GB2292130A

GB2292130A - Motor vehicle security device

Info

Publication number: GB2292130A
Application number: GB9516011A
Authority: GB
Inventors: Basil Daniel Egawhary
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-08-09
Filing date: 1995-08-04
Publication date: 1996-02-14
Also published as: GB9516011D0

Abstract

An annular member (8) is provided to link the steering wheel and steering column (6) of a motor vehicle, the member having a plurality of retractable teeth (9, 10) on its radially inner and/or outer surfaces to engage respective slots or grooves in the steering column or wheel. The teeth are retracted or pushed out by a mechanism in response to an electronic security code being input at a key pad. The ignition, immobilisation or other circuits may also be linked to the keypad. <IMAGE>

Description

MOTOR VEHICLE SECURITY DEVICE This invention relates to a motor vehicle security device. In particular, it relates to a device, preferably an electronic device, for engaging or disengaging the steering wheel and steering column of a motor vehicle such that the vehicle is rendered inoperable when the steering wheel and steering column are disengaged from one another.

There are many sorts of vehicle security devices of different types. These range from purely mechanical devices to complex electronic immobilisers or costly alarm systems. One type of essentially mechanical security system is one which causes the steering wheel of the vehicle to be disengaged from the steering column and thereby renders the vehicle undriveable until the steering wheel is re-engaged. Examples of these are shown in GB 164541, GB 400456 and GB 405362. Prior art systems of this type tend to have a purely mechanical construction of a toothed member or series of members which, when positioned correctly, interlock with the steering wheel or steering column assembly and thus enable engagement.

Precautions have to be taken that the relevant parts are not easily removable and replaceable by unauthorised persons. Also, these systems often rely on the members being displaced axially to engage or disengage. This takes up space and can complicate the mechanism with an accompanying risk of malfunction.

An object of the present invention is to provide a simple and improved device for engaging or disengaging the steering wheel and steering column of the vehicle.

According to the present invention there is provided a device for engaging or disengaging the steering wheel and steering column of a motor vehicle, comprising a means for linking the steering wheel and steering column, which means comprises a linking means having a plurality of retractable teeth on at least one surface which are adapted to engage with at least one of the steering wheel and steering column when unretracted and to disengage when retracted, and means for causing the teeth to engage and/or disengage.

The linking means may comprise retractable teeth on the steering wheel or steering column or, more preferably, on an intermediate annular body, having teeth on at least one of its radially inner or outer surfaces for engaging the steering wheel and/or steering column.

Preferably, teeth are provided both on the internal and external surfaces so as to engage and disengage from both the steering wheel and the steering column.

The teeth are preferably irregularly shaped and/or spaced.

According to the present invention in a second aspect there is provided a method of engaging or disengaging the steering wheel and steering column of a motor vehicle, comprising causing a plurality of retractable teeth to engage with at least one of the steering wheel and steering column, to cause operative engagement between them, and causing the teeth to retract to disengage.

The security device operating the system may be linked to the vehicle's ignition, immobilisation, alarm and/or other electric circuits.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which; Figure la and lb illustrate schematically a steering wheel of a vehicle showing an electronic combination lock; Figure 2 illustrates schematically the steering column of a vehicle and a device according to the invention; Figures 3 and 4 show a device according to the invention in respective engaged and disengaged modes; and Figure 5 shows schematically a control mechanism.

Referring to the figures, Figure 1 shows a steering wheel for a motor vehicle. The steering wheel comprises a rim 1 spaced apart from a hub 2 by a plurality of spokes 3. Mounted on the hub 2 is an eletronic key pad 4 unit for entering a security code for operating the security device, which code would be known only by an authorised user. This unit may also be used to actuate the vehicle's ignition or other electrical or electronic systems as well as other car alarm systems and/or immobilisers. Alternatively, a key may be applied to a locking mechanism or any other type of security access mechanism may be used. When the steering wheel is one upon which it is desired to mount an airbag, then the key pad may be offset to allow the airbag to be centrally mounted. Alternatively the airbag may be differently shaped to the conventional shape.For instance, the airbag may be annular, e.g. toroidal and thus mounted around the key pad 4. The underneath of the steering wheel, as shown in Figure 1 (b) has a cylindrical protrusion bearing a plurality of grooves 5 which are preferably irregularly shaped and/or spaced. These are also shown in dotted lines on Figure 1 (a).

Figure 2 shows schematically a steering column and a piece for connecting the steering column to the steering wheel. The steering column 6 is provided with a plurality of angularly spaced longitudinal ribs 6 which are preferably irregularly shaped and/or spaced. An intermediate member 8 for linking the steering column with the steering wheel comprises an annular member 8 having a plurality of retractable teeth 9,10 on its respective radially inner and outer faces. The teeth are retractable radially. When engaged, i.e. protruding from the respective faces of the ring 8, these teeth 9 and 10 engage with teeth 7 and 5 respectively on the steering column and steering wheel, to cooperate with them and thus provide a linkage such that rotation of the steering wheel causes rotation of the steering column so that the vehicle can be steered.When either or both sets of teeth on member 8 are disengaged, i.e. retracted into the body, then the steering wheel is effectively disengaged from the steering column and thus free wheels. A simple mechanism is therefore provided which, when combined with a security lock, provides an effective security system for a vehicle.

Figures 3 and 4 illustrate the teeth of member 8 when respectively retracted and protruded.

