Dual volume air bag

An air bag module (30) includes an air bag (14) having a deflated condition and an inflated condition and a structure (34) for supporting the air bag. A first tether (106) has a first end connected to the structure via an actuatable fastener (122) and an opposite second end connected to the air bag (14). A second tether (104) having a first end secured to the first tether (106) by a releasable connection (132) at a location between the first and second ends of the first tether. The second tether has a second end connected to a deployable portion of the air bag (14).

FIELD OF THE INVENTION

The present invention relates to an apparatus for helping to protect an occupant of a vehicle. More particularly, the present invention relates to an air bag inflatable between an instrument panel and a front seat occupant of a vehicle.

BACKGROUND OF THE INVENTION

It is known to provide an inflatable vehicle occupant protection device, such as an air bag, for helping to protect an occupant of a vehicle. One particular type of air bag is a frontal air bag inflatable between an occupant of a front seat of the vehicle and an instrument panel of the vehicle. Such air bags may be driver air bags or passenger air bags. When inflated, the driver and passenger air bags help protect the occupant from impacts with parts of the vehicle such as the instrument panel and/or a steering wheel of the vehicle.

Passenger air bags are typically stored in a deflated condition in a housing that is mounted to the vehicle instrument panel. An air bag door is connectable with the housing and/or instrument panel to help enclose and conceal the air bag in a stored condition. Upon deployment of the passenger air bag, the air bag door opens to permit the air bag to move to an inflated position. The air bag door opens as a result of forces exerted on the door by the inflating air bag.

Driver air bags are typically stored in a deflated condition in a housing that is mounted on the vehicle steering wheel. An air bag cover is connectable with the housing and/or steering wheel to help enclose and conceal the air bag in a stored condition. Upon deployment of the driver air bag, the air bag cover opens to permit the air bag to move to an inflated position. The air bag cover opens as a result of forces exerted on the cover by the inflating driver air bag.

SUMMARY OF THE INVENTION

The present invention relates to an air bag module that includes an air bag having a deflated condition and an inflated condition and a structure for supporting the air bag. A first tether has a first end connected to the structure via an actuatable fastener and an opposite second end connected to the air bag. A second tether having a first end secured to the first tether by a releasable connection at a location between the first and second ends of the first tether. The second tether has a second end connected to a deployable portion of the air bag.

The present invention also relates to an apparatus for helping to protect an occupant of a vehicle. The apparatus includes an inflatable vehicle occupant protection device having a deflated condition and an inflated condition. A first tether has a first segment comprising an anchor tether that is secured to the vehicle and a second segment comprising a trigger tether. A second tether includes a shaping tether secured to a portion of the protection device. A releasable connection connects the second tether to the first tether at a location on the first tether where the segments meet. An actuatable device secures the trigger tether to the vehicle so that the trigger tether becomes tensioned by the shaping tether due to deployment of the protection device. The trigger tether, when tensioned, ruptures the releasable connection, which disconnects the shaping tether from the anchor tether and thereby permits the portion of the protection device to deploy uninhibited. The actuatable device is actuatable to release the trigger tether so that the releasable connection maintains the connection between the anchor tether and the shaping tether. The anchor tether and shaping tether in combination restrict deployment of the portion of the protection device.

The present invention further relates to an apparatus for helping to protect an occupant of a vehicle. The apparatus includes an inflatable vehicle occupant protection device having a deflated condition and an inflated condition. An adaptive tether selectively shapes the air bag and a vent selectively releases inflation fluid from the air bag. The vent includes a vent tether for actuating the vent. An actuatable device secures the adaptive tether and the vent tether to the vehicle. The actuatable device is selectively actuatable to place the protection device in one of three different inflated conditions.

DETAILED DESCRIPTION OF THE INVENTION

An apparatus10for helping to protect an occupant20of a vehicle12includes an inflatable vehicle occupant protection device14in the form of an air bag. In the embodiment illustrated inFIG. 1, the air bag14is a passenger frontal air bag for helping to protect an occupant20of a seat22on a passenger side24of the vehicle12.

The air bag14may be part of an air bag module30that includes an inflator32and a support or housing34for the air bag and inflator. The air bag14has a stored condition, indicated by dashed lines inFIG. 1, in which the air bag is folded and placed in the housing34. The module30is mounted to a dash or instrument panel36of the vehicle12. The housing34helps contain and support the air bag14and inflator32in the instrument panel36.

An air bag door40is releasably connected to the instrument panel36and/or the housing34. In a closed condition (not shown), the air bag door40forms a cover for the module30and helps enclose the air bag14in the stored condition in the housing34. The door40is movable to an opened condition illustrated inFIG. 1to uncover an opening44through which the air bag14may be deployed from the stored condition in the housing34. The door40may be connected to the vehicle12, e.g., the instrument panel36, either directly or through the housing34, by means (not shown), such as a plastic hinge portion, a strap, or a tether.

The inflator32is actuatable to provide inflation fluid to an inflatable volume54of the air bag14to deploy the air bag to the inflated condition. The inflator32may be of any known type, such as stored gas, solid propellant, augmented, or hybrid. The apparatus10also includes a sensor/controller, illustrated schematically at50, for sensing an event for which inflation of the air bag14is desired, such as a collision, and providing an actuation signal to the apparatus10in response to the sensed event. The inflator32is operatively connected to the sensor/controller50via lead wires52.

