Joining tire base layer

Abstract

A method of providing a joint between a first tire base layer end portion and a second tire base layer end portion, the method comprising: providing a first length of a tire base layer, the first length of the tire base layer comprising a first end portion, a first main portion, and a first pair of reinforcing elements; providing a tire base layer of a second length, the tire base layer of the second length comprising a second end portion, a second main portion, and a second pair of reinforcing elements; the first end portion and the second end portion are joined together such that each reinforcing element of the first pair of reinforcing elements is aligned with a corresponding reinforcing element of the second pair of reinforcing elements.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for providing a joint between a first tire base layer end portion and a second tire base layer end portion. The present invention also extends to methods and apparatus for manufacturing tires, which methods and apparatus incorporate methods and apparatus for providing a joint between a first tire base layer end portion and a second tire base layer end portion. Background Art

[0002] Tires (e.g., tires for vehicles, which can be any device for transporting people or goods) are typically manufactured using a batch process that requires manual labor during the intervening steps of the process as well as during multiple steps of the process itself. For example, bead wires are typically formed into rings for the tire in an initial step, which are placed by hand on rings of tire base material on a drum, and the bead wires are then secured within the tire base. A preformed rubber strip for forming the tread can then be placed on the tire base while being placed on the drum. The combined ring of tread and tire base is moved into an expansion mold where a curve is added to the flat surface of the ring. The partially formed tire can then be placed by hand into a separate curing mold to further shape the tire and form the tread pattern during the curing process.

[0003] Such batch processes are inefficient in terms of time and cost. It would therefore be beneficial to enable the tire manufacturing process to be more efficient. Summary of the invention

[0004] From a first aspect, the present invention provides a method for providing a joint between a first tire base layer end portion and a second tire base layer end portion, the method comprising: providing a first length of tire base layer, the first length of tire base layer including a first end portion, a first main portion and a first pair of reinforcing elements; providing a second length of tire base layer, the second length of tire base layer including a second end portion, a second main portion and a second pair of reinforcing elements; and joining the first end portion and the second end portion together so that each reinforcing element in the first pair of reinforcing elements is aligned with a corresponding reinforcing element in the second pair of reinforcing elements.

[0005] The tire base layer is a layer disposed under the tread of the tire and providing a frame for the tire. In a pneumatic tire with an inner tube or inner liner, the base layer covers the inner tube or inner liner to provide protection and constrain the inner tube or inner liner, thereby supporting resistance to internal pressure.

[0006] The tire base layer may include any suitable material for a base layer of a tire. For example, plastic or metal. Any such material may be provided in a grid form that may include through-surface holes, or in a continuous / sheet form (i.e., a continuous material) that does not include through-surface holes.

[0007] The tire base layer may include a fiber composite material and may then be referred to as a tire carcass.

[0008] A reinforcing element is any feature that provides a reinforcing effect to the tire base layer. Therefore, the reinforcing element contributes to the rigidity of the tire base layer and contributes to the ability of the tire base layer to maintain its shape and withstand internal pressure, while the main body of the tire base layer can be a flexible material, thereby increasing the toughness of the base layer and contributing to the tire gripping the surface when in use. The reinforcing element can be a modified portion of the tire base layer, so it is integral with the base layer. The reinforcing element can be formed by a material different from the material of the tire base layer and can be embedded in the tire base layer. For example, the reinforcing element can include a relatively rigid polymer, such as a polyamide with high tensile strength, and the main body of the tire base layer can include a relatively flexible polymer, such as a fiber-reinforced thermoplastic elastomer.

[0009] Thus, once the lengths of tire base layers are connected, the first pair of reinforcing elements and the second pair of reinforcing elements are aligned.The reinforcing elements may overlap in the joining area in the longitudinal and / or transverse direction of the connected tire base layers.

[0010] The first pair of reinforcement elements may include a first pair of bead wires and the second pair of reinforcement elements may include a second pair of bead wires.

[0011] The reinforcing element may be in the form of a bead wire. A bead wire is a length of material similar to a thread in that it extends substantially in one dimension. A bead wire is not necessarily limited to a metal wire. The bead wire may comprise a metal, a thermoplastic polymer or a thermosetting polymer. The bead wire may comprise a suitable aramid material.

[0012] The first length of tire base ply can be contiguous with the second length of tire base ply such that the first end portion and the second end portion are opposing longitudinal ends of a single tire base ply.

[0013] A complete circular tire base ply may be formed from a single length of tire base ply such that one longitudinal end is joined to the other longitudinal end.

[0014] Alternatively, a plurality of tire base layers may be joined at respective longitudinal ends to form a ring.

[0015] The method may include joining the first end portion to the second end portion via a sleeve, a seam, welding, solder, and / or glue.

[0016] The sleeve of additional material may be disposed around the joint between the first end portion and the second end portion and may be sufficiently tight and / or include an adhesive sufficient to form the joint. The sleeve may be applied over a joint that may have been formed by welding, solder and / or glue.

[0017] Joining the first end portion and the second end portion together may include: forming a contact area between the first end portion and the second end portion of the tire base layer; and performing a welding operation to join the first end portion and the second end portion in the contact area.

[0018] Therefore, the end portion of the tire base layer is attached where contact is made between the above-mentioned two lengths of the tire base layer.

[0019] The welding operation may include one or more of: heated tool welding, hot gas welding, ultrasonic welding, spin welding, infrared welding, high frequency welding, vibration welding, induction welding, microwave welding, resistance welding, extrusion welding, and laser welding.

[0020] The welding operation may include raising the temperature of a contact area between the first end portion and the second end portion and applying pressure for a sufficient time to adequately bond the first end portion and the second end portion in the contact area.

[0021] Heat may be applied from an external heat source, and / or heat may be generated by mechanical movement, and / or heat may be generated using electromagnetism.

[0022] The welding operation may include vibrating the contact area between the first end portion and the second end portion and applying pressure for a sufficient time to sufficiently bond the first end portion and the second end portion in the contact area. Thus, the welding operation may employ friction welding techniques.

[0023] Joining the first length of tire base layer and the second length of tire base layer together may include: forming a contact area between the first end portion and the second end portion of the tire base layer; and the method may include: providing glue in the contact area, and applying pressure to the contact area.

[0024] Therefore, the end portion of the tire base layer is attached where contact is made between the above-mentioned two lengths of the tire base layer.

[0025] Forming a contact area between the first end portion and the second end portion of the tire base layer may include placing the first end portion over the second end portion.

[0026] Thus, the first end portion of the tire base layer overlaps the second end portion of the tire base layer. Thus, there is twice the thickness of the tire base layer throughout the thickness direction in the contact area. Thus, if a tire is formed using the joined tire base layers, there is additional thickness in the radial direction of the tire in the contact area. The additional strength due to the increased thickness helps to minimize any strength reduction caused by the joint. Welding and / or gluing may be performed in the overlapping area.

[0027] In this case, the first pair of reinforcing elements and the second pair of reinforcing elements may be aligned such that the first pair and the second pair of reinforcing elements overlap throughout the thickness direction.

[0028] The contact area may be appropriately sized to provide sufficient strength to the joint and / or to produce a desired length of combined tire base layer.

[0029] The first end portion may be a first longitudinal surface of a first length of the tire base layer, and the second end portion is a second longitudinal surface of a second length of the tire base layer; and forming a contact area between the first end portion and the second end portion may include abutting the first end portion with the second end portion.

[0030] By abutting the longitudinal end faces, there is no overlap of material through the thickness.The end faces of the first pair of reinforcing elements may abut the end faces of the second pair of reinforcing elements.

[0031] The first and second longitudinal ends of the length of tire base layer may have complementary shapes such that when the first and second end portions of the length of tire base layer are abutted, a continuous tire base layer having parallel sides is created.

[0032] Thus, the longitudinal ends of the first length of tire base layer can fit into the adjacent faces of the second length of tire base layer. A smooth transition from the first length of tire base layer to the second length of tire base layer is thus formed, and the visibility of the joint is reduced. The contact area between the end faces is also maximized by having corresponding shapes that allow continuous contact between these faces.

[0033] The first longitudinal end and the second longitudinal end may be: formed into a single length, which is perpendicular to the length of the tire base layer; formed into multiple lengths, each length is perpendicular to the length of the tire base layer; formed into a length that is not perpendicular to the length of the tire base layer; or formed into a curved surface or multiple curved surfaces.

[0034] Thus, the two ends may be formed as straight lines along the transverse direction of the tire base layer. The two ends may be formed as straight diagonal lines along a direction that is angled with the transverse direction of the tire base layer. One end may have a step or cut shape that may include a portion that protrudes more than another portion, and the other end may have an opposite step or cut shape that may include a portion that receives the protruding portion of the first end. One end may include a concave curved surface, and the other end may include an inverse convex curved surface.

[0035] The reinforcing elements may extend in the longitudinal direction from first and / or second end portions of the respective first and second lengths of the tire base layer such that they abut and / or overlap when the contact area is formed.

[0036] The respective reinforcing elements may be connected without interfering with or overlapping the tire base layer material.

[0037] Joining the first end portion and the second end portion together may include positioning an insert between a longitudinal face of the first length of the tire base layer and a longitudinal face of the second length of the tire base layer.

[0038] The insert thus separates at least a portion of the first end face from the second end face. The insert may be an adhesive to facilitate joining. The first and second longitudinal ends may be complementary in shape so as to fit against each other as described above, or the first and second longitudinal ends may have non-complementary shapes and the insert may be shaped so as to ensure that the ends are joined so as to produce a continuous tire base layer with parallel sides.

[0039] The insert may include a head portion extending at least partially over the first end portion and the second end portion.

