat. No. 4,886,814.
This invention is further illustrated by the following examples. However, it should be understood that the invention is not limited to the specific details of these examples.
EXAMPLE 1
(R)-4-(2-Bromo- 1-hydroxyethyl-2 -trifluoromethylthiazole
Borane methyl sulfide complex (2M in THF, 50 mL, 100 mmol) and 4-bromoacetyl-2-trifluoromethylthiazole (20.15 g, 73.5 mmol) were added separately and simultaneously over one our to (R)-tetrahydro-1,3,3-triphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaborole (1.2 g, 3.53 mmol) in tetrahydrofuran (50 mL) at ambient temperature. After the reduction was complete the reaction mixture was cooled to 0° C. and quenched with methanol (dropwise addition of 115 mL) while maintaining the temperature at less than or equal to 13° C. The quenched reaction mixture was stirred at 5° to 10° C. for ten minutes and then at ambient temperature for 45 minutes. The solvents were removed in vacuo and the residue was dissolved in methylene chloride (180 mL), washed with pH 4 aqueous phosphate buffer (180 mL), water (180 mL) and dried (MgSO 4 ). The solvent was removed in vacuo to afford 4-(2-bromo-1-hydroxyethyl)-2-trifluoromethylthiazole as an amber oil (20.14 g, 99%, 90% ee). 1 NMR (300 MHz, CDCl 3 ): δ 7.61 (s, 1H), 5.13 (dd, J=4 Hz, J=7 Hz, 1H), 3.91 (dd, J=4 Hz, J=10 Hz, 1H), 3.70 (dd, J=7 Hz, J=10 Hz, 1H), 2.88 (bs, 1H).
EXAMPLE 2
(R)-4-(2-Bromo) 1 -hydroxyethyl-2-trifluorothiazole
Borane-methyl sulfide complex (2M in THF, 1.4 eq., 2.74 mL, 5.48 mmol) was added dropwise to a solution of 4-bromoacetyl-2-trifluoromethylthiazole (2.05 g, 7.48 mmol)and(R)-tetrahydro- 1 -methyl-3,3-diphenyl- 1H, 3H-pyrrolo [1,2 -c ][1,3,2]oxazaborole (56 mg, 0.20 mmol) in tetrahydrofuran (16 mL) at ambient temperature. After addition was complete (one hour), the reaction mixture was stirred for an additional 75 minutes, cooled to 0° C., and quenched by dropwise addition of methanol (10 mL). The quenched reaction mixture was stirred for 15 minutes at 0° C. and for 45 minutes at ambient temperature. The solvents were removed in vacuo and the residue was partitioned between methylene chloride (20 mL) and pH4 aqueous phosphate buffer (20 mL). The layers were separated and the organic phase was washed with water (20 mL) and dried (MgSO 4 ) to afford the crude product as a yellow oil (1.10 g, 102%, 94% ee), αD=-19.25° (C=1 acetone). 1 HNMR (300 MHz, CDCl 3 ): δ7.61 (s, 1H), 5.13 (dd, J=4 Hz, J-7 Hz, 1H), 3.91 (dd, J=4 Hz, J=10 Hz, 1H), 3.70 (dd, J=7 Hz, J=10 Hz, 1H), 2.88 (be, 1H).
EXAMPLE 3
(R)-4-(2-Bromo)- 1-hydroxyethyl-2-trifluoroethylthiazole
Borane-methyl sulfide complex (2M in THF, 1.4 eq., 5.2 mL, 10.6 mmol) was added dropwise to a solution of 4-bromoacetyl-2-trifluorothiazole (2.05 g, 7.48 mmole) and (R)-tetrahydro-1 -n-butyl-3,3-diphenyl-1H,3H-pyrrolo[1,2 -c][1,3,2]oxazaborole (129 mg, 0.40 mmol) in tetrahydrofuran (30 mL) at ambient temperature. After addition was complete (one hour), the reaction mixture was stirred an additional one hour, cooled to 0° C., and quenched by dropwise addition of Methanol (20 mL). The quenched reaction mixture was stirred for 16 hours and allowed to warm to ambient temperature. The solvents were removed in vacuo and the residue was partitioned between methylene chloride (30 mL) and pH 4 aqueous phosphate buffer (30 mL). The layers were separated and the organic phase was washed with water (30 mL) and dried (MgSO 4 ) to afford the crude product as a pale yellow oil (2.083 g, 100%, 88% ee). [α] D =17.7° (C=1 acetone). 1 HNMR (300 MHz, CDCl 3 ): δ7.61 (s, 1H), 5.13 (dd, J=4 Hz, J=7 Hz, 1H), 3.91 (dd, J=4 Hz, J=10 Hz, 1H), 3.70 (dd, J=7 Hz, J=10 Hz, 1H), 2.88 (bs,
EXAMPLE 4
(S)-4-Oxiranyl-2 -trifluoromethylthiazole
The title compound of example one (20.07 g, 72.7 mmol), neat, with vigorous stirring, was treated with sodium hydroxide (4N, 18.7 mL) at ambient temperature. The reaction mixture was stirred for ten minutes after which time methylene chloride (200 mL) and water (200 mL) were added. The layers were separated and the organic layer was washed three times with 200 mL of water and dried (MgSO 4 ). The solvent was removed in vacuo and the residue was purified on silica gel (elution with methylene chloride) to afford 4-oxiranyl-2-trifluoromethylthiazole as a light yellow oil (10.15 g, 71%), [α]=-10.96° (C=1.31, CH 2 , Cl 2 ). | Two novel optically pure intermediates, (R)-4-(2-bromo-1-hydroxyethyl)-2- trifluoro(-)methylthiazole and (S)-4-oxiranyl-2-trifluoromethylthiazole, which have utility in the synthesis of a potent class of antidiabetic agents. The invention also embraces an enantioselective reduction process for their preparation. | 2 |
FIELD OF THE INVENTION
The present invention relates to a yarn clamp assembly of a knitting machine, and more particularly to a yarn clamp assembly of a knitting machine that enhances the fixation of the bottom of additional yarns.
BACKGROUND OF THE INVENTION
As the weaving techniques advance, various different fabrics such as the invention of the towel fabrics are produced for our use. The soft surface and strong water absorbability function of the towel fabrics make the towel fabric to be used extensively in daily products. Many knitting methods primarily use a normal knitting method to introduce yarns with additional effects to form a soft surface as disclosed in R.O.C. Pat. Publication Nos. 300565, and 388416 and 345204 filed by the inventor of the present invention. These patents disclose a wrap knitting method and a counter wrap knitting method to knit a single knitted towel fabric structure to produce a loop with soft surface. As we all know, the surface of the towel fabric is comprised of many loops which are different from the base fabric. Since the bottoms of these loops are fixed into the base fabric when the base yarns forming the base fabric are woven, and another end of the loop is a free end so that the surface becomes soft and the water content is increased. However, the towel fabric has a shortcoming that the loops will be loosened from the base fabric and damage the towel fabric if a loop is pulled. Therefore, the prior art adds glues on the base fabric to increase the coupling strength between the loop and the base fabric. However, the towel fabric so produced is not applicable for daily use that requires a direct contact of the towel fabric with skin.
As more attention is paid to the environmental protection nowadays, furs which are welcome by most ladies are banned due to pubic opinions. Therefore, the textile industry tries to find a substitute to meet the consumer's requirement, and such substitute method uses a counter wrap knitting method to knit a loop having a surface similar to that of a towel fabric, and then cuts the loop into independent yarns by a cutter, and thus the yarn so produced is very similar to the surface of the fur regardless of its appearance or touch. This method has been disclosed in R.O.C. Pat. Publication Nos. 208294 and 235625, and the counter wrap knitting used for knitting a fabric having yarn wools with an appearance similar to furs has an advantage that its yarn wool will not easily fall off. However, the counter wrap knitting method is not easy to achieve. On the other hand, the wrap knitting method is easy to achieve, but it has a problem that the yarn will fall off easily.
In summation to the description above, the fabric regardless of the loop of the towel fabric or the artificial fur woven by the wrap knitting method may be damaged easily because both are loop or independent yarn with its bottom not wrapped securely into the base fabric by the base yarn. If the fabric is made by a gluing method or a counter wrap knitting method, then the same issue as described above will exist.
Since the knitting technology cannot be broken through, therefore the length of the foregoing loop or yarn wool is limited (to approximately 3 mm). If a consumer (such as one who loves long furs) needs longer loops or longer yarn wools, then the present technology cannot meet the consumer's requirement. Finding a way of fixing the foregoing loop or yarn wool by a wrap knitting method and increasing the length of the loop and the yarn wool are an important subject for manufacturers in the related field to solve.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to overcome the foregoing shortcomings and avoid the existing deficiency by providing a yarn clamp assembly of a knitting machine to be installed to a circular knitting machine. The yarn clamp assembly comprises two knitting needles disposed between a plurality of transversal and separate entry needles for hooking and forming a base yarn at the bottom surface and a wool yarn additionally formed on a loop. When the two knitting needles weave the bottom surface, the base yarn forms two fixing loops coupled on the wool yarn, so as to enhance the fastening effect of the loop at the bottom surface.
Another objective of the present invention is to provide a fabric having a cut pile surface, so that the cut pile has a good fastening effect. An entry needle forming a loop includes a cutter for cutting the loop to produce yarn wool, and the yarn wool is fixed onto the bottom by fixing the loop by the foregoing yarn clamp assembly of the knitting machine.
A further objective of the present invention is to add the foregoing loop or yarn wool. The length of the base fabric is extended to increase the distance between the needle disc and the entry needle barrel of the knitting machine, so that the distance of the vertices of the base fabric and the loop is increased, and the length of the loop or yarn wool is increased.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and 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
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a schematic view of the appearance of the invention;
FIG. 2 is a schematic view of the actions of the invention;
FIG. 3 is a schematic side view of the invention;
FIG. 4 is schematic view of a preferred embodiment of the invention; and
FIG. 5 is a schematic enlarged view of a fixed loop of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 , 2 , 3 , and 5 respectively for the perspective view, the action, the lateral view and the enlarged view of fixing a loop according to the present invention, the yarn clamp assembly of a knitting machine knits a fabric having a loop on a side by a wrap knitting method and comprises a plurality of entry needles 20 transversally and separately disposed on the entry needle barrel or dial 2 , and the plurality of entry needles form a plurality of needling spaces among them, such that a needle cylinder or disc 1 disposed on the knitting machine comprises a plurality of knitting needles such as the first and second knitting needle 10 , 11 disposed in each of the needling space. Each knitting needle includes a yarn clamping section 101 , 111 for hooking the yarn back and forth. The yarn includes a wool yarn 3 formed on the loop surface and a base yarn 4 formed on the fabric base of the fabric. The wool yarn 3 is hooked by the first knitting needle 10 and the second knitting needle 11 on both sides of the entry needle 20 at a circular position of the wool yarn and coupled to the entry needle 20 to form the top of the loop 30 . The wool yarn 3 is further hooked at a circular position of a base yarn by the first knitting needle 10 and second knitting needle 11 in the needling spaces and hooked to the wool yarn 3 to hook the base yarn 4 and form two fixing loops B of the wool yarn 3 and the bottom of the loop 30 (as shown in FIG. 5 ).
Referring to FIGS. 2 and 5 for the detailed flow chart of the actions and the action of fixing the two fixing loops B to the base fabric, the needle disc 1 drives the plurality of first and second knitting needles 10 , 11 to move during the action, and the entry needle barrel 2 drives the plurality of entry needle 20 to move, so that the first and second knitting needles 10 , 11 repeat the hooking of yarns back and forth at the needling spaces of two adjacent entry needles 20 . In a weaving opening, two loops 30 can be formed, and two adjacent entry needles 20 and four adjacent knitting needles 10 , 11 of the two entry needles 20 are considered as a weaving opening. After two loops 30 are formed according to the aforementioned method, the wool yarn 3 hooked by the first knitting needle 10 and the second knitting needle 11 at the external weaving opening are woven into the base fabric with the full needle method by the base yarn 4 , and the wool yarn 3 hooked by the first knitting needle 10 and the second knitting needle 11 disposed at the internal side of the weaving opening is woven into the base yarn 4 to form two fixing loops B similarly by the full needle method, and the two fixing loops B have the effect of fixing the two loops 30 onto the base fabric.
Referring to FIG. 3 for the structure of the yarn clamp assembly of a knitting machine constituting a wrap weaving, and a latch 102 , 112 of the first and second knitting needles 10 , 11 is guided into the yarn clamping section 101 , 111 of the base yarn 4 , such that the base yarn 4 and the wool yarn 3 form a wrap knitting status of pressing the base yarn 4 onto the wool yarn 3 . The foregoing two fixing loops B improve the connecting strength of the loop 30 formed by the wrap knitting method with the base fabric. Therefore, the loop 30 is pulled by external forces and has a solid bottom structure to prevent the fabric structure from being damaged.
Referring to FIG. 4 for another preferred embodiment of the present invention, the foregoing yarn clamp assembly of the knitting machine can attach the bottom of the loop 30 to the base fabric of the fabric and will not be loosened easily, so that the yarn clamp assembly can be applied to the warp knitting method to weave fabric with cut piles 31 as shown in FIG. 4 , so that the bottom of the cut piles 31 produced by the wrap knitting method can be secured onto the fabric base of the fabric.
To form the cut piles 31 , a cutter 5 is installed at the lateral side of the entry needle 20 for cutting the top of the loop 30 , and the bottom of the loop 30 is connected securely by the two fixing loops B, and then the entry needle 20 continues its movement. The cutter 5 cuts the loop 30 situated at the top of the entry needle 20 to form the cut pile 31 . This method is used to produce the cut piles 31 of the fabric. Since the bottom of the cut pile 31 secures the two fixing loops B into the fabric base of the fabric, so that the connecting structure of the two will be increased greatly, and the fabric having cut piles 31 uneasy to fall is produced.
Refer to FIG. 4 for the schematic view of a further preferred embodiment of the present invention. To increase the length of the foregoing loop 30 or cut pile 31 to meet the requirements, the gap A between the needle disc 1 and the entry needle barrel 2 is increased, so that the distance between the second hooking yarn point and the entry needle 20 formed at the top of the loop 30 is increased, and the distance between the bottom of the loop 30 and the top of the loop 30 is increased correspondingly (as described above, the loop 30 is cut and processed by the cutter 5 to produce cut piles 31 ), and the loop 30 or cut pile 31 of approximately 15 mm long is produced.
While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. | A yarn clamp assembly of a knitting machine uses a wrap knitting method to knit a fabric having a side of a loop surface or a cut pile surface, and the base yarn of the base fabric forms two fixing loops fixed onto the wool yarn of the loop or the wool yarn during repeated knitting processes, so that the loop or the wool yarn will not be loosened easily from the base fabric due to the fixing effect of the two fixing loops. | 3 |
PRIORITY CLAIM
This patent application is a U.S. National Phase of International Patent Application No. PCT/EP2010/007091, filed 23 Nov. 2010, which claims priority to German Patent Application No. 10 2009 060 169.4, filed 23 Dec. 2009, the disclosures of which are incorporated herein by reference in their entirety.
FIELD
Embodiments of the present disclosure relate to a method for the automatic forward parking of a motor vehicle in a perpendicular parking space and to a corresponding driver assistance system.
BACKGROUND
In current parking assist systems or driver assistance systems for automatic parking, in which case parking both in the longitudinal parking spaces and in perpendicular parking spaces is carried out here, a parking space is measured using a suitable sensor system as the parking space is passed, and reverse parking is then carried out. With longitudinal parking spaces, this is the only possible way of parking in a longitudinal parking space since the rear axle generally cannot be steered. Longitudinal parking spaces in which forward parking is possible are so large, however, that it would be necessary to refer to a lane change, rather than parking.
Such a reverse parking operation into a parking space is described, for example, in DE 10 2009 006 336 A1. There, an automatic parking operation of a motor vehicle is monitored, in which case, before the actual parking operation, a parking space is measured using a camera-based method as the motor vehicle passes the parking space, and obstacles in the environment of the parking space are also determined. During the automatic parking operation, the camera-based method is still used to measure the environment of the motor vehicle, the obstacles newly detected in the measurement during the parking operation being compared with previously detected obstacles and a corresponding measure being carried out if there is a discrepancy between newly detected obstacles and known obstacles.
A method for automatically parking a motor vehicle in a parking space or for moving a motor vehicle out of a parking space can also be gathered from DE 10 2009 006 331 A1. In this case, the parking space is determined by an environment detection system of the motor vehicle and a target trajectory and a position end point relative to the parking space on the target trajectory are defined. A suitable steering angle is then calculated on the basis of the current vehicle position and this steering angle is used for parking or leaving a parking space.
The common feature of all of these known methods is that, after the parking space has been measured, a target trajectory is defined and is iteratively readjusted if necessary, along which trajectory the motor vehicle reverses into the parking space in one or more maneuvers.
The disadvantage of the reverse-parking strategies is that, on the one hand, the subsequent traffic is hindered during reverse-parking into a perpendicular parking space and there is also the risk of a subsequent vehicle taking the free parking space by means of forward parking and of forward parking usually being carried out both in parking garages and in garages.
SUMMARY
Therefore, the disclosed embodiments are based on specifying a method for the forward parking of a motor vehicle in a perpendicular parking space, including a garage.
This is achieved by means of a method without previous measurement of the parking space having the features of claim 1 , a method with previous measurement of the perpendicular parking space according to the features of claim 10 and a driver assistance apparatus for carrying out the methods having the features of claim 12 .
BRIEF DESCRIPTION OF THE FIGURES
The embodiments of the disclosure are described below using the drawings, in which:
FIG. 1 shows a forward parking operation according to a first disclosed embodiment,
FIGS. 2 a and 2 b show single-maneuver forward parking maneuvers,
FIG. 3 shows a diagrammatic illustration of multi-maneuver parking, and
FIG. 4 shows a diagrammatic illustration of a parking operation according to a second disclosed embodiment.
DETAILED DESCRIPTION
In a first disclosed embodiment, the method for the forward parking of a motor vehicle in a perpendicular parking space, the motor vehicle having environment sensors for determining environment data and obstacles in the environment of the motor vehicle, includes:
prealigning the motor vehicle in front of the perpendicular parking space in such a manner that a setpoint steering angle is between a maximum steering angle δ max and a minimum steering angle δ min , iteratively searching the permissible steering angle range between the maximum steering angle δ max and the minimum steering angle δ min for a current steering angle δ curr,i during a forward maneuvering movement of the motor vehicle into the perpendicular parking space, the current steering angle δ curr, i giving rise to a maximum free path length s i , i=0, . . . n, into the perpendicular parking space without the vehicle hitting obstacles, and terminating the forward maneuvering movement if the end of the parking operation has been reached or a reverse maneuvering movement must be carried out on account of an obstacle.
In this case, the maximum steering angle δ max and minimum steering angle δ min may be in the range ±17°.
Obstacles which have been found are optionally recorded, that is to say stored, in a map of the environment by the environment sensors. Obstacles which disappear again are likewise removed again from the map of the environment.
The first step i=0 of the iterative search may be carried out by scanning a predefined curvature range κveh;i=0 with a predefined curvature iteration size Δκ in order to determine an ideal curvature estimated value, and the forward maneuvering movement of the motor vehicle is carried out along the ideal curvature estimated value of the first step. In this case, the curvature estimated value of the first step corresponds to the maximum free path length si=0. Furthermore, the curvature estimated value determines the steering angle of the vehicle.
The predefined curvature range of the first step comprises the range of −0.15 to 0.15, the curvature iteration size Δκ of the first iteration step being 0.0005. In this case, the predefined curvature range of −0.15 to +0.15 corresponds to a minimum steering angle and a maximum steering angle of approximately ±17° for a wheel base of approximately 2 m.
For the second step and the subsequent steps i=1, 2, . . . , n of the iteration, the curvature estimated value of the previous step is used as the initial value for the current step, scanning being carried out around the initial value of the previous step with a current curvature iteration size to determine the current curvature estimated value of the i-th step, the current curvature iteration size being a function of the maximum path length si-1 of the previous step. Furthermore, the curvature range to be searched in the current step to determine the current curvature estimated value is a function of the curvature iteration size of the current step, and the forward maneuvering movement of the motor vehicle is carried out along the current curvature estimated value of the second step and the subsequent steps.
The curvature iteration size of the second step and the subsequent steps is optionally determined by means of the following formula:
Δ
κ
=
Δ
κ
0
(
min
(
s
i
-
1
,
σ
0
)
/
σ
0
)
2
(
1
)
In this case, s i-1 is the maximum distance determined in the previous step and σ 0 is an experimentally determined constant. In the present case, σ 0 =3 m has proved to be a reasonable value.
To determine the current curvature estimated value, the curvatures, that is to say the following curvature range, are optionally searched:
κ search,j =κ 0 +( j− 3)Δκ (2)
In this case, optionally j=0, 1, . . . m, where m is a natural number >0. Optionally, m=6, in other words the search range comprises seven values. Other values for m are naturally possible, as a result of which the search range becomes larger or smaller. Furthermore, K 0 is defined as the curvature of the previous step, that is to say
κ 0 =κ veh,i-1 (3)
Furthermore, it is possible to determine the vehicle alignment relative to the parking space by considering the detected lateral obstacles which are within a predefined distance value, a left-hand regression line and a right-hand regression line respectively being placed through the obstacle points defined by distances between the lateral, that is to say left-hand and right-hand, obstacles. The position and alignment of the vehicle relative to the perpendicular parking space can then be determined from the two regression lines by means of averaging and by considering the enclosed angle. In this case, the position and alignment during the forward maneuvering movement can likewise be taken into account. For the reverse maneuvering movement, the detection of the alignment of the vehicle in the parking space and, therefrom, the average distances from the vehicle to the left and the right is used to look for a favorable starting position for the subsequent forward maneuvering movement.
A second disclosed embodiment of the method for the forward parking of a motor vehicle in a perpendicular parking space involves the motor vehicle having environment sensors for determining environment data and obstacles in the environment of the motor vehicle, a perpendicular parking space being measured by the environment sensors as the motor vehicle passes the perpendicular parking space. A parking trajectory for the forward parking of the motor vehicle relative to the current location of the motor vehicle is then calculated, the motor vehicle being aligned by a reverse movement in such a manner that it can park in the perpendicular parking space with a subsequent forward movement. For the iterative forward parking of the motor vehicle in the perpendicular parking space, the vehicle can move along the calculated trajectory, the trajectory being able to be corrected again and again by means of current environment data. It is also possible for the forward movement of the motor vehicle to be effected by means of the above-described iterative method of the first embodiment.
As already mentioned, during the automatic parking operation, the environment sensors can still measure the environment of the vehicle, and the parking trajectory can thus be adapted to the new environment data.
A driver assistance system for the automatic parking of a motor vehicle and for carrying out the methods described above comprises environment sensors for determining environment data relating to the motor vehicle, a calculation unit for continuously calculating a parking trajectory from the environment data, and a controller which moves the motor vehicle. In this case, the controller comprises actuators for accelerating and decelerating the motor vehicle, actuators for a braking intervention and actuators for a steering intervention.
FIG. 1 shows a vehicle 1 which has a diagrammatically illustrated front axle 2 and rear axle 3 and is in front of a parking space 4 . In this case, a steering angle range 5 min and δmax is diagrammatically illustrated in FIG. 1 . The steering angle range between δmin and δmax is searched for steering angles which make it possible to travel as far as possible without hitting obstacles. Two possible curvatures, that is to say steering angles, 5 , 6 are illustrated in FIG. 1 , in which case it is clear that it is possible to travel further into the perpendicular parking space 4 with the curve 5 than with the curve 6 . The route which provides the greatest distance without hitting an obstacle, that is to say the curve 5 in the present case, predefines the steering angle, that is to say the curvature, which is then taken in the first step. As a note, it is remarked that travel straight ahead is carried out with the proposed iterative method in the absence of obstacles. Therefore, the method can be used not only in garages but also in confined driving situations.
At the start of the keying-in algorithm, the entire possible curvature range κi=0=−0.15 . . . 0.15 is scanned in curvature iteration sizes of Δκ=0.0005 to obtain a lower initial value for κi=0. This initial value and also all subsequent values always use the curvature determined last as a good estimation of the current iteration step to restrict the search space for the subsequent steps. This is because, in the subsequent steps, there is a restriction for reasons of the computation power of the search space and a search is carried out for new optimum curvatures only in the area surrounding the curvature determined last. to escape from local minima which are produced, in particular, when the vehicle approaches an obstacle, the curvature iteration size of each step is coupled to the free path length si-1 from the last step, that is to say
Δ κ = Δ κ 0 ( min ( s i - 1 , σ 0 ) / σ 0 ) 2 ( 1 )
where σ 0 =3 m is an experimentally determined constant and s i-1 is the maximum distance determined from the last step. The local minima, where a current minimum may also be a global minimum, can be recognized from the fact that the maximum distance becomes smaller and smaller. Therefore, the search range is then increased to possibly escape from a local minimum.
When searching for a new ideal curvature, the curvatures
κ search,j =κ 0 +( j− 3)Δκ (2)
around the curvature from the last step are checked, where j can assume the values j=0, . . . , 6 and K 0 is the curvature found in the preceding step, that is to say K 0 =K veh,i-1 .
With each of these path curvatures, an area on the roadway which is restricted by the vehicle boundaries is defined. Therefore, in the case of a left turn, the left rear corner and the front right corner form the area boundary and, in the case of a right turn, the front left corner and the rear right corner form the area boundary, as is also illustrated by the curves 5 , 6 in FIG. 1 .
There are now two possibilities of why a forward movement must be stopped. Either the vehicle has reached the end of the parking operation or the vehicle must carry out a reverse maneuvering movement to circumvent an obstacle.
FIG. 2 a and FIG. 2 b thus show two possible single-maneuver parking scenarios for different starting positions of the vehicle 1 in front of the parking space 4 . In other words, the driver approaches a favorable starting position for forward parking, that is to say he positions himself favorably in front of a garage, for example, and gives the driver assistance system the signal to carry out the parking operation using the iterative procedure.
However, during forward parking, the situation may occur in which the steering lock would mean a long collision-free route for the front of the vehicle but the side of the vehicle would collide with an obstacle, for example one of the corners of a garage. If this is the case, the vehicle must first reverse to achieve a favorable starting position.
This is illustrated in FIG. 3 in which the vehicle 1 would hit the left-hand edge (viewed in the direction of travel) of the perpendicular parking space in the fifth iteration step. Consequently, the vehicle carries out a reverse movement to avoid a collision with an obstacle. In other words, starting from an unfavorable starting position of the vehicle 1 in front of the perpendicular parking space 4 , the vehicle carries out a first forward movement 8 until the risk of a collision between a side of the vehicle 1 and a corner 7 of the perpendicular parking space 4 is imminent. To avoid the collision, the vehicle carries out a first reverse movement 9 to maneuver the vehicle 1 into a more favorable new starting position. For this purpose, the last position of the vehicle 1 in the parking space 4 along the first forward movement and its alignment can be taken into account to arrive at a more favorable new starting position. In other words, the longitudinal axis of the vehicle 1 must be brought closer to the longitudinal axis 11 of the perpendicular parking space 4 . The vehicle 1 then carries out a new second forward movement 10 into the parking space 4 .
The end of the forward parking operation is reached when either the end of the parking space is reached, in which case a parking space detection defines a destination, or when the driver forwards a corresponding signal to the vehicle. The realization of whether onward travel is blocked with an obstacle can be predefined by means of a minimum distance.
FIG. 4 finally shows a parking operation after previous measurement of the parking space. In this case, the vehicle 1 is driven past the parking space 4 and has measured the parking space 4 using suitable environment sensors. It was also signaled to the driver that the parking space is large enough. Starting from a starting position A, the driver assistance unit calculates a parking trajectory, a first reverse movement 12 changing the vehicle from the position A to an intermediate position B which is suitable for a forward parking operation. The vehicle 1 is changed to the position C in the parking space 4 with a subsequent forward movement 13 . Conventional trajectory planning systems can be used to plan the trajectory of the forward movement, the iterative forward parking method described above likewise being able to be used for the forward trajectory 13 .
LIST OF REFERENCE SYMBOLS
1 Vehicle
2 Front axle (steerable)
3 Rear axle
4 Parking space
5 Curve
6 Curve
7 Corner of the perpendicular parking space
8 First forward movement
9 First reverse movement
10 Second forward movement
11 Longitudinal axis of the parking space
12 Reverse movement
13 Forward movement
A Starting position
B Intermediate position
C End position | A method for forward parking a motor vehicle in a perpendicular parking space, wherein the motor vehicle has environment sensors for detecting environment data and obstacles in the environment of the motor vehicle, including pre-aligning the motor vehicle in front of the perpendicular parking space such that a target steering angle lies between a maximum steering angle δ max and a minimum steering angle δ min , iterative searching of the admissible steering angle range between the maximum steering angle δ max and the minimum steering angle δ min for a current steering angle δ akt , during a forward maneuver of the vehicle into the perpendicular parking space, wherein the current steering angle δ akt,i ensures a maximum free path length s i , i=01 . . . , n into the perpendicular parking space without the vehicle hitting obstacles, and terminating the forward maneuver if the end of the parking operation has been reached or a reversing maneuver has to be carried out owing to an obstacle. | 1 |
This application is a continuation of application Ser. No. 08/281,395, filed Jul. 27, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a diagnosing apparatus which is used in a vehicle control system wherein signals are supplied from sensors to a microcomputer to control the driving of actuators, and which diagnoses malfunction of the control system using the microcomputer.
2. Description of the Related Art
There is known a diagnosing apparatus which performs self-diagnosis according to previously installed programs while a vehicle is running under normal conditions, and turns on an alarm lamp when detecting the malfunction to indicate where the malfunction takes place. The diagnosis of this apparatus, however, may not be completely reliable. When a vehicle is driven in various modes (driving conditions), this apparatus may not properly diagnose the occurrence of a malfunction even if it has occurred, or may erroneously diagnose the occurrence of a malfunction even if it has not occurred. When vehicles are diagnosed by qualified people, e.g., dealers, repairers, etc., the vehicles are driven in a predetermined mode to prevent erroneous diagnosis, or even the same diagnosing items may be checked by different methods to improve the precision of self-diagnosis. In other words, the self-diagnosis is carried out in repair shops in accordance with a special program newly prepared for this purpose.
The technique that relates to an apparatus which executes self-diagnosis in accordance with such two types of programs is disclosed in, for example, Japanese Unexamined Patent Publication No. 62-188933. This scheme uses a first program which is run in normal mode (first mode) and a second program which is run in check mode (second mode) at a higher detection precision than the first program. When a user drives a vehicle, the normal mode is selected and self-diagnosis is executed in accordance with the first program. At the time a vehicle is inspected or is repaired in a repair shop, the check mode is selected and self-diagnosis is executed in accordance with the second program.
The mode selection is performed based on the status of a test switch (test terminal) provided in the vehicle or the engine room and the status of the ignition switch. For example, the check mode (second mode) is selected in a repair shop when the ignition switch is set on and the test switch is closed, and the normal mode (first mode) is selected otherwise.
If a vehicle is returned to the user without releasing the check mode (first mode), i.e., without setting the test switch off after diagnosis in the repair shop is completed, the following problem arises. Even when a slight malfunction occurs while the user is driving the vehicle under the normal conditions, i.e., even when an instantaneous malfunction which hardly affects the driving occurs, such an event is diagnosed as a malfunction and the alarm lamp is lit. This is likely to make the user overanxious.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide a diagnosing apparatus for a vehicle control system, which has high reliability. In connection with this object, even when an instantaneous malfunction that hardly affects the driving occurs while the user is driving the vehicle under the normal conditions, such an event is prevented from being diagnosed as a malfunction, so that a user does not become overanxious.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, an improvement of a diagnosing apparatus is proposed. The apparatus is used in a control system for a vehicle for controlling actuators based on signals from sensors transferred to a microcomputer to diagnose a malfunction of said control system by means of said microcomputer, wherein said microcomputer operates in a selected operation mode from a group consisting of a first mode and a second mode, said second mode being used for the diagnosis requiring a higher precision than the diagnosis according to the first mode. The apparatus comprises memory means for storing a first program for detecting the malfunction of said control system and a second program having a higher detection precision than said first program, and selecting means for selecting the operation mode of the microcomputer in accordance with an extent of the malfunction of the control system. The apparatus further includes executing means for executing the diagnosis according to the first program when the selecting means selects the first mode, and executing diagnosis according to the second program when the selecting means switches the operation mode from the first mode to the second mode, and setting means for setting a condition of said control system to return the operation mode of the microcomputer to the first mode from the second mode. The apparatus also has detecting means for detecting a status of said control system when the diagnosis is performed in the second mode, and return means for forcibly returning said diagnosis mode to the first mode from the second mode when the status detected by the detecting means matches with the conditions set by the setting means when the second mode is carried out.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a diagram schematically illustrating the structure of a self-diagnosing apparatus for a vehicle control apparatus according to one embodiment of the present invention;
FIG. 2 is a block diagram showing the electric structure of an electronic control unit (ECU) in FIG. 1;
FIG. 3 is a flow chart illustrating a "self-diagnosis routine" that is executed by the ECU in FIG. 2; and FIG. 4 is a block diagram showing a part of the electric structure of an ECU according to another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A self-diagnosing apparatus for a vehicle control apparatus according to one embodiment of the present invention will be described in detail with reference to FIGS. 1 through 3.
As shown in FIG. 1, a V shape engine 1 is mounted in a vehicle. The engine 1 has a crankshaft 19 extending perpendicular to the surface of the sheet of the drawing, and is separated in a V shape with the crankshaft 19 at the center, forming a pair of banks 2 and 3. Each of the banks 2 and 3 is provided with a plurality of cylinders arranged along the crankshaft 19. Intake manifolds 4L and 4R and exhaust manifolds 5L and 5R are connected to the banks 2 and 3, respectively.
The intake manifolds 4L and 4R are connected to a common surge tank 6 and a common air-intake pipe 7, with an air cleaner 8 provided at the inlet port of the air-intake pipe 7. Those intake manifolds 4L and 4R, the surge tank 6 and the air-intake pipe 7 constitute an air-intake passage. Air around the engine 1 is taken into the air-intake passage from the air cleaner 8, and is guided through the air-intake pipe 7 and surge tank 6 to the individual intake manifolds 4L and 4R. The guided air is led into combustion chambers 2a and 3a in the individual cylinders when the air-intake passage is opened by intake valves 9L and 9R.
A throttle valve 10 is rotatably attached to the air-intake pipe 7. The throttle valve 10 is coupled via a cable, etc., to an accelerator pedal, and rotates in responsive to the manipulation of the accelerator pedal by a driver. This rotation of the throttle valve 10 adjusts the air passing area of the air-intake passage, thereby controlling the amount of air (intake air amount Q), supplied to each combustion chamber 2a or 3a.
Fuel injectors 11L and 11R for injecting fuel in the combustion chambers 2a and 3a in the associated cylinders are attached to the intake manifolds 4L and 4R. Ignition plugs 12L and 12R are attached to the respective banks 2 and 3 in association with the respective cylinders. Each of the injectors 11L and 11R has a solenoid coil and a needle valve which functions when a current flows across the solenoid coil. When the needle valve functions, fuel fed under pressure from a fuel tank by a fuel pump (not shown) is injected toward the intake manifold 4L or 4R from each injector 11L or 11R. The injected fuel is mixed with air and this air-fuel mixture is supplied to each combustion chamber 2a or 3a. In the combustion chambers 2a and 3a, the supplied air-fuel mixtures are exploded and burned by the ignition plugs 12L and 12R, respectively.
The exhaust manifolds 5L and 5R constitute an exhaust passage. The gases produced in the combustion chambers 2a and 3a are led out to the exhaust manifolds 5L and 5R when the exhaust passage is opened by exhaust valves 13L and 13R. Three way catalytic converters 14L and 14R are respectively connected to the exhaust manifolds 5L and 5R. Each of the catalytic converters 14L and 14R oxidizes hydrocarbon (HC) and carbon monoxide (CO) in the exhaust gas and reduces nitrogen oxide (NOx) to thereby purge the exhaust gas. Exhaust pipes 15L and 15R are respectively connected to the catalytic converters 14L and 14R, and the downstream ends of the exhaust pipes 15L and 15R are combined to constitute a single exhaust pipe 16.
High voltages distributed by separate distributors 17L and 17R are applied to the associated ignition plugs 12L and 12R of the respective banks 2 and 3. The distributors 17L and 17R distribute high voltages, output from separate igniters 18L and 18R, to the ignition plugs 12L and 12R in synchronism with the rotation of a crankshaft 19. The ignition timings for the ignition plugs 12L and 12R are determined by the timings at which the high voltages are output from the igniters 18L and 18R.
The engine 1 is provided with an engine speed sensor 31 which detects the rotational speed of the crankshaft 19 (engine speed NE). The banks 2 and 3 are respectively provided with first and second cylinder sensors 32 and 33. Those sensors 32 and 33 detect the reference positions of individual cam shafts 20L and 20R which rotate in responsive to the crankshaft 19. Detection signals from both sensors 32 and 33 are used to discriminate the cylinders and to detect the positions of the valves 9L, 9R, 13L and 13R.
An air flow meter 34, which detects the intake air amount Q, is attached to the downstream side of the air cleaner 8. Provided in the vicinity of the air flow meter 34 is an inlet air temperature sensor 35 which detects the temperature of air (intake air temperature THA), led into the air-intake pipe 7. Provided in the vicinity of the throttle valve 10 is a throttle sensor 36 which detects the angle of the throttle valve 10 (throttle angle TA). A coolant temperature sensor 37 is attached to the engine 1 to detect the temperature of the coolant (coolant temperature THW).
A pair of air-fuel ratio sensors 38 and 39 are respectively provided at the upstream and downstream of the catalytic converter 14L in the exhaust passage. Likewise, another pair of air-fuel ratio sensors 40 and 41 are respectively provided at the upstream and downstream of the other catalytic converter 14R. Those sensors 38 to 41 each sense the density of oxygen (oxygen density Ox) remaining in the exhaust gas in order to detect the ratio of air to fuel (air-fuel ratio) in the mixtures supplied to the combustion chambers 2a and 3a. Those sensors 38 to 41 include sensor elements which have different temperature-dependent characteristics. To prevent the characteristics of the sensor elements from affected by the temperature, the air-fuel ratio sensors 38-41 are respective provided with heaters 38a, 39a, 40a and 41a, which generate heat to heat up the respective sensor elements when supplied with currents.
A transmission 21 coupled to the engine 1 is provided with a vehicle speed sensor 42 which detects the speed of the vehicle (vehicle speed SPD).
A bypass passage 22, which bypasses the throttle valve 10, connects the air-intake pipe 7 to the surge tank 6. Disposed in this passage 22 is an idle speed control valve (ISCV) 23. The ISCV 23 adjusts the intake air amount Q to allow the engine speed NE to converge to a predetermined value at the idling time of the engine 1 at which the air-intake passage is closed by the throttle valve 10. The ISCV 23 employed in this embodiment is of a type in which, when energized, the magnetic force of the coil changes to reciprocate the shaft, thereby adjusting the air flow area of the air-intake passage.
In this embodiment, an alarm lamp 24 is provided on an instrument panel (not shown) at the driver's seat. One lead line of this lamp 24 is connected to the positive terminal of a battery 25. When a malfunction occurs in any of the sensors 31 to 33 and 35 to 42 and the air flow meter 34, the alarm lamp 24 is lit to inform the driver of that malfunction.
The vehicle according to this embodiment has a self-diagnosis function which detects a malfunction in individual sections and stores and displays such a malfunction. For this diagnosis, an external diagnosing unit 27 is provided separately from the vehicle. This diagnosing unit 27 is equipped with various switches and a display for displaying the results of the diagnosis. The diagnosing unit 27 is generally placed in a repair shop and is connected to the vehicle via a connector 28 by a service engineer at the time the vehicle is inspected or repaired.
The aforementioned various sensors 31 to 33 and 35 to 42 and the air flow meter 34 are connected to an electronic control unit (ECU) 51. Also connected to this ECU 51 are the injectors 11L and 11R, the igniters 18L and 18R, the ISCV 23, the alarm lamp 24 and the heaters 38a to 41a. The battery 25 is connected via an ignition switch 45 to the ECU 51, so that when this switch 45 is set on, the voltage of the battery 25 (battery voltage) is applied to the ECU 51.
Based on the signals from the individual sensors 31 to 33 and 35 to 42 and the air flow meter 34, the ECU 51 performs various computations and make decisions to control the injectors 11L and 11R, the igniters 18L and 18R, the ISCV 23, the alarm lamp 24 and the heaters 38a to 41a.
As shown in FIG. 2, the ECU 51 includes a central processing unit (CPU) 52, a read only memory (ROM) 53, a random access memory (RAM) 54, and a backup RAM 55 for saving previously-stored data. The CPU 52 executes various computations in accordance with previously installed control programs. Predetermined control programs and initial data that are necessary for the CPU 52 to execute computations are previously stored in the ROM 53. The RAM 54 temporarily stores the results of operations executed by the CPU 52. The backup RAM 55 is backed up by the battery 25 to hold various types of data in the RAM 54 even after power supply to the ECU 51 is stopped. Those individual components 52 to 55, an analog/digital (A/D) converter 56, a buffer-equipped input/output (I/O) unit 57 and a controller 59 for serial communication are mutually connected by a bus 58.
The aforementioned air flow meter 34, the inlet air temperature sensor 35, the coolant temperature sensor 37, and the air-fuel ratio sensors 38 to 41 are connected to the A/D converter 56. The battery 25 is also connected to the A/D converter 56 via the ignition switch 45. The diagnosing unit 27 is detachably connected via the connector 28 to the controller 59. The engine speed sensor 31, the cylinder sensors 32 and 33, the throttle sensor 36 and the vehicle speed sensor 42 are connected to the I/O unit 57. Also connected to the I/O unit 57 are the ISCV 23, the injectors 11L and 11R, the igniters 18L and 18R and the alarm lamp 24. The heaters 38a-41a are also connected to the I/O unit 57 via a driver 60.
The CPU 52 reads detection signals from the sensors 31 to 33 and 35 to 42 and the air flow meter 34 via the A/D converter 56 and I/O unit 57. The CPU 52 reads data, sent from the diagnosing unit 27, via the controller 59. Based on the read signals, the CPU 52 controls the driving of the injectors 11L and 11R, the igniters 18L and 18R and the alarm lamp 24 via the I/O unit 57. Likewise, the CPU52 controls the heaters 38a to 41a via the I/O unit 57 and the driver 60, based on the read signals.
The diagnosis function will now be described. Two kinds of self-diagnosis programs are previously stored in the ROM 53. One of the programs is a first program which is run in normal mode (first mode) and the other program is a second program which is run in check mode (second mode) at a higher detection precision than the first program.
When the user is driving the vehicle under the normal conditions, the diagnosing unit 27 is not connected via the connector 28 to the ECU 51. In this case, the normal mode is basically selected and self-diagnosis is executed in accordance with the first program.
When severer diagnosis is required, the diagnosing unit 27 is connected via the connector 28 to the ECU 51 by a dealer, in a repair shop, etc., and a service engineer performs predetermined manipulations on the various switches of the diagnosing unit 27. Then, the diagnosing unit 27 sends various types of data to the ECU 51 via the controller 59. The check mode is selected based on the data, and self-diagnosis is carried out in accordance with the second program.
The various types of data includes, for example, data about a command to switch the normal mode to the check mode (mode switching command) and data about a return pattern that is used to automatically return to the normal mode from the check mode. In this embodiment, when the ignition switch 45 has been turned on or off by a predetermined number of times (e.g., five times) or more, it is considered to be the return mode. Specifically, when the switch 45 has been turned on or off by a predetermined number of times, it is considered that self-diagnosis in check mode is no longer performed. If this conditions is met, therefore, there should be no problem to switch to the normal mode from the check mode.
When the ignition switch 45 is set on and the battery voltage is applied to the ECU 51, the ECU 51 executes an initial routine to initialize various types of data. In this routine, the ECU 51 counts the number of the ON/OFF actions of the switch 45 and stores the count value in the backup RAM 55. When the count value is incremented by "1" and reaches a predetermined value, the ECU 51 clears the count value.
A description will now be given of the operation and advantages of the thus constituted embodiment. The flow chart in FIG. 3 illustrates a "self-diagnosis routine", one of processes executed by the ECU 51. The individual processes in this self-diagnosis routine are executed every predetermined time based on a check mode flag CMF. The flag CMF is set to "1" when the check mode is selected as the self-diagnosis mode and is set to "0" when the normal mode is selected.
In step 101, the ECU 51 determines whether or not data is transmitted from the diagnosing unit 27. That is, the ECU 51 determines if the diagnosing unit 27 is connected via the connector 28 to the ECU 51 and data is transmitted from the diagnosing unit 27 in accordance with the manipulation of various switches of the diagnosing unit 27. If there is no data transmission from the diagnosing unit 27, the ECU 51 temporarily terminates the subsequent processing. If data is transmitted from the diagnosing unit 27, on the other hand, the ECU 51 proceeds to step 102.
In step 102, the ECU 51 determines if the flag CMF is "1". If the flag CMF is not "1", the ECU 51 determines that the normal mode is currently selected and self-diagnosis is executed in accordance with the first program, and proceeds to step 103.
In step 103, the ECU 51 determines based on the data sent from the diagnosing unit 27 whether or not there is a command to switch to the check mode. In other words, the ECU 51 determines if a service engineer has performed a predetermined manipulation on the switches of the diagnosing unit 27 in order to switch the normal mode to the check mode. If there is no mode switching command, the ECU 51 determines that the service engineer has not manipulated any switch of the diagnosing unit 27 and the normal mode is still effective, and moves to step 104. In step 104, the ECU 51 executes self-diagnosis in accordance with the first program associated with the normal mode, and then temporarily terminates the subsequent processing. In the next and subsequent control periods, therefore, self-diagnosis according to the first program continues unless a command to switch to the check mode is issued.
If the command to switch to the check mode has been issued in step 103, the ECU 51 receives a return pattern in step 105, and sets this pattern and stores it in the backup RAM 55 in step 106. That is, like in the above-described case of the mode switching command, the ECU 51 reads and sets the return pattern input by a predetermined manipulation on the diagnosing unit 27. In this case, the ECU 51 sets the event that the ignition switch 45 has been turned on or off "five times" or more, as the condition to return to the normal mode (return pattern).
In step 107, the ECU 51 sets the flag CMF back to "1" from "0" to switch the normal mode to the check mode and temporarily terminates the subsequent processing.
In the next control period, the ECU 51 determines that the decision condition in step 102 is satisfied, and executes self-diagnosis according to the second program associated with the check mode in step 108.
Then, the ECU 51 analyzes the actual running pattern of the vehicle in step 109. In this embodiment, the ECU 51 analyzes the number of the ON/OFF actions of the ignition switch 45, for example.
In the next step 110, the ECU 51 compares the running pattern, analyzed in step 109, with the return pattern, set in step 106, to determine if both patterns match with each other. In this case, the ECU 51 determines if the number of the ON/OFF actions of the ignition switch 45 is equal to or greater than "5". If the running pattern does not match with the return pattern, the ECU 51 determines that self-diagnosis according to the second program should continue, and temporarily terminates the subsequent processing. If both patterns match with each other, the ECU 51 determines that self-diagnosis according to the second program is no longer necessary and self-diagnosis should be executed according to the first program. In this case, the ECU 51 switches the flag CMF to "0" from "1" in step 111, and temporarily terminates the subsequent processing.
According to this embodiment, as described above, the return pattern is set when the self-diagnosis mode is switched to the check mode from the normal mode. When self-diagnosis according to the second program associated with the check mode is completed and the return pattern matches with the running pattern (when the ignition switch 45 has been turned on or off "five times" or more), the diagnosis mode is automatically switched to the normal mode from the check mode.
Even if the vehicle is returned to the user without setting the self-diagnosis mode back to the normal mode from the check mode after the high-precision self-diagnosis is executed according to the second program by a qualified person in a repair shop, the problem inherent to the prior art is overcome. More specifically, if the running pattern matches with the return pattern when the user tries to drive the vehicle, the self-diagnosis mode is automatically returned to the normal mode from the check mode even though no mode returning work has been done. While the user is driving the vehicle, therefore, self-diagnosis is executed mostly in accordance with the first program associated with the normal mode. Even if a slight malfunction occurs or an instantaneous malfunction that hardly affects the driving occurs, such an event can be prevented from being diagnosed as a malfunction. Accordingly, the alarm lamp 24 is not lit, so that a user does not become overanxious.
Although only one embodiment of the present invention has been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that this invention may be worked out in the following manners.
(1) Although the return pattern is set by the manipulation of the diagnosing unit 27 in the above-described embodiment, the return pattern may be set in the following manner.
As shown in FIG. 4, a connector 64 is connected via three input terminals 61, 62 and 63 to an I/O unit 57 of the ECU 51. The connector 64 has a plurality of external terminals 65, 66, 67 and 68 (four in FIG. 4), one (external terminal 65) of which is grounded.
At the time self-diagnosis is carried out in accordance with the second program, two or more of the external terminals 66 to 68 are short-circuited. In accordance with the combination of the external terminals 66-68 concerning this short-circuiting, one of plural types of signals is input to the I/O unit 57.
Stored in the ROM 53 are plural types of return patterns according to those input signals. The return patterns may reflect the number of the ON/OFF actions of the ignition switch 45 being equal to or greater than a predetermined number (e.g., "five times") and the vehicle speed SPD is equal to or greater than a predetermined value (e.g., "90 km/h").
The return pattern which is associated with the input signal is selected. In this way, the return pattern can be set without depending on the manipulation of the diagnosing unit 27.
(2) As a return-pattern setting method similar to the one explained in the above modification (1), only a single external terminal 66 may be used. That is, the proper return pattern may be selected in accordance with the number of times the external terminal 66 has been set on or off by a dealer per predetermined time (e.g., "1 second"). The return pattern can also be set in such manner.
(3) Although one example of the return pattern reflects the number of the ON/OFF actions of the ignition switch 45 being "5" or more in the above-described embodiment, the following return patterns are also possible.
(a) The vehicle speed SPD is equal to or greater than a predetermined value as mentioned in the case (1).
(b) The vehicle is running over a predetermined time or longer.
(c) The engine 1 is running over a predetermined time or longer.
(d) The number of the ON/OFF actions of the ignition switch 45 is equal to or greater than a value other than "5".
(e) The engine 1 has been activated a predetermined number of times or more.
(f) The 10 mode running (running pattern for measuring the exhaust gas, which has been employed since the regulation restriction in 1973) is completed.
(g) Premise conditions necessary for diagnosing specific components (e.g., the premise conditions necessary for diagnosing the air flow meter 34 are that the engine speed NE is equal to or above a predetermined value and the state in which the coolant temperature THW is equal to or higher than a predetermined level continues for a predetermined timer or longer) are satisfied.
(h) Running necessary for all the components, not just a part thereof, is conducted.
The return pattern is not limited to those mentioned above, but may be the statuses detectable by various sensors 31 to 33 and 35 to 42 and the air flow meter 34 or combinations of those statuses.
(4) Although the return pattern is set when the self-diagnosis mode is switched to the check mode from the normal mode in the above-described embodiment, the timing for setting the return pattern is not specifically limited. It is therefore possible to set the return pattern in advance at the time each vehicle is manufactured.
Therefore, the present examples and embodiment are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | A diagnosing apparatus for use in a vehicle is disclosed. A microcomputer operates according to either a first mode or a second mode. The second mode being used for the diagnosis requiring a higher precision than the diagnosis according to the first mode. A first program for detecting the malfunction of a control system and a second program having a higher detection precision than the first program is stored in a memory. The operation mode of the microcomputer is selected in accordance with an extent of the malfunction. The diagnosis according to the first program and the second program are executed when the first mode and the second mode are selected, respectively. An operation status of the control system is detected by sensors the diagnosis is performed in the second mode. The diagnosis mode is forcibly returned to the first mode from the second mode when the status detected by the detecting means matches with a predetermined conditions. | 1 |
FIELD AND BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of industrial power generation and circulating fluidized bed (CFB) reactors and combustors having impact-type particle separators, and, in particular to a new and useful impact-type particle separator for a CFB.
2. Description of the Related Art
In CFB reactors or combustors, reacting and non-reacting solids are entrained within a reactor enclosure by an upward gas flow which carries the solids to an exit at an upper portion of the reactor enclosure. There, the solids are typically collected by an impact type primary particle separator, and returned to a bottom portion of the reactor enclosure either directly or through one or more conduits. The impact-type primary particle separator at the reactor enclosure exit typically collects from 90% to 97% of the circulating solids. If required by the process, an additional solids collector may be installed downstream of the impact-type primary particle separator to collect additional solids for eventual return to the reactor enclosure.
As disclosed in U.S. Pat. No. 5,343,830, the use of impact-type particle separators in CFB reactors or combustors is well known. To the extent necessary to describe the general operation of CFB reactors and combustors, the reader is referred to U.S. Pat. No. 5,343,830, the text of which is hereby incorporated by reference as though fully set forth herein. In one of the earliest CFB designs, an external, impact-type primary particle separator having a plurality of impingement members arranged in staggered rows was used in combination with a non-mechanical L-valve and a secondary (multiclone) particle separator. The rows of staggered impingement members discharged all of their collected solids into a storage hopper located underneath them, and these collected solids were returned to the bottom portion of the reactor enclosure via the L-valve.
Later CFB designs employed additional rows of staggered impingement members which were positioned upstream (with respect to a direction of flue gas and solids flow through the apparatus) of the impingement members associated with the storage hopper and its L-valve. As disclosed in U.S. Pat. No. 4,992,085, the text of which is hereby incorporated by reference as though fully set forth herein, a plurality of such impingement members are located within an upper portion of the reactor enclosure, arranged in at least two staggered rows. The impingement members hang and extend vertically across a width of the reactor exit, with collected solids falling unobstructed and unchanneled underneath these collecting impingement members along a rear enclosure wall of the CFB reactor or combustor. An important element of these “in-furnace” collecting impingement members, or “in-furnace U-beams” as they are generally referred to, is a baffle plate near a lower end of these impingement members which enhances their collection efficiency.
As disclosed in the aforementioned U.S. Pat. No. 5,343,830, CFB reactors or combustors are known wherein the two or more rows of impingement members located within the furnace or reactor enclosure are followed by a second array of staggered impingement members which further separate particles from the gas stream, and return them via cavity means and particle return means without external and internal recycle conduits.
U.S. Pat. No. 6,095,095 teaches a further improvement in impact-type solids separators for a CFB which is a simpler and lower cost impact-type primary particle separator. Instead of providing a cavity means or hopper with discharge openings underneath the collector elements making up the impact-type primary particle separator, the separator of U.S. Pat. No. 6,095,095 has a simple floor for internal return of all primary collected solids to a bottom portion of the reactor or combustor for subsequent recirculation.
U.S. Pat. No. 6,095,095 does not address the mechanical aspects of the individual separator elements, however, including relative thermal expansion between the elements (or U-beams) and the enclosure walls. As noted above, a hopper is not used in the separator of U.S. Pat. No. 6,095,095.
It is often desirable to utilize collection elements like U-beams made of stainless steel and hung from the roof of the CFB reactor while operating in a floored impact collector mode. However, when a solid floor is located beneath the collector elements, the U-beams may expand onto a pile of solids as a result of thermal expansion of the U-beam metals. When the collection elements touch the solids piles, a high compressive force is exerted on the long dimension of the U-beams. Thus, because of the large thermal expansion in the length of the U-beams which can be expected with stainless steel U-beams and the need to avoid placing large compressive forces on the U-beams, a gap must be available between the lower ends of the U-beams and enclosure floor so that the collection elements can freely expand.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an impact-type separator for a CFB which accounts for thermal expansion of the separator elements.
A further object of the invention is to provide an arrangement of collection elements having gaps for free thermal expansion of the elements within the enclosure in a floored collection element environment.
Accordingly, a collection element arrangement is provided having attachments near their lowermost ends which simulate a continuous sloping surface, or floor. The sleeve attachments' upper surfaces, forming the floor, permit collected solids to flow down the sloping surface back into the furnace or reactor chamber. The sleeve attachments are fitted around each element. The outer wall of each attachment is positioned to leave a small gap between the adjacent sleeve and/or CFB enclosure walls. The upper surface of the sleeve attachments block off the lower ends of the collection elements as well. The attachments are integrally connected with the collection elements, so that they expand together through increasing temperatures in the CFB during operation startup.
In an alternative embodiment, the CFB may include a staggered array of heat exchange tubes for solids collected by the collection elements to pass through prior to returning to the reactor chamber.
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 a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a sectional side elevation of a CFB having collection elements according to the invention;
FIG. 2 is a sectional side elevation of an alternate embodiment of the collection elements of the invention;
FIG. 3 is a top plan view of the tube and collection element arrangement of FIG. 2 taken along line 3 — 3 ; and
FIG. 4 is a perspective view of the upper end of one of the attachments for the collection elements of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows a CFB furnace or reactor chamber 100 having an adjacent collection chamber 80 and a passage 85 between them for returning solids to the furnace or reactor chamber 100 . The upper end of the furnace chamber 100 is connected to a flue 105 for hot gases and entrained solids 60 to exit the system.
Two sets of impact-type solids separators are provided in the flue 105 . A first set of collection elements are provided on the furnace chamber 100 side of chamber wall 90 and are known as internal collector elements 22 . A second set of collection elements 20 are positioned in the flue 105 between the chamber wall 90 and collection chamber wall 92 , over the collection hopper 80 . The second set of collection elements are external collection elements 20 .
Each set of collection elements 20 , 22 are preferably U-beams, as known in the art, oriented to face the furnace chamber 100 . Each collection element 20 , 22 has a sleeve attachment 30 around its lower end which encloses the U-beam channel. A sloped floor 35 is formed by the upper surfaces 33 of sleeve attachments 30 around the vertical surfaces of collection elements 20 , 22 . The floor 35 is sloped at an angle with respect to the horizontal to cause solids particles 60 falling thereon to be returned to the chamber 100 . The sleeve attachments 30 are integral with the collection element 20 , 22 to which they are connected. Small gaps 37 are provided between adjacent sleeve attachments 30 so that the sleeves 30 and collection elements 20 , 22 may expand together with Increased temperatures in the reactor enclosure.
Thus, the floor 35 is effectively floating, supported from above by the collection elements 20 , 22 . In an alternative embodiment, the sleeve attachments 30 may actually “float” on the U-beams 20 , so that if the siftings 70 pile in the hopper 80 grows too large, the sleeve attachments 30 simply ride up the U-beams 20 , raising the floor 35 slightly.
Entrained solids in the gases 65 impact the collection elements 20 , 22 . Solids hitting the collection elements 20 , 22 fall downwardly within the U-beam collection elements 20 , 22 and onto the floor 35 formed by the sleeve attachments 30 . The solids then slide down the sloped floor 35 and return to the furnace chamber 100 under force of gravity.
Other solids 60 which fall out of the entrained solids and gases 65 may be sufficiently small that they pass through gaps 37 between adjacent sleeve attachments 30 into collection hopper 80 as “siftings” 70 . The siftings 70 are returned to the furnace chamber 100 via passage 85 . The gaps 37 are provided to ensure free vertical movement of the collection elements 20 , 22 and sleeve attachments 30 and allow for horizontal expansion of the elements 20 , 22 and attachments 30 as well.
In use, the sleeve attachments 30 expand up and down a few inches with the U-beam collection elements 20 , 22 as the temperature varies during start up and full operation. Preferably, the sleeve attachments 30 and U-beams are both made of stainless steel, although other materials used for impact-type separators can be substituted as well. A benefit of the invention is that stainless steel collection elements 20 , 22 can be used, while providing the effect of a floored impact-type separator, such as described in U.S. Pat. No. 6,095,095. Stainless steel is most preferred as a material because of its reliability when used in impact-type separators. The sloping floor 35 formed by the sleeve attachments 30 permits the use of stainless steel because it accommodates the relatively large coefficient of thermal expansion of the steel which creates large differential thermal expansion with other components of the CFB reactor, while giving the benefit of a floored separator.
In a preferred embodiment, each sleeve attachment 30 is formed integral with the U-beam 20 , 22 to which it is connected for mechanical integrity and support.
In a further embodiment, the height of the individual sleeve attachments 30 may be different between rows, so that the horizontal thrust force from the flowing gases and solids 65 entering the external collection element array is carried back to the enclosure wall behind the array.
FIGS. 2 and 3 illustrate a different CFB reactor arrangement using the suspended floor 35 of the invention with collection elements 20 , 22 . In the alternative arrangement, a series of water tubes 110 arranged in a staggered array 115 in the flow path of the downward flowing solids 60 . The water tubes 110 extend partly into the flow path of the gases and entrained solids 65 as well. The water tubes 110 are preferably extensions of the furnace chamber wall 90 .
The same variations discussed above for the sleeve attachments 30 and collection elements 20 , 22 may be applied to the embodiment shown in FIGS. 2 and 3.
FIG. 4 illustrates a sleeve attachment 30 for use with the invention. The opening 40 is fitted around a collection element 20 , 22 and connected to the lower end to form the floor 35 with the sleeve attachment upper surfaces 33 .
While a specific embodiment of the invention has 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. | A collection element arrangement is provided having sleeve attachments near their lowermost ends which simulate a continuous sloping surface, or floor. The sleeve attachments upper surfaces forming the floor permit collected solids to flow down the sloping surface back into the furnace or reactor chamber. Stainless steel can be used for the collection elements and sleeve attachments since the floating floor accommodates differential thermal expansion between CFB components. | 5 |
FIELD OF THE INVENTION
The present invention relates to the field of textile technology and concerns a method and an apparatus for continuous crimping of threads made from a thermoplastic material.
BACKGROUND AND SUMMARY OF THE INVENTION
For continuous crimping of threads (bundles of fibrils) of thermoplastic material these threads are conveyed through a duct e.g. by means of a hot transporting medium flowing under pressure in which process the threads are heated and then are transferred into a stuffer box designed in such a manner that the pressure of the transporting medium is released as the transporting medium escapes from the nozzle outlet opening. In the stuffer box the thread hits against a plug formed by thread that already had left the opening, in which process it is crimped. The plug is transported further at a speed lower than the thread speed in the conveyer duct, subsequently is cooled down and opened up to yield the texturized yarn.
The stuffer box in which the plug is formed can be limited by stationary perforated walls, formed e.g. by slats, which longitudinally surround the plug along its length. The plug is pushed by the pressure of the transporting medium to overcome the friction forces on the stuffer box walls throughout the stuffer box which it leaves via a plug opening arranged opposite the outlet opening which can be provided with a pair of delivery rolls which expels the plug in a controlled manner.
The stuffer box also can be limited partially only by stationary walls, and partially by walls which move at plug movement speed. A method and an apparatus for continuous crimping of thermoplastic threads using a stuffer box provided with walls, part of which move with the plug, are described e.g. in the European Patent Nr. 310890 applied for by the same applicant. The apparatus described comprises a texturing nozzle with a conveyer duct, an outlet opening and two shaped extension members extending therefrom in the direction of thread transport. For transporting the plug formed between the shaped extension members a duct formed by lateral guide means and extending along the circumference of a rotating plug transporting roll is provided into which the shaped extension members extend. The lateral guide means of this duct constitute the elements of the stuffer box wall moving with the plug. The plug moves from the stuffer box between the lateral guide means along part of the circumference of the plug transporting roll and then is transferred to another transporting element where it is cooled down and subsequently is opened up into a texturized yarn.
The thread is transported by means of a transporting medium through the conveyer duct and through the outlet opening into the stuffer box. Immediately beyond the outlet opening the pressure of the transporting medium is released. The thread hits the plug forming and is crimped in the process. Formation of the plug upon insertion of the thread at the start of production is initiated under the influence of a braking or stemming force acting temporarily, e.g. of an air stream directed against the thread. During operation an equilibrium is maintained between the compressing pressure of the transporting medium pushing the plug and the friction forces on the walls braking the plug, continuous plug formation and a constant plug movement speed being established and maintained.
The quality of the texturized yarn is closely related to the uniformity of the crimping process i.e. to the uniformity of plug formation. In the absence of a plug the thread is not crimped at all. If plug formation sets in at a distance too far from the outlet opening the plug density is reduced in such a manner that crimp no longer is sufficiently intense nor sufficiently permanent. This signifies that for high thread quality the position, consistency, and speed of movement, of the plug are to be maintained as constant as possible.
In all apparatuses known thus far for continuous crimping of threads of thermoplastic material using a texturing nozzle and a stuffer box irregularities in the plug formation can occur, especially phases in which plug formation occurs too far away from the outlet opening or plug formation does not occur at all, so called blow-outs. Depending on the type of apparatus used such blow-outs are of temporary nature, i.e. plug formation is resumed spontaneously without any action being taken, or the blow-outs are stationary, i.e. the machine must be stopped before regular plug formation is obtained again.
If defective plug formation can be discovered by visual inspection only, defects frequently are not detected at all or are detected too late, in such a manner that packages of the texturized thread contain defective thread portions, caused by undetected temporary blow-outs, which are detected only in a product manufactured from the thread. Stationary blow-outs which go undetected for a while can cause production of large quantities of reject threads.
It has been the goal of the invention according to the Swiss Patent Application 2052/92 dated Jun. 30, 1992, to propose a method and an apparatus for continuous crimping of threads of thermoplastic material, using which impaired yarn quality and production of rejects, caused by instabilities in plug formation, especially caused by blow-outs, can be avoided. This goal is achieved by a method according to which for continuous crimping of a thread of thermoplastic material the thread is heated, and using a flowing transporting medium is conveyed at a thread speed through a conveyer duct and through an outlet opening into a stuffer box, is impacted and compressed under the action of braking forces in the stuffer box into a plug, in which plug form it is transported on, at a plug speed lower than the thread speed, to the cooling and opening zones, the plug formation being monitored by sensor means in the area of the outlet opening and the measuring signals scanned being processed as measuring values for a closed loop control circuit for maintaining the plug formation constant or for activating stop devices, alarm or warning devices, or at the same time for control processes and for activation of said devices.
The corresponding device comprises a texturing nozzle with a conveyer duct and with a inlet opening for a thread, with an inlet opening for a transporting medium and with an outlet opening for the thread and transporting medium, and with a stuffer box, characterized in that in the area of the outlet opening sensor means are provided for monitoring this area.
The invention cited is based on continuous and automatic monitoring of the plug formation being used for control or alarm purposes. Monitoring is effected by sensor scanning of the area of the outlet opening, e.g. by measuring the static pressure or by measuring a parameter correlated to the static pressure, in the conveyer duct near the outlet opening in close vicinity outside the outlet opening, or by optical monitoring of the stuffer box near the outlet opening, and by further processing the signals scanned by the sensor monitoring means for open or closed loop control purposes, and/or for alarm purposes.
The static pressure in the conveyer duct corresponds to the differential between the total pressure which remains substantially constant and the dynamic pressure which is proportional to the square of the flow speed. If the conveyer duct is empty (in the absence of a thread), in which condition the transporting medium can flow through the duct unhampered by any thread, the static pressure is lowest the flow speed being high. If a thread is conveyed through the duct by the medium, the stationary pressure is higher compared to the stationary pressure in the duct in the absence of a thread the medium being stemmed by the thread. If a plug builds up in the stuffer box downstream from the outlet opening, the medium is stemmed further and the static pressure increases accordingly. Static pressure is higher the closer to the outlet opening formation of a plug sets in. Measuring the static pressure in close vicinity of the outlet opening can furnish direct indications on the state of plug formation.
Similar conditions prevail concerning the static pressure in the stuffer box immediately outside the outlet opening.
In the same manner the plug formation can be monitored using optical sensors. For good quality crimping the plug formation must set in as close as possible to the outlet opening, not beyond an empirically determined distance therefrom. If the plug formation point recedes further away from the outlet opening a blow-out occurs. Using an optical sensor monitoring the stuffer box in the area of the maximum distance tolerable of the plug formation point from the outlet opening occurrence of a blow-out can be detected.
As the plug formation depends on the stemming action in the stuffer box and on plug movement, plug formation can be maintained constant by controlling these parameters. This means that monitoring the plug formation, especially monitoring of the pressure in the area of the outlet opening can be integrated as a measurement parameter into a control circuit with a proportional/integral control member the actor members of which act upon the stemming effect exerted by the stuffer box walls and/or the plug transport, in particular the speed of plug movement.
The above mentioned patent CH 2059/92 thus concentrates on the operating conditions within the nozzle.
The present invention is based on the findings that the operating conditions with in a texturing nozzle are more complex than assumed in CH 2059/92. They can be influenced by operating parameters outside the nozzle and can influence operating parameters outside the nozzle itself. Plug formation thus can be monitored at a location situated at a distance from the plug itself.
Also, further actor parameters influencing the results can be considered other than the ones proposed in EP-554642A1. In particular it is proposed now that the pressure and/or the temperature of the texturing medium (transporting air), also called "feed air" is used as an actor parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
The method according to the present invention and embodiments as design examples of the inventive apparatus are to be described in the following with reference to the Figures, the system according to CH 2059/92 being chosen as a starting point. It is shown in:
FIG. 1 a schematic lay-out of the apparatus according to EP-554642A1,
FIG. 2 a diagram of the measuring signal of a pressure measurement in the conveyer duct during the start-up phase of the apparatus according to FIG. 1 and during its operation,
FIG. 3 a diagram of the measuring signal of a pressure measurement in the conveyer duct with control circuit, warning band and alarm band,
FIG. 4 a diagram of the measuring signal of an optical sensor in the stuffer box during the start-up phase of the apparatus according to FIG. 1 and during its operation,
FIGS. 5a and 5b a texturing nozzle with a stuffer box with a measuring opening for measuring the static pressure in the conveyer duct and means for optical monitoring of the stuffer box,
FIG. 6 a texturing nozzle with a stuffer box with a means for monitoring the pressure in the stuffer box,
FIG. 7 a schematic lay-out (similar to the one in FIG. 1) of a first embodiment of the present invention,
FIG. 8 a further schematic lay-out of a second embodiment in which the device monitoring the operating parameter of the nozzle itself is complemented or is even replaced by a monitoring device scanning operating parameters outside the nozzle, and in
FIGS. 9 and 11 a modification each of the embodiment according to FIG. 8,
FIG. 10 a modification of the embodiment according to FIG. 7,
FIG. 12 a schematic lay-out of a further embodiment,
FIGS. 13 and 14 a modification each of the embodiment according to FIG. 12,
DETAILED DESCRIPTION
FIG. 1 shows a schematic lay-out of the apparatus according to EP-554642A1 based on which the method according to that application is to be explained. The apparatus comprises a nozzle element 1 with a conveyer duct 10 and an outlet opening 11 and adjacent downstream from it a stuffer box 2, which elements are shown in a section along the direction of movement of the thread F to be textured. The thread F is conveyed by means of a transporting medium M which is fed under pressure into the conveyer duct at the thread speed V F through the conveyer duct 10 and through the outlet opening 11. For heating the thread at the same time the transporting medium is provided at a raised temperature. The transporting medium M is fed under pressure into the conveyer duct 10 and its pressure is released outside the outlet opening 11. The thread F is transported through the conveyer duct and outside the outlet opening hits the plug P which is moved in turn at a plug movement speed V p and in subsequent steps is cooled down and is opened into a texturized thread.
Into the stuffer box 2 a stemming medium S can be fed under pressure against the thread under an angle μ with respect to the plug movement. The angle μ in this arrangement is to be chosen between 0° and 90° in such a manner that the flow direction of the stemming medium does not contain any component in the direction of the plug movement speed. The stemming medium S is used during the start-up period mainly but also during operation as required for initiating, or for ensuring, the plug formation by means of additional stemming action, the thread being stemmed by the stemming medium and being moved against the walls of the stuffer box and thus being additionally held back by the friction on these walls.
In the wall of the conveyer duct a measuring opening 12 is provided adjacent to which a hollow measuring room 13 is arranged. The measuring room 13 is closed except for the measuring opening and is provided with a pressure gauge 3, e.g. a piezo element, using which the pressure prevailing in the measuring room 13, which corresponds to the static pressure within the conveyer duct (area of the measuring opening), is measured.
The value p measured by the pressure gauge 3, which corresponds to the static pressure within the conveyer duct, is transmitted as measuring value into a proportional/integral P/I control device and/or into a comparator unit V. Applying the output signal (r 1 , r 2 , r 3 or r 4 ) of the control device PI either the aerodynamic stemming action in the stuffer box can be influenced by controlling the supply of the stemming medium S(r 1 ), or the mechanical friction in the stuffer box can be influenced by control W of the stuffer box wall or of the geometry of the stuffer box (r 2 ), or of the plug movement speed by controlling the speed of a plug transporting means (r 3 ) arranged adjacent to the stuffer box, or by influencing the compression action by controlling the supply of the transporting medium M(r 4 ) in such a manner that the compression pressure p corresponds to a pre-set target value P s . The pre-set target value P s can be determined by experiments and can be transmitted to the control device, or can be determined by a calibrating measurement.
The actor devices (not shown in the Figure) of the control circuit are e.g. control valves for the supply of the stemming medium or of the transporting medium, a drive unit, using which a braking member is moved into the stuffer box or using which the stuffer box is narrowed in iris-fashion, or the drive unit of a possibly provided plug transporting means arranged adjacent to the stuffer box. Control of the supply of the stemming medium is best suited in apparatuses provided with stuffer boxes with partially moving walls, control of the stuffer box walls or of their geometry (e.g. the degree of taper of the stuffer box) is best suited for apparatuses provided with stationary stuffer box walls merely, in which arrangements the adaptations required are very small (in the range of tenths of a millimeter). An iris-type movement is best suited for stuffer boxes formed by individual stationary slats. Control of the plug movement speed can be effected only if the texturing device comprises a plug transporting means arranged adjacent to stuffer box, e.g. a needle studded roll.
According to the teachings of EP-554642A1 control of the supply of the transporting medium is less advantageous as it also influences the thread temperature and thus the crimping action, but as will be discussed in the following, it now is proposed that these parameters be influenced.
The measuring value generated in the pressure measurement also can be compared in a comparator unit V with at least one measuring limit value (p 1 . . . p n ). If pre-set limit values are exceeded, e.g. an alarm lamp 4 can be activated, or the production can be stopped by severing (8) the thread. The function of the comparator unit is to be described in more detail in the following with reference to the FIGS. 2, 3 and 4.
The function of the control device PI can be effected by a proportional/integral control device commercially available on the market. For a combined control and comparator function an integral control device e.g. with an alarm band and with a stop band can be applied. If comparison merely but no control action is to be effected, the function of the comparator device V can be accomplished e.g. by a discriminator device with an adaptable threshold. The threshold values for this arrangement are determined experimentally. Of course the control function and/or the comparator function also can be established by means of software applications.
In the FIGS. 2, 3 and 4 examples of diagrams are shown of the measuring signal of a monitoring arrangement according to EP-554642A1. The measuring signal, or the physical value corresponding to the measuring signal, respectively, is plotted over time.
In the FIG. 2 a diagram is shown of the measuring signal in an arrangement using pressure measurement in the conveyer duct the measuring signal being analysed in a comparator device. The static pressure (measured in bar above or below atmospheric pressure) in the conveyer duct, corresponding to the measuring value p (e.g. electrical voltage), is plotted over the time axis t, the time span shown containing a start-up period of the apparatus, stationary operation, and the occurrence of a blow-out.
Up to the time moment A no transporting medium flows through the conveyer duct which can be closed or can be opened for preparatory steps, i.e. separated along the thread path in two duct sections. Up to this moment the static pressure in the nozzle is equal to the atmospheric pressure, the pressure measured thus equalling zero. At the time moment A the conveyer duct is closed and the transporting medium infeed is switched on, whereupon the transporting medium flows through the duct. The static pressure in the duct is lowered, and during the subsequent heating period remains constant. As soon as the texturing temperature is reached in the duct (at the time moment B) the infeed of the transporting medium is stopped, the duct is opened and the thread is inserted. At the time moment C the duct is closed and plug formation is initiated immediately, e.g. by activation of the thread stemming action applying the stemming medium S over a short time period. As the transporting medium is held back by the thread in the conveyer duct and at the plug in the stuffer box the static pressure in the conveyer duct increases and in a continuous and regular operation eventually settles in a pressure range corresponding to a range of measuring values pp. The operation can be called optimum if the range of measuring values pp is as small as possible and remains constant over long periods of time.
At the time moment D now a blow-out occurs, i.e. the point of plug formation recedes away from the outlet opening. Thus the stemming action exerted by the plug is reduced and the static pressure measured decreases, namely to a pressure corresponding to a measuring value P a which in the extreme case corresponds to the static pressure in the conveyer duct in complete absence of a stemming action of a plug.
By a measurement of the kind according to the one shown in the FIG. 2, in which the measuring value p is scanned and the plug formation is monitored, a threshold measuring value p is scanned and the plug formation is monitored, a threshold measuring value p 1 can be determined in such a manner that irregularities in the plug formation can be tolerated to a certain extent as long as they do not induce measuring value variations below the threshold measuring value p 1 . The threshold measuring value p 1 is set at a value higher than the measuring value P a corresponding to a blow-out. The threshold measuring value p 1 is set low enough to maintain a sufficient margin with respect to the range of measuring values pp in such a manner that under regular operating conditions the measuring values p do not drop into its region. The threshold measuring value p 1 is set at a sufficiently high value that the irregularities of plug formation causing impaired thread quality and/or permanent blow-outs are detected as such.
In an apparatus according to the texturing device already mentioned initially in analogy to the European Patent Nr. 310890 e.g. the following pressure conditions were found: At an infeed pressure of the transporting medium of 7 to 7.5 bar the pressure range (range of measuring values pp) under regular plug formation conditions ranged from 0.8 to 1.1 bar (above atmospheric pressure), and the pressure during the occurrence of a blow-out (measuring value p a ) was measured as 0.6 bar, under which circumstances the threshold pressure (threshold measuring value P 1 ) had to be set at about 0.7 bar.
In the FIG. 3 an example is shown of a diagram of the signal in an arrangement in which pressure measurement is effected in the conveyer duct, with a control circuit, a warning band (p 2 p 3 ) and an alarm band (p 4 /p 5 ).
Under optimum operating conditions the controlled measuring value should be maintained within the warning band. If the measuring value is outside the warning band but still within the alarm band, thread quality is not affected and production can be continued, but a warning signal W is generated (warning lamp, protocol printout) which indicates that maintenance operations (cleaning) are required soon. If the pressure measured exceeds the value P 4 , the outlet opening is clogged, and if the pressure falls below P 5 , a blow-out has occurred. In either case production must be stopped e.g. by cutting the thread.
In the FIG. 4 a diagram is shown of the measuring signal I transmitted by an optical sensor arranged in the stuffer box, plotted over the same time span as the diagram shown in the FIG. 2. The measuring signal I is e.g. the signal transmitted by an optical sensor consisting of a light source and a light sensitive cell arranged opposite each other within the stuffer box. The light emitted by the light source is directed towards the light sensitive cell, but is partially absorbed and dispersed by the thread and/or the plug. The measuring signal corresponds to the intensity of the light received by the light sensitive cell. This light intensity is high in the absence of thread in the stuffer box (I O ), and is lower (I a ) if a thread passes straight through the stuffer box, owing to the light absorption of the thread, which corresponds to a blow-out situation, and very low (range IHn) if a plug is present in the stuffer box. The threshold measuring value I s is set between I a and the upper limit of I n .
In the FIGS. 5a and 5b two embodiments of the texturing apparatus according to EP-554642A1 are shown as examples, each provided with a nozzle element 1 with shaped extension members 41 functioning as a stuffer box. The texturing nozzle in the FIG. 5b is shown in rotated by 90° with respect to the arrangement shown in the FIG. 5a (seen in the direction of arrow V in the FIG. 5a). The thread as described before is conveyed through the conveyer duct 10 and through the outlet opening 11. Immediately outside the outlet opening plug formation sets in. The plug P formed is carried on by means of a plug transporting roll 42 between teeth 43.
In the apparatus according to the FIG. 5a the compressing pressure is measured in the conveyer duct. The apparatus comprises a measuring opening 12 which leads into a hollow measuring room 13. The hollow measuring room beyond the wall can be of any shape desired and adapted to the overall arrangement. The pressure gauge (not shown in the Figure) advantageously is arranged outside the walls of the conveyer duct.
In the apparatus according to the FIG. 5b plug formation is monitored optically. The apparatus comprises a light barrier arrangement 44 which can be provided as an alternative to the hollow measuring room and the pressure gauge. It comprises e.g. a light source 44.1 and a receiver 44.2 which are arranged opposite each other at the open sides of the stuffer box in such a manner that the receiver takes up the light emitted by the light source.
In FIG. 6 a further arrangement is shown schematically as an example of a monitoring arrangement for the pressure in the area of the outlet opening. In this arrangement the dynamic pressure is measured in a infeed duct for measuring air into the stuffer box immediately outside the outlet opening.
In the Figure again the conveyer duct 10 is shown through which a thread F is conveyed, and a stuffer box 2 in which a plug P is being formed. The stuffer box 2 in the arrangement shown as an example is limited by slats 63 arranged radially with respect to the plug. In the area of the outlet opening 11 the pressure of the transporting medium is released between the slats. Measurements indicate that between the plug P and the outlet opening 11 vortices (arrows 60) form in such a manner that in close vicinity of the outlet opening a flow from the stuffer box against the thread is generated near the plug. The shape of these vortices to a large extent depends on the geometrical lay-out of the outlet opening and of the stuffer box.
If during operation now between the outlet opening and the point of plug formation the pressure at the stuffer box wall is measured by means of a fluidic nozzle in function of the distance from the outlet opening, it is found that as indicated next to the schematic lay-out of the apparatus in the FIG. 6 a below atmospheric pressure (suction) is generated immediately outside the outlet opening which over a neutral zone increases up to a pressure maximum at the point of plug formation. If now e.g. at a distance from the outlet opening at which formation of the plug sets in under optimum production conditions a fluidic nozzle 61 of the type mentioned is installed, a statement concerning the position of the plug can be made based on the pressure measured in the nozzle. A measuring signal of this type can be analysed in analogy to the measuring signal of the sensor for the compression pressure in the conveyer duct.
A fluidic nozzle is understood to be a measuring nozzle through which measuring air is flowing at constant rate and in which the compressing pressure is measured. A fluidic nozzle of this type proves most advantageous as it is self-cleaning to a high degree owing to the measuring air stream.
The hollow measuring room, or the means monitoring the stuffer box, respectively, e.g. the light barrier arrangement, advantageously are arranged as close as possible to the outlet opening.
In the FIG. 7 first development according to the present invention is shown, the reference signs according to the FIG. 1 being re-used for designating identical elements. The additions according to the FIG. 7 comprise a source Q of compressed air, a controllable valve VL for influencing the pressure of the air from the source Q, a heater H for the air supplied from the valve VL and a control device HS for the heater H. The state of the air downstream of the heater H is controlled with respect to the pressure by means of the first PI-control device already mentioned with reference to the FIG. 1 and with respect to the temperature by means of a further, second PI-control device, and this air is supplied as feed air, i.e. as transporting medium or texturing medium respectively to the apparatus 1.
The first PI-control device is connected to the valve VL via the circuit DL and the second control device is connected to the control device HS via a circuit HL. Via the circuit DL the air pressure downstream of the valve VL can be used as actor force for maintaining the above mentioned compression pressure "P" as the controlled parameter within the pre-set tolerance limits.
A commercially available pressure gauge DM as well as a commercially available temperature measuring device TM can be provided between the heater H and the inlet opening for the feed air into the apparatus 1. The output signal from the device DM is transmitted via a circuit ML to a first PI-control device in such manner that this pressure can be maintained within pre-set limit values whereas the output from the device TM is transmitted via a circuit TL to a second PI-control device which in turn transmits its signal via a circuit HL to the control device HS.
In this arrangement either the compression pressure P or the pressure signal from the circuit ML is transmitted to the first P-control device, which can be effected using a commercially available switching valve UV. The compression pressure P, however, is permanently transmitted to the comparator unit V. The output signals from the first PI-control device are either the signal r 1 for control of the stemming medium S or the signal for the controllable valve VL. The stemming medium S, however, can be controlled also by an independent control arrangement (compare FIG. 13).
In the FIG. 8 a copy of the FIG. 1 is shown amended by the following new elements:
a rotatable cooling drum T which takes over the plug P,
a sensor FSS which measures the thread tensile force, also called thread tension, after take-off of the thread from the cooling drum.
The sensor FSS transmits its output signal via a circuit FL to the PI-control device and thus influences the operating parmeters which have been described with reference to the FIG. 1, in order to maintain the thread tensile force measured by the sensor FSS within pre-set limits.
The cooling drum T shown in the FIG. 8 is laid out according to EP-0 488 939. The plug P emerging from the stuffer box is transferred at the point C onto the cooling drum T which rotates at a constant surface speed V 1 , and which is designed as a sieve drum or as a perforated roll. Air is sucked into the cooling drum which air holds the plug against the drum surface and at the same time cools it. The plug P moves with the surface of the drum and after reaching the Point D1 is lifted off the cooling drum by a corresponding deviating device (not shown) or by closing of the perforations of the cooling drum T in such a manner that the plug no longer is held by the below atmospheric pressure prevailing in the drum, i.e. that it is detached from the drum surface. The yarn 1.2 is taken off by the take-off package SP at a speed V 2 .
In the FIG. 9 the schematic lay-out according to the FIG. 7 is shown in part with amendments according to the amendments mentioned before with reference to the FIG. 8. The arrangement shown serves the same purpose as the arrangement according to the FIG. 8, the pressure, and/or the temperature respectively, of the transporting or texturing air being influenced in the present case in order to maintain the thread tension constant by transmitting the signal of the pressure gauge DM via the circuit ML to the PI-control device and by transmitting the signal of the temperature measuring device TM via the circuit TL to the control device HS.
Monitoring of the plug formation, however, opens up further possibilities also which are to be made accessible after further development of the principle proposed here. The plug formation is influenced by three types of operating parameters, namely:
1. parameters exerting an influence onto the thread which is supplied to the apparatus 1,
2. the operating parameters of the apparatus itself, and
3. the operating parameters of the subsequent processing devices, e.g. of the cooling drum.
If it proves possible to exclude, or to detect respectively, defects of one type, defects of other types can be detected owing to the monitoring of the plug formation. Application of defect detecting systems mentioned in the patent literature, e.g. mentioned in DE-A-44 14 517, can prove advantageous.
As already indicated in the discussion with reference to the FIGS. 8 and 9 the texturing device (the plug formation) also influences operating parameters which appear downstream from the device, e.g. the thread tension, and also the linear density of the thread. Based on the monitoring of such parameters the state of the texturing device can be assessed.
Known quality monitoring systems based on the measurement of thread tensile force can be found in the following patents:
DE-A-41 19 780
DE-A-44 13 549
U.S. Pat. No. 4,685,629
EP-C-207 471
Known quality monitoring systems based on the measurement of linear density of the yarn can be found in the following patents:
U.S. Pat. No. 3,731,069
U.S. Pat. No. 4,045,659
U.S. Pat. No. 3,885,232
U.S. Pat. No. 4,030,082
CH-C-551 923
It is to be noted additionally that the plug transporting means r 3 mentioned with reference to the FIG. 1 on page 8 or with reference to the FIG. 8 on page 15 either is the plug transporting roll 42 shown in the FIGS. 5a and 5b and mentioned on page 12 in connection with the method indicated and described in the European patent 310890, or is a plug transporting roll not shown here the surface of which is studded with pins taking up the plug and transferring it e.g. to a cooling drum T shown in the FIGS. 8 and 9 in which arrangement the speed Vp of the plug movement is influenced by means of the roll 42 mentioned or of a roll not shown the rotational speed of which is varied using the PI-control device.
In the FIG. 10 the schematic lay-out according to the FIG. 7 is shown in part, the elements identical in the FIG. 10 and in the FIG. 7 being designated with the same reference signs and not being re-described.
In the FIG. 10 a first control circuit is shown controlling the heating of, and a second control circuit controlling the pressure of, the transporting medium M.
In the first control circuit the output signal of a first PI-control device, provided with a target value input WT, is transmitted to the control device HS via the circuit HL.
Furthermore the first PI-control device receives a temperature signal via a circuit TL from the temperature measuring device TM.
The target value WT of the first PI-control device is adapted by a third PI-control device provided with its own target value input PS, if the pressure signal p transmitted from the pressure gauge 3 deviates from the target value, i.e. that the plug in the stuffer box does not present the desired permeability, in which case the temperature of the thread is varied until the pressure p corresponds to the target value PS.
The second control circuit contains a second PI-control device, provided with a target value input PS, which controls the pressure in the controllable valve VL taking the signal from the pressure gauge DM into account which is transmitted to the second control device via the circuit DL.1. The output signals of the second PI-control device are transmitted to the controllable valve VL via the circuit DL.
For controlling the stemming medium S a separate control circuit is provided in which the signal of a pressure gauge DM.1 provided at the infeed tube for stemming the medium into the stuffer box is transmitted to a pressure control device DR provided with a target value input PS, in which arrangement the pressure control device DR controls the pressure of the stemming medium S.
In the FIG. 11 the schematic lay-out according to the FIG. 9 is shown in part, the elements identical being designated using the same reference signs and their re-description being dispensed with here.
The arrangement shown in the FIG. 11 furthermore comprises a control circuit for controlling the pressure of the transporting medium in function of the thread tension measured using the thread tension measuring device FSS.
A second and a third control circuit, controls the temperature of the transporting medium, or the pressure of the stemming medium S, respectively, independently of the thread tension.
The first control circuit contains a first PI-control device provided with a target value input PS, which transmits an output signal via a circuit DL to the controllable valve VL and which receives an input signal from the pressure gauge DM via a circuit DL.1.
A signal from the thread tension measuring device FSS is transmitted via a circuit FL to a third PI-control device provided with a target value input WF in which arrangement the third PI-control device, if the thread tension signal differs from the target value WF, varies the target value PS of the first PI-control device until the thread tension signal corresponds to the pre-set target value WF.
The second control circuit comprises a second PI-control device provided with a target value input WT, which on one hand receives a temperature signal from the temperature measuring device TM via a circuit TL and on the other hand transmits a controlling signal via a circuit HL to the control device HS which controls the heater H.
A fourth control circuit controls the stemming air S in which arrangement the pressure gauge DM. 1 transmits a pressure signal to a pressure gauge DR provided with a target value input PS, an the pressure gauge DR generates the control signal r 1 using which the pressure of the stemming air S is controlled via a valve not shown here.
The second control circuit controls with a second PI-control device provided with a target value input WT, and controls the temperature of the transporting medium M.
In the FIGS. 12, 13 and 14 an alternative design example is shown concerning the assessment of the plug located on the cooling drum T, in which arrangement not the thread tension is measured for assessing the plug, but the position of the point on the cooling drum T at which the plug is opened again into a thread which subsequently is taken off by a take-off roll and is transferred to a winding device SP.
In this arrangement the location mentioned above on the cooling drum is detected by means of a light sensor LS which can be a light emitter and a light receiver or any means suitable for monitoring the location of this plug dissolving point and capable of transmitting a corresponding signal.
The signal given off by the sensor LS is transmitted via a circuit SL into a fourth PI-control device provided with a target value input WL, which varies a target value PS of a first PI-control device if the signal SL deviates from the target value WL until the signal SL coincides with the target value WL.
The first PI-control device of FIG. 12 in turn receives an input signal from a pressure gauge DM1 which measures the compressing pressure at the inlet tube of the stemming air and transmits the compressing pressure signal to the first PI-control device. The first PI-control device on the other hand generates the pressure signal r 1 using which the pressure of the stemming air S is controlled.
A second control circuit with a second PI-control device provided with a target value input WT, controls the temperature of the transporting medium M.
The second PI-control device receives a temperature signal from the temperature measuring device and transmits a controlling signal via a circuit HL to the control device HS.
A third control circuit controls the pressure of the transporting medium M in which arrangement a third PI-control device provided with a target value input PS receives a pressure signal from the pressure gauge DM via a circuit DL.1 and transmits a control signal via a circuit DL to the controllable valve VL.
Furthermore it is to be mentioned that the angle β which is limited by the point C at which the plug is transferred to the cooling drum and by the point at which the plug is dissolved, is called cooling angle β.
In the FIG. 13 the schematic lay-out of the FIG. 12 is shown in part, the identical elements being designated with the same reference signs and not being re-described again.
In the FIG. 13 three control circuits are shown, namely a first control circuit with a first PI-control device using which the temperature of the transporting medium is controlled in function of the position of the point on the cooling drum T at which the plug is opened or dissolved, and a second control circuit with a second PI-control device using which the pressure of the transporting medium M is controlled, as well as a third control circuit with a pressure control device DR using which the stemming air is controlled.
In connection with the first control circuit the signal SL of the light sensor LS in analogy to the arrangement shown in the FIG. 12 is transmitted to a fourth PI-control device provided with a target value input WL, in which arrangement the fourth PI-control device varies the target value input PS of the first PI-control device until the signal SL corresponds to the target value PL of the fourth PI-control device.
In this arrangement the first PI-control device receives a temperature signal from the temperature measuring device TM via the circuit TL and transmits a control signal via a circuit HL to the control device HS for controlling the heater which heats the transporting medium M.
The second control circuit corresponds to the third control circuit shown in the FIG. 12, the only difference being that the PI-control device is designated as the second PI-control device; therefore a further description of this control circuit is dispensed with.
The control circuit for the stemming air corresponds to the one shown in the FIG. 10, and in the FIG. 11 respectively.
In the FIG. 14 part of the elements shown are identical to the ones shown in the FIGS. 11, 12 and 13; the elements identical thus are designated using the same reference signs and are not re-described here.
In the FIG. 14 also three control circuits are shown; similarly as in the FIG. 13, in which arrangement the first control circuit, however, does not control the temperature of the transporting medium M, but the pressure in function of the position of the point at which the plug on the cooling drum T is dissolved.
Accordingly the first PI-control device transmits a control signal via the circuit DL to the controllable valve VL and receives an input signal from the pressure gauge DM via the circuit DL.1.
The first PI-control device contains a target value input PS which is varied by a third PI-control device until the signal of the light sensor corresponds to a target value input WL of the third PI-control device.
The second control circuit comprises the second PI-control device provided with a target value input PS which receives a temperature signal from the temperature measuring device TM via the circuit TL and transmits a control signal via the circuit HL to the control device HS.
The control of the stemming air, which is effected in the third control circuit, is identical to the one described with reference to the FIGS. 10, 11 and 13.
It is to be noted that the present invention is not limited to the embodiments shown in the Figures but that within the scope of the invention a predetermined number of adjustment parameters and a predetermined number of measuring parameters can be combined, namely the adjustment parameter for adjusting the pressure of the transporting medium, the adjustment parameter for adjusting the temperature of the transporting medium for heating the thread, and the adjustment parameter for adjusting the stemming air flow for at least initiating the compression of the thread in the stuffer box, as well as the measuring parameter indicating the compression pressure in the conveyer duct, the thread tension as a further measuring parameter, as well as the cooling angle β, or the position respectively of the point at which the plug on the cooling drum is dissolved as a third measuring parameter, in which arrangement the adjusting parameters and the measuring parameters are combined in the framework of a matrix the adjusting parameters e.g. being listed in the abscissa direction and the measuring parameters being listed along the axis of ordinates, which matrix furnishes corresponding combinations. This signifies that within the scope of the present invention also other adjusting parameters and other measuring parameters can be chosen and can be combined. | The present invention relates to a method for continuous crimping of a thermoplastic material thread. According to the method, a transporting medium is pressurized, the transporting medium is heated, and a thread is transported, with the transporting medium, though a conveyor duct and out of an outlet opening of the conveyor duct at a transporting speed. The thread is transported from the outlet opening of the conveyor duct to an inlet opening of a stuffer box. The thread is compressed into a plug in the stuffer box by decelerating the thread. The plug is transported from an outlet opening of the stuffer box at a plug speed that is lower than the transporting speed such that the plug is cooled and opened to form a texturized and tensioned thread. At least one parameter of the plug is measured. The at least one measured parameter is compared with a target value of the at least one measured parameter. At least one signal is sent to at least one dependent control circuit when there is a difference between the at least one measured parameter and the target value of the at least one measured parameter. With the at least one dependent control circuit, at least one of a pressure of the transporting medium, a temperature of the transporting medium, and deceleration of the thread in response to the at least one signal is controlled. With at least one independent control circuit, at least one of a pressure of the transporting medium, a temperature of the transporting medium, and deceleration of the thread that are not controlled by the dependent control circuit is controlled. An apparatus for crimping thermoplastic threads is also disclosed. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 10/801,289, filed Mar. 16, 2004, now U.S. Pat. No. 7,090,021, which claims benefit of U.S. patent application Ser. No. 09/762,606, filed May 21, 2001, now U.S. Pat. No. 6,705,405, which is the National Stage of International Application No. PCT/GB99/02708, filed Aug. 16, 1999, which claims benefit of Great Britain Patent Application No. GB9818360.1, filed Aug. 24, 1988. Each of the aforementioned related patent applications is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an apparatus for facilitating the connection of tubulars using a top drive and is more particularly, but not exclusively, intended for facilitating the connection of a section or stand of casing to a string of casing.
SUMMARY OF THE INVENTION
[0004] In the construction of oil or gas wells it is usually necessary to line the borehole with a string of tubulars known as a casing. Because of the length of the casing required, sections or stands of say two sections of casing are progressively added to the string as it is lowered into the well from a drilling platform. In particular, when it is desired to add a section or stand of casing the string is usually restrained from falling into the well by applying the slips of a spider located in the floor of the drilling platform. The new section or stand of casing is then moved from a rack to the well centre above the spider. The threaded pin of the section or stand of casing to be connected is then located over the threaded box of the casing in the well and the connection is made up by rotation there between. An elevator is then connected to the top of the new section or stand and the whole casing string lifted slightly to enable the slips of the spider to be released. The whole casing string is then lowered until the top of the section is adjacent the spider whereupon the slips of the spider are re-applied, the elevator disconnected and the process repeated.
[0005] It is common practice to use a power tong to torque the connection up to a predetermined torque in order to make the connection. The power tong is located on a platform, either on rails, or hung from a derrick on a chain. However, it has recently been proposed to use a top drive for making such connection. The normal use of such a top drive may be the driving of a drill string.
[0006] A problem associated with using a top drive for rotating tubulars in order to obtain a connection between tubulars is that some top drives are not specifically designed for rotating tubulars are not able to rotate at the correct speed or have non standard rotors.
[0007] According to the present invention there is provided an apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising a motor for rotating a tool for drivingly engaging a tubular, and means for connecting said motor to said top drive, the apparatus being such that, in use, said motor can rotate one tubular with respect to another to connect said tubulars.
[0008] Other features of the invention are set out in Claims 2 et seq.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For a better understanding of the present invention and in order to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:
[0010] FIG. 1 is a front perspective view of an apparatus in accordance with the present invention; and
[0011] FIG. 2 is a rear perspective view of the apparatus of FIG. 1 in use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] Referring to FIG. 1 there is shown an apparatus which is generally identified by reference numeral 1 .
[0013] The apparatus 1 comprises a connecting tubular 2 , a suspension unit 3 and a hydraulic motor 4 and 4 ′. The hydraulic motor 4 , 4 ′ has a stator 5 and a rotor 6 and is driven by a supply of pressurised hydraulic fluid (the fluid supply lines are not illustrated in the Figures). The suspension unit 3 suspends the hydraulic motor 4 , 4 ′ from the connecting tubular 2 .
[0014] The suspension unit 3 comprises a plate 7 which is fixed to the connecting tubular 2 by a collar 8 . The plate 7 has two projections 9 and 10 which have holes 11 and 12 for accommodating axles 13 and 14 , which arc rotationally disposed therein. The axles 13 and 14 are integral with a rigid body 15 . A slider 16 is arranged on runners 17 and (not shown) on the rigid body 15 . Arms 18 and 19 are connected at one end to the slider 16 via spherical bearings 20 and at the other end to each side of the stator 5 via spherical bearings 21 and 21 ′. The arms 18 and 19 are provided with lugs 22 and 22 ′ to which one end of a piston and cylinder 23 , 24 is attached and are movable thereabout. The other end of each piston and cylinder 23 , 24 is attached to lugs 25 , 26 respectively and is movable thereabout. A mud pipe 27 is provided between the plate 7 and the stator 5 for carrying mud to the inside of a tubular therebelow. The mud pipe 27 comprises curved outer surfaces at both ends (not shown) which are located in corresponding recesses in cylindrical sections 28 , 29 , thus allowing a ball and socket type movement between the plate 7 and the stator 5 .
[0015] Referring to FIG. 2 , the apparatus 1 is suspended from a top drive (not shown) via connecting shaft 2 . A tool 30 for engaging with a tubular is suspended from beneath the rotor 6 of the hydraulic motor 4 . Such a tool may be arranged to be inserted into the upper end of the tubular, with gripping elements of the tool being radially displaceable for engagement with the inner wall of the tubular so as to secure the tubular to the tool.
[0016] In use, a tubular (not shown) to be connected to a tubular string held in a spider (not shown) is located over the tool 30 . The tool 30 grips the tubular. The apparatus 1 and the tubular are lowered by moving the top drive so that the tubular is in close proximity with the tubular string held in the spider. However, due to amongst other things manufacturing tolerances in the tubulars, the tubular often does not align perfectly with the tubular held in the spider. The suspension unit 3 allows minor vertical and horizontal movements to be made by using alignment pistons 31 and 32 for horizontal movements, and piston and cylinders 23 and 24 for vertical movements. The alignment piston 31 acts between the rigid body 15 and the plate 7 . The alignment piston 32 acts between the slider 16 and the arm 19 . The alignment pistons 31 and 32 and pistons and cylinders 23 , 25 are actuated by hydraulic or pneumatic means and controlled from a remote control device.
[0017] The piston and cylinders 23 , 24 are hydraulically operable. It is envisaged however, that the piston and cylinders 23 , 24 may be of the pneumatic compensating type, i.e. their internal pressure may be adjusted to compensate for the weight of the tubular so that movement of the tubular may be conducted with minimal force. This can conveniently be achieved by introducing pneumatic fluid into the piston and cylinder 23 , 24 and adjusting the pressure therein.
[0018] Once the tubulars are aligned, the hydraulic motor 4 and 4 ′ rotate the tubular via 15 gearing in the stator 5 thereby making up the severed connection. During connection the compensating piston and cylinders 23 , 24 expand to accommodate the movement of the upper tubular. The alignment pistons 31 and 32 can then be used to move the top of the tubular into alignment with the top drive. If necessary, final torquing can be conducted by the top drive at this stage, via rotation of the pipe 27 , and the main elevator can also be swung onto and connected to the tubular prior to releasing the slips in the spider and lowering the casing string. It will be appreciated that the suspension unit 3 effectively provides an adapter for connecting a top drive to the tubular engaging tool 30 . | An apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising a motor ( 4, 4′ ) for rotating a tool ( 30 ) for drivingly engaging a tubular, and means ( 3 ) for connecting said motor ( 4, 4′ ) to said top drive, the apparatus being such that, in use, said motor ( 4, 4′ ) can rotate one tubular with respect to another to connect said tubular. | 4 |
This is a continuation-in-part application of international application PCT/EP97/03822 filed Jul. 17, 1997, and claiming the priority of German application 196 38 563.6 filed Sep. 20, 1996.
BACKGROUND OF THE INVENTION
The invention relates to a method of growing monocrystals from a highly pure poly-crystalline material melt.
Such a method is known in principle, for example, from D. T. J. Hurle: Handbook of Crystal Growth 2a Basic Techniques, North Holland (1994), page 102 ff.
In a crucible consisting of quartz, an amount of silicon is molten and heated to maintain the silicon in a molten state. The crucible is disposed on a graphite containment. The melt is heated by heating rods transmitting heat by radiation to the graphite and from the graphite to the quartz crucible. From the quartz crucible, heat is transferred to the melt by heat conduction. The single crystal is drawn from the melt in the usual way.
This method however has a serious disadvantage in that the crucible needs to be hotter than the melt. The excess temperature of the crucible is greater the larger the diameter of the single crystal and, consequently, of the melt bath is. With increasing diameter of the melt bath, the heat flow through the quartz crucible must be increased so that also the temperature gradient providing for the increased heat flow from the quartz crucible to the melt is increased. As a result, the crucible becomes soft and, furthermore, a reaction occurs between the crucible and the melt whereby oxygen and crucible material are transferred to the melt thereby contaminating the melt.
It is the object of the present invention to provide a method of drawings single crystals from a melt wherein, during the melting of the crystal material and the heating of the melt, the melt remains in a highly pure state.
SUMMARY OF THE INVENTION
In a method of drawing single crystals from a body of highly pure polycrystalline material molten by inductive heating, a solid body of the polycrystalline material is first heated by direct induction heating at a frequency >200 KHz to increase its conductivity and is then further heated by direct induction heating at a frequency <20 KHz to melt the center of the body of polycrystalline material to form a molten pool contained by a marginal solid zone of the polycrystalline material from which the single crystal is drawn.
By the inductive heating of the melt, the energy is applied directly to the melt volume. The outer areas of the molten mass can be maintained cooler than the center area of the bath. As a result, no contaminants are imported from the outside and radiation losses to the ambient are minimized. It also makes it possible to perform the crystal drawing process in a continuous manner.
Below, two embodiments of the invention will be described on the basis of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show schematically different arrangements for heating the melt,
FIGS. 3 and 4 show schematically an arrangement for heating the melt in accordance with the method of the present invention, and
FIGS. 5 and 6 show the temperature distribution in the material melt at different induction heating frequencies.
DESCRIPTION OF PREFERRED EMBODIMENTS
The method according to the invention facilitates the drawing of single crystals from semiconductor materials such as silicon, germanium- and gallium- arsenide and from ion salts.
As base material, polycrystalline solid bodies (solidified melts or bodies formed by crystallization from the vapor phase) or sintered bodies and stampings may be used.
The two embodiments are different because of the different heat conductivities of the base material.
If polycrystalline solid base bodies of high heat conductivity are used, there are three possibilities for increasing the electric conductivity in the first heating stage.
FIG. 1 shows a heating arrangement for heating a polycrystalline solid body by heat radiation.
The solid body 1 is surrounded by a radiation heat source 5. The radiation heat source 5 may comprise an arrangement of electric heating rods which are distributed over the circumference of the crucible and which are retracted downwardly or otherwise removed after the heating procedure is completed. It may alternatively comprise a radiation shield consisting of a heat resistant material which is maintained at a temperature close to the melting point of the material to be melted by means of an induction coil 4. This shield heats the solid body by radiation heating with an energy of about 40 KW to a temperature which is sufficient to increase the electric conductivity of the polycrystalline solid body to such a degree that an inductive field applied thereto can input sufficient energy into the body to cause its melting. The heat losses of the heat shield to the outside can be greatly reduced by a thermally and electrically non-conductive insulation structure 6. This heat insulation structure is moved, together with the heat shield downwardly after completion of the heat-up procedure or is otherwise removed.
If the transmission frequency of the induction coil is so selected that it is sufficiently high (for silicon greater than 200 KHz) to generate also in the cold solid body more energy than is lost by radiation from its surface, the heat-up procedure by heat radiation may be eliminated. In that case, however, after reaching a temperature, which is about 100° K. below the melting point of the solid body, either the heat-up coil 4 has to be replaced by an operating coil or the frequency of the coil 4 must be reduced from >200 KHz down to <10 KHZ.
FIGS. 5 and 6 show the results of calculations for the heat-up phase and for the continuous operation of a silicon melt in a body of 0.4 m diameter.
In accordance with these calculations, a power input of 150 KW/m at a frequency of 200 KHz is applied during the heat-up phase. The dimension KW/m relates to the energy absorbed by a test body length of 1 m. When, after about 2400 seconds, a temperature in the solid body of about 100° K. below the melting point of silicon of 1693° K. has been reached, the frequency of 200 KHz is switched to 2 KHz while the energy applied remains first unchanged until the silicon in the center begins to melt. Then the energy supply is reduced to a value of about 65 KW/m which is required for continuous operation.
Another heat-up method or startup procedure is shown in FIG. 2. In this case, a melt 2 is supplied to a cavity in a solid body, sinter body or formed body consisting of the same material as the melt while an induction field is applied thereto. The melt 2 absorbs a greater amount of energy because of the greater conductivity of the molten material. Starting with the melt in the center, the body can be melted except for a residual colder solid crust.
In order to maintain the crust, heat must be conducted out of the crust to the ambient. With the arrangement as shown in FIG. 3, this heat can be removed only by heat radiation since the melting and drawing process is performed under a vacuum or in a cover gas atmosphere.
The amount of heat to be removed is smaller the thicker the crust is permitted to be.
With a diameter of the solid body of 0.4 m, a height of the melt bath also 0.4 m, a crust thickness of 2 cm and a drawing speed of 5 cm/h, an induction energy of about 40 KW is required. If radiation heat reflectors 8 of an electrically insulating material are arranged at the upper edge of the crust as shown schematically in FIG. 3, the crust melts completely at the top end of the body 1.
With such an arrangement, a continuous crystal drawing procedure for drawing a crystal 3 can be obtained if, as indicated in FIG. 3 by the bottom arrow, polycrystalline material is supplied from the bottom.
The heat losses can be reduced drastically if, in place of the polycrystalline solid body, a sinter body or a pressed body of a polycrystalline material is used as the basic material.
With this type of basic material, the heat conductivity to the polycrystalline solid body is substantially reduced.
If this concept is utilized, a guide tube 9 of quartz or, respectively, sinter ceramics encloses the basic material. A piston 10 moves the body 1 upwardly in accordance with the consumption of the basic material.
The upper edge of the crust is melted because there, the cooling of outer area is less intense.
In this arrangement, the operating coil 7 is used at the same time for the cooling of the guide tube 9.
The method according to FIG. 3 and FIG. 4 is particularly suitable for the melting of ion crystals such as alkaline bromides, (NaBr, Kbr, AgBr, CuBr) alkalichlorides (LiCl, NaCl, KCl, CsCl, CaCl 2 ) alkalifluorides (LiF, NaF, KF) alkali iodides (NaI, KJ), the bromides of Ag, Cu and Sb, the chlorides of Ag, Cu and Mn, and the iodides of Ag and Sb.
In these materials, the electric and heat conductivities are greatly increased when their melting point is reached. With minimal heat radiation losses, the crystal drawing process from the melt with a crucible formed by the melt material can be performed with only a relatively low inductive heat input. | In a method of drawing single crystals from a body of highly pure polycrystalline material molten by inductive heating, a solid body of the polycrystalline material is first heated by direct induction heating at a frequency >200 KHz to increase its conductivity and is then further heated by direct induction heating at a frequency <20 KHz to melt the center of the body of polycrystalline material to form a molten pool contained by a marginal solid zone of the polycrystalline material from which the single crystal is drawn. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 14/082,800 (currently pending, filed 19 Nov. 2013), which was a continuation-in-part of U.S. patent application Ser. No. 13/493,172 (filed 11 Jun. 2012, now issued as U.S. Pat. No. 8,586,303), which was a continuation-in-part of U.S. patent application Ser. No. 12/999,138 (filed 15 Dec. 2012, now issued as U.S. Pat. No. 8,614,072), which was the United States national stage application of International Patent Application No. PCT/US2009/003595 (filed 16 Jun. 2009), which claims the benefit of U.S. Provisional Patent Application No. 61/132,225 (filed 17 Jun. 2008). This application is also a continuation-in-part of co-pending U.S. patent application Ser. No. 14/138,532 (filed 15 Jan. 2014), which was a continuation-in-part of U.S. patent Application Ser. No. 12/999,138. The disclosures of all of these applications are hereby incorporated by reference in their entirety, including all figures, tables and sequences.
STATEMENT OF RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED RESEARCH
This invention was made with government support under Defense Threat Reduction Agency grant HDTRA1-08-0052. The government has certain rights in the invention.
THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK
None
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to nucleotide analogs and their derivatives (termed non-standard nucleotides) that, when incorporated into DNA and RNA, expand the number of replicatable nucleotides beyond the four found in standard DNA and RNA. The invention further relates to processes that incorporate those non-standard nucleotide analogs into oligonucleotide products using the corresponding triphosphate derivatives, and more specifically, polymerases and non-standard nucleoside triphosphates that support the polymerase chain reaction (PCR) reaction with these, including PCR where the products contain more than one non-standard nucleotide.
2. Description of the Related Art
Natural oligonucleotides bind to complementary oligonucleotides according to the well-known rules of nucleobase pairing first elaborated by Watson and Crick in 1953, where adenine (A) pairs with thymine (T) (or uracil, U, in RNA), and guanine (G) pairs with cytosine (C), with the complementary strands anti-parallel to each other. These rules arise from two principles of complementarity, size-complementarity (large purines pair with small pyrimidines) and hydrogen bonding complementarity (hydrogen bond donors pair with hydrogen bond acceptors).
It is now well established in the art that the number of independently replicable nucleotides in DNA can be increased, where the size- and hydrogen binding complementarities are retained, but where different heterocycles (nucleobase analogs) attached to the sugar-phosphate backbone implement different hydrogen bonding patterns. As many as eight different nucleobase analogs forming four additional nucleobase pairs are conceivable (see, for example, [Benner, S. A. (1995) Non-standard Base Pairs with Novel Hydrogen Bonding Patterns. U.S. Pat. No. 5,432,272 (Jul. 11, 1995)]). This has led to an “artificially expanded genetic information system” (AEGIS). The ability of pairing between the additional nucleobase pairs to support DNA duplex stability has had substantial use in diagnostics. In this disclosure, DNA includes oligonucleotides containing AEGIS nucleic acids and their analogs in linear and non-linear topologies, including as dendrimers, comb-structures, and nanostructures, and these oligonucleotides and their analogs carrying tags (e.g., fluorescent, functionalized, or binding) to the ends, sugars, or nucleobases.
It would be useful to amplify oligonucleotides containing AEGIS components in processes analogous to the well-known polymerase chain reaction (PCR), here defined as a process involving thermal cycling, where the heat step denatures a duplex formed at each cycle to allow a new set of primers to bind. If PCR could be implemented with expanded DNA AEGIS alphabets, it would have many uses, including (without limitation) DNA and RNA-targeted diagnostics, and in vitro selection and evolution to create catalysts, ligands, and receptors.
Various items in the art describe efforts to use the U.S. Pat. No. 5,432,272 nucleobases with polymerases to support PCR. However, these generally failed to sustain PCR over more than five heat-cool cycles, since polymerases that incorporate non-standard base pairs into duplexes with sufficient efficiency and fidelity to support PCR were not described. This failure is illustrated by Johnson et al. [Johnson, S. C., Sherrill, C. B., Marshall, D. J., Moser, M. J., Prudent, J. R. (2004) A third base pair for the polymerase chain reaction: inserting isoC and isoG. Nucl. Acids Res. 32, 1937-1941], who attempted to incorporate the isocytosine and isoguanine disclosed in U.S. Pat. No. 5,432,272 into PCR. As their publication shows, the non-standard component is not retained in the product, to an extent greater than 90% over 5 cycles. Indeed, their FIG. 2 showed that only ˜90% of the isoC:isoG pair remained after just one cycle, and only ˜80% was retained after seven cycles. This can be used as a metric for the utility of a PCR process that incorporates a non-standard nucleobase pair. In this case, the loss was attributed to the ability of a minor tautomeric form of isoguanosine to pair with thymidine, as well as contacts that thermostable polymerases (the kind that are needed for useful PCR, as they survive heating to at least 80° C. for the purpose of separating strands) make to unshared electrons in the minor groove, which are delivered by DNA from the exocyclic C═O groups of C and T, and N3 of A and G.
Many enzymes work well with AEGIS components, including kinases, ligases, and even ribosomes [Bain, J. D., Chamberlin, A. R., Switzer, C. Y., Benner, S. A. (1992) Ribosome-mediated incorporation of non-standard amino acids into a peptide through expansion of the genetic code. Nature 356, 537-539]. Polymerases, in contrast, accept many non-standard components of DNA only inefficiently, judging by rate, processivity, fidelity, or some combination of these [Horlacher, J., Hottiger, M., Podust, V. N., Hübscher, U. and Benner, S. A. (1995) Expanding the genetic alphabet: Recognition by viral and cellular DNA polymerases of nucleosides bearing bases with non-standard hydrogen bonding patterns, Proc. Natl. Acad. Sci. 92, 6329-6333]. These inefficiencies need not prevent the utility of polymerase-based incorporation of AEGIS components in single pass experiments, and may not be apparent with standing start experiments, where the non-standard triphosphate is the first nucleotide to be added to a primer, or a running start experiment, where the polymerase adds standard nucleotides before it is challenged to incorporate a non-standard nucleotide. However, they defeat sustained amplification by PCR where over 90% of the nucleobase is retained after the first theoretical cycle, here defined as “useful PCR”.
Thus, U.S. Pat. No. 5,432,272 nor the prior art do not enable useful PCR of DNA containing non-standard nucleotides (AEGIS components). While it is recognized by those of ordinary skill in the art, and taught here, that PCR processes invariably introduce some mutations, and that some daughter oligonucleotides will not have the exact identical sequence as the original oligonucleotide (and indeed, sequence evolution due to this infidelity is useful for doing in vitro evolution, see U.S. Pat. No. 8,586,303), PCR amplification of these oligonucleotides would be most useful if the level of mutation is lower rather than higher, preferably less than a 5% loss of the non-standard nucleobase per cycle, and more preferably less than a 2% loss of the non-standard nucleobase per cycle, and in any case retaining 90% of the AEGIS component after the first cycle.
U.S. Pat. No. 8,354,225 (Ser. No. 11/371,497) attempted to achieve a less ambitious process, here with an extra nucleotide pair formed between diaminopyrimidine and either xanthosine or 5-azo-7-deazaxanthosine, one that did not involve thermocycling. This was shown to be possible with a mutant form of the reverse transcriptase from HIV. Unfortunately, reverse transcriptases are not thermally stable upon heating to 80° C. (or, in most cases, even above 50° C.), and therefore cannot support PCR. Indeed, U.S. Pat. No. 8,354,225 required an addition of more reverse transcriptase after each heat step. Further, the other pyrimidine nucleoside analogs that U.S. Pat. No. 8,354,225 disclosed had nucleobases based on a pyrazine ring system, now known to epimerize rapidly. Finally, the structure disclosed by U.S. Pat. No. 8,354,225 to implement the purine analog with a hydrogen bond donor-donor-acceptor pattern is now known to be nonfunctional, and the pyrimidine analog shown to implement the hydrogen bond donor-donor-acceptor pattern lacks a methyl group and is now known to be unstable with respect to depyrimidinylation. FIG. 1 summarizes these deficiencies.
For these reasons, despite the widespread recognition of the value of PCR using non-standard nucleobases, if it could be achieved, many in the art considered this goal unachievable.
BRIEF SUMMARY OF THE INVENTION
This invention covers processes for the PCR amplification of oligonucleotides that incorporate designated components of an artificially expanded genetic information system ( FIG. 2 ), as well as the compositions of matter that those amplifications produce, as well as polymerases that accept them.
BRIEF DESCRIPTION OF THE DRAWINGS
Drawing 1. FIG. 1 . Implementations of AEGIS nucleobases disclosed by U.S. Pat. No. 8,354,225. The nucleobase implementing the puDDA pattern suffers from large tautomeric ambiguity. The implementations on pyrazine rings suffer from facile epimerization. The implementation on a simple pyridine is too basic and prone to oxidation.
Drawing 2. FIG. 2A . The presently preferred embodiments of the non-standard AEGIS nucleobases and their pairs. These have a Watson-Crick geometry, with large purines or purine analogs (indicated by “pu”) pairing with small pyrimidines or pyrimidine analogs (indicated by “py”) joined by hydrogen bonds. The hydrogen-bonding acceptor (A) and donor (D) groups are listed from the major to the minor groove as indicated. Electron density presented to the minor groove is shown by the shaded lobes. Note that some non-standard pyrimidines do not present this density.
Drawing 3. FIG. 2B . The presently preferred embodiments of the non-standard AEGIS nucleobases and their pairs. These have a Watson-Crick geometry, with large purines or purine analogs (indicated by “pu”) pairing with small pyrimidines or pyrimidine analogs (indicated by “py”) joined by hydrogen bonds. The hydrogen-bonding acceptor (A) and donor (D) groups are listed from the major to the minor groove as indicated. Electron density presented to the minor groove is shown by the shaded lobes. Note that some non-standard pyrimidines do not present this density.
Drawing 4. FIG. 3 . PCR products incorporating K:X pairs (Example 1) showing variants of the DNA polymerase 1 from Thermus aquaticus that PCR amplify products by incorporating dKTP opposite template X and dXTP opposite template K. The polymerases have replaced aspartic acid at position 548 by glycine, arginine at position 657 by glycine, aspartic acid at position 548 by leucine, aspartic acid at position 548 by a glycine, and arginine at position 657 by glycine.
Drawing 5. FIG. 4 : PAGE (16%) showing PCR amplification of decreasing amounts of template molecules containing a T or isoG using standard dNTPs with the T template and adding, MeisoCTP/isoGTP with the isoG template. Samples are loaded such that the [−/+] indicates [−treatment/+BglII digestion]; the [−/+/+] indicates [−treatment/+BglII digestion/+acid hydrolysis]. Only the isoC template PCRs were subjected to acid hydrolysis. Full length product (FLP) is 60 nt, the digestion product is 34 nucleotides and the primer is 21 nucleotides.
Drawing 6. FIG. 5 : PAGE (16%) showing PCR amplification of decreasing amounts of template molecules containing an isoC or pseudoC using standard dNTPs with MeisoCTP/isoGTP or with pseudoCTP/7-deazaisoGTP. Samples are loaded so that the [−/+/+] indicates [−treatment/+BglII digestion/+acid hydrolysis] and the [−/+] indicates [−treatment/+BglII digestion]. Only the MeisoC template PCRs were subjected to acid hydrolysis. Full length product (FLP) is 60 nt, the digestion product is 34 nucleotides and the primer is 21 nucleotides.
Drawing 7. FIG. 6 : PAGE (16%) showing PCR amplification of decreasing amounts of template containing a MeisoC or MepseudoC using standard dNTPs with MeisoCTP/isoGTP or with MepseudoCTP/cyclic 7-deazaisoGTP. Samples are loaded such that the [−/+/+] indicates [−treatment/+BglII digestion/+acid hydrolysis] and the [−/+] indicates [−treatment/+BglII digestion]. Only the isoC template PCRs were subjected to acid hydrolysis. Full length product (FLP) is 60 nt, the digestion product is 34 nucleotides and the primer is 21 nucleotides.
Drawing 8. FIG. 7A . PAGE gels showing, from Example 3, PCR amplification of DNA duplexes containing two consecutive non-standard Z:P pairs. Left panel shows PCR with two units of Deep Vent (exo+). Right panel shows PCR with one unit of Deep Vent (exo+).
Drawing 9. FIG. 7B . PAGE gels showing, from Example 3, PCR amplification of DNA duplexes containing two consecutive non-standard Z:P pairs. Left panel shows PCR with two units of Deep Vent (exo+). Right panel shows PCR with one unit of Deep Vent (exo+).
Drawing 10. FIG. 8A . PAGE gels showing, from Example 3, PCR amplification of DNA duplexes containing three consecutive non-standard Z:P pairs. Polymerases are as indicated.
Drawing 11. FIG. 8B . PAGE gels showing, from Example 3, PCR amplification of DNA duplexes containing three consecutive non-standard Z:P pairs. Polymerases are as indicated.
Drawing 12. FIG. 9A . PAGE gels showing, from Example 3, PCR amplification of DNA duplexes containing four consecutive non-standard Z:P pairs. Polymerases are as indicated.
Drawing 13. FIG. 9B . PAGE gels showing, from Example 3, PCR amplification of DNA duplexes containing four consecutive non-standard Z:P pairs. Polymerases are as indicated.
Drawing 14. FIG. 10 . PAGE gels showing, from Example 4, PCR of DNA duplexes containing Z:P pairs. (a) Standard template (Bsp-G) and AEGIS template (Bsp-P) amplified with Taq polymerase in 1× ThermoPol buffer (pH 8.0), followed by digestion with Bsp120I. Four standard dNTPs (each 0.2 mM), dZTP=0.2 mM, and dPTP=0.2 mM. Extent of digestion equals extent of loss, proving “useful PCR”. Lanes 1 and 2: Standard template amplified 10 4 fold using Taq, without (lane 1) and with (lane 2) dZTP and dPTP; Lanes 3, 4, and 5: Synthetic template, 10 3 (lane 3), 10 4 (lane 4), and 10 5 (lane 5) fold amplification, with dZTP and dPTP; Not digested: indicates fraction of PCR product retaining Z:P pair, resisting Bsp120I digestion; Digested: indicates fraction of PCR product digested. The retention rate of Z:P pair is ca. 99.2% per theoretical PCR cycle; the gain of Z:P pair in the sequence is ˜0.6% per theoretical cycle. (b) Standard template (Bsp-G, Table 1) and AEGIS template (Bsp-P, Table 1) were amplified using Taq DNA polymerase in 1× ThermoPol buffer (pH 8.0), followed by digestion with Bsp120I. dNTPs indicates dA,T,G/TPs (each 0.1 mM), dZTP=0.05 mM, dPTP=0.6 mM, and various dCTP concentration (0.2 mM, 0.4 mM, or 0.6 mM). Lane 1 and 2: Standard template was amplified 10 4 fold using Taq, without (lane 1) and with (lane 2) dZTP and dPTP; Lane 3, 4, and 5: Synthetic template, 10 3 (lane 3), 10 4 (lane 4), and 10 5 (lane 5) fold amplification, with both dZTP and dPTP; Not digested: indicates the fraction of PCR product retained Z:P pair, therefore, resisted endonuclease digestion; Digested: indicates the fraction of PCR product was digested.
Drawing 15. FIG. 11 . PAGE gels showing, from Example 5, six-letter PCR under optimized triphosphate concentrations (dZTP=0.05 mM, dPTP=0.6 mM, dA,T,G/TPs=0.1 mM, and dCTP=0.2, 0.4, or 0.6 mM) containing Z:P pairs. Standard template (Bsp-G, Table 1) and synthetic template (Bsp-P, Table 1) were amplified using Taq DNA polymerase in 1× ThermoPol buffer (pH 8.0), followed by digestion with Bsp120I endonuclease. The extent of digestion is equal to the extent of loss after the indicated number of cycles, proving a “useful PCR”.
Drawing 16. FIG. 12 . RNA made by transcribing DNA templates using T7 RNA polymerase resolved on a 3% agarose gel stained with ethidium bromide. Lane 1 and 11, abnova RNA ladder. Lanes 2 and 10, Century RNA ladder. Lane 3 shows product using standard template 01, lanes 4, 5 and 6 show products with Z-containing templates to generate P-containing RNA. Lanes 7, 8, and 9 show products with P-containing templates to generate Z-containing tRNA. Lanes 3-9 contain transcription products using templates 01-07, respectively. The correct size (˜77 mts) RNA product is visualized.
Drawing 17. FIG. 13A . Synthesis of tricyclic analog of 7-deazaisoguanosine and its triphosphate.
Drawing 18. FIG. 13B . Synthesis of tricyclic analog of 7-deazaisoguanosine and its triphosphate.
Drawing 19. FIG. 13C . Synthesis of tricyclic analog of 7-deazaisoguanosine and its triphosphate.
DESCRIPTION OF THE INVENTION
A central teaching of this disclosure is that hydrogen-bonding pattern designated using this systematic nomenclature is distinct, in concept, from the organic molecule that is used to implement the hydrogen-bonding pattern. Which organic molecule is chosen to implement a specific hydrogen-bonding pattern determines, in large part, the utility of the non-standard hydrogen-bonding pattern, in various applications to which it might be applied.
Thus, guanosine is a nucleoside that implements the puADD hydrogen-bonding pattern. So does, however, 7-deazaguanosine, 3-deazaguanosine, 3,7-dideazaguanosine, and any of any number of other purines and purine derivatives, including those that carry side chains to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups.
Likewise, isoguanosine is a nucleoside that implements the puDDA hydrogen-bonding pattern. So does, however, 7-deazaisoguanosine, 3-deazaisoguanosine, 3,7-dideazaisoguanosine, and any of any number of other purines and purine derivatives, including those that carry side chains to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups, on the exocyclic amino group or at position 7.
Likewise, xanthine is a nucleobase that implements the puADA hydrogen-bonding pattern. So does, however, imidazo[1,2-a]-1,3,5-triazine-2(8H)-4(3H)-dione, and any of any number of other purines and purine derivatives, including those that carry side chains to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups.
The presently preferred embodiments of the instant invention with respect to eight non-standard nucleotides, which form four base pairs, is now presented, with reference (and/or cross-reference) to systematic nomenclature. Numbering is based on the deoxyribonucleoside analog.
For the pyDAD hydrogen bonding pattern (“py” indicates that the heterocycle is a pyrimidine analog; contrast with “pu”, which indicates a purine analog), the presently preferred embodiment is 2,4-diamino-5-(1′-beta-D-2′-deoxyribofuranosyl)-pyrimidine, also named (1R)-1,4-anhydro-2-deoxy-1-C-(2,4-diamino-5-pyrimidinyl)-D-erythropentitol, or the 2,6-diamino-3-nitro-5-(1′-beta-D-2′-deoxyribofuranosyl)-pyridine.
For the puADA hydrogen bonding pattern, the presently preferred embodiment is 8-(β-D-2′-deoxyribofuranosyl)imidazo[1,2-a]-1,3,5-triazine-2(8H)-4(3H)-dione, including those that carry side chains attached to “C7”, including those to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups.
For the pyAAD hydrogen bonding pattern, the presently preferred embodiment is 2′-deoxy-5-methylisocytidine (2-amino-5-methyl-1-(1′-beta-D-2′-deoxyribofuranosyl)-4(1H)-pyrimidinone) or 2-deoxy-N-methyl-pseudocytidine.
For the puDDA hydrogen bonding pattern, the presently preferred embodiment is 6-amino-1,9-dihydro-9-(1′-beta-D-2′-deoxyribofuranosyl)-3H-7-deazapurin-2-one, including those that carry side chains attached to the exocyclic amino group or to “C7”, including those to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups.
For the pyDDA hydrogen bonding pattern, the presently preferred embodiment is 6-amino-3-(2′-deoxy)-D-ribofuranosyl)-5-nitro-1H-pyridin-2-one.
For the puAAD hydrogen bonding pattern, the presently preferred embodiment is 7-amino-9-(1′-beta-D-2′-deoxyribofuranosyl)-imidazo[1,2-c]-pyrimidin-5(1H)-one, including those that carry side chains attached to “C7”, including those to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups.
For the pyADD hydrogen bonding pattern, the presently preferred embodiment is 2-amino-3-(2′-deoxy)-D-ribofuranosyl)-5-nitro-1H-pyridin-6-one.
For the puDAA hydrogen bonding pattern, the presently preferred embodiment is 4-amino-8-(1′-beta-D-2′-deoxyribofuranosyl)-imidazo[1,2-a]-1,3,5-triazin-2(8H)-one, including those that carry side chains attached to the exocyclic amino group or to “C7”, including those to which are appended functional groups, such as fluorescent, fluorescent quencher, attachment, or metal complexing groups.
To practice the invention, standard PCR is performed to increase the number of copies (to “amplify”) of a starting oligonucleotide. PCR is performed with a thermostable polymerase, which is defined as a polymerase that is stable at temperatures up to at least 80° C., and at temperatures that allow duplex DNA to be separated. Several of the preferred polymerases, matched to preferred AEGIS components, are described in the Examples, which include standard thermostable polymerases from evolutionary Family A (e.g. Taq DNA polymerase from Family A) and from Family B (e.g. Deep Vent polymerase). These include mutant forms of various thermostable polymerases, some disclosed in the Examples, which also represent inventions.
The PCR requires dissolving the oligonucleotide to be amplified in an aqueous mixture containing a thermostable DNA polymerase in a buffer where the polymerase functions, as is known in the art. The aqueous mixture must also contain nucleoside triphosphates that are Watson-Crick complementary to all of the nucleotides in the oligonucleotide to be amplified. “Watson Crick complementary” is a term of art that requires the heterocycles in the triphosphate to be size- and hydrogen bonding-complementary, as outlined above.
The PCR mixture also must contain a first oligonucleotide primer that is “substantially complementary” to a segment at or near the 3′-end of the oligonucleotide to be amplified. “Substantially complementary” is a term of art that includes the possibility that the primer:oligonucleotide complex has a small number of mismatches; the level of mismatching must not, however, be so large as to prevent the hybridization of the primer to the oligonucleotide to be amplified. This hybridization is achieved by annealing of the primer and the oligonucleotide by lowering the temperature of the mixture, typically starting at a temperature above 80° C. where duplexes are unstable, at an appropriate rate, as is well known in the art, to a temperature where the hybrid is substantially stable.
The first extension in the PCR arises by incubating the mixture of primer, oligonucleotide, polymerase, and triphosphates at a temperature where the polymerase extends the first oligonucleotide primer to give an extension product that is substantially complementary to the oligonucleotide. In the initial product, the extension product forms a duplex with said oligonucleotide. Further, the extension product, when it is separated from said oligonucleotide, can hybridize to a second oligonucleotide primer, which that a sequence substantially identical to a portion of said oligonucleotide at or near its 5′-end, and is therefore substantially complementary to the extension product at its 3′-end. This primer extension time is variable, as is known in the art, but preferably is between 30 seconds and three minutes.
For the process to continue, the temperature of the mixture is then increased to a temperature sufficient to separate the initial oligonucleotide from its extension product. This gives both primers a chance to bind upon subsequent annealing, the first primer to the original oligonucleotide, the second to the extension product. This temperature is generally above 80° C. The annealing is then achieved by lowering the temperature of the mixture to a temperature at which the primers can hybridize. Typically, the temperature is then adjusted to a temperature optimal for the polymerase to extend all primer-template complexes.
These steps are repeated an arbitrary number of times, but generally at least five times. The extent of amplification depends on the ratio of primers to original oligonucleotide. As is known in the art, unequal amounts of the two primers give “asymmetric PCR”.
EXAMPLES
Example 1
PCR Amplification of the Diaminopurine (K):5-aza-7-deazaxanthine (X) Pair
Variants of the DNA polymerase 1 from Thermus aquaticus that incorporate the K:X nucleobase pair were obtained by screening a large library of variants constructed by analyzing heterotachy within the protein family. After screening, 23 of the most active clones were selected to do a PCR with a reduced optimal extension time (reduced from 2:10 to 1:10) that incorporated the nucleobase pair between diaminopyrimidine (here, abbreviated as K) and 5-aza-7-deazaxanthosine (here, abbreviated as X). Plasmids encoding the variants were then prepped from cultures expressing the polymerase variants having higher activity (judged from the amount of PCR product). Five of these polymerases were partially sequenced to identify their mutations.
FIG. 3 shows data identifying polymerases that perform in the instant process. The polymerases replace the aspartic acid at position 548 by a glycine, the arginine at position 657 by a glycine, the aspartic acid at position 548 by a leucine, the aspartic acid at position 548 by a glycine, and the arginine at position 657 by a glycine. This numbering differs by −3 amino acids from standard numbering. Thus, the 657 site hold the arginine at site 660 (in standard numbering) in the O-helix. This helix also contains Arg 659 and Lys 663, which are known to interact with the incoming triphosphate moiety and are critical for enzymatic activity.
TABLE 1
Taq variants found after screening.
Variant
Standard numbering
Distance to aspartate 785 (Å)
D548G
551
293
D548L
551
29.5
R657G
660
14.1
The primers were designed so that successful amplification required both dKTP to be incorporated opposite template X and dXTP to be incorporated opposite template K.
