Patent GB-680249-A (GB)
Title: Duplicating machine
IPC: B41L23/02
Filed: 1950-04-17
Abstract: 680,249. Copying documents. DITTO, Inc. April 17, 1950 [April 25, 1949], No. 9338/50. Classes 100 (i) and 100 (ii). [Also in Group XXIV] A duplicating machine comprises a drum 15, means for intermittently rotating a sheetfeeding roller 79 comprising a member 56 moved back and forth between two alternative positions by rotation of the drum, a gear drive between a rotatable member 67 and the member 56 and means connecting the member 67 and the roller 79 to rotate the roller with the member 67 in a sheet - feeding direction only. The drum 15 (manually operated) is mounted between side frames 10, 11 (11, only, visible in Figs. 1 and 2) between which is also disposed a damping liquid reservoir 192, an impression roller 277, a sheet feed roller 100, and the feed roller 79 which also functions as a damping roller and coacts with a roller 251. Feeding sheets.-The shaft 13 of the drum 15 carries a cam 36 provided with a heart-shaped cam groove. A cam follower 45 is carried by an arm 56 pivoted to the side frame 11 at 50. A segment-shaped lower portion 59 of the arm 56 carries a toothed portion 64 in engagement with a gear 66 which drives the feed and damping rollers 100, 79 through a one-way clutch 67 (see Group XXIV) and a gear train 80, 86, 89. The gears 80, 86 are idlers and the gear 89 drives the feed roller 100 through a one-way clutch 90 of identical construction to the clutch 67. The idler gear 80 is pivotally mounted on the side frame 11 but the gears 86, 89 (and the clutch 90 and feed roller 100) are carried by a plate 83 which is pivotally mounted on the same axis as the gear 80. A further plate, similar in form and mounting to the plate 83, is pivotally mounted on the side plate 10 (not shown) in order to support the other end of the feed roller 100. A rod having a sleeve of suitable cushioning material extends between the two plates in order to serve as a handle for raising the roller 100. The roller 251 is pivotally supported at each end to plates 256 which are themselves pivotally mounted at 257 to the side plates 10, 11 respectively. The roller 251 is urged into contact with the roller 79 by the provision of a tail 258 on each plate 256 which is connected by a spring 260 to plates 262 which support the impression roller 277. A tray 140 for the sheets to be fed has side flanges 144 each of which has a casing (not shown in Fig. 1) in which is adjustably carried a metal plate faced with sponge rubber which engages the edges of the sheets in the pile. A guide for the sheets passing from the tray 140 to the feed rollers 79, 251 is provided by plates 152, 154. Brackets 161 secured to each end of the plate 154 each have a portion 322 which extends between opposed portions of the plates 152, 154 to determine their degree of separation. In operation, when the follower 45 passes from the position shown in Fig. 2 to the portion 47 of the cam 36, the toothed sector rotates the gear 66 clockwise, and hence rotates the feed roller 79 through the one-way clutch 67. At the same time the gear 89 rotates anticlockwise and the roller 100 is stationary. The profile of the cam groove from 47 to 49 is circular and the segment 59 remains idle while the follower engages this portion of the cam groove. As it passes from 49 back to the position shown, the arm 56 moves back to its original position and the gear 66 is rotated anticlockwise (the feed roller 79 remaining stationary). The gear 89 is thus rotated clockwise and acts through the one-way clutch 90 to rotate the roller 100. The latter acts on the top sheet of the pile in the feed tray 140 and feeds it through the guides 152, 154 into the bight of the rollers 79 and 251. The gearing is arranged so that the linear speed of the sheet is equal to the peripheral speed of the drum 15. Impression roller trip.-The impression roller 277 is mounted in ball bearings carried by the respective plates 262 which are pivotally mounted to the side frames 10 and 11 at 265 and are united by a cross bar 263. The frames 262 are urged to an inoperative position by the springs 260 but are normally retained in the position shown in Fig. 1 by a latch 278 which is eccentrically mounted on a rod 231 extending between the side plates 10, 11 and which cooperates with the bar 263. The latch may be moved to the right to reduce the pressure of the impression roller on the drum 15, or the latch may be entirely disengaged from the bar 263, either by depressing a finger-piece 290 of the latch, or by rotating an arm (not shown) carried by one end of the shaft 231. Damping arrangements.-A pump comprising a bellows 214 is carried by a bracket 208 which is mounted for limited sliding movement relative to the side plate 11. The sliding movement is provided by a slot in the bracket 208 which engages a plate of somewhat shorter length than the slot, bolted to the side plate 11. One end of the bellows rests on the flanged lower end of the bracket 208 while the other end carries a plunger 207 which is slidably mounted in the upper flanged end of the bracket 208 and is urged by the resilience of the bellows into engagement with a cam surface 65 carried by the segment 59. The bellows is connected via the interior of the plunger 207 with a flexible pipe 205 to a depending pipe 199 within the damping liquid reservoir 192. A second flexible pipe 182 leads from the bellows to a perforated pipe 172 which extends between the side plates 10 and 11. The pipe 172 is surrounded by a further perforated pipe 171. A pad 156 is carried by a holder which is formed by plates 155, 165 and which is held in the position shown in Fig. 1 between the upper sheet feeding plate 154 and a guard plate 190. The latter is bolted at each end to the side frames 10, 11 and has a latch portion 160 adjustably bolted to it at 187 which normally engages and retains the top of the plate 154. On raising the latch 160 the plate 154 may be removed, or may be hinged down about the bearing provided by the brackets 161 to provide access to the pad holder. In operation, the bellows 214 are alternately compressed and expanded by the action of the cam surfaces 65 as the arm 56 oscillates. Liquid is thereby sucked from the reservoir 192 via a non-return valve 227 in the pipe 205, and is forced through a second non-return valve 219 into the pipe 182 and thence through perforations in the pipes 171, 172 to drip on to the pad 156. The tube 170 may be primed by depressing a finger piece 240 which works in a slot 243 in the side plate 11 and is rigid with an arm 234. The latter is pivoted to the plate 11 at 231 and carries a cam surface 250 which engages the bracket 208. Master-sheet gripping and release means.-A sheet clamping bar 295 is slidably mounted in a slot 296 in the drum and is urged to clamping position by springs 305 one of which acts between each end of the drum and the head 334 of a respective bolt carried by each end of the bar 295. A shaft 293 is journalled at 294 in the drum 15 and carries arms 306 at either end. The outer end of each arm 306 is urged respectively into engagement with the heads 334 of the respective clamping bar bolt by a spring 332 acting on a lever 292 rigid with the shaft 293. An arm 266 pivotally connected to the frame 11 at 265 has a lug which lies clear of the lever 292 when it is desired to print continuously from a single master sheet. A lever 271 having a finger piece 272 and a pin 268 which engages a slot 267 in the lever 266, may be swung about its pivot 270 on the frame 11, from the full to the dotted-line position of Fig. 13. This swings the arm 266 to a position in which its lug 291 lies in the path of the lever 292 thereby causing the bar 295 to be moved to sheet-releasing position once during each revolution.