Tooling with a receiving surface comprising a plurality of passages for manufacturing a molded object on the receiving surface

Abstract

The invention relates to a method and a tooling (1) for manufacturing an object (100), such as a toroidal tire (100), by molding, the tooling (1) having a receiving surface (10_out) for receiving the components (C1, C2, C3) of the object (100), the receiving surface (10_out) being provided with orifices (15) that form grooves (15), the tooling (1) further comprising an anti-penetration system (30) comprising an injection system and a feed circuit for injecting a pressurized fluid into the grooves (15) during a step of curing the tire (100) in order to limit the penetration into the grooves (15) of material of the components (C1, C2, C3) placed on the receiving surface and overflowing from the molding cavity defined by the tooling (1).

Description

[0001] DESCRIPTION

[0002] TITLE: Tooling with a receiving surface comprising a plurality of passages for the manufacture of an object molded on said receiving surface.

[0003] Technical field of the invention

[0004] The present invention relates to the general field of manufacturing an object molded on a receiving surface of a tool.

[0005] More particularly, the tool receiving surface is perforated and comprises a plurality of passages or orifices.

[0006] According to a particular application, the invention relates to the field of manufacturing toroidal tires, and more particularly pneumatic tires intended to equip the wheels of a vehicle.

[0007] By "tire" is meant a bandage intended to form a cavity by cooperating with a mounting support, for example a rim, this cavity being capable of being pressurized to a pressure higher than atmospheric pressure. A tire according to the invention has a structure of substantially toroidal shape of revolution around a main axis of the tire, this main axis being coincident with the axis of rotation of the tire.

[0008] State of the prior art

[0009] Generally speaking, a tire comprises a crown having two axial ends each extended, radially inwards, by a sidewall then by a bead intended to come into contact with a rim. The assembly delimits an internal toric cavity.

[0010] More precisely, the crown comprises, radially from the outside to the inside, a tread, intended to come into contact with the ground via a rolling surface, and a crown reinforcement intended to ensure the reinforcement of the crown of the tire. A carcass reinforcement connects the two sidewalls together and is anchored, in each bead, to a circumferential reinforcement element, most often of the bead type.

[0011] In order to improve the behavior, in particular the drift resistance, of the pneumatic tires, the Applicant had the idea of ​​implanting a stiffening structure within the toric inflation cavity that delimits the tire.

[0012] In this regard, reference may be made to documents WO 2019 / 1 15917 - Al and WO 2020 / 128225 - A l.

[0013] The tire described in these documents comprises a crown extended radially inwards respectively on each side of the median plane of the tire by first and second sidewalls then by first and second beads intended to come into contact with a mounting support, for example a rim. Each first and second bead comprises a circumferential reinforcing element intended to allow the tire to be attached to the mounting support.

[0014] The tire includes an internal surface delimiting a toric cavity for inflating the tire once the latter is mounted on the mounting support.

[0015] The tire described in these documents comprises a stiffening structure comprising first stiffening wire elements extending continuously in the toric cavity from the first bead to the crown and second stiffening wire elements extending continuously in the toric cavity from the second bead to the crown.

[0016] Each first and second wire stiffening element is secured to each bead from which it extends by a bead interface between the wire stiffening element and a portion of the inner surface of the bead. Similarly, each first and second wire stiffening element is secured to the crown of the tire by a crown interface between the wire stiffening element and a portion of the inner surface of the crown.

[0017] These stiffening wire elements are usually called "stays". The advantage of using stiffening wire elements is to have a stiffening structure with low mass and low hysteresis. The use of identical stiffening wire elements allows for a homogeneous distribution of forces between the stiffening elements.

[0018] However, in order to produce such cable-stayed bandages, the Applicant has developed specific manufacturing tools.

[0019] In this regard, reference may be made to document FR 3 120 814 - Al which proposes a grooved core tool for the manufacture of pneumatic tires reinforced by stays which pass through the inflation cavity.

[0020] The tooling described in this document comprises a core provided with groove-type passages intended to receive reinforcing elements, called "stays" which are designed to permanently integrate the structure of the bandage and each extend into the cavity of the bandage by connecting a top anchoring point located in the top of the bandage to a lateral anchoring point located in one of the sides or beads of the bandage.

[0021] The use of such a core makes it possible to position the stays at the desired locations within the volume reserved by the core and consequently in the region of space which will subsequently become the cavity of the bandage after the said bandage has been formed and the core removed.

[0022] However, during the bandage curing step, during which the components of the wall of said bandage are vulcanized, the bandage is inserted into the grooves of the core when the pressure increases in the curing mold.

[0023] The internal volume of the curing mold available to house the tire then becomes larger than desired, the tire therefore has more room to expand freely and the internal pressure in the curing mold cannot reach the pressure necessary for manufacturing the tire.

[0024] In fact, the molding pressure is obtained by expansion of the core of the manufacturing tool and the bandage during the cooking stage.

[0025] It is therefore essential that the volume of the bandage is perfectly adapted to the volume of the baking mold in order to achieve a necessary molding pressure of between 50 bars and 60 bars, preferably equal to 55 bars. Without such a molding pressure, the bandage is not pressed against the mold and may have appearance defects. Furthermore, the individual bandage segments will not be sufficiently brought into contact with each other, so that the adhesion between the bandage segments may prove insufficient.

[0026] In addition, tire calls inside the grooves can cause aesthetic problems inside the casing, but also structural problems, such as the displacement of the carcass threads.

[0027] Document FR 3 120 814 - Al proposes a solution to plug the grooves with mechanical devices. However, such a solution is difficult to apply industrially.

[0028] There is a need to remedy the aforementioned drawbacks and to improve existing solutions to prevent the penetration of the rubber constituting the bandage into the grooves of a grooved core of a tool for manufacturing a strut tire.

[0029] Statement of the invention

[0030] The invention aims to prevent the materials constituting the object from flowing into the passages made in a tool comprising an openwork receiving surface.

[0031] More particularly, the invention also aims to prevent the components constituting the raw bandage or the rubber from creeping into the grooves of the molding inner part, called "PIM" or core of the tire.

[0032] The invention relates to a tool intended for the manufacture of an object comprising a wall having an internal surface which delimits a cavity, the tool comprising a receiving surface having a shape conjugated to the internal surface of the wall of the object and comprising a plurality of passages which extend under the receiving surface, and which open onto said receiving surface, the object being intended to be molded on the receiving surface of the tool.

[0033] The tooling comprises an anti-penetration system configured to control the creep of the material constituting the object in the passages, the anti-penetration system comprising a circuit for supplying a fluid under pressure into the passages and a system for injecting said fluid under pressure during a step of cooking the object.

[0034] Such tooling makes it possible to mold objects on receiving surfaces or molding surfaces comprising passages or orifices.

[0035] According to a particular embodiment of the invention, the object is a toroidal bandage of a tire forming the object and the tooling is configured to manufacture said toroidal bandage.

[0036] According to one embodiment, the toroidal bandage comprises a crown intended to form a tread, a first annular bead and a second annular bead designed to allow the bandage to be attached to a mounting support, such as a rim, as well as a first sidewall and a second sidewall which connect the crown respectively to the first bead and to the second bead, the crown, the first and second sidewalls and the first and second beads forming as a whole a wall having a concave internal surface which delimits a cavity of the bandage.

[0037] Said tooling comprises a toroidal core having, around its central axis, a convex external surface called the "receiving surface" which has a shape conjugated to the internal surface of the wall of the bandage and which comprises for this purpose a radially external top zone, intended to receive components constituting the top of the bandage, and, on either side axially of said top zone, a first lateral zone folded towards the central axis and intended to receive components constituting the first flank and the first bead as well as a second lateral zone folded towards the central axis and intended to receive components constituting the second flank and the second bead, so that the core materializes a volume, called the "reserved volume", which is delimited externally by the receiving surface and which corresponds to the cavity of the bandage.

[0038] The core comprises a plurality of passages which extend inside the reserved volume, under the receiving surface, and which open onto said receiving surface in such a way that each of said passages connects the top zone of the receiving surface to one of the first and second lateral zones so that the core can receive, inside said passages, reinforcing elements, called "stays", which are designed to permanently integrate the structure of the bandage and each extend into the cavity of the bandage by connecting a top anchoring point located in the top of the bandage to a lateral anchoring point located in one of the flanks or beads of the bandage.

[0039] The tooling includes an anti-penetration system which cooperates with the core to prevent penetration of the components constituting the crown, sides or beads of the bandage into the passages of the core in which the stays are engaged.

[0040] The anti-penetration system comprising a circuit for supplying a pressurized fluid into the passages of the core and a system for injecting said pressurized fluid during a bandage curing step.

[0041] The anti-penetration system prevents materials, and in particular rubber-based compositions, present in the components of the bandage from penetrating into the grooves by creep, in order to prevent the formation of rubber burrs which would stick the stays to the walls of the grooves, and which would therefore create a risk of tearing off the stays when the angular sectors of the core are extracted.

[0042] The injection under pressure of a fluid into the grooves makes it possible to prevent, or significantly slow down, the penetration into the groove of the constituent materials of the components of the bandage, and in particular of mixtures based on unvulcanized rubber.

[0043] When curing on a hard core of the manufacturing tool, the molding pressure is obtained by the difference between the molding volume and the contained tire components. This balance changes according to expansions. In practice, the increase in temperature of the molding inner part and the tire components causes an increase in pressure. Leaks from the tire components through the vents moderate this increase in pressure, but the grooves in the stays offer openings that are too large and the resulting loss of volume causes the pressure to drop. To maintain the pressure at a level that meets the curing requirements, it is then essential to inject a fluid into the grooves, at a pressure that reaches a pressure between 35 bars and 80 bars, preferably between 50 bars and 70 bars, more preferably between 50 bars and 55 bars.Said fluid pressure preferably increases progressively, for example linearly, according to a first slope, for a first duration of between 50s and 100s, for example equal to 60s, to reach a first, intermediate pressure of between 20 bars and 35 bars then following a second slope for a second duration of between 120s and 200s, for example equal to 150s, to reach a molding pressure of between 35 bars and 80 bars, preferably between 50 bars and 70 bars, preferably between 50 bars and 55 bars.

[0044] As soon as the mold is closed, a volume of the bandage components penetrates the grooves and forms a plug, at the same time the injection of pressurized fluid begins to contain the penetration of the bandage components into said grooves. The progressive control of the increase in pressure of the pressurized fluid associated with the plug effect prevents a leak of pressurized fluid between the molding inner part and the Raw. This control also allows time for the bandage components to penetrate the reinforcements and compact, this prevents the appearance of blowholes at the exit of the mold, after curing.

[0045] Advantageously, the passages for stay cables are formed by grooves, preferably blind, which are hollowed out from the receiving surface in the thickness of the reserved volume so as to present a continuous opening along the profile of the receiving surface, from the top zone to the lateral zone concerned.

[0046] According to one embodiment, the core comprises an assembly of several single-piece angular sectors arranged in azimuth around the central axis of the tool, according to an alternation of sectors called "keys", preferably designed to be accessible by radially internal approach and to be removed first during disassembly of the core, and sectors called "vaults", supported and locked in position by the keys, and preferably designed to become maneuverable after they have been released by the removal of the keys. The vaults form sectors complementary to the keys.

[0047] Such an arrangement in single-piece sectors will facilitate demolding, and will also allow the stays to be passed locally on the radially external side of the core, on the receiving surface which will receive the components of the wall of the bandage, which will allow the corresponding portion of the stays to be easily integrated into the wall and therefore ensure the anchoring of said stays in the top of the bandage.

[0048] Preferably, each key or key segment and each vault or vault segment comprises its own pressurized fluid supply circuit. Thus, a separate injection can be carried out in each key and vault segment.

[0049] For example, each key comprises a plurality of key grooves distributed, preferably equally distributed, in azimuth around the central axis according to an angular repetition pitch, the key grooves being, for example, generated along radial planes containing the central axis.

[0050] Preferably, each key comprises a housing extending radially from a radially internal surface radially outwards, without opening onto the receiving surface, the fluid supply circuit comprises two main key conduits originating in the corresponding supply housing and extending axially respectively towards the lateral zones and two secondary key conduits extending circumferentially from the end of each main conduit in the corresponding key, the secondary key conduits of the corresponding key connecting the key grooves made in the corresponding key.

[0051] For example, each vault comprises a plurality of vault grooves distributed, preferably equally distributed, around the central axis at an angle of inclination forming a non-zero angle relative to a radial axis.

[0052] For example, vault grooves are generated along planes inclined relative to the radial planes containing the central axis.

[0053] Preferably, each vault comprises a housing extending radially from a radially internal surface radially outwards, without opening onto the receiving surface, the fluid supply circuit comprises two main vault conduits originating in the corresponding supply housing and extending axially respectively towards the lateral zones and two secondary vault conduits extending circumferentially from the end of each main conduit in the corresponding vault, the secondary vault conduits of the corresponding vault connecting the vault grooves made in the corresponding vault.

