GB2587385A

GB2587385A - Airbag assemblies for vehicles

Info

Publication number: GB2587385A
Application number: GB1913872.6A
Authority: GB
Inventors: Jan Swiniarski Michal; John Scott Ward Marcus
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2021-03-31
Anticipated expiration: 2039-09-26
Also published as: DE102020122117A1; GB201913872D0; CN112550207A; GB2587385B

Abstract

Provided is an airbag assembly 100 which is suitable for deployment from a vehicle ceiling 5. The assembly 100 comprises an inflator 120, and a two-chamber airbag 110 which can be made of a single sheet of material. The first chamber 112 extends from the ceiling and over an interior surface of the vehicle when it inflates; and the second chamber 114 increases in volume when the first chamber 112 inflates, and is filled by ambient air drawn in through a valve 114a. Also provided is a vehicle assembly 2 comprising an interior surface 8 adjacent to a roof 4; an interior trim portion 6 attached to the interior surface 8; and the airbag assembly 100. The second chamber 114 may be positioned between the first chamber 112 and the interior surface such that a passenger travelling towards the interior surface 8 during a collision will initially collide with the first chamber 112.

Description

Airbag assemblies for vehicles

Technical Field

The present disclosure relates to airbag assemblies for vehicles and is particularly, although not exclusively, concerned with airbag assemblies for vehicles, which improve positioning of the airbags within the vehicle.

Background

It is desirable for the space within the interior of a vehicle, e.g. a motor vehicle, that is available for occupants to be increased. One option for increasing the space available for occupants is to reduce the size and/or adjust the position of a front interior trim portion of the vehicle that includes the instrument panel.

Front occupant airbags and their inflators are often housed within the front interior trim portion. Any reductions in the size of the front interior trim portion and/or changes in its position within the vehicle interior may conflict with the requirements for packaging the airbag assembly, and/or for directing and supporting deployment of the front airbag.

Statements of Invention

According to an aspect of the present disclosure, there is provided an airbag assembly for a vehicle, the assembly comprising an inflator; and an airbag configured to be deployed from a structure of the vehicle, such as a roof structure, to inflate over an interior surface of the vehicle, e.g. formed by a windscreen of the vehicle, in order to cushion impacts between an occupant of the vehicle and the interior surface during a collision of the vehicle, wherein the airbag comprises: a first chamber configured to extend from the structure across the interior surface of the vehicle when the first chamber is inflated; and a second chamber, the second chamber arranged relative to the first chamber such that inflation of the first chamber acts to increase an interior volume of the second chamber, wherein the second chamber comprises a valve for allowing ambient air, e.g. from outside of the airbag assembly, to be drawn into the second chamber as the volume of the second chamber increases.

The airbag may be configured to substantially fill a space between the interior surface and an interior trim portion, when the airbag is inflated. The interior trim portion may comprise an instrument panel of the vehicle.

The second chamber may be arranged such that the second chamber is not inflated by the inflator. For example, an interior of the second chamber may be fluidically isolated from the inflator, e.g. through chambers of the airbag.

The first chamber may be configured to expand against the interior trim portion of the vehicle, e.g. such that a wall of the first chamber engages the interior trim portion when the first chamber is inflated. The first chamber may thereby secure a position of the inflated airbag within the vehicle interior.

The first chamber may be configured to inflate principally in a first direction. A principal direction in which a chamber of an airbag inflates may be defined as the direction in which a dimension of the chamber increases by the greatest proportion during inflation of the airbag. The principal direction of inflation may be defined in a plane perpendicular to a lateral direction of the airbag assembly. The first chamber may be configured to extend at least partially across a surface, e.g. a rear surface (relative to the vehicle assembly) of the second chamber, when the airbag is inflated.

