GB2268124A

GB2268124A - An air-bag arrangement

Info

Publication number: GB2268124A
Application number: GB9211666A
Authority: GB
Inventors: Joacim Aigner; Josef Egger; Sonja Ploducks; Werner Muller; Dieter Schaper; Andre Robin; Philippe Suzanne; Simon Valkenburg
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1992-06-02
Filing date: 1992-06-02
Publication date: 1994-01-05
Anticipated expiration: 2012-06-02
Also published as: GB9211666D0; GB2268124B

Abstract

An air-bag arrangement for a motor vehicle comprises an air-bag (1) and a gas generator (2) having an integral outward extending substantially circular flange (5) which engages part of the bag (1) surrounding an aperture formed in the bag (1). A plurality of fixing studs (6, 13) are provided associated with the flange (5). The fixing studs (6, 13) extend through small apertures formed in the bag (1) adjacent the main aperture. The main aperture formed in the bag has a maximum dimension (D2) which is less than the diameter of the flange (D1), but which is greater than the distance between the two fixing studs which are furthest apart (D3). <IMAGE>

Description

DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO AN AIR-BAG ARRANGEMENT" THE PRESENT INVENTION relates to an air-bag arrangement for use in a motor vehicle, and more particularly relates to an air-bag arrangement adapted to be incorporated in a steering wheel assembly of a motor vehicle.

According to this invention there is provided an air-bag arrangement for mounting in a motor vehicle, the arrangement comprising a air-bag, a gas generator to provide gas to inflate the air-bag, the gas generator comprising a canister having an integral outwardly extending substantially circular flange, the flange being located to engage part of the bag surrounding a main aperture formed in the bag, there being a plurality of fixing studs are associated with said flange, the fixing studs extending through small apertures formed in the bag provided adjacent the said main aperture formed in the bag, the main aperture formed in the bag having maximum dimension which is less than the diameter of the flange, and which is greater than the distance between the two of said fixing studs which are furthest apart.

Preferably a substantial part of the canister of the gas generator is located within the air-bag.

Conveniently the air-bag arrangement is adapted to be mounted in the steering wheel or a motor vehicle.

Advantageously the bag, when inflated is round and the main aperture in the bag is of substantially square form, with rounded corners. Alternatively the main aperture is of oval form.

Preferably additional material is provided to form a reinforcing element surrounding the main aperture in the air-bag to reinforce the air-bag. The said small apertures may extend through the reinforcing element. The additional material may be adhered to the material forming the air-bag in the region surrounding the main aperture and/or one or more stitched seams may be provided surrounding the main aperture in the bag.

Conveniently two seams of stitching are provided surrounding the main aperture, one seam of stitching being located between the main aperture and said small apertures, and the second seam of stitching extending around the exterior of the said small apertures.

Conveniently the flange has a greater extent than the extent of said seam or seams so that the flange protects the seams from hot gases developed within the bag on activation of the gas generator.

Advantageously at least one of said small apertures is non-Symmetrically located.

Conveniently the bag and the reinforcing element are formed of fabric and the warp and weft of the fabric forming the bag and the fabric forming the reinforcing element make angles with each side of the aperture in the bag of approximately 22.50, 67.50, 112.50 and 157.50.

Advantageously the peripheral part of the flange which engages the bag has a non-sharpened edge.

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 diagrammatic cross-section view through the essential components of an air-bag assembly in accordance with the invention, adapted to be incorporated in the steering wheel assembly of the vehicle, FIGURE 2 is a plan view of the gas generator and the part of the bag connected to the gas generator of Figure 1, with parts being shown in phantom, FIGURE 3 is a side view of part of the bag of Figure 1 in one condition, FIGURE 4 is a view corresponding to Figure 3 showing the same part of the bag in a different condition, FIGURE 5 illustrates part of the bag adjacent the aperture in the bag indicating the direction of the warp and weft of the fabric making the bag and also illustrating part of a reinforcing element, indicating the direction of the warp and weft of the reinforcing element, and FIGURE 6 is a view, corresponding to Figure 2, of an alternative embodiment of the invention.

Referring initially to Figure 1 an air-bag arrangement comprises an air-bag 1 associated with a gas generator 2, mounted in a housing 3. The housing 3 is dimensioned to be received within an appropriate recess formed in a steering wheel of a motor vehicle. The bag 1, is adapted to be substantially round when inflated.

