Liquid propellant airbag inflator with dual telescoping pistons
AssigneeGeneral Dynamics Armament Systems, Inc.
InventorAlfred Charles Maynard
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Abstract
An airbag inflator includes a pair of telescoping pistons slidingly mounted within a housing. Pressurization of a combustion chamber by a pyrotechnic initiator acts on one piston to pressurize a hydraulic fluid chamber, which, in turn, acts on the other piston to pressurize a liquid propellant reservoir. Liquid propellant can then be regeneratively pumped from the reservoir into the combustion chamber for combustion to generate an airbag inflation gas. A hydraulic fluid damping chamber is utilized to exert a controllable retarding force on the one piston, such as to control the rate of airbag inflation gas generation.
Claims25
An airbag inflator comprising:
- a housing;
- first and second pistons in telescoping relation to one another and mounted for axial sliding motion within the housing;
- a combustion chamber within the housing;
- a reservoir within the housing containing a liquid propellant;
- an injection orifice, through which the liquid propellant may flow from the reservoir into the combustion chamber;
- a coupling chamber within the housing containing a hydraulic fluid exposed to the first and second pistons;
- and
- a pyrotechnic initiator within the housing operable to pressurize the combustion chamber, the combustion chamber pressure exerting a force tending to drive the first piston in a first axial direction to pressurize the coupling chamber hydraulic fluid, and the pressurized coupling chamber hydraulic fluid exerting a force tending to drive the second piston in a second axial direction opposite the first axial direction to pressurize the liquid propellant in the reservoir, the liquid propellant pressure exceeding the combustion chamber pressure, such that the liquid propellant may be regeneratively pumped through the injection orifice into the combustion chamber for combustion to produce airbag inflation gas.
Dependencies are inferred from the claim text.