Grooved core tool for manufacturing pneumatic tires reinforced with stays that pass through the expansion cavity

Abstract

The invention relates to a tool (1) intended for the manufacture of a toroidal shaped tire casing (2) comprising a crown (3), a first annular bead (4) and a second annular bead (5) as well as a first sidewall (6) and a second sidewall (7), the tool (1) comprising a core (10) provided with groove-type passages (15) intended to receive reinforcing elements called "stays" (16) that are permanently integrated into the structure of the tire casing (2) and extend through the tire cavity (9) to connect a crown fastening point (17) located in the crown (3) of the casing to lateral fastening points (18) located in one of the sidewalls (6,7) or in the beads (5,6) of the casing, respectively.

Description

Technical Field

[0001] The present invention relates to the general field of manufacturing doughnut-shaped tires, and more specifically pneumatic tires, intended to be mounted on vehicle wheels.

Background Art

[0002] In order to improve the performance of pneumatic tires, particularly their cornering, the applicant had the idea of implementing stay reinforcements that extend inside the doughnut-shaped inflation cavity defining the tire and connect attachment points located on the sidewall or bead of the tire to attachment points each located on the crown of the tire.

[0003] Of course, industrial manufacturing tools are unsuitable for generating such stayed tires due to their very special shape.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The object assigned to the present invention is thus to propose a tool and a manufacturing method that overcome the aforementioned drawbacks and make it possible to obtain high-quality stayed tires in a relatively simple and reproducible manner.

Means for Solving the Problems

[0005] The object assigned to the present invention is achieved using a tool suitable for manufacturing a donut-shaped tire comprising a crown suitable for forming a tread, and a first annular bead and a second annular bead designed to allow the tire to be mounted to a mounting support such as a rim, together with first and second side walls connecting the crown to the first and second bead, respectively, wherein the crown, the first and second side walls, and the first and second beads together form a wall having a concave inner surface that defines the cavity of the tire, and the tool comprises a radially outer crown zone having a shape conjugate to the inner surface of the tire wall and suitable for receiving components that form the crown of the tire for this purpose, and first lateral zones on both axial sides of the crown zone that are folded toward the central axis and suitable for receiving components that form the first side wall and the first bead, and second lateral zones that are folded toward the central axis and are suitable for receiving components that form the first side wall and the first bead The tool is characterized in that the core has a donut-shaped core having a convex outer surface called a “receiving surface” around its central axis, which is provided with a second lateral zone suitable for receiving the side wall and components forming the second bead, so that the core embodies a volume called a “reserved volume” that is externally separated by the receiving surface and corresponds to the cavity of the tire, and the core has a plurality of passages that extend inside the reserved volume below the receiving surface and open above the receiving surface, so that each of the passages connects the crown zone of the receiving surface to one of the first and second lateral zones, so that the core can receive reinforcing elements called “stays” inside the passages, each designed to be permanently incorporated into the structure of the tire and extending into the cavity of the tire and located at the crown of the tire, connecting crown fixing points located at lateral fixing points located at one of the side wall or bead of the tire.

[0006] Advantageously, the use of the core according to the present invention allows for positioning the stay in a desired location within the volume secured by the core, and as a result in a region of space that will subsequently become the cavity of the tire after the tire is formed and the core is removed.

[0007] Advantageously, while positioning the stays within the core, a portion of each stay is positioned inside the corresponding passage and thus within the region of space corresponding to the future cavity of the tire, while the ends of the stays protrude outside the passage on the receiving surface.

[0008] When the various rubber-based components that form the tire wall are then laid on the receiving surface of the core, for example by spiral winding of a continuous strip, the ends of each stay are thus immediately and permanently incorporated into the structure of the tire wall, while the middle portion of the stay in question, located in the passage, is set back from the receiving surface and therefore remains separated from the tire wall during and after the laying of the components that form the tire wall, i.e., preferably from the beginning, the middle portion of the stay is in a position that will permanently occupy within the tire cavity.

[0009] In addition, since the core has a donut shape corresponding to the desired final shape of the tire, the tire wall is advantageously formed directly as desired in a manner known to itself by simply laying the components that form the tire wall on the core.

[0010] The core supporting the tire is then placed in a mold to cure the tire, which allows the rubber-based components of the tire's walls to be vulcanized. After this curing process, the core is separated from the tire, meaning the tire cavity is released, leaving the stay permanently in place within the cavity.

[0011] Advantageously, the tools according to the present invention make it possible to obtain a properly molded tire with a stay from the outset and reproducibly, without any risk of inaccurate positioning or damage to the stay during tire manufacturing.

[0012] Further objects, features, and advantages of the present invention will become apparent in more detail when reading the following description and with the assistance of the accompanying drawings, which are provided purely as non-limiting figures. [Brief explanation of the drawing]

