| 摘要 |
In a chain-shifting device for a bicycle or the like a fixed support member is to be attached to the frame of the bicycle. A movable support member is mounted on said fixed support member by guide means so as to be movable with respect to said fixed support member by said guide means along a path of movement. A chain mover unit is mounted on said movable support member. First spring means are provided for biasing said movable support member towards one end of said path of movement. An adjusting switch is provided which is also to be attached to a part of the bicycle. This adjusting switch is capable of a plurality of switch positions. One terminal of said switch positions corresponds to said one end of said path of movement and is defined by switch stop means. Transmission means extend between said adjusting switch and said movable support member for positioning said movable support member along said path of movement against the action of said first spring means. The transmission means comprise an automatic compensating means for compensating for a change of the effective length of said transmission means so as to readjust in operation a predetermined position of said mover unit when said adjusting switch is in said terminal position even when a change of the effective length of the transmission means has occurred. The compensating means are such to continuously compensate for changes of the effective length of the transmission means. In view of this the compensating means comprise first and second compensating members which are a part of the transmission means and are interconnected by a clamp roller free-wheel unit. One of said compensating members engages an abutment member when a change of the effective length of the transmission means has occurred so that said compensating members are moved with respect to each other in a direction of movement permitted by said free-wheel unit so as to effect the compensation of the change of effective length of the transmission means. |
