METHOD FOR PRODUCING A CONTINUOUS STRIP, A TIRE MANUFACTURING LINE AND COMPUTER PROGRAM PRODUCT - Patent application

Abstract

The present invention relates to a method for producing a continuous strip in a tire making line, the tire making line comprising at least one conveying unit for conveying the continuous strip along a conveying path through the tire making line, the method comprising: a) operating the tire manufacturing line in a tire manufacturing mode; b) controlling, in the tire building mode, the at least one transport unit to transport the continuous strip along the transport path in a transport direction; c) switching at least a portion of the tire building line, including the at least one transport unit, from the tire building mode to an interruption mode; d) controlling said at least one transport unit in said interrupted mode to repeatedly move said continuous strip back and forth along said transport path in said conveying direction and in a rearward direction opposite to said conveying direction; 1. A method for producing a continuous strip in a tire manufacturing line comprising: The invention further relates to a tire manufacturing line and a computer program product.

Description

[Background technology]

[0001] The present invention relates to a method, a tire production line and a computer program product for producing a continuous strip, in particular a continuous strip for use in the manufacture of green or unvulcanized tires.

[0002] In known tire manufacturing lines, apexes are produced by extruding a continuous strip of elastomeric or rubber material. As the continuous strip leaves the extruder, it is contracted on a contracting conveyor and then guided through a number of guide rollers onto a cooling drum. The continuous strip is finally cut to length at a cutting station to form individual apexes, which are then conveyed further downstream to be combined with beads to form bead apexes. A festunner is usually provided as a conditioning device between the continuous feed from the extruder and the discrete cut at the cutting station. Summary of the Invention

[0003] A drawback of known tire production lines is that the continuous strip of material fresh from the extruder is still relatively warm and soft when it passes on the shrinking conveyor and around the cooling drum, and therefore easily deforms. When the tire production line is running normally, deformation is usually not a problem, since the continuous strip is continuously moved and kept under sufficient tension to prevent sagging. However, if the tire production process is interrupted for any reason, the tire production line may stop and the relatively warm and soft continuous strip may remain stationary on the shrinking conveyor, guide rollers and cooling drums. After a while, parts of the continuous strip may settle and conform to the shape of the rollers that supported them. The longer the interruption, the more the continuous strip cools and the more difficult it is to smooth out the deformations resulting from the settling. This may cause further quality problems downstream.

[0004] Furthermore, the continuous strip may adhere to the rollers, making it difficult to restart the tire production line or causing a breakdown as the continuous strip becomes pulled between the rollers instead of being transported further over the rollers.

[0005] It is an object of the present invention to provide a method, a tire manufacturing line, and a computer program product for manufacturing a continuous strip, which can reduce or prevent persistent deformation and / or sticking of the continuous strip during downtime of the tire manufacturing line.

[0006] According to a first aspect, the present invention provides a method for producing a continuous strip in a tire making line, said tire making line comprising at least one conveying unit for conveying said continuous strip along a conveying path through said tire making line, said method comprising: a) operating the tire manufacturing line in a tire manufacturing mode; b) controlling, in the tire building mode, the at least one transport unit to transport the continuous strip along the transport path in a transport direction; c) switching at least a portion of the tire building line, including the at least one transport unit, from the tire building mode to an interruption mode; d) controlling said at least one transport unit in said interrupted mode to repeatedly move said continuous strip back and forth along said transport path in said conveying direction and in a rearward direction opposite to said conveying direction; 1. A method for producing a continuous strip in a tire manufacturing line comprising:

[0007] The reciprocating movement controlling the continuous strip in the interrupted mode effectively prevents the continuous strip from remaining stationary in a single or fixed position for long periods of time while still warm and soft during downtimes or stops of the tire production line. In particular, the continuous strip is subjected to repeated reciprocating movements such that different parts of the continuous strip are supported on different parts or areas of at least one transport unit over time. The reciprocating movement can prevent the continuous strip from settling into a stationary position on a transport unit and / or from locally conforming to the shape of the part of at least one transport unit supporting it. Furthermore, the reciprocating movement can smooth and / or reduce deformations, making it less likely that such deformations will cause quality issues further downstream.

[0008] In a preferred embodiment, in step c) at least one transport unit is controlled to stop moving the continuous strip along the transport path. By stopping the transport of the continuous strip at the end of the tire building mode, the interruption mode can be initiated in a controlled manner, independent of the transport of the continuous strip in the tire building mode.

