| 摘要 |
A drawbar for agricultural ground working implements includes a main frame having a front and rear end. A hitch is mounted on the front end of the frame for connecting to a towing vehicle. On the rear end of the frame there is mounted a plurality of first pivots oriented for rotation about a generally horizontal axis. A beam connected to the first pivots is rotatable between a field position and a transport position. The beam mounts a pair of second pivots having axes wherein the orientation of the axes rotate with the beam. A pair of main booms are mounted on the respective second pivots for rotation between the field position and the transport position. Mounted on the main boom is a pivot shaft for mounting a secondary boom while permitting relative rotation of the secondary to the main boom. In the transport position the booms extend rearwards and the pivot shaft is rotatable about an upright axis. In the field position the booms extend in respective lateral directions and the pivot shaft is rotatable about an axis extending rearwards. A plurality of wheels support the drawbar in the transport and field positions. A swing arm mounted with a hinge extends laterally outward from each respective main boom for supporting a road wheel. A link connects the swing arm to the respective pivot shaft for steering the respective road wheel in response to rotation of the respective secondary boom in relation to the respective main boom.
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