US20120280477A1

US20120280477A1 - Safety venting with passively closeabvle vents

Info

Publication number: US20120280477A1
Application number: US13/553,521
Authority: US
Inventors: Larry D. Young; Jeffrey D. Williams; John C. Newkirk
Original assignee: Autoliv ASP Inc
Current assignee: Autoliv ASP Inc
Priority date: 2009-08-05
Filing date: 2012-07-19
Publication date: 2012-11-08
Also published as: US20110031725A1; US8226118B2

Abstract

The airbag cushion has a passive venting system that remains open or transitions to a closed position depending on the impact of the airbag with an occupant and the position of the occupant. The venting system self closes upon deployment when an occupant is not out of position but remains open when an occupant is out of position. The venting system self closes due to cushion membrane tension.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of now pending U.S. patent application Ser. No. 12/536,360, filed Aug. 5, 2009, entitled “Safety Venting with Passively Closeable Vents,” the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to the field of automotive protective systems. More specifically, the present invention relates to inflatable airbags for automobiles.

BRIEF DESCRIPTION OF THE DRAWINGS

Understanding that drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1A is a side view of the inside of an airbag cushion that has fully expanded following deployment of the unobstructed airbag. The vent opening is covered by the vent cover.

FIG. 1B is a side view of the outside of the airbag cushion shown in FIG. 1A showing the vent opening and the vent cover in shown in phantom since it is attached on the inside to the cushion membrane.

FIG. 2A is an enlarged perspective view of a portion of the inside of an airbag cushion with a vent cover distended away from a vent opening.

FIG. 2B is an enlarged perspective view of the embodiment shown in FIG. 2A following deployment of the unobstructed airbag with a vent opening covered by a vent cover.

FIGS. 3A-3C provides cross-sectional, perspective views that depict an airbag incorporating the embodiment of FIGS. 2A-2C during unobstructed deployment of an airbag cushion without an out-of-position occupant adjacent thereto.

FIG. 4A is a partial cut-away of an airbag cushion that depicts the airbag cushion deployed with an out-of-position occupant adjacent thereto and provides a perspective view of the interior of the airbag cushion. This embodiment has a cord that extends through a cord attachment and connects two opposing vents. The cord extends through a hole in the vent cover of each vent. The cord has ends that are each coupled to a side panel of each vent.

FIG. 4B is a partial cut-away of the embodiment of the airbag cushion shown in FIG. 4A that provides a perspective view of the interior of the airbag cushion. FIG. 4B depicts the airbag cushion deployed with an occupant that is not out-of-position.

FIG. 5A is a partial cut-away of an airbag cushion that depicts the airbag cushion deployed with an out-of-position occupant adjacent thereto and provides a perspective view of the interior of the airbag cushion. This embodiment has a cord that extends through a cord attachment so that the cord can move laterally within the cord attachment. The cord connects two opposing vents. The cord extends through a hole in the vent cover of each vent. One end of the cord is attached to a side panel of the first vent while the other end is positioned beyond a side panel of the second vent and terminates at a stop.

FIG. 5B depicts the embodiment shown in FIG. 5A with the airbag cushion deployed with an occupant that is not out-of-position. FIG. 5B is a partial cut-away of the airbag cushion that provides a perspective view of the interior of the airbag cushion.

FIG. 6A is a partial cut-away of an airbag cushion that depicts the airbag cushion deployed with an out-of-position occupant adjacent thereto and provides a perspective view of the interior of the airbag cushion. This embodiment has two cords that extend through two respective holes in the cushion membrane such that a segment of each cord extends out of the cushion membrane and are coupled at the other ends to the vent covers of each vent and is attached at its opposing ends to a side panel of each vent.

FIG. 6B depicts the embodiment shown in FIG. 6A with the airbag cushion deployed with an occupant that is not out-of-position. FIG. 6B is a partial cut-away of the airbag cushion that provides a perspective view of the interior of the airbag cushion.

FIG. 7A is a partial cut-away of an airbag cushion that depicts the airbag cushion deployed with an out-of-position occupant adjacent thereto and provides a perspective view of the interior of the airbag cushion. This embodiment has a cord that is coupled to (more specifically, attached to) a vent cover of a first vent and is coupled to ((more specifically, extends through holes in) a vent cover of a second vent. The cord also extends through a hole in the cushion membrane such that a segment of the cord extends out of the cushion membrane.