[0009] More preferably, step d) is delayed from step c) by a time delay. Most preferably, the time delay is at least 10 seconds, preferably at least 30 seconds, most preferably at least 1 minute. In some cases, the tire building mode may be interrupted for a short period of time. A time delay may prevent initiation of the interruption mode if the tire building mode is stopped for a period of time that is shorter than the time delay.

[0010] In another embodiment, in step d), the continuous strip returns to the same or substantially the same position along the transport path after each repetition of the back and forth movement, so that the net movement of the continuous strip in the transport direction can be kept close to or at zero.

[0011] Alternatively, in step d), the continuous strip returns to a different position along the transport path after each repetition of the back and forth movement, thereby ensuring that different sections of the continuous strip are supported on at least one transport unit over time.

[0012] In another embodiment, in step d), the continuous strip is reciprocated over a first distance in a conveying direction and a second distance in a retreating direction.

[0013] Preferably, in step d), the second distance is equal to the first distance for each repetition of said back and forth movement of the continuous strip, so that after each repetition, said amount of movement is zero or close to zero.

[0014] In a further embodiment, in step d), the first distance remains constant for all repetitions of said back and forth movement of the continuous strip. Said back and forth movement can thus be a constant and / or periodic motion, in particular having a constant amplitude for each repetition.

[0015] Alternatively, in step d), the first distance is variable between repetitions of the back and forth movement of the continuous strip. Preferably, in step d), the first distance is changed in steps between repetitions of the back and forth movement of the continuous strip. For example, the first distance may be changed in response to changes in properties of the continuous strip over time, such as when the continuous strip cools and hardens over time.

[0016] In a further embodiment, the first distance and / or the second distance is at least 3 centimeters, preferably at least 5 centimeters, most preferably at least 8 centimeters. Such a minimum distance may already be sufficient to reduce and / or prevent local deformations of said continuous strip.

[0017] In another embodiment, the back and forth movement of the continuous strip in step d) is a periodic movement, i.e., with a constant interval that ensures that the continuous strip is kept in regular and / or continuous movement. Alternatively, the back and forth movement of the continuous strip in step d) is a non-periodic movement, i.e., with a variable interval. This is useful when less movement is required over time as the continuous strip cools and / or hardens.

[0018] In another embodiment, the continuous strip in the tire making mode is moved in the conveying direction at a production speed, and the continuous strip in the interrupted mode is moved back and forth in step d) at an interrupted speed of less than 80%, preferably less than 60%, of the production speed, such that an operator can safely enter the tire making line despite the continuous strip moving back and forth.

[0019] In other embodiments, the back and forth movement of the continuous strip in step d) is automatically and / or pre-programmed and controlled. Thus, the back and forth movement does not require human intervention or supervision. Further, the pause mode may be initiated automatically, without human intervention or trigger, in response to the tire manufacturing line being stopped.

[0020] In another embodiment, the tire manufacturing line is switched from the tire manufacturing mode to the interruption mode in response to an interruption signal. Preferably, the interruption signal is triggered by either an automatically detected error in the tire manufacturing line or a user input in a human-machine interface. Thus, if the tire manufacturing line is stopped as a result of an error or user input, the interruption mode can be initiated automatically without human intervention or triggering.

[0021] In another embodiment, the at least one transport unit comprises a first transport unit and a second transport unit located downstream of the first transport unit along the transport path. The two transport units can be controlled together and / or can cooperate to move the continuous strip back and forth in the interrupted mode. In particular, the length of the continuous strip extending along the transport path between the first transport unit and the second transport unit can be moved back and forth in a controlled manner by controlling both transport units in the interrupted mode.

[0022] Preferably, in step d), the first transport unit and the second transport unit are controlled synchronously or substantially synchronously to move the continuous strip back and forth, so that when one transport unit is pushing a length of the continuous strip between the transport units, the other transport unit can pull said length and vice versa.

[0023] Alternatively, in step d), the first and second transport units are alternately controlled to move the continuous strip in the backward and forward directions, respectively, so that when one transport unit is being pulled, the other transport unit is free to rotate and / or passively follow the continuous strip.

[0024] In another embodiment, the tire manufacturing line further comprises a tensioning device for tensioning the continuous strip between a first transport unit and a second transport unit, the method further comprising the steps of: e) before or during step d), controlling the first transport unit and the second transport unit to generate an extra length in the continuous strip at the tensioning device.

[0025] In other words, the tire manufacturing line further comprises a tensioning device movable between a low tension state and a high tension state to variably tension the continuous strip, the method further comprising the steps of: e) controlling the tensioning device to move from a high tension state towards and / or to a low tension state.