[0054] Advantageously, the vault grooves are not parallel to the key grooves.

[0055] Such an arrangement makes it possible to improve the extraction of the core from the bandage after the cooking step.

[0056] Generally, the grooves are arranged at a variable angle of inclination which depends on the size of the core.

[0057] Alternatively, one could provide that the grooves are all identical and inclined in the same direction.

[0058] The groove is understood to mean the set comprising the key grooves and the vault grooves.

[0059] According to one embodiment, each key comprises two opposite lateral faces forming joint planes of said key with the two vaults adjacent to said key, said lateral faces being inclined according to two slopes forming a V or chevron relative to each other and relative to the sagittal meridian plane of the key considered.

[0060] Alternatively, said lateral faces may be parallel to each other and to the sagittal meridian plane, as described in patent FR 3 120 814 - A1.

[0061] According to one embodiment, each vault comprises two opposite lateral faces forming joint planes of said vault with the two keys adjacent to said vault, said lateral faces being inclined according to two slopes forming an inverted V or inverted chevron relative to each other and relative to the sagittal meridian plane of the vault considered.

[0062] Advantageously, each keystone and vault is delimited by a lateral flank each having, in section in a radial plane, a curved, convex external profile, which ensures a curved transition between the top zone and the corresponding lateral zone of the receiving surface, and the curvature of which matches the curvature of the hollow of the cavity of the bandage, and more particularly the curvature of the internal surface of the wall of the bandage at the transition between the top and the flank, as well as in the zones where the wall draws the axially most external points of the flanks. In this way, the lateral flanks of the keystones and vaults each form a lobe which can occupy, temporarily fill and therefore conform, the hollow of the cavity of the bandage, during the manufacture of said bandage.

[0063] It should be noted in this respect that, due to the concavity of the cavity and the axial tightening formed by the ridges in relation to the flanks, said ridges are located radially in line with the lateral flanks of the keystones and vaults.

[0064] Preferably, the fluid used is selected from the group comprising nitrogen, helium, argon, carbon dioxide, any inert gas. Alternatively, the fluid used could be water. However, a gas has the advantage of not leaving a deposit.

[0065] According to a second aspect, the invention relates to a method of manufacturing by molding an object comprising a wall having an internal surface which delimits a cavity, the tooling comprising a receiving surface having a shape conjugated to the internal surface of the wall of the object and comprising a plurality of passages which extend under the receiving surface, and which open onto said receiving surface.

[0066] The object being intended to be molded on the receiving surface of the tool.

[0067] The tooling comprises an anti-penetration system configured to control the creep of the material constituting the object in the passages, the anti-penetration system comprising a circuit for supplying a fluid under pressure into the passages and a system for injecting said fluid under pressure during a step of cooking the object.

[0068] Said method comprises:

[0069] - a preparation stage, during which tools are prepared as described previously;

[0070] - a filling step during which the constituent materials of the object are deposited on the receiving surface of the tool, in order to construct the wall of the object,

[0071] - a cooking step; and

[0072] - a step of demolding the object. During the cooking step, the method comprises a step of supporting the pressure increase, during which a pressurized fluid is injected into the tool in order to temporarily fill, at least during the cooking step, the volume of each passage.

[0073] According to a particular embodiment of the invention, the subject is a toroidal bandage of a tire comprising a crown intended to form a tread, a first annular bead and a second annular bead designed to allow the bandage to be attached to a mounting support such as a rim, as well as a first sidewall and a second sidewall which connect the crown respectively to the first bead and to the second bead, the crown, the first and second sidewalls and the first and second beads forming as a whole a wall having a concave internal surface which delimits a cavity of the bandage.

[0074] Said bandage comprising reinforcing elements, called "stays", which each extend into the cavity of the bandage by connecting a top anchoring point located in the top of the bandage to a lateral anchoring point located in one of the sides or beads of the bandage.

[0075] Said method comprises:

[0076] - a preparation stage, during which tools are prepared as described previously;

[0077] - a pre-filling step during which anchoring structures are placed on the lateral zones and on the top zone of the receiving surface of the core, opposite the anchoring points provided for attaching the reinforcements to the wall of the bandage, which are designed to collect the ends of the reinforcements which emerge from the passages of the core and to adhere to the constituent components of the flanks or the beads, respectively to the constituent components of the crown, by sandwiching said ends of the reinforcements between the anchoring structures and said components, in order to ensure the fixing of the reinforcements to the anchoring points provided;

[0078] - a reinforcement installation step, during which a reinforcement wire, intended to form a stay, is passed through each passage of the core, preferably using a continuous reinforcement wire which is arranged in a serpentine fashion through the successive passages by making said continuous reinforcement wire go and return in one piece from one lateral zone of the core to the other lateral zone via the top zone,

[0079] - a filling step during which the components constituting the crown, the sides and the beads of the bandage are deposited on the receiving surface, in order to construct the wall of the bandage, preferably by winding said components onto the rotating core, in order to construct the wall of the bandage,

[0080] - a cooking step; and

[0081] - a demolding step during which the core of the bandage is removed, leaving the reinforcements in place in the cavity of said bandage.

[0082] During the pressure build-up support step, a pressurized fluid is injected into the core in order to temporarily fill, at least during the cooking step, the volume of each passage which is left free between the reinforcing element engaged in said passage and the opening(s) of the passage which open onto the receiving surface.

[0083] Thus, during the pressure build-up support stage, the anti-penetration system is implemented which, during the curing stage, cooperates with the core to prevent penetration of the constituent components of the crown, sides or beads of the bandage into the grooves of the core in which the reinforcements are engaged.

[0084] During the curing step, the core and the raw bandage carried by said core are placed in a curing mold, in order to vulcanize the components of the rubber-based bandage. For this purpose, the temperature of the mold, and more particularly of the bandage, will preferably be brought to a value between 120°C and 200°C.

[0085] It is the gas pressure which, by opposing the creep of the material, here the rubber-based material, into the grooves, and therefore by limiting the penetration of said material into the grooves, has the effect of substantially blocking the components constituting the bandage outside the grooves, and effectively gives the molding pressure.

[0086] Without the injection of pressurized gas during the curing stage, the components of the raw bandage would penetrate and flow in too large a quantity into the grooves, so that the necessary molding pressure, here between 50 bars and 60 bars, preferably equal to 55 bars, could not be reached.

[0087] Such a solution, which uses pressurized gas to limit the creep of the tire components in the grooves, advantageously does not require interrupting the manufacturing process to install a mechanical groove sealing device. There is also no material to remove after dismantling the core.

[0088] According to one embodiment, the core comprises an assembly of several single-piece angular sectors arranged in azimuth around a central axis of the tool, according to an alternation of sectors called "keys", and sectors called "vaults", supported and locked in position by the keys, the vaults forming sectors complementary to the keys and each key or key segment and each vault or vault segment comprising its own circuit for supplying the pressurized fluid.

[0089] More specifically, during the said preparation stage, the key and vault segments will be assembled to form the core.

[0090] During the pressure build-up support stage, the pressurized fluid is injected into the supply circuit of each key and each vault.

[0091] This allows for a separate injection into each keystone and vault segment.

[0092] Advantageously, the fluid is injected at a pressure which increases progressively, here preferably linearly, until reaching a pressure of between 35 bars and 80 bars, preferably between 50 bars and 70 bars, more preferably which increases according to a first slope for a first duration of between 50s and 100s, for example equal to 60s, linearly, to reach a first pressure of between 20 bars and 35 bars, then following a second slope for a second duration of between 120s and 200s, for example equal to 150s, to reach a molding pressure of between 35 bars and 80 bars, preferably between 50 bars and 70 bars, preferably between 50 bars and 55 bars. For example, the duration of the curing step is between 500s and 800s at a temperature of between 150°C and 200°C, preferably 170°C.

[0093] Advantageously, the injection of the pressurized gas carried out at the pressure build-up support stage starts directly or after the mold has closed.

[0094] The injection of pressurized fluid at a low pressure initially has the effect of allowing a small quantity of the components forming the bandage to penetrate into the grooves in order to ensure a seal between the core and the green bandage, allowing the pressurized fluid to be contained in the grooves without leakage into the bandage.

[0095] Brief description of the drawings

[0096] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0097] [Fig. 1A] illustrates a sectional view in a radial plane of an example of a braced bandage produced according to the invention;

[0098] [Fig. 1 B] illustrates a partial perspective view of the guyed bandage of Figure 1A;

[0099] [Fig.2A], [Fig.2B] illustrate, in respectively exploded and assembled perspective views, an annular subassembly forming a core of a tool according to the invention, said being angularly subdivided into sectors, which alternately form sectors called “vaults” and sectors called “keys” designed to lock the vaults in position; said sectors being each intended to receive the constituent components of a tire sidewall and which contain passages for the stays;

[0100] [Fig.3] is a detail view in section in a radial plane of the tooling illustrated in Figure 2B;

[0101] [Fig.4A], [Fig.4B] illustrate in detail in perspective, respectively full and in section of a key of the core of the tool of figures 2A and 2B; [Fig.5A], [Fig.5B] illustrate in detail in perspective, respectively full and in section of a vault of the core of the tool of figures 2A and 2B;

[0102] [Fig.6] illustrates, according to a detailed sectional view in a meridian plane passing through the middle of the grooves, of the core of the tooling of figures 2A and 2B, the installation of the stays within said core, before the production of the wall of the bandage;

[0103] [Fig.7] represents a cooking step during the tire manufacturing process;

[0104] [Fig.8] represents a flowchart of a manufacturing process for a strut tire with the tooling of Figures 2A to 6;

[0105] [Fig.9] represents an example of a pressure rise curve of the fluid to be injected during the pressure rise support step; and

[0106] [Fig. 10] illustrates an example of the construction of the keystones and vaults of the tooling of figures 2A and 2B.

[0107] [Fig. 1 1] illustrates, in a perspective view, an alternative embodiment of a toroidal molding core according to the invention comprising orifices formed by grooves which extend along radial planes containing the central axis of the core, grooves which here each extend continuously over the first lateral zone and as far as the second lateral zone passing through the top zone of said core.

[0108] [Fig. 12] is a sectional view of the core of Figure 11, in a radial plane containing the central axis of said core, thus showing one of the grooves as well as the conduits of the injection system which supply said groove with pressurized fluid during the cooking step.

[0109] [Fig. 13] illustrates, in a perspective view, an alternative embodiment of a toroidal molding core according to the invention comprising orifices formed by grooves which extend circumferentially around the central axis of said core; this alternative has several distinct circumferential grooves, parallel to each other, and which open for some on the top zone of the core, and for others on the first and second lateral zone, as well as, here, at the level of the shoulders formed at the transition between the top zone and the lateral zones of the core.

[0110] [Fig. 14] is a sectional view of the core of Figure 13, in a radial plane containing the central axis of said core, thus showing in section the different grooves as well as the conduits of the injection system which supply said grooves with pressurized fluid during the cooking step.

[0111] [Fig. 15] illustrates, in a perspective view, another alternative embodiment of a toroidal molding core according to the invention comprising orifices formed by grooves which extend circumferentially around the central axis of said core; this alternative has several distinct circumferential grooves, oriented along planes normal to the central axis of the core, and therefore parallel to each other, and which this time all open onto the top zone of the core.

[0112] [Fig. 16] is a sectional view of the core of Figure 15, in a radial plane containing the central axis of said core, thus showing in section the different grooves of the summit zone as well as the conduits of the injection system which supply said grooves with pressurized fluid during the cooking step.

[0113] [Fig. 17] illustrates, according to a schematic detail view in section in a radial plane containing the central axis, the phenomenon of penetration of material into an orifice, such as a groove in the core of figures 15 and 16, and therefore the phenomenon of plug formation, against the pressure of the fluid, which occurs during the cooking step.

[0114] [Fig. 18] illustrates, in a schematic view, a tool variant having at least one orifice forming a groove which draws a sinusoidal path on the receiving surface.

[0115] Detailed description of at least one embodiment

[0116] Figures 2A, 2B and 3 illustrate a tool 1 intended for the manufacture of a toroidal bandage 100, as illustrated in Figures 1A and 1B. More generally, the tool 1 could be intended for the manufacture of any object intended to be molded on a molding surface of the tool comprising a plurality of passages or orifices.

[0117] Such a bandage 100 preferably constitutes a pneumatic bandage intended to equip a wheel of a vehicle, to ensure the connection of said vehicle with the ground.

[0118] The bandage 100 has a shape of revolution around an axis called the “central axis” XI-XI which corresponds substantially, in practice, to the axis of rotation of the wheel.

