METHOD AND SYSTEM FOR WINDING A CONTINUOUS ELONGATE ELEMENT

Abstract

A method and a system of winding a continuous elongate element onto cylindrical elements. The continuous elongate element is wound from a feeder onto a first cylindrical element. The first cylindrical element rotates with the same rotational speed as a second cylindrical element provided on the other side of a central rotatable member. During the rotation, the feeder is displaced from being aligned with the first cylindrical element to being aligned with the second cylindrical element, wherein the displacement causes the continuous elongate element to come into engagement with an engagement portion of the central rotatable member, preventing the already wound portion of the continuous elongate element from being unwound from the first cylindrical element. The continuous elongate element from the feeder is continued to be wound onto the second cylindrical element by continuing to rotate the second cylindrical element.

Claims

1. A method of winding a continuous elongate element, onto cylindrical elements, the method comprising: winding the continuous elongate element from a feeder onto a first cylindrical element by rotating the first cylindrical element, providing a second cylindrical element so that the first cylindrical element and the second cylindrical element are located on respective sides of a central rotatable member such that the first cylindrical element, the second cylindrical element and the central rotatable member have the same geometrical rotational axis and rotate with the same rotational speed, while the first cylindrical element, the second cylindrical element and the central rotatable member rotate, displacing the feeder from being aligned with the first cylindrical element to being aligned with the second cylindrical element, wherein the displacement causes the continuous elongate element to come into engagement with an engagement portion of the central rotatable member, preventing the already wound portion of the continuous elongate element from being unwound from the first cylindrical element, and winding the continuous elongate element from the feeder onto the second cylindrical element by continuing to rotate the second cylindrical element.

2. The method as claimed in claim 1, comprising, when the continuous elongate element is being wound onto the second cylindrical element, cutting the continuous elongate element at its engagement with the engagement portion so as to split it into two portions, a first portion already wound onto the first cylindrical element and a second portion which is still being winded onto the second cylindrical element, and removing the first cylindrical element axially away from the second cylindrical element while the second cylindrical element is still rotating.

3. The method as claimed in claim 2, comprising, when the continuous elongate element is being wound onto the second cylindrical element, providing a third cylindrical element, at the previous winding position of the first cylindrical element, so that the second cylindrical element and the third cylindrical element are located on respective sides of the central rotatable member such that the second cylindrical element, the third cylindrical element and the central rotatable member have the same geometrical rotational axis and rotate with the same rotational speed, while the second cylindrical element, the third cylindrical element and the central rotatable member rotate, displacing the feeder in parallel with said axis from being aligned with the second cylindrical element to being aligned with the third cylindrical element, wherein the displacement causes the continuous elongate element to come into engagement with the engagement portion of the central rotatable member, preventing the already wound portion of the continuous elongate element from being unwound from the second cylindrical element, and winding the continuous elongate element from the feeder onto the third cylindrical element by continuing to rotate the third cylindrical element.

4. A system for winding a continuous elongate element onto cylindrical elements, the system comprising: a feeder from which the continuous elongate element is providable to cylindrical elements in consecutive order, a plurality of cylindrical elements for receiving and winding said continuous elongate element, a central rotatable member provided with an engagement portion, and a control unit, wherein the control unit is configured to: align the feeder with a first cylindrical element of said plurality of cylindrical elements for winding the continuous elongate element onto the first cylindrical element by rotating the first cylindrical element, provide the first cylindrical element and a second cylindrical element of said plurality of cylindrical elements on respective sides of the central rotatable member along a common geometrical rotational axis, rotate the first cylindrical element, the second cylindrical element and the central rotatable member with the same rotational speed, while the first cylindrical element, the second cylindrical element and the central rotatable member rotate, cause the feeder to be displaced from being aligned with the first cylindrical element to being aligned with the second cylindrical element, wherein the displacement causes the continuous elongate element to come into engagement with the engagement portion of the central rotatable member, preventing the already wound portion of the continuous elongate element from being unwound from the first cylindrical element, and continue to rotate the second cylindrical element for winding the continuous elongate element from the feeder onto the second cylindrical element.

