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 vehicle occupants. However, the contours of this area of the vehicle often pose problems that can make the deployment kinematics less than ideal. For example, the driver's side steering column and / or steering column shroud of a vehicle create large gaps on both sides of the steering column between the driver's knees, the steering column / shroud, and the adjacent panel. These gaps can allow many airbag cushions to rotate, deflect, or otherwise function in an undesirable manner the driver's legs. Additionally, many such airbag cushions cannot include features for redirecting inflation gas towards, and / or providing enhanced sizing / protection in, areas that are more important for protecting the occupant, such as areas on both sides of the steering column corresponding to the predicted location of the driver's knees.

Summary of the Invention

[0002] Therefore, the inventors have determined that it would be desirable to provide an apparatus, system, and method that overcome one or more of the foregoing limitations and / or other limitations of the prior art. Thus, in some embodiments, the inventive concepts disclosed herein enable a driver's side cushion or other cushion to be deployed to provide improved protection to the knees and / or lower extremities of a driver or another occupant by limiting / restricting deployment in less necessary locations and / or redirecting inflation gas away from such areas and towards one or more areas that provide better occupant protection. In a preferred embodiment, this can be accomplished by providing an internal tether having one or more concave surfaces shaped to enhance the size and / or protective force of an enlarged / expanded deployment area on both sides of a low profile or reduced deployment area. This effect can be enhanced by providing vents in the tether that redirect inflation gas towards the enlarged / expanded deployment area.

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

[0004] In some embodiments, the internal tether may further comprise a plurality of ventilation openings formed within it. In some such embodiments, these ventilation openings may be asymmetrical toward the first and second ends to enhance the effect of the concave shape by directing the expansion gas toward a region configured to deploy adjacent to the occupant's knees. In some such embodiments, the internal tether may not have ventilation openings along the region configured to deploy adjacent to the space between the occupant's knees.

[0005] In some embodiments, the internal tether may further comprise a lower end extending between the first and second ends, the lower end defining a concave shape positioned and configured to increase the thickness of the inflatable cushion in a region configured to deploy adjacent to the occupant's knees and decrease the thickness of the inflatable cushion in a region configured to deploy adjacent to the space between the occupant's knees. In some such embodiments, the upper end extending between the first and second ends may be sewn to the first inner surface of the inflatable cushion, and the lower end extending between the first and second ends may be sewn to the second inner surface of the inflatable cushion, thereby defining the cushion thickness in between.

[0006] In some embodiments, the internal tether may further include a concave shape extending along a first end and a concave shape extending along a 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 include 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 have a rectangular shape.

[0008] In some embodiments of airbag cushion assemblies, the assembly may comprise an inflatable cushion and an internal tether having an elongated shaft positioned within the inflatable cushion. The internal tether may comprise 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 / or second concave portions may be configured to redirect the inflation of the inflatable cushion so that, upon deployment, it forms two expanding deployment regions and a contracting deployment region between the two expanding deployment regions.

[0009] In some embodiments, the airbag cushion assembly may include a knee airbag assembly configured in which two expanding regions are deployed adjacent to the knees of the vehicle occupant.

[0010] In some embodiments, the internal tether may have multiple ventilation openings. In some such embodiments, the multiple ventilation openings may be biased toward both ends of the elongated axis. In some embodiments, the internal tether may lack any ventilation openings along the central portion of the internal tether corresponding to the contraction and unfolding area.

[0011] In some embodiments, the internal tether may further include a third concave portion extending along the first end of the elongated shaft and a fourth concave portion extending along the second end of the elongated shaft. In 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 several embodiments, the assembly may comprise an inflatable cushion configured to deploy to provide protection to the knee of a driver or other occupant during an impact event, for example, adjacent to the steering column of a vehicle. The assembly may further comprise 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 comprises a pair of opposing concave sides, each of which is attached to the respective inner surface of the inflatable cushion to reshape the inflatable cushion during deployment. At least one of the plurality of tethers may further comprise one or more ventilation openings configured to enhance the reshaping of the inflatable cushion provided by the pair of opposing concave sides.

[0013] In some embodiments, one or more ventilation openings may include a first ventilation opening positioned adjacent to a first end of at least one of the plurality of tethers, and a second ventilation opening positioned adjacent to a second end of at least one of the plurality of tethers.

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

[0015] In some embodiments, the plurality of internal tethers may further comprise at least one internal tether lacking any concave side surface. In some such embodiments, the plurality of internal tethers may comprise a plurality of internal tethers lacking any concave side surface. In some such embodiments, each of the plurality of tethers having a pair of opposing concave side surfaces may be positioned proximal to each of the plurality of internal tethers lacking any concave side surface relative to the driver / occupant.

