Adjustable toilet tank valve to regulate flush water volume

Claim 1

A flapper valve to be used with a toilet tank for selectively controlling the quantity and volume of water discharged from the tank at a discharge outlet into a discharge pipe during each flush by reducing the buoyancy of the flapper valve by permitting water inflow into the said flapper valve during the flushing operation, said flapper valve comprising in combination: (a) an upper valve body portion fabricated of a relatively flexible, elastomeric material, said upper body including: (i) an annular flange for engaging the discharge outlet and for sealing the discharge outlet against water flow into the discharge pipe from the toilet tank when the valve is in a first closed position: (ii) a side wall integrally formed with and depending from said flange, said side wall having a lower peripheral edge; (iii) mounting means for pivotally mounting said flapper valve to permit movement of said flapper valve from said first closed position to a second position raised above the discharge outlet and within the water toilet tank to permit water flow through the discharge outlet from the toilet tank when a flushing operation is commenced; (iv) an air vent disposed in a predetermined location in the side wall for venting air from said valve body, said air vent being of sufficient size to prevent it from materially affecting the rate of water flowing into the said valve; and (v) said vent being located in said side wall at a generally diametrically opposed position from said mounting means for positioning said vent in the upper part of the valve upper body when said flapper valve is in the second position; and (b) a cone cap having sufficient rigidity so as not to appreciably deflect or flex during the flushing operation, said cone cap having a side wall with an upper peripheral edge and a lower end wall, said cone cap being in engagement with the upper valve body with the side wall of said cone cap extending downwardly from the lower peripheral edge of the upper valve body wherein said cone cap and said upper valve side wall form the wall of an interior buoyancy chamber; (ii) whereby said cone cap provides sufficient support to the upper valve body side wall so the side wall will not appreciably deform under operating conditions in the toilet tank; and (iii) said cone cap lower end wall defining means for adjusting the size of at least one through passageway therein to regulate the water inflow rate into the buoyancy chamber as a function of the size of the passageway.