WO2002001939A1

WO2002001939A1 - Method of harvesting energy wood, and harvesting apparatus

Info

Publication number: WO2002001939A1
Application number: PCT/FI2001/000624
Authority: WO
Inventors: Pasi Romo
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-07-03
Filing date: 2001-06-29
Publication date: 2002-01-10
Anticipated expiration: 2003-01-03
Also published as: FI20001590A0; AU2001272608A1; FI110659B; FI20001590L

Abstract

The invention relates to a method of harvesting energy wood and to a harvesting apparatus. The harvesting apparatus (1) comprises a feed conveyor (3) that transport wood to be processed through a feed opening (8) to a feed chamber (10). After a suitable batch is fed in, cutting is performed by a cutting apparatus (12) between the feed conveyor and feed chamber. The feed chamber has a feeding blade (23) which is arranged to be turnable, substantially parallel to and substantially equal in length with the feed chamber, and which after cutting moves the wood batch sidewise away from the feed opening, thus enabling the feeding of new wood through the feed opening into the feed chamber. According to a preferred embodiment of the invention, the feeding blade turns back and forth, thus moving the cut wood away from the feed opening alternately to different sides relative to the feed opening.

Description

METHOD OF HARVESTING ENERGY WOOD, AND HARVESTING APPARATUS

[0001] The invention relates to a method of processing energy wood, the method comprising the steps of feeding wood to a feed conveyor belonging to a harvesting apparatus, transporting wood by means of the feed conveyor through a feed opening to a feed chamber of the harvesting apparatus, feeding a predefined amount of wood to the feed chamber, after which performing cutting to a desired length by means of a cutting apparatus between the feed chamber and the feed conveyor, and further, the method comprising the step of compressing wood to reduce its volume and to form a wood bundle.

[0002] The invention further relates to a harvesting apparatus for processing energy wood, which harvesting apparatus comprises a feed conveyor and a feed chamber, and the feed conveyor is arranged to transport wood fed to it through a feed opening to the feed chamber, a cutting apparatus which is arranged between the feed conveyor and the feed chamber and which cutting apparatus is arranged to cut a wood batch fed into the feed chamber, and further, means for compressing wood to a smaller volume.

[0003] More and more attention is being paid to utilising logging residue and corresponding wood fuel in energy production, as the prices of oil and other fossil fuels increase. Ever stricter environmental regulations and the opposition to nuclear energy also increase the attractiveness of using wood in energy production.

[0004] At the moment, the use of small-dimensioned wood and logging residue is relatively small. A more extensive use is prevented by the fact that an economically profitable way of processing wood fuel and transporting it from the forest to an combustion plant has not been found, and oil and coal are still less expensive alternatives due to the high processing costs of wood. To harvest logging residue, i.e. branches, twigs, top refuse and any corresponding wood material, from the forest after logs have been harvested, a bundling machine arranged on the carrier of a forest machine has been developed for bundling and string-tying any wood material fed into the machine into an elongated bundle that is easier to handle. These bundles are collected from the forest by normal forest machines and transported by lumber transport trucks used in transporting logs to a chipping location where the bundles are crushed into small chips before combustion. Chipping can be done at the combustion plant, in which case it can be directly used in the plant or alternatively, chipping can be done at a separate centralised chipping location and the chips transported to the combustion plant. In comparison with conventional chipping in the forest or by the road, this provides the advantage, for instance, that chipping can be done in better conditions and with more efficient chipping machines.

[0005] One bundling machine on the market comprises a feeding table, to which logging residue to be baled is fed and which transports the logging residue to a feed chamber in which the logging residue is grabbed by jaws which compress the logging residue and, at the same time, pull it forward towards a tying station at the outlet end of the feed chamber, where the created logging residue bundle is tied with a string. The machine in question makes a continuous logging residue bundle which, after tying, is cut by a chain saw into bundles of predefined length at the tail end of the apparatus. A problem with the machine in question is that other functions of the machine, such as feeding and tying, are interrupted during the cutting of the bundle, which is why the use of the machine is not efficient. A further problem is that logging residue must be fed evenly on the feeding table, since too high a feeding rate blocks the machine, and correspondingly, with too low a feeding rate, the machine does not start to make the bundle at all. A suitable amount of wood must continuously be on its way into the feed chamber. This hampers essentially the work of the machine operator and slows down the operation of the machine. Yet another difficulty with the machine is that the finished tied bundle is cut with a chain saw. In such a case, stresses in the compressed bundle relax due to cutting and may break the chain saw. If there are slanting wood ends at the cutting point, they can easily pry the saw blade to the side and may damage the operation of the saw.

