BACKGROUND

The invention relates to a method and an assembly for applying a tire component, in particular a breaker ply, to a drum.

WO 2015/069102 A1 discloses a method for centering a tire component, in particular a breaker ply, with respect to a drum. The method comprises the steps of placing the tire component on a first conveyor and conveying it towards a second conveyor, determining the position of a first longitudinal edge, transversely moving the first conveyor and thereby aligning the first longitudinal edge along a first reference on the second conveyor, conveying the tire component from the first conveyor onto the second conveyor while determining the position of a second longitudinal edge, wherein the tire component has a center between the first longitudinal edge and the second longitudinal edge, conveying the tire component from the second conveyor towards the drum, laterally moving the drum to align the center of the tire component with a center of a desired application position of the tire component on the drum, and conveying the tire component from the second conveyor onto the drum.

The known method further comprises the step of determining for a number of stored lateral positions of the leading edge, at a predetermined distance upstream of the stored lateral position, the lateral position of the trailing edge, and aligning said lateral position of the trailing edge to the stored lateral position of the leading edge by transversely moving the first conveyor with respect to the second conveyor.

Through said transverse movement of the first conveyor, any given point on the trailing edge can be corrected to a lateral position at which the length of the tire component between the lateral positions as measured at the leading edge and the trailing edge matches the predetermined distance. The predetermined distance corresponds to the desired circumferential length of the tire component when the tire component is applied to the drum.

Although the method as described above improves the splicing, the length of the trailing edge between two consecutive lateral positions may not always be equal to the length of the leading edge between the same lateral positions at the leading edge. Hence, by laterally moving the trailing edge, a difference in length of the trailing edge with respect to the leading edge may be inadvertently stretched or compressed when splicing, resulting in unpredictable behavior, such as waving.

It is an object of the present invention to provide a method and an assembly for applying a tire component, in particular a breaker ply, to a drum, wherein the splicing can be improved.

SUMMARY OF THE INVENTION

According to a first aspect, the invention provides a method for applying a tire component, in particular a breaker ply, from an apply member onto a receiving member, wherein the tire component comprises a leading edge, a trailing edge and a first longitudinal edge and a second longitudinal edge extending between the leading edge and the trailing edge, wherein the method comprises the steps of;

a) receiving the tire component on the apply member;

b) detecting a plurality of leading endpoints at the leading edge and detecting, for each leading endpoint, a trailing endpoint at the trailing edge that together with the respective leading endpoint forms a pair of endpoints;

c) determining the relative positioning between the leading endpoint and the trailing endpoint for each pair of endpoints;

d) driving the apply member at an apply speed to transfer the tire component in a transfer direction onto the receiving member while driving the receiving member at a receiving speed; and

e) splicing the trailing edge to the leading edge on the building drum;

wherein the ratio between the apply speed and the receiving speed is adjusted for each pair of endpoints during the transfer in step d) in the order in which said pairs of endpoints are spliced in step e) to improve the relative positioning of each pair of endpoints for splicing.

Preferably, the receiving member is the building drum, wherein the building drum is rotated at the receiving speed.

By adjusting the aforementioned ratio, the tire component can be locally stretched or compressed between the pair of endpoints to reposition said pair of endpoints for splicing, e.g. to close an open splice or to reduce an overlapping splice.

Preferably, the leading endpoints and the trailing endpoints are distributed over the leading edge and the trailing edge, respectively, with the same interval. Hence, the trailing endpoints can be accurately spliced to the leading endpoints without compressing or stretching the intervals between the respective endpoints on the leading edge and the trailing edge.

In another preferred embodiment the tire component has a length between the leading endpoint and the trailing endpoint of each pair of endpoints on the apply member, wherein said length without adjustment of the ratio will either result in an overlapping splice, an open splice or a butt-splice on the building drum, wherein the ratio is adjusted such that:

the receiving speed is higher than the apply speed when transferring one of the pairs of endpoints which would result in an open splice; and

the receiving speed is lower than the apply speed when transferring one of the pairs of endpoints which would result in an overlapping splice. Hence, any openings in the splice can be reduced while any overlap in the splice can be decreased, thereby improving the positioning of each pair of endpoints for splicing.

In another embodiment the leading endpoint and the trailing endpoint of at least one of the pairs of endpoints are spaced apart on the apply member in a lateral direction transverse or perpendicular to the transfer direction, wherein during step d) the apply member and the receiving member are moved relative to each other in the lateral direction when transferring said at least one pair of endpoints to reduce the spacing between the leading endpoint and the trailing endpoint of said at least one pair of endpoints in said lateral direction. By providing the ratio between the apply speed and the receiving speed and by providing the relative lateral movement between the apply member and the receiving member, the relative positioning of the pair of endpoints can be manipulated both in the transfer direction and the lateral direction. Hence, the trailing endpoint can be moved towards the leading endpoint of the respective pair across a path with vector components in both the transfer direction and the lateral direction. Effectively, the trailing endpoint may follow a curvature or be warped towards its respective leading endpoint with respect to the previously applied trailing endpoint. The correction of the ratio and the relative lateral movement can work particularly well when the leading endpoints and the trailing endpoints are distributed over the leading edge and the trailing edge, respectively, with the same interval, in accordance with one of the previously described embodiments.

