Description

Technical Field

[1 ] The invention relates to a spool for winding metal wire on having a stock, or reserve, or storage section. The invention also relates to a method for adapting a metal wire spool.

Background Art

[2] Within the metal wire industry wires are wound and unwound from spools all the time. Spools in the metal wire industry differ greatly from those in the textile industry. They have to carry metal wires with diameters up to 2 to 2.5mm. These metal wires are much heavier than wires in the textile industry and are hard to bend. Hence, the forces the metal wire spools have to sustain and the masses they carry are much bigger than in the textile industry. A textile spool is unsuitable to wind metal wire on unless the metal wire is thinner than 0.115 mm and a metal wire spool is not suitable to wind any textile wire on because its angular momentum of inertia is too high.

[3] Within the metal wire industry, to achieve a continuous process, it is necessary to connect the end of a wire on a second spool to the start of a wire on a first spool. For clarity, the ‘start of the wire’ is that wire end that is below the windings on the spool, the ‘end of the wire’ is that wire end that is on top of all windings. When now the first spool runs empty, the second spool will take over without having to interrupt the process. The advantage is obvious: the operator does not have to surveil the first spool running empty in order to timely connect the start of that first spool with the end of the second. The connection can be made in his own time, one after the other.

[4] It is thus necessary that the start of the wire remains reachable to the operator at all times. For the end of the wire this is not a problem, as this is situated on top of all windings. Normally this is achieved by the operator of the previous step that inserts the wire end in a hole in the flange rim that is situated at the outer circumference of the spool. Thereafter wire winding starts on the core till the spool is full. However, such a process is difficult to automate: first the flange has to be identified and the hole found. Then the start of the wire has to be inserted into the small hole.

[5] In another production situation, it may occur at the start-up of a processing line that the wire is defective because the installation is not yet in regime. This start-up wire needs to be separated from the wire that complies to specification. Nowadays this is done with a ‘scrap spool’. This is a small, separate spool, attached next to the production spool that is held on the same axis with the same end-fixture. When the production spool is full, the scrap spool is also removed, and the wire on the scrap spool discarded. Again, the use of such scrap spool inhibits automation of the system.

[6] In still another production situation it may be necessary to take intermediate samples when a line is in regime. Currently this must be done by the operator cutting the wire, taking a sample and winding the new end on the spool, while the line is running. This is a dangerous handling one wants to avoid. Again if this could be automated this would be a great benefit.

[7] In the prior art of US 4 796 830 a cable reel for storing copper cable is described. The cable reel includes a central drum member for winding cable thereon and flanges disposed at the opposite ends of the drum member. One of the flanges is split in a pair of members disposed spaced form each other thereby defining a volume beween them. The flange members are coupled to one another via a plurality of connecting dowels. The connecting dowels can also provide a means for retaining the end connections of the cable within the volume between the flange members and thus protect the wire end. However, in such an arrangement, the holding of the end connection of the cables needs securing by the operator: the connecting dowels will not retain the cable without leading it around or between the dowels. The inventors have therefore set themselves the task to find a solution to the problems arising in the above three situations. Further to that, one must take into account that thousands of spools are circulating in a production environment. Replacing all of those spools is not only a huge investment, but also requires a long time before all spools are replaced. For this the inventors propose a method to adapt an existing wire spool.

Disclosure of Invention

[8] The main objective of the invention is to provide a solution for the above mentioned problems. Auxiliary objects are to provide a spool that allows access to the start of the wire end, that has a reserve for scrap wire and that allows for easy sample taking. Another objective is to provide a spool that allows to automate processes. A still further objective is to provide a method to adapt existing spools to reach the foregoing objectives.

[9] A first aspect of the invention is as covered by the product claims directed to a metal wire spool. This metal wire spool is designed to keep metal wire, such as steel, copper, aluminium, or metal alloys of all kinds. The spools can hold metal wire up to a diameter of about 2.8 mm, with a capacity of up to one ton in mass. At the lower end, the inventive principles of the spool can also be used for very fine wire such as down to 150 pm, although this may necessity further changes. In any way the inventive principle can be used for wires down to 0.30 mm. The spools then have a capacity of more than 100 kg.

