GB748412A - Improvements in machines for off-set printing of articles having curved or irregular surfaces - Google Patents

Abstract

748,412. Printing with flexible surfaces. HARRISON, W. May 11, 1954 [May 12, 1953], No. 13163/53. Class 100 (2). A machine for printing articles having curved or irregular shaped surfaces comprises a suitably shaped elastic pad 5 attached to a vertically movable support 4, means for moving a design plate cylinder or band from which the print is to be taken, horizontally into a position directly under the pad and a vertically movable holder 6 for supporting for the article to be printed. The support 4 is guided on parallel rods 2 which also serve to guide the holder 6 during its vertical movement. The support 4 and holder 6 are displaced vertically by cylinders 8, 9 actuated by air pressure. The design plates 17 are supported on sliders 13 adapted to run on horizontal rails 7. For multi-colour printing a series of such sliders, each having a design plate, may be mounted in a rack which is displaced vertically or horizontally between printing operations to position each slider in turn in alignment with rails 7. A T-headed control rod may engage a shaped slot in each slider in the aligned position for displacing it to the position where the design plate is vertically under the pad. The pad is lowered to take an ink impression of the design plate which is then moved out of the transfer position. The pad is then lowered again into engagement with the article, and deforms to fit the surface to be printed. The pad is then cleaned by contact with an absorbent sheet if necessary and the process repeated with the next colour. The printing surface of the design plates may be intaglio, lithographic or a relief printing surface. In all cases they may be inked with a flexible roller. In the case of an intaglio plate a doctor blade is arranged to wipe over the printing surface to remove excess ink and to confine the ink to the engraved parts. Alternatively the ink may be applied by another doctor blade. The design may be engraved or etched on the surface of a cylinder or on a flexible sheet or band which may be fixed to the surface of a cylinder or used in continuous form passing over cylinders at each end and lying over the surface of the slide plate. The cylinder or band is moved to ink the design and co-operates with a doctor blade to remove excess ink. The slider conveying the cylinder or band is moved to bring the inked design under the pad as before. The elastic pad may be solid and of natural or synthetic rubber, or gelatine jelly. It may alternatively be hollow and shaped by fluid pressure, the walls of the pad being strengthened or controlled in shape by canvas or the like. Specification 23009/03, [Class 100], is referred to.