Two-stage air bag system

Claim 1

A two-stage air bag system for a vehicle comprising: a housing having one open end, said housing further being divided into two chambers which are adjacent to each other; a first pressure device comprising a solid gas producing material provided in one of the two chambers; a second pressure device comprising a solid gas producing material provided in another one of the two chambers; a first ignition means for igniting said solid material at the first pressure device, said means causing ignition when an emergency condition occurs; a filter means provided on said housing enclosing said open ends; an air bag coupled to said housing about said open ends; a delayed ignition signal generator being provided in said solid gas producing material of said first pressure device in one of said chambers, said delay ignition signal generator comprising a switch means that turns on when a pressure generated by said gas producing material of said first pressure device applied to said switch means exceeds a predetermined value, said switch means comprising: a case, a movable contact slidably disposed in said case, a fixed contact provided in said case, and a spring means for biasing said movable contact away from said fixed contact; and a second ignition means responsive to said delayed ignition signal generator for igniting said solid material of said second pressure device.