Field of the invention

The present invention concerns an apparatus and a method for cutting of packaged bales. For example, such bales may contain waste, textiles, straw or similar materials. The packaging for the bales may be comprised of thread, for example textile thread or steel wire,- straps, for example nylon straps or steel straps; and/or wrapping material, for example textile wrapping or plastic film wrapping. The packaging may also be comprised of other types of cuttable materials .

In order to be used for other purposes, for example as fuel in an industrial incineration plant, the contents of the bales must normally be transported to a remote location for storage and/or further treatment. For this reason, it is practical and saves on costs to compress and package the contents in bales of a suitable shape, for example as hard- packed bales .

In order for the contents of the bales to be utilized or treated further at a user location, for example a remote heating plant, the packaging of the bales must first be cut in a suitable manner. This is what the present invention is concerned with. Having cut the packaging, the contents of the bales and the packaging may be treated further. Such further treatment does not concern the present invention.

Background of the invention The background of the invention relates to various disadvantages associated with known methods and/or equipment for cutting of packaged bales. These disadvantages are both in terms of operation, time, cost and safety.

Prior art and disadvantages thereof The simplest method for cutting of such packaged bales is to carry out manual cutting by means of a knife or a similar implement. Such a method, however, may be dangerous and time- consuming and oftentimes unpractical in an industrial setting.

In an industrial setting, mechanical cutting of such packaged bales is frequently used. For this purpose, an industrial shredder or a so-called bale cutter is commonly used.

Typically, industrial shredders make use of parallel rollers provided with cutting elements being rotated towards each other. Material to be disintegrated is introduced between the rollers and their cutting elements for crushing and/or grinding. Such shredders are best suited for splitting material suitable for grinding or crushing into smaller pieces.

The bale cutters, however, make use of disc-, plate- or rod- resembling cutting devices provided with knife blades, saw blades, cutting teeth or similar cutting elements. The primary purpose of such cutting machines is to cut/open the packaging surrounding a bale. Two types of bale cutters are generally used. The first type of bale cutter is a so-called guillotine cutter typically comprising a frame structure provided with a vertically movable cutting knife or a knife-edge-provided cutting plate. A packaged bale is placed within the frame structure and below the cutting knife or the cutting plate. The cutting knife/cutting plate is then guided with great force towards the bale for cutting the packaging thereof, possibly also for splitting the actual bale. Such packaging may be comprised of thread, straps or wrapping material, for example textile wrapping or plastic film wrapping.

The second type of bale cutter comprises a cutting device, typically in the form of a disc, plate, arm or similar. A cutting machine provided with such a cutting device normally comprises a knife blade or cutting teeth that are brought into contact with a packaged bale for cutting the packaging thereof, which may be comprised of the above-mentioned types of packaging. This type of bale cutter is mainly concerned with cutting of bale packaging, i.e. cutting of material enclosing a bale. It is this type of bale cutter that is most relevant with respect to the present invention. As examples of prior art concerning this type of bale cutter (cutting machine) , the following patent publications are mentioned:

- SU 738960;

- SE 394097; - US 5.901.626;

- SE 394096; and

- US 4.328.609.

All of these cutting machines require a controlled placement or feeding of packaged bales. This implies that the bales must be aligned successively, possibly must be aligned with associated guiding devices, for conveyance onto the cutting machine. The requirement of such a structured placement of individual bales or alignment of several bales, require extra work effort, possibly also extra equipment, during unloading and subsequent placement of the bales, for example on a suitable cutting platform or on a conveyor belt leading onwards to the cutting machine. This involves disadvantages both in terms of operation and cost.

Amongst the latter, second type of bale cutters it is particularly the disc-shaped cutting devices that are most relevant with respect to the present invention. Typically, a cutting machine provided with a disc-shaped cutting device will be attached to a rotatable shaft driven by a suitable motor. Such a cutting machine generally has a fixed placement relative to a movable base, for example a conveyor belt, onto which the packaged bales are conveyed for successive cutting of packaging of individual bales. Additionally, at least one such cutting machine is placed at the fringe of the movable base, but at the same time sufficiently close to the bales for the disc-shaped cutting device to come into contact with the bale packaging for cutting thereof. By so doing, only parts of the disc-shaped cutting device come into contact with the bale packaging. SU 738960 and US 5.901.626 (mentioned above) disclose examples of such cutting machines.

Objects of the invention

The primary object of the invention is to provide an apparatus and a method capable of at least reducing one of said disadvantages of known methods and/or equipment for cutting of packaged bales.

