Patent GB-358517-A (GB)
Title: Improvements in printing machines
IPC: B41F9/00
Filed: 1930-07-08
Abstract: 358,517. Printing-machines. BARKER, R. W., 56, Ludgate Hill, London.- (American Bank Note Co. ; 70, Broad Street, New York, U.S.A.) July 8, 1930, No. 20676. Grant of Patent opposed. [Classes 100 (i) and 100 (ii).] Rotary intaglio machines; impression adjustments; printing-surfaces.-Relates to rotary steelplate printing-machines and consists in means for facilitating adjustment of the parts to accommodate plates of different lengths. The plate cylinder 12 is secured to its shaft 11, the outer end of which is reduced and carries rigidly a plate 18, Figs. 1 and 2, on the hub 19 of which is loosely mounted a main gear wheel 20. A stud 28 projects from the gear wheel between two spaced lugs 26, 27 on the plate 18 and is engaged by an adjusting-screw 29, the heads of which engage the lugs 26, 27. Rotation of the screw effects the adjustment of the cylinder relatively to the gear wheel in order to allow for the use of differently-sized plates on the cylinder. The degree of adjustment is shown on a scale 32 by a finger 31 on the lug 27. The relative positions of the gear wheel and cylinder are fixed by means of bolts 25 passing through slots in the plate 18 into the gear wheel. The impression cylinder or D-roll 22 is driven by friction during the printing operation, but means is provided for driving it positively while it is not in engagement with a plate. The impression cylinder is provided with a gear wheel adapted to mesh with a series of racks carried in an undercut groove in the gear wheel 20. As shown, two rack structures are provided for use with two printing-plates secured on the cylinder. The racks are held in place by plates 36, 37 adjustable on the gear wheel by means of bolts 39 and slots 38. The plates are secured to parts 34, 34a of the rack structures by bolts 36a, 37a, so that the parts 34, 34a move with the gear wheel and serve to drive the impression cylinder while its blanket is out of contact with the printing-plates on the cylinder 12. Springs 40, 40a connect the plates 36, 37 with floating rack-segments 35, 35a, so that, during the friction drive of the impression-cylinder, allowance can be made for variations in the speed of the impression cylinder due to irregularities in the plate or in the make ready. The plates 36, 37 carry blocks 45, 45a engaged by screws 44, 44a whose ends engage abutments on the gear wheel 20. Adjustment of the screws 44, 44a affects the positions of the plates 36, 37 and rack parts 34, 34a secured thereto and so enables the point of engagement of the printing-plate and the impression cylinder to be altered to compensate for slight differences in length of the plates. The plates are of certain standard sizes, the adjustment for plates of different standard size being effected by actuation of the screw 29, and slight variations in length between plates of the same standard size are compensated for by adjustment of the racks 34, 34a. The surface of the plate cylinder is provided with series of slots, the number of series varying according to the number of plates to be carried. The slots are spaced apart and are adapted to carry clips for holding plates of the different standard lengths with the front edges in approximately constant position. Sheet feed-tables.-The paper is arranged to be fed to the printing-couple by a reciprocatory table 23 actuated by cams on the gear wheel 20. The cams, which equal in number the number of printing-plates, are formed by plates 70, Fig. 6, mounted on seats 69 and each is provided with a recess forming spaced shoulders 76, 77 engaging the ends of a screw 79 working in a block 78 on the gear wheel. The cams are therefore adjustable to vary the time of feed of the paper sheet.