INFLATABLE KNEE AIRBAG ASSEMBLIES WITH BAG STRAPS FOR WRAPPING THE AIRBAGS AND OPTIMIZING DEPLOYMENT

• US 20100270782A1
• Filed: 04/27/2009
• Published: 10/28/2010
• Est. Priority Date: 04/27/2009
• Status: Abandoned Application

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Lunt, Larry, Enders, Mark L., Mueller, Louis
• Application Number:
  US12/430,246
• Publication Number:
  US 20100270782A1
• Time in Patent Office: Days
• US Class Current: 280/743.200
• CPC Class Codes: B60R 2021/23169 specially adapted for knee protection
• CPC Class Codes: B60R 2021/23382 Internal tether means
• CPC Class Codes: B60R 21/201 Packaging straps or envelopes for inflatable members
• CPC Class Codes: B60R 21/231 characterised by their shape, construction or spatial configuration
• CPC Class Codes: B60R 21/2338 Tethers
• CPC Class Codes: B60R 21/237 characterised by the way they are folded

Abstract

An airbag assembly with a reduced-cost knee airbag cushion and internal tethers can be formed from a single rectangular panel of material so that there is very little material waste. A pleat can be formed in a rear face so that the combination of tethers and pleat help the cushion deploy with favorable characteristics and adopt an arced shape when inflated. The cushion can have apertures for inserting an inflator with mounting stems partially within the cushion so that the mounting stems can be used to couple the cushion to an airbag housing. The assembly can also have a bag strap formed from a single piece of fabric that can wrap around a rolled and/or folded cushion. The assembly can also have a stabilizer strap that can be coupled to the cushion and to the airbag housing so that during deployment, the cushion does not skew or twist.

Claims

1. An inflatable airbag cushion assembly, comprising:

an airbag housing;

an inflator coupled to the housing;

a packaged inflatable airbag cushion located within the airbag housing and in fluid communication with the inflator; and

,

a bag strap coupled to the airbag cushion, wherein the bag strap comprises perforations that are located at a predetermined location, such that the perforations control a predominate direction of airbag cushion trajectory during deployment,

wherein upon activation of the inflator, the bag strap temporarily restricts a horizontal trajectory of the airbag cushion as the cushion becomes inflated and exits the housing such that the predominate direction of airbag cushion trajectory can be said to be vertical, relative to the housing.

2. The inflatable airbag cushion assembly of claim 1, wherein the bag strap comprises a first length and a second length, wherein the second length is shorter than the first length, and wherein in a pre-deployment configuration, the bag strap comprises the second length and during deployment, the bag strap adopts the first length.

3. The inflatable airbag cushion assembly of claim 2, wherein the first length comprises a deployment length and the second length comprises a wrapping length.

4. The inflatable airbag cushion assembly of claim 1, wherein during deployment, the bag strap is configured to rupture such that the bag strap comprises at least two pieces of material.

5. The inflatable airbag cushion assembly of claim 4, wherein a point at which the bag strap ruptures controls a predominate direction of the cushion'"'"'s trajectory.

6. The inflatable airbag cushion assembly of claim 3, wherein after the bag strap changes lengths from the second length to the first length, tucked sides of the inflatable airbag cushion expand outward in opposite directions, wherein each of the directions are substantially perpendicular to the predominate direction of airbag cushion trajectory.

7. An inflatable airbag cushion assembly, comprising:

an inflatable airbag cushion, having an upper portion and a lower portion as well as a first face and a second face, wherein the lower portion comprises an attachment portion for coupling the airbag cushion to an inflator and a housing, and wherein the first and second faces define an inflatable void; and

,

a bag strap coupled to the inflatable airbag cushion, wherein the bag strap comprises a piece of material having a plurality of apertures and a plurality of perforations, the piece of material also having a first end and a second end, wherein the first end can be attached to the second face of the airbag cushion at the lower portion of the cushion, and the second end is configured to be coupled to an airbag housing and an airbag inflator such that a middle portion of the bag strap wraps around the airbag cushion after the cushion has been placed in a folded configuration,

wherein the bag strap comprises a loop of bag strap material that shortens the length of the bag strap, and wherein the bag strap is configured such that prior to airbag deployment the loop is retained in the bag strap and during airbag deployment, the loop ceases to be retained, such that during deployment the bag strap may adopt a longer configuration, and

wherein the bag strap is configured such during airbag deployment, that the perforations rupture after the bag strap has adopted the longer configuration.

8. The inflatable airbag cushion assembly of claim 7, wherein the bag strap loop comprises tear stitching that is configured to retain the bag strap loop prior to airbag deployment, and wherein the tear stitching is configured to rupture during airbag deployment.

9. The airbag assembly of claim 7, wherein the first end of the bag strap comprises at least one fold of the bag strap.

10. The airbag assembly of claim 7, wherein the second end comprises at least one fold of the bag strap.

11. The airbag assembly of claim 7, wherein the bag strap is configured such that the perforations run approximately parallel with a fold in the airbag cushion that is located at the bottom portion of the airbag cushion.

12. The airbag assembly of claim 7, wherein the first end of the bag strap comprises at least one aperture for receiving a portion of an inflator.

13. The airbag assembly of claim 11, wherein the at least one aperture comprises an inflator insert aperture and an inflator mounting stem aperture.

14. The airbag assembly of claim 7, wherein the second end comprises at least one inflator stem aperture that is configured to receive an inflator mounting stem after the bag strap has been wrapped around the airbag cushion, thereby retaining the airbag cushion in a folded state, prior to airbag deployment.

15. The airbag assembly of claim 7, wherein the bag strap is configured such that after the bag strap has been wrapped around the airbag cushion, the perforations are located at a predetermined position that defines a predetermined predominate direction of cushion travel during deployment.

16. The airbag assembly of claim 7, wherein the bag strap comprises a piece of woven nylon fabric.

17. An inflatable airbag cushion assembly, comprising:

an airbag housing comprising a plurality of apertures;

an inflator coupled to the housing, wherein the inflator comprises a first mounting stem and a second mounting stem, each of which extend perpendicularly from a body portion of the inflator;

a folded inflatable airbag cushion located within, and coupled to, the airbag housing, wherein the airbag cushion has been folded in a predetermined manner such that the cushion may deploy with predetermined deployment characteristics, the airbag cushion comprising an inflator mounting stem aperture and an inflator insert aperture; and

a bag strap comprising a body portion with a first end and a second end, wherein the first end comprises an inflator aperture and an inflator stem aperture, and wherein the first end of the bag strap is attached to the folded inflatable airbag cushion such that the inflator aperture of the bag strap coincides with the inflator insert aperture of the airbag cushion and the inflator stem aperture of the bag strap coincides with the inflator mounting stem aperture of the airbag cushion, and wherein the second end comprises two stem apertures,

wherein a portion of the inflator body and the second inflator mounting stem protrudes through the inflator insert aperture of the airbag cushion and the coinciding inflator insert aperture of the bag strap, and wherein the first inflator mounting stem protrudes through the inflator mounting stem aperture in the airbag cushion and the coinciding inflator stem aperture of the bag strap, and

wherein the bag strap body portion is wrapped around the folded airbag cushion and the each of the two inflator stem apertures located on the bag strap second end receive one of the inflator mounting stems such that the first end of the bag strap and the second end of the bag strap are located adjacent each other.

18. The airbag assembly of claim 17, wherein the body portion of the bag strap comprises a looped portion that is retained as a loop via tear stitching.

19. The airbag assembly of claim 18, wherein the bag strap comprises perforations.