GB252470A - Improvements in or relating to fluid pressure indicators - Google Patents

Abstract

252,470. Paul, R. W. March 3, 1925. Elastic diaphragm pressure-gauges.-Comprises a bellows fitted with a spring device which acts to maintain constant the direction of expansion and contraction of the bellows. The component parts are mounted on a plate A and enclosed within a casing with bezel A<1> held to the plate by studs A<2> which also carry the dial. The bellows C<1>, C<2> are fixed to a block B carried by the plate A. Internal passages in the block connect the bellows with outlets. The free ends of the bellows are coupled together by rods D<1>, D<2>. Mounted on the plate of the lower bellows is an arm C<3> with a clip C' to which is attached one end of the minor axis of an elliptical bow spring E, the other end of the axis being fixed to the frame E<2> by an adjustable, angle-piece E<1>. A light chain or thread F is attached to and wrapped around the indicating spindle, which is carried freely in plates E<3>, the other end of the chain being attached to the arm C<3>. A hair spring F<3> keeps the chain taut. In gauges for comparing pressures with atmospheric pressure the bellows C<1> and attachments are omitted. The spring E may be made in two bowed parts connected at the ends. To correct readings for temperature a bimetallic strip may be used either to move the dial or to move the point at which the bow spring is attached to the frame. In the latter case the strip rocks a spindle having right and left handed threads engaging clamps to the right and left of the bracket E' and bearing on the spring, thus altering its effective length.