Method for turning up tire molding drums and tire components

Abstract

The present invention relates to a tire forming drum and a method for turning up a tire component, wherein the tire forming drum comprises a drum body rotatable about a drum axis, a turn-up bladder that is inflatable and extends circumferentially about the drum axis around the drum body to turn up a tire component supported by the turn-up bladder, and a plurality of pressing arms for pressing the turn-up bladder while turning up the tire component, wherein the tire forming drum comprises a plurality of hinges for hingeably connecting the pressing arms to the drum body, and when the turn-up bladder is not inflated, the plurality of hinges are located below the turn-up bladder, and an underlay extending radially between at least one of the plurality of hinges and the turn-up bladder is provided on the tire forming drum.

Description

Technology Field

[0001] The present invention relates to a tire forming drum and a method for turning up a tire component. Background Technology

[0002] WO 2019 / 199160 A1 discloses a tire forming drum comprising a first drum half, a second drum half, and a central section located axially between the first drum half and the second drum half. The tire forming drum is further provided with a turn-up bladder extending around the first drum half and the second drum half, for turning up a tire component supported by the turn-up bladder. The tire forming drum further comprises a plurality of pressing arms located between each drum half and an uninflated turn-up bladder to press the turn-up bladder while turning up the tire component. The pressing arms are hinged at each drum half at a position located below the turn-up bladder when uninflated.

[0003] A disadvantage of the known tire forming drum is that the turn-up bladder is directly supported by the pressing arm and its respective hinges. During the turn-up of the pressing arm, subsequently while the pressing arm returns to its resting position, and / or during the expansion or contraction of the tire forming drum, the turn-up bladder may get caught, trapped, or pinched between the pressing arm and / or its respective hinges. In particular, if the pressing arm is tilted during the turn-up operation, the turn-up bladder is forced toward and / or into any gap in the respective hinges. Repeated pinching can severely damage the turn-up bladder to the extent that it is no longer uniform or airtight and must be replaced. The problem to be solved

[0004] The objective of the present invention is to provide a method for turning up a tire molding drum and a tire component that can improve the lifespan of the turn-up bladder. means of solving the problem

[0005] According to a first embodiment, the present invention comprises a tire forming drum, a drum body rotatable about a drum axis; an inflatable turn-up bladder, the turn-up bladder extending circumferentially about the drum axis around the drum body to turn up a tire component supported by the turn-up bladder; and a plurality of pressing arms distributed circumferentially around the drum body, the plurality of pressing arms positioned between the drum body and the turn-up bladder to press the turn-up bladder while turning up the tire component; the tire forming drum comprises a plurality of hinges for hingeably connecting the pressing arms to the drum body, wherein when the turn-up bladder is not inflated, the plurality of hinges are located below the turn-up bladder, and an underlay extending radially perpendicular to the drum axis between at least one of the plurality of hinges and the turn-up bladder is to the tire forming drum Provides a tire forming drum that is prepared.

[0006] In the context of the present invention, the term 'underlay' should be interpreted as a layer of material placed under another for protection or support. The underlay can support the turn-up bladder against the drum body at at least one hinge position, thereby reducing the risk of the turn-up bladder getting caught at the at least one hinge. In particular, the underlay may have one or more of the following features: being able to slide more easily over the pressing arm than the turn-up bladder; being relatively stiff or having relatively high compression resistance along the pressing arm; having a larger minimum bending radius; and / or being relatively thick. Accordingly, the underlay itself is less likely to get caught or caught at the at least one hinge. Specifically, if the force applied to the underlay in the direction along the pressing arm exceeds the friction between the underlay and the pressing arm, the underlay may simply slide over the pressing arm, thereby reducing any tension in the turn-up bladder, which would otherwise force the turn-up bladder toward and / or into at least one hinge. Additionally, the minimum bending radius and / or thickness of the underlay may protect the turn-up bladder from any sharp edge or acute angle at the at least one hinge and provide a relatively smooth support surface for the turn-up bladder. Thus, the turn-up bladder is less likely to be damaged by the at least one hinge during the turn-up. Consequently, the lifespan of the turn-up bladder can be increased without modifying the turn-up bladder itself. Advantageously, the turn-up bladder can be configured to have optimal characteristics for turn-up without requiring reinforcement at the location of at least one hinge.

[0007] In one embodiment, the underlay has a first end secured to the drum body on the side facing away from the pressing arms at the plurality of hinges. Alternatively, the drum body includes a bead-lock section, and the underlay has a first end secured to the drum body on the side facing the bead-lock section at the plurality of hinges. By securing the underlay to the drum body at the first end, the underlay can be held in place at or near at least one hinge. In other words, it can be prevented that the underlay is moved out of place, which could potentially expose at least one hinge and damage the turn-up bladder.

