A system for interlocking the movements of two shafts of forks of a gearbox, the system comprising:
- a) a first lever which:
- is mounted so as to be able to pivot, about a first axis, in two opposite directions to take up at least one active angular position in relation to a neutral intermediate angular position,
- bears a first eccentric axial finger connected to a first driveshaft of a first fork, and
- bears a first eccentric cam, a cam profile of which has a first notch for locking the first lever in its neutral position;
- b) a second lever which:
- is mounted so as to be able to pivot, about a second axis parallel to the first axis, in two opposite directions to take up at least one active angular position in relation to a neutral intermediate angular position,
- bears a second eccentric axial finger connected to a second driveshaft of a second fork, and
- bears a second eccentric cam, a cam profile of which has a second notch for locking the second lever in its neutral position;
- and
- c) an interlocking rocker which:
- is mounted so as to be able to pivot, about a rocking axis parallel to the first axis, in two opposite directions to take up one or the other of two opposite locking angular positions, in relation to an intermediate angular position of rest toward which the interlocking rocker is elastically returned, and
- bears an eccentric axial locking pin which, when the interlocking rocker is in its angular position of rest and when each drive lever is in its neutral angular position, is positioned facing the first locking notch and the second locking notch at the same time,
- wherein in the system, angularly on either side of its locking notch, each cam profile of a lever has an active portion which is able to interact with the locking pin to cause the interlocking rocker to pivot and the locking pin to engage in the locking notch of the cam of the other lever, and then to hold the locking pin in a locking engaged position to angularly lock said other lever in its neutral position.