Dual stage inflator with extended gas delivery for a vehicular airbag system

• US 20030178829A1
• Filed: 10/04/2002
• Published: 09/25/2003
• Est. Priority Date: 03/19/2002
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Dinsdale, Paul, Young, Anthony M., Green, David J.
• Granted Patent: US 7,004,500 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/23107 the bag being integrated in a multi-bag system
• CPC Class Codes: B60R 2021/23386 External tether means
• CPC Class Codes: B60R 2021/2612 Gas guiding means, e.g. ducts
• CPC Class Codes: B60R 2021/2615 for diverting the gas into a plurality of bags
• 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 21/213 in vehicle roof frames or pillars
• 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
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

A dual stage inflator for providing an extended flow of inflation gas to an airbag or inflatable curtain is disclosed. The inflator includes a first gas chamber having an exit orifice, the exit orifice having an open configuration and a closed configuration. Additionally, the inflator has a second gas chamber in gaseous communication with the first gas chamber. The first and second gas chambers are separated by a flow restrictor positioned between them. This restrictor controls the flow of gas out of the second gas chamber. The inflator includes an initiator in communication with the interior of one of the gas chambers that is configured to selectively initiate a flow of gas through the exit orifice of the first gas chamber. The exit orifice of the inflator may be disposed within an inlet port of an inflatable curtain to cause inflation gases exiting the inflator through the exit orifices to enter directly into the airbag or inflatable curtain.

Claims

1. A dual stage inflator for a vehicular airbag system, the inflator comprising:

a first gas chamber having an exit orifice, the exit orifice having an open configuration and a closed configuration;

a second gas chamber in gaseous communication with said first gas chamber;

a flow restrictor positioned between the first gas chamber and the second gas chamber; and

an initiator in communication with the interior of at least one of said gas chambers to selectively initiate a flow of gas through the exit orifice.

2. The dual-stage inflator of claim 1, wherein the initiator is in communication with the first gas chamber.

3. The dual stage inflator of claim 1, wherein the initiator is in communication with the second gas chamber.

4. The dual stage inflator of claim 1, wherein an initiator is in communication with the first gas chamber and with the second gas chamber.

5. The dual stage inflator of claim 1, wherein the flow restrictor comprises a restricted flow channel.

6. The dual stage inflator of claim 1, wherein the flow restrictor comprises a frangible seal.

7. The dual stage inflator of claim 6, wherein the flow restrictor comprises a burst disc.

8. The dual stage inflator of claim 6, wherein the flow restrictor comprises a scored surface.

9. The dual stage inflator of claim 6, wherein the flow restrictor comprises a compression seal.

10. The dual-stage inflator of claim 1, wherein the dual stage inflator further comprises a gas generant for generating the flow of gas.

11. The dual-stage inflator of claim 10, wherein the gas generant comprises a mixture of gases.

12. The dual-stage inflator of claim 10, wherein the gases are selected from the group consisting of helium, argon, N₂O, and CO₂.

13. The dual-stage inflator of claim 11, wherein the mixture of gases comprises liquefied gases.

14. The dual-stage inflator of claim 13, wherein the mixture comprises liquefied N₂O and CO₂.

15. The dual-stage inflator of claim 10, wherein the gas generant comprises a liquefied gas.

16. The dual-stage inflator of claim 15, wherein the gas generant further comprises a solid.

17. The dual-stage inflator of claim 10, wherein the gas generant comprises a combination of a gas and a liquefied gas.

18. The dual-stage inflator of claim 10, wherein the gas generant comprises a solid.

19. The dual-stage inflator of claim 18, wherein the gas generant further comprises a gas.

20. The dual-stage inflator of claim 1, wherein the exit orifice is configured to regulate the flow rate of the flow of gas.

21. The dual-stage inflator of claim 1, wherein the dual-stage inflator comprises at least two second gas chambers.

22. A dual stage inflator for a vehicular airbag system, the inflator comprising:

a first gas chamber having an exit orifice, the exit orifice having an open configuration and a closed configuration;

a second gas chamber in gaseous communication with said first gas chamber;

a flow restrictor comprising a restricted flow channel sized to limit the flow rate of the flow of gas from the second gas chamber, said flow restrictor being positioned between the first gas chamber and the second gas chamber; and

an initiator in communication with the interior of the first gas chamber to selectively initiate a flow of gas through the exit orifice.

