Patent ID: 6578479
Filing Date: 2003-06-17
Classification: B41F,B65H,Y10S

Abstract:
Method for maintaining desired web tension values in a web advancing through a rotary printing machine, the rotary printing machine including a printing unit for printing the web, turner bars downstream of the printing unit for guiding the web and any web stream divided from the web one above another through a folder superstructure, a folding former downstream of the turner bars to which the web and any web stream laid on one another pass, drive means for pulling the web and any web stream through the printing machine, the drive means including a plurality of pull units, each pull unit having first and second drive lead values storable in a computing and memory unit, the pull units including a first pull unit upstream of the printing unit, a second pull unit upstream of the turner bars, third pull units downstream of the turner bars, a fourth pull unit upstream of the folding former, a fifth pull unit downstream of the folding former, and optionally a sixth pull unit downstream of the printing unit and upstream of the second pull unit, said method comprising the steps of:starting up the printing machine at a selected web speed and with print thrown off from the printing unit, and operating the second, third, fourth, fifth and sixth pull units at the first drive lead values of each of the pull units for providing optimal tensions in the web; throwing the print on in the printing unit including ink and optionally damping solution; and operating the printing machine with the second, third, fourth, fifth and sixth pull units at the second drive lead values of each of the pull units for providing the optimal tensions in the web.