Abstract: In a vacuum cleaning system in which the top dome and receiving shell are separated by a screen, a screen cleaning system comprising an air knife having a coanda profile rotatably arranged in the dome adjacent the screen. The vacuum cleaning system is selectively actuated in accordance with a timed program to clean lint and debris from the screen.

Abstract: A vacuum cleaning arrangement having a collecting tank in which a jack system is arranged about its periphery which is operative to lift and separate an upper portion of the tank from a lower portion of the tank and also to move the upper and lower portions into contact under pressure. A filter screen is positioned between the upper and lower portions. The filter screen comprises a screen formed of metal wires and a perforated metal plate. A U-shaped resilient seal or gasket is secured about the outer surface of the plate. The arrangement provides that when the upper portion is drawn into contact with the lower portion, the portions engage the gasket with sufficient pressure to form an air-tight seal therebetween.