GB111078A - Improvements relating to Rotary Multi-colour Printing Machines. - Google Patents

Abstract

111,078. Damare, L. Nov. 7, 1916, [Convention date]. Rotary machines; offset machines; inking-apparatus; damping-apparatus for lithographic and like machines; set-off, preventing.-A rotary offset printing-press for printing in several colours and capable of printing either typographically or lithographically is constructed so that two different multi-colour designs may be printed, one alternating with the other on a web, and, after cutting of the web into sheets, the sheets bearing the same design are automatically sorted and deposited on separate tables. The press may also print cut sheets and, for this purpose is provided with a feed board. As shown in Fig. 1, four offset cylinders 2, 3, 4, 5 are arranged round a single impression cylinder 1 and in contact with plate cylinders 6, 7, 8, 9 respectively. The cylinders have semicircular plate or blanket-bearing surfaces so that, by providing plates bearing one design on one half of the plate cylinders, and plates bearing a different design on the other half, two different multi-colour designs may be printed on the web 12. After printing, the web is cut into sheets by a cutting-device 16 and the cut sheets are delivered by tapes 17 on to a table 18 which is continually oscillated on a pivot 19 to deliver the sheets alternately on to two tables thereby sorting the sheets bearing one design from those bearing the other. The inking-apparatus of each plate cylinder is mounted upon a slidable carriage 24 operable by rack and pinion gear 26, 27 so that any of the inking-apparatus may be thrown out of operation when desired. The ink is transferred from the duct roller to a distributing cylinder 29 by a vibrator roller and is transferred from the cylinder 29 to an inking-drum 28 by a number of intermediate rollers 30 which may be tripped by hand-operated lever mechanism when desired to vary the amount of ink supplied to the drum 28. The plate cylinders are provided with damping-apparatus 38 which may be moved clear of the cylinder when printing from typographic plates. To dry the impressions, a powder-applying device is arranged between each pair of offset cylinders and comprises powder-applying rollers 42 supplied with powder by a roller 45 partly immersed in powder in a trough 41. Excess powder is removed by spring- carried brushes 46. The powder may comprise a mixture of manganese dioxide, talc, and zinc oxide and may be tinted with a colour similar to that of the impression it is employed to dry.