GB602187A - Oxygen demand pressure breathing regulator - Google Patents

Abstract

602,187. Respiratory apparatus. GARRETT CORPORATION. Sept. 18, 1945, No. 24030. Convention date, Sept. 4, 1944. [Class 81(ii)] [Also in Group XXIX] An oxygen; regulator for aviators' breathing apparatus, shown schematically in Fig. 8, comprises a casing 14 with a flexible wall 17, protected by an apertured cover plate 18, an oxygen inlet valve 20 opened by the inward movement of the wall 17, an opening communicating with the mask, an exhalation valve 63, and a leverage system 66, 68, 70 transmitting pressure exerted by spring 78 to move the flexible wall inwardly and to close the exhalation valve, the distances between the points of application of forces F, F2 and F, F3 being inversely proportional to the areas of the flexible wall and exhalation valve respectively, whereby the latter are co-ordinated throughout the range of adjustment. This adjustment is altered by variation of the tension of spring 78. The following figures show the actual construction of the regulator. In Fig. 4, spring 78 is connected at one end to the arm 80 of an adjusting knob 82 formed with a spring- pressed detent member 83, and at the other to a pivoted arm 75 bearing through adjusting screw 77 onto the bell crank lever 70 of the leverage system. The oxygen inlet valve assembly, Figs. 5 and 7, comprises a chamber 24 communicating through passages 37 in valve seat 36 with the interior of the regulator casing, and a front spring-urged valve member 32 and gasket 34. A rear valve member 28, seating against gasket 31 screws into member 32 and is frictionally held by fingers 40. Valve stem 43 is engaged by lever 44, Fig. 5. actuated by pin 56 disposed in the stem 54 connected to diaphragm 17, the lever 44 being pivoted in a bracket 48 adjusted by means of screw 52.