Coating unit, tire manufacturing apparatus and method for applying a continuous strip to a drum

Abstract

The present invention relates to an application unit, a tire manufacturing apparatus, and a method for applying a continuous strip to a drum. The application unit includes an application roll having a roller body that is rotatable about a roll axis and defines a holding surface extending in the circumferential direction about the roll axis. The application unit further includes a holding member for holding the continuous strip at a holding position on the holding surface. The holding member is arranged to follow the continuous strip at the holding position on the holding surface along a holding arc of at least 10 degrees about the roll axis when the roller body rotates about the roll axis.

Description

Background Art

[0001] Relates to a coating unit, a tire manufacturing apparatus, and a method of applying a continuous strip to a drum.

[0002] WO2022 / 177421A1 discloses a coating unit, a tire manufacturing apparatus, and a method of applying a continuous strip to a drum. The coating unit includes a coating roller having a roller body rotatable about a roll axis, and applies the continuous strip to the drum in a coating direction perpendicular to the roll axis. The coating roller is provided with holding elements in the form of suction ports distributed over the entire roller body, and holds the continuous strip on the roller body by suction.

Summary of the Invention

[0003] It has been found that the drawback of the coating roller disclosed in WO2022 / 177421A1 is that suction force alone is insufficient to reliably hold the continuous strip on the coating roller. In particular, the leading end of the continuous strip tends to continue linearly rather than being sucked into the coating roller by the suction ports of the holding surface. If the leading end is not reliably held, the position of the leading end on the coating roller becomes unclear, and as a result, the application of the leading end, and possibly the entire continuous strip, to the drum may be inaccurate or the application may fail altogether.

[0004] An object of the present invention is to provide a coating unit, a tire manufacturing apparatus, and a method of applying a continuous strip to a drum that can improve the coating accuracy of the strip on the drum.

[0005] According to a first aspect, the present invention provides an application unit for applying a continuous strip to a drum, the application unit comprising an application roll having a roller body rotatable about a roll axis and defining a holding surface extending circumferentially around the roll axis, the application unit further comprising a holding member for holding the continuous strip in a holding position on the holding surface, the holding member being arranged to follow the continuous strip in the holding position on the holding surface along at least a 10-degree holding arc around the roll axis when the roller body rotates around the roll axis.

[0006] By using the holding member to hold the continuous strip on the holding surface at the holding position from the outside, the application roll can hold the continuous strip more reliably by suction, especially at its leading end. When the roller body rotates, the holding member follows the continuous strip in the holding position on the holding surface, so that the continuous strip can be held more reliably on the application roller during at least a part of the rotation of the roller body. In particular, when the suction ports are not yet connected to the vacuum source initially, the holding member can hold the continuous strip on the holding surface until each suction port is rotated to the position where it is connected to the vacuum source. Thus, the continuous strip can be held by either the holding member, one or both of the suction ports, in accordance with the principle of never releasing the continuous strip. As a result, the continuous strip is received, arranged, and / or held in a predetermined position more accurately on the application roll. As a result, the continuous strip is pasted onto the drum more accurately.

[0007] The holding arc is preferably at least 20 degrees, preferably at least 30 degrees. The longer the holding arc, the longer the length by which the continuous strip can be reliably held on the application roller body.

[0008] In yet another embodiment, the application unit comprises a drive mechanism for moving the holding member along the holding arc, whereby the movement of the holding member can be controlled and / or automated.

[0009] Preferably, after moving the holding member along the holding arc, the drive mechanism is configured to move the holding member away from the holding surface, whereby the holding member can secure a space for subsequent interaction between the coating roll and the drum.

[0010] In a further embodiment, the drive mechanism includes a first drive unit and a second drive unit that move the holding member along the holding arc, and the holding member moves with a first vector component in a first driving direction and a second vector component in a second driving direction, respectively. By combining the two vector components, a complex movement of the holding member along a curvature that coincides with the holding arc can be generated.

[0011] Preferably, the first drive unit is arranged to move the holding member over a first stroke in the first driving direction, and the first stroke coincides with the roll axis and reaches the end point in front of an intermediate plane extending perpendicular to the first driving direction. Therefore, the movement of the holding member can be limited to a position along the upper half of the coating roll. This is the side surface of the coating roll where the continuous strip is first supplied from the extruder and is also the side surface of the coating roll where the continuous strip is transferred from the coating roll to the drum. Therefore, it is sufficient for the holding member to move along this part of the coating roll.

