Patent GB-617971-A (GB)
Title: Inking mechanism for printing machines
IPC: B41F31/08
Filed: 1946-01-16
Abstract: 617,971. Inking and damping apparatus. HOE & CO., Ltd., R. Jan. 16, 1946, No. 1519. Convention date, Jan. 16, 1945. [Class 100(ii)] In inking-mechanism for newspaper printing- machines, of the type comprising an ink rail 18, Figs. 1 and 9, which has a discharge surface shaped to curve about the periphery of a distribution cylinder 13 and carries ink pumps delivering ink to outlets 31 in the surface, the latter is formed by a component mounted on the rail for adjustment tangentially to the periphery of the cylinder so that the curved surface can be set to bring it closer at one side than at the other according to the direction of rotation of the cylinder, the rail being adjustable towards and from the cylinder. The apparatus may also be used for damping printing-plates in lithographic machines. As shown, each outlet 31 comprises two separate members 138, 139 spaced by a distance plate 146 and secured together by screws 145, semi-circular grooves 147, 148 in the members together forming a port in line with the end of a supply tube 32. The members 138, 139 are adjustable tangentially by loosening one or two screws 149, 151 and tightening the other. During the adjustment, the members ride on a tongue 154 formed on the rail 18 which is secured to a bracket 21 supporting pump mechanism 22, the unit being vertically slidable on a guide 12 and adjustable by admitting fluid to each of a pair of cylinders 131, the plunger 134 of which is fixed to a rod 135 having a shoulder 137 engaging a spring 136 whereby the rail is resiliently supported. To equalise the pressure at the two ends of the rail, a rack 141 is secured to each end, the two racks engaging pinions 144 one on each end of a shaft 143. The pumping- mechanism comprises a number of plungers 75, Fig. 2, one for each pipe 32, reciprocated in a block 64 by means of a reciprocating bar 76 actuated from a rotary shaft 87 by eccentric rods 89. The bar 76 engages collars 77 on the plungers 75, the stroke of each plunger being independently adjusted by turning a screw 92 to adjust a stop for varying the point at which the plunger is arrested under the action of a returning-spring 78. Associated with each plunger is an inlet valve 67 and an outlet valve 73, the ink being supplied at a pressure sufficient to keep the inlet valve open and the pump providing the extra pressure necessary to open the outlet valve. Any outlet valve can be opened at will to clear air locks or augment the ink-supply without disturbing the pump adjustment, by operating a pushrod 92a to cause the end of the plunger to engage the valve 73. A colour-selector 29 is provided, having five inlet pipes 44-48, Fig. 5, any one of which can be put into communication with the interior 58 of one of four conical valves 55 through one of five ports according to the angularly-adjusted position of the valves: the ink flows into an annular passage 62 communicating with an outlet 35, Fig. 1, connected by a pipe 28 to an inlet 34. The pipes 44-47 are for four different colours, and each valve 55 controls the supply to a group of eight inlets 34 corresponding to a rail section supplying a page of a newspaper; the fifth pipe 48 supplies cleaning fluid or compressed air to blow out the ink passages. The pump mechanism 22 is driven from the printing-machine through a disengagable clutch 107. In a modification, Fig. 7 (not shown), the pump mechanism can be connected up to a separate motor to drive the pump without running the machine. A cover 23 for the pump mechanism 22 is under spring pressure to prevent ink leakage. The pump plungers 75, Fig. 2, are lubricated from oil-supply pipes 95 connected to bores 93, the oil pressure exceeding the ink pressure to prevent escape of ink past the plungers. The colour-selector mechanism forms the subject-matter of Specification 618,042. The Specification, as open to inspection under Sect. 91, states that the apparatus may be used for applying a damping-liquid to lithographic plates. This subject-matter, however, does not appear in the Specification as accepted.