GB478401A - Improvements in offset printing - Google Patents

Abstract

478,401. Printing machines. OXVAR, Ltd. (Oxford Varnish Corporation) Feb. 23, 1937, No. 5486. [Class 100 (ii)] A printing-machine for printing designs in multicolour, or for graining, comprises a pair of travelling offset rollers 40, 40a, Fig. 1, which are moved by means of handles 48 over a bed 20 fitted with printing- surfaces 50 and then over the work W carried by supports on a bed 30. The rollers are fitted with gears 44 which engage racks 47 on the beds, and with adjacent bearers 45 engaging rails 46. The beds 20, 30 are of wood, and are mounted within wooden frames comprising members 12, 13, 14 connected together by dowels. The beds are mounted so as to be capable of vertical adjustment, on sliding wedges 22 arranged below wedges 23 fixed to the beds. The wedges 22 are operated by screw-and-nut mechanism actuated by bevel gearing from shafts 31, which thus enable the printing pressure to be controlled. A pair of brackets 60 supports the rollers 40, 40a when not in use. The roller 40 collects one part A of a complete design from one printing-bed 50, and the roller 40a collects and prints the complementary part B of the design. Designs in which superposed impressions are obtained may be printed by the rollers 40, 40a. The process may be so arranged that the first part of a design is printed in an ink which dries quickly, so that the first impression may dry before a subsequent impression is applied. The printing-surfaces of the work holders are mounted so as to be capable of longitudinal adjustment for registration purposes.