Airbags

Abstract

To provide an inflatable airbag that causes the airbag to curve when inflated. The airbag (1) is formed from fabric layers (2, 3) arranged to define an inflatable chamber (7) between the layers (2, 3). The fabric layers (2, 3) include threads (4), and the layers (2, 3) are interconnected by tether threads (8) that extend between the layers (2, 3) within the inflatable chamber (7). Each tether thread (8) participates in the structure of layer (2) at a first connection region (9a) and participates in the structure of layer (3) at a second connection region (9b). The first connection region (9a) is wider than the second connection region (9b) in the length direction of each tether thread (8), and the second connection region (9b) is offset so as not to face either of the first connection regions (9a) across the inflatable chamber (7). Each tether thread (8) induces a curvature in the airbag (1) when the inflatable chamber (7) of the airbag (1) is inflated.

Description

[Technical field]

[0001] The present invention relates to airbags configured to be inflated by a source of inflation gas, and more particularly to inflatable airbags having an integral tether arrangement that induces curvature in the airbag upon inflation. [Background technology]

[0002] It is well known, and currently quite common, to provide airbags in motor vehicles so that in the event of an accident the airbag inflates to assume an inflated position between the head or body of the vehicle occupant and the structure of the vehicle to protect the occupant by reducing the likelihood of a harmful impact between the head or body of the occupant and the structure of the vehicle. It is also becoming common to provide airbags external to the motor vehicle to provide similar protection to vulnerable road users, such as pedestrians or cyclists, by inflating the airbag when a collision with the vehicle is detected or predicted to cushion the impact of the vehicle in the event of an accident.

[0003] Additionally, there have been some proposals to provide airbags as part of personal protection equipment configured to be worn by people performing high-risk tasks. For example, a personal fall protection system may include one or more airbags configured to inflate upon detecting that the wearer may fall, thereby assuming an inflated position against a portion of the wearer's body, such as the hip area, to provide protection against injury resulting from a fall.

[0004] To ensure the provision of effective protection, it is often desirable to provide an airbag that is configured to assume a somewhat curved or bent shape when inflated. An example here is a side impact airbag that is provided within the passenger compartment of a motor vehicle and configured to assume an inflated position between the vehicle occupant and the vehicle's side structure to protect the occupant in the event of a side impact. For such side impact airbags, it may be advantageous for the airbag to assume an inflated shape that is somewhat concave toward the occupant in order to "trap" the occupant's head and / or torso, thereby reducing the likelihood that the occupant's head or torso will slide forward or backward across the airbag under inertial forces and fall out of protective contact with the airbag. So-called knee airbags are another example of airbags where a curved inflated shape may be advantageous. Knee airbags are typically installed low in the footwell of a motor vehicle (e.g., below the vehicle's dashboard) and may be configured to curve upwards in the inflated configuration and extend around the dashboard from the installed position in order to provide sufficient protection for the occupant's knees.

[0005] So-called inflatable curtain (IC) airbags may also be advantageously configured to assume a somewhat curved shape upon inflation to improve their protective performance. Inflatable curtain airbags are provided in motor vehicles in positions such that in the event of an accident involving a side impact or rollover accident, the airbag inflates to be disposed between the side of the vehicle and the head of the vehicle occupant to protect the occupant's head from contacting or passing through the vehicle's side window. Typically, inflatable curtain airbags are configured to extend over the entire side window area of ​​the motor vehicle, and it has been found that a degree of curvature induced in the inflated shape of such an airbag can be effective in increasing the area of ​​coverage of the airbag, for example in the A-pillar area of ​​the motor vehicle where the side window meets the rearward sloping frame of the windshield.

[0006] A personal fall protection device represents another example of an airbag whose protective performance can be improved by having a somewhat curved inflated shape. For example, a hip protector airbag should be configured to wrap around the user as it deploys, rather than deploying away from the user, in order to provide optimal protection. Additionally, a hip protector airbag represents an example of an airbag whose performance can be further optimized by having a configuration that induces two types of curvature in its inflated configuration: a first curvature about the user's vertical axis (so that the airbag extends around the sides of the wearer's hips upon deployment), and a second curvature about the user's sagittal axis (so that the airbag extends under the user's hips and buttocks, especially when in a seated position).

[0007] As one skilled in the art will readily appreciate, there are many other examples of airbags where bi-directional bending or two types of curvature upon deployment is desirable, such as, for example, personal fall protection clothing in the form of vests, pants, helmets, shorts, trousers, etc.

[0008] It is also believed that a convenient method of achieving a curved shape upon inflation of an airbag can facilitate the provision of airbags for a variety of different applications. For example, an airbag configured to curve in multiple different regions can be configured to achieve a series of staircase shapes upon inflation.

[0009] The present invention has been devised in consideration of the above. Summary of the Invention

[0010] According to a first aspect, an airbag configured to be inflated by a gas source is provided, the airbag being formed from first and second fabric layers arranged in a superimposed manner to define between the layers an inflatable chamber for receiving inflation gas, each fabric layer having a structure including at least one thread, the two layers being interconnected by at least one tether thread extending between the layers within the inflatable chamber. The or each tether thread participates in the structure of the first layer in a number of first connection regions and participates in the structure of the second layer in a number of second connection regions. Each of the first connection regions is wider than each of the second connection regions in a length direction of the or each tether thread, and the second connection regions are offset relative to the first connection regions such that the second connection regions do not face any of the first connection regions across the inflatable chamber. The at least one tether thread serves to induce a curvature in the airbag when the inflatable chamber of the airbag is inflated.

[0011] The fabric layers may be woven, in which case the structure of each fabric layer is a weave that includes a plurality of parallel warp yarns and a plurality of parallel weft yarns. For example, the fabric layers may have a plain weave structure, but may alternatively have other weave configurations.

[0012] Alternatively, it is contemplated that the fabric layer may be knitted, in which case the structure of the fabric layer is a knit that includes at least one yarn that forms interlocking loops. For example, the knit of the fabric layer may be a so-called weft knit that includes a single yarn. Alternatively, the knit of the fabric layer may be a so-called warp knit that includes loops formed from separate yarns.

[0013] Conveniently, the first connection regions are spaced apart from one another over at least a portion of the first layer, and the second connection regions are spaced apart from one another over at least an opposing portion of the second layer.

[0014] The location of the second fabric layer of at least one of the second connection regions may be sandwiched between the locations of the first fabric layer of two adjacent first connection regions.

[0015] The or each tether yarn may be positioned such that it does not participate in the structure of the first layer between the second connection regions and does not extend between any of the second connection regions.

[0016] Advantageously, at least one of the first connection regions may include a plurality of spaced apart connection sub-regions in which the or each tether yarn participates in the structure of the first layer and in which the or each tether yarn extends between the connection sub-regions of the or each first connection region without participating in the structure of either the first layer or the second layer between the connection sub-regions.

[0017] Optionally, each such fabric layer is woven and has a weave including a plurality of generally parallel yarns.

[0018] Advantageously, the or each tether yarn is interwoven with yarns of the first layer in each said first connection region and with yarns of the second layer in each said second connection region.

[0019] Advantageously, the or each tether yarn is interwoven with any yarn of that layer only in that connection region.

