Biaxial flow inflator with independently adjusted gas orfices

• US 20030227160A1
• Filed: 06/06/2002
• Published: 12/11/2003
• Est. Priority Date: 06/06/2002
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Green, David J., Rink, Karl K., Dinsdale, Paul
• Granted Patent: US 6,854,763 B2
• Time in Patent Office: Days
• US Class Current: 280/739
• CPC Class Codes: B60R 2021/2612 Gas guiding means, e.g. ducts
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2685 comprising a plurality of pressure chambers
• CPC Class Codes: B60R 21/232 Curtain-type airbags deploying mainly in a vertical direction from their top edge
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10

Abstract

An airbag or inflatable curtain inflator for producing two differing gas flows is disposed. The inflator has a gas chamber, a first orifice, and a second orifice. The first orifice has a different effective cross-sectional area than the second orifice. The two different cross-sectional areas allow the first orifice to produce a mass flow rate of gas that is different from the second orifice. The mass flow rates of gas may be related to the volume of an inflatable curtain into which the gas is ejected. Thus, two differently sized volumes of an inflatable curtain may be simultaneously inflated with a single inflator.

Claims

1. An inflator for a vehicular airbag system, the inflator comprising:

a gas chamber having an open state and a sealed state;

a first orifice fluidly coupled to the gas chamber, wherein the first orifice has a first effective cross-sectional area;

a second orifice fluidly coupled to the gas chamber, wherein the second orifice has a second effective cross-sectional area, and wherein the first effective cross-sectional area is different from the second effective cross-sectional area.

2. The inflator, as recited in claim 1, wherein the first orifice is coupled to a first volume and the second orifice is coupled to a second volume.

3. The inflator, as recited in claim 2, further comprising a gas generant disposed within the gas chamber.

4. The inflator, as recited in claim 3, wherein the gas generant is selected from the group consisting of a compressed gas, a solid, and a liquid.

5. The inflator, as recited in claim 3, wherein in the open state the gas generant provides an inflationary gas flow into the first volume and the second volume.

6. The inflator, as recited in claim 3, wherein the first volume and the second volume are different sizes.

7. The inflator, as recited in claim 6, wherein during an initiation sequence of the inflator, the first volume and the second volume inflate substantially simultaneously.

8. The inflator, as recited in claim 3, wherein the first volume and the second volume are separate inflatable curtains.

9. The inflator, as recited in claim 3, wherein the first volume and the second volume are separate sections of a single inflatable curtain.

10. The inflator, as recited in claim 9, wherein the first volume and the second volume are in fluid communication.

11. The inflator as recited in claim 2, wherein the gas chamber has a longitudinal axis.

12. The inflator, as recited in claim 11, wherein the gas chamber is generally elongated.

13. The inflator, as recited in claim 11, wherein the first orifice is positioned to eject gas in a first direction along the longitudinal axis and the second orifice is positioned to eject gas in a second direction along the longitudinal axis, wherein the first direction is substantially opposite the second direction.

14. The inflator, as recited in claim 11, wherein the first orifice is positioned to eject gas in a first direction along the longitudinal axis and the second orifice is positioned to eject gas in a second direction at an angle offset from the longitudinal axis.

15. The inflator, as recited in claim 14, wherein in the open state a thrust component along the longitudinal axis of the first orifice is partially counteracted by a thrust component along the longitudinal axis of the second orifice.

16. The inflator, as recited in claim 1, further comprising an obstruction selectively located in the first orifice to establish the first effective cross-sectional area.

17. The inflator, as recited in claim 1 further comprising an obstruction selectively located in the second orifice to establish the second effective cross-sectional area.

18. The inflator, as recited in claim 1, further comprising at least one obstruction selectively located in one of the first orifice and second orifice.

19. The inflator as recited in claim 18, wherein a first obstruction establishes the first effective cross-sectional area of the first orifice and a second obstruction establishes the second effective cross-sectional area of the second orifice.

20. The inflator, as recited in claim 18, wherein the obstruction is a pin selectively positioned within one of the first orifice and the second orifice.

21. The inflator, as recited in claim 18, wherein the obstruction is a generally circular member selectively positioned within one of the first orifice and the second orifice.

