GB2243814A - Clutch immobilisation vehicle anti theft system - Google Patents

Abstract

A vehicle immobilisation system, interacting with the mechanical operation of the vehicle's clutch to prevent unauthorised driving of the vehicle, consists of a high security cylinder mechanism remotely connected to a mechanical latching mechanism fitted integrally to the vehicle engine or chassis and forming a mechanical break within the conventional action of a vehicle clutch operating cable. Activation of the security cylinder mechanism 28 via a high security key relaxes the tension in remote cable 16 causing cam mechanism in latching device 27 to retreat allowing a catchment device to adopt standby status. Depression of the clutch pedal causes a sliding latch, attached via a cable to the clutch operating lever to become entrapped within the latching device 27 thereby trapping the clutch assembly in its separated state preventing transmission between engine and gearbox. Reversal of the security key reverts the system to normal operation allowing free use of the clutch. <IMAGE>

Description

This invention relates to a Clutch Immobilisation Vehicle Anti Theft System.

There are various forms of vehicle immobilisation systems, which basically fall into two distinct categories; electrical and mechanical.

Electrical systems generally isolate one or more parts of the vehicles wiring system, typically the ignition circuit in order to prevent unauthorised starting of the vehicle.

Mechanical immobilisers rely on rather cumbersome devices to be secured around various mechanical components, thereby preventing their correct functioning and preventing the vehicle from being driven away.

Typical examples of such immobilisers would be devices which clamp together the steering wheel and brake or clutch pedals, clamp together the gear change lever to the handbrake and devices which clamp the driven wheels of the vehicle.

By their very design, it is necessary that such mechanical devices be physically attached and detached during and after use and that when not in use, must be stored in a location remote to their 'in use' location.

Because of the physical attachment/detachment necessary for mechanical immobilisers and the storage problems and time taken to apply such devices, it is often the case that shortly after purchase, these devices are used to a lesser and lesser degree, until finally not at all.

Also the inexpensive nature of the devices constitutes the use of low to medium levels of security mechanisms, which can easily be overcome by competent car thieves.

Also the majority of electrical devices are reasonably easy for the competent car thief to overcome, and again rely upon the owner to religiously arm them each that the vehicle is left unattended.

According to the present invention there is provided an anti-theft device, integral within the vehicle's mechanics, by which the vehicle's clutch activating mechanism can be interrupted and locked in such a state that the engine's torque cannot be mechanically transmitted via the clutch plate assembly to the gearbox and that such a device can be activated from a remote location for the purpose of preventing the vehicle from being driven under its own power, and that such activation be integrated within the normal start up procedure of the vehicle.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Fig A. shows a schematic layout of the anti theft system and their fitment within the vehicle's mechanics.

Fig B. shows a sectional diagramatic layout of the anti theft system.

Fig C. shows a sectional layout of the security actuating cylinder mechanism.

Fig 1.1 illustrates the system in its idle state.

Fig 1.2 illustrates the system on standby.

Fig 1.3 illustrates the system in its locked state.

Fig 1.4 illustrates the system if tampered with.

Fig 1.5 illustrates the system in its unlocked state.

Fig 1.6 illustrates the breakdown of components within the latching unit.

Referring to the drawings the anti theft device comprises a security cylinder mechanism 28 attached to a sheathed control cable 33 by way of a special 'snap in' coupling 32, linking to the latching device 27 and attached to it via a special 'snap in' coupling 34.

The latching unit 27 is affixed- to the vehicle engine or chassis and held secure via a special backnut 12. A clutch cable 1 is secured within the mechanism of the latching device 27 which controls the operation of the clutch lever via a cable 13.

The system operates via a continuous on/off cycle which is ensured due to the fact that the security key which operates cylinder 35 is flexibly attached to the vehicles ignition key (not shown) and can only be removed from the cylinder 35 in the 'armed' state-therefore exit from the vehicle necessitates the security key to be removed.

Refering to fig 1.1, this assumes that the system has just been fitted to the vehicle in readiness for operation.

The security key is inserted within the cylinder 35 which due to its spring bias has ensured that the actuating cam 34 has revolved, thereby tensioning the control cable 16.

The slider mechanism 5, consisting of a device having serrations, grooves, teeth or other means of catchment is rigidly attached at one end to the end of a clutch cable, and is free to travel within the latching housing 27.

Attached to the other end of the slider 5 is a cable 13 which transmits the actions of the slider 5 to the clutch lever, which ultimately operates the vehicles clutch plate assembly.

Depression of the clutch pedal operates the clutch cable in the conventional manner, transmitting its action via the slider 5.

