GB1116682A - Offset duplicating machine having unified control - Google Patents

Abstract

1,116,682. Printing machines. A. B. DICK CO. 22 June, 1965 [10 Aug., 1964], No. 26392/65. Heading B6C. In a lithographic offset duplicating machine, movement of a control lever 80, Fig. 1, from a neutral position to successive positions causes ink to be applied to the printing surface on cylinder 42, movement of the cylinder 42 into contact with the offset cylinder 44 to transfer the image, the application of dampening liquid to the printing surface, and the feeding of copy sheets to the machine between the offset and impression cylinders 44, 46. When the lever 80 is returned to the neutral position, the machine parts revert successively to their original condition and, in addition, at the inking position a blanket-washing apparatus is operated to clean the offset cylinder. Continuing the reverse movement of the lever 80 beyond the neutral position, causes the machine to be stopped in a position suitable for the attachment of a new master printing-surface to the cylinder 42. Treating a master sheet for receiving ink and dampening fluid.-With the control lever 80 in neutral position and the machine at rest, a master sheet is placed on a table 50, Fig. 1, for reception by the cylinder 42. A lever 66 is now operated to bring a pad 62 containing etching solution, and having an hexagonal shape for alternative use of its faces, into contact with the cylinder 42. The lever 66 also operates a switch 78, Fig. 2, to start the machine, so that the cylinder 42 takes the master sheet. ' After one or more revolutions of the cylinder 42 sufficient to cause application of the solution to the entire master sheet, the lever 66 is moved to inoperative position, with the machine continuing to run. Inking of the master sheet.-The control lever 80 is now moved to position marked " Ink- and-wash ". The lever 80 rotates a cam cluster 81, Fig. 3, comprising two connected discs 84, 86 with cam surfaces, pins, and rollers to operate various parts, the disc 86 also having notches engaged by a roller on a detent lever 100. With the lever 80 in the new position, the cam 84 operates a spring-urged arm 118, Fig. 11, connected to a link. Stop surfaces 136, 138, Fig. 3, on the link engage a lever 130 so as to move an inking roller 130 into and out of contact with the master sheet on the cylinder 42, during forward and backward movement respectively of the control lever. An axiallyreciprocating distributing roller 150 contacts the roller 132. Dampening liquid is supplied by a roller 152 to the roller 150 as described below. Moving master cylinder into contact with offset cylinder.-When the lever 80 is moved forward to position marked " Image ", a roller 162, Fig. 3, on cam 86 operates a lever 166 resiliently connected to a link 174 actuating an arm 182 fixed to a shaft 184. Fast with the shaft 184 is a lever 186 which is operated to cause the master cylinder 42 to be moved into contact with the offset cylinder 44. A detent plate 198 is also fixed to the shaft 184. An inclined notch 196 in the plate 198 is engaged by a spring- urged pin 194 so as to urge the lever 186 towards its initial position. The pin 194 may be engaged with another notch 202 in the plate 198 to retain the lever 186 in inoperative position when it is manually operated. Applying dampening liquid.-The dampening liquid is applied to the ink-distributing roller 150 by a roller 152 resiliently carried by levers 238, Figs. 11, 12, and spring-urged towards a driven duct-roller 154. Lips 256 on the levers 238 are engaged by rollers 254 on levers 250 pivoted at 252 and oscillated by driven eccentrics 244 so as to move the roller 152 into and out of contact with roller 150. The pivot 252 is carried by levers 260 pivoted at 262 and adjustable by a cam 264 so that the roller 152 can be held either continuously out of or in engagement with the roller 150 or its throw varied. With the machine running and the control lever 80 not yet moved to the " Feed " position, a latch 292, Fig. 11, engages a stop 304 on the levers 238 to hold the roller 152 away from the roller 150. When the lever 80 is moved to the " Feed " position, the cam 84 imparts an additional movement to the lever 118 operating the inking roller 132, and a pin 160 on that lever rotates a lever 156. The latter, through a resilient linkage 280 actuates a lever 282 which lifts the latch 292 so that the roller 152 can oscillate to and from the distributer roller 150. Initiating sheet feed.-Upon movement of the lever 80 to the " Feed-on " position, a pin 206, Fig. 3, on cam 84 actuates a lever 210 connected resiliently to a link 216 pivoted to a hand-lever 222 controlling the sheet-feed mechanism so that feeding of sheets to the machine commences, and automatic movement of the cylinder 42 into and out of engagement with cylinder 44 controlled by the sheet-feed mechanism occurs in known manner. The lever 80 is now released and returns to the " Feed " position because of the action of the detent roller 98 on an inclined part (106, Fig. 4) of the detent notch engaged thereby, but the sheet-feed mechanism remains operative. Completion of a printing run; cleaning the offset cylinder.-When it is desired to terminate the printing of sheets from a particular master, the control lever 80 is moved back in steps to the neutral position thus rendering the sheetfeed, dampening, and inking successively inoperative, the disconnection of the sheet-feed also causing separation of the cylinders 42, 44. In addition, at the position marked-" Ink and wash ", a roller (312, Fig. 4) on cam 86 engages a lever 314, Fig. 3, so as to render operative, through a linkage 324, 326 etc., a blanket-washing apparatus 310. The linkage is devised so as to be effective only during reverse movement of the control lever 80. Stopping and braking the machine.-Subsequent to its return to the neutral position, the lever 80 is moved in the reverse direction to a " Stop " position, whereupon a lobe (352, Fig. 4) on cam 86 actuates a switch 350 connected to a positioning switch 360, Fig. 2, actuates by a permanent magnet 364 on the offset cylinder 44. When the cylinders are in a predetermined position, the switches cause energizing of a solenoid 368 to effect operation of a brake-band 372 acting on a drum 374 geared to the cylinder 44 and also to open a switch 382 in the drivemotor circuit. When the lever 80 is released, the engagement of the detent roller 98 with an inclined part (108, Fig. 4) of the detent notch (94) causes the lever 80 to be returned to the neutral position.