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.