Knee Airbag Cushion

Abstract

A knee airbag cushion assembly (100) with an improved internal tether for reshaping deployment. The assembly includes an inflatable cushion (102) and an internal tether (110) with an elongated shaft positioned within the inflatable cushion, the internal tether including a first concave portion attached to a first inner surface of the inflatable cushion and a second concave portion attached to a second inner surface of the inflatable cushion. The first and second concave portions are configured to redirect the expansion of the inflatable cushion upon deployment to form two enlarged deployment regions and a reduced deployment region between the two enlarged deployment regions.

Description

[Technical field]

[0001] Airbag cushions are often configured to provide protection to the knees of a vehicle occupant. However, the contours of this area of ​​the vehicle often present issues that can cause deployment kinematics to be less than ideal. For example, the steering column and / or steering column shroud on the driver's side of the vehicle creates large gaps on either side of the steering column intermediate the driver's knees, the steering column / shroud, and adjacent panels. These gaps can cause many airbag cushions to pivot, deflect, or otherwise function in an undesirable manner. Additionally, many such airbag cushions fail to include features to redirect inflation gases toward and / or provide enhanced size / protection to areas that are more critical for protecting the occupant, such as areas on either side of the steering column that correspond to the expected location of the driver's knees. Summary of the Invention

[0002] Accordingly, the inventors have determined that it would be desirable to provide devices, systems, and methods that overcome one or more of the aforementioned limitations and / or other limitations of the prior art. Thus, in some embodiments, the inventive concepts disclosed herein may enable a driver's side cushion or other cushion to be deployed to provide improved protection to the knees and / or lower legs of a driver or other occupant by limiting / restricting deployment in locations where it is less needed and / or by redirecting inflation gases toward and away from one or more areas that provide better occupant protection. In preferred embodiments, this may be accomplished by providing an internal tether having one or more concave surfaces shaped to enhance the size and / or protective power of the expanded / expanded placement areas on either side of the low profile or reduced deployment area. This effect may be enhanced by providing the tether with vents that redirect inflation gases toward the expanded / expanded deployment areas.

[0003] In a more specific example of a knee airbag cushion assembly according to some embodiments, the airbag cushion assembly may include an inflatable cushion configured to be deployed to provide protection to an occupant's lower extremities during an impact event, such as adjacent a steering column for a vehicle. The inflatable cushion may include an internal tether positioned within and coupled to the inflatable cushion such that a first end of the internal tether is configured to be positioned adjacent a left knee of an occupant during deployment and a second end of the internal tether opposite the first end is configured to be positioned adjacent a right knee of an occupant during deployment. The internal tether may include an upper end extending between the first and second ends, the upper end defining a concave shape positioned and configured to increase the thickness of the inflatable cushion in a region configured to deploy adjacent the knees of an occupant and decrease the thickness of the inflatable cushion in a region configured to deploy adjacent the space between the knees of an occupant.

[0004] In some embodiments, the internal tether may further include a plurality of vent openings formed therein. In some such embodiments, these vent openings may be biased toward the first and second ends to enhance the effect of the concave shape by directing inflation gases toward the region configured to deploy adjacent the occupant's knees. In some such embodiments, the internal tether may be free of vent openings along the region configured to deploy adjacent the space between the occupant's knees.

[0005] In some embodiments, the internal tether can further include a lower end extending between the first end and the second end, the lower end defining a concave shape positioned and configured to increase a thickness of the inflatable cushion in a region configured to deploy adjacent the knees of an occupant and decrease a thickness of the inflatable cushion in a region configured to deploy adjacent the space between the knees of an occupant. In some such embodiments, the upper end extending between the first end and the second end can be sewn to a first inner surface of the inflatable cushion and the lower end extending between the first end and the second end can be sewn to a second inner surface of the inflatable cushion so as to define a cushion thickness therebetween.

[0006] In some embodiments, the internal tether may further include a concave shape extending along the first end and a concave shape extending along the second end. In some such embodiments, the internal tether may not be coupled to the inflatable cushion along the concave shape extending along the first end. Similarly, the internal tether may not be coupled to the inflatable cushion along the concave shape extending along the second end.

[0007] Some embodiments may further comprise one or more additional internal tethers positioned distal to the internal tether relative to the occupant. One or more of these internal tethers may lack the concave surface of the internal tether and / or may comprise a rectangular shape.

