GB2390339A

GB2390339A - Seat belt mounted airbag

Info

Publication number: GB2390339A
Application number: GB0215387A
Authority: GB
Inventors: Jean Francois Jambut; Perrier Laurent
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2002-07-03
Filing date: 2002-07-03
Publication date: 2004-01-07
Anticipated expiration: 2022-07-03
Also published as: FR2841851B1; JP2004075046A; GB0215387D0; JP4243982B2; FR2841851A1; GB2390339B

Abstract

An air-bag (1) is disclosed which is configured to be mounted on a seat-belt (51 Fig 19) of a seat-belt arrangement provided in the motor vehicle. The air-bag (1) has an inflatable chamber (2) and a gas supply duct to supply gas to inflate the chamber (2). The air-bag (1) is configured, by folding, so that upon inflation, the air-bag (1) will initially move outwardly towards an adjacent door of the motor vehicle, and then forwardly and finally inwardly towards the seat occupant.

Description

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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 adapted to be mounted directly on a seat-belt of a motor vehicle in order to provide protection for an occupant of the vehicle who is wearing the seat-belt if an accident should occur.

It has been proposed previously to provide an air-bag which is initially mounted in position on part of a seat-belt arrangement. In one example the air-

bag is initially mounted in a pouch or pocket which is mounted on the lap portion of a conventional "lap and diagonal" seat-belt. In the event that an accident should occur, the air-bag will inflate. Because the air-bag is mounted on the lap portion of the seat-belt, the air-bag will automatically be positioned in the region in front of the occupant of the seat. Because the air-bag is inflating in a direction away from the occupant, all risk of an air-bag emerging from an air-bag housing and striking, with a substantial force, a vehicle occupant who is out of the ordinary seating position and who is located immediately adjacent the housing is thus avoided.

It is, however, envisaged that problems may arise with the use of an air-

bag mounted on a safety-belt, especially if the occupant of the seat has a child

upon their lap. In such a situation the inflating air-bag may strike the child, or the head of the child, and may cause injuries.

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

According to the present invention, there is provided an air-bag to be mounted on a seat-belt of a seat-belt arrangement in a motor vehicle to provide protection for a seat occupant utilising the seat-belt, the airbag having an inflatable chamber, and a gas-supply duct to supply gas to inflate the chamber, the air-bag being configured such that, on inflation thereof, the inflating air-bag will initially move outwardly towards an adjacent door of the vehicle, and then forwardly and finally inwardly towards the seat occupant.

Preferably, the air-bag comprises a main inflatable chamber, the main inflatable chamber being associated with an extending spout to be connected to the gas-supply duct, there being a gas deflector contained within the spout and extending into the main inflatable chamber, the deflector being positioned to direct gas such that the gas will initially flow to a region of the main inflatable chamber which will be remote from the seat occupant on full inflation of the air-bag. Advantageously, the spout connected to the gas-supply duct a mounting and connector element which has mounting portions adapted to engage a seat-

belt to mount the air-bag to the seat-belt.

Conveniently, the air-bag is folded by initially folding the main inflatable chamber about a first folding axis and a second parallel folding axis, so that the folded air-bag is concertina-folded between the parallel axes to overlie the mounting and connector element; and subsequently one part of the

air-bag is concertina-folded about spaced folding axes which intersect the said first and second folding axes, so as to overlie the mounting and connector element; and finally, a further part of the air-bag is concertina-folded, between said spaced folding axes, to overlie the mounting and connector element.

Preferably, the folded air-bag is retained within a sleeve, the mounting elements projecting beyond the sleeve to enable the air-bag to be mounted to a seat-belt. Advantageously, the air-bag is provided mounted on a seatbelt.

Conveniently, the seat-belt is provided with at least one anti-twist element. Preferably, the anti-twist element is a tube of plastics material.

Advantageously, a cover is provided to cover the seat-belt, the air-bag and the or each anti-twist element.

