Hybrid inflator

• US 5,788,275 A
• Filed: 07/11/1996
• Issued: 08/04/1998
• Est. Priority Date: 03/18/1994
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: OEA Incorporated (Autoliv Incorporated)
• Inventors: Baglini, James L., Hamilton, Brian K., Renz, Robert N., Parks, Brent A., Grages, Dean W., Butt, Ron J.
• Primary Examiner(s): English, Peter C.
• Application Number:
  US08/680,273
• Time in Patent Office: 754 Days
• Field of Search: 280/737, 280/736, 280/741, 280/742, 280/740, 137/68.13, 137/68.3, 222/5, 222/3
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/26094 characterised by fluid flow controlling valves
• 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: C06B 45/10 the organic component containing a resin
• CPC Class Codes: C06D 5/00 Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets explosive compositions containing an oxidizer, fuels for rocket engines intended for reaction with an oxidant other than air C06B
• CPC Class Codes: C06D 5/06 by reaction of two or more solids
• CPC Class Codes: C06D 5/10 by reaction of solids with liquids
• CPC Class Codes: Y10T 137/1647 Explosive actuation

Abstract

Hybrid inflators for an inflatable safety system are disclosed. In one embodiment, the hybrid inflator uses a dual function initiator in that the combustion products from the initiator both ignite the propellant by direct contact therewith and propel a projectile through a outlet closure disk to release the stored pressurized medium. In another embodiment, the hardware configuration of the hybrid inflator allows the propellant to be loaded into the inflator after all hardware connections proximate the propellant, which require a weld, have in fact been welded. In another embodiment, the main inflator outlet closure disk is disposed at substantially a mid portion of the inflator. In another embodiment, the propellant gases are required to flow from the combustion chamber and into the stored gas housing prior to exiting the inflator, such by using a projectile to rupture the main inflator outlet closure disk and to thereafter seal the gas generator.

Claims

1. An inflator for an inflatable safety system, comprising:

an inflator housing including first and second ends separated by a first distance;

a pressurized medium contained within at least said inflator housing;

a housing assembly interconnected with said inflator housing and with said housing assembly comprising first and third chambers;

a gas generator comprising a gas generator housing interconnected with said inflator housing and a gas-generating material disposed within said gas generator housing, said gas generator housing being part of said housing assembly and defining at least portions of said first chamber, said gas generator housing extending from said first end of said inflator housing into an interior of said inflator housing, wherein said gas generator further comprises a transfer housing and said gas-generating material being disposed between said transfer housing and said gas generator housing, said transfer housing comprising a plurality of transfer housing ports fluidly interconnecting said transfer housing with said gas generator housing;

a second chamber defined between said inflator housing and said housing assembly;

an outlet passage fluidly interconnectable with at least one of said inflator housing and said gas generator housing, said outlet passage extending at least to said second end of said inflator housing;

a first closure disk which seals said outlet passage;

a projectile aligned with said first closure disk;

means for generating combustion products to ignite said gas-generating material, said transfer housing being fluidly interconnectable with said means for generating combustion products, wherein said gas generator housing further comprises first and second gas generator ends and a gas generator sidewall and said means for generating combustion products being disposed substantially on said first gas generator end in at least partial alignment with said transfer housing and said gas generator housing comprising a plurality of gas generator outlet ports disposed on said generator sidewall;

means for propelling said projectile at least partially through said first closure disk, said means for propelling comprising said means for generating combustion products; and

means for substantially preventing direct fluid communication between said first and third chambers when gases are generated upon ignition of said gas-generating material and in which substantially all of said gases are forced to flow from said first chamber, then into said second chamber, and then into said third chamber.

2. An inflator, as claimed in claim 1, wherein:

said outlet passage comprises a first portion disposed within said inflator housing and a second portion disposed exteriorly of said inflator housing.

3. An inflator, as claimed in claim 1, wherein:

said outlet passage comprises a diffuser disposed exteriorly of said inflator housing.

4. An inflator, as claimed in claim 1, wherein:

said outlet passage comprises first and second portions disposed within said inflator housing, said first portion having a first effective diameter and said second portion having a second effective diameter greater than said first effective diameter, wherein a flow from said inflator housing first flows through said first portion of said outlet passage and then through said second portion of said outlet passage.

5. An inflator, as claimed in claim 1, wherein:

an end portion of said outlet passage comprises a divergent configuration.

6. An inflator, as claimed in claim 1, wherein:

said first closure disk being disposed within said inflator housing at an intermediate location between said first and second ends of said inflator housing.

7. An inflator, as claimed in claim 6, wherein:

said intermediate location comprises said first closure disk being spaced at least about 40% of said first distance from each of said first and second ends of said inflator housing.

8. An inflator, as claimed in claim 1, wherein:

said projectile is at least partially disposed within said gas generator housing.

9. An inflator, as claimed in claim 1, wherein:

said projectile is exposed to said pressurized medium before activation of said means for generating combustion products.

