Biaxial dual stage inflator with extended gas delivery for a vehicular airbag system

• US 20030178827A1
• Filed: 03/19/2002
• 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: Wilson, Tom, Dinsdale, Paul
• Granted Patent: US 6,820,898 B2
• Time in Patent Office: Days
• US Class Current: 280/736
• 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 21/264 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
• CPC Class Codes: Y10T 137/1647 Explosive actuation

Abstract

A dual flow inflator for airbags is disclosed, together with related manufacturing, installation, and deployment methods. The inflator includes a primary gas chamber with a first exit orifice and a secondary gas chamber in gaseous communication with the primary gas chamber. The inflator also includes a flow restrictor positioned between the bas chambers. In use, the inflator provides primary and secondary flows of gas from the exit orifice. The primary gas chamber may include multiple exit orifices in order to provide axial gas flows in opposite directions upon activation so that each gas flow neutralizes the thrust of the other. The exit orifices may comprise frangible structures such as burst discs, scored surfaces, and compression closures.

Claims

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

a primary gas chamber having at least one exit orifice having an open configuration and a closed configuration;

a secondary gas chamber in gaseous communication with the primary gas chamber;

at least one flow restrictor positioned between the primary gas chamber and each secondary gas chamber; and

an initiator in communication with the interior of one of said gas chambers for selectively initiating a flow of gas through each exit orifice.

2. The dual stage biaxial inflator of claim 1, wherein the dual stage inflator comprises at least two primary gas chambers.

3. The dual stage biaxial inflator of claim 1, wherein the dual stage inflator comprises at least two secondary gas chambers.

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

5. The dual stage biaxial inflator of claim 1, wherein the initiator is in communication with a primary gas chamber.

6. The dual stage biaxial inflator of claim 1, wherein the initiator is in communication with the secondary gas chamber.

7. The dual stage biaxial inflator of claim 1, wherein an initiator is in communication with the primary gas chamber and with the secondary gas chamber.

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

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

10. The dual stage biaxial inflator of claim 9, wherein the flow restrictor comprises a burst disc.

11. The dual stage biaxial inflator of claim 10, wherein the flow restrictor further comprises a burst disc retention member.

12. The dual stage biaxial inflator of claim 9, wherein the flow restrictor comprises a scored surface.

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

14. The dual stage inflator of claim 1, wherein the inflator further comprises a gas generant for providing the flow of gas.

15. The dual-stage inflator of claim 14, wherein the gas generant comprises a mixture of gases.

16. The dual-stage inflator of claim 15, wherein the mixture of gases comprises liquefied gases.

17. The dual-stage inflator of claim 16, wherein the mixture comprises liquefied N₂O and CO₂.

18. The dual-stage inflator of claim 14, wherein the gas generant comprises a liquefied gas.

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

20. The dual-stage inflator of claim 14, wherein the gas generant is a combination of a gas and a liquefied gas.

21. The dual-stage inflator of claim 14, wherein the gas generant comprises a solid.

22. The dual-stage inflator of claim 21, wherein the gas generant further comprises a gas.

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

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

a secondary gas chamber in gaseous communication with said primary gas chamber;

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

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

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

25. The dual-stage biaxial inflator of claim 24, wherein the gas generant comprises a mixture of gases.

26. A dual stage biaxial inflator for a vehicular airbag system comprising:

a primary gas chamber having a longitudinal axis a first exit orifice at a first end of the primary gas chamber, and a second exit orifice at a second end of the primary gas chamber;

the first and second exit orifices having an open and a closed configuration;

a secondary gas chamber in gaseous communication with said primary gas chamber;

a flow restrictor positioned between the primary gas chamber and the secondary gas chamber; and

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

27. The dual stage biaxial inflator of claim 26, wherein the first and second exit orifices are substantially the same size;

such that upon activation of the inflator, the first and second primary gas flows which leave the inflator have substantially identical amounts of gas.

28. The dual stage biaxial inflator of claim 26, wherein the first and second exit orifices are of substantially different sizes;

such that upon activation of the inflator, the first and second primary gas flows which leave the inflator have substantially different amounts of gas.

29. The dual-stage biaxial inflator of claim 26, wherein the flow restrictor comprises a physical barrier configured to seal the flow restrictor (until the primary gas flows are initiated), said physical barrier comprising a frangible seal.

30. The dual stage biaxial inflator of claim 29, wherein the frangible seal is a burst disc.

31. The dual-stage biaxial inflator of claim 29, wherein the frangible seal includes a burst disc retention member configured to retain the burst disc.

32. The dual-stage biaxial inflator of claim 29, wherein the frangible seal has a scored surface.

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

34. The dual stage biaxial inflator of claim 26, wherein the initiator is in communication with the primary gas chamber.

35. The dual stage biaxial inflator of claim 26, wherein the initiator is in communication with the secondary gas chamber.

36. A dual stage biaxial inflator for a vehicular airbag system comprising:

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

a second primary gas chamber having a second longitudinal axis and a second exit orifice the second exit orifice having an open and a closed configuration;

a secondary gas chamber in gaseous communication with said first and second primary gas chambers;

a flow restrictor positioned between each primary gas chamber and the secondary gas chamber; and

an initiator in communication with the interior of one of said gas chambers, such that activation of the initiator causes the inflator to initiate a flow of gas through the first and second exit orifices.

37. The dual stage biaxial inflator of claim 36, wherein the first and second exit orifices are substantially are substantially the same size;

such that upon activation of the inflator, the first and second primary gas flows which leave the inflator have substantially identical amounts of gas.

38. The dual stage biaxial inflator of claim 36, wherein the first and second exit orifices are of substantially different sizes;

such that upon activation of the inflator, the first and second primary gas flows which leave the inflator have substantially different amounts of gas.

39. The dual stage biaxial inflator of claim 37, wherein the first and second primary gas chambers are coaxial.

40. The dual-stage biaxial inflator of claim 36, wherein the flow restrictor comprises a physical barrier which seals the flow restrictor until the primary gas flows are initiated said physical barrier comprising a frangible seal.

41. The dual stage biaxial inflator of claim 40, wherein the frangible seal is a burst disc.

42. The dual-stage biaxial inflator of claim 41, wherein the frangible seal includes a burst disc retention member configured to retain the burst disc.

43. The dual-stage biaxial inflator of claim 40, wherein the frangible seal has a scored surface.

44. The dual stage biaxial inflator of claim 40, wherein the frangible seal is a compression closure.

45. The dual stage biaxial inflator of claim 36, wherein the inflator comprises an initiator in communication with each primary gas chamber.

46. The dual stage biaxial inflator of claim 36, wherein the initiator is in communication with the secondary gas chamber.

47. A dual-stage biaxial inflator for a vehicular airbag system comprising a primary gas chamber with a first exit orifice and a second exit orifice, each exit orifice having open and closed configurations;

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

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