Patent ID: 6961966

Claim:
A toilet overflow prevention device for use with a toilet having a tank, a bowl, a passage connecting the tank and the bowl, and a flush valve selectively permitting water to move from the tank to the bowl, the device comprising: an overflow valve having an open position, wherein water is permitted to flow past said valve, and a closed position, wherein water is substantially prevented from flowing past said valve and into the bowl: an actuator including a water level sensor configured to sense an above-normal water level in the bowl of the toilet, said water level sensor comprising: a main flow passage having a first end and a second end, said first end configured to receive a flow of water from a water supply source of the toilet, said second end defining a discharge opening; a first branch flow passage having a first end and a second end, said first end communicating with said main flow passage and said second end defining a first inlet opening positioned at said above-normal water level, and a second branch flow passage having a first end, a second end and a valve between said first and second ends, said first end communicating with said main flow passage and said second end defining a second inlet opening; wherein when said first inlet opening is not immersed in water, said valve is moved to a first position and said actuator permits said overflow valve assembly to move to said open position, and when said first inlet opening is immersed in water, said valve is moved to a second position and said actuator moves said overflow valve from said open position to said closed position, thereby preventing water from flowing from the tank into the bowl.