Abstract: The present invention is a filter cartridge with integrated inhalation and exhalation valves. The exhalation valve integrated into the filter cartridge prevents unfiltered air from being inhaled. The inhalation valve(s), also integrated into the filter cartridge, effectively reduces the dead space inside the filter cartridge and thereby limits re-breathing of carbon dioxide.

Abstract: The present invention is a protective hooded respirator optimized for both high protection against nuclear, chemical and/or biological agents as well as having a design configuration enabling it to be stored as a highly compact unit. The hood includes a flexible oral-nasal breathing interface interior to the hood. A filter-housing exterior to the hood is fluidly coupled by a single conduit that intakes filtered air during inhalation and exhaled air during exhalation. When in storage, the flexible oral-nasal is folded into a substantially flat configuration.

Abstract: A face mask for filtering airborne particles formed by an upper portion adapted for placement over a user's nasal area and a lower portion adapted for placement over a user's oral area. Ribs are formed ultrasonically extending along the length of the upper portion, and a pair of ears are formed at either end having openings therethrough to receive a plastic strap for passing through the openings of the ears to secure the mask to a user's face. The mask is formed by layers of plastic material including scrim and filtration material forming the upper and lower portions that have been ultrasonically bonded together. A process for making the mask includes providing plastic fabric layered materials that are ultrasonically welded with a plurality of ribs and slitting and sealing them to form two portions. The two portions are fed in overlying sandwiched relationship to each other and scored for the ears while at the same time welding them together to form an upper and lower portion of the mask.

Abstract: A self-contained, closed circuit breathing apparatus having a balanced breathing resistance system is provided by an apparatus comprising an inhalation conduit and an exhalation conduit, a mouth connection communicating with said conduits for making connection with the mouth of the operator, an inhalation check valve and an exhalation check valve on either side of said mouth connection providing uni-directional flow through said inhalation and exhalation conduits, respectively, a chemical canister connected across said inhalation and exhalation conduits, a pre-canister storage container communicating with said exhalation conduit, said pre-canister storage container being provided with a uni-directional impedance component comprised of a resistance means for allowing one part of the exhaled air during exhalation to pass into the pre-canister storage container and the remainder to pass through said chemical canister into a post-canister storage container and a uni-directional check valve permitting essentially