GB718169A - Improvements in demand pressure regulator - Google Patents

Abstract

718,169. Respiratory appliances. SCOTT AVIATION CORPORATION. Oct. 2 1952 [Feb. 7, 1952], No. 24723/52. Class 81(2) A demand regulator for high altitude breathing equipment has resilient means for bearing, through a disc-shaped pressure plate, on the control diaphragm, the additional thrust being manually set according to particular ranges of altitude. An annular stop plate is provided to limit the movement of the plate in the retracted direction. The demand valve 21 is actuated by a rod engaging the control diaphragm 14 when the user inhales. Adjacent to the outer face of the diaphragm is a pressure plate 28 carried on a lever 32, pivoted at 34 and normally urged towards the diaphragm by a spring 38. A projection on the upper end of the lever may, however, be engaged by a cam on a control shaft 42, which holds the arm 32 and plate 28 clear of the diaphragm against an annular stop 27. Rattling, due to looseness, is avoided by the use of a spring 30. The upper part of the lever 32 also carries a common bail 49, which may be engaged by bell cranks, similar to 37, each urged in a clockwise direction by a spring, similar to 38, so as to 'increase the pressure on the plate 28 but each of these bell cranks may be rendered ineffective by a further cam, on the control shaft 42, when the latter is turned manually to the appropriate setting.