Dual depth airbag with active venting

An inflatable airbag cushion assembly with a release device for electronic communication with a sensor in a vehicle. The cushion assumes two different configurations depending on the occupant's position. The configurations are achieved via tethers along with closeable vent(s) to control cushion pressure.

TECHNICAL FIELD

The present invention relates generally to the field of automotive protective systems. More specifically, the present invention relates to a system for selectively venting inflation gases from an inflatable passenger side airbag.

INDEX OF ELEMENTS IDENTIFIED IN THE DRAWINGS

DETAILED DESCRIPTION

The phrases “connected to”, “coupled to” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid and thermal interaction. Two components may be coupled to each other even though they are not in direct contact with each other. The phrases “attached to” or “attached directly to” refer to interaction between two or more entities which are in direct contact with each other or are separated by a fastener.

Inflatable airbag systems are widely used to minimize occupant injury in a collision scenario. Airbag modules have been installed at various locations within a vehicle, including, but not limited to, the steering wheel, the instrument panel, within the side doors or side seats, adjacent to roof rail of the vehicle, in an overhead position, or at the knee or leg position. In the following disclosure, “airbag” may refer to an inflatable curtain airbag, overhead airbag, front airbag, or any other airbag type.

Front airbags are typically installed in the steering wheel and instrument panel of a vehicle. During installation, the airbags are rolled, folded, or both, and are retained in the rolled/folded state behind a cover. During a collision event, vehicle sensors trigger the activation of an inflator, which rapidly fills the airbag with inflation gas. Thus the airbag rapidly changes confirmations from the rolled/folded configuration to an expanded configuration.

When an occupant is out of position or seated too closely to a surface from which an airbag will deploy, it is advantageous for an airbag to be deployed to one or more configurations, depending on the position of the occupant within the vehicle. It is also advantageous to be able to vent inflation gas from the airbag to soften it for small occupants and occupants who are out of position.

Some of the embodiments disclosed herein include an airbag assembly comprising one or more closeable vents, at least one closeable vent strap, at least one airbag height restraining tether, at least one airbag depth restraining tether, a release device and a seat-rail sensor. Some or all of these components may be used in combination and in different quantities to provide an airbag assembly, which may be used to provide optimal cushioning for occupants who are out of position, seated close to the panel from which the airbag will deploy, or are seated in a normal manner.

FIG. 1depicts one embodiment of a multi-stage airbag assembly with venting from a side elevation view, in which the airbag assembly is partially cutaway. In this view only one side of the airbag is depicted. A complete airbag assembly may comprise at least two of all the components depicted inFIG. 1. SeeFIG. 3Afor a depiction of an airbag assembly in which both sides can be seen.

In this embodiment, an inflatable cushion airbag assembly100is mounted within an instrument panel15located at the front of a vehicle10. The complete inflatable cushion airbag assembly may comprise an airbag membrane110, one or more airbag depth restraining tethers120, one or more airbag height restraining tethers130, one or more closeable vents140, one or more closeable vent straps150, a release device160, and a seat rail sensor170.

Airbag membrane110is in fluid communication with an inflator (not shown) within instrument panel15. The shape of airbag membrane110depicted inFIG. 1is for illustrative purposes only; the actual shape of airbag membrane110may be any suitable shape.

Release device160may constitute the inflator itself, may be part of the inflator, or release device160may be a mechanism separate from the inflator, such as an actuator commonly known to one skilled in the relevant art. Release device160may be positioned partially within the airbag membrane110and is fixedly coupled to the instrument panel or other vehicle structure.

Airbag depth restraining tether120is fixedly coupled to release device160and may extend to, and be fixedly coupled to, the face-proximal surface of airbag membrane110. Airbag depth restraining tether120may be coupled to release device160via a loop formed by airbag depth restraining tether120, or by a connector, such as a ring, or pin (seeFIG. 5andFIG. 7for a more complete description as to how an airbag depth restraining tether may be coupled to a release device). In one embodiment, airbag depth restraining tether120may comprise 25 mm wide webbing, such as that used in child seats. Airbag depth restraining tether120may be attached to airbag membrane110via stitching, welding, gluing, or any other suitable fastener.