[0012] In yet another embodiment, the second drive unit is arranged to move the holding member only in a second driving direction away from the holding surface when the holding member reaches the end of the first stroke. Therefore, the holding member can be moved away from the coating roll to secure a space for subsequent interaction between the coating roll and the drum.

[0013] In a further embodiment, the first driving direction is perpendicular to the roll axis, in other words, the holding member is movable within a plane perpendicular to the roll axis.

[0014] In a further embodiment, the first driving direction is vertical or substantially vertical. Thus, the holding member can approach the coating roll at least with a vector component in the vertical direction.

[0015] In a further embodiment, the first driving unit and / or the second driving unit includes a linear driving unit, preferably a pneumatic cylinder. The linear driving unit, particularly the pneumatic cylinder, can control the holding member to move at least with a vector component in each driving direction when the holding member has freedom of movement with respect to the coating roll.

[0016] In a further embodiment, the holding member comprises fingers, pressing rolls, or a pressing conveyor that contact the continuous strip at the holding position while following the continuous strip along the holding arc. The fingers, pressing rolls, or the pressing conveyor can physically contact the continuous strip while following the continuous strip along the holding arc, which can be done by moving the entire finger or pressing roller along the holding arc, or by designing the infinite contact surface of the pressing conveyor to at least span the holding arc.

[0017] In a further embodiment, the holding member comprises a contact surface that contacts the continuous strip at the holding position on the holding surface, and the contact surface extends at an oblique contact angle with respect to the first driving direction. The oblique contact angle can be selected such that the holding member can contact the continuous strip properly and / or reliably at both the starting point and the ending point of the holding arc.

[0018] In another embodiment, the coating unit is further provided with a separating element for separating the continuous strip from the holding member. The separating element can prevent the continuous strip from remaining stuck to the holding member when the holding member moves away from the coating roll at the end of the holding arc.

[0019] Preferably, the separating element is a blow-off groove provided in the holding member. In this way, when the continuous strip is pulled in the second driving direction together with the holding member, it is effectively separated from the holding member and / or blown back onto the application roll.

[0020] In another embodiment, the application roll is further provided with a plurality of suction ports in the roller body so as to hold the continuous strip on the holding surface by suction. In another embodiment, the roller body is annular, and the application roller further includes an inner member disposed concentrically within the roller body. The roller body is rotatable circumferentially around the inner member, and the inner member includes a first chamber that communicates with a plurality of suction ports in a first circumferential cross-section of the roller body. The first chamber is connectable to a decompression source that holds the continuous strip on the holding surface in the first circumferential cross-section.

[0021] Preferably, the holding arc at least partially overlaps the first circumferential cross-section. In particular, the holding arc overlaps at least 80% of the first circumferential cross-section. Thus, the continuous strip can be held by the holding member along at least a part of the circumferential cross-section of the application roll that holds the continuous strip by suction.

[0022] In a further embodiment, the inner member includes a second chamber that communicates with a plurality of suction ports in a second circumferential cross-section of the roller body. The second chamber is connectable to a compressed air source for blowing the continuous strip off the holding surface in the second circumferential cross-section. In this way, the continuous strip can be blown off the holding surface and effectively transferred from the application roll to the drum.

[0023] Preferably, the holding arc is in front of or reaches the end point in the second circumferential cross-section. Thus, the holding member does not interfere with the blowing or unnecessarily press the continuous strip against the application roll at the position where the continuous strip should finally be separated from the application roll.

[0024] According to a second aspect, the present invention provides a tire manufacturing apparatus for applying a continuous strip to a drum, the tire manufacturing apparatus comprising an application unit according to any one of the embodiments of the first aspect of the present invention, the tire manufacturing apparatus further comprising an extruder for continuously extruding the continuous strip onto an application roll and a drum for continuously receiving the continuous strip from the application roll.

[0025] Since the tire manufacturing apparatus includes an application unit according to the first aspect of the present invention, the same technical advantages are achieved, which will not be repeated hereinafter.

[0026] According to a third aspect of the present invention, there is provided a method of applying a continuous strip to a drum using an application unit according to any one of the embodiments of the first aspect of the present invention, the method including the following steps. Rotating an application roll about a roll axis while holding the continuous strip on a holding surface by suction. Holding the continuous strip at a holding position on the holding surface by a holding member while causing the continuous strip to follow the holding position on the holding surface along a holding arc as a roller body rotates around the roll axis.