[0119] This central axis Xl -Xl defines three directions conventionally used by those skilled in the art: an axial direction, a radial direction and a circumferential direction.

[0120] By "axial direction" is meant a direction collinear with the central axis X l -Xl of the tire 100, that is to say collinear with the axis of rotation of the tire 100.

[0121] By "radial direction" is meant a direction which extends along a radius of the tire 100, that is to say any direction which is secant and perpendicular to the central axis Xl -Xl.

[0122] By "circumferential direction" is meant a direction which is perpendicular to both the axial direction and a radius of the tire 100, and which corresponds, in a plane normal to the central axis Xl -Xl, to the tangent to a circle whose center is on the axis of rotation of the tire 100.

[0123] The bandage 100 comprises, in a manner known per se, a crown 101 intended to form a tread, a first annular bead 102 and a second annular bead 103 designed to allow the bandage 100 to be attached to a mounting support, such as a rim.

[0124] The bandage 100 further comprises a first flank 104 and a second flank 105 which connect the crown 101 respectively to the first bead 102 and to the second bead 103.

[0125] By simple convention, we can consider that, in a meridian plane P =Sea, the limit between the vertex 101 and the flank 104, 105 considered corresponds to the axially outermost point of the external surface of the bandage 100 for which the angle between the tangent to the external surface of the bandage 100 and a straight line parallel to the central axis Xl -Xl is equal to 30°.

[0126] By "meridian plane" P = Mer, or radial plane, means a plane parallel to, and containing, the central axis Xl -Xl . Such a meridian plane is normal to the circumferential direction.

[0127] By "equatorial plane" P = Eq, we mean a plane normal to the central axis Xl -Xl and which passes through the radially outermost point of the bandage, which is, preferably, located axially midway between the axially outermost points of the bandage 100.

[0128] The said equatorial plane P =Eq therefore axially divides the bandage 100 into two toroidal halves, preferably substantially equal, called, by analogy with the terrestrial globe, “hemispheres”.

[0129] The crown 101, the first and second flanks 104, 105 and the first and second beads 102, 103 form as a whole a wall 106 having a concave internal surface 106_in which delimits an internal cavity 107 of the bandage 100.

[0130] In practice, the internal cavity 107 of the tire 100 is toroidal, and advantageously forms the inflation cavity of the tire 100, which is intended to receive a pressurized fluid, such as air, to support the crown 101 of the pneumatic tire 100 relative to the rim.

[0131] Preferably, as can be seen in Figures 1A and 1B, each bead 102, 103 is located axially set back from the axially most protruding position of the corresponding flank 104, 105, i.e. the bead 102, 103 is closer to the equatorial plane P = Eq that the flank 104, 105 to which said bead is connected. Thus, the flank 104, 105 forms, between the apex 101 and the corresponding bead 102, 103, in section in the meridian plane P = Sea, a profile generally curved outwards and the end of which forming the bead 102, 103 is axially re-entrant, so that the cavity 107 has, in section in said meridian plane, substantially a Q shape (capital Omega).

[0132] The bandage 100 comprises reinforcing elements 108, called “stays”, designed to permanently integrate the structure of the bandage 100 and extend into the internal cavity 107 of said bandage by connecting a top anchoring point 109 located at the top 101 of the bandage 100 to a lateral anchoring point 110 located in one of the flanks 104, 105 or the beads 102, 103 of the bandage 100.

[0133] As illustrated in Figures 1A, 1B, the top 109 and lateral 110 anchoring points of each stay 108 are located at the same azimuth around the central axis Xl-Xl of the bandage 100, so that the stays 108 extend along radial planes containing the central axis Xl-Xl of the bandage 100.

[0134] The shrouds 108 may represent different configurations, including a variety of orientations, without departing from the scope of the invention.

[0135] Each stay 108 is preferably contained within a single hemisphere, in that no stay 108 crosses the equatorial plane P = Eq inside the internal cavity 107 of the bandage 100.

[0136] Each stay 108 is intended to work in traction and therefore to connect the top anchoring point 109 to the corresponding lateral anchoring point 110 along a straight line segment, that is to say by geometrically forming a taut or quasi-taut cord, under the arc which is formed by the internal surface 106_in of the wall 106 between the top anchoring point 109 and the lateral anchoring point 110 in the bandage 100 at rest, and this so that the stay opposes the mutual distancing of said anchoring points 109, 110 relative to each other, and thus increases the lateral rigidity of the bandage 100.

[0137] The shrouds 108 are, as illustrated, distributed in azimuth around the central axis Xl -Xl, here, uniformly, according to a constant angular repetition pitch, for example between 0.5° and 5°.

[0138] Alternatively, another distribution of the stays 108 could be provided, as will be described with reference to the tool 1.

[0139] According to the invention, the tool 1 comprises a toroidal core 10 having, around its central axis X2-X2, an external surface 10 = out, called the receiving surface, which has a shape conjugated to the internal surface 106 = in of the wall 106 of the bandage 100.

[0140] The external surface 10 comprises a radially external top zone 11 intended to receive components constituting the crown 101 of the bandage 100, and, on either side axially of said top zone 11, a first lateral zone 12 folded towards the central axis X2-X2 of the core 10 and intended to receive components constituting the first flank 104 and the first bead 102, as well as a second lateral zone 13 intended to receive components constituting the second flank 105 and the second bead 103.

[0141] In this way, the core 10 materializes a volume, called “reserved”, which is delimited externally by the receiving surface 10 = out and which corresponds to the internal cavity 107 of the bandage 100.

[0142] The core 10 can thus occupy, and therefore temporarily reserve, during the manufacture of the bandage 100, the volume whose shape and dimensions correspond to the internal cavity 107, a volume which will become the internal cavity 107 of the bandage when the core 10 has been removed from said bandage 100, during the demolding operation which will complete the manufacturing cycle of the bandage 100.

[0143] It will be noted that, in practice, the central axis X2-X2 of the core 10, around which said core 10 forms a ring, will merge with the central axis Xl-Xl of the bandage 100 manufactured on the core 10. For convenience of description, one or the other can therefore be designated indifferently by the expression “central axis”.

[0144] As illustrated, the core 10 comprises a plurality of passages 15 which extend within the reserved volume, under the receiving surface 10. = out, and which open onto said receiving surface 10 =out such that each of said passages 15 connects the top zone 11 of the receiving surface 10 = out to one of the first and second lateral zones 12, 13 so that the core 10 can receive, inside said passages 15, the reinforcing elements 108 of the bandage 100.

[0145] The passages 15 thus correspond to empty spaces which are provided in the core 10, inside the reserved volume, to be able to accommodate the stays 108, and thus allow each stay 108 to cross the receiving surface 10. = out, a first time to enter the reserved volume, here through the lateral zone 12, 13, and a second time to exit the reserved volume, here in the summit zone 1 1, or vice versa.

[0146] Advantageously, whatever the configuration of the stays 108, the core 10 according to the invention makes it possible to install said stays 108 in the volume reserved by the core 10, and therefore in the space which will become the internal cavity 107 of the bandage 100, prior to the constitution of the bandage 100, according to a distribution and an arrangement which will correspond substantially, or even exactly, to the distribution and the arrangement which said stays 108 will have within the finished bandage 100, ready to be mounted on the rim, since the stays 108 remain in place inside the internal cavity 107, in the desired position, and secured to the bandage 100, when the core 10 is removed.

[0147] Thanks to the use of a core 10 according to the invention, it is therefore ensured that the bandage 100 will have a well-controlled and reproducible configuration from one bandage 100 to another.

[0148] Furthermore, since the stays 108 are thus sheltered in the passages 15 of the core 10 during the installation of the components constituting the wall 106 of the bandage 100, there is no risk of accidentally moving, tearing off or damaging said stays 108 during the manufacturing process of the wall 106 of the bandage 100.

[0149] In a particularly preferential manner, it will be possible to choose to arrange the passages 15 according to open demouldable shapes, allowing the production of a permanent, reusable core 10, which can be extracted from the bandage 100, after manufacture of said bandage 100, without damage to the stays 108, then reused to manufacture the next bandage.

[0150] For this purpose, the passages 15 for stays 108 will preferably be formed by grooves dug from the receiving surface 10 out into the thickness of the reserved volume so as to present a continuous opening along the profile of the receiving surface 10. = out, from the summit zone 1 1 to the lateral zone 12, 13 concerned.

[0151] Advantageously, since each groove 15 creates, at the level of the receiving surface 10 =out, a slot-like opening which extends over the entire length of the receiving surface l O out going from the lateral anchoring point 1 10 of the stay 108 concerned to the top anchoring point 109 of said stay 108, it is possible to engage the stay 108 in the passage 15 before the installation of the constituent components of the wall 106 of the bandage 100, simply by sliding said stay 108 into the corresponding groove 15, from the outside of the core 10, so that the stay 108 passes through the receiving surface l O out to sink into the reserved volume, in the direction of the central axis X2-X2 of the core 10.

[0152] Advantageously, after having placed on the receiving surface 10 =out, the constituent components of the wall 106 of the bandage 100, so that the wall 106 will cover the grooves 15, it will be possible to extract the core 10 from the inside of the bandage 100, by gradually removing the stays 108, now fixed to the wall 106 and therefore integrated into the bandage 100, through the openings of the grooves 15 of the core 10 which are released, and thus leaving the stays 108 in their final place in the internal cavity 107 of the bandage 100.

[0153] For convenience of description, and in order not to overload the figures, the same reference "15" will designate the passages for shrouds 108 and the grooves which constitute a specific preferred form of said passages for shrouds 108.

[0154] Preferably, the grooves 15 are blind, that is to say that the grooves 15 have a solid bottom 19, visible in FIG. 3, located under the receiving surface 10 =out, in the reserved volume and which extends from a first mouth of the groove 15, which opens onto the lateral zone 12, 13 of said receiving surface 10 out, to a second mouth of the groove 15, which opens onto the top zone 11 of said receiving surface 10 = out.

[0155] Thus, when the stay 108 is in place in the corresponding groove 15, said stay 108 is located radially, and more particularly is contained radially, relative to the central axis X2-X2 of the core 10, between the bottom and the opening of the groove 15 located on the receiving surface 10 = out.

[0156] The stay 108 can either be detached radially above the bottom of the groove 15, that is to say located at a non-zero radial distance from said bottom, beyond the bottom 19 relative to the central axis X2-X2, or rest in support on said bottom 19, which will then advantageously serve as a guide and support for said stay 108 during the manufacture of the bandage 100.

[0157] Preferably, the depth of the grooves 15, relative to the receiving surface 10 = out, and therefore more particularly the distance which separates the bottom 19 of the groove 15 from the receiving surface 10 = out, is sufficient so that each of said grooves 15 can allow the stay 108 to follow, within said groove 15, a path which directly connects the lateral anchoring point 110 to the summit anchoring point 109 along a straight line segment.

[0158] Thus, the stay 108 may possibly adopt its functional configuration within the groove 15, without interfering with or being deformed or deflected by said groove 15, functional configuration according to which said stay 108 forms a rope which connects by the shortest path the ends of the arc drawn by the wall 106 of the bandage 100 between the lateral anchoring point 110 and the top anchoring point 109, so that said stay 108 may, once the bandage 100 is released from the core 10, work effectively in traction, in the manner of a tie rod, between the lateral anchoring point 110 and the top anchoring point 109.

[0159] According to a preferred characteristic which can be applied whatever the nature and shape of the passages 15 for stays 108, but which is more particularly interesting in the cases where said passages 15 for stays are formed by grooves 15, the core 10 comprises, as is notably visible in FIGS. 2A and 2B, an assembly of several single-piece angular sectors arranged in azimuth around the central axis X2-X2, according to an alternation of sectors called "keys" 20, designed to be accessible by radially internal approach and to be removed first during disassembly of the core 10, and of sectors called "vaults" 21, supported and locked in position by the keys 20, and designed to become maneuverable after they have been released by the removal of the keys 20.

[0160] The number of keys 20, equal to the number of vaults 21, will be chosen to be sufficiently high to allow easy splitting and disassembly by centripetal radial extraction of said sectors 20, 21 constituting the core 20, and nevertheless sufficiently moderate so as not to unnecessarily multiply the sectors, and therefore to simplify the assembly of the core 20. As such, the number of keys 20, and therefore the number of vaults 21, will preferably be between 4 and 6, and more preferably equal to 5, as is the case in FIGS. 2A and 2B. For the sake of standardization and for ease of assembly, all the keys 20 will preferably be identical to each other, and therefore interchangeable. Likewise, all the vaults 21 will preferably be identical to each other, and therefore interchangeable.

[0161] Preferably, the lateral faces 20a, 20b which delimit each key 20 and which form the joint planes of said key 20 with the two vaults 21 adjacent to said key 20, are here inclined according to two slopes forming a V or chevron relative to each other and relative to the sagittal meridian plane of the key 20 considered.

