Airbag for a motor vehicle safety arrangement

Abstract

An airbag (11) for a motor vehicle safety arrangement is proposed. The airbag (11) comprises a pair of overlapping layers (7a, 7b) of a flexible material connected by a circumferential seam (8) to define an inflatable chamber (9) for receiving inflation gas between the layers (7a, 7b). The airbag (11) is initially provided in a deflated state, in which at least one region of the airbag (11) is rolled into a spirally wound roll (13) having a wound length (e.g., an arc-shaped or spirally wound length) of the circumferential seam (8). Within the roll (13), the overlapping regions of the airbag (11) are attached to one another adjacent to the wound length of the circumferential seam (8).

Description

Field of invention

[0001] The present invention relates to an airbag for a motor vehicle safety arrangement. background

[0002] Inflatable airbag systems are well-known in the automotive industry. Airbags have been a standard feature in vehicle cabins, such as those of passenger cars, for many years to protect occupants in accidents, such as collisions. These airbags deploy rapidly in the event of an impending or actual collision to cushion the impact of a vehicle occupant against vehicle components like the steering wheel or dashboard. Over time, it has become common practice to install additional airbags in various locations within a vehicle's interior to provide extra or enhanced protection in different types of accidents, such as rollovers and side impacts. For example, it is now standard practice to equip vehicles with airbags in the form of inflatable curtains, side airbags, knee airbags, and airbags of various configurations for rear passengers.Some vehicles even include airbags that deploy across parts of the vehicle's exterior to protect pedestrians or so-called vulnerable road users (VRUs), such as cyclists or motorcyclists, if they are struck by the vehicle in an accident. As can be seen, it is important that such airbags inflate quickly to provide effective protection, so they can reach their essentially full deployment very rapidly.

[0003] Regardless of the specific type of airbag, the inflation gas must be injected into the airbag at very high pressure from a source such as a gas generator to ensure it inflates quickly enough to provide adequate impact protection. Acceptable inflation times vary between different types of airbags, depending on their intended function. For example, inflatable curtain airbags, which deploy inside a vehicle through the side windows to protect occupants in the event of a rollover, must inflate very quickly. This is because the distance between the vehicle's occupants and the side windows is very limited, thus reducing the time available for the inflatable curtain airbag to fully inflate and limiting its inflation depth.These factors mean that inflatable curtain airbags must not only inflate very quickly, but also at a particularly high pressure compared to other types of automotive airbags. Furthermore, due to the potentially longer duration of a rollover accident, in which the inflatable curtain airbags are intended to protect the occupants, inflatable curtain airbags must maintain a virtually fully inflated state for a significantly longer period than most other types of automotive airbags. Accordingly, inflatable curtain airbags generally require the highest pressure retention performance of all types of automotive airbags.

[0004] The aforementioned performance characteristics of inflatable curtain airbags mean that the integrity of the seams of such airbags is of particular importance to prevent the escape of inflation gas during the period in which the airbag must remain essentially fully inflated. Accordingly, it is known to design inflatable curtain airbags (as well as some other types of high-performance automotive airbags) as one-piece woven (“OPW”) airbags, in which the seams of the airbag (e.g., the circumferential seam) are formed integrally from the woven structure of the two fabric layers that define the airbag.In these OPW airbags, the inflatable chamber is formed between two layers of fabric (in a so-called "2D" construction), and the seams are defined by areas where the yarns of one layer are interwoven with those of the other, making the seams an integral feature of the fabric's structure. This structure provides excellent seam integrity.

[0005] Although one-piece weaving has proven particularly suitable for inflatable curtain airbags, it is a rather complex and specialized production technique which, while suitable for automation on specially configured weaving machines, can be expensive and is therefore not suitable for all types of airbags. Furthermore, while one-piece weaving is well-suited for manufacturing airbags with a slim inflated profile (e.g., so-called "2D" airbags), achieved by providing an inflatable chamber between two overlapping layers of fabric, it can often be unsuitable for airbags intended to have a more voluminous inflated shape (e.g., so-called "3D" airbags) and which can be manufactured from more than two interconnected flexible panels to achieve a desired inflated shape and / or volume.

[0006] So-called "3D" airbags typically require manual sewing to join the individual panels together. These sewn seams have lower integrity than the OPW seams mentioned above. Furthermore, sewn seams are prone to gas leakage during inflation, which can lead to seam damage and potential airbag rupture either during inflation or after it has been substantially inflated.

[0007] Another phenomenon that some airbags may be subject to is so-called "clocking" or "bouncing," which refers to the tendency of inflated airbags (especially large 3D airbags) to move around due to inertia caused by high inflation forces during deployment. This phenomenon can be problematic because an airbag that tends to move or bounce during inflation is difficult to reliably position relative to the vehicle surfaces from which it is intended to protect the occupant.

[0008] Furthermore, it can be complicated and time-consuming (and therefore expensive) to reliably fold a 3D airbag on a production line in order to package the airbag into an airbag module ready for installation.

[0009] DE 10 2015 008 801 A proposes an airbag with a mounting area. DE 10 2006 028 933 A discloses an airbag for a vehicle occupant restraint device, comprising an upper part with a sheath section extending between two opposing edge sections, wherein a seam extends over the sheath section and an outer contour of the upper part is congruent with an outer contour of a lower part. DE 10 2015 000 737 A proposes an airbag for a vehicle occupant restraint system and a method for manufacturing the airbag.

