Patent GB-447592-A (GB)
Title: Improvements in or relating to multi-colour offset platen printing machines
IPC: B41F1/10
Filed: 1935-09-20
Abstract: 447,592. Printing-machines. DUBUIT, L. G., 62bis, Rue Sainte-Blaise, Paris. Sept. 20, 1935, Nos. 26143 and 26144. Convention dates, Sept. 24, 1934 and Aug. 6,1935. [Class 100 (ii)] Platen machines; inking - apparatus.-A machine for printing multi - colour impressions upon various articles, including cylindrical articles by offset printing is constructed as a platen machine in which impressions from blocks inked in different colours are printed on a flat surface covered with a pad of gelatine, and when impressions from all the blocks are obtained on the gelatine the article to be printed is pressed against or rolled over the multi-colour impression during the period in which a dwell is given to the pad. In the machines described three printing-blocks are used, and in the modification shown in Figs. 1 and 2, these blocks are carried by an intermittently rotated carrier 1 and the blocks are inked by different sections of divided inking- rollers 14, 15, which receive their ink from intermittently rotating discs 16<a>, 16b, 16<c>. In the modification, Fig. 6, the gelatine covered plate 56 is rotated intermittently, and the printing-blocks are fixed in position relatively to a swinging carrier 43 which remains in a vertical position while the inking-rollers 72, 73 move over the blocks, and the carrier is moved about a pivot 46 on to the plate 56 so as to print simultaneously impressions from the three blocks on to the plate 56. In the first modification, the gelatine pad 8 is carried by an oscillating platen 7 pivoted at 6 to the base 2 of the machine, and operated by a cam 13 and a spring-controlled link 9 with a roller 11 pressed against the cam and controlled by a guide 12. The cam 13 is shaped to cause the platen 7 to make three short strokes to and from the carrier 1 so as to receive in succession an impression from each of the blocks 5<a>, 5<b>, 5<c> mounted on a carrier 1. The cam 13 then permits the platen 7 to move further from the carrier 1 and in this open position the operator moves the article to be printed into contact with the multi-colour impression on the gelatine pad and the impression is transferred to the article. When the platen moves to its open position the inking-rollers 14, 15 traverse the printing-blocks, the rollers being mounted in pivoted rods 19 which are connected by rods 21 to the platen. The carrier 1 is rotated intermittently by means of a bevel gear 26 which is driven by sprocket gearing from the cam shaft 33, and is freely mounted on the pivot 25 of the carrier 1 to which it is connected by a spiral spring 27. This spring rotates the pivot 25 in its ball bearings 3, 4 when a spring-controlled bolt 34 permits, the bolt being capable of engaging apertures 36<a>, 36<b>, 36<c>, in the carrier corresponding to the positions in which the blocks 5<b>, 5<c>, 5a, respectively register with the pad 8. The bolt 34 is released automatically by mechanism operated by the rods 19, and after one aperture is released from the bolt the mechanism is restored to normal position in time for the bolt to engage the next aperture. In Fig. 6 the plate 56 is rotated intermittently by gears 60, 61 operated by a ratchet wheel 120 actuated by a pawl 121 on a curved lever 122 oscillated by a link 123 and a lever 124 pivoted' at 112 and fitted with a roller 125. A double cam splined to the cam shaft 69 can be set so as to cause either of two cam surfaces to engage the roller 125, and the shaft 57 of the platen 56 is rotated a quarter or a half revolution. The plate 56 is held in its adjusted position by a locking pawl which is actuated by a lever and a link 37 from a cam on the shaft 69. The inking-rollers 72, 73 are moved to-and-fro over the blocks 54<a>, 54<b>, 54<c>, Fig. 7, by means of a cam 145 on the shaft 69 acting on a roller 144 on a fork 143 connected by a lever 142 to the shaft 78 of the arms carrying the rollers 72, 73. By link-mechanism the oscillation of the shaft 78 is transmitted to a messenger roller 90 which carries stripes of ink from a duct roller 91 in a divided ink trough 92 to a roller 95 coacting with distributing rollers 146, 147, 74. A pawl 93 carried by the messenger roller rotates the duct roller intermittently. The block carrier 43 is moved from its vertical position shown on to the plate 56 by means of a lever 111 pivoted at 112 and fitted with rollers 116, 117 engaged by cams 118, 119 on the shaft 69. The carrier 43 is pivoted by means of a sleeve 46 to pointed screw journals, and a fork 48 integral with the sleeve is connected to a link 49 connected to the lever 111. At each actuation of the carrier 43 prints from the three blocks are impressed on the plate 56, which is rotated a quarter turn after receiving the three impressions. At each actuation therefore one impression consisting of three superposed colours is obtained on the plate which also has received one two-colour and one single-colour impression. During the dwell of the plate 56 the operator presses the article to be printed into contact with the three-colour impression which is thus transferred to the article. When the plate 56 is set to rotate through half a revolution at each actuation of the carrier 43, only two printing-blocks are used and a two-colour impression is obtained at each actuation.