Abstract: An electrohydraulic drive unit of a machine tool having a tool that can be moved up and down is provided and comprises a double-acting hydraulic cylinder-piston arrangement oriented in upright manner and having a piston projecting downwardly from the cylinder and being coupled with the tool, a valve block flanged to the cylinder at the upper end region thereof and having a servo suction valve, a hydraulic-fluid reservoir flanged to the valve block at a first hydraulic interface and a motor-pump unit having an electric motor and a hydraulic pump driven thereby and flanged to the valve block at a second hydraulic interface. A suction line, extends from the first hydraulic interface to the second hydraulic interface through the valve block.

Abstract: An electrohydraulic drive unit of a machine tool having a tool that can be moved up and down is provided and comprises a double-acting hydraulic cylinder-piston arrangement oriented in upright manner and having a piston projecting downwardly from the cylinder and being coupled with the tool, a valve block flanged to the cylinder at the upper end region thereof and having a servo suction valve, a hydraulic-fluid reservoir flanged to the valve block at a first hydraulic interface and a motor-pump unit having an electric motor and a hydraulic pump driven thereby and flanged to the valve block at a second hydraulic interface. A suction line, extends from the first hydraulic interface to the second hydraulic interface through the valve block.

Abstract: A self-pumping hydropneumatic suspension strut includes a high pressure area and a low pressure area, wherein pressurized medium is exchanged between the high pressure area and the low pressure area via a passive pump device. At least two separate channel systems with connection orifices which determine level position and are controlled depending on the position of a piston rod are provided between the high pressure area and the low pressure area. One of the channel systems can be blocked by a valve device, and wherein the suspension strut has a displacing device with a spring seat for a supporting spring. The displacing device is operated via the working movement of the piston rod.

Abstract: A self-pumping hydropneumatic suspension strut includes a high pressure area and a low pressure area, wherein pressurized medium is exchanged between the high pressure area and the low pressure area via a passive pump device. At least two separate channel systems with connection orifices which determine level position and are controlled depending on the position of a piston rod are provided between the high pressure area and the low pressure area. One of the channel systems can be blocked by a valve device, and wherein the suspension strut has a displacing device with a spring seat for a supporting spring. The displacing device is operated via the working movement of the piston rod.

Abstract: The hydraulic drive system of a machine press comprises at least two independent hydraulic drive units. In each of said hydraulic drive units at least one hydraulic cylinder, which is connected via valves and a main pressure line under supply pressure to a pump driven by a motor, raises and lowers the upper tool carrier. The rotational speed of the motor is adjustable via the numeric machine control, in which a rotational speed profile defined across the work cycle is stored. Furthermore, a pressure-limiting unit limiting the level of the supply pressure is provided, which at least during a part of the work cycle limits the supply pressure to the lower pressure of a pressure profile defined across the work cycle and stored in the numeric machine control and the actual load pressure increased by an extra amount at the at least one hydraulic cylinder.

Abstract: In a machine press having a lower and an upper tool carrier, a hydraulic drive acting on the upper tool carrier comprises at least one closed hydraulic drive system that can be switched between rapid motion and press motion, the drive system having at least one hydraulic cylinder piston unit. The hydraulic liquid of the at least one hydraulic drive system is stored in a pressure accumulator fanning the storage container, supplying the entire associated hydraulic drive system. permanently with at least a base pressure above the ambient pressure. There is no hydraulic connection whatsoever between the working chamber on the piston rod side and the working chamber on the piston side of at least one hydraulic cylinder piston unit. The upper tool carrier is pre-stressed into its upper position by a spring unit.

Abstract: The hydraulic drive system of a machine press comprises at least two independent hydraulic drive units. In each of said hydraulic drive units at least one hydraulic cylinder, which is connected via valves and a main pressure line under supply pressure to a pump driven by a motor, raises and lowers the upper tool carrier. The rotational speed of the motor is adjustable via the numeric machine control, in which a rotational speed profile defined across the work cycle is stored. Furthermore, a pressure-limiting unit limiting the level of the supply pressure is provided, which at least during a part of the work cycle 1 limits the supply pressure to the lower pressure of a pressure profile defined across the work cycle and stored in the numeric machine control and the actual load pressure increased by an extra amount at the at least one hydraulic cylinder.

Abstract: In a machine press having a lower and an upper tool carrier, a hydraulic drive acting on the upper tool carrier comprises at least one closed hydraulic drive system that can be switched between rapid motion and press motion, the drive system having at least one hydraulic cylinder piston unit. The hydraulic liquid of the at least one hydraulic drive system is stored in a pressure accumulator fanning the storage container, supplying the entire associated hydraulic drive system permanently with at least a base pressure above the ambient pressure. There is no hydraulic connection whatsoever between the working chamber on the piston rod side and the working chamber on the piston side of at least one hydraulic cylinder piston unit. The upper tool carrier is pre-stressed into the upper final position thereof by means of a spring unit.

Abstract: Valve with a displaceable actuating device that controls the movements of at least one actual sealing element for opening and closing, and the actuating device is loaded with an elastic element essentially in a perpendicular direction relative to the direction of displacement, and the longitudinal axis of the actuating device and the force exercised by the elastic element are aligned in one position of the actuating device between its two extreme positions. In order to realize a valve that can be electrically switched using minimal currents and that is characterized, in particular, by its small construction size but that is still able to achieve large regulating distances, the actuating device is a unilaterally constrained piezoelectric bending element.

Abstract: A contour-adjustable seat, particularly a vehicle or aircraft seat, has a backrest (2) and possibly lateral support pieces (4) whereby there are gas or air-inflatable cushions (5a, 5b, 5c) provided on a common flexible modular support unit (M), possibly designed as a separate component, whereby the modular support unit (M) serves as a common support surface for the cushions, which are each connected to a source of compressed air or gas via a line provided with a controllable valve, whereby each valve communicates with a control unit for air or gas pressure via a control line, and whereby a pressure sensor is provided for each cushion. Additional components for the contour adjustment system are integrated in the modular support unit, such as. valves for cushions and/or for pressure sensors, to obtain a system that is simple in the assembly of the seat and is also well-suited for possible retrofitting, and subsequently requires less space and is lighter than conventional systems.

Abstract: Valve with a displaceable actuating device that controls the movements of at least one actual sealing element for opening and closing, and the actuating device is loaded with an elastic element essentially in a perpendicular direction relative to the direction of displacement, and the longitudinal axis of the actuating device and the force exercised by the elastic element are aligned in one position of the actuating device between its two extreme positions. In order to realize a valve that can be electrically switched using minimal currents and that is characterized, in particular, by its small construction size but that is still able to achieve large regulating distances, the actuating device is a unilaterally constrained piezoelectric bending element.