GB2417465A

GB2417465A - An airbag with two gas supply inlets

Info

Publication number: GB2417465A
Application number: GB0418892A
Authority: GB
Inventors: Remi Baillivet; Adam Machnik
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2004-08-24
Filing date: 2004-08-24
Publication date: 2006-03-01
Also published as: GB0418892D0

Abstract

An air-bag (1) provides protection for an occupant of a vehicle. The air-bag is formed from two superimposed layers of fabric which are interconnected by seams. The layers of fabric define a central region (2) and two side regions (3, 4). Each side region is provided with a gas supply inlet (7, 8). The air-bag is mounted with the gas supply inlets (7, 8) immediately adjacent each other. The air-bag inflates to form a three-dimensional structure. The central and side regions may be provided with tear seams (9,10,18), with those (9,10) of the side regions forming diverging gas flow passages (11-14). The air-bag may be mounted in a steering wheel to provide protection for the driver, or it may be utilised as a passenger side-bag or knee-bag.

Description

24 1 7465

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 for use in a motor vehicle to provide protection for an occupant of the vehicle in the event that an accident should occur. The preferred embodiment of the present invention is in the form of an air-bag to be incorporated in a steering wheel to provide protection for the driver of the vehicle.

It is known that, for an air-bag to provide optimum protection for the occupant of the vehicle, such as the driver of the vehicle, the air-bag should engage with, or couple with, the occupant of the vehicle as soon as possible after an accident situation has been detected. It has been proposed to provide an air-bag which provides such rapid coupling, the air-bag being formed in a three-dimensional manner. Thus the air-bag is not formed simply using two super-imposed layers of fabric which are interconnected by seams, but instead utilises separate layers of fabric which are assembled together to form an air- bag having the desired configuration. However, such air-bags are relatively expensive to manufacture as they require a substantial quantity of fabric and relatively complicated sewing techniques. A typical driver's air-bag, therefore, is formed from two super-imposed layers of material, typically of circular form with a peripheral seal. Gas is injected into the air-bag from an aperture provided at the centre of one of the sheets. The air-bag, when inflated, may present the form of a relatively flat circular cushion or may present the form of a spherical ball, depending upon the presence of any internal restraining straps and upon the pressure of gas supplied. Such an air-bag does not provide optimal early coupling with a driver, but, on the other hand, an air-bag of this type is relatively economic to produce.

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

According to the present invention, there is provided an air-bag to provide protection for an occupant of a vehicle in the event that an accident should occur, the air-bag being formed from two super-imposed layers of fabric which are interconnected by seams, the layers of fabric defining a central region and two side regions, one on each side of the central region, each side region being provided with a gas supply inlet for the introduction of gas into the side region, the air-bag being mounted with the gas supply inlets immediately adjacent each other.

Preferably, each side region is provided with one or more seams to define, within the side region, discrete gas flow passages.

Advantageously, the central region is connected to the side regions so that the central region is inflated by gas supplied to the side regions.

Conveniently, the central region is provided with at least one tear seam.

Preferably, the central region is provided with tear a tear seam adjacent an upper edge of the central region. l

Advantageously, a tear seam in the form of a substantially central tear seam is provided in a central part of the central region.

Conveniently, the central region is provided with an aperture or vent, the aperture or vent being directed towards the point where the gas inlets are located.

Preferably, the air-bag is made using a one-piece-weaving technique.

Advantageously, the air-bag is mounted on a steering wheel.

Alternatively, the air-bag may be in the form of a passenger side bag or in the form of a knee bag.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, embodiments 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 in accordance with the invention in an un-inflated state, FIGRUE 2 is a view illustrating the air-bag of Figure 1 when inflated, FIGURE 3 is a view corresponding to Figure 1 illustrating an alternative form of airbag, and FIGURE 4 is a further view corresponding to Figure 1 illustrating yet another form of air-bag.

Referring initially to Figure 1 of the accompanying drawings, an air-bag in accordance with the present invention is formed from two super-imposed layers of fabric which are interconnected by means of appropriate seams. The seams may be stitched seams or both of the layers of fabric may be produced simultaneously with the seams being produced by a one-pieceweaving technique. Some of the seams may be "tear" seams, that is to say seams which are intended to break when the gas pressure within the airbag reaches a predetermined threshold.