[0010] The present invention was developed in light of the aforementioned circumstances. Summary of the invention

[0011] According to a first aspect of the invention, an airbag is provided for a motor vehicle safety arrangement, wherein the airbag comprises a pair of superimposed layers of flexible material connected to each other by a circumferential seam to define an inflatable chamber for receiving inflation gas between the layers, wherein the airbag is initially provided in an uninflated state in which at least one region of the airbag is rolled to form a spirally wound roll containing a wound length of the circumferential seam, characterized in that: within the roll the superimposed regions of the airbag are attached to each other adjacent to the wound length of the circumferential seam.

[0012] According to a second aspect of the present invention, an airbag is provided for a motor vehicle safety arrangement, wherein the airbag comprises a pair of superimposed layers of flexible material connected to each other by a circumferential seam to define an inflatable chamber for receiving inflation gas between the layers, wherein the airbag is initially provided in an uninflated state in which at least one region of the airbag is rolled to form a roll containing a spirally wound length of the circumferential seam, wherein: within the roll the superimposed regions of the airbag are attached to each other adjacent to the spirally wound length of the circumferential seam.

[0013] It has been shown that an airbag configured according to either the first or the second aspect exhibits an advantageous property when inflated by blowing a volume of inflation gas into the inflatable chamber defined between the overlapping layers of flexible material. Due to the way in which the overlapping sections of the airbag are attached to one another adjacent to the wound length (e.g., the spirally wound length) of the circumferential seam within the roll, the seam will twist as the roll opens under the influence of the inflation gas during inflation. This seam-twisting effect has been shown to reduce gas leakage through the seam and thereby improve the integrity of the seam.In embodiments, for example, where the circumferential seam is a sewn seam, the twist introduced into the seam area of ​​the airbag serves to conceal the seam behind a portion of the airbag material within the twist. However, it is evident that the circumferential seam, which connects the overlapping layers of the flexible material, need not be formed by sewing, but can (for example) be formed by bonding or fusing the two layers together, with the twist introduced into the seam area of ​​the airbag also serving to conceal the bonded or fused area of ​​the seam behind a portion of the airbag material within the twist.

[0014] Furthermore, it has been shown that the twisted seam creates a tension line in the airbag material towards the side of the airbag, which provides a beneficial effect in improving the stability of the inflated airbag.

[0015] In some embodiments, the pair of overlapping layers can take the form of a respective section of the same flexible material. For example, a single flexible material could be folded so that two sections of the material overlap, and the two resulting layers could then be joined together by a circumferential seam. Alternatively, other embodiments are conceivable in which each layer can be defined by a separate flexible material. For example, two single flexible material sheets (possibly with substantially identical or similar shapes) could be arranged one on top of the other and joined together by a circumferential seam.

[0016] As experts will recognize, the flexible material of the layers (or webs) can assume any suitable form, such as woven fabric or a suitable thin-film material, like a thin film of plastic. In embodiments where the layers (or webs) are made of fabric, it is conceivable that the circumferential seam could be formed by sewing the two layers together. Alternatively, some embodiments can also be formed by simultaneously weaving the two layers on a single loom using a so-called "one-piece weaving" technique, in which the yarns of one layer are interwoven with the yarns of the other layer in specific zones to define the circumferential seam.

[0017] In some embodiments, the airbag may comprise a pair of circumferential seam regions that are opposite each other over at least one region of the inflatable chamber; wherein, in the deflated state, the roll contains a respective wound (e.g., spirally wound) length of each circumferential seam region; and wherein, within the roll, the overlapping regions of the airbag are attached to one another adjacent to the wound length of each circumferential seam region. This arrangement can effectively provide the aforementioned advantages on two opposite sides of the airbag. In particular, this can result in a relatively simple 2D airbag construction, comprising a pair of overlapping layers of flexible material, acquiring a 3D shape upon inflation.In such arrangements, the resulting respective stress lines in the airbag material can provide a particularly stable airbag on each side of the airbag, which is well suited for precise and reliable positioning within or against a surface of the motor vehicle during deployment.

[0018] If necessary, in the deflated state the roll is formed around a roll axis that extends across the airbag from one circumferential seam area to the other circumferential seam area.

[0019] In some embodiments, each wound length of a seam area can be arranged at a respective end of the roll.

[0020] The overlapping areas of the airbag within the roll can be attached to each other in various ways and / or by various means, for example by sewing, gluing, fusing and mechanical clamping.

[0021] In some embodiments, the overlapping sections of the airbag within the roll can be sewn together. In some such examples, the seam can be formed through both layers of the airbag, providing a first inflation property (e.g., an inflated shape). In other examples, the seam can be formed through at least four overlapping thicknesses of the flexible material resulting from the airbag being rolled into the roll, providing a second inflation property (e.g., another inflated shape). In embodiments where the roll results in a multiply wound length of seam or seam section, the seam can, for example, be formed through more than four overlapping thicknesses of the flexible material.

[0022] In some alternative embodiments, a series of fastening holes can be formed through the airbag adjacent to the circumferential seam. The fastening holes can be spaced apart from one another along the wound length (e.g., a spirally wound or arc-shaped length) of the circumferential seam so that they are substantially aligned with each other within the roll. In such embodiments, a fastening means can be provided through the substantially aligned fastening holes to secure the overlapping portions of the airbag within the roll.

[0023] Similarly, in embodiments comprising a pair of circumferential seam regions opposite each other in a region of the inflatable chamber, a respective set of fastening holes can be formed through the airbag adjacent to each circumferential seam region. The fastening holes of each set can be spaced apart from one another along the wound length (e.g., a spirally wound or arc-shaped length) of the respective circumferential seam region such that they are substantially aligned with each other within the roll. In such an arrangement, a respective fastening means can be provided through the substantially aligned fastening holes of each set to secure the respective overlapping regions of the airbag within the roll.