[0006] Further, a logging residue bundling machine is known that has several parallel rollers and arranged in a circle. Logging residue to be bundled is fed into a feed chamber between the rollers through a feed opening above the rollers. The rotating rollers work the logging residue into a roll that is, at the end, tied and dropped into the forest to be collected later. A difficulty in this solution is that logging residue must be fed evenly into the feed chamber surrounded by the rollers along the entire length of the chamber, because otherwise the thickness of the bundles will not be even. Further, the machine operator must monitor the moment when the feed chamber is full. Logging residue cannot be fed during tying and the removal of the ready bundle. Thus, the feeding and use of the apparatus in question is slow and difficult. Another drawback is that the apparatus is not at all suitable for processing long poles, but can only be fed relatively short branches and twigs. [0007] It is an object of the present invention to provide a new type of method and harvesting apparatus for processing energy wood.

[0008] The method of the invention is characterized by moving by means of a turning feeding blade in the feed chamber a cut wood batch away from the feed opening in transverse direction to the feed direction.

[0009] Further, the apparatus of the invention is characterized in that the feed chamber has a feeding blade which is substantially parallel to the feed chamber and substantially of the same length as the feed chamber, and that the feeding blade is arranged to move in substantially transverse direction to the feed direction the wood batch cut by the cutting apparatus aside from the feed opening and out of the way of a new wood batch being fed in to the feed chamber.

[0010] An essential idea of the invention is that a suitable batch of the wood being processed is fed into the feed chamber from the feed opening, after which cutting is done by a cutting apparatus arranged at the feed opening. After cutting, the tumably arranged feeding blade in the feed chamber moves the wood batch in the feed chamber at the feed opening to the side for further processing, and a new wood batch can again be fed substantially immediately into the feed chamber.

[0011] Further, an essential idea of a preferred embodiment of the invention is that the cutting apparatus comprises a disc-like blade that is arranged to move back and forth. Cutting by the guillotine principle is very fast. In addition, cutting is reliable and inexpensive. In addition, an advantage is that the feed opening can be closed by means of the cutting blade so as to prevent the passing of the material through the feed opening. The feed conveyor can then be a continuous conveyor. [0012] An essential idea of a second preferred embodiment of the invention is that the feeding blade is arranged to move back and forth and that cutting is arranged so that the feeding blade moves the cut wood batch alternately to different sides relative to the feed opening. When the drives of the feeding blade and the cutting blade are suitably synchronized, feeding and cutting are very fast. [0013] An essential idea of a third embodiment is that below the feeding chamber, a compression chamber is arranged, being defined by jaws that press against each other and compress the wood fed into the compression chamber from the feed chamber and work it into a wood bundle. Further, when closed, the jaws form a wall between the feed chamber and the compression chamber, and when the compression chamber is emptied, cut wood batches can be moved by means of the feeding blade for intermediate storage on top of the jaws. When the compression chamber can again receive wood, the jaws are opened and the feed chamber is again open to the compression chamber and by means of gravity and the feeding blade, wood can enter the compression chamber for further processing. This way, new wood can continuously be fed into the feed chamber and cut and stored temporarily there while the compression chamber is emptied. Using two chambers thus evens out the material flow being fed. When the feed chamber and the compression chamber are arranged on top of each other, the harvesting apparatus can be short and compact.

[0014] It should be noted that in this application, the terms 'energy wood' and 'wood' refer to different kinds of logging residue, such as branches, twigs, and top refuse, and also to longer wood with a larger diameter, such as logs, and to building waste wood, for instance.

[0015] The invention is described in greater detail in the attached drawings, in which

Figure 1a is a schematic side view of a harvesting apparatus of the invention in its transport position and transported by a forest tractor, and Figure 1 b shows a corresponding apparatus in its operating position as seen from the back of a forest machine,

Figure 2a is a schematic side view of the feed end of a harvesting apparatus of the invention, and Figure 2b shows the principle of cutting,

Figures 3a and 3b are simplified schematic representations of the structure of harvesting apparatuses of the invention as seen from the feed end side,

Figure 4 is a schematic representation of a harvesting apparatus of the invention as seen from the discharge end side,

Figure 5 shows a schematic side view of a bundling apparatus to be arranged to a harvesting apparatus of the invention, and Figures 6a to 6c are schematic representations of the principle of yet another embodiment of the invention.

