EP2121453A1

EP2121453A1 - Bale tongs to be connected to a working machine

Info

Publication number: EP2121453A1
Application number: EP07858346A
Authority: EP
Inventors: Kalle Pohjola
Original assignee: Rannikon Konetekniikka Oy
Current assignee: Rannikon Konetekniikka Oy
Priority date: 2006-12-15
Filing date: 2007-12-14
Publication date: 2009-11-25
Also published as: FI20065813A0; UA94490C2; WO2008071856A1; RU2009125204A; FI20065813L

Abstract

The invention relates to bale tongs comprised of a mounting member (10) for coupling to a working machine and of grabbers (12a and 12b) for gripping a bale as well as of a cutting structure (19) for cutting the tying material of the bale. It also has spike-like gripping members (14a and 14b). These gripping members move from their idle position to an extreme position and back. In their extreme position, the gripping members have penetrated the bale held by the tongs and the tying material of the bale with the result that a part of the tying material is left between the gripping member and the grabber. When the gripping members retract from the extreme position to the idle position, the tying material of the bale left between the gripping member and the grabber is released. A cutting structure is fixed to the mounting member of the bale tongs, between the grabbers. This cutting structure cuts the bale held by the grabbers and the tying material thereof. The bale held by the grabbers is unpacked by moving the gripping members from the idle position towards the extreme position to make them penetrate into the bale and the tying material thereof. The bale and the tying material are cut by the cutting structure. The cutting is continued until the baled material starts to disintegrate. After the bale has become empty, the tying material is left hanging from the grabbers and the gripping members. The tying material is removed from the bale tongs by retracting the gripping members from the extreme position to the idle position, thus causing the tying material to drop down. Due to the invention, the tying material and the contents of the bale can easily be separated and discharged at their own places.

Description

Bale tongs to be connected to a working machine

The invention relates to bale tongs to be connected to a working machine, such as a forklift truck, wheel loader or crane, having a mounting member for coupling to the working machine and grabbers for gripping a bale, which grabbers are movable towards and away from each other, as well as a cutting structure for cutting the tying material of the bale.

Generally, bales are made by bringing the material to be handled to a press, whereafter the bale is wrapped in wrapping material, usually plastic, and tied into shape by means of tying wires or bands. The tying wires usually consist of metal or plastic. A packed bale is easier to handle and transport. At the destination, it is usually desirable to separate the contents of the bale from the tying material. Several solutions have been developed for opening a bale. It can be opened manually, but this is slow and involves an increased employment accident risk. Separate unbalers are also known. These unbalers are usually large, complex, expensive and fixedly mounted. Besides, the use of such an apparatus adds an additional time-consuming working step to the bale handling. Often it would also be preferable to be able to discharge and leave the contents and tying material of the bale, respectively, in their own places in a controlled way, but these methods do not allow this.

The known bale movers, which usually are coupled to forklift trucks or similar working machines, are used for stacking bales, lifting them away from stacks or vehicles and for conveying them to a place where the contents of the bale are to be discharged. The handling of bales would be faster if the unpacking of them and the removal of the tying material were performed by this bale mover attached to a working machine.

Patent publication US 6,200,084 B1 describes an apparatus resembling tongs which is attachable to a forklift truck and cuts the tying wires of a bale by means of knives included in the tongs. This solution does not enable moving bales, and the wires that have been cut must be collected in a separate working step. In patent publication US 5,445,490, a bale holder having movable and retractable knives, which cut the tying wires, in holder arms, is coupled to a working machine. The tying wires are left on a gripping device included in the holder. This solution is not capable of handling bale-wrapping material and is not applicable to a case where the whole bale structure is to be disintegrated. Patent publication WO 92/05103 combines two pairs of bale-compressing tongs with a tie wire cutting knife directed from a forklift truck towards the bale. This structure makes it possible to drop the tying wires, which have been cut off, in a different place than the opened bale. However, this solution does not remove the bale-wrapping material either. In patent publications US 5,445,490 and WO 92/05103, the bale contents must be quite light and hold together well.

The objective of the invention is to provide novel bale tongs which enable a considerable alleviation of the drawbacks and disadvantages related to the known art.

