Apparatus for applying a torsional force to a wire

Abstract

To provide a device for imparting a torsional force onto a wire.SOLUTION: A device for imparting a torsional force onto a wire has a base and a support mounted so as to be rotatable with respect to the base around an axis of rotation. The axis of rotation coincides with a wire path extending through the base and the support. Further, a wire clutching device is mounted on the support and adapted to engage with a wire guided along the wire path, and a rotation mechanism is provided which is adapted for rotating the support with respect to the base.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an apparatus for applying a torsional force to a wire, which may be a welding wire. [Background technology]

[0002] Wire consumables are used in many industrial applications, from surface treatments such as metallization to joining metal parts in welding. In the coming years, wire will be increasingly used in the very important and continuously improving field of 3D printing.

[0003] In many industrial applications, where significant investments have been made in automation and robotic systems in recent times, maximizing productivity is essential and bulk containers with large quantities of consumables are preferred over smaller spools as they reduce interruptions and minimize spool change downtime. A commonly accepted parameter in the welding industry to measure changeover downtime teaches that it typically takes an average of 15 minutes to change an empty 15kg spool for a full new spool, and therefore spool change downtime can be quantified in one minute spent changing 1kg of wire. Based on this calculation, it is clear that a large pack or drum containing 1200kg of product equates to a saving of 20 hours of changeover downtime. These 20 hours could be better utilized to actively produce instead of having to continually interrupt production for spool changes. This advantage translates into a significant reduction in production costs and improves the efficiency of the manufacturing process.

[0004] It must be added that in certain welding processes, such as the production of fuel tanks or long welds on trailers or rail cars, stopping midway through a weld bead is generally unacceptable, as any unwanted production stoppage could result in additional complications and penalties in terms of quality consistency, and instead it is preferable for the weld bead to be uninterrupted from start to finish of the welding process. In certain metallization or welding applications, an unwanted interruption midway could result in complete rejection and scrapping of the part.

[0005] The centralized location of packs containing large amounts of wire consumables in specific concentrated areas (called "wire farms"), at a safe distance from the dangerous sparks generated by the welding arc and facilitating handling by forklifts, is now possible thanks to wire feed systems available on the market. The systems allow the wire to be transported smoothly and without friction through conduits with rolls over distances that can reach 100 meters from the location of the pack to the welding or metallizing torch where said wire consumables are actually melted or fused. The ability to locate large packs in safe centralized areas not only reduces the risks related to the handling and transportation of the packs and to the risk of fire due to welding sparks, but also facilitates inspections that do not require entry into the vicinity of the production cell and ultimately do not adversely affect the production cycle.

[0006] Bulk packs containing large amounts of wire, allowing production to continue uninterrupted, are an essential requirement for setting up a productive wire farm.

[0007] The supports carrying the wire are available in many different forms, from small spools carrying just 0.5 kg, to bulk containers carrying up to 2 tonnes of product.

[0008] There are several ways to store large amounts of wire consumables in bulk containers, ranging from large spools that require a rotary de-reeling device, to reel capstans that must be placed on a turntable to be emptied, but both expose the wire to potential contamination that can lead to rust or holes in the welds, and the need to use rotary devices to unwind large wire spools or reels takes up valuable and sometimes much-needed floor space.

[0009] A third, clearly more effective system was developed some years ago: the winding machine, which straightens, stretches and turns the wire to give it a plastic deformation, counter-torsion, and then places the wire in a container in the form of a horizontal coil. When the wire is unwound for consumption, it is easily and smoothly drawn from the fixed container without any great difficulty in feeding, without the need for a turntable or unwinding device, and if the winding process is done correctly, it does not get tangled before it leaves the pack. Although this process is called "twist-free" winding, it is not simple and depending on the hardness, columnar strength, grade and chemistry, the wire can still retain tension. This tension must be controlled during drawing, usually through a retainer plate of different weight and shape placed on the wire coil, so that only one strand at a time is drawn from the container. If more loops are accidentally unwound during the drawing process, tangles will soon occur and production will be interrupted.

[0010] The prior art teaches many inventions focused on developing or improving all kinds of systems for holding and braking the wire during payout, examples being plates of various shapes, from spherical marbles, that are allowed to fall freely on the wire, or holding devices with rotating wire guide arms and ribs under the plate to ensure that only one strand is drawn out and no more loops are drawn at the same time. The problem is that if too much tension is placed on the wire being paid out from the pack, regardless of the type of retainer used, some wire loops will inevitably be dragged towards the opening in the central plate, and the wire may fall and become tangled if it moves during transport. The first response is to always increase the holding weight to control the wire, but if the retainer plate is too heavy, the wire will inevitably deform, and the deformed wire may cause arc wandering problems and, as a result, welding quality problems, and even very heavy retainers cannot always control the wire.

[0011] Various wire retention systems are generally described in many prior art patents for aluminum and all steel wires.

[0012] US Pat. No. 5,746,380 describes a layer of spherical elements on a wire coil to control the payout of the wire.

[0013] WO 2016 / 022389 proposes a combination of a retaining plate with ribs and a wire guide rotating arm with a scope that constrains the wire and limits its range of movement while guiding the wire outward.

