Method, extruder device and tire building machine for winding a strip around a strip-winding drum to form a tire component

Abstract

The invention relates to Method for winding a strip in a plurality of windings around a strip-winding drum to form a tire component, wherein the method comprises the steps of: - extruding the strip in a feeding direction with the use of an extruder device, wherein the extruder device comprises a die that shapes the strip, wherein the die, considered in a cross section in a die plane perpendicular to the feeding direction, defines a die opening with a die width in a width direction parallel to the die plane, wherein the die width is adjustable; - adjusting the die width of the die opening during extrusion of the strip; and - winding the strip around the strip-winding drum. The invention further relates to an extruder device and a tire building machine comprising said extruder device and a strip-winding drum.

Description

[0001] Method, extruder device and tire building machine for winding a strip around a strip-winding drum to form a tire component

[0002] BACKGROUND

[0003] The invention relates to a method, an extruder device and a tire building machine for winding a strip around a strip-winding drum to form a tire component .

[0004] JP 4904049 B2 discloses a molding device for spirally wrapping a ribbon-shaped unvulcanized rubber strip around a cylindrical drum to form a rubber member for a tire . The molding device comprises a rubber extruder having an extruder head with a mouthpiece for preforming the rubber strip . The molding device is further provided with a calender machine that rolls the rubber into its final cross-sectional shape . The calender machine comprises a pair of opposing calender rolls and a gap adj ustment means that is controlled at a predetermined timing by a controller to adj ust the gap between the calender rolls during the spiral wrapping of the rubber strip . With the gap adj ustment means , the thickness of the rubber strip can be locally increased or decreased in the tire circumferential direction to improve the uniformity of the rubber member to be formed, in particular when there is a step in the windings as a result of a splice in an underlying layer .

[0005] According to JP 4904049 B2 , the thickness and width of the rubber strip are not particularly limited, but if they are too small , the strength of the rubber strip may decrease and break during winding . SUMMARY OF THE INVENTION

[0006] In some strip-winding patterns , it may be beneficial to not only adj ust the thickness , but also or alternatively adj ust the width, or the cross-sectional shape as a whole .

[0007] By adj usting the gap between the calender rolls in JP 4904049 B2 , the known molding device is configured for causing controlled flattening of a freshly formed rubber strip to a desired thickness . As the volume of the freshly formed rubber strip remains substantially the same after it has left the extruder head, the flattening to the desired thickness has the side-ef fect that the width is increased in an uncontrolled or undefined manner . In particular, JP 4904049 B2 does not provide any means for accurately controlling the width, or the cross-sectional shape of the rubber strip as a whole . Consequently, the molding device known from JP 4904049 B2 is not optimally configured and / or controlled for strip-winding with high accuracy and / or for obtaining a tire component with high quality .

[0008] It is an obj ect of the present invention to provide a method, an extruder device and a tire building machine for strip-winding a strip around a strip-winding drum to form a tire component , wherein the accuracy of the strip-winding and / or the quality of the tire component can be improved .

[0009] According to a first aspect , the invention provides a method for winding a strip in a plurality of windings around a strip-winding drum to form a tire component , wherein the method comprises the steps of : extruding the strip in a feeding direction with the use of an extruder device , wherein the extruder device comprises a die that shapes the strip, wherein the die , considered in a cross section in a die plane perpendicular to the feeding direction, defines a die opening with a die width in a width direction parallel to the die plane , wherein the die width is adj ustable ; adj usting the die width of the die opening during extrusion of the strip ; and winding the strip around the strip-winding drum .

[0010] By varying the width of the die opening during the extrusion of the strip, the amount or volume of elastomeric material that leaves the extruder device through the die in the width direction can ef fectively be varied, restricted or increased, thereby directly af fecting the width of the strip that is formed and ultimately wound around the stripwinding drum, without requiring further deformation or adj ustment of the strip width after the strip has been extruded . By adj usting the die width, the width of the strip that is formed by the die can be controlled more accurately . Hence , the accuracy of the strip-winding and / or the quality of the tire component can be improved . In particular, the ability to vary the strip width strategically and / or locally may conveniently be used to prevent or reduce excess material , such as excess thickness as a result of overlapping layers and / or excess width as a result of 'dogears ' , at the start or end of the winding of the strip, to increase the accuracy of the strip-winding where necessary by winding the strip in relatively narrow windings and / or to increase the ef ficiency of the winding by winding the strip in relatively wide windings where accuracy is less important .

[0011] In one embodiment the die width is adj usted steplessly . The stepless adj ustment allows for the die width to be adj usted to any width value required by the stripwinding pattern, thereby improving the accuracy of the stripwinding and ultimately the quality of the tire component .

[0012] In another embodiment the method further comprises the step of : increasing the die width for a first section of the strip corresponding to a leading tip of a first winding of the plurality of windings .

[0013] When helically or spirally winding a strip to form a tire component , the leading tip of the first winding typically forms a 'dog-ear' as it at least partially sticks out from the desired lateral edge or contour of the tire component . Alternatively, any excess material may be tugged in underneath subsequently applied layers , thereby causing a local thickness increase at the overlap with subsequently applied layers . By increasing the die width during the forming of the leading tip of the first winding, the leading tip can start relatively small and can subsequently be increased in width, thereby forming a triangular or an at least partially triangular section that potentially reduces excess material at the start of the winding .

[0014] Moreover, by increasing the die width at the start of the winding, the flow channel and / or the die opening can be filled gradually and / or in a controlled manner with elastomeric material , resulting in a more accurately shape leading tip, compared to a static die opening that may already release some of the elastomeric material early when the flow channel and / or the die opening has not yet been completely filled, resulting in a more erratic shape of the leading tip .

[0015] Preferably, the die width is increased starting from a minimum width value of less than one millimeter, preferably less than hal f a millimeter and most preferably zero millimeters . By setting the minimum width value to or close to zero millimeters , the leading tip of the strip can be started in a stepless or almost stepless manner, thereby significantly reducing excess material at the location of the leading tip .

[0016] In another embodiment the die width is increased from a non- zero minimum width value to a maximum width value that is greater than the non- zero minimum width value by a factor of at least two , preferably at least five and most preferably at least ten . Although relatively narrow windings may provide increased accuracy o f the strip-winding, more windings are required to wind the same volume of the tire component . By varying the die width between the non- zero minimum width value and the maximum width value , the strip width can be reduced to increase the accuracy of the stripwinding where necessary, while the strip width can be increase signi ficantly to improve the ef ficiency of the winding where accuracy is less important .

[0017] In another embodiment the die width is increased from a minimum width value to an intermediate width value at a first rate , wherein the die width is increased from the intermediate width value to a maximum width value at a second rate di f ferent from the first rate . The di f ferent rates may be used to alter the way in which the strip width reaches a certain width . Preferably, the second rate is slower than the first rate . In this way, the strip width can be increased initially at a higher rate to rapidly build up to a strip width at which the strip is relatively strong or stable and does not tear easily . This is particularly convenient at the leading tip of the strip, as this leading tip is the first part of the strip that is trans ferred to the strip-winding drum . Having a more rapid increase of the strip width at said leading tip can ensure that the leading tip is suf ficiently strong or stable to be accurately trans ferred onto the strip-winding drum . The strip width of the part of the strip behind the leading tip can be increase more slowly towards the maximum width value , because the leading tip has been applied onto the strip-winding drum already .

[0018] In another embodiment the die width is increased at least partially at a linear rate . Hence , the strip width can be increased gradually and / or linearly, without any abrupt changes during said gradual or linear increase .