The objectives of the invention are achieved by means of bale tongs which are characterized in what is set forth in the independent claims. The dependent claims describe preferred embodiments of the invention.

The bale tongs according to the invention have a mounting member for coupling to a working machine, a first and a second grabber for gripping a bale, which grabbers are movable towards and away from each other, as well as a cutting structure for cutting the tying material of the bale. The invention is characterized in that it has at least one gripping member for gripping the bale held by the first and the second grabbers, and the tying material thereof.

In a preferred embodiment of the apparatus according to the invention, there are two gripping members, a first and a second gripping member, which are spike- shaped rods sharpened at one end.

In another preferred embodiment of the apparatus according to the invention, the first and the second gripping members are arranged to move from their idle position to an extreme position and back. In the extreme position, the first and the second gripping members have penetrated the bale held by the grabbers and the tying material of the bale with the result that a part of the tying material has been left between the first gripping member and the first grabber as well as between the second gripping member and the second grabber. As the first and the second gripping members are retracted from the extreme position to the idle position, the tying material left between the first gripping member and the first grabber as well as between the second gripping member and the second grabber are released. Preferably, the first and the second gripping members are arranged to move from the idle position to the extreme position in such a way that they penetrate the bale held by the first and the second grabbers diagonally. The drive force of the first and the second gripping members is produced by means of compressed air, hydraulics, a separate electric motor or another method. Usually they get their drive force from the working machine to which the bale tongs are attached.

A movable cutting structure is fixed to the mounting member of the bale tongs, between the first and the second grabbers. This cutting structure is arranged to cut the bale held by the grabbers and the tying material thereof. The cutting structure can be a one-bladed striking structure or a single- or multi-element cutting structure based on a sawing, shearing or cutting movement, depending on the bale type and the way that it is packed. Like the gripping members, this cutting structure gets its drive force from the vehicle.

The bale tongs according to the invention are especially useful for opening waste bales and for recovering the tying material thereof, but it is readily applicable to the handling of other kinds of packages or bales as well. As for waste bales, the contents are crushed waste to be incinerated, mainly plastic, paper and household waste. Waste bales are usually box-shaped and variable in size, depending on the baler. The bale size is usually approximately 100 cm x 100 cm x 120 to 150 cm (width, height, length). It also must be taken into account that a compressed bale tends to expand after coming out of the baler. The weight of a bale may vary between 400 and 2000 kg, generally between 800 and 1200 kg. A bale is tied with 3 to 5 tying wires made from steel or plastic. The tying wires extend around the bale either vertically or horizontally. Besides, the bale is wrapped in wrapping material made from PE plastic. The number of the wrapping material layers may vary. From here onwards, the bale wrapping material and tying wires will be called "the tying material" in this description.

Bales packed as described above generally are located at a distance from their handling site. A bale is fetched by gripping it by the first and the second grabbers of the bale tongs according to the invention and by taking it to the intended site which in the case of waste bales usually is an incineration plant and a conveyor belt feeding it. The bale is gripped in such a way that the tying wires extending around the bale lie transversely to the cutting structure. While the bale is held by the first and the second grabbers, the spike-shape first and second gripping members are moved from the idle position towards their extreme position so as to make them penetrate into the bale and the tying material thereof. After reaching the extreme position, the first gripping member has get the tying wires and a part of the wrapping material between itself and the first grabber. The situation is the same with the second gripping member and the second grabber, when the second gripping member is in its extreme position. Once the bale has been conveyed to the place where it is to be unpacked, the cutting structure is started. The cutting structure cuts the bale and the tying material thereof. Because the position of the bale has been chosen so as to position the tying wires transversely to the cutting edge, it is easy to cut them. After cutting the tying wires, the cutting is continued until the baled material begins to disintegrate. After the emptying of the bale, the tying material hangs from the first and the second grabbers and the gripping members. The tying material can be taken to its own storing place where it is removed from the bale tongs by retracting the first and the second gripping members from the extreme position to the idle position, as a result of which the tying material drops down.

An advantage of the invention is that it makes it easy both to open a bale wrapped in wrapping material and to separate the contents of the bale and the tying material thereof.