A more specific object is to provide an apparatus and a method for rendering possible to introduce packaged bales in a random position or pattern into a receiving station for feeding onto a cutting machine for the bales. It is also an object to provide a simple and operationally- reliable apparatus for cutting of such bale packaging.

Further, it is an object to provide" an apparatus which is flexible and easy to adapt to different operational conditions and/or types of bales, including bales of different size, shape, contents and/or packaging type.

The objects are achieved by virtue of features disclosed in the following description and in the subsequent claims.

General description of how the objects are achieved In a first aspect of the present invention, an apparatus for cutting of packaged bales is provided, wherein the apparatus comprises :

- a receiving station defined at least by a base and two sidewalls disposed at a distance from each other; - a cutting machine comprising a rotatable shaft provided with at least two transverse cutting devices disposed at a vertical distance from each other for cutting of bale packaging, wherein each cutting device comprises at least one cutting element structured in a manner allowing it to cut through bale packaging upon rotation of the shaft; and

- a support structure disposed above the base and connected to the cutting machine.

The distinctive characteristic of the apparatus is that the cutting machine comprises at least two separate shafts arranged so as to project down into the receiving station, wherein each shaft is provided with at least two of said cutting devices; and

- wherein the shafts are disposed at a distance from each other and at a distance from said two sidewalls of the receiving station.

These distinctive features of the cutting machine of the apparatus are different from all of the above-mentioned, known cutting machines and associated installations.

By means of the present apparatus and cutting machine, the packaged bales may be introduced in a random position or pattern into the receiving station of the apparatus for onwards conveyance and contact with the cutting devices of the cutting machine. Thereby, a controlled alignment or arrangement of the bales for onwards conveyance of the bales is avoided. This implies that a very efficient introduction of the bales into the receiving station may be carried out. For example, the introduction may be carried out by placing the bales on the base of the receiving station, or simply by dumping the bales down onto the base directly from a flatbed of a transport means for the bales . With respect to said prior art, and particularly with respect to said second type of bale cutters provided with disc-shaped cutting devices, this involves obvious advantages in terms of operation and cost.

Moreover, such packaged bales do not necessarily have to be introduced in a random position or pattern into the receiving station. The bales may just as well be guided in a controlled manner into the receiving station. However, this implies not achieving said advantages in terms of operation and cost associated with introduction of randomly oriented bales.

The present apparatus also has other advantages relative to the above-mentioned prior art. The at least two shafts with associated cutting devices and cutting elements of the cutting machine function as rotating beaters projecting down into the receiving station and kneading, cutting and tearing apart the packaging and contents of the bales. By virtue of the shafts projecting down into the receiving station and being surrounded fully or partially by the bales, the cutting devices and cutting elements of the shafts come into very good contact with the bales, which ensures a very efficient disintegration of the bales. This also distinguishes the present apparatus from the above-mentioned, known and disc- shaped cutting devices having only parts thereof coming into contact with the bale packaging.

Hereinafter, constructive features of the present apparatus will be discussed in further detail.

Concerning the receiving station of the apparatus, it may be comprised of, for example, a receptacle, tank, bin, silo, pit or similar receiving structure.

Furthermore, the cutting machine of the apparatus may comprise or be connected to at least one driving device for operational control and rotation of the at least two shafts and associated cutting devices of the cutting machine. For example, the driving device may be comprised of an electric motor, a hydraulic motor or a pneumatic motor.

In one embodiment, only the upper ends of the shafts may be supported in the support structure. This embodiment requires a steady support and bracing of the shafts in order to avoid large lateral movement of the shafts during operation.

In another embodiment, the shafts may be supported both at their upper and lower ends. Thus, the upper and lower ends of the shafts may be connected to the support structure of the apparatus. By means of this embodiment, the shafts may also be supported in a more traditional manner, for example by virtue of the lower ends of the shafts being supported by the base and/or the sidewalls of the receiving station by means of support means known per se. Optionally, the lower ends of the shafts may be supported by structural elements, for example supporting columns, supporting beams or supporting walls, located in vicinity of the present apparatus. Such structural elements may form a part of a building within which the apparatus is placed..

The lower ends of the shafts may also be suspended freely above the base of the receiving station. This embodiment results in maximum freedom of movement for the bales as well as few or no interventions with the base.

Further, the cutting machine may be structured so as to be vertically movable and/or to be horizontally movable to allow the cutting machine to be moved vertically and/or horizontally relative to the base of the receiving station.

Further, the shafts may be directed vertically down into the receiving station. This constitutes a relatively simple and operationally reliable disposition of the shafts.

