NL2031790B1

NL2031790B1 - Stock reel, wind-up station comprising said stock reel and method for winding-up a continuous strip

Info

Publication number: NL2031790B1
Application number: NL2031790A
Authority: NL
Inventors: Johannes Catharina Van Laar Gerardus
Original assignee: Vmi Holland Bv
Priority date: 2022-05-06
Filing date: 2022-05-06
Publication date: 2023-11-14

Abstract

The invention relates to a stock reel for winding— up a continuous strip, wherein the stock reel is rotatable about a stock reel axis extending in an axial direction, wherein the stock reel comprises a winding surface concentric to the stock reel axis, wherein the winding surface has a crest and two side portions tapering away from the crest on opposite sides of said crest in the axial direction. The invention further relates to a wind—up station comprising the aforementioned stock reel and za method. for* winding—up a continuous strip on the aforementioned stock reel.

Description

P140998NLOO

Stock reel, wind-up station comprising said stock reel and method for winding-up a continuous strip

BACKGROUND

The invention relates to a stock reel, a wind-up station comprising said stock reel and a method for winding- up a continuous strip, in particular a strip for use in tire manufacturing.

WO 2018/208146 Al discloses a wind-up system with a collection reel to collect and wind-up a strip, in particular a strip comprising metal, e.g. a breaker ply. The windings of the strip are separated by a liner.

A typical collection reel may be configured to hold in excess of one-hundred or one-hundred-and-fifty meters of the strip. A disadvantage of the known collection reel is that the strip, when winding a considerable length thereof around the cylindrical core of the collection reel, tends to wrinkle or crease, in particular at the inner windings, e.g. in the first ten to fifteen meters of the strip. The inner windings of the strip often have to be discarded as they no longer meet the quality requirements for producing a tire.

Notably, the inner windings appear smooth and uniform when they are initially wound. The problem only occurs as more windings are added and more torque is generated, progressively increasing the tension in the inner windings.

The problem has therefore been treated as tension-related.

For example, JP 2019-116059 A discloses a winding device with a reel for winding a strip and a liner, and a liner delivery device for supplying the liner. The liner delivery device includes a brake device that applies a brake torque to delivery of the liner. JP 2019-116059 A acknowledges a tension decrease as the winding accumulate, causing sagging in the windings of the strip and the liner between said windings. To address this issue, a control device is provided that has a function of increasing the brake torque on the liner delivery device in response to an increase of a winding radius of the strip on the reel.

JP 2019-116059 A further discloses a feed-guide for winding the strip wound around the reel body while shifting a winding position in an axial direction of the reel body, in particular with an amplitude of ten to thirty millimeters.

In this manner, the relative thick edge cover, also known as ‘gum strips’ are shifted away from each other in the axial direction. This supposedly further suppresses deformation of the strip.

Moreover, thicker liners appear to address the problem to some extent. However, the thicker liners may cause other handling issues in the tire building process and result in a considerable increase in waste.

Thus far, the root cause of the wrinkling or creasing has been difficult to determine.

SUMMARY OF THE INVENTION

Although the known winding device disclosed in JP 2019-116059 A solves deformation of the strip to some extent, thus far, the root cause of the wrinkling or creasing has been difficult to determine.

It is an object of the present invention to provide a stock reel, a wind-up station comprising said stock reel and a method for winding-up a continuous strip, in particular a strip for use in tire manufacturing, wherein the uniformity of the continuous strip, in particular in the inner windings of said continuous strip around the stock reel, can be improved.

According to a first aspect, the invention provides a stock reel for winding-up a continuous strip, wherein the stock reel is rotatable about a stock reel axis extending in an axial direction, wherein the stock reel comprises a winding surface concentric to the stock reel axis, wherein the winding surface has a crest and two side portions at least partially recessed from the crest on opposite sides of said crest in the axial direction.

The Applicant has discovered that consecutive inner windings of the continuous strip wound around the cylindrical core of a conventional collection reel, as disclosed in WO 2018/208146 Al, tend to shift and run-off to one side of the stock reel in the axial direction as more windings are accumulated and as tension increases, causing wrinkles and/or creases in the strip, in particular when the inner windings come into contact with one of the side flanges. By providing the stock reel with a crowned winding surface, the relatively large diameter of the winding surface at the crest compared to the smaller diameter at the two side portions locally increases friction between the stock reel and the inner windings, thereby preventing that the inner windings shift and run-off to one side. The winding surface can thus have a steering or centering effect on the inner windings of the continuous strip. By keeping the inner windings centered, wrinkling and/or creasing can be prevented.