[0020] The or each tether yarn may interweave with yarns of the first layer only in that connection sub-region and may interweave with yarns of the second layer only in that second connection region.

[0021] The airbag may include a plurality of such tether yarns, the tether yarns extending generally parallel to one another and generally perpendicular to the generally parallel yarns of the weave of the first and second layers.

[0022] Optionally, the generally parallel yarns of each fabric layer are warp yarns, and each fabric layer further comprises a plurality of generally parallel weft yarns, the or each tether yarn extending generally parallel to the weft yarns.

[0023] The generally parallel yarns of each fabric layer may be warp yarns, and each fabric layer may further include a plurality of generally parallel weft yarns. The inflatable airbag may include a plurality of such tether yarns, the tether yarns extending generally parallel to the weft yarns of the fabric layers.

[0024] Alternatively, it is envisioned that the or each tether yarn may extend generally parallel to the warp yarns.

[0025] A number of tether yarns arranged in side-by-side relationship with one another may be provided, e.g., the tether yarns are distributed between the weft yarns of two fabric layers and extend generally parallel to the weft yarns, perpendicular to the warp yarns, or vice versa, thereby collectively defining a tether having a width extending a distance along the warp direction (or weft direction) of the fabric. Indeed, in some embodiments, it is envisioned that the tether yarns may be provided in a third fabric layer woven from a third set of warp yarns and tether yarns, with the tether yarns defining the weft yarns of the third fabric layer. Alternatively, the tether yarns may be provided in a third layer of fabric woven in such a manner that the tether yarns define the warp yarns of the third layer.

[0026] Optionally, each said connection region is generally elongate, and said first and second connection regions extend generally parallel to each other and across respective fabric layers of the airbag so as to transverse a plurality of weft (or warp) yarns of the fabric layers.

[0027] Also optionally, the first and second connection regions may traverse the plurality of weft yarns at an oblique angle relative to the weft yarns and may traverse the plurality of warp yarns at an oblique angle relative to the warp yarns.

[0028] The airbag is optionally a one-piece woven airbag including at least one integrally woven seam defined by an area where yarns of the weave of one of said layers interweave with yarns of the weave of the other of said layers, and the or each tether yarn may be integrally woven into the weave of said layers in said connection area.

[0029] According to a second aspect, an airbag configured to be inflated by a gas source is provided, the airbag being formed from first and second fabric layers arranged in a superimposed relationship to define an inflatable chamber between the layers for receiving inflation gas, each fabric layer having a structure including at least one thread, the two layers being interconnected by at least one tether yarn extending between the layers within the inflatable chamber. At least some of the tether yarns participate in the structure of the layer in a first group of connection regions including a plurality of first connection regions where the tether yarn participates in the structure of the first layer and a plurality of second connection regions where the tether yarn participates in the structure of the second layer. At least some of the tether yarns participate in the structure of the layer in a second group of connection regions including a plurality of first connection regions where the tether yarn participates in the structure of the first layer and a plurality of second connection regions where the tether yarn participates in the structure of the second layer. Within each group of connection regions, each of the first connection regions is wider than each of the second connection regions in the length direction of the tether yarn. The second connection regions are offset relative to the first connection regions such that the second connection regions are not across the inflatable chamber from the first connection regions. The first and second connection regions within each group are elongated and extend generally parallel to one another and across the respective layers of the airbag, with the first group of connection regions being non-parallel to the second group of connection regions. The tether yarns are responsible for inducing a first curvature in the airbag via the first group of connection regions and for inducing a second curvature in the airbag via the second group of connection regions when the inflatable chamber is inflated.

[0030] The airbag of the second embodiment, like the first embodiment, may be woven or knitted.

[0031] Advantageously, each connection region extends along a respective extension axis, at least some of the connection regions of one of the groups extending transversely to the extension axis along which at least some of the connection regions of the other group extend.

[0032] The two groups of connection regions may be immediately adjacent to each other, for example a first group of connection regions may be provided immediately adjacent to a second group of connection regions.

[0033] Optionally, the connection regions of the first group extend at an oblique angle to the extension of the connection regions of the second group.

[0034] If the fabric layers are woven, the connection regions of the first and second groups may extend at an oblique angle to both the warp and weft yarns of the two fabric layers.

[0035] Conveniently, at least one of said groups of connection areas comprises a first set of said first and second connection areas and a second set of first and second connection areas, each first connection area of ​​said first set extending collinearly to a respective first connection area of ​​said second set and each second connection area of ​​said first set extending collinearly to a respective second connection area of ​​said second set, said first and second sets of connection areas being separated from each other by a bend seam interconnecting the first and second fabric layers. The bend seam may thus be configured to propagate a curvature of the airbag caused by the group of connection areas in which it is provided.

[0036] Optionally, the bend seam is substantially straight and extends generally perpendicular to the extension of the connection regions of the first and second sets of connection regions in a group.

[0037] When the fabric layer is woven, the tether yarns may be arranged to extend generally parallel to one another and to the weft yarns of the fabric layer, or it is envisioned that the tether yarns may extend generally parallel to the warp yarns.

[0038] Advantageously, within each said group of connection regions, the first connection regions are spaced apart from one another across a portion of the first layer and the second connection regions are spaced apart from one another across an opposing portion of the second layer.

[0039] Advantageously, within each said group of connection regions, the tether thread does not extend between any of said second connection regions without participating in the structure of the first layer between said second connection regions.

[0040] Optionally, within at least one of the groups of connection regions, at least one of the first connection regions includes a plurality of spaced apart connection sub-regions in which the tether yarn participates in the structure of the first layer and the tether yarn extends between the connection sub-regions without participating in the structure of either the first layer or the second layer between the connection sub-regions.

[0041] Optionally, each such fabric layer is woven and has a weave including a plurality of generally parallel yarns.

[0042] The tether yarns may be interwoven with yarns of the first layer in each such first connection region, and the tether yarns may be interwoven with yarns of the second layer in each such second connection region.

[0043] Advantageously, the tether yarns interweave with yarns of the first layer only in said connection sub-region and with yarns of the second layer only in said second connection region.

[0044] If the fabric layers are woven, the connection regions of the first and second groups may extend at an oblique angle to both the warp and weft yarns of the two fabric layers.

[0045] Optionally, the airbag of the second embodiment is a one-piece woven airbag including at least one integrally woven seam defined by an area where yarns of the weave of one of said layers interweave with yarns of the weave of the other of said layers, and said tether yarns are integrally woven into the weave of said layers within said connection area. Advantageously, said at least one integrally woven seam can include a bend seam as previously described.

[0046] While embodiments are described herein and illustrated in the accompanying drawings in which the tether yarns participate in the weave of the constituent fabric layers by passing between or partially around (e.g., by interweaving with) the warp yarns of the woven airbag, it is proposed that in other embodiments the tether yarns may instead be arranged to pass between or at least partially around (e.g., by interweaving with) the weft yarns of the airbag. Thus, in such embodiments, it will be understood that the tether yarns are distributed between the warp yarns of the constituent fabric layers, rather than between the weft yarns as described with reference to certain embodiments disclosed herein.