[0008] In an example of an airbag cushion assembly according to some embodiments, the assembly may include an inflatable cushion and an internal tether comprising an elongated shaft positioned within the inflatable cushion. The internal tether may include a first concave portion attached to a first inner surface of the inflatable cushion and a second concave portion attached to a second inner surface of the inflatable cushion. The first concave portion and / or the second concave portion may be configured to redirect the inflation of the inflatable cushion upon deployment to form two enlarged deployment regions and a reduced deployment region between the two enlarged deployment regions.

[0009] In some embodiments, the airbag cushion assembly may comprise a knee airbag assembly having two expansion regions configured to deploy adjacent the knees of a vehicle occupant.

[0010] In some embodiments, the internal tether may include multiple vent openings. In some such embodiments, the multiple vent openings may be biased toward both ends of the elongate axis. In some embodiments, the internal tether may lack any vent openings along a central portion of the internal tether that corresponds to the reduced deployment region.

[0011] In some embodiments, the internal tether may further comprise a third concave portion extending along the first end of the elongate shaft and a fourth concave portion extending along the second end of the elongate shaft, hi some such embodiments, neither the third nor the fourth concave portion may be attached to the inflatable cushion.

[0012] In one example of a knee airbag cushion assembly according to some embodiments, the assembly may include an inflatable cushion configured to deploy to provide protection to the knees of a driver or other occupant during an impact event, for example adjacent a steering column for a vehicle. The assembly may further include a plurality of internal tethers configured to modify the deployment characteristics of the inflatable cushion. In some embodiments, at least one of the plurality of tethers includes a pair of opposing concave sides, each of the opposing concave sides being attached to a respective inner surface of the inflatable cushion to reshape the inflatable cushion during deployment. At least one of the plurality of tethers may further include one or more vent openings configured to enhance the reshaping of the inflatable cushion provided by the pair of opposing concave sides.

[0013] In some embodiments, the one or more vent openings may comprise a first vent opening positioned adjacent a first end of at least one of the multiple tethers and a second vent opening positioned adjacent a second end of at least one of the multiple tethers.

[0014] In some embodiments, at least one of the plurality of tethers may lack any vent opening between the first vent opening and the second vent opening.

[0015] In some embodiments, the multiple internal tethers may further comprise at least one internal tether lacking any concave sides. In some such embodiments, the multiple internal tethers may comprise multiple internal tethers lacking any concave sides. In some such embodiments, each of at least one of the multiple tethers with a pair of opposing concave sides may be positioned proximal to each of the multiple internal tethers lacking any concave sides relative to the driver / passenger.

[0016] The features, structures, steps, or characteristics disclosed in this specification in connection with one embodiment may be combined in any suitable manner in one or more alternative embodiments. [Brief description of the drawings]

[0017] Non-limiting and non-exhaustive embodiments of the present disclosure, including various embodiments of the present disclosure, are described with reference to the drawings. [Figure 1] FIG. 1 depicts one embodiment of an internal tether of an airbag assembly, according to some embodiments. [Diagram 2] FIG. 2 illustrates the airbag assembly with the internal tether of FIG. [Diagram 3] FIG. 3 depicts the airbag assembly of FIG. 2 during deployment against the lap of a vehicle occupant. [Figure 4] FIG. 4 depicts the flow of inflation gas during deployment of an airbag assembly, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Detailed descriptions of devices, systems, and methods consistent with various embodiments of the present disclosure are provided below. Although several embodiments are described, it should be understood that the present disclosure is not limited to any of the specific embodiments disclosed, but instead encompasses numerous alternatives, modifications, and equivalents. In addition, although numerous specific details are set forth in the following description to provide a thorough understanding of the embodiments disclosed herein, some embodiments can be practiced without some or all of these details. Moreover, for purposes of clarity, certain technical materials known in the relevant technical field have not been described in detail to avoid unnecessarily obscuring the present disclosure.

[0019] As used herein, the term "substantially" refers to the complete or nearly complete extent or degree of an action, characteristic, attribute, state, structure, item, or result that functions as indicated. For example, an object that is "substantially" cylindrical or "substantially" vertical means that the object / feature is either cylindrical / vertical or nearly cylindrical / vertical so as to provide the same or nearly the same function. The exact degree of permitted deviation provided by this term may depend on the particular context. The use of "substantially" is equally applicable when used in a negative connotation to refer to a complete or nearly complete lack of an action, characteristic, attribute, state, structure, item, or result. For example, a structure that is "substantially free" of a base is either completely devoid of a base or nearly completely devoid of a base such that the effect is substantially the same as if it were completely devoid of a base.

[0020] Similarly, as used herein, the term "about" is used to provide flexibility to the endpoints of numerical ranges by providing that a given value can be "slightly above" or "slightly below" the endpoints while still achieving the function associated with the range.

