Packaging tether for driver side air bag cushion

• US 5,498,023 A
• Filed: 12/02/1994
• Issued: 03/12/1996
• Est. Priority Date: 12/02/1994
• Status: Expired due to Term

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Adams, Stephen L., Vine, Daniel C.
• Primary Examiner(s): FERRITER, KARIN L
• Application Number:
  US08/348,627
• Time in Patent Office: 466 Days
• Field of Search: 280/728 R, 280/743 R, 280/743 A, 280/728 A, 280/728 B, 280/743.1, 280/743.2, 280/728.1, 280/728.2, 280/728.3, 280/729
• US Class Current: 280/728.2
• CPC Class Codes: B60R 21/201 Packaging straps or envelopes for inflatable members
• CPC Class Codes: B60R 21/23 Inflatable members B60R21/18 takes precedence; connection to inflation fluid source retainers B60R21/217

Abstract

A packaging strap or tether for a driver side air bag cushion is integral with the material of the air bag and attached at opposite ends to a studded ring to retain the air bag in its folded condition during initial assembly and subsequent servicing of the air bag module. Made of a material similar to that of the air bag, the tether must be wide enough to control the folded cushion, but notched at a point along its length to reduce its tensile strength to such an extent that it will break on module deployment without adversely affecting module performance.

Claims

1. An air bag subassembly for installation in an air bag cushion module comprising:

an inflatable air bag and annular retainer ring coupled with said air bag, said air bag having a portion defining a fluid opening, said retainer ring being coupled with the portion of the air bag defining the fluid opening to form a mouth of the air bag, said bag being folded to provide ends of two portions each having multiple folds with ends of the folds being generally parallel, each of said portions being on an opposite side of an imaginary line which divides the ring into substantially equal parts, so that the folded bag is essentially the size of the retainer ring and has a predetermined deployment pattern;

a tether having first and second ends, means for securing the first end to the bag at one side of the retainer ring and means for attaching the tether second end to the retainer ring at an opposite side of the retainer, said tether extending in a direction substantially perpendicular to adjacent ends of the folds at said imaginary line to said opposite side of the retainer ring, said tether being made of fabric material, the second end of which is removably attached to a portion extending from the face of the retainer ring on said opposite side of said retained ring thereby to bridge across and retain the folded air bag in its folded condition against the retainer ring, said tether having a central body portion effective width that is sufficient to hold the folded air bag against the retainer ring during initial assembly and subsequent servicing of the air bag cushion module when removed from its installed position; and

said tether having a portion which releases due to inflation gas pressure during cushion deployment at a time and in a manner such that said predetermined deployment pattern remains essentially unchanged.

2. An air bag subassembly as defined in claim 1 wherein one end of the tether is integral with material forming the air bag mouth and firmly attached to the retainer ring and the other tether end is free until secured to the retainer ring.

3. An air bag subassembly as defined in claim 2 wherein the tether is an extension of the material used in forming a panel of the air bag.

4. An air bag subassembly as defined in claim 2 wherein the tether is made of a piece of material that is different from that used for the air bag and said one tether end is sewn to be integral with the air bag material.

5. An air bag assembly for installation in an air bag cushion module comprising;

an inflatable air bag and annular retainer ring coupled with said air bag, said air bag having portion defining the fluid opening, said retainer ring being coupled with the portion of the air bag defining the fluid opening to form a mouth of the air bag, said air bag being folded to be essentially the size of the retainer ring;

a tether attached at opposite sides of said retainer ring and bridging across and retaining the folded air bag in its folded condition against said retainer ring, said tether having a central body portion effective width that is sufficient to hold the folded air bag against the retainer ring during initial assembly and subsequent servicing of the air bag cushion module;

one end of the tether being integral with the material forming the air bag mouth and firmly attached to the retainer ring and the other end being free until secured to the retainer ring;

said tether having a portion which has a weakened tensile strength that breaks due to inflation gas pressure during cushion deployment without adversely affecting module performance;

said retainer ring having a circular shape and at least two spaced studs with the studs being spaced apart by about 90 degrees on opposite sides of the tether when the tether central body portion bridges across the folded air bag to retain the air bag in its folded condition; and

said other tether end being bifurcated to have two spaced tabs with an aperture in each tab surrounding a respective one of said studs.

6. An air bag subassembly as defined in claim 5 wherein the weakened portion of the tether is formed at the junction of the tabs and the central body portion of the tether.

7. An air bag assembly for installation in an air bag cushion module comprising;

an inflatable air bag and annular retainer ring coupled with said air bag, said air bag having a portion defining the fluid opening, said retainer ring being coupled with the portion of the air bag defining the fluid opening to form a mouth of the air bag, said air bag being folded to be essentially the size of the retainer ring;

a tether attached at opposite sides of said retainer ring and bridging across and retaining the folded air bag in its folded condition against said retainer ring,.said tether having a central body portion effective width that is sufficient to hold the folded air bag against the retainer ring during initial assembly and subsequent servicing of the air cushion module;

said tether having a portion which has a weakened tensile strength that breaks due to inflation gas pressure during cushion deployment without adversely affecting module performance;

the annular retainer ring having a circular shape and carries at least two studs that are spaced apart by about 90 degrees; and

one end of the tether being bifurcated to have two spaced ends with an aperture in each tab end surrounding a respective one of said studs.

8. A packaging tether for a driver side air bag cushion module, said tether being part of a subassembly comprised of a circular retainer ring having a plurality of spaced studs extending from one surface of said ring and an inflatable air bag positioned thereon, said air bag having a portion defining a fluid opening, said retainer ring being coupled with the portion defining the fluid opening to form a mouth of the air bag, said air bag being folded and positioned against a surface of said retainer ring that is opposite said one surface;

said tether having opposite ends attached to said retainer ring and extending across the folded air bag with a central portion width sufficient to provide control of the folded air bag material after the time of the fold with one tether end being integrally attached to material forming the mouth of the air bag and the other tether end having spaced tabs with an aperture in each tab that fits over one of two adjacent studs; and

a portion having an effective reduced width at some point along the tether length to reduce the tensile strength of the tether to a point that the tether will break on cushion deployment without adversely affecting module performance.

9. A packaging tether as defined in claim 8 that is cut from the material forming the air bag to be constructed integrally with the mouth of the air bag.

10. A packaging tether as defined in claim 8 that is formed from a sheet of material that is distinct from the material used to form the air bag and is sewn integrally with the material that forms the air bag mouth.