[0024] If necessary, at least some of the mounting holes of the set or sets are oriented substantially radially to each other over a portion of the roller.

[0025] The fastening means or means may be provided by the substantially radially aligned mounting holes of the respective set or sets to fasten the overlapping areas of the airbag on one side of the roll together, such that overlapping areas of the airbag on a diametrically opposite side of the roll are not fastened together.

[0026] Alternatively or additionally, at least some of the mounting holes of the set or each set above the roller can be oriented essentially diametrically opposite each other.

[0027] The fastening device or devices may be provided through the substantially diametrically aligned mounting holes of the respective set or sets to fasten the overlapping areas of the airbag to one another via the roller.

[0028] The fastening device(s) may be provided in the form of a mechanical fastener. For example, the fastening device(s) may be provided in the form of a metal or plastic bracket, a cable tie, or any other suitable mechanical fastener capable of connecting the aligned holes of the airbag.

[0029] According to a third aspect, an airbag according to the first aspect or the second aspect is provided in combination with an inflation device configured to direct inflation gas into the inflatable chamber in a primary inflow direction, wherein: the wound length of the circumferential seam or the wound lengths of the circumferential seam areas are spaced from the primary inflow direction such that the inflation gas does not directly impinge upon it. Such an arrangement can serve to further reduce the risk of damage to the circumferential seam or seam areas and / or the escape of inflation gas through the circumferential seam or seam areas.

[0030] The invention includes the combination of the described aspects and preferred features, unless such a combination is obviously impermissible or is expressly excluded.

[0031] Experts will recognize that a feature or parameter described in relation to one of the aspects mentioned above can also be applied to any other aspect, unless they are mutually exclusive. Furthermore, each feature or parameter described herein can be applied to any aspect and / or combined with any other feature or parameter described herein, unless they are mutually exclusive. Summary of the characters

[0032] To better understand the invention and to illustrate further features of the invention, embodiments of the invention are now described by way of example with reference to the attached drawings: Fig. Figure 1 is a schematic top view of a pair of superimposed layers of fabric used to form an airbag according to the invention; Fig. Figure 2 is a view that generally corresponds to claim 1 and shows the layers of material after joining to define an inflatable chamber of the airbag; Fig. Figure 3 is a schematic perspective view showing the formation of a roll in the airbag and one way in which overlapping areas of the airbag can be attached to each other within the roll; Fig. 4 is a schematic cross-sectional view showing the role of the in Fig. 3 airbags shown; Fig. Figure 5 is a perspective view showing the airbag in an inflated (e.g., deployed) state; Fig. Figure 6 is a perspective view from above, showing a different shape of the airbag before it forms a roll; Fig. Figure 7 is a perspective view similar to that of Fig. 6, which, however, shows the airbag in a rolled-up state and in which the overlapping areas of the airbag are attached to each other within the roll; Fig. 8 is a schematic cross-section of the role of the in Fig. 7 airbags shown, which demonstrates one way in which overlapping areas of the airbag can be attached to each other within the roll; Fig. Figure 9 is a perspective view from above, showing the rolled-up airbag. Fig. 7 after a subsequent connecting step shows; Fig. 10 is a perspective view from one side of the [image / structure] in the Fig. 6, Fig. 7, Fig. 8 to Fig. 9 airbags shown, which depict the airbag in a non-inflated (e.g., not deployed) state and in combination with an airbag module housing; Fig. Figure 11 is a perspective view similar to that of Fig. 10, showing the airbag during an early stage of inflation; Fig. 12 is a perspective view similar to that of Fig. 11, which shows the airbag during a later stage of inflation; Fig. Figure 13 is a perspective view similar to that of Fig. 12, which shows the airbag during a later stage of inflation; Fig. Figure 14 is a perspective view similar to that of Fig. 13, showing the airbag in a substantially fully inflated (e.g., substantially fully deployed) state; Fig. 15 is a perspective view from the front, showing the airbag. Fig. 14 in the substantially fully inflated (e.g. substantially fully unfolded) state; Fig. Figure 16 is a schematic cross-sectional view similar to that of Fig. 8, which, however, shows an alternative way in which overlapping areas of the airbag can be attached to each other within the roll; and Fig. Figure 17 is a schematic top view of another form of airbag, which is the one in Fig. 6 shows something similar, with the airbag depicted before it forms a roll. Detailed description of the invention

[0033] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

[0034] Fig. Figure 1 represents a single strip of flexible material in the form of a strip of woven fabric 1. The strip 1 has a generally rectangular and somewhat elongated shape, with a protruding inlet flap 2 at each end. In each inlet flap 2, a pair of spaced-apart mounting openings 3 is formed. In the Fig. In the configuration shown in Figure 1, the path 1 is essentially mirror-symmetrical about a central transverse axis 4 of the path.

[0035] In Fig. 2 shows track 1 folded in half around a fold line 5, which is shown with the in Fig. The transverse axis 4 shown in Figure 1 coincides with the other half of the sheet. As can be seen, sheet 1 is shown in a folded configuration, which includes a fold 6 in which each half of sheet 1 defines a respective layer 7a, 7b, such that the two layers 7a, 7b are arranged one above the other (in Figure 1). Fig. In this view, only the uppermost layer 7a is visible. As also noted, the two inlet tabs 2 are stacked on top of each other and aligned with each other, as are their respective mounting openings 3.

[0036] After the two layers 7a, 7b are superimposed as described above, the layers are joined together by forming a pair of circumferential seam areas 8a, 8b. In the illustrated embodiment, each circumferential seam area 8a, 8b is a sewn seam and extends from a respective end region of the fold 6 along and adjacent to a respective side edge of the superimposed layers 7a, 7b, ending at the aligned inset flaps 2. It should be noted that the end edges of the two inset flaps 2 are not connected to each other.