5. The system as claimed in claim 4, wherein each cylindrical element comprises a cylindrical winding portion delimited by a wall portion at each end of the cylindrical winding portion, wherein, when the first cylindrical element, the second cylindrical element and the central rotatable member rotate around the common geometrical rotational axis, the radial distance between the common geometrical rotational axis and the engagement portion is larger than the radial distance between the common geometrical rotational axis and a circumference of said wall portions of the first and second cylindrical elements.

6. The system as claimed in claim 4, wherein the engagement portion of the central rotatable member comprises a plurality of protrusions, wherein the plurality of protrusions present abutment surfaces for catching the continuous elongate element as the feeder is moved from being aligned with the first cylindrical element to being aligned with the second cylindrical element.

7. The system as claimed in claim 4, comprising a cutter, wherein the control unit is configured to control the cutter to cut the continuous elongate element at its engagement with the engagement portion so as to split it into two portions, a first portion already wound on the first cylindrical element and a second portion which is still being winded onto the second cylindrical element.

8. The system as claimed in claim 7, wherein the central rotatable member comprises a circular slit extending along the periphery of the central rotatable member, wherein the circular slit is configured to receive the cutter for enabling the cutter to split the continuous elongate element into two portions.

9. The system as claimed in claim 7, comprising a first motor configured to drive a first rotatable shaft, the first rotatable shaft being configured to receive and hold a cylindrical element on one side of the central rotatable member, a second motor configured to drive a second rotatable shaft, the second rotatable shaft being configured to receive and hold a cylindrical element on the opposite side of the central rotatable member, wherein the control unit is configured to control the operation of the first and the second motors.

10. The system as claimed in claim 9, wherein the first rotatable shaft is provided with a first spindle which is displaceable along said geometrical rotational axis, the first spindle being provided with a first magnet, wherein the second rotatable shaft is provided with a second spindle which is displaceable along said geometrical rotational axis, the second spindle is provided with a second magnet, wherein the central rotatable member is provided with one or more magnetic portions, for magnetically connecting the central rotatable member to the first magnet and the second magnet to enable the central rotatable member to rotate with cylindrical elements held by the first and second rotatable shafts.

11. The system as claimed in claim 10, wherein after the cutter has cut the continuous elongate element, the control unit is configured to disconnect the first magnet from said one or more magnetic portions of the central rotatable member and axially remove the first cylindrical element from the central rotatable member which continues to rotate with the second cylindrical element.

12. The system as claimed in claim 11, wherein the control unit is configured to provide a third cylindrical element to the first rotatable shaft to arrange the third cylindrical element at the previous winding position of the first cylindrical element, so that the second cylindrical element and the third cylindrical element are located on respective sides of the central rotatable member such that the second cylindrical element, the third cylindrical element and the central rotatable member have the same geometrical rotational axis and rotate with the same rotational speed.

13. The system as claimed in claim 9, wherein the control unit is configured to control the first and second motor in master-slave- synchronization mode in which the slave is synchronized with the rotational speed of the master, wherein at any given point in time, the one of the first and second motors that is operating a cylindrical element onto which the continuous elongate element is currently being winded is the master, while the other one of the first and second motors is the slave.

14. The system as claimed in claim 7, comprising at least one roller, wherein the control unit is configured to apply the at least one roller against the already winded portion of the continuous elongate element before the cutter cuts the continuous elongate element.

15. The system as claimed in claim 4, wherein the control unit is configured to receive input parameter values relating to dimensions of an individual cylindrical element of said plurality of cylindrical elements and/or relating to dimensions of the continuous elongate element, wherein the control unit is configured to, based on the received input parameter values, determine when to switch the winding of the continuous elongate element from the first cylindrical element to the second cylindrical element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

[0065] In the drawings:

[0066] FIG. 1 illustrates a system according to at least one exemplary embodiment of the present invention.

