Patent GB-1135742-A (GB)
Title: Xerographic printing apparatus
IPC: G03G15/00
Filed: 1965-12-14
Abstract: 1,135,742. Feeding sheets; printing-apparatus; sheet delivery apparatus. RANK XEROX Ltd. 14 Dec., 1965 [31 Dec., 1964 (6); 4 Feb., 1965], No. 53123/65. Headings B6B, B6C and B6H. [Also in Division G2] A xerographic machine for reproducing microdata cards on sheets of copy paper has a movable card carriage for supporting and feeding individual cards during scanning to project an image on to a xerographic plate, a feed means for feeding copy sheets from a supply to effect transfer of a developed xerographically produced image in synchronism with each scanning cycle of card. General arrangement. Cards to be reproduced are singly fed from a magazine (8), Fig. 3 (not shown), to a reciprocating carriage (54). During scanning by an optical system, Fig. 12 (not shown), a latent image is produced on xerographic drum 14, Fig. 2, previously sensitized by corona generator 15. The latent image is developed by a cascade developing apparatus 16. Copy sheets are fed singly from a tray 20 by a sheet feeding mechanism 18 to feeding and registering rollers 280, 281 and subsequently past corona transfer device 21 to receive the developed image. The residual developer is cleaned from the drum by a corona precleaning device 27 and a brush 30 engaging a flicking bar 32. Residual electrostatic charges on the drum 14 are removed by a light source (not shown). Copy sheets carrying a developed image are fixed by a fuser 25 and then fed by conveyer 26 to a tray 495. Feeding arrangements for originals.-The magazine (8), Fig. 3 (not shown), has guides 38 and an adjustable throat (41) providing an exit slot (42) through which the lowermost card is fed by a movable base 44 supporting the trailing edge of that card. An adjustable member (45) engages the trailing edge of the card being fed. The base 44 is actuated by a lever 46 operated by a crank arm (49), Fig. 5 (not shown), driven by a cam-shaft (50). Feed rollers 52, 53, Fig. 3 (not shown), advance the card being fed to the reciprocable carriage (54), the shaft of roller 52 being driven continuously by a motor M12. The carriage (54) is moved slowly to the right during a card scanning operation by a roller (141), Fig. 6 (not shown), engaging a rod (142) pressed upwardly by a roller (143) rocked upwardly by a solenoid SOL-4. The carriage is returned at a faster rate by a similar mechanism including rollers (152, 155) and solenoid SOL-5. A card detector (78), Fig. 5 (not shown), operates a switch 12LS upon failure to feed a card, thereby stopping the machine. The card carriage 54, Fig. 7 (not shown), is movable axially of shaft (84). An optical glass insert (95) is provided in aperture (94). A spring-loaded pressure pad (96), Fig. 8 (not shown), presses the card against insert 95, Fig. 9 (not shown). A pivotally mounted registration plate 107 correctly positions a card on the carriage. The card carriage is reciprocated with a card for scanning a predetermined number of times depending on the number of copies required. On completion, ejector pins (120), Fig. 7 (not shown), are actuated from their rearward position, Fig. 9 (not shown), by cam-actuated cranks (122, 124). The pins (120), Fig. 7 (not shown), have square ends that engage the adjacent edge of the card and thereby eject it towards feed rollers (53, 62), Fig. 3 (not shown). Feed rollers (53, 62) deliver an ejected card into a receiver (10), having a gate (67) that may be swung outwardly to permit removal of cards. A support plate (65) is urged upwardly by a spring 76 and moves downwardly as cards are added. Feeding copy sheets. A supply of paper copy sheets 287, Fig. 28, is held in tray 20, Fig. 2. The tray has a base (288), Fig. 27 (not shown), and left and righthand angle members (290, 291). The members (290, 291) are movable towards and away from one another by a linkage system below centre section (296) actuated by a handle (325). The tray is mounted for longitudinal movement by a file cabinet drawer slide having inner races (331), Fig. 31 (not shown). A spring latch (336), Fig. 27 (not shown), releasably retains the tray in a fixed position. The tray is mounted for vertical movement by support plates (338, 