[0040] Thus, the insert is disposed between the end faces and above and / or below at least some portion of the tire base layer. The additional contact area between the insert and the tire base layer provided by the head portion increases the strength of the joint. The head portion of the insert may extend over a major portion of the first length of tire base layer and / or the second length of tire base layer.

[0041] The reinforcing elements may extend in the longitudinal direction from the first end portion and / or the second end portion of the corresponding first length of the tire base layer and the corresponding second length of the tire base layer, so that when the insert is arranged between the longitudinal surface of the first length of the tire base layer and the longitudinal surface of the second length of the tire base layer, these reinforcing elements are adjacent and / or overlapping.

[0042] Thus, the reinforcing element may extend through the insert. Thus, the connection of the reinforcing element may take place in order to improve the conduction of stresses along the tire base layer.

[0043] The reinforcement elements of the first pair of reinforcement elements can be joined to corresponding reinforcement elements of the second pair of reinforcement elements via sleeves, seams, welding, solder or glue.

[0044] The joint between the reinforcing elements may be located between the ends of the reinforcing elements that overlap in the longitudinal direction, or may be located between the sides of the end portions of the reinforcing elements that overlap in the transverse direction or through the thickness direction. At least one of the pairs of reinforcing elements may extend beyond a corresponding length of the base layer material of the tire base layer so as to overlap the corresponding reinforcing element in the other pair. Where a seam is used to join the reinforcing elements, the seam may be formed using equipment such as a bar tack machine or an automatic rope sewing machine.

[0045] The reinforcing elements may be composed of metal, and the reinforcing elements may be joined via spot welding.The reinforcing elements may be composed of thermoplastic material, and the reinforcing elements may be joined by heat treatment.

[0046] The joint between the first pair of reinforcing elements and the second pair of reinforcing elements allows for the conduction of stresses through the connected pairs.

[0047] A sleeve of additional material may be provided around the joint of the reinforcing element.The sleeve may be applied over a joint that may have been formed by welding, solder and / or glue.

[0048] The method may include bonding a liner material to the first length of the tire base ply and the second length of the tire base ply so as to overlap a junction between the first end portion and the second end portion.

[0049] The lining material thus supports the joint. The lining material need not extend around all edges of the tire base layer, but may cover a portion of the joint. Optionally, the lining material may be bonded to the first length of the tire base layer and the second length of the tire base layer via glue or adhesive. The lining may extend 0.5 cm or more along the longitudinal length of the tire base layer. The lining may extend from one longitudinal face of the tire base layer to an opposite longitudinal face of the tire base layer.

[0050] The liner material and the first length of tire base layer and the second length of tire base layer may include fibers, and wherein the liner material is bonded to the first length of tire base layer and the second length of tire base layer so that the fibers of the liner material are aligned with the fibers of the first length of tire base layer and the second length of tire base layer.

[0051] Optionally, the fibers of the liner material may be aligned with the fibers of the first length of the tire base layer and the second length of the tire base layer within an angle range of 15 degrees or less. The first length of the tire base layer and the second length of the tire base layer may each include a first group of fibers and a second group of fibers arranged at two different angles relative to the longitudinal length of the tire base layer, the liner material may include two groups of fibers oriented in a manner corresponding to those fibers of the first length of the tire base layer and the second length of the tire base layer, and the liner material may be bonded to the first length of the tire base layer and the second length of the tire base layer so that each of the first group of fibers and the second group of fibers of the liner material is aligned with the first group of fibers and the second group of fibers of the above-mentioned length of the tire base layer. The high tensile strength of the fibers helps to resist tensile stresses, and the alignment of the fibers of the liner and the tire base layer allows stress to be transmitted along the high tensile strength fibers.

[0052] The liner material may include fibers such that once bonded to the first length of tire base layer and the second length of tire base layer, the liner material includes fibers that are aligned with the longitudinal length of the tire base layer.

[0053] Thus, the liner material includes fibers that are aligned with the direction of the reinforcing elements so as to facilitate the transfer of forces between the reinforcing elements of the first length of tire base ply and the second length of tire base ply.

[0054] A lining material may be provided on lower surfaces of the first and second main portions.

[0055] That is, when the joined tire base layer is formed into a cylindrical shape for use in a tire, the liner is disposed radially inward of the tire base layer. Therefore, the height difference caused by the liner does not affect the tread of the tire.

[0056] The lining material may extend continuously from the lower surfaces of the first and second main portions, over the longitudinal edges of the length of substrate layer, and to the upper surfaces of the first and second lengths of substrate layer.

[0057] Therefore, when the joined tire base layer is formed into a cylindrical tire having a hyperbolic shape for use in a tire, the liner is arranged on the radially inward surface of the tire base layer relative to the radius r in the transverse cross-section, and extends to the radially outward side of the tire base layer at a first length and a second length relative to the radius r in the circumferential plane of the tire.

[0058] Prior to joining the first and second end portions, a lining material is placed in position over the joint.

[0059] Thus, in a related embodiment, the lining is present when the welding operation is performed. Thus, in a related embodiment, the lining material is present when the temperature of the contact area between the first end portion and the second end portion is increased and pressure is applied, and / or the lining material is present when the contact area between the first end portion and the second end portion is vibrated and pressure is applied.

[0060] The method may comprise performing the method according to the first aspect of any one of the above descriptions a sufficient number of times to form a circular ring of the tyre base layer.

[0061] In some cases, the first length of tire base layer and the second length of tire base layer are continuous, i.e., belong to a single tire base layer strip, and the method of joining the first end portion and the second end portion only needs to be performed once in order to form a complete circle of tire base layer for the tire. In other cases, the first length of tire base layer and the second length of tire base layer are separate, so further joining involving additional end faces is required to form a complete ring for the tire. Therefore, a plurality of sizes of the first length of tire base layer and the second length of tire base layer can be used to provide a base layer for a tire having a desired circumference.

[0062] The first length of tire base layer and the second length of tire base layer may include a hyperboloid tire shape having a radius r in a transverse cross-section and a radius of curvature R in a cross-section perpendicular to the transverse cross-section.

[0063] During the joining operation, the tire base layer may thus include a shape corresponding to the shape it will take when used in a tire. Alternatively, the tire base layer may be joined while flat and subsequently modified to have a hyperboloid tire shape. The shape of each of the first length of tire base layer and the second length of tire base layer may include a segment of a cylindrical tire.

[0064] The method may include applying heat to the tire base layer and stretching the tire base layer over the surface of the wheel so that the tire base layer adopts a hyperboloid tire shape.

[0065] The heat allows the tire base layer to become ductile so that it is plastically deformed when the tire base layer is stretched on the wheel. The tire base layer is allowed to cool so that the tire base layer retains the curvature adopted when the tire base layer is stretched on the wheel.

[0066] Stretching the tire base ply on the wheel may be done in a continuous process such that a continuous strip of the tire base ply may be fed on and removed from the wheel without cutting the tire base ply.

[0067] Shaping the tire base layer may reduce the complexity and / or increase the efficiency of further processes for forming a tire having the tire base layer.

[0068] Providing a hyperbolic shape to each of a first length of tire base layer and a second length of tire base layer may include providing a certain length of tire base layer with a basically flat shape, wherein the basically flat shape includes at least one depression and at least one ridge, wherein each depression and ridge extends and is inclined in both a lateral direction and a longitudinal direction of the tire base layer.

[0069] Due to the compact form, the substantially flat shape allows easier processing, for example enabling successive processing steps.The method may comprise inverting the recess to produce a hyperboloidal shape having a radius r in the transverse direction and a radius R in the longitudinal direction.

[0070] The length of tire base layer including a hyperboloid tire shape can be manufactured by: providing a certain length of tire base layer; inserting the length of tire base layer into the cavity of a base layer mold; and applying heat and pressure; wherein: the base layer mold is a basically flat mold including a shell, the shell including at least one longitudinal inner cavity extending between at least two opposite main walls and two opposite edge walls, wherein: each of the main walls has at least one ridge and at least one depression; each ridge and each depression extends and is inclined in both the transverse direction and the longitudinal direction of the cavity; the ridges and depressions are arranged alternately along the length of the mold; and the ridges of one main wall are opposite to the depressions of another main wall.

[0071] The heat and pressure cause the tire base layer to adopt the shape of the substantially flat mold.

[0072] The length of tire base layer including a hyperboloid tire shape can be manufactured by: providing a certain length of tire base layer; inserting the length of tire base layer into the cavity of a base layer mold; and applying heat and pressure; wherein: the shape of each of the first length of tire base layer and the second length of tire base layer includes a segment of a cylindrical tire.

[0073] The shape of the cavity of the tire base layer mold may correspond to a segment of a circle. The segment may be a 45 degree segment or less, a 45 degree segment or more, a 90 degree segment or more, a 180 degree segment (i.e., a semicircle) or more, or a 270 degree segment or more.

[0074] The shape of the cavity of the tire base layer mold may include multiple segments of a cylindrical tire. The arc of each of the multiple segments may extend along the longitudinal length of the cavity, and the midpoints of at least a pair of adjacent segments may extend in the same transverse direction relative to the longitudinal length of the cavity, thereby forming a convex pattern.

[0075] Additionally or alternatively, the arc of each of the plurality of segments may extend along the longitudinal length of the cavity, and the midpoints of at least a pair of adjacent segments extend in opposite transverse directions relative to the longitudinal length of the cavity, thereby forming a sine wave pattern. Thus, by flattening the mold in terms of the curved surface having a radius R in a cross section perpendicular to the longitudinal direction of the cylindrical tire, the mold is reduced in size and complexity.

[0076] The first length of tire base layer and / or the second length of tire base layer may include a tread.

