Perfected antitheft device for vehicle, in particular to control the steering column lock of the vehicle

The anti-theft system comprises a motor mounted to turn a rotor, and a locking bolt (20) for the vehicle steering column. A cam (22) couples the angular rotation of the rotor (14) to the translational movement of the bolt. A main cam follower (24) presses against the profiled surface of the cam. The profile of the cam includes a notch (36) to index the position of the rotor (14). The anti-theft system comprises a stator and a rotor (14) mounted to turn within the stator between two extreme angular positions. A locking bolt (20) for the vehicle steering column is displaceable between free and locked positions for the column, whilst a cam mechanism (22) couples the angular rotation of the rotor (14) to the translational movement of the bolt. A main cam follower (24) is elastically urged against the profiled surface of the cam. The profile of the cam includes at least one notch (36) which is intended to co-operate with the main cam follower (24) to index the position of the rotor (14) within its angular course, without modifying the state of the steering column.