The location of the points at which airbag depth restraining tether120are attached to airbag membrane110inFIG. 1are for illustrative purposes only. In fact, airbag depth restraining tether120may be attached at any suitable position on the face proximal surface of airbag membrane110. Airbag depth restraining tether120may comprise a strip of synthetic woven material, such as nylon, or any other suitable material known to one skilled in the art.

Airbag height restraining tether130may be coupled to airbag depth restraining tether120using a fastener, such as stitching. Since airbag depth restraining tether120may be coupled to release device160, airbag height restraining tether130is also coupled to release device160. Alternatively, airbag height restraining tether130may be coupled to release device160independent of airbag depth restraining tether120(seeFIG. 5andFIG. 7and accompanying text (below) for a description of how an airbag height and an airbag depth restraining tether may be coupled). Airbag height restraining tether130may be coupled to the lap-proximal surface of airbag membrane110via stitching, welding, gluing, or any other suitable fastener. Airbag height restraining tether130may comprise a strip of synthetic woven material, such as nylon, or any other suitable material known in the art. In one embodiment, airbag depth restraining tether120may comprise 25 mm wide webbing, such as that used in child seats.

Closeable vent140may comprise an aperture in airbag membrane110, which is surrounded by a closeable vent. One type of closeable vent that may be used is a cinch tube vent of the type found in U.S. patent application Ser. No. 10/959,256 filed on Oct. 6, 2004, and published as U.S. Patent Publication No. 2006/0071461, which is hereby incorporated by reference. Although airbag assembly100may be deployed to more than one configuration, it may be used with a single stage inflator because of the use of closeable vent140. The use of a single stage inflator reduces the cost of airbag assembly100. The position of closeable vent140on airbag membrane110as shown inFIG. 1is for illustrative purposes only and may be varied to suit different applications. Please seeFIGS. 11A-11Band accompanying text for a complete description of one embodiment of a cinch tube vent.

Closeable vent strap150may be coupled to closeable vent140and extend to the lap-proximal surface of airbag membrane110(seeFIGS. 11A-11Bfor more information on how a closeable vent strap may be coupled to a closeable vent). Closeable vent strap may be of such a length, that when airbag membrane110is deployed to the first configuration, closeable vent strap150is in a relaxed state and when airbag membrane110is deployed to the second configuration, tension is applied to closeable vent strap150.

Closeable vent strap150may be attached to airbag membrane110via stitching, welding, gluing, or any other suitable fastener. Closeable vent strap150may comprise a nylon woven fabric or any other suitable material known in the art. In one embodiment, airbag depth restraining tether120may comprise 25 mm wide webbing, such as that used in child seats.

FIG. 1depicts an occupant20, seated on a seat30, which is positioned relatively close to the instrument panel15, such that a seat rail35is slid forward on seat mount40. A seat rail sensor170may sense the position of seat20by sensing the position of seat rail35on seat mount40. Thus, the for/aft position of occupant20may be detected and electronically communicated to release device160. Seat rail sensor170may be of any type commonly known to one skilled in the art.

In a collision event, vehicle body sensors (not shown) may trigger the activation of an inflator (not shown) which begins to fill airbag membrane110with inflation gas, thereby deploying it from a rolled and/or folded configuration to an extended configuration. Since occupant20is positioned within a predetermined distance from the instrument panel15(as reported by seat rail sensor170) upon deployment of airbag membrane110, release device160does not release airbag depth restraining tether120. Airbag depth restraining tether120is coupled to airbag height restraining tether130such that upon deployment, airbag membrane110is restrained in both its height and depth. This height and depth restrained deployment is termed the “first configuration” and is depicted inFIG. 1.

During the initial stage of airbag deployment closeable vent140may be in an open conformation, since closeable vent strap150is not under tension. As a result of vent140being in an open conformation, if an occupant is out of position and the airbag contacts them prematurely, vent140may vent inflation gas and provide a softer cushion membrane, which may protect the occupant from injury.