The airbag may further comprises one or more third chambers. The third chambers may be configured to extend across one or more surfaces of the second chamber that are substantially perpendicular to a surface of the second chamber across which the first chamber extends, when the airbag is inflated. For example, the third chambers may be configured to extend at least partially across lateral or side surface of the second chamber. The airbag may comprise two or more third chambers spaced apart from one another in a lateral direction of the airbag, e.g. along a width of the first and fourth chambers, e.g. a direction perpendicular to the direction in which the first chamber principally inflates. The third chambers may be configured to form lateral sides of the airbag.

The airbag may further comprise a fourth chamber. The fourth chamber may be configured to be inflated by the inflator. The fourth chamber may be configured to inflate principally in a direction with a component perpendicular to a principle direction of inflation of the first chamber.

The fourth chamber may be arranged such that expansion of the fourth chamber acts to increase an interior volume of the second chamber. For example, the second chamber may be formed between the first and fourth chambers. The fourth chamber may be configured such that the fourth chamber inflates principally in a second direction, e.g. in a direction parallel to the interior surface. The airbag may be configured such that the fourth chamber is in contact with at least a portion of the interior surface after the airbag has inflated.

The airbag may be configured such that the fourth chamber inflates prior to the inflation of the other chambers, during deployment of the airbag. For example, the airbag may be configured such that the first and/or third chambers are inflated by the inflator after the fourth chamber has been at least partially inflated. The airbag may be configured such that inflation gases pass through the fourth chamber to reach the first and/or third chambers. The airbag may be configured such that inflation gases are permitted to pass through the fourth chamber to the first and third chambers once the fourth chamber has at least partially inflated.

The second chamber may be disposed in a volume defined between the first and fourth chambers, e.g. between a plane parallel with the principal direction of expansion of the first chamber and a plane parallel with the principal direction of expansion of the fourth chamber.

The airbag may be substantially prism shaped when inflated, e.g. in the shape of a substantially triangular prism. The second chamber may be disposed within, e.g. inside of, the prism shape.

The first and fourth chambers may define side faces of the prism shape extending between base faces of the prism shape. The third chambers may define base faces of the prism shape. The base faces of the prism shape may be spaced apart from one another in a lateral direction of the airbag. In other words, the prism shape may extend in a lateral direction of the vehicle. The third chambers may form base faces of the prism shape. The third chambers may be arranged between the first and fourth chambers. The third chambers may inflate at the base faces of the prism shape in lateral directions of the airbag.

The airbag may be configured such that the fourth chamber is disposed between the second chamber and the interior surface of the vehicle, when the airbag is inflated. The airbag may be configured such that the second chamber is disposed between the first chamber and the interior surface of the vehicle when the airbag is inflated. In other words, the first chamber may be disposed on an opposite side of the second chamber from the interior surface, e.g. between the second chamber and a passenger compartment of the vehicle when the airbag is inflated The airbag may be formed from a single sheet of material, e.g. woven material, such as a fabric, arranged, e.g. folded, to form the one or more chambers of the airbag.

A vehicle assembly may comprise: a roof structure; an interior surface arranged adjacent to the roof structure; an interior trim portion arranged on an opposite side of the interior surface from the roof structure; and the above-mentioned airbag assembly.

The airbag may be configured to inflate relative to the interior surface and interior trim portion of the vehicle assembly, such that a passenger moving towards the interior surface during a collision first impacts the first chamber of the airbag.

To avoid unnecessary duplication of effort and repetition of text in the specification, certain features are described in relation to only one or several aspects or embodiments of the invention. However, it is to be understood that, where it is technically possible, features described in relation to any aspect or embodiment of the invention may also be used with any other aspect or embodiment of the invention.

Brief Description of the Drawings

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a schematic cross-sectional view of a vehicle assembly comprising an airbag assembly according to arrangements of the present disclosure; Figure 2 is a schematic perspective view of the vehicle assembly depicted in Figure 1; Figure 3, is a schematic top view of the vehicle assembly depicted in Figures 1 and 2; Figure 4 is a schematic cross-sectional view of a vehicle assembly comprising an airbag assembly according to another arrangement of the present disclosure; Figure 5 is a schematic perspective view of the vehicle assembly depicted in Figure 4; Figure 6 is a perspective view of the vehicle assembly depicted in Figures 4 and 5 illustrating a cut away through the airbag assembly; and Figure 7 is a schematic perspective view of a vehicle assembly comprising an airbag assembly according to another arrangement of the present disclosure.

