Abstract: A swather tractor has a pair of driven ground wheels at one end where a header is supported and a pair of steerable wheels at the other end for supporting the tractor. The driven ground wheels are hydraulically driven so that an operator controlled steering control is arranged to control a differential in rate of supply of hydraulic fluid to control a relative speed of rotation of the driven wheels and thus a turning direction of the tractor. The steerable wheels have a steering system that is operable in response to the steering control to positively steer the steerable wheels and there is provided an arrangement to deactivate the steering system at large turns so that the steerable wheels are free to castor.

Abstract: A swather tractor has a pair of driven ground wheels at one end where a header is supported and a pair of steerable wheels at the other end for supporting the tractor. The driven ground wheels are hydraulically driven so that an operator controlled steering control is arranged to control a differential in rate of supply of hydraulic fluid to control a relative speed of rotation of the driven wheels and thus a turning direction of the tractor. The steerable wheels have a steering system that is operable in response to the steering control to positively steer the steerable wheels and there is provided an arrangement to deactivate the steering system at large turns so that the steerable wheels are free to castor.

Abstract: A tractor has front wheels mounted on the frame at fixed angles and a pair of rear wheels each mounted on a respective castor assembly. Each of the castor assemblies has a vertical pivot axis mounted in a swivel support of an axle of the frame and a bottom transverse tubular member connected to a pair of parallel forks carrying at a lower ends the transverse axle of the wheel. The mounting link includes a torsion spring defined by a rod attached to the forks which passes though a sleeve containing a resilient elastomeric spring of the tubular member allowing spring suspension pivotal movement of the upper ends of the forks relative to the bottom transverse member about an axis parallel to the wheel axis.

Abstract: A tractor has front wheels mounted on the frame at fixed angles and a pair of rear wheels each mounted on a respective castor assembly. Each of the castor assemblies has a vertical pivot axis mounted in a swivel support of an axle of the frame and a bottom transverse tubular member connected to a pair of parallel forks carrying at a lower ends the transverse axle of the wheel. The mounting link includes a torsion spring defined by a rod attached to the forks which passes though a sleeve containing a resilient elastomeric spring of the tubular member allowing spring suspension pivotal movement of the upper ends of the forks relative to the bottom transverse member about an axis parallel to the wheel axis.

Abstract: 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.

Abstract: 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.