Air bag device for vehicles

Claim 1

For use in a vehicle having collision sensing means mounted thereon to rapidly generate a signal in response to a collision, cushioning apparatus to be mounted in said vehicle and deployed upon collision to protect an occupant in the vehicle from injury, said cushioning apparatus comprising: (a) a reservoir containing prior to collision a pressurized fluid and having an outlet, (b) an inflatable cushion having an inlet, (c) a frangible plate interposed between the outlet of said reservoir and the inlet of said inflatable cushion and preventing the passage of pressurized fluid from said reservoir to said inflatable cushion, said frangible plate having an upstream side facing the outlet of said reservoir and a downstream side opposite said upstream side, said frangible plate rapidly shattering into discrete fragments when struck, (d) first means to support said frangible plate around the periphery thereof so as to leave the major central area of said frangible plate unobstructed, (e) a striking member having a longitudinal axis, a first end to strike said frangible plate and rapidly shatter said frangible plate, a second end opposite said first end, and a transverse cross-section substantially smaller than the major central area of said frangible plate, (f) second means mounting said striking member within said reservoir adjacent the upstream side of said frangible plate for movement along said longitudinal axis toward the upstream side of said frangible plate, (g) third means within said reservoir to rapidly apply a force to the second end of said striking member in response to a signal generated by said collision sensing means to drive said striking member along said longitudinal axis toward the upstream side of said frangible plate so that the first end of said striking member shatters said frangible plate, (h) an aperture in said reservoir, (i) fourth means connected to said third means and extending through said aperture, said fourth means to be connected to said collision sensing means so that a signal generated by said collision sensing means is communicated through said fourth means to said third means, (j) fifth means hermetically sealing said aperture about said fourth means to prevent the escape of pressurized fluid from said reservoir through said aperture, (k) whereby to provide a passage generally annularly disposed about said striking member and of area adequate to permit the rapid flow therethrough of said pressurized fluid from said reservoir into said inflatable cushion in response to a signal generated by said collision sensing means and indicative of a collision, (l) filter means interposed between the downstream side of said frangible plate and the inlet of said inflatable cushion.