[0019] In another embodiment the method further comprises the step of : reducing the die width for a second section of the strip corresponding to a trailing tip of a last winding of the plurality of windings . Similar to the leading tip of the first winding, the trailing tip of the last winding typically generates excess material at the desired lateral edge or contour of the tire component . By decreasing the die width during the forming o f the trailing tip of the last winding, the trailing tip can start relatively small and can subsequently be increased in width, thereby forming a triangular or an at least partially triangular section that potentially reduces excess material at the end of the winding .

[0020] Preferably, the die width is decreased to a minimum width value of less than one millimeter, preferably less than hal f a millimeter and most preferably zero millimeters . By setting the minimum width value to or close to zero millimeters , the trailing tip of the strip can be terminated in a stepless or almost stepless manner, thereby significantly reducing excess material at the location of the trailing tip .

[0021] In another embodiment the method further comprises the step of : varying the die width for one or more intermediate windings of the plurality of windings between a first winding and a last winding of the plurality of windings . Consequently, said intermediate windings can have varying strip widths to favor accuracy over ef ficiency or vi ce versa, as previously discussed .

[0022] In another embodiment the die width is adj usted symmetrically in the width direction . The symmetrical increase allows for a symmetrical distribution of the flow of elastomeric material across the die width, thereby reducing any negative ef fects of an asymmetric distribution .

[0023] In another embodiment the die has two lateral sides that define the die width of the die opening in the width direction, wherein the method further comprises the step of : generating a relative movement between the strip-winding drum and the extruder device in the width direction in response to and / or simultaneously with the adj ustment of the die width to at least partially compensate for a shi ft of one lateral side of the two lateral sides in said width direction during the adj ustment of the die width . Said one lateral side can therefore be maintained in more or less the same axial or lateral position relative to the strip-winding drum, despite the variation in die width . Ef fectively, this means that the other lateral side shi fts in the axial or lateral direction over a distance corresponding to substantially the entire adj ustment of the die width . In other words , in the event of a symmetrical adj ustment of the die width, the strip width can be adj usted relative to the strip-winding drum predominantly in one direction, or asymmetrically . In particular, this allows for at least one lateral edge of the strip to remain in the same axial or lateral position, while the other lateral edge shi fts . This may be convenient when forming the leading tip or the trailing tip of the strip, which can be formed so as to have a substantially right-triangular shape .

[0024] Preferably, the relative movement between the strip-winding drum and the extruder device is equal to hal f of the adj ustment of the die width . In other words , when the die width is adj usted symmetrically, the relative movement equaling hal f of the adj ustment of the die width can result in said one lateral side being maintained in more or less the same axial or lateral position relative to the stripwinding drum, with the aforementioned advantages .

[0025] In another embodiment the die opening has a die height in a height direction parallel to the die plane and perpendicular to the width direction, wherein the die height is adj ustable , wherein the method further comprises the step of : adj usting the die height of the die opening during the extrusion of the strip . By adj usting the die height as well , the amount or volume of elastomeric material that leaves the extruder device through the die in the height direction can ef fectively be varied, restricted or increased, thereby directly af fecting the height of the strip that is formed without requiring further deformation or adj ustment of the strip width after the strip has been extruded . By adj usting the die height , the height of the strip that is formed by the die can be controlled more accurately .

[0026] Preferably, the die height is adj usted simultaneously with the adj ustment of the die width . Hence , not only the strip width, but the overall shape or contour of the strip can be adj usted .

[0027] In another embodiment the die height is adj usted steplessly . The stepless adj ustment allows for the die height to be adj usted to any height value required by the stripwinding pattern, thereby improving the accuracy of the stripwinding and ultimately the quality of the tire component .

[0028] In another embodiment , that can be applied independently of the aforementioned individual adj ustments of the die width or the die height , the die opening has a cross-sectional area that is adj ustable from a minimum cross-sectional area value up to a maximum cross-sectional area value , wherein the minimum cross-sectional area value is zero , wherein the method comprise the step of : adj usting the cross-sectional area of the die opening during extrusion of the strip and using the minimum cross-sectional area value at least once during said adj ustment . Notably, JP 4904049 B2 discloses that the adj ustment range of the thickness of the rubber strip should be limited to a minimum thickness of three tenths of a millimeter to prevent breaking of the rubber strip . The minimum thickness is suf ficient for at least partially absorbing steps as a result of splices in underlying layers . However, JP 4904049 B2 fails to acknowledge that there may also be a benefit to locally reducing the width and thickness of the rubber strip in the underlying layers , and thereby preventing any steps in the first place . This is particularly relevant for the leading tip of the first winding or the trailing tip of the last winding . By using the zero cross- sectional area value at least once during the adj ustment , one or more windings of the strip can be started or terminated steplessly or almost steplessly during the winding at strategic places in a strip-winding pattern . In particular, a stepless start or termination of the strip in height may reduce steps or irregularities in subsequently applied layers .

[0029] In another embodiment the method comprises the steps of : winding the strip around the strip-winding drum according to a strip-winding pattern; and winding a first layer of the strip-winding pattern with a first winding density; and adj usting the die width and winding a second layer of strip-winding pattern with a second winding density di f ferent from the first winding density . In this way, di f ferent layers of the strip-winding pattern can be wound with di f ferent accuracies , depending on the requirements of the di f ferent layers , thereby increasing the ef ficiency where necessary and / or increasing the accuracy where necessary .

[0030] In another embodiment the extruder device comprises an extruder head that defines a flow channel for feeding elastomeric material through the die opening, wherein the die comprises a roller body that is rotatable about a roller axis parallel to the die plane , wherein the method comprises the step of : rotating the roller body about the roller axis during the extrusion of the strip to pull along the elastomeric material from the flow channel through the die opening . A further disadvantage of the known molding device of JP 4904049 B2 is that the extruder head is provided with a mouthpiece that has a relatively small and static cross section which requires high pressure from the rubber extruder to achieve the high throughputs required for efficient stripwinding . The high pressure causes increased friction at the mouthpiece, which heats up the rubber strip to temperatures approaching the vulcani zation temperature . Also , the relatively hot rubber strip remains relatively tacky and hot, potentially causing it to stick to any guiding elements between the extruder head and the drum, such as the calender rolls . Any remaining heat is ultimately transferred to the circumferential surface of the drum, which may slowly warm up during prolonged operation, thereby changing the operational conditions for any subsequent windings of the rubber strip . By providing the extruder device with a roller body at the die, the elastomeric material can be pulled along, thereby at least partially alleviating the pressure in the flow channel and / or significantly reducing the friction between the elastomeric material and the die . Hence , the extruder device can reach relatively high throughputs while keeping the pressure in the flow channel low, and thus preventing excessively high friction and / or temperature buildup in the elastomeric material .

[0031] Preferably, the method further comprises the step of : buf fering elastomeric material from the flow channel in a buf fer channel upstream of the die opening . By buf fering elastomeric material from the flow channel in the buf fer channel , small pressure variations in the flow channel as a result of di f ferences in inflow and outflow of the elastomeric material can be at least partially absorbed, thereby further reducing friction and / or temperature buildup in the elastomeric material , in particular when the die opening is relatively small .

[0032] In another embodiment the method further comprises the step of : generating a heat gradient in the strip during shaping of the strip at the die . The heat gradient in the strip can be used to influence the behavior of the strip after it leaves the die . In particular, a side of the strip that is relatively hot tends to be more flexible and tacky and may more easily follow a traj ectory . In particular, heat may be generated in the strip at a side that is at an inside of a curved traj ectory to be followed by said strip . Moreover, heat gradients may be used to compensate for increased pressure or friction in the elastomeric material of the strip as a result of adj ustments in the die width or die height , for example to promote the flow of elastomeric material in high pressure areas or areas of the die opening that are relatively small .

