Device and method for felling a tree, vehicle

Abstract

The invention relates to a device and a method for felling a tree, comprising movable gripping arms (22, 24) for grasping a tree trunk (4) and at least one felling tool (42) for acting on the tree trunk (4). According to the invention, two rear gripping arms (24) and two front gripping arms (22) arranged opposite the rear gripping arms (24) are provided and arranged and movable in such a way that the rear gripping arms (24) and the front gripping arms (22) act against each other with respect to an axis of the tree trunk (4) and can align the tree trunk (4) in a position in which the at least one felling tool (42) can make a felling cut at the intended depth relative to the diameter of the tree trunk (4), with which the tree trunk (4) is separated from the root to such an extent that a hinge remains.The invention also relates to a vehicle comprising a movable crane boom with which a device for felling a tree can be carried in a pendulum-like manner and positioned on a tree trunk.

Description

[0001] The invention relates to a device and a method for felling a tree, comprising movable gripping arms for grasping a tree trunk and at least one felling tool for acting on the tree trunk, as well as a vehicle comprising a movable crane boom.

[0002] Forestry work is one of the most dangerous occupations. The most serious consequences occur primarily during processing, delimbing, and segmenting of felled logs (28% of all accidents during manual work) and felling (18%). Therefore, for the past two decades, efforts have been made to have logging carried out, wherever possible, by machines such as harvesters, also known as timber harvesters, in which the operator sits in a cab and is largely protected from falling logs or crowns. The use of harvesters and forwarders (short-log skidders) has proven effective not only in coniferous forests but also in smaller-diameter deciduous trees and is the standard procedure in Germany on accessible sites. However, in dense deciduous stands or on inaccessible sites, manual felling and processing remain the standard.

[0003] The process is as follows. The lumberjack makes two cuts to create a felling notch in the trunk, approximately 1 / 4 to 1 / 5 of the tree's diameter deep. These cuts form the bottom and top of the felling notch, which meet at the felling notch chord. The felling notch chord defines the direction of fall, which is perpendicular to it. The lumberjack then makes the felling cut on the back side of the tree, 1 / 10 of the tree's diameter higher than the felling notch chord and deep enough to leave the same amount of the trunk intact. This remaining slab, the hinge, acts as a hinge. To prevent the chainsaw bar from binding when making the felling cut, a felling wedge is placed opposite the direction of fall. After completing the sawing, the lumberjack begins to wedge the tree by driving in the felling wedge until the tree's center of gravity slowly shifts over the hinge and the tree begins to fall.This is the only method for felling a tree safely and precisely. Any geometric or structural change to the method will result in the tree falling uncontrollably.

[0004] All state-of-the-art harvesters for harvesting sawlogs and large energy wood (diameter at breast height > 30 cm) follow the same basic technological principle: A harvester head is brought to the tree to be felled by means of a crane arm on a base machine. It grips the tree with several arms shaped like delimbing knives, which press the tree against a support surface of a frame. The tree is then cut from the stump with a swiveling chainsaw, lifted by the crane, and subsequently placed in a controlled position. The depth of the felling cut cannot be controlled; it only needs to be deep enough to cut the full circular cross-section, even with the largest trunk diameter to be felled. Therefore, notch cuts or felling cuts with a defined depth cannot be made.

[0005] Common harvester heads can be divided into two types. There are lightweight and simple heads for pulpwood or energy wood. These only collect or fell thin, crooked, and low-quality timber. They do not require a felling or delimbing device. In addition, there are heads for sawlogs (from 30 cm DBH), which require fine delimbing with delimbing knives and a clean felling cut with chainsaws. The delimbing knives are therefore optional, and the chainsaw is one option (others include circular saws or guillotines). Using the harvester's crane arm, the head performs further operations such as delimbing, measuring, cutting, and stacking.