FIG. 7B depicts the embodiment shown in FIG. 7A with the airbag cushion deployed with an occupant that is not out-of-position. FIG. 7B is a partial cut-away of the airbag cushion that provides a perspective view of the interior of the airbag cushion.

FIG. 7C is an enlarged side view of a vent in the open position that is very similar to the vent shown in FIG. 7A.

FIG. 7D is an enlarged side view of a vent in the closed position that is very similar to the vent shown in FIG. 7B.

FIG. 8A is a top plan view of the airbag cushion with a fold or depression at the location where the cord extends out of a hole in the cushion membrane.

FIG. 8B is a side view of the fold shown in FIG. 8A.

FIG. 8C is a side view of the airbag module shown in FIGS. 8A-8B with the folded half of the airbag cushion after it has been rolled.

FIG. 8D is a top plan view of the airbag cushion after the transition from the step shown in FIG. 8B with the rolled portion shown in FIG. 8C.

FIG. 8E is a top plan view of the airbag cushion shown in FIGS. 8A-8D after the right side of the airbag cushion has been folded.

FIG. 8F is a top plan view of the airbag cushion shown in FIGS. 8A-8E after the right side of the airbag cushion has been folded again.

FIG. 8G is a top plan view of the airbag cushion shown in FIGS. 8A-8F after the left side of the airbag cushion has been folded like the right side in FIG. 8E.

FIG. 8H is a top plan view of the airbag cushion shown in FIGS. 8A-8G after the left side of the airbag cushion has been folded again to be symmetrical with the right side.

FIG. 8I is a top plan view of the airbag cushion shown in FIGS. 8A-8H after the folded portions on the right and left sides have been further folded.