The shafts may also be directed somewhat aslant, i.e. not exactly vertically, down into the receiving station. Such a disposition of the shafts may enhance the kneading effect on the bales upon rotation of the shafts. Such a disposition, however, may bring about a somewhat larger operational load on the shafts, the cutting machine and associated components.

The support structure of the cutting machine may also comprise a frame structure. This frame structure may be supported by structural elements, for example said supporting columns, supporting beams or supporting walls, in vicinity of the present apparatus .

The frame structure may also be structured so as to be vertically movable, whereby also the cutting machine will be vertically movable if the frame structure is moved in the vertical direction. In order to allow the frame structure (and thus the cutting machine) in the vertical direction, the frame structure may be connected to a hoisting device, for example a winch attached to a supporting beam or similar. Moreover, the cutting machine may be structured so as to be vertically movable and/or horizontally movable relative to the frame structure. This may prove useful to be able to move the cutting machine relative to the base of the receiving station, for example to lift the cutting machine and associated components some distance up from the base. By so doing, the bales may pass the cutting machine without being processed should this be desirable or required. Such a , movement of the cutting machine relative to the base may also be desirable or required to be able to carry out maintenance, repair and/or cleaning of the present apparatus .

In this context, the frame structure may be structures so as to be horizontally movable along a transport direction of the bales. This may prove useful for allowing the cutting machine to be moved away from the cutting area of the apparatus, for example past a dump edge or dump ramp for cut-up bales arranged in association with the base of the receiving station.

As an alternative or addition, the shafts may be structured so as to be horizontally movable along the frame structure and between the two sidewalls of the receiving station. Furthermore, the cutting machine may be structured so as to be horizontally movable relative to the frame structure. By so doing, the distance between the shafts and the sidewalls of the receiving station, possibly the distance between two or more shafts, may be adapted to the size(s) of the bales to be processed by means of the cutting elements on the shafts. This may prove useful when a large variation in size and/or shape of the bales exists. It is particularly the smallest bale size that will be the determining factor in this context .

As a further alternative or addition, the frame structure may be disposed above the cutting devices of the shafts and/or downstream of the cutting devices of the shafts. This may- prove useful for optimizing the placement of the shafts relative to the frame structure and/or other structural elements in vicinity of the present apparatus, for example in a building within which the apparatus is located.

As a further alternative or addition, the base of the receiving station may be structured to be movable for transport of the bales in a transport direction thereof, which constitutes a conveyor mechanism for the bales.

For example, this base may be comprised of a so-called walking floor or at conveyor belt .

As an alternative, the base of the receiving station may be arranged so as to slant downwards in a transport direction of the bales for gravitation-assisted transport thereof.

Yet further, at least one of the two sidewalls of the receiving station may be arranged so as to slant downwards and in towards the cutting devices of the shafts for gravitation-assisted feeding of the bales in the direction of the cutting devices.

As an alternative or addition, the sidewalls may be structured so as to taper in the transport direction of the bales for transport-assisted feeding of the bales in the direction of the cutting devices of the shafts. In this context, at least one of the sidewalls may be provided with a wedge-shaped guiding element projecting into the receiving station so as to taper it in the transport direction of the bales.

As a further alternative or addition, the receiving station may be provided with a push device for feeding the bales in the direction of the cutting devices of the shafts. Also this constitutes a conveyor mechanism for the bales. Such a push device may comprise one or several push plates or similar connected to a driving piston in an associated cylinder.

Yet further, each of the transverse cutting devices on the shafts may be comprised of a disc-shaped element disposed about the respective shaft;

- wherein said at least one cutting element is disposed at the periphery of the disc-shaped element.

In one embodiment, each cutting device may be comprised of a disc, the periphery of which has, at least partially, a knife edge shape .

In a second embodiment, each cutting device may be comprised of a disc, the periphery of which is provided, at least partially, with cutting teeth.

In a third embodiment, each cutting device may be comprised of a star-shaped disc structured with radially extending segments;

- wherein each segment is provided with at least one cutting element disposed at the periphery of the segment.

Said cutting element may thus comprise at least one cutting face, and this cutting face may comprise cutting teeth, for example .

This cutting element may also be releasably structured, whereby the cutting element is replaceable. As an alternative or addition, the cutting machine may comprise at least one scraper device disposed in vicinity of the cutting elements of the cutting devices for removing bale packaging from the cutting elements .

For example, the scraper device may thus be comprised of a scraper plate for said cutting elements.

Advantageously, the distance of the shafts to the sidewalls, as well as the distance between the shafts, may also be smaller than the transverse dimension of the smallest bale to be cut by means of the cutting devices of the cutting machine .

