GB663335A - Improvements in or relating to a rotary printing press - Google Patents

Abstract

663,335. Printing-machines. HARRIS-SEYBOLD CO. Sept. 13, 1949 [Sept. 15, 1948], No. 23585/49. Class 100 (ii). A three cylinder rotary printing press has its intermediate cylinder mounted on a shaft carried in the press by a pair of inner eccentrics fitted within a pair of outer eccentrics which are turned together to throw the intermediate cylinder out of contact with one of the other two cylinders; and has means for turning said inner eccentrics in said outer eccentrics for throwing the intermediate cylinder out of contact with the other of said two cylinders. As shown the intermediate cylinder is an offsetblanket cylinder 11, operating between a plate cylinder 10 and an impression cylinder 12, and is moved out of contact with them if e.g. there is an interruption in the feeding of sheets, which operates a mechanism moving a rod 67 to the left, Fig. 1. Rod 67 rocks a lever 65 clockwise, which through a connection 66 draws a thrust block 55 to the right until its upper end contacts a pin 50 on a yoke 47 so that when the high part of a cam 16 on the shaft 9 of cylinder 12 moves a follower 59 and lever 57 clockwise about a pivot 58, the thrust block 55, which is pivoted on the lever 57, is directed upwardly and its right hand shoulder, now underlying the pin 50, turns the yoke 47 anticlockwise. Yoke 47, on being turned, gives a pull to a link 34 having a micrometer adjustment 41 and 42 not shown with a pivotal connection 33 to an extension 32 of the outer eccentric 18 rotatably held on to the frame 14 by bolts and washers 88, 89 through slots 90. This action moves the axis 25 of the blanket cylinder 11 downwardly and to the left about the axis 27 of the outer eccentric 18. At the same time a second extension 85 of the outer eccentric 18 travels clockwise about axis 27 and moves a bell crank lever 76, pivoted on the extension at 86. The lever 76 has one arm connected by a link 72 and a second micrometer adjustment 73-79 to a lug 70 extending from the inner eccentric 17 which is thus moved clockwise a similar amount to the outer eccentric 18. The other arm 87 of the lever 76 terminates in a pivotal connection with a rod 92 subsequently operated to move the cylinder 11 away from cylinder 12. This is effected by the cam 16 when its high part reaches a follower 107 which rocks a lever 105, connected to a thrust block 103, the right hand shoulder of which has by the previous action of extension 85 and interconnecting links 114-112 been positioned below a pin 98 on a yoke 95, so that the upward movement of the thrust block 103 rocks the yoke 95 anticlockwise drawing rod 92 downwardly and through mechanism 87, 76, 72, adjustment 73-79, and lug 70 rotates the inner eccentric 17 relative to the outer eccentric 18 causing the axis 25 of cylinder 11 to rotate clockwise about axis 26 of the inner eccentric i.e. substantially away from the cylinder 12. Since the pivot between the rod 92 and extension 87 of lever 76 is substantially in alignment with the axis 27, the initial movement of the inner eccentric by the outer eccentric does not effect any movement of cylinder 11 away from cylinder 12. A second pair of eccentrics are fitted on the other side of the machine, the outer eccentric being operated through the shaft 48 which extends from yoke 47 to a similar yoke at the other side and the other inner eccentric is operated from the first by meansof a key 22 therein turning the shaft 17. A similar sequence of operations, occurs when throwing-on the cylinders and in both cases the high portion of cam 16 is arranged to effect throw-off or throw-on when gaps G1, G2 and G2, G3 are co-incident. When it is required to commence printing and ink-up the blanket cylinder 11, it is held away from the impression cylinder. This is accomplished by disconnecting the lever 113 from the extension 85 by means of spring-plunger 127 so that when the outer-eccentric is moved anticlockwise to effect throw-on between cylinders 10, 11-the thrust block 103 having remained in contact with pin 98 on yoke 95-the operation of cam 16 does not effect throw-off of cylinders 11, 12. The spring plunger 127 is normally held by a spring to engage a notch in the extension 85 but has a knob so that it can be pulled outwardly and rotated to a latched position.