GB2364975A

GB2364975A - Air bag and housing mounting arrangement

Info

Publication number: GB2364975A
Application number: GB0123466A
Authority: GB
Inventors: Jan Valkenburg
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1997-11-07
Filing date: 1997-11-07
Publication date: 2002-02-13
Anticipated expiration: 2017-11-07
Also published as: GB9723614D0; GB0123466D0; GB2364974B; GB2331491B; GB2364974A; GB2331491A8; GB2331491A; GB0123464D0; GB2364975B

Abstract

An air bag arrangement incorporates a housing 1 which is of elongate form and of substantially uniform cross-section. The housing defines a chamber which receives an air bag 2, parts of the housing which define the chamber being inter-connected by a snap-fastening joint 6,7. The air bag is provided with apertured mounting tabs (15, figure 2) which pass trough slots (14) communicating with the chamber, and which are aligned with apertures 11 defined by the housing to accept mounting means for mounting the combination in position. The snap-fastening joint may comprise a socket 6 and bead 7 (as shown), or it may comprise two adjacent lips (26,27 figure 3) and clips (33) for securing the lips adjacent one another. The housing may be provided with a mechanical line of weakness (51, figure 4) and be formed as an extrusion of plastics material.

Description

<Desc/Clms Page number 1> DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO AN AIRBAG ARRANGEMENT" THE PRESENT INVENTION relates to a housing for an airbag and relates to a combination of a housing and an airbag.

It has been proposed to provide airbags at various positions within motor vehicles, the airbags being adapted to inflate in the event that an accident should occur, to provide protection for the driver of the vehicle or other occupant of the vehicle.

In particular, it has been proposed to provide airbags which, before inflation, extend across the top of the door opening in a motor vehicle and at least part way down the "A"-Post. Such airbags may be termed "side-curtain" air- bags and, typically, when such an airbag is inflated it forms a substantially rigid structure extending along the side of the vehicle between the occupant of the vehicle and the windows present in the door or doors of the vehicle. Such a "side-curtain" may serve to prevent the head of the occupant of the vehicle from hitting the side of the vehicle or being thrown out through the window opening in the event of aside impact or in the event of a roll-over.

It is most convenient to be able to pack an airbag in a housing, and then install the housing, complete with the airbag within it, into a motor vehicle. If an airbag is to be mounted in position in a channel or recess extending over the door opening of a vehicle and part way down the "A"-Post, the airbag should be contained in an elongate housing that can be fitted in position in an unobtrusive manner. The present invention seeks to provide a housing of this type.

According to this invention there is provided a housing for an airbag, the housing being of elongate form and being of substantially uniform cross- section, parts of the housing defming a chamber adapted to receive an airbag, the said parts of the housing being interconnected by a snap-fastening joint, wherein the airbag is provided with a plurality of apertured lugs, the apertured lugs passing through slots communicating with the chamber, and being aligned with apertures defined by the housing to accept mounting means for mounting the combination in position.

Preferably the housing comprises an extending wall portion provided with apertures to facilitate the fixing of the housing in position.

Conveniently the housing is formed as an extrusion of an appropriate plastics material.

Advantageously the snap-fastening joint comprises a socket and a bead adapted to be snapped into the socket.

Alternatively the snap-fastening comprises means defming two adjacent lips and clip means adapted to be engaged with the lips with a snap action to secure the lips adjacent one another.

Conveniently the said clip means are provided with a line of mechanical weakness to facilitate the rupturing of the clip means.

Preferably the part of the housing defining the chamber defines a line of mechanical weakness adapted to rupture on inflation of an airbag contained with the housing.

Advantageously the housing may be provided in combination with an airbag contained within the chamber defined by the housing.

In order that the invention may be more readily understood, and so that various 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 part sectional view of one form of airbag housing in accordance with the invention, illustrating, schematically, an airbag within the housing, FIGURE 2 is a rear view of the housing shown in Figure 1, FIGURE 3 is an exploded view showing an alternative form of housing in accordance with the invention, without an airbag being present, and

FIGURE 4 is a further diagrammatic view of yet another embodiment of the invention.

Referring initially to Figure 1 of the accompanying drawings, a housing 1 is provided adapted to contain an airbag 2. The housing 1 is of elongate form and is produced from an extrusion of an appropriate plastics material.

The housing defines a substantially vertically positioned rear wall 3. The rear wall 3 has a lower part 4 and an upper part 5.

The lower part 4 of the rear wall 3 terminates, at its lower end, with a bifurcation which forms a socket 6. Received as a snap-fit within the socket 6 is a bead 7 carried on a wall portion 8. The wall portion 8 depends from a forwardly extending horizontal wall 9 which extends forwardly from the rear wall 3 at the junction between the lower part 4 of the rear wall 3 and the upper part 5 of the rear wall 3. The lower part 4 of the rear wall 3, the wall 8 and the horizontal wall 9 surround a hollow chamber 10. The hollow chamber 10 contains the airbag 2.