Detailed Description

The present disclosure relates to airbag assemblies for vehicles, such as motor vehicles (e.g. cars, vans, trucks, motorcycles etc.), industrial or agricultural vehicles (e.g. tractors, forklifts, bulldozers, excavators etc), marine vessels, aircraft or any other type of vehicle.

With reference to Figures 1, 2 and 3, a vehicle assembly 2 comprises a roof structure 4, an interior trim portion 6, such as an instrument panel, and an interior surface 8, e.g. formed by a windscreen of the vehicle. The vehicle assembly 2 further comprises an airbag assembly 100 according to arrangements of the present disclosure.

The airbag assembly 100 may be mounted on or within the roof structure 4. When installed, and prior to deployment of the airbag, the airbag assembly 100 may be covered by a roof trim portion 5. The roof trim portion 5 may be configured to split or rupture and/or be displaced by the airbag as the airbag is deployed, e.g. inflates, so that the airbag can inflate away from the roof structure 4. As shown, the interior surface 8 may be disposed between the roof structure 4, e.g. the position on the roof structure at which the airbag assembly 100 is mounted, and the interior trim portion 6. In other words, the airbag assembly 100 may be mounted on an opposite side of the interior surface 8 from the interior trim portion 6.

The airbag assembly 100 comprises an airbag 110 and an inflator 120. The airbag 110 comprises an inflatable cushion which can be deployed, e.g. inflated, so as to extend over at least part of the interior surface 8, and optionally at least part of the interior trim portion 6. In this way, the inflated airbag may be positioned to cushion an impact between an occupant of the vehicle and the interior surface 8 and/or the interior trim portion 6, e.g. during a collision of the vehicle. As shown in Figure 2, the airbag 110 may have a width extending in a lateral direction of the vehicle, so as to cushion impacts between the occupant and the interior surface 8 and/or the interior trim portion 6 across a width of the vehicle assembly 2.

When the airbag 110 is inflated, the airbag 110 may be substantially prism shaped, e.g. shaped as a triangular prism. The prism shape comprises base faces 110a at opposing lateral sides of the airbag 110, and side faces 110b, 110c, 110d extending between the base faces, e.g. in a lateral direction of the airbag 110. In the arrangement shown, the side faces form a front side face 110b, a rear side face 110c and a bottom side face 110d of the airbag (relative to the vehicle assembly 2 in which the airbag is installed).

Although the airbag is described as being prism shaped within the present specification, it will be appreciated that, due to the inflatable nature of the airbag, surfaces of the airbag, e.g. forming the base and side faces of the prism shape, may be curved or non-flat, e.g. convex.

Additionally, although in the arrangement shown the airbag 110 is substantially triangular in cross-section On a plane perpendicular to the lateral direction of the airbag). In other arrangements, the airbag 110 may be any other shape in cross-section, such as square, rectangular, round, e.g. circular or oval, trapezoidal or a parallelogram. Further, the airbag 110 may be shaped according to the space available between the interior surface 8 and the interior trim portion 6, e.g. in order to substantially fill the space between the interior surface 8 and the interior trim portion 6. Hence, the cross-sectional shape of the prism may vary across the width of the airbag 110, e.g. between the base faces 110a of the prism shape.

The airbag 110 comprises a plurality of inflatable chambers 112, 114, 116, 118, described in detail below, and the inflator 120 is configured to supply inflation gases during deployment of the airbag to inflate one or more of the chambers, in order to deploy the airbag 110.