FIG. 8J is a top plan view of the airbag cushion shown in FIGS. 8A-8I after the overhanging portion is folded to fit into a housing with the inflator.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention described hereinafter relates to inflatable airbags and more specifically to a venting system used to vary the deployment force when there is an out of position (“OOP”) occupant in a vehicle. Each venting system described hereinafter comprises a cushion vent. The cushion vent comprises a vent opening formed in an airbag and a vent cover that covers the vent opening. The vent is configured such that the occupant's position adjacent to the airbag cushion body at the time of deployment allows the vent to self select its position to either remain open or transition to a closed position. At breakout, the vent is initially open so that inflation gas can be vented. If an OOP occupant is encountered then the impact against the occupant prevents the airbag from fully expanding and the vent remains open. If deployment of the airbag is unobstructed by an OOP occupant then the body of the airbag expands sufficiently to have a certain membrane force that causes the vent cover to tautly cover the vent opening. This configuration permits the vent to be self sealing for dynamic in-position load situations. In addition to the mechanism of fabric tension as driven by bag pressure, other factors that contribute to the ability of the vent to close include the geometry and orientation of the vent cover. Some embodiments have a tether that assists with maintaining the vent cover in a desired position while other embodiments are not tethered.
With reference now to the accompanying figures, FIGS. 1A-1B depict an airbag cushion 101 that has been fully inflated. FIG. 1A shows the interior surface 105 i of membrane 105 of airbag cushion 101. FIG. 1B shows the exterior surface 105 e of cushion membrane 105. In the embodiment depicted in FIGS. 1A-1B, cushion vent 120 is initially open and passively self closes.
Cushion vent 120 has a cushion vent opening 130 that is cut or otherwise formed in membrane 105 of airbag cushion 101. Although cushion vent opening 130 is shown in the accompanying figures as a slit, the cushion vent opening may have other shapes and may have varying lengths. Virtually any shape of vent, and any shape of associated vent cover—including round, triangular, polygonal, etc.—may be suitable. In the depicted embodiment, cushion vent opening 130 is a slit. A vent cover 140 is attached to the airbag cushion body 110 in the vicinity of cushion vent opening 130, as depicted in FIGS. 1A-1B. It should be appreciated that, whereas the vent cover 130, in these figures, is attached to the interior surface 105 i of cushion membrane 105, it may be attached to the exterior surface 105 e of airbag cushion membrane 105 in other embodiments.
In an embodiment featuring a rectangular-shaped vent cover as depicted in FIGS. 1A-2B, three sides of vent cover 140—marked as sides 142, 144, and 146 in FIGS. 2A-2B—may be sewn or otherwise attached to the airbag cushion. The fourth side, shown at 148, remains unattached so as to allow that side to be gathered or otherwise held away from the cushion vent opening 130. Of course, many variations are possible. For instance, a portion or portions of side 148 may be attached to the airbag cushion on either side of the cushion vent so as to leave only a portion of side 148 unattached, the side opposite from side 148, side 144, may remain unattached, or the vent cover may be attached at intervals as opposed to along an entire vent cover side. As long as the essential functional features of the invention are present, any number of alternative structures may be used.
As shown in FIGS. 1A-1B, vent opening 130 may have a slit-shape with a curvature that is concavely bowed downward toward side 144. The stitches used to attach the sides of vent cover 140, identified in FIGS. 1A-2B as stitches 143, 145, 147 and 149, may also have varying configurations. Stitches 143 and 147 are generally straight and parallel with respect to each other. Stitches 145 have a curvature that is convexly bowed upward toward side 148 but may also be straight in other embodiments. The curvature of stitches 145 assists with closing the vent by orienting vent cover 140 into a closed position. In the depicted embodiment, stitches 149 are not used to attach side 148 as they do not pass through membrane 105 along the length of side 148. Stitches 149 increase the edge stiffness and weight so that it is easier to seal the fabric of cover 140 over opening 130. Stitches 149 have a curvature that is concavely bowed downward toward side 144 but may also be straight. Note that stitches 149 extend beyond cover 140 into membrane 105. The concave configuration of stitches 149 and stitching beyond cover 140 assist in keeping cover 140 initially bowed out so that gas can escape through vent 120.
As indicated above, cover 140 is shown attached to an interior surface 105 i of membrane 105 but the cover could also be attached to exterior surface 105 e. Also, the vent opening and the vent cover can be anywhere on the opposing side panels of the airbag with any suitable orientation or at other locations such as the top or bottom of the airbag cushion.
FIGS. 3A-3C depict the inflation or deployment of an airbag module incorporating an embodiment that is similar to the embodiment depicted in FIGS. 1A-2B. The orientation of the vent cover and the vent opening with respect to the flow of gas in the airbag body is a design variable as shown by these embodiments. In the embodiment shown in FIGS. 1A-1B, vent opening 130 and vent cover 140 are oriented generally downstream of the gas flow just beyond throat portion 104 at an angle that is less than 90° with respect to the flow of gas out of throat portion 104. More particularly, the orientation of vent opening 130 and vent cover 140 in the embodiment depicted in FIGS. 1A-1B is in a range of about 30° to about 60° such as about 45°. The embodiment depicted in FIGS. 3A-3C, in contrast, has vent opening 130 and vent cover 140 oriented at about 90° with respect to the flow of gas out of throat portion 104 or with respect to the windshield.
