| 摘要 |
PURPOSE: A forward driving change gear of a bicycle is provided to enhance convenience when driving a bicycle by automatically changing the internal gear engagement without operation of a lever and to improve efficiency by transmitting driving power in forward driving through backward rotation of a pedal at a rotational ratio the same as that of forward rotation of the pedal. CONSTITUTION: A forward driving change gear of a bicycle comprises: a pedal shaft(5) rotating with a pedal bar(4); internal and external disks(10,20) spaced apart from each other on the pedal shaft; a housing(30) covering the outer faces of the internal and external disks; a drive sprocket(40) placed near the outer face of the housing; a forward drive wheel integrated with the drive sprocket; a backward drive wheel(60) placed near the inner face of the housing; a two-way ratchet wheel(70) selectively engaged with the drive wheels; a direction change relay gear(80) for induction of forward rotational force to the drive sprocket; and a penetration bolt(92) inserted into a boss(2) of a frame(1) by penetrating through the center of a fixed plate(86) and the housing to be connected by a thread. When the pedal shaft rotates backwardly, an internal gear(81) engaged with an inner face gear(52) of the backward drive wheel rotates backwardly. An interlock gear(83) engaged with the internal gear rotates forwardly. Thus, the forward drive wheel and the drive sprocket interlocking with the interlock gear rotate forwardly. Therefore, a bicycle moves forwardly even if the pedal shaft is rotated backwardly.
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