Abstract: A protective fabric suitable for use in hazardous environments such as those in which nuclear, chemical and biological warfare agents or similar hazardous elements exist. In general, the protective fabric comprises a plurality of layers of air- and water-vapor-permeable, thin, stretchable fabric materials, each being treated to provide separate or combined protective functions. The protective fabric may be fashioned into articles of protective apparel suitable for applications where close-fitting and conforming garments are required and where heat-stress and bulk of material is of concern.

Abstract: A pleated paper filter is installed in a gas mask filter canister without the use of adhesives. The paper filter has an annular sealing ring around it of polyurethane. The polyurethane sealing ring has an outer downwardly tapered face that is a force fit inside the canister housing. A retainer on top of the pleated paper filter element has a peripheral flange that engages the seal above the pleated paper and restricts its inward deformation, so that the sealing force between the seal and the wall of the housing is very high.

Abstract: A method and an apparatus are provided for securing a bed of charcoal under pressure in a plastic material housing in the manufacture of charcoal filter canisters for gas masks. The bed of particulate charcoal is placed in the housing and covered with a retainer. A compactor is placed on the retainer and loaded to produce the desired compaction of the charcoal. An ultrasonic welder is then used to secure the retainer in place for one embodiment, a spring-loaded compactor is placed on top of the retainer and an ultrasonic nodal horn is placed over the compactor. The horn presses the compactor against the retainer with the necessary compressing force to compress the charcoal bed, while at the same time producing an ultrasonic weld around the periphery of the housing, welding the retainer in place. The compactor seats on a nodal point of the horn, so that ultrasonic vibrations are not transmitted from the horn through the compactor to the charcoal bed.

Abstract: An improvement to a face mask is disclosed which has two eyepieces, a pliable full face covering, breathing means and means for sealing and securing the mask to the face of a wearer. The improvement being nose occluding means which include a pair of prong members made of a rigid material. Each prong member is adjustably attached at one end thereof to a lower rim portion of a respective eyepiece at an angle with respect thereto so that it is directed inwardly toward the nose of the wearer. A method of nose occlusion in order to perform the valsalva maneuvre utilizing the improved face mask is also disclosed.