[0047] The fabric layers of the airbag, and optionally the internal tethers defined by the tether yarns, may be provided with a surface coating or film. In the case of the main constituent fabric layers of the airbag, the coating or film may be applied to either their inner surface, their outer surface, or both. For example, it is proposed that a heat-resistant coating or film may be applied to the fabric layers and / or the tethers to protect the fabric and yarns from high temperatures that may occur during inflation due to the high temperature of the inflation gas generated by the inflator. Alternatively or in addition, the coating or film may provide a sealing function that is effective to prevent or reduce leakage of inflation gas between the yarns of the airbag during inflation. This may be particularly advantageous around the connection areas of two fabric layers where the tether yarns participate in the structure (e.g., weave) of the fabric layers, since when the tether yarns are under tension during airbag inflation, they may tend to pull the warp or weft yarns of the fabric layers away from each other, thereby opening up small gaps through which the inflation gas may leak.

[0048] The present invention includes combinations of the described embodiments and preferred features except where such combinations are expressly not permitted or are explicitly avoided.

[0049] Those skilled in the art will understand that, unless mutually exclusive, a feature or parameter described in connection with any one of the above embodiments may be applied to any other embodiment. Furthermore, unless mutually exclusive, any feature or parameter described herein may be applied to any embodiment and / or may be combined with any other feature or parameter described herein. [Brief description of the drawings]

[0050] In order that the invention may be more readily understood and further features thereof may be appreciated, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a perspective view of a cross section through a portion of the airbag showing the internal tether arrangement. [Diagram 2] 1 is a schematic cross-sectional view of a conventional internal tether arrangement within an airbag. [Diagram 3] 1 is a schematic cross-sectional view of another conventional internal tether arrangement within an airbag. [Figure 4] 1 is a schematic cross-sectional view of an internal tether arrangement provided within an airbag according to one aspect of the present invention. [Diagram 5] 1 is a schematic cross-sectional view illustrating one way in which a tether yarn may participate in the weave of an airbag layer. [Figure 6] 11 is a schematic cross-sectional view illustrating another way in which a tether yarn may participate in the weave of an airbag layer. [Figure 7] FIG. 1 is a schematic diagram of an airbag showing multiple connection areas where tether yarns may participate in the weave of the layers of the airbag. [Figure 8] 5 is a schematic cross-sectional view similar to FIG. 4, but showing the tether arrangement that causes the airbag to curve upon inflation. [Figure 9] 1 is a cross-sectional view of an inflated airbag showing the curvature induced in the airbag upon inflation. [Figure 10] 1 is a perspective view of an uninflated airbag according to one aspect of the present invention. [Figure 11]FIG. 11 is another perspective view of the airbag shown in FIG. 10, but showing the airbag in an inflated and curved configuration. [Figure 12] 1 is a schematic diagram of a front view of a pair of particular airbags inflated about a person's hip area to protect the person's hip area; [Figure 13] 13 is a schematic diagram of an underneath view of the pair of airbags of FIG. 12 inflated about a person's hip area. [Figure 14] 14 is a schematic view similar to FIG. 12, but showing a pair of specific airbags of an alternative configuration to those of FIGS. 12 and 13. [Figure 15] FIG. 15 is a schematic view from below of the pair of airbags of FIG. 14 inflated around a person's hip area. [Figure 16] 1 is a schematic plan view of a one-piece woven web including opposing layers of woven fabric having a pair of airbags formed therein in accordance with one aspect of the present invention. [Figure 17] FIG. 17 is a top plan view showing a pair of airbags obtained from the web shown in FIG. [Figure 18] FIG. 18 is a schematic plan view, seen from above, of one of the airbags of FIG. 17. [Figure 19] 18 is a schematic front view similar to FIGS. 12 and 14, but showing instead the airbag of FIG. 17 inflated around a person's hip region to protect the person's hip region. FIG. [Figure 20] 18 is a schematic view from below similar to FIGS. 13 and 15, but instead showing the airbag of FIG. 17 inflated around a person's hip region to protect the person's hip region. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] Aspects and embodiments of the present invention will now be described with reference to the accompanying drawings, and further aspects and embodiments will be apparent to those skilled in the art.

[0052] Referring initially to Figure 1, there is shown a region of an airbag 1 adapted to be inflated by a gas source. As will be appreciated, and as is conventional, the airbag 1 is formed from first (upper) and second (lower) layers of fabric 2, 3, each of which is woven from warp threads 4 and weft threads 5, and thus has a structure in the form of a woven fabric. However, it will be appreciated that the invention may alternatively be applied to airbags in which the fabric layers are knitted layers, in which case the layers have a structure in the form of a knitted fabric including at least one yarn.

[0053] The two layers of fabric 2,3 are arranged one over the other and interconnected around their peripheral edges by a peripheral seam 6 (only a portion of which is shown in FIG. 1 ), thereby defining, in a known manner, an inflatable chamber 7 between the layers 2,3 for receiving inflation gas from an inflator (not shown), such as a gas generator. The airbag 1 may be woven by a so-called one-piece weaving technique, in which the two layers 2,3 are woven simultaneously and the yarns 4,5 of the two layers 2,3 are interwoven in predetermined areas to form the peripheral seam 6 (and optionally other seams and / or other interconnections not shown in FIG. 1 ) as an integral structural feature of the airbag 1.

[0054] An exemplary one-piece weaving technique for fabricating airbags is described in more detail in WO199009295(A).

[0055] The airbag 1 shown in Figure 1 has a known configuration of an integrally woven internal tether arrangement. As shown generally in Figure 1 and in more detail in Figure 2, additional tether yarns 8 are also woven into the weave of the fabric at selected locations throughout the layers 2, 3. The tether yarns 8 are woven to extend substantially parallel to the weft yarns 5 of the fabric (and thus substantially perpendicular to the warp yarns 4) and pass over and under successive warp yarns 4 in predetermined connection regions 9 to participate in the weave of the layers 2, 3 at the connection regions 9. The tether yarns 8 may have a different configuration than the warp and weft yarns 4 and 5 of the fabric layers 2, 3, as described in EP 2407353(A).

[0056] At the edge of each connection region 9, the tether threads 8 exit the respective fabric layer 2, 3 in which they are woven and extend towards the opposing layer 3, 2. In the particular arrangement shown in Figs. 1 and 2, the tether threads 8 each extend into the opposing fabric layer 3, 2 and are integrally woven therewith at another connection region 9. As can be seen in Fig. 2, the tether threads 8 are arranged to cross one another and exit one fabric layer 2, 3 and extend into the other fabric layer 3, 2. The tether threads 9 thus cooperate to define a tether 10, which serves to interconnect the two fabric layers 2, 3 within and across the inflatable chamber 7 of the airbag 1. As shown in Fig. 2, each tether 10 may be defined by multiple tether threads 8, in this case by two pairs of crossing tether threads 8.

[0057] 3 shows a larger extent of the two fabric layers 2, 3 from which it can be seen that the tether yarns 8 each participate in the structure (i.e., weave) of the two layers 2, 3 at multiple connection regions 9. In the prior art arrangement shown in FIG. 3, each layer 2, 3 has multiple spaced connection regions 9 in which the tether yarns are interwoven with the fabric of the respective layer 2, 3. It is further noted that each connection region 9 of the first layer 2 is disposed opposite a respective connection region 9 of the second layer 3, sandwiching an inflatable chamber 7 defined between the two layers 2, 3.

