Patent attributes
A tractor has hydraulically driven wheels at a cab end and castor wheels at an engine end. It can be driven cab forward in a working mode with a header on the forward end. It is rotated to engine forward in the transport position for more stable higher speed travel. The driven wheels are driven by hydraulic motors each having their own drive pump the output of which is controlled by a cam plate. There is provided an automatic steering system having a guidance controller arranged to receive GPS position information and feed back signals and to generate output for controlling a hydraulic control valve for controlling flow in hydraulic fluid for a double acting hydraulic control cylinder arranged to actuate pivotal movement of the steering link member independently of the steering shaft.