| 摘要 |
A portable breathing apparatus comprising a face mask ( 1 ) having a breathing valve ( 2 ), a blower ( 4 ) for the supply of breathing air to the breathing valve via a supply line ( 3 ), a filter device ( 7, 8 ) for cleaning of the breathing air from the blower ( 4 ), and a compressed-air container ( 12 ) for alternative supply of breathing air to the breathing valve. The breathing apparatus is characterised in that the breathing valve ( 2 ) is a demand valve, that a check valve ( 9 ) is arranged on the upstream side of the blower ( 4 ), and that the compressed-air container ( 12 ) is provided with a pressure control valve ( 13 ) for establishing an overpressure in the entire breathing system upstream of the breathing valve ( 2 ) and downstream of the check valve ( 9 ), so that gas or liquid from the surroundings can not penetrate into the system. |
