Patent ID: 6360378
Filing Date: 2002-03-26
Classification: E03D

Abstract:
A pressurized water closet flushing system having a flush cycle comprising a water discharge phase and a water fill phase, said system comprising:an accumulator vessel for storing water and air above ambient pressure and maintaining above ambient air pressure on said water throughout the water discharge phase of the flush cycle; a water inlet in said accumulator vessel connected to and open at all times to a source of water under pressure; a water outlet from said vessel; an air pressure differential actuated flush valve assembly for controlling the discharge of water from said water outlet comprising: a cylinder extending vertically above the water outlet in said vessel and having a lower end in fluid communication with the outlet of said vessel; a vertically movable piston having an annular seal on its outer periphery slidably engaged with an inner wall of said cylinder and defining upper and lower chambers therein, the upper chamber in said cylinder having a normally closed air discharge outlet therein; a permanently open air metering orifice in said piston providing communication between the upper and lower chambers of said cylinder; an aperture in said cylinder providing fluid communication between the interior of said accumulator vessel and the lower chamber in said cylinder; a valve on said piston normally closing said water outlet and operable upon upward movement of said piston to permit the discharge of water through said outlet; a spring normally biasing said piston and the valve thereon downwardly to the closed condition; and a normally closed flush valve actuator operable to open communication between the air discharge outlet in the upper chamber of said cylinder and ambient air pressure thereby to create an air and water pressure differential across said piston having an upward bias thereon to effect upward movement of said piston and opening of said valve while maintaining above ambient air pressure within said vessel to facilitate discharge of water therefrom under pressure greater than ambient; closure of said actuator effecting closure of the upper chamber of said cylinder whereby downward movement of said piston under the bias of said spring is attenuated by the creation of a pressure differential across said piston having an upward bias on said piston, the pressure differential across said piston being dissipated by the flow of air upwardly through the metering orifice therein so as to condition said piston for downward movement under the bias of said spring and closure of said valve after a predetermined time period.