Patent GB-848247-A (GB)
Title: Improvements in or relating to duplicators
IPC: B41L11/08
Filed: 1957-11-15
Abstract: 848,247. Addressing or like machines; gripper mechanism; feeding and delivering sheets. THOMPSON, J. E. Nov. 14, 1958 [Nov. 15, 1957], No. 35720/57. Classes 100(1) and 100(2) A hectographic duplicator comprises a drum, a motor for driving the drum, means for feeding paper sheets into contact with a hectographic master sheet on the drum while the latter is rotating, a holder for a plurality of masters, means for removing a master from the holder and feeding it to a gripper on the drum, and means for releasing the master from the drum, the arrangement being such that masters can be fed automatically through the duplicator in succession. One or more copy sheets may be printed from each master. The master sheets are stacked substantially vertically in a hopper 11, Figs. 1, 2, 3, 4 and 8, comprising a face 12, Fig. 3, with a slot 15 for withdrawing masters, adjustable side lays 17, adjustable top lays 23, members 25 for bending the edges of a master to prevent feeding of two together, and air holes 201 for blowing air between masters. The hopper is pivoted about an axis 32 by levers 37, 35 and a cam 39 on the shaft 40 of the drum 100. Feed sucker mechanism 50, Fig. 4, carried on arms 45, 45a on a rod 46 is oscillated by a cam 42 on the shaft 40, and arms 43, 44, upwards to mater-receiving position adjacent the slot 15 at the time when the hopper 11 is in its left-hand position, Figs. 1 and 8, or right-hand position in Fig. 2. Suction from a tube 70 is provided in a hollow rod 51, and through flexible tubes from outlets 55 to inlets 53 on two sucker blocks 52, a third sucker being supplied, for use with wide master sheets, through a two-position slide valve 57. In the lower position of the sucker mechanism, an arm 67 is moved by an abutment 147 to a position which cuts off communication between the tube 70 and the rod 51, and releases the latter to atmosphere, while in the upper position, the lever 67 is moved to restore the communication by a bellcrank 137, provided a solenoid 135 is energised, when a switch 110 is closed. Master sheets are fed by the suckers between a long knurled roller 140 driven from the drum drive and one or two ball races 141, Figs. 1 and 8, two races being used for wide masters, one being moved axially out of engagement when not in use and thence to a gripper 101, Fig. 6 at a speed slightly greater than the peripheral speed of the drum. On rotation of the drum, the gripper is closed when a roller 102 on the gripper arm runs off a cam 103 on the drum, and opened for delivery when the cam re-engages the roller, if a solenoid 108 is energised, when the switch 110 is closed. If the solenoid is not energised, the cam is moved to inoperative position. Master sheets released by the gripper are delivered by suckers 80, Fig. 5, on rollers 79 supplied with suction through tubes 74 during 150 degrees of their revolution, to a delivery roller 216 and thence to a tray 96. Copy sheets 213 are fed from a stack 207 by a roller 208, a mild steel roller 210, and a rubber damping roller 209 driven intermittently by gearing of the duplicator, the time of driving being'controlled for vertical adjustment of the printed matter by a manually adjustable cam 221, Fig. 2. A third solenoid is energised to open a clutch and stop the drum rotation through a circuit including the switch 110, a contact 143 and the arm 45a when in its lower position, and the roller 140 and ball race 141. When the sucker mechanism 50 is in its lower position, therefore, the drum is stopped if there is no master between the roller 140 and race 141. When the machine is set to print one copy sheet from each master sheet, the switch 110 is kept closed by a spring- urged sector 111. A second sector 117 of transparent synthetic plastic material and having a knob 118, Fig. 1, has a hole 116 engaging a pin 115 on the sector 111. A lever 125 carrying a pawl 122 is oscillated by the cam 39, the pawl 122 being held out of engagement with teeth of the sector 111 by a cam track 119 on the sector 117 engaging a pin 121 on the pawl. The sector 117 has nine further holes 116A, and if the sector 117 is rotated so that the second hole 116A engages the pin 115, the machine prints on three copy sheets from each master sheet. The pawl 121 is now allowed to engage the teeth and the sector 111 is moved one step on each rotation of the drum, being engaged by a holding pawl 124, thereby opening the switch 110 to disable the sucker mechanism 50 and the gripper-opening mechanism by de-energising the solenoids 135, 108, and to prevent stopping of the machine when there is no master sheet being fed to the gripper. On the third revolution, a pin 123 on the pawl 124 is engaged by a nose 130 of the sector 117 to release the pawl 124, while the pawl 122 is moved to inoperative position by the cam track 119, so that the sector 111 is returned by a spring 113 to its original position and closes the switch 110.