US Patent 7185664 Fill control system for an in sink dishwasher

A dish-cleaning appliance comprising a sink having a bowl defining a wash chamber with an open top for providing access to the wash chamber. A liquid recirculation system is provided for spraying liquid throughout the wash chamber. A drain conduit can be provided, alone or in combination with the recirculation system, for draining liquid from the wash chamber when the drain is closed. A fill control system is provided to ensure that the dishwashing cycle is not started with liquid in the wash chamber and that the sink drain is properly closed. One or more sensors can be provided for enabling the fill control system. The sensors can be located within the drain above the location where the drain is plugged.