GB1532491A - Flapper flush valve - Google Patents

Abstract

1532491 Cisterns AL SCHMIDT 23 Jan 1976 02719/76 Heading E1C [Also in Division F2] In a cistern flushing flap valve the amount of water discharged from the cistern is controlled by varying the buoyancy of a ventedfloat chamber by admitting water to it. The flap valve 20, of an elastomer such as rubber has a sleeve 28 for attaching the valve to an overflow pipe, a hinge portion 26, a closure portion 22 for sealing an outlet from the cistern and a flat chamber 34. In a first embodiment, Fig. 3, a ball check valve 46 controls the entry of water to the float. If an operating chain 42 is pulled gently the ball seals the entry and the float preserves its buoyancy resulting in a full flush of the cistern. If, however, the chain is jerked the ball will fall into the main part of the chamber, water will enter the float chamber and the valve will close before the cistern has fully emptied resulting in a saving of water. In a modification, Figs. 7, 8 (not shown) a rotary sleeve insert (90) having a slot in its side is provided in the water inlet to the float to achieve a variable flushing action. In a second embodiment, Fig. 9, the ball check valve is provided in a pocket on the inside wall of the float to control the venting of air directly. In this case, however, a gentle pull fails to dislodge the ball and the air is still vented, resulting in a partial flush. A more vigorous pull dislodges the ball, venting of air is stopped and a full flush results. In a yet further embodiment, the check valve may be dispensed with, the water dispensed being in accord with the setting or diameter of the water inlet orifice in the float.