The air bag14can be constructed of any suitable material, such as nylon (e.g., woven nylon 6-6 yarns), and may be constructed in any suitable manner. For example, the air bag14may include one or more pieces or panels of material. If more than one piece or panel is used, the pieces or panels may be interconnected by known means, such as stitching, ultrasonic welding, heat bonding, or adhesives, to form the air bag. The air bag14may be uncoated, coated with a material, such as a gas impermeable urethane, or laminated with a material, such as a gas impermeable film. The air bag14thus may have a gas-tight or substantially gas-tight construction. Those skilled in the art will appreciate that alternative materials, such as polyester yarn, and alternatives coatings, such as silicone, may also be used to construct the air bag14.

Upon sensing the occurrence of an event for which inflation of the air bag14is desired, such as a vehicle collision, the sensor50provides a signal to the inflator32via the lead wires52. Upon receiving the signal from the sensor50, the inflator32is actuated and provides inflation fluid to the inflatable volume54of the air bag14in a known manner. The inflating air bag14exerts a force on the door40, which moves the door to the opened condition. The air bag14inflates from the stored condition to a deployed condition, such as the fully inflated and deployed condition illustrated in solid lines inFIG. 1. The air bag14, while inflated, helps protect the vehicle occupant20from impacts with parts of the vehicle12, such as the instrument panel36.

The air bag14may have one or more actuatable features for helping to control or tailor inflation of the air bag in response to vehicle conditions, occupant conditions, or both. These features may be actuatable actively, for example, in response to conditions determined via active sensors, or passively, for example, having a configuration responsive to physical conditions at the time of inflation and deployment. Examples of such actuatable features are illustrated inFIGS. 2-5.

Referring toFIGS. 2-5, the air bag14includes an adaptive tether100for adapting the configuration of the air bag14depending on vehicle conditions, occupant conditions, or a combination of vehicle and occupant conditions at the time of the occurrence of the event for which inflation and deployment of the air bag is triggered. The adaptive tether100is a three-leg tether that includes a portion comprising an anchor tether102, a portion comprising a shaping tether104, and a portion comprising a trigger tether106. In this configuration, the anchor tether102and trigger tether106are segments of a first length of tether material, and the shaping tether104is its own separate second length of tether material.

The anchor tether102has a first end portion110anchored to the vehicle. Anchoring the anchor tether102to the vehicle12could be achieved in a many different manners. The anchor tether102could, for example, be secured to the air bag14(e.g., a rear panel of the air bag) or to structure of the vehicle12, such as the air bag module30(e.g., the housing34) or the instrument panel36. In the embodiment illustrated inFIGS. 2-5, the anchor tether is secured to the air bag14at a location near a mouth portion90of the air bag where the bag is secured to the housing34.

The shaping tether104has a first end portion112secured to a panel, such as a front panel114, of the air bag14. This connection can be established by known means, such as stitching or ultrasonic welding. In the embodiment illustrated inFIGS. 2-5, the first end portion112of the shaping tether104is connected to an upper portion116of the front panel114of the air bag14. Those skilled in the art will appreciate that the shaping tether104could be connected to the air bag14at a different location.

The trigger tether106has a first end portion120secured to a support structure in the vehicle12, such as the housing34, by an actuatable device122. The actuatable device122may, for example, be an actuatable fastener, such as a pyrotechnic bolt, that is actuatable to break or release the connection of the first end portion120of the trigger tether106to the housing34. Those skilled in the art will appreciate that alternative devices122could be utilized in this application. For example, the actuatable device may comprise an actuatable latch, a solenoid mechanism, or actuatable cutters or shears.

In an unactuated condition of the adaptive tether100, the anchor tether102, shaping tether104, and trigger tether106are interconnected. This is shown in detail inFIGS. 4 and 5. As shown inFIG. 4, the anchor tether102and trigger tether106are segments of a single length of tether material130. The shaping tether104is a separate length of tether material. A releasable connection132interconnects the shaping tether104to the tether material130at or near the interface between the anchor tether102and trigger tether106. In the illustrated embodiment, the releasable connection132comprises releasable tear stitching. The releasable connection132could, however, have alternative connection or construction. For example, the releasable connection132could comprise a releasable bonding agent, such as an adhesive or tape, or a releasable mechanical device, such as a rivet or staple.

According to the present invention, a rupturable tear stitch configuration that promotes predictability, repeatability, and reliability in releasing interconnected fabrics is used to form the tear stitching132.FIGS. 4 and 5illustrate by way of example tear stitching132in accordance with the present invention. Referring toFIGS. 4 and 5, the tear stitching132has an inverted V-shaped configuration with outwardly diverging segments134or legs that meet at a break point136. Terminal end portions138of the segments134have an inwardly curved configuration that terminates short of intersecting its associated segment.

