1. Field of the Invention
The present invention relates to a propulsion assembly having elongate members. It relates to a propulsion assembly having elongate members in particular as used in bicycles.
2. Description of the Related Art
The idea of using reciprocating elongate members for propelling a bicycle is known. For example, U.S. Pat. No. 5,335,927 to Islas shows a drive mechanism for a bicycle that employs elongate members in the form of foot levers mounted on the frame. The foot levers are mounted close to rear sprocket and are connected to a rotary drive mechanism which, in turn, is connected to the rear wheel.
While Islas provides foot levers, their purpose is defeated: Islas effectively splits the levers so that only a portion of each lever is used for the rider to generate torque. The portions of levers used are not much longer than that of the cranks on a conventional bicycle. As a result, Islas fails to enable the generation of noticeably more torque than that of the conventional bicycle. Also, Islas has a number of exposed parts and cables which may be prone to entanglement and failure.
Another example is U.S. Pat. No. 3,881,747 to Abbott which shows a bicycle foot pedal that is movable through an adjustable linkage of elongate members. The elongate members are in the form of levers for transmitting one-way rotational power to an elevated drive sprocket. The assembly is configured to enable a bicycle rider to vary the path of the pedal to simulate running, walking, or other desirable movement. However, Abbott also splits the levers and as a result the propulsion system provides a diminished leverage or torque. Abbott also requires for its propulsion system a bicycle that is completely re-modified.