| 摘要 |
The mechanism 10 comprises a sun gear 3 rigidly attached to a main frame 1 and meshing with an adjacent planetary gear 4 of half diameter. A planetary crank arm 5 rigidly projects from the planetary gear 4 and is pivotally coupled to one end of a linkage arm 7, pivotally coupled at its other end to pedal crank 9 slidable in a crank assembly 8,15 rotatable with a shaft 6. In use, for one cycle of the mechanism, the crank 9 extends to a maximum and returns to the minimum rotating distance twice. The planetary crank arm 5 has a series of mounting holes for the linkage arm 7 to vary the extent of radial movement of the pedal crank 9, which also has a series of mounting holes for the pivot with the linkage arm to vary the radial extent of the crank 9 at its minimum position. |