[0162] Alternatively, said lateral faces may be parallel to each other and to the sagittal meridian plane, as described in patent FR 3 120 814 - A1.

[0163] The vaults 21 will of course form sectors complementary to the keys 20, and will be locked in position by said keys 20 within the core 20.

[0164] The lateral faces 21a, 21b which delimit each vault 21 and which form the joint planes of said vault 21 with the two keys 20 adjacent to said vault 21, will be inclined according to two slopes forming an inverted V or inverted chevron relative to each other and relative to the sagittal meridian plane of the vault 21 considered.

[0165] By analogy with the architectural field, the keys 20, moreover positioned and maintained by a common annular support 22, will therefore prevent the collapse of the vaults 21, and more generally of the arch formed by the succession of said keys 20 and vaults 21. This support provided by the keys 20 will be all the more robust and stable as the clearance angle of the lateral faces of the keys 20 is high.

[0166] To dismantle the core 20 and extract it from the bandage 100 during the demolding operation, we will therefore start by extracting the keys 20, according to a centripetal radial extraction movement, followed by an axial release movement, which will have the effect of releasing the vaults 21, which will then be extracted in turn by a centripetal radial extraction movement, then an axial release movement.

[0167] Alternatively, it could be provided that the core 10 does not comprise a plurality of single-piece angular sectors but a central crown on which left and right ears are mounted, as described in patent FR 3 120 814 - A1.

[0168] Advantageously, such an arrangement in single-piece sectors will facilitate demolding, and will also allow the stays 108 to pass locally on the radially external side of the core 10, on the receiving surface 10 =out which will receive the components of the wall 106 of the bandage, which will make it possible to easily integrate the corresponding portion of the stays 108 into the wall 106 and therefore to ensure the anchoring of said stays in the top 101 of the bandage 100.

[0169] Preferably, the top portion of the core 10 forms a right cylinder, with a circular base, centered on the central axis X2-X2.

[0170] Furthermore, preferably, the equatorial plane P = EQ is contained in the axial range covered by the central portion of the summit zone 1 1 of the core 10, and more particularly is located in the middle of said axial range, so as to subdivide the summit zone 1 1 into two parts which are equal, or even symmetrical to each other, with respect to said equatorial plane P_EQ.

[0171] Each key 20 and vault 21 is delimited by a lateral flank 20c, 20d, 21c, 21d each having, in section in a radial plane, a curved, convex external profile, which ensures a curved transition between the summit zone 11 and the corresponding lateral zone 12, 13 of the receiving surface 10. = out, and whose curvature matches the curvature of the hollow of the cavity 107 of the bandage 100, and more particularly the curvature of the internal surface 106 = in the wall 106 of the bandage at the transition between the top 101 and the flank 104, 105, as well as in the areas where the wall 106 draws the axially outermost points of the flanks 104, 105.

[0172] In this way, the lateral flanks 20c, 20d, 21c, 21d of the keys 20 and vaults 21 each form a lobe which can occupy, temporarily fill and therefore conform, the hollow of the cavity 107 of the bandage 100, during the manufacture of said bandage 100.

[0173] It will be noted in this respect that, due to the concavity of the cavity 107 and the axial tightening formed by the beads 102, 103 relative to the flanks 104, 105, said beads 102, 103 are located radially in line with the lateral flanks 20c, 20d, 21c, 21d of the keys 20 and vaults 21.

[0174] The angular segments 20, 21 forming the core 10 will preferably be reusable from one manufacturing cycle to another, and for this purpose made of a durable material, such as an aluminum alloy.

[0175] For this purpose, an arrangement of the tool 1 will be provided which will be adapted to the dismantling of the core 10, and more particularly to the dismantling of the angular segments 20, 21, from the inside of the bandage 100.

[0176] To prevent the walls of the grooves 15 from rubbing excessively against the stays 108 or from tearing the stays during the extraction of the angular sectors 20, 21, and more particularly during the extraction of the keys 20, said sectors 20 will each cover a relatively smaller angular sector than the vault sectors 21 around the central axis X2-X2.

[0177] By way of non-limiting example, the construction of the key sectors 20 and vaults 21 of the tool 1 can be carried out with reference to figure 10.

[0178] From a circle with center C, with a diameter equal to 159mm for example, we draw two tangents T1 and T2 to the circle, in bold dotted lines, to form the lateral contours of the key, here in bold. The two tangents T1, T2 form between them an angle al between 1° and 10°, preferably equal to 3°.

[0179] The two lateral contours of the key include, at their radially inner end, a chamfer forming an angle between 3° and 10° with the associated tangent T1, T2. Such a chamfer allows the key segments to be disassembled first.

[0180] To construct the vault segment 21, we draw two tangents T3, T4 to the circle, each passing through the chamfer of the key.

[0181] The radially outer surface of the arch segment forms an angle a2 between 50° and 75°, preferably equal to 75°.

[0182] It is also possible, according to a preferred characteristic, to provide a core 10 within which the sectors 20, 21 contain heating elements, such as electrical heating resistors, to ensure a rapid and uniform rise in temperature of the receiving surface 10. = out during the bandage cooking operation 100.

[0183] As illustrated, each key segment 20 comprises a plurality of grooves 15a distributed, preferably equally distributed, in azimuth around the central axis X2-X2 according to the desired angular repetition pitch for the stays 108. The grooves 15a of the key segments 20 are here radial.

[0184] The key grooves 15a are generated along radial planes containing the central axis X2-X2, as is the case in FIGS. 3A and 3B so as to allow the installation within the bandage 100 of stays 108 extending along said radial planes, as is the case with the bandage of FIGS. 1A and 1B.

[0185] Alternatively, it could also be provided that the key grooves 15a intersect so as to form a grid on the receiving surface 10 out, in order to allow the installation of crossed stays 108 within the bandage 10.

[0186] As illustrated, each arch segment 21 comprises a plurality of grooves 15b distributed, preferably equally distributed, around the central axis X2-X2 at an angle of inclination forming a non-zero angle relative to the radial axis.

[0187] The arch grooves 15b are generated along planes inclined relative to the radial planes containing the central axis X2-X2, as is the case in FIGS. 3A and 3B so as to allow the installation within the bandage 100 of stays 108 extending along said planes inclined relative to the radial planes.

[0188] The grooves 15b of the arch segments 21 are therefore not parallel to the grooves 15a of the key segments 20. Such an arrangement makes it possible to improve the extraction of the core 10 from the bandage 100 after the cooking step.

[0189] Generally, the grooves 15a, 15b are arranged at a variable angle of inclination which depends on the dimension of the core 10.

[0190] Alternatively, it could be provided that the grooves 15a, 15b are all identical and inclined in the same direction.

[0191] The groove 15 is understood to mean the assembly comprising the key grooves 15a and the vault grooves 15b. The width of the groove 15, i.e. the dimension considered in the circumferential direction, will preferably be chosen as a function of a compromise between i) taking into account the width (diameter) of the stay 108, the need to ensure functional clearance between the stay 108 and the side walls which delimit the groove 15, functional clearance which is sufficient to allow the insertion of the stay 108 into the groove 15, then the extraction of the core 10 from the bandage 100, and therefore the extraction of the stay 108 from the groove 15 without jamming and without damage to the stay 108, and ii) maintaining an opening and a groove width which is sufficiently narrow so as not to weaken the core 10 and to ensure good quality support for the components of the bandage 100 placed on the receiving surface 100, and if possible limit the penetration,and therefore the deformation or creep of the materials constituting said components of the bandage 100 in the grooves 15.,

[0192] In this respect, the width of the groove 15, and in particular the width of the opening of the groove 15 at the receiving surface 10 out, will preferably be between 1.01 times and 1.5 times the corresponding dimension of the cross-section of said stay 108, and more preferably the largest dimension of the cross-section of the stay. In practice, if the stay is formed by a wire, single-strand or multi-strand, of substantially circular cross-section, then the considered dimension of the cross-section of the stay will be the diameter of the circular cross-section of the wire.

[0193] Preferably, for the same reasons, and in particular if we are considering stays 108 whose section has a diameter of between 0.25 mm and 2 mm, for example of the order of 1 mm, we will choose a groove width 15 of between 0.1 mm and 3 mm, in particular at the level of the opening at the receiving surface 10 out, preferably between 0.3 mm and 2.2 mm, and for example between 1 mm and 1.8 mm.

[0194] Preferably, all the grooves 15 of the same hemisphere of the core 10, and more preferably all the grooves 15 of the core 10, will have an identical width.

[0195] Furthermore, according to a preferred characteristic which may constitute an invention in its own right, and which may apply to any variant described in the above, in particular when the passages 15 for stays 108 are formed by grooves 15, the tool 1 may comprise an anti-penetration system 30 which cooperates with the core 10 to prevent penetration of the constituent components of the crown 101, the sides 104, 105 or the beads 102, 103 of the bandage 100 into the passages 15 of the core 10 in which the stays 108 are engaged.

[0196] More particularly, the anti-penetration system 30 prevents the materials, and in particular the rubber-based compositions, present in the components of the bandage 100 from penetrating too deeply into the grooves 15 by creep, in order to prevent the formation of rubber burrs which would cause the stays 108 to stick to the walls of the grooves 15, and which would therefore create a risk of the stays 108 being torn off at the time of extraction of the angular sectors 20, 21 from the core 10.

[0197] The anti-penetration system 30 comprises a housing 31, 32 made respectively in each key segment 20 and each vault segment 21.

[0198] Each housing 31, 32 extends radially in each corresponding angular segment 20, 21 in the equatorial plane P = EQ from a radially internal surface 20e, 21e radially outwards, without opening onto the receiving surface 10 = out.

[0199] The anti-penetration system 60 further comprises a circuit 33, 34 for supplying a fluid, each associated with an angular segment of key 20 and vault 21.

[0200] Each fluid supply circuit 33, 34 comprises two main conduits 35, 36; 37, 38 originating in the corresponding supply housing 31, 32 and extending axially respectively towards the lateral zones 12, 13.

[0201] The main conduits 35, 36; 37, 38 successively comprise a first radial part 35a, 36a; 37a, 38a connected to the corresponding supply housing 31, 32, a bent part 35b, 36b; 37b, 38b and a second part 35c, 36c; 37c, 38c inclined obliquely relative to the axial axis parallel to the central axis X2-X2 at an angle between 0° and -10°, for example equal to -5°. The anti-penetration system 30 further comprises two secondary key conduits 39, one of which is visible in FIG. 5B, extending circumferentially from the end of each main conduit 35, 36 in the key segment 20 and two secondary vault conduits 40, one of which is visible in FIG. 6B, extending circumferentially from the end of each main conduit 37, 38 in the vault segment 21.

[0202] The secondary key conduits 39 of the key segments 20 connect the grooves 15a made in the key segments 20 and the secondary vault conduits 40 connect the grooves 15b made in the vault segments 21.

[0203] The main key conduits 35, 36 and the secondary key conduits 39 together form an internal key circuit independent of each key segment 20 allowing a fluid to be brought inside the grooves 15a in each key segment 20.

[0204] The main vault conduits 37, 38 and the secondary vault conduits 40 together form an internal vault circuit independent of each vault segment 21 making it possible to bring a fluid inside the grooves 15b in each vault segment 21.

[0205] This allows for a separate injection into each keystone and vault segment.

[0206] The anti-penetration system 30 comprises a system 41 for injecting a fluid to fill the gas supply circuits and thus the grooves 15, respectively 15a, 15b, thus substantially closing the interstitial space which remains vacant within the passages 15 after the stays 108 have been put in place in said passages 15.

[0207] The injection under pressure of a fluid into the grooves 15 makes it possible to prevent, or significantly slow down, the penetration into the groove 15 of the materials constituting the components of the tire, and in particular of mixtures based on unvulcanized rubber.

[0208] The fluid used is chosen from the group comprising nitrogen, helium, argon, carbon dioxide, any inert gas. Alternatively, the fluid could be water. Of course, the invention also relates to a method S for manufacturing a bandage 100 braced on a core 10.

[0209] In practice, such a method preferably involves using a tool 1 as described above.

[0210] Thus, the invention also relates to a method S for manufacturing a toroidal bandage 100 comprising a crown 101 intended to form a tread, a first annular bead 102 and a second annular bead 104 designed to allow the bandage to be attached to a mounting support such as a rim, as well as a first sidewall 104 and a second sidewall 105 which connect the crown 101 respectively to the first bead 102 and to the second bead 103, the crown 101, the first and second sidewalls 104, 105 and the first and second beads 102, 103 forming as a whole a wall 106 having an internal surface 106 =in concave which delimits a cavity 107 of the bandage 100, said bandage 100 comprising reinforcing elements 108, called “stays” 108, which each extend into the cavity 107 of the bandage by connecting a top anchoring point 109 located in the top 101 of the bandage to a lateral anchoring point 110 located in one of the sides 104, 105 or the beads 102, 103 of the bandage.

