Abstract: A method and apparatus for aiming a tree to be felled including a tool for precisely marking a face notch to be cut into a tree trunk, said tool comprising a main body, an aiming rod on the main body, and two pivoting tree-engaging marking arms mounted pivotably together on the main body for partially encircling the tree trunk and identifying the upper and lower cuts of a generally horizontal portion of a hinging notch when the aiming rod is aimed in the direction of fall. The tool includes angular adjustments to allow marking an aiming notch which compensates for the lean of a tree and/or for trees with trunks of irregular cross section.

Abstract: A ring saw is described which has a novel construction for centering the cutting ring. The ring saw is characterized by a groove in the inner annular surface of the cutting ring. A plurality of rollers are provided which engage the groove in the inner annular surface. The rollers serve to center the cutting ring relative to the saw body while withstanding axial and radial loads placed upon the cutting ring. The construction, as described, serves to increase the capacity of the cutting ring to withstand radial and axial loading.

Abstract: A high reach self centering hydraulic tree trimmer which consists of first a carriage assembly. The carriage assembly consisting of a top plate and a bottom plate. The plates are separated by spacers and secured together with a plurality of fasteners. A pair of cutting blades are contained between the top plate and the bottom plate. The blades are reciprocal of each other and each have a front end, center region, back end, outer edge, inner edge and a cutting edge extending along the inside edge. The blades are self centering about an object to be cut by pivoting independently from each other They pivot about separate pivot points in the center region of the blades. A pivot pin or bolt is used as a pivot device extending from the top plate to the bottom plate. A hydraulic cylinder is used to operate the blades. The hydraulic cylinder is pivotally attached to the back ends of the blades.

Abstract: A housing is arranged to include a plurality of rows of projecting cutting wheels for projection into a bush to be cut, with the housing further including cutter knives mounted between adjacent coplanar pairs of the cutting wheels to effect the comminuting of brush and the like directed within the housing.

Abstract: A cutting tooth holder for circular saws used on felling heads. A plurality of the holders are mounted on a circular saw disk about its rim. Each holder has a clevis shape with the leg of the holder that is on top of the saw disk being relatively short compared to the length of the leg on the bottom of the saw. The short upper legs of the holders permit the use of a larger butt plate on the felling head to cover the saw.

Abstract: A cutting and/or sawing unit for timber handling purposes and adapted to be mounted on the free end of a working arm or jib of an off-road vehicle. The unit includes a saw (4) rotatably mounted on a motor stand (1) and knives (6) which project out from a hub part (5) of the saw. The knives are intended to coact with a toothed device (7) on the motor stand (1), to obtain a cutting action in addition to a sawing action. Mounted on the upper side or top plate (11) of the motor stand is a gripping device (2). The motor stand (1) is pivotally suspended on a preferably horizontal shaft (13) journalled in a suspension link (14). This arrangement enables the saw (4) or the griping device (2) to be brought to a working position relative to the surface of the ground, by rotating the motor stand (1).

Abstract: A grapple saw is provided with positive pressure grapple arms to securely hold trees during felling. The grapple saw has a frame for receiving a tree to be felled. A grapple arm mounted on the frame pivots to hold the tree against the frame as it is severed by a saw. Positive pressure is provided to the clamping arm during the severing operation to prevent movement of the tree.

Abstract: A cutting tooth for a tree felling saw having a concave front surface and a convex rear surface can be removably fixed to a saw by a fastening device The front surface and the rear surface are uniformly spaced and have a plurality of side surfaces extending therebetween. The intersection of each side section with the front surface forms a cutting edge. An aperture is formed in the cutting tooth for receiving the mounting element.

Abstract: The invention relates to a method and a device for cutting off the trunk of a tree by detonation of an explosive charge in contact with the trunk. The invention solves the problem of providing a safe and convenient way of cutting off the trunk of a tree which has fallen to an inclined position where it rests against another tree or against an electric overhead line. To the trunk there is, at the desired level above ground, attached a holder which carries an explosive charge and can from the ground be mounted on the trunk, whereupon the charge is detonated and the trunk section above the cut-off level severed from the section below. In this way the top section is either directly released from its support or can conveniently be so released.

