GB699516A - Improvements in or relating to lithographic offset printing presses - Google Patents

Abstract

699,516. Cylinder printing machines. HUNTERPENROSE, Ltd. May 4, 1951 [May 6, 1950], No. 11293/50. Class 100(ii) A lithographic offset printing press in which an offset cylinder 4 is traversed over a stationary horizontal forme 2 and a platen 3 by a carriage comprising a pair of frames supported for movement by guide rollers located in channels on the machine, is characterized in that the frames house bearings for the impression cylinder and for damping rollers 14 and inking rollers the guide rollers being mounted on the frames at positions between the ends thereof and at intermediate positions. The offset cylinder is mounted in eccentric bearings in the frames for movement with relation to the forme so that the offset cylinder engages the forme during movement of the carriage in one direction only, the cylinder being moved by a link 26 supporting a guide roller 27 which runs in upper and lower guide tracks 28, 29. The guide track includes pivoted rail elements adjacent the ends of the track to permit movement of the guide roller from one track to the other. One pivoted element 34 is resiliently urged to a position at which it permits the guide roller to move along the lower of the guide tracks, the other element 40 being freely pivoted so that it is raised about its pivot by the guide roller to allow it to move out of the lower guide track to the upper track. To provide the forme with ink a third rail element 52 is provided and operated by a hand lever 41 to allow the offset cylinder to be clear of the forme and the platen on movement of the carriage in both directions. The carriage is traversed by means of an electric motor 15 driving pinions which engage in racks 16, the motor being reversed by a switch operated by the carriage at the end of its travel, spring operated buffers 22 being provided.