METHOD FOR FELLING TREES TO DELIMB AND CUT THEM AND AN ANCILLARY DEVICE FOR THIS PURPOSE

Abstract: The invention relates to a method for felling trees to delimb and cut them, in which case the tree is felled and held in a raised position with the aid of an ancillary device (1) to facilitate delimbing and cutting. According to the invention, the ancillary device (1) is attached to the butt (2) of the tree above the cutting point, after which the tree is felled along with the attached ancillary device (1) in such a way that the butt (2) of the tree remains raised on the ancillary device (1). The invention also relates to an ancillary device (1) for this purpose, in which there is a base (3) and a component supporting the felled tree on the base (3), which according to the invention is a grip member (4), by means of which the ancillary device is attached to the tree in such a way that the base (3) of the ancillary device extends from the butt (2) of the felled tree to absorb the impact on the butt of the felled tree.

Description: METHOD FOR FELLING TREES TO DELIMB AND CUT THEM AND AN ANCILLARY DEVICE FOR THIS PURPOSE The present invention relates to a method for felling trees to delimb and cut them into lengths and particularly such a method in which the tree is felled and the butt of the felled tree is held off the ground with the aid of an ancillary device, in order to facilitate delimbing and cutting the felled tree. The invention also relates to an ancillary device intended for use in the aforesaid method, in which there is a base and a component that rests on the base and supports the tree. Delimbing stands, which facilitate delimbing and cutting of a felled tree and, which comprise a base and a rotatable roller on the base, on top of which the trunk of a felled tree is lifted and along which roller the trunk can be moved as delimbing and cutting progresses, are previously known from SE publications 449581 and 453060. Thanks to the delimbing stands, the working height is brought to a suitable level. However, it is usually difficult to fell trees so that their butts hit the roller on the base and remain there after felling, instead, the butt usually has to be lifted onto the delimbing stand after the tree has been felled. The butt of the tree may also be damaged when the tree is felled and swing to the side, endangering the feller. The present invention is therefore intended to eliminate the drawbacks in the previously known delimbing stands and create the method referred to in the preface for felling trees to delimb and cut them. The invention is also intended to create an ancillary device for this purpose, in which ancillary device there is a base and a component that rests on the base and supports the felled tree. The principal characteristics of the invention are stated in the accompanying Claims. The present invention is based on the realization that, if the ancillary device that keeps a felled tree raised off the ground is attached to the butt of the felled tree above the point at which it is cut, the tree can be felled gently and without damage, in such a way that the felled tree remains raised by the ancillary device, without any need to lift it again onto the ancillary device. According to one particularly advantageous embodiment of the invention, one or more other trees are felled after this across the felled tree that is raised on the ancillary device, and the trees on top are delimbed and cut first. In one embodiment of the invention, the felled tree is rolled sideways, on ancillary device that are attached to its butt and essentially surround the butt of the felled tree or ancillary devices that surround the butt circumferentially, to a suitable place for felling other trees. Thus, in the ancillary device according to the invention, there is a base that raises the felled tree off the ground and a grip member that supports the felled tree on the base, by means of which the ancillary device is attached to the butt of the felled tree, so that the base protrudes from the butt, absorbing the impact on the falling tree and preventing the butt from swinging. Thanks to the grip member, the felled tree remains on the base, without having to be lifted onto it. In the preferred embodiment of the invention, the base is formed by the arms of a pincer member, and the grip member by the jaws of its throat, the arm- aw pair of the pincer member being connected by a pivot axle and the throat being dimensioned according to the thickness of the butt of the largest tree to be felled. There are preferably at least two pincer members, in which case they are pivoted at opposite ends of the same longitudinal pivot axle, at a distance from each other. To stiffen the construction of the pair of pincer members, the jaws that are on the same side of the plane running through the pivot axle and throats are preferably connected to each other by means of connecting bars running parallel to the pivot axle. For the same reason, it is preferable to connect the arms that are on the same side of the plane running through the pivot axle and throats to each other at their lower ends. When a tree is felled, extremely effective absorbing is created, if the arms on the same side of the plane running through the pivot axle and throats are connected to form a unified arc, for example, an arc with an approximately semicircular shape. There is preferably a spring member between the components on the pincer member that turn in relation to each other, for example, a coil spring fitted to the pivot axle and acting against the ends of these components, to force the jaws of the pincer member towards each other, to grip the tree and secure the ancillary device to the tree. In the following, the invention is examined in greater detail with reference to the accompanying drawings, in which Figure la shows a tree to be