Importance

Loading Importance Indicators...

Abstract

A respirator mask includes an inner plenum with a gas inlet and a manifold adapted to fit under the nose of a wearer, a pair of nasal inserts projecting from the manifold to define primary seals with the nasal passages of the wearer, an outer plenum adapted to surround at least the nose of the wearer, a secondary seal mounted on an outer edge of the outer plenum and adapted to contact the face of the wearer around the nose in air tight relation, and at least one opening formed in the inner plenum to permit gas to flow into the outer plenum. By pressurizing the outer plenum, the mask decreases the pressure differential between the interior of the mask and the outside atmosphere to reduce the gas flow rate out of the mask in the event of a leak. Diversion of gas into the outer plenum also allows use of an inflatable secondary seal to maintain air-tight contact with the face of the user.

Loading the Abstract Image...

First Claim