It is to be noted that the upper part 5 of the rear wall 3 is provided with a plurality of fixing apertures 11 to enable the housing to be fixed in position.

It is also to be observed that at least the upper region of the lower part 4 of the rear wall 3, and at least the region of the horizontal wall 9 that extends forwardly from the rear wall 3 are made substantially thicker, and thus stronger, than the remaining walls, as illustrated at 12.

Spaced evenly along the length of the housing I a plurality of cutouts 13 are provided. Each cut-out comprises a region where the material forming the upper part 5 of the rear wall 3, the horizontal wall 9, and a substantial proportion of both the wall 8 and the lower part 4 of the rear wall 3 have been removed. The only material remaining is the material forming part of the lower wall 8, and the lowest-most part of the rear wall 4, together with the socket 6 and the bead 7.

Referring to Figure 2, the rear wall 3 of the housing is provided, adjacent each of the apertures 11, with a slot 14 that communicates with the chamber 10 accommodating the airbag 2. A substantially triangular lug or tab 15, which defines an aperture 16, which is formed integrally with the air- bag 2 passes out through each slot 14. The aperture 16 in each lug or tab is aligned with the aperture 11 formed in the upper part 5 of the rear wall 3.

The combination of the socket 6 and the bead 7 form a snap-fastening which can be used to facilitate the insertion of the folded airbag into the chamber 10.

Initially the snap-fastening will be in the open condition, with the bead 7 separated from the socket 6. The airbag may then be easily located within the chamber 10. The bead 7 may then be urged into the socket 6, thus easily closing the chamber.

The housing, together with the airbag, may then be mounted in position in a motor vehicle. Bolts or other fastening means will be utilised, the bolts passing through the aligned apertures 11 and 16 to be connected to anchoring points provided in the motor vehicle.

If the housing 1 has to adopt a non-linear form, the housing may be bent so that it has an appropriate configuration. The presence of the cut-outs 13 facilitates this bending, and helps ensure that when the housing has been bent, the bead 7 does not tend to become dislodged from the socket 6. Thus the bead 7 is securely retained within the socket 6 over the entire length of the housing. This serves to facilitate an opening of the housing when the airbag is inflated.

Inflation of the airbag will cause one end of the bead 7 to become disengaged from the socket 6. Continuing inflation of the airbag will cause the bead 7 to gradually peel out of the socket 6 over the entire length of the housing. The airbag may thus inflate in a uniform manner. If the cut-outs interrupted the connection between the bead 7 and the socket 6, not only would it be more difficult to close the snap-fastening constituted by the bead 7 and the socket 6 over the entire length of the housing during fabrication and assembly of the housing-and-air-bag combination, but also, during inflation of the airbag, problems might well arise. During the initial stage of inflation an initial section of the bead 7 would be removed from the socket 6. However, when a gap in the bead and socket was encountered, the airbag would continue to inflate until sufficient pressure was present within the airbag to cause the next section of the bead-and-socket snap-fastening to begin to disengage. The pressure in the air- bag would then reduce. This would lead to a very undesirable inflation characteristic.

The relatively stiff parts 12 of the upper region of the lower part 4 of the rear wall 3, and at least that part of the horizontally extending wall 9 that is secured to the rear wall 3, form a substantially rigid support which will aid in supporting the airbag 2 in the desired position when the airbag 2 is inflated.

Figure 3 illustrates a modified embodiment of the invention in which a housing 21 is provided, a substantial proportion of the housing having the same effective configuration as the housing 1 illustrated in Figure 1. The housing 21 is provided with a rear wall 22 having a lower region 23 and an upper region 24. The lower region 23 carries a forwardly projection portion 25, which terminates in a depending lip 26. The lip 26 is located adjacent a corresponding depending lip 27 carried by an adjacent wall portion 28, the wall portion 28 effectively being carried by a forwardly extending horizontal upper wall 29 which extends forwardly from the rear wall 22 at the junction between the lower portion 23 and the upper portion 24 thereof. The lower portion 23 of the rear wall, the forwardly extending projection 25, the wall portion 28 and the horizontal wall 29 together define a chamber or cavity 30 adapted to contain an airbag. The airbag will have mounting tabs equivalent to those of the embodiment of Figures 1 to 2.

The upper portion 24 of the rear wall 22 has a fixing aperture 31 and a plurality of cut-outs 32, which correspond to the cut-outs 13, may be provided, spaced along the length of the housing.