[0013] [Figure 1A] An example of a tire with stays manufactured according to the present invention is shown, where the crown fixing point and lateral fixing point of each stay are located at the same azimuth angle with respect to the tire's central axis, and the view is a cross-sectional view in a radial plane in which the stays extend along a radial plane containing the tire's central axis. [Figure 1B] An example of a tire with stays manufactured according to the present invention is shown, in which the crown and lateral fixing points of each stay are located at the same azimuth angle with respect to the tire's central axis, and the stay extends along a radial plane containing the tire's central axis. [Figure 2A] Another embodiment of a tire with stays manufactured according to the present invention is shown, in which the crown and lateral attachment points of each stay in the tire are angularly offset from each other with respect to the tire's central axis, and the tire also has two sets of stays in each of its hemispheres, the first set having attachment points angularly offset in one direction and the second set having attachment points angularly offset in the other direction, so that the stays intersect in a cross shape within a single hemisphere. [Figure 2B] Another embodiment of a tire with stays manufactured according to the present invention is shown, in which the crown and lateral attachment points of each stay in the tire are angularly offset from each other with respect to the tire's central axis, and the tire also has two sets of stays in each of its hemispheres, the first set having attachment points angularly offset in one direction and the second set having attachment points angularly offset in the other direction, so the stays in a single hemisphere intersect in a cross shape in a fractured perspective view along a radial plane. [Figure 3A]This is an exploded perspective view showing an annular subassembly forming the central ring of the core according to the present invention, the central ring forming the central portion of the crown zone suitable for receiving components that form the crown of the tire, the central ring being angularly subdivided into sectors, the sectors being alternately arranged and called arched segments and the sectors being called keys designed to lock the arched segments into place. [Figure 3B] This is an annular subassembly showing the central ring of the core according to the present invention, the central ring forming the central portion of the crown zone suitable for receiving components that form the crown of the tire, the central ring being angularly subdivided into sectors, the sectors being alternately arranged and called arched segments and the sectors being called keys designed to lock the arched segments into position. [Figure 4A] Figures 3A and 3B show a tool according to the present invention, comprising a central ring, on which two annular subassemblies called “lugs” are mounted. These lugs are each suitable for receiving components that form the sidewall of a tire and contain passages for stays in the form of grooves oriented along the radial plane to manufacture a tire as shown in Figures 1A and 1B. To facilitate the dismantling and extraction of the core from the tire, each lug is angularly subdivided into sectors, alternatingly forming arcuate segments and keys in a partially disassembled perspective view. [Figure 4B] Figures 3A and 3B show a tool according to the present invention, comprising a central ring, on which two annular subassemblies called “lugs” are mounted. These lugs are each suitable for receiving components that form the sidewall of a tire and contain passages for stays in the form of grooves oriented along the radial plane to manufacture a tire as shown in Figures 1A and 1B. To facilitate the dismantling and extraction of the core from the tire, each lug is angularly subdivided into sectors, forming alternating arcuate segments and keys, in an assembled perspective view. [Figure 4C]Figures 3A and 3B show a tool according to the present invention, comprising a central ring, on which two annular subassemblies called “lugs” are mounted, each lug being suitable for receiving components that form the sidewall of a tire, and containing passages for stays in the form of grooves oriented along the radial plane to manufacture a tire as shown in Figures 1A and 1B, and each lug is angularly subdivided into sectors, alternately forming arcuate segments and keys, to facilitate the dismantling and extraction of the core from the tire, and for ease of depiction, the left and right halves of the figure correspond to cross-sections along two separate radial planes that are slightly offset in azimuthal angles from each other with respect to the central axis of the core, and it should be noted here that the half located to the left of the equatorial plane passes through the hollow portion of the groove, while the half located to the right of the equatorial plane passes through the solid sidewall that defines the groove. [Figure 5A] Figures 3A and 3B show a tool according to the present invention equipped with a central ring, on which two annular subassemblies called “lugs” are mounted. These lugs are each suitable for receiving components that form the sidewall of a tire, and to manufacture a tire as shown in Figures 2A and 2B, they contain passages for stays in the form of cross-intersecting grooves. Figures 4A-4C are a partially disassembled perspective view in which each lug is angularly subdivided into sectors, alternating with arcuate segments and keys, to facilitate the disassembly and extraction of the core from the tire. [Figure 5B] Figures 3A and 3B show a tool according to the present invention with a central ring, on which two annular subassemblies called “lugs” are mounted, each of which is suitable for receiving components that form the sidewall of a tire, and in order to manufacture a tire as shown in Figures 2A and 2B, here it contains passages for stays in the form of cross-intersecting grooves, and in an assembled perspective view, as in the variation shown in Figures 4A-4C, each lug is angularly subdivided into sectors, alternatingly forming arcuate segments and keys, in order to facilitate the dismantling and removal of the core from the tire, [Figure 5C]Figures 3A and 3B show a tool according to the present invention equipped with a central ring, on which two annular subassemblies called “lugs” are mounted, each of which is suitable for receiving components that form the sidewall of a tire, and in order to manufacture a tire as shown in Figures 2A and 2B, here it contains passages for stays in the form of cross-intersecting grooves, and in detail cross-sectional views in the radial plane, each lug is angularly subdivided into sectors, alternating with arcuate segments and keys, in order to facilitate the dismantling and extraction of the core from the tire, as in the variations shown in Figures 4A-4C. [Figure 6A] Figures 4A–4C show a variation of a radially grooved tool with a barrier device suitable for preventing the rubber base components of the tire from entering the grooves. For this purpose, the barrier device comprises a first set of masking elements formed of sector shells that cover the lug sectors, each following the curve of the shoulder portion that forms the transition between the lateral zone and the crown zone of the lug, masking the corresponding grooves, and also comprising a second set of masking elements that have annular bands positioned at the transition between each lug and the center ring, covering the grooves in the crown zone. (Partially exploded perspective view) [Figure 6B] Figures 4A–4C show a variation of a radially grooved tool with a barrier device suitable for preventing the rubber base components of the tire from entering the grooves. For this purpose, the barrier device comprises a first set of masking elements formed of sector shells that cover the lug sectors, each following the curve of the shoulder portion that forms the transition between the lateral zone and the crown zone of the lug, masking the corresponding grooves, and also comprising a second set of masking elements that have annular bands positioned at the transition between each lug and the center ring, covering the grooves in the crown zone. (Assembled perspective view) [Figure 6C]Figure 4A-4C shows a variation of the radially grooved tool with a barrier device suitable for preventing the rubber-based components of the tire from entering into the grooves. For this purpose, the barrier device comprises a first set of masking elements formed by sector shells that each cover a lug sector following the curve of the shoulder that forms the transition between the lateral zone and the crown zone of the lug, masking the corresponding grooves, and also comprises a second set of masking elements comprising an annular band disposed at the transition between each lug and the central ring, covering the grooves within the crown zone. For ease of depiction, the left and right halves of the figure correspond to cross-sections along two separate radial planes with azimuths slightly offset from each other with respect to the central axis of the core, and it is noted here that the half located on the left side of the equatorial plane passes through the hollow portion of the groove, while the half located on the right side of the equatorial plane passes through the solid sidewall defining the groove, which is a detailed cross-sectional view within the radial plane. [Figure 7A] Perspective view of an exemplary embodiment of a lug key having a radial groove, the dividing line of which is parallel to the sagittal meridian plane of the lug, i.e., a radial plane passing through the center of the corresponding sector. [Figure 7B] Front view projected onto a plane perpendicular to the central axis of the core of an exemplary embodiment of a lug key having a radial groove, the dividing line of which is parallel to the sagittal meridian plane of the lug, i.e., a radial plane passing through the center of the corresponding sector. [Figure 7C] Cross-sectional view in the sagittal meridian plane of an exemplary embodiment of a lug key having a radial groove, the dividing line of which is parallel to the sagittal meridian plane of the lug, i.e., a radial plane passing through the center of the corresponding sector. [Figure 8A] Perspective view of an example of a lug bow segment complementing the lug key of FIGS. 7A-7C. [Figure 8B] Front view projected onto a plane perpendicular to the central axis of the core of an example of a lug bow segment complementing the lug key of FIGS. 7A-7C. [Figure 8C] Cross-sectional view in the sagittal meridian plane of the lug bow segment, i.e., a radial plane passing through the center of the corresponding sector, of an example of a lug bow segment complementing the lug key of FIGS. 7A-7C. [Figure 9A] A perspective view showing a modification of the key of FIGS. 7A - 7C with a recess suitable for receiving and positioning a masking shell covering a groove. [Figure 9B] A front view projected onto a plane perpendicular to the central axis of the core showing a modification of the key of FIGS. 7A - 7C with a recess suitable for receiving and positioning a masking shell covering a groove. [Figure 9C] A sectional view in a sagittal meridian plane corresponding to a radial plane passing through the center of the corresponding sector showing a modification of the key of FIGS. 7A - 7C with a recess suitable for receiving and positioning a masking shell covering a groove. [Figure 10] A partial front view projected onto a plane perpendicular to the central axis of the core showing an annular lug obtained from the assembly of the lug key of FIGS. 7A - 7C and the lug bow segment of FIGS. 8A - 8C. [Figure 11A] A perspective view showing a lug key having a cross - intersecting groove suitable for a cross - intersecting stay, the groove being separated by transverse walls generated in the overall axial direction vectorially collinear with the central axis, i.e., parallel to the central axis. [Figure 11B] A front view projected onto a plane perpendicular to the central axis of the core showing a lug key having a cross - intersecting groove suitable for a cross - intersecting stay, the groove being separated by transverse walls generated in the overall axial direction vectorially collinear with the central axis, i.e., parallel to the central axis. [Figure 11C] A sectional view in a sagittal meridian plane showing a lug key having a cross - intersecting groove suitable for a cross - intersecting stay, the groove being separated by transverse walls generated in the overall axial direction vectorially collinear with the central axis, i.e., parallel to the central axis. [Figure 12A] A perspective view of a lug bow segment with a cross - intersecting groove complementing the key of FIGS. 11A - 11C. [Figure 12B] A front view projected onto a plane perpendicular to the central axis of the core of a lug bow segment with a cross - intersecting groove complementing the key of FIGS. 11A - 11C. [Figure 12C]Figures 11A-11C show sagittal meridional cross-sectional views of a lag-shaped segment with a cross-groove complementing the key. [Figure 13A] This perspective view shows a lug key with a cross-shaped groove suitable for a cross-shaped stay, and in this case, the side walls of the groove are formed diagonally in the overall direction. [Figure 13B] This shows a lug key with a cross-shaped groove suitable for a cross-shaped stay, and in this case, it is a front view projected onto a plane perpendicular to the central axis of the core, showing a lug key in which the lateral walls of the groove are formed diagonally in the overall direction. [Figure 13C] This diagram shows a lug key with a cross-shaped groove suitable for a cross-shaped stay, and in this case, it shows a lug key where the lateral walls of the groove are formed diagonally in the overall direction, projected from the outside of the core onto a plane perpendicular to the diagonal direction. [Figure 13D] This is a sagittal meridional cross-section of a sector showing a lug key having a cross-groove suitable for a cross-groove stay, where the lateral walls of the groove are formed obliquely in the overall direction. [Figure 14A] This figure, similar to Figure 13A, shows a lag-shaped segment with a cross-shaped groove separated by walls generated diagonally in the overall direction, complementing the key in Figure 13A. [Figure 14B] This figure, similar to Figure 13B, shows a lag-shaped segment with a cross-shaped groove separated by walls generated diagonally in the overall direction, complementing the key in Figure 13B. [Figure 14C] This figure, similar to Figure 13C, shows a lag-shaped segment with a cross-shaped groove separated by walls generated diagonally in the overall direction, complementing the key in Figure 13C. [Figure 14D] This figure shows a lag-shaped segment with a cross-shaped groove separated by walls generated diagonally in the overall direction, similar to Figure 13D, complementing the key in Figure 13D. [Figure 15A] Figures 13A to 13D show the deformation of the lug key, and in this deformation, recesses extending between solid walls are provided on the inner surface of the lug key to reduce its weight and thus its thermal inertia. These are perspective views. [Figure 15B]Figures 13A to 13D show the deformation of the lug key, and these deformations are sagittal meridional cross-sections showing recesses extending between solid walls formed by grooves on the inner surface of the lug key in order to reduce the weight of the lug key and thus reduce its thermal inertia. [Figure 15C] Figures 13A to 13D show the deformation of the lug key. This deformation is a projection from the inside of the core radially, showing a recess extending between solid walls, where grooves are formed on the inner surface of the lug key to reduce its weight and thus its thermal inertia. [Figure 16A] These are schematic diagrams of the geometric principles for generating dividing lines applicable to lug keys with cross-grooves having walls defined by the diagonal overall direction, such as the lug keys shown in Figures 13A-13D and 15A-15C. [Figure 16B] These are schematic diagrams of the geometric principles for generating dividing lines applicable to lug keys with cross-grooves having walls defined by the diagonal overall direction, such as the lug keys shown in Figures 13A-13D and 15A-15C. [Figure 16C] These are schematic diagrams of the geometric principles for generating dividing lines applicable to lug keys with cross-grooves having walls defined by the diagonal overall direction, such as the lug keys shown in Figures 13A-13D and 15A-15C. [Figure 16D] These are schematic diagrams of the geometric principles for generating dividing lines applicable to lug keys with cross-grooves having walls defined by the diagonal overall direction, such as the lug keys shown in Figures 13A-13D and 15A-15C. [Figure 17] These are partial perspective views showing lugs obtained from assemblies of lug keys and lug arch segments, where the grooves and dividing lines are obtained in the diagonal overall direction, as in the case of lug sectors in Figures 13A-13D, 14A-14D, or 15A-15C, at a viewing angle corresponding to the diagonal overall direction. [Figure 18A]This perspective view shows a modified embodiment of a lug key with a cross-intersecting groove, in which a dividing line is generated diagonally in the overall direction along a zigzag cutting line that starts from a base profile corresponding to a broken line formed on the receiving surface by the staggered edges of a quadrilateral that follow each other from the crown zone to the lateral zone, defining the cross-intersecting groove on the receiving surface. [Figure 18B] This diagram shows a modified embodiment of a lug key with a cross-groove, in which a projection of the cross-groove onto the lateral wall of the cross-groove is shown, in which a dividing line is generated diagonally along a zigzag cutting line starting from the base profile corresponding to a broken line formed on the receiving surface by the alternating sides of a quadrilateral that follow each other from the crown zone to the lateral zone, defining the cross-groove on the receiving surface. [Figure 19] Figures 18A and 18B show a partial perspective view of a lug obtained from an assembly of lug keys and lug arch-shaped segments, where the dividing line follows a zigzag cutting line, as in the lug keys, at a viewing angle corresponding to the overall oblique direction. [Figure 20A] This is a radial plane cross-sectional view of the extraction of a lug key from a tire by inclination following axial translational extraction movement within a tool equipped with a lug as shown in Figures 9A-9C, and a radial groove and masking shell as shown in Figures 6A-6C. [Figure 20B] This is a radial plane cross-sectional view of the extraction of a lug key from a tire by inclination following axial translational extraction movement within a tool equipped with a lug as shown in Figures 9A-9C, and a radial groove and masking shell as shown in Figures 6A-6C. [Figure 20C] This is a radial plane cross-sectional view of the extraction of a lug key from a tire by inclination following axial translational extraction movement within a tool equipped with a lug as shown in Figures 9A-9C, and a radial groove and masking shell as shown in Figures 6A-6C. [Figure 20D] This is a radial plane cross-sectional view of the extraction of a lug key from a tire by inclination following axial translational extraction movement within a tool equipped with a lug as shown in Figures 9A-9C, and a radial groove and masking shell as shown in Figures 6A-6C. [Figure 20E] This is a radial plane cross-sectional view of the extraction of a lug key from a tire by inclination following axial translational extraction movement within a tool equipped with a lug as shown in Figures 9A-9C, and a radial groove and masking shell as shown in Figures 6A-6C. [Figure 20F] This is a radial plane cross-sectional view of the extraction of a lug key from a tire by inclination following axial translational extraction movement within a tool equipped with a lug as shown in Figures 9A-9C, and a radial groove and masking shell as shown in Figures 6A-6C. [Figure 21A] These are partial perspective cross-sections showing the extraction of a lug key in the radial plane, following the extraction movement shown in Figures 20A to 20F, and more specifically, the steps shown in Figures 20C, 20D, and 20E. [Figure 21B] These are partial perspective cross-sections showing the extraction of a lug key in the radial plane, following the extraction movement shown in Figures 20A to 20F, and more specifically, the steps shown in Figures 20C, 20D, and 20E. [Figure 21C] These are partial perspective cross-sections showing the extraction of a lug key in the radial plane, following the extraction movement shown in Figures 20A to 20F, and more specifically, the steps shown in Figures 20C, 20D, and 20E. [Figure 22A] This is a cross-sectional view of the extraction of a type of lug key shown here in the radial plane, following an oblique extraction movement carried in the oblique direction throughout, which is contained in the sagittal meridional plane of the lug key and used to generate the transverse walls of the groove of the lug key. [Figure 22B] This is a cross-sectional view of the extraction of a type of lug key shown here in the radial plane, following an oblique extraction movement carried in the oblique direction throughout, which is contained in the sagittal meridional plane of the lug key and used to generate the transverse walls of the groove of the lug key. [Figure 22C] This is a cross-sectional view of the extraction of a type of lug key shown here in the radial plane, following an oblique extraction movement carried in the oblique direction throughout, which is contained in the sagittal meridional plane of the lug key and used to generate the transverse walls of the groove of the lug key. [Figure 23] This partial perspective view shows a modified embodiment in which, after the barrier device has positioned the stays in the groove, a set of shims are inserted into the groove to seal it flush with the receiving surface. [Figure 24] Figures 4A-4C show detailed cross-sectional views of the stay arrangement within the core before the tire wall is manufactured, in a meridional plane passing through the center of the lug grooves in the core. [Figure 25] This schematic diagram illustrates the manufacturing principle of a stay using a single continuous thread that forms a serpentine shape and engages with a continuous passage, showing that the loops forming the staggered extrema of this serpentine shape are suitable for forming the lateral fixing points of the stay. [Modes for carrying out the invention]

[0014] The present invention relates in particular to a tool 1 as shown in Figures 4A, 4B, 4C, 5A, 5B, 5C, and 6A, 6B, and 6C, which is suitable for manufacturing donut-shaped tires 2 as shown in Figures 1A, 1B, 2A, and 2B.

