Patent ID: 7047574

Claim:
A system for varying the volume of liquid held by a toilet bowl following a flush, said system comprising: an inlet valve interposed between a source of liquid and a toilet bowl, wherein said inlet valve has an open position in which said inlet valve allows liquid from the source of liquid to enter the toilet bowl and a closed position in which said inlet valve prevents liquid from the source of liquid from entering the toilet bowl; a flushing mechanism which is operatively connected to actuate said inlet valve, causing it to go from said closed position to said open position when said flushing mechanism is actuated, allowing liquid from the source of liquid to enter the toilet bowl to flush the toilet bowl, whereupon the liquid entering the toilet bowl causes the contents of the toilet bowl to be substantially expelled from the toilet bowl into a sewage disposal system in a flushing operation, following which the liquid entering the toilet bowl refills the toilet bowl; and a liquid volume controller which controls the closing of said inlet valve to vary the volume of liquid held by the toilet bowl following each flush such that the level of the liquid held by the toilet bowl following flushing is varied and the formation of a ring of chemical deposits on the toilet bowl is thereby impeded.