GB2401835A

GB2401835A - Improvements in or relating to an air-bag

Info

Publication number: GB2401835A
Application number: GB0311466A
Authority: GB
Inventors: David Stow; Alan Bradburn
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2003-05-19
Filing date: 2003-05-19
Publication date: 2004-11-24
Anticipated expiration: 2023-05-19
Also published as: GB2401835B; GB0311466D0

Abstract

An air-bag (1) which defines at least one inflatable zone (3,9) and a gas flow passage (20). The gas flow passage (20) contains a gas flow duct (21) one end of which is configured to be connected to a gas generator. The gas flow duct (21) is inserted into the gas flow passage (20) such that a terminal end part of the gas flow duct (21) projects through an opening formed in the air-bag (1). An adhesive patch (3) is adhered to the air-bag (1) and the projecting terminal part (29) of the gas flow duct (21) to seal the gas flow duct (21) and to secure the gas flow duct (21) in position relative to the air-bag (1). The air-bag may also have two opposing holes in the gas duct which are sealed using two opposing adhesive patches (51, 50 figure 5).

Description

DESCRIPTION OF INVENTION

"IMPROVEMENTS IN OR RELATING TO AN AIR-BAG" THE PRESENT INVENTION relates to an air-bag and more particularly relates to an air-bag having an inner gas flow duct.

It has been proposed previously to provide various air-bags which, themselves, define a gas flow passage, with an inner gas flow duct within the gas flow passage. The gas flow duct is usually a tubular member, the member having various outlets at positions spaced along the length of the member to permit gas to escape.

US 6,199,989 discloses an air-bag of this type, in which the inner gas flow duct is formed from a single piece of fabric which is folded so that opposed edged thereof contact by a seam which joins together two pieces of fabric which themselves form the air-bag. Thus the gas flow duct is held firmly in position. The function of the gas flow duct is firstly to direct gas to parts of the air-bag which are to be inflated and secondly to help protect the air-bag itself from a very aggressive flow of gas which can be generated by a gas generator, especially if the air-bag has to be inflated within a very brief period of time.

In alternative designs of air-bag, a gas flow duct has been used which is a tubular fabric element, fabricated separately from the air-bag and introduced into the air-bag when the air-bag is at an advanced stage in its fabrication. The S innermost end of the gas flow duct, that is to say the end of the duct within the air-bag, may need to be closed, requiring a stitching operation to be effected on the gas flow duct. More importantly, however, part of the gas flow duct, such as the innermost end of the gas flow duct must be held in position within the air- bag, necessitating a stitching operation through the layers of fabric forming the lO air-bag and also through the end part of the gas flow duct. This stitching requires specialist operatives and also the stitching will pierce the fabric forming the air-bag, and consequently there is a risk that gas within the air-bag may escape from the interior of the air- bag through the holes formed by the stitching, thus leading to premature deflation of the air-bag.

The present inventions seeks to provides an improved air-bag.

According to one aspect of this invention there is provided an air-bag, the air-bag defining at least one inflatable zone and a gas flow passage, the gas flow passage containing a gas-flow duct, one end of the gas-flow duct being configured to be connected to a gas generator, at least part of the gas flow duct projecting through or being exposed through an opening formed in the air-bag, there being an adhesive patch adhered to the air-bag and the projecting or exposed part of the gas flow duct to secure the gas flow duct in position relative to the air-bag.

Preferably the gas flow duct is a tubular duct formed of fabric.

Conveniently the air-bag is in the form of an inflatable curtain, the inflatable curtain defining a plurality of inflatable cells, the gas flow duct having gas outlets positioned to direct gas from the gas flow duct into the

inflatable cells.

In one embodiment the other end of the gas flow duct extends through said opening.

Preferably the adhesive patch seals the said other end of the gas flow duct.

Conveniently stitching is provided passing through the patch and at least the end part of the gas flow duct.

In an alternative embodiment there are two openings formed in the airbag on opposed sides of the gas flow duct, exposing two parts of the gas flow duct, there being two adhesive patches, each securing a respective exposed part of the gas flow duct in position relative to the airbag.

The invention also provides a method of making an air-bag, the method comprising the steps of making an air-bag having at least one inflatable zone and a gas flow passage, inserting a gas flow duct into the gas flow passage with a part of the gas flow duct projecting through or being exposed through an opening formed in the air-bag, and applying an adhesive patch to the said exposed part of the gas flow duct and the adjacent part of the air-bag to secure the gas flow duct in position relative to the rest of the air-bag.

Conveniently the adhesive patch is applied to a terminal end part of the gas flow duct that projects through said opening to secure the said end part in position and to seal the said end part.