[0015] Such a tire 2 preferably forms an air tire suitable for mounting on a vehicle's wheel in order to provide contact between the vehicle and the ground.

[0016] The tire 2 has a shape that exhibits rotational symmetry around an axis called the "central axis" Z2, which is substantially corresponding to the rotation axis of the wheel. This central rotation axis Z2 defines three directions that are conventionally used by those skilled in the art: the axial direction, the radial direction, and the circumferential direction.

[0017] "Axial direction" refers to the direction that is vectorially collinear with the tire's central axis Z2, that is, the direction parallel to the tire's axis of rotation.

[0018] "Radial direction" refers to the direction extending along the radius of the tire, that is, any direction that intersects and is perpendicular to the central axis Z2.

[0019] "Circumferential direction" refers to the direction perpendicular to the axial direction and the radius of the tire. Therefore, in a plane perpendicular to the central axis Z2, it corresponds to the tangent to a circle centered on the tire's axis of rotation.

[0020] The "meridian plane" P_MER, or "radial plane," refers to a plane parallel to and containing the central axis Z2. Therefore, such a meridian plane is perpendicular to the circumferential direction.

[0021] The "equator plane" P_EQ is a plane perpendicular to the central axis Z2 and passing through the outermost radial point of the tire, preferably located midway between the outermost axial points of the tire. Thus, the equatorial plane divides the tire 2 axially into two preferably substantially equal donut-shaped halves, which by analogy to a sphere are called "hemispheries".

[0022] The tire 2 comprises a crown 3 suitable for forming a tread in a manner known in itself, a first annular bead 4 and a second annular bead 5 designed so that the tire 2 can be attached to a mounting support such as a rim, and a first side wall 6 and a second side wall 7 connecting the crown 3 to the first bead 4 and the second bead 5, respectively.

[0023] Typically, in the meridional plane P_MER, the boundary between the crown 3 and the side walls 6 and 7 can be considered to correspond to the outermost point in the axial direction of the outer surface of the tire 2, where the angle between the tangent to the outer surface of the tire 2 and the line parallel to the central axis Z2 is equal to 30 degrees.

[0024] The crown 3, the first and second side walls 6 and 7, and the first and second beads 4 and 5 together form a wall 8 having a concave inner surface 8 that defines the cavity 9 of the tire 2.

[0025] In fact, the tire cavity 9 is annular, which is advantageous as it forms the expansion cavity of the tire 2 and is suitable for receiving a pressurized fluid such as air to support the crown 3 of the air tire 2 against the rim.

[0026] Preferably, as can be clearly seen in Figures 1A and 2A, the beads 4 and 5 are positioned axially recessed from the axially protruding portions of the corresponding sidewalls 6 and 7, i.e., the beads 4 and 5 are closer to the equatorial plane P_EQ than the sidewalls 6 and 7 to which the beads are connected. Thus, between the crown 3 and the beads 4 and 5, the sidewalls 6 and 7 generally curve outward in cross-section at the meridional plane P_MER, forming a profile in which the ends forming the beads 4 and 5 are axially recessed, so that the cavity 9 is substantially Ω (uppercase omega) shaped in cross-section at the meridional plane.

[0027] The present invention provides a donut-shaped core 10 having a convex outer surface 10_out called a “receiving surface” 10_out around its central axis Z10, the receiving surface 10_out having a shape conjugate to the inner surface 8_in of the tire wall 8, and for this purpose comprises a radially outer crown zone 11 suitable for receiving components that form the crown 3 of the tire 2, a first lateral zone 12 folded back toward the central axis Z10 of the core on both axial sides of the crown zone and suitable for receiving components that form the first side wall 6 and the first bead 4, and a second lateral zone 13 folded back toward the central axis Z10 and suitable for receiving components that form the second side wall 7 and the second bead 5.

[0028] As a result, core 10 embodies a volume called the "secured volume," which is externally determined by the receiving surface 10_out and corresponds to the cavity 9 of tire 2.

[0029] The core 10 occupies a volume corresponding to the shape and dimensions of the cavity 9 during tire manufacturing, and can therefore be temporarily reserved, and this volume becomes the cavity 9 of the tire 2 when the core 10 is removed from the tire 2 during the demolding operation that completes the manufacturing cycle of the tire 2.

[0030] In practice, the central axis Z10 of the core 10, which forms a ring around it, coincides with the central axis Z2 of the tire 2 manufactured on the core 10. Therefore, for the sake of explanation, both can be referred to as the "central axis."

[0031] In this invention, the core 10 has a plurality of passages 15 that extend downward from the receiving surface 10_out and open above the receiving surface 10_out, so that each of the passages 15 connects the crown 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 reinforcing elements 16 called “stays” 16 inside the passage 15, and these stays are designed to be permanently incorporated into the structure of the tire 2, each extending into the cavity 9 of the tire and connecting a crown fixing point 17 located at the crown 3 of the tire 2 to a lateral fixing point 18 located at one of the side walls 6, 7 or the bead 4, 5 of the tire 2.

[0032] The passage 15 corresponds to a void formed inside the secured volume in the core 10, so that it receives the stays 16, and each stay 16 can first pass through the receiving surface 10_out to enter the secured volume, and then pass through the lateral zones 12, 13 to exit the secured volume, here entering the crown zone 11, or vice versa.

[0033] The stay 16 can have different configurations, in particular, various orientations, without departing from the scope of the present invention.

[0034] Therefore, in one possible embodiment corresponding to Figures 1A and 1B, the crown and lateral fixing points 17, 18 of each stay 16 are located at the same azimuth angle with respect to the tire's central axis Z2, so that the stay 16 extends along the radial plane containing the tire's central axis Z2.

[0035] In another possible embodiment corresponding to Figures 2A and 2B, the crown and lateral attachment points 17, 18 of each stay 16 are angularly offset relative to each other with respect to the tire's central axis Z2 in order to create an inclined stay 16. In this case, more preferably, the tire 2 may have two sets of stays 16 in a single hemisphere, preferably in each of its two hemispheres, such that the first set of stays 16 each have an angular offset in a first direction, e.g., clockwise, between its crown attachment point 17 and lateral attachment point 18, while the second set of stays 16 each have an angular offset in the opposite second direction, e.g., counterclockwise, between its crown attachment point 17 and lateral attachment point 18, so that in a single hemisphere, the first set of stays 16 and the second set of stays 16 intersect at a cross.

[0036] Preferably, all lateral fixing points 18 of the stay 16 within a single hemisphere are located at the same transverse coordinate along the central axis Z2; that is, it is preferable that the stay 16 within a single hemisphere emerges from the wall 8 of the tire 2 along a single imaginary line corresponding to the intersection of the inner surface 8_in of the wall 8 and a plane perpendicular to the central axis Z2.

[0037] The same applies to the crown anchoring points 17 of the stay 16 in a single hemisphere, which are all preferably located at the same transverse coordinate along the central axis Z2, separate from the transverse coordinate of the transverse anchoring points 18.

[0038] In addition, with respect to a given stay 16 or all of the stays 16, it is preferable that the transverse coordinate of the crown fixing point 17 is closer to the equatorial plane P_EQ than the transverse coordinate of the transverse fixing point 18.

[0039] In any case, that is, whether there are stays 16 contained in the radial plane as shown in Figure 1A, or whether there are inclined and / or cross-intersecting stays 16 as shown in Figure 2A, it is preferable that each stay 16 is contained in a single hemisphere in that there are no stays 16 that cross the equatorial plane P_EQ inside the cavity 9 of the tire, that is, the lateral fixing point 18 and crown fixing point 17, which form both ends of a single section of stay 16 that extends continuously within the cavity 9 and thus form two continuous points where the stay 16 emerges from the wall 8, passes through the cavity 9, then exits the cavity 9 and re-enters the wall 8, are located in the same hemisphere on the same side of the equatorial plane P_EQ. This makes it possible to simplify the structure and demolding operation of tool 1 in particular.

[0040] Preferably, whether there are stays 16 contained in the radial plane as shown in Figure 1A, or whether there are inclined and / or cross-intersecting stays 16 as shown in Figure 2A, each stay 16 is suitable for operation in a tensile state and is therefore suitable for connecting the crown fixing point 17 to the corresponding lateral fixing point 18 along a straight segment, and in a stationary tire 2, a taut or nearly taut chord is geometrically formed below the arc formed by the inner surface 8_in of the wall 8 between the crown fixing point 17 and the lateral fixing point 18, so that the stays 16 resist the separation of the fixing points 17, 18 and thus increase the lateral rigidity of the tire.

[0041] In addition, it is preferable that a set of stays 16 be evenly distributed around the central axis Z2 at a constant repeating angular pitch P16.

[0042] This repeating angle pitch P16 is preferably 0.5 to 5 degrees, preferably 0.75 to 3 degrees, particularly 1 to 3 degrees, and equal to, for example, 1.5 degrees. Thus, each set of stays 16 can include 72 to 480 or even 720, preferably 120 to 360, and as a preferred example, 240 stays.

[0043] These repeating angle pitch P16 values ​​apply in particular to passenger car tires 2 as defined by the European Tire and Rim Technology Organization, i.e., in accordance with the ETRTO 2020 standard, and more specifically to tires intended to be mounted on rims with a mounting diameter of at least 12 inches, preferably at least 16 inches, and at most 24 inches, preferably at most 22 inches.

[0044] In practice, the repeating angle pitch P16 described above makes it possible to find a satisfactory compromise between a number of stays 16 large enough to obtain effective stiffening of the tire 2 even if one or more stays 16 break, and a number of stays 16 moderate enough to allow a corresponding number of passages 15 to be placed in the core 10 without excessively weakening the structure of the core 10 or complicating the demolding operation.

[0045] As an example, in the case of the aforementioned diameter for the tire 22, if the repeating pitch P16 of 1.5 degrees takes the arc length around the central axes Z2, Z10, then every 5 mm to 10 mm, for example every 8 mm, one stay 16 and thus one stay passage 15 are positioned at the maximum diameter of the inner surface 8_in of the wall 8 of the tire 2, or in an equivalent manner, at the maximum diameter of the outer surface of the core 10 that forms the receiving surface 10_out in the crown zone 11.

[0046] Preferably, the stay 16 is made of one or more fibrous elements, and its maximum lateral dimension is small by at least 1 / 10, at least 1 / 20, or at least 1 / 50 of the visible length of the portion of the stay 16 extending into the cavity 9, i.e., the length of the stay 16 between the crown fixing point 17 and the corresponding lateral fixing point 18.

[0047] Therefore, the stay 16 can be formed from single-strand or multi-strand threads made of fabric material, polymer material such as aramid, or metallic material. In one possible embodiment, the stay 16 is made from a composite thread manufactured using fiberglass and resin.

[0048] Advantageously, regardless of the configuration of the stay 16, the core 10 according to the present invention allows the stay 16 to be inserted into the volume secured by the core 10 and thus into the space that will become the cavity 9 of the tire 2, in a distribution and arrangement that substantially or precisely corresponds to the distribution and arrangement of the finished tire 2 ready to be mounted on the rim, before the tire 2 is formed, because even if the core 10 is removed, the stay 16 remains firmly connected to the tire 2 in a fixed, desirable location within the cavity. Thus, by using the core 10 according to the present invention, the tire 2 is ensured to have a well-controlled and repeatable configuration from one tire 2 to another.

[0049] In addition, during the laying of the components forming the tire wall 8, there is no risk of the stay 16 being accidentally moved, pulled out, or damaged during the process of manufacturing the tire wall 8 so that it is thus protected within the passage 15 of the core 10.

