Root crop harvester position control - has probe which follows ground contours and delivers signal to valve in hydraulic circuit of piston-cylinder unit

摘要

The working height of a root crop harvester is controlled by a probe which follows the ground contours its movements being transmitted to a control valve. This control valve is in the hydraulic circuit of the piston cylinder unit (2) In the lifting direction which raises and lowers the harvester, the unit is acted upon by the pressure of the hydraulic circuit, the control valve having a variable flow section which alters in response to signals from the probe. A line passes from the pressure supply of the hydraulic circuit to the piston-cylinder and from there, there is a line to the control valve.