[0067] FIG. 2 illustrates a cross-sectional view of a part of the system.

[0068] FIG. 3 is a close-up view of details in FIG. 2.

[0069] FIG. 4 illustrates, similarly to FIG. 2, a cross-sectional view of a part of the system, however, in a different state.

[0070] FIG. 5 is a close-up view of details in FIG. 4.

[0071] FIG. 6 illustrates, similarly to FIG. 2 and FIG. 4, a cross-sectional view of a part of the system, however in yet another state.

[0072] FIG. 7 illustrates a central rotatable member which may be used in a system according to at least some exemplary embodiments of the present invention.

[0073] FIG. 8 illustrates the system winding a continuous elongate element onto cylindrical elements.

[0074] FIG. 9 is a close-up view of details of FIG. 8.

[0075] FIG. 10 is a cross-sectional view of a part of the system, the cross-section being in a horizontal plane.

DETAILED DESCRIPTION

[0076] The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which certain aspects of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments and aspects set forth herein; rather, the embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Accordingly, it is to be understood that the present invention is not limited to the embodiments described herein and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims. Like reference numerals refer to like elements throughout the description.

[0077] FIG. 1 illustrates a system 1 according to at least one exemplary embodiment of the present invention. The system 1 comprises a plurality of cylindrical elements 2 onto which a continuous elongate element 4 is to be winded (see FIG. 8 and FIG. 9). Each cylindrical element 2 will thus receive a respective portion of the continuous elongate element 4. As explained previously in this disclosure, the cylindrical elements 2 may be of various different types. In this exemplary embodiment, the cylindrical elements 2 are illustrated in the form of spools. As also explained previously, the continuous elongate element 4 may be any suitable windable element, such as a filament, thread, wire, cable, etc.

[0078] As illustrated in FIG. 1, the system 1 may suitably comprise a pre-winding section 6, a winding section 8 and a post-winding section 10. The pre-winding section 6 may, for instance, comprise storage arrangements 12 for holding cylindrical elements 2 before they are provided in position for receiving the continuous elongate element 4. In this exemplary embodiment two storage arrangements 12 are illustrated, each one holding a respective stack of cylindrical elements 2 that are to be consecutively presented to the winding section 8. As discussed previously in this disclosure, in some exemplary embodiments, the cylindrical elements may be reused (e.g. when being in the form of mandrels that are temporarily expandable for receiving the continuous elongate element 4 to form a coil, and thereafter returning to a non- expanded state for releasing the finished coil). In such cases, the storage arrangements 12 may be omitted, if desired. It should, however, be understood that the storage arrangements 12 in FIG. 1 are just illustrating one example out of many conceivable examples. The pre- winding section 6 may thus provide the cylindrical elements 2 to the winding section 8 in numerous ways.

[0079] The winding section 8 is here illustrated as having a central part 14 and two side parts 16, which may be at least partly enclosed in a casing. The central part 14 of the winding section 8 is the location at which the cylindrical elements 2 are positioned when they receive the continuous elongate element 4, i.e. when the continuous elongated element 4 is winded onto a cylindrical element 2. The side parts 16 may include various actuating mechanisms, such as motors, for rotating and/or displacing the cylindrical elements 2. However, motors and other actuating mechanisms may also be located in the central part 14. Motors will be discussed in more detail below in connection with the discussion of other drawing figures.

[0080] The post-winding section 10, which in some embodiments may be omitted, may be of any suitable form for receiving the cylindrical elements 2 after they have been provided with the thereon winded continuous elongate element 4 (or for receiving winded coils without the cylindrical elements). The post-winding section 10 is here illustrated as including a receiving rail, however other receiver or means of transport (such as conveyors) are conceivable to include in the post-winding section 10. FIG. 1 merely presents a very general overview of the system 1, and therefore the cylindrical elements 2 at the post-winding section 10 are not illustrated as having received the continuous elongate element 4 (which, as mentioned previously is shown in FIG. 8 and FIG. 9).