[0077] The tread on the first length of the tire base layer can be joined to the tread on the second length of the tire base layer, which can be achieved using a joining process that joins the tire base layers. Alternatively, additional steps may be required to join the treads.

[0078] The tread may be an overmoulded tread, ie the tread may have been provided on the first length of tyre base layer and the second length of tyre base layer via injection moulding before the joining step is performed.

[0079] The tread may be an overmolded tread and may be provided by inserting a length of tire base layer into a tread mold; injecting an elastomeric material into the tread mold; allowing the elastomeric material to solidify so that the elastomeric material and the tire base layer adopt the shape of the tread mold; and removing the combined tire base layer and elastomeric material from the tread mold.

[0080] The tread mold can be a basically flat tread mold including a shell, which includes at least one longitudinal inner cavity extending between at least two opposite main walls and two opposite edge walls, wherein: each of the main walls has at least one ridge and at least one recess; each ridge and each recess extends and is inclined in both the transverse direction and the longitudinal direction of the cavity; the ridges and recesses are arranged alternately along the length of the tread mold; and the ridges of one main wall are opposite to the recesses of another main wall.

[0081] The joining process may be performed while the tire base layer and the overmolded tread are substantially flat shapes. Alternatively, the method may include providing the overmolded tread on the tire base layer using a substantially flat tread mold as described above, and inverting the depression to produce a hyperboloid shape having a radius r in the lateral direction and a radius R in the longitudinal direction before joining the first length of the tire base layer and the second length of the tire base layer.

[0082] The first length of tire base layer and / or the second length of tire base layer may be provided with a hyperboloid shape, wherein the size of the depressions and ridges of the tire base layer is greater than the size of the depressions and ridges of the tread mold.

[0083] Thus, when a substantially flat tire base layer and a substantially flat tread mold are used, the dimensions between the molds are different such that the dimensions of the formed tire base layer are larger than the equivalent dimensions of the formed tread. Due to the difference in thermal expansion of the material of the tire base layer and the thermal expansion of the tread material, after the tread is deposited onto the base layer and subsequently cooled, the curvatures of the base layer and tread will be aligned. Thus, the difference in thermal expansion of the different materials is accounted for.

[0084] The shape of the cavity of the tread mold may include at least one section of a cylindrical tire.

[0085] The shape of the cavity of the tread mold may correspond to a segment of a circle. The segment may be a 45 degree segment or less, a 45 degree segment or more, a 90 degree segment or more, a 180 degree segment (i.e., a semicircle) or more, or a 270 degree segment or more.

[0086] The shape of the cavity of the tread mold may include multiple segments of a cylindrical tire. The arc of each of the multiple segments may extend along the longitudinal length of the cavity of the tread mold, and the midpoints of at least a pair of adjacent segments may extend in the same transverse direction relative to the longitudinal length of the cavity, thereby forming a convex pattern. Additionally or alternatively, the arc of each of the multiple segments may extend along the longitudinal length of the cavity of the tread mold, and the midpoints of at least a pair of adjacent segments extend in opposite transverse directions relative to the longitudinal length of the cavity, thereby forming a sine wave pattern. By flattening the mold in terms of a curved surface having a radius R in a cross section perpendicular to the longitudinal direction of the cylindrical tire, the tread mold is reduced in size and reduces the complexity of the tread mold.

[0087] The first length of tire base layer and the second length of tire base layer may be provided with a hyperboloid tire shape and may adopt a radius of curvature greater than a radius of curvature of the cavity of the tread mold.

[0088] Thus, the radius of curvature of the first length of the tire base layer and the second length of the tire base layer is greater than the radius of curvature of the at least one section of the tread mold. That is, the lateral extent and longitudinal extent of the at least one section of the tire base layer are greater than the lateral extent and longitudinal extent of the at least one section of the tread mold. Thus, the at least one section of the tire base layer has a larger size than the at least one section of the tread mold into which it is inserted.

[0089] The first end portion, the first main portion, and the second main portion may include a tread, and the second end portion does not include a tread, and the joining of the first end portion and the second end portion may include joining the tread of the first end portion to the tread of the second main portion and / or joining the tread of the first end portion to the tire base layer of the second end portion.

[0090] The base layer of the second end portion may overlap the first end portion such that the tread of the second main portion is adjacent or abutting the tread of the first end portion. The tread may be joined by overmolding additional elastomeric material onto the exposed tire base layer of the first end portion. Alternatively, the tread may be joined by any of the joining processes discussed above with respect to joining of the tire base layer.

[0091] The tread of the first end portion may extend beyond the tire base layer of the first end portion in the longitudinal direction of the tire base layer.

[0092] The tread extending beyond the tire base layer of the first end portion may be joined to the base layer of the second end portion. The tread may extend beyond the tire base layer by 1 cm or more. The tread may extend beyond the tire base layer by up to 5 cm. When an insert is used, the tread of the first end portion may extend beyond the insert. The insert and / or the tread extending beyond the base layer of the first end portion may have a length that enables the tread of the first end portion and the second end portion to be joined and the tire base layer of the first end portion and the second end portion to be joined.

[0093] The first main portion and the second main portion may include a tread, and the first end portion and the second end portion may not include a tread, and the joining of the first end portion and the second end portion may include: at least partially overlapping the first end portion with the second end portion, and applying material between the first main portion and the second main portion to cover the first end portion and the second end portion.

[0094] The material applied between the first main portion and the second main portion can be applied by overmolding the elastomeric material onto the exposed tire base layer. The material applied between the first main portion and the second main portion can penetrate the tire base layer so that the elastomeric material extends from one face of the tire base layer of the first end portion and the second end portion to the opposing face of the first tire end portion and the second tire end portion. Particularly good penetration occurs when the tire base layer is composed of a mesh and / or a fabric.

[0095] A first length of tire base layer and a second length of tire base layer can each be provided by providing a sheet of material having a first lateral edge portion and a second lateral edge portion, wherein the first lateral edge portion and the second lateral edge portion are separated by a center portion, placing a first reinforcing element on the sheet at the intersection of the first lateral edge portion and the center portion, and placing a second bead wire on the sheet at the intersection of the center portion and the second lateral edge portion, folding the first lateral edge portion over the first reinforcing element, folding the second lateral edge portion over the second reinforcing element, and securing the first lateral edge portion and the second lateral edge portion to the center portion.

[0096] The method enables the formation of a base layer including reinforcing elements in a continuous process. The base layer including reinforcing elements can be formed as a flat piece which need not be provided with a length commensurate with the circumference of the tire. As an alternative to using the above method, a base layer of longer length can be produced, i.e. a base layer having a length that is many times the circumference of the tire, which base layer can be cut to size as required.

[0097] Providing a continuous strip of base layer allows the base layer to be incorporated into a continuous process for forming a tire.

[0098] The first length of base layer and / or the second length of base layer may be provided in the form of a continuous tire base layer strip.

[0099] Thus, the joining of the two substrate layer end portions can be incorporated into a continuous manufacturing process.

[0100] Viewed from another aspect, the present invention provides a tire manufactured according to the method for manufacturing a tire base layer and overmolding a tread as described above.

[0101] The tire can be applied to any transport device including wheels. The tire can be applied to bicycles or tricycles, motor vehicles (such as motorcycles, scooters and trucks) or baby carriages, etc.

[0102] Viewed from another aspect, the present invention provides an apparatus for joining a first length of a tire base layer and a second length of a tire base layer, the apparatus comprising a clamp for positioning a first end portion of the first length of the tire base layer and a second end portion of the second length of the tire base layer, and for performing a welding operation to join the first end portion and the second end portion.

[0103] Thus, in a related embodiment, the means for joining the first length of tire base layer and the second length of tire base layer is configured to apply pressure and one or more of heat and vibration to the first end portion and the second end portion. The heat may be applied from an external heat source, and / or the heat may be generated by mechanical movement, and / or the heat may be generated using electromagnetism.

[0104] The apparatus may include means for cutting the continuous tire base layer strip into desired lengths to obtain a first length of tire base layer and / or a second length of tire base layer.

[0105] The apparatus may include an overmolding station including means for simultaneously positioning a first end portion and a second end portion of a tire base layer in an at least partially overlapping configuration and for injecting an elastomeric material between the first main portion and the second main portion of the tire base layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] Certain embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:

[0107] Figure 1 Sheets of tire base material and reinforcing elements are shown, which may exceed the dimensions indicated in the figures in length.

[0108] Figure 2a A tire base layer including reinforcing elements is shown.

[0109] Figure 2b A tire base layer including reinforcing elements is shown.

[0110] Figure 3a An apparatus for forming a tire base layer including reinforcing elements is shown.

[0111] Figure 3b An apparatus for providing an assembly for forming a tire base layer including reinforcing elements is shown.

[0112] Figure 3c A reel on which a continuous strip of tire base layer including reinforcing elements is wound is shown.

[0113] Figure 4 Sheets of tire base material and reinforcing elements are shown, which may exceed the dimensions indicated in the figures in length.

[0114] Figure 5 A tire base layer including reinforcing elements is shown.

[0115] Figure 6a A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements is shown.

[0116] Figure 6b A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements is shown.

[0117] Figure 7a A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements and a puncture protection layer is shown.

[0118] Figure 7b A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements and a puncture protection layer is shown.

[0119] Figure 7c A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements and a puncture protection layer is shown.

[0120] Figure 8 An apparatus for providing a puncture protection layer for forming a continuous strip of a tyre base layer comprising reinforcing elements and a puncture protection layer is shown.

[0121] Fig. 9 Tubular materials and reinforcing elements are shown for forming a tire base layer and may extend in length beyond the dimensions indicated in the figures.