A further advantage of the invention is that it is simple, easy to use and reduces the number of necessary working steps. The whole bale handling process can be carried out by one employee. Besides, the reduced number of possible dangerous situations improves the occupational safety.

A further advantage of the invention is that it is useful in small, narrow spaces or spaces of different shape, and the use thereof is not place-bound. The invention is inexpensive to use compared to many other solutions dealing with the same problem since the latter require large plants.

In the following, the invention will be described in detail. In the description reference will be made to the accompanying drawings in which

Figure 1 is an exemplary side view of a preferred embodiment of the bale tongs according to the invention, and

Figure 2 is an exemplary top view of a preferred embodiment of the bale tongs according to the invention.

Figure 1 and Figure 2 are an exemplary side view and a top view, respectively, of the bale tongs according to the invention. The bale tongs have a mounting member 10 for mounting to a forklift truck, tractor, lorry or the like. The mounting member is a flat structure. The bale tongs are provided with adapters and connection pieces (not shown in the Figure) by means of which it can be connected to the drive system of the working machine. The mounting member is attachable to a lifting device in the working machine, such as in a forklift truck, which can lift and lower the bale tongs.

The mounting member has a first and a second grabber 12a and 12b which are parallel, flat structures in an upright position. In the embodiment shown in Figures 1 and 2, the first and the second grabbers are made by forming a parallelogrammic body from a bent metal bar or tube and by mounting metal bars in the opening left in the middle of the body so as to obtain a latticework. The faces of the grabbers which will be in contact with the object to be moved can be indented, roughened or treated in another way to improve the grip.

The edges of the first and the second grabbers 12a and 12b facing the mounting member 10 each comprise two fixedly mounted, sheet-like base parts, upper base parts 21a and 21 b as well as lower base parts 25a and 25b. The base part 25b is not shown in the Figures. The base parts are all elongated plates having a wider end and a narrower end, and they are set so that the narrower ends of the opposite base parts face each other and the side lying closer to the mounting member is parallel thereto. Both grabbers are fixed to the corner of the wider end of the upper and lower base parts located furthest away from the mounting member. The fixing is performed so that the long side of each base part located closer to the mounting member substantially forms a right angle with the fixed grabber.

Inner and outer articulated arms couple each base part 21a and 21 b as well as 25a and 25b to the mounting member 10. All of the articulated arms have the same shape. The outer articulated arms are located at the outer edges of the bale tongs. The upper outer articulated arms 30a and 30b are coupled to the upper base parts 21 a and 21 b, and the lower outer articulated arms 31a and 31 b are connected to the lower base parts 25a and 25b. The articulated arm 31b and the lower base part 25b are not shown in the Figures. From here onwards, when the outer articulated arms will mentioned, reference will made to both the upper and lower outer articulated arms. Like the outer articulated arms, the inner articulated arms couple each base part 21a and 21b as well as 25a and 25b to the mounting member 10. The inner articulated arms are disposed between the outer articulated arms. The upper inner articulated arms 32a and 32b are coupled to the upper base parts 21a and 21 b, and the lower inner articulated arms 33a and 33b are coupled to the lower base parts 25a and 25b. Neither of the articulated arms 33a and 33b is shown in the Figures. From here onwards, when the inner articulated arms will be mentioned, reference will be made to both the upper and lower inner articulated arms.

The outer articulated arms 30a and 30b as well as 31a and 31 b have their first ends connected, by means of an articulation structure, to the corner of the wider end of the base parts facing the mounting member. The inner articulated arms 32a and 32b as well as 33a and 33b have their first ends connected, by means of an articulation structure, to the narrower end of the base parts. Articulation structures connect all of the articulated arms, both the outer and inner ones, to the mounting member 10 at a point located substantially at a distance of one third of the length of the articulated arm from the second end of the articulated arm.