[0026] In particular, when the continuous strip is a cordless strip and is stationary, the continuous strip may begin to stretch uncontrollably if maintained under tension. By creating excess length in the continuous strip or controlling the tensioning device to move toward a lower tension state, the tension created in the continuous strip by the tensioning device can be reduced to reduce or prevent excessive stretching of the continuous strip at the tensioning device.

[0027] In another embodiment, at least one of the conveying units comprises a conveying roller. The cylindrical shape of the conveying roller may cause deformations in the continuous strip. Furthermore, the conveying rollers are typically spaced apart, allowing the continuous strip to sag between the conveying rollers. The method according to the invention may reduce or prevent such deformations and / or sagging.

[0028] In another embodiment, the tire production line comprises an extruder for extruding the continuous strip, and at least one transport unit comprises a shrink conveyor for receiving the continuous strip from the extruder. Such a shrink conveyor typically includes conveyor rollers. Thus, the method according to the invention may have similar technical advantages as the previously described embodiments.

[0029] In another embodiment, at least one transport unit comprises a cooling drum. Such a cooling drum typically comprises a number of guide rollers for guiding the continuous strip in a number of windings around the cooling drum. Thus, the method according to the invention can have similar technical advantages as the previously described embodiments.

[0030] In another embodiment, at least one of the transport units comprises a festoon. Such a festoon typically comprises transport rollers. Thus, the method according to the invention can have the same technical advantages as the previously described embodiments.

[0031] In another embodiment, the tire manufacturing line comprises at least one downstream station downstream of at least one of the transport units, and at least one of the downstream stations, in particular a festooner, is controlled in the interrupted mode to hold the continuous strip stationary along the transport path in the transport direction. At the downstream station, the continuous strip may have cooled to such an extent that it is no longer easily deformed when held stationary. Thus, the continuous strip may be held stationary at the at least one downstream station without suffering any adverse effects thereon.

[0032] In another embodiment, the continuous strip is a cordless strip, in particular for producing apexes, which in the freshly extruded state are prone to deformation when left stationary, and therefore the advantageous effects of the method according to the invention are even greater for such cordless strips.

[0033] Alternatively, said continuous strip is a cord-reinforced strip, in particular for producing breakers or body plies. Although cord-reinforced strips are less likely to deform when at rest, the freshly extruded elastomeric material with embedded cords can still deform and can lead to misalignment of the cords in said elastomeric material when at rest for long periods of time. Thus, the method according to the invention can also have advantageous effects when applied to cord-reinforced strips.

[0034] According to a second aspect, the present invention provides a tyre manufacturing line for producing a continuous strip, said tyre manufacturing line comprising at least one transport unit for transporting said continuous strip along a transport path through said tyre manufacturing line, and a control unit operatively connected to the at least one transport unit, said control unit configured to perform the steps of a method according to any one of the embodiments of the first aspect of the invention.

[0035] According to a third aspect, the present invention provides a computer program product comprising a non-transitory computer readable medium carrying instructions which, when executed by a processor, cause a tyre manufacturing line according to the second aspect of the invention to carry out the steps of the method according to any one of the embodiments of the first aspect of the invention.

[0036] The various aspects and features described and illustrated in this specification may be applied individually to the extent possible. These individual aspects, in particular those aspects and features described in the accompanying dependent claims, may be the subject of divisional patent applications. [Brief description of the drawings]

[0037] The invention will now be explained on the basis of exemplary embodiments shown in the accompanying schematic drawings.

[0038] [Figure 1] FIG. 1 is a side view of a tire manufacturing line according to the present invention operating in a tire manufacturing mode. [Diagram 2]FIG. 2 is a side view of the tire manufacturing line of FIG. 1 during a switchover from the tire manufacturing mode to an interruption mode. [Diagram 3] FIG. 3 is a side view of the tire manufacturing line of FIG. 1 operating in the interrupted mode. [Figure 4] FIG. 4 is a graph illustrating different drive profiles for controlling the tire manufacturing line of FIG. 3 in the interrupted mode. [Diagram 5] FIG. 5 is a flow chart illustrating method steps for producing a continuous strip on the tire manufacturing line of FIG. Detailed Description of the Invention

[0039] FIG. 1 illustrates an exemplary embodiment of the present invention, a tire manufacturing line 100 for producing a continuous strip 9 from which tire components are cut for making and / or assembling green or unvulcanized tires.

[0040] The tire making line 100 comprises an extruder 5 for extruding a continuous strip 9, and one or more transport units 1, 2 for transporting the continuous strip 9 in a transport direction A along a transport path G towards one or more downstream stations 4. In this example, the one or more downstream stations 4 comprise a festooner 41 and a cutter 42. The cutter 42 is configured to cut the continuous strip 9 to length. The cut lengths of the continuous strip 9 can then be used in a tire building process (not shown) downstream of the cutter 42. The festooner 41 is used as a buffer between the continuous output of the extruder 5 and the discontinuous or intermittent cutting operation at the cutter 42.

