摘要 |
A rider propelled vehicle includes a frame having a hub portion. Each of two cranks has a crank shaft extending into the hub portion and mounted on the hub portion for rotation relative thereto independent of the other crank shaft. Both of the cranks can be rotated through a top dead center position and a bottom dead center position in which the force applied by the rider to the crank for propulsion of the vehicle is at a minimum. An output shaft extending from within the hub portion is operatively connected to a drive wheel of the vehicle for driving rotation of the drive wheel to propel the vehicle. The output shaft is mounted on the hub portion for rotation relative to the frame and the cranks. A torque transmission assembly interconnecting the output shaft with the crank shafts for transmitting torque from the crank shafts to the output shaft is contained within the frame. The torque transmission assembly is constructed such that the cranks are accelerated and decelerated relative to each other whereby the cranks never simultaneously occupy their top and bottom dead center positions.
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