felled, with an ancillary device according to the invention attached to it and extending from the trunk, Figure lb shows the same tree felled and with its butt raised on top of the ancillary device while Figure lc shows the same felled tree as in Figure lb, with other trees felled across it, Figure 2 shows a part view of the end of an opened preferred embodiment of the ancillary device according to the invention, Figure 3 shows a side view of the same device, and Figure 4 shows a perspective view of the ancillary device of Figures 2 and 3 gripping a tree. Figure la shows how the ancillary device 1 according to the invention is attached to the butt 2 of the tree, so that the base 3 of the ancillary device 1 extends laterally from the tree's butt 2. As can be seen from the following figures, the base 3 consists of two curved components set at angle to each other in such a way that, when the tree is felled, its butt 2 remains raised off the ground on the forks of the base 3, as shown in Figure lb. The butt of the felled tree then remains about 80 - 100 cm above the ground, most of the trunk thus remaining at an ideal delimbing height above the ground, thanks to the raising effect of the branches. If there are other trees to be felled close to the felled tree resting on ancillary device 1, these can be felled across the tree resting on the base 3 of the ancillary device 1, preferably overlapping each other, (Figure lc) . The uppermost felled tree is delimbed and cut first, the tree resting on the ancillary device 1, which has acted as a work base for the other trees, being delimbed and cut last. Figure 2 shows that the grip members of the ancillary device 1 according to the invention is formed by a pincer member, in which the base of the ancillary device is formed by the arms 3 and the grip member by the throat, in which there are jaws 4. The jaws 4 are at one end of the arms 3 and each arm-jaw pair 3, 4 is connected rotatably to each other by a pivot axle 5, so that when the arms 3 are forced away from each other, the jaws Figure 3 shows in greater detail that the grip member of the ancillary device 1 is formed by a pair of pincer members, which are at each end of a pivot axle, with the opposing jaws 4 of the pairs of pincer members on the same side of a level running through the pivot axle 5 and the throats being connected together by a connecting bar 6, to stiffen the construction. The arms 3 of the base are connected to each other in the same way, so that the arms 3 on the same side of the place running through the pivot axle 5 and the throats form a unified arc, as clearly shown in Figure 3. The curved shape dampens the impact on the tree's butt 2 caused by the tree falling. Figure 4 shows the construction of the pincer members of the ancillary device 1 in detail. The figure shows how the arm-jaw pair 3, 4 of the pincer member is pivoted on a pivot axle 5 common to both pincer members, a coil spring 7 being also fitted to it so that its ends are against the arms 3, to press the jaws 4 against the butt 2 of the tree that is between them, to secure the ancillary device to the tree. Working with the ancillary device 1 according to the invention takes place by the lumberjack first delimbing the butt 2 of the tree to a height of about two metres, after which ancillary device 1 is attached to the butt above the felling point so that the arms 3 of the base of the ancillary device 1 point in the felling direction. The attachment of ancillary device 1 to the butt 2 takes place by the curved arms of the base being forced against the effect of the springs 7 to open the jaws 4 enough to allow the butt 2 of the tree to be inserted in the throat formed by the jaws 4, after which the arms 3 are released, when the ancillary device 1 grips the tree. After this, the lumberjack fells the tree. If pieces of timber of a set size are being made, a measuring tape is attached to the tree and delimbing is carried out while simultaneously marking the cutting points on the trunk. Finally, the ancillary device 1 is removed from the butt, by forcing the arms 3 of the base towards each other, so that the jaws 4 of the throat of the grip member move away from each other enough to allow the butt 2 to be removed from the throat. The ancillary device according to the invention can be manufactured from steel or a light metal alloy, so that its weight remains less than 8 kg, and it is intended to facilitate the use of a chain saw to delimb, cut, and preliminarily stack a small tree (diameter about 7 - 15 cm) in the forest, by saving above all the lumberjack's back and the chain of the saw. The ancillary device is preferably made from high-strength steel. This material is work-hardened, especially when manufacturing the arcs (the base in general) . For this purpose, one or several longitudinal joggles (a kind of groove) can be formed in the arc. It is clear to one versed in the art that the method and device according to the invention can be varied within wide limits within the scope defined by the accompanying Claims. Thus, it is for example obvious that the ancillary device may have only a single pincer member, in which case, however, it is preferable for there to be a component supported against the surface of the butt, which will prevent the ancillary device from turning in relation to the butt and the throat thus opening unintentionally. It is also obvious that the part of the base resting on the ground may have a shape other than a arc, though a curve is the preferred shape for dampening an impact. In practice, it has also been observed that the arced legs can be used as skis, on which the tree can be moved in the forest. The ancillary device can also be equipped with a locking member, which is used to lock the arms to each other in the transportation position, in which the ancillary device takes up very little space.

