Patent GB-928737-A (GB)
Title: Improvements in or relating to printing
IPC: B41F11/00
Filed: 1960-07-27
Abstract: 928,737. Rotary printing presses. M. GLUECKERT. July 27, 1960 [July 27, 1959], No. 26166/60. Class 100 (2). A rotary printing-machine for both relief and offset printing comprising outer printing cylinders 1a, 1b and inner impression cylinders 2a, 2b, each of the cylinders 1a, 1b being operatively associated with the respective cylinder 2a, 2b, is characterized in that the two impression cylinders are in contact during offset printing and are separated during relief printing, the two printing cylinders maintaining the same distance from their respective associated impression cylinders when the cylinders 2a, 2b are separated and the cylinders 2a, 2b are utilizable as counter-pressure cylinders for relief printing. For offset printing the cylinders 2a, 2b are equipped with offset blankets whereas the cylinders la, 1b mount printing plates. Fig. 2 shows the cylinder pairs arranged for perfecting relief printing with the cylinders 2a, 2b carrying a facing of glass fibres or cork. The cylinder arrangements of Figs. 1 and 2 are mounted on a press having damping and inking systems 9a, 9b, Fig. 3. The damping systems are thrown out for relief printing. In a further embodiment, a rotary press has machines 12, 13 the former being set for relief printing on a paper web 7, Fig. 5, whilst the latter is arranged for offset printing on a second web 3, the printed sheets produced by both machines being combined by folding in a cutting and folding device 11. A single web of paper may be sequentially passed through this machine to produce two superimposed impressions for multi-colour work. Again, one machine may print one side of a single web by offset printing whilst the other machine relief prints on the other side. The cylinders 2a, 2b may be moved through eccentrically mounted bearings, rotation of outer eccentric bushing 15, Fig. 6, of which, through hand wheels 24, bevel gears and worm gearings 19, cause identical rotation of the bushings 15 such that the inner cylinders move radially towards or away from each other. Inner eccentric bushings 16 are arranged within the bushings 15 such that angular displacement thereof through radial arms 25, connecting links 26, double bell-crank levers 27 and a single adjustment handle will radially move the cylinder 2a or 2b toward and away from the corresponding cylinder 1a or 1b to vary contact pressure between the cylinders of each cylinder pair as desired. In further means for moving the cylinders 2a, 2b, swinging arms 35, 36 carrying the inner cylinder 2a, Figs. 9, 10, are mounted on the press frame 14<SP>1</SP> on bushings 37 enclosing the bearings at the two ends of the cylinder 1a. The arms are moved through actuation of a hand wheel 38 which rotates bevel gears 40, 41, screw spindles 42 in blocks 43 and hence threaded sleeves 44 hinged to the arms. In yet another arrangement the two pairs of cylinders are respectively mounted on a stationary portion 49, Figs. 11, 13, and on a movable portion 50 of the press frame, relative movement of the portions 49, 50 being effected through a hand wheel 51, a rotatable shaft 52, bevel gear 53, 54, spindles 55 and brackets 56, 57. As shown in Fig. 14 with regard to cylinder 1a, the outer cylinders are solid, each having face-plates 62 and an abutment ring 63. Stereotype printing plates 61 are clamped between the plates and ring 62, 63 by clamping screws 64 rotatably mounted in recesses formed in the cylinder body 60 and annular flanges 65 fastened to the body. Fig. 16 shows the same cylinder arranged to receive etched plates 67, for both relief and offset printing, which are secured by adhesive to packing 66, the latter being held by a plate and ring arrangement similar to that disclosed in Fig. 4. Similarly the cylinder may carry rubber printing plates adhesively mounted on a thin metal sheet which is mounted over packing by means of the tensioning device of Fig. 20. This device, comprising a longitudinally slotted rod 73 rotatable within a recess in the cylinder and carrying a spring-loaded clamping bar 76, is shown clamping an offset plate 72 of thin sheet metal around the cylinder over a packing 71. The packing is mounted through the plate and ring arrangement of Fig. 14. The other end of either the metal sheet carrying the rubber printing-plate or the plate 72 is clamped under the packing such as 71 in Fig. 20. A rubber offset blanket is secured to the surface of the cylinder 2a or 2b by reinforcing the edges of the blanket with metal strips 79, Fig. 21, prior to connecting them to a tightening device through insertion in slots 80 of rotatable rods 81, each of which is rotated through a worm wheel and worm arrangement 82, 83. Since the damping of a printing cylinder 1a or 1b is not required when the machine is used for relief printing the machine may have disengageable damping units one of which is shown in Fig. 22. Three rollers 9<SP>1</SP>, 9<SP>11</SP>, 9111 transmit damping liquid from a fountain (not shown) to the cylinder 1a. Rollers 9<SP>1</SP>, 9<SP>111 </SP>are mounted in retractable bearings 87 axially movably mounted in the machine frame. The roller 9<SP>1</SP> has an axially movable gear shown in its inoperative position 88 in fully drawn lines. The gear may be shifted to its operative position 88<SP>1</SP>, indicated in broken lines, by a handle 89 having an arresting device 90 to prevent accidental shifting of the gear 88. Rotary movement is transmitted in the operative condition of the damping units from the gear 47 of the cylinder 1a to the gear of the roller 9<SP>1</SP> in the position 88<SP>1</SP>, and therefrom to the gear 91 of the roller 9<SP>11</SP>. When the machine is to print by relief the gear of the roller 9<SP>1</SP> is shifted into the inoperative position 88, the corresponding bearing 87 is pulled outward, and the roller 9<SP>1</SP> is removed. No motion is transmitted from the cylinder 1a to the gear train of the damping mechanism. If desired, the roller 9111 may also be removed.