WO2002040322A1

WO2002040322A1 - An air-bag arrangement

Info

Publication number: WO2002040322A1
Application number: PCT/SE2001/002408
Authority: WO
Inventors: Dick Eriksson
Original assignee: Autoliv Development Ab
Priority date: 2000-11-16
Filing date: 2001-11-02
Publication date: 2002-05-23
Also published as: GB2369091A; AU2002212905A1; GB0028000D0; GB2369091B

Abstract

An air-bag arrangement is provided to provide protection for an occupant of the vehicle. The arrangement includes an air-bag (4) associated with an inflator (5) which generates gas to inflate the air bag. The gas enters an elongate diffuser (8) provided with apertures (9) in the side wall thereof. A piston (10) is contained within the diffuser which moves when the inflator is activated. The piston (10) is connected to a wire (11) which passes round pulleys (12, 13) to pull up part of the air-bag (4). The air-bag may be mounted at the side of a motor vehicle.

Description

"AN AIR-BAG ARRANGEMENT"

THE PRESENT INVENTION relates to an air-bag arrangement, and more particularly relates to an air-bag arrangement intended to provide protection in a motor vehicle in the event that a side impact or roll-over accident should occur.

It has been proposed previously to provide air-bag arrangements in motor vehicles to provide protection for an occupant of the vehicle in the event that a roll-over or side impact accident should occur. Typically such air-bag arrangements incorporate an air-bag or other inflatable element which can be deployed to be located between the driver and the side of the vehicle. Some prior proposed arrangements have been mounted on the door of the motor vehicle, or have been mounted in a fixed part of the motor vehicle to extend across a window provided at the side of the motor vehicle.

Reference may be made to DE 190,547,494 A which shows a safety device to provide protection to the occupant of the vehicle in the form of a convertible or "Soft Top" car in the case of a side impact or roll-over situation. The safety-device includes an inflatable element, in the form of an elongate inflated tubular structure, and also includes a rigid vertical element in the form of a rod attached to one end of the inflatable element, and also mounted on a piston so as to moved vertically upwardly when the described arrangement is deployed. The rigid rod thus moves one end of the inflatable tubular element f om an initial stored position adjacent the lower edge of a window in a motor vehicle to an elevated position. The arrangement disclosed has various disadvantages including the disadvantage that the vertical rod is rigid and does not provide flexibility during the deployment of the air-bag, and also the arrangement takes up a lot of room. The rigid rod may apply an excessive tension to the fabric of the air-bag, and may cause the air-bag to burst.

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

According to this invention there is provided an air-bag arrangement to provide protection for an occupant of a vehicle, the air-bag arrangement including an air-bag and an inflator adapted to generate gas to inflate the air- bag, the arrangement further incorporating an element adapted to move in response to the generation of gas by the inflator to apply tension to an elongate flexible element to raise part of the inflatable element to an operative position.

Preferably the arrangement is mounted adjacent a window formed in the side of a motor vehicle.

Conveniently the elongate flexible element passes a guide or pulley adjacent the top of the window, the air-bag and inflator being mounted beneath the window. Advantageously the arrangement is mounted in position on a door of a motor vehicle.

Conveniently the elongate flexible element is a cable or wire.

Preferably the inflator incorporates a pyrotechnic charge adapted to be ignited in response to a signal from a sensor which detects a roll-over or side impact situation.

Conveniently the inflator is associated with a tubular diffuser, a side wall of the diffuser being provided with a plurality of apertures through which gas from the inflator may flow to the interior of the air-bag.

In some preferred embodiments of the invention a piston is provided within the tubular diffuser, the piston comprising the element adapted to move in response to the generation of gas, the piston being connected to the elongate flexible element.

Conveniently the piston is adapted to move along the tubular elements successively passing the apertures therein, on actuation of the inflator, so that gas may pass through each aperture after the piston has passed the aperture.

Advantageously the inflator comprises a pyrotechnic charge in a housing communicating with the tubular diffuser.

Alternatively the inflator comprises a pyrotechnic charge within the piston. In an alternative embodiment of the invention the element adapted to move in response to the generation of gas comprises a turbine.

Conveniently the turbine is adapted to rotate a boss, the elongate flexible element being partially wound around the boss.

