GB2390340A

GB2390340A - An air-bag having a gas-supply duct

Info

Publication number: GB2390340A
Application number: GB0215388A
Authority: GB
Inventors: Mats Berntsson; Hakan Jaconelli; Fredrik Kjell; Jack Johanssen
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
Also published as: GB0215388D0

Abstract

An air-bag 1 comprises an inflatable region 2 defining an internal passage 12 accommodating a gas-supply duct 8 which is configured to be connected at one end to a gas generator. The gas-supply duct 8 has a number of apertures 11 through which gas may flow to inflate the inflatable region 2 . A terminal part 10 of the gas-supply duct 8 located remote from the gas generator is configured to engage part of the inflatable region 2 when gas flows through the gas-supply duct 8 to prevent substantial movement of the terminal part 10 of the gas-supply duct 8 relative to the inflatable region 2 . Preferably the air-bag 1 is an inflatable curtain having the inflatable region 2 divided into a plurality of chambers 4. Fixing straps 5, 6 may be provided at opposite ends of the inflatable region 2 and a plurality of mounting lugs 7 may be provided at an upper-most edge of the inflatable region 2.

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 of the type which incorporates an internal filling tube.

It has been proposed to provide various types of air-bags which incorporate an internal filling tube. One type of air-bag which incorporates an internal filling tube is an air-bag which is in the form of an inflatable curtain which, when inflated, is located adjacent the side windows of a motor vehicle.

Typically such an air-bag is provided with a generally rectangular inflatable region, the upper edge of which is provided with mounting lugs by means of which the air-bag may be mounted in position. The inflatable region is defined into a plurality of separate inflatable chambers, and an internal fabric duct is provided to direct gas from the gas generator to the chambers that are to be inflated. One air-bag of the above- mentioned type is shown in US-B-6,199,898.

The disclosed air-bag includes an internal fabric gas-supply duct which is formed from a folded strip of fabric, the strip of fabric being folded so that opposed edges thereof are superimposed, the superimposed edges being

incorporated in a seam between two layers of fabric which form the airbag.

The gas-supply duct is held in position, but, due to the stitching, there is a risk of gas being lost from the air-bag due to leakage.

In other prior proposed arrangements, an internal fabric gas-supply duct has been provided, one end of the gas duct being securely connected to part of the gas generator, and the other end of the duct being stitched to the air-bag to prevent movement of the duct, relative to the air-bag, on inflation of the air-

bag. Again there is a risk that gas may be lost due to the stitching of the duct to the air-bag.

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

According to the present invention, there is provided an air-bag, the air-

bag comprising an inflatable region; the inflatable region defining an internal passage; the internal passage accommodating a gas supply duct, one end of which is configured to be connected to a gas generator; the gas supply duct being provided with apertures through which gas may flow to inflate the inflatable region; a terminal part of the gas supply duct remote from said one end, being configured to engage part of said inflatable region, when gas flows through the gas supply duct, to prevent substantial movement of the terminal part of the gas supply duct relative to the inflatable element.

Preferably, the air-bag is an inflatable curtain, the air-bag having an inflatable region divided into a plurality of chambers, the gas-supply duct extending through the internal passage to direct gas into the chambers.

Advantageously, the terminal part of the gas-supply duct is configured to extend into part of at least one said chamber when gas flows through the gas-

supply duct.

Conveniently, the terminal part of the gas-supply duct is configured to extend into a plurality of said chambers when gas flows through the gassupply duct. Preferably, the terminal part of the gas-supply duct is provided with specifically configured regions to extend into the chamber or chambers.

Advantageously, the terminal part of the gas-supply duct has a diameter greater than the diameter of the passage so that parts of the gas-supply duct distend into the chamber or chambers.

Conveniently, a terminal part of the internal passage is constituted by an extension in the form of a pocket, the pocket having an increasing diameter; the terminal part of the gas-supply duct being received within the pocket and also being of increasing diameter.

