| 摘要 |
PURPOSE:To produce a sufficient difference in water level between the water level at the time of closing a valve and the water level at the time of opening the valve by pivoting an opening and closing valve body of a discharge port on one end of a lever, and fixing a float to the other end thereof in such a manner as to vertically move up and down freely within a fixed range. CONSTITUTION:At a water level A, a float 12 is stationarily reposed on the upper portion of a support rod 11 by buoyancy, and a valve body 5 is pressed and closed by hydraulic pressure. When the water level is lowered with consumption of reservoir water, the float 12 is lowered, but the valve body 5 is kept in the closing state because it receives a closing pressure action of hydraulic pressure. When the water level is further lowered, the lower surface of the float 12 is brought into contact with a stopper mounted on the lower end of the support rod 11 to work dead load of the float 12 upon the support rod 11, so that the force for opening the valve is gradually applied to the valve body through the lever 9. At the water level B, the force for opening the valve produced by application of dead load of the float 12 surpasses the force for closing the valve produced by hydraulic pressure, so that the valve body 5 is opened to supply water from a discharge port 3. |