[0050] From an absolute standpoint, it can be assumed that all or part of the core 10, in particular the portion of the core 10 that temporarily fills the tire cavity 9 and defines the passage 15, is made from a material that is soluble, fusible, vaporizable (sublimable), or otherwise decomposable without damaging the tire 2, so that after the manufacture and curing of the tire 2, the portion of the core can be destroyed according to instructions and discharged in the form of a fluid or granules at demolding without damaging the tire 2 or in particular the stay 16. Accordingly, a core 10 that forms a partially or completely lost pattern, which is replaced with each manufacturing cycle, similar to casting, can be used, especially to facilitate demolding. Within such a core that forms a partially or completely lost pattern, the passage 15 may optionally have a tubular shape, and its cross-section is closed over at least a portion of the free length of the stay or over the entire free length of the stay 16, i.e., around the stay 16 from the lateral fixing point 18 to the crown fixing point 17.

[0051] However, it is particularly preferable that the passage 15 be arranged in a demoldable open shape, thereby making it possible to manufacture a permanent and reusable core 10 that can be pulled out from the tire 2 after the tire 2 has been manufactured without damaging the stay 16 and reused to manufacture the next tire.

[0052] Therefore, it is preferable that the passage 15 for the stay 16 is formed by a groove 15 cut out from the receiving surface 10_out in the thickness direction of the secured volume, such that it has a continuous opening along the profile of the receiving surface 10_out from the crown zone 11 to the lateral zones 12, 13.

[0053] Advantageously, each groove 15 forms a slot-shaped opening that extends along the entire length of the receiving surface 10_out from the lateral fixing point 18 of the stay 16 to the crown fixing point 17 of the stay 16, so that the stay 16 can be engaged in the passage simply by sliding the stay 16 into the groove 15 from the outside of the core 10 before laying the components that form the wall 8 of the tire 2, and thus the stay passes through the receiving surface 10_out and falls into the secured volume toward the central axis Z10 of the core.

[0054] Advantageously, after the components forming the wall 8 of the tire 2 are laid on the receiving surface 10_out so that the wall 8 covers the groove 15, the core 10 can be pulled out from the inside of the tire 2, thereby gradually exposing the stay 16, which at this point is fixed to the wall 8 and thus incorporated into the tire 2, from the opening of the groove 15 of the disengaged core, and thus remaining in a permanent position within the cavity 9 of the tire 2.

[0055] For the sake of explanation and to avoid cluttering the diagram, the passage 15 for the stay 16 and the groove 15 that constitutes a preferred specific shape of the passage 15 for the stay 16 are denoted by the same reference numeral 15.

[0056] Preferably, as seen particularly in Figures 4C, 5C, 6C, 7C, 8C, 9C, 11C, 12C, 13C, 14C, 15B, 18A, 20A, 21A, and 24, the groove 15 is a dead end, that is, the groove 15 has a solid bottom 19 located below the receiving surface 10_out, which extends from a first opening of the groove 15 that opens over the lateral zones 12, 13 of the receiving surface 10_out to a second opening of the groove 15 that opens over the crown zone 11 of the receiving surface 10_out.

[0057] Therefore, when in a fixed position within the groove 15, the stay 16 is radially positioned, and more specifically, contained between the solid bottom 19 and the opening of the groove 15 located radially with respect to the central axis Z10 of the core and the receiving surface 10_out. The stay 16 can be located "above" the solid bottom 19, i.e., at a non-zero radial distance from the solid bottom 19 beyond the solid bottom 19 with respect to the central axis Z10, or it can rest on the solid bottom 19, in which case, advantageously, the solid bottom 19 functions as a guide and support for the stay 16 during the manufacture of the tire 2.

[0058] Preferably, the depth of the passage 15 relative to the receiving surface 10_out, more specifically the depth of the groove 15, and therefore more specifically the distance separating the solid bottom 19 of the groove 15 from the receiving surface 10_out is sufficient, and each of the passages 15 allows the stay 16 to follow a path along a straight segment within the passage 15 that directly connects the lateral fixing point 18 to the crown fixing point 17. Thus, the stay 16 can assume its functional configuration within the passage 15, in this case within the groove 15, without interfering with, being deformed by, or deviating from the passage 15, and this functional configuration allows the stay 16 to form a chord connecting the ends of the arc drawn by the tire wall 8 between the lateral fixing point 18 and the crown fixing point 17 in the shortest path, so that with the tire 2 released from the core 10, the stay 16 can effectively function in a tensile state like a tension rod between the lateral fixing point 18 and the crown fixing point 17.

[0059] The passages 15, in this case the grooves 15, will of course be arranged azimuthally and preferably evenly distributed around the central axis Z10 at a constant repeating angular pitch P16 equal to, for example, 1.5 degrees, with respect to the stays 16 as described above.

[0060] The width W15 of the groove 15 is preferably selected as a function of compromise between i) the need to provide a functional clearance between the stay 16 and the side wall defining the groove 15, taking into account the width (diameter) of the stay 16, so as to allow the stay 16 to be inserted into the groove 15 and then the core 10 to be withdrawn from the tire 2, and thus the stay 16 to be withdrawn from the groove 15 without trapping or damaging the stay 16, and ii) the need to provide high-quality support to the components of the tire 2 laid on the receiving surface 10_out without weakening the core 10, and, if possible, to keep the opening and groove width W15 narrow enough to prevent the intrusion of materials forming the components of the tire 2 into the groove 15, and thus to prevent deformation or creep.

[0061] Therefore, the width W15 of the groove 15, particularly the width of the opening of the groove 15 on the receiving surface 10_out, is preferably 1.01 to 1.5 times the corresponding dimension of the cross-section of the stay 16, and more preferably the maximum dimension of the cross-section of the stay. In practice, if the stay is formed by threads of a single strand or multiple strands having a substantially circular cross-section, the dimension of the cross-section of the stay considered is the diameter of the circular cross-section of the threads.

[0062] Preferably, for the same reason, especially when the cross-section of the stay 16 is assumed to have a diameter of 0.25 mm to 2 mm, for example about 1 mm, the groove width W15 is selected to be 0.1 mm to 3 mm, preferably 0.3 mm to 2.2 mm, for example 1 mm to 1.8 mm, particularly at the opening on the receiving surface 10_out.

[0063] Preferably, all of the grooves 15 in a single hemisphere of the core 10, and more preferably all of the grooves 15 in the core 10, have the same width W15.

[0064] In one possible embodiment, as in the cases of Figures 4A-4C, 6A-6C, 7A-7C, 8A-8C, 9A-9C, 10, 20A-20F, 21A-21C, and 23, the groove 15 is generated along a radial plane containing the central axis Z10, allowing a stay 16 extending along the radial plane to be positioned within the tire 2, as in the case of the tire in Figures 1A and 1B.

[0065] Therefore, each groove 15 is contained within the radial plane that forms the sagittal meridian of the groove 15, i.e., the radial plane that intersects with the center of the azimuth sector occupied by the groove. The sagittal meridian planes of two grooves 15 directly adjacent to groove 15 are angularly separated from the sagittal meridian plane of groove 15 by a value equal to the iterative angular pitch P16 of the groove 15, and thus ultimately equal to the iterative angular pitch P16 of the stay.

[0066] Where applicable, each groove 15 in this arrangement can be produced by a saw cut that is parallel to the sagittal meridional plane of the groove and has a constant width equal to the desired width W15 of the groove 15.

[0067] In another possible embodiment, as in Figures 5A-5C, 11A-11C, 12A-12C, 13A-13D, 14A-14D, 15A-15C, 17, 18A and 18B, 19, and 22A-22C, grooves 15 are arranged in a cross shape on the receiving surface 10_out to form a grid, allowing the intersecting stays 16 to be positioned inside the tire 2, as in the case of the tires in Figures 2A and 2B.

[0068] By analogy and for the sake of explanation, the receiving surface 10_out is an indestructible surface (skewed surface), and therefore further forms a non-flat surface. The lattice units drawn by the openings of the cross-intersecting grooves 15 on the receiving surface 10_out, i.e., the basic units or "blocks," which are substantially rhombuses (i.e., substantially diamond shapes), can be described as "quadrilaterals." Furthermore, the material columns of the core 10 remaining between the continuous cross-intersecting grooves 15 can be described as "prisms" 20, and the bottom surfaces of these prisms 20 correspond to the aforementioned quadrilaterals, with their surfaces forming the side walls that define the grooves 15.

[0069] Due to a preferred feature that is applicable regardless of the nature and shape of the passage 15 for the stay, but is particularly advantageous when the passage 15 for the stay is formed by a groove 15, the core 10 comprises an assembly of several annular subassemblies 21, 22, 23, including the following, as seen particularly in Figures 4A, 4C, 5A, 5C, 6A, 6C, and 23: i) A first annular subassembly 21 called a "center ring" 21 that forms the central portion of the crown zone 11 of the receiving surface 10_out, wherein the central portion of the crown zone 11 is suitable for receiving one or more components that form the crown 3 of the tire 2, ii) A second annular subassembly 22 called a “left lug” 22, which is axially adjacent to the central ring 21, and which includes a portion of the crown zone 11 that axially extends the central portion of the crown zone 11 on the corresponding side of the central ring 21 together with the first lateral zone 12 of the receiving surface 10_out, and which encloses a groove 15 that forms a passage for a stay 16 that connects the first side wall 6 of the tire to the crown 3 of the tire, and iii) A third annular subassembly 23 called a “right lug” 23, which is axially adjacent to the center ring 21 on the opposite side of the center ring 21 from the side that receives the left lug 22, and which includes a portion of the crown zone 11 that axially extends the central portion of the crown zone 11 on the corresponding side of the center ring 21 together with a second lateral zone 13 of the receiving surface 10_out, and which encloses a groove 15 that forms a passage for a stay 16 that connects the second side wall 7 of the tire to the crown 3 of the tire.

[0070] The left lug 22, the center ring 21, and the right lug 23 are coaxial and are arranged around the central axis Z10.

[0071] The terms "left" and "right" are used for explanatory purposes only, to distinguish lugs 22 and 23 when necessary, and of course, do not predetermine the direction in which the tire 2 is mounted to the rim and / or vehicle.

[0072] Preferably, the central ring 21 does not have a passage 15 for the stay 16 and therefore preferably has a solid outer surface forming an annular central island that separates the grooves 15 of the left lug 22 and the right lug 23. Advantageously, such an arrangement facilitates demolding, and in addition, it allows the stay 16 to be locally passed through the receiving surface 10_out that receives the components of the tire wall 8 outside the central ring 21 and therefore radially outside the core 10, allowing the corresponding portion of the stay 16 to be easily incorporated into the wall 8, thus ensuring that the stay is securely fixed to the crown 3 of the tire 2.

[0073] Preferably, the crown portion of the central ring 21 forms a straight cylinder with a circular bottom centered on the central axis Z10.

[0074] In addition, the equatorial plane P_EQ is preferably included in the axial range covered by the central portion of the crown zone 11 of the central ring 21, and more specifically, is located at the center of that axial range, so the central portion of the crown zone 11, more generally the central ring 21, is subdivided into two parts that are equal to or symmetrical to each other with respect to the equatorial plane P_EQ.

[0075] Lugs 22 and 23 have a convex curved outer shape in a radial plane cross-section that provides a curved transition between the crown zone 11 and the corresponding lateral zones 12 and 13 of the receiving surface 10_out, the curvature of which follows the curvature with respect to the cavity 9 of the tire 2, and more specifically, the curvature with respect to the inner surface 8_in of the tire wall 8 in the zone that the wall 8 traces toward the outermost axial point of the side walls 6 and 7, together with the transition between the crown 3 and the side walls 6 and 7. Thus, lugs 22 and 23 form lobes that can occupy and temporarily fill the cavity 9 of the tire 2 during the manufacturing of the tire 2, and thus shape the cavity.

