Patent GB-423196-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41F9/02
Filed: 1933-08-31
Abstract: 423,196. Printing-machines. STEVENS, A. H., 5, Quality Court, Chancery Lane, London.-(Shellmar Products Co. ; 3501, West 48th Place, Chicago, U.S.A.) Aug. 31, 1933, No. 24195. [Classes 100 (i) and 100 (ii)] A rotary intaglio printing-machine which is especially applicable for printing on transparent cellulose sheeting in multi-colours is constructed with a number of adjustable printing- units, with web-guiding means for directing the web therethrough, and means positional closely adjacent each printing-unit for drying the printed web. The web-feeding means includes rollers which engage the web over relatively closely spaced transverse lines of contact both before receiving the first impression and between successive impressions. The web to be printed is led from one of two rolls 30, 31, mounted on shafts 28, 29, fitted with brakes, over guide rolls 54, 55, 56 to a web-controlling rollers formed of steel rollers 33, 34, 35, 3 with which co-operate adjustably mounted rubber rollers 40, 38, 46 the pressure of which on the steel rollers is controlled by slides operated by screw mechanism with operating handwheels 45, 53, Fig. 2. The web rolls, and guiding rolls are mounted in frames 15 which are adjustable longitudinally along fixed base racks 13 by means of pinions which engage the rocks and are operated by bevel gearing from a hand-wheel 21. The printing- couples are mounted at each end in frames 58 which are similarly adjustable longitudinally along the racks 13, and the couples are driven from a square shaft 25 to which are splined bevel pinions 74 which drive vertical shafts 72 geared to the printing-rollers 63. Further, to ensure complete registration of the impressions the rollers 63 are mounted so as to be capable of transverse adjustment by means of screws 64, Fig. 5, operated by hand-wheels 65. The ink trough 77 in which each roller 63 dips is mounted so as to be adjustable transversely with the roller 63, and the driving-means between the shaft 72 and the roller 63 includes a tongue 67 which can move in a slot 66 connected to the shaft 62 of the roller 63. The web passes from roller 36 under a roller 124 arranged at a slightly higher level than the impression roller 120 which is mounted at each end in a pivoted frame 122 mounted on pivots 123 carried by slides which are vertically adjustable in frames 98 which are normally arranged in the position shown by full lines in Fig. 2. By means of worm gearing operated by a handwheel 107 the frames 98 can be moved to the position indicated by dotted lines to permit of access to the cylinder 63, Adjustable counter pressure rollers 127 are mounted in screwoperated vertical slides above the impression roller 120, and by means of these the printing pressure may be varied. Near the printing- rollers 63 are mounted drying-rollers 136 which are carried by short swing arms 135 so that the impression is dried almost immediately after being printed, and with the lacquer inks employed improved results are stated to be obtained. The rollers 136 are preferably cylindrical shells rotating on electrically heated cores. The pivotal mounting permits the rollers to be raised out of contact with the web as soon as the press stops. From the printing-units the web passes over a curved bank of idler rolls 137 supported by pivoted frames 138 which can be adjustable about pivots 139. A more positive contact of the web with the rolls is obtained than when a straight bank of rolls is used. After the final impression the web is led to cutting-cylinders, or, to a re-winding spindle 166 by means of guide-rollers 146 and a pair of positively driven feed rollers 154, 155. The diameter of the driving-roller 154 is a multiple of the diameter of the printing-cylinders, and it is mounted in a pivoted frame so as to permit of rollers 154 of different diameters being used. The roller 154 is driven by change-speed gear and worm gearing from a vertical shaft 156 geared to shaft 75. Inking-mechanism.-Each roller 63 rotates in a trough 77, and is wiped by a scraper blade secured to blocks 78, Fig. 5, attached to a holder 78 which is secured to a support 80 by means of hand clamps 81. The support 80 is carried by pivots 82 which are adjustable vertically by screw-mechanism operated by bevel-gearing and a hand-wheel 91. When access to the cylinder 63 is required the bearings of the pivots 82 are lowered by the wheel 91 and the doctor is moved about the pivots. To enable the doctor to be returned to its normal position a stop is provided by means of which it is ensured that the bearings of the pivots 82 are always returned to a constant position.