[0081] As illustrated in FIG. 1, the system 1 comprises a control unit 20 configured to control the operation of the system 1. The control unit 20 may comprise or be operatively connected to a user interface, such as including a display, for providing information to an operator and/or for receiving input data from an operator. More detailed discussion of the control unit 20 will follow further below.

[0082] Turning to FIG. 2, there is illustrated a cross-sectional view of a part of the system, more specifically the winding section 8. The system comprises a feeder 22 from which the continuous elongate element 4 (shown in FIGS. 8 and 9) may be provided to the cylindrical elements 2. The feeder 22 is here illustrated as having a tubular shape, such as a pipe, however, other configurations are also conceivable. The feeder 22 may suitably receive the continuous elongate element 4 from a suitable source. For instance, in the case of the continuous elongate element 4 being a plastic filament, the feeder 22 may receive it at the end of an extrusion equipment which forms and extrudes the filament. However, any other suitable means of supply to the feeder 22 may be provided.

[0083] In FIG. 2, there is illustrated a central rotatable member 24. An example of the configuration of the central rotatable member 24 will be later discussed in connection with FIG. 7. In FIG. 2, on either side of the central rotatable member 24 there has been provided a respective cylindrical element. For simplicity, in this discussion, the cylindrical element on the right hand side in the drawing will be referred to as a first cylindrical element 2a, and the cylindrical element on the left hand side will be referred to a as a second cylindrical element 2b. It should, of course, be understood that the herein assigned order numbers of the cylindrical elements are not bound to the left or the right side of the central rotatable member 24.

[0084] The feeder 22 is displacable such that it can be aligned with either one of the first cylindrical element 2a and the second cylindrical element 2b. For instance, if the feeder is aligned with the first cylindrical element 2a then the continuous elongate element 4 would be providable from the feeder 22 to the first cylindrical element 2a. In order to operate the rotation of the cylindrical elements 2, 2a, 2b for winding the continuous elongate element 4 onto the cylindrical elements, a motor may suitably be provided on each side of the central rotatable member 24. Thus, a first motor 26a is provided for enabling rotation of the first cylindrical element 2a and a second motor 26b is provided for enabling rotation of the second cylindrical element 2b (see FIG. 10).

[0085] Turning now to FIG. 3 and FIG. 10, it may be noted that FIG. 3 is a close-up view of details in FIG. 2. FIG. 10 is a cross-sectional view of a part of the system, taken in a horizontal plane, thus viewed from above. As regards FIG. 3, the details on the left side have been zoomed in, i.e. the details relating to components affecting the operation of the second cylindrical element 2b. It should be understood that, corresponding details are provided on the right side for affecting the operation of the first cylindrical element 2a. As can be seen in FIG. 10, the first motor 26a is configured to drive a first rotatable shaft 28a and the second motor 26b is configured to drive a second rotatable shaft 28b. As can be seen in FIG. 3, the second rotatable shaft 28b is configured to receive and hold a cylindrical element on the one side of the central rotatable member 24, i.e. in this case the second cylindrical element 2b (similarly, the first rotatable shaft 28a may hold the first cylindrical element 2a on the opposite side, as seen in FIG. 10). The control unit 20 (see FIG. 1) is configured to control the operation of the first motor 26a and the second motor 26b.

[0086] Each one of said rotatable shafts is provided with a respective spindle. Thus, with reference to FIG. 3, the second rotatable shaft 28b is illustrated as being provided with a second spindle 30b which is displaceable along the common geometrical rotational axis around which the cylindrical elements 2a, 2b and the central rotatable member 24 are configured to commonly rotate (similarly, the first rotatable shaft is provided with a displaceable first spindle). The second spindle 30b is provided with a second magnet 32b, here illustrated at an end of the second spindle 30b (similarly the first spindle is provided with a first magnet 32a, which can be seen in FIG. 3).