[0008] In each of the embodiments described above, the underlay may have a second end opposite to the first end, and the second end rests on at least one of the pressing arms. When the second end rests on at least one pressing arm, the underlay may extend substantially across the at least one hinge from the first end fixed to the drum body to a position on the at least one pressing arm.

[0009] Preferably, the second end is free, unfixed, or unconstrained to slide over the at least one pressing arm in an arm direction parallel to the at least one pressing arm. Thus, the position of the second end on the at least one pressing arm can be passively followed or adjusted in response to a change in orientation of the at least one pressing arm, thereby allowing the at least one pressing arm to turn up and press the turn-up bladder.

[0010] Additionally or alternatively, the underlay can be transformed at least partially from a cylindrical configuration to a conical configuration. Thus, the conical portion of the underlay can passively follow the turn-up of a plurality of connected pressing arms or be adjusted to match the turn-up.

[0011] In one particular embodiment, the underlay comprises an underlay body that is annular at a first end and divided into a plurality of arm sections at a second end opposite the first end. Accordingly, the underlay body can cover a plurality of hinges in a continuous or substantially continuous manner at the first end, while passively following or adjusting to the orientation change and subsequent diameter expansion of the plurality of pressing arms at the second end.

[0012] Preferably, each arm section of a plurality of arm sections is configured to extend along each pressing arm of a plurality of pressing arms and rest on each pressing arm. Accordingly, each arm section, while being held on each pressing arm, can passively follow or adjust to changes in the orientation of each pressing arm.

[0013] In an additional embodiment, the underlay can be transformed from a cylindrical configuration to a conical configuration in a plurality of arm sections. As previously mentioned, the conical portion of the underlay can passively follow the turn-up of the connected plurality of pressing arms or be adjusted to match the turn-up.

[0014] Preferably, the underlay body is provided with a plurality of slits that divide the underlay body into a plurality of arm sections. Due to the slits, the arm sections can be variably spaced apart circumferentially at a second end in response to a change in orientation of the pressing arm. In particular, the arm sections can be deployed to follow the deployment of the pressing arm when moving toward a larger diameter or expanding.

[0015] More preferably, in the cylindrical configuration of the underlay body, a plurality of slits extend parallel to each other. Consequently, the arm sections formed by the slits can also likewise extend parallel to each other in the cylindrical configuration.

[0016] Most preferably, a plurality of slits extend over at least half the length of the underlay body between the first end and the second end. Thus, at least half the length of the underlay body can be extended from a cylindrical configuration to a conical configuration, and less than half of the underlay body can be maintained in a cylindrical configuration to effectively protect the turn-up bladder from a plurality of hinges.

[0017] In an additional embodiment, the underlay body comprises a plurality of bridge portions, each of the plurality of bridge portions interconnects a pair of arm portions of a plurality of arm portions at a first end, and each bridge portion has a circumferential elasticity greater than the circumferential elasticity of each pair of interconnected arm portions. Accordingly, in order to allow the underlay body to be mounted on the drum body at the first end, the diameter of the underlay body may be expanded at least at the first end. Additionally, the underlay may be removed from the drum body without damaging the underlay body.

[0018] Preferably, the underlay body has a first thickness in a plurality of arm sections and a second thickness smaller than the first thickness in a plurality of bridge sections. Through the reduced thickness or thinning of the bridge sections, the elasticity of the underlay body in each bridge section can be increased.

[0019] Additionally or alternatively, the underlay body comprises a material different from that of a plurality of arm sections in a plurality of bridge portions. The material of the bridge portions may be selected to have greater circumferential elasticity than the material of the plurality of arm sections.

[0020] In an additional embodiment, the underlay body comprises a different layer configuration compared to a plurality of arm sections in a plurality of bridge sections. In particular, the underlay body may comprise a laminate of a first layer having a first elasticity and a second layer having a second elasticity greater than the first elasticity, wherein the second layer is covered by the first layer in a plurality of arm sections and exposed in a plurality of bridge sections. Accordingly, the second layer is allowed to expand elastically in the circumferential direction in the bridge sections, whereas in the arm sections, its elasticity is limited by the first layer.

[0021] In another alternative embodiment, the underlay body is spliced ​​into an annular configuration at the first end. By splicing the underlay body, the underlay body itself does not necessarily have to be circumferentially elastic. Instead, it may not be circumferentially elastic.

