Propulsion and speed change mechanism for lever propelled bicycles

• US 4,574,649 A
• Filed: 02/02/1983
• Issued: 03/11/1986
• Est. Priority Date: 03/10/1982
• Status: Expired due to Fees

• Current Assignee: Byung D. Yim
• Original Assignee: B. D. Yim
• Inventors: Seol, Man T.
• Primary Examiner(s): Staab, Lawrence J.
• Application Number:
  US06/463,085
• Time in Patent Office: 1,133 Days
• Field of Search: 74/833, 74/138, 74/141, 74/142, 74/150, 74/151, 192/28, 192/48.92, 192/64, 192/42, 280/243, 280/246, 280/251, 280/253, 280/255, 280/258
• US Class Current: 74/138
• CPC Class Codes: B62M 1/28 characterised by the use of flexible drive members, e.g. chains
• CPC Class Codes: B62M 9/04 of changeable ratio
• CPC Class Codes: Y10T 74/1547 Single acting
• CPC Class Codes: Y10T 74/1555 Rotary driven element
• CPC Class Codes: Y10T 74/1642 Device driven from selected points on oscillating link
• CPC Class Codes: Y10T 74/2164 Cranks and pedals

Abstract

Propulsion and speed change mechanism for lever propelled bicycles having a pair of propulsion levers 4, each of which is built in one piece with a speed change arm 3 and mounted in each side of the main shaft portion 2 at the bottom of the bicycle frame 1. A rear axle 5 and a hub 6 is mounted on the rear shaft portion 2'"'"'. A one-way clutch mechanism has roller-type free wheels 11a installed at both ends of the rear axle. Chains 7", the ends of which may be connected together with a see-saw cable 7'"'"', are entrained around gears 7 and guide rollers 13. The free ends of the chains are connected by connecting bars 14 having pins to the speed change arm 3. Pivotally mounted members 15 of triangular shape and a cam bar 17 operated by a speed control knob 18 are used to change the effective length of the arm for speed control.

Claims

1. A propulsion mechanism for a lever propelled bicycle having a frame with a main shaft portion and a rear shaft portion disposed rearwardly of said main shaft portion on said frame, said mechanism comprising a pair of propulsion levers for receiving pedals, a pair of arms, a journal, said journal, said levers and said arms being a one piece assembly with one of said pair of levers and one of said pair of arms spaced from the other of said pair of levers and the other of said pair of arms, said one piece assemble being pivotally mounted on said main shaft portion, a rear axle attached to said rear shaft portion, a rear wheel hub journaled on said rear axle, a pair of chain gears spaced from each other and journaled on said rear axle, a pair of one-way clutches connecting said chain gears to said rear wheel hub, a chain entrained on said chain gears, and means connecting said chain to said arms to execute see-saw motion as said levers and arms are oscillated upwardly and downwardly by force supplied to said pedals said pair of one-way clutches allowing free counterclockwise rotation of said rear wheel hub, and each one-way clutch comprising a drum having a latch and pawl in the shape of the Greek Letter lambda, a notch in said rear wheel hub for releasably receiving said latch and a free wheel means having a drum engaging element therein disposed inside said drum, said free wheel means being rotatably mounted on said rear axle and being releasably engagable with said rear wheel hub.

2. The propulsion mechanism according to claim 1 wherein each of said free wheel means further comprises a cam plate, one of said free wheel means and one of said chain gears also being attached to each other, said cam plate of each of said free wheel means being disposed internally of said drum thereof and having at least one identation facing the internal peripheral surface of said drum, said drum engaging element being a roller being disposed in said indentation, a ratchet gear in said drum, said ratchet gear being fixed to said rear axle, said latch pivotally mounted on said drum and pivotal in a direction radially thereof, said notch in said rear wheel hub for releasably receiving said latch, and said pawl in engagement with said ratchet gear, said pawl being pivotally mounted on said latch for pivoting said latch to bring said latch into and out of said notch depending upon the direction of rotation of said rear wheel and rear wheel hub respectively when said bicycle moves in said forward and rearward directions.

3. A propulsion mechanism for a lever propelled bicycle having a frame with a main shaft portion and a rear shaft portion disposed rearwardly of said main shaft portion on said frame, said mechanism comprising a pair of propulsion levers for receiving pedals, a pair of arms, a journal, said journal, said levers and said arms being a one piece assembly with one of said pair of levers and one of said pair of arms spaced from the other of said pair of levers and the other of said pair of arms, said one piece assemble being pivotally mounted on said main shaft portion, a rear axle attached to said rear shaft portion, a rear wheel hub journaled on said rear axle, a pair of chain gears spaced from each other and journaled on said rear axle, a pair of one-way clutches connecting said chain gears to said rear wheel hub, a chain entrained on said chain gears, and means connecting said chain to said arms to execute see-saw motion as said levers and arms are oscillated upwardly and downwardly by force supplied to said pedals wherein said arms are speed change arms each having a longitudinal edge, said means connecting said chain to said arms including links having pins each moveably disposed on the longitudinal edges of said arms, each said arm having a plurality of members pivotly mounted thereon and disposed in spaced relationship longitudinally along said arm, each of said members being pivotally moveable below and above said longitudinal edge of said arm for releasable engagement of said pin therewith, each said arm having a bar moveable longitudinally of said arm, said bar having a plurality of means successively engageable with a different one of said members along the edge thereof opposite to said one edge to define separate cams, said successively engageable means being spaced longitudinally along said bar for successively bringing said members into engagement with said pins for changing the effective length of said arms.

