Abstract: A method and apparatus is disclosed for eccentricity correction in a rolling mill, in which prior to rolling, the eccentricity of the back-up rolls is measured and recorded both initially and each time the back-up rolls are changed. In an analog loop, constant roll gap is maintained by bidirectionally displacing the back-up rolls so as to maintain constant roll force in accordance with a reference roll force signal, the displacements being such as to neutralize the measured and recorded eccentricity. In a digital feedback loop, controlled by a digital computer, roll force is maintained constant in accordance with changes in the gauge of the work product, with the displacement of the back-up rolls producing a change in roll opening. The analog and digital control loops are cooperatively combined, so that the change in roll opening resulting from digital control, produces a new roll force reference for the analog loop.

Abstract: A rolling mill workpiece shear control apparatus and method are disclosed to provide adequate acceleration torque at the desired time of workpiece product cut. For particularly low product speed cut operations, a two step acceleration is provided that brings the shear to an initial low base speed of operation and at the desired time an acceleration to operating knife speed in accordance with the measured product speed. In relation to the desired product length, the time of the actual product cut is determined and updated for future similar cuts of product length and speed.