Airbag cushion comprising sewn reinforcement seams

• US 6,364,356 B1
• Filed: 09/24/1999
• Issued: 04/02/2002
• Est. Priority Date: 09/24/1999
• Status: Expired due to Fees

• Current Assignee: Milliken & Company
• Original Assignee: Milliken & Company
• Inventors: Keshavaraj, Ramesh
• Primary Examiner(s): Johnson, Brian L.
• Assistant Examiner(s): KLEBE, GERALD B
• Application Number:
  US09/406,000
• Time in Patent Office: 921 Days
• Field of Search: 280/743.1, 280/728.1, 428/36.1, 428/35.5, 428/35.2, 428/192, 428/102, 383/3, 383/107, 383/108, 156/73.1, 156/91, 156/92, 156/93
• US Class Current: 280/743.1
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/04 Dielectric heating, e.g. high-frequency welding , i.e. radio frequency welding of plastic materials having dielectric properties, e.g. PVC
• CPC Class Codes: B29C 65/72 by combined operations or combined techniques, e.g. welding and stitching
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/21 said joint lines being formed by a single dot or dash or by several dots or dashes, i.e. spot joining or spot welding
• CPC Class Codes: B29C 66/232 said joint lines being multiple and parallel, i.e. the joint being formed by several parallel joint lines
• CPC Class Codes: B29C 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/7292 coated B29C66/72941 takes precedence
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2022/02 Inflatable articles balls B29L2031/54 ; inner tyres B29L2023/245
• CPC Class Codes: B29L 2022/027 Air bags
• CPC Class Codes: B60R 2021/23514 coated fabric
• CPC Class Codes: B60R 2021/23576 Sewing
• CPC Class Codes: B60R 2021/2359 Welding
• CPC Class Codes: B60R 21/235 characterised by their material

Abstract

A method utilizing welds, reinforced with sewn seams, to adhere two fabrics together to form an inflatable airbag cushion. Although welded seams provide better and more easily produced attachment points between multiple layers of fabrics, not to mention improved manners of reducing air or gas permeability as such attachment points, the utilization of sewn seams adjacent to such welded areas provides stronger reinforcement, and thus more reliable non-permeable fabrics. Seam welding generally concerns the utilization of a film on the underside of a fabric which, upon contact with a second, film-treated fabric and upon exposure to high frequency energy, forms a bead of polymeric material at the attachment point between the two fabric layers. Lower numbers of sewn seams may be utilized to permit sufficient reinforcement if the size of the formed polymeric bead if of sufficient size to permit thorough sealing and adhesion between the fabric layers. Such a specific reinforced fabric, as well as high bead-size welded airbag fabrics are encompassed within this invention.

Claims

1. An airbag fabric for incorporation within an airbag cushion comprising at least one welded seam as a point of attachment between two fabric ends, wherein said airbag fabric also comprises at least one stitched seam located adjacent to said welded seam, wherein said welded seam comprises a polymeric bead having an average thickness of from about 2 to about 40 mils.

2. The airbag fabric of claim 1 wherein said stitched seam is formed by thread-stitching or ultrasonic-stitching.

3. The airbag fabric of claim 1 wherein said welded seam comprises a polymeric bead having an average thickness of from about 2 to about 30 mils.

8. An airbag cushion comprising the airbag fabric of claim 1.

9. An airbag cushion comprising the airbag fabric of claim 2.

10. An airbag cushion comprising the airbag fabric of claim 3.

4. An airbag fabric for incorporation within an airbag cushion comprising at least one welded seam as a point of attachment between two fabric ends, wherein said welded seam comprises a polymeric bead having an average thickness of from about 2 to about 40 mils.

5. The airbag fabric of claim 4 wherein said welded seam comprises a polymeric bead having an average thickness of from about 5 to about 40 mils.

6. The airbag fabric of claim 5 wherein said welded seam comprises a polymeric bead having an average thickness of from about 10 to about 30 mils.

7. The airbag fabric of claim 6 herein said welded seam comprises a polymeric bead having an average thickness of from about 20 to about 30 mils.

11. An airbag cushion comprising the airbag fabric of claim 4.

12. An airbag cushion comprising the airbag fabric of claim 5.

13. An airbag cushion comprising the airbag fabric of claim 6.

14. An airbag cushion comprising the airbag fabric of claim 7.