[0076] In this regard, please note that due to the recess of the cavity 9 and the axial constriction formed by the beads 4 and 5 relative to the side walls 6 and 7, the beads 4 and 5 are aligned in a radial line with the lugs 22 and 23, and therefore the lugs 22 and 23 form a portion of the core 10 that cannot be demolded by radial withdrawal.

[0077] As described above, in order to simplify the demolding operation, single-use left lugs 22 and / or right lugs 23 made from materials such as soluble, meltable, or sublimable materials can be used, which will form consumable components of the core 10 that will be replaced with each new cycle for manufacturing the tire 2. Such consumable components can be mounted on a reusable center ring 21.

[0078] However, the lugs 22 and 23, like the center ring 21, are preferably reusable after each manufacturing cycle, and for this purpose are made from a durable material such as an aluminum alloy.

[0079] For this purpose, the arrangement of tool 1 is provided that is suitable for disassembling the core 10, and more specifically for disassembling the subassemblies 21, 22, and 23 from the inside of the tire 2.

[0080] Preferably, as seen particularly in Figures 3A, 4A, 5A, 6A, and 10, the annular subassemblies 21, 22, 23, i.e., the central ring 21, left lug 22, and right lug 23, are each angularly divided azimuthally around the central axis Z10, forming sectors 24, 25, 26, 27, 28, 29, which alternate between sectors called “keys” 24, 26, 28, which are radially accessible from the inside with respect to the dismantling of the subassemblies 21, 22, 23 and are designed to be removed first, and sectors called “bow-shaped segments” 25, 27, 29, which are supported and locked in place by the keys 24, 26, 28 and are designed to be operated after being released by the removal of the keys 24, 26, 28.

[0081] As is clear from Figures 3A and 3B, the central ring 21 is thus divided into multiple ring keys 24 and ring arch-shaped segments 25.

[0082] The number of ring keys 24, equal to the number of ring arch segments 25, is selected to be large enough to allow for easy division and disassembly by centripetal radial pulling of the sectors 24, 25 forming the central ring 21, but also large enough so that the number of sectors 24, 25 is not unnecessarily large, and thus the assembly of the subassemblies 21 forming the central ring 21 is simplified. Accordingly, the number of ring keys 24 and therefore the number of ring arch segments 25 is preferably 4 to 6, and more preferably equal to 5, as in the cases of Figures 3A and 3B.

[0083] With regard to standardization and ease of assembly, it is preferable that all ring keys 24 are identical and therefore interchangeable. Similarly, it is preferable that all ring arch segments 25 are identical and therefore interchangeable.

[0084] Preferably, each ring key 24 is defined such that the sides forming the dividing line between the ring key 24 and two adjacent ring arch segments 25 are parallel to each other and parallel to the sagittal meridional plane of the ring key 24. In a preferred variation, each side has a non-zero tapering angle with respect to the sagittal meridional plane, preferably equal to 1 to 2 degrees, for example, 1.5 degrees, so that these two sides flare outwards as they approach the central axis Z10 radially, i.e., diagonally away from it, forming secant planes that move away from the sagittal meridional plane, and these secant planes have an opening angle between them equal to the sum of the respective tapering angles of the sides, here for example, 3 degrees if each side has a tapering angle of 1.5 degrees. This arrangement is advantageous because, whether the sides are parallel (taper angle equal to zero) or tapered (taper angle is not zero), it allows for centripetal radial withdrawal of the ring key 24 from the ring arch segments 25 on either side of the ring key 24. This withdrawal is performed by sliding the ring key 24 "plane to plane" against the ring arch segments 25 on either side of the ring key 24 in the case of precisely parallel sides, and with a slight misalignment in the case of tapered sides.

[0085] The ring arch segment 25, of course, forms a sector that complements the ring key 24 and is locked in place by the ring key 24 within the annular subassembly 21 that forms the central ring 21. By analogy from the field of architecture, the ring key 24, positioned and held by a common support (not shown), thus prevents the arc formed by the ring arch segment 25, and more generally by the continuity of the key 24 and the arch segment 25, from collapsing. The larger the tapering angle of the side of the ring key 24, the more robust and stable the support provided by the ring key 24 becomes.

[0086] In order to dismantle the central ring 21 during the demolding operation and pull it out of the tire 2, the ring key 24 is first pulled out by a centripetal radial pulling movement followed by an axial disengagement movement, which has the effect of releasing the ring arch segment 25, and then the ring arch segment 25 is pulled out by a centripetal radial pulling movement followed by an axial disengagement movement.

[0087] The central ring 21 preferably comprises a first tapered surface 32 supporting the left lug 22 and a second tapered surface 33 supporting the right lug 23 on either side of the central portion of the crown zone 11, so that the ring key 24 and thereafter the ring arc-shaped segment 25 can be pulled out radially and centripetically from the lugs 22 and 23 while the lugs 22 and 23 are still held within the cavity 9 of the tire 2.

[0088] The first and second tapered surfaces 32 and 33 preferably form a first inclined surface 32 and a second inclined surface, respectively, which are radially closer to the central axis Z10 than the passage 15 for the stay 16, and form a convex profile in cross-section in the radial plane including the central axis Z10 together with the central portion of the crown zone 11, as seen in Figures 4C, 5C, 6C, and 24.

[0089] Inside the core 10 assembled and used to manufacture tire 2, the central ring 21 is contained in a space that is set back radially from the stay 16 and set back from the lugs 22, 23, and sectors 24, 25 of the central ring 21 are capable of performing centripetal radial pull-out movements without interfering with the lugs 22, 23, which are still in place within the cavity of tire 2 while the lugs 22, 23 are still bound to tire 2 after tire 2 has hardened.

[0090] To prevent the walls of the groove 15 from excessively rubbing against the stay 16 or the stay from being pulled out when the lug sectors 26, 27, 28, and 29 are withdrawn, and more specifically when the lug keys 26 and 28 are withdrawn, each of the lug sectors 26, 27, 28, and 29 occupies some angular sector around a central axis Z10, which is relatively small but large enough to limit the number of lug sectors 26, 27, 28, and 29 that are assembled to produce each of the lugs 22 and 23.

[0091] In addition, for the sake of standardization and ease of assembly, it is preferable that each lug key 26, 28 of lugs 22, 23 be defined such that its value occupies an angular sector A26 whose value is all divisors of 360 degrees, and that its value is preferably equal to the value of the angular sector occupied by the other keys 26, 28 of the same lug.

[0092] Similarly, each arcuate segment 27, 29 of the lags 22, 23 preferably occupies an angular sector A27 whose value is a total divisor of 360 degrees, and its value is preferably equal to the value of the angular sector occupied by the other arcuate segments 27, 29 of the same lags 22, 23.

[0093] Preferably, as shown in Figure 10, when considering the radially outermost level of the receiving surfaces 10_out of the lug keys 26 and 28 with respect to the central axis Z10, the angular sector A26 occupied by each lug key 26 and 28 is preferably 9 degrees or more, preferably 36 degrees or less, more preferably 24 degrees or less, and even more preferably 18 degrees or less.

[0094] From an absolute standpoint, angle sectors A26 can be provided that are equal to 9, 15, 18, or 24 degrees, but in light of the dimensions of the assumed tire 2, more specifically in light of the corresponding maximum diameter of the receiving surface 10_out and the selected repeating angle pitch P16 (preferably 1.5 degrees here), a value of 9 degrees is preferred.

[0095] Similarly, at the maximum diameter of the receiving surface 10_out, the angular sector A27 occupied by each lug-shaped segment 27, 29 is preferably 9 degrees or more, preferably 36 degrees or less, more preferably 24 degrees or less, and even more preferably 18 degrees or less, selected from, for example, 24 degrees, 18 degrees, and 15 degrees, and more preferably 9 degrees.

[0096] Preferably, in order to facilitate the attachment of the lug sectors 26, 27, 28, and 29 to the central ring 21, the sector division of the left lug 22 is identical to the sector division of the right lug 23, and the azimuth angles coincide, so that each key 26 of the left lug 22 faces the key 28 of the right lug 23 and angularly overlaps it in the projection on the equatorial plane P_EQ, and similarly, each arcuate segment 27 of the left lug 22 faces the corresponding arcuate segment 29 of the right lug 23 and angularly overlaps it.

[0097] Note that by arbitrarily creating angle sectors A26 and A27 at 36 degrees, the angular division of lugs 22 and 23 will precisely match the angular division of the central ring 21.

[0098] In addition, independently of or in combination with the aforementioned absolute values ​​of the angular sectors A26 and A27, the number of grooves 15 per lug key 26, 28 and lug arch segments 27, 29 is consequently limited, in particular by taking into account the value of the assumed repeating angular pitch P16 with respect to the stay 16 and thus the groove 15, in order to take advantage where possible of the particular flexibility and / or relatively loose state of the stay 16 after hardening operation, so that the lug keys 26, 28 can be simultaneously disengaged from all the stays 16 that they enclose without damaging the stays.

[0099] As an example, regarding the arrangement of grooves 15 along the radial plane, there are preferably 5 to 23 grooves 15 per lug key 26, 28, and preferably 5 to 9 grooves per lug key 24, and more preferably 7 grooves per lug key 26, 28 as shown in Figures 7B, 9B, and 10.

[0100] The corresponding lug-shaped segments 27 and 29 may preferably have 3 to 21 grooves 15, more preferably 3 to 7 grooves 15, and may have, for example, 5 grooves 15 as shown in Figures 8B and 8B.

[0101] In the example in Figure 10, lugs 22 and 23 are formed using 20 lug keys 26, each occupying an angular sector A26 with a value of 9 degrees and each having 7 grooves contained in the radial plane, and 20 conjugate lug arch segments 27, each occupying an angular sector A27 with a value of 9 degrees and each having 5 grooves contained in the radial plane. The sides 40 and 41 of the lug keys 26 are parallel to each other and parallel to the sagittal meridional plane P_MER_26 of each lug key 26, while the sides 42 and 43 of the lug arch segments 27 form an angle of 18 degrees between them and each form an angle of 9 degrees with respect to the sagittal meridional plane P_MER_27 of the lug arch segments 27.

[0102] When the grooves 15 intersect at an inclination, as in Figures 11B, 12B, 13B, and 14B, there can be 4 to 8 entrances to the grooves 15 corresponding to the number of lateral fixing points 18 per lug sector 26, 27, 28, 29 for each lug key 26, 28 and each lug arch segment 27, 29. More preferably, as shown in Figures 11B, 12B, 13B, and 14B, there can be 6 entrances to the grooves 15, in which case each sector has 3 entrances to the grooves 15 that are inclined to the left (i.e., counterclockwise) in projection on a plane perpendicular to the central axis Z10, and 3 entrances to the grooves that are inclined to the right (i.e., clockwise) in projection on a plane perpendicular to the central axis Z10.

[0103] Preferably, the lug keys 26 and 28 are identical and interchangeable within at least one lug 22, or even interchangeable between one lug 22 and the other lug 23.

[0104] Similarly, the lug-shaped segments 27 and 29 are preferably identical and interchangeable within at least one lug 22, or even interchangeable between one lug 22 and the other lug 23.

[0105] Preferably, the lug-shaped segments 27, 29, more preferably only the lug-shaped segments 27, 29, are fastened to the central ring 21 by screws, more specifically to the tapered faces 32, 33 (the lug keys 26, 28 are not fastened), and these screws are inserted centrifugally radially from the empty internal space of the central ring 21 so as to engage with the radial inner surfaces of the lug-shaped segments 27, 29, for which through holes 34 in the central ring 21 can be seen in Figures 3A, 3B, 4A, 4C, 5A, 5C, 6A, and 6C.

