GB477493A - Improvements in or relating to automatic regulating apparatus - Google Patents

Abstract

477,493. Fluid-pressure servomotorcontrol systems. ELECTROFLO METERS CO., Ltd., and LAMBERT, L. B. Jan. 28, 1937, No. 2497. [Class 135] In automatic regulating-apparatus for controlling a variable condition such as temperature or pressure comprising an angularly displaceable pointer or recording element 2 coupled with an element, such as the Bourdon tube 5, responsive to the controlled condition and with a baffle 8 co-operating with a vent member 10 carried by an arm 12, angularly displaceable about the same axis as the pointer 2, a pilot valve 28 controlling a servomotor or other pressure-responsive means for controlling the variable condition, is actuated through a pressure-multiplying device such as the lever 50 by a diaphragm or bellows 44 controlled by the baffle 8. The vent arm 12 is adjustable by hand-operated gearing or by a clockwork driven cam where a cyclic variation is desired. The baffle 8 may be adjustably hinged at the end of its arm 9 and shaped to give any desired control characteristics. The chamber 44 is fed continuously with compressed air through a restriction 41 in a pipe 24 containing a pressure gauge 23. The pilot valve 28 is in the form of a loose ball and controls the operating pressure in a pipe 34 with a gauge 37.