Fwd-K-17
SEQ ID NO 1
5′-CTAKGACKACGKACTKC-3′
Rev-X-17
SEQ ID NO 2
5′C-AGXAAGXAGCXATCXC-3′
Fwd K-59
SEQ ID NO 3
5′-CTAKGACKACGKACTKCCACCAGGAAGCAGCCATCACACACAGTGCGC
ATCCTGACTGC-3′
Rev X-60
SEQ ID NO 4
5′CAGXAAGXAGCXATCXCCACCAGGAAGCAGCCATCACACACCCAAGGGG
TTATGCTAGGG-3′
To perform the PCR, 25 million cells expressing the Taq polymerase variant were suspended in 30 μL of master mix and placed on the thermocycler on the following program: 94° C. for 2:0 min, then 30 cycles at [94° C. for 30 sec 57° C. for 30 sec 72° C. for 1.17 min], finally 72° C. for 10:00 min, in a thermocycler. The PCR used this master mix:
component
concentration
Volume (μL)
10X Thermo
10X
80
pol pH 8.8
Fwd K59
0.2
uM
80
Rev X60
0.2
uM
80
Fwd K17
2
uM
80
Rev X17
2
uM
80
dNTPs
2
mM
80
dXTP
2
mM
16
dKTP
2
mM
16
water
288
Example 2
PCR Amplification of the 5-methylisocytosine Analogs and Isoguanine Analogs
Johnson et al. [2004] lost isocytosine and isoguanosine in the art PCR. Accordingly, new nucleobases carrying heterocycles that implement the same hydrogen bonding patterns, but not suffering from the defects of the species known in the art, were examined. Instead of 2′-deoxyisocytidine, the PCR amplifications of the instant invention used 2′-deoxy-5-methylisocytidine and 2′-deoxy-5-methylpseudocytidine [Kim, H. J., Leal, N. A., Benner, S. A. (2009) 2′-Deoxy-1-methylpseudocytidine. A stable analog of 2′-deoxy-5-methylisocytidine. Bioorg. Med Chem. 17, 3728-3732]. Instead of 2′-deoxy-isoguanosine, the PCR amplifications of the instant invention used 2′-deoxy-7-deazaisoguanosine and a cyclic version of 2′-deoxy-7-deazaisoG. Here, fidelity studies used a 32 P-radiolabeled primer to monitor the incorporation of AEGIS triphosphates opposite isoC and psuedoC in a template. In these experiments, the template contains a BglII restriction site which cuts at 5′-A↓GATCT. That site is disrupted by a nucleotide analog that implements the pyAAD and/or puDDA hydrogen bonding pattern. Replacement of the AEGIS pair by an A:T pair restores the restriction site. Analysis of the PCR products therefore allows the measurement of the fidelity of the PCR. Also, a control template containing the BglII site with standard dNTPs was tested in PCRs. This analysis assumes:
1. A restriction enzyme that recognizes the T:A pair will not recognize a pair between an analog of isoC:isoG. 2. Loss of an isoC:isoG analog pair gives only T:A, and never C:G, G:C, or A:T.
To approximate various cycles, various dilutions of template were used with the following modifications:
1) Amplify using primers and dNTPs 2) Amplify using primers, dNTPs, disoCTP and disoGTP 3) Amplify using primers, dNTPs, pseudoCTP and d7deazaisoGTP 4) Amplify using primers, dNTPs, pseudoCTP and cyclic d7deazaisoGTP
As shown in the figures, PCRs generated full length products as 60 mers. After dilution of the template in 10-fold increments starting at 10 10 molecules to 10 7 molecules and 30 rounds of PCR, PCR products were digested with BglII. Also, products containing 5′-methylisoC were treated with acid to cleave the oligonucleotide at the site containing the isoC analog, neutralized and resolved on 16% PAGE. As the pair is replaced by T:A, the amount of acid hydrolyzed product decreases, while the amount of BglII digested product increases.
Olignucleotides Used:
tauto T BgIIIXhol (60 nt)
SEQ ID NO 5
5′-GCG TAA TAC GAC TCA CTA TAG ACG AGC T AG ATC T CG
AGT CTT TAG TGA GGG TTA ATT CGC
tauto iC BgIIIXhoI
SEQ ID NO 6
5′-GCG TAA TAC GAC TCA CTA TAG ACG AGC
T AG ATC MeisoC CG AGT CTT TAG TGA GGG TTA ATT CGC
tauto S BelIIXhoI
SEQ ID NO 7
5′-GCG TAA TAC GAC TCA CTA TAG ACG AGC
T AG ATC pseudoC CG AGT CTT TAG TGA GGG TTA ATT CGC
Forward primer (21 nt) nal P-2f
SEQ ID NO 8
32P-5′-GCG TAA TAC GAC TCA CTA TAG
Reverse primer (21 nt) nal P-2r
SEQ ID NO 9
5′-GCG AAT TAA CCC TCA CTA AAG
TABLE 1 Amounts of full length product, BglII digested and acid hydrolyzed product from PCRs seen in FIG. 1 were quantified Template 1 Theoretical 3 Volume % digested molecules rounds (n) (CNT * mm 2 ) or cleaved Template T 6 × 10 10 3.32 2 FLP 13206 90 dNTPs BglII digested 117735 6 × 10 9 6.64 FLP 4580 96 BglII digested 122357 6 × 10 8 9.97 FLP 12716 90 BglII digested 111817 6 × 10 7 13.29 FLP 1292 98 BglII digested 69162 Template isoC 6 × 10 10 3.32 FLP 17973 83 RE isoC/isoG BglII digested 85099 FLP 46965 22 cleaved 12968 6 × 10 9 6.64 FLP 29232 77 BglII digested 99881 FLP 63661 10 cleaved 7016 6 × 10 8 9.97 FLP 16857 85 BglII digested 99100 FLP 62763 4 cleaved 2730 6 × 10 7 13.29 FLP 2343 96 BglII digested 54607 FLP 24942 4 cleaved 907
PCR, Acid Hydrolysis and Restriction Digestion Conditions
PCRs contained, in a 50 μL reaction volume, forward (32P-labeled) and reverse primers (1 pmol each; 6×10 11 molecules), various concentrations of template (10-fold dilutions of 10 10 molecules to 10 7 molecules), 10 mM bis-tris-propane-HCl, 40 mM potassium acetate, 2 mM MgCl 2 , 0.1 mg/mL bovine serum albumin, 100 μM of appropriate triphosphates and titanium Taq (1×, Clontech). PCR cycles included an initial denaturation of 2 min 95° C. to activate the hot-start enzyme. Reactions were cycled (30 rounds) at 95° C. 45 sec, 45° C. for 40 sec and 72° C. for 1.5 min. Following PCR, isoG/isoC reactions were treated with an equal volume of 0.1 M acetic acid and incubated at 95° C. for 30 min, tubes were opened and volatiles were allowed to evaporate for 1 min at 95° C. Reactions were cooled on ice, then two volumes of ammonium hydroxide (0.1 M) were added and incubated at 95° C. for 5 min. The ammonium hydroxide was then allowed to evaporate and the mixtures were quenched by the addition of gel loading buffer (10 mM EDTA, 1 mg/mL bromophenol blue, 1 mg/mL xylene cyanol FF, 98% formamide). An aliquot of all the PCRs were digested with BglII (5 units) in NEBuffer 3.1 for 2 hours at 37° C., reactions were quenched by the addition of gel loading buffer and all samples were analyzed by denaturing PAGE (16%). Results are summarized in FIGS. 4-6 and Tables 1-3.
TABLE 2
Volume of full length product, BglII digested and acid
hydrolyzed product from PCRs seen in FIG. 2 were quantified
Template
1 Theoretical
3 Volume
% digested
molecules
rounds (n)
(CNT * mm 2 )
or cleaved
Template
6 × 10 10
3.32
2 FLP
15704
84
isoC
BglII digested
80552
isoC/isoG
FLP
45139
20
cleaved
11314
6 × 10 9
6.64
FLP
26608
76
BglII digested
85676
FLP
59979
9
cleaved
5895
6 × 10 8
9.97
FLP
15103
86
BglII digested
91069
FLP
58601
4
cleaved
2522
6 × 10 7
13.29
FLP
1939
96
BglII digested
46684
FLP
23846
4
cleaved
1016
Template
6 × 10 10
3.32
FLP
62103
46
pseudoC
BglII digested
53115
pseudoC/7-
6 × 10 9
6.64
FLP
23071
80
deazaisoG
BgIII digested
95107
6 × 10 8
9.97
FLP
7048
94
BglII digested
102723
6 × 10 7
13.29
FLP
943
98
BglII digested
44840
TABLE 3
Amounts of full-length product, BglII digested and acid
hydrolyzed product from PCRs seen in FIG. 3 were quantified
Template
1 Theoretical
3 Volume
% digested
molecules
rounds (n)
(CNT * mm 2 )
or cleaved
Template
6 × 10 1
3.32
2 FLP
23223
80
isoC
BglII digested
95848
isoC/isoG
FLP
56884
23
cleaved
16649
6 × 10 9
6.64
FLP
33775
76
BglII digested
105889
FLP
72517
11
cleaved
9082
6 × 10 8
9.97
FLP
20336
85
BglII digested
112120
FLP
68412
7
cleaved
4783
6 × 10 7
13.29
FLP
4299
92
BglII digested
51836
FLP
31101
7
cleaved
2401
Template
6 × 10 10
3.32
FLP
95674
34
pseudoC
BglII digested
49236
pseudoC/
6 × 10 9
6.64
FLP
60572
57
cyclic
BgIII digested
80051
7-deazaisoG
6 × 10 8
9.97
FLP
48010
66
BglII digested
91204
6 × 10 7
13.29
FLP
14588
71
BglII digested
35225
Example 3
PCR Amplification of Oligonucleotides Containing the Pair Between 6-amino-5-nitro-3-(1′-β-D-2′-deoxyribo-furanosyl)-2(1H)-pyridone and 2-amino-8-(1′-β-D-2′-deoxyribofuranosyl)-imidazo[1,2-a]-1,3,5-triazin-4(8H)-one (the Z:P Pair)
Various polymerases were challenged to incorporate consecutive non-standard nucleotides opposite consecutive non-standard Z and P components in 1× Thermopol reaction buffer (for Taq and Deep Vent (exo + ), pH 8.0, measured at room temperature) or 1× Phusion HF buffer (for Phusion at pH ca. 8.3) at 72° C. for the times indicated on the gels (1 to 16 min). Note: the failure of the polymerase to generate full length products in the absence of dZTP and/or dPTP is evidence that no substantial amounts of standard nucleotides are incorporated opposite non-standard template nucleotides.
Negative control (−): dNTPs (each 0.1 mM).
Positive control (+): dNTPs (each 0.1 mM) and dZTP (0.1 mM, left) or dPTP (0.1 mM, right).
(a) Results from two consecutive non-standard nucleotides with Deep Vent (exo + ) DNA polymerase ( FIG. 7 ).
(b) Results from three consecutive non-standard nucleotides with Taq, Deep Vent (exo + ) and Phusion DNA polymerases ( FIG. 8 )
(c) Results from four consecutive non-standard nucleotides with Taq, Deep Vent (exo + ) and Phusion DNA polymerase ( FIG. 9 ).
Primer-F1: SEQ ID NO 10 3′-GAAAT*CACTCCCAATTAAGCG-5′ 2P-Temp: SEQ ID NO 11 5′-GCGTAATACGACTCACTATAGACGA PP CTA CTTTAGTGAGGGTTAATT CGC -3′ 2Z-Temp: SEQ ID NO 12 3′- CGCATTATGCTGAGTGATATC TGCT ZZ GATGAAATCACTCCCAATTAA GCG-5′ Primer-R1: SEQ ID NO 13 5′-GCGTAATACGACTCAC*TATAG-3′ Primer-F1: SEQ ID NO 14 3′-GAAAT*CACTCCCAATTAAGCG-5′ 3P-Temp: SEQ ID NO 15 5′ GCGTAATACGACTCACTATAGACACT PPP TACTCA CTTTAGTGAGGGT TAATTCGC -3′ 3Z-Temp: SEQ ID NO 16 3′- CGCATTATGCTGAGTGATATC TGTGA ZZZ ATGAGTGAAATCACTCCCA ATTAAGCG-5′ Primer-R1: SEQ ID NO 17 5′-GCGTAATACGACTCAC*TATAG-3′ Primer-F1: SEQ ID NO 18 3′-GAAAT*CACTCCCAATTAAGCG-5′ 4P-Temp: SEQ ID NO 19 5′-GCGTAATACGACTCACTATAGACACT PPPP TACTCA CTTTAGTGAGGG TTAATTCGC -3′ 4Z-Temp: SEQ ID NO 20 3′- CGCATTATGCTGAGTGATATC TGTGA ZZZZ ATGAGTGAAATCACTCCC AATTAAGCG-5′ Primer-R1: SEQ ID NO 21 5′-GCGTAATACGACTCAC*TATAG-3′
Polymerase Extension that Reads Through Multiple Consecutive Non-Standard Nucleobases
5′- 32 P-Labeled primer (Primer-F1 or Primer-R1, 0.2 pmole of hot primer plus 4 pmole of cold primer, final concentration 70 nM) was annealed to a template containing multiple consecutive non-standard nucleobases (P or Z, 6 pmole, final concentration 100 nM) in 1× ThermoPol polymerase reaction buffer (pH=8.0 at room temperature) or 1× HF Phusion buffer (pH=8.3 at room temperature) by heating at 96° C. for 5 min and then slow cooling (0.5 h) to room temperature. dNTPs (final 0.1 mM for each) or both dNTPs and dZ(P)TP (final 0.1 mM for each) were added at room temperature. The reaction mixture was pre-heated at 72° C. for 30 seconds. Extension was initiated by adding Taq (2.5 units), Deep Vent (exo + , 1 unit for Figure S1 (a) right panel and 2 units for the rest of Figure S1), or Phusion (1 unit) DNA polymerase to give a final volume of 60 μl. The primer was extended at 72° C. and aliquots (7 μl) were taken from each reaction at time intervals (1, 2, 4, 8, and 16 min), quenched by PAGE loading/quench buffer (10 μL, 10 mM EDTA in formamide). Samples were resolved by electrophoresis using a 16% PAGE (7 M urea). The gel was analyzed using MolecularImager software ( FIGS. 7-9 ).
Measuring the Retention and Mutation of Z:P Pair in Optimized Six-Letter PCR
In 1× ThermoPol reaction buffer (pH 8.0 measured at 25° C.), synthetic template (Bsp-P, Table 1) or standard template (Bsp-G, Table 1) was amplified (1000 to 100000 fold, respectively) using JumpStart Taq DNA polymerse (0.08 unit/μl, Sigma) with primers (Primer-F3 and Primer-R3) and dZTP=0.05 mM, dPTP=0.6 mM, dA,T,G/TPs=0.1 mM, dCTP=0.2 mM, or 0.4 mM, or 0.6 mM. The PCR mixture were cycled using the following conditions: one cycle of 95° C. for 1 min; followed by 31 cycles of (95° C. for 30 s, 55° C. for 30 s, 72° C. for 1 min); and finally 72° C. for 10 min. Upon the completion of PCR amplification, 1 μl of PCR mixture was digested with BsP120I (0.5 μl, final 0.5 units/μl) in 1× Buffer B at 37° C. for 20 hours (10 μl of reaction volume). Additional 0.5 μl of Bsp120I was added to the digestion mixture and incubated for another 20 hours. The digestion products were resolved on 10% PAGE gel (7 M urea) and visualized by autoradiography.
PCR Amplification of the GACTZP DNA and Sequencing of the PCR Products
Synthetic GACTZP DNA containing various numbers of Z and P nucleotides incorporated at various positions, adjacent and spaced apart (final 0.04 nM of each) were amplified in 1× ThermoPol reaction buffer (pH=8.0, measured at room temperature) containing primers (0.4 μM each of Primer-F1 and Primer-R1, or Primer-F2 and Primer-R2, or Primer-F3 and Primer-R3), dA,T,G/TPs (each 0.1 mM), dCTP (0.2 mM), dZTP (0.05 mM), dPTP (0.6 mM), and 0.05 unit/μl of JumpStart Taq DNA polymerase in a total volume of 50 μl. The following PCR conditions were used: one cycle of 95° C. for 1 min; followed by 21 cycles of (95° C. for 20 s, 58° C. for 25 s, 72° C. for 3 min); and finally 72° C. for 10 min. Upon the completion of the PCR, samples (10 μl) were taken from each PCR mixture, mixed with 6× agarose loading dye (2 μl, Promega), and analyzed on agarose gel.
A sample (20 μl) of PCR mixture taken from the above PCR was mixed with 8 μl of ExoSAP-IT (USB, Cleveland, Ohio) and incubated at 37° C. for 30 min to degrade remaining primers and nucleotides, then, incubated at 80° C. for 15 min. The mixture was purified by Qiaquick Nucleotide Remove Kit (Qiagen, Valencia, Calif.). The GACTZP DNA was eluted from the spin column using EB buffer (200 μl, 10 mM TrisCl, pH 8.5).
Example 4
PCR Amplification of GACTZP DNA (FIG. 10 )
Under the optimized triphosphate concentrations, the retention rate of Z:P pair and the forward mutation (gain of Z:P pair) in the recognition sequence per theoretical PCR cycle for dCTP=0.2 mM (Left panel) are ca. 99.83% and 0.37%, for dCTP=0.4 mM (Middle panel) are ca. 99.83% and 0.25%, for dCTP=0.6 mM (Right panel) are ca. 99.80% and 0.20%. The following oligonucleotides were used:
Oligonucleotides Used in Six-Letter GACTZP PCR
Primer-F1:
SEQ ID NO 22
3′- GAAATCACTCCCAATTAAGCG -5′
2G-Temp:
SEQ ID NO 23
5′- GCGTAATACGACTCACTATAG ACGA GG CTA CTTTAGTGAGGGTTAATT
CGC -3′
1P-Temp:
SEQ ID NO 24
5′- GCGTAATACGACTCACTATAG ACGA P CGTA CTTTAGTGAGGGTTAATT
CGC -3′
2P-Temp:
SEQ ID NO 25
5′- GCGTAATACGACTCACTATAG ACGA PP CTA CTTTAGTGAGGGTTAATT
CGC -3′
3P-Temp:
SEQ ID NO 26
5′- GCGTAATACGACTCACTATAG ACACT PPP TACTCA CTTTAGTGAGGGT
TAATTCGC -3′
4P-Temp:
SEQ ID NO 27
5′- GCGTAATACGACTCACTATAG ACACT PPPP TACTCA CTTTAGTGAGGG
TTAATTCGC -3′
4G-Temp:
SEQ ID NO 28
5′- GCGTAATACGACTCACTATAG ACACT GGGG TACTCA CTTTAGTGAGGG
TTAATTCGC -3′
2C-Temp:
SEQ ID NO 29
3′- CGCATTATGCTGAGTGATATC TGCTCCGAT GAAATCACTCCCAATTAA
GCG -5′
1Z-Temp:
SEQ ID NO 30
3′- CGCATTATGCTGAGTGATATC TGCT Z GCAT GAAATCACTCCCAATTAA
GCG -5′
2Z-Temp:
SEQ ID NO 31
3′- CGCATTATGCTGAGTGATATC TGCT ZZ GAT GAAATCACTCCCAATTAA
GCG -5′
3Z-Temp:
SEQ ID NO 32
3′- CGCATTATGCTGAGTGATATC TGTGA ZZZ ATGAGT GAAATCACTCCCA
ATTAAGCG -5′
4Z-Temp:
SEQ ID NO 33
3′- CGCATTATGCTGAGTGATATC TGTGA ZZZZ ATGAGT GAAATCACTCCC
AATTAAGCG -5′
4C-Temp:
SEQ ID NO 34
3′- CGCATTATGCTGAGTGATATC TGTGA CCCC ATGAGT GAAATCACTCCC
AATTAAGCG -5′
Primer-R1:
SEQ ID NO 35
5′- GCGTAATACGACTCACTATAG -3′
Primer-F2:
SEQ ID NO 36
3′- CAGTATCGACAAAGGACACACGCT -5′
Z2-2P:
SEQ ID NO 37
5′- GACACTAGTAGCACTCACTATACG TGACTC P TCAC ZZ AGTGC P ACTAC
G GTCATAGCTGTTTCCTGTGTGCGA -3′
PP-2Z:
SEQ ID NO 38
3′- CTGTGATCATCGTGAGTGATATGC ACTGAG Z AGTG PP TCACG Z TGATG
C CAGTATCGACAAAGGACACACGCT -5′
Primer-R2:
SEQ ID NO 39
5′- GACACTAGTAGCACTCACTATACG -3′
Primer-F3:
SEQ ID NO 40
3′-TATGCAACGCTAGCGAGGAAGGAC-5′
Bsp-Z:
SEQ ID NO 41
5′- CTAGGACGACGGACTGCCTATGAG AGACATGA GGGCC Z GGTACCATCG
ATACGTTGCGATCGCTCCTTCCTG -3′
Bsp-P:
SEQ ID NO 42
3′- GATCCTGCTGCCTGACGGATACTC TCTGTACT CCCGG P CCATGGTAGC
TATGCAACGCTAGCGAGGAAGGAC -5′
Bsp-C:
SEQ ID NO 43
5′- CTAGGACGACGGACTGCCTATGAG AGACATGA GGGCC C GGTACCATCG
ATACGTTGCGATCGCTCCTTCCTG -3′
Bsp-G:
SEQ ID NO 44
3′- GATCCTGCTGCCTGACGGATACTC TCTGTACT CCCGG G CCATGGTAGC
TATGCAACGCTAGCGAGGAAGGAC -5′
Primer-R3:
SEQ ID NO 45
5′-CTAGGACGACGGACTGCCTATGAG-3'
Example 5
RNA Synthesis (FIG. 12 )
Transcription templates were annealed by independently combining equimolar ratios of appropriate top strand and bottom strands of tDNA templates (01-07, respectively) in 1× transcription buffer (20 mM NaCl, 40 mM Tris pH 7.8, 6 mM MgCl 2 , 2 mM spermidine, and 10 mM DTT), heating to 85° C. and then cooling to room temperature.
Seven different transcription reactions contained a final concentration of 0.25 μg template DNA (01-07, respectively), in transcription buffer (20 mM NaCl, 40 mM Tris pH 7.8, 16 mM MgCl2, 2 mM Spermidine, and 10 mM DTT), T7 RNA polymerase (4 Unit/μL final) and 2 mM each rNTP. Transcriptions were incubated at 37° C. for 16 hours and were quenched with 3-fold formamide quench buffer. Samples were resolved on a 3% agarose gel ( FIG. 12 ). Small scale transcription reactions using the DNA templates yielded RNA of the appropriate size. The following DNA template sequences were used:
SEQ ID NO 46
5′- GGCGTAATACGACTCACTATA GGCTCTGTAGTTCAGTCGGTAGAACGG
CGGActTCCAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 47
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAAGGTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT-
5′
SEQ ID NO 48
5′- GGCGTAATACGACTCACTATA GGCTCTGTAGTTCAGTCGGTAGAACGG
CGGACTPCCAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 49
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAZGGTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT-
5′
SEQ ID NO 50
5′- GGCGTAATACGACTCACTATA GGCTCTGTAGTTCAGTCGGTAGAACGG
CGGACTTPCAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 51
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAAZGTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT-
5′
SEQ ID NO 52
5′- GGCGTAATACGACTCACTATA GGCTCTOTAGTTCAGTCGGTAGAACGG
CGGACTTCPAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 53
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAAGZTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT-
5′
SEQ ID NO 54
5′- GGCGTAATACGACTCACTATA GGCTCTGTAGTTCAGTCGGTAGAACGG
CGGACTZCCAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 55
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAPGGTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT-
5′
SEQ ID NO 56
5′- GGCGTAATACGACTCACTATA GGCTCTGTAGTTCAGTCGGTAGAACGG
CGGACTTZCAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 57
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAAPGTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT-
5′
SEQ ID NO 58
5′- GGCGTAATACGACTCACTATA GGCTCTGTAGTTCAGTCGGTAGAACGG
CGGACTTCZAATCCGTATGTCACTGGTTCGAGTCCAGTCAGAGCCGCCA
SEQ ID NO 59
3′-CCGCATTATGCTGAGTGATATCCGAGACATCAAGTCAGCCATCTTGCC
GCCTGAAGPTTAGGCATACAGTGACCAAGCTCAGGTCAGTCTCGGCGGT
01:
SEQ ID NO 60
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU UCC AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
02:
SEQ ID NO 61
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU PCC AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
03:
SEQ ID NO 62
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU UPC AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
04:
SEQ ID NO 63
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU UCP AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
05:
SEQ ID NO 64
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU ZCC AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
06:
SEQ ID NO 65
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU UZC AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
07:
SEQ ID NO 66
5′-GGCUCUGUAGUUCAGUCGGUAGAACGGCGGACU UCZ AAUCCGUAUGUC
ACUGGUUCGAGUCCAGUCAGAGCCGCCA-3′
Example 6
Synthesis of Tricyclic Analog of 7-deazaisoguanosine and its Triphosphate (FIG. 12 )
2-Amino-3,7-dihydro-pyrrolo[2,3-d]pyrimidin-4-one (2).
2,4-Diamino-6-hydroxypyrimidine (25.2 g, 200 mmol) was dissolved in DMF (480 mL) and water (80 mL) at room temperature. Sodium acetate (16.6 g, 200 mmol) was added to this solution and the resulting yellow solution was stirred for 1 h. Chloroacetaldehyde (25.3 mL, 200 mmol) was added, and the mixture was stirred for 46 h at room temperature. The reaction mixture was then concentrated by rotary evaporation. The product was triturated with water (20 mL) and recovered by filtration. The filtered solid was digested in refluxing methanol (500 mL) for 2 h, and the mixture was then placed in a refrigerator at 4° C. overnight to yield a product as a precipitate, which was recovered by filtration, washed with EtOAc (4×250 mL) and dried in a vacuum desiccator over P 2 O 5 (20 g, 133 mmol, 66% yield).
1 H NMR (300 MHz, DMSO-d6) ppm 11 (s, 1H), 10.35 (s, 1H), 6.6 (s, 1H), 6.15 (s, 1H), 6.09 (s, 2H)
N-(4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-2-yl)pivalamide (3).
A solution of 2-amino-3,7-dihydro-pyrrolo[2,3-d]pyrimidin-4-one (25 g, 166.66 mmol) in pyridine (300 mL) was treated with trimethylacetyl chloride (65.74 mL, 533 mmol) at 90° C. for 2 h, to give a mixture of N(2)-monoacylated and N(2), N(7)-bisacylated material. The solvent was evaporated and the residue was taken up in aqueous ammonia (28% NH 3 , 42 mL) and MeOH (300 mL), and stirred at room temperature for 30 min, to selectively cleave the N(7)-pivaloyl group. The product precipitates, and the solid was collected by filtration, washed with cold MeOH, and dried on high vacuum (16 g, 68 mmol, 41% yield).
1 H NMR (300 MHz, DMSO-d6) ppm 11.82 (s, 1H), 11.58 (s, 1H), 10.8 (s., 1H), 6.9 (d, J=3.4 Hz, 1H), 6.38 (d, J=3.6 Hz, 1H), 1.2 (s, 9H)
N-(4-chloro-7H-pyrrolo[2,3-d]pyrimidin-2-yl)pivalamide (4).
A mixture of N-(4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-2-yl) pivalamide (11 g, 47 mmol), POCl 3 (26 mL, 282 mmol), benzyltriethylammonium chloride (21.4 g, 94 mmol), N,N-dimethylaniline (12 mL, 94 mmol), and acetonitrile (104 mL) was heated at reflux for 1 h. The volatiles were removed by rotary evaporation, and the residual oil was slowly added to 800 mL of ice-water (which destroys the remaining POCl 3 ). The pH was adjusted to 4 by dropwise addition of 28% aqueous NH 4 OH to generate product as a precipitate, which was collected by filtration, washed with cold water, and purified by silica chromatography (30% ethyl acetate/hexane) to give purified product as a white solid (7 g, 0.27 mol, 58% yield).
1 H NMR (300 MHz, DMSO-d6) ppm 12.33 (br. s., 1H), 10.04 (s, 1H), 7.52 (d, J=3.57 Hz, 1H), 6.50 (d, J=3.43 Hz, 1H), 1.20 (s, 9H)
4-Chloro-5-iodo-2-pivaloylamino-7H-pyrrolo[2,3-d]pyrimidine (5)
A solution of compound 4 (5.0 g, 19.84 mmol) and N-Iodosuccinimide (5.35 g, 23.8 mmol) in CH 2 Cl 2 (100 mL) was stirred at 40° C. for 5 h. The yellow solution was evaporated to an amber residue which was crystallized from MeOH to give yellowish crystals (3.5 g).
1 H NMR (300 MHz, DMSO-d6) ppm 1.22 (s, 9H), 7.77 (s, 1H), 10.13 (s, 1H), 12.71 (s, 1H).
4-Chloro-7[-2-deoxy-3,5-di-O-(p-toluoyl)-b-D-erythro-pentofuranosyl]-5-iodo-2-pivaloylamino-7H-pyrrolo[2,3-d]pyrimidine (6)
To a suspension of NaH (60% emulsion in oil, 0.767 g, 17.8 mmol) in dry acetonitrile (400 mL) was added 5 (6.7 g, 17.7 mmol) at room temperature. After incubation for 1 h, 2-deoxy-3,5-di-O-(p-toluoyl)-□-D-erythro-pentofuranosyl chloride (12.1 g, 22.6 mmol) was added to the reaction mixture, which was stirred further for 16 h. The product (5 g) was obtained as a white solid after removal of the solvent on a rotary evaporator and purification by silica gel chromatography (EtOAc/hexanes 1:4).
1 H NMR (300 MHz, DMSO-d6) ppm 1.21 (s, 9H), 2.37, 2.39 (2 s, 6H), 2.69-2.75 (m, 1H), 3.19-3.25 (m, 1H), 4.47-4.53 (m, 2H), 4.61-4.67 (m, 1H), 5.77-5.79 (m, 1H), 6.63 (t, 1H, J=6.8 Hz), 7.31, 7.37, 7.84, 7.94 (4 d, 8H, J=8.1 Hz), 7.99 (s, 1H), 10.29 (s, 1H).
7-(2-Deoxy-b-D-erythro-pentofuranosyl)-5-iodo-7H-pyrrolo-[2,3-d]pyrimidine-2,4-diamine (7)
A suspension of compound 6 (3 g, 4.1 mmol) in dioxane (60 mL) and 25% NH 3 /H 2 O (160 mL) was introduced into an stainless steel pressure bomb and stirred at 120° C. for 24 h. The clear solution was evaporated and the residue was subjected to flash chromatography (silica gel, column, EtOAc:MeOH:H 2 O, 80:17:3). The main zone was collected and rotavap to a brown color solid of 2 (3 g, 94%). [Seela, F Synthesis 2004, 8, 1203-1210]
1 H NMR (300 MHz, DMSO-d6) ppm 7.40 (br. s., 2H), 7.01 (d, J=3.6 Hz, 1H), 6.22-6.38 (m, 3H), 5.22 (d, J=2.9 Hz, 1H), 4.27 (br. s., 1H), 3.75 (br. s., 1H), 3.40-3.56 (m, 2H), 2.27-2.42 (m, 1H), 2.05 (dd, J=12.8, 5.7 Hz, 1H)
2,4-Diamino-5-[(E)-1-(methoxycarbonyl)-2-ethenyl]-7-(2-deoxy-b-D-erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine (8)
To a solution of 7 (391 mg, 1.0 mmol) in DMF (10 mL) including Et3N (0.28 mL, 2.0 mmol) and (PPh 3 ) 2 PdCl 2 (70 mg, 0.1 mmol) was added methyl acrylate (3.62 mL, 40 mmol), and the reaction mixture was heated to 70° C. for 5 h. The solvent was removed in vacuum, and the residue was purified by flash chromatography (silica gel, column, EtOAc:MeOH:H 2 O, 80:17:3). The main zone was collected and rotavap to a brown color solid of 3 (200 mg).
1 HNMR (300 MHz, DMSO-d6) ppm 7.82 (d, 1H, J=15.5 Hz), 7.71 (s, 1H), 6.36 (dd, 1H, J=5.7 and 8.3 Hz), 6.36 (br s, 2H), 6.30 (d, 1H, J=15.5 Hz), 5.82 (br s, 2H), 5.22 (d, 1H, J=3.5 Hz), 5.02 (t, 1H, J=5.8 Hz), 4.31 (m, 1H), 3.77 (m, 1H), 3.68 (s, 3H), 3.55 and 3.49 (m, 1H), 2.38 (ddd, 1H, J=8.3, 5.5, and 13.2 Hz), 2.09 (ddd, 1H, J=5.7, 2.9, and 13.2 Hz)
4-Amino-2-(2-deoxy-b-D-erythro-pentofuranosyl)-2,6-dihydro-7H-2,3,5,6-tetraazabenzo[cd]azulen-7-one (9)
A solution of 8 (1.1 g, 3.148 mmol) in 0.1 M NaOMe in MeOH (157 mL) was heated at 70° C. for 12 h. The reaction mixture was cooled to 0° C., and the resulting precipitate was collected to give 9 as yellow solid. The filtrate was removed in vacuo and the residue was purified by silica gel column eluted with MeOH (25%) in DCM to give additional 9 (1.3 g).
1 H NMR (300 MHz, DMSO-d6) ppm 10.08 (d, 1H, J=1.2 Hz), 7.34 (s, 1H), 6.93 (d, 1H, J=12.0 Hz), 6.29 (dd, 1H, J=5.9 and 7.9 Hz), 6.25 (brs, 2H,), 5.58 (d, 1H, J=11.6 Hz), 5.26 (d, 1H, J=3.6 Hz), 5.02 (t, 1H, J=5.8 Hz), 4.30 (m, 1H), 3.77 (m, 1H), 3.49 (m, 2H), 2.49 (m, Regiosela 1H), 2.12 (ddd, 1H, J=6.1, 2.3, and 12.8 Hz). [Hirama, Y. Biorg & Medic Chem 19, 352-358]
Synthesis of Compound 10
To a stirred solution of compound 9 (100 mg, 0.315 mmol) in 20% AcOH—H 2 O (v/v, 6 mL), was added dropwise a solution of NaNO 2 (45 mg, 0.66 mmol) in H 2 O (1.0 mL) at r.t. The stirring was continued for 1 h. 50 min, and the pH of the dark solution was adjusted to 8.0 with 25% aq NH 3 under cold condition. The solid obtained was filtered and dried (50 mg).
HRMS: [M+H] + =319.1
Synthesis of Compound 11
To a suspension of 10 (425 mg, 1.336 mmol) in dry pyridine (25 mL) were added diphenylcarbamoyl chloride (557 mg, 2.4 mmol) and N,N-diisopropylethylarnine (0.42 mL, 2.4 mmol). The mixture was stirred for 4 h at room temperature, and then poured in the 5% aqueous NaHCO 3 (50 mL) and extracted with CH 2 Cl 2 (2×100 mL). The combined CH 2 Cl 2 layers were dried over Na 2 SO 4 and clarified by filtration. The product 11 was then recovered by rotary evaporation and purified by flash chromatography (silica gel, elution with CH 2 Cl 2 followed by CH 2 Cl 2 —MeOH step wise from 0 to 4% methanol) to give a brown color foam (350 mg).
HRMS: [M+H] + =514.1721
Synthesis of Compound 12
Compound 11 (350 mg, 0.68 mmol) was dried by co-evaporation with anhydrous pyridine (2×, 15 mL) and dissolved in anhydrous pyridine (25 mL). This solution was treated with dimethoxytrityl chloride (276 g, 0.82 mmol) at room temperature under stirring for 4 h. Water was then added to the mixture and the stirring was continued for 35 min. The mixture was diluted with a 5% aqueous NaHCO 3 solution (100 mL) and extracted with CH 2 Cl 2 (2×350 mL). The combined extracts were dried over Na 2 SO 4 . The solvent was removed by rotary evaporation, and the product 10 was obtained as an orange-brown foam (400 mg) by purification by flash chromatography (silica gel, eluted with 2:1 to 1:2, hexane:ethyl acetate).
HRMS: [M+Na] + =838.28
Synthesis of Compound 13
12 (0.44 mmol, 400 mg), DMAP (0.25 mmol, 31 mg), Et 3 N (1.1 mmol, 0.154 mL), and Ac 2 O (0.528 mmol, 0.049 mL) were added to a solution of dry pyridine (10 mL). The mixture was stirred at room temperature for 2 h. MeOH (1 mL) was added, the mixture was diluted with 100 mL of dichloromethane and extracted with 5% NaHCO 3 (50 mL). The aqueous layer was back extracted with dichloromethane (100 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated by rotary evaporation. The residue was purified by flash chromatography (hexane:ethyl acetate, 2:1 to 1:2) to give product 13 (350 mg).
HRMS: [M+Na] + =880.2953
Synthesis of Compound 14
Compound 13 (350 mg, 0.41 mmol) was dissolved in a mixture (50 mL) of dichloromethane and methanol (7:3). The solution was cooled to 0° C., dichloroacetic acid (0.83 mL, 10.2 mmol) was added, and stirring was continued at 0° C. for 2 h. The mixture was then neutralized with aqueous saturated NaHCO 3 (50 mL), and extracted with dichloromethane (100 mL). The resulting organic layer was dried over sodium sulfate, concentrated by rotary evaporation, and the residue was purified by column chromatography (hexane:ethyl acetate 1:2 to 0:1) to give product as a white solid (155 mg).
HRMS: [M+H] + =556.1827
Synthesis of Compound 15
To a solution of compound 14 (0.155 g, 0.28 mmol) in pyridine (5 mL) and dioxane (10 mL) was added a solution of 2-chloro-4-H-1,3,2-benzodioxaphosphorin-4-one (0.085 g, 0.42 mmol) in dioxane (5.0 mL) at room temperature. After incubation for 15 min, a mixture of tributylammonium pyrophosphate in DMF (0.2 M, 4.2 mL, 0.84 mmol) and tributylamine (0.45 mL) was added. After incubating for 20 min, a solution of iodine (0.1064 g, 0.42 mmol) and water (0.315 mL) in pyridine (15.5 mL) was added. After incubating for 30 min, the reaction was quenched by the addition of aqueous Na 2 SO 3 (5%, until color disappears). The pyridine and dioxane were removed by rotary evaporation. The residue was dissolved in a mixture of water and acetonitrile (10 mL each) and kept at room temperature overnight. The product was resolved by reverse phase preparative LC (gradient 25 mM TEAA to 25 mM TEAA:CH 3 CN (1:1)=5:95 in 38 min, running time 46 min), with the solvents in the fraction containing the product removed by lyophilization. The residue was dissolved in ammonium hydroxide (2 mL), and the solution was stirred at room temperature for 3 h. The solution was injected onto an ion exchange HPLC column. The product (14 mg) was recovered as a yellow solid by lyophilization of fractions collected by gradient elution (water to 1 M ammonium bicarbonate over 32 min; running time 42 min)
HRMS: [M−H] − =556.9881 | This invention relates to processes that amplify, in a polymerase chain reaction architecture, oligonucleotide analogs that incorporate non-standard nucleobase analogs from an artificially expanded genetic information system. These pair in DNA duplexes via patterns of hydrogen bonds that are different from patterns that join the thymine-adenine and guanine-cytosine nucleobase pairs. | 2 |
This is a divisional of co-pending application Ser. No. 191,157 filed on May 6, 1988, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a superconducting circuit board and a paste adopted for forming a superconducting ceramic pattern on a ceramic board. Such a superconducting circuit board is useful for a 7 high speed computer such as a supercomputer.
2. Description of the Related Art
The insulating material used for a circuit board for high speed processing must have a low dielectric constant and the conducting material used must have a low electrical resistance, to ensure an efficient transmission of electrical signals. In the prior art, as such a circuit board, a multilayer ceramic circuit board is formed in which copper is used as the conducting material.
Recently, superconducting ceramics such as La-Ba-Cu-0 system, La-Sr-Cu-0 system, and Y-Ba-Cu-0 system which exhibit a superconductivity at the temperature of liquid nitrogen (77 K). have attracted attention and investigations into and developments of such materials are proceeding rapidly. To attain a superconducting circuit substrate, it is essential to develop a technique by which a superconducting ceramic paste can be printed on a ceramic board, such as an alumina board used in a hybrid IC, and fired to form an interconnection pattern of a superconductor.
Ceramic boards, including an alumina board, used for a circuit board, generally but except for a complete crystal monolith, have a structure comprising crystal grains, grain boundaries, also called a glass phase, and pores, and the higher the content of the glass phase, i.e., the lower the purity of the ceramic board, the lower the temperature at which the ceramic board can be fired or sintered. As a result, ceramic boards are generally manufactured by adding, to a ceramic, ingredients for a glass phase and able to be fired at about 1500° C. The ingredients for a glass phase are added to lower the firing temperature.
It was found that a fired, compacted body of a superconducting ceramics exhibits superconductivity, but if a pattern of a superconducting ceramic paste on an alumina board is fired to obtain a superconducting ceramic pattern, the resultant fired pattern does not exhibit superconductivity.
Thus, the object of the present invention is to provide a superconducting ceramic film on a ceramic board.
SUMMARY OF THE INVENTION
The above and other objects of the invention are attained by providing a superconducting circuit board comprising: a sintered alumina board containing more then 99% by weight of alumina; and a superconducting ceramic pattern formed on the alumina board.
The inventors found that a superconducting ceramics does not exhibit superconductivity after it is printed on a commercially sold alumina board as a paste thereof and is fired, because of a reaction of the superconducting ceramics with vitrious ingredients and amorphous SiO 2 and B 2 O 3 contained as impurities in the alumina board. This reaction results in a deviation of the composition of the superconducting ceramics, causing a loss of superconductivity. The inventors also found that, by using a high purity alumina board containing more than 99% by weight alumina, i.e., less than 1% by weight of impurities, a superconducting ceramic film or pattern can be obtained on the alumina board by printing a superconducting ceramic paste thereon and firing same.
The alumina content of an alumina board used in the present invention should be more than 99% by weight, preferably more than 99.5% by weight, more preferably more than 99.7% by weight. Preferably, the impurities or ingredients other than alumina involves a smaller amount of vitrious ingredients or amorphous SiO 2 B 2 O 3 , etc. More preferably, an alumina board is made by firing a high purity alumina with a small amount, e.g., about 0.3% by weight, of a sintering agent such as MgO and Cr 2 O 3 ; namely, a dense and pure sintered alumina board is more preferable. The process for manufacturing such a dense and pure sintered alumina board is described in ore detail in Examined Japanese Patent Publication (Kokoku) No. 55-11483, the disclosure of which is included herewith by reference.
The superconducting ceramics used in the present invention may be, for example, a superconducting oxide represented by the general formula:
A.sub.0.5-1.8 R.sub.0.2-2 M O.sub.2-5
where A stands for at least one element selected from the group consisting of Ba, Sr, Ca and Mg; R stands for at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; M stands for at least one metal selected from the group of copper, silver and gold; and O stands for oxygen.
The superconducting ceramics may also be bismuth-system (Bi-Sr-Ca-Cu-0 or Tl-Bi, Sr-Ca-Cu-O system) superconducting ceramics. The exact chemical formula of the bismuth-system superconducting ceramic material is not known but can be formed from a starting material of a mixture of Bi, Sr, Ca, and Cu compounds in a molar ratio (based on these elements) of 0.25-2:0.1-5:0.5-4. For example, 1:1:1:2; 1:1:1:3, 4:3:3:6; and 4:3:3:4. Further, another superconducting ceramic material can be formed from a starting material of a mixture of Tl, Bi, Sr, Ca, and Cu compounds in a molar ratio based on these elements) of 0.25-2:0.25-2:0.1-5:0.1-5:0.5-4. These superconducting ceramic materials exhibit superconductivity above the boiling point of the nitrogen (77K.)
To form a pattern of a superconducting ceramics on an alumina board, a paste is used comprising a superconducting ceramic powder with a vehicle such as an organic binder and a solvent. A typical composition of the paste is 100 parts by weight of the superconducting ceramic powder, 0.5 to 10 parts by weight, preferably 3 to 7 parts by weight, of the organic binder, and 5 to 30 parts by weight, preferably 7 to 9 parts by weight, of the solvent. If the amount of the organic binder is less than 0.5 part by weight, the ceramic powder is not sufficiently bound. If the amount of the organic binder is more than 10 parts by weight, it is difficult to maintain the shape of the paste pattern after drying. If the amount of the solvent, more specifically a non-volatile solvent, is less than 5% by weight, the viscosity of the paste is too high and it cannot be used for printing. If the amount of the non-volitile solvent is more than 30% by weight, the viscosity of the paste is too low for printing. When preparing a paste, a volatile solvent should be added in an amount of 10 to 30 parts by weight to 100 parts by weight of the superconducting ceramic powder, although the volatile solvent will be finally lost from the paste prepared for printing. If the amount of the volatile solvent is less than 10 parts by weight, it is difficult to uniformly disperse the ceramic powders, and the amount of the volatile solvent is more than 30 parts by weight, the time for preparation of the paste becomes undesirably long.
The superconducting ceramic powder in the paste may be replaced by powders of ingredients which can form a superconducting ceramic material by firing. For example, to form Ba 2 YCu 3 O.sub.δ, a combination of BaCO 3 , Y 2 O 3 and CuO may be used. The form of the ingredients may be, for example, oxide, carbonate, hydroxide, metal, etc.
The paste preferably further contains at least one of titanium and silane coupling agents to improve adhesion of the superconducting ceramic pattern with the alumina base, and if any, an insulating layer to be formed over or under the superconducting ceramic pattern. The content of the titanium or silane coupling agent is generally from 0.1 to 10 parts by weight, preferably from 0.4 to 1.0 parts by weight, to 100 parts by weight of the superconducting ceramic material. If the amount of the coupling agent is less than 0.1 part by weight, an improvement of the adhesion can not be realized. If the amount of the coupling agent is higher than 10 parts by weight, the viscosity of the paste becomes extremely high, which necessitates the addition of an excess amount of a solvent to reduce that viscosity, causing difficulty in maintaining the shape of a printed paste pattern. In addition, if the amount of the coupling agent is outside the above range, the efficiency of yield of a superconducting ceramic pattern is reduced.
It is also preferably that the superconducting ceramics to be formed from the paste by firing is a superconducting complex oxide containing copper and the paste contains ingredients for forming the superconducting complex oxide by firing, which ingredients include a metal copper powder to constitute the complex oxide after firing. This metal copper powder has ductility, and thus improves the printing characteristics of the paste. The metal copper has a high diffusion coefficient in a superconducting complex oxide, which allows the formation of a uniform composition of a fired paste pattern. For example, in an experiment, when copper oxide was used in a paste for forming a superconducting complex oxide and a line pattern of the paste was printed and fired, pattern width of at least about 200 μm was necessary to obtain a line pattern exhibiting superconductivity on a pure alumina board. In contrast, even with a line pattern width of 150 μm or 100 μm, a line pattern exhibiting superconductivity was obtained on a pure alumina board when metal copper powder was substituted for the copper oxide in the paste. The resultant superconducting line pattern had a width having a deviation of less than 10% of the original printed pattern width.
The improvement of the printing characteristics of a paste by an addition of a metal copper powder is also obtained when the metal copper powder is supplementally added to a superconducting ceramic paste. In this case, it is not necessary that the paste is a copper-containing superconducting ceramics. The paste also may comprise a powder of an already superconducting ceramics, and not ingredients which form a superconducting ceramics by firing. In these cases, i.e., when a copper powder is supplementally added, the fired pattern contains copper oxide in addition to a superconducting ceramics, but the fired pattern exhibits superconductivity as a line. This supplemental metal copper powder may be added in an amount of 2 to 15 parts by weight, preferably 5 to 10 by weight, based on 100 parts by weight of a superconducting ceramic powder or superconducting ceramic-forming powders.
In an embodiment, the superconducting ceramics may be a superconducting complex oxide represented by the general formula:
{(M.sup.II O).sub.x (M.sub.2.sup.III O.sub.3).sub.1-x }.sub.y.(CuO).sub.Z.(O).sub.δ
where M II stands for at least one element selected from the group of Ba, Sr, Ca and Mg; M III stands for at least one element selected from the group of Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; 0.5 ≦x≦0.9; 1≦y≦2; 1≦z≦2; δ stands for a deviation of the amount of oxygen from the stoichiometric amount thereof.
In a particular embodiment, the superconducting ceramics is represented by the formula: {(Sr u Ba 1-u O) x (Y 2 O 3 ) 1-x } y (CuO) z .(O)δ where x, y, z and δ are as defined above and 0<u<1. That is, this superconducting ceramics is a Ba-Y-Cu-O system superconductor in which Ba is partially replaced by Sr. In an experiment, it was found that the partial replacement of Ba with Sr makes the superconductor material denser and the superconducting transfer temperature T co lower, but at around u=0.5, the T co is becomes higher. Therefore, a Sr-substituted Ba-Y-Cu-O system superconductor in which about half of Ba is substituted with Sr is preferable because of a high density and a high T co , more specifically, 0.4≦u≦0.6 is preferred.
The superconducting ceramic pattern on the alumina board may have a multilayer structure. That is, after a superconducting ceramic pattern is formed on an aluminum board, an insulating layer may be formed over the superconducting ceramic pattern and another superconducting ceramic pattern formed on the insulating layer. The number of layers of the superconducting ceramic patterns is not limited.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a superconducting circuit board according to the invention;
FIGS. 2A and 2B are flow charts of the manufacturing process of a superconducting ceramics;
FIG. 3 shows an area of composition of a superconducting ceramics in M II O-M 2 III O 3 -CuO system;
FIG. 4 shows the relationship between the electrical resistance of the Ba-Y-Cu-O system sample and the temperature in Example 4;
FIG. 5 is a schematical view of a system for measuring a magnetization of a sample;
FIG. 6 is an X ray diffraction pattern of the Ba-Y-Cu-O system sample of Example 4;
FIG. 7 is electrical resistance and T co of the sample (Ba l-x Sr x ) 8 Y 2 Cu 10 O.sub.δ in relation to the composition in Example 5;
FIG. 8 is an X ray diffraction pattern of the sample (SrBa) 4 Y 2 Cu 10 O.sub.δ in Example 5;
FIG. 9 shows the lattice constants of the samples (Sr x Ba 1-x ) 8 Y 2 Cu 10 O.sub.δ in relation to the composition in Example 5;
FIG. 10 is a schematical view of a unit cell of the crystal structure of a superconducting ceramics Ba 2 YCu 3 O.sub.δ ;
FIG. 11 shows the magnetization of (SrBa) 4 Y 2 -Cu 10 O.sub.δ in relation to the temperature;
FIG. 12 is electrical resistance of a bulk and a film of a superconducting ceramics in Example 7;
FIG. 13 is an X ray diffraction pattern of the fired pattern of film of Ba 2 YCu 3 O.sub.δ formed on alumina board in Example 8;
FIGS. 14A and 14B are photographs of (Sr 0 .125 Ba 0 .875) 8 Y 2 Cu 10 O.sub.δ and (Sr 0 .5 Ba 0 .5) 8 Y 2 Cu 10 O.sub.δ, respectively.
FIGS. 15A and 15B are photographs of fired patterns made using Cu and CuO powders respectively; and
FIG. 16 is a sectional view of a multilayer circuit substrate in Example 12.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is further described by way of Examples.
EXAMPLE 1
(Pure Alumina Board)
0.6 mol of BaCO 3 powder having an average particle size of 1 μm, 0.4 mol of Y 2 O 3 powder having an average particle size of about 1 μm, and 1 mol of CuO powder having an average particle size of about 2 μm were mixed in a ball mill for 48 hours. To 100 parts by weight of this powder mixture, 1 part by weight of ethylcellosolve, 10 parts by weight of terpineol, 0.6 part by weight of a thixotropy agent and 20 parts by weight of methylethylketone were added and mixed in the ball mill for 72 hours. The mixture was grounded in an agate mortar for 1.5 hours and then n a three-=roll mill, and thus a superconducting ceramic paste was obtained.
This paste was screen printed on various alumina boards to for an interconnection pattern, and then fired in air at 1020° C. for 4 hours. The thickness of the pattern was 25 μm. In the following samples, the thickness of the pattern was varied. FIG. 1 shows the resultant alumina substrate 1 on which the interconnection pattern 2 is formed.
The resultant alumina board with the pattern was immersed in liquid nitrogen and the electrical characteristics of the patterns were measured.
The results are shown in Table 1.
TABLE 1__________________________________________________________________________ Super- Minimum thickness Purity of Sueface conductivity for exhibitingSample No. alumina (%) Impurity roughness (%) (at 20 μm) superconductivity (μm)__________________________________________________________________________1 92 vitrious 1.1 x xx2 96 vitrious 0.6 x xx3 97 vitrious 0.3 x xx4* 99 vitrious 0.1 x 5005* 99.5 vitrious 0.06 x 2006 92 vitrious 1.0 x xx7 96 vitrious 0.7 x xx8* 99.5 vitrious 0.07 x 2009* 99.7 MgO, Cr.sub.2 O.sub.3 0.03 ∘ <2010* 100 -- 0.01 ∘ <20__________________________________________________________________________ Note) ∘: Superconductivity exhibited x: Superconductivity not exhibited xx: Superconductivity not exhibited even if thickness thickned by screen printing method? *Example of present invention
It can be seen from Table 1 that a superconductivity of the fired pattern was exhibited when the alumina board contained more than 99% of alumina, and that when the alumina board did not contain a vitrious impurity, the fired pattern on the alumina board exhibited a superconductivity even if the thickness of the pattern was as thin as 25 μm.
EXAMPLE 2
The paste of Example 1 was screen printed on alumina board sample No. 9 shown in Table 1 (99.7% alumina with 0.3% MgO and Cr 2 O 3 ) to form a pattern having a thickness of 25 μm, and was then fired in air at 850° C for 1 hour.
The resultant fired pattern exhibited superconductivity in liquid nitrogen.
EXAMPLE 3
(Preparation of Superconducting Ceramics)
FIG. 2A shows a flow chart of the process of manufacturing a Ba-Y-Cu-O system superconducting ceramics. In the first step, the starting materials of BaO, Y 2 O 3 and CuO powders were mixed at a predetermined ratio; in the second step, the starting materials were wet milled and ground to form powders having an average particle size of less than 2 μm; in the third step, the powders were formed into a shape; and in the fourth step, the shaped body was fired in an oxidizing atmosphere at 550° to 1100° C., preferably 800° to 1100° C., more preferably 800° to 900° C., to obtain a Ba-Y-Cu-O system oxide.
FIG. 2B shows a flow chart of the process of manufacturing a superconducting ceramics of
{(M.sup.II O).sub.x (M.sub.2.sup.III O.sub.3).sub.1-x }.sub.y (CuO).sub.z (O).sub.δ
which is very similar to FIG. 2A.
In accordance with the flow chart of FIG. 2A or 2B, samples of M II -M III -Cu-O system oxides were prepared from various ratios of M II O, M 2 III O 3 and CuO, and the shaped bodies were fired in air at 850° C. for 6 hours. The electrical resistance of the resultant samples (cut to 2×4×14 mm) was measured by the four probe method. FIG. 3 shows an area of the composition at which the sample exhibited superconductivity at the temperature of liquid nitrogen (77 K). The superconductivity at 77 K was exhibited in the hatched area.
From this experiment, it was found that a superconductivity at 77 K was obtained when the composition of the starting materials was as follows:
{(M.sup.II O).sub.x (M.sub.2.sup.III O.sub.3).sub.1-x }.sub.y (CuO).sub.z
where 0.5≦x≦0.9, 1≦y≦2 and 1≦z≦2. However, this composition of the starting materials was different from the composition of the superconducting ceramics obtained by firing the starting materials. The latter is as shown below:
{(M.sup.II O).sub.x (M.sub.2.sup.III O.sub.3).sub.1-x }.sub.y (CuO).sub.z (O).sub.δ
where 0.5≦0.9, 1≦y≦2, 1≦z≦2 and δ stands for a deviation of the oxygen concentration from the stoichiometric amount thereof. The deviation of the oxygen concentration depends on the atmosphere and other firing conditions. Generally, -1<δ<2. However, FIG. 3 represents the composition of the superconducting ceramics after firing, by considering another axis, for example, an axis perpendicular to the sheet of FIG. 3 for the oxygen concentration.
In the above preparation, the Ba-Y-Cu-O system superconducting ceramics entered a liquid phase at about 850° C., but did not enter the liquid phase at 800° C. when observed by eye.
In FIG. 3, the point K shows the composition Ba 0 .6 Y 0 .4 CuO.sub.δ, and A.H. shows the composition
If x<0.5, x>0.9, or z<1, a superconducting ceramics is not obtained, and if z>2, only a small amount of superconducting ceramics can be obtained.
The molar ratios of the starting materials are as shown below. Here, M II O, M 2 III O 3 and CuO are considered to be xy, y(1-x), and z moles. Then, ##EQU1##
Typical molar ratios are shown in Table 2.
TABLE 2______________________________________ Molar Molar Molar ratio of ratio of ratio ofz y x M.sup.II O M.sub.2 .sup.III O CuO______________________________________1 1 0.5 0.25 0.25 0.51 1 0.9 0.45 0.05 0.51 2 0.5 0.3 0.3 0.31 2 0.9 0.6 0.06 0.32 1 0.5 0.16 0.16 0.62 1 0.9 0.29 0.03 0.62 2 0.5 0.25 0.25 0.52 2 0.9 0.45 0.05 0.5______________________________________
EXAMPLE 4 (
(Typical Superconducting Ba-Y-Cu-O System)
Powders of BaO, Y 2 O 3 and CuO were mixed at a ratio of 3:2:5, and milled for 24 hours in a ball mill containing acetone and alumina balls. The kneaded powders were dried and shaped under a pressure of 200 MPa at room temperature, and the resultant shaped body was fired in air at 850° C. for 6 hours. A Ba-Y-Cu-O system oxide was obtained.
The electrical resistance of the obtained sample was measured by the four probe method, and the electrical resistance of the sample in relation to the temperature shown in FIG. 4. The resultant T c-end was 88.5 K and the sample exhibited superconductivity at the liquid nitrogen temperature (77 K).
The magnetization of the sample was measured in a magnetization measuring system shown in FIG. 5, in which reference numeral 11 denotes the sample, 12 a magnet, 13 a pick-up coil, 14 a drive means, 15 a detector and amplifier, 16 an operating system center, and 17 a display device. The results are given below.
______________________________________Temperature Magnetization(K) (emu/g)______________________________________300 3.4 × 10.sup.-6 77 -5.8 × 10.sup.-2______________________________________
The sample was then subjected to X ray diffraction analysis with Cu-K.sub.α ray having a wavelength of 0.154 nm. The results are shown in FIG. 6. In FIG. 6, the peaks marked o show the existence of the perovski's type structure and the peaks marked V show the existance of CuO.
EXAMPLE 5
(Partial Replacement of Ba in Ba-Y-Cu-O System With Sr)
Samples of (Ba, Sr)-Y-Cu-O system were prepared having the composition (Sr x Ba 1-x ) 8 Y 2 Cu 10 O.sub.δ where x=0, 0.125, 0.25, 0.375, 0.5 and 0.75, corresponding to the point U in FIG. 3. The starting materials were powders of Y 2 O 3 (99.9%, particle size of about 2-3 μm), BaCO 3 (99.9%, particle size of about 2 μm), SrO (99%, particle size of about 2-3 μm) and CuO (99.9%, particle size of about 2 μm). These starting powders were mixed at molar ratios necessary to obtain the above compositions, kneaded and ground for 24 hours in a ball mill, and then shaped under a pressure of 200 MPa to form pellets having a radius of 15 mm and a thickness of about 3 mm. The pellets were fired on an alumina board in air at 950° C. for 12 hours.
The temperature-dependent resistivity, powder X ray diffraction, and temperature-dependent magnetization (by vibrating sample magnetometer) of the resultant samples were measured, the out surface of the sample was observed by a scanning electron microscope.
FIG. 7 shows the onset temperature T co and the resistivity at room temperature of the samples having different compositions, in relation to those compositions. The T co of the sample where x=0.75 was lower than 77 K.
As seen in FIG. 7, the resistivity at room temperature tends to decrease with a decrease of the Sr concentration, but reaches a minimum at x=0.5 and increases again with an increase of x beyond 0.5. The decrease of the Sr concentration causes a corresponding decrease of the T co , in spite of a decrease of the resistivity at room temperature, but the T co is abruptly increased at x=0.5 and rapidly decreased at x=0.75, to a temperature lower than 77 K. That is, at the point x=0.5, i.e., a Ba/Sr ratio of 1:1, the properties of the sample are varied.
From the SEM photographs of the samples of x =0.125 and x=0.5, it was found that the sample of x =0.5 had a smaller grain size and a higher density (see FIGS. 14A and 14B). If the resistivity of the grains are the same in the samples, the sample having a higher density has a smaller resistivity, and thus the decrease of the resistivity at room temperature at x=0.5 is considered to be a result of the increase of the density. A replacement of Ba by Sr has an effect of increasing the density of the Ba-Y-Cu-O system superconducting ceramic material.
Around x=0.5, the sample is denser and the T co is relatively high. Therefore, a composition around x =0.5, for example, x=0.4 to 0.6, is preferable to obtain a good superconducting ceramic pattern.
FIG. 8 shows the powder X ray diffraction pattern of a sample of x=0.5. The pattern does not show split peaks around 2 θ=32 degrees, corresponding to the crystal planes (103) and (013) of the orthorhombic system crystal. To determine the exact crystal structure, the method of least squares was used to calculated the lattice constant. The values of the observation, theory, and then differences of certain patterns are shown in Table 3.
TABLE 3______________________________________(SrBa).sub.4 Y.sub.2 Cu.sub.10 Oδ.a = 0.385.sup.0 nm, b = 0.385.sup.6 nm, c = 1.157.sup.9 nmhkl 2 θ (obs) 2 θ (cal) diff______________________________________001 7.613 7.636 0.023003 23.053 23.046 -0.007010 23.053 23.079 0.026103 32.873 32.844 -0.029110 32.873 32.868 0.005005 38.805 38.894 0.089113 40.522 40.526 0.004006 47.168 47.097 -0.071020 47.168 47.168 0.000123 58.624 58.668 0.044116 58.624 58.622 -0.002______________________________________
The difference between the theoretical and observatory values of every angle was less than 0.1 degree, and thus it was determined that the lattice constants were as shown below:
a=0.385 0 nm, b=0.385 6 nm, c=1.157 9 nm. The crystal structure was a tetragonal system, since a is equal to b.
An X ray diffraction pattern of the sample of X=0 had split peaks around 32 degrees, demonstrating that the sample is a orthorhombic system. Therefore, it was found that the crystal structure was transformed from orthorhombic to tetragonal systems at x=0.5.
In the same way as above, the lattic constants of the samples having various compositions were determined and are shown in FIG. 9. This result can be summarized into the following three groups, in which a change of T co is relation to the composition is also shown, for reference:
TABLE 4______________________________________ Lattice constantComposition a axis b axis c axis T.sub.co______________________________________x < 0.5 constant decrease decrease decreasex = 0.5 a = b increase increasex > 0.5 decrease constant decrease decrease______________________________________
Assuming that the barium of the crystal structure of Ba 2 YCu 3 O.sub.δ, is replaced by strontium, the changes of the lattice constants and T co of the above samples dependent on the composition can be explained as below. FIG. 10 illustrates a unit cell of the crystal structure of Ba 2 YCu 3 O.sub.δ, which corresponds to the point W in FIG. 3.
The decrease of the lattice constant of the c axis at the composition other than x=0.5 is considered to be caused by the replacement of Ba by Sr having an ion radius smaller than that of Ba.
When x<0.5, with an increase of the Sr concentration, the oxygens (01) on the b axis are removed to cause a decrease of the lattice constant of the b axis, but the oxygens (01') on the a axis are not removed sine there are many vacancies at the oxygen sites (01') on the a axis, and thus there is no change of the lattice constant of the a axis. The decrease of T co is assumed to be caused by a gradual breaking of the linear chains of Cu-O on the b axis.
When x=0.5, almost all of the oxygens (01) on the b axis are removed, and thus the lattice constant of the b axis becomes equal to that of the a axis; i.e., the orthorhombic system is transferred to the tetragonal system. With this structure, the linear chains of Cu-O are almost lost, but superconductivity is observed, and therefore, this superconductivity is attributed to the two-dimensional plane of the CuO, not the linear or one-dimensional chain of the Cu-O.
When x>0.5, if it is assumed that the oxygens (03) are removed with an increase of the Sr concentration, the decrease of the lattice constant of the a axis can be explained. Moreover, the T co is then abruptly decreased, since the oxygens (03) are a determinant of the superconductive current. Furthermore, if the oxygens on this site (03) are removed, the resistivity of the grains is increased, which cooperates with the increase of the density of the sample to increase the resistivity at room temperature.
FIG. 11 shows the magnetization of the sample of x=0.5 at a magnetic flux density of 41 Oe, in relation to the temperature. It was confirmed that, at T c =80.9 K, a complete diamagnetism was demonstrated to show a transformation to a superconductor. Since a zero electrical resistance and the Meissner effect were observed, the sample of x=0.5.was a superconductor although it has a crystal structure of the tetragonal system. The T co was then about 83 K.
EXAMPLE 6
(Titanium Coupling Agent)
0.6 mole of BaCO powder (average particle size of about 1 μm), 0.4 mole of Y 2 O 3 powder (about 1 μm) and 1 mole of CuO powder (about 2 μm) are mixed for 48 hours in a ball mill. To 100 parts by weight of this mixture, 3 parts by weight of polymethylmethacrylate resin as a binder, 20 parts by weight of terpineol as a non-volatile solvent, 6 parts by weight of a titanium coupling agent (KR-QS, sold by Ajinomoto K.K.) and 20 parts by weight of methylethylketone as a volatile solvent, were added and ball milled for 72 hours. The mixture was ground in an agate mortar for 1.5 hours and passed through a three-roll mill 30 times to form a superconducting ceramic paste.
The paste was printed on a sintered alumina board (99.7% alumina with 0.3% MgO and Cr 2 O 3 ) to form a pattern having a thickness of 25 μm and a width of 100 μm, which was fired in air at 950° C. for 0.5 hours.
The resultant board was immersed in liquid nitrogen, and the electrical resistance of the pattern was measured and found to be zero.
The adhesion of the fired pattern to the alumina board was measured by the peeling test. The adhesion force was found to be more than 3 kg/mm 2 . In comparison, the adhesion of the fired pattern was about 0.7-1.5 kg/mm 2 when the fired pattern was formed by the same procedures as above, except that the titanium coupling agent was omitted.
EXAMPLE 7
(Silane Coupling Agent)
Example 6 was a repeated, except that the titanium coupling agent was replaced with a silane coupling agent (A-187 sold by Nippon Yunika K.K.). The electrical resistance and the adhesion of the fired pattern were similar to those of Example 6.
EXAMPLE 8
(Ba-Y-Cu-O System Pattern)
The bulk of a superconducting ceramics having a composition of Ba 2 YCu 3 O.sub.δ was pulverized to an average particle size of about 1 μm. To 100 parts by weight of the superconducting ceramic powder, 5 parts by weight of polymethylacrylate resin, 20 parts by weight of terpineol, 100 parts by weight of methylethylketone, were added and ball milled for 72 hours, ground in an agate mortar for 3 hours, and then roll milled 30 times, and thus a paste of the superconducting ceramic material was obtained.
This paste was printed on an alumina board (99.7% alumina with 0.3% MgO and Cr 2 O 3 ), which was fired in air at 850° C. for 950 hours.
It was confirmed that the resultant fired pattern on the alumina board exhibited the superconductivity shown below. The electrical resistance of the fired pattern on the alumina board in relation to the temperature is shown in FIG. 12, and the T c-end was 89 K, which is very similar to the T c-end of the bulk, although the electrical resistance of the fired pattern was a little higher than that of the bulk above T c . The magnetization of the fired pattern was measured by a vibrating sample magnetometer (VSM) and showed the Meissner effect, although the degree of diamagnetism of the pattern was lower than that of the bulk. FIG. 13 shows the X ray diffraction pattern of the fired pattern on the alumina board, which has the same peaks of Ba 2 YCu 3 O.sub.δ as the bulk.
EXAMPLE 9
(Ba, Sr)-Y-Cu-O System Pattern)
The bulk of the superconducting ceramics of (Sr 0 .5 Ba 0 .5) 8 Y 2 Cu 10 O.sub.δ was pulverized to an average particle size of about 1 μm. The procedures of Example 8 were then repeated to form a fired pattern of (Sr 0 .5 Ba 0 .5) 8 Y 2 Cu 10 O.sub.δ on a sintered alumina board (99.7% alumina with 0.3% MgO and Cr 2 O 3 )
This fired pattern demonstrated superconductivity and a high density.
EXAMPLE 10
(Replacement of CuO With Metal Copper)
Powders of 52 g (0.3 mole) of BaCO 3 , 20 g (0.2 mole) of Y 2 O 3 and 28 g (0.5 mole) of metal copper were mixed. To the mixture, 100 g of methylethylketone was added and ball milled for 50 hours. Then, to this mixture, 0.9 g of ethylcellulose as a binder, 2.5 g of terpineol as a non-volatile solvent, and 2.6 g of dibuthylphthaiate as a plasticizer were added, ground in an agate mortar for 10 hours, and passed through a three-roll mill 45 times to obtain a paste having a viscosity of about 2000 poise.
The paste was printed through a 300 mesh screen onto a sintered alumina board (99.7% alumina with 0.3% MgO and Cr 2 O 3 ) by the screen printing method to form an interconnection pattern having a width of about 150 μm. The alumina board with the paste pattern was fired in air at 900° C. for 6 hours.
The electrical resistance of the fired pattern was measured, and is as shown in FIG. 12, in which the electrical resistance was zero at 77 K. The Meissner effect was also confirmed, and thus the fired pattern was a superconducting ceramic interconnection pattern.
This fired pattern is shown in FIG. 15A. In contrast, FIG. 15B is a similar photograph of a fired pattern manufactured by the same procedures as above except that CuO powder was used in place of the Cu powder. As seen in FIGS. 15A and 15B, the printed and fired pattern made using a copper powder is very clear, but the printed and fired pattern made using a CuO powder is deformed.
Similarly, the above pastes containing the copper powder or the CuO powders were printed to form patterns having various widths on the alumina boards, and the procedures mentioned above were repeated to fire the alumina boards with the patterns. The resultant fired patterns were examined to determine if they exhibited superconductivity, and the results are as shown in Table 5.
TABLE 5______________________________________Line width Paste with Paste with(μm) CuO Cu______________________________________500 o o300 o o200 o o150 x o100 x o______________________________________ o: Superconducting pattern formed with deformation of pattern within 10% of width. x: Superconducting pattern not formed.
EXAMPLE 11
(Supplemental Copper Powder)
100 g of a powder of a superconducting ceramic material of Ba 2 Y Cu 3 O.sub.δ, having an average particle size of about 1 μm, was mixed with 7 g of a metal copper powder, 3 g of ethylcellulose, 20 g of terpineol, 5 g of dibutylethylketone and 100 g of methylethylketone and ball milled for 50 hours. The mixture was ground in an agate mortar for 10 hours and passed 45 times through a three-roll mill to obtain a paste having a viscosity of about 2000 poise.
The paste was printed through a 300 mesh screen onto a sintered alumina board (99.7% alumina and 0.3% MgO and Cr 2 O 3 ) by the screen printing method to form an interconnection pattern having a width of 150 μm and a thickness of 25 μm. The pattern on the alumina board was fired in air at 900° C. for 6 hours.
The resultant fired pattern exhibited superconductivity and the electrical resistance thereof become zero at 77 K.
EXAMPLE 12
(Multilayer Interconnection)
FIG. 16 is referred. A plurality of sintered
25 alumina boards (99.7% alumina with 0.3% MgO and Cr 2 O 3 ) having a thickness of 0.2 mm were prepared. On an alumina board 21, a pattern of a superconducting ceramic paste 22 having a thickness of 40 μm was printed. Alumina boards 23 and 24 were perforated by a laser beam to form piercing holes 25 and 26 into which a superconducting ceramic paste was filled. Onto the alumina boards 23 and 24, patterns 27 and 28 of a superconducting ceramic pate were formed. Near the peripherics of the alumina boards 21 and 23, a gold paste 29 was printed as an adhesive. Then, the alumina boards 21, 23 and 24 were stacked and fired in air at 950° C. for 30 minutes. Thus, a multilayer circuit board as shown in FIG. 16 was obtained, in which spaces 30 are seen. | A superconducting circuit board is provided comprising a sintered alumina board containing more than 99% by weight of alumina and an interconnection pattern of an superconducting ceramics formed on the alumina board. Adhesion of the interconnection pattern to the alumina board is improved by an addition of Ti or Si coupling agent to a paste for forming the interconnection pattern. The use of copper powder in place of copper oxide powder as an ingredient forming a superconducting ceramics in the paste is advantageous for printing and obtaining a uniform superconducting ceramic pattern. | 8 |
RELATED APPLICATIONS
[0001] Not Applicable.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to electronic gaming apparatuses and more particularly to interactive electronic amusement apparatuses.
[0004] Electronic amusement apparatuses with visual or audiovisual displays are commercially available in many formats, ranging from the dedicated platforms of Sony [e.g.; PlayStation 2, PlayStation 1, Sony Windows CE Handheld, Sony VAIO laptop computer], Nintendo [e.g., Nintendo 64, Gameboy, Color Gameboy, etc.], Sega [e.g.; Dreamcast, Genesis, and handheld games such as the Game Gear which are linkable together], as well as open platform environments such as Windows, Macintosh, Windows CE, Unix, Linux, PALM, Sony Playstation 2, Microsoft X-Box, etc. Nintendo 64, Gameboy, Color Gameboy, etc.], Sega [e.g.; Dreamcast, Genesis, and handheld games such as the Game Gear which are linkable together], as well as open platform environments such as Windows, Macintosh, Windows CE, Unix, Linux, PALM, Sony Playstation 2, Microsoft X-Box, etc.
[0005] In the handheld and transportable area, the entries include the dedicated handheld games [e.g.: Nintendo Gameboy, Nintendo color Gameboy, SNK NeoGeo, Windows CE handhelds and compatibles, including those from Sony, NEC, Hewlett Packard, and Palm Pilot and compatibles, etc.]
[0006] In accordance with the teaching of one of present applicant's prior U.S. Pat. No. '509, video games that can stand alone, or play as a linked video game apparatus in a distributed video game network are taught, and practiced in the industry many years subsequent to the issuance of the '509 patent, such as in products like the Nintendo Gameboy with links, the Sega Gamegear, and intranet, and internet networked environments.
[0007] In accordance with another aspect of the existing amusement gaming technology, user interaction with the video game is restricted to one of a set of defined paradigms. For example, if the user is playing in a game, then that user must elect to play stand-alone or networked, multiple user, and, furthermore, the interaction rules in either case are linear and fixed. That is, in an action game, or role playing game, or sports game, or whatever game, the user is playing in accordance with a defined set of game rules for either the single player stand-alone mode, wherein the only opponent is the computer, or in the multiple player networked player game mode, where each of the user's interactions causes responses in accordance with a fixed set of defined rules, and where further the user's conduct and results are visceral, that is, you win, you lose, you gain a possession, you lose a physical possession such as a sword or power pill, and you use up some amount of time, energy, points, etc. in the process of playing the game, which determines how long you're allowed to play the game.
[0008] It would be desirable to have an electronic gaming apparatus based on a visual display which provides multi-variable based interaction and behavior, and where the interactivity and networking aspects are enhanced to provide both more complex user-game interaction based on user behavior and input to the game, but to further provide for a multi-variable based inter-electronic gamecard apparatus in an interaction. However, none of the prior art systems are compatible, or can provide for either the physical communications hardware and software, or the software game design methodology or logic necessary to provide these features.
[0009] Another significant drawback of present-day games is that the characteristics of the activity (that is, the play) are established by the programming of the game, and therefore remain the same. While a particular game may have many distinct levels of difficulty, the characteristic responses within any one level are constant and unvarying. Therefore, once a player has mastered the highest level in the game, he usually loses interest quickly, as the challenge is no longer present.
SUMMARY OF THE INVENTION
[0010] An electronic trading card apparatus is comprised of a processing subsystem, a user input apparatus and a display. The processing subsystem has a processing logic section, memory for storing behavior rules, and a communications interface for interacting with other ones of the electronic trading card apparatus. The user input apparatus is for use by a player. The processing subsystem provides programmed functionality which in combination form a persona responsive to the behavior rules, the user input apparatus and the communications interface. The display provides for a display presentation to the player responsive to the persona formed by the processing subsystem.
[0011] An interactive amusement device exhibits a behavior, for use by a player in a system of a plurality of the amusement devices. Each amusement device is comprised of a feature controller, a communications interface, logic and a display. The feature controller selects from a defined set of features to define an amusement device persona, wherein each device has a separate persona that is initially set to an initial family value. The persona is comprised of several elements, with each of the elements comprising several variables, wherein each said variable has an initial value.
[0012] The communications interface communicates with other ones of the amusement devices. The user interface communicates with the player. The logic for determining behavior in response to at least one of communications from other ones of the devices and from the player. The display for providing a presentation of the behavior responsive to the respective amusement device persona.
[0013] In one embodiment, the display includes structural elements capable of physical mechanical motion. The display can also provide a visual and/or an audible presentation. In a preferred embodiment, the associated initial values are reassigned a unique value upon each initialization of the device. In a networked embodiment, a plurality of the devices are associated as members of a same family, wherein the members of the same family have the same initial family values. In a preferred embodiment for each device, members of the same family are further characterized in that the initial family value is modified by a factor to create a unique persona.
[0014] Thereafter, the behavior of the device is modified responsive to communications with at least one of the other ones of the devices.
[0015] In one embodiment, the feature controller is responsive to voice commands from the player to define the card persona. In one embodiment, the communications interface is an acoustic interface, which can provide inter-device audio communication within human range of hearing. The acoustic interface can also selectively further provide for response to human voice commands.
[0016] In one embodiment the device is further comprised of an interface to a control apparatus for providing means for the player to interface with the device. The interface to the control apparatus provides, inter alia, for player modification of the device persona, and/or for player selection of a game action. In one embodiment, the device is further comprised of a filter for selectively filtering communications received from the other ones of the amusement devices.
[0017] In an alternate embodiment, the device can provide means for receiving communications from a first one of the other ones of the devices and for forwarding the communications to a second one of the other ones of the devices. In the alternate embodiment the device can further comprise a filter for selectively filtering the communications from the first one of the other ones of the devices prior to forwarding to the second one of the other ones of the devices.
[0018] In a preferred embodiment, the feature controller is responsive to a defined set of rules for selecting from the defined set of features. The feature controller can alternately be programmed to define the rules, and/or the rules can be at least in part learned from the player use of the device.
[0019] In one embodiment, two or more of the devices can provide means for exchanging the persona for the device with ad for the persona of one of the other ones of the devices. As described in greater detail hereinafter, the persona is comprised of personality, possessions, appearance and society. Personality can be comprised of a plurality of variables each having an associated starting value that is initially assigned based upon a family value and a pseudo-random individual family member value, wherein the values of the variables are further modified thereafter responsive to experiences representative of at least one of communications with other ones of the devices and with the player, wherein the range of change of the values is limited to a defined set of thresholds.
[0020] Possessions (and/or appearance) can be comprised of a plurality of variables each of which has an initial value which is thereafter continually modified responsive to at least one of the communications with at least one of the other devices and the player. The initial value for the variables for the possessions can be a fixed value, a random number, assigned at manufacture and/or assigned upon initialization. Society can be comprised of a plurality of variables that have no initial value, but are defined by the interaction that each of the devices undergoes with at least one of other ones of the devices and with the player. In a preferred embodiment, the behavior is in part exhibited as changes to the appearance of the device. The initial value of each of the variables is selectively further modified by an additional factor, resulting in a unique persona for the device. In a preferred embodiment, the device as in claim 1, wherein selected ones of the variables are further modified responsive to experience comprising communications and interaction of the respective device with at least one other one of the devices and the player.
[0021] The variables for personality can be further comprised of at least one element of a family name, an individual name, a character, a caste, a rank, aggressiveness, garrulousness, self-centeredness, altruism, openness, truthfulness, strength, intelligence, amenability, hostility, gender, sexual orientation, sexual drive, sexual availability, and sexual monogamy.
[0022] The variables for the possessions can be comprised of elements of wealth, rank, health, wisdom, and sex. The variables for the appearance can be comprised of elements of at least one of character caste, character rank, gender, beauty, and stature.
[0023] The variables for the society can be comprised of elements of other ones of the devices which share a common value of one of the variables with the respective device, and in communication with the respective device, a player in communication with the respective device, and communication with other ones of the devices which do not share a common value of one of the variables with the respective device.
[0024] In one embodiment, at least two selected ones of the devices interact in a role-playing game responsive to the logic which is responsive to stored game rules and data. In an alternate embodiment, the player can masquerade as a device, substituting for defined game rules and data to appear as a selected one of the devices in the role-playing game. The play of the role-playing game is comprised of a series of conversation interactions among the selected ones of the devices.
[0025] In a preferred embodiment, wherein the interaction among the selected ones of the devices occurs in a hierarchical order directly based on relative proximity of the selected devices to one another. The conversation interactions can be comprised of an introductory conversation from a first one of the devices and a reply response providing information on the variables of the persona of the second one of the devices.
[0026] In one embodiment, the first one of the devices communicates via the second one of the devices to indirectly communicate with a third one of the devices.
[0027] In a further embodiment, the second one of the devices provides an additional response of an introductory conversation to the first one of the devices, wherein the first one of the devices responds to the additional response of the introductory conversation by providing an additional reply response to the second one of the devices. The reply response results in a transfer of at least a portion of the value of a selected one of the variables from the second one of the devices to the first one of the devices.
[0028] The transfer can alternatively result in a change to the value of the respective variables of both devices in the transfer, or only result in a change to the value of the respective variable in only one of the devices in the transfer. The transfer of the value for the respective variable is governed by predefined rules associated with the respective variable. Each device can communicate with at least one of the players and at least another one of the devices. The device communicates at any given time with only one of the other ones of the devices. Each device can provide an active game with an associated display. The active game is divided into phases comprising a discovery phase and an active play phase.
[0029] A method of communicating is provided amongst a network of networked computing entities to provide feedback to a user representative of a group social behavior comprising and providing a uniform data structure for each said computing entity which defines group social behavior simulation and the data structure comprising interaction rules and initial conditions. The interaction rules are comprised of fixed and variable elements. The initial conditions are comprised of fixed, variable and random elements—modifying the variable elements of the interaction rules and the initial conditions responsive to interaction of the networked computing entities and exhibiting feedback of the group social behavior simulation to the user of at least one of the computing entities.
[0030] It is therefore an object of the present invention to provide a game that has ever-changing characteristics, in addition to being easily reprogrammed by the user/player.
[0031] It is a further object of the present invention to provide a multi-variable interactive electronic game apparatus.
[0032] It is a further object of the present invention to provide for a new and novel intergaming apparatus communications architecture, protocol, and implementations, to facilitate inter-amusement gaming apparatus communication.
[0033] It is a further object of the present invention to provide the methodology and structure for controlling and managing visual display generation for each of the electronic gaming apparatus based on the “persona” of the particular respective gaming apparatus, [which “persona” is itself a multi-variable aspect], but is also responsive to the “personae” of other nearby game apparatus that may be within communications range of the first game apparatus [this interaction is also multi-variabled, for instance, depending on the relative distance from the particular game apparatus to the specific nearby game apparatus, the persona of the specific apparatus and the status of the interaction activity being communicated with the particular game apparatus and the other specific game apparatus].
[0034] It is a further object to provide a computing entity (or electronic gaming apparatus) which exhibits the personae and can be utilized for general or specific group social behavior simulations and feedback.
[0035] These and other aspects and attributes of the present invention will be discussed with reference to the following drawings and accompanying specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] [0036]FIG. 1 is a block diagram of the single electronic trading card;
[0037] [0037]FIG. 2 is an overview of the logic that is implemented by the software and the micro-PC as illustrated in FIG. 1;
[0038] [0038]FIG. 3 shows the various types of interaction that can occur in a system, a situation with multiple interacting ETCs;
[0039] [0039]FIG. 4A shows the data structure of the rules portion of the persona;
[0040] [0040]FIG. 4B shows the initialization that takes place at the start of each game or simulation sequence;
[0041] [0041]FIG. 5 shows the communications message format used between ETCS in the preferred embodiment; and,
[0042] FIGS. 6 A-C illustrate the interaction between two ETCs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] While this invention is susceptible of embodiment in many different forms, there is shown in the drawing, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.
[0044] In accordance with one aspect of the present invention, the communication between the game apparatus can be provided in an audible output which is perceivable by the human users, either by communicating inter-card in the audible range or providing audible output in addition to whatever other inter-card communications is provided. In this way, the user will not necessarily understand all the communications, but will recognize distinctive audio patterns or signatures associated with the audio communications between the game apparatus.
[0045] In accordance with one aspect of the multi-variable persona and interaction, a set of families can be sent out, such as 100 [or any number] of families which are the set of families. Within those families there are members of the family. Thus, just as in real world, there are last names and first names, and oftentimes people of the same family have similar personae, that is, they are similar in many ways though not identical, or in some cases even alike. Likewise, within a family, having a defined persona, there is much variation due to the multi-variable nature of the present invention, where certain aspects of persona are adaptive and learned in accordance with defined nested multi-variable rules. Thus, a game developer, provided with the development interface hardware and software, can create a new family with defined members, or can add members to an existing one of the set of families.
[0046] An additional novel aspect of the present invention relates to the unique nature of each individual electronic gaming apparatus in that it develops a unique specific persona which is adaptable and interactive, starting from a defined particular persona from within a defined set of personae.
[0047] In accordance with another aspect of the present invention, a set of interactive electronic trading cards [“ETC”] is provided, much in the spirit of baseball and other sports and hobby trading cards which are printed on paper stock, and provide a whole genre of gaming amusement. For example, with the use of a control unit coupled externally to the ETC, various user inputs can be communicated to or programmed into that particular ETC.. Additionally, a separate processor direct interface is provided for coupling to either a developer system or other computing apparatus. In addition, a communications interface can be provided to permit remote communication, plug-in memory device couplings or other ways to supplement, alter or modify the ETC.
[0048] In accordance with another aspect of the present invention, communication is provided in an audible spectrum, both between the ETCs, and in the preferred, embodiment between the ETC and its owner. In one embodiment, the communications between the ETCs is entirely contained within the audible range, while in an alternate embodiment the communication is contained outside the audible range, in addition to or separate from the audible aspect of communication for perception by the human user. It is to be understood that this audible aspect of the ETCs is in addition to and complementary with the visual communication aspect of the ETC.
[0049] In a preferred embodiment, the ETC provides visual communication both through an electronic display [such as a liquid crystal display, LCD] and through three-dimensional physical attributes [such as molded plastic] and graphical aspects [e.g., color, textural wording, etc.]. This interaction may be further enhanced by adding mechanical motion or visual display, allowing, for example, eye motion, facial expression, or hand gestures.
[0050] In accordance with a further aspect of the present invention, within the audible communication, the persona of the ETC is reflected in the audible, such as women's voices being higher in pitch than men's voices, shyness equating to softspokeness, boldness equating to speaking more loudly, in both cases tempered by emergency or other occasion in either direction of speaking soft or loud. In accordance with another aspect of the present invention, the ETCs provide for transfer of both individual features and entire personae between agreeing and consenting ETCs. Again, in the spirit of paper trading cards, people get tired of the trading card they might have and might like to try a different type of trading card. For example, a warrior may want to become royalty, or vice versa. A princess may want to become a ballerina or a performer of other sort. Thus, in the spirit of trading cards, you can trade your card. This can be done by physically trading the card, which would be appropriate where there was a physical aspect of the gaming apparatus embodying the ETC which was unique [e.g., a man versus a woman, a giant versus a midget, etc.]. However, in a preferred embodiment, the physical attribute is interchangeable or modifiable on a person's own ETC.
[0051] In a preferred embodiment of this aspect of the invention, the persona interchange can be accomplished with the same medium of communication [in the preferred embodiment having the audible component] so that owners of electronic trading cards (the ETCs) can “swap” all or part of their existing ETC for someone else's, or can perhaps “clone” one from another.
[0052] Of course, the persona of any particular ETC depends not only on its original ‘programming” but also on its experience. Therefore, no two ETCs will be identical, except for the instance of manufacture or of “cloning”.
[0053] Architecturally, the ETC is comprised of a processing subsystem component including processing logic, nonvolatile storage memory, working writable reusable storage area, and communications interfaces, as well as conventional power supply user interfaces, housing, etc. . .
[0054] In accordance with another aspect of the present invention, interaction between ETCs is complex and multi-variable. Personae can include degrees of truthfulness and lying, kindness and meanness, and other attributes and features as described herein after as elements of the person.
[0055] In accordance with another aspect of the present invention, even the concept of communication is multi-variable. There is of course direct communication of something from one to another ETC, and possibly back again or there from/to yet another ETC, and so forth. In much the same nature as a story being told and repeated gets altered, information passing between personae can change in accordance with aspects of the persona such as memory, truthfulness, boastfulness, and so forth.
[0056] In addition with another aspect of the present invention, the communications is additionally affected by the topography of the totality of ETCs interacting. For example, between ETCs which have other ETCs spaced and intercepting, and/or forwarding communications with more then one ETC. As the number of ETCs in the communications grows, and as the number of ETCs in a given chain of communications increases, the authenticity, or original content, of the communications is altered. In accordance with another aspect of the present invention, an interactive gaming environment is provided where the player/user can respond in real time to the visual and audio presentations provided by the user's ETC so as to adapt for and respond to what is happening with other ETCs, utilizing the user/player's responses including reflexes, intuition, and strategies.
[0057] Definition of Persona:
[0058] Each device has a persona that is set to some initial value at the time of manufacture or initialization. The persona of a particular device consists of several elements, each element comprising several variables. Each such variable has an initial value that is set at manufacture, which value may be zero for certain variables of some elements, and in other cases determine the initial “genetics” of the character represented by the particular device.
[0059] Each such variable may be further modified at the time of manufacture/initialization by a random factor, resulting in a unique persona for each such device. Certain of the variables may be further modified by the experiences that each device undergoes as it is used/played; that is, communications/interaction with other devices and with user/players.
[0060] In the described implementation, the basic elements of the persona are as follows:
[0061] I. Personality
[0062] II. Possessions
[0063] III. Appearance
[0064] IV. Society
[0065] Personality is further divided into the variables of:
[0066] 1) name; which is further divided into caste, family, and individual;
[0067] 2) character; which is further divided into caste and rank;
[0068] 3) aggressiveness;
[0069] 4) garrulousness;
[0070] 5) self-centeredness; (the opposite of altruism)
[0071] 6) openness
[0072] 7) truthfulness;
[0073] 8) strength;
[0074] 9) intelligence
[0075] 10) amenability (the opposite of hostility)
[0076] 11) sexuality; which is further divided into gender, orientation, drive, availability, and monogamousness;
[0077] Possessions is divided into the variables of:
[0078] 1) wealth
[0079] 2) rank
[0080] 3) health
[0081] 4) wisdom; and
[0082] 5) sex
[0083] Appearance is divided into the variables of:
[0084] 1) character, which is further divided into caste and rank, but which need not be identical to the variable of the same name in “Personality”;
[0085] 2) gender; which in a similar fashion need not be identical to that within the variable of sexuality;
[0086] 3) beauty; and
[0087] 4) stature
[0088] and Society consists of:
[0089] 1) cards (other devices) in caste in contact (that is; intimates); and
[0090] 2) other cards in contact; and
[0091] 3) users/players in contact (user/players may be disguised as other cards/devices)
[0092] Use in a Game:
[0093] One of the purposes to which the ETCs may be put is in a role-playing game in which each of several different ETCs take part, and a player/user may or may not take part, usually (but not necessarily) behaving and appearing to be (masquerading as) an ETC. The play consists of a series of interactions (“conversations”) among ETCs that are nearby to each other, and then in turn among ETCs that are further separated.
[0094] Each such conversation starts with an introductory phase consisting of one asking the other “who are you?” in the digital language of the ETCs. The second ETC in that conversation would then reply with the basic information about its caste, rank, etc. from the “Appearance” element, which of course need not be exactly equivalent the that in the “personality” element, depending on the value of the “truthfulness” variable.
[0095] The second ETC might then ask the first for the same basic information. After this first transaction, there might (depending on a random factor present in all transactional opportunities) occur a second where one asks the other “who is behind you?”; that is, “what other ETCs are you in contact with that I may not be?”. The basic information about these second-level communicants would then be transferred, potentially modified according to the degree of “truthfulness” of the reporting ETC.
[0096] A third stage of the interaction might result in the transfer of some degree of one or more of the variables in the element “Possessions” from one ETC to another. This transfer would be regulated by the current values of the elements of Personality. For instance, if one ETC of a specific rank encounters one of a higher rank and with a larger degree of Aggressiveness, there might result a transfer of Wealth from the former to the latter.
[0097] Similarly, the proper conjunction of the variables within Sexuality and Appearance might result in the transfer of Sex from one to the other. In this case, the sum is not a constant; that is, both may gain Sex, or even neither.
[0098] Just as in humans, the transfer of Possessions among ETCs is governed by rules peculiar to each variable within the element. For instance:
[0099] 1. Wealth is lost by one party and gained by the other in equal amounts;
[0100] 2. Wisdom may be given, but the giver's store does not decrease as a result;
[0101] 3. Health may be taken, but is usually not given; the taker's own store does not increase, although a giver's may decrease.
[0102] 4. Rank may be given without loss of the giver's store, but under certain circumstances such a gift may result in loss, for instance if given to one of much lower rank;
[0103] 5. Sex may be given with a net increase for both giver and receiver, or it may be taken (by one of higher rank or greater strength for example), in which case there is always an increase in hostility (decrease in amenability)
[0104] Thus, the active game may be divided into phases, consisting of:
[0105] 1. discovery phase, consisting of each card leaning about its close neighbors, and then getting reports on its neighbors' neighbors. During this phase, the characteristics reported may be untrue, due to the action of the truthfulness variable.
[0106] 2. the active play phase, during which requests for more detailed information are processed, followed by requests and demands for possessions, perhaps with offers.
[0107] Interaction Between ETCs and a Human User/Player:
[0108] There two different manners in which the user/player can interact with the set of ETCs that he/she is using. First, he/she may arrange the ETCs in a pattern of his choice, establishing proximity, and therefore strongest interaction, among certain ETCs, in order to obtain a particular interaction. Having established the initial conditions, he would then observe the resulting activity without interfering; the outcome would depend entirely on his skill in establishing the start-of-play arrangement. This might be termed Observer mode.
[0109] Alternatively, he may disguise himself as another ETC; that is, as far as the reactions of the ETCs with which he interacts are concerned, he is just another ETC. This is accomplished by providing an ETC with a special interface that allows the user/player direct access to the appropriate parameters of the appearance segment of the persona, and therefore control over the responses of his character to communications initiated by other ETCs. This would be termed Immersive mode.
[0110] In this mode, he can further initiate communications with other ETCs as desired, using the established communications protocols for that purpose.
[0111] Each of these modes has two further alternatives: Normal and Omniscient. In a Normal mode, the user/player would be able to observe only the same information that another ETC would have access to; that is, his observations would be subject to the same degree of dishonesty, secretiveness, and so forth, that one ETC would use to another—the user/player would not be able to “see the truth”. In an Omniscient mode, the player/user would be able to observe the entire set of parameters in each ETCs persona at will, thereby “seeing through” the distortions inherent in normal communications.
[0112] Therefore, in Omniscient Observer mode, the player/user would be able to see the developing relationships among the ETCs, and would be able to observe the distortions that each ETC introduces to gain a desired response from other ETCs.
[0113] In Omniscient Immersive mode, the player/user would be able to “see through” the distortions in the same manner, and therefore would be better equipped to gain the desired responses himself.
[0114] [0114]FIG. 1 is a block diagram of the single electronic trading card. This card comprises a microprocessor 120 with ROM, RAM, Flash, Programmable ROM and multiple I/O interfaces to the other element. A liquid crystal or similar display 102 showing variable features is embedded in the printed and molded fixed features 101 and coupled to one of the I/O ports on micro-PC 120 . A bi-directional acoustic interface 130 coupled to another one of the I/O ports on micro-PC 120 . This bi-directional acoustic interface can accept spoken commands from the human player/user through port 151 , and can project sounds to the human through port 150 , thus implementing its voice, that is what's perceptible by the human. Optionally, another acoustic link can connect to a control unit 140 with buttons and display, is suitable for use by a human player/user. A fourth acoustic interface 134 for purposes of exchanging information and commands and requests with other electronic trading cards and a final acoustic interface 133 that is designed for interacting with a hosting or programming personal computer or other computing device. There also can exist an infrared interface 131 that can alternatively form the interface to the PC described above or to the user/player control unit
[0115] The software in the micro-PC 120 is programmed to create the logic that creates the behaviors driven by the elements and variables described in other places that actually form the personality, the persona, of the particular electronic trading card.
[0116] Further, a motion controller 133 , connected to micro-PC 120 via an I/O port, activates moving element 134 under command of micro-PC 120 .
[0117] [0117]FIG. 2 is an overview of the logic that is implemented by the software and the micro-PC described earlier. It comprises a logic unit 200 that contains the rules by which the various decisions are made. The primary input to this logic unit is from the communications input system 240 whereby flow stimuli 241 from other cards or from other user/players in the system. The logic unit is similarly fed by the persona 210 comprising a set of behavior rules 211 and the individual parameters determining the unique characteristics of that particular electronic trading card. These parameters comprise element 212 . Changes to the parameters in the persona flow from the logic unit through the change path 214 . Another input to the logic unit is from the particular electronic trading card's world-view block 220 comprising a variety of data elements 221 describing the social environment of that particular card, that is the data the card has collected about other cards and user/players in its vicinity that it must interact with. Changes in the world-view flow up via path 224 from the logic unit 200 to world-view 220 . As a result of computations in the logic unit, not only are changes in the persona 210 executed and changes in the world-view 224 executed, but changes in the appearance of the individual electronic trading card (ETC) flow through the behavior channel 230 to the display elements 235 which in turn may comprise a liquid crystal or other display 236 and potentially mechanical elements, such as moving arms, etc., elements 237 . Together these comprise the appearance of the individual electronic trading card. Further behavior is transmitted via behavior channel 230 to the communications output system 231 where it may send information about itself, etc. to together electronic trading card and to the user in this role as an electronic trading card. Furthermore, this communications output system may send information that is orally significant to the human, albeit that information would always be contained or at least hinted at by information sent via the data communications channel that 231 also implements.
[0118] [0118]FIG. 3 shows the various types of interaction that can occur in a system, a situation with multiple interacting ETCs. In this particular case, cards 301 , 302 , 303 , and 304 may directly interact with one another as shown via the connecting lines. Card 305 may interact directly with cards 306 , 307 , 304 , and 303 as shown by the connecting lines. Any communications that card 305 has with cards 301 and 302 can only be consummated by passing through, by being relayed by card 303 and/or card 304 . Therefore, the understanding that card 305 has about 301 and 302 is subject to filtering by the biases of cards 303 and 304 . This establishes another important aspect of the game. Cards 303 and 304 may well lie to card 305 when they relay the information about cards 301 and 302 . This filtering can have a very large effect on the outcome of the game, insomuch as some of the decisions that card 305 , some of its behavior, may be as a result of false information about cards 301 and 302 . Card 306 is in a similar position with regard to cards 301 and 302 . Card 307 can communicate directly only card 305 , therefore, not only is its knowledge about cards 303 , 304 , and 306 subject to the same degree of filtering as described about card 305 above, but further, its knowledge about cards 301 and 302 can be filtered by as many as two, or in an extreme case, three other cards on its way. So, in fact, it may get quite conflicting information about cards 301 and 302 as relayed by, for instance, cards 303 and 305 in one case, cards 304 and 305 in a second, and cards 304 , 306 and then 305 in a third case. Again, this can have a dramatic effect on the behavior of card 307 with regard to its understanding of the character of cards 301 and 302 . Just as in human society, the results of miscommunication, filtering, and just plain untruths can be seen and might be dramatic.
[0119] [0119]FIG. 4A shows the data structure of the rules portion of the persona. As can be seen, the persona consists in this case of four elements, that is, personality, possessions, appearance, and society. Each of those primary elements is further divided into a number of variables. Some of the variables, in turn, are divided into sub-variables. For example, the first element in personality is “name”, which is divided into “family” and “individual” , just as human names are divided into given names and family name. “Character” is similarly divided into the sub-variables of “caste” and “rank”. Aggressiveness, garrulousness, self-centeredness, openness, truthfulness, strength, intelligence, and amenability are single variables and sexuality, in fact, has in this implementation, four sub-variables, which all have important bearing upon the interaction of this card with another.
[0120] [0120]FIG. 4B shows the initialization that takes place at the start of each game or simulation sequence. The individual Computing Element's Persona 401 holds values that are either the result of the last game or sequence; or those implanted at the time of manufacture or “hard reset”. The Initialization Sequencer 404 reads each element of the Persona 401 in turn, compares it with the appropriate element in the Manufacturing Limits, resetting it to a mid-level when the limits are exceeded; modifying it by an amount from the Random Value Generator; and writing it back to the appropriate element of the Persona 401 .
[0121] The Initialization Sequencer 404 then repeats the above sequence for the next element of the Persona, continuing until all elements have been processed.
[0122] [0122]FIG. 5 shows the communications message format used between ETCS in the preferred embodiment. Each message is composed of a series of fields, each field being either a key-word, or a modifier or data field associated with the key-word. Each field is terminated by an end-of-field character, EOF.
[0123] First is a start-of-message character, SOM. The SOM is immediately followed by a message number, used to detect and deal with missing or duplicate message transmissions. The next field is the address field. The address may point to a particular other entity in the network by name, rank, an individual or given name. Or it may be more general, that is, all members of the family Stuart.
[0124] The third full field is the identity of the sender. This field may be further modified by characteristics as yet undefined.
[0125] The next field is the operator that defines the purpose of the message. For example, it may be a request for information, “RI”; a request for possessions, “RP”; an offer of information, “OI”; an offer of possessions, “OP”; a reply to a previous specific inquiry; or another operator that may be defined at a later time.
[0126] The next field is the imperative level of the preceding operator, ranging from none to very high, with allowance for an absolute; or it may be a null; that is, have no meaning.
[0127] The sixth field is the definition of the information or possession to which the message relates; that is, a pair of pointers, or in the preferred embodiment, names, referring to one of the fields defined in FIG. 4.
[0128] The seventh field is the amount, quantity, or depth of the information or possession involved.
[0129] The eighth and last full field is reserved for message-specific data, as may be necessary for some specific interactions.
[0130] Finally, the message is terminated by and End-Of Message character, EOM.
[0131] FIGS. 6 A-C provide an illustration of interaction between two ETCs. The interaction starts with message number 1 , sent by A. B the replies with his full name.
[0132] In message 3 , A then requests of B a report on B's level of wealth, which B refuses to answer, instead stating his hostility level via message 4 .
[0133] In return, A attempts to cow B with his great strength. B quickly complies via message 6 —“I've got 500 crowns.” Of course, if B's propensity to lie is substantial, controlled by a low value for the Truthfulness field in “his” persona (persona is detailed in FIG. 4), then the answer given to A may not at all reflect the truth—B's Wealth variable may in fact hold several thousand crowns.
[0134] A then demands 100 crowns, which B hands over in message 8 . As a result of this interchange, A's wealth variable will be increased by the 100 crowns, and B's decreased. Simultaneously, B's amenability variable may be decreased, reflecting B's hostile reaction to the interchange; the amount depending on a random choice and on other rules that the character's designer may elect to include.
[0135] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims. | It is a method of communicating amongst a network of networked computing entities to provide feedback to a user representative of a group social behavior comprising and providing a uniform data structure for each said computing entity which defines group social behavior simulation and the data structure comprising interaction rules and initial conditions. The interaction rules are comprised of fixed and variable elements. The initial conditions are comprised of fixed, variable and random elements—modifying the variable elements of the interaction rules and the initial conditions responsive to interaction of the networked computing entities and exhibiting feedback of the group social behavior simulation to the user of at least one of the computing entities. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to high voltage vacuum interrupters of the type containing a shield within an evacuated glass envelope for preventing metallic vapors from condensing on the inner surface of the envelope.
The shield is mounted within the envelope by means of support ring mounted within the glass envelope. One arrangement for mounting the support ring consists of inserting the rim of the ring within annular recesses formed on the inner surface of the glass envelope. U.S. Pat. No. 3,048,682 discloses one method of providing annular recesses on the inner surface of the glass envelope.
U.S. Pat. No. 3,376,186 discloses a shield support ring assembly wherein the ring is embedded within the glass envelope by a centrifugal casting operation. U.S. Pat. No. 4,000,999 discloses a further method for forming a shield support ring within the glass envelope. U.S. Pat. No. 4,158,911 discloses a method for manufacturing a vacuum tight circuit interrupter which includes the step of vibrating the interrupter sub assembly to remove loose glass particles.
One of the problems inherent with embedding the shield support ring within the glass envelope is the occurrence of ionizable particles within the evacuated container. The particles reduce the dielectric strength of the electrode gap and cause the vacuum switch to become conductive below the design voltage. A major source of the ionizable particles has been traced to glass which has loosely adhered to the inner wall of openings in the shield support ring. Various methods for removing the glass prior to evacuation have heretofore proved ineffective.
The purpose of this invention is to eliminate the source of ionizable glass particles from shield support rings embedded within high voltage vacuum interrupter envelopes.
SUMMARY OF THE INVENTION
The invention comprises a vapor shield support ring for high voltage vacuum interrupters having a plurality of quasi rectangular slots for permitting the passage of molten glass during the envelope forming process. The invention further comprises the method of complete encapsulation of the rectangular slots during the formation of the glass envelope to eliminate the formation of narrow apertures on whose walls loosely held glass particles can form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a prior art high voltage vacuum switch envelope;
FIG. 2 is a plan view of a prior art shield support ring for use with the vacuum switch envelope of FIG. 1;
FIG. 3 is a plan view of the shield support ring of FIG. 2 sealed within the vacuum switch envelope of FIG. 1;
FIG. 4 is an enlarged plan view of a part of the configuration of FIG. 3;
FIG. 5 is a plan view of a shield support ring according to the invention;
FIG. 6 is a plan view of the shield support ring of FIG. 5 sealed within a vacuum interrupter envelope;
FIG. 7 is an enlarged plan view of a part of the configuration of FIG. 6;
FIG. 8 is a graphic representation of the relationship between the number of good vacuum switches resulting as a function of the ratio of the minor to major dimension of the slot within the shield support ring of the invention, and
FIG. 9A and FIG. 9B are schematic representations of two configurations of the major and minor dimensions of the slot within the support ring of FIG. 5.
GENERAL DESCRIPTION OF THE PRIOR ART
One type of a high voltage vacuum switch (also called interrupter) can be seen by referring to FIG. 1 where a glass envelope 10 contains a flange 11 at each end and one or more vapor shield support rings 12 intermediate the ends. The vapor shield supporting ring 12 is embedded within the envelope 10 by a method of centrifugal glass casting where the glass material passes through a plurality of apertures 16 called "ports" and wherein the outer perimeter 14 extends outside the glass envelope 10 and the inner perimeter 15 extends within the interior portion of the glass envelope 10. The inner perimeter 15 serves to support the shield assembly for the purposes described earlier. The top flange 11 can be seen to extend above the rim 13 of the glass envelope 10 and serves to connect with an electrode mounting assembly.
The vapor shield support ring 12 is shown in FIG. 2 to consist of a plurality of circular apertures 16 proximate the outer perimeter 14 and a lesser number of slots 17 proximate the inner perimeter 15. The apertures 16 serve to provide a transit path for the molten glass during the centrifugal casting procedure employed in the formation of the glass envelope 10. The molten glass passes from a bottom section of a glass forming mold through the apertures 16 to a top portion of the mold. The slots 17 serve to position and to support the vapor shield assembly when the glass envelope 10 is processed into a vacuum interrupter.
The shield support ring 12 is shown formed within the glass envelope 10 in FIG. 3. The ring 12 is formed within the glass envelope 10 in such a manner that the inner perimeter 15 extends within the envelope 10 and the slots 17 proximate the inner perimeter 15 project within the envelope 10 for providing support to the vapor shield assembly as discussed earlier. The outer perimeter 14 extends beyond the envelope 10 and serves as an electrical connection means for the vapor shield assembly. The port apertures 16 are partially embedded within the envelope 10 and partially extend within the inner surface 8 of the envelope 10. During the casting process wherein molten glass transports through apertures 16 some molten glass adheres to the inner surface of the apertures.
The glass is partially removed by means of a grit blasting technique after sealing the ring 12 to envelope 10. It has since been discovered that the extremely thin brittle layer of glass remaining on the inner surface of the apertures becomes displaced upon continued operation of the vacuum switch. The extremely small particles of glass within the evacuated envelope 10 become ionized during the switching operation and reduce the voltage at which the vacuum interrupter operates. FIG. 4 is an enlarged view of one aperture 16 on a ring shield 12 sealed within glass envelope 10. The outer ring perimeter 14 extends beyond the glass envelope as described earlier, and the inner perimeter carrying the shield assembly slot 17 extends within the envelope inner surface 8. The aperture 16 having a diameter D is only partially covered by the material of the glass envelope 10 and is also partially exposed. A thin layer of excess glass 7 remains even after a careful grit blasting removal procedure and becomes a source of contamination within the sealed vacuum interrupter. Since the shield ring 12 is integrally embedded within the glass envelope 10 during the casting process the aperture diameter D must be of sufficient size to ensure that a desired quantity of molten glass can pass through the apertures during the glass forming process. It has hence been discovered that for a given width S of ring shield 12 the opening of aperture 16 is critical. If the diameter D is decreased in size an insufficient rate of flow of glass results during the envelope forming process. Increasing the number of apertures 16 and decreasing the aperture diameter D has not heretofore been successful in an attempt to embed the apertures completely within the glass envelope without seriously effecting the seal existing between flange 11, shield 12 and glass envelope 10.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The shield support ring 12 according to the invention can be seen by referring to FIG. 5. A plurality of quasi rectangular slots 18 are provided proximate to the outer perimeter 14 to provide for the passage of molten glass during the envelope forming process. The inventive support ring 12 within the glass envelope 10 is shown in FIG. 6. The rectangular slots 17 extend within the inner surface 8 of glass envelope 10 and provide the same functions as described for the prior art embodiment of FIG. 3. The outer perimeter 14 of ring 12 extends exterior to glass envelope 10 and the plurality of quasi rectangular slots 18 are completely embedded within the envelope. FIG. 7 shows an enlarged view of one quasi rectangular slot 18 completely encapsulated within glass envelope 10 wherein outer ring perimeter 14 and inner ring perimeter 15 are outside the glass material. The thickness S of ring 12 is the same as for the prior art embodiment of FIG. 4 and the shield support slots 17 are similar in size and number to those described earlier for the embodiment of FIG. 4. The length L and width W for the quasi rectangular slot 18 are critical in both design and number for the following reasons. In an attempt to design an opening for the transfer of molten glass during the glass envelope forming process the opening must be sufficient in size to allow for the transport of molten glass and yet become completely embedded within the glass during the glass casting operation. This was not feasible for the prior art configuration of FIG. 4 since a circular opening of diameter D would require a substantial quantity of glass to completely extend over the entire diameter. The excess quantity of glass was found to interfere with subsequent vacuum interrupter construction. As discussed earlier, attempts to reduce the diameter D resulted in an insufficient rate of flow of glass being transferred through the smaller diameters thereby causing sealing problems. Attempts to increase the number of apertures 16 of a reduced diameter were also unsuccessful since the viscosity of the molten glass prevented its complete passage through the smaller diameter openings during centerfuging. Also the colder glass subsequently delivered to the top flange 11 (FIG. 1) did not adequately bond to it. Considering the total cross sectional area of the plurality of slots 18, in FIG. 7, to constitute a "port" size for the transport of molten glass, the total port dimension was found to be equal to or greater than the port provided by the plurality of apertures 16 for the embodiment of FIG. 4 in order to produce good vacuum switch seals. Earlier test data indicates that the poor seals result between the support ring and the glass envelope when the port opening is too small for a sufficiently rapid transfer of molten glass. Good seals are achieved when the aperture diameter D (FIG. 4) is in the order of 0.406" and when 45 of the apertures 16 are equidistantly located around the perimeter of ring 12. In order to ensure that the critical width W of quasi rectangular slot 18 (FIG. 7) is less than the diameter D (FIG. 4) a plurality of slots of varying lengths L were formed for a corresponding plurality of rings 12 having a width S equal to approximately one half of diameter D. Good seals resulted when the quasi rectangular slot 18 was provided with a width W equal to approximately 0.233" and for slot lengths L ranging from 0.900" to 1.25". For a slot configuration having a width W equal to 0.233" and a length L equal to 0.942" twenty slots 18 provided a port area equivalent to 45 apertures 16 having a diameter D equal to 0.406" . The range in the slot thickness W was effective from 0.200" up to approximately 0.300" before it became difficult to completely encapsulate the slots within the glass envelope 10.
In order to further promote the transfer of molten glass through slot 18 a slight radius r was provided to each side. For the configuration shown in FIG. 7 wherein width W equals 0.233" and length L equals 0.942", a radius r equal to 0.125" was sufficient. High voltage vacuum interrupters manufactured from envelopes containing the shield support ring of the invention as shown in FIGS. 5, 6, and 7 were found to have superior operating characteristics since the principle source of contamination was effectively eliminated.
In order to ensure that slot 18 of FIG. 7 is completely embedded within glass envelope 10 the width W, defined herein as the minor dimension, must be equal to or less than 1/2 the glass envelope thickness G. Since the configuration 18 of FIG. 7 defines a quasi rectangular geometry, length L corresponds to the major dimension of the rectangle. In order to determine whether other configurations for slot 18 would be operable in vacuum switch devices a variety of geometric configurations were investigated wherein the major and minor dimensions were varied. The factor of merit for each configuration employed was both the number of good seals that could be provided between ring 12 and envelope 10 as well as the absence of glass contamination in the finished vacuum switch.
FIG. 8 shows the relative number of good vacuum switches 5 manufactured as a function of the ratio of the minor to major dimensions for the slot 18 of FIG. 7. When the minor dimension was small relative to the major dimension, for a ratio of minor to major dimension less than three to eight, the molten glass was cooled due to the reduced rate of flow through the slots. As a result of the lessened glass flow the vacuum switch enclosures exhibited poor seals between the flange 11, shield support ring 12 and glass envelope 10. For dimensions wherein the ratio of the minor to major dimension was greater than approximately three to four slot 18 was not completely embedded within glass envelope 10 and glass contamination occurred within the finished vacuum device. Optimum vacuum switch devices having both the least number of seal failures and the least amount of glass contamination occurred when the minor dimension was roughly one half the major dimension and when the minor dimension was roughly one half the envelope wall thickness.
FIG. 9B shows an elliptical configuration 20 wherein the minor dimension h is the "width" of the ellipse the major dimension a is the "length" of the ellipse. A rectangular configuration 19 is also shown in FIG. 9A. As discussed earlier, width W comprises the minor dimension of rectangle 19 and length L defines the major dimension. Comparing the ellipse 20 to the rectangle 19, for glass encapsulating properties, it is believed that the absence of sharp corners in the ellipse 20 provides better glass transfer during the casting process and results in less strain in the formed vacuum switch enclosure.
Although the vacuum switch shield support ring of the invention is described for use within high voltage vacuum interrupters, this is by way of example only. The shield support ring of the invention finds application wherever high vacuum devices containing the inventive ring configuration may be required. | A vacuum shield support ring for a high voltage vacuum interrupter contains a plurality of quasi rectangular openings equidistantly spaced around the ring to allow for the upward flow of glass during the vacuum interrupter envelope forming process. Complete embedment of the openings substantially reduces the occurrence of ionized particles in the finished vacuum interrupter. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a spot-type disc brake with at least one brake-shoe-actuating member disposed axially slidable in a brake caliper and adapted to be acted upon by a brake force, in particular a hydraulically actuated brake piston, and with a supporting surface taking the circumferential force which acts on the brake shoe during a braking operation.
It is known, for example, from German Patent DE-AS No. 1,251,102 to provide a pivotal connection between the brake piston and the brake pad of a fluid-pressure-actuated spot-type disc brake in order to absorb deformations of the brake members and counterbalance them so as to ensure both a perfect guiding of the brake piston and the brake pad and full engagement of the brake pad with the brake disc under all braking conditions. To this end, the ball-and-socket joint of the known spot-type disc brake, which connects the brake piston with the brake pad backing plate, is formed by a cup whose calotte-shell-shaped bottom is held in abutment with the mating calotte-shell-shaped piston end surface by means of a pin threadedly engaged with the piston and a plate-shaped disc, with a ring of an elastic material being inserted therebetween. However, the known spot-type disc brake does not permit a reduced brake fluid volume consumption during braking nor is its hydraulic efficiency increased.
In another known spot-type disc brake disclosed in U.S. Pat. No. 3,186,518, an inclined thrust member extends from a pivot point on the floating caliper substantially from the disc exit side to the brake shoe, supporting the latter diagonally. In this manner, when the brake shoe moves into engagement with the brake disc, a clamping torque is produced at the brake pad actuated by the inclined thrust member, which torque is transmitted through the floating caliper to the opposite brake shoe. In addition to the clamping force of the hydraulic piston/cylinder arrangement, a supplementary brake force is thereby generated creating a type of wedging action. In this case, a brake power assistance caused by the drag force of the brake disc is present.
SUMMARY OF THE INVENTION
In contrast thereto, it is an object of the present invention not to boost the brake force produced by the brake-shoe-actuating member but only to reduce the brake-actuation travel necessary for actuation of the brake shoes and, particularly in a hydraulic brake, to reduce the brake fluid volume consumption of the brake-shoe-actuating member during a braking operation and to thus reduce the brake pedal travel required for a braking operation.
It is a further object of this invention to improve the efficiency of, in particular, the floating caliper or floating frame hydraulic brakes.
A still further object of the present invention is to provide a simple way of restoring the clearance between the brake disc and the brake shoes following a braking operation.
A feature of the present invention is the provision of a spot-type disc brake comprising at least one brake-shoe-actuating member axially slidably disposed in a brake caliper and adapted to be acted upon by a brake force; a supporting surface disposed in the actuating member to receive a circumferential force acting upon a first brake shoe actuated by the actuating member when the first brake shoe engages an adjacent surface of a brake disc during a braking operation, the first brake shoe being spaced a given distance from the support surface in a brake release position; and an expanding device disposed between the first brake shoe and the actuating member which upon movement of the first brake shoe towards the supporting surface urges the actuating member a predetermined amount away from the first brake shoe.
The amount of travel of the brake-shoe-actuating member includes the distance required to overcome the brake clearance and the distance required to compensate for the elongation and compression of the brake components subjected to the actuating force. Thus, according to the present invention, part of this total travel is performed by the expanding device actuated by the brake shoe. The amount by which the brake shoe-actuating member is forced back by the brake shoe essentially corresponds to the brake clearance produced on brake release as a result of the return motion of the brake shoe into its initial position. Consequently, the brake-shoe-actuating member is only required to travel the actuating distance necessary for overcoming the elongations and compressions occurring within the brake system. At the beginning of a braking action, the brake-shoe-actuating member initially travels to overcome the brake clearance in order to bring the brake shoes into engagement with the brake disc. In this actuating phase, however, appreciable elongations do not yet occur because the forces are still small. Because of the movement of the brake shoe, the distance which the actuating member has covered to overcome the clearance is regained by the actuating member being shifted back a corresponding amount.
The reduction in the actuating travel of the brake-shoe-actuating member affords the substantial advantage of enabling the mechanical or hydraulic actuating device provided for driving the brake-shoe-actuating member and actuated by the vehicle operator's foot or hand, to be provided with a larger transmission ratio so that the force to be exerted by the vehicle operator becomes smaller. A further advantage achieved with the present invention is that it allows a larger brake clearance without the disadvantageous consequence of an increased actuating travel of the brake-shoe-actuating member.
While the present invention is preferably used in fixed or floating caliper hydraulic brakes, it should be understood that the present invention may also be embodied in mechanically actuated brakes.
A preferred embodiment of the present invention is characterized in that an intermediate piston is arranged between the brake shoe and the brake-shoe-actuating member, the intermediate piston being axially slidable at the brake-shoe-actuating member while in the direction of disc rotation the intermediate piston is resiliently yielding until engagement of the brake shoe or the intermediate piston with the supporting surface. A particularly compact construction may be thereby achieved by guiding the intermediate piston substantially axially in an enlarged-diameter cylinder bore of the brake-shoe-actuating member, while an elastic ring is inserted between the intermediate piston and the cylinder bore to permit the limited circumferential movement of the intermediate piston in relation to the brake-shoe-actuating member, with the supporting surface being formed by part of the wall of the cylinder bore. In this arrangement, the intermediate piston is allowed to expand in steps outside the cylinder bore in order to ensure a maximum possible engagement surface with the brake shoe.
A particularly compact and simple embodiment of the present invention includes the expanding device in the form of a thrust rod arranged between the brake-shoe-actuating member and the brake shoe in an inclined manner when viewed in the tangential plane, such that on engagement of the brake shoe with the brake disc the drag force exerted by the brake disc produces the expanding effect between the brake-shoe-actuating member and the brake shoe.
It will be particularly advantageous if the angle α at which the inclined thrust rod extends relative to the axial direction is 20°. This angle will be chosen optimally if the tangent of the angle at which the inclined thrust rod extends relative to the axial direction is smaller and preferably approximately equal to the coefficient of friction of the brake pad. It is thereby ensured that the brake shoe urges the brake-shoe-actuating member back and moves into abutment with its supporting surface. Provided that the tangent of the angle and, thus, the angle becomes smaller, the effects aimed at will be achieved, their magnitude, however, will become less with the angle decreasing. In order to obtain a maximum increase in the efficiency in the presence of a specific brake-shoe displacement travel predetermined by reasons of construction, it will be the aim to provide an angle as large as is just permissible considering the friction ratios.
Further, it is essential that the pivot point of the end of the inclined thrust rod close to the brake shoe is spaced from the axis of the brake-shoe-actuating member at least a distance equal to the distance between the brake shoe and its supporting surface. Otherwise, the thrust rod would be moved beyond the axis of the brake-shoe-actuating member and part of the achievable gains in actuating travel could be lost.
Provided that the brake-shoe-actuating member is a preferable hydraulic brake piston, the present invention provides advantageously for the intermediate piston to be arranged in a blind-end cylindrical bore of the brake piston, which is provided on both sides of the disc and has the inclined thrust rod pivotally mounted on the bottom of these blind-end bores.
If a brake piston is provided on only one side of the disc and the brake force is transmitted to the opposite side of the disc through a floating caliper, the subject of the present invention is advantageously constructed such that a blind-end cylinder device accommodating the inclined thrust rod and intermediate piston is arranged on the side of the floating caliper remote from the brake piston.
It is also essential for the embodiment of the present invention to arrange the brake shoes in the caliper tangentially slidably to enable them to follow the circumferential movement of the brake disc during braking to the degree necessary for pivotal movement of the inclined thrust rod. In the circumferential direction, the brake shoes may be resiliently supported on the brake caliper, or the brake carrier, so as to permit the circumferential movement necessary to pivot the inclined thrust rod during braking.
The elastic ring provided between the intermediate piston and the brake-shoe-actuating member acts simultaneously to somewhat elastically reset the intermediate piston and, thus, the brake shoes relative to the brake-shoe-actuating member following a braking operation, whereby a predetermined nominal clearance will be re-established.
BRIEF DESCRIPTION OF THE DRAWING
The above-mentioned and other objects and features of the present invention and the manner of obtaining them will become more apparent by reference to the following description taken in conjunction with the drawing, the single FIGURE of which is a top plan view, partially in cross section of a floating-frame or sliding-caliper spot-type disc brake in accordance with the principles of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the FIGURE, a floating frame or caliper 25 is axially slidably guided in a brake carrier 14 indicated only schematically. The guides are so arranged that brake carrier 14 is able to take the drag forces transmitted to floating caliper 25 during rotation of disc 16 in the direction of arrow F in the presence of a braking action.
Brake disc 16 has applied to one side thereof brake shoe 13 including brake pad 15 and backing plate 17 carrying the same. Brake shoe 13' including brake pad 15' and backing plate 17' carrying the same is applied to the other side of disc 16.
Brake shoes 13 and 13' are arranged within the frame opening 18 of floating caliper 25 which is constructed in the manner of a frame. Brake shoes 13 and 13' are carried by stepped intermediate pistons 19 and 19', respectively, fixedly attached thereto which have a relatively large surface in abutment with backing plates 17 and 17', respectively, and a reduced diameter portion received in bores 21 and 21', respectively. The blind-end cylindrical bore 21 is provided in a hydraulic brake piston 12 adjacent disc 16.
The reduced diameter portion of intermediate piston 19 engaged in blind-end bore 21 has an annular groove on its periphery into which an elastic ring 22 is inserted to establish the connection between intermediate piston 19 and brake piston 12.
On the surface remote from brake disc 16, intermediate piston 19 has a cup-shaped recess 20 for pivoting engagement with one end of an inclined thrust rod 11. Inclined thrust rod 11 extends from the cup-shaped recess 20 at an angle α relative to axis 23 with a tendency towards the direction of disc rotation F and terminates at the bottom of blind-end bore 21 where it is pivoted about an axis 24 perpendicular to the plane of the drawing. Here, too, thrust rod 11 may be received in a cup-shaped recess 27.
Brake piston 12 is received in a cylinder 28 adapted to be connected to a hydraulic thrust shaft or conduit constitutes a part of floating caliper 25.
On the side of brake disc 16 remote from piston 12, floating caliper 25 accommodates a blind-end cylindrical device 12' in which, similar to intermediate piston 19, an intermediate piston 19' is axially slidably guided through an elastic ring 22' while being slightly resiliently yielding in the circumferential direction. Elastic ring 22' is in abutment with its associated blind-end cylindrical bore 21'. Extending between a ball-socket-like recess 20' and bearing 24' in the bottom of blind-end cylindrical device 12' is again an inclined thrust rod 11' which is constructed similar to inclined thrust rod 11 and is arranged at an angle α relative to axis 23'.
The operation of the spot-type disc brake of the present invention is as follows.
During a braking action, brake piston 12 will be advanced in the direction of brake disc 16. As soon as brake pad 15 engages the surface of disc 16, brake shoe 13 will be somewhat entrained in the circumferential direction of disc 16, causing elastic ring 22 to be slightly compressed in the circumferential direction. As a result, inclined thrust rod 11 pivots somewhat about pivot point 24 with angle α getting smaller, which corresponds to an extension of thrust rod 11 so that piston 12 assumes the position indicated by dashed lines in the drawing. This corresponds to a reduced fluid volume consumption during braking. In this arrangement, intermediate piston 19 moves into abutting engagement with a supporting surface 30 provided on the inner wall of bore 21.
At the same time, brake shoe 13' is likewise moved into engagement with the opposite side of brake disc 16. On this side, too, there occurs a slight entrainment of brake shoe 13' in opposition to the elastic force of ring 22', whereby inclined thrust rod 11' pivots a correspondingly slight amount with angle α becoming smaller and piston 19' abutting a supporting surface 30' provided on the inner wall of bore 21'. Accordingly, there occurs also on this side a minor extension of the structure including brake-shoe-actuating member 12', brake shoe 13' and the mechanical members interposed therebetween. Thus, a reduced volume consumption is achieved on either side of brake disc 16 during braking which amounts to an improvement in the hydraulic efficiency. It is even possible to realize a negative piston travel while a suitable amount of energy is gained. This depends on the angular position of inclined thrust rods 11 and 11' and on the distance intermediate pistons 19 and 19' may cover within blind-end cylindrical bores 21 and 21' against the spring force of rings 22 and 22' in the circumferential direction during braking.
When the brake is released, a clearance is established by elastic rings 22 and 22' on both sides of disc 16 due to the elastic return motion of intermediate pistons 19 and 19'. Thus, elastic rings 22 and 22' act simultaneously in the manner of a roll-back seal.
In order to avoid that during a braking action in reverse gear, i.e., with brake disc 16 rotating in opposition to the direction of arrow f, an effect contrary to the one described hereinabove occurs, a preferred improvement of the present invention provides for stops 29 and 29' at the end of brake piston 12 and blind-end cylindrical device 21' close to the disc entry side, the stop being in contact with the end of intermediate piston 19 or 19' close to the disc entry side. Under normal braking conditions, intermediate pistons 19 and 19' are allowed to lift clear of stops 29 and 29'. In the presence of a braking action in reverse gear, however, intermediate pistons 19 and 19' are in safe engagement with stops 29 and 29', thereby effectively preventing an otherwise feared receding motion of intermediate pistons 19 and 19' into blind-end cylindrical bores 21 and 21'.
It should be understood that the subject of the present invention is also applicable to a braking action in reverse gear by arranging another inclined thrust rod between intermediate pistons 19 and 19' and the bottoms of brake-shoe-actuating members 12 and 12' at an opposite and equal angle α which is indicated in the Figure by a dashed line 11" in brake piston 12. In such an arrangement, however, inclined thrust rod 11 or 11", whichever is not currently used during a specific braking action, must be axially slidable within its pivotal mounting.
While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims. | To reduce the brake-application travel necessary for brake shoe actuation, to reduce the brake fluid volume consumption of the brake-shoe-actuating member in a hydraulic brake, to reduce the brake pedal travel required for a braking operation and to improve the efficiency of a floating caliper disc brake, there is inserted a spreading device between the brake-shoe actuating device and the brake pad connecting the circumferential travel of the brake pad caused by engagement with the brake disc into an axial displacement increasing the axial distance between the brake-shoe actuating device and the brake shoe, when the spreading device is moved out of its spring-biased central position into engagement with a supporting surface at the brake housing. | 5 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 10-2006-0102038, filed on Oct. 19, 2006, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a chip package for an image sensor and a manufacturing method thereof, and more particularly, to a chip package for an image sensor which reduces the volume of a camera module including an image sensor, a digital signal processor, a memory, and a PCB by combining the above parts into a single package, and a manufacturing method thereof.
[0004] 2. Description of the Related Art
[0005] An image sensor is a device that changes light indicating an image of an object into an electric signal for each pixel. An image sensor is used for small electronic products capable of photographing still images and motion pictures, for example, digital cameras, mobile phones, PDAs (personal digital assistants), rear view monitoring cameras included in bumpers, and interphones. The image sensor includes a charge coupled device (CCD) and a complementary MOSFET oxidized semiconductor (CMOS). The image sensor is a type of semiconductor chip.
[0006] A semiconductor chip is packaged for protection from external shocks, the environment and the exchange of electric signals with the outside. An image sensor chip is connected to a digital signal processor (DSP) to process an electric signal output from the image sensor chip and to a memory to store image information. Also, the image sensor chip is electrically interconnected to a flexible printed circuit board (FPCB) and a hard printed circuit board (HPCB) to exchange electric signals with an electronic device outside a camera module.
[0007] FIGS. 1 and 2 are sectional views showing conventional chip packages for an image sensor. Referring to FIG. 1 , an image sensor chip 1 is wire-bonded to the upper surface of an HPCB 6 via a metal wire 3 . A DSP 7 is electrically connected to the HPCB 6 by being flipchip bonded to the lower surface of the HPCB 6 . An infrared (IR) cut filter 9 to cut an unnecessary infrared ray is arranged above an image sensor 2 . Since the DSP 7 is located at the lower surface of the HPCB 6 , it is difficult to reduce the volume of the chip package so that the miniaturization of electronic products is difficult.
[0008] Referring to FIG. 2 , the image sensor chip 1 is arranged at the lowermost position of a housing 4 . A peripheral part of the upper surface of the image sensor chip 1 is electrically connected to the FPCB 8 via flip chip bonding 1 a. The DSP 7 is located at a portion of the FPCB 8 positioned outside the housing 4 . Thus, it is difficult to reduce the volume of the chip package and thereby reduce the size of an electronic product, such as a camera, containing the chip package.
SUMMARY OF THE INVENTION
[0009] To solve the above and/or other problems, the present invention provides a chip package for an image sensor which can incorporate an image sensor, a digital signal processor, a memory, and a PCB into a single package so that the volume of a camera module including the above parts is reduced, and a manufacturing method for a chip package for an image sensor.
[0010] According to an aspect of the present invention, a chip package for an image sensor comprises a first semiconductor chip having a first surface where a photographing device and a first circuit pattern are formed and a second surface that is opposite to the first surface where a second circuit pattern is formed, the first and second circuit patterns being electrically connected, a second semiconductor chip attached to the second circuit pattern, a printed circuit board facing the second surface of the first semiconductor chip and transferring an electric signal between the first and second semiconductor chips and external to the chip package for an image sensor, and a housing accommodating the first and second semiconductor chips with the printed circuit board and having an opening to allow light incident on the photographing device to pass.
[0011] The circuit patterns on the first and second surfaces of the first semiconductor chip are electrically connected by filling a through hole or a via hole formed in the first semiconductor chip with tungsten in a chemical vapor deposition method. The second circuit pattern of the first semiconductor chip is flip chip bonded to the printed circuit board so that the first and second semiconductor chips exchange an electric signal with the outside of the chip package for an image sensor. The second semiconductor chip may be a DSP chip and/or a memory chip.
[0012] Since the first semiconductor chip, the second semiconductor chip, and the printed circuit board are integrally packaged in a vertical direction, the volume of the chip package for an image sensor can be reduced. Also, since the first semiconductor chip, the second semiconductor chip, and the printed circuit board are interconnected by the flip chip interconnection, the degree of integration of the package can be increased and the electric characteristic and heat dissipation characteristic are improved.
[0013] Since an IR cut filter can be deposited on the surface of the photographing device of the first semiconductor chip, the size of the chip package for an image sensor can be further decreased.
[0014] At least a portion of the remaining space between the first semiconductor chip and the printed circuit board is filled with an electrically non-conductive material so that the shock-resistant characteristic and reliability of the chip package for an image sensor are improved.
[0015] According to another aspect of the present invention, a method of manufacturing a chip package for an image sensor comprises forming a first semiconductor chip by forming a photographing device and a first circuit pattern on a first surface of a die, forming a second circuit pattern on a second surface of the die, forming a via hole or a through hole in the die, electrically connecting the first and second circuit patterns via the via hole or the through hole, interconnecting at least one second semiconductor chip to the second circuit pattern in a flip chip bonding method, connecting the second circuit pattern on the second surface of the die to a printed circuit board, and fixing a housing having an opening through which light incident on the photographing device passes, to the printed circuit board.
[0016] The operations from the providing the first semiconductor chip to the interconnecting of the second semiconductor chip to the circuit pattern on the second surface of the first semiconductor chip are performed in a semiconductor wafer level. Thus, the time and costs for manufacturing the chip package for an image sensor are much reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
[0018] FIG. 1 is a sectional view of a conventional chip package for an image sensor;
[0019] FIG. 2 is a sectional view of another conventional chip package for an image sensor;
[0020] FIG. 3 is a sectional view of a chip package for an image sensor according to an embodiment of the present invention;
[0021] FIG. 4 is a top plan view of the chip package for an image sensor of FIG. 3 ;
[0022] FIG. 5 is a bottom plan view of the chip package for an image sensor of FIG. 3 ;
[0023] FIG. 6A illustrates a step of providing a first semiconductor chip by forming a photographing device and a circuit pattern on the upper surface of a die;
[0024] FIG. 6B illustrates a step of forming a circuit pattern on the lower surface of the first semiconductor chip;
[0025] FIG. 6C illustrates a step of forming a via hole or through hole in the first semiconductor chip;
[0026] FIG. 6D illustrates a step of electrically connecting the circuit patterns formed on the upper and lower surfaces of the first semiconductor chip;
[0027] FIG. 6E illustrates a step of electrically connecting a second semiconductor chip to the circuit pattern on the lower surface of the first semiconductor chip;
[0028] FIG. 6F illustrates a step of forming a bump on the circuit pattern on the lower surface of the first semiconductor chip;
[0029] FIG. 6G illustrates a step of electrically connecting the circuit pattern on the lower surface of the first semiconductor chip to the FPCB;
[0030] FIG. 6H illustrates a step of filling a remaining space between the first semiconductor chip and the FPCB with an electrically non-conductive material;
[0031] FIG. 6I illustrates a step of fixing the housing to the PCB; and
[0032] FIG. 6J illustrates a step of fixing the lens assembly to the housing.
