GB2362140A

GB2362140A - Apparatus and method for folding an air bag

Info

Publication number: GB2362140A
Application number: GB0011533A
Authority: GB
Inventors: Wallner Robert; Thomas Reiter
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2000-05-12
Filing date: 2000-05-12
Publication date: 2001-11-14
Anticipated expiration: 2020-05-12
Also published as: WO2001085498A1; GB0011533D0; GB2362140B; DE10196171T1; DE10196171B4; AU2001256927A1

Abstract

An apparatus 1 for folding an air bag 5 comprises at least two panels 3,4 moveable between an initial substantially horizontal position to a substantially vertical position, a housing 6 located between the panels for receiving the air bag, and compressor means (17,18 in figure 3) for applying a generally downward compressional force to the air bag. In use the air bag is placed on the initially horizontal panels before they are pivoted about axes 11,12 into a vertical position so that the air bag may fall towards the housing 6 (see figure 3), compressor means (17,18) then forces the air bag into the housing. The compressor means may be formed from three separate parts (see figures 5 to 7) so that initially the centre part of the air bag is compressed into the housing 6 before the edges are folded over, and there may be a divider panel 9 located between the moveable panels 3,4 so that the air bag is folded in two sections.

Description

2362140 PATENTS ACT 1977 P14249QB-NIJsd DESCRIPTION OF INVENTION

"IMPROVEMENTS IN OR RELATING TO AN APPARATUS FOR A METHOD OF FOLDING AN AIR-BAG59 THE PRESENT INVENTION relates to a method of and apparatus for folding an air-bag, such as an air-bag intended for use to provide protection for an occupant of a motor vehicle in the event that an accident should arise.

It has been proposed previously to provide an air-bag mounted in a motor vehicle adapted to be inflated in the event that an accident should occur, the inflated air-bag being located in front of an occupant of the vehicle in order to provide protection for that vehicle occupant.

A conventional air-bag comprises a fabric bag which is initially stored within a housing. Typically the air-bag is initially laid out substantially flat, with two superimposed layers of fabric lying immediately adjacent each other, and then the air-bag is folded to be inserted into the housing. In a conventional folding technique, the two layers of fabric are folded together simultaneously about a single foldline when each fold is created. This has the effect of creating, within the air-bag, regions where no gas may flow since the simultaneous fold of two adjacent layers of fabric is such that no gas may flow past the fold.

2 This may be undesirable, in that the air-bag may possess an undesirable inflation characteristic.

It is now proposed, therefore, to fold an air-bag into such a way that the different layers of fabric are folded or crumpled, the layers preferably being folded or crumpled at different locations, so that there is an air-flow through the entire air-bag during initial inflation thereof.

The present invention seeks to provide a method of and apparatus for folding an air-bag.

According to one aspect of this invention there is provided an apparatus for folding an air-bag, the apparatus comprising at least two panels moveable between an initial substantially horizontal position and a terminal substantially vertical position, means to locate and retain a housing for an air-bag in a predetermined position between the panels so that, when the panels have been moved to a substantially vertical position, the panels extend substantially upwardly from opposed parts of the housing, the apparatus further comprising compressor means to apply a generally downward compressional force on an air-bag present in the space between the substantially vertical panels to compress at least a part of the air-bag into the housing.

Preferably two said panels are provided which are mounted so that each panel may rotate about an axis substantially coincident with an edge of the panel, the two axes being parallel and spaced apart, the spacing between the axes being substantially equal to the width of the said housing.

3 Conveniently the compressor means comprise three elements introducable between the panels to apply a downward force, the elements being adapted to move initially downwardly in synchronism, a central element being adapted to move downwardly in isolation, the central element being dimensioned to force the folded air-bag into the housing.

In a modified embodiment of the invention the apparatus comprises two additional flaps, each flap being adapted for movement about an axis coincident with an edge of the flap, the said two axes for the panels being parallel and spaced apart and substantially perpendicular to the axes of rotation of the plates, the panels being adapted to be moved to a position between the plates to defme, with the plates, a chamber having a cross-section substantially corresponding to that of the housing.

Conveniently the apparatus is provided with a divider adapted to be located between the panels, when in the substantially vertical position to divide the space between the panels into two separate chambers.

The invention also relates to a method of folding an air-bag, the method comprising the steps of initially laying the air-bag on a table formed from at least two panels, with a housing into which the air-bag is to be folded being located between the panels, subsequently moving the panels to a substantially vertical position and applying a downward compressional force to the air-bag located between the panels.

Conveniently a divider is provided which is initially located in position and which divides the space between the two panels, when they have been moved to the vertical position, into two separate chambers.

4 Advantageously after an initial compressional stage, a single compressing element applies a compressional force to the folded air-bag to force at least part of the air-bag into the housing.

Preferably before the said force is applied to drive the air-bag into the housing, two additional flaps are moved to a vertical position between the plates to define a chamber having a cross-sectional substantially corresponding to that of the housing.