[0022] In another alternative embodiment, the underlay comprises a plurality of arm sections extending individually from a first end toward a second end opposite the first end. By forming an underlay having individual arm sections, a bridge portion between the arm sections is not required, nor is elasticity required. Instead, each arm section can be individually mounted at a position on each pressing arm.

[0023] Preferably, each arm section of a plurality of arm sections is configured to extend along each pressing arm of a plurality of pressing arms and rest on each pressing arm. Accordingly, each individually mounted arm section can be maintained on each pressing arm and passively follow or adjust to changes in the orientation of each pressing arm.

[0024] In another embodiment, the underlay has a first end secured to the drum body by one or more fasteners. Accordingly, the underlay may be prevented from being separated from the drum body at the first end.

[0025] Preferably, the one or more fasteners include a group of fasteners comprising pins, bolts, clamps, or ridges. These fasteners may be mechanically coupled to the drum body, for example, by insertion, or may interact with the drum body in a form-fitting manner.

[0026] According to a second aspect, the present invention provides a method for turning up a tire component using a tire forming drum according to any one of the embodiments of the first aspect of the present invention, said method comprising:

[0027] - A step of providing the above underlay radially between at least one hinge and the turn-up bladder; and

[0028] - Includes the step of supporting the turn-up bladder on the underlay at at least one hinge while turning up the tire component.

[0029] The method according to the second aspect of the present invention relates to the actual implementation of the tire forming drum according to the first aspect of the present invention and thus has the same technical advantages, which will not be repeated below.

[0030] According to a third unclaimed aspect, the present invention provides an underlay for use in a tire forming drum according to any one of the embodiments of the first aspect of the present invention. The underlay according to the third aspect of the present invention has the same technical advantages when implemented in a tire forming drum according to the first aspect of the present invention, and these advantages will not be repeated below.

[0031] According to a fourth unclaimed aspect, the present invention provides the use of an underlay according to the third aspect of the present invention in a tire forming drum according to any one of the embodiments of the first aspect of the present invention. The use according to the fourth aspect of the present invention relates to actually implementing said underlay in a tire forming drum according to the first aspect of the present invention and thereby having the same technical advantages, which will not be repeated below.

[0032] The various embodiments and features described and presented in this specification may be applied individually whenever possible. These individual embodiments, in particular those described in the appended dependent claims, may be the subject of a divisional patent application. Brief explanation of the drawing

[0033] The present invention will be described based on exemplary embodiments illustrated in the attached schematic drawings, in which: FIG. 1 illustrates a cross-section of a tire forming drum having a drum body, a turn-up bladder, a pressing arm, and an underlay according to a first embodiment of the present invention prior to turning up a tire component; FIG. 2 illustrates a cross-section of a tire forming drum according to FIG. 1 during the turn-up of a tire component; FIG. 3 illustrates an isometric projection of an underlay of a tire forming drum according to FIG. 1; FIG. 4 illustrates a plan view of the underlay body prior to splicing the annular configuration; FIG. 5 illustrates an isometric projection of an alternative underlay having a plurality of bridge portions according to a second embodiment of the present invention; FIG. 6 illustrates a cross-section of an alternative underlay according to FIG. 5 in one of the bridge portions; FIG. 7 illustrates a cross-section of another alternative underlay in one of the bridge portions; FIG. 8 illustrates an isometric projection of another alternative underlay according to a third embodiment of the present invention; FIG. 9 illustrates a cross-section of an alternative tire forming drum having another alternative underlay according to a fourth embodiment of the present invention. Specific details for implementing the invention

[0034] FIGS. 1 and FIGS. 2 illustrate a tire forming drum (1) according to a first embodiment of the present invention for forming a green tire or an unvulcanized tire (not shown).

[0035] A tire forming drum (1) is positioned, adjusted, or configured to form the carcass of a tire by turning up a tire component (T), particularly a pre-assembly, around a bead (B). The pre-assembly typically includes an inner liner, one or more body plies, and a sidewall.

[0036] As illustrated in FIG. 1, the tire forming drum (1) comprises a drum body (10) rotatable about a drum axis (S). In this example, the drum body (10) is mounted on a drum shaft (9). The drum body (10) has an axial direction (A) parallel to the drum axis (S) and a radial direction (R) perpendicular to the drum axis (S) and / or the axial direction (A). In this example, the drum body (10) comprises only the drum half portions of the tire forming drum (1). The tire forming drum (1) comprises two of the aforementioned drum half portions positioned on both sides of a central section (not shown) in a manner known to itself. It should be noted that FIG. 1 illustrates only the portion of the drum body (10) on the drum axis (S). Each drum half portion is provided with a bead-lock section (11) for clamping a bead (B) to the drum body (10) on each side of the central section.