A skilled person would normally not consider providing a conventional collection reel with a crowned winding surface, because the object of a collection reel is to collect the windings as level as possible and with minimal deformation across the width of the continuous strip.

However, the Applicant has found that when the winding surface is properly dimensioned, deformation can be kept to a minimum and the steering or centering effect can be sufficiently maintained.

Moreover, when the continuous strip is a breaker ply provided with gum strips along the longitudinal edges thereof, the winding surface has the following surprising technical effects: 1) subsequent windings of the breaker ply remain centered and the gum strips associated with said windings can be stacked on top of each other rather than alongside each other, thereby reducing wrinkles and/or creases as a result of the added thickness gum strips; 2) the recessed side portions can partially compensate for the added thickness of the gum strips, at least at the inner windings, such that said inner windings can be stacked on top of each other more evenly or in an increasingly level orientation, despite the added thickness of the gum strips, thereby further reducing tension in the continuous strip; and 3) the winding surface can radially compact the inner windings of the continuous strip at the crest between the side portions to increase the contact surface between the stock reel and the breaker ply in the area between the gum strips, effectively increasing the friction at the center of said breaker ply and thus further increasing the steering or centering effect of the winding surface on the breaker ply.

In one embodiment the two side portions taper away from the crest on opposite sides of said crest in the axial direction. The taper of the two side portions can prevent any abrupt steps in the height of said two side portions relative to the crest.

In one embodiment the crest and the two side portions define a convex crown. The convex crown can smoothly transition from the crest into the side portions, thereby preventing imprints in the continuous strip as a result of the winding surface.

Alternatively, the two side portions have a straight taper in the axial direction away from the crest.

The straight taper can approximate the aforementioned convex crown as much as possible.

Preferably, the winding surface, at the crest, comprises a straight cylindrical portion. Together, the straight taper in the side portions and the straight cylindrical portion can more closely approximate the aforementioned convex crown.

In another embodiment the stock reel comprises a 5 core concentric to the stock reel axis and a winding body extending concentrically around said core, wherein the winding body defines the winding surface. The winding body can therefore have a different geometry to the core.

Preferably, the winding body is fixed against rotation about the stock reel axis relative to the core. In other words, the core and the winding body are configured to rotate together or in unison. Hence, when the stock reel is rotated, the winding body can rotate with said stock reel to take on the windings of the continuous strip.

In one embodiment the winding body comprises a shell that is fitted around the core. The shell can be provided in one or more parts separate from the stock reel, for example for retro-fitting or converting a conventional collection reel to the stock reel according to the present invention. The shell may be exchanged for alternative shells having a different geometry.

In a further embodiment the shell is rigid. The shape of the shell can therefore reliably define the shape or contour of the winding surface.

In a further embodiment the shell comprises two or more arc segments that together form the winding body.

Dividing the shell into two or more arc segments may facilitate removal and fitting of the winding body in an annular manner to a conventional collection reel.

In a further embodiment the two or more arc segments are arranged to be interconnected. By interconnecting the two or more arc segments, the shell can be effectively retained around the core.

In an alternative embodiment the winding body is formed by one or more layers of flexible material wound around the core prior to winding the continuous strip. In contrast to the aforementioned rigid shell, the flexible material can be applied around the core by winding. The flexible material may for example be provided with a cross section corresponding to the desired cross section of the winding body.

Alternatively, several layers with decreasing widths may be stacked on top of each other to build the desired cross section layer by layer. The flexible material may have a friction coefficient sufficient to prevent relative rotation between the core and the flexible material about the stock reel axis. The flexible material may for example comprise vulcanized rubber.

Preferably, each layer of the one or more layers of flexible material is fixed end-to-end to itself or another one of the one or more layers. The fixation ensures that the flexible material does not detach from the core prior to winding the continuous strip.

In another embodiment the core is straight cylindrical. Such a core is for example similar to the core of a conventional collection reel. The winding body may thus be retrofitted to said core. The core may for example be optimized for mounting the stock reel on a shaft of a wind- up or unwind station.