The tear stitching132is configured to rupture in response to the tension applied to the shaping tether104and the trigger tether106during deployment of the air bag14. According to the present invention, the tear stitching132is adapted to release the connection between the anchor tether102and the shaping tethers104depending on conditions in the vehicle12when the air bag14is deployed.

The air bag14and adaptive tether100are constructed and arranged such that the amount of tension sufficient to rupture the tear stitching differs between the shaping tether104and trigger tether106. Tension applied to the tear stitching132by the shaping tether104acts generally parallel to the anchor tether102. This helps distribute the tension force over the end portions138and segments134of the tear stitching132. The tear stitching132may thus offer a relatively high resistance to rupture in response to tension applied by the shaping tether104and anchor tether102(referred to herein as “shaping strength”).

Tension applied to the tear stitching132by the shaping tether204and trigger tether106acts at an angle to the anchor tether102(seeFIG. 4) and thus produces a “peeling” force or action between the trigger tether106and the shaping tether104. This peeling action helps focus the tension on the break point136of the tear stitching132. Peeling force depends on pulling the trigger tether106back along the stitching132and the stitched portion of the anchor tether102. Ideally, tension pulling the trigger tether106parallel to the anchor tether102and the plane of the stitching132produces a pulling force that is the strongest and the most focused on the break point136. Tension pulling the trigger tether106substantially in this direction, as shown for example inFIG. 4, can provide a peeling force that is sufficiently strong and focused.

Due to the strength and focusing properties of the peeling force applied by the trigger tether106, the tear stitching132may thus offer a relatively lower resistance rupture in response to tension applied by the shaping tether104and trigger tether106(referred to herein as “trigger strength”). The adaptive tether100thus may have a relatively high shaping strength and a correspondingly low trigger strength.

Because of this, the rupture strength of the tear stitching132may be selected to have a desired combination of shaping and trigger strengths. This can be achieved, for example, through the careful selection of the thread material, stitch pattern, number of stitches, and/or thread pattern. For instance, in one embodiment, the tear stitching132may have a trigger strength selected such that the tear stitching ruptures in response to a force of about 100 Newtons applied via the shaping tether104and trigger tether106. In contrast, this same tear stitching132may also have a shaping strength selected such that the tear stitching is capable of withstanding a force of about 2000 Newtons applied via the shaping tether104and anchor tether102.

According to the present invention, the segment of the tether130forming the trigger tether106has a length that is shorter than the length of the segment of the tether forming the anchor tether102. Due to this configuration, those skilled in the art will appreciate that, in response to deployment of the air bag14, tension will be applied to the tear stitching132by the trigger tether106and the shaping tether104. This is the case, of course, as long as the connection between the trigger tether106and the housing34is maintained by the actuatable fastener122.

If the actuatable fastener122remains unactuated and maintains the connection of the trigger tether106to the housing34, then tension is applied to the tear stitching132by the shaping tether104and trigger tether106, due to the trigger tether being shorter than the anchor tether102. As a result, the peeling action focuses the tension on the break point136. When the tension on the trigger tether106exceeds the trigger strength, the tear stitching132ruptures beginning at the break point136. The rupture then travels along the curved segments134until the trigger tether106and shaping tether104are released from each other.

If the actuatable fastener122is actuated and releases the connection of the trigger tether106to the housing34, then tension is applied to the tear stitching132by the shaping tether104and anchor tether102, since the trigger tether106is no longer anchored to the vehicle. As a result, the connection between the shaping tether104and anchor tether102relies on the shaping strength of the tear stitching132. The shaping strength of the tear stitching132may preferably be configured to withstand the force of inflation and deployment of the air bag14. As a result, the shaping tether104and anchor tether102combine to restrict deployment of the air bag14, particularly the front panel114, and thereby restrict or limit the air bag14to the desired shape.

The shaping strength and trigger strength of the tear stitching132can be tailored to desired values through a variety of configurable characteristics. For example, the material used to construct the tear stitching132may be selected to have material properties that help provide the desired shaping and tear strengths. Also, stitching itself (i.e., stitches per inch, type of stitch) may be selected to have material properties that help provide the desired shaping and tear strengths. Further, the shape of the tear stitching132may differ from the V-shaped configurations illustrated inFIGS. 4 and 5and may be selected to have material properties that help provide the desired shaping and tear strengths.

When an event occurs which inflation of the air bag14is desired, the adaptive tether100respond to vehicle conditions, occupant conditions, or both to help control inflation and deployment of the air bag. According to the embodiment ofFIGS. 2-5, this control is implemented actively based on sensed conditions in the vehicle12. To achieve this function, the apparatus10also includes a controller, illustrated schematically at140, for actuating the actuatable fastener122. The controller140is operatively connected to the actuatable fastener122via lead wires142. Upon the occurrence of an event for which inflation of the air bag14is desired, such as a collision, the controller140determines whether to actuate the actuatable fastener based on vehicle conditions, occupant conditions or both vehicle and occupant conditions at the time of the sensed event.

The controller140is also operatively connected to sensors that provide signals that the controller can use to infer or determine the vehicle/occupant conditions. For example, as shown inFIGS. 2 and 3, the apparatus10may include one or more sensors144that can provide a signal to the controller140via lead wires142that is indicative of a sensed seat position, a sensed weight on the vehicle seat22, a sensed presence of an occupant20on the vehicle seat, or a combination of these conditions. Through the controller140and sensors144, the apparatus10may, for example, be adapted to respond to the size or position of the vehicle occupant20.

