Tethers with tearseams for air bag cushion

• US 5,489,119 A
• Filed: 04/21/1995
• Issued: 02/06/1996
• Est. Priority Date: 09/01/1992
• Status: Expired due to Term

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Prescaro, Kay H., Ward, Michael J., Kriska, Thomas M.
• Primary Examiner(s): Culbreth, Eric D.
• Application Number:
  US08/427,632
• Time in Patent Office: 291 Days
• Field of Search: 280/743.2, 280/743.1, 280/728.1, 280/730.1, 280/728.3
• US Class Current: 280/743.2
• CPC Class Codes: B60R 2021/23382 Internal tether means
• CPC Class Codes: B60R 21/233 comprising a plurality of individual compartments; comprising two or more bag-like members, one within the other B60R21/232 takes precedence
• CPC Class Codes: B60R 21/2338 Tethers
• CPC Class Codes: B60R 21/2342 Tear seams

Abstract

A guide device for directing the deployment of an automotive air bag cushion toward the torso of an occupant by means of a tether which is folded and attached to itself at a number of locations by rupturable seams. As the air bag cushion deploys the truncated tether or tethers cause the cushion to rotate about a point where the cushion is attached to the canister thereby moving the cushion in a downward direction. The cushion is thereby moved into position in front of the occupant'"'"'s torso more quickly than an air bag cushion equipped with a tether without tearseams.

Claims

1. In an automotive air bag assembly comprising a gas generator actuable to generate a gas under pressure, actuation means to actuate said gas generator, an air bag cushion having a first portion with a front surface and a back surface, a second portion attached to said first portion and terminating in a third portion, said third portion defining a gas inlet opening in said air bag cushion for receiving said gas from said gas generator, and at least one tether attached to said air bag cushion to restrain and direct its deployment;

the improvement comprising said at least one tether having a first end attached to the back surface of said first portion of said airbag cushion and a second end attached adjacent said third portion of said air bag cushion, each of said at least one tethers being folded upon itself to form a first tether section and a second tether section, each of said first tether sections being joined to the corresponding said second tether section at at least one contact point by releasable attachment means to thereby form a truncated tether having a releasable shortened length, a first end of said tether being attached to the back surface of said first portion of said air bag cushion and a second end of said tether being attached adjacent said third portion of said air bag cushion such that, upon actuation of said gas generator, said air bag cushion is free to deploy until said tether is extended to said releasable shortened length, said tether then restraining expansion of said air bag cushion and causing said air bag to pivot about said second end of said tether until said releasable attachment means release allowing said air bag cushion to further expand.

2. The air bag assembly of claim 1, wherein said second end of said tether is attached adjacent a side of the gas inlet opening of the air bag cushion, which side, when mounted in an automobile, will be closer to the location of the lower torso of the passenger to be protected than is the center of the gas inlet opening, whereby, during deployment, said air bag cushion will pivot toward said lower torso location when restrained by the tether at said releasable shortened length.

3. The air bag assembly of claim 1, wherein said first tether section and said second tether section are joined at at least two spaced contact points by releasable attachment means provided at each of the spaced contact points, whereby the further expansion of said air bag cushion occurring after the release of the initial releasable attachment means, is further restrained when said tether extends to place the second releasable attachment means under tension, which further restraint is removed permitting said air bag cushion to further expand upon the release of said second releasable attachment means.

4. The air bag assembly of claim 1, wherein after final deployment, the fully extended length of said tether provides for it to function to restrain further deployment of the air bag cushion.

5. The air bag assembly of claim 1, further comprising a canister, said canister having walls defining a cavity in which is located said gas generator and at least part of the folded inflatable air bag cushion, said walls further defining an opening to said cavity, said opening being in communication with said gas inlet opening in said air bag cushion, and wherein said second end of said tether is securely attached to the wall of said canister adjacent to said third portion of said air bag cushion.

6. The air bag assembly of claim 5, wherein said canister is configured to be mounted behind the dashboard of the automobile whereby, upon activation, said air bag cushion deploys in the direction of the location that a passenger in said automobile would normally occupy.

7. The air bag assembly of claim 1 wherein said releasable fastener means comprises a rupturable stitch.

8. The air bag assembly of claim 7 wherein said rupturable stitch extends transversely across said tether.

9. The air bag assembly of claim 7 wherein said rupturable stitch extends longitudinally along at least a portion of the length of said tether.

10. The air bag assembly of claim 1 wherein said releasable fastener means comprises a hook and loop fastener.

11. The air bag assembly of claim 1 wherein said tether is a fabric made from a material selected from the group consisting of nylons, polyesters, polyamides and mixtures thereof.

12. In an automotive airbag assembly comprising a gas generator actuable to generate a gas under pressure, actuation means to actuate said gas generator, an air bag cushion having a first portion with a front surface and a back surface, a second portion attached to said first portion and terminating in a third portion, said third portion defining a gas inlet opening in said air bag cushion for receiving said gas from said gas generator, and at least one tether attached to said air bag cushion to restrain and direct its deployment;

the improvement comprising said at least one tether having a first end attached to the back surface of said first portion of said air bag cushion and a second end attached adjacent said third portion of said air bag cushion, said at least one tether being folded upon itself to form a first tether section and a second tether section, each of said first tether sections being joined to the corresponding second tether section at at least one contact point by releasable attachment means to thereby form a truncated tether having a releasable shortened length, a first end of said tether being attached to the back surface of said first portion of said air bag cushion and a second end of said tether being attached to said third portion of said air bag cushion such that, upon actuation of said gas generator, said air bag cushion is free to deploy until said tether is extended to said releasable shortened length, said tether then restraining expansion of said air bag cushion and causing said air bag to pivot about said second end of said tether until said releasable attachment means release allowing said air bag cushion to further expand.

13. A vehicle air bag assembly comprising a gas generator which is actuable to produce sufficient gas to inflate an associated air bag cushion, an air bag cushion having an opening in communication with said gas generator, an actuation device operable to actuate said gas generator, at least one tether having (a) a first end attached to the inside of that portion of the air bag cushion which, when deployed, is designed to be directly in front of a vehicle occupant and (b) a second end attached adjacent the lower portion of said opening, said tether being folded and attached to itself by at least one releasable attachment means, said first and second ends of said tether also being attached at locations relative to each other such that upon actuation of said gas generator, produced gas inflates said air bag cushion causing said tether to extend to a length at which said releasable attachment means is placed under tension, and the first end of the tether with its attached air bag cushion is caused to pivot downward about the tether'"'"'s attached second end causing the direction of deployment of said airbag cushion to be lowered.

14. The air bag assembly of claim 13, wherein said first end of said at least one tether is attached at a position in the upper half of that portion of the air bag cushion which, when deployed, is designed to be directly in front of a vehicle occupant.