Racing bicycle having a continuously variable traction drive

• US 4,735,430 A
• Filed: 08/14/1987
• Issued: 04/05/1988
• Est. Priority Date: 11/13/1984
• Status: Expired due to Fees

• Current Assignee: Philip Tomkinson
• Original Assignee: Philip Tomkinson
• Inventors: Tomkinson, Philip
• Primary Examiner(s): Love, John J.
• Assistant Examiner(s): McGiehan, Donn
• Application Number:
  US07/086,179
• Time in Patent Office: 235 Days
• Field of Search: 280/236, 280/238, 280/260, 74/200, 74/201
• US Class Current: 280/236
• CPC Class Codes: B62K 3/005 Recumbent-type bicycles
• CPC Class Codes: B62K 3/02 Frames tandem frames B62K3/14
• CPC Class Codes: B62M 11/12 with frictionally-engaging wheels B62M11/14 takes precedence
• CPC Class Codes: F16H 15/38 with two members B having hollow toroid surfaces opposite to each other, the member or members A being adjustably mounted between the surfaces

Abstract

A low-drag bicycle comprising an elongated, two piece, generally tubular frame of elliptical cross-section extending between the front and rear wheels wherein the cyclist assumes a recumbent position over the frame facing down and powers the cycle by means of a pedal arrangement directly connected to and concentrically arranged with the rear wheel axle, which axle constitutes the input shaft of a continuously variable compound traction drive transmission for driving the rear wheel hub.

Claims

1. A streamlined bicycle especially adapted for racing purposes, comprising:

a steerable front wheel assembly including a front wheel;

a rear wheel assembly including a rear wheel and axle;

an elongated frame having a front end to which is connected the front wheel assembly and having a rear end to which is connected the rear wheel assembly;

the frame including means for supporting a rider in a head-forward, recumbent position over the frame;

a rotary pedal assembly located at the rear portion of the frame so that the pedals are engaged by the feet of the rider when in said recumbent position;

power transmission means for transmitting power from the pedal assembly to the rear wheel assembly to propel the bicycle;

said power transmission means being located within and constituting a portion of said rear wheel assembly;

said rear wheel assembly including a hub and said power transmission means being sealingly encapsulated within said hub;

said pedal assembly including an input shaft concentric with said hub and constituting the axis of rotation for said hub and means for driving said power transmission means, pedal crank member being located at opposite ends of said input shaft whereby the power transmission means is directly driven by the rider rotating the pedal assembly; and

said power transmission means including a continuously variable compound traction drive transmission whereby over a set speed ratio range the output speed at the rear wheel may be infinitely varied while the rider maintains a constant speed at the pedal assembly.

2. The bicycle of claim 1 wherein:

said power transmission including in combination an input shaft, an output shaft, a primary traction drive system and a secondary drive system, and a cage encapsulating said combination, and

said input shaft being concentric with said rear wheel assembly and extending throughout the axial extent of said rear wheel assembly and adapted to receive a rotary input force at either end thereof from said pedal assembly.

3. The bicycle of claim 2 wherein:

said primary traction drive system including an input toroid having a drive torodial race, an output toroid having a driven torodial race, and traction roller means between and engaging said races for transmitting power to the output toroid, and speed adjustment means for adjusting the position of said traction roller means relative to said races and thereby vary the speed ratio between said races; and

said output toroid being fixed to said secondary drive system, and said secondary drive system having a fixed drive ratio.

4. The bicycle of claim 3 wherein:

said traction roller means comprising at least one roller, said roller being rotatably mounted on a roller carrier, said speed adjustment means including means for fixing the ends of said roller carrier such that it may be at least partially rotated about an axis perpendicular to the axis of rotation of said roller; and

said speed adjustment means further including a lever fixed to said carrier, means carried on said cage for causing limited movement of said lever about the axis of said roller carrier whereby the relative angle of inclination between said roller and the said drive and driven race may be infinitely varied within fixed limits to thereby permit a continuously variable drive ratio within said primary traction drive system.

5. The bicycle of claim 3 wherein:

said secondary drive system comprising a planetary gear unit including a ring gear having a drive race, a sun gear having a driven race, and a planetary set of gears therebetween for transferring drive therethrough at a fixed drive ratio, said sun gear being said output shaft, and said output shaft being fixed to said hub for driving said rear wheel assembly; and

said output toroid of said primary traction drive system and said ring gear of said secondary drive system being a single, integral unit.