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: A timber harvester disclosed includes a frame (1), two feed tracks (5) jointed opposite one another, a front stripping blade (20), and a rear stripping blade (16). A frame (4) of the feed track (5) is carried on jointed trapezoid arms (2,3). A rear stripping blade (16) is located on the frame (4) of one of the feed tracks (5) and is jointed essentially on the line of the compressive force between the feed track (5) and a tree (7), when seen from the direction of the timber feed.

Abstract: An apparatus for providing a warning of the rotation of a spindle for a machine such as a wood working machine which gives a warning while a spindle continues to rotate due to inertia even after a motor driver for a spindle motor for rotating the spindle is interrupted thus enhancing the safety of operation of the machine. The apparatus comprises a warning device for warning that the spindle is rotating, a rotation detecting device for detecting rotation of the spindle and continuously generating, while the spindle is rotating, an electric signal independently of whether the motor driver is operative or inoperative, and a controller for discriminating between the presence and absence of an electric signal from the rotation detecting device and controlling the warning device in accordance with a result of the discrimination.

Abstract: A tree cutting apparatus includes a frame having forward and rearward ends, with single generally planar blade rotatably mounted on the forward end of the frame. The blade has a cutting edge extending around a portion of the periphery thereof. The cutting edge as a forward and rearward end, with the cutting edge being spaced a distance from the rotational axis of the blade increasing from the forward end to the rearward end, such that the cutting edge of the blade moves transversely with respect to the forward cross-member as the blade rotates to cut a tree or the like.

Abstract: An articulated brush cutting vehicle is provided having a rear powered unit and a front steering unit. A circular blade brush cutter is mounted on the forward end of a truss boom, the truss boom being pivotally mounted to the steering unit for side-to-side swinging movement and for up-and-down movement. Concealed hydraulic cylinders within said steering unit control the side-to-side movement of the boom and articulation between the vehicle units with minimal exposure of the cylinder rods during operation of the vehicle. The boom has an inverted apex on its bottom side so that the cutter may be operated even though there may be an obstruction between the steering unit and the cutter blade.

Abstract: A feller head having a circular saw at the base thereof with a housing surrounding the circular saw, and an opening in the housing exposing the circular saw. A movable guard can be rotated between an open position within the housing and a closed position where the guard extends across the opening protecting the circular saw. The feller head also has a pair of grapple arms in the upper portion of the frame and an accumulator arm in the lower portion of the frame.

Abstract: A tree felling apparatus has a U-shaped base with a pair of laterally spaced arms defining a cutting area for receiving therein a tree to be cut and a chain saw mechanism movable through the cutting area for cutting a tree. The chain saw mechanism includes a saw bar which is tapered inwardly from its proximal end to its distal end for even distribution of bending stress across the saw bar.

Abstract: A tree harvester is rotatable about three distinct axes to increase the efficiency of cutting and stacking trees. A cut tree is rotatable about a first axis by a rotation bearing and an associated hydraulic cylinder to move the tree in a sideways direction from the vertical plane. The cut tree is also rotatable about a second axis by moving a second rotation bearing to allow the jaws to grip the selected tree even when it is surrounded by adjacent trees. The frame is rotatable about a third substantially horizontal axis so that the cut tree may be tipped forward from the vertical plane to facilitate stacking. The tree harvester also includes an improved grab jaw having greater gripping force, and an improved saw bar designed to minimize chain jumping.

Abstract: A tree harvester including gripping arms (4, 5) a cutting tool (3), and a primary tree-holding device (10) for the accumulation of harvested trees. The primary holding device includes a pivotal tree-holding member (15) having an axially extensible arm (18) and functioning to hold the accumulated trees firmly against an abutment (11) provided on the primary holding device (10). The harvester also includes a magazine (30) in which harvested trees are collected, and a secondary tree-holding device (40) by means of which the trees are retained in the magazine. The secondary holding device includes a pivotal tree-holding member (41) provided with an axially extensible arm (44) operative to hold the trees collected in the magazine (30).

Abstract: The invention concerns a forest harvester suspended pivotally at the end of a crane jib (1) and rotatable around its shaft of suspension for felling of a tree trunk and for trimming and possible cutting-off of the tree trunk in the horizontal position. The harvester comprises a suspension arm (3) shaped substantially as an inverted L and a processor unit (4) mounted pivotally at the lower end of the arm, the side of the processor unit (4) placed facing away from the suspension arm (3) being provided with a cross-cutting member (6), with two groups of trimming members (7,8) placed at a distance from one another, and with at least two drive rolls (9, 10) jointly operative with each other, with variable mutual spacing, and mounted between said groups of trimming members.

