WO2011049518A1

WO2011049518A1 - Arrangement for de-strapping of coils

Info

Publication number: WO2011049518A1
Application number: PCT/SE2010/051120
Authority: WO
Inventors: Mats Eriksson
Original assignee: Bergs Engineering Ab
Priority date: 2009-10-19
Filing date: 2010-10-18
Publication date: 2011-04-28
Also published as: EP2490951A4; EP2490951A1; WO2011049489A1

Abstract

A de-strapper (1) arrangement for cutting and disposing of a plurality of straps provided on and securing a coil of coilable material, comprises a pressure arrangement (2) adapted for maintaining the straps in position against the coil during a cutting operation, a cutting arrangement (3) adapted for maintaining the straps in position against the coil and for cutting the straps in a single motion, and a disposing (4) arrangement for removing the cut straps and disposing thereof.

Description

ARRANGEMENT FOR DE-STRAPPING OF COILS

TECHNICAL FIELD

The present invention relates to coiled materials in general, and particularly to arrangements for removing binding materials such as straps fitted around the circumference of such coils.

BACKGROUND

In the steel industry in particular, coils of materials are handled in large quantities. These coils are typically provided with binding materials, such as straps, securing the coiled material during storage or transportation to and from various locations within and without an industrial facility. These straps are typically manufactured from metal, and need to be removed in order to uncoil the material of the coil. Typically, an operator removes the straps manually. During a cutting process e.g. de-strapping process, the straps are very likely to spring back in an uncontrolled manner, thus potentially injuring an operator or surrounding machinery. In particular, with coils of large diameters, the straps might be as long as 7 meters. This causes problems when disposing of the straps.

Known automated solutions typically disclose a robot, which locates and cuts each strap individually.

Both the above-mentioned manual and automatic methods suffer from the need to perform a separate de-strapping maneuver for each strap. This requires each strap to be located and cut, which is time consuming.

Therefore, there is a need for an automatic de- strapping method and arrangement that overcomes the above-mentioned disadvantages. SUMMARY

The present invention provides an improved de-strapping arrangement.

Basically, a de- strapper 1 arrangement for cutting and disposing of a plurality of straps provided on and securing a coil of coilable material, comprises a pressure arrangement 2 adapted for maintaining the straps in position against the coil during a cutting operation, a cutting arrangement 3 adapted for maintaining the straps in position against the coil and for cutting the straps in a single motion. Additionally, the arrangement comprises a disposing arrangement 4 for removing the cut straps and disposing thereof.

Advantages of the present invention include:

A de-strapper with improved safety.

A de-strapper which is time saving.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further objects and advantages thereof, may best be understood by referring to the following description taken together with the accompanying drawings, in which:

Fig. 1 is a schematic illustration of a coil with straps;

Fig. 2 is a schematic illustration of an embodiment of the present invention;

Fig. 3 is a schematic illustration of a further embodiment of the present invention.

Figs. 4a-h is an illustration of the operation of a particular embodiment of an arrangement according to the present invention;

Fig. 5 is a schematic illustration of an embodiment of the present invention; Fig. 6a is a schematic illustration of an embodiment according to the present invention;

Fig. 6b is a schematic illustration of a further embodiment according to the present invention.

DETAILED DESCRIPTION

The present disclosure will be described in the context of handling of steel coils; however, it is equally applicable to other materials packaged in the same manner e.g. polymer, paper, cardboard.

Consider the situation where a coil of coilable material such as steel is provided with a plurality of straps. The straps are typically arranged (see Fig. 1) circumferentially along the length of the axis of the coil to prevent the coil from uncoiling during transport. At some point in time, the straps need to be removed and disposed of. This is an operation that takes time and can involve a hazard to the operator. The straps are typically made of some type of metal. After cutting, the strap can potentially recoil and result in a long strip of metal with sharp ends that needs to be disposed of. One problem is that the strap might be trapped in surrounding machinery or objects; also, the strap is difficult to handle in any efficient way. For a typical coil, there are at least three straps that need to be cut and disposed off.