[0027] Since this method relates to the actual implementation of the application unit according to the first aspect of the present invention, the same technical advantages are achieved, which will not be repeated hereinafter.

[0028] In a preferred embodiment, the method further includes the following steps. Moving the holding member along the holding arc and then moving the holding member away from the holding surface.

[0029] In a further embodiment, the method further includes the following steps. Moving the holding member along the holding arc and then separating the continuous strip from the holding member.

[0030] In a further embodiment, the method further comprises the following steps. Continuously extruding a continuous strip onto an application roll, and Continuously applying the continuous strip from the application roll onto a drum.

[0031] In the context of the present invention, the term "continuous" is used to indicate a continuous process using a continuous strip, where the continuous strip is continuously extruded and applied without cutting the continuous strip to a predetermined length prior to each winding, and is wound around the drum several times. As a result, the length of the continuous strip exceeds the circumference of the drum and / or the application roll.

[0032] In a further embodiment, the continuous strip has a leading end, and the continuous strip is held at a holding position on a holding surface at the leading end. As described above, the leading end may tend to continue along a straight line rather than being held on the application roll by suction. Therefore, by using a holding member to hold the leading end, the accuracy in applying the leading end and the remaining portion of the continuous strip following the leading end onto the drum can be significantly improved.

[0033] According to a fourth, non-claimed aspect, the present invention provides an application unit for applying a continuous strip onto a drum, the application unit comprising an application roll having a roller body rotatable about a roll axis and defining a holding surface extending circumferentially around the roll axis, the application unit further comprising a holding member for holding the continuous strip at a holding position on the holding surface, the holding member being provided with an endless contact surface, in particular an endless belt, for contacting the continuous strip along at least a 10-degree holding arc around the roll axis when the roller body rotates around the roll axis.

[0034] The coating unit according to the fourth aspect of the present invention has substantially the same technical advantages as the aforementioned coating unit. Further, the coating unit according to the fourth aspect of the present invention may be combined with any feature or embodiment according to the previous aspects of the present invention with necessary modifications.

[0035] In one embodiment, the holding member is a hanger belt.

[0036] In a further embodiment, the infinite contact surface is actively driven at the same speed or substantially the same speed as the continuous strip. Alternatively, the infinite contact surface moves passively as a result of friction between the continuous strip and the infinite contact surface.

[0037] The various aspects and features described and shown herein can be applied individually as much as possible. These individual aspects, particularly those described in the appended dependent claims, can be the subject of a divisional patent application.

Brief Description of the Drawings

[0038] The present invention will be described based on exemplary embodiments shown in the accompanying schematic drawings.

[0039] Figures 1 to 6 are side views of a tire manufacturing apparatus according to a first embodiment of the present invention, showing steps of a method of applying a strip onto a drum using the tire manufacturing apparatus.

[0040] Figure 7 is a side view of an alternative tire manufacturing apparatus according to a second embodiment of the present invention, showing steps of a method of applying a strip onto a drum using the alternative tire manufacturing apparatus. Detailed Description of the Invention

[0041] Figure 1 shows a tire manufacturing apparatus 1 for applying a continuous strip 9 onto a drum 8 according to a first embodiment of the present invention. In this example, the continuous strip 9 is used to wind the strip around a drum 8 for a tire component (not shown). Thus, the drum 8 may be a strip winding drum. In strip winding, the continuous strip 9 is wound around the drum 8 a plurality of times to form a layer of the tire component, thereby gradually increasing the cross-section of the tire component. The continuous strip 9 comprises or consists of an elastomeric material, especially rubber.

[0042] In the present invention, the term "continuous strip" is used to refer to a strip of sufficient length to continuously apply and wind the continuous strip 9 around the drum 8 several times without cutting the continuous strip 9 to a predetermined length before each winding. Thus, the length of the continuous strip 9 exceeds the circumference of the drum 8.

[0043] The tire manufacturing apparatus 1 comprises an extruder 2 for continuously extruding the continuous strip 9 and an application unit 3 for continuously applying the continuous strip 9 to the drum 8. In this example, the drum 8 is also regarded as part of the tire manufacturing apparatus 1. The drum 8 continuously receives the continuous strip 9 from the application unit 3.