341) having vertical drawer slides (347), Fig. 27 (not shown). Stops 350, Fig. 28, are arranged adjacent the four corners of the tray. To ensure that only the top sheet is fed by feed rollers 367, snubbers, e.g. 357, are arranged to overly the front corners of the stack and apply a light restraining force to the top sheet. Snubber (357), Figs. 32 and 34 (both not shown), is carried by a movable plunger (353) slidable in tubular member (355) secured member (292), Fig. 27 (not shown). The snubber (357) follows the level of the stack downwardly as the stack level is lowered. Rounded end 364, Fig. 28, rests on inclined plate 365 when the tray is retracted, e.g. for adding or removal of sheets. Feed rollers (367), Fig. 35 (not shown), are driven through a slip clutch (374) from an intermittently driven pulley (386), Fig. 23 (not shown), on shaft (SH3). Cam arm (394), Fig. 35 (not shown), engaging a pin (395), limits downward movement of arm (371), such that the rollers (367) may clear the top of the stack as the tray 20, Fig. 2, is advanced or retracted. In operation, the topmost sheet being fed by rollers 367, Fig. 28, is buckled at its middle section, caused by inward sliding movement of the front corners of the sheet, thereby ensuring separation. A motor M13, mounted for sliding movement on a bar 344, drives a gear 402 through a reduction gear. The gear 402, in the forward position of the motor M13, meshes with a gear 403 which drives a gear 406 meshing with rack 408 secured to the sheet supply tray, motor M13 is controlled by paper level switches 11 LSB and low level switch 6LS. When the level of the stack is raised sufficiently a feeler 411 opens switch 11LSB to stop the motor M13, such that the top of the stack maintains a predetermined level. Switch 6LS is opened when roller 413 engages inclined surface 415 consequent upon raising the stack to compensate its depletion to a few remaining sheets. Separated sheets are fed to registering rollers (280, 281), Fig. 29 (not shown), driven in synchronism with the drum 14 by a clutch assembly (430), Fig. 23 (not shown), having magnetic clutches (434, 435) which drive the rollers 367, Fig. 28, and the registering rollers. The magnetic clutches (434, 435) are alternately energized under the control of a switch (17LS) actuated by a cam (455). Fixing developed images. Fuser 25, Fig. 2, comprises a roller (556), Fig. 46 (not shown), which receives a quartz tube (574) carrying a resistance heating element R-1 energized under the control of a thermistor (THS-2), Fig. 51 (not shown). A lower roller (557), Fig. 46 (not shown), has a polytetrafluoroethylene coating on a layer 584 of deformable silicone rubber. The roller (557) is raised into pressure contact with roller (556) by a differential drive mechanism 610, Fig. 44 (not shown). Silicone oil is applied to roller (556) by an applicator roll (643) engaging a wick (644) resting on roller (556). To prevent toner offset a layer (577) of offset preventing material, e.g. tetrafluoroethylene, covers the roller 556. Stripping copy sheets. Copy sheets adhering to the drum 14, Fig. 2, after receiving a developed image are stripped from the drum by jets of compressed air directed towards the drum by nozzles (461), Fig. 36 (not shown), secured to a manifold (460) supplied connected to a pulsator (467) actuated by a solenoid (SOL-2). Delivering copy sheets. Copy sheets stripped from the drum 14, Fig. 2, are delivered to fuser 25 by a conveyer 23 having endless belts 24 and a vacuum chamber (511), Fig. 39 (not shown). Copy sheets are held on the belts (24) by suction. Feed roller (520), Fig. 40 (not shown), cooperates with a roller (521), Fig. 41 (not shown), to feed fixed copy sheets to a vertical transport 26, Fig. 2, comprising feed rollers (531, 532, 533, 534), Fig. 41 (not shown), co-operating with rollers (535) slidably mounted in inclined slots. V-guides (543) and a curved guide (545) direct copy sheets upwardly and into tray (495). Machine control. The machine is under the control of a circuit, Figs. 51, 52, 53 (not shown), including a copy selector (SW-4) having a rotary selector knob for preselecting the number of copies to be made for each card; such number being indicated by the appropriate lamp (LMP-8 to LMP-28).