| 摘要 |
A face mask comprising a head covering, a sealing means for isolating the head covering from the atmosphere when the head covering is worn, an air outlet and inlet section connected to the head covering and wiper means provided at the head covering. The air outlet and inlet section comprises a hollow joint member having upper and lower ends and an opening at a side section thereof, outer conduit means, one end being rotatably secured to a front lower portion of the head covering, and the other end being secured to the upper end of the joint member, inner conduit means connected at one end to the opening of the joint member and extending within the outer conduit up to the front lower portion of the head covering, a flexible conduit means secured at one end to the lower end of the joint member and having a free end to which filter means is connected, first valve means operatively situated in the joint member so that when the air is inhaled into the head covering, only the first valve means opens, and second valve means operatively situated at a free end of the inner conduit means so that when air is exhaled to the atmosphere, only the second valve means opens.
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