GB1294640A - Improvements in or relating to apparatus for controlling a multi-colour rotary printing machine - Google Patents

Abstract

1294640 Controlling printing machines POLYGRAPH LEIPZIG KOMBINAT FUR OLYGRAPHISCHE MASCHINEN-UND AUSRUSTUNGEN VEB 23 Sept 1971 44425/71 Heading B6C A multi-colour sheet fed offset rotary printing machine is controlled by a device utilizing a shift register and interrogation units. In the machine shown a feeding cylinder 4, Fig. 1, passes a copy sheet 2 to the impression cylinder 5 of a first printing unit and then via a transfer cylinder 6 to an impression cylinder 5<SP>1</SP> of the following printing unit. During periods when no sheet is present between the offset cylinder 10 and the cylinder 5 displacement means associated with the first printing unit are operated to cause the inking rollers 8 to be separated from a plate cylinder 9, the cylinder 9 to be separated from the cylinder 10 and the cylinder 10 to be separated from the cylinder 5. At the moment when a sheet reaches the contact point between cylinders 5 and 10 both cylinders have to be placed into their respective operating positions and, prior to this movement of the cylinders, the inking rollers 8 have to be placed into contact with the cylinder 9 and the latter into contact with the cylinder 10. Then displacements of the individual cylinders in each printing unit are controlled independently of each other and independently of the corresponding displacements of cylinders in other printing units of the machine. The displacements of the cylinders in each of the individual printing units are, so controlled by apparatus embodying the invention that these displacements take place in a predetermined sequence. A block-schematic diagram of one such apparatus is shown in Fig. 2 and comprises a shift register 11, interrogation units 12 and a control checking unit 27 for reducing operating speed after the last sheet has passed through the printing machine.