[0021] The embodiments of the present disclosure may be best understood by referring to the drawings, in which like parts may be designated by like numerals. It will be readily understood that the components of the disclosed embodiments, as generally described and illustrated in the drawings herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the apparatus and method of the present disclosure is not intended to limit the scope of the disclosure, as claimed, but merely represents possible embodiments of the disclosure. In addition, unless otherwise specified, the steps of the method do not necessarily have to be performed in any particular order, or even sequentially, nor do steps have to be performed only once. Further details regarding certain preferred embodiments and implementations will now be described in more detail with reference to the accompanying drawings.

[0022] 1 depicts a tether 110 for use in connection with an airbag cushion assembly, such as a knee airbag assembly, according to some embodiments. Tether 110 is specifically configured for use as an internal tether. In other words, the tether is configured to be positioned within the airbag cushion and, in a preferred embodiment, is configured to control the deployment characteristics / kinematics through a unique design, configuration, placement, and / or coupling within the airbag cushion.

[0023] As shown in this figure, the tether 110 comprises a plurality of concave sides / surfaces / edges. More specifically, the tether 110 comprises opposing sides / edges 112 / 114 that extend along the elongate axis of the tether 110 and define respective concave shapes, and opposing sides / edges 116 / 118 that extend in a direction along and between the elongate axis of the tether 110 and also define respective concave shapes. As discussed in more detail below, at least one of the sides / edges 112 / 114 is preferably concave (and more preferably both). Thus, both embodiments are envisioned in which only one of the sides / edges 112 / 114 is concave, or in which both sides / edges 112 / 114 are concave, but one or both of the sides / edges 116 / 118 are not concave.

[0024] With respect to the sides / edges 116 / 118, it is not essential, but still useful, to form these sides using concave shapes. This is because, in preferred embodiments, only the top and / or bottom edges / sides of the tether 110 are sewn or otherwise attached to the inner surface of the cushion or otherwise bonded within the cushion to the cushion. In contrast, the sides / edges 116 / 118 preferably, but not necessarily, remain unattached to the cushion. However, it may still be preferred in certain embodiments and applications that the shape of the tether 110 is also formed with opposing concave shapes 116 / 118, since stresses on the ends of the seams or other bonding means where the tether 110 is sewn or otherwise bonded to the cushion - i.e., at the opposing ends of the edges 112 and 114 - may be reduced. Thus, it may be useful to provide these shapes on all four sides of the tether 110 to allow the tether 110 to flex more than if straight edges were provided along these sides of the tether 110. However, it should be understood that embodiments are contemplated in which sides 116 and / or 118 are straight or even convex, rather than concave as shown in FIG.

[0025] 1, tether 110 may be formed with one or more vent openings 115. In a preferred embodiment, for example, vent openings 115 are configured to enhance the effect of a concave shape on one or more of the sides / surfaces / edges of tether 110, for example, by directing inflation gases toward an area of ​​a knee airbag system configured to deploy adjacent the knees of an occupant.

[0026] In some embodiments, this enhancement may be provided by biasing the presence of vent openings 115 toward the ends of tether 110, which may correspond to ends between the elongated axis of tether 110 and / or between which tether 110 is sewn or otherwise coupled to an inner surface or other interior region of an airbag cushion. Additionally, it may be preferable to configure internal tether 110 such that there are no vent openings along one or more regions of a knee airbag assembly, such as a region configured to deploy adjacent the space between the knees of an occupant.

[0027] Thus, in the embodiment shown, there are two vent openings 115, one positioned adjacent the end of tether 110 corresponding to edge 116 and the other positioned at the opposite end of tether 110 corresponding to edge 118. Thus, as discussed below and illustrated in subsequent figures, the intermediate portion of tether 110 lacking vent openings may be configured to correspond to and / or be positioned within the area of ​​the airbag cushion to which tether 110 is attached in an attempt to reduce thickness / gas pressure.

[0028] However, it should be understood that numerous alternative embodiments are contemplated. For example, multiple vent openings may be positioned on either side of a central region of the tether that may be devoid of vent openings. In other embodiments, vent openings may be omitted entirely, particularly where the reshaping of the cushion provided by the recessed attachment region of the tether 110 provides sufficient reshaping and / or reconfiguration of the desired airbag deployment kinematics.