[0044] As further shown in FIG. 1, the application unit 3 comprises an application roller or roll 4. The application roll 4 comprises a roller body 40. The roller body 40 is rotatable about a roll axis X. In this example, the roller body 40 is annular or ring-shaped. The roller body 40 defines a holding surface 41 extending in the circumferential direction C about the roll axis X. The circumference of the holding surface 41 is considerably smaller than the circumference of the drum 8.

[0045] The application roll 4 is further provided with a plurality of suction openings or suction ports 42 in the roller body 40 to hold the continuous strip 9 on the holding surface 41 by suction.

[0046] The coating roll 4 further includes an inner member 43 concentrically arranged inside the roller body 40. The roller body 40 is rotatable in the circumferential direction C around the inner member 43. The inner member 43 remains stationary and / or is fixed around the roll axis X.

[0047] The inner member 43 includes a first chamber 44 that communicates with a group of a plurality of suction ports 42 in the first circumferential cross-section E1 of the roller body 40. The first chamber 44 can be connected to a vacuum source or a decompression source that holds the continuous strip 9 on the holding surface 41 in the first circumferential cross-section E1.

[0048] The inner member 43 further includes a second chamber 45 that communicates with a group of a plurality of suction ports 42 in the second circumferential cross-section E2 of the roller body 40. The second chamber 45 can be connected to a compressed air source for blowing off the continuous strip 9 from the holding surface 41 of the second circumferential portion E2.

[0049] The aforementioned coating roll 4 includes the roller body 40, the holding surface 41, the suction ports 42, the inner body 43, and the chambers 44 and 45, and is similar or identical to the coating roll and corresponding components disclosed in International Publication No. WO 2022 / 177421.

[0050] As shown in FIG. 2, the coating unit 3 further includes a pressing member or a holding member 5 for pressing and / or holding the continuous strip 9 at the holding position P on the holding surface 41. In this example, the holding member 5 is formed as a block or a finger for passively contacting the continuous strip 9. Alternatively, a pressing roller may be used.

[0051] As can be seen by comparing FIGS. 2 and 3, the holding member 5 is arranged to move, track, or follow a continuous strip 9 at a holding position P on the holding surface 41 along a holding arc A around the roll axis X. The holding arc A starts from the angular position where the holding member 5 first contacts the continuous strip 9 as shown in FIG. 2 and ends at the angular position around the roller axis X where the holding member 5 leaves, is released from, or is pulled away from the continuous strip 9 as shown in FIG. 4. In this example, the holding arc A extends along or around the roller axis X over 40 degrees or more.

[0052] In particular, the holding arc A at least partially overlaps, for example, at least 80% or more, with the first circumferential cross-section E1. Further, in this example, the holding arc A reaches its end point in front of or at the second circumferential portion E2, or at the second circumferential cross-section E2.

[0053] As best shown in FIG. 1, the holding member 5 includes a finger body or finger tip 50 having a contact surface 51 that contacts the continuous strip 9 at the holding position P on the holding surface 41. In this example, the contact surface 51 extends at an oblique contact angle H with respect to the vertical plane. In particular, the oblique contact angle H is selected such that the contact surface 51 can surely contact the continuous strip 9 at both the start point and the end point of the holding arc A while the orientation of the holding member 5 with respect to the application roll 4 remains the same or constant. In this example, the contact surface 51 extends at least 30 degrees, preferably at least 40 degrees, with respect to the vertical plane.

[0054] As shown in FIG. 4, the application unit 3 is further provided with a separating element 52 for separating the continuous strip 9 from the holding member 5. In this example, the separating element 52 is a blow-off groove provided in the holding member 5. The blow-off groove can be connected to a compressed air source. Alternatively, a mechanical separating element such as a pushing member may be used.

[0055] As shown in FIG. 1, the coating unit 3 further includes a drive assembly or drive mechanism 6 for moving the holding member 5 along the holding arc A. In particular, the drive mechanism 6 includes a first drive unit 61 and a second drive unit 62 that move the holding member 5 along the holding arc A with a first vector component V1 in a first drive direction D1 and a second vector component V2 in a second drive direction D2, respectively. The drive units 61 and 62 may thus cooperate to function as an XY drive unit. In other words, the drive units 61 and 62 are controlled such that the vector components V1 and V2 generated by the respective drive units 61 and 62 in their respective drive directions D1 and D2 result in a complex or intricate movement of the holding member 5 along a curve that matches the radius and / or curvature of the holding arc A. In this example, the first drive direction D1 is perpendicular to the roll axis X. In this particular embodiment, the first drive direction D1 is vertical or substantially vertical. Further, in this example, the second drive direction D2 is perpendicular to the first drive direction D1. Thus, in this particular embodiment, the second drive direction D2 extends horizontally or substantially horizontally.

