Tether systems for inflatable cushions

1. An inflatable airbag assembly comprising:

an inflatable curtain cushion having a configuration and length such that when inflated, the cushion overlaps at least one end-pillar of a vehicle, wherein the cushion has an inflatable portion and a non-inflatable portion;

a tether strap comprising a first end opposite from a second end and a middle portion between the first end and the second end,

wherein the first end of the tether strap is attached to the cushion and the second end is configured to be attached to a vehicle structure, and

wherein the tether strap has a fixed length between its first end and its second end; and

a sliding member coupled to the non-inflatable portion of the cushion at a coupling point such that the sliding member moves with the cushion when the cushion is deployed,

wherein the sliding member and the middle portion of the tether strap are positioned for the middle portion to slide in the sliding member;

wherein the assembly is configured such that when the cushion is rolled and ready for installation in a vehicle, the sliding member, the second end and at least a portion of the middle portion of the tether strap are not rolled up with the cushion;

wherein the assembly is configured such that deployment of the cushion increases the tension of the tether strap due to the fixed length of the tether strap and the configuration of the coupling point and the sliding member.

2. The airbag assembly of claim 1 , wherein the second end of the tether strap is configured to be attached to the end-pillar that the cushion overlaps.

3. The airbag assembly of claim 2 , wherein the first end of the tether strap is at least partially located on a back side of the cushion.

4. The airbag assembly of claim 1 , wherein the coupling point is between an upper portion of the cushion and a lower portion of the cushion, wherein the first end of the tether strap is attached to the cushion at an attachment point, and wherein the attachment point is at a non-inflatable portion near the upper portion of the cushion.

5. The airbag assembly of claim 4 , wherein the position of the first end of the tether strap at the attachment point and the configuration of the coupling point and the sliding member permit the tether strap to have a non-linear path between the first end and the second end of the tether strap after deployment of the cushion.

6. The airbag assembly of claim 1 ,

wherein the assembly is configured such that when the cushion is in a deployed state, the increased tension of the tether strap also causes tension to be placed on the cushion.

7. The airbag assembly of claim 1 , wherein the sliding member is a ring.

8. The airbag assembly of claim 1 , wherein the first end of the tether strap is attached to a top edge of the cushion.

9. The airbag assembly of claim 1 , wherein the first end of the tether strap is attached to the cushion at an attachment point and the second end is configured to be attached to a vehicle structure via an anchor.

10. The airbag assembly of claim 1 , wherein the coupling point is located on a side edge of the cushion when the cushion is in an extended configuration.

11. The airbag assembly of claim 1 , wherein the coupling point is located on a side edge of the cushion when the cushion is in a rolled configuration.

12. The airbag assembly of claim 1 , wherein the coupling point comprises an aperture in the cushion at a non-inflatable portion.

13. The airbag assembly of claim 12 , wherein, after the cushion has been folded at a fold-line, the aperture is at least partially located at the fold-line of the cushion.

14. The airbag assembly of claim 13 , wherein the fold-line defines an outside edge and the coupling point is located at the outside edge.

15. An inflatable curtain cushion assembly, comprising:

an inflatable curtain cushion comprising an inflatable portion and a non-inflatable portion, wherein the cushion is configured such that in a deployed state, the cushion extends to at least one end-pillar of a vehicle; and

a tether strap comprising

a first end that is attached to the cushion,

a second end configured to be attached to a vehicle structure, and

a middle portion that is located between the first and second ends,

wherein the tether strap has a fixed length between its first end and its second end;

a sliding member coupled to the non-inflatable portion of the cushion at a coupling point such that the sliding member moves with the cushion when the cushion is deployed,

wherein the sliding member and the middle portion of the tether strap are positioned for the middle portion to slide in the sliding member, and

wherein the sliding member is coupled to the non-inflatable portion of the cushion via a coupling strap that is attached to the non-inflatable portion of the cushion with a looped configuration;

wherein the assembly is configured such that when the cushion is in a rolled configuration and ready for installation in a vehicle, the sliding member, at least a portion of the middle portion and the second end of the tether strap are located outside of the rolled cushion; and

wherein the assembly is configured such that, when the cushion is in a deployed state, tension of the tether strap is increased, relative to the configuration of the tether strap when the cushion is in a rolled configuration, due to the fixed length of the tether strap and the configuration of the coupling point and the sliding member.

16. The airbag assembly of claim 15 , wherein the coupling point comprises an aperture in an interior non-inflatable portion of the cushion, and wherein the aperture is at least partially located along a fold-line of the cushion.

17. The airbag assembly of claim 16 , wherein, after the cushion has been folded at the fold-line, the aperture is at least partially located at the fold-line of the cushion.

18. The airbag assembly of claim 17 , wherein after the cushion has been folded along the fold-line, the coupling strap extends through the aperture.

19. The airbag assembly of claim 15 , wherein when after the cushion has been folded along the fold-line, and after the cushion has been rolled, the coupling strap is at least partially located inside the rolled cushion.

20. The airbag assembly of claim 15 ,

wherein the sliding member is configured such that, during inflatable cushion deployment, sliding at least part of the middle portion of the tether strap through the sliding member causes tension to be placed on the cushion.

21. The airbag assembly of claim 15 , wherein the coupling point is between an upper portion of the cushion and a lower portion of the cushion, and wherein an attachment point is at a non-inflatable portion near the upper portion of the cushion.

22. The airbag assembly of claim 21 , wherein the position of the first end of the tether strap at the attachment point and the configuration of the coupling point and the sliding member permit the tether strap to have a non-linear path between the first end and the second end of the tether strap after deployment of the cushion.

23. The airbag assembly of claim 15 , wherein the sliding member comprises a ring that surrounds a part of the middle portion of the tether strap.

24. A method for tethering a curtain cushion to a pillar of a vehicle, comprising the steps of:

providing an inflatable airbag assembly comprising an inflatable curtain cushion, a tether strap and a sliding member,

wherein the cushion comprises inflatable and non-inflatable portions,

wherein the tether strap comprises a first end opposite from a second end and a middle portion between the first end and the second end,

wherein the first end of the tether strap is attached to the cushion and the second end is configured to be attached to a structure of the vehicle,

wherein the tether strap has a fixed length between its first end and its second end,

wherein the sliding member is coupled to the non-inflatable portion of the cushion at a coupling point such that the sliding member moves with the cushion when the cushion is deployed,

wherein the sliding member and the middle portion of the tether strap are positioned for the middle portion to slide in the sliding member, and

wherein the curtain is rolled such that the sliding member, the second end and at least a portion of the middle portion of the tether strap are not rolled up with the cushion;

mounting the rolled cushion adjacent a head rail of the vehicle,

wherein the rolled cushion has a configuration and length such that when inflated, the cushion overlaps at least one end-pillar of the vehicle; and

attaching the second end of the tether strap to an end-pillar of the vehicle;

wherein the assembly is configured such that deployment of the cushion increases the tension of the tether strap due to the fixed length of the tether strap and the configuration of the coupling point and the sliding member.

25. The method of claim 24 , wherein

upon deployment of the cushion, the tether strap slides through the sliding member and the tether strap adopts a non-linear configuration.

26. The method of claim 24 , wherein

the assembly is configured such that when the cushion is in a deployed state, the increased tension of the tether strap also causes tension to be placed on cushion.

27. The method of claim 24 , wherein

the coupling point is at least partially located along a fold-line of the cushion and the cushion has been folded along the fold-line prior to rolling the cushion.