GB2289359A

GB2289359A - Safety device for a motor vehicle

Info

Publication number: GB2289359A
Application number: GB9509629A
Authority: GB
Inventors: Dennis Roger Nield
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-05-12
Filing date: 1995-05-12
Publication date: 1995-11-15
Also published as: GB9409444D0; GB9509629D0

Abstract

A safety device for a motor vehicle, comprises a crash detector which is connected, electrically or otherwise, to a warning signal for example provided by the vehicle's hazard warning lights, and which is adapted to activate the warning signal in the event that the motor vehicle is involved in an accident. The crash detector can comprise a breakable rod (10) which is mounted in a bumper or bumper liner of the vehicle and one or more breaking members (8) which are substantially rigidly mounted in the bumper, and wherein the breakable rod passes through or abuts against or is in close proximity to the braking members whereby, in the event of the bumper being distorted in an accident, the breakable member is broken by engagement with one or more of the breaking members (8) so as to actuate a detection device (18). <IMAGE>

Description

DESCRIPTION SAFETY DEVICE FOR A MOTOR VEHICLE The present invention relates to motor vehicle safety. In particular, it relates to a safety device for a motor vehicle which provides a warning signal to indicate when a motor vehicle accident has occurred.

Multiple accidents are all too common on congested modern roads. In a typical scenario, a driver does not see crashed vehicles in the road ahead of him before it is too late to avoid them.

Alternatively, the driver may see the crashed vehicles but not realise that they are stationary . This is a major cause of multiple accidents on motorways, in which drivers do not realise until too late that the car ahead of them has in fact already been in a collision and come to a halt.

Many accidents of this type could be prevented if drivers approaching the scene of a crash were provided with a warning to draw their attention to the crashed vehicles and to warn them that they should take action to avoid such crashed vehicles.

It is an object of the present invention to provide such a warning.

Of course, motor vehicles are ordinarily provided with hazard lights, actuable by the driver, for precisely this purpose. These do provide an effective signal, visible from all road directions, but, in real life, hazard lights are often not switched on when they are needed, immediately after an accident. This may be because the driver is rendered unconscious by the accident; because an air bag inflated on impact briefly restrains the driver's movements; because the driver does not have time to react before a second collision occurs; or simply because the driver forgets to turn the hazard lights on.

To overcome this problem, the present invention provides a warning signal which is automatically activated in the event of a crash.

In accordance with the present invention there is provided a safety device for a motor vehicle, comprising a crash detector which is connected, electrically or otherwise, to a warning signal and which is adapted to activate the warning signal in the event that the motor vehicle is involved in an accident.

An automatic signal, which can be activated immediately in response to an impact, overcomes the above shortcomings of manually activated signals.

In a particularly preferred embodiment , the warning signal is formed by the motor vehicle's hazard warning lights and/or the vehicle's brake lights.

In another possible embodiment, the warning signal could be connected and adapted to operate the rear (foot) brakes.

In-a still further embodiment, the warning signal could be or include, an electromagnetic signal which is arranged to be transmitted automatically upon the occurrence of a detected accident for enabling the accident to be recognised immediately at a remote location adapted to receive such signal.

In a further preferred embodiment, the crash detector further comprises a breakable member which, in use, is mounted in, on or at a bumper of the motor vehicle so as to be broken upon deformation of said bumper. Preferably, the breakable member is elongate and is mounted within said bumper, laterally to the normal direction of travel of the vehicle.

The breakable member may advantageously comprise a narrowed neck portion. In this way, breakage of said member is confined to the neck portion.

In another preferred embodiment, the safety device further comprises mechanically biassed switching means which are normally retained in an "off" position by mechanical connection to the breakable member, wherein breakage of the breakable member causes the switching means to be released into an "on" position.

Alternatively, in accordance with the present invention, the breakable member may contain or comprise a conductor arranged to be severed in the event of a crash, and the crash detector may further comprise means for activation of the warning signal upon severance of the conductor.

In order to ensure breaking of the breakable member upon deformation of the bumper, it is within the scope of the present invention to provide at least one breaking member mounted within the bumper and arranged to transmit deformation of the bumper to the breakable member.

Preferably, the breakable member and the breaking member(s) are mounted within a bumper liner. This facilitates installation of the safety device.

