PROCESS FOR CROPPING THE HEAD OF SELF-LUMINOUS ROLLED MATERIAL, ESPECIALLY METAL STRIPS AND SYSTEM FOR CROPPING THE HEAD

The invention relates to a process for cropping the head of self-luminous rolled material, especially metal strips when it passes a rolling train. A line scanning camera is used for detecting the shape of the head by repeatedly generating optical images of the rolled material immediately downstream of the last roughing stand. The distance separating the cutting line from the beginning of the head is determined in accordance with the shape of the head. Immediately upstream a pair of shears the velocity and the beginning of the head are detected. A control signal for the shears is generated in accordance with the signals for the beginning of the head and for its velocity and with the distance of the cutting line from the beginning of the head. In order to detect the edges of the rolled material from the beginning of measurement even under wide variations of the radiation intensity the exposure time of the line scanning camera is controlled by a radiation-intensity measuring device in the sense of obtaining an optimum exposure in respect of the edges of the rolled material.