Referring toFIG. 2, the occupant20is positioned relatively close to the instrument panel36and therefore relatively dose to the air bag module30. This may be the case, for example, with a relatively small occupant, such as a child or small female occupant. For reference, a large occupant20′ such as an average size or large adult male is illustrated in dashed lines. Those skilled in the art will appreciate that the smaller occupant20may adjust the vehicle seat22to a position forward of the seat22′ of the larger occupant20′. The smaller occupant20may also place less weight on the vehicle seat22.

According to the present invention, upon sensing the forward positioned occupant20and in response to sending the event for which occupant protection is desired, the controller140actuates the actuatable fastener122, which disconnects the trigger tether106from being connected/anchored to the housing34. As a result, the trigger tether106does not apply any tension or force on the tear stitching132(seeFIGS. 4 and 5). Because of this, the shaping tether104and anchor tether102become tensioned by the deploying front panel114of the air bag14. When this occurs, the tension in the shaping tether104and anchor tether102is applied to the tear stitching132, which connects the two tethers.

Since, as described above, the tear stitching132has a relatively high shaping strength configured to withstand relatively high tension forces between the shaping tether104and the anchor tether102, the tear stitching does not rupture in the event of the forward positioned occupant ofFIG. 2. The shaping tether104thus helps maintain the shape of the air bag illustrated inFIG. 2. Those having skill in the art will appreciate that the shaping tether104helps maintain the upper portion116of the front panel114positioned away from the forward positioned occupant's head.

Referring toFIG. 3, the occupant20is positioned away from the instrument panel36and therefore relatively far from to the air bag module30. This may be the case, for example, with a relatively large occupant, such as an adult male occupant. For reference, a small occupant20′ such as a child or small female occupant in a forward seat position is illustrated in dashed lines. Those skilled in the art will appreciate that the larger occupant20may adjust the vehicle seat22to a position rearward of the seat22′ of the smaller occupant20′. The larger occupant20may also place more weight on the vehicle seat22than the small occupant22.

According to the present invention, upon sensing the rearward positioned occupant20and sensing the occurrence of an event for which occupant protection is desired, the controller140blocks actuation of the actuatable fastener122, which maintains the connection between the trigger tether106and the housing34. As a result, the trigger tether106remains anchored in the vehicle12and therefore applies a tension or force on the tear stitching132(seeFIGS. 4 and 5). Because of this, the trigger tether106becomes tensioned under the force of the deploying front panel114and the trigger tether106applies a significant tension or force on the tear stitching132.

Since, as described above, the tear stitching132has a relatively low trigger strength configured to rupture under relatively low tension forces between the trigger tether106and the anchor tether102, the tear stitching ruptures in the event of the rearward positioned occupant ofFIG. 3. This releases the connection between the anchor tether102and the shaping tether104. As a result, the shaping tether104does not maintain the shape of the air bag14and the air bag is permitted to inflate to the fully deployed position illustrated inFIG. 3.

In view of the above, those skilled in the art will appreciate that, according to the present invention, the adaptive tether100shapes or restricts deployment of the air bag14in the event of a forward positioned occupant and permits full deployment in the event of a rearward positioned occupant. Those skilled in the art will also appreciate that the adaptive function of the tether100is not limited to forward/rearward occupant position per se. For example, the adaptive tether100could function similarly to shape or restrict deployment of the air bag14in the event of a child safety seat positioned on the vehicle seat22as determined, for example, via a seatbelt tension sensor operatively connected to the controller140. As another example, the adaptive tether100could function similarly to shape or restrict deployment of the air bag14in the event of an extremely large occupant, without regard to the forward/rearward position of the seat22, based on the sensed weight on the seat. As a further example, the adaptive tether100could function similarly to shape or restrict deployment of the air bag14in the event of an occupant positioned away from a normal seating position, such as a leaned-over or leaned-forward position, without regard to the forward/rearward position of the seat22and without regard to the occupant's size, as determined by an occupant position sensor operatively connected to the controller140. Additionally, while the adaptive tether100is illustrated as controlling the inflated depth of the air bag14, the tether could be configured to control other dimensions, such as the inflated width or height, of the air bag14.

A second embodiment of the present invention is illustrated inFIGS. 6 and 7. Certain components inFIGS. 6 and 7are similar or identical to components ofFIGS. 2-5. The suffix “a” is added to the reference numbers of these similar or identical components inFIGS. 6 and 7to avoid confusion. The apparatus10aof the second embodiment includes an air bag module30acomprising an air bag14a, a housing34a, and an inflator32a.

