Abstract: A tree felling unit includes a stand on which a clamping device powered by a hydraulic cylinder is pivotally mounted such that the tree to be felled can be clamped against the stand. Also, pivotally mounted on the stand for engaging the tree at about the same level are a chain saw powered by a hydraulic motor and a shearing knife powered by a hydraulic cylinder. The shearing knife performs its shearing movement in the direction against the feed direction of the chain saw.

Abstract: According to the invention, a tree-felling unit is suspended on a crane boom by a device comprising a rotor pivotally suspended on the boom and carrying the felling unit by way of a link member.

Abstract: A feeding device for use with tree processing machines such as delimbing, barking and slashing machines wherein feed rolls are provided on each side of a feed path for the tree trunk. The feed rolls have a conical configuration and are mounted for rotation about axes inclined to each other at an angle equal to the base angle of the rolls. The surfaces of the feed rolls facing towards each other lie parallel and have a greater radial distance to the axis of rotation at the base portion of the feed rolls than at the upper portion thereof. This arrangement establishes a greater feeding force at the upper portion of the feed rolls than at the base portion and a circumferential speed for the feed rolls which is highest at the base portion and lowest at the upper portion thereby enabling tree trunks having relatively smaller diameters to be advanced through the rolls at relatively higher speeds.