Patent GB-837481-A (GB)
Title: Improvements in or relating to printing
Inventor: MILLER ROBIN GORDON
IPC: B41F17/00
Filed: 1955-10-21
Abstract: 837,481. Printing. BRITISH UNITED SHOE MACHINERY CO. Ltd. Oct. 22, 1956 [Oct. 21, 1955], No. 30078/55. Class 100(2) In apparatus for decorating blanks of slightly varying size in the manufacture of articles of pottery, tiles, bricks or other ceramic ware, an extensible membrane which takes up the pattern from an inked design plate is carried by a supporting device which can be adjusted to stretch the membrane and so vary the size of the offset design thereon to suit the size of article to be decorated. As shown, apparatus for offset printing on ceramic plate blanks B in the "biscuit" state, comprises a base plate 10 having a vertical spindle 16 about which a horizontal triangular table 14 can swing, this table carrying an intaglio printing plate S and a support 18 for the blanks B. A bracket 28, mounted on a vertical shaft 30 which passes through a large arcuate slot 32 in the table 14, is adapted to be reciprocated vertically by means including a treadle, and carries a rod 34 having a flange 36 on which is an air-filled rubber cushion 40. A sleeve 38, slidable on the rod 34 against the action of a compression spring 39, carries two pivot pins on the ends of which are mounted four legs 44 which hang downwardly and carry a framework F on which a rubber transfer or offset membrane 58 is mounted. The framework consists of four rods 46 oppositely threaded at each end to engage nut devices 48, so that they form a square which can be increased or decreased in size by the operation of hand-wheels 50. The nut devices 48 are provided with ears to support four bars in a horizontal plane, and these carry the flexible and extensible rubber transfer membrane 58. Two of the rods 46 pass freely through bores in the lower ends of the legs 44. In use, assuming that the intaglio plate S is suitable for offset printing a pattern close to the top surface and adjacent the edge of ceramic plate blanks B of a particular diameter, the operator grasps a handle 20 on the table 14 and swings it to the left whereby inking apparatus (not shown) inks the plate S. He now swings the table back to the right to bring the table to operating station O, in which position a stop 22 on the table engages a fixed lug 26 on the plate 10. The treadle is now depressed to move downwardly the bracket 28 to cause in succession, the membrane 58 to engage the inked plate S, and the cushion 40 to press the membrane into intimate contact with the design. When the treadle is released, it is raised by a spring; the cushion 40 rises first, and then the membrane F. The operator now swings the table 14 to the left to bring the blank B to operating station O, in which position the fixed lug 26 engages a stop 24 on the table, and the plate S is re-inked by the inking apparatus. On the depression of the treadle, the inked design on the membrane 58 is transferred to the blank B. If the next blank B is of slightly smaller or larger diameter, immediately the membrane 58 has picked up the inked design from the plate S, the stretched membrane is adjusted by operating the handwheels 50 so that the size of the design thereon is adjusted to suit the size of blank. Stop collars on the rods 46 assist this adjustment. In modifications, the frame F can be adjusted by one hand-wheel 50 only. Further, the membrane 58 may transfer the pattern to a further suitablyshaped deformable pad, e.g. of gelatine, which then transfers the design to a blank B.