Patent GB-170303-A (GB)
Title: An improved printing press
IPC: B41F3/30
Filed: 1921-10-14
Abstract: 170,303. Reeve, V. L. Oct. 15, 1920, [Convention date]. Cylinder machines; offset machines; bed reciprocating apparatus; tripping arrangements; inking-apparatus.-A cylinder machine for printing by direct or offset printing comprises a reciprocating bed with one or more formes which, on the forward motion of the bed, each print an impression on paper, metal, &c., carried by an impression cylinder, or on an offset cylinder which is raised from the bed after receiving an impression. The formes return without making further impressions, and during this return the offset cylinder, or cylinders, is or are raised to effect the printing operation. When printing in several colours, the various impressions may be arranged side-by-side, or superimposed, and the web is passed over an adjustable roller so as to enable correct register of the superimposed impressions to be obtained. As applied to a web printing machine, Fig. 1, the web is fed from a roll mounted in brackets 82, over guide rollers 83, 84 by feed rollers 85 which are geared together and driven substantially continuously by separate ratchet drives operating alternately, the ratchets being driven by chains from a shaft 100 geared by sprocket gearing to the shaft of an oscillating inking-roller 41 driven from a rack 64 on the bed. From the rollers 85, the web passes over a table 86 on which the web rests in a slack condition ready to be fed forward through rolls 87 by the printing rollers of the first couple 65'. From this couple, the web passes over a roller 89 which can be adjusted so as to cause the impression produced by a second couple 65 to register correctly with the print from the first couple. The printed web passes through rollers 90, over a roller 91 to a winding roll 92 driven by a friction clutch, or if cut sheets are desired, the web passes from roller 91 to fixed inclined slitting knives 96, and thence to a rotary transverse cutter and delivery apparatus. The wound roll 92 can be passed again through the machine for printing the, reverse side. The formes are supported on a table 21, Fig. 2, adjustable by wedges 36, operable by a right and left hand screw 37, in a frame 21<1> which is reciprocated by means of a series of wheels 22 mounted in a frame formed of longitudinal beams 31 connected by a shaft 30 which is reciprocated by a pitman 29 operated from a counter-shaft 27 geared to the main shaft 24. The wheels 22 engage racks 23 fixed to the machine frame 20, and also racks 35 attached to the bed, and by this means the travel of the bed is twice that of the pitman 29. The bed commences its movements to the left from the position shown in Fig. 15, which shows the machine arranged to print an impression from one forme 66 on to an offset cylinder 65<a> of a printing couple 65, and impressions from three formes 67, 68, 69, on the offset cylinder 65<a> of a printing couple 65<1>. Each forme is inked by a roller 41 which is then raised by a cam 41<1> on the bed, or by other means, into contact with a distributing-roller 40, Fig. 8. The forme 66 prints an impression on the front offset cylinder 65<a> and then this cylinder is raised by a cam 75, lever, and an adjustable connecting-rod connected to the bearings of the cylinder directly or through an adjustable spring connection. The cylinder 65a is first moved to a neutral position and is rotated in this position through a halfrevolution to bring it in correct position to cooperate with the impression roller 65<b> which it does on the return motion of the bed. After the impression is effected, the cylinder is lowered to neutral position, and finally, after the forme has returned past the cylinder, to such a position that it can again co-operate with the forme 66. The other offset cylinder 65a is similarly operated only it receives impressions from three formes 67, 68, 69, before it is raised from the bed. The inking-apparatus for each forme comprises a. roller 41 which is moved in brackets 38, Fig. 8, as described, and coacts with an adjustably mounted roller 40 in the brackets 38. The rollers 40 are supplied by transfer rollers 44 mounted in oscillating arms 49, operated by levers 49<1> connected to a link 50 operated by a lever 51 and cam 52 on shaft 27. The rollers 44 are supplied by duct rollers 45 rotated intermittently by ratchet gearing from the rollers 41 oscillated by sprocket gearing from gears operated by the rack 64 which also is geared to the offset cylinder by gears which are spring- mounted to keep them in gear as the cylinder rises and falls. The rollers 41 are fitted with distributing rollers 57 mounted in spring-pressed arms 54 by screw bearings 56 which reciprocate the rollers 57 longitudinally. The machine may operate on sheets forwarded by automatic feeding apparatus to forwarding tapes, and may print on tin. As applied for direct printing, the offset cylinders are removed and replaced by impression cylinders which print in direct co-operation with the formes 66 &c. on the forward motion of the bed 21. To facilitate the insertion of new formes, the tracks 23 are fitted with extensions which are normally folded up but which can be moved beyond the end of the frame 20 to permit the bed to be drawn out and supported thereby while the formes are fixed. The rollers 22 are disengaged from their driving-gear during this operation.