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 diagrammatic side view of part of a door of a motor vehicle showing an air-bag arrangement in accordance with the invention, diagrammatically, prior to deployment thereof,

FIGURE 2 is a view corresponding to Figure 1 illustrating the deployment of the air-bag,

FIGURE 3 is a view of a gas generator and diffuser unit which may be utilised instead of the gas generator and diffuser unit of Figure 1, and

FIGURE 4 is a view corresponding to Figure 3 illustrating yet another gas generator and diffuser unit which may be used in embodiments of the invention.

Referring initially to Figure 1, part of a door 1 of a motor vehicle is illustrated, that part of the door incorporating a side window 2. Mounted on the door of the vehicle beneath the side window 2 is a gas generator and diffuser unit 3. The gas generator and diffuser unit 3 is associated with an air-bag 4 which, as shown in Figure 1, is initially in a folded state. The

The gas generator and diffuser unit 3 comprises a housing 5 containing a pyrotechnic gas generating charge which is connected by means of a filter 6 to a manifold 7 which communicates with one end of an elongate tubular diffuser 8. A plurality of evenly spaced circular apertures 9 are formed in the side wall of the diffuser 8. A piston 10 is mounted within the tubular diffuser 8, the piston being a slidable substantially gas-tight fit within the tubular diffuser 8. The piston 10 is initially located adjacent the said one end of the diffuser 8. An elongate flexible element in the form of a wire or cable 11 is connected to the piston 10, and passes sealingly through the manifold 7 to pass around the periphery of a lower pulley 12 which is mounted on the door adjacent the gas generator and diffuser unit 3. The wire or cable 11 then extends upwardly to pass round an upper guide in the form of a pulley 13 which is located adjacent the top of the window 2, the wire or cable then passing back down to be connected to part of the air-bag 4.

The air-bag 4 is intended to be deployed in response to a signal from a sensor which is responsive to a side impact or roll-over accident situation. On deployment of the air-bag the pyrotechnic charge within the housing 5 is actuated to generate gas which passes through the filter 6 and through the manifold 7 into the tubular diffuser 8. As the gas passes into the tubular diffuser 8 it moves the piston axially along the tubular diffuser, away from the manifold 7. As the piston moves along the diffuser tension is applied to the wire or cable 11, which serves to draw upwardly that part of the air-bag 4 connected to the end of the wire or cable 11. The initial step of the deployment of the air-bag may be the raising up of part of the air-bag before inflation of the air-bag actually commences. Thus the air-bag is not constrained and is free to inflate when gas is introduced to the interior of the air-bag. Also, as the piston 10 moves along the tubular diffuser 8, the piston will pass successively the apertures 9. As the piston passes the first aperture gas may enter the air-bag to commence inflation of the air-bag. A small amount of gas will enter the very small volume of space within the uninflated air-bag and will commence inflation of the air-bag without creating a sufficiently high pressure within the air-bag to damage the air-bag. As the piston passes each successive aperture gas may flow through that aperture. Thus gas from the pyrotechnic charge initially enters the air-bag, during a preliminary stage of its inflation, only through one aperture 9 and finally enters the air-bag, during a final stage of its inflation, through all of the apertures. The air-bag 4 thus inflates, as shown schematically in Figure 2, with a gradually increasing quantity of gas being injected into the air-bag and with an upward force being applied to part of the air-bag by the wire or cable 11.

It is to be understood that whilst the invention has been described, in Figures 1 and 2, with reference to an embodiment in which an air-bag is provided which is located, when deployed, adjacent a window in a door of a motor vehicle, in alternative embodiments of the invention the air-bag may be mounted in a position where, when it is deployed, it is located adjacent a window in a fixed part of a motor vehicle, or adjacent a side wall of a motor vehicle if no side window is provided.

In an alternative embodiment the piston may initially be located in a position part way along the diffuser so that at least one aperture communicating with the interior of the air-bag is open.

Figure 3 illustrates an alternative gas generator and diffuser unit which can be used in place of the unit 3 as shown in Figure 1. In the embodiment shown in Figure 3, the gas generator and diffuser unit 20 consists of an elongate tubular diffuser 21 having a plurality of evenly spaced circular apertures 22 formed in the side wall thereof, there being a piston 23 which is a slidable substantially gas-tight fit within the tubular diffuser. The piston 23 is constituted by a housing which contains a pyrotechnic gas generating charge. The piston 23 is connected to an elongate flexible element in the form of a wire or cable 24 which passes through a substantially gas-tight seal 25 provided at one end of the tubular diffuser 21. The lower pulley wheel 12, as described above with reference to Figures 1 to 2, is located adjacent the gas generator and diffuser unit 20.

