Patent attributes
A dishwasher includes a pump assembly which functions to chop all fluid entrained soil prior to directing fluid to upper and lower wash arms. A flow conduit leading to the upper wash arm is provided with a sampling port which directs a percentage of the fluid flow into a filter chamber having one or more fine mesh filter screens that open into the dishwasher tub basin. The filter chamber is exposed to a collection chamber that leads to a drain. In the event the filter chamber becomes clogged, a pressure relief valve opens a pressure regulation port to permit washing fluid in the filter chamber to enter the tub basin. In one embodiment, the pressure relief valve is constituted by a check ball which is displaced by a pressure build up in the filter chamber. In another embodiment, the pressure relief valve is constituted by a flapper valve.
