DE9101010U1 - Excavator - Google Patents

Description

Description:

The innovation relates to an excavator, preferably for forestry, in which a height-pivoting boom is mounted on a track-chain chassis and is movable on both sides by at least 90° to the direction of travel, is provided with a pendulum arm at the free end and with an interchangeable working device at the end of the pendulum arm, with hydraulic working elements being provided for operating the boom, pendulum arm and working device.

The most commonly used tool for well-known excavators of the type mentioned above is the backhoe. Excavators with excavator shovels or backhoes can be used in a variety of ways in forestry work. They can be used for all earthworks, but also for picking up and placing trees, trunks, root stocks, etc. in an orderly manner, as well as for clearing or removing root pieces, as well as for work that occurs when felling or felling timber, but also when it is necessary due to bad weather as a result of snow or wind damage, in order to recover the usable wood and clear the ground for reforestation.

In such forestry work, the use of excavators has the very significant advantage that they exert the least ground pressure compared to all other mobile work machines with a crawler chassis. Another advantage is the greater boom reach and mobility compared to other mobile work machines. Low ground pressure means a reduction in harmful soil compaction; large boom reach and mobility allow

to carry out work in a relatively large area without having to maneuver the chassis. Little maneuvering protects the valuable but sensitive humus layer of the forest floor.

Other tools than the excavator bucket or the backhoe, which can be used for forestry work with excavators with the same advantages as the latter, are mulchers and crab grabs.

Like other mobile machines with G-track chassis used in forestry, excavators also have the disadvantage that they are not approved for use on public roads. They must be transported from site to site using low-loaders.

However, the well-known excavator of the type mentioned at the beginning cannot be used for brushwood work in forestry with any of its tools.

From the point of view of maintaining the biologically good condition of the forest floor and preserving its undamaged humus cover, which is particularly important for reforestation, it is best to carry out brushwood work by hand. During this work, twigs, branches, etc. that are naturally scattered across the forest floor as a result of wind damage or other weather damage, as a result of damaged or diseased trees, or as a result of forestry maintenance or cultivation measures, are picked up and placed in mounds for the purpose of rotting or composting.

This "manual" brushwood work is unpopular with the forestry workforce, not least because

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because it involves constantly having to bend over. The wage costs are not justifiable these days. In addition, the huge areas of brushwood, which currently need to be cleared quickly due to storm damage and forest dieback, could never be managed with human labor.

When it comes to clearing logging waste, which is currently the most common as a result of forest dieback and climate damage, the use of machines is indispensable, not least because of the need to remove not only brushwood but also heavy, thick logs, etc.

It is known to equip agricultural tractors with brushwood forks and to use them.

Forestry cutters are equipped with clearing rakes.

Both types of tractor can only be used to a limited extent or not at all for handling heavy logging waste, so that additional use of other machines, such as a forwarder with a long crane or an excavator of the type mentioned above with excavator bucket I as a working device, is necessary.

Tractors cause high compaction of the forest floor due to the high surface pressure exerted by their chassis. Their chassis profiles damage the humus cover. The additional use of other machines increases soil compaction and damage to the humus cover.

Crawler tractors equipped with a dozer blade or brush rake are also used on a large scale. The crawler tractors

lead to very high soil compaction - due to their high weight - and they cause considerable damage to the humus layer through their caterpillars.

They can move heavy logging waste, so that the use of additional machines can at least be greatly limited, if not completely avoided.

Brushwood work with a crawler tractor, regardless of whether it is equipped with a dozer blade or a brushwood rake, also has disadvantages.

The description of these disadvantages must begin with the way in which bulldozers usually work and which is the only way possible. On these machines, the respective implement, bulldozer blade, digging rake or brushwood rake, is attached to the front end of the chassis and can be extended and retracted forwards and approximately 2.50 m in a longitudinal horizontal direction by means of guides fixed to the chassis and by means of hydraulic cylinders acting on a pair of knee joint levers.

This means that the crawler can only push brushwood in front of it with its brushwood rake while driving forwards or pushing it forwards by about 2.50 m while stationary. It has to drive and maneuver a lot to push the brushwood together.

Your brushwood rake has closely spaced teeth that, depending on the design, are set at between 60° and 90° to the ground surface. A brushwood rake cannot be tilted or inclined. The angle of attack is unchangeable. The interaction of both spatial features means that

the brushwood is peeled off the forest floor with more or less humus cover. It is impossible to comb or comb out the brushwood without damaging the humus cover. In this way, a lot of humus is pushed into the brushwood mounds.