[0058] 3 shows the two fabric layers 2, 3 disposed generally adjacent to one another as they are in the uninflated state of the airbag 1. As will be appreciated by those skilled in the art, when the airbag 1 is inflated by injection of inflation gas into the inflatable chamber 7, the first layer 2 and second layer 3 of the airbag 1 begin to move apart as the airbag begins to achieve an inflatable configuration. During inflation, the tether thread 8 is pulled tight, thereby cooperating to resist further movement of the two layers 2, 3 away from one another as the airbag 1 is inflated, which may play an important role in controlling the inflation depth or thickness of the airbag 1 in certain airbag installations, such as those involving the use of the airbag 1 in a secure arrangement within a motor vehicle.

[0059] Referring now to Figure 4, there is shown a tether arrangement for an airbag 1 according to one embodiment of the present invention, which tether arrangement offers significant advantages over the conventional arrangements described above and shown in particular in Figures 2 and 3. As will be apparent to those skilled in the art, the tether arrangement shown in Figure 4 shares certain features and similarities with the conventional arrangements shown in Figures 2 and 3 and therefore will not be described in detail again. Nevertheless, it is noted that the airbag 1 according to the present invention may also be formed by one-piece weaving techniques such as those disclosed in WO199009295(A) and may incorporate tether yarns 8 having a different configuration to the warp yarns 4 and weft yarns 5 of the fabric layers 2, 3 of the airbag as described in EP2407353(A).

[0060] As can be observed, in the arrangement shown in FIG. 4, the tether yarns 8 do not cross each other when they leave the weave of one fabric layer and enter the weave of the other fabric layer. In contrast to the conventional arrangements shown in FIG. 2 and FIG. 3, the tether yarns 8 instead follow substantially similar paths through the weave of the two layers 2, 3, respectively. In particular, it is observed that the tether yarns 8 follow paths that respectively participate in the weave of the first layer 2 in a plurality of first connection regions 9a (e.g., by interweaving with the warp yarns 4 of the first layer 2) and in a plurality of second connection regions 9b (e.g., by interweaving with the warp yarns 4 of the first layer 2) and in a plurality of second connection regions 9b (e.g., by interweaving with the warp yarns 4 of the first layer 2), respectively. The tether yarns 8 interweave with the yarns of the fabric layers 2, 3 only in the connection regions 9a, 9b. It is envisaged that the warp threads 8 are integrally woven into the weave of the two fabric layers 2, 3 in the connection regions 9a, 9b during a one-piece weaving process in which the fabric layers 2, 3 are themselves woven simultaneously.

[0061] As shown in FIG. 4, in the particular arrangement shown, each first connection region 9a actually comprises a pair of connection sub-regions 9a' spaced apart from each other in the weft direction 11 of the first fabric layer 2. It is observed that within each first connection region 9a, the tether yarn 8 is interwoven with the yarns of the first fabric layer 2 only in the connection sub-regions 9a'. Thus, the tether yarn 8 passes between the connection sub-regions 9a' in each first connection region 9a without participating in the weave structure of the first layer 2 (or indeed the second layer 3). Between the connection sub-regions 9a', the tether yarn 8 simply passes adjacent to the first fabric layer 2 in the inflatable chamber 7 of the airbag. However, it should be understood that in other embodiments, the tether yarn 8 may be interwoven with the yarns of the first fabric layer 2 over the entire width (in the weft direction 11) of each first connection region 9a, in which case there is no separate sub-region 9a' as described above.

[0062] The first connection regions 9a themselves are also spaced apart from one another in the weft direction 11 of the first textile layer 2, and indeed the second connection regions 9b are also spaced apart from one another in the weft direction 11 of the second textile layer 3. Importantly, it will be observed that the tether yarns 8 are involved in the weave of the textile layers 2, 3 with each first connection region 9a being more widely spaced apart in the length direction of the tether yarns 8 (i.e. corresponding to the weft direction 11 in this embodiment) than each of the second connection regions 9b. It will also be observed that there are a greater number of connection sub-regions 9a' (i.e. where the tether yarns 8 are actually involved in the weave of the first layer 2) than there are second connection regions 9b (i.e. where the tether yarns 8 are involved in the weave of the second layer 3). It is further observed that the first connection area 9a and the second connection area 9b are offset relative to each other in the weft direction 11 of the textile layers 2, 3, such that the first connection area 9a of the first textile layer 2 does not face any of the second connection areas 9b of the second textile layer 3 across the inflatable chamber 7, and vice versa. This arrangement is such that each second connection area 9b is sandwiched between two adjacent first connection areas 9a in the weft direction 11.

[0063] FIG. 5 shows one way in which the tether yarn 8 may participate in the weave of either of the fabric layers 2, 3, respectively. For convenience, FIG. 5 shows a single tether yarn 8 participating in the weave of the first fabric layer 2 in a sub-region 9a' of the first connection region 9a, but it should be understood that the tether yarn 8 may participate in the weave of the second fabric layer 3 in the second connection region 9b in substantially the same manner. As can be observed, the tether yarn 8 passes between two adjacent warp yarns 4 of the first fabric layer 2 from within the inflatable chamber 7 of the airbag, and then weaves between adjacent warp yarns 4 of the fabric layer 2 in a plain weave (i.e., passes over / under every other warp yarn 4) in the sub-region 9a' before passing out of the fabric layer 2 at the side of the inflatable chamber 7 (and then extends towards the adjacent sub-region 9a' or towards the second fabric layer 3, not shown in FIG. 5). The sub-region 9a' shown in Figure 5 includes a group of five adjacent warp yarns 4 between which the tether yarns 8 are interwoven. In other configurations, it is envisaged that the sub-region 9a' or second connection region 9b may include more or fewer, e.g., 3, 7, 9, 11, 13, or indeed any convenient odd number of warp yarns 4, such that the tether yarns 8 enter and exit the sub-region 9a' or second connection region 9b from the side of the inflatable chamber 7. In arrangements in which the tether yarns 8 are interwoven with yarns of the first fabric layer 2 across the entire width (in the weft direction 11) of the first connection region 9a, it is proposed that the first connection region 9a may include more than five, e.g., 7, 9, 11, 13, or indeed any convenient odd number of adjacent warp yarns 4.

[0064] FIG. 6 illustrates another manner in which the tether yarn 8 may participate in the weave of either of the fabric layers 2, 3. For convenience, FIG. 6 illustrates a single tether yarn 8 participating in the weave of the first fabric layer 2 in the first connection region 9a, but it should be understood that the tether yarn 8 may participate in the weave of the second fabric layer 3 in the second connection region 9b in substantially the same manner. In this arrangement, the first connection region 9a includes a first portion 9a1, a second portion 9a2, and a third portion 9a3. Each portion 9a of the connection region 9a 1~3 includes a respective number of warp yarns 4 of the fabric layer 2 and an arrangement in which the tether yarns 8 pass between or over the warp yarns 4.

