GB378248A - Improvements in or relating to rotary printing machines - Google Patents

Abstract

378,248. Printing-machines. BELL, W., 2, South Terrace, Barwick-in-Elmet, near Leeds. Oct. 1, 1931, No. 27346. [Classes 100 (i) and 100 (ii).] Rotary offset machines ; sheet-registering devices ; sheet guides.-In a rotary machine of the kind in which an impression cylinder 7 co-operates with a printing-cylinder 5 of equal size, e.g. an offset cylinder receiving a design from a plate cylinder 1, the sheets are fed in overlapped condition to front stops 16 which normally project from below above the feed board 15 and act to register each sheet before the prior sheet has been withdrawn completely from the board, thus permitting longer sheets to be printed by a cylinder of given diameter than can be printed on known machines. The sheets are acted on by side-registering devices of known kind comprising a reciprocating bar 24 flush with the board 15 and an oscillating shaft 25 fitted with a lever 26 provided with a fibre runner 27 and a stop which is integral with the lever 26. The stops 26 are mounted on a shaft 17 fitted with a spring-controlled bellcrank lever 19 to keep the stops normally raised, and the stops are depressed by the action of a cam on the impression cylinder upon a roller 20 on the lever 19. Other forms of front stop and methods of actuation may be used, but the complete registering operation is adapted to occupy approximately one-quarter of a machine cycle. The cam on the cylinder 7 permits the return of the stops immediately the oscillating grippers 10 have engaged a sheet, and the stops act on the next sheet before the complete withdraw of the active sheet by the grippers 10. A guide 13 prevents engagement of the sheet with the plate cylinder 1, and the cylinders 1, 7 are arranged close together as shown so as to give the maximum time for tripping the cylinder 5 in the event of failure of the feed.