Propulsion mechanism for lever propelled bicycles
First Claim
1. A propulsion mechanism for a lever propelled bicycle having a frame with main and rear shaft receiving portions, pedal lever assemblies including speed change devices, said assemblies being pivotally mounted in said main shaft portion, a rear axle mounted in said rear shaft portion, a rear wheel hub journalled on said rear axle, a pair of sprockets also journalled on said rear axle, a pair of one-way clutches for connecting said sprockets to said hub, said propulsion mechanism being characterized in that:
- a chain of flexible material is entrained in a loop extending between each of said lever assemblies'"'"' speed change devices and around said sprockets enabling the pedal levers to execute see-saw motion as said levers are oscillated upwardly and downwardly by force applied to the pedals thereof;
a pair of pawl and ratchet mechanisms is provided in each of said one-way clutches, one of which effects locking of the clutch to impart forward motion when said pedal levers are depressed downwardly and the other of which effects release of said clutch to enable said bicycle to be rolled backwards; and
each of said speed change devices having a housing having a surface extending away from said main shaft to define the length of the lever arm of said pedal lever assemblies to said main shaft, a plurality of pawls pivotally mounted in said housing to move transversely to said surface and define a plurality of locations each at a different lever arm length, a speed selection bar for pivoting said pawls, and a link connected to an end of the chain and moveable along said surface between different ones of said locations.
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Accused Products
Abstract
A bicycle having pivoted lever pedal system (1, 2, 45) and lever arm length or gear ratio (speed) change devices (3, 4, 5, 6). Propulsion forces from the lever pedals (1) are transferred via the lever arm length change device (3) through a flexible interconnecting cable and pulley system (7, 8, 9, 10, 11, 12, 13) to a rear drive hub assembly 14 having a pair of one-way clutches which allow the transfer of forward driving forces and enable the bicycle to be rolled back.
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Citations
34 Claims
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1. A propulsion mechanism for a lever propelled bicycle having a frame with main and rear shaft receiving portions, pedal lever assemblies including speed change devices, said assemblies being pivotally mounted in said main shaft portion, a rear axle mounted in said rear shaft portion, a rear wheel hub journalled on said rear axle, a pair of sprockets also journalled on said rear axle, a pair of one-way clutches for connecting said sprockets to said hub, said propulsion mechanism being characterized in that:
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a chain of flexible material is entrained in a loop extending between each of said lever assemblies'"'"' speed change devices and around said sprockets enabling the pedal levers to execute see-saw motion as said levers are oscillated upwardly and downwardly by force applied to the pedals thereof; a pair of pawl and ratchet mechanisms is provided in each of said one-way clutches, one of which effects locking of the clutch to impart forward motion when said pedal levers are depressed downwardly and the other of which effects release of said clutch to enable said bicycle to be rolled backwards; and each of said speed change devices having a housing having a surface extending away from said main shaft to define the length of the lever arm of said pedal lever assemblies to said main shaft, a plurality of pawls pivotally mounted in said housing to move transversely to said surface and define a plurality of locations each at a different lever arm length, a speed selection bar for pivoting said pawls, and a link connected to an end of the chain and moveable along said surface between different ones of said locations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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- 19. A propulsion mechanism for a lever propelled bicycle having a frame with main and rear shaft receiving portions, pedal lever assemblies, said assemblies being pivotally mounted in said main shaft portion, a rear axle mounted in said rear shaft portion, a rear wheel hub journalled on said rear axle, a pair of sprockets also journalled on said rear axle, a pair of one-way clutches for connecting said sprockets to said hub, said propulsion mechanism being characterized in a pairs of pawl and ratchet mechanisms is provided in each of said one-way clutches, one of which effects locking of the clutch to impart forward motion when said pedal levers are depressed downwardly and the other of which effects release of said clutch to enable said bicycle to be rolled backwards.
- 24. In a propulsion mechanism for a lever propelled bicycle having a frame with main and rear shaft receiving portions and having pedal lever assemblies including lever arm length change devices, said assemblies being pivotally mounted in said main shaft portion, a rear axle mounted in said rear shaft portion, a rear wheel hub journalled on said rear axle, at least one sprocket also journalled on said rear axle, a chain around said sprocket for transferring propulsion forces from the devices to said rear wheel hub and enabling the pedal levers to execute see-saw motion as said levers are oscillated upwardly and downwardly by force applied to the pedals thereof the improvement wherein each of said change devices comprises a housing having a surface extending away from said main shaft to define the length of the lever arm of said pedal lever assemblies to said main shaft, a plurality of pawls pivotally mounted in said housing to move transversely to said surface and define a plurality of locations each at a different lever arm length, a speed change bar for pivoting said pawls, and a link connected to an end of the chain and moveable along said surface between different ones of said locations.
- 27. In a propulsion mechanism for a lever propelled bicycle having a frame with main and rear shaft receiving portions and having pedal lever assemblies including lever arm length change devices, said assemblies being pivotally mounted in said main shaft portion, a rear axle mounted in said rear shaft portion, a rear wheel hub journalled on said rear axle, at least one sprocket also journalled on said rear axle, a chain around said sprocket for transferring propulsion forces from the devices to said rear wheel hub and enabling the pedal levers to execute see-saw motion as said levers are oscillated upwardly and downwardly by force applied to the pedals thereof, the improvement wherein each of said change devices comprises a housing having a surface extending away from said main shaft to define the length of the lever arm of said pedal lever assemblies to said main shaft, a plurality of pawls pivotally mounted in said housing to move transversely to said surface and define a plurality of locations each at a different lever arm length, a speed change bar for pivoting said pawls, a link connected to an end of the chain and moveable along said surface between different ones of said locations, said surface in said housing and said housing defining a longitudinal slot, a member moveable in said slot and linked to one end of said chain, said bar being moveable in said longitudinal direction, said pawls in said housing in said pivots providing pivotal mountings for said pawls intermediate the ends thereof, means on said bar for engaging said pawls at different locations with respect to the pivots thereof for selectively pivoting said pawls in opposite directions to define different ones of said plurality of locations where said member which is linked to said chain is captured.
Specification