GB620770A - Improvements in or relating to a perfecting offset press - Google Patents

Abstract

620,770. Rotary printing machines. HARRIS-SEYBOLD CO. July 12, 1946, No. 20894. Convention date, July 13, 1945. [Class 100 (ii)] A perfecting offset press comprises two blanket cylinders 14, 16 in printing relationship, the cylinder 14 having grippers 15 conveying sheets S through the impression line to a delivery point, and a feed-impression cylinder 12 carrying sheet-grippers 13 disposed in impression relationship with the cylinder 14 so that air is squeezed from between the sheets and the cylinder 14. Impressions are transferred to the cylinders 14, 16 from plate cylinders 17, 18, inked and damped by mechanisms 19, 20 and equipment 21, 22 respectively, and so positioned that a stripper cylinder 23 may closely co-operate with the blanket cylinders for delivering sheets to grippers 25 on a travelling band 26. The sheets are held against cylinder 14 by brushes 28. In a modification, Fig. 2 (not shown), the cylinders 14, 16 are twice the size of cylinder 12, two sets of grippers being provided; also, the sheets may be fed from above by two feed cylinders transferring the sheets downwardly between the cylinders from where they are transferred to a delivery web by stripper and delivery cylinders below. According to the Specification as open to inspection under Sect. 91 the sheets are prevented from being smudged by holding them away from the cylinder 14 by a jet of air from a nozzle 35, Fig. 4 (Cancelled), the sheets being supported on a guard 34. The feeding cylinder 32 is recessed so the sheet will not contact the cylinder 14. This subject-matter does not appear in the Specification as accepted.