| 摘要 |
The respiratory protective device (20, 20''') minimizes dead space by locating the exhalation valve mechanism (74, 74') slightly spaced from, but directly in front of the mouth. The inhalation valve mechanism (68, 68') surrounds the streamlined flow path leading to the exhalation valve mechanism (74, 74'). The inhalation valve mechanism (68, 68') is located in a common chamber (66) which receives filtered air from all filter assemblies (22). A chin support (190) is provided which relieves any force to the gums and teeth as a result of the mouthpiece (26). Alternatively, a mechanism (228'', 228''', 228'''') for forcing the wearer's lips closed around the mouthpiece (26'', 26''', 26'''') to maintain a seal thereto is provided. |