[0033] According to a second aspect , the invention provides an extruder device for extruding a strip, wherein the extruder device comprises a first die member and a second die member which are arranged on opposite sides of a feeding plane to form a die that shapes the strip, wherein the first die member is configured for feeding the strip along in a feeding direction parallel to the feeding plane , wherein the second die member comprises an adj ustment body that is rotatable about an adj ustment axis that extends parallel to the feeding plane and perpendicular to the feeding direction, wherein the adj ustment body is provided with a circumferential surface concentric to the adj ustment axis and a first extrusion channel extending over an adj ustment arc length along and recessed from said circumferential surface , wherein the first extrusion channel , considered in a cross section in a die plane perpendicular to the feeding direction, defines a die opening having a varying cross- sectional area along the adj ustment arc length of the first extrusion channel .

[0034] The aforementioned extruder device can be used in the method according to the first aspect of the invention and therefore can have the same technical advantages , which will not be repeated hereafter . The discussion of any further technical advantages will focus on the features of the extruder device that were not explicitly mentioned in the embodiments of the method according to the first aspect of the invention .

[0035] In particular, it may be observed from the description of the extruder device according to the second aspect of the invention that the varying cross-sectional area of the first extrusion channel can be conveniently used to variably adj ust the die width and / or the die height of the die opening, simply by rotating the adj ustment body about the adj ustment axis . Hence , no moving parts , other than the adj ustment body, are required to adj ust the die opening . The complexity of the extruder device may therefore be reduced .

[0036] In one embodiment the cross-sectional area of the first extrusion channel varies along the adj ustment arc length of the first extrusion channel in a width direction parallel to the adj ustment axis . This has the same technical advantages previously discussed in relation to the die width adj ustment of the method according to the first aspect of the invention .

[0037] In another embodiment the cross-sectional area of the first extrusion channel varies along the adj ustment arc length of the first extrusion channel in a height direction perpendicular to the feeding plane . This has the same technical advantages previously di scussed in relation to the die height adj ustment of the method according to the first aspect of the invention .

[0038] In another embodiment the cross-sectional area of the first extrusion channel varies steplessly, linearly or non-linearly along the adj ustment arc length of the first extrusion channel . Consequently, the amount of possible variations in the adj ustment of the die opening within the range of the first extrusion channel is large and / or the flexibility of the adj ustments can be increased .

[0039] In another embodiment the extruder device comprises an adj ustment drive that is operationally connected to the adj ustment body for rotating the adj ustment body about the adj ustment axis into and for holding the adj ustment body in di f ferent angular positions about said adj ustment axis . The adj ustment drive can ef fectively move and hold the adj ustment body in any angular position about the adj ustment axis , for extrusion of the strip in accordance with the cross-sectional area of the first extrusion channel that is in the die plane at that moment .

[0040] In another embodiment the adj ustment arc length is less than three-hundred-and-sixty degrees , preferably less than one-hundred-and-eighty degrees and most preferably less than one-hundred degrees . In other words , the first extrusion channel extends over less than a full revolution about the adj ustment axis . The first extrusion channel thus has a defined start and end within less than a full revolution . The adj ustment body can thus be rotated over the full adj ustment arc length within less than a single revolution .

[0041] In another embodiment the adj ustment body is at least partially circular, cylindrical or roller shaped . The circular, cylindrical or roller shaped adj ustment body can rotate through the die plane while keeping a constant radius to the adj ustment axis , thereby allowing for establ ishing a seal around the die opening in said die plane relative to a counter surface of the extruder device .

[0042] In another embodiment the adj ustment body is provided with a second and / or further extrusion channels distributed circumferentially or in a lateral direction parallel to the adj ustment axis over the circumferential surface . The second and / or further extrusion channels may have di f ferent width ranges , height ranges or shapes compared to the first extrusion channel . The second and / or further extrusion channels can be selectively aligned with the flow channel of the extruder device in the die plane to shape the strip according to the selected extrusion channel . When the second and / or further extrusion channels are distributed circumferentially relative to the first extrusion channel , the adj ustment body may simply be rotated to align the selected extrusion channel with the flow channel . When the second and / or further extrusion channels are distributed laterally, the adj ustment body may alternatively be shi fted laterally to align the selected extrusion channel with the flow channel .

[0043] In another embodiment the extruder device comprises a gap adj ustment mechanism for adj usting a gap between the first die member and the circumferential surface of the second die member in the die plane . In particular, the gap may be chosen to be suf ficiently small so as to prevent ingress of elastomeric material between the die members outside of the first extrusion channel , while allowing for suf ficient clearance to prevent direct physical contact between the die members , and associated wear .

[0044] Preferably, the gap adj ustment mechanism allows for adj usting the gap to equal to or less than thirty micrometers , preferably equal to or less than twenty micrometers and most preferably equal to or less than ten micrometers . The applicant has found that , at such a small gap, the ingress of elastomeric material can be prevented to such an extent that any residual elastomeric material that escapes the extruder device from said gap is limited to a very thin film that does not negatively af fect the ultimately quality of the tire component . At these or even smaller gap si zes , ingress of elastomeric material may be prevented altogether .

[0045] In another embodiment the extruder device comprises an extruder head that defines a flow channel for feeding elastomeric material in the feeding direction into the die .

[0046] Preferably, the first die member comprises a roller body that is rotatable about a roller axi s parallel to the die plane for pulling along the elastomeric material from the flow channel through the die opening . The advantages of the roller body have been previously discussed in relation to the first aspect of the invention .

[0047] More preferably, the extruder device comprises a roller drive that is operationally connected to the roller body for rotating the roller body about the roller axis . The roller body can be rotated continuously at a constant or a variable speed . In contrast to the previously discussed adj ustment drive , the roller drive is not conf igured to holding the roller body in a speci fic angular position .

[0048] In a further embodiment , that can also be applied independently of the features related to the first extrusion channel , the adj ustment body and the roller body together define a nip area, wherein the extruder device further comprise two sealing members that are configured to extend into the nip area on opposite sides of the flow channel in a lateral direction parallel to the adj ustment axis at the nip area to seal the flow channel relative to the adj ustment body and the roller body in said nip area . The sealing members can therefore prevent that elastomeric material leaves the flow channel in a lateral direction through the nip area .

[0049] Preferably, each sealing member of the two sealing members comprises a frictional running-in body, wherein the extruder device comprises a run- in mechanism for pressing the frictional running-in bodies o f the two sealing members into the nip area into running- in contact with both the adj ustment body and the roller body . The frictional running- in bodies are intentionally pressed into frictional contact with the adj ustment body and the roller body to wear over time , until the frictional running-in bodies are broken-in, worn-in or run-in into conformity with the shape of the adj ustment body and the roller body, thereby improving the sealing between the sealing members , the adj ustment body and the roller body at the nip area .

[0050] In another embodiment the extruder device comprises a buf fer channel upstream of the die opening for buf fering elastomeric material from the flow channel . The advantages of the buf fer channel have been previously discussed in relation to the first aspect of the invention .

[0051] In another embodiment the adj ustment body and the roller body together define a nip point and a final flow area extending from the flow channel up to said nip point , wherein the adj ustment body defines the final f low area along a shaping arc length about the adj ustment axis and wherein the roller body defines the final flow area along a pulling arc length about the roller axis that is greater than the shaping arc length with a factor of at least two , preferably at least three , and most preferably at least four . The elastomeric material is in contact with the roller body along the pulling arc length for a signi ficantly longer period of time or over a signi ficantly longer length, compared to the shaping arc . As a result , the elastomeric material is more likely to adhere more strongly to the first die member when leaving the extruder device . In this way, it can be ensured that the strip success fully separates from the second die member and follows the first die member along a traj ectory towards the strip-winding drum .

