GB1423546A - Tree harvester - Google Patents

Abstract

1423546 Felling trees L & L LOGGING RESEARCH Ltd 29 May 1973 [5 June 1972] 25492/73 Heading A1E [Also in Division B8] A light-weight mobile tree harvester with tracks 11, 12 capable of travelling over soft ground and snow has shearing jaws 33, gripping arms 34, 35 and delimbing blades 40-42 mounted on a head 28 which is pivoted to a boom 21. The boom is reciprocatable in a cage 22 which can be pivoted by rams 25 about a horizontal pivot 14. The cage is mounted on a platform 16 which pivots in a horizontal plane about a bearing 13. In use the boom is extended and the head 28 is aligned with the base of a tree trunk and hydraulic cylinders 46, 48 operated to cause arms 34, 35 to grip the tree. The jaws 33 are then actuated by hydraulic rams 79 to sever the trunk. Then, while the tree continues to be held, the boom is pivoted upwardly by the rams 25 and retracted. The platform is then pivoted to bring the head out of the path of the vehicle, the boom lowered to a horizontal position, and the head pivoted to a horizontal position, thus bringing the tree to a horizontal position. The shear jaws are then opened, and rollers 37, 38, which are mounted in the gripper arms, are driven by hydraulic motors to shift the tree trunk axially until the cut end abuts a plate 39 on the platform. During this movement the blades 40-42 remove the branches from the first section of the trunk, and this section is then severed by the jaws 33. The delimbing process is then repeated for the subsequent sections.