Abstract: An accumulator arm for a felling head has inner and outer arms which are hydraulically driven open and closed. The inner and outer sides of the outer arm are curved away from an accumulation pocket and toward a harvesting arm, wherein the accumulator arm can be pulled around a newly cut tree to add the tree to the accumulation pocket with a lesser amount of hydraulic force and with lesser damage to the trees.

Abstract: A tree felling machine has a main pump for operating functions of the machine such as the drive wheels or tracks, the steering, the brakes, and the lifting and extension of the boom, and a separate saw pump for driving the cutting element, for example, a circular disc saw driven by a hydraulic motor. Both pumps are driven by the same prime mover, i.e. the same internal combustion engine, and the power division between the two pumps is determined by the operator and by the hydraulic control system. In particular, a control provided in the cab is controllable by the human operator to limit the maximum power that the saw pump can draw from the prime mover. In addition, the power that the saw pump can draw from the prime mover is limited by a combination of the displacement setting of the main pump, the output pressure of the saw pump, and the pressure exerted on the load by the main pump.

Abstract: A steering system for an articulated vehicle has a microprocessor connected to a proportional solenoid valve which controls the direction, amount and rate of flow of hydraulic fluid to and from hydraulic articulation cylinders, which provide articulation between the frames of the articulated vehicle. A positional feedback sensor measures the angle of articulation between the frames and communicates the angle of articulation to the processor. A gear sensor monitors the gear that the vehicle is in and communicates it to the processor. A user input device allows a user to select the desired level of steering sensitivity and also allows the user to input the size of the tires installed on the vehicle. A steering device allows the operator to provide steering input and communicates electrical steering signals to the processor based on the steering input from the operator.

Abstract: A hydraulic system has gravitional load energy recuperation by opening a recuperation piloted valve with a pilot pressure supplied by a hydraulic pump so as to drive a recuperation hydraulic motor with a source of fluid pressurized by gravity from the load. The recuperation hydraulic motor drives the mechanical drive train of the prime mover that drives the pump that supplies the load, and other pumps that supply other loads.

Abstract: A butt plate for a felling head includes a ramped portion in an accumulation pocket. The ramped portion is sloped downward generally toward a line extending in the direction of forward travel of the head. The butt plate allows for high accumulation of trees while retaining stable bunches.

Abstract: An accumulator arm for a felling head has inner and outer arms which are hydraulically driven open and closed. The inner and outer sides of the outer arm are curved away from an accumulation pocket and toward a harvesting arm, wherein the accumulator arm can be pulled around a newly cut tree to add the tree to the accumulation pocket with a lesser amount of hydraulic force and with lesser damage to the trees.

Abstract: A hydraulic control system has a pilot pressure supply circuit that applies a pressure differential dependent on engine speed to opposite sides of an anti-stall valve to turn off the pilot flow when the pressure differential falls below a certain value, resulting in holding the positions of the hydraulic devices being controlled until engine speed recovers.

Abstract: An apparatus and method for harvesting trees and reducing their stumps is disclosed. The apparatus includes a rotating member including an upper disc saw blade and a lower stump grinding drum blade. The disc saw blade severs the tree from its stump, and thereafter the drum blade reduces the height of the stump down to at or near ground level.

Abstract: A disc saw felling head has a replaceable lower blade housing and an optional replaceable wear liner in the housing.

Abstract: A saw blade for a tree felling head has three tipped teeth in which only one tip of each tooth is exposed outside of the blade disc. Around the circumference of the blade, teeth with tips exposed on the upper side of the blade alternate with teeth having tips exposed on the lower side of the blade. Axes of the teeth are tangent to radii of the disc and angled upwardly or downwardly relative to the plane of the disc, and mating surfaces on the teeth and disc at 45° to the plane of the disc abut against rotation and loading of the teeth.

Abstract: A tree felling saw head has two pairs of links and two hydraulic actuators to provide high rotation of the head relative to a mounting adapter in a lateral plane which is perpendicular to a cutting plane.

Abstract: A clamp control system for a feller/buncher has three buttons for automating the operation of the harvesting and accumulating clamps. A CLOSE button, when momentarily actuated for the first tree of a bundle, closes the harvesting clamp and the accumulating clamp and then re-opens the harvesting clamp. When actuated again momentarily for the second and subsequent trees, the harvesting clamp closes, the accumulating clamp opens and re-closes and the harvesting clamp re-opens. Actuation of an OPEN button opens both clamps and resets the system to be ready for the first tree of the next bundle. Actuation of a STOP/CANCEL button freezes both clamps in their current positions.

Abstract: A hydraulic boom control system has two valves controlling linear hydraulic actuators, one for pivoting a hoist boom relative to a machine and one for pivoting a stick boom relative to the hoist boom. The bore sides of the actuators are hydraulically connected and the rod side of the hoist actuator is connected to the first port of the first valve and to the second port of the second valve. Operating the first valve moves the boom end generally horizontally and operating the second valve moves it generally vertically.

Abstract: A bar saw felling head clamps a tree between harvesting and reaction arms during cutting and after the cut sweeps the tree rearwardly with the harvesting arm into an accumulation pocket where an accumulating arm holds it and any already cut trees. The bar saw cuts from a cocked position normal to the machine direction to a home position which is perpendicular to the cocked position, where the bar saw is housed in a protective box.

Abstract: A disc saw felling head has the cutting pocket positioned relative to the tooth entry opening into the housing such that chips being thrown out of the kerf by the teeth are thrown radially outwardly of the entry opening. The chips are thrown against a deflector plate which redirects them back toward the center but away from the disc to dissipate energy in the chips, reduce the directions in which chips are thrown, and reduce clogging of the housing.

Abstract: A swing-to-tree feller buncher has its boom swing-house assembly adjustably supported from its track carriage frame by a leveling mechanism which includes a front link, a rear link, and a pair of laterally spaced apart hydraulic cylinders. Both links are fixed to the frame toward the front of the carriage and the front link is shorter than the rear link. The upper ends of the hydraulic cylinders connect to the turntable support of the swing-house assembly at a position forward of the rear link and extend rearwardly to connect at their lower ends to the frame of the carriage at a position which is rearward of the rear link. The turntable support is also pivotable from side to side relative to the carriage about a minor axis.

Abstract: A disc saw felling head has the cutting pocket positioned relative to the tooth entry opening into the housing such that chips being thrown out of the kerf by the teeth are thrown radially outwardly of the entry opening. The chips are thrown against a deflector plate which redirects them back toward the center but away from the disc to dissipate energy in the chips, reduce the directions in which chips are thrown, and reduce clogging of the housing.

Abstract: A disc saw felling head has a window in a sidewall of the head through which chips are discharged in a tangent plane and a discharge chute over the window. The chute has a top wall and inner and outer sidewalls shaped so that chips exiting the head through the window are directed along a chip path which is generally parallel to the tangent plane and first turns further rearward and then turns outward through a lateral discharge opening in the chute.

Abstract: A square saw tooth having four cutting edges of the type which is rotatable about its axis on a saw disc to present a fresh cutting edge when the radially outermost edge wears out has carbide wear plates covering the high wear areas of its attack face and providing its cutting edges. A wear plate is provided at each corner of the attack face, and each wear plate has a flat rear surface for attachment to the tooth body and a front surface of a complex shape, having plateau surface areas at the corners, where the plates are thicker, and one or more cylindrically curved concave surfaces which recede from the plateau areas toward the interior of the attack face, so that the plate recedes in thickness away from the plateau area. This construction helps provide more uniform wear over the surfaces and edges of the attack face for a more efficient consumption of the wear plates.