Two stage flush control valve assembly

A valve assembly for use with an actuation valve and a source of pressurized fluid for providing a two-stage flush flow for sanitary fixtures or the like, said valve assembly comprising:

• a housing having a flush fluid inlet and a flush fluid outlet including a first outlet portion and a second outlet portion, wherein the actuation valve is disposed in at least a portion of said second outlet portion for controlling fluid flow through said second outlet portion;
• and
• dual valve means including:
• an expandable valve member disposed within said housing between said flush fluid inlet and said first and second outlet portions, and in fluid communication with said flush fluid inlet, said valve member having a proximal end which is capable of sealing off said first outlet portion, a distal end which forms a lifting chamber with said housing in fluid communication with said second outlet portion, an enclosed timing chamber disposed between said proximal and distal ends, at least one restricted opening between said lifting chamber and said flush fluid inlet for providing the pressurized fluid therein, and a restricted orifice fluidly connecting said timing chamber and said lifting chamber with the pressurized fluid;
• and
• a collar movably disposed around said distal end of said expandable valve member and forming therebetween an additional restricted flow path from said flush fluid inlet to said lifting chamber and into said second outlet portion when said expandable valve member is closed;
• wherein activation of the actuation valve initiates a first stage flush by opening said second outlet portion to draw fluid out of said lifting chamber and to said second outlet portion, thereby drawing said dual valve means away from said first outlet portion to provide fluid communication between said fluid inlet and said first outlet portion, allowing said proximal end of said expandable valve member to move away from said first outlet portion to permit a primary flush fluid stream to exit through said first outlet portion, and allowing said collar to come to rest against said housing proximate a portion of said second outlet portion to enable opening of said restricted flow path;
• wherein said distal end of said expandable valve member is drawn toward a portion of said second outlet portion and away from said collar to initiate a second stage flush by permitting a fluid stream to flow from said flush fluid inlet and out through a portion of said second outlet;
• wherein said primary flush fluid stream flowing around said expandable valve member causes said valve member to expand through movement of said timing chamber and said lifting chamber;
• and
• wherein a second stage is initiated when said valve member expands to the extent that said proximal end seals off said first outlet portion to terminate said primary flush fluid stream, and wherein said secondary flush fluid flow continues through said restricted flow path and out said second outlet portion.