Wenderoth, Lind & Ponack
Method of an apparatus for controlling hydraulic rolling reduction in a rolling mill
 The method and apparatus are provided for controlling the gap between the rolls by comparing the initial gap setting and the actual gap value and providing the quantity of hydraulic fluid for the hydraulic rolling reduction cylinder in response to the output of the comparison. The method consists of setting the value for the gap between the rolls, measuring the actual gap, comparing the gap setting value and the actual gap value, controlling the quantity of hydraulic fluid to be supplied to the rolling reduction cylinder in response to any deviation between the two values, and thereby controlling the rolling reduction for the cylinder. The apparatus includes means for setting the value for the gap between the rolls, means for measuring the actual gap, means for comparing the gap setting value and the actual gap value, means for controlling the flows of hydraulic fluid to be supplied to the hydraulic rolling reduction cylinder in response to the output of the comparator means so that one flow can occur in one direction and the other flow can occur in the opposite direction, said flow controlling means being connected in parallel for providing the hydraulic fluid for the cylinder. 
B
B21B
inventional
Keiichiro
Yoshida