Although the air-bag is made using only two layers of fabric, because of the form of the air-bag, the air-bag, on inflation, presents a threedimensional shape, and part of the air-bag may be moved swiftly into engagement with the vehicle occupant to be protected by the air-bag.

Referring, in detail, to Figure 1, the air-bag 1 is formed from two super imposed layers of fabric of identical shape.

The air-bag 1 presents a generally rectangular central region 2, and to each side of the rectangular region 2, respective triangular side regions 3,4.

Each triangular side region 3,4 tapers to a respective apex 5,6 defining a gas inlet, and at each apex a respective gas supply duct 7,8 is provided. The central part of each triangular region 3,4 is provided with a triangular tear seam 9,10, interconnecting the two layers of fabric and thus in each triangular region there are two diverging gas flow passages. In the triangular region 3 there is an upper gas flow passage 11 and a lower gas flow passage 12 which each extend from the gas supply duct 7 towards the rectangular region 2. Similarly, in the triangular region 4 there is an upper gas flow passage 13 and a lower gas flow passage 14 which extend from the gas supply duct 8 to the rectangular region 2.

The edges of the rectangular region 2 may be defined by tear seams 15, 16 which are provided where a respective triangular region 3,4 abuts against the central rectangular region 2. However, these tear seams may simply be fold- lines in alternative embodiments of the invention Within the upper part of the rectangular region 2 there is an arcuate area 17 constituted by a tear seam interconnecting the two layers of fabric. In a central part of the rectangular region 2 there is a further relatively small rectangular area constituted by a tear seam 18 which again interconnects the two layers of fabric and, adjacent this tear seam 18, in one of the layers of fabric, there is a rectangular opening or exhaust vent 19.

It is to be understood that the triangular regions 3,4 are to be folded inwardly towards the side of the air-bag provided with the vent or aperture 19.

The gas inlets defined by the apices 5,6 of the triangular region 3,4 are to be brought together so as to be immediately adjacent each other and the gas supply ducts 7,8 are both connected to a single source of gas. The entire air-bag is packed within an appropriate housing, with part of the rectangular region 2 being located towards the top of the housing. The housing may be mounted in a steering wheel, such as the steering wheel 20 shown in Figure 2.

On deployment of the air-bag, gas will be supplied through the gas supply ducts 7,8. The gas will flow through the upper and lower gas flow passages 11,12,13,14 within the triangular regions 3,4. The flow of gas will distend the gas flow passages 11,12,13,14, and the gas flow passages will assume an extended substantially rigid configuration due to the pressure of gas.

The triangular regions 3,4 will thus effectively inflate, moving the rectangular region 2 a substantial distance forward. The rectangular region 2 will itself inflate, to form a rectangular cushion, the rectangular cushion being spaced forwardly of the steering wheel 20 by a distance which is determined by the size of the triangular regions 3,4.

The uppermost part of the rectangular cushion 2, as defined by the tear seam 17, will initially remain uninflated. Also, in the region of the rectangular tear seam 18, the cushion will be "dimpled". It has been found that a cushion of this form may offer optimum protection to a vehicle occupant. The uninflated region formed by the tear seam 17 will permit the head of the occupant to move in an appropriate manner, minimising the risk of neck injury.

The dimpled region 18 in the cushion will help minimise chest injury.

It is to be understood that the aperture or vent 19 is present on the face of the rectangular cushion 2 which is directed towards the point where the two gas inlets defined by the apices 5,6 are located and hence away from the vehicle occupant. Thus, any hot gas vented from the air-bag is vented away from the vehicle occupant, into a space which is surrounded by the rectangular cushion 2 and the two triangular regions 3, 4. The hot gas is thus vented in a safe manner.

Whilst, in the described embodiment the rectangular region 2 is to be inflated to form a cushion, it is envisaged that in alternative embodiments of the invention the rectangular region 2 may be noninflatable, so that only the triangular regions 3,4 become inflated.

