GB2339557A

GB2339557A - A side impact air bag

Info

Publication number: GB2339557A
Application number: GB9815413A
Authority: GB
Inventors: Markus Schels; David Stow; Simon Valkenburg
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1998-07-15
Filing date: 1998-07-15
Publication date: 2000-02-02
Anticipated expiration: 2018-07-15
Also published as: GB9815413D0; GB2339557B

Description

2339557 PATENTS ACT 1977 P12592GB/NHF Title: IMPROVENENTS IN OR RELATING

TO A SAFETY DEVICE DescriRtion of Invention THE PRFSENT INVENTION relates to a safety device, and more particularly relates to a safety device to be mounted in a motor vehicle to provide protection for the occupants of the vehicle in the event that a side impact accident should arise, US-A-5,322,322 discloses a safety arrangement of the type in which a braided tube is provided which is formed of continuous fibres impregnated with a high elongation, airtight 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 vehicle and to a relatively high point on the B-post of the vehicle. The tube is initially stored in a recess which extends above the door opening of the 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, so the effective length of the tube decreases, and the tube then forms an inflated taught semi-rigid structural member extending across the door opening. The inflated tube thus extends across the window opening formed in the door of the vehicle, The tube provides some protection for the head of the occupant of the vehicle, and may prevent the head of the occupant being thrown out through the window opening.

2 In another descn-bed embodiment two tubes, each similar to that described above, are mounted so that, when inflated, they extend across the window opening parallel to each other. Each of these tubes is individually mounted in position. Because the tubes are separate from each other there is a risk that in an accident situation, when the forces exerted on an occupant of the vehicle may be high, one tube may be deflected from its inflated position, and the head or neck of the occupant of the vehicle may become trapped between the two tubes.

The present invention seeks to prove an improved safety device, According to this invention there is provided a safety device for a motor vehicle, the device comprising an inflatable element associated with a gas generator which is actuated by a sensor responsive to a side impact or roll over situation to inflate the inflatable element, the inflatable element comprising an elongate element having a first strap at one end with anchoring means to secure 0 the end of the first strap in position and a second strap at the other end with anchoring means to secure the end of the second strap in position, and, between the straps, an inflatable chamber adapted to be inflated on actuation of the gas generator, the chamber being integrally formed and having a plurality of limbs which c)aend parallel with the axis of the elongate element.

Preferably an inflatable bladder is provided within the chamber.

Alternatively the interior of the chamber is coated with a gas impervious material.

3 In one embodiment of the invention the limbs comprise two parallel limbs interconnected by a transverse passage at one end thereof In an alternative embodiment of the invention the limbs comprise three parallel limbs, there being one relatively long limb connected by transverse passages at either end thereof to two shorter limbs which are coaxial, there being a space between the adjacent terTninal ends of the shorter limbs.

Conveniently the said space is filled with a region of single layer fabric.

Preferably a locating tab is provided which extends transversely to the elongate element intermediate the ends thereof, the tab incorporating anchor means to secure the end of the tab in position.

Conveniently the inflatable element is adapted to reduce in length on inflation of the said chamber, Preferably the inflatable element is fabricated using a one-piece fabrication technique.

In a preferred embodiment the elongate element is integrally formed.

Conveniently the elongate element is made using a one-piece weaving technique.

Advantageously the elongate element is made using a knitting process, the preferred process being a warp knitting process.

4 Preferably the elongate element is made using a double needle bar Raschel using multiple guide bars.

Conveniently the knitting is of a diamond pattern.

The invention also relates to a safety device as described above when mounted in a motor vehicle, the anchor means of the first strap being mounted to a point adjacent the lower part of the A-post of the vehicle, and the anchor means on the second strap being mounted to a point on a post to the rear of the A-post of the vehicle, or being mounted to the roof of the vehicle.

Preferably the anchor means on the second strap are mounted to the Bpost of the vehicle.

In a modified embodiment the anchor means on the second strap are mounted to a post to rear of the B-post of the vehicle, such as the C-post of the vehicle.

Conveniently, in the uninflated state, the element is retained in a recess or housing that extends above a door opening of the vehicle.

