GB2272189A

GB2272189A - Air bag inflator mounting with flange seal

Info

Publication number: GB2272189A
Application number: GB9321429A
Authority: GB
Inventors: Takayasu Zushi; Motonobu Kitagawa; Kazuhiko Yamakawa; Masato Kuretake; Yoshimi Yoshida; Sawayo Uda
Original assignee: Takata Corp
Current assignee: Takata Corp
Priority date: 1992-10-30
Filing date: 1993-10-18
Publication date: 1994-05-11
Also published as: DE4335831A1; JPH06144145A; GB9321429D0

Abstract

A retainer 10' carrying an air bag 16' on its front surface has an opening 12' in which an inflator 14' is mounted. The inflator has a flange 48 projecting from its outer periphery and has a front surface held on the rear surface of the bag retainer around its opening. A resin annular member 50 surrounds the inflator, and contacts its outer periphery, the front surface of its flange and the retainer at its inside edge (bead type seal), or the front surface of the flange and the rear surface of the retainer (fig.2 - gasket type seal) to form a seal against leakage of inflator gas. <IMAGE>

Description

2272189

TITLE OF THE INVENTION

STRUCTURE FOR MOUNTING AN INFLATOR IN AN AIR BAG DEVICE FIELD OF THE INVENTION

This invention relates to mounting structure of an inflator to a bag retainer in an air bag device which extends upon collision of a vehicle to protect its occupant. DESCRIPTION OF THE RELATED ART:

An air bag device which is installed in front of a seat in an automobile is intended for protecting its occupant in cases of emergency, such as the collision of the vehicle, by causing an air bag to extend rapidly by the pressure of gas released from a gas generator called an inflator.

Fig. 3 is a sectional view showing by way of an example of a conventional air bag device for a driver of a vehicle, Fig. 4 is an enlarged view of part A of Fig. 3, and Fig. 5 is an exploded perspective view showing mounting structure of an inflator.

A member 10 for holding an air bag, which is called a retainer, has a central opening (inflator mounting hole) 12 in which the inflator 14 is fitted. An air bag 16 has an opening 18 through which the inflator 14 partly projects into the air bag 16. A peripheral portion of the opening 18 lies along the edge portion of the mounting hole 12. The edge portion of the air bag 16 surrounding the opening 18 is held by a holding ring 20 against the edge portion of the mounting hole 12. Fig. 5 also shows a reinforcing fabric 17.

The air bag 16 is kept extensibly in an folded form, and is covered by a modular cover 22. The modular cover 22 is torn by the inflating pressure of the air bag 16 when the air bag 16 is extended by the gas released from the inflator 14.

Stud bolts 38 are secured to the holding ring 20, extend through bolt holes 40 in the air bag 16, bolt holes 42 in the retainer 10 and bolt holes 44 in a flange 48 projecting from the outer peripheral surface of the inflator 14, and are tightened by nuts 46 to fasten the air bag 16 and the inflator 14 to the retainer 10, as shown in Fig. 5.

The conventional air bag device in which the flange 48 of the inflator 14 is held against the back of the retainer 10 around its opening 12 as hereinabove described is, however, likely to have an inflator-gas leak out through the mating surfaces of the flange 48 and the retainer 10. An O-ring is interposed between the flange 48 and the retainer 10 to prevent the leakage of gas. However, the O-ring slipps easily when the inflator is installed with the retainer 10, so that a lot of labor or working effort is consumed in mounting of the inflator 14 and its inspection.

A, OBJECT AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide structure for mounting an inflator in an air bag device which prevents gas leakage from peripheral space around the inflator.

It is another object of the present invention to provide a structure for mounting an inflator in an air bag device which facilitates mounting an inflator to a retainer and its inspection.

In the present invention, a bag retainer carrying an air bag on its front surface has an opening in which an inflator is so fitted as to project into the air bag. The inflator has a flange projecting from its outer periphery. A front surface of the flange is in contact with the rear surface of the retainer around its opening.

