GB2353977A

GB2353977A - An air-bag arrangement

Info

Publication number: GB2353977A
Application number: GB9921241A
Authority: GB
Inventors: Sture Andersson; Dick Eriksson
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1999-09-08
Filing date: 1999-09-08
Publication date: 2001-03-14
Anticipated expiration: 2019-09-08
Also published as: GB9921241D0; GB2353977B

Abstract

An air-bag arrangement provides protection for a driver or occupant of a motor vehicle. A sensor (1) responds to an impact of the motor vehicle to initiate operation of a gas generator (2). Gas from the gas generator passes to a gas duct (4) and leads to an inflatable element (5). The inflatable element is initially retained in a recess or housing (6) in the roof of the vehicle. When gas flows into the gas duct (4) the gas duct becomes substantially rigid to locate at least part of the inflatable element (5) from said recess or housing (6) to a predetermined position.

Description

1 1 2353977 i DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO AN

AIR-BAG ARRANGEMENT" THE PRESENT INVENTION relates to an air-bag arrangement, and in particular relates to an air-bag arrangement for use in a motor vehicle, such as a motor car, to provide protection for the driver or an occupant of the vehicle in the event that an accident should arise.

It has been proposed previously to provide an air-bag arrangement in a motor vehicle in which an air-bag is mounted in the roof of the vehicle and is adapted, when deployed, to occupy a position in which at least part of the airbag is located in front of the occupant of the vehicle to be protected.

US A 3795412 discloses an air-bag arrangement in which a plurality of inflatable tubes are provided which are initially stored in the roof of a vehicle, above the driver. The tubes are associated with netting that interconnects the tubes. In the event that an accident arises the tubes are inflated and extend downwardly from the roof of the car forming a cage that surrounds the occupant of the car and also the back of the seat in which the occupant of the vehicle is sitting. Thus the head and torso of the occupant are prevented from moving forwardly or laterally relative to the back of the seat. It is thought that I I 2 if this system were to be used, in an accident situation the head of the occupant, which typically moves forwardly relative to the torso - since the torso is usually restrained by a seat belt - will engage the combination of the inflatable tubes and the netting and will be bent rearwardly relative to the torso, which may lead to undesirable injuries. At the conclusion of the accident, the occupant will still be encased by the netting, even if the inflatable tubes deflate, and thus may have great problems in leaving the vehicle. This is undesirable since in many cases it is desirable for the occupants of a vehicle to leave the vehicle as soon as possible after an accident has occurred. A further problem with this arrangement is that if the occupant of the vehicle is leaning forwardly at the instant that the air-bag arrangement is deployed, they may be held in the forward position, instead of in the upright position, which may lead to an increase in the injuries sustained, rather than a decrease.

US-A-3774936 discloses an arrangement in which an air-bag is mounted in the roof of a vehicle in a housing that extends transversely of the rear seat. The air-bag, when deployed, is located in front of an occupant of the vehicle seat. The air-bag is associated with wires on each side of the vehicle. Each wire is an endless loop which is connected to anchoring points in the roof and behind the shoulder of the occupant of the seat, there being a loop of fabric on the air-bag that surrounds the wire of the endless wire loop. The arrangement guides the inflating air-bag so that, when inflated, the air-bag applies a downward and rearward force on the pelvic area of the occupant of the seat, as well as providing a physical barrier in front of the seat occupant to restrain forward movement. In use of an arrangement of this type there is again a risk that the head of the occupant will engage the inflated bag before the torso, and thus the head will be bent back in an undesirable manner relative to the torso.

3 US-A 4536008 also discloses an air-bag arrangement in which an airbag is mounted on the roof of a motor vehicle to be deployed to occupy a position in front of an occupant of the vehicle in the event that an accident occurs. The air-bag is designed so that the lower end of the air- bag engages and applies a downward force to the lap of the occupant of the vehicle to retain the occupant of the vehicle in the desired position, whilst also forming a barrier in front of the occupant. The upper part of the air-bag is mounted to the roof of the vehicle in such a way that the upper part of the air-bag can move forwardly, from its initial position, by up to a predetermined distance if the occupant of the vehicle applies a substantial force to the inflated air-bag. The upper part of the air-bag moves against a bias provided by springs. Again it is thought that if the head of the occupant makes contact with the air-bag after is has been deployed, even though the top part of the air-bag can move forwardly slightly, nevertheless, there is still a severe risk that the neck of the occupant will be bent back as the torso continues to move forwardly while the head is restrained.

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

According to one aspect of this invention there is provided an air-bag arrangement to provide protection for a driver or occupant of a motor vehicle, the air-bag arrangement comprising a sensor responsive to an impact of the motor vehicle, a gas generator adapted to be actuated in response to a signal from the sensor, and a gas duct provided to receive gas from the gas generator and to lead gas to an inflatable element, the inflatable element initially being retained in a recess or housing, the arrangement being such that on actuation of the gas generator the gas duct becomes substantially rigid to locate at least part of the inflatable element from said recess or housing at a predetermined position.

