Simple, compact and effective self-extending and retracting bicycle crank arm
OwnerEric Kam-Ling Hunginventor
Life of this patent
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Abstract
This invention is a bicycle crank and pedal assembly with a self-extending and retracting crank arm. The assembly only has three one-piece components that move relative to each other, if the bearings used in friction reduction are ignored. It is simple in design, compact in size and very effective in delivering the benefits of a self-extending and retracting crank arm. In particular, the assembly has (a) the maximum arm length for over 90 degrees of arm directions in the power down stroke and (b) the minimum arm length for close to 90 degrees of arm directions in the return up stroke.
Claims9
A bicycle crank and pedal assembly with a self-extending and retracting crank arm;
- said assembly comprising:
- a crank arm with a plate cavity, a bar track, and two slits;
- a bar inside said bar track in said crank arm;
- said bar being fixed to a pedal spindle at one end;
- and
- a plate shaft;
- said plate shaft being fixed to a plate at one end and to a pedal at the other end;
- said plate being inside said plate cavity in said crank arm.
Dependencies are inferred from the claim text.