Abstract: Printing-press roll cleaning method and apparatus. Washing liquid is applied only to discrete longitudinal wetting zones (52) on a roll to be cleaned, leaving longitudinal non-wetting zones (54) between them. During the rotation of the rolls, the washing liquid flows away to the longitudinal non-wetting zones (54).

Abstract: A printing cylinder cleaning device of a sheet-fed printing machine. A control-cam/cam-follower is provided for transferring a cleaning unit over and above a gripping means from one outer surface portion of an impression cylinder to another outer surface portion of the latter. For the run of the cam follower onto the control cam, the throw-on pressure of the cleaning unit is reduced. Thereafter, it is increased again for the run onto the outer surface of the impression cylinder.

Abstract: A cleaning apparatus for a surface, particularly for a surface in the graphics industry and more particularly for the surface of a cylinder used in the graphics industry. A pressing element has a cleaning cloth thereover. The pressing element is movable toward and away from the surface. A pressurizable pressure chamber which when pressurized acts on the pressing element to move the cloth to the surface. A pneumatic circuit feeds compressed air to the pressure chamber and vents the pressure chamber. The circuit includes a compressed air storage chamber which can be alternatively connected to the pressure chamber to pressurize the pressure chamber or to a compressed air source to refill the chamber with compressed air. The volume of the storage chamber and the pressure therein are higher than that of the pressure needed in the pressure chamber for rapid refilling of the pressure chamber.

Abstract: A sheet-cleaning apparatus for cleaning a sheet (6) that is to be printed, before it runs into the printing mechanism (2) of a sheet-fed printing press. A backing cloth (20), which is contacted with the sheet (6) that is to be printed with the help of the positioning means, is used to clean the sheet (6) that is to be printed. A transporting apparatus (26, 24, 28) transports the backing cloth (20), so that other moist sections (32) of the backing cloth (20) are consecutively brought into contact with the sheet (6) that is to be printed.