Patent GB-427336-A (GB)
Title: Improved method of and means for registering printing plates
IPC: B41F27/00
Filed: 1933-10-23
Abstract: 427,336. Printing. HART, H., 9, Kingsway, London.-(Wood Newspaper Machinery Corporation ; 501, 5th Avenue, New York, U.S.A.) Oct. 23, 1933, No. 29288. [Class 100 (ii)] Printing - surfaces; inking - apparatus.-A method of registering printing-plates comprises first locating the plate on a registering cylinder independent of the press, printing superimposed impressions from the plate to be registered and a key plate, shifting the first plate until the impressions register, marking or notching the first plate, and locating it on the printing-cylinder by means of the marks or notches. A machine for carrying out the method comprises a marking-cylinder 13, Figs. 1, 2 and 6, impression cylinder 12, and proving- cylinder 14, Fig. 3, rotated by a motor 15 through a worm 16 and gears 17, 19, 20. The gears 19, 20 are adjustable on their links and are provided with back-lash plates to prevent play. Both the cylinders 14, 13 may be placed into or out of contact with the cylinder 12 by means of eccentric bearings 30, controlled by handles 34. The key plate, preferably printing black, is first placed on the cylinder 13, where it is held for circumferential adjustment between fingers 48 actuated by levers 50 connected by a link 51. The link 51 is provided with a spring detent 53 and an adjusting-rack 56 engaging a gear 55 operated by a hand-wheel 54. The plate will be in an approximately central position when the detent 53 lies in its notch. The plate is clipped to the cylinder by clips 37, 38, Fig. 6, clip 37 being adjustable by a screw and hand-wheel 46, and clip 38 being pressed inwards by a spring 39, but releasable by means of a lever 44 acting through a bell crank 41. The approximate central position transversely is defined by a spring bail 47 engaging the clips 37. When the key plate has been clamped to the cylinder it is notched or marked by two triangular chisels 66 actuated, through arms 95, a shaft 65, and arms 93, by a roller 64 running on the edge of a stationary cam 61. The cam 61 does not normally lie in the path of the roller, but may be thrust inwards by a lever 59, and rotation of the cylinder then effects the notching ; the notching or marking may be done by pivoted cutters actuated by a rack-bar. The plate is then transferred to the cylinder 14 which is provided with clamps of a known kind and with pins to engage the notches in the plates. The plate to be registered is now placed on the cylinder 13 and an impression taken from both plates on a single piece of paper. Any adjustment which may be necessary is made by means of the hand wheels 46, 54 until a perfect impression is made, when the plate is notched. The other plates are placed on the cylinder 13 in succession and are similarly located. Registering pins are arranged on the printing-cylinders of the press to engage the notches. Inking- apparatus is provided, a plurality of founts and rolls for the different colours on the cylinder 13, and a single mechanism for the cylinder 14. Each mechanism comprises a fount 103 on which is mounted a roller 107 driven through a tongue-and-slot connection, a worm-wheel 115, a worm 26 on a spindle 25, and the shaft 23 and bevel gears 21, 22, 24. The sides of the fount press against the ends of the roller 107 and a seal is provided for the roller bearing to prevent leakage of ink. The roller is scraped by a blade 105, spring-pressed towards the roll and adjustable by racks 112 and worm wheels and worms 110, 109 controlled by hand-wheels 108. The blade 105 is mounted on a pivoted fountain back 103<a> which is normally secured in position by a wing nut. A pick-up roller 114 carried by an eccentric bearing contacts with the roller 107 and with a forme roller 131. The roller 131 is carried by a frame 130 which is mounted eccentrically on the bushings of the roller 114. The contact between rollers 107 and 114, and rollers 114 and 131 can therefore be independently adjusted by means of the eccentric bearings, which can be rotated by gear teeth engaged by worms which can be locked in adjusted position. The forme rollers are independently pressed into contact with the plate cylinders by springs 140 lying about links 142. The links 142 are connected by pin-andslot connections to eccentric straps 143, and eccentrics 145 are controlled by pedal levers 149. Adjustable stop nuts 144 on the links control the contact between forme rollers and plates. The eccentrics are so arranged that when the rollers are withdrawn they go over a dead centre and thereby hold back the rollers even when the pedals are released. Press blankets are held onto the impression cylinder by pins 73 and a tightener rod 74. Gripper fingers 76 of known type are provided to hold the paper sheets to the impression cylinder. The fingers are opened or closed by a cam 78 which is operated by plungers mounted on the machine frame. The other end of the paper sheets are held by pins and the sheets are fed to the cylinder in a known way. The cylinder is adapted to accommodate two sheets, on one of which the trial proofs are made while on the other a perfect registered print is made.