[0087] As best seen in FIG. 7, the central rotatable member 24 may suitably be provided with one or more magnetic portions 36, suitably presenting a magnetic surface on both sides of the central rotatable member 24. The one or more magnetic portions 36 are provided for magnetically connecting the central rotatable member 24 to the first magnet 32a and the second magnet 32b to enable the central rotatable member 24 to rotate with the cylindrical elements 2a, 2b held by the first rotatable shaft and the second rotatable shaft 28b.

[0088] Thus, turning back to FIG. 3, although the second spindle 30b is displaceble in the axial direction relative to the part of the second rotatable shaft 28b which holds the second cylindrical element 2b, the second spindle 30b may suitably be configured to rotate with the second rotatable shaft 28b in order to enable the second cylindrical element 2b (driven by the second rotatable shaft 28b) and the central rotatable member 24 (connected to the second magnet 32b) to be rotated at the same speed. Corresponding relationship may, of course, suitably apply to the first rotatable shaft, the first spindle and the first magnet.

[0089] From the above, it can be understood that, in general terms, according to at least one exemplary embodiment, the first spindle and the second spindle are rotatably lockable to the first rotatable shaft and the second rotatable shaft, respectively. According to at least one exemplary embodiment, the first spindle and the second spindle are axially movably in a bore of the first rotatable shaft and the second rotatable shaft, respectively (as for example illustrated in the figures). According to at least one exemplary embodiment, the first spindle and the second spindle extend along the common geometrical axis (as for example seen in the figures).

[0090] When a cylindrical element is to be removed from the central rotatable member 24, then suitably the associated magnet 32a or 32b is first disconnected from the mating magnetic portion 36 of the central rotatable member 24. This is illustrated in for example FIGS. 4 and 5.

[0091] FIG. 4 illustrates, similarly to FIG. 2, a cross-sectional view of a part of the system, however, in a different state. FIG. 5 is a close-up view of details in FIG. 4. As best seen in FIG. 5, the first magnet has been disconnected from the magnetic portion 36 of the central rotatable member 24. This is normally done when the continuous elongate element has been wound onto the first cylindrical element 2a, and after a cutter 38 has cut the continuous elongate element. In FIG. 5, the cutter 38 is illustrated as comprising a blade, however, other means of cutting may be conceivable. Thus, the control unit 20 (FIG. 1) may be configured to do this disconnection action and also to axially remove the first cylindrical element 2a from the central rotatable member 24 which continues to rotate with the second cylindrical element 2b. The action of removal of the first cylindrical element 2a from the central rotatable member 24 is illustrated in FIG. 6.

[0092] Thus, FIG. 6 illustrates, similarly to FIG. 2 and FIG. 4, a cross-sectional view of a part of the system, however now the first cylindrical element 2a has been removed by the first rotatable shaft 28a and the first magnet 32a has been disconnected from the magnetic portion 36 of the central rotatable member 24. In the illustrated embodiment, the shaft 28a is fixed in a head part 15. The head part 15 is movable along a track 17. The movement of the head part 15 may be accomplished by a suitable actuator (not shown). By moving the head part 15, the thereto fixed shaft 28a will follow. It should be understood that in other exemplary embodiments the rotatable shafts 28a, 28b may be arranged to be movable without fixing them to a respective head part 15 that is slidable along a track 17.

[0093] From the above, it can be understood that, in general terms, according to at least some exemplary embodiments, the first rotatable shaft and the second rotatable shaft are movable in the axial direction (in this disclosure axial direction refers to the direction of the common geometrical rotational axis) in order to selectively retract the respective cylindrical element from the central rotatable member or advance the respective cylindrical element towards the central rotatable member.

