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

• US 6,820,898 B2
• Filed: 03/19/2002
• Issued: 11/23/2004
• Est. Priority Date: 03/19/2002
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Wilson, Tom, Dinsdale, Paul
• Primary Examiner(s): English, Peter C.
• Application Number:
  US10/100,928
• Publication Number:
  US 20030178827A1
• Time in Patent Office: 980 Days
• Field of Search: 280/737, 280/736, 280/741, 280/742, 280/728.2, 280/730.2, 280/729, 137/68.13
• US Class Current: 280/737
• 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 gas 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:

at least one primary gas chamber providing first and second exit orifices displaced from each other along a longitudinal axis of the inflator, each of the exit orifices having an open configuration and a closed configuration, wherein each exit orifice is disposed in an exterior wall of the inflator;

a secondary gas chamber;

at least one flow restrictor positioned between the at least one primary gas chamber and the secondary gas chamber to enable gas from the secondary gas chamber to reach the first and second exit orifices at a limited flow rate; and

an initiator in communication with an interior of the at least one primary gas chamber to initiate a flow of gas through at least one of the exit orifices.

2. The dual stage biaxial inflator of claim 1, wherein the dual stage inflator comprises two primary gas chambers, wherein each of the exit orifices is disposed on one of the 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 at least one of the exit orifices configured to regulate a flow rate of the flow of gas.

5. The dual stage biaxial inflator of claim 1, wherein the initiator is secured to the primary gas chamber.

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

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

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

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

10. The dual stage inflator of claim 9, wherein the gas generant comprises a mixture of gases.

11. The dual stage inflator of claim 10, wherein the mixture of gases comprises liquefied gases.

12. The dual stage inflator of claim 11, wherein the mixture comprises liquefied N₂O and CO₂.

13. The dual stage inflator of claim 9, wherein the gas generant comprises a liquefied gas.

14. The dual stage inflator of claim 13, wherein the gas generant further comprises a solid.

15. The dual stage inflator of claim 9, wherein the gas generant is a combination of a gas and a liquefied gas.

16. The dual stage inflator of claim 9, wherein the gas generant comprises a solid.

17. The dual state inflator of claim 16, wherein the gas generant further comprises a gas.

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

at least one primary gas chamber providing first and second exit orifices displaced from each other along a longitudinal axis of the inflator, each of the exit orifices having an open configuration and a closed configuration, wherein each exit orifice is disposed in an exterior wall of the inflator;

a secondary 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 at least one primary gas chamber and the secondary gas chamber to enable gas from the secondary gas chamber to reach the first and second exit orifices at a limited flow rate; and

an initiator in communication with an interior of the at least one primary gas chamber to selectively initiate a flow of gas through at least one of the exit orifices.

19. The dual stage biaxial inflator of claim 18, wherein the inflator further comprises a gas generant for providing the flow of gas out of at least one of the exit orifices.

20. The dual stage biaxial inflator of claim 19, wherein the gas generant comprises a mixture of gases.

21. 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 capable of 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 at least one of the exit orifices.

22. The dual stage biaxial inflator of claim 21, wherein the first and second exit orifices are substantially the same size;

such that upon activation of the inflator, substantially identical amounts of gas leave the inflator through the first and second exit orifices.

23. The dual stage biaxial inflator of claim 21, wherein the first and second exit orifices are of substantially different sizes;

such that upon activation of the inflator, substantially different amounts of gas leave the inflator through the first and second exit orifices.

24. The dual stage biaxial inflator of claim 21, wherein the flow restrictor comprises a physical barrier configured to seal the flow restrictor until the flow of gas is initiated, said physical barrier comprising a frangible seal.

25. The dual stage biaxial inflator of claim 24, wherein the frangible seal is a burst disc.

26. The dual stage biaxial inflator of claim 21, wherein the initiator is in communication with the primary gas chamber.

27. 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;

a plurality of flow restrictors positioned between the primary gas chambers and the secondary gas chamber to enable gas from the secondary gas chamber to reach the first and second exit orifices at a limited flow rate; and

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

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

such that upon activation of the inflator, substantially identical amounts of gas leave the inflator through the first and second exit orifices.

29. The dual stage biaxial inflator of claim 28, wherein the first and second primary gas chambers are coaxial.

30. The dual stage biaxial inflator of claim 27, wherein the first and second exit orifices are of substantially different sizes;

such that upon activation of the inflator, substantially different amounts of gas leave the inflator through the first and second exit orifices.

31. The dual stage biaxial inflator of claim 27, wherein each flow restrictor comprises a physical barrier which seals the flow restrictor until the flow of gas is initiated, said physical barrier comprising a frangible seal.

32. The dual stage biaxial inflator of claim 31, wherein the frangible seal is a burst disc.

33. The dual stage biaxial inflator of claim 27, wherein the inflator comprises an initiator in communication with each primary gas chamber.

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

a primary gas chamber with a first exit orifice at a first end and a second exit orifice at a second end, each exit orifice having open and closed configurations;

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

at least one 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 initiate a first primary flow of gas through the first exit orifice and a second primary flow of gas through the second exit orifice.