Preferably the recess or housing is non-linear, the anchor means on the straps being mounted to the recess or housing adjacent the opposed ends thereof.

Conveniently the anchor means on the locating tab are connected to the vehicle at a point above the door opening of the vehicle and between the ends of the said first and second straps.

In order that the invention may be more fully 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 illustration of part of the interior of a vehicle showing a recess or housing above the door opening which contains a safety device in accordance with the invention, FIGURE 2 is a view, corresponding to Figure 1, showing the safety device in a deployed condition, FIGURE 3 is a diagrammatic view illustrating warp knitting, and FIGURE 4 is a view, corresponding to Figure 2, illustrating a second embodiment of the invention in a deployed condition.

Referr-mg initially to Figure I of the accompanying drawings a motor vehicle, such as a motor car, has an A-post I and a B-post 2 located on opposite sides of a door opening 3. The B-post is thus located to the rear of the A-post. Provided in the roof 4 of the vehicle, at a position above the door opening 3 is a recess or housing S. The recess or housing 5 extends from a position adjacent the bottom part of the A-post 1, across the door opening 3, and part way down the B-post 2. The recess or housing 5 may initially be concealed behind the roof lining or trim of the vehicle, or may be provided with an appropriate cover. It is preferred that the recess or housing is not obtrusive. The housing contains, in an initial uninflated state, an inflatable element.

6 Referring now to Figure 2 the inflatable element 6 is shown in its inflated state. The inflatable element 6 is an integral elongate element which may be formed using a one piece weaving or one piece knitting technique. The element 6 defines, at one end, a strap 7 which is proved with anchoring means, in the form of an aperture 8 by means of which the end of the strap 7 is connected to part of the housing or recess 5 at a relatively low position on the A-post I of the vehicle. The element 6 defines, at the other end, a strap 9 which is provided with anchoring means, in the form of an aperture 10 by means of which the end of the strap 9 is secured to part of the housing or recess 5 at a position on the B-post of the vehicle. Alternatively the aperture 10 may be mounted to part of the roof of the vehicle.

Betwc= the two straps 7 and 9 the, elcmcnt 6 defines a hollow chamber 11. The chamber 11 is integrally formed and has a plurality of parallel limbs, constituted by the two limbs 12, 13, which extend axially of the elongate element 6. At one end the limbs are interconnected by a transverse passage 14, and thus the interior of the hollow chamber I I can be considered to be a substantially 'U' shaped cavity, While the interior of the hollow chamber I I may be coated with a gas or air impervious material, such as a silicone rubber material, it is preferred that the chamber I I should contain an inflatable bladder made, for example, from rubber. The bladder ( or the chamber if no bladder is provided) is connected, by means of a gas flow conduit 15 that extends through the hollow interior of the strap 7 to a gas generator 16 which is associated with a sensor 17 adapted to respond to a side impact or roll- over situation to activate the gas generator to inflate the inflatable element 6- 7 The integrally formed elongate element 6 also incorporates a locating tab 18 that extends transversely from a central part of the element intermediate the ends of the element, namely the upper part of the upper limb 12 of the chamber 11, to the part of the recess or housing 5 located above the door opening 3. The tab 18 is provided with anchoring means, defined by an aperture 19, by means of which the tab 18 is secured to the recess or housing 5.

The entire elongate element 6 is preferably manufactured using a onepiece fabrication technique such as one-piece weaving or one-piece knitting. In one-piece fabrication in some parts of the element the fabrication technique generates a single integral layer of fabric, whereas in other areas the singlepiece fabrication technique generates two separate and discrete layers of fabric. Thus, in the described element 6 the strap 9 and the tab 18 are formed of a single integral layer of fabric, while the area defining the chamber 11 is formed of two discrete fabric layers. The fabric layers are interconnected by a seam 20 which separates the two limbs 12, 13 of the chamber 11. The seam 20 may be an uniterrupted seam, but may alternatively comprise a plurality of adjacent seam lengLhs. The spaces between the seam length may comprise intercommunications between the limbs 12, 13 of the chamber 11, or may comprise small apertures extending through the integrally formed chamber 11.

