Abstract: In a hydraulic adjustment device, preferably for transverse adjustment of the lower links of a three-point power lift on an agricultural machine, with two selectively controllable hydraulic cylinders and a hydraulic control circuit for actuating them, a control circuit with a pressure control device for generating an adjustable control pressure in dependence on an electrical control signal is provided, and a pressure-controlled changeover valve is connected to the pressure control device and, when a first control pressure value is applied, assumes a first switching position in which a first cylinder is connected to a pressure sink and the second cylinder is connected to a pressure source, and, when a second control pressure value is applied which is higher than the first control pressure value, assumes a second switching position in which the first cylinder is connected to the pressure source and the second cylinder is connected to the pressure sink.

Abstract: A hydraulic unit includes two pressure connections for supplying devices, in particular hydraulic rescue devices, including a first hydraulic circuit with a first pump arrangement and a first pressure connection and a second hydraulic circuit with a second pump arrangement and a second pressure connection, wherein the pump arrangements are driven at the same time by a common drive, and wherein by a first valve switch the first hydraulic circuit can be connected to the second hydraulic circuit and by a second valve switch the second hydraulic circuit can be connected to the first hydraulic circuit. The valve switches include a spring acting in the direction of an initial position and from the first hydraulic circuit or from the second hydraulic circuit a first control line runs to the first valve switch and from the second hydraulic circuit or from the first hydraulic circuit a second control line runs to the second valve switch.

Abstract: A hydraulic unit includes two pressure connections for supplying devices, in particular hydraulic rescue devices, including a first hydraulic circuit with a first pump arrangement and a first pressure connection and a second hydraulic circuit with a second pump arrangement and a second pressure connection, wherein the pump arrangements are driven at the same time by a common drive, and wherein by a first valve switch the first hydraulic circuit can be connected to the second hydraulic circuit and by a second valve switch the second hydraulic circuit can be connected to the first hydraulic circuit. The valve switches include a spring acting in the direction of an initial position and from the first hydraulic circuit or from the second hydraulic circuit a first control line runs to the first valve switch and from the second hydraulic circuit or from the first hydraulic circuit a second control line runs to the second valve switch.

Abstract: A geared compression air starter having a lead rotor, a driven rotor and a hollow shaft. A driven trunnion of the driven rotor engages with external teeth thereof into external teeth of the hollow shaft to connect the driven rotor with the hollow shaft. A freewheeling unit couples the hollow shaft with an axially displaceable engagement shaft so that the central axes of the engagement and of the hollow shaft can be positioned coaxially with respect to a central axis of the lead rotor. An engagement cylinder is connected with the engagement shaft by means of a piston rod which extends through the lead rotor, and the engagement cylinder is integrated into an end cover of the starter housing.

Abstract: A pneumatic starter arrangement includes a pneumatic actuator having a piston supporting for axial displacement a starter pinion to engage or disengage a flywheel gear of an internal combustion engine. A pressure air source is connected to the actuator via a supply branch conduit including a pilot valve. A starter motor which rotates the starter pinion is connected to the pressure air supply via a main control valve. To insure flawless engagement of the starter pinion with the flywheel gear, a bypass conduit with a relief valve is connected between the supply branch conduit and the starter motor. The main control valve is normally in its closed position and is controlled by a switching conduit leading to a port in the pneumatic actuator so that when the piston of the actuator displaces the starter pinion in its fully engaged position, the main control valve is switched on and the starter motor is activated.