Patent GB-593397-A (GB)
Title: Improvements in planographic printing machines
IPC: B41L19/00
Filed: 1945-08-21
Abstract: 593,397. Printing-machines. NEWTON, E.P. (Addressograph-Multigraph Corporation). Aug. 21, 1945, No. 21403. [Classes 100 (i) and 100 (ii)] An offset planographic printing-machine is constructed with a plate cylinder 20, offset cylinder 23, and a platen roller 24, mounted in pivoted arms, the sheets being fed from a horizontal table 145 by an operator who can control the printing operations by the aid of a pair of levers 111, 112, Fig. 2, and a pair of pedals 230, 231, Fig. 1, not shown, which control the action of a continuous clutch and a braking-mechanism, or the action of a clutch which stops the machine in positions in which the operator can attach one end of a printing- plate 21, Fig. 5, to securing pins 52 arranged in a recess in the roller, and (2) the other end of the plate can be attached to pins on a spring- pressed bar mounted in the cylinder. The levers 111, 112 control respectively means for bringing a damping &c. roller 18 into contact with the plate 21 and subsequently an inking roller 16 also, and the lever 112 controls means for bringing the plate cylinder 20 into contact with the offset cylinder 23 and subsequently the platen roller 24 into coaction with the offset cylinder. The rollers 18, 16 are each carried by bearings which can slide in inclined slots in the machine frame, and are controlled by a pair of cam plates 32, 38 which are moved by a pair of cams 41, 44 on a shaft 42 which is controlled by a rack 121 on a link 120 connected by linkwork to the lever 111. This lever is first moved from its full line to dotted line position, Fig. 2, to throw the roller 18 into action and is then moved to a position corresponding to that occupied by lever 112 to throw the roller 16 into action, and also to permit a supply roller 17 to contact the roller 16. The lever 112 controls the position of eccentric journals 66, 67 of a shaft upon which the plate cylinder is freely mounted. One journal 66 is mounted in an adjustable eccentric bush 85 to enable the cylinder 20 to be accurately aligned, and the other journal 67 is secured to a sleeve 71 having a latch 70 which when the machine is out of action engages a notch in a latchplate 73 adjustably secured to the frame. The sleeve 71 is adjustable to throw the plate cylinder into contact with the offset cylinder by means of a control member 75 which when rotated first releases the latch 70 and then rotates the journals. The member 75 is adjustably connected to a disc 131 which is operated by the lever 112 which operates a shaft 116 having an arm 126 with a roller 127 capable of moving in a slot 128 in a link 129 connected to the disc 131. A spring 130 transmits motion to the link 129 but when contact of the rollers 20. 23 occurs the roller 128 moves in the slot and finally comes to rest in an offset portion of the slot. The final movement of the lever 112 operates bv a pin-and-slot connection a toggle device 135, 136 which is broken to depress the inner end of a pivoted member 25 in which the roller 24 is mounted and the roller is thus raised to printing position after the offset roller receives its impression. The sheets are fed from a table 145 arranged in front of the machine, and are delivered to a tray 172 arranged beneath the table 145, by means of strippers 150, Fig. 5, carried by the offset cylinder and actuated by a fixed cam 149. A groved roller 168 and tined guides 170, 171 direct the printed sheets to the tray 172. The machine is driven by a shaft 183 geared to the printing cylinders, and the shaft 183 is driven by a freely mounted pulley 202, Fig. 3, which can drive the shaft 183 by a clutch comprising a friction clutch plate 206 which is arranged between discs 207, 208 which are secured to the shaft 183 and are normally separated by springs so as not to be driven by the plate 206. The discs are pressed together by levers 214 operated by inclined surfaces on a sliding collar 213 when this is moved to the right in Fig. 3 to throw in the clutch. The collar is operated by a bell-crank lever 216 operated when a pedal arranged below the tray 172 is depressed. The collar 213 is normally pressed to the left by a spring, and the shaft 183 is then held by a friction brake similar in construction to the clutch.. A second clutch pedal is provided which when depressed causes the plate cylinder to rotate for half a revolution only. Depression of the second pedal operates the clutch and at the same time a latch mechanism holds the clutch in, until a cam 242 on the shaft 90 of roller 23 releases the clutch and throws in the brake so as to stop the cylinder 20 in a position in which access to the plate-securing means is permitted. Specifications 593,400 and 593,401 are referred to.