Sheet transfer mechanism for printing press

摘要

A sheet transfer mechanism comprising a gripper bar which engages the leading edge of a freshly printed sheet to move the sheet along a curved path and a sheet guide member having a guide surface formed thereon which has a radius of curvature significantly less than the radius of curvature of the curved path to guide the sheet along the path while the printed surface of the sheet is separated from the guide surface by an air cushion. At least a portion of the guide surface on the guide member is rough to carry a boundary layer of air. The guide surface is positioned relative to a vane to form an air chamber having an air dispensing passage such that rotation of the guide member forces air thorough the chamber and through the dispensing passage in a direction generally perpendicular to the guide surface to assure that the freshly printed surface on the sheet does not contract the trailing edge of the guide surface. Orifices through the guide surface communicate with the air chamber to deliver streams of air through the guide surface.