GB2333071A

GB2333071A - Elongate side impact airbag

Info

Publication number: GB2333071A
Application number: GB9800669A
Authority: GB
Inventors: Raymond Graham; Michael George Litton; Simon Valkenburg
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1998-01-13
Filing date: 1998-01-13
Publication date: 1999-07-14
Anticipated expiration: 2018-01-13
Also published as: GB2333071B; GB9800669D0

Abstract

A safety arrangement for use in a motor vehicle comprises an elongate element(12) having anchor plates(15,24) at opposed ends. The anchor plates are to be connected to opposite sides of the door or window opening in a vehicle. In the event that an accident occurs gas is supplied to a bladder(25) located within a pocket(17) formed in the central region(16) of the elongate element. The diameter of the central portion(16) of the elongate element thus increases which effectively shortens the length of the elongate element. The central portion(16) of the elongate element thus becomes a rigid element which can extend, for example, across a door or window opening in a motor vehicle. Straps(13,22) extend from the central region(16) to the anchor plates(15,24), thus minimising the risk of the inflatable part of the central region being punctured by stitching or the like.

Description

DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO A SAFETY ARRANGEMENT" THE PRESENT INVENTION relates to a safety arrangement, and more particularly relates to a safety arrangement adapted to be mounted in a motor vehicle such as a motor car.

It has been proposed to provide a safety arrangement in a vehicle. such as a motor car, to provide protection for the driver or occupant of the motor vehicle in the event that a side impact should occur.

US-A-5,322,322 discloses a safety arrangement of this type in which a braided tube is provided, which is formed of continuous fibres impregnated with a high elongation, air-tight elastomeric material such as silicone rubber.

In one of the described embodiments the braided tube is mounted in position with the opposed ends of the tube fixed, respectively, to a lower point on the A Post of the motor vehicle, and a relatively high point on the B-Post of a motor vehicle. The tube is initially stored in a recess which extends above the door opening of the motor vehicle, so that the tube does not extend across the door opening. A sensor is provided to sense a side impact and to activate a gas generator which inflates the tube. As the braided tube inflates, the effective length of the tube decreases and the tube forms a taut semi-rigid structural member extending across the door opening. The inflated tube is thus located adjacent the window in the door of the vehicle. The tube thus provides some degree of protection for the head of the driver or other occupant of the vehicle.

It has been found difficult to manufacture a safety arrangement of the type disclosed in US-A-5,322,322. It is difficult to provide securing or anchoring means at the opposed ends of the tube in a reliable and consistent manner. If a fastening plate or the like is sewn or stitched to the end of the tube it is difficult to ensure that the end of the tube constitutes a gas-tight seal, which is necessary for the tube to be inflatable. If stitching is used there is a risk that the side wall of the tube will be punctured. which is clearly undesirable.

The present invention seeks to provide an improved safety arrangement.

According to this invention there is provided a safety arrangement mounted in a motor vehicle, the safety arrangement comprising an elongate element, said elongate element defining a central region, the central region defining a pocket, and, at each end of the central region, a respective strap, each strap extending away from the central region and being connected to a respective anchor point, the anchor point being located on opposed sides of a door or window opening in a motor vehicle, the elongate element initially being located in a position in which it does not extend across the said window or opening, the safety arrangement further incorporating a crash sensor and a gas generator, the gas generator being adapted to generate gas to increase the diameter of the pocket to cause the elongate element to extend as a substantially rigid element across the window or opening in the motor vehicle.

Preferably the elongate element is formed using a one-piece fabrication technique.

Conveniently each strap comprises a single integral layer of fabric each strap being secured to a respective anchor plate by having a portion of the strap pass through an aperture in the anchor plate, the portion of the strap being located adjacent the rest of the strap and being connected thereto.

In one embodiment an inflatable bladder is provided which is located within the pocket, gas from the gas generator being supplied to the bladder to inflate the bladder, and thus increase the direction of the central part of the elongate element.

Alternatively fabric forming the pocket is gas impervious, and gas from the gas generator is supplied directly to the pocket to inflate the pocket, to increase the director of the central part of the elongate element.

Preferably at least in the central section of the elongate element is formed of a fabric having a substantial proportion of the yarns or threads constituting the fabric inclined at an angle of approximately 45C to the axis of the elongate member.

Consequently the elongate element is fabricated using a warp knitting technique.

Advantageously the central region defining the pocket has a substantially greater width than the width of the straps.

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 view of the door of a motor vehicle illustrating part of the A-Post and part of the B-Post, showing a safety arrangement in accordance with the invention in an initial undeployed condition, FIGURE 2 is a view corresponding to Figure 1 showing the safety arrangement in a deployed condition, FIGURE 3 is a diagrammatic view, with part cut away, of the elongate element shown in Figure 2, FIGURE 4 is a sectional view taken on the line IV-lV of Figure 3, FIGURE 5 is a sectional view taken on the line V-V of Figure 3, and FIGURE 6 is a sectional view taken on the line VI-VI of Figure 3.