6. A streamlined, two-wheeled bicycle, comprising:

a steerable front wheel assembly including a front wheel;

a rear wheel assembly including a rear wheel and axle;

an elongated frame having a front end to which is connected the front wheel assembly and having a rear end to which is connected the rear wheel assembly;

said frame consisting of a front frame member having said front end and a rear frame member having said rear end, each said frame member being in the general shape of an elongated tube, one such frame member having an end portion telescopically received relative to the other frame member and frame locking means for fixedly adjusting the frame members together thereby allowing one to adjust at will the overall length of the bicycle;

support means mounted on said frame for supporting a rider in a head-forward, recumbent position over the frame, said support means comprising a body support fixed to and extending upwardly of said frame, said body support including a body support frame and a hinge means at the lower end thereof for hingedly securing the body support to the bicycle frame, said body support lying transversely of the bicycle frame and further including a rest extending transversely of and resting upon the bicycle frame thereby holding the upper end of the body support off the bicycle frame when the cyclist is supported thereon in a recumbent position;

a pedal assembly located at the rear portion of the frame so that the pedals are engaged by the feet of the rider when in said recumbent position;

means for transmitting power from said pedal assembly to said rear wheel assembly to propel the bicycle;

said power transmitting means being solely within and constituting a portion of said rear wheel assembly.

7. The bicycle of claim 6 wherein said end portion of said frame member includes a series of spaced holes along the axial extent of said end portion and extending transversely of the longitudinal axis of said end portion, and said other frame member also including at least a single hole extending transversely of the longitudinal axis of said other frame member and aligned with one of said series of spaced holes, said frame locking means extending through at least one pair of said transversely aligned holes in telescoping portions of each said frame member for locking said frame members together.

8. The bicycle of claim 7 wherein said frame locking means includes a locking pin, said locking pin extending through each said frame member such that each end of the locking pin projects outwardly therefrom, each locking pin end including means for holding the locking pin in place.

9. The bicycle of claim 8 wherein said hinge means for the body support includes a single hinge pin located transversely of each said frame member and about which the body support may swing in alignment with each said frame member until arrested thereby;

said single hinge pin and said locking pin being the same pin.

10. The bicycle of claim 6 wherein said body support frame is generally V-shaped as viewed in a plane perpendicular to the axis of said frame members and semi-resilient under the weight of the cyclist;

at least one body support pad connected to said body support at the upper end portions thereof, and said rest being located between said at least one body support pad and said hinge means.

11. The bicycle of claim 6 wherein said frame locking means includes said single securement means for said body support.

12. A streamlined bicycle especially adapted for racing purposes, comprising:

a steerable front wheel assembly including a front wheel;

a rear wheel assembly including a rear wheel and axle;

an elongated frame having a front end to which is connected the front wheel assembly and having a rear end to which is connected the rear wheel assembly;

the frame including means for supporting a rider in a head-forward, recumbent position over the frame;

a rotary pedal assembly located at the rear portion of the frame so that the pedals are engaged by the feet of the rider when in said recumbent position;

power transmission means for transmitting power from the pedal assembly to rear wheel assembly to propel the bicycle;

said power transmission means being located within and constituting a portion of said rear wheel assembly;

said rear wheel assembly including a hub and said power transmission means being sealingly encapsulated within said hub;

said power transmission means including a continuously variable compound traction drive transmission whereby over a set speed ratio range the output speed at the rear wheel may be infinitely varied while the cyclist maintains a constant speed at the pedal assembly;

said power transmission including in combination an input shaft, an output shaft, a primary traction drive system and a secondary drive system, and a cage encapsulating said combination;

said input shaft being concentric with said rear wheel assembly and extending throughout the axial extent of said rear wheel assembly and adapted to receive a rotary input force at either end thereof from said pedal assembly;

said primary traction drive system including an input toroid having a drive torodial race, an output toroid having a driven torodial race, and traction roller means between and engaging said races for transmitting power to the output toroid, and speed adjustment means for adjusting the position of said traction roller means relative to said races and thereby vary the speed ratio between said races;

said output toroid being fixed to said secondary drive system, and said secondary drive system having a fixed drive ratio; and

said speed adjustment means further including a drum concentrically mounted on said cage, actuating means connected to said drum for rotating said drum relative to said cage, said drum including a slot extending diagonally to the axis of rotation of said drum, said cage including a slot extending axially to the axis of rotation of said cage.

