Airbag cover tear seam

• US 7,748,732 B2
• Filed: 11/07/2006
• Issued: 07/06/2010
• Est. Priority Date: 11/07/2006
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Sella, Terry, Kutchey, Mike, Hoffmann, Beth
• Primary Examiner(s): Dickson; Paul N
• Assistant Examiner(s): VERLEY, NICOLE T
• Application Number:
  US11/593,769
• Publication Number:
  US 20080106076A1
• Time in Patent Office: 1,337 Days
• Field of Search: 280/728.3, 280/743.1, 280/743.2
• US Class Current: 280/728.3
• CPC Class Codes: B60R 21/201 Packaging straps or envelopes for inflatable members
• CPC Class Codes: B60R 21/205 in dashboards
• CPC Class Codes: B60R 21/2165 characterised by a tear line for defining a deployment opening

Abstract

An tear seam in a cover of an airbag includes multiple, non-intersecting slits defined in a fabric of the cover that may be woven with weft yarns oriented generally parallel to a longitudinal axis and warp yarns oriented generally transverse thereto. The multiple slits are diagonal with respect to the longitudinal axis and include end portions. The end portions of substantially all adjacent slits mutually overlap, to weaken the strength of the fabric along the tear seam.

Claims

1. A tear seam in a cover of an airbag, comprising:

a plurality of non-intersecting slits defined in a woven fabric of a cover that is woven with weft yarns oriented generally parallel to a longitudinal axis and warp yarns oriented generally transverse thereto,

wherein the plurality of slits are diagonal with respect to the longitudinal axis,

wherein the plurality of slits are positioned such that adjacent slits have a pair of overlapping end portions,

wherein each pair of overlapping end portions defines a connected portion therebetween in which the warp yarns do not continue beyond the respective pair of overlapping end portions and some of the weft yarns continue beyond the respective pair of overlapping end portions below one adjacent slit and above the other adjacent slit, and

wherein inflation of an airbag against the cover results in the separation of the weft yarns from the warp yarns along the plurality of slits without similarly separating the weft yarns from the warp yarns at the connected portions, thereby forming a plurality of tears.

2. The tear seam of claim 1, wherein the fabric comprises nylon.

3. The tear seam of claim 1, wherein the fabric comprises a polymer.

4. The tear seam of claim 1, wherein the fabric comprises yarn of at least 630 denier.

5. The tear seam of claim 1, wherein when the tear seam ruptures, the plurality of tears are generally parallel to the weft yarns that are above and below the plurality of slits.

6. The tear seam of claim 1, wherein the plurality of slits are oriented mutually parallel to each other along the longitudinal axis.

7. An airbag cover comprising:

a woven fabric comprising weft yarns running generally parallel to a longitudinal axis and warp yarns woven generally transverse therein; and

a tear seam comprising a plurality of slits defined in the fabric in spaced-apart orientation,

wherein the plurality of slits comprising adjacent slits that overlap each other at their respective end portions,

wherein the overlapping end portions of two adjacent slits define a connected portions in which the warp yarns do not continue beyond the overlapping end portions of the two adjacent slits and some of the weft yarns continue beyond the overlapping end portions of the two adjacent slits below one adjacent slit and above the other adjacent slit,

wherein each connected portion has a length L and a width W, and wherein width W is not significantly greater than length L such that the slits are slightly diagonal with respect to the longitudinal axis,

wherein inflation of an airbag against the cover results in the separation of the weft yarns from the warp yarns along the plurality of slits without similarly separating the weft yarns from the warp yarns at the connected portions, thereby rupturing the tear seam through which the airbag deploys.

8. The airbag cover of claim 7, wherein the fabric comprises a material selected from the group consisting of nylon, polymer, polyester, and combinations thereof.

9. The airbag cover of claim 8, wherein the fabric comprises yarn of at least 630 denier.

10. The airbag cover of claim 7, wherein the overlapping end portions are substantially parallel.

11. The airbag cover of claim 7, wherein the length L of each connected portion at least partially determines the strength required to rupture the tear seam.

12. The airbag cover of claim 7, wherein the slit length exceeds the length L of at least some of the plurality of connected portions.

13. The airbag cover of claim 7, wherein upon rupturing, the tear seam forms a plurality of tears oriented generally parallel to the weft yarns.

14. The airbag cover of claim 7, wherein the width W of each connected portion at least partially determines the strength required to rupture the tear seam.

