Immobilising vehicle steering.

摘要

A steering column shaft 22 has the normal ignition steering lock situated at the keyway 20. Between the steering lock and the steering wheel 11 weaker shear points 13, 14 are incorporated which will protect the steering lock if excess torque is put on the steering wheel and will render the steering mechanism immobile. Shear point 13 comprises two cross-drilled holes through the steering column shaft. Shear point 14 comprises threaded holes which accept shearable screws to attach the steering wheel boss 12 to the shaft spigot 16. If excess torque is applied in an attempt to break the steering lock, the screws at point 14 will fail. If a thief replaces these screws with high tensile screws, the column shaft will shear at holes 13 when excess torque is applied.