[0211] Said method S, described with reference to FIG. 8, comprises a preparation step (S0), during which a tool 1 according to the invention is prepared.

[0212] More particularly, during said preparation step (S0), the key segments 20 and vaults 21 will be assembled to form the core 10, as illustrated in FIGS. 2A and 2B.

[0213] The method S then comprises a step (S2) of installing stays 108, during which at least one reinforcing wire, intended to form a stay 108, is passed through each passage 15 of the core 10.

[0214] Preferably, a single continuous reinforcing wire, single-strand or multi-strand, is used to form several stays 108, preferably more than 25%, more than 50%, or even the entire number of stays 108 of the bandage 100.

[0215] To do this, the continuous reinforcing wire is preferably arranged in a serpentine fashion through the successive passages 15, here by inserting said reinforcing wire into the grooves 15, under the receiving surface 10. = out, and bringing out said reinforcing wire over the receiving surface 10 =out in the top zone 11 and in the lateral zones 12, 13, at the desired anchoring points 109, 110, thereby making said continuous reinforcing wire go and return in one piece from one lateral zone 12 of the core 10 to the other lateral zone 13 via the top zone 11, so as to form undulations, for example of substantially symmetrical amplitude relative to the equatorial plane P = EQ.

[0216] Preferably, following the preparation step (S0), and before the step (S2) of installing stays 108, said method S comprises a pre-filling step (S1) during which, as illustrated in FIG. 6, the receiving surface 10 is placed on the lateral zones 12, 13 and on the top zone 11 =out of the core 10, opposite the anchoring points 1 10, 109 provided for attaching the stays 108 to the wall 106 of the bandage, anchoring structures 71, 72 which are designed to collect the ends of the stays 108 which emerge from the passages 15 of the core 10 and to adhere to the constituent components of the sides 104, 105 or the beads 102, 103, respectively to the constituent components of the crown 101, by sandwiching said ends of the stays 108 between the anchoring structures 71, 72 and said components, in order to ensure the fixing of the stays 108 to the anchoring points 1 10, 109 provided.

[0217] Preferably, the anchoring structures 71, 72 will be formed from unvulcanized rubber-based material, possibly reinforced by means of reinforcing threads or fibers. The anchoring structures 71, 72 may, for example, take the form of reinforcing strips or turns wound on the core 10.

[0218] The anchoring structures 71, 72 being positioned in standby on the receiving face 10 = out, outside the grooved portions, at the desired anchoring points 110, 109, the stays 108 will be put in place in the passages 15 by ensuring that the portions of said stays 108 which emerge from the passages 15 are positioned over said anchoring structures 71, 72, so that when the components of the wall 106 of the bandage are then placed, said components adhere to the anchoring structures already in place on the core 10, and said anchoring structures 71, 72 therefore integrate the wall 106 of the bandage 100, thus pinching the ends of the stays 108 inside the wall 106, at the level of the anchoring points 110, 109 provided.

[0219] Preferably, it is the loops forming the extremes of the undulations of the continuous reinforcing wire coil, and which therefore correspond to the transition zones between two successive stays belonging to the same hemisphere, which form the portions of the stays 108 which will be captive to the lateral anchoring structures 71 placed on the lateral zones 12, 13, to form the lateral anchoring points 1 10 of the stays, while the intermediate portions of the continuous reinforcing wire which connect two successive stays 108 belonging to two different hemispheres, emerging from the groove 15 of the first stay in order to travel through the top zone 1 1 of the receiving surface 10 = out and cross the equatorial plane P = EQ then plunge back into the groove 15 of the second stay 108, will find themselves captive in the summit anchoring structure 72.

[0220] The method then comprises a filling step (S3) during which the following is deposited on the receiving surface 10: = all the constituent components of the top 101, the sides 104, 105 and the beads 102, 103 of the bandage, in order to construct the wall 106 of the bandage 100.

[0221] Said components will preferably comprise rubber-based strips or sheets, possibly reinforced by longitudinal reinforcing threads, made of textile, polymer, or metal. Other reinforcing components may be provided, such as composite strips based on fiberglass and resin.

[0222] All or part of said components may preferably be placed by winding on the rotating core 10.

[0223] The method then comprises a cooking step (S4).

[0224] During this process, the core 10 and the raw bandage carried by said core 10 are placed in a baking mold M, visible in FIG. 7, in order to vulcanize the components of the rubber-based bandage 100. For this purpose, the temperature of the mold, and more particularly of the bandage, will preferably be brought to a value between 120°C and 200°C. During the baking step (S4), the method comprises a step (S5) of supporting the pressure increase, during which an anti-penetration system 30 is implemented which, during the baking step (S4), cooperates with the core 10 to prevent penetration of the constituent components of the crown 101, the sides 104, 105 or the beads 102, 103 of the bandage 100 into the passages 15 of the core 10, here into the grooves 15, in which the stays 108 are engaged.

[0225] During the step (S5) of supporting the pressure increase, a pressurized fluid is injected into the core 10 in order to temporarily fill, at least during the cooking step (S4), the volume of each passage 15 which is left free between the stay 108 engaged in said passage 15 and the opening(s) of said passage 15 which open onto the receiving surface 10. = out.

[0226] As illustrated in Figure 9, the fluid is injected at a pressure which increases progressively, here linearly, according to a first slope, for a first duration T1 of between 50s and 100s, for example equal to 60s, until reaching a pressure of between 35 bars and 80 bars, preferably between 50 bars and 70 bars, to reach a first pressure PI of between 20 bars and 35 bars, then following a second slope for a second duration T2 of between 120s and 200s, for example equal to 150s, to reach a molding pressure P2 of between 35 bars and 80 bars, preferably between 50 bars and 70 bars, preferably between 50 bars and 55 bars.

[0227] The duration of the curing step (S4) is between 500s and 800s at a temperature between 150°C and 200°C, preferably 170°C. The increase in pressure of the molding pressure in the mold allows sufficient expansion of the core 10 and the components of the bandage so that the bandage fills the entire cavity of the mold.

[0228] Before the end of the second period, the components of the raw bandage are flowed and after the end of the second period, the components of the raw bandage are vulcanized, that is to say solid.

[0229] It is the gas pressure which, by blocking the components constituting the bandage outside the grooves 15, effectively gives the molding pressure. Without injection of pressurized gas during the curing step (S4), the components of the raw bandage will penetrate into the grooves 15 and the molding pressure could not be reached the necessary molding pressure of between 35 bars and 80 bars, preferably between 50 bars and 70 bars, preferably equal to 55 bars.

[0230] The injection of the pressurized gas carried out in the pressure build-up support step (S5) starts after a time of between 0s and 10s after the start of the curing step (S4). This has the effect of allowing a small quantity of components forming the bandage to penetrate into the grooves 15 in order to ensure a seal between the core 10 and the raw bandage, allowing the pressurized fluid to be contained in the grooves 15 without leakage into the bandage 100.

[0231] This solution does not require interrupting production to install a mechanical groove sealing device. There is also no hardware to remove after dismantling the core.

[0232] The method then comprises a demolding step (S 6) during which the core 10 is released from the bandage 100 while leaving the stays 108 in place in the cavity 107 of said bandage 100.

[0233] If a part of the core 10 is single-use, it can be destroyed by the appropriate process (melting, dissolution, disintegration, shock, sublimation, etc.) to free the cavity 107 and the stays 108.

[0234] If, as is preferably the case, the core 10 is reusable, and therefore formed from a modular assembly of removable parts, the said parts will be dismantled and gradually extracted to release the bandage 100.

[0235] Preferably, the core 10 comprises a plurality of angular segments alternately of keys 20 and vault 21, each containing the passages 15 of stays 16 in the form of grooves 15 which are open on the receiving surface 10 =out, the demolding step (S6) firstly comprises a first sub-step of removing the key segments 20, then the arch segments 21 from the cavity 107 of the bandage, in order to release the corresponding cavity portion 107 and the stays 108 which are located in said corresponding cavity portion 107, here therefore the stays 108 which occupy the two hemispheres of the bandage 100. Whatever the trajectory initially taken for the extraction movement, once the angular sector 20, 21 is freed from the stays 108, the extraction sequence of said angular sector 20, 21 can be completed freely from the inside of the bandage 100, for example by following a radial movement which brings the angular sector 20, 21 concerned closer to the central axis X2-X2, to radially cross the threshold formed by the bead 102, 103, followed by an axial movement which causes said angular sector 20, 21 to completely exit the envelope which axially delimits the bandage 100.

[0236] Of course, the invention is in no way limited to the embodiment variants described above, the person skilled in the art being able to isolate or freely combine the above-mentioned characteristics, or to substitute equivalents for them.

[0237] Thus, in particular, the nature, shape and dimensions of the object 100, and therefore of the tooling 1 adapted to the manufacture by molding of said object 100, may vary significantly without departing from the scope of the invention. The method may in particular be applied to the manufacture of any rubber-based object, whether this object is a tire or not, and where appropriate whether this tire includes reinforcement stays 108 or not.

[0238] The invention therefore relates as such to a method of manufacturing an object 100 by molding, said method comprising:

[0239] - a preparation step (S0), during which a tool 1 is prepared for molding the object 100 and comprising for this purpose a receiving surface 10 = out which has a shape conjugated to the surface of the object 100, said receiving surface 10 out further comprising a plurality of orifices 15 which extend under said receiving surface 10 = out, and which open onto said receiving surface 10 = out ;

[0240] - a filling step (S3) during which the receiving surface 10 is deposited = all the components C1, C2, C3 constituting the object 100;

[0241] - a cooking step (S4).

[0242] During the filling step (S3), it is preferable to lay, as indicated above, and as appears in the diagram of figure 17, components C1, C2, C3 based on rubber, such as extruded profiles based on rubber, reinforcing strips or reinforcing plies which contain reinforcing threads R1, R2 embedded in a rubber-based material, here denoted "ML" in figure 17.

[0243] Said components C1, C2, C3 can be deposited on the receiving surface 10 out in any suitable form, and by any suitable laying method.

[0244] For information purposes, said components C1, C2, C3 may in particular be wound in one or more turns on the core 10, for example (non-limiting):

[0245] - in a single turn for reinforcement layers each formed from a single piece and which will be placed on the summit area,

[0246] - in one or more turns, possibly superimposed in thickness, for a rubber profile generated by a rubber pump, and intended to form a particular rubber structure such as a bead, or even to be laid incrementally in the form of juxtaposed strips which each occupy an angular sector of the core and which, as a whole, thus reconstitute a reinforcing ply.

[0247] In general, the object 100, particularly if it is a bandage, will comprise several components stacked on top of each other, in the direction of the thickness of the object 100, here in particular in the direction of the radial thickness of the bandage, to form a laminated structure.

[0248] As explained above, during the baking step (S4), the tool 1 is closed on the object 100 to be baked, so as to keep said object 100 captive in a molding cavity, which forms an imprint of shape conjugated to that of the object 100 that it is desired to obtain, so that the walls of the molding cavity compress the object, and therefore compress the components C1, C2, C3 against each other, and the temperature of the object is increased, typically by heating the tool 1, in order to reach an appropriate molding temperature and molding pressure.

[0249] The molding cavity defined by the tool 1, when said tool is closed, may for example correspond to the region delimited between the external receiving surface 10 of an internal core 10 and the internal surface of an external cooking mold M which surrounds the core 10, as illustrated in figure 7 or figure 17.

[0250] The shapes and dimensions of the molding cavity of the tool 1 define the useful shape and dimensions of the object 100, that is to say the shapes and dimensions which one wishes to ensure control over during the molding process, and where appropriate for which one wishes to ensure reproducibility from one object to another, when carrying out several successive moldings with the same tool 1 aimed at producing identical objects.

[0251] Typically, the molding temperature can be between 120°C and 200°C, as indicated above.

[0252] The molding pressure may vary depending on the nature and dimensions of the object 100, and for example may be between 16 bars and 35 bars for certain applications, or between 35 bars and 80 bars for other applications.

[0253] Thus, the molding pressure may, depending on the implementation possibility, be between 16 bars and 35 bars. This may be the case in particular for the manufacture of bandages not including stays 108.

[0254] According to another preferred possibility, particularly applicable in the case of manufacturing bandages provided with reinforcing stays as described above, the molding pressure may be between 35 bars and 80 bars, preferably between 50 bars and 70 bars, more preferably between 50 bars and 55 bars.

[0255] By convention, it is considered that the start of the cooking step (S4) corresponds to the moment when the tool 1, after having been opened to receive the components C1, C2, C3, is closed on the object 100 to be cooked so that the constituent components of the object 100 are compressed inside the molding cavity defined by the closed tool 1, and more particularly are pressed and compressed against the receiving surface 100 out and the corresponding openings of the orifices 15.