[0014] US Pat. No. 7,410,111 teaches a retainer plate having openings for weight reduction and to prevent deformation of the aluminum wire.

[0015] US Pat. No. 7,950,523 describes a combination of two interacting plates to control wire strands that become misaligned during shipping and handling.

[0016] All previously proposed solutions can be rendered ineffective in the presence of overly tensioned wires, as they can slip uncontrolled off the bottom of the retainer plate and fall into the center of the pack where they eventually become tangled.

[0017] Equipment efficiency combined with operator skill and reliable wire retainer plates can truly make the difference in minimizing residual tensions left on the wire by twist-free windings and ensuring smooth wire feeding. However, other variables can intervene during wire drawing and negatively affect the performance of the wire. Examples of such variables include misalignment of the wire feeder pressure rolls, worn pressure roll guide grooves, "U" shaped guide grooves as opposed to "V" shaped guide grooves or vice versa, or even worse, improperly sized grooves that do not fit the diameter of the wire being used. All of the above can contribute to tensioning the twist-free windings and as soon as the tension build-up exceeds the braking effect exerted by the retainer plates while the wire is being drawn from the container, the wire will pop out unchecked and eventually get tangled or jammed in the pack in the form of a single knot or a bunch of uncontrolled messy loops, causing the production interruptions that large bulk packs were designed to avoid in the first place.

[0018] The problem of residual tension still present in the wire after the twist-free winding process appears to be exacerbated with 5000 grade aluminum wire, but may affect all aluminum wire and even harder steel wires which are less prone to deformation. The behavior of 5000 grade aluminum wire is highly unpredictable and is probably related to the chemistry and hardness of the wire itself which may be altered by the annealing process it undergoes during manufacture. It has been noted that 5000 grade aluminum welding wire tends to partially revert to its pre-twisted state after a period of storage in bulk packs, and the smaller the container diameter the worse this type of "static" deformation appears to be. [Prior art documents] [Patent documents]

[0019] [Patent Document 1] U.S. Patent No. 5,746,380 [Patent Document 2] International Publication No. 2016 / 022389 [Patent Document 3] U.S. Patent No. 7,410,111 [Patent Document 4] U.S. Patent No. 7,950,523 Summary of the Invention [Problem to be solved by the invention]

[0020] In summary, even after a twist-free winding machine has performed a good job of accurately laying wire with minimal twists in the pack, and despite the skill and special care an operator exercises in adjusting the winding machine, other negative variables (such as equipment defects, improper adjustments, adjustments to container shape, etc.) can still adversely affect the performance of the wire. [Means for solving the problem]

[0021] The scope of the invention is to intervene in the wire at a point between the coil and the wire feeder by counteracting and neutralizing the residual tension in the wire to the extent that a payout control retainer plate may not even be necessary or at least a very light and flexible retainer plate can be used instead.

[0022] The present invention is designed to make the unwinding of wire from a bulk pack smooth and trouble-free and is specifically directed to aluminium welding wire but is applicable to wire in general after it has been placed in a bulk pack using a twist-free winding process.

[0023] Typically it consists of a counter-tension rotating device that can be placed anywhere between the wire coil and the wire feeder. In a preferred embodiment, to maximize its effectiveness, the device is mounted on top of the dome, at the point where the wire exits the puck.

[0024] The device comprises at least one, and preferably two (or more) wheels, the guide grooves of which are locked to the wire and which impart an anti-twisting motion to the wire by rotating it about its axis in a given direction (clockwise or counter-clockwise), preferably in a direction that unwinds the wire itself, which neutralizes any tension still present on the wire, whether it is the result of an imperfect twist-free winding process or of excess tension built up on the wire due to a misadjusted wheel pressure or faulty / worn roll grooves of the feeder.

[0025] Furthermore, the counter-twisting force applied to the wire generally keeps the wire urged toward the outer edge of the wire coil, preventing the wire loop from falling uncontrollably into the open space in the center of the bulk pack even after inadvertent displacement during handling or shipping.

[0026] The rotation of the strain relief can be actuated in two ways. (1) By the composite mechanical action of two or more wheels coupled to a rotating washer base and interacting with it through bevel gears. In this embodiment, one or more (preferably two) groups of grooved wheels are pressed against the wire being pulled by the feeder, engaging and rotating the round gear washer base with their bevel gears, and as they rotate they "clutch" or grab the wire, applying a counter twisting force in a predetermined desired direction, with the speed and direction of rotation depending on the shape and orientation of the bevel gears. (2) An electric motor that automatically determines the direction of twist along the wire axis while the wire is being unwound, where the motor speed and wire rotation are controlled by an external PLC that can be built into the wire feeder (as in the preferred embodiment) or located outside the wire feeder.

[0027] While in a mechanical embodiment the tension release rotation speed cannot be adjusted or paused later, a tension release device operated by a motor (which may be of any known type such as DC, AC, brushless or stepper) is clearly more preferable and more flexible, since it can be programmed via a PLC to perform several important functions automatically. It is possible to adapt the direction of rotation imparted to the wire to the winding direction of the wire. Furthermore, the control determines when excessive counter tension has built up in the wire and can activate or pause the rotation of the washer and grooved wheel via an electromagnet that engages or disengages the motor as required.