In a further alternative embodiment the winding body is integrally connected to the core. Hence, the winding body and the core can be virtual sections of a single, integral body, i.e. a body without material transitions.

In another embodiment the winding surface has a first diameter at the crest and a second diameter, smaller than the first diameter, at the two side portions, wherein the difference between the first diameter and the second diameter is at least five millimeters and preferably at least ten millimeters. Such a difference can be sufficient to provide the aforementioned steering or centering effect.

Moreover, such a difference can be sufficient to support a breaker ply between the gum strip at the longitudinal sides thereof, thereby increasing the contact area between the breaker ply and the winding surface. An increased contact area means more friction, and thus an increased steering or

: centering effect.

Preferably, the difference between the first diameter and the second diameter is less than thirty millimeters and preferably less than twenty millimeters. By keeping the difference below the specified amounts, it can be prevented that the winding surface excessively deforms the continuous strip.

In another embodiment the stock reel further comprises two side flanges extending radially with respect to the stock reel axis on opposite sides of the winding surface in the axial direction. The side flanges protect the windings of the continuous strip on the stock reel and allow for said stock reel to be stored on or rolled over a floor.

In another embodiment the crest is located in a center of the winding surface considered in the axial direction. Hence, the inner windings can be centered and/or aligned relative to or towards said center.

According to a second aspect, the invention provides a wind-up station comprising the stock reel according to any one of the embodiments of the first aspect of the invention. The wind-up station includes the aforementioned stock reel and thus has the same technical advantages, which will not be repeated hereafter.

Preferably, the wind-up station further comprises a liner reel and a liner reel brake for applying brake torque to the liner reel. The liner reel brake can be controlled to slow down the liner reel during the winding-up of the continuous strip on the stock reel.

More preferably, the wind-up station comprises a control unit that is operationally connected to the liner reel brake for reducing the brake torque as windings of the continuous strip accumulate on the winding surface. By reducing the brake torque as the windings accumulate, it can be prevented that an increasingly higher tension is generated in the liner at the inner windings. An increase of tension in the liner at the inner windings may cause further tightening, tension buildup and shifting between the inner windings and said liner, which may lead to the aforementioned wrinkling or creasing.

Most preferably, the control unit is configured for reducing the brake torque non-linearly, preferably according to a parabolic curve. A linear reduction of the brake torque linearly can be used to keep the tension in the liner constant in the length of said liner between the liner reel and the stock reel. However, the Applicant has discovered that linearly decreasing the brake torque may still result in a progressive increase of tension in the liner at the inner windings as more and more windings are wound onto the stock reel. Based on a study of the actual physics of the stock reel, the Applicant has found that by reducing the brake tordue non-linearly, in particular according to a parabolic curve, the tension in the liner at the inner windings can be kept constant or substantially constant as more windings are accumulated on the stock reel.

According to a third aspect, the invention provides a method for winding-up a continuous strip on a stock reel according to any one of the embodiments of the first aspect of the invention, wherein the method comprises the step of: - winding the continuous strip on the winding surface.

The method relates to the practical implementation of the aforementioned stock reel during the winding of the continuous strip and therefore has the same technical advantages, which will not be repeated hereafter.

In one embodiment the continuous strip is a breaker ply for tire building.

Preferably, the breaker ply has two longitudinal edges, wherein gum strips are applied to the breaker ply along said longitudinal edges.

More preferably, the method comprises the steps of: - winding the continuous strip in a plurality of windings about the stock reel; - supporting the gum strips on the two side portions of the winding surface; and

- radially compacting at least two of the innermost windings of the plurality of windings at the crest of the winding surface between the gum strips.

In a further embodiment the breaker ply is provided with a liner for separating consecutive windings of said breaker ply.

In one embodiment the stock reel comprises a core concentric to the stock reel axis, wherein the method comprises the step of: - arranging a winding body concentrically around said core, wherein the winding body defines the winding surface.

Preferably the winding body comprises a shell, wherein the method comprises the step of: - fitting the shell around the core.

In an alternative embodiment the winding body is formed by one or more layers of flexible material, wherein the method comprises the step of: - winding the one or more layers of flexible material around the core prior to winding the continuous strip.

