Method and apparatus for positioning a web of material in stepwise transporation thereof

摘要: For accurate positioning of a web material which is to be transported stepwise by at least first and second feed means through processing stations disposed therebetween, the are controlled programmable computer stores value representative length distance covered during transportation step. The tension measured compared reference stored in computer. If actual deviates from drive one such way that substantially adjusted increasing or reducing portion step drawn into region between means.