[0028] The motor engagement can also be actuated by a pneumatic or magnetic piston that presses a moving part of the device on which it is mounted against a rotating washer carrying a group of grooved wheels that contribute to impart a counter-twisting effect to the feed wire. In this case, the motor continues to rotate and engages the rotating washer only when a counter-twist is required to counteract the tension built up in the wire, but the motor can also engage the rotating washer continuously via a belt or bevel gear, whose function must then be controlled and programmed via an external PLC.

[0029] Generally speaking, neutralizing the tension caused by the counter-twisting of the wire along its axis in a clockwise or counterclockwise direction as required can actively contribute to the smooth unwinding of the wire even without the use of a retainer plate, or, if the use of a retainer plate is preferred, it can at least be very light and flexible, which can be clearly beneficial in preventing possible deformation of the softer aluminum wire.

[0030] In a preferred embodiment, the retainer plate is placed over the wire coil and can remain engaged to the wire during handling and shipping, but can be easily split into two or more sections for easy removal even with the wire already inserted into the guiding conduit.

[0031] The present invention provides an apparatus for applying a torsional force to a wire, the apparatus comprising: a base, a support rotatably mounted relative to the base about an axis of rotation, the axis of rotation coinciding with a wire path extending through the base and the support, a wire clutch device mounted on the support and adapted to engage a wire guided along the wire path, and a rotation mechanism configured to rotate the support relative to the base, the wire clutch device mechanically engaging the wire such that a torsional force can be applied to the wire in a desired range.

[0032] The wire clutching device may be provided in any form that allows for wire payout (i.e. translational movement of the wire along the wire path) while at the same time imparting rotational movement to the wire. Preferably, the wire clutching device is a pair of rolls mounted on the support, the rolls being positioned on either side of the wire path, at least one of the rolls having a wire receiving groove. A pair of rolls is a very simple yet effective means of mechanically engaging the wire to rotate it about its axis while allowing wire payout.

[0033] In order to ensure that the different wires can be rotated around their axes, a biasing device is provided for biasing the two rolls against each other, which allows the clutch force to be adapted to specific requirements.

[0034] The biasing device may comprise a hand wheel for applying a tightening torque to a biasing mechanism, with a torque limiter disposed in a torque path from the hand wheel to the biasing mechanism, the torque limiter preventing excessive force being applied to the wire by the biasing device.

[0035] According to one embodiment, a spring-loaded cam mechanism is provided which couples the hand wheel to the spindle nut, which allows the torque limiting function to be realised in a technically simple yet effective manner.

[0036] Preferably, the torque limiter is adjustable to allow the mechanism to be adapted to different wires. Furthermore, wear effects can be compensated for over time.

[0037] The rotation mechanism may include gears configured to convert movement of the wire along the wire path into rotation of the support relative to the base, thereby eliminating the need for a separate drive to rotate the wire clutch mechanism.

[0038] The gear may be a bevel gear having a ring gear connected to the base and a pinion rotatably mounted on the support, resulting in a compact rotation mechanism.

[0039] As an alternative to bevel gears, a very compact worm drive can be used.

[0040] The support is provided with two mounting positions for the pinion so that the direction in which the wire clutch device is rotated can be changed when a wire is pulled through the wheel of the wire clutch device.

[0041] A torque limiter associated with the rotation mechanism can very simply limit the maximum amount of twisting force to a desired threshold.

[0042] Also, the torque limiter can be arranged between the gear and the shaft on which the gear is arranged. In this way, a compact design can be achieved.

[0043] Preferably the torque limiter is adjustable to tailor the mechanism to different characteristics of the wire.

[0044] According to one embodiment, the torque limiter comprises a Belleville spring, which is beneficial in that it provides a spring force that varies only slightly over a wide compression range of the spring.

[0045] In another configuration, the rotation mechanism may include a drive motor attached to the base and configured to rotate the support relative to the base, the drive motor may be operated independent of the rate at which the wire is withdrawn through the wire clutch arrangement, thereby controlling the torsional force applied to the wire independent of the withdrawal rate of the wire.

[0046] A coupling device may be provided for coupling the motor to the support, allowing the motor to be disengaged and engaged at appropriate times.

[0047] In a technically simple yet reliable design, the coupling device comprises an application device for biasing a drive wheel coupled to the drive motor against a driven surface associated with the support.

[0048] The apparatus for applying a torsional force to the wire may include a motor current sensor to detect when too much torsional force is applied to the wire, i.e. the motor current is a good indicator of the applied torsional force.

[0049] The rotation mechanism may be an arm having a wire-receiving opening located eccentrically relative to the axis of rotation of the support, whereby tension in the wire is used to rotate the base.