[0256] More particularly, the start of the baking step (S4) may correspond to the instant at which the radially external mold M is locked with the internal core 10, so as to compress the constituent components of the bandage 100 against each other, here in particular in radial compression, in the direction of the radial thickness of the bandage, between said mold M and the receiving surface 100 out of the core 10.

[0257] When the tool is closed, the object 100 to be cured is captive in the molding cavity, and occupies the entire finished volume of said molding cavity, which has the effect of placing said object 100 in compression. As indicated above, the intensity of the compression, and therefore the molding pressure, is all the higher as the temperature increases and the expansion of the components C1, C2, C3, and more particularly of the corresponding rubber-based materials ML, relative to the tool 1, is high.

[0258] Of course, to avoid any damage to the tool 1, as well as to the object 100, while guaranteeing sufficient molding pressure and the absence of any appearance defects on the object, it is necessary to ensure that on the one hand the object 100 properly matches the contours of the molding cavity formed by the tool 1, here in particular matches the receiving surface 100, throughout the cooking step (S4), and on the other hand is maintained at an adequate molding pressure, sufficiently high, but not excessive.

[0259] The invention therefore provides an adaptive system, which makes it possible to manage any excess material in the molding cavity, in order to avoid damaging overpressure, while effectively regulating the pressure applied to the object 100 in order to guarantee the application of an appropriate molding pressure.

[0260] This is why, according to the invention, the method comprises, during the cooking step (S4), a step (S5) of supporting the pressure increase, during which a volume of material of the components C1, C2, C3 constituting the object 100 is allowed to penetrate into the orifices 15 in order to form, as can be seen in FIG. 17, a plug 42 which ensures a seal between the object 100 and the receiving surface 100 out, and, while said volume of material thus forms a plug 42, a pressurized fluid is injected into said orifices 15, by means of an anti-penetration system 30 comprising a circuit 33, 34 for supplying a pressurized fluid, so that the pressure of said fluid, which is contained in the orifices 15 by the plug 42 formed by the volume of material, makes it possible to control the flow of said material in said orifices 15, by preventing the penetration of said material into the orifices 15,and allows to reach a molding pressure necessary for the manufacture of the object.,

[0261] Advantageously, the presence of the orifices 15 allows any excess volume of the components C1, C2, C3 which constitute the object 100, which are enclosed in the molding cavity of the tool 1, and which are pressed in compression against the receiving surface 100 out, to overflow from the molding cavity, by pouring into said orifices 15, which prevents the expansion phenomena from generating excessive stress, potentially damaging to the tool 1 and to the proper execution of the manufacturing process.

[0262] Advantageously, this “overflow” function which allows the tool 1 according to the invention to absorb any excess material, takes place on the one hand without disturbing the pressure, and in particular without causing an uncontrolled loss of pressure by excessive discharge of material into the orifices, which makes it possible to guarantee sufficient molding pressure, and on the other hand without causing leakage of the pressurized fluid towards the molding cavity, which makes it possible not only to guarantee that a suitable molding pressure is achieved, but also to avoid infiltration of pressurized fluid between the receiving surface 100 and the corresponding surface of the object 100, infiltration which would detach and locally deform the wall of said object 100; ultimately, this absence of leakage of pressurized fluid towards and into the molding cavity makes it possible to avoid the appearance of a defect in the shape, thickness, and / or appearance of said object 100.

[0263] To this end, the invention provides for controlling the pressure of the pressurized fluid injected by the anti-penetration system 30 in such a way that:

[0264] - on the one hand the pressure of the fluid is sufficiently high at each instant of the curing step (S4), and in particular increases sufficiently, to reach the desired molding pressure and to oppose a controlled resistance to the penetration and the sinking of the material ML of the components C1, C2, C3 into the orifices 15, and therefore prevent excessive penetration of material of the components C1, C2, C3 into said orifices 15, so that the overflow of material from the molding cavity is adjusted to a measure just necessary to avoid the appearance of an over-stress damaging to the tool 1, while maintaining the components C1, C2, C3 and more generally the object 100 under a sufficiently high pressure;

[0265] - and on the other hand that the pressure of the fluid is sufficiently moderate, at each instant of the cooking step (S4), so as not to force the plug 42, which makes it possible to contain the fluid under pressure in the volume of the orifice 15 located set back from the molding surface l O out, and which therefore prevents a leak of fluid under pressure from the orifice 15 into the molding cavity, between the object 100 and the receiving surface l O out; thus, the pressurized fluid is prevented from forcing the material of the components C1, C2, C3 out of the orifice 15, into the molding cavity, and therefore any intrusion of said pressurized fluid into the molding cavity is avoided, in particular between the receiving surface l0 out and the surface to be molded of the object 100. The surface of the object 100, the shape and dimensions of which are to be controlled, therefore advantageously remains in contact against the receiving surface l0 out of conjugate shape throughout the curing step (S4).

[0266] Advantageously, the method according to the invention, and therefore the corresponding tool 1 (associated with the anti-penetration system 30) makes it possible to authorize, as much as necessary, a penetration into the orifices 15 of material coming from the molding cavity, in this case of an excess of material resulting from the installation of the components C1, C2, C3 constituting the object, in order to provide an outlet for the expansion of this excess of material, while limiting the penetration of said material into said orifices 15, and more particularly its sinking into said orifices 15, under the receiving surface 10 out, thanks to the controlled pressure exerted, against said material, in the orifices 15, by the pressurized fluid.

[0267] It will be possible to envisage different laws for controlling the pressure of the fluid injected into the orifices 15, depending for example on the nature and thickness of the components C1, C2, C3 used, the shapes and dimensions of the object 100, etc.

[0268] Preferably, the injection of the pressurized fluid carried out in step (S5) of supporting the pressure increase starts after a duration of between Os and 10s after the start of the cooking step (S4).

[0269] More particularly, the injection of the pressurized fluid carried out in step (S5) of supporting the pressure increase starts after a duration of between 0.5 seconds and 10 seconds after the start of the cooking step (S4).

[0270] In other words, the injection of the pressurized fluid may begin at the earliest simultaneously with the mechanical compression of the object 100 caused by the closing of the tool 1, and more preferably begin slightly later than the closing of the tool 1, closing which has the effect of prestressing the raw object 100 in compression and marks the start of the cooking step (S4).

[0271] Said delay allows in particular to give the plugs 42 time to form, and thus to close the orifices 15 before the latter are filled by the pressurized fluid coming from the supply circuit 33, 34.

[0272] Furthermore, it will be preferable to implement a progressive increase in pressure, in order to preserve the plugs 42 and to allow the material of the components C1, C2, C3 to begin to vulcanize, and therefore to be able to provide better resistance to creep under pressure, as the pressure increases.

[0273] Thus, preferably, the fluid is injected at a pressure which increases progressively for a period of between 30 seconds and 300 seconds, for example between 30 seconds and 120 seconds, or between 50 seconds and 120 seconds, or between 120 seconds and 200 seconds, until reaching the molding pressure. Which molding pressure may preferably be between 16 bars and 35 bars, or between 35 bars and 80 bars, and then in particular between 50 bars and 70 bars, more preferably between 50 bars and 55 bars.

[0274] For example, if the molding pressure is between 16 bars and 35 bars, it is preferable to use a pressure rise time of between 30 seconds and 120 seconds, or between 50 seconds and 120 seconds.

[0275] If the molding pressure is between 35 bars and 80 bars, in particular between 50 bars and 70 bars, or preferably between 50 bars and 55 bars, then it is preferable to use a pressure rise time of between 120 seconds and 300 seconds, for example between 120 seconds and 200 seconds, or even between 120 seconds and 150 seconds.

[0276] Many possible control laws can be envisaged, depending in particular on the composition of the materials of the components C1, C2, C3 constituting the object 100, the dimensions and in particular the thickness of said object 100, the required molding temperature and molding pressure, etc.

[0277] In all cases, care should preferably be taken to ensure that the pressure builds up gradually until the molding pressure is reached, by distributing this progression over a period which will preferably be greater than or equal to 30 seconds, 40 seconds, or even 50 seconds, for example between 50 seconds and 300 seconds, in particular between 120 seconds and 200 seconds.

[0278] In particular, care should be taken not to exceed a predetermined maximum pressure increase speed limit, for example a speed limit of 3 bars / second, or 1 bar / second, or even 0.6 bar / second.

[0279] The pressure increase over time may follow a linear evolution, possibly in several successive sections with different slopes, or a curved evolution of a chosen profile.

[0280] For example, with reference to Figure 9, a pressure control law may be provided according to which the fluid is injected at a pressure which increases linearly according to a first slope, for a first duration, preferably between 50s and 100s, for example equal to 60s, until a pressure of between 20 bars and 35 bars is reached at a first instant (T1), then following a second slope for a second duration, to reach, at a second instant (T2) preferably between 120s and 200s, for example equal to 150s, the molding pressure (P2), the latter preferably being between 35 bars and 80 bars, preferably between 50 bars and 70 bars, more preferably between 50 bars and 55 bars.

[0281] Preferably, and as explained above, the orifices 15 are formed by grooves hollowed out in the thickness of the receiving surface 10 out.

[0282] The use of orifices 15 of elongated shape, rather than simple holes of circular section, will in fact make it possible to easily cover, and where appropriate in a relatively homogeneous manner, a large area of ​​the receiving surface 10 out, and will make it possible to easily accommodate any surplus volume of material caused by the expansion of the components C1, C2, C3, even if this surplus represents a relatively large quantity of material.

[0283] Furthermore, the use of grooves may sometimes facilitate the machining of the orifices 15 on the receiving surface 10 out and therefore the manufacture of the tooling, in particular when these grooves are shallow, for example if said grooves have, according to a preferred possibility, a machining depth of 2 mm to 6 mm, for example 3 mm to 6 mm, from the receiving surface 10 out.

[0284] The use of grooves is also particularly suitable when one wishes to manufacture a 100 bandage reinforced by 108 stays.

[0285] Preferably, as already mentioned above, the object 100 is a toroidal bandage of a tire, which bandage comprises a crown 101 intended to form a tread, a first annular bead 102 and a second annular bead 103 designed to allow the bandage 100 to be attached to a mounting support, as well as a first sidewall 104 and a second sidewall 105 which connect the crown 101 respectively to the first bead 102 and to the second bead 103, the crown 101, the first and second sidewalls 104, 105 and the first and second beads 102, 103 forming as a whole a wall 106 having an internal surface 106 = in concave which delimits the cavity 107 of the bandage 100.

[0286] The tool 1 then preferably comprises a toroidal core 10 having, around its central axis (X2-X2), a receiving surface 10^out which has a shape conjugated to the internal surface 106 = in of the wall 106 of the bandage and which comprises for this purpose a top zone 11, radially external, intended to receive components constituting the top 101 of the bandage 100, and, on either side axially of said top zone 11, a first lateral zone 12 folded towards the central axis (X2-X2) and intended to receive components constituting the first flank 104 and the first bead 102 as well as a second lateral zone 13 folded towards the central axis (X2-X2) and intended to receive components constituting the second flank 105 and the second bead 103, so that the core 10 materializes a volume which is delimited externally by the receiving surface 10 = out and which corresponds to the cavity 107 of the bandage.

[0287] According to a preferred arrangement possibility, which may correspond to Figure 6 or Figure 11, at least some of the orifices 15, or even all of the orifices 15, are formed by grooves which extend along radial planes containing the central axis (X2-X2) of the toroidal core.

[0288] More particularly, according to a possible arrangement which corresponds to that of figures 11 and 12, at least one, and preferably each, of the grooves 15 has a continuous opening along the profile of the receiving surface 10 = out considered in a radial plane containing the central axis (X2-X2) of the toroidal core, so that said opening of said groove 15 continuously covers the first lateral zone 12 then the summit zone 11 then the second lateral zone 13.

[0289] According to a possible application, the toroidal bandage of a tire 100 permanently comprises reinforcing elements 108, called "stays" 108, which each extend into the cavity 107 of the bandage by connecting a top anchoring point 109 located in the crown 101 of the bandage to a lateral anchoring point 110 located in one of the sidewalls 104, 105 or the beads 102, 103 of the bandage, as can be seen in particular in FIGS. 1A and 1B.

[0290] The toroidal core 10 then comprises, as can be seen in FIGS. 2B, 3 and 6, a plurality of orifices 15 forming passages which extend inside the reserved volume, under the receiving surface 10. = out, and which open onto the receiving surface 10 =out such that each of said passages 15 connects the top zone 11 of the receiving surface to one of the first and second lateral zones 12, 13 so that the core 10 can receive, inside said passages 15, reinforcing elements 108.