[0037] The fold 6 and the two circumferential seam regions 8a, 8b together form a circumferential seam 8, which connects the superimposed layers 7a, 7b around their aligned circumferences, except at the ends of the two inlet flaps 2, which remain unconnected. The circumferential seam 8 extends substantially over the entire circumference of the folded panel 1, except at the superimposed ends of the two inlet flaps 2. As can be seen, this defines an inflatable chamber 9 between the layers 7a, 7b for receiving inflation gas, with the circumferential seam regions 8a, 8b facing each other across the inflatable chamber 9. The inlet tabs 2 together define an inlet area 10 (e.g. a tapered area) of the inflatable chamber 9, which can be connected via the mounting openings 3 in a known manner to an inflation device (e.g. in the form of a gas generator, not shown).

[0038] It should be noted here that while the illustrated embodiment is formed by folding a single sheet 1 into two superimposed layers 7a, 7b, other embodiments are conceivable in which each layer is formed by a separate sheet of flexible material. For example, two individual sheets of flexible material could be arranged one above the other and joined together by a single circumferential seam extending along the entire length of their edges (except at the ends of the inlet flaps 2, as explained above). In such an arrangement, the resulting single circumferential seam can nevertheless be considered as comprising a pair or seam regions that are similarly positioned opposite each other across the inflatable chamber 9.

[0039] Alternative embodiments are also conceivable in which the two superimposed layers are woven simultaneously on a single loom using a so-called "one-piece weaving" technique. In this technique, the yarns of one layer are interwoven with the yarns of the other layer in specific zones to define the circumferential seam. In such embodiments, the resulting circumferential seam is woven as an integral part of both fabric layers, while the layers remain separated from each other within the boundaries of the circumferential seam, thus defining the inflatable chamber. In a one-piece woven embodiment of this type, the resulting integral circumferential seam can also extend around the entire edges of the superimposed layers (except at the ends of the inlet flaps 2, as explained above).In such an arrangement, the resulting single circumferential seam can be considered as comprising a pair or seam areas that are similarly opposite each other across the inflatable chamber 9.

[0040] To return to the illustrated embodiment, it shows Fig. 3 a partially deployed airbag 11, which deploys by rolling up the in Fig. The two superimposed and interconnected layers 7a and 7b shown are formed. Arrow F indicates the intended primary inflow direction for inflation gas from an inflation device. In particular, it shows Fig. 3 the airbag 11 in an uninflated state in which the area of ​​the airbag distal to the inlet area 10 (i.e. proximal to the fold 6) is rolled about a roll axis 12 (as indicated by the arrow in Fig. 3), to form a roll 13. During the formation of the roll 13, a respective seam line 14 is formed at each end of the roll 13 to fasten the overlapping areas of the airbag that are incorporated into the roll 13 to one another. As shown, the seam lines 14 are each adjacent to and slightly inward from a respective circumferential seam area 8a, 8b. The resulting arrangement is shown in Fig. Figure 4 illustrates this more clearly, showing a schematic cross-sectional view through one end of the roll 13. As can be seen, the formation of the roll 13 serves to wind the airbag 11 spirally, so that the roll 13 has a spirally wound length of each circumferential seam area 8a, 8b at each end of the roll 13. As can be seen, each spirally wound length of a respective circumferential seam area is wound spirally around the rolling axis 12 of the roll 13. The resulting overlapping areas of the airbag 11 are thus attached to one another by the seam lines 14 adjacent to each spirally wound section of the circumferential seam. The seam lines 14 each run through both fabric layers 7a, 7b (in Fig. (4 are the layers in close contact shown) and thus by a total of four thicknesses of the fabric material from which the airbag 11 is made. As shown Fig. As can be seen from Figure 4, the seams in the illustrated embodiment can be so long that they extend around a full rotation of the airbag 11 around the roll axis 12, although this is obviously not considered essential in all embodiments.

[0041] Fig. Figure 5 shows the airbag 11 described above in combination with an airbag module housing 15 and in a substantially fully inflated state. As can be seen by those skilled in the art, the airbag 11 can be inflated in the Fig. 3 and Fig. The rolled airbag 11 shown in Figure 4 is further packaged (e.g., by further rolling and / or folding) so that it is initially tightly packed in the airbag module housing 15, from where it can be deployed by inflation. During inflation, the airbag 11 is inflated by the rapid flow of inflation gas along the inflow direction F through the inlet area 10 of the airbag and into the inflatable chamber 9, thus expanding from its initial, tightly packed state into the expanded state shown in Figure 4. Fig. The inflated state shown in Figure 5 is transformed by pushing the superimposed layers 7a and 7b away from each other. As can be seen, during inflation the inflation gas is guided along the primary direction F and forced around and through the initially tightly wound roll 13, which serves to open the roll 13 and finally unfold the fold 6 at the center of the roll 13. The position of the unfolded fold 6 is shown by the dashed line around the Fig. 5 depicted inflated airbag. As can also be seen, particularly with regard to the Fig. 3 and Fig. 5, the initially spirally wound lengths of the circumferential seam areas 8a, 8b, which are attached to each other, are located at the opposite ends of the roll 13, so that they are effectively spaced away from the primary inflow direction F, so that the inflation gas does not directly hit them during inflation.

