Abstract: A head for harvesting and processing a tree is disclosed with drive rollers which can be pivoted away from the grapple arms to enable the head to select a tree from a group of felled trees for processing when the rollers are pivoted back into place.

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 curved 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. In an alternate embodiment, the plateaus are provided at the corners of a tooth having a spherically concave attack face so as to inhibit wear of the corners.

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 curved 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.

Abstract: A saw blade disc for a tree felling head has tooth holders about its periphery which support cutting teeth asymmetrically above an inner plate of the disc.

Abstract: An articulated two-boom support for a disc saw felling head. A first of the booms is pivotally connected to a base of a logging vehicle. The second boom is pivotally connected to the first boom at a pivotal joint and the booms are further joined to each other by a knuckle joint located below the pivotal joint connecting the booms. The knuckle joint includes two links pivotally connected to each other. The link connected to the first boom is also connected to the base by a locking hydraulic cylinder. An actuating hydraulic cylinder is linked to the first boom and base so as to rotate the first boom about the axis of its pivotal connection to the base. The arrangement is such that the disc saw felling head, mounted at the free end of the second boom, moves in a direction suitable for cutting a tree as the actuating cylinder is extended. The height of the disc felling head may be adjusted by altering the extended length of the locking hydraulic cylinder.

Abstract: The invention relates to an apparatus for rotating a suspended material handling unit comprising an elongated housing to suspend the upper end of the housing from a pivotable support, and a rotor member, having a material handling unit mounted thereto. A bearing is mounted externally of the housing between the ends of the housing so as to rotationally support the rotor member relative to the housing. A fluid operated rotary motor is mounted inside the housing and has a vertical drive shaft depending from the bottom of the housing. Drive members are operatively connected to the vertical drive shaft for rotating the rotor member and the material handling unit relative to the housing. A hydraulic swivel sleeve is mounted on the external surface of the housing unit below the bearing for rotation relative to the housing. A fluid operated motor for actuating the materials handling unit is provided as are fluid conducting members interconnecting this motor, the swivel sleeve and a source of operating fluid.

Abstract: A snubbing device for a suspended grapple or the like operable by pressurized fluid in a cavity between a pin and housing of a universal joint which actuates a ramp to cause a retarding reaction between the pin and housing to prevent free swinging of the grapple.

Abstract: A snubbing device for a suspended grapple or the like operable by pressurized fluid in a cavity between a pin and housing of a universal joint which actuates a ramp to cause a retarding reaction between the pin and housing to prevent free swinging of the grapple.

Abstract: A hydraulic system (10) for a log grapple device (12), including an unloader valve (20) and an accumulator (22) located downstream of a control valve (18) which determines the direction of fluid flow to the actuating cylinder (108) controlling the opening and closing of the grapple device. When a predetermined operating pressure is reached the unloader valve diverts outlet flow from a pump (16) to a reservoir (14) and isolates the system downstream of the unloader valve, the accumulator maintaining pressure on the grapple device. When the grapple device is to be opened, a pilot check valve assembly (60) within the unloader valve permits reverse flow through the unloader valve.