A spring is combined between the chassis and the pair of links arms. An electric actuator is combined between the chassis and the pair of links arms for compressing the spring with the assistance of gravity on a downward stroke of the electric actuator while lowering the pair of link arms, and wherein the pair of link arms are raised by an outward stroke of both the electric actuator and the spring.

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.

An implement having a frame for towing by an agricultural vehicle, a lifting arm pivotally connected toward a first end of the frame, a support arm pivotally connected at a first end to a second end of the arm, a working implement carried from a second end of the support arm, a support located between a first end of the lifting arm and the frame which has a working surface. The support element includes a main body with connected first and second support surfaces, a third support surface spaced from the first support surface, a first displaceable element with a contact surface and an opposed support surface, and located between the first and third support surfaces, and a second displaceable element with a first contact surface and an opposed support surface, and located between the second support surface and the third support surface.

A single solenoid-controlled electro-hydraulic liftomatic system is provided. The single solenoid-controlled electro-hydraulic liftomatic system is developed for controlling electrically, automating a hydraulic mechanism used in three-point hitch systems of tractors lifted and lowered by a mechanically controlled hydraulic mechanism. The single solenoid-controlled electro-hydraulic liftomatic system includes an actuator, a hydraulic pump, a safety element, a tank line, a valve body, a hydraulic piston, at least one solenoid valve, a piston spring, a check valve, a time-delay relay, and a button.

A three-point hitch for an agricultural tractor includes a hydraulically actuatable lifting arm, a vertically pivotable lower link, and a lifting strut arranged between the lifting arm and the lower link. The lifting strut transmits to the lower link a pivoting movement on the lifting arm. The lifting strut includes a first fastening portion articulated to the lifting arm and a second fastening portion articulated to the lower link. The second fastening portion includes first and second fastening segments which encompass the lower link in a fork-shaped manner. A bearing pin disposed between the two fastening segments extends through a slot formed in the lower link. By pivoting the lower link, the bearing pin is displaced inside the slot between a first working position and a second working position. In each position, the bearing pin is secured inside the slot by a blocking arrangement.

A link assembly for a hitch includes a first link and a second link. The second link has first and second spaced apart bores extending therethrough. A coupling member is attached to an end of the first link. The coupling member includes first and second spaced apart coupling plates. The coupling member has a load bore extending through the first and second coupling plates and has a plurality of index bores extending through the first and second coupling plates. A load pin is receivable by the load bore and the first bore, and pivotally couples the second link to the first link. An index pin is removably receivable by the second bore and a selected index bore, and the index pin is movable independently of the load pin.

An agricultural machine has a linkage system for hitching of an implement and an additional axle mounted to the linkage system. The linkage system includes at least one lift arm adjustably mounted to the chassis at an inner end and carrying a fastening device at an outer end. The additional axle is connected to at least one lift arm inboard of the fastening device. The linkage assembly may be a three-point linkage assembly having two lower lift arms, the additional axle being mounted between the lower lift arms.

A working machine has a display device including: an area display portion to display a setting area for setting the first priority value, the second priority value, and the third priority value; a first axis display portion including a first scale portion indicating the first priority value depending on a distance from the reference point; a second axis display portion including a second scale portion indicating the second priority value depending on a distance from the reference point; a third axis display portion including a third scale portion indicating the third priority value depending on a distance from the reference point; and a marker display portion to be indicated in a partial area corresponding to at least two of the first axis display portion, the second axis display portion, and the third axis display portion.

A three-point hitch hookup assist system may include a three-point hitch system. The three-point hitch system may include a lower link having a first connection about which the lower link pivots and an implement connector, a powered actuator to pivot the lower link, a first sensor coupled to the lower link to output signals indicating a manual force applied by an operator to the lower link, and a controller. The controller may output control signals to the powered actuator to cause the powered actuator to apply an assist force to the lower link based upon the sensed manual force.

A method for adjusting an orientation angle of an agricultural implement includes arranging a hitch such that an upper link and at least one lower link is articulated to a support structure of the utility vehicle, and adjusting the orientation angle based on a target length of the upper link. The target length of the upper link is determined as a function of the orientation angle and as a function of a lower link angle.