DETAILED DESCRIPTION OF THE INVENTION
[0033] FIG. 3 is a sectional view of a chip package for an image sensor according to an embodiment of the present invention. FIG. 4 is a top plan view of the chip package for an image sensor of FIG. 3 . FIG. 5 is a bottom plan view of the chip package for an image sensor of FIG. 3 .
[0034] Referring to FIGS. 3 , 4 , and 5 , a chip package for an image sensor according to an embodiment of the present invention includes a first semiconductor chip 10 . A photographing device 12 is formed on the upper surface of the first semiconductor chip 10 . A predetermined circuit pattern 13 electrically connected to the photographing device 12 is formed on the upper surface of the first semiconductor chip 10 and/or inside the first semiconductor chip 10 . That is, as shown in FIG. 4 , the photographing device 12 is located at the center of the first semiconductor chip 10 and the circuit pattern including a chip bond pad 13 at the peripheral portion of the first semiconductor chip 10 . The arrangement and number of the chip bond pad 13 may diversely vary.
[0035] A filter 19 , for example, an infrared (IR) cut filter, can be formed on the photographing device 12 . The filter 19 can be deposited on the upper surface of the first semiconductor chip 10 where the photographing device 12 is located in a CVD (chemical vapor deposition) or PVD (physical vapor deposition) method. In the present embodiment, unlike the conventional technology, there is no need for the wire bonding or flip chip bonding on the upper surface of the first semiconductor chip 10 . As a result, deposition on the upper surface of the first semiconductor chip 10 is possible. Thus, since the filter 19 is not needed to be separately attached to the housing 40 above the first semiconductor chip 10 , the volume of the chip package can be reduced.
[0036] Also, predetermined circuit patterns 14 and 15 including a conductive pad 15 are formed on the lower surface of the first semiconductor chip 10 . The circuit patterns 13 on the upper surface of the first semiconductor chip 10 and the circuit patterns 14 including the chip bond pad 15 on the lower surface of the first semiconductor chip 10 are electrically connected via a via hole or a through hole. As shown in FIG. 5 , a second semiconductor chip 20 , for example, a digital signal processor (DSP) chip 21 and/or a memory chip 22 , is electrically connected to a predetermined chip bond pad 15 of the circuit patterns 14 and 15 on the lower surface of the first semiconductor chip 10 . As a result, an electric signal output from the photographic device 12 through the conductive pad 15 is transferred to the DSP chip 21 and/or the memory chip 22 . Also, a flexible printed circuit board (FPCB) 30 is electrically connected to the chip bond pad 15 . As a result, the photographing device 12 , the DSP chip 21 , and the memory chip 22 can exchange electrical signals with external parts.
[0037] The electric connection can be made in a variety of methods, preferably, in a flip chip bonding method. Also, the electric connection can be made in a tape automated bonding (TAB) method. That is, the first semiconductor chip 10 and the second semiconductor chip 20 are integrally deposited in a vertical direction. Thus, the volume of the chip package can be reduced. Also, the flip chip bonding has the following merits. That is, when the first semiconductor chip 10 and the second semiconductor chip 20 are coupled in the flip chip interconnection method, 1) eliminating bond wires reduces the required board area and requires far less height (smallest size), 2) flip chip offers the highest speed electrical performance (highest performance), 3) flip chip gives the greatest input/output connection flexibility (greatest I/O flexibility), 4) flip chip, when completed with an adhesive “underfill”, are solid little blocks of cured epoxy so that flip chip is mechanically the most rugged interconnection method (most rugged), and 5) flip chip can be the lowest cost interconnection for high volume automated production (lowest cost).
[0038] Furthermore, passive devices (not shown) such as capacitors, resistors, and coils can be mounted to be electrically connected to the lower surface of the first semiconductor chip 10 . As the method of electrically connecting the passive devices to the lower surface of the first semiconductor chip 10 , in addition to the method of mounting individual passive devices, a method of integrating the passive devices on the lower surface of the first semiconductor chip 10 in the form of a thin film or a thick film can be used.
[0039] A bump 16 is formed on the chip bond pad 15 of the circuit patterns 14 and on the lower surface of the first semiconductor chip 10 . The bump 16 is a conductive protrusion that can electrically connect the first semiconductor chip 10 to the circuit patterns 14 including the chip bond pad 15 in the flip chip interconnection or TAB method. The bump 16 is formed of a metal material such as gold (Au), solder, copper (Cu), conductive resin in which metal particles are mixed in resin, or a resin-metal composition material in which the metal material is coated on a resin surface. The position and number of the bump 16 are variable.
[0040] The bump 16 and a conductive pad 31 of the FPCB 30 are electrically connected in the flip chip bonding method. Consequently, the first semiconductor chip 10 , the second semiconductor chip 20 , and the FPCB 30 are integrally deposited in a direction from the upper surface toward the lower surface. Thus, the volume of the chip package for an image sensor can be reduced.
[0041] A space between the lower surface of the first semiconductor chip 10 and the FPCB 30 can be filled with underfill. Thus, the shock-resistant characteristic and reliability can be improved.
[0042] The housing 40 is coupled to the upper surface of the FPCB 30 to encompass the first semiconductor chip 10 and the second semiconductor chip 20 . The upper side of the housing 40 is open. Screw threads are formed on the inner circumferential side of the upper portion of the housing 40 so that a lens assembly 45 can be screw coupled to the upper portion of the housing 40 . Thus, the housing 40 protects the chip package for an image sensor from external shocks and environment and keeps sealing. A series of lenses, a barrel, and a zooming actuation member are coupled to the lens assembly 45 .
[0043] According to the above structure, the chip package for an image sensor according to an embodiment of the present invention can be packaged to take less volume so that the volume of a camera module can be reduced much. As a result, the size of an electronic product having a camera module can be further reduced.
[0044] A method of manufacturing the chip package for an image sensor according to an embodiment of the present invention is described below with reference to FIGS. 6A through 6J .
[0045] FIG. 6A illustrates a step of providing the first semiconductor chip 10 by forming the photographing device 12 and the circuit pattern 13 on the upper surface of a wafer die 11 . Referring to FIG. 6A , the first semiconductor chip 10 is made from a silicon wafer. That is, the photographing device 12 is formed by processing the upper surface of the wafer die 11 , for example, by selectively repeating a film forming process, a film patterning process, and an impurity doping process several times. The circuit pattern 13 is formed for wiring of the photographing device 12 . The circuit pattern 13 is generally formed in a masking process after forming an aluminum thin film. The aluminum thin film can be formed, for example, in the PVD process. Also, a passivation layer (not shown) is further provided to protect the circuit pattern ( 13 ) layer. The step shown in FIG. 6A can be performed in a semiconductor wafer level as shown in FIG. 4 .
[0046] After the step shown in FIG. 6A is complete, a step of grinding the lower surface of the wafer die 11 is additionally performed. This process is needed to make the wafer to have an appropriate thickness because the wafer is initially formed to be thick to easily handle the wafer during the process of forming the photographing device 12 in the wafer die 11 . However, this grinding step is not necessary. In addition, a protection film can be formed to completely insulate the grinded lower surface of the wafer die 11 .
[0047] Although it is not shown in the drawings, after the above step, a step of further forming the filter 19 , for example, an IR cut filter, on the surface of the photographing device 12 of the first semiconductor chip 10 may be provided. The filter 19 can be deposited in the CVD or PVD method on the upper surface of the first semiconductor chip 10 where the photographing device 12 exists. When the filter 19 is not deposited on the upper surface of the first semiconductor chip 10 , the filter 19 can be fixedly provided inside the housing 40 .
[0048] FIG. 6B illustrates a step of forming the circuit patterns 14 and 15 on the lower surface of the first semiconductor chip 10 . Referring to FIG. 6B , the circuit patterns 14 and 15 on the lower surface of the first semiconductor chip 10 can be formed in the same method as that used for forming the circuit pattern 13 on the upper surface of the first semiconductor chip 10 . A passivation layer (not shown) to protect the circuit patterns 14 and 15 can further be formed. The step shown in FIG. 6B can be performed in the semiconductor wafer level.
[0049] FIG. 6C illustrates a step of forming a via hole or through hole 17 in the first semiconductor chip 10 . The hole 17 can be formed using mechanical drilling or laser drilling. The step shown in FIG. 6C can be performed in the semiconductor wafer level.
[0050] FIG. 6D illustrates a step of electrically connecting the circuit patterns 13 and 15 formed on the upper and lower surfaces of the first semiconductor chip 10 . In this step, tungsten 18 is deposited in the via hole or through hole 17 in the CVD method or copper 18 is plated on the via hole or through hole 17 in an electro copper plating method. Thus, the circuit pattern 13 on the upper surface of the first semiconductor chip 10 and the circuit patterns 14 and 15 on the lower surface of the first semiconductor chip 10 are electrically connected. Since the hole forming method or interlayer electric connection method is well known, a detailed description thereof will be omitted herein. The step shown in FIG. 6D can be performed in the semiconductor wafer level.
[0051] FIG. 6E illustrates a step of electrically connecting the second semiconductor chip 20 to the circuit patterns 14 and 15 on the lower surface of the first semiconductor chip 10 . The second semiconductor chip 20 may be the DSP chip 21 or the memory chip 22 . Also, in the second semiconductor chip 20 that is electrically connected, any one or both of the DSP chip 21 and the memory chip 22 can be mounted on the first semiconductor chip 10 .
[0052] The second semiconductor chip 20 can be electrically connected to the circuit patterns 14 and 15 on the lower surface of the first semiconductor chip 10 in the flip chip bonding or TAB method. To this end, a bump 25 is formed on the conductive pad of the second semiconductor chip 20 . The bump 25 can be formed by many methods including, but not limited to, an evaporation method, an electroplating method, an electroless plating method, a screen printing method, a solder ball mounting method, a stud method, a needle-depositing method or a Super-Juffit method.
[0053] The second semiconductor chip 20 where the bump 25 is formed is arranged on the lower surface of the first semiconductor chip 10 and bonded in a direct attachment method. The direct attachment method may be a flip chip bonding, TAB or other method. According to the flip chip bonding method, the second semiconductor chip 20 is flipped such that the upper surface of the second semiconductor chip 20 faces the lower surface of the first semiconductor chip 10 and the bump 25 of the second semiconductor chip 20 is directly attached to the conductive pad of the lower surface of the first semiconductor chip 10 . The flip chip bonding method can be performed using an anisotropic conductive film (ACF), a non-conductive paste (NCP), or a non-conductive film (NCF). In addition, the flip chip bonding method can be performed by a solder combination, a heat-pressure combination, a thermosonic combination. The step shown in FIG. 6E can be performed in the semiconductor wafer level.
[0054] FIG. 6F illustrates a step of forming the bump 16 on the circuit pattern 15 on the lower surface of the first semiconductor chip 10 . The bump ( 16 ) forming method is similar to the above-described bump ( 25 ) forming method. The size of the bump 16 formed on the lower surface of the first semiconductor chip 10 can be appropriately adjusted such that the second semiconductor chip 20 is not located lower than the level of the lowermost portion of the bump 16 . That is, the bump 16 formed on the lower surface of the first semiconductor chip 10 not only works as a device for electrically connecting the first semiconductor chip 10 and the FPCB 30 , but also adjusts the height of the chip package for an image sensor to accommodate the second semiconductor chip 20 in a space between the first semiconductor chip 10 and the FPCB 30 .
[0055] FIG. 6G illustrates a step of electrically connecting the circuit pattern 15 on the lower surface of the first semiconductor chip 10 to the FPCB 30 . The electric connection can be formed using a flip chip bonding, TAB or other method. The steps shown in FIGS. 6F and 6G can be performed in the semiconductor wafer level.
[0056] That is, the steps shown in FIGS. 6A through 6G can be performed in the semiconductor wafer level. Then, after sawing or singularizing the wafer die 11 , the remaining steps can be performed. As a result, lots of steps of the chip packaging for an image sensor can be performed in the wafer level so that the manufacturing steps can be performed quickly and the manufacturing cost can be reduced.
[0057] FIG. 6H illustrates a step of filling underfill in a space between the first semiconductor chip 10 and the FPCB 30 . After the first semiconductor chip 10 and the FPCB 30 are electrically connected to each other, the underfill is performed to fill the space therebetween. The underfill can be flow, no-flow, wafer level or other type. In the present embodiment, thermosetting sealant is dispensed to the side surface of the first semiconductor chip 10 so that the sealant permeates through the space according to a capillary phenomenon. Then, as the sealant is cured, the shock-resistant characteristic and reliability of the chip package for an image sensor can be improved.
[0058] FIG. 6I illustrates a step of fixing the housing 40 to the PCB 30 . A variety of methods can be used for this purpose. For example, sealant (not shown) is dispensed around the upper surface of the FPCB 30 . The housing 40 is arranged and placed on the FPCB 30 to fit to a sealant coating portion. By curing the sealant, the housing 40 is firmly fixed to the FPCB 30 .
[0059] FIG. 6J illustrates a step of fixing the lens assembly 45 to the housing 40 . The upper portion of the housing 40 is open and screw threads are formed on the inner circumferential surface of the upper portion of the housing 40 . The lens assembly 45 is screw coupled to the screw threads. Thus, the photographing device 12 and the DSP chip 21 are integrally packaged in the housing 40 and the FPCB 30 so that the chip package for an image sensor is complete.
[0060] In particular, the chip package for an image sensor according to the embodiment shown in FIG. 6J is effective in reducing the volume by integrating the first semiconductor chip 10 , the second semiconductor chip 20 , and the FPCB 30 in the vertical direction in the flip chip bonding method. Also, since the IR cut filter 19 is deposited on the upper surface of the first semiconductor chip 10 , the volume of the chip package for an image sensor can be further reduced. In addition, since a lot of steps can be performed in the wafer level, the manufacturing time and costs can be reduced.
[0061] While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | A chip package for an image sensor includes a first semiconductor chip having a first surface where a photographing device and a first circuit pattern are formed and a second surface that is opposite to the first surface where a second circuit pattern is formed. The first and second circuit patterns are electrically connected. The chip package further includes a second semiconductor chip attached to a second circuit pattern on the second surface of the first semiconductor chip. A printed circuit board faces the second surface of the first semiconductor chip and transfers an electric signal between the first and second semiconductor chips and externally. A housing accommodates the first and second semiconductor chips. The housing allows light to pass through to the photographing device. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(a) to Australian Patent Application Serial Number 2015101431 filed Oct. 1, 2015 entitled “A QUILT THAT CAN BE PURCHASED IN TWO SEPARATE PARTS AND JOINED TOGETHER” the entirety of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to a “Quilt” (which is also known as a Duvet, or Doona, depending on the country, or origin of the individual, but herein shall be termed a “Quilt”) that is formed in two individual halves (that for the purposes of this application shall be known as “Parts” in order to differentiate from segments of the Quilt) and which can be joined together, no matter what “Part” is selected, allowing for an independent choice of thermal resistance for an individual for their side of the bed.
[0003] For many years “Quilts” have been styled in a manner to cover the whole of the bed surface in one piece. This creates a consistent warmth, or thermal resistance, across the bed, and presents an even cover on the top of the surface of the bed. However as people are of different warmths or body temperatures i.e. one person can be colder than the other person, this can make for a disturbing night's sleep for one, or both parties. One person could feel that a covering provides a perfect temperature whilst the other person could be too hot, or too cold. Previous attempts at manufacturing “Quilts” in different portions, relied on conventional methods of joining them together say by zip, or buttons. However as the joining mechanism was not reversible to provide both a negative and positive section on each “Part” of the “Quilt.” The Parts of the prior art Quilts could not be provided (e.g. sold) separately, and this therefore limited the number of variations that could be applied to suit an individual, making such Quilts difficult to market as up to 250 combinations or more in each size could be needed if allergies, thermal resistance variations, and preference of the filling were taken into account.
DESCRIPTION OF THE INVENTION
[0004] The present invention is designed to eradicate this problem by offering a choice of warmth for each party sharing the same bed, and giving them a level of thermal resistance on their chosen side of the bed that is more suitable to them, independently, at the time of selection, whether it be cooler, or warmer than the other half. Likewise each party can have an independent choice of filing even if the level of thermal resistance is identical to the other Party. Both “Parts” are then joined together to make up one whole “Quilt”.
[0005] Thus the present invention provides a quilt comprising: first and second quilt parts, wherein each quilt part has a thermal resistivity and the thermal resistivity of the first quilt part is different to the thermal resistivity of the second quilt part, and wherein each part has uppermost and lowermost surfaces and a channel wall disposed art a peripheral end of the quilt part, wherein the channel wall consists of a flat surface that extends between respective peripheral ends of the uppermost and lowermost surfaces of the quilt part and is orientated substantially perpendicular to the uppermost and lowermost surfaces; and has a plurality of hook or loop fasteners disposed on the surface, whereby, the hook or loop fasteners disposed on the flat surface of the channel wall of the first quilt part are releasably attachable to the hook or loop fasteners disposed on the flat surface of the channel wall of the second quilt part for releasably attaching the two quilt parts together.
[0006] Optionally, the flat surface of the channel wall of each quilt part comprises; A first surface section having a plurality of hook fasteners disposed on the first surface section; and a second surface section having a plurality of loop fasteners on the second surface section.
[0007] Optionally, each quilt part has one or more attachment means disposed on the uppermost and lowermost surfaces of the quit part, each attachment means being adapted to attach the quilt releasably to an overlying or underlying quilt part.
[0008] Conveniently at least one of the attachment means comprises hook or loop fasteners. Alternatively, at least one of the attachment means comprises a zip.
[0009] The levels of warmth can be determined by either a “Tog Rating” being allocated to each “Part” of the “Quilt”, or by colour coding the warmth in grades of thermal resistance, or both. No matter what type of Part is selected it will always join to the other Part to form a whole Quilt as is set out in the figures shown.
[0010] The Quilt according to the present invention can be formed in two “Parts” Each {art can be formed in a single piece or can comprise two segments (herein segments may also be termed “Portions”) utilizing the “Four seasons” method. (The “Four Seasons” method is a design in the market place that separates the covering into layers allowing for one “portion” to be separated from another to vary the thermal resistance for winter, or summer or vary again for autumn and spring.) After the two separate “Parts” of the “Quilt” are joined together it then completes the “Quilt”. The joining mechanism can be either, but not restricted to, zips, buttons, hook and loop fasteners, studs, etc. How the two Parts are fastened together is not important, but rather the fact that the “Quilt” can be purchased in two separate “Parts” of varying qualities, such as thermal resistance, and can be linked together with another “Part” whether it be heavier, lighter, warmer, or cooler, or using a different material. Any suitable material can be used, including, but not restricted to, wool, feather, down, polyethylene terephthalate, polyester, microfibre, cotton or a mixture of such materials. the two Parts will always join together as long as the two “Parts” are manufactured in the same manner, is the concept described herein.
[0011] The method of manufacture that is demonstrated herein is preferred due to its ease of manufacture, and functionality. For instance a 500 gram per square metre wool “Quilt” “Part” joined with a 300 gram per square metre Wool “Quilt” “Part”, would be substantially warmer than the latter “Part” and also heavier, giving the person on that half of the “Quilt”, a higher amount of thermal resistance than the other person on the side where the 300 gram per square metre wool “Part”, is used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention is further described with reference to the figures in which:
[0013] FIG. 1 is a schematic representation of a portion of a Quilt Part according to one embodiment of the present invention and shows the channel wall within the Part.
[0014] FIG. 2 is a schematic representation of a portion of a traditional quilt.
[0015] FIG. 3 is a schematic representation of two Parts of a Quilt according to the present invention.
[0016] FIG. 4 shows a detailed view of the area shown circled in FIG. 3 ;
[0017] FIG. 5 is a schematic representation of a further embodiment of a Quilt According to the present invention in the “Four Seasons” style; and
[0018] FIG. 6 shows a detailed view of the area shown circled in FIG. 5 .
DETAILED DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows a portion of a “Quilt” ( 7 ) according to the present invention with channel walls ( 3 ), being present to assist the loft or thickness of a “Quilt”, making it appear fluffier or fuller, and to assist in a more even thermal resistance across the “Quilt”. Thus, rather than the stitching going through from the top to the bottom of the “Quilt” (see FIG. 2 ), like tradition “Quilts”, a strip of material ( 3 ) (herein referred to a “channel wall”) is sewn ( 4 ) into each “Channel” of the “Quilt”, thereby joining the top ( 5 ) to the bottom ( 6 ) at regular intervals across the quilt ( 7 ). This arrangement allows for more fill to be placed in to the channel, prevents the fill from being displaced within the interior during use, and leaving the surfaces ( 5 , 6 ) of the Quilt flatter in appearance.
[0020] FIG. 2 depicts a traditional “Quilt” with the stitching sewn through from the top fabric through to the bottom fabric to form a “Channel” for the filling of the “Quilt” to be inserted. As you can plainly see in this Figure a less even surface results, and due to the stitching going through from the top to bottom less, or no fill is within this area leaving it with less thermal resistance.
[0021] FIG. 3 illustrates the preferred form of manufacture as its ease to be made, and its ability to be utilized is the simplest form known to me. FIG. 3 shows one “Part” ( 9 ) of the “Quilt”, which is formed independently from a separate Part ( 10 ) of the Quilt. Parts ( 9 , 10 ) can be joined together in the middle through a hook and loop fastener, which is sewn into the length of the joining “Channel Wall” ( 15 ) on each of the Quilt Parts ( 9 , 10 ). In each of Parts ( 9 , 10 ), one half of the “Channel Wall” ( 15 ) is sewn with a loop fastener tape ( 11 , 12 ), and the other half of each Channel Wall for Parts ( 9 , 10 ) is sewn with a hook fastener tape ( 13 , 14 ). (See inset FIG. 4 for a closer view). Therefore, as long as both Parts ( 9 , 10 ) are manufactured in the same way each “Part” will always join up with another “Part” to form a “Quilt”, irrespective of the thermal qualities or material used to make a “Part.” For instance a 500 gram per square metre Wool “Quilt”“Part”, joined with a 300 gram per square metre Wool “Quilt”, “Part”, would be substantially warmer than the latter “Part”, and also heavier, giving the person using that “Part” of the “Quilt”, a higher amount of thermal resistance than the other person on the side where the 300 gram per square metre Wool “Quilt” “Part”, is used.
[0022] FIG. 4 shows detail of the edge of the joining “Channel Wall” ( 15 ) as shown in FIG. 3 for “Part” ( 10 ) of the “Quilt”. FIG. 4 shows that the centre of the “Channel” wall ( 15 ), at the location where the hook tape ( 18 ) meets with the loop tape ( 16 ), Each “Part” of each “Quilt” is made this way so no matter what “Part” is purchased they will always join together by simply rotating one “Part” of the “Quilt” to join up with the other “Part” in the middle. All joining mechanisms such as zips, etc. can be made this way, although using the hook and look tape is the easiest form of manufacture The top of the “Part” ( 17 ) of the “Quilt” is also shown.
[0023] FIG. 5 shows a “Four Seasons” type “Quilt” according to the present invention, showing all “Portions” ( 19 , 31 , 28 , 29 ) being joined by hook and Loop tabs. As illustrated, Hook Tabs are sewn into the bottom of the Top ( 26 ) “Portions” ( 31 & 29 ), and Loop Tabs are sewn into the top of the bottom ( 27 ) “Portions” ( 19 & 28 ), but the converse arrangement is also possible. Other forms of joining the portion together can also be used but this form of manufacture is preferred both for ease of manufacture and also ease of use. A lower “Portion” is joined to its corresponding upper ( 28 & 29 ; 19 & 31 ), or can be left as a single “Portion” depending on the required warmth for form a Part. Thus Portions ( 28 , 29 ) can be joined together to form Part ( 21 ), or either of Portions { 28 , 29 ) can be individually used as Part ( 21 ). A corresponding arrangement exists for Portions ( 19 , 31 ) which independently or together for Part 20 . Each “Part” ( 20 & 21 ) of the “Quilt” is then joined together in the middle through a Hook and Loop Fastener, which is sewn into the length of the joining “Channel Wall” that make up each “Part” ( 20 & 21 ) of the “Quilt” where a “Part” ( 20 or 21 ) is formed from two Portions, each Portion will include a Hook And Loop Fastener, as appropriate. One half of the “Channel Wall” is sewn with a loop fastener tape ( 23 & 25 ), and the other half is sewn with a hook fastener tape ( 22 & 24 ) Thus, no matter which “Part”( 20 & 21 ) is purchased it will always join up with the other “Part” ( 21 & 21 ) of a “Quilt”, as long as they are both manufactured in this same way. For that matter each top “Portion” ( 31 , 29 ) of each “Part” ( 20 & 21 ) of the “Quilt”, will always join with each other top “Portion” ( 31 , 29 ) of the “Quilt” and likewise for each bottom portion. This allows three variations allowing a high degree of adjustment to cover all seasons. As an example, “Portion” ( 31 ) may be, but not restricted to, a 350 gram per square metre wool “Portion” of the “Part” ( 20 ) of the “Quilt”, and “Portion” ( 19 ) maybe, but not restricted to, a 150 gram per square metre “Portion” of the “Part” ( 20 ) of the “Quilt”, which would be more suitable for summer. Joined together as the full “Part” ( 20 ) they would be 500 grams per square metre, suitable for winter. “Part” ( 21 ) however could be somewhat cooler consisting of a “Portion” ( 29 ) which maybe, but not restricted to a 200 gram Polyethylene Terephthalate “Portion”, and “Portion” ( 28 ) maybe, but not restricted to a 150 gram per square metre Polyethylene Terephthalate “Portion” making it substantially cooler than “Part” ( 20 ) of the “Quilt”. Portion ( 28 ) could also be exchanged to replace “Portion” ( 19 ) increasing the variables in thermal resistance even further which could be useful when an individual has a fever on one side of the bed.
[0024] FIG. 6 shows the edge joining “Channel Walls” as one Part ( 21 ) of the embodiment illustrated in FIG. 5 in detail. Channel Wall ( 30 ) of FIG. 5 of both Portions ( 28 & 29 ) is sewn with both Hook Tape ( 34 & 36 ) to the middle of the joining “Channel Wall” ( 30 ), and Loop tape ( 37 & 38 ) sewn to the middle of the joining “Channel Wall” ( 30 ). All “Portions” ( 31 , 19 , 28 , & 29 ) of the embodiment in FIG. 5 are sewn in this manner so they will always join with another “Part” or “Portion”, no matter what “Part” or “Portion” is selected as long as it is manufactured in the same manner. A Loop Tab ( 39 ) is sewn into the top of the bottom “Portion” ( 29 in FIG. 5 ; 33 in FIG. 6 ), and a Hook Tab is sewn into the bottom of the top “Portion” ( 29 in FIG. 5 ; 33 in FIG. 6 ) indicated with dotted lines as it is obscured from view ( 32 ), to join the two “Portions” ( 28 , 29 , of FIG. 5 ) together, increased variations in thermal resistance can be obtained by adding additional Hook and Loop Fastener tabs on each “Portion” so the Bottom and Top of each “Portion” are identical in either Hook Tabs or Loop tabs, making each “Portion” and “Part” interchangeable in all combinations if need be. | The disclosed “Quilt” is in two “Parts”, each Part having a level of insulation which is independent of the other Part. For example, one “Part” can be extremely warm, and the other “Part” can be extremely cool. Both “Parts” can then be joined together to form a “Quilt”. When juxtaposed the two separate “Parts” of the “Quilt”, are a reverse image of each other, sharing both Negative and Positive componentry of a joiner. In this instance a Hook and Loop fastener is sewn into the joining “Channel Wall” of each “Part”. The Hook Fastener tape is sewn along one half of the edge of the joining “Channel Wall” to the middle of the “Channel Wall”, and the other half of the joining “Channel Wall” is sewn with a Loop Fastener tape. This arrangement permits both “Parts” can be purchased separately, and joined together allowing the individual to choose their own level of thermal resistance independently, whilst still being joined up with another individual's chosen thermal resistance. | 0 |
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to fan wheels of centrifugal and axial fans such as blowers, exhaust fans and the like, impellers of pumps, steam and gas turbine rotors and fan wheels attached to generators and motors for cooling them and more particularly wheels or rotors with a plurality of blades especially adapted for use in rotary machines which must be operated with less noise and less vibrations.
2. BRIEF DESCRIPTION OF THE PRIOR ART
When a fan wheel is rotated, the noise is produced from the fan wheel itself or from a machine incorporating the fan wheel. Most unpleasant is the fan noise associated with the number of blades. In order to control the fan noise, there has been proposed a fan wheel or the like wherein a plurality of blades are arranged at irregular or unequal pitch angles. However the irregular or unequal pitch angles have been determined mainly in dependence upon the intuition and no satisfactory theory has been established which may obtain an optimum set of irregular or unequal pitch angles of blades so that the fan noise may be suppressed to a minimum level. In addition, the irregular or unequal pitch angle arrangement of blades inevitably gives rise to the inherent problem how to attain the mechanical balance of the fan wheel at the same time. Again so far no satisfactory theory to solve this problem has been proposed yet.
For instance, consider a blade arrangement wherein 12 blades are divided into four sets each consisting of three blades spaced equiangularly and the adjacent sets are circumferentially spaced apart from each other by a suitable angle, whereby the blades may be arranged at irregular or unequal pitch angles. This arrangement serves to attain the mechanical balance of the fan wheel, but will not suppress the unpleasant fan noise sufficiently because each set of three blades would act as an equally pitched fan. Thus it has been extremely difficult to attain a compromise between the irregular or unequal pitch angle arrangement of blades and the attainment of satisfactory mechanical balance of the fan wheel.
SUMMARY OF THE INVENTION
Accordingly, the primary object of the present invention is to provide a wheel or rotor with a plurality of blades arranged at irregular or unequal pitch angles circumferentially of a disk, a hub or the like which may substantially overcome the above and other problems encountered in the prior art, whereby the operation with less noise and less vibrations may be ensured.
To the above and other ends, the present invention provides a wheel or rotor with a plurality of blades arranged at irregular or unequal pitch angles circumferentially of a disk, a hub or the like, wherein the characteristic level e k representative of the order-of/ harmonic characteristic of blade pitch is defined by
e.sub.k =10 log.sub.e d.sub.k =100 (1)
where ##EQU3## z=a number of blades k=1,2, . . . and n; n≧Z
θ j =the angular position of the tip or root of each blade defined in terms of a central angle subtended at the center of a circle, whose center coincides with the axis of the wheel or rotor and on which all the tips or roots of the blades are positioned, by an arc extended from a reference point on said circle to said tip or root of each blade, j=1,2, . . . and Z; and
the characteristic level e k satisfies the following conditions ##EQU4## where
e=-13.14 log.sub.10 Z+99.70 (4)
K=2,3, . . . n
d k obtained from Eq. (1') represents the magnitude of an order component obtained by the analysis of rotation order ratios of impulse signals generated at a point near to the path of the tips of blades of a fan wheel when the latter is rotated at a steady rotational speed. Eq. (1) represents the magnitude of the order component d k in terms of dB. The constant 100 in Eq. (1) is arbitrarily selected so as to facilitate to handle or process the characteristic level e k . It follows therefore that the constant is not limited to 100, but any suitable values may be selected, but the values 35 and 65 in Eq. (2) as well as the constant 99.70 in Eq. (4) must be incremented or decremented depending upon a newly selected constant in Eq. (1).
Eq (2) must be satisfied in order to attain a satisfactory mechanical balance of the fan wheel in practice even though the blades are arranged at irregular or unequal pitch angles. Eq. (3) must be satisfied in order to flatten the frequency characteristic curve of the fan noise and to reduce the level of the fan noise. Eq. (4) is an empirical equation obtained from the extensive calculations and experiments conducted by the inventors.
According to the present invention, the noise from a fan wheel or the like and/or a machine incorporating a fan wheel or the like may be considerably suppressed. In addition, even though the blades are arranged at irregular or unequal pitch angles, an almost perfect mechanical balance may be ensured so that mechanical vibrations may be suppressed to a minimum.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of some preferred embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic front view of a fan wheel which is a first embodiment of the present invention;
FIG. 2 shows the order characteristic of the blade pitch thereof;
FIG. 3 is a schematic front view of an impeller which is a second embodiment of the present invention;
FIG. 4 shows the order characteristic of the blade pitch thereof;
FIG. 5 is a schematic front view of an exhaust fan which is a third embodiment of the present invention;
FIG. 6 shows the order characteristic of the blade pitch thereof;
FIG. 7 is a schematic front view of a turbine wheel or rotor which is a fourth embodiment of the present invention; and
FIG. 8 shows the order characteristic of the blade pitch thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment, FIGS. 1 and 2
In FIG. 1 is shown a first embodiment of the present invention which is applied to a fan wheel for cooling an AC generator of an automotive vehicle. The fan is a centrifugal turbofan. A fan wheel 10 comprises a disk 13 and a plurality (13 in this embodiment) of blades 12 arranged at irregular or unequal pitch angles circumferentially of the disk 13. The blades 12 are straight in cross section.
The radially outward ends; that is, the roots of the blades 12 are located at points p 1 , p 2 , . . . and p 13 on a circle 16 whose center is the axis 15 of the fan wheel 10. The pitch angles of the blades 12 are expressed in terms of the central angles θ 1 ', θ 2 ', . . . , and θ' 13 subtended at the center 15 of the circle 16 by arcs p 1 p 2 , p 2 p 3 , . . . and p 13 p 1 , respectively. In the first embodiment, the pitch angles are θ' 1 =26.0°, θ' 2 =21.1°, θ' 3 =34.2°, θ' 4 =57.5°, θ' 5 =8.5°, θ' 6 =8.4°, θ' 7 =46.3°, θ' 8 =18.8°, θ' 9 =31.7°, θ' 10 =24.1°, θ' 11 =42.7°, θ' 12 =32.3° and θ' 13 =8.4°. In order to determine the angular positions θ 1 , θ 2 , θ 3 . . . θ 13 of the blades any point on the circle 16 may be selected as a reference point, but in the first embodiment shown in FIG. 1, the point p 1 is selected as a reference point. Therefore, θ 1 =0°, θ 2 =θ 1 ', θ 3 =θ 1 +θ' 2 ans so on. The order-of-harmonic characteristic of the blade pitch of the fan wheel 10 is shown in FIG. 2.
The fan wheel 10 with the above proportions has the blade angular positions θ 1 , θ 2 , θ 3 . . . and θ 13 which satisfy Eq. (2) and Eq. (3), because when Z=13, e=85.1 dB from Eq. (4). That is, the fan wheel 10 is mechanically well balanced. Furthermore the blade noise may be considerably suppressed in unpleasant quality and sound pressure level. Experiments show that when the prior art fan wheel with irregular or unequal blade pitches for an AC generator is replaced with the fan wheel of the proportion described above, the fan noise is reduced by about two phones at a position spaced apart by 30 cm from the generator.
The first embodiment may ensure the reduction in fan noise in the order of harmonics from 1st to 26th. In order to attain a further suppression of fan noise, the highest order n may be further increased and the pitch angles of the blades may be obtained which satisfy Eqs. (2) and (3). It is possible to obtain such pitch angles by making calculations.
Second Embodiment, FIGS. 3 and 4
In FIG. 3 is shown a second embodiment of the present invention which is applied to an impeller of a centrifugal pump. An impeller 20 comprises a disk 23 and twelve blades 22 arranged at irregular or unequal pitch angles circumferentially of the disk 23. The radially outward ends of the blades 22 are located at points p 1 , p 2 , . . . and p 12 on a circle 26 whose center is the axis 25 of the impeller 20. As with the first embodiment, the pitch angles are defined by the central angles θ 1 ', θ 2 ', . . . and θ' 12 subtended at the center 25 of the circle 26 by the arcs p 1 p 2 , p 2 p 3 , . . . , and p 12 p 1 . That is, θ' 1 =25.7°, θ' 2 =37.1°, θ' 3 =23.9°, θ' 4 =13.0°, θ' 5 =36.8°, θ' 6 =51.0°, θ' 7 =17.0° , θ' 8 =25.4°, θ' 9 =38.1°, θ' 10 =29.4°, θ' 11 =9.8° and θ' 12 =52.0°. The reference point of the blade angular positions θ 1 , θ 2 , . . . and θ 12 is the point p 1 and consequently the blade angular positions are θ 1 =0°, θ 2 =θ' 1 , θ 3 =θ' 1 +θ' 2 and so on as with the case of the first embodiment. The order-of-harmonic characteristic of the blade pitch of the impeller 20 is shown in FIG. 4.
The blade angular positions θ 1 , θ 2 , . . . and θ 12 of the impeller 20 also satisfy Eq. (2) and Eq. (3), because when Z=12, e=85.5 dB from Eq. (4). The impeller 20 is mechanically well balanced. Furthermore, pulsations in hydraulic pressure due to the rotation of the impeller 20 may be reduced so that the sound pressure level of the vibration noise due to the liquid column vibration in the piping of the pump may be reduced.
Third Embodiment, FIGS. 5 and 6
In FIG. 5 is shown a third embodiment of the present invention which is applied to an exhaust fan with a large volume. The exhaust fan is an axial or propeller fan and has a fan wheel 30 comprising a disk 33 and five blades 32 arranged at irregular or unequal pitch angles circumferentially of the disk 33. The middle points of the radially inward ends of the blades 32 are located at points p 1 , p 2 . . . p 5 on a circle 36 whose center is the axis of 35 of the fan wheel 30. The pitch angles of the blades 32 are also defined in terms of the central angles θ 1 ' through θ' 5 subtended at the center 35 of the circle 36 by the arcs p 1 p 2 through p 5 p 1 . That is, θ' 1 =52.5°, θ' 2 =71.2°, θ' 3 =96.8°, θ' 4 =31.3° and θ' 5 =108.2°. The reference point to the blade angular positions θ 1 through θ 5 is also the point p 1 . Therefore the blade angular positions are also defined as θ 1 =0°, θ 2 =θ 1 ', θ 3 =θ 1 '+θ 2 ' and so on. The order-of-harmonic characteristic of the blade pitch of the fan wheel 30 is shown in FIG. 6.
The blade angular positions θ 1 , θ 2 . . . θ 5 of the fan wheel 30 also satisfy Eq. (2) and Eq. (3), because when Z=5, e=90.5 dB from Eq. (4). The fan wheel 30 is mechanically well balanced. Furthermore the fan noise is considerably suppressed in both sound pressure level and unpleasant quality. The third embodiment may ensure the fan noise suppression from the first order to the 10th order of harmonics. The suppression of the fan noise at higher orders of harmonics (higher than the 10th) will become rather difficult, because a small number, five, of blades 32 will result in complex calculations in obtaining the blade pitch angles.
Fourth Embodiment, FIGS. 7 and 8
In FIG. 7 is shown a fourth embodiment of the present invention which is applied to a rotor or wheel of a gas turbine or a steam turbine. A turbine wheel 40 comprises a hub 43 and 29 radial blades 42 arranged at irregular or unequal pitch angles circumferentially of the hub 43. The tips of the blades 42 are retained by a retaining ring 44. The tips of the blades 42 are attached to the ring 44 at points p 1 through p 29 on a circle 46 whose center is the axis 45 of the turbine wheel 40. The pitch angles of the blades 42 are also defined by the central angles θ 1 ' through θ 29 ' subtended at the center 45 of the circle 46 by the arcs p 1 p 2 through p 29 p 1 , respectively. In the fourth embodiment, θ' 1 =21.2°, θ 2 '=7.2°, θ' 3 =13.6°, θ' 4 =11.0°, θ' 5 =18.9°, θ' 6 =4.6°, θ' 7 =6.5°, θ' 8 =10.9°, θ' 9 =14.4°, θ' 10 =4.0°, θ 11 '=23.3°, θ 12 '=23.7°, θ 13 '=5.5°, θ 14 '=17.5°, θ 15 '=7.0°, θ 16 '=7.8°, θ 17 '=4.5°, θ 18 '=35.8°, θ 19 '=4.0°, θ 20 '=8.8°, θ 21 '=11.5°, θ 22 '=5.8°, θ 23 '=18.5°, θ 24 '=11.7°, θ 25 '=4.5°, θ 26 '=11.2°, θ 27 '=20.1°, θ 28 '=11.4° and θ 29 '=15.1°. The reference point for the blade angular positions θ 1 through θ 29 is also the point p 1 as with the first, second and third embodiments. Therefore, θ 1 =0°, θ 2 =θ' 1 , θ 3 =θ' 1 +θ 2 ' and so on. The order-of-harmonic characteristic of the blade pitch of the turbine wheel 40 is shown in FIG. 8.
The blade angular position θ 1 through θ 29 of the turbine wheel 40 may also satisfy Eq. (2) and Eq (3), because when Z=29, e=80.5 dB from Eq. (4). The turbine wheel 40 is mechanically well balanced. Furthermore, unpleasant periodic noise, whose period depends upon a number of blades 42, may be considerably suppressed. In addition, the sound pressure level of the turbine wheel noise may be also reduced.
The fourth embodiment may ensure the suppression of the noise from the first to the 58th order of harmonics. The suppression of noise higher than 58th may be attained rather easily because of a large number of blades 42.
So far the present invention has been described only in conjunction with the wheels with Z=5, 12, 13 and 29, but it will be understood that the present invention may be equally applied to a fan wheel or a turbine wheel with more than five blades. | A wheel or rotor with a plurality of blades arranged at irregular or unequal pitch angles circumferentially of a disk, a hub or the like, wherein the characteristic level e k representative of the order-of-harmonic characteristic of blade pitch is defined by
e.sub.k =10 log.sub.e d.sub.k +100
where ##EQU1## Z=a number of blades k=1,2, . . . and n; n≧Z
θ j =the angular position of the tip or root of each blade defined in terms of a central angle subtended at the center of a circle, which is the axis of said wheel or rotor, by an arc extended from a reference point on said circle to said tip or root of each blade on said circle, j=1,2, . . . and Z; and
the characteristic level e k satisfies the following conditions ##EQU2## where e=-13.14 log 10 Z+99.70
k=2,3, . . . n. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of swimming pool copings; and, more particularly, to a swimming pool coping member constructed of solid surfacing material.
2. Description of the Prior Art
A swimming pool coping is a structure which functions to cap the upper edge of the side walls of a swimming pool and to provide a transitional element between the side walls and the horizontal deck surrounding the pool. Usually, the coping extends around the periphery of the pool and includes a convex-shaped rounded portion which faces toward the interior of the pool and serves as a hand hold for swimmers to rest or to climb into or out of the pool. In swimming pools which have a vinyl liner, the coping often includes a portion which extends downwardly somewhat along the side walls of the pool and which has a slot or other structure for receiving and retaining a bead disposed at the top edge of the liner. Such copings may also be designed to include structures to receive and retain lights or other accessories for use in the pool.
Swimming pool copings are constructed of various materials including cement, brick, stone, aluminum and plastic; however, such materials are not always fully satisfactory. In particular, because of its location around the edge of the swimming pool, the coping is subjected to substantial use and is frequently abused. For example, it is constantly being stepped on and jumped on and is often hit by toys, pool servicing equipment and other items carried in or around the pool. Copings constructed of cement, stone or brick can chip or crack as a result of such use not only creating an unsightly appearance, but also providing locations where water can collect. Such standing water can provide a breeding ground for algae, mildew and the like; and, if allowed to freeze, can cause significant damage to the coping and to the overall structure of the pool. Cement is also rather porous and can retain water even when not damaged.
Although coping materials such as stone, brick and cement are often repairable as by patching, replacing bricks, etc. the repairs are often costly and not fully satisfactory because the patches or new materials are usually much brighter in color than the original materials and thus detract from the appearance of the coping. Copings formed of plastic are usually also not fully satisfactory as they are difficult to repair and are often rather flimsy and become wavy or otherwise misshapen over time. Aluminum copings can bend and also become deformed over a period of time.
SUMMARY OF THE INVENTION
The present invention provides a swimming pool coping member that is highly durable, easy to install and maintain and very attractive in appearance. A swimming pool coping member according to the present invention is adapted to be installed around at least a portion of a periphery of a swimming pool and comprises a solid molded body composed of solid surfacing material having one or more additives or fillers incorporated therein for enhancing properties of the body as a coping member, the solid surfacing material comprising a material which is cast or extruded, colored throughout, and about 98 percent or more de-aired, and which comprises a resin selected from the group consisting of polyester, acrylic or a combination thereof, and an inert filler which functions as an extender for the resin.
Solid surfacing material possesses numerous properties which make it especially suitable as a swimming pool coping including being non-porous and thus highly water-resistant, and extremely durable. Solid surfacing material also has chemical resistance, stain resistance and a high degree of repairability all important properties of a good swimming pool coping.
A swimming pool coping member according to the present invention can be provided in any desired color; and because the coloring in a solid surfacing material extends throughout the body of the member rather than being painted on or otherwise applied to the surface of the member, the color will tend to retain its appearance and not fade or otherwise deteriorate over time as rapidly as with many existing coping materials.
According to presently preferred embodiments of the invention, various additives or filler materials are incorporated into the solid surfacing material formulation to enhance the properties of the member as a swimming pool coping. For example, as indicated above, coloring agents can be added to the formulation to provide the coping in a desired color. Also, if desired, a suitable inhibitor can be added to increase the flexibility or resiliency of the solid surfacing material somewhat so that it is better able to resist chipping or cracking due to impacts or the like. An appropriate algaecide can also be added to the formulation to combat the growth of algae around the pool which is often a significant problem with some swimming pools, although solid surfacing material, due to its non-porous nature, has a high resistance to the growth of algae, mildew and the like in any event. A UV stabilizer may also be added to further increase the resistance of the member to deterioration by sunlight. These various additives and fillers can all be added to the solid surfacing material formulation prior to the molding of the member.
An important aspect of the present invention is that the swimming pool coping member is capable of being easily repaired. In particular, chips or cracks In the coping can often be readily repaired by simply filling them in utilizing a conventional solid surfacing material repair kit, and then sanding the repaired surface as appropriate. This is an important advantage over many conventional coping materials which often cannot be easily repaired. More significantly damaged members can be repaired by cutting away the damaged member and replacing it with a new section. Such new section can be blended into the existing section, if desired, to provide a smooth, substantially seamless appearance.
Another important aspect of the coping member of the present invention is that it provides tremendous flexibility in design. For example, as indicated above, it can be provided in essentially any desired color. Thus, it can be colored to match or contrast with the color of the pool deck, pool furniture or other articles used in or around the pool. The coping member can also easily be provided with inlaid portions in any desired pattern or design in the same or a different color. For example, a design can be laser engraved or sandblasted on the surface of the member and then filled in by solid surfacing material of a different color or by another material and finished to provide a very attractive appearance. The surface of the member can also be textured in any desired manner, if desired, for attractiveness and/or to provide a non-slip surface.
The coping member of the present invention can be manufactured in convenient sizes of, for example, two feet lengths; and applied side-by-side around the periphery of the pool by laying the members in a layer of cement or the like. The separate members or coping sections could be grouted or, if desired, the members could be blended together to provide the appearance of a continuous one-piece coping. The coping members will often be lighter in weight than conventional coping materials and thus will be less costly to ship and easier to handle.
Further advantages and specific features of the present invention will become apparent hereinafter in conjunction with the following detailed description of presently preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a portion of a swimming pool incorporating a swimming pool coping according to a presently preferred embodiment of the present invention;
FIG. 2 is a cross-sectional view of the upper edge of the swimming pool of FIG. 1;
and FIG. 3 illustrates a portion of a swimming pool incorporating a swimming pool coping according to alternative embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a swimming pool of generally conventional type with which the swimming pool coping member of the present invention may be utilized. The swimming pool is generally designated by reference number 10 and includes a bottom 12 and side walls 14 . As is well-known, the pool may include a shallow portion 16 and a deeper portion 17 joined together by an inclined portion 18 of the bottom 12 .
Reference number 20 indicates the deck or walkway surrounding the pool, and swimming pool coping 22 extends around the pool, and connects the side walls 14 of the pool to the deck 20 as is known to those skilled in the art.
Specifically, as shown more clearly in FIG. 2, the side walls 14 of the pool are typically constructed of cement or the like and extend upwardly from the bottom of the pool. The walls are typically about 4 to 6 inches thick but increase to a thickness of 10-12 inches adjacent the top end thereof in order to accommodate the width of the coping and to provide structural strength and integrity to this rather sensitive area of the pool.
Often, a row or two of tiles 24 are attached to the side walls of the pool around the top thereof to a depth of, for example, 6 to 12 inches (see FIG. 2 ). The tiles provide an attractive accent to the pool's edge while serving as an easily cleanable surface.
The coping 22 surrounds the pool, and, in effect, serves to cap the side walls of the pool and to connect the side walls to the deck 20 around the pool. In the embodiment shown in FIG. 2, the coping is about 12 inches wide and includes a convex-shaped inwardly facing rounded portion 30 and a generally flat, tapered portion 32 which extends from the rounded portion to the deck around the pool. The rounded portion 30 functions to provide a handhold for swimmers to rest or to climb into or out of the pool, while the flat portion 32 tapers down from the rounded portion to the deck to provide a smooth transition with the deck. The coping 22 is about two inches thick adjacent the rounded portion 30 and tapers down to a thickness of about ¾ inch adjacent the deck 20 .
It should be understood that the particular coping design shown in FIG. 2 is intended to be exemplary only as the coping can be designed to have any appropriate configuration. It should also be understood that in pools with vinyl liners, the coping often extends downwardly somewhat along the side walls of the pool and includes a groove or similar structure to receive and retain the upper beaded end of the liner. The coping of the present invention is also intended to cover such embodiments as well.
The swimming pool coping of the present invention is constructed of solid surfacing material which provides the coping with numerous advantageous features typically not found in conventional coping materials. A solid surfacing material is generally recognized in the industry as comprising a product which is cast or extruded, colored throughout and 98 percent or more de-aired, utilizing a matrix consisting of a resin (for example, polyester, acrylic or a combination thereof) and inert fillers, most commonly aluminum trihydrate (A TH) which functions as an extender for the resin and which is a well-known fire retardant and thus renders the coping as a whole highly fire-resistant.
Solid surfacing materials are available in the marketplace from various sources, for example, under the trademark CENTURA available from Centura Solid Surfacing, Inc. of Westfield, Ind., and under the trademark CORIAN available from DuPont; and, accordingly, specifics of its manufacture need not be recited herein in any substantial detail. CENTURA solid surfacing material is a rigid, de-aired material composed primarily of a thermoset polyester component, while CORIAN solid surfacing material is believed to be a substantially rigid, non-foamed, non-laminated or coated material composed primarily of thermoformed acrylic components.
In general, a solid surfacing material may be manufactured by mixing an unsaturated polyester resin with aluminum trihydrate of the appropriate particle size. Appropriate additives and colorants may also be added to the mix, depending on the particular application in which the finished article is to be used. The mix is then homogenized in a vacuum mixer forcing air from the product so that the product is 98 percent or more de-aired. After a short mixing cycle, the mix is then transferred into a mold and then molded; and when ready, the molded article is demolded and finished as appropriate or desired.
The molded article may be fabricated by injection molding, extrusion molding, bulk molding compounding (BMC) and other molding techniques to achieve article that is highly chemical resistant, stain resistant and repairable and that can 1 ˜tooled into many shapes and designs using common woodworking tools. Because it is a fully densified product, it has a non-porous surface which is a highly desirable property for a swimming pool coping.
A swimming pool coping member according to the present invention may be molded in an open-faced cavity. The mold may be formed of silicone rubber or other deformable material to facilitate removal of the member from the mold after completion of the molding process. When molding by other techniques such as, for example, bulk molding compounding, a rigid mold such as a stainless steel mold is generally preferred.
After removal from the mold, the member can be sanded and/or otherwise finished as desired for a particular application. For example, the surface thereof can be brushed or otherwise treated to provide it with a desired texture or appearance and/or to provide it with a non-slip surface.
In accordance with preferred embodiments of the present invention, various additives and fillers are added to the solid surfacing material formulation to enhance its properties and characteristics as a swimming pool coping. For example, as indicated above, colorants are preferably added to provide the coping in a desired color. Preferably also, a UV inhibitor is added to the mix to resist fading of the color. In addition, although solid surfacing material, by virtue of its being a highly non-porous material, tends to inhibit the growth of algae, mildew or the like, which is a particularly important property in the environment of a swimming pool; if desired, a suitable algaecide or the like can be added to the formulation to further inhibit such growth.
In addition, if desired, a lightweight filler such as a quantity of hollow microspheres or the like can be added to the mix to reduce the weight of the member so as to make it less-expensive to transport and easier to handle. Also, a small amount of an additive such as an inhibitor may be added to the formulation to increase the resiliency of the member somewhat so as to enable it to better withstand impacts without chipping or cracking. Such an inhibitor may comprise a quinone inhibitor such as toluhydroquinone which is believed to function by preventing a 100 percent cure of the solid surfacing material and thus renders the member somewhat more flexible or resilient.
An important aspect of the coping of the present invention is that it is readily repairable. In particular, with the present invention, small cracks or chips in a coping member can easily be repaired at the pool by utilizing a commercially available solid surfacing material repair kit such as is marketed by Centura Solid Surfacing, Inc., and then sanding the repaired surface as appropriate. Use of the repair kit provides a generally seamless repair and greatly facilitates maintenance of the coping.
As shown in FIG. 1, the swimming pool coping of the present invention is conveniently formed of a plurality of separate coping members or sections 34 of, for example, two feet in length, with each section comprising a single, molded member of solid surfacing material. The sections can conveniently be applied on a base of cement as shown at 42 in FIG. 2; or, if preferred, secured in place by means of a suitable adhesive. Adjacent sections can be connected by a suitable grouting material 44 as shown in FIG. 1; or, alternatively, the sections can be blended together by solid surfacing material to provide the appearance of a single coping member (as schematically illustrated by the continuous sections 40 in FIG. 1 ).
A swimming pool coping constructed of solid surfacing material provides a great deal of flexibility in designing the coping. As indicated above, for example, it can be manufactured in any desired color and thus can be colored to match or contrast with the color of the deck, of furniture used around the pool or of any other desired article in or around the pool. Different coping sections of the coping could also be made in different colors, if desired. It is also possible and relatively easy to form appropriate designs or patterns on the coping. For example, a pattern can be laser engraved or sandblasted onto the surface of each section and the pattern thus formed filled in with solid surfacing material of a contrasting color or of tile or other material to provide a coping having a very attractive appearance. As shown, for example, in FIG. 3, the same design 46 may be formed in each section or member 34 to provide a repetitive pattern around the pool, or different designs 47 , 48 in the same or different colors could be provided in different members arranged in different ways. An essentially endless number of design possibilities can be envisioned.
While what has been described constitutes presently preferred embodiments of the invention, it should be recognized that the invention could take numerous other forms. Accordingly, it should be understood that the invention should be limited only insofar as is required by the scope of the following claims. | A swimming pool coping install able around the periphery of a swimming pool. The coping is formed of a plurality of coping members each of which is a solid molded body composed of solid surfacing material having one or more additives or fillers incorporated therein to enhance properties of the body as a swimming pool coping The coping is highly durable, easy to install and maintain and provides a very attractive appearance. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/759,302, filed Apr. 13, 2010, which is hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to surface prepping and, in particular, to prepping surfaces using abrasive particles (or blasting particles) entrained into a continuous or pulsed waterjet or airjet.
BACKGROUND
[0003] Prior to applying a coating to a surface, it is generally necessary to prep the surface to ensure that the surface has the appropriate surface roughness. Prepping the surface is often accomplished using grit blasting (e.g. using cast iron shot or aluminum oxide) or by using an abrasive-entrained fluid. A variety of abrasives are known in the art, for example, sand, garnet, Zeolite (which are aluminosilicates of sodium, potassium, calcium or magnesium), alumina, and grit (i.e. crushed ferrous or synthetic abrasives). These abrasive particles (herein referred to as “blasting particles”) can be used to prep a surface, be it metallic or non-metallic, to a desired surface roughness.
[0004] Once the prepping of the surface is complete, coating material, which may be in the form of coating particles, is applied to the prepped surface. Coating particles can be applied using various techniques such as, for example, thermal spray coating (including combustion powder flame spray and High Velocity Oxy-Fuel), plasma spray, cold spray, etc.
[0005] Once the surface prepping is complete, the surface may need to be cleaned or washed, either by rinsing or other such method to remove the blasting particles that may remain on the surface to be coated. In many cases, this is accepted as satisfactory. However, there are many instances where the particles regularly used for blasting become embedded in the atomic matrix of the surface to be coated. This is highly undesirable as even a single foreign particle may adversely affect the micro-structural properties of the surface to be coated. For instance, when the surface is coated with the high-velocity oxy-fuel (HVOF) process using metallic particles such as tungsten, the coating particles will not adhere to the surface at the location where the foreign particle is embedded. Thus, the point where the particle resides may become a point of weakness of the surface, and in service may lead to unpredictable behaviour, including catastrophic failure.
[0006] An improvement on this conventional prepping process would thus be highly desirable.
SUMMARY
[0007] The present invention provides a novel method and apparatus that eliminates the problems associated with the use of foreign blasting particles for surface prepping. The problems associated with the prior art are overcome by using the coating particle as a blasting particle (or abrasive particle) for prepping the surface to be coated. In other words, the surface prepping of a component is done using the same coating particle that is to be used to coat the surface of the component.
[0008] This invention will not only eliminate the problem of embedding a foreign particle into the surface to be coated, but also offers many other advantages leading to considerable savings in cost and in the abatement of pollution.
[0009] For example, in the high velocity oxy-fuel (HVOF) coating technique, tungsten carbide is one of the particles used for coating a surface by entraining and propelling the particle in the flame jet produced by combustion of volatile liquids such as kerosene in oxygen/air. The same system can be used for prepping the surface using tungsten carbide particles without combustion. In other words, in the first stage, the surface to be coated is prepped with tungsten carbide particles. In the second stage, the same particles are used in the flame for coating the surface. Since the same particles are used for both prepping and coating, the problem of disposing of the conventional grit-blast particles is totally eliminated. Furthermore, as cleaning the blasted surface is not required, additional savings in time and cost will be achieved. Moreover, the novel process produces less pollution as disposal of waste products is eliminated altogether since blasting particles that do not adhere may be recycled and reused for coating. The same methodology applies in other coating techniques such as the plasma coating technique. In other words, the coating particles used as blasting particles for prepping the surface can be entrained in high-speed fluid jets. A further improvement in the prepping technique can be achieved by entraining the coating particles in continuous or pulsed waterjet or in continuous or pulsed airjet (using, for example, the techniques disclosed in U.S. Pat. Application Publication US 2010/0015892 A1, published Jan. 21, 2010 and entitled “Method And Apparatus For Prepping Surfaces With A High-Frequency Forced Pulsed Waterjet”). Therefore, the coating particle is used as the blasting particle for prepping the surface prior to coating.
[0010] This innovative method thus preps a surface using an abrasive-entrained waterjet or airjet wherein the same or similar particle that is to be used for subsequently coating the surface is also used as a blasting particle for first prepping the surface. In other words, the coating particle is entrained into the waterjet or airjet (or other fluid stream) for prepping the surface. The waterjet or airjet can be either a continuous stream or a pulsed (modulated) stream. Accordingly, prepping operations can be done with the same coating particle used to coat the surface, i.e. with only one type of coating particle that is used for both prepping and coating, as opposed to using one type of abrasive particle for prepping and then a different type of particle for coating.
[0011] In accordance with a main aspect of the present invention, an apparatus for prepping a surface comprises a nozzle for directing a fluid stream at the surface to be prepped and a container for containing a supply of coating particles. The apparatus further includes a particle delivery subsystem connected to the nozzle for delivering the coating particles into the nozzle to thereby entrain the coating particles into the fluid stream. The apparatus also includes a pressure source for pressurizing the fluid stream to generate a pressurized fluid stream that is directed through the nozzle at the surface to be prepped to thereby prep the surface with the coating particles.
[0012] In accordance with another main aspect of the present invention, a system for prepping a surface using a coating particle and then coating the surface with the same type of coating particle includes a nozzle for blasting the surface with the coating particle to thereby prep the surface to a desired surface roughness for subsequent coating, wherein the same nozzle is also used for coating the surface with the same type of coating particle used to prep the surface. The system includes a container for containing a supply of the coating particles. The system includes a particle delivery subsystem connected to the nozzle via one or more particle inlets for delivering the coating particles from the container through the one or more particle inlets into the nozzle to thereby entrain the coating particles into the fluid stream. The system includes a pump for pressurizing the fluid stream to generate a pressurized fluid stream that is directed through the nozzle at the surface to be prepped to thereby prep the surface with the coating particles. The system further includes a control system for controlling the apparatus for switching being a first mode of operation in which coating particles are entrained into the pressurized fluid stream to thereby prep the surface and a second mode of operation in which substantially the same coating particles are propelled at the surface to thereby coat the surface.
[0013] In accordance with yet another main aspect of the present invention, a prepping and coating system comprises a nozzle for directing a fluid stream carrying coating particles at a surface to be sequentially prepped and then coated using the same type of coating particles, the nozzle comprising particle inlets for injecting the coating particles into the nozzle, the nozzle including a mixing chamber for mixing the coating particles with the fluid stream. The system also includes a container for containing the coating particles and a particle delivery subsystem connecting the container to the nozzle for delivering the coating particles into the nozzle to thereby entrain the coating particles into the fluid stream, the particle delivery subsystem including a metering system for metering the coating particles. The system also includes a pump for pressurizing the fluid stream to generate a pressurized fluid stream that is directed through the nozzle at the surface to be prepped to thereby prep the surface with the coating particles, and a control system for controlling the particle delivery subsystem to control delivery of the coating particles into the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further features and advantages of the present technology will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
[0015] FIG. 1 is an illustration of a pulsed waterjet system that entrains a coating particle as a blasting particle for surface prepping;
[0016] FIG. 2 is an enlarged illustration of the nozzle head used in the system depicted in FIG. 1 ;
[0017] FIG. 3 is an illustration of another embodiment of a nozzle head that can be used in a pulsed waterjet;
[0018] FIG. 4 is a schematic depiction of an airjet system for entraining coating particles into a continuous or pulsed airjet;
[0019] FIG. 5 is an illustration of a Laval (converging-diverging) nozzle for a continuous or pulsed airjet; and
[0020] FIG. 6 is a schematic depiction of an HVOF apparatus operable in a first mode (without combustion) to prep the surface using the coating particle as a blasting particle and in a second mode (with combustion) to subsequently coat the surface using the same coating particle.
[0021] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION
[0022] In general, the present invention is directed to a novel method and apparatus for prepping a surface of a component using a coating particle as the blasting particle (i.e. as the abrasive particle). In other words, the coating particle itself is used as the blasting particle (abrasive particle) that preps the surface prior to coating the surface with the same type of particle. The coating particle can be carried by a pulsed waterjet, a continuous waterjet, a pulsed airjet, a continuous airjet or any other pulsed or continuous (low-temperature or high-temperature) fluid stream. A pulsed waterjet is believed by Applicant to be the best mode of implementing this technology because of the maximal erosive effects (mass removal rates) associated with pulsed waterjet technology. Because the coating particle is ingeniously used as the blasting particle, the problems associated with grit-blasting or prepping using a different particle than what is used to coat the surface are eliminated. This prepping technique not only saves time and cost as there is no need to clean or rinse the grit-blasted surface, but also reduces waste and cleanup time (because a different abrasive is not used). Furthermore, this novel technique enhances the bonding or adhesion of the coating particle to the prepped surface since no foreign abrasive particles are embedded into the surface to be coated.
[0023] In the various embodiments of this invention, which will be described below in greater detail, a pulsed or continuous waterjet or airjet apparatus is used to entrain a coating particle such as, for example, a thermal spray coating particle or other coating particle, that is to be applied to the surface after the surface prepping is complete. By entraining the coating particle into the fluid stream, the coating particle is thus used as an abrasive or blasting particle. In other words, the coating particle and the abrasive particle are the same, or at least highly similar in composition, hardness, granularity, etc. This represents a very substantial innovation over the prior art. Conventionally, a surface is prepped using an abrasive to produce a desired surface finish or surface roughness. This surface finish or surface roughness is typically determined ahead of time by the type of coating particle that is to be applied. Thus, empirically it is known that optimal particle retention (coating-surface adhesion) is achieved by prepping the surface to within a certain range of surface roughness. In the prior art, the surface is then typically prepped to within that desired range of surface roughness using a standard abrasive particle (blasting particle) such as, for example, grit, garnet or Zeolite. The problem identified by Applicant is that remnants of blasting particles (abrasive particles) can remain embedded in the atomic matrix of the surface being prepped. These embedded particles can reduce the adhesion of the subsequent coating and/or create local points of weakness leading to unpredictable failure. Applicant has thus realized that this problem can be obviated by using the coating particle as the blasting particle (abrasive particle). This ensures that no foreign particles remain after the prepping. If coating particles are embedded into the atomic matrix of the surface being prepped, then this has no deleterious effect since this particle would have been applied to the surface eventually in the subsequent coating operation. Particles that do not adhere to the surface can be reused or recycled for the subsequent coating stage.
[0024] In one embodiment, a coating particle of a slightly different granularity (mesh size) or slightly different composition can be used to prep the surface prior to application of the coating. For example, the coating particles used for prepping may be larger in mesh size than the coating particles used for coating. Using a larger particle to prep the surface is advantageous as these larger particles more closely resemble the larger grit-blast particles that are traditionally used for surface prepping. Despite their larger mesh size, these larger coating particles tend to become smaller in mesh size as they impinge on the surface and are themselves blasted by subsequently impinging particles. A large proportion of the particles that fail to adhere to the surface tend to be these particles of a reduced size. These reduced-size (non-adhered) particles, however, are ideal for coating operations because coating particles used for actually coating should have a smaller mesh size than those used for blasting. Accordingly, these reduced-size particles can be recycled and reused, with optional filtering, for subsequent coating of the prepped surface.
[0025] Main embodiments of the present invention will now be described below, by way of example, with reference to the attached drawings.
[0026] Coating-Particle-Entrained Pulsed Waterjet
[0027] In one embodiment of this invention, a pulsed waterjet apparatus is used to entrain coating particles into the modulated water stream to prep the surface. Pulsed waterjet technology has been developed by Applicant and has been disclosed in U.S. Pat. No. 7,594,614 (Vijay et al.) entitled ULTRASONIC WATERJET APPARATUS and in U.S. Pat. No. 5,154,347 entitled ULTRASONICALLY GENERATED CAVITATING OR INTERRUPTED JET, which are hereby incorporated by reference.
[0028] FIG. 1 depicts a pulsed waterjet system 100 having a pulsed jet eductor nozzle and a coating particle supply unit. In the particular example depicted in this figure, the pulsed waterjet system 100 has an air inlet 102 for receiving substantially clean, dry and oil-free air into the air lines of the system, a control valve 104 (e.g. a 4-way, 5-port control valve or any other suitable valve), an isolator valve 106 , an air control line 108 , a purge air line 110 , a particle metering system 112 , a particle feed line 114 and a pulsed jet head (i.e. ultrasonic nozzle assembly) 120 for modulating the waterjet to create a pulsed waterjet. The ultrasonic nozzle 120 can be modified from any of the nozzles depicted in U.S. Pat. No. 7,594,614, for example. In addition, as shown schematically in FIG. 1 , the system includes a water pump 130 (or other pressure source) for supplying pressurized water into the water inlet 127 of the nozzle 120 . The system also includes an ultrasonic generator 140 for generating an ultrasonic drive signal for driving the transducer (i.e. causing the transducer and microtip to oscillate at the desired frequency).
[0029] FIG. 2 illustrates the nozzle 120 shown in FIG. 1 in greater detail. As shown in this figure, the nozzle 120 has a piezoelectric or magnetostrictive transducer connected to a microtip 121 for modulating the waterjet. Pressurized water is brought into the nozzle 120 at a water inlet 127 . Coating particles are injected or suctioned into the nozzle via an angled particle inlet (suction port) 123 . In the particular configuration depicted in FIG. 2 , the particle inlet (suction port) is part of a cylindrical body 122 threaded onto the nozzle as an outer annular component surrounding the portion of the nozzle housing the microtip. A mixing chamber 124 is provided downstream of the angled particle inlet (suction port) to mix the particle with the modulated/pulsed waterjet to create a pulsed slurry (i.e., the slurry consists of water and the particles). The nozzle 120 also includes an outlet tube 126 extending from the mixing chamber 124 through which the modulated waterjet passes.
[0030] FIG. 3 presents another embodiment of a nozzle assembly 120 that can be used with the pulsed waterjet system 100 in order to entrain coating particles for performing surface preparation operations. The nozzle is designed for directing a particle-entrained modulated fluid stream at the surface to be prepped. As shown in this figure, the nozzle 120 has a microtip 121 , a pair of angled inlets (suction ports) 123 , a mixing chamber 124 , and a water inlet 127 , as previously described. In addition, the nozzle of FIG. 3 has an adapter (bell-shaped diverging section) 125 connected to the downstream end of the mixing chamber. A tube 126 is then connected to the downstream end of the adapter 125 . Changing the sizes of the adapter ( 125 ) and the tube ( 126 ) will enable to prep small and large parts, that is small or large areas of substrates. The system therefore comprises a particle delivery subsystem connected to the nozzle for delivering a supply of coating particles into the nozzle. In the example setup presented in FIG. 1 , this particle delivery subsystem includes the air inlet, the isolator valve, the air control line, the purge line, the hopper and supply lines of the metering system, and the feed line. The system also includes a control system for controlling the apparatus (i.e. system 100 ). The control system in this particular example includes the flow valve of the particle metering system. This control system can be manually operated or automated (i.e. microprocessor controlled).
[0031] Coating-Particle-Entrained Continuous Waterjet
[0032] In another embodiment of this invention, the waterjet can be a continuous waterjet instead of a pulsed waterjet. The continuous waterjet can be pressurized to very high pressures to achieve the desired surface preparation effect. The continuous waterjet can be generated using a standard waterjet apparatus having no ultrasonic transducer or by deactivating the ultrasonic transducer in an ultrasonic waterjet apparatus.
[0033] Coating-Particle-Entrained Pulsed Airjet
[0034] In another embodiment of this invention, a pulsed airjet apparatus can be used to entrain a stream of coating particles as abrasives (blasting particles) into the fluid stream for prepping a surface.
[0035] FIG. 4 is a schematic depiction of an airjet apparatus 200 for entraining coating particles for generating a coating-particle-entrained continuous or pulsed airjet or any other low-temperature or high-temperature fluidjet. As depicted in this figure, the airjet system 200 includes a compressor inlet 201 and a compressor 202 for pressurizing the apparatus. The apparatus 200 includes a reservoir (storage cylinder) 203 for storing a volume of pressurized air and also includes a pressure regulator 204 , an air valve 205 , and an air pressure gage 206 . The airjet apparatus 200 further includes a coating particle hopper 207 for holding a supply of coating particles 208 . A metering valve 209 is provided for metering the outflow of particles into a feed line leading to a pulsed or continuous nozzle 210 . This pulsed or continuous nozzle generates, respectively, a pulsed or continuous particle-entrained airjet 211 for prepping a surface of a component or work piece 212 . This work piece may be held in a jig, clamp, holding device or work piece support 213 as shown by way of example in this figure. The airjet system may optionally include a rotating device 214 to rotate the work piece.
[0036] As will be appreciated by those of ordinary skill in the art, the compressor 202 and reservoir 203 together constitute an example of a pressure source, as the term is used in the present specification, for pressurizing the fluid stream. As will also be appreciated by those of ordinary skill in the art, the coating particle hopper 207 , the feed line leading from the hopper 207 to the nozzle 210 , and metering valve together constitute an example of a particle delivery subsystem, as the term is used in the present specification, for delivering a supply of coating particles into the nozzle. A computer control system may be provided to control the operation of the airjet apparatus.
[0037] FIG. 5 is a schematic depiction of a Laval (converging-diverging) nozzle for generating a coating-particle-entrained continuous or pulsed airjet. In a preferred embodiment of the airjet system 200 , the nozzle 210 is a Laval nozzle having a converging section followed by a diverging section as shown in the figure. The Laval nozzle, which was developed in 1897 by Swedish inventor Gustaf de Laval, is already known in the art, but can be used advantageously in the airjet apparatus. See, e.g. “Machining of Solid Materials by High Speed Airjet” by R. Kobayashi, Y. Fukunishi & T. Ishikawa published in Jet Cutting Technology (BHR Group; D Saunders, Editor) as Proceedings of the 10 th International Symposium (Amsterdam, The Netherlands, 31 Oct.-2 Nov. 1990). As will be appreciated by those of ordinary skill in the art of fluid mechanics, the Laval nozzle may have either conical or bell-shaped sections.
[0038] As further depicted in FIG. 5 , for a pulsed airjet, the airjet system 200 includes an oscillating magnetostrictive or piezoelectric transducer with a microtip 220 (akin the one described and illustrated above in relation to the force pulsed waterjet apparatus) for generating a pulsed airjet. This ultrasonic transducer with microtip 220 is located inside the nozzle 210 as shown in FIG. 5 , with the microtip extending into the converging section of the Laval nozzle. A particle inlet 223 is preferably disposed downstream of the microtip 220 .
[0039] Flow characteristics can be modulated by varying key parameters such as the diameter of the air inlet, diameter of the throat (d N ), diameter of the exit orifice (d e ), and the angles θ 1 and θ 2 . These are all important parameters to generate a highly coherent and high-speed coating-particle-entrained continuous or pulsed airjet. Since the density of air is quite low, the operating pressures will be of the order of 1,000 psi (6.9 MPa).
[0040] Coating-Particle-Entrained Continuous Airjet
[0041] In another embodiment of this invention, the airjet can be a continuous airjet instead of a pulsed airjet. The continuous airjet can be pressurized to achieve the desired surface preparation effect. The continuous airjet can be generated using a standard airjet apparatus having no ultrasonic transducer or by deactivating the ultrasonic transducer in an ultrasonic airjet apparatus.
[0042] To summarize, in each of the four embodiments described above, the same coating particles that are to be subsequently used for coating the surface are also used as the blasting particles (abrasive particles) for first prepping the surface. The coating particles are entrained into the fluid stream, be it water or air, continuous or pulsed. The apparatus is designed so that the coating particles are preferably drawn into the nozzle downstream of the microtip connected to the forward end of the ultrasonic transducer to thereby avoid wearing the microtip.
[0043] FIG. 6 is a schematic depiction of a high-velocity oxy-fuel (HVOF) apparatus 300 used for an HVOF spray process. This apparatus directs coating particles at the surface in a first mode of operation with no combustion (a surface-prepping mode) and then delivers the same coating particles, albeit melted or liquefied by the heat, in a second mode of operation with combustion (coating mode).
[0044] As depicted in FIG. 6 , this HVOF apparatus 300 has oxygen and fuel inlets 301 , 302 that deliver oxygen and fuel, respectively, to a combustion chamber 304 for stoichiometric combustion of the fuel in the presence of the oxygen. This combustion generates the heat necessary to melt or liquefy the coating particles. The apparatus 300 includes a coating particle powder and carrier gas inlet 306 for injecting coating particles (typically in powder form). These coating particles are carried by a carrier gas (fluid stream). The coating particles and carrier gas are injected into the nozzle 308 via a powder feed port 310 . The nozzle 308 also includes combustion gas feed ports 312 . The coating particle powder and gas feed ports enable the powder to mix with the hot gases, so as to melt or liquefy the coating particle powder. The nozzle includes an outlet passage 314 through which the fluid-entrained coating particles are expelled. The HVOF apparatus 300 includes cooling passages 316 for heat transfer. These cooling passages 316 may be placed around the combustion chamber 304 and/or around the outlet passage 314 .
[0045] For example, in the HVOF apparatus illustrated in FIG. 6 , one can inject coating particles (larger size as the surface finish requires grit-blasted specs) in the powder inlet and carrier gas stage without combustion to prep the surface to be coated. This is similar to the airjet described above. After the surface is prepped, one can then inject coating particles into the fluid stream and initiate combustion to generate a high-temperature flame jet to coat the component. Therefore, the same system can be used for prepping and coating. This eliminates the conventional grit-blasting system, disposal of the grit-blasted waste (metal particles and grit particles), energy consumption and also the cleaning process that is usually necessary to clean the surface prior to coating, which contributes to the abatement of pollution. Furthermore, the coating particles used as blasting particles will gradually become smaller in size due to impact on the surface and eventually can be used for coating the surface. Therefore, an additional advantage is, in effect, there is no loss of particles. As these particles are quite expensive, a considerable cost savings can be achieved. While an HVOF apparatus is described, the principle of using the same coating particle for both prepping and coating may be used not only in HVOF, but also in any other thermal spray process, or by analogy with plasma spray or cold spray. For plasma spray, coating particles are used to prep the surface without ionization and then the same coating particles are used to coat the prepped surface with ionization. Similarly, for cold spray, the surface is prepped using coating particles at one velocity and then the same coating particles are used to coat the prepped surface at another velocity.
[0046] The embodiments of the invention described above are intended to be exemplary only. As will be appreciated by those of ordinary skill in the art, to whom this specification is addressed, many obvious variations, modifications, and refinements can be made to the embodiments presented herein without departing from the spirit and scope of the invention. The scope of the exclusive right sought by the applicant is therefore intended to be limited solely by the appended claims. | Prepping a surface entails entraining a coating particle into a fluid stream, directing the fluid stream containing the coating particle at the surface to be prepped to thereby prep the surface using the coating particle. The prepped surface can then be coated using the same or substantially similar coating particle. This technique can be used with a continuous airjet, a forced pulsed airjet, a continuous waterjet or a forced pulsed waterjet as the carrier stream. This invention solves the problem of foreign blasting particles becoming embedded in the atomic matrix of the surface to be prepped, which can result in unpredictable behaviour of the surface properties and even catastrophic failure. | 2 |
BACKGROUND INFORMATION
[0001] 1. Field of the Invention
[0002] The invention relates to the field of motorcycles and other two-wheeled motor vehicles having handlebars. More particularly, the invention relates to hand-actuated devices on the handlebars of a motorcycle. More particularly yet, the invention relates to a restraining device for a clutch lever.
[0003] 2. Description of the Prior Art
[0004] Motorcycle drivers manually pull a clutch lever in toward the handlebars to disengage a clutch. The clutch lever is biased to a clutch-engaging position, and a significant amount of force must be exerted to pull the lever in far enough to disengage the clutch. During normal driving, when shifting gears, engaging and disengaging the clutch lever is an operation that is executed rather quickly and, thus, does not generally cause undue strain on the motorcycle operator's hand. The situation is different, however, when the operator has to stop travel for a brief period, during which time the operator may opt to hold the clutch lever in, rather than finding neutral and releasing the clutch lever. The reason for this is that it can be difficult to find neutral, particularly on older motorcycles. Neutral is located between first and second gear and, unlike shifting in a car, in which the operator can shift into neutral from any gear, on a motorcycle the operator has to shift sequentially down through the gears to get to neutral. For example, if a motorcycle is moving along a highway in fifth gear, and the operator must stop at a toll booth, he or she shifts down through all the gears, until reaching neutral. The physical spacing between gears is very close, and particularly close between the first and second gears. Typically, the distance between first and second gears is only one-half the physical distance between any other two gears. So, when shifting down, it is very easy to inadvertently click or step through neutral. Newer model motorcycles are equipped with a light that indicates when the transmission is in neutral. With older model motorcycles, the operator typically tries to test whether it is in neutral, while the bike is still rolling. Frequently, motorcycle operators simply hold the clutch lever in the clutch-disengaging position when stopping for a brief period of time, for example, when stopping at a toll booth or in traffic, or when participating in a parade. Since the clutch is wetted with oil, this “riding the clutch” is not detrimental to the clutch, as it is with automobiles.
[0005] Holding the clutch lever for more than just a few seconds causes fatigue and sore muscles in the hand, because of the force that must be constantly exerted against the clutch lever spring. Furthermore, the clutch lever is typically mounted on the left handlebar and, thus, it is the left hand that is used to operate the clutch lever. Highway toll booths are, however, on the left side of the lane, which means that the operator has to use the right hand to hand the toll to the collector or throw it into the coin basket, if he can't find neutral quickly enough.
[0006] What is needed, therefore, is a device that will hold the clutch lever in its clutch-disengaged position, so as to free up the left hand of the operator. What is further needed is such a device that is easily and quickly engaged and released. What is yet further needed is such a device that is inexpensive, and easy to retrofit on existing motorcycles.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention is a clutch lever assist that is mounted on the handlebar of a motorcycle. The clutch lever assist has a handlebar mount and a catch or finger that is pivotally assembled on a pivot pin on the handlebar mount. The catch is spring-biased to spring to a release position. The intended use of the clutch lever assist is to hold a clutch lever on a motorcycle handlebar in its clutch-disengaged position, in order to relieve the operator from the strain of having to hold the clutch lever for any extended period of time. To use the clutch lever assist, the motorcycle operator pulls the clutch lever toward the handlebar to a position that disengages the clutch. With the lever in this position, the operator uses the thumb to lift the non-operative end of the catch or uses a finger to push the operative end down toward the clutch lever. The operative end of the catch has a hook shape, which captures the lever, holding it in the clutch-disengaged position. Moving the clutch lever slightly toward the handlebar beyond the hook portion of the catch quickly and automatically releases the catch, which springs automatically back to its release position and leaves the clutch lever under the hand control of the operator.
[0008] Optionally, a safety lock may be incorporated into the clutch lever assist. The safety lock has a pin that the operator rotates between a lock position and an unlock position. When in the lock position, the safety pin prevents the non-operative end of the catch from dropping back to its spring-biased position. This effectively prevents the catch from being inadvertently released from the clutch lever.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawings are not drawn to scale.
[0010] FIG. 1 is a side view of a first embodiment of the clutch lever assist according to the invention, showing the clutch lever assist mounted on a handlebar and holding the clutch lever in the clutch-disengaged position.
[0011] FIG. 2 is a side view of the clutch lever assist in its release position, showing the mounting bolts and biasing spring.
[0012] FIG. 3 is a perspective view of the clutch lever assist, showing the pivot bolt and the opening for the setscrew.
[0013] FIG. 4 is a perspective view of a second embodiment of the clutch lever assist according to the invention, which is counterweighted.
[0014] FIG. 5 illustrates a safety lock for locking the catch into a clutch-lever disengaged position.
[0015] FIG. 6 is a cross-sectional view, illustrating the safety lock in its lock position.
[0016] FIG. 7 is a cross-sectional view, illustrating the safety lock in its unlock position.
[0017] FIG. 8 is a side elevational view of the safety pin.
[0018] FIG. 9 is a cross-sectional view of the safety pin, showing that it is a round bar with a recess.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art.
[0020] FIG. 1 shows a preferred embodiment of a clutch lever assist 100 according to the invention, comprising a handlebar mount 140 and a pivotally mounted catch 120 . The catch 120 is pivotable between a capture position, in which it engages and holds an actuation lever in a force position, and a release position, in which it is unengaged. The clutch lever assist 100 is shown mounted on a handlebar HB and in the capture position, holding an actuation lever, such as a clutch lever CL, in a clutch-disengaged position. The handlebar HB and clutch lever CL are shown in cross-sectional view only.
[0021] FIGS. 2 and 3 show details of the components of the preferred embodiment of the clutch lever assist 100 . The handlebar mount 140 has an upper mount 142 and a lower mount 144 , which together form a handlebar-recess 141 . Threaded fasteners 146 are used to fasten the two parts together around the handlebar HB. A set screw 148 is used to position and tighten the mount 140 to the handlebar HB, to as to hold the clutch lever assist 100 in a desired position. The catch 120 is pivotally mounted on a pivot pin or bolt 130 in the mount 140 . A biasing spring 132 fastened at one end to the mount 140 and at the other end to the catch 120 biases the catch 120 to the release position, as shown in FIG. 2 . There are many conventional methods of attaching the biasing spring 132 to the catch 120 and the mount 140 . A simple and effective method is to capture each end of the spring 132 in recesses 229 provided on each component.
[0022] The catch 120 has a first end 124 that is shaped to form a hook and recess 126 , so as to capture and restrain the clutch lever CL when in the capture position shown in FIG. 1 . The catch 120 is constructed to facilitate capturing the catch lever CL with a minimum of effort. In the embodiment shown, the second end 122 is constructed to allow the operator to either push against the end 122 with a thumb, or place a finger or thumb under it and lift. Alternatively, the operator may use a finger to push the first end 124 down toward the capture position. Pushing the catch 120 against the spring bias lowers the first end 124 of the catch 120 . If the clutch lever CL has been pulled in toward the handlebar HB, moving the catch 120 to the capture position will allow the first end 124 to capture the clutch lever CL. Once captured, the operator may relax his or her grip on the catch 120 . The two forces being exerted on the catch 120 , i.e., the force exerted by the clutch lever CL against the first end 124 and the upward force exerted by the biasing spring 132 , cooperate to securely hold the clutch lever CL captured in the clutch lever assist 100 .
[0023] Releasing the clutch lever CL from the clutch lever assist 100 merely entails pulling the clutch lever CL in toward the handlebar HB. As can be envisioned from the illustration in FIG. 1 , a slight displacement of the clutch lever CL in toward the handlebar HB removes the clutch lever from the constraints of the first end 124 of the catch 120 . The catch 120 is then free to swing back to its release position and the clutch lever CL free to swing out to its clutch-engaging position.
[0024] An additional recess 229 A facing in an opposite direction may also be provided on the upper mount 142 , in order to accommodate the various models and configurations of handlebar setups and grips on motorcycles. For example, some motorcyclists prefer larger, cushioned grips. In order to accommodate the larger dimensions of the cushioned grip, the mounting for the clutch lever is readjusted, to move the clutch lever CL out farther from the handlebar, to accommodate the larger handgrip. The standard setup for the clutch lever assist 100 may not work effectively in this case, because the catch 120 may not be not long enough to capture the clutch lever CL. Either the additional recess 229 A or the pivot pin 130 for mounting the catch 120 is offset from the center of the mount 140 . In the embodiment shown, the pivot pin 130 is offset from the center. Reversing the mount 140 and using this additional recess 229 A for mounting the catch 120 moves the catch 120 out farther past the handlebar HB, so that the catch 120 is now able to capture the readjusted clutch lever CL.
[0025] FIGS. 5-9 illustrate a safety lock 150 that may be incorporated into the clutch lever assist 100 as an optional device, to secure the catch 120 in its capture position. It may be desirable for certain maneuvers that require that the clutch be held disengaged to be able to lock the catch 120 in the capture position. For example, the operator may want to get on or off the bike, while the engine is running and use the handlebar HB as leverage. Or a police officer may want to get off the motorcycle in a hurry, yet leave it running, with the clutch lever secured in the clutch-disengaged position. In such cases, it would be hazardous, if the operator were to inadvertently bump or squeeze the clutch lever CL while the catch 120 was in the capture position, because this would cause the catch 120 to automatically release and move toward the release position. The safety lock 150 allows the operator to secure the catch 120 in the clutch-lever engaging position, so that it cannot be inadvertently released, even if the clutch lever CL is squeezed.
[0026] The safety lock 150 comprises a safety pin 154 that is inserted into a safety-pin aperture 157 on the upper mount 142 . The safety pin 154 is essentially a round pin with a recess 156 formed in a central section of the pin. An actuating tab 155 is provided on one end of the safety pin 154 for manipulating the safety lock 150 . See FIGS. 8 and 9 . The cross-sectional views in FIGS. 6 and 7 illustrate how the safety pin 154 is rotated to shift the safety lock 150 between a lock position and an unlock position, respectively. Arrow A indicates the direction of rotation. When in the lock position, the safety pin 154 is rotated such, that a wide dimension D of the safety pin (shown in FIG. 9 ) is in a vertical position. This prevents the second end 122 of the catch 120 from moving downward and holds the first end 124 in the capture position. Thus, if the motorcycle operator were to bump the clutch lever CL, so that the catch 120 would normally automatically release, the safety lock 150 will prevent the release. When in the unlock position, the safety pin 154 is rotated until a narrow dimension N is in a vertical position. This allows the non-operative or second end 122 of the catch 120 to move farther down and release the operative or first end 124 from the clutch lever CL.
[0027] FIG. 4 illustrates a second embodiment of a clutch lever assist 200 according to the invention. The clutch lever assist 200 is a single component body 210 having a handlebar recess 241 for mounting on a handlebar, a first end 224 , and a second end 222 . The handlebar recess 241 fits over the handlebar HB with sufficient play to allow the clutch lever assist 200 to rotate easily about the handlebar. In the embodiment shown, the single component body 210 is placed on the handlebar HB by first removing the hand grip from the handlebar and slipping the single component body 210 onto the handlebar HB into the desired location. The first end 224 is similar in shape and function to the first end 124 of the first embodiment, in that it is shaped like a hook 224 to form a clutch lever recess 226 for capturing the clutch lever CL. The second end 222 has a counterweight 228 that serves to bias the first end 224 to a release position. In the embodiment shown, the counterweight 228 is a threaded bolt inserted through a bore that is provided on the second end 222 and secured on the opposite face of the body with a nut. It is understood, however, that there are numerous ways to mount a counterweight on the clutch lever assist 200 . To engage the clutch lever CL, the operator merely moves the first end 224 down toward the clutch lever CL. Once the clutch lever CL is captured in the clutch lever recess 226 , the spring force of the clutch lever and the counterweight 228 cooperate to securely hold the catch lever CL within the hook 224 . As with the first embodiment, pulling the clutch lever CL slightly toward the handlebar HB releases the clutch lever CL from the clutch lever assist 200 , which automatically rotates to is release position, in which the first end 224 is raised above the plane of the clutch lever CL.
[0028] It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the clutch lever assist may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims. | Clutch lever assist for capturing and holding a motorcycle clutch lever in its clutch-disengaged position. The assist mounts on the handlebar and has a catch that pivots between a capture position and a release position. The motorcycle operator pulls the clutch lever in toward the clutch-disengaged position and uses a finger or thumb to urge the catch to its capture position. Once the clutch lever is captured, the operator may relax his grip. The catch will hold the clutch in its clutch-disengaged position. Pulling the clutch lever in toward the handlebar slightly, beyond the capture portion of the catch, releases the catch, which is spring-biased and automatically springs back to its release position. The clutch lever is now under operator control. A safety lock is provided optionally on the clutch lever assist, to lock the catch into the clutch-lever engaging position. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to methods of raising funds, in particular, to obtaining financial contributions from interested individuals for the creation of content, such as artistic works, in exchange for some degree of artistic control over the content.
BACKGROUND
[0002] Many writers, musicians, and other authors and artists have difficulty in completing content due to a lack of financial resources to cover the costs associated therewith. For example, musical content requires the individual or group of musicians to record, market, and distribute copies of the recording before any financial return can be generated. These steps are associated with significant costs that present an insurmountable barrier to many authors and artists.
[0003] Methods and systems are known that provide artists a way of raising funds for the creation of content, such as U.S. Pat. No. 7,885,887 B2, “Methods and Apparatuses for Financing and Marketing a Creative Work”. However, known methods and systems involve the offering of entitlements such as copies of the creative work, upon completion thereof, or collectible items related to the artist. Such methods amount to a pre-sale of the creative work or collectible items. Often, the amount paid for such an entitlement is less than the amount that would otherwise be paid for the completed creative work. Both the creative work, once completed, and the collectible items could be sold independently of such a method or system and could otherwise generate revenue for the artist.
[0004] Accordingly, there is a need for a method and/or system that allows an author to raise the necessary funds to complete content that does not rely on the sale of discounted items that could otherwise be sold by the author to generate revenue.
SUMMARY OF THE INVENTION
[0005] To meet the need identified above, the present invention provides methods for raising funds for the creation of content, such as artistic works, by which interested individuals can provide financial contributions to a project in exchange for some degree of artistic control over one or more parts of the content.
[0006] One aspect of the present invention is a computerized method for raising funds for the creation of artistic works, comprising the steps of receiving an artistic work from an author, displaying at least a portion of the artistic work on a website accessible to visitors, offering creative control to the artistic work or parts thereof to the visitors to the website in exchange for payment, and receiving payment from one or more of the visitors in exchange for conveyance of the creative control.
[0007] In another embodiment, the method further comprises the steps of displaying options to exercise the creative control to the one or more of the visitors, receiving an election from the one or more of the visitors to exercise the creative control, storing the election in a database, and transmitting the election to the author.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] In order that the invention may be more clearly understood, preferred embodiments thereof will be described in detail, by way of example, with reference to the accompanying drawings, in which:
[0009] FIG. 1 is a flow chart, showing the steps for an author to create a project.
[0010] FIG. 2 is a flow chart, showing the steps for a visitor to create an account and log in to the website.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] As used in the following description, the term “content” refers to one or more artistic works, such as, for example, musical recordings, performances, lectures, choreography, films, television programs, literature, newspaper or magazine articles, pamphlets, scripts, paintings, drawings, maps, charts, plans, photographs, engravings, sculptures, works of artistic craftsmanship, or architectural works. The term “content” may also refer to a compilation of artistic works.
[0012] As used in the following description, the term “creative control” refers to the determination or selection of parts of content. Every part of the content is subject to creative control, usually by the author, including, in the case of a film for example: plot elements, the script, the title of the film, cast members for one or more roles, the director, filming location, alternate scenes/endings, character names, costume or set elements, or any other part of the film.
[0013] As used in the following description, the term “project” refers to content, such as an artistic work, including an unfinished artistic work, and a fundraising effort therefor, which an author has started through a fundraising website, as further described below.
[0014] In one embodiment of the method according to the present invention, as shown in FIG. 1 , an author logs on to a fundraising website 1 , using a computer executing an internet browsing application. The author may also upload content at any stage of completion to a project server, over a network such as the internet, for posting on the fundraising website in a “projects” area. A hosting server, which may be the same as the project server, is part of, or coupled to, an internet service provider to provide access to the fundraising website over the Internet. The computer and server used for the purposes of the present invention are known to a person of skill in the art and generally include a processor, memory, and input/output capability coupled to a system bus, capable of storing data and instructions, which may be executed by the processor to perform the methods described herein.
[0015] Although the present invention is described in relation to internet-based network connections, other types of network connections may be used, for example, private networks. Further, although the present invention is described in relation to a computer, which may include various computing devices, such as desktop computers or laptop computers, other types of electronic devices may be used, such as tablets, smartphones, or other electronic device capable of storing, transmitting, and receiving information, data, and instructions, which may be executed by a processor.
[0016] The author creates a project 2 by outlining the type of content to which the project relates and what content will be open to creative control by visitors to the website. The content may also be a collection that includes more than one artistic work, such as, a musical recording album, which consists of a plurality of individual songs. The author specifies certain parts of the content, which will be open to creative control by visitors to the fundraising website. The author may also provide additional information concerning the content, such as a working title, alternate endings, or a description of the portions of the content which are incomplete. The additional information will be displayed along with the content in the “projects” area of the fundraising website. Access to the content by visitors to the fundraising website may be limited by the author, for example, in the case of a novel, access may be limited to a synopsis or one or more excerpts from the novel, and in the case of a musical recording, access may be limited to a brief clip of the entire recording.
[0017] The author then defines certain limits on the creative control 3 over the content, which will be available to visitors to the website. For example, the author may limit the available creative control by describing and defining only certain parts of the content which will be open to creative control by visitors. The author may define and describe more than one set of limits, or levels of creative control. The author finally sets a price 4 , or donation amount, for each set or level. Alternatively, this may be done through a set of online tools that provide the author with various pre-determined options, one or more of which may be selected each with a corresponding price, which may be pre-determined or set by the author.
[0018] Visitors to the “projects” area of the fundraising website will receive an offer to purchase some degree of control over one or more pieces of the content (i.e. One or more works). Preferably, a visitor will receive an offer relating to a particular piece of content while viewing that content in the “projects” area of the fundraising website.
[0019] The offer may, therefore, include different levels of creative control, corresponding to different prices. The different levels of creative control may also relate to different parts of the content. For example, the author may define two levels of creative control in which a small payment entitles a visitor to select the title of the content from a list of potential titles, a larger payment entitles a visitor to additionally select the ending of the content from a list of potential endings. Creative control over any part of the content may be offered by the author, such as, in the case of a film for example, selection of: cast members for one or more roles, the director, filming location, alternate scenes/endings, character names, costume or set elements, or any other part of the film.
[0020] The scope of the creative control that is open to the visitor is determined as described above, but the type of creative control privileges may also vary. Preferably, the type of creative control that visitors will be offered over a particular piece of content will be voting privileges concerning a list of pre-determined options for one or more parts of the content. The author may elect to offer other types of control, such as complete and exclusive control over certain parts of the content. Exclusive control may, for example, involve exclusive selection by one individual of certain parts of the content from a list of pre-determined options. The author may also offer a first type of control over a first part of the content and a second type of control over a second part of the content. For example, in the case of a film, the author may choose to offer exclusive selection privileges over certain costume or set elements, while offering voting privileges concerning the selection of cast members and alternate endings.
[0021] In order to exercise any purchased creative control privileges, a visitor will access the fundraising website 5 , for example, as shown in FIG. 2 , using a web browser on a personal computer with an internet connection. The visitor will then create an account 6 and choose a password. The account is validated against a current email address 7 and the visitor is granted access and logs in 8 with the account and password.
[0022] The visitor will then have access to any purchased creative control privileges and may elect to exercise one or more of these privileges. The user may be given access to any purchased creative control privileges directly in the “projects” area of the fundraising website, or through a separate “privileges” area, which displays all of the creative control privileges the visitor has purchased.
[0023] When a visitor exercises a purchased creative control privilege, such as a voting privilege, the election is transmitted to a creative control server to be recorded and processed. The creative control server may be the same server as the hosting and/or the project server, or a separate server. In the example of voting privileges, the vote cast by the visitor is transmitted to the creative control server where it is recorded in a database, corresponding to the part of the content to which the vote relates. The votes are counted and the results posted on the “projects” area of the fundraising website, either as a real-time running tally of the votes cast or as a final total once certain conditions are met to end the voting. These conditions, which are referred to herein as “closing conditions”, may be the expiry of a certain window of time or the accumulation of a pre-determined target amount of money. Once the closing conditions are met, creative control over that part of the content is closed and no further offers are made to visitors, in respect of that part of the content.
[0024] Visitors who have purchased creative control privileges, but have not exercised them before the closing conditions are met, may be given an opportunity to exercise their privileges before the corresponding part of the content is finalized. For example, visitors who have purchased voting privileges concerning the title of a film with closing conditions dependent on the accumulation of a target amount of money may be given ten days, after the target is reached, to cast their vote before the votes are counted and the title is chosen. Alternatively, visitors may be permitted to exercise all purchased creative control privileges for a given piece of content until a certain date, regardless of whether any other closing conditions have been met.
[0025] The methods of the present invention, described above, are carried out by one or more computers and servers, executing instructions from computer-readable media. The description of the methods above enables one of skill in the art to develop computer software in a variety of programming languages, containing instructions that can be executed on a variety of hardware platforms by a variety of operating systems to carry out the methods of the present invention. | A method of raising funds for the creation of artistic works by obtaining financial contributions from interested individuals. An author uploads an artistic work to a website and offers visitors to the website creative control to the artistic work or parts thereof in exchange for payment. | 6 |
This is a division of Ser. No. 363,596, filed May 24, 1973, now U.S. Pat. No. 3,881,550.
BACKGROUND OF THE INVENTION
The present invention relates in general to the art of oil recovery and, more in particular, to recovery of hydrocarbons from heavy crudes or bitumens by stimulation.
There are large petroleum deposits in the form of very viscous crudes or bitumens. These deposits may be residuals from naturally developed fields or deposits which have never been produced. An example of very viscous tar deposits is in the Peace river and Athabasca regions of Canada. These tars have a gravity of from 6° to 20° API, a clean oil viscosity of to 20,000 cps, and an emulsion viscosity of to more than 100,000 cps. The asphaltene content of these deposits is up to 30% and sulfur up to 6%. Because these tars are so viscous, they cannot be recovered by natural techniques and must be stimulated.
Stimulation of petroleum deposits by steam flooding is a known and tested technique. In this type of stimulation, high pressure and temperature steam is injected into injection wells for recovery of petroleum from production wells. During steam stimulation, steam heats a deposit in a steam zone. Values are distilled there and are forced by steam pressure away from the injection wells towards the production wells. Some of the distilled hydrocarbons will condense in the steam zone because of heat loss from the zone to surrounding strata. Some of the distilled hydrocarbons will reach a front between a hot condensate zone and the steam zone and condense there. The driving force of the steam pressure, however, continuously advances the condensed hydrocarbons towards the production wells. The hot condensate zone itself fronts on a cold water zone more remote from the steam zone. Finally, there is an oil zone bordering the cold water zone which is the formation unaffected by stimulation. In typical steam flooding, the cold water zone is water flooded and oil is removed by this known technique to the water flooding saturation level. The advancement of the hot condensate zone itself stimulates recovery by lowering viscosity of the oil and by thermal expansion of the oil. Within the steam zone, recovery is promoted, in addition to distillation, by the temperature produced agencies of viscosity reduction and formation swelling. Hydrocarbons are usually recovered at the production wells in primarily liquid form. The considerable driving force of the steam flooding technique is ultimately lost when breakthrough occurs at a production well. This is an event where the steam front advances to the production well and steam pressure is largely dissipated in the well. The well becomes a short circuit. After steam stimulation, the usual practice is to produce without stimulation until further stimulation is necessitated or production terminated.
Obviously, in the steam flooding technique distillation plays only a modest role at best for very heavy crudes such as the Peace River bitumens because they do not contain any considerable light values. Consequently, the action of steam in stimulating recovery from deposits such as the Peace River bitumens must be by viscosity reduction from heating, thermal expansion of the formation, and the driving force of the steam. Even then, recovery can be modest because of channeling resulting from the permeability of the deposits, fractures, and gravity override between the steam and liquid in the hot and cold zones.
Importantly also, is the effect of even modest distillation on bitumens or tars. With these crudes, the boiling away of lights will cause the residual crude to become so viscous that no further recovery would be possible, even with the viscosity lowering effect of high temperature from the steam.
Consequently, it has been thought that steam drive recovery is limited to deposits with an API gravity of 20° or greater.
Cold solvent stimulation of oil deposits has improved recovery. Solvents can repair organic and inorganic damage, clean deposited asphaltenes and waxes out from around well bores, and lower the viscosity of the hydrocarbons in the deposit by cutting and demulsification. Demulsification reduces the viscosity of the hydrocarbon deposit because emulsions of water-in-oil and oil-in-water have higher viscosities than oil alone. Solvent stimulation also removes asphaltenes from the deposits. Removal of asphaltenes is especially good with aromatics.
The removal of crude oil from the deposit, however, can create a situation where the solubility of remaining asphaltenes is reduced. Remaining asphaltenes precipitate on surfaces of the deposit and block the passage of crude. Accordingly, to prevent asphaltene precipitation and blockage of the deposit, surfactants have been added to maintain the wetability of deposit surfaces, which prevents blockage.
One of the major drawbacks of solvent stimulation is the high cost of solvent. Quite obviously, if the cost of solvent required to produce effective stimulation of a deposit becomes too great, then solvent stimulation cannot be practiced. Heretofore it has been the practice to produce at least most of the solvents away from the stimulation site. This is so especially with aromatic solvents which are very useful in dissolving asphaltenes.
SUMMARY OF THE INVENTION
The present invention provides solvent stimulation of hydrocarbon deposits having extremely high viscosities, such as found in the Peace River region of Canada.
In brief, the present invention contemplates the use of a hot solvent generated from product on site to recover hydrocarbon product values from heavy crudes or bitumens. The hot solvent is injected into the deposit and functions to reduce deposit viscosity by demulsifying viscous emulsions of crude-in-water and water-in-crude, solvent cutting of crude and raising the temperature of the crude. The solvent also solubilizes production restricting precipitated waxes and asphaltenes. The solvent can be used to remove scale deposited from produced water, sand deposited around well bores, and drilling and completion damage. The solvent is introduced at a temperature of from about 200° to about 650°F. and is preferably depentanized naphtha of up to about an 800°F. end point. This naphtha has substantial quantities of aromatics, the aromatics being useful in the dissolving of asphaltenes and waxes. The solvent may be manufactured from recovered bitumen by topping or by a combination of topping with visbreaking or reforming. Surfactants may be added to the solvent to prevent deposition of asphaltenes on deposit formations by keeping surfaces in the formation water wetable. Suitable surfactants are butylamines or mixed alkyl phenols.
The presently preferred embodiment of the present invention contemplates the use of both solvent and steam extraction of hydrocarbon values from tars or bitumens typified by the Peace River deposits. This is done by either injecting steam and solvent vapors and liquids continuously into the formation or by cyclic injection of steam and hot solvent. With steam, thermal reduction in crude viscosity results and reservoir fluids expand. There will be some, though small, distillation of hydrocarbons by the steam from heat and partial pressure reduction. With the decrease in viscosity, gravity drainage is promoted. The steam pressure, say, 1500 p.s.i.a. at injection, will strongly drive crude towards production wells.
The steam-solvent process retains the production resulting from thermal stimulation of deposits by the steam while eliminating or minimizing production restrictions occasioned by viscous emulsions, precipitated waxes and asphaltenes, scale and sand deposition, and drilling and completion damage.
When steam and solvent are used together, the difficult problem of solvent-crude mixing is not present because the steam is a low viscosity fluid which will rapidly fill all available voids in the reservoir and carry solvent with it. The solvent can then function more completely throughout the formation.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates schematically a prior art steam driving technique for the recovery of hydrocarbons as it would apply in tar deposits of the Peace River type;
FIG. 2 illustrates schematically steam and solvent recovery of hydrocarbon values in a deposit of the Peace River type; and
FIG. 3 is a flow diagram of a plant for the implementation of the process of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates schematically a typical steam drive system which has been implemented before the present invention. Its description is helpful in understanding the principles behind the process of the invention.
In the Figure, injection wells 10 are provided through overburden and to and through tar sands 12. The overburden is, say, 2000 feet and the production interval is, say, 100 feet. In the Peace River deposit, the production interval varies from about 50 to about 1000 feet. Production wells 14 are also provided through the overburden and the production interval.
Steam of a quality of 70 to 80% and at a pressure up to about 2500 p.s.i.a. and at about 668°F. is injected into the injection wells. A pressure seal in the overburden prevents backflow of this steam from either the injection wells or production wells.
The gravity of the tars or bitumen in the Peace River deposits is from about 6° to about 20° API. The clean oil viscosity is up to about 20.000 cps. In the emulsion, however, the viscosity increases to more than 100.000 cps. The asphaltic content of the Peace River type of tars is up to about 30%. The sulfur content is also high, being up to about 6%. The tar sands may be bottomed by a water zone indicated at 16.
Steam injected through the injection wells will progress from that well radially toward the production wells. During the steam drive, a steam zone 18 will continuously expand radially away from the steam injection well. Within the steam zone hydrocarbon vapors will be generated, but immobile hydrocarbons will remain. Owing to temperature rise, the deposit will also expand and there will be a reduction in viscosity. A steam front 20 separates a hot condensate zone 22 from the steam zone. Along this front and into the hot condensate zone condensation of hydrocarbon vapors will occur as steam condenses. Within the hot condensate zone, the temperature varies from steam temperature to reservoir temperature. The hot condensate zone, as is the case in the steam zone, progressively increases with time. Reservoir heating in the hot condensate zone is augmented by the latent heat of the steam and condensing hydrocarbon vapors. A cold water zone 24 is ahead of the hot condensate zone and receives some heat from fluids passing into it from the hot condensate zone. The balance of the reservoir indicated at 26 and is at the original reservoir temperature. As will be seen, with a steam drive system alone, no production occurs from this zone because the hydrocarbons are too immobile to be recovered at the original reservoir temperature.
A production mechanism in the steam drive system illustrated in FIG. 1 is the steam distillation of hydrocarbons in the steam zone. The transfer of the heat energy from the steam to the reservoir deposits will thermally expand these deposits which also results in the production of hydrocarbons. The heating of the deposit also reduces viscosity which makes the oil values there more mobile and results in production. The heated hydrocarbons will drain by gravity and be recovered at the production wells which may have bottom hole pumps. A driving force form the pressure differential between the injection wells and the production wells will continuously force hydrocarbons towards the latter for recovery.
Prior techniques of steam stimulation also include the so-called "huff" and "puff" system. In this system, steam is injected for a considerable period of time into a well without attendant oil production. The injection steam is eventually stopped and oil production commences with the stimulation by steam improving the production rate from the well for a time. Ultimately, the well may be restimulated or not, depending on economics. This technique is an alternative to that known as the "steam drive" discussed above.
FIG. 1 also shows a condition which is known as steam breakthrough during steam drive. Steam breakthrough occurs when steam appears at the production wells. The result of this phenomenon is the loss of the driving pressure of the steam and a marked diminution in the efficiency of the system. A second phenomenon is also illustrated in FIG. 1, and that is steam channeling. It will be noted that the steam zone breaks through at a production well along a very short vertical distance. This channeling is the result of gravity override, permeable strata and horizontal fractures in the reservoir. Gravity override results from the different densities of the steam and the condensate, with the latter tending by gravity toward lower depths. When steam breakthrough occurs, economy precludes continued steam injection, for excessive heat is lost to surrounding strata and is vented up the casing of the production well, this notwithstanding continued gravity drainage due to the rise in temperature of hydrocarbon values in the reservoir. Other problems encountered in the steam drive system is the production of extremely viscous emulsions of oil-in-water and water-in-oil. As previously mentioned, emulsion viscosities can exceed 100,000 cps.
The problem of hydrocarbon immobility from excess viscosity is compounded by removal of distillates from the formation by the steam distillation in the steam zone.
The precipitation of waxes and asphaltenes can effectively block recovery of hydrocarbon values and this precipitation can occur when lighter hydrocarbons are taken from the reservoir. Scale deposition from produced water can also reduce recovery. Steaming can also result in sand deposition around well bores with the result that recoveries are adversely affected. Finally, drilling and completion damage adversely affect recovery.
These problems are reduced by the implementation of hot solvent stimulation of the present invention. The solvent is produced at the production site. With reference to FIG. 2, injection wells 28 are formed in the same manner as the injection wells of FIG. 1. Similarly, production wells 30 are formed in the same manner. The overburden and production zones and water zones are the same. In FIG. 2, production of hydrocarbons is effected by the injection of a mixture of steam and solvent vapors and liquid. The solvent is in two phases, that is, both liquid and vapor. Since the steam has a quality of less than 100% a water phase is also present.
An important aspect of the present invention is the manufacture of solvent on site. THe solvent should have a relatively low viscosity and a high aeromatic content. An ideal solvent is depentanized naphtha having a maximum end point of up to about 800°F.
The production mechanism of the FIG. 2 system includes an increase in mobility of the hydrocarbons through viscosity reduction. Viscosity reduction, as in the steam drive system, results from temperature rise. But in addition to the purely thermal effects of viscosity reduction, an important reduction in viscosity will also be the result of solvent cutting or mixing with the hydrocarbons of the reservoir and the demulsification of the extremely viscous emulsions within the reservoir. This production mechanism also results in thermal expansion of the reservoir fluids due to their heating by both the steam and the solvent. The thermal expansion results in the release of hydrocarbons for recovery. The steam-solvent system also recovers values by gravity drainage. The reduction in viscosity and increased mobility allows hydrocarbon values to drain for recovery. Again there is a driving force because of the pressure differential between the injection fluid at the injection well and the produced fluid at the production well. The steam may act as a solvent carrier to expose a considerable amount of the deposit to the solvent.
Steam channeling will again occur due to the factors previously set forth, gravity override, permeability of strata, and horizontal fractures. However, the steam channeling may be effectively used to disperse solvent throughout the reservoir. This solvent also prevents precipitation of waxes and asphaltenes at the well bores and washes out scale, sand, and drilling and completion damage.
In FIG. 2, a hot vapor zone 32 is illustrated and it has a front with a cold water and solvent zone 34. The unaffected portion of the reservoir is shown at 36 and it has the originally constituted hydrocarbons at original reservoir temperature. It should be noted that the use of both steam and hot solvent as recovery vehicles results in greater recovery. The hot solvent conditions the deposit for greater thermally induced recovery over that which would result from steam alone.
Initially, with deposits such as in Peace River, about 10 to about 25% of the gross product is recycled as hot solvent, after the solvent is made by the processing steps set out below. As the process continues, the gross product increases because the injected solvent is being recovered with the crude. It is possible that product solvent will be left over.
The making of the solvent on site is inexpensive and, with surplus product solvent sold with crude, the quality of the crude increases. Solvent purchased for stimulation, say, cyclohexane, is normally much more expensive than the products produced.
In the simultaneous injection of steam and solvent, in general for each barrel of crude produced and removed from the reservoir, there then may be used about 3 170 barrels of water converted to steam and about 1/3 barrel of solvent produced. This ratio, however, is no wise limiting and any ratio of steam to solvent may be employed depending on conditions and process economics.
The solvent produced, such as depentanized naphtha having a high aromatic content, should be heavy enough to dissolve the heavier hydrocarbons of the bitumen, but not so heavy as to create mobility problems and remain in the formation. The preferred solvent has a boiling point range of from about 200° to about 800°F. An acceptable range is from about 200° to about 500°F. The solvent must have a high aromatic content to dissolve asphaltenes. Small quantities of non-ionic surfactants may be used with the solvent. These surfactants are useful in maintaining the wetability of the deposit being processed so that precipitated asphaltenes will not prevent recovery.
As was previously mentioned, hot aromatic solvent will break highly viscous emulsions in the reservoir. They also increase crude temperature and, as such, further decrease the viscosity of the crude.
The present invention also contemplates the cyclic introduction of steam and solvent. The steam stimulates in the manner previously described, i.e., primarily by viscosity reduction and formation swelling, resultant gravity drainage, and pressure drive. In the steam zone, distillation of some values will occur. These values form a solvent slug.
After steam termination the solvent is injected hot at from about 200° to about 650°F, to stimulate the steam flooded formation by demulsification, solvent cutting and temperature effects. The solvent cleans up the deposit by removing asphaltenes, waxes, sand and the like. With demulsification, solvent cutting and removal of asphaltenes, the residual crude is conditioned for processing again by steam.
As indicated steam is injected first and steam injection continues until breakthrough at a production well. Steam injection is then terminated and hot solvent injection commenced. Solvent injection is continued until the solvent-to-crude ratio is about 1 to 3. Steam is then injected again until breakthrough. Steam is always injected last to recover solvent from the deposit. As an alternative the "huff" and "puff" technique may be employed with solvent and steam, or steam followed by hot solvent injected into the well for a period of time during which production is periodically terminated while stimulation occurs.
The present invention also contemplates recovery of hydrocarbons from highly viscous deposits of tars or bitumens by hot solvent stimulation alone. The solvent is injected into the injection wells at a temperature of from about 200° to about 650°F. The solvent is produced from recovered crude at the site and is preferably depentanized naphtha having an end point of less than about 800°F. The solvent has a high aromatic content for the solubilizing of asphaltenes. The production mechanism is demulsification of oil-in-water and water-in-oil emulsions, solvent cutting of heavy components of the crude, some formation heating, and removal of physical and chemical impediments to production in the formation.
With reference to FIG. 3, a system to implement the present invention is illustrated. Again there are a series of production wells that may be bottom-hole pumped. These wells are indicated by the single line 40. A series of steam injection wells are provided at 42. A production zone or interval 43 is the same as in the previous Figures, that is, it varies from 50 feet to 1000 feet and is very heavy in tars of the type found in the Peace River deposits. The production zone has a fairly thick overburden 44 on it and is bottomed by a water zone 46.
Product from the recovery leaves the deposit as a steam 48 and consists of heavy crude or tar, water and sand. Stream 48 is introduced at the well head into a separator 50. The separation is of the gaseous constituents of the product and steam from liquid product, sand and water. The gaseous constituents are H 2 S, CO 2 , steam and light hydrocarbons and they leave the separator as a stream 52. The well head separator is provided to measure the production streams and also provides a preliminary breakup of emulsions, which may be by known chemical treatment with the addition of heat, if required. Stream 52 is compressed in a compressor 54 and a compressed stream 56 is introduced into a stream 58 from an emulsion breaker 60 to form a new stream 62. The stream from the emulsion breaker contains crude oil. The united streams enter a topping unit 64, such as a distillation column.
A crude oil, sand and water stream 68 leaves well head separator 50, passes through a pump 72 before entering line 74. The stream 74 is combined with a recycled stream of light hydrocarbons 76 as a diluent to constitute a stream 78 which passes through heater 80 into a desander 82. A sand and sludge stream 84 from the desander goes to disposal. A stream 86 from a desander enters emulsion breaker 60 where the emulsion is further broken. The requisite input for emulsion breaking is indicated by the flow arrow 88. Emulsion breaking may consist of chemical dehydration, chemical-electrical treaters, flotation and skimming, filtration, centrifuging, or a combination of these methods.
Crude oil stream 58 from the emulsion breaker combines with gas stream 56 to form a stream 62 which is introduced into topping unit 64, which may include a visbreaking and/or reforming unit to increase the aromaticity of the solvent produced.
A water and oil stream 89 leaves the emulsion breaker and is introduced into a flotation cell 90. In the flotation cell, air is introduced at 92 and the water and oil are separated. In addition, any residual sand is separated from the water and oil, as indiciated by an egress sand stream 94. The separated water stream 96 from flotation cell 90 enters a water treater 98. There, the water may be treated in such a manner as to be suitable for disposal or, alternatively, for makeup water for a steam generator. Alternate streams for these purposes are indicated at 100 and 102, respectively. The oil stream leaving the flotation cell is a recycle stream and it passes by pump 104 for recycling as stream 76.
Sand slurry 94 is pumped to settling ponds where sand will be precipitated and retained water and oil returned to the process plant. Surplus water not required for the sand slurry mix is directed to settling ponds for skimming remaining oil contaminants and for final settling before being returned to a feed water treatment facility of the plant or a water disposal facility.
Water pumped to flotation cell 90 is air injected to cause any remaining oil particles or sediment to float to the surface. These oil particles or sediment are skimmed resulting in very clean water. Water can be further purified by pumping it through diatomaceous earth filters. Water treatment may also include its softening to zero hardness.
Stream 62 entering topping unit 64 provides on-site generation of solvent for the recovery process. The topping unit may also employ visbreaking and reforming, the latter operations being employed to increase the aromaticity of the solvent and provide, where necessary, a sufficient volume of solvent to recover very heavy tars such as 6° to 8° A.P.I. tars. The products of the topping unit include heavy crude or tar, which leave the topping unit as a stream 106. The generated solvent leaves the topping unit as a stream 108 and goes to a solvent storage facility 110. This solvent is high in aromatic content. The high aromaticity is valuable in removal of asphaltenes from the deposit. A heavy pitch stream 112 from the topping unit provides fuel for a steam generator 114 and/or fired tubular heater 115. Noncondensable gases are taken from the topping unit as a stream 116. These gases can be used as fuel or can be disposed of in any other suitable manner. An excess reflux stream 118 is introduced into stream 76 to provide a diluent for the stream entering emulsion breaker 60.
Excess solvent may be taken from solvent storage as a stream 120, or earlier, as product solvent, which may be commingled with the heavy crude as tar or sold separately.
Stream from steam generator 114 passes through a line 122 and may be:
a. combined with solvent in the recovery of values from the deposit,
b. used in cyclic flooding of the deposit with steam and solvent, or,
c. used to heat solvent for the introduction of hot solvent in a solvent flooding production process.
For the production of hot solvent, steam passes through line 122, which is valved at 124, and into a heat exchanger 126 where it passes in heat exchange relationship with the aromatic solvent pumped through the heat exchanger from storage 110 by a pump 128. The solvent is heated to a temperature of from about 200° to about 650°F. The hot aromatic solvent is then introduced through a line 130 and into a line 132 downstream of a valve 134 in line 132. Line 132 goes to the injection wells. Steam in the heat exchanger is condensed and the steam condensate stream 138 is used as makeup for the steam generator and is introduced to thee generator in a stream 140.
Another alternative is to introduce the steam and solvent together. This may be done by a line 142 from solvent storage 110 which bypasses heat exchanger 126 and joins line 130 to the injection wells. In this instance a valve 144 in line 130 is closed and a valve 146 in line 142 is open. On the steam side, valve 124 is closed and valve 134 is open. The result is that both steam and solvent pass through line 132 to the injection wells.
For the introduction of steam and solvent in a cycle, valves 124 and 134 are alternately opened and closed on the steam side, and on the solvent side valves 144 and 146 are alternately opened and closed.
The steam generated from generator 114 is at high temperature and pressure and is of a quality substantially lower than 100%, say, 80%. The reason for this quality is that the water can prevent scale buildup in the steam generator and ancillary lines.
The maximum introduction pressure of steam into the formation is set by formation and overburden characteristics and for 2000 feet of overburden will average about 1500 p.s.i.g. This requires that the steam generator have a maximum working pressure of about 2500 p.s.i.g.
In cases where hot solvent alone is used to stimulate the reservoir the solvent may be heated in a fired tubular heater 115 and this will, in general, be required if the solvent is employed at high introduction temperatures. Fired tubular heater 115 may be used in conjunction with steam heating of the solvent, in most instances steam and/or solvent temperatures should be maximized for maximum stimulation.
While the process has been described in terms of Canadian tar sands, the process of this invention is useful in recovery of carbonaceous values from many other deposits. Tar sands are found in the United States, Venezuela and other countries.
The process of this invention may also be employed to recover values from old oil fields which have been depleted by primay production i.e., natural production followed by water flooding. These systems do not recover the tars present. These fields may still contain from 40 to 90% of their original carbonaceous values as tars.
Yet another example are oil and tar deposits in which the crude is too viscous to process by conventional means or which would be uneconomic to process. | Hydrocarbon products from viscous tar sands are recovered by continuously injecting a hot solvent containing relatively large amounts of aromatics into the formation. Alternatively, steam and solvent are cyclically and continuously injected into the formation to recover the values. The last stimulation is by steam so that solvent is recovered. A third alternative is to continuously inject a mixture of steam and solvent vapors and liquid into the formation. In all cases, the solvent, except perhaps for startup, is produced at the site, as in a conventional topping unit, which alternatively is combined with a conventional visbreaking or reforming unit to increase the volume and/or aromaticity of the solvent produced. | 4 |
FIELD OF THE INVENTION
The present invention relates to the generation of an at least ternary complex comprising a cationic latex particle, an anionic dye, and at least one anionic stabilizing agent and; a method for generating ink jet recordings that have superior waterfastness and improved light fastness and articles manufactured therewith.
BACKGROUND OF THE INVENTION
An ink jet recording system is a system wherein fine droplets of ink are jetted and deposited onto a recording medium such as paper sheet or film transparency. The droplets are deposited in such a manner as to generate pictorial images or symbols such as alphanumeric characters. Ink jet recording systems offer many positive features compared to previous imaging systems in that these systems are typically, performed at high speed, noiseless, with no further chemical development or fixing required, reproducible, inexpensive, and can produce either monotone or full color renditions. Furthermore, under appropriate conditions the quality of the ink jet image is comparable to photographic pictures but can be formed in a single step without the need for toxic chemicals. Lastly, if changes to the final imaged copy are required, it is relatively simple to make corrections within the stored computer information that is then outputted to the printer to rapidly print a new copy. Such a turnaround using conventional photographic processes would require elaborate and multiple steps.
The rendition or image generated by the ink jet process must meet stringent criteria if it is going to be of significant commercial value. These criteria include: high printed dot density (optical density), bright and true colors (chroma), and rapid absorption of ink even in areas where multiple inks are required to prevent running or blotting. Additionally, the edges of the printed dots must be sharp, and the images themselves must be waterfast and should not fade with time. Three elements dictate the final quality of the ink jet image; the hardware system that generates the ink droplets, the ink receiving (recording) media and finally the ink itself. Depending on the specific criteria of concern one or more of these elements may need to be optimized.
With regard to the concern for waterfastness and light induced fading, the two most critical elements are the recording media and the ink formulation. Because of environmental and health concerns it has been desirable to use aqueous formulations for ink jet inks and therefore, for compatibility reasons, hydrophilic type recording media are often employed. Although this system can address the health and environmental concerns by providing a relatively low toxicity ink media, it causes the imaged recording medium to be problematic to subsequent contact with moisture, specifically the media itself is prone to tackiness or blocking and the imaged inks will tend to “bleed” and not be waterfast. Since the ink formulations are aqueous based, the colorant/dye within the aqueous formulation must themselves have high water solubility. To achieve this characteristic, low molecular weight organic dyes having solubilizing groups were typically selected. Water insoluble pigments have also been used but have special problems such as clogging of nozzle jets and low chroma in the printed image. As already mentioned these dyes have significant water solubility and if there are no strong binding forces holding the dye to the receiver medium then the dye will partially redissolve or completely enter the liquid aqueous phase and diffuse and “bleed” or “run off” the recording media when the image is wet inadvertantly or upon exposure to outdoor environment, or under high humidity conditions. The resulting image smear or complete loss of image is unacceptable for many applications. Another long standing problem known in the industry is that low molecular weight organic dyes are known to degrade especially on exposure to light and air. This degradation is accelerated when dyes are deposited on a receiving media where the dye is exposed over a large surface area. Typically this phenomenon of “light induced fade” or oxidative degradation of these dyes occurs over a period of time. Obviously these characteristics, water and light fastness, are readily apparent to the customer and are highly desirable. This is especially so for media that is intended for outdoor exhibition.
Efforts to enhance waterfastness and improve image quality by lowering dot spread have often employed dye mordants such as cationic polymers. These mordants fix the dye to the ink receptive layer and fix the dye close to the site at which the inkjet drop has been deposited. Unfortunately, while enhancing waterfastness mordanting often this results in a decrease in the light stability of the dye, see for example “Effects of Mordant Type and Placement on Inkjet Receiver Performance”, L. Shaw-Klein, Final Program and Proceedings of IS&T NIP14:International Conference on Digital Printing Technologies (1998). It is further known in the ink jet technology literature, see U.S. Pat. No. 4,371,582, that anionic dyes can be fixed or mordanted to cationic latices via coulombic or electrostatic bonds. However the ′582 patent does not disclose the simultaneous binding of dyes and stabilizers to the same latex particle nor does it teach what benefits would derive from such a combination.
The light induced fading of dyes is a well known problem in a variety of technologies such as textiles and more recently in ink jet reproductions. This defect has inhibited the growth of ink jet technology into the display market which requires the exposure of ink jet prints to both indoor and outdoor lighting for long periods of time, see for example “Permanence of Ink-Jet Prints: A Multi-Aspect Affair”, M. Fryberg et al., Final Program and Proceedings of the Imaging Science and Technology (IS&T) Non Impact Printing (NIP) 13: International Conference on Digital Printing Technologies (1997)”, herein incorporated by reference in its entirety. Incorporating antioxidants and UV absorbers directly into an ink receiving layer has been disclosed, see for example U.S. Pat. No. 4,680,235. This approach however is inferior to the current invention which causes the dyes and stabilizers to remain proximate due to complexation, since in the case of the prior art, dye and stabilizer only interact infrequently and solely by random chance. The use of antioxidant hindered phenols, see U.S. Pat. No. 5,096,456, and metal complex stabilizers, see U.S. Pat. No. 4,655,785, to improve the lightfastness of dyed textile fibers is known in the prior art. In the ink jet prior art, increased efficiencies of light stabilization are reported to be afforded when a stabilizer is proximate to the dye, see for example U.S. Pat. No. 5,643,356, column 16, lines 40-45 and example 11, herein incorporated by reference in its entirety. In the ′356 patent, the technology employs a stabilizer covalently bound to a cyclodextrin via a chemical reaction, and then binding a dye to the modified cyclodextrin via an inclusion complex.
Having now disclosed the relevant problems associated with the current state of ink jet technology and the need for solutions to these problems the present invention will be described.
SUMMARY OF THE INVENTION
In light of the problems associated with the current state of ink jet technology the present invention addresses the specific areas of poor water fastness and poor light stability found when aqueous ink formulations are used to form ink jet images on hydrophilic receiver materials especially for materials that will be subjected to outdoor displays. Therefore, one object of the present invention is to design a waterfast ink jet image on a receiver material. Another object of the invention is to design a simple and direct method using cationic latices for proximally juxtaposing anionic dyes and stabilizers, without the need for chemical reactions, for the purpose of providing light stability to dyes that are inherently light sensitive. A yet further object of the invention is to enhance the light stability of mordanted dyes. A still further object is to enhance the light stability of dyes fixed to latex type mordants. Other objectives, aspects, features and advantages in addition to those discussed above will become more apparent from the following detailed description of the preferred embodiments when taken in conjunction with the claims appended hereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention comprises an at least ternary complex formed from the combination of a cationic or positively charged latex particle, an anionic organic colorant or dye, and at least one or more anionic stabilizing compound. Due to charge attraction the anionic dye and stabilizer components are tightly complexed to the surface of the cationic latex particle. When this occurs the dye and stabilizer molecules are brought into close proximity. This proximity allows for a highly efficient stabilization of the anionic dye especially to oxidative or light induced decomposition. It is known that the mechanism for such stabilization is often strongly dependent on distance between the dye and the stabilizer so the use of the cationic latex particle serves to provide the means for such close association. Without the cationic latex particle the anionic dye and the stabilizers would each be freely mobile and only under very high concentrations would association occur. Even under these highly concentrated conditions the anionic dye and stabilizer would have minimal interaction due to their similar electrical charges. Therefore the latex provides a means for bringing the dye and stabilizer into close proximity at very low effective concentrations. The cationic latex particle can range in size from 10 nm to 10 micron and may be of any three dimensional shape. Preferred size particles are between 50 nm and 500 nm, while most preferred is between 75 and 200 nm. The particle themselves may be homogeneous throughout or contain a seed component of different composition such as in a core-shell latex, furthermore the particle may also be hollow in its interior. In order to facilitate absorption of the ink vehicle into the ink receiving layer it is preferred that the latex particle not be filmforming under the conditions of manufacture and use, and therefore a Tg greater than 50C is recommended. A preferred cationic latex is available from Rohm and Haas and is commercially supplied as Latex PR-26. This latex is described in U.S. Pat. No. 5,312,863 herein incorporated by reference in its entirety, is composed of 28% solids dispersed in water and is comprised of 100 nm diameter particles having a significant percentage of the solids content composed of quaternized amino functionality (approximately 10 to 20% by weight). The latex is highly crosslinked with a Tg of about 65C, and is non filmforming. Examples of preferred cationic moities that are suitable for use in this invention include ammonium, alkyl ammonium, alkyl pyridinium, sulfonium, phosphonium, and the like. The latex may be produced by emulsion polymerization from any suitable monomer, for example, vinyl monomers, styrenic monomers, acrylate monomers (optionally bearing a cationic moiety) and methacrylate monomers (optionally bearing a cationic moiety), or any combination of these monomers provided that at least one of the monomers has or can be made to have (by subsequent alkylation) a cationic functionality. Specifically an amine monomer, once polymerized, can be quaternized.
There is no restriction on the dye except that it be an anionic organic dye. Most such dyes will contain ionized aromatic or aliphatic sulfonate, sulfate or carboxylate moieties on the dye nucleus (e.g., Tartrazine). Other examples of dyes useful in the invention include, Acid dyes, i.e., Acid Blue 45, Acid Black 2, Acid Red 8, Acid Red 52, Acid Yellow 23, Acid Blue 9, etc.; Reactive dyes, i.e., Reactive Black 5, Reactive Blue 2, Reactive Red 180 etc.; metal complex dyes ie. Reactive Blue 15, and Direct dyes such as Direct Blue 199, etc. Other suitable dyes can be found in U.S. Pat. No. 5,534,051, herein incorporated by reference in its entirety. It is preferred that the dye have a high extinction coefficient so that minimal amounts will provide sufficient optical density in the final imaged copy. Furthermore, since complexation with the cationic latex and later interaction with the recording medium may shift the spectral curve, it is recommended that the dyes should be selected based on their final chemical and physical environment and not based on curves obtained from an aqueous medium alone. The amount of dye that can be used in the present invention is dependent on the charge of the cationic latex. It is most desirable either to neutralize the cationic charges on the latex which precipitates the complex, or to maintain an overall excess of cationic charge (positive charge), i.e. sub-neutralize the latex which leaves the complex suspended. If the amount of anionic materials exceeds that required to precipitate the complex then the excess anionic materials will not be complexed to the cationic latex and this will be detrimental to the overall objectives of the invention. It is further desirable to have a 1:1 ratio of the anionic stabilizer to the anionic dye, however ratios from 1000:1 to 1:1000 are permissible. Working Example 1 reveals that approximately 1.3 gm of cationic Latex PR-26 can effectively complex with 1 mmole of anionic dye (Tartrazine) and 1 mmole of anionic stabilizer (Uvinul).
The stabilizers can be any anionic substances which are either an antioxidant, an excited state quencher, a UV absorber or a substance which can function in any combination of the stabilizing capacities. More specifically the antioxidant can be a sulfonated hindered phenol as disclosed in U.S. Pat. No. 5,096,456, herein incorporated by reference in its entirety, the excited state quencher can be a sulfonated metal complex as disclosed in U.S. Pat. No. 4,655,785 and J. Chem. Soc. Dalton Trans. (1985) p. 1147, both herein incorporated by reference. The UV absorbers can be a sulfonated o-hydroxy benzophenone as described in U.S. Pat. No. 5,181,935, herein incorporated by reference in its entirety and as marketed under the tradename, UVINUL, by the BASF Corporation. Other preferred UV absorbers include sulfonated o-hydroxybenzotriazoles as described in U.S. Pat. No. 5,181,935, herein incorporated by reference in its entirety, sulfonated o-hydroxy triazines, sulfonated hindered amines, as described in U.S. Pat. No. 5,281,707, herein incorporated by reference in its entirety, sulfonated triazines, sulfonated enones and the like. Multifunctional stabilizers which include on a given stabilizer molecule combinations of the above stabilizer types are also included. Both near and far UV absorbers are beneficial in the present invention.
In one embodiment of the invention, the ternary complex is formed by sub-neutralizing the cationic latex by first adding an aqueous solution of the dye to a suspension of the latex. After a period of time necessary to complex the dye to the latex, as evidenced by ultraviolet-visible spectroscopy, the anionic stabilizer is added to the suspended binary complex. In another embodiment of the invention the process of adding the stabilizer and the dye are reversed. It is also conceivable to add the dye and the stabilizer simultaneously to the cationic latex. It is noted specifically that any order of addition of the three components to generate the ternary complex is within the scope of this invention. If the ternary complex thus formed is sub-neutralized relative to the latex, then the ternary complex will remain in suspension, otherwise the complex will precipitate.