Because caterpillars can only push, brushwood embankments are created, the cross-sectional profile of which has disadvantages. For optimal decomposition and humus formation, brushwood embankments should be a certain height. Caterpillars cannot achieve such a height, but push together very wide and rather flat brushwood embankments of around 6 to 7 m wide. As a result of the excessively large surface area of the brushwood embankments, part of the forestry land is lost.

Caterpillars and their tools are naturally heavy and solid because of their original purpose for civil engineering, where they have to exert extremely high thrust forces. They therefore generate high surface pressure and compact the forest floor. This has a particularly detrimental effect on the forest floor due to the frequent maneuvering. Because the caterpillar pushes the brushwood in front of it and also takes part of the humus layer with it, the undercarriage has a direct effect on the damaged humus layer. This completely destroys the humus layer and the compaction effect is particularly high.

Forest work causes wear and tear on the cutting edges or teeth of the tools, and often also damage, e.g. when they come into contact with stones. Repairs on site are impossible due to the solid construction and can only be carried out after dismantling.

of the respective work equipment. This work cannot be carried out without aids such as lifting equipment, etc., because the work equipment is extremely heavy due to its solid construction. This is why such repairs are time-consuming and expensive.

In summary, it can be stated that the brushwood work and in particular the removal of logging waste, which currently has to be done on a large scale, cannot be managed with the current means or can only be managed unsatisfactorily, with the risk of sometimes quite serious damage to the forest floor and especially to its sensitive humus layer.

The innovation is therefore based on the task of finding a solution to this problem by creating a spatial form for an excavator of the type mentioned at the beginning, which is known due to its properties as the most gentle working machine for forest soil and humus cover, which makes it usable for economical brushwood work and in particular for economical removal of logging waste.

To solve this problem, the excavator mentioned at the beginning is characterized by the fact that a (brushwood) clearing rake and a counter-grabber are hinged to the pendulum arm as working equipment, that the clearing rake and counter-grabber can be pivoted independently of one another and moved in a pincer-like manner towards one another by means of hydraulic working elements hinged to the pendulum arm, and that the clearing rake and counter-grabber are curved in an arc shape with concave sides facing one another in the vertical direction, have wide teeth and are designed in a lightweight vertical frame construction, with the clearing rake being wide and high.

The excavator, which has been designed in accordance with the new technology, can be used in forestry, primarily for brushwood work and the removal of felled material, but also for other
Forestry work, with great advantages.

A great advantage is that the clearing rake has an operating radius of approx. 18 m simply by moving the boom, i.e. when the chassis is stationary.
Maneuvering that compacts the soil or even damages the humus layer is therefore eliminated.
Of inventive importance is that the excavator with its undercarriage can be used for brushwood work or
The removal of slash and burn waste proceeds on the brushwood cover and clears the latter, so to speak, "behind" and to the left and right of it.

The already lowest surface pressure of the
Excavator chassis is due to this inventive
Working method additionally from the brushwood or
The overburden is collected and spread over a large area like a mat on the underlying
humus layer of the forest floor.

The surface pressure experienced by the forest floor is
This makes it considerably lower than in the
This would be a cheap excavator without this measure.

Cheaper than the excavator is in terms of
Forest soil compaction is now only manual work, and in the latter case, however, when removing logging debris
Ultimately, additional machine power is still needed to recover and remove large and heavy items, which then leads to more or less severe soil compaction and damage to the humus layer.

It can therefore be assumed that the excavator, used in an inventive manner in accordance with the innovation, is almost as good as manual work in terms of protecting the forest floor.

The excavator, which has been designed in accordance with the new design, has a hydraulically pivoting, wide-toothed (brushwood) clearing rake at the end of its swing arm, which is curved in the shape of a curved tooth.

Apart from the fact that this clearing rake can be moved over the forest floor by the boom in the large radius already mentioned, the great mobility is a great advantage. The clearing rake can be raised by means of the boom when passing over raised areas of the ground and lowered into depressions, i.e. the surface contour can be carefully followed. This means that humus cover is never stripped away and no brushwood nests are left in depressions.

The swivelling ability and wide tooth design of the clearing rake allows its operation to be adapted to the respective requirements to a very large extent.

This means that the brushwood layer can be lifted from the ground surface if the clearing rake is set flat enough. The clearing rake can also be set to a continuously steep or blunt angle relative to the forest floor surface, i.e. it can be swivelled hydraulically, depending on which angle produces the best result.