[0037] As best illustrated in FIG. 2, the tire forming drum (1) is provided with an expandable turn-up bladder (2). The turn-up bladder (2) extends circumferentially (C) around the drum axis (S) around the drum body (10). The turn-up bladder (2) comprises a sealed bladder body (20) having a first circumferential edge (21) and a second circumferential edge (22), the circumferential edges of which are clamped and sealed to the drum body (10) on both sides of the bead-lock section (11). In FIG. 1, the bladder body (20) is folded in two layers around the fold portion (23). In order to turn up the tire component (T) supported on the turn-up bladder (2), the bladder body (20) between the circumferential edges (21, 22) can be inflated from the non-inflated state as shown in FIG. 1 to the inflated state as shown in FIG. 2, the tire forming drum (1) can be connected to a source of compressed air that is positioned in an air communication relationship with the turn-up bladder (2). The turn-up bladder (2) is elastic in the circumferential direction (C).

[0038] As illustrated in FIGS. 1 and 2, the tire forming drum (1) additionally comprises a plurality of pressing levers or pressing arms (3) distributed in the circumferential direction (C) around the drum body (10). As illustrated in FIG. 1, when at least the pressing arm (3) is in the arm-down position and the turn-up bladder (2) is not inflated, the pressing arm (3) is positioned between the drum body (10) and the turn-up bladder (2) in the radial direction (R). In particular, in the non-inflated state of the turn-up bladder (2), the bladder body (20) is placed on the pressing arm (3). Each pressing arm (3) has an elongated arm body (30) extending in the arm direction (D). To press the turn-up bladder (2) while turning up the tire component (T), the pressing arm (3) is rotatable, tiltable, or pivotable from a level or arm-down position as shown in FIG. 1 to an inclined or arm-up position. In this way, the turn-up bladder (2) is pressed toward the tire component (T) and in close contact with the tire component during the turn-up. In the arm-down position of FIG. 1, the pressing arm (3) extends parallel to or substantially parallel to the axial direction (A). In particular, in the arm-down position, the pressing arm (3) forms a substantially cylindrical surface of the tire forming drum (1) to support the turn-up bladder (2).

[0039] The tire forming drum (1) includes a plurality of hinges (4) for hingeably connecting the pressing arm (3) to the drum body (10). The hinges (4) are distributed around the drum body (10) with respect to the drum axis (S). In this example, the hinges (4) are supported by annular arm supports. The hinges (4) are located on the side of the pressing arm (3) facing the bead-lock section (11), that is, on the side of the pressing arm (3) closest to the bead-lock section (11). In other words, in the arm lowering position, the pressing arm (3) extends from the hinges (4) in a direction away from the bead-lock section (11). Thus, the pivot of the pressing arm (3) toward the arm raising position of FIG. 2 includes at least a vector component in a direction parallel to the axial direction (A) toward the bead-lock section (11).

[0040] In this example, it should be noted that the second perimeter edge (22) of the bladder body (20) is clamped to the drum body (10) at a position between the bead-lock section (11) and the hinge (4). When the turn-up bladder (2) is not expanded, the fold (23) is placed on the pressing arm (3) at a position outside the area formed between the first perimeter edge (21) and the second perimeter edge (22). In other words, in the unexpanded turn-up bladder (2), at least the portion between the fold (23) and the second perimeter edge (22) covers the pressing arm (3). Additionally, when the turn-up bladder (2) is not expanded, a plurality of hinges (4) are located below the turn-up bladder (2) and are covered by the turn-up bladder.

[0041] As illustrated in FIGS. 1 and 2, the tire forming drum (1) is provided with a support layer or underlay (5) extending across or over the hinge (4). The underlay (5) is configured, positioned, or configured to support the turn-up bladder (2) against the drum body (10) at the location of the hinge (4). In particular, as illustrated in FIG. 1, when at least the pressing arm (3) is in the arm-down position and the turn-up bladder (2) is not expanded, the underlay (5) is positioned such that, when considered in the radial direction (R), the underlay extends between the hinge (4) and the turn-up bladder (2) or is located between them. Accordingly, the underlay (5) can prevent direct contact between the turn-up bladder (2) and the hinge (4).

[0042] In this exemplary embodiment, the underlay (5) has an underlay body (50). The underlay body (50) comprises a layer of material capable of effectively shielding the hinge (4) from the turn-up bladder (2). In this example, the layer of material is non-elastic or substantially non-elastic within the range of normal forces applied to the underlay body (50) during the turn-up. Alternatively, the layer of material may be elastic in only one direction, for example, only in the circumferential direction (C).