In one aspect of the invention it is envisioned that the sub-neutralized ternary complex will be part of the inkjet ink formulation and will be applied to the receiving layer of the recording media via an inkjet printhead. As will be further explained, another preferred embodiment is to add the anionic stabilizer to the cationic latex to form a sub-neutralized binary complex. This binary complex is then incorporated into an ink receiving layer, described hereinbelow, of a recording medium. In this embodiment there remain free cationic sites for the anionic dye that will later be provided by the ink. In this case the inkjet ink formulation will contain the dye, and upon application from an inkjet printhead, will form the ternary complex in-situ (i.e. within the receiver layer). In another embodiment the cationic latex is incorporated into the receiving layer as part of its coating formulation and both the anionic dye and the anionic stabilizer are formulated in the ink, the ternary complex forming in-situ in the imaged areas of the recording medium. GreLiter than ternary complexes, incorporating two or more anionic stabilizers simultaneously bound to the latex along with the dvc. are included within the scope of the invention. Lastly, the complexes might comprise additional components to assist in benefiting other aspects of the final imaged recording media.
When the ternary complex is used in an ink jet application a recording medium is necessary to generate the final image. This recording medium can be comprised of either film or paper support depending on the final mode of viewing, essentially no limitations, except as described hereinbelow, impact the selection of usable support materials. In the present invention standard paper, manufactured by traditional methods and containing standard additives, such as sizing agents, dye fixing agents, fluorescing agents, and hydration resisting agents can be acceptably used. Other acceptable paper supports include cast coated and resin coated papers. Paper or opaque film supports are used when the image is to be viewed under reflected light, in these cases the imaged recording medium can resemble a photographic print. If transparent film is used as the support, the image is typically viewed under transmitted light that passes from the obverse (imaged) side to the reverse side or vice versa. The transparent films can be used in an OHP (overhead projection) mode or in large display media that is intentionally backlit. In both cases, whether opaque or transparent film support is contemplated an additional receiving layer is required. This layer is coated on at least one surface of the film support to provide a receiving layer for the jetted ink formulation. The receiving layer is typically comprised of a hydrophilic polymeric material to absorb the applied ink formulation. Generally any polymer soluble in or swellable in water, or mixture of polymers which are so, for example gelatin and PVP, are common mixtures in inkjet receiver layers (IRLs). The preferred hydrophilic polymers include: poly(vinyl alcohol), poly(2-ethyl-2-oxazloline), hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methylcellulose, poly(vinyl pyrrolidone), copolymers of vinylpyrrolidone, gelatin, water-soluble polyesters. The hydrophilic material may also comprise a mixture of such materials. which may be fully compatible or may phase seperate. Either circumstance is within the accepted bounds of the invention. The hydrophilic polymer may be crosslinked to provide an insoluble, yet hydrophilic medium. An example of such a material is gelatin that has been crosslinked either prior to or during coating with materials such as bisvinyl sulfones dimethylol urea etc. Layer thickness for the hydrophilic receiving layer is not critical to the design of the invention but layer thicknesses of 0.5 to 200 micron are usable, and 1 to 40 micron are preferred and 2 to 10 micron are most preferred. It is also within the scope of this invention to have a multilayer coating on the support. For example, a two layer structure may consist of an upper image receiving layer and a lower layer which functions to assist in absorption of the ink vehicle. The receiving layer is the layer where the dye image is captured. The receiving layer may then be the uppermost layer or any of the inner layers between the uppermost layer and the support, the only requirement is that the applied ink formulation be able to diffuse to the receiver layer. The receiving layer may optionally contain other components to enhance the objectives of the invention. Such components might include fillers to assist in absorption of the ink vehicle, fluorescing agents, antitacking agents such as hydrophobic resins such as SBR latex and polyvinyl acetate, antiblocking agents such as silica particles or polymeric beads such as polymethylmethacrylate. If the receiving layer is used in combination with a transparent film support for viewing images with transmitted light, it is particularly preferred that the components of the receiving layer do not diminish the optical transparency of the recording medium. Therefore the amount of antiblocking agents, in particular, is limited by this requirement.
In the case of a plain paper support, the receiving layer is optional since the paper, by itself, can act as a hydrophilic receiving layer. In this circumstance the objects of the invention would be incorporated within the paper during the paper making process. In the cases of cast coated and resin coated papers the objects of the invention would be incorporated into the ink receiving layer. In cases where “photoreal” prints are required it is anticipated that the paper support will be coated with a hydrophilic receiver layer of similar composition to that previously described for the film supports.
When a single receiver layer is coated on the support it is an optional feature of the present invention that an anticurl backcoat layer will be required to maintain flatness of the coated support under various relative humidity conditions.
When both sides of the support are coated with a receiver layer it is a preferred feature of the present invention that both sides can then be imaged with jetted ink. This is a most preferred embodiment for opaque supports.
The coating of the receiver layer can be performed by any of the known coating methods such as slot coating, cascade coating, curtain coating, air knife coating, blade coating dip coating, gravure coating, etc. The type of coating application will influence the coating formulation of the receiving layer but typically the formulation will comprise a surfactant package to assist in reducing coating defects and assist in uniform ink absorption during the imaging step, a material to modify the gloss characteristics of the coated recording medium, and a matting agent to relieve potential blocking problems.
In a preferred embodiment of the present invention it is envisioned that the sub-neutralized binary complex of cationic latex and anionic stabilizer will be incorporated into the ink receiving layer of all the film or the paper supports described hereinabove.
If the cationic latex or binary complex are not incorporated into the receiver layer then the aforementioned sub-neutralized ternary complex will be incorporated into the ink jet ink formulation that will be applied to the receiving layer of the support. In this preferred embodiment, a single ternary complex is required for a monochrome image or a minimum of three separate ternary complexes are required for full color renditions. Each separate ternary complex formulation would then be jetted from separate print heads.
The inks that are useful in the present invention comprise aqueous formulations including water or water/organic solvent. When solvents are employed they arc typically selected from the low molecular weight alcohols, ketones, ethers and esters. The ratio of water to solvent can be any ratio but it is preferred from environmental and safety reasons to have the minimum amount of solvent present in the formulation. Typically the concentration of organic solvent is selected by determining the minimum amount of solvent necessary to insure that other components in the ink, particularly the anionic dye, remain in solution and do not clog the printhead. A preferred ratio of solvent to water is 2:5, and a most preferred ratio is 1:10. In one preferred embodiment the ink formulations contain uncomplexed anionic dye. The anionic dyes, as described hereinabove, are selected from the large collection of organic and organometallic dyes encompassing direct, acid, food, and vat.dyes. Typically these dyes contain a water solubilizing functionality that is anionic in nature, such as sulfonate, sulfate, carboxylate, or phosphate, or may additionally contain polyethylene oxide moieties. The useful dyes for the present invention will have solubility in the aqueous solvent described hereinabove to provide sufficient optical density in the imaged recording media. Typical concentrations of the anionic dyes in the ink formulations are from about 1 to about 200 gm/l. Preferred concentrations are from about 3 to about 50 gm/l.
In the above embodiment the ternary complex comprising an anionic dye, an anionic stabilizing agent, and a sub-neutralized cationic latex described hereinabove is used in place of the uncomplexed anionic dye. This complex can be formed prior to inclusion into to ink formulation or in situ. The ternary complex is preferably held in dispersion form in the ink formulation, therefore the formulation should be designed, and should contain, additional components to eliminate the potential for settling of the complex. This is typically achieved by using cationic latex particles no larger than 500 nm. Preferred sizes in the current invention include from about 10 nm to about 400 nm, highly preferred sizes include from about 10 nm to about 200 nm, and most highly preferred sizes include from about 10 nm to 100 nm micron. The amount of ternary complexed latex will depend on there being sufficient dye concentration to provide an image with acceptable optical density in imaged areas of the recording medium. Useable concentrations range from about 3 gm/l to about 400 gm/l. Preferred concentrations range from about 10 gm/l to about 200 gm/l, and most preferred concentrations range from about 25 gm/l to about 100 gm/l.
The ink formulations can further contain additional components as is typically used in standard ink jet formulations, These components might include anticlogging agents such as polyhydric alcohols, organic or organometallic bactericides, surfactants for providing uniform coating application to the receiving layer of the recording medium and to assist in absorption of the complexed or uncomplexed dye to the receiving layer.
These ink formulations can be applied to the recording medium by using any ink jet print head devices including those comprising piezo, bubble jet, and thermal applicators.
WORKING EXAMPLES
Example 1
Suspensions of PR-26 latex were prepared in concentrations ranging from 0 to 30% solids. Two milliliters of each were then added to a 0.017M Tartrazine solution to afford the latex to dye ratios in the table below. Upon addition of the latex to the dye solution a precipitate was noted and the sample was centrifuged for two minutes. Following centrifugation, aliquots of the supernatant were removed, diluted and spectra recorded. A sharp decline in the optical density of the dye was found up to an equivalence point near 1.4 g latex/mmol dye. The appearance, beyond the equivalence point, of a longer wavelength absorbance and the absence of centrifugate, corresponds to the formation of the dispersed sub-neutralized binary latex dye complex.
Gms PR-26 Latex/mmol Tartrazine
Absorbance
λmax
0.0
0.7
426
0.75
0.4
426
1.25
0.04
426
1.6
0.58
434
2.0
0.6
434
2.4
0.62
434
2.6
0.64
434
Example 2
As per example 1, aqueous suspensions of PR-26 latex were prepared in concentrations ranging from 0 to 30% solids. To a 1% solution of Uvinul DS 49 stabilizer was added the aqueous suspensions to give the latex to Uvinul ratios in the table below. Again precipitation was noted and the samples were centrifuged for two minutes, aliquots of the supernatant were diluted and spectra recorded. The optical density results demonstrate that there is again a sharp decline in the optical density at an equivalence point near 1.3 g latex/mmol stabilizer. The rise in optical absorbance after the equivalence point and the absence of centrifugate corresponds to the reformation of the dispersed sub-neutralized latex-stabilizer binary complex.
Gms PR-26 Latex/mmol Uvinul
Absorbance
0.0
1.0
0.5
0.6
0.8
0.42
1.3
0.04
1.6
1.08
2.0
1.05
2.5
1.0
2.8
1.02
Example 3
A binary complex of Uvinul and PR-26 cationic latex was prepared having nearly one half of the cationic sites complexed with Uvinul. The amounts of latex and Uvinul were based on the previous Example 2 where the equivalence point was determined to be near 1.3 gms Latex/ mmol Uvinul. Therefore, for this example, a mixture of 2.6 gms Latex/mmol Uvinul was prepared (i.e. about half the sites were complexed). This sub-neutralized binary latex stabilizer complex was then used to titrate the Tartrazine dye. The data below reveals the equivalence point is now found near 2.7 gms latex complex/mmol Tartrazine, or about twice that for the latex itself. Thus both the dye and stabilizer are simultaneously bound to the latex particle affording the ternary complex of the invention.
Gms Latex complex/mmol Tartrazine
Absorbance (λmax 426 nm)
0.0
0.511
0.9
.241
1.8
0.041
2.72
0.030
4.55
0.480
6.37
0.496
8.19
0.550
Example 4
Two coatings were prepared on a resin coated paperbase Schoeller Tech 150. The coatings each had an underlayer coated from a solution of 8% acid ossein gelatin (Croda Colloids) using a #32 wire wound rod. After drying of the underlayers there was coated using a #10 wire wound rod on the dried underlayers:
A—An overcoat layer from a solution prepared by adding 8.8 cc of a PR-26 latex containing solution “A” to 50 cc of 1% acid ossein gelatin. The PR-26 latex containing solution “A” was prepared by adding 7 cc PR-26 latex to 50 cc DI water.
B—An overcoat layer from a solution prepared by adding 8.8 cc of a sub-neutralized latex-stabilizer complex solution “B” to 50 cc of 1% acid ossein gelatin. The sub-neutralized latex-stabilizer complex solution “B” was prepared by adding 7 cc PR-26 latex to 50 cc of 1% Uvinul DS 49 (note: 3 cc PR-26 gave the fully neutralized complex).
The above dried two layer coatings were then printed using an Iris 5015 inkjet printer with a test target which generated pure cyan, magenta, yellow and black scales. Samples of the printed areas were placed into the trays of an Atlas HPUV Fadeometer generating a measured light intensity of 5.9 watts/m 2 visible and 1.7 watts/m 2 UV containing light. The initial and 25 hour L* a* b* values were measured on a Hunter MiniScan XE instrument operating at D65 daylight and 10° observer, and are tabulated for the yellow dye 50% density patch.
Coating A
L*
a*
b*
Coating B
L*
a*
b*
Initial
89.67
−5.48
50.71
Initial
89.71
−5.78
52.95
25 Hours
92.58
−4.92
24.39
25 Hours
91.60
−6.11
37.79
The data demonstrate that the ternary complex of the invention has reduced the yellow dye fade in the inkjet printed image.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein. | The invention relates to the use of cationic latex particles that can complex with anionic dyes to provide water fastness and further to provide a medium in which inherently unstable anionic dyes can be brought in close proximity with other anionic components, by complexation to cationic latices, in order to stabilize the anionic dyes especially with regard to light and oxidative degradation. In particular this invention will provide for methods of generating waterfast and improved lightfast ink jet images. | 2 |
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/DE02/01250 which has an International filing date of Mar. 28, 2002, which designated the United States of America and which claims priority on German Patent Application numbers DE 101 17 844.1 filed Apr. 4, 2001 and DE 201 18 493.1 filed Nov. 7, 2001, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
The invention generally relates to the field of electrical/power switches, and is preferably applicable to the design configuration of a rigid member which is used as a contact mount for a contact.
BACKGROUND OF THE INVENTION
In a known electrical switch of this type, in which two or more contact levers which form the contact are held on the contact mount by way of a bearing bolt such that they can pivot, the contact mount has at least three supporting elements in order to support the bearing bolt radially (E 0 222 686 B1). The contact mount in this case includes a metal frame, which is formed from two side walls and from two or more bolts which connect the side walls. The metal frame is hinged via a coupling bolt on an insulating coupling element, which is used for coupling the contact mount to a switch drive. Two of the supporting elements, which are associated with the ends of the bearing bolt, are in this case formed by the side walls of the metal frame.
In order to prevent undesirable radial bending of the bearing bolt for the contact levers with as little complexity in terms of additional material as possible, two intermediate bearings for this contact mount, which are arranged between adjacent contact levers in the axially central region of the bearing bolt, form additional supporting elements by being hinged on the coupling bolt. In this case, aperture openings are required for the contact mount, for the intermediate bearings to pass through to the coupling bolt. Supporting elements which are integrated in this way in addition to the two outer supporting elements in the contact mount must be positioned for installation of the bearing bolt, owing to their capability to pivot about the coupling bolt.
SUMMARY OF THE INVENTION
Against the background of an electrical switch, an embodiment of the invention is based on an object of simplifying the production and installation of the contact mount.
According to an embodiment of the invention, an object may be achieved in that at least three of the supporting elements are in the form of part of a molding which forms the contact mount and is produced integrally. For the purposes of an embodiment of the invention, the expression an integrally produced molding should be understood as being a part in which two or more functional elements are connected in the course of a molding process, such as a stamping, injection-compression molding, casting, injection molding, compression molding or sintering process, to form a single component which is assembled such that it cannot be disconnected for installation purposes.
In the case of a refinement such as this, the three supporting elements are integrated rigidly in a predetermined position in the contact mount, as part of it. In this case, the three supporting elements are actually aligned with the axis of the bearing bolt during the production of the contact mount so that no tilting of the bearing bolt caused by tolerance discrepancies will in practice occur during operation of the switch. A bearing bolt which is supported in this way is also subject to only a small maximum amount of bending when high short-circuit or surge currents occur, and thus has a good capability to withstand high short-circuit and surge currents.
The novel switching contact arrangement may have a large number of contact levers, which are each subject to an individual tolerance discrepancy from a given nominal size, and intermediate bearings, which are possibly likewise subject to an individual tolerance discrepancy from their nominal size, but which may be part of the contact levers, since the number of contact levers is subdivided into subsets. Each of these is arranged axially bounded between two adjacent supporting elements. This axial bounding of the subsets of contact levers limits any axial movement of the contact levers in one subset, owing to the current forces which act between them, to the axial section of the bearing bolt which is bounded by the respective supporting elements. The maximum amount of movement is not greater than the sum of all the individual tolerance discrepancies of the contact levers and of the intermediate bearings, which may be present, in this subset. This makes it possible to geometrically associate the contact levers with contact force springs such that their spring force is not reduced by bending or tilting. The geometrically accurate association between the contact force springs and the contact levers thus also contributes to increasing the capability of the switching contact arrangement to withstand short-circuit and surge currents.
If the molding is at least partially in the form of a plastic molding, then there is no need for the coupling bolt to have an electrically insulating configuration. The mechanical strength of a plastic molding such as this can be increased by embedding at least one reinforcement element at least partially in the plastic molding. A thermosetting plastic which, for example, has fiber reinforcement is typically used for the plastic molding and a nonmagnetic steel, for example, is used for the reinforcement element. As an alternative to this, other pure plastics or, for example, plastics reinforced by ceramic or glass fibers can also be used for the plastic molding, and other metals or metal sheets can be used for the reinforcement element.
One preferred refinement of the novel switching contact arrangement provides for at least one of the supporting elements to have a metal part which is at least partially embedded in the plastic molding.
A metal part such as this may be part of the reinforcement element, thus at the same time increasing the mechanical strength of that part of the contact mount which forms the supporting element.
If the metal part is in the form of a metal sheet, for example composed of nonmagnetic sheet steel, a first subregion of which, which has undercuts, is embedded in the plastic molding and a second subregion of which, which is provided with a hole for the bearing bolt, projects out of the plastic molding. This then advantageously allows the cross section of the supporting element to be reduced such that it is no broader than the distance between the contact levers that is required for separation of the contact levers and thus does not lead to any additional broadening of the contact mount.
A further advantageous refinement of the novel switching contact arrangement provides for supporting elements which contain the metal parts to be at a distance from the coupling element in the axial direction of the bearing bolt if the contact mount is coupled to a switching shaft, which can be rotated using a switch drive, via a metallic coupling element. This makes it possible to avoid accidental energizing and problems relating to the insulation between the contact mount and the switch drive, in a simple manner. In this refinement, the entire available material depth of the contact mount transversely with respect to the bearing bolt can be used for the rigid embedding of a first subregion of a supporting element which is in the form of a metal sheet.
If a holder for the shielding body is provided on at least one of the supporting elements for a contact mount which is equipped with the shielding body, then this provides additional support for the shielding body against the gas pressure which occurred during switching. In a refinement such as this, side mounting limbs, which rest on the contact mount, are designed to be smaller owing to the reduced load, or may possibly be omitted.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description of preferred embodiments given hereinbelow and the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, wherein FIGS. 1 to 9 show a number of exemplary embodiments of the novel switching contact arrangement and wherein:
FIG. 1 shows a schematic section illustration of a low-voltage circuit breaker with a switching contact arrangement which comprises a stationary contact assembly and a moving contact assembly,
FIG. 2 shows a moving contact assembly with a first embodiment of a contact mount which is at least partially in the form of a plastic molding,
FIG. 3 shows a reinforcement element, which may be embedded in the plastic molding of the contact mount shown in FIG. 2 ,
FIG. 4 shows a second embodiment of a contact mount which is at least partially in the form of a plastic molding, and in which supporting elements in the form of a metal sheet are partially embedded in the plastic molding,
FIG. 5 shows a section illustration, transversely with respect to the direction of the bearing bolt, through the contact mount shown in FIG. 4 ,
FIG. 6 shows a reinforcement element which may be embedded in the plastic molding of the contact mount in FIG. 4 ,
FIG. 7 shows a section illustration, transversely with respect to the direction of the bearing bolt, through a contact mount with an embedded reinforcement element as shown in FIG. 6 ,
FIG. 8 shows a further section illustration through the contact mount illustrated in FIG. 4 along the line A—A in FIG. 5 , and
FIG. 9 shows the contact lever mount as shown in FIG. 4 with a shielding body.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The electrical switch which is shown in FIG. 1 and is used in low-voltage power supply systems for voltage ranges up to about 1 000 V has a switch pole enclosure 1 in which switching chambers 2 are formed alongside one another, depending on the number of poles required. A switching shaft 4 , which can be rotated by way of a switch drive 3 , is used to operate the switching contact arrangement jointly, each of which includes a stationary contact assembly 5 and a moving contact assembly 6 . For this purpose, two levers 7 which project radially from the switching shaft 4 (see FIG. 8 ) are coupled to a metallic coupling element which is hinged on the moving contact assembly 6 . The contact assemblies 5 , 6 are connected in a known manner to externally accessible connecting rails 9 , 10 . Two exemplary embodiments 6 a and 6 b of the moving contact assembly 6 will be explained in the following text with reference to FIGS. 2 and 3 and, respectively, FIGS. 4 to 9 .
As can be seen in more detail from FIG. 2 , the moving contact assembly 6 a has a contact mount 11 which has a plastic molding 12 in the form of an integrally produced molding, which was formed in the course of a stamping process, with a reinforcement element as shown in FIG. 3 being embedded in it. The contact mount is mounted in the enclosure 1 (see FIG. 1 ) such that it can pivot, and can be moved via the switching shaft 4 and by use of the switch drive 3 , of which FIG. 1 shows only one drive run 15 that is supported on a spring stalk 14 relative to the stationary contact assembly 5 to a connected position and to a disconnected position.
Two or more contact levers 16 , 17 , which are arranged parallel to one another, on the contact mount 11 can pivot relative to the contact mount 11 about a bearing bolt 18 . Contact force springs 19 (see FIG. 1 ) ensure that the contact levers 16 , 17 are prestressed in the direction of the stationary contact assembly 5 . Flexible conductors 20 in the form of braids or strips are used for connecting the contact levers 16 , 17 to the lower connecting rail 10 in such a way as to guarantee that the contact levers 16 , 17 and the contact mount 11 can move without any impediment during the switching movements.
The number of contact levers 16 , 17 which are fitted to the contact mount 11 depends on the magnitude of the current which the circuit breaker is intended to carry during operation. As can be seen from FIG. 2 , of the total of 22 contact levers that are provided, 8 contact levers 16 are designed to be shorter and have only one contact area 21 , which have no leading contact area 22 and no arcing horn 23 in the same way as the other contact levers 17 .
During operation, all the contact levers are held between side pieces 24 a , 24 b of the contact mount 11 , which point transversely with respect to the bearing bolt 18 . These side pieces 24 a , 24 b , which are provided with holding openings 25 a , 25 b for the bearing bolt 18 form a first and a second supporting element for the ends of the bearing bolt, via which the bearing bolt is positioned axially and is supported radially. A part 29 a or 29 b of the reinforcement element 13 (see FIG. 3 ) can extend in each of these side pieces, and has an aperture 27 a or 27 b , respectively, for the bearing bolt. In the downward direction, the side pieces 24 a , 24 b merge into bearing arms 26 for the contact mount 11 .
The relatively large width of the switching contact arrangement indicates that the section of the bearing bolt which runs between the two side supporting elements 24 a , 24 b is subjected to a relatively severe bending load when further forces in addition to the forces of the contact force springs 19 are caused by a heavy current, such as a short-circuit or surge current, when the switching contact arrangement is in the closed state.
Bending of this section of the bearing bolt is prevented by way of an additional, third supporting element, which supports the bearing bolt axially in the center. This third supporting element is formed by a contact mount rib 28 , which is provided with a holding opening 25 c (which cannot be seen in the figure) for the bearing bolt 18 and points transversely with respect to the bearing bolt, with a metal part 29 c (which is completely embedded in the plastic molding 12 and has an aperture 27 c for the bearing bolt) extending in the rib 28 and being part of the reinforcement element 13 (see FIG. 3 ).
Of the second exemplary embodiment 6 b of the moving contact group, FIG. 4 shows only a second embodiment 30 of the contact mount. In this contact mount 30 , two supporting elements, which are in the form of metal sheets 31 , are used to radially support that section of the bearing bolt which runs between two supporting elements that are in the form of side pieces 32 a , 32 b . A first subregion 33 of the two central supporting elements 31 is embedded in the plastic molding 34 of the contact mount 30 , and together with a second subregion 35 of the two central supporting elements 31 , projects out of the plastic molding.
As can be seen in FIG. 5 , the metal sheets 31 have undercuts 36 in the first subregion 33 which is embedded in the plastic molding, and these are used to anchor the respective metal sheet in the plastic molding securely even when the bearing bolt is subjected to a high bending load. The second subregion 35 , which is provided with a hole 38 for the bearing bolt 37 to pass through, also has a recess 39 , which is used to hold a shielding body 40 that is not shown in any more detail in FIG. 9 . As is shown in FIG. 7 , two reinforcement elements 41 , 42 may be embedded in the plastic molding of the contact mount, and one of these is illustrated in FIG. 6 .
As can be seen from FIG. 8 , the two metal sheets 31 are at a distance from the metallic coupling element 8 (see FIG. 1 ) in the axial direction, in order to avoid accidental energizing between the bearing bolt (which is at a low-voltage potential) of the contact levers and the metallic coupling element 8 (which is at ground potential), and thus the switch drive.
As can be seen from FIG. 9 , tongues 43 are integrally formed on the shielding body 40 , which protects the pivoting area of the contact mount 30 and further switch parts (which are not shown in any more detail but are arranged underneath the contact areas 21 , 22 (see FIG. 1 )) against erosion products that fall out and against condenser switching gases, and these tongues 43 engage in the recesses 39 which are provided on the metal sheets (see also FIG. 5 ). In consequence, the shielding body 40 is supported against the gas pressure which occurs during switching processes, in such a way that its mounting limbs 44 a , 44 b , which are held in the side on the contact mount, are less severely loaded.
Exemplary embodiments 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 present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A switching contact arrangement is for a power switch, wherein a plurality of contact levers are pivoted on a contact support via a bearing pin. The contact support is provided with at least three support elements for radially supporting the bearing pin. In order to simplify production of the contact support, at least three of the support elements are configured as a one-piece shaped element that forms the contact support. At least one of the support elements can have a metal element that is at least partially embedded in a plastic shaped element of the contact support. The metal element can be configured as a sheet metal part. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
(i) Soula and Linguenheld application, Ser. No. 148,590, filed May 12, 1980, and assigned to the assignee hereof; and
(ii) Soula and Michelet application, Ser. No. 161,516, filed June 20, 1980, also assigned to the assignee hereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved process for the preparation of aryl ethers and thioethers, and, more especially, to a process for the preparation of benzenoid ethers and thioethers by reacting an activated halobenzene with an anionic, organic oxygen-containing or sulfur-containing reactant.
By the term "activated halobenzene" as utilized herein, there is intended a halobenzene containing an electron-attracting group in the ortho- or para-position to the halogen, and by the term "anionic, organic oxygen-containing or sulfur-containing reactant" there is intended a reactant of the type RO - M + or RS - M + , R being a hydrocarbon radical.
2. Description of the Prior Art
Known to the art is a process for the preparation of compounds of the general formula A--Y--A'--Z n , in which A and A' represent substituted or unsubstituted aryl radicals, Z is an electron-attracting group and Y is O, S or SO 2 , n being between 1 and 3. In accordance with this process, described in French Application No. 76/13,943 (U.S. Pat. No. 2,311,004), a compound of the formula A-YMe, in which Me represents an alkali metal or NH 4 , is reacted with a compound of the formula X--A--Z n , in which X is a halogen or an activated nitro group.
The reaction is carried out in a two-phase system, one of the phases being water or an alkaline aqueous medium, in which the compound A-YMe is reacted, and the other consisting of a solution of the compound X--A'--Z n in one or more water-immiscible solvents. The reaction is carried out in the presence of quaternary ammonium or phosphonium derivatives as catalysts.
The main disadvantages of this type of process are associated with the use of an aqueous phase. The presence of water mandates operation under pressure when the reaction temperature is above 100° C. Furthermore, it involves the use of water-immiscible solvents which do not form emulsions with water in the presence of quaternary ammonium derivatives. Yet, some reactions only take place with appreciable yields when using aprotic polar solvents, such as sulfolane, dimethylsulfoxide and N-methylpyrrolidone, which are water-miscible solvents. It too will be appreciated that the large amount of water required, as is apparent from the examples in the abovementioned French patent application, makes it necessary to employ large reactors.
Further disadvantages result from the use of quaternary ammonium or phosphonium derivatives as catalysts. In fact, those skilled in the art are well aware that such catalysts easily degrade when exposed to temperatures above about 130° C. Furthermore, serious difficulties are encountered, from an industrial point of view, in separating the catalyst from the reaction product.
An additional disadvantage of this type of prior art process lies in the fact that it does not permit the use of alcoholates which degrade in the presence of water.
SUMMARY OF THE INVENTION
Accordingly, a major object of the present invention is the provision of an improved process for the preparation of benzenoid ethers and thioethers by reacting an activated halobenzene with an anionic, organic oxygen-containing or sulfur-containing reactant, in the absence of water, and which process conveniently avoids those drawbacks and disadvantages above outlined.
Another object of the invention is to provide an improved process which can be conducted in the presence of a catalyst which does not degrade at elevated temperature.
Yet another object of the invention is to provide an improved process which permits of the easy separation and recovery of the catalyst from the reaction medium.
Briefly, the present invention features a process for the preparation of benzenoid ethers and thioethers by reacting an activated halobenzene with an anionic, organic oxygen-containing or sulfur-containing reactant, characterized in that the reaction is conducted in the presence of at least one sequestering agent having the structural formula:
N--CHR.sub.1 --CHR.sub.2 --O--CHR.sub.3 --CHR.sub.4 --O).sub.n R.sub.5 ].sub.3 (I)
in which n is an integer which is greater than or equal to 0 and less than or equal to about 10 (0≦n≦10), R 1 , R 2 , R 3 and R 4 , which are identical or different, each represent a hydrogen atom or an alkyl radical having from 1 to 4 carbon atoms, and R 5 represents an alkyl or cycloalkyl radical having from 1 to 12 carbon atoms, a phenyl radical or a radical --C m H 2m --φ or C m H 2m+1 --φ--, in which m ranges from 1 to 12 (1 ≦m≦12).
The subject reaction can be carried out either in the presence or absence of a solvent. If no auxiliary solvent is used, it is the activated halobenzene itself which serves as the solvent.
DETAILED DESCRIPTION OF THE INVENTION
More particularly according to this invention, it has now been determined that the sequestering agent of the formula (I) forms, with the anionic, organic oxygen-containing or sulfur-containing reactant, a complex which is soluble in solvents in which the anionic, organic oxygen-containing or sulfur-containing reactant is insoluble, or is very sparingly soluble in the uncomplexed state. It will be apparent that, as a result of the immediately aforesaid, the process according to the invention enables employing solvents, the use of which was not heretofore technically feasible. This is all the more advantageous because it becomes possible to use solvents which are much easier to handle on an industrial scale than the solvents previously used. A further advantage of the invention is that, although not yet completely understood in detail, it would appear that the complexation due to the sequestering agent of the formula (I) itself activates the reaction system.
According to a preferred embodiment of the invention, a sequestering agent of the formula (I) is used in which R 1 , R 2 , R 3 and R 4 represent a hydrogen atom or a methyl radical, R 5 and n being as above defined.
Among such sequestering agents, it is even more particularly preferred to employ those in which n is greater than or equal to 0 and less than or equal to 6 and in which R 5 represents an alkyl radical having from 1 to 4 carbon atoms.
The following sequestering agents are noted as illustrative:
[1] tris-(3-oxabutyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3,
[2] tris-(3,6-dioxaheptyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3,
[3] tris-(3,6,9-trioxadecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3,
[4] tris-(3,6-dioxaoctyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3,
[5] tris-(3,6,9-trioxaundecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3,
[6] tris-(3,6-dioxanonyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3,
[7] tris-(3,6,9-trioxadodecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3
[8] tris-(3,6-dioxadecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3,
[9] tris-(3,6,9-trioxatridecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3,
[10] tris-(3,6,9,12-tetraoxatridecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 O).sub.3 CH.sub.3 ].sub.3,
[11] tris-(3,6,9,12,15,18-hexaoxanonadecyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--.sub.5 CH.sub.3 ].sub.3,
[12] tris-(3,6-dioxa-4-methylheptyl)-amine of the formula:
N--CH.sub.2 --CH.sub.2 --O--CH(CH.sub.3)--CH.sub.2 --O--CH.sub.3 ].sub.3 and
[13] tris-(3,6-dioxa-2,4-dimethylheptyl)-amine of the formula:
N--CH.sub.2 --CH(CH.sub.3)--O--CH(CH.sub.3)CH.sub.2 --O--CH.sub.3 ].sub.3.
The amine sequestering agent utilized in the process according to the invention are per se known to the prior art. Thus, French Pat. No. 1,302,365 describes the preparation of the tertiary amines N--CH 2 --CH 2 --O--CH 3 ) 3 and N--CH 2 --CH 2 --O--CH 2 --CH 2 --O--CH 3 ) 3 as by-products from the synthesis of the corresponding primary and secondary amines, such primary and secondary amines being valuable as intermediates in the synthesis of pharmaceuticals, as corrosion inhibitors, as intermediates in the synthesis of chemical products of value in agriculture, and as emulsifiers. It will also be appreciated, though, that the prior art, including the aforenoted French Pat. No. 1,302,365, is conspicuously devoid of any suggestion that the topic amines could be utilized in any reaction within the ambit of this invention.
Characteristic activated halobenzenes reacted in accordance with the process of the invention have the structural formula: ##STR1## in which X represents a halogen atom (F, Cl, Br or I), Z represents at least one electron-attracting group selected from the group comprising NO 2 , CN, SO 3 M, CO 2 M and CF 3 , in which M represents an alkali metal, Z being located in the ortho- and/or para-position to the group X, R 6 represents at least one substituent selected from the group comprising:
hydrogen,
alkyl and cycloalkyl radicals having from 1 to 12 carbon atoms,
alkenyl radicals having from 3 to 12 carbon atoms, such as, for example, propenyl, nonyl and dodecyl radicals,
the radicals of the formulae C m H 2m+1 --φ--, C m H 2m-1 --φ-- and φ--C m H 2m --, in which m is an integer ranging from 1 to 12 (1≦m≦12) and in which the phenyl moiety φ can either be substituted or unsubstituted,
alkoxy radicals having from 1 to 12 carbon atoms and phenoxy radicals,
the radicals --C m H 2m --OH and --C m H 2m OR, in which m is an integer ranging from 1 to 12 (1≦m≦12) and in which R is an alkyl radical having from 1 to 12 carbon atoms or a phenyl radical,
alkylthio radicals having from 1 to 12 carbon atoms and phenylthio radicals,
the radicals C p H 2p+1-q F q , p ranging from 1 to 4 (1≦p≦4) and q ranging from 3 to 9 (3≦p≦9), such as, for example, --CF 3 and --CH 2 --CF 3 ,
the radicals ##STR2## in which R is an alkyl radical having from 1 to 12 carbon atoms or a phenyl radical,
the radicals Cl, F and Br, and
the radicals --NO 2 , --SO 3 M, --CN, --CO 2 M, --CO 2 R, --COR and --COH, in which M represents an alkali metal and in which R represents an alkyl radical having from 1 to 12 carbon atoms or a phenyl radical, and n is an integer which can be equal to 1, 2 or 3 (1≦n≦3).
The anionic oxygen-containing or sulfur-containing reactants employed in the process of the invention have the structural formula:
R.sub.7 --A.sup.- M.sup.+ (III)
in which R 7 represents a radical selected from the group comprising linear or branched chain alkyl radicals and cycloalkyl radicals which have from 1 to 12 carbon atoms and are optionally substituted, and optionally substituted aryl radicals having from 6 to 10 carbon atoms, A represents oxygen or sulfur and M + represents a monovalent or divalent cation comprising an alkali metal or alkaline earth metal, or the ammonium cation NH 4 + .
The compounds of the formula III to which the process according to the invention more particularly, but not exclusively, applies are those in which R 7 represents a radical selected from the group comprising linear or branched chain alkyl radicals and cycloalkyl radicals which have from 1 to 6 carbon atoms and are optionally substituted, and phenyl and naphthyl radicals which are optionally substituted by at least one of the following radicals: alkyl radicals having from 1 to 6 carbon atoms, phenyl radicals, halo, nitro, cyano, amido and amino radicals, alkoxy radicals having from 1 to 6 carbon atoms, phenoxy radicals, alkylamino radicals having from 1 to 6 carbon atoms, phenylamino radicals, alkylamido radicals having from 1 to 6 carbon atoms and phenylamido radicals.
The following compounds are exemplary of the compounds of the formula II: ##STR3##
Exemplary of compounds of the formula III are the alkali metal or ammonium salts of the following compounds: alcohols, such as methanol, ethanol, isopropanol and butanol, cyclic alcohols, such as cyclohexanol and furfurol, phenols, such as phenol, alkylphenols, such as o-, p- and m-cresol, 2-isopropyl-4-methylphenol and 2-isopropyl-5-methylphenol, dodecylphenol and nonylphenol, arylphenols, such as paraphenylphenol, monohalophenols, such as o-, p- and m-chlorophenol and the corresponding bromo, iodo and fluoro compounds, polyhalophenols, such as dichlorophenols, trichlorophenols, tetrachlorophenols and pentachlorophenol, "mixed" dihalophenols, such as 3-chloro-4-bromophenol, 3-chloro-4-fluorophenol, 3-chloro-5-fluorophenol and equivalent compounds, haloalkylphenols, such as 3-trifluoromethylphenol and 4-trifluoromethylphenol, alkylhalophenols, such as 2-methyl-4-chlorophenol and 2, 4-dimethyl-5-chlorophenol, aminophenols, such as 3-aminophenol, 4-aminophenol, 2-methyl-4-aminophenol and 2-(N,N-dimethylamino)phenol, cyanophenols, such as 2-cyanophenol and 4-cyanophenol, nitrophenols, such as o-, p- and m-nitrophenol, 2-methyl-3-nitrophenol, 2-methyl-4-nitrophenol and 2,4-dinitrophenol, amidophenols, such as o-, p- and m-amidophenol, alkoxyphenols, such as 3-methoxyphenol, 2-methoxyphenol and 4-methoxyphenol, phenoxyphenols, such as o-, m- and p-phenoxyphenol, alkylamidophenols, such as 2-dimethylamidophenol, thioalcohols, such as methylmercaptan and ethylmercaptan, thiophenols, such as p-chlorothiophenol, p-aminothiophenol, 2-methylthiophenol, 3-methylthiophenol, 4-methylthiophenol and 2,4-dimethylthiophenol, and mercaptobenzothiazoles.
The selection of the most suitable sequestering agent for carrying out the process according to the invention is made with regard to the size of the cation M + (compound of the formula III). The larger the cation, the larger must be the number of oxygen atoms present in the molecule of the sequestering agent. Thus, if a potassium phenolate is used, it is preferred to use tris-(3,6,9-trioxadecyl)-amine, whereas tris-(3,6-dioxaheptyl)-amine is preferred in the case of the corresponding sodium salt.
The auxiliary solvent, if such a solvent is used, must satisfy a certain number of conditions; firstly, it must solubilize the sequestering agent (the latter is soluble in the majority of customary solvents); secondly, it must be chemically inert vis-a-vis the salts to be dissolved. It must also be noted that, in order to achieve the best results from the process according to the invention, the more marked the apolar character of the solvent chosen, the more marked must be the lipophilic character of the sequestering agent (namely, the greater must be the number of carbon atoms present in the sequestering agent).
Examples of the auxiliary solvents which can be used are acetonitrile, N-methylpyrrolidone, chlorobenzene, o-dichlorobenzene, dimethysulfoxide, diphenyl ether, dioxane and ethylene glycol polyethers (commonly referred to as "glymes").
The compounds II and III can be used in stoichiometric amounts or in excess relative to the stoichiometric amount. According to a preferred embodiment, a 20% excess is used, relative to the stoichiometry of one or the other of the compounds II and III.
The amount of the amine of the formula I employed can be between about 1 and about 100 mols per 100 mols of the compound of the formula III. It is preferred to use between 1 and 15 mols of amine per 100 mols of compound III.
If an auxiliary solvent is used, it is employed in an amount such that it contains from about 10 to 500% of its weight of the compound of the formula III.
The process according to the invention is carried out at a temperature between about 50° C. and about 200° C., preferably between about 80° C. and about 160° C.
The pressure is not critical. The process is generally carried out under atmospheric pressure, although lower or higher pressures are not excluded.
The compounds prepared in accordance with the process of the invention have the following general formulae IV: ##STR4## in which R 6 , R 7 , A and Z are as above defined.
The following compounds are exemplary of the compounds corresponding to one of the formulae IVa-d: ##STR5##
The subject compounds are notable intermediates for the synthesis of organic compounds which can be used as plantprotection agents.
The sequestering agents of the formula I employed in the process according to the invention can be prepared by condensing a salt of the formula: ##STR6## in which R 3 , R 4 , R 5 and n are as above defined and in which M represents an alkali metal atom selected from among sodium, potassium and lithium, either with an amine of the general formula: ##STR7## in which R 1 and R 2 are as above defined and X represents chlorine or bromine, or with the corresponding hydrochloride or hydrobromide.
The molar ratio alkali metal salt/amine is between about 3 and about 5.
The condensation is carried out at a temperature between 100° and 150° C. for 1 to 15 hours, in the presence of a solvent which can be, for example, chlorobenzene or, preferably, the ethylene glycol monoalkyl ether of the formula R 5 --(O--CHR 4 --CHR 3 ) n --OH.
The process is preferably carried out in such fashion that the solution contains from 2 to 5 mols of alkali metal salt per liter of solvent.
The mixture upon completion of the reaction essentially consists of the tertiary amine of the formula: ##STR8## but also contains a small proportion of the corresponding secondary amine: ##STR9## and traces of the primary amine: ##STR10##
The tertiary, secondary and primary amines are typically present in the ratio 90:8:2, respectively, after distillation.
In the process according to the invention, the above mixture obtained after a first distillation, namely, containing the three types of amine, can be used directly.
In order to achieve better results consistent with the invention, it is preferred to carry out a more thorough distillation of the above mixture in order to obtain an essentially pure tertiary amine.
In order to further illustrate the present invention and the advantages thereof, the following specific examples are given, it being understood that same are intended only as illustrative and in nowise limitative.
EXAMPLE 1
Reaction of φO - Na + with para-nitrochlorobenzene, in order to prepare para-phenoxynitrobenzene having the structural formula: ##STR11## in the presence of tris-(3,6-dioxaheptyl)-amine in dichlorobenzene.
100 cm 3 of chlorobenzene, 32 g (0.2 mol) of para-nitrochlorobenzene, 23 g (0.2 mol) of sodium phenate and 3.7 g (0.01 mol) of tris-(3,6-dioxaoctyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated at 130° C. for 9 hours. The yield of the reaction was 95% in respect of the para-phenoxynitrobenzene isolated.
COMPARATIVE EXAMPLE
Under the same operating conditions as above, but in the absence of tris-(3,6-dioxaoctyl)-amine, the yield of the reaction was 3%.
EXAMPLE 2
Reaction of sodium 2, 4-dichlorophenate having the formula: ##STR12## with para-nitrochlorobenzene, in order to prepare para-(2,4-dichlorphenoxy)-nitrobenzene having the formula: ##STR13## in the presence of tris-(3,6-dioxaheptyl)-amine in dichlorobenzene.
100 cm 3 of monochlorobenzene, 15.7 g (0.1 mol) of para-chloronitrobenzene, 27.8 g (0.16 mol) of sodium 2,4-dichlorophenate and 2.3 g (0.007 mol) of tris-(3,6-dioxaheptyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated at the reflux temperature of the chlorobenzene for 12 hours. The yield of the reaction was 68%.
COMPARATIVE EXAMPLE
In the absence of tris-(3,6-dioxaheptyl)-amine, but otherwise conducting the reaction as above, the yield was 8%.
EXAMPLE 3
Reaction of potassium para-nitrophenate having the formula: ##STR14## with para-fluoronitrobenzene, in order to prepare 4,4'-dinitrodiphenyl ether having the formula: ##STR15## in the presence of tris-(3,6,9-trioxadecyl)-amine in o-dichlorobenzene.
200 cm 3 of ortho-dichlorobenzene, 14.1 g (0.1 mol) of para-fluoronitrobenzene, 17.7 g (0.1 mol) of potassium para-nitrophenated and 4.55 g (0.01 mol) of tris-(3,6,9-trioxadecyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated at the reflux temperature of the ortho-dichlorobenzene for 10 hours. The yield of the reaction was 87%.
EXAMPLE 4
Reaction of potassium para-nitrophenate with ortho-nitrofluorobenzene having the formula: ##STR16## in order to prepare 2,4'-dinitrodiphenyl ether having the formula: ##STR17## in the presence of tris-(3,6,9-trioxadecyl)-amine in ortho-dichlorobenzene.
200 cm 3 of ortho-dichlorobenzene, 14.1 g (0.1 mol) of ortho-fluoronitrobenzene, 17.7 g (0.1 mol) of potassium para-nitrophenate and 4.55 g (0.01 mol) of tris-(3,6,9-trioxadecyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated at the reflux temperature of the ortho-dichlorobenzene for 10 hours. After cooling, the salts were removed and the solvent was then evaporated off. The yield of the reaction was 85%.
EXAMPLE 5
Reaction of potassium ortho-nitrophenate having the formula: ##STR18## with ortho-nitrofluorbenzene, in order to prepare 2,2'-dinitrodiphenyl ether having the formula: ##STR19## in the presence of tris-(3,6,9-trioxadecyl)-amine in o-dichlorobenzene.
200 cm 3 of ortho-dichlorobenzene, 14.1 g (0.1 mol) of ortho-fluoronitrobenzene, 17.7 g (0.1 mol) of potassium ortho-nitrophenate and 4.55 g (0.01 mol) of tris-(3,6,9-trioxadecyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated at the reflux temperature of the ortho-dichlorobenzene for 8 hours. After cooling the salts were removed and the solvent was then evaporated off. The yield of the reaction was 82%.
EXAMPLE 6
Reaction of sodium para-aminophenate with para-nitrochlorobenzene, in order to prepare para-(4-aminophenoxy)-nitrobenzene having the formula: ##STR20## in the presence of tris-(3,6-dioxaheptyl)-amine in chlorobenzene.
100 cm 3 of chlorobenzene, 15.7 g (0.1 mol) of para-chloronitrobenzene, 13.1 g (0.1 mol) of sodium para-aminophenate and 1.6 g (0.005 mol) of tris-(3,6-dioxaheptyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated at 130° C. for 13 hours and the resulting solution was then filtered hot. After filtration, 300 cm 3 of hexane were added and this effected the precipitation of the para-(4-aminophenoxy)-nitrobenzene. The yield of the reaction was 83%.
EXAMPLE 7
Reaction of sodium thiomethylate having the formula: CH 3 S - Na + with para-nitrochlorobenzene, in order to prepare para-thiomethoxynitrobenzene having the formula: ##STR21## in the presence of tris-(3,6-dioxaheptyl)-amine in chlorobenzene.
1-liter of chlorobenzene, 157 g (1 mol) of para-nitrochlorobenzene, 140 g (2 mols) of sodium thiomethylate and 32 g (0.1 mol) of tris-(3,6-dioxaheptyl)-amine were successively introduced into a 2 liter three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The mixture was stirred and heated for 2 hours at the reflux temperature of the chlorobenzene and then cooled. The salts formed, and also the unconverted sodium thiomethylate, were removed by filtration and the chlorobenzene was evaporated off. The thiomethoxynitrobenzene was distilled. The yield of the reaction was 72%.
EXAMPLE 8
Reaction of potassium phenate with para-chlorobenzonitrile, in order to prepare para-phenoxybenzonitrile having the formula: ##STR22## in the presence of tris-(3,6,9-trioxadecyl)-amine in o-dichlorobenzene.
200 cm 3 of ortho-dichlorobenzene, 27.5 g (0.2 mol) of para-chlorobenzonitrile, 29.04 g (0.22 mol) of potassium phenate and 4.55 g (0.01 mol) of tris-(3,6,9-trioxadecyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser. The reaction mixture was stirred and heated at the reflux temperature of the ortho-dichlorobenzene for 8 hours. The salts formed were removed by filtration and the solvent was removed by distillation. The yield of the reaction was 85%.
COMPARATIVE EXAMPLE
Under the same operating conditions as above, but in the absence of tris-(3,6,9-trioxadecyl)-amine, the yield was only 3%.
EXAMPLE 9
Reaction of sodium phenate with 3-nitro-4-chlorotrifluoromethylbenzene, in order to prepare 3-mitro-4-phenoxytrifluoromethylbenzene having the formula: ##STR23## in the presence of tris-(3,6-dioxaheptyl)-amine in chlorobenzene.
200 cm 3 of chlorobenzene, 22.5 g (0.1 mol) of 3-nitro-4-chlorotrifluoromethylbenzene, 13 g (0.11 mol) of sodium phenate and 3.2 g (0.01 mol) of tris-(3,6-dioxaheptyl)-amine were successively introduced into a 500 ml three-necked round-bottomed flask equipped with a mechanical stirrer, a thermometer and a reflux condenser.
The mixture was stirred and heated at the reflux temperature of the chlorobenzene for 4 hours. After cooling, the salts were filtered off and the solvent was then evaporated off. The yield of the reaction was 92%.
COMPARATIVE EXAMPLE
In the absence of tris-(3,6-dioxaheptyl)-amine, but otherwise conducting the reaction as above, the yield of the reaction was 18%.
EXAMPLE 10
Preparation of tris-(3,6-dioxaheptyl)-amine:
(a) 380 g (5 mols) of 2-methoxyethanol were introduced into a one liter three-necked round-bottomed flask fitted with a mechanical stirrer, and a thermometer and a condenser. 23 g (1 mol) of sodium were added over the course of 3 hours, while maintaining the temperature of the mixture at 40° C.
(b) 51.6 g (namely, 0.215 mol) of tris-(2-chloroethyl)-amine hydrochloride were added to the above mixture. The mixture was subsequently heated at the reflux temperature of the 2-methoxyethanol (125° C.) for 12 hours and the solvent was then distilled under reduced pressure. The excess sodium 2-methoxyethanolate was neutralized by adding 11.6 cm 3 of aqueous HCl (10 N). The sodium chloride was filtered off and the solution was distilled.
EXAMPLE 11
Preparation of tris-(3,6,9-trioxadecyl)-amine:
600 g, namely, 5 mols, of diethylene glycol monomethyl ether (3,6-dioxaheptan-1-ol) were introduced into a 1 liter three-necked round-bottomed flask equipped with a mechanical stirrer, a condenser and a thermometer, and 23 g (1 mol) of sodium were then introduced in small portions in order to form sodium 3,6-dioxaheptanolate.
When the sodium had been totally converted, 51.8 g (namely, 0.215 mol) of tris-(2-chloroethyl)-amine hydrochloride were added. The mixture was heated at 130° C. for 8 hours, under stirring, and then cooled, and the excess sodium alcoholate was neutralized with a 10% strength aqueous solution of hydrochloric acid. The 3,6-dioxaheptan-1-ol was removed by distillation at 130° C. under a pressure of 20 mm Hg. The resulting mixture was filtered in order to remove the sodium chloride, and the product was then distilled. 83 g of tris-(3.6.9-trioxadecyl)-amine, which distilled at 189° C. under a pressure of 0.1 mm Hg, were thus obtained.
The other sequestering agents within the scope of the present invention are prepared in similar manner.
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims. | Benzenoid ethers/thioethers are prepared by reacting an activated halobenzene with an anionic reactant, RA - M + , in the presence of at least one tertiary amine sequestering agent having formula:
N--CHR.sub.1 --CHR.sub.2 --O--CHR.sub.3 --CHR.sub.4 --O--.sub.n R.sub.5
] 3 | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to arachidonic acid or prostaglandin derivatives and to a process for preparing them. More particularly the invention relates to novel prostacyclin derivatives, in particular PGI 2 derivatives. More particularly, this invention relates to PGI 2 derivatives of formula I, Chart A which discloses a 5-fluoro 3-oxa prostacyclin with optionally substituted Ω-chain analogs.
2. Description of Prior Art
The prostaglandins and analogs are well-known organic compounds derived from prostanoic acid which has the structure and atom numbering shown in FIG. II Chart A.
As drawn hereinafter the formulas represent a particular optically active isomer having the same absolute configuration as PGI 2 .
In the formulas, broken line attachments to the cyclopentane ring or side chain indicate substituents in alpha configuration, i.e. below the plane of the cyclopentyl ring or side chain. Heavy solid line attachments indicate substituents in beta configuration, i.e. above the plane.
For background on prostaglandins, see for example Bergstrom et al., Pharmacol. Rev. 20, 1 (1968). For related compounds see Pace-Asciak et al., Biochem. 10 3657 (1971). Related compounds are described in a publication on 6-keto-prostaglandin F 1 α by Pace-Asciak, J. Am. Chem. Soc. 2348 (1976) and a publication on "PGX" (6,9α-oxido-9α, 15α-dihydroxyprosta(Z)5,(E)13-dienoic acid) by E. J. Corey et al., J. Am. Chem. Soc. 99, 20016 (1977).
The potential pharmaceutical value of prostacyclins and prostacyclin analogs is described by S. Moncada. Br. J. Pharmac. (1982), 76, 003-031 and by Honn et al. (U.K.) Biochemical Pharmacology (1983) 32 No. 1 1-11.
The compounds of this invention may be regarded as analogs of prostacyclin and prostacyclin type compounds.
Prostacyclin, an organic compound related to prostaglandins, is (5Z)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 and is represented by formula III of Chart A. For its synthesis and structure see for example R. A. Johnson et al., J. Am. Chem. Soc. 99, 4182 (1977) and Prostaglandins 12, 915 (1976), and E. J. Corey et al., cited above. For some of its biological properties uses see the references cited in the Johnson references. Prostacyclin is referred to as "PGI 2 , see Anonymous Prostaglandins 13, 375 (1977).
Prostaglandins and prostacyclin-type compounds, including derivatives and analogs, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. A few of these biological responses are: inhibition of blood platelet aggregation, stimulation of smooth muscle, inhibition of gastric secretion, inhibition of tumor cell metastasis, and reduction of undesirable gastrointestinal effects from systemic administration of prostaglandin synthetase inhibitors.
Because of these biological responses, prostaglandins and prostacyclin-type compounds are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
Prostacyclin and prostacyclin-type compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi or tumor cell metastasis in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent postoperative surgery, and to treat conditions such as atherosclerosis, hypertension, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. Other in vivo applications include geriatric patients to prevent cerebral ischemic attacks and long term prophylaxis following myocardial infarcts and strokes. For these purposes, these compounds are administered systemically, e.g., intravenously, subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situations, the intravenous route of administration is preferred. Doses in the range about 0.01 to about 10 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The addition of prostacyclin and prostacyclin-type compounds to whole blood provides in vitro applications such as storage of whole blood to be used in heart lung machines. Additionally, whole blood containing these compounds can be circulated through limbs and organs, e.g. heart and kidneys, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to a new body. Blocking of aggregated platelets is avoided by the presence of these compounds. For this purpose, the compound is added gradually or in single or multiple portions to the circulating blood, to the blood of the donor person or animal, to the perfused body portion, attached or detached, to the perfused body portion, attached or detached, to the recipient, or to two or all of those at a whole blood. These compounds are also useful in preparing platelet-rich concentrates from blood for use in treating thrombocytopenia or in chemotherapy.
Prostglandins E, F and related compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, they are useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent atonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the later purpose, the compound is administered by intraveous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal.
Prostaglandins and prostacyclin-type compounds are also useful in mammals, including man and certain useful animals, e.g. dogs and pigs, to reduce and control excessive gastric secretion, thereby reduce or avoid gastrointestinal ulcer formation, and accelerate the healing of such ulcers already present in the gastrointestinal tract. For this purpose, these compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. per kg. of body weight per minute, or in a total daily dose by injection of infusion in the range about 0.01 to about 10 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
Prostaglandins and prostacyclin-type compounds and ther analogs are also useful in mammals, including man, to treat primary neoplasms and other cancers or tumors by inhibiting the production of metastasis away from the primary lesion. These compounds can be used singularly or in combination with other anti-metastatic treatment such as chemotherapy and radiation therapy. See Honn et al., Biochemical Pharmacology, 32, 1-11, (1983) for mechanisms by which prostacyclins (PGI 2 ) are thought to prevent the metastasis by inhibiting the association of the released tumor cells with platelets and/or the blood vessel wall thereby inhibiting the formation of new metastatic foci away from the primary lesion.
To treat with an anti-metastatic amount of the prostaglandin or prostacyclin type compound, the compound is administered by infusion or injection, intravenously, subcutaneously or intramuscularly in an infusion dose range of about 0.001-50 mg/kg of body weight per minute, or in a total daily dose by injection in the range of about 0.01 to 10 mg/kg of body weight per day, the exact dose depending upon the age, weight and condition of the patient or animal, and on the frequency and route of administration.
Prostaglandins and prostacyclin-type compounds are also useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors, and are used for that purpose by concomitant administration of prostaglandins or prostacyclin-type compound and anti-inflammatory prostaglandin synthetase inhibitor. See Partridge et al., U.S. Pat. No. 3,781,429, for a disclosure that the ulcerogenic effect induced by certain non-steroidal and steroidal anti-inflammatory agents in rats is inhibited by concomitant oral administration of certain prostaglandins of the E and A series, including PGE 1 , PGE 2 , PGE 3 , 13, 14-dihydro-PGE 1 , and the corresponding 11-deoxy-PGE and PGA compounds. Prostaglandins and prostacyclin-type compounds are useful, for example, in reducing the undesirable gastrointestinal effects resulting from systemic administration of indomethacin, phenylbutazone, and aspirin. These are substances specifically mentioned in Partridge et al., as non-steroidal, anti-inflammatory agents. These are also known to be prostaglandin synthetase inhibitors.
The anti-inflammatory synthetase inhibitor, for example and indomethacin, aspirin, or phenylbutazone, is administered in any of the ways known in the art to alleviate an inflammatory condition, for example, in any dosage regimen and by any of the known routes of systemic administration.
The prostaglandins or prostacyclin-type compound is administered along with the anti-inflammatory prostaglandin synthetase inhibitor either by the same route of administration or by a different route. For example, if the anti-inflammatory substance is being administered orally, the prostaglandins or prostacyclin-type compound is also administered orally, or alternatively, as administered rectally in the form of a suppository or, in the case of women, vaginally in the form of a suppository or a vaginal device for slow release, for example as described in U.S. Pat. No. 3,545,439. Alternatively, if the anti-inflammatory substance is being administered rectally, the prostaglandin or prostacyclin-type compound is also administered rectally. Further, the prostaglandin or protacyclin derivative can be conveniently administered orally or, in the case of women, vaginally. It is especially convenient when the administration rate is to be the same for both anti-inflammatory substance and prostaglandin or prostacyclin-type compound to combine both into a single dosage form.
The dosage regimen for the prostaglandin or prostacyclin-type compound in accord with this treatment will depend upon a variety of factors, including the type, age, weight, sex and medical condition of the mammal, the nature and dosage regimen of anti-inflammatory synthetase inhibitor being administered to the mammal, the sensitivity of the particular prostaglandin or prostacyclin-type compound to be administered. For example, not every human in need of an anti-inflammatory substance experiences the same adverse gastrointestinal effects when taking the substance. The gastrointestinal effects will frequently vary substantially in kind and degree. But it is within the skill of the attending physician or veterinarian to determine that administration of anti-inflammatory substance is causing undesirable gastrointestinal effects in the human or animal subject and to prescribe an effective amount of the prostaglandin or prostacyclin-type compound to reduce and then substantially to eliminate those undesirable effects.
Prostaglandin or prostacyclin-type compounds are also useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, bronchiectasis, pneumonia and emphysema. For these purposes, these compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsules, or liquids; rectally in the form of suppositories; parenterally, subcutaneously, or intramuscularly, with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use the prostaglandin or prostacyclin-type compound can be combined advantageously with other asthmatic agents, such as sympathomimetics (isoproterenol, phyenylphedrine, ephedrine, etc.); xanthine derivatives (theophylline and aminophylline); and corticosteroids (ACTH and prednisolone).
Prostaglandin or prostacyclin-type compounds are effectively administered to human asthma patients by oral inhalation or aerosol inhalation.
For administration by the oral inhalation route with conventional nebulizers or by oxygen aerosolization it is convenient to provide the prostacyclin ingredient in dilute solution, preferably at concentrations of about 1 part of medicament to form about 100 to 200 parts by weight of total solution. Entirely conventional additives may be employed to stabilize these solutions or to provide isotonic media, for example, sodium chloride, sodium citrate, citric acid, and the like can be employed.
For administration as a self-propelled dosage unit for administering the active ingredient in aerosol form suitable for inhalation therapy the composition can comprise the above ingredient suspended in an inert propellant (such as a mixture of dichloro-difluoromethane and dichloro-tetrafluoroethane) together with a co-solvent, such as ethanol, flavoring materials and stabilizers. Instead of a co-solvent there can be used a dispensing agent such as oleyl alcohol. Suitable means to employ the aerosol inhalation therapy technique are described fully in U.S. Pat. No. 2,868,691 for example.
Prostaglandins or prostacyclin-type compounds are useful in mammals, including man, as nasal decongestants and are used for this purpose in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
Prostacyclin or prostacyclin-type compounds are also useful in treating peripheral vascular disease in humans. The term peripheral vascular disease as used herein means disease of any of the blood vessels outside of the heart, the microvasculature serving the heart and to disease of the lymph vessels, for example, frostbite, ischemic cerebrovascular disease, arteriovenous fistulas, ischemic leg ulcers, phlebitis, venous insufficiency, gangrene, hepatorenal syndrome, ductus arteriosus, nonobstructive mesenteric ischemia, artritis lymphangitis and the like. These examples are included to be illustrative and should not be construed as limiting the term peripheral vascular disease. For these conditions the prostacyclin compounds are administered orally or parentally via injection or infusion directly into a vein or artery.
The dosages of such compounds are in the range of 0.01-10 μg. administered by infusions at an hourly rate or by injection on a daily basis, i.e. 1-4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. Treatment is continued for one to five days, although three days is ordinarily sufficient to assure long-lasting therapeutic action. In the event that systemic or side effects are observed the dosage is lowered below the threshold at which such systemic or side effects are observed.
Prostacyclin or prostacyclin-type compounds are accordingly useful for treating peripheral vascular diseases in the extremities of humans who have circulatory insufficiencies in said extremities, such treatment affording relief of rest pain and induction of healing of ulcers.
For a complete discussion of the nature of and clinical manifestations of human peripheral vascular disease and the method previously known of its treatment with prostaglandins see South African Pat. No. 74/0149 referenced as Derwent Farmdoc No. 58,400V. See Elliott et al., Lancet Jan. 18, 1975, pp. 140-142. Prostaglandins or prostacyclin-type compounds are useful in place of oxytocin to induce labor in pregnant female animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the compound is infused intravenously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 to 60 hours after the membranes have ruptured and natural labor has not yet started. An alternative route of administration is oral.
Prostaglandins or prostacyclin type compounds are further useful for controlling the reproductive cycle in menstruating female mammals, including humans. By the term menstruating female mammals is meant animals which are mature enough to menstruate, but not so old that regular menstruation has ceased. For that purpose the prostaglandin compound is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine routes are alternate methods of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first or second trimester of the normal mammalian gestation period.
Prostaglandin or prostacyclin-type compounds are further useful in causing cervical dilation in pregnant and nonpregnant female mammals for purposes of gynecology and obstetrics. In labor induction and in clinical abortion produced by these compounds, cervical dilation is also observed. In cases of infertility, cervical dilation produced by these compounds is useful in assisting sperm movement to the uterus. Cervical dilation by prostaglandin compounds is also useful in operative gynecology such as D and C (Cervical Dilation and Uterine Curettage) where mechanical dilation may cause perforation of the uterus, cervical tears, or infections. It is also useful for diagnostic procedures where dilation is necessary for tissue examination. For these purposes, the prostacyclin compound is administered locally or systemically.
The prostaglandin compound, for example, is administered orally or vaginally at doses of about 5 to 50 mg. per treatment of an adult female human, with from one to five treatments per 24 hour period. Alternatively the compound is administered intramuscularly or subcutaneously at doses of about one to 25 mg. per treatment. The exact dosages for these purposes depend on the age, weight, and condition of the patient or animal.
Prostaglandins and prostacyclin-type compounds are further useful in domestic animals as in abortifacients (especially for feedlot heifer), as an aid to estrus detection, and for regulation or synchronization of estrus. Domestic animals include horses, cattle, sheep, and swine. The regulation or synchronization of estrus allows for more efficient management of both conception and labor by enabling the herdsman to breed all his females in short pre-defined intervals. This synchronization results in a higher percentage of live births than the percentage achieved by natural control. The prostaglandin or prostacyclin-type compound is injected or applied in a feed at doses of 0.1-100 mg. per animal and may be combined with other agents such as steroids. For example, mares are given the prostaglandin compound 5 to 8 days after ovulation and return to estrus. Cattle are treated at regular intervals over a 3 week period to advantageously bring all into estrus at the same time.
Prostaglandin or prostacyclin-type compounds increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, these compounds are useful in managing cases of renal dysfunction, especially those involving blockage of a renal vascular bed. Illustratively, these compounds are useful to alleviate and correct cases of edema resulting, for example, from massive surface burns, and in the management of shock. For these purposes, these compounds are preferably first administered by intravenous injection at a dose in the range 10 to 1000 μg. per kg. of body weight or per kg. of body weight per minute until the desire effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. kg. of body weight per day.
Prostaglandin or prostacyclin-type compounds are useful for treating proliferating skin diseases of man and domesticated animals, including psoriasis, atopic dermatitis, non-specific dermatitis, primary irritant contact dermatitis, allergic contact dermatitis, basal and squamous cell carcinomas of the skin, lamellar ichthyosis, epidermolytic hyperkeratosia, premalignant sun-induced keratosis, nonmalignant keratosis, acne, and seborrheic dermatitis in humans and atopic dermatitis and mange in domesticated animals. These compounds alleviate the symptoms of these proliferative skin disease: psoriasis, for example, being alleviated when a scale-free psoriasis lesion is noticeably decreased in thickness or noticeably but incompletely cleared or completely cleared.
For those purposes, such compounds are applied topically as compositions including a suitable pharmaceutical carrier, for example as an ointment, lotion, paste, jelly, spray, or aerosol, using topical bases such as petrolatum, lanolin, polyethylene glycols, and alcohols. These compounds, as the active ingredients, constitute from about 0.1% to about 15% by weight of the composition, preferably from about 0.5% to about 2%. In addition to topical administration, injection may be employed, as intradermally, intra- or perilesionally, or subcutaneously, using appropriate sterile saline compositions.
Prostaglandin or prostacyclin-type compounds are useful as antiflammatory agents for inhibiting chronic inflammation in mammals including the swelling and other unpleasant effects thereof using methods of treatment and dosages generally in accord with U.S. Pat. No. 3,885,041, which patent in incorporated herein by reference.
Antiplatelet substances such as PGI 2 are known and have been used to afford relief from the aggregate condition.
PGI 2 , is a notably unstable substance. Although effective, PGI 2 often affords unwanted hypotensive effects. However, there may be occasions when such a hypotensive effect is desirable, such as in the treatment of hypertension. Also the antiplatelet aggregation effect is short lived (and the hazardous condition associated with uncontrolled platelet aggregation returns quickly). The stability of PGI 2 as a medicine is not satisfactory because the half period of its activity at physiological pH is only about several minutes. The instability of PGI 2 is considered to be due to the fact that chemically the vinyl ether structure containing a double bond at Δ 5 is readily hydrated to 6-oxoprostaglandin and in vivo, it is rapidly metabolized by a 15-position dehydrogenase. On the other hand, PGI 2 is considered to be not entirely satisfactory in its pharmacological actions because its doses required for platelet aggregation inhibiting action and antihypertensive action are almost equal to each other and its selectivity of action as a medicine is inferior. Accordingly, a great deal of efforts have been made in the art to synthesize many kinds of PGI 2 and remedy the aforesaid defects of PGI 2 (see, for example, S. M. Roberts, Chemistry, Biochemistry & Pharamcological Activity of Prostanoids, Pergamon Press, Oxford, 1979. New Synthetic Routes to Prostaglandins and Thromboxanes, Eds. S. M. Roberts and F. Scheinmann, Academic Press, 1982).
Additional examples of stabilized PGI 2 structures can be found in European patent application No. 0054795A2 at page 2 which is herein incorporated by reference.
PGI derivatives and prostacyclin derivatives are well known in the art as described above. U.S. Pat. Nos. 4,123,444 and 4,124,599 described PG derivatives namely prostacyclins. These patents describe 5 and 6 keto substituents as well as 9-deoxy-9-deoxo-9-hydroxymethyl substituents. The patents are described as having general prostaglandin activity. U.S. Pat. No. 4,145,535 relates to certain trans-4,5-didehydro-PGI compounds which are also stated to exhibit general prostacyclin like properties. U.S. Pat. No. 4,233,121 describes certain 5 halo-6,9, oxido prostaglandin derivatives which have anticoagulant activity. European patent application No. 0054795A2/1982 discloses novel 5 or 7 monohalogenated or 5,7 dihalogenated prostacyclins useful for controlling vascular actions and inhibiting tumor matastasis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1--Structure I discloses the numbering system of the 5-fluoro-3-oxa-prostacyclin compounds of this invention. Structure II discloses the numbering system of the prostane skeleton.
FIG. 2--Illustrates the general reaction scheme for the synthesis of the 5-fluoro-3-oxa-prostacyclins.
SUMMARY OF THE INVENTION
The present invention particularly provides:
1. A compound of formula I ##STR2## wherein R 1 is: (a) Na, K, or 1/2 Ca, or other pharmaceutically acceptable cation
(b) NR 3 2 , where R 3 ═H, methyl, ethyl, isopropyl or a combination of these groups;
(c) Alkyl of 1 to 6 carbon atoms, either branched or straight chain
(d) Hydrogen
wherein R 2 is:
(a) A 1-8 alkyl optionally containing 1 or 2 unsaturated bond(s) and optionally substituted by methyl, dimethyl or F;
(b) A carbocyclic compound of 4-7 carbons having optionally 1 unsaturated bond and having optionally 1 carbon replaced by S or O;
(c) Phenyl;
(d) Benzyl;
(e) --(CH 2 ) m --R 4 wherein m is 1-6 and R 4 is alkoxy or cycloalkyl;
wherein OH on carbon 15 is optionally on carbon 16; wherein X is, OCH 3 or OC 2 H 5 when neither C 5 -C 6 or C 6 -C 7 is a double bond and nothing if C 5 -C 6 or C 6 -C 7 is a double bond;
wherein the hydroxyl on carbon 15 is in either the R or S configuration.
In the compound of formula I, the R 1 may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl and the like, pentyl, isopentyl and the like, or hexyl, isohexyl and the like. R 3 may be methyl, ethyl, propyl or isopropyl. R 2 may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl and the like; pentyl, isopentyl and the like; hexyl, isohexyl and the like, heptyl, isoheptyl and the like octyl, isooctyl and the like.
R 2 may be ethylene, propylene, 1-butene, 2-butene, 1-pentene, 2-pentene, 3-pentene, 1-hexene, 2 hexene and the like; 1-heptene, 2-heptene and the like; 1-octene, 2-octene and the like. R 2 alkenes may be in either the cis or trans configuration. R 2 may be 2-8 alkyne optionally substituted by methyl, dimethyl or fluoro. Among the alkynes are acetylene, propyne, 1-butyne and the like, 1-pentyne and the like, 1-hexyne and the like, 1-heptyne and the like, and 1 octyne and the like.
R 2 may be a 2-8 alkyl such as pentyl or hexyl optionally substituted by methyl, dimethyl or fluoro. R 2 may be a carbocyclic compound of 4-7 carbons having optionally 1 unsaturated bond and optionally 1 carbon replaced by sulfur or oxygen. Such as cyclohexyl, cyclopentyl, cyclobutyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothienyl, tetrahydrothiopyranyl and the like. R 2 may also be phenyl or benzyl.
R 2 may be an alkyl containing 1-6 carbons with an alkoxy or cycloalkyl at the terminal carbon. The hydroxy at carbon 15 on R 2 may optionally be on carbon 16 and may be either hydroxyl in the R or S configuration. X may be hydrogen, methoxy or ethoxy when neither C 5 -C 6 or C 6 -C 7 is a double bond.
The compounds of the instant invention are novel in that, compared to natural occurring PGI 2 , they are surprisingly more stable and are active against platelet aggregation over a longer period of time. In addition, the compounds of the present invention show a surprising and unexpected increase in "anti-platelet potency."
The instability of PGI 2 is largely due to the chemical readiness to decompose via the opening of an enolic cyclic ether under neutral or acidic conditions. The hydrolysed compound is either inactive or shows a marked decrease in activity. The compounds of the instant invention are more stable because of the placement of an oxygen atom at the 3 position, a fluorine bound to the 5 position and optionally an Ω-chain which retards the 15-dehydrogenase activity either sterically or electronically.
The stereochemistry of hydroxyl at carbon 15 can be in either the R or the S configuration.
By virtue of this anti-platelet aggregation activity the compounds of formula I are useful in treating platelet dysfunction in human and animals. A physician or veterinarian of ordinary skills could readily determine a subject who is exhibiting platelet dysfunction symptoms. Regardless of the route of administration selected, the compounds of the present invention are formulated into pharmaceutically acceptable dosage forms by conventional methods known to the pharmaceutical arts.
The compounds can be administered in such oral unit dosage forms such as tablets, capsules, pills, powders, or granules. They also may be administered rectally, vaginally in such forms as suppositories or creams; they may also be introduced in the form of eye drops, interparenterally, subcutaneously, or intramuscularly, using forms known to the pharmaceutical art. In general, the preferred form of administration is orally.
An effective but non-toxic quantity of the compound is employed in treatment. The dosage regimen for preventing or treating platelet dysfunction by the compounds of this invention is selected in accordance with a variety of factors including the type, age, weight, sex, and medical condition of the mammal, the severity of the symptoms, the route of administration and the particular compound employed. An ordinarily skilled physician or veterinarian will readily determine and prescribe the effective amount of the agent to prevent or arrest the progress of the condition. In so proceeding, the physician or veterinarian could employ relatively low dosages at first, subsequently increasing the dose until a maximum response is obtained.
The acidic compounds of this invention can also be administered as pharmacologically acceptable basic salts such as sodium, potassium and calcium.
The starting materials used for the synthesis of the novel 3-oxa 5-fluoro prostacyclin analogs are the corresponding 3-oxaprostacyclins (Upjohn U.S. Pat. No. 3,923,861 (1975)). For example, 3-oxaPGI 2 tert-butylester is reacted with gaseous perchloryl fluoride in a protic solvent such as methanol. The resultant 5-fluoro-6-methoxy analog formula (II) is silylated with a trialkylsilyl chloride such as tert-butyldimethylsilyl chloride in a solvent such as anhydrous DMF containing a base such as imidazole. The resulting bis-silyl ethers (mixture of diastereo isomers or separate isomers) (III) are then converted to a mixture of the Δ 5 fluoro compound (V) and the Δ 6 ,7 -5-fluoro compound (IV) via thermal elimination of methanol in a high boiling solvent such as refluxing tert-butyl benzene. The resulting mixture of compounds may be deprotected through exposure to a solution of an active floride source such as tetra n-butyl ammonium fluoride in a solvent such as anhydrous tetrahydrofuran. The mixture of fluoro-prostacyclins (VI) and (VII) may then be separated chromatographically.
These compounds have been shown to have platelet disaggregatory potency greater than that exhibited by the Δ 6 ,7 fluoro compounds previously cited in the literature.
SYNTHESIS OF 16 HYDROXY PROSTACYCLINS
The synthesis of 16-hydroxy prostacyclins is achieved via the corresponding PGF2α analogs (as described for the natural 15-hydroxy prostacyclins).
The 16-hydroxy PGF2α analogs are synthesized via the scheme illustrated in the figure below. This synthetic procedure is described by P. W. Collins, E. Z. Dajani, R. Pappo, A. F. Gasiecki, R. G. Bianchi and E. M. Woods, J. Med. Chem. 26 786 (1983) herein incorporated by reference. ##STR3##
In addition to the compounds described in the examples, it is also possible, for example, to manufacture according to the invention the compound given in FIG. 1, general formula I in which the hydroxyl on carbon 15 is in the R or S configuration and the OH on carbon 15 is optionally on carbon 16.
BIOLOGICAL TESTING
Inhibition of ADP-Induced platelet aggregation, in vitro
Aggregation was determined using a Payton Dual Channel Aggregation Module. A Riker-Denshi recorder was used for recording the aggregation curves.
Citrated whole rat blood (1 part 3.8% sodium citrate and 9 parts blood) was centrifuged to obtain platelet rich plasma.
The addition of ADP to platelet-rich plasma induces platelet aggregation. A compound was rated active if, after three separate incubations with platelet-rich plasma at 10 -4 M the mean ADP-induced response is reduced by 50% or more.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example 1
1,1-Dimethylethyl(3aβ,6αβ)[2-fluoro-2-[hexahydro-5α-hydroxy-4β-(3S*-hydroxy-1E-octenyl)-2R,2α-methoxy-2H-cyclopenta[b]furanyl]ethoxy]acetate and its methoxy epimer.
1,1-Dimethylethyl(3aS,3aα,6aα)[2-[hexahydro-5β-hydroxy-4.alpha.-(3S*-hydroxy-1E-octenyl)-2H-cyclopenta-[b]furan-2Z-ylidene]ethoxy]acetate (0.15 g) was dissolved in anhydrous methanol (3 cm 3 ) containing powdered sodium carbonate (0.3 g). The mixture was stirred vigorously at 0° C. whilst a stream of perchloryl fluoride (2-3 equivalents) was bubbled slowly through the mixture [Perchloryl fluoride had previously been condensed into a graduated burette (-78° C.)]. The mixture was allowed to warm to room temperature, stirred for 30 minutes and then partitioned between ether and water. The organic layer was separated, washed with saturated sodium chloride solution and dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo afforded 0.1 g of crude product which was chromatographed on silica gel (Merck 60, CH 2 Cl 2 /5% CH 3 OH). Thus obtained was 0.06 g of a mixture of the diastereoisometric fluoro-prostanoids.
Spectral Data
NMR (1H, δ, CDCl 3 , 200 MHz) 1.45 (9H s, t-Bu) 3.17-3.28 (3H, 4s, OCH 3 s) 3.9 (2H, s, CH 2 CO 2 tBu) 5.3-5.55 (2H, m, olefinics) NO 4.57 (1H, m, H C═C O --) M.S(Isobutane CI) m /eBis-TMS ether 573 (M + --CH 3 OH)
IR (CHCl 3 ) no v 1690 cm -1
The following is the chemical structure of the compound of Example 1. ##STR4##
EXAMPLE 2
1,1-Dimethylethyl(3aβ,6αβ)[2-fluoro-2-[hexahydro-5α-[[dimethylethyl)dimethylsilyl]oxy]-4β-(3S*-[[dimethylethyl)dimethylsilyl]oxy]-1E-octenyl)-2R,2α-methoxy-2H-cyclopenta-[b]furanyl]ethoxy]acetate
The mixture of methoxyfluoro PGI, derivatives (II) (0.06 g) was dissolved in anhydrous dimethyl formamide (0.5 cm 3 ) containing tert-butyldimethylsilyl chloride (2.4 equivalents) and imidazole (5.0 equivalents). The mixture was stirred magnetically under nitrogen for 10 hours and then poured into water. The aqueous mixture was thoroughly extracted with diethyl ether and the organic layers combined, washed sequentially with water and brine and then dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo afforded a crude residue which was purified by chromatography on silica gel (Merck 60 hexane/EtOAc, 90:10) to afford 0.07 g of pure bis silyl ethers.
The following is the chemical structure of the compound of Example 2. ##STR5##
EXAMPLE 3
1,1-Dimethylethyl[2-fluoro-2-[4,5,6aα-tetrahydro-5β-[[dimethylethyl)dimethylsilyl]oxy]-4α[3S*-[[(dimethylethyl)dimethylsilyl]oxy]-1E-octenyl]3aS,3aαH-cyclopenta[b]furanyl]ethoxy]acetate and 1,1-dimethylethyl(3aS,3aα,6aα[2-fluoro-2-[hexahydro-5β-[(dimethylethyl)dimethylsilyl]oxy-4α-[3S*-[[(dimethylethyl)dimethylsilyl]oxy]-1E-octenyl-2H-cyclopenta[b]furan-2E-ylidene[ethoxy]acetate.
The silyl esters (III) (35 mgs) were dissolved in anhydrous tert-butyl benzene (0.5 cm 3 ) and added via syringe to tert-butyl benzene at reflux temperature. The solution was maintained at this temperature for 40 minutes and then cooled. The reaction mixture was applied directly to a florisil column (packed in hexane/0.2% triethylamine). Eluted from this column was 10 mgs of a mixture of fluoro olefins (IV) and (V) followed by 17 mgs of starting material.
Spectral Data
NMR (1H, δ, CDCl 3 , 100 MHz) 0.1 (12H brs, Si(CH 3 ) 2 ), 0.9 (18H, 2s, Si-t-Bu) 1.48 (9H, s, CO 2 t-Bu)) 4.0 (2H, s, CH 2 CO 2 t-Bu) 4.7-5.55 (m, olefinic H's) for mixture.
The following is the chemical structure of the compounds of Example 3. ##STR6##
EXAMPLE 4
1,1-Dimethylethyl(3aS,3aα,6aα)[2-fluoro-2-[4,5,6,6aα-tetrahydro-5β-hydroxy-4α-(3S*-hydroxy-1E-octenyl)-3aS,3aαH,-cyclopenta-[b]furanyl]ethoxy]acetate and 1,1-Dimethylethyl-(3aS,3aα,6aα)[2-fluoro-2-[hexahydro-5β-hydroxy-4α(3S*-hydroxy-1E-octenyl)-2H-cyclopenta[b]furan-2E-ylidene]ethoxy]acetate
A mixture of fluoro-olefins (IV) and (V) (100 mgs) were dissolved in anhydrous tetrahydrofuran (0.5 cm 3 ) containing triethylamine (1 drop) and tetra n-butylammonium fluoride (7 equivalents) and stirred overnight at RT under N 2 . The reaction mixture was partitioned between ethyl acetate/ether and water and the organic layer separated, washed with saturated sodium chloride solution and dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo afforded a crude residue which was purified by column chromatography to afford 1.5 mgs of exo-olefin VII and 50 mgs of endo-olefin (VI).
The following is the chemical structure of the compounds of Example 4. ##STR7##
EXAMPLE 5
The synthesis of lower chain (Ω) modified fluoro-prostacyclins was achieved via the corresponding 3-oxa prostacyclin. The 3-oxa prostacyclins were obtained via literature procedures, see for example, Prostaglandin synthesis, J. S. Bindra and R. Bindra, Academic Press (1977).
The starting material was the known aldehyde ##STR8## and this could be reacted in Wadsworth-Emmons fashion with a β-ketophosphonate anion such as ##STR9## wherein R 2 is: (a) A 1-8 alkyl optionally containing 1 or 2 unsaturated bond(s) and optionally substituted by methyl, dimethyl or F;
(b) A carbocyclic compound of 4-7 carbons having optionally 1 unsaturated bond and having optionally 1 carbon replaced by S or O;
(c) Phenyl;
(d) Benzyl;
(e) --(CH 2 ) m --R 4 wherein m is 0-6 and R 4 is alkoxy or cycloalkyl;
The desired β-ketophosphonate was made via the reaction of the lithium salt of methyl (dimethyl) phosphonate with the appropriate ester. ##STR10##
EXAMPLE 6
The Inhibition of ADP-Induced Platelet Aggregation
The procedure for testing platelet anti-aggregatory activity in vitro is the one described by E. R. Waskawic (Searle BRR 7710007). Aggregation was determined with a Payton Dual Channel Aggregation module. A Riken-Denshi recorder was used for recording the aggregation curves.
Citrated whole blood (1 part 3.8% sodium citrate and 9 parts blood) was centrifuged to obtain platelet rich plasma (PRP) (700 RPM for 11 mins.) in an IE centrifuge (Model PR 6000). After the PRP fraction was removed, the remainder was spun at 900×g for 15 mins. to obtain platelet poor plasma (PPP) (1800 RPM in IEC PR 6000). The number of platelets per ml PRP is determined by counting a 5 μl aliquot of PRP in a Coutter ZBI counter and channelyzer Model C-1000.
PRP is diluted with PPP 1:2 to obtain a count of approx. 25000 on the screen or 10 9 platelets/ml PRP to evaluate the anti-aggregating agent. The module was standardized with an aliquot of PPP and that of diluted PRP.
The aggregating agent used is ADP prepared as follows:
4.7 mgs ADP (MW 427) in 10 ml saline yields a 10 μM stock solution administered in 4 μl into 400 μL PRP, of ADP disodium (MW=473).
______________________________________Vol. of stock (ml) Volume of saline (ml) [f] cuvette (μM)______________________________________1.6 0.4 81.2 0.8 60.8 1.2 40.4 1.6 20.2 1.8 1______________________________________ [f] = final concentration
Prostacyclin is used as the standard of antiaggregatory activity for determining the potency of compounds tested. A 10 2 M solution (to give a starting concentration of 10 -4 M when 4 μL is added to 400 μL PRP) is diluted serially to obtain solutions with final concentrations of 10 -6 , 10 -7 , 10 -8 , 10 -9 M.
Compounds to be screened are dissolved in absolute ethanol, saline or water to achieve a 10 -2 M solution if 4 μL added to PRP giving a [f] in the cuvette equal to 10 -4 M. Serial dilutions in saline give 10 -5 , 10 -6 and 10 -7 M.
1. Determine the dose of ADP which on a standard curve would be on the linear portion and allow reversal of the aggregation curve.
2. Determine the PGI 2 standard curve of percentage inhibition of aggregation. Use saline in control cuvette to compare the extent of inhibition by PGI 2 as represented by the depth of the aggregation curve. Allow the PRP to preincubate for approximately one minute prior to the addition of prostacyclin and another minute with PGI 2 prior to the addition of ADP. ##EQU1##
The % inhibition is plotted against prostacyclin dose on semilog paper. The IC 50 value is equal to the PGI 2 dose effecting 50% inhibition of the control response.
3. The test compound is added to PRP and preincubated for 1 minute prior to ADP administration. If the compound has an IC 50 lesser than 10 -4 M, it is considered to be active.
______________________________________ Results (IC.sub.50 (Molar))______________________________________Prostacyclin 6 × 10.sup.-93-oxa prostacyclin Tert-butyl ester 1 × 10.sup.-65-fluoro Δ.sup.6,7 prostacyclin 6 × 10.sup.-65-fluoro Δ.sup.6,7 3-oxa, prostacyclin 4 × 10.sup.-6tert-butyl ester______________________________________
EXAMPLE 7
Ethyl (3αβ,3αβ,6αβ)[2-fluoro-2-[hexahydro-2R, 2α-methoxy-4β-[(3S*-tetrahydro-2H-pyran-2-yl)-3-[(triethylsilyl)oxy]-1E-propenyl]-5α-[(triethylsilyl)oxy]-2H-cyclopenta[b]furanyl] ethoxy acetate.
Ethyl (3aS,3aα,6aα)[2-[hexahydro-4α-[(3S*-tetrahydro-2H-pyran-2-yl)-3-[(triethylsilyl)oxy]-1E-propenyl]-5β-[(triethylsilyl)oxy]-2H-cyclopenta[b]furan-2Z-ylidene]ethoxy]acetate (1 g) is dissolved in anhydrous methanol (20 cm 3 ) containing powdered sodium carbonate (2-5 equivalents). The mixture is stirred vigorously at 0° C. whilst a stream of perchloryl fluoride (2-3 equivalents) is bubbled slowly through the mixture. The mixture is allowed to warm to room temperature, stirred for 30 minutes and then partitioned between ether and water. The organic layer is separated, washed with saturated sodium chloride solution and dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo affords a crude product which is chromatographed on silica gel (Merck 60) to afford a mixture of diastereoisomeric fluoro-prostanoids.
The following is the chemical structure of the compound of Example 7. ##STR11##
EXAMPLE 8
Ethyl (3aβ,6aβ)[2-fluoro-2-[hexahydro-5α-hydroxy-4β[3S*-hydroxy-3-(tetrahydro-2H-pyran-2-yl)-IE-propenyl]-2R,2α-methoxy-2H-cyclopenta[b]furanyl ]ethoxy]acetate
The mixture of fluoro-prostanoids from the previous Example 7 (0.1 g) is treated with a catalytic amount of pyridinium p-toluenesulfonate in methanol. The mixture is stirred at room temperature for 5 hours and then evaporated in vacuo. The residue is passed thru a short silica column (EtOAc as eluant) to afford the title compound as an oil (0.05 g).
The following is the chemical structure of the compound of Example 8. ##STR12##
EXAMPLE 9
Ethyl (3aS,3aα,6aα)[2-fluoro-2-[hexahydro-4α-[(3S*-tetrahydro-2H-pyran-2-yl)-3-[(triethylsilyl)oxy]-1E-propenyl]-5β-[(triethylsilyl)oxy]-2H-cyclopenta[b]furan-2Z-ylidene]ethoxy] acetate and Ethyl [2-fluoro-2-[4,5,6,6aα-tetrahydro-4α-[(3S*-tetrahydro-2H-pyran-2-yl)-3-[(triethylsilyl)oxy]-1E-propenyl]-5β-[(triethylsilyl)oxy]-3aS,3aα H-cyclopenta [b]furanyl]ethoxy acetate
Ethyl (3aβ,6aβ)[2-fluoro-2-[hexahydro-2R,2α-methoxy-4β-[(3S*-tetrahydro-2H-pyran-2-yl)-3-[(triethylsilyl)oxy]-1E-propenyl]-5α[(triethylsilyl)oxy]-2H-cyclopenta [b]furanyl]ethoxy acetate (mixture of diastereoisomers) (0.4 g) is dissolved in anhydrous tert-butyl benzene and the mixture heated at reflux temperature for 1 hour. The cooled mixture is applied directly to a preconditioned florisil column. Repeated chromotography (hexane/ethyl acetate mixtures) affords the pure title compounds.
The following are the chemical structures of the compounds of Example 9. ##STR13##
EXAMPLE 10
Ethyl (3aS,3aα,6aα)[2-fluoro-2-[hexahydro-5β-hydroxy-4α-[3S*-hydroxy-3(tetrahydro-2H-pyran-2-yl)-1E-propenyl]-2H-cyclopenta[b]furan-2Z-ylidene]ethoxy] acetate and Ethyl [2-fluoro-2-[4,5,6,6aα-tetrahydro-5β-hydroxy-4α-[3S*-hydroxy-3-tetrahydro-2H-pyran-2-yl)-1E-propenyl]-3aS,3aαH-cyclopenta[b]furanyl]ethoxy] acetate.
Ethyl (3aS,3aα,6aα)[2-fluoro-2-[hexahydro-4α-[(3S*-tetrahydro-2H-pyran-2-yl)-3-[(triethylsilyl)oxy]-1E-propenyl]-5β-[(triethylsilyl)oxy]-2H-cyclopenta[b]furan-2Z-ylidene]ethoxy]acetate (10 mgs) is dissolved in anhydrous THF containing tetra n-butylammonium fluoride (5 equivalents) the mixture is stirred at room temperature under nitrogen for 5 hours and then partitioned between ethyl acetate and water. The organic layer is separated, dried (Na 2 SO 4 ) and evaporated in vacuo to afford the title compound as a crude oil which is purified by chromatography on florisil (hexane/EtoAc). The second title compound is prepared in the manner described for the first title compound. The following are the chemical structures of the compounds of Example 10. ##STR14##
EXAMPLE 11
[2-Fluoro-2-[4,5,66aα-tetrahydro-5β-hydroxy-4α-[3S*-hydroxy-3-(tetrahydro-2H-pyran-2-yl)-1E-propenyl]-3aS,3aαH-cyclopenta [b]furanyl]ethoxy] acetic acid, sodium salt.
Ethyl [2-fluoro-2-[4,5,6,6aα-tetrahydro-5β-hydroxy-4α-[3S*-hydroxy-3-tetrahydro-2H-pyran-2-yl)-1E-propenyl]-3aS,3aαH-cyclopenta[b]furanyl]ethoxy] acetate (22 mgs) is dissolved in a minimum of methanol containing 1.5 equivalents of aqueous sodium hydroxide. The mixture is stirred at 0° C. for 10 minutes and then 2 drops of water are added. The mixture is allowed to stir at room temperature for 48 hours and then evaporated under high vacuum. The residue was triturated with dry ether and redried to afford the amorphous sodium salt.
The following is the chemical structure of the compound of Example 11. ##STR15##
EXAMPLE 12
Methyl (3aβ,6aβ)[2-[4β-(3S*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5α-hydroxy-2R,2α-methoxy-2H-cyclopenta[b][furanyl]-2S*-fluoroethoxy]acetate
Methyl (3aS,3aα,6aα[2-[4α-(3S*-cyclopentyl-3-hydroxy-1E-propenyl]hexahydro-5β-hydroxy-B 2H-cyclopenta[b]furan-2Z-ylidene]-2ethoxy acetate (1 g) is dissolved in anhydrous methanol (20 cm 3 ) containing powdered sodium carbonate (2.5 equivalents). The mixture is stirred vigorously at 0° C. whilst a stream of perchloryl fluoride (2-3 equivalents) is bubbled slowly through the mixture. The mixture is allowed to warm to room temperature, stirred for 30 minutes and then positioned between ether and water. The organic layer is separated, washed with saturated sodium chloride solution and dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo affords the crude product which is chromatographed on silica gel to afford a mixture of diastereoisomeric fluoroprostanoids.
The following is the chemical structure of the compound of Example 12. ##STR16##
EXAMPLE 13
Methyl (3aβ,6aβ)[2-[4β-(3S*-cyclopentyl-3-[[dimethylethyl)dimethylsilyl]oxy]-1E-propenyl)hexahydro-5α-[[dimethylethyl)dimethylsilyl]oxy]-2R,2α-methoxy-2H-cyclopenta[b]furanyl]-2S*-fluoroethoxy]acetate
The title compound is obtained from its corresponding diol using the procedure described previously (tert-butyldimethylsilyl chloride/DMF/imidazole as a mixture of diastereoisomers.
The following is the claimed structure of the compound of Example 13. ##STR17##
EXAMPLE 14
Methyl (3aS,3aα,6aα)[2-[4α-(3S*-cyclopentyl-3-[[dimethylethyl)dimethylsilyl]oxy]-1E-propenyl)hexahydro-5β-[[dimethylethyl)dimethylsilyl]oxy]-2H-cyclopenta[b]furan-2Z-ylidene)-2-fluoroethoxy acetate and Methyl[2-[4α-(3S*-cyclopentyl-3-[[(dimethylethyl)dimethylsilyl]oxy]-1E-propenyl)-4,5,6,6aα-tetrahydro-5β-[[(dimethylethyl)dimethylsilyl]oxy]-3aS,3aαH-cyclopenta[b]furanyl]-2-fluoroethoxy]acetate
The title compounds are prepared from the diasteromeric methoxy-fluoro compounds mentioned in Example 13 by heating in refluxing tert-butyl benzene (as described previously).
The following are the chemical structure of the compounds of Example 14. ##STR18##
EXAMPLE 15
Methyl (3aS,3aα,6aα)[2-[4α-(3S*-cyclopentyl)-3-hydroxy-1E-propenyl]hexahydro-5β-hydroxy-2H-cyclopenta[b]furan-2Z-ylidene]-2-fluoroethoxy]acetate
Methyl (3aS,3aα,6aα)[2-[4α-3S*-cyclopentyl-3-[[dimethylethyl)dimethylsilyl]oxy]-1E-propenyl)hexahydro-5β-[[(dimethylethyl)dimethysilyl]oxy]-2H-cyclopenta[b]furan-2Z-ylidene)-2-fluoroethoxy]acetate is dissolved in anhydrous THF containing 5 equivalents of tetra n-butylammonium fluoride and 10 equivalents of triethylamine. The mixture is stirred at room temperature under nitrogen for 10 hours and then partitioned between ethyl acetate and water. The organic layer is separated, dried (Na 2 SO 4 ) and evaporated in vacuo. The residue is purified by chromatography on florisil (EtOAc) to afford the title compound.
The following is the chemical structure of the compound of Example 15. ##STR19##
EXAMPLE 16
(3aS,3aα,6aα)[2-[4α-(3S*-Cyclopentyl-3-hydroxy-1E-propenyl)]hexahydro-5β-hydroxy-2H-cyclopenta[b]furanyl-2Z-ylidene]-2-fluoroethoxy]acetic acid sodium salt
Methyl (3aS,3aα,6aα)[2-[4a-(3S*-cyclopentyl-3-hydroxy-1E-propenyl]hexahydro-5β-hydroxy-2H-cyclopenta[b]furan-2Z-ylidene]-2-fluoroethoxy]acetate is dissolved in methanol (0-5 cm 3 ) containing 1-5 equivalents of 1N NaOH at 0° C. The mixture is stirred under N 2 for 10 minutes and then 2 drops of water are added. The mixture is stirred at RT for 24 hours under a slow stream of nitrogen (to remove the methanol) and then evaporated under high vacuum to afford the title compound as an amorphous solid.
The following is the chemical structure of the compound of Example 16. ##STR20##
EXAMPLE 17
(3aS,3aα,6aα)[2-[4α-(3S*-cyclopentyl-3-hydroxy-1E-propenyl)]hexahydro-5β-hydroxy-2H-cyclopenta[b]furan-2Z-ylidene]-2-fluoroethoxy ]acetamide
This compound is prepared using the procedures outlined in the text starting with (3aβ,6aβ)[2-[4β-3S*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5α-hydroxy-2R,2α-methoxy-2H-cyclopenta[b]furanyl]-2S*-fluoroethoxy]acetic acid (0.1 g) which is dissolved in methanol ( 1 CM 3 ) in a pressure bottle and chilled to -60° C. under N 2 and liquid ammonia (1CM 3 ) added. The container is sealed and allowed to warm to room temperature. After 14 days the reaction bottle is opened, evacuated and product isolated as an amorphous solid.
The following is the chemical structure of the compound of Example 17. ##STR21##
EXAMPLE 18
Methyl (3aβ,6aβ)[2-fluoro-2-[hexahydro-5α-hydroxy-4β-(3S*-hydroxy-4-methyl-1E-octen-6-ynyl)-2R,2α-methoxy-2H-cyclopenta[b]furanyl]ethoxy]acetate
Methyl (3aS,3aα,6aα)[2-[hexahydro-5β-hydroxy-4α-(3S*-hydroxy-4-methyl-1E-octen-6-ynyl)-2H-cyclopenta[b]furan-2Z-ylidene]ethoxy]acetate (1.5 g) is dissolved in anhydrous methanol (25 cm 3 ) containing powdered potassium carbonate (2.5 equivalents). The mixture is stirred vigorously at 0° C. whilst a slow stream of ClO 3 F (2.5 equivalents) is bubbled thru the mixture. The mixture is allowed to warm to room temperature over a period of 30 minutes, it is stirred for a further 15 minutes and then it is partitioned between ether and water. The organic layer is separated, dried (Na 2 SO 4 ) and evaporated in vacuo to afford the crude product. The material is purified by chromatography on silica gel (Merck 60, EtOAc) to afford the title compounds.
The following is the chemical structure of the compound of Example 18. ##STR22## | The present invention describes 5-fluoro-3-oxa-prostacyclin (PGI 2 ) derivatives of Formula I. These compounds are useful for the treatment of platelet dysfunction, atherosclerosis, hypertension and tumor cell metastasis. Also disclosed is the process for preparing them and the appropriate intermediates. ##STR1## wherein R 1 is: (a) Na, K, or 1/2 Ca, or other pharmaceutically acceptable cation
(b) NR 3 2 , where R 3 ═H, methyl, ethyl, isopropyl or a combination of these groups;
(c) Alkyl of 1 to 6 carbon atoms, either branched or straight chain
(d) Hydrogen
wherein OH on carbon 15 is optionally on carbon 16; wherein X═H, OCH 3 or OC 2 H 5 when neither C 5 -C 6 or C 6 -C 7 is a double bond and nothing if C 5 -C 6 or C 6 -C 7 is a double bond;
wherein R 2 is:
(a) A 1-8 alkyl optionally containing 1 or 2 unsaturated bond(s) and optionally substituted by methyl, dimethyl or F;
(b) A carbocyclic compound of 4-7 carbons having optionally 1 unsaturated bond and having optionally 1 carbon replaced by S or O;
(c) Phenyl;
(d) Benzyl;
(e) --(CH 2 ) m --R 4 wherein m is 1-6 and R 4 is alkoxy or cycloalkyl;
wherein the hydroxyl on carbon 15 is in either the R or S configuration. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. patent application Ser. No. 12/840,486 filed Jul. 21, 2010 which claims priority from U.S. Provisional Patent Application Ser. No. 61/229,838, filed Jul. 30, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to the manufacture of light weight parts for assembly with other parts. Such parts are frequently used in airplanes and vehicles.
[0004] 2. Background Art
[0005] British Patent 686,428 issued in 1954 discloses riveting strips of steel sheet metal to elongated aluminum-magnesium alloy profiled bearers. Steel sheet metal is welded to the strips of steel sheet metal.
[0006] Mellis et al., U.S. Patent Application Publication No. 2007/0271793, published Nov. 29, 2007 discloses a suspension arm for use in a vehicle, in which a coupling for assembling the arm to other components of the vehicle is attached to a tubular member made of steel, aluminum or the like, using a cast-in-place technique, rather than conventional welding.
SUMMARY OF THE INVENTION
[0007] In the present invention, a light weight alloy part is molded in a mold containing at least one weldable metal insert, so that portions of portions of the alloy part lap portions of the insert to securely lock said weldable insert to the light weight alloy part. The resulting hybrid part is thus both light weight and weldable to other assemblies and sub-assemblies.
[0008] These and other objects, advantages and features of the invention will be more fully understood and appreciated by reference to the written specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective and relatively close-up view of a known steering column support bracket, with the bracket being stamped and MIG-welded to the tubular member of an instrument panel frame;
[0010] FIG. 2 is a perspective view of an embodiment of a hybrid assembly consisting of a steel instrument panel frame and steering column support bracket comprising a magnesium-casted part and a steel insert assembly;
[0011] FIG. 3 is a perspective view of the steering column support bracket illustrated in FIG. 2 ;
[0012] FIG. 4 is a perspective view of the steering column support bracket shown in FIG. 2 , and illustrating the location of the holes or forms within the steel stampings positioned below the magnesium line;
[0013] FIG. 5 is a perspective view showing the separate components of the steel inserts of the steel stampings of the steering column support bracket; and
[0014] FIG. 6 is a perspective and stand-alone view of the magnesium-casted component of the steering column support bracket.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The principles of a preferred embodiment are disclosed, by way of example, in a vehicle part 200 as described herein and illustrated in FIGS. 2-6 . The vehicle part 200 includes components comprised of steel and of magnesium, with the use of magnesium facilitating a relative reduction in weight. The structure of the vehicle part 200 and preferred processes for manufacturing the vehicle part 200 permit the use of welding processes, although magnesium components are known to be essentially unweldable to other parts.
[0016] FIG. 1 illustrates a known vehicle part 100 . The known vehicle part 100 can be characterized as an instrument panel reinforcement frame with a steering column support bracket. More specifically, the vehicle part 100 includes an instrument panel reinforcement frame or main frame 102 having a configuration as shown in part in FIG. 1 . A greater portion of the main frame 102 is illustrated in FIG. 2 as frame 202 , which incorporates the preferred embodiment and will be described in subsequent paragraphs herein. The main frame 102 includes a tubular member 104 which extends across the entirety of the upper portion of the main frame 102 .
[0017] Secured to the tubular member 104 of the main frame 102 is a steering column support bracket 106 . The known steering column support bracket 106 includes an upper or top plate 108 having a substantially rectangular configuration as illustrated in FIG. 1 . Extending downwardly from opposing sides of the upper plate 108 are a pair of downwardly extending flanges 110 . The downwardly extending flanges 110 can be integral with or otherwise secured to a pair of webs 112 . In turn, the webs 112 , at their edges opposing the edges adjacent the downwardly extending flanges 110 , are coupled to or are integral with a pair of wings 114 . For purposes of mating the steering column support bracket 106 to the tubular member 104 , the downwardly extending flanges 110 each include an arcuate cut 116 having a shape conforming to the curvature of the outer surface of the tubular member 104 . In addition, each of the wings 114 also includes an edge having an arcuate cut 118 . Again, the arcuate cuts 118 are shaped to as to conform to the curvature of the tubular member 104 . With the arcuate cuts 116 , 118 , the elements of the steering column support bracket 106 securely mate with the tubular member 104 of the main frame 102 . FIG. 1 also illustrates a pair of bolts 122 which can be used to secure the steering column support bracket 106 to other components of the steering column itself.
[0018] For purposes of securing the steering support bracket 106 to the tubular member 104 , the support bracket 106 can be directly welded to the tubular member 104 , through MIG welding and resistance welding processes. Weld lines for the support bracket 106 and the tubular member 104 are shown as lines 120 in FIG. 1 .
[0019] As previously described, the known vehicle part 100 includes the steering bracket support column 106 which is comprised of steel or steel alloys, and which are of relatively substantial weight. To reduce the weight and still permit the use of welding processes to secure a support bracket to a main frame in the manufacture of the vehicle part, the preferred embodiment 200 illustrated in FIGS. 2-6 provides for a relatively lighter weight steering column support bracket, while still permitting the use of welding processes in the manufacture of the entirety of the vehicle part.
[0020] The preferred embodiment comprised of the vehicle part 200 is specifically shown in FIGS. 2-6 . As apparent from subsequent description, a number of the components of the vehicle part 200 correspond to the components of the vehicle part 100 with respect to the main frame. In fact, one of the advantages of the preferred embodiment is the addition of a relatively lighter weight magnesium part into the assembly of the steering column support bracket and main frame, without substantial modification to the assembly process. That is, the steering column support bracket in accordance with the preferred embodiment will still be MIG welded to components of the main frame.
[0021] More specifically, and with respect to FIGS. 2-6 , the vehicle part 200 includes a main frame 202 , shown substantially in its entirety in FIG. 2 . The main frame 202 , in this particular embodiment, is shown as an instrument panel reinforcement frame. However, it should be emphasized that numerous parts can be manufactured in accordance with processes associated with the preferred embodiment, other than the specific main frame and steering column support bracket described herein.
[0022] The main frame 202 includes a tubular member 204 extending substantially along the entirety of the length of the main frame 202 . Secured to the tubular member 204 of the main frame 202 , through welding processes, is a steering column support bracket 206 . The steering column support bracket 206 , when assembled with the main frame 202 , performs the same functions as the steering column support bracket 106 previously described with respect to the vehicle part 100 . However, unlike the steering column support bracket 106 , the steering column support bracket 206 of the preferred embodiment comprises a magnesium part 208 which is molded to weldable steel inserts 210 . The magnesium part 208 is shown in a perspective and stand-alone configuration in FIG. 6 . In accordance with the preferred embodiment, the magnesium part 208 is of a relatively lighter weight than steel components, and is the principle part of the assembly, the weldable steel inserts being smaller. Yet, the weldable steel inserts are sufficiently large as to space the magnesium part 208 sufficiently far from the welder to avoid igniting the magnesium during the welding process.
[0023] In addition to the magnesium part 208 , the steering column support bracket 206 also includes steel inserts 210 . The steel inserts 210 are also shown in a perspective and stand-alone configuration in FIG. 5 . As illustrated therein, the steel inserts 210 can include three inserts. The inserts are shown as center insert 212 and a pair of opposing side inserts 214 .
[0024] With respect to the center insert 212 , and as shown particularly in FIGS. 3 , 4 and 5 , the insert 212 includes a substantially rectangular top plate 216 . A pair of extending flanges 218 extend downwardly from the top plate on opposing sides thereof. The downwardly extending flanges 218 each include an arcuate cut 220 having a shape and configuration as primarily shown in FIG. 5 . The shape and configuration of the arcuate cut 220 will conform to the curvature of the tubular member 204 for purposes of mating the components together.
[0025] Turning to the side inserts 214 , each side insert 214 is comprised of an outwardly extending steel wing 222 . The steel wings 222 are shown in detail primarily in FIG. 5 . Each of the outwardly extending steel wings 222 includes a downwardly extending flange 224 . Each downwardly extending flange 224 includes an arcuate cut 226 . The arcuate cuts 226 , as with the arcuate cuts 220 , are also shaped so as to conform to the curvature of the tubular member 204 . In addition, and as will be apparent from subsequent description herein, the shape and configuration of the downwardly extending flanges 218 and 224 will conform to shapes and configurations of elements of the magnesium part 208 described subsequently herein.
[0026] Reference is now made to FIGS. 4 and 5 , showing the elements of the steel inserts 210 . As shown therein, the center insert 212 and side inserts 214 all include a series of holes 228 positioned at various locations on the inserts 210 . More specifically, and primarily with reference to FIG. 5 , three holes 228 are shown within the top plate 216 . A pair of holes 228 are shown in a top portion of each of the outwardly extending steel wings 222 . Further, holes 228 are positioned through the downwardly extended flanges 218 of the center insert 212 , and the downwardly extending flanges 224 of the side inserts 214 . In manufacture of the vehicle part 200 , the holes 15 will allow molten magnesium to flow from one side of a steel insert 210 to the other side thereof. When the magnesium hardens, the hardening action will serve to lock the steel inserts 210 in place, with respect to the magnesium part 208 . Without this locking function, the magnesium, in view of its properties, would not bond to the steel of the steel inserts 210 to any significant degree.
[0027] Reference is now made primarily to FIG. 6 , showing a stand-alone configuration of the magnesium part 208 . The magnesium part 208 includes, in this particular embodiment, a center portion 230 and a series of plates 232 at various angled configurations relative to one another. Positioned outwardly relative to the center portion 230 are a pair of extending members 234 , which extend from a front to a rear of the steering column support bracket 206 . Each of the extending members 234 includes an inner and downwardly extending flange 236 which can be integral with the sides of the plates 232 . At the bottom of the inner downwardly extending flanges 236 is a lower section 238 which can be positioned substantially at a right angle with respect to the corresponding flange 236 . Positioned on the lower sections 238 are a set of strengthening ribs 240 which extend from the front to the rear of the magnesium part 208 . A series of webs 242 , again for strengthening purposes, are positioned transversely across the ribs 240 . Extending upwardly from the lower sections 238 are a pair of outer flanges 244 . The magnesium part 208 can also include a set of formed bushings 246 , for purposes of receiving connecting components for securing the steering column support bracket 206 to other components of the steering column.
[0028] FIG. 3 illustrates a stand-alone, perspective view of the entirety of the steering column support bracket 206 , specifically showing the magnesium part 208 and the steel inserts 210 . The steel inserts 210 can be formed through conventional stamping processes. The magnesium part 208 can be formed as a casting through injection molding processes. During the molding processes, the steel inserts 210 , appropriately positioned with respect to the magnesium part molding configuration, are insert molded and over-molded.
[0029] To appropriately secure the steel inserts 210 to the magnesium part 208 , the previously described holes 228 are positioned relative to the mold for the magnesium part 208 , so that the holes 228 in the top plate 216 and in the upper portions of the outwardly extending steel wings 222 are located below the center portion 230 and the outwardly extending wings 248 of the magnesium part 208 . When in these positions, and also with respect to the holes 228 located in the flanges 218 and 224 of the steel inserts 210 , the holes 228 will permit molten magnesium injected into the mold to flow from one side of each of the steel inserts 210 to the other side. When the molten magnesium hardens, the resultant steering column support bracket 206 will have the configuration as particularly shown in FIGS. 3 and 4 . As apparent from the relative positioning of the steel inserts 10 and the magnesium part 208 as shown in these drawings, the steel inserts 210 are essentially locked in place relative to the magnesium part 208 . This function permits the steel inserts 214 to be coupled to the magnesium part 208 , without any use of welding or other connecting processes which are difficult to achieve with magnesium and similar metals.
[0030] In addition to the advantageous functions of the holes 228 , another aspect of the preferred embodiment for the vertical part 200 is the use of a series of beads 250 . The beads 250 are particularly shown in FIGS. 3 and 5 and are located on the steel inserts 210 . More specifically, the beads 250 can be characterized as being located at each position where there is a junction between a portion of the magnesium part 208 and a portion of the steel inserts 210 of the support bracket 206 . When the steel inserts 210 are positioned in the injection mold, and the molten magnesium is injected into the mold, the beads 250 serve to substantially prevent any molten magnesium from covering surfaces of the steel inserts which need to be exposed for purposes of facilitating welding of the steel inserts to the tubular member 204 .
[0031] Certain other aspects of the preferred embodiment and other embodiments can also be described. With respect to the holes 228 , it should be noted that the holes 228 can take other shapes and configurations within the steel inserts 210 . Of primary importance is that the holes or other formations in the steel inserts are positioned below what could be characterized as the “magnesium line” so as to allow the magnesium to flow through the holes or other formations during the molding stage, for purposes of effectively locking the steel inserts 210 to the magnesium part 208 .
[0032] With the steel inserts 210 forming part of the steering column support bracket 206 , the support bracket 206 can still be welded to the tubular member 204 or other components of the main frame 202 . That is, although the preferred embodiment advantageously utilizes a magnesium part 208 for the support bracket 206 , the use of the steel inserts 210 still provide the capability of welding (such as by MIG welding or resistance welding) the bracket 206 to the main frame 202 . Accordingly, the general process of assembling the steering column support bracket 206 to the main frame 202 is not substantially changed in that the bracket 206 is still welded to the tubular member 204 .
[0033] It is also possible to achieve the advantages of the embodiment, while having a differing relative configuration of the steel inserts 210 and the magnesium part 208 . For example, at least part of the steel inserts 210 could be positioned in other locations relative to the magnesium part 208 and the entirety of the support bracket 206 . That is, at least part of the steel inserts 210 could be positioned in the middle of the entirety of the support bracket 206 , with openings positioned within the magnesium part 208 . Such a configuration would allow for the capability of more extensive welding positions.
[0034] The steel utilized for the steel inserts 210 can be one of a number of variations. For example, it is believed that any 1008-1020 hot rolled, cold rolled or plate steel may be utilized for the steel inserts 210 . It may also be possible to utilize aluminum. However, a potential difficulty with the use of aluminum is that distortion must be avoided.
[0035] Also, it should be emphasized that the preferred embodiment described herein is directed specifically to a main frame 202 and steering column support bracket 206 . It is clear from the foregoing description that the advantageous processes associated with the preferred embodiment may be used for various types of structural components, in vehicles and for other purposes.
[0036] It will be apparent to those skilled in the pertinent arts that other embodiments of hybrid parts and processes associated with manufacture thereof can be designed. That is, the principles of hybrid parts and processes for manufacture are not limited to the specific embodiment described herein. Accordingly, it will be apparent to those skilled in the art that modifications and other variations of the above-described illustrative embodiment may be effected without departing from the spirit and scope of the novel concepts of the embodiment. | A light weight alloy part is molded in a mold containing at least one weldable metal insert, so that portions of portions of the alloy part lap portions of the insert to securely lock the weldable insert to the light weight alloy part. The resulting hybrid part is thus both light weight and weldable to other assemblies and sub-assemblies. | 1 |
This application is a continuation-in-part of U.S. patent application Ser. No. 08/184,477, filed on Jan. 21, 1994, now abandoned.
SCOPE OF THE INVENTION
This invention relates to hydraulic cement compositions containing an expanding component, more particularly a hydrated high alumina cement.
BACKGROUND OF THE INVENTION
Conventional concrete typically comprises Portland cement mixed with aggregate such as crushed stone, gravel and sand, and water. Such conventional concrete shrinks by as much as 0.05% to 0.1% by volume during the curing process. This shrinkage may be a disadvantage in certain applications.
It is known that the disadvantages of shrinkage may be at least partially overcome by mixing an expanding component with Portland cement to form an expansive cement. The expansive cement when mixed with aggregate and water forms an expansive concrete. The expanding component may either compensate for shrinkage of the concrete, or cause the concrete to expand during the curing process.
Portland cement is a type of hydraulic cement in the form of finely divided, gray powder composed of lime, alumina, silica, and iron oxide as in tetracalcium aluminoferrate (4CaO.Al 2 O 3 .Fe 2 O 3 ), tricalcium aluminate (3CaO.Al 2 O 3 ), tricalcium silicate (3CaO.SiO 2 ), and dicalcium silicate (2CaO.SiO 2 ). These are abbreviated, respectively, as C 4 AF, C 3 A, C 3 S, and C 2 S. Small amounts of magnesia, sodium, potassium, and sulfur may also be present. Hardening typically does not require air and will occur under water.
Portland cement is typically described as being made up of the following constituents:
______________________________________ CaO 60-64 wt. % SiO.sub.2 18-26 wt. % Al.sub.2 O.sub.3 4-12 wt. % Fe.sub.2 O.sub.3 2-4 wt. % MgO 1-4 wt. % Other 2 wt. %______________________________________
Portland cement is analyzed as if it were a mixture of the above oxides. However, it is not a simple mixture of these oxides but, rather, a complex mixture of aluminosilicates and oxides, some of which are described above. As used in this disclosure a reference to a percent by weight alumina does not indicate the presence of pure unbonded Al 2 O 3 but rather the presence of Al 2 O 3 in this weight percent in the compounds and complexes of hydraulic cement.
The expanding component is typically a mixture comprising high alumina cement (hereinafter sometimes referred to as HAC), gypsum and lime as its major components, for example in a weight ratio of HAC:gypsum:lime of about 22:10:3. HAC, also known as aluminous cement, is well known and typically comprises about 30% to 45% alumina by weight, and typically contains not more than about 60 to 62 wt. % calcium oxide. It is generally known that the formation of ettringite (3CaO.Al 2 O 3 .3CaSO 4 .32H 2 O) during the curing process is a source of expansive force in expansive cements.
Some commercially available expansive cements may be identified as for example Type K, Type M, and Type S, are based upon portland cements with added sulfoaluminate constituents which provide for the formation of ettringite. Type K cement contains portland cement, calcium sulfate and calcium sulfoaluminate; Type M-portland cement, calcium sulfate and calcium aluminate cement; and Type S-a high tricalcium aluminate portland cement and calcium sulfate.
While the mixing of an expanding component and Portland cement to form an expansive cement assists in overcoming the disadvantage of volume shrinkage, other difficulties arise by reason of the use of expansive cements. One serious disadvantage is that concrete made with highly expansive cement (hereinafter expansive concrete) tends to set extremely quickly, typically having an initial set time of about 10 minutes after mixing with water and a final set time of about 20 minutes after mixing with water. This rapid setting is at least partially caused by the rapid formation of ettringite crystals and other combined hydration products of various ingredients.
Rapid setting is desirable in some applications, such as highway and bridge repair, where it is necessary that concrete sets in a short period of time into a hard mass with sufficient strength to withstand applied stresses and loads.
However, the extremely rapid setting of expansive concrete containing an expansive cement is not always desirable. Under normal circumstances, conventional concrete formed for example with Portland cement and not containing an expansive component (hereinafter normal concrete) has an initial set time of 1 to 2 hours after mixing with water (the start of hydration) and a final set time of 6 to 8 hours after mixing with water. Such normal concrete may be prepared at a central mixing plant and transported some distance to a construction site where, for example, the concrete must remain workable until it is placed in a form or cavity.
It is known to include in both normal and expansive concretes admixtures such as retardants and superplasticizers. For example, it is known that the set time, both of normal Portland cements and expansive cements, can be somewhat extended by the addition of retardants such as sodium citrate and carboxymethylcellulose. However, for many applications these retardants may not achieve sufficient extension of the set time. As well, some of these retardants tend to suppress expansion, even when larger amounts of expansive cement are used. Superplasticizers such as that available under the trade mark LOMAR D are useful for improving the flowability of the concrete at lower water to cement content ratios.
SUMMARY OF THE INVENTION
To at least partially overcome these disadvantages of previously known devices, the present invention provides an expanding component for an expansive cement comprising alumina-bearing particles having an outer coating which delays reaction of alumina-bearing materials in the core of the particles with other materials.
An object of the present invention is to provide an alumina-bearing material for use in an expanding component of an expansive cement which substantially lengthens the set time of the expansive cement.
Another object is to provide an alumina-bearing material for use in an expanding component of an expansive cement which at least partially delays the interaction of the alumina-bearing material with other components in the expansive cement on hydration of the expansive cement.
Another object of the present invention is to provide an expansive cement in which the set time and degree of expansion can be varied and controlled.
Another object of the present invention is to provide an expansive cement in which retardants are not necessarily required to increase the set time.
Another object of the present invention is to provide an expansive cement which may be expansive or shrinkage compensating and which has a set time similar to that of ordinary Portland cement.
The inventor has surprisingly found that alumina-bearing particles having an outer coating can be used in the expanding component of expansive cements. The use of these particles preferably results in expansive cements which have set times approaching those of ordinary Portland cement, while retaining a degree of expansion similar to the original expansive cement. Furthermore, no retardants are necessarily required to extend the set time of expansive cement using preferred forms of this material. Therefore, the expansion of the expansive cement need not be hindered by retardants.
The alumina-bearing particles have an inner core which serves as a source of substantially unhydrated aluminates of hydraulic cement. An outer coating is provided about the inner core which delays reaction between the aluminates in the core and other materials in a cement composition.
Preferably the coating is water penetration resistant as it is believed that such a coating on the alumina-bearing material will slow the water-aided dispersion of aluminates in the expansive cement paste, which is formed by the mixture of water with the expansive cement. Therefore, less aluminates are available for the formation of ettringite, thus slowing the formation of ettringite. Since the rapid setting of expansive cement paste is believed to be at least partially due to rapid formation of ettringite and other hydration products, slowing their formation also lengthens the set time.
The inventors have also found that by varying the particle size of the alumina-bearing particles, by varying the amount of alumina-bearing particles in the expanding component, and by varying the amount of expanding component in the expansive cement, both the set time and the degree of expansion of the expansive cement paste and expansive concretes formed therefrom can be effectively varied and controlled.
As the inner core is to serve as a source of aluminates it preferably comprises substantially unhydrated aluminates of hydraulic cements such as tricalcium aluminate and tetracalcium aluminoferrate. Preferably these aluminates of hydraulic cement when measured as alumina represent a greater weight percent than found in Portland cement preferably greater than about 15%, more preferably greater than about 20% or greater than about 30% by weight of the material forming the inner core.
This inner core preferably contains not only such aluminates but also the conventional calcium components of hydraulic cement such as tricalcium silicate and dicalcium silicate. Preferably the inner core may comprise normal high alumina cement, HAC, powder which of course is understood to be unhydrated and containing aluminates in an amount representing of at least about 30% alumina by weight, as well as other normal calcium components of hydraulic cement.
The outer coating preferably comprises hydration products of the components found in hydraulic cements. Preferably, for simplicity of manufacture the outer coating may comprise hydration products of the substantially unhydrated materials forming the core. Thus in particularly preferred particles the core may comprise unhydrated high alumina cement and the outer coating may comprise the hydration products of high alumina cement, that is a layer of at least partially hydrated high alumina cement thereabout. Such preferred particles are hereinafter referred to as hydrated high alumina cement or H-HAC.
A method of forming the partially hydrated alumina-bearing particles involves the steps of forming a mixture of water and a finely divided powder containing unhydrated aluminates of hydraulic cement, allowing the mixture to at least partially set, then particularizing the resultant product as by breaking into particles, drying and grinding it into a resultant powder. The finely divided input powder of unhydrated aluminate preferably is a fine powder of particles having a size and size distribution similar to that of conventional hydraulic cements. For example, preferably no particles in the input powder are greater than about 75 μm, more preferably about 50 μm. Preferably no more than about 10 to 15% by weight of the input particles have a size less than about 5 μm. The average input particle size by weight is preferably in the range of about 10 to 50 μm, more preferably about 20 to 40 μm. When the finely divided powder of aluminates is allowed to set, preferably without calcium sulfate components or calcium oxide or calcium hydroxide present, it is believed that hydration products are first formed as an outer layer about the fine powder particles. At about the time of final set, the mixture then broken into particles, subsequent drying slows further hydration and assists in localizing hydration in an outer layer while leaving the inner core substantially unhydrated. Drying may be carried out positively as by leaving the particles in an open tray exposed to ambiant air for a period of time preferably about 24 hours or by heating for a shorter period of time. Drying may also occur merely in the course of exposure to air as in processes of crushing followed by grinding and/or size classification and separation.
In the setting process it is believed that the input, fine powder particles each comprising a core with a coating thereabout may come to clump together into larger clumps and clusters and/or to merge with other particles having coatings about one or more cores of substantially unhydrated material. The product is therefore mechanically broken by crushing and/or grinding to reduce the product to smaller clusters and clumps preferably with the maximum size of the resultant powder particles about 300 μm, more preferably 150 μm, and preferably with particles greater than about 75 μm.
Preferred H-HAC particles may be prepared by forming a mixture of HAC and water and allowing the mixture to at least partially set. This step of mixing the HAC with water and letting it set is referred to as "prehydration". It is preferred that the mixture be allowed to set for a time at least equal to the final set time. The length of time the mixture is allowed to set is the "prehydration age". After prehydration the mixture is as necessary mechanically broken into particles, dried, ground and if desired size classified.
An expanding component of the present invention is formed by mixing the alumina-bearing particles of the present invention with a form of calcium sulfate. The calcium sulfate may be anhydrous (CaSO 4 ), the hemihydrate (plaster of Paris, a.k.a "quick set" or "moulding" plaster, i.e. CaSO 4 .1/2H 2 O) or the dihydrate (gypsum, i.e. Ca 2 SO 4 .2H 2 O). The expanding component also preferably contains lime, the major component of which may either be calcium oxide or calcium hydroxide. Lime is only optionally added since Portland cement, with which the expanding component is mixed, may contain sufficient lime to allow the formation of ettringite.
The ratio of alumina-bearing particles to calcium sulfate in the expanding component is preferably from about 0.5:1 to about 4:1 by weight. When lime is added, the ratio of alumina-bearing particles to lime is preferably from about 4:1 to about 15:1 by weight, more preferably about 8:1.
An expansive component containing the alumina-bearing particles of the present invention may be combined with Portland cement to form an expansive cement. Such an expansive cement may either be one which expands during the curing process or one which does not expand but compensates for shrinkage of the cement during the curing process.
The preferred weight ratio of Portland cement to expanding component in the expansive cement of the present invention is preferably in the range of from about 1:1 to about 4:1. More preferably, the ratio of Portland cement to expanding component is from about 1.5:1 to about 2:1.
The expansive cement of the present invention may include a super-plasticizer, which improves the workability of concrete considerably without seriously affecting the expansion properties adversely. Preferred super-plasticizers are condensed naphthalene sulfonates. One such super-plasticizer is sold under the trade mark LOMAR-D, which is a naphthalene sulfonate condensate powdered superplasticizer. The weight ratio of the expanding component to superplasticizer in the expansive cement of the present invention is preferably about 10:1 to about 50:1, and more preferably 30:1 to 35:1.
In one aspect, the present invention provides a cement component comprising particles, each of said particles comprising: (a) an inner core comprising substantially unhydrated aluminates of hydraulic cement with the inner core comprising at at least about 30% alumina by weight; and (b) an outer coating which resists penetration of water into the inner core.
In another aspect, the present invention provides a partially hydrated high alumina cement powder comprising coated particles, each of said particles comprising: (a) an inner core comprising substantially unhydrated aluminates of hydraulic cement; and (b) an outer coating comprising hydration products of the inner core.
In yet another aspect, the present invention provides a cement composition, comprising: (a) a Portland cement component; and (b) an expanding component, comprising: (i) a partially hydrated alumina cement powder comprising coated particles, said particles comprising an inner core comprising substantially unhydrated aluminates of hydraulic cement and an outer coating which delays reaction between the aluminates of the core of the particles and other materials in the cement composition; and (ii) a calcium sulfate substance selected from anhydrous calcium sulfate, hemihydrate calcium sulfate and dihydrate calcium sulfate.
In yet another aspect, the present invention provides a method for preparing a partially hydrated high alumina cement powder, comprising the steps of: (a) forming a mixture of water and a finely divided powder of substantially unhydrated aluminates of hydraulic cement; (b) allowing the mixture of finely divided powder and water to set; (c) mechanically breaking the product of step (b) into particles; and (d) at least partially drying the particles.
In yet another aspect, the present invention provides a cement composition formed by mixing: (a) a Portland cement component; and (b) an expanding component, comprising: (i) a partially hydrated high alumina cement powder consisting of coated particles, said particles consisting of an inner core consisting of unhydrated high alumina cement and an outer coating consisting of hydration products of high alumina cement, said coating delaying reaction between the high alumina cement of the core of the particles and other materials in the cement composition; and (ii) a calcium sulfate substance selected from anhydrous calcium sulfate, hemihydrate calcium sulfate and dihydrate calcium sulfate; said partially hydrated high alumina cement powder being formed independently and prior to mixing with the remainder of the composition.
In yet another aspect, the present invention provides a cement composition formed by mixing: (a) a Portland cement component; (b) a partially hydrated high alumina cement powder; (c) a calcium sulfate substance selected from anhydrous, hemihydrate and dihydrate calcium sulphate, and (d) a calcium oxide substance selected from calcium oxide and calcium hydroxide; wherein said partially hydrated high alumina cement powder is formed independently and prior to mixing with the remainder of the composition by a process of: (i) forming a mixture consisting of water and unhydrated high alumina cement, the ratio of high alumina cement to water being from about 1:1 to about 4:1; (ii) allowing the mixture of high alumina cement and water to set; and (iii) mechanically reducing the product of step (ii) into a resultant powder.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will become apparent from the following description, taken together with the accompanying drawings, in which:
FIG. 1 shows a schematic elevation view of a steel tube mould used for testing of expansive concrete paste and expansive concrete.
FIGS. 2, 4, 6 and 8 are graphs showing the loss of flowability of expansive cement paste samples with time, with FIGS. 2 and 4 showing HAC expansive cement pastes and FIG. 6 and 8 showing H-HAC expansive cement pastes.
FIGS. 3, 5, 7 and 9 are graphs showing the free expansion of expansive cement paste samples with time, with FIGS. 3 and 5 showing HAC expansive cement pastes and FIGS. 7 and 9 showing H-HAC expansive cement pastes.
FIG. 10 comprises a graph showing the slump loss of a H-HAC expansive concrete sample.
FIG. 11 is a graph showing the development of compressive strength of both HAC and H-HAC expansive concrete samples.
FIG. 12 is a graph showing the free expansion of both HAC and H-HAC expansive concrete samples.
FIG. 13 is a graph showing the longitudinal expansion of laterally restrained HAC and H-HAC concrete samples.
FIG. 14 is a graph showing the lateral expansion pressure curves of both HAC and H-HAC expansive concrete samples.
FIG. 15 is a graph showing the friction stress of both HAC and H-HAC expansive concrete samples.
FIGS. 16 to 20 are graphs showing X-ray diffraction patterns of expansive cement paste samples at different times in the first 60 minutes of hydration, for cement paste samples M-1, M-2, M-3, M-4 and M-5, respectively.
FIGS. 21 to 23 are graphs showing X-ray diffraction patterns of expansive cement paste samples at day 1, day 3 and day 28, respectively.
FIGS. 24 to 28 are graphs showing relative intensities of sulphoaluminate, gypsum and hemihydrate of expansive cement paste samples at different times for samples M-1 to M-5, respectively.
FIGS. 29 to 31 are graphs showing a comparison of the relative intensities of sulphoaluminate, gypsum and hemihydrate, respectively, for expansive cement paste samples.
FIG. 32 is a graph showing the cumulative pore size distribution curves of expansive cement past samples at different times.
FIGS. 33, 34 and 35 are graphs showing differential pore size distribution curves of cement paste samples at 1, 3 and 20 days, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preparation of H-HAC
Preferred forms of the alumina-bearing particles of the present invention and the "prehydration" process for their preparation are now described.
In a preferred embodiment of the present invention, HAC powder is partially hydrated, mixed with water to form H-HAC and then, as necessary, mechanically broken into particles.
For example, HAC, such as that sold under the trade mark CIMENT FONDU by Canada Cement Lafarge Limited, is mixed with water using a water/cement weight ratio equal to 0.5. The HAC is prehydrated for a period of from 30 minutes before final set to about 7 days, during which time it attains a hardness ranging from that similar to wet sand to that of a hardened mass.
The HAC is preferably prehydrated for a period at least equal to the final set time. Beyond 24 hours, the length of prehydration age does not seem to have any substantial effect on the flow and setting behaviour of the expansive cement paste. The most preferred prehydration age is from 4 to 24 hours.
After prehydration, the H-HAC is preferably crushed and then preferably dried at room temperature for about 24 hours. It is then preferably ground into a fine powder having particles ranging in size from about 75 um to 300 um. Preferred particle size is from 75 um to 150 um. Grinding is not required when the H-HAC has been prehydrated for shorter periods of time, for example a period of 30 minutes less than final set time.
The resulting powdered H-HAC may then be combined with calcium sulfate (anhydrous, hemihydrate or dihydrate), and preferably also with lime (CaO or Ca(OH) 2 ) to form the expanding component. In one preferred example, the weight ratio of powdered H-HAC:calcium sulfate hemihydrate:hydrated lime in the expanding component is about 9:4:1.
The expanding component containing H-HAC can be combined with Portland cement to form an expansive cement. In one preferred example, the weight ratio of Portland cement to expanding component is about 1.5:1.
Expansive concrete can be formed from the expansive cement of the present invention by combining the expansive cement with water and aggregate in the same manner as ordinary Portland cement. In one preferred example, the weight ratio of expansive cement:stone:sand:water was about 5:8:7:2.
A small amount of superplasticizer may also be added to expansive concrete of the present invention to improve workability and minimize the amount of water needed. In one preferred example, the weight ratio of expansive cement to superplasticizer was about 130:1.
HAC cement powder is known to be a finely divided powder of particles, for example with an average particle size smaller than about 50 μm. Preferably the HAC powder used, as is typical, may have no particles greater than about 75 μm, more preferably 50 μm. Preferably no more than about 10 to 15% by weight of the particles have a size which is less than about 5 μm. The average particle size is preferably in the range of about 10 to 50 μm or about 20 to 40 μm.
The mechanism by which the expanding component containing H-HAC improves the setting behaviour of expansive cements is not well understood. According to the "Through Solution Theory", discussed in Mehta, "Effect of Lime on Hydration of Pastes Containing Gypsum and Calcium Aluminates or Calcium Sulfoaluminate", Hour. Amer. Ceramic Soc., Vol. 56, No. 6, 1973, p. 315 it is believed that the rate of ettringite formation is proportional to the concentration of Al 3+ ions in the concrete pore solution. As a result of the prehydration of particles of HAC, a coating or cladding of hydration products of HAC is formed on the surface of the HAC particles, resulting in the defined H-HAC particles. When the H-HAC particles are subsequently used in an expansive cement and mixed with water, it is believed that this cladding, on one hand, may resist water penetration into the unhydrated cores, and in any event on the other hand may reduce the ability of Al 3+ ions to disperse from the cladding. A relatively long time period is needed for the reactant Al 3+ ions to reach the saturated concentration under which the ettringite is crystallized. This slow accumulation of Al 3+ ions from the H-HAC particles allows the expansive cement paste to have the desired delayed setting behaviour.
Particle size plays an important role in controlling the degree and rate of expansion and the set time of the H-HAC-containing expansive cement. Smaller particles have a proportionally higher surface area per unit weight than larger particles. This higher surface area is believed to either increase the rate of dispersion of Al 3+ particles or increase the surface area from which the ettringite grows, or both. Therefore, the smaller the particle size, the faster the rate of ettringite formation and the shorter the set time. Accordingly, selection of appropriate fineness of H-HAC is not only important in controlling the quality of expansive cement, but also is a method of adjusting the rate of expansion, the ultimate value of expansion, and the set time.