The present invention discloses an automated de-strapping arrangement for cutting and disposing of straps binding a coil. According to the present invention, the de-strapping arrangement enables cutting all straps in a single operation, without the need of locating each individual strap prior to cutting. Subsequently, each cut strap is compacted and disposed in a space saving manner, typically coiled into individual tight coils. With reference to Fig. 2, a basic schematic principle of operation of an embodiment of a de-strapper arrangement 1 according to the present invention will be described. The de-strapper arrangement 1 comprises a pressure arrangement 2 adapted for maintaining the straps (not shown) in position against the outer circumference of the coil, a cutting arrangement 3 adapted for maintaining the straps in position against the coil and for cutting the straps in a single operation, and a disposing 4 arrangement for removing the cut straps and disposing thereof.

The cutting arrangement 3 is adapted for performing said cutting motion along and in parallel with a central axis of the coil. Preferably, the de- strapper arrangement 1 is configured to extend along substantially the entire length of the coil, or at least far enough to engage all of the plurality of straps on the coil. During operation, the de-strapper 1 is brought from a neutral position to an operating position to bring the pressure arrangement 2 and the cutting arrangement 3 into contact with the straps on outer surface of the coil. This is performed either simultaneously or sequentially. According to a specific embodiment, the pressure arrangement 2 is adapted to enable engaging and feeding the cut straps to the disposing arrangement. This is preferably enabled by means of a difference in the friction between the coil and the straps, and the friction between the straps and the pressure arrangement 2.

During the cutting operation, the cutting motion i.e. cutting depth of the arrangement is configured based on the thickness of the straps, in order to prevent damage to the underlying coil. However, since it is very difficult to prevent any damage at all, it is preferable to arrange the cutting motion such that the amount of damage is limited to as small area as possible. In essence, to reduce the amount of material that needs to be removed from the coil. Consequently, the coil is preferably oriented relative the de-strapper arrangement 1 such that the cutting operation is performed near the end of the coiled material, whereby only a short length of the coiled material needs to be discarded during a subsequent trimming operation.

For a general case, with reference to Fig. 3, the coil is arranged on well- known floor rollers or elevated rollers or supports, thus enabling rotating the coil to position the end of the coiled material in the proper position relative the de-strapper 1. For material with a high spring factor, it is preferable that a pressure or holding roll is provided on a top surface of the coil. If no floor rollers are provided, some other positioning means have to be applied to proper position the end of the coil relative the de-strapper arrangement. According to the embodiment of Fig. 3, the pressure arrangement 2 is configured with two individual but connected rollers 2a, 2b. In addition, the cutting arrangement 3 is configured as a guiding ruler 3a and a cutting blade 3b configured to move along the guiding ruler during a cutting operation.

Preferably, the pressure, holding and disposing arrangements are all pivo tally arranged relative a common pivot point, indicated by x in Fig. 3. A particular embodiment and the workings thereof will be described with reference to Fig. 4a-h.

Fig. 4a shows a coil of a coilable material, e.g. steel, provided on a rolling arrangement e.g. floor rollers, and a pressure roller mounted on top. The coil additionally comprises a plurality of circumferentially arranged straps, not shown in the image. The coil is further arranged such that the end of the coiled material is in a preferred starting position relative a de- strapper arrangement 1. The de- strapper arrangement 1 , illustrated in a neutral position, comprises a pressure arrangement 2 in the form of a pair of rollers 2a, 2b including a driven pressure roller 2a and a pressure roller 2b with a back stop (only allowing the pressure roller 2b to rotate in one direction), a cutting arrangement 3 in the form of a ruler or guiding means 3a in combination with a cutting blade 3b e.g. saw blade or similar. In addition, the de-strapper arrangement 1 comprises a strap disposing unit 4 e.g. caliper rollers for disposing the cut straps. Finally, the de-strapper 1 is pivotally arranged relative a pivot point, illustrated with a cross in the Fig. 4a. The de-strapping arrangement 1 is arranged such that a cutting motion is enabled along and in parallel with the rotational axis of the coil.