4. The propulsion mechanism according to claim 3 wherein each of said members have a notch along one edge thereof in which said pin is releasably engaged, said successively engagable means being a plurality of projections each of which is engagable with a different one of said members along said opposite edge thereof for successively camming different ones of said members below and above said longitudinal edge to bring said notches into engagement with said pins for changing the effective length of said arms.

5. The propulsion mechanism according to claim 3 further comprising speed control means on said frame and attached to said bars for moving said bars.

6. The propulsion mechanism according to claim 4 wherein said members are generally triangular in shape, having three sides.

7. The propulsion mechanism according to claim 6 wherein said arms have elongated slots therein extending longitudinally thereof, said one edge of said triangular being defined by two of said three sides of said triangular members, said notch being at the apex of said two sides, said opposite edge of said members being the third side of said triangle, said third side facing the bottom of said slot, said bar being disposed between said third side and said bottom, and said members being pivotally mounted near the apex thereof defined by said third side and one of said two sides.

8. The propulsion mechanism according to claim 3 further comprising springs biasing said members into operating engagement with said bar, and spring arms biasing said bars for movement in one direction longitudinally along said arm.

9. The propulsion mechanism according to claim 8 further comprising a speed change knob and cables connecting said knob to said bars to allow movement of said bars longitudinally in one direction under said bias or in an opposite direction against said bias.

10. The propulsion mechanism according to claim 3 wherein said successively engagable means is a plurality of members at least equal in number to said plurality of pivotal members.

11. The propulsion mechanism according to claim 3 wherein each of said arms has said pivotal members disposed inside thereof in a row, said bars also being disposed inside said arms under said members, control cables, speed change means connected to said bars by said control cables whereby upon operating said speed change means selected ones of one said pivotal members are moved out of said arm to raise them above said longitudinal edges of said arms to enable said pin on said link to be caught thereby.

12. A speed change mechanism for a lever propelled bicycle having a pedal lever and a speed change arm mounted about a pivot for oscilating movement, a chain in driving relationship with a wheel of said bycicle, said arm having an edge extending from said pivot longitudinally thereof, said speed change mechanism including link means having a pin moveably disposed on said longitudinal edge of said arm, said arm having a plurality of members pivotly mounted thereon and disposed in spaced relationship longitudinally along said arm, said members being engagable with said pins and being pivotally moveable below and above said edge of said arm for releaseable engagement of said pins therewith, said arm having a bar moveable longitudinally of said arm, said bar having a plurality of means successively engageable with different ones of said members, said successively engagable means being spaced longitudinally along said bar for successively moving different ones of said members below and above said edge of said arm to bring said members into engagement with said pin for changing the effective length of said arm.

13. The invention according to claim 12 wherein each of said pivotal members has a notch along one edge thereof for releaseable engagement of said pins therewithin, said plurality of means successively engagable with different ones of said members being a plurality of projections on said bar, said projections being engagable with said members along the edges thereof opposite to said one edge to define separate cams, said projections being spaced longitudinally along said bar for successively engaging different ones of said members below and above said edge of said arm to bring said notches into engagement with said pin for changing the effective length of said arm.

14. The invention according to claim 12 further comprising speed control means on said frame and attached to said bars for moving said bars.

15. The invention according to claim 13 wherein said members are generally triangular in shape having three sides.

16. The invention according to claim 15 wherein said arms have elongated slots therein extending longitudinally thereof, said one edge of said triangular members being defined by two of said sides of said triangular members, said notch being at the apex of said two sides, said opposite edge of said members being the third side of said triangle, said third side facing the bottom of said slot, said bar being disposed between said third side and said bottom, and said members being pivotally mounted near the apex thereof defined by said third side and one of said two sides.

17. The invention according to claim 16 further comprising springs biasing said members to bring said third sides into engagement with said bar, and spring arms biasing said bars for movement in one direction longitudinally along said arm.

18. The invention according to claim 12 further comprising a speed change knob and cables connecting said knob to said bars to allow movement of said bars longitudinally in one direction under said bias or in an opposite direction against said bias.

19. The invention according to claim 13 wherein said plurality of projections is at least equal in number to said plurality of notched members.

20. The invention according to claim 12 wherein each of said arms has said pivotal members disposed inside thereof in a row, said bars also being disposed inside said arms under said members, control cables, speed change means connected to said bars by said control cables whereby upon operating said speed change means selected ones of one said pivotal members are moved out of said arm to raise said one edges thereof at least in part above said longitudinal of edges of said arms to enable said pin on said link to be caught by said members.

21. In a system having an axle and a hub journaled on said axle, a one-way clutch allowing free counterclockwise rotation of said hub comprising a drum having a latch and pawl in the shape of the Greek Letter lambda, a notch in said hub for releasably receiving said latch and a free wheel means having a drum engaging element therein disposed inside said drum, said free wheel means being rotatably mounted on said axle and being releasably engagable with said hub.

22. The propulsion mechanism according to claim 21 wherein said free wheel means further comprises a cam plate, said cam plate of said free wheel means being disposed internally of said drum thereof and having at least one identation facing the internal peripheral surface of said drum, said drum engaging element being a roller being disposed in said indentation, a ratchet gear in said drum, said ratchet gear being fixed to said axle, said latch pivotally mounted on said drum and pivotal in a direction radially thereof, said notch in said hub for releasably receiving said latch, and said pawl in engagement with said ratchet gear, said pawl being pivotally mounted on said latch for pivoting said latch to bring said latch into and out of said notch depending upon the direction of rotation of said hub when said hub rotates clockwise or counterclockwise.