| 摘要 |
A face mask intended to cover at least the wearer's mouth and nose includes means for holding the mask in a fixed position on the wearer, and further includes a first and a second (1) opening, an inhalation valve fitted in the first opening and connectable to a source of breathing gas, and an exhalation valve (4) fitted in the second opening (1). According to the invention, the mask includes a device (5) which is fitted on the outside of the mask and surrounds the exhalation valve (4). The exhalation valve (4) is mounted in the device (5) such that when the device (5) is in an open position (5') the exhalation valve (4) will be out of contact with the second opening (1), and so that when the device (5) is in a closed position the inhalation valve will be in contact with the second opening (1). The exhalation valve functions as a one-part valve in the closed position of the device (5). The face mask also includes locking means which function to hold the device (5) either in its open or its closed position, and indicating means which can be seen by the wearer of the mask and which indicates whether the device is open or closed. |