Upon activation of the de-strapper arrangement 1 according o the present invention, with reference to Fig. 4b, the de-strapper 1 is pivoted relative the pivot point in order to bring the ruler 3a and cutting blade 3b of the cutting arrangement 3 and the pair of pressure rollers 2a, 2b of the pressure arrangement 2 into contact with the plurality of straps and potentially also the surface of the coil. Preferably, the end of the coiled material has been oriented such that the ruler 3a and cutting blade 3b are in contact with the straps at a distance of D from the end of the coiled material. When the de- strapper 1 is in contact with the straps and coil, the cutting blade 3b is activated and moved along the length of the coil, guided by the ruler 3a and cutting any strap it intercepts. The ruler 3a of the cutting arrangement 3 and the pressure rollers 2a, 2b of the pressure arrangement 2 together act to ensure that the end of the coiled material and the ends of the cut straps do not spring back during or after the cutting operation.

When the cutting operation is finished, with reference to Fig. 4c, the cutting blade 3b is returned to a neutral or starting position along the ruler 3a. The ruler 3a is maintained in contact with the straps to prevent them from moving. The driven pressure roller 2a is activated and rotated such that an upper cut end of each strap is bent and fed out between the pressure rollers 2a, 2b. The term upper cut end is used with reference to the orientation of the coil and de-strapper arrangement as illustrated in Fig, 4c. The other pressure roller 2b prevents any other motion of the strap ends. Fig. 4d shows the coil and de- strapper 1 where the upper cut ends of the straps have been fed out a distance between the two pressure rollers 2a, 2b. An aspect of the pressure arrangement 2 concerns how to enable engaging and feeding the cut strap between the two rollers 2a, 2b. According to a preferred embodiment, the material of the driven pressure roller 2a is selected such that a friction force between the surface of the driven pressure roller 2a and the surfaces of the straps is larger than a corresponding friction force between the surfaces of the straps and the outer circumferential surface of the coiled material. When the driven pressure roller 2a is activated (after the straps are cut) its rotational motion in cooperation with the friction as described above, will cause the cut strap ends to slide on the circumference of the coil. Since the second pressure roller 2b is only allowed to rotate in one direction, it will act as a brake or block that prevents the end of the cut straps to pass. Instead the end of the cut straps will be forced to form a loop between the two pressure rollers 2a, 2b which will eventually cause the end to be dislocated from the coil and pass between the two pressure rollers 2a, 2b This enables the driven pressure roller 2a to interact with the strap in order to and force the cut strap to form the illustrated loop, which will subsequently force the upper cut strap end out between the two rollers 2a, 2b.

Subsequently, with reference to Fig. 4e, the coil is rotated such that the other end e.g. lower end (in correspondence with the use of the term upper cut end) of each strap e.g. the end engaged by the cutting arrangement is loosened from in between the coil and the floor rollers. Thus, the straps are merely suspended over the top of the coil and in contact with the pressure rollers 2a, 2b. As is shown in Fig. 4e, the de-strapper 1 has been moved out of contact with the coil by pivoting relative the pivot point. The pressure rollers 2a, 2b are moved into contact with each other to engage and feed the cut straps between each other. The driven pressure roller 2a thus provides a rotational motion also to the other pressure roller 2b (as indicated by the arrows) .

With reference to Fig. 4f, the pressure roller on top of the coil is brought out from the coil to enable the cut straps to be freely moved across the top of the coil. The pressure rollers 2a, 2b of the de-strapper arrangement 1 are operated until the ends of the cut straps are engaged by the disposing or coiler arrangement 4. With reference to Fig. 4g, when the ends of the cut straps have been engaged by the disposing arrangement 4, the pressure rollers 2a, 2b of the de- strapper 1 are separated or arranged to merely provide a guide to the cut straps, while the disposing arrangement 4 coils the straps into compact strap coils. Preferably, the disposing arrangement 4 is arranged to drop the compact strap coils into a container after the entire cut straps are coiled.

Finally, with reference to Fig. 4h, the coil is returned to its starting neutral position and is ready for further processing. The de-strapper arrangement 1 is brought out of contact with the coil and into a neutral position, ready for a subsequent coil to be processed.

