| 摘要 |
There is provided an occupant-propelled land vehicle, such as a bicycle, having a frame, at least one front wheel, at least one rear wheel, and a seat for the rider of the vehicle, supported by the frame, wherein two levers, each having a front end and a back end, are pivoted on the frame on each side forwardly of the rear wheel and at a point substantially closer to the back end than to the front end. Two rigidly interconnected and spaced-apart parallel discs, one of the discs being toothed, are associated with an upper portion of the rear wheel. Connecting rods are pivotally connected to the back ends of the levers and are eccentrically-rotatably connected to the discs, a sprocket wheel is connected to the axle of rear wheel, and a driving chain is included in a connection between the toothed disc and the rear-wheel sprocket wheel. Downward pressure on the front end of a lever will cause the connecting rod at the back end of the lever to move upwardly to cause the associated disc and the rigidly-joined disc to rotate, which rotation is transmitted by the chain to the rear-wheel sprocket wheel and thereby to the rear wheel of the vehicle to cause movement of the vehicle over the land.
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