[10] The metal wire spool - in short ‘spool’ hereinafter - comprises a core having an axis, that is also the axis of the spool. The core is provided with a first and second flange, perpendicular to the mentioned axis. Preferably the flanges are circular and have a flange diameter. The separation between the first and second flange defines a width on the core. The second flange can be the left flange or the right flange when standing before the spool, this is immaterial to the invention.

[11 ] Characteristic of the spool is that it is provided with a third flange perpendicular to the axis of the core, and thus parallel to the first and second flange. A gap will thus form between the first and third flange. This gap or space between the first and the third flange must be smaller than half of the width, the axial distance between first and second flange. In this gap, between the first and third flange, ‘resilient retainers’ are mounted. These retainers are made ‘resilient’ meaning for the purpose of this application that they are elastic, springy and - after the metal wire has passed - return back to their original position to keep the metal wire in between the gap even if that metal wire would lose tension. These resilient retainers must keep the wire in between the first and third flange as wire is wound in between. More specifically, when the metal wire is being cut, the end must be held between the first and third flange. In order to prevent that the wire end would spring back these resilient retainers must keep the wire in the gap between the first and third flange. In any case the free wire end should not protrude out of the flange.

[12] The space between the first and third spool is therefore intended to be used as a reserve area, a ‘storage section’ to keep a limited amount of wire for example the start of the wire, sampled wire or scrap wire, hereinafter called ‘stock wire’. It follows that the gap in between the third and first spool should not be large preferably less than half the width or even less than a fifth, eighth, or even tenth of the width. Preferably this gap is somewhere between five times to fifty times the diameter of the thickest wire one intends to put on the spool.

[13] The third flange can take two positions close to the first flange.

In a first preferred embodiment, the third flange is mounted in between the first and second flange, at the side of, closer to said first flange. This implies that the capacity for storing production wire, the ‘workspace’, is between the second and third flange. As one tries to put as much metal wire as possible on a spool it follows that the gap between first and third flange, the storage section, is kept as small as possible.

[14] In a second preferred embodiment, the third flange is mounted outside said first and second flange, at the side of the first flange. The workspace is then between the first and second flange, the storage section - as always - between first and third flange.

[15] In a following preferred embodiment, the diameter of the third flange is equal or smaller than the diameter of the first and second flange. In this way the metal spool can still be rolled on the first and second flange, while the third flange is not hindering. Preferably the diameter of the third flange is more than the average of the core and first flange diameter. The third flange diameter should not be too small as otherwise the amount of stock wire that can be stored is too small and/or the storage section may be overrun with production wire.

[16] In a further preferred embodiment one or more radially oriented slots are provided in either the third flange (second-third-first flange arrangement) or first flange (second, first, third flange arrangement). This slot allows to switch the wire from workspace to storage section and vice versa without having to move the wire over the flange. The slots should be sufficiently wide to let the wire pass through for example the slots are between five and five hundred times the wire diameter.

[17] Preferably, the sides of slot in the flange - first or third - are provided with chamfered edges to better guide the wire. Also a number of slots can be provided that are chamfered such that the wire easily goes from workspace to storage section and the remaining slots are chamfered that prefer the wire going from storage section to the workspace. In this way the entry into the storage section is at a known entry slot as well as the exit out of the storage section is at a known exit slot.

[18] The slots can be radially straight, or the slots can be radially curved in the plane of the flange. The curving should be oriented forward to the intended running direction of the wire.

