Background of the invention

In forestry there has been attained during the last few decades a very high and efficient level of mechanization in conjunction with final fellings. How- ever, where the thinning of young stands is concerned, development has been comparatively slow and a major part of the thinning work is still carried out manually. Following are the reasons therefor.

The young stands are very sensitive to repeated pressure loads on the superficial and delicate root systems which are characteristic of dense young stands. Pressure damage to the root systems often gives rise not only to rot in the lower part of the stem but also to a slower growth of the tree for a long time after the damage arose. With mechanized thinning, comparative¬ ly wide strip roads have to be opened up in the stand so that transport vehicles and thinning machines, if any, can enter the work area. In practice, these strip roads are made at least about 4 meters wide and largely run in parallel. It is essential that the strip roads be spaced as widely apart as possible since said roads because of their relatively large width collectively deprive the standing crop of a considerably production surface. It is thus desirable that the minimum distance between strip roads amounts to at least 30 meters, but when work is performed by means of long crane booms from the strip road the practical result will mostly be a considerably shorter distance between strip roads. For mechanized thinning of young stands use is nowadays made of two different types of machines or systems, viz. those traveling on the strip roads and those traveling through the stands. These two types are adapted to exhaust a suitable number of trees from the stand in such a manner that there will remain in the

stand a number of trees which as far as possible have been correctly selected from a biological viewpoint and are spaced apart a distance biologically correspond¬ ing to the age and growth conditions of the stand. The exhausted felled trees shall preferably be assembled in appropriate stacks lying essentially at right angles to the strip road concerned and having the root ends of the stems facing the side of the strip road. At the strip road the trees are then cut up into suitable tree lengths with the aid of machines traveling on the strip road, either by preceding limbing, cross cutting and stacking, or only by cross cutting, loading and extrac¬ tion of the tree lengths including the remaining twigs which are later cut off at a suitable spot so that they can be made use of in a concentrated state as fuel.

At the exhaustion of an individual tree it is important that the machine or the equipment thereof does not bump against and scrape off the bark of the trees to be left behind. Damage of this type during some seasons nearly always results in stem rot which considerably reduces the value of the trees in the future. In machines tra¬ veling on the strip roads and having long crane booms, it usually is the crane boom that causes this impact damage. The reason is that the crane boom is difficult to operate owing to its length and weight, especially in narrow openings between trees, but also because twigs of trees left behind - at greater distances - greatly reduce the driver's field of vision and, as a conse¬ quence, his possibility to avoid causing impact damage. Thinning machines which travel through the stands, in principle operate in. such a way that they leave the strip road and enter the stand between the trees, where they are driven up to each, individual tree to be ex¬ hausted. The machine saws or shears the tree from the stump, stores the tree in standing position and then moves on to the next tree to be exhausted. Having cut

and assembled a small bundle of exhausted trees in this manner, the machine reverses to the strip road and de¬ posits the bundle with the root ends at the side of the strip road. In practice, the prior art. thinning machines have so low a capacity that each bundle con¬ tains only two to five trees. Thus there is a great risk of impact damage in that the machine carrying a bundle of vertical trees will have poor stability, par¬ ticularly when traveling over natural obstacles or rough ground, and therefore - despite the driver's carefulness - will bump in an uncontrolled manner against and damage the trees left behind. Moreover, in a young stand the prior art thinning machines traveling through the stand will leave marked indentations in the ground, as the machines with the tree bundle thereon generally reverse towards the strip road on the same track that they pro¬ duced on entering the stand from the strip road. If, furthermore, the distance between strip roads shall be as great as is desirable and the stand has a high stem density, the machine will have to be driven re¬ peatedly on the same track and certainly most intensely in the immediate vicinity of the strip roads, where the number of machine runs will seriously damage the superficial root systems of the trees to be left be- hind. Considering that the prior art thinning machines traveling through the stands have to store each tree and carry the stored trees in bundles, the machines must always be driven quite close to each tree to be exhausted, which results in that these machines will not leave any great ground surfaces unscarred by traf¬ fic. This thinning method in which the trees are trans¬ ported in vertical position from the cutting area to the strip road, calls for an extraordinarily good sta¬ bility of the machine and this stability must be based on the product of relatively great weight and large width, properties which both should preferably be at a minimum in order not to cause damage to the trees and the ground.

