GB461381A - Improvements in or relating to apparatus for controlling or indicating liquid levels - Google Patents

Abstract

461,381. Ball - and - float valves. ATELIERS NEYRET - BEYLIER & PICCARD - PICTET. Jan. 25, 1936, No. 2412. Convention date, May 14, 1935. [Class 135] [Also in Groups XVIII and XXI] A float F, Fig. 2, carried by a pivoted arm B<1> is limited by two cylindrical walls C<1>, C<2> so that liquid pressure on these walls has no turning moment, and by a bottom surface A the plane of which passes through the axis C, the latter surface providing the only turning moment on the float. An opposing turning moment is exerted by a counterweight P so treated that the centre of gravity of the structure is on a point G on a plane at right angles to the plane X. The apparatus is so constructed that the opposed moments are equal, i.e. the float is in neutral equilibrium when the liquid level passes through O. If the level rises slightly, the float rises until the surface A reaches liquid level. Conversely, on a fall of level, the float falls throughout its permitted range, i.e. until a supplementary float f reaches the liquid level. In a modification, Fig. 3 (not shown), the counterweight P is wholly immersed, and in Fig. 4 (not shown), the counterweight is replaced by a spiral spring. In another modification, Fig. 5 (not shown), the curved walls C<1>, C<2> are prolonged below the bottom wall A, so that the float can rise until the wall A is above liquid level. In another modification, Fig. 6 (not shown), the critical liquid level is not that of the axis, an additional counterweight with fixed leverage being employed. If the counterweight is made adjustable, the critical level may be varied. If the arm B<2>, Fig. 2, does not pass through the point O and the weight P is adjustable along it, the apparatus has a different position of equilibrium for each position of the weight P, and may be used for indications or actuations depending on levels. In effect, a magnified indication of change of level is given. In Fig. 8, the closed portion F of a drum serves as the float and liquid is admitted through opening b to act upon the radial surface C<12>. If the opening b is small, oscillations due to changes of level are damped. Alternatively, damping may be obtained by a blade projecting from the float into the liquid. In Fig. 14 (not shown), a tank discharges through an orifice, and constant delivery is obtained by a float in the tank which regulates a valve controlling the inflow. The volume of the float is comparable with that of the tank, and the apparatus is adjusted so as to be in unstable equilibrium at a critical height. Any tendency of the level to fall, e.g. by cessation of supply, is compensated by a fall of the float to displace the level upward to its critical level. Specification 20616/07, [Class 135], is referred to.