GB2270882A

GB2270882A - Cover for a vehicle air bag arrangement

Info

Publication number: GB2270882A
Application number: GB9220421A
Authority: GB
Inventors: Dan Persson; Jonas Malmenstam
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1992-09-28
Filing date: 1992-09-28
Publication date: 1994-03-30
Anticipated expiration: 2012-09-28
Also published as: KR940006856A; GB9220421D0; GB2270882B; DE4332080A1; KR100306496B1

Abstract

A housing 2 and a cover 3 are interconnected by a snap joint comprising an aperture 12 in a resilient upwardly extending lug 9 and a projection 14 on a lip 13 of the cover 3. Rivets 18 additionally secure the cover and housing together. <IMAGE>

Description

01 ^70882. z DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO AN

AIR-BAG ARRANGEMENT" THE PRESENT INVENTION relates to an air-bag arrangement and more particularly relates to a housing, having a cover, adapted to contain an air-bag.

It is becoming conventional to provide air-bags in motor vehicles, such as motor cars, such air-bags being adapted to be inflated in the event that an accident arises in order to provide a degree of protection for the driver and passenger in the motor vehicle.

An air-bag of this type may be mounted in the hub of the steering wheel or in the dashboard of the vehicle. In either case the air-bag is contained within a housing which incorporates a cover, typically formed of a plastic material. The cover may have lines of weakness so that, when the air-bag is inflated, the cover will break or give way to permit the air-bag to become fully inflated.

It has been conventional for the cover, typically made of a plastic material, to be fixed to the rest of the housing containing the air-bag using rivets. In assembling an air-bag unit of this type the cover must first be located in its correct position relative to the housing, and then has to -be maintained in that position while rivets are put in place. This is an inconvenient method for assembling a air-bag unit.

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

According to this invention there is provided an air-bag unit comprising a housing or receptacle and a cover, both the housing and the cover being relatively rigid, the housing and the cover being inter-connected by a snap-joint, the snap-joint comprising two elements, the elements being carried respectively by the housing and the cover, at least one of the elements being resilient, the first element carrying at least one abutment, and the other element carrying means to engage said abutment.

Preferably the or each abutment comprises a surface present on a projection formed on the said first element.

Conveniently the means to engage the abutment comprise an aperture formed in the said other element.

Advantageously the resilient element is fixed to or formed integrally with the housing.

Conveniently the resilient element is spaced from an inner receptacle forming part of the housing, the element formed integrally with the cover being located between the inner receptacle and the resilient element.

Preferably the element carrying the means to engage the abutment is the resilient element.

Conveniently the element carried by the cover carries the abutment and is provided with wedging means which move the resilient element from an initial position when the cover is being fixed to the housing.

Preferably the said wedging means are formed o the projection present on the said first element.

Advantageously the housing and the resilient element are made of metal.

Conveniently the cover is formed of a plastics material.

Advantageously the cover and the housing are additionally connected to each other by means of rivets or screws or the like.

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 drawings in which FIGURE 1 is a partial side view of an air-bag housing, FIGURE 2 is a sectional view taken on the line IIII of Figure 1, and FIGURE 3 is an enlarged view of part of Figure 2.

Referring to the drawings an air-bag unit 1 comprises two principal components, namely a receptacle or housing 2 and a cover 3. The receptacle or housing 2 may be made principally of metal and the cover 3 may be made principally of plastic material. The receptacle or housing 2 and the cover 3 are connected together.

The receptacle or housing 2 comprises an inner container 4 having a receptacle 5 and an upstanding side wall 6 which is provided with a plurality of circular apertures 7 therein. An outer part of the housing comprises an outer receptacle 8 underlying the base 5 of the inner receptacle 4. The outer receptacle 8 is provided with upwardly extending lugs 9,10 provided at the sides of the receptacle. The lugs 9, 10 are resilient and can be deflected to the position shown in phantom 91. The lugs 9, 10 are each provided with sets of two apertures. Each set of apertures comprises a first circular aperture 11 being positioned to be substantially aligned with an aperture 7 and being of the same size, and a further aperture 12 being positioned closer to the receptacle 8. Each aperture 12 is of rectangular configuration, as can be seen most clearly from Figure 1, and is larger than the associated circular aperture.

The lugs 9,10 each form part of a snap-joint between the receptacle or housing 2 and the cover 3. The other component of the joint comprises a peripheral downwardly extending lip 13, provided on the housing 3, the lip 13 being provided at its lower edge, with a set of outwardly diricted projections 14 each having a substantially horizontal upper surface 15 which comprises an abutment, and an inclined lower surface 16 which comprises a wedge. Each projection 14 is substantially rectangular and of the same size as an aperture 12. The lip 13 is also provided with a set of circular apertures 17, of the same diameter as the apertures 7 and 11.

A plurality of rivets 18 are provided.

