Abstract: The operating pressure for the hydraulic drive means (15; 26) is generated in the chassis (2) of the vehicle (1). A revolving structure (3) is arranged on the chassis, said revolving structure carrying the driver's cabin (7), a boom (5) with a tools (6) and a hydraulic motor for rotation of the revolving structure (3) relative to the chassis. The revolving structure is connected to the chassis by a live ring (16;23) that is driven by said hydraulic motor and has a hydraulic fluid duct (12;24) between the chassis and the revolving structure. The chassis is provided with an eccentric plate (11) carrying on its top side the above-mentioned live ring for the revolving structure while the bottom side of said eccentric plate has an eccentrically supported displacement bearing (13). Said displacement bearing is secured by a latching device (25) on the bottom side of the eccentric plate (11) during normal operation of the vehicle or digger (1).

Abstract: A tree felling and shaping apparatus is provided with a fully powered and controllable link system which links a tree processor head to a boom that is in turn mounted to a vehicle. The link system includes two powered pivoting joints and a rotary coupling of up to 360° disposed therebetween. Such a combination provides a great convenience for the manipulation of the tree felling and shaping apparatus, not only permitting a maximum angular adjustment of the tree processor head for all directional orientations whether the head is in an upright position for felling trees or the head is in a recumbent position for processing trees, but also performing a universal joint function to freely suspend the tree processor head from the boom without using a conventional uncontrollable universal joint. The present invention improves maneuverability of the tree felling and shaping machines and thereby increases work efficiency.