[0016] Figure 1a shows in a simplified manner a harvesting apparatus 1 which is arranged on the carrier 2a of a normal forest machine 2. Other moving carriers can naturally also be used. In the figure, the harvesting apparatus is in its transport position, in which it is longitudinal to the forest machine and hampers off-road driving as little as possible. In its transport position, a feed conveyor 3 of the harvesting apparatus is turned on top of the harvesting apparatus and similarly, a discharge plate 4 at the tail end of the apparatus is in its up position, thus making the harvesting apparatus as short as possible. The harvesting apparatus is arranged on the carrier 2a of the forest machine in such a manner that it can be turned around a vertical axis A from the transport position to the operating position. The operating position is shown in Figure 1 b. [0017] In its operating position, the harvesting apparatus is transverse to the longitudinal axis of the forest machine. The feed conveyor 3 and the discharge plate 4 are down. Energy wood 11 to be processed is then lifted by means of a loader 5 of the forest machine onto the feed conveyor. On the bottom surface of the feed conveyor, there is a conveyor chain 7, belt or the like running around turning rolls 6a and 6b marked with dashed lines that moves in the direction B towards a feed opening 8. Further, the feed conveyor has a feed roll 9 arranged at the feed opening and on top of the conveyor chain to press the wood being fed in such a manner that it fits through the feed opening inside a feed chamber 10. The feed roll is rotated in the direction C. There may be protrusions on the surface of the feed roll to increase friction between the roll and wood. Further, the feed roll is arranged in such a manner that its height can change according to the wood being fed. There may also be rotating rolls or the like at the vertical edges of the feed opening to help the flow of wood fed into the feed chamber. There is a cutting apparatus 12 between the feed chamber and feed conveyor for cutting after the feed conveyor has filled the feed chamber in a predefined manner. Cutting can be done when sensors arranged to the feed conveyor detect that the feed force exceeds a predefined limit value, at which point it can be concluded that a required batch has been fed in. Further, the cutting time can in some cases be determined by means of sensors arranged in the feed chamber or by measuring the length of the wood moved by the feed conveyor. Cutting is preferably done by means of a guillotine-type disc-like cutting blade 13 that is moved in a transverse direction D to the feeding direction. After cutting, the wood is moved by means of a feeding blade to be described later to a compression chamber 14 below the feed chamber. In the compression chamber, the wood is compressed to form an elongated wood bundle 15 which is substantially circular in diameter and whose length corresponds to the length of the wood batches fed and cut in the feed chamber. A wood bundle is made up of several batches cut in the feed chamber. After compression, the wood bundle is pushed out of the compression chamber for instance by means of an ejecting plate 17 operated by an ejecting cylinder 16. The compression chamber has a discharge end 18 that opens, and in connection with it outside the compression chamber, there is a compression apparatus 19 for further compressing the wood bundle in the transverse direction to make it tighter. When the wood bundle is ejected, it is pushed outward to the extent that the end of the bundle can be pressed and during the pressing, a tying string 21 can be wound around the pressed point of the bundle by means of a tying apparatus 20 to tie the bundle and to maintain the change of shape produced by the additional compression, thus enabling the production of very tight bundles. Tying is continued in such a manner that a predefined length of the wood bundle at a time is pushed outwards by the ejecting cylinder and the additional compression and tying is performed. During tying, the bundle is supported by the discharge plate 4. After tying, the wood bundle is dropped into the forest. A normal forest tractor later moves the bundles to the side of a forest road, where they are allowed to dry before being transported for chipping. The processing breaks the wood bark, which speeds up the drying of the bundles in a preferable manner.

