CONTROLLED CUTTING OF MULTIPLE WEBS TO PRODUCE ROOFING SHINGLES

摘要

In a method of cutting roofing shingles, multiple webs of roofing material are moved to a cutter. The webs are positioned in stacked relationship prior to the cutter. The webs have distinct portions such as tabs. The locations of the distinct portions of the moving webs are sensed by sensors. End cuts are simultaneously cut through the multiple stacked webs with the cutter to produce separate roofing shingles from the webs. The movements of the webs are controlled, based on the sensed locations of the distinct portions, so that the end cuts of the roofing shingles are positioned at predetermined locations relative to the distinct portions.