Because the rake has wide teeth, it acts on the brushwood in a similar way to a fork, i.e. it only takes the

relatively long or long-fibered brushwood. Leaves tufts of grass, small herbs, etc. undisturbed and "combs" the brushwood from the forest floor surface without damaging the humus layer to any significant extent or more than is desired.

The deliberate, light scratching of the humus layer is desirable in order to facilitate the planting of young seedlings during reforestation, because it makes this work easier.

According to the innovation, the excavator can therefore pick up brushwood in a large area while standing, i.e. without driving or maneuvering, and can do so without taking humus with it or significantly damaging the humus layer, but on the other hand also with deliberate scratching or loosening of the surface of the humus layer.

In addition to the clearing rake, the excavator with the new design has a hydraulically operated, swiveling counter-grab. The clearing rake and counter-grab can be opened and closed like a pair of tongs.

With this design it is possible to pick up raked brushwood at any point in the boom's working area, press it together and place it on the brushwood wall from above by swiveling the support.

Almost all known machines have to push a rake filled with brushwood or its equivalent with the brushwood over the forest floor and thus disadvantageously over the humus cover to the brushwood wall.

According to the innovation, brushwood portions are raked together at any suitable location to fill the clearing rake, then collected, compacted and brought to the brushwood wall without any contact with the ground.

With this new way of building brushwood embankments, they can be made narrower in base and higher in height than was previously possible. The advantage is that the volume of the brushwood embankment is smaller than previously imaginable; if the brushwood is compacted vigorously before it is laid down, the volume of the brushwood is reduced and bulky wood is also broken or shredded. Compacted brushwood with shredded coarse parts composts much faster and more optimally and retains the necessary composting moisture, in contrast to the loose and easily drying brushwood embankments that are known to be formed, in which the composting process is interrupted for a longer period of time each time it dries out.

When it comes to clearing logging waste, the excavator has proven itself to be an unrivalled universal machine thanks to the innovation. Because the clearing rake and counter-grabber, including their opposing concave sides of the curved tooth curvature, form a kind of large pliers or grapple, tree trunks, long timber, etc. can be picked up and placed in an orderly manner, e.g. stacked or loaded onto vehicles for transport - naturally within the permissible load capacity of the respective excavator. As far as the load capacity allows, roots can be cleared and deposited. Undergrowth, climbing plants, bushes can be cleared and removed.

This work can be carried out with minimal movement of the excavator due to the large operating radius of the boom.

Because the excavator is also operating on the brushwood layer, only a very small amount of soil compaction is to be expected despite this deep, heavy work, and the damage to the humus layer is kept within the limits that are unavoidable anyway due to clearing measures.

If earthworks are to be carried out, such as filling holes left by cleared tree roots, the counter grapple is swung back so far that it almost touches the pendulum arm and does not interfere with work. The clearing rake is then used, like a dozer blade, to push earth into the holes.

When removing logging debris, machines other than excavators are only required in rare exceptional cases when the force required to clear roots or the weight of tree trunks to be lifted exceeds the load limits of the excavator.

Because the clearing rake and counter grapple are designed in a lightweight frame construction, only a small amount of load capacity is lost for the work mentioned. In addition, the already low ground pressure is further reduced.

Unless it is a matter of carrying out typical earthworks, such as digging holes or trenches, etc., which require the use of the backhoe or the

Excavator bucketL, the excavator can now be used in a variety of ways outside of forestry following the innovation.

Because the clearing rake is wide and high, it can efficiently clear large areas of brushwood quickly.

The further development according to claim 2 discloses a three-dimensional form of the clearing rake, in which on the one hand weight is saved, and on the other hand the advantageous curved tooth structure 11 of the teeth is realized in conjunction with high strength, in particular with respect to working loads.

It is particularly advantageous that the lower edge close to the ground has almost extremely wide teeth, while the area above it is more closely meshed in comparison, so that brushwood can be picked up below in a way that protects the soil and does not leave any humus, while the area above it prevents brushwood from falling through due to its "narrow mesh".

The development according to claim 3 discloses a spatial shape which increases the rigidity of the clearing rake while saving weight.

The further development according to claim 4 serves approximately the same purpose, whereby the stiffening intermediate pieces with an arched groove at the bottom are very useful both for combing and for gripping.

The design according to claim 5 has the special advantage that each of the four teeth of the clearing rake,

which are subject to the greatest wear and tear and can be easily replaced on site if they become damaged.