[0050] The present invention also provides a system comprising a container in which a quantity of wire is contained in the form of a coil consisting of a number of loops of wire, an apparatus for applying a torsional force to the wire, the apparatus being mounted above the wire, the apparatus having a base, a support mounted rotatably about an axis of rotation relative to the base, the axis of rotation coinciding with a wire path extending through the base and the support, a pair of rolls mounted on the support, the rolls being arranged on either side of the wire path, at least one of the rolls having a wire receiving groove, and a rotation mechanism configured to rotate the support relative to the base, the system further comprising at least one wire feeder arranged downstream of the apparatus for applying a torsional force to the wire, the apparatus for applying a torsional force to the wire being conveniently controlled directly from a control of the wire feeder.

[0051] Preferably, two wire feeders are used, namely an auxiliary wire feeder located downstream of the device for imparting rotation to the wire and a main wire feeder located downstream of and at a considerable distance from the auxiliary wire feeder. The use of two wire feeders allows the wire container to be located at a considerable distance from the wire consumption.

[0052] In a preferred embodiment, the wire is a welding wire made from an aluminum alloy containing magnesium. Field tests have shown that this type of welding wire tends to develop internal stresses after some time in storage. Therefore, the effectiveness of the device for applying a torsional force to the welding wire is highly beneficial. [Brief description of the drawings]

[0053] [Figure 1] FIG. 2 shows a cross-sectional view of a container containing a wire coil. [Diagram 2] FIG. 2 shows a perspective view of the container of FIG. [Diagram 3] 2 shows the vessel of FIG. 1 with entangled wires; [Figure 4] 1 shows a side view of a system according to the present invention. [Diagram 5] 1 shows a container equipped with a device for applying a torsional force to a wire according to the invention; [Figure 6] 1 shows, in an exploded view, a first embodiment of the device for applying a torsional force to a wire. [Figure 7] FIG. 7 shows a perspective view of the device shown in FIG. 6. [Figure 8] FIG. 7 shows a top view of the device of FIG. [Figure 9] 2 shows, in an exploded view, a second embodiment of the device for applying a torsional force to a wire; [Figure 10] 10 shows the device of FIG. 9 in a perspective view. [Figure 11] 10 shows the device of FIG. 9 in side view. [Figure 12] 10 shows the device of FIG. 9 in a top view. [Figure 13] Various gear drives are shown. [Figure 14] 3 shows, in an exploded view, a third embodiment of the device for applying a torsional force to a wire. [Figure 15] 15 shows the device of FIG. 14 in a perspective view. [Figure 16] 15 shows the device of FIG. 14 in side view. [Figure 17] 15 shows the device of FIG. 14 in a top view. [Figure 18] 4 shows, in an exploded view, a fourth embodiment of the device for applying a torsional force to a wire; [Figure 19] FIG. 19 shows a side view of the device of FIG. 18. [Figure 20] FIG. 19 shows a perspective view of the device of FIG. [Figure 21] 19 shows an alternative side view of the device of FIG. 18. [Figure 22] FIG. 13 shows a first side view of a fifth embodiment of the device for applying a torsional force to a wire. [Figure 23] FIG. 13 shows a second side view of the fifth embodiment. [Figure 24] FIG. 13 shows a first perspective view of a fifth embodiment. [Diagram 25] FIG. 13 shows a second perspective view of the fifth embodiment. [Figure 26] FIG. 13 shows a perspective view of the fifth embodiment with the addition of a cover. [Figure 27] FIG. 13 shows an exploded view of a portion of the mechanism of the fifth embodiment. [Figure 28] 28 shows a partial cross-sectional view of the component of FIG. 27. [Figure 29] 29 shows a perspective view of the device of FIG. 28. [Diagram 30] The mechanism of FIG. 28 is shown in cross section. [Diagram 31] 4 shows a cross section of a torque limiter used in the device for applying a torsional force to a wire. [Diagram 32] 32 shows the torque limiter of FIG. 31 in side view. [Diagram 33] The torque limiter is shown in a second cross-sectional view. [Diagram 34]32 shows a partial cutaway side view of the torque limiter of FIG. 31. [Diagram 35] 32 shows a second partial cutaway side view of the torque limiter of FIG. 31. [Diagram 36] 34 and 35 are shown in top view. [Figure 37] 3 shows the torque limiter in a perspective view. [Figure 38] Detail of XXXVIII in FIG. 37 is shown. [Figure 39] In a similar manner to FIG. 5, an apparatus according to a sixth embodiment of the invention is shown. [Diagram 40] 39. The detail of XL in FIG. 39 is shown enlarged. [Diagram 41] 41 shows an enlarged view of the mechanism in FIG. 40. [Diagram 42] 41. This shows an enlarged detail of XLII in FIG. [Diagram 43] 41 shows an exploded view of the mechanism of FIG. 40. [Diagram 44] A view similar to FIG. 39 shows a seventh embodiment of the device. [Diagram 45] 44. FIG. 44 shows an enlarged detail of XLV. [Figure 46] 13 shows an exploded view of an eighth embodiment of the device. [Figure 47] FIG. 13 shows a perspective view of an eighth embodiment. [Figure 48] 13 shows a cross section of an eighth embodiment. [Figure 49] FIG. 13 shows a top view of the eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] In Figure 1, a container 1 is shown containing a quantity of wire 2 in the form of a coil 3. The coil 3 consists of a number of loops formed from said wire 2.