Additionally, upon deployment to the first configuration, closeable vent140may remain open due to airbag height restraining tether130restricting how far the lap-proximal surface of airbag membrane110drops toward the lap of occupant20. Since the lap-proximal surface of airbag membrane110does not fully drop, closeable vent strap150does not fully extend and closeable vent140does not restrict inflation gas from venting from the interior of airbag membrane110. As a result, excess inflation gas is vented via closeable vent140.

Thus, the height, depth, and hardness of airbag membrane110are optimized for occupant20, who is positioned within a predetermined distance from instrument panel15and for an occupant who is out of position. Further, small occupants are also optimally cushioned by airbag assembly100, since small occupants typically sit closer to instrument panel15, during a collision event airbag assembly100may deploy to the first configuration, wherein vent140is open, providing a softer cushion for smaller occupants.

FIG. 2depicts airbag assembly100ofFIG. 1deployed to a second configuration, from a side elevation view in which airbag assembly100is partially cutaway. InFIG. 2, the seat of occupant20is further away from instrument panel15than inFIG. 1. Thus, the position seat rail35on seat rail mount40is further away from instrument panel15, as compared toFIG. 1.

The position of the seat of occupant20may be communicated electronically from seat rail sensor170to release device160. If the seat of occupant20is further from instrument panel15than a predetermined distance, during a collision event, release device160may release airbag depth restraining tether120. The release of airbag depth restraining tether120also releases airbag height restraining tether130, since the two tethers may be coupled. Release of airbag height and depth restraining tethers120and130allows airbag membrane110to maximally expand, which configuration is called the “second configuration.”

Expansion of airbag membrane110in the lap-proximal direction eliminates the slack in closeable vent strap150and places tension on closeable vent strap150. This tension causes closeable vent140to be at least partially closed, causing more inflation gas to be retained within airbag membrane110and assuring adequate pressure within airbag membrane110for cushioning occupant20.

FIG. 3Adepicts airbag assembly100ofFIG. 1deployed to the first configuration, from an overhead view, in which airbag assembly100is partially cutaway. In this view, both sides of inflatable cushion airbag assembly100are visible.

Airbag height restraining tether130may be coupled on one end to release device160, and on the other end, tether130may be attached to a split panel180, which is disposed on the lap-proximal surface of airbag membrane110. Airbag height restraining tether130may be attached to the split panel at a predetermined distance from the instrument panel.

Closeable vent strap150may be attached to split panel180at a predetermined distance in the occupant-proximal direction from the attachment of airbag height restraining tethers130. In one embodiment, the center of closeable vent strap150and airbag height restraining tether130may be about one inch (2-4 centimeters) apart. In other embodiments, the distance between the center of closeable vent strap150and the center of airbag height restraining tether130may be configured differently to optimize airbag performance. Airbag height restraining tether130is attached to the split panel nearer the instrument panel than closeable vent strap150. Closeable vent straps150are further coupled to closeable vents140.

Airbag depth restraining tethers120may be coupled to release device160on one end. As best seen inFIGS. 3A-3B, the other end may be attached to the face-proximal surface of airbag membrane110at a plurality of positions.

The position of occupant20is relayed to release device160from seat rail sensor (not shown). InFIG. 3A, occupant20is positioned within a predetermined distance from instrument panel15, such that during a collision event, airbag membrane110may be deployed to the first configuration, wherein release device160does not release airbag depth and height restraining tethers120and130. Since the lap proximal surface of airbag membrane110is restrained, closeable vent straps150do not restrict closeable vents140in their ability to vent inflation gas.

FIG. 3Bis an overhead view of inflatable cushion airbag assembly100ofFIG. 1, wherein the airbag assembly is partially cutaway. In the depiction ofFIG. 3B, airbag assembly100is deployed to the second configuration.

In the depiction ofFIG. 3B, occupant20is further away from instrument panel15, when compared withFIG. 3A. If the seat of occupant20is determined to be further away from instrument panel15than a predetermined distance (as determined by the seat rail sensor (not shown)) during a collision event, release device160may release airbag depth and height restraining tethers120and130.

