| 摘要 |
A speed control system for a bicycle for controlling a change speed device through a change speed wire, having a shift lever (8) movable in opposite directions from a home position; a takeup reel (5) connected to one end of the wire for winding up the wire (520) with movement in one direction of the shift lever; a one-way transmission mechanism (100) for transmitting only movement in one direction of the shift lever to the takeup reel (5); position retaining teeth and a position retaining pawl for retaining the takeup reel (5) in a plurality of winding positions; and a retention canceling cam mechanism (400) for canceling retention of the takeup reel by the position retaining teeth (16) and pawl (17), and allowing the takeup reel to rotate in the wire unwinding direction. The retention canceling cam mechanism (400) includes a release element movable between a release position and a non-release position, and a spring for urging the release element to the non-release position. The release element is movable to the release position by movement of the shift lever from the home position in the other direction. The shift lever (8) is connected to the takeup reel (5) through a one-way mechanism (100) which transmits only movement in the wire winding direction. Consequently, the takeup reel (5) is successively shifted in the winding direction by reciprocating the shift lever on one side of the home position. When the shift lever is shifted to the other side of the home position, the takeup reel (5) is freed from position retention by action of the release element. As a result of the release, the takeup reel urged in the wire unwinding direction rotates in the unwinding direction, thereby effecting a return through change speed stages. <IMAGE> |