Airbag module 100 depicted in FIGS. 3A-3C is positioned in the car's dashboard 20 and deploys against the dashboard 20 and the windshield 10. The sequence shown in FIGS. 3A-3C is intended to depict deployment of an unobstructed airbag. In other words, the occupant is either in his or her proper position in the vehicle away from the airbag deployment location or there is no occupant in the seat adjacent to the airbag system at all. The airbag module depicted at 100 comprises an airbag cushion 101 and an inflator 102. Airbag cushion 101 has body 110, cushion vent 120, which includes vent opening 130 and vent cover 140, and a secondary vent 170.
The vent openings and vent covers can be designed to optimize the amount of inflation gas that is vented. For example, a large vent opening provides for rapid dumping of a large volume of gas compared with a smaller vent opening. It is contemplated that systems constructed in accordance with the principles of the present invention can include any number of cushion vents. A single cushion vent, two cushion vents—on opposing sides of the airbag body, for instance—or any other number of cushion vents may be used as desired. The cushion vent(s) may be positioned at any suitable location on the airbag body such as the top or bottom of the airbag body. Also, the cushion vent(s) could be positioned in the throat portion, such as a constricted throat portion like throat portion 104 in the accompany figures. The vents disclosed herein can also function with a loop diffuser to more rapidly direct inflation gas to the cushion vents.
The systems shown in the accompanying drawings also comprise one or more smaller or standard cushion openings, referred to herein as secondary vent openings 170, which typically do not include a vent cover and are therefore always open. Such secondary vent openings are, of course, optional, and typically have a smaller cross-sectional area than the cushion vent openings that are adapted to be covered with a vent cover in accordance with the principles of the invention.
Prior to deployment, the system may be housed in the vehicle's dashboard, instrument panel, steering wheel, or other such location. In the depicted embodiment, the system is housed in the dashboard 20 and as such is positioned partially against the car's windshield 30 when deployed.
FIG. 3A depicts the airbag system in the immediate milliseconds following deployment. The inflation gas or other fluid (represented by the arrows inside the bag) is causing the airbag body 110 to expand in the direction of the arrows just outside of the airbag on the figure. It should be noted that, at this early stage during deployment, the system can be configured such that inflation gas loss through the one or more cushion vents is minimal. In such embodiments, the cushion vent(s) may be positioned laterally with respect to the inflation gas flow as opposed to directly in the stream of the gas flow. When the cushion vent(s) are so positioned, the high velocity stream of gas creates a pressure imbalance (Bernoulli effect) which tends to prevent substantial amounts of inflation gas from exiting the airbag. Note that the embodiment depicted in FIGS. 3A-3C has an optional fixed vent 170.
At the point in time depicted in FIG. 3B, airbag body 110 has expanded sufficiently to allow the tension in the material of the airbag body, more particularly, the tension of the cushion membrane (represented by the arrows next to vent cover 140) has significantly increased, thereby allowing vent cover 140 to be tautly pressed against vent opening 130. Vent cover 140 in FIG. 3B is therefore in the process of covering vent opening 130 to prevent or at least impede the escape of inflation gas therethrough.
In FIG. 3C, vent cover 140 has covered vent opening 130 and airbag body 110 is shown fully inflated. Also, vent opening 130 has been pulled to a closed position. In this manner, the inflation gas is impeded from exiting airbag body 110.
The embodiments of the vent covers shown in FIGS. 1A-1B, FIGS. 2A-2B, and FIGS. 3A-3C are initially distended away from the vent opening and move without interaction with other structures that provides initial restraint that is overcome by the cushion membrane tension. This configuration enhances the ability to quickly responding so that they can easily self close. These embodiments also freely move without a track that guides movement for alignment and non-alignment of holes.
Other embodiments of airbag modules are shown at 200, 300, 400 and 500 respectively in FIGS. 4A-4B, FIGS. 5A-5B, FIGS. 6A-6B and FIGS. 7A-7D. FIGS. 4A, 5A, 6A, 7A and 7C depict deployment of the airbag module with an adjacent out-of-position occupant who is positioned too close to the airbag cushion at the time of deployment. FIGS. 4B, 5B, 6B, 7B and 7D depict deployment of the respective airbag modules when the adjacent occupant is either missing or in his or her proper position in the car seat. Note that identical or similar elements have the same numeral as increased in a series by one hundred. Note also that components featured as part of one embodiment can be combined with components of another embodiment. For example, the configuration of the vent covers and vent openings in the embodiments shown in FIGS. 1A-1B, FIGS. 2A-2B, and FIGS. 3A-3C can replace the vent covers and vent openings shown in FIGS. 4A-4B, FIGS. 5A-5B, FIGS. 6A-6B and FIGS. 7A-7D.
The embodiment of the airbag module, shown in FIGS. 4A-4B at 200, comprises an airbag cushion 201 and an inflator 202. Opposing vents 220 are positioned at the opposing sides of airbag cushion 201. Each vent 220 comprises a vent opening 230, a vent cover 240 and a side panel 250. A cord 260 is coupled to each side panel 250 at one end. More specifically, the end of cord 260 is attached via stitches 254; however, other suitable coupling components may be utilized to couple the end of the cord to side panel. The other end of each cord 260 is attached to cord attachment 262, which is positioned to move with membrane 205 at the front of airbag cushion 201, namely the front panel. Each cord 260 is moveably positioned in the hole 241 of each vent cover 240. Movement of cord attachment 262 pulls each cord through the respective holes 241 of vent covers 240.
