Patent ID: 8505426

Claim:
A method for operating a hydraulic shearing machine, wherein the machine includes at least one shear blade, a hydraulic actuating mechanism for operating the at least one shear blade, and a control system for the hydraulic actuating mechanism, the method comprising: cutting by shearing by performing a shearing-movement of the at least one shear blade, starting from a starting-position of the blade, under application of an overall actuating-force on the at least one blade; wherein the cutting is a rocking shearing action with a rolling movement; and subsequently, resetting the at least one shear blade, which blade had been moved for cutting, to the starting position of the blade after accomplishment of the shearing-movement of the blade, by causing a reset-movement of the at least one blade under application of an overall reset-force on the at least one shear blade; performing the shearing-movement and the reset-movement by operating the hydraulic actuating-mechanism which comprises a plurality of hydraulic cylinders, an overall actuating-force and the overall reset-force being applied to the at least one shear blade which is moved for cutting by at least two of the hydraulic cylinders of the actuating-mechanism; adjusting a magnitude of the overall actuating-force on the at least one shear blade by switching one or several of the hydraulic cylinders of the actuating-mechanism in and out of a respective operation-mode; and controlling the positions of the at least one shear blade by the control system regulating a flow of hydraulic fluid to the hydraulic cylinders according to setpoints for a shear blade position versus time function and to overall actuating-force and overall reset-force requirements.