Abstract: A vehicle is provided for skidding timber. Conventional skidders are generally large tracked or rubber tired vehicles having a fixed frame to which a towing cable is attached. The cable load applied to such skidders is rearward of the rear wheels tending to reduce the load on the front wheels and increase the load on the rear wheels. A vehicle in accordance with the invention includes a frame pivotally mounted upon the vehicle's chassis. A cable sheave is mounted upon the outer end of the frame and a towing cable reeved over the sheave with a cable winch attached to the forward end of the cable. Attachment means secure logs to the end of the cable. Abutment means connected to the outer end of the frame engage the attachment means as the cable and log are drawn forwardly by the winch. When the attachment and abutment means engage further winching in of the cable rotates the frame from a rearward position to a forward position. In the rearward position, the cable sheave is rearward of the vehicle's rear wheels.

Abstract: An improved tree felling head that minimizes splintering of the butt ends of trees while felling them, and that also minimizes losing them off the felling head after they are cut. The felling head has retaining means for loosely retaining the trees cut or being cut within tree receiving cradles provided on the felling head.

Abstract: A tractor supported and driven tree cutting apparatus which causes linear movement of a rotary cutter for cutting a tree trunk from the side portions thereof. The apparatus incorporates a frame structure having a hydraulically driven slide support guided by parallel structural members of the frame. The rotary cutter is rotatably supported by the slide structure and is driven by the power take-off of the tractor which is operatively connected to a drive gear mechanism connected to the rotary cutter. The rotary cutter includes cutting teeth angularly mounted about the periphery thereof for cutting the tree trunk below ground level.

Abstract: A rotator for crane-mounted working implements comprises a housing (7) swingably connectible with the tip of the crane via a joint, and a pivot shaft (8) connectible with the working implement and pivotal relative to said housing by means of at least one vane or flap (10) operating in a chamber and dividing said chamber into two operating chambers which can be supplied with, or evacuated of, hydraulic medium via two first ducts (12) provided in said housing, said pivot shaft including second hydraulic medium through-ducts (17, 17') opening into annular hollow spaces (16, 16') in a swivel connection (15) incorporated in said housing.

Abstract: A tree saw includes a frame adapted to be attached to the boom of a prime mover, a tree clamping mechanism on the frame, and a carriage assembly on the frame below the clamping mechanism. The carriage assembly includes a generally plate-like chassis, a generally U-shaped bulkhead upstanding from the chassis and providing a recessed base portion and forwardly-extending arm portions, and a slide mechanism on the arm portions. A rail mechanism on the frame receives the slide mechanism for reciprocating movement of the carriage assembly. A hydraulic cylinder assembly interconnects the bulkhead and frame for reciprocating the carriage assembly. An annular rim member rotatably mounted on the chassis has a geared inner circumference and a toothed outer circumference projecting forwardly of the base portion. A motor-driven pinion mechanism on the chassis engages the rim member inner circumference to rotate the rim member.

Abstract: A tree felling apparatus having a U-shaped base with a pair of laterally spaced arms defining a cutting area for receiving therein a tree to be cut and having a chain saw mechanism movable through the cutting area for cutting a tree includes saw tracking device, an apparatus for adjusting the tension of the endless saw chain of the chain saw mechanism and a resilient member. The saw tracking device defines a tracking area for confined receipt of the distal end portion of the chain saw assembly during tree cutting movement thereof for limiting the deflection of the chain saw assembly which may be caused by reactive forces exerted by a tree being cut. The apparatus for adjusting the tension of the endless saw chain includes a support member mounted to the distal end of a saw bar of the chain saw mechanism and an adjusting member having an noise roller rotatably mounted thereto.

Abstract: A concaved saw blade for tree felling apparatus adapted to be rotatably actuated through its center. The blade is inclined relative to the ground and is moved forwardly in a horizontal plane towards the tree to be cut. Saw teeth are adapted to be removeably mounted on the periphery of a rotatable saw blade of the flat or concave type. The teeth per se are made of a square head and a shaft extending rearwardly. The shaft is adapted to slide in a sleeve axially welded on the periphery of the saw blade. The shaft is adapted to be mounted in the sleeve in four different positions so that the head which is square and has a concave front face can make use of each of the four cutting edges surrounding the head for cutting trees.