[0043] In this example, the underlay body (50) is manufactured from a material that is as durable as the material used for the conveyor belt. The durable material may be, for example, fabric. Alternatively, metal, for example spring steel may be used.

[0044] The underlay body (50) preferably has one or more of the following features:

[0045] - The friction coefficient of the underlay body (50) on the pressing arm (3) is lower than the friction coefficient of the turn-up bladder (2) on the pressing arm (3) when it is directly supported on the pressing arm (3), preferably 80% or less, and most preferably 50% or less;

[0046] - The compression resistance of the underlay body (50) along the pressing arm (3) is higher than the compression resistance of the turn-up bladder (2) along the pressing arm (3), preferably at least 120 percent, and most preferably at least 150 percent;

[0047] - The minimum bending radius of the underlay body (50) before bending is greater than the minimum bending radius of the turn-up bladder (2), preferably at least 120 percent, and most preferably at least 150 percent; and

[0048] - The thickness of the underlay body (50) is at least 1 millimeter, and preferably at least 2 millimeters.

[0049] As illustrated in FIG. 3, the underlay body (50) is continuous, ring-shaped and / or annular at the first end (51). The underlay body (50) is fixed to the drum body (10) at the first end (51). In this example, the first end (51) is mounted or fixed to the drum body (10) on the side facing away from the pressing arm (3) at the hinge (4). More specifically, the first end (51) is mounted or fixed to the drum body (10) at a position between the second circumferential edge (22) of the bladder body (20) and the hinge (4). The underlay (5) is fixed to the drum body (10) using a suitable fastener (7), such as a pin, bolt, or clamp.

[0050] In order to allow the annular first end (51) of the underlay body (50) to be installed or mounted around the drum body (10), the underlay body (50) may initially be provided as a band of material having a first splice edge (53), a second splice edge (54), and optionally a splice lip (55), as shown in FIG. 4, and may be joined or spliced ​​in an annular configuration around the drum body (10) by joining or splicing the first splice edge (53) to the second splice edge (54) or vice versa, with or without using the splice lip (55). The underlay (5) may be removed from the drum body (10) by separating the splice edges (53, 54), that is, by cutting the underlay body (50) along the joint or splice.

[0051] At the second end (52) opposite the first end (51), the underlay body (50) is supported by a plurality of pressing arms (3) or placed on a plurality of pressing arms. The second end (52) is not fixed, free, and / or constrained, and accordingly moves or slides freely along each of the arm bodies (30) on the pressing arms (3). In other words, the second end (52) can slide in the arm direction (D) on the arm bodies (30).

[0052] The underlay body (50) can be at least partially extended, changed, or modified from a cylindrical configuration as shown in FIG. 1 to a conical configuration as shown in FIG. 2. In particular, at the second end (52), near it, or towards the second end, the underlay (5) is provided with a plurality of cutouts or slits (56) that divide the underlay body (50) into a plurality of finger or arm sections (58). In the cylindrical configuration of the underlay (5) as shown in FIG. 3, the slits (56) extend parallel to each other and / or parallel to the drum axis (S), the axial direction (A), and the arm direction (D). Consequently, the arm sections (58) also extend parallel to each other. In particular, each arm section (58) extends parallel to the arm direction (D) of each pressing arm (3).

[0053] The underlay (5) is mounted on the drum body (10) in such a way that each arm section (58) extends along each pressing arm (3) of a plurality of pressing arms (3) and rests on each pressing arm. Due to the slit (56), the arm sections (58) can be variably spaced out in the circumferential direction (C) from the second end (52) in response to a change in orientation of the pressing arm (3). In particular, the arm sections (58) are deployed to follow the deployment of the pressing arm (3) when moving or expanding toward a larger diameter corresponding to the conical configuration of FIG. 2.

[0054] Each arm section (58) may have the same width or range along the same arc length as each pressing arm (3) in the circumferential direction (C), or may be wider than each pressing arm (3) so as to also extend into the circumferential gap between subsequent pressing arms (3). Accordingly, the arm section (58) may also prevent the turn-up bladder (2) from getting stuck or caught between the pressing arms (3) when the pressing arms (3) are retracted inward.

[0055] It should be noted that the plurality of slits (56) extend over at least half of the length (L) of the underlay body (50) between the first end (51) and the second end (52). In this example, the slits (56) extend over at least 70% of the length (L), and preferably at least 90%. Optionally, to prevent the slits (56) from tearing into the underlay (5) toward the first end (51) beyond each slit end (75), the slits (56) are terminated by appropriately formed slit ends (57), that is, rounded slit ends (57) having a specific minimum radius.

