Adjusting mechanism for a universal stand

A method of operating a universal stand including an adjusting mechanism and a control device, the universal stand including horizontal rolls and vertical rolls, wherein the adjusting mechanism includes two hydraulic control cylinders for at least one of the horizontal rolls, the at least one horizontal roll and the two vertical rolls being provided with a hydraulic fine adjustment each and all rolls having a hydraulic fine adjustment are provided with an electromechanic coarse adjustment which can be operated independently of the fine adjustment, the electromechanic coarse adjustments as well as the fine adjustments being monitored with respect to position by means of displacement pickups, the fine adjustments being additionally monitored by means of pressure pickups or rolling force pickups, comprising

• (a) carrying out a gauging procedure with the rolls being moved together in a roll kissing position, the gauging procedure including determining and electronically storing in an electronic control device stand resiliency characteristics for horizontal force patterns as well as vertical force patterns resulting from pressure-dependent formations after having adjusted average hydraulic pressures to be expected in accordance with a pass schedule and from resulting position values of the fine adjustments, and setting at zero in accordance with automatic control technology all position values and pressure values resulting under gauging conditions,
• (b) following the gauging procedure, reproducibly storing desired position values in accordance with the pass schedule for the electromechanic coarse adjustments and hydraulic pressures and displacements in accordance with the pass schedule,
• (c) prior to each initial roll of material, reproducing the data relevant for the roll adjustment in accordance with the pass schedule, whereby the rolls are electromechanically and hydraulically adjusted to the desired pass, and
• (d) during rolling, measuring deviations from the zero values of the hydraulic pressures, determining in the control device the appropriate range of the spring loading of the stand in accordance with the stored resiliency characteristic, and using the changed spring loading of the stand for correcting the zero position value of the hydraulic fine adjustments, and subsequently keeping constant this letter value as the desired value by means of hydraulic displacement control.