A height adjustable hitch receiver is disclosed and described.

A work machine includes: a boom; a dipper stick attached to a distal end of the boom; a bucket attached to a distal end of the dipper stick; and a loading determination unit configured to determine that an operation of the work machine is a loading operation for loading an excavated matter into a loading target under a condition that the bucket moves across a reference level.

There is described a method for confirming delivery of bulk material from a bed of a dump truck based on hydraulic pressure. The dump truck has a driving device moving the bed between a rest position and a delivery position. The method generally having: using a hydraulic pressure sensor, measuring a plurality of hydraulic pressure values indicative of pressure of a hydraulic fluid of the driving device as the bed is moved; and using a controller communicatively coupled to the hydraulic pressure sensor: monitoring a slope at which at least some of the plurality of hydraulic pressure values vary over a given period of time; and generating a delivery confirmation indicative that a delivery of the bulk material has occurred based on a comparison between said monitored slope and a delivery slope threshold.

There is described a method for confirming delivery of bulk material from a bed of a dump truck based on hydraulic pressure. The dump truck has a driving device moving the bed between a rest position and a delivery position. The method generally having: using a hydraulic pressure sensor, measuring a plurality of hydraulic pressure values indicative of pressure of a hydraulic fluid of the driving device as the bed is moved; and using a controller communicatively coupled to the hydraulic pressure sensor: monitoring a slope at which at least some of the plurality of hydraulic pressure values vary over a given period of time; and generating a delivery confirmation indicative that a delivery of the bulk material has occurred based on a comparison between said monitored slope and a delivery slope threshold.

Hydraulic valve circuitry adapted for hydraulic connection to a lift truck having a mast and at least one lift cylinder for alternately raising and lowering the mast. The hydraulic assembly is also adapted for hydraulic connection to an attachment to the lift truck, the attachment having opposed clamps actuated by respective clamp cylinders. The hydraulic assembly preferably comprises a valve circuit capable of causing the at least one lift cylinder to be an accumulator.

Hydraulic valve circuitry adapted for hydraulic connection to a lift truck having a mast and at least one lift cylinder for alternately raising and lowering the mast. The hydraulic assembly is also adapted for hydraulic connection to an attachment to the lift truck, the attachment having opposed clamps actuated by respective clamp cylinders. The hydraulic assembly preferably comprises a valve circuit capable of causing the at least one lift cylinder to be an accumulator.

In an unloaded state of the bucket (3), a control device (30) calculates an unloaded moment (M.sub.0) around a hinge pin G from the pressure of the lift arm cylinder that is detected by pressure sensors (15a, 15b), the angle of a lift arm that is detected by a lift arm angle sensor 14, and dimension data extracted from a vehicle body information database (35). In a loaded state of the bucket, the control device calculates a loaded moment (M.sub.1) around the hinge pin G from the pressure of the lift arm cylinder, the angle of the lift arm, and the dimension data extracted from the vehicle body information database. The control device calculates the load (W) on the bucket by dividing the difference between the unloaded moment and the loaded moment by the horizontal distance (L.sub.w) between the hinge pin and the gravity center position of the bucket.

In an unloaded state of the bucket (3), a control device (30) calculates an unloaded moment (M.sub.0) around a hinge pin G from the pressure of the lift arm cylinder that is detected by pressure sensors (15a, 15b), the angle of a lift arm that is detected by a lift arm angle sensor 14, and dimension data extracted from a vehicle body information database (35). In a loaded state of the bucket, the control device calculates a loaded moment (M.sub.1) around the hinge pin G from the pressure of the lift arm cylinder, the angle of the lift arm, and the dimension data extracted from the vehicle body information database. The control device calculates the load (W) on the bucket by dividing the difference between the unloaded moment and the loaded moment by the horizontal distance (L.sub.w) between the hinge pin and the gravity center position of the bucket.

A controller 21 mounted on a work machine calculates a target carried load representing a target value for a carried load carried by the work machine on the basis of loadage of a transportation machine in case the loadage is changed, calculates a minimum integration load value depending on the magnitude of the calculated target carried load, and calculates the loadage by integrating the carried load in case it is determined that a work implement has performed a loading operation on the transportation machine and in case the calculated carried load is equal to or larger than the minimum integration load value.

A controller 21 mounted on a work machine calculates a target carried load representing a target value for a carried load carried by the work machine on the basis of loadage of a transportation machine in case the loadage is changed, calculates a minimum integration load value depending on the magnitude of the calculated target carried load, and calculates the loadage by integrating the carried load in case it is determined that a work implement has performed a loading operation on the transportation machine and in case the calculated carried load is equal to or larger than the minimum integration load value.