Patent GB-549304-A (GB)
Title: Machine for printing upon or coating curved surfaces
IPC: B41F17/22
Filed: 1941-05-12
Abstract: 549,304. Coating machines. CROWN CORK & SEAL CO., Inc. May 12, 1941, No. 6144. Convention date,. June 26, 1940. [Class 95] [Also in Group XVI] A machine for printing on or coating the curved surfaces of sheet metal cans, bottles, jars, tumblers, paper or cardboard cartons or tubes, collapsable lead tubes &c. comprises a rotatable turret carrying opposed pairs of chucks for rotatably supporting the articles and carrying them into rolling contact with rotary transfer printing or coating blankets. In one form of machine, Fig. 1, can bodies 11 are fed by gravity to a continuously rotating turret 12 having twelve pairs of chucks 13 and are carried thereby into contact with one or the other of two transfer printing blankets 15, 16 on a transfer cylinder 14 driven continuously at six times the speed of the turret so that each blanket prints on alternate cans. After printing the cans are released from the chucks and fall on to supports 21 on a delivery conveyer 22. Four printing cylinders 155 each with its own inking apparatus are arranged round the cylinder 14 to provide fourcolour impressions on each transfer blanket. The path of movement of the cans intersects the path of the blankets and the chucks are yieldingly mounted so that they move radially while the cans are in contact with the blankets. For coating instead of printing the cylinder 14 has an unbroken cylindrical transfer surface and the coating material applied thereto may be in a number of superposed layers or a number of separate bands. The path of the cans is such that each can makes several complete rotations while in contact with the blanket so that the finishing line of the coating is imperceptible. Driving arrangements. The main driving shaft 30 is driven from a motor 25 by a belt 27 and carries a pinion 32 meshing with a large gear 40 on the shaft 41 of the transfer cylinder 14. A pinion 33 on an axially movable hand-operable shaft 34 is normally held out of gear with the pinion 32 by a spring on the shaft but may be engaged therewith if it is desired to drive the machine by hand. Can-holding turret. The turret comprises side plates 61, 62, Fig. 12, having guide ways 66, 67, Fig. 1, for the chucks, each of which comprises a block 68 slidable in a guideway 66, 67 and normally pressed radially outwards into contact with a cap member 116 bridging the guide ways by a spring 115. A bracket 69 projecting from the block 68, and the block itself support a hollow freely rotatable spindle 73 provided with a cam-engaging head 97 having an external diameter equal to the diameter of the cam 11 and the heads are normally urged towards the cans by springs 82 engaging plugs 80 bearing against thrust bearings 81. Rollers 85 of the same diameter as the heads 97 are secured to the spindles 73 by cross-pins 87 passing through slots in the plugs 80 and have grooves 86 engaged by rollers on the forked ends of levers 90 pivoted to the brackets 69 and carrying rollers 91 co-operating with fixed cams 95 whereby the spindles 73 are at the correct times withdrawn to release the printed cans and allowed to move inwardly to grip the infed cans. Arcuate seat members 76 projecting inwardly from the blocks 68 are provided to receive the cans as they are fed into the turret and the cans are lifted from these seats when gripped by the heads 97 of the spindles. The rotation of the cans during the printing operation is effected by arcuate members 110 on the transfer cylinder engaging the heads 97 and rollers 85. In a modification, the two levers 90 are operatively connected together for actuation by a single fixed cam such as 95. Impression adjustments. Each printing roller shaft is mounted in an eccentric bearing sleeve having a projecting arm 251 to which is pivoted a pin 254 having a collar 255 fixed to its outer end. An externally threaded sleeve 256 having a head 257 by which it may be turned, is confined between the collar 255 and the head 252 of the pin and is threaded through a block 259 swivelled in the fixed frame. By turning the sleeve 256 in either direction, the eccentric bearing shaft may be turned to adjust the contact between the printing roller and transfer cylinder. The printing roller may also be adjusted circumferentially on its shaft and, for this purpose bolts 266 fixed to the end of the roller pass through arcuate slots in a plate 261 fixed to the end of the shaft. An adjusting device similar to the devices 254-257 is provided between one of the bolts 266 and a swivel block 272. Inking apparatus. Each inking apparatus comprises a fountain 166 having an opening in the front wall adjacent to a fountain roller 168 driven intermittently by ratchet mechanism and linkage from a cam on the shaft of the transfer cylinder. The thickness of the ink film on the roller 168 is adjusted by a wedge-shaped false bottom 196 on the bottom of the fountain, the false bottom being adjusted by a screw 199 and locked after adjustment by a screw 200. Ink is transferred from the roller 168 to . an inking cylinder 162 by a ductor roll 170 on arms 171 fixed to a rock shaft 172 to which is also secured an arm 235, Fig. 6a, actuated by linkage from a cam on to the shaft of the transfer cylinder. This linkage includes an adjustable connecting rod 232 resiliently connected to the arm 235 by a crosspin 234 engaged by opposed spring members 234 in the end of the arm 235. The ink cylinder 162 comprises a shell shrunk upon spiral ribs 164, Fig. 24, and hub member 163. As the cylinder rotates it induces a current of air through the hub between the ribs 164, thus preventing overheating of the cylinder. A pair of frame-inking rollers 175, Fig. 1, are mounted in eccentric bearings in the ends of arms 179 pivoted about the shaft of the ink cylinder and having slots 182 engaging bolts 181 for coarse adjustments of the rollers 175. Fine adjustment of the rollers may be effected by their eccentric bearings.