In another embodiment the method comprises the steps of: - providing a liner between the plurality of windings; - providing a liner reel for supplying the liner to the stock reel; - applying brake torque to the liner reel during unwinding of the liner; and - reducing the brake torque as windings of the continuous strip accumulate on the winding surface.

Preferably, the brake torque is reduced non- linearly, preferably according to a parabolic curve,

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which: figure 1 shows a cross section of a conventional collection reel according to the prior art with a continuous strip wound in a plurality of windings around said conventional collection reel; figure 2 shows a detail of the conventional collection reel of figure 1 with a large number of windings; figure 3 shows a top view of the conventional collection reel according to figure 1 with wrinkling the inner windings of the continuous strip; figure 4 shows a cross section of a stock reel according to a first exemplary embodiment of the invention; figure 5 shows a detail of the stock reel according to figure 4 with the continuous strip wound in a plurality of windings around said stock reel; figure 6 shows a detail of an alternative stock reel according to a second exemplary embodiment of the invention; figure 7 shows a side view of the conventional collection reel according to figure 1 and a winding body for retrofitting said conventional collection reel; figure 8 shows a side view of the conventional collection reel according to figure 1 and an alternative winding body for retrofitting said conventional collection reel; figure 9 shows a side view of a wind-up station comprising the stock reel according to figure 4 and a liner reel; and figure 10 shows a graph for controlling brake torque applied to the liner reel of figure 9 during the winding of the continuous strip around said stock reel.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1, 2 and 3 show a conventional stock reel or collection reel 201 according to the prior art. The conventional collection reel 201 is used to collect and/or store a continuous length of stock material, in this example a continuous strip 9 for tire building. More in particular, the continuous strip 9 is a breaker ply 90 which is provided with gum strips 91, 92 at the sharp longitudinal sides thereof. The breaker ply 90 comprises unvulcanized elastomeric material with embedded reinforcement cords (not shown) extending under an oblique angle to the longitudinal direction of the breaker ply 90.

The conventional collection reel 201 is rotatable about a stock reel axis S extending in an axial direction A.

The collection reel 201 further comprises a core 2 concentric to the stock reel axis S. In this example, the core 2 is straight cylindrical or defines a straight cylindrical, circumferential core surface 20. As best seen in figures 1 and 3, the collection reel 201 further comprises a first side flange 31 and a second side flange 32 extending radially or in a radial direction R perpendicular to the stock reel axis

S. In particular, the side flanges 31, 32 extend on opposite sides of the circumferential core surface 20 in the axial direction A.

The continuous strip 9 is wound onto the conventional collection reel 201 around the circumferential core surface 20 over a plurality of windings. Typically, lengths in excess of one-hundred or one-hundred-and-fifty meters are stored on the conventional collection reel 201.

The windings are separated by a liner 8 to prevent that the strip 9 adheres to itself between the windings.

For clarity reasons, figures 1, 2 and 3 only depict a limited number of windings of the continuous strip 9 are shown. Moreover, some dimensions of the continuous strip have been exaggerated and some of the windings may appear to be floating to clearly distinguish the windings of the continuous strip 9 and the liner 8 from each other. It will however be understood that, in practice, the windings of the continuous strip 9 and the liner 8 are in mutual contact and/or tightly packed in the radial direction R.

As shown in figure 1, when the continuous strip 9 is a breaker ply 90, the added thickness of the gum strips 91, 92 contributes to a slacking of the continuous strip © in the subsequent windings after the initial winding. Due to said slacking, the gum strip 91, 92 experience less friction towards the center of the breaker ply 90 and the windings are therefore more likely to run-off to one side, in particular as more windings are accumulated and tension increases.

Figure 2 shows the resulting stack of windings, in which the inner windings of the continuous strip 9 have run- off to one side until the liner 8 between the windings starts to contact one of the side flanges 31, 32. Subsequent windings are wound while the growing stack leans against said one side flange 31, 32.

Figure 3 shows a length of the continuous strip 9 corresponding to the inner windings of said continuous strip 9 that is unwound from the collection reel 201. The unwound length of the continuous strip 9 has significant creases or wrinkles W, rendering the unwound length unsuitable for use in tire building. This section of the continuous strip 9 is therefore cut off by an operator and discarded as waste.