[0052] In another embodiment the extruder device comprises at least one heating element in or at the extruder head for heating for generating heat or a heat gradient in the elastomeric material in the flow channel . Additionally or alternatively, the extruder device comprises at least one heating element for heating the first die member and / or the second die member . The advantages of generating heat in the elastomeric material have been previously discussed in relation to the first aspect of the invention . When providing at least one heating element in the first die member, the strip is more likely to follow and / or adhere to the first die member when leaving the extruder device . In this way, it can be ensured that the strip success fully separates from the second die member and follows the first die member along a traj ectory towards the strip-winding drum .

[0053] According to a third aspect , the invention provides a tire building machine comprising an extruder device according to any one of the embodiments of the second aspect of the invention and a strip-winding drum, wherein the tire building machine comprises a control unit that is operationally connected to the extruder device and the strip-winding drum to control winding of the strip on the strip-winding drum according to a strip-winding pattern, wherein the extruder device comprises an adj ustment drive that is operationally connected to the adj ustment body for rotating the adj ustment body about the adj ustment axis , wherein the control unit is operationally connected to the adj ustment drive to adj ust the cross-sectional area of the die opening during the extrusion of the strip according to the strip-winding pattern . The tire building machine according to the third aspect of the invention includes the extruder device according to the second aspect of the invention and thus has the same technical advantages , which will not be repeated hereafter .

[0054] Preferably, the control unit stores instructions that , when carried out by a processor, cause the tire building machine to carry out the steps of the method according to any one of the embodiments of the first aspect of the invention .

[0055] 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 subj ect of divisional patent applications .

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The invention will be elucidated on the basis of an embodiment shown in the attached schematic drawings , in which : figure 1 shows a side view cross-section of an extruder device according to a first embodiment of the invention, having an adj ustment body; figures 2A-2D show front view cross-sections of the extruder device according to the line I I- I I in figure 1 , with the adj ustment body rotated with di fferent angular positions into each cross-section, corresponding to the angular positions K1-K4 in figure 1 ; figure 3 shows a side view cross-section of an alternative extruder device according to a second embodiment of the invention, having an adj ustment body; figures 4A-4D show front view cross-sections of the alternative extruder device according to the line IV-IV in figure 3 , with the adj ustment body rotated with dif ferent angular positions into each cross-section, corresponding to the angular positions K1-K4 in figure 3 ; figure 5 shows a side view cross-section of a further alternative extruder device according to a third embodiment of the invention, having an adj ustment body; figures 6A- 6D show front view cross-sections of the further alternative extruder device according to the line VIVI in figure 5, with the adj ustment body rotated with di fferent angular positions into each cross-section, corresponding to the angular positions K1-K4 in figure 5 ; figures 7A, 7B and 7C show, in graphs , the relationship between angular position and a width and / or height increase of a die opening of the extruder devices in figures 1 , 3 and 5 ; figure 8A shows a side view cross-section of a further alternative extruder device according to a fourth embodiment of the invention; figure 8B shows a front view cross-section of a further alternative extruder device according to a fifth embodiment of the invention; figure 9 shows a side view of the extruder device according to figure 1 ; figure 10A shows a front view of a tire component obtained by winding a strip on a strip-winding drum using a conventional extruder device ; figure 10B shows a front view of tire component obtained by winding a strip on the strip-winding drum of figure 10A using the extruder device according to figure 1 ; figures 11A-11C show front views of a tire building machine comprising the extruder device of figure 1 and a strip-winding drum, during the steps of a method for winding a strip around the strip-winding drum; and figure 12A-12C show front views of the tire building machine of figures 11A-11C, during the steps of an alternative method for winding a strip around the stripwinding drum . DETAILED DESCRIPTION OF THE INVENTION

[0058] Figure 1 shows an extruder device 3 according to a first embodiment of the invention for extruding a strip for use in tire manufacturing or tire building . In this particular example , the extruder device 3 is used to supply a strip for use in strip-winding . In strip-winding, the strip is wound in an at least partially overlapping manner, preferably in spirally or helically extending windings , to build-up a tire component . Alternatively, the extruder device 3 may be used to supply an apex, an apex filler, a gum strip or another strip-shaped tire component that is supplied through extrusion . The tire component formed by the strip is intended to be incorporated with other tire components in a green or unvulcani zed tire .

[0059] As shown in figure 1 , the extruder device 3 comprises an extruder head 4 that defines a flow channel 40 and a die 5 that defines a die opening 50 for shaping the strip . In this example , the die opening 50 is rectangular or substantially rectangular . It will be appreciated that the die opening 50 may have a di fferent cross-sectional shape , depending on the required shape of the strip to be formed .

[0060] The strip is an extrudate that is formed by extruding extrusion material , in particular elastomeric material , such as rubber, from the flow channel 40 through the die 5. To clearly show the features of the extruder device 3 , the extrudate and the extrusion material are not shown in figure 1 .

[0061] The extruder head 4 may be formed by a single extruder body or multiple extruder body sections , in particular to extruder halves 41 , 42 .

[0062] Figure 10B shows a drum 2 , in particular a stripwinding drum, for receiving the strip S . The drum 2 has a circumferential surface 20 that is rotatable about and / or concentric to a drum axis X .

[0063] The extruder device 1 of figure 1 and the drum 2 of figure 10B together may form a tire building machine 1 , as shown in figures 11A- 11C and 12A- 12C . In this example, the tire building machine 1 further comprises a control unit 10 that is functionally, electronically and / or operationally connected to the extruder device 3 and the strip-winding drum 2 . The control unit 10 is arranged, programmed or configured to control winding of the strip S on the strip-winding drum 2 according to a strip-winding pattern . In particular, the control unit 10 may be provided with a computer-readable medium or memory, more in particular, a non-transitory or tangible medium, e . g . a physical data carrier such as a harddrive, a USB-drive , a RAM memory or the like , that stores instructions that, when carried out by a processor, cause the tire building machine 1 to carry out the steps of a method that will be described later in further detail .

[0064] Returning to figure 1 , it can be seen that the extruder device 3 comprises a first die member 6 and a second die member 7 that together form the die 5 . The die members 6, 7 are located or arranged on opposite sides of a feeding plane P . In this example , the first die member 6 is located below the feeding plane P and the second die member 7 is located above the feeding plane P . It will however be appreciated that the positions may be reversed .

[0065] The first die member 6 is arranged or configured for urging, pulling or feeding the strip S along in a feeding direction F parallel to the feeding plane P . In this example , the first die member 6 comprises a roller body 60 that is rotatable about a roller axis R parallel to the feeding plane P . By rotating the roller body 60 , the elastomeric material from the flow channel 40 can effectively be pulled through the die 5 .

[0066] The roller body 60 defines a counter surface 65 concentric to the roller axis R that cooperates with the adj ustment body 6 to form the die 5 , in a manner that will be described in more detail hereafter . In this example , the counter surface 65 is cylindrical or straight cylindrical . Optionally, the counter surface 65 may be crowned or convex, e . g . have a slight curvature or increase in radius towards the middle of the roller body 60 .

[0067] As further shown in figure 1 , the extruder device 3 comprises a roller drive Ml that is functionally, mechanically and / or operationally coupled or connected to the roller body 60 for rotating the roller body 60 about the roller axis R . The roller drive Ml may for example be a rotational motor or servo . The roller drive Ml is configured for continuously rotating the roller body 60 in the same rotational direction during extrusion .

[0068] The second die member 7 comprises an adj ustment body 70 that is pivotable or rotatable about an adj ustment axis A that extends parallel to the feeding plane P and perpendicular to the feeding direction F . The adj ustment body 70 is provided with a circumferential surface 75 concentric to or extending concentrically about the adj ustment axis A. In this example , the circumferential surface 75 is cylindrical or straight cylindrical . In case of the aforementioned optional convex counter surface of the roller body 60 , the circumferential surface 75 of the adj ustment body 70 may be correspondingly concave .

[0069] Moreover, in this embodiment , the adj ustment body 70 is roller-shaped . Alternatively, the adj ustment body 70 may be partially circular, for example in the shape of a circle section or circle segment .