The release of airbag height restraining tether130allows the lap-proximal surface of airbag membrane110to drop toward the lap of occupant20. As a result, closeable vent strap150is elongated and at least partially closes closeable vent140. The restriction of inflation gas venting through closeable vent140causes more inflation gas to be retained within airbag membrane110, which assures adequate cushioning.

FIG. 4AandFIG. 4Bare side elevation cutaway views of another embodiment of an inflatable cushion airbag assembly deployed to a first configuration and a second configuration, respectively. Inflatable cushion airbag assembly400may comprise an inflatable cushion membrane410, one or more airbag depth restraining tethers420, one or more airbag height restraining tethers430, one or more closeable vents440, one or more closeable vent straps450, and a release device460.

As with inflatable cushion airbag assembly100, inflatable cushion airbag assembly400may be deployed to at least two configurations, and may be used with a single stage inflator. Inflatable cushion airbag assembly400may be mounted in an instrument panel in a vehicle and may be used in combination with a seat rail sensor.

Inflatable cushion airbag assembly400is configured similarly as inflatable cushion airbag assembly100, except that closeable vent strap450is coupled to the airbag depth and height restraining tethers420and430, instead of being attached to the lap-proximal surface of the airbag membrane like the embodiment described with reference toFIG. 1.

When airbag membrane410is deployed to the first configuration, closeable vent strap450is not under tension (FIG. 4A), and thus does not close closeable vent440. When airbag membrane410is deployed to the second configuration, release device460releases airbag depth and height restraining tethers420and430, which puts tension on closeable vent strap450, causing closeable vent440to at least partially close and reduce the rate of gas venting.

FIG. 5is a side elevation detail view of how some of the components of airbag assembly400may be coupled together. The depicted components include closeable vent440, closeable vent strap450, airbag depth restraining tether420, airbag height restraining tether,430.

Closeable vent440is disposed on airbag membrane410. In the embodiment depicted, closeable vent strap450wraps around the circumference of closeable vent440(seeFIGS. 11A-11Bfor additional detail regarding closeable vents). Closeable vent strap450may be coupled to airbag depth restraining tether420via stitching427. Airbag height restraining tethers430may also be coupled to airbag depth restraining tether420via stitching427. Airbag height restraining tethers may comprise a single piece of fabric, or may comprise two separate pieces of fabric as depicted inFIG. 5.

Loop425of airbag depth restraining tether420may be formed by folding a single piece of woven fabric back upon itself and connecting the arms of the free ends by stitching427. Loop425may be used to couple airbag depth restraining tether420(and thus airbag height restraining tether430, closeable vent440, and closeable vent strap450) to a release device (not shown). Alternatively, a ring or pin may be used to couple loop425to a release device.

FIG. 6is a detail view of stitching427as seen from an overhead view. Stitching427is depicted inFIG. 6as a box-stitch. In alternative embodiments, any other suitable fastener, such as staples, pins, welding, or gluing may be used.

FIG. 7depicts another embodiment of coupling some of the components of an airbag assembly like airbag assembly400. Airbag depth restraining tether720may be configured from a single piece of fabric, which is threaded through a rigid planer ring790, folded back upon itself, and connected to itself via stitching725. Airbag height restraining tethers730are also threaded through ring790and sewn to themselves using stitching735. Ring790may be coupled to a release device (not shown). Alternatively, separate rings may be used for airbag depth restraining tether720and airbag height restraining tethers430. Further, one or more closeable vent straps (not shown) may be coupled to airbag height or depth restraining tethers720and730either by sewing to the tethers, by being coupled to a ring to which one of the tethers is coupled, or by being coupled to a separate ring. The rigid planer ring may be manufactured from metal, or any other suitable material.

FIG. 8AandFIG. 8Bare side elevation cutaway views of another embodiment of an inflatable cushion airbag assembly deployed to a first configuration and a second configuration, respectively. Airbag assembly800is configured much like airbag assembly100and is designed to be used in a similar manner. Airbag assembly800may comprise an airbag membrane810, one or more airbag depth restraining tethers820, one or more closeable vents840, one or more closeable vent straps,850and a release device860. Compared to airbag assembly100(FIGS. 1-2), airbag assembly800lacks airbag height restraining tethers and closeable vent strap850is coupled to airbag depth restraining tether820, instead of the lap-proximal surface of the airbag membrane as in airbag assembly100.