With the further development according to claim 6, the working surface of the clearing rake is increased considerably upwards - on both sides of the connection with the pendulum arm and the piston rod of the hydraulic cylinder. This allows very large amounts of brushwood to be raked together before the latter falls over the top of the clearing rake. Likewise, large amounts of brushwood can be held at once with the counter-gripper and placed on the brushwood wall. The working speed and profitability are thus further improved.

The further development according to claim 7 concerns the design of the counter-gripper and its connection to the pendulum arm. To swivel the counter-gripper, the pendulum arm must be equipped with an additional double-acting hydraulic cylinder, which is not normally present on the excavator. The necessary operating elements must also be attached to the driver's cab. However, this does not cause any difficulties, because the hydraulic system of an excavator has the necessary reserve capacity.

The selected geometry, the articulation point of the counter-gripper, the point of attack of the piston rod of the hydraulic cylinder, leads to high effective counter-gripper forces, but also allows the counter-gripper to be swung back into a rest position so far that, pointing upwards, it almost rests on the pendulum arm, so that it never interferes with other work, such as clearing.

The further development according to claim 8 characterizes a weight-saving, but highly resilient design of the counter-gripper in height I frame construction.

The embodiment according to claims 9 and 10 relates to the advantageous reinforcement and stiffening of the teeth of the counter-gripper.

The embodiment according to claim 11 stiffens the counter-gripper and improves its operation.

The further development according to claim 12 ensures that the clearing rake and counter-grabber can be assembled or disassembled within a short time, approximately within 15-20 minutes, whereby the lightweight construction of both contributes to this.

The design according to claim 13 makes it possible to create a scissor effect, with the help of which long wood can be easily broken.

The design according to claim 14 reveals a tried and tested dimensioning of the clearing rake, which enables the most efficient work. The large opening width between the clearing rake and the counter-grabber is very advantageous for picking up large amounts of raked brushwood.

The design according to claim 15 is very significant; because if the clearing rake and counter-grip together weigh a maximum of 1,000 kg, then that is considerably less than, for example, the dozer blade of a bulldozer, which also has even smaller dimensions.

This low weight combined with the high strength and large dimensions of the rake result in a very high level of effectiveness, because no more mass is moved and carried than is absolutely necessary, so that the power output and carrying capacity of the excavator are optimally used for the actual work. Of course, the low weight also means that the ground pressure remains low.

Thus, the excavator with the spatial form features of the innovation represents a previously unthinkable, fast-working, very sensitive and versatile forestry machine.

A preferred embodiment of the excavator according to the innovation is shown in the drawings. It shows:

Fig. 1 - a side view of the excavator according to the innovation,

Fig. 2 - a partial rear view of the clearing rake,

Fig. 3 - the clearing rake seen in the direction of arrow III in Fig. 2,

Fig. 4 - the clearing rake seen in the direction of arrow IV in Fig. 3,

Fig. 5 - the counter gripper in front view,

Fig. 6 - a sectional view of the counter gripper at

along the line VI-VI in Fig. 5,

Fig. 7 - a schematic side view of the pendulum boom end with attached clearing rake and counter grapple and

Fig. 8 - an exploded perspective view of a replaceable tooth with weld-on adapter.

Figure 1 shows an excavator 1 with a tracked chassis 2 and a driver's cab 3, which, together with a boom 4 on the chassis 2, can be rotated or swiveled by well over 180° around a vertical axis.

The tracked crawler chassis 2 has a large width and rests over a large length on a brushwood layer 5 with low surface pressure.

Beneath the brushwood layer 5 there is a layer of humus 6 and underneath that is forest soil 7.

The boom 4 can be swiveled hydraulically about the vertical axis mentioned above and can be raised and lowered by means of a hydraulic cylinder about a fixed joint on the driver's cab 3.

A pendulum arm 8 is articulated at the free end of the boom 4 and can be pivoted around the end of the boom 4 in the manner of a knee joint by means of a hydraulic cylinder.

On the side facing away from the chassis 2, the pendulum arm 8 has the usual hydraulic working element 9 - a double-acting hydraulic cylinder - used to operate the attached work device.

A brushwood clearing rake 10 is hinged to the free lower end of the pendulum arm 8 in the area of its upper end. At a laterally exposed point in its upper area, the clearing rake 10 is indirectly connected to the free end of a piston rod 13 of the hydraulic working element 9 via an intermediate link 11, which in turn is guided on the pendulum arm 8 by means of a guide link 12, and can thus be pivoted around the end of the pendulum arm 8.