[0056] It should be noted that the aforementioned oblique contact angle H of the contact surface 51 can also be measured with respect to the first drive direction D1.

[0057] As shown in FIG. 3, the first drive unit 61 is arranged to move the holding member 5 by a first stroke S1 in the first drive direction D1. Similarly, the second drive unit 62 is arranged to move the holding member 5 by a second stroke S2 in the second drive direction D2. The first stroke S1 coincides with the roll axis X and reaches a stop or end point at a position away from or in front of an intermediate plane M that extends perpendicular to the first drive direction D1. In other words, the movement of the holding member 5 is limited to a position away from the intermediate plane M, particularly at a level that intersects the upper half of the coating roll 4. In this particular example, the holding member 5 reaches the bottom at an intermediate level somewhere in the upper half of the coating roll 4 when the first stroke S1 reaches its end point.

[0058] In this example, the first drive unit 61 is configured to act on the holding member 5 in the first drive direction D1 or parallel thereto. The second drive unit 62 is arranged at an angle oblique to the second drive direction D2. The drive mechanism 6 further includes a carriage 63 that supports or transports the first drive unit 61 and is movable in the second drive direction D2 along the guide 64. The second drive unit 62 is coupled to the carriage 63 and moves the carriage along the guide 64, thereby converting the oblique movement of the second drive unit into a linear movement of the carriage 63 in the second drive direction D2.

[0059] When the holding member 5 reaches the end point of the first stroke S1 or the bottom, the holding member 5 can only move further in the second drive direction D2. The end point of the second stroke S2 is selected such that the holding member 5 can move to a position spaced from, away from, or distant from the holding surface 41 in the second drive direction D2.

[0060] In this example, the first drive unit 61 and the second drive unit 62 include or are linear drive units, and the linear drive unit is particularly a pneumatic cylinder. While the holding member 5 moves in a follow-up manner along the holding arc A, the pneumatic cylinder is pressurized, and when the holding member 5 can move freely with respect to the application roll 4, the holding member 5 is urged to automatically follow the holding arc A in the first drive direction D1 and the second drive direction D2. The pressure is preferably kept constant at, for example, 1 bar.

[0061] FIG. 7 shows an alternative tire manufacturing apparatus 101 according to a second embodiment of the present invention. This apparatus differs from the aforementioned tire manufacturing apparatus 1 in that a holding member 105 is provided in the coating unit 103, and this holding member 105 particularly includes a pressing conveyor such as a hanger belt 150. The holding member 105 is provided with an infinite contact surface 151 that contacts the continuous strip 9 along the holding arc A, particularly an endless belt. The infinite contact surface 151 may be actively driven at the same speed or substantially the same speed as the continuous strip 9 to follow the continuous strip 9 at the holding position P on the coating roller 4, or as a result of the friction between the continuous strip 9 and the infinite contact surface 151, it may move passively together with the coating roller 4. The holding member 105 can be moved toward the coating roller 4 or away from the coating roller 4 in a first driving direction D1 by a first driving unit 161, particularly a linear driving unit such as a pneumatic cylinder.

[0062] Furthermore, the alternative tire manufacturing apparatus 101 differs from the aforementioned tire manufacturing apparatus 1 in that it further includes a sensor 107 for detecting the leading end LE of the continuous strip 9. Based on the detection of the leading end LE, the holding member 105 can be lowered to the leading end LE of the continuous strip 9 at an appropriate timing, that is, when the leading end LE enters the holding arc A. The sensor 9 may be an optical sensor, a photoelectric sensor, an optical sensor, an image sensor, or a height sensor. Alternatively, a temperature sensor may be used to detect an increase in heat indicating that the freshly extruded and hot leading end LE of the continuous strip 9 has passed. The temperature sensor can prevent false detection by the residual elastomer material leaking from the extruder 2.

[0063] The sensor 107 may be applied to the tire manufacturing apparatus 1 of FIGS. 1 - 6 to control the first driving unit 61 to move the holding member 5 toward the coating roll 4.

[0064] A method of applying the continuous strip 9 to the drum 8 using the aforementioned coating unit 3 will be briefly described with reference to FIGS. 1 - 6.