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 view of one embodiment of an air-bag in accordance with the invention, laid out ready to be folded, FIGURE 2 is a view corresponding to Figure 1 showing a subsequent stage during the folding process,

FIGURE 3 is a view corresponding to Figure 2 showing a subsequent stage during the folding process, FIGURE 4 is view corresponding to Figure 3 showing a subsequent stage during the folding process, FIGURE 5 is a view corresponding to Figure 4 showing a subsequent stage during the folding process, FIGURE 6 is a view corresponding to Figure 5 showing a subsequent stage in the folding process, FIGURE 7 is a view corresponding to Figure 6 showing a subsequent stage of the folding process, FIGURE 8 is a view corresponding to Figure 7 showing the subsequent stage in the folding process, FIGURE 9 is a view corresponding to Figure 8 showing a subsequent stage in the folding process, FIGURE 10 is a view corresponding to Figure 9 showing a subsequent stage in the folding process, FIGURE 1 1 is a view corresponding to Figure 10 showing a subsequent stage in the folding process,

FIGURE 12 is a view corresponding to Figure 11 showing a subsequent stage in the folding process, FIGURE 13 is a view corresponding to Figure 12 showing a subsequent stage in the folding process, FIGURE 14 is a view corresponding to Figure 13 showing a subsequent stage in the folding process, FIGURE 15 is a view corresponding to Figure 14 showing a subsequent stage in the folding process, FIGURE 16 is a view corresponding to Figure 15 showing a subsequent stage in the folding process, FIGURE 17 is a view corresponding to Figure 16 showing a subsequent stage in the folding process, FIGURE 18 is a diagrammatic view showing the air-bag and an associated safety-belt when mounted in a motor vehicle, and FIGURE 19 is a view illustrating the air-bag during inflation thereof Referring initially to Figure 1, an air-bag 1 is provided which is adapted to be mounted on a seat-belt. The air-bag 1 comprises a main inflatable chamber 2 formed from two super-imposed layers of fabric of equivalent size and shape, interconnected by a peripheral seam 3.

The main inflatable chamber 2 is shaped rather as a "comma", having a main substantially circular zone 4 with a tangentially outwardly extending tail 5. The tail 5 effectively forms a filling "spout" which has a terminal open mouth 6. Contained within the filling spout 5, and extending part-way into the main substantially circular zone 4 of the air- bag is an internal deflector 7. The deflector 7 is of hollow conical form, and has an open mouth 8 co-aligned with the open mouth 6 of the spout 5. The deflector 7 extends a substantial distance into the main inflatable chamber 2 beyond the end of the spout 5 and, as will become clear from the following description, serves to direct the flow of gas

into the air-bag during inflation thereof, whilst also protecting parts of the peripheral seam 3 from damage by the gas-flow.

The spout 5 is received within a conical part 9 of a mounting and connecting element 10. The mounting and connecting element 10 is formed of fabric as used to form an air-bag, and in addition to defining the conical region 9 which receives the spout S of the air-bag 1, also defines a cylindrical portion 12 to receive one end of a gas supply duct 13 which extends, in use of the air-bag, to an appropriate gas generator. The mounting and connecting element 10 is also provided with three outwardly extending mounting lugs 14, 15, 16 which, as will become clear from the following description, are used to

mount the air-bag to a seat-belt.

As can be seen from Figure 1, the notional axis of the spout 5 of the air-

bag is not co-aligned with the axis of the gas supply duct 13, but is inclined thereto. In the arrangement as shown in Figure 1, the air-bag is laid-out substantially flat and it can be seen that the major portion of the substantially circular zone 4 of the air-bag is located above the axis of the gas supply duct with a relatively small part being located below the axis of the gas supply duct.

The deflector 7 is so located so as to direct gas upwardly within the airbag on inflation of the air-bag.

In folding the air-bag, the air-bag is initially laid-out as shown in Figure 1, and initially the main inflatable chamber 2 is folded back, as indicated by the arrow 20, about a first vertical folding axis 21. The first vertical folding axis 21 extends across the inner-most end of the deflector 7 so that the deflector 7 is also folded back, the first folding axis 21 being located adjacent the end of the conical region 9 of the connecting and mounting element 10.

Turning now to Figure 2, as a second fold, one-half of the main inflatable chamber 2 is folded back, as indicated by arrow 22, about a second vertical folding axis 23. The second vertical folding axis 23 is parallel with the first folding axis 21, and is located to overlie the right-hand-most fixing lug 14.

After the folding step of Figure 2, there is a further folding step, as indicated by arrow 24 (in Figure 3) in which the very terminal left-hand edge of the inflatable chamber 2 is folded back about a third vertical folding axis 25 which is actually coincident with the first folding axis 21. Thus, during the initial steps, the main inflatable chamber 2 has been folded, with "zig-zag" or "concertina" -folds about vertical axes 21, 23, 25 so that, as shown in Figure 4, the air-bag is now contained between two notional parallel lines, as defined by the second and third vertical folding axes 23 and 25, so as to overlie the connecting and mounting member 10.

