Patent GB-189923184-A (GB)
Title: Improved Method and Apparatus for Printing, and Principally for Planographic or Lithographic Multicolor Printing.
Inventor: HADDAN HERBERT JOHN
Filed: 1899-11-21
Granted: 1900-02-10
Abstract: 23,184. Haddan, H. J., [American Lithographic Co.]. Nov. 21. Lithographic and like printing; rotary machines; delivery apparatus; driving machines by electromotors. - Relates to printing - machines, and especially to lithographic machines for printing in several colours. One form of such printing- machine, partly shown in Fig. 14, comprises a central impression roller 3, and fifteen printing- rollers 5 arranged circumferentially about the roller 3 and provided with separate inking- mechanisms 6 and damping - mechanisms. The rollers 5 print successively on a certain part of a web which is cut on leaving the machine. The impression roller is driven from a main shaft by means of toothed wheels which gear with two internal racks 461. The impression surface is preferably formed of vulcanized india-rubber. Ea h printing-roller comprises an outer strong but thin tube mounted upon a concentric cylinder 9, which is removably mounted upon a shaft 11 ; the tube is adjustable longitudinally upon the cylinder 9 and the cylinder 9 is adjustable circumferentially upon the shaft 11. The pressures between the impression rollers and printing-rollers can be adjusted by means of radial arms connected to the bearings of the printing-roller shafts and actuated simultaneously by means of an oscillating arm bolted to a shifting block, which is connected to the inner ends of the radial arms. The rollers 5 are driven by means of pinions 23 and teeth 24 on the roller 3. Each inking-apparatus is carried by a swinging frame 25 secured to the shaft 37 which supports an ink drum 36, and each frame can be swung away from its corresponding printing-roller by means of a toothed segment secured to the shaft 37 and engaging with a worm mounted on a radial shaft which is driven by means of a toothed wheel concentric with the impression roller 3. In order to allow any frame 25 to be swung independently of the others, each worm is provided with means for disengaging it from its shaft. The position of each frame 25 can also be adjusted at will so as to regulate the pressure between the printing-rollers and inking- rollers. The doctor roller 40 of each inking- apparatus is driven at an adjustable rate, by means of a pawl and ratchet mechanism and an eccentric on the hub of a toothed wheel which forms part of gearing employed for driving the corresponding ink drum 36 from the impression roller 3. Ink is transferred from each ductor roller by a roller 41 mounted in bearings which are reciprocated by means of a pin working in a cam carried by the corresponding ink drum. The distributing-rollers are driven by gearing, but the inking-rollers are driven frictionally ; both sets of rollers are mounted in adjustable bearings, and the whole is so arranged that, when the frames 25 are swung away from the printing-rollers, no two rollers of the inking- apparatus are in contact. Ink is supplied to the ink ducts 466 from ink reservoirs, one for every colour printed, connected by tubes to the ducts. The reservoirs are worked under pressure, being connected to a compressed-air reservoir. Each printing-apparatus is provided with a damping- mechanism, which comprises a porous roller or water fountain 49, a brass rider 50, and damping rollers 51<1>, the whole being carried by a swinging frame 51 mounted on hubs concentric with the shaft 37. The frame 51 is connected by an adjustable rod to an arm 493 mounted upon a shaft 492, which is rocked by means of a lever engaging with a pin 491 on an oscillating wheel 54. The wheel 54 is driven from a shaft actuated by means of a controlling-engine to be described later, and its motion may be independent of that of the printing-mechanism. The roller 49 is mounted adjustably and removably within slots in the frame 51, and is movable therein by means of an oscillating arm 59 and cam mechanism. The rollers 50, 51 are carried in adjustable sliding boxes. Water is supplied to the roller 49 from a flexible tube attached to a tube which is concentric with, and discharges into, the interior of the roller ; the water is supplied under pressure by a pumping-apparatus furnished with a filter. Fig. 56 shows part of the printing-machine together with an apparatus for use in removing the outer tube from a printing-roller 5, and replacing the tube by another. A travelling carriage supported upon racks 67, concentric with the impression-roller 3, carries lifting-forks or rods 72 which are employed for grasping the spindles 11 of the printing-rollers. The carriage is moved along the racks, and the rods 72 are actuated by means of an electric motor, controlled by means of suitably-arranged electric circuits and gearing used in conjunction with clutch mechanisms. When a tube is to be removed from, or placed in position upon a printing-roller, the carriage is moved along the racks into a position suitable for removing