[0016] Features, structures, processes, or properties disclosed herein in relation to one embodiment may be combined in any preferred manner in one or more alternative embodiments. [Brief explanation of the drawing]

[0017] With reference to the drawings, non-limiting and non-exclusive embodiments of the present disclosure, including various embodiments thereof, will be described. [Figure 1] Figure 1 shows one embodiment of the internal tether of an airbag assembly, according to several embodiments. [Figure 2] Figure 2 shows the airbag assembly with the internal tether shown in Figure 1. [Figure 3] Figure 3 shows the airbag assembly from Figure 2 deploying against the vehicle occupant's knee. [Figure 4] Figure 4 shows the flow of inflation gas during the deployment of an airbag assembly in several embodiments. [Modes for carrying out the invention]

[0018] Detailed descriptions of apparatus, systems, and methods consistent with various embodiments of this disclosure are provided below. While several embodiments are described, it should be understood that this disclosure is not limited to any particular embodiment disclosed, but rather encompasses a number of alternative forms, modifications, and equivalents. In addition, while numerous specific details are given in the following description to provide a complete understanding of the embodiments disclosed herein, some embodiments can be implemented without some or all of these details. Furthermore, for clarity and to avoid unnecessarily obscuring this disclosure, certain technical documents known in the relevant art are not described in detail.

[0019] As used herein, the term “substantially” refers to the complete or near-complete degree or extent 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 / characteristic is either cylindrical / vertical or nearly cylindrical / vertical to produce the same or nearly the same function. The exact degree of permissible deviation provided by this term may depend on the specific context. The use of “substantially” is equally applicable when used in a negative implication to refer to the complete or near-complete absence of an action, characteristic, attribute, state, structure, item, or result. For example, a structure that “substantially” lacks a bottom either completely lacks a bottom or nearly completely lacks a bottom to produce substantially the same effect as if the bottom were completely lacking.

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

[0021] Embodiments of the disclosed invention can be best understood by reference to the drawings, and similar parts may be designated by similar numbers. It will be readily apparent that the components of the disclosed embodiments can be arranged and designed in a wide variety of different configurations, as generally described and illustrated in the drawings herein. Accordingly, the following detailed description of embodiments of the apparatus and methods of the disclosed invention is not intended to limit the scope of the disclosure as claimed, but merely to represent 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, nor do they necessarily have to be performed sequentially, nor do the steps have to be performed only once. Further details regarding specific preferred embodiments and implementations are described herein in more detail with reference to the accompanying drawings.

[0022] Figure 1 shows a tether 110 for use in connection with an airbag cushion assembly, such as a knee airbag assembly, according to several embodiments. The tether 110 is configured in particular 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 by 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 side / surface / edge portions. More specifically, the tether 110 comprises opposing side / edge portions 112 / 114 extending along the elongated axis of the tether 110 and defining their respective concave shapes, and opposing side / edge portions 116 / 118 extending in a certain direction and between the elongated axis of the tether 110 and similarly defining their respective concave shapes. As will be discussed in more detail below, at least one of the side / edge portions 112 / 114 is preferably (more preferably both) concave. Thus, embodiments can be conceived in which only one of the side / edge portions 112 / 114 is concave, or in which both of the side / edge portions 112 / 114 are concave, but one or both of the side / edge portions 116 / 118 are not concave.

[0024] With respect to the side / edge portions 116 / 118, it is not essential to use a concave shape to form these sides, but it is still useful. The reason is that in the preferred embodiment, only the upper edge / side and / or the lower edge / side of the tether 110 is stitched or otherwise attached to the inner surface of the cushion or otherwise joined to the cushion within the cushion. In contrast, preferably, but not necessarily, the side / edge portions 116 / 118 remain unattached to the cushion. However, still, in certain embodiments and applications, the shape of the tether 110 may also preferably be formed with opposing concave shapes 116 / 118 because the stress on the ends of the seam or other joining means to which the tether 110 is stitched or otherwise joined to the cushion - that is, at the opposing ends of the edge portions 112 and 114 - can be reduced. Thus, it can be useful to provide these shapes on all four sides of the tether 110 to allow the tether 110 to flex more than if a straight edge were provided along these sides of the tether 110. However, it should be understood that embodiments are contemplated where the sides 116 and / or 118 are not concave as shown in FIG. 1, but are straight, or even convex.

[0025] As also shown in FIG. 1, one or more ventilation openings 115 may be formed in the tether 110. In a preferred embodiment, for example, the ventilation openings 115 are configured to direct inflation gas, for example, toward a region of a knee airbag system configured to deploy adjacent to the occupant's knee, to enhance the effect of one or more of the concave shapes of the side / surface / edge of the tether 110.

