Rotating shearing device and method for separating the front crop and rear crop from running rolling stock

A method for separating a front crop and a rear crop from a running rolling stock using a rotating shearing device, wherein the shearing device includes two axially cutting annular knives mounted for rotation about respective axes at the same rotational speed, each of said two annular knives having end cutting edges directed toward one another and converging at a cutting position to a clearance necessary to separate the rolling stock, the two annular knives arranged at an acute angle to one another and intersecting one another along a line, a front guide arranged for guiding the rolling stock to the annular knives, the front guide being switchable between an upper end position and a lower end position, and a rear guide arranged for guiding the rolling stock from the annular knives, the rear guide having lower, middle, and upper rear guide parts, said method comprising the steps of:

• introducing a start of a running rolling stock into the free space between the annular knives by the front guide part in an initial state of the shearing device in which the front guide part is in the lower end position, the annular knives are in the cutting position and the rear guide part is in the upper end position;
• pivoting the front guide part upward for separating the front crop with the annular cutting knives and discharging the front crop part into the lower rear guide part;
• running the rolling stock through the rotating shearing device above the annular knives into the middle rear guide part after separating the front crop;
• opening the annular knives and synchronously pivoting the front guide part into the lower end position and the rear guide into the lower end position during the further run-through of the rolling stock;
• closing the annular knives into the cutting position and pivoting the front guide part upward after the annular knives are in the cutting position for separating the rear crop with the annular knives and discharging the rear crop through the upper rear guide part;
• and pivoting the front guide part into the lower end position and the rear guide part into the upper end position for establishing the initial state.