[0042] Due to the way in which the overlapping areas of the airbag 11 within the initial roll 13 are attached to one another by the seam lines 14 adjacent to the initially spirally wound lengths of the circumferential seam areas 8a, 8b, the ends of the roll 13 cannot open along the seam lines 14 in the same way as the rest of the roll. This causes the circumferential seam areas 8a, 8b to twist along the length of the connecting lines of the seams 14, so that the circumferential seam areas 8a, 8b are effectively concealed in the surrounding areas of the airbag fabric. In fact, in Fig. Figure 5 shows that the circumferential seam area 8a, visible in the inlet area 10 of the airbag 11, is concealed by the airbag's outer fabric (the course of the circumferential seam area 8a is therefore shown as a dashed line). The twist introduced into the seam areas 8a and 8b of the airbag thus effectively serves to conceal (and therefore protect) the seams of the circumferential seam 8 behind a portion of the airbag material within the resulting twist. This has been shown to reduce gas leakage through the seam 8 and thus improve the integrity of the seam 8.

[0043] In the Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15 to Fig. 16 describes a further embodiment in which the same reference numerals are used to identify identical or equivalent parts or areas.

[0044] Fig. Figure 6 shows a single fabric web 1, which is essentially the same as the one described above with reference to the Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. The web described in section 5 is identical and is shown in a folded configuration, which includes a fold 6 and in which each half of the web defines a respective layer 7a, 7b. As can be seen, the two layers 7a, 7b are thus arranged one above the other (in Fig. In this view, only the uppermost layer 7a is visible (6). The resulting layers 7a, 7b are in turn connected to each other by a pair of sewn circumferential seam areas 8a, 8b in the same way as described above with reference to the Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5 described.

[0045] In the same manner as described above, the fold 6 and the two circumferential seam regions 8a, 8b together form a circumferential seam 8 that connects the superimposed layers 7a, 7b to each other around their aligned circumferences, except at the ends of the two inlet flaps 2, which remain unconnected. In this embodiment as well, the circumferential seam 8 thus extends substantially around the entire circumference of the folded sheet 1, with the exception of the superimposed ends of the two inlet flaps 2. As can be seen, this defines an inflatable chamber 9 between the layers 7a, 7b for receiving inflation gas, with the circumferential seam regions 8a, 8b facing each other across the inflatable chamber 9. The inlet flaps 2 together define an inlet area 10 (e.g., a tapered area) of the inflatable chamber 9, which is connected in a known manner to an inflation device (e.g., a blower, a blower, etc.).can be connected in the form of a gas generator (not shown).

[0046] A significant difference between the in Fig. The arrangement shown in section 6 and the embodiment described above consists in the fact that in the Fig. In the arrangement shown in Figure 6, two sets of spaced-apart mounting holes 16 are formed through both layers 7a, 7b, such that each mounting hole 16 extends completely through the airbag 11 within the limits defined by the circumferential seam 8. Specifically, it should be noted that each set of mounting holes 16 is formed along and adjacent to a respective circumferential seam region 8a, 8b, so that the mounting holes 16 of each set are spaced apart from each other along the respective circumferential seam region 8a, 8b. In preferred embodiments, it is proposed that the mounting holes 16 of each set may be substantially equidistant from each other along the respective circumferential seam region 8a, 8b, although this is not strictly necessary in all embodiments.In the arrangement shown, each mounting hole 16 of one set is arranged opposite a corresponding mounting hole 16 of the other set, transverse to a transverse direction (i.e., essentially parallel to the fold 6) of the airbag 11. In the arrangement shown in . Fig. In the specific arrangement shown in Figure 6, a circular seam is formed around each fastening hole 16, which, as shown, can take the form of a loop in one of the circumferential seam areas 8a, 8b. Alternatively, the circular seams around the fastening holes 16 can also be formed separately from the circumferential seam areas 8a, 8b.

[0047] It should be noted at this point that in an alternative design of the in Fig. In the embodiment shown in Figure 6, two superimposed layers 7a, 7b can be woven simultaneously on a single loom using a so-called "one-piece weaving" technique. In this technique, the yarns of one layer are interwoven with the yarns of the other layer in specific zones to define the circumferential seam 8. In such embodiments, the resulting circumferential seam 8 and its loops around the respective attachment holes 16 (or separate circular seams around the attachment holes) are woven as integral components of both fabric layers, while the layers remain separate from each other within the boundaries of the circumferential seam, thus defining the inflatable chamber. In a one-piece woven embodiment of this type, the resulting integral circumferential seam 8 can also extend around the entire edges of the superimposed layers (except at the ends of the inlet flaps 2, as explained above).In such an arrangement, the resulting single circumferential seam 8 can still be considered as comprising a pair of seam areas 8a, 8b that are similarly opposite each other across the inflatable chamber 9.

[0048] Fig. Figure 7 shows a partially deployed airbag 11, which is inflated by rolling up the Fig. The superimposed and interconnected layers 7a, 7b shown in the 6 are created in the same manner as described above in connection with the embodiment of the Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5 described. The arrow F indicates the primary inflow direction for inflation gas from an inflation device. In particular, it shows Fig. 7 the airbag 11 in a deflated state in which the area of ​​the airbag distal to the inlet area 10 (i.e., proximal to the fold 6) is rolled about a roll axis 12 to form a roll 13. During the formation of the roll 13, at least some of the attachment holes 16 along each circumferential seam area 8a, 8b are aligned with each other as they are incorporated into the roll 13, as shown in Fig. Figure 8, a schematic cross-sectional view through one end of the roll 13, is shown more clearly. In particular, as in Fig. Figure 8 shows (in which a total of five fastening holes 16 are incorporated into the roll 13), the fastening holes 16 which are incorporated into the roll 13 are oriented essentially diametrically opposite each other across the roll 13.