According to a further embodiment of an arrangement according to the present invention, the disposing or coiler arrangement 4 can be replaced with some other arrangement suitable for disposing of the cut straps in an efficient way. One potential solution is to utilize a further cutting arrangement, which cuts or clips the straps into small pieces during the feeding operation of Fig. 4f-4g. In another embodiment, the disposing arrangement 4 comprises a shredder for cutting the straps into smaller sections.

A particular embodiment of a de- strapper arrangement 1 according to the present invention is illustrated in Fig. 5. In this particular embodiment, the de-strapper arrangement 1 is mounted on an elevated coil holder. In addition to the previously disclosed arrangements, the embodiment indicates driving means D l , D2, D3 adapted to enable the various parts of the arrangement to operate and move relative each other and the coil. These driving means can be configured to be pneumatic, hydro mechanical, electromechanical or equivalent. They can also comprise controlling means adapted for controlling the operation of the arrangement in dependence on at least a thickness of the straps. The arrangement of the present disclosure is particularly suitable for handling of straps on large coils with a diameter of 1000-2200 mm. However, it is equally applicable to smaller or larger diameters as well. The present invention enables de-strapping a coil in a single operation. In addition, the arrangement enables handling and compacting the cut straps into compact coils that are easily disposed of.

The arrangement is described as being floor mounted. However, it is easily adapted to be mounted from the ceiling, a wall, or as an integrated part of a coiler or other machinery.

The rollers of the de-strapper arrangement 1 are preferably manufactured from a material that is able to provide enough surface friction relative the straps to enable feeding the cut straps. Potential selection of material of the rollers is rubber, polyurethane, fleece (3M, Wohler) etc.

With reference to FIG. 6, a further embodiment of a cutting arrangement 3 according to the present invention will be described. Fig. 6a illustrates a situation in which the previously described embodiments of the present invention are advantageous. In this case, the coil surface is even and the outer surface of the shown strap is clearly extending at a larger radial distance from the central axis of the coir than the actual outer surface of the coil itself. This is shown in an ideal manner as being true along the entire length of the coil

However, for some instances or situations, the coil or e.g. the outer surface of the coil to be processed can be very uneven, this is illustrated in Fig. 6b. In this case, the outer surface of the coil describes a non-straight curve, resulting in the outer surface of the coil at some distance from the strap actually extending at a larger radial distance from the central axis of the coil than the outer surface of the strap. Therefore, and in even more extreme cases with a plurality of straps, the uneven surface e.g. undulating surface of the coil may be large enough to prevent a strap to be cut during a cutting operation. Alternatively, in another example, the set cutting depth that is enough to enable the cutting blade 3b to cut a strap safely will at some sections of the coil actually result in the cutting blade 3b unintentionally cutting the coil itself. More specifically, the outer surface of the coil may extend further in a radial direction of the axis of the coil than the straps holding the coil together. In other words, the outer surface of the coil may have an undulating shape. In order to prevent this, the previous embodiments of the present disclosure would need to be configured with a larger cutting depth, which would in turn result in a greater risk of damaging an inner layer of the coil and thereby scrapping a larger portion of the coiled material than necessary.

To overcome the above-mentioned difficulty, in a particular embodiment of the present invention and with reference to Fig. 6b, the cutting arrangement 3 is configured to have a dynamically adaptable cutting depth. The cutting arrangement is configured to adapt its cutting depth dynamically and automatically during a cutting operation. In other words, the cutting arrangement 3 is configured to be able to compensate or adjust in response to an uneven outer surface of a coil to be processed.

The cutting arrangement 3 is consequently configured to be able to move parallel to the axis of the coil (as shown previously), and in addition to be able to move in a radial direction relative the axis of the coil e.g. perpendicular to the coil outer surface during a cutting process. The distance between the outer surface of the coil and the cutting blade 3b is determined or controlled by a roller arrangement 3c which during a cutting operation is maintained in contact with the outer surface of the coil. In addition, the cutting arrangement 3 includes a further roller arrangement 3d, which is configured to prevent the cutting blade from cutting into the coil after passing and cutting a strap, which is located at a shorter radial distance from the coil axis than the subsequent outer surface of the coil. The two roller arrangements 3c, 3d are preferably rigidly attached to the cutting blade 3b, and adjustably attached to the cutting arrangement 3. However, it is possible to have a non-rigid or variable attachment between the two roller arrangements 3c, 3d and the cutting blade 3b. The force with which the two roller arrangements 3c, 3d are kept in contact with the outer surface of the coil is determined by springs, pneumatics or hydraulics or a combination thereof. Although two roller arrangements 3c, 3d are described, it is possible to implement some other mechanical means to enable the same action. It is also possible to configure the two rollers as one single unit in the cutting arrangement 3. The embodiments described above are to be understood as a few illustrative examples of the present invention. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. The scope of the present invention is, however, defined by the appended claims.