Apertures, such as the apertures 22, 23 and 24 are formed in one of the fabric layers defining. the chamber I I to provide access to the interior of the chamber in the embodiment where an inflatable bladder is used to facilitate the insertion of the bladder into the cavity. The element may be woven with drawthreads in position passing through the apertures to be engaged with the bladder and pulled to draw the bladder into position.

A one piece weaving technique may be used, with the orientation of the warp and weft threads being selected so that each of the limbs 12 and 13 of the chamber I I are effectively tubes where the warp and weft yams extend at approximately 45 degrees to the axis of the tube. This creates a 'diamond' pattern of weaving. On inflation of the inflatable element the diameter of the tubes will increase, with a consequent reduction of the effective length of the tubes.

The preferred one-piece fabrication technique is a knitting technique such as warp knitting. Ile warp knitting is performed on a double needle bed Raschel using multiple guide bars, typically eight guide bars, to create a substantially tubular structure of the strap 7, the integral double tubular structure of the chamber 11, and the integrally formed single layer of fabric that forms the strap 9, whilst facilitating the formation of the apertures 22, 23, and 24 that are provided for the insertion of the bladder, and using a 'diamond' pattern of knitting. Figure 3 illustrates a typical 'diamond' pattern, in which the knitted threads 25 define diamond shaped apertures 26. It is to be understood that the inflatable element 6 will, as a consequence of the use of the 'diamond' pattern, effectively contract in length as the diameter of each of the limbs 12, and 13 of the chamber 11 increases on inflation of the inflatable element 6.

If the sensor 17 senses a side impact or roll-over situation the gas generator 16 is activated and the chamber I 1,_ -of the bladder within the chamber 11 is inflated. The inflatable element 6 thus emerges from the recess or housing 5, and as the diameter of the limbs 12, 13 of the chamber increases, so the effective length of the inflatable element is reduced, and the inflatable element is thus stretched taughtly as a rigid or semi-rigid structural element across the 9 door opening 3 of the vehicle. The locating tab 18 also becomes tightened and the tab 18 prevents rotation of the inflated element 6 about an axis defined between the anchor means 8 and 10.

The two limbs 12, 13 of the chamber I I are superimposed, lying one above the other, thus presenting a large area lying in a vertical plane to provide protection for the head of an occupant. The structural element constituted by the inflatable element will resist any tendency of the head of the occupant to be thrown out of the window opening formed in the door of the vehicle that is accommodated within the door opening 3. Because the two limbs 12, 13 of the chamber I I are formed integrally, being separated only by a seam between the two layers of fabric that define the whole of the chamber 11, there is no risk of the head of the occupant passing between, or becoming trapped between, the two limbs 12 and 13.

Figure 4 illustrates an embodiment of the invention that is in many respects similar to that shown in Figure 2. The inflatable element 26 of this embodiment does have some features in common with the embodiment of Figure 2, which are identified by identical reference numerals and which will not be redescribed in detail, but also has some features that are different. In particular in this embodiment the chamber 27, which is located centrally of the inflatable element 26 is provided with one lower limb 28 that extends from the strap 7 to the strap 9, with each end of the lower limb being connected, by means of a respective transverse passage 29, 30, to a respective upper limb 3 1, 32. The upper limbs 31, 32 extend parallel to the lower limb, axially of the inflatable element 26, towards each other. The space between the adjacent terminal ends of the upper limbs 31, 32, is filled with an integrally formed single layer of fabric 33, and the locating tab IS extends upwardly from this layer of fabric 33 to a point above the B-post of the vehicle.

In this embodiment the recess or housing 5 provided in the roof 4 of the vehicle extends from a point adjacent the lower end of the A-post across the door opening 3, across the top of the B-post and across the rear door opening 34 to terminate on a post to the rear of the B-post, in this case the C-post 35. The anchoring means 8 on the strap 7 is connected to the recess or housing 5 at a lower position on the A-post while the anchoring means 10 on the strap 9 are connected to a part of the recess or housing 5 on the C-post of the vehicle.