An upper and a lower connecting arm 35a and 35b connected together the inner articulated arms lying in the same plane. The connecting arm 35b is not shown in the Figures. Both connecting arms being arranged to operate in the same way, the operation of a connecting arm described later applies to both connecting arms. The connecting arm is an elongated, sheet-like metal structure. The connecting arm has its first end connected to the end of the inner articulated arm located closer to the working machine. The connecting arm has its second end connected to the inner articulated arm lying in the same plane, at a point substantially at a distance of one third of the length of the articulated arm from the one of its ends that is located farthest away from the working machine. The connections of the connecting arm are made by using articulation structures. The connecting arms serve to synchronize the articulated arms to move simultaneously in their opposite directions. The number of the connecting arms may vary.

The outer and inner articulated arms and the connecting arms connecting them form a grabber moving mechanism together with a separate actuator (the actuator is not shown in the Figures) by means of which the first and the second grabbers can be moved either towards or away from each other. Preferably, the actuator is a hydraulic cylinder mounted directly between the inner articulated arms, to the articulation structures facing the working machine. The moving mechanism is capable of moving the first and the second grabbers with such a force that a bale can be taken between the grabbers and held there. These are solutions known per se.

The first and the second gripping members 14a and 14b are metallic, bar-like structures. They are placed inside a first and a second hydraulic cylinder 17a and 17b. The first and the second gripping members have sharpened first ends 16a and 16b projecting out of the first and the second hydraulic cylinders. The second ends, not shown in the Figure, of the first and the second gripping members are located inside the first and the second hydraulic cylinders. The state in which they are inserted into the first and the second hydraulic cylinders, as far as it is structurally and functionally possible, is called the idle position of the first and the second gripping members. The second ends of the first and the second gripping members as well as the inner parts of the first and the second hydraulic cylinders are shaped so that the first and the second gripping members, when coming out of the first and the second hydraulic cylinders, stop at a given point. This state is called the extreme position. A first and a second joint 15a and 15b join the first and the second hydraulic cylinders 17a and 17b to the upper corners of the first and the second grabbers 12a and 12b facing the working machine. The first and the second hydraulic cylinders are set so that the first and the second gripping members lie in the gap defined by the first and the second grabbers. The first and the second hydraulic cylinders are positioned in such a way that, when the first and the second gripping members are in the extreme position, their first ends 16a and 16b are located close to the corners 18a and 18a formed by the body of the first and the second grabbers and located opposite to the connecting corners of the first and the second joints 15a and 15b. The corner 18b is not shown in the Figures. Then, the first and the second gripping members lie approximately parallel to the plane of the first and the second grabbers. The first and the second hydraulic cylinders are connected at their ends, via a first and a second adapter 13a and 13b, to the drive force system of the working machine by means of which the first and the second gripping members are moved like a piston. This drive force is usually obtained from the working machine hydraulically but compressed air solutions are also feasible.

A cutting structure is fixed to the mounting member, in the area between the first and the second grabbers. The cutting structure is an elongated, flat metal plate with a straight first longer side and an indented second longer side. The indented side comprises a slot with a cutting tool 40. The cutting tool is an elongated metal plate having its first longer side shaped to allow the cutting tool to move in the slot. The second longer side of the cutting tool is indented. The first end of the cutting structure 19 is provided with a motor 39 moving the cutting tool 40 back and forth in the slot. The motor gets its drive force from the working machine. At one end of the cutting structure, the slot is left open so as to allow the cutting tool to come out of the slot partly. During the movement of the cutting tool, the indentations of the cutting structure 19 and the cutting tool 40 slide past each other and cut the material remaining between the teeth. The indentations are suitably shaped for cutting the tying material of the bale held by the grabbers.

The cutting structure 19 is movably connected to the mounting member by arm members 37 and 38. The arm members are metal bars connected by an articulated structure to a first side of the cutting structure 19 at their first ends. The connecting points of the arm member 37 and the arm member 38 are located near the motor 39 and in the middle of the first side of the cutting structure, respectively. The second ends of the arm members are connected to the mounting member 10. The connecting points are located above one another in the middle of the mounting member, the upper arm member 37 and the lower arm member 38 thus being connected to mounting member at an upper and a lower point, respectively. The arm members allow the movement of the cutting structure that is substantially parallel to the plane of the grabbers. While the arm members are in their upper position, the cutting structure 19 is almost upright, lying near the mounting member. This state of the cutting structure is called the idle state. Then, the cutting structure does not interfere with the handling of the bales with the grabbers. The cutting structure can be moved towards and away from the bale by moving the arm members. The moving mechanism of the arm members, which is not shown in the Figures, gets its drive force from the working machine.

