Abstract: The present disclosure relates to a tree harvesting machine (120) having a crane arm (118), wherein the crane arm (118) comprises a tree harvesting head (100; 200) arranged at a free end of the crane arm (118). The tree harvesting head (100) comprises a saw (104) and at least two feed wheels (102). The tree harvesting head (100) further comprises an electric motor (106a) arranged to drive the saw (104), and at least one electric motor (106b) arranged to drive the feed wheels (102). The present disclosure also relates to associated tree harvesting monitoring systems, tree harvesting heads, methods and computer programs.

Abstract: Method and device for delimbing a tree trunk (60) in a compliant gripping state defined by a set of limbing knives (18, 24, 26, 28) enclosing the trunk. The limbing knives are repeatedly adjusted through a control unit (46) for adaption of the gripping state to a varying thickness of the trunk when the trunk is advanced between the knives for the delimbing of the trunk. The invention comprises entering a desired compliance (D1) of the gripping state in the control unit (46), detecting an actual compliance (d) of the gripping state, and performing each adjustment of the limbing knives via the control unit until the actual compliance (d) corresponds to the desired compliance (D1).

Abstract: Method and device for the determination of a thickness of a cross-section (S) of a tree trunk (30) received in a harvesting assembly (10) comprising a pair of opposite feed wheels (14) engaging with the tree trunk and a delimbing knife (18) abutting against the tree trunk. The mutual position of the feed wheels is detected as a measure of a transverse dimension (D1) of the cross-section of the tree trunk. The position of the delimbing knife (18) in relation to an abutment surface (22) of the tree trunk opposite thereto is detected as a measure of an additional transverse dimension (D2) of the cross-section (S) of the tree trunk, which additional transverse dimension forms an essentially right angle with the first-mentioned transverse dimension. The thickness of the cross-section (S) of the tree trunk is calculated based on the two measures of the transverse dimensions (D1, D2).

Abstract: A saw box for preventing chain shot from a broken sawchain of a chainsaw, the saw box including a stationary shield that covers a rear section of the saw. The shield has an end surface that extends between an outer surface and an inner surface of the shield and has such hardness and is designed with a convex curvature of such a radius that one part of the broken sawchain that comes to an external location during operation of the saw can slide around the end surface in an essentially unhindered manner in a direction towards the inner surface.

Abstract: A feed wheel (10) for tree trunks, with rows of drive teeth (30) protruding from extended supports (20) united with a peripheral surface (18) of the wheel. In order to make the spaces between the supports (20) more self-clearing, supports (20) that are neighbours extend mutually divergently throughout the complete sideways direction of the peripheral surface (18) (at an angle ?).