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

[0027] Thus, the illustrated embodiment has two ventilation openings 115, one positioned adjacent to the end of the tether 110 corresponding to the edge 116 and the other positioned at the opposite end of the tether 110 corresponding to the edge 118. Thus, as discussed below and illustrated in later figures, the middle portion of the tether 110 lacking ventilation openings can be configured to correspond to and / or be positioned within the region of the airbag cushion to which the tether 110 is attached, with the intent of reducing thickness / gas pressure.

[0028] However, it should be understood that numerous alternative embodiments are contemplated. For example, multiple ventilation openings can be positioned on both sides of a central region of the tether where there may otherwise be no ventilation openings. In other embodiments, the ventilation openings can be completely omitted, particularly when the reshaping of the cushion provided by the concave attachment region of the tether 110 provides sufficient reshaping and / or reconfiguration of the desired airbag deployment kinematics.

[0029] Figure 2 shows the internal components of the airbag cushion 102 of the airbag assembly 100. As illustrated in this figure, each of the multiple tethers is sewn or otherwise joined within the airbag cushion 102. More specifically, three straight or rectangular tethers 150A / 150B / 150C are joined within the airbag cushion 102 in adjacent rows. Each of these internal tethers 150A / 150B / 150C has multiple ventilation openings 155 that can be used to allow inflation gas to pass through during deployment. In the shown embodiment, each of these ventilation openings 155 is evenly spaced along the length of its respective tether, which may be desirable if uniform distribution of inflation gas in this area is desired. However, it should be understood that in some embodiments, one or more of the tethers 150A, 150B, and 150C may have concave sides and / or hourglass shapes of the tether 110, if desired. Therefore, although the shown embodiment has only one such molded tether, any number of tethers, and in some embodiments all tethers, may include this shape.

[0030] Although not evident from the diagram, it should be understood that the top and bottom sides of each tether 150A / 150B / 150C can typically be directly sutured or otherwise joined to the cushion 102. The shorter, opposing sides extending between the top and bottom sides are typically not sutured to the cushion 102 (however, they may be sutured in certain applications).

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

[0032] As described above, preferably both, but at least one of the upper / edge portion 112 and the lower / edge portion 114 is preferably directly sutured or otherwise bonded 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, the low-profile region corresponding to the area between the occupant's knees, thereby allowing the inflation gas, cushion thickness / size, and / or protection to be transferred to adjacent areas on both sides of the center, which can be configured to protect the occupant's knees. The presence of ventilation openings 115 that are biased away from the center of the cushion 102 and / or towards both ends of the elongated axis of the internal tether 110 can enhance the effect of the internal tether 110 by directing the inflation gas toward the area configured to deploy adjacent to the occupant's knees. Naturally, preferred embodiments include a knee airbag assembly / system, but the principles disclosed herein may be applicable to other airbags, which may require redirecting the inflation gas to a more critical area to protect a specific anatomical region of the occupant, or, for example, to conform to the vehicle structure.

[0033] As described above, it may be preferable to leave the sides 116 and 118 unattached. This may allow the expansion gas to bypass the space adjacent to the concave surface provided by the sides 116 / 118, and furthermore, may allow these sides 116 / 118 to flex during deployment. However, it should be understood that embodiments may be conceived in which the sides 116 and / or 118 are linear or even convex, rather than concave as shown in Figure 1. Furthermore, in alternative embodiments / applications, it may also be conceivable that the sides 116 / 118 may be sutured or otherwise joined to the cushion 102, if desired.

[0034] Figure 3 shows the airbag system 100 after the deployment of cushions 102 adjacent to the knees of the vehicle occupant, i.e., the left knee 10A and the right knee 10B. This figure also illustrates the presence of an inflator 105, which may be part of a housing or module in some embodiments. The presence of an internal tether 110, preferably including the concave surface and intentionally offset ventilation opening 115 described above, as also shown in this figure, results in the formation of a low-profile or reduced deployment area 109 that deploys in the area between the occupant's knees 10A / 10B, and corresponding thicker / larger or expanded deployment areas 108A / 108B, each of which deploys adjacent to each knee 10A / 10B to provide enhanced protection in the area where this type of airbag assembly is most needed.

[0035] The shape of the inflated cushion provided by one or more internal tethers according to this disclosure, such as internal tether 110, may further or alternatively provide other benefits. For example, as also shown in Figure 3, a low-profile or reduced deployment area 109 may work in conjunction with the expanded deployment areas 108A / 108B to provide an angled surface for contact with the knee of the driver or other occupant, in order to prevent or at least suppress the knee from slipping out of the cushion 102, particularly during oblique impact collisions. Such oblique impacts often generate lateral forces, which often result in the knee slipping out of a typical knee airbag cushion, which is normally flat along the side facing the driver / occupant. Therefore, by providing an angled surface toward the center of the cushion, the cushion may facilitate the generation of forces on the occupant's knee in one or more directions opposite to the lateral forces that could otherwise result in the knee slipping out of the cushion during deployment / impact.

