| 摘要 |
<p>An exhalation valve assembly for a respirator, said assembly comprising an upstream one-way flap valve (1) and a downstream one-way flap valve (2), both mounted within a housing (3,4,5). The valves (1,2) are 5 spaced apart to define therebetween a volume (25) which acts as a "dead space" in which a portion of the just-exhaled air will rest so that, should the upstream valve leak for any reason, any leakage air drawn back into the respirator will be taken from this just-exhaled air, and will thus not be contaminated by the ambient air.</p> |