[0055] The wire 2 may be a welding wire, or any consumable wire used for 3D printing, metallization, etc.

[0056] The wire 2 is drawn out of the vessel 1 through a top opening of the vessel. The top of the vessel 1 may be provided with a cover or dome 4, the main purpose of which is to prevent contamination of the interior of the vessel 1 while the wire is being consumed.

[0057] A retainer 5 is placed on the top surface of the coil 3 to prevent the loop of wire from falling inside the coil 3. The main purpose of the retainer 5 is to provide a braking force to the wire and to create friction due to the weight of the wire.

[0058] 3, despite the presence of the retainer, some loops of the wire may fall inside the coil 3. If the loops become entangled, the wire cannot be pulled out of the container 1.

[0059] In FIG. 4 a system according to the invention is shown which prevents the loops from falling inside the coil 3 and becoming entangled.

[0060] A key element of the present invention is a device 10 for applying a torsional force to the wire 2. In general, the device 10 rotates the wire about its own axis, thereby counteracting some of the residual stresses in said wire and ensuring that the loop of wire remains in its position within the container 1.

[0061] Downstream of the device 10 may be located a wire feeder 6 which feeds the wire into a wire guide 7 and advances it towards where it is consumed, e.g. a welding robot. A main wire feeder may be used close to the welding robot so that the wire feeder 6 is an auxiliary wire feeder.

[0062] The device 10 is placed near the container 1. In the embodiment shown, the device 10 is placed on a dome 4 (see in particular FIG. 5).

[0063] In figures 6 to 8 a first embodiment of a device 10 for applying a torsional force to the wire is shown.

[0064] The apparatus 10 comprises a base 12 and a support 14. The support 14 is rotatably mounted relative to the base 12 about an axis 16 which coincides with the wire path along which the wire 2 is guided through the apparatus 10. A wire entry guide 15 is attached to the support 14.

[0065] Roller bearings 18 are used to attach the support 14 to the base 12 .

[0066] A wire clutch device 20 is attached to the support 14. This wire clutch device 20 here comprises two rolls 22 arranged on either side of the wire path 16, both rolls 22 each having a wire receiving groove 24.

[0067] The wire receiving groove 24 has a width and depth adapted to the dimensions of a particular wire so as to securely engage the wire. As the wire feeder 6 draws the wire from the container, the wire passes through the wire path 16 between two adjacent rolls 22, which are entrained or rotated by the wire.

[0068] The device 10 further comprises a rotation mechanism 26 configured to rotate the support relative to the base 12. The rotation mechanism 26 is here formed of a gear, in particular a bevel gear 28, with a ring gear 30 fixedly provided on the base 12 and a pinion 32 attached to the support 14.

[0069] A pinion 32 is coupled to one of the rolls 22 via a gear drive 34. Thus, when the roll 22 is geared by the wire, rotation of the roll is transmitted through the gear to the pinion 32, which engages the ring gear 30. Thus, the support 14 is rotated relative to the base 12 as the wire is drawn through the apparatus 10.

[0070] Once the roll 22 is tightly engaged with the wire, rotation of the support 14, and therefore the wire clutch arrangement 22, imparts a twisting force to the wire.

[0071] The amount of twisting force applied to the wire depends largely on the properties of the wire. For some wires, it has been found that good results are obtained by rotating the wire clutch device 20 1.5 times for each loop of wire drawn. The ratio of the number of revolutions per length of drawn wire can be adapted by selecting the size of the roll 22 and the transmission ratio of the rotation mechanism 26.

[0072] It will be apparent that the wire clutch device 20 needs to rotate in the same direction as the withdrawn wire rotates within the vessel 1. As an example, if the vessel 1 is viewed from above and said wire is withdrawn in a clockwise direction, the wire clutch device 20 will also need to rotate in a clockwise direction.

[0073] Two mounting positions for the pinion 32 are possible so that the device 10 can be adapted for both possible winding directions of said coil in the vessel 1. As can be seen in Figure 8, a mounting position 36 is provided for mounting the pinion 32 on the opposite side, thereby changing the direction of rotation.

[0074] To prevent excessive twisting forces on the wires, a torque limiter may be provided somewhere in the rotation mechanism 20. The torque limiter may be formed by a spring-loaded friction disk or similar mechanism.

[0075] A second embodiment of the device 10 is shown in figures 9 to 12. For components known from the first embodiment the same reference numerals are used and reference is made to the above description.

[0076] The general difference between the first and second embodiments is that in the second embodiment, the rotation mechanism 26 comprises a worm drive 29 formed from a worm gear 31 fixedly mounted on the base 12 and a screw gear 33 attached to the support 14.

[0077] The screw gear 33 is connected to one of the rolls 22 via a gear drive 34. Thus, when the roll 22 is geared by the wire, the rotation of the roll is transmitted via the gear to the screw gear 33 which engages the worm gear 31 and, when rotated, rotates the support 14 relative to the base 12.

[0078] As with the first embodiment, the sense of rotation can be reversed by mounting a gear drive 34 on the opposite side of the support 14.