[0065] In the first portion 9a1 of the connection region 9a, the tether yarn 8 passes between two adjacent warp yarns 4a, 4b from the side directed toward the inside of the fabric layer 2 defining the inflatable chamber 7 to the outside of the fabric layer 2, and then passes partially around two adjacent warp yarns 4b, 4c. When the tether yarn 8 passes partially around two or more adjacent warp yarns in this manner, the tether is said to "float" above the adjacent warp yarns 6. In other configurations, the tether yarn 8 may float above three or more adjacent warp yarns 4 in the first portion 9a1 of the connection region 9a. For example, the tether yarn 8 may float above three adjacent warp yarns 4 in the first portion 9a1 of the connection region 9a.

[0066] In the second portion 9a2 of the connection region 9a, the tether yarn 8 passes between two warp yarns 4c, 4d from the outside to the inside-directed side of the fabric layer 2, and the tether yarn 8 is interwoven with a predetermined number of adjacent single warp yarns 4d-4j in a plain weave. In the arrangement shown in FIG. 6, the tether yarn 8 is interwoven with seven adjacent single warp yarns 4d-4j in the second portion 9a2 of the connection region 9a, and the tether yarn 8 passes at least partially around three outer warp yarns 4e, 4g, and 4i of the fabric layer 2. However, in other arrangements, the tether yarn 8 may be interwoven with more than seven single adjacent warp yarns 4. For example, the tether yarn 8 may be interwoven with nine, or eleven, or thirteen single adjacent warp yarns 4 in the second portion 9a2 of the connection region 9a.

[0067] In the third portion 9a3 of the connection region 9a, the tether yarn 8 passes between two adjacent warp yarns 4j, 4k from the inwardly directed side of the fabric layer 2 to the outside of the fabric layer 2, and then floats over two adjacent warp yarns 4k, 4l on the outside of the fabric layer 2. The tether yarn 8 then passes between two further adjacent warp yarns 4l, 4m and returns into the inflatable chamber 7 of the airbag 1. In other configurations, the tether yarn 8 may float over more than two adjacent warp yarns 4 in the third portion 9a3 of the connection region 9a. For example, the tether yarn 8 may float over three adjacent warp yarns 4 in the third portion 9a3 of the connection region 9a.

[0068] In the arrangement described above with reference to FIG. 6, the tether yarn 8 floats over at least two adjacent warp yarns 4 in the first portion 9a1 and the third portion 9a3 of the connection region 9a, and is interwoven with a single adjacent warp yarn 4d-4j in the second portion 9a2 of the connection region 9a. Floating the tether yarn 8 over at least two adjacent warp yarns on one side of the fabric layer 2 in the first portion 9a2 and the third portion 9a3 of the connection region 9a allows some movement between the tether yarn 8 and the intrinsic yarns 4, 5 of the fabric layer 2, thereby absorbing some of the impact load when the airbag 1 is inflated. This can help reduce the likelihood of the tether yarn 8 breaking when the airbag 1 is inflated.

[0069] In an arrangement in which the tether yarn 8 participates in the weave of both textile layers 2, 3 in the manner shown in Fig. 6, it is envisioned that the first connection region 9a may be configured such that the tether yarn 8 interweaves with more adjacent warp yarns 4 in the second portion 9a2 of each first connection region 9a than in a comparable second portion of each second connection region 9b. In this manner, the tether yarn 8 may participate in the weave of the first textile layer 2 throughout each first connection region 9a such that the first connection region 9a is wider in the weft direction 11 than the second connection region 9b in which the tether yarn participates in the weave of the second layer 3. It is envisioned that instead each first connection region 9a may have the configuration shown in Fig. 6 and each second connection region 9b may have the (shorter) configuration shown in Fig. 5.

[0070] For convenience and clarity, FIG. 4 shows only two exemplary tether yarns 8, and FIGS. 5 and 6 each show only a single exemplary tether yarn 8. However, it should be understood that in an actual embodiment, there may be many more tether yarns 8 arranged in side-by-side relationship with one another, with the tether yarns 8 distributed between the weft yarns 5 of the two fabric layers 2, 3 and extending generally parallel to the weft yarns 5 and perpendicular to the warp yarns 4, thereby collectively defining a tether having a width that extends a distance along the warp direction of the fabric (i.e., into the page when FIGS. 4-6 are viewed). Indeed, in some embodiments, it is envisioned that the tether yarns 8 may be provided in a third layer of fabric woven from a third set of warp yarns and tether yarns 8, with the tether yarns 8 defining the weft yarns of the third fabric layer. Alternatively, the tether yarns 8 may be provided in a third layer of fabric woven in such a manner that the tether yarns 8 define the warp yarns of the third layer.

[0071] FIG. 7 shows diagrammatically an area of ​​an airbag 1 seen from above, with a first (upper) fabric layer 2 superimposed on a second (lower) fabric layer 3. The warp threads 4 of the two layers 2, 3 are substantially aligned in the direction indicated by the arrow 12, and the weft threads 5 are substantially aligned in the direction indicated by the arrow 11. A plurality of generally parallel tether threads 8 are provided between the weft threads. The warp threads participate in the weave of the upper layer 2 in a plurality of first connection regions 9a (only one complete first connection 9a is shown) spaced apart in the weft direction 11 of the fabric layers 2, 3, each of which includes a pair of connection sub-regions 9a'. The tether threads 8 also participate in the weave of the lower layer 3 in a plurality of second connection regions 9b in the manner described above, although within the area of ​​the airbag 1 shown in FIG. 7, only a single second connection 9b is shown. As can be observed, each connection sub-region 9a' and each second connection region 9b is elongated to have a length in the warp direction 12. Each connection region 9a, 9b thus extends across a region of the respective textile layer 2, 3, across a plurality of weft yarns. It will thus be appreciated that the tether yarns 8 cooperate to define a tether 10 having a width w in the warp direction 12 of the textile layers 2, 3.

[0072] In the arrangement of FIG. 7, the tether yarns 8 are all interwoven with the same warp yarns 4 that extend through the two fabric layers 2, 3, such that the sub-regions 9a′ of the first connection region 9a and the second connection region 9b are all parallel to one another and oriented such that their length directions are substantially parallel to the warp direction 12 and perpendicular to the weft direction 11. However, this is not required, and in fact in some circumstances it may be beneficial to arrange the tether yarns 8 such that successive tether yarns 8 participate in the weave of the fabric layers 2, 3 by interwoven with different groups of warp yarns 4. As will be appreciated by those skilled in the art, the effect of this may be to orient the connection regions 9a, 9b such that the elongated extensions of the connection regions 9a, 9b cross the multiple weft yarns 5 at an oblique angle to the weft yarns and therefore also to the warp yarns 4.

