Man Roland Druckmaschinen Ag

Friedrich Preuss

Harry M Greiner

A varnishing assembly in a printing press for applying a layer of varnish to a sheet on a press cylinder. The assembly includes a varnish fountain made up of a tray and fountain roller with an applicator roller interposed between the fountain roller and the cylinder. Storage tanks are respectively provided for varnish, fresh detergent and used detergent. The tray is equipped with an outlet line and an inlet line for drainage and filling. The outlet line has a two-position shut-off valve and the inlet line has a pump and pump drive motor. A two-position, three-connection drain valve is provided having an inlet connected to the outlet line of the tray end outlets connected to the varnish tank and the used detergent tank. The system also includes a two-position, three-connection fill valve having inlets connected to the varnish tank and the fresh detergent tank and an outlet connected to the tray inlet line. Means are provided for switching the valves and motor to produce a cleaning cycle in which (a) varnish is drained from the tray into the varnish tank, (b) fresh detergent is pumped to the tray from the fresh detergent tank for cleaning up the residual varnish, (c) the used detergent is drained from the tray into the used detergent tank. The drained varnish is subsequently pumped from the varnish tank to the tray for resumption of varnishing.

Varnishing assembly in a printing press having self-cleaning feature

A mechanism for sorting sheets from a printing press to assure proper color density and to assist in making corrective adjustment which includes a main conveyor for normally conducting sheets to a main delivery pile and having a transfer station. An auxiliary conveyor extends from the transfer station to an auxiliary delivery pile. A scanning device is arranged upstream of the main conveyor for responding to the color density of the printed image on a passing sheet. A comparator produces a control signal when the color density is above or below tolerance, signifying a sub-quality sheet. Mechanism at the transfer station is triggered by the control signal so that the sub-quality sheet is diverted to the auxiliary conveyor for depositing on the auxiliary pile. The mechanism not only accomplishes sorting but the fact of diversion and the observed rate of diversion provides constant instruction to the pressman as to the necessity for, and the degree of, a corrective change in ink feed rate.

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Sprendlingen, Germany

Friedrich Preuss