GB2375509A - An airbag deployment limiting means - Google Patents

Abstract

An airbag restraint comprises a durable fabric enclosure 12 for fitting over a steering wheel to provide a complete cover over the front face of the steering wheel, and to enclose a substantial part of the rear of the steering wheel, strap means 16, 17 for securing the enclosure 12 to the steering wheel, and bursting devices 24 carried within the enclosure and protruding towards the front face of the steering wheel when the enclosure is fitted to the steering wheel for bursting an airbag as it deploys. Preferably the airbag restraint is made from two discs of a woven nylon fabric stitched together around their periphery and has a relatively rigid disc of material bonded to the front disc to provide a base for the bursting devices which may be eight sharp spikes 24. Advantageously the airbag restraint provides a device which prevents the unintentional deployment of a vehicle steering wheel airbag in operations such as emergency and rescue.

Description

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AIRBAG RESTRAINT This invention relates to an airbag restraint, that is to say a safety device suitable for use by emergency services and the like for preventing the unintentional deployment of a vehicle steering wheel airbag.

It is recognised that there are vehicle collisions in which vehicle occupants are trapped or injured, and in which the airbag contained within the steering wheel of the vehicle has not deployed. There have been incidents in which such airbags have deployed unintentionally during a rescue operation in which emergency service personnel are attempting to extricate occupants from the vehicle. It is known for such unintentional deployment of an airbag to injure emergency services personnel and/or vehicle occupants.

It has previously been proposed to minimise this danger by means of a device known generally as the"Bag Buster"which is fitted by emergency services personnel to the steering wheel before a rescue attempt is made. The"Bag Buster" consists of a substantial metal disc which is secured by clips to the front face of the steering wheel of the vehicle and which incorporates spikes projecting towards the steering wheel. Normally the securing clips space the plate by a small distance from the steering wheel, and an airbag deploying behind the plate is restrained by the plate, and punctured by the spikes of the plate. However, in some instances the airbag can protrude dangerously, during deployment, between the steering wheel and the plate of the"Bag Buster". Furthermore, debris generated by the deployment and subsequent bursting of the airbag can prove hazardous. In an attempt to minimise this difficulty it has been known to use the"Bag Buster"in conjunction with a

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lightweight fabric bag which is placed over the"Bag Buster"and the steering wheel after the"Bag Buster"has been fitted to the steering wheel. While this solution does minimise the difficulty, it has inherent problems in that it requires two separate items to be fitted to the steering wheel. Furthermore, it requires the emergency services personnel, in an emergency situation, to carry two separate components, the"Bag Buster"and the fabric cover, and to fit the two rather than simply fitting one of the two.

It is an object of the present invention to provide an airbag restraint wherein this difficulty is overcome.

In accordance with the present invention there is provided an airbag restraint comprising a durable fabric enclosure for fitting over a steering wheel to provide a complete cover over the front face of the steering wheel, and to enclose a substantial part of the rear of the steering wheel, strap means for securing the enclosure to the steering wheel, and bursting devices carried within the enclosure and protruding towards the front face of the steering wheel when the enclosure is fitted to the steering wheel for bursting an airbag as it deploys.

Preferably the enclosure includes adjustment means for adjusting the size of the enclosure to suit different steering wheel sizes.

One example of the invention is illustrated in the accompanying drawings wherein Figure 1 is a front elevational view of an airbag restraint, Figure 2 is a rear elevational view of the restraint of Figure 1, Figure 3 is a diagrammatic representation illustrating the arrangement of spikes of the

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restraint of Figures 1 and 2, and Figure 4 is a side elevational view of one of the spikes of Figure 3.

Referring to the drawings, the airbag restraint comprises front and rear discs 11,12 of a robust woven nylon fabric material. The two discs, which are generally circular, are stitched together around their periphery to provide an internal seam. The rear disc 12 is formed with an elliptical aperture 13 from which first and second slits 14,15 extend to the periphery of the disc.

The diameter of the discs 11,12 exceeds the diameter of the majority of steering wheels utilised in passenger vehicles, and the slits 14,15 and the aperture 13 provide an opening whereby the enclosure defined by the interconnected discs 11,12 can be fitted over a steering wheel so that the receiving wheel is received within the enclosure and the steering column extends through the aperture 13.

In order to secure the enclosure to the steering wheel there are provided first and second straps 16,17. The straps are securely stitched at one end to the rear disc 12, and extend, crossing over one another, across the aperture 13 to protrude beyond the periphery of the enclosure. The free end regions of the straps 16,17 adjustably carry buckle tongues 18,19 which can co-operate with push button release buckles 21,22 secured to short lengths of strap securely stitched to the front disc 11. The tongues and buckles operate in the same manner as the tongues and buckles of conventional vehicle seatbelts.

Thus the strap 16 is folded around the periphery of the enclosure when it is fitted over the steering wheel and its tongue 18 is clipped into the buckle 22.

