| 摘要 |
This invention provides a novel solution for an optimally powered crank for a human-powered vehicle, such as a bicycle. This invention includes a novel system and method to optimize the length of each crank arm throughout the revolution of the crank assembly. First, a crank arm assembly is attached to the bicycle's existing spindle assembly. The crank arm assembly includes a rail section that is fixed at one end to the mounting section of the crank arm assembly. Next, the opposite end of the rail section is attached to the sliding section of the crank arm assembly. The sliding section of the crank arm assembly also includes a feature that allows the sliding section to collapse and expand along the rail section. The crank arm assembly also includes at least two track rollers mounted to the side of each sliding section designed to reduce friction and counter inertial forces associated with the crank arm assembly sliding along the tracks. Next, the assembly includes two tracks mounted on each side of the frame. The tracks are used to control the length of the crank arms at each angular position. Finally, the shape of each track is designed to coincide with the optimum crank arm length at the various angular positions as the crank arm rotates through a complete revolution. |