In the embodiment ofFIGS. 6 and 7, the apparatus10aalso includes an adaptive tether150that shapes the air bag14ain the same manner as described above in regard to the apparatus ofFIGS. 2-5. The adaptive tether150therefore includes a portion comprising an anchor tether152, a portion comprising a shaping tether154, and a portion comprising a trigger tether156. Additionally, according to the embodiment ofFIGS. 6 and 7, the air bag14aalso includes a vent160that is selectively actuatable to release inflation fluid from the inflatable volume of the air bag14a. In this embodiment, the adaptive tether150, in addition to the shaping functions, also comprises a vent tether158that is operative to actuate the vent160in response to vehicle and occupant conditions at the time the air bag is deployed. The vent160thus may selectively release inflation fluid from the air bag14adepending on these conditions.

The vent160may have various configurations. In the embodiment illustrated inFIGS. 6 and 7, the vent160includes one or more vent openings162formed in a panel164, such as a side panel, of the air bag14a. A vent door166is secured to the side panel164. The vent tether158has a first end portion secured to the vent door166and a second end portion secured to a panel of the air bag14a, such as the front panel114aof the air bag. The second end portion may be connected to the air bag14aat a location at or near the location where the shaping tether156is connected to the air bag. For example, in the embodiment illustrated inFIGS. 6 and 7, the second end portion is connected to the front panel114aat the same location where the shaping tether156is secured to the front panel114a.

The vent door166is secured to the panel164by known means (not shown), such as stitching, ultrasonic welding, heat bonding, or adhesives. The vent160has an open condition (FIG. 6) in which the vent door166is positioned away from the vent openings162and thereby permits inflation fluid to vent, i.e., flow, through the vent openings. In the open condition, the vent door166is folded away from the vent openings162and held in place by a releasable tear stitch176.

The air bag14a, vent160, and adaptive tether150are constructed and arranged to adapt to vehicle and occupant conditions in the vehicle12aat the time the air bag is deployed. The anchor tether152, shaping tether154, trigger tether156, and actuatable fastener122aof the embodiment ofFIGS. 6 and 7are identical to those of the embodiment ofFIGS. 2-5. Therefore, the adaptive tether150of the second embodiment is operative to shape or restrict deployment of the air bag14ain the event of a forward positioned occupant and permits full deployment of the air bag in the event of a rearward positioned occupant. The adaptive tether150of the second embodiment achieves this function via operation of the anchor tether152, shaping tether154, trigger tether156and actuatable fastener122ain a manner that is identical to the corresponding tethers and fastener shown inFIGS. 2-5and described above.

The vent tether158is constructed and arranged to adapt to selectively actuate the vent160in response to vehicle and occupant conditions in the vehicle12aat the time the air bag14ais deployed. Since the vent tether158is connected to the vent door166and to the air bag14aat a location at or near the location where the shaping tether156is secured to the air bag14a, the vent tether can be adapted to respond to whether or not the shaping tether shapes the air bag. As described above, whether the shaping tether156shapes the air bag14adepends on whether the actuatable fastener122areleases the shaping tether from its connection with the housing34aof the air bag module30a. Therefore, whether the vent tether158actuates the vent160also depends on whether the actuatable fastener122areleases the shaping tether from its connection with the housing34aof the air bag module30a.

Actuation of the actuatable fastener122adepends on sensed vehicle and/or occupant conditions in the vehicle, as described above in regard to the embodiment ofFIGS. 2-5. Essentially, the actuatable fastener122ais actuated in response to a forward positioned occupant and remains unactuated in response to a rearward positioned occupant. Other factors, such as the presence of a child safety seat, an extremely large occupant, or an occupant positioned away from a normal seating position may also help to determine whether to actuate the fastener122a. Therefore, actuation of the vent160is also dependent on these factors.

Referring toFIG. 6, the occupant20ais a forward positioned occupant, such as a small female. In this event, the actuatable fastener122ais actuated so that the trigger tether is released and the shaping tether156shapes the air bag14a, restricting the front panel114afrom reaching the fully deployed condition. In doing so, this prevents the vent tether158from actuating the vent160. Since, in the embodiment ofFIGS. 6 and 7, the vent160has a normally open configuration, its non-actuation results in the vent remaining open. Therefore, in the case of the forward positioned small occupant20a, the vent160vents inflation fluid from the air bag14a.

Referring toFIG. 7, the occupant20ais a rearward positioned occupant, such as a large male. In this event, the actuatable fastener122aremains unactuated so that the trigger tether156releases the connection between the anchor tether152and the shaping tether154. As a result, the front panel114ais released to reach the fully deployed condition. In doing so, this also permits the vent tether158to actuate the vent160. Since, in the embodiment ofFIGS. 6 and 7, the vent160has a normally open configuration, its actuation results in the vent being placed in the closed condition. Therefore, in the case of the rearward positioned large occupant20a, the vent160blocks inflation fluid venting from the air bag14a.

In view of the above, those skilled in the art will appreciate that, according to the present invention, the adaptive tether150is configured cause inflation fluid venting in response to restricted deployment of the air bag14a, and is configured to block inflation fluid venting in response to full deployment of the air bag. Those skilled in the art will appreciate that the adaptive tether150and vent160could be arranged such that the reverse is true, i.e., such that inflation fluid vents in response to full deployment and inflation fluid venting is blocked in response to restricted deployment. A vent configuration that could be used for this purpose is illustrated inFIGS. 8 and 9.