[0006] For physical reasons, the base machines must be heavy and inevitably cause long-lasting ecological disturbances on the loose forest floor. The required weight of the base machines results from the fact that the harvester head, which usually weighs between 600 kg and 2000 kg, is attached to the crane tip with a standard reach of 10 m and must be positioned by the harvester on both sides of the stand.

[0007] In Central Europe, where forest soils are sensitive to vehicle traffic, the approach taken is to avoid widespread vehicle traffic by concentrating it on a long-term, established system of skid trails up to 4 meters wide and, due to the crane's 10-meter reach, usually spaced 20 meters apart. These designated skid trails ensure that the production area between them remains untouched by any vehicles. To further reduce the unused production area of ​​the skid trails, the distances between them are increased. With this access method, the area to be worked is divided into two zones: the crane zone, with the central skid trail and outer boundaries defined by the crane's reach, and the intermediate zone, which is inaccessible to the crane.

[0008] However, since in this case there are still forest strips approximately 16 m wide lying between the accessible areas, efforts are being made to find alternative forestry methods that allow greater silvicultural freedom and on which the loss of production area is reduced.

[0009] In the intermediate zone, the trees must be felled manually by a feller towards one of the adjacent lanes so that they can be picked up by the harvester and processed further. However, the feller is subject to the aforementioned hazard.

[0010] Attempts to mechanize the felling process failed, however, because all known concepts for mechanizing felling are based on the aforementioned principle: a felling head grips the tree, severs it from the root, lifts it from the stump, and lays it down. To generate the necessary force, this principle can only be used in the crane zone and in combination with sufficiently heavy machinery.

[0011] Small forestry crawlers are already available on the market and are known according to the state of the art. However, these can only be used for moving felled trees forward or for pulling down trees that have already been felled but are stuck in the crown of a neighboring tree using a cable winch. These forestry crawlers have a low contact pressure, which allows them to be driven over large areas, but at the same time they are too light to take over the function of a harvester.

[0012] Furthermore, a tree felling attachment modeled on manual felling is known from publication NZ 717 787 A. This attachment involves grippers pressing the trunk against a support surface of the frame. The depth of the felling cut must be actively controlled by first determining the trunk diameter and using this value to control the felling saw. This active control requires not only sensors, but also resistance to flying sawdust, resin, and mechanical and thermal influences. These requirements often lead to the failure of such automation solutions. Moreover, positioning the tools in three-dimensional space is complex and prone to malfunctions, in addition to the high mass and large space requirements. Therefore, notch or felling cuts of a defined depth can only be produced with a complex and unreliable system.

[0013] The prior art also includes publication US 2018 0 125 007 A1, which discloses a felling head with two pairs of grippers that can be moved independently of each other and grip the trunk(s) from the front and the side, respectively. Publication DE 10 2016 114 579 A1 also shows a felling head with two pairs of grippers that improve and simplify delimbing, but otherwise do not change the working method when felling with a conventional harvester. Publication DE 25 08 207 A1 describes a machine for felling and processing trees, comprising a felling head. Its pair of grippers is coupled by tooth segments so that opening and closing are synchronous. The latter three publications also do not involve a change in the working method when felling; the felling head is used with a conventional harvester in each case.

[0014] The invention is therefore based on the objective of mechanically replicating the felling technique of the forest worker, which has proven itself for decades and ensures a safe, controlled fall with low force input, using a simple and safe method, and of felling trees in such a way that the operator can remain at a safe distance from the danger zone.

[0015] The problem is solved by a device for felling a tree, comprising movable gripping arms for grasping a tree trunk and at least one felling tool for acting on the tree trunk. According to the invention, two rear gripping arms and two front gripping arms arranged opposite the rear gripping arms are provided. These are arranged and movable such that the rear gripping arms and the front gripping arms act against each other with respect to an axis of the tree trunk. They can align the tree trunk, depending on its diameter, in a position in which the at least one, in particular stationary, felling tool can make a felling cut that separates the tree trunk from the root to such an extent that a hinge bar, which functions as a hinge, remains.

