| 摘要 |
The described actuation device (100; 200) comprises a casing (102; 202), intended for the attachment to the handlebar (M) of the bicycle, a cable-winding bush (106; 206) (K), angularly mobile in the casing (102; 202) about a main axis (B) of the device (100; 200), a first driving mechanism (112; 212), acting on the bush (106; 206) to rotate it in a first angular direction (131; 231), a second driving mechanism (118; 218), acting on the bush (106; 206) to rotate it in a second angular direction (130; 230) opposite the first (131; 231), as well as indexing means (110, 107, 108, 109, 108', 123, 125, 127; 210, 270, 280, 280', 223, 275, 227) for removably holding the bush (106, 206) in predetermined angular positions. In accordance with the invention, the indexing means comprise first countering means (125; 275), to counter the rotation of the bush (106; 206) in the first direction (131; 231), and second countering means (127; 227), distinct from the first countering means (125; 275), to counter the rotation of the bush (106; 206) in the second direction (130; 230). Asymmetric operation is thus obtained which allows active actuation to be set both for upward gearshifting and for downward gearshifting. <IMAGE> |