Claims

1. A de-strapper (1) for cutting and disposing of a plurality of straps provided on and securing a coil of coilable material, characterized by

-a pressure arrangement (2) adapted for maintaining the straps in position against the coil during cutting operation,

-a cutting arrangement (3) adapted for maintaining the straps in position against the coil and for cutting the straps in a single motion,

-a disposing (4) arrangement for removing the cut straps and disposing thereof.

2. The arrangement according to claim 1, characterized by said pressure arrangement comprising at least two pressure rollers (2a, 2b) adapted to be brought into contact with said coil by means of a pivotal motion relative a common pivot point (x) .

3. The arrangement according to claim 1, characterized by said cutting arrangement comprising a guide (3a) and a cutting blade (3b).

4. The arrangement according to claim 3, characterized in that said guide (3a) is arranged to be brought into contact with the plurality of straps and act as a guide for said cutting blade (3b) during a cutting operation.

5. The arrangement according to claim 3, characterized in that said cutting blade (3b) is configured to be moveable along and in parallel with a central axis of said coil to enable said cutting operation.

6. The arrangement according to claim 1, characterized in that said disposing arrangement (4) comprises a coiling arrangement adapted to receive a cut end of each cut strap and to coil said straps into coils.

7. The arrangement according to claim 1, characterized in that said disposing arrangement (4) comprises a cutting arrangement adapted to receive and cut each strap into smaller sections after the cutting operation.

8. The arrangement according to claim 3, characterized in that said guide (3a) is adapted to engage the coil and straps at a predetermined position relative an end of the coiled material on the periphery of the coil.

9. The arrangement according to claim 2, characterized in that said cutting arrangement (3) and said disposing arrangement (4) are both configured to perform a pivotal motion relative said common pivot point.

10. The arrangement according to claim 2, characterized in that said two rollers (2a, 2b) comprise a driven roller (2a), and a roller only able to rotate in a single direction (2b).

1 1. The arrangement according to claim 10, characterized in that said two rollers (2a, 2b) are configured to cooperated to engage and feed a cut end of each strap between each other.

12. The arrangement according to claim 1 1, characterized in that the material of at least the driven roller (2 a) is selected to provide a friction force between the driven roller (2a) and the cut strap that is larger than a friction force between the cut strap and the outer circumferential surface of the coil.

13. The arrangement according to claim 5, characterized in that said cutting blade (3b) is further configured to be moveable in a direction perpendicular to the outer surface of the coil during a cutting operation.

14. The arrangement according to claim 13, characterized in that said cutting arrangement (3) further comprises a first roller arrangement (3c) connected to said cutting blade (3b), said roller arrangement (3c) is configured to maintain a predetermined distance between the cutting blade (3b) and said outer surface of the coil during a cutting operation.

15. The arrangement according to claim 13-14, characterized in that said cutting arrangement (3) further comprises a second roller arrangement (3d) connected to said cutting blade (3b), said second roller arrangement (3d) is configured to prevent said cutting blade (3b) from cutting into the outer surface of the coil after cutting a strap.

16. The arrangement according to any of claims 14- 15, characterized in that said first and/ or second roller arrangement (3c, 3d) are rigidly connected to said cutting blade (3b).

17. The arrangement according to any of claims 14- 16, characterized in that said first and/ or second roller arrangements (3c, 3d) are adjustably connected to said cutting arrangement (3).

18. The arrangement according to claim 17, characterized in that said first and/ or second roller arrangements (3c, 3d) are connected with said cutting arrangements (3) with one or a combination of springs, pneumatics, hydraulics.