Method and apparatus for conversion of a printing press to offset printing

摘要

An apparatus and method converts an existing printing press to offset printing. An auxiliary frame and two auxiliary impression cylinders are mounted to the press and existing cylinders are adapted for offset printing. A new web path is defined to the cylinders, through an auxiliary cross brace member. The shafts of auxiliary cylinders are eccentrically mounted dead shafts. The cylinder surface is friction driven by the web. Bearers smooth the movement of the cylinders across the blanket slots. The auxiliary cylinders are maintained on impression by an incompressible fluid for uniform impression and thrown off rapidly by a pressurized gas.