In a second aspect of the invention, a method for cutting of packaged bales is provided. The distinctive characteristic of the method is that it comprises the following steps: - using an apparatus according to the first aspect of the present invention;

- introducing the packaged bales into the receiving station of the apparatus for contact with the shafts and the cutting devices of the cutting machine; - rotating the shafts and their cutting devices whilst conveying the bales onwards to the shafts and the cutting devices for cutting of bale packaging and liberation of the contents of the bales; and

- transporting the cut-up bales onwards in a transport direction thereof.

According to an advantageous embodiment of the present method, packaged bales are introduced in a random position or pattern into the receiving station of the apparatus for contact with the shafts and the cutting devices of the cutting machine. Thereby, a controlled alignment or arrangement of the bales for onwards conveyance of the bales is avoided _/ cf . the preceding comments concerning this.

Hereinafter, a non-limiting, exemplary embodiment of the present apparatus will be shown.

Short description of the figures of the exemplary embodiment Figure 1 shows a perspective drawing of an apparatus according to the invention when placed in a remote heating plant, wherein the apparatus is shown before introducing packaged bales for cutting into pieces in the apparatus;

Figure 2 shows a perspective drawing of an apparatus according to figure 1, but wherein the apparatus is shown after having introduced packaged bales for cutting into pieces in the apparatus;

Figures 3, 4 and 5 show a respective front elevation, side elevation and base view of the apparatus according to figures 1 and 2; and

Figure b shows, in larger scale, details of the cutting devices and associated cutting elements of a cutting machine in said apparatus .

In order to facilitate the understanding of the invention, the figures are depicted somewhat distorted and show only the most essential components and elements of the present apparatus. The shapes, relative dimensions and mutual positions of the components and elements may also be somewhat distorted. Hereinafter, identical, equivalent or corresponding details in the figures will be given substantially the same reference numerals.

Specific description of the exemplary embodiment

Figures 1-6 show different views of an apparatus 2 according to the invention when placed in a remote heating plant (not shown) within which combustible material is burned on a large scale. The apparatus 2 is structured for cutting of packaged bales 4 (cf . figure 2) containing waste, textiles, straw and/or other combustible materials. In this embodiment, the bales 4 are packaged in shrink plastic wrapping to be cut in to pieces in the apparatus 2.

According to this embodiment of the invention, the apparatus 2 comprises the following components:

- a receiving station 6 defined by a so-called walking floor 8 (base) and two sidewalls 10, 10' disposed at a distance from each other;

- a cutting machine 12 comprising two rotatable, parallel and vertical shafts 14, 14' provided with several transverse cutting devices (cf . the subsequent description thereof) for cutting of the packaging on the bales 4 _/ and

- a supporting and vertically movable frame 16 disposed above the base 8 and connected to the cutting machine 12.

The two vertical shafts 14, 14' project down into the receiving station 6 and are supported in the frame 16, via respective electric motors 18, 18', only at their upper ends. The electric motors 18, 18' are structured for rotation and operational control of the shafts 14, 14 '. Moreover, the lower ends of the shafts 14, 14' are suspended freely above the walking floor 8. Further, the shafts 14, 14' are disposed at a distance from each other and at a distance from the sidewalls 10, 10' of the receiving station 6. Each shaft 14, 14' is provided with several transverse cutting devices in the form of star-shaped cutting discs 20 disposed at a vertical distance from each other along the respective shaft 14, 14'. In addition, each cutting disc 20 comprises several cutting elements structured in a manner allowing them to cut through packaging on the bales 4 upon rotation of the shafts 14 , 14 ' .

Each cutting disc 20 surrounds its associated shaft 14, 14' and is formed with radially extending and asymmetric segments 22 which, when viewed collectively, provide the cutting disc 20 with a star-shape (cf . figs. 1, 2, 5 and 6) . At the periphery thereof, each asymmetric segment 22 is provided with a cutting element in the form of a block-shaped cutting shear 24 (cf. figure 6), which also projects in a radial direction. The cutting shear 24 comprises a cutting face provided herein with two rows of cutting teeth 26 facing out into the direction of rotation of the shaft 14, 14'. Thereby, the cutting teeth 26 will come into contact with the packaging and the contents of the bales 4 upon each shaft 14, 14' being rotated by its electric motor 18, 18'. In this embodiment, the two shafts 14, 14' are rotated in opposite directions for cutting of packaged bales 4. Moreover, each cutting shear 24 is releasably structured. Thereby, the cutting shear 24 may be replaced when required or desirable. Replacement of one or several cutting shears 24 may prove considerably faster and/or cheaper than to replace the entire cutting disc 20.

