Abstract: The mechanism is used for rotating a tree-felling implement rotatably connected to a distal end of a boom of a logging vehicle by an implement pivot. The mechanism comprises a pinion coaxial with the implement pivot and fixed in rotation with reference to the distal end of the boom. Two longitudinally extending actuators are mounted on the frame. Both actuators are lying in the pinion plane. Each actuator is adjacent to the pinion on a respective side thereof, namely right and left, and bears a corresponding sprocket coplanar with the pinion plane and rotatably connected to their free end. To link the elements together, there is provided a chain in mesh with the sprockets and the pinion. The chain has ends rigidly attached to the frame of the implement. In use, the implement is rotated as the actuators are operated in opposite directions.

Abstract: The mechanism is used for rotating a tree-felling implement rotatably connected to a distal end of a boom of a logging vehicle by an implement pivot. The mechanism comprises a first arc-shaped member that extends in a plane perpendicular to the boom plane and is convex with reference to the implement pivot. The first member has a first end rotatably connected to the frame of the implement at a given distance from the implement pivot. A second arc-shaped member, coplanar with the first member, is also convex with reference to the implement pivot. The second member has a first end rotatably connected to the second end of the first member for defining an intermediary junction, and a second end rotatably connected to the distal end of the boom. A hydraulic actuator is mounted on the frame of the implement and has an end rotatably connected to or adjacent to the intermediary junction for rotating the implement during operation of the actuator.

Abstract: The mechanism is used for rotating a tree-felling implement rotatably mounted with a pivot to the distal end of the boom of a logging vehicle. The mechanism, the tree-felling implement, the boom and the logging vehicle form a tree-felling machine controlled by an operator and used on logging sites. The mechanism has a pinion coaxial with the implement pivot and fixed in rotation with reference to the distal end of the boom. An arc-shaped rack is rotatably mounted on the frame of the implement by a rack pivot in spaced relationship with the pinion. The rack is in mesh with the pinion and hydraulic actuators are provided on the frame of the implement for swaying the rack and thereby rotating the implement with reference to the boom. Such mechanism is capable of rotating the tree-felling implement with reference to the boom plane in both directions and according to a much wider range angle than the prior art mechanisms.