[0079] It is also possible to replace the gear drive 34 with an electric motor so as to be able to rotate the support 14 relative to the base 12 independently of a fixed transmission ratio of wire payout to rotation of said support.

[0080] In a second embodiment, the transmission ratio from the roll 22 to the screw gear 33 can be advantageously modified, as will be explained below with reference to FIG.

[0081] In Figure 13a a small diameter vessel 1 is shown having a small diameter coil 3. To convert the rotation of the roll 22 into a suitable rotation of the screw gear 33 a large gear wheel 34a (see Figure 13b) is mounted on the axis on which the roll 22 is mounted, the gear wheel 34a driving a smaller gear wheel 34c which is drivingly connected to the screw gear 33 via an intermediate gear 34b.

[0082] In figure 13c a medium diameter vessel 1 is shown with a medium diameter coil 3. To convert the rotations of the roll 22 into smaller rotations of the screw gear 33 (per unit of length of drawn wire), a medium gear wheel 34a (see figure 13d) is mounted on the axis on which the roll 22 is mounted, which drives a medium gear wheel 34c which is drivingly connected to the screw gear 33 via an intermediate gear 34b.

[0083] In figure 13e a large diameter vessel 1 is shown having a large diameter coil 3. To convert the rotation of the roll 22 into a smaller rotation of the screw gear 33, a small gear wheel 34a (see figure 13f) is mounted on the axis on which the roll 22 is mounted, and the gear wheel 34a drives a large gear wheel 34c which is drivingly connected to the screw gear 33 via an intermediate gear 34b.

[0084] Intermediate gear 34b is mounted on a sliding guide 35, which allows the gear ratio to be quickly adapted to different pack sizes (and corresponding loop diameters within said packs).

[0085] A dust cover 17 closes the device 10 to prevent dirt and dust from entering the device 10 and the container 1.

[0086] A third embodiment of the device 10 is shown in figures 14 to 16. For components known from the first and second embodiments the same reference numerals have been used and reference is made to the above description.

[0087] The general difference between the first and second embodiments and the third embodiment is that the first and second embodiments are "passive" devices in which the torsional force applied to the wire is generated by the movement of the wire itself, whereas in the second embodiment the torsional force is actively generated by a motor.

[0088] In the third embodiment, a worm drive 29 is used, which is formed of a worm gear 31 and a screw gear 33. Here, the worm gear 31 is fixedly connected to the support 14, and the screw gear 33 is attached to the base 12.

[0089] A motor 40 is provided to drive the screw gear 33 (through suitable reduction gearing).

[0090] The rolls 22 are rotatably mounted on the support 14. The rolls are biased relative to each other with an adjustable force.

[0091] In the third embodiment, the device 10 is controlled by a control unit which can be integrated in the wire feeder 6. It is also possible for said control unit to be provided separately.

[0092] As the wire is withdrawn from the container 1, the electric motor 40 is actuated to rotate the wire clutch device 20 in the correct direction, thereby applying a twisting force to the wire.

[0093] The amount of rotation of the wire clutch device 20 per unit of length of drawn wire can be very conveniently controlled via the control unit. The motor current of the motor 40 can be controlled to prevent excessive twisting forces being applied to the wire. If excessive twisting forces should build up in the wire, more force is required to rotate the wire, and the motor current increases. In such a case, the motor 40 can be slowed down or stopped, or the biasing device 46 can be stopped to allow the support 14 to rotate freely, thereby releasing the twisting tension in the wire. The biasing device 46 can then be restarted and the operation of the motor 40 can resume.

[0094] An advantage of the third embodiment is that many of its components can be used both in the passive device according to the second embodiment and in the active device according to the third embodiment.

[0095] A fourth embodiment of the device 10 is shown in figures 17 to 20. For components known from the previous embodiments the same reference numerals are used and reference is made to the above description.

[0096] A general difference between the third and fourth embodiments is that in the fourth embodiment there is no meshing gear connection (and therefore no positive connection) between the motor and the support, but rather a frictional connection.

[0097] Here, the rotation mechanism 26 includes a drive motor 40 (electric motor) that drives a drive wheel 42. The electric motor 40, together with the drive wheel 42, is attached to a carrier 44 that is swingably connected to the base 12.

[0098] A biasing device 46, here in the form of a solenoid, is attached to the base 12 and is configured to urge the carrier 44, together with the motor 40 and the drive wheel 42, in a direction towards the support 14. More specifically, the biasing device 46 presses the drive wheel 42 against a cylindrical driven surface 48 of the support 14.

[0099] The drive wheel 42 may be provided with an O-ring 50 or some other friction enhancing element to ensure that the support 14 can be rotated by the motor 40 .

[0100] The wire clutch device 20 of the fourth embodiment basically corresponds to the first embodiment and comprises two rolls 22 which are biased against each other and against the wire passing between said rolls. Here, a biasing device 52 is provided which makes it possible to vary the force with which the two rolls are pressed against each other.

[0101] As the wire is withdrawn from the container 1, the electric motor 40 is actuated to rotate the wire clutch device 20 in the correct direction, thereby imparting the desired twisting force to said wire. At the same time, the biasing device 46 is actuated to ensure that the power of the motor 40 is transmitted to the support 14.