[0291] The method according to the invention then preferably comprises:

[0292] - a pre-filling step (SI) during which the receiving surface 10 is placed on the lateral zones 12, 13 and on the top zone 11 =out of the core 10, opposite the anchoring points 1 10, 109 provided for attaching the reinforcing elements 108 to the wall 106 of the bandage, anchoring structures 71, 72 which are designed to collect the ends of the reinforcing elements 108 which emerge from the grooves 15 of the core 10 and to adhere to the constituent components of the flanks 104, 105 or the beads 102, 103, respectively to the constituent components of the crown 101, by sandwiching said ends of the reinforcements 108 between the anchoring structures 71, 72 and said components, in order to ensure the fixing of the reinforcements 108 to the anchoring points 1 10, 109 provided;

[0293] - a step (S2) of placing the reinforcing elements 108, during which at least one reinforcing wire, intended to form a reinforcing element 108, is passed through at least one passage 15 of the core (10), as illustrated in FIG. 6;

[0294] - a filling step (S3) during which the receiving surface 10 is deposited = all the constituent components of the top 101, the sides 104, 105 and the beads 102, 103 of the bandage, in order to construct the wall 106 of the bandage 100.

[0295] According to another preferred arrangement possibility, which corresponds to figures 13, 14, 15 and 16, at least some of the orifices 15, or even all of the orifices 15, are formed by circumferential grooves which extend around the central axis (X2-X2), preferably along planes normal to the central axis (X2-X2) of the toroidal core 10.

[0296] Such an arrangement makes it possible in particular to arrange the grooves in a secant manner relative to the reinforcing threads RI, R2 contained in the reinforcing plies, so that said grooves are not parallel to the reinforcing threads RI, R2, which makes it possible to effectively support the reinforcing threads RI, R2 against the creep of the material ML, and thus to prevent one or more of said reinforcing threads RI, R2 from being accidentally displaced in an orifice 15, thus causing a defect in the reinforcement of the bandage 100.

[0297] Furthermore, such a circumferential arrangement of the grooves 15 makes it possible to ensure a homogeneous distribution of the overflow structure and therefore of the pressure regulation all around the central axis (X2-X2), and in particular in the summit zone 11, which can be easily sensitive to variations in volume during the installation of the components C1, C2, C3, taking into account the manufacturing and / or dosage tolerances during the installation of said components C1, C2, C3.

[0298] It is preferable to use as pressurized fluid any “inert” or “neutral” gas, i.e. one which does not chemically interact with the component(s) C1, C2, C3 constituting the object 100 with which said gas comes into contact, and in particular a gas which does not interact with, and more particularly which does not oxidize or corrode, the rubber-based mixtures ML and / or the reinforcements RI, R2, in particular the metal reinforcements, present in said components C1, C2, C3 constituting the object 100.

[0299] Thus, preferably, the fluid used is an inert gas chosen from the group comprising nitrogen, helium, argon, carbon dioxide.

[0300] Preferably, as already mentioned in the above, the components C1, C2, C3 constituting the tire comprise rubber-based ML materials, and the curing step (S4) makes it possible to vulcanize said rubber-based ML materials.

[0301] According to a preferred characteristic which may constitute an invention in its own right, applicable to any method or tool 1 for molding an object 100, in particular for molding an object 100 based on rubber such as a tire, the volume of material, called "excess volume", corresponding to the volume of material having penetrated into the orifices 15 during the curing step (S4), here therefore typically the cumulative volume of all the flashes forming plugs 42, represents, after curing and demolding of the object 100, and at an ambient temperature of between 5°C and 40°C, between 0.5% and 5% of the total volume of the object 100, more preferably between 2% and 4% of the total volume of the object 100.

[0302] It will be noted that this volume ratio remains substantially valid “hot”, that is to say at molding temperature, during the cooking step (S4), tool 1 closed, but of course remains simpler to observe after demolding, on the object 100 as extracted from the tool 1, and therefore cooled to reach room temperature.

[0303] According to a preferred implementation possibility, during the filling step (S3), a component C1, C2, C3 constituting the object 100, or a set of components C1, C2, C3 constituting the object, is placed on the receiving surface l0 out, knowing a tolerance which quantifies the possible error on the volume thus placed of said component or set of components C1, C2, C3, and a compensation operation is carried out during which an additional component, such as a rubber mixture ML, is added to the receiving surface l0 out, in addition to said component or set of components C1, C2, C3, to a volume called the “compensatory volume” which is at least equal to the difference between, on the one hand, the desired nominal volume of the component or set of components C1, C2,C3 constituting the object and on the other hand the low value of the potentially placed volume of said component or group of components taking into account the known tolerance, then, during the cooking step (S4), if the cumulative volume of the additional component and of the component or set of components C1, C2, C3 exceeds the desired nominal volume, taking into account the desired molding pressure, then the corresponding excess material is absorbed thanks to the flow of said excess material in the orifices 15.,

[0304] In other words, it is ensured that, during the filling step (S3), a total volume of components is placed on the receiving surface 10 out such that said volume will ensure complete filling of the molding cavity of the tooling when the tooling is closed 1, and then, during the baking step (S4), a level of compression under expansion sufficient to reach the desired molding pressure, whatever the variations in volume of the components C1, C2, C3 inherent in the manufacturing processes, and / or in the dosing processes during the placement of said components C1, C2, C3.

[0305] More particularly, it is thus possible to choose to systematically add, in addition to the components C1, C2, C3 constituting the object, an additional component, typically a rubber mixture, in a known quantity which will make it possible to compensate for the worst foreseeable deficit of material attributable to the manufacturing and / or installation tolerances of said constituent components of the object 100.

[0306] Thus, even if we observe the most serious material deficit predicted by the low tolerances associated with the components C1, C2, C3 concerned, we are assured that the molding cavity will be filled at least to the desired nominal volume.

[0307] If the total volume corresponding to the sum of the volume of the components C1, C2, C3 constituting the object and the compensatory volume provided by the additional component exceeds the desired nominal volume, the excess volume will advantageously be absorbed by the orifices 15 during the cooking step (S4), so that this excess volume will not cause overpressure which would be harmful to the tool 1.

[0308] The addition of additional material intended to compensate for a possible material deficit in one and / or the other of the components C1, C2, C3 constituting the object 100 may of course be located in certain particular zones of the tool 1, and more particularly of the receiving surface 100 out, where said component(s) C1, C2, C3 likely to have a volume deficit are located.

[0309] Thus, for example, if the uncertainty on the volume laid comes from a component forming a reinforcing ply intended to cover the top zone 1 1 , called the “crown ply”, and the corresponding tolerance on the volume is + / - 10% relative to the nominal volume of said component, then an excess thickness of additional rubber mixture intended to compensate for any deficit will be added to the top zone 1 1 , here over the entire axial width of the top zone concerned by the reinforcing ply, and therefore representing 10% of the nominal thickness of the reinforcing ply, over the width considered.More particularly, if two reinforcing plies are superimposed on the top zone 1 1, each having a nominal thickness of 2 mm, i.e. a total thickness of 4 mm for the two plies together, and a volume tolerance, and more particularly a thickness tolerance, of + / - 10%, then a thickness of 0.4 mm (= 10% x 4 mm) of additional rubber compound will be added, over the entire width of the top zone 1 1 covered by said reinforcing plies.

[0310] One could of course envisage numerous arrangements of grooves, other than those described above, and in particular grooves which would have openings forming a curved path, for example sinusoidal, on the receiving surface l O out.

[0311] It would thus be possible to envisage, for example, circumferential grooves, the outline of which, which forms a loop around the central axis X2-X2 of the core 10, also has undulations 43 which draw a sinuous outline, preferably a sinusoid, on the receiving surface 10 out, for example on the summit zone 11 of the core 10 as illustrated in FIG. 18. Said undulations 43 could thus form transverse alternations, on either side of a mean circumferential line.

[0312] We could also envisage undulations 43, in particular sinusoidal, which oscillate around a mean line which would be oriented at a non-zero angle relative to a circumferential direction, and for example at an angle of 90 degrees so that said mean line would extend according to the intersection of the receiving surface l O out with a radial plane containing the central axis (X2-X2).

[0313] Said angle could alternatively be strictly between 0 degrees and 90 degrees, for example between 10 degrees and 80 degrees, in particular between 10 degrees and 45 degrees, so that the mean line of the opening of the groove 15, around which the outline of the opening of the groove forms undulations 43, would extend obliquely relative to the circumferential direction.

[0314] In either case, the same sinusoidal groove 15 may extend within the top zone 11 alone, a lateral zone 12, 13 alone, or cover a top zone 11 and a lateral zone 12, 13, or even extend right through the receiving surface 10 out, covering the first lateral zone 12, the top zone 11, and the second lateral zone 13.

[0315] More generally, the grooves 15 will preferably be located opposite a zone of the tool 1, and more particularly a zone of the core 10, in which it is known that a fluctuation in the volume of the components C1, C2, C3 constituting the object is likely to occur, due to the tolerances inherent in the manufacturing or preparation technology of said component, and / or the tolerances inherent in the installation technology, for example the dosage precision, implemented during the filling step (S3).

[0316] For information purposes, the surface area covered by the openings of the groove(s) 15 on the receiving surface 10 out, in a zone concerned, for example in the summit zone 11, may represent between 3% and 15%, for example between 5% and 10%, of the total surface area of ​​the zone concerned.

[0317] Furthermore, preferably, care will be taken to ensure that the outline of the same groove 15, and more particularly the outline of the opening of said groove 15 at the receiving surface 10 out, is, if possible, not exactly parallel to the outline of the reinforcing elements (for example metal wires) which are embedded in the components C1, C2, C3 constituting the object, typically the reinforcing wires RI, R2 embedded in a reinforcing ply present in the crown zone 11 of the bandage, and which are located at the right angle to the opening of said groove 15, and which are closest to the opening of the groove considering the distance which separates them from said opening of the groove 15 in a direction normal to the receiving surface 10 out (in practice, it may be the reinforcing wires RI, R2 closest to the crown zone 11 of the receiving surface, considered in the direction of the radial thickness of the bandage).

[0318] Thus, it will preferably be ensured that the reinforcements RI, R2 embedded in the components C1, C2, C3 constituting the object are intersecting with the openings of the grooves 15, and therefore cross the path of said openings of the grooves 15 transversely to said path of said openings, forming with said path of the openings a non-zero angle, ideally an angle of at least 10 degrees, or at least 30 degrees, or even approximately 80 degrees to 90 degrees.

[0319] In this way, it will be advantageous to avoid, during the curing step (S4), one or other of the reinforcing elements RI, R2 embedded in the constituent components of the object 100, for example a reinforcing wire of one of the plies reinforcing the top of the tire, being driven out of the molding cavity of the tool 1 and expelled into the groove 15, under the effect of the molding pressure and the resulting creep phenomenon which forces the material, typically the rubber-based material ML, in which said reinforcing element RI, R2 is initially embedded, to penetrate into the groove 15. This will avoid accidentally and irreversibly damaging and destructuring the object 100 during the curing step (S4).

[0320] It will be noted that a sinusoidal groove path 15 can be particularly favorable to the good holding in place of the reinforcements RI, R2 of the components C1, C2, C3 during cooking, because such a path prevents, at any location on the receiving surface l0 out, and in normal projection in a plane tangent to the receiving surface l0 out at the point considered, the path of the groove 15 from being tangent and superimposed on the path of one or other of the reinforcements RI, R2 present in the components C1, C2, C3 closest to the receiving surface l0 out, and therefore from forming a “trap” into which the reinforcement could “fall” under the molding pressure.

[0321] Furthermore, whatever the arrangement envisaged for the grooves 15, in particular among the different arrangements mentioned in the present application, the core 10 may preferably be subdivided into sectors 20, 21 comprising keys 20 and vaults 21 whose characteristics, in particular of shape, number, dimensions or even arrangement of the joint planes may be taken from the above.

[0322] The invention 1 of course relates to a tool 1 allowing the implementation of the method described above, and in particular a toroidal core 10.

