Trailed or semi mounted implement guide - has sensors to detect deviation from datum line and cause correction through hydraulic jack

摘要

An axle (12) of a towed or semi mounted implement pivots about a vertical axis passing through the centre of the axle. The implement is connected to the tractor by a towing link having vertical pivot connections to tractor and implement and which can move transversely relative to the tractor. Sensors (6) carried by a parallelogram linkage are suspended over the guide line (14). An error causes movement of link (8) to operate a valve causing a correcting movement of jack (4) connected between the implement and the towing link.