[0106] The lug keys 26 and 28 interact with the lug arch segments 27 and 29 and can therefore be positioned and held by pins that engage with pinholes 35 provided in the keys 26 and 28, as seen in Figures 7A, 9A, and 11A, which engage with corresponding recesses 36 provided in the lug arch segments 27 and 29, as shown in Figures 8A and 21B.

[0107] As a variation, as seen in Figures 13A, 13D, 15A, and 15C, the lug keys 26 and 28 may be provided with projecting tenons 37 suitable for interacting with the mortises 38 provided in the lug arch segments 27 and 29, as seen in Figure 14A.

[0108] Preferably, the lug sectors 26, 27, 28, and 29, including the lug keys 26, 28 and the lug arch segments 27, 29, are made from a metal alloy, more preferably from an aluminum alloy, so that they have satisfactory rigidity and satisfactory thermal conductivity and relatively low thermal inertia. When implementing the cross-groove 15, it may be preferable to make the lug sectors 26, 27, 28, and 29 from a metal material more robust than aluminum, such as maraging steel, in order to improve the strength of the prism 20.

[0109] Preferably, the lug sectors 26, 27, 28, and 29 are manufactured by additive manufacturing, which simplifies the production of relatively complex geometric shapes.

[0110] In one possible embodiment, the sides 40, 41 of at least one lug key 26, 28 define an angular sector A26 that the lug key 26, 28 azimuthally occupies around the central axis Z10, so that the lug key 26, 28 forms a dividing line PJ that interacts with the adjacent lug arc segments 27, 29 within the annular subassemblies 22, 23, i.e., within the corresponding lugs 22, 23 in the assembled state, but this side 40, 41 is the "sagittal meridian" Parallel to a virtual plane called P_MER_26, which, as seen in Figures 7B, 9B, 10, and 11B, includes the central axis Z10 and corresponds to a radial plane intersecting the center of the angular sector A26 occupied by the lug keys 26, 28, so that these sides 40, 41 allow the lug keys 26, 28 to be pulled out from the adjacent lug arch segments 27, 29 by sliding and / or tilting along the dividing line PJ, as shown in Figures 20A-20D, 21A, and 21B.

[0111] The sagittal meridional plane P_MER_26, in projection onto a plane perpendicular to the central axis Z10 and the arcs representing the radial outermost boundaries of the lag keys 26, 28, subdivides the arcs corresponding to the radial outermost boundaries of the portions of the receiving surface 10_out belonging to the lag keys 26, 28 into two equal semicircles contained in adjacent angular half-sectors with the same azimuth range equal to A26 / 2.

[0112] The sides 42 and 43 of the lag arch segments 27 and 29 are preferably formed by planes oriented in a direction conjugate to the direction of the sides 40 and 41 of the lag keys 26 and 28 on both sides of the sagittal meridional plane P_MER_27 of the arch segments 27 and 29.

[0113] Therefore, within the lugs 22 and 23, the lug keys 26 and 28 and the lug arch segments 27 and 29 are in close contact with each other, thereby giving the lug keys 26 and 28 three potential degrees of freedom relative to the lug arch segments 27 and 29: two translational degrees of freedom in the two secant directions that define the dividing line PJ, and one rotational degree of freedom around an axis perpendicular to the dividing line PJ and thus corresponding to the circumferential direction vector, which allows the key to be tilted as shown in Figures 20D, 20E, 21B, and 21C.

[0114] It should be noted that such arrangement of lug keys 26, 28 with flat, parallel sides 40, 41 can be implemented in grooves 15 (Figures 7A, 7B, 7C, 9A, 9B, 9C, 10, and 23) where the sagittal meridional plane P_MER_26 of the lug keys 26, 28 is preferably aligned along a radial plane that coincides with the sagittal meridional plane of the groove 15, or in diagonally intersecting grooves 15 (Figures 11A, 11B, 11C) if the groove 15 has an appropriate shape.

[0115] In one possible embodiment, the grooves 15 of each single lug sector 26, 27, 28, 29 are each separated by two transverse walls generated in the overall axial direction DG_A, vectorially collinear, i.e., parallel to the central axis Z10, as in the variations of Figures 7A, 8A, 9A, and 10, which have grooves 15 contained in the radial plane, and the variations of Figures 11A, 12A, which have cross-intersecting inclined grooves 15.

[0116] Instead, in one possible embodiment similar to the previous embodiment, a general direction substantially parallel to the central axis Z10 but not strictly so, is used, in which the grooves 15 within single lug sectors 26, 27, 28, 29 are each separated by two lateral walls that form tapered surfaces extending from the bottom 19 of the groove 15 to the receiving surface 10_out, thereby expanding free space throughout the inside of the groove 15 that confines a virtual volume called the “required clearance volume,” which is generated by virtually moving the stay 16 along a virtual exit trajectory, here from a position of the stay 16 near the bottom 19 of the groove 15 to the receiving surface 10_out, and is contained in the overall axial direction DG_A that is vectorially collinear, i.e., parallel to, the central axis Z10.

[0117] In either case, that is, whether the lateral walls of the groove 15 are generated strictly in the overall axial direction DG_A or substantially in the overall axial direction (tapered) DG_A, such arrangement of lateral walls means that the groove 15 allows the lug sectors 26, 27, 28, and 29 to be axially pulled out by an axial pull-out movement M_A parallel to the central axis Z10 and directed toward the equatorial plane P_EQ of the core 10, as shown in Figures 20B, 20C, and 21A, without the lateral walls of the groove 15 interfering with the stay 16 during the axial pull-out movement M_A.

[0118] When a stay 16 contained in a single lug sector 26, 27, 28, 29 is removed in a straight line, that is, when the stay 16 is removed from the groove 15 by linear translation by performing the withdrawal movement relative to the lug sectors 26, 27, 28, 29 in the overall axial direction DG_A, the stay 16 moves as specified through a volume corresponding to the required clearance volume, the lateral boundary of that volume is defined by an edge consisting of a straight line parallel to the overall axial direction DG_A, and no material mass defining the groove 15 shall enter the inside of its enclosing surface and obstruct the withdrawal. Therefore, if the lateral wall of the groove 15 is not parallel to the overall axial direction DG_A, or if the lateral wall does not flare out relative to the overall direction DG_A so as to form a tapered surface that widens toward the receiving surface 10_out, the wall will interfere with the clearance volume, and thus the lateral wall of the groove 15 will form an obstacle that collides with the stay 16 during withdrawal, and thus the inclination effect will generate a lateral thrust that deflects the stay 16 away from the desired location, potentially damaging or even breaking the stay 16.

[0119] Of course, regardless of the arrangement selected with respect to the side walls of the groove, the width W15 of the groove corresponding to the distance separating the two side walls that define the groove 15 has the above-mentioned ratio and / or dimensions, and therefore can be particularly 0.1 mm to 3 mm.

[0120] In one possible embodiment, if the core 10 has lugs 22, 23 that are angularly subdivided into sectors 26, 27, 28, 29, and the passage 15 for the stay is formed by a cross-intersecting groove 15, then the cross-intersecting groove 15 in a single lug sector 26, 27, 28, 29 can be separated by two transverse walls generated in an oblique overall direction DG_O, respectively, as in the cases of Figures 13A-13D, 14A-14D, 15A-15C, 17, 18A, 19, and 22A-22C, and this oblique overall direction DG_O is "S The sagittal meridian planes P_MER_26 and P_MER_27 are contained within radial planes that intersect the centers of lag sectors 26, 27, 28, and 29. In the sagittal meridian planes P_MER_26 and P_MER_27, the directions from lags 22 and 23 toward the opposite lags 23 and 22 converge toward the central axis Z10, forming an angle with the central axis Z10 called the "co-latitude angle" A44, which is not zero, is not strictly less than 90 degrees, and is preferably between 30 and 50 degrees, for example between 40 and 47 degrees, or equal to, for example, 45 degrees.

[0121] Therefore, advantageously, the overall oblique direction DG_O "intrudes" toward the equatorial plane P_EQ and toward the opposite lugs 23 and 22, and thus, the oblique pull-out movement M_O directed toward the inside of the core 10 and having both axial and radial components simultaneously, enables the pull-out of lug sectors 26, 27, 28, and 29.

[0122] Thus, the absolute value of the colatitude angle A44 is selected such that, considering the point at which the bead 4 forms the most pronounced undercut in the sagittal meridional planes P_MER_26 and P_MER_27, the angle made by the tangent T4 to the inner surface 8_in of the tire wall 8 at the bead 4 is less than or equal to the angle of the tangent T4 to the inner surface 8_in of the tire wall 8 at the bead 4. Note that the orientation of the tangent T4 with respect to the central axis Z10 determines the "release threshold," that is, it determines the maximum colatitude angle that the oblique pull-out movement M_O can take to release the lug sectors 26 and 27 by sliding along the inner surface of the bead 4 without being stopped by the bead 4, and therefore without pushing back (opening) the bead 4 and the corresponding side wall 6 of the tire 2 during the release operation, as shown in Figures 22A, 22B, and 22C. Of course, the considerations that apply to the left lug 22 can also be applied to the right lug 23.

[0123] Also advantageous, as can be clearly seen by comparing Figures 13A and 13C with Figures 11A and 11C respectively, by generating the lateral walls of the cross-shaped groove 15 in an oblique overall direction DG_O that is closer to the normal of the bottom 19 of the groove 15 than in the axial direction, it is possible to reduce the height of the rectangular prism 20 (or column) that forms the wall of the cross-shaped groove 15 and extends between the bottom 19 of the groove and the opening of the groove 15 on the receiving surface 10_out, compared to the overall direction DG_A in the axial direction. Therefore, this rectangular prism 20 and thus the lug sectors 26, 27, 28, and 29 are more rigid and stronger.

[0124] When selecting an embodiment in which the lateral walls of the groove 15 are generated in the oblique overall direction DG_O, the sides 40, 41 defining the lag keys 26, 28 and thus the dividing line PJ can preferably be generated in the oblique overall direction DG_O based on one of the following base profiles 45: i) In the first option, a base profile 45 corresponding to the intersection line 46 of the receiving surface 10_out and radial planes P1, P2 whose azimuth angle is angularly offset by a certain value with respect to the sagittal meridian P_MER26 of the lag keys 26, 28, passing through opposing vertices of the grid units (i.e., the bottom surfaces of the prisms 20 described above), thus hereby shown in Figures 13B, 13D, 14B, 14D, 15A, 16B, The base profile 45, ii) or a second option, the base profile 45, on the receiving surface 10_out, corresponds to a zigzag broken line 47 formed by alternating edges of grid units (the bases of the aforementioned prisms 20), and thus here on the receiving surface, by alternating edges of quadrilaterals, as shown in Figures 18A, 18B, and 19, which are defined on the receiving surface by the cross-intersecting grooves 15 and extend from the crown zone 11 to the lateral zones 12 and 13.

[0125] In either case, such a selection of the base profile 45 is advantageous in that, at the dividing line PJ, it is possible to avoid or significantly reduce the “error” which is the offset between the grooves 15 belonging to the lug keys 26, 28 located on one side of the dividing line PJ and the grooves 15 belonging to the lug arch segments 27, 29 located adjacent to those lug keys on the other side of the dividing line PJ. These errors result from the fact that the lateral walls of the grooves 15 are generated in the same oblique overall direction DG_O and therefore parallel to each other, so that the grooves 15 in a single first lug sector 26, 27, 28, 29 do not strictly follow a radially circular distribution, and therefore their ends appearing on the dividing line PJ on the receiving surface 10_out do not necessarily coincide with the ends of the grooves 15 in adjacent lug sectors that need to connect the grooves 15 in the first lug sector.

