A coupling system for a torque transmission device of a motor vehicle includes a sliding sleeve. An actuator including a mobile member movable between a rest position and an activated position is linked to the sliding sleeve by a rotating kinematic link and by an elastic return member fixed in rotation about the axis of revolution. The mobile member is capable, by means of the kinematic link, of driving the sliding sleeve from the retracted position to the coupling position and of loading the elastic return member by passing from the rest position to the activated position. The elastic return member is able, while unloading, by means of the kinematic link, to return the mobile member from the activated position to the rest position and the sliding sleeve from the coupling position to the retracted position.