The upper-most part of the folded air-bag is now folded downwardly, as indicated by folding arrow 26 in Figure 5, about a first horizontal folding axis 27, which lies adjacent one side edge of the connecting and mounting member 10. The portion that is folded down completely covers the unfolded portion,

which remains in its initial condition. This is the situation shown in Figure 5, from which it is seen that an upper region of the conical part 9 of the mounting and connecting element 10 is also folded downwardly above the first horizontal folding axis 27. Subsequently the upper-most portion of the air-bag is folded back up, together with part of the conical region 9 of the mounting and connecting element 10, as indicated by folding arrow28, about a second horizontal folding axis 29 which is located adjacent the lower edge of the mounting and connecting element 10 adjacent the mounting lugs 14, 15, 16, as shown in figure 6. Thus, part of the initially folded air-bag has been zig-zag or concertina-folded within the confines of the connector and mounting element 10. This zig- zag-folding is continued.

As shown in Figure 7, the upper part of the folded air-bag is folded down, as indicated by folding arrow 30, about the first horizontal folding axis 27 identified above in Figure 5. Subsequently, as shown in Figure 8, a further folding step is effected, as shown by arrow 31, about the second horizontal folding axis 29 as shown in Figure 6.

As shown in Figure 9 there is a further downward fold, as indicated by folding arrow 32 about the first horizontal axis 27, followed, as shown in Figure 10, by a further upward fold-up, as indicated by folding arrow 33 about the second horizontal folding axis 29.

Figure 11 shows a final folding-down step, indicated by folding arrow 34, about the first horizontal folding axis 27, which is followed, as shown in Figure 12, by a final folding-up step indicated by folding arrow 35, about the second horizontal folding axis 29. Thus the portion of the air- bag which was upper-most, and which represented the main inflatable region 2, has been zig

zag or concertina-folded within the confines of the mounting and connector element 10.

Subsequently the portion of the main inflatable chamber 2 which was extending downwardly from the mounting and connector element 10 is zigzag or concertina-folded to overlie the mounting and connector element 10 with an initial upward fold, as shown by arrow 36 in Figure 13 about the second horizontal folding axis 29, which is followed by a further downward fold as shown by arrow 37 in Figure 14 about the first horizontal folding axis 27. The folding of the air-bag itself is completed with a final upward fold, as shown in Figure 15 by folding arrow 38, about the second horizontal folding axis 29.

The air-bag is now folded to lie within the confines of the connector and mounting element as illustrated in Figure 15. Finally the entire folded air-bag is folded downwardly, as shown by folding arrow 39, about the second horizontal folding axis 29 so as to overlie the mounting lugs 14, 15, 16. as shown in Figure 17.

A sleeve (not shown) is provided which is mounted over the folded air-

bag, the sleeve being formed of conventional material used for holding air-bags, for example. The sleeve has slits permitting the mounting lugs 14, 15, 16 to extend through the slits and the sleeve, so as to retain the air-bag in the folded condition.

Figure 18 shows the air-bag in a folded condition, within sleeve 50. The mounting lugs 14, 15, 16 extending from the air-bag through the sleeve have been connected to part of a seat-belt 51. The gas supply duct 13 extends along the seat-belt 51 to a gas generator or inflator 52. At least one anti-twist element in the form of a rectangular elongate plastic tube 53 is provided, which lies around the combination of the seat-belt, the air-bag and the gas supply duct, to

prevent the seat-belt twisting. The combination of the air-bag, within its sleeve 50, the anti-twist element 53 and the gas supply duct 13 are contained within a further cover 54, which can be formed of fabric as is used to manufacture seat covers. It is to be appreciated that when the air-bag is mounted on the seat-

belt 51 in the manner described, the effect is that the part of the lap strap of the seat-belt which is to extend across the lap of a seat occupant wearing the seat-

belt is constituted by the cover 54, with the seat-belt 51 extending through the cover. The cover 55 and its contents are thus not obtrusive, and do not hinder the use of the seat-belt. The anti-twist element 53 helps ensure that the seat-

belt is connected in such a way that the air-bag within its sleeve 50 is on the exterior surface of the seat-belt 51, and is not trapped between the seat-belt and the waist of the person wearing the seat-belt, since this could give rise to severe .. mJurles. In the event that an accident should arise and the air-bag is inflated, gas will pass Mom the inflator 52, through the gas supply duct 13, to inflate the air-

bag. On inflation, the air-bag will rupture the sleeve 50, and will also rupture the cover 54 and, as shown in Figure 20, the air-bag will begin to inflate.

