Patent GB-1046469-A (GB)
Title: Improvements in or relating to rotary duplicating machines
IPC: B41L11/08
Filed: 1963-08-19
Abstract: 1,046,469. Printing-machines; feeding sheets. W. RITZERFELD, and G. RITZERFELD. Aug. 19, 1963 [Aug. 24, 1962; April 26, 1963], No. 32657/63. Headings B6B and B6C. A rotary duplicating machine suitable for hectographic, lithographic or letterpress printing comprises a printing drum 1, Fig. 1, to which a mirror-script printing sheet or a lithographic or letterpress master printing sheet is attached, an inking mechanism 8 having an inking roller 13 movable to co-operate with the drum 1 for lithographic or letterpress printin o  and adapted to be tripped for hectographic printing, a damping mechanism 230 having a damping roller 246 movable to co-operate with the drum 1 for lithographic printing and adapted to be tripped for hectographic and letterpress printing, and a moistening device 115 for moistening the copy sheets during hectographic printing and adapted to be tripped when the inking mechanism 8 is rendered operative. Printing operation and tripping of impression roller.-The impression roller 91 is adapted to be swung towards and away from the drum 1 about an axis 90 under the control of cams arranged on a shaft 92, Fig. 4, which rotates synchronously with the drum 1. The cams are subdivided for selective printing into a heading cam 93, heading extension cams 94a and 94b, a cam 96 for whole page printing, and line printing cams 98a. 98b and 98c which are radially and axially adjustable. The peripheral displacement of the line cams is effected by a pawl stepping mechanism 118-124 via switching, rollers 125a, 125b and 125c. These rollers are introduced by magnets 220-222 which are selectively switched on manually by a pull rod 141. Sensing rollers 106-108 co-operate with the cams and transmit the motion to the roller 91 via levers 102-104, an intermediate lever 109, and a knee joint 110-113. The heading setting is effected by manual actuation of a rod 129, Fig. 4, said rod being locked in a position according to the desired heading length. The drum 1 is released for a single printing revolution by a single revolution clutch after the feeding of a copy sheet. Inking mechanism.-The inking mechanism 8 is rendered operative, for instance for lithographic printing, by pressing a key T1, Fig. 1, which interrupts the current to an electromagnet M1 and causes thei nking roller 13 to swing and engage the drum 1 under spring pressure and a protective mask 75 on the roller to swing downwardly. The removable ink supply container 28 rests on angle rails 30 which are swingable on bearing studs 29 and is adjustable by manually pulling levers 32 and 33. Ink is lifted on to a supply roller 16 from the container 28 by a rubber member 27 fixed to a rotatable shaft 26. The container 28 acts as its own drop tray. The roller 16 is mounted in levers 17 and by adjustment of a screw 22 may be swung about studs 19 to vary the gap between said roller and a transfer roller 25 to ensure a precise adjustment of the ink supply. The drive of the rollers 16, 25 and of a further transfer roller 15 is effected from a toothed wheel 35 carried by the drum 1 via a toothed wheel 36 and a pinion 37 on a shaft 38, Fig. 10. Depression of the said key T1 simultaneously switches in a magnetic clutch 40, the annular magnet 39 of which is connected to the shaft 38 by a key 41. The armature plate 42 of the clutch is connected with a toothed wheel 43 which drives the rollers 15, 25 via a wheel 45, and roller 16 via a pinion 48 and a toothed wheel 49. The rollers 13-16 are of increasing length. Damping mechanism.-The damping mechanism 230, Fig. 6, comprises a trough 231 containing water 232, a fountain roller 236, and the roller 246 which is adapted to be swung towards and away from the drum 1 and which may be rendered inoperative for hectographic or letterpress printing by actuation of a hand lever 253. The drive of the rollers 236 is obtained on depression of the key T1 through the wheels 35, 36 and pinion 37, Fig. 10, via a toothed wheel 239. The setting of the inking and damping length for printing and the control of the rollers 13 and 246 is derived from a set of cams 54, Fig. 6, adjustably arranged on the shaft 2 of the drum 1. After the termination of lithographic or letterpress printing depression of the key T1 switches off the clutch 40 and energizes the electromagnet M1 so that the drive to the inking and damping mechanisms is interrupted and the roller 13 is swung away from the drum 1 and the mask 75 is raised. The ink container 28 is swung downwardly by depressing connecting rod 34 and the damping mechanism is rendered inoperative by swinging down the lever 253. Hectographic printing.-With the inking and damping mechanisms rendered inoperative the master sheet on the drum 1 may be replaced by a hectographic master sheet 152, Fig. 1. The supply of spirit to the moistening device 115 is stopped during lithographic or letterpress printing but is restored on energization of the electromagnet M1 which rotates a shaft 64, Fig. 1, and operates a lever 73 co-operating with a liquid pump 78. The copy sheets 114 are fed between co-operating feed rollers 116, 117. Sheet-feeding and sensing devices.-In the embodiment of Figs. 12-16 a release magnet 270 remains energized until a copy sheet 114 has been faultlessly fed between an upper steel roller 116 and a rubber-covered roller 117 and interrupts the current through a pair of paper feelers 271 which are unbalanced by counterweights to press lightly against the roller 116. The armature of the magnet 270 then swings away from a release latch 278 so that the rotary machine is released for operation. The drum 1 carries an insulating plate 291 which supports slip rings 292, 293, 294. The rings are connected to three contacts arranged along the clamping edge of the plate. A fixed arm 295, Fig. 15, carries slip contacts 296, 297, 298 which are connected to relays which are energized if a conductive lithographic printing plate is in place and cause an electromagnet to be deenergized so that the ink roller 13 swings towards the drum 1. If a non-conductive hectographic master sheet is present the relays are not energized and the roller 13 is maintained out of contact with the drum. Indicators.-The circuit of Fig. 16 (not shown) provides for the illumination of a blue lamp 284, Fig. 12, when hectographic printing is in progress. A yellow lamp 300 indicates ink printing and green and red lamps 305 and 306 indicate the use of different printing lengths A5 and A4, Fig. 6. Printing surfaces.-The plate shown in Fig. 15 is secured between an insulating rail 285 and a clamp 286 carrying an insulating rail 287 provided with three contacts, Fig. 14 (not shown). The drum 1, Fig. 2, is provided with permanent magnets 7 fixed in recesses therein and the lithographic master sheet 5 carries a thin iron strip 6 which is 0À040-0À1 mm. in thickness and about 6-8 mm. in width.