The airbag 110 may be formed from a single sheet of material, e.g. woven material, such as a fabric, arranged, e.g. folded, in order to form the chambers of the airbag. The material of the airbag may form walls of the airbag chambers. When chambers of the airbag are formed adjacent to one another, the adjoining walls of the airbag chambers may be formed by a single layer of the material forming the airbag or the wall of each adjacent chamber may be formed by individual layers of the material which are coupled to or arranged in contact with each other.

As depicted in Figures 1 and 2, the airbag 110, according to one or more arrangements of the disclosure, comprises a first chamber 112. The first chamber 112 may be arranged in fluidic communication with the inflator 120. The first chamber 112 is thereby arranged to be inflated by the inflator 120 during deployment of the airbag.

The first chamber 112 is configured such that, during deployment of the airbag, the first chamber principally inflates in a first direction Di. As shown in Figure 1, the first direction Di may have components in a forwards and downward direction relative to the vehicle assembly 2.

The direction in which an airbag chamber principally inflates, i.e. a principal direction of inflation of the airbag chamber, may be defined as the direction in which a dimension of the airbag increases by the greatest proportion during inflation of the airbag chamber.

The principal direction of inflation may be defined in a plane perpendicular to a lateral direction of the vehicle. In other words, lateral inflation of the airbag chamber may not be considered.

The first chamber 112 may be configured to expand against the interior trim portion 6.

In other words, the first chamber 112 may be configured to engage the interior trim portion 6 when the airbag is inflated. The first chamber 112 may thereby secure the position of the airbag 110 within the vehicle interior. For example, friction between the wall of the first chamber 112 and the interior trim portion 6 may act to resist movements of the airbag 110 relative to the interior trim portion, e.g. that would otherwise displace the airbag 110 from its position.

The airbag 110 further comprises a second chamber 114. The second chamber 114 may be arranged such that the second chamber is not inflated by the inflator 120 during deployment of the airbag 110. The second chamber 114 may be fluidically isolated from the inflator 120, e.g. through the chambers of the airbag.

The second chamber 114 is arranged relative to the first chamber 112 such that inflation of the first chamber 112 acts to increase an interior volume of the second chamber 114. For example, the second chamber 114 may be adjacent to the first chamber 112. The first chamber 112 may extend across a surface of the second chamber 114, e.g. a rear surface of the second chamber, when the airbag is inflated. Inflating the first chamber 112 may therefore act to tension the rear wall of the second chamber 114, increasing the interior volume of the second chamber 114.

The second chamber 114 comprises a valve 114a for allowing ambient air, e.g. from the interior of the vehicle, to be drawn into the second chamber 114 as the volume of the second chamber increases. The second chamber is therefore configured to be inflated with ambient air as the first chamber 112 is inflated by the inflator 120. The valve 114a may be a one-way valve, which prevents air that has entered the second chamber from flowing out of the second chamber via the valve 112a.

By configuring the first and second chambers 112, 114 such that inflation of the first chamber 112 causes air to be drawn into the second chamber 114, a total volume of the airbag, when fully inflated, may be greater than a volume of inflation gases produced by the inflator 120. The airbag assembly 100 may thereby be configured such the airbag 110 can be inflated to extend over a greater proportion of the interior surface 8 and/or the interior trim portion 6 of the vehicle, and/or inflated from a location that is further away from the interior surface 8 and/or interior trim portion 6, using an inflator of a particular size, e.g. configured to produce a particular volume of inflation gases, compared to an airbag inflated exclusively by gases from the inflator.

As depicted, the second chamber 114 may be arranged adjacent to the interior surface 8 of the vehicle 2, e.g. in contact with the interior surface 8, when the airbag 110 is inflated. The first chamber 112 may be arranged on an opposite side of the second chamber 114 from the interior surface. In other words, the second chamber may be positioned between the first chamber 112 and the interior surface 8 of the vehicle. The airbag 110 is thereby arranged such that a passenger 300, depicted in Figure 3, moving towards the interior surface during a collision first impacts the first chamber 112 of the airbag 110.