[0122] Fig.10 A tire base layer comprising a reinforcing element comprising a tubular material is shown, the tire base layer comprising the reinforcing element may exceed in length the dimensions indicated in the figure.

[0123] Fig.11 A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements is shown.

[0124] Fig.12a A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements and a puncture protection layer is shown.

[0125] Figure 12b shows a cross section through the longitudinal length of a continuous strip of tyre base layer comprising reinforcing elements and a puncture protection layer.

[0126] Fig.12c A cross section through the longitudinal length of a continuous strip of tire base layer including reinforcing elements and a puncture protection layer is shown.

[0127] Fig.13 A segmented tire base layer including reinforcing elements shaped into a hyperbolic tire shape is shown.

[0128] Fig.14 An apparatus for shaping a tire base layer and reinforcing elements is shown.

[0129] Fig.15 A segmented mold for molding the tire base layer and reinforcing elements is shown.

[0130] Fig.16 Shows the use of Fig.15 The segmented mold forms the tire base and the reinforcing element segments.

[0131] Fig.17 A segmented mold for molding the tire base layer and reinforcing elements is shown.

[0132] Fig.18 A cross section through a longitudinally extending centerline of a substantially flat mold for molding a tire base layer including reinforcing elements is shown.

[0133] Fig.19 The lower half of a substantially flat mold for shaping a tire base layer including reinforcing elements is shown.

[0134] Fig. 20 A profile view of a substantially flat shape is shown.

[0135] Fig.21 A tire base layer including reinforcing elements is shown comprising a substantially flat shape.

[0136] Fig. 22 A tire base layer including reinforcing elements and an overmolded tread is shown.

[0137] Fig.23 An apparatus for manufacturing a continuous strip of tire base layer comprising reinforcing elements and an overmolded tread is shown.

[0138] Fig.24 A cross section through a longitudinally extending centerline of a substantially flat mold for overmolding a tread to a tire base layer including reinforcing elements is shown.

[0139] Fig.25 A tire base layer including reinforcing elements is shown, the tire base layer including an overmolded tread and including a substantially flat shape.

[0140] Fig.26 A segmented mold for overmolding a tread to a tire base layer including reinforcing elements is shown.

[0141] Fig. 27 A tire base layer including reinforcing elements is shown, the tire base layer including an overmolded tread including a hyperbolic tire shape, and using Fig.26 The mold is formed.

[0142] Fig.28 A segmented mold for overmolding a tread to a tire base layer including reinforcing elements is shown.

[0143] Fig.29A tire base layer including reinforcing elements is shown, the tire base layer including an overmolded tread including a hyperbolic tire shape, and using Fig.28 The mold is formed.

[0144] Fig.30 A substantially flat tread mold and a preformed tire base layer including reinforcing elements are shown.

[0145] Fig.31 Two sections of a tire base layer including reinforcing elements are shown.

[0146] Fig.32 Two sections of a tire base layer are shown including reinforcing elements each including a hyperbolic shape.

[0147] Fig.33 A complete ring of tire base layer is shown formed by joining the ends of a single strip of tire base layer including reinforcing elements.

[0148] Fig.34 A complete ring of tire base layer is shown comprising a plurality of strips of tire base layer joined to the reinforcing elements.

[0149] Fig.35 The contact area between two sections of tire base layer is shown.

[0150] Fig.36 The contact area between two sections of tire base layer is shown.

[0151] Fig.37 The ends of two sections of tire base layer are shown.

[0152] Fig.38 Shows Fig.37 The contact area between two lengths of tire base layer is shown along with an indication of a piece of overmolding material to be added to the partially overlapping ends.

[0153] Figures 39a to 39d A plan view showing the configuration of the ends of the segments of tire base layer.

[0154] Figures 40a to 40c A transverse view of two sections of a tire base layer joined using an insert is shown.

[0155] Fig.41a A transverse view of two sections of a tire base layer joined using an insert is shown, shown in expanded form.

[0156] Fig.41b and Fig.41c Shown is a plan view of two sections of tire base layer joined using an insert.

[0157] Fig.42a A transverse view of two sections of flat tire base layer joined and including cushioning material is shown.

[0158] Figure 42b Two sections of a tire base layer comprising a hyperbolic shape, joined and including cushioning material are shown.

[0159] Fig.42c Shows Figure 42b Expanded view of .

[0160] Fig.43 Two lengths of tire base layer (comprising fibers) and cushion material (comprising fibers) are shown to be joined.

[0161] Fig.44a Two sections of a tire base layer are shown, including reinforcing elements and tread to be joined.

[0162] Figure 44b Two sections of a tire base layer are shown, including reinforcing elements and tread to be joined.

[0163] Fig.45 An apparatus for joining a first length of a tire base layer including reinforcing elements to a second length of a tire base layer is shown. DETAILED DESCRIPTION

[0164] like Figure 1 As shown, a pair of bead wires 12 are positioned on the base material sheet 10 and are each aligned with the longitudinal length of the sheet 10. The sheet 10 thus comprises a first lateral edge portion 14, a central portion 16 and a second lateral edge portion 18 defined by the bead wires 12.

[0165] Figure 2a It is shown that a sheet of tire base material is formed into a tire base layer including a reinforcing element by folding a first lateral edge portion 14 over a first bead wire 12a and folding a second lateral edge portion 18 over a second bead wire 12b. The first lateral edge portion 14 overlaps with the second lateral edge portion 18 to form an overlapping region 22. The first lateral edge portion 14 and the second lateral edge portion 18 may be fixed to the central portion 16. In the overlapping region 22, the first lateral edge portion 14 and the second lateral edge portion 18 may also be fixed to each other. Since a pair of bead wires 12 are positioned parallel to each other, the first longitudinal side 24 and the second longitudinal side 28 of the tire base layer including the reinforcing element 20 are also parallel to each other. The first lateral edge portion 14 and the second lateral edge portion 18 do not need to overlap to form the overlapping region 22; Figure 2b An example in which the first lateral edge portion 14 and the second lateral edge portion 18 are fixed only to the central portion is illustrated.

[0166] Figure 3a The process of folding the base material sheet 10 by the folding device 30 is shown. Figure 1 2 are provided in the Figure 3a . The base material sheet 20 is fed into the folding device 30 from the first end 32 and moves along the folding device 30 in the direction A. The first folding device 31 comprises a first folding guide 34. The first folding guide 34 causes the first lateral edge portion 14 to be bent or folded around the first bead wire 12a and guides the first lateral edge portion 14 into a position adjacent to or in contact with the center portion 16. Further along the folding device 30, in the direction A, a second folding device 33 is provided. The second folding device 33 comprises a second folding guide 38, which causes the second lateral edge portion 18 to be bent or folded around the second bead wire 12b and guides the second lateral edge portion 18 into a position adjacent to or in contact with the center portion 16 and / or a position adjacent to or in contact with the first lateral edge portion 14 in the overlap region 22.

[0167] When the base material sheet 20 is fed through the folding device 30, a tire base layer including the reinforcing element 20 can be continuously produced. In this way, a continuous strip of tire base layer can be formed. This means that a tire base layer including reinforcing elements 20 sufficient for use can be formed into multiple tires without manual intervention. The tire base layer including the reinforcing element 20 leaving the second folding device 33 can be wound onto a reel for storage.

[0168] The first folding device 31 further comprises a fixing member, not shown, to fix the first transverse edge portion 14 to the central portion 16. Likewise, the second folding device 33 comprises a fixing member, not shown, to fix the second transverse edge portion 18 to the central portion 16 and / or the first transverse edge portion 14. For example, the fixing member of the first folding device 31 and / or the second folding device 33 may comprise a heat gun.

[0169] Figure 3b A base material reel 35, a first bead wire reel 36a and a second bead wire reel 36b are shown. The base material sheet 10 is fed directly from the base material reel 35 to an assembly unit comprising a folding device 30. Likewise, the first bead wire 12a and the second bead wire 12b are fed directly from the first bead wire reel 36a and the second bead wire reel 36b, respectively, to the folding device 30. Fixing means, not shown, may be used to fix the bead wires 12a, 12b in position on the base material sheet before the folding operation begins.

[0170] Figure 3cAn assembled tire base layer is shown, which includes reinforcing elements 20, 61 wound onto a reel 38 for storage. The tire base layer including the reinforcing element 20 can be wound onto the reel 38 directly from the folding device 30, or wound onto the reel 38 after additional manufacturing steps (such as applying overmolding described below). The tire base layer including the reinforcing element 61 formed using tubular material (as described below) can also be wound onto the reel 38 directly after assembly or after additional manufacturing steps.

[0171] The continuous strip of tire base layer including reinforcing elements 20 can be pulled from the reel and cut into lengths that require further processing for use in a tire. The continuous strip of tire base layer including reinforcing elements 20 can be pulled directly from the reel into another device to process the continuous strip of tire base layer including reinforcing elements 20 for use in a tire. In this way, processing can remain continuous.

[0172] Instead, the continuous strip of tire base layer including reinforcing elements 20 can be fed directly from the folding device 30 to another device for processing the continuous strip of tire base layer including reinforcing elements 20 for use in tires. Similarly, in this way, processing can be maintained continuously.

[0173] Figure 4 A sheet of material 10 is shown that includes a fiber structure. The fibers of the fiber structure may be formed of nylon, cotton, polyester, or aramid. The fiber structure includes a unidirectional fiber group 40 (diagonal hatching indicates the presence and direction of a first fiber group), wherein each fiber in the fiber group 40 extends in a direction generally parallel to the other fibers in the fiber group 40. The unidirectional fiber group 40 is supported by a support fiber group, not shown, that is woven through the unidirectional fiber group 40 to secure the fibers relative to each other.

