A header is supported by a pair of hydraulic float cylinders, where a float pressure to the cylinders is directly controlled by an electronic control supplying a variable control signal to a PPRR valve arrangement to maintain the float pressure at a predetermined value. At the set pressure a predetermined lifting force is provided to the header. A position sensor is used to generate an indication of movement and/or acceleration and/or velocity. The electronic control is arranged, in response to changes in the sensor signal, to temporarily change the control signal to vary the lifting force and thus change the dynamic response of the hydraulic float cylinder. A lift force greater than that required to lift the header can be provided by a lift cylinder and can be opposed in a controlled manner to apply a controlled downforce by the back of the same cylinder or by a separate component.

A header is supported by a pair of hydraulic float cylinders, where a float pressure to the cylinders is directly controlled by an electronic control supplying a variable control signal to a PPRR valve arrangement to maintain the float pressure at a predetermined value. At the set pressure a predetermined lifting force is provided to the header. A position sensor is used to generate an indication of movement and/or acceleration and/or velocity. The electronic control is arranged, in response to changes in the sensor signal, to temporarily change the control signal to vary the lifting force and thus change the dynamic response of the hydraulic float cylinder. A lift force greater than that required to lift the header can be provided by a lift cylinder and can be opposed in a controlled manner to apply a controlled downforce by the back of the same cylinder or by a separate component.

The present invention relates to mobile machinery such as an agricultural tractor comprising a three-point hitch for the connection and use of working implements cultivating or excavating the earth and other duties involved in the industry of farming or grading excavation. The disclosed invention modifies and improves the conventional three-point hitch in use today. The disclosed invention modifies the three-point hitch by adding extending and retracting implement-actuators attachable to the existing bottom-lift-arms, therefore supplanting, but still using the existing bottom-lift-arms on the three-point hitch. The implement-actuators assist the implement in correcting the implements centerline when the tractor centerline is off a predetermined centerline path. In addition, the extending of the implement-actuators proportionally, inversely and simultaneously can correct the pivot point of the implement to match the pivot point of the tractor while the tractor performs turns during the working use of the implement.

The present invention relates to mobile machinery such as an agricultural tractor comprising a three-point hitch for the connection and use of working implements cultivating or excavating the earth and other duties involved in the industry of farming or grading excavation. The disclosed invention modifies and improves the conventional three-point hitch in use today. The disclosed invention modifies the three-point hitch by adding extending and retracting implement-actuators attachable to the existing bottom-lift-arms, therefore supplanting, but still using the existing bottom-lift-arms on the three-point hitch. The implement-actuators assist the implement in correcting the implements centerline when the tractor centerline is off a predetermined centerline path. In addition, the extending of the implement-actuators proportionally, inversely and simultaneously can correct the pivot point of the implement to match the pivot point of the tractor while the tractor performs turns during the working use of the implement.

A boom suspension system may comprise a center frame operably connected to a main frame with linkages configured for vertical movement. A sensor may be operably connected to a pair of boom structures, which may extend laterally outward from opposing sides of the center frame. A controller may be configured to receive input data from the sensor and determine forces or flow rate to tilt cylinders, which may be coupled between each boom structure and the center frame. Each tilt cylinder may be operably connected to a hydraulic circuit, which may comprise a flow control mode and a pressure control mode determined by the controller. The hydraulic circuit may comprise a first set of valves in parallel with a second set of valves. Each set of valves may comprise a solenoid valve in series with a pressure regulating valve and a pressure sensor disposed on either side of each solenoid valve.

A boom suspension system may comprise a center frame operably connected to a main frame with linkages configured for vertical movement. A sensor may be operably connected to a pair of boom structures, which may extend laterally outward from opposing sides of the center frame. A controller may be configured to receive input data from the sensor and determine forces or flow rate to tilt cylinders, which may be coupled between each boom structure and the center frame. Each tilt cylinder may be operably connected to a hydraulic circuit, which may comprise a flow control mode and a pressure control mode determined by the controller. The hydraulic circuit may comprise a first set of valves in parallel with a second set of valves. Each set of valves may comprise a solenoid valve in series with a pressure regulating valve and a pressure sensor disposed on either side of each solenoid valve.

An agricultural vehicle having a chassis, wheels, a power unit, and a header. The header has a center section, at least one wing section extending laterally from the center section, and a wing section support. The center section is movable relative to the chassis, the wing section is movable relative to the center section, and the wing support is movable relative to the wing section. The combine has a control system that is configured to determine that the combine is configured to drive at a road-driving speed, and in response to such determination: operate a center section actuator to move the center section to a raised center section position, operate a wing section actuator to move the wing section to a raised wing section position, and operate a wing support actuator to move the wing support to a raised wing support position.

An agricultural harvester comprises a feederhouse pivotally attached to a chassis, where the feederhouse defines a conduit for conveying crop material rearwardly from a front opening. A header interface frame is pivotally mounted to the feederhouse over the front opening to permit header pitch adjustment around a pitch adjustment axis. Upper and lower linear actuators are connected on one side of the feederhouse between the feederhouse and interface frame to control the pitch adjustment.

An agricultural harvester comprises a feederhouse pivotally attached to a chassis, where the feederhouse defines a conduit for conveying crop material rearwardly from a front opening. A header interface frame is pivotally mounted to the feederhouse over the front opening to permit header pitch adjustment around a pitch adjustment axis. Upper and lower linear actuators are connected on one side of the feederhouse between the feederhouse and interface frame to control the pitch adjustment.

A method for determining a mass of an implement attached to a vehicle includes providing a powerlift having at least one upper link and one lower link, a support structure, and the implement. The method also includes defining an angle (ψ) between the upper link and a vehicle horizontal line, an angle (φ) between the lower link and a vehicle horizontal line, an angle of inclination (θ) of a vehicle horizontal line relative to a terrestrial horizontal line, a path (AK) that represents a connection along the lower link between the support structure and the implement, and a force (F.sub.E) impinging on a connection between the upper link and the implement and acting along the upper link. The mass is determined as a function of at least one of the angle (ψ), the angle (φ), the angle of inclination (θ), the path (AK), and the force (F.sub.E).