Each paired vent cover 240 and side panel 250 are on opposite sides of the cushion membrane 201. Also, each vent cover and side panel has a side that is at least partially unattached to the cushion membrane, referred to as the unattached side. The respective unattached sides of a paired vent cover 240 and side panel 250 are overlapping so that when they are pulled together they seal vent opening 230 closed.
The airbag cushion 201 is shown in FIG. 4A in approximately the same stage of inflation as in FIG. 3A. However, in FIG. 4A an occupant is out of position in the adjacent seat. Due to the presence of the out-of-position occupant, outward expansion of the airbag body 210 is impeded at the stage of inflation shown in FIG. 4A by the occupant's head, identified at 10, and airbag body 210 laterally expands. Because the airbag body 210 is not able to fully expand, cords 260 remain slack and vent covers 240 remain distended away from vent openings 230 such that vents 220 remain open. Also, side panels 250 are not pulled toward vent covers 240. Because cords 260 permit vent covers 240 to remain pulled away from side panels 250, the inflation gas is easily dumped. A substantial amount of the inflation gas therefore rapidly escapes the airbag body via the cushion vents 220. In this manner, the airbag never fully inflates and the out-of-position occupant is subjected to a smaller inflation force.
FIG. 4B shows module 200 following complete deployment of the airbag cushion with an occupant who was properly positioned adjacent to the system at the time of deployment. Cords 260 have been pulled through holes 241 of each vent cover 240 allowing the respective vent cover 240 to be self sealing with respect to the corresponding vent opening 230. Also, cords 260 have pulled side panel 250 toward the paired vent cover 240 to ensure sealing. Pulling side panel 250 toward vent cover 240 accelerates the closure of the vent because side panel 250 is pulled inward against vent cover 240. Note that cord attachment 262 is stitching that attaches cords 260 to cushion membrane 205.
In an alternative embodiment, cord 260 is replaced with a cord that lacks a stop and is not attached at its ends to the vent cover or the side panel. This embodiment features a cord that extends through a vent cover merely to distend the vent cover away from the vent opening. Once the cord is pulled through the vent cover, then the vent cover closes in the same manner as the embodiments discussed above with regard to FIGS. 1A-3C.
Holes 241 are an example of a friction interface. The friction interface ensures that vent cover 240 remains distended until the cord 260 is pulled with sufficient force to overcome the frictional resistance of the friction interface. The frictional resistance can be varied by selecting the diameter of cord 260 and the diameter of the rim of holes 241. Also, the shape of the rim of holes 241 can be selected to provide a desired amount of frictional resistance. Also, the materials or coatings selected for cord 260 and the rim of holes 241 can also be selected to provide a desired amount of frictional resistance.
FIGS. 5A-5B depict an embodiment of an airbag cushion at 301 with some similarities to airbag cushion 201. Instead of two cords, airbag cushion 301 has a single cord 360. Cord 360 is positioned to maintain opposing vents 320 a-b in the open position after inflation and encountering opposition from an occupant who is out of position in the adjacent seat. Cord 360 is shown in FIG. 5A with slack between vent cover 340 a and side panel 350 a such that vent 320 a is open. There is less slack between vent cover 340 b and side panel 350 b yet it is sufficient to maintain vent 320 b in an open position. Cord 360 moves through cord attachment 362, which is a sleeve. Cord 360 is attached at end 364 a via stitches 354 a to side panel 350 a. At the other end of cord 360, stop 366 b is configured to engage a hole 352 b in side panel 350 b.
FIG. 5B shows airbag cushion 301 following its complete deployment with an occupant who was properly positioned adjacent to the system at the time of deployment. The segment of cord 360 extending beyond hole 352 b, has been pulled through hole 352 b until stop 366 b engages the rim of hole 352 b. Also, cord 360 has been pulled through holes 341 a-b of each respective vent cover 340 a-b allowing the respective vent cover 340 a-b to be self sealing with respect to the corresponding vent opening 330. The tension caused by attachment of end 364 a to side panel 350 a and engagement of stop 366 b with side panel 350 b allows cord 360 to pull each side panel 350 a-b toward the paired vent cover 340 a-b to ensure sealing.
The embodiments shown in FIGS. 4A-4B and FIGS. 5A-5B, each have a cord that extends through a hole in the vent cover and each cord has an end that engages a side panel to pull the side panel to the vent cover. In the embodiments, as depicted, the cord is coupled to the front of the airbag cushion. In these depicted embodiments, the cord is positioned to initially maintain the vent in an open position by distending the vent cover away from the vent opening and to continue maintaining the vent in the open position upon deployment of the inflatable airbag cushion with obstruction by continuing to distend the vent cover away from the vent opening. Additionally, the cord is positioned to transition the vent to a closed position upon deployment of the inflatable airbag cushion without obstruction by drawing the cord taut due to full inflation of the inflatable airbag cushion. The full inflation draws the side panel to the vent cover and permits the vent cover to move due to cushion membrane tension and cover the vent opening to block the exit of inflation gas out of the vent opening.
