Patent ID: 6860267

Claim:
A gas mask assembly comprising: a facepiece defining an interior chamber for filtered air and including at least one inhalation opening for passage of filtered air from the atmosphere to the interior chamber, and a valve seat formed around an exterior surface of the inhalation opening; an elastomeric diaphragm forming a self-sealing valve and mounted in the at least one inhalation opening, the diaphragm having a skirt with a sealing surface that is biased against the valve seat in a sealing position to seal the at least one inhalation opening and prevent inhalation of air therethrough and the skirt is movable to an open position for passage of air through the at least one inhalation opening; a filtration canister removably mounted to the facepiece and in fluid communication with the at least one inhalation opening for passage of purified atmospheric air to the facepiece interior chamber when the self-sealing valve is opened, the filtration canister including a valve actuator for opening the self-sealing valve when the filtration canister is mounted to the facepiece; the improvement which comprises: the elastomeric diaphragm sealing surface is moveable between the sealing position and the open position when another portion of the elastomeric diaphragm is axially displaced toward the at least one inhalation opening, and the filtration canister valve actuator is mounted for movement of the diaphragm other portion toward the at least one inhalation opening when the filtration canister is mounted to the facepiece to thereby open the at least one inhalation opening for inhalation of air therethrough.