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 an apparatus in accordance with the invention in the first condition, FIGURE 2 is a front view of the apparatus shown in Figure 1, FIGURE 3 is a view corresponding to Figure 1 showing a subsequent stage during the folding of an air-bag, FIGURE 4 is a front view of the apparatus as shown in Figure 3, FIGURE 5 is a view corresponding to Figure 4 showing a subsequent stage during the folding of an air-bag, FIGURE 6 is a view corresponding to Figure 5 showing a further view in folding an air-bag, FIGURE 7 is a diagrammatic view of an air-bag and a partially folded air- bag illustrating a final step in the folding process, FIGURE 8 is a view corresponding to Figure 4 showing a modified apparatus, FIGURE 9 is a view corresponding to Figure 8 showing a subsequent step during the folding of an air-bag, FIGURE 10 is a view corresponding to Figure 9 showing a further step in folding an air-bag, and FIGURE 11 is a view corresponding to Figure 10 showing a final step in the folding of an air-bag.

Referring initially to Figure I of the accompanying drawings, a folding apparatus I comprises a table constituted by two initially horizontal panels 3, 4. A central recess or aperture 5 is provided between the flaps, and within this recess or aperture a housing 6 into which an air-bag is to be folded is located. Contained within the housing 6 is an inflator 7 or gas generator, and connected to the housing and/or the gas generator is an air-bag 8. In an initial condition of the apparatus, as shown in Figure 1, the air-bag 8 is stretched out over the substantially horizontal panels 3, 4.

A vertical divider panel 9 may be provided which is inserted into the housing. The panel may be of any convenient sheet material, such as sheet metal, or even plastics material. The panel has a width which is substantially equal to the width of the housing 6 into which the air-bag 8 is to be folded.

6 As can be seen from Figure 2, the panels 3, 4 have a substantial width relative to the width of the housing 6.

The panels 3, 4 are mounted in position so that they may be rotated about respective substantially horizontal axes 11, 12 which are located at the ends of the panels 3, 4 adjacent the housing 6. Thus each panel may rotate about an axis substantially coincident with the edge of the panel, the two axes being parallel and spaced apart, the spacing between the axes being substantially equal to the width of the housing. The panels 3, 4 may thus be swung upwardly, as generally indicated by the arrows 13, 14 until the panels are substantially vertical. The panels 3,4, now extend upwardly from opposed parts of the housing 6. The upper surface of each panel may be of a relatively high friction material so that the fabric of the air-bag 8 will cling to the surface of the panel as the panel is swung upwardly. However, when the panels reach the vertical position the air-bag will fall, in loose folds, as shown in Figure 3. It can be seen that as the panels 3, 4 are swung upwardly to the substantially vertical position illustrated in Figure 3 they define, together with the divider 9, two chambers 15, 16. The air-bag will fall to the lower part of each of the chambers under the force of gravity, and in so falling will generate loose folds. Although, when the air-bag was initially spread out on the table constituted by the flaps 3, 4, the air-bag could be considered to comprise two immediately adjacent layers of fabric, after the air-bag has fallen within the chambers 15, 16, the air-bag comprises two separated layers of fabric.

A first compressor assembly 17 is introduced into the top of the chamber 15, and a second compressor assembly 18, of similar form, is introduced into the upper part of the chamber 16. As can be seen from Figure 4, the first compressor assembly 17 comprises three individually 7 movable compressing elements 19, 20, 21, and the second compressor 18 will be of similar form.

Initially the three compressing elements 19, 20, 21 are moved downwardly in synchronism, thus applying a generally downward compressional force to the loose folds of the air-bag as retained within the chamber 15. The compressor assembly 18 is operated in a similar way. The situation illustrated in Figure 5 is thus achieved, with a substantial part of the air-bag 8 having been compressed and forced into the housing 6, but with parts 22, 23 of the air-bag projecting out to either side of the housing.

Subsequently the central element 20 of the compressor assembly 17 is forced downwardly, as shown in Figure 6, to compress a substantial part of the folded air-bag 8 within the housing 6. Finally, the housing is removed from the apparatus shown in Figure 7, the divider 9 is withdrawn and the two projecting parts 22, 23 of the air-bag are folded inwardly and downwardly as shown by the arrows 24, 25, 26 so that the entire air- bag is folded and lies within the housing 6.

By folding, in the manner described above, the air-bag, when in the folded state, can be considered to comprise two crumpled, separated folded layers of fabric. This may facilitate the flow of gas from the inflator or gas generator 7 throughout the air-bag during initial inflation of the air-bag. The air-bag is also divided into two separate folded volumes by the divider 9. Thus facilitates the deployment of the air-bag.