Referring to Figure 1 of the accompanying drawings, a door 1 of a motor vehicle is illustrated schematically, the door being provided with a window 2.

Adjacent one side of the door is the A-Post 3 of the motor vehicle, the A-Post being located immediately adjacent the windscreen or windshield 4. Adjacent the other side of the door the substantially vertical B-Post 5 of the motor vehicle is provided.

The vehicle is provided with a crash or impact sensor 6 which is connected to a gas generator 7 so that, when a side impact is sensed by the crash or impact sensor 6, the gas generator 7 is activated. The gas generator 7 is connected to a gas supply duct 8 which extends to an inflatable bladder (not shown in Figure 1). The inflatable bladder is located within a pocket in an elongate element which will be described hereinafter in greater detail. The elongate element is initially stored, as shown in phantom in Figure 1, in a recess which is provided in the roof 9 of the motor vehicle at a position above the door opening. At one end of the recess, a first anchoring point 10 is provided, the anchoring point 10 being located at a relatively low position on the A-Post 3 of the motor vehicle, and at the other end of the recess, a second anchoring point 11 is provided, the anchoring point 11 being provided at a relatively high point on the B-Post of the motor vehicle.

Figure 2 illustrates the safety arrangement in the condition that it has shortly after a side impact has been sensed by the sensor 6.

The bladder, connected to the gas supply duct 8 has been inflated by gas from the gas generator, and as a consequence of the inflation of the bladder, the elongate element 12, (which will be described in greater detail with reference to Figure 3), now extends as a substantially rigid structural element, across the door opening adjacent the window 2 of the door 1, thus providing a degree of protection for the head of the occupant of the vehicle. The elongate element 12 extends between the anchoring points 10 and 11.

It is to be understood that in alternative embodiments the anchoring points could be located at different positions to those described and illustrated, provided that the elongate element, when inflated, is located in an appropriate position to provide protection for the head of the occupant of the vehicle.

It will be appreciated that the illustrated an-angeinent in accordance with the invention, as described above, is similar to that of US-A-5,322,322, but as will become clear from the following description, the structure of the elongate element of the present invention is very different from the structure of the elongate element of the prior U.S. Specification.

Turning now to Figure 3 of the accompanying dravvillgs, the elongate element 12 is illustrated.

The elongate element 12 in the presently described embodiment of the invention is manufactured using a one-piece fabrication technique. Such a one piece fabrication technique includes, for example, one-piece weaving and also an equivalent one-piece knitting technique. In one-piece fabrication of the elongate element, in some parts of the elongate element the fabrication technique generates a single integral layer of fabric, whereas in other areas the one-piece fabrication technique generates two separate and discrete layers of fabric.

The preferred one-piece fabrication technique to be utilised in the manufacture of elongate elements as illustrated in Figure 3 is a warp knitting technique. When warp knitting, a warp beam is located behind the knitting machine, and threads are run into the knitting machine through a guide bar which serves to locate the needles. The needles are movable and a yarn is passed from one needle to another to generate the knitted fabric. It is possible to use a two-guide bar machine, that is to say a machine with two sets of needles mounted in a bar, so that the loops can be passed fi-om one another. By using a machine of this type, it is possible to fabricate a tube or, alternatively, to combine the threads and yarns to form a single fabric.

The elongate element 12, shown in Figure 3, is provided, at one end, with a relatively narrow strap portion 13. The strap potion 13 is formed as a single fabric layer. One end of the strap 13 is passed through a slot 14 provided in a anchor plate 15, and is then folded back to lie adjacent the rest of the strap 13, and the adjacent parts of the strap 13 are then stitched or otherwise secured together. Thus, at the point where the sectional view of Figure 4 is taken, the strap 13 is effectively of double thickness where the two adjacent parts of the strap are sewn or otherwise secured together. The other end of the strap 13 is connected to the central region 16 of the elongate element 12. The central region 16 has a width greater than the width of the strap 13.

In the central region 16 of the elongate element, the one-piece fabrication technique utilised to manufacture the elongate element is so controlled that two separate layers of fabric 18,18' are produced which are integrated or connected together towards their outer edges in regions 19,20 which can be considered to constitute seams. Altematively, if the preferred warp knitting technique is utilised with a two-guide bar machine, this central region 16 of the elongate element may be made to be tubular, with no discernible seam, and when the tubular portion is flat, it will comprise two adjacent layers of fabric 18,18'.