71be limbs 28, 31 and 32, are formed as woven tubes with a 'diamond' pattern of weaving as described above, or preferably are formed as a warp knit structure with a 'diamond' pattern as described above. On inflation of the inflatable clemcnt 26 following scusing of a side impact or roll over by the sensor 17 and consequent activation of the gas generator 16 the inflatable element, after it has emerged from the recess or housing 5 becomes tightened betwcen the anchor rne= 8 and 10. The inflated element 26 then stretches taughtly as a rigid or semi rigid structural rlement across the door openings 3 and 34 of the motor vehicle with the locating tab 18 preventing rotation of the inflated element 26 about an axis between the anchoring means 8 and 10. In the region of each door opening the inflated element 26 presents two superimpose4 inflated limbs which provide a large area to offer protection to the head of an occupant of a front seat and a rear seat in the motor vehicle.

CLADSAS 1. A safety device for a motor vehicle, the device comprising an inflatable element associated with a gas generator which is actuated by a sensor responsive to a side impact or roll over situation to inflate the inflatable clement, the inflatable element comprising arL elongate clement having a first strap at one end with anchoring means to secure the end of the first strap in position and a second strap at the other end with anchoring means to secure the end of the second strap in position, and, between the straps, an inflatable chamber adapted to be inflated on actuation of the gas generator, the chamber being integrally formed and having a plurality of limbs which extend parallel with the axis of the elongate clement.

2. A device according to claim I wherein an inflatable bladder is provided within the chamber.

3. A device according to claim I wherein the interior of the chamber is coated with a gas impervious material, 4. A device according to any one of the preceding claims wherein the limbs comprise two parallel Umbs interconnected by a transverse passage at one end thereof 5. A device according to any one of claims I to 3 wherein the limbs comprise three parallel limbs, there being one relatively long limb connected by transverse passages at either end thereof to two shorter limbs which are coaxial, there being a space between the adjacent tcrminal ends of the shorter limbs.

12 6. A device according to claim 5 wherein the said space is filled with a region of single layer fabric.

7. A device according to any one of the preceding claims wherein a locating tab is provided which extends transversely to the elongate element intermediate the ends thereot the tab incorporating anchor means to secure the end of the tab in position.

8. A device according to any one of the preceding claims wherein the inflatable element is adapted to reduce in length on inflation of the said chamber.

9. A device according to my one of the preceding claims wherein the inflatable element is integrally formed.

10. A device according to any one of the preceding claims wherein the inflatable element is fabricated using a one-piece fabrication technique.

11 - A deyire according to claim 10 wherein the elongate element is made using a one-piece weaving technique.

12. A device according to claim 10 wherein the elongate element is made using a knitding process.

13. A device according to claim 12 wherein the elongate element is made using a warp knitting process.

13 14. A device according to claim 13 wherein the elongate element is made using a double needle bar Raschel using multiple guide bars.. 1 15, A device according to claim 12, 13 or 14 wherein the ki-iitting is of a diamond pattern.

16. A device according to any one of the preceding claims mounted in a motor vehicle, the anchor means of the first strap being mounted to a point adjac,ent the lower part of the A-post of the vehicle, and the anchor means on the second strap being mounted to a point on a post to the rear of the A-post of the vehicle, or being mounted to the roof of the vehicle.

17. A device according to claim 16 wherein the anchor means on the second strap are mounted to the B-post of the vehicle.

18. A dcvire according to claim 16 wherein the anchor means on the second strap are mounted to a post to rear of the B-post of the vehicle.

19. A device according to claim 18 wherein the anchor means on the second strap are mounted to the C-post of the vehicle.

20. A device according to any one of claims 16 to 19 wherein, in the uninflated state, the element is retained in a recess or housing that extends above a door opening of the vehicle.

21. A device according to claim 20 wherein the recess or housing is nonlinear, the anchor means on the straps being mounted to the recess or housing adjacent the opposed ends thereof 14 22, A device according to any one of claims 16 to 21 as depend ' antupon claim 7 wherein the anchor means on the locating tab are connected to the vehicle at a point above the door opcning of the vehicle and between the ends of the said first and second straps.

23. A safety device substantially as herein described with reference to, and as shown in, Figures I to 3 of the accompanying drawings.

24. A safety device substantislly as licrein described with reference to, and as shown in, Figures I to 3 as modified by Figurc 4 of the accompanying drawings.

25. Any novel feature or combination of features disclosed herein