[0323] Thus, the invention relates in particular to a toroidal core 10 intended for a tool 1 making it possible to implement a method according to the invention for the manufacture by molding of an object 100 forming a bandage, said toroidal core 10 having, around its central axis (X2-X2), a receiving surface 10 =out which comprises a top zone 11, radially external, and, on either side axially of said top zone 11, a first lateral zone 12 folded back towards the central axis (X2-X2) as well as a second lateral zone 13 folded back towards the central axis (X2-X2), orifices 15 formed by grooves hollowed out in the thickness of the receiving surface 10 out, and a supply circuit 33, 34 comprising conduits 35, 36, 37, 38, 39, 40 making it possible to supply said grooves 15 with a pressurized fluid, said toroidal core 10 having one of the groove arrangements among the following arrangements:

[0324] - a first arrangement called “shroud groove arrangement”, illustrated here in Figures 2A to 7, according to which each groove 15 opens onto the receiving surface 10 =out so as to connect by a continuous opening the top zone 1 1 of the receiving surface to one of the first and second lateral zones 12, 13 so that the core (10) can receive, inside said grooves, reinforcing elements 108 called "stays", designed to permanently integrate the structure of the bandage 100 and extend into the internal cavity 107 of said bandage by connecting a top anchoring point 109 located at the top 101 of the bandage 100 to a lateral anchoring point 1 10 located in one of the flanks 104, 105 or the beads 102, 103 of the bandage 100;

[0325] - a second arrangement of grooves, called "radial arrangement", corresponding for example to the variant embodiment illustrated in figures 11 and 12, according to which the grooves extend along planes radial to the central axis (X2-X2) of the core, each opening continuously on the receiving surface 10 out from the first lateral zone 12 inclusive to the second lateral zone 13 inclusive, passing through the top zone 11;

[0326] - a third arrangement, called "circumferential top arrangement", which is found in particular in the variant embodiment illustrated in figures 15 and 16, as well as in figures 13 and 14, and according to which at least one groove 15, and preferably several parallel grooves 15, extend circumferentially around the central axis (X2-X2), on the top zone 11, preferably along planes normal to the central axis (X2, X2);

[0327] - a fourth arrangement called "complete circumferential arrangement", which corresponds in particular to the variant embodiment illustrated in Figures 13 and 14, and according to which on the one hand at least one groove 15, and preferably several parallel grooves 15, extend circumferentially around the central axis (X2-X2), on the summit zone 11, preferably along planes normal to the central axis (X2, X2), and on the other hand at least one groove 15, possibly several grooves 15, extend circumferentially in at least one of the first and second lateral zones 12, 13, and more preferably in each of the first and second lateral zones 12, 13;

[0328] - a fifth arrangement, called a “sinusoidal arrangement”, which is found in particular in the variant embodiment shown in Figure 18, and according to which at least one groove 15, preferably a groove 15 which extends circumferentially around the central axis (X2-X2), has an opening which has, on the receiving surface 10 out, undulations 43 so as to form a sinuous, preferably sinusoidal, path.

[0329] The invention of course finally relates to an object 100, in particular a rubber-based object 100, and in particular a tire 100 intended to form a pneumatic tire, such as resulting from a manufacturing method according to the invention, and in particular comprising, on the face having borne on the receiving surface 100 and provided with orifice 15, and more particularly with grooves 15, ribs 15 of a shape matching that of the grooves 15, for example ribs projecting over a height of 2 mm to 6 mm relative to the face of the object 100, or traces of such ribs, which result from the controlled flow of the material in the grooves 15 during the curing step (S4).

Claims

(100) by molding, said method comprising: - a preparation step (S0), during which a tool (1) is prepared for molding the object (100) and comprising for this purpose a receiving surface (10 = out) which has a shape conjugated to the surface of the object (100), said receiving surface (10 out) further comprising a plurality of orifices (15) which extend under said receiving surface (10 = out), and which open onto said receiving surface (10 = out); - a filling step (S3) during which the following is deposited on the receiving surface ( 10 = out) the constituent components of the object (100); - a cooking step (S4);said method being characterized in that it comprises, during the cooking step (S4), a step (S5) of supporting the pressure increase, during which a volume of material of the constituent components of the object (100) is allowed to penetrate into the orifices (15) in order to form a plug which ensures a seal between the object (100) and the receiving surface (100 out), and, while said volume of material thus forms a plug, a pressurized fluid is injected into said orifices (15), by means of an anti-penetration system (30) comprising a circuit (33, 34) for supplying a pressurized fluid, so that the pressure of said fluid, which is contained in the orifices (15) by the plug formed by the volume of material, makes it possible to control the flow of said material in said orifices (15), by preventing the penetration of said material into the orifices (15). 15), and to achieve a molding pressure necessary for the manufacture of the object.; 2. Method according to claim 1, characterized in that the injection of the pressurized fluid carried out in step (S5) of supporting the pressure build-up starts after a time between Os and 10s after the start of the cooking step (S4).

3. Method according to claim 1 or 2 characterized in that the molding pressure is between 16 bars and 35 bars, or between 35 bars and 80 bars, preferably between 50 bars and 70 bars, more preferably between 50 bars and 55 bars.

4. Method according to one of claims 1 to 3, characterized in that the fluid is injected at a pressure which increases progressively for a period of between 30 seconds and 300 seconds, for example between 30 seconds and 120 seconds, or between 50 seconds and 120 seconds, or between 120 seconds and 200 seconds, until the molding pressure is reached, preferably between 16 bars and 35 bars, or between 35 bars and 80 bars.

5. Method according to one of the preceding claims, characterized in that the orifices (15) are formed by grooves hollowed out in the thickness of the receiving surface (10 out).

6. Method according to one of the preceding claims, characterized in that the object (100) is a toroidal bandage of a tire, which bandage comprises a crown (101) intended to form a tread, a first annular bead (102) and a second annular bead (103) designed to allow the bandage (100) to be attached to a mounting support, as well as a first sidewall (104) and a second sidewall (105) which connect the crown (101) respectively to the first bead (102) and to the second bead (103), the crown (101), the first and second sidewalls (104, 105) and the first and second beads (102, 103) forming as a whole a wall (106) having an internal surface (106 =in) concave which delimits the cavity (107) of the bandage (100), and in that the tool (1) comprises a toroidal core (10) having, around its central axis (X2-X2), a receiving surface (10 = out) which has a shape conjugated to the internal surface ( 106 = in) of the wall (106) of the bandage and which comprises for this purpose a top zone (11), radially external, intended to receive components constituting the top (101) of the bandage (100), and, on either side axially of said top zone (11), a first lateral zone (12) folded towards the central axis (X2-X2) and intended to receive components constituting the first flank (104) and the first bead (102) as well as a second lateral zone (13) folded towards the central axis (X2-X2) and intended to receive components constituting the second flank (105) and the second bead (103), so that the core (10) materializes a volume which is delimited externally by the receiving surface (10 = out) and which corresponds to the cavity (107) of the bandage.

7. Method according to claims 5 and 6 characterized in that at least some of the orifices (15), or even all of the orifices (15), are formed by grooves which extend along radial planes containing the central axis (X2-X2) of the toroidal core.

8. Method according to claim 7 characterized in that at least one, and preferably each, of the grooves has a continuous opening along the profile of the receiving surface (10 =out) considered in a radial plane containing the central axis (X2-X2) of the toroidal core, so that said opening of said groove continuously covers the first lateral zone (12) then the top zone (11) then the second lateral zone (13).

9. Method according to claim 6 or 7 characterized in that the toroidal bandage of a tire (100) permanently comprises reinforcing elements (108), which each extend into the cavity (107) of the bandage by connecting a top anchoring point (109) located in the crown (101) of the bandage to a lateral anchoring point (110) located in one of the sidewalls (104, 105) or beads (102, 103) of the bandage, in that the toroidal core (10) comprises a plurality of orifices (15) forming passages which extend inside the reserved volume, under the receiving surface (10 = out), and which open onto the receiving surface (10 =out) so that each of said passages (15) connects the top zone (11) of the receiving surface to one of the first and second lateral zones (12, 13) so that the core (10) can receive, inside said passages (15), reinforcing elements (108), and in that said method comprises: - a pre-filling step (SI) during which the lateral zones (12, 13) and the top zone (11) of the reception area (10 =out) of the core (10), opposite the anchoring points (110, 109) provided for attaching the reinforcing elements (108) to the wall (106) of the tire, anchoring structures (71, 72) which are designed to collect the ends of the reinforcing elements (108) which emerge from the grooves (15) of the core (10) and to adhere to the constituent components of the flanks (104, 105) or the beads (102, 103), respectively to the constituent components of the crown (101), by sandwiching said ends of the reinforcements (108) between the anchoring structures (71, 72) and said components, in order to ensure the fixing of the reinforcements (108) to the anchoring points (110, 109) provided; - a step (S2) of placing the reinforcing elements (108), during which at least one reinforcing wire, intended to form a reinforcing element (108), is passed through at least one passage (15) of the core (10), - a filling step (S3) during which the following is deposited on the receiving surface ( 10 = out) the constituent components of the top (101), the sides (104, 105) and the beads (102, 103) of the bandage, in order to construct the wall (106) of the bandage (100).

10. Method according to claims 5 and 6 characterized in that at least some of the orifices (15), or even all of the orifices (15) are formed by circumferential grooves which extend around the central axis (X2-X2), preferably along planes normal to the central axis (X2-X2) of the toroidal core. 1 1. Method according to one of the preceding claims, characterized in that the fluid used is an inert gas chosen from the group comprising nitrogen, helium, argon, carbon dioxide.

12. Method according to one of the preceding claims, characterized in that the constituent components of the tire comprise rubber-based materials, and in that the baking step (S4) makes it possible to vulcanize said rubber-based materials.

13. Method according to one of the preceding claims, characterized in that the volume of material, called "excess volume", corresponding to the volume of material having penetrated into the orifices (15) during the cooking step (S4), represents, after cooking and demolding of the object (100), and at an ambient temperature between 5°C and 40°C, between 0.5% and 5% of the total volume of the object (100), more preferably between 2% and 4% of the total volume of the object (100).

14. Method according to one of the preceding claims, characterized in that, during the filling step (S3), a component (C1, C2, C3) constituting the object, or a set of components (C1, C2, C3) constituting the object, is placed on the receiving surface (10 out), and, knowing a tolerance which quantifies the possible error on the volume thus placed of said component or set of components, and a compensation operation is carried out during which an additional component, such as a rubber mixture, is added to the receiving surface (10 out), in addition to said component or set of components (C1, C2, C3), to a level of a volume called "compensatory volume" which is at least equal to the difference between, on the one hand, the desired nominal volume of the component or set of components (C1, C2, C3) constituting the object and, on the other hand, the low value of the potentially placed volume of said component or set of components (C l , C2,C3) taking into account the known tolerance, then, during the cooking step (S4), if the cumulative volume of the additional component and the component or group of components (C1, C2, C3) exceeds the desired nominal volume, taking into account the desired molding pressure, then the corresponding excess material is absorbed by the flow of said excess material into the orifices (15)., 15. Toroidal core (10) intended for a tool (1) making it possible to implement a method according to one of the preceding claims for the manufacture by molding of an object (100) forming a bandage, said toroidal core (10) having, around its central axis (X2-X2), a receiving surface (10 =out) which comprises a top zone (11), radially external, and, on either side axially of said top zone (11), a first lateral zone (12) folded towards the central axis (X2-X2) as well as a second lateral zone (13) folded towards the central axis (X2-X2), orifices (15) formed by grooves hollowed out in the thickness of the receiving surface (10 out), and a supply circuit (33, 34) comprising conduits (35, 36, 37, 38, 39, 40) for supplying said grooves (15) with a pressurized fluid, said toroidal core having one of the groove arrangements among the following arrangements: - a first arrangement called “shroud groove arrangement”, according to which each groove opens onto the receiving surface (10 =out) so as to connect by a continuous opening the top zone (11) of the receiving surface to one of the first and second lateral zones (12, 13) so that the core (10) can receive, inside said grooves, reinforcing elements (108) called "stays", designed to permanently integrate the structure of the bandage (100) and extend into the internal cavity (107) of said bandage by connecting a top anchoring point (109) located at the top (101) of the bandage (100) at a lateral anchor point (110) located in one of the flanks (104, 105) or beads (102, 103) of the bandage (100); - a second arrangement of grooves, called "radial arrangement", according to which the grooves extend along planes radial to the central axis (X2-X2) of the core, each opening continuously onto the receiving surface (10 out) from the first lateral zone (12) inclusive to the second lateral zone (13) inclusive, passing through the top zone (11); - a third arrangement, called "circumferential top arrangement" according to which at least one groove, and preferably several parallel grooves, extend circumferentially around the central axis (X2-X2), on the top zone (11), preferably along planes normal to the central axis (X2, X2); - a fourth arrangement called "complete circumferential arrangement", according to which on the one hand at least one groove, and preferably several parallel grooves, extend circumferentially around the central axis (X2-X2), on the summit zone (11), preferably along planes normal to the central axis (X2, X2), and on the other hand at least one groove, possibly several grooves, extend circumferentially in at least one of the first and second lateral zones (12, 13), and more preferably in each of the first and second lateral zones (12, 13); - a fifth arrangement, called "sinusoidal arrangement", according to which at least one groove, preferably a groove which extends circumferentially around the central axis (X2-X2), has an opening which has, on the receiving surface (10 out), undulations (43) so as to form a sinuous, preferably sinusoidal, path.

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