GB191401902A - An Improved Self-contained Rescue or Breathing Apparatus for use in Mines or other Places containing Impure Air. - Google Patents

Abstract

1902. Parker, J. Aug. 20. Inhalers and respirators. - In miners' or other breathing-apparatus, the oxygen is supplied to the inhaling side through a sensitive and compact adjustable reducing - valve and through a regulator by which a minimum supply of, say, ¥ litre per minute may be increased in steps of, say, “ litre. The oxygen passes from the cylinder through the fibrous filter 2 and valve orifice 4 to the passage 5 and annular chamber 31, nozzle 19, and outlet pipe P of the regulator, while the determined pressure is maintained constant by oxygen that passes from the valve chamber C through openings 6, Fig. 3, and tends to depress a metal or rubber diaphragm 7 against the action of an adjustable spring 8 and so draw down the attached sliding piston 26 and close the valve 4 by the plug 11 or metal cone 12. A safety-valve 13 with its regulating-spring 14 is provided within the piston. The regulator comprises concentric cylinders 15, 16 forming the annular chamber 31, which is provided with the ever-open nozzle 19, and a series of nozzles of increasing size normally closed by a plug 18, but into register with any one of which one of two openings 17 may be brought by rotation of the graduated head 21 of the plug. The plug is held in any position by a stop 22 having a shield 25, and the nozzles are protected from dust by wiregauze 20. The regenerative apparatus described comprises a mouthpiece or half-mask provided with inlet and outlet valves connected to the respective compartments of a breathing-bag in circuit with a caustic-alkali purifier having two passages in parallel. Resistance to the air circuit is also reduced by making the valves large and the tubes wide and, as far as possible, without bends.