[0073] FIG. 8 is a view similar to FIG. 4, but showing the airbag 1 in a partially inflated state, where an initial volume of inflation gas has been directed into the inflatable chamber 7 of the airbag 1, beginning to cause the airbag to curve. FIG. 9 is a perspective view showing a cross section of an airbag 1 having a tether configuration of the type shown in FIGS. 4 and 8, but showing the airbag 1 in a substantially fully inflated state. FIG. 9 shows more clearly the width of the internal tether 10 defined by the tether thread 8. As can be seen from both figures, the inflation gas urges the two fabric layers 2, 3 away from each other so that the airbag 1 achieves a certain degree of inflation depth throughout the inflatable chamber. The movement of the fabric layers 2, 3 away from each other is restrained by the tether thread 8 extending through the airbag 1. As can be seen, the tether thread 8 is under tension and strained in this state. Due to the above-mentioned configuration of the first and second connection regions 9a and 9b, in which the tether yarn 8 is involved in the weave of the first and second textile layers 2 and 3, respectively, the first connection region 9a of the first textile layer 2 has a larger width than the second connection region 9b of the second textile layer 3 in the longitudinal direction of the tether yarn 8, so that the first and second connection regions 9a and 9b are subjected to different levels of strain. The effect of this has been found to be to induce a curvature in the airbag 1 when it is inflated, as shown in FIG. 8 and in particular in FIG. 9. As can be observed, the above-mentioned tether configuration is effective to induce a curvature in the airbag 1, which curvature is convex on the side of the first textile layer 2 (the layer with the wider tether connection region 9a) and concave on the side of the second textile layer 3 (the layer with the narrower tether connection region 9b). The airbag 1 is therefore configured to bend towards the second textile layer 3 when inflated. As can be seen, the airbag 1 bends around the longitudinal extension of the first connection region 9a and the second connection region 9b.

[0074] FIG. 10 shows a one-piece woven airbag 1 according to the invention in a pre-inflated configuration laid flat. The airbag 1 has a somewhat elongated configuration, with its second fabric layer 3 (the layer with the narrower second connection area 9b) facing upwards. The integral peripheral seam 6 of the illustrated airbag 1 follows a circuitous path with a concave area such that the resulting inflatable chamber 7 of the airbag has a shape similar to glasses, presenting two main chamber areas 7a, 7b fluidly interconnected by a narrower area 7c. Adjacent to the concave area of ​​the peripheral seam 6 on the outside of the inflatable chamber 7, the yarns of the two fabric layers 2, 3 are interwoven to define the non-inflatable area 13 of the airbag, like a thicker web of fabric.

[0075] Second connection regions 9b, where the tether yarns 8 participate in the weave of the second fabric layer 3, can also be clearly seen in FIG. 10. As can be seen, a first group of second connection regions 9b is provided in the area of ​​the fabric layer 3 that defines the first chamber region 7a, and a second group of second connection regions 9b is provided in the area of ​​the fabric layer 3 that defines the second chamber region 7b. Although not visible in FIG. 10, first connection regions 9a, where the tether yarns 8 participate in the weave of the underlying first fabric layer 2, are also provided. Similar to the second connection regions 9b, the first connection regions 9a are also divided into two groups, a first group provided in the area of ​​the underlying first fabric layer 2 that defines the first chamber region 7a, and a second group provided in the area of ​​the underlying first fabric layer 2 that defines the second chamber region 7b. The connection regions 9a, 9b of the first group (i.e. corresponding to the first chamber region 7a) are arranged to extend parallel to one another, and the connection regions 9a, 9b of the second group (i.e. corresponding to the second chamber region 7b) are also arranged to extend parallel to one another. However, it is observed that the connection regions 9a, 9b of the first group are not parallel to the connection regions 9a, 9b of the second group.

[0076] Referring now to FIG. 11, the airbag 1 of FIG. 10 is shown in an inflated state. As will be noted, the tether threads 8 forming the first and second connection regions 9a and 9b of the first group (i.e. corresponding to the first chamber region 7a) serve to induce a first curvature in the first chamber region 7a, such that the first chamber region 7a of the airbag 1 is bent upwards. Similarly, the tether threads 8 forming the first and second connection regions 9a and 9b of the second group (i.e. corresponding to the second chamber region 7b) serve to induce a second curvature in the second chamber region 7b, such that the second chamber region 7b of the airbag 1 is also bent upwards. As will be understood, the first chamber region 7a is thus adapted to achieve an inflated shape that is bent around the longitudinal extension direction of the first group of connection regions 9a, 9b, and the second chamber region 7a is thus adapted to achieve an inflated shape that is bent around the longitudinal extension direction of the second group of connection regions 9a, 9b. Thus, in this arrangement, each chamber region 7a, 7b is configured to bend in a single direction, the two directions being different from each other and defined by the direction of extension of the connection regions 9a, 9b over localized areas of the fabric layers 2,3.

[0077] 12 and 13 show an actual embodiment of an airbag 1 configured to bend in a single direction in the manner described above. The illustrated arrangement includes a pair of hip protection airbags 1 arranged and configured to provide hip protection to a person 14 in a seated position. As shown in FIG. 12, each airbag 1 is provided with a respective inflator, such as a gas generator 15, for directing a volume of inflation gas into an internal chamber 7 of the airbag 1. It is envisioned that the airbags 1 may be provided within clothing or the like configured to be worn by the person 14. The airbags 1 are arranged to inflate to respective deployment positions around respective hip areas of the person.

[0078] In order for the airbags 1 to extend below the hips of the user, the airbags 1 of Figures 12 and 13 are configured to be optimized to provide good bending characteristics about the user's sagittal axis (indicated at 16 in Figure 13). This can be achieved by orienting the connection regions 9a, 9b (in which the tether yarns 8 engage the constituent fabric layers 2, 3 of the airbag) such that they extend generally parallel or nearly parallel to the user's transverse plane (indicated at 17 in Figure 12). However, because the airbags 1 are configured to bend only about the user's sagittal axis 16, they are less well suited to bend around the sides of the user's hips, so that the airbags 1 achieve their respective inflated configurations that allow them to spread outward from the user's rear hip area and away from the user's upper thighs leaving gaps 18 between the user's legs and the respective airbags 1.

[0079] Figures 14 and 15 show alternative configurations of the hip protection airbag 1 shown in Figures 12 and 13, which are also configured to bend in a single direction in the manner described above. However, in this arrangement, the airbag 1 is configured to be optimized to provide good bending characteristics about the user's vertical axis (shown at 19 in Figure 14) so ​​that the airbag will better extend around the sides of the user's hips upon deployment, thereby addressing a potential shortcoming of the airbag 1 shown in Figures 12 and 13. This may be achieved by orienting the connection regions 9a, 9b (in which the tether yarns 8 engage the constituent fabric layers 2, 3 of the airbag) such that they extend generally or nearly parallel to the user's sagittal plane (shown at 20 in Figure 12). However, because airbag 1 is configured to bend only about the user's vertical axis 19, it is less well suited to bending under the user's hips, and as a result, airbag 1 achieves a respective inflated configuration that has less effective coverage under the user's hips than the airbags of FIGS. 12 and 13, as can be seen by comparing FIG. 15 with FIG. 13.

[0080] Therefore, in some situations it may be desirable to provide an airbag that can be optimized to flex in two directions rather than simply one.

[0081] FIG. 16 shows a short length of one-piece woven production web 21, including opposing first and second fabric layers 2 and 3. The production web 21 is woven by one-piece weaving techniques, such that the two fabric layers 2, 3 are woven simultaneously in a manner known per se on a single specially constructed loom. The warp yarns 4 of the fabric extend in a warp direction 12, and the weft yarns 5 of the fabric extend in a weft direction 11. The short length of web 21 shown in FIG. 16 can be seen to include a pair of integrally formed hip protection airbags 1, the two airbags 1 being formed within the web as mirror images of each other across a longitudinal (i.e., aligned with the warp direction 12) axis 22. The airbags 1 are defined by respective peripheral seams 6, within which the yarns of the two fabric layers 2, 3 are interwoven such that each peripheral seam 6 is formed as an integral structural feature of the fabric of the respective airbag 1.