[0056] Additionally, the underlay (5) is provided with a mounting element (59), in particular a mounting hole, that accommodates the aforementioned fastener (7) for mounting the underlay body (50) to the drum body (10). Alternatively, the underlay (5) may be held to the drum body (10) using a pin that fits into the corresponding hole. For example, the fastener (7) may be a pin that fits into the mounting hole (59). In this case, when mounted on the underlay (5), the turn-up bladder (2) can prevent the pin from coming out of the mounting hole during use. Conversely, the pin may be connected to or integrated with the underlay, and the mounting hole may be provided in the drum body (10). Also, when mounted on the underlay (5), the turn-up bladder (2) can prevent the pin from coming out of the mounting hole during use.

[0057] FIGS. 5 and 6 illustrate an alternative underlay (105) according to a second embodiment of the present invention for use with a tire forming drum (1) according to FIGS. 1 and 2. The alternative underlay (105) differs from the aforementioned underlay (5) in that the underlay body (150) includes a plurality of bridge portions (106).

[0058] Each bridge portion (106) interconnects a pair of arm sections (58) at the first end (51). In this example, the bridge portion (106) is the only part of the underlay body (150) that interconnects the arm sections (58). In other words, the arm sections (58) are interconnected only by the bridge portion (106) at the first end (51).

[0059] Each bridge portion (106) has a circumferential elasticity (E) greater than the circumferential elasticity (C) of each pair of interconnected arm sections (58). As best illustrated in FIG. 6, the underlay body (150) has a first thickness (H1) in the plurality of arm sections (58) and a second thickness (H2) smaller than the first thickness (H1) in the plurality of bridge portions (106). The smaller thickness (H2) can effectively increase the elasticity (E) of the bridge portion (106) relative to the rest of the underlay body (150).

[0060] The alternative underlay (105) has a technical advantage over the previously mentioned underlay (5) in that the bridge portion (106) allows for an expansion of the diameter of the underlay body (150) for mounting the underlay body (150) to the drum body (10) at least at the first end (51), without the need to bond or splice the alternative underlay (105) to the drum body (10). Accordingly, the alternative underlay (105) may be manufactured and / or formed to have a continuous or annular first end (51) before installing or mounting the alternative underlay (105) to the drum body (10). Additionally, the alternative underlay (105) may be removed from the drum body (10) without damaging the underlay body (150).

[0061] FIG. 7 illustrates another alternative underlay (205) according to a third embodiment of the present invention for use with a tire forming drum (1) according to FIG. 1 and 2. The other alternative underlay (205) differs from the alternative underlay (105) of FIG. 5 and 6 in that a bridge portion (206) comprising a different layer configuration relative to a plurality of arm sections (58) is provided in the underlay body (250). In this example, the other alternative underlay (205) comprises a laminate of a first layer (261), a second layer (262), and a third layer (263). In the arm section (58), the second layer (262) is clamped between the other layers (261, 263), covered by at least one of the other layers, or attached thereto, whereas the second layer (262) is the only layer extending from the bridge portion (206). Accordingly, the second layer (262) is exposed in or within the bridge portion (206). The second layer (262) has greater elasticity (E) than the elasticity of the other layers (261, 263). In particular, the other layers (261, 263) may have no elasticity or substantially no elasticity in the circumferential direction (D), at least within the range of normal forces applied to the underlay body (250) during turn-up.

[0062] If the second layer (262) has sufficient elasticity (E) in the circumferential direction (C), and the second layer (262) does not interfere with the operating range of the pressing arm (3), for example, as an alternative to having a slit (56), the second layer may also extend toward or even to the second end (52) in the area between the arm sections (58).

[0063] Additionally, as an alternative to the stacked layers (261, 262, 263), it is conceived that the bridge portion (206) may include another material having elasticity (E) different from the material of the arm section (58).

[0064] FIG. 8 illustrates another alternative underlay (305) according to a fourth embodiment of the present invention for use with the tire forming drum (1) according to FIG. 1 and FIG. 2. The other alternative underlay (305) differs from the aforementioned underlay (5, 105, 205) in that it comprises a plurality of arm sections (358) that extend individually from a first end (351) toward a second end (52) opposite the first end (351). In other words, the arm sections (358) are not interconnected at the first end (51) or at any point along its length. Each arm section (358) is individually fixed, attached, or mounted to the drum body (10). Additionally, each arm section (358) extends along each pressing arm (3) and rests on each pressing arm. In order to ensure that each arm section (358) remains properly aligned with the pressing arm (3) on which it is placed, a plurality of mounting elements (359) may be provided for each arm section (358), for example, two spaced-apart mounting holes.

