Process for automatically controlling the shape of sheet metal produced in a rolling mill

Apparatus for controlling the shape of sheet metal produced in a rolling mill, said apparatus receiving a plurality of output signals from a sensor disposed across the width of said metal sheet, said sensor having a plurality of individual sensing means disposed at different locations across said width, a different one of said plurality of signals being associated with a different one of said individual sensing means;

• said apparatus comprising:
• averaging means;
• predetermined ones of said plurality of signals being fed to said averaging means, whereby the average of said predetermined ones of said plurality of signals is produced at the output of said averaging means;
• first comparator means;
• the output of said averaging means being fed to one input terminal of said first comparator means;
• predetermined other ones of said plurality of signals or other averages being fed to the other input terminal of said first comparator means;
• the output of said first comparator means being fed to means for controlling a parameter of said rolling mill;
• whereby, when said first comparator means detects a difference, greater than a predetermined difference, between the inputs thereof, said parameter will be appropriately controlled;
• said sensor comprising a shapemeter having a plurality of segments, a different one of said segments of said shapemeter being associated with a different one of said plurality of signals;
• said plurality of signals comprising electrical signal levels;
• said averaging means comprising electronic averaging means;
• said first comparator means comprising electronic comparator means;
• said averaging means comprising first, second and third averagers;
• and wherein said first comparator means comprises a processor;
• a first portion of said plurality of signals, derived from a first portion of segments on the outer right hand side of said sheet being fed to said first averager;
• a second portion of said plurality of signals derived from a second portion of segments on the outer left hand side of said sheet being fed to said second averager;
• a third portion of said plurality of signals, derived from the central segments, being fed to said third averager;
• the outputs of said averagers being fed to respective input terminals of said processor which has, stored in memory, required respective averages;
• whereby when the outputs of said averagers differ from said required averages by an amount equal to or greater than a predetermined amount, the roll bend means are controlled to bend the roll back to reduce the differences.