It has been observed in practice that the wrinkles

W generally or predominantly extend in an oblique direction matching the oblique angle of the reinforcement cords (not shown) in the breaker ply 90.

Figure 4 shows a collection reel or stock reel 1 according to a first exemplary embodiment of the present invention. The stock reel 1 of figure 4 differs from the conventional collection reel 201 in figure 1 in that it comprises or is provided with a winding surface or a crowned winding surface 40. Said winding surface 40 extends concentric to the stock reel axis S. The winding surface 40 has a crest C. In this example, the crest C is located at half distance between the two side flanges 31, 32. In particular, the crest C is located in the center of the winding surface 40 considered in the axial direction A. The winding surface 40 further has a first side portion S1 and a second side portion S2 tapering away from the crest C on opposite sides of said crest C in the axial direction A. In this example, the crest C and the two side portions S1, S2 define a convex crown, i.e. a smoothly curved or arcuate surface without abrupt transitions. Preferably, the side portions S1, S2 are symmetrical.

The winding surface 40 has a first diameter D1 at the crest C and a second diameter D2, smaller than the first diameter D2, at the two side portions S1, S2. In this example, the difference between the first diameter D1 and the second diameter D2 is approximately thirty millimeters.

In other words, the winding surface 40 has an area at or including said crest C that has an average diameter that is larger than the average diameter of the side portions

S1, s2.

As further shown in figure 4, the stock reel 1 comprises or is provided with a winding body 4 that is applied to and/or extends concentrically around the core 2. The winding body 4 defines the winding surface 40. In this example, the winding body 4 is a separate part that is distinct from the core 2, as also reflected by the different hatchings in figure 4. Said winding body 4 may be mounted to the conventional collection reel 201 of figure 1 to retrofit or convert said conventional collection reel 201 to the stock reel 1 according to the present invention.

However, in an alternative embodiment (not shown) the winding body 4 may be integrally connected to the core 2 or an integral part of said core 2, i.e. not a retrofit part.

In other words, the winding body 4 may form a single,

continuous or uninterrupted body with the core 2. In that case, the hatchings of the winding body 4 and the core 2 would be the same or continuous.

As shown in more detail in figure 5, the inner windings of the continuous strip 9 can be wound onto the stock reel 1 around the winding surface 40 while the ‘crown’ of the winding surface 40, i.e. its raised crest C, still showing in said inner windings. In other words, the inner windings of the continuous strip 9 are crowned to some extent as a result of the support on the winding surface 40.

Figure 6 shows an alternative stock reel 101 according to a second exemplary embodiment of the present invention, which differs from the aforementioned stock reel 1 of figures 4 and 5 in that it has an alternative winding body 104 that defines an alternative winding surface 140 having two side portions $101, S102 tapering linearly or in a straight taper in the axial direction A away from the crest

C. In this example, the alternative winding surface 140 further comprises a straight cylindrical portion D at the crest C, i.e. between the two side portions S101, S102.

Figure 7 shows the conventional collection reel 201 of figure 1 as 1t is being retrofitted with an alternative winding body 204. The alternative winding body 204, in cross section, has the same winding surface 40, 140 as in figure 5 or 6. The alternative winding body 204 is divided into two arc segments 241, 242 that together form a shell 243. The two arc segments 241, 242 are arranged to be interconnected, for example by matching connections at the opposing, terminal ends thereof. By interlocking the arc segments 241, 242, the shell 243 can be fitted around the core 2 to form or define the alternative winding body 204. In this example, the shell 243 is rigid or substantially rigid.

The alternative winding body 204 is fixed against rotation about the stock reel axis S relative to the core 2.

In particular, one of the arc segments 241, 242 is provided with a shell fixation member 244 that can engage with a corresponding stock reel fixation member 234, for example as a male-female connection, more in particular a pin and a hole.

In this example, the shell fixation member 244 engages with the stock reel fixation member 234 at one of the side flanges 31, 32. Alternatively, the shell fixation member 244 engages with the stock reel fixation member 234 may engage each other at or near the core 2.

