| 摘要 |
A wheelchair and drive mechanism powered by reciprocating operation of a drive lever. The drive mechanism provides a continuously variable gear ratio allowing wheelchair operation at varying speeds and on differing inclines; and is readily fitted to a standard wheelchair by a drive-associated bayonet mount. A drive mechanism ratchet wheel includes an upper and lower radial crank secured for rotation thereabout by an axle. Each crank includes a pawl assembly that engages with circumferential ratchet wheel teeth to transfer drive energy supplied to the radial cranks from connecting arms to the ratchet wheel. The connecting arms are coupled to a reciprocating lever arm and operate in concert with the pawls to alternately engage with and transfer energy to the ratchet wheel, or disengage therefrom. While one connecting arm and associated pawl is transferring energy to the ratchet wheel, the other connecting arm is disengaging an associated pawl from the ratchet wheel. Energy is transferred during both a forward and rearward stroke of the lever arm to effect efficient wheelchair and drive operation.
|
