Image Number 18 for United States Patent #6934976.
A tank-type flusher includes an intake valve, i.e., a fill valve, a diaphragm-operated flush valve, and a pressure control mechanism. The intake valve is connected to an external water source and is constructed to close water flow to a water storage tank at about a predefined water level in the water tank. The diaphragm-operated flush valve is constructed to control a flush valve member between a seated state and an unseated state allowing water discharge from the water tank into a toilet bowl. There is a diaphragm, separating a flush-valve chamber and a pilot chamber, arranged to seal the flush-valve chamber and thereby maintain pressure forcing the flush valve member to the seated state preventing the water discharge from the water storage tank to the toilet bowl. The pressure control mechanism is constructed and arranged, upon actuation, to reduce pressure in the pilot chamber of the diaphragm-operated flush valve to cause deformation of the diaphragm and thereby reduce pressure in the flush-valve chamber causing the water discharge.