Additionally, those skilled in the art will appreciate that the vent160may provide an additional function for helping an occupant positioned away from the normal seating position. This may be the case, for example, where the large occupant20aofFIG. 7is positioned leaned forward adjacent or near the instrument panel36a. In this instance, even though the trigger tether156releases the shaping tether154, the leaned forward occupant20amay impede deployment of the air bag14a. As a result, the occupant20amay also prevent the air bag from tensioning the vent tether158and actuating the vent160. Thus, in the case of this out of position occupant, the air bag14ais adapted to vent inflation fluid via the vent160even though the trigger tether156releases the shaping tether154.

Referring toFIGS. 8 and 9, according to a third embodiment of the invention, a vent200for venting inflation fluid from the air bag14acomprises a vent door202and a vent opening204in a panel206of the air bag, such as a side panel. The vent door202is secured to the panel206by a releasable connection210, such as tear stitching or an adhesive. In the embodiment ofFIGS. 8 and 9, the vent door202is secured to the panel206by tear stitching210. The portion of the adaptive tether150comprising the vent tether158is secured to a tapered end portion212of the vent door202and extends along the vent door across the vent opening204to its connection (not shown) with the air bag14a. The connection of the vent tether158with the air bag14amay be similar or identical to that shown and described in the embodiment ofFIGS. 6 and 7.

The vent200ofFIGS. 8 and 9has a normally closed construction. Therefore, when the occupant is a forward positioned occupant and the actuatable fastener is actuated so as to shape the bag as described above in regard toFIGS. 2-7, the vent tether158is prevented from actuating the vent200. Since, in the embodiment ofFIGS. 8 and 9, the vent200has a normally closed configuration, its non-actuation results in the vent remaining closed. Therefore, in the case of the forward positioned small occupant, the vent200blocks inflation fluid from venting inflation fluid from the air bag14a.

Referring toFIG. 9, when the occupant is a rearward positioned occupant and the actuatable fastener remains unactuated so as to permit the air bag14ato fully inflate and deploy as described above in regard toFIGS. 2-7, the vent tether158actuates the vent200. Since, in the embodiment ofFIGS. 8 and 9, the vent200has a normally closed configuration, its actuation results in the vent being pulled open, as shown inFIG. 9. Therefore, in the case of the rearward positioned large occupant, the vent200vents inflation fluid from the air bag14a.

In view of the above, those skilled in the art will appreciate that, according to the present invention, the adaptive tether150is configured to block inflation fluid venting in response to restricted deployment of the air bag14a, and is configured to permit inflation fluid venting in response to full deployment of the air bag.

A fourth embodiment of the present invention is illustrated inFIGS. 10-15. Certain components inFIGS. 10-15are similar or identical to components ofFIGS. 2-9. The suffix “b” is added to the reference numbers of these similar or identical components inFIGS. 10-15to avoid confusion. Referring toFIGS. 10-12, the apparatus10bof the second embodiment includes an air bag module30bcomprising an air bag14b, a housing34b, and an inflator32b.

In the embodiment ofFIGS. 10-12, the apparatus10balso includes an adaptive tether250that shapes the air bag14bin a manner similar to that described above in regard to the apparatus ofFIGS. 2-9. The adaptive tether250includes a portion comprising an anchor tether252, a portion comprising a shaping tether254, and a portion comprising a trigger tether256. Additionally, according to the embodiment ofFIGS. 10-12, the air bag14balso includes a vent260that is selectively actuatable to release inflation fluid from the inflatable volume of the air bag14b. In this embodiment, the adaptive tether250, in addition to the shaping functions, also comprises a vent tether258that is operative to actuate the vent260in response to vehicle and occupant conditions at the time the air bag14bis deployed. The vent260thus may selectively release inflation fluid from the air bag14bdepending on these conditions.

The vent260may have various configurations. In the embodiment illustrated inFIGS. 10-12, the vent260has the configuration illustrated inFIGS. 13 and 14.FIG. 13illustrates the vent260in an open condition.FIG. 14illustrates the vent260in a closed condition. The vent260includes one or more vent openings262formed in a panel264, such as a side panel, of the air bag14b. A vent door266is secured to the side panel264and covers the openings262. The vent tether258has a first end portion secured to the vent door266, and extends through a guide268that is secured to the air bag panel264.

The vent door266is secured to the panel264by known means, such as stitching, ultrasonic welding, heat bonding, or adhesives. In the illustrated embodiment, the vent door266itself includes separate panels270of material that are secured to each other by known means, such as stitching, to give the vent door the illustrated configuration. Those skilled in the art will appreciate that the vent door266could have alternative single panel or multiple panel constructions.

The vent door266has one or more vent openings272formed therein. In the embodiment illustrated inFIGS. 13 and 14, the vent door266includes two vent openings272. The vent tether258is secured to a strip274of material of the vent door266that is positioned between the vent openings272. The strip274interconnects opposing cover flaps276of the vent door266. The vent260has an open condition (FIG. 13) in which the vent tether258is relaxed or slacked, thereby permitting the cover flap portions276of the vent door266to bulge outwardly and assume a convex configuration. In this condition, the vent openings272are opened and thereby release inflation fluid (indicated by arrows) from the air bag14bthrough the openings262and272.

