Abstract: A closed-cycle breathing equipment and gas mask for operation under pressure with a pressurized air source for respiratory air and with an air bag being under prestress during the inspiration phase includes an arrangement where the prestress is decreased by a control element recognizing the expiratory phase and so as to support respiration during the expiration phase. A pneumatic control valve is used which can switch connections between the inspiration and the expiration phase and which is directly controlled by the difference between the exhalation pressure and the pressure in the air bag. The control valve connects the pressurized air source with the air bag during the inspiration phase and during the expiration phase it interrupts the connection due to the occurring dynamic pressure of the pressurized air from the pressurized air source and thus actuates a pneumatic adjusting element so that the mechanical prestress at the air bag is reduced.

Abstract: A chemical oxygen generator has a chemical mixture based on an alkali-metal chlorate (NaClO.sub.3) which constitutes the charge of a cartridge having an ignition device and an oxygen outlet. This oxygen generator is improved so that the charge is insensitive to shock and so that it can be configured in any desired outer form and size and that an advancing reaction zone is assured without a further assisting device. The charge includes a tight bed of chemical pellets which lie one against the other to form the smallest possible contact surfaces.