GB1061382A - Improvements in and relating to vehicle security systems - Google Patents

Abstract

1,061,382. Intruder alarm systems. ALARMATIC DEVICES Ltd. Aug. 23, 1963 [Aug. 24, 1962; Jan. 28, 1963], Nos. 32558/62 and 3443/63. Heading G4N. [Also in Division F11 A vehicle security system includes a first relay R1 which when operated prepares the energization circuit for a second relay, R2 controlling the alarm device 38. In operation, " scrambling " the code selector switch 2 connects the negative supply to one side of relay R1, the positive supply being connected to the other side by switch 10 when the driver's door is opened. Relay contact 12 and a second switch 40 on the driver's door close energizing thermal delay 42 so that unless the door is reclosed within a predetermined time relay R2 will operate to sound alarm horn 38. Once energized, relay R1 holds in over contact 20, and opening of other vehicle closures closes one of switches 22, 24, 26 and causes relay R2 to operate instantaneously. Such operation may however be delayed in the case of switch 26 by operating a delay button 44. Once sounded, the alarm is cancelled by selecting the correct code on switch 2. This releases the relays and completes a circuit via contact 18 to an indicator 48 which remains energized until the switch 2 is " rescrambled." Once relay R1 has operated, the vehicle is immobilized by contact 16 which opens to close a fuel valve or break the ignition circuit, Fig. 2 (not shown), of the vehicle. An emergency button 50 is provided for operation of the alarm manually. In a modification, Fig. 3 (not shown), the thermal delay 42 is replaced by a manual " holdout " button (60) which must be held operated while the driver's door is open to prevent operation of the alarm. A key switch 66 may be operated when the vehicle is to be left unattended for long periods to cut out the thermal delay.