[0094] After the first cylindrical element 2a has been removed from the central rotatable member 24, it may be transferred to the post-winding section 10 (FIG. 1) of the system. A new cylindrical element may therefore be received from the pre-winding section 6 (FIG. 1). Thus, the control unit 20 may be configured to provide a third cylindrical element (for example from one of the stacks illustrated in FIG. 1) to the first rotatable shaft 28a so as to arrange the third cylindrical element at the previous winding position of the first cylindrical element 2a. Thus, the second cylindrical element and the third cylindrical element will then be located on respective sides of the central rotatable member 24 such that the second cylindrical element, the third cylindrical element and the central rotatable member 24 have the same geometrical rotational axis and rotate with the same rotational speed.

[0095] The control unit 20 is suitably configured to control the first and second motor 26a, 26b in master-slave-synchronization mode in which the slave is synchronized with the rotational speed of the master, wherein at any given point in time, the one of the first and second motors 26, 26b that is operating a cylindrical element onto which the continuous elongate element is currently being winded is the master, while the other one of the first and second motors is the slave.

[0096] FIG. 7 illustrates a central rotatable member 24 which may be used in a system according to at least some exemplary embodiments of the present invention. The central rotatable member 24 is here illustrated as a plate or a disc, however, as mentioned previously in this disclosure other configurations are also conceivable. FIG. 7 illustrates that the periphery of the of central rotatable member is provided with an engagement portion 40, here illustrated in the form of shark-fin-shaped protrusions 42. However, as discussed elsewhere in this disclosure the engagement portion 40 may be configured in other conceivable shapes. In the illustrated example, the central rotatable member 24 comprises a circular slit 44 extending along the periphery of the central rotatable member 24. The circular slit is 44 configured to receive the cutter 38 (FIG. 5) for enabling the cutter 38 to split the continuous elongate element into two portions. However, as discussed elsewhere in this disclosure, in other exemplary embodiments the continuous elongate element may be cut laterally of the central rotatable member 24 (i.e. at either side of the central rotatable member 24), in which case the central slit 44 may suitably be omitted.

[0097] FIG. 8 illustrates the system winding a continuous elongate element onto cylindrical elements. FIG. 9 is a close-up view of details of FIG. 8. Thus, in the following, with reference to FIG. 8 and FIG. 9, the general inventive concept included in the present method and system will now be discussed.

[0098] As mentioned previously with reference to FIG. 1, the system 1 comprises a feeder 22 from which the continuous elongate element 4 may be provided to cylindrical elements 2 in consecutive order. The cylindrical elements 2 may thus be provided in the winding section 8 of the system 1 for receiving and winding the continuous elongate element 4 onto the cylindrical elements 2. In the case of the cylindrical elements being mandrels used for producing coils of the continuous elongate element 4, the same two mandrels may be reused over and over again, and thus the mandrels will alternatingly and repeatedly wind the continuous elongate element 4 (i.e. when one is fully wound, the coil is removed therefrom, while the empty one receives the continuous elongate element 4). In the current illustrations in FIG. 8 and FIG. 9, the cylindrical elements are in the form of spools. The first cylindrical element 2a has been fully winded, and the second cylindrical element 2b has started to receive the continuous elongate element 4. Thus, initially, the feeder 22 was aligned with the first cylindrical element 2a, but has in Fig.8 and FIG. 9 been displaced to become aligned with the second cylindrical element 2b. The displacement of the feeder is controlled by the control unit 20 (FIG. 1). As best seen in FIG. 9 the continuous elongate element 4 has already been wound a few rotations/laps around a cylindrical winding portion 46 of the second cylindrical element 2b.

[0099] The control unit is configured to provide the first cylindrical element 2a and the second cylindrical element 2b on respective sides of the central rotatable member 24 along the common geometrical rotational axis. This may, for example, be achieved by means of rotatable shafts and spindles such as the ones previously discussed. The control unit is also configured to rotate the first cylindrical element 2a, the second cylindrical element 2b and the central rotatable member 24 with the same rotational speed. This may, for example, be achieved by means of motors, such as the ones previously discussed.