All of the above-mentioned movable mechanisms are controlled from the cabin of the working machine.

When the first and the second gripping members 14a and 14b as well as the cutting structure 19 are in their idle states, the bale tongs connected to the working machine can be used for stacking and transporting bales in a conventional manner. When the bale held by the bale tongs is to be unpacked, the first and the second gripping members are moved from their idle position to their extreme position. Then, the gripping members penetrate into the bale, and the tying wires as well as a part of the wrapping material are left pressed between the gripping and the grabber next to it. A suitable movement of the arm members 37 and 38 makes the cutting structure to move downward and forward. The cutting structure ends up below the bale. The cutting structure can be lifted from this position by means of the arm members to cut the bale and the tying material thereof. This goes on until the contents of the bale start to discharge and the bale becomes empty. The first and the second gripping members as well as the grabber keep the opened wrapping material and the cut tying wires on the bale tongs. They can be taken to a desired place by driving the working machine there and by moving the gripping members into their idle position in order to release and drop the tying material.

When there is firmly held bale wrapping material between the gripping members and the grabbers, the grabbers can be moved away from each other to tighten the wrapping material and thus to make the cutting easier for the cutting structure. Moreover, the emptying of the bale can be enhanced by moving the grabbers back and forth.

The foregoing describes specific preferred embodiments of the apparatus according to the invention. The invention is not restricted to the above-described solution but the inventive idea is applicable in many ways within the scope of the Claims.

Claims

1. Bale tongs to be connected to a working machine, such as a forklift truck, wheel loader or crane, having a mounting member (10) for coupling to the working machine and a first and a second grabber (12a, 12b) for gripping a bale, which grabbers are movable towards and away from each other, as well as a cutting structure (19) for cutting the tying material of the bale, characterized in that it also has two gripping members (14a, 14b) for gripping the wrapping material and/or tying wires of the bale held by the grabbers, of which gripping members the first gripping member is arranged in connection with the first grabber (12a) and the second gripping member is arranged in connection with the second grabber (12b). ,

2. Bale tongs according to Claim 1 , characterized in that the gripping members (14a, 14b) are arranged to move from their idle position to an extreme position and back, the gripping members thus being arranged to grip the wrapping material in their extreme position and to disengage from the wrapping material in their idle position.

3. Bale tongs according to any of Claims 1 to 2, characterized in that the gripping members (14a, 14b) are spike-shaped.

4. Bale tongs according to any of Claims 1 to 3, characterized in that the gripping members (14a, 14b) are arranged to penetrate into the bale when moving from the idle position to the extreme position.

5. Bale tongs according to any of Claims 1 to 4, characterized in that the gripping members (14a, 14b) are arranged to press a part of the tying material between the gripping member (14a, 14b) and the grabber (12a, 12b) when the gripping members are in their extreme position.

6. Bale tongs according to any of Claims 1 to 5, characterized in that the gripping members (14a, 14b) are arranged to release the bale tying material left between the gripping member (14a, 14b) and the grabber (12a, 12b) in their idle position.

7. Bale tongs according to Claim 1 , characterized in that the cutting structure (19) is fixed to the mounting member (10) to be movable in the area between the grabbers (12a, 12b).

8. Bale tongs according to Claim 7, characterized in that the cutting structure (19) has two indented parts of which one is unmovable and the other is movable (40).

9. Bale tongs according to Claims 7 and 8, characterized in that it has a motor (39) for moving the movable part (40) of the cutting structure (19).

10. Bale tongs according to any of Claims 7 to 9, characterized in that the indentations of the cutting structure (19) are arranged in such a way that the teeth of the opposite indentations cut the material left between them when the movable part (40) is moving.

11. Bale tongs according to any of Claims 7 to 10, characterized in that the cutting structure (19) is arranged to cut the tying material to cause the bale to disintegrate.

12. Bale tongs according to any of Claims 7 to 11 , characterized in that the cutting structure (19) is arranged to cut the bale from below upwards.