GB391461A - Improvements in rotary photogravure multi-colour printing machines - Google Patents

Abstract

391,461. Printing- machines. GREAVES, W., The Woodlands Shadwell, near Leeds. Oct. 28, 1931, No. 29892. [Class 100 (ii).] A rotary photogravure printing-machine of the kind in which a number of printing-couples are employed for printing in succession on a web, and in which one or more of the couples is reversible to enable the impression from any couple to be printed on the desired side of the web, is constructed with a common drive shaft 11 for the cutting-cylinder 13 and all the printing-cylinders 4, and a right-hand threaded worm 12, or a left-hand threaded worm 12a is provided for each worm wheel 13 on the cylinders, and either worm can be put into action according to the direction in which it is desired to drive the couple. The printing - plates o n the cylinders 4 are inked by means of rollers 5, Figs. 3 and 5, immersed in troughs 6, and are wiped by means of reciprocating scrapers 7, and the whole inking-apparatus can be adapted to an alteration in the direction of rotation of the cylinder 4, and also to co-operate with printing-cylinders of different sizes. The troughs 6 and rollers 5 can be supported on either side of the cylinders 4, and each roller 5 is driven from a gear 15 on the shaft of its cylinder 4 and intermediate gears 17, 18 and a gear 16 on the roller 5. The gears 17, 18 are mounted in a pivoted bracket 19 which can be secured on either side of the cylinder, and can be adjusted about the axis of the roller 17 so as to enable cylinders of different sizes to be employed. A screw 21 passing through a slot 22 holds the bracket 19 in the desired angular position. The scrapers 7 are attached to bars 23 secured to blocks 24 adjustably secured by screws 25 to the side frames of the machine. The scrapers are all vibrated by eccentrics on a shaft 26 and the eccentrics are adjustable axially of the shaft so as to act when the scrapers are on either side of the cylinder. The scrapers are detachably connected by swivels to the eccentric mechanism so tha't they can be tutned end-to-end when changed from one side of the cylinder to the other. The web 31 is led over freely mounted guide rollers 32 arranged at such distance apart as to enable the impression to dry before a subsequent impression is applied, and is registered and rolled as described in Specification 391,465. Each printing- cylinder 4 is mounted so that it can be adjusted laterally. The cylinder is splined to a sleeve 43, Fig. 5, secured to the worm wheel 13, and lateral motion of the cylinder is effected by a shouldered bolt 44 screwed into the end of the mandrel and held against lateral movement by a collar engaging at opposite sides of a boss on the wheel 13. The printed web is fed to the cutting-mechanism E by means of a roller 45 driven from the shaft of the cutting-cylinder through a slipping clutch which avoids the necessity of adjusting the cutting-cylinder to accommodate different lengths of sheets.