Abstract: A filter for a gas mask has a concave outlet wall and a convex inlet wall with a particulate filter bed that has a uniform depth and conforms substantially to the shape of the inlet and outlet wall. The side wall can have an elliptical, circular or convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter an be a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A filter for a gas mask has a concave outlet wall and a convex inlet wall with a particulate filter bed that has a uniform depth and conforms substantially to the shape of the inlet and outlet wall. The side wall can have an elliptical, circular or convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter an be a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A filter for a gas mask has an elliptical or circular, convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter comprises a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A filter canister assembly for a gas mask comprising a primary canister with a first filter medium adapted to remove aerosols, particulate materials and droplets from air and a second filter medium comprising an adsorbent filter medium adapted to remove toxic gases and arranged in serial communication with the first filter medium in the first canister. A supplementary filter canister has a third filter media adapted to intercept toxic industrial materials and is removably mounted to a first end of the first housing to supplement the ability of the primary filter canister to filter toxic industrial gases.

Abstract: A gas mask having a filter canister mount including an inhalation valve and a self-sealing mechanism that prevents air inflow when a filter canister is removed from the canister mount. In one embodiment, the self-sealing valve includes an elastomeric diaphragm mounted in the inlet port and includes a hinge and a skirt, the skirt having a sealing surface that is biased into contact with a valve seat. The filter canister includes a projection adapted to act on the hinge to pivot the skirt away from the sealing surface as the canister is fitted to the canister mount. In one embodiment, the canister comprises a stacked-radial-flow arrangement of particulate and carbon filtration media. In one embodiment, the gas mask includes a visor having a pair of spaced optical panels with a hinge mounted therebetween for relative rotational movement.

Abstract: A gas mask having a filter canister mount including an inhalation valve and a self-sealing mechanism that prevents air inflow when a filter canister is removed from the canister mount. In one embodiment, the self-sealing valve includes an elastomeric diaphragm mounted in the inlet port and includes a hinge and a skirt, the skirt having a sealing surface that is biased into contact with a valve seat. The filter canister includes a projection adapted to act on the hinge to pivot the skirt away from the sealing surface as the canister is fitted to the canister mount. In one embodiment, the canister comprises a stacked-radial-flow arrangement of particulate and carbon filtration media. In one embodiment, the gas mask includes a visor having a pair of spaced optical panels with a hinge mounted therebetween for relative rotational movement.

Abstract: A filter canister assembly utilizes a sealant deflector to seal a particulate filter to the canister wall, even after the canister is sealed. The canister housing has a wall and an aperture with a particulate filter disposed therein. The particulate filter has an edge adjacent the wall, and is designed for removing particles of contaminants from a fluid, such as air, passed through the canister. A sealant deflector includes a plurality of vanes standing proud of a support substrate, and is situated between the aperture and the particulate filter and forms a permanent part of the canister assembly. The sealant deflector deflects a sealant in liquid state toward the wall to form a seal between the edge and the wall when the sealant is deposited on the sealant deflector while spinning. This deposits a sealant ring sealing the wall to the edge.