Abstract: An axle beam asembly (33) for an articulated vehicle (10). The beam assembly receives a drive axle (42) of the vehicle and is mounted on a frame (28) of the vehicle for rotation about a horizontal axis (30) which is laterally offset from the longitudinal centerline (37) of the vehicle. The vehicle includes a transfer case (63) having a driveshaft (48) extending therefrom to the drive axle through a hole (46) formed in the beam assembly on an axis substantially coincident with the longitudinal centerline of the vehicle.

Abstract: A regenerative hydraulic system includes a control circuit having a pressure sensing valve therein. The valve is in fluid communication with a pump and a work cylinder causing the cylinder to be actuated at a relatively high velocity during a first increment of displacement by employing regenerative techniques which interconnect the head and rod sides of the cylinder. Pressure increases due to encountering a load are monitored, and at a predetermined value, the system switches to a non-regenerative mode in which the effective force exerted by the cylinder is substantially increased. Upon switching to the non-regenerative mode, the system is latched and will remain so until the system fluid pressure drops to a second predetermined value which is substantially smaller than the first pressure, resulting in a hysteretic control characteristic which will prevent an unstable condition. A dual rate spring is included within the valve urging it into the regenerative position.

Abstract: A cab intended for use as the operator's cab of a tree harvester vehicle has an access door in the leading surface of the cab. The cab door frame, and the access door, are defined by square tubes which are turned 45.degree. with respect to the plane of the door opening to define oblique interfaces between the door edge faces and the door opening faces.

Abstract: A method and apparatus for processing trees in which a clamp holding a severed tree for processing pulls the tree through a set of delimbing blades, while at the same time the blades are moved in the opposite direction along the tree trunk. A system of pulleys and cables driven by a single hydraulic cylinder moves a movable boom and a processing head in one direction relative to a stationary boom, while a clamp assembly is moved in the opposite direction relative to the stationary boom.

Abstract: An improved tree harvesting device of the swing boom type has an energy conserving drive mechanism for driving the swing boom. The energy conserving mechanism uses an energy storing means located between a prime mover and the swing boom; the energy storing means stores the energy dissipated by the swing boom when stopping.

Abstract: A bogie drive and suspension system for a rough terrain vehicle. Suspension is by a pair of walking beams, each of which is supported by trunnions which are integral and coaxial angle drive transfer units at the ends of the walking beam transfer power to wheel end reduction units. The transfer units are of modular construction including pre-assembled and pre-aligned right angle bevel gear sets. Flexible gear type couplings, connecting the central transfer unit with the wheel end transfer units, permit deflection of the walking beams under load without affecting gear alignment.

Abstract: A processor clamp for a tree harvester. The tree engaging surface of a movable arm of the clamp is made up of two elements, a convex cam portion and a concave portion, to insure that all trees within the diameter range of the harvester will be clamped along a line either perpendicular to a downwardly angled, fixed tree engaging surface or tending to force the tree upward along the surface. The fixed tree engaging surface is adapted to penetrate a tree clamped thereon, but permits the tree to roll off into a bunk when the movable arm is released. The clamp assembly is easily removable from and attachable to the harvester to selectively use the harvester as a single tree machine or a multiple tree machine.

Abstract: A processor clamp for a tree harvester. A first tree engaging surface is defined by an edge of a frame member upstanding from the processing boom of the harvester. A second tree engaging surface is defined by a movable clamp arm which is located beneath the first tree engaging surface in its open position to free the first surface of obstruction tending to interfere with a tree being positioned on the processing boom. According to another aspect of the invention, the operating cylinder for the movable clamp arm is located within a cavity formed by the frame members of the clamp assembly, and is thus protected from damage.

Abstract: A delimber blade having a central region beveled at a first angle to form a cutting edge at the tree engaging surface of the blade, and having opposed end regions beveled at first and second angles to form cutting edges spaced from the tree engaging surface of the blade. According to another aspect of the invention a plurality of blades is provided, all of which are identically shaped and sharpened.

Abstract: An articulated vehicle in which one of the articulation pivots is mounted on the canopy of the vehicle. At least one of the hinge members of the pivot is in the form of a wide plate member to provide additional overhead protection for components mounted on the vehicle.

Abstract: An improved harvesting and processing apparatus for trees is provided. The harvester is of the type having a gripping means disposed adjacent its forward end and a boom along its longitudinal axis. A shear and delimber associated with the apparatus are longitudinally movable relative to the boom. The shear and delimber are initially positioned adjacent each other. During delimbing, the delimber moves rearward relative to the shear. At the end of the delimbing stroke, the shear is activated to sever a bolt. A greater pressure is then applied to the delimber blades so they grip the remaining trunk during the return stroke as the delimber moves forward. At the end of the return stroke the delimber and shear have returned to their initial positions and a delimbed portion of the remaining trunk extends forward a sufficient distance to be clamped by the gripping means.

Abstract: An improved apparatus for processing sheared trees is provided, as well as the harvesting apparatus for uses therein. The harvester is of the type having a gripping means disposed adjacent the forward end of the apparatus and a shear and delimber longitudinally movable relative to the boom. The shear and delimber are initially positioned adjacent each other and during the first rearward delimbing stroke, the delimber moves rearward relative to the shear. At the end of the delimbing stroke, the shear is activated to sever a first bolt, then a greater pressure is applied to the delimber blades so that they are able to grip the remaining trunk for the return stroke, during which the delimber moves forward relative to the shear. Thus, at the end of the return stroke the delimber and shear have returned to their initial positions and the delimbed portion of the remaining trunk extends a sufficient distance forwardly of the shear to be clamped by the gripping means.

Abstract: An improved method of processing a sheared tree is provided, utilizing an improved processing apparatus. The trunk of the tree is held, by a holding means, adjacent its butt end and the tree trunk is positioned lengthwise of the boom member of the apparatus. A first portion of the tree trunk is delimbed by moving a carriage, including a first delimbing means, along the trunk from the butt end to a first predetermined point. The carriage includes a gripping means which grips the trunk at a first gripping point intermediate the butt end and the first predetermined point. The hold on the tree trunk adjacent the butt end is released and a first bolt is bucked (severed), the first bolt being defined generally by the butt end and the first gripping point.

Abstract: An improved tree harvesting method is performed by a machine which includes a pair of booms mounted on a vehicle. A clamp assembly is mounted on a first boom for gripping a standing tree which is then severed close to the ground by a shear assembly which is also mounted on the first boom. The severed tree is positioned relative to a delimbing mechanism mounted on the second boom by moving the clamp assembly to place the tree in a generally horizontal position. The tree and clamp assembly are then pivoted about a longitudinal axis of the first boom to position the tree for engagement by the delimbing mechanism. The severed tree is delimbed by extending the second boom to move the delimbing mechanism along the trunk of the tree while the tree is gripped by the clamp assembly.