A sequential gear control device for a motor-vehicle gearbox comprising a pair of rotary drums

摘要

The drum (10) is intended to be mounted so as to be rotatable about a rotation axis (X1) and has, on its lateral surface, at least one guide channel (22, 26) in which at least one follower member (24, 28) is intended to be guided slidably to convert the rotary movement of the drum (10) about its own rotation axis (X1) into translatory movement of at least one engagement sleeve of the gearbox. A series of positioning notches (50) are provided on the lateral surface of the drum (10) and are spaced apart at regular angular intervals along a circumference of the drum (50) for snap-engagement by a stop member (54, 56) associated with the drum (10).