| 摘要 |
A toilet tank fill valve assembly is disclosed, in which the tank water level at which the valve opens is different from the tank water level at which the valve closes. The valve has a substantially vertical rod, which moves up to activate a lever to allow the ballcock valve to close, and moves down to activate the lever to open the ballcock valve. The rod has upper and lower stops, preferably adjustable, corresponding to the valve closing and valve opening positions respectively. A float lifts the upper stop when the tank becomes full, thereby allowing the ballcock valve to close. A weight pushes the lower stop down when the tank becomes empty, thereby opening the ballcock valve. The float and weight may be separate units, or may be a single unit which rides up and down on the rod between the stops. Embodiments are described in which the valve is positioned either above or below the tank-full water line, a ball-seat check valve being provided in the latter case to prevent the backflow of water from the tank into the main water supply if the main supply is disconnected. A polyethylene filter is provided on the inlet side of the valve. |