10. An inflator, as claimed in claim 1, wherein:

said second end of said gas generator housing comprises a projectile aperture, wherein a remainder of said second end of said gas generator housing is substantially closed, said projectile being slidably received in said projectile aperture.

11. An inflator, as claimed in claim 10, wherein:

said projectile comprises first and second projectile portions, said second projectile portion having a larger effective diameter than said first projectile portion with said first projectile portion being disposed between said first closure disk and said second projectile portion, said second projectile portion substantially sealing said projectile aperture some time after activation of said means for propelling.

12. An inflator, as claimed in claim 1, further comprising;

means for providing fluid communication between said gas generator and said inflator housing, said means for providing fluid communication consisting essentially of said plurality of gas generator outlet ports.

13. An inflator for an inflatable safety system, comprising:

an inflator housing comprising a sidewall and first and second ends separated by a first distance, said inflator housing defining a central longitudinal axis extending between said first and second ends and all points on said central longitudinal axis being equi-distant from said inflator housing sidewall;

a pressurized medium disposed within at least said inflator housing;

a housing assembly interconnected with said inflator housing, said housing assembly comprising first and third chambers;

a second chamber defined between said inflator housing and said housing assembly;

a gas generator comprising a gas generator housing and a gas-generating material, said gas generator housing being part of said housing assembly and being interconnected with and disposed within said inflator housing and said gas-generating material being disposed within said gas generator housing;

an outlet passage fluidly interconnectable with at least one of said inflator housing and said gas generator housing and being at least partially disposed within said inflator housing;

a first closure disk having a center which seals said outlet passage and being disposed within said inflator housing at an intermediate location between said first and second ends of said inflator housing, said center of said first closure disk being located more adjacent to said central longitudinal axis than to said inflator housing sidewall, said intermediate location comprising said first closure disk being spaced at least about 40% of said first distance from each of said first and second ends of said inflator housing;

means for substantially preventing direct fluid communication between said first and third chambers when gases are generated upon ignition of said gas-generating material and in which substantially all of said gases are forced to flow from said first chamber, then into said second chamber, and then into said third chamber; and

at least one outlet port fluidly communicable with said outlet passage and being adjacent said second end of said inflator housing from which said gases escape from said inflator housing upon activation of said gas-generating material.

14. An inflator, as claimed in claim 13, wherein:

said outlet passage is at least partially aligned with said gas generator housing.

15. An inflator, as claimed in claim 13, wherein:

said gas generator housing extends from said first end of said inflator housing into an interior portion of said inflator housing, said outlet passage being interconnected with said gas generator housing within said interior of said inflator housing and extending through said second end of said inflator housing.

16. An inflator, as claimed in claim 13, wherein:

said outlet passage comprises a first portion disposed within said inflator housing and a second portion disposed exteriorly of said inflator housing.

17. An inflator, as claimed in claim 13, wherein:

said outlet passage comprises a diffuser including said one outlet port disposed exteriorly of said inflator housing.

18. An inflator, as claimed in claim 13, wherein:

said outlet passage comprises first and second portions disposed within said inflator housing, said first portion having a first effective diameter and said second portion having a second effective diameter greater than said first effective diameter, wherein a flow from said inflator housing first flows through said first portion of said outlet passage and then through said second portion of said outlet passage.

19. An inflator, as claimed in claim 13, wherein:

an end portion of said outlet passage comprises a divergent configuration.

20. An inflator, as claimed in claim 13, further comprising:

a projectile at least partially aligned with said first closure disk;

means for generating combustion products;

means for providing said combustion products into direct contact with said gas-generating material to ignite said gas-generating material; and

means for propelling said projectile at least partially through said first closure disk, said means for propelling comprising said means for generating combustion products.

21. An inflator, as claimed in claim 20, wherein:

said projectile is at least partially disposed within said gas generator housing.

22. An inflator, as claimed in claim 21, wherein:

said gas generator housing comprises at least one gas generator outlet port which fluidly interconnects said gas generator housing and said inflator housing, whereby said projectile is exposed to said pressurized medium before activation of said means for generating combustion products.

23. An inflator, as claimed in claim 20, wherein:

said means for providing said combustion products into direct contact with said gas-generating material comprises a combustion products transfer housing, said gas-generating material being disposed between said transfer housing and said gas generator housing, said transfer housing comprising a plurality of transfer housing ports fluidly interconnecting said transfer housing with said gas generator housing.

24. An inflator, as claimed in claim 20, wherein:

said gas generator housing comprises first and second generator ends and a generator sidewall, said means for generating combustion products being disposed substantially on said first generator end and said projectile interfacing with said second generator end and being disposed between said means for generating combustion products and said first closure disk.

25. An inflator, as claimed in claim 24, wherein:

said second generator end comprises a projectile aperture, wherein a remainder of said second end of said gas generator housing is substantially closed, said projectile being slidably received in said projectile aperture.

26. An inflator, as claimed in claim 25, wherein:

said projectile comprises first and second projectile portions, said second projectile portion having a larger effective diameter than said first projectile portion with said first projectile portion being disposed between said first closure disk and said second projectile portion, said second projectile portion substantially sealing said projectile aperture some time after activation of said means for propelling.

