The invention relates to a system (10) for remote and/or autonomous transporting at least a portion of a tree, said system (10) comprising an unmanned aerial vehicle (100), UAV, comprising, at least one means (105) for holding said at least a portion of a tree, said system comprising at least one means for detecting said at least a portion of a tree to be transported, and means for detecting at least one of the group of tree parameters: diameter of a tree, length of a tree, tree species and/or the weight of a tree, a base station (120) for communication with said means configured for transporting said at least a portion of a tree and/or said UAV (100) and means configured for directing said remotely and/autonomously UAV (100) with said at least a portion of a tree to a final destination where said final destination is depending on said detected tree parameters.

A feeding apparatus includes opposing arms pivoted to a frame, two opposing feed rollers installed in the arms as the only feed rollers for feeding a tree through the throat, hydraulic motors driving the feed rollers and at least two pressure-medium lines operating the hydraulic motors.

A saw apparatus includes a guide bar, a chain driver, and an endless cutting chain trained about the guide bar and the chain driver. The guide bar includes a first chain retention feature along at least a portion of its periphery, and the cutting chain includes a second chain retention feature configured to interact with the first chain retention feature such that movement of the second chain retention feature away from the guide bar is restricted. A timber-working device includes a frame, at least one pair of arms pivotally attached to the frame and configured to be controlled to grasp at least one tree, and the saw apparatus mounted to the frame.

A saw apparatus includes a guide bar, a chain driver, and an endless cutting chain trained about the guide bar and the chain driver. The guide bar includes a first chain retention feature along at least a portion of its periphery, and the cutting chain includes a second chain retention feature configured to interact with the first chain retention feature such that movement of the second chain retention feature away from the guide bar is restricted. A timber-working device includes a frame, at least one pair of arms pivotally attached to the frame and configured to be controlled to grasp at least one tree, and the saw apparatus mounted to the frame.

A harvester head having at least one hydraulic actuator with a cylinder and a piston. The hydraulic actuator having at least a cylinder chamber and a piston rod chamber, both chambers being connected to a hydraulic circuit. The piston separating the cylinder chamber and the piston rod chamber, a cavity provided in the piston, hydraulically connecting the cylinder chamber with the piston rod chamber and a check valve in connection with the cavity that allows hydraulic medium flow in an opening direction of the check valve.

A harvester head having at least one hydraulic actuator with a cylinder and a piston. The hydraulic actuator having at least a cylinder chamber and a piston rod chamber, both chambers being connected to a hydraulic circuit. The piston separating the cylinder chamber and the piston rod chamber, a cavity provided in the piston, hydraulically connecting the cylinder chamber with the piston rod chamber and a check valve in connection with the cavity that allows hydraulic medium flow in an opening direction of the check valve.

A method for operating forestry machinery includes providing timber units with forestry machines and an operation processor. The method also includes detecting or receiving data from an information source, where the data includes worksite preparation data, navigation data, or worksite situation data. The data is processed by the operation processor and operation parameters of the forestry machine are set based on the processing of the data. The method further includes communicating instructions to the forestry machine by the operation processor, where the instructions include the operation parameters.

A method for operating forestry machinery includes providing timber units with forestry machines and an operation processor. The method also includes detecting or receiving data from an information source, where the data includes worksite preparation data, navigation data, or worksite situation data. The data is processed by the operation processor and operation parameters of the forestry machine are set based on the processing of the data. The method further includes communicating instructions to the forestry machine by the operation processor, where the instructions include the operation parameters.

A saw chain for a cutting device of a tree-handling device, which saw chain comprises links connected to each other by connector elements, in such a way that the saw chain is an endless loop, which can be arranged to circulate in a groove arranged in a guide bar. The links, include tooth links and drive links. The tooth links comprise a cutting tooth which has a cutting edge. In front of the cutting tooth is an empty space up to the next tooth link. The invention also relates to a tree-handling device, a saw-chain blank, and a method for arranging the cutting operation of a tree-handling device.

A saw chain for a cutting device of a tree-handling device, which saw chain comprises links connected to each other by connector elements, in such a way that the saw chain is an endless loop, which can be arranged to circulate in a groove arranged in a guide bar. The links, include tooth links and drive links. The tooth links comprise a cutting tooth which has a cutting edge. In front of the cutting tooth is an empty space up to the next tooth link. The invention also relates to a tree-handling device, a saw-chain blank, and a method for arranging the cutting operation of a tree-handling device.