Hybrid inflator and related propellants

• US 5,616,883 A
• Filed: 10/25/1994
• Issued: 04/01/1997
• 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:
  US08/328,657
• Time in Patent Office: 889 Days
• Field of Search: 102/288, 102/289, 102/370
• US Class Current: 102/288
• 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. An inflator for an inflatable safety system, comprising:

an inflator housing;

a pressurized medium contained within at least said inflator housing, wherein said pressurized medium consists essentially of at least one inert gas and oxygen and wherein said pressurized medium is the only pressurized fluid contained within said inflator prior to any activation of said inflator;

a gas generator interconnected with said inflator housing and comprising a gas generator housing and at least one gas generator outlet;

a propellant contained within said gas generator housing comprising a secondary explosive and a binder system, wherein said propellant has a burn rate ranging from about 0.1 inches per second (0.25 cm/sec) to about 1 inch per second (5.0 cm/sec) at 4,000 psi (27.6 MPa), a combustion temperature ranging from about 2,000°

K. to about 3,800°

K., and has lone-term thermal stability, said secondary explosive being selected from the group consisting of RDX (hexahydrotrinitrotriazine), HMX (cyclotetramethylenetetra-nitramine) , PETN (pentaerythritol tetranitrate) , and TACN (triaminoguanidine nitrate), said binder system being selected from the group consisting of polymeric binders, plasticizers, stabilizers and combinations thereof, said binder system comprising at least one of an energetic glycidyl azide polymer, a nitrate ester plasticizer, a glycidyl azide plasticizer, nitroglycerin, and BDNPA/F (bis (2,2-dinitropropyl) acetal/formal); and

an inflator activation assembly comprising an ignitable material other than said propellant, wherein said pressurized medium is released from said inflator housing and said propellant is ingnited upon initiating said inflator activation assembly.

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

said at least one inert gas is argon.

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

said pressurized medium, on a molar basis, is about 70% to about 90% of said at least one inert gas and from about 10% to about 30% of said oxygen.

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

said pressurized medium, on a molar basis, is about 85% of said at least one inert gas and about 15% of said oxygen.

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

propellant gases from combustion of said propellant and said pressurized medium are mixed to define an output gas, said output gas containing, on a molar basis, no more than about 25% oxygen.

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

said secondary explosive comprises from about 50 wt % to about 90 wt % of said propellant and said binder system comprises from about 10 wt % to about 50 wt % of said propellant.

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

said secondary explosive comprises from about 60 wt % to about 80 wt % of said propellant and said binder system comprises from about 20 wt % to about 40 wt % of said propellant.

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

said secondary explosive comprises from about 70 wt % to about 80 wt % of said propellant and said binder system comprises from about 20 wt % to about 30 wt % of said propellant.

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

said secondary explosive comprises RDX (hexahydrotrinitrotriazine) and wherein said binder system comprises cellulose acetate, TMETN (trimethylolethane trinitrate) and ethyl centralite.

10. An inflator, as claimed in claim 9, comprising:

at least about 70 wt % of said RDX (hexahydrotrinitrotriazine), from about 5 wt % to about 15 wt % of said cellulose acetate, from about 5 wt % to about 15 wt % of said TMETN (trimethylolethane trinitrate), and no more than about 2 wt % of said ethyl centralite.

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

said secondary explosive comprises RDX (hexahydrotrinitrotriazine) and said binder system comprises GAP (glycidyl azide polymer) and a plasticizer.

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

said secondary explosive comprises RDX (hexahydrotrinitrotriazine) and said binder system comprises cellulose acetate and GAP (glycidyl azide polymer) and a plasticizer.

13. An inflator, as claimed in claim 12, comprising:

at least about 70 wt % of said RDX (hexahydrotrinitrotriazine), from about 5 wt % to about 15 wt % of said cellulose acetate, and from about 5 wt % to about 15 wt % of said GAP (glycidyl azide polymer), and from about 5 wt % to about 15 wt % of a plasticizer selected from the group consisting of ATEC (acetyl triethyl citrate) and GAP plasticizer.

18. An inflator, as claimed in claim 12, comprising:

at least about 70 wt % of said RDX (hexahydrotrinitrotriazine), from about 5 wt % to about 15 wt % of said cellulose acetate, and from about 5 wt % to about 15 wt % of said GAP (glycidyl azide polymer), and from about 5 wt % to about 15 wt % of a plasticizer selected from the group consisting of ATEC (acetyl triethyl citrate) and GAP plasticizer.

14. An inflator for an automotive inflatable safety system, comprising:

an inflator housing;

a pressurized medium contained within said inflator housing;

a gas generator interconnected with said inflator housing and comprising a gas generator housing and at least one gas generator outlet;

a propellant contained within said gas generator housing, said propellant comprising a secondary explosive and a binder system, wherein said secondary explosive comprises RDX (hexahydrotrinitrotriazine) and wherein said binder system comprises cellulose acetate, TMETN (trimethylolethane trinitrate) and ethyl centralite; and

an inflator activation assembly, wherein said pressurized medium is released from said inflator housing and said propellant is ignited upon initiating said inflator activation assembly.

15. An inflator, as claimed in claim 14, comprising:

at least about 70 wt % of said RDX (hexahydrotrinitrotriazine), from about 5 wt % to about 15 wt % of said cellulose acetate, from about 5 wt % to about 15 wt % of said TMETN (trimethylolethane trinitrate), and no more than about 2 wt % of said ethyl centralite.

16. An inflator for an automotive inflatable safety system, comprising:

an inflator housing;

a pressurized medium contained within said inflator housing;

a gas generator interconnected with said inflator housing and comprising a gas generator housing and at least one gas generator outlet;

a propellant contained within said gas generator housing, said propellant comprising a secondary explosive and a binder system, wherein said secondary explosive comprises RDX (hexahydrotrinitrotriazine) and said binder system comprises GAP (glycidyl azide polymer) and a plasticizer; and

an inflator activation assembly, wherein said pressurized medium is released from said inflator housing and said propellant is ignited upon initiating said inflator activation assembly.

17. An inflator for an automotive inflatable safety system, comprising:

an inflator housing;

a pressurized medium contained within said inflator housing;

a gas generator interconnected with said inflator housing and comprising a gas generator housing and at least one gas generator outlet;

a propellant contained within said gas generator housing, said propellant comprising a secondary explosive and a binder system, wherein said secondary explosive comprises RDX (hexahydrotrinitrotriazine) and said binder system comprises cellulose acetate and GAP (glycidyl azide polymer) and a plasticizer; and

an inflator activation assembly, wherein said pressurized medium is released from said inflator housing and said propellant is ignited upon initiating said inflator activation assembly.