23. The dual stage inflator of claim 22, wherein the inflator further comprises a gas generant for providing the flow of gas out of the exit orifice.

24. The dual-stage inflator of claim 23, wherein the gas generant is a mixture of gases.

25. A dual stage inflator for a vehicular airbag system, the inflator comprising:

a first gas chamber having an exit orifice, the exit orifice having an open configuration and a closed configuration;

a second gas chamber in gaseous communication with said first gas chamber;

a flow restrictor comprising a physical barrier configured to seal the flow restrictor until the flow of gas is initiated, said flow restrictor being positioned between the first gas chamber and the second gas chamber; and

an initiator in communication with the interior of the first gas chamber, to selectively initiate a flow of gas through the exit orifice.

26. The dual-stage inflator of claim 25, wherein the physical barrier comprises a frangible seal.

27. The dual stage inflator of claim 26, wherein the frangible seal is a burst disc.

28. The dual-stage inflator of claim 26, wherein the frangible seal is a scored surface.

29. The dual stage inflator of claim 26, wherein the frangible seal is a compression closure.

30. The dual stage inflator of claim 25, wherein the inflator further comprises a gas generant for providing the flow of gas.

31. The dual-stage inflator of claim 30, wherein the gas generant comprises a mixture of gases.

32. The dual-stage inflator of claim 31, wherein the gases are selected from the group consisting of helium, argon, N₂0, and CO₂.

33. The dual-stage inflator of claim 31, wherein the mixture of gases comprises liquefied gases.

34. The dual-stage inflator of claim 33, wherein the mixture comprises liquefied N₂O and CO₂.

35. The dual-stage inflator of claim 30, wherein the gas generant comprises a liquefied gas.

36. The dual-stage inflator of claim 30, wherein the gas generant further comprises a solid.

37. The dual-stage inflator of claim 30, wherein the gas generant is a combination of a gas and a liquefied gas.

38. The dual-stage inflator of claim 30, wherein the gas generant comprises a solid.

39. The dual-stage inflator of claim 38, wherein the gas generant further comprises a gas.

40. A dual-stage inflator for a vehicular airbag system, the inflator comprising:

a first gas chamber having an exit orifice, the exit orifice having an open configuration and a closed configuration, the first gas chamber further including a first initiator attached to the first gas chamber, the first initiator being configured to initiate a first flow of gas from the first gas chamber;

a second gas chamber, the second gas chamber including a second initiator attached to the second gas chamber, the second initiator being configured to initiate a second flow of gas from the second gas chamber; and

a flow restrictor positioned between the first gas chamber and the second gas chamber, wherein the flow restrictor has a closed configuration in which the first and second gas chambers are separated, and an open configuration in which the first and second gas chambers are placed in fluid communication.

41. The dual-stage inflator of claim 40, wherein the first gas chamber is placed in its closed configuration with a frangible seal.

42. The dual-stage inflator of claim 41, wherein the frangible seal is selected from the group consisting of burst discs, scored surfaces, and compression closures.

43. The dual stage inflator of claim 40, wherein the flow restrictor is placed in its closed configuration with a frangible seal.

44. The dual stage inflator of claim 43, wherein the frangible seal is selected from the group consisting of burst discs, scored surfaces, and compression closures.

45. The dual stage inflator of claim 40, wherein the inflator provides only a first flow of gas by actuating the first initiator.

46. The dual stage inflator of claim 40, wherein the inflator provides a first flow of gas by actuating the first initiator and a second flow of gas by actuating the second initiator.

47. The dual stage inflator of claim 46, wherein the second initiator is actuated after the first initiator is actuated to maintain the inflation of an airbag.

48. The dual stage inflator of claim 47, wherein the second initiator is actuated after the first initiator is actuated to reinflate an airbag.

49. A dual-stage inflator for a vehicular airbag system comprising a first gas chamber with an exit orifice with open and closed configurations;

a second gas chamber in gaseous communication with said first gas chamber, the second gas chamber including at least one flow restrictor, the flow restrictor positioned between the first gas chamber and the second gas chamber; and

an initiator positioned in the first gas chamber, wherein the initiator is in communication with the interior of the first gas chamber, and is configured to selectively initiate a flow of gas through the exit orifice.