[0049] As can be seen, the formation of the roll 13 serves to wind the airbag 11 spirally, so that the roll 13 has a spirally wound length of each circumferential seam region 8a, 8b at each end of the roll 13, similar to the embodiment described above. As is therefore understandable, each spirally wound length of a respective circumferential seam region is wound spirally around the rolling axis 12 of the roll. The resulting overlapping sections of the airbag 11 are then fastened together by a respective fastening element 17 (in Fig. (8 schematically shown) is guided through the diametrically oriented fastening holes 16 of each set adjacent to the spirally wound length of the respective circumferential seam area 8a, 8b. In the Fig. In the arrangement shown in Figure 7, the fasteners 17 are each depicted in the form of a conventional cable tie, but it is evident that other forms of mechanical fasteners can also be used, such as shackles, clamps, clips, staples, or the like. As shown in Fig. As shown in Figure 8, in this embodiment each fastening element 17 is integrated through all diametrically aligned fastening holes 16 in the roller 13 and thus serves to fasten diametrically opposite sides of the roller 13 to one another and thereby secure the overlapping areas of the airbag 11 within the roller 13 to one another. It should be noted that the fastening element 17, although it is in Fig. Figure 8, which is schematically shown as extending over the diameter of the roller 13, serves in practice (e.g., to tighten) to bring the fastening holes 16 on one side of the roller 13 into close, immediate proximity to the fastening holes 16 on the diametrically opposite side of the roller 13, thereby flattening the ends of the roller 13, as shown in Fig. 9, which will be examined in more detail below, is evident.

[0050] Fig. Figure 9 illustrates a further possible step in which the end sections of the roll 13 (which, as explained above, are shown slightly flattened by the fasteners 17) are folded (labeled 18) and the two uppermost corners 19 of the airbag (in the illustrated orientation) are brought very close together. These two corners 19 can then be fastened together by inserting a third fastener 20 through the respective corner fastening holes 16c, which are not incorporated into the roll 13. By fastening the corners 19 together in this way, the airbag 11 can be given a funnel shape adjacent to the inlet area 10 when inflated.

[0051] Fig. Figure 10 shows the airbag 11 described above in combination with an airbag module housing 15 and in a partially packaged and uninflated state, which corresponds to the one described in Fig. The condition is similar to that shown in Figure 9. In particular, it should be noted that the inlet area 10 is connected to the housing 15 and the airbag 11 is loosely folded, so that the roll 13 is folded into thirds at 18. In the illustrated orientation, the attached corners 19 of the airbag are located below the airbag 11, near the module housing 15. As can be seen by those skilled in the art, the Fig. The 10 shown rolled and folded airbag 11 is further packaged (e.g. by further rolling and / or folding) so that it is first firmly packed into the airbag module housing 15 in order to be unfolded by inflation.

[0052] Fig. 11 is a similar view to that in Fig. Figure 10, however, shows the airbag 11, which is partially inflated and thus assumes a shape and configuration corresponding to an early stage of inflation during deployment from the module housing 15. It is evident, however, that Fig. 11 and also the Fig. 12, Fig. 13 to Fig. Figure 14 shows that the airbag 11 is inflated manually by a blower 21, which is introduced into the airbag 11 through a makeshift inlet opening 22, and not by the action of an inflation device (e.g., a gas generator) provided within the module housing 15, as would be the case during operational inflation of the airbag 11. As can be understood, in an operational installation, the airbag 11 is inflated by a rapid inflow of inflation gas from an inflation device located within the module housing 15 and configured to direct the gas flow in a primary inflow direction F that does not encounter the initially spirally wound lengths of the circumferential seam regions 8a, 8b, which are fastened together by the mechanical fasteners 17 at opposite ends of the roll 13. However, Figure 14 shows that the airbag 11 is inflated manually by a blower 21, which is introduced into the airbag 11 through a makeshift inlet opening 22, and not by the action of an inflation device (e.g., a gas generator) provided within the module housing 15, as would be the case during operational inflation of the airbag 11. Fig. 11 precisely the initial inflation of the airbag 11, in which the layers 7a, 7b are pushed away from each other and the roll 13 of the airbag 11 opens. In fact, it shows Fig. 11, that the roll 13 is almost completely open in the central area between its two opposite ends, and that the originally spirally wound lengths of the circumferential seam areas 8a, 8b, along which the overlapping areas of the airbag 11 are fastened to one another by the mechanical fasteners 17, are prevented from opening in the same manner. As shown, the circumferential seam areas 8a, 8b (in Fig. 11 (only 8b is visible) to twist in a similar manner as described above in connection with the embodiment of the Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5 described.

[0053] The Fig. 12 and Fig. 13 show similar views to the Fig. 11, but show the airbag 11 in successive inflation stages. Fig. Figure 12 therefore shows the airbag 11, which is inflated to a higher internal inflation pressure than Fig. 11, and Fig. Figure 13 also shows the airbag 11, which is inflated to a higher internal inflation pressure than Fig. 12. The Fig. 12 and Fig. Figure 13 shows the initially visible circumferential seam area 8b, which twists more and more with increasing pressure inside the airbag 11, as well as the development of stress lines radiating outwards from the mechanical fastener 17 and the twisted seam area 8b, which narrows as a result – one such stress line generally extends along the unstwisted area of ​​the circumferential seam area 8b (along which the fastening holes 16 were not fastened inside the roll 13), and another generally extends in a radially opposite direction along the course of the (now unfolded) fold line 6.

