Pinch tube tank level control valve with snap-action shutoff

摘要

A liquid level control apparatus for a flush tank includes an upstanding fill tube integral at its upper end with a valve housing carrying a flexible resilient pinch tube valve member. The valve housing defines a conduit which communicates with a downwardly extending tube parallel to the fill tube. A float has portions respectively receiving the fill tube and the downwardly extending tube therethrough so that the float slides vertically along the tubes as the water level in the tank varies. In one embodiment, an actuator rib on the float fits in a slot in the housing to directly engage the pinch tube valve member, and in another embodiment an actuator pivots on the housing and is coupled by linkage to the float. In the one embodiment an arresting flange on a resilient portion of the float engages an arresting flange on the fill tube for arresting upward movement of the float until the tank is full to provide a snap-action shutoff of the valve. In the other embodiment the coupling linkage includes a control mechanism having a cam slot engageable with a cam follower roller to provide the arresting and snap action.