GB995968A - Improvements in or relating to pressure controllers - Google Patents

Abstract

995, 968. Fluid-pressure servomotor systems. NORMALAIR Ltd. March 20,1964 [March 23,1963], No. 11620/63. Heading G3P. A pressure controller includes a container 6 which is completely sealed except for pressure tappings 11,12,13 taken therefrom, one of the tappings 13 being for the purpose of controlling the pressure in an enclosure 1, such as an aircraft cabin, outside the container, a second tapping 11 providing communication between the container and the enclosure through a restricted orifice, and a third tapping 12 having a restricted orifice in alignment with the first-mentioned orifice and arranged to be in communication with the atmosphere outside both the enclosure and the container, pressure responsive means 2, 3 located outside the container and arranged to be freely subjected to the pressure in the enclosure, and an obturating member 10 within the container for controlling the flow through the second and third tappings under the control of the pressure responsive means so as to modify the pressure in the container in response to pressure changes outside the container, the obturating member being located between the two orifices so that its movement closes one while freeing the other, and vice versa. The obturating member is fixed to a torsional diaphragm 9, such as that described in Specification 995, 969, so that it is moved in a pivotal manner by the pressure responsive means consisting of a capsule 2 communicating with atmosphere through a duct 5 and responsive to the difference in pressure between the enclosure and the atmosphere and a capsule 3 responsive only to the pressure in the enclosure. When the obturating member is moved by the capsules, the flow through the container 6 is regulated to provide the requisite actuating pressure at a discharge valve 14 to keep pressure conditions within the enclosure stable. The capsules may be connected to the obturating member by electrical means.