Clip means 33 are provided which connect together the lips 26 and 27. The clip means 33 may comprise one elongate clip or, alternatively, may comprise a plurality of relatively short clips. The clip is of substantially annulus form, with a small cut-out 34. The clip may be mounted over the lips 26,27 with a snap action. Part of the annulus forming the clip 33 is substantially cut away to form a line of mechanical weakness 35. Thus, although the clip may be mounted on the lips 26,27 with a snap action, the clip may be ruptured by breaking the line of mechanical weakness.

It is to be appreciated that an airbag may be inserted in the chamber 30 defined by the housing 21 illustrated in Figure 3, and the clip means 33 may then be located in position with a snap action on the adjacent lips 26 and 27. The housing 21, together with the airbag, may then be mounted in position in a motor vehicle. The housing may adopt a non-linear condition, with any necessary bending of the housing 21 being facilitated by the presence of the cut-outs 32. On inflation of the airbag, pressure generated within the housing will tend to cause the clip means 33 to rupture along the line of mechanical weakness 35, thus permitting the airbag to emerge from the chamber 30 to become fully inflated.

The upper region of the lower part 23 of the rear wall 22, and the upper horizontal extending wall 29 are made of a material which is somewhat thicker, and therefore somewhat stronger than the material forming the rest of the housing 20, thus ensuring that these regions can provide adequate support for the airbag when the airbag is inflated.

Figure 4 illustrates a further embodiment of the invention. Referring to Figure 4, a housing 40 comprises a rear wall 41 having a lower region 42 and an upper region 43. The upper region 43 is provided with an aperture 44 to facilitate the mounting of the housing in position.

A wall portion 45 extends horizontally forwardly from the rear wall 41 at the junction between the lower portion 42 and the upper portion 43. The wall 45 terminates with a socket 46 which receives a bead 47, the bead 47 being formed on a further horizontally extending wall portion 48. The horizontally extending wall portion 48 terminates and carries a depending front wall 49. Extending between the lower part of the front wall 49 and the lower- most part of the rear wall 41 is a horizontal lower wall 50. The horizontal lower

wall 50 is provided with a substantially centrally positioned line of mechanical weakness 51. The lower part 42 of the rear wall, the horizontal wall 45 and 48, the front wall 49 and the lower wall 50 together surround a chamber 52 adapted to contain an airbag or the like. The housing may be provided with a plurality of cut-outs 53 which correspond with the cut-outs 13.

Initially the bead 47 will be separated from the socket 46 facilitating the insertion of an airbag into the chamber 52. The airbag will have mounting tabs equivalent to those of the embodiment of Figures 1 and 2. Following insertion of the airbag in the chamber 52, the bead 47 will be snap-fastened into the socket 46. Each individual length of bead 47 between adjacent cut-outs 53 will have to be snap-fastened into the corresponding socket 46.

The housing may then be positioned in a motor vehicle. If the housing has to adopt a non-linear condition, this will be facilitated by the presence of the cut-outs 53.

In the event that the airbag is inflated, the lower wall 50 of the chamber 52 will break along the line of mechanical weakness 51, thus enabling the airbag to emerge from the chamber 52 to be fully inflated.

In each of the embodiments described above, the basic housing may be formed as an extrusion of an appropriate plastics material.

In the present Specification "comprise" 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. A housing for an airbag, the housing being of elongate form and being of substantially uniform cross-section, parts of the housing defining a chamber adapted to receive an airbag, the said parts of the housing being interconnected by a snap-fastening joint, wherein the airbag is provided with a plurality of apertured lugs, the apertured lugs passing through slots communicating with the chamber, and being aligned with apertures defined by the housing to accept mounting means for mounting the combination in position.
2. A housing according to Claim 1 comprising an extending wall portion provided with apertures to facilitate the fixing of the housing in position.
3. A housing according to Claim 1 or Claim 2 wherein the housing is formed as an extrusion of an appropriate plastics material.
4. A housing according to any one of Claims 1 to 3 wherein the snapfastening joint comprises a socket and a bead adapted to be snapped into the socket.
5. A housing according to any one of Claims 1 to 3 wherein the snap- fastening comprises means defining two adjacent lips and clip means adapted to be engaged with the lips with a snap action to secure the lips adjacent one another.

<Desc/Clms Page number 12>
6. A housing according to Claim 5 wherein the said clip means are provided with a line of mechanical weakness to facilitate the rupturing of the clip means.
7. A housing according to any one of Claims 1 to 6 wherein the part of the housing defining the chamber defines a line of mechanical weakness adapted to rupture on inflation of an airbag contained with the housing.
8. A housing according to any one of the preceding Claims in combination with an airbag contained within the chamber defined by the housing.