Respirator with non distorting housing - has distorting partition wall controlling gas supply and exhalation port

摘要

The respirator comprises a non-distorting housing divided by partitions into inhalation and exhalation chambers and an intermediate chamber. The partition between the inhalation and intermediate chambers distorts, while that between the latter and the exhalation chamber does not. The distorting partition actuates the control for delivery of a gaseous mixture under pressure into the inhalation chamber, and also temporarily shuts off a port in the non-distorting partition connecting the intermediate and exhalation chambers while the gas is being delivered. A pipe leads from the inhalation chamber to a face mask, while a second one runs from a second port in the non-distorting partition to the mask and contains a non-return valve. The valve allows exhaled gas to flow to the intermediate chamber and shuts automatically on inhalation, while a third port connects the exhalation chamber to atmosphere.