In some arrangements, the second chamber 114 may be configured such that a wall of the second chamber engages the interior trim portion 6 when the second chamber is inflated. The Airbag 110 may be configured such that the position of the airbag is secured within the vehicle interior due to the engagement between the wall of the second chamber 114 and the interior trim portion 6.

The airbag 110 may further comprise one or more third chambers 116. The third chambers 116 may be configured to be inflated by the inflator 120 during deployment of the airbag 110. For example, the third chamber 116 may be arranged in fluidic communication with the inflator 120.

In some arrangements, the airbag 110 may be configured such that the third chambers 116 are inflated by inflation gases that have passed through the first chamber 112 to reach the third chamber 116. The airbag 110 may be configured such that the third chambers 116 inflate, e.g. begin inflating, once the first chamber 112 has at least partially inflated, e.g. by a predetermined amount. For example, the third chamber 116 may be fluidically coupled to the first chamber 112 via an opening in the wall between the first and third chambers, which opens once the material forming the wall has at least partially unfolded, as the first chamber 112 inflates.

As shown in Figures 2 and 3, the third chambers 116 may be arranged to extend over one or more, e.g. respective, surfaces of the second chamber 114 that are substantially perpendicular to the surface of the second chamber 114 over which the first chamber 112 extends. For example, the first chamber 112 may be arranged to extend over a rear surface of the second chamber 114 (relative to the vehicle) when the airbag is inflated and the third chambers 116 may be arranged to extend across lateral or side surfaces of the second chamber 114.

The airbag 110 may comprise two or more third chambers 116 spaced apart from one another in a lateral direction of the airbag, e.g. along a width of the first and second chambers. The width of the first and second chambers may be a dimension of the chambers in a direction perpendicular to the direction in which the first chamber 112 principally inflates. As depicted, the third chambers 116 may form lateral sides of the airbag 110, e.g. base faces 110a of the airbag's prism shape. In the arrangement shown, the airbag 110 comprises two third chambers 116 for forming opposing lateral sides of the airbag 110.

The airbag 110 may be configured such that inflation of the third chambers 116 acts to increase the interior volume of the second chamber 114. For example, inflating the third chambers 116 may tension side walls of the second chamber 114 along their length, e.g. in a longitudinal direction of the airbag 110. Inflating the third chambers 116 may therefore act to increase a width of the second chamber 114, e.g. in a lateral direction of the vehicle 2, over a longitudinal length of the airbag 110. In particular, inflation of the third chambers 116 may increase the width of the second chamber 114 at a longitudinal end of the airbag positioned away from the first chamber 112.

One or more of the third chambers 116 may be configured to engage the interior trim portion 6 when the third chambers 116 have inflated, in order to secure the positon of the airbag 110 within the vehicle interior. Additionally or alternatively, one or more of the third chambers 116 may be configured to engage a further trim portion or structural component of the vehicle positioned to the side of the airbag 110, e.g. in a lateral direction of the vehicle assembly, when the airbag is inflated. For example, one or more of the third chambers may be configured to engage an A-pillar 7 of the vehicle, in order to secure the position of the airbag within the vehicle interior.

In the arrangement shown in Figures 1 to 3, the airbag 110 comprises four chambers.

More particularly, the airbag 110 depicted in Figures 1 to 3 comprises the first chamber 112, the second chamber 114 and two third chambers 116.

With reference to Figures 4 to 6, in another arrangement of the present discourse, the airbag 110 may further comprise a fourth chamber 118. The airbag 110 depicted in Figures 4 to 6 therefore comprises five chambers. In particular, the airbag 110 comprises the first chamber 112, the second chamber 114, two third chambers 116 and the fourth chamber 118.

The fourth chamber 118 may be arranged in fluidic communication with the inflator 120, so that the fourth chamber 118 is inflated by the inflator during deployment of the airbag 110.

As shown in Figure 4, the fourth chamber 118 may be configured to inflate principally in a second direction D2. The second direction D2 may be substantially parallel with the interior surface 8 of the vehicle assembly 2. In other words, the fourth chamber 118 may be configured to inflate principally along the interior surface 8, e.g. across the windscreen.

