An electro-hydrostatic drive for realizing a rapid movement and a force-building movement, comprising a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-flow of a hydraulic fluid, a first cylinder with a housing, a piston, a cylinder rod, and a first and a second cylinder chamber, a second cylinder with a piston, a cylinder rod, and a first and a second cylinder chamber, a moveable carrier plate, a pillar, and a clamping apparatus to clamp and/or unclamp the first cylinder to the pillar, where the hydraulic drive has a closed hydraulic circuit, which has, when run, a positive pressure above atmospheric pressure and which, by utilizing the hydro-machine, can pressurize either the first or the second cylinder chamber of the first cylinder and/or the first or the second cylinder chamber of the second cylinder. The moveable carrier plate is connected both to the first cylinder and to the second cylinder. For the force-building movement, the first cylinder is clamped, by the clamping apparatus, to the pillar and one cylinder chamber of the first cylinder is pressurized with the hydraulic fluid, and for the rapid movement, the first cylinder is unclamped, by the clamping apparatus, from the pillar and one cylinder chamber of the second cylinder is pressurized with the hydraulic fluid.

Disclosed is a piston-cylinder assembly of a hydraulic press, which includes a basic cylinder and a first and second piston. A ring cylinder is formed above the basic cylinder as a continuation of the cylinder structure. The first piston is located inside the basic cylinder in the bottom part of the basic cylinder and the second piston is located above the first piston in the top part of the cylinder structure. The piston-cylinder assembly has a first hydraulic fluid space below the first piston and a second hydraulic fluid space below the second piston and the piston-cylinder assembly includes a unified hydraulic fluid channel in flow connection to the first hydraulic fluid space in order to provide a pressure effect in the first piston and to the second hydraulic fluid space in order to provide a pressure effect in the second piston.

An electro-hydrostatic drive for realizing a rapid movement and a force-building movement, comprising a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-flow of a hydraulic fluid, a first cylinder with a housing, a piston, a cylinder rod, and a first and a second cylinder chamber, a second cylinder with a piston, a cylinder rod, and a first and a second cylinder chamber, a moveable carrier plate, a pillar, and a clamping apparatus to clamp and/or unclamp the first cylinder to the pillar, where the hydraulic drive has a closed hydraulic circuit, which has, when run, a positive pressure above atmospheric pressure and which, by utilizing the hydro-machine, can pressurize either the first or the second cylinder chamber of the first cylinder and/or the first or the second cylinder chamber of the second cylinder. The moveable carrier plate is connected both to the first cylinder and to the second cylinder. For the force-building movement, the first cylinder is clamped, by the clamping apparatus, to the pillar and one cylinder chamber of the first cylinder is pressurized with the hydraulic fluid, and for the rapid movement, the first cylinder is unclamped, by the clamping apparatus, from the pillar and one cylinder chamber of the second cylinder is pressurized with the hydraulic fluid.

An actuator device includes two drive units for an actuator output element. The first drive unit has a first piston chamber and a first piston displaceable therein and also first hydraulic means for displacing the piston. The second drive unit has a second piston chamber and a second piston displaceable therein and also second hydraulic or pneumatic means for displacing the piston. The second piston is joined to the actuator output element for conjoint movement therewith and can be coupled to the first piston for thrust, so that the second piston is displaceable in an outward direction by the first piston. The first drive unit is configured for a larger thrust force than the second drive unit, while the second drive unit is designed for a greater stroke speed than the first drive unit.

