Claims
- 1. A variable speed drive comprising an output drive, a driver and an endless, extendible member that extends around and is driven by the driver and drives the output drive, wherein the first driver is operable to drive the endless, extendible member at a first speed at a driving position, and a driven brake system for changing a second speed or stopping movement of the endless, extendible member at a driven position, thereby to cause local expansion or contraction of the endless, extendible member around the driver without extending the overall length of the endless, extendible member.
- 2. A drive as claimed in claim 1, wherein the driven brake system is operable to reduce the speed of the endless, extendible member to substantially zero at the driven position, so that the endless, extendible member is substantially prevented from moving past the driven position.
- 3. A drive as claimed in claim 1, wherein the endless, extendible member is an endless coil or spring or a belt or tube.
- 4. A variable speed drive as claimed in claim 3, wherein the endless, extendible member is an endless spring or coil, and the output drive comprises two hollow driven shafts.
- 5. A variable speed drive as claimed in claim 4, wherein the hollow driven shafts power a generator.
- 6. A variable speed drive as claimed claim 4, wherein at least one lug depends from an inner peripheral surface of each hollow driven shaft for placement between adjacent windings of the spring or coil, so that when the endless spring or coil is propelled forward, each hollow driven shaft is rotated by engagement of successive windings of the endless spring or coil with the at least one lug.
- 7. A variable speed drive as claimed in claim 6, wherein the at least one lug is a pair of lugs, each lug of the pair of lugs being between adjacent windings of the endless spring or coil but offset from each other in such a manner that a first one of the pair of lugs contacts a forward one of the adjacent windings and a second one of the pair of lugs contacts a rearward one of the windings.
- 8. A variable speed drive as claimed in claim 6, wherein two or more lugs are provided opposite each other.
- 9. A variable speed drive as claimed in claim 4, wherein sets of lugs are provided at opposing ends of at least one of the two hollow driven shafts.
- 10. A variable speed drive as claimed in claim 4, wherein the two hollow driven shafts each comprise an inner hollow cylindrical shaft that is releasably coupled to an outer hollow cylindrical shaft that drives a generator.
- 11. A variable speed drive as claimed in claim 10, wherein the driven brake system is operable to de-couple one of the inner hollow cylindrical shafts from a corresponding one of the outer hollow cylindrical shafts.
- 12. A variable speed drive as claimed in claim 11, wherein the driven brake system is hydraulically driven.
- 13. A variable speed drive as claimed in claim 11, wherein the driven brake system comprises a braking mechanism for braking movement of the one of the inner hollow cylindrical shafts, thereby to de-couple the one of the inner hollow cylindrical shafts from the corresponding one of the outer hollow cylindrical shafts so that one of the speeds of the endless spring or coil through the one of the inner hollow cylindrical shafts is reduced or brought to zero.
- 14. A variable speed drive as claimed in claim 11, wherein the driven brake system comprises a compression spring that is mounted between one end of the one of the inner hollow cylindrical shafts and one end of the one of the outer hollow cylindrical shafts, wherein the compression spring is operable to pull the one of the inner hollow cylindrical shafts into driven engagement with the one of the outer hollow cylindrical shafts up until a pre-determined tension of the endless spring or coil is reached, at which stage the one of the inner hollow cylindrical shafts is moved out of engagement with the one of the outer hollow cylindrical shafts.
- 15. A variable speed drive as claimed in claim 14, comprising an actuator that is operable to sense when to switch off the output drive and move the one of the inner hollow cylindrical shafts against an action of the compression spring and out of engagement with the one of the outer hollow cylindrical shafts, thereby to de-couple the one of the inner hollow cylindrical shafts from the one of the outer hollow cylindrical shafts.
- 16. A variable speed drive as claimed in claim 15, wherein a detector is provided to detect a loosening of the endless spring or coil and switch off a generator driven by the outer shaft, thereby to return the output drive to a starting position.
- 17. A variable speed drive as claimed in claim 10, wherein the one of the inner hollow cylindrical shafts has two separate but interlocking parts that can move longitudinally apart from each other, each of the parts being releasably mounted in driven engagement with one of the outer hollow cylindrical shafts, wherein the driven brake system includes a driven component for moving the parts of the one of the inner hollow cylindrical shafts from a driven position to a de-coupled position in which the parts of the one of the inner hollow cylindrical shafts are de-coupled from the one of the outer hollow cylindrical shafts.
- 18. A variable speed drive as claimed in claim 17, wherein the driven component is hydraulically driven.
- 19. A variable speed drive as claimed in claim 17, wherein the driven component comprises elliptical wheels that are rotatable into engagement with the parts of the one of the inner hollow cylindrical shafts, thereby to push the parts of the one of the inner hollow cylindrical shafts away from each other and out of driven engagement with the one of the outer hollow cylindrical shafts.
- 20. A variable speed drive as claimed in claim 1, wherein a drive member is provided on the input drive, the endless, extendible member being wound around the drive member.
- 21. A variable speed drive as claimed in claim 20, wherein the drive member is circular.
- 22. A variable speed drive as claimed in claim 20, wherein the drive member is pear shaped.
- 23. A variable speed drive as claimed in claim 1, wherein at least one detector is provided for detecting an expansion or contraction of the endless, extendible member, and thereby changes in a driver speed of the driver.
- 24. A variable speed drive as claimed in claim 23, wherein when the endless, extendible member is a spring, the at least one detector is operable to monitor separation of adjacent windings to thereby gain a measure of expansion or contraction of the spring and a spring speed of the spring.
- 25. A variable speed drive as claimed in claim 24, wherein the at least one detector is two detectors on opposing sides of the driver, and further including a comparator for comparing the separation of the windings to thereby calculate a rate of power transmitted.
