| 摘要 |
An automatic speed- varying system includes: a first speed- varying device (1) formed on a driving rotating device such as a bike pedal (11) and its driving chain sprocket (15) having a first planetary gear system (12) and a ratchet wheel (16) for preliminarily manually variating a speed of the driving rotating device, and a second speed- varying device (3) formed on a follower rotating device such as a follower chain sprocket (21) formed on a bike rear wheel (4) driven by the driving rotating device having at least a second planetary gear system (34,35) operatively engageable with the follower chain sprocket (21) by at least a centrifugal coupling (32) for automatically varying a speed of the follower rotating device. <IMAGE> <IMAGE> |
