Breath protection device with circulation of the breathing air and the lungs failed valve controlled breathing gas.

摘要

923,990. Respiratory appliances. O. H. DRAGER, [trading as HEINR DRAGERWERKE & BERNH DRAGER]. Sept. 4, 1961 [Sept. 2, 1960], No. 31785/61. Class 81 (2). In a closed-circuit breathing-equipment a pressure-sensitive device, influenced by pressure within the circuit, controls a closure means which arrests flow around the circuit and also controls an oxygen supply valve. In one form, exhaled gas from a mask passes through a duct 1 to a carbon-dioxide absorber 2 and thence to a breathing-bag 4 leading through an inhalation valve 7 back to the mask. A diaphragm 15 is mounted across the duct 3, leading from the absorber to the breathing-bag so that, when the user inhales, the pressure difference moves the diaphragm towards the right whereupon a spring-loaded valve 17, carried by the diaphragm, is opened by striking an adjustable stop 20. At the same time a bridge member 18, also mounted on the diaphragm, opens a tilting valve 23 to admit oxygen to the system from a pressure regulator 10 and supply cylinder 8. In modifications the diaphragm assembly is located to replace the inhalation valve while in one of these the valve comprises a seating mounted on the diaphragm and normally closed against a fixed stop, so as to be opened on movement of the diaphragm.