The central region 16 of the elongate element 12 defines a central pocket 17. Towards one end of the central region 16 an aperture 21 is provided which gives access to the central pocket 17.

At the other end of the elongate element, that is to say the end opposed to the strap 13, a further strap 22 is provided, the strap 22 being of the same size and configuration as the strap 13. Thus the strap 22 has an end portion passed through a slot 23 formed in an anchor plate 24, with that end portion being folded back to lie adjacent the rest of the strap 22, the adjacent portions of the strap 22 being stitched or otherwise secured together.

As can be seen from Figure 6, the region of the strap 22, where the sectional view of Figure 6 is taken, is only made of single thickness of fabric.

The gas supply duct 8 extends through the opening 21 into the pocket 17 where the gas supply duct 8 is connected to an inflatable bladder 25, shown in phantom in Figure 3. The inflatable bladder may be made of rubber or an equivalent material.

It is to be appreciated that in fabricating the elongate element 12, at least in the central region 16, a substantial proportion of the threads or yarns extend, as illustrated in region 26, at an angle of approximately 45" to the axis of the elongate element. This provides the elongate element with same property as the elongate tube described in US-A-5,322,322, namely that the length of the elongate element will reduce when the elongate element is deployed when the diameter of the central region 16 increases as a consequence of the generation of gas from the gas generator 7.

In the described embodiment of the invention, the elongate element itself is not inflatable, but the bladder 25 that is inserted into the pocket 17 that is inflatable. The bladder will be inserted into the pocket 1 7 after the elongate element 12 has been fabricated, and after any stitching or sewing procedures necessary to connect the straps 13 and 22 to the anchor plates 15 and 24 have been completed. Thus, the risk of inadvertently puncturing the inflatable element is minimised.

In a modified embodiment of the invention, the pocket 17 may be a sealed pocket, and the fabric utilised to form the pocket may be substantially gas-tight, and gas from the gas generator may be directed to the interior of the pocket so that the pocket itself may be inflated. Because the end straps extend away from the central pocket, and because any stitching is effected solely in the region of the end straps, the risk of inadvertently puncturing the inflatable part of the elongate element is minimised.

It is envisaged that the manufacture of the one-piece fabricated elongate element 12 will be relatively straightforward, with the manufacturing procedure being totally automated, with the exception of the sewing or stitching required to mount the anchor plates 15 and 24 on the straps 13 and 22.

When a side impact is sensed, the gas generator 7 will be activated and the bladder 25 will be inflated, or the pocket itself will be inflated. The diameter of the central portion 16 of the elongate element will increase thus reducing the effective length of the elongate element 12. As a consequence, the elongate element 12 moves from the initial or stored condition shown in Figure 1 to the deployed condition shown in Figure 2.

Claims

CLAIMS: 1. A safety arrangement mounted in a motor vehicle, the safety arrangement comprising an elongate element, said elongate element defining a central region, the central region defining a pocket, and, at each end of the central region, a respective strap, each strap extending away from the central region and being connected to a respective anchor point, the anchor point being located on opposed sides of a door or window opening in a motor vehicle, the elongate element initially being located in a position in which it does not extend across the said window or opening, the safety arrangement further incorporating a crash sensor and a gas generator, the gas generator being adapted to generate gas to increase the diameter of the pocket to cause the elongate element to extend as a substantially rigid element across the window or opening in the motor vehicle.
2. An arrangement according to Claim 1 wherein the elongate element is formed using a one-piece fabrication technique.
3. A safety arrangement according to Claim 1 or 2 wherein each strap comprises a single integral layer of fabric, each strap being secured to a respective anchor plate by having a portion of the strap pass through an aperture in the anchor plate, the portion of the strap being located adjacent the rest of the strap and being connected thereto.
4. A safety arrangement according to any one of the preceding Claims wherein an inflatable bladder is provided which is located within the pocket, gas from the gas generator being supplied to the bladder to inflate the bladder and thus increase the diameter of the central part of the elongate element.
5. A safety arrangement according to any one of the preceding Claims wherein the fabric forming the pocket is gas impervious, and gas from the gas generator is supplied directly to the pocket to inflate the pocket, to increase the diameter of the central part of the elongate element.
6. A safety arrangement according to any one of the preceding Claims wherein, at least in the central section of the elongate element is formed of a fabric having a substantial proportion of the yarns or threads constituting the fabric inclined at an angle of approximately 45" to the axis of the elongate member.
7. A safety arrangement according to any one of the preceding Claims wherein the elongate element is fabricated using a warp knitting technique.
8. A safety arrangement according to any one of the preceding Claims wherein the central region defining the pocket has a substantially greater width than the width of the straps.
9. A safety arrangement substantially as herein described with reference to and as shown in the accompanying drawings.
10. Any novel feature or combination of features disclosed herein.