Safety air bag inflation device

Abstract

An air bag inflator providing a source of gas, releasable upon command, to inflate a supplemental inflation restraint (SIR) system commonly known as an automobile air bag. Provided is a pressure vessel containing one or more separate chambers for the purpose of storing gaseous fuel(s) and gaseous oxidizer(s) or liquid fuel(s) and liquid oxidizer(s) under pressure with helium as the primary filler gas. The primary function of the helium gas is to serve as a kinetic damper to modulate and control the reaction rate of the fuel(s) and oxidizer(s). Because of its low mass, high thermal conductivity and high heat capacity for its mass, helium is an excellent filler gas. In the case of the gaseous fuel(s) and oxidizer(s) a single chamber is provided. In the case of liquid fuel(s) and oxidizer(s), two or more separate housings are provided for storing the liquid fuel(s) and oxidizer(s). Along with the liquid fuel(s) and oxidizer(s) housings, two separate chambers containing pressurized helium are provided within the pressure vessel. The first helium chamber rapidly pressurizes upon initiation of a gas producing pyrotechnic igniter. This pressure acts on thin membranes on the first chamber side of the separate liquid storage housings to force the liquid fuel(s) and oxidizer(s) into the second chamber where the materials are atomized and mixed. The mixture is ignited by the arrival of hot gases from the igniter directed into the second chamber via the small diameter tube or orifice. The fuel(s) oxidizer(s) mixture burns to produce gaseous reaction products that are released into the air bag by bursting a controlled rupture burst disc.