Device for the smooth and flutter-free feeding of sheets on sheet-fed machines, particularly offset printing presses

A feed drum assembly for feeding sheets in succession to an impression cylinder of a lithographic printing press comprising, in combination, a rotatable core, a cylindrical mantle mounted on the core and having a substantially smooth surface which is concentric with the core, an axially and circumferentially distributed array of spacers spaced radially outward from the surface of the mantle at a constant spacing to define a sheet supporting locus, means for guiding a sheet onto and away from the sheet supporting locus so that the sheet makes only a partial turn about the drum, and axially extensive nozzle means stationarily mounted with respect to the drum and spaced outwardly therefrom for directing high velocity air chordwise of the drum and into the region between the sheet and the mantle, the change in direction of the air as it strikes and tends to follow the curved surface of the mantle serving to create suction upon the sheet drawing the sheet into contact with the array of spacers and thereby preventing fluttering of the sheet as it is passed to the impression cylinder.