Patent GB-747007-A (GB)
Title: Improvements in or relating to offset rotary printing machines
Inventor: MESTRE LUIS
IPC: B41F31/30
Filed: 1954-08-04
Abstract: 747,007. Rotary offset printing machines. GESTETNER, Ltd. Aug. 4, 1954 [Sept. 2, 1953], No. 22680/54. Class 100 (2). Inking mechanism.-A rotary offset printing machine comprises a main frame 40, Fig. 5, carrying the plate, offset and impression cylinders and the damping system, and a removable inking unit comprising a frame 40a carrying an ink reservoir 300, an ink roller in the reservoir, a pawl-and-ratchet mechanism to drive said roller, a train of inking rollers 301, 308, 310 and 312 extending from the reservoir roller to a pair of plate inking rollers 314, a driving gear 317 for the train of rollers adapted to mesh with a driven gear on the main frame, a readily detachable coupling to connect the pawl and mechanism with an' operating link 270 carried by the main frame, means for rendering the pawl-and-ratchet inoperative including an arm 368 carried by the inking unit frame and a link 374 to actuate said arm carried by the main frame, the inking unit frame being slidable into position on the main frame whereupon the driving and driven gears are brought into mesh, the inking rollers 314 engage the plate cylinder 113, the arm 368 and its link 374 are operatively connected, and the pawl-andratchet mechanism is positioned for coupling to its operating link 270. As shown in Fig. 4, the pawl-and-ratchet mechanism comprises a pawl carrier 271 rotatable about the spindle 298 of the reservoir roller, the pawl 294 cooperating with a ratchet-wheel 296 connected to the roller. The speed of rotation of the reservoir roller may be varied by a rotatable shield adapted to lift the pawl over an adjustable part of its movement, the shield being manually set. Rotation of the reservoir roller is stopped altogether by anticlockwise movement of a bell-crank lever 368 causing an upstanding arm 367 to abut a pin 297a on the pawl and displace it out of engagement with the ratchet-wheel. A detector sensing the absence of a sheet causes the link 374 to rise, a pivoted sector 370 on the end of the link being adapted to engage pin 369 and displace lever 368 so as to lift the pawl. The sector 370 is pivoted at 373 (Fig. 5) and spring loaded to the operative position. A handle 371 is provided to rotate the sector into a position where it cannot engage the pin 369 so that, when desired, the supply of ink continues even when there is no sheet fed. The inking unit frame 40a has flat bottom edges adapted to slide on horizontal upper edges of the frame 40, guide plates 280, Fig. 5, being provided on each side. An openended slot 283 in each plate 280 engages a pin 282 on the main frame and spring-loaded plungers 285 on the main frame enter locating holes 284 in plates 280. When the inking unit frame is in position the inking roller train is connected through gear 317 with a gear on shaft 265 meshing with gear 132 on the plate cylinder and sector 370 is located in engagement with pin 369 on arm 368. The inking rollers 314 are mounted on levers 337 adapted, when the inking unit frame is in position, to engage a central control cam 350 operable by a handle 359 to lift the inking rollers as described in Specification 747,003. Also when the frame 40a is in position the link 270 is located so as to be readily connectable with the pawl carrier. For this purpose a spring-loaded pin mounted on one arm of a fork at the end of link 270 is adapted to pass through an opening in the carrier 271 and into the other arm of the fork. Specifications 747,002, 747,005 and 747,008 also are referred to.