[0174] The sheet of material 10 is cut so that the direction of the unidirectional fiber groups 40 is offset by an angle α from the longitudinal direction of the sheet.

[0175] Figure 5 A tire base layer is shown which includes a reinforcing element 20 when the first lateral edge portion 14 is folded over the first bead wire 12a and the second lateral edge portion 16 is folded over the second bead wire 12b. As illustrated by the hatching, the direction of the unidirectional fiber group 40 in the center portion 16 will be different from the direction of the unidirectional fiber group in the first lateral edge portion and the second lateral edge portion. In other words, the base material provided between a pair of bead wires 12 in the tire base layer including the reinforcing element 20 will include fibers with different directions.

[0176] Figure 6aA cross section taken perpendicular to the longitudinal length of the tire base layer is shown, including the reinforcing element 20. The first lateral edge portion 14 is folded around the first bead wire 12a and fixed to the central portion 16. The second lateral edge portion is folded around the second bead wire 12b and fixed to the central portion 16 and to the first lateral portion 14 in the overlap region 22.

[0177] Figure 6b Shown with Figure 6a A similar cross section is shown in which the first lateral end 14 and the second lateral end 18 do not form an overlapping region 22 .

[0178] Figures 7a to 7c Similarly shown is a cross section of the tire base layer including the reinforcing elements 20 taken perpendicularly to its longitudinal extent. Figures 7a to 7c Each of the figures shows a puncture protection layer 50. In each case, the puncture protection layer 50 is provided at a middle portion 52 of the tire base layer including the reinforcing element 20. When the tire base layer is used in a tire, the middle portion 52 of the tire base layer including the reinforcing element 20 will coincide with the tread of the tire, and the first side portion 54 and the second side portion 58 of the tire base layer including the reinforcing element 20 will coincide with the sidewall of the tire. The middle portion 52 will be located adjacent to the ground contact area of ​​the tire. The puncture protection layer 50 is therefore located to at least coincide with the tread of the tire to provide the most useful protection.

[0179] Figure 7a The puncture protection layer 50 provided on the outer surface of the first lateral portion 14 and / or the second lateral portion 18 is illustrated.

[0180] Figure 7b A puncture protection layer 50 provided between the central portion 16 and the first lateral portion 14 and / or the second lateral portion 18 is illustrated.

[0181] Figure 7c A puncture protection layer 50 provided on the outer surface of the central portion 16 is illustrated.

[0182] The first transverse end 14 and the second transverse end 18 do not form a Figure 6b As shown in the example of the overlapping area 22, the puncture protection layer 50 can be Figures 7a to 7c are provided in the corresponding positions shown.

[0183] Figure 8 The folding device 30 is shown being provided to the puncture protection layer 50. In this example, the puncture protection layer may be bonded between overlapping portions of the sheet of base material, or secured to the sheet 10 using the steps described herein.

[0184] Fig. 9A tubular material 60 for manufacturing a continuous strip of a tire base layer is shown. The tubular material 60 extends in a longitudinal direction, and during the manufacture of the continuous strip of the tire base layer, a first reinforcing element 12a and a second reinforcing element 12b are inserted into the tubular material 60 to extend in the same longitudinal direction. The first reinforcing element 12a and the second reinforcing element 12b thus extend parallel to the longitudinal length of the tubular material 60. Tubular means that the material provides a cylinder including a hollow center, and thus the reinforcing elements 12a, 12b are inserted into the hollow center. The tubular configuration of the tubular material can be formed while the reinforcing element is inserted into the center of the tubular material (such as by fixing the first longitudinally extending edge portion to the second longitudinally extending edge portion or by braiding the material) so that a tire base layer including the reinforcing element 61 can be continuously produced.

[0185] Fig.10 The tubular material is shown in a flattened state. To maintain the flattened shape, the tubular material on the first side 62 (e.g., above) of the first and second reinforcing elements 12a, 12b is fixed to the tubular material on the second side 64 (e.g., below) of the first and second reinforcing elements. The first side 62 and the second side 64 are located on opposite sides of the reinforcing elements 12a, 12b.

[0186] Fig.11 A cross section taken perpendicular to the longitudinal length of a tire base layer is shown including reinforcing elements 61. The tubular material on a first side 62 (e.g., above) of the first and second reinforcing elements 12a, 12b is secured to the tubular material on a second side 64 (e.g., below) of the first and second reinforcing elements.

[0187] Fig.12a Analogously to FIG. 12 b , a cross section of a tire base layer including reinforcing elements 61 is shown, taken perpendicularly to its longitudinal extent. Fig.12a Each of the figures in Figure 12a and Figure 12b shows a puncture protection layer 50. In each case, the puncture protection layer 50 is provided at the middle portion 66 of the tubular tire base layer including the reinforcing element 61. When the tire base layer is used in a tire, the middle portion 66 of the tire base layer including the reinforcing element 61 will coincide with the tread of the tire, and the first side portion 67 and the second side portion 68 of the tire base layer including the reinforcing element 61 will coincide with the sidewall of the tire. The middle portion 66 will be located adjacent to the ground contact area of ​​the tire. The puncture protection layer 50 is therefore located to at least coincide with the tread of the tire to provide the most useful protection.

[0188] Fig.12aThe puncture protection layer 50 is illustrated as being disposed on the radially outer side of the tubular material 60 when viewed from a cross section perpendicular to the longitudinal length of the tubular material. The puncture protection layer 50 may be continuously secured to the tire base layer tape. In a later step, the tread may be applied so that the puncture protection layer is located between the tread and the tire base layer, or the tread may be applied so that the tire base layer is located between the puncture protection layer 50 and the tread.

[0189] 12b illustrates a puncture protection layer 50 disposed on the radially inner side of the tubular material when viewed in a cross section perpendicular to the longitudinal length of the tubular material. The puncture protection layer may be inserted into the hollow portion of the tubular material when forming the tubular configuration (such as by securing the first longitudinally extending edge portion to the second longitudinally extending edge portion or by braiding the material) so that a tire base layer including the reinforcing element 20 and the puncture protection layer can be continuously produced.

[0190] The tire base layer including the reinforcing element 61 can be continuously produced. In this way, a tire base layer continuous band can be formed. This means that the tire base layer including the reinforcing element 61 enough to use can form multiple tires without manual intervention. The tire base layer including the reinforcing element 61 can be wound onto a reel for storage. The tire base layer continuous band including the reinforcing element 61 can be pulled out from the reel and cut into the length that needs further processing for use in the tire. The tire base layer continuous band including the reinforcing element 61 can be directly pulled into another device from the reel to process the tire base layer continuous band including the reinforcing element 61 used in the tire. In this way, processing can remain continuous.

[0191] In some examples, the tire base layer continuous strip is further processed to change the shape of the tire base layer including reinforcing elements 20, 61. The shape is modified to more closely match the shape of the tire base layer when used in a tire.

[0192] The modified shape will therefore have at least some curved features, reflecting Fig.13 Hyperbolic tire shape shown. The hyperbolic tire shape includes a curvature with a radius of curvature r in a transverse cross section and a curvature with a radius of curvature R in a cross section perpendicular to the longitudinal cross section of a cylindrical tire. The hyperbolic tire shape can also be described as a toroidal segment with an omega "Ω" cross section.

[0193] The tire base layer having a hyperbolic shape will include a first sidewall 74 including a first side portion of the tire base layer 54, 67 and a second sidewall 78 including a second side portion of the tire base layer 58, 68. The sidewalls 74, 78 extend generally radially and circumferentially around a radius of curvature R. The middle portion of the base layer 52, 66 will form an intermediate wall 72 extending generally circumferentially and axially around the radius of curvature R.

[0194] The size of the curvature of the tire base layer need not match the size of the curvature of the tire and / or the curvature that the base layer will adopt in the final tire. The curvature provided to the tire base layer including the reinforcing elements 20, 61 can be less than the final curvature in order to introduce a degree of shaping before assembling the tire, or the curvature provided to the tire base layer including the reinforcing elements can be greater than the final curvature in order to compensate for shrinkage that may occur during further processing of assembling the tire.

[0195] The wheel 80 can be used to shape a tire base layer including reinforcing elements 20, 61. The tire base layer including reinforcing elements 20, 61 is stretched over the surface of the wheel 80 and heat is applied so that the tire base layer including reinforcing elements 20, 61 adopts a certain curvature. Fig.14 As shown, the surface of the wheel 80 has a curvature radius r in a transverse cross section and a curvature radius R in a cross section perpendicular to the transverse cross section, because the tire base layer including the reinforcing elements 20, 61 stretched over the wheel adopts a hyperbolic tire shape. By inverting a portion of the tire base layer including the reinforcing elements 20, 61 to produce depressions and protrusions (such as Fig.21 The final formed tire base layer including the reinforcing elements 20, 61 can be manipulated into a substantially flat shape for further use.

[0196] A tire base layer including reinforcing elements 20, 61 may be formed into a hyperbolic tire shape using a segmented mold 90 that includes a cavity 92 that includes at least a portion of the hyperbolic tire shape. Fig.15 Such a segmented mold 90 is shown. The tire base including the reinforcing elements 20, 61 can be provided as a continuous strip of the tire base and drawn into the cavity 92, the upper and lower portions 94, 96 of the segmented mold closed to compress the tire base including the reinforcing elements 20, 61 within the cavity 92 and apply heat and pressure.

[0197] The tire base layer obtained by molding using the segmented mold 90 is Fig.16 The cavity 92 and the formed tire base layer have a curvature r in the transverse cross section and a radius R in the cross section perpendicular to the transverse cross section.

