Patent ID: 7806435

Claim:
A gas generator, comprising: a housing composed of a peripheral wall portion having a gas discharge port, a top plate, and a bottom plate, the top plate and the bottom plate bulging outwardly upon activation of the gas generator; a collar directly attached to the bottom plate; ignition means supported by the collar and accommodated inside the housing; a tubular member including an upper end and a lower end and provided concentrically with respect to and within the housing such that the lower end is in engagement with the collar and the tubular member defines, in an inner side and an outer side thereof, a first combustion chamber, accommodating a first gas generating agent, and a second combustion chamber, accommodating a second gas generating agent, respectively, the tubular member being provided with a reduced-diameter portion forming a step in the upper end, and a main portion having a diameter larger than the reduced-diameter portion, a plurality of communication holes for communicating the first combustion chamber with the second combustion chamber being provided only in the main portion; an annular plane extending in a radial direction of the housing from the upper end of the tubular member and including, in an inner side thereof, a bent portion, and being provided such that the bent portion abuts against the step; and an annular filter disposed so as to surround the tubular member, wherein the housing is provided with an upper annular inclined surface formed between the peripheral wall portion and the top plate, and a lower annular inclined surface formed between the peripheral wall portion and the bottom plate, a first angle of the upper annular inclined surface with respect to an imaginary line extending perpendicular to an axial direction of the housing and a second angle of the lower annular inclined surface with respect to the imaginary line do not substantially change before and after the activation of the gas generator, and the annular filter is disposed such that an upper end surface and a lower end surface thereof abut against the upper annular inclined surface and the lower annular inclined surface, respectively, and a gap is provided between an outer peripheral surface of the annular filter and the peripheral wall portion of the housing.