The vent260has a closed condition (FIG. 14) in which the vent tether258is tensioned and forced by the guide268to extend along the air bag panel264. In this condition, the cover flap portions276of the vent door266are tensioned along the air bag panel264. The shape and size of the cover flap portions276are configured such that, when tensioned along the air bag panel264, they both close the vent openings272of the vent door266and cover the opening262in the air bag panel264. In the closed condition of the vent260, the vent door266thus blocks inflation fluid from exiting the air bag14b.

The air bag14b, vent260, and adaptive tether250are constructed and arranged to adapt to vehicle and occupant conditions in the vehicle12bat the time the air bag is deployed. The anchor tether252, shaping tether254, trigger tether256, vent tether258, and actuatable fastener122bof the embodiment ofFIGS. 10-14, in a manner similar to the embodiments ofFIGS. 2-9, are operative to shape or restrict deployment of the air bag14bin the event of a forward positioned occupant and permits full deployment of the air bag in the event of a rearward positioned occupant. The shaping function is achieved via the combination of the anchor tether252, shaping tether254, and trigger tether256in the manner described in regard to the embodiments ofFIGS. 2-9, i.e., the air bag14bis restricted or shaped if the trigger tether is released, and the air bag is released for full deployment if the trigger tether connection is maintained. Through the configuration of the adaptive tether250and vent260of the embodiment ofFIGS. 10-14, however, the apparatus10bis configured to provide three different responses to sensed occupant conditions.

As shown inFIGS. 10B,11B, and12B, the vent tether258and trigger tether256are connected to the housing34bof the air bag module30bvia an actuatable fastener122b. The anchor tether252is connected to the housing34bvia a fastener280, such as a bolt, rivet, or stud. The anchor tether252could be connected to alternative structure, such as the mouth of the air bag14bor to the instrument panel36b.

The vent tether258is constructed and arranged to adapt to selectively actuate the vent260in response to vehicle and occupant conditions in the vehicle12bat the time the air bag14bis deployed. Since the vent tether258is connected to the vent door266and to the actuatable fastener122b, the vent tether can be adapted to respond to whether or not the actuatable fastener is actuated. If the actuatable fastener122bis actuated, the vent tether258is released and the vent260is thereby released to the open condition ofFIG. 13. If the actuatable fastener122bis not actuated, the vent tether258is tensioned and the vent260is maintained in the closed condition ofFIG. 14.

Whether the shaping tether256shapes the air bag14bdepends on whether the actuatable fastener122breleases the trigger tether256from its connection with the housing34b. If the actuatable fastener122bis actuated, the trigger tether256is released and the connection between the anchor tether252and the shaping tether254is maintained, thereby shaping the air bag14band restricting its deployment. If the actuatable fastener122bis not actuated, the connection of the trigger tether256to the housing34bis maintained and the trigger tether tears the stitching connecting the anchor and shaping tethers252and254, thus releasing the air bag14bfor full deployment.

Actuation of the actuatable fastener122bdepends on sensed vehicle and/or occupant conditions in the vehicle. When an event occurs which inflation of the air bag14bis desired, the adaptive tether250respond to vehicle conditions, occupant conditions, or both to help control inflation and deployment of the air bag. According to the embodiment ofFIGS. 10-14, this control is implemented actively based on sensed conditions in the vehicle12b. To achieve this function, the apparatus10bincludes a sensor50b, connected to the inflator32bvia lead wires52b, that actuates the inflator upon sensing the occurrence of an event for which inflation of the air bag14bis desired. The apparatus10balso includes a controller, illustrated schematically at140b, for actuating the actuatable fastener122b. The controller140bis operatively connected to the actuatable fastener122bvia lead wires142b. Upon the occurrence of an event for which inflation of the air bag14bis desired, such as a collision, the controller140bdetermines whether to actuate the actuatable fastener based on vehicle conditions, occupant conditions or both vehicle and occupant conditions at the time of the sensed event.

The controller140bis also operatively connected to sensors that provide signals that the controller can use to infer or determine the vehicle/occupant conditions. For example, as shown inFIGS. 10-12, the apparatus10bmay include one or more sensors144bthat can provide a signal to the controller140bvia lead wires142bthat is indicative of a sensed seat position, a sensed weight on the vehicle seat22b, a sensed presence of an occupant20bon the vehicle seat, or a combination of these conditions. Through the controller140band sensors144b, the apparatus10bmay, for example, be adapted to respond to the size or position of the vehicle occupant20b.

According to the embodiment ofFIGS. 10-14, actuation of the actuatable fastener122b, and the resulting conditions, are determined according to the process300illustrated in the block diagram ofFIG. 15. Referring toFIG. 15, at block302, an event occurs, which triggers actuation of the inflator32band a determination of vehicle and/or occupant conditions via the sensors144band controller140b. At block304, a determination is made as to the presence of a large unbelted occupant22bin the vehicle seat20b. This determination, made at least in part via the sensor(s)144b, may include a seat position determination, a seat weight determination, an occupant presence determination, a seatbelt latched determination, or a combination of these determinations.