In order to remove bale packaging and/or bale contents having attached itself to the cutting shears 24 of the cutting disc 20, the cutting machine 12 also comprises several scraper plates 28 disposed in vicinity of the cutting shears 24. As such, a respective, vertical scraper beam 30, 30' is disposed for each shaft 14, 14', and at a fixed distance parallel thereto. On each scraper beam 30, 30', several U-shaped scraper plates 28 are disposed at a vertical distance from each other. At its lower end, each shaft 14, 14' is rotatably connected to the respective scraper beam 30, 30' via a bearing pedestal 32, 32' . Each cutting shear 24 is associated with an individual scraper plate 28. The scraper beams 30, 30' are disposed downstream of the shafts 14, 14', and they are attached to the frame 16 of the cutting machine 12. Each U-shaped scraper plate 28 comprises a slit opening 34 coinciding with a corresponding slit opening 36 formed in the respective scraper beam 30, 30'. Both slit openings 34, 36 are of a size and shape allowing the cutting shear 24 to pass through them with a small clearance. By so doing, the bale packaging and/or bale contents will be continuously scraped off the cutting shears 24 upon rotation of the shafts 14, 14' .

The frame 16, which is disposed in the above-mentioned manner above the cutting discs 20 of the shafts 14, 14', is vertically movable by virtue of its opposite ends being movably attached in respective, vertical linear guides 38, 38' fixed to respective supporting columns 40, 40'. These supporting columns 40, 40' constitute structural elements in the remote heating plant. Raising and lowering of the frame 16 (and thus the cutting machine 12) may be carried out by means of a winch 42 attached to a supporting beam 44 disposed between the supporting columns 40, 40' . Motive power for the electric motors 18, 18' is transmitted via a drag chain connection 46 attached to the supporting column 40, among other things. In this embodiment, the shafts 14, 14' are also structured so as to be horizontally movable along the frame 16 and between the two sidewalls 10, 10' of the receiving station 6.

Further, the walking floor 8 (which is prior art) represents a conveyor mechanism that transports the bales 4 through the receiving station 6 in a transport direction thereof. The packaging and the contents of the cut-up bales 4 (not shown) are conveyed onto a dump edge 48 arranged at a downstream end of the walking floor 8 (cf . figs. 4 and 5) . Then the packaging and the contents are guided onwards into the remote heating plant for burning therein (not shown in the figures) .

Yet further, the receiving station 6 is formed as a sunken bin/pit with respective ramps 50, 50' formed at the upper ends of the sidewalls 10, 10' . By so doing, several bales 4 may be dumped directly and randomly down onto the walking floor 8 from a transport means (not shown) placed on one of the ramps 50, 50', for example from a flatbed on a lorry. This may be carried out without having to carry out a controlled alignment or arrangement of the bales 4 before being introduced into the receiving station 6. Thereby, the bales 4 assume a random position on the walking floor 8, as shown in figure 2.

Moreover, the one sidewall 10 of the receiving station 6 is arranged so as to slant downwards and in towards the star- shaped cutting discs 20 of the shafts 14, 14' for gravitation-assisted feeding of the bales 4 in the direction of the cutting discs 20. In addition, the slanting sidewall 10 is structured so as to taper in the transport direction of the bales 4. Thereby, it is possible to carry out a transport-assisted feeding of the bales 4 in the direction of the cutting discs 20 of the shafts 14, 14 '. For this purpose, the sidewall 10 is provided with a wedge-shaped guiding element 52 projecting into the receiving station 6 so as to taper it in the transport direction of the bales 4.

Figure 2 also shows that the distances of the shafts 14, 14' to the sidewalls 10, 10', as well as the distance between the shafts 14, 14', is smaller than the transverse dimension of the smallest bale 4 shown in the figure. This ensures that all packaged bales 4 come into contact with a cutting disc 20. Such a placement of the shafts 14, 14' also ensures that the complete periphery of a cutting disc 20 can come into contact with the bale packaging. By so doing, all cutting discs 20 and cutting shears 24 _, can also come into very good contact with the bales 4 for very efficient disintegration of their packaging, possibly also for efficient digging into the bales 4 for disengagement and/or disintegration of the contents thereof .

Structured in this manner, the shafts 14, 14' and their cutting discs 20 will function as beaters efficiently cutting up, tearing apart and kneading the packaging and contents of the bales 4. This is a substantially different principle of operation than that utilized for the above-mentioned, known methods and equipment for cutting of packaged bales.