Inflator for vehicle air bags

An inflator for a vehicular air bag, comprising:

• a casing having an inside wall forming an inner chamber for storage of gas under pressure, said casing having an exit port from said inner chamber;
• a burst disk closing said exit port;
• an exit tube in said chamber, attached to said inner wall and surrounding said exit port, said exit tube having a central axis and a cylindrical axial flow passage extending into said chamber away from said exit port, said exit tube having an entry port spaced from said exit port by a length of said exit tube, said entry port entering through the wall of said tube, the end of said tube in said chamber being closed;
• a fuel cell having a wall forming an internal cylinder, said wall being attached to said casing;
• an end cap attached to said wall, closing said cylinder at one of its ends;
• a piston slidably fitted in said cylinder, said piston having a driving face and an opposite second face, said cylinder, end cap and second face forming a fuel chamber for storage of a liquid fuel, said piston having a sidewall of a given length;
• an igniter mounted in said casing wall, said igniter including gas generating means, and opening into said fuel cell in fluid communication with said driving face of said piston;
• an igniter channel passing through the cylinder wall, disposed to be open to the gases from the igniter after it is initiated, said igniter channel being directed into said gas chamber at a combustion region alongside the cylinder, said combustion region being spaced from said entry port adjacent said igniter, on the opposite side of the end cap from the exit tube;
• an injector tube entering said fuel chamber through said end cap, and extending to said combustion region, whereby to convey fuel expelled by the piston from said fuel chamber to said region, said injector tube including injector ports near said region;
• a liquid fuel in said fuel cell;
• an oxidizer gas in said gas chamber, said gas comprising oxygen under pressure;
• and
• separation means separating said fuel from said oxidizer gas until after said igniter has been initiated.