[0082] The peripheral seam 6 of each airbag 1 defines the main inflatable area of ​​the airbag, but also defines an elongated inlet area 23 that is understood to be configured to receive an inflator. In the arrangement shown in Figure 16, it can also be seen that each airbag 1 has an additional integrally formed seam 24 that is substantially straight and extends inwardly from the peripheral seam 6. As will be explained in more detail below, the additional seam 24 of each airbag represents a flex seam and is provided to help induce a curvature in the airbag 1 when it is inflated.

[0083] Each of the airbags 1 may be removed from the production web 21 by cutting the fabric layers 2, 3 of the web around the peripheral seam 6. The resulting airbag 1, after being removed from the production web 21, is shown in Figure 17, note that the airbag 1 is shown in a different orientation than in Figure 16.

[0084] As in the previous embodiment, the airbag 1 shown in Figures 16 and 17 also comprises an internal tether arrangement of the same general configuration as described above, and thus includes a plurality of tether yarns 8 participating in the weave of the first fabric layer 2 in first connection regions 9a (each of which includes a pair of connection sub-regions 9a') and participating in the weave of the second fabric layer 3 in second connection regions 9b. The first and second connection regions 9a and 9b are all elongated and arranged to extend at an oblique angle to both the warp direction 12 and the weft direction 11. Thus, the connection regions 9a, 9b extend at an oblique angle to the warp yarns 4 and weft yarns 5 of the fabric layers 2, 3. As will be understood from the above description of the previous embodiment, the tether yarns 8 are provided between the weft yarns 5 and thus follow the weft direction 11. The tether yarns 8 are interwoven with the warp yarns 4 of the first fabric layer 2 in the first connection region 9a and with the warp yarns 4 of the second fabric layer 3 in the second connection region 9b.

[0085] The particular arrangement of the connection regions 9a, 9b in this embodiment can be most clearly understood with reference to FIG. 18, where the sub-region 9a' of the first connection region 9a (where the tether yarn 8 participates in the weave of the first fabric layer 2) is shown in solid lines and the second connection region 9b (where the tether yarn 8 participates in the weave of the second fabric layer 3) is shown in dashed lines.

[0086] In particular, in Fig. 18 it is observed that the connection regions 9a, 9b are provided in two separate groups of connection regions, a first group located within a first notional rectangular area 25 and a second (larger) group located within a second notional rectangular area 26. The two groups 25, 26 are disposed adjacent to each other, and as can be seen, each group of connection regions 25, 26 includes both a first connection region 9a (in which the tether yarns 8 participate in the weave of the first textile layer 2) and a second connection region 9b (in which the tether yarns participate in the weave of the second layer 3).

[0087] As can be observed, the connection regions 9a, 9b in the first group 25 are all substantially parallel to one another, while the connection regions 9a, 9b in the second group 26 are also substantially parallel to one another. However, the connection regions 9a, 9b of the first group 25 are non-parallel to the connection regions 9a, 9b of the second group 26. Thus, the connection regions 9a, 9b of the first group 25 extend at an oblique angle to the extension of the connection regions 9a, 9b of the second group 26.

[0088] An important difference between the configuration of the airbag 1 shown in Figures 16 to 18 and the previous embodiment shown in Figures 10 and 11 (which also has two separate groups of connection regions 9a, 9b) concerns the relationship between the connection regions 9a, 9b of the first group 25 and the connection regions 9a, 9b of the second group 26.

[0089] It should be noted that in the configuration of Figures 16-18, at least some of the sub-regions 9a' of the first and second connection regions 9a, 9b of the second group 26 extend across the extension axis 27 along which the sub-regions 9a' of the first and second connection regions 9a, 9b of the first group 25 extend. As will be appreciated in light of the above description, the tether yarn forming the first group 25 of connection regions 9a, 9b serves to induce a first curvature in the airbag 1 upon inflation, bending the airbag 1 around the longitudinal extension direction of the first group of connection regions 9a, 9b (i.e. around the extension axis 27). Thus, as will be appreciated, the second group 26 of connection regions 9a, 9b traverses the axis 27 along which the first group of connection regions induces a curvature in the airbag 1. Thereby, the second group 26 of connection regions 9a, 9b is located within the region of the airbag 1 along which a curvature is induced by the first group of connection regions 9a, 9b. Furthermore, the tether yarn forming the second group 26 of connection regions 9a, 9b serves to induce a second curvature in the airbag 1 upon inflation, bending the airbag 1 around the longitudinal extension of the second group of connection regions 9a, 9b. It will be appreciated that given that the second group 26 of connection regions 9a, 9b is non-parallel to the first group 25 of connection regions 9a, 9b, the second curvature is in a different direction or orientation than the first curvature. Because the second group 26 of connection regions 9a, 9b crosses the axis 27 along which the first group 25 of connection regions 9a, 9b induces the first curvature in the airbag 1, the effect is to induce curvatures in two different directions in the same region of the airbag 1, thereby effectively bending the airbag in two different directions.

[0090] Paying particular attention to the second group 26 of connection regions 9a, 9b, it is noted from FIG. 18 that the second group 26 is divided into two sets of connection regions 9a, 9b, namely a first set 28 located on one side of the bend seam 24 and a second set 29 located on the opposite side of the bend seam 24. The bend seam 24 thus separates the two sets 28, 29 of connection regions 9a, 9b in the second group. It is further noted that the bend seam 24 extends approximately orthogonally to the extension of the connection regions 9a, 9b in the second group 26. As can also be observed, each sub-region 9a' of the first connection region 9a of the first set 28 is aligned with a respective sub-region 9a' of the second set 29, so that each pair of aligned connection sub-regions 9a' extends in a collinear line. Similarly, each second connection portion 9b of the first set 28 is aligned with a respective second connection region 9b of the second set 29, such that each pair of aligned second connection regions 9b extend in the same straight line.

[0091] Noting that the flex seam 24 interconnects the two fabric layers 2, 3 of the airbag 1, it will be appreciated that the flex seam 24 therefore serves to limit the inflation depth of the inflatable chamber 7 between the two sets 28, 29 of connection regions 9a, 9b in the second group 26. In this manner, the flex seam 24 can help to enable the second group 26 of connection regions 9a, 9b to induce a second curvature in the airbag 1, with the flex seam 24 effectively defining a fold around which the second group 26 of connection regions 9a, 9b can more easily bend the airbag 1.

[0092] Figures 19 and 20 show a pair of airbags 1 of the configuration described above with reference to Figures 16 to 18, in an inflated state to provide improved hip protection to a person 14 in a seated position. Both airbags 1 are arranged with their first fabric layer 2 facing outwards and their second fabric layer 3 facing inwards towards the user 14.

[0093] As can be appreciated, the airbag 1 shown in Figures 19 and 20 has been optimized to provide good bending characteristics in two different directions, namely, about the user's sagittal axis 16 so that the airbag 1 extends under the user's hip, and about the user's vertical axis 19 so that the airbag 1 extends around the side of the user's hip.