[19] In a next preferred embodiment, the resilient retainers are discrete. What is meant by that is that the resilient retainers can easily be counted. There can be one, two, three, four, five, six, seven, eight or more resilient retainers present between the first and third flange. The resilient retainers can be arranged circumferentially or radially or in a combination of circumferentially or radially as will be explained in the more detailed preferred embodiments following:

[20] In a further preferred embodiment focus is on the resilient retainers. A first possibility is that the resilient retainers are provided as one or more brushes, bristles, oriented inward to the gap and circumferentially mounted to the first flange or to the third flange or to both the third and first flange. However, the latter arrangement is less preferred as too costly and also the brush hairs may entangle making it difficult to remove the wire from the storage section. The brushes are made of non-metal wire in order not to damage the metal wire. They can be made of man-made fibres, polyester, rayon, polyamide and the like, with brush wire diameters between 0.20 to 0.50 mm that is: sufficiently thick to be able to hold the stock wire in between the flanges. The brushes are radially between half and two centimetre wide and are angularly evenly present on the circumference of the first and/or third flange. That is: circumferential gaps can be present in between brushes.

[21] A second possibility to configure the resilient retainers is by means of metal blade springs. The springs are oriented inwardly and radially to the gap between first and third flange. The metal blade springs are configured - e.g. in bell shaped curve - such that they allow the stock wire to pass into the gap, but are prevented to come out by the spring back force. Preferably the metal blade springs are coated with a polymer e.g. polyamide to allow easy gliding of the wire and to prevent damage of the wire.

[22] A third and highly preferred realisation of the resilient retainers is to provide them in the form of elastomer fingers oriented inwardly to the gap. The fingers extend about the width of the gap. Possible elastomer materials are thermoplastic polyurethane or rubber, both known for their resilience, wear resistance and durability. Most preferred is rubber as it is cheap and very strong.

[23] Preferably the elastomer fingers are circularly mounted in the gap between the first and third flange, in one or more circles, for example two or three. The fingers may show a slight arcuate shape, oriented towards the core axis. The arcuate shape helps to keep the stock wire in place, while withstanding the spring back force of the stock wire. If the stock wire is pulled out the elastomer fingers easily give in, making it possible to remove the wire.

[24] According a second aspect of the invention, a method for adapting a metal wire spools is presented and defined in the accompanying method claims.

[25] The method is particularly intended to adapt an existing metal wire spool. A metal wire spool comprises a core defining a core axis and a core diameter, two - a first and second - flanges are attached to the distal ends of the core, mounted perpendicular to the core, wherein between the first and second flange there is a width, for receiving production wire and/or stock wire. The first and second flange have a flange diameter that is preferably equal, for easy rolling of the spool.

[26] A third flange is provided that has an annular shape. That is the shape of a disk with a central, not necessarily round, hole in it. The outside rim of the third flange is circular with a diameter that is equal to or less than the diameter of the first flange diameter. The inner rim has a maximum diameter, that is the maximum of all Feret diameters.

[27] On said third flange or on said first flange or on both, resilient retainers are mounted. Preferably the resilient retainers are mounted on the third flange, as the spool can then easily be brought to its original state by removal of the third flange.

[28] Thereafter the third flange is mounted such that a gap forms - the ‘storage section’ - between the first and third flange, wherein the resilient retainers are oriented, face the gap, the gap being less than half of the width between first and second flange. More preferably this gap is less than a fifth, eighth, or even tenth of the width. Preferably this gap is somewhere between five times to fifty times the diameter of the thickest wire one intends to put on the spool.

[29] The third flange can be mounted in two possibly positions:

A first possibility is that the third flange is mounted outside the first and second flange, at the side of the first flange. This has the advantage that the original workspace of the metal wire spool is not compromised: the capacity of the spool remains intact. The disadvantage is that the overall spool becomes wider which can become a problem when mounting the spool between existing take-up equipment: it may not be able to enter between the pintles of a wire drawing machine for example.

[30] The second possibility is that the third flange is provided in two halves, each spanning an 180° arc of a circle and is mounted between the first and second flange. The inner rim of the third flange is made circular with a diameter equal to the core diameter, to obtain a tight fit between the core and the third flange. This is important as the wire should not be able to enter the slit between core and third flange. Possibly this slit can be filled with silicone sealant.

[31 ] The advantage of this mounting is that the spool will fit in all equipment it used to fit in before. The disadvantage is that some workspace is lost to the storage section between first and third flange. By preference the third flange is mounted with nut and bolt to the first flange. An alternative is to weld the third flange to the core. In this way the slit between core and third flange is automatically closed. This makes the adaptation permanent and may also increase the cost of the adaptation.