In some arrangements, the fourth chamber 118 may be configured to engage the interior trim portion 6 when the fourth chamber 118 has inflated, in order to secure the position of the airbag within the vehicle interior.

The airbag 110 may be configured such that the first and fourth chambers 112, 118 inflate substantially simultaneously. The first and fourth chambers 112, 118 may begin inflating at substantially the same time during deployment of the airbag. Alternatively, one of the first and fourth chambers 112, 118 may begin inflating before the other of the first and fourth chamber beings inflating. In the arrangement shown, the airbag 110 is configured such that the fourth chamber 118 begins inflating prior to the first chamber 112 beginning to inflate. The first chamber 112 may begin inflating once the fourth chamber 118 has at least partially or substantially completely inflated. The first chamber 112 may be inflated via an opening 118a into the fourth chamber 118, which is opened once the material forming a wall between the first and fourth chamber has partially unfolded during inflation of the fourth chamber 118.

The airbag 110 may be configured such that expansion of the fourth chamber 118 acts to increase an interior volume of the second chamber 114. The fourth chamber 118 may extend across a front surface of the second chamber 114 (relative to the vehicle) when the airbag 110 is inflated. Inflation of the fourth chamber 118 may therefore act to tension a front wall of the second chamber 114. As shown, the second chamber 114 may be formed between the first and fourth chambers 112, 118. In other words, the first and fourth chambers 112, 118 may form opposing walls of the second chamber.

As mentioned above, the airbag 110 may be substantially prism shaped. Base faces 110a of the prism shape may be formed by lateral surfaces of the airbag 110, e.g. formed by walls of the third chambers 116 of the airbag. The first and fourth chambers 112, 118 may form rear and front side faces 110c, 110b of the prism shape respectively.

The second chamber 114 may be disposed within the interior of the prism shape, e.g. between the first, third and fourth chambers 112, 116, 118. The second chamber 114 may be disposed within a volume between planes parallel with the principal directions of inflation of the first and fourth chambers, e.g. the first and second directions Di, Dz.

Further, the volume in which the second chamber 114 is disposed may be between planes or surfaces of the third chambers 116 at the opposite lateral sides of the second chamber 114. As depicted, a wall of the second chamber 114 may form the bottom side face 110d of the airbag.

As shown in Figures Sand 6, the third chambers 116 may be extend between the first and fourth chambers, e.g. across the base faces 110a of the prism shape of the airbag 110. When the airbag comprises the fourth chamber 118, the airbag 110 may be configured such that the third chambers 116 are inflated by inflation gasses from the inflator 120 passing through the fourth chamber 118.

The airbag 110 may be configured such that the third chambers 116 begin inflating after the fourth chamber 118 has been at least partially or substantially completely inflated. For example, the third chambers 116 may be inflated via one or more openings 118b formed in a wall between the fourth and third chambers, which open between the chambers once the material forming the wall has at least partially unfolded during inflation of the fourth chamber 118. The third chambers 116 may inflate at the base faces 110a of the prism in lateral directions of the vehicle.

As described above, the fourth chamber 118 may be configured to inflate, or begin inflating, before the first chamber 112 begins inflating. The fourth chamber 118 may therefore be the first chamber to inflate or begin inflating during deployment of the airbag.

With reference to Figure 7, in some arrangements, the airbag 110 may further comprise a laterally extending chamber 700 configured to extend laterally from the other chambers of the airbag into a more central area of the vehicle interior. The laterally extending chamber 700 may thereby be arranged to cushion an impact between a passenger and a more central portion of the interior surface 8 and/or the interior trim portion 6, e.g. during a collision of the vehicle. In some arrangements, the laterally extending chamber 700 may be arranged to cushion an impact between a passenger seated in a central seat of the motor vehicle and the interior surface 8 and/or the interior trim portion 6.

