GB196476A - Improvements in or relating to differential pressure gauges - Google Patents

Abstract

196,476. Jackson, W. J. Mellersh-, (Cochrane Corporation, H. S. B. W.). April 25,1922. ' Pressure gauges.-In differential pressure gauges of the pivoted U-tube type, two thin metal tubes arranged concentrically or side by side along the pivoting axis of the U-tube are used as leading-in pipes for the pressures and are subjected to torsion when the gauge moves. A knife-edge pivot support comprising three planes set in line, the middle one making an angle with the other two, and an improved method of gravity control are used. The high and low pressure tubes N<2>, N' are connected at the bottom by a tube N' and at the top by frame E to which is fixed the knife-edge G and a block H through which connection is made between pipes N, N' leading to the tops of the tubes, and the torsion tubes J, J<1> which communicate through a block K with the sources of differential pressure. Three, planes C<3>, C<4>, C<5>, Fig. 7, on which the Knife-edge G is supported, are formed on a block C which is fixed to a bracket B<3> having an integral sleeve B‹ surrounding the thin tubes J, J'. Downwardly projecting from the centre of the frame E is a cam O having a strap O<3> fixed to it at O<2>, passing over a fixed pulley 0<4> and carrying a weight . O<5>, the cam being shaped so as to render the gauge movements proportional to the square root of the differential pressure and the fixed pulley obviating errors due to swinging of the weight.