[0070] The circumferential surface 75 and the counter surface 65 are configured to be positioned as close as possible to the feeding plane P to form a nip point N between the two die members 6 , 7 . The nip point N lies in a die plane D extending parallel to and between the roller axis R and the adj ustment axis A. The circumferential surface 75 of the adj ustment body 70 and the counter surface 65 of the roller body 60 together define a final flow zone or final flow area VI where the elastomeric material transitions from the flow channel 40 towards the nip point N . More in particular, a nip zone or nip area V2 may be defined between the respective surfaces 65 , 75 as a subzone of the final flow area VI , where the elastomeric material no longer slides or slips relative to the die members 6, 7, but is pulled along as a result of the friction between the respective surfaces 65, 75.

[0071] In this example, the extruder device 3 is provided with a gap adjustment mechanism 30 for adjusting a gap between the first die member 6 and the circumferential surface 75 of the second die member 7 perpendicular to the feeding plane P and / or in or parallel to the die plane D. This gap is not considered part of the die opening 50. The gap adjustment mechanism 30 allows for adjusting the gap with a tolerance of less than ten micrometers, preferably five micrometers to a gap size of less than thirty micrometers. As such small gap sizes, the gap may prevent ingress of elastomeric material between the die members 6, 7 outside of the first extrusion channel 71, while allowing for sufficient clearance to prevent direct physical contact between the die members 6, 7, and associated wear. Any elastomeric material that still manages to escape from the first extrusion channel 71 into the gap between the die members 6, 7 only forms a very thin film that does not negatively affect the ultimately quality of the tire component.

[0072] As shown in dashed lines in figure 1 and in solid lines in figure 9, in this example, the gap adjustment mechanism 30 comprises a first holder 31 and a second holder 32 for holding the first die member 6 and the second die member 7, respectively, relative to each other in a manner such that the die members 6, 7 can move towards and away from each other with at least a vector component in the die plane D. In this example, the holders 31, 32 are pivotable about respective hinge axes parallel to and spaced apart from the roller axis R and the adjustment axis A. The gap adjustment mechanism 30 further comprises a gap adjustment wedge 33 that can be driven between and withdrawn the holders 31, 32 to adjust the spacing between the holders 31, 32, and thus adjust the gap between the die members 6, 7. The gap adjustment wedge 33 may be driven between or withdrawn manually, semi-automatically or automatically from the holders 31, 32, for example using a linear adjustment means, a screw, a bolt , a spindle , a slotted hole and fastener, or a linear actuator .

[0073] As shown in figure 1 , the adj ustment body 70 is further provided with a first extrusion slot or first extrusion channel 71 that extends over an adj ustment arc length LI along the circumferential surface 75. The first extrusion channel 71 is cut-out into the adj ustment body 70 and / or is recessed or lies back from the circumferential surface 75 . In this example, the adj ustment arc length LI is approximately one-hundred-and-f if ty degrees . It will be appreciated that the adj ustment arc length LI may be chosen di fferently, depending on the range and / or accuracy requirements of the variation .

[0074] The first extrusion channel 71 defines the shape of the die opening 50 . The die opening 50 has a varying cross- sectional area C along the adj ustment arc length LI of the first extrusion channel 71 . In particular, the first extrusion channel 71 has a cross-sectional area C, considered in a cross section in a die plane D perpendicular to the feeding direction F, that, depending on the angular position of the adj ustment body 70 about the adj ustment axis A, varies . In other words , by rotating the adj ustment body 70 , a di fferent part of the first extrusion channel 71 can be aligned with, intersects or coincides with the die plane D, to present a different cross-sectional area C at said die plane D, as shown by way of example in the cross sections of figures 2A-2D, corresponding to the angular positions K1-K4 in figure 1 .

[0075] As shown in figure 1 , the extruder device 3 comprises an adj ustment drive M2 that is functionally, mechanically and / or operationally coupled or connected to the adj ustment body 70 for rotating the adj ustment body 70 about the adj ustment axis A into the dif ferent angular positions K1-K4 about said adj ustment axis A. In particular, the adj ustment drive M2 is a positioning drive for accurately positioning and holding the adj ustment body 70 stationary in the dif ferent angular positions K1-K4 . As shown in figures 2A-2D, the cross-sectional area C of the first extrusion channel 71 varies along the adj ustment arc length LI of the first extrusion channel 71 between a minimum cross-sectional value Cmin in figure 2A and a maximum cross-sectional value Cmax in figure 2D . In this example , the cross-sectional area C is varied only in a width direction Y that is parallel to the adj ustment axis A, the roller axis R in figure 1 and / or the drum axis X in figure 10B .

[0076] In particular, as best seen in figures 2B-2D, the first extrusion channel 71 has two lateral sides 51 , 52 that define a die width W in said width direction Y . The die width W is varied between a minimum width value Wmin in figure 2A and a maximum width value Wmax in figure 2D . Note that, in this example, the minimum width value Wmin is zero . Consequently, the minimum cross-sectional value Cmin is also zero . In other words , at angular position KI the first extrusion channel 71 and / or die opening 50 is closed .

[0077] In this example, the cross-sectional area C and / or the die width W are varied symmetrically relative to the center of the die opening 50 . Alternatively, the cross- sectional area C and / or the die width W may be varied asymmetrically .

[0078] In one embodiment, as shown in figure 7A, the die width W is increased linearly or in a linear relationship to the angular position K .

[0079] Alternatively, as shown in figure 7B, the die width W may be increased non-linearly or only partially linearly . In this particular example, the die width W is increased from a minimum width value Wmin to an intermediate width value Wint at a first rate, and subsequently from the intermediate width value Wint to a maximum width value Wmax at a second rate different from the first rate . In this way, the strip width can be increased initially at a higher rate to rapidly build up to a strip width at which the strip is relatively strong or stable and does not tear easily .

[0080] Figure 7C shows an alternative embodiment in which the die width W starts at a non- zero minimum die width value Wmin .

[0081] In the embodiment as shown in figures 1 and 2A- 2D, the die height of the die opening 50 remains constant . It will however be appreciated that the die height H may be varied in the same manner, as will be illustrated by alternative embodiments which are discussed later .

[0082] As shown in figure 1 , the extruder head 4 is provided with an end surface 43 that leaves a release channel , an accumulation channel , an accumulation chamber, an accumulation volume, a buffer chamber, a buf fer volume or a buffer channel 45 between the first die member 6 and the extruder head 4 , upstream of the die opening 50 . The buffer channel 45 is branched off and / or outside of the flow channel 40 . In this example the buf fer channel 45 is in open communication with the environment external to the extruder device 3 . Hence, air can escape from the buf fer channel 45 as elastomeric material enters said buffer channel 45. In this manner, the buf fer channel 45 allows for temporarily buffering elastomeric material from the flow channel 40 to compensate for and / or at least partially absorb small pressure variations or fluctuations in the flow channel 40 as a result of dif ferences between the inflow and outflow of elastomeric material , for example as a result of gear pump speed variations .

[0083] In principal , the pressure in the flow channel 40 is suf ficiently low and the outflow of elastomeric material through the die opening 50 is sufficiently high to prevent elastomeric material accumulating excessively in the buffer channel 45 and / or escaping through the buffer channel 45 to the environment . In particular, the location of the buf fer channel 45 at the first die member 6 is convenient as the rotation of the first die member 6 automatically pulls the buffered elastomeric material from the buffer channel 45 back into the flow channel 40 as the pressure in the flow channel 40 decreases . A sensor (not shown) may be provided at , in or near the buffer channel 45 to measure the presence , absence , volume and / or progression of elastomeric material in the buffer channel 45.

[0084] It noted that pressure variations may also be suppressed by more accurately controlling the speed of the first die member 6 and / or the gear pump, in which case the buffer channel 45 may not be necessary .