The embodiments shown in FIGS. 4A-4B and FIGS. 5A-5B, may also have at least one cord that is sufficiently slack that it has a segment extending between the vent cover and the side panel with a length that is greater than the distance between the side panel and the vent cover when the vent cover is distended away from the vent opening. Such a segment is referred to herein as a slack segment or a loop. There may alternatively be a slack segment between the vent cover and the cord attachment. The slack segment may also extend beyond the airbag cushion such as the segment shown in FIG. 5A that terminates at stop 366 b.
The cord attachment may be threads that fixedly attach the cord to the cushion membrane. Additionally, the cord attachment may be a socket that receives the cord. The cord attachment may also be a sleeve that permits the cord to move laterally within the sleeve and adjust to differing tension from each side of the airbag cushion. As discussed above, with reference to the embodiments depicted in FIGS. 4A-4B and FIGS. 5A-5B, the end of the cord that engages the side panel may be sewn to the side panel. Also, as discussed with respect to FIG. 5B, the end of the cord that engages the side panel may have a stop such as stop 366 b that pulls side panel 350 b.
Holes 341 a-b and cord 360 are an example of a friction interface. Hole 352 b may also be designed to provide frictional resistance to movement of cord 360. If hole 352 b provides more frictional resistance to cord 360 than occurs by designing the engagement to provide for easy sliding, it may be necessary to ensure that the combined frictional resistance of hole 341 b and hole 352 b with cord 360 equal the frictional resistance of cord 260 with hole 341 a.
FIGS. 6A-6B depict an embodiment of an airbag cushion at 401 with some similarities to airbag cushion 201. Two cords 460 a-b are respectively coupled to vent covers 440 a-b at attachments 441 a-b. More specifically, cords 460 a-b are attached to vent covers 440 a-b and attachments 441 a-b are stitches. Cords 460 a-b also each respectively extend through holes 462 a-b. Cords 460 a-b are initially pulled such that opposing vent covers 440 a-b are distended so that vents 420 a-b are in the open position. Segments of cords 460 a-b extend outside of airbag cushion 401 via holes 462 a-b. After inflation and encountering opposition from an occupant who is out of position in the adjacent seat, segments of cords 460 a-b remain outside of airbag cushion 401 as shown in FIG. 6A.
FIG. 6B shows airbag cushion 401 following its complete deployment with an occupant who was properly positioned adjacent to the system at the time of deployment. The segments of cords 460 a-b, extending respectively beyond holes 462 a-b, have been pulled into the interior of airbag cushion 401. Cords 460 a-b are not attached to side panels 450 a-b. The pressure of the inflation gas against vent covers 440 a-b pushes vent covers 440 a-b against side panels 450 a-b, thereby allowing vents 420 a-b to be self sealing.
FIGS. 7A-7B depict an embodiment of an airbag cushion at 501 with some similarities to airbag cushion 401. Cord 560 has an end attached to attachment 541 a of vent cover 540 a. Vent cover 540 b has at least one hole and in the depicted embodiment, vent cover 540 b has two holes as identified at 541 b. Cord 560 is initially pulled to be taut such that opposing vent covers 540 a-b are distended such that vents 520 a-b are in the open position. A segment of cord 560 extends outside of airbag cushion 501 via hole 562. After inflation and encountering opposition from an occupant who is out of position in the adjacent seat, the segment of cord 560 that was initially outside of airbag cushion 501 remains outside as shown in FIG. 7A and cord 560 remains sufficiently taut to maintain vents 520 a-b in an open position.
FIG. 7B shows airbag cushion 501 following its complete deployment with an occupant who was properly positioned adjacent to the system at the time of deployment. The segment of cord 560 extending beyond hole 562 has been pulled into the interior of airbag cushion 501. Cord 560 may remain in holes 541 b of vent cover 540 b. Cord 560 is not attached to side panels 550 a-b. The pressure of the inflation gas against vent covers 540 a-b pushes vent covers 540 a-b against side panels 550 a-b, thereby allowing vents 520 a-b to be self sealing.
FIGS. 7C-7D are enlarged side views of a vent 520 b′ that is very similar to vent 520 b; however, vent 520 b′ only has a single hole 541 b′. FIG. 7D shows vent 520 b′ in the closed position while FIG. 7C shows vent 520 b′ in the open position. These view shows side panel 550 b abutting vent cover 540 b. Side panel 550 b is formed by cutting a slit in cushion membrane 505 with comparatively short sides such that there is a flap of material, folding the flap of material over and then sewing the folded flap to provide reinforcement. Vent cover 540 b is attached to the interior surface 505 i of cushion membrane 505 below the slit formed in cushion membrane 505 and along the sides. While vent opening 530 b is closed, it is defined by the reinforced edge of side panel 550 b and vent cover 540 b.
The embodiments shown in FIGS. 6A-6B and FIGS. 7A-7D, each have a cord that extends through a hole in the cushion membrane at the front of the airbag cushion such that a segment of the cord that terminates at an end is positioned outside of the airbag cushion before deployment of the airbag cushion. The cord is positioned to initially maintain the vent in an open position by distending the vent cover away from the vent opening and to continue maintaining the vent in the open position upon deployment of the inflatable airbag cushion with obstruction by continuing to distend the vent cover away from the vent opening. Additionally, the cord is also positioned to transition the vent to a closed position upon deployment of the inflatable airbag cushion without obstruction due to full inflation of the inflatable airbag cushion. The full inflation pulls the cord through the hole such that the vent cover can move due to cushion membrane tension and cover the vent opening to block the exit of inflation gas out of the vent opening.