Summary

This invention aims at creating the prerequisite conditions for rational thinning of young stands by combining the advantages inherent in, respectively, the above-mentioned thinning machines traveling on the strip roads and those traveling through the stands, and by simultaneously substantially eliminating the drawbacks from which said machines suffer. In parti¬ cular, the invention aims at making it possible to use strip road distances far in excess of the thirty meters that are considered conventional at the same time as a biologically optimum thinning is realized without any risk of injurious damage to the ground and to the trees to be left behind. For this purpose, the invention relates to a thinning machine of the kind which in a manner known per se com¬ prises a wheel-mounted chassis and a feller assembly for a crane which in addition at least to a boom carry¬ ing the feller assembly presents a mount arranged on the thinning machine, said machine being characterised by the combination that the crane mount and the ^' driver's cabin are disposed on a common platform which is rotat- able about an axis contained in a plane of symmetry extending through the machine, that there is provided in conjunction with the crane mount and the driver's cabin a free space which is adapted, when the occasion arises, to accommodate the feller assembly and a stem grasped thereby, and that both the driver's cabin, the crane mount and said space are located within an imagi- nary circle whose diameter is substantially at most equally large as the largest width of the machine, where¬ by the driver's cabin, the crane mount and the feller assembly as well as said stem will be contained within the space of the ground area occupied by the machine independently of the swing angle position of the plat¬ form.

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Further illustration of. the prior art

Some machines which are adapted for final felling of forest operate in such a way that a crane-mounted feller assembly after the cutting of an individual tree is moved inwardly some distance towards the crane mount, whereupon the crane and the feller assembly are swung to a position in the region of the rear portion of the machine where the tree is deposited. In this case, how¬ ever, the diameter of the circle described by the feller assembly when swung to the rear portion of the machine, is considerably greater than the largest width of the machine, which implies that the machine concerned cannot possibly be used within a dense young stand without the feller assembly during its swinging movement bumping against or scything the trees left behind around the machine. For their function, said prior ^* art machines thus require a very large free space around the machine. Brief description of the drawings In the drawings, Fig. 1 is a perspective view of the thinning machine according to the invention, ^" shown immediately after the cutting of a tree.

Fig. 2 is a perspective view of the same machine in conjunction with the deposition of the cut tree, Fig. 3 is a slightly enlarged perspective view illustrating certain details of the machine, parts of the machine having been cut away for this purpose;

Fig. 4 is a side view of the machine showing the function thereof;

Fig. 5 is a top plan view of the machine shown in Fig ₀ 4;

Fig. 6 is a top plan, view of a machine in an alter¬ native preferred embodiment;

Fig. 7 is a longitudinal section on the line VII-VII in Fig. 6;

Fig. 8 is a cross-section on the line VIII-VIII in Fig. 7;

Fig. 9 is an enlarged partial perspective view of the embodiment shown in Figs. 6-8; Fig. 10 is a simplified top plan view of a stand which is being thinned according to a first system with the aid of the machine according to the invention; and

Fig. 11 is a similar top plan view illustrating another alternative thinning system. Detailed description of the preferred embodiments of the invention

The thinning machine 1 according to the invention (see Figs. 1-5) comprises as main components a wheel- mounted chassis generally designated 2, a driver ^r s cabin 3, a crane generally designated 4, and a tree assembling device which in this instance is a conventional clam bunk 5. At the free end of an outer boom 6 of the crane 4 there is arranged a feller assembly 7 which in a man¬ ner known per se can grip an individual tree 8, and cut it, e.g. by sawing or shearing. The assembly 7 may in practice also be provided with means for limbing and cross-cutting of the felled tree. The feller assembly 7 can be swung in its entirety to various angular_po¬ sitions relative to outer boom 6 with the aid of a cy- under and piston mechanism or hydraulic cylinder 9. The outer boom 6 is in turn supported by a parallel section or parallel motion system consisting of two in¬ dividual upper and lower boom sections 10 and 11, respec¬ tively which at one end are pivotally connected to the boom 6 via joints 12, 13 and at the other end pivotally connected to a crane mount 14 via joints 15, 16. A slant¬ ing hydraulic cylinder 17 is adapted to swing the upper section 10 and thus the parallel motion system in its entirety and is connected to the upper section 10 at some distance from the joint 15. When the parallel mo- - tion system 10, 11 is swung in the vertical plane with the aid the cylinder 17 the feller assembly 7 will be

carried along in a manner known per se and occupy one and the same, substantially vertical, angular position during the major part of the swinging movement. To allow extension of the feller assembly to a position extremely remote .from the crane mount 14 the lower section 11 is, however, extendable, more particularly in that it includes a hydraulic cylinder the piston 18 of which can whenever necessary be extended so that the boom 6 can be swung outwards relative to the section 10 to a position in which the boom 6 and the section 10 make a large angle with one another (see Fig. 4) .

