GB2290109A

GB2290109A - Vehicle immoblising system

Info

Publication number: GB2290109A
Application number: GB9411697A
Authority: GB
Inventors: Stephen Shanley
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-06-10
Filing date: 1994-06-10
Publication date: 1995-12-13
Also published as: GB9411697D0

Abstract

An F.M. radio transmitter 10 or microwave transmitter sends, when authorised, a coded signal to a receiver 16 of a selected vehicle 14. The receiver causes the battery connection to the ignition coil 26 to be interrupted and the alarm 24 operated. <IMAGE>

Description

TITLE: A Vehicle Immobilising System DESCRIPTION This invention relates to a vehicle immobilising system.

It is known to provide a tracking system to aid the recovery of stolen vehicles. The tracking system comprises a transmitter which is hidden within or on the vehicle and a receiver which is able to detect a signal from the transmitter if within range. The system is presently operated with co-operation from the police and if a vehicle which is fitted with a transmitter is stolen then the transmitter may be remotely activated and the position of the vehicle can be determined if a receiver comes within range of the transmitter.

However, although the system can accurately determine the position of a vehicle it is still necessary to recover the stolen vehicle. If the position of the vehicle is reported to the police then there is a possibility of the vehicle being moved before the police have an opportunity to recover the vehicle.

There is a problem with so called "joyriderstl who steal high performance vehicles and race them through towns or cities. These "joyriders" have caused serious accidents and the police have, in the past, resorted to chasing the stolen vehicles although this in itself has led to accidents since the chases have often been at high speed.

An aim of the present invention is to provide a vehicle immobilising system which overcomes the above mentioned problems.

In accordance with the present invention there is provided a vehicle immobilising system comprising means for selectively transmitting a signal to one of a plurality of receivers, means associated with each receiver to immobilise a vehicle, wherein receipt of said signal by a receiver activates said means for immobilising.

It is preferred that each receiver is adapted to receive a predetermined coded signal and that said selection means is preferably provided by the selection of a coded signal to be transmitted which corresponds to the coded signal adapted to be received by the selected receiver. Preferably said coded signal is unique.

The system may further comprise alarm means associated with each receiver whereupon receiving said coded signal, said alarm means is activated. The alarm means may be the vehicle's hazard lights and/or horn.

The immobilising means may upon activation disconnect power to an ignition coil. Said means may comprise switching means located preferably in a power line between the vehicle's battery and ignition coil.

The switch means may upon activation connect a positive terminal of the ignition coil to ground.

The transmitter may be a radio or microwave transmitter and is preferably an F.M. radio transmitter.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawing, which is a block diagram of an embodiment of the present invention.

A remotely situated F.M. radio transmitter is indicated by numeral 10 and has a control means 12 for selecting one of a plurality of possible signals to be transmitted. For ease of description a single vehicle is indicated in dotted outline 14 and it will be appreciated that the system will be connected to a number of vehicles. The vehicle 14 has a receiver 16 fixed to the chassis thereof. The receiver can be positioned anywhere within or on the vehicle but obviously an attempt is made to locate the receiver in an inaccessible position. The receiver is adapted to respond to a predetermined coded signal and is connected via control line 18 to switch means 20. The switch means 20 has two import terminals a and b, two output terminals c and d and a control terminal e to which control line 18 is connected.

The vehicle further comprises a 12 volt battery 22, alarm means 24 and an ignition coil- 26. The positive terminal of the battery 22 is connected via line 28 to the positive terminal of the ignition coil 26. However, the line 28 is interrupted by switch means 20 and input terminal a is connected to the output of the battery and output terminal C is connected to the positive terminal of the ignition coil. The second input terminal b is connected to ground via a suitable source e.g., the chassis, and the second output terminal d is connected to alarm means 24 via line 30.

In normal use, terminal a is directly connected to terminal c such that the ignition coil is powered and there is no connection to either terminal b or d.

An example of the use of the vehicle immobilising system will now be given. Each owner of a vehicle fitted with a receiver is given a prearranged identification code e.g., a series of letters or numbers or a combination of both. In the event of their vehicle being stolen, the owner contacts a control centre which will take details of the vehicle e.g., licence plate number, and the identification code which are verified with their own records in order to establish that the owner is in fact the true owner and hence entitled to instruct their vehicle to be immobilised.

As described above, the receiver in the vehicle will only respond to a predetermined coded signal and hence the appropriate signal is selected by the control means 12 and transmitted by transmitter 10. Receiver 16 receivers the signal and sends a control signal via line 18 to terminal e of the switch means 20. The control signal activities the switch such that the electrical contact between terminal a and c is broken, terminals b and c are electrically connected and input terminal a is connected to output terminal d. In consequence, the power to the ignition coil is cut and the positive terminal grounded. The result of this will be that the engine is immobilised. Hence, if the vehicle is moving at the time the signal is transmitted then it will lose power and be brought to a standstill. Since the steering and brakes of the vehicle are not affected by the immobilising action the vehicle can be safely brought to a standstill. The activation of the switching means electrically connects the alarm means to the battery and hence the alarm means, which may include the vehicle's hazard lights and horn, are powered hence are activated.

A single example of providing the means for immobilising the vehicle has been described above and other methods of immobilising a vehicle are envisaged.

It is envisaged that the police will have the authority to request the immobilising of a vehicle. As an example, if the police are following a suspect vehicle it will be possible for them to, contact the control centre and request the immobilising of the vehicle by simply identifying the vehicle e.g. by licence plate number.

Claims

1. A vehicle immobilising system comprising means for selectively transmitting a signal to one of a plurality of receivers, means associated with each receiver to immobilise a vehicle, wherein receipt of said signal by a receiver activates said means for immobilising.

2. A system as claimed in claim 1 wherein each receiver is adapted to receive a predetermined coded signal.

3. A system as claimed in claim 1 or 2 wherein said selection means is provided by the selection of a coded signal to be transmitted which corresponds to the coded signal adapted to be received by the selected receiver.

4. A system as claimed in claim 1, 2 or 3 further comprising alarm means associated with each receiver and which is activated upon receiving said coded signal.

5. A system as claimed in claim 4 wherein said alarm means is the vehicles hazard lights and/or horn.

6. A system as claimed in any one of claims 1 to 5 wherein upon activation the immobilising means disconnects power to an ignition coil of the vehicle.

7. A system as claimed in claim 6 wherein the immobilising means comprises a switch located in a power line between the vehicles battery and ignition coil.

8. A system as claimed in claim 7 wherein the operation of the switch connects a positive terminal of the ignition coil to ground.

9. A system as claimed in any one of the preceding claims wherein the transmitting means is a radio transmitter.

10. A system as claimed in claim 9 wherein said radio transmitter is an F.M. radio transmitter.

11. A system as claimed in any one of claims 1 to 8 wherein the transmitting means is a microwave transmitter.

12. A vehicle immobilising system substantially as hereinbefore described with reference to and as illustrating by the accompanying drawing.