In a preferred embodiment the tire component comprises a main part extending in a longitudinal direction between the leading end and the trailing end, wherein the first longitudinal edge forms a leading tip with the leading edge, wherein the ratio is adjusted during the transfer of the main part from the apply member onto the receiving member to splice the leading tip to the trailing edge. By ensuring that the leading tip is spliced to the trailing edge, the endpoints at or near said leading tip are substantially fixed, while the rest of the endpoints can still be manipulated. Hence, the initial ratio between the apply speed and the receiving speed can be calculated to make sure that at least these endpoints provide a good splice on the building drum.

In a further embodiment the ratio between the apply speed and the receiving speed is adjusted when the trailing endpoints are transferred from the apply member onto the receiving member. Hence, the relative positioning can be corrected when most of the tire component has already been applied to the receiving member. The part of the trailing edge that is not yet applied to the receiving member becomes increasingly smaller with the application of each subsequent trailing endpoint, thereby allowing for accurate control of the relative positioning in said part of the trailing edge that is not yet applied with respect to the part of the trailing edge that is already applied.

In a further embodiment the trailing endpoints are applied to the receiving member one by one, wherein directly after the application of one of the trailing endpoints to the receiving member the ratio between the apply speed and the receiving speed is adjusted for the next trailing endpoint that is to be applied to the receiving member. Again, as soon as the previous trailing endpoint has been applied the relative positioning between said previous trailing endpoint and the leading endpoint of the same pair of endpoints is substantially fixed on the receiving member and the next of the trailing endpoints that is not yet fixed can be accurately manipulated with respect to the previously applied trailing endpoint.

In a further embodiment the ratio between the apply speed and the receiving speed is adjusted by adjusting the receiving speed. By adjusting the receiving speed while keeping the apply speed constant, the tire component can be easily stretched or compressed. Moreover, it can be prevented that the adjustment of the ratio impacts any processes upstream of the apply conveyor, e.g. the transfer of the tire component from a supply conveyor onto the apply conveyor.

In a further embodiment the leading endpoints and the trailing endpoints are detected on the apply member. Hence, the relative positioning can be calculated prior to the transfer of the tire component from the apply conveyor onto the receiving member.

In a preferred embodiment the apply member is an apply conveyor. The tire component can be easily measured on the flat surface of the apply conveyor.

In an alternative embodiment the apply member is a transfer drum. The transfer drum can be used to transfer tire components such as chafers to the receiving member.

According to a second aspect, the invention provides an assembly for applying a tire component, in particular a breaker ply, from an apply member onto a building drum, wherein the tire component comprises a leading edge, a trailing edge and a first longitudinal edge and a second longitudinal edge extending between the leading edge and the trailing edge, wherein the leading edge is arranged to be spliced to the trailing edge on a tire building drum, wherein the assembly comprises the apply member, the receiving member, an apply member drive for driving the apply member in a transfer direction at an apply speed and a receiving member drive for driving the receiving member at a receiving speed, wherein the assembly further comprises an apply sensor for detecting a plurality of leading endpoints at the leading edge and for detecting, for each leading endpoint, a trailing endpoint at the trailing edge that together with the respective leading endpoint forms a pair of endpoints, wherein the assembly is provided with a control system for determining the relative positioning between the leading endpoint and the trailing endpoint for each pair of endpoints, wherein the control system is operationally connected to the apply member drive and the receiving member drive for adjusting the ratio between the apply speed and the receiving speed for each pair of endpoints during the transfer of the tire component from the apply member to the receiving member in the order in which said pairs of endpoints are spliced to improve the relative positioning of each pair of endpoints for splicing.

Preferably, the receiving member is the building drum, wherein the receiving member drive is a drum drive for rotating the building drum at the receiving speed.

The assembly according to the second aspect of the invention comprises a control system that is arranged for executing the steps as described in the aforementioned method. The assembly and its embodiments have the same technical advantages as the method and its respective embodiments. The technical advantages will therefore not be repeated hereafter.

In a preferred embodiment the control system is arranged for distributing the leading endpoints and the trailing endpoints over the leading edge and the trailing edge, respectively, with the same interval.

In a further preferred embodiment the tire component has a length between the leading endpoint and the trailing endpoint of each pair of endpoints on the apply member, wherein said length without adjustment of the ratio will either result in an overlapping splice, an open splice or a butt-splice on the building drum, wherein the control system is arranged for adjusting ratio such that:

the receiving speed is higher than the speed when transferring one of the pairs of endpoints which would result in an open splice; and

the receiving speed is lower than the speed when transferring one of the pairs of endpoints which would result in an overlapping splice.

In another embodiment the leading endpoint and the trailing endpoint of at least one of the pairs of endpoints are spaced apart on the apply member in a lateral direction transverse or perpendicular to the transfer direction, wherein the apply member and the receiving member are movable relative to each other in the lateral direction when transferring said at least one pair of endpoints to reduce the spacing between the leading endpoint and the trailing endpoint of said at least one pair of endpoints in said lateral direction.

In another embodiment the apply sensor is arranged at or above the apply member for detecting the leading endpoints and the trailing endpoints on the apply member.

Preferably, the apply member is an apply conveyor. Alternatively, the apply member is a transfer drum.

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

