Abstract: A respirator speech transmitter and exhalation valve module comprising a resilient exhalation valve having a low airflow resistance for exhalation but providing a secure seal against inadvertent inhalation through the exhalation valve module. An exhalation airflow channel is formed between a module body on the outside of the channel and a conical airflow guide and the exhalation valve on the inside of the channel. The exhalation airflow channel is in the form of an amplification horn. The airflow channel produces a smooth airflow for unrestricted exhalation and high intelligibility of a user's speech. The module includes a drinking conduit for selectively fluidly connecting a mouthpiece in the respirator to a beverage container and further includes an electrical communication block with internal and external fittings for connecting a microphone in the mask to a radio or amplifier carried by the mask user.

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 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 respirator speech transmitter and exhalation valve module comprising a resilient exhalation valve having a low airflow resistance for exhalation but providing a secure seal against inadvertent inhalation through the exhalation valve module. An exhalation airflow channel is formed between a module body on the outside of the channel and a conical airflow guide and the exhalation valve on the inside of the channel. The exhalation airflow channel is in the form of an amplification horn. The airflow channel produces a smooth airflow for unrestricted exhalation and high intelligibility of a user's speech. The module includes a drinking conduit for selectively fluidly connecting a mouthpiece in the respirator to a beverage container and further includes an electrical communication block with internal and external fittings for connecting a microphone in the mask to a radio or amplifier carried by the mask user.

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.