Patent ID: 6189585
Filing Date: 2001-02-20
Classification: A01G,B27B

Abstract:
A single-grip harvester head for felling and processing of trees (4), which comprises a frame, which is adapted to be mounted on a forestry machine and which defines a tree feeding path (3), two feeding roller arms (5) arranged on opposite sides of said path, each arm being pivotable in relation to the frame about a corresponding pivot axis (A1) defined by a respective pivot pin (6), and two feeding rollers (7), each supported by a respective one of said feeding roller arms (5) and rotatable about a corresponding rotation axis (A2) parallel to the pivot axis of the respective arm, the feeding rollers (7) being movable, by the pivoting of the feeding roller arms (5), towards or away from the tree feeding path (3) in order to be able to grip and feed trees (4) with various stem diameters along said path, characterised in that:each feeding roller arm (5) is formed as an angular lever having two lever legs (5a, 5b), the feeding roller (7) being supported at an end of one of the legs (5a) and the pivot pin (6) of the feeding roller arm (5) being positioned in the angular area joining the legs;the two pivot axes (A1) are located in a common plane perpendicular to the tree feeding path (3);the pivot pin (6) of each feeding roller arm (5) at one of its ends is articulated to the frame by a respective joint (13) about an axis perpendicular to said plane and at its other end is controlled by a respective control device (14) fixedly connected to the frame in such a way that the corresponding pivot axis (A1) is movable in said plane but fixed in a direction perpendicular to said plane; andthe other leg (5b) of each feeding roller arm (5) is articulated to a slide (17) by a respective universal joint (16), which slide is reciprocatable along the tree feeding path (3) in relation to the frame to maintain a constant distance between the universal joints (16) during the pivoting of the feeding roller arms (5).