摘要 |
An arrangement for controlling the lifting mechanism of a tractor or a harvester or a harvester combine comprising a hydraulic actuator (17) connected to the lifting mechanism and controlled by a control valve (19) leaving a hydraulically controlled spool arranged in the bridge diagonal (27-19-27') of a hydraulic bridge circuit (23, 24, 25, 26), in the bridge branches of which two actual force value transducers (41, 42) for generating hydraulic signals proportional to the position of the lifting mechanism and desired force value setting means (32, 52) are respectively located for controlling the hydraulically controlled valve (19). An additional control valve (33) or throttle unit (53a) is provided for selecting one or both of the actual force transducers and if desired for controllably mixing the actual force signals.
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