[0102] In Figure 21 an alternative to the embodiment of Figures 17 to 20 is shown, in which the drive wheel 42 is connected to the support 14 via a belt or rubber ring 60, thereby eliminating the need for a biasing device.

[0103] In figures 22 to 30 another embodiment of said device for applying a torsional force to a wire is shown, for elements already known from the previous embodiments the same reference numbers are used and reference is made to the above description.

[0104] The embodiment of Figures 22 to 30 is equivalent to the embodiment of Figures 6 to 13 in that movement of the wire through the wire path 16 results in rotation of the roll 22, which is translated into rotation of the support 14 relative to the base 12.

[0105] The gear drive 34 here comprises a shaft 70 on which one of the rolls 22 and one of two gear wheels 72 are mounted, which synchronize the rotation of the two rolls 22. Furthermore, the shaft 70 is fitted with a gear wheel 74, which meshes with an additional gear wheel which finally cooperates with the screw gear 32 which engages with the worm gear 31.

[0106] A torque limiter 76 is disposed in the torque transmission path between the shaft 70 and the gear wheel 34 .

[0107] In general, the torque limiter 76 prevents excessive torque from being transmitted from the shaft 70 to the gear wheel 74 .

[0108] The torque limiter 76 includes a retaining ring 78 , a spring 80 , here a Belleville spring, an adjustment screw 82 , and a locking mechanism 84 .

[0109] The gear wheel 74 is disposed adjacent a shoulder 84 of the shaft 70. By threading an adjustment screw 82 onto the shaft 70, a spring 80 is biased by the adjustment screw 82 against the retaining ring 78, which in turn presses the gear wheel 74 against the shoulder 84. Thus, a frictional force is created which allows the transmission of torque from the shaft 70 to the gear wheel 74 up to a predetermined threshold.

[0110] The level of allowable torque transfer can be adjusted by adjusting an adjustment screw 82 on the shaft 70. A locking mechanism 86 can lock the adjustment screw 82 in position once the desired level of torque transfer is achieved.

[0111] The torque limiter ensures that excessive twisting forces will not be imparted to the wire.

[0112] 31-38 show details of the biasing device 52 used to vary the force with which the rolls 22 are pressed against each other.

[0113] The biasing device 52 functions to exert a force on a lever 53, which results in a force urging the rolls 22 towards each other.

[0114] The biasing device 52 comprises a traction rod 90 connected to the lever 53 and capable of exerting a traction force by the biasing device 52 , the biasing device 52 being supported at an abutment 92 .

[0115] The abutment portion 92 has a hook shape which engages with a wedge-shaped retainer portion 94 (see especially Figures 31 to 37).

[0116] The pressure part 94 supports a nut 96 which is screwed onto the traction rod 90. The nut 96 can be rotated by a hand wheel 98 which is connected to the nut 96 by a cam mechanism 100. The cam mechanism 100 comprises a cam surface 102 provided on the nut 96 and a pressure pin 104 supported on the hand wheel 98 so as to be displaceable in a direction parallel to the axis of rotation of the hand wheel 98. On the side facing away from the cam surface 102, the pressure pin 104 is engaged by a pressure washer 106 which is biased towards the pressure pin 104 by a stack of springs 108. Here, a Belleville spring is used.

[0117] The spring 108 is capped in a preloaded state by an adjustment wheel 110 and its axial position is adjustable by a set screw 112. The set screw 112 is accessible after removal of a cap 114.

[0118] By rotating the set screw 112, the preload of the spring 108 can be adjusted. By adjusting said preload, the maximum torque that can be transferred to the cam surface 102 of the nut 96 by rotation of the pressure pin 104 can be adjusted. Looking at FIG. 38, clockwise rotation of the hand wheel 98 will be accompanied by rotation of the nut 96, unless the necessary force causes the pressure pin 104 to slide upwards on the cam surface 102 against the force of the spring 108 and finally clear of said cam surface. In the reverse direction, the pressure pin 104 will slide downwards on the cam surface 102 and engage at an end stop to positively engage the nut 96.

[0119] Once the desired level of torque transfer from hand wheel 98 to nut 96 is adjusted by set screw 112, lock screw 116 is tightened.

[0120] In figures 39 to 43 yet another embodiment of a device for applying a torsional force to a wire is shown. For elements already known from the previous embodiments the same reference numbers are used and reference is made to the above comments.

[0121] The general difference between the embodiment of figures 39 to 43 and the previous ones is that in the embodiment of figures 39 to 43 the support 14 with the roll 22 is rotated only under the influence of the wire 2. There is no motor for rotating said support, and no gears that convert the rotation of the roll 22 into the rotation of said support.

[0122] Here, the support 14 is rotated by an arm 120 having a wire receiving opening 122 arranged eccentrically with respect to the axis of rotation of the support 14. As the wire 2 is held in the container 1 in the form of a coil, the traction force acting between the part of the wire that goes between the rolls 22 and the part of the wire that has been received in the form of a coil creates a force at the wire receiving opening 122 that has a force component directed in the circumferential direction.

