GB707719A - Improvements in or relating to mixing valves - Google Patents

Abstract

707,719. Manually-actuated multiple-way valves. SHEARDOWN, J. M. July 25, 1952, No. 18924/52. Class 135 A valve for mixing two separate supplies of liquid comprises a casing with an inlet port for each liquid and an outlet port for the mixture, the three ports being controlled by separate, longitudinally-spaced, closure members carried on a plunger longitudinally movable either to shut off the flow through the valve or to control the ratio of the flows through the inlet ports, and the intermediate closure member has passages therethrough for liquid. In an embodiment, hot and cold water flow into the valve casing through passages 2, 3, respectively, the entry of hot water being controlled by a lift closure member 27 on the lower end of the plunger stem 10 and the entry of cold water being controlled by a land 24 on the stem. After mixing, the liquid flows through passages 32 in a land constituting a guide for the stem and past a lift closure member 21 near the upper end of the stem to an outlet port 8. The land 24 is provided with passages 25 to lead the hot water to the mixing chamber 6. Closure member 27 carries an extension 30 which allows only a leakage flow of hot water until the extension rides clear of the port opening. The plunger engages rotatably at its upper end in a screwed spindle 13, the latter carrying a handle 18 and engaging in a fixed nut 19. In a modification, the land 32 is omitted and the land 24 has horizontal, instead of oblique, upper and lower surfaces.