Valve assembly for a replaceable filter respirator
作者： Edward N. Montesi
DOI:
关键词:
摘要: A respirator having a disposable filter includes valve body central aperture providing concentric inhalation and exhalation valves.
lens.org 参考文章(2)
Rutherford B Snyder, Harry W Austin, John C Miller, John W Neidhart, Foldable protective head enclosure ,(1970)
Silverman Leslie, Cover for a respirator filter holder ,(1964)