As shown, the laterally extending chamber 700 may extend laterally from a side of the airbag formed by the third chamber 116, e.g. from the third chamber. The airbag 110 may comprise an opening 702 between the first chamber 112 or the third chamber 118, and the laterally extending chamber 700, e.g. formed in a wall of the airbag between the chambers. The laterally extending chamber 700 may be inflated by inflation gases passing through the first chamber 112 and/or the third chamber 116 to reach the laterally extending chamber 700 through the opening 702. In some arrangements, the airbag may be configured, e.g. by the position and/or configuration of the opening 702, such that the laterally extending chamber 700 begins inflating, once the first and/or third chambers 112, 116 have at least partially inflated or substantially completely inflated.

The following additional, numbered statements of invention are also included within the specification and form part of the present disclosure: Statement 1. An airbag assembly for a vehicle, the assembly comprising: an inflator; and an airbag configured to be deployed from a roof structure of the vehicle to inflate over an interior surface of the vehicle in order to cushion impacts between an occupant of the vehicle and the interior surface during a collision of the vehicle, wherein the airbag comprises: a first chamber configured to extend from the roof structure across the interior surface of the vehicle when the first chamber is inflated; and a second chamber, the second chamber arranged relative to the first chamber such that inflation of the first chamber acts to increase an interior volume of the second chamber, wherein the second chamber comprises a valve for allowing ambient air to be drawn into the second chamber as the volume of the second chamber increases.

Statement 2. The airbag assembly of statement 1, wherein the first chamber is configured to expand against an interior trim portion of the motor vehicle and thereby secure a position of the inflated airbag within the vehicle interior.

Statement 3. The airbag assembly of statement 1 or 2, wherein the airbag further comprises one or more third chambers configured to extend across one or more surfaces of the second chamber that are substantially perpendicular to a surface of the second chamber across which the first chamber extends, when the airbag is inflated.

Statement 4. The airbag assembly of statement 3, wherein the airbag comprises two or more third chambers spaced apart from one another in a lateral direction of the airbag.

Statement 5. The airbag assembly of any of statements 1 to 4, wherein the airbag further comprises a fourth chamber inflated by the inflator, wherein the fourth chamber is configured to inflate principally in a direction with a component perpendicular to a principle direction of inflation of the first chamber.

Statement 6. The airbag assembly of statement 5, wherein the fourth chamber is arranged such that expansion of the fourth chamber acts to increase an interior volume of the second chamber.

Statement 7. The airbag assembly of statement 5 or 6, wherein the fourth chamber is configured such that the fourth chamber inflates principally in a direction parallel to a surface of the interior surface.

Statement 8. The airbag assembly of any of statements 5 to 7, wherein the airbag assembly is configured such that the fourth chamber inflates prior to the other chambers during deployment of the airbag.

Statement 9. The airbag assembly of any of statements 5 to 8, wherein the second chamber is disposed in a volume defined between the first and fourth chambers.

Statement 10. The airbag assembly of any of statements 5 to 9, wherein the first and fourth chambers inflate to define sides of a prism shape, wherein the second chamber is disposed at least partially within the prism shape.

Statement 11. The airbag assembly of any of statements 5 to 11, wherein the airbag is configured such that fourth chamber is disposed between the second chamber and the interior surface, when the airbag is inflated.

Statement 12. The airbag assembly of statement any of statements 4 to 11 when depending on statement 3, wherein the third chambers inflates between the first and fourth chambers.

Statement 13. The airbag assembly of statement 11 and 12, wherein the third chambers define base faces of the prism shape.

Statement 14. The airbag assembly of any of the preceding statements, wherein the airbag is configured such that the second chamber is disposed between the first chamber and the interior surface of the vehicle when the airbag is inflated.

Statement 15. The airbag assembly of any of the preceding statements wherein the airbag is formed from a single sheet of material arranged to form the one or more chambers of the airbag.

Statement 16. A vehicle assembly comprising:

a roof structure; an interior surface arranged adjacent to the roof structure; an interior trim portion arranged on an opposite side of the interior surface from the roof structure; and the airbag assembly of any of the preceding statements.

