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 timber working device, comprising a frame, having a feed axis, a drive system, configured to feed at least one stem along the feed axis, at least a pair of upper knives or lower knives movably attached to the frame, wherein the knives are configured to be controllable each by an actuator to open and close around a stem, a tilt mechanism comprising a controllable tilt bracket pivotably attached to the frame, to control a tilt position of the frame in relation to the tilt bracket.

A forestry harvester for delimbing a tree with an angular upper cutter and side cutters while advancing the tree by feed rollers, wherein when the feeding of the tree is stopped due to being incapable of cutting the limbs off, the angle-shaped upper cutter and the side cutters are moved relative to the tree with rotation of the feed rollers stopped to cut off the limbs of the tree therewith. The forestry harvester comprises a feed unit (1 or 100) including a pair of left-hand and right-hand clamp arms (8, 9 or 108, 109) and feed means (20 or 120), a chain saw box (22a) having a power chain saw (22), a delimbing unit (2) including an angle-shaped upper cutter (52) and a pair of cutter arms (26, 26) each having a side cutter (25), guide mechanism for guiding the delimbing unit for forward and rearward movement of the delimbing unit relative to the feed unit, and a hydraulic cylinder (47) actuated to move the delimbing unit (2) toward and away from the feed unit (1 or 100).

An adaptive lighting system for a work vehicle controlled by an operator from an operator station and having a work tool and a method for illuminating a work area are provided. The system includes at least one lighting member configured to illuminate at least one portion of a work area, an actuator coupled to the at least one lighting member and configured to position the at least one lighting member relative to the operator station, and a controller in communication with the actuator and configured to control positioning of the at least one lighting member via the actuator based on an operator control position and a position of the work tool.

An adaptive lighting system for a work vehicle controlled by an operator from an operator station and having a work tool and a method for illuminating a work area are provided. The system includes at least one lighting member configured to illuminate at least one portion of a work area, an actuator coupled to the at least one lighting member and configured to position the at least one lighting member relative to the operator station, and a controller in communication with the actuator and configured to control positioning of the at least one lighting member via the actuator based on an operator control position and a position of the work tool.

A log processing head with a top knife and moveable feed means and delimbing and/or debarking means pushing a log against the top knife by means of actuators. In order to allow the top knife to follow the contour of the log without damaging a pin holding the knife, a pivot joint is used between the knife and the connection of the pin on the structure.

A log processing head with a top knife and moveable feed means and delimbing and/or debarking means pushing a log against the top knife by means of actuators. In order to allow the top knife to follow the contour of the log without damaging a pin holding the knife, a pivot joint is used between the knife and the connection of the pin on the structure.

A hydraulic drive for feed rollers of a head of a complete timber harvester includes two radial piston motors coupled for conjoint rotation to the feed rollers. One radial piston motor has only one displacement volume and the other radial piston motor has two displacement volumes, between which it is possible to switch. A tree trunk clamped between the feed rollers can thus be moved at two speeds. At the higher speed, pressure medium circulates under a control pressure in the second displacement volume of the switchable radial piston motor.