Vorrichtung zur Steuerung eines Gerätes, dessen Position einstellbar ist

摘要

In the field of agricultural machinery, there is a need to control the position of implements relative to eg. the ground with a high degree of accuracy. Previous arrangements for achieving this have suffered the disadvantage of providing false readings in the harsh conditions commonly encountered by agricultural equipment. The disclosure relates to an apparatus for controlling the position of a header (10) relative to the ground surface (17), the apparatus including one or more pivotable shoes (20) arranged to contact the ground and to move in dependence on changes in the ground contour. A further member (24) secured to such a pivotable shoe (20) includes a reflecting surface (26) remote from the point of contact of the shoe (20) with the ground surface (17). An emitter/receiver (29) is spaced from the reflecting surface (26) and connected to a control circuit whereby the position of the header (10) relative to the ground (17) may be measured by virtue of the position of the reflecting surface (26). The position of the header (10) relative to the ground surface (17) is then adjustable in dependence on the detected measurements, by means of various actuators (35,44,38,40) associated with the apparatus.