Abstract: A method and device for slitting or edge trimming strip material on a process line are described in which trimming knives 2 mounted on a base 3 which is pivotally mounted on a sub-base 4, trim the edges of strip 14. The lateral position of the strip is sensed by sensors 10 and the position of the strip relative to center line of the process line is determined by a computer (not shown) which controls the lateral movement of the sub-base 4 by a hydraulic jack 9 so as to keep the strip and trimmer in alignment. The speed V of the strip is sensed and the speed V.sub.T of the trimmer is sensed by a transducer 12. The base 3 and thus each pair of knives 2 is pivoted about a pivot 11 on the sub-base 4 so that the angle .alpha. the knives make with the center line of the process, tends to equal tan .sup.31 1 (V.sub.T/V).

Abstract: A method and apparatus for winding strip material is described in which strip which has partially severed scrap edge portions still frangibly attached thereto, is wound on to a coil or mandrel so that the cut edges of the strip are aligned. The strip passes past trimming knives which partially sever the edge portion and sensors measure the lateral position T of the knife and the lateral position E of the uncut edge of the edge portion adjacent to the knife position A. The scrap width T--E is then recorded. As the strip is about to be wound on to the coil at position B the lateral position R of uncut edge of scrap portion is sensed by a sensor. The appropriate scrap width is then determined by reference to the recorded scrap width and the strip travel between points A and B which is determined from a tachometer attached to a roll over which the strip passes.