US Patent 10578228 Sensing mechanism for valve operation

A flush valve assembly has a pilot valve and a drive train for selective driving the pilot valve between an open position and a closed position. The drive train has a drive gear coupled to a motor for rotating the drive gear and a valve gear coupled to the pilot valve and intermeshing with the drive gear. At least one of the drive gear and the valve gear have a flag extending outwardly therefrom. A sensor positioned to detect the flag and establish a rotational position of the drive gear and the valve gear to thereby establish an opened or closed position of the pilot valve.