The patch may be such that one half of one face of the patch is coated with adhesive, but alternatively the patch has the whole of one face coated with adhesive.

Conveniently after securing the patch in position, stitching is provided passing through the patch and at least the end part of the gas flow duct.

In al alternative method there are two openings formed in the air-bag on opposed sides of the gas flow duct, exposing two parts of the gas flow duct, the method comprising applying two adhesive patches, with each patch securing a respective exposed part of the gas flow duct to the air- bag.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, an embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a diagrammatic view of an airbag during manufacture thereof, ! FIGURE 2 is a view of part of the airbag of Figure I during a subsequent stage of manufacture, FIGURE 3 is a view corresponding to Figure 2 showing the air-bag in a final stage of manufacture, FIGURE 4 is a view of part of another air-bag during manufacture, and s FIG LJRE 5 is a sectional view of the airbag of Figure 4.

Referring initially to Figure 1, an air-bag 1 is shown which is an airbag intended to be used as an inflatable side curtain in a motor vehicle. The air lO bag l is of conventional design having a rectangular inflatable area 2 which includes a first inflatable region 3 divided into three vertical cells 4, 5, 6 by means of seams 7, 8 and a second inflatable region 9 divided into three inflatable vertical cells lO, 11, 12 by means of seams 13 and 14. An uninflatable zone 15 is provided between the two inflatable zones 3 and 9.

Securing straps 16 extend from the opposed ends of the rectangular region 2. The uppermost edge of the rectangular region 2 is provided with a plurality of mounting lugs 17, 18, 19. The uppermost part of the rectangular region 2 defines a gas flow passage 20 and received within the gas flow passage is fabric cylindrical tubular gas flow duct 21. A first terminal region 22 of the gas flow duct projects from one side of the rectangular region 2 and may be connected to a gas generator. At intermediate positions along the length of the gas flow duct 21 openings or apertures 23, 24, 25, 26, 27 and 28 are provided. Each opening is aligned with the uppermost part of the respective cell 4, 5, 6, l O. l l, 12. The other terminal end region 29 of the gas flow duct projects a partial distance through an opening formed in the other side of the rectangular region 2.

In order to secure the end 29 of the gas flow duct 22 in position relative to the main part of the air-bag 1, and also to seal the end 29 of the gas flow duct, a rectangular patch 30 is used as shown in Figure 2, at least one half of the surface of the patch 30 being covered with adhesive 31. The adhesive coated part of the patch 30 is pressed firmly into engagement with the part of the air bag I adjacent the projecting end 29 of the gas flow duct 21 and also into contact with the projecting end 29 of the gas flow duct 21, in such a way that part of the adhesive coating 31 on the patch 30 extends beyond the end of the duct 21. This is the situation shown in Figure 2. The adhesive patch 30 is then folded about a fold-line 33 coincident with the end of the adhesive coating 31, with the folded back part of the patch engaging the other side of the gas flow duct 21 and also the other side of the air-bag 1. The adhesive coating 31 effects a tight bond which initially seals the open end 29 of the gas flow duct 21 and which additionally secures the end 29 of the gas flow duct 21 to part of the air bag 1, also, of course, sealing the opening in the air-bag 1 through which the end of the gas flow duct 21 projects. This is the situation shown in Figure 3.

The air-bag can now be deployed by injecting gas, from a gas generator, into the end 22 of the gas flow duct 21. Gas will flow along the gas flow duct, passing through the openings 23 to 28 and thus being injected into the cells 4 to 6 and 10 to 12, causing the air-bag to inflate rapidly. No gas will escape through the originally open end 29 of the gas flow duct 21, and the end 29 of the gas flow duct will be held firmly in position relative to the rest of the air bag.

Whilst the invention has been described with reference to am embodiment in which the patch is provided with an adhesive coating on only part of one surface thereof, in a preferred embodiment the whole of one surface is provided with adhesive.

After the patch has been placed in position a stitching process may be used to reinforced the effect of the patch. Since the stitching will pass through the adhesive coated patch, the risk of gas escaping from the airbag through stitch holes is minimal.

