| 摘要 |
An application for a device for human conveyance includes a front wheel and a rear wheel. The rear wheel interfaced to a sprocket through a ratchet drive system which allows forward rotation of the rear wheel in response to forward rotation of the sprocket and allows free backward rotation of the sprocket. A frame interfaces the front wheel to the rear wheel keeping the front wheel at a constant distance from the rear wheel. The front and rear wheels are rotatably interfaced to the frame. A front end of an arc-shaped spring is affixed to the frame in proximity to the front wheel and a rear end of the arc-shaped spring has a sprocket gear interfaced to the sprocket whereas depression of the arc-shaped spring pushes the rear-end of the arc-shaped spring in a rearward direction with respect to the rear wheel and the sprocket gear turns the sprocket in a forward rotational direction. |
