Patent GB-363035-A (GB)
Title: Improvements in or relating to printing cylinders
IPC: B41F27/12
Filed: 1930-10-15
Abstract: 363,035. Printing-cylinders. ROBINSON, L. T. A., 5, Arundel Street, Strand, London. Oct. 15, 1930, No. 30884. [Class 100 (ii).] In a printing- cylinder which is split longitudinally into at least two segments, the ends of a design sheet extend inwardly of and between the separating faces of the cylinder segments and are subjected to deformation therebetween so as to tension the design sheet on superimposition of the segments on each other. A cylinder comprising two segments has provided on the segment 2, Fig. 2, a central rectangular projection 5 and two projections 6, 7 of arcuate convex form which enter corresponding recesses 16, 8, and 9 respectively in the segment 1 and which extend the full length of the separating face 4. A design sheet 14 overlies the segment I and is arranged with its ends 19, 20 between the segments, each end having holes 21 which may be formed as tubular projections having flanges 28, Fig. 4, which may be clinched against strips 21<1> provided at the ends of the design sheet. The segment 2 is recessed and.provided with inserts 24, 25 and the segment 1 is provided with pins 26, 27 which engage the holes 21 in the design sheet and then engage recesses 31, 32 in the ends of spring- pressed plungers 33, 34 which are provided in recesses in the segment and guided by the inserts 24, 25. When assembling the cylinder segments the holes 21 are engaged by the pins 26, 27 and pressure is applied to the segments so as to force the ends of the design sheet into their respective recesses 8, 9 by the projections 6, 7; 'this gives the necessary tension to the design sheet and the cylinder segments may then be retained in assembled position by end rings. The rectangular projection 5 is provided with cross-pins 40 which engage in recesses 41 at each end of the segment 1 to limit the drop of the segment 2. The recesses are approximately L-shaped, starting from the separating face of the segment 1 and finishing at the end so that a lateral movement of the segment 1 in either direction will disengage the segments. In a modification the projections for deforming the design plate are V-shaped and the spring- pressed plungers are prevented from leaving their recesses by cover-plates. The top of the central rectangular projection is provided with set-screws which engage in a recess in the other segment, the recess being covered by bars at each side so that the segments cannot be disengaged by reason of the heads of the set-screws engaging the cover bars. In another modification shown in Fig. 5, the two side projections comprise half-round bars 45, 46 disposed in recesses in the segment 2, and the ends 19, 20 of the design sheet are gripped between wedge-shaped bars 49, 50 and the undercut or slightly bevelled sides 51, 52 of the recesses 53, 54 formed in segment 1. The wedge-shaped bars 49, 50 may be integral with the segment 2. The central rectangular projection may be replaced by a rectangular shaft to which the cylinder segment 2 may be secured by screws &c. Journals for the cylinder may be integral with the segments. Each segment may be a casting of built-up or the same or different metals. The design sheet may be carried by either segment, or may be superimposed round both segments, or two design sheets may be used one on each segment. A filling material 66 which may be constructed as described and claimed in Specification 362,983 is inserted between the longitudinal joints of the segments.