27. An inflator, as claimed in claim 20, wherein:

said gas generator housing extending from said first end of said inflator housing into an interior of said inflator housing, said outlet passage being interconnected with said gas generator housing within said interior of said inflator housing and extending through said second end of said inflator housing;

said means for providing said combustion products into direct contact with said gas-generating material comprises a combustion projects transfer housing, said gas-generating material being disposed between said transfer housing and said gas generator housing, said transfer housing comprising a plurality of ports fluidly interconnecting said transfer housing with said gas generator housing; and

said gas generator housing further comprises first and second generator ends and a generator sidewall, said means for generating combustion products being disposed substantially on said first generator end in at least partial alignment with said transfer housing, said projectile interfacing with said second generator and in at least partial alignment with said transfer housing and said first closure disk, and said gas generator housing comprising a plurality of gas generator outlet ports disposed on said generator sidewall.

28. An inflator, as claimed in claim 27, further comprising:

means for providing fluid communication between said gas generator and said inflator housing, said means for providing fluid communication consisting essentially of said plurality of gas generator outlets parts.

29. An inflator for an inflatable safety system comprising an inflatable bag, said inflator comprising:

a first housing having a first end and a second end;

a second housing assembly interconnected with said first housing, said second housing assembly comprising first and third chambers, said first housing being disposed about said second housing assembly and spaced from said second housing assembly;

a second chamber defined between said first housing and said second housing assembly;

a first port on said second housing assembly interconnecting said first chamber and said second chamber, wherein said first chamber and said second chamber are in constant fluid communication;

a gas-generating material disposed within said first chamber;

a pressurized medium contained within said first, second and third chambers;

an outlet to the inflatable ba located adjacent said second end of said first housing;

a first closure disk disposed between said third chamber and said second end of said first housing and in which said first closure disk is rupturable after said gas-generating material is ignited;

an activation assembly located adjacent said first end of said first housing for igniting said gas-generating material; and

means for substantially preventing direct fluid communication between said first and third chambers when gases are generated upon ignition of said gas-generating material and in which substantially all of said gases are forced to flow from said first chamber, then into said second chamber, and then into said third chamber, wherein said gas-generating material is disposed between said means for substantially preventing and said first end of said first housing, said means for substantially preventing direct fluid communication comprising a partition disposed within said second housing assembly which separates said first chamber from said third chamber, an aperture extending through said partition, and a projectile slidably received within said aperture.

30. An inflator, as claimed in claim 29, wherein:

said first housing is substantially cylindrical.

31. An inflator, as claimed in claim 29, wherein:

said second housing assembly is substantially concentrically disposed within said first housing.

32. An inflator, as claimed in claim 29, wherein:

said means for substantially preventing direct fluid communication comprises means for sealing said projectile against said partition.

33. An inflator, as claimed in claim 29, wherein:

said means for substantially preventing direct fluid communication comprises a partition disposed within said second housing assembly and a projectile having a first end and a second end, with said projectile first end being more adjacent to said first housing first end than said first housing second end and in which said projectile first end remains more adjacent to said first housing first end than said first housing second end after igniting said gas-generating material.

34. An inflator, as claimed in claim 29, wherein:

said activation assembly is used in rupturing said first closure disk.

35. An inflator, as claimed in claim 29, wherein:

said pressurized medium is in communication with said gas-generating material before said gas-generating material is ignited.

36. An inflator for an inflatable safety system comprising an inflatable bag, said inflator comprising:

a first housing having a first end and a second end;

a second housing assembly interconnected with said first housing, said second housing assembly comprising first and third chambers, said first housing being disposed about said second housing assembly and spaced from said second housing assembly;

a second chamber defined between said first housing and said second housing assembly;

a first port on said second housing assembly interconnecting said first chamber and said second chamber, wherein said first chamber and said second chamber are in constant fluid communication;

a gas-generating, material disposed within said first chamber;

a pressurized medium contained within said first, second and third chambers;

an outlet to the inflatable bag located adjacent said second end of said first housing, said second housing assembly further including means for carrying gases generated upon ignition of said gas-generating material from said third chamber towards said outlet and in which the length of said means for carrying is greater than each of the lengths of said first and third chambers;

a first closure disk disposed between said third chamber and said second end of said first housing and in which said first closure disk is rupturable after said gas-generating material is ignited;

an activation assembly located adjacent said first end of said first housing for igniting said gas-generating material; and

means for substantially preventing direct fluid communication between said first and third chambers when gases are generated upon ignition of said gas-generating material and in which substantially all of said gases are forced to flow from said first chamber, then into said second chamber, and then into said third chamber, wherein said gas-generating material is disposed between said means for substantially preventing and said first end of said first housing.

37. An inflator, as claimed in claim 36, wherein:

said means for carrying includes an afterburner tube substantially axially aligned with said first and third chambers.

38. An inflator, as claimed in claim 36, wherein:

said means for substantially preventing direct fluid communication comprises a projectile that moves after said gas-generating material is ignited.