GB2027126A

GB2027126A - Vehicle anti-theft device

Info

Publication number: GB2027126A
Application number: GB7924668A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-08-03
Filing date: 1979-07-16
Publication date: 1980-02-13
Also published as: GB2027126B

Abstract

A plug (10) cooperates with a socket (11), the socket being for connection in the electrical circuits of a vehicle. The circuits can be broken and reconnected by removing and inserting the plug (10) which is provided with bridging conductive members (14) between some of its terminals (13). Preferably the plug comprises a piece of printed circuit board (15) which is arranged to be connected to an edge connector, the conductive tracks of the circuit board providing the bridging members. <IMAGE>

Description

SPECIFICATION Anti-theft device The present invention relates to an anti-theft device, and in particular to such a device suitable for use in automobile applications.

The present invention provides an anti-theft device for use in an automobile comprising first and second electrical connector devices, the first connector device having a plurality of terminals and conductive members connecting together a selected two of said terminals, the second connector device having a plurality of terminals corresponding in number to and arranged to receive the terminals of the first connector device, the two terminals of the second connector device which are arranged to receive said selected two terminals of the first connector device being arranged to be connected to a respective electrical circuit of the automobile, whereby connection of said first connector device to said second connector device completes said respective electrical circuit.

The first and second connector devices are conveniently provided by a plug and socket arrangement and in a preferred embodiment, the conductive members form part of a printed circuit board which is sealed within a housing. An edge connector is used as the socket which is mounted in a convenient location on the vehicle. The circuit board may then be unplugged from the socket and taken away by the driver when the vehicle is left unattended, thereby breaking one or more electrical circuits and immobilising the vehicle.

In order that the present invention may be more readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawing which shows a schematic representation of the embodiment.

The device is shown in the drawing as including a plug member 10 and a corresponding socket 11.

The socket 11 is provided with a number of terminals 12 and is arranged to be mounted in a convenient location on the vehicle. Wires forming part of various electrical circuits provided in the vehicle are connected to particular terminals 12.

The arrangement is such that each circuit is effectively broken by connection to two terminals 12 and a bridging link is required before the circuit may function. Wires are shown in the drawing as leading to the coil, the starter circuit and the ignition circuit of the vehicle, but these are only exemplary of other alternative and/or additional arrangements.

The plug member 10 includes a number of terminals 13 corresponding to and arranged to be received by the terminals 12. Conductive members 14, which may be conductive tracks on a printed circuit board 15, connect together selected pairs of terminals 13. The conductive members 14, e.g. that part of the printed circuit board 1 5 carrying the conductive tracks, are sealed within a housing 16 which protects the conductive members 14 and also conceals which 5 of the terminals 13 are connected together.

As may be seen from the simplified arrangement shown in the drawing, when the plug member 10 is inserted in the socket 11, the various circuits shown are completed via the terminals 12 and 13 and the conductive members 14. However. the plug member 10 must be the one specifically designed for use with the particular socket 11 and its particular configuration of connecting wires. When the plug member 10 is removed, the circuits are broken, and the vehicle immobilised. It will be appreciated than when as described above a circuit is completed this does not necessarily mean that current will flow. For instance, in the ignition circuit, the ignition switch will also need to be operated before current will flow to the respective circuit.By suitable mounting of the socket 1 1,the wires leading to the socket, their respective functions and the terminals 12 to which they are connected can be readily concealed.

Although the device as illustrated is provided with eight terminals on each connector in practice a larger number of terminals will be more e'ective in decreasing the possibility of 'guessing' the correct connections to be made. In this case, a number of terminals will be left unconnected. A further possibility is to provide suitably concealed bridging links within the socket 11, each such link being associated with two links in the plug member 10 and giving rise to a complex conductive path.

It will be appreciated that a non-reversible plug-socket arrengement should be used in order to prevent incorrect insertion and this can be achieved by keying the printed circuit board in a known manner. Using a connector arrangement provided with a large number, e.g. 16 or 32 of terminals it is possible to produce identical looking devices, each 'coded' with a differing combination of conductive members which is one of a very large number of permutations. The possibility of producing a 'master' plug member to fit any socket is thereby removed.

The presently preferred arrangement for the plug member is, as described above, to use a piece of printed circuit board carrying the conductive tracks thereon and adapted to be inserted in an edge connector. The housing may be provided by dipping the board in epoxy resin or by some suitable moulding procedure using a plastics composition, and this will improve the rigidity of the plug member 10 as well as insulating and concealing the conductive tracks. A plug member produced in this way can be sufficiently small to be readily carried in the driver's pocket when removed from the vehicle for security purposes, even with the provision of a large number of terminals.

An alternative arrangement is to use lengths of insulated wire as conductive members, the whole being surrounded by a moulded housing. This allows a more complex arrangement of bridging links in that it is possible for the links to mutually cross over. Another way of achieving crossing links would be to use double sided circuit board with plated-through connections. Whichever arrangement is utilised, it is preferred that the terminals be linearly disposed in a single row in order to produce a substantially flat plug member which is readily portable.

The device may be used with an electronic ignition system. In this case, the socket may be directly mounted to the housing of the ignition system, and interruptions in the electronic circuitry bridged by insertion of the correct plug member. A further refinement could be to use the device in conjunction with a conventional horn-activating burglar alarm system. Any unused terminals 12 in the socket 11 could be connected to the relay of this system, and an incorrect attempt to 'bridge' terminals in the socket would activate the alarm.

Claims

1. An anti-theft device for use in an automobile comprising first and second electrical connector devices, the first connector device having a plurality of terminals and conductive members connecting together a selected two of said terminals, the second connector device having a plurality of terminals corresponding in number to and arranged to receive the terminals of the first connector device, the two terminals of the second connector device which are arranged to receive said selected two terminals of the first connector device being arranged to be connected to a respective electrical circuit of the automobile, whereby connection of said first connector device to said second connector device completes said respective electrical circuit.

2. An anti-theft device according to claim 1 wherein said conductive members connect together at least another selected two of said terminals of the first connector device, corresponding terminals of the second connector device being arranged to be connected to one or more further electrical circuits of the automobile.

3. An anti-theft device according to claim 1 or 2 wherein said conductive members are provided by conductive tracks on a printed circuit board, said conductive tracks forming the terminals of the first connector device at an edge of the printed circuit board.

4. An anti-theft device according to claim 1 or 2 wherein said conductive members are provided by lengths of insulated wire connecting said selected two terminals together.

5. An anti-theft device according to any one of claims 1 to 4 wherein the terminals of each electrical connector device are disposed in a plane.

6. An anti-theft device according to any one of the preceding claims wherein at least one of the terminals of the first connector device and corresponding terminals of the second connector device are left unconnected.

7. An anti-theft device according to any one of the preceding claims wherein the conductive members are enclosed within a housing of the first connector device.

8. An anti-theft device according to claim 7 wherein the conductive members are sealed within said housing.

9. An anti-theft device substantially as hereinbefore described with reference to the accompanying drawing.