GB1403867A - Locking devices - Google Patents

Abstract

1403867 Locks WILMOT-BREEDEN LTD 20 Dec 1972 [23 Dec 1971] 60179/71 Heading E2A [Also in Division B7] A key operated anti theft device comprises a spring loaded bolt and a separately spring- loaded bolt-carrier, in each case spring loaded towards the locking position and key-operable means comprising a cam which acts on and moves the bolt carrier to withdraw the bolt, the bolt carrier being movable independently towards the locking position of movement of the bolt is impeded so that it does not engage fully to the locking position with the mechanical part to be locked. A body 1 having a split portion for engaging a vehicle steering column houses the slidable bolt 5 urged by a spring 12 to operative position and slidable in a slot in the bolt carrier 9 urged by springs 13 (Fig 5 not shown) to the operative position. Since the carrier 9 can move to the operative position independently of the bolt 3 if, when the bolt is projected, it is not aligned with the locking recess in the steering column it engages the recess when the steering column is turned. The body houses a cylinder lock 6 which is connected by a shaft 8 to a rotatable switch mechanism 7. The shaft 8 extends through the bolt carrier 9 and supports a cam 16 which engages the bolt carrier to withdraw the bolt when the key is turned from the Lock to Ignition position. The tip of the key abuts a projection 17a on a lever 17 which normally pivots on the cylinder lock 6 and the cam 16, the lever having cam shafts which engage in bores in the cam 16 and in a member 22 by which the lock is coupled to the shaft 8. The lever also has a projection 17b and is urged by a torsion spring to abut a spring urged plunger 25 or the bolt carrier, the lever being retained in abutting position by the tip of the key engaging the projection 17e so preventing the bolt from moving to locking position. To lock the steering column the key is moved to the lock position and then withdrawn thus freeing the lever 17 to pivot under the force of the bolt carrier which under spring-pressure slides past the projection 17b and moves the bolt to locking position. To withdraw the bolt the key is moved to Ignition position and the cam engages the bolt carrier and retracts the plunger 25 to allow the bolt carrier to move past the lever projection 17b thus releasing the bolt from the steering column recess. The plunger 25 contacts a contact 31 which may be connected to an indicating circuit. The engagement of the plunger with the projection 17b prevents lock picking as does the lever by preventing direct access to the bolt carrier by a wire inserted in the key way.