GB1456547A - Remotely controlled lock assemblies and apparatus incorporating such assemblies - Google Patents

Abstract

1456547 Lock A A HILLS 7 Dec 1973 56836/73 Heading E2A A key-operated lock is provided with means for remotely preventing withdrawal of the key or operation of the lock. In a first embodiment shown in Fig. 1, a barrel lock 20 employs a key 21 which, in the usual way, may only be inserted and withdrawn in the 'locked' position of the lock. The inner end of the key has a notch 23 provided in its back edge, and a pivoted detent 25, operated by electromagnets 26, 27 may engage the notch to retain the key in the lock when desired. The detent 25 is indexed in the holding and releasing positions by a spring 28 engaging notches in its outer end. The fitted edge of the key engages a notched lever 32 which is displaced by rotation of the key to operate contacts 54, 55, Fig. 10, and a pin 35 on the barrel, Fig. 11, acts on another lever 33 to operate further contacts 67, 68. A shoulder 41 on the detent 25 prevents rotation of the key in the retained condition. Initial insertion of the key tilts lever 32 to close contacts 54, 56, but rotation of the key closes the other contacts 55, 57 and then through lever 33, contacts 67, 69. The lock may be used to prevent unauthorised use of hired equipment e.g. a vehicle, and when this is not hired out, it is plugged in at 98, 99, 100, 101, see Fig. 13, to a lease depot which, when switch 103 is closed, passes current through contacts 54, 56 (closed because the key is inserted) to the key-retaining electromagnet 26 to prevent the key being removed by the client. At the same time, a relay 109 is energised to disable an alarm 111 at the depot by current also through contacts 54, 56 showing that the key is in place. When operation of switch 103 at the station energises releasing electromagnet 27, the key may be turned to close ignition circuit contacts 55, 57, and starting contacts 67, 69. In a modified circuit (Fig. 14, not shown) the station circuit is released by an identity-cord reader instead of by an attendant. In the alternative form of lock shown in Fig. 15, rotation of the lock barrel and, hence, withdrawal of the key is prevented by a plunger 145 entering a hole 143 in the barrel. The plunger is controlled by electromagnets 146, 147 and indexed by a spring-loaded plunger. A rotary switch acts in the same way as the switches described above.