| 摘要 |
<p>There is disclosed a level control valve arrangement preferably for use in a water closet cistern for controlling the liquid level in the cistern or container. The arrangement has a liquid inlet (3) feeding an inlet chamber (1) and a movable valve member (7,10) mounted on a seating (11,12) and movable between an open position in which liquid flows from the inlet into the cistern and a closed position in which liquid is prevented from flowing into the cistern. The movable valve member is biased preferably by a float arm into the closed position in response to liquid in the cistern rising to a predetermined level. The movable valve member (7,10) is mounted in the inlet chamber into which water is fed from the inlet (3) and in the closed position the valve is acted upon by a head of water in the inlet chamber to maintain the movable valve member in the closed position. The control system is distinguished by the use of water head pressure upon an upper conical surface of the movable valve member during closure thereof thereby increasing the compactness area upon its base. When releasing the movable valve member the conical form of the valve member exceeds the water pressure on the movable member during closure and slackens the pressure on it during opening. Advantageously, such an arrangement ensures there is no leakage of water into the cistern, the inlet valve is not affected by changes in water pressure of the inlet supply, and the contact area of the valve is substantially increased providing a considerably reduction of wear of the valve, particularly the rubber washer between the movable valve member and seating of the inlet chamber. Conveniently, the speed of water exiting from the expulsion valve opening is increased to more quickly and easily clean a lavatory for example. <IMAGE></p> |
