Inflatable curtain with variable seam pattern

1. An inflatable vehicle occupant protection device for helping to protect an occupant of a vehicle, said inflatable vehicle occupant protection device comprising: strands of material woven together to form both (a) overlying woven panels and (b) single layer first and second woven seams that include strands of material from each of the overlying panels, the first and second seams helping to define an inflatable volume of said inflatable vehicle occupant protection device between the overlying panels, said first seam having a weave pattern at the interface between the first seam and the inflatable volume different than the weave pattern of said second seam at the interface between the second seam and the inflatable volume, and wherein said weave pattern of said first seam has a weave density that is lower than a weave density of said weave pattern of said second seam.

2. The inflatable vehicle occupant protection device recited in claim 1 , wherein said first seam is positioned at a location on the inflatable vehicle occupant protection device such that said first seam undergoes high stresses during deployment of the inflatable vehicle occupant protection device, said second seam being positioned at a location on the inflatable vehicle occupant protection device such that said second seam undergoes stresses during deployment of the inflatable vehicle occupant protection device that are lower than the stresses on the first seam.

3. The inflatable vehicle occupant protection device recited in claim 1 , wherein said weave pattern of said first seam comprises four or more floats.

4. The inflatable vehicle occupant protection device recited in claim 1 , wherein said weave pattern of said first seam comprises a three-by-three basket weave.

5. The inflatable vehicle occupant protection device recited in claim 4 , wherein said first seam has a width of eighteen yarns.

6. The inflatable vehicle occupant protection device recited in claim 4 , wherein said three-by-three basket weave of said first seam is positioned adjacent said inflatable volume of said inflatable vehicle occupant protection device.

7. The inflatable vehicle occupant protection device recited in claim 1 , wherein said weave pattern of said second seam comprises three or less floats.

8. The inflatable vehicle occupant protection device recited in claim 1 , wherein said weave pattern of said second seam comprises a two-by-two basket weave.

9. The inflatable vehicle occupant protection device recited in claim 8 , wherein said second seam has a width of six yarns.

10. The inflatable vehicle occupant protection device recited in claim 8 , wherein said second seam further comprises a three-by-three basket weave.

11. The inflatable vehicle occupant protection device recited in claim 10 , wherein said two-by-two basket weave of said second seam surrounds said three-by-three basket weave of said second seam.

12. The inflatable vehicle occupant protection device recited in claim 10 , wherein said two-by-two basket weave of said second seam is positioned adjacent said inflatable volume of said inflatable vehicle occupant protection device and said three-by-three basket weave of said second seam is spaced from said inflatable volume of said inflatable vehicle occupant protection device.

13. The inflatable vehicle occupant protection device recited in claim 1 , wherein said overlying panels are woven in a plain weave pattern.

14. The inflatable vehicle occupant protection device recited in claim 1 , further comprising one of a urethane based and silicone based coating on said overlying woven panels.

15. The inflatable vehicle occupant protection device recited in claim 14 , wherein said coating comprises at least one of a polycarbonate polyurethane coating, a polyether based urethane coating, and a polyester based urethane coating.

16. The inflatable vehicle occupant protection device recited in claim 14 , wherein said coating comprises liquid based flame retardant.

17. The inflatable vehicle occupant protection device recited in claim 15 , wherein said coating is applied to said overlying woven panels with a weight about 27 g/m 2 or less.

18. An inflatable vehicle occupant protection device comprising strands of material woven together to form both (a) overlying woven panels and (b) single layer woven seams that include strands of material from each of the overlying panels and that help define an inflatable volume of the inflatable vehicle occupant protection device between the overlying panels, said single layer seams comprising:

at least one high stress seam that creates instances of at least four or more floats adjacent the inflatable volume of said inflatable vehicle occupant protection device; and

at least one low permeability seam that creates no more than three floats adjacent the inflatable volume of said inflatable vehicle occupant protection device.

19. The inflatable vehicle occupant protection device recited in claim 18 , wherein said high stress seam comprises a three-by-three basket weave adjacent the inflatable volume of said inflatable vehicle occupant protection device.

20. The inflatable vehicle occupant protection device recited in claim 18 , wherein said low permeability seam comprises a two-by-two basket weave adjacent said inflatable volume of said inflatable vehicle occupant protection device.

21. The inflatable vehicle occupant protection device recited in claim 20 , wherein said low permeability seam further comprises a three-by-three basket weave spaced from said inflatable volume of said inflatable vehicle occupant protection device.

22. The inflatable vehicle occupant protection device recited in claim 18 , wherein said low permeability seam comprises a three-by-three basket weave surrounded by a two-by-two basket weave.

23. The inflatable vehicle occupant protection device recited in claim 18 , wherein said high stress seam is positioned in areas of the inflatable vehicle occupant protection device susceptible to high stresses during deployment of the inflatable vehicle occupant protection device.

24. The inflatable vehicle occupant protection device recited in claim 18 , wherein said low permeability seam is positioned in areas of the inflatable vehicle occupant protection device that undergo stresses lower than stresses in areas of the inflatable vehicle occupant protection device where said high stress seam is positioned during deployment of the inflatable vehicle occupant protection device.

25. An inflatable vehicle occupant protection device comprising strands of material woven together to form both (a) overlying woven panels and (b) single layer woven seams that include strands of material from each of the overlying panels and that help to define an inflatable volume of the inflatable vehicle occupant protection device between the overlying panels, said single layer seams comprising:

a high float seam positioned in an area of the inflatable vehicle occupant protection device that undergoes high stresses; and

a low float seam positioned in an area of the inflatable vehicle occupant protection device that undergoes stresses lower than those undergone by said high float seam.