| 摘要 |
<p>The invention relates to a protective device, which comprises a mask part (1) that covers the user's mouth and nose and that is provided with an opening at which there is arranged a valve means (2) that allows airflow in the mask part only from inside out to convey exhaled air outside of the mask part (1). The valve means (2) is formed of a plate-like element (3) that is made of flexible material, covers the opening and is connected to the outer surface of the mask part (1). The plate-like element (3) is provided with through cuts (4) that are arranged to provide, by the effect of exhalation flow, flap parts (5) that turn outwardly from the mask part (1). The flap parts (5) are arranged to return, after exhalation, back to a position in which the flap parts (5) press in a sealable manner against one another at the cuts (4).</p> |