[0018] Figure 2a shows the feed end from the side. The feed conveyor has a feed chain 7 that runs around turning rolls 6a and 6b. Above a feed opening 8, there is a feed roll 9 that is arranged to be movable in elevation. Cutting is done by means of a reciprocating cutting blade 13 that is preferably operated by a pressure medium cylinder. In its low position, the cutting blade goes between a first and a second counter blade 22a and 22b. In the case shown in the figure, the body of the harvesting apparatus serves as the first counter blade 22a and the second counter blade 22b is a separate disc-like piece arranged in such a manner that the slot required by the cutting blade with respect to the first counter blade is formed. The outermost edge 22b' of the second counter blade 22b is preferably curved so that a turning feeding blade 23 moves along its outermost edge moving the wood cut by the cutting blade away from the feed opening. The feeding blade is shaped so that it moves as close as possible to the front surface and outer rim of the feed chamber. In Figure 2b, the first counter blade is not made up by the body, but both counter blades 22a and 22b are separate pieces. In its low position, the cutting blade closes the feed opening so that the cut batch cannot exit the feed chamber and the feed conveyor can be a continuous conveyor. The operation of the feed conveyor can also be interrupted during cutting. [0019] Figure 3a shows a harvesting apparatus of the invention as seen from the feed end side. In the figure, the structure has been simplified by leaving out the feed conveyor and other parts before the feed and compression chambers for clarity's sake. The harvesting apparatus comprises a feed chamber 10 with a compression chamber 14 below it. A cutting blade 13 cuts wood fed to a feed opening 8 after a suitable batch of wood has been fed against the back wall of the feed chamber. In a manner of speaking, the cutting blade separates a batch having the length of the feed chamber from the material flow being continuously fed by the feed conveyor. The cut wood batch is moved away from the feed opening 8 by means of a turning feeding blade 23 alternately to either side of the feed opening, or in some cases, to one side only. The feeding blade is substantially as long as the feed chamber, but it can also be made up of several adjacent blades that together form a blade substantially as long as the feed chamber. The feeding blade is arranged by means of a shaft 24 parallel to the feed chamber at the bottom part of the feed chamber, and it can be turned by means of a hydraulic motor or pressure medium cylinders that are not shown in the figure. The feeding blade can be turned between jaws 25a and 25b limiting the bottom part of the feed chamber. The inner surface 10a of the feed chamber is substantially in the shape of a circular arc in the section where the feeding blade turns. As shown in the figure, the pushing edges of the feeding blade are shaped to substantially correspond to the shape of the jaws. The figure further shows a counter blade 22 below the feed opening, and the curved shape of its top surface, which makes the flow of the cut material easier.

[0020] The compression chamber 14 has jaws 25a and 25b that open and close and with which the cut wood is compressed to make it into a tight bundle. The jaws are pivoted at their lower ends and they are moved by means of a pressure medium cylinder 26. When closed, the jaws form a wall between the feed chamber and compression chamber preventing the wood from moving between the chambers. When the jaws are opened, the cut wood is pushed by the feeding blade and drops into the compression chamber. The force resisting the press of the jaws or their distance of travel can be monitored to find out when an amount of wood sufficient for making a bundle has been fed into the compression chamber.

[0021] The solution shown in Figure 3b differs from the solution of the previous figure only in the cylinders 26 operating the jaws, which now are arranged at the side of the harvesting apparatus. The cylinder operating the cutting blade 13 is marked by reference numeral 27 in the figure.

[0022] Figure 4 shows a harvesting apparatus as seen from the discharge end. For clarity's sake, all parts belonging to the structure have not been shown. In the situation of the figure, jaws 25a and 25b are closed and prevent the feeding of wood into a compression chamber. A feeding blade 23 then moves the cut wood 28 against the top surface of the jaws and at the same time pre-compresses and shapes the wood. This way, wood is temporarily stored in the feed chamber until it can be fed into the compression chamber. It is thus possible to feed and cut wood continuously. When the compression chamber is again ready to receive wood, the jaws are opened and the wood is pushed by means of the blade to the compression chamber. The figure further shows that at the discharge end of the apparatus on an extension of the compression chamber, there is a compression apparatus comprising two compression jaws 29a and 29b which during compression are moved by means of cylinders 30 towards each other as shown by the dashed lines to further compress the bundle 31 formed in the compression chamber when it is pushed out. The compression jaws are moved along guide bars 32. The discharge end of the compression chamber is closed by means of the compression jaws during the compression of the bundle. The fact that a compressed bundle comes out of the compression chamber more easily should also be mentioned as an advantage of the additional compression.

