Patent GB-190307021-A (GB)
Title: Improvements in and pertaining to Printing Machines.
Filed: 1903-03-26
Granted: 1904-02-11
Abstract: 7021. Coulthard & Co., T., and Coulthard, T. March 26. Cutting and perforating- apparatus; cylinder machines with plane printing- surfaces ; inking - apparatus.-In web - printing machines with plane printing-surfaces, having two sets of impression cylinders, arranged symmetrically on opposite sides of the central line of the machine, devices are used to equalize the amounts of ink supplied to the several inking- rollers of each set ; also, improved means are employed for controlling the movement of the mangle-rack and for raising and lowering the impression cylinders to clear the bed on its return motion, and the various impression cylinders, cutting-cylinders and other apparatus are driven from one longitudinally arranged shaft. Behind each impression cylinder 4, Fig. 1, is an inker roller 6, which gets its ink from an ink slab 3. This slab is inked from the ductor, which is at the centre of the machine, and when the slab is freshly inked, it comes into contact with the hindmost inker rollers first. In order to prevent these rollers from getting too much ink, and the foremost, or lefthand, rollers from getting too little, the hindmost inking-rollers are raised from contact with the ink slab, after having only passed half way over it, by cams 12, 12, leaving the remainder of the ink for the foremost rollers. In front of the ink slab is a printing-surface 1, and as this returns in the reverse direction of the arrow 8, the inking-rollers 6, 6, 6, 6 are lifted by cams 11, 12 to clear it. On the outward stroke of the printing-surface, each inking-roller 6 inks the printing-surface 1 before it reaches the impression cylinder 4. A large part of the weight of the inking-rollers and the rider rollers 10<b> above them, is taken by springs, on balance-weights acting on the lower end of the cam rods 10. The mangle-rack 19 for driving the table of the machine may have its motion controlled and made smoother by being fitted with two rollers 21, 22 running on a closed path consisting of two circular ends 23, 24, and two straight sides 25, 26. Two parts 27, 28 of the circular path may be fitted with leather pieces to avoid the shock when one of the rollers 21, 22 is carried over from one straight part to the other. When the table is running in the direction indicated by the arrow, the impression cylinders must be held in contact with the printing-surface, while, when it runs in the reverse direction, the cylinders should be lifted out of contact with the printing- surface. This may be accomplished by mechanism shown in Fig. 10, where the bearing 37 for one end of the cylinder shaft is carried between two adjusting-screws 36, 38, in a sliding stirrup-piece 34. A spring 40, the compression of which is regulated by turning the screw 38 in the sleeve 39, supports one half the cylinder, and presses the lower end of the stirrup 34 against one end of the shaft 35. This shaft has a flat at each end, in exactly the same plane, and the ends, when casehardened and ground, form cams, against which the bottoms of the stirrups or slides 34 (one at each end of each cylinder) press. By these means the cylinders are firmly held against the printing- surfaces when the latter are moving in the right direction, and are elevated to clear the printing- surfaces when the latter are returning. Finally, the various impression cylinders and cutting rollers of the machine may be driven from a shaft 45, Fig. 11, running along the machine, helical gearing being used to drive this shaft from the driving-shaft 47, and also to drive the cylinders, through intermediate spur gears. The cutting-rollers 54, 55 are driven by bevel gearing, as indicated.