[0041] In this example, a continuous strip 9 is used to form a filler strip or apex. The apex is formed into an annular shape and is combined with the beads in a bead-apex drum to form a bead-apex assembly in a manner known per se. The apex consists of a body of elastomeric or rubber material with a triangular or tapered cross section. Usually, no reinforcing cords are embedded in the apex.

[0042] However, the invention may be applied mutatis mutandis to other continuous strips used in tire construction, such as gum strips and cord reinforcement strips, such as breaker plies, body plies, cap strips, run-flat reinforcement strips, and the like.

[0043] In this example, as shown in FIG. 1, the one or more transport units 1, 2 are a first transport unit 1 and a second transport unit 2 downstream of the first transport unit 1 in a transport direction A.

[0044] It will be appreciated that the scope of the present invention includes tire manufacturing lines having a single conveying unit, or tire manufacturing lines having two or more conveying units, where one or more of said conveying units may be selected from the group consisting of, but not limited to, roller conveyors, belt conveyors, cooling drums, and festooners.

[0045] More specifically, the first transport unit 1 comprises a shrinking conveyor 10 having a plurality of conveyor rollers 11 configured to be able to shrink the continuous strip 9 just extruded by the extruder 5. Each conveyor roller 11 has a roller diameter, at least one conveyor roller 11 having a minimum roller diameter E compared to the other conveyor rollers 11. The tire production line 100 comprises a first drive device 61 for rotatably driving the at least one conveyor roller 11 in a first drive direction R1 and in a second drive direction R2 opposite to the first drive direction R1.

[0046] The second conveyor unit 2 includes a cooling drum 20 for cooling the continuous strip 9. The tire production line 100 is provided with a second drive device 62 for driving the cooling drum 20 to rotate in both drive directions R1, R2.

[0047] In this exemplary embodiment, the second transport unit 2 further comprises one or more guide rollers 21 for guiding the continuous strip 9 around said cooling drum 20 in one or more windings.

[0048] As shown in Fig. 1, the continuous strip 9 preferably has one or more slack portions or passes through one or more loops or free loops 31, 32, 33. In this example, a first loop 31 is provided between the extruder 5 and the first conveying unit 1, a second loop 32 is provided between the first conveying unit 1 and the second conveying unit 2, and a third loop 33 is provided between the second conveying unit 2 and one or more downstream stations 4. Optionally, one or more buffer members (not shown) may be provided in the loops 31, 32, 33 in order to actively control the length of the continuous strip 9 in the loops 31, 32, 33. The buffer members may be, for example, dancer rollers.

[0049] Optionally, the second conveying unit 2 can be equipped with a tensioning device 22 for controlling the tension of the continuous strip 9 in the region between the first conveying unit 1 and the second conveying unit 2, in particular in the aforementioned second loop 32. In this embodiment, the tensioning device 22 is composed of a tensioning roller 23 and a tensioning arm 24 for carrying said tensioning roller 23 relative to the hinge point. The tensioning roller 23 is passively rested on the continuous strip 9 in the second loop 32 immediately upstream of the cooling drum 20, and the tensioning arm 24 passively adapts its orientation depending on the resting position of the tensioning roller 23 on the continuous strip 9 between a high tension state as shown in FIG. 1 and a low tension state as shown in FIG. 2. Depending on the orientation of the tensioning arm 24 with respect to the hinge point, the reaction force of the continuous strip 9 supporting the weight of the tensioning roller 23 can be decomposed into components including a tension component in the direction of the continuous strip 9 which automatically changes depending on the orientation of the tensioning arm 24 with respect to the hinge point.

[0050] It will be appreciated that different tensioning devices may be used to generate or control tension in the continuous strip 9, such as a conventional dancer roller.

[0051] In this example, the tire manufacturing line 100 further comprises a third drive 63 for driving the festooner 41 in both drive directions R1, R2.

[0052] As further shown in FIG. 1 , tire manufacturing line 100 comprises a timer 7 and a control unit 8. Control unit 8 is functionally, electronically and / or operatively connected to drives 61, 62, 63 and timer 7. Control unit 8 comprises a computer readable medium, e.g., a memory, and a processor (generally indicated by box 80). The computer readable medium is configured to retain instructions that, when executed by the processor, cause tire manufacturing line 100 to perform method steps for producing a continuous strip 9, which are described in more detail below. In other words, the method steps may be pre-configured, pre-programmed and / or automatically performed.

