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AssigneeMAN Roland Druckmaschinen AG
InventorsGeorg Hartung, Michael Rother
Estimating the term…
Method and apparatus for the varnishing and printing of sheets in a printing machine. A feed drum incorporates a counterpressure surface to form a first nip with an impression cylinder. As sheets are fed to the impression cylinder and transported through the first nip, a constant pressure at the first nip consistently transfers ink to a verso side of each sheet. Arranged thereafter, a varnishing cylinder supplied with a quantity of varnish contacts the impression cylinder creating a second nip. As the sheet passes through the second nip, the recto side of the sheet is coated with the varnish. The impression cylinder thus receives a constant pressure for transferring ink to the sheet independent of the pressure provided by the varnishing cylinder. Accordingly, even a partial or intermittent varnishing of the recto sheet side has no adverse effect on print quality, and the sheet does not have to be transferred from the impression cylinder to a separate varnishing unit.
An apparatus for printing to a verso printing side of a sheet on an impression cylinder and subsequently varnishing a recto printing side of the sheet while the sheet is on the impression cylinder, comprising:
The apparatus of claim i wherein the pressure provided by the counterpressure device on the impression cylinder is essentially constant as sheets are transported through said first nip.
A method of printing and varnishing sheets in a printing machine having a rotatable impression cylinder, a feed drum for transferring sheets to the impression cylinder and including a counterpressure section in pressure contact with the impression cylinder forming a first nip through which sheets must pass, and a rotatable varnishing cylinder in pressure contact with said impression cylinder forming a second nip through which sheets must pass, comprising the steps of:
Dependencies are inferred from the claim text.