Figure 3 illustrates a modified embodiment of the invention. In this embodiment of the invention the entire air-bag 30 is of rectangular form, and again the air-bag is formed from two super-imposed layers of fabric. Two gas supply ducts 31,32 are provided which are connected to opposite side edges of the rectangular air-bag 30. Seams, which may be tear seams, 33,34,35,36 are provided within the rectangular air-bag, the seams being located adjacent the two side edges of the air-bag. An arcuate cut-out 37 is provided in the central region of the air-bag towards the lower part of the air-bag.

It is to be understood that, with an air-bag of the type shown in Figure 3, if the gas supply ducts 31,32 are connected to a common source of gas, the air- bag, on inflation, will tend to assume an arcuate form. The regions provided with the seams 33,34,35,36 will be of"ribbed" configuration, and will distend to form substantially rigid side parts which urge the central region of the air bag forwardly away from the source of gas connected to the supply ducts 31 and 32. The advantage of the embodiment of Figure 3 is that it has extreme simplicity, and is very easy and economic to manufacture.

Figure 4 illustrates a further embodiment which is similar to that of Figure 3, and indeed like references are utilised to identify like parts which will not be re-described. However in the air-bag of Figure 4, an upper region of the air-bag, opposite the arcuate cut-out 37, is provided with an arcuate tear seam 38, and a central region of the air-bag, above the cut-out 37 is provided with a central tear seam 39. Also, one layer of the fabric forming the bag of Figure 4 is provided with an aperture or vent 40.

It is to be understood that in use of the air-bag of Figure 4 the aperture or vent 40 will be located on the side of the air-bag which is to be directed away from an occupant to be protected by the air-bag. The tear seam 38 will help ensure that the air-bag presents a form, when inflated, which will minimise the risk of neck injury to the occupant being protected by the air-bag, and similarly the tear seam 39 will help minimise chest injury to the occupant being protected by the air-bag, in a similar way as occurs with the embodiment described above with reference to Figures 1 and 2.

Whilst the invention is being described primarily with reference to airbags of a form intended for use mounted in a steering wheel to provide protection for the driver of the vehicle, it is to be understood that airbags of the general form described may be utilised in a motor vehicle as a side air-bag or as a knee air-bag.

lO When used in this Specification and Claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

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 to provide protection for an occupant of a vehicle

in the event that an accident should occur, the air-bag being formed from two super- imposed layers of fabric which are interconnected by seams, the layers of fabric defining a central region and two side regions, one on each side of the central region, each side region being provided with a gas supply inlet for the introduction of gas into the side region, the air-bag being mounted with the gas supply inlets immediately adjacent each other.
2. An air-bag according to Claim 1 wherein each side region is provided with one or more seams to define, within the side region, discrete gas flow 1 5 passages.
3. An air-bag according to Claim 1 or 2 wherein the central region is connected to the side regions so that the central region is inflated by gas supplied to the side regions.
4. An air-bag according to Claim 3 wherein the central region is provided with at least one tear seam.
5. An arrangement according to any preceding Claim wherein the central region is provided with tear a tear seam adjacent an upper edge of the central region.
6. An air-bag according to any preceding Claim wherein a tear seam in the form of a substantially central tear seam is provided in a central part of the central region.
7. An air-bag according to any preceding Claims wherein the central region is provided with an aperture or vent, the aperture or vent being directed towards the point where the gas inlets are located.
8. An air-bag according to any one of the preceding Claims made using a one piece weaving technique.
9. An air-bag according to any one of the preceding Claims mounted on a steering wheel.
10. An air-bag according to any one of the Claims 1 to 8 in the form of a passenger side-bag.
11. An air-bag according to any one of Claims 1 to 8 in the form of a knee- bag.
12. An air-bag substantially as herein described with reference to and as shown in Figures 1 and 2 of the accompanying drawings.
13. An air-bag substantially as herein described with reference to and as shown in Figures I and 2 as modified by Figure 3 of the accompanying drawings.
14. An air-bag substantially as herein described with reference to and as shown in Figures 1 and 2 as modified by Figure 4 of the accompanying drawings.
15. Any novel feature or combination of features disclosed herein.