Hybrid inflator with pop-out diffuser

• US 5,670,738 A
• Filed: 08/08/1996
• Issued: 09/23/1997
• Est. Priority Date: 08/08/1996
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Olson, Brent K., Storey, J. Kirk
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/694,202
• Time in Patent Office: 411 Days
• Field of Search: 102/530, 102/531, 137/68.21, 222/3, 239/204, 280/736, 280/737, 280/740, 280/741, 280/742, 422/164
• US Class Current: 102/530
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• 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: 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

Abstract

A hybrid inflator including an inflator housing having an outer wall and a pop-out diffuser. The outer wall defines a compressed gas reservoir and contains a combustion chamber separated from the compressed gas reservoir by a rupturable burst diaphragm. An initiator and pyrotechnic gas generant are contained within the combustion chamber of the inflator housing. The initiator is connectable to a remote collision or deceleration sensor through an initiator port defined by the outer wall. Compressed inert gas is contained within the compressed gas reservoir. The pop-out diffuser includes a diffuser plate forming a unitary part of the outer wall and a rupturable seam divides the diffuser plate from the remainder of the outer wall. A diffuser sleeve extends from the diffuser plate into the compressed gas reservoir to a diffuser flange extending radially outwardly from the diffuser sleeve and having an outer diameter that is greater than an outer diameter of the diffuser plate. The diffuser sleeve defines a plurality of gas exhaust ports. Upon initiation of the inflator, the initiator ignites the pyrotechnic gas generant which burst through the rupturable burst diaphragm to heat the compressed inert gas. The heated compressed inert gas pressurizes and causes the rupturable seam of the diffuser plate to rupture and form a portal so that the pop-out diffuser will extends out of the outer wall through the portal. The compressed inert gas can then exit the inflator through the gas exhaust ports of the diffuser sleeve and be dispersed for inflating an inflatable airbag cushion.

Claims

1. An inflator housing for use as part of a hybrid inflator, the housing comprising:

A) an outer wall defining a compressed gas reservoir;

B) a pop-out diffuser including;

1) a diffuser plate forming a unitary part of the outer wall,

2) a rupturable seam dividing the diffuser plate from the outer wall, and

3) a diffuser sleeve extending from the diffuser plate into the compressed gas reservoir to a diffuser flange extending radially outwardly from the diffuser sleeve, the diffuser flange having an outer diameter greater than an outer diameter of the diffuser plate, the diffuser sleeve defining a plurality of gas exhaust ports.

2. An inflator housing as defined in claim 1 wherein the outer wall comprises:

1) an elongated, generally cylindrical sidewall extending from a first end to a second end;

2) a first endwall closing the first end of the cylindrical sidewall and defining an initiator port, a combustion housing extending from the first endwall to within the cylindrical sidewall, the combustion housing internally defining a combustion chamber extending from the initiator port and communicating with the compressed gas reservoir through an inlet port defined by the combustion housing, a rupturable burst diaphragm sealing the inlet port; and

3) a second endwall closing the second end of the cylindrical sidewall, the diffuser plate of the pop-out diffuser forming part of the second endwall with the diffuser sleeve extending to within the cylindrical sidewall.

3. An inflator housing as defined in claim 2 wherein a portion of the second endwall extends radially outwardly from the cylindrical sidewall of the inflator housing and defines a plurality of spaced-apart mounting holes.

4. An inflator housing as defined in claim 1 further comprising a generally cylindrical center tie having an upper end and a lower end, the center tie defining a combustion chamber extending axially inwardly from the lower end, and a diffuser cavity extending axially inwardly from the upper end, and wherein the outer wall includes:

1) an upwardly facing concave bottom wall secured to the lower end of the central tie and defining an initiator port providing access to the combustion chamber;

2) a downwardly facing concave top wall secured to the upper end of the central tie, with an outer edge of the top wall secured to an outer edge of the bottom wall so that the center tie, the top wall and the bottom wall define the compressed gas reservoir, the diffuser plate of the pop-out diffuser forming part of the top wall covering the diffuser cavity, with the diffuser sleeve extending into the diffuser cavity; and

3) the center tie defining an inlet port connecting the combustion chamber with the compressed gas reservoir and an outlet port connecting the compressed gas reservoir with the diffuser cavity, with a rupturable burst diaphragm sealing the inlet port.