As the figures, in particular Fig. 1, show particularly clearly, the clearing rake 10, the details of which will be described later, has a curved tooth shape whose concave side faces the chassis 2.

At a certain distance from its free end, a counter-gripper 14 is hinged with its upper end on the side of the pendulum arm 8 facing the chassis 2. The counter-gripper 14 also has a curved tooth shape in side view, the concave side of which faces the concave side of the clearing rake 10.

In contrast to the usual hydraulic working element 9 of the pendulum arm 8, an additional hydraulic working element 15 is hinged on the side facing the chassis 2. It is connected via hydraulic lines 16 and control elements in the driver's cab 3 to the hydraulic system of the excavator 1, which, as is known, always has a reserve capacity and also connection devices for additional hydraulic units.

The additional hydraulic working element 15 is designed as a double-acting hydraulic cylinder. Its piston rod 17 has a joint connection 18 with the counter gripper 14, which extends from the articulation point 19 of the

Counter-gripper 14 on the pendulum arm 8 is at least a quarter to a maximum of a third of the total length of the curved tooth shape.

This spatial shape is important because the small distance between the joint 18 and the articulation point 19 allows large pivoting movements of the counter-gripper 14 with relatively short working strokes of the additional hydraulic working element 15 and thus allows for rapid work. However, this distance must not be too small if the additional hydraulic working element 15 is to generate sufficiently large working forces of the counter-gripper, e.g. for breaking up coarse wood.

A third criterion for choosing the position of the joint connection 18 is that the counter-gripper 14 should be able to be swiveled back so far that it points upwards from the articulation point 19 with its curved tooth shape almost touching the pendulum arm 8, which is shown and indicated in this position by the curved tooth tip 20 in Figs. 1 and 7. In this position, the counter-gripper 14 is outside any working area of the pendulum arm 8 and the clearing rake 10, so that all work can be carried out without restriction.

When working with brushwood and also when removing logging debris, the excavator 1 travels on the brushwood layer 5 a certain distance corresponding to its reach in the direction of arrow "F" in Fig. 1 and then stops.

Then, with the chassis 2 stationary, only by corresponding operation of the boom 4 and by

Rotating the guide house 3, brushwood is raked together. The clearing rake 10 and the pendulum arm are swiveled, in particular in such a way that the most favorable angle of attack of the curved tooth shape of the clearing rake to the brushwood layer 5 is set in order to either lift the latter from the humus layer 6 and, without damaging it, or to comb it off or out.

In this way, the brushwood layer 5 is cleared step by step "behind" the excavator 1 and simultaneously to the left and right of it in a width corresponding to the boom reach. The latter is done by turning the driver's cab 3 with the boom to the left or right.

If the clearing rake 10 has raked together a worthwhile amount of brushwood, then the counter-gripper 14 is used. When activated, it carries out a clamp-closing movement towards the clearing rake 10. In the process, the brushwood is compressed or compacted to the desired extent. By actuating the boom 4, pendulum arm 8, etc. accordingly, the compacted brushwood portion is deposited to the left and/or right of the excavator 1 at the greatest possible distance in brushwood banks (not shown in Fig. 1).

With the described pincer movement of the clearing rake and counter-grabber 14, larger pieces of wood, etc. can be picked up and placed in an orderly manner during the clearance of felled material, and bushes, roots or the like can be grasped and cleared.

This method of working can also be used in many different ways outside of forestry.

In order to be able to carry out the described brushwood work quickly, effectively and with optimal utilization of the load and carrying capacity of the excavator 1, the clearing rake 10 is designed in a lightweight hollow frame construction with wide teeth and is wide and high.

This construction is shown in detail in Figures 2 to 4. A basic framework is formed by a pair of upper, horizontally running square tubes 21, 22 and a pair of lower, horizontally running square tubes 23, 24, which are connected in the middle of their length by a strong, vertically running stiffening tube 25 in a square design.

Four teeth 26 are welded onto the square tube pairs 21, 22 and 23, 24 at the front or working side at equal distances. Each tooth 26 consists of two curved tooth-shaped cut teeth - on the back, if necessary for the square tubes 21, 22 or 23, 24
notched flat steel bars 27, which are arranged at a distance from each other.

The flat steels 27 end at the top with the upper edge of the upper square tube 21. The lower pair of square tubes 23, 24 are located approximately halfway up or along the length of the arched shape of the teeth 26, so that a large overhang is formed downwards, which is very advantageous for picking up brushwood.

