Anti-theft locking means for a vehicle steering shaft
An anti-theft locking device for vehicles includes an annular locking sleeve mounted concentrically about and normally in frictional engagement with the vehicle steering shaft. The locking sleeve includes a body portion having a serpentine cross-sectional configuration, thereby defining on the inner periphery of the sleeve a plurality of alternate smooth convex projections and concave valleys. The convex projections are in frictional engagement with the circumferential surface of the steering shaft by a predetermined frictional force that is greater than the rotational torque force produced during normal steering operation of the vehicle. A plurality of circumferentially spaced teeth extend radially outwardly from the locking sleeve, thereby to define between the teeth a plurality of locking slots one of which is arranged to receive the free extremity of the locking arm of a locking device.
1. Anti-theft locking means for locking the steering column relative to the chassis of an automotive vehicle, said steering column being subjected to a given first rotational torque during normal steering operation of the vehicle, comprising:
(a) a steering shaft having a smooth cylindrical circumferential surface;
(b) an annular locking sleeve mounted concentrically about said steering shaft circumferential surface, said locking sleeve including:
(1) an annular body portion having a serpentine cross-sectional configuration of generally uniform thickness, thereby to define on each of the inner and outer peripheries of said body portion a plurality of alternate smooth convex projections and concave valleys, respectively, the inner convex projections on the inner periphery of said sleeve being in frictional engagement with the circumferential surface of said steering shaft with a predetermined frictional force that is greater than the corresponding force produced by said first rotational steering torque; and
(2) a plurality of circumferentially spaced teeth extending radially outwardly from the outer periphery of said locking sleeve from alternate ones of the outer convex projections on said outer periphery of said sleeve, said teeth defining therebetween a plurality of radial locking slots; and
(c) locking means operable to lock said locking sleeve to the vehicle chassis, said locking means including:
(1) a locking body adapted for engagement with the vehicle chassis; and
(2) an arm portion extending from said locking body into locking engagement with one of said slots, thereby to lock said sleeve against rotation relative to the vehicle chassis.
2. Anti-theft locking means as defined in claim 1 , wherein each of said teeth has a cross-sectional configuration such that the adjacent side walls of successive teeth are generally parallel.
3. Anti-theft looking means as defined in claim 2 , wherein each side wall of each of said teeth is connected with the adjacent portion of the outer periphery of the sleeve body portion by a curved merging surface.
4. Anti-theft locking means as defined in claim 1 , wherein each of said slots extends the length of said locking sleeve.
5. Anti-theft locking means as defined in claim 1 , wherein each of said slots extends from one end of said sleeve toward, and terminates short of, the other end of said sleeve, thereby to define a continuous annular flange adjacent said sleeve other end.
6. Anti-theft locking means as defined in claim 1 , wherein said predetermined frictional force produced by said inner convex projections has such a value that it is overcome upon the application of a second rotational torque to said steering shaft that is greater than said first rotational torque.