GB2265415A

GB2265415A - Preventing unauthorised use of engines.

Info

Publication number: GB2265415A
Application number: GB9206240A
Authority: GB
Inventors: Stephen Alfred Williams
Original assignee: Rondish Co Ltd
Current assignee: Rondish Co Ltd
Priority date: 1992-03-23
Filing date: 1992-03-23
Publication date: 1993-09-29
Also published as: GB9206240D0

Abstract

The fuel supply, starter motor or ignition is disabled when a detector 30 receives a coded signal from a radio transmitter 32. The detector may also operate an alarm 20 and a central door locking system. <IMAGE>

Description

ENGINE DISABLING DEVICE This invention relates to an engine disabling device. It is particularly suited to disabling engines of vehicles such as passenger vehicles or cars and it is in this context that it is described. However, it should be realized that the device is not limited to such use.

Car alarms are now everyday items as people try to slow down the rapidly increasingly number of vehicles which are stolen each year. Insurance companies are also taking an active role in encouraging car owners to install vehicle alarms. Manufacturers are also taking steps by incorporating factory fitted car alarms in some models.

However, there is need to provide a device which can be used to disable a vehicle independently of the alarm system. Ideally, where the device is fitted to a vehicle with an alarm, it should cooperate with the alarm system such that arming of the device also causes the alarm to be activated. Thus, the device can be used as an adjunct to the alarm system and not seen as an additional alarm.

Accordingly, in one aspect thereof the present invention provides an engine disabling device comprising: control means operable by a remote switch, to arm and disarm the device and engine disabling means controlled by the control means.

Preferably, the remote switch is a radio frequency transmitter which emits a coded signal and the control means includes a radio frequency receiver and a detector to detect the coded signal to arm the device.

Preferably, the engine disabling means is an electrical switch arranged to be connected to the electrical system of the engine to interfere with the operation of the engine when the device is armed or is a fuel valve arranged to be installed in the fuel line to the engine and controlled to isolate the fuel supply when the device is armed.

Preferably, the device is arranged to be installed in a vehicle in conjunction with a vehicle alarm and the device includes an alarm interface such that arming of the disabling device activates the vehicle alarm Preferably, the vehicle has a radio controlled alarm system and the alarm interface includes a radio transmitter for sending a coded signal to the alarm to activate the alarm when the device is armed.

One problem with factory fitted alarm systems is that they are identical in each car so that if you know how the alarm is installed in Brand X car, you know how the alarm is installed in each Brand X car and thus, it is easier to overcome. Also, many factory fitted alarm systems simply require the car to be locked or unlocked using a key, to operate the alarm. Thus, copying the key or forcing the lock overcomes the alarm.

The device of the present invention adds an unknown factor into the standard alarm system. Its compact size means that it can be easily hidden from view and this makes its detection harder. Also, in the preferred embodiment in which the device is interfaced with the car alarm, there is no direct physical connection between the device and the alarm unit itself. Thus, even if the thief knows where the alarm is, he will not be able to trace the wires back to the disabling device directly. Moreover, as the device controls the alarm and not the alarm controlling the device, even if the alarm is overcome, the device remains armed disabling the vehicle.

Two preferred embodiments of the device according to the invention will now be described by way of example only, in which: Figure 1 is a black box electrical diagram showing a preferred embodiment of the disabling device according to the present invention fitted to a vehicle for disabling its engine, the vehicle being fitted with a basic alarm system; Figure 2 is a black box.electrical diagram showing a second preferred embodiment of the disabling device fitted to a vehicle having a radio controlled alarm system; Figure 3 is a diagrammatic representation indicating how one form of the disabling device may be installed in a vehicle, and Figure 4 is a diagrammatic representation indicating an alternative method of installing the disabling device of Figure 3.

The embodiment shown in Figure 1 is fitted to a vehicle generally represented by reference numeral 10. A basic car alarm system 20 is also fitted to the vehicle. This type of alarm system is operated by a central door locking mechanism 11 which locks all the doors simultaneously. The central door locking mechanism varies between makes and models but the essence of the operation is similar. When the door locking mechanism is operated to lock the doors, it activates the alarm system, normally with a slight time delay. When the door locking mechanism is operated to unlock the doors, the alarm is deactivated.

Some alarm systems require the door key to be turned a little further than usual and held for a short period, say 1 or 2 seconds, to "deadlock" the vehicle in which the doors cannot be unlocked from within and to activate the alarm. Sensors are used to prevent activation of the alarm when the ignition switch is turned on.