[0094] A first group 25 of connection regions 9a, 9b are positioned in an upper region of the airbag 1 and are oriented to extend generally parallel or nearly parallel to the user's sagittal plane 16. The connection regions of the first group 25 are thus configured to induce a first curvature in the airbag, bending the airbag 1 about the user's vertical axis 19 so that it extends tightly around the sides of the user's hips instead of flaring outwards as observed in the single bend arrangement of Figures 12 and 13.

[0095] A second group 26 of connection regions 9a, 9b are positioned in the lower region of the airbag 1 and are oriented to extend generally parallel or nearly parallel to the transverse plane 17 of the user. The second group 25 connection regions are thus configured to induce a second curvature in the airbag, bending the airbag 1 about the sagittal axis 16 of the user, such that the airbag 1 also extends under the hips of the user, thereby providing improved coverage under the hips of the user, as compared to the single bending arrangement of Figures 14 and 15. The features disclosed in the above description or the following claims or the accompanying drawings, whether presented in a particular form or in terms of means for performing a disclosed function or methods or steps for conveniently obtaining a disclosed result, may be utilized separately or in any combination of such features to realise the invention in various forms thereof.

[0096] Although the present invention has been described in conjunction with the exemplary embodiments above, many equivalent modifications and variations will be apparent to those skilled in the art given this disclosure. Accordingly, the exemplary embodiments of the present invention set forth above are considered to be illustrative and not limiting. Various modifications to the described embodiments may be made without departing from the scope of the present invention.

[0097] For the avoidance of doubt, any theoretical explanations provided herein are provided for the purpose of enhancing the understanding of the reader, and the inventors do not wish to be bound by any of these theoretical explanations.

[0098] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0099] Throughout this specification, including the claims which follow, unless the context requires otherwise, the words "have," "comprise," and "include," as well as variations such as "having," "comprises," "comprising," and "including," are understood to imply the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps.

[0100] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include the plural unless the context requires otherwise. Ranges may be expressed herein as "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in reference to numerical values ​​is optional and may mean, for example, + / - 10%.

[0101] The terms "preferred" and "preferably" are used herein to refer to embodiments of the invention that may provide certain benefits, under some circumstances. It is to be understood, however, that other embodiments may also be preferred, under the same or different circumstances. Thus, the recitation of one or more preferred embodiments does not mean or imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure or from the claims.

Claims

1. An airbag (1) configured to be inflated by a gas source, comprising: The airbag (1) is formed from a first fabric layer (2) and a second fabric layer (3) arranged in a superimposed relationship to define an inflatable chamber (7) between the first fabric layer (2) and the second fabric layer (3) for receiving inflation gas; Each of the first fabric layer (2) and the second fabric layer (3) has a structure including at least one thread (4, 5); the first fabric layer (2) and the second fabric layer (3) are interconnected by at least one tether thread (8) extending between the first fabric layer (2) and the second fabric layer (3) within the inflatable chamber (7); the or each tether yarn (8) participates in the construction of the first fabric layer (2) in a plurality of first connection regions (9a) and participates in the construction of the second fabric layer (3) in a plurality of second connection regions (9b); Each of the first connection regions (9a) is wider than each of the second connection regions (9b) in the longitudinal direction of the or each tether thread (8); the second connection area (9b) is offset relative to the first connection areas (9a) so as not to face any of the first connection areas (9a) across the inflatable chamber (7); at least one said tether thread (8) thereby functions to induce a curvature in said airbag (1) when an inflatable chamber (7) of said airbag (1) is inflated, Airbag (1).

2. the first connection regions (9a) are spaced apart from one another over at least a portion of the first fabric layer (2); the second connection regions (9b) are spaced apart from one another over at least opposing portions of the second fabric layer (3); An airbag (1) according to claim 1.

3. 3. The airbag (1) according to claim 2, wherein a location of the second fabric layer (3) of at least one second connection region (9b) is sandwiched between locations of the first fabric layer (2) of two adjacent first connection regions (9a).

4. 3. The airbag (1) according to claim 2, wherein the tether thread (8) does not participate in the structure of the first fabric layer (2) between the second connection regions (9b) and does not extend between any of the second connection regions (9b).

5. At least one said first connection region (9a) comprises a plurality of spaced apart connection sub-regions (9a'), the or each tether yarn (8) participates in the structure of the first textile layer (2); the or each tether thread (8) extends between the connection sub-regions (9a') of the or each first connection region (9a) without participating in the structure of either the first fabric layer (2) or the second fabric layer (3) between the connection sub-regions (9a'); An airbag (1) according to claim 2.

6. 6. The airbag (1) according to claim 5, wherein each of the first (2) and second (3) fabric layers is woven and has a weave including a plurality of generally parallel yarns (4).

7. 7. The airbag (1) according to claim 6, wherein the or each tether thread (8) is interwoven with threads (4) of the first fabric layer (2) in each first connection region (9a) and with threads (4) of the second fabric layer (3) in each second connection region (9b).

8. 8. The airbag (1) according to claim 7, wherein the or each tether yarn (8) is interwoven with yarns (4) of either the first fabric layer (2) or the second fabric layer (3) only in the connection regions (9a, 9b).

9. 7. The airbag (1) according to claim 6, wherein the or each tether yarn (8) is interwoven with the yarns (4) of the first textile layer (2) only in the connection sub-region (9a') and with the yarns (4) of the second textile layer (3) only in the second connection region (9b).

10. the generally parallel weaving yarns (4) of each of the first fabric layer (2) and the second fabric layer (3) are warp yarns (4); Each of the first fabric layer (2) and the second fabric layer (3) further comprises a plurality of generally parallel weft yarns (5); the or each tether thread (8) extends generally parallel to the weft threads (5); An airbag (1) according to claim 6.

11. the generally parallel yarns of each of the first fabric layer (2) and the second fabric layer (3) are warp yarns (4); Each of the first fabric layer (2) and the second fabric layer (3) further comprises a plurality of generally parallel weft yarns (5); The airbag (1) includes a plurality of the tether threads (8), the tether yarns (8) extend generally parallel to the weft yarns (5) of the first fabric layer (2) and the second fabric layer (3); An airbag (1) according to claim 6.

12. Each of said connection regions (9a, 9b) is generally elongate; the first and second connection regions (9a) and (9b) extend generally parallel to each other and across the first and second fabric layers (2) and (3) of the airbag (1), respectively, so as to cross the weft threads (5) of the first and second fabric layers (2) and (3); An airbag (1) according to claim 11.

13. 13. The airbag (1) according to claim 12, wherein the first connection region (9a) and the second connection region (9b) cross the plurality of weft threads (5) at an oblique angle relative to the weft threads (5) and cross the plurality of warp threads (4) at an oblique angle relative to the warp threads (4).

14. 7. The airbag (1) of claim 6, wherein the airbag (1) is a one-piece woven airbag including at least one integrally woven seam (6) defined by an area where yarns (4, 5) of one of the weaves of the first and second fabric layers (2) and (3) are interwoven with yarns (4, 5) of the other of the first and second fabric layers (2) and (3).

15. 15. The airbag (1) according to claim 14, wherein the or each tether thread (8) is integrally woven into the weave of the first fabric layer (2) and the second fabric layer (3) in the connection region (9a, 9b).

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