Patent GB-747003-A (GB)
Title: Improvements in or relating to offset rotary printing machines
Inventor: MESTRE LUIS
IPC: B41F31/30
Filed: 1954-08-04
Abstract: 747,003. Rotary offset printing-machines. GESTETNER, Ltd. Aug. 4, 1954 [Sept. 2, 1953], No. 22676/54. Class 100 (2). In a rotary printing-machine comprising a plate cylinder 113, Fig. 2, and an ink and a water supply system for the cylinder the ink system comprises a pair of inking rollers 314, a lever 337 to carry each roller, the levers being substantially parallel and spaced apart and pivotally mounted for movement of the rollers towards and away from each other to engage and disengage the printing cylinder, and the water system comprises a damping roller 250 movable towards and away from the printing cylinder; a common-manual control is provided for a pair of cams 350, 352, one of which lies between and adjusts the inking rollers and the other of which adjusts a linkage for moving the damping roller, the arrangement being such that the damping roller is applied to the plate cylinder before the inking rollers. Inking mechanism.-The inking system is mounted on side plates 40 forming part of a removable ink unit as described in Specification 747,007. The spindles 336 of the inking rollers are attached to the levers 337 in the manner described in Specification 747,008. The levers 337 are pivoted to the side plates at 338 and urged towards each other by springs 346, this movement being limited by adjustable stops 348. Inward projections 351 on the levers coact with opposite sides of cam 350 which is rotatable with a shaft 265 on the end of which is mounted a handle 359. Operation of the handle causes the rise parts of the cam to move into engagement with the projections 351 thereby swinging the rollers 314 out of engagement with the plate cylinder. The inking rollers are supplied with ink from a pick-up roller 299, Fig. 6, rotating in a reservoir, by a messenger roller 301 oscillating between the roller 299 and a transfer roller 308 which passes the ink by way of rollers 310, 321 to a roller 312 in contact with the inking rollers. The messenger roller 301 is oscillated about its mounting shaft 303 by a cam follower 305 on another arm 304 engaging a cam 307, Fig. 2, rocked as described below. An eccentric on a driven shaft is connected by a link to a rocker, the ends of which are connected to links 270, 219. Link 270 is connected to rock a carrier 271 part of which forms the cam 307. A pawl 294 mounted on the carrier engages a ratchet wheel on the shaft 298 of the pick-up roller 299. Part of the stroke of the pawl may be rendered inoperative by a cowl member rotatable by a handle 362 to cover part of the ratchet wheel, thereby adjusting the rate of feed of ink. Distributing rollers 320, 322 may bear on inking rollers 314, as shown in Fig. 6. The train of rollers 308, 310, 312 are driven by interengaging gear-wheels through a gear 264 on shaft 265 meshing with a gear ring 132 mounted on the plate cylinder. Damping mechanism.-The damping roller shaft 253, Fig. 6, has flattened ends adapted to be received in plates at each end. The ends are also engaged in straps 256, Fig. 2, urged downwardly by springs 257. Vertically slidable members 1256 having shoulders bearing under the ends of shaft 253 may be displaced upwardly by bell-crank levers 261. The vertical arms 263 of levers 261 engage with cams 352 on the handle-operated shaft 265. Rotation of handle 359 causes rotation of levers 261 and lifts the damping roller out of engagement with the plate cylinder. Moisture is fed from a reservoir 224, Fig. 6, by a pick-up roller 223 rotated by an oscillating pawl 227, Fig. 2, actuated through link 219 as described for the inking mechanism. The active stroke of the pawl is variable by a lever 238 to adjust the rate of feed of damping liquid. An oscillating messenger roller 240, Fig. 6, mounted on arm 242 fast with shaft 243 is actuated to move between the pick-up roller 223 and a transfer roller 247 by a cam follower 245, Fig. 2, mounted on an arm 244 also fast with shaft 243. The transfer roller 247 is mounted on an arm 248a freely mounted on shaft 243 and spring-loaded towards roller 250. This resilient mounting for roller 247 allows it to be displaced as roller 250 is raised. The transfer roller 247 carries a driving gear 251 which is driven from gear-ring 132 by an idler gear 252, Fig. 6.