[0126] However, the wise selection of the base profile 45 ensures that the groove in one lug sector is substantially continuous from the corresponding groove in the adjacent lug sector, thereby ensuring proper connection and continuity of the groove 15 on the receiving surface 10_out where the groove 15 crosses the dividing line PJ, thereby ensuring that the stay 16 can be easily inserted into the groove 15 substantially radially from the outside of the core 10 through the receiving surface 10_out.

[0127] The solution, which involves selecting a base profile 45 that follows a broken line 47 that alternately forms concave and convex angles along a wall defined by a series of rectangular prisms 20 (shown as dashed lines in Figures 18A, 18B, and 19), is generally satisfactory and allows for a robust and precise fit of the lug keys 26, 28 into the lug arch segments 27, 29. However, it has the drawback of forming stripes that tend to locally widen certain grooves 15 on the receiving surface 10_out along the dividing line PJ, as seen in Figure 19.

[0128] Therefore, the first solution is considered preferable, in which the base profile 45 is a curve 46 drawn on the receiving surface 10_out by the intersection lines of the radial planes P1, P2 and the receiving surface 10_out, and passing through the vertices of the quadrilaterals along the diagonals common to the consecutive quadrilaterals, as shown in Figures 13A, 13B, 13, 14D, 15A, and 17.

[0129] Such a solution advantageously allows the nodes of the quadrilateral mesh defined by the cross-intersecting grooves (i.e., nodes formed by the intersection of two grooves), more generally the nodes of the prism mesh belonging to the lug key 26, to coincide with the nodes of the quadrilateral mesh belonging to the corresponding lug arch segment 27 located on the other side of the dividing line PJ. This ensures the continuity of the groove 15 at the connection between consecutive lug sectors without significantly affecting the width W15 of the groove 15.

[0130] The geometric principle for generating the base profile 45 corresponding to the intersection line 46 between the receiving surface 10_out and the radial planes P1 and P2 is shown in Figures 16A to 16D.

[0131] As shown in Figure 16A, it is first necessary to define the sagittal meridional plane P_MER_26 of the lag sector, in this example the lag key 26. For this purpose, two hypothetical radial planes P1 and P2 are defined on either side of the sagittal meridional plane P_MER_26, each at the same angular distance from the sagittal meridional plane P_MER_26, which is equal to half of the desired angular range A26 of the lag sector 26.

[0132] Advantageously, since the values ​​of the angular range A26 are all multiples of the repeating pitch P16 of the groove 15, it is possible to arrange each radial plane P1, P2 in a line with the nodes formed by the vertices of the quadrilateral traced by the cross-intersecting groove 15.

[0133] Next, as shown in Figure 16B, we consider the base profile 45 corresponding to the curve 46 that forms the intersection line between the donut-shaped receiving surface 10_out and the radial planes P1 and P2.

[0134] Next, starting from these curves 46, the curves 46 are translated along a linear oblique overall direction DG_O that is contained within the sagittal meridional plane P_MER_26 and directed toward the central axis Z10, which is selected to penetrate towards the oblique overall direction DG_O. This generates the sides 40, 41 of the lag sector 26 (Figure 16C).

[0135] In practice, this corresponds to cutting the sides 40, 41 of the lag sector 26 based on the projection of the base profiles 45, 46 in a plane P3 perpendicular to the selected diagonal overall direction DG_O, as shown in Figure 16D.

[0136] In addition, regardless of the assumed modified embodiments with respect to the lug sectors 26, 27, 28, and 29, particularly when the lug sectors have cross-intersecting inclined grooves 15 generated in the diagonal overall direction DG_O, the core 10 may preferably have a recess 50 on the back of the side wall, below the receiving surface 10_out, and separate from the passages 15 that penetrate between the passages 15, as shown in Figures 15B and 15C, and separated from the passages 15 by the side wall.

[0137] The recesses 50 formed in the lug sectors 26, 27, 28, and 29 open toward the inside of the core 10, here more specifically on the support surfaces of the lug sectors facing the tapered faces 32 and 33 of the ring.

[0138] Since it is preferable that this recess extends below the receiving surface 10_out to a depth lower than the hollow depth of the passage 15 facing the recess, that is, to a depth lower than the depth of the bottom 19 of the groove 15, the core 10 has a thinner surface in the portion along the recess 50 than in the portion along the side wall of the passage 15.

[0139] Such recesses 50 make it possible to provide the lugs 22 and 23 with a lightweight structure, and in particular with low thermal inertia, and as a result, heat transfer from the central ring 21 which confines a heating element, preferably such as an electro-heating resistor, is optimized.

[0140] Therefore, by favorable features that can form an invention in themselves, particularly in combination with the sectoral angular division of the lugs 22, 23 and / or the central ring 21, it is possible to create a core in which only the central ring 21, and more specifically only sectors 24, 25 of the central ring 21, confines a heating element such as an electro-heating resistor, while the lugs 22, 23 do not have a heating element, and yet it is still possible to ensure a rapid and uniform temperature rise of the receiving surface 10_out during the curing operation of the tire 2.

[0141] In addition, due to preferred features that can form an invention on their own and are applicable to any of the above-described modifications, the tool 1 may include a barrier device 60 that interacts with the core 10 to prevent components forming the crown 3, side walls 6, 7 or beads 4, 5 of the tire 2 from entering the passage 15 of the core 10 into which the stay 16 engages.

[0142] More specifically, the barrier device 60 prevents materials present within the components of the tire 2, particularly rubber-based compositions, from creeping into the groove 15, so as to prevent the formation of a rubber rib that would bond the stay 16 to the wall of the groove 15 and thus create a risk of pulling out the stay 16 when pulling out the corresponding lug sectors 26, 27, 28, and 29.

[0143] The barrier device 60 may include masking elements 61, 62 suitable for forming a screen on the receiving surface 10_out between the components of the tire wall 8 and the opening of the passage 15 for the stay, in this case the opening of the groove 15. Of course, the masking element 61 is selected to withstand the high temperature values ​​(typically above 100°C) and pressure values ​​(typically above 60 bar) to which the core 10 and tire 2 are exposed during the curing operation.

[0144] For the masking element, an adhesive such as steel metal tape or a flexible tape held with adhesive tape can be used, and this flexible tape is applied to the receiving surface 10_out after the stay 16 is positioned in the groove 15 to cover the groove 15.

[0145] In a preferred possible embodiment, the masking element comprises a reusable shell 61 made of, for example, a polymer or preferably a metal.

[0146] The shell 61 is preferably a curved C-shape, and as seen in Figures 6A, 6B, 6C, 20A, and 21A, each of the shells 61 follows the curve of the core 10, in this case the curves of the lugs 22, 23, and preferably integrally covers the opening of the groove 15 continuously from the lateral zones 12, 13 to the crown zone 11.

[0147] In a preferred embodiment, as shown in Figures 6C, 9A, 9B, and 9C, the lug sectors 26, 27, 28, and 29 may be provided with recesses 62 into which the corresponding shell 61 can be mounted and which are advantageously positioned and held by one or more shoulders. The depth of the recesses 62 is preferably such that the radial outer surface of the shell 61 is flush with the adjacent receiving surface 10_out.

[0148] Preferably, to facilitate dismantling, a separate shell 61 is provided for each lug sector 26, 27, 28, 29, and as can be clearly seen in Figure 6A, each shell 61 covers the same angular sectors A26, A27 as the lug keys 26, 28 or lug arch segments 27, 29 that the shell 61 will cover.

[0149] Preferably, all of the shells 61 are identical to each other and can therefore be interchanged between each other, preferably between two lugs 22, 23 within at least one lug 22.

[0150] Preferably, in addition to the shell 61, the masking element may also include a masking strip 63, preferably formed of a metal tape, which can help conceal the opening of the groove in the crown zone 11 of the receiving surface 10, preferably by partially overlapping with the shell 61, as shown particularly in Figures 6A, 6B, and 6C. This overlap may extend over several millimeters in the axial direction, for example, 3 mm to 15 mm.

[0151] Dividing the masking screen into a shell 61 and a masking strip 63 facilitates demolding and, more specifically, the removal of the shell 61 and strip 63 from inside the tire between the stays 16. Additionally, the overlap of the shell 61 and strip 63 advantageously prevents leakage clearance from occurring between these two masking elements.

[0152] Preferably, as shown in Figures 6A, 6B, and 6C, the tool 1 comprises two sets of shells 61, one set on each side of the equatorial plane P_EQ, and two strips 63, each forming a complete single turn around the central axis Z10 and located on one side of the equatorial plane P_EQ.

[0153] Each of the strips 63 remains axially in front of the equatorial plane P_EQ such that a portion of the crown zone 11 formed by the central ring 21, where the crown fixing points 17 are formed, remains uncovered.

[0154] As a variation, in addition to or preferably instead of the masking elements 61, 63, the barrier device 60 may include filling elements 65 designed to fill, and thus substantially close, any gaps that remain empty within the passage 15 after the stay 16 has been placed in the passage 15.

[0155] More specifically, the filling element 65 can occupy the free space between the side wall of the groove 15, the stay 16 contained in the groove in question, and the opening of the groove on the receiving surface 10_out.

[0156] Any suitable material can be used as the filler element 65 that can enter the passage 15 and has a density sufficient to prevent or substantially delay the intrusion of tire components, particularly materials forming an unvulcanized rubber-based mixture, into the groove 15.

[0157] In one exemplary embodiment shown in Figure 23, the filling element is preferably made of metal and can be formed by a rigid shim 65 having a shape substantially conjugate to the cavity of the groove 15, which is inserted into the groove 15 after the stay 16 has been first engaged with the groove.

[0158] Of course, the present invention also relates to a method for manufacturing a tire 2 with a stay on a core 10.

[0159] In fact, such a method preferably corresponds to using tool 1 as described above.

[0160] Accordingly, the present invention also relates to a method for manufacturing a donut-shaped tire 2 comprising a crown 3 suitable for forming a tread, a first annular bead 4 and a second annular bead 5 designed to allow the tire to be mounted on a mounting support such as a rim, and a first side wall 6 and a second side wall 7 connecting the crown 3 to the first bead 4 and the second bead 5, respectively, wherein the crown 3, the first and second side walls 6 and 7, and the first and second beads 4 and 5 together form a wall 8 having a concave inner surface 8 that defines the cavity 9 of the tire 2, and the tire 2 comprises reinforcing elements 16 called “stays” 16, each extending into the cavity 9 of the tire and connecting a crown fixing point 17 located on the crown 3 of the tire to a lateral fixing point 18 located on one of the side walls 6 and 7 or the beads 4 and 5 of the tire.

[0161] This method comprises a preparation step (S0) in which tool 1 according to the present invention is prepared.

[0162] More specifically, during this preparation stage (S0), as shown in Figures 3A and 3B, the ring key 24 and the ring arched segment 25 are assembled to form the central ring 21, and then, as shown particularly in Figures 4A-4C and 5A-5C, a series of lug keys 26, 28 and lug arched segments 27, 29 are fastened to each of the tapered faces 32, 33 of the central ring 21 to form the lugs 22, 23.

[0163] Next, the method includes a step (S2) of positioning the stay 16, during which at least one reinforcing thread 70 suitable for forming the stay 16 is passed through each passage 15 of the core 10.

[0164] Preferably, a single continuous single strand or multiple strands 70 are used to form a plurality of stays 16, preferably forming more than 25%, more than 50%, or even all of the stays 16 of the tire 2.

