Abstract: A breathing mask (1) with overpressure in the mask interior space (26) with a demand oxygen system (8) at a connection piece (32) of the breathing mask, with a switching member (11) at the demand oxygen system for generating the overpressure, and with an actuating element (23) acting on the switching member at the connection piece for switching on the overpressure. Switchover to overpressure operation is possible only when the breathing mask has been put on by providing an actuating element (23) led out of the connection piece (32) at a boundary area (6) between the breathing mask (1) and the face of a mask user (4) such that it is brought into the switched-on position when the breathing mask is put on by interaction with a portion of the surface of the face of the mask user (4).

Abstract: A valve with pressure compensation via two valve bodies (9, 10), which are arranged on a connecting rod (11 ) in the same direction, and which come to lie on the corresponding valve seats (7, 8) in the closed position in the same direction via deforming zones. The tightness between the valve bodies and the corresponding valve seats is increased, and the closing force required for sealing is reduced by deforming zones located between the upper valve body (9) and the upper valve seat (7), as well as between the lower valve body (10) and the lower valve seat (8) which are designed as pressure pieces (14, 16) yielding differently to the closing force.

Abstract: A pressure gas operated pump, comprises, a housing which has two spaced apart double pump chambers, with diaphragms stretched across each pump chamber so as to define a driving fluid chamber and a pump fluid chamber and a rigid coupling interconnects the diaphragms. There are valve inlet and outlet passages connected into the respective pump fluid chambers for handling the pump fluid during the movement of the diaphragm. A control valve is mounted in a control valve chamber, and it is connected to the fixed coupling by means of a bar spring which has its center portion fulcrummed on a contact with the wall of a bore through a transverse thin member of the housing. The driving gas is directed onto the valve chamber and it flows through the center of the valve member and, depending upon the position of the valve, which is regulated by the diaphragm, it will flow into respective ones of the two driving fluid chambers.