Tension control in a metal rolling mill
AssigneeGeneral Electric Company
InventorHoward N. Cox
Life of this patent
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Abstract
A metal rolling mill for reducing the thickness of a metal workpiece passed between a pair of opposed work rolls is controlled to maintain substantially constant tension in the workpiece on the entry side of the work rolls to thereby improve the uniformity of the workpiece gate at the mill output. Working in conjunction with a standard control for delivering the workpiece is a scheme for compensating for thickness variations in the workpiece at the entry side of the work rolls which variations would result in tension changes which would adversely affect output gage consistency.
Claims8
In a rolling mill including a pair of opposed work rolls for reducing the thickness of a workpiece passed therebetween and a delivery system for supplying the workpiece to said work rolls, a method for compensating for anticipated variations in the tension in the workpiece at the entry side of the work rolls occasioned by variations in workpiece thickness comprising:
- (a) variably supplying torque to said delivery system to thereby control the tension in the workpiece entering between the work rolls;
- (b) defining sequential segments of prescribed length of said workpiece;
- (c) determining the time at which a defined workpiece segment enters between said work rolls;
- (d) determining any differential in workpiece thickness within a defined workpiece segment;
- (e) determining an anticipated rate of change in velocity in the workpiece at the entry side of said work rolls resulting from any differential workpiece thickness determined;
- and
- (f) adjusting the torque supplied to said delivery system coil as a function of said anticipated rate of change in velocity to thereby maintain the tension in said workpiece substantially constant.
Dependencies are inferred from the claim text.