| 摘要 |
<p>A combined pressure compensated exhalation and anti-suffocation valve assembly of the type which may find utility in an aviator's breathing mask. The valve assembly (14) includes a valve body (20) provided with an exhaust port (44) and a compensated pressure chamber (62) in communication with the mask cavity through an orifice tube (72). Disposed within the valve body (14) are a movable diaphragm assembly (22) and an exhaust port plate (24) supported by and movable toward and away from the diaphragm assembly. There is a lost motion connection (106, 108 or 138, 140) extending between the diaphragm assembly and the exhaust port plate, the connection being capable of permitting the exhaust port plate to move relative to the diaphragm assembly within a predetermined range of movements, the parts being so arranged and constructed that if during an inspiratory effort the diaphragm assembly attempts to move away from the exhaust port plate a distance greater than that permitted by the lost motion connection means, as would be the case if the breathing gas supply fails to deliver an adequate supply of gas to the mask cavity, the diaphragm assembly acting through the lost motion connection means will cause corresponding movement of the exhaust port plate thereby opening the mask cavity to ambient.</p> |