[0023] Figure 5 shows a side view of a bundling apparatus that can be arranged at the discharge end and comprises an additional compression unit 29 and a tying apparatus 33. The tying apparatus is arranged in immediate proximity to the compression jaws in such a manner that string can be wound beside the point of the bundle being pressed so as to make the bundle tight. The tying apparatus comprises a ring 34, through which the bundle goes when exiting and which guides the tying mechanism 35 around the bundle. A required number of string coils 36 can be arranged to the tying mechanism, from which the tying string 21 runs around the bundle when the tying mechanism is circulated around the bundle. The tying apparatus can also comprise a device for making knots in the strings around the bundles or alternatively, the string is tied around the bundle so many times that it stays tightly around it without a knot. Hemp string impregnated by a suitable protective agent is preferably used as the tying string, but other suitable strings that endure the required compression force and weather conditions can also be used.

[0024] Figures 6a to 6c show a second embodiment of the invention, in which wood cut in a feed chamber 10 is fed to a transport unit 37 or the like in connection with the feed chamber. As in the embodiments described earlier, in this, too, a feed conveyor feeds a desired amount of wood through a feed opening 8 to the feed chamber 10, after which the wood is cut by a cutting blade 13. The cut wood batch is moved by means of a feeding blade 23 away from the feed opening 8, to the left of the feed opening in the figure. The feeding blade moves the wood batch 11 to the reach of a packing blade 38 in the feed chamber, as shown by a dashed line 39 in the figure. The packing blade is arranged to push the wood batch 11 into the transport unit, as shown in Figure 6b. The packing blade is arranged to turn to the extent of a predefined turning angle in relation to its shaft 40 in the same way as the feeding blade turns in relation to its own shaft 24. The shafts 24 and 40 are longitudinal to the feed chamber and at a distance from each other. The blades can be turned for instance by means of a hydraulic cylinder or a corresponding unit. In the solution of the figure, both blades are substantially in the shape of a circular sector in cross-section. The feeding blade is arranged to move along the curved bottom 41 of the feed chamber, whereby it pushes the wood carefully away in front of it. The pushing edge 42 of the feeding blade is made curved in a manner corresponding to the outer rim 43 of the packing blade so that when the feeding blade is in its extreme position at the discharge end side, the packing blade can turn along the pushing edge 42 of the feeding blade and push the wood 11 with its pushing edge 44 onward to the transport unit 37. Alternatively, the packing blade can push the wood onto a conveyor, for instance, which feeds the wood directly to a chipping machine or a truck pallet for onward transportation. The cutting blade closes the feed opening while the feeding blade is turned towards the packing blade. Further, because the packing blade moves along the feeding blade, it carefully detaches any impurities attached to the pushing edge of the feeding blade. [0025] In Figure 6c, the transport unit 37 is a container that has a hatch 45 that can be opened and closed at its front end. The packing blade can be arranged so that the hatch of the container can be pushed open and closed by means of it. Inside the container, a movable plunger 46 is arranged that can be supported to the inside surfaces of the container by means of slide blocks or rolls, for instance. The plunger is moved towards the front of the container by means of a unit not belonging to the container. Force is then transmitted to the plunger by means of suitable transmission elements. During the process, wood is fed from the feed chamber into the container by the feeding and packing blades through the open front end of the container, and at the beginning of the feed, the plunger is at the front end of the container and moves gradually backwards pushed by the wood being packed into the container. Because the plunger somewhat resists the feeding of the wood into the container, it compresses the wood and also makes the container fill to the top. After the container is full, it is closed and detached from the harvesting apparatus. The container can be left in the forest to be collected later. When unloading the container, its front end is opened, after which the plunger inside the container is pushed towards the front end of the container by means of a unit, such as a hydraulic cylinder, arranged to an external machine, such as a forest machine or truck, whereby the content of the container is pushed out. [0026] The drawings and the related description are only intended to illustrate the idea of the invention. The invention may vary in detail within the scope of the claims. Thus, in some cases, the harvesting apparatus can be arranged so that it is not moved at the harvesting location, but the wood to be processed is brought from the forest by other means to be processed. Further, cutting can in some cases be done by other means than by the described cutting blade. In practice, the harvesting apparatus comprises sensors for monitoring the operation of the harvesting apparatus, and a control unit for automatically controlling the operation of the harvesting apparatus. The operator then only needs to feed wood to be processed onto the feed conveyor. The use of a feeding blade speeds up the feeding and cutting of wood substantially. Because the feeding and cutting are done one batch at a time, and a finished bundle is made up of several batches, feeding the wood into the apparatus is clearly easier than in prior art solutions. Further, the apparatus of the invention is suited for processing many kinds of wood. It can process branches and twigs, but on the other hand, it is also suited for processing logs, for instance. It can also process wood with small and large diameters at the same time. It is suited for processing both short and long wood.

