Abstract: An impression cylinder for a rotogravure press having a recessed sheet stock gripper mechanism with a swivelling mechanism that swivels the grippers within the cylinder contour by revolving the grippers around a theoretical axis on the cylinder contour. The swivelling is rigidly and precisely constrained along an arcuate path by a plurality of arcuate guides disposed along the axial length of the cylinder. The opening and closing of the grippers and the swivelling of the grippers into the cylinder contour are caused to occur in sequence synchronized to the cylinder rotation by cam followers on gripper shaft pivot arms cooperating with cam followers journaled to the gripper shaft that are spring pressed onto cam surfaces fixed to the machine frame at the ends of the cylinder.

Abstract: A sheet fed printing press having an impression cylinder with a feed board presenting a sheet with its leading edge in a position for pick up. A rotary sheet feeder is interposed between the feed board and the impression cylinder for picking up the leading edge of the sheet from its stationary position and transferring the leading edge to grippers on the moving impression cylinder. The sheet feeder is directly driven by a high powered electric motor. High resolution pick up heads and associated angle coders produce output signals respectively representative of the phase position of the cylinder and sheet feeder. A programmed phase offset device is provided defining a predetermined relation of desired feeder phase as a function of impression cylinder phase.