GB763572A - Improvements in machines for offset printing - Google Patents

Abstract

763,572. Printing machines. HARRISON, W. Jan. 5, 1955 [Jan. 6, 1954; Aug. 11, 1954], Nos. 317/54 and 23298/54. Class 100(2) A machine for printing on articles having iregular surfaces comprises two or more elastic pads mounted on a rotatable frame and movable alternatively into contact with inked design-carrying, surfaces, e.g. plates and with articles to be printed. As shown, in Fig. 1, the frame 9 is rotatably mounted on a vertically reciprocable shaft 5 projecting upwardly through the surface of a table 1, and is located in four positions at right angles by a rib 7 on a collar 6 on the shaft engaging in notches 8 in a collar fixed to the frame. The lower end of the shaft is connected to a pneumatically operated piston in cylinder 11. The shaft may alternatively be reciprocated by other mechanical, electrical or manual means. Equally spaced around a circle concentric with the shaft 5 are design plates 3 and carriers 4 for the articles to be printed. The design plates are etched or intaglio plates e.g. metal or glass or the design surface may be carried on cylinders of a rigid material on sheets or bands of a flexible material as described in Specification 784,412. The machine may be used for single or multicolour printing. For single colour the pads are brought down on to the design plates, the frame is turned through 90 degrees .and the pads brought down on to the articles to be printed. The frame is then turned back to the initial position and fresh aricles positioned on the carriers 4 before the operation is repeated.. For multicolour printing the design plates 3 are inked in different colours and after the first printing operation as before, the pads are brought back to the initial position'reinked from the design plates and rotated 90 degrees in the opposite direction to print the articles in the second colour. Instead of having two design plates and two article carriers, arrangements are described using only one or three. The pads may be solid or hollow and filled with gases, fluids or flexible jellies. Alternatively a slab, sheet or film of elastic material may be used, being alternately forced by the pad against the inked design plate and the article to be printed. Instead of being mounted to move in a horizontal plane the pads may move in a verticle plane. In this case the pads are mounted on radial sliders for movement into and out of contact with the design plates and the articles to be printed. Opposite pads may be mounted on a diametrical rod so that when an article is brought into contact with a pad at one end, the pad at the other end,is forced into engagement with the design plate. Specifications 23009/03 [Class 100] and 763,571 also are referred to.