[32] As before the first or said third flange may be provided with one or more slots, radially oriented to the core axis. They may be straight or curved. By preferences they are chamfered to limit damage to the metal wire when he is laid over from workspace to storage section or vice versa.

[33] As before the resilient retainers can take the shape of long, circular shaped brushes, metal blade springs (e.g. made of steel and coated with polyamide), or elastomer fingers. The function of those resilient retainers is crucial in that they must prevent that the metal wire would escape from the storage section when being cut.

Brief Description of Figures in the Drawings

[34] Figure 1 depicts a first embodiment of the metal wire spool;

[35] Figure 2a depicts a second embodiment of the metal wire spool;

[36] Figure 2b depicts a retainer for use in the second embodiment;

[37] Figure 3 depicts a perspective view of the second embodiment.

[38] The hundred digit of the reference numbers indicates the number of the main figure, the unit and tens digit refers to like items across different drawings.

Mode(s) for Carrying Out the Invention

[39] Figure 1 depicts a first embodiment of a metal wire spool 100 wherein a third flange 108 is mounted near the first flange 104 at the outer side of the first flange 104. The spool has a core 102 to which the first flange 104 is mounted to the distal end of the spool. At the opposite distal end the second flange 106 is mounted. The axis 103 of the core is indicated, that is also the axis of the spool. The width, that is the distance between first and second spool, is indicated by ‘W. The third flange 108 is welded against the ribs 105 in the first flange 104. The diameter of the outer rim of the third flange 108 is somewhat smaller than that of the first flange 104. The inner rim of the hole in the third flange 108 is larger than the diameter of the core 102.

[40] In this embodiment the outer side of the first flange 104 is provided by a ring of brushes 110. Below that a ring is mounted to prevent that wires would drop too deep. The stock wire 109 collects in this storage section. The brushes 110 retain the stock wire 109 when it is being cut. Slots (not shown) are made in the first flange to allow the switchover of the wire from storage section to workspace and back.

[41] In a second preferred embodiment 200 as shown in Figure 2a the third flange 208 is mounted in between the first 204 and second flange (not shown). In this embodiment, the third flange is held to the first flange by means of bolts 215 and there is a close fit between the inner rim of the third flange 208 and the core 202. The resilient retainers 210 are here a series of radially mounted rubber fingers 214, 214’, 214”. Figure 2b shows a detailed view of these rubber fingers: they have a stem 212 from which three fingers 214, 214’, 214” protrude in a slightly arcuate shape. An additional ring 207, mounted to the outer rim of the third flange 208, serves to keep these resilient retainers 210 in place, and also helps to guide the metal wire into the gap between the third flange and the first flange.

[42] Figure 3 shows the same embodiment 300 as in Figure 2a, 2b but with a perspective view. By providing the third flange 308 in two 180° arc halves 308’ and 308” closely matching the core 302, that are bolted to first flange 304, existing spools can be easily adapted with this system. The figure 3 further shows the openings wherein the stem of the fingers 312 are inserted and held. A chamfered slot 320 is provided to allow the metal wire to be guided from the workspace to storage section and vice versa.

[43] These metal spools enable the automation of several processes. In what follows a ‘robot’ refers to the automation system that allows to do the specified handling. For example on a dry wire drawing machine the start of the wire is provided with a hook by a first robot that hooks on one of the bolts holding the third flange to the first flange. After a few turns the robot switches the wire from the storage section to the workspace through the radial slots and accelerates to operative speed. When the spool is full the machine is decelerated and the first robot ends the wire in the storage section. The first robot cuts the metal wire and holds the next ‘start of the wire’ and ‘end of the wire’ separately. The end of the wire is attached to the first flange through an encoded opening, that is an opening of which the angular and radial position is known to the first robot. The spool is taken out of the dry drawing machine by a second robot and an empty spool is placed in the winder. The start end of the wire - still held by the first robot is provided with a hook and the procedure restarts. In the next step, both the start of the wire and the end of the wire can be reached from the gap between the first and third flange.