Abstract: A disc harrow composed of one or more disc gangs has a subframe coupled to the disc gangs to move the disc gangs in response to variations in farmland terrain to limit the impact of obstructions when encountered during the harrowing process. When the obstruction is cleared, the subframe automatically returns the disc gangs to their pre-obstruction position. In addition to reducing the potentially-damaging impact of obstructions, the subframe also maintains a more consistent reel depth during undulations or changes in the farmland terrain, such as during harrowing of slopes or unleveled fields such as valleys, near waterways, and along fence rows.

Abstract: A motor grader has an ordinary direction of travel, has a forward end and a rearward end as defined by the ordinary direction of travel, and has two opposed sides. At least one set of front wheels is steerably mounted on the opposed sides of the motor grader adjacent the forward end, with one front wheel in each set mounted on each opposed side of the motor grader. At least one front wheel in each set of front wheels is movably mounted to the motor grader and can be selectively positioned such that each front wheel on one side of the motor grader is further away from the rearward end than the other front wheel in that set.

Abstract: A motor grader has a control system in which the manner of controlling the blade position differs depending upon whether the blade is to be moved vertically or is to be maintained at a generally constant level and cross slope. First and second hydraulic valves control the flow of hydraulic fluid to the first and second hydraulic cylinders which raise and lower respective ends of the blade. An inclinometer provides an inclinometer output indicating the inclination of the blade along its length with respect to horizontal. The control system includes a first hydraulic cylinder position sensor for determining the extension of the first hydraulic cylinder. The control system further includes a control that is responsive to a control input specifying the desired height and cross slope of the blade, to the first hydraulic cylinder position sensor, and to the inclinometer output. The control provides valve control signals to the first and second hydraulic valves.

Abstract: A tractor scraper hitch steering and suspension system wherein a tractor drive wheel axle frame is pivotally connected to a tractor main frame to permit vertical movement of the tractor drive wheels relative to the tractor. Two hydraulic cylinders are pivotally connected between the tractor drive wheel axle frame and a cross arm forming a part of a hitch assembly that secures the tractor to the scraper. The hydraulic cylinders dampen vertical bounce movement that occurs during operation and control tilting or rolling motion between the tractor portion and the scraper portion that occur about their common longitudinally extending axis. A locking brake is provided to resist vertical motion of the tractor drive wheel axle frame to stabilize the depth of a cutting edge of the scraper during operation and obtain a steady depth of cut.

Abstract: A land plane for leveling or grading the surface of a land area including a frame having front and rear wheel assemblies, a center section and two end sections. A plurality of grader blades are supported below the center section which in turn may be raised away from and lowered towards the ground surface by pivoting the end sections of the frame with respect to the center section. Adjustable braces correct warps and distortion in the frame and permit accurate setting of the alignment and angular disposition of the blades with respect to the ground surface. Steering of the plane is controlled through a fluid system which coordinates the steering actions of the front and rear wheel assemblies and, alternatively, permits the rear wheel assembly to be steered independent of the front wheel assembly.