- 26. A variable speed drive comprising a driver, an output drive and an endless, extendible member that extends around and is driven by the driver and drives the output drive, wherein the driver is operable to drive the endless, extendible member at a first speed at a driving position, and a driven brake system for changing a second speed or stopping movement of the endless, extendible member at a second position, thereby to cause local expansion or contraction of the endless, extendible member around the driver, wherein the output drive comprises a hollow drive shaft on which is provided a lug for interacting with the endless, extendible member thereby to be moved by it.
- 27. A variable speed drive comprising a driving system, an output drive and an endless, extendible member that extends around and is driven by the driving system and drives the output drive, wherein the driving system comprises a first driver operable to drive the endless, extendible member at a first speed at a first position and a second driver operable to drive the endless, extendible member at a second speed at a second position, thereby to cause local expansion or contraction of the endless, extendible member around the first driver.
- 28. A variable speed drive comprising an input drive, a movable member, an output drive and an endless, extendible member that is driven by the input drive and extends around the input drive and the movable member, wherein movement of the endless, extendible member over the output drive causes the output drive to move and movement of the moveable member expands or contracts the endless, extendible member, thereby varying an overall length of the endless, extendible member to vary a speed at which the output drive is driven, wherein the output drive comprises a hollow driven shaft on which is provided a lug for interacting with the endless, extendible member to move the hollow driven shaft.
- 29. A variable speed drive as claimed in claim 28, wherein the movable member comprises two spaced apart moveable locating members, the endless, extendible member being located between the locating members, the locating members being fixedly mounted relative to each other and movable relative to the output drive such that when the locating members are moved in one direction, the endless, extendible member is caused to engage a first one of the locating members and is able to move a driven shaft in a first direction, and when moved in another direction, the endless, extendible member is caused to engage a second one of the locating members and is able to move the driven shaft in a second direction, thereby to provide a reversible drive.
- 30. A variable speed drive as claimed in claim 28, wherein the movable member comprises a wheel.
- 31. A variable speed drive as claimed in claim 28, wherein the endless, extendible member is a spring or coil.
- 32. A variable speed drive as claimed in claim 31, wherein the lug depends from an internal wall of the hollow drive shaft for placement between windings of the spring or coil, so that when the spring or coil is propelled forward, the hollow drive shaft is rotated by engagement of successive windings with the lug.
- 33. A variable speed drive as claimed in claim 32, wherein two or more lugs are provided.
- 34. A variable speed drive as claimed in claim 33, wherein the lugs are provided with a roller bearing that provides a surface for engagement with the windings of the spring or coil, thereby to reduce friction.
- 35. A variable speed drive as claimed in claim 31, wherein a drive wheel is provided on the input drive, the endless, extendible member being wound around the drive wheel.
- 36. A variable speed drive as claimed in claim 31, wherein a detector is provided for detecting any expansion or contraction of the endless, extendible member, and thereby changes in the speed of the output drive and rate of transmission of power to the output drive.
- 37. A variable speed drive as claimed in claim 36, wherein the detector is operable to monitor separation of adjacent windings of the spring or coil, thereby to gain a measure of expansion or contraction of the spring or coil.
- 38. A variable speed drive as claimed in claim 28, wherein the endless, extendible member is an elastic belt or tube.
- 39. A variable speed drive as claimed in claim 38, wherein the output drive is a linear electric generator.
- 40. A variable speed drive as claimed in claim 39, wherein material is mounted at regularly spaced intervals along a length of the belt or tube, wherein the material is capable of being attracted and/or repelled magnetically.
- 41. A variable speed drive comprising an input drive, a movable member, an output drive and an endless, extendible member that is driven by the input drive and extends around the input drive and the movable member, wherein movement of the endless, extendible member over the input drive causes the input drive to move and movement of the moveable member expands or contracts the endless, extendible member, thereby varying an overall length of the endless, extendible member, and so varying a speed at which the endless, extendible member is driven, wherein the endless, extendible member is an elastic belt or tube with material mounted at regularly spaced intervals along the elastic belt or tube wherein the material is capable of being attracted and/or repelled magnetically and the output drive is a linear electric generator.
- 42. A drive comprising an input drive, an output drive and an endless extendible member driven by the input drive and driving the output drive, in which the extendible member extends around one of the input drive and the output drive, and in which the extendible member extends through the other of the input drive and the output drive such that said other of the input drive and output drive rotates around a circumference of the extendible member.
- 43. A drive comprising an input drive, an output drive and an endless, extendible member extending around and driven by the input drive, in which the endless extendible member extends through the output drive and drives the output drive to rotate around a circumference of the extendible member.
- 44. A generator comprising an input drive, an output drive and an endless, extendible member extending around and driven by the input drive, in which the endless extendible member extends through the output drive and drives the output drive to rotate around a circumference of the extendible member.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9820984.4 |
Sep 1998 |
GB |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of copending patent application Ser. No. 09/815,821, filed on Mar. 23, 2001 entitled VARIABLE SPEED DRIVE, which is a continuation of PCT International Application No. PCT/GB99/03198 filed in the United Kingdom on Sep. 24, 1999 designating the United States of America, which was published in English on Apr. 6, 2000 and which claims priority to British Patent Application No. 9820984.4 filed Sep. 25, 1998.
Continuations (2)
|
Number |
Date |
Country |
Parent |
09815821 |
Mar 2001 |
US |
Child |
10313725 |
Dec 2002 |
US |
Parent |
PCT/GB99/03198 |
Sep 1999 |
US |
Child |
09815821 |
Mar 2001 |
US |