Initially, during the inflation process, the entire air-bag will unfold towards the left, as shown in Figure 20, about the first vertical folding axis 21. Gas from the gas generator 52 will flow, as indicated by the arrow 60, through the deflector 7, and will be directed upwardly inside the air-bag. The gas flow will tend to cause the upper-most portion of the air-bag, as shown, to begin to inflate initially, and gas will flow around the outer periphery of the air-bag, as defined by the seam 3, as indicated by the arrows 61-63. The air will thus be directed towards a zone 64 of the air-bag, within the main substantially circular zone 4, but beneath the point at which the spout S communicates with the

interior of the air-bag. The effect is thus that the air-bag, as a complete entity, tends to rotate towards the occupant of the seat, whilst inflating in a gentle manner as the zig-zag or concertina folds unfold. The zone 64 which serves as a support region of the air-bag is urged into position between the sides and abdomen of the person wearing the seatbelt 31. This region of the air-bag becomes firmly engaged between the thighs and abdomen as the torso of the seat occupant begins to move forwardly as a consequence of the deceleration of the vehicle caused on impact or accident. Thus the zone 64 tends to support the air-bag and retain the air-bag in a predetermined position relative to the occupant. Should the occupant strike the air-bag with movement inclined relative to the longitudinal axis of the vehicle, the air-bag will not move away from the occupant, and the occupant will not be deflected past the air-bag, but instead the occupant will still impinge with the air-bag which will provide an appropriate degree of protection.

It is envisaged that when an air-bag, as described above is inflated, the air-bag will inflate with a gentle motion, thus minimising the risk of any injury to a child on the lap of a person wearing the air-bag, and the air-bag will not inflate straightforwardly, but instead the air-bag will inflate with a rotating surrounding movement, the air-bag first extending outwardly towards the door of the vehicle, and then forwardly towards the windscreen and then finally inwardly towards the occupant of the seat. During this final movement the zone 64 becomes engaged within the space between the thighs and abdomen of the seat occupant.

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 to be mounted on a seat-belt of a seat-belt arrangement in a motor vehicle to provide protection for a seat occupant utilising the seat-belt, the air-bag having an inflatable chamber, and a gas-supply duct to supply gas to inflate the chamber, the air-bag being configured such that, on inflation thereof, the inflating air-bag will initially move outwardly towards an adjacent door of the vehicle, and then forwardly and finally inwardly towards the seat occupant.

2. An air-bag according to Claim 1 wherein the air-bag comprises a main inflatable chamber, the main inflatable chamber being associated with an extending spout to be connected to the gas-supply duct, there being a gas deflector contained within the spout and extending into the main inflatable chamber, the deflector being positioned to direct gas such that the gas will initially flow to a region of the main inflatable chamber which will be remote from the seat occupant on full inflation of the air-bag.

3. An air-bag according to Claim 2 wherein the spout is connected to the gas-supply duct by a mounting and connector element which has mounting portions adapted to engage a seat-belt to mount the air-bag to the seatbelt.

4. An air-bag according to Claim 3 wherein the air-bag is folded by initially folding the main inflatable chamber about a first folding axis and a second parallel folding axis, so that the folded air-bag is concertina-folded between the parallel axes to overlie the mounting and connector element; and subsequently one part of the air-bag is concertinafolded about spaced folding axes which intersect the said first and second folding axes, so as to overlie the mounting and connector element; and finally, a further part of the air-bag is concertina

folded, between said spaced folding axes, to overlie the mounting and connector element.

5. An air-bag according to Claim 4 wherein the folded air-bag is retained within a sleeve, the mounting elements projecting beyond the sleeve to enable the air-bag to be mounted to a seat-belt.

6. An air-bag according to any preceding Claim when mounted on a seat-

belt.

7. An air-bag according to any preceding Claim wherein the seatbelt is provided with at least one anti-twist element.

8. An air-bag according to Claim 7 wherein the anti-twist element is a tube of plastics material.

9. An air-bag according to Claim 7 or 8 wherein a cover is provided to cover the seat-belt, the air-bag and the or each anti-twist element.

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

Any novel feature or combination of features disclosed herein.