[0036] Figure 4 again shows the inside of the airbag cushion 102 of the airbag cushion assembly 100 during deployment to illustrate the guided direction of the expansion gas provided by a particular preferred embodiment. As shown in this figure, each of the straight / rectangular tethers 150A / 150B / 150C has evenly distributed, unbiased ventilation openings 155, resulting in a nearly uniform distribution of the expansion gas in the area closest to the inflator, as indicated by the arrows in the figure.

[0037] However, once the expanding gas reaches the tether 110, it moves through the positionally biased opening 115 on the outer region of the tether 110 to the opposing outer region of the cushion. This strengthens and enhances the effect of suturing or otherwise joining the opposing concave sides 112 / 114 of the tether 110 to the cushion 102, creating a contraction expansion region 109 in the front center of the cushion and expanding expansion regions 108A / 108B on both sides of the contraction expansion region 109.

[0038] The aforementioned specification is described with reference to various embodiments and implementations. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of this disclosure. For example, various operating processes and components for performing those processes can 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 processes can be deleted, modified, or combined with other processes. Furthermore, this disclosure should be considered illustrative rather than restrictive, and all such modifications are intended to be within the scope of this disclosure. Similarly, with respect to various embodiments, benefits, other advantages, and solutions to problems have been described above. However, benefits, advantages, solutions to problems, and any elements that can produce or make more prominent any benefits, advantages, or solutions should not be construed as important, necessary, or essential features or elements.

[0039] Those skilled in the art will understand that many modifications can be made to the details of the embodiments described above without departing from the basic principles of the present invention. Therefore, the scope of the present invention should be determined solely by the following claims.

Claims

1. A knee airbag cushion assembly [100] comprising an inflatable cushion [102] configured to deploy to provide protection to the occupant's lower limbs during an impact event, wherein the inflatable cushion [102] The inflatable cushion [102] is positioned within and coupled to the inflatable cushion [102], the inflatable cushion [102] having an internal tether [110] such that a first end of the internal tether [110] is positioned adjacent to the left knee of the occupant during deployment, and a second end of the internal tether [110] opposite to the first end is positioned adjacent to the right knee of the occupant during deployment, the internal tether [110] having an upper end [112] extending between the first end and the second end, the upper end [112] defining a concave shape that increases the thickness of the inflatable cushion [102] in regions [108A, 108B] configured to deploy adjacent to the occupant's knees, and decreases the thickness of the inflatable cushion [102] in regions [109] configured to deploy adjacent to the space between the occupant's knees. The internal tether [110] further comprises an hourglass shape extending along the first end and an hourglass shape extending along the second end, A knee airbag cushion assembly [100] characterized in that the internal tether [110] is not coupled to the inflatable cushion [102] along the hourglass shape extending along the first end, and the internal tether [110] is not coupled to the inflatable cushion [102] along the hourglass shape extending along the second end.

2. The knee airbag cushion assembly [100] according to claim 1, wherein the knee airbag cushion is configured to deploy adjacent to a vehicle steering column, and the internal tether [110] further comprises a plurality of ventilation openings [115] formed therein, the plurality of ventilation openings [115] are offset toward the first and second ends to enhance the effect of the concave shape by directing the expansion gas toward the region [108A, 108B] configured to deploy adjacent to the occupant's knee.

3. The knee airbag cushion assembly [100] according to claim 1, wherein the internal tether [110] has no ventilation openings [115] along the region [109] configured to deploy adjacent to the space between the occupant's knees.

4. The knee airbag cushion assembly [100] according to claim 1, 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 that is positioned and configured to increase the thickness of the inflatable cushion [102] in a region [108A, 108B] configured to deploy adjacent to the occupant's knees, and decrease the thickness of the inflatable cushion [102] in a region [109] configured to deploy adjacent to the space between the occupant's knees.

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

6. The knee airbag cushion assembly [100] according to claim 1, further comprising a second internal tether [150A] positioned distal to the internal tether [110] with respect to the occupant, wherein the second internal tether [150A] has a rectangular shape.

7. The knee airbag cushion assembly [100] according to claim 1, further comprising a plurality of internal tethers.

8. The knee airbag cushion assembly [100] according to claim 7, wherein at least one of the plurality of internal tethers lacks any concave side surface.

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