[0053] Figures 1-3 show a tire manufacturing line 100 during steps of a method for producing a continuous strip 9 in the tire manufacturing line 100. Figure 5 is a flow chart illustrating the logic behind the steps of the method.

[0054] Figure 1 shows a situation in which the tire making line 100 is running or operating in a tire making mode (step S1 in Figure 5). The control unit 8 controls the drives 61, 62, 63 to drive the first conveying unit 1, the second conveying unit 2 and the festooner 41 in a first driving direction R1, which corresponds to or results in the conveying of the continuous strip 9 in a conveying direction A from the extruder 5 towards one or more downstream stations 4. In other words, when the tire making line 100 is operating normally, i.e. when there are no faults or interruptions, the continuous strip 9 is moved only in the forward or downstream direction.

[0055] Fig. 2 shows a situation (step S2 in Fig. 5) in which the tire making line 100 is switched from a tire making mode (step S1 in Fig. 5) to an interrupt mode (step S5 in Fig. 5) in response to an interrupt signal H, represented diagrammatically in Fig. 2 by an exclamation mark. The interrupt signal H may be triggered by an automatically detected malfunction or error in the tire making line 100 or alternatively by a user input at a human-machine interface (not shown). Upon receiving the interrupt signal H, the control unit 8 controls the drives 61, 62, 63 to slow down and / or stop the conveyance of the continuous strip 9 in the conveying direction A along the conveying path G as soon as possible, thus preventing damage to the continuous strip 9 and / or the tire making line 100.

[0056] Optionally, the control unit 8 is configured to control the drives 61, 62, 63 to reduce the tension in the continuous strip 9 as much as possible before or immediately after stopping the transport of the continuous strip 9. The control unit 8 can, for example, control the first drive 61 and the second drive 62 to rotate in the first drive direction R1 and the second drive direction R2, respectively, such that an additional or excess length of the continuous strip 9 is fed to the second loop 32. In other words, slack is introduced into the continuous strip 9 in the tensioning device 22. As a result, the tension arm 24 of the tensioning device 22 is lowered to a low position or its lowest position, which corresponds to a low tension state, thereby reducing the tension generated in the continuous strip 9 by the weight of the tensioning roller 22.

[0057] Fig. 3 shows a situation in which the tire production line 100 is operated in interrupted mode (step S5 in Fig. 5). In interrupted mode, the control unit 8 is configured to automatically control the at least one transport unit 1, 2 to repeatedly move back and forth or oscillate the continuous strip 9 along the transport path G in a conveying direction A and in a backward direction B opposite to the conveying direction A, hereinafter referred to as "back and forth movement" M or alternatively as "oscillating movement". The continuous strip 9 is moved in the conveying direction A over a first distance D1 and in the backward direction B over a second distance D2 opposite to the first distance D1.

[0058] Note that the "forward / backward movement" M does not necessarily start with a "backward" movement. The interruption mode can also start with a "forward" movement. However, starting with a "backward" movement is preferred since it reduces rather than increases the tension in the continuous strip 9.

[0059] In this embodiment, both the first transport unit 1 and the second transport unit 2 are controlled synchronously or substantially synchronously to move the continuous strip 9 back and forth M. In other words, both the first transport unit 1 and the second transport unit 2 are driven simultaneously in a first driving direction R1 to transport the continuous strip 9 in a conveying direction A, and both are driven simultaneously in a second driving direction R2 to transport the continuous strip 9 in a backward direction B. Essentially, when one transport unit 1,2 is pushing the length of the continuous strip 9 between the transport units 1,2, the other transport unit 1,2 is pulling, and vice versa.

[0060] Alternatively, the first transport unit 1 and the second transport unit 2 are alternately controlled to move or pull M the continuous strip 9 in a backward direction B and a conveying direction A, respectively. Effectively, when one of the transport units 1, 2 is pulling, the other is free to rotate and / or passively follow the continuous strip 9.

[0061] In yet another alternative embodiment, the first transport unit 1 and the second transport unit 2 can be controlled independently, i.e. the back and forth movement of the continuous strip 9 in one transport unit 1, 2 is not limited by the back and forth movement in the other transport unit 1, 2. Length variations can be absorbed by a free loop between the transport units 1, 2.

[0062] In the above embodiment, the control unit 8 controls the drives 61, 62 of the transport units 1, 2 to move the continuous strip 9 with a back and forth movement M. Alternatively, the control unit 8 may operate another mechanical device, for example a pendulum, in one or both of the transport units 1, 2 to interact with the continuous strip 9 and generate the back and forth movement M.