[0085] The extruder head 4 further defines a receiving surface 44 for receiving the adj ustment body 70 of the second die member 7 in a manner such that the adj ustment body 70 can be rotated about the adj ustment axis A relative to the extruder head 4 while maintaining a constant seal or a constant gap between the adj ustment body 70 and the extruder head 4 . In this example, the receiving surface 44 is concave and / or concentric to the circumferential surface 75 of the adj ustment body 70 .

[0086] It will be appreciated that when the adj ustment body 50 is rotated, a varying unused length of the first extrusion channel 71 while be moved upstream of the die plane D out of final flow area VI and / or the nip area V2 . Any residual elastomeric material remaining in said unused length will probably not be taken along with the main flow of elastomeric material . The Applicant has however found the cycle time of forming a tire component T is usually short enough such that, when the unused length of the first extrusion channel 71 is rotated back into the final flow area VI and / or the nip area V2 , the residual elastomeric material will be mixed again and taken along with the main flow of the elastomeric material . Moreover, heat may be generated in the residual elastomeric material to keep the material properties constant .

[0087] As shown in figure 1 , the adj ustment body 70 defines the final flow area VI along a shaping arc length L3 about the adj ustment axis A from the point or location where the receiving surface 44 stops up to the nip point N . The roller body 60 defines the final flow area VI along a pulling arc length L2 about the roller axis R from the point or location where the end surface 43 stops up to the nip point N . Note that the pulling arc length L2 is greater than the shaping arc length L3 with a factor of at least two, thereby allowing the elastomeric material to adhere for a longer period of time and / or more strongly to the first die member 6 compared to the adherence to the second die member 6 .

[0088] As shown in dashed lines in figures 1 and 2A-2D, and in solid lines in figure 9 , the extruder device 3 further comprise two sealing members 81 , 82 that are configured to extend into the nip area V2 on opposite sides of the flow channel 40 in a lateral direction parallel to the adj ustment axis A and / or the width direction Y at the nip area V2 to seal the flow channel 40 relative to the adj ustment body 70 and the roller body 60 in said nip area V2 . The two sealing members 81 , 82 have a contour, as shown in figure 9, that is essentially a negative of the final flow area VI and / or the nip area V2 .

[0089] More speci fically, each sealing member of the two sealing members 81 , 82 comprises a frictional running-in body 80 . The frictional running-in body 80 is made from a relatively soft material , compared to the material of the die members 6, 7 , to allow for the frictional running-in body 80 to be intentionally run-in, worn-in or pre-worn against the die members 6 , 7 until its contact surface conforms in shape to the die members 6, 7 . In particular, the extruder device 3 comprises a run-in mechanism 85 for pressing the frictional running-in bodies 80 of the two sealing members 81 , 82 into the nip area V2 into frictional contact , running contact or running-in contact with both the adj ustment body 70 and the roller body 60 . In this example , the run-in mechanism 85 comprises a pressing wedge 86 that can be driven towards and withdrawn from the sealing members 81 , 82 in the feeding direction F move , bias or keep the sealing members 81 , 82 pressed against the die members 6 , 7 at the nip area V2 . The pressing wedge 86 may be driven or withdrawn manually, semi- automatically or automatically, for example using a linear adj ustment means , a screw, a bolt , a spindle , a slotted hole and fastener, or a linear actuator . As shown in figure 1 , the extruder device 3 optionally comprises at least one heating element 91 , 92 in or at the extruder head 4 for heating for generating heat or a heat gradient in the elastomeric material in the flow channel 40 . The extruder device 3 may, alternatively or additionally, optionally comprise at least one heating element 93 , 94 for heating the first die member 6 and / or the second die member 7 .

[0090] Figures 3 and 4A-4D show an alternative extruder device 103 according to a second embodiment of the invention, that dif fers from the first embodiment in that the die 105 comprises a second die member 107 with an alternative first extrusion channel 171 , defining an alternative die opening 150 that varies not only in the width direction Y, but also in a height direction Z perpendicular to the feeding plane P and / or parallel to the die plane D . Note that figures 7A-7C may alternatively be considered to show the relationship between the height H and the angular position K .

[0091] In an alternative embodiment (not shown) , only the height H may be varied .

[0092] Figures 5 and 6A- 6D show a further alternative extruder device 203 according to a third embodiment of the invention, that dif fers from the first embodiment and the second embodiment in that the die 205 comprises a second die member 207 with a further alternative first extrusion channel 271 , defining yet another alternative die opening 250 that has a dif ferent cross-sectional shape to the previously discussed die openings 50 , 150 . In particular, as best seen in figures 6B- 6D, the alternative die opening 250 has a triangular shape , suitable for example to extrude apexes or apex filler strips . Notable, the cross-sectional shape is varied in both width direction Y and height direction Z . In this example, the ratio between the width W and the height H remains the same, resulting in a scaling of the cross- sectional shape along the length of the alternative first extrusion channel 271 .

[0093] Figure 8A shows a further alternative extruder device 303 according to a fourth embodiment of the invention, that differs from the aforementioned embodiments in that it is provided with a second die member 307 that has an adj ustment body 370 in which two extrusion channels 371 , 372 are formed . The two extrusion channels 371 , 372 are distributed or spaced apart circumferentially about the adj ustment axis A. Each extrusion channel 371 , 372 has di fferent characteristics along its length, allowing for increased flexibility when choosing the shape , width or height of the die opening . To select the second extrusion channel 372 , the second die member 307 can be rotated further about the adj ustment axis A until the second extrusion channel 372 intersects with or is aligned with the die plane .

[0094] Figure 8B shows a further alternative extruder device 403 according to a fifth embodiment of the invention, that differs from the aforementioned embodiments in that it is provided with a second die member 407 that has an adj ustment body 470 in which two extrusion channels 471 , 472 are formed . In contrast to the previous embodiment, the two extrusion channels 471 , 472 are shifted or offset in a lateral direction parallel to the width direction Y . Hence, to switch between the extrusion channels 471 , 472 , the second die member 407 is shifted, displaced or moved relative to the first die member 6 in the width direction Y to align a dif ferent extrusion channel 471 , 472 with the flow channel .

[0095] A method for winding a strip S in a plurality of windings S l-Sn around a strip-winding drum 2 to form a tire component T, using any one of the aforementioned extruder devices 3 , 103 , 203 , 303 , 403 , will now be elucidated with reference to figures 10A, 10B, 11A-11C and 12A-12C .

[0096] Note that in figures 10A and 10B the reference numerals W, Wmin, Wint and Wmax are interchangeably used for indicating the strip width and the die width . In practice, there may be a slight increase in strip width compared to the die width as a result of die swell .

[0097] Figure 10A shows a strip S that is wound in a plurality of windings Sl-Sn while the die width W is kept constant, resulting in a constant strip width . Ideally, the first winding S I and the last winding Sn extend as close as possible to the dashed lines to form a straight cylindrical edge on both sides of the tire component T . However, as will be appreciated from figure 10A, the constant die width W, and as a result the constant strip width, causes considerable excess material , known as 'dog-ears ' , to stick out from the tire component T . Alternatively, any excess material may be tugged in underneath subsequently applied layers , thereby causing a local thickness increase at the overlap with subsequently applied layers .

[0098] Figure 10B shows a strip S that is wound in a plurality of windings S l-Sn while varying the die width W, resulting in a variable strip width that can be adj usted during the extrusion and / or the winding of the strip S . The die width W can be varied using any one of the extruder devices 3 , 103 , 203 , 303 , 403 as previously discussed .

