A harvesting machine comprises a main drive, a hydraulic auxiliary drive which can be acted upon by pressurized fluid via a directional valve (33), and a crop conveyor (6) which can be driven by the main drive in a normal conveying direction and by the auxiliary drive in an opposite direction opposite to the normal ...

An agricultural machine comprises a heightadjustable working tool, a source and sink for a pressurised fluid and a positioning cylinder which can be optionally connected to the source and sink for vertical adjustment of the working tool. A throttle point and a non-return valve are connected parallel to one another ...