[0065] Figure 1 shows a situation where the length of the continuous strip 9 is newly extruded and supplied to the coating roll 4 until its leading end LE is located at or within the holding position P on the holding surface 41. In this example, the holding position P is initially located above the coating roll 4 and is hereinafter referred to as the zero-degree position around the roll axis X. The coating unit 3 and the drum 8 are spaced apart to provide room for the holding member 5 to move relative to the coating roll 4. The drive mechanism 6 is operated to move the holding member 5 to the starting position at the start of each stroke S1, S2. The holding member 5 is located above or directly above the leading end LE of the continuous strip 9 in the first driving direction D1.

[0066] Figure 2 shows a state where the first drive unit 61 is controlled to move the holding member 5 in the first driving direction D1 towards the coating roll 4 until the holding member 5 comes into contact or abuts against the leading end LE of the continuous strip 9 in the first driving direction D1. The holding member 5 presses or holds the leading end LE of the continuous strip 9 against the holding surface 41 at the holding position P, whereby the leading end LE can be sucked and securely held against the holding surface 41 in subsequent steps of the method.

[0067] Figure 3 shows a situation where, as indicated by the arrow R, the roller body 40 rotates and holds the continuous strip 9 on the holding surface 41 by suction, that is, by utilizing the reduced pressure in the first chamber 44. At the same time, the drive mechanism 6 is controlled to move the holding member 5 along the holding arc A, and while following the rotation of the roller body 40, holds the leading end LE of the continuous strip 9 at the holding position P with respect to the holding surface 41.

[0068] In Figure 4, the holding member 5 has reached the end point of the first stroke S1 and cannot move any further in the first driving direction D1. In other words, the holding member 5 has reached the end point of the holding arc A. The separating element 52 is actuated to separate the continuous strip 9 from the holding member 5, and at the same time, the second drive unit 62 has started to move the holding member 5 away from the holding surface 41 in the second driving direction D2.

[0069] Figure 5 shows a situation where the second drive unit 62 has moved the holding member 5 away from and / or distanced it from the application roll 4 in the second drive direction D2. The holding member 5 can be returned to the initial position shown in Figure 1.

[0070] Figure 6 shows a state where the first drive unit 61 has reversed and / or retreated to return the holding member 5 to the initial position. The drum 8 moves towards the application roll 4 and receives the leading end LE of the continuous strip 9 from the application roll 4. The extruder 2 continuously extrudes the continuous strip 9, and the application roll 4 continuously applies the continuous strip 9 by winding it around the drum 8 several times to form a tire component. During this process, the continuous strip 9 extends only over a part of the circumference of the application roll 4 before being applied to the drum 8.

[0071] It should be understood that the above description is included to explain the operation of the preferred embodiment and is not intended to limit the scope of the present invention. From the above description, many variations within the scope of the present invention will be apparent to those skilled in the art.

Explanation of Reference Numerals

[0072] 1 Tire manufacturing apparatus 2 Extruder 3 Coating unit 4 Application roll 40 Roller body 41 Holding surface 42 Suction port 43 Inner member 44 First chamber 45 Second chamber 5 Holding member 50 Finger tip 51 Contact surface 52 Pulling-away element 6 Drive mechanism 61 First drive unit 62 Second drive unit 63 Carriage 64 Guide 8 Drum 9 Continuous strip 101 Alternative Tire Manufacturing Apparatus 103 Coating Unit 105 Holding Member 150 Hagel Belt 151 Contact Surface 161 First Driving Unit 107 Sensor A Holding Arc C Circumferential Direction D1 First Driving Direction D2 Second Driving Direction E1 First Circumferential Cross-Section E2 Second Circumferential Cross-Section H Contact Angle LE Leading End M Intermediate Surface P Holding Position R Arrow S1 First Stroke S2 Second Stroke X Roll Axis V1 First Vector Component V2 Second Vector Component

Claims

1. 1. A coating unit for applying a continuous strip to a drum, the coating unit comprising a coating roll having a roller body rotatable about a roll axis and defining a holding surface extending circumferentially around the roll axis, the coating unit further comprising a holding member for holding the continuous strip in a holding position on the holding surface, the holding member being arranged to follow the continuous strip in the holding position on the holding surface along a holding arc of at least 10 degrees about the roll axis as the roller body rotates about the roll axis.