Abstract: A method and apparatus to fell a tree is disclosed. A vehicle mountable felling head includes a circular saw mounted to the felling head. A guard overlays the circular saw as a safety measure. The guard has a first portion which is fixed. The fixed portion of the guard has an opening exposing a first arcuate portion of the saw. The guard also has a second, movable portion which overlays a second arcuate portion of the circular saw. The second portion of the guard may be raised to expose a second arcuate portion of the circular saw to cut a slot in one side of a tree with the cut being completed by the first arcuate portion thereby allowing a tree greater in diameter than the radius of the circular saw to be severed.

Abstract: The present invention relates to a cutting head for use on a tree-felling vehicle. The cutting head comprises a tree-carrying frame with a cutting tool in the form of a rotor with helically extending cutting teeth. An arm for placement against a standing tree to be cut is pivotally mounted to the tree-carrying frame. A fluid ram is connected between the arm and the tree-carrying frame to bring it in engagement with the tree to be cut so that the rotor progressively cuts the tree and the latter enters the tree-carrying frame.

Abstract: A forest machine with a crane comprises a driver's cab (2) which is mounted on a wheeled chassis (1) and behind which a load carrier (3) is placed, and a crane post (10) mounted in association with the cab and rotatable relative to the chassis and carrying an outer boom (11) having a telescopic boom (16) which is arranged at its free end to carry a working tool (21). The crane post (10) comprises two suitably inclined, spaced-apart support arms (12) between which extends a pivot shaft (13) on which the outer boom is mounted in a position between the support arms. The pivot shaft (13) is located at a distance from the center of rotation of the post (10) exceeding half the distance between a pair of wheels carrying the chassis of the machine. The outer boom is movable through at least 90.degree. between a horizontal and a vertical position, more precisely by means of a hydraulic cylinder (19).

Abstract: A machine for harvesting and cutting into sections ligneous stems which grow upwardly from cultivated copses includes a frame which mounts an inverted trough for bending the upper portions of the stems to almost an almost horizontal orientation as the frame moves forwardly; a saw for cutting the bent stems near their bases; a counter blade which provides a plurality of guide funnels that are generally vertically oriented and which have upper outlet orifices with sharp edges; a curved guide element along which the cut stems can move and gather into bundles for movement to and through respective guide funnels of the counter blade; a rotating drum for moving the cut stems along the guide element; and a drum with peripheral blades which pass over the outlet orifices of the guide funnels in the counter blade to cut the bundles of stems passing through the outlet orifices into sections.

Abstract: An improved tree-felling apparatus which can be mounted to a motive power device such as a tractor, includes a cradle having upper and lower saddle members for receiving a tree, a plurality of grab arm members for pulling the tree in toward the saddle members, a pivotable chain saw bar mounted in the lower saddle member and an extendable penetrating tree spike retractably mounted within a recess above the chain saw bar for securing the tree against downward movement during cutting.

Abstract: A tree felling head has a frame with two laterally spaced-apart support means at the bottom of the frame. A cutting unit is pivotally mounted at one end on one of the support means while the other end of the cutting unit is supported on the other support means. The cutting unit carries a rotatable cutting bar. Means pivot the cutting unit, while its other end is guided on the other support means, and while its cutting bar is rotated, to move the cutting bar against a tree and to cut through it.The cutting unit also has an accumulating plate located immediately behind the cutting bar for accumulating cut trees thereon.

Abstract: A tree felling apparatus mountable to a vehicle includes a frame defining an opening for receiving a tree and a chain saw mounted for linear movement across the opening for felling the tree. One side of the opening is defined by an anvil having a sharpened edge for increasingly engaging the tree as the frame is advanced to receive the tree within the opening. The sharpened edge also extends sufficiently so that it overlaps the leading edge of the chain saw as the saw completes its cut. The anvil thus serves as a stationary, stable pivot point for the falling tree and protects the underlying chain from the force of the falling tree. Wedges are spaced across the saw bar of the chain saw for directionally felling the tree.

Abstract: The invention relates to a method for thinning a forest by means of a wheeled harvester and a wheeled forwarder comprising a driver's cab and a load carrier located behind the cab. The harvester (3) is caused to advance in existing forest stands (1) in routes optimally selectable with regard to the characteristics of the stand, between main haul roads or strip roads close to each other, and is parked on suitable places along the routes for felling trees on each parking place. The trees are limbed and placed underneath the harvester between the wheels thereof, and the forwarder (4) is caused to follow the harvester in the same route as this and take care of the tree stems placed underneath the harvester and left behind it. This is achieved in that the felled trees lying in front of the forwarder are lifted by it and moved over and rearwards past the cab of the forwarder to the load carrier situated behind the cab.