Claims: Claims 1. A method for felling trees to delimb and cut them, in which case the tree is felled and the butt (2) of the felled tree is held in a raised position with the aid of an ancillary device (1) to facilitate delimbing and cutting, characterized in that the ancillary device (1) is attached to the butt (2) of the tree above the cutting point, after which the tree is felled along with the attached ancillary device (1) in such a way that the butt (2) of the tree remains raised on the ancillary device (1). 2. A method according to Claim 1, characterized in that one or several other trees are felled across the felled tree the butt of which is raised on the ancillary device (1) . 3. A method according to Claim 2, characterized in that the felled tree is rolled on the ancillary device attached to the butt and essentially surrounding the tree or on ancil- lary devices surrounding the tree circumferentially to a suitable spot in terms of the felling of other trees. 4. An ancillary device (1) for delimbing and cutting a felled tree, in which there is a base (3) and a component supporting the felled tree on the base, characterized in that the component supporting the tree on the base is a grip member (4), by means of which the ancillary device is attached to the tree in such a way that the base (3) of the ancillary device protrudes from the butt (2) of the felled tree to absorb the impact on the butt of the felled tree. 5. An ancillary device according to Claim 4, characterized by a pincer member, the arms (3) of which form the said base and the jaws (4) of the throat form the said grip member, the pair of arms-jaws (3, 4) of which pincer member are connected to each other by a pivot axle (5) and which throat is dimensioned according to the butt (2) of the largest tree to be felled. 6. An ancillary device according to Claim 4, charac- terized by two pincer members, which are pivoted around the opposite end of their common pivot axle (5) at a distance from each other. 7. An ancillary device according to Claim 6, charac- terized in that the jaws (4) on the same side of the plane running through the pivot axle (5) of the throats of the pincer member and the throats are connected to each other with connecting bars (6) parallel to the pivot axle (5). 8. An ancillary device according to Claim 6 or 7, characterized in that the arms (3) on the same side of the plane running through the pivot axle (5) of the pincer member and the throats are connected to each other at their lower ends . 9. An ancillary device according to Claim 8, characterized in that the arms (3) on the same side of the plane running through the pivot axle (5) of the pincer member and the throats are connected to form an arc, preferably an arc with a more or less semicircular shape. 10. An ancillary device according to one of Claims 6 - 9, characterized by spring members (7) between the components (3,4 / 3,4) that turn in relation to each other, to force the jaws (4) of the throat towards each other to grip the tree. 11. An ancillary device according to one of Claims 3 - 10, characterized by at least the base (3) being manufactured from high-strength steel and having in it work-hardened components, such as longitudinal joggles.

Inventors: RIEKKO PEKKA, RIEKKO, PEKKA
Applicants: RIEKKO PEKKA, RIEKKO, PEKKA
Application year: 2001
Main classification: A01G23
IPC codes: A01G23