In assembling the air-bag unit illustrated in Figures 1 to 3 initially the cover 3 is lowered into position on the housing or receptacle 2. The depending lip 13 is inserted between the upstanding lugs 9,10 of the outer part of the container or housing and the wall 6 of the inner receptacle 4. The top part of each lug 9,10 will initially be engaged by the inclined lower surfaces 16 of the projections 14. These inclined lower surfaces will act with a camming or wedging action causing the lug 9 or 10 to be bent resiliently outwardly towards the position 91. The projections 14 will then move past the apertures 11, the projections 14 having a greater horizontal width than the diameter of the apertures 11 as can be seen from Figure 1.

When the cover has been moved to its final position, the projections 14 will be aligned with the apertures 12 in the lug 9 or 10 and the lug will return to its initial substantially vertical position with the projections 14 extending through the apertures 12. The horizontal abutment surfaces 15 provided on the projections 14 will then engage the upper parts of the apertures 12 preventing the cover 3 from moving upwardly.

The apertures 17 formed in the depending lip 13 provided on the cover 3 are then co-aligned with the apertures 7 and 11 and rivets 18 may readily be inserted in position extending through the co-aligned apertures. Of course, screws or bolts could be used instead of the rivets.

Whilst the snap-joint has been described with reference to a lug with a plurality of apertures, and a lip with a plurality of projections, a lug with a single aperture, to co-operate with a lip with a single projection could be provided.

Claims

CLAIMS:

1. An air-bag unit comprising a housing or receptacle and a cover, both the housing and the cover being relatively rigid, the housing and the cover being interconnected by a snap-joint, the snap-joint comprising two elements, the elements being carried respectively by the housing and the cover, at least one of the elements being resilient, the first element carrying at least one abutment, and the other element carrying means to engage said abutment.

2. An air-bag unit according to Claim 1 wherein the or each abutment comprises a surface present on a projection formed on the said first element.

3. An air-bag unit according to Claim 1 or 2 wherein the means to engage the abutment comprise an aperture formed in the said other element.

4. An air-bag unit according to any one of the preceding Claims wherein the resilient element is fixed to or formed integrally with the housing.

5. An air-bag unit according to Claim 4 wherein the resilient element is spaced from an inner receptacle forming part of the housing, the element formed integrally with the cover being located between the inner receptacle and the resilient element.

6. An air-bag unit according to any one of the preceding Claims wherein the element carrying the means to engage the abutment is the resilient element.

7. An air-bag unit according to Claim 6 wherein the element carried by the cover carries the abutment and is provided with wedging means which move the resilient element from an initial position when the cover is being fixed to the housing.

8. An air-bag unit according to Claim 7 as dependent on Claim 2 wherein the said wedging means are f ormed on the projection present on the said first element.

9. An air-bag unit according to any one of the preceding Claims wherein the housing and the resilient element are made of metal.

10. An air-bag unit according to any one of the preceding Claims wherein the cover is formed of a plastics material.

11. An air-bag unit according to any one of the preceding Claims wherein the cover and the housing are additionally connected to each other by means of rivets or screws or the like.

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

12. An air-bag unit substantially as herein described with reference to and as shown in the accompanying drawings.

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

00 Amendments to the claims have been filed as follows 1. An air-bag unit comprising a housing or receptacle and a cover, both the housing and the cover being relatively rigid, the housing and the cover being interconnected by a snap-joint, the snap-joint comprising two elements, the elements being carried respectively by the housing and the cover, at least one of the elements being resilient, the first element carrying at least one abutment, and the other element carrying means to engage said abutment, the resilient element being fixed to or formed integrally with the housing.

2. An air-bag unit according to Claim 1 wherein the resilient element is spaced from an inner receptacle forming part of the housing, the element formed integrally with the cover being located between the inner receptacle and the resilient element.

3. An air-bag unit according to Claim 1 or Claim 2 wherein the or each abutment comprises a surface present on a projection formed on the said first element.

4. An air-bag unit according to Claim 1, 2 or 3 wherein the means to engage the abutment comprise an aperture formed in the said other element.

5. An air-bag unit according to any one of the preceding Claims wherein the element carrying the means to engage the abutment is the resilient element.

6. An air-bag unit according to Claim 5 wherein the element carried by the cover carries the abutment and is provided with wedging means which move the resilient element f rom an initial position when the cover is being fixed to the housing.

7. An air-bag unit according to Claim 6 as dependent on Claim 2 wherein the said wedging means are formed on the projection present on the said first element.

8. An air-bag unit according to any one of the preceding Claims wherein the housing and the resilient element are made of metal.

9. An air-bag unit according to any one of the preceding Claims wherein the cover is formed of a plastics material.

10. An air-bag unit according to any one of the preceding Claims wherein the cover and the housing are additionally connected to each other by means of rivets or screws or the like.

11. An air-bag unit substantially as herein described with reference to and as shown in the accompanying drawings.