Patent GB-302966-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41F9/10
Filed: 1927-09-22
Abstract: 302,966. Hoe & Co., Ltd., R., and Bennison, W. E. Sept. 22, 1927. Rotary intaglio machines; gripper mechanism.-A rotary power plate printing-machine is constructed with grippers carried by discs freely mounted on the impression cylinder and driven by epicyclic gearing so as to be retarded after taking a sheet from the feed-board 3, Figs. 1 and 2, the sheet being advanced during printing solely by the plate cylinder 1 and impression cylinder 2. The manner of mounting and operating the grippers forms the subject matter of Specification 302,983. The printed sheets are delivered by a chain 4. Inking-apparatus. - The plates 6, Fig. 1, are inked by rollers 63 supplied from a duct roller 40, Fig. 6. which rotates in a duct 39, nnd co-operating with the roller 40 is an adjustably actuated transfer roller 60 co-operating with distributing rollers 61, 62, 63 for applying ink to a printing-forme 6. The roller 60 is mounted in lever arms on a shaft fitted with a spring- pressed bell-crank lever 56 provided with a roller 56<a> normally co - operating with a cam 57 on the shaft 41 of the duct roller 40. When desired, contact of the roller 60 with roller 40 can be prevented by means of a stop 53 engaging a projection 54 on the bell-crank 56, or this stop may be so operated as to adjust the time of contact of the roller 60 with the roller 40. 'The stop 53 is carried by a bell-crank lever 51 connected by a link 50 to a bell-crank lever 48, 49 having an adjustable screw connection 47 with lugs 46 on a lever 45 oscillated by a cam 42 on the shaft 41. By adjusting the screws 47 the movement given to the stop 53 can be varied, and thus the time of contact of the rollers 40, 60 can be controlled. The plates 6 are scraped by a doctor blade 8 which is provided with means for automatically removing the scraped ink from the blade 8, this ink-removing means preferably consisting of a roller 87, Fig. 8, with which the blade 8 is periodically brought into contact. The blade 8 is mounted on a shaft 64 and normally maintained in the position shown in Fig. 8 by a cam 80 on cylinder 2 acting on a lever arm 78 which is adjustably connected to a forked member 65 secured to the shaft 64. An adjustable spring-controlled rod 82 normally presses the lever 78 towards cam 80. 'When the plate 6 passes the scraper, a cam 72 rocks a lever 69 connected by a spring-pressed rod 68 and a pin 66 to the member 65, and the shaft 64 is moved clockwise to contact with the roller 87 which is mounted in adjustable levers 89. An adjustable scraper 82 keeps the roller 87 clean, and deposits ink into a reservoir 93. The shaft 64 is mounted in bearing 94 adjustable by screws 95. For inspecting the blade 8, the rod 68 may be disconnected from the member 65, and when the shaft 64 is rotated by hand in an anticlockwise direction, the spring-pressed rod 82 maintains the parts in the inspection position. After being scraped, the plates 6 are wiped by strips 9 which pass over wiping pads 10 which are reciprocated axially of cylinder 1 in guides 142, which are mounted slidably in brackets 143 and are normally pressed by springs so as to maintain the pads 10 in contact with the plates 6. Extensions on the guides 142 are pressed into contact with discs concentric with the shaft 95 of cylinder 1, and these discs maintain the pads 10 at a constant distance from the cylinder 1 whether this cylinder is in tripped or working position. The pads 10 are normally reciprocated in the guides 142 by eccentrics on a horizontal shaft driven by bevel gearing from a shaft 152 geared by bevel gearing to the shaft 37 of the chain delivery mechanism. The shaft 152 by skew gearing drives a series of eccentrics 154 which operate pawl-and-ratchet mechanism to rotate wheels 159 intermittently, the wheels 159 being geared to rolls 160 for winding up the strips 9 into rolls 161. The strips 9 are paid out by rolls 162 fitted with controlling brakes' for controlling the tension of the strips. Tripping-arrangements.-The shaft 95 of the plate cylinder 1 is mounted in eccentric bearings 96 which are themselves mounted in outer eccentric bearings 97 adjustable by worm-gearing operable by a spanner to adjust the printing pressure. The printing contact between the cylinders 1, 2 can be broken or made only when the plates 6 are out of alignment with the cylinder 2, and the tripping mechanism for effecting this is shown in Fig. 2, and comprises a thrust block 122 fixed to a shaft 118 on which are arms 123 connected by rods 102 to the eccentric bearings 96. The shaft 118 is rotated clockwise to throw the cylinders 1, 2 into engagement, and in the reverse direction to trip the cylinders, by means of discs 126 freely mounted on the shaft 118 geared to oscillating sectors 128 operated by cams 131 on shaft 31 which is one of the driving shafts of cylinder 2. The discs 126 are formed with shoulders which can engage one or other of two pawls pivoted to the outer ends of the thrust block 122, and these pawls are controlled by cam discs operated by a segmental gear connected by a rod to an arm on a shaft 104 which is operable by a foot-pedal 103, and in the other direction by a spring. The shaft 104 is fitted with arms engaged by catches for holding the cylinders tripped or in operative position, and these catches are controlled by cams associated with the cam member 28 for releasing the shaft 104 so as to permit the cylinders to break or make contact only when the plates 6 are out of alignment.