[0100] Accordingly, to achieve the situation illustrated in FIG. 8 and FIG. 9, the control unit 20 (FIG. 1) has first aligned the feeder 22 with the first cylindrical element 2a, thereby winding the continuous elongate element 4 onto the first cylindrical element 2a by rotating the first cylindrical element 2a. Thereafter, while the first cylindrical element 2a, the second cylindrical element 2b and the central rotatable member 24 rotate, the control unit 20 has caused the feeder 22 to be displaced from being aligned with the first cylindrical element 2a to being aligned with the second cylindrical element 2b. It should be understood that once it is aligned with the second cylindrical element 2b, the feeder 22 may suitably move slightly back and forth in parallel with the geometrical rotational axis in order to better distribute the laying out of the continuous elongate element 4 over the cylindrical winding surface 46 of the second cylindrical element 2b. The displacement of the feeder 22 from the first cylindrical element 2a to the second cylindrical element 2b causes the continuous elongate element 4 to come into engagement with the engagement portion of the central rotatable member 24. As best seen in FIG. 9, one of the protrusions 42 of the engagement portion has engaged with the continuous elongate element 4. The protrusions 42 present abutment surfaces for catching the continuous elongate element 4 as the feeder 22 is moved from being aligned with the first cylindrical element 2a to being aligned with the second cylindrical element 2b (or vice versa).

[0101] After this engagement has occurred, the control unit 20 continues to rotate the second cylindrical element 2b for winding the continuous elongate element 4 from the feeder 22 onto the second cylindrical element 2b. Suitably the first cylindrical element 2a and the central rotatable member 24 continuous to rotate with the second cylindrical element 2b for a sufficient number of rotations until the winding of the continuous elongate element 4 on the second cylindrical element 2b has become self-locking.

[0102] As best seen in FIG. 9, the diameter of the central rotatable member 24 is suitably larger than the diameter of the cylindrical elements 2a, 2b. Thus, the radial distance between the common geometrical rotational axis and the engagement portion is larger than the radial distance between the common geometrical axis and a circumference of end wall portions 48 of the cylindrical elements 2a, 2b. This is beneficial as it counteracts unwinding from the first cylindrical element 2a when it rotates with the second cylindrical element 2b after the switch (displacement of the feeder 22 to the second cylindrical element 2b) has been made.

[0103] When the continuous elongate element 4 has been sufficiently secured (self-locked) to the second cylindrical element 2b, it may be cut by the cutter (shown in FIG. 5) so that the first cylindrical element 2a with its winding may be removed for further handling (e.g. transferring to the post-winding section). Thus, at this stage, as previously discussed in relation to FIG. 6, the first magnet 32a may be disconnected from the magnetic portion 36 of the central rotatable member 24 and the first rotatable shaft 28a may be retracted to remove the first cylindrical element 2a from the central rotatable member 24, which continues to rotate with the second cylindrical element 2b.

[0104] With reference again to FIG. 9, the control unit may suitably be configured to apply a roller 50 against the already winded portion of the continuous elongate element 4 before the continuous elongate element is cut, and the roller 50 may suitably be kept against the already winded portion after the continuous elongate element 4 has been cut, until the first cylindrical element 2a has decelerated sufficiently (thereby reducing the risk of the already winded portion unwinding after the cutting).

[0105] The control unit may thus suitably be configured to control the cutter 38 (FIG. 5) to cut the continuous elongate element 4 at its engagement with the engagement portion so as to split it into two portions, a first portion already wound on the first cylindrical element 2a and a second portion which is still being winded onto the second cylindrical element 2b.

[0106] The method of the present inventive concept may suitably be performed by the control unit 20. Thus, the above steps, actions, operations, etc. performed by the control unit 20 may suitably be included in the method of the present invention, including exemplary embodiments thereof.