Hydraulic adjustment device

A three-point power lift of an agricultural machine, the three-point power lift comprising:

• two laterally pivotable lower links (21, 22), each of which is hydraulically transversely adjustable via a hydraulic cylinder (1, 2);
• a hydraulic control circuit for actuating the hydraulic cylinders (1, 2), the control circuit including a pressure control device (5) for generating an adjustable control pressure in dependence on an electrical control signal, and a pressure-controlled changeover valve (6) which is connected to the pressure control device (5) and, when a first control pressure value is applied, the pressure-controlled changeover valve (6) assumes a first switching position (S2) in which a first of the hydraulic cylinders (1) is connected to a pressure sink (4) and the second of the hydraulic cylinders (2) is connected to a pressure source (3), and, when a second control pressure value is applied which is higher than the first control pressure value, the pressure-controlled changeover valve (6) assumes a second switching position (S3) in which the first hydraulic cylinder (1) is connected to the pressure source (3) and the second hydraulic cylinder (2) is connected to the pressure sink (4).