[0198] Fig.17 An alternative segmented mold 90 is shown in which a cavity 92 includes multiple segments. The shaped tire base layer including the reinforcing elements formed by the mold can be further manipulated (eg, bent or stretched) to eliminate joints between segments and form a continuous curvature.

[0199] Fig.18A cross section (cut through the center of the mold) of a substantially flat tire base mold 100 is shown for preforming a tire base including reinforcing elements 20, 61. The cavity 101 created between the top sheet piece 102 and the bottom sheet piece 103 comprises depressions and protrusions extending in the transverse direction of the cavity 101 and in the longitudinal direction of the cavity 101.

[0200] Fig.19 A substantially flat bottom sheet piece 103 of a tire base mold 100 is shown having a plurality of depressions and protrusions.

[0201] Fig. 20 Contour diagrams of depressions and protrusions along a substantially flat tire base mold 100 are shown. Protrusions and depressions in the longitudinal direction of the cavity of the substantially flat tire base mold are shown along line LL; 104 indicates a peak and 105 indicates a valley. Depressions in the transverse direction are shown along line t1-t1; a high point 106 drops to a valley 105 and then rises to another high point 106. Protrusions in the transverse direction are shown along line t2-t2; a low point 107 rises to a peak 104 and then drops back to a low point 107.

[0202] Once the tire base layer including the reinforcing elements is removed from the substantially flat tire base layer mold 100, the depressions are reversed, i.e., inverted, so that the tire base layer including the reinforcing elements follows a single curvature in the longitudinal direction of the tire base layer including the reinforcing elements. Once the depressions are inverted, the curvatures provided by the depressions and protrusions are added together to form a segment of a circle. Likewise, the depressions and protrusions in the transverse direction now adopt complementary curvatures to form the sidewalls of the segment of the circle and form an "Ω"-shaped cross section.

[0203] In other words, the curvature adopted by the tire base layer including the reinforcing elements 20, 61 in the transverse direction assists in forming the sidewalls of the base layer within the tire, thereby assisting in forming the "Ω" cross section. The curvature adopted by the tire base layer including the reinforcing elements 20, 61 in the longitudinal direction of the base layer assists in forming the tire annular ring.

[0204] Fig.21 A tire base layer is shown comprising reinforcing elements 20, 61 which are preformed into a substantially flat shape comprising depressions and protrusions in the longitudinal and transverse directions.

[0205] In some examples, the substantially flat shape of the tire base layer including the reinforcing elements is stored in the described form and can be used later in a further process to form a tire. In some examples, the substantially flat shape of the tire base layer including the reinforcing elements is used directly in a further process to form a tire, and the inversion of the concavities and convexities occurs after a subsequent processing step.

[0206] Fig. 22A cross section of a tire including a base layer is shown, the base layer being formed by a base layer including the reinforcing elements 20, 61 described above. The tire includes a tread 126 applied to an intermediate wall 72 of the base layer. In some examples, the tread may extend along the sidewalls 74 and 78 of the tire base layer. The tire tread is added to the tire base layer including the reinforcing elements 20, 61 using an injection molding device. The injection molding device includes a tread mold into which the tire base layer including the reinforcing elements 20, 61 is placed. The tire base layer including the reinforcing elements 20, 61 is located in the tread mold for overmolding. The elastomer is injection molded on the tire base layer including the reinforcing elements 20, 61 so that the tread is overmolded onto the tire base layer including the reinforcing elements 20, 61. In an example where the tire base layer is formed by a fabric or mesh fabric sheet, the injection molding material will penetrate the tire base layer and thus extend from one side of the tire base layer to the opposite side of the tire base layer.

[0207] Whether provided as a continuous strip of tire base (on a spool or otherwise) or provided as cut-to-size sections of the tire base including reinforcing elements, and / or whether provided flat or preformed as discussed above, the tire base including reinforcing elements can be further processed to add a tire tread using overmolding, an example of which is provided below.

[0208] exist Fig.23 , an injection molding apparatus 110 is shown receiving a tire base layer directly from a folding apparatus 30, the tire base layer including reinforcing elements 20, 61 in the form of a continuous strip of the tire base layer. The cavity of the tread mold 120 may have the same configuration as described above with respect to the tire base layer mold and with reference to Figures 18 to 20 The substantially flat shape described. Fig.24 , a substantially flat tread mold is shown below. A lower half 120a of the substantially flat tread mold 120 is provided on a fixed portion of the injection molding apparatus 110, and an upper half 120b of the substantially flat tread mold 120 is provided on a portion of the injection molding apparatus that can move relative to the fixed portion. When the two halves of the tread mold 120 are separated, a continuous strip of tire base layer is supplied from the folding apparatus 30 and aligned with the lower half of the tread mold 120a. The upper half 120b of the tread mold is moved so as to close the mold 120 and inject thermoplastic into the cavity of the mold. Once the injected thermoplastic solidifies and takes the shape of the cavity of the tread mold, the upper half 120b of the tread mold is moved away from the lower half 120a, and the continuous strip of tire base layer and the overmolded tread are pulled out of the tread mold. While the tire base layer continuous strip and the overmolded tread are moving, another tire base layer including the reinforcing elements included in the continuous strip is pulled from the folding device 30 into the injection molding device 110 .

[0209] A continuous strip of tire base layer may be fed from a reel into the injection molding apparatus 110 .

[0210] Fig.24 A section of a substantially flat tread mold 120 is shown, the section including a tread pattern 125 on a cavity wall 124 of a lower sheet 123 .

[0211] Fig.25 A tire base layer having reinforcing elements 20, 61 and an overmolded tire tread 126 having a substantially flat shape are shown. The substantially flat shape of the combined tread 126 and the tire base layer including reinforcing elements 20, 61 are the result of the overmolding step, that is, a flat strip of the tire base layer may be inserted into a tread mold 120, and the application of an elastomer to form the tread 126 combined with the application of heat and pressure during the overmolding process may cause the tire base layer including reinforcing elements 20, 61 to adopt the shape of the depressions and protrusions of the substantially flat tread mold 120. In other examples, the tire base layer including reinforcing elements is pre-formed prior to entering the substantially flat tread mold 120, and the shape of the tire base layer and tread after overmolding may facilitate the tread molding process and pre-forming.

[0212] Fig.26 A segmented tread mold 130 is shown including a segmented cavity 132 formed into a hyperbolic tire shape. Fig. 27 A tire base layer is shown, the tire base layer including reinforcing elements 20, 61 and an overmolded tread 126 formed using a segmented tread mold 130, the overmolded tread including the hyperbolic tire shape described above with radii r and R. The combined overmolded tread 126 and the hyperbolic tire shape of the tire base layer 20, 61 may be the result of using an elastomer to form the tread 126 in conjunction with the application of heat and pressure during the overmolding process. A preformed tire base layer including reinforcing elements 20, 61 may be inserted into the segmented mold 130, the shaping of which may contribute to the final shape of the combined tread 126 and the tire base layer including reinforcing elements 20, 61.

[0213] Fig.28 A tread mold 140 is shown including a cavity 142 shaped into multiple segments of a hyperbolic tire shape. Fig.29 The resulting tire base layer is shown including reinforcing elements 20, 61 and overmolded tread 126. The joints between adjacent segments of the base layer and overmolded tread have been manipulated (eg, bent or stretched) compared to the shape of the cavity of tread mold 140 so as to form a continuous curvature. Fig.29 The shape shown can be further manipulated into a round tire shape if desired.

[0214] The tire base including the reinforcing elements 20, 61 may be preformed as described above, and the tread is then overmolded onto the preformed tire base. In some examples, the size of the tire base is larger than the size of the tread mold. Fig.30 As shown, when the tire base layer including reinforcing elements 20, 61 is preformed into a substantially flat shape, the amplitude and wavelength of the depressions and protrusions are greater than the equivalent amplitude and wavelength of the substantially flat tread mold 120. That is, the height variation between the low point 107 and the peak 104, the high point 106 and the valley 105 of the tread mold 120, and the distance between the peak 104 and the valley 105 are all smaller than those of the preformed tire base layer. For clarity, Fig.30 The tread pattern 125 of the tread mold 120 has been omitted.

[0215] The relative differences in the amplitude and wavelength of the depressions and protrusions between the preformed tire base and the tread mold vary according to the thermal expansion characteristics of the tire base and the tread elastomer. In some cases, the amplitude and wavelength of the depressions and protrusions of substantially flat tread mold 120 are greater than the equivalent amplitude and wavelength of the preformed tire base. Alternatively, some dimensions may be larger in the substantially flat tread mold, while some dimensions are smaller compared to the preformed tire base.

[0216] Fig.31 A first segment of tire base layer 202 and a second segment of tire base layer 212 are shown. The first segment of tire base layer 202 includes a first end 204, a first main portion 206, and a first pair of reinforcing elements 208. The second segment of tire base layer 212 includes a second end 214, a second main portion 216, and a second pair of reinforcing elements 218. The first segment of tire base layer end 202 and the second segment of tire base layer end 212 are aligned and engaged as shown so that the reinforcing elements of the first pair of reinforcing elements 208 are aligned with the reinforcing elements of the second pair of reinforcing elements 218.

[0217] The first tire base section and the second tire base section may be flat, such as Fig.31 The first section of the tire base and the second section of the tire base may be preformed to include a curve. Fig.32 As shown, the first and second segments of the tire base layer can be preformed to have a hyperbolic shape, i.e., a curvature having a radius of curvature r in a transverse cross section and a curvature having a radius of curvature R in a cross section perpendicular to the longitudinal cross section of the cylindrical tire. The hyperbolic tire shape can also be described as a toroidal segment with an omega "Ω" cross section. The base layer will then have the first and second sidewalls 74, 78, and the intermediate wall 72 as described above.