Referring now to Figure 8, a modified embodiment of the invention is shown. In this embodiment of the invention, the compressor assembly 17 and the compressor assembly 18 are modified in such a way that the two 8 compressing elements 19 and 21 located to either side of the central compressing element 20 are provided with arcuate under-surfaces 30, 31 so that each element 19, 21 is provided, at its edge which is remote from the central portion 20, with a depending pointed claw 32, 33. The apparatus shown in Figure 8 corresponds, in other respects, with the apparatus shown and described with reference to Figures 1 to 7, save that the apparatus comprises additional panels 34, 35, which are initially horizontal and co-planar with the flaps 3, 4, but which extend, at either end of the housing 6, in the gap defined between the panels 3, 4. The additional flaps 34, 35 are each adapted to pivot about substantially horizontal axes 36, 37 adjacent the ends of the housing 6. Each flap 36, 37 is adapted to move about an axis coincident with its edge, the two axes being parallel and spaced-apart by a distance equivalent to the length of the housing 6. The axes are perpendicular to the axes of rotation of the panels 3, 4.

In operation of the device illustrated in Figure 8, the operational cycles described above with reference to Figures 1 to 4 are carried out, and the compressor assembly 17 is moved downwardly, as shown in Figure 9, in a manner corresponding to that as shown in Figure 5. However, following downward movement of the compressor assembly, the additional flaps 34, 35 are moved upwardly, as indicated by arrows 38, 39, shown in Figure 10, the firee edges of the additional flaps, as they move upwardly, engaging the arcuate under-surfaces 30, 31 of the two compressing elements 19, 21 located to either side of the central compressing element 20. Thus the entire folded air-bag is constrained to be within a volume located beneath the central compressing element 20, the air-bag being constrained between the vertical panels 3, 4, and the vertical additional flaps 34, 35. As shown in Figure 11, the central compressing element 20 then moves downwardly forcing the entire folded airbag into the housing 6. The central divider is then removed before the 9 housing 6, together with the air-bag 8 folded within it, is removed from the described apparatus.

Again, the folded air-bag will be folded as separated crwnpled layers of fabric to facilitate the flow of gas through the air-bag from the inflator or gas generator when the air-bag is to be deployed.

In the present specification "comprise" means 'Includes or consists of' and "comprisinj 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 apparatus for folding an air-bag, the apparatus comprising at least two panels moveable between an initial substantially horizontal position and a terminal substantially vertical position, means to locate and retain a housing for an air-bag in a predetermined position between the panels so that, when the panels have been moved to a substantially vertical position, the panels extend substantially upwardly from opposed parts of the housing, the apparatus further comprising compressor means to apply a generally downward compressional force on an air-bag present in the space between the substantially vertical panels to compress at least a part of the air-bag into the housing.

2. An apparatus according to Claim 1 wherein two said panels are provided which are mounted so that each panel may rotate about an axis substantially coincident with an edge of the panel, the two axes being parallel and spaced apart, the spacing between the axes being substantially equal to the width of the said housing.

3. An apparatus according to Claim 1 or Claim 2 wherein the compressor means comprise three elements introducable between the panels to apply a downward force, the elements being adapted to move initially downwardly in synchronism, a central element being adapted to move downwardly in isolation, the central element being dimensioned to force the folded airbag into the housing.

4. An apparatus according to Claim 2 or 3 wherein the apparatus comprises two additional flaps, each flap being adapted for movement about an axis 11 coincident with an edge of the flap, the said two axes for the flaps being parallel and spaced apart and substantially perpendicular to the axes of rotation of the panels, the flaps being adapted to be moved to a position between the panels to de-fine, with the plates, a chamber having a cross-section substantially corresponding to that of the housing.

5. An apparatus according to any one of the preceding Claims provided with a divider adapted to be located between the panels, when in the substantially vertical position to divide the space between the panels into two separate chambers.

6. A method of folding an air-bag, the method comprising the steps of initially laying the air-bag on a table formed from at least two panels, with a housing into which the air-bag is to be folded being located between the panels, subsequently moving the panels to a substantially vertical position and applying a downward compressional force to the airbag located between the panels.

7. A method according to Claim 6 wherein a divider is provided which is initially located in position and which divides the space between the two panels, when they have been moved to the vertical position, into two separate chambers.

8. A method according to Claim 6 or 7 wherein after an initial compressional stage, a single compressing element applies a compressional force to the folded air-bag to force at least part of the air-bag into the housing.

9. A method according to Claim 8 wherein before the said force is applied to drive the air-bag into the housing, two additional flaps are moved to a 12 vertical position between the plates to define a chamber having a crosssectional substantially corresponding to that of the housing.

10. A method of folding an air-bag substantially as herein described with reference to Figures 1 to 7.

11. A method of folding an air-bag substantially as herein described with reference to Figures 1 to 4 and 8 to 11.

12. An apparatus for folding an air-bag substantially as herein described with reference to and as shown in Figures 1 to 7 of the accompanying drawings.

13. An apparatus for folding an air-bag substantially as herein described with reference to and as shown in Figures 1 to 4 as modified by Figures 8 to 11.

14. An air-bag whenever folded by the method of any one of Claims 6 to 11.

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