Each vent in the embodiments shown in FIGS. 6A-6B and FIGS. 7A-7D may further comprise a side panel that is adjacent to the vent opening and is positioned to cooperate with the vent cover to block the exit of inflation gas out of the vent opening. In the depicted embodiments, the cord is not coupled to the side panel; however, the cord may optionally extend from the side panel instead of the vent cover.
Holes 462 a-b can also be designed to provide a friction interface respectively with cords 460 a-b. If holes 462 a-b provides more frictional resistance to cord 460 than occurs by designing the engagement to provide for easy sliding, the frictional resistance of each cord and each hole should be about equal for symmetrical movement of the vents. Hole 562 and cord 560 may be designed such that they have more frictional resistance to movement of cord 560 than occurs between cord 560 and holes 541 b, which merely permits cord 560 to easily slide in holes 541 b. Alternatively, there may be greater frictional resistance between cord 560 and holes 541 b than with hole 562.
FIGS. 8A-8J depict a method for folding cushion 501 that results in a frictional retention of cord 560 to maintain cord 560 in the position desired to keep the vents open until inflation of the airbag cushion occurs without obstruction from an occupant. The frictional retention of cord achieved through folds and/or rolls provides a similar function to the frictional interface described above with respect to the cord and various holes, which retains the distended configuration of the vent cover to maintain the vent in the open position.
FIG. 8A shows half of airbag cushion 501 with a fold 511 at the location where cord 560 extends out of hole 562. A portion of the segment of cord 560 that extends out of hole 562 is positioned within fold 511 while a segment continues to extend beyond fold 511. FIG. 8B is the side view of the folding step shown in FIG. 8A. FIG. 8C shows the folded half of airbag cushion 501 after it has been rolled to provide rolled portion 512. The rolling contributes to retention of the vents in the open position as the rolled fold must be unrolled before cord 560 can be pulled through hole 562.
FIGS. 8D-8J show the remaining folding steps. In FIG. 8D, shows the right side 513 b of airbag cushion 501 before it is folded as shown in FIG. 8E. FIG. 8E shows right side 513 b being folded again to yield folded portion 514 b. The same steps shown in FIGS. 8D-8E are paralleled on the other side as shown in FIGS. 8F-8G, which show left side 513 a being folded to yield folded portion 514 a. Folded portions 514 a-b can then be further folded as shown in FIG. 8H at fold 515 as shown in FIG. 8I. Finally, the overhanging portion 516 is folded as shown in FIG. 8J.
After completion of the steps shown in FIGS. 8A-8J and before deployment, airbag cushion 501 comprises folds and rolls such that airbag cushion 501 has a compact configuration. Also, the segment of cord 560 extending out of the hole in the cushion membrane, as best seen in FIG. 8A, is in a rolled portion 512 of airbag cushion 501 that has also been folded, which results in a frictional retention of cord 560 to initially maintain vent 520 in an open position, and to resist transitioning the vent to the closed position until deployment of the inflatable airbag cushion without obstruction.
Many design variations are possible and should be considered within the scope of the invention. Accordingly, the design could be tailored to adjust or fine tune the deployment and deployment forces in accordance with various occupant positions. The design could be tailored, for instance, to allow a small number of cushion vents to remain open in the event that an occupant is only slightly out of position, allow a greater number of cushion vents to remain open in the event that an occupant is further out of position, and allow most or all cushion vents to remain open in the event that an occupant is positioned very close to the airbag at the time of deployment. The design could also be tailored to account for a passenger being out of position laterally with respect to the airbag by configuring the release cords to allow primarily the cushion vents on one side of the airbag cushion body or the other to remain open in accordance with the position of the out-of-position occupant. The length of cords may also differ in accordance with design specifications of the airbag cushion body.
Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.
Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. The claims that follow are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. Moreover, additional embodiments capable of derivation from each set of independent and dependent claims are also expressly incorporated into the present written description. These additional embodiments are determined by replacing the dependency of a given dependent claim with the phrase “any of the preceding claims up to and including the nearest independent claim.” For example, for the claim set that begins with independent claim 1, claim 3 can depend from either of claims 1 and 2, with these separate dependencies yielding two distinct embodiments; claim 4 can depend from any one of claim 1, 2, or 3, with these separate dependencies yielding three distinct embodiments; claim 5 can depend from any one of claim 1, 2, 3, or 4, with these separate dependencies yielding four distinct embodiments; and so on.
Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. §112 ¶6.
It will be understood by those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles presented herein. Thus, the embodiments described herein should not be used to limit the scope of the following claims.

