Push button toilet flush mechanism

A push button toilet flush mechanism for installation within a water storage tank associated with a toilet bowl, said flush mechanism comprising:

• a base member for being positioned proximate a bottom of the storage tank oriented along a length of said storage tank, said base member having a flapper assembly support portion and an oppositely disposed trigger assembly support portion;
• a drain portion carried by said base member for carrying water from the storage tank into the toilet bowl, said drain portion having a top rim and an annular shoulder positioned proximate said top rim, said rim defining an opening into said drain portion;
• a gasket member surrounding said drain portion and supported on said shoulder, said gasket member extending to a level above said top rim;
• a flapper assembly having a flat plate with a first surface to seal against said gasket member when water is not to be removed from the storage tank, said flapper assembly further having a bulb portion attached to said first surface of said flat plate to be received within said opening into said drain portion, said flat plate having one end mounted on a pivot of a pivot assembly on said flapper assembly support portion of said base member whereby said flapper assembly can be selectively pivoted toward and away from said drain portion, said flat plate further having a side extension;
• a water storage volume for receiving water from within the storage tank when water within the storage tank is at an upper level, said water storage volume having an opening of adjustable size in a bottom wall for release of water when the storage tank is substantially empty of water;
• a web member joining said water storage volume to a surface of said flat plate opposite from said bulb portion, said web member having a length whereby said water storage volume, when containing water, is a counterweight to said flat plate and bulb portion such that said flapper assembly remains in said open position for a selected time sufficient to re-engage said distal end of said trigger arm with said distal end of said lever arm;
• a standpipe carried by said base member and wherein said drain portion is provided with an overflow outlet communicating with said standpipe whereby water flowing into said standpipe is directed to said drain portion;
• a lever arm having a first end and a distal end, said first end pivotally mounted on said pivot assembly on said flapper assembly support portion of said base member whereby said lever arm can be selectively pivoted in a plane substantially parallel to a plane of motion of said flapper assembly, said lever arm having a portion for engagement with said extension of said flat plate of said flapper assembly when said lever arm rises from a lower position to an upper position;
• a buoyant float member carried by said lever arm, said buoyant float member moving in response to water level in the storage tank;
• a trigger assembly mounted on said trigger assembly support portion of said base member and extending substantially vertically within the tank, said trigger assembly having a trigger arm pivotally mounted on a trigger pivot within said trigger assembly, said trigger arm having a first end provided with a disk member disposed upwardly from said trigger pivot and a distal end extending toward said base member, said distal end of said trigger arm engaging said distal end of said lever arm when water is substantially removed from the tank thereby preventing pivoting of said lever arm by said buoyant float member when water is placed within the tank, said trigger assembly further having a counterweight attached to said trigger arm intermediate said first end of said trigger arm and said trigger pivot to bias said trigger arm in a position to engage said distal end of said trigger arm and said distal end of said lever arm;
• and
• a push button assembly mounted within a wall of the tank, said push button assembly having a push rod with a first end exterior the tank carrying a push button, and a second end having an enlarged diameter portion in contact with said disk member whereby movement of said push rod toward said disk member produces pivotal movement of said trigger arm and disengages said distal end of said trigger arm from said distal end of said lever arm whereby said buoyant float member moves said lever arm to said upper position and said flapper assembly to an open position by engaging said side extension of said plate of said flapper assembly.