Improvements in high-speed stop-cylinder printing presses

摘要

1,021,348. Printing-machines; feeding sheets. MASCHINENFABRIK JOHANNISBERG G.m.b.H. March 1, 1963 [March 6, 1962], No. 8300/63. Headings B6B and B6C. A printing machine, Fig. 1, such as a a stopcylinder printing press, is provided with means for discontinuing printing in the event of incorrect sheet feeding and means for automatically resuming printing when a sheet is correctly fed, and is characterized in that a pawl 2 is pivotally arranged on an actuating lever 1 forming part of a linkage for tripping the impression cylinder and is movable by means of a cam lever 14 either into the path of a lever 11 adapted to move the cylinder into a printing position, or into the path of a lever 10 adapted to trip the said cylinder. A link 3, having a roller 4, and a spring-loaded rod 5 form a toggle lever arrangement which causes the pawl 2 to bear positively either against a pin 6 or a pin 7 of the lever 1. When the lever 14 is moved by an electromagnet 13 the toggle device 3, 4, 5 is moved to cause the pawl 2 to bear against the respective pin 6 or 7. As a result the pawl 2 contacts either the nose 8 of the lever 11 or the nose 9 of the lever 10, thus causing the cylinder to slide vertically on movement of an eccentric bolt. Feeding sheets registration and detection.-On a feed table 16, Fig. 9, is mounted a shaft 17 supporting feeler needle devices 18. A lever 19 is rotatably supported on the shaft 17 and is movable to and fro, Figs. 7 and 8 (not shown), by a slide rail 20 and a stop bar 21. The rail 20 is reciprocated by an eccentric device 24, Fig. 1, and when no sheet is present the feelers 18 enter holes 16b in the table 16, and the lever 19 retains the bar 21, and on further movement of the rail 20 a lever 29 is pivoted to engage a switch 31 and energize the electromagnet 13 which trips the impression cylinder. When a sheet arrives the feelers slide over the sheet, the bar 21 moves with the rail 20, and a lever 30 is pivoted to operate a switch 32 so that printing is automatically resumed.