GB763571A - Improvements in inking devices for printing machines - Google Patents

Abstract

763,571. Inking-apparatus. HARRISON, W. Aug. 11, 1954 [Aug. 12, 1953], No. 22184/53. Class 100(2) A device for inking and cleaning intaglio printing plates consists of two doctorblades, 4, 5, Fig. 1, arranged at an angle to each other on a rockable shaft 1 by which they are brought alternately into contact with the plate with their planes at an acute angle thereto on opposite sides of a thread or body of ink lying within the angle and are moved in one direction to spread the ink and in the opposite direction to clean the ink off the flat unengraved portions of the plate, the blades being adjustable toward and away from the line of intersection of their respective planes whereby their rocking motion may be limited so as not to break contact with the body of ink on the plate. The bolts 14 securing the blades to their holder 6 may pass through slots extending downwards from the top edge of each blade to permit this adjustment. As shown in Fig. 5 the shaft 1 is mounted at each end in a bearing 2 which slides in a fixed slotted frame 3; between the bearings 2 and ends of the holder 6, the shaft 1 is engaged by bearings 7 of pushrods 9, Fig. 4, by which the device is reciprocated. Where separate end-extensions to the printing plate are provided for instorage, the blade asembly may be arranged so that the blade contact-lines are inclined to the transverse junctions of the end-extensions to assist passage thereover. Helical springs load the holder 6 so that rollers 11, Fig. 5, on levers 10 fixed to the shaft 1, are pressed on to cam bars 12 which may be set into raised or lowered position by slide-bars 8; with the bars 12 raised the blade 4 is adjusted to spread a thin layer of ink on the plate, while with the bars 12 lowered, the blade 5 is adjusted to clean the unengraved parts of the plate. The ink may be applied by gravity, pump, or compressed air feed direct to the printing plate from a container (or a distributer supplied from a separate reservoir) placed between the doctor blades and the plate, which latter may be horizontal, vertical, or upside down. The doctor blades may be of metal, such as hardened and tempered steel, or of cellulose- or amino-plastics, polystyrenes, polyacrylates, polyvinyl derivatives, etc; they may be resiliently mounted by means of helical springs on their shaft, or long flat, curved or comb-like backing springs. The Provisional Specification refers to the use of doctor blades both in the same plane, or a single double-edged blade; also to fluid-pressure or electrical devices to replace the parts 8, 10...12, and to a second doctor-blade assembly or scavenger to follow the first during the plate cleaning operation, with means to clean the bladeedges during their inoperative periods.