Hybrid inflator and related propellants

• US 5,623,116 A
• Filed: 01/11/1996
• Issued: 04/22/1997
• 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: Hamilton, Brian K., Baglini, James L.
• Primary Examiner(s): Nelson, Peter A.
• Application Number:
  US08/584,440
• Time in Patent Office: 467 Days
• Field of Search: 280/741, 280/742, 280/736, 102/288, 102/289, 102/290, 102/536
• US Class Current: 102/289
• 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 25/34 the compound being a nitrated acyclic, alicyclic or heterocyclic amine
• 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

Abstract

A hybrid inflator for an automotive inflatable safety system is disclosed. In one embodiment, a mixture of an inert gas (e.g., argon) and oxygen are contained within the inflator housing and a hybrid propellant (i.e., ballistic properties similar to double-base and long-term stability similar to LOVA) is included in the gas generator.

Claims

1. A method for operating an inflatable safety system comprising an air/safety bag and an inflator comprising an inflator housing, a pressurized medium contained within at least said inflator housing, a gas generator comprising a gas generator housing comprising at least one gas generator inlet, a plurality of gas generator outlets, an interior surface and an exterior surface, and a propellant contained within an interior of said gas generator housing defined by said interior surface, said method comprising the steps of:

creating a flow path between said inflator housing and said air/safety bag;

igniting and combusting said propellant within at least said interior of said gas generator housing to generate combustion products within at least said interior of said gas generator housing;

providing a flow along said exterior surface of said gas generator housing and past said plurality of said gas generator outlets after said creating a flow path step;

drawing at least a portion of said pressurized medium into said interior of gas generator through said at least one gas generator inlet using said providing a flow step; and

discharging said combustion products and said at least a portion of said pressurized medium from said gas generator housing through said plurality of gas generator outlets.

2. A method, as claimed in claim 1, wherein:

said pressurized medium comprises at least one inert gas and oxygen;

said propellant comprises a secondary explosive; and

said method further comprises the step of reacting at least a portion of said combustion products with said oxygen.

3. A method, as claimed in claim 1, wherein:

said drawing step comprises mixing said combustion products and said at least a portion of said pressurized medium at least within said inside of said gas generator housing.

4. A method, as claimed in claim 1, wherein:

a direction of said flow provided by said providing step is generally in a non-parallel relation with a central axis through said plurality of gas generator outlets.

5. A method, as claimed in claim 1, wherein:

said discharging step comprising drawing combustion products and pressurized medium out of said interior of said gas generator housing by said providing a flow step.

6. A method, as claimed in claim 1, wherein:

said providing a flow step comprises creating a pressure differential across each of said plurality of gas generator outlets to facilitate said drawing step.

7. A method, as claimed in claim 1, wherein:

said gas generator housing comprises a generally cylindrical sidewall and a first end wall, said plurality of gas generator outlets being disposed on said sidewall and each said gas generator inlet being disposed on said first end wall.

8. A method, as claimed in claim 1, wherein said propellant comprises a secondary explosive, and wherein said combusting step comprises forming combustion gases comprising carbon monoxide and hydrogen, said method further comprising the steps of:

mixing said combustion gases with said pressurized medium; and

generating heat and converting at least some of said carbon monoxide and hydrogen into carbon dioxide and water during said mixing step.

9. A method, as claimed in claim 8, wherein:

substantially all of said carbon monoxide and hydrogen are converted to carbon dioxide and water.

10. A method, as claimed in claim 8, wherein:

said combusting step comprises combusting at a temperature ranging from about 2,000°

K. to about 3,800°

K.

11. A method, as claimed in claim 8, wherein:

said secondary explosive is selected from the group consisting of RDX (hexahydrotrinitrotriazine), HMX (cyclotetramethylene tetranitramine), PETN (pentaerythritol tetranitrate), and TAGN (triaminoguanidine nitrate).

12. A method, as claimed in claim 8, wherein:

said binder system comprises an additive selected from the group consisting of plasticizers, binders, stabilizers and combinations thereof.

13. A method, as claimed in claim 1, wherein:

said providing a flow step is substantially parallel to said exterior surface of said gas generator housing.