Inflator

A cylindrical inflator comprises:

• an elongated tubular housing having a first end sealed by an igniter assembly and an opposite second end sealed by a diffuser assembly, the diffuser assembly having a first set of discharge openings sealed by frangible foil, and a combustion chamber interposed and extending between the igniter assembly and the foil sealed diffuser assembly;
• a hollow tubular filter positioned inside the combustion chamber having an enlarged first end compressed against an inner wall of the elongated tubular housing and an elongated narrow portion extending from the enlarged first end of the hollow tubular filter toward the second end of the tubular housing having an end attached to or abutting an internal end of the diffuser assembly, the elongated narrow portion being spaced from the elongated tubular housing to form a gas discharge plenum;
• a plurality of gas generant pellets at least partially filling the combustion chamber;
• and
• wherein upon ignition, the gas generant pellets generate inflation gases under pressure to enter and pass through the narrow portion of the hollow tubular filter filling the gas discharge plenum and bursting the foil opening the discharge openings and passing out the diffuser.