Abstract: An improved ring saw having a disk-shaped saw body with a cutting ring mounted to rotate about the saw body. The cutting ring has an inwardly directed flange that fits within a slot in the peripheral edge of the saw body. Cutting teeth are mounted in the ring. Drive means mounted on the saw body rotate the cutting ring about the saw body to have the saw cut into a tree as the saw body is moved toward the tree.

Abstract: A machine for felling and shaping trees is provided with a work head susped by at least two perpendicular joints one of which makes possible its horizontal swivel and the other a certain angular freedom in the vertical plane and carried by a frame consisting of a beam comprising at least a free space intended to neutralize the joint of vertical angular freedom in felling position.

Abstract: A tree harvester comprises a head boom at the lower free end of which is mounted a tree felling head having a cylindrical cutting knife behind which is formed a storage enclosure for felled trees. The head includes pivotable gripping arms for pressing the cylindrical knife against the trees to be felled and for moving them and holding them in the storage enclosure.

Abstract: Tree felling apparatus having a U-shaped base with laterally spaced hollow arms defining a cutting area for receiving therein a tree to be cut and having a chain saw mechanism pivotably mounted to the base centrally between the arms for pivotal cutting movement into and out of the cutting area through the hollow area in one arm of the base. The chain saw mechanism is dimensioned to occupy substantially the full cutting area at the completion of its cutting stroke, and has a distal transverse support flange adapted to be supported at its opposite ends within the hollow areas of each arm at the completion of the cutting stroke to assist the pivotal sw mounting in supporting and stabilizing the chain saw mechanism against damage by the tree.

Abstract: This invention relates to a tree pruning machine comprising a frame in a cutting unit having a first member mounted to a body having wheels elevating vertically, and a second member projecting from the top of the first member forwardly in an ascent gradient and forming a recess at the front side, the first member having drive wheels mounted on the lower portion thereof and driven by an engine, and a saw chain rotated by the engine through the drive wheels along the frame formed by the first and second members for cutting a branch of a standing tree. Furthermore, the tree pruning machine includes a branch sensing member telescopically provided in the lengthwise direction of the second member of the cutting unit, the front of the sensing member projecting forwardly of the second member for temporarily stopping the drive of the pruning machine toward the upward direction of the standing tree.

Abstract: A tree cutting and collecting apparatus. The apparatus comprises a boom and means intermediate the ends of the boom for use in mounting the apparatus on a vehicle for rotation about an upright axis. A circular saw is mounted at one end of the boom to cut down trees as the apparatus is rotated. A tree collecting basket forms part of the apparatus, the basket located behind the saw, and above and generally parallel to the boom. Pusher means are provided adjacent the saw for toppling trees just cut by the saw into the basket.The invention is also directed toward a machine incorporating the above apparatus, and to an off-road vehicle which can be used with the apparatus.

Abstract: A simple, rugged, compact and reliable apparatus (20, 54, 55, 56, 58, 64) for cutting trees (24), vegetation and other objects, together with methods for operating such apparatus, are provided wherein a cutting blade (22, 22"), constrained for movement along a cutting path generally transverse to the tree (24) or other object being cut, is coupled to a piston/cylinder type accumulator (42/44, 42'/44', 42"/44") within which a compressible medium defines a source of stored potential energy.

Abstract: A saw carrier assembly has a loop of saw chain and a powered sprocket to drive the saw chain. The assembly also has a saw chain journalling structure having a rotatable circular periphery cooperating with the saw chain to mount the chain to rotate therewith to reduce friction and to resist sawing forces. The saw journalling structure and sprocket cooperate with a saw support structure so that the chain saw extends as a loop around the sprocket and journalling structure. The journalling structure has a thickness less than the kerf produced by the saw to permit a portion of the saw journalling structure to pass into the kerf with negligible interference therewith. This enables a tree to be cut using a saw journalling structure of slightly less diameter than diameter of the tree where it is cut, and reduces frictional losses normally associated with a fixed chain saw support bar.