[0065] FIG. 9 illustrates an alternative tire forming drum (401) different from the aforementioned tire forming drum (1) in that it includes another alternative underlay (405) that is different from the previously mentioned underlays (5, 105, 205, 305) in that it is fixed or fastened to the drum body (410) at or near the first end (51) using a fastener (407) in the form of a ridge or ledge extending in the circumferential direction (C) around the drum axis (S). The ridge or ledge may be continuous or discontinuous in the circumferential direction (C). The drum body (410) is provided with a hole or groove (412) of a corresponding or complementary shape to receive the fastener (407) in a form-fitting manner. The other alternative underlay (405) is substantially clamped or inserted between the bladder (2) and the drum body (10).

[0066] A method of turning up a tire component (T) using the aforementioned tire forming drum (1) and using any one of the aforementioned underlays (5, 105, 205, 305) on the tire forming drum (1) will now be briefly explained with reference to FIGS. 1 and 2. It will be understood that any reference to the underlay (5) according to the first embodiment of the present invention may be applied mutatis mutandis to other underlays (105, 205, 305).

[0067] As illustrated in FIG. 1, the underlay (5) is provided between the hinge (4) and the turn-up bladder (2) in a cylindrical configuration that rests on the pressing arm (3) in the arm lowering position. The turn-up bladder (2) is not expanded and is directly supported by the underlay (5) at the hinge (4). The tire component (T) is applied around the tire forming drum (1) and has a portion inside the bead (B) in the bead-lock section (11) and a portion outside the bead (B) in the bead-lock section (11). In this example, the portion of the tire component (T) inside the bead (B) is formed into a toroidal shape at least partially. The portion of the tire component (T) outside the bead (B) rests on the turn-up bladder (2).

[0068] FIG. 2 illustrates a situation in which the turn-up bladder (2) is expanded and turned up to the portion of the tire component (T) outside the bead (B) around the bead (B) and to the portion of the tire component (T) inside the bead (B) and to abut it. The pressing arm (3) is turned up from the arm lower position to the arm raised position. The underlay (5) takes on a configuration that is at least partially conical in response to the turn-up of the pressing arm (3). The arm section (58) is held in place on each pressing arm (3). During the turn-up of the pressing arm (3), each arm section (58) may be moved or slid slightly in the arm direction (D) of each pressing arm (3) on which it is placed. However, the underlay (5) is maintained aligned with each pressing arm (3), and more specifically, is maintained in a position between the hinge (4) and the turn-up bladder (2) to effectively protect the turn-up bladder (2) from any sharp edge or acute angle formed on the hinge (4) as a result of the turn-up of the pressing arm (3).

[0069] After the turn-up, the pressing arm (3) can be returned to the arm lowering position of FIG. 1 or retracted, and the turn-up bladder (2) can be retracted again, after which the tire forming drum (1) is prepared for another cycle of the method. During the inward movement of the pressing arm (3), the underlay (5) can effectively prevent the turn-up bladder (2) from being pulled or pinched by the hinge (4).

[0070] It should be understood that the foregoing description is included to illustrate the operation of preferred embodiments and is not intended to limit the scope of the invention. From the foregoing description, many variations that may also fall within the scope of the invention will be apparent to those skilled in the art. Explanation of the symbols

[0071] 1 : Tire forming drum 10 : Drum body 11: Bead-Lock Section 2: Turn-Up Bladder 20: Bladder body 21: First circumferential edge 22: Second perimeter edge 23: Fold 3 : Pressing arm 30 : Arm body 4 : Hinge 40 : Arm support 5 : Underlay 50 : Underlay main body 51: 1st end 52: 2nd end 53 : 1st Splice Edge 54 : 2nd Splice Edge 55 : Splice rib 56 : Slit 57: Slit end 58: Arm section 59 : Mounting element 7 : Fastener 9 : Drum shaft 105 : Alternative underlay 150: Underlay body 106: Bridge part 205: Other alternative underlays 250: Underlay body 206: Bridge section 261: 1st floor 262: 2nd Floor 263: 3rd Floor 305: Other alternative underlays 351: First end 358: Arm section 359: Mounting element 401: Alternative tire molding drum 405: Other alternative underlay 407 : Fastener 410 : Drum body 412 : Home A : Axial B: Bead C: Circumference D: Arm direction E: Elasticity H1: First thickness H2: Second thickness L: Length R: Radial direction S: Drum axle T: Tire component