Statement 17. The vehicle assembly of statement 16, wherein the airbag is configured to inflate relative to the interior surface and interior trim portion of the vehicle assembly, such that a passenger moving towards the interior surface during a collision first impacts the first chamber of the airbag.

It will be appreciated by those skilled in the art that although the invention has been described by way of example, with reference to one or more exemplary examples, it is not limited to the disclosed examples and that alternative examples could be constructed without departing from the scope of the invention as defined by the appended claims.

Claims

Claims 1. An airbag assembly for a vehicle, the assembly comprising: an inflator; and an airbag configured to be deployed from a roof structure of the vehicle to inflate over an interior surface of the vehicle in order to cushion impacts between an occupant of the vehicle and the interior surface during a collision of the vehicle, wherein the airbag comprises: a first chamber configured to extend from the roof structure across the interior surface of the vehicle when the first chamber is inflated; and a second chamber, the second chamber arranged relative to the first chamber such that inflation of the first chamber acts to increase an interior volume of the second chamber, wherein the second chamber comprises a valve for allowing ambient air to be drawn into the second chamber as the volume of the second chamber increases.
2. The airbag assembly of claim 1, wherein the first chamber is configured to expand against an interior trim portion of the motor vehicle and thereby secure a position of the inflated airbag within the vehicle interior.
3. The airbag assembly of claim 1 or 2, wherein the airbag further comprises one or more third chambers configured to extend across one or more surfaces of the second chamber that are substantially perpendicular to a surface of the second chamber across which the first chamber extends, when the airbag is inflated.
4. The airbag assembly of claim 3, wherein the airbag comprises two or more third chambers spaced apart from one another in a lateral direction of the airbag.
5. The airbag assembly of any of claims 1 to 4, wherein the airbag further comprises a fourth chamber inflated by the inflator, wherein the fourth chamber is configured to inflate principally in a direction with a component perpendicular to a principle direction of inflation of the first chamber.
6. The airbag assembly of claim 5, wherein the fourth chamber is arranged such that expansion of the fourth chamber acts to increase an interior volume of the second chamber.
7. The airbag assembly of claim 5 or 6, wherein the fourth chamber is configured such that the fourth chamber inflates principally in a direction parallel to a surface of the interior surface.
8. The airbag assembly of any of claims 5 to 7, wherein the airbag assembly is configured such that the fourth chamber inflates prior to the other chambers during deployment of the airbag
9. The airbag assembly of any of claims 5 to 8, wherein the second chamber is disposed in a volume defined between the first and fourth chambers.
10. The airbag assembly of any of claims 5 to 9, wherein the first and fourth chambers inflate to define sides of a prism shape, wherein the second chamber is disposed at least partially within the prism shape.
11. The airbag assembly of any of claims 5 to 11, wherein the airbag is configured such that fourth chamber is disposed between the second chamber and the interior surface, when the airbag is inflated.
12. The airbag assembly of claim any of claims 4 to 11 when depending on claim 3, wherein the third chambers inflates between the first and fourth chambers.
13. The airbag assembly of claim 11 and 12, wherein the third chambers define base faces of the prism shape.
14. The airbag assembly of any of the preceding claims, wherein the airbag is configured such that the second chamber is disposed between the first chamber and the interior surface of the vehicle when the airbag is inflated.
15. The airbag assembly of any of the preceding claims wherein the airbag is formed from a single sheet of material arranged to form the one or more chambers of the airbag.
16. A vehicle assembly comprising: a roof structure; an interior surface arranged adjacent to the roof structure; an interior trim portion arranged on an opposite side of the interior surface from the roof structure; and the airbag assembly of any of the preceding claims.
17. The vehicle assembly of claim 16, wherein the airbag is configured to inflate relative to the interior surface and interior trim portion of the vehicle assembly, such that a passenger moving towards the interior surface during a collision first impacts the first chamber of the airbag.