[0063] Preferably, the continuous strip 9 returns to the same or substantially the same position along the transport path G after each repetition of the reciprocating movement M. In other words, the net movement of the continuous strip 9 is zero or substantially zero. In any event, the net movement is substantially or significantly less than the movement of the continuous strip 9 in the tire building mode.

[0064] Alternatively, the continuous strip 9 may be returned to a different position along the conveying path G after each repetition, in other words the continuous strip 9 may be moved progressively in the conveying direction A or in the backward direction B so that different sections of the continuous strip 9 are supported by each conveying unit 1, 2 over time.

[0065] The graph of FIG. 4 shows a first drive profile P, a second drive profile P' and a third drive profile P" for controlling the position (on the "X" axis) of a continuous strip 9 over time (on the "T" axis).

[0066] The upward slope of the drive profiles P, P', P" represents the movement of the continuous strip 9 in the conveying direction A, while the downward slope of the drive profiles P, P', P" represents the movement of the continuous strip 9 in the reverse direction B. Note that the second distance D2 is equal to the first distance D1 for each repetition of the back and forth movement M of the continuous strip 9, resulting in the aforementioned net zero movement.

[0067] The first distance D1 or the second distance D2 is at least 3 centimeters, preferably at least 5 centimeters, most preferably at least 8 centimeters. In this example, the distance D1, D2 is at least equal to the smallest roller diameter E of the rollers 11, 21 on which the continuous strip 9 is supported in the first transport unit 1 and / or the second transport unit 2.

[0068] In this example, the back and forth movement M of the continuous strip 9 in step d) is sinusoidal. Alternatively, the reciprocating movement M may have a truncated sinusoidal shape (i.e. with a short delay between the movement of the continuous strip 9 in the conveying direction A and the movement in the retreating direction B) or a non-sinusoidal shape, such as a trapezoidal profile or a higher order curve, such as a quartic curve.

[0069] The first drive profile P represents a constant back and forth movement M. In other words, in all repetitions of the back and forth movement M, the first distance D1 and the second distance D2 are constant. The second drive profile P' represents a back and forth movement whose amplitude decreases over time. In other words, the distances D1, D2 traveled by the continuous strip 9 are decreased during the repetitions of the back and forth movement M. The third drive profile P'' represents a back and forth movement whose amplitude increases over time. In other words, the distances D1, D2 traveled by the continuous strip 9 are increased during the repetitions of the back and forth movement M.

[0070] In all drive profiles P, P', P'', the reciprocating motion M is a periodic motion, meaning that the motion is repeated at regular or regular intervals I. However, it will be understood that the period of repetition can also be varied in a non-periodic manner. For example, the interval I can be increased or decreased in stages.

[0071] In this example, as shown in FIG. 5, a time delay W is introduced (step S3) between the tire building mode (step S1) and the interruption mode (step S5) based on an input from a timer 7. The timer 7 is activated at the moment of changeover (step S2) or shortly thereafter, for example when the continuous strip 9 stops in the conveying direction A. Preferably, the time delay W is at least 10 seconds, more preferably at least 30 seconds, most preferably at least 1 minute. In step S4, it is checked whether the tire building line 100 has been switched back to the tire building mode before the time delay W has elapsed, and if yes (see arrow "Y"), the interruption mode (step S5) is cancelled and the flow chart returns to the tire building mode (step S1). If no (see arrow "N"), the aforementioned interruption mode (step S5) is initiated.

[0072] In step S6, the tire manufacturing line 100 switches back from the interrupt mode to the tire manufacturing mode (see arrow "Y") upon receiving a switchback signal from the human machine interface or in response to automatically detecting that the fault or error that triggered the interrupt signal H has been resolved. The interrupt mode (step S5) continues as long as a switchback signal has not been received.

[0073] In the example shown in Figure 3, the downstream station 4 immediately downstream of the third loop 33 is controlled in the interrupted mode to keep the continuous strip 9 stationary in the conveying direction A along the conveying path G. However, it will be understood that, if necessary, at least one of said downstream stations 4, for example the festooner 41, can be controlled as if it were a conveying unit, similar to the above-mentioned conveying units 1, 2, to move the continuous strip 9 back and forth in the interrupted mode, with the same technical effect.

[0074] In particular, the festooner 41 may be used to absorb and dispense varying lengths of the continuous strip 9 upstream of the festooner 41 to minimize or eliminate the formation of loops in the strip 9 and / or to eliminate the need for loops immediately upstream of the festooner 41.