[0218] The first segment of tire base layer 202 and the second segment of tire base layer 212 may be produced in a known manner.

[0219] The first section of tire base layer 202 and the second section of tire base layer 212 can be made by using any of the steps of the method for manufacturing a continuous strip of tire base layer described above. Before the joining operation, the continuous strip of tire base layer can be cut into the first section of tire base layer and the second section of tire base layer separated from each other and each having a predetermined length. Alternatively, before the joining operation, the continuous strip of tire base layer can be cut into individual pieces having a predetermined length, and then first.

[0220] The first tire base layer 202 and the second tire base layer 212 may be continuous. Fig.33 That is, the first end 204 and the second end 214 are arranged at the longitudinal ends of the same piece of the tire base. Therefore, only a single joint is required to form a complete ring of the tire base.

[0221] In other examples, multiple joints are required to form a complete base ring suitable for use in a tire. Fig.34 As shown, the first section of tire base layer 202 of one joint also provides the second section of tire base layer 212 for the other joint.

[0222] The contact area 220 is located between the first end 204 and the second end 214. Fig.35 and Fig.36 As shown. Fig.35 In the embodiment, the contact area 220 is formed by overlapping the first end 204 with the second end 214 to form a double-thickness tire base layer in the contact area 220. Fig.36 In the embodiment, the contact area 220 is formed by first segment base layer 203 ( Fig.31 The longitudinal surface of the second base layer 213 (shown) Fig.31 The longitudinal surfaces of the components are adjacent to each other.

[0223] A welding operation may then be performed in the contact area to secure the first segment of tire base layer 202 and the second segment of tire base layer 212 to each other. The first segment of tire base layer 202 and the second segment of tire base layer 212 may additionally or alternatively be secured by providing glue or an adhesive material between the first segment of tire base layer 202 and the second segment of tire base layer 212 in the contact area.

[0224] exist Fig.37 , an example is shown in which the first end portion 204 and the second end portion 214 include only a mesh fabric, while the first main portion 206 and the second main portion 216 include a mesh fabric and an elastomer. By at least partially overlapping the two end portions 204, 214, a contact area 220 ( Fig.3820). The joining of the two ends 204, 214 can then be achieved by overmolding the elastomer over the first end 204, the contact area 220, and the second end 214. Piece 222 represents an overmolded piece that will be added to the joined base layer once the overmolding process is performed. Piece 222 will therefore extend from the first main part 206 to the second main part 216 and join the first main part 206 to the second main part 216. By ensuring that the ends of the contact area 220 and the joints of the overmolded elastomer with the first main part 206 and the second main part 216 are staggered, a stronger joint can be made by avoiding the staggering of weak points at each joint. However, sufficient results are achieved by completely overlapping the first end 214 with the second end 204 to form the contact area 220. Since the mesh fabric has an open structure, the elastomer can penetrate the mesh fabric to produce a strong joint by improving the mechanical bonding between the first base layer and the second base layer and the chemical bonding between the elastomer and the fibers. Using this process, other base materials including fibers can also achieve similar advantages.

[0225] Specifically, when the contact area 220 is created by abutting the longitudinal end faces of the first section of the base layer 203 and the second section of the base layer 213, the end faces 203, 213 may have the following characteristics: Figures 39a to 39d The complementary shapes shown are such that the faces interlock when joined. Fig.39a In the embodiment, the end faces 203, 213 each have a straight line shape oriented perpendicular to the longitudinal length of the corresponding first and second segments of the tire base. Fig.39b In the embodiment, the end face has a plurality of lengths perpendicular to the length of the tire base layer, and the plurality of lengths form a stepped shape, which provides more contact surface area between the end faces. The longitudinal end face of the first segment of the tire base layer 203 has a stepped shape to also have a recess 205, and the longitudinal end face of the second segment of the tire base layer 213 has a stepped shape to also have a protrusion 215. The protrusion 215 fits into the recess 205. Fig.39c In the embodiment, the longitudinal end face of the second tire base layer 213 has an extended herringbone shape, and the longitudinal end face of the first tire base layer 203 has a cut herringbone shape. The herringbone shape is formed by a plurality of lengths that are not perpendicular to the longitudinal length of the tire base layer. Fig.39d In the embodiment, the longitudinal end surface of the second segment tire base layer 213 has a convex arc shape, and the longitudinal end surface of the first segment tire base layer 203 has a concave arc shape.

[0226] The insert 230 may be placed between the first segment of tire base layer 202 and the second segment of tire base layer 212 . Fig.40aThe insert 230 is shown located between the end surfaces 203, 213. The reinforcing elements 12 of the first and second tire base sections 203, 213 are aligned once joined. The insert is secured to each of the end surfaces 203, 213 to secure the first and second tire base sections 202, 212 to each other. Fig.40b An insert 230 is shown that includes an insert head 232 that protrudes above the first and second tire base segments 202, 212 and extends laterally and longitudinally above the first and second tire base segments 202, 212, while extending above the end portions 204, 214 and / or the main portions 206, 216.

[0227] exist Fig.40c , an example is shown in which a pair of reinforcing elements 12 extends through an insert 230 so that a connection can be established between a first pair of reinforcing elements and a second pair of reinforcing elements in a first section of tire base and a second section of tire base, respectively.

[0228] Fig.41a An expanded view of the joint is shown, ie, before contact is made and before joining is completed. Fig.41a The reinforcing elements 208 of the first section of the tire base layer 202 extending from the first end 204 are shown. The first pair of reinforcing elements 208 overlaps the second pair of reinforcing elements 218 in the longitudinal direction, so that once the joint is formed, the tips of the reinforcing element pair will abut each other. The tips can then be joined via welding, soldering, sewing or adhesive. For example, the stitching of the aramid reinforcing elements can be performed with aramid thread. Fig.41b This situation is shown in plan view. Fig.41c A similar example is shown where a first pair of reinforcement elements 208 and a second pair of reinforcement elements 218 extend from the first end 204 and the second end 214 , respectively, however the reinforcement elements overlap in the lateral direction.

[0229] Fig.42a A joint between a first segment of tire base layer 202 and a second segment of tire base layer 212 is shown, the joint including a cushioning material 240 joined to the first end 204 and the second end 214 .

[0230] Figure 42b An example is shown in which the first segment of tire base layer 202 and the second segment of tire base layer 212 are formed in a hyperbolic shape. Fig.42c Shows Figure 42b2 (i.e., without contact and engagement), which shows the location and extent of the gasket material 240 at the joint. The gasket material 240 extends from the radially outer surface (not shown) of the first side wall 74 relative to the radius of curvature r to the radially inner surface 73 of the first side wall 74 relative to the radius of curvature r, along the radially inner surface 72a of the intermediate wall 72 relative to the radius of curvature r, along the radially inner surface (not shown) of the second side wall 78 to the outer surface 77 of the second side wall 78.

[0231] The liner 240 can extend around the entire joint and can be considered a sleeve. The sleeve 240 can be tight enough and / or include an adhesive to secure the first section of the tire base layer 202 and the second section of the tire base layer 212 to each other. In some examples, the liner 240 includes fibers that provide additional strength.

[0232] Fig.43 An example is shown in which a liner 240, a first segment of tire base 202, and a second segment of tire base 212 include fibers. The fiber direction of each component is indicated in the direction of the cross-hatching in the figure. The fiber direction of the liner 240 is substantially aligned with the fiber direction of the first segment of tire base 202 and the second segment of tire base 212. In some examples, the liner 240 additionally or alternatively includes fibers extending in the longitudinal direction of the first segment of tire base 202 and the second segment of tire base 212. It should be understood that the liner and / or the first segment of tire base and the second segment of tire base may additionally include fibers extending in the longitudinal direction of the first segment of tire base 202 and the second segment of tire base 212. Fig.43 Fibers extending in a direction alternative to the direction indicated.

[0233] exist Fig.44a , the first segment of tire base layer 202 includes a first tread portion 252, and the second segment of tire base layer 212 includes a second tread portion 254. The first tread portion 252 is disposed over the first main portion 206 of the first segment of tire base layer 202 above the intermediate wall 72, but does not extend beyond the first end portion 204. The second tread portion 254 is disposed over the second main portion 216 and the second end portion 214. Once engaged according to any of the above discussions, the first end portion is disposed below (radially inwardly) the second end portion such that the first tread portion 252 is adjacent to the second tread portion 254.

[0234] exist Figure 44b , a first tread portion 252 extends over the first main portion 206 and the first end portion 204, and a second tread portion 254 extends over the second main portion 216 and the second end portion 214. A contact area 220 is provided by the longitudinal end faces of the first and second segments of the tire base and the tread portions so that the first and second segments of the tire base are fixed to each other and the first and second tread portions are fixed to each other.

[0235] In examples where an insert 230 is used, the insert may include an insert tread portion 234 , which may be provided on or in place of the insert head 232 .

[0236] Fig.45 A joining apparatus 260 is shown for joining the first length of tire base layer 202 with the second length of tire base layer 212. The joining apparatus includes a clamp 262 for holding the first and second lengths of tire base layer in place so that the ends 204, 214 can be properly joined. Fig.45 The illustrated bonding apparatus is configured to apply heat and pressure between the top clamping surface 264 and the bottom clamping surface 266 to form a bond.

