Patent ID: 7555984
Filing Date: 2009-07-07
Classification: B41F

Abstract:
1. A printing plate replacing method in a web offset press for replacing a printing plate wound around a plate cylinder by using a scaffold installed between a plurality of printing units disposed at an interval along a travel path of a web, the method comprising the steps of: dividing a part of the scaffold on a side where work for replacing the printing plate is performed, and disposing the divided scaffold above the travel path of the web in a manner capable of being raised and lowered; forming a released web area in a region from an in-feed section to a dryer section via the plurality of printing units by forming a clearance between blanket cylinders nipping the web from both sides in the plurality of printing units; lowering the divided scaffold to a position adapted for the work for replacing the printing plate of the upper plate cylinder while pressing down the web with a lower surface of the divided scaffold by utilizing a sag of the web in the released web area; and subsequently replacing the printing plate of the upper plate cylinder by using the divided scaffold.