Claims

Claim 1 A tire forming drum comprises a drum body rotatable about a drum axis, an inflatable turn-up bladder extending circumferentially about the drum axis around the drum body to turn up a tire component supported by the turn-up bladder, and a plurality of pressing arms distributed circumferentially around the drum body, the plurality of pressing arms positioned between the drum body and the turn-up bladder to press the turn-up bladder while turning up the tire component, wherein the tire forming drum comprises a plurality of hinges for hingeably connecting the pressing arms to the drum body, and when the turn-up bladder is not inflated, the plurality of hinges are located below the turn-up bladder, and the tire forming drum comprises an underlay extending radially between at least one of the plurality of hinges and the turn-up bladder, sliding over the pressing arms and perpendicular to the drum axis. A tire forming drum that is prepared. Claim 2 A tire forming drum according to claim 1, wherein the underlay has a first end portion fixed to the drum body on the side opposite to the side where the plurality of pressing arms are located with respect to the plurality of hinges. Claim 3 A tire forming drum according to claim 1, wherein the drum body comprises a bead-lock section, and the underlay has a first end fixed to the drum body on the side facing the bead-lock section at a plurality of hinges. Claim 4 A tire forming drum according to claim 2 or 3, wherein the underlay has a second end opposite to the first end, and the second end is placed on at least one of a plurality of pressing arms. Claim 5 In paragraph 4, the second end is a tire forming drum that is free, unfixed, and unconstrained to slide over the at least one pressing arm in an arm direction parallel to the at least one pressing arm. Claim 6 In paragraph 4, the tire forming drum wherein the underlay is at least partially deformable from a cylindrical configuration to a conical configuration. Claim 7 A tire forming drum according to claim 1, wherein the underlay comprises an underlay body that is annular at a first end and divided into a plurality of arm sections at a second end opposite to the first end. Claim 8 A tire forming drum according to claim 7, wherein each arm section of a plurality of arm sections is configured to extend along each pressing arm of a plurality of pressing arms and be placed on each pressing arm. Claim 9 In claim 7, the underlay body is a tire forming drum that is deformable from a cylindrical configuration to a conical configuration in a plurality of arm sections. Claim 10 A tire forming drum according to claim 9, wherein the underlay body is provided with a plurality of slits that divide the underlay body into a plurality of arm sections. Claim 11 A tire forming drum in which, in the cylindrical configuration of the underlay body in item 10, a plurality of slits extend parallel to each other. Claim 12 A tire forming drum according to claim 10, wherein a plurality of slits extend over at least half the length of the underlay body between the first end and the second end. Claim 13 A tire forming drum according to claim 7, wherein the underlay body comprises a plurality of bridge portions, each bridge portion of the plurality of bridge portions interconnects a pair of arm sections of a plurality of arm sections at a first end, and each bridge portion has a circumferential elasticity greater than the circumferential elasticity of each pair of interconnected arm sections. Claim 14 In claim 13, the tire forming drum wherein the underlay body has a first thickness in a plurality of arm sections and a second thickness smaller than the first thickness in a plurality of bridge sections. Claim 15 In paragraph 13, the tire forming drum wherein the underlay body comprises a material different from the arm section in a plurality of bridge portions. Claim 16 In paragraph 13, the tire forming drum wherein the underlay body comprises a different layer configuration relative to a plurality of arm sections in a plurality of bridge portions. Claim 17 A tire forming drum according to claim 13, wherein the underlay body comprises a laminate of a first layer having a first elasticity and a second layer having a second elasticity greater than the first elasticity, wherein the second layer is covered by the first layer in a plurality of arm sections and is exposed in a plurality of bridge sections. Claim 18 In claim 7, the tire forming drum wherein the underlay body is spliced ​​in an annular configuration at the first end. Claim 19 A tire forming drum according to paragraph 2, wherein the underlay comprises a plurality of arm sections extending individually from a first end toward a second end opposite the first end. Claim 20 A tire forming drum according to claim 19, wherein each arm section of a plurality of arm sections is configured to extend along each pressing arm of a plurality of pressing arms and be placed on each pressing arm. Claim 21 A tire forming drum according to claim 1, wherein the underlay has a first end portion fixed to the drum body by one or more fasteners. Claim 22 A tire forming drum according to claim 21, wherein the one or more fasteners comprise a group of fasteners including pins, bolts, clamps, or ridges. Claim 23 A method for turning up a tire component using a tire forming drum according to claim 1, comprising: - providing the underlay radially between at least one hinge and the turn-up bladder; and - supporting the turn-up bladder on the underlay at at least one hinge while turning up the tire component.

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