[0054] Fig. Figure 14 is another similar view, but shows the airbag 11 in an essentially fully inflated state at maximum inflation pressure. Fig. Figure 15 shows the airbag 11 in the same state, viewed from the front. In this state, the initially visible seam area 8b is hidden and is essentially covered along its entire length by the fabric of the airbag 11 (the course of seam area 8b is shown in Figure 15). Fig. 14 (shown as a dashed line). As can be seen, the same effect is achieved on the opposite seam area 8a on the other side of the airbag 11, which is shown in Fig. 14 is not visible. Fig. Figure 14 also shows the aforementioned primary stress lines, which extend as follows: i) generally along the untwisted portion of the circumferential seam area 8b (along which the fastening holes 16 were not secured within the roll 13), and ii) generally in a radially opposite direction along the course of the (now unfolded) fold line 6 (in the Fig. 14 and Fig. 15 (also shown as a dashed line). Similar to the embodiment described above. Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5. The twist introduced into the circumferential seam areas 8a, 8b of the airbag 11 serves to conceal (and thus protect) the seams of the circumferential seam 8 behind a portion of the airbag 11 material within the twist. This has been shown to reduce gas leakage through the seam 8 and thus improve the integrity of the seam 8.

[0055] While one embodiment of the invention is described above with reference to the Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14 to Fig. 15 (and in particular with reference to Fig. 8) described, in which all diametrically aligned mounting holes 16 of each set incorporated in the roll 13 are connected to each other by a respective fastening means 17, other possibilities of using fastening means 17 to fasten overlapping areas of the airbag 11 within the roll are also conceivable. Fig. Figure 16 illustrates such an example and shows a schematic cross-section through one end of the roll 13 in a similar manner to that in Fig. 8. In this example, however, a fastening means 17 is provided that extends only through a group of radially oriented fastening holes 16 on one side (at A) of the roller 13. The fastening means 17 does not extend through the other group of radially oriented fastening holes 16 on the diametrically opposite side of the roller 13 (at B). In this arrangement, it is therefore evident that the fastening means 17 serves to fasten overlapping areas of the airbag 11 to one another only on one side (A) of the roller 13, so that overlapping areas of the airbag 11 on the diametrically opposite side (B) of the roller 13 are not fastened to one another. This type of arrangement provides a different inflation property of the airbag 11, characterized in that a somewhat looser twist is caused in the seam areas 8a, 8b.

[0056] In Fig. 17 now describes a further embodiment, which is similar to the one described above with reference to the Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15 to Fig. 16 is similar to the embodiment described, wherein the same reference numerals are used to identify identical or equivalent parts or areas.

[0057] Fig. Figure 17 shows a single fabric web 1, which is essentially identical to the one described above with reference to the Fig. The path described in Figure 6 is identical and is represented in a similar folded configuration, comprising a fold 6, in which each half of the path defines a corresponding layer 7a, 7b. As can be seen, the two layers 7a, 7b are thus arranged one above the other (in Fig. In this view, only the top layer 7a is visible (17). As in the Fig. In the arrangement shown in Figure 6, two sets of spaced-apart mounting holes 16 are formed through both layers 7a, 7b, so that each mounting hole 16 extends completely through the airbag 11.

[0058] A significant difference between the in Fig. 17 shown arrangement and the above with reference to Fig. However, the arrangement described in Section 6 concerns the extent of the sewn circumferential seam areas 8a, 8b, which are shown on each side of the folded panel 1. In this proposal, each circumferential seam area 8a, 8b is effectively discontinuous in the sense that it is divided into a respective first section 8a', 8b', which is located on the top side of the folded panel (as shown), and a respective second section 8a'', 8b'', which is located on the bottom side of the folded panel (as shown), with a gap between the two sections along each side of the folded panel 1.

[0059] More precisely, the first section 8a', 8b' of each seam area 8a, 8b extends from the end of the aligned inlet tabs 2 along and adjacent to the edge of the folded web 1 around the first (uppermost, as shown) fastening hole 16 in the manner of a loop (similar to the embodiment described above). Fig. 6) and then extends downwards along and adjacent to the edge of the folded panel 1 before terminating in a further loop around the second adjacent fastening hole 16. Likewise, the second section 8a'', 8b'' of each seam area 8a, 8b begins at the fold 6 and extends upwards along and adjacent to the edge of the folded panel 1 around the lowest fastening hole 16 (i.e., near the fold 6) in the manner of a loop, and then extends further upwards along and adjacent to the edge of the folded panel 1, forming similar loops around the next three (or more, if applicable) adjacent fastening holes 16. Additionally, it should be noted that a loop seam 23 is formed around each of the remaining fastening holes 16 that are not surrounded by loops formed as part of the first and second sections 8a', 8a'', 8b', 8b''.

[0060] As can be seen, the above with reference to Fig. The type of discontinuous seam areas 8a, 8b described in 17 ensures that the inflatable chamber 9 of the resulting airbag is not completely closed by a circumferential seam before being rolled up, with effective venting gaps 24 being formed between adjacent attachment holes 16, which are not enclosed by either the first or second sections 8a', 8a'', 8b', 8b'' of the discontinuous seam areas 8a, 8b.

[0061] It should be noted at this point that in an alternative design of the in Fig. In the embodiment shown in Figure 17, two superimposed layers 7a, 7b can be woven simultaneously on a single loom using a so-called "one-piece weaving" technique, in which the yarns of one of the layers are interwoven with the yarns of the other layer in specific zones to define the circumferential seam areas 8a, 8b and the loop seams 23. In such embodiments, the resulting circumferential seam areas 8a, 8b and the loop seams 23 are woven as integral components of both fabric layers.