The length of set time and the degree and rate of expansion may also be controlled by adjusting the amount of H-HAC in the expanding component and the amount of expanding component in the expansive cement. The higher the proportion of expanding component in the expansive cement, the higher the degree and rate of expansion and the shorter the set time.
Tests were conducted to compare expansive cement pastes and concretes according to the present invention including H-HAC powders with similar expansive cement pastes and concrete, including HAC powders rather than H-HAC.
Commercially available materials were used to prepare sample expansive cement pastes and concretes for the tests. These test materials are listed below with the name by which they are referred to hereinafter in the tables being shown in quotations or brackets:
1. as ordinary "Portland cement (OPC)", namely ASTM Type 1 or CSA Type 10 Portland cement;
2. as the expanding component, a mixture of CIMENT FONDU a high alumina cement sold by Canada Cement Lafarge Limited (HAC), quick setting plaster being calcium sulfate hemihydrate (quick set plaster) and hydrated finishing lime being calcium hydroxide (hydrated lime);
3. admixtures including the commercial retardant sold under the trade mark "DELVO", the retarder "sodium citrate", the superplasticizer sold under the trade mark "LOMAR-D", and "fly ash";
4. aggregates including sand and crushed limestone (stone) with a maximum size of 20 mm; and
5. water.
For the tests H-HAC powders were made from CIMENT FONDU (HAC) by the following process:
1. mixing CIMENT FONDU (HAC) with water using a water/cement weight ratio of 0.5;
2. casting it in 100×200 mm plastic cylinder mould;
3. letting the mixture set for one of the designated "prehydration ages";
4. after prehydration for the designated prehydration age, as necessary to particulize, crushing the H-HAC;
5. drying the H-HAC at room temperature for 24 hours;
6. grinding the H-HAC into a fine powder; and
7. separating it into different sizes by sieving.
Six representative test H-HAC powders were prepared by this process. These six powders are described Table 1 which sets out for each sample the "Prehydration Age", the particle size and the sample number of either the "cement paste" or "concrete" in which the H-HAC was included. The prehydration ages were chosen to be a minimum of 30 minutes before final set for powder B; 1.5 hour after final set for powder C; 1 day after mixing with water for powders A, E and F; and 7 days after mixing with water for powder D. For powder B with a prehydration age of 30 minutes before final set there was no crushing or grinding or size separation as the resultant H-HAC was a particulate material after removal from the mould. For the powder other than sample B, sieving separation was selected to provide powders with H-HAC particles in the ranges of either less than 75 μm, 75 μm to 150 μm or 150-300 μm.
Cement Paste Samples--EP Series
Cement paste samples were prepared from the test materials utilizing either the preferred H-HAC powders or the Cement Fondue (HAC) powder. The composition of fourteen of these cement paste samples are shown in Table 2 in which each component is indicated by mass in grams.
Each cement paste sample comprises Portland Cement, an expanding component, water and optional admixtures. The expanding component comprises quick set plaster and hydrated lime plus either CIMENT FONDU HAC powder or one of the H-HAC powders. A small amount of superplasticizer, Lomar D was used in each H-HAC cement paste in Table 2 as it was appreciated that larger water to cement ratios (w/c) would be needed to achieve preferred workable pastes.
The components of each cement paste were mixed in accordance with the "Type of Mixing Process" fully described in Table 5.
Regarding Table 2, samples EP1, EP2, EP37, EP38, and EP40 to 43 inclusive are the HAC cement paste samples prepared with HAC powder. Samples EP49 to EP54 inclusive are the H-HAC cement paste samples prepared with the various H-HAC powders.
Cement Pastes--Flowability Tests
Tests were conducted on the cement pastes of Table 2 to determine the loss of flowability with time after adding the expansive components.
A flow table in accordance with ASTM C-230-68 was used to determine the change of flowability of the cement pastes. The method employed did not exactly follow this ASTM Standard, because the flow of the cement pastes with admixtures usually exceeded the range of the table. In most cases, the cement paste flowed by gravity without preforming any drops. The results are graphically shown in FIGS. 2 and 4 for HAC cement pastes and FIGS. 6 and 8 for H-HAC cement pastes. In FIGS. 2, 4, 6 and 8, the percent flow is shown as measured at various times in minutes after adding the expansive component to the cement pastes.
FIGS. 2 and 4 show eight HAC sample cement pastes with a horizontal axis of 60 minutes and are to be contrasted with FIGS. 6 and 8 showing the H-HAC sample cement pastes with a horizontal axis of 200 to 250 minutes. The H-HAC sample cements other than EP50 have improved loss of flowability compared to the HAC sample cement pastes. H-HAC sample cement paste EP50 had the shortest prehydration age of 30 minutes before final set and was comparable in loss of flowability with single step mixed HAC samples E1 and E2. FIG. 6 shows that the flow percent increases with prehydration age for the H-HAC pastes with the prehydration age increasing from EP50 to EP51 to EP49 to EP52. FIG. 8 shows that the flow percent increases for the H-HAC pastes with increase in particle size in that H-HAC sample EP53 has particles of less than 75 μm; H-HAC sample EP49 has particles of 75-150 μm and H-HAC sample EP54 has particles of 150-300 μm.
Cement Paste--Initial and Final Set Tests
Tests were conducted on the cement pastes of Table 2 to determine the initial and final setting time by the method of ASTM C 807-89. In this test, after flow decreased with time to less than 10%, the paste was compacted in a PVC cone, the surface was finished and the initial and final setting times were measured in minutes by a Vicat apparatus. The results are shown in Table 4.
All of the H-HAC sample cement pastes E49 and E51 to E54 had substantially greater initial and final set times than the HAC sample cement pastes EP40 to EP43, with the exception of H-HAC sample cement paste EP50. H-HAC sample cement paste EP50 had a prehydration age of less than the final set time. H-HAC sample cement paste EP51 had the next lowest set times and was the sample with the next lowest prehydration age of 1.5 hours after final set. A comparison of H-HAC samples EP49, EP53 and EP54, each of which had prehydration ages of 1 day and with H-HAC sample EP52 having a prehydration age of 7 days suggests that after 24 hours, the prehydration age of H-HAC cement paste does not appear to have a substantial effect on the setting behaviour of the paste.
Cement Paste--Free Expansion Tests
Tests were conducted on the cement pastes of Table 2 to determine the free expansion with time. In these tests, when the flow of the paste had decreased to less than 10%, two expansion specimens were cast in steel prism moulds to produce 25×25×125 mm (1×1×5 inches) specimens with expansion studs at the ends providing a gauge length of (125 mm/5 in.). The specimens were cured initially in a sealed plastic box under the relative humidity of 100% and temperatures of about 23±3° C. (74±5° F.). Some specimens were demoulded after 24 hours and others just after final setting. Initial lengths of the specimens were measured immediately after demoulding. After 24 hours drying in the sealed boxes, the specimens were set in water. The expansion was read once a day until the specimens cracked or the lengths of the specimens became constant.
The results are shown in FIGS. 3, 5, 7 and 9 as graphs showing free expansion as a percentage of the initial lengths versus the number of days after mixing with water. The term "break" shown in FIGS. 3, 5, 7 and 9 is used at the end of an expansion curve to indicate the specimen is cracked to the extent that further measurements would not be meaningful.
The expansion of the H-HAC cement pastes are shown in FIGS. 7 and 9 to be somewhat comparable with the expansion of the HAC cement pastes EP1 without any admixtures. HAC cement paste EP1 without any adjunctives had the greatest expansion. HAC cement pastes EP37, EP38, EP40 and EP41 had low expansion which is believed to be due to the presence of substantial admixtures.
The effects of prehydration age of the H-HAC powders on flow and free expansion of the H-HAC cement paste samples are shown in FIGS. 6 and 7. The initial and final set times of H-HAC cement paste samples are compared with HAC cement paste samples in Table 4. The H-HAC particle size in H-HAC cement paste samples EP49, EP51 and EP52 varied between 75 μm and 150 μm. The results suggest that a prehydration age at least equal to final set time is preferred to achieve satisfactory flow characteristics of the H-HAC cement pastes. Beyond 24 hours, the prehydration age of H-HAC does not seem to have substantial effect on the flow and setting behaviour of the H-HAC cement pastes. Even with prehydration age of 1.5 hours longer than final set, initial and final set times of approximately 6 hours were recorded for the H-HAC paste samples. The effect of prehydration age of H-HAC on free expansion of the H-HAC cement paste is minimal as shown in FIG. 7. Compared to HAC-type expansive cement pastes as shown in FIGS. 3 and 5 the expansion characteristics of H-HAC cement pastes as shown in FIGS. 7 and 9 are significantly better with respect to the total expansion and the delay in expansion. Since the use of admixtures in the H-HAC cement paste samples is minimal, the loss of measurable expansion is believed to have been minimized.
The effects of particle size of the H-HAC powders on flowability and expansion of the H-HAC cement pastes are shown in FIGS. 8 and 9. The prehydration age of H-HAC in HHAC cement pastes EP49, EP53 and EP54 was 24 hours. As expected, reduced particle size results in faster initial reaction. Reduced particle size of H-HAC gave the H-HAC cement pastes a lower flow, a larger flow loss with time and a faster set. When the particle size decreased from 75-150 μm to less than 75 μm, the expansion of the H-HAC cement paste developed earlier. The ultimate amount of expansion was, however, very similar with both H-HAC samples EP53 and EP49. With an increase in the particle size from 75-150 for EP49 to 150-300 μm for EP54, the development of expansion was greatly delayed and, as well, the ultimate expansion appears to have been reduced. For the H-HAC cement pastes under consideration, a particle size of H-HAC in the range of 75-150 μm appears to be preferred.
Concrete Samples--E Series
Concrete samples were prepared from the test materials utilizing either the prepared H-HAC powders of Table 1a or the CIMENT FONDU (HAC). The composition and mixing processes of five concrete samples are shown in the Table 3 of which expansive concrete sample E11 is made with H-HAC by one stage mixing and samples E6 to E9 inclusive are made with CIMENT FONDU (HAC) by various mixing processes indicated and fully defined in Table 5. For H-HAC cement sample E11, a small amount of a superplasticizer LOMAR D was used as it was appreciated that larger water to cement ratios (W/C) would be needed otherwise to achieve preferably workable concrete.
Concrete Sample--Slump Test
Slump values were measured for H-HAC cement sample E11 over two hours as shown in FIG. 10. The behaviour of sample E11 was very similar to that of normal Portland cement concrete including similar amounts of superplasticizers. For sample E11, initial slump of approximately 160 mm (6.2 inches) maintained for about 30 minutes and at 60 minutes the slump was still about 100 mm (4 inches).
Concrete Samples--Compressive Strength and Friction Stress Tests
To simulate the actual stress state with three dimensional restraint, a set of steel tube moulds for casting and curing expansive cement pastes/concrete was designed, as shown in FIG. 1. The lateral expansion of expansive concrete was restrained by the steel tube 1 and the longitudinal expansion was restrained by two steel end plates 2 tightly held in place by three 8 mm diameter threaded rods 3. The tube 1 has a 100 mm inner diameter and 200 mm length with a 6 mm thick wall. Twenty holes 4 of 5 mm diameter were made symmetrically in four columns to allow supply of water during hydration. The expansive concrete was cured in the mould in air at 100% relative humidity and about 25° C. for 24 hours after casting and then placed in 23° C. water. At designated ages, steel plates 2 were removed and the expansive concrete cylinder was squeezed out using a universal testing machine. During the demoulding process the friction stress between the expansive concrete and the inside of the steel tube could be measured from the maximum load required to remove the expansive concrete cylinder from the tube. The compressive strength was obtained from testing the squeezed-out specimens.
FIG. 11 illustrates the development of compressive strength of the expansive concrete samples over a period of 90 days. The strength of HAC concrete samples E6 and E7, both containing no fly ash, was the highest mainly because of the lower water:cement ratio used. The addition of fly ash and a higher proportion of water to HAC concrete samples E8 and E9 to improve workability of the concrete resulted in a reduction in strength. FIG. 11 shows the compressive strength for unconfined expansive concrete. In actual field conditions, expansive concrete is typically confined laterally when subjected to axial stress and will, therefore, display much higher strength.
The H-HAC concrete sample E11 displayed lower strength than comparable HAC sample E6 at an early age, but at later stages the two concretes had similar strength values. Compared to normal concrete made merely with normal Portland cement, the strength development of all the expansive concrete samples shown in FIG. 11 is delayed by several days. This effect is pronounced in H-HAC concrete sample E11.
FIG. 15 shows the frictional stress in MPa as measured at different times for each concrete sample. H-HAC concrete sample E11 had friction stresses comparably as large to those for HAC cement sample E6 without admixtures.
Concrete Samples--Free Expansion Tests
Expansive concrete was cast in PVC cylinder moulds 100 mm in diameter, 200 mm long with 3 mm thick walls with expansion studs embedded at the ends. After curing for 24 hours in moist air, the specimens were demoulded. The original length of a specimen was obtained by averaging four measured lengths of concrete cylinder on symmetric sides. The initial length including two targets was measured immediately after demoulding, and then specimens were cured in water. The length changes were determined daily.
The changes in linear free expansion with time of samples E6, E8 and E11 are shown in FIG. 12. The addition of fly ash to HAC sample E8 delayed expansion by about 2 days over HAC sample E6. However, the total free expansion of HAC samples E6 and E8 are comparable.
As shown in FIG. 12, the H-HAC concrete sample E11 had a delayed development of expansion by about 9 to 10 days. The rate of expansion of H-HAC concrete sample E11 at about 12 days is similar to that of HAC concrete sample E6 at about 3 days. The total measured free expansion of H-HAC concrete sample E11 was slightly higher than that of HAC samples E6 and E8. However, it should be noted that, due to extensive cracking of the specimens, the free expansion measurements do not necessarily reflect the true quantitative effects of different parameters.
Concrete Samples--Two Dimensional Restrained Expansion Tests
The expansive concrete specimens for two dimensional restrained expansion tests were cast in PVC tubes with 3 mm thick walls, 120 mm long and 100 mm inner diameter. Two expansion studs were installed in the centre at the ends. The initial length of a specimen was obtained by averaging four measured lengths of concrete cylinder on symmetric sides including tow targets after one-day of moist curing. Then the specimens with PVC tube moulds were stored in 23° C. water. The length changes were determined daily. In this test, the restraint was applied to the expansive concrete from the wall of PVC tube in the lateral direction. In the longitudinal direction the only restraint could have come from the friction between concrete and the PVC walls.
FIG. 13 shows the results of this test as the percent restrained expansion versus time in days. H-HAC concrete sample E11 had expansion closest to that of HAC sample E6 without admixtures.
Concrete Samples--Expansion Pressure Tests
A test mould for measuring this parameter was designed similar to that shown in FIG. 1. A thin walled steel tube was used to provide lateral restraint and two end steel plates tightly installed by three 8 mm diameter threaded rods acted as longitudinal restraint. The expansive concrete specimen inside the tube was 150 mm in diameter and 300 mm long. The wall thickness of the tube was 3 mm. Several strain gauges were installed to measure the changes in lateral and longitudinal strains during concrete expansion. Each rod contained one strain gauge in the axial direction. The outer surface of each tube was instrumented with three strain gauges, one in the axial direction and two in the circumferential direction. The holes in the steel tubes were made for easy flow of water as mentioned above for the strength test specimens. One hour after casting the expansive concrete, initial strain readings were taken. The specimens were cured in air at 100% relative humidity and 25° C. for 24 hours, and then placed in 23° C. water. Readings were recorded every day for each specimen.
The test results are shown in FIG. 14 plotting the lateral expansion pressure in MPa versus time in days. Again H-HAC concrete sample E11 was comparable to HAC concrete sample E6 without admixtures.
Reference is made again to FIGS. 13, 14 and 15 respectively showing the variation with age of longitudinal expansion, the lateral expansion pressure, and the friction stress of the expansive concrete samples. HAC concrete sample E6 displayed the most expansion, the largest expansive pressure and the largest friction stress. The addition of admixtures to HAC concrete sample E7 greatly reduced its expansive potential, as is apparent in all three parameters measured in FIGS. 13 to 15. A comparison of HAC concrete samples E7 and E8 shows that an increase in the water to cement ratio and perhaps addition of fly ash reduce the expansive potential of the concrete.
It is obvious from FIGS. 13 to 15 that the gain in workability due to admixtures in the HAC expansive concrete is obtained at the expense of expansive potential. By comparing HAC concrete samples E8 and E9, it is apparent that increasing the amount of expanding component compensates somewhat for the loss of restrained expansion and friction stress without significant adverse effects on strength and workability, but the development of lateral expansion pressure is not improved.
FIGS. 13 to 15 show that H-HAC concrete sample E11 of the present invention compared quite favourably with HAC concrete sample E6. Although the restrained expansion of H-HAC concrete E11 is somewhat lower than that of HAC concrete E6, expansion pressure and friction stress in E6 and E11 are of reasonably similar magnitudes. Delay in the development of expansive pressure in H-HAC concrete E11 due to the use of H-HAC is beneficial in some applications, such as in drilled shafts.
Cement Pastes--M Series
Additional cement paste samples were prepared from the test materials utilizing either the preferred H-HAC powder A of Table 1 or the CIMENT FONDU (HAC) powder. The composition of five additional cement paste samples are shown in Table 6 in which each component is indicated by mass. In Table 6, Samples M-1, M-2 and M-3 are HAC cement paste samples while samples M-4 and M-5 are H-HAC cement paste samples.
Fresh Paste Samples
To measure the hydration process of expansive cement paste samples of Table 6 in the fresh state, two grams of solid materials were mixed continuously and uniformly with their relative proportion of water or water-admixture solution in a glass beaker at 23° C. The hydration periods were fixed at 1, 3, 5, 10, 20, 30 and 60 minutes. At the designated time, the hydration of the fresh paste was terminated by adding 30 ml of propanol, and then the samples were filtered in a funnel with qualitative filter paper (grade 601-25). After washing the sample by propanol three times on the filter paper, the remnant on the paper was dried in a vacuum dessicator with a negative pressure of 100 kPa for 48 hours. Then the sample was ground together in an agate mortar with 100% CaF 2 as an internal standard.
X-ray diffraction patterns of the five expansive fresh paste samples M-1 to M-5 during hydration in first 60 minutes are presented for each sample, respectively in FIGS. 16 to 20 and at three later ages in FIGS. 21 to 23, as measured with an X-ray diffractometer using Copper Kx radiation. In FIGS. 16 to 23, A represents Al 2 O 3 , B represents CaSO 4 .1/2H 2 O, CH represents Ca(OH) 2 , G represents gypsum, SA represents calcium sulphoaluminate, C 2 S represents 2CaO.SiO 2 and C 3 S represents 3CaO.SiO 2 . Calculated from these FIGS. 21 to 23, the relative intensities of three designated minerals, Gypsum (G), Hemihydrate (B) and calcium sulphoaluminate (SA), are presented in FIGS. 24 to 28, respectively for each respective cement paste sample and in FIGS. 29 to 31 for each respective mineral. Calcium sulphoaluminate (SA) is used here to designate the combination of monosulphoaluminate (3CaO.Al 2 O 3 .CaSO 4 .12H 2 O) and ettringite (3CaO.Al 2 O 3 .3CaSO 4 .32H 2 O). With hydration, the intensities of SA obviously increased. In samples with admixtures the increase in SA intensities at an early age was larger than in the sample without admixtures. In HAC cement samples M-1, M-2 and M-3, the hemihydrate peak diminished expeditiously and disappeared before 60 minutes with corresponding increase of gypsum peak. In the H-HAC cement samples M-4 and M-5, the hydration rate seemed very slow. Hemihydrate existed in the pastes for 24 hours and the intensity of SA was quite small in first 60 minutes even with admixture. With the increase of SA formation, gypsum was greatly consumed, which resulted in the decrease of gypsum's relative intensity at later ages as seen in FIGS. 29 to 31. Since the same content of plaster (hemihydrate) was used in all the mixtures, the relatively lower gypsum intensity mostly corresponded with a high rate of SA formation. The peak shift from 9.90° to 9.05° 2θ as hydration proceeded showed the composition change of calcium sulphoaluminate from monosulphoaluminate to ettringite. The patterns of cement pastes with admixtures exhibited a distinct background hump due to amorphous phase in the range of from 8° to 25° 2θ as seen in FIGS. 16 to 20 indicating acceleration of the hydration rate.
As seen in FIG. 21 in the X-ray diffraction analyses of expansive cement pastes after one day, it was obvious that the sulphoaluminate peak of the HAC cement pastes M-2 and M-3 with admixtures was higher than that of the HAC cement paste M-1 without admixtures, but no obvious difference could be found between the two samples M-2 and M-3 with different mixing processes. In the H-HAC cement paste samples M-4 and M-5, the SA peaks were much lower than that in the HAC type expansive cement, indicating a reduced rate of SA formation.
As seen in FIG. 22 at 3 days, the X-ray diffraction pattern of expansive cement pastes were similar to those at 1 day. But the relative intensities of designated minerals (SA, G or B) in different expansive cement pastes became somewhat similar.
As seen in FIG. 23 at 28 days, the five expansive cement pastes were not discernably different even in the intensity of each peak. The major hydration products were ettringite and calcium hydroxide while some unhydrated clinker phase such as C 3 S and C 2 S were also noted. However no characteristic peaks representing the hydration products of HAC, such as 3CaO.Al 2 O 3 .6H 2 O could be detected.
Hardened Paste Specimens
To explore the microstructure of expansive cement paste, hardened specimens were prepared from the paste samples of Table 6 under conditions simulating those in real drilled shafts. Cylindrical specimens 26 mm in diameter and 50 mm high were cast in small steel tube moulds with 2 mm thick walls. Two 8 mm thick steel plates were placed at bogh ends of the steel mould and tightly screwed together using three 6 mm diameter threaded rods. At each end of the mould, there were two holes (3 mm in diameter each) for water supply during hydration. In the first 24 hours, the specimens were cured in air at 100% RH and 23° C., and then stored in 23° C., tap water. During the entire curing process, the specimens were subjected to three dimensional restraint. At designated ages, the threaded rods were removed and the steel moulds were cut longitudinally to obtain the paste cylinder specimens. The procedure was followed to avoid damage to the cement pastes during demoulding. Hardened paste from the central section of the specimen was then taken and crushed into 3-10 mm diameter particles. The hardened pastes were immersed in propanol for 24 hours to terminate hydration and then dried in a vacuum dessicator at a negative pressure of 100 kPa for 48 hours. The hardened pastes were then ground and sieved into three grades: particles with diameter of about 10 mm were chosen for scanning electron microscopy; particles with diameter of about 2-3 mm were favoured for porosimeter tests; and the rest of the material was ground together with 100% CaF 2 as an internal standard for X-ray diffraction tests.
A scanning electron microscope was used to evaluate the crystal growth and compare the expansion cracks existing in the hardened specimens of the cement paste of Table 6 with different admixtures and curing ages. Under the particular restraint conditions in the steel mould, the widths of cracks varied from 10 um to 30 um and they increased with an increase in age at early ages, but then decreased dramatically at 28 days. The surface texture of the 28-day specimens was dense and most remaining micro cracks were closed. At early ages, they were quite porous and the cracks extended through the sample.
At early ages, average crack widths of the HAC cement pastes M-2 and M-3 with admixtures were larger than those in HAC pastes M-1 without admixtures. While in the H-HAC expansive cement pastes M-4 and M-5 the crack widths were only about one-fifth of those in the HAC cement paste M-1, M-2 and M-3. At 28 days, the surface morphology of paste M-5 was totally different from those at early ages. Only traces of sulphoaluminate crystals could be found in some isolated areas.
The morphologies of SA in pastes at different ages were also studied with the scanning electron microscope. In the HAC cement paste M-1 without admixtures large size SA crystals (about 15-60 um long and 6 um in diameter) were commonly found. But in the HAC cement pastes M-2 and M-3 with admixtures, only small needle-shaped SA crystals existed in clusters, which these smaller crystals being about 3-5 μm long and 1 um in diameter. Although in the HHAC cement pastes M-4 and M-5 some SA crystals located in pores or cracks were large, about 10-20 μm long and 2 um in diameter, most other crystals were still smaller than those observed in the HAC cement pastes M-2 and M-3 with admixtures.
At early ages, most of the SA crystals appeared as conglomerations irregularly interlocked with each other, and those in the pores or cracks grew from solid side surfaces into the open space. At 28 days, ettringite could not easily be detected or identified because of the extreme dense structure of the hardened paste. Occasionally, some small clusters of ettringite could be found in the pores or some weak areas.
Cumulative pore size distribution curves of the expansive cement pastes hardened specimens were measured using a mercury intrusion porosimeter with a contact angle assumed to be 140°. The results are shown in FIG. 32. With hydration, cumulative pore volumes at all sizes decreased in all the pastes. At 28 days, the volume of pores larger than 400 A tended to be zero. This indicated that hydration products had filled in the pores. The total pore volume of H-HAC cement paste M-4 and M-5 was slightly higher than that of HAC cement pastes M-1, M-2 and M-3.
FIGS. 33 to 35 show the differential pore size distribution curves at different ages for expansive cement pastes. The most probable pore sizes (MPPS) of these samples at one-day (FIG. 33) were in the range of 600 A° to 3000 A°. The HAC pastes M-1 and M-2 without admixture had the same MPPS of 3000 A°. As a result of using admixtures, the MPPS shifted to smaller sizes. At 3 days of hydration (FIG. 34) the MPPS range for these samples was between 300 A° and 900 A°. The effect of admixtures on the character of distribution curves was the same as that at one day.
FIG. 35 demonstrates differential pore size distributions of 28-day pastes. The MPPS were very low, from 80 A° to 160 A°. The MPPS of the H-HAC cement pastes M-4 and M-5 was larger than that of HAC cement pastes M-1, M-2 and M-3. This large reduction in pore volume is not common in normal cement pastes even incorporating silica fume, indicating that when restrained, expansive cements at later ages could have an extremely dense structure and high strength.
TABLE 1______________________________________Design of H-HAC PowdersH-HAC Particle Size Prehydration Cement Paste orPowder um Age Concrete Sample______________________________________A 75-150 1 day EP 49, E 11, M-4, M-5B No grinding 30 min. before EP 50 needed final setC 75-150 1.5 hr. after EP 51 final setD 75-150 7 days EP 52E 75 1 day EP 53F 150-300 1 day EP 54______________________________________
TABLE 2__________________________________________________________________________Mix Design of Expansive Cement Paste SamplesUnits: Mass H-HAC Speci- Type of Cement Particle Quick men Mixing Portland Fondu Size Pre-hydration Set Hydrated Sodium Lomar Fly No. Process Cement (HAC) Content of (μm) Age Platter Lime Water Delvo Citrate D Ash__________________________________________________________________________ EP1 MPD-I 480 200 -- -- -- 96 24 320 -- -- -- -- EP2 MPD-I 480 200 -- -- -- 96 24 320 4 -- -- -- EP37 MPD-I 400 250 -- -- -- 120 30 320 2.4 -- 12 -- EP38 MPD-I 400 250 -- -- -- 120 30 320 -- 0.3 12 -- EP40 MPD-I 400 250 -- -- -- 120 30 368 -- 0.3 12 120 EP41 MPD-II 400 250 -- -- -- 120 30 368 -- 0.3 12 120 EP42 MPD-III 400 250 -- -- -- 120 30 368 -- 0.3 12 120 EP43 MPD-IV 400 250 -- -- -- 120 30 368 -- 0.3 12 120 EP49 MPD-I 480 -- 200 75-150 1 day 96 24 320 -- -- 6 -- EP50 MPD-I 480 -- 200 No 30 min. before 96 24 320 -- -- 6 -- grinding final set needed EP51 MPD-I 480 -- 200 75-150 1.5 hr. after 96 24 320 -- -- 6 -- final set EP52 MPD-I 480 -- 200 75-150 7 days 96 24 320 -- -- 6 -- EP53 MPD-I 480 -- 200 <75 1 day 96 24 320 -- -- 6 -- EP54 MPD-I 480 -- 200 150-300 1 day 96 24 320 -- -- 6 --__________________________________________________________________________
TABLE 3__________________________________________________________________________Proportions of Expansive Concrete SamplesSpeci- Type of Cement Mould- Hyd-men Type of Mixing Portland Fondu ing rated Sodium FlyNo. Concrete Process OPC/EC Cement (HAC) H-HAC Plaster lime Water W/C Stone Sand Citrate Lomar Ash__________________________________________________________________________E6 HAC one-stage 60/40 306 128 -- 61 15 217 0.43 902 742 -- -- --E7 HAC two-stage 60/40 306 128 -- 61 15 217 0.43 902 742 0.19 7.6 --E8 HAC two-stage 60/40 306 128 -- 61 15 316 0.54 756 524 0.19 7.6 76E9 HAC two-stage 50/50 260 163 -- 78 19 300 0.50 772 534 0.20 7.8 79E11 H-HAC one-stage 60/40 306 -- 128 61 15 217 0.43 902 742 -- 3.8 --__________________________________________________________________________
TABLE 4______________________________________Initial and Final Set of Cement Paste Samples Initial Set Final Set Sample (minutes) (minutes)______________________________________ EP 40 65 78 EP 41 67 72 EP 42 130 210 EP 43 155 230 EP 49 480 510 EP 50 27 31 EP 51 348 378 EP 52 486 516 EP 53 426 486 EP 54 510 540______________________________________
TABLE 5______________________________________Design of Special Mixing ProcessesType of MixingProcesses Procedures of Mixing______________________________________MPD-I Mix all the cementitious materials (and aggregates,(one stage mixing if any) in the mixer for 3 minutes. Add the water withprocess) dissolved retarder and superplasticizer and mix for 3 minutes.MPD-II Mix Portland cement plaster and water with dissolved(two-stage mixing retarder and superplasticizer in the mixer for 3process) minutes; Wait for 5 minutes; Add the rest of the materials (Ciment Fondu, Lime and fly ash) with the previously mixed paste for 3 minutes.MPD-III Mix Portland cement, fly ash, plaster and water with(two-stage mixing dissolved retarder in the mixer for 3 minutes;process) Wait for 5 minutes; Add the rest of the materials (Ciment Fondu, Lime and superplasticizer) with the previously mixed paste for 3 minutes.MPD-IV Mix Portland cement, fly ash and water with dissolved(two-stage mixing retarder (and aggregates, if any) in the mixerprocess) for 3 minutes; Wait for 5 minutes; Mix the expansive components and superplasticizer with the previously mixed paste for 3 minutes.______________________________________
TABLE 6__________________________________________________________________________Proportions of Expansive Cement Paste SamplesUnits: mass Expansive Components S-BearingOrdinary Material AdmixturePortland Al-bearing Material Quick Set Hydrated Sodium Type of MixSample Cement HAC H-HAC Plaster Lime Lomar-D Citrate Water Process__________________________________________________________________________M-1 0.6 0.25 -- 0.12 0.03 -- -- 0.43 MPD-I One-stageM-2 0.6 0.25 -- 0.12 0.03 0.015 0.000375 0.43 MPD-I One-stageM-3 0.6 0.25 -- 0.12 0.03 0.015 0.000375 0.43 MPD-IV Two-stageM-4 0.6 -- 0.25 0.12 0.03 -- -- 0.43 MPD-I One-stageM-5 0.6 -- 0.25 0.12 0.03 0.0075 -- 0.43 MPD-I One-stage__________________________________________________________________________
The expansive cement of the present invention is particularly useful in highly expansive concrete compositions for use in drilled shafts (bored piles). Bored piles are used to support foundations of structures such as buildings and bridges when the soil is unsuitable for supporting stresses transmitted by the foundation.
Expansive concrete compositions having a free expansion of about 4% can be used for bored piles. These expansive concretes produce a stronger bond between the shaft concrete and the surrounding soil, (ie. higher "skin friction"), thus enabling the shaft-soil system to carry a higher load. Settlement is also reduced due to the increased load transferred to the soil by the sides of the shaft.
In tests conducted by Sheikh et al., "Expansive Concrete Drilled Shafts", Canadian Journal of Civil Engineering, Vol. 12, No. 2, 1985, pp. 382-395, it was determined that the use of expansive concrete increased skin friction by 25-50% and reduced settlement by about 50% in shafts built in over consolidated clay.
Although the invention has been described in connection with certain preferred embodiments, it is not intended that it be limited thereto. Rather, it is intended that the invention cover all alternate compositions, equivalents, and embodiments as may be within the scope of the following claims. | A hydraulic cement composition is disclosed which utilizes as part of an expansive component novel coated particles of high alumina cement. The particles have a core of substantially unhydrated high alumina cement and an outer layer of hydration products of the core, which outer layer delays the reaction of the particles with other materials in the composition. By varying the nature and relative amounts of the coated particles the amount the cement composition may expand and the setting time of the cement may be varied. The coated particles may be formed by partial hydration, drying and grinding of a mixture of high alumina cement powder alone with water. | 2 |
RELATED APPLICATIONS
This application is a continuation in part of U.S. application Ser. No. 09/642,450 filed Aug. 18, 2000 now U.S. Pat. No. 6,482,235 and claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/298,605 filed on Jun. 14, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to devices and instrumentation for intervertebral disc diagnosis and treatment, and methods thereof.
2. Description of the Related Art
An intervertebral disc performs the important role of absorbing mechanical loads while allowing for constrained flexibility of the spine. The disc is composed of a soft, central nucleus pulposus surrounded by a tough, woven anulus fibrosis. Herniation is a result of a weakening in the anulus. Symptomatic herniations occur when weakness in the anulus allows the nucleus to bulge or leak posteriorly toward the spinal cord and major nerve roots. The most common symptoms of herniation include pain radiating along a compressed nerve and lower back pain, both of which can be crippling for the patient. Herniation, and the resulting dehabilitating symptoms, are of significant medical concern in the United States because of the low average age of diagnosis. Indeed, over 80% of patients in the United States diagnosed with herniation are under the age of 59.
Information regarding anular thickness, internal dimensions of the disc space normally occupied by the nucleus, and the location of anular apertures and lesions in relation to the vertebral endplates and lateral walls of the anulus facilitates accurate diagnosis and treatment of intervertebral disc conditions. For example, medical procedures involving the implantation of an artificial nucleus or anular augmentation depend on this information for accurate sizing of such implants. Also important are safe, dependable, and minimally invasive methods and devices for the manipulation of anular and nuclear tissue, especially along the inner wall of the posterior anulus. For example, tissues in the anulus and nucleus are commonly removed or manipulated during the implantation of artificial discs either to clear a path for the insertion of other types of prosthetic devices or as part of a discectomy procedure.
Specialized tools have evolved for the surgical treatment of intervertebral discs in the lumbar, cervical, and thoracic spine, which have suffered from tears in the anulus fibrosis or herniation of the nucleus pulposus. These tools are well-known in the prior art. The devices of the prior art, however, are designed for specific procedures, including complete discectomies (as opposed to partial discectomy or minute removal of tissue) and the installation of vertebral fusion implants. Accordingly, these devices cannot be used to manipulate anular and nuclear tissue in a precise and minimally invasive manner. Moreover, such devices are typically designed to access the disc using an anterior approach, i.e., through the abdomen. Although an anterior surgical approach provides direct access to intervertebral discs, it is highly invasive to the abdominal organs. Thus, surgery is typically more complicated and time consuming. A direct posterior approach is not anatomically practicable because the spinal cord and its surrounding bony protective sheath lies directly in front of each vertebral disc. An posterior-lateral aspect approach is the least invasive of these methods but provides limited and oblique access to the disc and its interior. Depending upon the surgical necessities involved, several methods of percutaneous disc tissue manipulation are available, including chemonucleolysis (e.g., U.S. Pat. No. 4,439,423), laser (e.g., U.S. Pat. No. 5,437,661), manual, focused energy, ultrasonic disruption (e.g., U.S. Pat. No. 5,772,661), arthroscopy and endoscopy.
Endoscopic instrumentation has evolved over the past 25 years and permits viewing, irrigation, suction, and cutting. Probes that permit automated percutaneous suction such as nucleotomes or cylindrically housed rotating cutting means, such as debreders, provide gross but efficient removal of disc tissue. Varying tip profiles control the amount and direction of tissue resection as well as the likelihood of damage to surrounding tissue. These devices tend to be limited by the size of the cannula which houses the instrumentation and its ability to maneuver around vertebral bodies and delicate tissues of the spine.
Hand tools for use in the spine are also well known and can be inserted through cannulae or freely guided by hand. These tips may be blades, burs, rongeurs, curettes or forcep-like “graspers” that are capable of pinching of small amounts of material. To the extent that these instruments can access the various tissues, these devices provide good tactical feedback and control. However, if used in an antero-lateral spinal approach, these tools are generally limited by the indirect approach necessitated by the laminae and spinous processes of the adjacent vertebrae, and thus, access to tissues is substantially hampered.
Some intervertebral disc devices have been designed with flexible tips that are designed not to perforate or deflect off of the interior surface of the disc. Unfortunately, such tips deflect off of healthy disc tissue only, not the pathological tissue that caused the need for the surgery in the first place. Thus, such instrumentation can exit the anulus and cause considerable damage to the surrounding tissues and spinal cord. Also, the flexible probe tips on some instruments which permit access to remote locations within the disc can only do so by sacrificing direct control because the devices are passively guided or blindly “snaked” within the disc. Accordingly, delicate and precise work within a disc is not possible with such instruments.
Among other disadvantages, the devices and methods of the prior art are typically invasive and destructive to surrounding tissue, frequently causing disc infection and nerve root injury. Moreover, such devices are unable to precisely manipulate disc material along the posterior anulus in a minimally invasive manner. Accordingly, there is a need for an intervertebral disc diagnostic and manipulation device which is capable of performing delicate and precise work within a disc, especially along the posterior anulus and between anular lamella.
SUMMARY OF THE INVENTION
The current invention relates generally to devices and instrumentation for intervertebral disc diagnosis and treatment, and methods thereof. In several embodiments, the present invention provides for a minimally invasive and actively guided intervertebral disc repair and diagnostic device. This device provides direct and consistent access to the inner surface of the posterior anulus and will not unintentionally exit the posterior anulus and cause harm to the spinal cord. One skilled in the art will understand that this device is not limited to intervertebral disc applications, but includes medical procedures in which a minimally invasive, actively guided device for diagnosis, repair or treatment is desired. These procedures include, but are not limited to, arthroscopic, endoscopic, and endovascular applications. Further, one skilled in the art will appreciate that, in many embodiments, this invention may be used percutaneously or intralumenally.
Various embodiments of the invention may be guided by tactile feedback or through active viewing. Also, various embodiments may be used in conjunction with medical imaging technologies, including MRI, ultrasound, or fluoroscopy. Further, several embodiments of the invention having radiopacity or selective radiopacity may be used in conjunction with imaging methods for guidance and/or to facilitate measurement of organs or tissues.
Various embodiments of the current invention are particularly advantageous because they provide active controlled direction of the working end of the instrument within the anulus or nucleus. Further, several embodiments provide access to the posterior portion of the anulus using a posterior surgical approach. In various embodiments, access to the posterior anulus, via circumferential navigation of the instrument as it is deflected from the lateral, anterior, opposite lateral, and finally to the posterior anulus, is avoided. This is advantageous because circumferential deflection of the working end of the instrument within the anulus can result in the tip of the instrument passing through a fissure in the posterior anular surface and outward to the spinal cord. This can occur because the circumferential navigation from a typical posterior surgical approach eventually directs the tip perpendicular to the posterior anular surface, which may contain lesions large enough to allow protrusion of the tip directly through to the spinal cord.
There is provided in accordance with one aspect of the present invention, a device for treating the spine. The device comprises an elongate guide having a longitudinal axis. An axially moveable actuator is carried by the guide. A probe is movable with the actuator, and a deflection surface is carried by the guide. Axial movement of the actuator causes the probe to advance along the deflection surface and extend away from the guide at an angle to the longitudinal access of the guide.
In one implementation of the invention, the guide comprises an elongate tubular body having at least one lumen extending therethrough. The actuator extends through at least a portion of the guide. The probe may comprise an elongate flexible body, attached to the actuator. The probe may be biased in a nonlinear configuration. In one embodiment, the probe comprises a nickel titanium alloy.
In accordance with another aspect of the present invention, there is provided a method of treating a disc in the spine. The method comprises the steps of advancing a device at least part way through an anulus. A probe is advanced laterally from the device in a first direction along a portion of the anulus.
In one application of the invention, the advancing a probe step comprises advancing the probe in between adjacent (anular lamella) layers of the anulus. In another application of the invention, the advancing a probe step comprises advancing the probe along an interior surface of the anulus, between the anulus and the nucleus. The method may further comprise the step of repositioning the probe and advancing the probe in a second direction along a second portion of the anulus.
In accordance with a further aspect of the present invention, the method additionally comprises the step of introducing media through the delivery device and into the disc. In one application, the media comprises contrast media, to permit fluoroscopic visualization. The media may alternatively or additionally comprise a medication, and/or a nucleus augmentation material. The method may additionally comprise the step of introducing a prosthesis into the disc. The prosthesis may be introduced by proximately retracting a push rod from a lumen in the delivery device, and introducing the prosthesis into the disc through the lumen.
As will be appreciated by those of skill in the art, the present invention, therefore, provides a minimally invasive access pathway into the anulus and/or nucleus of a vertebral disc. The pathway may be utilized to perform any of a wide variety of procedures, including diagnostic and therapeutic procedures, some of which will be identified below.
Several embodiments of this invention provide a new intervertebral disc manipulation and diagnostic device.
One or more embodiments disclosed herein provide a convenient, reliable, and accurate way to measure the anular thickness and the internal dimensions of the disc space normally occupied by the nucleus pulposus.
Several embodiments of this invention provide a device useful in determining various disc dimensions in order to enable a surgeon to size various implants and tools and facilitate their guidance within the disc.
Various embodiments provide for the manipulation through an opening in the anulus. Manipulation includes, but is not limited to, dissection, resection or ablation of disc tissue. The opening may be a single iatrogenic hole, such as an anulotomy, a naturally occurring hole, or a lesion in the anulus.
One or more aspects of the current invention prepare or manipulate disc tissue in preparation for the insertion of an implant or other instruments.
Several embodiments of the present invention diagnose and manipulate disc tissue with minimal invasiveness and risk of unintended passage of the device outside of the posterior anulus in the direction of the spinal cord or other sensitive areas proximal thereto.
Various aspects of this invention permit direct access to the interior aspect of anulus via an anulotomy.
Several embodiments of invention provide an intervertebral disc manipulation and diagnostic device wherein the travel of the working end of the device is parallel to the lamellae of the anulus.
This disclosure utilizes particular orthopedic references, nomenclature, and conventions. Accordingly, several background figures and descriptions are included to aid in the understanding of the environment under which specific embodiments of the invention may be used. In this description and the following claims, the terms “anterior” and “posterior”, “superior” and “inferior” are defined by their standard usage in anatomy, i.e., anterior is a direction toward the front (ventral) side of the body or organ, posterior is a direction toward the back (dorsal) side of the body or organ; superior is upward (toward the head) and inferior is lower (toward the feet).
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show the general anatomy of a functional spinal unit 345 . FIG. 1A is a view of a transverse section. FIG. 1B is a view of a sagittal section. FIG. 1C shows the same functional spine unit with a defect in the anulus, which may have been created iatrogenically, as in the performance of an anulotomy, or may be naturally occurring.
FIGS. 2A and 2B are front and side views of a device in accordance with the present invention.
FIG. 3 is an isometric view of the distal end of the device.
FIG. 4 is a side view of the depth stop components of the device including depth-measuring markings, the depth stop adjustment knob, and the depth stop body.
FIG. 5 is a side view of the delivery cannula, cannula handle and intradiscal tip.
FIG. 6 is a side view of the advancer, with a ring-handle.
FIG. 7 is a cross-sectional view of the device with the intradiscal tip positioned within an anulotomy. The probe and depth stop are both retracted, and the distal end of the device has been inserted to a depth beyond the anterior aspect of the posterior anulus.
FIG. 8 depicts the probe of the device advanced relative to its starting position in FIG. 7 above.
FIG. 9 depicts the intradiscal tip of the device with the probe resting on the inner surface of the posterior anulus.
FIG. 10 depicts the device with the depth stop advanced to the posterior surface of the posterior anulus.
FIG. 11A is a side view of the intradiscal tip of the device showing a variation of the probe tip. In this variation, the trailing edge of the reverse-curved tip has been sharpened. In FIG. 11B, the same intradiscal tip is shown with the probe advanced from its initial retracted position.
FIG. 12 is a top view of the probe from FIGS. 11A and 11B shown unformed. The probe is shown as it would appear prior to forming, if it were formed from a flat sheet of material, sharpened along one edge.
FIG. 13A is a side view of the intradiscal tip of the device, showing a variation of the probe tip. In this variation, the distal end of the reverse-curved tip is spaced further distally from the distal end of the device than that of the probe depicted in FIGS. 11 a-b . In FIG. 13B the same device is shown with the probe advanced from its initial retracted position.
FIG. 14 is a top view of the probe from FIGS. 13A and 13B shown unformed. The reverse curve that forms the distal tip of the probe is shown as it would appear prior to forming, if it were formed from a flat sheet of material.
FIG. 15A is a side view of a variation of the probe tip. In this variation, the tip of the reverse curve has two additional flanges of material on either side of the curve. The combination of tip elements forms a scoop. In FIG. 15B the same device is shown with the probe advanced from its initial retracted position.
FIG. 16 is a top plan view of the probe from FIGS. 15A and 15B shown unformed. The two side flanges and the reverse curve that forms the distal tip of the probe are shown as they would appear prior to forming, if they were formed from a flat sheet of material.
FIG. 17A is a top view, and FIG. 17B is a side view of the distal end of the device of an embodiment of the invention. The probe includes an ablation unit, control wires, and a tube, mounted to the probe proximal of the distal tip. The anvil of the device has material removed in its central area to allow the retraction of the tube and control wires into the device.
FIG. 18 is a transverse view of the intervertebral disc wherein the device is being used to measure the anterior to posterior distance from the anulotomy to the inner aspect of the anterior anulus.
FIG. 19 is a transverse view of the intervertebral disc wherein the probe is advanced from the anulotomy to the far lateral corner.
FIG. 20 is a transverse view of the intervertebral disc wherein the probe is advanced from the anulotomy to the near lateral corner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In one aspect of the invention, there is provided a guide such as a hollow delivery cannula having a distal end and a proximal end. The guide is dimensioned to fit within a small anulotomy as might be created by a surgeon or through a naturally occurring hole or lesion in the anulus. An advancer, push rod, or actuator is axially moveably carried by the guide, and coupled to a flexible probe member. The flexible probe member has a proximal end connected to the advancer and distal end connected to or formed into a probe tip.
The probe is advanceable outwardly from the distal end of the cannula via axial movement of the advancer within the cannula. In the illustrated embodiment, the probe member exits through a slot having a curved pathway or deflection surface located at the distal end of the cannula and can be advanced outwardly therefrom generally at an angle of between about 30 to about 150 degrees relative to the cannula's longitudinal axis. Accordingly, when the distal end of the cannula is properly inserted within the anulotomy at sufficient depth, the probe travels along a path that is parallel to and along the surface of or in between the anular lamellae. The probe may be retracted via reversing the action (e.g. proximal retraction) of the advancer.
A means for measuring the distance advanced by the probe is associated with the probe and cannula. Any of a variety of measurement indicia may be used, such as calibrated markings on the advancer visible through or proximal to the cannula. An indicator for measuring the distance advanced by the cannula within the anulotomy or lesion may also be included. For example, a calibrated depth stop may be affixed in a slideably adjustable manner to the delivery cannula.
The probe tip at the distal end of the probe member may be an integral piece of the probe wherein the tip and the probe are of a unitary construction. Alternatively, the tip may be secured, either releasably or permanently to the probe. The tip can be blunt enabling it to forcibly part the tissue without cutting it (blunt dissection) or be sharpened to present a sharp dissecting blade surface (sharp dissection).
The tip may also be constructed in a backwardly curved manner facing back towards the longitudinal axis of the cannula and with its reverse facing edge sharpened to facilitate resection or sharp dissection as it is retracted. This curved shape also serves to present a blunt profile that is less likely to perforate the anulus as it is advanced, even in the presence of uneven or degenerated anular tissue. Alternatively, the curved resection tip or blade may be formed as a multi-sided scoop with a concave trailing surface and convex leading surface such that it presents a blunt frontal profile even when advanced off-angle into the anulus or toward a vertebral endplate.
In another embodiment, the tip may be configured to house an ablation element. This element may be preferentially insulated on particular surfaces of the probe and/or tip to minimize unwanted damage to adjacent tissues. For example, the surface of the probe or tip facing an inner aspect of the anulus may be insulated to prevent unwanted travel through or harm other portions of the anulus, nucleus and vertebral endplates. Ablation energy is instead directed to the targeted tissue adjacent to the probe tip and not the endplates or tissue facing the insulted side of the probe tip.
FIG. 1A is an axial view along the transverse axis M of a vertebral body with the intervertebral disc 315 superior to the vertebral body. Axis M shows the anterior (A) and posterior (P) orientation of the functional spine unit within the anatomy. The intervertebral disc 315 contains the anulus fibrosus (AF) 310 which surrounds a central nucleus pulposus (NP) 320 . Also shown in this figure are the left 370 and right 370 ′ transverse spinous processes and the posterior spinous process 380 .
FIG. 1B is a sagittal section along sagittal axis N through the midline of two adjacent vertebral bodies 350 (superior) and 350 ′ (inferior). Intervertebral disc space 355 is formed between the two vertebral bodies and contains intervertebral disc 315 , which supports and cushions the vertebral bodies and permits movement of the two vertebral bodies with respect to each other and other adjacent functional spine units.
Intervertebral disc 315 is comprised of the outer AF 310 which normally surrounds and constrains the NP 320 to be wholly within the borders of the intervertebral disc space. Axis M extends between the anterior (A) and posterior (P) of the functional spine unit. The vertebrae also include facet joints 360 and the superior 390 and inferior 390 ′ pedicle that form the neural foramen 395 .
Referring FIG. 2 a , the device 10 , a cannula handle 35 , and a ring handle 45 are positioned such that the device 10 may be operated by one hand, i.e. utilizing the thumb, index, and ring fingers to position the device 10 and advance and retract the probe member 20 . However, any of a variety of proximal handpieces can alternatively be used, including triggers, slider switches, rotatable knobs or other actuators to advance and retract the probe 20 as will be apparent to those of ordinary skill in the art in view of the disclosure herein.
In FIG. 5 the cannula handle 35 is secured to the proximal end 32 of an outer delivery cannula 30 . Outer delivery cannula 30 extends from the proximal end 32 to a distal end 34 which is provided with an intradiscal tip 50 . Delivery cannula 30 functions as a guide for the axial reciprocal movement of a push rod 40 as will be discussed. Delivery cannula 30 may, therefore, be provided in the form of an elongate tube having a central lumen for receiving push rod 40 therethrough. Alternatively, the guide may comprise a nontubular structure, in an embodiment in which the push rod travels concentrically over or alongside the guide.
The delivery cannula 30 may be manufactured in accordance with any of a variety of techniques well known in the medical device arts. In one embodiment, the cannula 30 comprises a metal tube such as stainless steel or other medical grade metal. Alternatively, the cannula 30 may comprise a polymeric extrusion such as high density polyethylene, PTFE, PEEK, PEBAX, or others well known in the medical device arts.
In general, the axial length of the delivery cannula 30 will be sufficient to reach the desired treatment site from a percutaneous or small incision access through the skin. Lengths within the range from about 10 centimeters to about 30 centimeters are contemplated, with a length from a proximal end 32 to distal end 34 within the range of from about 14 to about 20 centimeters contemplated for most posterior lateral access pathways. The length may be varied depending upon the intended access pathway and patient size.
Preferably, the outside diameter of the delivery cannula 30 is no greater than necessary to accomplish the intended functions disclosed herein. In general, outside diameters of less than one centimeter are preferred. In typical embodiments of the present invention, the delivery cannula 30 has an outside diameter of no greater than approximately 5 millimeters.
Referring to FIG. 6, the push rod or advancer 40 comprises an elongate body 42 having a proximal end 44 and a distal end 46 . Push rod 40 may comprise a solid rod or tubular component as may be desired, depending upon the construction materials and desired physical integrity. In one embodiment, the push rod 40 comprises a solid metal rod, such as stainless steel or other suitable material. Alternatively, a polymeric extrusion using any of a variety of known medical grade polymers may be used.
Push rod 40 is preferably dimensioned to extend throughout the length of the delivery cannula 30 , so that the probe 20 is fully extended from the intradiscal tip 50 when the ring handle 45 is brought into contact with the cannula handle 35 or other stop surface.
The device 10 may optionally be provided with one or more axially extending lumens, for placing the proximal end of the device 10 in fluid communication with the distal end, for any of a variety of purposes. For example, one or more lumens may extend through the push rod 40 . Alternatively or in addition, the outside diameter of push rod 40 may be dimensioned smaller than the inside diameter of the delivery cannula 30 to create an annular space as is well understood in the catheter arts. A first lumen may be utilized for introduction of radiopaque dye to facilitate visualization of the progress of the probe 20 and or distal end of the device 10 during the procedure. The first lumen or second lumen may be utilized to introduce any of a variety of media such as saline solution, or carriers including any of a variety of medications such as anti-inflammatory agents e.g,. steroids, growth factors e.g., TNfα antagonists, antibiotics, and functional proteins and enzymes e.g., chympopapain. A lumen may also be utilized to aspirate material such as nucleus pulposus, and/or to introduce nucleus augmentation material during or at the end of the procedure.
Referring to FIG. 7, the distal end 34 of device 10 is shown in cross section. Distal end 34 includes an axially moveable probe member 20 , an outer delivery cannula 30 and an advancer or inner push rod 40 . A curved passage or slot 60 is proximal an intradiscal tip 50 of the delivery cannula 30 . The passage or slot 60 includes a curved distal deflection surface which acts to deflect the probe member 20 in a path that is roughly parallel to the lamellae of the posterior anulus fibrosus 310 as the probe member 20 is advanced outwardly from the curved slot 60 and into the disc 315 by the advancer 40 .
The distal end 34 of the cannula 30 may be provided with any of a variety of constructions, depending upon the mode of deflection of the probe 20 . In the illustrated embodiment, the distal end 34 is provided with a cap 52 which contains the deflection surface 62 therein. Cap 52 may be molded from any of the polymeric materials identified elsewhere herein, and secured to the distal end 34 by adhesive bonding, interference fit, or other conventional securing technique. Cap 52 has an atraumatic distal surface 50 , which may comprise the distal end of cap 52 , or may include a coating or layer of an atraumatic material such as silicone, carried by the cap 52 .
Any of a variety of alternative deflection surfaces may be used, depending upon the desired distal tip design. For example, the distal molded cap 52 may be eliminated, and the deflection surface formed instead by an inside surface of the tubular cannula 30 . This may be accomplished by providing two opposing axial slots extending proximally from the distal end 34 of the cannula 30 to isolate two opposing axial ribbons on the distal end 34 . A first one of the ribbons is severed and removed, while the second one is curved across the central axis of the cannula 30 to provide a curved deflection surface.
Alternatively, the deflection surface may be eliminated in certain circumstances. For example, in the procedure illustrated in FIG. 7, the device is inserted through a defect in the posterior annulus at an angle relative to the desired treatment plane that requires the probe 20 to exit the device at a corresponding angle in order to advance the probe along the surface of or within the annulus as shown (e.g., within or parallel to the desired treatment plane). However, by moving the access path through the annulus roughly 80-90 degrees counterclockwise as viewed in FIG. 7, the longitudinal axis of the device 10 can be positioned coplanar or parallel to the posterior interior surface of the annulus or other desired treatment plane. In this orientation, the probe is desirably launched axially out of the end of the cannula 30 , to dissect a space for subsequent annulus patch implantation.
The foregoing axial launch embodiment of the invention may be utilized through the naturally occurring defect. However, the axial launch device is more likely to find application through an iatrogenic access pathway, created through the annulus spaced apart from the natural defect such that the longitudinal axis of the iatrogenic access is substantially parallel (e.g., no more than about +/−20 degrees) from the plane in which the natural defect resides.
As a further alternative, the probe 20 may be laterally deflectable in response to manipulation of a deflection control at the proximal end of the device 10 . For example, the probe 20 in one construction comprises a flexible metal or polymeric ribbon, extending from the distal end of the advancer 40 or other axial support. An axially extending steering element is attached to the probe 20 . Generally the steering element will be attached near the distal end of the probe 20 . Axial proximal or distal movement of the steering element relative to the advancer 40 will cause a lateral deflection of the probe 20 .
The radius of curvature of the deflection can be controlled in a variety of ways as will be apparent to those of skill in the art in view of the disclosure herein, such as by varying the lateral flexibility of the probe 20 , and the attachment point of the steering element to the probe 20 . Due to the differing physical requirements of devices under tension compared to compression, the cross section of the device may be minimized if the steering element is a pull wire or ribbon such that axial proximal retraction of the pull wire relative to the probe 20 causes a lateral deflection of the probe 20 . The lateral deflection can be coordinated with the extent of distal advance to cause the probe to follow the desired curved path either by mechanics in the proximal handpiece, or by the clinician. For this purpose, the proximal handpiece can be provided with any of a variety of controls, such as slider switches or rotatable levers or knobs to allow the clinician to control deflection as well as distal (and lateral) advance.
In an alternate construction, the probe launches axially from the distal end 34 of the cannula or other guide 30 , but curves under its own bias to travel in a lateral arc and slide along the posterior annulus or other desired surface. This may be accomplished by constructing the probe from a nickel—titanium alloy such as Nitinol and providing it with a lateral pre bent orientation. The probe is restrained into an axial orientation within the cannula 30 , but extends laterally under its own bias as it is advanced distally from an opening in the distal end of the cannula 30 .
The probe member 20 in the illustrated embodiment may be formed from a superelastic nickel titanium alloy, or any other material with suitable rigidity and strain characteristics to allow sufficient deflection by deflection surface 62 without significant plastic deformation. The probe member 20 can be formed from an elongated sheet, tube, rod, wire or the like. Probe 20 may also be constructed in various cross-sectional geometry's, including, but not limited to hemicircular, semicircular, hollow, and rectangular shapes.
A probe tip 80 at the distal end of the probe member 20 can be used to dissect between the anulus 310 and nucleus 320 , to dissect between layers of the anulus 310 , or to dissect through the nucleus. The probe tip 80 can be constructed of the same material as the probe member 20 or another suitable material for the purposes of cutting or presenting a blunt rounded surface. A sharpened surface on the distal edge of the probe member 20 forming the probe tip 80 can be used to dissect a path to enable the insertion of an implant in the created space. Similarly, a blunted tip profile may be used to separate or disrupt anular lamella and create an open space between the anulus 310 and nucleus 320 or within the nucleus 320 itself.
The probe tip 80 may also be provided with a backward curve as shown in FIGS. 11A and 11B. In this construction, a concave surface faces the longitudinal axis of the device when deployed within the disc. The tip 82 may be sharpened to facilitate resection or sharp dissection as it is retracted. This curved shape will also serve to present a blunt profile to reduce the risk of perforating the anulus 310 as it is advanced, even in the presence of uneven or degenerated anular tissue. The curved tip 80 may be formed in any of a variety of radii or shapes depending on the amount of material one desires to remove on each pass of the probe member 20 into the disc, as shown in FIGS. 13A and 13B. Alternatively, the resection tip 80 or blade may be formed as a multi sided concave scoop 81 having a cavity therein such that it presents a blunt convex frontal profile even when advanced off-angle into the anulus 310 or toward a vertebral endplate 350 , as shown in FIGS. 15A and 15B. Also, the increased surface area of such a scoop 81 would serve to further facilitate removal of disc tissue.
The distal end of device 10 is shown in FIG. 7 as inserted through a defect in the posterior anulus 300 . Alternatively, the device 10 could be inserted through defects in the posterior-lateral, lateral, or anterior anulus 300 . In these alternate positions, the probe tip 80 can be advanced parallel to the lamellae of different regions of the anulus 310 . One of the many advantages of the curved, distal probe tip 80 , as represented in several embodiments of the current invention, is its minimal profile when the probe is in its retracted state relative to the outer cannula 30 . In this state, depicted in FIG. 7, the curved tip 80 fits around the distal end of intradiscal tip 50 , only minimally increasing the size or profile of device 10 . This minimizes the size of the defect in the anulus 300 necessary to allow proper insertion of the distal end of device 10 .
As demonstrated in FIGS. 11 and 13, various geometry's of the tip 80 can be employed without increasing the necessary anular defect or anulotomy 300 size for insertion of the intradiscal tip 50 of the device 10 . For example, the larger radius of the probe tip 80 in FIG. 13 presents a blunter dissection profile when advanced from the intradiscal tip 50 without necessitating a correspondingly larger anulotomy 300 for proper insertion of the device 10 into the disc. As the bluntness of probe tip 80 is increased, it may be desirable to increase the stiffness of the probe 20 . This increased stiffness may be achieved in a variety of ways which can include, but is not limited to using a thicker or more rigid material for forming probe 20 , or by using a curved cross-sectional shape along the length of probe 20 . These techniques may be used to stiffen all or a portion of the length of probe 20 .
The probe tip 80 may also be coupled to an ablation unit for ablating tissue, as shown in FIGS. 17A and 17B. The ablation unit can be attached to the probe member 20 preferably on the side facing the interior of the disc and proximal to the probe tip 80 . In this configuration, the probe member 20 acts as a mechanical and thermal barrier minimizing unwanted ablation in the direction opposite the ablation unit, i.e. in the direction facing the interior aspect of the anulus. Ablation may be achieved using any of a variety of energy delivery techniques including, but not limited to light (laser), radio-frequency or electromagnetic radiation in either unipolar or bipolar configurations, resistive heating of the probe, ultrasound or the like.
An embodiment of a bipolar radio-frequency unit is depicted in FIG. 17 . Power and control wires 91 may be deposited directly on to the probe member 20 as is known in the art. These wires act to connect RF elements 90 to an external power source and control unit affixed to or in communication with the advancer 40 and cannula 30 . These elements 90 serve to allow the conduction of current therebetween, resulting in a resistive heating of the tissue in the region of the probe tip 80 . These elements 90 are shown proximal to the distal probe tip 80 of device 10 , but may be positioned at any location along probe 20 and/or on probe tip 80 . Only two elements 90 are shown, however numerous elements may be positioned at various locations along the entire length of the probe 20 and be activated individually or multiplexed in pairs or groups to produce a desired temperature profile or ablation within the disc tissue.
Tube 92 is shown attached to probe 20 to provide an escape path for vapor and material ablated or for the infusion of fluids or gasses. These fluids or gasses may be added to alter the conductive characteristics of the tissue or may include various drugs, medications, genes or gene vectors or other materials to produce a desirable therapeutic affect. Tube 92 is shown with a single distal orifice. It may alternatively comprise any number of side holes or channels to increase the spread of fluids or gasses within the tissue or similarly to remove such materials as required by the procedure. Axial lumen are provided as needed to place the side holes or other apertures in communication with the proximal end of the device 10 . The ablation unit could be activated as the probe member 20 is advanced through the tissues to create a cavity or activated as the probe member 20 is retracted after it has been advanced to a desired distance. Moreover, the power supplied to the ablation unit 90 could be varied according to the instantaneous velocity of the probe member 20 in order to ablate a more uniform cavity within the disc.
Whether used to dissect, resect or ablate tissue within the disc, device 10 may be used as part of an implantation procedure by creating a cavity or dissected region into which any of a variety of intradiscal implants or medications may be inserted. This region may be between or within anular layers 310 , within the nucleus 320 , or between the anulus 310 and nucleus 320 . It may include a portion or the entirety of the nucleus. Increasing amounts of disc tissue may be removed by advancing and retracting the probe tip repeatedly at different depths within the disc. Intradiscal implants may be inserted independently using separate instrumentation or along, through, or around probe 20 . Suitable implants include, among others, those disclosed in U.S. patent application Ser. No. 09/642,450 filed Aug. 18, 2000 entitled Devices and Methods of Vertebral Disc Augmentation, the disclosure of which is incorporated in its entirety herein by reference.
FIGS. 7, 8 , 9 , and 10 depict an embodiment of the device 10 placed within an anulotomy or defect of anulus 300 , which can be used to measure the thickness of anulus 310 . In FIG. 7, the distal portion of the cannula 30 defined by the intradiscal tip 50 is inserted through the anulotomy or defect 300 to a depth wherein the probe 20 is inserted just beyond the anterior border of the posterior anulus 310 . In FIG. 8, the probe member 20 is advanced out of cannula 30 and deflected by the deflection surface in curved passage 60 of the intradiscal tip 50 at an angle nearly perpendicular to device 10 , causing the probe member 20 to advance parallel to the inner surface of the posterior anulus 310 . In this use, the probe 20 need only be advanced outward several millimeters.
In FIG. 9, device 10 is proximally retracted from the anulotomy 300 until the probe 20 contacts the posterior anulus 310 . In FIG. 10, a slideably adjustable depth stop 70 is carried by the cannula 30 and advanced distally (anteriorly) until it contacts the exterior surface of the posterior anulus 310 and the probe member 20 is in contact with the interior surface of the posterior anulus 310 . The depth stop 70 functions by abutting anular tissue or surfaces of the vertebral body adjacent to the anulotomy 300 which impede further entry of the cannula 30 into the disc, such as may be determined by tactile feedback or under fluoroscopic visualization. FIG. 4 shows the depth stop adjustment knob 105 , calibrated measurement marks 100 and depth stop 70 . The cannula 30 or depth stop 70 may be marked with calibrated measurements 100 so that the distance between the intradiscal tip 50 at the point where the probe member 20 exits and the depth stop 70 , can be determined. This distance corresponds to the thickness of the anulus adjacent to the anulotomy 300 .
FIG. 18 depicts an embodiment of the device 10 placed within an anulotomy or defect in anulus 300 and being used to determine the anterior-posterior dimension of the nuclear space as defined by the distance between the inner surfaces of the posterior anulus and the anterior anulus. Here, the probe member 20 and the adjustable depth stop 70 are fully retracted. The probe 20 and advancer 40 may be eliminated entirely in an embodiment intended solely for the anterior-posterior measurement described herein. The intradiscal tip 50 of the device 10 is advanced through the anulotomy or defect in anulus 300 until the inner surface of the anterior anulus is reached and impedes further travel of the intradiscal tip 50 . In this manner the device 10 is used to provide tactile feedback of the disc's internal geometry. The adjustable depth stop 70 is then advanced distally toward the proximal exterior surface of the anulus or vertebral body and reading of the maximum depth reached can be obtained via calibrations on the proximal end of the device such as on the cannula. Electronic or other means could also be employed to measure and display this distance. The posterior anular thickness value can be subtracted from this to yield the distance between the inner aspects of the posterior and anterior anulus.
FIGS. 19 and 20 depict an embodiment of the device 10 placed within an anulotomy or defect in anulus 300 and being used to determine the distance between the left and right lateral interior surfaces of the anulus. In measuring the distance between the left and right lateral surfaces of the anulus 310 the intradiscal tip 50 is inserted just beyond the interior wall of the posterior anulus, the probe tip 80 is advanced out of the curved passage 60 in the plane of the disc, i.e. parallel to the endplates, until tactile feedback from the advancer 40 , indicates that lateral surface is resisting further advancement. Calibrated makings on the advancer 40 visible through or proximal to the cannula can then be used to determine this distance.
By rotating the device 10 , while the probe member 20 is fully retracted, 180 degrees and performing the same action in the lateral direction, as shown in FIG. 20, one can obtain the total distance between the interior lateral surfaces. This method may be repeated at various depths within the disc by adjusting the depth stop 70 . A similar method of using the probe member 20 to tactically interrogate the interior of the disc may be employed to dimension the distance between the vertebral endplates and relative distances from the anulotomy 300 to the endplates. All of the foregoing measurements may be taken either using a scoop shaped distal tip as shown, or a blunt, atraumatic tip without a scoop to minimize disruption of the nucleus.
Depth stop 70 may also be used to coordinate the dissection or resection of a space within the disc with the placement of another intradiscal instrument or implant. This method may be particularly useful for placing an implant along an inner surface of the anulus fibrosus. The thickness of the anulus as determined by any of the measurement techniques described above may be used for setting depth stops on other implantation instruments used to place an implant along the anulus. As an example, if the posterior anulus is measured to be 7 mm thick using device 10 , a depth stop may be set on an implantation instrument to limit the penetration of this instrument into the disc to 7 mm or another depth that is relative to 7 mm. This would allow for an implant placed by this instrument to be inserted into a space previously dissected within the disc by device 10 along the inner surface of the posterior anulus.
Probe 20 may be used as part of the placement of an intradiscal implant in any of a variety of ways. One advantageous use of the probe 20 can be achieved by detaching it from advancer 40 once probe 20 is in a desired position within the disc space. Implants may then be passed along, behind or in front of probe 20 into this desired position. Probe 20 may then be removed from the disc space.
The measurement techniques described above may also be used to achieve the complete resection of the nucleus from the disc space. For example, a resection or ablation tip as described above may be passed repeatedly into the disc to the lateral borders of the nucleus. This process may be repeated at varying depths within the disc from the inner aspect of the posterior anulus to the inner aspect of the anterior anulus as determined by the depth stop.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | The present invention relates generally to intervertebral disc devices and methods and instrumentation for intervertebral disc procedures. An intervertebral disc repair and diagnostic device that is minimally invasive, actively guided, and provides direct and consistent access to the inner surface of the posterior anulus, which will not unintentionally exit the posterior anulus and cause harm to the spinal cord, is provided. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a national stage of PCT/EP2004/000349 filed Jan. 19, 2004 and based upon DE 103 03 013.1 filed Jan. 27, 2003 under the International Convention.
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates to a vehicle with at least one catadioptric camera fitted on the vehicle. The camera is one in which at least one curved mirror arranged on the optical axis of the camera is used as an imaging element. The camera allows panoramic viewing in directions transverse to the optical axis, with an azimuth angle of up to 360° with respect to the latter. According to the invention, the catadioptric camera is preferably used to monitor the space at the back and front of the vehicle.
2. Related Art of the Invention
Along the optical axis, the field of view of a catadioptric camera is bounded in both directions by conical blind regions. The field of view boundary of such a cone, or its semivertex angle, is dictated by the configuration of the camera itself, for instance the spatial extend and arrangement of the imaging elements.
EP 1 197 937 A1 relates to a spatial monitoring system for a vehicle, which comprises a catadioptric camera with an optical axis oriented vertically. EP 1 158 473 A2 also relates to such a spatial monitoring system.
Since the blind regions of a catadioptric camera cannot be made arbitrarily small, there are regions in the immediate vicinity of the vehicle which cannot be seen by these known spatial monitoring systems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a vehicle which has at least one catadioptric camera fitted on the vehicle, and which ensures improved spatial monitoring.
Accordingly, the invention relates to a vehicle with at least one catadioptric camera fitted on the vehicle, which has an optical axis and at least a first mirror arranged on the optical axis. The optical axis is inclined with respect to a vertical. This has the advantage that the camera can also observe spatial regions in the immediate vicinity of the vehicle, in particular road surfaces, which would lie in the blind regions of the camera if its optical axis was arranged vertically. The oblique setting is preferably selected so that the vehicle completely fills up one of the blind regions.
If the optical axis of the catadioptric camera is inclined by an angle α with respect to a vertical, and the cone forming an upper blind region has a semivertex angle β, and then it is preferable for the angles α and β to satisfy the following inequality: β<90°−α. This ensures that the field of view of the camera always comprises a horizontal, so that even distant objects can be detected in the direction of this horizontal.
The semivertex angle of the cone forming the second blind region, or lower blind region, is denoted by χ. This blind region is generally filled at least partially by the vehicle itself. According to the invention, this semivertex angle χ is preferably greater than the angle α. This prevents the camera from detecting unnecessarily large areas of the vehicle which are generally not of interest to be observed.
Preferably, the angles χ and α satisfy the following inequality: χ<α+30°. This ensures on the one hand that the field of view of the camera is directed far downward so that, for example, the fenders of the vehicle lie in the field of view of the camera, but on the other hand, as already mentioned above, unnecessarily large areas of the vehicle such as front or rear surfaces are not also detected.
A catadioptric camera is preferably mounted on the nose and/or the rear of the vehicle. This makes it possible to monitor the space at the back and front of the vehicle. This is important especially when parking the vehicle. The catadioptric camera may in this case be mounted on the engine hood, on the trunk door, on the fenders or on the bodywork above the fenders.
If the angles α, β and χ are selected as indicated, then both the fender of the vehicle and a horizontal lie in the field of view of the catadioptric camera, which is mounted on the nose or rear of the vehicle. This allows optimal monitoring of the environment of a vehicle, especially when the space in front of or behind the vehicle needs to be monitored for parking.
Nevertheless, if a lateral environment of the vehicle is intended to be monitored, it is also possible to fit the catadioptric camera on the side bodywork of the vehicle or, for example, to integrate it in the exterior rear view mirrors.
The vehicle preferably has a device for retracting and deploying the catadioptric camera.
In the vehicle according to the invention, the catadioptric camera preferably has a second mirror, which is arranged opposite the first mirror on the optical axis. Such a catadioptric camera with two mirror surfaces is described, for example, in WO 00/41024.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be explained in more detail by way of example with reference to the following figures, in which:
FIG. 1 shows a schematic side of view of an embodiment of the vehicle 1 according to the invention;
FIG. 2 shows a schematic plan view of the vehicle 1 according to FIG. 1 ;
FIG. 3 shows a sketch of one configuration of a catadioptric camera 2 ;
FIG. 4 shows a sketch of another configuration of a catadioptric camera 2 ;
FIG. 5 shows a sketch to explain the field of view of the rear catadioptric camera 2 in FIGS. 1 and 2 .
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 shows a side view and a plan view of a configuration of a vehicle 1 according to the invention, with an engine hood 3 , a trunk door 4 and fenders 15 . The vehicle 1 has two catadioptric cameras 2 . One of the cameras 2 is mounted on the engine hood 3 of the vehicle, and the other camera 2 is mounted on the trunk door 4 of the vehicle, both in a position near the edge. The cameras may, however, also be fitted on the fenders 15 . The cameras 2 respectively have an optical axis 5 . The pictures delivered by the cameras 2 are processed, and an image resulting from this is provided to the driver of the vehicle 1 via a screen device (not shown). The pictures delivered by the cameras 2 may, however, also be used to automatically determine the distance of the vehicle 1 from neighboring vehicles or obstacles, for example with the aid of a suitably programmed microprocessor.
The vehicle 1 furthermore has devices (not shown) for retracting and deploying the camera 2 . When the cameras 2 are not needed, they can be fully retracted so that they no longer protrude from the surfaces of the engine hood 3 and the trunk door 4 . By using a cover (not shown), the cameras 2 in the retracted state are protected from the effects of dirt and weather. Retractability of the cameras 2 also has the advantage that they are protected from the airflow when the vehicle 1 is driving at a substantial speed. In the retracted state, they furthermore do not impair the esthetic appearance of the vehicle 1 . When the cameras 2 are needed, for example as an aid to parking, they can be deployed with the aid of the aforementioned device.
FIGS. 3 and 4 show sectional views of two configurations of catadioptric cameras 2 , which the vehicle according to the invention may have. On the optical axis 5 of each camera 2 , there is at least a first mirror 6 . The first mirror 6 has a hyperboloid mirror surface. Nevertheless, it may also be a spherical, ellipsoid or paraboloid mirror surface. The reference numeral 7 denotes a lens 7 . The camera 2 shown in FIG. 4 also has a further, second mirror 8 which lies opposite the first mirror 6 on the optical axis 5 . The mirror 8 likewise has a hyperboloid mirror surface. Nevertheless, it may also be an ellipsoid, paraboloid or planar mirror surface. The lens 7 is inserted into a central bore of this mirror 8 . The field of view detected by the camera 2 is imaged on an image plane 11 . A highly distorted perspective image is thereby obtained. The distortions are corrected computationally, for example with the aid of a microprocessor (not shown) in order to obtain an image which reproduces the environment detected around the vehicle as freely as possible from distortion and which, when displayed on a screen, allows the driver of the vehicle to intuitively assess the environment.
FIG. 5 shows a sketch which explains the field of view of the rear catadioptric camera 2 . The optical axis 5 of the camera 2 is inclined by an angle α with respect to a vertical 9 , which is represented by dashes. The reference numeral 10 denotes a horizontal. The field of view of the catadioptric camera 2 , represented by shading in the Fig., is bounded upward by a first, upper cone 12 lying on the optical axis 5 . It has a semivertex angle β. The angles α and β satisfy the following inequality: β<90°−α. This ensures that the field of view of the camera 2 always includes the horizontal 10 . Downward, the field of view of the camera 2 is bounded by a second, lower cone 13 . It has a semivertex angle χ. This semivertex angle χ need not be less than the angle α , since χ=α would correspond to the case in which the camera can look vertically downward. In most practically relevant installation situations, moreover, parts of the vehicle which it is not of interest to observe lie vertically below the camera. On the other hand, χ should also not be greater than α+30°. This means that the field of view of the camera reaches down so steeply that the fender 15 still lies in it, and objects on the road can still be detected even at a short distance from the fender 15 of the vehicle 1 .
In the azimuth direction, the field of view of the camera 2 extends over an angle δ of 360°, although it may also be interrupted on the side facing the vehicle, the left-hand side in FIG. 5 , without significantly compromising the effectiveness of the camera. | The invention relates to a vehicle ( 1 ) comprising at least one catadioptric camera ( 2 ), which is mounted on the vehicle and which has an optical axis ( 5 ) and at least one first mirror ( 6 ) that is arranged on the optical axis. The optical axis ( 5 ) of the camera ( 2 ) is slanted relative to a vertical ( 9 ). | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for controlling the mass flow rate of vapor in a carrier gas.
2. Description of the Prior Art
In certain vapor-phase chemical processes, such as are encountered in the manufacture of semi-conductors, it is necessary to precisely meter the input mass flow rate of liquid chemicals as minor vapor-phase constituents of a flowing gaseous atmosphere.
In a typical system for the manufacture of semi-conductors a carrier gas such as hydrogen is introduced into a vaporizer where it is passed over or through a liquid source such as silicon tetrachloride to pick up vapor for discharge into a reaction chamber in which a portion of the vapor material is deposited upon a semi-conductor wafer or the like. The mass flow rate of the silicon tetrachloride vapor must be very accurately controlled in order to deposit a precise thickness of the vapor material on the wafer.
Regulation of vapor mass flow rate is accomplished in the prior art in various ways. In one system the temperature and pressure of the liquid in the vaporizer, and the flow of carrier gas through the vaporizer, are closely regulated to maintain constant the amount of vapor taken up by the carrier gas. This system is difficult to control because of variations which are present in the degree of saturation of the vapor in the carrier gas.
Another prior art vapor feed regulation system measures the ratio of vapor to carrier gas as the mixture leaves the vaporizer. This is done by thermal conductivity analysis, the flow rate of carrier gas being controlled to yield the desired vapor feed rate, as determined by the analysis. This type of system is limited by the accuracy of the thermal conductivity analysis, and the vapor is typically undesirably exposed to contamination from the heated conductivity cells which characterize the analysis. Typical of this type of prior art system is that which is disclosed and claimed in U.S. Pat. No. 3,650,151, issued Mar. 21, 1972 for FLUID FLOW MEASURING SYSTEM.
Yet another system of the prior art involves metering the rate of flow of the liquid source to a flash vaporizer where it is vaporized in a carrier gas stream. This system does not work well for extremely low flow rates, and particularly where chemicals are involved which are corrosive. The metering is imprecise and subject to contamination under these conditions.
SUMMARY OF THE INVENTION
According to the present invention, a system is provided for detecting the mass ratio of vapor to a carrier gas. The system is characterized by precise regulation of both carrier gas flow rate and vapor flow rate, and extreme purity of the resultant fluid mixture by avoidance of exposure of the vapor to temperatures above ambient or to materials other than quartz or the like.
The present system includes a mass flow controller for regulating the flow of carrier gas, and a vaporizer for introducing vapor into a portion of the carrier gas to provide a fluid mixture. This mixture is diluted by mixing with the balance of the regulating flow of carrier gas. The resultant mixture is applied to a detection means which generates a detector signal which varies according to the mass ratio of the vapor to the carrier gas. The detector signal is applied to a controller which generates a control signal varying in accordance with variations in the detector signal.
The control signal from the controller adjusts the operation of the modulating means which controls the portion of the carrier flow bypassing the vaporizer. Depending upon the mass of the vapor constituent of the fluid mixture from the vaporizer, the proportion of diluent carrier gas is increased or decreased until a predetermined constant mass ratio is achieved.
In one embodiment detection of the mass ratio of vapor to carrier gas is achieved through the use of a dew point cell. For a predetermined desired constant mass ratio of vapor to carrier gas, incipient condensation will occur in the cell at a given pressure and temperature. The dew point cell temperature is therefore adjusted at a predetermined "set point" at which incipient condensation will occur at the desired constant mass ratio of vapor to carrier gas.
Other objects and features of the present invention will become apparent from consideration of the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic view of the system of the present invention: and
FIG. 2 is a schematic view of the controller and dew point detection portions of the system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present system 10 is adapted for detecting the mass ratio of vapor to a carrier gas and comprises, generally, a flow control means 12 into which the carrier gas enters at 14 from any suitable source. The flow control means 12 is operative to regulate the mass flow rate of carrier gas to the remainder of the system.
The carrier gas flow from the flow control means 12 is divided into two paths, one flowing to a vaporizer 16 through an inlet conduit 18, the other through a bypass conduit 20 to a modulating means 22. The means 22 includes a valve under the electromagnetic control of a solenoid 24 or the like for controlling operation of the valve in response to certain control signals, as will be seen. Adjustment of the modulating means 22 in response to such control signals determines the amount of carrier gas flowing through the means 22 and bypassing the vaporizer 16.
It is possible for the valve of the modulating means 22 to be a three-way modulating valve in which the flow is divided between conduits 18 and 20. It could also be a single valve in either the conduit 18 or the conduit 20, with a restriction in the other conduit. In the embodiment illustrated, the valve is shown as a single valve in the bypass line 20, with a suitable flow restriction 26 being shown in the conduit 18.
The flow restriction 26 is required only to give the modulating means 22 sufficient pressure drop to maintain control. Depending upon the pressure drop characteristics of the vaporizer 16 and the associated conduits, restriction 26 may optimally be a pressure-relief valve or the like, a fixed restriction, or might be eliminated.
Carrier gas flowing into the vaporizer 16 picks up vapor from the liquid source in the vaporizer 16 and the resulting fluid mixture passes through a discharge conduit 28 to a mixer 30.
The bypass or diluent carrier gas from the modulating means 22 also passes to the mixer 30, through a conduit 31, and the two streams are recombined, mixed and passed through a dew point cell 32. The cell 32 is adapted to sense the dew point of the fluid mixture at a dew point temperature for which the cell 32 is adjusted. As will be apparent to those skilled in the art, assuming a constant discharge or atmospheric pressure and a constant temperature in the cell 32, the detector signal generated by the cell 32 will indicate incipient condensation in the cell corresponding to a particular or predetermined constant mass ratio of vapor to carrier gas in the fluid mixture passing from the cell 32 to a discharge conduit 34. As will be seen, the system is operative to maintain such a predetermined constant mass ratio automatically by modulating operation of the means 22.
Detector signals from the cell 32 are indicated diagramatically as passing through electrical leads 35 and 47 to a controller 36 electrically coupled to the means 22 and the flow control means 12 by electrical leads 38 and 40, respectively.
Once the predetermined constant mass ratio of vapor to carrier gas is established by the control signals applied to the modulating means 22, control signals applied to the flow control means 12 through the lead 40 are operative to provide a range of regulated total mass feed rates to the discharge conduit 34.
With particular reference to the individual components constituting the present system 10, the flow control means 12 may comprise an inexpensive manual control such as a rotameter/needle-valve assembly or a mechanical pressure regulator/needle-valve type. However, it preferably comprises a valve, a flow sensor, feedback control circuit and an associated proportional solenoid or the like so that the valve can be electronically controlled remotely by a controller such as the controller 36. Since the flow control means 12 must regulate the total carrier gas flow it should be operative over a relatively wide control range. Various suitable flow control means for this purpose are commercially available, as will be apparent to those skilled in the art.
The modulating valve 22, like the flow control means 12, preferably comprises a valve adapted to be remotely controlled by control signals acting upon an associated proportional-solenoid 24. Any valve arrangement would be suitable so long as it is operative to control the division of flow between the vaporizer via conduit 18 and bypass via conduit 20 in response to control signals from a controller such as the controller 36.
The particular construction of the vaporizer 16 is not a part of the present invention. It is simply a container for solid or liquid chemicals such as liquid silicon tetrachloride. The vaporizer 16 may be any of various commercially available units operative to pass carrier gas over or through the contained material so that some of the material vaporizes or sublimes for discharge through the conduit 28 to the mixer 30.
The confluence of the conduits 28 and 31 may provide sufficient turbulence for adequate mixing, but the mixer 30 is preferably provided to insure against stratification of the streams passing to dew point cell 32. The streams should be thoroughly mixed to avoid any sensing by the dew point cell 32 of non-representative fluid mixture samples.
Various suitable mixers for this purpose are commercially available, and selection of the proper mixer will depend upon the particular liquid and carrier gas involved, as well as other circumstances such as producibility and cost, required pressure drop for adequate mixing, internal volume and surface area, and cleanability. The mixer can include a moving element such as an impeller or the like, but a motionless type is preferred. A suitable motionless mixer could be of the type characterized by flow passage shapes resulting in mixing by turbulence, velocity differences, or the like. Known types include screens or perforated plates arranged transversely of the flow path; an ejector system in which one stream is introduced into the other at high relative velocity; butterfly baffles in the form of short twisted vanes dividing the flow stream and introducing swirl in opposite directions sequentially; and jumbled short tubes oriented randomly in the path of fluid flow to produce a criss-crossing, sheared flow.
The mixer 30 need not be a separate element, as schematically shown in FIG. 1. It could be integrated with a conduit juncture or the dew point cell 32.
The dew point cell 32 is a preferred means for determining the mass ratio of vapor to carrier gas in the stream discharged from the mixer 30. The cell 32 is particularly effective by reason of its operation on the principle that the concentration of a binary mixture of a vapor and a gas at a given pressure has a unique value for a given dew point. Thus, if the dew point is known, the mass ratio of vapor to carrier gas is also known. It has the further advantage that its operating conditions are inherently related to the vaporizer conditions; i.e. the temperature-pressure-concentration conditions for the vaporizer operation and dew point detector operation will be similar. This similarity permits a wider range of source material vapor pressures to be accommodated so that diverse vapor-carrier combinations can be accommodated without changing the detector type. In selecting a suitable dew point cell from the commercially available types, certain characteristics are desirable.
The cell 32 should be operated at dew point temperatures lower than the ambient temperature. Otherwise, undesirable condensation might occur on the conduits or other elements of the system through which the fluid mixture passes. This would adversely affect the accuracy of sensing by the cell 32. Of course, the temperature in the vaporizer 16 and the selected dew point of the mixture must also be at or below ambient temperature in the typical commercial processes for which the present system is designed. The effective ambient temperature can, of course, be increased by heat tracing or by enclosing all critical portions of the system in an oven.
The cell 32 should be selected for operation over a relatively wide range of flow rates to take advantage of the full flow range of the flow control means 12. That is, once fluid flow from the cell 32 is regulated at a constant mass flow ratio of vapor to carrier gas, the cell 32 should be capable of providing higher and lower rates of flow at that particular dew point, within the range of the flow control means 12.
The material of the interior envelope of the dew point cell 32 is preferably pure fused quartz to provide corrosion and contamination protection. In addition, the internal envelope should have a minimal internal volume and surface area for sensitivity to relatively low mass flow rates. Other desirable characteristics will suggest themselves to those skilled in the art, having in mind the particular application at hand.
With reference to FIG. 2, there is illustrated a dew point cell 32 which is representative of one form of a cell capable of generating appropriate detector signals for application to the controller 36.
A conventional light-emitting diode or LED 42 energized by suitable supporting circuitry (not shown) angularly projects light on a thermoelectrically cooled sensing mirror 44 over which the fluid mixture sample is passed. Light reflected from the mirror 44 is sensed by a conventional photodetector or photocell 46 and converted into a detector signal which is applied through the lead 47 to an amplifier 48, the detector signal varying as a function of the amount of vapor condensation on the mirror 44. The amplifier 48 forms a part of the controller 36.
Although the dew point is sensed optically in the illustrated cell 32, other systems are available for sensing dew point, such as by capacitance, and the present system comprehends such variations.
The intensity of reflected light to the photocell 46 changes according to the degree of condensation on the mirror 44. Occurrence of incipient condensation is adjustable by controlling the temperature of the mirror 44, as sensed by a thermistor, platinum resistance thermometer, or the like (not shown) located on the mirror 44. Temperature control is by means of suitable thermoelectric cooling means 50 connected between the mirror 44 and a heat sink 52.
Signals from the photocell 46 are applied by a lead 47 to an amplifier 48 forming part of the controller 36.
Electrical signals from the temperature transducer on the mirror 44 are applied to an amplifier 56 through the lead 35 and, depending upon the command signal or setting provided by a schedule 37, the amplifier 56 responds through an electrical lead 54 to operate the cooling means 50 to achieve a predetermined mirror temperature.
The controller 36 may take any form suitable to perform the functions herein indicated, as will be apparent to those skilled in the art, the particular embodiment described being merely exemplary.
The controller 36 includes an internal adjustment means 58 of a variable voltage or resistance type to establish the "set point" for the amplifier 38. Deviation from the set point effects generation of an opening or a closing signal by the amplifier 48 by application to the modulating means 22. The amplifier 48 compares the detector signal applied to it through lead 47 with the set point signal coming from the internal adjustment means 58 and, if the mirror 44 indicates excessive condensation, the valve 22 is caused to modulate towards open to dilute the fluid mixture coming from the mixer 30. If the mirror 44 indicates little or no condensation, the signal from the amplifier 48 causes the valve 22 to modulate towards closed and thereby increase the proportion of carrier gas passing through vaporizer 16.
The particular construction of the components of the controller 36 do not form a part of the present invention and the brief description herein made is intended primarily to guide those skilled in the art in recognizing the characteristics of the component which are important to a selection of suitable components.
The selection of an amplifier 48 should be made having in mind that there are likely to be system lags due to plumbing transport delay, that is, a delay in the flow of the carrier gas and fluid mixture through the various conduits and components of the system. Also there will be probable lags resulting from the dynamics of the dew point cell. Consequently, amplifier 48 should be dynamically compensated to provide stable performance under these circumstances, as by incorporation of suitable capacitors, as will be apparent. The capacitance values should be selected to maximize the gain of the system, while reducing settling time and accumulated control error following upsets. The purpose of this control loop remains to develop a vapor/gas mixture having a dew point temperature equal to that of the mirror 44.
The selection of the amplifier 56 depends upon similar considerations. It is a relatively simple temperature controller with an electronically commanded set point provided by the "schedule" circuit. More particularly, the amplifier 56 compares the temperature of the mirror 44 with the set point command from the schedule circuit 37, such as by means of a suitable thermocouple, thermistor, or like signal, for energization of the thermoelectric cooler 50 such that the mirror temperature is controlled to the commanded value.
The schedule circuit 37 is also responsive to a command setting fed into it by a suitable vapor flow command 60, which establishes the total mass flow rates of carrier gas and vapor delivered by this system. Thus, the circuit 37 provides a combination of carrier gas flow rate and dew point temperature command signals to the flow control means 12 and amplifier 56, respectively.
A number of different schedules to accomplish the foregoing will immediately suggest themselves to those skilled in the art. For example, the carrier flow could be held constant by flow control 12 and the dew point temperature varied to change the regulated vapor carrier ratio to give the desired vapor flow rate. The command provided by the schedule 37 to amplifier 56 should for convenience be linearly related to the mass ratio of vapor to carrier, and thereby to the mass flow rate of the vapor from the dew point cell 32. Since the dew point temperature is a nonlinear function of the ratio of vapor to carrier gas, a nonlinear dew point temperature signal provided by a circuit such as a thermistor circuit could be used for appropriate linearization. In addition, this command signal could be corrected for absolute pressure, if required by the particular application.
Alternatively, the dew point temperature, and therefore the vapor-carrier ratio, could be held constant by fixed set points in amplifiers 48 and 56, while the flow through flow control 12 is varied to give the desired delivery rate of both vapor and carrier flows at this fixed ratio.
As a third schedule possibility, both flow through control 12 and dew point could be varied to give the widest possible adjustment range of vapor feed rate.
Regardless of the command schedule used, in operation, the carrier gas passes through the flow control means 12 to the modulating means 22, and to the vaporizer 16. The vaporized liquid from the vaporizer 16 is then carried by the carrier gas to the mixer 30, where it is mixed with carrier gas coming from the modulating means 22.
The mixture passes through the dew point cell 32 for discharge into the reactor (not shown) by means of the conduit 34. In passing through the cell 32 a detector signal is generated by the photocell 46 which is compared in the amplifier 48 with the signal developed by the set point command provided by the internal adjustment means 58. This yields a control signal from the amplifier 48 which opens or closes the valve of the modulating means 22 until the predetermined amount of condensation exists on the mirror 44 to correspond with the desired dew point temperature.
The consequence of the foregong operation is very accurate regulation of mass ratio of vapor to carrier gas, and also regulation of the absolute mass flow rate of both vapor and carrier gas.
In the event that it is desired to control only the ratio of vapor to carrier, then the flow control means 12, which controls the carrier flow rate, can be deleted. This does not interfere with operation of the modulating means 22 and therefore that control loop still controls the ratio of vapor to carrier.
Although the foregoing description has been particularly directed to an application in which carrier gas picks up vapor from a liquid source in a vaporizer, it is also applicable to a carrier gas acting upon a sublimed solid, and the terminology used is to be construed as comprehending such a sublimed solid. Thus, terms such as "condensation" are to be interpreted to include desublimation, and are not to be limited to the phase changes characteristic of liquids.
Moreover, although the use of the dew point cell 32 in the present system is believed to be unique, it is contemplated that other means may be utilized which operate to generate a detector signal correponding to deviations from a predetermined condition such as incipient condensation or the like. Since the detection device senses incipiency of condensation, or, more generally, the proximity of the vapor phase to a phase change condition, it need not be a dew point cell. More particularly, a binary mixture of vapor in carrier gas, wherein the vapor would change phase if its concentration were sufficiently high, that is, if its partial pressure equalled the total pressure of the mixture, has a "critical" condition wherein its phase change is incipient. This critical condition is characterized by the following independent parameters:
(1) Vapor/carrier mass ratio;
(2) Temperature; and
(3) Pressure.
Since there are no other significant independent variables, the detector device is most generally described in terms of these independent variables and without definition of the dependent variable observed or the detection mechanism used to transduce it.
Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention. | The invention is a system for controlling the mass flow rates of vapor and carrier gas in a flowing fluid mixture. A regulated flow of carrier gas is divided so that a fraction of the flow passes through a vaporizer to pick up the vapor while the balance bypasses the vaporizer. The streams are then recombined and the resulting mixture is passed through a dew point detector which gives an output signal which varies according to variations in the mass ratio of the vapor to the carrier gas. A controller responds to the detector signal to generate a control signal which modulates a valve to vary the fraction of the carrier gas passing through the vaporizer, thereby influencing the mass rate at which the vapor is introduced. The feedback control from the dew point detector to the valve is adapted to regulate the dew point, and thereby the mass ratio of vapor to carrier. Since carrier mass flow rate is separately regulated, the regulation of the mass fraction of vapor in the blend results in the regulation of vapor mass flow rate as well. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to the field of techniques and systems for controlling traffic and more particularly to a system for switching an automatic traffic control system to a manual mode and automatically switching back to an automatic mode after a period of inactivity.
BACKGROUND OF THE INVENTION
[0002] We see traffic control systems at many road intersections. In the United States, the acceptable traffic control system is a traffic light system for each intersection direction having a red, yellow and green indicator (light) The green indicates the traffic in that direction can proceed through the intersection. The yellow indicates that the traffic light is transitioning between green and red and traffic should prepare to stop. The red indicates the traffic in that direction should stop. In some systems, multiple sets of lights are configured in a given direction with some dedicated to traffic in turn lanes.
[0003] The traffic control system has timers that are programmed to control the duration of each signal depending upon the average traffic levels and the amount of time required to move across an intersection, etc. Some traffic control systems are coupled to one or more nearby traffic control systems to provide synchronization between multiple traffic control systems to aid in the efficient flow of traffic. Additionally, some traffic control systems are capable of being centrally controlled by an operator, whereby an operator is provided with tools to change timing, etc., to improve traffic flow.
[0004] During unusual traffic patterns such as when an event begins or is finished, often the traffic control system is manually operated by a police officer. In such, the police officer access the control box (unlocks and opens a door) of the traffic control system and switches the traffic control system from automatic to manual. From there, the police officer changes the state of the traffic control system by operating a manual control. When finished, the police officer switches the traffic control system back into automatic mode and closes/locks the traffic control system door. Unfortunately, there are circumstances where the police officer must leave in an emergency. In such, if the police officer forgets to switch the traffic control system back to automatic mode, the traffic control system will remain green in one direction and red in the other direction, causing a major traffic problem.
[0005] What is needed is a traffic control system that will revert to an automatic mode when left unattended in a manual mode.
SUMMARY OF THE INVENTION
[0006] In one embodiment, a traffic control system is disclosed including an enclosure for containing the traffic control system that has an access door with a lock for controlling access to the enclosure through the access door. The traffic control system has an automatic mode of operation and a manual mode of operation, whereas the traffic control system automatically transitions a state of a plurality of traffic lights when in the automatic mode of operation and cycles the state of the plurality of traffic lights in response to a change signal when in the manual mode of operation. An automatic mode activation switch is housed within the enclosure. Activation of the automatic mode activation switch changes the state of the traffic control system from the automatic mode of operation into the manual mode of operation. A watchdog timer is coupled to the traffic control system, The watchdog timer is reset when the automatic mode activation switch is operated and in response to the change signal. If the watchdog timer expires, the traffic control system switches to the automatic mode of operation.
[0007] In another embodiment, a method of controlling traffic is disclosed including unlocking an enclosure of a traffic control system and changing an operating mode of the traffic control system from an automatic mode of operation to a manual mode of operation. The changing of the operating mode of the traffic control system also starts a watchdog timer. A traffic control device connected to the traffic control system is operated to cycle a plurality of traffic lights, said operation of the traffic control device also resets the watchdog timer. If the watchdog timer expires, the mode of operation of the traffic control system is changed from the manual mode of operation back into the automatic mode of operation.
[0008] In another embodiment, a traffic control system is disclosed including an enclosure for containing the traffic control system with an access door and a lock controlling access to the enclosure through the access door. The traffic control system has an automatic mode of operation and a manual mode of operation, whereas the traffic control system automatically cycles the state of traffic lights when in the automatic mode of operation and cycles the state of the traffic lights in response to a change signal when in the manual mode of operation. An activation device within the enclosure changes the traffic control system into the manual mode. A watchdog timer is reset both when the automatic mode activation switch is operated and in response to the change signal. A wireless transmitter transmits a wireless change signal in response to pressing of a control on the wireless transmitter. A wireless receiver coupled to the traffic control system receives the wireless change signal and, in response, sends the change signal to the traffic control system and resets the watchdog timer. If the watchdog timer expires, the traffic control system switches back to the automatic mode of operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:
[0010] FIG. 1 illustrates a perspective view of a system of a first embodiment of the present invention.
[0011] FIG. 2 illustrates a schematic view of a system of the present invention.
[0012] FIG. 2A illustrates a schematic view of a timing diagram of the system of the present invention.
[0013] FIG. 3 illustrates a block diagram of the present invention.
[0014] FIG. 4 illustrates a block diagram of a computer system of an alternate embodiment of the present invention.
[0015] FIG. 5 illustrates a flow chart of the prior art.
[0016] FIG. 6 illustrates a first flow chart of the alternate embodiment of the present invention.
[0017] FIG. 7 illustrates a second flow chart of the prior art.
[0018] FIG. 8 illustrates a second flow chart of the alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.
[0020] Referring to FIG. 1 , a perspective view of a system of a first embodiment of the present invention is shown. In this example, a police officer holds a wireless remote control 70 for a traffic control system 10 . Although the present invention works equally as well with a traffic control system that has a tethered (wired) hand control, the present invention is intended for traffic control systems that have a wireless hand control 70 (as shown). The main reason for such is that since the police officer may be operating the traffic control system 10 from a distance, perhaps across the street, if the officer should receive an emergency call, the officer may forget or explicitly decide to abandon the traffic control system 10 , leaving it in its manual mode until returning later. By doing such, major traffic problems will arise.
[0021] FIG. 1 shows an exemplary traffic control system with multi-colored traffic control lights 82 , the traffic control box 10 with an access door 94 that has a lock 92 shown with keys 96 present. In this example, an antenna 73 provides for receipt of wireless manual control signals from the antenna 71 of the hand held traffic control transmitter 70 . The locking access door 94 provides a level of security so an unauthorized person would have difficulty accessing the traffic control system 10 .
[0022] Referring to FIG. 2 , a schematic view of a system of the present invention is shown. In this embodiment, an industry standard 555 timer 50 is employed to generate a watchdog timer period (T 1 ). The circuit of FIG. 2 is an astable multivibrator whose watch dog timer period is determined by R 1 52 , R 2 54 and C 1 58 . The cycle begins when the manual mode push button switch 64 is depressed. This action triggers the 555 timer 50 (pin 2 ) causing the output (pin 3 ) to go high as shown in the timing diagram FIG. 2A . The output of the 555 timer 50 is an input to an AND gate 74 . When the output of the 555 timer is high, the AND gate 74 permits traffic control signals from the wireless receiver 72 to pass to the traffic control system. Additionally, it enables manual mode operation of the traffic control system.
[0023] Now, R 1 52 charges C 1 58 through diode D 1 56 until the voltage across C 1 58 reaches a threshold at pin 6 of the 555 timer 50 . At that point, the output of the 555 timer 50 goes low, thereby disabling the manual mode and preventing further wireless control signals from passing to the signal control. The watchdog time period (T 1 ) is determined by the values of R 2 54 and C 1 58 . The time period (T 1 ) is approximately 0.69(R 1 +R 2 )*C 1 . The trigger input and output signal of the 555 timer 50 is shown on oscilloscope screen 80 of FIG. 2A . For example, using a 1.8M resistor for R 1 52 , a 15K resistor for R 2 54 and a 1000 uf capacitor for C 1 56 yields a time period (T 1 ) of approximately 20 minutes.
[0024] If a wireless signal is received from the antenna 71 of the wireless transmitter 70 at the antenna 73 of the wireless receiver 72 before the watchdog timer expires, the wireless signal resets the timing capacitor C 1 58 , thereby restarting the watchdog timer period. In this way, as long as a signal is received periodically (e.g., the police officer is actively controlling the traffic control system 10 ), the watchdog timer is repeatedly reset and doesn't expire.
[0025] Alternately, the alternate tethered signal change control includes a wired pushbutton switch 65 used to control the cycling of the traffic lights and to reset the watchdog timer.
[0026] A pull-up resistor R 3 62 biases the trigger to a positive voltage until the wireless signal (or tethered signal) is received or until the push-button switch 64 is pressed.
[0027] Referring to FIG. 3 , a block diagram of the present invention is shown. In this embodiment, the traffic control system 10 has an access door 94 that is locked by a lock 92 that has a lock arm 90 that helps prevent the access door 94 from being opened without a key. Any type of lock known in the industry is anticipated. Once the access door 94 is open, the user (police officer) has access to the “Initiate Manual Control” push button switch 64 . Once pressed, the push button switch 64 signals the watch dog timer to start timing and to output a signal to enable manual control of the traffic controller 80 .
[0028] While in manual mode, the user periodically sends signals to control the traffic patterns. In this example, a wireless system is used, although a wired (tethered) system works equally as well. The wireless signal is sent from a hand-held wireless transmitter 70 with antenna 71 to a wireless receiver 72 that also has an antenna 73 . The change signal from the wireless receiver 72 does two things; it resets the watchdog timer 76 and, passing through the AND gate 74 , it manually controls the traffic controller 80 , changing the outputs of the traffic controller 80 and, hence, the lighted patterns on the traffic light 82 .
[0029] This embodiment operates slightly differently from that of FIG. 2 . That is, once the watchdog timer expires and the output of the watchdog timer goes low, all signals from the wireless receiver 72 are stopped by the AND gate 74 and, therefore, do not reset the watchdog timer after it expires. In this embodiment, once the watchdog timer expires, the user needs to press the “Initiate Manual Control” push button 64 to re-enter manual mode.
[0030] Referring to FIG. 4 , a block diagram of a computer system of an alternate embodiment of the present invention is shown. In this embodiment, the traffic signals 82 are controlled by a computer system. The computer system has a processor (CPU, controller, etc.) 110 with internal or external memory 120 and a system bus 130 for connecting stored program memory 140 and other peripherals. The processor 110 can be any processor or a group of processors, for example an Intel Pentium-4® CPU or the like. The memory 120 is connected to the processor and can be any memory suitable for connection with the selected processor 210 , such as SRAM, DRAM, SDRAM, RDRAM, DDR, DDR-2, etc. Firmware is stored in firmware storage 140 that is connected to the processor 110 and may include initialization software. The firmware storage 140 is any known persistent storage such as ROM, PROM, EPROM, EEPROM, FLASH, FERAM, etc.
[0031] Connected to the bus 130 are relay drivers 150 / 160 / 170 for controlling relays 155 / 165 / 175 that are used to illuminate the red, yellow and green lights of the traffic signal 82 . This is an example of one way for a computer system to control lights and other ways known in the industry are equally suited for the present invention including direct drive with open collector (open drain) transistors, etc.
[0032] In this embodiment, the wireless receiver 72 is connected to an input bit 180 for signaling the firmware running on the processor 110 when a wireless signal is received. Likewise, the push button switch 195 is connected to another input 190 for signaling the firmware running on the processor 110 when the push button is pressed. Many ways are known in the industry to communicate external signals to a processor, all of which are anticipated and included here within. Likewise, other inputs and outputs are anticipated such as diagnostic control signals, etc.
[0033] Referring to FIG. 5 , a flow chart of the prior art is shown. A typical traffic control system of the prior art using a computer system similar to FIG. 4 (without the wireless control) would have an initial state having traffic flowing in one direction (Direction-A) and stopped in the other direction (Direction-B). The system begins with turning on green in Direction-A and red in Direction-B 200 . The system then waits for the amount of time allowed for Direction-A 202 then the system turns off the green and turns on the yellow signal for Direction-A 204 . After a short period of time determined by the timer 206 , the system turns off the yellow in Direction-A, turns on the red in Direction-A, turns off the red in Direction-B and turns on the green in Direction-B 208 . Next, after the amount of time allotted to Direction-B expires 210 , the system turns off the green in Direction-B and turns on the yellow in Direction-B 212 . After another timer 214 , the sequence repeats.
[0034] In some known traffic control systems, the sequencing of lights differs from the examples presented. The present invention is for the automatic and manual operation of a traffic control system and operates with any sequencing of traffic lights known or unknown, including any red clearances as well as yellow clearances and systems that employ different configurations of light such as systems with only red and green lights. Additionally, some systems use sequences that permit the operation of more than one light at a time such as illuminating red and yellow concurrently. All such systems are incorporated in the present invention.
[0035] Referring to FIG. 6 , a flow chart of the alternate embodiment of the present invention is shown. A typical traffic control system using a computer system similar to FIG. 4 (without the wireless control) would have an initial state having traffic flowing in one direction (Direction-A) and stopped in the other direction (Direction-B). The system begins with turning off all signal lights except turning on green in Direction-A and red in Direction-B 220 . The system then waits for a manual change signal 222 then the system turns off the green and turns on the yellow signal for Direction-A 224 . The system then waits for a manual change signal 226 , then the system turns off the yellow in Direction-A, turns on the red in Direction-A, turns off the red in Direction-B and turns on the green in Direction-B 228 . Next, after the system then waits for a manual change signal 230 , the system turns of the green in Direction-B and turns on the yellow in Direction-B 232 . After waiting for a manual change signal 234 , the sequence repeats. This is a typical flow and many traffic systems are known with different flows accommodating left-turn arrows, right-turn arrows, multiple directions of traffic flow, etc. Furthermore, other traffic control systems automatically time the caution period (yellow) even during manual control. All such timings and features are included in the present invention.
[0036] Referring to FIG. 7 , a second flow chart of the prior art is shown. In the prior art, the wait for button press operation was exactly that, the software waited for a button press signal 250 .
[0037] Referring to FIG. 8 , a second flow chart of the alternate embodiment of the present invention is shown. This flow is performed in place of the “waiting for button press 222 / 226 / 230 / 234 of FIG. 6 . In this example, waiting for the button press includes checking to see if the watchdog timer has expired 260 . If it has, the automatic mode is entered 262 . If it has not expired yet, a check is made to see if a wireless signal was received 264 signaling the traffic control system to change. If no wireless signal was received 264 , the process is repeated until either the watchdog timer expires or a wireless signal is detected 264 . If the wireless signal is received 264 , the watchdog timer is reset 266 and waiting is done. In a non-wireless system (tethered control), the system checks for a button press of the tethered control device (not shown) instead of checking for a wireless signal 264 .
[0038] Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.
[0039] It is believed that the system and method of the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes. | An application for a traffic control system includes an enclosure for containing the traffic control system that has an access door with a lock for controlling access to the enclosure through the access door. The traffic control system has an automatic mode of operation and a manual mode of operation, whereas the traffic control system automatically transitions a state of a plurality of traffic lights when in the automatic mode of operation and cycles the state of the plurality of traffic lights in response to a change signal when in the manual mode of operation. An automatic mode activation switch is housed within the enclosure. Activation of the automatic mode activation switch changes the state of the traffic control system from the automatic mode of operation into the manual mode of operation. A watchdog timer is coupled to the traffic control system, The watchdog timer is reset when the automatic mode activation switch is operated and in response to the change signal. If the watchdog timer expires, the traffic control system switches to the automatic mode of operation. | 6 |
BACKGROUND OF THE DISCLOSURE
The present invention is directed to an atherectomy catheter, particularly, a distal atherectomy catheter for use in the distal and coronary arteries where small vessel size and tortuosity present numerous problems of access.
Many technological advancements have been made in recent years for treatment of coronary disease. Surgical bypass techniques such as cardiopulmonary bypass surgery is routinely performed and is highly successful. While the risks of bypass surgery have been minimized through technological advancements, opening of the chest cavity is required. This requires special surgical skills and equipment which are not readily available in many areas. In many patients, a bypass operation may not be indicated and therefore various surgical techniques have been devised to treat occlusive coronary artery disease of such patients. For example, various prior art devices have been developed for removing and/or compressing atherosclerotic plaque, thromboses, stenoses, occlusion, clots, embolic material, etc. from veins, arteries, and the like.
One such device is disclosed in U.S. Pat. No. 4,650,466 (Luther). Luther discloses an angioplasty device comprising a woven tube of metal or plastic fibers and a retraction stylet that are attached at one end of a catheter tube for insertion into a vein, artery and the like for the removal of plaque and similar material. One or more guide wires are attached to the woven tube for rotation and manipulation inside the artery. The woven tube is placed within the artery and expanded to contact the interior, plaque coated wall of the artery. Movement of the expanded woven tube abrades the plaque from the arterial wall to form particles which are trapped within the woven tubes. Removal of the angioplasty device from the artery removes the trapped plaque particles from the patient.
Other prior art devices include catheters fitted with an inflatable balloon for compressing occlusive materials such as plaque against the vessel wall. U.S. Pat. No. 4,273,128 (Lary) discloses a coronary cutting and dilating instrument for treatment of stenotic and occlusive coronary artery disease. The instrument disclosed therein includes a cutting and dilating instrument having one or more radially extending knife blades at a forward end thereof for making the coronary incision and an inflatable balloon for dilating the stenotic artery zone immediately after the incision.
Other angioplasty devices include a catheter having a motor driven cutting head mounted at its distal end. The cutting head is connected to the drive motor via a flexible drive shaft extending through the catheter. Extremely high rotational cutting head speeds have been achieved, in the range of two to three hundred thousand rpm, by these motor driven cutter heads. Various problems, however, have been associated with the use of balloon tipped catheters and high speed cutting heads. The balloon catheter is expanded by injection of pressurized fluid into the balloon to expand it against the wall of the artery. Some problems which have been reported include vessel dissection, perforation, rupture, conversion of a stenosis to an occlusion and embolization. Furthermore, angioplasty devices utilizing balloons do not remove the plaque from the arterial wall but simply compress the plaque against the wall of the vessel. Thus, the stenosis or occlusion frequently reoccur requiring further treatment.
Atherectomy devices utilizing motor driven high speed cutting head include a number of disadvantages. Heat dissipation and vibration is a problem. The path to the occlusion in an artery is often a tortuous path and therefore the flexible drive shaft connected to the cutter head must often traverse a number of bends or curves. Consequently, as the flexible drive shaft rotates, it contacts the inner wall of the catheter resulting in localized heating and vibrations due to the frictional contact. This, of course, is very uncomfortable for the patient and may result in weakening or perforation of the vessel.
It is therefore an object of the invention to provide an atherectomy catheter having a reciprocal cutter head at the distal end thereof.
It is another object of the invention to provide an atherectomy catheter for traversing the small and tortuous vasculature of the heart and having the ability to bore through a total obstruction and excise a hemispherical or circumferential section from the lumen of the vessel and entrap the excised section within a containment housing.
It is yet another object of the invention to provide an atherectomy catheter for progressively opening the lumen of a vessel, entrapping and discharging the excised specimen into a containment housing on the catheter until the entire obstruction has been removed leaving a smooth fissure and flap-free enlarged internal vessel diameter.
SUMMARY OF THE INVENTION
A distal atherectomy catheter is disclosed for removing obstructions, plaque, stenosis, occlusions, or the like from an artery or coronary vessel. The catheter comprises a flexible hollow outer catheter tube housing a reciprocal cutting element at its distal end. The cutting element is connected to an inner catheter tube concentrically located within the outer tube. An annular return passage is defined between the inner and outer tubes providing a discharge passage communicating with an external vacuum means for collection of cuttings. A flexible drive cable extends through the inner catheter tube terminating in a detachable cutting diamond or carbide burr for boring through obstructions in the vessel. The drive cable is connected to an external drive motor.
DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a partial sectional view of the apparatus of the invention;
FIG. 2 is an enlarged sectional view of the cutting head of the invention; and
FIG. 3 is a sectional view of an alternate embodiment of the cutting head of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, the catheter of the invention is generally identified by the reference numeral 10. The catheter 10 of the invention comprises a flexible outer catheter tube 12 which may be several feet in length. Received within the outer catheter tube 12 is an inner catheter tube 14. The inner catheter tube 14 is concentrically located within the outer catheter tube 12 defining an annular passage 16 therebetween. The annular passage 16 provides a return passage for excised plaque or tissue removed from the arterior wall.
The proximal ends of the inner and outer catheter tubes 12 and 14 are connected to a hand-actuated manipulator assembly generally identified by the reference numeral 20. The manipulator assembly 20 comprises a handle 22 connected to a coupling 24 which is in turn connected to a "Y" fitting and pressure assembly 26. The pressure assembly 26 includes a flared tubing connector 28 which secures the end of the outer catheter tube 12 to the pressure assembly 26. The pressure assembly 26 branches to form a "Y" configuration. One branch of the pressure assembly 26 defines an outlet passage 30. The outlet passage 30 is connected to a vacuum source (not shown in the drawings) for removal of excised plaque or tissue to a collection vessel. A tubing connector 32 connects one end of the pressure vessel 26 to the coupling 24. An 0-ring 34 is compressed by the connector 32 about the inner catheter 14 thereby terminating the annular passage 16 so that excised plaque and tissue is directed through the outlet passage 30 to the collection vessel.
The inner catheter 14 extends through the pressure assembly 26 and is connected to an inner catheter manipulator 36 which extends into a longitudinal hollow and cut-out portion of the handle 22. A slide member 38 is securely fastened to the catheter manipulator 36 which connects to the inner catheter 14. The slide member 38 is spring biased for reciprocating the inner catheter 14 for excising plaque or tissue from the coronary vessel. Set screws 40 secure the slide member 38 to the catheter manipulator 36 and are adjustable to set the cutting length of the cutting head assembly.
The atherectomy catheter 10 of the invention as shown in FIG. 1 includes a flexible drive cable 42 which extends through the inner catheter 14 and terminates in a detachable cutting head or carbide burr 44. The drive cable 42 extends through the manipulator assembly 20 and is connected to an external drive source for rotating the drive cable 44 to bore through an obstruction in the coronary vessel. Boring may be accomplished at a relatively low RPM permitting the nose portion of the cutting head of the invention to be inserted into the bored lumen so that the obstruction may be excised.
Referring now to FIG. 2, the cutting head assembly 50 of the invention is shown in greater detail. The outer catheter tube 12 defines a sectioning blade 52. The blade 52 is formed by removing a section of the outer catheter tube 12 forming a port or slot permitting access to the interior of the outer catheter 12. The slot 54 defines a "duck bill" profile terminating at point 56. The duck bill profile aids in grabbing the tissue to be excised. As the tissue or obstruction material drops into the slot 54, it is pushed against the point 56 and speared and held stationary for removal by the slide cutter.
A slide cutter 58 is mounted to the distal end of the inner catheter tube 14. The slide cutter 58 defines a hollow substantially cylindrical body terminating in a nose portion 60 which is welded or bonded to the distal end of the inner catheter tube 14. The trailing or cutting end 62 of the sliding cutter 58 defines a circumferential cutting blade. The end 62 includes a groove 64 formed therein. The groove 64 has a sharp radius of curvature so that the external and internal edge of the end 62 define a circumferential, knife-like cutting surface.
In operation, the catheter 10 of the invention may be used to remove plaque or blockages from coronary arteries or vessels in the human body. For purposes of illustration, the following discussion will be directed to the use of the catheter 10 in removing an obstruction from a coronary artery. To this end, the catheter 10 is introduced into the body of the patient through a femoral artery or some other artery selected by the physician. The catheter 10 is pushed through the femoral artery to the site in the coronary artery requiring removal of an obstruction. Once the obstruction is reached, the drive cable 42 is rotated and advanced so that the burr 44 bores into the obstruction and the nose portion 60 is inserted in the bore formed by the burr 44 for dilating the vessel. As the catheter 10 advances through the vessel, the inner catheter 14 is retracted so that the slide cutter 58 reciprocates within the sectioning blade 52 of the outer catheter tube 12. This reciprocating motion excises a hemispherical or circumferential section of the obstruction and entraps the excised plaque or tissue within the annulus 16. Each excision progressively opens the vessel, excising and discharging sections of the obstruction into the annulus 16 until the entire obstruction has been removed. Upon removal of the obstruction, the coronary vessel has a smooth and flap free enlarged internal diameter.
The slot 54 is keyed to the manipulator assembly 20 so that its rotational position is known and the obstruction may be completely removed by rotating the atherectomy catheter of the invention 360° within the coronary vessel. To insure that substantially all of the obstruction is removed, a deflection wire 66 extends through the outer catheter tube 12 and exits the tube 12 at 68 and is welded to the forward end of the outer catheter tube 12 at 70. Manipulation of the deflection wire 66 permits the cutting head to be forced against the inner wall of the coronary vessel so that substantially all of the obstruction is removed and the internal diameter of the vessel is substantially free of any obstruction.
Insertion of the atherectomy catheter 10 through the femoral artery of the patient requires that it follow a tortuous path through bends and curves, in the coronary artery or vessel. To facilitate insertion of the catheter 10, sections of the inner and outer catheter tubing 12 and 14 include a bellowed portion, for example bellows 63 and 65 shown in FIG. 1-3. The bellows 63 and 65 entrance the flexibility of the catheter 10 so that it may more easily traverse the bends and curves encountered in the coronary artery or vessel.
Referring now to FIG. 3, an alternate embodiment of the cutting head assembly of the invention is disclosed. The cutting head assembly shown in FIG. 3 is substantially similar to the cutting head assembly of FIG. 1 and therefore like reference numerals are used to identify like elements. In the cutting head assembly 70 shown in FIG. 3, the outer catheter tube 12 includes a sectioning blade 72 mounted on the distal end thereof. The sectioning blade 72 is substantially cylindrical in shape and welded or otherwise bonded to the distal end of the outer catheter tube 12. The sectioning blade 72 includes an angled yet circumferential cutting surface 74 formed by cutting through the cylindrical body of the sectioning blade 72 at an angle of approximately 45°.
A slide cutter 76 is mounted to the distal end of the inner catheter tube 14. The slide cutter 76 defines a hollow substantially cylindrical body terminating in a nose portion 60 which is welded or bonded to the distal end of the inner catheter tube 14. The internal diameter of the slide cutter 58 is substantially equal to the external diameter of the sectioning blade 74 which is slidably received within the slide cutter 58 upon reciprocation. In operation, the cutting head assembly 50 operates in substantially the same manner as the cutting head assembly 50 shown in FIG. 2, however, the slide cutter 76 slides externally or about the sectioning blade 72 for excising the obstruction in the coronary vessel.
While the foregoing is directed to the preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow. | A distal atherectomy catheter comprises a flexible outer catheter tube housing a reciprocal cutting element at its distal end. The cutting element is connected to an inner catheter tube concentrically located within the outer catheter tube. An annular passage defined between the inner and outer tubes provides a discharge passage communicating with an external vacuum mechanism for collection of excised material removed from the coronary vessel. A flexible drive shaft extending through the inner catheter tube terminates in a detachable cutting burr for boring through obstructions in the coronary vessel. The drive cable is connected to an external drive motor. | 0 |
TECHNICAL FIELD
[0001] The present disclosure relates to dragline mining machines and particularly to a configuration of boom chord and lacing for dragline machines used in mining.
BACKGROUND
[0002] Dragline machines use a large bucket suspended from a boom to move a payload, such as earth or ore, at a worksite. The boom for the dragline may be more than 400 feet long and has numerous weld joints that need routine inspection and periodically need repairs. The boom may be constructed of chords running the length of the boom and lacings that connect the chords with a series of geometric patterns, such as triangles, that provide support for the bucket and payload, as well as the boom itself.
[0003] Tubular booms use round steel pipes for chords and lacings with the chords diameter being larger than the lacing diameter. Some lacings are perpendicular to the chords and some are at an angle. In both cases, the end of the lacing must be formed to match the round contour of the mating surface on the chord using a coping cut on the end of the lacing. Further, because the lacings often terminate in the same spot, the weld joints overlap.
[0004] The closed interior of the chord pipe makes it difficult to inspect the back side of the weld joint. Further, overlapping weld joints at a particular attachment point on a chord make it difficult to inspect for damage to a weld or lacing. Overlapping weld joints also make repairs costly and time consuming because multiple lacings are affected each time one lacing is repaired or replaced.
[0005] G.B. 523,571A (the '571 patent), titled “Improvements in or relating to construction of Buildings” teaches the use of a formed metal plate in a truss with lacing supports that avoids coping cuts for lacing attachments. The '571 patent uses formed metal across one entire side of the triangle-shaped structure. This adds weight and cost that would be unacceptable if applied to a boom structure.
SUMMARY OF THE DISCLOSURE
[0006] In one aspect of the disclosure, a boom for a dragline machine includes a plurality of chords, each chord having a first mounting surface and a second mounting surface, the first and second mounting surfaces being planar and forming a reflex angle and the respective inside surfaces for the first and second mounting surfaces being planar and forming an obtuse angle. Each chord may be arranged so that at least one of the first and second mounting surfaces are facing and generally parallel with one mounting surface of another of the plurality of chords. A plurality of lacings may be used to couple respective facing mounting surfaces of the plurality of chords.
[0007] In another aspect of the disclosure, a method of making a boom includes forming a metal plate into a chord having outside surfaces at a reflex angle and inside surfaces at an obtuse angle. The method includes forming additional chords from additional metal plates. The additional chords may have an identical cross section to the chord or may have a different shape from the chord. The chord and the additional chords may be coupled with lacing so that one outside surface of each chord faces a respective outside surface of one other chord.
[0008] In yet another aspect of the disclosure, a boom for a dragline machine may include three chords, each chord made from a metal plate formed into three planar surfaces, each chord having at least one obtuse angle between adjacent planar surfaces. The boom may also include a plurality of inter-chord lacings made of pipes, each end of each inter-chord lacing lying in a single plane, wherein each lacing is attached between facing surfaces of two chords.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an illustration of a dragline machine;
[0010] FIG. 2 is a perspective view of a portion of a boom of the dragline machine;
[0011] FIG. 3 is a perspective view of a detail of the boom;
[0012] FIG. 4A is a perspective view of another detail of the boom;
[0013] FIG. 4B is a perspective view of an alternate embodiment of the boom detail of FIG. 4A ;
[0014] FIG. 5 is an end view of a section of the boom;
[0015] FIG. 6 is an end view of an exemplary top chord of the boom;
[0016] FIG. 7 is an end view of an exemplary side chord of the boom;
[0017] FIG. 8 depicts attachment relationships between chords and lacings of an exemplary boom; and
[0018] FIG. 9 is an end view of an alternate embodiment of the boom with four chords;
[0019] FIG. 10 is a flowchart of a method of making a boom in accordance with the current disclosure.
DETAILED DESCRIPTION
[0020] FIG. 1 is a simplified illustration of a dragline machine 100 . The dragline machine 100 has a base 102 with an operator station 104 . The dragline machine 100 also has a boom 106 that is used to support a bucket 108 . The bucket 108 may be dragged along a work site surface 109 to collect and move material.
[0021] FIG. 2 is a perspective view of the boom 106 of the dragline machine 100 . The boom 106 may include a first chord 110 , a second chord 112 , and a third chord 114 . In the illustrated embodiment, the first, or top, chord 110 has one shape and the second and third chords 112 , 114 , are generally mirror images of each other and may be symmetric from a manufacturing perspective. In other embodiments, the boom 106 may have asymmetric chords.
[0022] The chords 110 , 112 , 114 are connected using inter-chord lacings. For example, lacing 116 and lacing 120 are perpendicular inter-chord lacings. Inter-chord lacings 118 and 118 a are oblique inter-chord lacings. Internal lacings 122 , 124 , 126 are connected in whole or in part to other lacings. In the illustrated embodiment, each internal lacing 122 , 124 , 126 is coupled at one end to one of the chords 110 , 112 , 114 and at the other end to another lacing 120 .
[0023] Supports 128 and 130 are disposed along inside surfaces of the chords 110 and 112 , 114 respectively and are formed to match the interior regions of their respective chords 110 and 114 , as shown in more detail in FIGS. 6 and 7 . The supports 128 and 130 may be disposed either at points opposite where lacings are attached or may be attached anywhere mid-span of the lacing attachments to provide strength and stability to the chords on which they are disposed.
[0024] FIG. 3 is a perspective view of a detail of the boom 106 . FIG. 3 shows the attachment of chord 114 and perpendicular inter-chord lacings 116 and 120 as well as oblique inter-chord lacing 118 a. Also shown is internal lacing 124 a. Each of the lacing attachments may be positioned such that neither the lacing nor its associated weld joint 132 touches or overlaps another lacing/weld joint. This positioning facilitates inspection of weld joints and lacings. The positioning also facilitates repair or replacement of lacings or their weld joints because no other lacing must be cut or removed during the operation, in contrast to current, overlapping lacing implementations.
[0025] FIG. 4A is a perspective view of another detail of the boom 106 . Perpendicular inter-chord lacing 120 is shown with internal lacings 122 , 124 , and 126 . In an embodiment, the inter-chord lacing 120 is a pipe, similar to other lacings. In another embodiment, the inter-chord lacing 120 may also be formed from a metal plate such that the lacing is open on one side, similar to the chords 110 , 112 , and 114 . The open side of the lacing allows both sides of the weld joint to be visually inspected and the internal lacings 122 , 124 and 126 to have flat, planar end cuts, as discussed in detail below.
[0026] FIG. 4B is a perspective view of an alternate embodiment of the boom detail of FIG. 4A . In this embodiment, the inter-chord lacing 120 A is made from a rectangular pipe with the internal lacings 122 A, 124 A, and 126 A also being made of rectangular pipes. In an alternate embodiment the inter-chord lacing 120 A and the internal lacings 122 A, 124 A, and 126 A may be made from square tubing or tubing of another shape. In yet other embodiments, lacings of various shapes may be wed together. For example, an embodiment may use rectangular inter-chord lacings 120 A and round internal lacings 124 , 126 so that the internal lacings 124 , 126 also benefit from having planar end cuts, avoiding the coped end cuts required by round-on-round connections.
[0027] In another embodiment, the inter-chord lacing 120 A may be formed from a metal plate and may have a U-shaped profile or an asymmetric profile with two sides perpendicular for mounting internal lacings 122 A, 124 A, and 126 A. For example, the inter-chord lacing 120 A may have a profile the same or similar to that of the chord 114 illustrated in FIG. 7 .
[0028] FIG. 5 is an end view of a cross-section of the boom 106 . In the illustrated embodiment, the boom has an isosceles triangle shape, with symmetric lacings 116 and a base lacing 120 longer than either side lacing 116 . In another embodiment, the boom 106 may have an equilateral triangular cross-section. In this latter case, each chord 110 , 112 , 114 would be symmetric, similar in shape to chord 110 shown in FIG. 5 .
[0029] FIG. 5 also illustrates supports 128 and 130 , being formed to contact the inside surface of their respective chords 110 and 114 . In an embodiment, the supports 128 and 130 are flat metal plates disposed perpendicular to a length of the chord and are welded to the inside surfaces of the chords.
[0030] FIG. 6 is an end view of an exemplary top chord 110 of the boom 106 . The chord 110 may be formed from a sheet of metal, such as steel. The chord 110 may include a bottom mounting surface 140 and two side mounting surfaces 142 and 144 . The mounting surfaces 140 , 142 , 144 are planar and may be used to attach lacings, either inter-chord lacings or internal lacings. The mounting surfaces 140 , 142 , 144 form an open inverted frustum shape where the mounting surfaces 140 , 142 and 144 may also be considered outside surfaces. Each mounting or outside surface 140 , 142 , 144 has a respective inside surface 141 , 143 , 145 . The junction of adjacent mounting surfaces, for example, the junction of adjacent mounting surfaces 140 and 142 form a reflex angle 146 . The junction of adjacent inside surfaces 141 , 143 form an obtuse angle 148 . The support 128 is formed to contact in full or in part, each of the inside surfaces 141 , 143 , 145 . Note that a reflex angle is greater than 180 degrees and less than 360 degrees while an obtuse angle is greater than 90 degrees and less than 180 degrees.
[0031] FIG. 7 is an end view of an exemplary side chord 114 . The chord 114 has outside, or mounting surfaces 150 and 152 . Each mounting surface 150 and 152 has a respective inside surface 151 and 153 . The adjacent mounting surfaces 150 and 152 form a reflex angle 154 . The inside surfaces 151 and 153 form an obtuse angle 156 . The chord 114 may include a third leg 157 with an inside surface 158 . The additional leg 157 helps increase the stability and load-bearing capability of the chord 114 . The support 130 is formed to contact in full or in part each of the inside surfaces 151 , 153 , and 158 .
[0032] For both the top chord 110 and the side chord 114 , the supports 128 and 130 are coupled to the inside surfaces of the chords. The supports 128 and 130 help prevent the chords 110 and 114 from deflecting due to lacing forces, that is, those forces occurring during both at rest due to gravity and also by movement of the boom when material is loaded and unloaded. The supports 128 and 130 also limit twist and buckling of the chord 110 and 114 .
[0033] FIG. 8 depicts attachment relationships between chords 110 , 114 and lacings 116 , 120 , and 164 of an exemplary boom 106 . The mounting surface 142 of chord 110 defines a first plane. The mounting surface 150 of the chord 114 defines a second plane. The chords 110 and 114 are arranged so that the first and second plane are generally parallel. Therefore, a perpendicular inter-chord lacing 116 attached to the mounting surfaces 142 and 150 will be perpendicular to both chord mounting surfaces 142 and 150 .
[0034] Similarly, an inter-chord lacing 120 will be perpendicular to both mounting surfaces 152 and 162 of the side chords 112 and 114 . A lacing 164 connecting mounting surfaces 144 and 160 will also be perpendicular to the plane defined by those mounting surfaces 144 , 160 . The end of each of these lacings lies in a single plane and can be cut with a single cut of, for example, a circular saw, band saw, or cutoff saw to form a planar end cut. The complex coping cuts required for round lacing attachment to round chords of prior boom implementations are avoided. As can be seen in FIGS. 3 and 4 , even oblique inter-chord lacings or the chord-side attachment end of an internal lacings will have ends that lie in a single plane, i.e., that can be made with a single cut-off cut.
[0035] Further, the open frustum shape of the chords 110 , 112 , 114 allows visual inspection of both sides of weld joints that attached the lacings to the chords 110 , 112 , 114 . This improves the quality of an inspection because both sides of a chord can be easily viewed so that cracks and imperfections can be identified.
[0036] FIG. 9 is an end view of an alternate embodiment of a boom 170 having four chords 172 , 174 , 176 , and 178 . The four-chord boom uses individual chords with a similar open frustum shape described above that allows inter-chord lacings 180 , 182 , 183 , and 186 to have planar end cuts and internal chords 188 , 190 to have at least the chord-ends with planar end cuts. This four chord embodiment also preserves the open back of the chords of FIGS. 6 and 7 so that compared to prior art round-chord booms inspections are easier and more effective and repairs can be more efficiently effected. The additional feature of offset lacing welds is also maintained in this embodiment.
INDUSTRIAL APPLICABILITY
[0037] FIG. 10 is a flowchart 200 of a method of making a boom 106 . At a block 202 , a metal plate may be formed into a chord 110 with an inverted frustum shape having outside surfaces at a reflex angle and inside surfaces at an obtuse angle. The metal plate may be steel, aluminum, or another composition.
[0038] At block 204 , additional chords 112 , 114 may be formed from additional metal plates; the shape of the additional chords may be the same or different as the chord formed at block 202 .
[0039] At block 206 , lacings may be formed with a planar end profile. That is, lacings made of round pipe may have ends that form a single plane, either perpendicular to a longitudinal axis of the pipe or oblique to the longitudinal axis. For example, the chord-end of any lacing may be cut with a band saw, a cutoff saw, or a circular saw.
[0040] At block 208 , the chord 110 and the additional chords 112 , 114 may be coupled with lacing so that one outside surface 142 , 144 of a first chord 110 faces a respective outside surface 150 , 160 of one other chord 112 , 114 . Coupling the chord 110 and the additional chords 112 , 114 with lacing may also include attaching each end of a lacing 116 to the outside surfaces 142 , 150 of two facing chords 110 , 114 . Coupling the chord 110 and the additional chords 112 , 114 with lacing may also include attaching each end of the lacing so that no lacing, e.g., lacing 116 , is in contact with another lacing, e.g., lacing 118 a. The lacings are typically attached with welds, but in the case where other materials or composites may be used for the chords, the chords and lacings may have different attachments, such as rivets, bolts, or epoxies.
[0041] At block 210 , a support 128 , 130 may be disposed between the inside surfaces of the chord. The support 128 130 may be a formed plate that is attached perpendicular to a length of a chord 110 , 112 , 114 and in contact with the inside surfaces 141 , 143 , 145 and 151 , 153 , 158 of respective chords 110 , 114 . Chord 112 may be a mirror image of chord 114 and has similar inside surfaces that contact similar supports. The supports 128 , 130 may be disposed opposite points where a lacing is attached or may be disposed mid-span between lacings.