Figure 8 shows the conventional collection reel 201 of figure 1 as it is being retrofitted with a further alternative winding body 304. The further alternative winding body 304 is formed by a layer of flexible material 341 that, contrast to the aforementioned shell 243, is wound around the core 2. The flexible material 341 is provided with a cross section that defines one of the aforementioned winding surfaces 40, 140. The layer of flexible material 341 is fixed end-to-end to itself using a suitable end connector 342, for example a staple or a clamp.

Alternatively, several layers of the flexible material 341 are stacked on top of each other with a decreasing width for each subsequent layer in order to build the desired cross section layer by layer.

The flexible material 341 preferably has a friction coefficient sufficient to prevent relative rotation between the core 2 and the flexible material 341 about the stock reel axis S. Hence, a separate fixation member would not be necessary. In this example, the flexible material 341 comprises vulcanized rubber.

A method for winding-up a continuous strip 9 on the aforementioned stock reel 1, 101, 201 will be elucidated hereafter with reference to figures 5, 6 and 9.

Optionally, the method may start with retrofitting the conventional collection reel 201 with one of the previously discussed winding bodies 4, 104, 204, 304.

Alternatively, a stock reel 1 may be provided which already incorporates the winding body 4, 104.

As shown in figure 5 and 6, the continuous strip © is wound in several windings onto or around the winding surface 40, 140. Note that the inner windings, in this example the initial four windings, of the continuous strip 9 are supported in a way that the parts of said inner windings extending over the crest C of the winding surface 40, 140 are located radially more outwards than the parts of said inner windings that extend over the side portions S1, S2; S101,

S102. In other words, the inner windings of the continuous strip 9 for a crowned support surface themselves for subsequent windings. The crowning of the inner windings may decrease progressively with each subsequent winding. For example, the fifth winding in figure 5 is almost level and the sixth winding is level.

Consequently, the inner windings of the continuous strip 9 extend around the crest C of the winding surface 40, 140 at a larger diameter compared to the diameter of the longitudinal sides of the same windings of said continuous strip 8 at the respective side portions S1, S2; S101, S102.

Hence, more friction is generated at the crest C than at the side portions S81, 35; 8101, 35102, thereby urging the continuous strip 9 to remain centered, at least at the inner windings thereof. Hence, the winding surface 40, 140 can have a steering, centering or aligning effect on the inner windings. By keeping the inner windings of the continuous strip 9 «centered, wrinkling and/or creasing can be prevented.

As mentioned before, in this example, the continuous strip 9 is a breaker ply 90 that is provided with gum strips 91, 932 along the longitudinal sides thereof. The gum strips 91, 92 are stacked and/or supported on the two side portions S1, S2; S101, S102 of the winding surface 40, 140. The part of the breaker ply 90 extending between the gum strips 91, 92 is supported and/or radially compacted by the relative large diameter Dl (see figure 4) at the crest C of the winding surface 40, 140. More in particular, the inner windings of the breaker ply 90 and the liner 8 therein between may be condensed and/or touching. Hence, the contact surface between the winding surface 40, 140 and the initial winding, or between the windings and/or the liner 8, can be increased in the area between the gum strips. This effectively increases the friction at the center of said breaker ply and thus increases the steering or centering effect of the winding surface 40, 140 on the breaker ply 90.

The relatively small diameter D2 (see figure 4) at the two side portions S81, S2; S101, S102 can at least partially compensate for the added thickness of the gum strips 91, 92 in the sense that at least the first few inner windings remain convexly crowned, as shown in figures 5 and 6, instead of concave, as shown in the prior art of figure 1. In other words, the gum strips 91, 92 of the first few windings are recessed by the two side portions S1, S2; S101, S102 compared to the raised crest C and therefore remain below the level of the crest C, at least for the first few windings of the continuous strip 9.

Figure 9 shows a wind-up station comprising the aforementioned stock reel 1 and a liner reel 80 for supplying the liner 8 to the stock reel 1. The wind-up station further comprises a liner reel brake 81 for applying a brake torque to and/or slowing down the liner reel 80 and a control unit 6 that is operationally, functionally and/or electronically connected to the liner reel brake 81 to control said liner reel brake 81. The liner reel brake 81 may for example be an electric brake, more in particular an Eddy current brake. The wind-up station further comprises a travel sensor or a length sensor 82, for example an encoder, for detecting the length of liner 8 and/or the length of the continuous strip 9 passing a certain point in the wind-up station.

