Depth control for beet harvester - has sensor to control valve for jack which raises and lowers discs whose working depth is regulated by remote hydraulic unit

摘要

The beet harvester has a powered wheeled chassis, including steerable front wheels. A short stroke low pressure hydraulic jack inserts the plough discs into the ground of raising the beet. A sensor (19) slides along the ground and, through a system of links and levers, varies the position of a needle valve (18) which regulates the pressure fed from a pump to the jack. The working depth of the discs is varied by an hydraulic remote control comprising a handle (27) which, via a screw jack, causes displacement from - or allows displacement intt - a cylinder (26). Cylinder (26) is connected by a flexible pipe to jack (24) and varies the vertical distance between the foot of the sensor and its mounting beam (23).