The piston 23 is located initially adjacent the right-hand end of the tubular diffuser 21 as shown in Figure 3, adjacent the seal 25. In response to a signal from a sensor which detects a roll-over or accident situation, the gas generator within the piston 23 generates gas and ejects that gas from the right- hand end of the piston, that is to say the end of the piston which is initially abutting the seal 25. The piston 23 thus moves towards the left, as shown in Figure 3, applying tension to the elongate wire or cable 24, and as the piston 23 moves to the left it passes sequentially the apertures 22. As each aperture 22 is passed, gas from the piston 23 may pass through that aperture to assist in the inflation of the air-bag. It is to be appreciated, therefore, that the embodiment of Figure 3 operates in a manner which is very similar to that described above with reference to Figures 1 and 2.

Referring now to Figure 4 of the accompanying drawings, a further modified gas generator and diffuser unit 30 is illustrated. This unit 30 includes a housing 31 which contains a pyrotechnic charge adapted to generate gas. The housing 31 is connected by means of a filter unit 32 to a turbine 33. The turbine has a boss 34, adapted to rotate with the turbine, the boss 34 having wound around it an end portion of an elongate wire or cable 35 which corresponds to the wire or cable 11 of the embodiment shown in Figures 1 and 2. The gas turbine 33 has an outlet which communicates directly with a tubular diffuser 36 which has a plurality of evenly spaced circular apertures 37 formed in the side wall thereof.

In response to a signal from a sensor which detects a roll-over or side impact accident situation, the pyrotechnic charge within the housing 31 generates gas which passes through the filter 32 and into the turbine 33 causing the turbine to rotate. As the turbine 33 rotates, so the boss 34 rotates applying tension to and drawing in the elongate wire or cable 35. Gas from the turbine enters the tubular diffuser and flows through the apertures 37 into the inflating air-bag. It is to be appreciated that in the embodiment shown in Figure 4, the wire or cable 35 will pass round an upper pulley corresponding to the pulley 13 of Figures 1 and 2 and will engage part of the inflating air-bag.

In embodiments of the invention the air-bag may be divided into vertical chambers or cells, with the apertures in the diffuser communicating with respective cells, so that the cells commence inflation sequentially.

In the present specification "comprise" means "includes or consists of and "comprising" means "including or consisting of.

Claims

CLAIMS:

1. An air-bag arrangement to provide protection for an occupant of a vehicle, the air-bag arrangement including an air-bag and an inflator adapted to generate gas to inflate the air-bag, the arrangement further incorporating an element adapted to move in response to the generation of gas by the inflator to apply tension to an elongate flexible element to raise part of the inflatable element to an operative position.

2. An arrangement according to Claim 1 wherein the arrangement is mounted adjacent a window formed in the side of a motor vehicle.

3. An arrangement according to Claim 2 wherein the elongate flexible element passes a guide or pulley adjacent the top of the window, the air-bag and inflator being mounted beneath the window.

4. An arrangement according to Claim 2 or 3 wherein the arrangement is mounted in position on a door of a motor vehicle.

5. An arrangement according to any one of the preceding Claims wherein the elongate flexible element is a cable or wire.

6. An arrangement according to any one of the preceding Claims wherein the inflator incorporates a pyrotechnic charge adapted to be ignited in response to a signal from a sensor which detects a roll-over or side impact situation.

7. An arrangement according to any one of the preceding Claims wherein the inflator is associated with a tubular diffuser, a side wall of the diffuser being provided with a plurality of apertures through which gas from the inflator may flow to the interior of the air-bag.

8. An arrangement according to Claim 7 wherein a piston is provided mounted within the tubular diffuser, the piston comprising the element adapted to move in response to the generation of gas, the piston being connected to the elongate flexible element.

9. An arrangement according to Claim 8 wherein the piston is adapted to move along the tubular elements successively passing the apertures therein, on actuation of the inflator, so that gas may pass through each aperture after the piston has passed the aperture.

10. An arrangement according to Claim 8 or 9 wherein the inflator comprises a pyrotechnic charge in a housing communicating with the tubular diffuser.

11. An arrangement according to Claim 8 or 9 wherein the inflator comprises a pyrotechnic charge within the piston.

12. An arrangement according to any one of Claims 1 to 7 wherein the element adapted to move in response to the generation of gas comprises a turbine.

13. An arrangement according to Claim 12 wherein the turbine is adapted to rotate a boss, the elongate flexible element being partially wound around the boss.