A housing (100) for housing hydraulic components, wherein the hydraulic components are configured for operating a hitch mechanism of a tractor, is a single-body component that is configured to house a plurality of valve mechanism and a reciprocating piston therein. The housing (100) comprises cavities for locating valve mechanisms therein and a cylinder (110) for accommodating a reciprocating piston (210). The housing (100) together with a plurality of valve mechanisms (122, 124, 126, 128, 130, 132) disposed in corresponding cavities, forms a predetermined hydraulic circuit (1000). The hydraulic circuit (1000) has minimum number of leakage joints, minimizes number of components and therefore assembly and machining operations.

A housing (100) for housing hydraulic components, wherein the hydraulic components are configured for operating a hitch mechanism of a tractor, is a single-body component that is configured to house a plurality of valve mechanism and a reciprocating piston therein. The housing (100) comprises cavities for locating valve mechanisms therein and a cylinder (110) for accommodating a reciprocating piston (210). The housing (100) together with a plurality of valve mechanisms (122, 124, 126, 128, 130, 132) disposed in corresponding cavities, forms a predetermined hydraulic circuit (1000). The hydraulic circuit (1000) has minimum number of leakage joints, minimizes number of components and therefore assembly and machining operations.

A method of operating a variable displacement pump in a pressurized fluid supply system for an agricultural vehicle, including maintaining a constant displacement of the pump as rotational speed of the input drive to the pump increases to a first value of 1500 rpm and thereafter adjusting the displacement of the pump to maintain a constant output fluid flow 230 L/min or reduced flow as rotational speed of the input drive to the pump increases beyond the first value to a maximum value of 2100 rpm.

A method for determining a mass of an implement includes providing a rear powerlift having at least one upper link and at least one lower link and a support structure disposed at the rear of a utility vehicle. The method includes defining an angle (Ψ) between the upper link and a vehicle horizontal line, an angle (φ) between the lower link and the vehicle horizontal line, an angle of inclination (θ) of a vehicle horizontal line relative to a terrestrial horizontal line, a path (LV) representative of a connection along the lower link between the support structure and the implement, and a force (F.sub.U) impinging on a connection between the upper link and the implement and acting along the upper link. The mass is determined by at least one of the angle (Ψ), the angle (φ), the angle of inclination (θ), the path (LV), and the force (F.sub.U).

A method for determining a mass of an implement includes providing a rear powerlift having at least one upper link and at least one lower link and a support structure disposed at the rear of a utility vehicle. The method includes defining an angle (Ψ) between the upper link and a vehicle horizontal line, an angle (φ) between the lower link and the vehicle horizontal line, an angle of inclination (θ) of a vehicle horizontal line relative to a terrestrial horizontal line, a path (LV) representative of a connection along the lower link between the support structure and the implement, and a force (F.sub.U) impinging on a connection between the upper link and the implement and acting along the upper link. The mass is determined by at least one of the angle (Ψ), the angle (φ), the angle of inclination (θ), the path (LV), and the force (F.sub.U).

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).

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).

The invention relates to a system for adjusting the height of an agricultural implement, including an arm that can be controlled so as to raise and lower the implement; a height measuring sensor mounted on the arm and positioned in front of the implement in the direction of travel of the vehicle equipped with the arm. A calculator configured to provide a control set point for the height of the arm on the basis of the measurements obtained by the sensor, wherein the sensor is a light screen device formed by an emitter in the form of a column of light sources and a receiver in the form of a column of photoreceptors. The emitter and the receiver are mounted on the arm facing one another and extending along their longitudinal axis, perpendicularly to the ground, in order to measure the height of plants located therebetween.

Agricultural implements and hydraulic circuits for agricultural implements are disclosed herein. An agricultural implement includes a fluid source, a plurality of fluid demand devices, a delivery control valve, and a priority valve. The fluid source is configured to supply hydraulic fluid. The plurality of fluid demand devices are each configured to receive hydraulic fluid supplied by the fluid source during operation of the agricultural implement. The delivery control valve is fluidly coupled between the fluid source and a first fluid demand device. The delivery control valve is configured to selectively deliver hydraulic fluid supplied by the fluid source to the first fluid demand device during operation of the agricultural implement. The priority valve is fluidly coupled between the delivery control valve and the first fluid demand device.

An apparatus for attachment to a tractor the apparatus comprising a primary implement and at a first end, connections suitable to connect to the three point linkage of the tractor and at a second end, connections suitable to connect to the three point hitch points of a secondary implement.