Patent ID: 8696537
Filing Date: 2014-04-15
Classification: B65H

Abstract:
1. An apparatus for forming a stack of interfolded sheets of porous material including a trailing panel having a full panel width joined along a fold line to a leading panel having a partial panel width that is less than the full panel width, where the sheets define a trailing edge of the trailing panel and a leading edge of the leading panel spaced from the fold line by the full panel width and the partial panel width respectively, the apparatus comprising: a pair of counter-rotating folding rolls having respective peripheries thereof defining a nip between the rolls and having cooperating grippers and tuckers alternately circumferentially spaced around the peripheries of the rolls at the full panel width with the rolls being operatively connected for counter-rotation in a timed relationship to one another such that the grippers from each roll interface cooperatively with respective tuckers from the other roll at the nip; and a control arrangement configured and operatively connected for positioning the leading edges of the sheets both upstream and downstream from the nip with vacuum applied through corresponding vacuum ports disposed in the periphery of the first and second folding rolls at a circumferential distance equal to the partial panel length ahead of each gripper and tucker in the direction of rotation; wherein, the control arrangement is further configured and operatively interconnected for positioning the leading edges of the sheets downstream from the nip by applying sufficient suction for holding both the leading edge of the leading panel of a given sheet and an underlying portion of the trailing panel of the immediately previous sheet against the periphery of one or the other of the rolls downstream from the nip.