[0099] In particular, it can be observed in figure 10B that the die width W is gradually or steplessly increased for a first section of the strip S corresponding to a leading tip of a first winding S I of the plurality of windings S l-Sn . The minimum width value Wmin may be zero or close to zero , as shown in figure 7A and 7B, allowing the first winding S I of the strip S to be started with a zero or a close-to-zero width W . Optionally, as shown in figure 7B, the width W may be increased rapidly from the minimum width value Wmin to an intermediate width value Wint at a first rate , wherein the width W is increased from the intermediate width value Wint to a maximum width value Wmax at a second rate different from the first rate .

[0100] It can be further seen in figure 10B that the die width W is reduced for a second section of the strip S corresponding to a trailing tip of a last winding Sn of the plurality of windings S l-Sn, allowing for said last winding Sn to be terminated with a zero width or a close-to-zero width . In particular, the die width W may be decreased to a minimum width value Wmin of less than one millimeter, preferably less than half a millimeter and most preferably zero millimeters .

[0101] Figure 10B further shows , by way of example, that the die width W is varied for one intermediate winding of the plurality of windings Sl-Sn .

[0102] It will be appreciated that additionally or alternatively, the height and / or shape of the strip S may be varied during the extrusion and / or the winding of the strip S in a similar manner, using any one of the aforementioned extruder devices 3 , 103 , 203 , 303 , 403 .

[0103] As shown in figures 11A-11C and 12A- 12C, during strip-winding, a relative movement E , E' is generated between the extruder device 3 and the strip-winding drum 2 in a direction parallel to the drum axis X to arrange the windings of the strip in a side-by-side or at least partially overlapping relationship, in particular in a helically or spirally extending winding pattern .

[0104] When the die width W is increased symmetrically, the strip width increases on both sides . However, as shown in figure 10B, it is preferably, at least for the first winding S I and the last winding Sn, to have at least one side of the strip S extending in parallel to a straight cylindrical edge of the tire component T . To achieve this while increasing the die width W symmetrically, two control schemes are envisioned, as shown in figures 11A- 11C and 12A-12C .

[0105] Figures 11A-11C show a first manner of controlling a relative movement E by moving the strip-winding drum 2 in the width direction Y relative to the extruder device 3 to at least partially compensate for a shi ft of one lateral side 51 of the two lateral sides 51 , 52 of the die opening 50 in said width direction Y during the adj ustment of the die width W . Figures 12A-12C show a second manner of controlling a relative movement E' by moving the extruder device 3 in the width direction Y relative to the strip-winding drum 2 to at least partially compensate for the same shi ft . In both control schemes , the relative movement E, E' between the stripwinding drum 2 and the extruder device 3 is preferably chosen to be equal to hal f of the adj ustment of the die width W .

[0106] The aforementioned steps of the method may be applied to a single layer of windings Sl-Sn, as shown in figure 10B, or to multiple layers (not shown) of windings of the same or di fferent strips . It will be appreciated that the die width W, the die height H and / or the overall shape of the die opening 50 may be adj usted during extrusion for each layer, per winding or even for individual windings , allowing for winding with di fferent winding densities and / or for optimal flexibility during strip-winding .

[0107] 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 .

[0108] LIST OF REFERENCE NUMERALS

[0109] 1 tire building machine

[0110] 10 control unit

[0111] 2 strip-winding drum

[0112] 20 winding surface

[0113] 3 extruder device

[0114] 30 gap adj ustment mechanism

[0115] 31 first holder

[0116] 32 second holder

[0117] 33 gap adj ustment wedge

[0118] 4 extruder head

[0119] 40 flow channel

[0120] 41 first extruder hal f

[0121] 42 second extruder half

[0122] 43 end surface

[0123] 44 receiving surface

[0124] 45 buffer channel

[0125] 5 die 50 die opening

[0126] 51 first lateral side

[0127] 52 second lateral side

[0128] 6 first die member

[0129] 60 roller body

[0130] 65 counter surface

[0131] 7 second die member

[0132] 70 adj ustment body

[0133] 71 first extrusion channel

[0134] 75 circumferential surface

[0135] 80 frictional running-in body

[0136] 81 first sealing member

[0137] 82 second sealing member

[0138] 85 run-in mechanism

[0139] 86 pressing wedge

[0140] 91-94 heating elements

[0141] 103 alternative extruder device

[0142] 105 die

[0143] 150 die opening

[0144] 107 second die member

[0145] 171 first extrusion channel

[0146] 203 further alternative extruder device

[0147] 207 second die member

[0148] 205 die

[0149] 250 die opening

[0150] 271 first extrusion channel

[0151] 303 further alternative extruder device

[0152] 307 second die member

[0153] 370 adj ustment body

[0154] 371 first extrusion channel

[0155] 372 second extrusion channel

[0156] 403 further alternative extruder device

[0157] 407 second die member

[0158] 470 adj ustment body

[0159] 471 first extrusion channel

[0160] 472 second extrusion channel

[0161] A adj ustment axis C cross-sectional area

[0162] Cmin minimum cross-sectional area value

[0163] Cmax maximum cross-sectional area value

[0164] D die plane

[0165] E relative movement

[0166] E' alternative relative movement

[0167] F feeding direction

[0168] H die height

[0169] Hmin minimum height value

[0170] Hmax maximum height value

[0171] K angular direction

[0172] K1-K4 angular positions

[0173] LI adj ustment arc length

[0174] L2 pulling arc length

[0175] L3 shaping arc length

[0176] Ml roller drive

[0177] M2 adj ustment drive

[0178] M3 drum drive

[0179] N nip point

[0180] P feeding plane

[0181] R roller axis

[0182] S strip

[0183] SI first winding

[0184] S2-S4 intermediate windings

[0185] Sn last winding

[0186] T tire component

[0187] VI final flow area

[0188] V2 nip area

[0189] W die width

[0190] Wmin minimum width value

[0191] Wint intermediate width value

[0192] Wmax maximum width value

[0193] Y width direction

[0194] Z height direction

Claims

C L A I M S1 . Method for winding a strip in a plurality of windings around a strip-winding drum to form a tire component , wherein the method comprises the steps of : extruding the strip in a feeding direction with the use of an extruder device, wherein the extruder device comprises a die that shapes the strip, wherein the die, considered in a cross section in a die plane perpendicular to the feeding direction, defines a die opening with a die width in a width direction parallel to the die plane , wherein the die width is adj ustable ; adj usting the die width of the die opening during extrusion of the strip; and winding the strip around the strip-winding drum .2 . Method according to claim 1 , wherein the die width is adj usted steplessly .3 . Method according to claim 1 or 2 , wherein the method further comprises the step of : increasing the die width for a first section of the strip corresponding to a leading tip of a first winding of the plurality of windings .4 . Method according to claim 3 , wherein the die width is increased starting from a minimum width value of less than one millimeter, preferably less than hal f a millimeter and most preferably zero millimeters .

5. Method according to claim 3 or 4 , wherein the die width is increased from a non- zero minimum width value to a maximum width value that is greater than the non-zero minimum width value by a factor of at least two, preferably at least five and most preferably at least ten .

6. Method according to claim 3 or 4 , wherein the die width is increased from a minimum width value to an intermediate width value at a first rate, wherein the die width is increased from the intermediate width value to a maximum width value at a second rate dif ferent from the firstrate .7 . Method according to claim 6, wherein the second rate is slower than the first rate .8 . Method according to any one of the preceding claims , wherein the die width is increased at least partially linearly .