According to a feature characteristic to the inven¬ tion, the crane mount 14 and the driver's cabin 3 are dis¬ posed on a common platform 19 with the crane mount 14 placed in immediate vicinity of the driver's cabin 3 so that the crane 4 when swung will move in a vertical plane located in parallel with and immediately adjacent one of the two side walls of the driver's cabin. The platform 19 is rotatable about a center or an axis contained in a plane of symmetry extending through the machine. This swinging movement can be realized by means of a reversibly movable turntable 20 (see Fig. 3) driven by rotary force and the lower portion 20' of which is fixedly anchored to the chassis, while the upper rotary portion 20" is fixed- ly connected to the underside of the platform 19.

The chassis 2 is divided in a manner known per se into two halves or parts, viz. a first or front chas¬ sis part 21 (see Fig. 3) which is supported by a wheel pair 22, 22* and a second rear chassis part 23 which is likewise supported by a wheel pair 24, 24'. The two chassis parts 21, 23 are interconnected via an articula¬ tion generally designated 25, which includes a substan¬ tially vertical pivot 26 allowing the two chassis parts to swing relative to one another in the horizontal plane (during adjustment or alteration of the angle between said two wheel pairs) and a shaft 27 which in the present instance is tubular and rotatably mounted in the rear

chassis part 23, parmitting rotation or restricted swing¬ ing of the chassis parts relative to one another in a vertical plane extending longitudinally of the vehicle. The angle through which the shaft 27 can rotate in rela- tion to the chassis part 23 can be restricted in va¬ rious ways, for example by means of a block-shaped stop means 28 disposed at the end of the shaft 27 remote from the articulation 25.

The wheels 22, 22' and 24, 24' are suitably indivi- dually driven with the aid of static displacement drives 29 in the wheel hubs. Between the two chassis parts 21 and 23 there may also advantageously be provided two hy¬ draulic cylinders (not shown) by means of which the front chassis part can be caused to swing relative to the rear chassis part with a view to steering the machine in the desired direction. Theoretically, however, such hydraulic cylinders can be dispensed with and steering may be pro¬ vided by controlling the movements of the drive wheels. The chassis part 23 is built up around a framework 30 which in turn supports an engine 31 which is adapted to drive a hydraulic pump 32 for driving the wheel hub drives 29, and a hydraulic pump 33 (see Fig. 4) for driving the other hydraulic systems of the machine. Hydraulic hoses 34 (Fig. 3) for supply of hydraulic medium to components in the front chassis part 21 can to advantage be passed through the tubular shaft 27.

A sturdy engine hood 35 is disposed over the engine 31 and can be swung upwards via joints 36 to the posi¬ tion shown in Fig. 3, in which the engine is uncovered. At the rear end of the engine hood there is arranged a likewise sturdy racket 37 on the free end of which the clam bunk 5 is pivotally mounted. The clam bunk 5 comprises in a manner known per se two gripping arms 5', 5" which are movable between the closed position shown in Fig. 3 and an open position with the aid of a hydraulic cylinder 38.

A fuel tank 39 for the engine 31 as well as a hy-

draulic medium tank 40 for the hydraulic systems of the machine are arranged on the framework 30, more exactly on the outer side of the. two beams forming the framework. Underneath a second hood 41 placed on the front chassis part 21. there are arranged various components required for the operation of the machine, such as elec¬ tronics components and hydraulics components. This hood 41 is relatively small and has an upper side which is slanted such that the driver will have an unobstructed view through the windshield 42 of the cabin 3 also in the region immediately ahead of the machine.