The invention relates to a hydraulic drive (1) comprising a working cylinder (2) and a travel cylinder (3) which is mechanically connected to the working cylinder (2). The working cylinder (2) and the travel cylinder (3) each comprise an upper and a lower cylinder chamber (21, 22, 31, 32), and all four cylinder chambers (21, 22, 31, 32) of the working and travel cylinder (2, 3) are connected to one another in a suitable manner in a closed pressure circuit (4) which is filled and prestressed with a hydraulic fluid (F). A rotational speed-variable hydraulic machine (5) with a first and second pressure connection (51, 52) is arranged in the pressure circuit (4) in order to conduct the hydraulic fluid (F) between the individual cylinder chambers (21, 22, 31, 32) of the working and travel cylinder (2, 3) during the operation (B) of the hydraulic drive (1). At least one first and second distributing valve (6, 7) are arranged in the pressure circuit (4) such that the respective valve switch positions (61, 62, 71, 72, 73) which are suitable for the different operating phases of the hydraulic drive (1) together with the suitably driven hydraulic machine (5) allow a common movement of the work and travel cylinder (2, 3) in one or the other piston movement direction (R1, R2). For this purpose, preferably only the first and the second distributing valve (6, 7) are arranged in the pressure circuit (4). The hydraulic drive (1) requires a minimum number of components, maintains a low installation complexity, improves the energy efficiency, can be constructed in a compact manner, and can be operated in a sufficiently variable manner.

This disclosure relates to methods and apparatuses for punching workpieces. A punching tool is configured to move during a punching stroke along a stroke axis towards a workpiece to be punched. The punching tool is configured to move away from the punched workpiece during a return stroke. The punching tool includes first and second components configured to be coupled hydraulically for concurrent movement along the stroke axis. The punching tool includes a punching drive for moving the first component along the stroke axis. The punching apparatus is configured to move the second component relative to the first component at a first transmission ratio during the punching stroke. The punching apparatus is configured to move the second component relative to the first component at a second transmission ratio in response to a reaction force of the workpiece exceeding a threshold value of the punching drive during the punching stroke.

Disclosed is a piston-cylinder assembly of a hydraulic press, which includes a basic cylinder and a first and second piston. A ring cylinder is formed above the basic cylinder as a continuation of the cylinder structure. The first piston is located inside the basic cylinder in the bottom part of the basic cylinder and the second piston is located above the first piston in the top part of the cylinder structure. The piston-cylinder assembly has a first hydraulic fluid space below the first piston and a second hydraulic fluid space below the second piston and the piston-cylinder assembly includes a unified hydraulic fluid channel in flow connection to the first hydraulic fluid space in order to provide a pressure effect in the first piston and to the second hydraulic fluid space in order to provide a pressure effect in the second piston.

An actuator device includes two drive units for an actuator output element. The first drive unit has a first piston chamber and a first piston displaceable therein and also first hydraulic means for displacing the piston. The second drive unit has a second piston chamber and a second piston displaceable therein and also second hydraulic or pneumatic means for displacing the piston. The second piston is joined to the actuator output element for conjoint movement therewith and can be coupled to the first piston for thrust, so that the second piston is displaceable in an outward direction by the first piston. The first drive unit is configured for a larger thrust force than the second drive unit, while the second drive unit is designed for a greater stroke speed than the first drive unit.

The invention relates to a precision blanking press including a top, a base and tie rods and columns that operatively connect the top and the base. The precision blanking press has a press frame with a high stiffness, low mass and simple design, the press allowing the transfer of higher cutting forces during fine blanking while safely eliminating axial play between adjustment elements and at the same time improving the operational safety.

A press (1) is described, for molding an ingot made of thermoplastic or thermosetting material, comprising a basement (10) integral with risers (20), a first and a second plane (30, 40) relatively sliding with respect to the risers (20), by means of first and second hydraulic cylinders (50, 60), respectively adapted to allow opening and closing a mold formed of a first half-mold fastened to the first plane (30) and a second half-mold fastened to the second plane (40), comprising actuators (70) adapted to exert a force whose direction is equal to or opposite with respect to the direction of the force adapted to allow opening or closing the mold; the first plane (30) connected to the basement (10) is moved by means of the first hydraulic cylinders (50) and of the actuators (70), while the second plane (40) is blocked by means of a blocking apparatus (80).