the roller, which is then brought opposite one of a series of tube holders 74 secured to a frame 107. By means of sliding pins 109, the ends of the holders 74 can be locked to the spindle of the printing-roller. The frame 107 is mounted upon a standard 108, and can be revolved by means of a motor 110 and gearing 112, 113, 114, 117, 119, 120 ; the standard can also be moved towards or away from the machine by means of a stationary screw 111, nut 123, and gearing 122, 112,123. In a modification, the tube holders are mounted upon swinging heads carried by brackets which can be raised or lowered by means of gearing and vertical screws. The movements of the printing-rollers, inking- mechanism frames, and damping-mechanism frames are controlled by means of a controlling-mechanism so that the printing, inking, and damping rollers may move into and out of their operative positions at the proper times. This controlling-mechanism comprises three sets of toothed gearing respectively connected to the printing, inking, and damping mechanisms and to bevel-wheels loosely mounted upon a shaft and driven, when required, by means of toothed gearing and electrically - controlled clutches from the main driving - shaft. The clutches are successively operated by means of separate electric circuits so as to bring the printing rollers and the damping and inking mechanisms into their operative positions ; when the parts named have reached their operative positions they are preferably stopped automatically by the successive opening of the electric circuits. All these movements are controlled by means of a multiple switch or controller, and by the same means the printing, damping, and inking mechanisms are moved into their inoperative positions after the printing operations. The switches employed in the electric circuits are of a well-known form. Any variety of electric clutch may be used, but a preferred form comprises fast and loose parts interlocking by means of teeth the bearing-faces of which are inclined at an angle of 45 degrees to the opposed faces of the clutch. Before the web is printed on one side by means of the mechanism described, any suitable matter may be printed upon the opposite side by means of a separate printing- machine mounted upon the framing. Fig. 64 is a longitudinal view, in section, showing a bronzing and dusting apparatus removably attached to the printing - machine, and occupying the places of three of the printing-mechanisms. Size is supplied by rollers or other suitable means from a trough 337 to a sizing-roller 336, and water is supplied to damping-rollers 338 in any suitable manner. The sizing-roller is mounted in adjustable bearings, and is driven by means of gearing from the impression roller. Upon the surface of the sizing-roller is a prepared design corresponding to the parts of the web intended to be covered with bronze, which may be applied by means of a rapidly-rotating wire brush or a nozzle 341 delivering compressed air. The bronze powder is fed from a reservoir 344, pivoted at one end and oscillated by means of arms 346. The bronzed parts of the webs are rubbed by endless belts 347 mounted upon oscillating frames ; the belts are covered with fur or other suitable material Superfluous dust is removed from the web by rotary brushes 368, mounted within a chamber 366, and a felt-covered or similar roller 370 mounted within a chamber 367. The dust is withdrawn from the chambers 366, 367 by an exhausting - apparatus 369, and passes through a cylinder 372, provided with inclined shelves which serve to separate the dust for re-use. The web is trimmed along the sides before being printed upon, by two pairs of rotary discs, and the trimmed web passes over the impression roller, upon which it is held by spring-pressed grippers secured to the roller and actuated by cam pieces attached to the framing. After being printed, the web is seized by grippers carried by endless chains, and cut into sheets by means of cutters mounted adjustably upon shafts. The grippers may be of any suitable form, but are preferably spring-pressed gripers actuated by fixed inclined bars. Finally, the sheets are passed through a heating-chamber having double and cover walls packed with asbestos, and heated electrically. In a modified form of printing-surface, there are four printing-mechanisms for printing in several colours, arranged around the impression roller. The printing-surfaces may be prepared upon a uniform film of zinc electrolytically deposited upon the thin copper tube which is adjustably mounted upon the cylinder 9, Fig. 14 ; the copper tube is very accurately turned and polished, and during the process of electrodeposition it is clamped to the opposed ends of two longitudinallyadjustable shafts which are mounted in line with each other and rotate within the electrolytic bath. When such a printing-surface has been employed in printing a design, the zinc is dissolved away carefully by means of nitric acid, and the copper tube is cleaned and used again in the preparation of another printing-surface. Accord