[0016] A notched cut and the felling cut are arranged in such a way that a hinge, a hinge joint, is formed by a surface one plank's thickness, which keeps the tree trunk connected to the root and, through this connection, creates the hinge joint. The position of the hinge joint relative to the trunk diameter is always essentially the same and should always be at about 1 / 4 of the diameter. This means that the depth of the felling cut is about 3 / 4 of the trunk diameter.

[0017] In a known prior art harvester head, the felling tools are fixed in position relative to the harvester head, and the tree is always against the back of the head and gripped only by movable front arms. Such an arrangement would lead to varying cutting depths depending on the trunk diameter, which is the objective of the present invention. Making the tools movable to adapt to different trunk diameters would result in a high degree of control and bearing complexity.

[0018] However, it has surprisingly been found that it is advantageous not to position the tools relative to the tree, but instead to position the tree relative to the tools using a coupled arm movement of all gripping arms. This was achieved by providing rear gripping arms according to the invention, and by making these arms movable.

[0019] It has proven advantageous to use positive guidance for the gripper arms via gripper coupling gears. This reduces the number of drives, ideally to a single drive, while simultaneously achieving greater gripping stability.

[0020] Instead of using just one felling tool, such as a chainsaw, the use of two or more shorter felling tools is also permitted. Each of these works on a section of the trunk cross-section to be cut.

[0021] To fully replicate manual felling techniques while avoiding the need for significant pivoting of a single felling tool, a separate notching tool is provided. This tool is guided by a gear mechanism in such a way that two felling notches—a horizontal felling notch base and, at an angle of approximately 45° to it, a felling notch roof—can be cut into the base of the trunk. This creates the conditions necessary to fully replicate manual felling techniques and fell the tree in the intended direction.

[0022] The notching tool's gear assembly comprises two scaled and positively guided notching coupling gears, which can be moved in front of the tree trunk via a skewed joint, preferably extending from a protective housing. The notching coupling gear is a Watt linear guide or a substitute gear for one, which follows a lemniscate at the coupling center. The scaling of two of these gears achieves a preferred axis guidance such that a saw blade executes both felling notch cuts and the pivoting action between them without any tilting of the saw blade. For convenient storage of the saw blade and gearbox, the assembly is folded around a skewed joint. This solution requires only two individual drives, but numerous joints, to execute the felling notches.

[0023] An alternative design of the gear arrangement uses a combination of linear and rotary drives, with which the felling notch cuts are executed as a sequence of linear cuts followed by a pivoting motion around a felling notch chord. This solution requires three individual drives but only a few joints.

[0024] By moving the notching tool, for example, a notching saw, using a gear arrangement or a combination of linear and rotary drives, it is advantageously possible to retract the notching tool or saw into a protective chainsaw case and stow it there, thus protecting it from damage. It is then in the stowed state when the felling unit is moved towards or away from the tree. In both variants of the notching tool and its gear arrangement, the stowing of the saw blade, which initially stands transversely to the direction of the tree's fall, is achieved with the aid of a skewed joint.

[0025] It has also proven advantageous to use a linear guide that directs the felling tool during the felling cut. This allows for a straight cut, optimally aligned with the felling notch. The trunk is not completely severed from the root but remains intact at the hinge, which acts as a pivot point. The hinge guides the tree as it falls and only breaks when the top of the felling notch meets the bottom. At this moment, the wedge-shaped gap created by the felling notch cuts closes. The tree is then just about to hit the ground and is no longer deflected by surrounding trees. It is also no longer pushed back in an undesirable direction.

[0026] An advantageous embodiment of the present invention provides a first protective housing and a second protective housing for the felling tool, also referred to as a saw housing. During the felling cut, the felling tool is guided from the first protective housing or saw housing into the second protective housing or saw housing. Thus, the felling tool is protected in every end position.