In another alternative preferred embodiment, the crash detector is in the form of an inertial impact detector.

In a still further embodiment, the crash detector can include one or more strain gauges positioned at strategic locations on the vehicle body/chassis and adapted to provide electrical signals for activating said warning signal in the event that the associated part of the body/chassis is distorted by a predetermined extent in an accident.

Specific embodiments of the present invention will now be described, by way of example only, partly with reference to the accompanying Fig. 1 which shows a first embodiment of a crash detector which forms part of the present invention.

The crash detector shown in Fig. 1 is designed to be accommodated within a bumper of a motor vehicle.

Preferably one crash detector is provided in the front bumper and one is provided in the rear bumper.

The crash detector comprises a bumper liner 2, whose external surface is shaped to substantially conform to the internal shape of a motor vehicle bumper. The bumper liner 2 thus comprises a laterally extending elongate portion 4 and, for vehicles in which the bumper extends around to the sides of the vehicle, longitudinally extending side portion 6. In the embodiment shown in Fig. 1, six breaking plates 8 are mounted in an elongate cavity 7 within the elongate portion 4, being spaced along said cavity.

These breaking plates 4 each abut against an elongate breakable member 10 which extends along the entire length of the elongate cavity 7 and is mounted at both its ends in recesses or holes in the bumper liner 2, as shown at 12 in Fig. 1. The mounting may be cushioned by means of foam, or alternatively the breaking rod may be in direct contact with the bumper liner.

At its centre, the breakable member 10 comprises a neck 14 wherein its cross sectional area is reduced.

The material used for the breakable member 10 must have a degree of brittleness, so that when subject to stress the breakable member breaks at the neck 14 instead of deforming. Glass is used in the present embodiment, and the breakable member is formed as a solid glass member although it may, alternatively, be formed as a glass tube.

A connection member 16, which in the present embodiment is in the form of a rubber band, passes around the neck 14, and in addition, is fixed to an actuating lever of a switch 18, being held under tension thereby. The switch is spring biassed away from the breakable member 10 and towards an "on" position, but is held in an "off" position by a force exerted by the connection member 16 in the direction towards the breaking member.

The switch 18 is mounted in the engine compartment (for a crash detector in the front bumper) or in the car boot (rear bumper). Since the switch may be placed in the main body of the car, well away from sections of the car which are likely to receive impacts during a crash, it is unlikely to be damaged during a crash.

The switch is electrically connected to a warning signal, which in the present embodiment is formed by the motor vehicle's hazard lights.

The operation of the crash detector is as follows. Any significant impact to the front or rear of the car causes distortion to the front or rear bumper, changing the position of the breaking plates 8 relative to the breakable member 10 and/or the distance between the two mountings in which the breakable member is held, and so causes the breakable member 10 to break at the neck 14. The connection member 16 is thereby released, so that the actuating lever of the switch 18 is free to move under the influence of its spring biassing into its "on" position. The motor vehicle's hazard warning lights are thereby activated, indicating that an accident has occurred.

In an alternative embodiment of the invention, the breakable member 10 does not merely abut against the breaking plates 8 but passes through holes in them, so that displacement of the breaking plates in either direction causes the breakable member 10 to break.

The number, positioning and form of the breaking plates may be varied without departing from the scope of the present invention. For example it is appropriate in some applications to place them on the side of the breakable member 10 which faces towards the switch 18.

It is possible to dispense with the liner 2 and to mount the breakable member 10 and the breaking plates 8 directly in the bumper.

The connection member 16 may take a variety of forms. For example, it may comprise a metal rod or wire attached by means of hooked ends to the actuating lever of the switch 18 and to the breakable member 10.

In another embodiment of the present invention, the crash detector is as illustrated in Fig. 1, except that it does not comprise a connection member 16 or a switch 18. Instead a conductor is provided within the breakable member 10 passing through the neck 14. The conductor may for example, be formed as a metal wire of small cross section contained within a breakable member 10 which is formed as a solid glass rod. The conductor is electrically connected to a detector circuit. When the breakable member breaks, the conductor itself is broken, and the detector circuit detects the break in the conductor and actuates the warning signal.

