GB761456A - Sheet-fed rotogravure machine for multicolour printing - Google Patents

Abstract

761,456. Rotary printing-machines SCHNELLPRESSENFABRIK KOENIG & BAUER AKT.-GES. Aug. 28, 1953 [April 9, 1953], No. 23880/53. Class 100(2) A multi-colour sheet-fed rotogravure machine has means for registering the sheets before passing them through each printing couple, the couples being disposed in line one behind the other on one side of a sheet-feeding apparatus, and one or more sheet reversing devices are included each adapted to be rendered operative or inoperative whereby it is possible to print sheets on one side or on both sides in several combinations according to the number of printing couples provided. For example, with five couples, a sheet may be printed : 1) on one side in five colours : 2) on one side in four colours and on the other in one colour : 3) on one side in three colours and on the other in two colours. The sheets are dried between each printing operation and are finally delivered by tape conveyers on to either of two piles, as shown. Sheets 2 are fed from a pile 1 on to a table 13 in overlapping relation where they are registered at the front and sides. A variable-speed drum 14 receives the sheets and delivers them to an impression cylinder 15 co-operating with a forme cylinder 16. An endless conveyer chain 17 first conveys the sheets through a drying chamber and then to a point adjacent an endless chain conveyer 18, Fig. 5. If the sheets are to be printed on the same side by the next couple, the sprocket 6 of the conveyer 17 drives the conveyer 18 in the direction of the arrow A, and the conveyer 18 takes the sheets from the conveyer 17 and deposits them in a conveyer belt 10 which feeds them over the table 23 of the next couple 25, 26. If, however, the sheets are to be printed on the reverse side, they are taken from the conveyer 17 by a gripper drum 3 which now drives the conveyer 18 in the direction of the arrow B, and the conveyer 18 takes the sheets from the drum 3, carries them around the sprockets 5a, then over the belt 10 in reversed condition. The sheets are deposited on the belt 10 with their front edges against an adjustable stop 34, and the belt then conveys them over the table 23 of the next couple 25, 26. A similar reversing conveyer and gripper drum device is arranged between each printing couple. The conveyer chains 18 are provided with two sets of sheet grippers 7, 8, which are used according to the direction of travel of the chains, and with spring-loaded adjustablymounted rollers 9 which roll over and press the sheets on the belt 10 when the grippers 7 or 8 are opened. The grippers are opened by an adjustably-mounted cam 12. A plate 35 supports the belt 10 and co-operates with the rollers 9. The chains 18 can be driven at variable speed to suit. the speed of the conveyer 17, and to deliver the sheets on the feed table at reduced speed. Supporting wires, tapes, rods &c. may be associated with the chains 18 to form a support for the sheets.