[0027] Advantageously, at least one felling tool and / or notching tool is designed as a chainsaw, preferably hydraulically driven.

[0028] It has proven advantageous to have a wedge device by which the felling cut can be kept open for the felling tool and subsequently the wedge work to guide the center of gravity of the tree beyond the hinge can be accomplished so that the tree falls.

[0029] Preferably, the wedge device is designed as a hydraulically driven drill cone, which includes a wedge coupling mechanism for quasi-linear guidance. The wedge device, or drill cone, can be stowed away in a space-saving manner using the wedge coupling mechanism, by pivoting around at the end of the stowing process to make room for the felling saw. Furthermore, the coupling movement prevents the felling saw from contacting the drill cone, even though both are positioned close together in the felling cut.

[0030] A pressure switch is particularly advantageous, as it detects the moment the tree begins to fall. When the wedge device loses its power at that moment, the unit is retracted, which can also be automated.

[0031] Another aspect of the present invention relates to a method for felling a tree. According to the invention, a device according to any one of claims 1 to 12 is used. The method comprises the steps: • Fixing and aligning the device on the tree trunk using movable gripping arms; • Creating a felling notch from a trunk base by cutting the felling notch roof and felling notch base using a notching tool at a predetermined angle of approximately 45° on the side of the tree trunk in the direction towards which the tree is to fall; • Making a felling cut using a felling tool on the side opposite the felling notch, so that approximately 1 / 3 of the remaining tree surface remains intact, i.e., the felling cut is not fully completed, as otherwise the tree could fall prematurely or sit on the saw. • Inserting a wedge device during the felling cut to keep the felling cut open for the felling tool; • Completion of the felling cut as soon as the drill cone has been inserted into the felling cut made for this purpose; • Opening of the gripping arms; • Lifting the tree past the tipping point after completion of the felling cut using the wedge device, so that the tree is levered over with comparatively low forces by the wedge device penetrating further into the felling cut, for example turning it, and levering the tree out until it falls on its own and • Breaking all contact with the tree and removing the device from the danger zone the moment a pressure switch detects that the drill cone is powerless and the tree is beginning to fall, and at that moment the crawler moves away, e.g. automatically by 3 m backwards.

[0032] Another aspect of the present invention relates to a vehicle comprising a preferably multi-movable crane boom. According to the invention, a device according to any one of claims 1 to 12 can be supported by means of the crane boom in a pendulum-like manner and positioned on a tree trunk. Preferably, the vehicle is designed as a tracked vehicle.

[0033] The present invention of a felling unit for the aforementioned intermediate zone, carried by a lightweight forestry tracked vehicle, is the solution to the problematic situation described above. With the aid of the forestry tracked vehicle, also according to the invention and preferably simultaneously providing the power supply to the felling unit, the felling technique of the forest worker is mechanically replicated. This felling technique has proven itself for decades and ensures a safe, controlled fall with minimal effort from sawing and wedging. The attachment is intended to enable the tracked vehicle to fell trees remotely, allowing the operator to remain at a safe distance from the danger zone. The present invention aims to solve the problem of mechanically felling trees using a comparatively lightweight forestry tracked vehicle.With the help of a special felling head carried by the forestry crawler, the motor-manual felling technique is to be carried out in a fully mechanized and safe manner.

[0034] Furthermore, only with a mechanized solution according to the present invention is it possible to create a standardized and repeatable cut. With manual methods according to the prior art, deviations from the optimal felling geometry inevitably occur, for example, a hinge that is too thick or too narrow. This can pose a hazard, as the tree may then fall immediately and unexpectedly, or only after lengthy wedging work, which represents avoidable rework on the tree ready for felling.