Claims

1. A method of processing energy wood, the method comprising the steps of feeding wood to a feed conveyor (3) belonging to a harvesting apparatus, transporting wood by means of the feed conveyor (3) through a feed opening (8) to a feed chamber (10) of the harvesting apparatus, feeding a predefined amount of wood to the feed chamber (10), after which performing cutting to a desired length by means of a cutting apparatus (12) between the feed chamber (10) and the feed conveyor (3), and further, the method comprising the step of compressing wood to reduce its volume and to form a wood bundle, characterized by moving by means of a turning feeding blade (23) in the feed chamber (10) a cut wood batch away from the feed opening (8) in transverse direction to the feed direction.

2. A method as claimed in claim 1, characterized by cutting the wood by a cutting blade (13) that is moved back and forth.

3. A method as claimed in claim 1 or 2, characterized by turning the feeding blade (23) back and forth between its extreme positions to both sides relative to the feed opening (8), feeding and cutting the wood batch during each turning movement of the feed blade (23), and moving by means of the feed blade (23) the wood batch at the feed opening (8) alternately to different sides relative to the feed opening (8).

4. A method as claimed in any one of the preceding claims, characterized by moving the cut wood by means of the feed blade (23) to a compression chamber (14) below the feed chamber (10), compressing the wood in the compression chamber (14) in transverse direction by means of one or more jaws (25a, 25b) in the compression chamber (14) along substantially the entire length of the compression chamber (14) to produce a desired wood bundle, and removing the ready wood bundle from the compression chamber (14) by pushing it in its longitudinal direction out through an openable end of the compression chamber (14).

5. A method as claimed in claim 4, characterized by winding a tying string (21) around the wood bundle to be removed from the compression chamber (14) at predefined locations to hold the formed bundle together.

6. A method as claimed in claim 5, characterized by compressing the bundle to be removed from the compression chamber (14) together in transverse direction at least at a section of its length, and winding the tying string (21 ) simultaneously around the compressed section of the bundle to provide a tight bundle.

7. A method as claimed in claim 1 or 2, c h a r a c t e r i z e d by moving the cut wood batch by means of the feeding blade (23) to the reach of a parallel packing blade (38) arranged in the feed chamber (10), and moving the wood batch out of the feed chamber (10) by turning the packing blade (38).

8. A harvesting apparatus for processing energy wood, which harvesting apparatus (1) comprises a feed conveyor (3) and a feed chamber (10), and the feed conveyor (3) is arranged to transport wood fed to it through a feed opening (8) into the feed chamber (10), a cutting apparatus (12) which is arranged between the feed conveyor (3) and the feed chamber (10) and which cutting apparatus (12) is arranged to cut a wood batch fed into the feed chamber (10), and further, means for compressing wood into a smaller volume, c h a r a c t e r i z e d in that the feed chamber (10) has a feeding blade (23) which is substantially parallel to the feed chamber and substantially of the same length as the feed chamber, and that the feeding blade (23) is arranged to move in substantially transverse direction to the feed direction the wood batch cut by the cutting apparatus (12) aside from the feed opening (8) and out of the way of a new wood batch being fed in to the feed chamber (10).

9. A harvesting apparatus as claimed in claim 8, c h a r a c t e r i z e d in that the cutting apparatus (12) comprises a disc-like cutting blade (13) that is arranged to move back and forth.

10. A harvesting apparatus as claimed in claim 8 or 9, c h a r a c t e r i z e d in that below the feed chamber (10), there is a compression chamber (14), that the compression chamber (14) has at least one openable and closeable jaw (25a, 25b) which is substantially as long as the compression chamber (14) and which when closed is arranged to separate the feed chamber (10) and the compression chamber (14) from each other preventing wood from moving from the feed chamber (10) to the compression chamber (14), that when the jaw (25a, 25b) is open, the feeding blade (23) is arranged to move wood from the feed chamber (10) to the compression chamber (14), that said jaw (25a, 25b) is when closing arranged to compress the wood in the compression chamber (14) to a smaller volume, that there are sensors in the compression chamber (14) to detect the filling up of the compression chamber (14), that at least one end of the compression chamber (14) is openable, and that there are discharge elements (16, 17) in the compression chamber (14) to move the compressed wood bundle from the compression chamber (14) through said openable end.