The preferred disabling device shown in Figures 1 and 2 has a main housing 30 containing control means in the form of an electronic controller. This housing is relatively small and thus can be mounted in or under the vehicle in a number of locations including within the engine compartment or boot, so that it is difficult to detect.

Connected to the housing by electrical wires is disabling means 31. In keeping with the design philosophy of making the disabling device as hard to detect as possible, the disabling means may take many forms and may include either singly or in combination, an electrical disabling means or a fuel disabling means. The use of multiple electrical disabling means adds to the effectiveness of the device, while the fuel disabling means is the most preferred.

Examples of electrical disabling means include ignition shorting/isolation, starter motor isolation (usually by isolating the starter motor solenoid) and fuel pump isolation (if an electrical fuel pump is used). Examples of fuel isolation include a solenoid valve fitted into the fuel supply line to the engine which, when the device is armed, turns off the fuel supply to the engine.

The device is controlled by a remote switch 32, preferably of the radio frequency type using a coded signal. The controller recognizes operation of the remote switch to arm and disarm the device. This is the device in its basic form. However, optional features as shown in Figures 1 and 2 include an indicator, a manual override switch, passive arming, an alarm interface and an anti-scanner.

An indicator in the form of a flashing LED 33 and/or a buzzer 34 may be connected to the controller to indicate that the device is armed. This is not recommended for most situations as it provides a visual indication to a would be thief that the device is fitted to the vehicle and also provides a starting point for tracing the location of the device.

A key switch 35 may be provided to prevent the disabling device arming. This is useful for overriding the device when the vehicle is being serviced and at other times when operation of the device is not desired. However, the location of the key switch should be safely guarded as it may be used to trace the location of the device.

A further option is the provision of passive arming of the device. This is where the device automatically arms a predetermined time period after the last door is closed.

The delay is typically 8 to 30 seconds. The device, as is usual for alarm systems, will not arm while the ignition key is turned on. The passive or automatic arming sequence begins when the ignition switch is turned off and a door is opened. The delay period countdown starts when the last door is closed. Re-entry into the vehicle during the delay period resets the countdown. The delay allows time from the door being closed for re-entering the car (or trunk) and the auto-arming sequence starts again from the last door closure. The closing of the last door may be detected by a connection to either a door switch, trunk switch or to a courtesy light of the vehicle (generally indicated by 36). The device may be disarmed by the remote switch and passive arming will not re-occur until the sequence is restarted by turning the ignition key on then off again.

For vehicles fitted with an alarm system, the device may be interfaced to the alarm for operating the alarm system.

This is achieved by providing an alarm interface connected to the controller.

Scanners are now available which "scan" known coded systems for radio controlled alarm systems. These scanners emit the range of known or most commonly used coded signals to deactivate a radio controlled alarm system. Although there are many different combinations of codes used, the scanner can cover the range of codes very quickly, and have been used very successfully by would-be thieves to de-activate alarm systems. To overcome this problem, anti-scanners have been developed which recognize the signals emitted by a scanner and maintain the system in the active state even though the scanner has sent the correct coded signal to the alarm. Such an anti-scanner 40 may be incorporated within or connected to the controller to prevent operation of the device by a scanner.

In Figure 1, the vehicle 10 is shown fitted with a basic alarm system which is operated by a central door locking mechanism. Normally when the driver's door is locked, all doors of the vehicle are also locked and when the driver's door is unlocked, all doors are unlocked. A central switch inside the vehicle may also lock and unlock all doors. The alarm system is connected to the central door locking mechanism 11 to activate the alarm when the doors are locked and deactivate the alarm when the doors are unlocked. This type of system is easily overcome by a would be thief by forcing the door lock of the vehicle.

The alarm interface of the device of Figure 1 includes a connection 37 to the central door locking mechanism of the vehicle such that when the device is armed, the door locking mechanism operates to lock the doors which in turn, activates the alarm system and when the device is disarmed, the doors are unlocked deactivating the alarm In this way, there is no direct connection between the alarm system and the disabling device and overcoming the alarm will not overcome the device while allowing the device to control the alarm system so that a single remote switch will arm the device, lock the doors and activate the alarm system.

For the more complicated door lock activated alarm system, the interface provides the necessary signals to lock the doors and to activate the alarm via the door lock connection.

In the passive arming procedure, the controller may be arranged such that on passive arming the doors are not locked and the alarm is not activated. In this arrangement, called partial passive arming, the vehicle will still be disabled by the device but not protected by the alarm which may be an advantage if the vehicle is left standing while infrequently attended such as when loading or unloading goods.

