Patent ID: 6073527
Filing Date: 2000-06-13
Classification: B65H,Y10T

Abstract:
An apparatus for shingling sheets being cut from a continuous running web operating at a constant line speed utilizing a rotary helical blade cutoff knife having a counterrotating pair of interacting upper and lower helical cutting blades, each of said cutting blades having a blade edge, said apparatus comprising:means for operating the interacting helical blades with the upper blade edge positioned rotationally ahead of the lower blade edge to cut a sheet from a leading edge of the web along a transverse cut line of the cutoff knife and to cause a vertical downward deflection of a trailing edge of the cut sheet relative to a new leading edge of the web;a vacuum outfeed conveyor positioned below the cut line of the cutoff knife and immediately downstream of the knife to receive the cut sheet directly from the knife without any elements contacting or supporting said sheet between the cutoff knife and the outfeed conveyor;a vacuum source operatively connected to said outfeed conveyor to apply a vacuum force sufficient to hold a cut sheet thereon; and,means for variably controlling one of either the speed of the outfeed conveyor or the vacuum applied to the outfeed conveyor immediately after cutoff to capture the downwardly deflected cut sheet on the outfeed conveyor and to permit the new leading edge of the web to overlap the trailing edge of the cut sheet on the outfeed conveyor.