GB663750A - Improvements in and relating to liquid meters - Google Patents

Abstract

663,750. Liquid meters. BECK & CO., Ltd., and SOAR, H. G. June 7, 1949 [June 4, 1948 ; May 5, 1949], Nos. 15152/48 and 12090/49. Class 69 (ii). The invention relates to liquid meters having pistons which reciprocate under the action of the supply or feed pressure and are rotated as a consequence of such axial movement, the rotation serving to make cyclic changes in the circuits from the source of supply to the delivery point. Each piston reciprocates in a cylinder closed at each end and has in it passages, chambers or bores leading from opposite ends of the piston and terminating at ports in the peripheral surface of the piston. In such meters a transverse passage is provided in each piston. It serves as a balancing passage and in one arrangement transfers liquid from a source of supply to one of the ports in the piston. Fig. 4a shows part of a liquid meter having two pistons 114 which are each connected by means of a known arrangement comprising a pinion co-operating with a crank pin to an indicating mechanism. Reciprocation of the pistons under the influence of liquid pressure causes the pinions to be rotated and the rotation of the pinions imparts a rotary oscillatory motion to the pistons. Liquid under pressure is supplied through a passage 118 and is delivered through a passage 124. Oscillation of the pistons causes bores 146, 148 therein alternately to direct liquid to opposite ends of the cylinders, the pressure liquid passing to the bore 148 through a transfer passage 165 in the piston when the piston has been rotated in a clockwise direction into a position in which this bore communicates with a space 156. The supply pressure acts through the passage 165 upon the underside of the piston and balances the effect of the same pressure acting above the piston. A balancing passage 166 is provided in the piston which at all times communicates with the delivery side of the meter 124, and transmits the delivery pressure to a space 154 where it balances the same pressure acting on the piston at the delivery side. The spaces 154, 156 are formed by a ported liner (not shown). In a modification each piston has three bores for directing the liquid to and away from the ends of the cylinders. In this case two balancing passages are provided but neither acts as a transfer passage for supplying liquid to the cylinder ends. The passage 165 could be replaced by several passages and the passage 166 could be omitted. The bores need not be cylindrical nor need the balancing and transfer passages be cylindrical. Specification 663,762 is referred to. According to the first Provisional Specification the pistons have four bores only three of which play an active part in the operation of the meter. The fourth bore is provided so that the piston is dynamically balanced.