A joint element provided with a swing dampener element and comprising a first joint part, a second joint part, and a swing dampener brake. The second joint part comprises a second end part which is detachably fixed to a first end part of the second joint part by a joint part coupling which is adapted to allow the second end part to be moved in an axial direction to a detached position in relation to the first end part, the detached position allowing replacement of active components of the swing dampener brake while the first end part remains bearing-mounted to the first joint part, the active components of the swing dampener brake comprising at least one first brake disc member and at least one second brake disc member.

A hydraulic actuator includes two or more cylinder parts that nest inside each other, each cylinder part including a piston and piston rod forming an operating element and a cylindrical component, inside which the operating element is arranged, the piston of the inner cylinder part being inside the piston rod of the outer cylinder part, chambers formed for each cylinder part, a pressure-medium feed arrangement creating work-movement in the operating element by the pressure medium led to the chambers, a pressure-difference-controlled valve controlling operation of the hydraulic actuator between a first ducting and a second ducting, controlling the feed of the pressure medium among the chambers and a pressure-difference-controlled spool valve including a housing, connecting chambers and a spool arranged to move backwards and forwards in the housing to open and close the connections creating a work movement alternately by the operating element of the inner or outer cylinder part.

A hydraulic actuator includes two or more cylinder parts that nest inside each other, each cylinder part including a piston and piston rod forming an operating element and a cylindrical component, inside which the operating element is arranged, the piston of the inner cylinder part being inside the piston rod of the outer cylinder part, chambers formed for each cylinder part, a pressure-medium feed arrangement creating work-movement in the operating element by the pressure medium led to the chambers, a pressure-difference-controlled valve controlling operation of the hydraulic actuator between a first ducting and a second ducting, controlling the feed of the pressure medium among the chambers and a pressure-difference-controlled spool valve including a housing, connecting chambers and a spool arranged to move backwards and forwards in the housing to open and close the connections creating a work movement alternately by the operating element of the inner or outer cylinder part.

A method and system for controlling a power-transmission gear in a forest machine having a harvester head includes measuring a selected property of at least two trees with aid of observation means on a basis of electromagnetic radiation at a distance from the trees being measured to create measurement data. The power-transmission gear is controlled by software on the basis of the measurement data to change a state of the power-transmission gear to optimize energy required to perform an operation of an operating device. The operating device uses the energy transmitted by the power-transmission gear (after the change in state of the power-transmission gear so that operation of the operating device create a change in the attitude, location, or state of the harvester head.

A method and system for controlling a power-transmission gear in a forest machine having a harvester head includes measuring a selected property of at least two trees with aid of observation means on a basis of electromagnetic radiation at a distance from the trees being measured to create measurement data. The power-transmission gear is controlled by software on the basis of the measurement data to change a state of the power-transmission gear to optimize energy required to perform an operation of an operating device. The operating device uses the energy transmitted by the power-transmission gear (after the change in state of the power-transmission gear so that operation of the operating device create a change in the attitude, location, or state of the harvester head.

Embodiments described herein are directed to an apparatus for determining a direction in which a tree will fall and a method for using the apparatus. The apparatus may comprise a plate including a substantially straight edge suitable for alignment with a vertex formed by a top cut and a bottom cut of a notch cut into a tree and a substantially level bottom surface suitable for stable placement upon the bottom cut of the notch. In some embodiments, the plate may define an internal cavity sized to accommodate a laser light generator. In other embodiments, a rotatable housing including a cavity sized to accommodate a laser light generator may be adjoined to the plate. Embodiments may permit a laser light generator contained within the cavity or the housing to emanate a beam of laser light in a direction that is substantially perpendicular to the substantially straight edge of the plate.

Embodiments described herein are directed to an apparatus for determining a direction in which a tree will fall and a method for using the apparatus. The apparatus may comprise a plate including a substantially straight edge suitable for alignment with a vertex formed by a top cut and a bottom cut of a notch cut into a tree and a substantially level bottom surface suitable for stable placement upon the bottom cut of the notch. In some embodiments, the plate may define an internal cavity sized to accommodate a laser light generator. In other embodiments, a rotatable housing including a cavity sized to accommodate a laser light generator may be adjoined to the plate. Embodiments may permit a laser light generator contained within the cavity or the housing to emanate a beam of laser light in a direction that is substantially perpendicular to the substantially straight edge of the plate.

A feed roller assembly of a harvester head of a forestry machine includes a pivoted arm operated by a hydraulic cylinder and a feed roller and one operating device attached to the pivoted arm having an attachment hub driving the feed roller, the feed roller includes at least one attachment flange, at least two toothed discs, spacer pieces between at least the attachment flange and the toothed discs, attachment bolts connecting the attachment flange, the toothed discs, and the spacer pieces to form the feed roller as a bolted construction, and a cleaning comb attached to the arm for cleaning gaps formed between each pair of components when the feed roller is rotating.

An aerial saw is provided, including an elongated arm having a proximal end and a distal end; a saw blade rotatably connected to the elongated arm; an engine enclosure having a distal end and a proximal end, the engine enclosure coupled to the elongated arm; and a saw attachment member connected to the saw assembly between saw blade and the proximal end of the engine enclosure; the saw attachment member connected to a support structure at a first connection point.

The present invention relates to an unmanned aerial tree harvesting system comprising a remotely and/or autonomously controlled UAV, an autonomously and/or remotely controlled tree harvesting tool configured for holding and/or delimbing and/or cutting at least a portion of a tree trunk attached underneath the UAV via at least one cord, a means configured for detecting rotational motion and/or pendulum motion of the tree harvesting tool, means attached to the UAV configured for detecting trees from above, at least one remotely and/or autonomously controlled forcing means, attached to the tree harvesting tool, configured for at least damping detected pendulum motion of the tree harvesting tool.