| 摘要 |
The present invention relates to an exhalation and/or inhalation valve device for protective masks, consisting of a valve seat (1) with a valve membrane (11) of compression-moulded rubber cooperating with the valve seat. The membrane (11) is secured to the valve seat (1) close to its edge and opens initially at the edge portion of the member located opposite the attachment, thus resulting in low opening resistance, directional influence on the air flowing through and reduced suppression and distortion of speech. |