[0035] The invention is explained in more detail below with reference to the description of exemplary embodiments and their illustration in the accompanying drawings. The drawings show: Fig. 1: a schematic perspective view of an embodiment of a device according to the invention for felling a tree from the gripper side; Fig. 2: a schematic perspective view of an embodiment of a device according to the invention for felling a tree from the frame side; Fig. 3a and Fig. 3b: a schematic view of an embodiment of a device according to the invention for felling a tree from above, with open and closed grippers; Fig. 4: a schematic representation of the movement sequence of the notching tool; Fig. 5: a schematic perspective view of an embodiment of a device according to the invention for felling a tree during the production of the felling notch cuts; Fig. Figures 6a to 6c: a schematic perspective view of an embodiment of a device according to the invention for felling a tree in three phases during the production of the felling cut and Fig. 7: a schematic perspective view of an embodiment of a tracked vehicle according to the invention with a device for felling a tree.

[0036] Fig. Figure 1 shows a schematic perspective view of an embodiment of a device 1 according to the invention for felling a tree from a gripper side. A frame 2 carries the functional elements described in more detail below and also enables the device 1 to be attached to a vehicle 60 by means of a mounting plate 3 (see Figure 1). Fig. 2 and Fig. 7) can be cultivated.

[0037] A gripping device 20 is used to grip a tree trunk 4 (not shown here) (compare Fig. 3, Fig. 5 and Fig. 6) to grasp and position in a defined manner relative to the notching device 30 and the felling device 40. For this purpose, the gripping device 20 has front gripping arms 22 and rear gripping arms 24, which are shown here in the open position.

[0038] Once the log 4 is gripped and securely positioned by the gripping device 20, a first and second felling notch cut (31, 31') are made by the notching device 30. For this purpose, the notching device has a notching saw 32, which is movable via a gear assembly 34. The gear assembly 34, designed as a notching coupling gear, is housed in a gearbox 36, which serves as a protective housing 38. The notching device 30 makes two successive cuts, offset from each other at an angle of 45°, thereby cutting out a wedge on the side of the log 4 facing away from the frame.

[0039] The felling device 40 then begins to make a felling cut on the side of the tree trunk 4 facing the frame 2. This is done using a chainsaw 42, which is housed in a first saw box 44 for protection against damage. To carry out the felling cut, the chainsaw 42 leaves the first saw box 44 and, after the felling cut is completed, enters the second saw box 44'.

[0040] Fig. Figure 2 shows a schematic perspective view of an embodiment of a device 1 according to the invention for felling a tree from a frame side, from which a mounting plate 3 for attachment to the vehicle 60, the gear arrangement 34 of the notching device 30, designed as a notch coupling gear, a felling drive 43 of the felling device 40 and a wedge device 50 are clearly visible.

[0041] The wedge device 50 comprises a drill cone 52 and its wedge drive 54. A wedge coupling gear 56 enables linear guidance of the drill cone 52 up to the felling cut made by the felling device 40 or its felling tool 42. The drill cone 52 is driven into the felling cut by the wedge drive 54 in order to wedge the tree in the intended direction of fall and simultaneously keep the felling cut open for the safe operation of the felling tool 42.

[0042] The Fig. 3a and Fig. Figure 3b shows a schematic view of an embodiment of a device 1 according to the invention for felling a tree, shown from above with the gripping arms 22, 24 open and closed. Circles of different diameters represent the different diameters of the tree trunk 4 that can be felled with the device 1. The actual diameter in Fig. 3b The trunk diameter measured is indicated by a thicker line.

[0043] While in Fig. 3a the gripping arms 22 are opened so far that the device 1 can be brought unhindered to the tree trunk 4, are in Fig. 3b The gripping arms 22, 24, already closed, have grasped the tree trunk 4 and brought it into a defined position. For this purpose, the gripping device 20 has a gripper coupling mechanism 26, which ensures coupled movement and positioning of the front gripping arms 22 and the rear gripping arms 24. As a result, the tree trunk 4 assumes a defined position relative to the frame 2, in accordance with the present invention. This makes it possible to perform felling notch cuts (31, 31') and felling cuts of defined shape and depth without further adaptation of the movement sequences of the notching device 30 and the felling device 40 to the trunk diameter. This represents a particular advantage of the device 1 according to the invention and enables a simple and reliable device.