Abstract: A tree felling head which includes a frame having a grapple mounted thereon with a grapple jaw which may be selectively opened and closed to respectively receive and grasp a standing tree and power means to selectively open and close the grapple; and a severing device mounted on said frame below said grapple for severing a standing tree. The severing device is a rim driven planar circular saw mounted around a peripheral portion thereof on an arm pivotally attached to the frame for movement in a plane transverse to the length of the standing tree, and included is a second power means for effecting rotation of said severing device.

Abstract: Tree harvesting device is connected to a mobile vehicle by means of a jib (1) and comprises means for cutting, felling and debranching a tree. The device (2) has a general U-shaped frame comprising two side parts (3, 4), rear part (5) and an open front side (6). The cutting means (7, 8), the conveying means (11, 12) and debranching means (14, 15) being attached to the side parts (3, 4). The felling frame (19-23) is attached to the rear part (5) of a turnable means (28) in order to turn the device (2) in the transversal plane with respect to the vertical plane in the longitudinal direction of the jib (1). The felling frame (19-23) being connected to the jib (1) turnable in the vertical plane in the longitudinal direction of the jib (1).

Abstract: The invention relates to a device at a rotator and grapple unit intended for tree handling and suspended at the end of a boom. The rotator (8) and grapple (11) are connected each to a pair of flexible operating lines (6,7 and, respectively, 9,10) from a hydraulic pump (1) via a control valve (3). For rendering possible completion of the unit with a hydraulic sawing device without adding two additional hydraulic hoses for this purpose, which would give rise to problems due to the combined bending and rotary movement at the crane tip and resulting heavily increased strains and wear on a bundle consisting of six hoses, according to the invention a branch line (13) is taken from the operating line (10) used for closing the grapple (11), which branch line is located in a place after the rotator (8). The branch line (13) extends to a hydraulic sawing device (15,16) via a pressure-sensing valve (14).

Abstract: A tree harvesting machine is disclosed which is of the type having a wheel-mounted frame, a tree harvesting mechanism at the front and a berth at the rear for accumulated felled trees. An inverted tree grapple is provided forwardly of the berth and is mounted to the berth so that it can be slid to and from the berth whereby the grapple may be held close to the berth during accumulation of felled trees and moved away from the berth when loaded. In this last position, the center of gravity of the load has thus been shifted forwardly. The berth itself is pivoted to the frame to allow loading to take place in rearwardly inclined position. Once loaded, the berth may then be uprighted easily since the center of gravity of the load has shifted forwardly.

Abstract: A grab-type tree harvester for processing trees comprises rotation means and a frame. The frame is connected to lifting means through the rotation means, in a manner such that the frame is adapted to rotate about a substantially vertical axis. The frame comprises grab means which are selectively moved by actuation means to an open or closed position, roller means for pulling a felled tree through said grab means, and at least one means for pruning the felled tree. The grab-type tree harvester is also provided with a jib that is pivoted on the frame and which, when a standing tree is being felled, is adapted to turn to a position substantially parallel to the tree being felled, by the aid of turning means. The jib is provided with means for gripping the standing tree, and also with sawing means for cross-cutting the standing tree.

Abstract: A cutting apparatus designed to produce an oscillating force which is transmitted to a cutting element, said cutting element having a plurality of cutting teeth disposed at intervals in a complete circle around the periphery of the cutting element. The direction of cutting of the cutting teeth of said cutting element is alternated in opposite directions so that when to the cutting element is applied an oscillatory force, half of the cutting teeth will cut in one direction and the other half in the opposite direction. Thus the cutting apparatus disclosed herein is designed to work with any oscillating flexible cutting element of the type described above.

Abstract: There is provided a felling head for attachment to a boom. The felling head includes an upper part and a lower part. The upper part has at least one brace portion and a grapple adapted to clasp a tree trunk against the brace portion. The lower part includes a circular saw blade mounted in a plane perpendicular to the longitudinal axis of a tree clasped between the brace portion and the grapple. The leading edge of the circular saw blade projects beyond the location of the brace portion by a distance at least as great as the diameter of a tree being felled so that such tree can be cut through by the saw blade before the tree comes into contact with any other part of the felling head, including the brace portion.

Abstract: A felling head for use in harvesting trees. The felling head carries a pair of circular saws and means for positioning and gripping a tree to be felled. The saws are rotated and moved relative to the positioning and gripping means to, between them, cut through a positioned and gripped tree.