FIG. 9AandFIG. 9Bare side elevation cutaway views of another embodiment of an inflatable cushion airbag assembly deployed to a first configuration and a second configuration, respectively. Airbag assembly900is configured much like airbag assembly100and is designed to be used in a similar manner.

In this embodiment, inflatable airbag cushion assembly900may comprise an airbag membrane910, and a release device960, and on each side of the assembly, an airbag depth restraining tether920, two closeable vents,940aand940b, and two closeable vent straps950aand950b. Closeable vent strap950ais coupled airbag restraining tether920, and the other closeable vent strap,950bis coupled to a lap-proximal surface of airbag membrane910as in airbag assembly100. Closeable vent940amay also be called a safety vent, and closeable vent940bmay also be called an active vent.

In the depiction ofFIG. 9AandFIG. 9B, safety vent940aappears to be identical to active vent940b. In other embodiments safety vent940amay be identical to active vent940b, and therefore, their nomenclature may be interchangeable. In other embodiments the vents may be identical, but the attachment points of their respective vent straps may differ. Further, safety vent940amay be larger or smaller, and thus able to vent more or less gas than active vent940b. Additionally, safety vent940amay be a different type of vent than active vent940b.

FIG. 10AandFIG. 10Bare side elevation cutaway views of another embodiment of an inflatable cushion airbag assembly deployed to a first configuration and a second configuration, respectively. Airbag assembly1000is configured much like airbag assembly100and is designed to be used in a similar manner.

In this embodiment, inflatable cushion airbag assembly1000may comprise an airbag membrane1010, a release device1060, and on each side of the assembly, an airbag depth restraining tether1020, an airbag height restraining tether1030, two closeable vents,1040aand1040b, two closeable vent straps1050aand1050b. Closeable vent strap1050ais coupled to airbag depth restraining tether1020, and closeable vent strap1050bis coupled to the lap-proximal surface of airbag membrane1010. Closeable vent1040amay also be called a safety vent, and closeable vent1040bmay also be called an active vent.

In the depiction ofFIG. 10AandFIG. 10B, safety vent1040aappears to be identical to active vent1040b. In other embodiments safety vent1040amay be identical to active vent1040b, and therefore, their nomenclature may be interchangeable. In other embodiments, the vents may be identical, but the attachment points of their respective vent straps may differ. Further, safety vent1040amay be larger or smaller, and thus able to vent more or less gas than active vent1040b. Additionally, safety vent1040amay be a different type of vent than active vent1040b.

FIG. 11AandFIG. 11Bare perspective views of one embodiment of a closeable vent in an open and partially closed configuration, respectively. The depicted closeable vent is a cinch tube vent1140, which may comprise a cinch tube1148with a rim1149. The cinch tube vent is disposed over an aperture in airbag membrane1110. A tether holder such as sleeve1142with holes referred to as sleeve apertures1144may be used to hold a portion of closeable vent strap1150. Closeable vent strap1150is retained within sleeve1142via stitching1146.

Closeable vent1140may be embodied with a generally cylindrical shape. Vent1140may have any suitable shape such as rectangular, triangular, or polygon shapes. The cinch tube may be embodied with a height that is sufficient to achieve desired closure. In one embodiment, the cinch tube has height which is about half of its diameter. Selecting an appropriate height to diameter ratio permits the cinch tube to close during cinching without resistance from cushion membrane tension. The design permits the cinch tube to be a low-stress element in the cushion assembly which is helpful during unfolding of the cushion and pressurization. The cinch tube may comprise a nylon woven fabric-type or other suitable material known in the art.

When tension is applied to closeable vent strap1150(as inFIG. 11B), rim1149may be at least partially drawn together by the portion of closeable vent strap1150that is within sleeve1142. The drawing together of rim1149may at least partially block the escape of inflation gas from the interior of airbag membrane1110via closeable vent1140.

