A header for an agricultural harvester including a continuous loop knife and a sensor for sensing conditions of a plurality of knives of the continuous loop knife in increments comprising non-adjacent groups of one or more knives, whereby substantially all of the plurality of knives is sensed after a plurality of cycles of the continuous knife past the sensor. With the header so equipped, a timely determination of wear or damage to the knives in a loop knife cutting system can be made, so that damaged knives may be replaced before significant deterioration of the cutting performance occurs.

A cutting tool for clearing plant growth. The clearing tool includes a power transmission apparatus. An elongated part is coupled to the transmission to rotate around a longitudinal axis of the elongated part and having at least one thread that rises toward the transmission and the diameter of which decreases from an end of the elongated part coupled to the transmission to the end of the elongated part that is at a distance from the transmission. Guide parts are arranged around the elongated part to extend in the direction of the longitudinal axis of the elongated part. A blade part is arranged at the end of the elongated part coupled to the transmission. The elongated part, which, while targeted in a longitudinal direction toward the plant growth, is arranged to cut the plant growth when being rotated, wherein the threads transport the plant growth toward the blade part guided by the guide parts and cut the plant growth with the blade part.

The invention relates to an improved head for harvesting of trees. In particular, the head according to the invention is an improvement of a head for harvesting of trees as disclosed in European Patent EP2515628, which state of art is hereby incorporated by reference. In the known head, the balance between the saw pressure and the saw speed is controlled by the oil pressure at the inlet port of the hydraulic motor. This has the drawback that the saw pressure is depending on the saw speed. It is the aim of the invention to provide an improved head for harvesting trees, wherein the saw pressure is constant and independent of the saw speed.

A system for monitoring an extractor fan of an agricultural harvester includes an extractor fan having a shaft configured to be coupled to a rotational drive source for rotationally driving the shaft, a fan hub coupled to a lower shaft end of the shaft such that rotation of the shaft rotationally drives the fan hub about a fan hub axis, with the fan hub extending between an upstream side and a downstream side along the fan hub axis, and fan blades coupled to and extending radially outwardly from the fan hub. The system further includes a sensor that generates data indicative of acceleration of the extractor fan. Additionally, the system includes a computing system that determines an acceleration of the extractor fan based at least in part on the data, and determines whether the extractor is imbalanced based at least in part on the acceleration of the extractor fan.

A system for monitoring an extractor fan of an agricultural harvester includes an extractor fan having a shaft configured to be coupled to a rotational drive source for rotationally driving the shaft, a fan hub coupled to a lower shaft end of the shaft such that rotation of the shaft rotationally drives the fan hub about a fan hub axis, with the fan hub extending between an upstream side and a downstream side along the fan hub axis, and fan blades coupled to and extending radially outwardly from the fan hub. The system further includes a sensor that generates data indicative of acceleration of the extractor fan. Additionally, the system includes a computing system that determines an acceleration of the extractor fan based at least in part on the data, and determines whether the extractor is imbalanced based at least in part on the acceleration of the extractor fan.

A cutting apparatus for a header of an agricultural harvester includes a first wheel and a second wheel. A drive source is configured to selectively drive the first wheel in a clockwise direction or an anticlockwise direction. A knife carrier, including a loop having a running side and a knife-carrying side, is tensioned around the first and second wheels for transmitting torque from the drive source to rotate the wheels and the knife carrier. A plurality of knives cut crop mounted to the knife-carrying surface of the knife carrier. A sensor monitors operation of the knives.

The cutting system includes knives attached to a continuously moving belt-type carrier. The carrier motion moves the knives past stationary counterknife fingers. Each knife is pivotably connected to the platform portion of a support bracket having also a wall portion that is fixed to the belt-type carrier. The knife is furthermore coupled to the bracket by a reversible force coupling that maintains the knife in a forwardly oriented operational position when the knife is subjected to lateral forces which exert a torque on the knife that remains below a predefined limit, encountered when the knife is cutting stalks or meeting small obstructions. When the knife is subjected to lateral forces resulting in a torque above the predefined limit, the force coupling is configured to be disengaged in a reversible manner, enabling the knife to pivot about a rotation axis towards a non-operational position.