GB592093A - Improvements relating to governing devices for regulating fluid pressure systems - Google Patents

Abstract

592,093. Fluid-pressure servomotorcontrol systems ; valves. OLIVER, A. G. Jan. 4, 1945, No. 377. [Class 135] A governing device for fluid-pressure systems comprises an apertured sleeve connected at one end to a fluid-pressure system and at the other to an exhaust system, variations in pressure in the fluid-pressure syntom moving a valve member axially within the sleeve so that the aperture or apertures on one side of the valve member are closed whilst those on the other side are opened whereby the pressure in a housing surrounding the sleeve and communicating with a fluid pressure operated regulating unit is varied to effect movement of the unit. As shown, the governing device comprises a control unit, Fig. 1, and a regulating unit. Fig. 2. The control unit comprises a housing 1 in which a sleeve 2 is held by a bush 3 and a union nut 7. A ball 9 moves with slight clearance in the sleeve 2 and is pressed towards the union nut 7 by a spring 11 adjustable by a non- rotatable screwed spindle 14 moved axially by a nut 18. The nut is rotated by a handle 19 and prevented from moving axially by a flanged nut 17 screwed on to an extension 15 of the housing 1. An annular space 4 between the housing 1 and the sleeve 2 communicates with the interior of the sleeve by a slot 8. Besides the union nut 7, the housing has a connection 20 to the regulating unit, two diametrically opposite connections 21 serving as to a pressure gauge or to another regulating unit, and a connection 23 to atmosphere or to an exhaust or system or to the suction side of a pump. The regulating unit comprises a spring-loaded piston 26 moving in a cylinder 25. The latter has a connection 30 joined to the connection 20 of the control unit by a pipe 22, and a connection 31 to atmosphere or the suction side of the pump. The two sides of the piston may be connected by an adjustable byepass valve 32 having a head portion notched on one side to connect. passages 33, 34. The piston rod may be connected by a coupling 29 to a balanced steam throttle valve or to the electric starter for a pump or to a reducing valve. In operation, the spring-loaded ball 9 moves under the influence of the controlling pressure over the slot 8 creating a greater or less pressure in the space 4 and hence in the operating cylinder the piston of which consequently regulates the steam valve or other means governing the pressure system. The slot 8 may be replaced by a series of small holes arranges spirally around the sleeve where the controlling fluid is a gas or a light liquid. Where the pressure in the system is too low to operate the control unit, the latter may be operated by the pressure of a small pump driven by an engine or from the shaft of a low pressure fan or water circulator in the system. A smaller control unit may be installed as a relay between the operating unit and the main control unit. The control units of several dispersed regulating units may be grouped together in one place.