Patent ID: 7621284

Claim:
A dishwasher comprising: a tub having a bottom and a plurality of side walls that collectively define a wash chamber, said wash chamber establishing a sump; a pump fluidly connected to the sump for establishing a flow of washing fluid in the wash chamber; a drain line fluidly connected to the sump for selectively discharging washing fluid from the wash chamber, said drain line including a drain loop that establishes a pressure head; a drain pump fluidly connected to the sump through a drain passage, said drain pump performing a purging operation to withdraw fluid from the tub during a wash cycle; and a filter chamber provided on the tub for filtering washing fluid and collecting particles, said filter chamber including a first drain port leading to the drain pump and a second drain port in direct fluid communication with the drain line, said drain passage, the first drain port and the second drain port being fluidly arranged in parallel, wherein a pressure build-up in the filter chamber that exceeds the pressure head automatically triggers a siphoning action that draws washing fluid and particles from a lower portion of the filter chamber through the second drain port and into the drain line while bypassing the drain pump.