[0044] Fig. Figure 4 shows a schematic representation of the movement sequence of the notching tool 32 during the production of the felling notch cuts (31, 31') with a felling notch top, produced by a first felling notch cut 31, and a felling notch bottom, produced by a second felling notch cut 31', in the tree trunk 4, which is not shown here. The notching tool 32 is guided by the gear assembly 34, which is also not shown here. The individual phases of the production of the felling notch cuts (31, 31') are shown in Figures a) to d).

[0045] In phases a) and b), the felling notch roof is produced, with the first felling notch cut 31 already completed in figure b). The notching saw 32 then retracts from the first felling notch cut 31 and is tilted 45° around a felling notch chord 33, as shown in figure c). The notching saw 32 then retracts into the log and makes the second felling notch cut 31' for the felling notch base, as shown in figure d). The felling notch is then complete.

[0046] Fig. Figure 5 shows a schematic perspective view of an embodiment of a device 1 according to the invention for felling a tree during the production of the felling notches (31, 31') by the notching device 30. The felling notches (31, 31') are already completed, and the notching saw 32 with the gear assembly 34, the notching coupling gear, has been retracted from the felling notch (31, 31') in the gearbox 36. The felling device 40 with the chainsaw 42 is thus ready for use in order to subsequently make the felling cut in the tree trunk 4.

[0047] The Fig. Figures 6a to 6c show a schematic perspective view of an embodiment of a device 1 according to the invention for felling a tree in three phases during the production of the felling cut. For this purpose, according to Fig. 6a The gripping arms 22, 24 grasp the tree trunk 4. The chainsaw 42 cuts the tree trunk 4 so that a hinge strip remains between the felling notch and the felling cut, which acts as a hinge and guides the tree in the intended direction of fall. At the same time, while the felling cut is being made, the drill cone 52 moves into the felling cut and holds it open for the chainsaw 42.

[0048] In Fig. Figure 6c shows the situation after the felling cut has been made. The drill cone 52 is fully or largely inserted into the felling cut and levers the tree over the hinge. It is positioned by the wedge coupling mechanism 56 and pressed into the felling cut with the appropriate force by means of the wedge drive 54.

[0049] Fig.Figure 7 shows a schematic perspective view of an embodiment of a tracked vehicle 60 according to the invention with a device 1 for felling a tree, which has already been positioned on the tree trunk 4 by means of a crane boom 62. Due to the relatively low weight of the device 1, but especially because there is no longer any need to pull or support the tree trunk 4 during felling, the tracked vehicle 60 can be built very lightly. As a result, it has low ground pressure and its use avoids damage to the forest floor. Reference symbol list 1 Device 2 frames 3 Mounting plate 4 tree trunks 6 trunk diameters 20 Gripping device 22 front-facing gripping arms 24 rear gripping arms 26 Gripper coupling gear 30 Notching device 31,31' first, second drop notch cut 32 Notching tool, notching saw 34 Gear arrangement, notched coupling gear 36 Gearbox 38 protective housings 40 Felling device 42 Felling tools, chainsaw 43 Felling drive 44, 44' saw box 50 wedge device 52 drill cones 54 Wedge drive 56 Wedge coupling gear 60 tracked vehicles 62 crane booms