It will appear from Figs. 1 and 5 in combination that the driver's cabin 3 is eccentrically located in relation to both the platform 19 and the center of rota- tion thereof. In the region ahead of the crane mount or bracket 14 there is a free space 43 which can accom¬ modate the feller assembly 7 and the stem of the tree 8 cut by said assembly such that the tree will be locat¬ ed immediately adjacent the cabin, more particularly close to one, front corner 44 of the cabin. According to an essential feature of the invention, both the dri¬ ver's cabin 3, the crane mount 14 and said space 43 are contained within an imaginary circle the diameter of which is substantially equally large as or possibly less than the largest width of the vehicle, which in this in¬ stance is determined by the distance between the outer sides of the wheels 22, 22' or 24, 24'. Regardless of the angular position taken by the platform 19, the driver's cabin 3, the crane mount 14 and the stem grasped by the feller assembly 7 will be contained within the space of the ground area occupied by the machine. A tree cut by the feller assembly and taken into the space 43 by swinging of the boom 6 and sections 10, 11 will not even come in contact with the trees left behind which are located close to the machine when the tree by rota¬ tion of the platform 19 is moved to the rear position in which it can be deposited in the clam bunk 5.

Function of the thinning machine according to the in¬ vention

At the felling of an individual tree 8 with the machine placed in the stand concerned, the procedure is as follows: Having decided which tree to fell, the driver in the cabin 3 rotates the platform 19 to such a position that the crane 4 can be swung up to the se¬ lected tree without bumping against the surrounding trees. Swinging of the crane is performed with the aid of the hydraulic cylinder 17 and, if necessary, with the aid of the hydraulic cylinder 18 in case the fel¬ ler assembly 7 shall be extended an extremely far di¬ stance from the crane mount, say to the position A shown in Fig. 4. After the assembly 7 has gripped and shorn the tree while leaving the stump 45, the feller assembly is moved back to the space 43 in the vertical plane in which the crane is movable, and with the stem al¬ ways vertically oriented so that it can pass unobstruct- edly between the remaining trees in the stand. Once the tree has been moved into the region of the front corner 44 of the driver's cabin 3 (position C in Fig. 4) in which the boom section 10 is substantially vertically oriented like the stem, the platform 19 is caused to rotate about its center 46 to the swing angle position in which the driver's cabin faces rearwardly and the feller assembly 7 is located between the crane mount 14 and the clam bunk 5. Then the feller assembly is lifted to position D in Fig. 4, whereupon the assembly is swung with the aid of the hydraulic cylinder 9 re- lative to the boom 6 to the recumbent position E in which the assembly releases the stem so that it can be caught by the clam bunk 5 (cf. also Fig. 2) . After that the feller assembly 7 is returned to position C and the platform 19 is rotated to the desired position in which the driver selects a new tree and repeats the procedure described.

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When all trees which have been selected for exhaus¬ tion by thinning and which can be reached with the feller assembly from the location in question, have been exhaus¬ ted and placed in the clam bunk 5 the gripping arms 5', 5" are closed. Then the thinning machine is moved to the next location with the tree bundle assembled in the clam bunk trailing after the machine. In practice, the machine is hereby moved about one crane boom length, whereupon the thinning work is continued in the manner described above.

Brief description of an alternative embodiment of the thinning machine according to the invention

Reference is now made to Figs. 6-9 which illustrate an alternative embodiment in which the machine is provid- ed with an arrangement for leveling or tilt compensation of the driver's cabin. In this instance, the platform 19' which supports the cabin 3 and the crane mount 14 via a turntable or like means is rotatable about another platform or support 47 which in turn is laterally tilt- able relative to the associated chassis part, more par¬ ticularly the rear chassis part 23. According to the invention, the platform or support 47 is mechanically connected to the front chassis part 21 to tilt or swing in dependence on the occurring swinging movements of said chassis part in relation to the chassis part 23, more precisely with a tilt angle relative to the chassis part 23 less than the swing angle difference between the two chassis parts. This mechanical connection is realized by means of a transmission which in the embodi- ment illustrated engages a first swing arm 48 rigidly associated with the pivot 27' and making an angle there¬ with, and by means of a second swing arm or bracket 49 rigidly connected to the support 47 and being of a greater length than the swing arm 48. The two swing arms 48, 49 are interconnected by a pivot pin 50 which is fixedly arranged on the arm 48 and engages in an elongated hole 51 at the lower end of the swing arm 49.