15. An airbag system comprising:

an inflatable airbag;

an airbag cover comprising a woven fabric of a cover that is woven with weft yarns oriented generally parallel to a longitudinal axis and warp yarns oriented generally transverse thereto; and

a tear seam defined in the woven fabric comprising a plurality of spaced-apart, slits cut in the woven fabric such that each slit has opposing first and second sides,

wherein the plurality of slits are diagonal with respect to the longitudinal axis such that each slit is defined by discontinuous segments of the weft yarns and warp yarns,

wherein the plurality of slits are positioned such that adjacent slits have a pair of overlapping end portions, and

wherein each pair of overlapping end portions defines a connected portion therebetween in which the warp yarns do not continue beyond the respective pair of overlapping end portions and some of the weft yarns continue beyond the respective pair of overlapping end portions below one adjacent slit and above the other adjacent slit,

wherein inflation of an airbag against the cover causes the tear seam to rupture such that the woven fabric is divided into a first section and a second section to allow the deployment of the airbag through the airbag cover,

wherein the first section comprises the first side of each slit and the connected portions with the discontinuous segments of the weft yarns that previously defined the opposing second side of each respective slit extending from each of the connected portions,

wherein the second section comprises the discontinuous segments of the warp yarns of the second side of each slit as the discontinuous segments of the weft yarns that defined the second side of each slit and the discontinuous segments of the warp yarns that defined the second side of each slit have been pulled clear of each other.

16. The airbag system of claim 15, wherein the tear seam after rupturing is generally parallel to the weft yarns that are above and below the plurality of slits.

17. The airbag system of claim 15, wherein the fabric comprises a material selected from the group consisting of nylon, polymer, polyester, and combinations thereof.

18. The airbag system of claim 15, wherein the fabric comprises yarn of at least 630 denier.

19. The airbag system of claim 15, wherein the connected portions are of a length along the longitudinal axis that at least partially determines the strength required to rupture the tear seam.

20. The airbag system of claim 15, wherein the plurality of connected portions are of a width between the overlapping end portions that at least partially determines the strength required to rupture the tear seam.

21. The airbag system of claim 15, wherein each connected portion has a length L and a width W, and wherein the length L is greater than the width W.

22. The airbag system of claim 15, wherein each the tear seam further comprises a plurality of connected portions between overlapping end portions of the plurality of slits, wherein the connected portions are defined by a length along the longitudinal axis which is less than the length of at least some of the plurality of slits.

23. The airbag system of claim 15, wherein the each connected portion has a length L and a width W, and wherein width W is not significantly greater than length L.

24. An airbag cover comprising:

a portion of a woven fabric configured to contain a folded airbag therein, wherein the woven fabric is woven with weft yarns oriented generally parallel to a longitudinal axis and warp yarns oriented generally transverse thereto; and

a tear seam defined in the woven fabric comprising a plurality of spaced-apart, slits cut in the woven fabric such that each slit has opposing first and second sides,

wherein the plurality of slits are diagonal with respect to the longitudinal axis such that each slit is defined by discontinuous segments of the weft yarns and warp yarns,

wherein the plurality of slits are positioned such that adjacent slits have a pair of overlapping end portions, and

wherein each pair of overlapping end portions defines a connected portion therebetween in which the warp yarns do not continue beyond the respective pair of overlapping end portions and some of the weft yarns continue beyond the respective pair of overlapping end portions below one adjacent slit and above the other adjacent slit,

wherein inflation of an airbag against the cover causes the tear seam to rupture such that the woven fabric is divided into a first section and a second section to allow the deployment of the airbag through the airbag cover,

wherein the first section comprises the first side of each slit and the connected portions with the discontinuous segments of the weft yarns that previously defined the opposing second side of each respective slit extending from each of the connected portions,

wherein the second section comprises the discontinuous segments of the warp yarns of the second side of each slit as the discontinuous segments of the weft yarns that defined the second side of each slit and the discontinuous segments of the warp yarns that defined the second side of each slit have been pulled clear of each other.

25. The airbag cover of claim 24, wherein the tear seam after rupturing is generally parallel to the weft yarns that are above and below the plurality of slits.

26. The airbag cover of claim 24, wherein the woven fabric comprises a material selected from the group consisting of nylon, polymer, polyester, and combinations thereof.

27. The airbag cover of claim 26, wherein the woven fabric comprises yarn of about 630 denier.

28. The airbag cover of claim 24, wherein the each connected portion has a length L and a width W, and wherein the length L is greater than the width W.

29. The airbag cover of claim 24, wherein the each connected portion has a length L and a width W, and wherein width W is not significantly greater than length L.