Claims

1. An airbag module, comprising:

an inflatable airbag cushion comprising a cushion membrane which defines an interior of the inflatable airbag cushion;

at least one closeable vent comprising a vent opening in the cushion membrane and a vent cover that extends over the vent opening;

wherein the vent cover has four sides,

wherein two of the sides are opposed to each other and are attached to the cushion membrane via stitches, and

wherein the other two sides include a side that is unattached to the cushion membrane and that is opposite a side that is attached to the cushion membrane via stitches;

wherein the vent cover is initially positioned to be distended away from the vent opening such that the vent is initially open;

wherein upon deployment of the inflatable airbag cushion with obstruction, the vent cover remains positioned such that the vent is open; and

wherein upon deployment of the inflatable airbag cushion without obstruction, the inflatable airbag cushion fully inflates such that the unattached side of the vent cover moves due to cushion membrane tension until the vent cover is taut and covers the vent opening to prevent inflation gas from exiting via the vent opening.

2. The airbag module of claim 1, wherein the vent opening is slit-shaped with a curvature that is concavely bowed downward away from the unattached side of the vent cover.

3. The airbag module of claim 1, wherein the unattached side of the vent cover has stitches extending along its length with a curvature that is concavely bowed downward toward the opposite side that is attached to the cushion membrane.

4. The airbag module of claim 3, wherein the stitches that extend along the length of the unattached side of the vent cover extend beyond the vent cover into the cushion membrane.

5. The airbag module of claim 3, wherein the attached side of the vent cover that is opposite the unattached side of the vent cover has stitches with a curvature that is convexly bowed upward toward the unattached side of the vent cover.

6. The airbag module of claim 1, wherein the stitches of the two opposing sides that are attached to the cushion membrane are generally straight and parallel with respect to each other.

7. The airbag module of claim 1, wherein the airbag cushion has a throat portion which receives inflation gas from an inflator, wherein the vent opening and vent cover are oriented downstream of the gas flow out of the throat portion at an angle that is about 90° with respect to the flow of gas out of the throat portion.

8. The airbag module of claim 1, wherein the airbag cushion has a throat portion which receives inflation gas from an inflator, wherein the vent opening and vent cover are oriented downstream of the gas flow out of the throat portion at an angle that is less than 90° with respect to the flow of gas out of the throat portion.