[0029] FIG. 2 depicts the inner components of the airbag cushion 102 of the airbag assembly 100. As illustrated in this figure, each of a plurality of tethers is sewn or otherwise coupled within the airbag cushion 102. More specifically, three straight or rectangular tethers 150A / 150B / 150C are coupled within the airbag cushion 102 in adjacent rows. Each of these inner tethers 150A / 150B / 150C includes a plurality of vent openings 155 that may be used to allow inflation gas to pass therethrough during deployment. In the embodiment shown, each of these vent openings 155 is evenly spaced along the length of its respective tether, which may be desirable if an even distribution of inflation gas is desired in this region. However, it should be understood that in some embodiments, one or more of the tethers 150A, 150B, and 150C may have a concave side and / or hourglass shape of the tether 110, if desired. Thus, although the embodiment shown has only one such shaped tether, any number of the tethers, and in some embodiments all of the tethers, may include this shape.

[0030] Although it is not apparent from the figures, it should be understood that the top and bottom sides of each of tethers 150A / 150B / 150C will typically be sewn or otherwise coupled directly to cushion 102. The opposing shorter sides extending between the top and bottom sides are typically not sewn to cushion 102 (although it is contemplated that they may be sewn for certain applications).

[0031] Near the end of the cushion 102 furthest from the inflator (not shown in this view, the inflator is positioned at the rear of the assembly 100 adjacent to internal tether 150C), internal tether 110 is sewn or otherwise attached to the inside of the cushion 102. In embodiments in which the assembly 100 comprises a knee airbag assembly, this area corresponds to the area of ​​the airbag cushion 102 that contacts the knees of the driver or other occupant.

[0032] As mentioned above, at least one of the upper / edge 112 and lower / edge 114, but preferably both, are sewn or otherwise bonded, preferably directly, to the inner surface of the cushion 102. This allows the concave shape of these sides to modify the configuration of the cushion 102 after deployment by creating a low profile region in the middle of the cushion 102, which corresponds to the area between the occupant's knees, thereby shifting inflation gas, cushion thickness / size, and / or protection to adjacent areas on either side of the center, which may be configured to protect the occupant's knees. The presence of vent openings 115 that are biased away from the center of the cushion 102 and / or toward both ends of the elongated axis of the internal tether 110 may enhance the effectiveness of the internal tether 110 by directing inflation gas toward the area configured to deploy adjacent the occupant's knees. Of course, the preferred embodiment comprises a knee airbag assembly / system, but the principles disclosed herein may be applicable to other airbags where it may be desirable to redirect inflation gases to more critical areas to protect particular anatomical areas of the occupant, or to conform to the vehicle structure, for example.

[0033] As mentioned above, it may be preferable to leave the sides 116 and 118 unattached. This may allow inflation gas to bypass the space adjacent the concavity provided by the sides 116 / 118 and may even allow these sides 116 / 118 to flex during deployment. However, it should be understood that embodiments are contemplated in which the sides 116 and / or 118 are straight or even convex rather than concave as shown in FIG. 1. It is further contemplated that in alternative embodiments / applications, the sides 116 / 118 may be sewn or otherwise coupled to the cushion 102 if desired.

[0034] 3 depicts the airbag system 100 after deployment of the cushion 102 adjacent the knees of a vehicle occupant, i.e., the left knee 10A and the right knee 10B. This figure also illustrates the presence of the inflator 105, which in some embodiments may be part of the housing or module. As also shown in this figure, the presence of the internal tether 110, preferably including the concave surface and intentionally offset vent openings 115 described above, results in the formation of a low profile or reduced deployment region 109 that deploys in the area between the occupant's knees 10A / 10B, and a corresponding thicker / larger or enlarged deployment region 108A / 108B, each of which deploys adjacent a respective knee 10A / 10B to provide enhanced protection in the areas that most need this type of airbag assembly.

[0035] The shape of the inflated cushion provided by one or more internal tethers according to the present disclosure, such as internal tether 110, may additionally or alternatively provide other benefits. For example, as also shown in FIG. 3, the low profile or reduced deployment region 109 may provide an angled surface for contacting the driver's or other occupant's knees in conjunction with the enlarged deployment region 108A / 108B to prevent or at least inhibit the knees from sliding off the cushion 102, particularly during oblique impact collisions. Such oblique impacts often generate lateral forces that often result in the knees sliding off of a typical knee airbag cushion, which is usually flat along the side facing the driver / occupant. Thus, by providing an angled surface toward the center of the cushion, the cushion may facilitate the generation of forces against the occupant's knees in one or more directions opposite to the lateral forces that may otherwise result in the knees sliding off the cushion during deployment / impact.

[0036] 4 again depicts the inside of the airbag cushion 102 of the airbag cushion assembly 100 during deployment to illustrate the guided directionality of inflation gas provided by certain preferred embodiments. As shown in this figure, each of the straight / rectangular tethers 150A / 150B / 150C has evenly distributed, non-biased vent openings 155, resulting in a generally uniform distribution of inflation gas in the area closest to the inflator, as indicated by the arrows in the figure.

