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 breathing mask with a fixed, curved mask body and with a mask edge extending around the mask body and adapted to the shape of the face for attaching a sealing edge sealing the mask body against the face and with a supply opening located in the mouth area of the mask body. The mask body provides low-distortion vision along with the largest possible useful field of vision. To accomplish this task, the curvature in azimuthal section planes (5, 6, 7) of the mask body (1) is designed to decrease continuously in the corresponding section plane toward the mask edge (2), starting from a meridian symmetry axis (4) of the mask body; that the azimuthal curvature on the meridian symmetry axis (4) also decreases monotonically, starting from the mouth area (8); and that the meridian curvature of the mask body 1 along the symmetry axis (4) is essentially uniform.

Abstract: A breathing mask (1) with a chamber housing fastened in the mask body (2) for accommodating at least one breathing connection (4), an exhalation valve (6), and a speaking diaphragm are improved such that the chamber housing can be replaced in a simple manner. The circumferential surface of the chamber housing is provided with a plug-type connection piece (35), the mask body (2) has a support with a shape corresponding to the plug-type connection piece (35), and the plug-type connection piece (35) and the support are detachably connected via a locking member (40).

Abstract: The invention is directed to a metering device for lung-demand valves and includes prepressure compensation. The metering device includes a valve body coacting with a valve seat for metering gas and a compensating piston is arranged between a primary pressure chamber and a secondary pressure chamber for transmitting the compensating force to the valve body. The compensating piston is guided in a compensating housing. The metering device is improved in that the compensating piston is movable without friction and a seal is easily secured. For this purpose, a membrane made of elastic material defines the seal unit. The membrane is tightly held and has a cylindrical side wall which is fixed in the compensating housing. The membrane has regions of reduced wall thickness on the periphery of the side wall and these regions are subdivided into segments or extend as one continuous portion around the periphery. The regions of reduced wall thickness act as a sealing lip.