Claims

[1] Device for felling a tree, comprising movable gripping arms (22, 24) for grasping a tree trunk (4) and at least one felling tool (42) for acting on the tree trunk (4), characterized by , that two rear gripping arms (24) and two front gripping arms (22) arranged opposite the rear gripping arms (24) are provided and arranged and movable with respect to a frame (2), wherein the rear gripping arms (24) and the front gripping arms (22) act against each other with respect to an axis of the tree trunk (4) and can align and fix the device (1) on the tree trunk (4) in a position in which the at least one felling tool (42) can make a felling cut at the intended depth relative to the diameter of the tree trunk (4), with which the tree trunk (4) is separated from the root to such an extent that a hinge remains. [2] Device according to claim 1, wherein the gripping arms (22, 24) are positively guided via at least one gripper coupling mechanism (26). [3] Device according to claim 1 or 2, wherein a notching tool (32) is provided which is guided by means of a gear arrangement (34) in such a way that a horizontal felling notch bottom and at an angle of 45° thereto a felling notch roof can be introduced into a trunk base. [4] Device according to claim 3, wherein the gear arrangement (34) comprises two scaled and mutually positively guided notch coupling gears that follow a lemniscate, which enable guidance in such a way that the notching tool (32) performs both drop notch cuts (31, 31') and pivots between them in such a way that tilting of the notching tool (32) is avoided. [5] Device according to claim 3, wherein the gear arrangement (34) is designed as a combination of linear drives and rotary drives, with which a first and a second drop notch cut (31, 31') is performed as a sequence of linearly executed drop notch cuts (31, 31') and a pivoting of the notching tool (32) about a drop notch tendon (33). [6] Device according to claim 4 or 5, wherein, for stowing the notching tool (32) which is positioned transversely in the direction of the fall of the tree and which forms an assembly with an associated gearbox (36) which is housed in a protective housing (38), this assembly is folded over about a hinge which lies obliquely in space. [7] Device according to one of the preceding claims, wherein a linear guide is provided which guides the felling tool (42) during the felling cut. [8] Device according to one of the preceding claims, wherein a first saw box (44) and a second saw box (44') are provided and the felling tool (42) is guided from the first saw box (44) to the second saw box (44') during the felling cut. [9] Device according to one of the preceding claims, wherein the at least one felling tool (42) and / or the notching tool (32) is designed as a hydraulically driven chainsaw. [10] Device according to one of the preceding claims, wherein a wedge device (50) is provided by means of which a felling cut can be kept open for the felling tool (42). [11] Device according to claim 10, wherein the wedge device (50) comprises a hydraulically driven drill cone (52) and a wedge coupling gear (56) for quasi-linear guidance. [12] Device according to claim 10 or 11, wherein a pressure circuit is provided with the aid of which it is detected as soon as the wedge device (50) is free of force when the tree (4) begins to fall. [13] Methods for felling a tree, characterized by , that a device (1) according to one of claims 1 to 12 is used, comprising the steps: • Fixing and aligning the device (1) on the tree trunk (4) using movable gripping arms (22, 24); • Creating a felling notch from a trunk base by cutting the felling notch roof and felling notch base using a notching tool (32) at a predetermined angle of approximately 45° on the side of the tree trunk (4) in the direction towards which the tree is to fall; • Making a felling cut using a felling tool (42) on the side opposite the felling notch, leaving out 1 / 10 of the remaining diameter, so that a hinge strip remains as a hinge, • Insertion of a drill cone (52) of a wedge device (50) in the course of the felling cut, with which the felling cut is kept open for the felling tool (42); • Completion of the felling cut as soon as the drill cone (52) has entered the felling cut; • Opening the gripping arms (22, 24); • Lifting the tree over the tipping point after completion of the felling cut using the wedge device (50), which penetrates the felling cut and levers the tree until it falls on its own and • Disconnecting from all contact with the tree and removing the device (1) from the danger zone at the moment when a pressure switch detects that the drill cone (52) is powerless and the tree begins to fall. [14] Vehicle comprising a movable crane boom, characterized by, that with the aid of the crane boom (62) a device (1) according to one of claims 1 to 12 is carried in a pendulum manner and positioned on a tree trunk (4). [15] Vehicle according to claim 14, designed as a tracked vehicle (60).

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