4 Preferably the gas flow path through the gas duct to the inflatable element includes a constriction adapted to constrict the flow of gas.

Conveniently the inflatable element is adapted, on inflation, to move to a position in which it is totally separated from the recess or housing in which it is initially stored.

Preferably the gas duct incorporates an extension extending transversely to a main part of the duct, the extension extending across at least part of the inflatable element.

Conveniently the extension of the gas duct is connected to the inflatable element by means permitting a restricted flow of gas.

In one embodiment two gas ducts are provided, with one gas duct being provided on each side of the motor vehicle, the gas ducts each cominunication with a single inflatable element.

Conveniently each gas duct is associated with a respective gas generator.

Preferably said recess or housing extends transversely of the axis of the vehicle and is in the roof of the vehicle.

Conveniently said recess or housing is located above and in front of the position to be occupied by a driver or passenger in the vehicle.

Advantageously the inflatable element, when inflated is located in front of a driver or passenger in the vehicle.

The invention also relates to a method of deploying an air-bag arrangement, which air-bag arrangement includes a gas duct and an inflatable element, the method comprising the steps of initially inflating a gas duct so that the gas duct becomes substantially rigid, inflation of the gas duct locating at least part of the inflatable element in a predetermined position, and inflating the inflatable element with gas flowing through the gas duct.

Preferably in inflating the inflatable element, or extension of the gas duct is inflated, and subsequently gas is passed from the extension of the gas duct of the inflatable element, the inflatable element then inflating.

Conveniently the first part of the inflatable element extends substantially transversely to the axis of the gas duct.

Preferably gas is supplied to the inflatable element through two substantially parallel gas ducts, the gas ducts being spaced apart.

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 I is a diagrammatic view of an air-bag arrangement in accordance with the invention illustrating the air-bag during a preliminary stage in inflation of the air-bag, FIGURE 2 is a view corresponding to Figure I illustrating the air-bag of Figure I at a subsequent stage during inflation of the air-bag, 6 FIGURE 3 is a view illustrating an alternative embodiment of the invention, and FIGURE 4 is a diagrammatic part sectional view illustrating a modified embodiment of the invention.

Referring initially to Figure I of the accompanying drawings, an air-bag arrangement is illustrated. The air-bag arrangement is adapted to provide protection for a driver or front-seat passenger (i.e. a front seat occupant) in a motor vehicle in the event that an accident should occur. The air-bag arrangement comprises a sensor I adapted to sense a frontal impact of the motor vehicle, the sensor I being adapted to actuate a gas generator 2. The sensor and gas generator may be mounted in the roof line of the motor vehicle at a position above the rear door of the motor vehicle, that is to say to the rear of the B-Post 3 of the motor vehicle.

The gas generator 2 is connected by means of a gas duct 4 to an inflatable element or air-bag 5. The inflatable element 5 is initially stored in a recess or housing, schematically illustrated as recess 6 which extends transversely of the motor vehicle in the roof of the motor vehicle at a position above and just in front of a front-seat occupant of a motor vehicle.

The inflatable element 5, as illustrated, may be dimensioned to extend across half of the width of the motor vehicle.

Initially the inflatable element 5 will be contained within the recess 6 which may be invisible to the ordinary occupant of the motor vehicle, and a gas duct 4 will also be stored appropriately in a concealed manner.

7 The gas duct may be formed of a fabric, such as the fabric used to form the inflatable element 5.

The gas duct 4 may be connected to the inflatable element 5 by means of a constriction 7 which will restrict or impede the flow of gas through the gas duct. The constriction 7 will be dimensioned so that during the initial stage of inflation of the inflatable element, which will be described hereinafter, the gas duct 4 becomes rigid. When rigid, the gas duct extends substantially parallel to the axis of the vehicle, extending forwardly of the gas generator 2.

The gas duct 4 may be connected to supply gas to an extension 8 of the gas duct. The extension 8 of the gas duct extends transversely to the main part of the gas duct. The extension 8 is mounted on the exterior of the inflatable element 5, extending across the lower part of the inflatable element, thus extending transversely across the vehicle. The extension 8 does not cover the upper part 9 of the inflatable element 5. A perforated panel 10 (see Figure 2) separates the extension 8 of the gas duct and the inflatable element 5. Perforated panel 10 thus permits a restricted flow of gas from the extension 8 into the inflatable element 5. The arrangement is such that gas flowing through the constriction 7 will initially inflate, or substantially inflate, the extension 8 before gas passes through the peiforated panel 10 to inflate the inflatable element 5. The inflatable element 5 is illustrated as having a generally rectangular configuration, but may have an altemative configuration.

