GB1115692A - Improvements in or relating to a device for generating a variable function - Google Patents

Abstract

1,115,692. Flow meters. J. SORTEBERG. Jan. 14, 1966, No.1935/66. Heading G1R. [Also in Divisions F2 and G3] In an instrument the output signal of which is proportional to the mass flow rate of a gas through an orifice 15 in a duct 14, a device I for deriving a mechanical output Y=Kx=C where x is a variable mechanical input and C and K are constants, comprises input and output thrust members 5, 10, both pivoted to a roller 8 which bears against an angularly adjustable plane 9 the setting of which determines the constant K, an adjustable compression spring 11 acting on a collar 12 of the member 10 to provide the constant C, and bellows 1 which convert a fluid pressure input into a mechanical input to the member 5. Signals from temperature and pressure sensing elements 16, 17 and fed to respective devices I, II, which are similar, and the outputs A, B of these devices, representing absolute temperature and pressure, act on a beam W 1 having a fulcrum R 1 . A vane 19 on the beam controls a nozzle N L to provide an air pressure signal 21 to an air motor AM causing the latter to adjust the fulcrum position to balance the beam W 1 . A signal of the pressure difference across the orifice 15 is fed from a transmitter 18 to a bellows unit IV to produce a thrust D on a beam W 2 the fulcrum R 2 of which moves with the fulcrum R 1 . A vane 20 on the beam W 2 controls a nozzle N R to provide an air pressure signal 22 to a bellows unit III providing a balancing thrust C on the beam W 2 , the signal 22 also forming the output of the instrument.