2. 2. The application unit according to claim 1, wherein the retention arc is at least 20 degrees, preferably at least 30 degrees.

3. The coating unit according to claim 1 or 2, further comprising a drive mechanism for moving the holding member along the holding arc.

4. The application unit according to claim 3 , wherein the drive mechanism is configured to move the holding member away from the holding surface after moving the holding member along the holding arc.

5. The application unit according to claim 3 or 4, wherein the drive mechanism comprises a first drive unit that moves the holding member along the holding arc in a first drive direction with a first vector component, and a second drive unit that moves the holding member in a second drive direction with a second vector component.

6. 6. The application unit of claim 5, wherein the first drive portion is arranged to move the holding member in the first drive direction through a first stroke, the first stroke terminating short of a mid-plane that coincides with the roll axis and extends perpendicular to the first drive direction.

7. The application unit according to claim 5 or 6, wherein the second drive portion is arranged to move the holding member only in the second drive direction away from the holding surface when the holding member reaches the end point of the first stroke.

8. The application unit according to claim 5 , wherein the first drive direction is perpendicular to the roll axis.

9. The application unit according to claim 5 , wherein the first drive direction is vertical or approximately vertical.

10. 10. An application unit according to any of claims 5 to 9, wherein the first drive and / or the second drive comprises a linear drive, preferably a pneumatic cylinder.

11. 10. The application unit according to any preceding claim, wherein the holding member comprises a finger, a pressure roll or a pressure conveyor adapted to contact the continuous strip at the holding position while causing the continuous strip to follow a holding arc.

12. 12. The application unit according to claim 5, wherein the holding member has a contact surface which contacts the continuous strip at the holding position on the holding surface, the contact surface extending at an oblique contact angle with respect to the first drive direction.

13. 10. An application unit according to any preceding claim, further comprising a separating element for separating the continuous strip from the holding member.

14. The application unit according to claim 13, wherein the separating element is a blow-off groove provided in the holding member.

15. 10. The application unit according to any preceding claim, wherein the application roll is further provided with a plurality of suction ports in the roller body for holding the continuous strip against the holding surface by suction.

16. 10. The coating unit of claim 9, wherein the roller body is annular, the coating roll further comprises an inner member concentrically arranged within the roller body, the roller body being rotatable in a circumferential direction around the inner member, the inner member comprising a first chamber in fluid communication with the plurality of suction ports at a first circumferential cross-section of the roller body, the first chamber being connectable to a reduced pressure source to hold the continuous strip against the holding surface at the first circumferential cross-section.

17. The application unit of claim 16 , wherein the retention arc at least partially overlaps the first circumferential cross section.

18. 18. The application unit of claim 16 or 17, wherein the retention arc overlaps the first circumferential cross section by at least 80%.

19. 19. The application unit according to claim 16, wherein the inner member comprises a second chamber in communication with the plurality of suction ports at a second circumferential cross section of the roller body, the second chamber being connectable to a source of compressed air for blowing the continuous strip off the holding surface at the second circumferential cross section.

20. The application unit of claim 19 , wherein the retention arc terminates before or at the second circumferential cross section.

21. 11. A tire building apparatus for applying a continuous strip to a drum, the tire building apparatus comprising an application unit according to any preceding claim, the tire building apparatus further comprising an extruder for continuously extruding the continuous strip onto the application roll, and the drum for continuously receiving the continuous strip from the application roll.

22. 21. A method for applying a continuous strip to a drum using an application unit according to any one of claims 1 to 20, said method comprising the steps of: rotating the applicator roll about the roll axis while holding the continuous strip on the holding surface by suction; and holding the continuous strip at the holding position on the holding surface with the holding member while causing the holding member to follow the continuous strip to the holding position on the holding surface along the holding arc as the roller body rotates about the roll axis.

23. The method further comprising:

23. The method of claim 22, further comprising the step of moving the retaining member away from the retaining surface after moving the retaining member along the retaining arc.

24. The method further comprising:

24. The method of claim 22 or 23, further comprising the step of pulling the continuous strip away from the retaining member after moving the retaining member along the retaining arc.

25. The method further comprising: continuously extruding the continuous strip onto the applicator roll; 25. The method of any of claims 22 to 24, further comprising the step of continuously applying the continuous strip onto the drum with the application roll.

26. 26. A method according to any of claims 22 to 25, wherein the continuous strip has a leading edge, the continuous strip being held in the holding position on the holding surface at the leading edge.

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