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The. support or platform 47 is provided at the under¬ side with two anchorage pins 52, 25' which are rotatably mounted in bearings 53, 53* which in turn are secured on the upper side of the framework 30 to the chassis part 23. The distance from center to center between the pivot 27* and the pivot pin 50 is preferably about half as large as the center distance between the pivot pin 50 and the tilt axis which is formed by the anchorage pins 52, 52' and extends longitudinally of the vehicle. This relation (1:2) between said center distances gives a swing angle deflection α of the support 47 if it is assumed that the current swing angle deflection between the two chassis parts 21 and 23 amounts to 2α. If the rear chassis part thus swings in relation to the front chassis part because of uneven or rough ground the dri¬ ver's cabin 3 will not swing or tilt by the same angular deflection as the chassis part proper, but only by an angular deflection which is half as large as the swing angle difference between the two chassis parts. Con- versely, it is realized by the mechanical connection between the chassis part 21 and the support 47 that the machine also during driving will have a continuous four- point stability at angles of roll and overturning moments despite the existence of the articulation 25 and its function. Without said connection the machine, like conventional articulated cross-country machines, would present only three-point stability (the triangle formed by the two ground contact points of the rear wheels in combination with a point at the center of the forward extension of the vehicle at the steering articulation) . It is of course conceivable to modify the embodiment il¬ lustrated in Figs. 6-9 in various ways, for instance with the use of other types of mechanical transmissions for producing the angular transmission ratio with respect to the support 47. Instead of the swing arms shown, use can thus be made of gearings, roller chain gearings or other lever transmission systems. It is also conceivable

to make use of other gear ratios than precisely 1:2, for instance by changing the distance between the pivot pin 50 and. the pivot 27' and the distance between the pivot pin 50 and the tilt axis 52, 52', respectively. An essential advantage of the described arrangement is that each swing angle difference between the two chas¬ sis parts 21 and 23 is immediately transferred mechanical¬ ly to the support 47 and the driver's cabin supported thereby, which implies that the tilting tendency of said cabin will be damped at each single moment during the pro¬ pulsion of the machine. This effect further is of essen¬ tial importance to providing good comfort for the driver. Detailed description of the practical use of the machine A first way of utilizing the thinning machine de- scribed in the foregoing is illustrated in Fig. 10. The machine 1 commences the thinning operation, starting in lane Kl from the strip road SI with the clam bunk 5 of the machine facing rearwardly as seen in the direction of propulsion. (The terms "front" ^' and "rear" chassis parts, respectively, have been used above setting out from the assumed direction of propulsion during the thinning- work in the stand. When, however, the machine is propelled on roads for transport over long distances the direction of propulsion may be the opposite one, i.e. with the wheel pair 24, 24' leading ahead of the wheel pair 22, 22'.) With the aid of the feller assembly 7 the thinning machine opens up its lane area by felling at least so many trees that the machine is accommodated in the stand. This felling of the individual trees is per- formed in the manner earlier described. At the first lo¬ cation there are felled not only the trees necessary in order that the machine shall be accommodated in the stand but also all other trees to be exhausted by thinning and which the feller assembly can reach from the location in question. When this has been done, the clam bunk 5 is closed and the machine moved by about one crane boom length to the next location where the procedure is re¬ peated.

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When the thinning machine has concluded the work up to the strip road S2 the clam bunk or its arms 5', 5" are opened and the tree bundle carried along slides off the clam bunk and is left lying with the root ends laterally of the strip road S2 during the continued propulsion of the machine. Then the machine continues, thinning the stand along lane Kl between the strip roads S2 and S3. When the strip road S3 is reached, the machine deposits the further tree bundle T2 formed and using the strip road S3 the machine turns through 180° in a right-hand curve entering lane 2. The thinning machine then proceeds to work systematically along lanes K2, K3, K4.

At the end of lane K4 it is illustrated how the machine 1 operates with the non-thinned stand 55 in front of it. The crane 4 is swung towards the right- hand lane side and with a maximum boom length the crane cuts with the feller assembly 7 a tree 8 at the border between lanes K3 and K4. The system is not restricted to working over three strip roads only, as has been exemplified in the draw¬ ing, but can of course be extended over a great many strip roads or, alternatively, restricted to working between two adjacent strip roads only. Fig. 11 illustrates an alternative system or pro¬ cedure which permits the use of extremely great strip road distances. In this case the thinning machie enters the stand from the strip road SI along lane Kl and cuts only the trees standing in the lane proper, loading them onto the clam bunk 5. At the strip road S2 the assembled tree bundle Tl is unloaded, whereupon the thinning machine turns through 180° on the strip road S2 and enters lane K2 where the same work as in lane Kl is repeated. Back at the strip road SI the tree bundle 2 is unloaded, whereupon similar work opera¬ tions are repeated along lanes K3 and K4, where the tree bundles T3 and T4 are unloaded at the strip roads