13. The bicycle of claim 12 wherein:

said lever extends from said roller carrier through each of said slots whereby upon rotation of said drum relative to said cage the angle of inclination of said roller will cause a change in the speed ratio of the primary traction drive system.

14. A continuously variable compound light duty traction drive transmission adapted for use in a bicycle or similar light duty, low torque applications comprising:

in combination an input shaft, an output shaft, a primary traction drive system and a secondary drive system, and a cage encapsulating said combination; and

said input shaft being concentric with said output shaft and said cage adapted to receive a rotary input force at either end thereof;

said primary traction drive system including an input toroid having a drive torodial race, an output toroid having a driven torodial race, and traction roller means between and engaging said races for transmitting power to the output toroid, and speed adjustment means for adjusting the position of said traction roller means relative to said races and thereby vary the speed ratio between said races;

said speed adjustment means further including a drum concentrically mounted on said cage, actuating means connected to said drum for rotating said drum relative to said cage, said drum including a slot extending diagonally to the axis of rotation of said drum, said cage including a slot extending axially to the axis of rotation of said cage, and means riding within said slots and connected to said traction roller means whereby upon rotation of said drum the angular position of the traction roller means relative to the input and output toroid will be changed.

15. The continuously variable compound light duty traction drive transmission of claim 14 wherein:

said traction roller means comprises at least one roller, said roller being rotatably mounted on a roller carrier, said speed adjustment means including means for fixing the ends of said roller carrier such that it may be at least partially rotated about an axis perpendicular to the axis of rotation of said roller;

said means comprising a lever extending from said roller carrier through each of said slots whereby upon rotation of said drum relative to said cage the angle of inclination of said roller will cause a change in the speed ratio of the primary traction drive system.

16. A continuously variable compound light duty traction drive transmission adapted for use in a bicycle or similar light duty, low torque applications comprising:

in combination an input shaft, an output shaft, a primary traction drive system and a secondary drive system, and a cage encapsulating said combination; and

said input shaft being concentric with said output shaft and said cage adapted to receive a rotary input force at either end thereof;

said primary traction drive system including an input toroid having a drive torodial race, an output toroid having a driven torodial race, and traction roller means between and engaging said races for transmitting power to the output toroid, and speed adjustment means for adjusting the position of said traction roller means relative to said races and thereby vary the speed ratio between said races;

said secondary traction drive system comprising a planetary gear unit including a ring gear having a drive race, a sun gear having a driven race, and a planetary set of gears therebetween for transferring drive therethrough at a fixed drive ratio, said output toroid of said primary traction drive system being fixed to said ring gear, and said sun gear being said output shaft, and said output shaft being fixed to said hub for driving said rear wheel assembly or the like.

17. The light duty traction drive transmission of claim 16 wherein:

said speed adjustment means further including a drum concentrically mounted on said cage, actuating means connected to said drum for rotating said drum relative to said cage, said drum including a slot extending diagonally to the axis of rotation of said drum, said cage including a slot extending axially to the axis of rotation of said cage.

18. The light duty traction drive tranmission of claim 16 wherein:

said traction roller means comprises at least one roller, said roller being rotatably mounted on a roller carrier, said speed adjustment means including means for fixing the ends of said roller carrier such that it may be at least partially rotated about an axis perpendicular to the axis of rotation of said roller; and

said speed adjustment means further including a lever fixed to said carrier, means carried on said cage for causing limited movement of said lever about the axis of said roller carrier whereby the relative angle of inclination between said roller and the said drive and driven race may be infinitely varied within fixed limits to thereby permit a continuously variable drive ratio within said primary traction drive system.

19. The light duty traction drive transmission of claim 18 wherein:

said speed adjustment means further including a drum concentrically mounted on said cage, actuating means connected to said drum for rotating said drum relative to said cage, said drum including a slot extending diagonally to the axis of rotation of said drum, said cage including a slot extending axially to the axis of rotation of said cage; and

said lever extending from said roller carrier through each of said slots whereby upon rotation of said drum relative to said cage the angle of inclination of said roller will cause a change in the speed ratio of the primary traction drive system.

20. The continuously variable compound light duty traction drive transmission of claim 16 wherein:

said output toroid of said primary traction drive system and said ring gear of said secondary drive system are a single, integral unit.