9. Method according to any one of the preceding claims , wherein the method further comprises the step of : reducing the die width for a second section of the strip corresponding to a trailing tip of a last winding of the plurality of windings .10 . Method according to claim 9 , wherein the die width is decreased to a minimum width value of less than one millimeter, preferably less than half a millimeter and most preferably zero millimeters .11 . Method according to any one of the preceding claims , wherein the method further comprises the step of : varying the die width for one or more intermediate windings of the plurality of windings between a first winding and a last winding of the plurality of windings .12 . Method according to any one of the preceding claims , wherein the die width is adj usted symmetrically in the width direction .13 . Method according to any one of the preceding claims , wherein the die has two lateral sides that define the die width of the die opening in the width direction, wherein the method further comprises the step of : generating a relative movement between the strip-winding drum and the extruder device in the width direction in response to and / or simultaneously with the adj ustment of the die width to at least partially compensate for a shift of one lateral side of the two lateral sides in said width direction during the adj ustment of the die width .14 . Method according to claim 13 , wherein the relative movement between the strip-winding drum and the extruder device is equal to half of the adj ustment of the die width .15 . Method according to any one of the preceding claims , wherein the die opening has a die height in a height direction parallel to the die plane and perpendicular to the width direction, wherein the die height is adj ustable , wherein the method further comprises the step of : adj usting the die height of the die opening during the extrusion of the strip .16 . Method according to claim 15, wherein the die height is adj usted simultaneously with the adj ustment of the die width .17 . Method according to claim 15 or 16 , wherein the die height is adj usted steplessly .18 . Method according to any one of the preceding claims , wherein the die opening has a cross-sectional area that is adj ustable from a minimum cross-sectional area value up to a maximum cross-sectional area value , wherein the minimum cross-sectional area value is zero , wherein the method comprise the step of : adj usting the cross-sectional area of the die opening during the extrusion of the strip and using the minimum cross-sectional area value at least once during said adj ustment .19 . Method according to any one of the preceding claims , wherein the method comprises the steps of : winding the strip around the strip-winding drum according to a strip-winding pattern; and winding a first layer of the strip-winding pattern with a first winding density; and adj usting the die width and winding a second layer of strip-winding pattern with a second winding density di fferent from the first winding density .20 . Method according to any one of the preceding claims , wherein the extruder device comprises an extruder head that defines a flow channel for feeding elastomeric material through the die opening, wherein the die comprises a roller body that is rotatable about a roller axis parallel to the die plane, wherein the method comprises the step of :rotating the roller body about the roller axis during the extrusion of the strip to pull along the elastomeric material from the flow channel through the die opening .21 . Method according to claim 20 , wherein the method further comprises the step of : buf fering elastomeric material from the flow channel in a buf fer channel upstream of the die opening .22 . Method according to any one of the preceding claims , wherein the method further comprises the step of : generating a heat gradient in the strip during shaping of the strip at the die .23 . Extruder device for extruding a strip, wherein the extruder device comprises a first die member and a second die member which are arranged on opposite sides of a feeding plane to form a die that shapes the strip, wherein the first die member is configured for feeding the strip along in a feeding direction parallel to the feeding plane , wherein the second die member comprises an adj ustment body that is rotatable about an adj ustment axis that extends parallel to the feeding plane and perpendicular to the feeding direction, wherein the adj ustment body is provided with a circumferential surface concentric to the adj ustment axis and a first extrusion channel extending over an adj ustment arc length along and recessed from said circumferential surface, wherein the first extrusion channel , considered in a cross section in a die plane perpendicular to the feeding direction, defines a die opening having a varying cross-sectional area along the adj ustment arc length of the first extrusion channel .24 . Extruder device according to claim 23 , wherein the cross-sectional area of the first extrusion channel varies along the adj ustment arc length of the first extrusion channel in a width direction parallel to the adj ustment axis .25 . Extruder device according to claim 23 or 24 , wherein the cross-sectional area of the first extrusion channel varies along the adj ustment arc length of the firstextrusion channel in a height direction perpendicular to the feeding plane .26 . Extruder device according to any one of claims 23-25, wherein the cross-sectional area of the first extrusion channel varies steplessly, linearly or non-linearly along the adj ustment arc length of the first extrusion channel .27 . Extruder device according to any one of claims 23-26, wherein the extruder device comprises an adj ustment drive that is operationally connected to the adj ustment body for rotating the adj ustment body about the adj ustment axis into and for holding the adj ustment body in different angular positions about said adj ustment axis .28 . Extruder device according to any one of claims 23-27 , wherein the adj ustment arc length is less than three- hundred-and-sixty degrees , preferably less than one-hundred- and-eighty degrees and most preferably less than one-hundred degrees .29 . Extruder device according to any one of claims 23-28 , wherein the adj ustment body is at least partially circular .30 . Extruder device according to any one of claims 23-29, wherein the adj ustment body is cylindrical or roller shaped .31 . Extruder device according to any one of claims 23-30 , wherein the adj ustment body is provided with a second and / or further extrusion channels distributed circumferentially or in a lateral direction parallel to the adj ustment axis over the circumferential surface .32 . Extruder device according to any one of claims 23-31 , wherein the extruder device comprises a gap adj ustment mechanism for adj usting a gap between the first die member and the circumferential surface of the second die member in the die plane .33 . Extruder device according to claim 32 , wherein the gap adj ustment mechanism allows for adj usting the gap to equal to or less than thirty micrometers , preferably equalto or less than twenty micrometers and most preferably equal to or less than ten micrometers .34 . Extruder device according to any one of claims 23-33 , wherein the extruder device comprises an extruder head that defines a flow channel for feeding elastomeric material in the feeding direction into the die .35 . Extruder device according to claim 34 , wherein the first die member comprises a roller body that is rotatable about a roller axis parallel to the die plane for pulling along the elastomeric material from the flow channel through the die opening .36 . Extruder device according to claim 35 , wherein the extruder device comprises a roller drive that is operationally connected to the roller body for rotating the roller body about the roller axis .37 . Extruder device according to claim 35 or 36 , wherein the adj ustment body and the roller body together define a nip area, wherein the extruder device further comprise two sealing members that are configured to extend into the nip area on opposite sides of the flow channel in a lateral direction parallel to the adj ustment axis at the nip area to seal the flow channel relative to the adj ustment body and the roller body in said nip area .38 . Extruder device according to claim 37 , wherein each sealing member of the two sealing members comprises a frictional running-in body, wherein the extruder device comprises a run-in mechanism for pressing the frictional running-in bodies of the two sealing members into the nip area into running-in contact with both the adj ustment body and the roller body .39 . Extruder device according to any one of claims 34-38 , wherein the extruder device comprises a buffer channel upstream of the die opening for buf fering elastomeric material from the flow channel .40 . Extruder device according to claim 35 or 36 , wherein the adj ustment body and the roller body together define a nip point and a final flow area extending from theflow channel up to said nip point, wherein the adj ustment body defines the final flow area along a shaping arc length about the adj ustment axis and wherein the roller body defines the final flow area along a pulling arc length about the roller axis that is greater than the shaping arc length with a factor of at least two, preferably at least three, and most preferably at least four .41 . Extruder device according to any one of claims 34-40 , wherein the extruder device comprises at least one heating element in or at the extruder head for generating heat or a heat gradient in the elastomeric material in the flow channel .42 . Extruder device according to any one of claims 23-41 , wherein the extruder device comprises at least one heating element for heating the first die member and / or the second die member .43 . Tire building machine comprising an extruder device according to any one of claims 23-42 and a stripwinding drum, wherein the tire building machine comprises a control unit that is operationally connected to the extruder device and the strip-winding drum to control winding of the strip on the strip-winding drum according to a strip-winding pattern, wherein the extruder device comprises an adj ustment drive that is operationally connected to the adj ustment body for rotating the adj ustment body about the adj ustment axis , wherein the control unit is operationally connected to the adj ustment drive to adj ust the cross-sectional area of the die opening during the extrusion of the strip according to the strip-winding pattern .44 . Tire building machine according to claim 43 , wherein the control unit stores instructions that , when carried out by a processor, cause the tire building machine to carry out the steps of the method according to any one of claims 1-22 .-o-o-o- o- o-o-o- o—RM / HZ