Patent GB-137917-A (GB)
Title: Improvements in or relating to planographic printing machines
IPC: B41F31/30
Filed: 1919-01-30
Abstract: 137,917. Goss Printing Press Co., (Goss Printing Press Co.). Jan. 30, 1919. Tripping - arrangements; inking - apparatus ; damping-apparatus.-In offset machines in which the offset cylinders serve as impression cylinders to each other, these cylinders are moved simultaneously away from each other and from their corresponding forme cylinders for tripping when the motor driving the machine is stopped, or the web breaks, or, when required, by an auxiliary motor, and the inking-mechanisms are automatically raised from the forme cylinders. Provision is also made for manually raising the inking- mechanisms farther, and with them the damping-mechanisms, or for manually returning the inking-mechanisms into contact with the formes. The offset cylinders 18, 19, Fig. 1, are carried by shafts 20 eccentrically mounted in bearings 21, Fig. 2, which are supported, with provision for rotary adjustment by screws 25, 26 to regulate the impression, in blocks 22 arranged to slide on the machine frame 15 and pressed upwards by springs 27, 28 mounted on rods connecting the blocks 22 to other sliding blocks 23, which are actuated for tripping by toggle-levers 31, 32 from shafts 33, an adjustable rod 34 connecting the toggles to ensure simultaneous movement. Rocking of the shaft 33 for tripping and untripping is effected by a grooved cam 96 engaging a bowl on the toggle 32 and fixed to a wheel 94 gearing with a worm 93 on the shaft of an auxiliary motor 92, which is independent of the motor 91 driving the machine, but is automatically set in motion through a suitable controller when the motor 91 is stopped, or when the web 97 breaks and fails to support a roller 98 so that contacts 99, 100 are closed, or can be operated in either direction under hand control without disarranging the automatic connexions. The rocking of the shafts 33 for tripping operates, through rods and cranks 66, 63, 65, 62. 64, 61, 59, to rock pivoted shields 58, adjustably connected to the cranks 59, into the path of the pawls 49 operating the ink fountain rolls 46, and also operates through cranks 79 and rod 82 with slotted end engaging pins 84 on cams 71 mounted on the shafts of the forme cylinders to turn the cams, so that the cam-grooves therein act on projecting arms 69 of brackets 67, which carry the inking-cylinders 68 and are pivoted on the shafts of the ink-distributing cylinders 55, so as to move the brackets apart and raise the inking- rolls from the forme cylinders 17. From this position, the inking-mechanism can be moved manually either into contact with the forme cylinders or farther away from it, and, in the latter movement, the dampmg-apparatus is automatically moved clear of the forme cylinder. To permit of this, the slotted end of the rod 82 is formed with an offset shouldered part normally bearing against a spring-controlled bell-crank 86; but when drawn down for tripping, the shoulder clears the bell-crank, and a spring 85 draws over the rod so that the pin rests in a straight part of the slot. When in this position, the cams, which are fitted with toothed wheels 73 gearing with pinions 75, may be rotated in either direction by rotation of the pinion shafts, and the cams on the two forme-cylinder shafts may be linked together for simultaneous movement. A movement of the arms in the direction to raise the inking-mechanism further also causes another cam-slot on the cams to act through a rod 77 to rock a pivoted frame 37 carrying the damping-apparatus so that the damping-rolls 43, 44 are clear of the forme cylinders. The parts are automatically reset on untripping. The auxiliary motor 92 can be set in motion in either direction to trip or untrip the cylinder by closing circuits A or A<1>, Fig. 9, respectively by push-buttons E or E<1>, which complete circuits through solenoids C or C<1> to attract cores c or c' and closes switches B or B<1>, the actuated core being locked bv a catch F or F<1> in shunt circuits H and H<1> containing switches J and J<1> until the motor 92 effects the tripping or untripping movement, when cams k or k<1> on a disk K fixed to the worm-wheel operating the groove cam 96 closes the effective switch and completes a circuit through the magnet G or G<1> to release the solenoid c or c<1> and break the circuits A or A<1>. The motor may also be operated automatically for tripping (1) when the web breaks, by causing this to close a switch 100 and complete a circuit 101 which energizes the solenoid C to operate as previously described, (2) when the main motor is cut out, this causing a preferably automatic cut-out m to close temporarily a circuit L and thereby energize the solenoid c. The cutout m is shown in the open position, in its movement to which a spring-supported catch m<3> thereon has contacted a terminal l. When the cutout is moved to start the main motor, an insulated surface on the upper face of the catch contacts the terminal l and the circuit L is not closed.