For additional stiffening, stiffening tubes 28 in square design are used between each two outer teeth 26, which are welded between the two pairs of square tubes 21, 22 and 23, 24.

In addition, a triangular brace angle 29 is welded between each flat steel 27 and each square tube 21, 22, 23, 24 forming a corner with it. Towards the bottom, between each two teeth 26, center teeth 30 are welded to the lower square tubes 23, 24.

Each central tooth 30 is short, wedge-shaped and slightly arched.

Between each central tooth 30 and an adjacent tooth 26 there is a flat intermediate piece made of flat steel which is welded to both of them and to the lower square tube 24 and which is approximately flush with the center line of the central teeth 30. The lower edge 32 of the intermediate pieces 31 runs in a concave arc shape in the downward direction and at a smaller distance from the lower square tube 24 than the tips of the central teeth 30.

A pair of connecting lugs 33 is welded to the upper pair of square tubes 21, 22 between the two middle teeth 26 and symmetrically to the center of the clearing rake, the distance between which corresponds to the width of the pendulum arm and which project over the front of the clearing rake 10, protruding upwards over the upper square tube 21, and accommodate bearing bushes 34. A connecting bolt 35, which also runs through the end of the pendulum arm, leads through these bearing bushes 34 and is designed to be easy to remove but secured against loosening or loss.

Another pair of connection bushes 36 with bearing bushes 37 arranged at a closer distance is

the back of the upper square tube pair 21, 22 and to the stronger, middle stiffening tube 25 in such a way that the bearing bushes 37 are offset upwards and backwards compared to the front of the clearing rake. A bolt 60, which is easily removable but secured against loss or accidental loosening, leads through these bearing bushes 37, on which the free end of the intermediate link 11 is mounted and transfers the actuating forces of the hydraulic working element 9 to the clearing rake.

To increase the working surface of the clearing rake 10 upwards, angles 38 pointing upwards, approximately aligned with the teeth 26, are welded to the upper square tube 21 in such a way that one leg is at a right angle and the other is aligned with the working surface. The legs 39 running at right angles to the working surface are tapered upwards in a wedge shape. Two angles 38 located on either side of the pairs of connecting lugs 33, 36 are connected at the upper end by a welded-in, circular tube 40. A welded-in intermediate flat steel 41 runs from the middle of the tube 40 to the upper square tube 21. Angles 38, tubes 40 and intermediate flat steel 41 form upward-pointing attachments 42 on both sides of the connection socket pairs 33, 36, which increase the working surface of the clearing rake upwards.

The teeth 26 have adapters 43 welded between and to the flat steels 27 at the lower end, onto which drop-forged hard steel teeth 45 are fitted in an exchangeable manner and secured by means of pins 44. (Fig. 8)

The clearing rake 10 has a width of 2.1 m, a height of 1.32 m, a distance of 0.55 m between its teeth 26 and a tooth width of 90 mm.

The counter gripper 14 consists of two curved tooth-shaped cut steel teeth 46, which are connected at the top at a distance of about a quarter and at the bottom at a distance of about a third of the total tooth length from the upper or lower end by means of a welded, horizontally connected square tube 47 or 48.

At the upper end of the flat steel teeth 46, bearing bushes 49 are attached for a bolt 50, which is releasably received in tabs 51 (Fig. 1) on the chassis-side surface of the pendulum arm 8, whereby suitable safeguards are provided against loss or accidental release and the articulation point 19 is formed.

Two flat steel bars 52 running parallel to each other, at a distance from each other, symmetrically to the vertical center plane of the counter-gripper 14 are welded between the two square tubes 47, 48. They accommodate a detachable, but captively held bolt 53, which serves to connect to the piston rod 17 of the additional hydraulic working element 15.

A reinforcing flat steel 54 is welded between each flat steel 52 and the adjacent flat steel tooth 46 in such a way that its surface is approximately flush with the radius of curvature of the concave arch shape.

The lower ends of the F salmon steel teeth 46 are reinforced by F salmon steel layers 55 welded on both sides.

A welded steel plate 56 extends from the lower square tube 48 from F LachstahL tooth 46 to F LachstahL tooth 46, which runs approximately in the middle of the F LachstahL teeth 46 and whose lower edge 57 is at a distance from the
F salmon steel tooth tips 20 concave curved.

At the height of the bolt 53, one flat steel tooth 46 has a small circular hole 58,59, the other a larger one. The bolt 53 can be driven out through these holes 58,59 when dismantling the counter gripper.

