Patent ID: 8100357
Filing Date: 2012-01-24
Classification: B65H

Abstract:
1. A method for cutting off web material in a winding machine, which comprises an upper winding roller, at least one guide plate, a lower winding roller, and a rider roller, wherein the guide plate is arranged at a location close to and below the upper winding roller and forms a channel with the upper winding roller, the upper winding roller, the lower winding roller, and the rider roller forming therebetween a winding nip, a cut-off mechanism being arranged below the upper winding roller and comprising a pivot shaft and a pinch arm extending from the pivot shaft, the pinch arm having a web engagement end that forms at least one suction opening, the web engagement end of the pinch arm comprising at least one cutting blade set immediately by the suction opening, the method comprising the following steps: (a) having a web material borne on a lower circumferential surface of the upper winding roller that is rotatable in a predetermined rotation direction to have the web material fed into and pass through the channel; (b) winding the web material which passes through the channel around a first core in the winding nip to form a paper roll; (c) driving the pinch arm to rotate in a rotation direction that is identical to rotation direction of the upper winding roller so as to have the web engagement end periodically reaching an engagement position where the web engagement end opposes the upper winding roller, the web engagement end of the pinch arm being engageable with the web material at the engagement position, the web engagement end of the pinch arm being moved in a direction opposite to the upper winding roller at the engagement position; (d) causing the suction opening to suck and hold the web material that passes through the channel at the time when the web engagement end of the pinch arm is at the engagement position; and (e) subjecting the web material to a pulling force induced by the paper roll that is formed in the winding nip so as to stretch the web material to allow the cutting blade to be set in tight engagement with the web material and thus cutting off the web material; wherein the web engagement end of the pinch arm forms a secondary suction opening between the suction opening and the cutting blade and wherein in step (d), the secondary suction opening and the suction opening of the web engagement end of the pinch arm suck and hold the web material substantially at the same time when the web engagement end is at the engagement position.