The gas generator 2 comprises a round canister 4, the major part of which is located in the interior of the bag 1. The canister 4 is provided, in this embodiment, with an integral radially outwardly extending flange 5, of circular form. The flange carries four axially extending bolts 6 which are spaced adjacent the periphery of the flange 5. A central axially extending circular section projection 7 is provided which forms part of the canister for the gas generator, extending from the flange 5 in the same axial direction as the bolts 6.

The projection 7, as can be seen more clearly from Figure 2, extends through an aperture 8 (the main aperture) formed in the air-bag 1. The aperture 8, of this embodiment, is of substantially square form, the corners of the aperture being slightly rounded, as shown at 9 in Figure 2.

The portion of the bag 1 surrounding the square aperture 8 is reinforced with a reinforcing element 10 which is illustrated as being of circular form, but which may have any appropriate peripheral configuration. The reinforcing element 10 may be seamed to the inside of the bag, or to the outside of the bag 1. Whilst the reinforcing element 10 may be secured to the fabric of the bag 1 by means of an appropriate adhesive, it is preferred, in any event, to reinforce the periphery of the aperture 8 by means of a stitched seam 11, and this stitched seam 11 may therefore be used to at least assist in securing the reinforcing element 10 in position. A second reinforcing seam 12 is illustrated in Figure 2, in order to provide greater strength.

Located between the inner seam 11 and the outer seam 12 are four small apertures 13 which are spaced from the periphery of the square aperture 8, the apertures 13 being dimensioned and located to receive the bolts 6 extending axially from the flange 5 as shown in Figure 1.

As can be seen from Figure 2, the apertures 13 are not symmetrically arranged, with one aperture 13' being off-set from the symmetric position. The bolts 6 will similarly arranged, thus ensuring that the gas generator can only be mounted in a single relative position to the air-bag.

As can be seen in Figure 2 the flange 5 (which is shown in phantom) has a greater extent than the extent of the stitched seams 11 and 12. Thus, the flange is located above the stitched seams, serving to protect the stitched seams from the high temperature experienced within the bag 11 when the gas generator is activated. The outer periphery of the flange 5 is rounded or burred so that the flange does not present a sharp edge that can cut the fabric of the bag.

It is to be appreciated, from Figure 1, that the bolts 6, which project through the small apertures 13 formed in the bag can be inserted into apertures 14 provided in the outer housing 3, at appropriate locations.

The apertures 14 surround a relatively large aperture 15 formed in the housing 3, and the gas generator and air-bag can be mounted in position by locating the downwardly projecting portion 7 of the housing to extend through the aperture 15 and by positioning the bolts 6 to extend through the apertures 14. Securing nuts 16 may the be mounted on the bolts and tightened, the portion of the bag engaged by the flange 5 thus being securely trapped or "sandwiched" between the flange 5 and the housing 3, thus securing the bag in position.

As can be seen from Figure 2 the diameter of the flange 5 D1 is greater than the largest dimension D2 of the aperture 8. The aperture 8 is a substantially square aperture and the largest dimension of the aperture is thus the diagonal dimension. Also the longest dimension of the apertures 8 (i.e. the diagonal) is greater than the distance D3 between the two fixing studs 13 which are furthest apart. It is to be observed that this shape of the main aperture 8 enables a relatively large amount of the fabric of the bag to surround each stud 13.

Figure 3 illustrates part of the bag 1 which has been folded in alignment with a diagonal across the aperture 8. The two corners of the aperture which have been folded are identified as corner A and corner B. These corners are then gripped and pulled apart in the direction of the arrows C,D, the bag 1 will then have the configuration illustrated in Figure 4. It is to be noted that, with the bag in this configuration the maximum dimension of the aperture 8 is now greater than the diameter of the flange 5, thus enabling the canister 4 of the gas generator 2 and the associated flange 5 to be readily inserted into the bag 1 through the aperture 8.

Once the canister has been inserted into the bag, the bag can be relaxed and the fabric of the bag can be manipulated so that the gas generator 2 is positioned, relative to the bag, as illustrated in Figure 1.

It is thus to be appreciated that in assembling the gas generator arrangement initially the bag is manipulated as shown in Figures 3 and 4 to enable the gas generator 2 to be located within the bag, and then the gas generator 2 is located relative to the aperture 8 as illustrated in Figure 1 and subsequently the bolts 6 are passed through the apertures 14 and the housing 3 and the nuts 16 are tightened trapping the part of the bag, and the reinforcement, adjacent the aperture 8 between the flange 5 and part of the housing 3.