[0062] It is proposed that the above-described and in Fig. The partially formed airbag shown in section 17 is subsequently rolled in an essentially identical manner as described above with reference to the Fig. 7, Fig. 8 to Fig. 9, and that the resulting overlapping areas of the airbag 11 are attached to each other in an identical manner via fastening means 17 (or alternatively as above with reference to and as in Fig. (16 shown). However, it can be understood that, since the seam areas 8a, 8b are discontinuous in this embodiment and do not extend over the entire side edges of the folded web 1 before rolling, the second sections 8a'', 8b'' of the peripheral seam areas 8a, 8b within the resulting spirally wound roll 13 may not extend over a complete revolution of the airbag 11 around the roll axis 12 and may therefore form an arc-wound length of the respective peripheral seam area 8a, 8b, instead of, for example, a spirally wound length. In other words, in this embodiment, the overlapping areas of the airbag 11 within the roll 13 can therefore be fastened to one another (by the fastening means) adjacent to a somewhat shorter, arc-wound length of each circumferential seam area 8a, 8b, instead of the longer, spirally wound length of the embodiments described above.

[0063] It has been shown that an airbag configured as described above, with reference to and as described in Fig. 17 shows that, under normal, unimpeded inflation, it functions essentially identically (or at least very similarly) to the airbag described above with reference to and as shown in the Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15 to Fig.As shown in Figure 16, the initially wound lengths of the second sections 8a'', 8b'' of the circumferential seam areas 8a, 8b, along which overlapping areas of the airbag 11 are fastened to one another by the mechanical fasteners 17, are prevented from unwinding. This is sufficient to initiate the introduction of the twist into the second sections 8a'', 8b'' of the circumferential seam areas 8a, 8b. It has been shown that if the second sections 8a'', 8b'' are long enough, the seam twist propagates along the edges of the airbag 11 to cover the areas where the fastening holes 16 are not enclosed by the circumferential seam areas and to effectively close or block the vent gaps 24 formed between them.

[0064] However, in circumstances where the inflation of the airbag 11 is restricted, for example by a so-called "out of position" (OOP) vehicle occupant who is too close to the airbag 11 for safe deployment, the roller 13 is prevented (or at least restricted) from opening at an early stage of deployment, as it quickly encounters the OOP occupant. This prevents or at least reduces the development of the twisting described above in the second sections 8a'', 8b'' of the circumferential seam areas 8a, 8b.This results in the seam twist not spreading sufficiently along the edges of the airbag 11 to cover the areas where the unlooped mounting holes and the vent slots 24 are formed. Consequently, the inflating gas, which continues to be directed into the airbag, escapes through the vent slots 24, thus preventing further inflation of the airbag by opening the roll. In this way, a deflated airbag 11 can be provided that, in the event of an impact on an out-of-pattern (OOP) occupant, will not fully inflate, thereby avoiding or at least reducing the likelihood of injury to the occupant.

[0065] The features disclosed in the foregoing description or in the following claims or in the accompanying drawings, and which are expressed in their specific forms or in the form of a means for fulfilling the disclosed function or a method or process for achieving the disclosed results, can be used individually or in any combination of these features to realize the invention in various forms.

[0066] Although the invention has been described in connection with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art upon reading this disclosure. Accordingly, the exemplary embodiments of the invention described above are considered illustrative and not limiting. Various modifications to the described embodiments can be made without altering the scope of the invention.

[0067] To eliminate any doubt, all theoretical explanations provided herein are intended to aid the reader's understanding. The inventors do not wish to be bound by any of these theoretical explanations.

[0068] Unless otherwise defined herein, scientific and technical terms used in connection with the invention concept(s) disclosed herein shall have the meanings commonly understood by persons skilled in the art.

[0069] All section headings used herein serve only a structuring purpose and are not to be interpreted as a limitation of the subject matter described.

[0070] Reference numerals enclosed in parentheses in the claims are not to be understood as limiting the claim. The word "comprising" does not preclude the presence of elements or steps other than those listed in a claim.

[0071] Throughout this description, including the following claims, unless the context otherwise requires, words such as "include", "comprise" and "include" and variants such as "including", "comprises", "encompassing" and "including" shall be understood to imply the inclusion of a specified 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.

[0072] It should be noted that the singular forms “ein / eine” and “der / die / das”, as used in the description and the attached claims, include plural references unless the context clearly indicates otherwise.

[0073] Unless otherwise stated, terms such as "first" and "second" are used arbitrarily to distinguish between or describe the elements. These terms should therefore not necessarily be understood as indicating any temporal or other prioritization of such elements. The fact that certain measures are mentioned in different claims does not indicate that a combination of these measures cannot be used to one's advantage.

[0074] As can be used herein, any reference to “an embodiment,” “some embodiments,” “an example,” or “for example” means that a specific element, feature, structure, or property described in connection with the embodiment is included in at least one embodiment. The appearance of the phrase “in some embodiments” or “an example” at different points in the description, for instance, does not necessarily refer to the same embodiment. Furthermore, all references to one or more embodiments or examples are to be understood as non-limiting to the claims.

[0075] As used herein, the term "essentially" means that the event or circumstance described below occurs in its entirety, or that the event or circumstance described below occurs to a large extent. For example, in the context of a particular event or circumstance, the term "essentially" means that the event or circumstance described below occurs in at least 80% of cases, or in at least 85% of cases, or in at least 90% of cases, or in at least 95% of cases.For example, the term “substantially adjacent” can mean that two objects are 100% adjacent to each other, or that the two objects are in close proximity to each other but are not 100% adjacent (or neighboring), or that part of one of the two objects is not 100% adjacent (or neighboring) to the other object, but is in close proximity to the other object.

[0076] The terms “preferred” and “preferably” refer herein to embodiments of the invention that may offer certain advantages under specific circumstances. However, it is evident that other embodiments may also be preferred under the same or different circumstances. Therefore, the mention of one or more preferred embodiments does not mean or imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of disclosure or the scope of claims.

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