[0075] In yet another embodiment, the festooner 41 is considered to be one of the one or more transport units 1,2, in which case any changes in the length of the strip 9 are absorbed in a loop downstream of the festooner 41, for example a dancer roller (not shown) between the festooner 41 and the cutter 42. This has the added advantage that the continuous strip 9 can be moved repeatedly back and forth across the festooner 41, thereby reducing the risk of the continuous strip 9 adhering to any part of the festooner 41.

[0076] It should be understood that the above description is included to illustrate the operation of the preferred embodiments and is not intended to limit the scope of the invention. From the above discussion, many variations will be apparent to those skilled in the art that would fall within the scope of the invention. [Explanation of symbols]

[0077] 1 First conveying unit 10 Shrinking Conveyor 11 Conveyor roller 2 Second conveying unit 20 Cooling drum 21 Guide roller 22 Tensioning device 23 Tension roller 24 Tension Arm 31 Loop 32 Loop 33 Loop 4. Downstream Station 41 Festuna 42 Cutter 5. Extruder 61 First Drive Unit 62 Second Drive Unit 63 Third Drive Unit 7. Timer 8. Control Unit 80 Computer-Readable Medium and Processor 9 Continuous Strips 90 Apex 100 tire production lines A Conveying direction B Reverse direction D1 First distance D2 Second distance E Minimum roller diameter G Transport route H interrupt signal I Interval M Move forward and backward P Drive Profile P' Alternative drive profile P” Yet another drive profile R1 First drive direction R2 Second drive direction S1 Step "Operate the tire production line in tire production mode" S2 Step "Switch the tire production line from tire production mode to interruption mode" S3 Step "Timer input" Step S4: "Should the tire production line be switched back before the delay time has elapsed?" S5 Step "Interrupt mode: Repeat back and forth movement of continuous strips" S6 Step "Switchback signal received?" T Time W Time Delay X position

Claims

1. A method for producing a continuous strip (9) in a tire manufacturing line (100), said tire manufacturing line (100) comprising at least one conveying unit (1, 2) for conveying said continuous strip (9) along a conveying path (G) through said tire manufacturing line (100), said method comprising the steps of: a) operating the tire manufacturing line (100) in a tire manufacturing mode (S1); b) controlling said at least one conveying unit (1, 2) in said tire building mode (S1) to convey said continuous strip (9) along said conveying path (G) in a conveying direction (A); c) switching (S2) at least a part of the tire production line (100) including the at least one transport unit (1, 2) from the tire production mode (S1) to an interruption mode (S5); d) controlling said at least one transport unit (1, 2) in said interrupted mode (S5) to repeatedly move (M) said continuous strip (9) back and forth along said transport path (G) in said transport direction (A) and in a retreating direction (B) opposite to said transport direction (A); A method for producing a continuous strip (9) in a tire production line (100), comprising:

2. 2. The method according to claim 1, wherein the at least one transport unit (1, 2) is controlled in step c) to stop the movement of the continuous strip (9) along the transport path (G).

3. 3. The method of claim 2, wherein step d) is delayed (S3) from step c) by a time delay (W).

4. 4. The method of claim 3, wherein the time delay (W) is at least 10 seconds, preferably at least 30 seconds, and most preferably at least 1 minute.

5. 5. A method according to any one of the preceding claims, wherein the continuous strip (9) returns to the same or substantially the same position along the transport path (G) after each repetition of the back and forth movement (M) in step d).

6. 5. A method according to any one of the preceding claims, wherein the continuous strip (9) returns to a different position along the transport path (G) after each repetition of the back and forth movement (M) in step d).

7. 7. The method according to any one of claims 1 to 6, wherein the continuous strip (9) is moved back and forth in step d) over a first distance (D1) in the conveying direction (A) and a second distance (D2) in the retreating direction (B).

8. 8. The method according to claim 7, wherein said second distance (D2) is equal to said first distance (D1) for each repetition of said back and forth movement (M) of said continuous strip (9) in step d).

9. 9. The method according to claim 7 or 8, wherein said first distance (D1) remains constant over all repetitions of said back and forth movement (M) of said continuous strip (9) in step d).

10. 9. The method according to claim 7 or 8, wherein the first distance (D1) is variable between repetitions of the back and forth movement (M) of the continuous strip (9) in step d).

11. 11. The method according to claim 10, wherein the first distance (D1) is incrementally changed between repetitions of the back and forth movement (M) of the continuous strip (9) in step d).

12. 12. The method according to any one of claims 7 to 11, wherein the first distance (D1) and / or the second distance (D2) is at least 5 centimeters, preferably at least 8 centimeters.