If, through the determinations at block304, a large unbelted occupant in a mid/rearward seating position is determined, the process300proceeds to block306, and the actuatable fastener122bis not actuated. As a result, the trigger tether256releases the connection between the anchor tether252and the shaping tether254. Also, the vent tether258pulls the vent260to the closed condition. As a result, the air bag14binflates to the fully deployed and pressurized (non-vented) condition ofFIGS. 10A-B, as indicated at block308.

If, through the determinations at block304, a large unbelted occupant in a mid/rearward seating position is not determined, the process300proceeds to block310. At block310, a determination is made as to the presence of a large belted occupant22bin the vehicle seat20b. This determination, made at least in part via the sensor(s)144b, may include a seat position determination, a seat weight determination, an occupant presence determination, a seatbelt latched determination, or a combination of these determinations.

If, through the determinations at block310, a large belted occupant in a mid/rearward seating position is determined, the process300proceeds to block312. As indicated at block312, the actuatable fastener122bis actuated after the trigger tether256releases the connection between the anchor tether252and the shaping tether254. This may be done, for example, by delaying actuation of the fastener122bfor a predetermined amount of time sufficient to ensure that the connection between the shaping tether254and anchor tether252is released. Actuation of the actuatable fastener122balso releases the vent tether258so that the vent260is released to the opened condition. As a result, the air bag14binflates to the fully deployed with vented pressurization condition ofFIGS. 11A-B, as indicated at block314.

If, through the determinations at block310, a small belted or unbelted occupant in a forward seating position is not determined, the process300proceeds to block316. At block316, a determination is made as to the presence of a small belted or unbelted occupant22bin a forward seating position in the vehicle seat20b. This determination, made at least in part via the sensor(s)144b, may include a seat position determination, a seat weight determination, an occupant presence determination, a seatbelt latched determination, or a combination of these determinations.

If, through the determinations at block316, a small belted or unbelted occupant in a forward seating position is determined, the process300proceeds to block318. As indicated at block318, the actuatable fastener122bis actuated before the trigger tether256releases the connection between the anchor tether252and the shaping tether254. This may be done, for example, by actuating the fastener122bimmediately without a time delay to ensure that the connection between the shaping tether254and anchor tether252is maintained. Actuation of the actuatable fastener122balso releases the vent tether258so that the vent260is released to the opened condition. As a result, the air bag14binflates to the reduced size and volume with vented pressurization condition ofFIGS. 12A-B, as indicated at block320.

Advantageously, in view of the above, those skilled in the art will appreciate that the apparatus10bof the embodiment ofFIGS. 10-15provides an apparatus10bin which the air bag14bis deployable to one of three different deployed conditions using a single actively actuatable device, i.e., the actuatable fastener122b. Due to the novel structure and performance of the adaptive tethers disclosed herein, the air bag14bcan be placed in one of the fully deployed non-vented condition, the fully deployed vented condition, and the reduced volume vented condition using the actuatable fastener122bas the single actively actuatable device for selecting the desired one of these three conditions. Those skilled in the art will appreciate the advantages in terms of cost, simplicity, reliability realized by providing three selectable configurations using a single actuatable device having two discrete (i.e., non-actuated and actuated) conditions.

From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, the adaptive tether configurations disclosed herein could be altered in order to adjust the shaping of the associated air bag. For example, the location on the air bag (e.g., the front panel) where the shaping tether is connected may be selected to alter or adjust the resulting shape of the bag. Examples of this are illustrated inFIGS. 2,6, and12A, where an alternative configuration of the adaptive tether and the resulting shape of the air bag is illustrated in dashed lines at350. In this example, deployment of a lower portion of the air bag is restricted as shown. It will thus be appreciated that, depending on the chosen location and configuration of the shaping tether(s), deployment of portions of the air bag adjacent one or more of the head, chest, thorax, and abdomen can be restricted. The location of the adaptive tethers and the resulting shaping is not limited to those illustrated in the figures and may be adjusted to any location to achieve a desired shaping at that location to restrict deployment of the air bag adjacent one or more of the head, chest, thorax, and abdomen of the occupant.

Additionally, more than one adaptive tether may be implemented in the air bag configurations of any of the embodiments disclosed herein. For example, the adaptive tethers illustrated in dashed lines at350inFIGS. 2,6, and12A may be included in addition to the respective adaptive tethers illustrated in those figures. The number of adaptive tethers implemented in any of the disclosed air bag configurations and the resulting shaping is not limited to those illustrated in the figures. The number of adaptive tethers included in any of the disclosed embodiments may be adjusted to achieve the desired shaping of the air bag.

Furthermore, although the embodiments disclosed herein are illustrated in implementations on a passenger side of the vehicle, those skilled in the art will appreciate that the present invention is intended for and may be implemented on either the driver side of the vehicle or the passenger side of the vehicle. In a driver side implementation, the apparatus would simply be mounted to the vehicle steering wheel instead of being mounted to the instrument panel. While, in this instance, the overall shape of a steering wheel mounted air bag may differ from that of the instrument panel mounted air bag, the basic function of the adaptive tether and vent would be virtually identical.

The above and other such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.