摘要 |
An occupant restraint system comprises an inflatable air bag having an open end which is closed by one side of a base plate having a central circular opening flanked by a plurality of circumferentially-spaced mounting holes. An inflator for the air bag has a cylindrical casing with radial fluid discharge ports for discharging gas. A flange extends radially beyond the casing below the discharge ports and includes four circumferentially-spaced mounting holes which mate with the base plate mounting holes. The inflator acts as a valve to maintain air bag pressure below a predetermined level. This is accomplished by providing guide pins extending through the mated mounting holes. The guide pins carry compression springs which bias the inflator to a first position in which the flange engages the base plate with the discharge ports located above the base plate in operative communication with the air bag. The inflator includes a reaction surface located above the discharge ports which is exposed to air bag pressure. When the force exerted by air bag pressure exceeds a predetermined level, the springs compress and the inflator slides on the pins to a second position in which the discharge ports are located below the base plate out of operative communication with the air bag. Alternatively, the inflator may be supported by a plastically yieldable support which collapses to allow movement of the inflator to the second position.
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