FIG. 12is a top elevation view of another embodiment of an inflatable airbag cushion assembly1200, which is configured to function similarly to the airbag assemblies described above. Assembly1200comprises an airbag membrane1210, an airbag depth restraining tether1220, closeable vents1240, and a release device1260. Closeable vent straps are not shown in this view, but may be configured as those described above or below (seeFIGS. 13A and 13B). Closeable vent straps may be coupled to the closeable vent and extend to and be attached to the airbag depth restraining tethers, a lap-proximal surface of the airbag membrane, or a face-proximal surface of the airbag membrane. Airbag assembly1200constitutes an alternative configuration for coupling airbag depth restraining tethers and a release device, as well as coupling airbag depth and height restraining tethers to a release device. Thus, the configuration of airbag assembly1200may be used with any of the above or below described airbag assemblies.

Airbag depth restraining tether1220may comprise at least three separate pieces of material, an intermediate portion1222, and distal portions1224. Distal portions1224are attached to an intermediate portion via stitching, which may comprise box stitching. Intermediate portion1222and distal portions1224may comprise pieces of nylon webbing. An end portion1226may be attached to release mechanism1260when the airbag assembly is in an undeployed conformation or is deployed to a first configuration, as described above for previous airbag assemblies. Upon deployment to a second configuration, end portion1226may be released, thereby allowing airbag membrane1210to expand and close vents1240by pulling taut vent straps (not shown).

FIGS. 13A and 13Bdepict another embodiment of an inflatable airbag cushion assembly1300from a side elevation cutaway view. Configured to function similarly to the airbag assemblies described above, assembly1300may comprise an airbag membrane1310, airbag depth restraining tethers1320, closeable vents1340aand1340b, vent straps1350aand1350b, and a release device1360.

When deployed to a first configuration, as inFIG. 13A, airbag assembly1300may be restricted in its deployment in the direction of an occupant's torso and lap by airbag depth restraining tethers1320. Release device1360may be directly attached to airbag depth restraining tethers1320or may be coupled to tethers1320via a ring or loop.

As with previous embodiments, the location of closeable vents1340aand1340bdepicted inFIGS. 13A and 13Bis strictly for illustrative purposes and may vary according to different applications. Upon deployment to the first configuration, closeable vents1340aand1340bremain open, because vent straps1350aand1350bare of such a length that they remain slack in the first configuration.

To initiate deployment to a second configuration, release device1360releases airbag depth restraining tethers1320, thus allowing airbag membrane1310to expand beyond the first configuration. Vent straps1350aand1350bare coupled to airbag membrane1310and are of a predetermined length such that during expansion of membrane1310, vent straps1350aand1350bare pulled taut, which in turn, pulls shut closeable vents1340aand1340b.

The position of closeable vents1340aand1340bas depicted inFIGS. 13A and 13Bis strictly for illustrative purposes and may vary according to application. Closeable vent straps1350aand1350bmay comprise pieces of cord, or nylon webbing. Airbag depth restraining tethers1320may comprise nylon webbing.

The airbag membranes110,410,810,910,1010,1110,1210,1310disclosed herein are examples of means for cushioning an occupant of a vehicle during a collision event. The airbag depth restraining tethers120,420,820,920,1020,1220,1320disclosed herein are examples of means for restricting the depth of the expansion of an inflatable cushion airbag. The airbag height restraining tethers130,430,730,1030, disclosed herein are examples of means for restricting the expansion of the height of an inflatable cushion airbag.

Furthermore, the closeable vents140,440,840,940a,940b,1040a,1040b,1140,1240,1340a,1340bdisclosed herein are examples of means for venting inflation gas from the interior of an inflatable cushion airbag. The closeable vent straps150,450,850,950a,950b,1050a,1050b,1150,1350a,1350bdisclosed herein are examples of means for at least partially closing the closeable vents.

Moreover, the release devices160,460,860,960,1060,1260,1360disclosed herein are examples of means for releasing the depth and height restraining tethers. Additionally, the seat rail sensor,170, disclosed herein is an example of means for detecting the for/aft position of an occupant's seat.

Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the present disclosure to its fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and not a limitation to the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure described herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. Note that elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. §112 ¶6. The scope of the invention is therefore defined by the following claims.