In this embodiment, it may be appropriate to provide more than one neck 14 through which the conductor passes.

In still another embodiment of the present invention, (not illustrated) the breakable member additionally comprises two longitudinally extending side portions contained within the side portions 6 of the bumper liner/bumper. These may be integrally formed with the laterally extending portion of the breakable member 10, so that the member forms an "n" shape. Additional breaking plates may also be provided in the side portions 6 of the bumper liner/bumper.

In this way, it can be ensured that even when the motor vehicle is subject only to side impacts which cause no deformation of the front portion of the vehicle bumper, the warning signal is actuated.

A motor vehicle safety device in accordance with the present invention need not include a crash detector which is mounted in the bumper. The crash detector may instead be formed as an inertial impact detector of known type. Such detectors are already being fitted to cars.

It is also within the scope of the present invention to provide a crash detector comprising one or more strain gauges of known type for detection of deformation of the motor vehicle body, chassis or bumpers.

The present invention may be adapted to provide, in addition to a visible warning signal, an electromagnetic signal (most preferably a radio signal) which can be remotely detected. In this way, the motor vehicle safety device may alert rescue services or others to the occurrence of an accident.

In another preferred embodiment of the present invention, the crash detector is used to actuate not only a warning signal, but also the brakes of the motor vehicle. In this way, it is ensured that the vehicle is brought rapidly to a halt after an accident.

As will be apparent from the preceding description, the motor vehicle safety device in accordance with the invention provides a simple and effective means of preventing road accidents.

Claims

1. A safety device for a motor vehicle, comprising a crash detector which is connected, electrically or otherwise, to a warning signal and which is adapted to activate the warning signal in the event that the motor vehicle is involved in an accident.

2. A safety device as claimed in claim 1, wherein the warning signal is formed by the motor vehicle's hazard warning lights.

3. A safety device as claimed in claim 1, wherein the warning signal is formed by the motor vehicle's rear brake lights.

4. A safety device as claimed in claim 1, wherein the warning signal is formed by the motor vehicle's hazard warning lights and rear brake lights.

5. A safety device as claimed in any of claims 1 to 4, wherein the warning signal includes an electromagnetic signal which can be detected remotely by a suitable receiver to identify the occurrence of an accident detected by said crash detector.

6. A safety device as claimed in any preceding claim, which is adapted to actuate the brakes of the motor vehicle in the event of an accident.

7. A safety device as claimed in any preceding claim, wherein the crash detector comprises a breakable member which, in use, is mounted in, on or at a bumper of the motor vehicle so as to be broken upon deformation of said bumper.

8. A safety device as claimed in claim 7, wherein the breakable member is elongate and is mounted within said bumper, laterally to the normal direction of travel of the vehicle.

9. A safety device as claimed in claim 7 or claim 8, wherein the breakable member comprises a narrowed neck portion.

10. A safety device as claimed in any of claims 7 to 9, further comprising mechanically biassed switching means which are normally retained in an "off" position by mechanical connection to the breakable member, wherein breakage of the breakable member causes the switching means to be released into an "on" position.

11. A safety device as claimed in any of claims 7 to 9, wherein the breakable member contains or comprises a conductor arranged to be severed in the event of a crash, and wherein the crash detector further comprises electrical means for actuation of the warning signal upon severance of the conductor.

12. A safety device as claimed in any of claims 7 to 11, further comprising at least one breaking member mounted within the bumper and arranged to transmit deformation of the bumper to the breakable member.

13. A safety device as claimed in claim 12, wherein the breakable member and the braking member(s) are mounted within a bumper liner.

14. A safety device as claimed in any of claims 7 to 13, wherein the breakable member comprises side portions which extend longitudinally to the normal direction of travel of the motor vehicle and are disposed within side portions of said bumper.

15. A safety device as claimed in any preceding claim, wherein the crash detector comprises an inertial impact detector.

16. A safety device as claimed in any preceding claim, wherein the crash detector includes one or more strain gauges disposed on the vehicle body and/or chassis and- adapted to provide electrical signals for actuating said warning signal in the event that part of the body or chassis is distorted to a predetermined extent.

17. A safety device for a motor vehicle having a crash detector substantially as herein described with reference to, and as illustrated in, the accompanying drawing.