S2 and SI, respectively. Then the thinning work proper begins. The thinning machine now enters the lanes opened up, but' in the opposite direction of propulsion along the lanes and performs thinning work like the one ear- lier described. Tree bundles T5, T6, T7 and T8 are again formed and alternately unloaded at the strip roads SI and S2 so that these bundles will lie at the opposite end of the lanes as compared with the initially depo¬ sited tree bundles (Tl, T2, T3, T4) . Instead of first systematically opening up all lanes and then doing the thinning work,- the opening up of lanes and the thinning work can take place al¬ ternately in various forms. Thus one can open up for instance lanes Kl, K2 and K3 as earlier described, whereupon the thinning machine via the strip road S2 enters lane Kl where the thinning work is performed towards the strip road SI where the tree bundle T5 is unloaded and the thinning work immediately continues along lanes Kl and K3 towards the strip roads S2 and SI, respectively. After that, the opening up of lanes begins again.

If during the thinning work the clam bunk 5 is filled before the arrival of the machine at the strip road because of wrong planning, the machine is propelled to the strip road and unloaded there in order to be immediately reversed to the place where the thinning work was interrupted and to continue thinning up to the strip road in question. At the end of lane K2 it is illustrated how the thinning machine 1 operates along the opened-up lane with a non-thinned stand in front of it. A tree 8' in the border region between lanes K3 and K4 has just been positioned for thinning.

Also with the method illustrated in Fig. 11, the thinning machine can be propelled as with the use of the method illustrated in Fig. 10, along lanes cross¬ ing two or more strip roads.

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Advantages of the invention

Using the machine according to the invention, one can work with a strip road distance far exceeding the conventional strip road distances and attain an essen- tially increased production surface in the stands thinned. As the machine travels over the ground sections in ques¬ tion but once or at most two times the risk of damage being caused to the ground and the root systems of the trees is minimized. Moreover, the characteristic mode of operation of the machine, i.e. to move the stem in a vertical position to a point close to the center of the machine and to swing the stem inside an area smaller than the width of the vehicle, ensures that damage to the stems and twig systems of the trees left behind is avoided. Besides, the work can be performed rapidly and rationally. Conceivable modifications of the invention

It will be realized that the invention is not re¬ stricted to the embodiments described above and illu- strated in the drawings. Thus, it is possible for in¬ stance to use the machine according to the invention not only in conjunction with the thinning procedure according to the invention but also in conjunction with other methods of felling trees. It should also be ob- served that the cabin leveling arrangement illustrated in Figs. 6-9 can be applied in conjunction with other machines or vehicles than precisely thinning machines. The mechanical connection between the support 47 and the chassis part in question may be realized in another manner than by means of an elongated tubular shaft 27 which is rigidly connected to a transmission spaced a great distance from the articulation. Thus the steer¬ ing articulation - with a view to permitting a high location of the transmission in relation to the cabin- carrying chassis part - can be associated with a device which transmits the rotary or swinging movements di¬ rectly to the support or to a transmission shaft of

a high location. The expression "pivot" employed in the foregoing should be interpreted as the geometrical pivot axis of the articulation.

It should finally be mentioned that the machine described can be given, very small dimensions as compared with conventional forestry machines. Thus, the total width of the machine, i.e. the width between the outer sides of the wheels, may be as small as 2.0 meters, while its total length is 5 to 6 meters. Besides of operating in straight lanes between and across the strip roads the machine may of course also operate along other lane systems between the strip roads just as well as the thinning work may be carried out from the strip roads in the conventional manner It should also be emphasized that the feller assem¬ bly may be substituted for other implements or tools in¬ tended for treating or handling other objects than tree stems. In other words the machine may be modified to be a working machine in general. By providing the crane boom with suitable adapters it is accordingly possible to use the machine for felling and laying trees in small- dimension final fellings; for mechanized cleaning; for soil scarification; for line work such as pole trans¬ portation, hole making and pole erection; for handling various goods and for special operations such as service operations in connection with street lighting, buildings etc.

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