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 side view of a first embodiment of the invention,

FIGURE 2 is a diagrammatic side view of a second embodiment of the invention, FIGURE 3 is a diagrammatic side view of a third embodiment of the invention, and FIGURE 4 is a diagrammatic side view of a fourth embodiment of the invention. Each of the embodiments of the invention that will be described is in the form of an inflatable curtain. However, the invention may be applied to other types of air-bags.

Referring initially to Figure 1, an air-bag 1 in accordance with the invention is illustrated in the form of an inflatable curtain. The airbag has a main substantially rectangular inflatable region 2, defined by two superimposed layers of fabric which were interconnected by seams 3 which define a plurality of inflatable chambers 4. The inflatable chambers 4 are, in the illustrated embodiment, generally rectangular. A first fixing strap 5 is provided at one end of the rectangular inflatable region 2, and a second fixing strap 6 is provided at the other end of the rectangular inflatable region 2. The upper-most edge of the rectangular inflatable region 2 is provided with a plurality of mounting lugs 7.

An internal gas-supply duct 8 is provided, one end 9 of which is configured to be connected to a gas generator (not shown). The gas supply duct 8 extends through an internal passage 12 defined within the rectangular inflatable region 2, the internal passage 12 extending across the top of the rectangular inflatable region 2 beneath the mounting lugs 7. The passage 12 has such diameter that it can accommodate the gas supply duct 8 when gas is flowing through the gas supply duct 8 from the generator. The passage 12 is effectively defined

between the upper-most edge of the rectangular inflatable region 2, and the upper parts of the seams 3 which define the chambers 4.

As thus far described, the inflatable curtain is of conventional design.

In the inflatable curtain of Figure 1, the other end of the gas-supply duct 8, that is to say the end remote from the first end 9 which is configured to be connected to the gas generator, is configured so that on inflation thereof the terminal part of the gas supply duct will have a dimension greater than the diameter of the internal passage 12, that terminal part being located at such a position within the inflatable region 2 that the terminal part may expand to occupy a space that does not form part of the internal passage 12.

Thus, as shown in the embodiment of Figure 1, the very end part IO of the gas supply duct 8 is configured so that, when gas flows through the gas supply duct 8 from the gas generator, the end part 10 will extend downwardly into the terminal chamber 4a located remote from the gas generator. The end part 10 has gas outlet apertures 11 to supply gas to the terminal chamber 4a, whilst the gas-supply duct 8 also has similar apertures 11 provided along its length to supply gas to the other chamber 4. The end part 10 is specifically pre-

configured to have the described shape when gas flows through the gas supply duct 8.

Because the end part 10 extends downwardly into the terminal chamber 4a, the end part 10 of the gas supply duct 8 is effectively securely blocked in position. It will thus be understood that both ends of the gas-supply duct 8 are firmly held in position, and consequently the various apertures l l of the gas supply duct 8 will be held in an appropriate position relative to the chambers 4 to be inflated.

Figure 2 illustrates a second embodiment of the invention which is similar to that of Figure 1 except that at the end of the gas supply duct 8 remote from the first end 9 which is to be connected to the gas generator, the gas-

supply duct 8 has a length made to be of a greater diameter than the diameter of the passage 12 provided within the rectangular inflatable region 2 to accommodate the gas-supply duct 8. Consequently, when gas flows through the gas-supply duct 8, three adjacent portions 13, 14, 15 ofthe end region ofthe gas-supply duct 8 each distend downwardly into a respective chamber 4, thus again locking the terminal part of the gassupply duct securely in position within the rectangular inflatable region 2, to prevent axial displacement of the gas-supply duct within the passage 12.

