Flexible gas generator

• US 20060157961A1
• Filed: 01/20/2006
• Published: 07/20/2006
• Est. Priority Date: 01/20/2005
• Status: Active Grant

• Current Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Burns, Sean P.
• Granted Patent: US 7,934,749 B2
• Time in Patent Office: Days
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• CPC Class Codes: B60R 2021/26082 Material
• CPC Class Codes: B60R 2021/26088 Plastic
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: B60R 21/2646 the reacting substances being supported by the inflatable member walls, or by a flexible support within it
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

In accordance with the present invention, a flexible gas generator (10) is provided which includes a first flexible housing (14) defining an interior, the first housing (14) having an exterior surface. A first flexible, porous covering (15) is positioned in contact with substantially the entire exterior surface of the first housing (14). The first housing (14) and covering (15) are positioned within a second flexible housing (12). The first (14) and second (12) housings may be formed from polymeric or metallic tubing. A second flexible, porous covering (19) may be positioned to cover substantially the entire exterior surface of the second housing (12). The flexible first covering (15) may comprise multiple layers of, for example, a braided or a mesh material. The flexible coverings (15, 19) provide structural support for the housings (12, 14) while cooling and filtering the generated gases. A series of plenums (390) may be formed between adjacent layers of the first covering and/or a series of baffles (100) may be positioned between the layers to direct the flow of inflation gases and to cool the gases. Use of flexible tubing and flexible coverings provides the gas generator with substantial flexibility.

Claims

1. A gas generator comprising:

a first flexible housing defining an interior, the first housing having an exterior surface; and

a first flexible, porous covering in contact with substantially the entire exterior surface of the first housing.

2. The gas generator of claim 1 wherein the first flexible housing is formed from a polymer material.

3. The gas generator of claim 1 wherein the first flexible housing has weakened portions formed along a length thereof, the weakened portions being configured to rupture under the pressure of combustion gases generated in the first housing.

4. The gas generator of claim 1 wherein the first flexible covering comprises at least one layer of a mesh material.

5. The gas generator of claim 4 wherein the first flexible covering comprises a plurality of layers of a mesh material, and further comprising at least one non-porous baffle element positioned between two adjacent layers of the plurality of layers of mesh material.

6. The gas generator of claim 1 wherein the first flexible covering comprises at least one layer of braided material.

7. The gas generator of claim 1 further comprising a second flexible housing defining an interior, and wherein the first housing and the first flexible covering are positioned within the second housing interior.

8. The gas generator of claim 7 wherein the second flexible housing is formed from a polymer material.

9. The gas generator of claim 1 further comprising a second flexible porous covering substantially enclosing the first covering.

10. The gas generator of claim 9 wherein the second flexible covering comprises at least one layer of a mesh material.

11. The gas generator of claim 9 wherein the second covering comprises a plurality of layers of a mesh material.

12. The gas generator of claim 11 further comprising at least one non-porous baffle element positioned between two adjacent layers of the plurality of layers of mesh material.

13. The gas generator of claim 11 further comprising a plenum formed between adjacent layers of multiple pairs of adjacent layers of at least a portion of the plurality of layers.

14. The gas generator of claim 7 wherein the. first housing has at least one orifice formed therealong to enable fluid communication between the first housing interior and an exterior of the first housing, the at least one first housing orifice opening from the housing interior toward a first side of the gas generator, and wherein the second flexible housing has at least one orifice formed therealong to enable fluid communication between the second housing interior and an exterior of the second housing, the at least one second housing orifice opening from the second housing interior toward a second side of the gas generator.

15. The gas generator of claim 14 wherein the first flexible covering is positioned along a gas flow path between the at least one first housing orifice and the at least one second housing orifice, and wherein gases generated by combustion of a gas generant composition positioned within the first housing interior flow through the at least one first housing orifice and through the first flexible covering to exit the second housing through the at least one second housing orifice.

16. The gas generator of claim 7 wherein the second housing has an exterior surface, and further comprising a second flexible porous covering in contact with substantially the entire exterior surface of the second housing.

17. The gas generator of claim 16 further comprising a third flexible housing defining an interior, and wherein the second housing and the second flexible covering are positioned within the third housing interior.

18. The gas generator of claim 7 wherein the first housing and the second housing are both formed from a metallic material.

19. The gas generator of claim 7 wherein the second flexible housing is formed from a polymer material.

20. The gas generator of claim 19 wherein the first flexible housing is formed from a polymer material.

21. The gas generator of claim 19 wherein the first flexible housing is formed from a metallic material.

22. The gas generator of claim 14 wherein the second side of the gas generator is opposite the first side of the gas generator.

23. The gas generator of claim 14, wherein a direction of flow of inflation gas exiting the at least one second housing orifice is angularly spaced apart approximately 180 degrees from a direction of flow of inflation gas exiting the at least one first housing orifice.

24. The gas generator of claim 1 wherein the at least one second housing orifice is formed along a first portion of a length of the gas generator.

25. The gas generator of claim 24 wherein the at least one first housing orifice is formed along a second portion of the length of the gas generator, and wherein the second portion is spaced apart from the first portion.

28. An airbag system comprising the gas generator of claim 1 and at least one airbag coupled to the gas generator so as to provide fluid communication between the gas generator and an interior of the airbag upon activation of the gas generator.

29. The airbag system of claim 28 further comprising a crash event sensor operating in association with a crash sensor algorithm that signals activation of the airbag system in the event of a collision.

30. The airbag system of claim 28 wherein the at least one airbag is a side curtain airbag.

31. The airbag system of claim 28 wherein the at least one airbag is a head curtain airbag.

32. A vehicle occupant restraint system including the gas generator of claim 1.

33. The vehicle occupant restraint system of claim 32 further comprising a safety belt assembly including a housing and a safety belt extending from the housing.

34. The vehicle occupant restraint system of claim 32 further comprising a crash event sensor operating in association with a crash sensor algorithm that signals activation of the vehicle occupant restraint system in the event of a collision.

26. A method for manufacturing a gas generator comprising the steps of:

providing a first flexible housing defining an interior, the first housing having an exterior surface;

providing a first flexible, porous covering in contact with substantially the entire exterior surface of the first housing;

providing a second flexible, porous covering comprising a plurality of layers substantially enclosing the first covering;

providing a second flexible housing defining an interior; and

positioning the first housing, the first covering, and the second covering within the second housing interior such that a plenum is formed between adjacent layers of multiple pairs of adjacent layers of at least a portion of the plurality of layers of the second covering.

27. A gas generator manufactured according to the method of claim 26.