Claims

1. A method of providing a joint between a first tire base layer end portion and a second tire base layer end portion, the method comprising: providing a first length of a tire base ply, the first length of the tire base ply comprising a first end portion, a first main portion, and a first pair of reinforcing elements; providing a second length of tire base ply, the second length of tire base ply comprising a second end portion, a second main portion, and a second pair of reinforcing elements; The first end portion and the second end portion are joined together such that each reinforcement element of the first pair of reinforcement elements is aligned with a corresponding reinforcement element of the second pair of reinforcement elements. 2 . The method of claim 1 , wherein the first pair of reinforcing elements comprises a first pair of bead wires and the second pair of reinforcing elements comprises a second pair of bead wires.

3. The method of claim 1 or 2, wherein the first length of tire base ply is continuous with the second length of tire base ply such that the first end portion and the second end portion are opposing longitudinal ends of a single tire base ply.

4. A method according to claim 1, 2 or 3, comprising joining the first end portion to the second end portion via a sleeve, a seam, welding, solder and / or glue.

5. The method of any one of claims 1 to 4, wherein joining the first end portion and the second end portion together comprises: forming a contact area between the first end portion and the second end portion of the tire base layer; as well as A welding operation is performed to join the first end portion and the second end portion in the contact area.

6. The method of any preceding claim, wherein joining the first length of tire base ply and the second length of tire base ply together comprises: forming a contact area between the first end portion and the second end portion of the tire base layer; And the method comprises: Glue is provided in the contact area, and pressure is applied to the contact area.

7. The method of any one of claims 5 or 6, wherein forming a contact area between the first end portion and the second end portion of the tire base layer comprises placing the first end portion over the second end portion.

8. The method according to any one of claims 5 or 6, wherein the first end portion is a first longitudinal surface of the tire base layer of the first length, and the second end portion is a second longitudinal surface of the tire base layer of the second length; and wherein forming a contact area between the first end portion and the second end portion includes making the first end portion abut the second end portion.

9. The method of claim 8, wherein the first longitudinal end and the second longitudinal end of the length of tire base layer have complementary shapes so that when the first end portion and the second end portion of the length of tire base layer are abutted, a continuous tire base layer with parallel sides is produced.

10. The method of claim 9, wherein the first longitudinal end and the second longitudinal end: being formed into a single length, the single length being perpendicular to the length of the tire base layer; being formed into a plurality of lengths, each length being perpendicular to the length of the tire base layer; is shaped not to be perpendicular to the length of the tire base layer; or Shaped as a curved surface or multiple curved surfaces.

11. The method according to any one of claims 5 to 10, wherein the reinforcing elements extend in a longitudinal direction from the first end portion and / or the second end portion of the respective first length of tire base layer and the respective second length of tire base layer so that the reinforcing elements abut and / or overlap when the contact area is formed.

12. The method of claim 1, 2 or 3, wherein joining the first end portion and the second end portion together comprises positioning an insert between the longitudinal face of the first length of tire base layer and the longitudinal face of the second length of tire base layer.

13. The method of claim 12, wherein the insert includes a head portion extending at least partially over the first end portion and the second end portion.

14. A method according to claim 12 or 13, wherein the reinforcing element extends in the longitudinal direction from the first end portion and / or the second end portion of the corresponding first length of tire base layer and the corresponding second length of tire base layer, so that when the insert is arranged between the longitudinal surface of the first length of tire base layer and the longitudinal surface of the second length of tire base layer, the reinforcing elements are adjacent and / or overlapping.

15. The method of claim 14, wherein the reinforcement elements of the first pair of reinforcement elements are joinable to corresponding reinforcement elements of the second pair of reinforcement elements via a sleeve, a seam, welding, solder or glue.

16. A method according to any preceding claim, wherein the method comprises: A liner material is bonded to the first length of tire base ply and the second length of tire base ply so as to overlap the junction between the first end portion and the second end portion.

17. The method of claim 16, wherein the liner material and the first length of tire base layer and the second length of tire base layer comprise fibers, and wherein the liner material is bonded to the first length of tire base layer and the second length of tire base layer such that the fibers of the liner material are aligned with the fibers of the first length of tire base layer and the second length of tire base layer.

18. The method of claim 16 or 17, wherein the liner material comprises fibers such that once bonded to the first length of tire base layer and the second length of tire base layer, the liner material comprises fibers aligned with the longitudinal length of the tire base layer.

19. A method according to claim 16, 17 or 18, wherein the lining material is provided on lower surfaces of the first and second main portions.

20. The method of claim 19, wherein the lining material extends continuously from the lower surfaces of the first and second main portions, across the longitudinal edges of the lengths of substrate, and to the upper surfaces of the first and second lengths of substrate.

21. A method according to any one of claims 16 to 20, wherein the lining material is placed in position over the joint prior to joining the first and second end portions.

22. A method according to any one of claims 1 to 4, comprising: The method according to any preceding claim is performed a sufficient number of times to form a circular ring of tire base layer.

23. A method according to any preceding claim, wherein the first length of tire base layer and the second length of tire base layer comprise a hyperboloid tire shape, wherein the hyperboloid tire shape has a radius r in a transverse cross section and a radius of curvature R in a cross section perpendicular to the transverse cross section.

24. The method according to claim 23, wherein the method comprises: Heat is applied to the tire base layer and the tire base layer is stretched over the surface of the wheel so that the tire base layer adopts a hyperboloid tire shape.

25. The method of claim 23, wherein providing each of the first length of tire base layer and the second length of tire base layer with a hyperbolic shape comprises providing a certain length of tire base layer with a basically flat shape, wherein the basically flat shape comprises at least one depression and at least one ridge, wherein each depression and ridge extends and is inclined in both a lateral direction and a longitudinal direction of the tire base layer.

26. The method of claim 25, wherein the length of tire base layer comprising a hyperboloid tire shape is manufactured by: Providing a certain length of tire base layer; inserting the length of tire base layer into the cavity of a base layer mold; and Applying heat and pressure; wherein: The base layer mould is a substantially flat mould comprising a shell including at least one longitudinal inner cavity extending between at least two opposing main walls and two opposing edge walls, wherein: Each of the main walls has at least one protrusion and at least one depression; Each ridge and each depression extends and slopes in both the transverse direction and the longitudinal direction of the cavity; The ridges and depressions are arranged alternately along the length of the mold; and The protrusion of one main wall is opposite to the depression of the other main wall.

27. The method of claim 23, wherein the length of tire base layer comprising a hyperboloid tire shape is manufactured by: Providing a certain length of tire base layer; inserting the length of tire base layer into the cavity of a base layer mold; and Applying heat and pressure; wherein: The shape of each of the first length of tire base ply and the second length of tire base ply comprises a segment of a cylindrical tire.

28. A method according to any preceding claim, wherein the first length of tire base ply and / or the second length of tire base ply comprises a tread.

29. The method of claim 29, wherein the tread is an overmolded tread and is provided by: Inserting a length of tire base ply into the tread mold; injecting an elastomeric material into the tread mold; allowing the elastomeric material to solidify so that the elastomeric material and the tire base layer adopt the shape of the tread mold; and The combined tire base layer and elastomeric material are removed from the tread mold.

30. The method of claim 30, wherein the tread mold is a substantially planar tread mold comprising a shell including at least one longitudinal inner cavity extending between at least two opposing main walls and two opposing edge walls, wherein: Each of the main walls has at least one protrusion and at least one depression; Each ridge and each depression extends and slopes in both the transverse direction and the longitudinal direction of the cavity; The ridges and depressions are arranged alternately along the length of the tread mold; and The protrusion of one main wall is opposite to the depression of the other main wall.

31. The method of claim 31, wherein the first length of tire base layer and / or the second length of tire base layer is provided according to claim 25, wherein the sizes of the depressions and the protrusions of the tire base layer are larger than the sizes of the depressions and the protrusions of the tread mold.

32. The method of claim 30, wherein the shape of the cavity of the tread mold comprises at least one segment of a cylindrical tire.

33. The method of claim 33, wherein the first length of tire base layer and the second length of tire base layer are provided according to any one of claims 22 to 27, and the radius of curvature adopted by the first length of tire base layer and the second length of tire base layer is greater than the radius of curvature of the cavity of the tread mold.

34. A method according to any preceding claim dependent on claims 7 to 15, wherein the first end portion, the first main portion and the second main portion include a tread, and the second end portion does not include a tread, and the joining of the first end portion and the second end portion includes joining the tread of the first end portion to the tread of the second main portion, and / or joining the tread of the first end portion to the tire base layer of the second end portion.

35. The method of claim 36, wherein the tread of the first end portion extends beyond the tire base layer of the first end portion in the longitudinal direction of the tire base layer.

36. A method according to any preceding claim, wherein the first length of tire base ply and the second length of tire base ply are each provided by: providing a sheet of material having a first lateral edge portion and a second lateral edge portion, wherein the first lateral edge portion is separated from the second lateral edge portion by a central portion, placing a first reinforcing element on the sheet at the intersection of the first lateral edge portion and the central portion, and placing a second bead wire on the sheet at the intersection of the central portion and the second lateral edge portion, folding said first transverse edge portion over said first reinforcing element, folding the second transverse edge portion over the second reinforcing element, and The first lateral edge portion and the second lateral edge portion are secured to the central portion.

37. A method according to claim 38, wherein the first length of base layer and / or the second length of base layer is provided in the form of a continuous tire base layer strip.

38. A tyre manufactured according to the method of any preceding claim.

39. An apparatus for joining a first length of tire base layer and a second length of tire base layer, the apparatus comprising a clamp for positioning a first end portion of the first length of tire base layer and a second end portion of the second length of tire base layer, and for performing a welding operation to join the first end portion and the second end portion.

40. The apparatus of claim 40, comprising means for cutting the continuous tire base ply strip into desired lengths to obtain the first length of tire base ply and / or the second length of tire base ply.

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