Figure 3 illustrates yet another modified embodiment of the invention in which the end region of the gas flow duct 8 remote from the first end 9 to be connected to the gas generator is provided with three regions 16, 17, 18, each configured to extend into a respective chamber 4 when gas flows through the gas-supply duct 8. In the embodiment of Figure 3 it is not simply that the diameter of the gas-supply duct 8 is greater than the diameter of the passage 12, but instead, the end region of the gas-supply duct is provided with specific pre-

defined regions configured to extend downwardly into the three terminal chambers 4 of the inflatable region 2.

Figure 4 illustrates a further embodiment of the invention. In this embodiment of the invention the internal passage 12 is provided with a terminal pocket 20 of frusto conical form at a position remote from the position at which the gas-supply duct connects with the gas generator. The pocket 20 thus has a relatively narrow neck 21 provided at the end of the passage 12, which leads to a relatively broad base 22. The terminal end of the gas-supply duct 8 is

provided with an extension 23 received within the pocket 20, the extension 23 being of gradually increasing diameter, away from the linear part of the duct.

Thus, when gas flows through the gas-supply duct 8, the terminal extension 23 will become inflated, such that the end part of the extension 23 adjacent the broad base 22 of the pocket 20, has a greater diameter than that of the neck 21 connecting the pocket 20 to the end of the passage 12. As will be appreciated, the inflated extension 23 thereby prevents the terminal part of the gas-supply duct 8 from being withdrawn from the pocket 20.

In each of the embodiments described above it will be appreciated that when gas flows through the gas-supply duct 8 from the gas generator, the gas-

supply duct 8 distends so that part of the gas-supply duct 8 engages part of the inflatable region 2 that is defining the passage 12, to prevent movement of the terminal part of the gas-supply duct 8 relative to the rest of the inflatable region 2.

Whilst the invention has been described with reference to preferred embodiments, it is to be appreciated that many different embodiments may be devised without departing from the scope of the invention. For example, the number of inflatable chambers and the configuration of the inflatable chambers may be changed substantially according to the specific design of the motor vehicle in which the inflatable curtain is to be mounted.

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 comprising an inflatable region; the inflatable region defining an internal passage, the internal passage accommodating a gas supply duct, one end of which is configured to be connected to a gas generator; the gas supply duct being provided with apertures through which gas may flow to inflate the inflatable region; a terminal part of the gas supply duct remote from said one end, being configured to engage part of said inflatable region, when gas flows through the gas supply duct, to prevent substantial movement of the terminal part of the gas supply duct relative to the inflatable element.

2. An air-bag according to Claim 1 wherein the air-bag is an inflatable curtain, the air-bag having an inflatable region divided into a plurality of chambers, the gas-supply duct extending through the internal passage to direct gas into the chambers.

3. An air-bag according to Claim 2 wherein the terminal part of the gas-

supply duct is configured to extend into part of at least one said chamber when gas flows through the gas-supply duct.

4. An air-bag according to Claim 2 wherein the terminal part of the gas-

supply duct is configured to extend into a plurality of said chambers when gas flows through the gas-supply duct.

5. An air-bag according to Claim 3 or 4 wherein the terminal part of the gas-supply duct is provided with specifically configured regions to extend into the chamber or chambers.

6. An air-bag according to Claim 3 or 4 wherein the terminal part of the gas-supply duct has a diameter greater than the diameter of the passage so that parts of the gas-supply duct distend into the chamber or chambers.

7. An air-bag according to Claim 1 or Claim 2 wherein a terminal part of the internal passage is constituted by an extension in the form of a pocket, the pocket having an increasing diameter; the terminal part of the gas-supply duct being received within the pocket and also being of increasing diameter.

8. An air-bag substantially as herein described with reference to and as shown in Figure 1 of the accompanying drawings.

9. An air-bag substantially as herein described with reference to and as shown in Figure 2 of the accompanying drawings.

10. An air-bag substantially as herein described with reference to and as shown in Figure 3 of the accompanying drawings.

11. An air-bag substantially as herein described with reference to and as shown in Figure 4 of the accompanying drawings.

12. Any novel feature or combination of features disclosed herein.