Referring now to Figure 5 of the drawings, there is illustrated part of the bag 1 adjacent the aperture 8 and part of the reinforcing element 10. The fabric forming the bag 1 has the warp and weft so orientated that on one edge of the aperture 8 the warp makes an angle of 22.50 with the edge of the aperture and the weft makes an angle of 112.50, whereas in the reinforcing fabric the warp 22 makes an angle of 67.50 and the weft 23 makes an angle of 157.50.

Thus, when the reinforcing element is mounted in position on the fabric of the bag, along the edge of the aperture 8 warp and weft extend at 22.50, 67.50, 112.50 and 157.50 relative to the edge of the aperture. This provides maximum strength. It is to be appreciated that warp and weft will run at a similar selection of angles to each of the remaining four sides of the aperture 8. If there is no reinforcement the warp and weft are selected to be each at 450 to each side of the square aperture 8.

Figure 6 is a view corresponding to Figure 2 illustrating a modified embodiment of the invention. In this embodiment the aperture formed in the bag is not a square aperture as in Figure 2, but is an aperture 30 of generally oval form. The aperture is surrounded by a single line of stitching 31 forming reinforcing, and in this embodiment no separate reinforcing element, corresponding to the reinforcing element 10, is provided.

The dimensions D1, D2, D3 (as described with reference to Figure 2) are marked on Figure 6. It is to be appreciated that in inserting the gas generator through the aperture 30, the bag will be folded along the major axis of the aperture 30, and the folded corners of the aperture will again be pulled apart, thus providing the aperture with an effective major dimension which is greater than the diameter of the flange 5 of the housing of the gas generator 2.

Claims

CLAIMS:

1. An air-bag arrangement for mounting in a motor vehicle, the arrangement comprising a air-bag, a gas generator to provide gas to inflate the air-bag, the gas generator comprising a canister having an integral outwardly extending substantially circular flange, the flange being located to engage part of the bag surrounding a main aperture formed in the bag, there being a plurality of fixing studs are associated with said flange, the fixing studs extending through small apertures formed in the bag provided adjacent the said main aperture formed in the bag, the main aperture formed in the bag having maximum dimension which is less than the diameter of the flange, and which is greater than the distance between the two of said fixing studs which are furthest apart.

2. An air-bag arrangement according to Claim 1 in which a substantial part of the canister of the gas generator is located within the air-bag.

3. An air-bag arrangement according to any one of the preceding Claims adapted to be mounted in the steering wheel of a motor vehicle.

4. An air-bag arrangement according to any one of the preceding Claims wherein the bag, when inflated, is round.

5. An air-bag arrangement according to any one of the preceding Claims wherein the main aperture in the bag is of substantially square form.

6. An air-bag arrangement according to Claim 5 wherein the main aperture has rounded corners.

7. An air-bag arrangement according to any one of Claims 1 to 4 wherein the main aperture is of oval form.

8. An air-bag arrangement according to any one of the preceding Claims wherein additional material is provided to form a reinforcing element surrounding the main aperture in the air-bag to reinforce the air-bag.

9. An air-bag arrangement according to Claim 8 wherein the said small apertures extend through the reinforcing element.

10. An air-bag arrangement according to Claim 8 or 9 wherein the additional material is adhered to the material forming the air-bag in the region surrounding the main aperture.

11. An air-bag arrangement according to any one of the preceding Claims wherein one or more stitched seams are provided surrounding the main aperture in the bag.

12. An air-bag arrangement according to Claim 11 wherein two seams of stitching are provided surrounding the aperture, one seam of stitching being located between the main aperture and said small apertures, and the second seam of stitching extending around the exterior of the said small apertures.

13. An air-bag arrangement according to any one of Claims 11 or 12 wherein the flange has a greater extent than the extent of said seam or seams so that the flange protects the seams from hot gases developed within the bag on activation of the gas generator.

14. An air-bag arrangement according to any one of the preceding Claims wherein at least one of said small apertures is non-symmetrically located.

15. An air-bag arrangement according to Claim 9 or any Claim dependent thereon wherein the bag and the reinforcing element are formed of fabric and the warp and weft of the fabric forming the bag and the fabric forming the reinforcing element make angles with each side of the aperture in the bag of approximately 22.50, 67.50, 112.50 and 157.50.

16. An air-bag arrangement according to any one of the preceding Claims wherein the peripheral part of the flange which engages the bag has a non-sharpened edge.

17. An air-bag arrangement substantially as herein described with reference to and as shown in Figures 1 to 5 of the accompanying drawings.

18. An air-bag arrangement substantially as herein described with reference to and as shown in Figure 6 of the accompanying drawings.

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