Figure 10 shows a graph of controlling the brake torque T in Newton meters that is applied by the liner reel brake 81 on the liner reel 80 as a function of the length X in meters of the liner 8 or the continuous strip 9 that is wound on the stock reel 1, 101, 201. As more windings of the continuous strip 9 accumulate on the stock reel 1, 101, 201, the weight of the stock reel 1, 101, 201 and the windings increases and the load on the stock reel brake 5 and/or the liner 8 increases. If the brake torque T is of the stock reel brake 5 is kept constant, tension in the liner 8 at the inner windings of the continuous strip 9 progressively increases as more windings are accumulated around said inner windings.

In one embodiment of the method, the brake torque

T is reduced linearly, as shown by the dashed line L, which at least partially compensates for the aforementioned tension increase in the liner 8 at the inner windings. However, the

Applicant has discovered that linearly decreasing the brake torque T may still result in an increase of the tension in the liner 8 at the inner windings, in particular when the continuous strip 9 is a breaker ply 20 with gum strips 91, 92. Based on a careful study of the actual physics of winding the breaker ply 90 with gum strips 91, 92 on the stock reel 1, 101, 201, the Applicant has found that by reducing the brake torque T non-linearly, the tension in the liner 8 at the inner windings can be kept constant or substantially constant. In particular, the brake torque T should be reduced according to a parabolic function, as shown by the parabolic curve P in figure 9.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.

LIST OF REFERENCE NUMERALS

1 stock reel 2 core 20 circumferential core surface 31 first side flange 32 second side flange 4 winding body winding surface 6 control unit

8 liner 80 liner reel 81 liner reel brake 82 length sensor 9 continuous strip 90 breaker ply 91 first gum strip 92 second gum strip 101 alternative stock reel 104 alternative winding body 201 conventional collection reel 234 stock reel fixation member 204 further alternative winding body 241 first arc segment 242 second arc segment 243 shell 244 shell fixation member 304 further alternative winding body 341 flexible material 342 end connector

A axial direction

C crest

D straight cylindrical portion

S stock reel axis

S1 first side portion

S2 second side portion

S101 alternative first side portion

S102 alternative second side portion

T brake torque

W wrinkles

X length

Claims

CONCLUSIONS

1. Supply reel (1, 101, 201) for winding up a continuous strip (9), wherein the supply reel (1, 101, 201) is rotatable about a supply reel axis (S) extending in an axial direction (A), wherein the supply reel (1, 101, 201) comprises a winding surface (40, 140) concentric to the supply reel axis {S), the winding surface (40, 140) having a top (C) and two side portions (S1, S2; S101, 5102) that are at least partially set back from the apex (C} on opposite sides of the apex (C) in the axial direction (A).

A supply reel (1, 201) according to claim 1, wherein the two side portions {({S1, S2; S101, S102) slope away from the top (C) on opposite sides of the top (C) in the axial direction (A ).

3. Stock reel {1, 201) according to claim 1 or 2, wherein the top (C) and the two side portions (S1, S2) form a convex crown.

A supply reel (101) according to claim 1 or 2, wherein the two side portions (S101, S102) have a straight slope in the axial direction (A) away from the top (C).

A supply reel (101) according to claim 1 or 2, wherein the winding surface (140), at the top (C), comprises a straight cylindrical portion (D).

6. Stock reel (1, 101, 201) according to any one of the preceding claims, wherein the stock reel (1, 101, 201) comprises a core (2) that is concentric to the stock reel axis (S) and a winding body (4, 104, 204 , 304) that extends concentrically around the core, with the winding body (4, 104, 204, 304) defining the winding surface (40, 140).

A supply reel (201) according to claim 6, wherein the winding body (204) is fixed against rotation about the supply reel axis (S) relative to the core

(2).

A supply reel (201) according to claim 6 or 7, wherein the winding body (204) comprises a shell (243) placed around the core (2).

A supply reel (201) according to claim 39, wherein the shell (243) is rigid.

A supply reel (201) according to claim 8 or 9, wherein the shell (243) comprises two or more arc segments (241, 242) that together form the winding body {204}.

A supply reel (201) according to claim 10, wherein the two or more arc segments (241, 242) are arranged to be interconnected,

A supply reel (201) according to claim 6, wherein the winding body (304) is formed by one or more layers of a flexible material (341) wrapped around the core (2) prior to winding the continuous strip

(9).

