Patent ID: 8474675
Filing Date: 2013-07-02
Classification: B65H

Abstract:
1. A device for automatically controlling edges of a web of sheeting, comprising: a first deflecting roller and a second deflecting roller arranged next to each other in an axial direction in such a way that the web of sheeting travels widthwise over at least one section of each of the first and second deflecting rollers; at least one drive for shifting the first and second deflecting rollers in opposite axial directions, including towards each other and away from each other; a sensor for detecting a position of the web of sheeting; a means for changing a ratio between a friction of the web of sheeting on the first deflecting roller and a friction of the web of sheeting on the second deflecting roller; and an automatic control device for controlling the at least one drive for shifting the first and second deflecting rollers in opposite axial directions and for controlling the means for changing the ratio between the friction of the web of sheeting on the first deflecting roller and the friction of the web of sheeting on the second deflecting roller based on the position of the web of sheeting detected by the sensor; the device operable in a first mode wherein the automatic control device shifts the web of sheeting in a first direction towards the first roller through a combination of a) moving the first and second deflecting rollers away from each other while the ratio of friction is such that the friction between the web of sheeting and the first roller is greater than the friction between the web of sheeting and the second roller, and b) moving the first and second deflecting rollers towards each other while the ratio of friction is such that the friction between the web of sheeting and the second roller is greater than the friction between the web of sheeting and the first roller.