GB861720A - High altitude suit and mask oxygen regulator - Google Patents

Abstract

861,720. Fluid-pressure servomotor-control systems ; valves. BENDIX CORPORATION. April 1, 1958 [April 1, 1957], No. 9007/58. Class 135. [Also in Group XXI] An oxygen regulator apparatus for simultaneously regulating the flow of oxygen to a breathing-mask and to an inflatable suit includes means for supplying oxygen to the mask in response to inhalation demand when the ambient pressure exceeds that corresponding to a predetermined altitude and means for supplying oxygen to the mask and to the suit at pressure when the ambient pressure is below the predetermined level, the pressures in mask and suit bearing a fixed ratio to one another. Oxygen enters the regulator through an inlet 16 via a pressure-reducing valve 11 actuated by a bellows 12 which is responsive to the pressure in the chamber 14. Oxygen passes to the mask through a valve 18, nozzle assembly 26 and outlet 28. A reduction in pressure in the outlet caused by inhalation affects the chamber 30 through the opening 29 and the diaphragm 34 flexes under the pressure in chamber 35. A boss 36 at the centre of the diaphragm bears on the end of a lever 37, pivoted at 38 and operates the lever 39 pivoted at 40 which opens the valve 18. The oxygen is diluted by air admitted through a valve 66 operated by a bellows 67 which closes the valve as the ambient pressure decreases. An overriding manual control 68 is fitted. When the ambient pressure in chamber 87 falls to that at which oxygen is required to be fed to the mask at pressure then a bellows 88 expands, compresses a spring 93 which bears on a lever 90 and through the spring 92 opens the valve 46, which allows oxygen to flow into the chamber 47 and flex the diaphragm 56 upwardly. This diaphragm is secured to the tube 60, the lower end of which forms the valve 50 and allows oxygen to pass through the tube 60 and to the outlet 28. If the mask pressure exceeds the required value the diaphragm 34 moves downwards and closes the valve 18 and subsequently bears on the centre 62 of the diaphragm 56 and shuts the valve 50. Inflation of the suit commences when a valve 70 opens because the thrust on a diaphragm 81 due to a spring 83 and the pressure in chamber 47 overcomes the thrust due to ambient pressure. Until inflation commences the suit is vented to atmosphere through a valve 75 which is closed by a diaphragm 76 as ambient pressure decreases. As ambient pressure varies in flight, oxygen flows to and from the suit and the chamber 47, oxygen exhausted from the suit passing to the mask. The ratio between the suit and mask pressures is determined by the diameters of diaphragms 56 and 34 respectively. A relief valve 65 prevents excessive pressure in the mask. In a modification the tubular element 60 is without the opening 59 and instead has a side opening connected with the atmospheric space 35. Specification 786,842 is referred to. Reference has been directed by the Comptroller to Specification 804,858.