Hybrid inflator with diffuser end translating initiator boss

• US 5,890,735 A
• Filed: 01/13/1997
• Issued: 04/06/1999
• Est. Priority Date: 01/13/1997
• Status: Expired due to Fees

• Current Assignee: Morton International Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Smith, Bradley W.
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/782,815
• Time in Patent Office: 813 Days
• Field of Search: 102/530, 102/531, 280/736, 280/737, 280/740, 280/741, 280/742, 222/3
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/2725 using a fluid fuel gas generator
• 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

An inflator for a safety restraint system includes a gas storage vessel having a mouth, and a diffuser extending outwardly from the mouth and defining gas outlet ports. A combustion chamber having a flared open end is secured to the gas storage vessel peripherally adjacent the mouth and defines throttle orifices for releasing inflation gas from the gas storage vessel. A breakaway closure member is secured across the mouth of the gas storage vessel and the open end of the combustion chamber housing, the breakaway closure member including a periphery ring, a translating boss having an initiator mounted therethrough and a skirt slidingly received in the open end of the combustion chamber housing, and a frangible web connecting the boss to the periphery ring. The combustion chamber housing further defines exhaust ports opening to the gas storage vessel, and contains combustible material, which may be pyrotechnic gas generator or fluid fuel. The initiator ignites the combustible material and the resultant increased pressure in the combustion chamber housing fractures the frangible web and drives the translating boss into the diffuser to release gas from the gas storage vessel through the throttle orifices and diffuser. Hot products of combustion are delivered through the combustion chamber exhaust ports to heat and augment the pressure of the gas.

Claims

1. An inflator for a safety restraint system, the inflator comprising:

A) a gas storage vessel having a mouth;

B) a diffuser surrounding and extending outwardly from the mouth of the gas storage vessel and defining a plurality of gas outlet ports;

C) a combustion chamber housing having an open end secured to the gas storage vessel peripherally adjacent the mouth thereof, the combustion chamber housing defining adjacent its open end a plurality of outlet orifices for releasing inflation gas from the gas storage vessel, the combustion chamber housing further defining exhaust ports opening to the interior of the gas storage vessel;

D) a breakaway closure member sealingly secured across the mouth of the gas storage vessel to provide a closed gas storage chamber and across the open end of the combustion chamber housing to provide a combustion chamber, the breakaway closure member including

i) a periphery ring,

ii) a translating boss having an initiator mounted therethrough and a skirt slidingly received in the open end of the combustion chamber housing,

iii) a frangible web connecting the translating boss to the periphery ring, wherein, upon fracture of the web, the translating boss translates into the diffuser to open the mouth of the gas storage vessel to provide a path from the outlet orifices through the diffuser outlet openings, with the skirt of the translating boss still received in the open end of the combustion chamber housing; and

E) pressurized gas contained within the gas storage vessel and combustible material contained within the combustion chamber housing,

whereby operation of the initiator ignites the combustible material in the combustion chamber housing and the resultant increased pressure in the combustion chamber housing fractures the frangible web and drives the translating boss into the diffuser to release gas from the gas storage vessel through the outlet orifices and diffuser, and hot products of combustion of the combustion material are delivered through the combustion chamber exhaust ports to heat and augment the pressure of the gas.

2. An inflator as defined in claim 1 wherein the combustible material contained within the combustion chamber housing includes a pyrotechnic gas generant.

3. An inflator as defined in claim 2 wherein the combustible material contained within the combustion chamber housing includes ignitor material deployed adjacent the initiator.

4. An inflator as defined in claim 3 wherein the ignitor material is held deployed adjacent the initiator by a bracket and seal.

5. An initiator as defined in claim 4 wherein the pyrotechnic gas generant is secured within the combustion chamber by a perforate screen.

6. An inflator as defined in claim 5 wherein the skirt of the translating initiator boss blocks the exhaust ports of the combustion chamber housing and the exhaust ports are exposed upon translation of the translating initiator boss.

7. An inflator as defined in claim 1 wherein the skirt of the translating initiator boss blocks the exhaust ports of the combustion chamber housing and the exhaust ports are exposed upon translation of the translating initiator boss.

8. An inflator as defined in claim 7 wherein the skirt has a skirt end secured to the combustion chamber housing to seal the exhaust ports thereof.

9. An inflator as defined in claim 8 wherein the combustible material is a fluid fuel.

10. An inflator as defined in claim 9 wherein the combustion chamber is divided into two sub-chambers respectively containing the fluid fuel and an oxidizer for the fluid fuel.

11. An inflator as defined in claim 1 wherein the combustible material is a fluid fuel.

12. An inflator as defined in claim 11 wherein the combustible material is a fluid fuel and an oxidizer for the fluid fuel maintained in separate sealed portions of the combustion chamber.

13. An inflator as defined in claim 11 wherein the translating initiator boss defines a fill port for the stored gas.

14. An inflator as defined in claim 11 wherein the initiator boss defines the fill port for the fluid fuel.

15. An inflator as defined in claim 1 wherein the outlet orifices defined by a flared end of the combustion chamber housing are throttle orifices controlling the flow of inflation gasses from the gas storage chamber.

16. An inflator as defined in claim 15 wherein the diffuser outlet openings are radially disposed.

17. An inflator as defined in claim 15 wherein the diffuser receives and limits the extent of translation of the translating initiator boss.

18. An inflator as defined in claim 17 wherein the diffuser mounts a shock absorbing and sealing pad receiving the translating initiator boss.

19. An inflator as defined in claim 18 wherein the diffuser defines an opening providing access to the translating initiator boss for attaching electrical leads to the initiator mounted therethrough.

20. An inflator as defined in claim 1 wherein the diffuser receives and limits the extent of translation of the translating initiator boss.

21. An inflator as defined in claim 20 wherein the diffuser mounts a shock absorbing and sealing pad receiving the translating initiator boss.

22. An inflator as defined in claim 21 wherein the diffuser defines an opening providing access to the translating initiator boss for attaching electrical leads to the initiator mounted therethrough.

23. An inflator as defined in claim 1 wherein the translating initiator boss defines a fill port for the stored gas.

24. An inflator as defined in claim 1 wherein the combustion chamber housing has a flared open end defining the outlet orifices.

25. An inflator as defined in claim 24 wherein the outlet orifices throttle the flow of inflation gas from the gas storage vessel.

26. An inflator as defined in claim 1 wherein the gas storage vessel is elongated and extends to a closed end having mounting flange, adapting the inflator for use on the passenger side of a vehicle.

27. An inflator as defined in claim 26 wherein the gas storage vessel has a neck adjacent its mouth.