The width of the counter-gripper 14 is less than 0.55 m, so that it can be pivoted like a pair of scissors between the middle teeth 26 of the clearing rake 10. This makes it possible to shred coarse wood.

The clearing rake 10 and counter grapple 14 together weigh no more than 1,000 kg. Both can be dismantled from the pendulum arm within 15 to 20 minutes.

Thus, the excavator 1 with clearing rake 10 and counter grapple 14 is effective, with high capacity utilization for brushwood work, clearing felling debris and other work in forestry but also for other work areas and can be easily converted if required.

ALL individual and combination features presented in the description and/or drawings are considered essential to the invention.

The scope of protection of the innovation extends not only to the features of the individual claims, but also to their combination.

The innovation is not limited to the presented and

described embodiment. Rather

This is just an advantageous example of implementation.

Claims (15)

PATENT ATTORNEY ipl.-lng. P- HpH^!:^ 0 KOBLENZ Protection claims: 1. Excavator, preferably for forestry, in which a height-pivoting boom is mounted on a track-chain chassis and is movable on both sides by at least 90° to the direction of travel, is provided with a pendulum arm at the free end and with an interchangeable working device at the end of the pendulum arm, hydraulic working elements being provided for operating the boom, pendulum arm and working device, characterized in that that a (brushwood) clearing rake (10) and a counter-gripper (14) are hinged to the pendulum arm (8) as working equipment, that the clearing rake (10) and counter-gripper (14) can be pivoted independently of one another and moved in a pincer-like manner relative to one another by means of hydraulic working elements (9 and 15) hinged to the pendulum arm (8), and that the clearing rake (10) and counter-gripper (14) are curved in the vertical direction with concave sides facing each other, have wide teeth and are designed in a lightweight height frame construction, the clearing rake (10) being wide and high. 2. Excavator according to claim 1,
characterized, that the clearing rake (10) consists of a total of four teeth (26) and three shorter, narrow pinion teeth (30) arranged between the latter, that each tooth consists of two parallel, curved tooth-shaped flat steels (27) and the middle teeth (30) of each consisting of a predominantly wedge-shaped, slightly curved flat steel, that the flat steels (27) of the teeth (26) are welded at the back at their upper end to a pair of horizontally running upper square tubes (21,22), approximately in the middle of their length to a pair of lower, horizontally running square tubes (23,24), that the flat steels of the middle teeth (30) are welded to the lower pair of square tubes (23,24), that above the teeth (26) on the upper pair of square tubes (21,22) a pair of connecting lugs (36) with bearing bushes (37) arranged at the end for receiving a through the free end of an intermediate link (11) which is connected to the piston rod (13) of the hydraulic cylinder (9) of the pendulum arm (8) are welded obliquely upwards and over the back of the teeth (26), that a further pair of connecting lugs (33) are welded to the upper pair of square tubes (21, 22) at a distance corresponding to the width of the pendulum arm (8) and with bearing bushes (34) arranged at the end for receiving a connecting bolt (35) running through the end of the pendulum arm, essentially pointing upwards and forwards in relation to the teeth (26), and that the two pairs of connecting lugs (33 and 36) are arranged symmetrically to the vertical center plane of the clearing rake (10) running parallel to the teeth (26). 3. Excavator according to claim 1 and/or 2, characterized in
that between each flat steel (27) of the teeth (26) and each adjacent square tube (22 and 23) triangular bracing angles (29) are welded in, that a stiffening tube (28) is welded centrally between each two adjacent teeth (26) and running parallel to them, between the upper and lower pairs of square tubes (21, 22 and 23, 24), whereby the tube (25) welded symmetrically in the vertical center plane of the clearing rake (10) is wider than the others and is preferably designed as a square tube. 4. Excavator according to one or more of claims 1 to 3, characterized, that on the lower edge of the lower pair of square tubes (23, 24) there are flat intermediate pieces (31) made of flat steel, with their free lower edge (32) being curved and grooved, with their plane running approximately in the wedge center line of the center teeth (30) and welded to the adjacent center tooth (30) or flat steel (27) of the tooth (26). 5. Excavator according to one or more of claims 1 to 4, characterized, that adapters (43) for the detachable fastening of drop-forged, hard steel teeth (45) are welded to the lower end of the teeth (26). 