In the event that the sensor I senses an impact of the motor vehicle, the gas generator 2 is activated, and gas is fed from the gas generator 2 to the gas duct 4. Because of the presence of the constriction 7, the gas duct 4 will initially inflate and become rigid. As the gas duct 4 inflates and becomes rigid, it occupies the position illustrated in Figure I and 2, extending forwardly and 8 downwardly from the gas generator relative to the axis of the vehicle. Consequently the gas duct4 may assist in withdrawing at least part of the inflatable element from the recess 6 and will guide or position at least that part of the inflatable element in front of the driver of the motor vehicle. Thus the gas duct 4 locates at least part of the inflatable element 5 in a predetermined position. The inflatable element may be driven out of the recess, however, as a consequence of the inflation of the inflatable element passes through the constriction 7 and inflates the extension 8 of the gas duct. The extension 8 extends transversely to the axis of the main part of the gas duct 4 extends in a generally forward direction from the gas generator 2 relative to the axis of the vehicle. Extension 8 of the gas duct thus extends transversely relative to the axis of the vehicle. Subsequently gas flows from the inflated extension 8 of the gas duct through the perforated panel 10 to inflate the inflatable element 5. The inflatable element is thus fully inflated and is held in place by the rigid inflated gas duct 4.

Figure 3 illustrates a modified embodiment of the invention in which there are two gas generators 2, each associated with a respective gas supply duct 4 shown in Figure 1. The two gas supply ducts 4 are spaced apart relative to the axis of the vehicle, and are each connected, by means of a respective constriction 7, to a single extension 8 which extends across the lower part of the inflatable element 5.

Figure 4 illustrates a modified embodiment of the invention. In this embodiment of the invention the main part 4 of the gas duct is joined to a transverse extension 8 of the gas duct without any constriction. The transverse extension 8 of the gas duct effectively forms the lower part of the inflatable element 5. A perforated panel 10 is provided which communicates between the gas duct 8 and a main part I I of the inflatable element 5.

9 Instead of perforated panel 10, as illustrated, the extension 8 of the gas duct 9 may be formed integrally with the rest of the inflatable element 5, and may be separated from the main part I I of the inflatable element by means of a seam, the seam comprising a plurality of slightly spaced-apart seam portions which permit a restricted flow of gas from the extension 8 of the gas duct into the main part I I of the inflatable element.

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.

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Claims

CLAIMS:

1. An air-bag arrangement to provide protection for a driver or occupant of a motor vehicle, the air-bag arrangement comprising a sensor responsive to an impact of the motor vehicle, a gas generator adapted to be actuated in response to a signal from the sensor, and a gas duct provided to receive gas from the gas generator and to lead gas to an inflatable element, the inflatable element initially being retained in a recess or housing, the arrangement being such that on actuation of the gas generator the gas duct becomes substantially rigid to locate at least part of the inflatable element from said recess or housing to a predetermined position.

2. An arrangement according to Claim I wherein the gas flow path through the gas duct to the inflatable element including a constriction adapted to constrict the flow of gas.

3. An arrangement according to any one of the preceding Claims wherein the inflatable element is adapted, on inflation, to move to a position in which it is totally separated from the recess or housing in which it is initially stored.

4. An air-bag arrangement according to any one of Clams I to 3 wherein the gas duct incorporates an extension extending transversely to a main part of the duct, the extension extendincy across at least pail of the inflatable element.

Z'

5. An air-bag arTangement according to Claim

6 wherein the extension of the gas duct is connected to the inflatable element by means permitting a restricted flow of gas.

11 6. An arrangement according to any one of the preceding Claims wherein two gas ducts are provided, spaced transversely relative to the vehicle, the gas ducts each communicating with a single inflatable element.

7. An arrangement according to Claim 6 wherein each gas duct is associated with a respective gas generator.

8. An arrangement according to any one of the preceding Claims wherein said recess or housing extends transversely of the axis of the vehicle and is in the roof of the vehicle.

9. An arrangement according to Claim 8 wherein said recess or housing is located above and in front of the position to be occupied by a driver or passenger in the vehicle.

10. An arrangement according to any one of the preceding Claims wherein the inflatable element, when inflated, is located in front of a driver or passenger in the vehicle.

11. A method of deploying an air-bag arrangement, which air-bag arrangement includes a gas duct and an inflatable element, the method comprising the steps of initially inflating a gas duct so that the gas duct becomes substantially rigid, inflation of the gas duct locating at least part of the inflatable element in a predetermined position, and inflating the inflatable element with gas flowing through the gas duct.

12. A method according to Claim I I wherein, in inflating the inflatable element, or extension of the gas duct is inflated, and subsequently gas is passed 12 from the extension of the gas duct of the inflatable element, the inflatable element then inflating.

13. A method according to Claim 12 wherein the first part of the inflatable element extends substantially transversely to the axis of the gas duct.

14. A method according to any one of Claims I I to 13 wherein gas is supplied to the inflatable element through two substantially parallel gas ducts, the gas ducts being spaced apart.

15. An air-bag arrangement substantially as herein described with reference to and as shown in Figures I and 2 of the accompanying drawings.

16. An air-bag arrangement substantially as herein described with reference to and as shown in Figures 3 and 4 of the accompanying drawings.

17. A method of deploying an air-bag arrangement substantially as herein described.

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