Patent ID: 8342086

Claim:
A drive device for a bending press, the drive device comprising a press frame, a press table, and a press beam which is adjustable relative to the press table via a hydraulic system comprising a hydraulic pump with a controllable drive motor, a switching and control device and pressure lines and a pressure store with pressure cylinders chargeable by a pressure medium, and the hydraulic system with a ring line comprising the hydraulic pump forms a switchable flow circuit closed by control valves for the pressure medium with a first line section of the ring line between a pressure chamber of at least one pressure cylinder and the hydraulic pump and with a second line section of the ring line between an additional pressure chamber of the pressure cylinder and the hydraulic pump and the pressure store is flow connected via at least one of the control valves optionally with the first line section or the second line section of the ring line for holding or releasing a stored volume of the pressure medium, the at least one pressure cylinder comprising a piston separating a cylinder chamber into the pressure chambers, the piston including a first piston active surface for applying a pressing force onto the press beam and a second piston active surface opposite to the first piston active surface, wherein the first piston active surface is smaller than the second piston active surface and a surface ratio of the first and second piston active surfaces is greater than 1 to less than 1.5.