GB2270884A

GB2270884A - Vehicle air bag cover

Info

Publication number: GB2270884A
Application number: GB9220474A
Authority: GB
Inventors: Jonas Malmenstam; Lars-Gunnar Skoette
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1992-09-29
Filing date: 1992-09-29
Publication date: 1994-03-30
Anticipated expiration: 2012-09-29
Also published as: GB9220474D0; DE4332079A1; DE4332079C2; KR100306497B1; GB2270884B; KR940006858A

Abstract

The cover 7 comprises an inner layer 8 and an outer layer 14 with the outer layer preferably being non-chemically connected or bonded to the inner layer. The inner layer is provided with an outwardly extending flange 12 and the terminal edge 17 of the outer layer lies immediately adjacent the flange so that the flange covers the interface or connection between the outer layer and the inner layer. <IMAGE>

Description

2270884 DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO AN

AIR-BAG COVER" THE PRESENT INVENTION relates to an air-bag cover and more particularly relates to a cover for an air-bag unit intended for use in a motor vehicle such as a motor car.

It is becoming conventional to provide a motor vehicle, such as a motor car, with one or more air-bags, these comprising bags adapted to be inflated in the event that an accident should arise to provide some protection for the drives and/or passenger within the motor vehicle.

The air-bag is contained within an air-bag unit which is provided with a cover. The air-bag unit may be located within the hub of the steering wheel or in the dashboard.

The cover for a typical air-bag unit is formed of two layers, namely an inner layer which is relatively stiff and provides the necessary rigidity and strength for the cover, and an outer layer which is made of a softer material, which provides the air-bag unit with a desirable exterior appearance and "feelO.

A problem with prior proposed air-bag units is that, at the peripheral edge of the cover of the-air-bag unit the join between the inner layer and the outer layer is visible and/or accessible. This means that special bonding is required between the inner layer and the outer 1 1 layer, particularly in this region, if undesirable peelingapart of the layers is to be avoided.

The present invention seeks to provide an improved cover for an air-bag unit.

According to this invention there is provided a cover for an air-bag unit, the cover comprising an inner layer and an -outer layer, the inner layer being provided with an outwardly extending flange, the terminal edge of the outer layer lying immediately adjacent the flange so that the flange covers the inter-face or connection between the outer layer and the inner layer.

Preferably the flange is formed integrally with the inner layer.

Conveniently the flange extends substantially perpendicularly from the part of the inner layer carrying the flange.

Advantageously the cover has a top surface with depending side walls, the outer layer covering at least part of the side walls.

Preferably the inner layer is formed of a relatively still material and the outer layer is formed of a softer material.

Preferably the outer layer is non-chemically connected or bonded to the inner layer.

The outer layer may be ultrasonically welded or solvent welded to the inner layer. In a preferred embodiment of the invention the outer layer is provided with a plurality of integrally f ormed button elements which pass through apertures provided in the inner layer to bond the outer layer to the inner layer.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described. by way of example, with reference to the accompanying drawing which is a sectional view of part of an air-bag unit incorporating a cover in accordance with the invention.

Referring to the drawing an air-bag unit 1 comprises a housing or container 2 made of metal and having a bottom or base 3 with a peripheral upstanding side wall 4, that side wall being provided with a plurality of apertures 5 adapted to receive rivets 6.

A cover 7 is mounted in position on the housing 2, the cover 7 comprising an inner layer 8 made of plastic material, the inner layer being relatively rigid and defining an upper part 9 of the housing and a depending side wall 10, the depending side wall 10 containing apertures 11 adapted to be aligned with the apertures 5 and for receiving the rivets 6. The depending side wall 10 is provided with an integrally formed outwardly extending flange 12, which extends substantially perpendicularly to the side wall, presenting a substantially horizontal upper surface 13.

The cover 7 also incorporates an outer layer 14 made of a plastics material, the material f orming the outer layer 14 being somewhat "softer" than the material forming the inner layer 8. The outer layer 14 extends, 15, across the top of the housing and also extends 16 adjacent the upper part of the side wall 10. The outer layer, however, terminates adjacent the flange 13, the outer surface 17 of the portion 16 being substantially aligned with the free edge of the flange 12.

It is to be noted that the outer layer 14 is integrally formed with a plurality of button elements 18 each comprising a shank and enlarged head, the button elements being adapted to co-operate with apertures 19 provided for that purpose in the inner layer 8. The button elements serve to bond the outer layer to the inner layer in a non-chemical manner. Alternate non-chemical techniques may be used to bond the outer layer to the inner layer, for example sonic welding or solvent welding. It is to be appreciated that it may be practicable to utilise chemical bonding, with the outer layer being formed in,situ and chemically bonded to the inner layer, especially if the outer layer is formed of a foamed or expanded material. If the outer layer is moulded in situ in this way the region at the free edge of the f lange 12, at the interf ace with the outer surface of the part 16 of the outer layer 14 may be rounded to facilitate the moulding of the outer layer.

It is to be appreciated, in any event, that the inner layer is provided with an outwardly extending flange, and the outer layer terminates in abutment with the flange, the flange thus effectively concealing the connection or inter-face between the inner layer and the outer layer in the region of the side wall of the cover.

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Claims

CLAIMS:

1. A cover for an air-bag unit, the cover comprising an inner layer and an outer layer, the inner layer being provided with an outwardly extending flange, the terminal edge of the outer layer lying immediately adjacent the flange so that the flange covers the inter-face or connection between the outer layer and the inner layer.

2. An air-bag cover according to Claim 1 wherein the flange is formed integrally with the inner layer.

3. An air-bag cover according to Claim 1 or Claim 2 wherein the flange extends substantially perpendicularly from the part of the inner layer carrying the flange.

4. An air-bag cover according to any one of the preceding Claims wherein the cover has a top surface with depending side walls, the outer layer covering at least part of the side walls.

5. An air-bag cover according to any one of the preceding Claims wherein the inner layer is formed of a relatively stiff material and the outer layer is formed of a softer material.

6. An air-bag cover according to any one of the preceding Claims wherein the outer layer is non-chemically connected or bonded to the inner layer.

7. An air-bag cover according to Claim 6 wherein the outer layer is ultrasonically welded to the inner layer.

4 An air-bag cover according to Claim 6 wherein the outer layer is solvent welded to the inner layer.

9. " An air-bag cover according to Claim 6 wherein the outer layer is provided with a plurality of integrally formed button elements which pass through apertures provided in the inner layer to bond the outer layer to the inner layer.

10. Any novel feature or combination of features disclosed herein.

10. An air-bag cover substantially as herein described with reference to and as shown in the accompanying drawing.

11. Any novel feature or combination of features disclosed herein.

Amendments to the claims have been filed as follows A cover for an air-bag unit, the cover comprising an inner layer and an outer layer, the outer layer being non-chemically connected or bonded to the inner layer, the inner layer being provided with an outwardly extending flange, the terminal edge of the outer layer lying immediately adjacent the flange so that the flange covers the inter-face or connection between the outer layer and the inner layer.

6. An air-bag cover according to any one of the preceding Claims wherein the outer layer is ultrasonically welded to the inner layer.

7. An air-bag cover according to any one of Claims 1 to 5 wherein the outer layer is solvent welded to the inner layer.

8. An air-bag cover according to any one of Claims 1 to 5 wherein the outer layer is provided with a plurality of integrally formed button elements which pass through apertures provided in the inner layer to bond the outer layer to the inner layer.

9. An air-bag cover substantially as herein described with reference to and as shown in the accompanying drawing.