[0123] An alternative to the embodiment of Figures 39 to 43 is shown in Figures 44 and 45. The difference between the alternative embodiment and the previous ones is that it uses a flexible wire guide 130 which is held in a tube 132 such that the end where the wire 2 exits the wire guide 130 is positioned eccentrically with respect to the axis of rotation of the support 14.

[0124] In figures 46 to 49 yet another embodiment of a device for applying a torsional force to a wire is shown. For components known from the previous embodiments the same reference numbers are used and reference is made to the above description.

[0125] In the embodiment of Figures 46 to 49, the device 10 has an electric motor 140 that is used to actively rotate the rolls 22. Downstream of the rolls 22 are provided two sets of straightening rolls 142 for straightening the wire. The rolls 22, driven by the motor 140, serve to push the wire through the set of straightening rolls 142.

[0126] The motor 140 is powered by a sliding contact 144 disposed concentrically about the axis of rotation of the device 10 .

Claims

1. 1. An apparatus for applying a torsional force to a wire, comprising: With the base, a support rotatably mounted relative to the base about an axis of rotation, the axis of rotation coinciding with a wire path extending through the base and the support; a wire clutch device attached to the support and configured to engage a wire guided along the wire path; a rotation mechanism configured to rotate the support relative to the base, The wire clutch device is a pair of rolls attached to the support, the rolls being disposed on opposite sides of the wire path, and at least one of the rolls having a wire receiving groove; A biasing device is provided for biasing the two rolls toward each other; The apparatus, wherein the biasing device has a hand wheel for applying a tightening torque to a biasing mechanism, and a torque limiter is disposed in a torque path from the hand wheel to the biasing mechanism.

2. 2. The apparatus of claim 1, wherein a spring loaded cam mechanism is provided connecting the hand wheel to a spindle nut.

3. The apparatus of claim 1 or claim 2, wherein the torque limiter is adjustable.

4. The apparatus of claim 1 , wherein the rotation mechanism comprises gears configured to translate movement of the wire along the wire path into rotation of the support relative to the base.

5. 5. The apparatus of claim 4, wherein the gear is a bevel gear having a ring gear connected to the base and a pinion rotatably mounted to the support.

6. The apparatus of claim 5 , wherein two mounting locations for the pinion are provided on the support.

7. The apparatus of claim 4 , wherein the gear is a worm drive.

8. 8. Apparatus according to any one of claims 4 to 7, in which an intermediate gear wheel is provided which is mounted on the sliding guide.

9. An apparatus according to any one of claims 4 to 8, wherein a torque limiter is associated with the rotation mechanism.

10. The apparatus of claim 9 , wherein the torque limiter is disposed between the gear and a shaft on which the gear is disposed.

11. The apparatus of claim 10 , wherein the torque limiter is adjustable.

12. 11. The apparatus of claim 9 or claim 10, wherein the torque limiter comprises a Belleville spring.

13. An apparatus for applying a torsional force to a wire, comprising: With the base, a support rotatably mounted relative to the base about an axis of rotation, the axis of rotation coinciding with a wire path extending through the base and the support; a wire clutch device attached to the support and configured to engage a wire guided along the wire path; a rotation mechanism configured to rotate the support relative to the base, The apparatus, wherein the rotation mechanism comprises a drive motor attached to the base and configured to rotate the support relative to the base.

14. 14. The apparatus of claim 13, wherein a coupling device is provided for coupling the motor to the support.

15. 15. The apparatus of claim 14, wherein the coupling device comprises a restraint device for urging a drive wheel coupled to the drive motor against a driven surface associated with the support.

16. 16. Apparatus according to any of claims 13 to 15, wherein a motor current sensor is provided.

17. 17. Apparatus according to any preceding claim, wherein the rotation mechanism is an arm having a wire-receiving opening disposed eccentrically relative to the axis of rotation of the support.

18. 18. Apparatus according to any of the preceding claims, wherein a wire straightener is arranged on the support.

19. a container in which a quantity of wire is contained in the form of a coil consisting of multiple loops of wire; 14. A device for applying a torsional force to a wire according to claim 1 or 13, the device being mounted above the wire; A system comprising: The system further comprises at least one wire feeder disposed downstream of the apparatus for applying a torsional force to the wire.

20. The system of claim 19 , wherein a retainer is disposed on the coil of wire.

21. 21. The system of claim 20, wherein the wire feeder located downstream of the device for imparting rotation to the wire is an auxiliary wire feeder, and a main wire feeder is provided downstream of the auxiliary wire feeder.

22. a container in which a quantity of wire is contained in the form of a coil consisting of multiple loops of wire; 14. A device for applying a torsional force to a wire according to claim 1 or 13, the device being mounted above the wire; A system comprising: at least one wire feeder arranged downstream of said device for applying a torsional force to said wire; The system further comprises a control unit for controlling a rotation speed of a drive motor of the rotation mechanism, the control unit having a torque detection unit for limiting the torsional force applied to the wire.

23. 23. The system of claim 22, wherein the wire is a welding wire made from an aluminum alloy containing magnesium.

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