[0042] The use of formed chords rather than tubular pipe chords has the advantage of allowing both sides of a weld joint to be inspected and repaired. The separation of lacing attachment points allows a lacing and its welds to be individually inspected and, if needed, repaired without impacting other lacings. Dragline machine booms 106 are typically inspected every month. Since a boom 106 of a dragline machine 100 may be over 400 feet long and have hundreds, if not thousands, of lacings and welds, any improvement in the inspection and repair processes may have a considerable impact on machine up-time. However, the advantages of the chord and lacing techniques disclosed herein are not limited to dragline machines 100 . Any chord-based support structure may benefit from the formed chord and offset lacings discussed in this disclosure, including, but not limited to, portable cranes, overhead cranes, conveyor system supports, antenna towers, etc. | A boom uses formed plates instead of a round pipes for the chords of the boom. Each formed plate provides a flat surface for attaching lacings so that complex coping cuts required for round pipe chords can be eliminated. The boom also displaces lacing attachment points so that overlapping welds in previous boom assemblies are also eliminated. The open back of the formed plate and non-overlapping lacing attachment points eliminate hidden welds and obscured mounting surfaces that make inspections and repairs of current boom assemblies difficult or impossible. | 4 |
This is a continuation of copending application Ser. No. 07/541,512 filed on Jun. 21, 1990 now U.S. Pat. No. 5,073,825, which is a continuation of application Ser. No. 07/034,691 filed on Apr. 6, 1987 which has matured into U.S. Pat. No. 4,939,582.
BACKGROUND OF THE INVENTION
This invention relates to a convertible audio-visual display device. It is particularly related to a device which will mount on the baby's crib and provide audio and visual stimulation for the baby for entertaining and educating the baby. The unit converts to a useful, computer station by means of simple adjustments to permit the parents or others to utilize the device with a home or personal computer or word processor.
In the past, television cameras have been used to monitor infants, patients, prisoners, and the like and mothers have permitted their older children to watch television and the like to entertain them when they were older. However, nothing has been done to entertain and to stimulate younger children, for example, infants who are confined to cribs.
SUMMARY OF THE INVENTION
In the instant invention a canopy is provided which has an end wall, a top horizontal wall, and two side walls with the bottom and the front walls being open. The canopy is adapted to be securely mounted on the crib so as to provide secure means for fastening said canopy to the crib so that the canopy lies over where the baby normally rests. The top wall of the canopy (when the canopy is in place on the crib) is provided with a recess for mounting and supporting an audio-visual unit. The side walls of the canopy are adapted to receive, and to support, speaker means.
When the canopy is removed from the crib it is adapted for its end wall to rest on a table top or desk top or the like and to, in turn, support a computer or word processing console.
It is an object of the invention to provide a convertible audio-visual device which serves the multi-function of entertaining young babies either audibly or visually or in combination.
It is another object of the invention to provide an audio-visual device which can support and compliment a computer console with a single adjustment of the device.
These and other objects will become apparent when reading the attached specification in conjunction with the drawings appended thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
The construction designed to carry out the invention will hereinafter be described, together with other features thereof.
The invention will be more readily understood from a reading of the following specification and, by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:
FIG. 1 is a side elevation of a crib showing the canopy of the invention in place thereon;
FIG. 2 is a cross-sectional view taken along lines 2--2 of FIG. 1;
FIG. 3 is a sectional view taken along lines 3--3 of FIG. 2;
FIG. 4 is an enlarged side view of the device of the invention as seen in FIG. 3 and shows more details of the mounting of the visual display unit in the canopy;
FIG. 5 is an enlarged cross-sectional view showing one of the side walls of the canopy as it fits on the top rail of a crib;
FIG. 6A is a front perspective view of the adapter for supporting the canopy securely on the headboard of the crib.
FIG. 6B is a rear perspective view of the adapter for supporting the canopy securely on the headboard of the crib;
FIG. 7 is an exploded perspective view of the video display unit and a computer console with the canopy removed from the crib and supported on a table or desk; and
FIG. 8 is a diagramatic view showing the video display unit alternately connected to a video source or to personal computer.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1, 2, 3, 4, 5, 6A and 6B wherein is illustrated the convertible audio-visual display center 10 which comprises a canopy 12 resting on a crib 14. Canopy 12 is supported by the top side rails 16 and on the head board 18 by an adapter 19, which will be described in detail, below. The crib also includes side and bottom rails 17, foot board 20 and a mattress 22.
Canopy 12 comprises a top wall 23, an end wall 36, and side walls 32. Top wall 23 has a recess 25 into which is fitted a video display unit 24. The video display unit 24 is held within the recess 25 by means of brackets 28 and bolts or screws 30. As can best be seen in FIGS. 3 and 4, the top of video display unit 24 is disposed in the recess adjacent to end wall 36 when the canopy is in place on the crib. Furthermore, the screen of the video display unit is tilted so that the bottom of the screen is closer to the surface of mattress 22 than is the top of the screen. The reason for this being that the baby, when lying on mattress 22 will have a more comfortable view of the screen than it would have if the screen was flush with the surface of the top wall of the canopy.
In each side wall 32 of the canopy is disposed at least one speaker 26 for conveying sounds such as voices, music, or the like for the listening pleasure of the baby. Speakers 26 and video display unit 24 are connected to a video and/or audio source by means of a coaxial cable 44 or the like. The source to which the coaxial cable 44 or the speakers are connected may be a radio, stereo, television, video cassette recorder, or the like for generating the radio and/or video signals to be reproduced by the video display unit and/or the speakers.
Whenever canopy 12 is in position bridging the side rails 16 of the crib, it is supported by the side rails and the head board 18 through adapter 19. Each canopy side wall 32 terminates in a foot 34 at the bottom edge of said side walls which is adapted to receive the top surface of top rails 16 as can best be seen in FIG. 5. In addition, canopy end wall 36 terminates in an end portion which rests upon the adapter 19 supported by the upper part of the head board 18 as best seen in FIG. 6. Canopy end wall 36 is held securely to head board 18 by means of a plurality of bolts 40 and nuts 42. Thus, when the canopy 12 is firmly attached to the crib there is no liklihood or possibility that the canopy would be dislodged or fall upon the baby.
Referring now more particularly to FIGS. 6A and 6B wherein adapter 19 is illustrated in perspective and in detail, adapter 19 has a U-shaped portion 50 having legs 50a and 50b which straddle headboard 18. On the mattress side of the headboard is a thickened portion 52 which extends between the mattress and the headboard and is held in place in contact with the headboard by means of bolts 54 which extend through openings 53 in both the headboard and the adapter. Nuts may be threaded on bolts 54 to securely hold the adapter in place against the headboard.
Near the upper end of the adapter 19 is a reduced portion 57 to form a ledge 55 which has a thickness equal to the thickness of the canopy end 36. When the canopy end is in place on the bolts 40 extend through holes 56 into the wall of the end portion and securely bolt the canopy end to adapter 19. Access openings 58 are provided in the rear wall of portion 50 of the adapter to permit bolts 40 to be threaded into the canopy. Covers 59 are provided for filling the access openings once the adapter is firmly and securely bolted to the canopy end for sake of appearance.
The adapter 19, as described herein, may be formed of a rigid plastic or from steel. In either case, the surface of thickened portion 52 will be padded where it comes, or lies, adjacent to the head of the baby, in operation, so as to avoid harmful contact between the baby and the adapter.
When it is desired to convert the audio-visual display center 10 for use as a computer console or work station, the canopy 12 is disconnected from the crib and the adapter and it is placed onto a table top with the canopy end 36 in the horizontal plane and the canopy top wall 23 now in the vertical plane, as seen best in FIG. 7. When the conversion is made the video display unit 24 is loosened in its brackets 28 and bolts 30 and is reversed one hundred and eighty degrees (180°) with the top of the display unit now being adjacent to the open end of the top of the canopy 12. The keyboard 46 for the computer is now supported by end wall 18, which is now in the horizontal plane, and the keyboard may be attached to end 18 by suitable brackets or screws such as brackets 28 and bolts or screws 30. In this case, the cable 44 will be connected to the keyboard of the computer as desired and the video display unit 24 will now display the results of the operation of the computer.
As seen in FIG. 8, the video display unit 24 may be connected alternately to either the video source 45 or to a computer console 36 depending on which mode of operation is desired at the time.
The video display unit 24 disclosed herein may be any state of the art video display units available in the market place. This may use a picture tube or a liquid display, as desired, and as required by space requirements, the selection of which lies within the scope of those skilled in the video art. The particular type of video display unit is not critical to the operation of the present invention.
The words used to described this invention herein are words of description only and are not deemed to be limiting in nature. The scope of applicant's protection is to be measured only by the claims appended thereto.
It is also understood that the means for connecting the video display unit to the canopy may vary and that the coaxial cable may be replaced by other suitable connectors for conveying the electronic signals to the video display unit.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. | A convertible audio-visual display center adapted to reproduce visual images on a video display unit such as a television and audio reproductions of sound or music for the entertainment and/or education of infants in their cribs. The same device is readily convertible to usage as a work station for a computer console with simple adjustments. | 8 |
This nonprovisional application claims the benefit of U.S. Provisional Application No. 60/011,045, filed Feb. 2. 1996.
FIELD OF THE INVENTION
The present invention relates to benzoylecgonine conjugates that are useful as diagnostic reagents for cocaine detection methodology. This invention also relates to methods of synthesizing benzoylecgonine conjugates.
BACKGROUND
A wide variety of ways have been developed for determining minute quantities of various organic compounds. A number of agents have been used for the detection of various organic compounds. These agents are conjugated with receptors, detector molecules, antibodies, antigens, etc. that recognize particular compounds or a class of compounds. The most common type of receptor is an antibody that is able to strongly bind to a particular spatial conformation and polar or non-polar distribution.
In order to prepare antibodies for compounds which are not antigenic, the non-antigenic compound is normally bonded or conjugated to an antigenic material, usually a protein. With most compounds, it is necessary to modify the compound of interest that bonds to the antigen.
In some immunoassays, it is necessary to bond the compound to be detected to a detector molecule (reporter molecule). The link that is chosen for bonding this compound to the antigen or to the detector molecule must allow not only for satisfactory bonding to these molecules, but also must allow an antibody to recognize the compound when it is bound to the detector molecule.
In addition, the linking group must not significantly change the polar characteristics of the compound to be assayed nor detrimentally affect the molecules to which the compound is bonded. Depending on the properties of the particular material to which the compound is to be bonded, the linking group should permit a sufficient number of the desired compounds to be bonded to the antigen, antibody or detector molecule. Additional considerations include synthetic simplicity, chemical stability, the effect of the bonding functionality on the material to which it is bonded, and the particular site on the material, for example a protein, to which the compound will be bonded.
Benzoylecgonine is a key metabolite of cocaine and structurally they are closely related. Monoclonal and polyclonal antibodies raised against benzoylecgonine cross react with cocaine. Benzoylecgonine has a free carboxylic group which can be used as a site for conjugation to various proteins for immunological characterization of cocaine. Benzoylecgonine-horseradish peroxidase conjugate (BE-HRP) can be used as a diagnostic reagent for detection of cocaine employing standard immunological assay procedures.
Generally, primary amine or carboxylic group containing haptens are conjugated to antibodies and enzymes by using water-soluble carbodiimides. The reactions are invariably random and may lead to drastic reductions in antibody and enzyme activity. An alternative and a better approach would be aldehyde-amine condensation utilizing amino groups of haptens and aldehyde groups generated on the carbohydrate moieties of glycoproteins. Since the carbohydrate moieties of antibodies and enzymes are generally not required for their activities, conjugation of haptens through the carbohydrate moieties should not affect their activities. However, in this process condensation of a primary amine to an aldehyde group yields an unstable Schiff base which has to be reduced using sodium cyanoborohydride to obtain stable conjugates. The yields of conjugates are often low because Schiff bases are unstable at the pH employed for the cyanoborohydride reduction. Moreover, the use of cyanoborohydride may lead to a decrease in the biological activity.
U.S. Pat. No. 5,066,789 to Srinivasan et al. describes Schiff base hydrazone linkages for conjugation. A diagnostic or therapeutic agent is converted into an agent-hydrazide through reaction with a maleimidehydrazide heterobifunctional linker. The free aldehyde group of the targeting substance-linker is then reacted with the diagnostic/therapeutic agent-linker hydrazide, yielding a targeting substance conjugate. The targeting substance hydrazide is covalently attached through a stabilized Schiff base linkage to an aldehyde or ketone group present on a diagnostic or therapeutic agent.
U.S. Pat. No. 5,369,007 to Kidwell describes a microassay on a card which is useful for drug testing. The reference also describes the preparation of a cocaine-enzyme conjugate. Aldehyde containing HRP is reacted with p-aminococaine to obtain a p-aminococaine-horseradish peroxidase conjugate.
U.S. Pat. No. 4,197,237 to Leute et al. describes nitrogen derivatives of benzoyl ecgonine and cocaine, particularly amino, diazonium, and diazo derivatives. The enzyme may be conjugated to the nitrogen derivatives of benzoyl ecgonine and cocaine. Various enzymes may be used such as oxidoreductases, oxidases, reductases, etc.
U.S. Pat. No. 4,123,431 to Soffer et al. describes non-oxo-carbonyl substituted derivatives of cocaine which may be conjugated with other compounds for detection of cocaine. Protein molecules (enzymes) may be conjugated with the non-oxo-carboxyl derivatives. Non-ecgonine may displace chlorine on a haloaliphatic carboxylic acid and subsequently be activated using carbodiimide.
U.S. Pat. No. 3,917,582 to Soffer et al. describes benzoyl ecgonine derivatives having an isothiocyanate group for conjugation to polypeptides and proteins for immunoassays. Particularly, the isothiocyanate is conjugated to enzymes or antigenic polypeptides or proteins. The enzyme conjugate is utilized for detection of benzoyl ecgonine. The isothiocyanate compound is prepared by esterifying benzoyl ecgonine followed by hydrogenation and subsequent derivation using thiophosgene. The isothiocyanate is then conjugated to a poly(amino acid). The poly(amino acid) may be an oxidase.
U.S. Pat. No. 5,233,042 to Buechler describes derivatives of cocaine which are conjugated to antigenic proteins or polypeptides for use in immunoassays. The preferred derivatives are the ethyl amide benzoyl ecgonine derivatives. Benzoyl ecgonine hydrate is added to an amide benzoic acid and carboxyldiimidazole, the product of which is then reacted with ethyl amine hydrochloride.
U.S. Pat. No. 5,376,667 to Somers et al. describes benzoyl ecgonine, ecgonine and ecgonidine derivatives which are utilized in pharmaceutical compositions. The products are obtained by reacting propylene glycol with cocaine.
U.S. Pat. No. 3,817,837 to Rubenstein et al. describes enzyme-ligand conjugates and various linking groups between the conjugate of ligand-enzyme. The ligand-enzyme conjugate may be used to detect narcotics. The ligands may be narcotics, such as morphine. The enzymes may be peroxidases.
SUMMARY OF THE INVENTION
The present invention relates to the application of conjugates of benzoylecgonine. The invention also relates to methods of synthesizing benzoylecgonine conjugates using hydrazide derivatives of benzoylecgonine.
Hydrazide derivatives of benzoylecgonine are prepared by carbodiimide-activated coupling of benzoylecgonine to hydrazide derivatives. The benzoylecgonine hydrazide derivatives are then coupled to the carbohydrates, polypeptides, proteins (enzymes, antibody, glycoproteins), polysaccharides, filter paper supports, related carbohydrates, dyes, biotins or the like.
The benzoylecgonine conjugates may be used, for example, in screening anticocaine antibodies, detection of cocaine, cocaine receptor studies and in immunoassay processes. Cocaine receptor studies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a scheme for the synthesis of benzoylecgonine hydrazide and mono-N-(2'-benzoylecgoninoyl)adipic dihydrazide.
FIG. 2 demonstrates a carbohydrate compositional analysis of HRP (panel A) and periodate-oxidized HRP (panel B). HRP (10 μg) and periodate-oxidized HRP (10 μg) were hydrolyzed as described herein. The hydrolysates corresponding to 2 μg protein were chromatographed on a CarboPac PA1 high-pH anion exchange column (4×250 mm). The elution was with 20 mM sodium hydroxide at a flow rate of 0.8 mL/min. Sugars were identified by comparing their retention times with those of standards. Fuc represents fucose; Ara represents arabinose (possibly from a polysaccharide contaminant in the HRP preparation); GlcN represents glucosamine (derived from N-acetylglucosamine); Gal represents galactose; Man represents mannose; Xyl represents xylose.
FIG. 3 represents a mass spectral analysis of HRP and BE-HRP conjugates. Shown are the positive ion mass spectra obtained by the matrix-assisted laser desorption/ionization and time-of flight mass analysis of HRP (panel A), benzoylecgonine hydrazide-HRP conjugates (panel B), and mono-(N-2'-benzoylecgoninoyl)adipic hydrazide-HRP conjugates (panel C). The measured molecular weights for (M+H) + and (M+2H) 2+ ions are indicated.
FIG. 4 demonstrates dot blot analysis of benzoylecgonine-HRP conjugates. The indicated amounts of the benzoylecgonine monoclonal antibody were spotted onto PVDF membranes. After blocking with 1% BSA, the membranes were blotted with BE-HRP conjugates and then visualized with 4-chloro-1-naphthol reagent as described herein. Lane 1 represents a benzoylecgonine hydrazide-HRP conjugate, lane 2 represents a mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide-HRP conjugate, and lane 3 represents a benzoylecgonine-adipic dihydrazide-derivatized HRP conjugate.
FIG. 5 illustrates a schematic diagram for the cross-linking of benzoylecgonine derivatives to proteins.
FIG. 6 illustrates a schematic diagram for the cross-linking of benzoylecgonine derivatives to dyes.
DESCRIPTION OF PREFERRED EMBODIMENTS
Benzoylecgonine conjugates can be used as a diagnostic reagent in immunoassays for the detection of cocaine, for example in illicit drug samples and cocaine and its metabolites in biological fluids. This invention relates to the preparation and characterization of benzoylecgonine conjugates.
The compounds of the present invention are derivatives of cocaine and cocaine metabolites, primarily derivatives of benzoylecgonine. The carboxyl group of benzoylecgonine is modified with hydrazide derivatives to provide a site for attachment to proteins, glycoproteins, polypeptides, carbohydrates, filter paper, polyaccharides, dyes, biotins or the like. The synthesis of the benzoylecgonine conjugates are designed such that they are displaced from the bound proteins, polypeptides, polysaccharide supports, filter papers, or the like, by cocaine or its metabolites.
In general, the benzoylecgonine derivatives of this invention have the following formula: ##STR2## wherein:
R is H or CH 3 ; or
R' is --NH--NH 2 , (NH) 2 CO(CH 2 ) n CONHNH 2 , or related linear chains containing hydrazide functional groups; and
n is an integer of 0 to 20, preferably 1 to 10, and more preferably 1 to 5.
According to the present invention, a targeting substance is a moiety that binds to a defined population of cells. For example, "targeting substance" includes targeting or labeled proteins, peptides, biotins, or the like, capable of binding receptors, enzymatic substances, antigenic determinants, antibodies, or other binding sites present on a target cell population. As used herein, "targeting substance" also includes non-proteinaceous moieties such as dyes.
A conjugate is a hybrid molecule wherein the components are joined by one or more covalent chemical linkages. A conjugate may include, for example, a targeting substance, peptide or protein antigens, detector molecules (enzymes, dyes, antibodies, biotins or the like), or an antibody (i.e., an immunoconjugate).
Conjugates according to the present invention are prepared from the above benzoylecgonine derivatives. The conjugates have the following formula: ##STR3## wherein:
R is as above.
R' is --NH--NH or --(NH)-- 2 CO--(CH 2 )--NH--NH--; and
T is a targeting substance comprising proteins, peptides, polypeptides, dyes, biotins, enzymes, antibodies, carbohydrates, polysaccharide supports, filter paper, etc., or the like.
Polypeptides of the present invention may encompass from about 2 to 1000 amino acid units (usually less than about 120,000 molecular weight). Larger polypeptides are usually called proteins. Some proteins are usually composed of 1 to 20 polypeptide chains, called subunits, which are bound by covalent or non-covalent bonds. Subunits are normally of from 100 to 300 amino acid groups (approximately 10,000 to 35,000 molecular weight). For the purposes of this invention, poly(amino acid) is intended to include individual polypeptide units, or polypeptides which are subunits of proteins, whether composed solely of polypeptide units or polypeptide units in combination with other functional groups, such as porphyrins, as in hemoglobin or cytochrome oxidase.
Various protein types may be employed as the targeting substance, detectors molecule, antigens, etc. These types include albumin, serum proteins, e.g., globulins, ocular lens proteins, lipoproteins, etc. Illustrative proteins include bovine serum albumin, keyhole limpet hemocyanin, egg ovalbumin, bovine γ-globulin, etc. Small natural polypeptides which are immunogenic, such as gramicidin may also be employed. Various synthetic poly(amino acids) may also be employed, such as polymers of lysine, glutamic acid, phenylalanine, tryosine, etc., either by themselves or in combination. Of particular interest is polylysine or a combination of lysine and glutamic acid. Any synthetic polypeptide must contain a sufficient number of active groups, as for example, amino groups provided by lysine.
Various enzymes may be used as the targeting substance, reporter or detector molecules, such as oxidoreductases, hydrolases, lyases, and the like. These enzymes include esterases, amidases, phosphorylases, carbohydrases, peroxidases, oxidases, reductases and the like. Of particular interest are such enzymes as lysozyme, amylase, dehydrogenases, such as malate deydrogenase, lactate dehydrogenase, mannitol-1-phosphate dehydrogenase, and glucose 6-phosphate dehydrogenase, β-glucuronidase, cellulase, and phospho-lipase, particularly horseradish peroxidase. The enzymes will usually have molecular weights in the range of about 1×10 4 to 6×10 5 , more usually in the range of about 1.2×10 4 to 3×10 5 .
Targeting or detector substances useful within the present invention also include antibody and antibody fragments; peptides, such as bombesin, gastrin-releasing peptide, RGD peptide, substance P, neuromedin-B, neuromedin-C, and metenkephalin; and hormones, such as EGF, α- and β-TGF, estradiol, neurotensin, melanocyte stimulating hormone, follicle stimulating hormone, luteinizing hormone, and human growth hormone. Biotin, avidin, proteins corresponding to known cell surface receptors (including low density lipoproteins, transferrin, insulin and CD 4 ), fibrinolytic enzymes, and biological response modifiers (including interleukin, interferon, erythropoietin and colony-stimulating factor) are also suitable targeting substances. Analogs of the above listed targeting substances that retain the capacity to bind to a defined target cell population may also be used within the claimed invention. In addition, synthetic targeting substances may be designed by peptide synthetic or recombinant DNA techniques.
According to the present invention, convenient methods have been developed for the covalent attachment of benzoylecgonine to targeting substances (e.g., proteins, polypeptides, dyes, biotins, enzymes, antibodies, carbohydrates, polysaccharides, filter paper, etc.) through its oligosaccharide chains.
For example, to take advantage of the facile aldehyde-hydrazide condensation reactions at acidic pH to form hydrazones, hydrazide derivatives of benzoylecgonine are synthesized. The hydrazides are purified, characterized and then coupled to targeting substances or detector molecules (e.g., proteins, polypeptides, dyes, biotins, etc.) through appropriate functional groups and to glycoprotein through carbohydrate residues in a site specific manner.
As another example, in a more simplistic approach, the terminal sugar residues in targeting substances or detector molecules (e.g., proteins, glycoproteins, enzymes, antibodies) are derivatized with adipic dihydrazide. A large molar excess of the adipic dihydrazide may be used to ensure that only one end condenses with the aldehyde groups on the carbohydrate moieties of the targeting substance. The hydrazide-derivatized targeting substance is then reacted with the carbodiimide-activated benzoylecgonine under acidic conditions to ensure that the hydrazide moieties rather than amino groups of the polypeptide chain of the targeting substance react with benzoylecgonine. Therefore, it is believed that this approach also gives carbohydrate site-directed coupling.
The presence of covalently bound benzoylecgonine in the benzoylecgonine conjugates may be demonstrated, for example, by dot blot analysis using anti-benzoylecgonine antibodies. The stoichiometry of benzoylecgonine to the targeting substance may be determined reliably by MALDI-MS analysis.
The procedures described herein provide convenient approaches for the preparation of benzoylecgonine conjugates. Approximately 4 to 10 benzoylecgonine residues could be coupled to one mole of the targeting substance by using two of the benzoylecgonine hydrazides described herein. Further, it is possible to obtain benzoylecgonine conjugates containing the desired amounts of benzoylecgonine (in the range of 1 to 10 moles per mole of the targeting substance) by controlling the degree of periodate oxidation and thus the number of sugar residues oxidized.
For example, hydrazide derivatives of benzoylecgonine, e.g., N-2-(t-butyloxycarbonyl) benzoylecgonine hydrazide and mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide, may be synthesized by carbodiimide-activated coupling of benzoylecgonine to N-2-(t-butyloxycarbonyl) hydrazide and adipic dihydrazide, respectively. Removal of the t-butyloxycarbonyl protecting group in N-2-(t-butyloxycarbonyl)benzoylecgonine hydrazide with anhydrous HCl yields benzoylecgonine hydrazide hydrochloride. NMR and high resolution mass spectral analyses demonstrate that the benzoyl group of benzoylecgonine remains intact under the conditions of both carbodiimide coupling and anhydrous HCl treatment. By aldehyde-hydrazide condensation, the hydrazides are covalently conjugated to the carbohydrate residues of horseradish peroxidase (HRP). Dot blot analysis of the conjugates employing antibodies specific to benzoylecgonine demonstrates the presence of bound benzoylecgonine in HRP. The stoichiometry of benzoylecgonine residues to HRP may be determined by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide gives a 2.5 to 3-fold higher coupling compared with benzoylecgonine hydrazide. Conjugates may also be prepared by the coupling of the carbodiimide activated benzoylecgonine to HRP that was derivatized with adipic dihydrazide.
Benzoylecgonine conjugates prepared according to this invention may be routinely used in cocaine detection methodology. The procedures described herein will be valuable to other investigators and for commercial companies for the preparation of benzoylecgonine conjugates of required stoichiometry and for the development of specific and sensitive immunological assays for cocaine detection.
For example, the benzoylecgonine conjugates of the present invention may be utilized in various immunoassays and diagnostic procedures such as those disclosed in U.S. Pat. Nos. 5,233,042 to Beuchler, 5,066,789 to Srinivasan et al., 5,369,007 to Kidwell, 4,197,237 to Lute et al, 5,376,667 to Somers et al. and 3,917,582 to Soffer et al, the entire subject matter of which is hereby incorporated herein by reference.
EXPERIMENTAL EXAMPLE
The following processes were utilized to synthesize benzoylecgonine hydrazide derivatives and benzoylecgonine HRP conjugates of the present invention.
1-Hydroxybenzotriazole (HBT), 1-ethyl-3- 3-(dimethylamino)-propyl!carbodiimide hydrochloride (EDC), adipic dihydrazide, t-butyl carbazate (N-2-t-butyloxycarbonyl hydrazide), dimethylacetamide, dimethyl sulfoxide, N-hydroxysuccinimide (NHS), dicyclohexyl carbodiimide (DCC), sinapinic acid, and silica gel thin-layer plates were purchased from Aldrich Chemical Co. (Milwaukee, Wis.). Biotin hydrazide and 6-biotinamido hexanoic hydrazide (Biotin-LC hydrazide) were obtained from Pierce Chemical Co. (Milwaukee, Wis.). HRP (type VI), 4-chloro-1-naphthol, 4-morpholineethane sulfonic acid (MES) and bovine serum albumin (BSA) were obtained from Sigma Chemical Co. (St. Louis, Mo.). Protein A-purified murine monoclonal antibody (POl-99-11 M-P, 3.39 mg/ml) and a rabbit polyclonal antibody (POl-99-13R-lF, 3.61 mg/ml) that were raised against benzoylecgonine were purchased from Biostride Inc. (Palo Alto, Calif.). Polyvinylidene difluoride (PVDF) membranes were from Millipore (Bedford, Mass.).
Unless otherwise mentioned, drying and concentration of solutions were performed by rotary vacuum evaporation at 30° to 40° C. Compounds on thin-layer chromatograms were visualized by a hand-held UV lamp and/or by exposing to iodine vapor.
IR spectra of compounds in KBr pellets were recorded with a Nicolet 170SX FT-IR spectrometer (Nicolet Instrument Corp., Madison, Wis.) with an on-line 'H- or proton NMR microcomputer data station. 'H-NMR studies were performed with a 270 MHz Nicolet Model NT 270 spectrometer (Nicolet Instrument Corp., Madison, Wis.) coupled to a Tecmeg data system. The spectra were recorded at 24° C. using tetramethylsilane as the internal standard.
Positive ion mode fast atom bombardment mass spectrometry (FAB-MS) analysis was performed with a JEOL SX102 mass spectrometer (JEOL U.S.A., Inc., Peabody, Mass.) using 6 kev xenon atoms as the ionization source. Samples (1 μL of 1 mg/mL solutions in methanol or water) were mixed with 1 μL of Magic Bullet matrix (dithiothreitol:dithioerythritol, 5:1) on the probe tip. Spectra were acquired at a resolution of 3000 and calibrated against an external standard.
High resolution FAB-MS analysis was performed with a JEOL SX102 mass spectrometer as described above at a resolution of 10,000.
For carbohydrate analysis, untreated HRP (10 μg) and periodate-oxidized HRP (10 μg) were hydrolyzed with 400 μL of 2.5M trifluoroacetic acid at 100° C. for 5 hours. The hydrolysates were evaporated in a Speed-Vac and the residues were dissolved in water and analyzed for neutral sugars and hexosamines using a Dionex BioLC system with amperometric detection (Dionex, Sunnyvale, Calif.). Analysis was performed on a CarboPac PAl high-pH anion exchange column (4×250 mm) (Dionex, Sunnyvale, Calif.) at a flow rate of 0.8 mL/min using 20 mM sodium hydroxide.
The following process was used to synthesize benzoyleczonine. To a solution of cocaine hydrochloride (400 mg in 5 ml of ice-cold distilled water) was added 2M sodium hydroxide until the solution was slightly alkaline (pH about 8.0). The cocaine base that precipitated as a white solid mass was recovered by centrifugation at 5000 X g and washed two times with 3 mL of ice-cold water. The pellet was used either directly for the preparation of benzoylecgonine or was lyophilized and stored in a desiccator over solid sodium hydroxide.
The cocaine base (300 mg) was suspended in 10 ml of distilled water and heated under reflux in an oil bath at 90° C. for 18 h. The solution was then concentrated under reduced pressure to 1.5 mL and was then lyophilized. The product was crystallized from hot water and its m.p. determined. Benzoylecgonine was further characterized by IR, H-NMR and high resolution FAB-MS analyses.
The following process was utilized in preparing benzoylecgonine hydrazide hydrochloride. Benzoylecgonine (149 mg, 0.05 mmol), HBT (68 mg, 0.5 mmol) and t-butyl carbazate (66 mg, 0.5 mmol) were dissolved in dimethylacetamide (1.5 mL) and stirred to obtain a clear solution. EDC (97 mg, 0.5 mmol) was added. After stirring overnight at room temperature, water (1.5 mL) was added and the solution was extracted with ethyl acetate (5×2.5 mL). The combined extracts were washed successively with water (8 mL) and saturated saline (8 mL), and then dried over anhydrous magnesium sulfate. The solution was applied to a silica gel (60-200 mesh) column (0.7×15 cm) equilibrated with ethyl acetate:n-hexane (1:1, v/v) and washed with the same solvent (150 ml). The bound N-2-(t-butyloxycarbonyl)benzoylecgonine hydrazide (identified by mass spectral analysis) was eluted with chloroform:methanol (9:1, v/v) and the elution was monitored by TLC using the same solvent. Fractions containing N-2-(t-butyloxycarbonyl)benzoylecgonine hydrazide were combined and evaporated with a yield of 90 mg. The compound was characterized by H-NMR (in CDCl 3 :CD 3 OH, 9:1 v/v) and high resolution FAB-MS analyses.
The N-2-(t-butyloxycarbonyl)benzoylecgonine hydrazide (90 mg) was dissolved in dry ethyl acetate (0.5 mL) and cooled in an ice-bath. To the solution was added cold ethyl acetate (2 mL) saturated with anhydrous HCl. After 30 minutes at room temperature, excess HCl was removed by passing a jet of nitrogen gas through the solution. The resulting benzoylecgonine hydrazide hydrochloride was precipitated with anhydrous ethyl ether, collected by centrifugation, dried in a vacuum desiccator and then characterized by high resolution FAB-MS.
The following process was utilized in synthesizing mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide. Benzoylecgonine (100 mg, 0.34 mmol), HBT (45 mg, 0.34 mmol) and adipic dihydrazide (232 mg, 1.32 mmol) were suspended in a mixture of dimethylacetamide (5 mL) and dimethyl sulfoxide (5 mL). The mixture was stirred for 30 minutes at room temperature. To the cloudy solution, EDC (97 mg, 0.5 mmol) was added and the mixture stirred overnight at room temperature. Water (20 mL) was added and the solution was extracted with ethyl acetate (5×20 mL). The aqueous phase was then deionized with AG 4×4 (free base) ion exchange resin and lyophilized. The solid was dispersed in ethanol and stirred for 2 hours to obtain a fine suspension and centrifuged. The precipitate contained unreacted adipic dihydrazide and was discarded. The ethanol solution was chromatographed on a silica gel column (1×15 cm) using ethanol:water (85:15, v/v). Fractions (2 mL) were collected and analyzed by TLC using the above solvent. Mass spectral analysis demonstrated that the desired compound, mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide, was eluted in fractions 10 through 25 along with significant amounts of other compounds. The product, mono-(N-2'-benzoylecgoninoyl) adipic dihydrazide (R f value relative to adipic dihydrazide=0.27) was purified (yield, 49 mg) by preparative TLC using ethanol:water (85:15, v/v) and characterized by high resolution FAB-MS.
The following process was utilized for conjugation of benzoylecgonine hydrazides to HRP. To a solution of HRP (2.4 mg) in 50 mM sodium acetate (2.16 mL), pH 5.0 at 4° C., was added 100 mM sodium metaperiodate in 50 mM sodium acetate (0.24 mL), pH 5.0. The solution was allowed to stand at 4° C. for 30 minutes in the dark, dialyzed against 50 mM sodium acetate, pH 5.0 (24 hours, several changes) and then concentrated to 0.6 mL using a Centricon-10 centrifugal microconcentrator (Amicon, Danvers, Mass.). Benzoylecgonine hydrazide hydrochloride (3.8 mg in 100 μL of water, 200-fold molar excess) was added and allowed to react at room temperature for 4 hours. The solution was then dialyzed against 50 mM sodium phosphate, pH 7.2. Mono-(N-2'-benzoylecgoninoyl) adipic dihydrazide, biotin hydrazide and biotin-LC hydrazide were conjugated similarly to the carbohydrate residues of HRP.
The following process was utilized for direct conjugation of benzoylecgonine to adipic dihydrazide-derivatized HRP. HRP (2 mg) was oxidized with periodate as described above and dialyzed against 50 mM sodium acetate, pH 5.0. The solution was concentrated (final volume 1 mL) using a Centricon-10 microconcentrator, treated with adipic dihydrazide (1.8 mg in 100 μL of 50 mM sodium acetate, pH 5.0) and allowed to react at room temperature for 4 hours. The solution was dialyzed against 100 mM MES acid, pH 4.7 and then concentrated to 400 μL using a Centricon-10 microconcentrator. In a separate test tube, EDC (5.0 mg in 100 μL of 100 mM MES, pH 4.7) was added to a solution of benzoylecgonine (2.5 mg in 100 μL of 100 mM MES, pH 4.7) and allowed to react at room temperature. After 10-15 minutes, adipic dihydrazide-modified HRP was added to EDC-activated benzoylecgonine and allowed to react at room temperature. Aliquots (200 μL) of this solution drawn at 30 minutes, 1 hour and 2 hours were dialyzed extensively against 20 mM sodium phosphate, pH 7.4, and analyzed by MALDI-MS.
The following process was utilized for dot blot analysis of benzoylecgonine-HRP conjugates. The benzoylecgonine residues covalently bound to HRP were identified by dot blot analysis using mAb and a polyclonal antibody that are specific to benzoylecgonine. The benzoylecgonine antibodies (amounts ranging from 4 μg to 0.03 μg per spot) were spotted on PVDF membranes using a dot blot apparatus. The membranes were either stained with Amido black to visualize the amounts of applied antibody (data not shown) or blocked with a 1% solution of BSA in 10 mM Tris-HCl, 150 mM NaCl, pH 8.0 at room temperature for 2 hours. The blocked membranes were treated with BE-HRP (4 μg/ml) in 50 mM Tris-HCl, 150 mM NaCl, pH 8.0 containing 0.05% Tween 20 at room temperature for 1 hour. The membranes were washed 3-4 times with 50 mM Tris-HCl, 150 mM NaCl, pH 8.0 containing 0.05% Tween 20 to remove unbound BE-HRP and then treated with 4-chloro-1-naphthol reagent. After 5-10 minutes of color development, the membranes were washed with excess distilled water.
The following process was used for mass spectrometry analysis of benzoylecgonine-HRP and biotin-HRP conjugates. MALDI-MS of the conjugates was performed using a Kratos MALDI III mass spectrometer (Shimadzu Scientific Instruments, Columbia, Md.) operated in a linear mode at an accelerating voltage of 22 kev with detection of positive ions. Conjugates (5-10 μM in 0.5 μL of water) were placed on the sample slide and sinapinic acid (0.8 μl of 10 mg/mL solution in 50% aqueous acetonitrile, 0.05% trifluoroacetic acid) was added. The slide was then dried in a vacuum desiccator for 10 minutes. Desorption/ionization was accomplished by a nitrogen UV laser (337 nm). 100 scans were accumulated over a 2 mm stripe across the sample spot. The instrument was calibrated against BSA as an external standard ((M+H) + =66431 and (M+2H) 2+ =33216).
The following process was utilized for the analysis of benzoylecgonine. Benzoylecgonine was prepared by heating aqueous solution of cocaine base under optimal reaction conditions to obtain quantitative conversion without any degradation. FAB-MS analysis showed that the (M+H) + ion of cocaine (304 amu) completely disappeared while a new (M+H) + ion of benzoylecgonine (290 amu) appeared. The quantitative conversion of cocaine to benzoylecgonine was further demonstrated by IR and NMR analyses. Benzoylecgonine showed IR absorption peaks at 1631 cm -1 (carboxylic group), 1724 cm -1 (aryl ester carbonyl) and 3450 cm -1 (broad, carboxylic --OH), whereas cocaine gave absorption peaks at 1737 cm -1 (methyl ester carbonyl) and 1710 cm -1 (aryl ester carbonyl). The 'H-NMR (or proton-NMR) (in CDCl 3 ) of benzoylecgonine contained resonance signals at δ8.20-7.31 (5H, m, --C 6 H 5 ) and 2.58-2.44 (3H, s, --NCH 3 ); the methyl ester resonance at δ3.85-3.66 (3H, s, --COOCH 3 ) that was observed for cocaine was absent. Upon recrystallization from hot water, benzoylecgonine was obtained as white needles with a m.p. of 88°-90° C. (lit. 86°-92° C.). High resolution mass spectral analysis of the purified product gave (M+H) + ion at 290.1388 (calc. 290.1392, C 16 H 20 NO 4 ).
The following process was utilized for analysis of benzoylecgonine hydrazide. To accomplish a facile conjugation of benzoylecgonine to HRP by aldehyde-hydrazide condensation reaction, two hydrazide derivatives of benzoylecgonine were synthesized and characterized. The carbodiimide-activated benzoylecgonine was reacted with t-butyloxycarbonyl hydrazide using HBT as a catalyst to obtain N-2-t-butyloxycarbonylbenzoylecgonine hydrazide (FIG. 1) in 58% yield. The product was purified on a silica gel column and characterized by NMR and FAB-MS. 'H-NMR (or proton NMR) analysis showed resonance signals at δ9.32-8.27 (2H, b, --CONH--NHCO--O--t--Bu), 1.76-106 (9H, s, --O--C(CH 3 ) 3 ) and 8.24-7.06 (5H, m, --CO--C6H 5 ). These results demonstrated that the benzoyl ester moiety remained intact under the reaction conditions employed for hydrazide formation. High resolution FAB-MS analysis gave (M+H) + ion at 404.2169 (calc. 404.2185, C 21 H 30 N 3 O 5 ).
The protective t-butyloxy group in N-2-(t-butyloxycarbonyl)benzoylecgonine hydrazide was removed with anhydrous HCl and the product, benzoylecgonine hydrazide hydrochloride, was obtained in almost quantitative yield. High resolution FAB-MS analysis gave (M+H) + at 304.1622 (calc. 304.1661, C 16 H 22 N 3 O 3 ). The following process was utilized for analysis of mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide. The observed coupling efficiency of benzoylecgonine to periodate-oxidized HRP was much lower than that expected considering the number of available aldehyde groups (see below) and the ease of aldehyde-hydrazide condensation. This is presumably due to steric hindrance from the bulky benzoyl group on the adjacent carbon atom. To overcome this disadvantage, an adipic acid spacer arm-containing hydrazide was synthesized. Carbodiimide-activated benzoylecgonine was condensed with adipic dihydrazide using HBT as a catalyst. The product, mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide, was obtained in about 32% yield after purification by ethanol precipitation to remove unreacted adipic dihydrazide followed by silica gel chromatography and preparative TLC. FAB-MS showed (M+H) + and (M+Na) + ions at 446 amu and 468 amu, respectively. High resolution mass spectral analysis gave (M+H) + at 446.2381 (calc. 446.2403, C 22 H 32 N 5 O 5 ).
The following process was used for analysis of the conjugation of benzoylecgonine hydrazides to the carbohydrate moieties of HRP. HRP contains 8 N-linked oligosaccharides with Xyl(Man) 2 Man(Fuc)GlcNAc 2 -- structures. The fucose, xylose, and two out of three mannose residues of each HRP oligosaccharide structure are amenable to periodate oxidation. In all, there are approximately 32 unsubstituted terminal sugar residues that can potentially be oxidized by periodate. Generally, periodate oxidation of glycoproteins to generate aldehyde groups on terminal hexoses are performed using 10 to 20 mM periodate for 30 to 40 minutes in the dark. In the present invention, HRP was oxidized with periodate under relatively mild conditions to generate aldehyde groups on the terminal sugar residues. The carbohydrate compositional analysis of the periodate-oxidized HRP demonstrated that approximately 80% of fucose, and about 50% of combined mannose and xylose (FIG. 2) were oxidized. From this result, it is estimated that about 18 sugar residues of HRP were oxidized.
On average only 4 moles of benzoylecgonine hydrazide were coupled to 1 mole of HRP even though a 100 to 200-fold (10-150-fold can also be used) molar excess of the hydrazide was used. MALDI-MS analysis showed that the molecular weight of HRP was increased by 989 and 1207 (respectively, 3.5 and 4.2 moles of benzoylecgonine per mole of HRP) in two different preparations of BE-HRP (FIG. 3, panel B and data not shown). Considering that as many as 36 aldehyde groups were generated on periodate oxidation of HRP (see above) and that the hydrazide-aldehyde additions are facile, the low efficiency of conjugation of benzoylecgonine hydrazide to HRP is likely due to the steric hindrance caused by the neighboring bulky benzoyl moiety. Supporting this conclusion, the DCC-activated benzoylecgonine failed to form a succinimidyl ester with NHS even after a prolonged reaction. However, FAB-MS of the reaction mixture indicated that a stable benzoylecgonine-DCC adduct was formed ((M+H) + =496).
The amount of mono-(N-2'-benzoylecgoninoyl)adipic dihydrazide that coupled to periodate-oxidized HRP was 2.5 to 3-fold higher compared with benzoylecgonine hydrazide. MALDI-MS analysis demonstrated that, after conjugation of mono-(N-2'benzoylecgoninoyl)adipic dihydrazide, the molecular weight of HRP increased by 4536 (10.6 moles of benzoylecgonine residues per mole of HRP) in one of the BE-HRP preparations (FIG. 3, panel C). This result, taken together with those described above, suggests that the steric hindrance caused by the benzoyl group can be considerably minimized by introducing a spacer arm and, thus, more benzoylecgonine residues may be coupled to HRP.
The coupling of two commercially available hydrazides, biotin hydrazide and biotin-LC hydrazide, to periodate-oxidized HRP was studied to determine whether the length of the spacer arm is critical for efficient conjugation. It was concluded that any difference in coupling efficiency between these two compounds must be related to the steric effect exerted by the bulky fused ring system. The molecular weight of HRP was shifted by 1559 and 2885 after conjugation with biotin hydrazide and biotin-LC hydrazide respectively, as demonstrated by MALDI-MS analysis (data not shown). These molecular weight shifts correspond to coupling of 6.5 moles of biotin hydrazide and 8.2 moles of biotin-LC hydrazide to HRP. The data suggest that the additional spacer arm in biotin-LC hydrazide has a significant contribution toward the coupling efficiency. From these data, it was inferred that a longer spacer arm, such as the one used in this invention, optimizes coupling of benzoylecgonine to periodate-oxidized HRP.
The following process was utilized in the conjugation of benzoylecgonine to adipic dihydrazide-derivatized HRP. This method involves in situ conjugation of EDC-activated benzoylecgonine to adipic dihydrazide-derivatized HRP was also conducted. In this approach, periodate oxidized-HRP was first reacted with adipic dihydrazide. MALDI-MS analysis of the product revealed that as many as 15-17 adipic dihydrazide molecules (approximately 2 residues per oligosaccharide chain of HRP) were coupled to 1 mole of HRP (data not shown). The coupling did not increase with further increase in reaction time, suggesting that each oligosaccharide chain of HRP can accommodate no more than two adipic dihydrazide residues, even though considerably more aldehyde groups are available (see above). The resultant adipic dihydrazide-derivatized HRP was then allowed to react with the carbodiimide-activated benzoylecgonine. MALDI-MS analysis of the reaction mixture at different time intervals indicated that the coupling of benzoylecgonine residues to HRP was essentially complete within 30 minutes. Approximately 2.5 to 3 moles of benzoylecgonine were coupled to 1 mole of HRP (data not shown). The primary amine groups of the adipic dihydrazide side chain in the derivatized HRP are not protonated at pH 4.7 (pK a of a hydrazide is about 2.6) and, thus, they are expected to react preferentially with carbodiimide-activated benzoylecgonine. On the other hand, the lysine side chain and amino terminal primary amino groups of HRP are highly protonated and, consequently, they should not form amide bonds with benzoylecgonine. Therefore, it is likely that the coupling of carbodiimide-activated benzoylecgonine to adipic dihydrazide-derivatized HRP is to the carbohydrate-linked hydrazide groups, rather than directly to the polypeptide.
The following process was utilized in the analysis for the identification of benzoylecgonine residues bound to HRP. The BE-HRP conjugates were analyzed for their ability to bind a mouse mAb against benzoylecgonine (FIG. 4). The HRP conjugates of the benzoylecgonine hydrazides and those prepared by coupling benzoylecgonine to the adipic dihydrazide-modified HRP were able to detect as little as 30-60 ng of the mAb. Similar results were obtained by dot blot analysis using a polyclonal rabbit anti-benzoylecgonine IgG (data not shown). These results demonstrate that benzoylecgonine is covalently coupled to HRP and that the HRP activity is retained.
A variety of other functional groups can be introduced to the two hydrazide derivatives of benzoylecgonine so that these can be cross-linked (conjugated) to proteins, biotins or dyes. These benzoylecgonine cross-linked (conjugated) proteins or dyes are useful for diagnostic applications.
EXAMPLES 1-4
These examples set forth benzoylecgonine hydrazide derivatives containing easy leaving groups such as halogen.
Example 1 ##STR4## wherein X is Cl, Br, or I.
Example 2 ##STR5## wherein n is CL, Br, or I;
R' is NaSO 3 or H; and
R and X are as above.
Example 3 ##STR6## wherein R', X and R are as above.
Example 4 ##STR7## wherein R', R and X are as above.
Examples 5-8
The following examples set forth benzoylecgonine hydrazide derivatives containing SH or protected SH groups.
Example 5 ##STR8## wherein R is as above.
Example 6 ##STR9## wherein R' and R are as above.
Example 7 ##STR10## wherein R, R' and n are as above.
Example 8 ##STR11## wherein R is as above.
Examples 9-12
The following examples set forth benzoylecgonine hydrazide derivatives containing electrophilic centers.
Example 9 ##STR12## wherein R, R' and n are as above.
Example 10 ##STR13## where R and R' are as above.
Example 11 ##STR14## wherein R, R' and n are as above.
Example 12 ##STR15## wherein R and n are as above.
Examples 13-16
The following examples set forth benzoylecgonine hydrazide derivatives containing aldehyde groups.
Example 13 ##STR16## wherein R and R' are as above.
Example 14 ##STR17## wherein R, R' and n are as above.
Example 15 ##STR18##
Example 16 ##STR19## wherein R is as above and R" is H 2 trityl group or related protecting groups.
Examples 17-18
The following examples set forth direct derivatization of benzoylecgonine using the same chemistry as that was used for hydrazides preparation.
Example 17 ##STR20## wherein R and n are as above.
Example 18 ##STR21## wherein R and n are as above; and
R" is H, a Trityl group or related protecting groups.
Examples 19-24
The following examples set forth derivatization of proteins for benzoylecgonine cross-linking. Such proteins include, for Example, Keyhole Limpet Hemocyanin (KLH), Bovine Serum Albimum (BSA), Horseradish Peroxidase (HRP), Alkaline Phosphatase (AP), antibodies, enzymes, glycoproteins, polysaccharides, filter paper or the like.
Example 19 ##STR22## wherein P is KLH, BSA, HRP, AP, antibody, glycoprotein, filter paper, polysaccharide, etc.
Example 20 ##STR23## wherein P, R' are as above.
Example 21 ##STR24## wherein P, R' and n are as above.
Example 22 ##STR25## wherein P, R' and n are as above.
Example 23 ##STR26## wherein P and R' are as above.
Example 24 ##STR27## wherein P and R' are as above.
Examples 25-27
The following examples set forth conjugation of benzoylecgonine to dyes.
Example 25 ##STR28## wherein R is the same as above.
Example 26 ##STR29## wherein R is the same as above.
Example 27 ##STR30## wherein R and R' are the same as above.
Examples 28-30
The following examples set forth conjugation of benzoylecgonine to biotins.
Example 28
R--CONHNH.sub.2 +HOOC˜Biotin→RCONHNHCO--Biotin
wherein R is as above.
Example 29 ##STR31## wherein X, R and R' are as above.
Example 30 ##STR32## where R and n are as above. | A benzoylecgonine conjugate represented by the following formula: ##STR1## wherein, R is H or CH 3 ; R' is --NH--NH--, --(NH) 2 --CO--(CH 2 ) n --CO--NH--NH--, or related linear chains wherein at least one (CH 2 ) is replaced with a substituent selected from the group consisting of an ether, an amide, a sulfide, a disulfide, an alkyl, an aryl, an alkoxy, an aryloxy or an alkylhalide; and T is a targeting substance selected from the group consisting of proteins, peptides, antigens, polypeptides, dyes, biotins, enzymes, antibodies, hormones, carbohydrates, polysaccharide supports, and filter paper. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of invention relates to business card filing structure, and more particularly pertains to a new and improved business card filing organization wherein the same is arranged to provide for pocket structure relative to a filing member to house business cards therewithin.
2. Description of the Prior Art
The wide spread contemporary use of business cards for information is present in the prior art, wherein filing systems to support business card members have been heretofore presented in the U.S. Pat. No. 4,963,049 to Pearson having an elongate strip of material accommodating a business card thereon.
U.S. Pat. No. 4,905,392 to Klein sets forth an adhesive backed business card for mounting to a file card.
U.S. Pat. No. 4,930,928 to Ristuccia, Sr. sets forth a business card plate having slots to receive a business card thereon, and similarly U.S. Pat. No. 4,849,056 to Ristuccia, Sr. sets forth a similar type organization.
Accordingly, it may be appreciated that there continues to be a need for a new and improved business card filing organization as set forth by the instant invention which addresses both the problems of ease of use as well as effectiveness in construction in accommodating in a releasable manner various business card components and in this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of business card filing structure now present in the prior art, the present invention provides a business card filing organization wherein the same is arranged to selectively mount business cards. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved business card filing organization which has all the advantages of the prior art business card filing structure and none of the disadvantages.
To attain this, the present invention provides a rotary filing system arranged to include a plurality of card holders, with each card holder including at least a forward transparent window arranged to coextensively extend over a pocket to receive a business card. A modification of the invention includes readily mounted tab and marking structure to indicate various categorizing of the business cards mounted within the structure.
My invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this particular combination of all of its structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the Public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved business card filing organization which has all the advantages of the prior art business card filing structure and none of the disadvantages.
It is another object of the present invention to provide a new and improved business card filing organization which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved business card filing organization which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved business card filing organization which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such business card filing organizations economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved business card filing organization which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is an isometric illustration of the instant invention.
FIG. 2 is an orthographic frontal view, taken in elevation, of a card holder of the invention.
FIG. 3 is an orthographic frontal view of the card holder illustrating the use of an associated tab plate arranged for selective mounting thereto.
FIG. 4 is an enlarged orthographic view of section 4 as set forth in FIG. 3.
FIG. 5 is an isometric illustration of the card holder structure having entrances at either end thereof.
FIG. 6 is an orthographic view of the card holder structure including an indicator plunger member.
FIG. 7 is an orthographic view, partially in section, of section 7 as set forth in FIG. 6.
FIG. 8 is an isometric illustration of the card holder structure as set forth in FIG. 6 in use for a marking procedure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 to 8 thereof, a new and improved business card filing organization embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
More specifically, the business card filing organization 10 of the instant invention essentially comprises a support rack 11 having a rotary dial 12 mounting a rotary axle 13 thereto. The rotary axle 13 includes a plurality of annular support bands 14 concentrically mounted about the support axle in a fixed relationship, with the support bands spaced apart a predetermined spacing. A plurality of card holders 15 are arranged for mounting to the support bands 14 to a support tab 22 mounted to a bottom frame rail 20 of the frame 18. The frame 18, as illustrated in the FIG. 2 for example, includes a U-shaped configuration having top, bottom, and a side rail 19, 20, and 21 respectively. The bottom frame rail 20 includes the support tab 22 having T-shaped slots 23 that are spaced apart the predetermined spacing to receive the support bands 14 therewithin. The card holder 15 includes at least a transparent forward wall 16, and optionally a transparent rear wall 17, that are arranged in a parallel coextensive relationship relative to one another. In this manner, a pocket 24 is defined between the forward and rear walls 16 and 17 and include respective forward and rear thumb recesses 26 and 27 that are coextensively directed into right side edges of the forward and rear walls 16 and 17 to accommodate a business card 25 within a pocket 24 defined between the forward and rear walls 16 and 17.
The FIG. 3 illustrates the use of a tab plate 33 having positioning legs 29 fixedly and orthogonally directed downwardly relative to the tab plate 33. Each positioning leg 29 includes a leg lower pointed conical end 30 having a ledge 31 at an inner face between the conical end 30 and the leg 29, with the ledge 31 arranged substantially orthogonally relative to an axis of the leg 29. A glue ring 32 having a frangible shell containing a fluid glue therewithin is mounted on the ledge and is accordingly ruptured upon projection of the legs 29 within the associated receiving bores 28 that are orthogonally directed through the top rail 19. In this manner, a business card 25 is fixedly secured within the associated pocket 24 to prevent displacement or movement thereof relative to the pocket structure.
The FIGS. 5 and 6 for example illustrate the use of thumb recesses 26 mounted into opposed sides of the card holder 15 for ease of access to the card structure 25 to each side of the pocket structure, as opposed to having entrance to the pocket 24 through only a right side of the card holder 15.
The FIGS. 6-8 illustrate the use of a plunger 34 reciprocatably mounted orthogonally through the top rail 19 having a plunger shank 34a received within a top frame rail cavity 35. The plunger shank 34a includes a plunger shank piercing tip 39 at a lower distal end of the plunger shank positioned above a dye capsule 36. The dye capsule 36 is mounted to a cavity floor 37 of the cavity 35. The cavity floor 37 includes a plurality of apertures 38 directed therethrough in communication with the pocket 24, whereupon projection of the plunger 34 downwardly into the cavity 35 effects projection of the indicator dye 40 contained within the dye capsule 36 into the cavity to coat an associated business card to note relative importance of the business card. In this manner, various translucent fluid dye 40 may be utilized for such purpose of various coloration for notation of various significance of business cards 25 positioned within each card holder 15.
As to the manner of usage and operation of the instant invention, the same should be apparent from the above disclosure, and accordingly no further discussion relative to the manner of usage and operation of the instant invention shall be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A rotary filing system is arranged to include a plurality of card holders, with each card holder including at least a forward transparent window arranged to coextensively extend over a pocket to receive a business card. A modification of the invention includes readily mounted tab and marking structure to indicate various categorizing of the business cards mounted within the structure. | 1 |
FIELD OF THE INVENTION
This invention relates to the field of integrated circuits. More particularly, this invention relates to methods to improve pattern alignment to buried layers.
BACKGROUND OF THE INVENTION
Integrated circuits (ICs) frequently have buried layer conductive elements, such as n-type buried layers under circuits to reduce latchup. Such buried conductive elements are typically several microns below the surface of the IC substrate. Surface elements, such as deep wells, extend from the substrate surface and connect to the buried conductive elements. It is important that photolithographic patterns to define surface elements be aligned with the buried elements. Alignment of patterns with buried layers is difficult, due to a lack of clear features from the buried layers that are visible at the surface of the substrate. As lateral dimensions of structures in ICs shrink, as articulated by Moore's Law, the difficulty of alignment increases. Verification of alignment is a costly, time consuming and destructive process involving cross-sectioning a pilot wafer and measuring the alignment with a Scanning Electron Microscope (SEM).
SUMMARY OF THE INVENTION
This Summary is provided to comply with 37 C.F.R. §1.73, requiring a summary of the invention briefly indicating the nature and substance of the invention. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
A method of measuring the lateral offset between a pattern for a surface component of an integrated circuit and a buried layer under an epitaxial layer in the integrated circuit, know as the epi pattern shift, using planar processing technology and commonly used semiconductor fabrication metrology tools is disclosed. The disclosed method may be used on a pilot wafer to provide optimization data for a production line running production wafers, or may be used on production wafers directly. An integrated circuit fabricated using the instant invention is also disclosed.
DESCRIPTION OF THE VIEWS OF THE DRAWING
FIGS. 1A through 1Q are depictions of the process flow for a pilot wafer embodying the instant invention.
FIG. 2A and FIG. 2B are top views of a wafer fabricated according to another embodiment of the instant invention.
FIG. 3 is a cross-section of an integrated circuit containing MOS transistors, a buried collector bipolar transistor and an n-type buried layer monitor according to an embodiment of the instant invention.
DETAILED DESCRIPTION
The present invention is described with reference to the attached figures, wherein like reference numerals are used throughout the figures to designate similar or equivalent elements. The figures are not drawn to scale and they are provided merely to illustrate the invention. Several aspects of the invention are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the invention. One skilled in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operations are not shown in detail to avoid obscuring the invention. The present invention is not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the present invention.
For the purposes of this disclosure, the terms “N-type Buried Layer,” (NBL), and “Diffusion Under Film,” (DUF), are both taken to refer to an n-type region that is formed in a p-type integrated circuit substrate under a p-type epitaxial layer on the IC substrate. Polysilicon will be understood to mean poly crystalline silicon. Choline refers to an aqueous solution of choline hydroxide, C 5 H 14 NO(OH), typically 3 to 10 percent in concentration.
The instant invention encompasses several embodiments. In a first embodiment, a pilot wafer undergoes a process sequence which enables a measurement of an epi pattern shift on commonly used semiconductor processing metrology equipment. FIGS. 1A through 1P are depictions of steps in the process sequence for a pilot wafer embodying the instant invention.
FIG. 1A is a cross-section of a pilot wafer after a process operation known as first oxide formation. Pilot wafer ( 100 ) includes two regions; an IC region ( 102 ) is reserved for fabricating ICs, and an epi pattern shift monitor region ( 104 ) is reserved for alignment marks related to an n-type buried layer and an n-well implant pattern. A single crystal substrate ( 106 ), typically p-type silicon, has a first oxide ( 108 ), typically silicon dioxide several hundred nanometers thick, deposited or grown on a top surface, typically by furnace oxidation.
FIG. 1B is a cross-section of the wafer ( 100 ) with a photoresist pattern ( 110 ), sometimes called an NBL pattern, on a top surface of the first oxide ( 108 ) to define regions for an n-type buried layer. Both the IC region ( 102 ) and the epi pattern shift monitor region ( 104 ) have regions defined for the n-type buried layer.
FIG. 1C is a cross-section of the wafer ( 100 ) with the NBL pattern ( 110 ), after an oxide etch process operation, known as a DUF Dry Etch. Portions of the first oxide ( 108 ) in the regions defined for the n-type buried layer by the NBL pattern ( 110 ) have been removed by the oxide etch process, exposing a top surface of the substrate ( 106 ).
FIG. 1D is a cross-section of the wafer ( 100 ) during an ion implantation process operation, known as NBL implant. The photoresist of the NBL pattern has been removed prior to this operation. N-type dopant ions ( 112 ), typically antimony, are implanted into a top portion of the substrate ( 106 ) in regions defined by the open regions in the first oxide ( 108 ), to form an as-implanted n-type layer ( 114 ).
FIG. 1E is a cross-section of the wafer ( 100 ) after an anneal operation, known as a DUF diffusion, to reduce damage to the substrate by the n-type dopants that were implanted, as discussed in reference to FIG. 1D . A layer of silicon dioxide ( 116 ) has grown in exposed regions on the top surface of the substrate ( 106 ). The n-type region ( 118 ) has expanded during the anneal operation by diffusion of the dopant atoms.
FIG. 1F is a cross-section of the wafer ( 100 ) after a process operation, known as nitride deposition, to deposit silicon nitride on a back surface of the wafer ( 100 ). A silicon nitride layer ( 120 ) has been formed on the back surface of the wafer. Similarly, a silicon nitride layer ( 122 ) has been formed on a top surface of the first oxide ( 108 ) and a top surface of the oxide ( 116 ) grown during the anneal operation discussed in reference to FIG. 1E .
FIG. 1G is a top view of the wafer ( 100 ) showing relative locations of IC regions ( 102 ) and the epi pattern shift monitor region ( 104 ), after a photolithographic operation to cover the epi pattern shift monitor region ( 104 ) with photoresist ( 124 ). It is within the scope of the instant invention to locate the epi pattern shift monitor region ( 104 ) in any site on the front surface of the wafer ( 100 ). It is also within the scope of the instant invention to have a plurality of regions reserved for epi pattern shift monitoring.
FIG. 1H is a cross-section of the wafer ( 100 ) after the photolithographic operation to cover the epi pattern shift monitor region ( 104 ) with photoresist ( 124 ), discussed above in reference to FIG. 1G . Photoresist ( 124 ) covers the region reserved for the epi pattern shift monitor.
FIG. 1I is a cross-section of the wafer ( 100 ) after an operation known as a nitride etch operation. Silicon nitride on the front surface of the wafer ( 100 ) has been removed except where masked in the epi pattern shift monitor region ( 104 ) by the photoresist applied in the photolithographic operation discussed in reference to FIG. 1H and FIG. 1G . After the silicon nitride was etched, the photoresist was removed.
FIG. 1J is a cross-section of the wafer ( 100 ) after an operation known as an oxide etch operation. During this operation, the first oxide ( 108 ) and the oxide ( 116 ) grown during the anneal operation discussed in reference to FIG. 1E were removed from the front surface of the wafer ( 100 ), except where masked in the epi pattern shift monitor region ( 104 ) by the silicon nitride ( 122 ).
FIG. 1K is a cross-section of the wafer ( 100 ) after an epitaxial layer growth operation. An epitaxial layer of single crystal p-type silicon ( 126 ), typically several microns thick, has been grown on the top surface of the substrate ( 106 ), except where masked in the epi pattern shift monitor region ( 104 ) by oxide ( 108 , 116 ) and silicon nitride ( 122 ). During the epitaxial layer growth operation, polysilicon is grown on a top surface of the silicon nitride ( 122 ). N-type dopants from the n-type regions ( 118 ) diffuse into the epitaxial layer ( 126 ) during its growth to form an expanded n-type buried layer ( 130 ), except where masked in the epi pattern shift monitor region ( 104 ) by oxide ( 108 , 116 ) and silicon nitride ( 122 ).
FIG. 1L is a cross-section of the wafer ( 100 ) after a deposition of an oxide layer, known as an Nwell oxide. An Nwell oxide layer ( 132 ), typically silicon dioxide, is deposited, typically by a plasma process, on a top surface of the epitaxial layer ( 126 ) and a top surface of the polysilicon layer ( 128 ).
FIG. 1M is a top view of the wafer ( 100 ) after a photolithographic operation to expose the epi pattern shift monitor region ( 104 ) while covering the IC regions ( 102 ) with photoresist ( 134 ).
FIG. 1N is a cross-section of the wafer ( 100 ) after the photolithographic operation to expose the epi pattern shift monitor region ( 104 ) while covering the IC regions ( 102 ) with photoresist ( 134 ), discussed above in reference to FIG. 1M . Photoresist ( 134 ) covers the regions reserved for ICs. Nwell Oxide ( 132 ) over polysilicon ( 128 ) is exposed.
FIG. 1O is a cross-section of the wafer ( 100 ) after an Nwell oxide etch process. Portions of Nwell oxide layer ( 132 ) have been removed in the epi pattern shift monitor region ( 104 ), where not masked by the photoresist applied in the photolithographic operation discussed in reference to FIG. 1M and FIG. 1N . The polysilicon ( 128 ) is exposed after the Nwell oxide etch process.
FIG. 1P is a cross-section of the wafer ( 100 ) after a choline etch. Wafer ( 100 ) is exposed to a choline wet etch, which removes the polysilicon over the silicon nitride ( 122 ). The epitaxial layer ( 126 ) is protected from the choline etch by the Nwell oxide layer ( 132 ). The silicon nitride ( 122 ) is exposed after the choline etch.
FIG. 1Q is a cross-section of the wafer ( 100 ) after a photolithographic operation to define regions for an n-type ion implant, known as an n-well implant. An n-well implant pattern generated by this photolithographic operation must be aligned to the n-type buried layer ( 118 ). It is an embodiment of the instant invention that the lateral misalignment of the n-well implant pattern to the n-type buried layer may be measured on commonly used semiconductor processing metrology equipment. Photoresist of the n-well pattern ( 136 ) is present on a top surface of the Nwell oxide ( 132 ) in the IC regions ( 102 ) and on the top surface of the silicon nitride ( 122 ). Commonly used semiconductor processing metrology equipment can measure and report a right NBL to n-well pattern spacing ( 138 ) and a left NBL to n-well pattern spacing ( 140 ). An epi pattern shift value may be computed using the following expression:
Epi pattern shift = ( right NBL to nwell spacing ) - ( left NBL to nwell spacing ) 2 ( 1 )
The value of the epi pattern shift obtained from EQN. 1 is used to adjust the photolithographic operation to generate the pattern for the n-well to optimize the alignment to the n-type buried layer. This embodiment is advantageous because the time and cost to measure the epi pattern shift is much less than commonly used procedures such as cross-sectioning followed by examination in a scanning electron microscope (SEM).
In another embodiment, an n-well pattern may be aligned directly to an n-type buried layer pattern monitor on a wafer, and the wafer may be continued through an IC fabrication process sequence to produce completed ICs in which n-well to n-type buried layer alignment is optimized. FIG. 2A and FIG. 2B depict a wafer with a plurality of regions reserved for n-type buried layer pattern monitors.
FIG. 2A depicts a wafer ( 200 ) with a plurality of regions ( 202 ) reserved for ICs and a plurality of regions ( 204 ) reserved for n-type buried layer pattern monitors. The wafer ( 200 ) has been through the following process operations, similar to those discussed in reference to FIGS. 1A through 1F above, including first oxide formation, n-buried layer pattern, DUF wet etch, NBL implant, DUF diffusion and backside nitride deposition. After the backside nitride deposition operation, the wafer ( 200 ) undergoes a photolithographic operation to cover the n-type buried layer pattern monitor regions ( 204 ) with photoresist ( 206 ). It is within the scope of the instant embodiment to have a number of regions ( 204 ) reserved for n-type buried layer pattern monitors that is less than, equal to, or greater than the number of regions ( 202 ) reserved for ICs. The wafer ( 200 ) undergoes a nitride etch operation, similar to that discussed in reference to FIG. 1I . After the nitride etch operation is complete, regions ( 204 ) reserved for n-type buried layer pattern monitors have a silicon nitride layer over them, due to masking by the photoresist, while regions ( 202 ) reserved for ICs have no silicon nitride over them. The wafer ( 200 ) undergoes an oxide etch operation, similar to that discussed in reference to FIG. 1J . After the oxide etch operation is complete, regions ( 204 ) reserved for n-type buried layer pattern monitors have a silicon nitride layer and silicon dioxide layer over them, due to masking by the silicon nitride, while regions ( 202 ) reserved for ICs have no silicon dioxide over them. The wafer ( 200 ) undergoes an epitaxial layer growth operation, in which a single crystal epitaxial layer of p-type silicon is grown on the exposed substrate material in the regions ( 202 ) reserved for ICs, while polysilicon grows on the silicon nitride over the regions ( 204 ) reserved for the n-type buried layer pattern monitors. A layer of Nwell oxide is deposited on a top surface of the epitaxial layer and a top surface of the polysilicon. Referring to FIG. 2B , after the Nwell oxide deposition operation, the wafer ( 200 ) undergoes a photolithographic operation to cover the regions ( 202 ) reserved for ICs with photoresist ( 208 ) and expose the regions ( 204 ) reserved for the n-type buried layer pattern monitors to subsequent etching. While the photoresist ( 208 ) is on the wafer ( 200 ), the wafer ( 200 ) undergoes an oxide etch operation in which Nwell oxide that is exposed by the photolithographic operation is removed. Thus, the Nwell oxide is removed over the regions ( 204 ) reserved for the n-type buried layer pattern monitors, while it remains over the regions ( 202 ) reserved for ICs. After the oxide etch operation, the photoresist ( 208 ) is removed and the wafer ( 100 ) undergoes a choline etch operation, in which the polysilicon is removed. The single crystal epitaxial layer is protected from the choline etch by the Nwell oxide on its top surface. After the choline etch operation, the wafer resumes IC fabrication with a photolithographic operation to define regions for n-well ion implants. In this embodiment, the n-well pattern is aligned directly to the n-type buried layer monitors. This is advantageous because the alignment of the n-well to the n-type buried layer is optimized for each wafer using the instant embodiment. The effect of random variations from wafer to wafer in the epi pattern shift are eliminated from the n-well to n-type buried layer alignment.
The embodiment discussed in reference to FIGS. 2A and 2B may be implemented on any wafers with any integrated circuits containing n-type buried layers. FIG. 3 is a cross-section of an integrated circuit containing MOS transistors, a buried collector bipolar transistor and an n-type buried layer monitor according to an embodiment of the instant invention. Integrated circuit ( 300 ) includes a p-type substrate ( 302 ), on which is formed a p-type epitaxial layer ( 304 ), an n-well ( 306 ), a p-well ( 308 ) and regions of field oxide ( 310 ), typically silicon dioxide formed by Local Oxidation of Silicon (LOCOS) or Shallow Trench Isolation (STI), in the epitaxial layer ( 304 ) to isolate components. A p-channel MOS (PMOS) transistor ( 312 ) is formed in the n-well ( 306 ), and an n-channel MOS (NMOS) transistor ( 314 ) is formed in the p-well ( 308 ). A buried collector npn bipolar transistor ( 316 ) is formed in the epitaxial layer ( 304 ). An n-type buried layer monitor ( 318 ) is formed in the substrate ( 302 ). The PMOS transistor ( 312 ) includes a PMOS gate dielectric ( 320 ), typically silicon dioxide, silicon oxy-nitride, or hafnium oxide, a PMOS gate ( 322 ), typically polysilicon, PMOS gate sidewall spacers ( 324 ), typically silicon nitride or layers of silicon nitride and silicon dioxide, and p-type source and drain regions ( 326 ). The NMOS transistor ( 314 ) includes an NMOS gate dielectric ( 328 ), typically silicon dioxide, silicon oxy-nitride, or hafnium oxide, an NMOS gate ( 330 ), typically polysilicon, NMOS gate sidewall spacers ( 332 ), typically silicon nitride or layers of silicon nitride and silicon dioxide, and n-type source and drain regions ( 334 ). The buried collector npn bipolar transistor ( 316 ) includes an n-type buried layer ( 336 ), formed by implantation of n-type dopants, typically antimony, into the substrate ( 302 ), a deep n-well ( 338 ) connecting the n-type buried layer ( 336 ) with a top surface of the epitaxial layer ( 304 ), an n-type emitter diffused region ( 340 ) in the epitaxial layer ( 304 ), a p-type base region ( 342 ), and a p-type base contact diffused region ( 344 ). The n-type buried layer monitor ( 318 ) includes an n-type buried layer region ( 346 ), a first layer of silicon dioxide ( 348 ) outside the n-type buried layer region ( 346 ), a second layer of silicon dioxide ( 350 ) over the n-type buried layer region ( 346 ), formed during an anneal of the n-type buried layer implant, a layer of silicon nitride ( 352 ) on top surfaces of the first and second layers of silicon dioxide ( 348 , 350 ), and an n-well region ( 354 ), the pattern for which was aligned to the n-type buried layer monitor ( 318 ). An n-type buried layer ( 356 ) is formed under the PMOS transistor ( 312 ), the NMOS transistor ( 314 ) and the buried collector npn bipolar transistor ( 316 ), in the substrate ( 302 ) and diffuses partway into the epitaxial layer ( 304 ). A pre-metal dielectric (PMD) layer ( 358 ) is formed on top of the PMOS transistor ( 312 ), the NMOS transistor ( 314 ), the buried collector npn bipolar transistor ( 316 ) and the n-type buried layer monitor ( 318 ). Contacts ( 360 ), typically tungsten, are formed in the PMD layer ( 358 ) to connect the PMOS transistor ( 312 ), the NMOS transistor ( 314 ) and the buried collector npn bipolar transistor ( 316 ) to other components in the integrated circuit ( 300 ). | Integrated circuits using buried layers under epitaxial layers present a challenge in aligning patterns for surface components to the buried layers, because the epitaxial material over the buried layer diminishes the visibility of and shifts the apparent position of the buried layer. A method of measuring the lateral offset, known as the epi pattern shift, between a buried layer and a pattern for a surface component using planar processing technology and commonly used semiconductor fabrication metrology tools is disclosed. The disclosed method may be used on a pilot wafer to provide optimization data for a production line running production wafers, or may be used on production wafers directly. An integrated circuit fabricated using the instant invention is also disclosed. | 7 |
FIELD OF THE INVENTION
[0001] The present invention is related generally to scanning devices (e.g., RFID and bar-code readers) and, more particularly, to using such devices for establishing location.
BACKGROUND OF THE INVENTION
[0002] Shoppers are familiar with the machine-readable tags, such as laser-readable bar codes or Radio Frequency Identification (“RFID”) tags, attached to products in stores. These tags are read during checkout, and an accurate list of the items purchased is presented to the user, along with billing information and, sometimes, related advertising.
[0003] In addition to making customer check-out faster and more accurate, these product tags help the merchant to track his inventory. By knowing which products and how many of them leave the store, an automated system can place re-stock orders when supplies are running low or alert the merchant when a particular product is selling poorly.
[0004] In a related scenario, a merchant or wholesaler actively inventories the stock on hand by scanning the machine-readable tags in a given location (e.g., on a particular shelf in a warehouse). The read-out (from the tags) of the items actually present can be cross-referenced against a list of items presumed to be present (produced by, e.g., an inventory system that tracks products coming into and products leaving a given area). If discrepancies due to theft or due to inaccurate scanning are found, they can be corrected.
[0005] Taking inventory by scanning for machine-readable tags placed on the items has some shortcomings, however. In addition to the obvious problems of missing, duplicate, or wrongly applied tags, the nature of the scanning process itself allows for some inaccuracies. When a user initiates a scan from a hand-held scanning device, the device makes a record of all of the tags that it “sees” during the scan. But it is not always certain that the scan registers all of the tags in the location that the user intended to scan and registers none of the tags in locations that the user did not intend to scan. There are several possible reasons for this. Some scanners (e.g., RFID scanners) can identify tags at a wide angle from the direction in which the scanner is pointing when the scan is initiated. Also, the range of the scan can vary from moment to moment depending on environmental circumstances. (Radio noise can limit the effective range of radio-based scans, while dust can limit laser scans.) These and other characteristics of the scanners typically in use today mean that the user may not know exactly the scope of the scan. For example, the user may wish to inventory the products on one shelf in a warehouse. However, if the user is not very careful with positioning and pointing the scanner during the scan, the scanner may miss some of the items on the shelf or may pick up items on other, nearby, shelves.
BRIEF SUMMARY
[0006] The above considerations, and others, are addressed by the present invention, which can be understood by referring to the specification, drawings, and claims. According to aspects of the present invention, a scanning device tells its user how to best orient the scanning device to scan a target location. (For example, the target location can be a shelf or a bin in a warehouse, the location marked with RFID chips or laser-readable bar-codes.) The user approaches the target location and initiates a scan. The results of the scan are analyzed and compared to information about the target location. (This information may be downloaded to the scanning device from a central server that hosts a database of location information for the premises.) Based on the analysis, the user is told how to re-orient the scanning device, if that is necessary to achieve an acceptable re-scan of the target location.
[0007] For example, if the scan results include the target location but also include a location other than the target location, then the orientation of the scanning device was close to acceptable but not quite good enough. The central server knows the relative locations of the target location and of the scanned non-target locations. Based on this information, the user is told how to re-orient the scanning device so that the next scan reads the target location but not the non-target locations.
[0008] Some scanning technologies provide a measurement of distance from the scanning device to the scanned tag. For RFID tags, some scanners record the strength of the signal returned from every RFID tag seen during the scan, and this signal strength serves as a proxy for the distance. Other proxy distance measurements are possible for this and for other scanning technologies. Some embodiments of the present invention use these distance measurements to, for example, ignore scanned tags that are farther away than a threshold distance. Also, a scan may be deemed to be acceptable when the target location is closer by a significant amount than any non-target scanned location.
[0009] Several possibilities are contemplated for a user interface that tells the user the results of a scan. A very simple interface could present a sound or light that tells the user roughly how close he is to an acceptable orientation. (E.g., a red light means the scan did not read the target location at all; yellow means the target location was read but so too were non-target locations; and green means the scanner orientation was acceptable.) In a preferred embodiment, a screen on the scanning device presents a two-dimensional map based on the scan results and on the known relative locations of the target location and of nearby non-target locations. Locations on the map are highlighted to tell the user the results of the scan and to direct him to re-orient the scanning device if necessary.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] While the appended claims set forth the features of the present invention with particularity, the invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
[0011] FIGS. 1 a and 1 b are overviews of a representational environment in which the present invention may be practiced;
[0012] FIG. 2 is a schematic drawing of an exemplary scanning device;
[0013] FIGS. 3 a and 3 b together are a flowchart of an exemplary method for orienting a scanning device with respect to a target location; and
[0014] FIGS. 4 a , 4 b , and 4 c are drawings of an exemplary user interface on a scanning device.
DETAILED DESCRIPTION
[0015] Turning to the drawings, wherein like reference numerals refer to like elements, the invention is illustrated as being implemented in a suitable environment. The following description is based on embodiments of the invention and should not be taken as limiting the invention with regard to alternative embodiments that are not explicitly described herein.
[0016] FIG. 1 a presents a stylized layout of a typical warehouse or store 100 . A warehouse 100 often includes numerous rows 102 of shelves or bins 104 . To allow the warehouser to track the merchandise, each type of merchandise is assigned to be stored on one or more particular shelves 104 .
[0017] Inventorying the merchandise stored in the warehouse 100 is an ongoing task. As part of the inventory process, the contents of the shelves 104 are checked to make sure that all of the merchandise is properly stored and to check that the expected amount of merchandise is present in the warehouse 100 . To perform the inventory, a user is given a hand-held scanning device 106 . The scanning device 106 scans for tags affixed to the merchandise and records the tags found during the scan. Some scanning devices 106 use a laser to read bar-code tags (e.g., the UPC tags found on grocery-store items); other scanning devices 106 use a radio to read RFID tags.
[0018] The scanning device 106 may communicate with one or more wireless hubs 108 (e.g., Wi-Fi hubs) installed throughout the warehouse 100 . The scanning device 106 can communicate through the hubs 108 to a central server 110 that contains inventory information and a current map of the shelves in the warehouse 100 . In many embodiments, the scanning device 106 holds a current map of the entire warehouse 100 ; the map is updated as needed by the central server 110 . The central server 110 can send commands to the user of the scanning device 106 and can receive the results of the scans.
[0019] When the user wishes to inventory the items stored on a particular shelf 104 (called the “target shelf” or “target location”), the user orients the scanning device 106 and initiates a scan. However, the scan will be accurate only if the user correctly orients the scanning device 106 with respect to the target location 104 during a scan. If the scanning device 106 is not correctly oriented, then the scan may miss items actually present on the target shelf 104 or may register items on neighboring shelves.
[0020] Aspects of the present invention help the user to correctly orient the scanning device 106 so that he can get an accurate scan of the target location 104 . FIG. 1 b shows an array of shelves 104 . To facilitate proper orienting of the scanning device 106 , the shelves are tagged with RFID or laser-scan tags 114 . ( FIG. 1 b shows one embodiment of the tagged shelves 104 , but the positioning and number of tags 114 can be varied to optimize the detection of the tags 114 , the variations among embodiments based on particularities of the scanning environment.) As explained in greater detail below, a scan registers these tags 114 (as well as registering tags on merchandise). The scanning of these tags 114 is used to determine, and to correct if necessary, the orientation of the scanning device 106 with respect to the target location 104 . Note that the labels 112 on the shelves 104 (e.g., “C 1 R 1 ” for “column 1 , row 1 ”) are for purposes of the present discussion and need not actually appear on the shelves 104 in the warehouse 100 .
[0021] FIG. 2 shows some relevant elements of a typical scanning device 106 . A transceiver 200 allows communication with the hubs 108 for communication with the central server 110 and for roughly determining the position of the scanning device 106 , as discussed below. A second transceiver 204 performs the scan (laser or radio). A processor 202 runs the two transceivers 200 , 204 and controls a user interface 206 . The user interface 206 receives commands from the user (e.g., a command to initiate a scan) and presents results of the scan. Embodiments of the user interface 206 are discussed below.
[0022] The flowchart of FIGS. 3 a and 3 b presents one embodiment of the methods of the present invention. The user of the scanning device 106 is told to scan a particular shelf 104 . (The command could come from the central server 110 and be delivered to the scanning device 106 via a hub 108 .) In step 300 , the user approaches the target location 104 . For example, the user may have in his head the general layout of the warehouse 100 and may know how to get reasonably close to the target location 104 . Also, for many warehouses 100 a map has been made that correlates received signal strengths from the wireless hubs 108 with a physical location in the warehouse 100 . Using this map, the scanning device 106 can analyze the signals it is receiving from the hubs 108 and know its rough location in the warehouse 100 . The scanning device 106 can then tell the user how to come close to the target location 104 . (Generally speaking, GPS does not work very well in a typical warehouse 100 .) In some embodiments, the central server 110 knows approximately where the user is currently standing (e.g., near the previous target location) and can send instructions to the user to get him close to the next target location 104 . At the end of step 300 , the user is within a couple of meters of the target location 104 .
[0023] For purposes of the present discussion, assume that the user is now facing the array of shelves shown in FIG. 1 b , and assume that the target location is C 2 R 1 . FIGS. 4 a , 4 b , and 4 c illustrate one possible user interface 206 of the scanning device 106 . On a screen of the scanning device 106 is shown a two-dimensional display of the local environment. In FIG. 4 a , the target location C 2 R 1 is highlighted for the user. (In actual embodiments, the highlighting can be a bright color, e.g., blue, rather than the diagonal stripes of FIG. 4 a .) A simpler alternative user interface 206 is described below.
[0024] In step 302 , the user orients the scanning device 106 as best he can with respect to the target location 104 and, in step 304 , initiates a scan.
[0025] The scanning device 106 receives the results of the scan in step 306 . At a minimum, the results of the scan include a list of tags read during the scan. In some embodiments, an actual distance or a “proxy” distance is associated with each tag on that list. This measures the approximate distance from the scanning device 106 to the tag at the time of the scan. A measurement is a “proxy” distance when the scanning technology does not measure this distance directly. Some RFID technologies record the strength of the signal returned from each tag read during the scan, and this signal strength can be used as a proxy distance measurement (of course, a weaker signal means a greater proxy distance). Other RFID technologies run a sequence of scans at different power levels to measure proxy distances. Tags read with a lower power are considered to be nearer than tags that can only be read with a higher power. Other proxy distance measurements are possible and may be used. When scanning devices 106 that determine actual distances become more widespread, their distance measurements can replace these proxy distances. While distance measurements, whether actual or proxy, are very useful (see step 310 below), embodiments of the present invention are also useful even with scanning devices 106 that provide no distance measurements of any kind.
[0026] In step 308 , the results of the scan are analyzed, either locally by the processor 202 of the scanning device 106 or remotely by the central server 110 . Because any merchandise tags registered during the scan are irrelevant for purposes of properly orienting the scanning device 106 , these tags are ignored for now, and the following discussion only concerns those tags 114 affixed to specific shelves 104 .
[0027] Properly speaking, step 310 is an optional part of the analyzing step 308 . If distance measurements are available (either actual or proxy), then those tags 114 read during the scan that are too far away (e.g., more than a first threshold distance away) can be ignored during the analysis of step 308 .
[0028] The set of location tags 114 read during the scan (excluding the tags filtered-out in step 310 , if any) is analyzed in step 308 to determine whether or not the orientation of the scanning device 106 during the scan was appropriate. In general, there are three possible results of this analysis (that is, three possible “determined presence conditions” of the target location 104 ): (1) The target location 104 was not definitively found. (“Definitive” here means that the signal strength of the target location 104 is greater than the first threshold mentioned above.) (2) The target location 104 is found definitively but not uniquely. (3) The target location 104 is found both definitively and uniquely. Result (3) is the desired one.
[0029] Different analysis algorithms can be used to characterize the results of the scan into one of the three possible presence conditions mentioned above. As a simple example, the target location 104 is found definitively and uniquely if its location tag 114 is the one and only location tag remaining on the scan list. If proxy distances are available, then the target location 104 can also be found definitively and uniquely if (a) its location tag 114 is on the list and (b) the proxy distance for the target location's tag 114 is less, by at least a threshold amount, than the distance of any other location tag on the list.
[0030] Again if distance measurements are available, the target location 104 is found definitively but not uniquely if (a) its location tag 114 is on the list and (b) the proxy distance for the target location's tag 114 is not less, by at least the threshold amount, than the distance of at least one other location tag on the list.
[0031] In step 312 , the determined presence condition of the target location 104 is presented to the user via the user interface 206 of the scanning device 106 . A very simple user interface 206 could simply indicate which of the three possibilities applies. For example, a “stoplight” could be shown: Red means not definitively found, Yellow means found definitively but not uniquely, and Green means found definitively and uniquely. Alternatively, a specific sound could be played to indicate the determined presence condition.
[0032] A more useful two-dimensional interface 206 is illustrated in FIGS. 4 a , 4 b , and 4 c . In this interface, the boxes representing the nearby shelves are colored to indicate the determined presence condition. In one embodiment, the following rules are used for the coloring:
[0033] Color gray any shelf whose location tag 114 either was not read during the scan or that was excluded from consideration in step 310 . Also, color all shelves gray if the target location 104 was not read during the scan.
[0034] If the target location 104 was read during the scan, then:
Color yellow any shelf whose location tag 114 generated a fairly strong signal (e.g., above a second threshold). If the target location 104 returned a very strong signal (e.g., above a third threshold), and if that signal is significantly stronger than the signals returned by neighboring locations, then color green any shelf whose location tag 114 generated a very strong signal. If more than one green shelf is found, then re-assign the green shelves to yellow.
Using these rules, the orientation of the scanning device 106 was close but not exact (i.e., the target location 104 was found definitively but not uniquely) if the user interface 106 shows a number of yellow boxes. FIG. 4 b shows this possibility (pretend that the boxes representing shelves C 2 R 1 and C 2 R 2 are colored yellow). FIG. 4 c shows the case where the target location 104 was found definitively and uniquely (box C 2 R 1 is colored green).
[0038] The specific user interface 206 of FIGS. 4 a , 4 b , and 4 c illustrates a useful function not available with the simpler “stoplight” interface. Consider FIG. 4 b . The user, on seeing this on the screen of the scanning device 106 , knows not only that the most recent scan was close but not quite good enough, but he also sees what was wrong with the scan. Clearly, the scanning device 106 that produced the results of FIG. 4 b was pointed too low. Thus, this user interface 206 can tell the user (in step 314 ) how to correct the orientation of the scanning device 106 to get a better scan.
[0039] In step 316 , the user repeats the scan, if necessary, until a good result (target location 104 found definitively and uniquely) is achieved. When a good result is achieved, the user knows that the list of merchandise tags found in the scan (the list filtered, as appropriate, for actual or proxy distance) truly represents the entire contents of the target location 104 and does not include merchandise tags from neighboring shelves. Of course, the methods of the present invention are not limited to the case of taking inventory but are useful whenever a target location needs to be scanned for whatever reason.
[0040] In view of the many possible embodiments to which the principles of the present invention may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the invention. For example, other user interfaces employ other formats to present the scan results. Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof. | Disclosed is a method for a scanning device to tell its user how to best orient the scanning device to scan a target location. The user approaches the target location and initiates a scan. The results of the scan are analyzed and compared to information about the target location. Based on the analysis, the user is told how to re-orient the scanning device, if that is necessary to achieve an acceptable re-scan of the target location. In a preferred embodiment, a screen on the scanning device presents a two-dimensional map based on the scan results and on the known relative locations of the target location and of nearby non-target locations. Locations on the map are highlighted to tell the user the results of the scan and to direct him to re-orient the scanning device if necessary. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a security chip and a method of manufacturing a security chip.
BACKGROUND OF THE INVENTION
[0002] Security chips (sometimes referred to as security integrated circuits) are used in many products where assets need to be protected. These assets include information, personal details, value (typically monetary), data transmissions and access rights. The assets are protected by various defensive means, each designed to foil attacks on the chip and its assets.
[0003] Recently, fault induction attacks on the operation of chips, including differential fault analysis (DFA), have been gaining prominence. A fault induction attack is an attack where the chip is forced to make an error in an operation. Some errors that a chip can be forced to make can be exploited to reveal secret information and the attack is then successful.
[0004] A typical fault induction attack uses a flash or pulse of light (e.g. from a pulsed laser) aimed at a small section of the circuit with the aim of disrupting some function, calculation or other operation of the chip. The laser pulse is aimed at a precise location on the chip and within a specific time period during the chip operation. It is speculated that the light pulse causes the CMOS gates in the chip circuit to have an indeterminate output for any determined input. This indeterminate output might, for example, make a branching instruction take the wrong branch, leading to the execution of the wrong software. This incorrect execution might then be exploited to reveal secret information (sensitive data) or to bypass authorisation checks, for example.
[0005] One of the main defences against attacks such as those described above is the use of a passive shield.
[0006] Passive shields are large flat areas of metal over all or part of the chip circuit and are designed to prevent viewing and probing and make attacks more time consuming. Passive shields are often made from an upper layer of metal interconnects in a multi-layer circuit.
SUMMARY OF THE INVENTION
[0007] Defences against fault induction attacks may be implemented in application or operating system software but two problems exist. Firstly, each potential attack must have a unique solution put in place. For example, an attack on a particular point in a cryptographic algorithm may require a completely different solution to an attack on a different algorithm or even an attack on a different point in the same algorithm. Secondly, software defences can be costly in terms of chip performance.
[0008] Passive shields could be effective at preventing fault induction attacks by preventing passage of the light/pulse to the chip circuitry underneath the shield. By covering the entire chip, the solution would not depend on the specifics of the attack and there would be no effect on chip performance.
[0009] As shown in FIG. 1 , the ideal passive shield 101 is a sheet of opaque material (e.g. a metal such as aluminium or copper) covering the entire chip. This would prevent any penetration of a light pulse 102 used to perpetrate fault induction attacks. However, aluminium and silicon dioxide, the two materials most commonly used in chip construction, have very different coefficients of thermal expansion. Changes in temperature lead to a significantly greater expansion of the passive shield 101 in comparison to the silicon dioxide layers (not shown) that encapsulate the aluminium metal layers 103 / 104 / 105 and the layers can therefore split apart, or ‘delaminate’. This leads to chip failure, either immediately or after a short time as the aluminium metal is exposed to the corrosive effects of the atmosphere.
[0010] Delamination may be overcome by making a passive shield composed of limited areas of shield, each of which is sufficiently small such that the stress does not lead to delamination (see FIG. 2 ). For example, a passive shield may be made of many parallel long narrow strips 201 / 202 of shield. In this way, 95% of the chip surface (or possibly greater) can be shielded. However, passive shields constructed in this way have paths at the edges of the strips 201 / 202 through which light 203 can penetrate. Light penetrating the gaps between the strips of shield will undergo diffraction at the edges of the shield. As such, the area of chip circuit accessible to the light is therefore much greater than the area directly under the gaps. Light will bend at the edge of the metal layers and subsequent reflections under the shield ensure that the light penetrates many tens of microns under the passive shielded area. Therefore such passive shields are known not to be effective against fault induction attacks in many cases.
[0011] Therefore, existing passive shields may either be mechanically robust to prevent delamination, or effective in stopping light based fault attacks, but not both.
[0012] There is provided in accordance with embodiments of the present invention a security chip including: a substrate; an integrated circuit disposed on the substrate, the integrated circuit including circuit elements, circuit interconnect layers connecting the circuit elements together, and interlayer contacts supporting the circuit interconnect layers; a shield to at least partially shield the integrated circuit; and at least one lightwell in the shield and the integrated circuit, wherein each lightwell has a closed shape formed from parts of the circuit interconnect layers and interlayer contacts, wherein no exploitable voltage can be measured on the parts of the circuit interconnect layers and interlayer contacts, and wherein each lightwell forms a path for light to penetrate to the substrate preventing the light from reaching the circuit elements.
[0013] In some embodiments, the parts of the circuit interconnect layers and interlayer contacts are connected to a constant voltage circuit element of the integrated circuit.
[0014] In further embodiments, the parts of the circuit interconnect layers and interlayer contacts are connected to a ground potential of the integrated circuit.
[0015] In other embodiments, the closed shape is a ring.
[0016] In some embodiments, the ring is a square ring.
[0017] In further embodiments, spaces between the interlayer contacts are sufficiently small to block all visible and infra-red light.
[0018] In some embodiments, the interlayer contacts are spaced less than or equal to 0.18 microns apart.
[0019] In other embodiments, the lightwells have a lightwell width and are separated by a distance greater than or equal to ten times the lightwell width.
[0020] In further embodiments, the security chip further includes one or more light sensors at the base of one or more of the lightwells.
[0021] In some embodiments, the exploitable voltage comprises a varying voltage wherein the variation in voltage correlates with a sensitive data value.
[0022] There is also provided in accordance with a further embodiment of the present invention a method of manufacturing a security chip, the security chip including: a substrate; an integrated circuit disposed on the substrate, the integrated circuit including circuit elements, circuit interconnect layers connecting the circuit elements together, and interlayer contacts supporting the circuit interconnect layers; and a shield to at least partially shield the integrated circuit, the method including forming at least one lightwell in the shield and the integrated circuit, wherein each lightwell has a closed shape and is formed from parts of the circuit interconnect layers and interlayer contacts, wherein no exploitable voltage can be measured on the parts of the circuit interconnect layers and interlayer contacts, and wherein each lightwell forms a path for light to penetrate to the substrate preventing the light from reaching the circuit elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:
[0024] FIG. 1 is a simplified pictorial illustration of a cross sectional view through part of a security chip having a passive shield that covers the entire security chip;
[0025] FIG. 2 is a simplified pictorial illustration of a cross sectional view through part of a security chip having a passive shield that covers part of the security chip;
[0026] FIG. 3 is a simplified pictorial illustration of a cross sectional view through part of a security chip constructed and operative in accordance with an embodiment of the present invention;
[0027] FIG. 4 is a simplified pictorial illustration of a cross sectional view through part of a security chip constructed and operative in accordance with an embodiment of the present invention; and
[0028] FIG. 5 is a simplified pictorial illustration of a three dimensional view through part of a security chip constructed and operative in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0029] The present invention, in embodiments thereof, comprises a security chip that is effective against attack by light or other disrupting media (such as is used in a fault induction attack). The security chip includes a passive shield that is mechanically robust and stable while still preventing access to the chip circuit below the shield. In particular, it addresses the above described problem that gaps in existing passive shield designs do not prevent light penetration at all points on the chip surface. As such, existing passive shield designs are not invulnerable to attack.
[0030] Referring now to FIG. 3 (which is not drawn to scale), a cross-section of a security chip is shown. Security chip 301 typically comprises a substrate 303 (typically made of silicon) which preferably includes an integrated circuit 305 disposed thereon. The terminology ‘disposed thereon’ is used for the sake of simplicity. However, it will be appreciated by those skilled in the art that integrated circuits are typically formed partially within the chip material, for example, but not limited to, by doping the chip material, and partially on top of the chip material, typically in metal and insulating layers. However, the term ‘disposed thereon’ as used in the specification and claims is defined to include disposed thereon and/or therein the substrate.
[0031] Circuit 305 typically comprises transistors, diodes, interconnections and all well-known circuit elements. Circuit 305 typically covers the majority of substrate 303 .
[0032] A passive shield 307 , constructed from an opaque material (e.g. a metal such as aluminium or copper), is provided over circuit 305 . The passive shield prevents light from passing through to the circuit below the shield.
[0033] Interspersed throughout circuit 305 are a series of lightwells in the passive shield and the underlying circuit elements. The lightwells are a path in which no passive shield is present and through which light can penetrate to the substrate below. The lightwells therefore act as gaps in the passive shield which maintains maximum strength against delamination for the smallest circuit area used. Additionally, the walls of the lightwell are as impervious to light as possible. This is achieved using parts of the metal layers and interlayer contacts (also called vias or interconnect vias), both of which are typically present in circuits and easily available for use in the design of the new passive shield. The parts of the metal layers that form the walls of the lightwells are areas of the metal layers that are completely separate electrically from the rest of the metal layers. The parts of the metal layers that form the walls of the lightwells are typically connected to a ground potential or to any signal that cannot be exploited in an attack on the chip. An example of a signal that cannot be exploited in an attack on the chip is a varying voltage where the variation in voltage does not correlate with any sensitive data value. Put another way, no exploitable voltage potential can be measured on the parts of the metal layers and interlayer contacts forming the lightwell walls and therefore there would be no advantage to an attacker in probing these parts of the metal layers or interlayer contacts or analysing/measuring the voltage on them. Moreover, no circuit elements are contained within the lightwell (other than an optional light sensor, which will be described in more detail below) and therefore the lightwells prevent light getting to the chip circuit elements and thus prevent a security breach caused by light passing through the passive shield.
[0034] An example of one of the lightwells interspersed throughout circuit 305 is shown in FIG. 4 (cross section) and also in FIG. 5 (three dimensional). The walls of the lightwell 401 are made from rings 403 of circuit interconnect metal (shown in FIG. 5 as square rings, but it will be appreciated that any other closed shape would be suitable). Typically, the circuit interconnect material (as well as the material used for passive shield 307 ) is metallic (e.g. aluminium or copper). Four layers of metal interconnect are shown in FIGS. 4 and 5 as forming the lightwell 401 . The number of layers of metal interconnect can be any number from one up to the total number of metal interconnect layers but is typically one less than the total number of metal interconnect layers used in the circuit.
[0035] The rings 403 are supported by closely spaced interlayer contacts 405 (also called vias or interconnect vias) used to connect individual layers of interconnects. There are typically small gaps 407 between vias. Typically, the interlayer contacts are tungsten plugs but other schemes, such as dual damascene interconnects used in copper based circuits are also possible.
[0036] The space between the metal interconnects is filed with interlayer dielectric (ILD), although this is not shown in FIG. 4 or 5 for reasons of clarity. ILD is a glass-like material, typically silicon dioxide but other materials may be used. The purpose of the ILD is to support the metal interconnects and hold the entire chip structure together. The ILD is typically transparent and is not conductive. The ILD fills the entire circuit from substrate 303 to above the top metal layer.
[0037] Lightwells similar to lightwell 401 are deployed across the entire passive shield area in sufficient number to alleviate mechanical stress in the passive shield layer. The number of lightwells depends on several factors related to the design and manufacturing process of the chips. Typically, the lightwells form a grid over the security chip in areas where lightwell placement is possible. Lightwells are preferably omitted in areas where placement is difficult, such as over memory blocks.
[0038] The separation of the lightwells is typically equal to or greater than ten times the lightwell width. This ensures that the chip is mechanically stable (i.e. the circuit can be held together without the danger of delamination) and that the maximum area of the chip lost to lightwells (and therefore unavailable for parts of the chip circuit) is 1% of the total area of the chip. Security chip circuits with areas of passive shield with a minimum dimension of 100 microns have been observed by the inventors. According to the above description of the separation of lightwells, this implies a minimum spacing of 10 lightwells per linear millimetre or 100 lightwells per square millimetre. Lightwells as small as 10 square microns are known by the inventors to be possible, which implies a ‘fill-factor’ of 1% as mentioned previously.
[0039] Unlike previous passive shield designs where light passing the edges of the passive shield can reach the chip circuit underneath the passive shield and thus attack the chip circuit, according to embodiments of the present invention light is confined to the lightwell. Each metal layer 403 of the circuit below passive shield 307 is used to form part of the barrier preventing light penetration to the rest of the circuit. In addition, layer interconnect vias 405 , typically columns of tungsten (called tungsten plugs) when using an Aluminium chip manufacturing scheme, further limit or prevent light penetrating from the lightwell to the circuit.
[0040] The gaps 407 between the interconnect vias 405 and the gaps between metal layers are typically sufficiently small such that light cannot penetrate through these gaps. Light of a sufficiently small wavelength will penetrate the gaps but the gaps may be made sufficiently small such that light of such wavelengths would be absorbed before it can attack the circuit. For example, the gap between the tungsten plugs used with an Aluminium chip manufacturing scheme is typically 0.18 microns. This is sufficiently small to block all visible and infra-red (IR) light but may not totally block near ultra violet (NUV) light having a wavelength of approximately 250 nm-400 nm. Therefore some light might penetrate between tungsten plugs spaced at 0.18 microns if a NUV laser (typically emitting light with a wavelength of 355 nm) is used. If the gaps between the tungsten plus are reduced to 0.13 microns (as is expected in the future by the inventors as technology shrinks), light penetration becomes unlikely as the short wavelength of light required to penetrate such a gap (i.e. a 255 nm laser) will not penetrate the ILD. Even smaller gaps are also possible (e.g. 0.09 microns, 0.065 microns, 0.045 microns, 0.032 microns and 0.022 microns).
[0041] The present invention, in embodiments thereof, can be included in any silicon chip that is manufactured according to methods of making such chips that are well known to someone skilled in the art. Examples of methods of chip manufacture can be found in “ Microchip Fabrication ”, Peter Van Zant, ISBN 0071432418, 5 th Edition, 2004. The inventors of the present invention are aware of two principal schemes of making silicon chips (more than 99% of chips currently made use one or other of the two schemes) and both schemes may incorporate the present invention, in embodiments described herein. The two schemes are differentiated by the materials used to make the interconnecting conductors linking the circuit elements. In one scheme, metal interconnects are disposed in aluminium metal in each layer of interconnect. Connections between each interconnect layer are made with short tungsten pillars (plugs). In the second scheme, typically used in circuits with smaller device geometries, the metal interconnect layers and the connections between layers are made in copper metal. In both schemes, the lightwells are made in these materials and are independent of any technology used to make the chip circuit elements on the silicon surface.
[0042] It will be apparent from the foregoing description that many modifications or variations may be made to the above described embodiments without departing from the invention. Such modifications and variations include:
[0043] In alternative embodiments, one or more light sensors 409 can be placed at the bottom of each lightwell. If an attack is attempted on a chip according to embodiments of the present invention, the only possible entry point for light is through one of the lightwells. A light sensor 409 placed at the bottom of the lightwell will detect an attack and can be used to enable the chip to detect attack attempts so that it can take relevant precautions (e.g. disable application software). Light arriving at a light sensor 409 placed at the base of a lightwell will necessarily be of much greater intensity than any light penetrating through the walls of the lightwell, and is therefore easily detected.
[0044] In alternative embodiments, the security chip may also be protected by an active shield to protect the chip from other classes of attack. Active shields are networks of circuit tracks covering a circuit which, if cut or short-circuited to each other, actively halt chip operation. Therefore, a breach in the active shield results in the disabling of some or all of the chip functions. Preferably, the top metal circuit layer is used as an active shield. The active shield is also preferably placed on top of the chip to protect both the passive shield and the rest of the chip below the passive shield. The active shield also has the effect of scattering any light directed at it. If a light sensor similar to light sensor 409 is present at the base of the lightwell, the scattering of the light might cause the light to hit the light sensor, which will trigger defence mechanisms in the circuit as described previously.
[0045] Delamination of current security chips through stress is a result of the large difference in coefficients of thermal expansion between aluminium (22 ppm/K) or copper (16.5 ppm/K) and silicon dioxide (0.6 ppm/K). If a material other than aluminium or copper is used to manufacture the passive shield (i.e. a material having a coefficient of thermal expansion closer to that of silicon dioxide), it is also possible to make a complete, contiguous and mechanically sound passive shield to cover the entire chip surface. For example, the use of invar, a steel based alloy specifically designed to be of low thermal expansion coefficient, has been found to substantially obviate the delamination problem. The use of invar in the manufacture of security chips was, prior to this invention, unknown.
[0046] It is appreciated that various features of the invention which are, for clarity, described in the contexts of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable subcombination.
[0047] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the invention is defined by the appended claims and equivalents thereof. | A security chip is disclosed. The security chip includes: a substrate; an integrated circuit disposed on the substrate, the integrated circuit including circuit elements, circuit interconnect layers connecting the circuit elements together, and interlayer contacts supporting the circuit interconnect layers; a shield to at least partially shield the integrated circuit; and at least one lightwell in the shield and the integrated circuit, wherein each lightwell has a closed shape formed from parts of the circuit interconnect layers and interlayer contacts, wherein no exploitable voltage can be measured on the parts of the circuit interconnect layers and interlayer contacts, and wherein each lightwell forms a path for light to penetrate to the substrate preventing the light from reaching the circuit elements. Related apparatus and methods are also disclosed. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is related to and claims all available benefit to U.S. Provisional Application Ser. No. 60/679,880 filed May 11, 2005.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to multi-channel sound systems and to apparatus for producing a sound field that can be substantially independent from the acoustical effects of the playback room or environment. Such systems are well suited for producing repeatable and consistent sound fields for auralizing the characteristics of any selected venue at a second venue. As used herein, the term “auralizing” is intended to mean the process or method of rendering audible, by physical or mathematical modeling, the sound field of a source in a space, in such a way as to simulate the binaural listening experience at a given position in a modeled or another space.
[0004] 2. Related Art
[0005] A widely accepted professional standard for speaker placement for multi-channel sound reproduction is the ITU-R BS.775-1. The standard identifies a few well-known points including the positioning of the reference listening point at the center of an imaginary circle having a radius between 2 m and 4 m (min. and max. radius defined in the ITU-R BS.1116-1 recommendation). According to the standard, a center speaker should be placed at a zero-angle reference position directly ahead of the listening point. There should be 60° between the front left and right speakers, with the center speaker in the middle. Both rear speakers should be placed within 100° to 120° from the zero-angle reference position, also known as the center line. If more than two rear speakers are used, they should be symmetrically placed between 60° and 150° from the center line. The acoustical axis of the front speakers—as defined by the speakers' manufacturer—should be approximately at the listener's ear height. The height of the rear speakers may be less critical and an inclination of up to 15° can generally be accepted. The standard also recommends that each of the five speakers be positioned more than 1.1 m from any wall located behind the speaker. Any variations in deployment of the speakers may affect the aural perception of the sound produced by the set of speakers.
[0006] Commercial surround sound systems are often installed at wide variance to this standard. Often the speakers selected for the various positions vary widely in sound reproduction characteristics. Small, even insignificant, variations in the sounds produced by such surround sound systems may be undetectable by the ordinary listener, but are very evident to the trained ear of a sound engineer. Special listening rooms have been constructed to permit the evaluation of various audio components or program materials by sound engineers. It has been observed, however, that various listening rooms have differing characteristics that affect the resulting sound field and different evaluations of sound components can result merely from the movement of the same component from listening room to listening room. It has also been observed that listening rooms of the same general design can have differing characteristics, due to construction and material variations, that affect the resulting sound field. This lack of listening room uniformity presents problems for audio system engineers in component design and standards compliance. The acoustic differences in the various listening rooms may be attributable to the differences in wall placement and covering as well as many other factors.
[0007] In many regards, it would be desirable to be able to make professional listening rooms acoustically identical so that component designs could be more objectively assessed. This is particularly true of circumstances where evaluations of components or program materials may take place in different cities or countries. Such acoustically identical listening rooms could then be used as a consistent reference system to create “anchors” for various levels of audio system quality. It would also be desirable to be able to modify the acoustic character of such listening rooms in a purposeful way using digital signal processing to achieve, if desired, reproduction of the spatial characteristics of known venues such as various cathedrals, night clubs, stadiums, concert halls, automobiles, home theatres, studios, etc. It would also be desirable to be able to consistently reproduce multiple directional sound cues around listeners located in different rooms, automobiles, buildings, or even countries, so that a common acoustic experience could be assured at different locations, either simultaneously or spaced in time. It would also be desirable to provide systems capable of consistently reproducing multiple directional sound that faithfully reproduced the “sound room” quality in rather restricted environments such as home theaters, game rooms, home offices, and the like.
SUMMARY
[0008] Accordingly, a compact spatial array sound reproduction system employs a plurality of identical speakers coupled to a mechanical assembly that situates the speakers at known, fixed distance from each other as well as a central listening point. The speakers can be coupled to a standard surround sound reproduction system. The speakers can also be coupled to a multi-channel signal processing amplifier that can be controlled in various known ways to reproduce a desired acoustic experience. The mechanical assembly can be permanently installed in a single location. The assembly can also be designed to be easily assembled and disassembled to permit transport of the system from location to location resulting in the reproduction of the identical acoustic experiences at different locations spaced in time. The mechanical assembly can be designed to have minimal interference or reflective character so that its acoustic impact on the sound field developed by the speakers may be insignificant.
[0009] The assembly can employ a plurality of spacing elements coupled together at prescribed locations. The assembly can be provided with a plurality of hinges that allow the spacing elements to be folded one on another into a compact package for easy transport from location to location. Other coupling means can be employed such as plug, bayonet, or even screw connections between the spacing elements. The spacing elements can be supported by vertical standards that couple to the spacing elements. The spacing elements and the vertical standards can be adjustable in length. The vertical standards can be used to support the spacing elements with respect to any underlying surface such as a floor or desk top. The vertical standards can also be used to suspend the spacing elements from a ceiling or other overhead structure. The spacing elements can include all the wiring necessary to couple the speakers to the amplifier outputs as well as jacks to facilitate the connection between the wiring and the speakers. The jacks can be located so as to position speakers at the standard ITU angles around a central listening position, but can also be included at other locations. The radial separation of the speakers from the central listening position can be smaller than the ITU standard to facilitate the use of near-field monitoring techniques.
[0010] Each speaker can be designed to couple directly to the spacing elements with mating connectors, including banana jacks, in the vicinity of one of the hinges. The mechanical coupling between the speaker and the spacing elements can be sufficient to immobilize the hinge. Additional hinge immobilization elements can be employed. The speakers preferably have an enclosure volume of no less than about 0.5 liter. The speakers can also have a sound reproduction range of at least 80 Hz to 20 kHz, and a power handling capability of at least 15 Watts. A suitable speaker that can be used in the present system is an Odyssey Warrior manufactured by Harman International. Other speakers or speaker assemblies, of comparable performance characteristics can also be employed. Low frequency responsive speakers can also be added to the system, if desired. The speakers can be coupled to the outputs of a multi-channel signal processing amplifier such as a Harman Kardon model AVR 630. Other DSP amplifiers can be used that have at least comparable sound reproduction and control characteristics. The speaker assembles can also be beneficially used with other amplifier systems to achieve satisfactory, if not optimal, sound reproduction capabilities to enhance the listening experience of the ordinary listener, particularly in home theatre or game station situations. In another embodiment, the spacing elements can also be used to house and enclose the speaker drivers, The spacing elements can be constructed from plastic tubing that fits together to form an array of various dimensions with speaker locations as needed to suit various specific requirements including non-standard azimuths and elevations.
[0011] Using such a portable spatial array sound reproduction system, a sound engineer can minimize acoustic reflections and resonances to produce a sound field that may be substantially independent from the acoustical effects of the playback room or other environment in which the system may be installed. Therefore, the acoustical characteristics recorded into a signal source can better be demonstrated without the added effects caused by the playback environment and boundaries. Also, the system can be used as a means to consistently reproduce an acoustic sound field for purposes of listener training and testing, subjective referencing for evaluations, mixing/mastering, and other activities. Such a portable system can be used by a sound engineer to mimic the acoustic characteristics of any venue in which it may be installed. Preferably, the direct acoustic energy should be more than 10 dB higher in level than the early reflected acoustic energy that occurs within 10 ms and more than 20 dB higher in level than the reflected acoustic energy that occurs after 15 ms. This can be determined by measuring the impulse response of each speaker with a microphone located at the listener's position.
[0012] Other systems, methods, features and advantages will be, or become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of, and be protected by, the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present system can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the system. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.
[0014] FIG. 1 is a block diagram of a multi-channel surround sound amplifier that can be used in a spatial array sound reproduction system.
[0015] FIG. 2 is a schematic plan view of a representative spatial array sound reproduction system.
[0016] FIG. 3 is a schematic plan view of another spatial array sound reproduction system.
[0017] FIG. 4 is a plan view of a single tubular element that can be used to construct the spatial arrays shown in FIGS. 2 and 3 .
[0018] FIG. 5 is a plan view of a single tubular end element that can be used to construct the spatial array shown in FIGS. 2 and 3 .
[0019] FIG. 6 is an elevation view of the set of tubular elements such as are shown in FIGS. 4 and 5 that can be used to construct the spatial arrays shown in FIGS. 2 and 3 , the tubular elements being folded together for ease of transport between venues.
[0020] FIG. 7 is an elevation view of a portion of the set of tubular elements shown in FIG. 6 , the elements having been unfolded to form a planar array for use in the spatial array sound reproduction systems of FIG. 2 or 3 .
[0021] FIG. 8 is an elevation view of a portion of a set of tubular elements immediately prior to connection to a supporting standard.
[0022] FIG. 9 is a schematic view of the junction between the tubular element and standard of FIG. 8 .
[0023] FIG. 10 is an exploded perspective view of an alternate junction between a tubular element of the array and another type of vertical standard.
[0024] FIG. 11 is a detail plan view of a hinged junction between two of the tubular elements forming a planar array.
[0025] FIG. 12 is a schematic illustration of a connection between the tubular elements and a speaker.
[0026] FIG. 13 is a perspective view of a representative spatial array sound reproduction system installed on a desk.
[0027] FIG. 14 is a perspective view of a representative spatial array sound reproduction system installed as a suspended array.
[0028] FIG. 15 is a perspective view of another representative spatial array sound reproduction system installed on a desk suitable for use in connection with a gaming computer.
DETAILED DESCRIPTION
[0029] FIG. 1 is a block diagram of a multi-channel surround sound source 100 that can include an analog input stage 102 . The analog input stage 102 can include any number of input channels, but typically includes at least two stereo channels (left and right), suitable for accepting an analog signal from a radio or television tuner, a CD, MP3, tape player, or other similar device. The analog input stage 102 can also include an analog to digital converter 104 for converting the signals in each input channel to a digital format to permit digital signal processing methods to be used on the input signals. The sound source 100 can also include a digital input receiver 106 that can be designed to accept digital signals (via SPDIF, AES/EBU) directly from various sources 105 such as a CD or DVD player, cable, satellite, game box, computer, or other similar device with discrete digital signals. Signals output from either or both of the A/D converter 104 and receiver 106 can be fed into a digital signal processing decoder 108 that can include any number of basic conventional commercial decoders 110 such as Dolby® Digital (AC-3), DTS (389r2) as well as others. The output of the signal processing decoder 108 can be directed to a digital signal processing control section 112 . The control section 112 can include specific preset processing functional aids 114 to provide for dynamic equalization, delays, mixing, and feedbacks leading to a multilevel surround output that can be fed to a first multi-channel digital to analog converter 116 . The control section 112 can also connected to a further control section 118 that includes user interface controls 120 and set buss commands 122 for developing a second multilevel surround output that can be fed to a second multi-channel digital to analog converter 124 . A multi-channel power amplifier 126 can amplify the analog outputs of the converters 116 and 124 to achieve a suitable signal for driving a set of speakers 18 .
[0030] FIGS. 2 and 3 show schematic plan views of spatial array sound reproduction systems 10 . Each system 10 includes at least one sound source, which can be a pre-amplified signal that may be output from a radio, television, record turn table, CD player, tape player, I-pod, computer, or other similar device, but preferably the sound source 100 described previously. The sound source generally has suitable controls, such as the user interface controls 120 , to permit a sound engineer or other individual situated at position X shown in FIGS. 2 and 3 to control each output of the power amplifier 126 . Each of the outputs can be coupled to one of the speakers 18 . For example, a center channel output can be connected to speaker 18 CF. Front side outputs can be connected to speakers 18 LF and 18 RF, respectively. Side outputs can be connected to speakers 18 LS and 18 RS, respectively. Base outputs can be connected to one or more subwoofer speakers, such as speakers 28 L and 28 R. The spatial array of the system 10 situates the speakers 18 at fixed distances from each other. In both FIGS. 2 and 3 , speaker 18 CF is situated directly in front of the listener situated at position X, and the line between speaker 18 CF and position X can be considered as the zero-angle reference position, and also defines the center line 20 . When used in connection with a visual output device such as a computer screen, as shown in FIG. 13 , or a television screen as shown in FIG. 14 , the speaker 18 CF can be positioned in line with, or directly above, the center of the visual output device. Speakers 18 LF and 18 RF are shown in both FIGS. 2 and 3 to be situated at 30° left and 30° right, respectively, of the center line 20 , which may be angularly in accordance with the speaker placement standards for multi-channel sound reproduction specified in the ITU-R BS.775-1. The left and right angular displacement of the speaker 18 LF and 18 RF can vary between about 25° and 35°, but the angular displacement is desirably consistent from system to system where exact audio reproduction is desired.
[0031] In FIG. 2 , the speakers 18 LS and 18 RS are positioned at 111° left and 111° right, respectively, of the center line 20 . In FIG. 3 , the speakers 18 LS and 18 RS are positioned at 120° left and 120° right, respectively, of the center line 20 . The systems of both FIGS. 2 and 3 include some additional intermediate locations 22 L, 22 R, 24 L, and 24 R where other speakers could be added to the system, if desired. FIG. 3 also includes the additional end locations 26 L and 26 R where still further speakers could be added to the system 10 . Alternatively the speakers 18 LS and 18 RS can be moved to the end locations 26 L and 26 R, respectively. In general the left and right angular displacement of speakers 18 LS and 18 RS can vary between about 105° and 140°, but the angular displacement is desirably consistent from system to system where exact audio reproduction is desired.
[0032] All of the speakers 18 can be located at a distance R from the position X of the listener, where R is generally between about 0.5 m and 1.5 m, which is considerably closer than the range given in the ITU-R BS.1116-1 recommendation. The distance R to all speakers 18 of a given system can be identical. The outside diameter D of the system 10 can be between about 1 m and 3 m. In the system in FIG. 13 , the outside diameter D was constructed to be about 1.2 m so that the radius R was about 0.6 m, thus allowing the listener situated at position X to employ near-field monitoring techniques. Further, the speakers 18 should be positioned away from any adjacent wall by a distance S that is greater than R, so that reflection contributions to the sound being monitored at position X may be minimized. Optional sub-woofers 28 L and 28 R can also be added to the system if desired, and can be located at positions other than that illustrated in FIGS. 2 and 3 . The speakers 18 can be identical to each other, while the subwoofer speakers 28 can be of a different design from speakers 18 .
[0033] The positions of the speakers 18 relative to the listener, and relative to each other, can be dictated by a mechanical coupling 30 . The mechanical coupling 30 can be designed to have minimal interference or reflective character so that the acoustic impact on the sound field developed by the speakers 18 may be insignificant. The mechanical coupling 30 can include a plurality of intermediate spacing elements 32 as well as end spacing elements 34 as shown in FIGS. 4 and 5 , respectively. The spacing elements 32 and 34 forming the mechanical coupling 30 can be formed of hollow rigid members such as metal or plastic tubing, which can have any desirable cross-sectional shape. Adjacent spacing elements 32 and 34 can be joined to each other by end structures 36 including releasable portions enabling the system 10 to be easily assembled and disassembled for transport from one location to another location. The end structures 36 can include a hinge so that the mechanical coupling 30 can be folded into a stack as shown in FIG. 5 . The spacing elements 32 and 34 desirably have a uniform length L, which will be determined at least in part by the overall dimension D selected for the system 10 . The length L adopted for the systems illustrated in FIGS. 2, 3 and 13 can be about 0.6 m. The length L adopted for the system illustrated in FIG. 14 will generally be greater than 0.6 m to permit more than one person to occupy a position in the immediate vicinity of the central position X. The spacing elements 32 and 34 can include a medial bend 38 , as shown in FIGS. 4 and 5 , which in the illustrated system defines an included angle α of 150°. This medial bend 38 could be replaced by suitable end structures 36 that provided a suitable angular displacement for the spacing elements 32 and 34 .
[0034] The mechanical coupling 30 that includes hinges at the end structures 36 can be easily deployed by unfolding the stack shown in FIG. 6 in the manner shown by the arrows A in FIG. 7 . C-shaped locking channel members 40 can be used to secure the spacing elements 32 and 34 in a coplanar relation to each other at a generally horizontal attitude. A plurality of standards 42 can be provided to support the mechanical coupling 30 . As generally indicated in FIGS. 8 and 9 , each standard 42 can include a plate member 44 that can be fixed in spaced relation to the end 46 of the standard 42 . The spacing between the plate member 44 and end 46 can be sufficient to receive the tubing wall defining the spacing elements 32 and/or 34 opposite a hinge 36 . Additional extension members 48 can be added to the ends 50 of the standards 42 opposite end 46 to permit the mechanical coupling to be suitably position vertically in generally planar alignment with the head of the listener located at position X. The vertical displacement of the speakers 18 supported by the mechanical coupling 30 may be no more than about ±15°, and the vertical angular displacement is desirably consistent from system to system where exact audio reproduction is desired.
[0035] Alternatively, each standard 42 can include a U-shaped channel member 43 as shown in FIG. 10 . The U-shaped channel member 43 can be fixed to the upper end of each standard 42 and have two upstanding arms 45 separated from each other by a dimension designed to receive one of the spacing elements 32 or 34 of the mechanical coupling 30 . A hole 47 can be provided in each of the upstanding arms 45 . Additional holes 49 can be provided at designated points along the spacing elements 32 and 34 . A clevis pin, bolt, screw or other fastener 51 can pass though the holes 47 and 49 to couple the upstanding arms 45 to the spacing element 32 or 34 that can be received in the U-shaped channel member 43 .
[0036] Each of the spacing elements 32 and 34 can contain wiring 52 suitable to connect the amplifier outputs 16 to the speakers 18 through jacks 54 as shown in FIGS. 11 and 12 . The jacks 54 can be arranged in pairs so that each speaker 18 can be connected to the contained wiring 52 within the spacing elements 32 and 34 by engagement of two jacks 54 . In the case of the intermediate spacing elements 32 , one jack 54 can be situated adjacent to each end 56 . In the case of the end spacing elements 34 , a single jack 54 can be provided adjacent the end 56 having a hinge or other end structure connection to an adjacent intermediate spacing element 32 . At the terminal end 58 of the end spacing elements 34 , a pair of jacks 54 can be provided as shown in FIG. 5 .
[0037] A representative speaker 18 , shown in FIG. 12 , has an enclosure 60 having two protruding prongs 62 that can be engaged in the jacks 54 on opposite sides of an end structure 36 joining two adjacent spacing elements 32 and 34 . The speaker enclosure 60 , which preferably has a contained volume of between about 0.5 and 1.5 liters, can be secured to the spacing elements by fasteners 64 in the nature of screws or bolts. Where the speakers 18 are employed at the junction of two spacing elements, the use of locking channel members 40 can be omitted since the speaker enclosure 60 when secured by fasteners 64 will ensure that the contiguous spacing elements will be retained in a fixed orientation with respect to each other. The speakers 18 can be any of a wide variety of speakers, however all the speakers 18 secured to the spacing elements of a given mechanical structure 30 should be as consistent in performance as possible. For example, the speaker enclosures 60 can include a multi-transducer grouping, and the amplifier 12 can include suitable controls for adjusting the output of each transducer within the multi-transducer grouping. The speakers 18 are desirably consistent from system to system where exact audio reproduction is desired. The speakers 18 desirably have a substantially flat sound reproduction range from 80 Hz to 20 kHz, and a power handling capability of at least about 15 Watts. By using the same speaker design at all locations, the amplitude and phase characteristics of each speaker's sound filed is the same. This provides a more coherent sound field which improves the spatial sound reproduction aspects of the sound field therefore improving the transparency and naturalness of the reproduced sound.
[0038] One possible spatial array sound reproduction system 10 that could be used by sound engineers, computer gamers, and others is shown in FIG. 13 . A mechanical assembly 30 can be provided that can be supported by, and may be coupled to, a desk 66 . A television or computer screen 68 can be centrally situated on the desk 66 immediately below speaker 18 CF. The mechanical assembly 30 includes spacing elements 32 and 34 that situate the other speakers 18 LS, 18 LF, 18 RF and 18 RS at known, fixed distance from each other as well as a central listening point located above a front edge 70 of the desk 66 . The speakers 18 can be coupled to a multi-channel amplifier 12 of standard surround sound reproduction system or a multi-channel signal processing amplifier that can be controlled in various known ways to reproduce a desired acoustic experience. Vertical standards 42 can be coupled to the spacing elements 32 and 34 , and can be coupled to the desk 66 to support the speakers 18 at a desired height, which can be adjustable to accommodate stature differences among listeners.
[0039] The vertical standards closest to the screen 68 can be omitted by supporting the spacing elements 32 on the screen 68 . In such an installation, it may be desirable to include at least some magnetic shielding adjacent to the speakers 18 so as to not cause interference with the operation of the screen 68 . A single subwoofer speaker 28 is shown to be situated under the desk 66 , however, any number of subwoofer speakers can be included in the system. It will be appreciated that the height of the desk 66 can be designed for use with a chair, not shown, or could be design to be used by a listener who may be standing rather than sitting. The desk 66 can be a standard permanent desk design, or a portable desk designed for easy assembly and disassembly, similar to the previously described mechanical assembly 30 , so that the entire system 10 shown in FIG. 13 can be transferred from location to location to ensure accurate sound reproduction in a variety of locations thereby auralizing the characteristics of any selected venue at a second venue.
[0040] For example, a portable spatial array sound reproduction system 10 such as that shown in FIG. 13 can be positioned at a selected venue of interest and the sound characteristics of the venue matched by suitable modification of the various gain controls of the amplifier system 12 . The system 10 can then be moved to any other location and the controls returned to the levels matching the venue of interest with assurance that the sound produced by the system 10 will match the sound produced at the venue of interest. Additionally, the information concerning the various gain control levels can be communicated to others having a similar system 10 to permit the recipient to also reproduce the sound characteristics of the venue of interest. If the second location to which the system 10 is moved also has a resident sound system, it is even conceivable that one could calibrate the resident sound system of the second location to inherently have the sound characteristics of the venue of interest using the portable system 10 as a calibration standard.
[0041] FIG. 14 shows another possible spatial array sound reproduction system 10 that could be used for sound evaluation training, or in a home theatre installation, and other similar situations. A mechanical assembly 30 can be provided that can be suspended from a ceiling 72 by the vertical standards 42 , which could be adjustable manually or automatically to change in height. Preferably, the vertical position of the speakers 18 should be such that the angular elevation of the speakers is not more than about 20° above the horizontal plane of the listener's ear level. A visual presentation screen 68 can be situated adjacent to a wall 74 of the room above a console 76 that can contain one or more subwoofers 28 . A seating location 78 , which may be designed to accommodate more than one person, may be provided in line with the visual presentation screen 68 and the speaker 18 CF mounted on the assembly 30 . The mechanical assembly 30 can include spacing elements 32 and 34 that situate the other speakers 18 LS, 18 LF, 18 RF and 18 RS at known, fixed distance from each other as well as the seating location 78 . The speakers 18 can be coupled to a multi-channel amplifier 12 of standard surround sound reproduction system or a multi-channel signal processing amplifier that can also be situated in the console 76 and controlled in various known ways to reproduce a desired acoustic experience. The speakers 18 can all be spaced from the walls 74 by a distance that may be greater than the distance between the speakers 18 and the seating location 78 to minimize any reflection, diffraction or other interference with the direct sound field information from the speakers 18 . Using the calibration information developed at a venue of interest as described in the previous paragraph, a sound system 10 located in a playback venue as shown in FIG. 14 can be adjusted to reproduce the same sound characteristics. Additionally, the suitable gain control level information necessary to reproduce the sound characteristics of a musical selection recorded at such a venue of interest can be provided as a part of the reproduced recording or broadcast so that a suitable adjustment of the controls of the sound system of the playback venue can occur automatically, thereby facilitating simultaneous reproduction of the sound characteristics of a venue of interest at a number of different locations.
[0042] FIG. 15 shows another possible spatial array sound reproduction system 10 that could be used in connection with a gaming computer, or for sound evaluation training, or in other situations. A mechanical assembly 30 can be provided that can be supported by the computer screen 68 , and may be coupled to desk 66 . The computer screen 68 can be centrally situated on the desk 66 so that the computer screen supports speakers 18 CF 18 LF and 18 RF. In such an installation, it may be desirable to include at least some magnetic shielding adjacent to the speakers 18 so as to not cause interference with the operation of the screen 68 . The mechanical assembly 30 can also include spacing elements 32 and 34 forming a part of the desk 66 that situate other speakers 18 LS and 18 RS at known, fixed distance from each other as well as a central listening point located above a front edge 70 of the desk 66 . Additional speakers such as rear speaker 18 RR can be positioned at a spaced location behind the listener or game player to further enhance the surround sound experience. The speakers 18 can be coupled to a multi-channel amplifier 12 of standard surround sound reproduction system or a multi-channel signal processing amplifier that can be controlled, by a gaming computer or other computer in various known ways to reproduce a desired acoustic experience. Vertical standards 42 can be coupled to the spacing elements 32 and 34 , and can be coupled to the desk 66 to support the speakers 18 at a desired height, which can be adjustable to accommodate stature differences among listeners or game players. A subwoofer speaker 28 can be situated under the desk 66 , however any number of subwoofer speakers can be included in the system. It will be appreciated that the height of the desk 66 can be designed for use with a chair, not shown, or could be design to be used by a listener or game player who may be standing rather than sitting.
[0043] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. | A compact portable spatial array sound reproduction system employs a plurality of identical speakers coupled to a mechanical assembly that situates the speakers at a known, fixed distance from each other as well as a central listening point. The speakers can be coupled to a multi-channel amplifier that can be controlled in various known ways to reproduce a desired acoustic experience. The mechanical assembly is designed to be easily assembled and disassembled to permit transport of the system from location to location resulting in the reproduction of the identical acoustic experiences at different locations spaced in time. The system can be employed to standardize the acoustic characteristics of different venues so that uniform aural experiences can be shared simultaneously or sequentially by people at different locations. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of Ser. No. 786,712, filed Apr. 11, 1977, now abandoned, which is a division of Ser. No. 614,243, filed Sept. 17, 1975, issued as U.S. Pat. No. 4,033,989 on July 5, 1977.
BACKGROUND OF THE INVENTION
The present invention relates to novel 9-deoxy-16,16-dimethyl-PGF compounds, including the free acid, pharmacologically acceptable salt and ester forms of 9-deoxy-16,16-dimethyl-PGF 2 .
9-Deoxy-PGF 2 , in both acid and pharmacologically acceptable salt form is described in U.S. Pat. 3,984,009, issued July 8, 1975. This patent further provides a broad generic disclosure of other 9-deoxy-PGF 2 -type compounds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A disclosure of the preparation and pharmacological uses of 9-deoxy-16,16-dimethyl-PGF 2 , its corresponding pharmacologically acceptable salts and esters, is described in U.S. Pat. No. 4,033,989, the disclosure of which is incorporated here by reference. In particular, the instant 9-deoxy-16,16-dimethyl-PGF 2 compounds are useful as gastric anti-ulcer and uterine stimulating agents, in accordance with the methods described in U.S. Pat. No. 4,033,989.
Further, the preferred method for preparing 9-deoxy-16,16-dimethyl-PGF 2 , methyl ester, is described in the following example:
EXAMPLE 1
9-Deoxy-16,16-dimethyl-PGF 2 , methyl ester
A. 6 g of PGF 2 α, methyl ester, 11,15-bis(tetrahydropyranyl ether) is dissolved in 66 ml of methylene chloride and cooled to -20° C. with an ice methanol bath under a nitrogen atmosphere. Thereafter there is added in a single portion 0.26 ml of triethylamine and dropwise over 30 sec 0.90 ml of methanesulfonyl chloride. The ice bath is removed and the resulting mixture stirred for 45 min whereupon TLC analysis indicates the reaction to be complete. Thereafter the reaction mixture is poured into an ice-sodium bicarbonate-hexane mixture and extracted with additional hexane. The hexane extracts are then washed with water, diluted with a mixture of potassium bisulfate, ice, sodium bicarbonate, and brine; washed with sodium sulfate; and concentrated under reduced pressure to yield 16,16-dimethyl-PGF 2 α, methyl ester, 11,15-bis(tetrahydropyranyl ether), 9 mesylate.
B. The tetrahydropyranyl ethers of the reaction product of Part A (about 6 g) are hydrolyzed in a mixture of tetrahydrofuran (10 ml), acetic acid (60 ml), and water (24 ml), yielding 2.8 g of 16,16-dimethyl-PGF 2 α, methyl ester, 9 mesylate.
C. The reaction product of Part B (2.7 g) is dissolved in 25 ml of hexamethylphosphoramide. Thereafter at ambient temperature lithium bromide (about 1.5 g) is added until a saturated mixture is obtained. The resulting mixture is then poured into a water-brine mixture and extracted with ethyl acetate and hexane (60:40). The extracts are then washed with water and brine, dried over sodium sulfate, and concentrated under reduced pressure to yield 2.1 g of crude 9-deoxy-9β-bromo-16,16-dimethyl-PGF 2 , methyl ester. Chromatography on 350 g of silica gel packed with 5 percent isopropanol in hexane yields 1.058 g of pure product.