22. The inflator, as recited in claim 1, wherein the gas chamber has a first chamber and a second chamber.

23. The inflator, as recited in claim 22, wherein the first gas chamber contains a first gas generant and the second gas chamber contains a second gas generant.

24. The inflator, as recited in claim 23, wherein in the open state, gas from the first chamber ejects from the first orifice and gas from the second chamber ejects from the second orifice.

25. The inflator, as recited in claim 1, wherein the inflator has a first end and a second end, wherein the first orifice is located in the first end and the second orifice is located in the second end.

26. The inflator, as recited in claim 25, wherein the first end is angled relative to the second end, such that the inflator is substantially thrust neutral along a single axis.

27. An inflator for a vehicular airbag system, the inflator comprising:

a gas chamber having a first end and a second end;

a first orifice fluidly coupled to the gas chamber, wherein the first orifice is located in the first end of the inflator;

a second orifice fluidly coupled to the gas chamber, wherein the second orifice is located in the second end of the inflator; and

a venting orifice selectively located in one of the first end and the second end, wherein the venting orifice is positioned to divert an amount of gas away from one of the first orifice and the second orifice.

28. The inflator, as recited in claim 27, further comprising an inflatable curtain having a first inlet port and a second inlet port.

29. The inflator, as recited in claim 28, wherein the first orifice is fluidly coupled to the first inlet port and the second orifice is fluidly coupled to the second inlet port.

30. The inflator, as recited in claim 29, wherein the venting orifice is not in fluid communication with the inflatable curtain.

31. An inflator for a vehicular airbag system, the inflator comprising:

a gas chamber containing a gas generant;

a first orifice fluidly coupled to the gas chamber;

a second orifice fluidly coupled to the gas chamber; and

an initiator coupled to the gas chamber, wherein the initiator is configured to initiate production of gas at a pressure above ambient within the gas chamber at an initiation moment, such that after the initiation moment the first orifice ejects gas at a first mass flow rate and the second orifice ejects gas at a second mass flow rate, wherein the first mass flow rate is different than the second mass flow rate.

32. The inflator, as recited in claim 31, wherein the inflator is coupled to an inflatable curtain, wherein the inflatable curtain has a first volume and a second volume.

33. The inflator, as recited in claim 32, wherein the first mass flow rate is sufficient to inflate the first volume of the inflatable curtain and the second mass flow rate is sufficient to inflate the second volume of the inflatable curtain.

34. The inflator, as recited in claim 33, wherein the first volume and second volume are different sizes.

35. The inflator, as recited in claim 31, wherein the gas chamber has a first chamber and a second chamber.

36. The inflator, as recited in claim 35, wherein at the initiation moment gas from the first chamber ejects from the first orifice and gas from the second chamber ejects from the second orifice.

37. The inflator, as recited in claim 36, wherein the gas generant in the first chamber has a different composition than the gas generant in the second chamber.

38. An inflator for a vehicular airbag system, the inflator comprising:

a first inflator having a first gas chamber and a first orifice, wherein the first gas chamber is configured to generate a gas pressure above the ambient pressure, such that a first gas flow ejects from the first orifice;

a second inflator having a second gas chamber and a second orifice, wherein the second gas chamber is configured to generate a gas pressure above the ambient pressure, such that a second gas flow ejects from the second orifice, wherein the first gas flow has a different flow rate than the second gas flow; and

a coupling member for maintaining the first inflator and the second inflator in a generally fixed relationship.

39. The inflator, as recited in claim 38, wherein the first inflator and the second inflator have a common initiator.

40. The inflator, as recited in claim 38, wherein the first inflator and the second inflator are position within a single inflatable curtain.

41. The inflator, as recited in claim 40, wherein the inflatable curtain has a first volume and a second volume.

42. The inflator, as recited in claim 41, wherein the first gas flow is configured to eject into the first volume and the second gas flow is configured to eject into the second volume.

43. The inflator, as recited in claim 38, wherein the first gas flow inflates a first inflatable curtain and the second gas flow inflates a second inflatable curtain.

44. The inflator, as recited in claim 38, wherein the coupling member maintains the first inflator and the second inflator on a single axis.