Referring to fig 1.2 the removal of the security key from the cylinder 35 rotates cam 34 which allows pin 30 and piston 31 to be pulled via cable 16 due to the action of spring 18 into a relaxed state.

The action of spring 18 causes a cam mechanism 14,19,20 to release a latching device 9 into a standby state.

Referring to fig 1.3, depression of the clutch pedal will cause slider 5 to move into catchment with device 9. Cable 13 being rigidly attached to slider 5 has operated the clutch lever, thereby seperating the friction plates of the clutch assembly and due to the catchment cannot now return.

Also due to the catchment of slider 5, the compensating spring 6, normally under compression, is now released therby removing any slack from clutch cable 1, allowing the clutch pedal to return to its normal position.

Subsequent depression of the clutch pedal will merely cause compression of the compensating spring, offering no activation to the clutch assembly itself, thereby rendering the vehicle immobile under its own power.

Referring to fig 1.4, the only forseeable means for the device to be tampered with would be to sever the remote control cable 33 and 16.

In doing so spring 18 would force the cam 19 to a position within latching unit 27 whereby an anti tamper mechanism 22 would come into operation thereby preventing any manual manipulation of control cable 16 resulting in irretrievable locking of the catchment mechanism and slider, thereby maintaining the clutch plates in their seperated state.

Assuming that no such tampering has taken place the device can be unlocked via use of the security key - refering to fig 1.5, insertion of the security key allows cylinder barrel 35 to rotate under spring bias towards the unlocked position. This action causes cam 34 to pull against pin 30 causing piston 31 to draw cable 16 which being linked to cam 19 will transmit movement via release mechanism 14 thereby releasing catchment device 9 which will allow slider 5 to regain normal operation. A pull action caused by the clutch pressure plate will cause slider 5 to move along housing 27 to its free state whereby the vehicles clutch can be operated in the normal manner. This action will also cause compensating spring 6 to resume its compressed state.

The cycle is now completed, with the security key trapped within the cylinder 35 - removal of this key will initiate the cycle once again.

Another embodiment of this device comprises of an indentical layout differing only in that the means of activation may be substituted by an electronic means, in that the security mechanism 28 be replaced by an electronic security switch, electronic keypad, infra red or remote control device which would operate the catchment mechanism via an electric motor or solenoid.

Claims (14)

1. A vehicle anti theft system whereby the means of immobilisation constitutes entrapment of the vehicle's clutch plate assembly in its seperated state - ie no drive transmission.

2. A vehicle anti theft system as-claimed in claim 1 whereby the immobilising device is fitted integrally within the vehicle's existing mechanics.

3. A vehicle anti theft system as claimed in claims 1 and claim 2 whereby the activating security mechanism is placed remotely from the immobilising device.

4. A vehicle anti theft system as claimed in claim 3 whereby the security mechanism is linked to the immobilising device via a remote actuating linkage.

5. A vehicle anti theft system as claimed in claims 3 and 4 whereby the remote control linkage is protected against malpractice via an anti tamper mechanism.

6. A vehicle anti theft system as claimed in claims 1,2,3,4 and 5 wherein fittment of an anti tamper mechanism will allow irretrievable locking of the immobilisation device.

7. A vehicle anti theft system as claimed in claims 1,2,3, 4,5 and 6 whereby the device is fitted with an integral clutch cable assembly specifically designed for the particular vehicle on which it is intended to be used.

8. A vehicle anti theft system as claimed in claims 1,2,3, 4,5,6 and 7 whereby the device will accept standard clutch cable end fittings via a special adaptor.

9. A vehicle anti theft system as claimed in any preceding claim whereby fittment of the system to any clutch cable operated vehicle may be carried out by the utilisation of a range of special adaptors and fittings.

10. A vehicle anti theft system as claimed in any previous claims wherein immobilisation of the clutch prevents the friction and driven plates of the clutch assembly from physical contact with each other.

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11. A vehicle anti theft system as claimed in any previous claim wherein the immobilisation device interferes with the normal operation of the clutch activating cable by means of a lockable mechanism.

12. A vehicle anti theft system as claimed in any previous claim wherein the immobilisation device is fitted with a spring compensating mechanism to overcome clutch cable slackness and prevent unwanted operation of automatic clutch regulating mechanisms.

13. A vehicle anti theft system as claimed in any previous claim wherein the security operating device may take the form of an electronic keyswitch, keypad, infra red transmitter/receiver or radio controlled device and wherein the catchment activating mechanism may take the form of a solenoid, electric bolt, electric latch or motor driven mechanism.

14. A vehicle anti theft system as substantially described herein with reference to the accompanying drawings.