6. Excavator according to one or more of claims 1 to 5, characterized, that with their length in extension of the respective both teeth (26) lying on either side of the vertical plane of the clearing rake (10), upwardly extending angles (38) are welded to the upper pair of square tubes (21,22) and are each connected by means of a tube (40) with a circular cross-section welded to their upper ends, that the legs (39) of these angles (38) running parallel to the vertical plane of the clearing rake (10) run with their rear edge diagonally from the square tube (21) to the circular tube (40), while the other legs run in the front or working surface of the clearing rake (10), that parallel to the vertical plane of the clearing rake (10), in the middle between the two angles (38), an intermediate flat steel (41) is between the upper square tube (21) and is welded into a circular pipe (40), the front edge of which is an extension of the concavely curved front surface of the clearing rake (10) and the rear edge of which runs obliquely like the parallel legs of the angle (38), and that the angle (38), intermediate flat steel (41) and circular tube (40) are designed together on both sides of the connecting lugs (33) as an attachment (42) which enlarges the front or working surface of the clearing rake (10) upwards. 7. Excavator according to one or more of claims 1 to 6, characterized, that on the side of the pendulum arm (8) facing the excavator chassis (2), approximately at the level of the articulated abutment of the hydraulic cylinder (9) for operating the clearing rake (10) arranged on the opposite side of the pendulum arm (8), the abutment end of a additional, double-acting
hydraulic cylinder (15), that on the same side of the pendulum arm (8), near its end, a pair of tabs (51) is welded, in which the upper end of the counter-gripper (14) is pivotally mounted by means of a bolt (50), and that the additional hydraulic cylinder (15) is articulated with the free end of its piston rod (17) by means of a bolt (53) to the counter-gripper (14), whereby this articulation point (18) is located from the upper, articulated end (19) of the counter-gripper (14) by approximately one third of the total height, or length, of the counter-gripper (14). 8. Excavator according to one or more of claims 1 to 7, characterized, that the counter-gripper (14) consists of two curved tooth-shaped flat steel teeth (46) which are connected at the top, approximately at a distance of one quarter, and at the bottom, approximately at a distance of one third of the total length of the teeth (46), from the upper and lower ends by means of a horizontally arranged and welded square tube (47 and 48 respectively), that at the upper end of the teeth (46) bearing bushes (49) for the bolt (50) in the pair of tabs (51) of the pendulum arm (8) are attached, that two flat steel bars (52) running at a distance from each other, parallel to each other and to the teeth (46), symmetrically to the longitudinal center line are welded between the two square tubes (47 and 48), and that between these two flat steels (52) a bolt (53) is held and on this bolt (53) the Bearing bush at the end of the piston rod (17) of the additional hydraulic cylinder (15). 9. Excavator according to one or more of claims 1 to 8, characterized, that a reinforcing flat steel (54) is welded between each flat steel (52) for supporting the bolt (53) and the adjacent tooth (46) of the counter-gripper (14), and that the surfaces of these reinforcing flat steels (54) are essentially flush with the radius of the arc on the concave side of the teeth. 10. Excavator according to one or more of claims 1 to 9, characterized, that the tip areas of the teeth (46) of the counter-gripper (14) are reinforced by means of steel plates (55) welded on both sides. 11. Excavator according to one or more of claims 1 to 10, characterized,
that a steel sheet (56) is welded to the lower square tube (48) of the counter-gripper (14), the front ends of which are additionally connected to the teeth, the surfaces of which are approximately parallel to the front edge of the tooth tip areas and the tooth-side front edge (57) of which runs along a concave arc from the square tube (48) at a distance of approximately one quarter to one third of the distance from the lower square tube to the tooth tip. 12. Excavator according to one or more of claims 1 to 11, characterized, that old bolts (35,50,53,60) between clearing rake (10) or counter-gripper (14) and pendulum arm (8) as well as between clearing rake (10) or counter-gripper (14) and associated piston rod (13 or 17) are easily loosened, but are rather held in place by means of screw nuts, pins or similar. 13. Excavator according to one or more of claims 1 to 12, characterized, that the counter-gripper (14) can be pivoted to a limited extent in the lower area between the two middle teeth (26) of the clearing rake (10). 14. Excavator according to one or more of claims 1 to 13, characterized, that the clearing rake (10) is approximately 2.10 m wide and 1.32 m high and has a clearance of 0.55 m between the teeth (26), that the counter-gripper (14) is 1.30 m high and a maximum of 0.55 m wide, and that the clearing rake (10) and counter grapple (14) can be pivoted apart with the tooth tips to a mutual distance of 2.8 m. 15. Excavator according to one or more of claims 1 to 14, characterized, that the clearing rake (10) and counter grapple (14) have a combined weight of no more than 1,000 kg.