Referring now to Figures 4 and 5, in an alternative embodiment of the invention an air-bag 40, which corresponds to the air-bag l described above, has an upper edge with mounting lugs 41, and a gas flow passage 42 within the airbag adjacent the upper edge. The inflatable region of the airbag includes cells 43, 444, separated by seams such as the seam 45. A gas flow duct 46 is shown in position within the gas flow passage, the gas flow duct have a sealed end 47. The end of the gas flow duct 46, which may be of fabric, may be sealed by stitching before the duct 46 is inserted into the airbag 40. The gas flow duct 46 has openings, such as the opening 48, to direct gas into the cells, such as the cell 44.

in the illustrated embodiment two openings or 'windows' are cut in the airbag on opposite sides of the gas flow passage 42 - only one window 49 being visible in Figure 4. When the gas flow duct is inserted into the airbag two separate parts of the gas flow duct 46 are exposed through the openings. Two adhesive coated patches are provided which are then each put in position to I engage both the air-bag adjacent a respective one of the openings, and the exposed part of the gas flow duct 46 to secure the gas flow duct in position relative the rest of the air-bag 40. Each adhesive patch 50, 51 is larger than the respective opening, such as the opening 49, so that the patch will completely overlie the opening, and seal the opening, thus maintaining the integrity of the airbag. As the adhesive patches only engage the exterior of the gas flow duct 46, gas can flow through the duct past the patches.

Openings or windows equivalent to the opening 49 can be provided at positions spaced apart along the length of the gas flow duct 46 is required. It is envisaged that, in one embodiment, windows or openings equivalent to the opening 49 may be provided at the "open" end of the gas flow duct which is to be connected to a gas generator, to secure that end of the duct to the air-bag, thus effectively preventing the gas generator from being inadvertently inserted into the gas flow passage in the airbag instead of being connected to the gas flow duct itself. Adhesive patches and openings such as the opening 49 may be provided at one or more positions along the length of the gas flow duct terminated with an adhesive patch as shown in Figures 2 and 3.

In the present Specification "comprises" means "includes or consists of" and "comprising" means "including or consisting of".

The features disclosed in the foregoing description, or the following Claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS: 1. An air-bag, the air-bag defining at least one inflatable zone

and a gas flow passage, the gas flow passage containing a gas-flow duct, one end of the gas-flow duct being configured to be connected to a gas generator, at least part of the gas flow duct projecting through or being exposed through an opening formed in the air-bag, there being an adhesive patch adhered to the air-bag and the projecting or exposed part of the gas flow duct to secure the gas flow duct in position relative to the airbag. i
2. An air-bag according to Claim 1 wherein the gas flow duct is a tubular duct formed of fabric.
3. An air-bag according to Claim 1 or Claim 2 wherein the air-bag is in the fore, of an inflatable curtain, the inflatable curtain defining a plurality of inflatable cells, the gas flow duct having gas outlets positioned to direct gas from the gas flow duct into the inflatable cells.
4. An air-bag according to any one of the preceding Claims wherein the other end of the gas flow duct extends through said opening. I
5. An air-bag according to Claim 4 wherein the adhesive patch seals the said other end of the gas flow duct.
6. An air-bag according to claim 3, 4, or 5 wherein stitching is provided passing through the patch and at least the end part of the gas flow duct.
7. An air-bag according to any one of Claims I to 3 wherein there are two openings formed in the airbag on opposed sides of the gas flow duct, exposing two parts of the gas flow duct, there being two adhesive patches, each securing a respective exposed part of the gas flow duct in position relative to the airbag.
8. A method of making an air-bag, the method comprising the steps of making an air-bag having at least one inflatable zone and a gas flow passage, inserting a gas flow duct into the gas flow passage with a part of the gas flow duct projecting through or being exposed through an opening formed in the air- bag, and applying an adhesive patch to the said exposed part of the gas flow duct and the adjacent part of the air-bag to secure the gas flow duct in position relative to the rest of the air-bag.
9. A method according to claim 8 wherein the adhesive patch is applied to a terminal end part of the gas flow duct that projects through said opening to secure the said end part in position and to seal the said end part.
10. A method according to Claim 9 wherein the patch is such that one half of one face of the patch is coated with adhesive.
11. A method according to Claim 9 wherein the patch has the whole of one face coated with adhesive.
12. A method according to any one of Claims 9 to 11 wherein after securing the patch in position, stitching is provided passing through the patch and at least the end part of the gas flow duct.
13. A method according to Claim 8 wherein there are two openings formed in the air-bag on opposed sides of the gas flow duct, exposing two parts of the gas flow duct, the method comprising applying two adhesive patches, with each patch securing a respective exposed part of the gas flow duct to the air-bag.
14. An air-bag substantially as herein described with reference to and as shown in Figures 1 to 3 of the accompanying drawings.
15. An air-bag substantially as herein described with reference to and as shown in Figures 4 and 5 of the accompanying drawings.
16. A method of making an air-bag substantially as herein described with reference to and as shown in Figures 1 to 3 of the accompanying drawings.
17. A method of making an air-bag substantially as herein described with reference to and as shown in Figures 4 and 5 of the accompanying drawings.
18. Any novel feature or combination of features disclosed herein.