GB2233487A

GB2233487A - Vehicle protection system

Info

Publication number: GB2233487A
Application number: GB8914451A
Authority: GB
Inventors: Stefan Brian Joselowitz; Harold Eric Fox
Original assignee: SHURLOK DETECTOR Co
Current assignee: SHURLOK DETECTOR Co
Priority date: 1988-06-06
Filing date: 1989-06-23
Publication date: 1991-01-09
Also published as: GB8914451D0

Abstract

The system comprises a transmitter 10 on the person of a driver and a receiver 13 on the vehicle. The transmitter sends a coded signal which when received enables the vehicle to be driven. In the absence of such a signal, the vehicle is disabled as by closing a valve 15 in the fuel line. Thus when the vehicle is hijacked and the driver left behind, the vehicle comes to a stop when the signal from the driver is no longer received. The transmitter may be operative to transmit the coded signal only upon receipt of a coded signal from a transmitter on the vehicle, Fig. 2 (not shown). The transmitter carried by the driver may be a transponder, Fig. 3 (not shown). <IMAGE>

Description

VEHICLE PROTECTION This invention relates to the protection of vehicles against theft and particularly against hijacking.

The hijacking of trucks has of late shown an increase.

What usuaily happens is that the hijackers force the truck driver out of his cab, drive off with the truck and afterwards unload the contents of the truck on to their own transportation. In other worss the thieves are not so much interested in the truck but more in the load that it carries.

In these circumstances convenzionai immobil ising equipment is not suitabie to safeguard the truck and its payload.

A vehicle protection system according to the invention comprises an emitter- for emitting a key signal, a receiver on the vehicle for receiving the key signal, and an enabling circuit on the vehicle serving to enable the vehicle to be operated while the key signal is being received and to disable the vehicle in the absence of the receipt of the key signal and the nature and strength of the key signal being such that at a predetermined distance, or if the emitter is shielded from the vehicle, the key signal is no longer being received by the receiver so that the enabling circuit serves to disable the vehicle.

The signal is preferably a coded signal, and may be chosen from an electromagnetic signal, a radio frequency signal, an infrared signal and an ultrasonic signal.

Tne emitter may be an active or passive transponder and the vehicle then carries a transmitter which transmits a signal for activating the transponder to emit the key signal.

As a protection against hijacking the key transmitter would be worn by the driver of a truck. Thus as soon as the truck has proceeded for the predetermined distance from the scene of the hijacking, the truck would be immobilised. If, as is preferred, the disabling device is a valve in the fuel iine of the truck, the truck would not be able to move without the assistance of a diesel mechanic. Thus even if the hijackers retrieve the driver, it would b4e to no avail. In suitabie cases it could be arranged that the driver will not even be aware of the presence of the transmitter on his person.

Where vehicles operate in and around a fixed site, they would all be protected by a single key transmitter at a fixed point on the site. After hours the transmitter would be switched off to disable all the vehicles.

The invention will now be described in greater detail, by way of exampie, with reference to the drawings, in which: Figure 1 is a circuit diagram of a first embodiment of the invention in which a transmitter carried by the driver transmits to a receiver in the vehicle; Figure 2 is a circuit diagram of a second embodiment of the invention in which both the driver and the vehicle carry transmitters and receivers, and Figure 3 is a circuit diagram of a third embodiment of the invention in which the driver carries a transponder which is interrogate by a transmitter on the vehicle and transmits, in response thereto, a signal to a receiver on the vehicle.

In Figure 1 there is a transmitter 10 with an antenna 11 for transmitting the key signal. The transmitter 10, the antenna 11 and a battery for powering the transmitter 10 are all built into a piece of clothing such as a boot, a vest or a T-shirt. If the driver of a vehicle is not to know about the transmitter on his person, the clothing must be standard issue to all drivers.

Inside the vehicle there is an antenna i2 ana a receiver 13. Any output from the receiver 13 is amplified and fed to a solenoid 14 for controlling a valve 15 in the fuel ;ine of a vehicle. The arrangement is such that the valve i5 is open as long as the solenoid i4 is energised.

Wnen there is no current fiowing in the solenoid 14, a bias takes over and the valve 15 closes.

In use the transmitter 10 is continuously switched on and powered. It then transmits a coded signal which is received and analysed by the receiver 13. If the signal matches a preprogrammed signal in the memory of the receiver 13, the latter produces an actuating signal which is amplified and fed to the solenoid í4 which then keeps the valve 15 open.

In the event that the person wearing the transmitter 10 is separated from the vehicle and hence the receiver 13 beyond a predetermined distance the signal will be too weak to be received by the receiver 13 and the solenoid 14 will thus not be energised, so that the valve 15 will ,ciose, and the vehicle engine will come to a stop.

In the case of a diesel powered vehicle, it will only be possible to restart the engine after suitable bleeding of the fuel system For protecting the vehicles in and around the factory, the transmitter 10 will be in a fixed position and each vehicle will have a receiver 13 with the same code in its memory. In this case as soon as a vehicle is removed beyond the predetermined distance, it will stop so that it can be recovered with reasonable ease.

In Figure 2 there is also a transmitter 10 and a receiver 13. However, in this case the vehicle aiso carries a transmitter 16 which transmits a coded signal. Connected to the transmitter 10 is a receiver i7, which on receipt of the signal from the transmitter 16 powers the transmitter 10 to transmit its coded signal. This case thus involves the transmiss on of two coded signals and the decoding of those signals making it more difficult to succeed in code breaking.

In Figure 3 there is a receiver 13 as before and a transmitter 16. The transmitter 16 serves as an interrogator for a RF transponder 20. The transponder 20 has a chip which is preprogrammed with a unique unalterable identification code and is built into an article of clothing together with the necessary comrnunication coils. The transponder 20 transmits its code when it is within range of the transmitter 16 which emits a low frequency radio signal. The transmitted code is received by the receiver 13 as before to actuate an enabling circuit.

In the above examples the enabling circuit controls a fuel valve. In other embodiments the enabling circuit may control a switch in the ignition circuit of a petrol engine. It may also control a variety of other disabling devices and/or door locks on the vehicle.

In all cases a time delay could be provided in the circuits so that disabling only takes place after a predeter-mined interval. In the case of hijacking this will enable the vehicle and the driver to be separated by a safe distance before disabling ensues.

Claims

1. A vehicle protection system comprising an emitter for emitting a key signal, a receiver on the vehicle for receiving the key signal, and an enabling circuit on the v4ehicle serving to enable the vehicle to be operated while the key signal is being received and to disable the vehicle in the absence of the receipt of the key signal and the nature and strength of the key signal being such that at a predetermined distance, or if the emitter is shielded from the vehicle, the key signal is no longer being received by the receiver so that the enabling circuit serves to disable the vehicle.

2. Tne system claimed in claim 1 in which the signal is a coded signal.

3. The system claimed in either one of the above claims in which the signal is chosen from an electromagnetic signal, a radio frequency signal, an infrared signal and an ultrasonic signal.

4. The system claimed in any one of the above claims in which the emitter is a transponder and the vehicle then carries a transmitter which transmits a signal for activating the transponder to emit the key signal.

5. The system claimed in claim 4 in which the transponder is a passive transponder.

6. The system claimed in any one of the above claims in which the enabling circuit includes a solenoid controlled valve in the fuel line of an intsrnaì combustion engine for driving the vehicle.

7. The system claimed in any one o the above claims including a garment for the driver of a vehicle and in which the emitter is incorporated in the garment.

8. A vehicle protection system substantially as herein described with reference to any one of the accompanying drawings.