Apparatus for pressure assisted flush toilets

A toilet flush apparatus for a toilet bowl, comprising an enclosed flush tank for holding water and air under pressure, a feed valve for connecting a pressurized water supply source to said flush tank, volume control means for controlling the water volume of a flush, and a flush valve for connecting said flush tank to the toilet bowl to control water discharge from said flush tank to said toilet bowl, said feed valve having actuating means for opening said feed valve and consequently communicating a feed water flow from said water supply source to said flush tank, said feed valve remaining open when the flowrate of said feed flow is higher than a predetermined low flow threshold and closing automatically when said flowrate is reduced below said low flow threshold, said volume control means reducing said flowrate below said low flow threshold when a predetermined water volume is accumulated in said flush tank thereby causing the feed valve to close, said flush valve controlling the discharge flow from the flush tank to the toilet bowl in response to hydraulic conditions of both said feed water flow and pressurized water held in said flush tank such that when feed water flows, said flush valve closes automatically to allow the feed flow to be accumulated in said flush tank, and when said feed water flow stops, said flush valve opens automatically in response to the pressurized water in said flush tank to allow the water to discharge.