GB1023605A - Improvements in or relating to pressure regulators for aircraft breathing systems - Google Patents

Abstract

1,023,605. Respiratory appliances. WALTER KIDDE CO Ltd. Sept. 25, 1964 [Oct. 1, 1963], No. 38557/63. Heading A5T. Breathing apparatus comprises a combined pressure regulator 2 and jerkin inflation valve 4 having two oxygen inlets 8, 9 (Fig. 2, not shown) for connection with main and emergency oxygen supplies respectively, the jerkin inflation valve being downstream of the regulator and arranged to open when the pressure in the outlet side of the regulator exceeds atmospheric pressure by a predetermined amount. The combined pressure regulator and jerkin inflation valve is secured to the fabric 5 of a jerkin by studs 6. The main oxygen inlet 8 is closed by a valve 81, when disconnected from the main oxygen supply, when the emergency oxygen inlet is used. The main oxygen source supplies, at each inhalation, at lower altitudes a metered quantity of oxygen, which is insufficient to meet a normal demand, and, at higher altitudes a continuous uniform supply. On inhalation, a diaphragm 17, which is exposed on one side to the ambient pressure and on the other side through a passage 19 with the inlet passage 18 to a breathing mask, moves a lever 24<SP>1</SP> to open a valve 27 so that pressure is reduced on the undersurface of a diaphragm 22. The diaphragm 22 then moves to open an oxygen inlet passage 20 so that oxygen flows through passages 21, 21<SP>1</SP> to the mask inlet passage 18. When, at lower altitudes the pressure at the inlet 8 drops, the inspiration valve 31 opens against a spring 32 to supply the remainder of the gas required for inhalation. The inspiration valve is connected by a rod 35 to a piston 36 which is slidable in a cylinder 34. The cylinder has an inlet 38 connected through a part 39 with the main oxygen supply, so that, when the oxygen supply pressure is high, the piston is raised to hold the inspiration valve closed at the beginning of an inhalation at lower altitudes and at higher altitudes. The jerkin inflation valve comprises a valve member 51 supported on one side of a diaphragm 53. The valve member is normally held closed against a magnetic seat 52 and the other side of the diaphragm is exposed to the ambient pressure through a tube 58. The valve member 51 is set to open at an ambient pressure above that at which the oxygen supply source operates to supply oxygen continuously at uniform pressure. When the ambient pressure falls below a predetermined amount, an aneroid capsule 45 closes communication between one side of the diaphragm and the ambient atmosphere, this side of the diaphragm then being maintained at a pressure above the ambient pressure through a passage 40 connected with the oxygen inlet passage 20.