5. An inflator housing as defined in claim 4 wherein the outlet port is substantially diametrically opposed to the inlet port defined by the center tie.

6. An inflator housing as defined in claim 4 further comprising an inflator flange extending radially outwardly from the outer edge of the top wall and defining a plurality of spaced-apart mounting holes.

7. An inflator housing as defined in claim 1 wherein the diffuser sleeve of the pop-out diffuser contains filter material.

8. An inflator housing as defined in claim 1 wherein the diffuser flange is continuous.

9. A hybrid inflator comprising:

A) an inflator housing including

1) an outer wall defining a compressed gas reservoir and containing a combustion chamber separated from the compressed gas reservoir by a rupturable burst diaphragm, the outer wall defining an initiator port providing access to the combustion chamber, and

2) a pop-out diffuser including;

a) a diffuser plate forming a unitary part of the outer wall,

b) a rupturable seam dividing the diffuser plate from the remainder of the outer wall, and

c) a diffuser sleeve extending from the diffuser plate into the compressed gas reservoir to a diffuser flange extending radially outwardly from the diffuser sleeve, the diffuser flange having an outer diameter greater than an outer diameter of the diffuser plate, the diffuser sleeve defining a plurality of gas exhaust ports;

B) compressed inert gas contained within the compressed gas reservoir of the inflator housing; and

C) an initiator and pyrotechnic gas generant contained within the combustion chamber of the inflator housing, the initiator operable by a remote collision sensor through the initiator port defined by the outer wall.

10. A hybrid inflator as defined in claim 9 wherein the outer wall of the inflator housing comprises:

1) an elongated, generally cylindrical sidewall extending from a first end to a second end;

2) a first endwall closing the first end of the cylindrical sidewall and defining the initiator port, a combustion housing extending from the first endwall to within the cylindrical sidewall, the combustion housing internally defining the combustion chamber extending from the initiator port and communicating with the compressed gas reservoir through an inlet port defined by the combustion housing, the rupturable burst diaphragm sealing the inlet port; and

3) a second endwall closing the second end of the cylindrical sidewall, the diffuser plate of the pop-out diffuser forming part of the second endwall with the diffuser sleeve extending to within the cylindrical sidewall.

11. A hybrid inflator as defined in claim 10 wherein a portion of the second endwall of the inflator housing extends radially outwardly from the cylindrical sidewall of the inflator housing and defines a plurality of spaced-apart mounting holes.

12. A hybrid inflator as defined in claim 9 further comprising a generally cylindrical center tie having an upper end and a lower end, the center tie defining the combustion chamber extending axially inwardly from the lower end, and a diffuser cavity extending axially inwardly from the upper end, and wherein the outer wall includes:

1) an upwardly facing concave bottom wall secured to the lower end of the central tie and defining the initiator port,

2) a downwardly facing concave top wall secured to the upper end of the central tie, with an outer edge of the top wall secured to an outer edge of the bottom wall so that the center tie, the top wall and the bottom wall define the compressed gas reservoir, the diffuser plate of the pop-out diffuser forming part of the top wall covering the diffuser cavity, with the diffuser sleeve extending into the diffuser cavity; and

3) the center tie defining an inlet port connecting the combustion chamber with the compressed gas reservoir and an outlet port connecting the compressed gas reservoir with the diffuser cavity, with the rupturable burst diaphragm sealing the inlet port.

13. A hybrid inflator as defined in claim 12 wherein the outlet port is generally diametrically opposed to the inlet port defined by the center tie of the inflator housing.

14. A hybrid inflator as defined in claim 12 wherein the inflator housing further comprises an inflator flange extending radially outwardly from the outer edge of the top wall and defining a plurality of spaced-apart mounting holes.

15. A hybrid inflator as defined in claim 9 wherein the diffuser sleeve of the pop-out diffuser contains filter material.

16. A hybrid inflator as defined in claim 9 wherein the diffuser flange is continuous.