The electronic key pad 4 is part of a mechanism which ensures that the teeth 9 and 10 are only retracted when desired. Such a mechanism is shown schematically in Figure 5. A control unit 11 receives an entered code (e.g. a four digit code) from key pad 4 and is programmed to actuate a motor 12 or other actuator (e.g. solenoid or miniature electro-hydraulic actuators) only if the correct code is entered. Alternatively the input device may be a voice recognition, finger-print recognition or other device or be a remote controlled key for example. Other input devices may be used. Such control techniques are well known. The control unit may also be programmed to set an alarm condition if more than a predetermined number of attempts are made to enter the correct code, indicating that an unauthorised person is attempting to guess the code. The alarm condition may operate to preclude further code entries for a time period, e.g. one hour, or may enable an engine immobiliser or disable the steering or electrical systems of the car until, for example, a key or other secondary security device is activated by the authorised user. The security codes may be factory set but changeable by the authorised user.

Control unit 11 may also be connected to the ignition, immobiliser, or other electrical circuits of the car so that entry of the correct code must be made before these electrical circuits can operate.

The motor drives a mechanism which acts to retract and/or protrude the teeth 9 and/or 10 of disc 8.

This may be done for example by a circumferential toothed belt mounted within the body of disc 8 and driven by a shaft connected to the motor. The toothed belt acts upon pinions connected to the teeth to drive them in or out.

Other mechanisms such as internal ramps against which the teeth abut and which are rotated about the central axis of member 8, or solenoid-operated mechanisms may be used.

Many other mechanisms will be apparent.

For safety, it will be preferred that the failsafe position of the mechanism is with the teeth engaged so that the vehicle can be steered. Thus, it may be preferred to have the teeth biassed, e.g. by springs, into the engaged position so that when the user wishes to disengage the steering he enters a code to enable the motor or other means to draw the teeth into the retracted position where a latch e.g. an electromagnetic latch secures it. When the user returns to the vehicle, a further entry of the code causes the latch to disengage and the biassing force to return the teeth to the engaged position. Upon an electrics failure for example, the electromagnetic latch would not function and therefore the system reverts to its fail-safe position. Means such as a back-up battery may be employed to stop the system's electricity supply being disengaged in an attempt to steal the vehicle.

The control means may alternatively be arranged to automatically disengage the steering, e.g. after a door is closed and/or no motion or voice inside the car is detected, or the control system may be responsive to a remote control unit, a voice recognition system, fingerprint or other unique identified recognition system, in addition or as an alternative to the key pad.

Instead of electrical or electronic operation a key mechanism may be used to retract or push out the teeth. This may be of a chuck type arrangement, or a screw mechanism or by a cylinder/barrel type or lock mechanism in which insertion of a correct key causes the teeth to be pushed into their engaged position.

The retractable teeth may instead be mounted directly on the steering wheel or column, for moving radially with respect to the longitudinal axis to engage grooves or slots in the other respective one of the column or wheel assembly. This avoids the need for a further annular member between the wheel and column. However, the provision of a separate linking or engagement member or body enables the security system to be retro-fitted to an existing steering assembly

Claims

CLAIMS 1. A device for engaging or disengaging the steering wheel and steering column of a motor vehicle, comprising a means for linking the steering wheel and steering column, which means comprises a linking means having a plurality of retractable teeth on at least one surface which are adapted for engaging with at least one of the steering wheel and steering column when unretracted and disengaging when retracted, and means for causing the teeth to engage and/or disengage.
2. A device as claimed in Claim 1, wherein the means for causing the teeth to engage or disengage is electronic.
3. A device as claimed in Claim 2, wherein the linking means comprises an annular body having a plurality of retractable teeth on at least one of its radially outer or inner surfaces for engaging with at least one of the steering wheel and steering column.
4. A device as claimed in Claim 3, wherein teeth are provided on both the radially inner and outer surfaces of the annular member, to engage both the steering wheel and steering column.
5. A device as claimed in Claim 1 or Claim 2, wherein the retractable teeth are provided directly on the steering wheel or the steering column, for engaging with the respective other one of the steering wheel and steering column.
6. A device as claimed in any one of the preceding claims, wherein the teeth are irregularly shaped and/or spaced.
7. A device as claimed in any one of the preceding claims, wherein the means for causing the teeth to engage and/or disengage comprises a security input device.
8. A device as claimed in Claim 7, wherein the input device is a numerical code input device, and further comprising control means operable to engage and/or disengage the teeth when a predetermined code is input.
9. A device as claimed in Claim 7, wherein the security input device is a voice recognition device, a finger-print recognition device or other unique personal identifier device.
10. A device as claimed in any one of the preceding claims, wherein the teeth are biassed into a fail-safe position.
11. A device as claimed in any one of the preceding claims which is connected to an ignition, immobilisation, alamr and/or other electric circuit of the vehicle.
12. A method of engaging or disengaging the steering wheel and steering column of a motor vehicle, comprising causing a plurality of retractable teeth to engage with at least one of the steering wheel and steering column, to cause operative engagement between them; and causing the teeth to retract to disengage.
13. A method as claimed in Claim 9, which is electronically activated.
14. A method as claimed in Claim 9 or Claim 10, wherein the teeth are provided on at least one of the radially inner and outer surfaces of an annular body for engaging with at least one of the steering column and steering wheel.
15. A method as claimed in any one of Claims 12 to 14, wherein a security means is provided so that the teeth are moved only when an authorised security code, identifier, or device is applied.
16. Security apparatus substantiallz as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.