Abstract: A method of washing objects in a dishwasher having upper and lower spray arms within a wash chamber and a sump filter. Wash liquid entering a sump from the wash chamber to be recirculated by a pump is filtered the filter to prevent soils from entering the sump and being recirculated. When the lower spray arm is operating, wash liquid is directly sprayed onto the filter from a clean-out nozzle on the lower spray arm to clean soils off the filter and prevent the filter from clogging. During a pre-wash cycle and at least one pre-rinse cycle, wash liquid is continuously sprayed from only the lower spray arm to prevent the filter from clogging when heavy soils are removed. During a wash cycle and at least one rinse cycle, wash liquid is alternately sprayed from the lower spray arm and the upper spray arm when the heavy soils have already been removed and it is less likely the filter will become clogged.

Abstract: A washer for washing objects with liquid. The washer includes a wash chamber adapted for holding objects to be washed. The sump has a pump chamber and a collection chamber, both of which are adapted to hold liquid from the wash chamber. A recirculation pump is operable to move liquid from the pump chamber to the wash chamber. A drain pump is operable to move liquid from the pump chamber and the collection chamber to a drain. A rotatable blade is disposed in the collection chamber and is adapted to mince particles therein. A controller is provided for controlling the operation of the recirculation pump and the drain pump. The controller is operable to turn the drain pump on and off during a wash phase in order to move particles from the collection chamber to the drain. The controller is also operable to turn the drain pump on at the end of the wash phase in order to initiate a drain phase wherein the drain pump drains the sump of liquid.

Abstract: Disclosed is a filter standpipe for a dishwasher filter and sump unit that prevents loss of circulation pump prime due to filter blockage. The filter standpipe preferably comprises a weir tube that projects upwards from the upper surface of the filter to provide a bypass for wash water trapped on the upper surface of a blocked filter.

Abstract: A dishwasher is provided with a flapper valve for directing water from a recirculation pump to spray arms or a drain. The valve is spring biased toward a recirculate position and solenoid operated to a drain position. An inlet of the pump is provided with a downwardly curved suction pipe having a generally horizontal bell mouth. The dishwasher has a sump separated into a pump chamber and a collection chamber. The pump inlet is located in the pump chamber and has a mouth that is located below a level of the bottom of the collection chamber. Wash liquid is pumped through a venturi in the collection chamber to a drain.

Abstract: A dishwasher sump is divided into a collection chamber and a pump chamber by a filter. Food particles collect in the collection chamber while filtered wash liquid collects in the pump chamber. A pump has an inlet located in the pump chamber. The filtered wash liquid is recycled and sprayed on objects in the dishwasher by the pump. The impeller is driven by a shaft extending through the collection chamber and a wall separates the pump chamber from the collection chamber. Food particles in the collection chamber are minced by a rotating blade on the pump shaft. Balancing vanes on a rear face of the impeller prevent food particles and dirty water from flowing into the filtered liquid from the collection chamber. At the end of a wash cycle, the minced food particles are pumped to a drain with the wash liquid.

Abstract: A filter screen assembly is provided which includes a housing, a filter screen, and two valve or check balls. The housing has two interior walls, each having openings therein which divide an interior space of the housing into top, center, and bottom chambers. A first inlet and a first outlet open into the top chamber and a second inlet and a second outlet open into the bottom chamber. The filter screen is horizontally disposed within the center chamber. One check ball is located in the top chamber and is biased to close the first inlet by a bottom inclined surface of the top chamber. The check ball is forced to substantially close the first outlet when fluid flows in the first inlet. The other check ball is located in the bottom chamber and is biased to close the second inlet by a bottom inclined surface of the bottom chamber. The check ball is forced to substantially close the second outlet when fluid flows in the second inlet.

Abstract: A dishwasher sump is divided into a collection chamber and a pump chamber by a filter. Food particles collect in the collection chamber while filtered wash liquid collects in the pump chamber. A pump has an impeller located in the pump chamber. The filtered wash liquid is recycled and sprayed on objects in the dishwasher by the pump. The impeller is driven by a shaft extending through the collection chamber and a wall separating the pump chamber from the collection chamber. Food particles in the collection chamber are minced by a rotating blade on the pump shaft. Balancing vanes on a rear face of the impeller prevent food particles and dirty water from flowing into the filtered liquid from the collection chamber. At the end of a wash cycle, the minced food particles are pumped to a drain with the wash liquid.