Similarly the tongue 19 of the strap 17 is clipped into the buckle 21. The

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straps 16,17 thus provide a secure, and adjustable fixing of the enclosure to the steering wheel.

Additionally, an adjustable length strap 23 is secured at its ends to the front and rear discs 11,12 such that adjustment of the length of the strap between its ends will fold part of the enclosure around the steering wheel periphery to accommodate a smaller steering wheel.

The rear face of the front disc 11 is provided with a circular array of eight equiangularly spaced spikes 24 which consist of a broad base and a pointed protrusion 26. The bases of the spikes are secured to the rear face of the front disc 11 in any convenient manner and the array is disposed adjacent the region of the disc which will overlie the airbag container of the steering wheel. Normally, for most steering wheels, this will be either central to the steering wheel, or more often displaced slightly towards the lower periphery of the steering wheel, when the steering wheel is in the'straight ahead' position. The spikes thus provide eight sharp protrusions in the path of expansion of the airbag should the airbag be deployed, and one or more of the sharp protrusions will puncture the airbag thus preventing it deploying.

Should the airbag deploy to any significant extent then it will be contained by the enclosure of the discs 11,12. It will be recognised that the number, arrangement and positioning of the spikes may vary from that described above and different configurations may be preferred for different applications.

O. Irm In a modification the spikes 24 are secured to a relatively rigid disc of kevlar or similar material which is bonded or otherwise secured to the rear face of

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the front disc 11. Such a disc provides a more rigid base for the spikes 24, and thus enhances their bursting effect upon a deploying airbag.

Desirably the discs 11,12 are produced in a material of a bright colour, for example bright yellow. The straps 16,17 are produced in two different colours, for example red and blue, and the short straps which carry the buckles 21,22 are correspondingly coloured such that the strap of the buckle 21 is blue, and the strap of the buckle 22 is red. The user can then see, at a glance, that the tongue 18 should be clipped into the buckle 22 since the straps are of the same colour, and similarly the tongue 19 should be clipped into the buckle 21 since their straps are of the same colour. The risks of the straps being fitted, without being crossed over behind the steering wheel, is thus greatly minimise. Conveniently, the strap 23 will be of a different colour so that there is no risk of confusion.

As illustrated in Figures 1 and 2, the front disc 11 can be printed with warning messages, and, if desired, a logo, while further warning messages and instructions can be printed on the outer surface of the rear disc 12.

It will be recognised that when utilising the airbag restraint described above only one item needs to be carried by the emergency service personnel, and similarly only one item needs to be fitted to the steering wheel. The fitting to the steering wheel is simple and quick using the strap arrangement described, and moveover the adjustability of the strap arrangement (by adjusting the effective strap length) facilitates the accommodation of steering wheels of different diameter and also steering wheels which have been deformed for example as a result of accident damage.

Claims (14)

1. CLAIMS :- 1. An airbag restraint comprising a durable fabric enclosure for fitting over a steering wheel to provide a complete cover over the front face of the steering wheel, and to enclose a substantial part of the rear of the steering wheel, strap means for securing the enclosure to the steering wheel, and bursting devices carried within the enclosure and protruding towards the front face of the steering wheel when the enclosure is fitted to the steering wheel for bursting an airbag as it deploys.
2. 2. An airbag restraint as claimed in claim 1 wherein including adjustment means for adjusting the size of the enclosure to suit different steering wheel sizes.
3. 3. An airbag restraint as claimed in claim 1 wherein said adjustment means comprises an adjustable belt for folding or collapsing part of said enclosure about a steering wheel in use.
4. 4. An airbag restraint as claimed in any one of the preceding claims wherein straps are provided for securing the enclosure in place in use.
5. 5. An airbag restraint as claimed in claim 4 wherein said straps include push button release buckles.
6. 6. An airbag restraint as claimed in claim 5 wherein said buckles are adjustably mounted on their respective straps.

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7. 7. An airbag restraint as claimed in claim 4,5 or 6 wherein said buckles are colour coded so that it is immediately obvious which buckle components are to be interengaged in use
8. 8. An airbag restraint as claimed in any one of the preceding claims wherein said bursting devices are spikes.
9. 9. An airbag restraint as claimed in 8 wherein said spikes are disposed in a circular array.
10. 10. An airbag restraint as claimed in claim 8 or claim 9 wherein said spikes are carried on the part of said enclosure covering the driver facing part of the steering wheel.
11. 11. An airbag restraint as claimed in claim 8 or claim 9 wherein said spikes are carried on a mounting member disposed between said enclosure and the driver facing part of the steering wheel.
12. 12. An airbag restraint as claimed in any one of the preceding claims wherein the enclosure is printed or otherwise provided with warning indicia.
13. 13. An airbag restraint as claimed in any one of the preceding claims wherein the enclosure has a bright colour.
14. 14. An airbag restraint substantially as hereinbefore described with reference to any one of the accompanying drawings.