In complete passive arming, the doors would be locked and the alarm activated when the device arms, say 10 seconds after the last door is closed.

An anti-scanner 40 is diagrammatically shown connected to the housing 30 for interrogating the signal received from the remote key. Normally, in practice, the anti-scanner would be part of the electronics of the controller and not a separate item located outside of the housing.

In Figure 2, the vehicle is fitted with a radio controlled alarm system 25. In this arrangement, the alarm interface includes a radio transmitter arranged to send a coded signal to the alarm system to operate the alarm. In this arrangement, there is no physical connection between the alarm and the disabling device but still operation of the device effects operation of the alarm system. So again the alarm is controlled by the device and a single remote switch can operate the device and the alarm. Overcoming the alarm system again does not affect operation of the disabling device leaving the vehicle or engine inoperable.

Accordingly, when the device is armed, it sends a coded signal to the alarm system to activate the alarm and when the device is disarmed, it sends a coded signal to the alarm system to deactivate the alarm.

In the embodiment shown in Figures 3 and 4, the disabling device uses a fuel solenoid valve 38 as the disabling device to isolate the fuel supply to the engine. Figure 3 diagrammatically shows the device fitted to the underside of the vehicle 10 and both the housing 30 and the fuel valve 38 are protected by a steel box 39 fitted to the underneath of the vehicle and covering the fuel supply line. The box 39 protects the device from tampering and from physical damage.

In Figure 4 the housing is diagrammatically shown fitted within the body of the vehicle with the fuel valve located in the fuel line between the fuel tank and the engine. The fuel valve, being small, can be readily concealed or located in difficult to find locations making it difficult for a would be thief to detect it. Also, the housing 30 may be located in any position making its detection difficult.

The controller is arranged to arm the device when the power is applied to the device as occurs, for example, when the device is first installed or when the vehicle's battery is changed or disconnected and reconnected. This means that should the battery become fully discharged or isolated which may result in a malfunction of the vehicle alarm system, the disabling device will arm when power is restored rendering the vehicle inoperable.

Thus, it should be realized that the disabling device is not an alarm system in its own right but although it can be used by itself as an anti-theft device, it can be fitted as an enhancement to an existing alarm system to prevent a vehicle being stolen.

Claims

1. An engine disabling device comprising: control means operable by a remote switch, to arm and disarm the device; and engine disabling means controlled by the control means

2. A device as defined in claim 1, wherein the remote switch is a radio frequency transmitter which emits a coded signal and the control means includes a radio frequency receiver and a detector to detect the coded signal to arm the device.

3. A device, as defined in claim 2, wherein anti-scanner means is associated with the control means to prevent operation of the device by a radio frequency scanner.

4. A device as defined in claim 1, 2 or 3, wherein the engine disabling means is an electrical switch arranged to be connected to the electrical system of the engine to interfere with the operation of the engine when the device is armed.

5. A device as defined in claim 1, 2 or 3, wherein the engine disabling means is a fuel valve arranged to be installed in the fuel line to the engine and controlled to isolate the fuel supply when the device is armed.

6. A device as defined in any one of the preceding claims, wherein the device is arranged to be installed in a vehicle in conjunction with a vehicle alarm and the device includes an alarm interface such that arming of the disabling device activates the vehicle alarm.

7. A device as defined in claim 6, wherein the vehicle alarm is of the type activated by locking the doors by a central locking system and the alarm interface is arranged to trigger the central locking system to lock the doors and to activate the alarm when the device is armed.

8. A device as defined in claim 7, wherein the alarm interface triggers the central door locking system to unlock the doors and deactivate the alarm when the device is disarmed.

9. A device as defined in claim 6, wherein the vehicle alarm is a radio controlled alarm and the alarm interface includes a radio transmitter for sending a coded signal to the alarm to activate the alarm when the device is armed and to deactivate the alarm when the device is disarmed.

10. A device as defined in any one of the preceding claims, wherein the device includes indicating means to indicate that the device is armed.

11. A device as defined in any one of the preceding claims, wherein the device includes an override switch to prevent arming of the device.

12. A device as defined in any one of the preceding claims, wherein the control means includes a passive arming circuit which senses the closing of the vehicle doors and/or trunk and arms the device a predetermined time period after the doors/trunk are closed.

13. A device as defined in any one of the preceding claims, wherein the control means is arranged to arm the device when power is applied to the device.

14. An engine disabling device substantially as hereinbefore described with reference to the accompanying drawings.