According to a first aspect of the invention, the device includes an annular member of a resin surrounding the inflator. The resin is bonded to a corner of outer periphery of the inflator and the front surface of the flange. The resin is in contact with the retainer at periphery of the opening.

According to a second aspect of the invention, the device includes an annular member of a resin surrounding the inflator and being bonded to the front surface of the flange. The resin is in contact with the rear surface of the bag retainer.

In either event, the annular member of the resin adheres to the flange of the inflator. Therefore, the resin does not displace itself in any way when the inflator is mounted. The resin forms an effective and reliable seal against any leakage of an inflator gas between the flange of the inflator and the bag retainer. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a fragmentary elevational view, partly in section, of a device embodying this invention; Fig. 2 is a view similar to Fig. 1, but showing another embodiment of this invention; Fig. 3 is an elevational view, partly in section, of a conventional air bag device; Fig. 4 is an enlarged view of part A of Fig. 3; and Fig. 5 is an exploded perspective view of the conventional device. DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described with reference to Figs. 1 and 2 showing devices embodying it. Figs. 1 and 2 are both similar to Fig. 4, and the reference numerals used in Fig. 4 are each followed by a prime, or dash in Figs. 1 and 2, so that no repeated description of the common parts may be necessary.

- 4 J Z 4 The device shown in Fig. 1 includes an annular member 50 of a resin surrounding an inflator 141, and contacting its outer periphery, the front (or upper in FIGURE 1) surface of its flange 48' and a bag retainer 10' at its edge defining an opening 121. The resin 50 forms an effective and reliable seal against any leakage of an inflator gas between the bag retainer 101 and the flange 481 of the inflator 1V. As the resin 50 adheres to the inflator 141, and does not displace itself, the inflator 141 is.easy to mount on the bag retainer 101.

The device shown in Fig. 2 includes an annular member 52 of a resin surrounding an inflator 141, and contacting the front (or upper in Fig. 2) surface of its flange 48' and the rear (or lower) surface of a bag retainer 10'. The resin 52 forms an effective and reliable seal against any leakage of an inflator gas between the bag retainer 101 and the flange 48' of the inflator 1V. As the resin 52 adheres to the inflator flange 48' and does not displace itself, the inflator 14' is easy to mount on the bag retainer 101.

The annular member 50 or 52 of a resin is preferably of a hot-melt type resin, though it may also be formed from a cold-setting one. The amount of the resin to be employed for forming the annular member, or its thickness depends mainly upon the specific arrangement and dimensions of the bag retainer and the inflator.

Although the devices embodying this invention as hereinabove described are intended for protecting the driver of a vehicle, this invention is equally applicable to an air bag device for protecting a passenger.

As is obvious from the foregoing, the device of this invention enables the formation of an effective and reliable seal against any leakage of an inflator gas between the bag retainer and the flange of the inflator. Moreover, it greatly facilitates and accelerates the work of mounting the inflator and its inspection.

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Claims

WHAT IS CLAIMED IS:

1. An air bag device in which a bag retainer carrying an air bag on its front surface has an opening in which an inflator is so fitted as to project into said bag, while said inflator has a flange projecting from its outer periphery and having a front surface held on the rear surface of said retainer around said opening, wherein an annular member of a resin surrounding said inflator, and contacting said periphery thereof, said front surface of said flange and said retainer at its edge defining said opening is provided.

2. A device as set forth in claim 1, wherein said resin is a hot-melt type resin.

3. A device as set forth in claim 1, wherein said resin is a cold-setting resin.

4. An air bag device in which a bag retainer carrying an air bag on its front surface has an opening in which an inflator is so fitted as to project into said bag, while said inflator has a flange projecting from its outer periphery and having a front surface held on the rear surface of said retainer around said opening, wherein an annular member of a resin surronding said inflator, and contacting said front surface of said flange and said rear surface of said retainer is provided.

5. A device as set forth in claim 4, wherein said resin is a hot-melt type resin.

6. A device as set forth in claim 4, wherein said resin is a cold-setting resin.

7. An air bag device substantially as hereinbefore described with reference to the accompanying description and Figure 1 or Figure 2 of the drawings.

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