The supply reel (201) of claim 12, wherein each layer of the one or more layers of flexible material (341) is end-to-end fixed to itself or another of the one or more layers.

14. Stock reel (1, 101, 201) according to any one of claims 6-13, wherein the core (2) is straight-cylindrical.

15. Stock reel (1) according to claim 6, wherein the winding body (4) is integrally connected to the core (2).

A supply reel (1, 101, 201) according to any one of the preceding claims, wherein the winding surface {40, 140) has a first diameter (D1) at the apex (C) and a second diameter (D2) smaller than the first diameter (D1), at the two side portions (S1, S2; S101, S102), the difference between the first diameter (D1) and the second diameter (D2) being at least ten millimeters and preferably at least twenty millimeters.

17. Stock reel (1, 101, 201) according to claim 16, wherein the difference between the first diameter (D1) and the second diameter (D2) is less than fifty millimeters and preferably less than thirty millimeters.

A supply reel (1, 101, 201) according to any one of the preceding claims, wherein the supply reel (1, 101, 201) further comprises two side flanges (31, 32) extending radially with respect to the supply reel centerline (S) on opposite sides of the winding surface (40, 140) in the axial direction (A).

19. Stock reel (1, 101, 201) according to any one of the preceding claims, wherein the top (C) is located in a center of the winding surface (40, 140) viewed in the axial direction (A).

20. Winding station comprising the supply reel (1, 101, 201) according to any one of the preceding claims.

The winding station of claim 21, wherein the winding station further comprises a liner reel (80) and a liner reel brake (81) for applying a braking torque (T) to the liner reel (80).

A winding station according to claim 21, wherein the winding station comprises a control unit (6) operatively connected to the liner reel brake (81) for realizing the braking torque (T} while the windings of the continuous strip (9) build up on the winding surface (40, 140).

23. Winding station according to claim 22, wherein the control unit (6) is configured to linearly reduce the braking torque (T), preferably according to a parabolic curve (P).

24. Method for winding a continuous strip (9) on a supply reel (1, 101, 201) according to any one of claims 1-19, wherein the method comprises the steps of: - winding the continuous strip (9) on the winding surface (40, 140).

Method according to claim 24, wherein the continuous strip (9) is a belt ply (90) for tire building.

Method according to claim 25, wherein the belt layer (90) has two longitudinal sides, wherein eraser strips (91, 92) are arranged on the belt layer (90) along the longitudinal edges.

A method according to claim 26, wherein the method comprises the steps of: - winding the continuous strip (9) in a plurality of windings around the supply reel (1, 101, 201); - supporting the eraser strips (91, 92) on the two side portions {S1, S2; S101, 5102) of the winding surface (40, 140); and - radially compressing at least two of the innermost coils of the plurality of coils on the top (C) of the coil surface (40, 140) between the eraser strips (91, 92).

A method according to any one of claims 25-27, wherein the belt layer (90) is provided with a liner (8) for separating successive windings of the belt layer (90).

29. Method according to any one of claims 24-28, wherein the supply reel (201) comprises a core (2) concentric to the supply reel axis, wherein the method comprises the steps of: - arranging the winding body (204, 304) concentrically around the core, wherein the winding body (204, 304) defines the winding surface (40, 140).

A method according to claim 29, wherein the winding body (204) comprises a shell (243), the method comprising the steps of: - placing the shell (243) around the core

(2).

Method according to claim 29, wherein the wrapping body (304) is formed by one or more layers of flexible material (341), the method comprising the steps of: - wrapping the one or more layers of flexible material (341); around the core (2) prior to winding the continuous strip (9).

A method according to any one of claims 24-31, wherein the method comprises the steps of: - providing a liner (8) between the plurality of windings; - providing a liner reel (80) for supplying the liner (8) to the supply reel (1, 201); - applying a braking torque (T) to the liner reel (80) during unwinding of the liner (8); and - reducing the braking torque (T) while the windings of the continuous strip (9) build up on the winding surface (40, 140).

Method according to claim 32, wherein the braking torque (T) is reduced non-linearly, preferably according to a parabolic curve (P). -0-70-0-70-70-0-0-0-