[0037] However, upon reaching tether 110, the inflation gas migrates through offset openings 115 on the outer region of tether 110 to the opposing outer region of the cushion. This strengthens and amplifies the effect of sewing or otherwise joining opposing concave sides 112 / 114 of tether 110 to cushion 102 to create a reduced deployment region 109 in the front center of the cushion and increased deployment regions 108A / 108B on either side of reduced deployment region 109.

[0038] The foregoing specification has been described with reference to various embodiments and implementations. However, those skilled in the art will appreciate that various modifications and changes can be made without departing from the scope of the present disclosure. For example, the various operational steps, as well as the components for performing the operational steps, may be implemented in various ways depending on the particular application or taking into account any number of cost functions associated with the operation of the system. Thus, any one or more of the steps may be eliminated, modified, or combined with other steps. Furthermore, the present disclosure should be considered in an illustrative rather than limiting sense, and all such modifications are intended to be included within the scope of the present disclosure. Similarly, benefits, other advantages, and solutions to problems have been described above with respect to various embodiments. However, the benefits, advantages, solutions to problems, and any elements that can cause or make any benefit, advantage, or solution to occur should not be construed as critical, necessary, or essential features or elements.

[0039] Those skilled in the art will understand that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention, and the scope of the invention should therefore be determined solely by the claims which follow.

Claims

1. A knee airbag cushion assembly [100] comprising an inflatable cushion [102] configured to deploy to provide protection to the lower extremities of an occupant during an impact event, the inflatable cushion [102] comprising: and an internal tether [110] positioned within and coupled to the inflatable cushion [102] such that a first end of the internal tether [110] is configured to be positioned adjacent to the left knee of the occupant during deployment and a second end of the internal tether [110] opposite the first end is configured to be positioned adjacent to the right knee of the occupant during deployment, the internal tether [110] being coupled to the inflatable cushion [102] such that the first end and the a second end portion extending between the first end portion and the second end portion, the second end portion defining a concave shape positioned and configured to increase a thickness of the inflatable cushion in regions configured to deploy adjacent the knees of the occupant and to decrease a thickness of the inflatable cushion in a region configured to deploy adjacent a space between the knees of the occupant.

2. 2. The knee airbag cushion assembly [100] of claim 1, wherein the knee airbag cushion is configured to be deployed adjacent a steering column for a vehicle, and the internal tether [110] further comprises a plurality of vent openings [115] formed therein, the plurality of vent openings [115] being biased toward the first and second ends to enhance the effect of the concave shape by directing inflation gases toward the region [108A, 108B] configured to be deployed adjacent the knees of the occupant.

3. 3. The knee airbag cushion assembly [100] of claim 1 or 2, wherein the internal tether [110] is free of ventilation openings [115] along the region [109] configured to deploy adjacent the space between the knees of the occupant.

4. 4. The knee airbag cushion assembly [100] of any one of claims 1 to 3, wherein the internal tether [110] further comprises a lower end [114] extending between the first end and the second end, the lower end [114] defining a concave shape positioned and configured to increase a thickness of the inflatable cushion [102] in regions [108A, 108B] configured to deploy adjacent the knees of the occupant and to decrease a thickness of the inflatable cushion [102] in the region [109] configured to deploy adjacent the space between the knees of the occupant.

5. 5. The knee airbag cushion assembly [100] of claim 4, wherein the upper end [112] extending between the first end and the second end is sewn to a first inner surface of the inflatable cushion [102] and the lower end [114] extending between the first end and the second end is sewn to a second inner surface of the inflatable cushion [102] so as to define a cushion thickness therebetween.

6. The knee airbag cushion assembly [100] of any one of claims 1 to 5, wherein the internal tether [110] further comprises a concave shape extending along the first end and a concave shape extending along the second end.

7. 7. The knee airbag cushion assembly of claim 6, wherein the internal tether is not coupled to the inflatable cushion along the concave shape extending along the first end, and the internal tether is not coupled to the inflatable cushion along the concave shape extending along the second end.

8. The knee airbag cushion assembly [100] of any one of claims 1 to 7, further comprising a second internal tether [150A] positioned distal to the internal tether [110] relative to the occupant, the second internal tether [150A] having a rectangular shape.

9. The knee airbag cushion assembly [100] of any one of claims 1 to 8, further comprising a plurality of internal tethers.

10. 10. The knee airbag cushion assembly of claim 9, wherein at least one of the plurality of internal tethers is devoid of any concave sides.

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