Patent GB-820828-A (GB)
Title: Improvements in or relating to printing or duplicating machines
Inventor: JANKE EDWARD JOSEPH
IPC: B65H3/08
Filed: 1957-09-02
Abstract: 820,828. Feeding sheets. ADDRESSOGRAPH-MULTIGRAPH CORPORATION. Sept. 2, 1957, No. 27606/57. Class 100(1) In apparatus for feeding sheets to a printing &c. machine, the sheets are stacked on a raisable support and are fed by a sheet separator to a pair of feed rollers, and the sheet separator movements are controlled by two cams which are movable together. The apparatus is shown as applied to a rotary offset duplicator comprising an impression roller 21, an offset roller 22, and a printing roller 23. A motor 19 through belts, pulleys, and gears 24, drives the roller 22, and the other rollers may be geared to the roller 22 or be driven by frictional engagement therewith. A cam 41 on the offset roller 22 oscillates a lever 43 which reciprocates a bar 45 which actuates means for operating a suction sheet separator and for raising the pile table, as described below.  Pile tables. A pile of sheets W is supported on a table 25 vertically slidable on the frame 10 and provided with chains 29 which pass around sprockets 31 and are provided with counterweights. The sprockets 31 are secured on a cross-shaft 33 which has secured thereto a ratchetwheel 34 engaged by a detent pawl 38 and a driving pawl 39. The shaft 33 can be rotated manually to adjust the height of the table 25 by means   of   a depressible knob 35 which is co-axial with the shaft and serves to displace the pawls 38, 39 and engage the shaft drivingly when it is depressed. The pawl 39 is carried on a bracket 75 rotatably mounted on the shaft 33, but normally retained by a latch 22: when the latch is rocked, the bracket swings to the left under the action of a spring, and a slotted lever 80, reciprocated periodically and which engages over a pin on the bracket, can then swing the bracket 75 back to the right and so cause the pawl 39 to drive the ratchet-wheel 34 and raise the pile table 25. The latch 72 is pivoted along its length and has a pin and slot connection with a vertical link attached to a pivoted bracket which is rocked periodically by a cam about its pivot, but its clockwise movement is controlled by a pivoted oscillating bail 40, Fig. 3, carrying feelers 47 which engage the. top sheet W of the pile. When the top sheet of the'pile is below a predetermined height, the bail 40 of the feelers 47 allows the bracket controlled thereby to depress the vertical link and trip the latch 72. The bar 45,' which is reciprocated periodically by the cam 41 on the offset roller. 22, is pivoted at 49 to a main driving cam 51 secured to a sleeve 53 rotatably, mounted on a fixed . stud 52. A cam secured to the sleeve 53 rocks the feeler bail 40 and the associated bracket which - controls the latch 72. The slotted lever 80 is pivoted to one arm 82 of a bell crank, the other arm 85 of the crank being connected by a link 86 to the oscillating driving cam 51: 'the slot in the lever 80 allows the latter. to reciprocate idly until the latch 72 is tripped..  Sheet separators and forwarders. Sheets W are separated sequentially from the pile by a suction foot 110 and forwarded to a pair of feed rollers 100, 101, Fig. 3, and are then fed to the duplicator by endless tapes 170. The roller 101 and the tape rollers 171, 172 are driven through gears &c. from the machine motor. The sucker 110 is clamped by , a screw 112 to a cross-rod 111 mounted in arms 115 secured to a shaft 116 rotatably mounted in the side frames 50. A lever 117 secured to one end of the shaft 116 is rocked by the cam 51 which causes the sucker 110 to rise and fall. An overhanging arm 122 on the cam prevents overthrow of the roller 118 on the lever 117 at high speeds. The horizontal movements of the sucker 110 are imparted by a cam 130, Fig. 4, secured to the cam 51, acting on a lever 132 secured to the rod 111 whereby the latter and the sucker are rocked. The lever 117 can be lifted to permit the sucker to be disabled without interfering with the operation of the pile raising or With the timed relationship of the various mechanisms. The main cam 51, which is actuated by the bar 45 from the offset roll 22, controls the application of suction to the sucker 110. A valve 140, Fig. 4, in the suction line 114 has a vent 141 to atmosphere controlled by a valve member 142 on a pivoted arm 143 rocked by a bar 151 connected to the bell-crank arm-82 which is rocked by the cam 51. The valve 140 has a second vent 156 controlled manually by a rotary valve member 157 to regulate the suction at the sucker 110. A motor-driven pump 109 provides suction, and also a source of positive air pressure through a line 160 which is directed across  the front of the pile to assist sheet separa-  tion. A valve 165 in the pressure line 160 regulates the force of the air blasts.