| 摘要 |
A rebreather mouthpiece 1 with a closed circuit mode comprises an inhale direction valve 6, an exhale direction valve 7, an automatic diluent valve 11, an overpressure valve 8, 9 and 18 and a switching barrel 4 which is operable by the user to switch the mouthpiece between the two modes of operation. In the closed circuit mode a user is enabled to inhale breathing gas via the inhale direction valve and to exhale breathing gas via the exhale direction valve and the overpressure valve opens beyond a first threshold pressure and the automatic diluent valve provides a diluents gas beyond a second threshold pressure. In the open circuit mode a user inhales breathing gas via the automatic diluent valve and exhales breathing gas via the overpressure valve. The overpressure valve is deactivated or the absolute value of the first threshold pressure is reduced in the open circuit switch state and the automatic diluent valve provides a diluent gas beyond a third threshold pressure having a smaller absolute value than the second threshold pressure. |
