Abstract: A method for operating an automatic dishwasher in a manner to minimize the deposition of contaminants or filming on the dishes is provided. The present invention contemplates that objectionable filming on washed dishes or dishware items may occur if residual water left on the dishes at the end of the final drain step is not given a chance to drip off or drain from the dishware. The present invention provides for a drip period following the final drain step in the dishwashing cycle. The drip period provides an opportunity for gravity assisted draining or "drip-off" of residual water from the dishware items prior to evaporation such that the minute particles which are suspended in the residual water are not deposited onto the dishes. During the drip period, rapid evaporation of residual liquid from the dishware items is prevented.

Abstract: The drain filter has large inlet openings at a raised position and small inlet openings at its bottom, all shaped to cooperate with the dishwashing machine sump to form labyrinthine drainage passageways to stop debris exceeding an acceptable size. The drain filter is in two parts, a fixed portion and a removable portion, both of which provide these features. The large inlet openings into the removable portion of the drain filter are upwardly facing and on the downstream side of an elevated wall which forms a dam to stop dense objects from entering the filter. The total filter inlet area is small to maintain a high flow velocity to float softer and lighter items over the dam for removal from the dishwasher when it is drained. The small inlet openings drain the remaining fluid after the level falls below the large openings.

Abstract: A rotating spray arm is supported by a removable and vertically adjustable upper rack of a dishwasher. The fluid coupling for the spray arm is not affected by changes in the upper rack vertical position. The spray arm is also protected by a guard which forms a stand for the rack when removed from the dishwasher.

Abstract: Dishwasher pumping and filtering system provides for recirculation of filtered liquid in the form of either washing solution or rinse water, coupled with outside water-jet impingement flushing of filtered food particles from the filtering system and down a drain at the end of a washing or rinsing period while draining the liquid from the dishwasher.