D. A chromium perchlorate solution (prepared from 2.6 g of chromium metal finely divided and reacted with 50 ml of 2 M perchloric acid under a nitrogen atmosphere with vigorous stirring until the chromium metal is completely dissolved), 25 ml, is added to a solution of 4.17 ml of ethylene diamine in 125 ml of dimethylformamide in water (9:1). Stirring for 5 min at ambient temperature under a nitrogen atmosphere is followed by addition of 1.05 g of the reaction product of Part C and 10 ml of dimethylformamide in water (9:1). After stirring at ambient temperature for 30 min, the resulting mixture is poured into a mixture of ice, brine, water, potassium bisulfate, ethyl acetate, hexane, and extracted with a mixture of ethyl acetate and hexane (1:1). The organic extracts are then washed with water in brine, dried over magnesium sulfate, and concentrated under reduced pressure to yield 915 mg of crude title product. Chromatography on silica gel (80 g) packed and eluted with ethyl acetate in hexane (1:1) yields 658 mg of pure 9-deoxy-16,16-dimethyl-PGF 2 , methyl ester. Characteristic NMR absorptions are observed at 5.7-5.2, 4.1-3.6, 3.4, 0.90, and 0.85δ.
EXAMPLE 2:
9-Deoxy-16,16-dimethyl-PGF 2
The reaction product of Example 1 (350 mg) in methanol is combined with 10 ml of 1 N aqueous potassium hydroxide with stirring under a nitrogen atmosphere. After 4 hr the resulting mixture is poured into brine, acidified with 5 ml of 2 N potassium bisulfate and extracted with ethyl acetate. The ethyl acetate extracts are then washed with brine, dried over magnesium sulfate, and concentrated to yield pure title product (358 mg).
EXAMPLE 3:
A pregnant Rhesus monkey, a standard experimental animal for determining the uterine stimulating potency of prostaglandins and analogs thereof, is given intravenous dosages of the various prostaglandins and analogs listed below according to the procedure of Kimball, F. A., et al., Biol. Reprod. 13:42-49 (1975). The following results are obtained:
______________________________________ Minimum EffectiveCompound Dose (μg)______________________________________PGE.sub.2 10-15PGF.sub.2 α 100-1509-Deoxy-PGF.sub.2 1009-Deoxy-16,16-dimethyl-PGF.sub.2 1______________________________________ | The present invention relates to novel 9-deoxy-16,16-dimethyl-PGF 2 compounds, which are prostaglandin analogs useful for the same pharmacological purposes as the corresponding prostaglandins. In particular, the instant compounds are particularly and especially useful as gastric anti-ulcer agents and are useful in stimulating the pregnant mammalian uterus. | 2 |
This is a continuation of U.S. patent application Ser. No. 08/604,427, filed on Feb. 21, 1996, titled "WET CLEAN OF A SURFACE HAVING AN EXPOSED SILICON/SILICA INTERFACE" now U.S. Pat. No. 5,645,737.
BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention relates to the manufacture of semiconductor devices. More particularly, the present invention is directed to methods for performing a wet clean of a surface having an exposed silicon/silica interface, which wet clean is useful in the manufacture of semiconductor devices. The methods are particularly useful for a post chemical mechanical polishing clean of a surface having an exposed silicon/silica interface.
2. The Relevant Technology
Chemical mechanical polishing is finding increasing application in the manufacture of semiconductor devices to planarize surfaces in preparation for high resolution photolithography and for other purposes. Chemical mechanical polishing involves polishing an uppermost film on the surface of a semiconductor wafer by use of a polishing pad and a polishing slurry. The slurry contains polishing particles. Pad types and slurry compositions vary depending on the material being polished and other factors.
Chemical mechanical polishing is particularly useful where feature sizes of less than 0.5 micron must be defined over a topography already existing on the wafer surface. In such circumstances, a reflowed silica glass layer is insufficiently planar, but with chemical mechanical polishing, sufficient planarity may be achieved to facilitate high resolution photolithography. Chemical mechanical polishing may also be employed to completely remove portions of a layer being polished, so that underlying material is exposed. In either case, a clean step is required after the chemical mechanical polishing to clean polishing slurry from the wafer surface.
Where silica (silicon dioxide) or silicon is the layer being polished, the polishing slurry typically contains silica particles having an average size of about 30 nanometers (nm). The silica particles that remain on a silica surface after polishing are typically removed by a clean process including an HF (hydrofluoric acid solution) dip followed by a deionized water rinse. Silica particles and other contamination remaining on a silicon surface after polishing are typically cleaned in an ammonium hydroxide solution or the like.
Where a silica layer is polished until some silicon is exposed, or where a silicon layer is polished until some silica is exposed, the above typical clean processes can result in problems. While the typical clean process for silica is effective to remove silica particles from a silica surface, a silicon surface is not adequately cleaned. Silica particles tend to collect on the silicon surface and, once the clean process is complete, tend to permanently adhere there, regardless of further cleans. The typical clean processes for silicon are likewise ineffective to remove silica particles from a silica surface. Further, an ammonium hydroxide clean, which etches silicon, can be unacceptable where particularly fine or small silicon structure must be preserved. Accordingly, there exists a need for a clean process which can remove silica particles from both silica and silicon surfaces, and particularly without etching the silicon surface.
SUMMARY AND OBJECTS OF THE INVENTION
An object of the present invention is to provide a method for cleaning a surface having an exposed silicon/silica interface.
Another object of the present invention is to provide a method for removing silica particles from a surface having an exposed silicon/silica interface.
Yet another object of the present invention is to provide a method for cleaning a surface having an exposed silicon/silica interface, which surface was produced by chemical mechanical polishing.
Still another object of the present invention is to provide a reliable, easily performed method of removing silica particles from a surface having an exposed silicon/silica interface.
Still another object of the present invention is to provide a method for cleaning a surface having an exposed silicon/silica interface without significant etching of the exposed silicon.
In accordance with the present invention, a surface having an exposed silicon/silica interface is cleaned by an HF dip, followed immediately by a rinse in an organic carboxylic acid surfactant. A preferred organic carboxylic acid surfactant is citric acid. The organic carboxylic acid surfactant can be pentadecanoic acid or other similar long chain acids. Following the rinse in the organic carboxylic acid surfactant is a rinse in deionized water. Low pH of the organic carboxylic acid surfactant significantly prevents the formation of a charge differential between the silica and silicon portions of the surface, which charge differential would otherwise cause any silica particles present to remain on the silicon portions of the surface. The surfactant properties of the selected organic carboxylic acid helps to remove any silica particles from the surface. The deionized water rinse then removes the organic carboxylic acid surfactant from the surface, leaving a very clean, low particulate surface on both the silica and silicon portions thereof, with little or no etching of the silicon portion.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the manner in which the above-recited and other advantages and objects of the invention are obtained may be more fully explained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments and applications thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments and applications of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 is a flow diagram of a method of the present invention.
FIG. 2 is a partial cross section of a partially formed semiconductor device on which a method of the present invention may be beneficially performed.
FIG. 3 is another partial cross section of a partially formed semiconductor device on which a method of the present invention may be beneficially performed.
FIG. 4 is yet another partial cross section of a partially formed semiconductor device on which a method of the present invention may be beneficially performed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As an overview, the present invention provides a method for cleaning surfaces having silicon and silica exposed, and particularly for removing from such surfaces silica particles left after chemical mechanical polishing. The exposed silicon may be of any type, including for example doped and undoped single crystal silicon, epitaxial silicon, polysilicon, and amorphous silicon. The silica may also be of any type such as doped or undoped, grown or deposited, including any type of silica glass. The inventive method described in detail below successfully removes silica particle contamination from both silica and silicon surfaces without substantially etching the silicon surface.
According to the present invention, a surface having an exposed silicon/silica interface is cleaned by performing the process illustrated in the flow diagram of FIG. 1. The surface is typically a surface of a semiconductor wafer which has been chemically mechanically polished, leaving silica particle contamination.
As a first step, the surface is contacted with hydrofluoric acid. This is preferably achieved by dipping the wafer in hydrofluoric acid. Next, the surface is contacted with an organic carboxylic acid surfactant, which will preferably be citric acid. The organic carboxylic acid surfactant can be pentadecanoic acid or other similar long chain acids. The contact with the surface is preferably achieved by dipping the wafer in citric acid or flowing citric acid, rinsing the wafer in citric acid, spraying the surface of the wafer with citric acid, or a similar technique. Last, the surface is rinsed with deionized water. This may be achieved in any of many ways known to those of skill in the art.
The first step of the process flow shown in FIG. 1, the HF dip, is preferably performed in hydrofluoric acid having preferably a concentration within the range of about 4:1 to about 250:1, and most preferably a concentration of about 100:1. Other known ways of contacting the surface with HF may optionally be substituted for the HF dip.
The second step of the process flow shown in FIG. 1, the citric acid rinse, should be performed soon, and preferably immediately, after the HF dip, and without any intervening rinse in deionized water. If a deionized water rinse were to follow the HF dip, silica particles would collect on the silicon portion of the surface. This is a result of a buildup of charge on the silica particles and the silica portions of the surface. At higher pH values (such as a pH of about 7 as for deionized water) the silica particles and the silica portion of the surface become negatively charged, repelling each other, while the silicon portions of the surface remain neutral or are only slightly negatively charged. The mutual repulsion of the silica particles and the silica portions of the surface tends to concentrate the silica particles on the silicon portions of the surface, and to prevent the silica particles from being removed by translational motion along the surface.
The second step of the process flow shown in FIG. 1, the citric acid rinse, is performed in citric acid of sufficient strength so as to have a pH value preferably within the range of about 2 to about 4, and most preferably about pH 2.2. At these pH levels, no significant charge is built up on the silica particles and silica portions of the surface. The immediate transfer of the surface from contact with HF to contact with citric acid, without an intervening deionized water rinse, keeps the pH low and prevents the silica particles from becoming charged. The surfactant properties of the citric acid assist in washing away the particles, while the low pH prevents the mutual repulsion of the silica particles and the silica portions of the surface, allowing the silicon portions of the surface to be cleaned of silica particles.
In the third step of the process flow shown in FIG. 1, the deionized water rinse, the citric acid is gradually removed from the surface, and the pH level at the surface increases gradually, eventually passing a point at which the silica particles and the silica portions of the surface become charged. By that point, however, the silica particles have been substantially removed from the surface, either by the citric acid rinse or by the initial stages of the deionized water rinse.
Presently preferred applications for the method steps seen in FIG. 1 are illustrated in FIGS. 2-4.
FIG. 2 is a partial cross section of a partially formed semiconductor device showing a substrate 12 upon which a layer of silica 14 such as BPSG has been formed. Layer of silica 14 has been etched away at a certain location, leaving a space 16 therein. A thin layer of silicon has been deposited conformably over substrate 12 and layer of silica 14, then removed by chemical mechanical polishing until only a layer of silicon 18 at space 16 remains. Layer of silicon 18 will function in the completed semiconductor device as the lower capacitor plate of a container capacitor.
The method steps of the present invention are particularly useful to clean a wafer having the structure shown in FIG. 2. The chemical mechanical polishing used to form the structure shown in FIG. 2 leaves silica particles that must be removed. Because both layer of silica 14 and layer of silicon 18 are exposed, a standard HF dip followed by a deionized water rinse causes silica particles to collect on silicon layer 18, particularly on the uppermost upward facing surfaces thereof, near the interface of layer of silica 14 and layer of silicon 18. Because capacitance of a capacitor depends on surface area and hence on such fine features as surface roughness, any clean that etches silicon would negatively impact capacitance of a capacitor formed with layer of silicon 14. The method steps of the present invention avoid both problems by providing a cleaning method that removes silica particles from both silica and silicon without etching silicon.
The method steps of the present invention also finds useful application where planarization of active and isolation regions is desired. FIG. 3 shows a silicon substrate 20 having an active region 22 isolated by field oxide regions 24 and 26. The structure shown in FIG. 3 may be formed by etching a silicon substrate to form an island at the location desired for the active region, then masking the island and growing oxide around the island. Alternatively, the island may be left unmasked and oxide may be grown around and over the island. In either case, the grown oxide is then polished by chemical mechanical polishing back to the level of the unoxidized silicon of the island, resulting in the structure of FIG. 3. The method of the present invention may then be applied to clean the surfaces of active region 22 and field oxide regions 24 and 26.
Further beneficial use of the present invention may be found where silicon plugs are isolated and planarized by means of chemical mechanical polishing. FIG. 4 shows a substrate 28 having raised structures 30 such as gate stacks formed thereon. Raised structures 30 are enclosed in a layer of spacer material 32 over which a layer of silica 34 such as BPSG has been conformably deposited. A space 36 has then been etched in layer of silica 34 down to substrate 28 with an etch process selective to spacer material 32. A layer of silicon such as doped polysilicon has then been deposited conformably over substrate 28, spacer material 32, and layer of silica 34. The layer of silicon is then polished by chemical mechanical polishing back to the level of layer of silica 34, resulting in a silicon plug 38. The method of the present may then be applied to clean the exposed surfaces of layer of silica 34 and silicon plug 38.
The method of the present invention may further be beneficially applied in virtually any process requiring a clean of a surface having an exposed silicon/silica interface, particularly where silica particles or any other particles with similar electrical characteristics are present.
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. | A surface having an exposed silicon/silica interface is cleaned by ah HF dip, followed immediately by a rinse in citric acid, followed by a rinse in deionized water. Low pH of the citric acid significantly prevents the formation of a charge differential between the silica and silicon portions of the surface, which charge differential would otherwise cause any silica particles present to remain on the silicon portion of the surface. Surfactant properties of the citric acid help remove any silica particles from the surface. The deionized water rinse then removes the citric acid from the surfaces, leaving a very clean, low particulate surface on both the silica and silicon portions thereof, with little or no etching of the silicon portion. | 2 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable
REFERENCE TO A "MICROFICHE APPENDIX"
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to bags of one or more layers, wherein at least one layer may be fabricated from paper or plastic material, for the containment and dispensing of fluent material.
2. Description of the Related Art Including Information Disclosed under 37 CFR 1.97 and 1.98
Bags for the containment and dispensing of fluent material, such as dry dog food or cat litter, which are fabricated from one or more layers, wherein at least one layer may be fabricated from paper or plastic, are well known. One such type of bag is known as a stepped-end, folded-over, pinch bottom bag (hereinafter "pinch bottom bag").
Such a bag may be fabricated from one or more layers of plain, untreated paper, although typically, one or more layers may be fabricated from a fine-grain, siftproof paper. In addition or alternatively, one or more of the layers may be fabricated from an inherently moisture-proof material, such as polyethylene, or treated paper. The several layers of the bag are aligned atop one another and, while still in a continuous web, formed into a tube. As the tube is cut into individual bag tubes, the ends of each bag tube may be cut in a stepped fashion, to create a stepped progression of layers on both sides of the opening of such a flattened bag. The exposed mating stepped surfaces of one or both sides may be provided with a heat-sealable coating or may themselves be heat-sealable (in the case of polyethylene layers).
Typically, the "top" of the bag (the end the ultimate product customer opens) is folded over, and passed through a heat-sealing device to close an end of the bag. The opposite end of the bag (usually the bottom) is left open by the bag manufacturer, so that the customer of the bag (the product producer) can fill the bag with product, and then seal the bag.
In the simplest form of such a bag, once both ends have been sealed shut, the bag can only be opened by tearing or cutting. Once opened, the sealed condition of the bag is lost, and the contents are exposed to air, humidity, spillage, and the possibility of intrusion of contaminants, etc. If not all of the contents are to be used at once, the only options for reclosure of the bag, are folding or rolling down the opened top, or using some kind of cinch closure (twist-ties and the like). Alternatively, if a greater degree of protection for remaining unused contents is required, usually, the contents must be tipped into a reopenable/resealable container, such as a lidded metal or plastic drum or the like.
Accordingly, it would be desirable to provide a multi-layer bag, for example, of the stepped-end, pinch bottom variety, which is susceptible of opening, without having to excessively tear or cut the material of the bag, so that the bag is capable of substantially truly sealable reclosure in a facilitated manner.
It would further be desirable to provide a multi-layer bag, for example, of the stepped-end, pinch bottom variety, which is provided with a spout or opening, which can be opened and closed repeatedly, until all of the contents of the bag have been dispensed from the bag.
These and other objects of the invention will become apparent in light of the present description, claims and drawings.
BRIEF SUMMARY OF THE INVENTION
A bag apparatus, having a repeatedly openable and reclosable pour spout, comprises a tubular bag body, fabricated from at least one layer of bag material, in which the tubular bag body has at least one end configured to form an open mouth and having first and second opposing sides adjacent the mouth. A closure flap emanates from the first of the opposing sides of the mouth, and is operably configured to be folded across the mouth and over at least a portion of an outer surface of the second of the opposing sides of the mouth.
The closure flap has an inside surface operably configured to be placed in juxtaposed alignment over the at least first portion of the outer surface of the second of the opposing sides of the mouth.
A spout structure is operably affixed to a portion of the outside surface of the tubular bag body, including a base sheet, operably positioned on and over at least a further portion of the portion of the outer surface of the second of the opposing sides of the mouth, the base sheet having an outside surface; a spout flap, operably disposed in substantially aligned overlying contact with the base sheet; and a first adhesive material operably disposed on at least one of the inside surface of the spout flap and the outside surface of the base sheet, the first adhesive material being operably disposed to releasably hold the spout flap to the base sheet, after the spout flap and the base sheet have been brought into the substantially aligned overlying contact with each other.
The spout structure is operably disposed on the further portion of the portion of the outer surface of the second of the opposing sides of the mouth, so that upon operable positioning of a second, substantially non-releasable adhesive material upon the inside surface of the closure flap and further upon the juxtaposed alignment of the closure flap over and against the portion of the outer surface of the second of the opposing sides of the mouth, the spout flap becomes non-releasably affixed to a portion of the inside surface of the closure flap.
Complete separation of the spout flap from the base sheet enables a portion of the mouth of the bag to be reopened for providing access to an interior region of the tubular bag body, the first adhesive material permitting the spout flap and base sheet to be repeatedly separated and releasably reattached to one another, to, in turn, permit at least a portion of the mouth to be repeatedly opened and reclosed.
The spout flap preferably further comprises at least first and second flap sheets laminated to one another. The at least first and second flap sheets may be fabricated from different materials.
The first adhesive material is preferably disposed to remain on the spout flap, upon separation of the spout flap from the base sheet. Alternatively, the first adhesive material may be disposed to remain on the base sheet, upon separation of the spout flap from the base sheet.
The base sheet preferably comprises a sheet, fabricated from a polymer-based material.
The first adhesive material preferably comprises at least one material from the group consisting of polyesters, polyethylenes, polyamids.
The spout structure is preferably operably disposed upon the further portion of the portion of the outer surface of the second of the opposing sides of the mouth so that, after the juxtaposed alignment of the closure flap over the portion of the outer surface of the second of the opposing sides of the mouth and non-releasable affixation of the spout flap to the closure flap, upon initial separation of the spout flap and the base sheet, and upon continued pulling of the spout flap, a portion of the closure flap, to which the spout flap is non-releasably affixed, becomes partially separated from a remaining portion of the closure flap, for facilitating partial opening of the mouth of the bag.
Preferably, portions of the inside surface of the spout flap and of the base sheet are left free of the at least one adhesive material, so that an object may be inserted between the portions of the inside surface of the spout flap and the base sheet, for facilitating grasping of the spout flap, toward permitting pulling of the spout flap away from the base sheet.
The bag body is preferably formed from a plurality of layers of bag material. In a preferred embodiment of the invention, at least one of the layers of bag material is fabricated from paper. In an alternative embodiment of the invention, at least one of the layers of bag material is fabricated from a plastic material.
The bag body may be gusseted. Further, the bag body may be fabricated from a plurality of layers of bag material, with the at least one end of the bag being cut to form a stepped end.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a front elevation of a substantially flattened, prior art, multi-layer, stepped-end, pinch bottom bag, which is unsealed.
FIG. 2 is a top perspective view of the prior art bag of FIG. 1, partially spread open.
FIG. 3 is a side elevation, in section, of the prior art bag of FIGS. 1 and 2, taken along line 3--3 of FIG. 2.
FIG. 4 is a front elevation of a substantially flattened, multi-layer, stepped-end, pinch bottom bag, with reclosable pour spout according to the principles of the present invention.
FIG. 5 is a top perspective view of the bag of the present invention of FIG. 4, partially spread open.
FIG. 6 is a top perspective view of the bag of the present invention of FIGS. 4 and 5, taken along line 6--6 of FIG. 5.
FIG. 7 is a perspective exploded view of the reclosable spout structure of the present invention, according to one preferred embodiment.
FIG. 8 is a perspective view of the reclosable spout structure of the present invention, according to the embodiment of FIG. 7.
FIG. 9 is a front elevation of the bag of the present invention of FIGS. 4-8, after the end of the bag has been sealed, but before initial opening by a user.
FIG. 10 is a front elevation of the bag of the present invention of FIGS. 4-9, after the end of the bag has been sealed, and after the spout of the bag has been initially opened.
FIG. 11 is a perspective view of the spout flap, from the bottom, showing the pattern of adhesive material.
DETAILED DESCRIPTION OF THE INVENTION
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will be described in detail herein, a specific embodiment, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.
FIGS. 1-3 illustrate one end of a prior art stepped-end cut, multilayer pinch bottom bag 10. Typically, both ends of the bag are substantially identical in the manner in which the ends are stepped. Accordingly, only one end is illustrated. Bag 10 has four layers 12, 14, 16 and 18 (though greater or fewer layers may be provided), which are formed from webs and rolled into a tube body 20, in the conventional manner known in the art. Typically, at least one of the layers is fabricated from paper material. Often, one or more layers of the bag may be fabricated from a plastic material, such as polyethylene. When tube body 20 is flattened, two side gussets 22 and 24 may be formed. These in-folded gussets 22, 24 are retained, when the "top" of the bag is sealed shut, for transportation of the bag to the customer for filling with product.
To enable sealing of the bag, the "inside" surfaces of the layers forming the "flap" portion 26 of the open end may be coated with a heat- or sonically-activatable material 27, indicated by the stippling in FIG. 1. The closure flap 26 may be folded over, and the heat or ultrasonic vibrations applied, to activate the glue. After filling of the bag, the same procedure may be applied to the "customer" end of the bag. Alternatively, a hot melt glue may be applied and the closure flap 26 folded over while the glue is still tacky.
As described elsewhere herein, once both ends of the bag have been folded over and sealed, in order to gain access to the materials inside of the bag, the bag material itself be pierced, cut or torn, thus leaving a non-sealable, and virtually non-closable remnant. This may be acceptable, if the entirety of the contents of the bag is to be used at once, or if spillage, contamination or other degradation of the contents are not critical. However, if an unused portion will be left, such as in the case of dry dog or cat food, or moisture or humidity-sensitive materials, such as cement or plaster mixes, among other possible examples, then the contents might become moldy, stale or otherwise compromised, via exposure to air, moisture and/or intrusion of contaminants.
The multilayer bag of the present invention, illustrated in FIGS. 4-10, addresses such problems. Bag 50, apart from the reclosable spout components described hereinafter, may have a construction substantially identical to the bag illustrated and described with respect to FIGS. 1-3. The bag may be fabricated entirely from layers of paper, entirely from layers of plastic or any combination thereof. Typically, both ends of bag 50 may be substantially identical in the manner in which the ends are stepped. Therefore, only one end of bag 50 is illustrated. Bag 50 may have four layers 52, 54, 56 and 58 (though a greater or lesser number of layers may be provided), which are formed from webs and rolled into a tube body 60, in the conventional manner known in the art. Preferably, innermost layer 58 is a plastic material that may or may not be heat sealable. When tube body 60 is flattened, two side gussets 62 and 64 may be formed. These in-folded gussets 62 and 64 are retained, when the "top" of the bag is sealed shut, for transportation of the bag to the customer for filling with product.
The open end of the substantially flattened bag 50 defines a mouth 68, formed by the short step 69 (the stepped-cut portions of the front side of the bag, as seen in FIG. 5) and the long step 70 (the stepped-cut portions of the back side of the bag, as seen in FIG. 5). Closure of the end of the bag involves folding the closure flap 66, which is formed by upper portions of short step 69, and exposed portions of long step 70. Folding of closure flap 66 involves folding a portion of short step 69 upon itself. A rectangular cut 59 is provided in layers 56 and 58 of the short step 69, so that when the long step 70 is folded over, layer 58 of the long step is affixed to flap sheet 75 of spout structure 71.
To enable sealing of the bag, the "inside" surfaces of the layers forming the "flap" portion 66 of the open end may be coated with a heat or sonically activatable material 67, indicated by the stippling in FIG. 4 only. Heat or sonically activatable material 67 is preferably a polyethylene-based hot melt applied adhesive, although other materials having similar operational characteristics may be employed. The adhesive preferably covers the entire height of long step 70, above the top edge 51 of short step 69 (which defines the mouth 68, as seen from the side), but only a portion of the short step 69, stopping well above fold line 53, located at approximately the top edge of layer 54 of short step 69. Specifically, preferably, when the adhesive 67 is applied, it will preferably extend down the exposed surfaces of the short and long steps, to about the bottom of cut 59. The closure flap 66 may be folded over, and the heat or ultrasonic vibrations applied, to activate the glue. Typically, the bag end shown in FIGS. 4-10 is the end that is closed and sealed, prior to shipment of the bag to the bag customer (packager). After filling of the bag, the same procedure may be applied to the "customer" end of the bag. Alternatively, a hot melt glue may be applied and the closure flap 66 folded over while the glue is still tacky.
Reclosable spout structure 71 of bag 50, according to a preferred embodiment of the present invention, as shown in particular detail in FIGS. 7 and 8, incorporates base sheet 72 and spout flap 73. base sheet 72 is preferably fabricated from a polymer material, such as polyester or Mylar®, for example. Spout flap 73 is a laminated structure that may include first flap sheet 74 (which may likewise be fabricated from a polymer material, such as polyester or Mylar®). Second flap sheet 75 preferably may be fabricated from a paper material, such as a bleached, semigloss, clay-coated paper, of the type known in the industry as C1S. Preferably, flap sheet 74 and flap sheet 75 are laminated together in a substantially permanent manner, to resist separation, during ordinary use of the reclosable spout structure.
In order to provide releasable adhesion of first flap sheet 74 to base sheet 72, an adhesive material 76 is applied to the underside surface of first flap sheet 74, the side that becomes juxtaposed to base sheet 72. See, e.g., FIG. 11. Adhesive material 76 is applied in a pattern of thin, elongated stripes, which are spaced apart. A gap 77 in the stripes, is provided, so that when sheet 74 is releasably affixed to base sheet 72, a finger or implement may be inserted between sheet 72 and sheet 74, at the location of the gap, to facilitate grasping and separation of sheets 74 and 75, from sheet 72. While only four stripes of adhesive 76 are shown on each side of gap 77, preferably a substantially greater number of stripes, e.g., about 20 or so, are provided, on each side of gap 77, with each stripe having a width on the order of 1/16 inch. The stripes are preferably separated by narrow gaps, which may be on the order of 1/32 inch. The adhesive material itself may be fabricated from a polymer adhesive material, such as a polyester, a polyethylene or a polyamid. It is believed that the stripe-gap-stripe pattern contributes to the releasability of sheet 72 from sheet 74.
Preferably, spout structure 71 is fabricated as a single unit, for example with sheets 72, 74 and 75 beginning as elongated webs which are joined together, with permanent adhesive joining the webs forming sheets 74 and 75 and the patterned adhesive 76 joining the webs forming sheets 74 and 72, to form a single elongated web, which is then rolled into a coil. Such materials are presently commercially available (with or without the web forming sheets 75), for example, from 3 Sigma LLC, 1985 W. Stanley Road, Troy, Ohio 45373-2330. Afterward, the roll is then cut and/or split into separate "labels", which, in the present invention, are applied, using conventional label applying techniques and equipment, to the outer surfaces of the bags, as shown in FIGS. 4-6. The adhesive that is used to affix spout structure 71 to bag 50 preferably is a permanent adhesive, such as an adhesive hot melt or an acrylic adhesive, such as polyvinyl acetate or polyvinyl alcohol.
Sheet 75 may be provided, constituted as described hereinabove, to permit its upper exposed surface to receive printing, for example "how to open" type instructions, etc. In addition, beneath base sheet 72, a sheet of paper, such as 40# kraft paper, may be provided, that is directly affixed to the face surface of the bag. Such an optional further base sheet 100 is shown, in broken lines, in FIG. 8.
In a preferred embodiment of the invention, as shown in the figures, flap sheet 74, flap sheet 75 and base sheet 75 are all cut with substantially the same shape and dimensions, for forming integrated spout flap 73. Alternatively, base sheet 72 may be cut, during the "label" forming process of cutting the individual spout structures 71, from the roll of material, to have a similar shape but slightly larger dimensions than spout flap 73. This would result in a peripheral gap between the edges of spout flap 73 and base sheet 72.
In a preferred embodiment of the invention, during manufacture of the bags, a plurality of otherwise conventional bags 50 are fabricated in a manufacturing line, using known manufacturing techniques and apparatus. Spout structures 71 are fabricated, as previously described, as integrated pre-assembled units (per FIG. 8) and affixed, in succession, to the fabricated bags 50, in a manner similar to that by which labels are "blown" onto bag structures, using known label applying techniques and apparatus.
FIGS. 4-6 illustrate a completely fabricated bag, with reclosable pour spout structure, according to a preferred embodiment of the invention, prior to final closing of the manufacturer's end of the bag. After affixation of spout structures 71, closure flap 66 is closed, leaving the opposite end of the bag open, for filling by the bag customer and subsequent sealing for distribution to the vendors and ultimate consumers.
The completed bag 50, with spout structure 71 in place, is shown in FIGS. 4-6. Prior to transmittal of the bag to a customer for filling, closure flap 66 is folded over and sealed. When adhesive 67 is applied or activated, and flap 66 is folded over, the portion of layer 58 of the long step 70, that is exposed by cut 59, contacts and becomes affixed to the uppermost portion of flap sheet 75. The portions of the short step 69, that are between the top edge of flap sheet 75 and the bottom edge of cut 59 are, by virtue of the described placement of adhesive 67, substantially untouched by adhesive. In addition, flap sheet 75 is attached by adhesive, preferably not to any part of the short step 69, but instead to the long step 70.
The operation of opening bag 50 is demonstrated in FIGS. 9 and 10. The opposite end of the bag is still open. The bag is then transmitted to the "customer" who will fill the bag with product, and then close the end opposite the end having spout structure 71. FIG. 9 illustrates the end of bag 50, when fully closed. As mentioned above, by inserting a finger or an implement between base sheet 72 and flap sheet 74, at gap 77 (see FIG. 11), flap sheets 74, 75 may be grasped and pulled away from base sheet 72. When the bag is fully closed, a blade or fingernail may be inserted between base sheet 72 and spout flap 73, to "pry up" the spout flap 73 from base sheet 72. Gusset 22 is freed, and a portion of mouth 68 is exposed, permitting access to the interior of the bag. Specifically, a portion of the mouth 68, defined by the short step by the bottom edge of cut 59 of layers 56, 58, and by the torn portion of the long step 70, and attached flap sheets 74, 75. See FIG. 10.
Adhesive 76 will remain attached to the underside of sheet 74. The adhesive connecting base sheet 72 to the bag (or, if sheet 100 is used, the adhesive between sheet 100 and the bag, and between sheet 72 and sheet 100) must be sufficiently strong to prevent separation of sheet 72 from the bag (or prevent separation of sheet 100 from the bag and/or prevent separation of sheet 72 from sheet 100), as sheets 74, 75 are pulled up away from sheet 72. Preferably, adhesive 76 is sufficiently durable so that it will permit repeated separations and re-affixations of sheets 74 and 72. After the initial opening, gusset 22 is pulled out, and the opening thus forms an open pouring spout.
In the embodiment of FIGS. 9 and 10, the first opening of bag 50 results in a partial tearing of the closure flap 66 adjacent the inside edge of the spout flap 73. To provide a more controlled opening of the bag mouth 68, cuts 80 may be placed in layers 58, 56 of long step 70, at a transverse position substantially aligned with the vertical edge of cut 59, and having a height substantially equal to the vertical edge of cut 59. Cuts 80 also reduce the total number of layers, which must be initially torn.
Reclosing and resealing of bag 50 becomes a simple matter of refolding spout flap 73 back down onto and against base sheet 72, and pressing firmly, so that still-tacky adhesive 76 re-engages flap sheet 72. Preferably, the material and pattern of adhesive 76 will permit up to 10 or 20 openings and reclosings before final degradation of the releasable adhesive connection.
As described hereinabove, in the preferred embodiment of FIGS. 4-10, separation of the spout flap 73 from base sheet 72 results in the adhesive material remaining on sheet 74, instead of remaining on sheet 72.
Alternatively, spout structure 71 may be configured so that the adhesive 76 remains on the base sheet 72, upon separation of sheet 74 from sheet 72, if so desired.
The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention. | A bag for the containment of fluent material, having an openable and reclosable pour spout. The bag includes a tubular bag body, and at least one flattened end forming a bag mouth. A closure flap emanates from one side of the bag mouth, to be folded over across the mouth to close the bag. A spout structure is affixed to an outer surface of one of the sides of the bag mouth. The spout structure includes a base sheet affixed to the bag body, and a spout flap releasably affixed to the base sheet. Upon sealing of the bag end, the spout flap becomes non-releasably affixed to an inside portion of the closure flap of the bag body. The spout flap is separable from the base sheet, via a first adhesive material is affixed to one or both of the spout flap and base sheet, for enabling repeated opening and reclosing of a portion of a portion of the bag mouth at the spout flap. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to containers and more particularly to a container adapted to hold cigarettes, plastic adhesive strips (i.e. Band-Aids®), crayons, or other rod-like elements.
SUMMARY OF THE INVENTION
The container is in the general form of a rectangular parallelepiped and is formed by suitably scoring, cutting, bending, and folding a one-piece blank, the blank being formed of a sheet of paperboard or other generally stiff, resilient and foldable material.
After filling and closing the container to form a package, opening is carried out by breaking certain several perforated lines to thereby define a main body portion and a box-like reclosable lid carried by and hinged to the rear wall of the main body portion. A post is positioned at each end of the upper edge of the front wall of the main body, the posts formed by integral, folded panel portions. The box-like lid carries lid guide panels within it for the purpose of guiding the lid to its desired closed position. The lid guide panels also cooperate with the posts to frictionally maintain the box-like lid in its closed position. The contents of the container are loaded from the side of the container prior to final closure at the packager's production facility, where the flat blanks of this invention are folded, filled and closed to form the complete package. Side loading is an easier method of loading a product in those cases wherein the product is to be dispensed or removed from the container while the product is in a vertical position.
The full nature of the invention will be understood from the accompanying drawings and the following description and claims. It should be understood, however, references in the following description to terms such as left, right, base, front, rear and side wall members or panels are for convenience of description, and such terms are not intended to be used in a limiting sense.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a single or one-piece blank of paperboard, cardboard or similar material which is suitably cut and provided with hinge lines to form the container/package of this invention when folded, filled and glued.
FIG. 2 is a perspective view of the blank of FIG. 1 partially folded.
FIG. 3 is a perspective view, similar to FIG. 2, showing a subsequent folding stage.
FIG. 4 is a view illustrating the completed container.
FIG. 5 is a view of the container when opened to thereby form a hinged and reclosable box-like lid.
FIG. 6 is a view taken along section 6--6 of FIG. 4.
FIG. 7 is a view taken along section 7--7 of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 of the drawings, the numeral 10 denotes generally the blank from which the container of this invention is formed. The blank is formed of cardboard, paperboard, or other stiff, resilient and foldable material. The axis L denotes the central longitudinal axis of the blank, and the reader will observe that the blank exhibits mirror symmetry about this axis, i.e., the configuration of the right hand portion of the blank, if folded about axis L, would match the configuration of the left portion of the blank. In the following description of the blank, as well as of the completed container, the term upper will refer to the upper portions of the blank or any part thereof, while the term lower will refer to the lower portions of the blank or any part thereof. Similarly, the term inner will refer to portions towards axis L, while the term outer will refer to portions more remote from axis L.
In FIG. 1, the dashed lines indicate fold or hinge axes, while the solid lines indicate cut lines extending completely through the blank. Further, the adjectives front, bottom, etc. will also refer to, in describing FIG. 1, those front, bottom, etc. portions of the container defined by the blank after its folding.
The numeral 14 denotes the front panel, the upper portion of which is denoted by the numeral 16 with severable perforated line 56 running between them. Top box-like lid panel 18 is hingedly connected to the top of portion 16. Rear box-like lid panel 20 is hingedly connected to panel 18. Rear container panel 22 includes a transverse hinge line 21, with the upper edge of panel 22 hingedly connected to bottom panel 24. Post-forming panel 26 is hingedly connected to the top of panel 24. The upper edge of post-forming panel 26 is centrally recessed as denoted by the numeral 30, the central recess including an upper edge portion 32. The numeral 34 denotes those portions of panel 26 which are above edge 32. The numeral 36 denotes the upper portion of post-forming flaps 40, each of which is hinged to a respective side of panel 26. The numeral 42 denotes bottom side flaps hingedly connected to the sides of bottom panel 24, flaps 42 adapted to reinforce the sides of the container. The numeral 44 denotes side flaps 44, these flaps being hingedly connected to the sides of panel 22. The numeral 46 denotes a severable, perforated line whose inner end commences at an outer end of hinge line 21 and extends to the edge of flap 44. The numeral 48 denotes a flap portion integral with flap 44 and which is also hingedly connected to the ends of panel 20. The numeral 50 denotes 1 friction flap hingedly connected to respective edges of panel 18, the outermost or free edge of flap 50 being curved as denoted by the numeral 52. Flap 54 is hinged to the ends of panel portion 16, with numeral 55 denoting a severable perforated line running from the free edge of flap 54 to an edge of front panel 14. The numeral 58 denotes a side flap hingedly connected to the ends of panel 14. Flaps 58 and 54 are termed first side wall flaps, while flaps 44 and 48 are termed second side flaps.
The numeral 62 denotes an adhesive pattern at the bottom of panel 26, and the numeral 64 denotes a similar adhesive pattern at the bottom of panel 14. As will later be apparent from the mode of folding the blank of FIG. 1 to form the container of this invention, both adhesive patterns 62 and 64 are not necessary, only one being required for assembly. It will be further understood that adhesive patterns 62 and 64 lie on opposite surfaces of the blank of FIG. 1, as will be evident from the latter description, adhesive patterns 62 and 64 may be omitted, with corresponding patterns being simply deposited on the blank during the folding operation.
The numeral 70 denotes either one of two fold lines or axes running parallel to axis L about which the flaps 40, 42, 44, 48, 50, 54 and 58 hinge to their respective panels.
Referring now to FIGS. 2 and 3 of the drawings, the manner of initially forming the container of this invention is illustrated. Panels 24 and 26 are folded as indicated, with panel 26 overlying and being parallel to panel 22. As the next step, panels 18 and 14 are folded, about the hinge line joining panels 20 and 18, so that panel 18 is parallel to bottom panel 24. Next, panel 14 is folded about the hinge line connecting panels 18 and panel portion 16, so that panel 14 overlies panel 26. This is illustrated at FIG. 3 of the drawings. Adhesive pattern 62 or pattern 64 is employed to secure panels 14 and 26 together.
The structure shown at FIG. 3 of the drawings is commonly referred to in this art as a tube. Next, a prewrapped packet 74 of elongated cylindrical elements 76, such as crayons, is inserted by pushing it into one of the open ends of the tube of FIG. 3.
The end closure flaps of the tube are now folded in the following sequence. Flaps 42 and 50 are folded inwardly. Next, flap 44 is folded inwardly, so as to overlie and be in parallelism with flaps 42 and 50. Lastly, flap 58 is folded so as to overlie and be in parallelism with flap 44. The reader will observe that the folding of flaps 58 causes a corresponding folding of flaps 40. The end closure flaps are held closed by any conventional adhesive applications. The container/package is now complete, as indicated at FIG. 4, and is ready for shipment and distribution.
To open the container/package of this invention, the user grasps the lower portion of the container and also the side portions above the severable perforated lines 56, see FIG. 4. A pulling action results in the breakage or severance of the lines, with the result being illustrated at FIG. 5 of the drawings. The lower portion of the opened container of FIG. 5 is denoted generally by the numeral 80, while the upper portion is denoted by the numeral 82. Thus, the numeral 82 denotes a generally box-like lid which is integrally hinged along hinge line 21 to the upper edge of rear panel 22. Friction flaps 50 are the innermost flaps within lid 82.
As may be seen now by reference to FIGS. 6 and 7 of the drawings, the upper portion 36 of post-forming flap 40 is sandwiched, in the closed condition of the container, between a respective friction flap 50 and a respective innermost lid side flap 48. The space between a friction flap 50 and its corresponding side flap 48 is termed a gap space 51. Flap 54 defines outermost side flap of box-like lid 82. Edge 32 of central recess 30 extends above the upper edge of front panel 14. Thus, an L-shaped post 34, 36 is formed at each upper end of front panel 14. The front wall of the container of FIG. 5 may be considered as defined by two parallel sheets, an outermost sheet 14 and an innermost sheet 26.
Assuming a typical use for the container of this invention as a package filled with crayons, after one of the crayons is removed, the lid 82 can be reclosed, with post-forming portions 36 being sandwiched between respective friction flaps 50 and flaps 48. In order to facilitate the movement of the lower front portion of lid 82 past the upstanding post portions 36, the free edges of friction flaps 50 are curved as denoted by the numeral 52.
Post forming panel 26, with its L-shaped end posts 34, 36, adds to the rigidity of the front wall of the container, while the posts themselves cooperate with the lid in a manner above described. Another advantage enjoyed by the practice of this invention is the capability to accept end loading of the container contents, as illustrated at FIG. 3.
In the claims, the terms upper, lower, and side will refer to the upper, lower and side portions of the container and/or blank of this invention as shown at FIGS. 1, 4 and 5.
Generally speaking, the present invention is directed to a container of rectangular parallelepiped shape formed from a single blank of stiff, foldable and resilient material, such as paperboard. The container has front, rear, top, bottom and side walls, and severable perforated lines in the side walls extending from the upper portion of the rear wall to the front wall. The front wall is defined by two partially coextensive panels, the outermost panel having a severable perforated line extending thereacross and whose ends meet, respectively, one end of a severable perforated line on each side wall, a lid hinge line on the rear wall whose termini meet, respectively, the other end of one of the severable perforated lines on each side wall, whereby the portion of the container above the perforated lines and above the lid hinge line forms a box-like lid which can be hinged about the lid hinge line upon breaking the severable perforated lines. The innermost panel of the front wall includes post flap at each side thereof parallel to a respective side wall of the container and whose upper edge extends above the severable perforated lines on the container side walls. The top wall of the box-like lid has at each end thereof a downwardly extending friction flap and a gap space between each friction flap and its respective box-like lid side wall. Each post flap is sandwiched in its respective gap space, whereby when the box-like lid is formed it can be reopened and reclosed by being hinged along the lid hinge line, with the post flaps frictionally sandwiched in the gap spaces upon reclosing to thereby assist in properly aligning the box-like lid relative to the remainder of the container upon reclosure of the box-like lid and also to assist in maintaining the box-like lid in the reclosed position by virtue of such frictional engagement.
Although the invention has been described above by reference to a preferred embodiment, it will be appreciated that other carton constructions may be devised, which are, nevertheless, within the scope and spirit of the invention and are defined by the claims appended thereto. | A container in the shape of a rectangular parallelepiped. The front and side walls are provided with severable perforated lines. Upon rupture of the severable lines, a hinged, box-like lid is formed which is reclosable. The container front wall is associated with upstanding L-shaped posts at its upper edge. One surface of each L-shaped post frictionally fits into a respective gap space within the box-like lid, each gap space defined by parallel lid guide flaps carried by the sides of the box-like lid. The container is loaded from one end, with, for example, a plurality of crayons, and then closed to define a package. The container is formed from a single sheet of paperboard. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates in general to communication systems and subsystems therefor, and is particularly directed to a clock recovery scheme for a digital communication receiver. The clock recovery scheme employs a fixed fractional delay line that is driven by a fixed reference clock source, to provide a plurality of respectively offset phase delayed versions of the reference clock. One of the phase delayed versions of the reference clock is used as the recovered clock. A control loop steps through the outputs of the fixed fractional delay line, so as to controllably increase or decrease the effective frequency of the reference clock and thereby adjust the frequency of the recovered clock signal.
BACKGROUND OF THE INVENTION
[0002] In order to successfully coherently recover data from a received digital communication signal, digital communication receivers employ some form of clock recovery or extraction mechanism that operates on the received signal. A conventional variable frequency oscillator-based scheme employed for this purpose is diagrammatically illustrated in FIG. 1 as comprising a phase detector 10 , to which a received (RX) signal 11 and the output 13 of a variable frequency oscillator (VFO) 12 are applied. The output of the phase detector 10 , which represents the phase error between the received signal 11 and the output of the VFO is coupled through a loop filter 14 to the control input of the VFO 12 . The recovered clock corresponds to the output frequency of the VFO.
[0003] A shortcoming of this type of clock recovery scheme is the sensitivity and expense of the variable frequency oscillator, which is typically a crystal-based component, whose parameters may vary depending upon its manufacturer. In addition, where the receiver is employed in a relatively harsh environment, the oscillator is prone to substantial operational variation and degradation.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention, the above and other problems associated with using a variable frequency oscillator-based clock recovery circuit are effectively obviated by a clock recovery scheme that employs a fixed fractional delay line coupled to the output of a fixed frequency oscillator, the frequency of which is nominally that of the received signal. The delay line has a plurality of output ports from which respective incrementally delayed versions of the fixed clock frequency. Namely, the delay line produces N clock signals having successive delays (0/N)360, (1/N)360, . . . , ((N−1)/N)360 degrees relative to its input clock.
[0005] These N clock signals are respectively coupled to N input ports of a multiplexer, the output of which produces the recovered clock signal. The multiplexer output is further coupled to a phase detector/comparator of a feedback loop to which the received signal is applied. The output of the phase detector/comparator represents the error between the recovered clock and the received data signal, and is coupled through a loop filter and gain stage to a frequency accumulator. The gain is set so that the accumulator overflows when the difference frequency f d between the received data clock f R and frequency f N is a prescribed value, so that the output of the frequency accumulator indicates whether the recovered clock is running faster or slower than the clock embedded in the received data signal.
[0006] Where the output clock is running faster than the received signal, the state of the accumulator will cause the multiplexer to incrementally advance or step in a first, increased delay direction through the plurality of output ports of the delay line. This has the effect of lengthening a portion of one of the half-cycles of the output/recovered clock signal, thereby slowing down the recovered clock. On the other hand, where the output clock is running slower than the received signal, the state of the accumulator will cause the multiplexer to incrementally step through the output ports of the delay line in a reverse direction. This has the effect of shortening a portion of one of the half-cycles of the output/recovered clock signal, thereby speeding up the recovered clock.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 diagrammatically illustrates a conventional variable frequency oscillator-based clock recovery circuit for use with a digital communication receiver;
[0008] FIG. 2 diagrammatically illustrates an embodiment of the fixed fractional delay line-based clock recovery circuit of the present invention;
[0009] FIG. 3 is a timing diagram showing the effect of lengthening a portion of a clock cycle of the reference clock signal of the circuit of FIG. 2 , so as to slow down the recovered clock; and
[0010] FIG. 4 is a timing diagram showing the effect of shortening a portion of a clock cycle of the reference clock signal of the circuit of FIG. 2 , so as to speed up the recovered clock.
DETAILED DESCRIPTION
[0011] Before describing the fixed fractional delay line-based clock recovery circuit in accordance with the present invention, it should be observed that the invention resides primarily in a modular arrangement of conventional digital communication circuits and components. In a practical implementation that facilitates their being packaged in a hardware-efficient equipment configuration, these modular arrangements may be readily implemented as field programmable gate array (FPGA), or application specific integrated circuit (ASIC) chip sets.
[0012] Consequently, the configuration of such arrangements of circuits and components and the manner in which they are interfaced with other telecommunication equipment have, for the most part, been illustrated in the drawings by readily understandable block diagrams, and associated timing diagrams, which show only those specific details that are pertinent to the present invention, so as not to obscure the disclosure with details which will be readily apparent to those skilled in the art having the benefit of the description herein. The block diagram illustrations are primarily intended to show the major components of the clock recovery circuit of the invention in a convenient functional grouping, whereby the present invention may be more readily understood. For purposes of providing a non-limiting example, a receiver architecture in which the clock recovery circuit of the invention may be employed may comprise a baseband modem receiver for a wireline-powered digital radio, such as that disclosed in U.S. Pat. No. ______ to P. Nelson et al, assigned to the assignee of the present application and the disclosure of which is incorporated herein.
[0013] Attention is now directed to FIG. 2 , wherein an embodiment of the fixed fractional delay line-based clock recovery circuit of the present invention is diagrammatically illustrated as comprising a clock input port 21 , to which a fixed frequency input clock signal CLKI at some nominal frequency f N is applied. In the example of the radio disclosed in the above-referenced patent, the fixed frequency clock may be derived from the transmit clock employed in the transmit portion of the radio. Clock input port 21 is coupled to an input 31 of a fixed phase delay line 30 , which has a plurality of output ports 32 - 1 , 32 - 2 , 31 - 3 , . . . , 32 -N, from which respective incrementally delayed versions of the fixed clock frequency f N are produced. Namely, delay line 30 is operative to produce N clock signals having successive delays (0/N)360, (1/N)360, . . . , ((N−1)/N)360 degrees relative to the input clock supplied to the clock input port 21 .
[0014] These N clock signals are respectively coupled to N input ports 41 - 1 , 41 - 2 , 41 - 3 , . . . , 41 -N of a multiplexer 40 , an output port 42 of which produces the recovered or output clock signal CLKO. Output port 42 is further coupled to a phase detector/comparator 50 to which the received (RX) signal is applied. The output of the phase detector/comparator 50 , which represents the error between the recovered clock and the received data signal, is coupled through a loop filter 60 and gain stage 70 for application to a frequency accumulator 80 . The gain is set so that the accumulator 80 overflows when the difference frequency f d between the received data clock f R and frequency f N is a prescribed value. Namely, the output of the frequency accumulator 80 indicates whether the recovered clock is running faster or slower than the clock embedded in the received data signal.
[0015] Where the output clock CLKO is running faster than the received signal RX, the state of the overflow/underflow output 81 of the accumulator 80 will cause the multiplexer 30 to incrementally advance or step through the plurality of output ports 32 - 1 , 32 - 2 , . . . , 32 -N of the delay line 20 . As will be described below with reference to the timing diagram of FIG. 3 , this has the effect of lengthening one of the half-cycles of the output/recovered clock signal, thereby slowing down the recovered clock. On the other hand, where the output clock CLKO is running slower than the received signal RX, the state of overflow/underflow output 81 of the accumulator 80 will cause the multiplexer 30 to incrementally reverse through the plurality of output ports 32 - 1 , 32 - 2 , . . . , 32 -N of the delay line 20 . As will be described below with reference to the timing diagram of FIG. 4 , this has the effect of shortening one of the half-cycles of the output/recovered clock signal, thereby speeding up the recovered clock.
[0016] More particularly, FIG. 3 shows a set of three phase delayed versions of the fixed input clock signal CLKI as produced at output ports 32 - 1 , 32 - 2 , . . . , 32 -N of the fraction delay line 30 , where N=4. Since N=4, each successive version of the input clock signal is delayed by 90° relative to its immediately preceding version of the input clock signal. It will be assumed that the multiplexer is initially reset to couple its first input port 41 - 1 to its output port 42 , and that the output clock CLKO is running faster than the embedded clock in the received signal. It will also be assumed that the clock signal adjustment occurs once for every three successive clock cycles. Since multiplexer 40 ‘points’ to its input port 41 - 1 , then at time t0, the rising edge of the output clock CLKO coincides with the rising edge of the input clock version having the phase delay (0/N)360.
[0017] At time t1, the frequency accumulator 80 produces an output associated with an overflow condition. For this state of the accumulator output, multiplexer 40 responds by incrementing the connection of the output port 42 to the second input port 42 - 2 . Since, at time t1, the high state of the input clock version having the phase delay (1/N)360 is the same as that (high) as the input clock version having the phase delay (0/N)360, the state of the output clock is high and remains high for an additional period of time, to coincide with the clock version having phase delay ( 1 /N) 360 , which transitions low at time t2. Namely, due to the incrementing of the fixed phase delayed versions of the fixed input clock, the output clock has been lengthened or has slipped by a fraction (here 90°) of the clock cycle of the input clock.
[0018] With the clock signal adjustment occurring once for every three successive clock cycles, then at time t3 in the timing diagram of FIG. 3 , there is a further incremental advancing or stepping from the input clock version having the phase delay (1/N)360 to the next input clock version, namely input clock version having the phase delay (2/N)360. As shown therein, at time t3, the high state of the input clock version having the phase delay (2/N)360 is again the same as that (high) as the input clock version having the phase delay (1/N)360, so that the state of the output clock is high and remains high for an additional period of time, to coincide with the clock version having phase delay (2/N)360, which transitions low at time t4. Thus, due to the further incrementing of the fixed phase delayed versions of the fixed input clock, the output clock CLKO is again lengthened or slipped by a 90° fraction of the clock cycle of the input clock. It will be appreciated that for the example shown in the timing diagram of FIG. 3 , such slipping or lengthening of the output clock effectively reduces the frequency of the output clock CLKO to 12/13 of its original frequency.
[0019] The timing diagram of FIG. 4 shows the same set of three phase delayed versions of the fixed input clock signal CLKI as produced at output ports 32 - 1 , 32 - 2 , . . . , 32 -N of the fraction delay line 30 , again with N=4. It will be assumed that the multiplexer 40 is initially pointing to input port 41 - 3 , so that at time t0, the rising edge of the output clock CLKO coincides with the rising edge of the input clock version having the phase delay ( 2 /N) 360 .
[0020] At time t1, the frequency accumulator 80 produces an output associated with an underflow condition. For this state of the accumulator output, multiplexer 40 responds by decrementing the connection of the output port 42 to the second input port 42 - 2 . Since, at time t1, the high state of the input clock version having the phase delay (1/N)360 is the same as that (high) as the input clock version having the phase delay (2/N)360, the state of the output clock is initially high, but then transitions low at time t2, to coincide with falling edge of the clock version having phase delay (1/N)360, which transitions low at time t2. Namely, due to the decrementing of the fixed phase delayed versions of the fixed input clock, the output clock has been shortened or advanced by a fraction (here 90°) of the clock cycle of the input clock.
[0021] With the clock signal adjustment occurring once for every three successive clock cycles, then at time t3 in the timing diagram of FIG. 3 , there is a further decrementing from the input clock version having the phase delay (1/N)360 to the input clock version having the phase delay (0/N)360. Namely, due to the further decrementing of the fixed phase delayed versions of the fixed input clock, the output clock has been shortened or advanced by a fraction (here 90°) of the clock cycle of the input clock. For the example shown in the timing diagram of FIG. 4 , advancing the output clock effectively increases the frequency of the output clock CLKO to 12/11 of its original frequency.
[0022] As will be appreciated from the foregoing description, problems associated with using a variable frequency oscillator-based, clock recovery circuit are effectively obviated by the fixed fractional delay line-based clock recovery scheme of the present invention. Where the output clock is running faster than the received signal, the state of the accumulator will cause the multiplexer to incrementally advance or step through the plurality of output ports of the delay line in a first increased delay direction, which effectively lengthens a portion of a half-cycle of the output/recovered clock signal, thereby slowing down the recovered clock. Where the output clock is running slower than the received signal, the state of the accumulator will cause the multiplexer to incrementally reverse through the output ports of the delay line, in a decreasing delay direction, which has the effect of shortening a portion of a half-cycle of the recovered clock signal, thereby speeding up the recovered clock.
[0023] While we have shown and described an embodiment in accordance with the present invention, it is to be understood that the same is not limited thereto but is susceptible to numerous changes and modifications as known to a person skilled in the art, and we therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are obvious to one of ordinary skill in the art. | A clock recovery scheme for a digital communication receiver has a fixed fractional delay line that is driven by a fixed frequency reference clock source, to provide a plurality of respectively offset phase delayed versions of the reference clock. A phase lock loop, to which the received signal is coupled, controllably steps through the phase delayed versions of the reference clock, so as to controllably increase or decrease the effective frequency of the reference clock and thereby produce a recovered clock signal. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to throttling devices used as part of a pipeline or installed in other parts of fluid systems, in order to reduce high static pressure of a liquid or gas without the undesirable by-products of a high aerodynamic noise level in case of a compressible fluid such as natural gas coming from a high pressure gas well, or cavitation and erosion in case of a liquid. A typical liquid pressure reducing application would be boiler feed-water by-passing a feed-water pump under low load conditions, in order to keep the pump from being damaged. In applications like this, pressures as high as 6000 psi have to be reduced without the above mentioned adverse side effects.
Conventional devices employed for these purposes include perforated plates such as shown in U.S. Pat. No. 3,665,965, which generally perform satisfactorily. However, plates of this kind are very expensive to produce because all of the hundreds or sometimes thousands of small holes have to be drilled, a very time consuming effort. Stampings cannot be used because the thickness of the plates has to be more than two times a hole diameter, in order to withstand the stress in the metal caused by the hydrostatic pressure acting on the plate. Furthermore, undesirable resonance phenomena can occur with gaseous fluids, if the plate thickness is less than one hole diameter.
My invention overcomes these difficulties by use of stamped plates requiring essentially no machining and providing sufficiently large openings to accommodate the requirements set by the stamping die in relation to the plate thickness. Yet, the throttling flow passages can be kept small and narrow to ensure high energy losses or, in case of gases, high frequency of the produced aerodynamic noise (high frequency noise is better attenuated by surrounding pipe walls, i.e. produce less observable soundpressure levels outside of a piped fluid system). Any desired narrowness of the throttling flow passages of my invention can simply be determined by the selection of additional simple ring members or washers, which separate the stamped teeth-like configuration which provide vertical passage ways for the fluid.
Other objectives are to provide a compact fluid resistance device, which can be installed in existing piping systems by being clamped between a pair of line flanges and one whose fluid passages can easily be cleaned after being made accessible by a simple separation of a male and female member.
Yet, another objective is the provision of a fluid resistance device which has a relatively high flow capacity, yet offers maximum resistance. Such high flow capacity is possible with my teeth-like stampings, which provide up to 50% of the stamped annular surface area as vertical passage ways.
These and other objectives, features, and advantages of my invention will be readily apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a vertical, sectional view of one preferred embodiment of my invention as part of a fluid system and having gradually expanding flow passages.
FIG. 2 is a partial development of a vertical sectional view taken around a circle described by radius r in FIG. 1.
FIG. 3 is a horizontal sectional view of the preferred embodiment of my invention, as shown in FIG. 1.
FIG. 4 is a vertical, sectional view of another preferred embodiment of my invention having flow passages with constant cross-sectional areas and being shown as part of a fluid system.
FIG. 5 is a partial development of a vertical, sectional view taken around a circle described by radius r in FIG. 4.
FIG. 6 is a horizontal, sectional view of the preferred embodiment of my invention as shown in FIG. 4.
FIG. 7 is a partial development of a vertical, sectional view similar to FIG. 5, with progressively increasing separation of successive layers of baffles hence, gradual increasing flow areas.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, which shows a preferred form of my invention suitable for throttling of high pressure fluids of gaseous nature comprising a female member having a cylindrical opening and formed by a number of ringshaped horizontal plates, being retained within a housing 2 and separated from each other by spacer rings 4 forming therebetween circular channels 9. Each of the ringshaped plates 1 has teeth-shaped baffles 5 alternating evenly around the inner diameter with identically shaped, equal width and depth recesses 7, as more clearly shown in FIG. 3.
As illustrated by FIG. 2, each ringshaped plate 1 is angularly off-set by the width of a tooth from the adjacent plate or plates, with the off-setting of the successive plates being alternately in one and the opposite angular direction, thereby defining reversing or tortuous fluid paths 7, 9, and therein a series of rectangular restrictions 8 on either side of recesses 7, whose area is the product of the depth L of each recess 7 along the portion thereof not covered or overlapped by spacer ring 4 and, in the vertical direction, by the height of spacer ring 4. As can be seen, the cross-sectional area of each rectangular restriction 8 can be varied by either a change in the height of spacer ring 4 or a change in the inside diameter of the same, thereby deepening the circular channels 9, which in cooperation with the flanks 5a of the teeth 5 form the rectangular restrictions 8, wherein one flank 5a of one baffle or tooth of one plate or layer is seen to vertically overlie the opposite flank 5a of the offset tooth of the next baffle layer. A cylindrical male insert 10 is slidingly engaged within the cylindrical opening 11 of plates 1, thereby blocking a fluid entering an inlet section 12, formed by the upper horizontal layer of plates 1 and the inner wall of flange 13, the latter being part of a fluid system, from by-passing said restrictions 8 in its generally vertical travel along the fluid path or paths between the female member and male insert towards an outlet section 14 formed by the lower horizontal layer of plates 1 or spacer rings 4 and the enclosing wall of flange 15 (also being part of a fluid system). Accordingly, the generally vertical fluid path extending along the cylindrical interface of said female member and male insert between said inlet and outlet sections is a continuous, tortuous one wherein the fluid passing therethrough is made to undergo repeated, reversing, vertical-to-horizontal turns from said recesses 7 into said rectangular restrictions 8.
A shoulder 16 of insert 10 engages with one of the plates 1 aided by screw 17, which clamps a washer 18 against the lowest of plates 1. A pin 19 penetrates and connects each layer of plates 1 and spacer rings 4, in order to maintain the off-set teeth arrangement. Finally, tie-rods 20 and nuts 21 retain housing 2 between flanges 13 and 15, while a pair of gaskets 23 prevents external leakage of the fluid. Fluid entering through inlet section 12 passes through the recesses 7 of the first plate 1, divides or separates at the second plate baffles 5 underlying said first plate recesses 7, makes vertical-to-horizontal turns oppositely into and is accelerated by the first set of rectangular restrictions 8, and expands into a cavity formed by circular channel 9a, thereby losing some of its static pressure and, in the case of compressible fluids, expanding its volume. Upon emerging from said channel 9a the fluid recombines, with additional energy loss, upon passing or turning into the next set of restrictions 8. The following cavity 9b is enlarged in comparison to accommodate the aforementioned expansion in volume. This successive throttling process is repeated several times, until the fluid is allowed to exit through the last of plates 1 and escapes into the outlet section 14.
FIG. 4 shows another embodiment of my invention, more adapted to fluids with generally constant volume. Another difference in the form of construction lies in the fact that all teeth-like baffles 5 and fluid conducting recesses 7, described previously, are now part of the male insert instead of the female ringshaped counter part, as in FIG. 1. The male insert 24 here consists of a number of plates 25 having equally spaced tooth-like baffles 5 and recesses 7 at their outer periphery and being separated from each other by circular washers 26 of which the outer diameter forms a bottom for circular channels, which determine the size of rectangular restrictions 8, as previously described. Incidentally, a gradual increase in the area of restrictions 8, as demanded for compressible fluids, is also possible by gradually increasing the thickness of successive layers of washers 26, as shown in FIG. 7, thereby progressively increasing the height of restrictions 8a to 8e and hence the size or area of the respective rectangular throttling restriction or orifice. Additional supporting rings 27 may be placed around the outer periphery of plates 25, in order to support and keep baffles 5 from bending under high pressure loading. The inner diameter of these supporting rings now form the cylindrical opening for the flow channels conducting fluid flow in generally vertical directions. The complete assembly of male insert 24 is suitably fastened together by a rivet 28 and thereafter slidingly engaged within the cylindrical opening of a housing 29, preferredly machined from steel pipe, abutting a shoulder 30. A commercially available retaining ring 31 made from spring tempered steel, which fits snugly in a groove, cut into housing 29, finally retaines the assembly of male insert 24. Housing 29 and male insert 24 are part of a fluid system and are contained with a pair of flanges 32 held together by suitable tie-rods 20 and nuts 21, as previously described.
The preferred embodiments of my invention are shown to be made from stampings and where the tooth-like baffles and recesses have trapezoidal shape and are equal in size.
However, it should be understood that my invention is not limited to that particular configuration. For example, circular channels 9 and recesses 7 may be precision cast into a single cast piece constituting, for example, the cylindrical male insert assembly 24 or the ringshaped combination of plates 1, housing 2 and spacer rings 4. Similarly, recesses 7 might be shaped rectangularly or semi-circular without departing from the scope of the following claims. | A fluid resistance device being part of a fluid system and having high resistance, fluid energy absorbing passages along the interface between a ringtype member and a cylindrical male insert, and wherein said passages consist of a number of teeth-like baffles which are off-set from each other and which are separated from each other by circular grooves providing nearly rectangular throttling restrictions in series for the fluid passing generally along the longitudinal axis of the male insert. | 8 |
This application is a divisional of application Ser. No. 08/067,676, filed May 26, 1993, now U.S. Pat. No. 5,473,397.
BACKGROUND OF THE INVENTION
This invention relates to a camera having an internal data imprinting device. More particularly, the invention involves a camera capable of taking pictures in both a full size format and a panorama size format wherein each format has a distinct data size and data position upon a film.
Embodiments of cameras having data imprinting devices have employed fixed position systems wherein a size of a data image remained constant regardless of a format mode selected. In such systems the light path is fixed, for example, at a lower part of the film with the characters being imprinted in a center of a frame. Since the position of the data remained constant, data could not be imprinted within a framed area of a panorama size format picture.
Another embodiment of a camera with a data imprinting device, as disclosed in Japanese Laid-open Patent Publication No. 63-27823, employs an optical system having movable elements. The data imprinting device disclosed in this publication comprises a plurality of optical elements capable of moving to appropriate positions dependent upon a selected format. A first optical element is disposed at a first position in order to produce characters having full size format dimensions. A second optical element, preferably with a different enlargement, moves from a first position to a second position in order to imprint panorama size format data images which are smaller than those of the full size format. Thus, the two optical elements provide appropriate character sizes respectively. However, movement of the first and second optical elements necessitates increased system complexity and is prone to produce blurred data images due to inaccuracies in the positioning of the optical elements.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to provide a camera equipped with a data imprinting devices which overcomes the drawbacks of the prior art.
It is a general object of the present invention to provide a data imprinting device for imprinting data images at a first position in a full size format, and imprinting smaller data images at a second position in a panorama size format.
It is a further object of the present invention to provide a device permitting the imprinting of data upon a film in a full size and a panorama size format wherein fixed optical components are solely employed.
Still further, it is an object of the invention to provide a device for imprinting data upon a film which permits a width of a camera to be minimized.
Yet another object of the present invention is to provide a data imprinting device, for use in a camera, which permits the depth of a camera to be minimized.
Briefly stated, the present invention provides a camera with a data imprinting device having a plurality of in-line LEDs producing light focused by an optical system upon a photographic film at a first and a second position, corresponding to a full size format and a panorama size format, respectively. The focused light imprints data images upon the film at the first position which are larger than data images imprinted at the second position. The optical system has first and second prisms, with integrated lenses, for reflecting and focusing the light upon the film at the first and second positions, respectively. A shutter plate is selectively positioned over apertures through which the light is focused, thus blocking the light and allowing only a selected imprint to be made upon the film. A vertical pattern of the data image is created by a controller selectively illuminating the in-line LEDs while a horizontal pattern is produced by the controller illuminating the LEDs in coordination with the movement of the film past the apertures. The controller actuates a motor for advancing the film and has a sensor for detecting film travel. A first embodiment has the first prism positioned further from the film than the second prism, which is positioned further from the LEDs than the first prism, such that reflected light from the first prism has a path intersecting that of incident light of the second prism. A second embodiment has the prisms offset from each other in the plane of the film such that light paths do not intersect. The first embodiment has a narrower width than the second embodiment while the second embodiment has a shallower depth than the first embodiment.
According to an embodiment of the invention, there is provided a camera comprising: a camera body, light emitting elements, optical means for focussing light emitted from the plurality of light emitting elements on a surface of a photosensitive means, means for selecting at least one of a first screen size and a second screen size, the optical means having optical elements for creating first and second images corresponding to each screen size, means for occluding the light focussed by the optical means, the means for occluding being responsive to the means for selecting, means for forming imprinted data from the light focussed on the surface of the photosensitive means, and means for exposing the surface of the photosensitive means to light from an object to be photographed.
Furthermore, according to an embodiment of the present invention, there is provided a data imprinting device for use in a camera comprising: illumination means for emitting imprinting light, optical means for focusing the imprinting light upon a photosensitive surface at at least two positions, means for selectively blocking the imprinting light from focusing upon at least one position of the at least two positions, and control means for coordinating the illumination means with a movement of the photosensitive surface such that the imprinting light produces images upon the photosensitive surface.
According to a feature of an embodiment of the present invention there is provided an optical means for focussing including crossing light paths permitting the optical elements to be in-line in a plane perpendicular to the surface.
Still further, an embodiment of the present invention provides a data imprinting device for use in a camera comprising: illumination means for emitting imprinting light, optical means for focusing the imprinting light upon a photosensitive surface at at least two positions, the optical means including a first reflecting means for reflecting incident light of the imprinting light upon a first position of the at least two positions, the optical means including a second reflecting means for reflecting incident light of the imprinting light upon a second position of the at least two positions, the first position being above the second position, the first reflecting means being set back further from the photosensitive surface than the second reflecting means, means for selectively blocking the imprinting light from focusing upon at least one position of the at least two positions, control means for coordinating the illumination means with a movement of the photosensitive surface, and framing means for selectively shielding an upper and a lower portion of the photosensitive surface from subject image light in coordination with the means for selectively blocking.
Another feature of the present invention provides a device for imprinting data wherein the control means comprises: sensing means for detecting travel of the photosensitive surface past a point of imprinting, advance means for advancing the photosensitive surface, a controller responsive to the sensing means, the controller actuating the advance means, and the controller selectively illuminating the illumination means in response to the sensing means.
Yet another feature of the present invention provides for a data imprinting device wherein the framing means comprises: an upper framing member, pivotally mounted, having a framing portion extending laterally across an upper portion of the photosensitive surface such that the subject image light is selectively obstructed by the framing portion, a lower framing member, pivotally mounted, having a framing portion extending laterally across a lower portion of the photosensitive surface such that the subject image light is selectively obstructed by the framing portion, and the upper and lower framing member having geared portions mutually engaged such that the upper and lower framing members pivot in complementary directions.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross section of a camera showing a first embodiment of the invention as viewed from the top.
FIG. 2 is a perspective view of a rear portion of a camera body according to the embodiment of the invention in FIG. 1.
FIG. 3 is a transverse cross section of the camera of FIG. 1, as viewed from the side, depicting an optical system and a cutaway view of a framing mechanism operating in a full size mode position with double dashed outlines illustrating a panorama size mode position.
FIG. 4 is a rear view of the camera body of the first embodiment of the present invention, shown in FIG. 1, illustrating a shutter plate and the framing mechanism in full size format positions.
FIG. 5 is a view of a film imprinted upon by the present invention showing a panorama size format overlaid upon a full size format.
FIG. 6 is a transverse cross section of the camera of FIG. 1, as viewed from the side, depicting the optical system and a cutaway view of the framing mechanism operating in a panorama size mode.
FIG. 7 is a rear view of the camera body of the first embodiment of the present invention in FIG. 1 illustrating positions of the shutter plate and the framing mechanism in a panorama size mode.
FIGS. 8a and 8b are schematic diagrams showing optical paths in the first embodiment in full and panorama size modes, respectively.
FIG. 9 is a transverse cross section of a camera of a second embodiment of the present invention, as viewed from the side, depicting an optical system and a cutaway view of a framing mechanism operating in a full size mode position with double dashed outlines illustrating a panorama size mode position.
FIG. 10 is a rear view of the camera body of the second embodiment of the present invention, shown in FIG. 9, illustrating positions the shutter plate and the framing mechanism in the full size format position and light paths of the optical system.
FIGS. 11a and 11b are schematic diagrams showing the optical paths in the second embodiment of the present invention in full size and panorama size modes, respectively.
FIG. 12 is a transverse cross section of a camera of a third embodiment of the present invention, as viewed from the side, depicting an optical system and a shutter plate configuration.
FIG. 13 is a rear view of the camera body of the third embodiment of the present invention, shown in FIG. 12, illustrating the shutter plate and the framing mechanism in the full size format position.
FIG. 14 is a transverse cross section of the third embodiment of the present invention, as viewed from the side, depicting the optical system and a cutaway view of the framing mechanism operating in the panorama size mode.
FIG. 15 is a rear view of the camera body of the third embodiment of the present invention illustrating positions of the shutter plate and the framing mechanism in the panorama size mode.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown a first embodiment of the present invention having a camera body 1 with a dark chamber 2 integrally formed therein. Light, from an object to be photographed (not shown), is focused by a photographic lens L, through dark chamber 2, onto a surface of a film F when a shutter 52 is opened. An aperture 1c, in a back surface 1b of camera body 1, allows the light to strike a photosensitive surface of film F. Film F is drawn across aperture 1c into a take-up spool chamber 3A by a take-up spool 11, from a feed spool chamber 3B. The feed spool chamber 3B and take-up spool chamber 3A are both integrally formed within camera body 1. A partitioning wall la separates take-up spool chamber 3A from dark chamber 2.
Referring to FIG. 2, aperture 1c is flanked, on upper and lower sides, by inner rails 4a and 4b, respectively. Inner rails 4a and 4b protrude into dark chamber 2 from back surface 1b of camera body 1. A pair of outer rails, 5a and 5b, are disposed outside inner rails, 4a and 4b, and protrude from back surface 1b further into dark chamber 2 than inner rails 4a and 4b. Outer rails, 5a and 5b, guide film F (not shown) as it is drawn across aperture 1c. A first pressing roller 12 is biased toward take-up spool 11 by a leaf spring 12a affixed to partitioning wall 1a. A boss 11a, disposed on take-up spool 11, engages a sprocket perforation in film F (not shown) and winds film F around take-up spool 11 as take-up spool 11 is rotated in a counterclockwise direction.
Referring back to FIG. 1, a back cover 6 encloses a rear of camera body 1, and a front cover 7 encloses a front of camera body 1. A pressure plate 8, disposed on an inside surface of back cover 6, biases film F into contact with inner rails 4a and 4b shown in FIG. 2. A second pressing roller 13 is biased toward take-up spool 11 by a leaf spring 13a affixed to back cover 6. Pressure imposed by first and second pressing rollers, 12 and 13, upon film F ensures tight winding of film F on take-up spool 11.
A circle Cmax, shown by a double dash line, indicates the maximum diameter of film F wound on take-up spool 11. When the diameter of film F is at or near maximum circle Cmax, roller 12 is urged into a position, shown by a two-dots-dash line into a recess 3a in partitioning wall 1a. Roller 13 is similarly urged outward to a position shown by a two-dots-dash line.
Referring again to FIG. 2, a data imprinting device includes a plurality of light emitting elements 21, preferably light emitting diodes (LEDs), disposed in a line on a substrate 22 in a direction perpendicular to the photosensitive surface of film F. Substrate 22 is mounted on a top surface 1d of camera body 1 such that emitted light from light emitting elements 21 passes through an aperture 1e in top surface 1d of camera body 1. A driver circuit (not illustrated), for light emitting elements 21, is also disposed on substrate 22.
An optical system including first and second prisms 23 and 29, is disposed in a substantially triangular space S (indicated in FIG. 1) defined by back surface 1b of camera body 1. The prisms, 23 and 29 reflect the emitted light 90 degrees such that reflected light passes through apertures 1f and 1g, respectively, thereby imprinting data upon the photosensitive surface of film F (not shown). A shutter plate 36, having an aperture 36b, is disposed at a rear side of camera body 1. The shutter plate 36 is shown in a first position, used for a full size exposure, wherein aperture 1f is unobstructed, permitting the emitted light to pass therethrough and expose film F (not shown) while aperture 1g is obstructed. Alternatively, shutter plate 36 may be moved upward into a second position such that aperture 1f is obstructed and aperture 1g is aligned with aperture 36b, permitting the emitted light to pass therethrough and expose film F. The second position allows imprinting of film F in a panorama size format.
Referring to FIG. 3, a mechanism for the operation of shutter plate 36 includes an upper screen framing member 31 attached to shafts 32, 32. Shafts 32, 32, pass rotatably through partitioning walls 1a and 1k, as shown in FIG. 1, allowing upper screen framing member 31 to rotate through an angle. A screen frame actuator 33 has a slot engaging a pin 31b on an ear portion 31a of upper screen framing member 31. An external control (not shown) is used to displace screen frame actuator 33 from a full size frame position to a panorama size frame position, shown by a double dash outline in FIG. 3, thereby rotating upper screen framing member 31 from a full size frame position, shown by the solid outline, to a panorama size frame position, shown by the double dash outline. In the full size frame position, upper screen framing member 31 has a cropping portion 31', shown in FIG. 1, which is raised thereby permitting exposure of an upper portion of film F. In the panorama size format position, cropping portion 31' is lowered thereby masking the upper portion of film F.
A lower screen framing member 34 is similarly mounted upon shafts 35, 35, which pass rotatably through walls 1a and 1k, as shown in FIG. 1. Lower screen framing member 34 has a geared portion 34c engaged with a geared portion 31c of upper screen framing member 31 such that motion of lower screen framing member 34 mirrors that of upper screen framing member 31, thereby cropping the lower portion of film F with a cropping portion 34' shown in FIG. 1.
The shutter plate 36 has an ear portion 36c with a slot 36a therein. A boss 34a, of lower framing member 34, engages slot 36a. Shutter plate 36 is slidably mounted such that it is actuated along a vertical axis in accordance with a position of lower framing member 34. Shutter plate 36 is shown in the full size position, covering aperture 1g while aperture 1f is uncovered. Alternative methods of implementing a shutter mechanism would be recognized in view of this disclosure by those skilled in the art. For example, pivoting shutters and rod-type linkages may be employed. Such methods, while employing alternative actuating systems, remain within the scope and spirit of the present invention.
An optical system comprises an optical system shaft 24 which has an upper taper 24a and a lower taper 24b supporting prisms 23 and 29, respectively. Upper taper 24a is set back further from the surface of film F than lower taper 24b thereby permitting emitted light from light emitting elements 21 to reach both lower taper 24b and upper taper 24a. Prisms 23 and 29 both have reflecting surfaces on planes of upper and lower tapers, 24a and 24b, respectively, for reflecting the emitted light onto the surface of film F. Reflected emitted light of prism 23 crosses a path of incident emitted light of prism 29. The crossing of light paths permits both prisms, 23 and 29, and their respective apertures, 1f and 1g, to be in a line in a plane perpendicular to film F, thus allowing the optical system shaft width to be narrow along an axis perpendicular to the plane of FIG. 3.
A roller 25 contacts an inner surface of film F and a spring 26, aligned with roller 25, contacts an outer surface of film F biasing film F against roller 25. Friction between roller 25 and the surface of film F rotates roller 25 in step with the movement of film F. Roller 25 is coupled to a slit wheel 27 by a shaft 25a. A conventional photo interrupter 28 encircles the edge of slit wheel 27. Photo interrupter 28 includes a light source in one of its arms and a photo detector in another of its arms. Each time a slit in slit wheel 27 passes between the light source and the photo detector, the photo detector produces a pulse signal which indicates a length of film F passing roller 25. It would be realized by one skilled in the art that alternative means of tracking film advance exist such as magnetic hall effect devices and variable resistance devices. Use of such devices is within the scope and spirit of the present invention.
The pulse signal from photo interrupter 28 is applied as a feedback signal to a controller 40. Controller 40 comprises a CPU, ROM, RAM and peripherals for controlling a motor driver 41 for driving a film advance drive motor 42. An exposure format detecting switch 43 is controlled by a position of screen frame actuator 33 and signals to controller 40 a selected exposure format. The exposure format detecting switch has a brush 43a, positioned by screen frame actuator 33, which engages a stationary portion 43b. Signals produced by controller 40 are applied to LED driver 44. LED driver 44 produces drive signals for the LEDs of light emitting elements 21. The timing of the drive signals applied to light emitting elements 21 is controlled according to whether full size or panorama size format mode is selected. It is recognized that embodiments of the present invention may employ other means for implementing the controller without departing from the scope and spirit of the present invention.
Contact between brush 43a and stationary portion 43b produces an electrical signal which indicates to controller 40 that the panorama size format is selected. When the panorama size format is selected, controller 40 actuates LED driver circuit 44 such that positioning and timing of the imprinting of data produces imprinted data in the panorama format. Conversely, when brush 43a and stationary portion 43b are out of contact, controller 40 initiates imprinting corresponding to that required in full size mode.
Referring to FIG. 4, a backside view of the camera shows shutter plate 36 positioned in the full size format position with aperture 1f open and aperture 1g occluded. Upper and lower screen framing members, 31 and 34, are adjacent to shutter plate 36 and its ear portion 36c. Roller 25 is shown disposed below inner rail 4b and shutter plate 36. Film F, shown cut-away to the right, is aligned so as to pass over roller 25 which signals to controller 40 the amount of film passing. When the panorama size format is selected, shutter plate 36 rises upward and aperture 36b is aligned with aperture 1g. Thus, reflected light passing through either one of aperture 1f and aperture 1g is used to imprint data upon film F as it travels. The travel of film F, as sensed by roller 25, is used to coordinate a sequentially implemented longitudinal imprinting pattern upon film F. A vertical imprinting pattern is determined by a selection of LEDs of light emitting elements 21, as depicted in FIG. 3, which are simultaneously illuminated. Alternative embodiments of the present invention may employ differing light emitting devices or light controlling devices without departing from the scope and spirit of the present invention.
Referring to FIG. 5, format layouts are shown with the panorama size format cropping shown in double dash lines superimposed upon the full size format cropping. Imprinted data 101 is in a position used in the full size format and imprinted data 102 is in a position used in the panorama sized format. The vertical positioning of imprinted data, 101 and 102, is determined by the positioning of apertures 1f and 1g, respectively. Imprinted data 102 of the panorama size format is accordingly located inward from imprinted data 101 of the full size format. A pattern of imprinted data, 101 and 102, as noted above, is produced by selective sequential illumination of the LEDs of light emitting elements 21 in coordination with the travel of film F past apertures 1f and 1g. Imprinted data, 101 and 102, of the figure may represent, for example, the date of the exposure. It is recognized that various other types of information and data may be imprinted upon the exposure. As examples and not limitations, such data may include an f-stop setting, a shutter speed setting, light levels, and photo identifiers or titles. It is further recognized that embodiments of the present invention may include peripherals that interface with the camera to allow data to be entered for imprinting purposes.
Referring to FIG. 6, the optical system and the mechanism for the operation of the shutter plate 36 is shown in the panorama size format mode. The incident emitted light of prism 29 crosses the path of the reflected emitted light of prism 23 and is reflected by prism 29 upon the surface of film F. Aperture 36b, of shutter plate 36, is place in alignment with aperture 1g of the optical system, permitting the emitted light to strike film F at a lower position than in the full size framing position, wherein the reflected emitted light passes through aperture 1f. Shutter plate 36 covers aperture 1f of the optical system thereby disabling full size format data imprinting.
Referring to FIG. 7, the alignment of shutter plate aperture 36b with the optical system aperture 1g is shown from the rear side perspective. Cropping portions, 31' and 34', of upper and lower framing members, 31 and 34, respectively, are shown in their panorama mode positions, and aperture 1f is covered by shutter plate 36 thus disabling the imprinting of data in the full size format.
Referring to FIGS. 8(a) and 8(b), the optical relationships of prisms 23 and 29 are shown wherein a size of the imprinted data is varied from the full size format to the panorama size format. While prisms 23 and 29 in prior figures have a reflecting surface, biconvex lenses, and are triangular in shape, prisms 23 and 29 are represented in FIG. 8 as simple biconvex lenses in the interest of simplicity. An arrow Y0 at the left of FIGS. 8(a) and 8(b) represents an object height of light emitting elements 21 while arrows, Y1 and Y2, on the right side represent image heights of the resultant imprinted data. While object height Y0 is constant in both figures 8(a) and 8(b), image height Y1 of the full size format imprinted data is larger than image height Y2 of the panorama size format imprinted data, shown in FIG. 8(a). The ratio of object and image distances, S 1 to S 1 ', is determined by a position of prism 23 in optical shaft 24 with respect to light emitting elements 21 and the surface of film F. The focal length f of the lens may then be selected to produce a focused image based upon this ratio. Similarly, the ratio of object and image distances, S 2 to S 2 ' is determined. It is realized that alternative embodiments of the present invention may employ other light directing and focusing means, such as mirrored surfaces and independent lenses, in place of the compound lens-prism of the presented embodiment, without departing from the scope and spirit of the present invention.
The embodiment of the present invention, as described above, has prism 23 in a line with prism 29 in a vertical plane perpendicular to the surface of film F and set back further from film F than prism 29, as shown in FIG. 6. This arrangement results in image distance S 1 ' being greater than image distance S 2 ' and the crossing of paths of the reflected emitted light of prism 23 and the incident emitted light of prism 29. Furthermore, the selection of the distances S 1 , S 2 , S 1 ', and S 2 ' permits the use of a single type of prism having the same focal length f for both prisms 23 and 29. Finally, the crossing paths of light permits the in-line arrangement thus reducing the width of the space required for the optical system allowing a more compact camera to be produced.
Referring to FIGS. 9 and 10, a second embodiment of the present invention is shown having features similar to those of the first embodiment, described above, except as note herein. An optical system shaft 124 has upper and lower tapers, 124a and 124b, upon which are mounted prisms 123 and 129, respectively. Prisms, 124a and 124b, are located a substantially equal distance from the surface of film F and are thus in a line with each other in a plane parallel with film F. In FIG. 10, it is clear that prisms, 123 and 129, are offset from each other. This offset arrangement produces an optical system requiring less depth in camera body 1 than the first embodiment of the present invention since there is no crossing of light paths.
Referring to FIG. 11, wherein optical path lengths of the second embodiment of the present invention include image distances S 11 ' and S 12 ', representing distances from film F to prisms 123 and 129 respectively, being substantially equal. Object distances S 11 and S 12 represent distances from light emitting elements 21 to prisms 123 and 129 which are represented as simple biconvex lenses for purposes of simplicity. Object distance S 11 is shorter than object distance S 12 . Accordingly, image height Y1 produced in the full size format is greater than image height Y2 produced in the panorama size format. Focal lengths f 1 and f 2 of prisms 123 and 129 are either selected independently in order to focus images Y1 and Y2, or are equal provided that there is a sufficient depth of field for images to be adequately focused. It is recognized by those skilled in the art that various combinations of focal lengths and object and image distances may be chosen based upon requirements of a system.
Referring to FIGS. 12 through 15, there is shown a third embodiment of the present invention which is similar to the first embodiment except as noted herein. A shading plate 136 is shown in a full size format position in FIGS. 12 and 13 wherein an upper portion of shading plate 136 covers aperture 1g and ends a distance H from aperture 1f. Shading plate 136 is in the panorama format position in FIGS. 14 and 15 with aperture 36b aligned with aperture 1g thereby permitting data imprinting in a panorama size format. Aperture 1f remains uncovered thus permitting simultaneous full size format data to be imprinted, however, the full size format data does not affect a photographed image because the full size format imprinting is on an area of film F which is masked by upper cropping portion 31' of upper framing member 31.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A camera with a data imprinting device has a plurality of in-line LEDs producing light focused by an optical system upon a photographic film at a first and a second position, corresponding to a full size format and a panorama size format, respectively. The focused light imprints data images upon the film at the first position are larger than data images imprinted at the second position. The optical system has first and second prisms, with integrated lenses, for reflecting and focusing the light upon the film at the first and second positions, respectively. A shutter plate is selectively positioned over apertures through which the light is focused, thus blocking the light and allowing only a selected imprint to be made upon the film. A vertical pattern of the data image is created by a controller selectively illuminating the in-line LEDs while a horizontal pattern is produced by the controller illuminating the LEDs in coordination with the movement of the film past the apertures. The controller actuates a motor for advancing the film and has a sensor for detecting film travel. A first embodiment has the first prism positioned further from the film than the second prism, which is positioned further from the LEDs than the first prism, such that reflected light from the first prism has a path intersecting that of incident light of the second prism. A second embodiment has the prisms offset from each other in the plane of the film such that light paths do not intersect. The first embodiment has a narrower width than the second embodiment while the second embodiment has a shallower depth than the first embodiment. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a long-lasting collagen and its manufacturing method, and more particularly to a method of producing a collagen by adding γ-polyglutarmic acid (γ-PGA) to the collagen and going through two crosslinking processes to obtain the long-lasting collagen. The invention not only increases the storage time of the collagen in human body, but also achieves a better biocompatibility and provides a higher value for practical applications.
[0003] 2. Description of Related Art
[0004] As we get older, our skin ages and loses its charm and healthy glow, causing wrinkles and tough inelastic skins, since the metabolic capability of dermis under the skin reduces with age, and the dermis is a main factor of the elasticity of skin. Reduction in the metabolic capability of skin will lead to skin aging, and thus various different rejuvenation methods are developed and available in the market. Among these rejuvenation methods, facial filler gives the best effect so far, and facial filler can be divided into two main types of materials: a synthetic material and a natural material. The synthetic material includes: silicone, hydroxyapatite (HAP), polylactic acid (PLA), polymethyl methacrylate (PMMA) and hydroxyethylmethacrylate (HEMA), etc. The natural material includes: botox (BT), autologous fat, collagen and hyaluronic acid (HA), etc.
[0005] However, the synthetic facial filler has the following drawbacks:
[0006] 1. Silicone exists permanently in human body after being injected into the human body and it will cause long term inflammation and granulomas, and thus the silicone must be removed by operation. In addition, silicon may migrate due to gravitational force, and thus U.S. Food and Drug Administration (FDA) prohibits applying silicon into human beings by laws.
[0007] 2. In a hydroxyapatite (HAP) material such as Radiesse, the only facial filler meeting the laws and regulations set forth by the U.S. Food and Drug Administration (FDA). Although HAP can be maintained for 2 to 5 years, nodule may occur sometime, particularly at the positions of mouth and lip, and it gives a bad look.
[0008] 3. Poly l-lactic acid (PLLA) is generally used as an injection material. Although PLLA has been approved by U.S. Food and Drug Administration (FDA), granulomas may still occur, and PLLA has the highest frequency of occurrence of granulomas among all facial fillers.
[0009] 4. Polymethyl methacrylate (PMMA) comes with an excellent biocompatibility, but it cannot be degraded in human body and becomes a bio-accumulative substance. Although PMMA is a permanent implantation material, granulomas also occurs easily, and thus many countries have banned the use of polymethyl methacrylate (PMMA) for hypodermic injection.
[0010] 5. Hydroxyethylmethacrylate (HEMA) has a drawback similar to that of the polymethyl methacrylate (PMMA), but it contains a hydroxyl radical (—OH), and thus its elasticity is enhanced after being applied. However, PMMA will be hardened as time goes by.
[0011] In summation, the shortcomings of the synthetic facial filler material reside on its causing serious inflammations and having major side effects on human bodies.
[0012] Further, the natural facial fillers also have the following drawbacks:
[0013] 1. Botox (BT) disables some of the biological functions of nerves and muscles by holding back the release of acetylcholine to achieve the effect of removing dynamic wrinkles, but botox (BT) also disables some of the biological functions of muscles, and the muscles will be degenerated after a period of time, and the facial expression of a patient will be unnatural when smiling. As the muscle activity is reduced, patients have to massage the injecting position everyday. In addition, researches reports show that there is 1% of fatal risk for an overdose of botox (BT).
[0014] 2. Autologous fat is made of a material coming from a patient's autologous fat, and thus the biocompatibility is very high, but the time for the autologous fat to be remained in human varies greatly due to the fat source and the individual difference of the patient, and the time varies from months to years. On the other hand, the autologous fat has larger particles that cannot fill wrinkles or small lines in a small area, and thus the effect and range are very limited.
[0015] 3. There are different collagens including human collagens, cadaveric collagens, bovine collagens and porcine collagens, etc, wherein the bovine collagen has been used for more than 20 years, and approved by the U.S. Food and Drug Administration (FDA). As mad cow disease existed in both animals and humans explodes and has the risk of infection. Although human collagen has passed the approval of the U.S. Food and Drug Administration (FDA), human collagen is not available easily, and its price is higher than other materials. The cadaveric collagen is also not available easily as the human collagen, and the particle size is larger than the human collagen falling within a range of micrometer (μm) and millimeter (mm) due to the factor of cultivation environment, and thus a thicker and larger needle is needed and it will cause additional pain to patients.
[0016] 4. Since hyaluronic acid (HA) is a polysaccharide composed of two monomers (such as N-acetyglucosamine and D-glucuronic acid) that can go through a complete metabolism, but the structure of the monomer (such as N-acetyglucosamine) is very close to heparin, such that if there is a wound, the monomer (N-acetyglucosamine) will be used for filling, and the quantity of hyaluronic acid (HA) will be reduced. Since hyaluronic acid (HA) can enhance the combination of matter under the dermis and cannot make the skin elastic, therefore it is necessary to avoid the wound from being pressed by external forces and further hurting the wound after the implantation. On the other hand, the movement of muscles accelerates the absorption of hyaluronic acid (HA), and thus patients have to avoid excessive facial expressions.
[0017] In summation of the foregoing materials of the natural and synthetic facial fillers, the level of inflammation caused by collagens is the lowest, and thus collagens can be used extensively, but they still have the following drawbacks:
[0018] 1. The time of collagens remained in human body is short, and uncrosslinked collagens will be degraded and absorbed in human body within three months, and collagens crosslinked by a crosslinking agent such as glutaraldehyde can remain a human body for six months, which is still too short, so that patients have to apply an injection for the supplement frequently, and it causes tremendous inconvenience.
[0019] 2. Collagens are biological poisonous, and the collagens crosslinked by glutaraldehyde have a high concentration of remained glutaraldehyde, which is biologically poisonous and harzardous to human health.
[0020] Obviously, the conventional collagens still have many drawbacks and require further improvements.
SUMMARY OF THE INVENTION
[0021] In view of the foregoing shortcomings of the conventional collagen with short storage time and biological poison, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally developed a long-lasting collagen and invented a manufacturing method of the collagen in accordance with the present invention to overcome the shortcomings of the prior art.
[0022] Therefore, it is a primary objective of the present invention to provide a long-lasting collagen, wherein a γ-polyglutarmic acid (γ-PGA) is added into a collagen and gone through a crosslinking process twice to obtain a long-lasting collagen with a uniformly and completely crosslink and a storage time increased by two to three times, so as to overcome the shortcomings of the conventional collagens having a short storage time and requiring an injection for suppment frequently.
[0023] Another objective of the present invention is to provide a low biologically poisonous collagen that uses glutaraldehyde of a very low concentration to uniformly and completely cross link the collagen with the glutaraldehyde to obtain remained glutaraldehyde of a very low concentration while providing a collagen with a better biocompatibility, so as to overcome the shortcomings of the conventional collagen having a high concentration of remained glutaraldehyde and a biologically poisonous glutaraldehyde that are harmful to our health.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention, as well as its many advantages, may be further understood by the following detailed description and drawings in which:
[0025] FIG. 1 is a flow chart of the present invention;
[0026] FIG. 2 is a schematic view of the chemical structure of γ-polyglutarmic acid (γ-PGA);
[0027] FIG. 3 is a curve of standard solutions of the collagen; and
[0028] FIG. 4 is a schematic view of test results of Group A, B and C samples with the same concentration in the degrading speed of a collagenase.
DETAILED DESCRIPTION OF THE INVENTION
[0029] To make it easier for our examiner to understand the technical measures and operating procedure of the invention, we use preferred embodiments together with the attached drawing for the detailed description of the invention.
[0030] The present invention discloses a long-lasting collagen and its manufacturing method, wherein a collagen is prepared, and a γ-polyglutarmic acid (γ-PGA) is added into the collagen, while going through a predetermined manufacturing process to obtain a long-lasting collagen. The chemical structure of γ-polyglutarmic acid (γ-PGA) is shown in FIG. 2 , and the amine linkage (—CONH) formed by linking an amino group (—NH 2 ) of the γ-polyglutarmic acid (γ-PGA) and a carbonyl group (—COOH) of a (residue group) which is called γ-linkage, and the linkage is relatively not easy to be degraded rapidly by the attack of an enzyme in human body, and the γ-polyglutarmic acid (γ-PGA) significantly resists the degrade of enemzes in human body to greatly retard the degrade of collagens in human body.
[0031] With reference to FIG. 1 , the long-lasting collagen is manufactured by the following procedure:
[0032] Step 1 : Scrape extra tissues: Firstly, scrape extra muscle and fat tissues, and cut the remaining portion into small segment tissues.
[0033] Step 2 : Remove grease: Dip the small segment tissues in acetone to remove grease, and rinse the small segment tissues twice until the grease is removed completely.
[0034] Step 3 : Imbibition: Dip the degreased small segment tissues in salt water (with a concentration is 1%) at a predetermined temperature (4° C.) for a predetermined time (24 hours), and then dip it in citric acid solution of a specific pH value (4.5) for the predetermined time for the imbibition of the small segment tissues.
[0035] Step 4 : Digestion: Dip the imbibited small segment tissues in a first solution (which is a mixed solution of pepsin and hydrochloric acid with a concentration of 0.5M) at the predetermined temperature for the predetermined time to digest the small segment tissues into a second solution.
[0036] Step 5 : Centrifugal Separation: Separate the digested small segment tissues from the second solution by performing a centrifugal separation of the second solution in a first predetermined condition (wherein the weight of the second solution is equal to 5500 g).
[0037] Step 6 : Salt-out: Add a salt water solution into the second solution to prepare a third solution (with a concentration of 0.8M), while shaking the solution severely until a cloudy substance if formed.
[0038] Step 7 : Collect lower-layer precipitate: Perform the centrifugal separation to the third solution in a second predetermined condition (wherein the weight of the second solution is equal to 22000 g) while collecting a lower-layer precipitate, and then place the lower-layer precipitate in water twice, while adding sodium hydroxide (NaOH) with a concentration of 0.1N) to adjust the pH value to form a fourth solution (with a pH value of 7).
[0039] Step 8 : Freeze Drying: Freeze the fourth solution at another predetermined temperature (−20° C.) for the predetermined time, and then dry the solution to obtain a collagen (which is a Type I collagen).
[0040] Step 9 : Mix with the γ-polyglutarmic acid (γ-PGA): Prepare the collagen as a collagen solution (with a concentration of 35 mg/ml), while mixing a predetermined quantity (4 ml) of the collagen solution with the same predetermined quantity of γ-polyglutarmic acid (γ-PGA) to produce a fifth solution.
[0041] Step 10 : Perform a first crosslinking: Titrate another predetermined quantity (0.5 ml) of glutaraldehyde solution (with a concentration of 0.05%) in the fifth solution by a pump (which is a tubing pump) while blending the solution at a predetermined rotating speed (250 rpm) for another predetermined time (30 minutes) to perform a first crosslinking to the collagen and glutaraldehyde in the fifth solution.
[0042] Step 11 : Perform a second crosslinking: Finally, repeat Step 10 to complete the second crosslinking to obtain the long-lasting collagen.
[0043] The degrade-resisting effect of the long-lasting collagen of the invention can be proved according to a Bicinchoninic acid (BCA) testing procedure:
[0044] 1. Uniformly mix a testing agent A and a testing agent B in a ratio of 50:1 by volume to prepare a BCA testing agent.
[0045] 2. Add a sample A, a sample B and a sample C of 25 μl each into each groove of a 96-hole titration plate.
[0046] 3. Add 200 μl of the BCA into each groove, and let it sit still at 37° C. for 30 minutes, such that each sample is reacted completely.
[0047] 4. Finally, measure the absorption value of each group sample by an immune enzyme spectrophotometer, wherein the measuring wavelength is 650 nm.
[0048] In the preparation of the testing agent A, 40 mg of sodium tartrate (Na 2 C 4 H 4 O 6 .2H 2 O) is dissolved in 10 ml of 0.5M sodium hydroxide (NaOH) solution. After the sodium tartrate is dissolved completely, 1 g of sodium carbonate (Na 2 CO 3 ) is added and blended with the solution until the solution is in a clear transparent state.
[0049] In the preparation of the testing agent B, 0.2 g of sodium tartrate (Na 2 C 4 H 4 O 6 .2H 2 O) is dissolved in 2 ml of 0.5M sodium hydroxide (NaOH). After the sodium tartrate is dissolved completely, deionized (DI) water is added until the volume of the solution reaches 10 ml, and finally 0.3 g copper sulfate (CuSO 4 ) is added into the solution until the solution is in a clear blue state.
[0050] The Group A sample is 4 ml of collagen solution at a concentration of 35 mg/ml.
[0051] The Group b sample is 4 ml of collagen solution at a concentration of 35 mg/ml, and 0.5 ml of the glutaraldehyde solution is dropped within one minute by the pump, while blending and mixing the solution uniformly at a rotating speed of 250 rpm to perform a first crosslinking. After the first crosslinking, 0.5 ml of glutaraldehyde solution is dropped, and blended to mix with the solution at a rotating speed of 250 rpm for 30 minutes to perform a second crosslinking. In the preparation of the glutaraldehyde solution, 400 μL of glutaraldehyde is dissolved into 7.6 ml of the phosphate-buffered saline (PBS) solution to complete preparing the glutaraldehyde solution at a concentration of 0.5%.
[0052] The Group C sample is the long-lasting collagen obtained from the manufacturing method in accordance with the present invention, and the BCA testing method is adopted for the testing, and thus it is necessary to dissolve the γ-polyglutarmic acid (γ-PGA) into a phosphate-buffered saline (PBS) solution for completing the testing.
[0053] In addition, the BCA testing method is used for testing a standard collagen solution to obtain an absorption value x at a wavelength 650 nm of the standard collagen solution, while the absorption value x is substituted in an equation y=0.002x+0.074 to obtain a value of y, wherein the value of y in the equation indicates the concentration of peptide linkage in the standard collagen solution to obtain the graph of the standard collagen solution as shown in FIG. 3 . In the figure, the relation of an absorption value at a wavelength 650 nm of the standard collagen solution versus a concentration of a peptide linkage is shown.
[0054] In the standard collagen solution, 2 ml of collagen at a concentration of 35 mg/ml is dissolved in 5 ml of 0.025N acetic acid solution, and then the phosphate-buffered saline (PBS) solution is diluted to complete the preparation of the standard collagen solution.
[0055] With reference to FIG. 4 for Group A, B and C samples in collagenases of the same concentration, the testing results obtained by the BCA testing method show that: On the 11 th day of the experiment, the concentration of the solution of Group A sample in the peptide linkage is 2.052 mg/ml; the concentration the solution of Group B sample in the peptide linkage is 1.77 mg/ml; and the concentration of the solution of Group C sample in the peptide linkage is 0.87 mg/ml. From the aforementioned results obtained from the same experimental conditions, the degrading speed of the Group C sample is much slower than the degrading speeds of the Group A and B samples, indicating that the Group C sample has a better resistance to the degrading effect and a slower degrading speed of the enzymes in human body approximately equal to half of that of the Group B sample. From the present clinical testing result, the Group B sample can be stored and remained in human body for 6˜9 months, and thus we infer that the storage time of the Group C sample in human body is approximately equal to 12˜18 months.
[0056] On the other hand, the γ-polyglutarmic acid (γ-PGA) in the the Group C sample is linked by a γ-linkage, and the amine linkage in human body is an α-linkage, and thus the enzyme for degrading the γ-linkage of a DNA sequence in a human body is in an inactivated state. Researches point out that it takes 6˜7 months to activate this enzyme, and thus if a polypeptide of the γ-linkage enters into a human body, it will take at least 6˜7 months to start degrading the polypeptide, indicating that a γ-polyglutarmic acid (γ-PGA) and a collagen polymer material (such as the Group C sample) takes at least 18˜25 months to be degraded completely in human body.
[0057] A cell (a 3T3 fibroblast) is used for evaluating the biocompatibility of the Group A, B and C samples: the Group A, B and C samples are cultivated together with the cell for 3 days. With the following data, we can know about the information of cell activity, survival rate, quantity, senescence and genetic toxicity:
[0058] 1. Mitochondrial activity assay (MTT): From the testing of the mitochondrial activity of the cells cultivated together with the Group A, B and C samples, we can know about the activity of the cells.
[0059] 2. Lactate Dehydrogenase (LDH): From the testing of the Lactate Dehydrogenase (LDH) in the cells cultivated together with the Group A, B and C samples, we can measure the survival rate of the cells.
[0060] 3. Total DNA Content: From the testing of the total DNA content in the cells cultivated together with the Group A, B and C samples, we can analyze the quantity of the cells.
[0061] 4. b-galactosidase: From the testing of the b-galactosidase in the cells cultivated together with the Group A, B and C samples, we can measure the senescence of the cells.
[0062] 5. Chromosome Aberration: A Giemsa stain is used to test the chromosome aberration cultivated together with the Group A, B and C samples, we can know about the genetic toxicity of the Group A, B and C samples to the cells.
[0063] The testing results are listed in the following table, wherein the control group in the table is the aforementioned standard collagen solution:
[0000]
Control Group
Group A Sample
Group B Sample
Group C Sample
Mitochondrial activity assay
0.643 ± 0.154
0.682 ± 0.124
0.611 ± 0.173
0.692 ± 0.189
(MTT)
Lactate Dehydrogenase (LDH)
0.487 ± 0.094
0.503 ± 0.163
0.476 ± 0.120
0.511 ± 0.143
Total DNA Content
0.833 ± 0.144
0.789 ± 0.159
0.810 ± 0.201
0.805 ± 0.176
b-galactosidase
0.418 ± 0.067
0.512 ± 0.169
0.543 ± 0.112
0.498 ± 0.128
Chromosome Aberration
6.8%
5.88%
7.92%
6.73%
[0064] From the table above, we can observe that the Group A, B and C samples, the mitochondrial enzyme activity (MTT), lactate dehydrogenase (LDH), total DNA content, b-galactosidase and chromosome aberration are statistically consistent, and thus it shows that Group A, B and C samples do not contain cell poison and cause a change of chromosomes, and these samples have a good biocompatibility.
[0065] From the data as shown in the table, the main difference between the long-lasting collagen of the invention and the conventional collagen resides on that:
[0066] 1. The invention complies with the novelty and improvement requirements of a patent application. In the present invention, the γ-polyglutarmic acid (γ-PGA) is added into a collagen and gone through a crosslinking process twice to obtain the long-lasting collagen, so as to overcome the shortcomings of the conventional collagen having a short storage time and requiring a frequent resupply of collagen by injection.
[0067] 2. The invention complies with the practicability requirement of a patent application. In the present invention, glutaraldehyde of a low concentration goes through a crosslinking process twice to uniformly and completely crosslink the collagen with the glutaraldehyde to obtain a very low-concentration remained glutaraldehyde, while the long-lasting collagen has a better biocompatibility.
[0068] While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. | In a long-lasting collagen and its manufacturing method, a pig skin is gone through processes of scraping extra tissues, removing fats, imbibition, digesting, centrifugal separation, salting-out, collecting lower-layer precipitate and freeze-drying to form a collagen, and the collagen is mixed with γ-PGA, and then a glutaraldehyde solution is added and mixed uniformly to perform a first crosslinking and form the long-lasting collagen, so as to overcome the shortcomings of a conventional collagen having a short storage time, a requirement of applying the collagen repeatedly, and a high concentration of remained glutaradldehyde which is biologically poisonous to human bodies. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 12/290,352 filed Oct. 30, 2008, which in turn claims priority of U.S. application Ser. No. 10/854,123 filed May 26, 2004, the disclosure of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
FIELD OF INVENTION
This invention relates to continuous digesters for wood chips in the papermaking industry.
BACKGROUND OF INVENTION
As commonly practiced in the prior art relating to papermaking, wood chips and alkali liquor (white liquor) are pumped into the top of a hydraulic cooking vessel (digester, approximately 180 feet high and approximately 23 feet in diameter) that is operated at high pressure (165 psig) and temperature (325 degrees F.). A chip cooking process proceeds over the time that it takes the saturated chip column to move down through the digester where the discharge rate of the chips to a blow line at the bottom of the digester is matched to the feed rate at the top so as to maintain a constant level and retention time of the chips in the digester.
In the cooking process (delignification of wood chips), approximately 50% of the organic chip mass is dissolved in the cooking liquor. At 1 to 3 locations above the lower section of the digester, liquor containing the dissolved solids is removed from the vessel by extracting liquor through sets of screens in the circumferential wall of the digester, the screens being aligned with the inner wall of the digester vessel. The screens are 3 to 4 feet in height. The wash screens are the lowest (often the only) set of screens in a continuous digester and are located 10 to 20 feet up from the bottom of the digester. The screen plates are made from stainless steel with multiple slots cut in them that are 0.12 to 0.35 inch wide by 3 to 4 inches long depending on the location in the digester. The liquor that is extracted can be sent to a chemical recovery system where the liquor solids are concentrated and the organic solids burned in a chemical recovery boiler. The chemicals (inorganic solids) are recovered in the bottom of the recovery boiler and re-used to produce white liquor for the cooking process.
Just prior to discharge from the digester bottom, the chip mass is washed and cooled by cold (120 to 150 degrees F.) filtrate which is generated externally of the digester (from black liquor for example) and introduced into the wash zone of the digester. As much as possible remaining organic/inorganic material dissolved in the cooking liquor is removed from the chip column by a displacement and diffusion wash in the bottom of the digester by extraction of high-dissolved-solids hot liquor through the wash screens. To displace the high-solids hot liquor and to cool the chip mass, cooled black liquor filtrate is added to the bottom of the digester at several locations in the wash zone.
In some instances, some of the liquor extracted and/or a combination of lower solids liquors (black liquor and/or white liquor) is added to a center pipe (downcomer) in the digester that discharges in the center of the chip column adjacent to a given set of screens. The liquor added to the center pipe at least partially displaces the liquor being pulled through the extraction screens at such given set of screens.
In summary, the purpose of the wash screens is to remove high solids filtrate from the chip column as it passes these screens by the efficient displacement and diffusion wash with cooler and cleaner liquor added to counter wash nozzles, to ring dilution nozzles and/or to the center of the chip mass via a downcomer that discharges adjacent to these screens. The efficiency of the wash is measured by the extent to which there is maintained optimum low temperature of the chip mass discharged from the digester with concomitant minimization of the cooling of the wash liquor added to the wash zone.
Because of the nature of the compaction of the chip column, it is difficult to predict and/or control the uniform flow of re-circulation flows or free liquor upflows (i.e., counter-current) or downflows (i.e., co-current) through the chip mass in a large diameter continuous digester of the prior art. In the wash zone, there is a tendency for upflows to short circuit up the sides of the digester and for liquor contained in the chip mass to be carried co-currently down with the chip mass only to be displaced from the chip mass at the very bottom of the wash zone.
Temperature and alkali uniformity in the wash zone are impacted by flows at the bottom of the wash zone and in the wash zone of the digester. The temperature and alkali uniformity in the wash zone are key factors in achieving uniform cook (delignification) across the column. Uniform delignification reduces cellulose (pulp fiber) attack, helping to achieve overall maximum pulp fiber strength and yield. Cook non-uniformity across the column profile, with accompanying non-uniform retention of lignin on the individual fibers is a common deficiency of known prior art digesters.
As noted, in the prior art, The liquor added to the bottom of the chip mass passes through the chip column via paths of least resistance to the wash screens. The wash screens accommodate this process anomaly by removing the most easily removable flow to support the total wash screens flow. This results in poor displacement and diffusion of dissolved solids (poor wash efficiency) in the chip mass to the wash screens and poor heat transfer in some portions of the chip column. The poor wash efficiency causes downstream problems in the brown stock treatment and bleaching processes. The poor heat transfer in the chip column at the bottom of the digester increases the energy costs in these two affected process areas. Also, during operation, individual wash screens tend to plug off completely with the other screens picking up the flow. Continuous digesters are only shut down for maintenance on an annual basis, due to cost of such shutdowns. In some cases it has been observed that one or two wash screens will plug and remain plugged for the remainder of the year only to be unplugged during the annual shut down. The chip column adjacent to plugged wash screens leads to poor wash efficiency and poor heat transfer.
Thus, the prior art is deficient in that:
1. The flow through each of the wash screens is variable and dependent on the path of least resistance flow of wash filtrate added to the bottom of the digester. This is observed physically by the wide variance in wash screen exit nozzle temperatures. 2. There is no known current method to control the individual wash screen flow and temperature in order to break up the pattern of path of least resistance flow of cold blow wash filtrate. Further, there is currently no known method to unplug the wash screens other than when the digester is empty during the annual shut down. 3. The upflow through the wash zone is operated at higher than optimum for alkali and temperature profile uniformity because of the current inability to manage and maintain an acceptable wash efficiency in the bottom of the digester. 4. There is no known current method for adjusting the amount of free liquor upflow through the wash zone in order to maintain uniformity of temperature and alkali in the wash zone where the highest percentage of the cook (time at temperature) is completed with the highest potential for product non-uniformity to be affected. Currently, in the prior art, a higher free liquor upflow is maintained in order to compensate for the non-uniformity of the operation of the wash screens. Whereas this higher free liquor upflow helps to manage the dissolved solids level in the digester discharge, such flow has a negative impact on the temperature and alkali profiles in the wash zone.
SUMMARY OF INVENTION
In accordance with one aspect of the present invention, the total volume of liquor withdrawn from the digester through the wash screens within the wash zone of the digester is uniformly and automatically distributed between all of the wash screens. To this end, in accordance with the present invention there are installed individual temperature measurement, flow measurement and flow control valves in association with each of the wash screen to control the flow through such wash screen to maximize energy and wash efficiency. Further, this feature provides for sensing of a screen in difficulty and individual isolation of a screen by closing it's flow control valve to allow the down flowing chip column to wipe a screen thereby cleaning and avoiding total plugging of the screen as occurs in the prior art.
Additionally, in the present invention, there is provided a central downcomer within the digester. This downcomer includes side discharge ports adjacent to the bottom end of the downcomer through which filtrate liquor is discharged into the digester. These discharge ports of the downcomer are disposed substantially radially of the surrounding wash screens such that the discharge streams of filtrate liquor from the ports are directed substantially radially toward the surrounding screens, thereby creating a layer of filtrate liquor flowing perpendicularly from the center of the digester toward all the screens. This flow pattern of liquor filtrate is directed across the downward flow of the chip mass and has been found to break up or discourage formation of upflow/downflow streams of filtrate liquor within the area of the screens.
As desired, the piping associated with the wash screens may be provided with automatic or manual back flush apparatus to allow reverse flow of filtrate through the screens to assist in clearing a screen that is showing signs of plugging.
Still further, in accordance with one aspect of the present invention the present inventors have found that reducing the wash zone free liquor upflow (i.e., counter-current) or establish a free liquid downflow (i.e., co-current) (as for example a free liquor upflow of from about the current 0.25 gpm/ADt/d (US gallons per minute per air dry tonne per day to a 0.007 gpm/ADt/d of free liquor upflow, i.e., counter-current or downflow, i.e., co-current)), provides improved uniformity of the product leaving the wash zone.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects and advantages of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
FIG. 1 is a schematic representation of a typical wood chip digester embodying various of the features of the present invention;
FIG. 2 is a schematic representation of a portion of the digester depicted in FIG. 1 and taken along the circle 2 of FIG. 1 ;
FIG. 3 is a schematic representation of various piping elements and flow directions of fluids into the digester from a downcomer and out of the digester via control elements associated with the present invention; and
FIG. 4 is detailed side view of the distal end of a downcomer as depicted in FIG. 1 .
DETAILED DESCRIPTION OF INVENTION
In the embodiment of the present invention depicted in FIGS. 1 and 2 , as noted hereinabove, approximately 50% of the organic chip mass 10 is dissolved in the looking liquor. The depicted digester 14 includes an upper zone 13 into which the chip mass is loaded. This is also the cooking zone. A set 16 of screens, twelve screens 18 in a typical embodiment, are disposed about the inner circumferential wall 20 of the digester at a location just below the cooking zone 13 and above a wash zone 24 which is disposed at the bottom end of the digester.
Liquor containing dissolved solids is extracted from the interior of the digester through the screens. The liquor extracted through the individual screens is conveyed to a discharge header 28 which encircles the girth of the digester externally of the digester in the region of the screens and is conveyed, as by a pump system 30 , to a chemical recovery station 32 or is selectively returned in part to the digester via a downcomer 54 . As desired, a heater may be interposed within the piping between the pump station and the downcomer to heat the filtrate prior to its return to the digester. The downcomer is located centrally of the digester and includes discharge ports 38 adjacent the lowermost end of the downcomer. As depicted in FIG. 1 , these ports are disposed substantially radially equidistant from the surrounding screens such that the filtrate liquor discharged through the ports is directed substantially radially outwardly (see arrows of FIG. 1 ) from the downcomer ports thereby ensuring that the filtrate liquor discharged from the downcomer flows simultaneously and substantially uniformly radially toward all of the screens. When the filtrate liquor discharged into the chip mass adjacent the wash screens is heated to about the cook filtrate liquor temperature, and by reason of the radially lateral flow of the discharge filtrate liquor, upflow or downflow of the liquor through the chip mass in the area of the screens is prevented or discouraged.
As needed or desired, black liquor from one or more known sources in a papermaking facility may be added to the filtrate liquor which is extracted from the screens and fed to the downcomer.
In the depicted digester, there is provided a single set 16 of wash screens includes multiple separate screens 18 covering the digester circumference. As noted, these screens serve to permit the withdrawal of hot liquor containing dissolved organic/inorganic solids from the digester for reuse or recovery of the individual components of the extracted filtrate. In accordance with one aspect of the present invention, and referring to FIGS. 1 and 2 , conveyance of extracted filtrate from each screen 18 is effected by means of a stub pipe 26 disposed behind each screen 18 and serves to accept the liquor extracted from the digester by the screen and to convey the same away from the screen. This stub pipe is in fluid flow communication with a discharge ring header 28 which encircles the digester outside of and along the outer wall 42 of the digester and which serves to convey the filtrate from the several screens to a pump station.
With specific reference to FIGS. 2 and 3 , in accordance with the present invention, a continuous digester 14 having a set 16 of screens 18 disposed about its inner circumference 20 for withdrawal from the digester through the screen solids-bearing hot liquor, is provided with a combination of elements associated with the stub pipe 26 which is in fluid communication between each screen and a generally circular discharge collection header 28 disposed externally about the outer circumference of the digester. In the depicted embodiment of the invention, these elements are interposed along the length of the stub pipe and between the outer wall of the digester and the header. Each such combination of elements includes a first manual valve 50 located adjacent the digester outer wall, a temperature sensor 52 next to the first manual valve, an electronically controlled valve 54 next to the temperature sensor, a flowmeter 56 next to the electronically controlled valve, and a second manually operated valve 58 adjacent the header. As seen in FIG. 1 , the header is in fluid communication with a pump 30 which functions to draw the hot liquor extracted by each screen through the header to remote locations such as a chemical recovery station 32 , etc.
FIG. 3 schematically depicts the combination of elements referenced above and shows the association of a combination of elements associated with each individual screen. In this FIG. 3 , the valves associated with back wash of each screen, as seen in FIG. 2 , have been omitted for purposes of clarity.
In the present invention, hot liquor extracted from the digester through a given screen flows through the combination of elements which are interposed between the digester and the header. In the depicted embodiment, the discharge flow of hot liquor initially encounters the first manual valve 50 . This valve is manually operable to provide a means for manually adjusting the outflow from a given screen to either full flow, partial flow, or no flow. Next in line, the discharge flow encounters the temperature sensor 52 which includes an electrical lead 60 that passes to a controller 62 . Next in line, the discharge flow encounters the electronically controlled valve 54 having an electrical lead 64 that passes to the controller. Next in line, the discharge flow encounters the flowmeter 56 which also includes an electrical lead 66 which passes to the controller. Finally in line, the discharge flow encounters the second manually operated valve 58 and then flows into the header 28 . In the depicted embodiment there is provided a conduit 68 which intersects the stub pipe at a location between the flowmeter and the second manual valve. This conduit is provided with a third manually operated valve 70 .
Operationally, the first manually operated valve 50 functions to allow manual control over the flow through the stub pipe (irrespective of direction of flow) as either full flow, partial flow or no flow. Thus, this first valve functions as a type of override to any automatic control over the flow between the digester and the header, and in a backwash situation to assist in the flow control of backwash liquid to a screen. For back washing of a screen, the automatic control of the flow of discharge liquor from the screen toward the header is deactivated (as by the controller), the second manual valve 58 is closed to close off all flow to the header, and the third valve 70 is opened to admit backwash liquid into the stub pipe, thence to the screen at a flow rate which can be selected by either or both of the first and third manual valves.
During normal operation of the digester, with the second and third manual valves closed, and the first manual valve open, the outflow of hot liquor through each of the screens of the set of screens is selected automatically via the controller. Specifically, as hot liquor is withdrawn through a given screen, under the influence of the pump 30 , this discharge liquor encounters the temperature sensor 52 which senses the temperature of the discharge flow and develops an electrical signal which is representative of such flow and transmits such signal to the controller. Like signals representative of the temperature of the discharge flow from each of the screens are fed into the controller where these temperatures are compared to one another and to a temperature which is representative of the desired flow from each screen and which serves as a standard against which each of the discharge flows of each of the screens is compared. Variations in the temperature of the discharge flow from a given screen from the standard temperature are indicative, first, of the existence of flow from the screen, and, second, of the possible existence of cool upflow liquor from the wash zone reaching the screen without passing through the chip mass as a disbursed stream.
After the discharge flow passes the temperature sensor, it encounters the electronically controlled valve 54 which functions to adjust the rate of discharge flow to a value which is determined by the controller.
Downstream of the electronically controlled valve, the discharge flow encounters the flowmeter whose function is to sense the rate of flow of the discharge liquor through the stub pipe, generate an electrical signal representative of the sensed rate of flow and transmit such signal to the controller via the electrical lead 66 .
From the foregoing, it will be evident that if a screen is fully plugged, all flow of hot liquor through the screen will be halted. In this event, the there is no flowing hot liquor to contribute to the temperature sensed by the temperature sensor so this sensor will report to the controller a relatively cool temperature. Within the controller this cooler temperature will be compared to the normal hot liquor temperature, or other set temperature, and generate a signal to the operator to alert the operator to this undesirable condition. Likewise, the flowmeter will signal the controller that there is no flow through the stub pipe, this condition also possibly being the result of a plugged screen. In the present system, to avoid actual full plugging of a screen, the controller may be set to alert the operator when there is only a small drop in the temperature of hot liquor and/or small drop in the flow rate of the hot liquor passing through the stub pipe so that the operator may take remedial action immediately to remedy the plugging of the screen. This combination of a reduction in the anticipated flow rate through a stub pipe as sensed by the flowmeter which also sends to the controller a signal representative of such reduced flow to the controller, with the sensed reduction in temperature of the flowing hot liquor provides a novel improved concept for monitoring the operability of each individual screen. Thus, the signal from the flowmeter provides the controller with a signal, which compliments the signal to the controller from the temperature sensor.
In like manner, if the temperature within the stub pipe is within a range recognized by the controller as acceptable, but the flow rate of hot liquor through a given stub pipe increases above a standard value set in the controller, such conditions may indicate that more than anticipated hot liquor is flowing through the given stub pipe. This condition can be indicative of the lack of contribution to the overall desired discharge rate of hot liquor from the digester by one or more of the other screens, for example, and an alert to the operator to at least investigate the digester operating conditions and, if needed, take remedial action. Thus, it is seen that the combination of the temperature sensor and the flow meter are essential to the successful functioning of the present invention.
Further, if the rate of flow of hot liquor through the stub pipe is within a range set in the controller, but the temperature of the flow of hot liquor is lower than anticipated, such condition may be indicative of relative cool wash liquor moving upwardly of the digester into the area of the screens, such flow of cool wash water being possibly due to too much wash water being added to the bottom end of the digester or the existence of excess upflow of the wash liquor to a given screen or screens.
Other combinations of sensed temperature and independently sensed flow rate may be indicative of other operating conditions within the digester which may call for operator interdiction. For example, since the flow of hot liquor from each screen is monitored, both for temperature and flow rate, independently of every other screen, it may be readily determined if one or more screens is not functioning as desired, and importantly, which one or more screens is involved, thereby localizing a malfunction within the digester.
The present invention provides prompt and early indication of a source of possible trouble with respect to the outflow of hot liquor from the digester. In this respect, if a given screen or screens is noted to be plugging, the operator can close down outflow from such screen or screens, thereby allowing the downflowing chip stream to sweep the surface of the screen interiorly of the digester and remove all or part of any material which is attempting to plug the screen or screens. If this technique is unsuccessful, the operator further has the option of back washing the screen or screens individually employing the first, second and third manually operable valve which are associated with the stub pipe of each screen.
In accordance with one aspect of the present invention, hot liquor withdrawn from the digester through the screens and after being subjected to chemical recovery, is reintroduced to the interior of the digester through the downcomer which is aligned with the vertical centerline 74 . In the present invention, contrary to the prior art, the discharge ports in the bottom end of the downcomer are disposed both centrally of the interior of the digester and radially aligned with the screens which surround the downcomer. In this manner, the present inventors provide for the injection into the chip mass of a substantially circular sheet of fresh hot liquor which flows from the downcomer ports radially toward the screens. This flowing sheet of hot liquor has been found to eliminate or substantially discourage the development of upflows or downflows within the chip mass at substantially all points radially between the downcomer and the screens in the digester wall. This effect has been particularly noted in the regions of the perpendicular cross-section of the digester at the level of the screens and adjacent the screens for reasons not fully understood.
In addition to the recycling of treated hot liquor which has been withdrawn from the digester via the discharge header and fed back into the digester via the downcomer, cold filtrate (below the cooking temperature of the chip mass in the digester) from black liquor sources common in a papermaking facility, may be introduced into the bottom end of the digester as wash liquor as by a pump and associated piping as is known in the art. As desired or needed, such black liquor may be added to the digester through the downcomer, either as a substitute for hot liquor from the chemical recovery station or as an additive to the hot liquor from the recovery station.
Control over the flow of black liquor into the digester may be controlled through the controller, and a plurality of electrically operable valves, such as valves 73 , 76 and 78 . Each of these, and all others of the electrically operable valves includes a respective electrical lead between the controller and each such valve. In the Figures, the electrical leads from these and others of the electrically responsive elements are indicated in dashed lines for purposes of clarity, but in all instances these electrical leads extend between the respective valve or element and the controller. | A continuous digester comprises a wash zone having a plurality of individual wash screens disposed about an inner wall of the digester for the withdrawal of co-current downflow liquor from the wash zone. A conduit is connected in fluid communication between each of the wash screens and a collector for co-current downflow liquor withdrawn from the wash zone of the digester. A valve is interposed along the length of the conduit leading from each of the wash screens. The valve is operable between open and closed positions in response to a signal received from a temperature sensor associated with the conduit leading from each of the wash screens. The signal represent changes in temperature of a corresponding co-current down flow liquor through a corresponding conduit wherein a corresponding valve permits adjustment of a corresponding flow rate of liquor through said corresponding conduit to a flow rate that is substantially equal to each of the other flow rates of co-current downflow liquor through each of the other conduits. | 3 |
RELATED APPLICATION(S)
The present patent application claims priority to Provisional Patent Application No. 61/795,536 filed Oct. 19, 2012, which is assigned to the assignee hereof and filed by the inventors hereof and which is incorporated by reference herein.
BACKGROUND
Field
The present disclosure relates to a thermal management system with three-dimensional interconnected porous graphene (3DX-IPG) nanostructured films used as thermal interface materials (TIMs).
Background
Graphene is a one atomic layer sheet of carbon atoms with double electron bonds. It is reported that graphene has ultra-high thermal conductivity (˜4000 W/m·K). Graphene and its chemical derivatives such as graphene oxide and reduced graphene oxide have been widely used as conductive fillers in polymer matrices to produce thermal conductive composites. The thermal conductivity of graphene-based composites is typically much lower than the bulk thermal conductivity of graphene, and may not display significant advantages over conventional composite-based thermal interface materials (TIMs). Chemically or physically bonded graphene paper has been proposed as a thermal interface material. The graphene paper is typically produced from chemically exfoliated graphene, and typically suffers from the poor thermal conductivity due to the defects generated in graphene sheets during the chemical exfoliation process. Furthermore, the chemical derivative graphene sheets in graphene paper are typically stacked in parallel, resulting in anisotropic in thermal transport and limiting the thermal transport in the vertical direction.
The use of graphene foam (GF) was described by Chen Z P, Ren W C, Gao L B, Liu B L, Pei S F, Cheng H M. Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapour deposition, Nat. Mater. 2011; 10: 424-428. That reference describes the production or manufacturing method for GF.
SUMMARY
A thermal interface material (TIM) is constructed and used for increasing thermal conduction or thermal dissipation across an interface. The TIM is made from a three-dimensional interconnected porous graphene (3D-IPG) foam structure constructed of three-dimensional interconnected graphene sheets formed as a plurality of monolayers or few layers. The graphene sheets have an flexible interconnection architecture, in which the flexible interconnection architectures allow the 3D-IPG to maintain a high interfacial thermal conductance by the 3D-IPG filling a gap between a heat source and a heat sink across the interface, and by capping small features up to nanoscale roughened surfaces.
The 3D-IPG foam structure provides a flexible interconnection architectures, allowing the 3D-IPG to maintain a high interfacial thermal conductance by the 3D-IPG filling a gap between a heat source and a heat sink across the interface, thereby reducing thermal resistance between the mating surfaces and providing high thermal conductivity and a high surface area to 3D-IPG function as an effective heat dissipater, heat sink or heat convector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a thermal dissipation structure where GF-based thermal interface material (TIM) acts as the interface layer.
FIG. 2 is a schematic diagram of a practical example of a GF-based thermal dissipation structure, where the heat source is a LED-package.
FIG. 3 is a graphic depiction of thermal interfacial resistance of GF at a Si—Al interface as compared with other commonly used particle filled polymer based and carbon-based TIMs.
FIG. 4 is a schematic diagram of a thermal management system based on 3D-IDG TIM with an encapsulant layer.
FIGS. 5A and 5B are images of 3D-IPG film. FIG. 5A is a photographic image of a free-standing 3D-IPG film. FIG. 5B is an image of a 3D-IPG film supported on a silicon wafer.
FIGS. 6A and 6B are SEM images of the 3D-IPG film.
FIGS. 7A and B are digital photo images of the materials after disassembly following a thermal resistance test. FIG. 7A shows the silicon and FIG. 7B shows the aluminum plate.
FIG. 8 is a graph showing cumulative structure functions of LED-packages with different TIM layer.
DETAILED DESCRIPTION
Overview
The present disclosure describes a thermal management system using thermal interface materials made from interconnected 3D graphene nanostructured films. This disclosure demonstrates superior heat dissipation performance of three-dimensional interconnected porous graphene (3DX-IPG) as thermal interface materials (TIMs). Several thermal management systems based on 3D-IPG film are provided.
Three-dimensional (3D) interconnected porous graphene (IPG) nanostructured films are used as thermal interface materials (TIM) for thermal management. The disclosed technology provides a thermal dissipation structure by using graphene, which may, by way of non-limiting example, take the form of graphene foam (GF)-based thermal interface materials (TIM) as a thermal interface layer. The disclosure provides techniques for manufacturing of thermal interface materials derived from GF, such as the production of GF having metal nanoparticle material added as a mixture component.
The 3D-IPG films are constructed with graphene sheets having a thickness from a few nanometers to hundreds of nanometers. 3D-IPG films, with thickness from a few micrometers to centimeters, are inserted between a heat source and a heat sink to enhance the heat dissipation. The heat source and a heat sink can be any physical structure that emits and absorbs thermal energy, respectively. The interconnected graphene structure allows ultra-high efficiency in heat transfer from heat source to heat sink. The 3D-IPG films can also be a heat sink, heat convector, and heat spreader for high power electronics devices, such as, by way of non-limiting examples, micro-processors and light emitting devices. 3D-IPG materials can be modified or filled by any nanomaterials, thermal conductive fillers or chemical dopants to further enhance the thermal conductivity and decrease the thermal interface resistance. The 3D-IPG materials can be modified with additives, such as metals, carbon fibers, metal oxides, ceramics, to further enhance their mechanical strength. 3D-IPG based thermal management systems can be formed of 3D-IPG materials sealed by encapsulants or sealants. Furthermore, the porous structures of 3D-IPG can be bonded in-between the heat source and heat sink by using a bonding agent.
3D-IPG is produced by a high-temperature chemical vapor deposition (CVD) method from a sacrificial template, and provides porous foam structures constructed by interconnected graphene sheets. The physical deposition conditions allow the 3D-IPG to maintain a high thermal conductivity. The interconnected 3D networking of graphene greatly reduces the interfacial resistance between graphene sheets and facilitates the heat transport both vertically and horizontally. Distinguishing characteristics of 3D-IPG are that the porous film is highly flexible and deformable. While acting as a thermal interface material (TIM), 3D-IPG can easily fill in the gap between the heat source and heat sink. The 3D-IPG can also cap or the small features (up to nanoscale roughened surface) by filling in gaps between peaks of the surface to present a smooth interface. This greatly reduces the thermal resistance between the mating surfaces. Thus 3D-IPG is a superior TIM for thermal management.
3D-IPG films can be produced from high-temperature chemical vapor deposition (CVD), or solution-grown 3D porous graphene oxide/reduced graphene oxides. The CVD can, by way of non-limiting example can be used to apply the 3D-IPG film through templating techniques such as nickel foam or a similar templating technique. The 3D-IPG films, with thickness from a few micrometers to centimeters, are inserted between a heat source and a heat sink to enhance the heat dissipation. The heat source and a heat sink can be any physical structure that emits and absorbs thermal energy, respectively. The interconnected graphene structure allows ultra-high efficiency in heat transfer from heat source to heat sink. The 3D-IPG film, due to its ultra-high thermal conductivity and ultra-high surface area, can also be an effective heat dissipater, heat sink or heat convector. The 3D-IPG film can also be a good heat spreader due to the ultra-high thermal conductivity in the in-plane direction. The various functions of heat dissipater, heat sink, heat convector and heat spreader obtained from use of 3D-IPG film can be applied in thermal management in high power electronics, such as microprocessor or light emitting devices. The 3D-IPG can be modified by any conductive nanomaterials, or chemical dopants to further enhance thermal conductivity and decrease thermal interface resistance.
3D-IPG can be modified with additives, such as metal or carbon fibers, to further enhance its mechanical strength. The 3D-IPG based thermal management system can be sealed by bonding agents or alternatively by encapsulants either with or without the use of bonding agents. The bonding agent is a substance that binds the IPG with heat sink or heat source, whereas the encapsulant searves to seal the IPG within the interface between the heat sink and the heat source. Furthermore, the porous structures of 3D-IPG can be bond in between the heat source and heat sink by using a bonding agent.
Structure
The disclosed technology provides a thermal dissipation structure by using graphene, which may, by way of non-limiting example, take the form of graphene foam (GF)-based thermal interface materials (TIM) as a thermal interface layer. FIG. 1 is a schematic diagram of a thermal dissipation structure where GF-based TIM functions as the interface layer. Depicted in FIG. 1 are heat source 101 and heat sink 103 . A layer of TIM 105 is placed between the heat source 101 and heat sink 103 in order to enhance conductivity between the heat source 101 and heat sink 103 , and also to reduce hot spots which may occur at the heat source 101 . In a sample used for demonstration, heat source 101 is a section of silicon wafer, which is caused to heat and heat sink 103 is an aluminum heat sink. The TIM 105 is either the graphene foam (GF) or a different material used for comparison purposes. As shown in FIG. 1 , the thermal dissipation structure comprises heat source 101 , heat sink 102 and GF-based thermal interface layer 103 inserted in-between the heat source and heat sink, and maintained under compressive pressure.
