Abstract:
In the positioning system for an operating cylinder (1), a valve or a set of valves (6; 10, 11) comprises means for allowing a free supply of hydraulic fluid from a pump fluid chamber (8) of a pump cylinder (7) into an operating fluid chamber (2) of the operating cylinder (1), for preventing the backflow of hydraulic fluid from the operating fluid chamber (2) into the pump fluid chamber (8) when the hydraulic fluid pressure on the control side (A) rises above a predetermined pressure limit, and for allowing a free back flow of hydraulic fluid from the operating fluid chamber (2) into the pump fluid chamber (8) when the hydraulic fluid pressure on the control side (A) goes below the predetermined pressure limit. An operating piston rod (3) follows closely the movement of a pump piston rod (9), and the valve or the set of valves (6; 10, 11) prevents pressure fluctuations from transmitting from the operating side (B) to the control side (A). The system can be used for instance in a hole-rotor-type barking machine (16) for positioning the operating cylinders of barking blades (17). The system can also be used for positioning the operating cylinders (1) operating the gripping jaws (19) of a hydraulic gripper (18) of a machine. Furthermore, the system can preferably be used for positioning the operating cylinders of pusher shafts, lift booms and articulated knuckle booms of a machine.
Abstract:
A pruning assembly (10) including an elongate supporting body (not shown), right (11) and left (12) jaw members hinged together and movable along the supporting body and each having three sets of blade members (31) mounted on actuator means (16) and alternatively displaced above and below a plane to form two staggered rows of three bores each, the actuator means (16) adapted to maintain the clearance between the trunk and each set of blade members (31).
Abstract:
A method for optimizing the debarking result of logs debarked in a debarking drum, especially logs of mutually approximately the same size and of the same wood species, in such a way that wood losses remain as small as possible at the same time as the control values of the debarking drum are selected to be such that the debarking degree of the logs debarked in the debarking drum is of the desired order. The amount of bark remaining on the logs in the log flow discharged from the debarking drum and the amount of damaged logs in the said log flow are measured. At the same time as the amount of bark remaining on the logs is maintained at a desired level, the amount of damaged logs is kept as low as possible in such a way that the filling degree of the debarking drum is lowered whenever the amount of damaged logs is observed to increase.
Abstract:
A process and apparatus for manufacturing wood chips as raw material in the production of mechanical pulp in order to reduce energy consumption. The process includes irreversibly deforming a plurality of fibers of at least one piece of wood in a direction perpendicular to the longitudinal axis of the fibers. The wood fibers include summerwood fibers. The irreversible deformation is accomplished through mechanical treatment. The apparatus used includes one or several tools arranged so that the forces created during the process act in a direction substantially perpendicular to the longitudinal axis of the fibers so as to irreversibly deform the fibers across the grain.
Abstract:
This invention relates to a wood chip recovery system which removes bark from roundwood or wood chips. It is desirable for such structures of this type to recover the wood chips from the bark without introducing contaminants, such as metal ions like iron, into the debarked roundwood or wood chips.
Abstract:
This invention relates to debarking and chipping folded whole trees. Such structures of this type, generally, increase wood recovery by making high-quality chips out of tree tops, branches, as well as, other larger portions of the tree.
Abstract:
A timber harvester includes a scissors-like frame component including opposing segments with a common joint, a fork-shaped tilting device, a saw device installed at the rear end of the harvester, opposing tree feed devices installed on both of the aforementioned segments, articulated lower delimbing blades driven by an operating device, and at least one upper delimbing blade supported by at least one segment. The upper delimbing blade is secured, with the aid of the first and second sliding members from both segments so that the first sliding members include, in both segments, a linear guide that lies generally in the direction of the segment itself, and slides adapted to the linear guide in the upper delimbing blade. The second sliding members including at least one joint in the upper delimbing blade of the nearest slide, and at least one curved guide in one segment, the second sliding members being arranged to prevent the twisting of the upper delimbing blade.
Abstract:
An apparatus and method for machining the surface of logs, in which the log is longitudinally advanced through an opening provided in a rotor disc and the surface of the log is machined by rotatable cutting heads mounted on respective supporting arms pivotably connected to the rotatable disc and rotating therewith around the logs. The cutting heads are rotated around respective axes of rotation, while concurrently the cutting heads rotate with the rotor disc around the log such that the net rotational speed of the cutting heads at the surface of the log is the sum of the speed of rotation produced by the rotatable disc and the speed of rotation of the cutting heads around their respective axes. In the course of machining the logs, the speed of rotation of the rotor disc is varied as a function of conditions at the surface of the log and the rotational speed of the cutting heads around their axes is varied in relation to the rotational speed of the rotor disc to maintain a substantially constant net rotational speed of the cutting heads at the surface of the log.
Abstract:
A tree delimbing device having a self-aligning cutter head for delimbing a tree stem which is mounted on a frame by a rotational and pivotal support. A substantially inelastic flexible member connects the cutter head to the frame to limit movement of the cutter head. A medial portion of the flexible member is connected to a fluid cylinder so as to urge the cutter head toward a centered position. An accumulator may be provided for regulating the pressure of the fluid in the cylinder. The positioning of the fluid cylinder may be adjustable. A tree stem diameter measuring device having a sliding position indicator may also be provided. A tree stem detector may also be included to sense the presence of a tree stem placed within the cutter head for automatically closing and opening the blades around the stem. A removable mount for the cutter head is also included.
Abstract:
A waste debarker 10 comprises a housing 12 in which is mounted a rotatable first cutting drum 14 and a rotatable second cutting drum 16 arranged in a longitudinally spaced relationship with respect to the first drum 14. The first drum 14 has a plurality of circumferentially extending flanges 24 spaced along the length thereof for supporting cutting teeth 26 thereon. The second drum 16 has a plurality of discrete lugs 34 arranged on its surface for supporting cutting teeth 26 thereon. The lugs 34 are offset with respect to the flanges 24 on the first drum 14 and extend in between the flanges 24 as the drums 14,16 are rotated. The second drum 16 is located at a higher elevation than the first drum 14. A method of debarking waste material is also provided.