| 摘要 |
PURPOSE:To prevent lateral dislocation of a chain to improve durability by constituting the device so as to rotate a crank gear normally and reversely through moving a crank lever back and forth, and transmit the movement to a wheel driving shaft provided with two free gears in parallel through two sets of chain in parallel. CONSTITUTION:A crank gear 4 with which a crank lever 3 is provided is journaled so as to position on one line with a free gear 1, and intermediate gears 5, 6 are rotationally movably journaled in parallel between the free gear 1, 2 and the crank gear 4. The free gear 1 and the crank gear 4 are connected with each other through a bicycle chain 7, and the chain 7 is wrapped over them so as to contact with the intermediate gear 5 at its outer circumference in slackening condition. Further, the free gear 2 and the intermediate gear 6 are connected through a bicycle chain 8. Hereby, by operating the crank lever 3 back and forth, the free gears 1, 2 are respectively rotated through the chain 7 and 8 to rotate a wheel. |
