Air bag cushion including break-away tethers

• US 20020175511A1
• Filed: 05/17/2002
• Published: 11/28/2002
• Est. Priority Date: 05/23/2001
• Status: Active Grant

• Current Assignee: Autoliv AB (Autoliv Incorporated)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Hawthorn, Laura Adelle, Lyons, Sonya Ann, Dunkle, Stephanie L.
• Granted Patent: US 7,134,691 B2
• Time in Patent Office: Days
• US Class Current: 280/743.2
• CPC Class Codes: B60R 2021/23382 Internal tether means
• CPC Class Codes: B60R 21/205 in dashboards
• 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

An automotive air bag assembly including a tethering element providing shape definition across the air bag. The tethering element may be seamed to itself or to other tethering elements by an attachment seam to reduce the effective operative length of the tethering element and to move the axis of rotation for the air bag rearward. The attachment seam is adapted to separate upon development of adequate pressures within the air bag.

Claims

1. An automotive air bag assembly comprising:

an inflatable air bag cushion including a mouth portion in fluid communication with a gas emitting inflator;

a first shape restricting tethering element disposed within the air bag cushion and extending across an interior portion of the air bag cushion; and

at least a second shape restricting tethering element disposed within the air bag cushion and extending across an interior portion of the air bag cushion, wherein at least a portion of the second shape restricting tethering element is normally disposed below the first shape restricting tethering element when the air bag cushion is in a fully inflated condition and wherein the fist shape restricting tethering element is releaseably attached to the second shape restricting tethering element by a break-away attachment seam wherein the break-away attachment seam is adapted to secure the first shape restricting tethering element to the second shape restricting tethering element at pressures within the air bag cushion below a predefined level during initial inflation of the air bag cushion and wherein the break-away attachment seam is adapted to separate upon the development of a pressure within the air bag cushion exceeding said predefined level following initial inflation such that the first shape restricting tethering element is disengaged from the second shape restricting tethering element at the location of the break-away attachment seam following initial inflation.

2. The assembly according to claim 1, wherein the first shape restricting tethering element and the second shape restricting tethering element have extended operative lengths following disengagement such that tension is maintained within the first shape restricting tethering element and the second shape restricting tethering element when the air bag cushion is fully inflated.

3. The assembly according to claim 1, wherein the first shape restricting tethering element and the second shape restricting tethering element comprise elongate straps.

4. The assembly according to claim 3, wherein said elongate straps comprise textile fabric.

5. The assembly according to claim 3, wherein at least one of the first shape restricting tethering element and the second shape restricting tethering element is operatively attached to an impact face portion of the air bag cushion so as to contour the shape of the impact face portion during inflation.

6. The assembly according to claim 1, wherein the first shape restricting tethering element is releaseably attached to the second shape restricting tethering element at an attachment location disposed within the interior portion of the air bag cushion substantially rearward of the mouth portion.

7. The assembly according to claim 6, wherein the first shape restricting tether element and the second shape restricting tether element form a multi-layer pleat structure at the attachment location and wherein the break-away attachment seam comprises a substantially “

V”

shaped attachment seam extending through layers of the pleat structure.

8. The assembly according to claim 7, wherein the substantially “

V”

shaped attachment seam is oriented within the pleat structure such that upon development of pressure within the air bag cushion exceeding said predefined level the “

V”

shaped attachment seam undergoes progressive separation commencing at the apex of the “

V”

shaped attachment seam.

15. The assembly according to claim 1, wherein the tethering web is characterized by an operative length following separation of the break-away attachment seam disengagement such that tension is maintained within the tethering web when the air bag cushion is fully inflated.

9. An automotive air bag assembly comprising:

an inflatable air bag cushion including a mouth portion in fluid communication with a gas emitting inflator;

a first shape restricting tethering element comprising an elongate strap disposed within the air bag cushion and extending across an interior portion of the air bag cushion; and

at least a second shape restricting tethering element comprising an elongate strap disposed within the air bag cushion and extending across an interior portion of the air bag cushion, wherein at least a portion of the second shape restricting tethering element is normally disposed below the first shape restricting tethering element when the air bag cushion is in a fully inflated condition and wherein the fist shape restricting tethering element is releaseably attached to the second shape restricting tethering element by a break-away attachment seam at an attachment location disposed within the interior portion of the air bag cushion substantially rearward of the mouth portion, the break-away attachment seam being adapted to secure the first shape restricting tethering element to the second shape restricting tethering element at pressures within the air bag cushion below a predefined level during initial inflation of the air bag cushion and wherein the break-away attachment seam is adapted to separate upon the development of a pressure within the air bag cushion exceeding said predefined level following initial inflation such that the first shape restricting tethering element is disengaged from the second shape restricting tethering element at the location of the break-away attachment seam following initial inflation and wherein the first shape restricting tether element and the second shape restricting tether element form a multi-layer pleat structure at the attachment location and wherein the break-away attachment seam comprises a substantially “

V”

shaped attachment seam extending through layers of the pleat structure.

10. The assembly according to claim 9, wherein the first shape restricting tethering element and the second shape restricting tethering element have extended operative lengths following disengagement from one another such that tension is maintained within the first shape restricting tethering element and the second shape restricting tethering element when the air bag cushion is fully inflated.

11. The assembly according to claim 9, wherein said elongate straps comprise textile fabric.

12. The assembly according to claim 9, wherein at least one of the first shape restricting tethering element and the second shape restricting tethering element is operatively attached to an impact face portion of the air bag cushion so as to contour the shape of the impact face portion during inflation.

13. The assembly according to claim 9, wherein the substantially “

V”

shaped attachment seam is oriented within the pleat structure such that upon development of pressure within the air bag cushion exceeding said predefined level the “

V”

shaped attachment seam undergoes progressive separation commencing at the apex of the “

V”

shaped attachment seam.

16. The assembly according to claim 14, wherein the tethering web comprises textile fabric.

17. The assembly according to claim 14, wherein the multi-layered pleat structure is disposed within the interior portion of the air bag cushion at a location substantially rearward of the mouth portion.

18. The assembly according to claim 17, wherein the break-away attachment seam comprises a substantially “

V”

shaped attachment seam.

19. The assembly according to claim 18, wherein the substantially “

V”

shaped attachment seam is a sewn seam.

14. An automotive air bag assembly comprising:

an inflatable air bag cushion including a mouth portion in fluid communication with a gas emitting inflator; and

at least one shape restricting tethering web element disposed within the air bag cushion and extending across an interior portion of the air bag cushion below the mouth portion, the tethering web including at least one gas transmission opening disposed through the tethering web, wherein the tethering web is folded upon itself in a multi-layered pleat structure at least partially obstructing the gas transmission opening and wherein a break-away attachment seam extends across the multi-layered pleat structure, the break-away attachment seam being adapted to hold the multi-layered pleat structure in a folded condition at pressures within the air bag cushion below a predefined level during initial inflation of the air bag cushion and wherein the break-away attachment seam is adapted to separate upon the development of a pressure within the air bag cushion exceeding said predefined level following initial inflation such that the multi-layered pleat structure is at least partially unfolded to increase the operative length of the tethering web and to at least partially open the gas transmission opening.