FIG. 2 is a schematic diagram of a practical example of a GF-based thermal dissipation structure, in which the heat source is a LED-package. Depicted are LED device 201 , leadframe 202 , which may include driver circuitry, and heat sink 203 . In this depiction, the TIM 205 is deposited between the leadframe 202 and the heat sink 203 .
FIG. 3 is a graphic depiction of thermal interfacial resistance of GF at a Si—Al interface. Thermal resistance (measured in cm 2 KW −1 ) is shown at different vertical levels. This is a one-dimensional graph similar to a bar graph, showing the resistances of the different materials. The horizontal dimension only serves to visually separate the representations of the different materials and does not represent an abscissa. Thermal resistance of commercial thermal grease (with nominal thermal conductivity of 0.6 Wm −1 K −1 ) and Ag-Silicone paste (with nominal thermal conductivity of 6.4 Wm −1 K −1 ) are presented as a benchmark. 3D-IPG has the lowest thermal resistance down to <0.05 cm 2 KW −1 , which is much lower than other commonly used particle filled polymer based TIM (grease and silver-silicone), Thermal interfacial resistance of some other previously reported carbon-based TIMs, including vertical-aligned carbon nanotubes (VCNT), carbon nanotube (CNT) buckypaper, and vertical-aligned reduced graphene oxide paper (VrGO) are also plotted for comparison. It is shown that thermal interfacial resistance was only 0.04±0.02 cm 2 KW −1 for the GF synthesized at both 900° C. and 1000° C. for 15 minutes.
TABLE I
Thermal interfacial resistance of three dimensional GF-base TIM
at Si—Al interface, in comparison with other carbon-based TIMs
Thermal Interfacial
Percentage
TIM
Resistance (cm 2 KW −1 )
difference (%)
GF-900° C.
0.040 ± 0.025
—
GF-1000° C.
0.043 ± 0.025
—
VCNT(first example)
0.07
75
VCNT (second example)
0.15
275
CNT paper
0.27
575
VrGO
0.07
75
As can be seen, the thermal interface property of the GF provides ultralow thermal interfacial resistance. The low thermal resistance was achieved by inserting the GF in-between a heat source and a heat sink under pressure. Referring to FIG. 3 and Table I, the thermal interfacial resistance of 3D GF has an enhancement of at least ˜75% to that of the best reported among carbon-based TIMs. This provides a good thermal management system, in which utilizing GF as TIM layer provides superior thermal dissipation performance. The following are non-limiting examples of the use of 3D-IPG film.
Example—3D-IPG TIM on Silicon Substrate with Bonding Agent
Referring again to FIG. 1 , TIM layer 105 is placed between the heat source 101 and heat sink 103 in order to enhance conductivity between the heat source 101 and heat sink 103 . TIM layer 105 includes a bonding agent, which is impregnated into the porous structures of 3D-IPG. This integrates the bonding agent with the 3D-IPG for bonding with heat source 101 and heat sink 103 . As a result of the bonding, good thermal contact is made between heat source 101 and TIM layer 105 and establishes good thermal contact between TIM layer 105 and heat sink 103 .
To demonstrate the utilization of 3D-IPG as a thermal interface layer bonded by binding agents/adhesives, the 3D-IPG was first deposited on a silicon substrate functioning as heat source 101 , followed by depositing a binding agent such as epoxy onto the 3D-IPG film 105 . Then the silicon with graphene film was attached to heat sink. The thermal management assembly was fixed after curing of epoxy.
The TIM can be constructed by modifying the 3D-IPG filling the 3D-IPG with additives or fillers in order to enhance the thermal conductivity. By way of non-limiting example, the modification can be performed by chemical/electrochemical deposition of metal/metal oxide nanoparticles on the inner walls/pores of 3D-IPG, by infiltration or by physical deposition of conductive metals, metal oxides, ceramics, particles or fibres, conductive polymer or phase change materials on the inner walls/pores of 3D-IPG. The TIM can also be constructed by modifying the 3D-IPG by the use of additives or fillers to enhance the mechanical strength, for example, by coating, infiltration or physical deposition of metals, metal oxides, ceramics, carbon fiber and/or polymers into the porous networking graphene structures.
Example—3D-IPG on Silicon Substrate with Encapsulant
FIG. .x4 is a schematic diagram of a thermal management system based on 3D-IDG TIM with an encapsulant layer. Depicted are heat source 401 , and heat sink 403 . As is the example of FIG. 1 , a layer of TIM 405 is placed between heat source 401 and heat sink 403 in order to enhance conductivity between heat source 401 and heat sink 403 . Also, as in the example of FIG. 1 , the thermal dissipation structure comprises heat source 401 , heat sink 403 and GF-based TIM 405 inserted in-between the heat source and heat sink, and maintained under compressive pressure. TIM 405 does not fully extend to the edge of the interface, and encapsulant material 409 covers the edges of the interface. Interface layer may including bonding material as described above and/or may be mechanically compressed between heat source 401 and heat sink 403 .
The depiction of FIG. 4 is essentially a cross-sectional view, in two dimensions; however, in most but not all cases, encapsulant material 409 will extend around the perimeter of the interface so as to seal or substantially seal TIM layer 405 .
To demonstrate the utilization of 3D-IPG as a thermal interface layer sealed with encapsulants, the 3D-IPG was directly deposited on a silicon substrate to mimic a semiconductor chip as heat source 401 . The silicon was then attached to a heat sink, such as an aluminum plate as heat sink 403 , to form a thermal management system in which 3D-IPG acts as TIM 405 . The periphery of TIM 405 layer was coated with an encapsulant 409 such as silicone.
Production Method
By way of non-limiting example, 3D graphene is produced by chemical vapor deposition growth of graphene onto commercial available porous Ni foam. The Ni foam acts as a sacrificial template for graphene deposition.
FIGS. 5A and B are photographs of GF film. FIG. 5A is a photographic image of a free-standing 3D-IPG film. FIG. 5B is an image of a 3D-IPG film supported on a silicon wafer. The graphene-supported Ni foam was treated with etchant (such as hydrochloride acid, ferric nitrate) to remove the Ni backbone and free-standing graphene porous film was produced, as shown in FIG. 5A . This graphene film can be transferred onto any solid substrate acting as heat source or heat sink. FIG. 5B shows the typical 3D-IPG film transferred onto a 1 inch silicon wafer. The 3D-IPG film can also be made by solution-grown aerogel from graphene oxides or reduced graphene oxides. Typically, graphene oxides or reduced graphene oxides were treated in solvents under high temperature and assembled into 3D porous interconnected films.
A sample 3D-IPG film was characterized by scanning electron microscopy (SEM). From the SEM images shown in FIGS. 6A and 6B , it is clearly shown that the IPG film was constructed from interconnected graphene sheets with the width of ˜50 μm and length of several hundred μm, to form the porous foam-like structure. The graphene sheets were featured with some foldings and corrugations, indicating the strong flexibility and conformability of 3D-IPG film to the mating surface, which is benefit to enhance the thermal transport power of 3D-IPG based TIM.
FIGS. 5A and 5B are images of 3D-IPG film. FIG. 5A is a photographic image of a free-standing 3D-IPG film. FIG. 5B is an image of a 3D-IPG film supported on a silicon wafer. The thermal resistance of 3D-IPG was tested by using the ASTM standard (ASTM-D5470). Generally, the 3D-IPG was transferred onto a 1 inch (2.5 cm) square silicon wafer (mimicking a semiconductor chip as a heat source) and covered on top by the 1 inch square (25 mm 2 ) aluminum plate (mimicking the heat sink). The thermal testing assembly was then inserted into the TIM tester for the test.
FIGS. 6A and 6B are SEM images of the 3D-IPG film. These figures show the images of the free-standing 3D-IPG film before having been assembled into the testing assembly.
FIGS. 7A and 7B are SEM images of the 3D-IPG film. The thermal management systems utilizing 3D-IPG as a thermal interface layer may be sealed with encapsulants or bonded by binding agents/adhesives. The images of FIGS. 7A and B show the materials after disassembly following a thermal resistance test during which the 3D-IPG was left on a 1 inch (2.5 cm) square silicon wafer. FIG. 7A shows the silicon and FIG. 7B shows the aluminum plate. The 3D-IPG was left on the 1 inch square silicon wafer.
Example—LED Package
FIG. 8 is a graph showing cumulative structure functions of LED-packages with different TIM layer: GF (left line on the right side of the graph), air (right line on the right side of the graph), and thermal grease (center line on the right side of the graph).
The performance of GF-based TIM for heat dissipation of a LED-package was tested by a T3ster system. The power of the LED chip is 0.1 W and the size of package is 1×2.3 cm 2 . The LED-package was fixed on a heat-sink with a GF inserted in-between. The total thermal resistance of the package was measured in pulse mode. The thermal resistances of the package with air and thermal grease were tested for comparison. FIG. 8 shows the cumulative structure functions of the package with different TIM layers.
It is seen from FIG. 8 , the total thermal resistance of the LED-package with GF is the lower than that of the thermal grease. The thermal grease decreased the thermal resistance of ˜0.61K/W, while the GF decreased the total thermal resistance of ˜1.07 K/W. C th is thermal capacitance and its unit is Ws/K. R th is the thermal resistance and its unit is K/W. Taken into consideration of the contact area of GF ˜2.3 cm 2 , the thermal interfacial resistance of the LED-package has a decrease of about 2.46 cm 2 K/W with GF as a TIM layer, which is of ˜75% enhancement to that of the thermal grease. The result clearly demonstrates the great potentials of GF in acting as TIM layer within a thermal dissipation system.
CONCLUSION
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated to explain the nature of the subject matter, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. | A thermal interface material provides thermal conduction or thermal dissipation across an interface, using a three-dimensional interconnected porous graphene (3D-IPG) foam structure. The 3D-IPG foam structure is constructed of three-dimensional interconnected graphene sheets formed as a plurality of monolayers, and having an flexible interconnection architecture. The flexible interconnection architectures allow the 3D-IPG to maintain a high interfacial thermal conductance by the 3D-IPG filling a gap between a heat source and a heat sink across the interface, and by capping small features up to nanoscale roughened surfaces. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/987,457, filed Jul. 26, 2013, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This disclosure relates to tubular diaphragms with means for regulation of flow of fluids, including liquids, gasses, and emulsions, through a passage, that incorporate the embodiments and concepts in this disclosure.
BRIEF SUMMARY OF THE INVENTION
[0003] Embodiments comprise tubular diaphragms with a premolded shape giving them an enhanced lifetime in use. Embodiments include tubular diaphragms in which the premolded shape comprises a mechanical closure point. Embodiments include tubular diaphragms in which the premolded shape comprises a convolution area on at least one side of the tubular diaphragm. Embodiments also include tubular diaphragms in which the premolded shape comprises at least one side of the tubular diaphragm having a concave or convex shape.
[0004] Embodiments include the method of manufacturing of a tubular diaphragm having an enhanced lifetime comprises the step of molding the tubular diaphragm to include a preformed concave or convex shape on at least one side of the tubular diaphragm. Embodiments include the method of molding the tubular diaphragm to include a preformed convolution on at least one side of the tubular diaphragm. Embodiments include the method of molding a preformed mechanical closure point which approximates a tubular diaphragm in the closed position.
[0005] Embodiments include a tubular diaphragm which comprises a cylindrical tube manufactured of resilient elastomer with walls of approximately constant thickness throughout, an inlet flange and an outlet flange at the ends of the tube, and the tube having an upper and a lower side. There is a preformed mechanical closure point in which the inner surfaces of the upper and lower sides are separated by a gap of not greater than ⅓ of the diameter of the tube, the mechanical closure point located approximately at the middle of the length of the tubular diaphragm and dividing the diaphragm into an inlet and a outlet portion. There are preformed convolution areas on the upper and lower sides of at least one of the inlet and outlet portions, the convolution area located adjacent to a flange and extending in length from to about 25% of the length of a side and, in width to about 33% of the width of a side, the convolution areas having a concave or a convex form when viewed from the side of the tubular diaphragm.
[0006] Embodiments are used in the same manner as conventional cylindrical diaphragms. In operation of both conventional and embodiments of this disclosure, the outlet portion is subjected to a vacuum. The inlet is subject to the pressure of fluid at or above atmospheric pressure. The diaphragm is enclosed in a chamber. The valve remains closed when there is atmospheric pressure inside the chamber. Reduction of pressure inside the chamber allows the diaphragm to open and assume an approximately cylindrical cross-section throughout the diaphragm, and allows the fluid at the inlet portion to flow through the diaphragm through the outlet section.
[0007] Conventional cylindrical diaphragms are subject to fatigue failure, especially in the outlet portion of the diaphragm, because the valve is in the closed position for most of its life, and the outlet portion of the diaphragm is subject the greatest pressure differential with respect to the chamber.
[0008] Embodiments of the present disclosure are highly resistant to fatigue failure and enjoy a substantially longer operational life than do conventional cylindrical diaphragms. Without being held to this explanation, the longer life of these embodiments is due to the mechanical closure point which is molded to approximate a closed preformed position. In embodiments, the movement of the top and bottom sides necessary to effect closure is minimized, as compared to conventional cylindrical diaphragms. In addition, the optional convolution areas on the top and bottom sides, and the optional shaped sides contribute to extended life in embodiments. Such tubular diaphragms are subject to lower stresses than conventional cylindrical diaphragms.
[0009] The following embodiments and aspects thereof are described and illustrated in conjunction with embodiments which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
[0010] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0011] FIG. 1A is a perspective view of the first embodiment tubular diaphragm in the rest position.
[0012] FIG. 1B is a side view of the first embodiment tubular diaphragm in the rest position.
[0013] FIG. 1C is a upper view of the first embodiment tubular diaphragm in the rest position.
[0014] FIG. 1D is an end view of the first embodiment tubular diaphragm in the rest position.
[0015] FIG. 2 is a side view of the second embodiment tubular diaphragm in the rest position.
[0016] FIG. 3 is a side view of the third embodiment tubular diaphragm in the rest position.
[0017] FIG. 4 is a side view of the fourth embodiment tubular diaphragm in the rest position.
[0018] FIG. 5 is a side view of the fifth embodiment tubular diaphragm in the rest position.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In this disclosure the term “tubular diaphragm” means a preshaped cylindrical elastomeric tube used in a valve. The valve is installed in a fluid transportation system. The term “fluid” means liquids, gasses, or emulsions. The term “waste” means an unwanted fluid, as, for example, from toilets, sinks, grease traps, etc. The term “rest position” means the tubular diaphragm not installed in a chamber and not subjected to a vacuum. Although the words “inlet” and “outlet” are used in the descriptions of the embodiments, these words are used simply to facilitate descriptions and not to limit the use of the embodiments. It is specifically contemplated that embodiments may be used with the “inlet” side on the lower pressure side and with the “outlet” side on the higher pressure side.
First Embodiment
[0020] FIG. 1A is a perspective view of the first embodiment tubular diaphragm 100 in the rest position. Visible in FIG. 1A is the inlet flange 103 located at a first end 101 of the tubular diaphragm, the upper side 115 of the tubular diaphragm, which is divided into the upper outlet side 113 and the upper inlet side 111 by the mechanical closure point 124 at approximately the middle of the upper side 115 . The mechanical closure point 124 divides the entire tubular diaphragm into the inlet portion 121 and the outlet portion 123 .
[0021] The mechanical closure point 124 is preformed during the manufacturing process such that the upper interior surface 131 (in FIG. 1D ) and lower interior surface 131 (in FIG. 1D ) are not touching but are separated by a distance not larger then ⅓ of the diameter of the tubular diaphragm.
[0022] Also visible in FIG. 1A is the inlet portion upper convolution area 122 and the outlet flange 107 located at the second end 102 of the tubular diaphragm. The convolution area extends approximately from the flange to about 25% of the length of the upper inlet side 111 . The convolution area extends in width to about 33% of the width of the upper inlet side 111 . A similar convolution area exists on the lower side of the tubular diaphragm and is shown in FIG. 1B .
[0023] FIG. 1B is a side view of the first embodiment tubular diaphragm in the rest position. Visible in FIG. 1B is the inlet flange 103 , outlet flange 107 , the upper side 115 , and lower side 116 , both of which are divided by the mechanical closure point 124 at approximately the middle of the upper and lower sides into the upper outlet side 113 and upper inlet side 111 , and lower outlet side 125 and lower inlet side 127 , respectively. The mechanical closure point 124 also divides the entire tubular diaphragm into the inlet portion 121 and outlet portion 123 . Also visible in FIG. 1B is the inlet portion upper convolution area 122 and the inlet portion lower convolution area 128 .
[0024] In the first embodiment as shown in FIG. 1B the inlet portion upper convolution area 122 extends from the inlet flange 103 at an approximate right angle and then curves downward to the upper inlet side 121 which extends in a straight line to the mechanical closure point 124 . The inlet portion lower convolution area 128 extends from the inlet flange 103 at an approximate right angle and then curves upward to the lower inlet side 127 which extends in a straight line to the mechanical closure point 124 .
[0025] The outlet portion upper outlet side 113 extends from the outlet flange 107 in a concave curve which is continued by the upper outlet side 113 to the mechanical closure point 124 . The outlet portion lower outlet side 125 extends from the outlet flange 107 in a concave curve which is continued by the lower outlet side 125 to the mechanical closure point 124 .
[0026] FIG. 1C is a upper view of the first embodiment tubular diaphragm in the rest position. Visible in FIG. 1C is the inlet flange 103 , the upper side 115 of the tubular diaphragm, which is divided into the upper outlet side 113 and the upper inlet side 111 by the mechanical closure point at approximately the middle of the upper side 115 . Also visible in FIG. 1C is the inlet portion upper convolution area 122 and the outlet flange 107 . The convolution area extends approximately from the flange to about 25% of the length of the upper inlet side 111 . The convolution area extends in width to about 33% of the width of the upper inlet side. A similar convolution area exists on the lower side of the tubular diaphragm and is shown in FIG. 1B .
[0027] FIG. 1D is an end view of the first embodiment tubular diaphragm in the rest position. Visible in FIG. 1D is the inlet flange 103 , the inner surface 131 of the upper side 115 and the inner surface 132 of the lower side 116 , and the mechanical closure point 124 , where the interior surfaces 131 and 132 of the upper side 115 and lower side 116 , respectively, touch when the valve is closed. In the rest position, as shown in FIG. 1D , the inner surfaces of the walls are separated by a distance of less than about one third of the diameter of the tubular diaphragm.
Second Through Fifth Embodiments
[0028] The second through fifth embodiments are like the first embodiment in the perspective view, upper view, and end view. Differences in the second through fifth embodiments from each other and from the first embodiment are shown in the side views, FIGS. 2-5 .
Second Embodiment
[0029] FIG. 2 is a side view of the second embodiment tubular diaphragm in the rest position. Visible in FIG. 2 is the inlet flange 203 , outlet flange 207 , the upper side 215 , and the lower side 216 , both of which are divided by the mechanical closure point 224 at approximately the middle of the upper and lower sides into the upper outlet side 213 and upper inlet side 211 , and lower outlet side 225 and lower inlet side 227 , respectively. The mechanical closure point 224 also divides the entire tubular diaphragm into the inlet portion 221 and outlet portion 223 . Also visible in FIG. 2 is the inlet portion upper convolution area 222 and the inlet portion lower convolution area 228 .
[0030] In the second embodiment as shown in FIG. 2 the inlet portion upper convolution area 222 extends from the inlet flange 203 as a convex bump which then curves downward to the upper inlet side 221 which extends in a straight line to the mechanical closure point 224 . The inlet portion lower convolution area 228 extends from the inlet flange 203 as a convex bump and then curves upward to the lower inlet side 227 which extends in a straight line to the mechanical closure point 224 .
[0031] The outlet portion upper convolution area 220 extends from the outlet flange 207 as a convex bump which then curves downward to the upper outlet side 213 which then curves downward to the mechanical closure point 224 . The outlet portion lower convolution area 226 extends from the outlet flange 207 as a convex bump and then curves upward to the lower inlet side 225 which extends in a straight line to the mechanical closure point 224 .
Third Embodiment
[0032] FIG. 3 is a side view of the third embodiment tubular diaphragm in the rest position. Visible in FIG. 3 is the inlet flange 303 , outlet flange 307 , the upper side 315 , and lower side 316 , both of which are divided by the mechanical closure point 324 at approximately the middle of the upper and lower sides into the upper outlet side 313 and upper inlet side 311 , and lower outlet side 325 and lower inlet side 327 , respectively. The mechanical closure point 324 also divides the entire tubular diaphragm into the inlet portion 321 and outlet portion 323 . Also visible in FIG. 3 is the inlet portion upper convolution area 322 and the inlet portion lower convolution area 328 .
[0033] In the third embodiment as shown in FIG. 3 the inlet portion upper convolution area 322 extends from the inlet flange 303 as a concavity and then curves downward to the upper inlet side 321 which extends in a straight line to the mechanical closure point 324 . The inlet portion lower convolution area 328 extends from the inlet flange 303 as a concavity and then curves upward to the lower inlet side 327 which extends in a straight line to the mechanical closure point 324 .
[0034] The outlet portion upper convolution area 320 extends from the outlet flange 307 as a concavity and then curves downward to the upper inlet side 313 which extends in a straight line to the mechanical closure point 324 . The outlet portion lower convolution area 326 extends from the outlet flange 307 as a concavity and then curves upward t the lower outlet side 325 which extends in a straight line to the mechanical closure point 324 .
Fourth Embodiment
[0035] FIG. 4 is a side view of the fourth embodiment tubular diaphragm in the rest position. Visible in FIG. 4 is the inlet flange 403 , outlet flange 407 , the upper side 415 , and lower side 416 , both of which are divided by the mechanical closure point 424 at approximately the middle of the upper and lower sides into the upper outlet side 413 and upper inlet side 411 , and lower outlet side 425 and lower inlet side 427 , respectively. The mechanical closure point 424 also divides the entire tubular diaphragm into the inlet portion 421 and outlet portion 423 . Also visible in FIG. 4 is the inlet portion upper convolution area 422 and the inlet portion lower convolution area 428 . In the fourth embodiment as shown in FIG. 4 the inlet portion upper convolution area 422 extends from the inlet flange 403 as a concavity and then curves downward to the upper inlet side 421 which extends in a straight line to the mechanical closure point 424 . The inlet portion lower convolution area 428 extends from the inlet flange 403 as a concavity and then curves upward to the lower inlet side 427 which extends in a straight line to the mechanical closure point 424 . The outlet portion upper convolution area 420 extends from the outlet flange 407 as a convex bump which then curves downward to the upper outlet side 413 which extends in a straight line to the mechanical closure point 424 . The outlet portion lower convolution area 426 extends from the outlet flange 407 as a convex bump and then curves upward to the lower inlet side 425 which extends in a straight line to the mechanical closure point 424 .
Fifth Embodiment
[0036] FIG. 5 is a side view of the fifth embodiment tubular diaphragm in the rest position. Visible in FIG. 5 is the inlet flange 503 , outlet flange 507 , the upper side 515 , and lower side 516 , both of which are divided by the mechanical closure point 524 at approximately the middle of the upper and lower sides into the upper outlet side 513 and upper inlet side 511 , and lower outlet side 525 and lower inlet side 527 , respectively. The mechanical closure point 524 also divides the entire tubular diaphragm into the inlet portion 521 and outlet portion 523 . Also visible in FIG. 5 is the inlet portion upper convolution area 522 and the inlet portion lower convolution area 528 .
[0037] In the fifth embodiment as shown in FIG. 5 the inlet portion upper convolution area 522 extends from the inlet flange 503 at an approximate right angle and then curves downward to the upper inlet side 521 which extends in a straight line to the mechanical closure point 524 . The inlet portion lower convolution area 528 extends from the inlet flange 503 at an approximate right angle and then curves upward to the lower inlet side 527 which extends in a straight line to the mechanical closure point 524 .
[0038] The outlet portion upper convolution area 520 extends from the outlet flange 507 on a downward straight line which is continued by the upper outlet side 513 to the mechanical closure point 524 . The outlet portion lower convolution area 526 extends from the outlet flange 507 on an upward straight line which is continued by the lower outlet side 525 to the mechanical closure point 524 .
General
[0039] In embodiments, the diameter of the tubular diaphragm ranges from ½ inch to 12 inches. In embodiments, the length of the tubular diaphragm will range from 3 inches to 36 inches.
[0040] Embodiment tubular diaphragms are manufactured of any suitable resilient polymeric material. Suitable materials include natural rubber, polypropylene, polyethylene, polyvinylidene fluoride, nitrile rubber, ethylene propylene diene monomer rubber, butyl rubber, vinylidene fluoride monomer fluoroelastomers, silicone rubber, fluorinated ethylene propylene, perfluoroalkoxy, and polytetrafluoroethylene. Nitrile rubber, ethylene propylene diene monomer rubber, and butyl rubber are especially suitable.
[0041] Embodiments may be manufactured by any suitable method. Methods of manufacture include injection molding, and extrusion. Compression molding, transfer molding or injection molding are especially suitable methods.
[0042] In embodiments, optional tethers are attached on either side of the mechanical closure point. Such tethers interact with and slide into guides which assist the complete opening of the tubular diaphragm.
[0043] Although examples in this disclosure include the use of embodiments in the operation of vacuum toilets, it is specifically contemplated that the embodiment tubular diaphragms will find utility in other applications in the movement of fluids when there is a pressure differential between the inlet and outlet of the tubular diaphragms.
[0044] Embodiment tubular diaphragms exhibit in particular the advantage of enhanced resistance to failure when compared to conventional cylindrical diaphragms. This resistance is expressed especially in the outlet portion, which is subject to the maximum pressure differential when the tubular diaphragm is closed, which is the normal condition.
[0045] Without wishing to be held to this explanation, the enhanced resistance of embodiments stems from the fact that the premolded mechanical closure point minimizes the flexation of the tubular diaphragm required when it is in the closed position. In particular, since the tubular diaphragm is in the closed position for the vast majority of time it is in use, the premolded mechanical closure point which approximates the closed position minimizes the stress involved in putting the tubular diaphragm in the closed position.
[0046] In addition, the convolution areas or the interaction of convolution areas and sides adds to the lifetime of the tubular diaphragms. The convolution areas relieve stresses normally on the tubular diaphragms. The effect of the convolution areas and the shape of the sides enhance the advantages provided by the preformed mechanical closure point.
[0047] Advantages from the extended life of embodiments include reduction of the cost of replacement valves, reduction of the labor required to replace worn-out valves, and avoidance of capital costs associated with redundant facilities needed when valves fail.
[0048] In embodiments, a tubular diaphragm is normally in the closed position and is opened only when desired. A variety of opening mechanisms can be used. A vacuum mechanism is commonly used, in which the tubular diaphragm is enclosed in a chamber while the atmospheric air pressure and spring pressure maintains the tubular diaphragm in the closed position. The tubular diaphragm is opened when air is evacuated from the chamber. The opening of the tubular diaphragm may be assisted by mechanical means attached to tethers located at the mechanical closure point. Other means of operating the tubular diaphragms are contemplated.
[0049] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. The applicant or applicants have attempted to disclose all the embodiments of the invention that could be reasonably foreseen. There may be unforeseeable insubstantial modifications that remain as equivalents. | Embodiments include tubular diaphragm valves with a preformed mechanical closure point and optionally concave or convex convolution areas located near the flanges. These mechanical closure points and convolution areas give the embodiments an extended operational life, as compared to that of conventional cylindrical diaphragms. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to drilling apparatus, and, in particular, to apparatus for use in drilling underground, e.g. drilling under highways for the purpose of installing components such as cables, ducts and pipes.
It is known to use a process called "directional drilling" to install services in sensitive areas where open cut techniques cannot be used such as under runways, motorways, rivers and railways. A small diameter hole is first bored under the crossing using a boring head and drill string made up of steel tubes through which a bentonite slurry known as "Mud" is pumped at high pressure. The boring head is then replaced with a back reamer behind which is connected, via a swivel, the plastic pipe (or other component) to be installed. The drill string is then rotated and pulled back, whilst mud is again pumped through the rods and out of jets in the reamer. The rotating reamer enlarges the hole, whilst the mud cools it and stabilises the opening. The pipe is thus pulled back under the crossing. If, however, the swivel seizes up, the plastic pipe is wound up and irreparably damaged, and the crossing is abandoned, wasting costly time and materials.
A conventional swivel has a tubular body portion into which a swivel shaft extends, there being a bearing to facilitate relative rotation. There is a lip seal intended to exclude mud and other debris from the, bearing. Grease is normally pumped into the swivel before each shot, but because the seal is orientated to keep mud out rather than grease in, this tends to lift the lip of the seal off the swivel shaft and allow ingress of grit. The seal immediately starts to deteriorate and allows more debris to pass. When this reaches the bearing, the eventual destruction of the bearing, and hence the swivel, is inevitable. Common practice is to throw swivels away and replace them before they fail. Thus, an improved sealing arrangement is desirable.
The bearings are also subject to large forces. In order to make them better able to stand up to the forces, larger bearings may be used. But this requires larger housing spaces to be provided in the swivel devices, leading to many practical problems. It is also known to use two or more angular contact bearings, stacked one behind another along the swivel shaft, with a backing nut behind the last one. But this is not very effective.
SUMMARY OF THE INVENTION
In one aspect the invention provides a swivel device for use in drilling apparatus, said device comprising a tubular body portion; a swivel shaft which extends into the tubular body portion; a bearing assembly interposed between the shaft and the body portion to facilitate relative rotation; and a seal assembly for resisting ingress of mud into the space between the shaft and the body portion; said seal assembly comprising an O-ring surrounding the shaft, and means for supplying grease to both axial sides of the O-ring. Thus there may be a grease supply path leading to a first grease chamber at a first axial side of the O-ring; a second grease chamber at the second axial side; and a duct for communicating grease to the second chamber. There may be non-return means for resisting backflow of grease from the second chamber. There may be a second O-ring axially beyond the second chamber, and a third chamber axially beyond the second O-ring, with a duct for supplying grease, e.g. from the second chamber.
Preferably, the bearing assembly comprises a double taper (opposed) roller bearing. The swivel will therefore operate equally well in compression as in tension; e.g. if the drill string is "backed up".
In a second aspect the invention provides a swivel device for use in drilling apparatus, said device comprising a tubular body portion; a swivel shaft which extends into the tubular body portion; a bearing assembly interposed between the shaft and the body portion to facilitate relative rotation; and a seal assembly for resisting ingress of mud into the space between the shaft and the body portion; said bearing assembly comprising two thrust bearings mounted on the swivel shaft at axially spaced regions thereof, each thrust bearing being individually locked in place. Preferably, each of the thrust bearings is locked in place by means of a respective locking assembly mounted on the swivel shaft. A locking assembly may comprise a thrust nut and a locking nut or washer. When assembling the device the bearings can be individually pretensioned and locked up.
Preferred embodiments incorporate both the first and second aspect.
In a third aspect the invention provides drilling apparatus comprising a drill component such as a back reamer, and a swivel device connected thereto.
In a fourth aspect the invention provides a method of drilling.
Some embodiments of the invention will now be described in more detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial section of a swivel device which is a first embodiment of the invention;
FIG. 2 is a detail of part of the seal assembly of the first embodiment;
FIGS. 3 and 4 are axial sections through second and third embodiments;
FIGS. 5 and 6 are end elevations of sealing rings; and
FIGS. 7-9 are axial sections of further embodiments;
FIG. 10 is a perspective view of the embodiment shown in FIG. 8, partially cut away;
FIG. 11 is a schematic view of the invention in use.
FIG. 11a is a blow-up of a portion of the invention shown in FIG. 11 identified by 11a.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The swivel device shown in FIG. 1 has a swivel shaft 1, body 2, and a cap 3 all suitably made of high tensile steel, e.g. EN24T. The body 2 is tubular with an inwardly protruding flange 2a at an intermediate region. The inner portion of the body 2 has an internal thread 2b. The shaft 1 has an outer portion 1a of similar external diameter to the body 2, and a reduced portion 1b that extends through the body 2, projecting beyond its inner end. The reduced portion 1b is mainly a rod 1c of uniform diameter but, between this and the outer portion 1a, there is a seal zone 1d of more complex shape for providing, together with the body 2, a series of chambers and cavities, which will be described later. The inner end portion of the rod 1c is threaded.
The cap 3 has a main portion 3a of similar external diameter to the body 2, and a reduced shank portion 3b having an external thread engageable with the internal thread 2b of the body. An O-ring 8 provides a seal between the body and the cap adjacent the start of the cap's reduced portion 3b. The cap 3 is partially tubular, opening towards the body 2. The outer portion of the swivel shaft 1 and cap 3 (remote from the body 2) are similar, with spaced arms 1e, 3c, bridged by clevis pins 7 of hard material, e.g. heat-treated high tensile steel. The cap has an axial passage extending from the outer region between the arms 3c to the tubular interior. This houses a grease nipple 12.
A sealed-for-life double taper roller bearing 4 is an annular unit located within the body 2, slightly spaced from the flange 2a by a radial bearing chamber 9. It embraces the rod 1c and abuts a step at the start of the seal zone 1d. On the other side of the flange 2a, the rod 1c is embraced by a thrust bearing 5. A thrust nut 6 is screwed onto the threaded end of the rod to hold the bearing 5 against the flange 2a.
In the seal zone 1d, starting from the rod 1c, there is a first radial step defining a first chamber 13 followed by a main portion whose diameter is only slightly less than the internal diameter of the body but having a first annular recess 1f housing a first shaft seal O-ring 10, a second annular recess 1g similar to the first and housing a second shaft seal O-ring 11 and, intermediate these recesses, a deeper and narrower intermediate recess defining a second chamber 16 which also extends radially outwardly into a recess 2c in the body. Beyond the second annular recess 1g there is a third chamber 20, in this case produced by thinning of the body 2. A pair of ducts 14, 15 communicate the first chamber with a radially inner region of the second chamber 16. A second pair of and 19 which extend within the thickness of the body 2 communicate a radially outer region of the second chamber with the third chamber. A detail of the lower region of the second chamber 16 is shown in FIG. 2. The lower region narrows downwardly to opposed steps 16a leading to a narrow innermost region 16b into which the first ducts 14,15 open. An O-ring 17 is located as shown, the surfaces of the steps providing a sealing surface. The resilience of the ring 17 pulls it into sealing engagement, but it is displaceable outwardly by pressure from the innermost region 16b.
In use, the swivel 1 is supported by the radial bearing 4 in the body 2. The thrust is taken by the thrust bearing 5 and the thrust nut 6. The cap 3 is sealed to the body 2 by means of the `O` ring 8. Silicone grease, highly resistant to washout, is pumped into the assembly via the grease nipple 12.
The flow is from right to left and the grease progressively fills the thrust bearing chamber. It is then forced through into the radial bearing chamber 9, past the bearing into the first chamber 13. (NB the bearing 4 is sealed-for-life.)
The grease then flows through the first two fine ducts 14,15 into the second chamber 16. The `O` ring 17 in the second chamber 16 seals on the tapering sides of chamber 16 forming a non return valve. Grease forced through the first pair of ducts 15,16 lifts the `O` ring off its seat, the grease passes, then the `O` ring contracts onto its seal and seals, thus preventing return of possibly contaminated grease.
The grease is bled through the second pair of fine ducts 18,19 into the third chamber 20, and hence to atmosphere.
As mud tries to penetrate, it is resisted initially by the grease packed into the third chamber 20. Its further penetration is prevented by `O` rings 11,10. The `O` rings are lubricated and extra protection from mud is provided by the grease chambers 16 and 13. In the unlikely event that mud passes through the second ducts 18,19 it is prevented from passing onwards through the first ducts 14,15 by the non-return valve formed by the O-ring 17 in the second chamber 16.
Any ingress of mud can be flushed out by pumping in fresh grease before each use and the bearings will be protected indefinitely.
FIGS. 3 and 4 show further embodiments, differing in some details from the first embodiment. Thus the third chamber 20 contains a sealing ring 120. (This could also be provided in the first embodiment.) This preferably has a "quadrate" cross-section which is basically square with concavities on the faces. Such rings are commercially available e.g. under the names NU-LIP (from Pioneer) and QUAD. Examples of such rings are shown in FIGS. 5 and 6. FIG. 5 shows a ring 120 whose cross-section is a square with arcuate recesses 122 in each face. FIG. 6 shows a ring 120' that differs from that of FIG. 5 in having fine paraxial ducts 124 extending between the middle of axially opposite faces. There may be four such ducts, at 90° intervals.
A ring (120 or 120') in the third chamber 20 helps to retain grease in the chamber and prevent it from bleeding to atmosphere too readily. It seals on the opposed radially inner and outer walls of the chamber. A ring 120' with fine ducts 124 facilitates the escape of air as the device is charged with grease.
FIGS. 3 and 4 also show alternative bearing arrangements. Instead of the sealed-for-life double taper roller bearing 4 of the first embodiment, FIG. 3 shows an axially spaced pair of roller thrust bearings 104 and, between them, a pair of needle roller bearings 105. The inner wall of the tubular body 102 is shaped to accommodate them. Thus there is a portion 106 of reduced diameter with a recess 107 at each end for accommodating the needle roller bearings 105. From the outer ends of the recesses there are steps 108 against which the roller thrust bearings 104 abut.
FIG. 4 shows a similar arrangement but using one taper roller bearing 204 and one spherical taper roller bearing 204' instead of the pair of roller thrust bearings. There may be only a single needle roller bearing 205, adjacent the spherical taper roller bearing 204'.
FIG. 7 shows another embodiment, in which the bearings are two taper roller bearings 304, 304' arranged in opposition either side of the body flange 302a. The tapers are at steep angles to the axis. As in the FIG. 3 embodiment, there are three O-rings 310, 311, 320 sealing between the swivel shaft and the tubular body. In this example all are of "quadrate" section.
FIG. 8 shows another embodiment using three taper roller bearings 403,404 and 404', and two thrust nuts 405 and 405'. On assembly the inner thrust nut 405 is adjusted to bear on the inner thrust bearing 404 and locked to the shaft 1 by means of a threaded lock washer 406 and cap head screws 407 (6 in number in this example). (When separated by a quarter turn, the combination of the nut and threaded washer 406 clamp on the thread like a conventional split nut.) A spacer 408 is then introduced into the body and bears on the cup of the inner bearing 404. The outer thrust bearing 404' is then secured in place by adjusting the thrust nut 405' hard against it and locking it using a threaded washer 406' and a further set (here 6) of cap head screws 407'.
In this configuration the load on the swivel is shared equally on the two thrust bearings 404 and 404' thus increasing the life of each by a factor of up to 10. The load on the outer thrust bearing 404' is transmitted via the spacer 408 to the cup of bearing 404 and thence to the flange in the body 2a. In the event of one thrust bearing failing the second thrust bearing will prevent seizure of the swivel and allow satisfactory completion of the drilling operation when the bearings can be replaced.
FIG. 9 shows a configuration of bearings suitable for larger sizes of swivels utilizing two taper roller bearings 503, 504 and one spherical taper roller bearing 505. In this variation the shaft 1 has a step 1' to accommodate the smaller bore size of the bearing 504, and the thrust nut 507 has a tubular portion 507' extending axially into the bearing to accommodate its larger bore size and thereby centralise the bearing and support the shaft.
The spacer 508 is supported by a step 509 in the body 2. Thus the load taken by the bearing 505 is transmitted via the spacer directly to the body, not via the cup of bearing 504. As in the previous embodiment (FIG. 8) the thrust nuts are again locked to the shaft using threaded washers and cap head screws.
The load on the swivel is again shared between the two bearings 504 and 505.
While the invention has been described and exemplified with reference to particular examples, it will be appreciated that modification and variation is possible within the spirit and scope of the invention. It is intended to include all such modifications and variations within the scope of the appended claims. | A swivel device for coupling a back reamer to a plastic pipe to be drawn through a hole has a swivel shaft that extends into a tubular body and engages a bearing. At one side of the bearing an O-ring seals between the shaft and the body. A grease supply path extends past the bearing to a grease chamber on the bearing side of the O-ring and thence via a duct, to a grease chamber on the other side of the O-ring. | 4 |
DESCRIPTION
Field of the Invention
This invention is in the field of vacuum sputter coating apparatus and particularly relates to a magnetron sputter source for such apparatus.
Background of the Invention
Vacuum deposition of coatings is in widespread use today, and appears to be of growing importance in the future. Cathode sputtering induced by glow discharges is emerging as one of the more important processes for effecting such depositions. Much of the recent work relates to various magnetron geometries in which enhanced sputtering rates and operation at lower pressures are achieved through judicious use of magnetic fields. An extensive literature has developed and many patents have issued over the past decade. A particularly informative and reasonably current summary is contained in the book "Thin Film Processes" edited by John L. Vossen and Werner Kern, published by Academic Press, New York, 1978. Particularly relevant chapters are: Chapter II-1, "Glow Discharge Sputter Deposition", by J. L. Vossen and J. J. Cuomo; Chapter II-2, "Cylindrical Magnetron Sputtering", by John A. Thronton and Alan S. Penfold; Chapter II-3, "The Sputter and S-Gun Magnetrons", by David B. Fraser; and Chapter II-4, "Planar Magnetron Sputtering" by Robert K. Waits.
In order for the intensity of glow discharges to be enhanced through the application of magnetic fields, it is necessary that electrode geometries, magnetic field intensities, and magnetic field geometries be selected in such a way as to produce electron traps. In most cases, crossed electric and magnetic fields give rise to electron drift currents which close on themselves. In the case of cylindrical magnetrons, for example, radial electron traps can be formed with essentially uniform magnetic fields parallel to the axes of the cathode and anode cylinders. By providing the cathode with electron reflecting surfaces at its ends, loss of electrons from the discharge through axial drift can be reduced, thus further enhancing the discharge intensity, and making operation at lower gas pressures possible. (See, for example, above-referenced Chapter II-2, "Cylindrical Magnetron Sputtering", by John A. Thornton and Alan S. Penfold, especially pp. 77-88.)
In many of the magnetrons employed commercially for sputter deposition, electron trapping is accomplished by shaping the magnetic field relative to the shape of the sputter target (cathode). In particular, most planar magnetrons employ a magnetic field which loops through the planar cathode surface and which forms a tunnel-shaped magnetic field which closes on itself. (See, for example, above-referenced Chapter II-4, "Planar Magnetron Sputtering", by Robert K. Waits, especially page 132.) Under normal operating conditions, the glow discharge is largely confined to this magnetic tunnel.
Magnetic tunnels are also employed with nonplanar magnetron configurations. An example of a hollow cathode cylindrical magnetron employing a single magnetic tunnel is shown in FIG. 4, p. 118 of above-referenced Chapter II-3, "The Sputter and S-Gun Magnetrons", by David B. Fraser. In addition, examples of cylindrical magnetrons employing multiple magnetic tunnels are shown in FIG. 3., p. 78 of above-referenced Chapter II-2.
Another circular magnetron sputter source in commercial use employs a cathode (target) of a generally inverted conical configuration surrounding an axially symmetric central anode. An example of such a sputter source may be found described in more detail in U.S. Pat. No. 4,100,055, issued July 11, 1978 to Robert M. Rainey and entitled "Target Profile for Sputtering Apparatus" and assigned to the assignee of the present invention. Such a sputter source is also commercially available from and manufactured by Varian Associates, Inc. under the trademark "S-Gun". This type of sputter source is also described, for example, in above-referenced Chapter II-3, especially FIG. 1, p. 116 and FIG. 3, p. 117. In particular, FIG. 3, p. 117 shows schematically the magnetic field looping through the conical cathode (target) surface to form a magnetic tunnel which confines the glow discharge.
In prior art magnetic tunnels, the energetic electrons which sustain the glow discharge would need to cross magnetic field lines to escape from the magnetic tunnel, which they are unable to do if the magnetic field intensities are great enough. Also, those electrons which have been captured into the discharge are energetically incapable of reaching the cathode. Thus, even though these electrons may follow magnetic field lines toward the cathode surface, they will be electrostatically reflected from the cathode surface back into the discharge.
If the magnetic field intensity falls off with distance from the cathode surface, as it does in most prior art magnetic tunnels, "magnetic mirroring" can also contribute to electron reflection. The main effect of such magnetic mirroring is, on average, to move the region of electron reflection a bit further from the cathode surface. This effect is incidental rather than crucial to the magnetic tunnel's role in reflecting electrons in order to contain the glow discharge. In any event, those electrons which would otherwise escape through the magnetic mirror will be reflected electrostatically back into the discharge. It is therefore both convenient and proper to refer to the electron reflection in the prior art simply as "electrostatic", even though some magnetic mirroring may be occurring.
Discharge intensity tends to be a maximum in the center of a magnetic tunnel, where the magnetic field lines are generally parallel to the cathode surface, and falls off rapidly as the sides of the magnetic tunnel are approached. Localized cathode (target) erosion rates correspond generally with the immediately adjacent intensity of the glow discharge, thus leading to nonuniform erosion of the cathode surface. Examples of nonuniform erosion of an S-Gun cathode are shown in FIG. 3 of above-referenced U.S. Pat. No. 4,100,055 to Rainey, and examples in the case of planar magnetron cathodes are shown in FIG. 5, p. 141 of above-referenced Chapter II-4.
One consequence of nonuniform cathode erosion is that there is less-than-maximum utilization of target material. Another consequence of nonuniform cathode erosion is that changes may occur in the distribution pattern of sputtered material leaving the cathode surface. Additionally, the glow discharge tends to move downward in the magnetic tunnel to maintain close proximity to the cathode surface as the cathode surface erodes away. This movement when coupled with nonuniform cathode erosion tends to concentrate the discharge even more sharply, leading to still greater nonuniformity of cathode erosion. Furthermore, such nonuniform cathode erosion restricts the area of emission of sputtered atoms to a relatively narrow band on the cathode surface. This in turn restricts the range of direction of sputtered atoms arriving at the substrate to be coated, thus affecting such film properties as uniformity and step coverage, both of which are of particular importance in metalization of semiconductor wafers, for example. Also, the deposition rate from a deeply eroded cathode may be reduced because of geometrical shielding effects. In addition, nonuniform cathode erosion is attended by correspondingly nonuniform cathode heating, which contributes adversely both to cathode cooling problems and to thermal stressing of the cathode.
Using prior art magnetic tunnels, a further consequence of the movement of the glow discharge with erosion of the cathode surface is that the discharge generally moves into a region of greater magnetic field intensity. This results in a lowering of the discharge impedance, which requires lower operating voltage, higher discharge current, and higher discharge power to maintain a fixed deposition rate (see above-referenced Chapter II-2, pp. 94-98; also see above-referenced Chapter II-3, pp. 117-121). An indication of the severity of this problem in some applications is conveyed by U.S. Pat. No. 4,166,783 issued Sept. 4, 1979 to Federick T. Turner and entitled "Deposition Rate Regulation by Computer Control of Sputtering Systems" and assigned to the assignee of the present invention.
Accordingly, it is an object of the invention to provide a glow discharge sputter source in which input power can be maintained constant throughout cathode (target) life for constant deposition rate.
Another object of the invention is to provide a sputter source which operates with higher sputtering efficiency, whereby power consumption and power supply size are reduced.
Another object of the invention is to provide a sputter source in which the electrical impedance of the glow discharge remains substantially constant throughout cathode (target) life, whereby the problems of supplying and controlling power are reduced.
A further object of the invention is to increase the utilization of target material, thereby increasing target life.
Yet another object of the invention is to maintain a more uniform distribution pattern of sputtered material leaving the cathode surface over the useful life of the cathode.
A further object of the invention is to increase the width of the band from which sputtered atoms are emitted from the cathode, whereby coatings having improved properties may be obtained.
A still further object of the invention is to ease the cathode cooling problem, thereby allowing operation at higher powers and at correspondingly greater sputter deposition rates.
Yet another object of the invention is to reduce thermal stressing of the cathode, whereby fracture, localized melting, and the like are avoided.
A further object of the invention is to provide an improved means for holding the cathode in place, whereby brittle and weak cathodes may be retained without breakage caused by the holding means.
A still further object is to reduce the amount of unused target material in the cathode.
SUMMARY OF THE INVENTION
In prior art magnetic tunnels as applied to sputter sources, the magnetic field loops through the cathode surface to confine the glow discharge within the magnetic tunnel. As discussed earlier, confinement of the discharge occurs because electrons are reflected electrostatically from the cathode surface back into the discharge. Such electrostatic reflection takes place on "both sides" of the magnetic tunnel.
In the preferred embodiment of the present invention, a modified magnetic tunnel is employed in which only a "first side" of the magnetic tunnel passes through the cathode surface. Confinement of the glow discharge on the "second side" is provided by a "magnetic mirror". Electron reflection thus occurs electrostatically from the cathode surface on the first side of the magnetic tunnel, whereas electrons are reflected by magnetic mirroring on the second side.
One feature of magnetic mirrors which is of particular importance in the present invention is that the mirrors are "soft" in the sense that the point of reflection is not a well defined physical surface, but depends on the ratio of parallel to perpendicular electron velocities relative to the direction of the magnetic field at some interior point. This "softness" of the magnetic mirrors is used to advantage in the present invention to produce a widening and a spreading out of the discharge toward the "magnetic mirror side" of the discharge. This contributes to a broader, less sharply concentrated cathode erosion pattern.
One consequence of using one or more magnetic mirrors is that it becomes possible to design magnetic tunnels which are much flatter, that is, much less sharply arching, than the prior art magnetic tunnels. This contributes to increased uniformity of cathode erosion, and can lead also to glow discharges whose electrical impedance at a fixed power level and operating pressure remains more constant as the cathode is eroded away. In certain applications this means that a much simpler control system can be used to obtain the desired deposition rate than has been possible heretofore with sputter sources employing prior art magnetic tunnels. It also means that less flexibility is required of the power supply, which leads to reductions in size and cost as compared with the power supplies required for prior art sputter sources employing magnetic tunnels.
Thus it is that the use of a magnetic tunnel employing one or more magnetic mirrors allows many of the objects of the present invention to be realized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial section of a sputter source incorporating the present invention in the preferred embodiment.
FIG. 2 is a section of a prior art sputter source.
FIG. 3 is a fragmentary section of the sputter source of FIG. 1 showing new and end-of-useful-life cathode profiles and showing also magnetic field lines and data.
FIG. 4 is a fragmentary section of the prior art sputter source of FIG. 2 showing new and end-of-useful-life cathode profiles and showing also magnetic field lines and data.
FIGS. 5a and 5b show normalized deposition rates as functions of cathode life in kilowatt-hours for the sputter sources of FIGS. 1 and 2 respectively.
FIGS. 6a and 6b show voltage-current curves with argon pressure as a parameter for the sputter sources of FIGS. 1 and 2 respectively.
FIG. 7a shows schematically magnetic field lines converging to form a magnetic mirror, together with representative electron trajectories.
FIG. 7b shows schematically the relative magnitude of the magnetic field intensity along a representative magnetic field line of FIG. 7a.
FIG. 8 is a fragmentary section of the sputter source of FIG. 1 showing in greater detail the cathode retaining means.
DETAILED DESCRIPTION
The preferred embodiment of the present invention is shown in FIG. 1 wherein the sputter coating source 1 is of generally circular configuration. A circular central anode 10 is surrounded by a circular cathode ring 12 having a front sputter surface 13 of generally inverted conical configuration from which material is to be sputtered. The ring member 12 is at negative potential relative to anode 10 during operation of the sputter coating source and thus is aptly termed a cathode. Ring member 12 also forms a target for bombardment by ions from the glow discharge and thus is also referred to in the art as a sputter target. Accordingly, ring 13 is referred to in various places in the description and claims alternatively as a cathode or a sputter target. The details of the cross sectional shape of the cathode (sputter target) 12 will be described hereinafter in respect to FIG. 8.
Anode 10 serves both as an electrical field forming electrode and as one end of the magnetic field-forming circuit. More specifically, anode 10 comprises a magnetic pole piece 15, and in order to facilitate insertion and removal of the cathode (as will be hereinafter described in detail), pole piece 15 preferably includes a removable annular ring portion 16. Also, a removable thin anode surface sheet in the form of inverted cup 17 is held in place by screws 18 (one shown). Anode surface sheet 17 can be magnetic or nonmagnetic material, but if nonmagnetic, it should be sufficiently thin to preserve the desired magnetic field strength at the anode surface. An annular member 20, made of nonmagnetic material, is attached by means of bolts 21 to pole piece 15. An inner O-ring groove 22 allows a vacuum tight seal to be made between annular member 20 and pole piece 15. Annular member 20 also contains outer O-ring groove 23 for sealing to the lower side of an electrical insulator ring 24 to insulate anode 10 from cathode 12. Anode 10 including pole piece 15 is cooled by passing coolant through a water channel 26 via coaxial conduits 27 and 28. An inverted cup-shaped magnetic member 30 is secured to pole piece 15 by means of bolts 31 (one shown). An O-ring groove 32 is provided in pole piece 15 to prevent coolant leakage between pole piece 15 and magnetic member 30. Annular magnets 33 provide the magnetic field for the magnetically enhanced sputter source. Because magnets 33 are located outside of the vacuum chamber, they need not be made of vacuum-compatible materials. Thus, for example, magnets 33 may be made of a barium ferrite permanent magnet material such as Indox 5. Alternatively, an annular electromagnet (not shown) may be used in combination with permanent magnets 33 to provide an electrically controllable portion of the magnetic field. Such electrical control of the magnetic field can be used to adjust the electrical impedance of the glow discharge, whereby, for example, changes in discharge impedance with cathode erosion can be compensated. In addition, a temporary increase in magnetic field can be advantageously used to trigger discharge initiation. Magnets 33 are placed on a magnetic base plate 34, onto which they are held by magnetic attraction. Adequate centering of magnets 33 is achieved through the use of a nonmagnetic cylinder 35 secured to flange 36, which is secured in turn to base plate 34 by screws 37 (one shown). A magnetic ring 38 is placed between magnetic member 30 and upper magnet 33. Magnetic members 30 and 38 and magnets 33 are held together by magnetic attraction.
Cathode 12 is secured, by novel means which are detailed later, to a nonmagnetic annular base member 40. Cathode 12 is also surrounded by nonmagnetic water jacket 41. Cathode 12 and water jacket 41 are so dimensioned that room temperature clearance between these members is large enough to allow easy installation and removal, yet small enough to provide adequate thermal contact for cathode cooling when the cathode expands upon heating during normal operation. Water jacket 41 is secured mechanically to base member 40 by means of a nonmagnetic ring member 42 held by screws 43 (one shown). Water jacket 41 has internal water channels 45 through which coolant, preferably water, is circulated via conduits 50 (one shown). Conduits 50 are brazed in sleeves 51 which are brazed in base member 40 to provide vacuum-tight sealing between conduits 50 and base member 40. Conduits 50 also comprise conventional detachable compression fittings 52 and 53 plus a bellows member 54, which is employed to reduce mechanical stress on the vacuum-tight sealing of conduits 50 to base member 40. Direct cooling of base member 40 is provided by water channel 56 through which coolant is circulated via conduits 57 (one shown). This cooling is of particular importance in preserving the vacuum integrity of the O-ring in an O-ring sealing groove 58 for sealing the upper side of anode insulator 24. Base member 40 also contains an O-ring sealing groove 55 for sealing to the lower side of an electrical insulator ring 59 for the cathode. Finally, base member 40 has secured to it, by tack welding for example, a cathode retainer ring 60 which is shown in greater detail in FIG. 8. A shield ring 61 has an outer lip portion which is sandwiched between the top of retainer ring 60 and cathode 12. The purpose of shield 61 is to reduce undesired coating of anode insulator 24 during sputter source operation. Retainer ring 60 contains a plurality of threaded holes, and shield 61 contains a plurality of corresponding clearance holes which are brought into registry during assembly.
As shown in greater detail of FIG. 8, cathode 12 contains an inner rim portion 62 including an annular groove having angled wall 63 which makes an acute angle of about 60° with the bottom or back surface 64 of cathode 12. The threaded holes in retaining ring 60 engage threaded members 65, which may be dog-point set screws, for example, or, alternatively, special screws incorporating spring-loaded ball plungers. Tightening threaded members 65 against angled wall 63 by inserting a tool through holes 66 in shield ring 61 provides positive retention of cathode 12 upon normal installation at room temperature. The number of threaded members 65 employed is preferably three. When cathode 12 expands upon heating during normal operation, it may expand away from threaded members 65. However, acutely angled wall 63 in cooperation with threaded members 65 serve to prevent cathode 12 from falling a significant distance away from base member 40 in case the sputter source is operated in an inverted position, for example. Moreover, thermal expansion of cathode 12 during normal operation tends to hold it securely in water jacket 41. Replacement of cathode 12 is accomplished by removing anode surface sheet 17 and annular ring portion 16 from pole piece 15, and then unscrewing threaded members 65 enough to release the cathode, which in turn releases shield ring 61 which is simply held in place by the presence of cathode 12.
As shown in detail in FIG. 8, cathode 12 has an outer surface or rim formed by a lower portion 67 and an upper surface portion 68 of larger diameter than the lower portion 67. The upper and lower portions are preferably joined by a sloping intermediate portion 69. The relative shaping and positioning of inner pole piece 15 and the hereinafter described outer pole piece 72 cooperates with the above-described shaping of the cathode 12 to obtain the desired magnetic field shape with respect to cathode 12. These relationships and resulting erosion pattern have also been found to permit the direct cooling of cathode 12 to be limited to the area of lower wall portion 67, as distinguished from having the outer surface of the cathode extend straight down from the large diameter outer portion 68. Thus the cathode shape in FIGS. 1 and 8 results in a smaller overall diameter for the sputter source 1 with attendant savings in cost of materials and space occupied by the source. The above relationships also result in the thick inner rim 62 on cathode 12 which permits use of the novel angled wall 63 and threaded members 65 for holding the cathode in place.
A housing 70 for the anode-cathode assembly comprises a lower ring member 71 and an outer magnetic pole piece ring 72 joined together in vacuum-tight fashion by a cylindrical wall member 73. Members 71 and 73 are made of ferromagnetic material, such as cold rolled steel, to provide portions of the required magnetic path to pole piece 72. Lower ring member 71 contains O-ring sealing groove 74 to facilitate demountable and vacuum-tight installation of the sputter source of FIG. 1 in the wall of the vacuum chamber (not shown) so that the sputter source projects from the chamber wall into the chamber. Pole piece 72 also contains O-ring sealing groove 77 to allow a vacuum-tight seal to be made to the upper side of cathode insulator 59. A concentric pair of cylindrical flashover insulators 78 and 79 is provided to prevent arcing to wall member 73 during sputter source operation. Removably attached (attachment means not shown) to outer pole piece 72 are nonmagnetic ground shield members 80 and 81, with water cooled nonmagnetic member 82 positioned between the two ground shields and cooled via water flowing through attached conduit 83. Ground shield 80 serves particularly to reduce undesired coating of cathode insulator 59 during sputter source operation.
The overall assembly of the sputter source of FIG. 1 is held together by means of clamping ring member 90. Bolts (not shown) draw clamping ring member 90 toward lower ring member 71 by passing through hole 91 and engaging threads in hole 92. In so doing, clamping ring member 90 forces base plate 34 upward, thereby effecting vacuum-tight seals by compressing O-rings in O-ring sealing grooves 23 and 58 on the lower and upper sides respectively of anode insulator 24, and also by compressing O-rings in O-ring sealing grooves 55 and 77 on the lower and upper sides respectively of cathode insulator 59.
After the sputter source is installed in the vacuum chamber and the chamber is evacuated, atmospheric pressure acts to compress the just-mentioned O-rings even further, thereby contributing positively to the vacuum integrity of the O-ring seals. This additional compression of the O-rings leads to an upward movement of base plate 34 and, correspondingly, to a reduction in tension of the bolts (not shown) which draw clamping ring member 90 toward lower ring member 71. Such reduction in bolt tension may allow clamping ring member 90 to rattle around loosely, thereby motivating an operator to retighten the bolts. This, if done, could lead to overstressing of the bolts and/or clamping ring member 90 when the vacuum system is let back up to atmospheric pressure. This problem is avoided through the se of special bolts incorporating spring-loaded ball plungers (not shown) screwed into threaded hole 93 in clamping ring member 90. The spring-loaded plungers press against base plate 34, thereby maintaining tension on the bolts (not shown) engaging threaded holes 92 after base plate 34 has moved forward upon vacuum system evacuation.
As will be discussed in greater detail, the objects of the present invention are realized by employing a modified magnetic tunnel in which one side of the magnetic tunnel is formed by a magnetic mirror. Design of the magnetic circuit overall, including particularly the geometries of the center anode pole piece 15 and outer pole piece 72, has led to the pattern of magnetic field lines 95 shown in FIG. 3. It should be noted that the arching magnetic field lines above uneroded cathode sputter surface 13 do not loop through the cathode surface, as they do in many prior art sputter sources. Rather, those magnetic field lines which do pass through cathode sputter surface 13 go directly to anode 10 rather than passing a second time through cathode sputter surface 13. It will be established subsequently that electron reflection from anode 10 back into the glow discharge occurs due to magnetic mirroring with this particular magnetic field configuration.
In typical operation, the chamber in which the sputter source is mounted is evacuated to a pressure on the order of 10 -6 Torr. The chamber is then back-filled with a sputter gas, which is typically argon, to a pressure in the range 0.1 to 100 mTorr. Ground shields 80 and 81 and anode 10 are normally held at ground potential (although anode 10 may be biased slightly above ground potential in some applications), and a potential in the range -350 volts to -1,000 volts with respect to ground is applied to cathode 12, depending on such details as anode and cathode geometry, magnetic field intensities, cathode material, sputter gas species, sputter gas pressure, and desired discharge current. By way of example, electrical connection to cathode 12 may be made by a connection to cooling conduit 50, and electrical connection to anode 10 may be made by a connection to cooling conduit 27.
It may be noted that inner magnetic pole 15 is part of anode 10, which is operated at or near ground potential. Outer magnetic pole piece 72 is electrically isolated from cathode 12, and is held at or near ground potential also. Because cathode 12 is operated at a potential of several hundred volts negative with respect to ground, ion bombardment of the pole pieces with attendant sputtering cannot occur. Thus the possibility of contamination of sputter-deposited coatings due to pole piece sputtering is avoided.
Shown in FIG. 2 is a prior art sputter source of cylindrically symmetric geometry manufactured and sold by Varian Associates, Inc. under the trademark "S-Gun". The S-gun sputter source is described in above-referenced Chapter II-3, especially FIG. 1, page 116 and FIG. 3, page 117. Descriptions in greater detail are provided by aforementioned U.S. Pat. No. 4,100,055 to Rainey, and also by U.S. Pat. No. 4,060,470 to Peter J. Clarke.
In FIG. 2, a central anode 110 is made of nonmagnetic material, such as copper, and is surrounded by an annular cathode 112. Anode 110 is mounted on anode post 115, which is nonmagnetic and is preferably made of copper. Anode post 115 has internal cooling cavity 120 through which water circulates via conduits 121. Anode post 115 is mounted, either conductively or insulatively, on nonmagnetic base plate 129 by means of flange 123.
Cathode 112 has a sputter surface 113 of generally inverted conical configuration. Cathode 112 is mounted on lower magnetic pole piece 142, and is surrounded by nonmagnetic water jacket 144. Clamping ring 165 is optionally provided to secure cathode 112 to pole piece 142. Cathode 112 and water jacket 144 are so dimensioned that room temperature clearance between them is sufficient to allow easy installation and removal of the cathode, yet small enough to provide adequate thermal contact for cathode cooling when the cathode expands upon being heated during normal operation. Water jacket 144 has internal water channel 145 through which coolant, preferably water, is circulated via conduits 150. Conduits 150 are secured to base plate 129 by means of flanges 155. Electrical isolation between base plate 129 and conduits 150 is achieved by making conduits 150 of electrically nonconducting materials. Additional support means (not shown) are employed to ensure that the desired spacing between lower pole piece 142 and base plate 129 is maintained.
The main magnetic field for this prior art magnetically enhanced sputter source is provided by a first plurality of bar magnets 128 (made, for example, of a vacuum-compatible permanent magnet material such as Alnico 8) arrayed annularly between lower magnetic pole piece 142 and an upper magnetic pole piece 172. A second plurality of bar magnets 128' is arrayed annularly above upper pole piece 172 and in magnetic opposition (or in bucking magnetic field arrangement) to the main magnetic field. The principal purpose of the bucking magnetic field arrangement is to suppress stray glow discharges in the region above the upper pole piece 172. A nonmagnetic cylinder 130 defines the outer limits for accurately locating the magnets 128 and 128' with respect to pole pieces 142 and 172, and nonmagnetic ring 176 serves to further suppress stray glow discharges above pole piece 172. The resulting magnetic field lines 195 are shown best in FIG. 4. Of particular interest are those magnetic field lines which arch above and through the sputter surface 113 of cathode 112 to form a magnetic tunnel for confining the glow discharge.
Further, surrounding cathode 112, but electrically isolated therefrom, is a generally cylindrical and nonmagnetic outer housing 170 comprising outer ground shield member 173 conductively attached to base plate 129, and separable inner ground shield member 180.
In general terms, operation of this prior art sputter source of FIG. 2 is similar to that described above for the sputter source of FIG. 1. The significant differences between the prior art sputter source of FIG. 2 and the sputter source of FIG. 1, which is the preferred embodiment of the present invention, will be elucidated below.
From the descriptions thus far, the preferred embodiment of FIG. 1 and the prior art sputter source of FIG. 2 are superficially very similar. One incidental difference is physical size, with, for example, the outer diameter of cathode 12 being approximately 7.00 inches whereas the outer diameter of cathode 112 is approximately 5.15 inches. The significant differences, however, lie in the magnetic field configurations and the magnetic circuits employed to achieve them. The magnetic field configurations in the vicinity of the cathodes are shown in detail in the fragmentary cross sectional views of FIG. 3 for the preferred embodiment and FIG. 4 for the prior art. In these figures, the new or uneroded cathode sputter surfaces are indicated by 13 and 113 respectively, while the end-of-useful-life cathode sputter surface profiles are indicated by 13' and 113'. These profiles were obtained with aluminum cathodes after operation for 400 kilowatt-hours and 148 kilowatt-hours, respectively. Measured magnetic field data are also displayed in FIGS. 3 and 4. In encircled data points 96 in FIG. 3 and 196 in FIG. 4, for example, the local direction of the magnetic field is indicated by the short, heavy line segment, and the magnitude of the magnetic field in gauss at the midpoint of the line segment is indicated by the adjacent number (180 gauss in the instance of encircled data point 96, and 103 gauss in the case of encircled data point 196). Selected magnetic field lines 95 and 195 have been constructed in general conformance with the measured magnetic field data points.
In the case of the prior art sputter source of FIG. 4, magnetic field lines 195 which arch through uneroded cathode sputter surface 113 (that is, magnetic field lines which extend from a first region of the cathode sputter surface and return to a second region thereof) form arched field lines along which electrons tend to travel. As the electrons approach the cathode surface they are mirrored or reflected back and are thus retained in a so-called tunnel formed by magnetic field lines which at each end intersect a surface at cathode potential. Such a tunnel can be aptly named a magnetic-electrostatic tunnel. Since the cathode and pole pieces are angular, the magnetic-electrostatic tunnel is a closed loop tunnel and thus retains the electrons which tend to precess in a direction into the paper and would escape from an open ended tunnel. Provided the magnetic field intensities are great enough, such magnetic-electrostatic tunnels serve to confine and magnetically enhance glow discharges.
In the case of the preferred embodiment of FIG. 3, however, the magnetic field lines which arch above the cathode and which pass through uneroded cathode sputter surface 13 do so only once, rather than twice as in the prior art case of FIG. 4. One class of magnetic field lines emanates from outer pole piece 72 and exits cathode sputter surface 13 near the outer diameter of cathode 12; these magnetic field lines do not reenter cathode 12, but rather form an arch from cathode sputter surface 13 to anode. In normal circumstances, magnetic field lines passing through an electrode held at a positive potential with respect to the cathode provide a ready conduit by which electrons can escape from the discharge. Such magnetic field lines would therefore not be expected to be effective in confining and magnetically enhancing glow discharges. In this particular case, however, care has been taken to ensure that the magnetic field intensity increases sufficiently that an adequate fraction of the electrons is reflected by magnetic mirroring, as will be discussed later. A modified electron capture tunnel is thus realized which is effective in confining and magnetically enhancing glow discharges.
Under conditions of normal operation, the glow discharge is confined by the modified electron capture tunnel above the sputter surface of the cathode. The negative glow region of the discharge, which is where most of the ions are produced by electron-gas atom or electron-gas molecule collisions, is separated from the sputter surface of the cathode by the cathode dark space. The thickness of the cathode dark space is dependent on several parameters, including anode and cathode geometries, magnetic field intensities, cathode material, sputter gas species and pressure, and discharge current. In representative cases, however, the cathode dark space thickness is approximately one millimeter, and the negative glow region of the discharge extends to several millimeters above the sputter surface of the cathode. Beyond these rather general statements, it is not a simple matter to provide a more complete description of the glow discharge on theoretical grounds.
We can, however, make use of cathode erosion patterns to draw certain inferences about the glow discharges. This is so because localized cathode erosion rates correspond generally with the immediately adjacent intensity of the discharge. On this basis it would appear that the situation with prior art sputter sources of FIG. 4 goes about as follows. When cathode 112 is new and the sputter surface is defined by 113, the glow discharge is confined by a relatively wide magnetic tunnel, whereby the discharge extends over most of the cathode sputter surface 113. Even so, discharge intensity will be greater near the center of the magnetic tunnel than near the sides, leading to correspondingly more rapid cathode erosion near the magnetic tunnel center. As cathode erosion proceeds, the discharge is confined by magnetic tunnels of progressively smaller width and larger magnetic field intensities. In addition, the centers of the magnetic tunnels move outward in radial position. By the time end-of-useful-life cathode profile 113' is reached, most of the discharge is concentrated in a relatively narrow ring near the outer edge of cathode 112, and the magnetic field intensity averaged over the discharge may have increased by, perhaps, 100%, or even more.
In the case of the preferred embodiment of FIG. 3, the magnetic tunnels which confine the flow discharge are generally much flatter, that is, much less sharply arching, than the magnetic tunnels of FIG. 4. As cathode erosion proceeds, the center of the magnetic tunnel of FIG. 3 moves radially outward, but less rapidly than the center of the magnetic tunnel of FIG. 4. In addition, the magnetic field intensity averaged over the discharge changes much less rapidly with cathode sputter surface erosion in the case of FIG. 3 than in the case of FIG. 4, the increase by end-of-useful-life being, perhaps, in the 30% to 40% range.
Several consequences result from the significant differences in magnetic field configurations of FIGS. 3 and 4. One of the more important consequences is that the electrical impedance of the glow discharge is higher and changes much less over cathode life in the case of FIG. 3. This in turn means that the operating voltage is higher, and that the voltage and current change correspondingly less at a given discharge power level. At this higher operating voltage, sputter yield increases nearly linearly with voltage. This means that the sputter deposition rate can be held essentially constant throughout cathode life by holding the input power constant when the relatively small changes in discharge impedance do occur. Experimental support for the above statement is provided in FIGS. 5a and 5b in which normalized deposition rates are plotted against cathode life in kilowatt-hours. As shown in FIG. 5a for the preferred embodiment of the present invention, the variation in the normalized deposition rate is less than the ±4% measurement uncertainty over cathode life extending out to 375 kilowatt-hours. By way of comparison, the case for the prior art sputter source of FIGS. 2 and 4 is shown in FIG. 5b, in which the normalized deposition rate has fallen by more than 40% after 140 kilowatt-hours of cathode life. The main reason for this decline in normalized deposition rate is that the discharge impedance has fallen, leading to lower voltage of operation, and, correspondingly, to even lower sputter yield. A second reason is that geometrical shielding by the sputter surface of the cathode istelf reduces the deposition rate as the end-of-useful-life cathode sputter surface profile 113' is approached.
In some applications the variation of normalized deposition rate with cathode life leads to serious problems in deposition rate control. One effort to control deposition rate in the face of the variation as shown in FIG. 5b is disclosed in earlier-referenced U.S. Pat. No. 4,166,738 to Turner and entitled "Deposition Rate Regulation by Computer Control of Sputtering Systems". With the substantially constant normalized deposition rate shown in FIG. 5a, a much simpler control system can be used to obtain the desired deposition rate.
Another consequence of the declining normalized deposition rate of FIG. 5b is that input power to the sputter source must be increased if a constant deposition rate is to be maintained. If, for example, the normalized deposition rate has fallen by 40%, it is necessary to increase input power by 67% to obtain the beginning-of-life deposition rate. Thus, more power is consumed; correspondingly, sputter source cooling problems are aggravated; and the power supply must be larger, more flexible, and more expensive than would otherwise be the case. All of these problems are eased substantially with the preferred embodiment of the present invention because of the essentially constant normalized deposition rate shown in FIG. 5a.
Another important consequence of the novel magnetic field configuration of FIG. 3 is that a significantly larger fraction of the cathode material can be utilized than with the prior art sputter source having the magnetic field configuration of FIG. 4. In the case of cathode 12 made of aluminum, the weight of cathode 12 when new, that is, with uneroded cathode sputter surface 13, is 900 grams. After 400 kilowatt-hours of typical operation, end-of-useful-life cathode sputter surface profile 13' has been reached, with a weight loss of 560 grams. Thus, by-end-of-useful-life 62% of the cathode material has been utilized. By contrast, the new weight of prior art cathode 112 is 285 grams, and the end-of-useful-life weight loss is 151 grams after 148 kilowatt-hours, which corresponds to 53% material utilization. Thus the preferred embodiment of the present invention has 17% greater material utilization than the prior art sputter source of FIGS. 2 and 4.
Yet another important consequence of the novel magnetic field configuration of FIG. 3 is that the voltage across the glow discharge is significantly higher than with the prior art sputter source having the conventional magnetic-electrostatic field configuration of FIG. 4. This point is illustrated in FIGS. 6a and 6b by the voltage-current curves taken at various argon pressures. FIG. 6a applies to the preferred embodiment of the present invention as disclosed in FIGS. 1 and 3, while FIG. 6b applies to the prior art sputter source described in FIGS. 2 and 4. For example, with argon as the sputter gas at a pressure of 10 mTorr and at an operating power level of 4.0 kilowatts, the magnitudes of voltage and current from FIG. 5a are about 605 volts and 6.6 amperes, while the voltage and current from FIG. 6b are about 410 volts and 9.8 amperes. The new sputter source thus operates at more than 47% higher voltage than the prior art sputter source in the example given. As the cathodes erode, this difference will become even greater, with the operating voltage of the new sputter source changing by a relatively small amount while the operating voltage of the prior art sputter source is declining to a significantly greater extent (see the earlier discussion relative to FIGS. 5a and 5b). The higher operating voltage of the new sputter source means that it operates at a higher sputter yield, thereby reducing the power required to achieve the desired deposition rate, thus contributing to reductions in costs for power itself, for cooling, and for power supplies.
Further evidence for higher sputtering efficiency with the new sputter source is provided by the earlier paragraph dealing with utilization of cathode material. It was reported there that the cathode weight loss was 560 grams after 400 kilowatt-hours for the new sputter source; this corresponds to an average material removal rate of 1.40 grams per kilowatt-hour. For the prior art sputter source, however, the cathode weight loss was 151 grams after 148 kilowatt-hours, which leads to an average material removal rate of 1.02 grams per kilowatt-hour. The sputtering efficiency for the new sputter source is thus 37% greater than that of the prior art sputter source.
An additional favorable feature of the new sputter source may be noted from FIGS. 6a and 6b. During sputter source operation, it is frequently desirable to maintain constant power in the face of small changes which may occur in sputter gas pressure. For example, with argon as the sputter gas and with an operating power level of 4.0 kilowatts, a change in argon pressure from 4 mTorr to 10 mTorr requires in the case of the new sputter source (FIG. 6a) that the magnitude of the applied voltage change from 740 volts to 610 volts; the voltage change of 130 volts divided by the average voltage of 675 volts is 0.193. With the same power level and argon pressure for the prior art sputter source (FIG. 6b), the required voltage changes from 525 volts to 410 volts; the voltage change of 115 volts divided by the average voltage of 462 volts is 0.249. Thus in this example the fractional voltage change required to maintain constant power is about 22% less for the new sputter source than for the prior art sputter source. This means that the problem of maintaining constant power in the face of sputter gas pressure changes is correspondingly easier with the new sputter source.
It has been stated previously that the objects of the present invention are realized in the preferred embodiment by employing a modified magnetic tunnel in which one side of the magnetic tunnel is formed by a magnetic mirror. In prior art magnetic tunnels, the energetic electrons which sustain the glow discharge are confined by magnetic field lines which arch or loop through the cathode sputter surface. Electrons tend to follow magnetic field lines as they move toward and away from the cathode. Those electrons which have been captured into the discharge are energetically incapable of reaching the cathode. Thus, even though these electrons may follow magnetic field lines toward the cathode sputter surface, they will be electrostatically reflected from the cathode sputter surface back into the discharge. (The incidental presence of magnetic mirroring in prior art magnetic tunnels was discussed briefly in the "Background of the Invention" section of the present application.)
In the preferred embodiment of the present invention, as shown in FIG. 3, the side of the magnetic tunnel near the outer edge of cathode 12 is formed by magnetic field lines which, when the cathode is new, pass through uneroded cathode sputter surface 13. These magnetic field lines do not reenter cathode 12, but instead form an arch from uneroded cathode sputter surface 13 to anode 10. Along the outer side of the magnetic tunnel, electrons are reflected electrostatically from cathode sputter surface 13 back into the glow discharge, just as in the case for both sides of prior art magnetic tunnels. On the inner side of the magnetic tunnel, however, electrostatic forces attract the electrons toward, rather than repelling them from, anode 10. Reflection of an adequate fraction of the electrons is achieved by employing a magnetic field configuration in which the magnetic field intensity increases sufficiently as the electrons approach anode 10. Such a magnetic field configuration is referred to as a magnetic mirror. Thus, a modified magnetic tunnel is formed in which the magnetic field lines (1) cause electrons to be reflected electrostatically, in the usual prior art fashion, near the outer edge of cathode 12, and (2) cause electrons to be reflected by magnetic mirroring near the inner edge of cathode 12.
To better understand how magnetic mirrors function, reference may be made to FIGS. 7a and 7b. FIG. 7a displays schematically a magnetic mirror in which magnetic field lines converge from left to right. FIG. 7b displays, also schematically and on the same scale, the relative magnitude of magnetic field intensity B(z) along some representative magnetic field line. Two representative electron trajectories are shown in FIG. 7a. ν∥(Z) and ν⊥(Z) are, respectively, the parallel and perpendicular components of electron velocity. In the first electron trajectory, at z=0, ν∥(0) is small in comparison with ν⊥(0), and electron reflection occurs at z=z 1 , while in the second electron trajectory, ν∥(0) is appreciable with respect to ν⊥(0), and electron reflection takes place at z=z 2 . As will be established shortly, z 2 is greater than z 1 . As an electron moves from left to right in a region of increasing magnetic field intensity, ν⊥(Z) increases at the expense of ν∥ (Z). Electron reflection occurs where ν∥(Z) goes to zero; this is the magnetic mirror point. In the absence of an electric field acting on the electrons, conservation of energy of the electrons requires that ##EQU1## where z r is the value of z at which electron reflection occurs.
Also in the absence of an electric field, gyrating electrons tend to conserve their magnetic moment, that is, ##EQU2## This relationship combined with the conservation of energy relationship leads to the condition for magnetic mirroring, which may be written as ##EQU3## or, alternatively, as ##EQU4## (The following references may be useful in respect to the derivation of th condition for magnetic mirroring: John David Jackson, "Classical Electrodynamics", John Wiley and Sons, Inc., New York, 1962, pp 419-424. Nicholas A. Krall and Alvin W. Trivelpiece, "Principles of Plasma Physics", McGraw Hill Book Company, New York, 1973, pp 622-623. Francis F. Chen, "Introduction to Plasma Physics", Plenum Press, New York, 1974, pp 23-31.)
Examination of the magnetic mirror equations reveals that reflection by a magnetic mirror, unlike electrostatic reflection, is not absolute. Suppose, for example, B(z) approaches a maximum value of 2B(0). All electrons for which ν∥(0) is less than ν⊥(0) will be reflected from right to left, while all of those electrons for which ν∥(0) is greater than ν⊥(0) will escape to the right. Thus, those electrons in a glow discharge having ν∥(0) greater than ∥⊥(0) will be lost from the discharge. It may be useful at this point to define the "strength" of a magnetic mirror as the ratio of the maximum value of B(Z) to B(0). In the example just considered, the strength of the magnetic mirror would be 2.
A second feature of magnetic mirrors revealed by examination of the magnetic mirror equations is that the mirror is "soft" in the sense that the region of electron reflection is not a well-defined physical surface, but depends on the ratio of parallel to perpendicular electron velocities at the interior plane defined by Z=0. For example, if ν∥(0)=0.1ν⊥(0), the mirror point will occur at the value of z at which B(Z r )=1.01B(0). Similarly, if ν∥(0)=0.5ν⊥(0) electron reflection will occur when B(Z r )=1.25B(0).
In the above treatment of magnetic mirrors it was assumed that no electric fields are acting on the electrons. To the extent that electric fields are present, electron trajectories and points of reflecton will be modified.
When voltage is applied to uneroded cathode 12 of FIGS. 1 and 3 without sputter gas being present, a glow discharge will not normally be established, and the electric field distribution in the space above uneroded cathode sputter surface 13 can be estimated or measured by straightforward methods. Upon establishing a glow discharge by introducing a sputter gas, a very different electric field distribution will come into existence. Most of the applied voltage will appear across the cathode dark space adjacent uneroded cathode sputter surface 13. Electric field intensities in the cathode dark space region will be much greater than in the absence of the glow discharge. The electric field lines will, of course, be normal to uneroded cathode sputter surface 13, and hence will be generally transverse to magnetic field lines 95.
Energetic electrons are essential to sustaining the discharge by giving up their energy through a series of ionizing collisions with sputter gas atoms or molecules. Most of the energetic electrons which are captured into the discharge originate as a result of secondary electron emission from the cathode sputter surface due to positive ion bombardment. These electrons are immediately acted upon by the strong electric field in the cathode dark space, and are accelerated into the negative glow region above the cathode dark space. This leads to electron paths which are generally cycloidal in nature, with the electrons drifting circumferentially above cathode 12 and around central anode 10. The generally transverse nature of the electric and magnetic fields to each other above uneroded cathode sputter surface 13 means that most of the energetic electrons which are captured into the discharge will have velocities which are predominantly perpendicular to rather than parallel with the magnetic field lines, that is, ν∥ will generally be significantly less than ν⊥. Thus these electrons can be confined by a magnetic mirror of modest strength, which is fortunate in view of the crucial role played by these electrons in sustaining the discharge. The main need for a strong magnetic mirror arises from discharge initiation consideration.
The magnetic field data shown in FIG. 3, exemplified encircled data points 96, reveal that the magnetic field intensity along a representative magnetic field line 95 varies slowly from the point where it exits uneroded cathode sputter surface 13 to the general center of the corresponding modified magnetic tunnel. Near the inner edge of cathode 12, the magnetic field intensity along this magnetic field line has approximately doubled. Thus the magnetic mirror used in the modified magnetic tunnel of the preferred embodiment of the present invention, as shown in FIGS. 1 and 3, has a strength, as defined earlier, of about 2, which is sufficient to reflect back into the glow discharge most electrons for which ν∥ is less than ν⊥. The experimental findings, as described earlier, are that the new sputter source exhibits superior performance in most, if, indeed, not all, significant respects over the prior art sputter source of FIGS. 2 and 4. These results confirm the utility in magnetically enhanced sputter sources of magnetic mirrors in which the mirror strength is on the order of 2.
The demonstrated utility of magnetic mirrors in sputter source provides a new dimension of design freedom. As shown in FIGS. 1 and 3, the magnetic circuit has been configured to produce magnetic field lines which are substantially parallel to uneroded cathode sputter surface 13 over most of its extent. This is in sharp contrast to the prior art sputter sources in which the magnetic field lines exit and reenter the cathode sputter surface, forming relatively narrow arches over the cathode, as shown, for example, in FIGS. 2 and 4. Because the magnetic field lines in FIG. 3 are substantially parallel to uneroded cathode sputter surface 13, the glow discharge is more spread out and more uniform in intensity than in prior art sputter sourcs employing conventional magnetic tunnels. Moreover, the intrinsic softness of the magnetic mirror allows the glow discharge to extend radially inward farther than would be the case for the electrostatic reflection which dominates in conventional magnetic tunnels. Finally, the use of a magnetic mirror has made it feasible to reduce the change in magnetic field intensity averaged over the glow discharge as the cathode is eroded away by sputtering. These just-mentioned factors are in large measure responsible for the superior sputter source performance described earlier.
Realization of a magnetic mirror is accomplished by so configuring the magnetic circuit that the magnetic field lines converge. Suppose, for example, that field lines passing through transversely oriented area A 0 in the central region of the glow discharge, and that these same magnetic field lines pass through transversely oriented area A a adjacent the anode. If B o is the average intensity of the magnetic field lines passing through A o , then the average magnetic field intensity adjacent the anode, B a , is ##EQU5## and the strength of the magnetic mirror, as defined previously, is just ##EQU6## In the preferred embodiment of the present invention as shown in FIGS. 1 and 3, the magnetic field lines appear to converge by a factor of approximately 1.6 in the transverse plane of FIG. 3 in going from the central region of the glow discharge to the inner edge of cathode 12. In addition, these magnetic field lines converge further by the radial convergence factor, which is the effective radial distance to the central region of the glow discharge divided by the inner radius of cathode 12. This radial convergence factor may be taken to be about 1.4, leading to a magnetic mirror strength of approximately 1.6×1.4=2.2.
Much of the discussion concerning the modified magnetic tunnels of the present invention has been restricted to the situation in which cathode 12 is new, and hence uneroded. In this configuration, the side of the magnetic tunnel near the outer edge of cathode 12 is formed by magnetic field lines which pass through uneroded cathode sputter surface 13. These magnetic field lines do not reenter the cathode 12, but instead form an arch to anode 10. Along the outer side of the magnetic tunnel, electrons are reflected electrostatically from cathode sputter surface 13 back into the glow discharge. On the inner side of the magnetic tunnel, electrons are reflected back into the discharge by magnetic mirroring.
In normal operation the cathode is eroded away by sputtering. After about 400 kilowatt-hours of normal operation with an aluminum cathode, the end-of-useful-life cathode sputter surface profile 113' has been attained. With this eroded configuration, some of the magnetic field lines which exit cathode sputter surface 13' near the outer edge now reenter this surface en route to anode 10. It is likely that by end-of-useful-life the discharge is confined by a magnetic tunnel in which electrons are reflected largely electrostatically along the inner side of the tunnel, as well as along the outer side, rather than being reflected by magnetic mirroring as they were when the cathode was new. It is believed that this conversion from a soft magnetic mirror to a hard electrostatic mirror causes the glow discharge to become more concentrated in a narrower ring toward the outer edge of cathode 12, leading to comparatively rapid erosion in that region as end-of-useful-life approaches. Based on experimentally observed evolution of cathode sputter surface profiles with operation, it is believed that this change in the mode of reflection occurs near the end-of-useful-life cathode. As noted earlier, the glow discharge normally extends several millimeters above the cathode. Hence, the magnetic field which is effective in confining the glow discharge is a field averaged in some fashion over the discharge rather than being just the field averaged over the cathode sputter surface.
The fact that a transition from magnetic mirror reflection to electrostatic reflection occurs reduces erosion near the inner edge of cathode 12; it also hastens end-of-useful-life by concentrating the discharge in a narrower ring toward the outer edge of cathode 12. While it would be preferable to avoid this change in mode of reflection altogether, the fact remains that greatly improved sputter source performance is achieved with the preferred embodiment of the present invention, as shown in FIGS. 1 and 3, over prior art sputter sources such as the one shown in FIGS. 2 and 4. As discussed earlier, this is due in large measure to the new dimension of design freedom which the use of magnetic mirrors allows.
While the invention has been described with reference to specific arrangements of parts, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. | An optimized annular sputter target for use in a sputter coating source has a cross sectional shape comprising a front surface from which material is to be sputtered, an outer rim and an inner rim, a back surface generally opposite said sputter surface, said outer rim having a first portion intersecting said back surface and a second portion intersecting said front sputter surface, said second portion extends outwardly from said first portion, said outer rim is substantially longer in a direction parallel to the axis of said annular target than is said inner rim, and said inner rim slopes outwardly from its intersection with said front sputter surface. | 7 |
This application is a continuation-in-part of our application Ser. No. 764,313 filed Jan. 31, 1977, now abandoned.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to photochromic glasses, i.e. to glass compositions which darken on exposure to actinic radiation and fade back to their original, normally colourless, state when no longer exposed.
This invention relates to photochromic glasses, i.e. to glass compositions which darken on exposure to actinic radiation and fade back to their original, normally colourless, state when no longer exposed.
In our British patent specification No. 1367903, we have described and claimed a range of photochromic glasses comprising at least 17% by weight P 2 O 5 as one of the glass forming components, with silver halide crystals dispersed throughout the glass, the total silver content of the glass being at least 0.05% by weight Ag. The specific glasses disclosed in that Specification are alumino-phosphate glasses comprising not more than 40% by weight SiO 2 and between 9% and 34% by weight Al 2 O 3 as further glass forming components, and at least 10% by weight R 1 O, where R=K, Na or Li. They can also contain up to 19% by weight B 2 O 3 , though most of the glasses disclosed contain no more than 3 to 7% B 2 O 3 .
Glasses falling with the claims of British Patent 1367903 are now used in the manufacture of ophthalmic lenses for both sunglasses and prescription spectacles. These alumino-phosphate glasses, like the photochromic borosilicate glasses also available in the market, while exhibiting desirable photochromic properties, have relatively slow responses to exposure and removal of actinic radiation, i.e. slow darkening and fading rates. It is desirable, particularly for ophthalmic purposes, to have glasses with faster responses, particularly a faster fading rate. A rapid fading rate is desirable to aid in adjustment to a sudden decrease in available light, such as when a wearer of spectacles with lenses of photochromic glass enters a dimly-lit room.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a range of photochromic glasses having improved properties and in particular glasses which provide an improved combination of photochromic effect (measured as the induced optical density or change in light transmission when irradiated with actinic radiation) and speed of response to irradiation or removal of radiation.
According to the present invention, a photochromic alumino-phosphate glass having silver halide crystals dispersed throughout the glass consists essentially of, in weight percentages,: SiO 2 : 8.5 to 25%, Al 2 O 3 : 13 to 36.5%, P 2 O 5 : 7.5 to 33.5%, B 2 O 3 : 7 to 28%, R 2 O: 7 to 20.5%, R'O: 0 to 21%, TiO 2 : 0 to 6%, ZrO 2 : 0 to 10%, PbO: 0 to 8%, where R 2 O represents at least one of Na 2 O, K 2 O, and Li 2 O, the maximum content of Li 2 O being 5%; and R'O represents at least one of MgO, CaO, SrO, and BaO, within the following individual limits: MgO: 0 to 4%, CaO: 0 to 6.5%, SrO: 0 to 10%, BaO: 0 to 21%; the amount of SiO 2 is not less than 16% when the B 2 O 3 content is less than 8%; and the silver content of the glass, expressed as Ag 2 O, is not less than 0.05% by weight.
These glasses have been found to have a good combination of induced optical density on irradiation with actinic light and rapid darkening on irradiation and rapid fading when irradiation ceases. It will be understood that, as a general rule, the darkening and fading times are longer when the induced optical density is greater.
In these glasses, it is possible for Al 2 O 3 , B 2 O 3 or P 2 O 5 to be the largest constituent. The preferred range of glasses for opthalmic purposes is that in which the largest constituent is Al 2 O 3 which is present in an amount of not less than 22 weight %, while the content of P 2 O 5 does not exceed 25.5 weight % and the content of B 2 O 3 does not exceed 24.5 weight %. Glasses within this preferred range can be formulated to have a fast response to irradiation or the removal of irradiation, coupled with physical properties which make them suitable for manufacture on a commercial scale and for use as ophthalmic lenses. For example, the liquidus temperature and viscosity of the molten glass can be chosen to suit conventional forming processes, while the hardness of the glass is appropriate for conventional grinding and polishing processes. The refractive index can be adjusted to the standard value of 1.523 which is conventional for ophthalmic use, and the glass can have a good chemical resistance or durability.
In general, it is only practicable to operate with contents of both Al 2 O 3 and SiO 2 at the upper ends of the ranges set out above in cases where a high viscosity is required at the liquidus temperature, which itself is not too high, for example where the glass is to be formed into sheet glass.
Another range of glasses within the scope of the present invention is that wherein the largest constituent is B 2 O 3 which is present in an amount of not less than 25 weight %, while the content of Al 2 O 3 does not exceed 20 weight % and the content of P 2 O 5 does not exceed 20 weight %.
A further range of glasses according to the present invention is that wherein the largest constituent is P 2 O 5 which is present in an amount of not less than 21.5 weight %, while the content of Al 2 O 3 does not exceed 26 weight % and the content of B 2 O 3 does not exceed 17.5 weight %.
If the liquidus temperature is made relatively low, e.g. as a result of the use of a relatively large amount of B 2 O 3 and a relatively small amount of SiO 2 , it is important to keep a watch that the durability of the glass (e.g. as tested by absence of attack in acid and alkali solution) is still acceptable. The degree of durability which is acceptable will of course vary according to the proposed use of the glass. Thus a glass which has insufficient durability for ophthalmic use but good photochromic properties may be of value for use in instruments or other uses where it is not exposed to attack.
When the B 2 O 3 level approaches the lower limit, i.e. is less than 8%, it is necessary that the SiO 2 content is at least 16% in order to ensure both the desired fast response and adequate durability for ophthalmic purposes.
R 2 O may be constituted solely by K 2 O, or by a combination of two or more of K 2 O, Li 2 O and Na 2 O, or by Na 2 O alone. Where R 2 O is Na 2 O alone, it should preferably not exceed 14% by weight, to avoid possible problems in glass forming and durability,
In the case of glasses intended for ophthalmic use, it is advantageous for the glasses to be capable of being toughened by the conventional ion exchange process, in which larger metal ions are exchanged for smaller metal ions in a surface layer of the glass to produce a compressive stress therein. The ion exchange is effected by immersing the glass in a molten salt bath. Generally potassium ions are exchanged for sodium and/or lithium ions in a bath of molten KNO 3 , or sodium ions are exchanged for lithium ions in a molten NaNO 3 bath. Thus where the glass is to be chemically toughened in this way it is preferred that the R 2 O component should include Na 2 O and/or Li 2 O. We prefer to use a mixture of alkali metal oxides, with K 2 O always present, and to keep each of Na 2 O and Li 2 O below 5%. The depth of penetration of the exchanged ions, and the compressive stress produced, can be varied by varying the temperature of the molten salt bath. In general, the greater the penetration, the lower the compressive stress and vice versa, so an advantageous compromise must be found by experiment.
As indicated above, the silver content of the glass, expressed as Ag 2 O, is not less than 0.05% by weight, because with lower amounts of Ag 2 O it can be difficult to achieve adequate darkening. Preferably the Ag 2 O is not less than 0.06%.
The glass may comprise from 1 to 21% by weight R'O, where R'O represents at least one of MgO, BaO, SrO and CaO, within the following individual limits:
MgO: 0 to 4% CaO: 0 to 6.5% SrO: 0 to 10%
BaO: 0 to 21%
For ophthalmic use, it is convenient for the glass to have a refractive index (n D ), measured for light of the wavelength of the sodium D line, which is as close as possible to the standard figure of 1.523. To adjust the refractive index to this figure, additions of proportions of TiO 2 , ZrO 2 and/or PbO can be of value, though care is needed to avoid problems arising from too large a quantity of one or more of these components. The amount of TiO 2 used should not exceed 6% by weight, in order to avoid dangers of crystallisation and unwanted colouration of the glass, the normal preferred limit being 3% by weight. ZrO 2 should not exceed 10 weight % in order to avoid unacceptable increases in liquidus temperature, the normal preferred limit being 7 weight %. PbO can be incorporated in quantities up to 8% by weight. Small quantities of other additives, such as HfO 2 (up to 3%) and ZnO (up to 6%) may be incorporated for the same purpose. Tinting agents may also be added in known manner, to provide a fixed tint in addition to the variable photochromic colouring.
As is known, the photochromic effect is produced by the silver halide crystals referred to above. Minor amounts of copper oxides assist the development of the photochromic effect, and larger amounts may be used to provide a fixed tinting effect in addition. The preferred amounts of the photochromic components, namely the silver (expressed as Ag 2 O), the copper oxide and the halides (Cl and Br), which are expressed in accordance with the normal convention as quantities over and above the 100% total of all other components of the glass, are as follows:
Ag 2 O: 0.06 to 0.60% CuO: 0.005 to 1.0%
Cl+Br: 0.20 to 2.0%
Cl: 0 to 1.0%
Br: 0.08 to 1.0%
In most cases, the photochromic effect can be enhanced by heat treatment of the glass, the appropriate heat treatment schedule being primarily determined by the viscosity-temperature relationship of the particular glass. In general, the heat treatment temperature lies between the strain point and the softening point of the glass, the heat treatment time required being several hours at the lower temperature but only a few minutes at the higher temperature. At the higher temperature, however, deformation an clouding of the glass may occur, so it is preferred for convenience to use a temperature 20° to 100° C above the annealing point and a heat treatment time of 10 to 60 minutes.
The schedule may be imposed on the glass directly after forming or the glass may be annealed and cooled to room temperature before heat treatment. The cooling rate to which the glass is subjected after heat treatment is sometimes found to have an effect on the photochromic properties of the final product. This cannot be stated as a general rule, however, and must be determined by experimentation on individual glasses.
The temperature/time schedule imposed on a glass is also determined by the concentrations of photochromic agents in the glass and the photochromic property requirements of the final product. In general, the higher the levels of the components contributing to the photochromism the shorter will be the heat treatment schedule, and in some cases, the photochromism may develop during cooling from the melt or annealing of the glass. Excessively long heat treatments are generally to be avoided because they may lead to some clouding of the glass.
DETAILED DESCRIPTION OF THE INVENTION
Specific embodiments of the invention will now be described in more detail by way of example, and with reference to the following Table I, which sets out examples of glass compositions in accordance with the invention, showing their compositions on the oxide basis and the photochromic effect achieved in terms of the induced optical density (ODd) and the time in seconds taken to fade to a condition of half the total induced optical density (1/2 OD FT), measured with standard samples of glass 2 mm thick, in standard simulated solar conditions at air mass 2 (see Parry Moon, J. Franklin Inst., 230 (1940), pages 583-617). The induced optical density is the difference between the optical density of the glass in the fully darkened state and the optical density in the fully faded state, the optical density being defined in the conventional manner as log 10 Ii/I t , where Ii is the intensity of the incident light and I t is the intensity of the transmitted light. The induced optical density is thus a real measure of the photochromic effect and is in fact directly proportional to the number of photochromically activated silver atoms in a given volume of the glass. The time required to fade from the fully darkened condition to a condition of half the induced optical density (1/2 OD FT) is thus an effective measure for comparing fading times of glasses having different values of light transmission in the bleached or faded state and is comparable with the half-fading times referred to in our earlier Specification No. 1367903.
Table I also lists the temperature (HT° C) at which each of the glasses was heat treated. A standard heat treatment time of 20 minutes was used in each case, for comparative purposes only.
Finally Table I lists the refractive index n D of most of the glasses.
TABLE I__________________________________________________________________________Glass No.Wt% 1 2 3 4 5 6 7 8 9 10 11 12 13 14__________________________________________________________________________SiO.sub.223.1 23.1 21.7 20.4 21.2 17.9 17.0 17.0 17.0 22.2 22.5 21.5 21.2 20.4Al.sub.2 O.sub.319.8 13.9 19.0 23.5 25.6 15.6 19.6 19.6 19.6 27.4 30.7 29.5 25.6 23.5P.sub.2 O.sub.512.8 19.4 26.5 32.8 25.9 21.8 27.3 27.3 27.3 17.8 22.3 21.3 25.9 32.7B.sub.2 O.sub.327.5 26.8 17.1 8.4 11.9 14.1 7.0 7.0 7.0 16.6 12.6 12.0 11.9 8.4Li.sub.2 ONa.sub.2 O.1 8.2 13.6K.sub.2 O15.4 15.2 14.3 13.5 14.0 9.8 9.3 9.3 9.3 14.6 2.3 14.2 14.0MgO 1.3 1.5 1.4 1.3 1.4 1.4 1.5 1.4 1.4 1.3CaOSrOBaO 20.8 19.8 19.8 19.8PbOTiO.sub.2ZrO.sub.2HfO.sub.2ZnOAg.sub.2 O.27 .17 .08 .09 .12 .12 .12 .12 .11 .10 .12 .18 .16 .08CuO .013 .029 .031 .035 .035 .036 .033 .045 .040 .029 .038 .030 .035 .045Cl .13 .37 .22 .17 .13 .35 .40 .49 .48 .18 .17 .27 .29 .34Br .39 .40 .28 .22 .17 .44 .41 .49 .40 .22 .27 .26 .24 .45ODd .307 .334 .283 .202 .261 .184 .223 .226 .33 .071 .066 .094 .308 .1001/2 OD FT3 20 20 20 10 7 8.5 12 20 2 2 1 12 24HT° C625 520 620 550 660 635 640 630 630 705 705 750 640 610n.sub.D1.480 1.478 1.482 1.484 1.483 1.519 1.519 1.519 1.519 1.482 1.487 1.482 1.483Wt% 15 16 17 18 19 20 21 22 23 24 25 26 27 28__________________________________________________________________________SiO.sub.219.9 20.0 20.0 20.0 19.6 19.4 18.8 18.8 18.0 20.0 20.8 20.4 20.1 19.7Al.sub.2 O.sub.322.9 23.0 23.0 23.0 22.6 22.3 21.6 21.6 20.7 23.0 23.9 23.5 23.1 22.7P.sub.2 O.sub.531.9 32.0 32.0 32.0 31.4 31.1 30.1 30.1 28.8 32.0 33.3 32.7 32.1 31.6B.sub.2 O.sub.38.2 8.2 8.2 8.2 8.1 8.0 7.7 7.7 7.4 8.2 8.5 8.4 8.3 8.1Li.sub.2 ONa.sub.2 O 4.8 5.4K.sub.2 O13.1 13.2 13.2 13.2 12.9 12.8 12.4 12.4 11.8 13.2 7.4 8.3 9.1 10.0MgO 3.9 1.3 1.3 1.3 1.3CaO 3.6 3.6 3.6 5.3 3.6SrO 6.5 9.4 3.6BaOPbOTiO.sub.2 9.3 13.3ZrO.sub.2HfO.sub.2ZnOAg.sub.2 O.07 .08 .08 .07 .07 .07 .07 .08 .07 .09 .15 .09 .07 .09CuO .043 .043 .045 .036 .045 .041 .040 .043 .043 .047 .036 .041 .038 .039Cl .17 .24 .41 .40 .34 .27 .25 .30 .31 .28 .30 .25 .30 .29Br .21 .27 .46 .28 .33 .34 .35 .32 .34 .34 .35 .35 .35 .38ODd .281 .217 .283 .243 .200 .187 .190 .146 .181 .294 .203 .231 .238 .2141/2 OD FT30 13.5 15 10 16 10 18 12 33 15 18 18 33 24HT° C665 645 645 645 630 610 615 610 680 670 550 610 610 610n.sub.D1.478 1.491 1.491 1.491 1.491 1.499 1.494 1.498 1.507 1.491 1.485 1.485 1.486 1.486Wt% 29 30 31 32 33 34 35 36 37 38 39 40 41 42__________________________________________________________________________SiO.sub.220.3 20.6 20.7 19.9 20.2 20.6 23.4 23.1 23.2 22.9 23.1 23.0 23.5 17.0Al.sub.2 O.sub.323.3 23.7 23.8 22.9 23.3 23.7 19.2 19.0 19.1 18.8 19.0 18.9 19.3 19.6P.sub.2 O.sub.532.5 32.9 33.2 31.9 32.4 33.0 12.5 12.3 12.4 12.2 12.3 12.3 12.5 27.3B.sub.2 O.sub.38.3 8.5 8.5 8.2 8.3 8.5 27.0 26.8 26.9 26.5 26.8 26.6 27.2 7.0Li.sub.2 O 0.6 0.38Na.sub.2 O4.0 6.9 8.4 4.6 7.5 4.9K.sub.2 O10.3 6.2 4.1 11.2 7.1 7.4 15.4 15.2 15.3 15.1 15.2 15.1 15.5 9.3MgO 1.3 1.3 1.3 1.3 1.3 1.4 1.5 1.5 1.5 1.5 1.5 1.5 1.5CaOSrOBaO 19.8PbOTiO.sub.2 1.0 2.0ZrO.sub.2 1.54 3.0HfO.sub.2 2.6ZnO 2.0Ag.sub.2 O.06 .08 .08 .07 .06 .08 .15 .15 .12 .10 .13 .12 .15 .076CuO .044 .044 .042 .039 .036 .042 .026 .026 .026 .026 .033 .031 .030 .014Cl .54 .35 .28 .24 .27 .26 .34 .31 .35 .31 .37 .30 .57 .30Br .33 .24 .40 .24 .32 .33 .33 .29 .33 .29 .29. .24 .32 .35ODd .271 .226 .170 .279 .275 .172 .127 .118 .041 .043 .142 .051 .175 .1431/2 OD FT10 12 15 15 15 8 3 3 1 1 6 1 10 18HT° C610 555 555 600 510 600 560 560 630 630 630 630 520 630n.sub.D1.485 1.487 1.486 1.486 1.487 1.489 1.4865 1.4915 1.4860 1.4905 1.4855 1.4850 1.5005 1.519Wt% 43 44 45 46 47 48 49 50 51 52 53__________________________________________________________________________SiO.sub.217.0 17.0 17.0 17.0 17.0 17.0 17.0 21.5 21.5 21.5 21.5Al.sub.2 O.sub.319.6 19.6 19.6 19.6 19.6 19.6 19.6 29.5 29.5 29.5 29.5P.sub. 2 O.sub.527.3 27.3 27.3 27.3 27.3 27.3 27.3 21.3 21.3 21.3 21.3B.sub.2 O.sub.37.0 7.0 7.0 7.0 7.0 7.0 7.0 12.0 12.0 12.0 12.0Li.sub.2 ONa.sub.2 OK.sub.2 O9.3 9.3 9.3 9.3 9.3 9.3 9.3 14.2 14.2 14.2 14.2MgO 1.4 1.4 1.4 1.4CaOSrOBaO 19.8 19.8 19.8 19.8 19.8 19.8 19.8PbOTiO.sub.2ZrO.sub.2HfO.sub.2ZnOAg.sub.2 O.09 .24 .26 .32 .35 .16 .10 .37 .56 .31 .24CuO .040 .044 .046 .038 .041 .16 .16 .038 .036 .038 .039Cl .33 .19 .19 .48 .50 .44 .44 .26 .21 .35 .12Br .30 .41 .40 .18 .49 .10 .09 .18 .18 .09 .23ODd .130 .416 .389 .531 .215 .44 .18 .212 .308 .232 .1211/2 OD FT20 25 20 80 35 24 15 2 2 2 1HT° C630 630 630 630 630 630 630 662 685 685 705n.sub.D1.519 1.519 1.519 1.519 1.519 1.519 1.519 1.482 1.482 1.482 1.482Wt% 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68__________________________________________________________________________SiO.sub.221.5 21.5 21.4 17.0 17.0 21.4 21.4 21.4 22.9 22.3 21.8 21.4 21.2 20.5 19.9Al.sub.2 O.sub.329.5 29.4 29.3 19.6 19.6 29.3 29.3 29.3 18.9 18.4 17.9 18.8 18.6 18.0 17.4P.sub.2 O.sub.521.3 21.3 21.2 27.3 27.3 21.2 21.2 21.2 12.2 11.9 11.6 26.1 25.8 25.0 24.2B.sub.2 O.sub.312.0 12.0 12.0 7.0 7.0 12.0 12.0 12.0 26.6 25.9 25.2 16.8 16.6 6.1 15.6Li.sub.2 ONa.sub.2 OK.sub.2 O14.2 14.2 14.2 9.3 9.3 14.2 14.2 14.2 15.1 14.7 14.3 14.1 13.9 13.5 13.1MgO 1.4 1.4 1.4 1.4 1.4 1.4 1.5 1.4 1.4 2.8CaO 3.8SrO 6.85BaO 19.8 19.8 9.8PbO .25 .5 .5 .5 .5 2.8 5.4 7.8TiO.sub.2ZrO.sub.2HfO.sub.2ZnOAg.sub.2 O.29 .27 .31 .36 .35 .25 .27 .36 .13 .10 .18 .095 .099 .12 .13CuO .19 .038 .044 .16 .18 .035 .075 .038 .030 .032 .030 .038 .036 .044 .039Cl .25 .22 .19 .53 .33 .12 .28 .19 .28 .22 .21 .23 .22 .34 .38Br .16 .19 .18 .08 .09 .26 .17 .15 .22 .14 .17 .25 .26 .34 .39ODd .05 .616 .617 .636 .579 .372 .390 .861 1.17 0.90 1.09 .196 .183 .234 .261/2 OD FT1 18 14 63 24 10 8 24 400 140 840 8 8 8 15HT° C705 725 720 640 640 745 735 720 580 570 600 645 645 645 615n.sub.D1.482 1.486 1.491 1.519 1.519 1.491 1.491 1.491 1.4815 1.4915 1.497 1.483 1.488 1.496 1.499Wt% 69 70 71 72 73 74 75 76 77 78 79 80 81 82__________________________________________________________________________SiO.sub.222.0 22.5 22.2 21.6 21.2 20.8 17.5 13.7 18.0 14.4 10.9 17.7 14.0 10.5Al.sub.2 O.sub.319.3 30.7 30.3 29.5 28.9 28.4 32.9 35.5 29.3 29.2 29.0 31.6 33.2 34.7P.sub.2 O.sub.526.8 22.3 22.0 21.4 21.0 20.6 22.8 24.7 21.2 21.1 21.0 22.0 23.2 24.3B.sub.2 O.sub.317.3 12.7 12.5 12.1 11.8 11.6 11.7 11.4 16.0 19.9 23.8 13.4 14.7 15.9Li.sub.2 ONa.sub.2 O11.7 9.8 11.1 5.4 6.0 6.6K.sub.2 O 8.1 9.2 10.1 13.7 13.3 14.1 14.0 13.9 13.9 13.6 13.3MgO 2.9 1.47 1.45 1.41 1.38 1.36 1.36 1.32 1.39 1.38 1.38 1.37 1.34 1.32CaOSrOBaOPbO .5 .5 .5 .5 .5TiO.sub.2ZrO.sub.2HfO.sub.2ZnOAg.sub.2 O.13 .32 .31 .29 .27 .26 .26 .28 .24 .25 .25 .24 .29 .28CuO .048 .041 .048 .037 .037 .037 .036 .036 .036 .037 .037 .o36 .033 .036Cl .32 .21 .25 .24 .28 .32 .31 .27 .33 .30 .31 .30 .26 .28Br .34 .23 .25 .26 .23 .25 .25 .23 .22 .28 .28 .24 .27 .29ODd .10 .184 .228 .319 .336 .453 .152 .199 .115 .13 .144 .119 .135 .1221/2 OD FT6 5 4 12 12 30 2 3 2 2 2 1 2 1HT° C630 745 745 720 710 710 720 720 720 720 710 725 725 725n.sub.D1.487 1.487 1.489 1.487 1.488 1.490 1.484 1.484 1.483 1.483 1.483 1.484 1.485 1.486Wt% 83 84 85 86 87 88 89 90 91 92 93 94 95 96__________________________________________________________________________SiO.sub.211.2 10.7 10.5 10.2 9.9 10.4 10.2 9.7 9.3 9.4 9.1 9.4 9.7 10.1Al.sub.2 O.sub.329.7 28.4 27.7 27.1 26.2 27.6 26.8 25.6 24.5 24.8 24.0 25.0 25.7 26.8P.sub.2 O.sub.521.5 20.5 20.1 19.6 19.0 20.0 19.4 18.7 17.8 18.1 17.5 18.1 18.6 19.4B.sub.2 O.sub.324.3 23.3 22.7 22.2 21.5 22.6 22.0 21.0 20.1 20.3 19.7 20.5 21.0 22.0Li.sub.2 ONa.sub.2 O4.7K.sub.2 O7.1 13.6 13.3 13.1 12.6 13.6 13.5 13.5 11.8 13.1 12.6 12.0 12.3 12.9MgO 1.41CaO .94 1.53 2.09 2.89 1.56 2.17 3.08 4.43 3.87 4.61 1.63 4.23SrOBaO 2.56 4.17 5.71 7.89 4.25 5.93 8.42 12.1 10.6 12.61 15.1 11.1 4.66PbOTiO.sub.2ZrO.sub.2ZnOAg.sub.2 O.28 .26 .26 .27 .21 .23 .21 .21 .27 .22 .23 .27 .22 .23CuO .038 .038 .038 .038 .038 .038 .038 .038 .038 .038 .038 .038 .038 .038Cl .26 .40 .44 .32 .37 .38 .34 .39 .46 .60 .52 .46 .34 .36Br .32 .43 .37 .39 .32 .37 .33 .35 .33 .38 .33 .35 .37 .38ODd .10 .168 .144 .208 .311 .167 .24 .418 .383 .727 .549 .52 .382 .2801/2 OD FT2 5 3 4 7 4 4 10 11 18 17 22 12 5HT° C640 640 640 640 640 640 640 620 605 660 635 615 615 640n.sub.D 1.454 1.491 1.496 1.515 1.491 1.496 1.505 1.519 1.514 1.519 1.51 1.507 1.502Wt% 97 98 99 100 101 102 103 104 105 106 107 108 109__________________________________________________________________________SiO.sub.210.4 9.9 9.9 9.9 9.9 9.9 10.35 9.68 10.12 10.21 10.30 10.43 9.38Al.sub.2 O.sub.327.6 26.2 26.2 26.2 26.2 26.3 27.47 25.69 26.85 27.09 27.33 27.67 24.80P.sub.2 O.sub.520.0 19.0 19.0 19.0 19.0 19.0 19.89 18.60 19.44 19.61 19.79 20.03 18.09B.sub.2 O.sub.322.6 21.5 21.5 21.5 21.5 21.5 22.51 21.05 22.00 22.00 22.39 22.67 20.33Li.sub.2 ONa.sub.2 O 2.05 7.85 4.19 3.88 3.56 7.85K.sub.2 O13.3 12.6 12.6 12.6 12.6 10.04 14.43 6.37 5.89 5.40 13.01MgOCaO 6.11 2.59 2.89 2.89 2.89 2.89 3.0 2.82 2.95 2.98 3.01 3.04 2.98SrOBaO 7.89 7.89 7.89 7.89 7.89 8.2 7.72 8.07 8.14 8.22 8.32 11.41PbOTiO.sub.2ZrO.sub.2ZnOAg.sub.2 O.28 .27 .20 .17 .21 .26 .29 .22 .26 .26 .29 .26 .26CuO .038 .038 .038 .038 .038 .035 .037 .037 .037 .037 .037 .037 .037Cl .40 .38 .50 .29 .38 .60 .43 .39 .49 .49 .55 .34 .65Br .34 .31 .32 .31 .31 .37 .32 .28 .39 .39 .39 .36 .51ODd .203 .36 .396 .255 .321 .376 .547 .452 .226 .421 .556 .451 .4451/2 OD FT4 8 8 5 9 7 12 12 20 33 15 21 16HT° C640 640 640 649 640 640 680 610 660 680 680 680 625n.sub.D1.499 1.505 1.505 1.505 1.505 1.506 1.513 1.505 1.509 1.508 1.509 1.511 1.513Wt% 110 111 112 113 114 115 116 117 118 119 120 121 122 123__________________________________________________________________________SiO.sub.29.08 8.81 9.61 9.53 10.6 10.2 10.0 9.8 9.5 10.0 9.1 10.0 9.5 9.5Al.sub.2 O.sub.324.02 23.28 25.41 25.19 33.6 34.0 33.3 32.6 31.6 33.2 30.1 33.1 31.6 31.6P.sub.2 O.sub.517.52 16.98 18.54 18.38 24.9 23.8 23.2 22.7 22.0 23.2 21.0 23.1 22.0 22.0B.sub.2 O.sub.319.68 19.08 20.83 20.65 16.1 15.6 15.2 14.9 14.5 15.2 13.8 15.2 14.5 14.8Li.sub.2 ONa.sub.2 OK.sub.2 O13.01 12.21 13.33 13.22 13.5 13.1 12.8 12.5 12.1 13.0 11.5 12.7 12.1 12.1MgO 1.33CaO 2.98 2.80 3.05 3.03 0.9 1.46 2.00 2.8 1.46 5.86 2.8 2.8SrOBaO 14.21 16.83 8.35 8.28 2.45 4.00 5.48 7.58 4.0 14.5 7.58 7.58PbOTiO.sub.2 0.87 1.73ZrO.sub.2ZnOAg.sub.2 O.22 .25 .23 .23 .30 .26 .36 .26 .25 .27 .24 .24 .22 .21CuO .037 .037 .037 .037 .038 .308 .038 .038 .038 .038 .038 .038 .038 .038Cl .47 .44 .53 .43 .2 .33 .30 .31 .36 .30 .41 .36 .39 .38Br .31 .36 .38 .26 .37 .38 .34 .32 .31 .28 .31 .25 .24 .31ODd .498 .638 .402 .277 .214 .193 .225 .270 .403 .234 .572 .293 .492 .3211/2 OD FT18 21 10 9 3 4 3 8 15 6 70 4 24 9HT° C640 595 617 617 690 695 695 695 680 690 615 660 680 640n.sub.D1.519 1.524 1.511 1.518 1.481 1.494 1.494 1.498 1.505 1.493 1.51 1.501 1.505 1.505Wt% 124 125 126 127__________________________________________________________________________SiO.sub.29.5 9.5 9.75 9.31Al.sub.2 O.sub.331.6 31.6 32.4 30.92P.sub.2 O.sub.522.0 22.0 22.6 21.59B.sub.2 O.sub.314.5 14.5 14.8 14.17Li.sub.2 ONa.sub.2 O 1.97 6.73K.sub.2 O12.1 9.98 6.73 13.87MgOCaO 2.8 2.78 2.84 2.72SrOBaO 7.58 7.59 7.78 7.43PbO .05TiO.sub.2ZrO.sub.2ZnOAg.sub.2 O.21 .24 .22 .22CuO .038 .037 .037 .037Cl .38 .40 .27 .39Br .31 .30 .35 .29ODd .403 .335 .167 .5451/2 OD FT15 12 14 45HT° C640 626 627 617n.sub.D1.505 1.508 1.513 1.506Wt% 128 129 130 131 132 133 134 135 136 137 138 139 140__________________________________________________________________________SiO.sub.217.6 17.2 9.6 13.6 16.5 10.1 16.1 21.1 18.4 17.0 16.6 18.7 13.1Al.sub.2 O.sub.329.3 28.6 32.0 28.7 26.7 30.3 27.1 28.8 29.5 27.9 32.8 22.1 32.4P.sub.2 O.sub.511.1 10.8 18.5 13.7 7.9 14.6 14.2 20.9 13.6 14.6 22.9 18.6 22.6B.sub.2 O.sub.317.1 16.7 21.0 16.1 19.5 21.9 14.2 11.8 13.4 13.9 7.0 10.5 11.0Li.sub.2 O1.5 1.5 1.4 1.4 0.66 3.0Na.sub.2 O 3.3 5.7 3.73K.sub.2 O10.5 12.5 5.1 13.3 14.1 5.4 13.7 13.9 9.7 9.7 5.69 12.3 5.1MgOCaO 3.5 3.4 2.8 3.1 3.2 3.2 3.1 .95 3.2 2.9 4.5 2.8SrOBaO 9.5 9.3 7.7 8.3 8.8 8.8 8.6 2.6 14.1 12.3 7.8 12.3 7.8PbOTiO.sub.2 1.26 1.23 .91 0.89ZrO.sub.2 1.95 1.89 1.36HfO.sub.2ZnOAg.sub.2 O0.33 0.33 .31 .40 .29 .33 .26 .20 0.26 0.25 0.22 0.25 .26CuO .035 .035 .036 .029 .036 .037 .03 .038 .03 .03 0.037 .035 .036Cl 0.46 0.45 .48 .45 .44 .47 .49 .48 .57 .58 0.43 0.6 .37Br 0.26 0.25 .38 .27 .26 .39 .30 .27 .28 .26 0.32 0.29 .30ODd .53 .90 .208 1.07 .71 .57 .96 .4 .51 .762 0.26 .642 .2321/2 OD FT15 27 27 36 24 18 60 14 24 18 30 54 6HT° C620 620 700 670 660 680 660 670 630 620 640 610 650n.sub.D1.523 1.522 1.511 1.524 1.528 1.517 1.524 1.518 1.518 1.524 1.519 1.522 1.530Wt% 141 142 143 144 145 146 147 148 149 150 151 152 153__________________________________________________________________________SiO.sub.215.9 17.3 8.5 17.91 18.5 13.57 13.20 9.2 22.21 8.8 9.36 8.5 20.8Al.sub.2 O.sub.328.3 28.3 27.8 13.03 36.5 33.61 29.46 24.5 27.36 28.0 33.98 29.4 28.4P.sub.2 O.sub.520.8 14.9 16.5 21.76 25.5 23.48 14.24 17.7 15.77 17.0 17.98 20.5 20.6B.sub.2 O.sub.39.8 14.1 18.7 16.68 8.0 11.40 17.46 20.1 18.60 19.0 20.35 13.5 11.6Li.sub.2 O1.3 1.4 2.2 3.79 3.04Na.sub.2 O 3.23 6.6K.sub.2 O10.1 11.0 15.0 9.82 9.3 3.22 4.07 18.5 14.61 12.1 4.91 12.2 11.4MgO 1.44CaO 3.3 2.6 2.85 3.13 2.7 2.2 2.73 4.24SrOBaO 11.9 8.9 16.0 20.08 8.08 15.40 7.4 16.7 7.46 11.6PbO .5TiO.sub.2 .92ZrO.sub.2 1.30HfO.sub.2ZnOAg.sub.2 O.26 .24 .24 0.12 .29 .35 .31 .27 .12 .23 .25 .19 .26CuO .032 .032 .032 0.03 .037 .03 .03 .035 .03 .035 .03 .038 .037Cl .42 .46 .58 0.43 .23 .44 .44 .62 .38 .79 .24 .49 .32Br .29 .26 .48 0.41 .19 .36 .34 .55 .31 .44 .32 .29 .25ODd .622 .646 .959 0.315 .11 .108 .403 .721 .09 .83 .08 .621 .4531/2 OD FT27 27 185 18 4 3 12 72 3 21 2 210 30Ht° C640 580 585 680 700 660 660 610 690 660 660 700 710n.sub.D1.521 1.523 1.521 1.492 1.505 1.482 1.525 1.520 1.490Wt% 154 155 156 157 158 159 160 161 162 163 164 165 166__________________________________________________________________________SiO.sub.29.5 17.3 17.1 16.3 14.1 14.4 9.4 12.0 13.3 17.3 17.2 13.6 13.1Al.sub.2 O.sub.326.1 30.7 30.4 29.0 27.3 27.5 26.0 26.4 27.4 28.4 27.0 28.7 32.5P.sub.2 O.sub.516.7 14.9 14.7 14.0 12.2 19.9 16.7 19.1 17.6 14.9 14.8 13.7 22.7B.sub.2 O.sub.320.5 14.2 14.0 13.3 19.8 17.8 20.4 19.3 17.6 14.2 14. 16.1 11.1Li.sub.2 O 2.1 2.1 1.3 1.7 1.4 .66Na.sub.2 O 3.6 2.1 2.8 3.71K.sub.2 O13.1 8.8 9.8 9.3 13.2 5.4 13.1 10.4 9.5 9.9 9.8 13.3 5.64MgOCaO 3.0 3.3 3.2 3.1 3.0 3.0 2.9 3.2 3.3 3.1 2.9SrOBaO 8.2 8.9 8.8 16.8 8.4 8.3 8.2 7.9 8.6 12.5 12.5 8.3 7.8PbOTiO.sub.23.0 2.54 .95 1.20ZrO.sub.2 .68 1.84HfO.sub.2ZnOAg.sub.2 O.39 .28 .25 .25 .27 .25 .30 .26 .35 .27 .30 .50 .23CuO .034 .036 .037 .033 .034 .037 .035 .039 .037 .030 .030 .029 .037Cl .51 .55 .44 .38 .60 .47 .43 .40 .53 .40 .50 .40 .49Br .53 .32 .26 .26 .32 .40 .25 .36 .29 .24 .30 .25 .40ODd .662 .403 .581 .736 .637 .12 .687 .29 .55 .568 .551 1.0 .4371/2 OD FT18 12 24 114 30 5 12 12 21 18 24 36 10HT° C660 610 590 610 665 640 670 640 670 585 655 620 585n.sub.D1.523 1.523 1.523 1.523 1.524 1.509 1.522 1.508 1.512 1.520 1.523 1.524 1.514Wt% 167 168 169 170 171 172 173__________________________________________________________________________SiO.sub.213.8 21.4 9.57 9.91 9.5 8.9 8.9Al.sub.2 O.sub.330.9 29.3 25.30 31.94 26.3 25.5 19.2P.sub.2 O.sub.514.9 21.1 18.46 11.15 16.7 14.3 17.2B.sub.2 O.sub.318.3 12.0 20.74 21.48 20.6 19.2 22.3Li.sub.2 O2.1 0.7Na.sub.2 OK.sub.2 O7.7 14.0 13.27 13.69 16.5 12.3 12.4MgO 1.4 1.31CaO 3.3 3.04 3.14 2.8 2.8 2.8SrOBaO 8.97 8.32 8.58 7.6 16.97 17.1PbOTiO.sub.2ZrO.sub.2HfO.sub.2ZnOAg.sub.2 O.26 .24 .24 .32 .25 .20 .29CuO .04 .037 .037 .037 .035 .032 .035Cl .45 .25 .53 .48 .40 .54 .43Br .29 .18 .36 .28 .31 .33 .40ODd .371 .651 .378 .928 .89 .903 .5451/2 OD FT8 36 12 24 14 38 18HT° C690 630 630 640 635 650 600n.sub.D1.524 1.486 1.507 1.515 1.505 1.526 1.522__________________________________________________________________________
The following Table II lists a series of photochromic glass compositions according to the invention which can be chemically toughened by ion exchange as mentioned above with the compressive stress in pounds per square inch and depth of penetration in microns achieved when the ion exchange is carried out by immersion for 16 hours in a molten KNO 3 bath at 470° C, as well as the photochromic properties of the toughened glasses. In the case of glasses 174, 175 and 178, the exchange is of potassium ions for sodium ions. In glass 176, potassium ions are exchanged for sodium and lithium ions. In glasses 177 and 179, potassium ions are exchanged for lithium ions. It can be seen that the chemical toughening process does not affect the photochromic properties, e.g. by comparing the properties of glass 174 with the very similar glass 71 in Table I.
TABLE II______________________________________ Glass No.Wt% 174 175 176 177 178 179______________________________________SiO.sub.2 22.3 10.7 12.0 13.1 15.0 15.5Al.sub.2 O.sub.3 30.5 35.6 32.1 32.4 28.1 27.5P.sub.2 O.sub.5 22.1 24.8 21.7 22.6 17.6 20.2B.sub.2 O.sub.3 12.5 16.3 14.3 11.0 11.6 9.5Li.sub.2 O 1.83 2.0 1.3Na.sub.2 O 11.1 4.5 1.4 6.1K.sub.2 O 6.8 5.8 8.3 9.3 9.8MgO 1.45 1.35CaO 2.9 2.9 2.7SrOBaO 8.0 7.8 7.4 16.2PbO .5ZrO.sub.2 1.29TiO.sub.2 .84Ag.sub.2 O .31 .28 .25 .20 .28 .27CuO .048 .036 .037 .037 .037 .035Cl .25 .28 .45 .38 .52 .50Br .25 .29 .34 .34 .35 .28Stress 24100 21400 47400 23800 44500 33900(p.s.i.)Penetration 55 85 28 76 60 65(μ)ODd 0.228 0.135 0.14 0.234 1.1 0.5361/2 ODft 4 4 4 15 20 35______________________________________
The compositions listed in the Tables can be made up in the following manner. The batch is melted under oxidising or neutral conditions at a temperature in the range 1200° to 1600° C, and after cooling is annealed at a temperature between 450° and 650° C. A final heat treatment may subsequently be effected at between 20° and 100° C above the annealing point for a period of 10 to 60 minutes. The optimum heat treatment temperature range for a particular glass may be determined by a gradient furnace technique. In some cases, it may be necessary to support the glass during heat treatment to avoid sagging.
The batches can be made up from conventional glassmaking raw materials, such as carbonates, meta-or ortho phosphate, nitrates and oxides. The silver and halide components may be added to the batches in the form of finely-ground silver salts and sodium or potassium halides, respectively.
Precautions are required during melting to minimise volatilisation losses of batch components. Up to 60% by weight of the halide components and 30% by weight of the silver may be lost in this way and the necessary allowances are required during batch preparation.
The glasses disclosed above have a useful combination of photochromic effect, measured as induced optical density, with speed of response to exposure to, or removal of, actinic radiation. Although in some glasses it will be seen that the induced optical density is not high, the speed of response in those glasses is particularly rapid. The glasses can be used for ophthalmic purposes and for other applications where temporary protection from actinic radiation such as sunlight is required with a return to normal transmission when the actinic radiation is absent. They may thus be used for glazing in buildings or vehicles in some circumstances.
The production of photochromic properties in a glass is associated with the formation of silver halide crystals in the glass matrix in a form in which they are sensitive to actinic radiation. Hence the glass maker is not only faced with the problem of choosing a glass composition which can be melted and formed satisfactorily in a particular commercial process, but also the problem of achieving this in a glass in which silver halide crystals will be produced in radiation-sensitive form, so as to give the glass satisfactory photochromic properties. Many suggestions have been made to explain the behaviour of the silver halide crystals in the glass matrix, and British patent specification No. 1,428,880 even suggests that in some circumstances and with certain phosphate glass compositions, the silver halide may be present in the glass matrix in non-crystalline segregation phases.
In view of the large number of components it is possible to incorporate in a glass composition, it is in practice impossible to investigate fully all the permutations and combinations of even a selected area of glass compositions such as is defined in a patent application for a simple glass composition not involving the behaviour of further additives. The problem is increased in the case of compositions where a further physical effect is produced by the addition of other additives, such as those of the present invention. We have made a large number of glasses in the course of our investigation of the composition area claimed in this application. In the examples selected from this work and listed in the Tables above to illustrate our invention, we have in particular illustrated the wide variation in composition which is possible within the defined area in terms of the major glass forming components Al 2 O 3 , B 2 O 3 and P 2 O 5 . We have illustrated how, with this wide variation, glasses can be obtained with a good combination of induced optical density on irradiation with actinic light coupled with rapid darkening on irradiation and rapid fading when irradiation ceases.
As indicated above, we prefer to operate with Al 2 O 3 as the major component. Examples are included to illustrate this for varying relationships of B 2 O 3 to P 2 O 5 , i.e. from B 2 O 3 greater than P 2 O 5 to B 2 O 3 equivalent to P 2 O 5 , and on to where P 2 O 5 is greater than B 2 O 3 . We have also provided examples to indicate that it is feasible to make suitable glasses with either B 2 O 3 or P 2 O 5 as the major component. The examples further illustrate the possible variations within these ranges, i.e. B 2 O 3 >Al 2 O 3 >P 2 O 5 and B 2 O 3 >P 2 O 5 >Al 2 O 3 , and P 2 O 5 >Al 2 O 3 >B 2 O 3 and P 2 O 5 >B 2 O 3 >Al 2 O 3 .
The level of SiO 2 in the composition has little or no effect on the photochromic properties of the glass but does enable one to adjust the forming properties of the glass, and can, for example, be important in achieving a glass which can be easily toughened by chemical means. Hence the adjustment of silica level to accommodate changes in the other major components (Al 2 O 3 , P 2 O 5 , B 2 O 3 ) is a matter of applying the ordinary skill of the glassmaker, and the knowledge of the known effects on a glass composition of such changes.
Examples are provided in Table I to exemplify the limits of the permissible ranges for the major components, but in addition examples of glasses in which the major components are not at the limits of ranges are included to help to guide the practical glass maker to those areas where the most useful glasses can be obtained and to indicate that a large number of glasses exist and have been tested to identify and prove the valuable compositional area which is the basis of this invention. The Examples are in no way intended to establish discrete areas within our broad disclosure in which the advantages of our invention are obtained but to demonstrate that glass compositions may be selected over the total area with a particular preference for selecting glasses in which Al 2 O 3 is the major component. The selection of a suitable base glass composition must also be accompanied by selection of appropriate quantities of the photochromic additives, Ag 2 O, CuO, Cl and Br. The possibility of varying the quantities of these additives in the same base composition is demonstrated in, e.g. Examples 43 to 49. Other variations in this composition are shown in Examples 7, 8, 9, 57 and 58. It will be seen that, in general, with an increase in the level of Ag 2 O there is an increase in induced optical density. It is therefore important in selecting a suitable base glass composition also to experiment with and adjust the level of photochromic additives to give a desired induced optical density in any particular glass.
As mentioned above, a final heat treatment may be effected, and there may be with some compositions a need to investigate the effect of changes in both the time and temperature of the heat treatment to cause the separation of silver halide crystals in the glass matrix so as to achieve an optimum performance from the particular glass. This can be conveniently done using a sample rod of the glass cast in a gradient furnace. Examples showing a variation in heat treatment temperature with some variation in photochromic additives while maintaining almost the same base glass composition include Examples 12, 50 to 56, 59 to 61, and 72 to 74.
Further adjustments may be needed in the level of photochromic additives and the conditions for heat treatment if a composition is further adjusted by composition changes to give a desired refractive index such as 1.523. The adjustment of a glass to the standard ophthalmic refractive index of 1.523 ± 0.001 can be seen to be feasible with the glasses of the present invention. The majority of our Examples in Table I where the index is or has been corrected to 1.523 ± 0.001 are in the area where Al 2 O 3 is the major component in the composition, as this is the area where the combination of properties achieved has been found most advantageous for commercial scale production of ophthalmic glasses, but it will be seen that Example 173 also has such a refractive index in a glass composition in which B 2 O 3 is the major component. | Fast-response alumino-phosphate photochromic glasses having silver halide crystals dispersed throughout the glass consisting essentially of, in weight percentages:
SiO 2 : 8.5 to 25%, Al 2 O 3 : 13 to 36.5%, P 2 O 5 : 7.5 to 33.5%, B 2 O 3 : 7 to 28%; R 2 O: 7 to 20.5%, R'O:0 to 21%, TiO 2 : 0 to 6%, ZrO 2 : 0 to 10%, PbO:0 to 8%,
Where R 2 O represents at least one of Na 2 O, K 2 O and Li 2 O, the maximum content of Li O being 5%; and R'O represents at least one of MgO,CaO,SrO and BaO, within the following individual limits: MgO: 0 to 4%, CaO: 0 to 6.5%, SrO: 0 to 10%, BaO: 0 to 21%; the amount of SiO 2 is not less than 16% when the B 2 O 3 content is less than 8%; and the silver content of the glass, expressed as Ag 2 O, is not less than 0.05% by weight.
Such glasses in which Al 2 O 3 is the largest constituent are preferred for ophthalmic purposes, but it is also possible for either B 2 O 3 or P 2 O 5 to be the largest constituent. The refractive index can be corrected to n D = 1.523. | 2 |
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