Patent GB-1336233-A (GB)
Title: Key operated lock
IPC: B60R25/021
Filed: 1971-04-19
Abstract: 1336233 Anti-theft locks JOSEF VOSS KG 19 April 1971 [10 June 1970] 21207/71 Heading E2A  A key-operated lock for preventing the movement of a control member of a vehicle has a locking bolt 9 movable between a withdrawn position and a thrown position towards which it is spring biased, a cylinder 4 of the lock being rotatable between a plurality of positions one of which is a locking position, the arrangement being such that when the cylinder is rotated by an operating key to the locking position and whilst the key is still inserted in the cylinder, movement of the bolt into its thrown position is prevented by a safety catch which serves to release the bolt to allow the bolt to move to its thrown position only upon complete or almost complete withdrawal of the key from the cylinder, the safety catch consisting of a rigid lever 18 pivotally mounted intermediate its ends for pivoting between a bolt retaining position and a bolt releasing position, insertion of the key, when the cylinder of the lock is in the locking position, causing the lever to pivot from its bolt releasing position to its bolt retaining position, the bolt being provided with a pawl 24 which is spring biased to an end position which it occupies when the bolt is in its thrown position and also when the bolt is in its withdrawn position, the insertion of the key when the lock cylinder is in the locking position thereof and the bolt is thrown, causing the lever to pivot from its bolt-releasing position to its bolt-retaining position, whereafter rotation of the cylinder causes the locking bolt to be withdrawn, the pawl being engaged by a bolt-engaging end portion of the lever during withdrawal of the bolt in such a manner that the pawl is caused to yield from its said end position until the bolt is withdrawn to such an extent that the pawl is able to return to its end position, at which time the throwing of the bolt will be prevented since the bolt retaining end portion of the lever which lies in its bolt retaining position is in the path of the pawl. As shown, the cylinder 4 is connected to a cam 6 which is in engagement with the bolt so that rotation of the cylinder and hence of the cam from the locking position withdraws the bolt against the bias of the spring 8. The bolt has a tail 10 formed with an aperture 12 through which a shaft 13 secured to the cam 6 extends, the shaft being connected to an ignition and starting switch 15. The pawl 24 which is pivoted to the bolt is L-shaped and is disposed in a recess of the arm 10' of the tail; the spring 8 which moves the bolt to the thrown position also engages an arm 27 of the pawl and moves it into a position in which, when the bolt is in the withdrawn position, it is in engagement with one end of the lever 18; the other end of the lever projects into a keyway 20, being biased to such a position by a spring 19. When the lock is in the locking condition and a key is inserted into the keyway the back of the key engages the end of the lever in the keyway and pivots the lever so that its other end is disposed in the path of the pawl; rotation of the cylinder by the key then withdraws the bolt by means of the cam 6 and the end of the lever 18 acts on an inclined surface 29 of the pawl to pivot the pawl out of its path, the pawl snapping back into position when the bolt is fully withdrawn so that its face 31 engages the end portion of the lever whereby the lever prevents movement of the bolt to the thrown position; when the cylinder 4 is turned back into the locking position the lever 18 retains the bolt in the withdrawn position until the key 3 has been almost completely withdrawn when the lever 18 can pivot under the bias of its spring 19 to release the pawl, the spring 8 then moving the bolt to the thrown position. In a modification the cylinder is provided with a keyhole guard and the lever instead of projecting into the keyway is engaged by a portion of the guard so that when the key is inserted into the lock the portion of the guard is moved by the side of the key which pivots the lever to the position in which, when the bolt is withdrawn, it comes into engagement with the pawl. In a further construction the bolt moves parallel with the axis of the cylinder instead of at right angles to the axis the cam being modified but otherwise the arrangement is similar to that of the first embodiment with an end portion of the lever 18 being disposed in the keyway 20 to be moved by the back of the key, the pawl is however biased by a separate spring instead of by the bolt biassing spring.