13. 13. A method according to any one of the preceding claims, wherein the back and forth movement (M) of the continuous strip (9) in step d) is a cyclic movement.

14. 13. The method according to any one of the preceding claims, wherein the back and forth movement (M) of the continuous strip (9) in step d) is a non-periodic movement.

15. 15. The method according to any one of claims 1 to 14, wherein in the tire building mode, the continuous strip (9) is moved in the conveying direction (A) at a production speed, and wherein in the interrupted mode, the continuous strip (9) is moved back and forth in step d) at an interrupted speed of less than 80%, preferably less than 60%, of the production speed.

16. 16. The method according to any one of the preceding claims, wherein the back and forth movement (M) of the continuous strip (9) in step d) is automatically controlled.

17. 17. The method according to any one of the preceding claims, wherein the back and forth movement (M) of the continuous strip (9) in step d) is preprogrammed.

18. 18. The method according to any one of the preceding claims, wherein the tire manufacturing line (100) is switched (S2) from the tire manufacturing mode (S1) to the interruption mode (S5) in response to an interruption signal (H).

19. 20. The method of claim 18, wherein the interrupt signal (H) is triggered by one of an automatically detected error in the tire manufacturing line (100) or a user input in a human machine interface.

20. 20. The method according to any one of claims 1 to 19, wherein the at least one transport unit (1, 2) comprises a first transport unit (1) and a second transport unit (2) located downstream of the first transport unit (1) along the transport path (G).

21. 21. The method according to claim 20, wherein the first transport unit (1) and the second transport unit (2) are controlled synchronously or substantially synchronously to move (M) the continuous strip (9) back and forth in step d).

22. 21. The method according to claim 20, wherein the first transport unit (1) and the second transport unit (2) are alternately controlled in step d) to move (M) the continuous strip (9) in the backward direction (B) and in the conveying direction (A), respectively.

23. The tire manufacturing line (100) further comprises a tensioning device (22) for tensioning the continuous strip (9) between the first conveying unit (1) and the second conveying unit (2), and the method further comprises the steps of: e) controlling the first conveying unit (1) and the second conveying unit (2) before or during step d) to create an extra length in the continuous strip (9) at the tensioning device (22).

23. The method of any one of claims 1 to 22, further comprising:

24. The tire manufacturing line (100) further comprises a tensioning device (22) movable between a low tension state and a high tension state for variably tensioning the continuous strip (9), and the method further comprises the steps of: e) controlling the tensioning device (22) to move from the high tension state towards the low tension state and / or from the high tension state to the low tension state.

24. The method of claim 1, further comprising:

25. 25. The method according to any one of the preceding claims, wherein the at least one transport unit (1, 2) comprises a conveyor roller (11).

26. 26. The method according to any one of claims 1 to 25, wherein the tire manufacturing line (100) comprises an extruder (5) for extruding the continuous strip (9) and the at least one conveying unit (1) comprises a contracting conveyor (10) for receiving the continuous strip (9) from the extruder (5).

27. 27. The method according to any one of the preceding claims, wherein the at least one transport unit (1, 2) comprises a cooling drum (20).

28. 28. The method according to any one of the preceding claims, wherein the at least one transport unit (1, 2) comprises a festoon (41).

29. 29. The method according to any one of claims 1 to 28, wherein the tyre manufacturing line (100) comprises at least one downstream station (4) downstream of the at least one transport unit (1, 2), and wherein the at least one downstream station (4) is controlled in the interruption mode (S5) to hold the continuous strip (9) stationary in the transport direction (A) along the transport path (G).

30. 30. The method according to claim 29, wherein the at least one downstream station (4) comprises a Festner (41).

31. 31. The method according to any one of the preceding claims, wherein the continuous strip (9) is a cordless strip, in particular a cordless strip for producing an apex.

32. 31. The method according to any one of claims 1 to 30, wherein the continuous strip is a cord-reinforced strip, in particular a cord-reinforced strip for producing breaker or body plies.

33. A tire manufacturing line (100) for manufacturing a continuous strip (9), said tire manufacturing line (100) comprising: at least one conveying unit (1, 2) for conveying said continuous strip (9) along a conveying path (G) through said tire manufacturing line (100); a control unit (8) operatively connected to said at least one transport unit (1, 2), The control unit (8) is configured to carry out the steps (S1 to S6) of the method according to any one of claims 1 to 32. A tire manufacturing line (100) for producing a continuous strip (9).

34. 34. A computer program product comprising a non-transitory computer readable medium carrying instructions that, when executed by a processor (80), cause a tire manufacturing line (100) according to claim 33 to perform the steps (S1 to S6) of the method according to any one of claims 1 to 32.

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