11. A harvesting apparatus as claimed in claim 10, characterized in that on an extension of the compression chamber (14), there is a bundling apparatus which comprises a compression apparatus (29) for additional transverse compression of a wood bundle discharged from the compression chamber (14) and a tying apparatus (33) for winding a tying string (21) around the compressed wood bundle for tying the bundle.

12. A harvesting apparatus as claimed in claim 11, characterized in that the tying apparatus (33) is arranged in immediate proximity to the compression apparatus (29), that the discharge elements (16, 17) of the compression chamber (14) are arranged to push the wood bundle to be discharged from the compression chamber (14) in stages a predefined length, that the compression apparatus (29) of the bundling apparatus is arranged to compress the wood bundle coming out of the compression chamber (14) between said stages, and that the tying apparatus (33) is arranged to immediately wind the tying string (21) around the wood bundle in immediate proximity to the location being compressed together by the compression apparatus (29) to provide a tight wood bundle.

13. A harvesting apparatus as claimed in any one of claims 8 to 12, characterized in that the feeding blade (23) is arranged to make a back-and-forth turning movement and to feed the wood at the feed opening (8) alternately to different sides relative to the feed opening (8).

14. A harvesting apparatus as claimed in any one of claims 10 to

13, characterized in that in the compression chamber (14), there are a first and a second curved jaw (25a, 25b), that each jaw is separately pivoted at its low end, that the jaws (25a, 25b) are arranged to open away from each other, that closed jaws form together a wall between the feed chamber (10) and the compression chamber (14) and limit the compression chamber (14) between them, and that the feeding blade (23) is arranged to turn back and forth in the feed chamber (10) substantially between the jaws (25a, 25b), whereby the feeding blade (23) is arranged to move the wood batches fed into and cut in the feed chamber (10) alternately to the side of the first jaw and to the side of the second jaw.

15. A harvesting apparatus as claimed in claim 14, characterized in that the shape of the feeding blade (23) surface pushing the wood batch corresponds substantially to the shape of the curved jaws (25a, 25b), in which case the feeding blade (23) can be arranged against the surface of the jaws (25a, 25b) on the feed chamber side (10), and that the jaw is arranged when closing to scrape off any wood attached to the pushing surface of the feeding blade (23).

16. A harvesting apparatus as claimed in claim 14 or 15, characterized in that the first and the second jaw (25a, 25b) are closed for the time the compression chamber (14) is emptied, that the feeding blade (23) turning back and forth during the emptying of the compression chamber (14) is arranged to move the wood batches fed into the feed chamber (10) after cutting alternately against the surface of the first jaw and the surface of the second jaw on the feed chamber side, i.e. the top surface, thus storing the wood fed into the feed chamber (10) during the emptying of the compression chamber (14), and that after the emptying of the compression chamber (14), the jaws (25a, 25b) are arranged to open, and the feeding blade (23) when turning is arranged to push the wood temporarily stored above the jaws into the compression chamber (14).

17. A harvesting apparatus as claimed in claim 8 or 9, characterized in that in the feed chamber (10), there is a turning packing blade (38) substantially parallel to the feeding blade (23), that the feeding blade (23) is arranged to move the cut wood batch away from the feed opening (8) to the reach of the packing blade (38), and that the turning packing blade (38) is arranged to move the wood batch on out of the feed chamber (10).

18. A harvesting apparatus as claimed in claim 17, characterized in that a transport unit (37) connected to the feed chamber (10) is detachably attached to the harvesting apparatus (1), that the packing blade (38) is arranged to move the wood batch into said transport unit (37).

19. A harvesting apparatus as claimed in claim 18, characterized in that the transport unit (37) is a container and that inside the container, a plunger (46) is arranged, which is moved by a unit separate from the container, for unloading the wood packed into the container by moving said plunger (46).

20. A harvesting apparatus as claimed in any one of claims 8 to 19, characterized in that the harvesting apparatus (1 ) is arranged on a movable carrier (2a).