[0165] For this purpose, the continuous reinforcing threads 70 are arranged to meander through a continuous passage 15, and as seen here in Figure 24, the reinforcing threads 70 are inserted into the groove 15 below the receiving surface 10_out and brought back above the receiving surfaces 10_out of the crown zone 11 and the lateral zones 12, 13 to emerge at the desired fixing points 17, 18, and so on, as seen in Figure 25, the continuous reinforcing threads 70 are arranged to reciprocate integrally from one lateral zone 12 to the other lateral zone 13 of the core 10 while passing through the crown zone 11, forming an uneven surface, here forming an uneven surface with an amplitude substantially symmetrical with respect to the equatorial plane P_EQ.

[0166] Next, the method includes a filling step (S4) during which the components forming the crown 3, side walls 6, 7, and beads 4, 5 are placed on the receiving surface 10_out to form the wall 8 of the tire 2.

[0167] These components preferably comprise rubber-based strips or pies and are optionally reinforced with longitudinal reinforcing fibers of fabric, polymer, or metal. Other reinforcing components, such as composite fiberglass and resin strips, may also be provided.

[0168] Preferably, all or part of these components can be wrapped around and laid on the rotating core 10.

[0169] Next, this method includes a curing step (S5).

[0170] During this stage, the core 10 and the tire 2 held within the core 10 are placed in a curing mold to vulcanize the rubber-based components of the tire 2. For this purpose, it is preferable to bring the temperature of the mold, and more specifically the temperature of the tire, to a value of 120°C to 200°C.

[0171] Next, the method includes a demolding step (S6), during which the core 10 is disengaged from the tire 2 while the stay 16 remains in place within the cavity 9 of the tire 2, particularly as shown in the withdrawal sequences in Figures 20A-20F, 21A-21C, and 22A-22C.

[0172] If parts of the core 10, such as lugs 22 and 23, are single-use, they can be destroyed in an appropriate manner (melting, dissolution, crushing, impact, sublimation, etc.) to release the cavity 9 and stay 16.

[0173] Preferably, if the core 10 is reusable and thus consists of a modular assembly of disassemblable components, these components can be gradually disassembled and pulled out to release the tire 2.

[0174] Preferably, after the preparation step (S0) and before the step of positioning the stay 16 (S2), the method comprises a pre-filling step (S1), during which, as shown in Figure 24, fastening structures 71, 72 are provided to receive the ends of the stay 16 emerging from the passage 15 of the core 10 and to bond them to the components forming the side walls 6, 7 or the beads 4, 5 or the components forming the crown 3, respectively, and the fastening structures 71, 72 are provided to fix the ends of the stay 16 to fastening points 18, 17 provided by sandwiching the fastening structures 71, 72 between these components, and are laid in the lateral zones 12, 13 and the crown zone 11 of the receiving surface 10_out of the core 10 facing the fastening points 18, 17 provided for attaching the stay 16 to the wall 8.

[0175] Preferably, the fastening structures 71 and 72 are formed from an unvulcanized rubber-based material and optionally reinforced with reinforcing threads or reinforcing fibers. The fastening structures 71 and 72 can take the form of reinforcing strips or windings wrapped around the core 10, for example.

[0176] With the fastening structures 71 and 72 positioned and waiting on the receiving surfaces 10_out on the outer side of the grooved portion at the desired fastening points 18 and 17, the stay 16 is positioned in the passage so that the portion of the stay 16 exiting the passage 15 is positioned above the fastening structures 71 and 72. As the components of the tire wall 8 are laid, these components adhere to the fastening structures already in place on the core 10, and as a result, the fastening structures 71 and 72 are incorporated into the wall 8 of the tire 2, thereby trapping the end of the stay 16 within the wall 8 at the provided fastening points 18 and 17.

[0177] Preferably, it is a loop that forms the extremum of the serpentine convexity of the continuous reinforcing thread 70, and thus corresponds to the transition zone between two consecutive stays belonging to a single hemisphere, forming a portion of stay 16 that is captured by a lateral fixing structure 71 located in lateral zones 12, 13 to form the lateral fixing point 18 of the stay, while the intermediate portion of the continuous reinforcing thread 70 connecting two consecutive stays 16 belonging to two different hemispheres will emerge from the groove 15 of the first stay, cross the crown zone 11 of the receiving surface 10_out, pass through the equatorial plane P_EQ, then return to the groove 15 of the second stay 16, and be captured by the crown fixing structure 72.

[0178] Preferably, after the step of positioning the stay 16 (S2), the method comprises a protection step (S3) during which a barrier device 60 is implemented, which interacts with the core 10 during the filling step (S4) and the curing step (S5) to prevent the components forming the crown 3, side walls 6, 7 or the beads 4, 5 of the tire 2 from entering the passage 15 of the core 10, in which case the groove 15 into which the stay 16 engages.

[0179] For example, after the stay placement step (S2) and before the filling step (S4), a masking element such as the shell 61 and / or masking strip 63 described above can be applied to the receiving surface 10_out as shown in Figures 6A and 6B to cover the passage 15 and thus form a screen between the passage 15 and the components of the tire wall 8. Alternatively, a filling element 65 such as a shim 65 (Figure 23) can be used to temporarily fill the volume of each passage 15 that remains open between the stay 16 engaged with the passage 15 and the opening(s) of the passage 15 that appear in the receiving surface 10_out.

[0180] Preferably, the core 10 comprises a central ring 21 and left lugs 22 and right lugs 23 that enclose a passage 15 for the stay 16 in the form of a groove 15 opening on the receiving surface 10_out, so that the central ring 21 and each of the lugs 22, 23 are angularly divided into sectors that form keys 24, 26, 28 alternating with arched segments 25, 27, 29, as described above, and the demolding step (S6) is first a partial step of removing the central ring 21, during which the keys 24 of the central ring and then the arched segments 25 of the central ring are radially removed to release the lugs 22, 23, leaving the sectors 26, 27, 28, 29 of the lugs 22, 23 accessible from the inside of the tire 2 as shown in Figures 20A and 22A, and then a second partial step of pulling out the first lug 22 The present invention relates to a second partial stage in which, during that stage, the key 26 of one of the left and right lugs 22 is pulled out from the cavity 9 of the tire 2, and then the arched segment 27 of the lug 22 is pulled out from the cavity 9 of the tire, thereby releasing the corresponding portion of the cavity 9 and the stay 16 located in the corresponding portion of the cavity 9, in this case the stay 16 occupying the first hemisphere of the tire 2; and a third partial stage in which the other lug 23 is pulled out, during that stage, the key 28 of the other lug 22 is pulled out from the cavity 9 of the tire 2, and then the arched segment 29 of the other lug 23 is pulled out from the cavity 9 of the tire, thereby releasing the corresponding portion of the cavity 9 and the stay 16 located in the corresponding portion of the cavity 9, in this case the stay 16 occupying the second hemisphere of the tire 2.

[0181] Note that while the order in which the sectors of lugs 22 and 23 are pulled out can be slightly adjusted as needed, the only requirement is that the two lug keys 26 and 28 on either side of the lug arc segments 27 and 29 within a given lug are pulled out first, followed by the lug arc segments 27 and 29 being pulled out in sequence. Therefore, for example, one could choose to first pull out the key 26 of the first lug 22, then the arc-shaped segment 27 of the first lug 22, then begin pulling out the key 28 of the second lug 23 and continue pulling out the arc-shaped segment 29 of the second lug, or to first pull out the key 26 of the first lug 22, then the key 28 of the second lug 23, then the arc-shaped segment 27 of the first lug 22, and finally the arc-shaped segment 29 of the second lug 23, or to gradually pull out the key 26 of the first lug, then the lug key located on the opposite side of the corresponding lug arc-shaped segment 27, then the lug arc-shaped segment 27 thus released, then the directly adjacent lug key 26, and then the second lug arc-shaped segment 27 thus released, in a stepwise azimuthal manner around the central axis Z10 within a single lug.

[0182] Sectors 26, 27, 28, and 29 of each lug 22 and 23 are pulled out by the following pull-out movements, which depend on the arrangement of the groove's side walls: i) When the lateral walls of the groove 15 are generated in the overall axial direction DG_A parallel to the central axis Z10, as shown in Figures 20B, 20C, and 21A, and the axial translational pull-out movement M_A, in particular the distance separating the lugs 22 and 23 in the axial direction is smaller than the total axial length of the pulled-out sectors 26, 27, 28, and 29 due to the dimensions of the tire 2 being manufactured, preferably this axial translational pull-out movement M_A is followed by Figures 20D, 20E, 21B, and 21 As shown in C, the sectors 26, 27, 28, and 29 can perform an inclined movement M_B around an axis perpendicular to the sagittal meridional planes P_MER_26, P_MER_27, i.e., this inclination M_B is facilitated by the fact that the radially inner lower surface of lug 23 opposite to the lug 22 to be disassembled forms a conjugate inclination with respect to the inclination of the corresponding tapered surface 32 of the central ring 21, and thus provides the corresponding clearance when the central ring 21 is removed. ii) Alternatively, in the case of an oblique centripetal translational movement M_O, when the lateral wall of the groove 15 is generated in the oblique overall direction DG_O intersecting the central axis Z10 at a non-zero acute colatitude angle A44, it simultaneously possesses both an axial component and a radial component, as shown in Figures 22A, 22B, and 22C. This oblique translational movement M_O is advantageously contained within the oblique overall direction DG_O.

[0183] In the first case i) above, it should be noted that the axial translational withdrawal movement M_A is necessary in particular to allow the lobes of lugs 22 and 23 to be fully disengaged from the hollow of the cavity 9, especially from the inner lips of beads 4 and 5, and then to allow the tilting movement M_B to be performed without forcibly separating beads 4 and 5 from the crown 3, and therefore without forcibly separating the stay 16.

[0184] It should also be noted that the inventors observed that, undoubtedly due to the residual temperature (possibly 50°C to 70°C) when the core 10, and especially the tire 2, is pulled out of the core 10 after hardening, the stay 16 is still relatively loose, i.e., not yet fully taut, making it easier to pull out the stay 16 without damaging it.

[0185] Regardless of the initial trajectories taken with respect to the withdrawal movements M_A and M_O, the withdrawal sequence for withdrawing the lug sectors 26, 27, 28, and 29 with them disengaged from the stay 16 can be freely completed from inside the tire 2 by moving the sectors 26, 27, 28, and 29 toward the central axis Z10, followed by a radial movement that radially intersects the threshold formed by the beads 4 and 5, and then an axial movement that completely withdraws the sectors 26, 27, 28, and 29 from the axially defined envelope surface by the tire 2, as shown in Figure 20F.

[0186] With sectors 26 and 27 of one lug 22 withdrawn, or after each lug 22 and 23 has been disengaged from the cavity 9 of the tire 2, the corresponding shells 61 can be individually and sequentially withdrawn by rotating and tilting (one arm of the shell behind the other) to slide the shell 61 by its edge between the two stays 16. Similarly, the masking strips 63 can be withdrawn by spiral sliding through the space between two consecutive stays 16.

[0187] Of course, the present invention is by no means limited to the modified embodiments described above, and those skilled in the art will find that the above-described features can be separated, freely combined, or replaced with equivalents. [Explanation of symbols]

[0188] 2. Donut-shaped tires 3 Crown 4. First annular bead 6. First side wall 10 donut-shaped cores 16 Stays / Reinforcement Elements

Claims

1. A tool (1) suitable for manufacturing donut-shaped tires (2), The donut-shaped tire (2) comprises a crown (3) suitable for forming a tread, a first annular bead (4) and a second annular bead (5) designed to allow the tire (2) to be attached to a mounting support such as a rim, and a first side wall (6) and a second side wall (7) connecting the crown (3) to the first bead (4) and the second bead (5), respectively. The crown (3), the first and second side walls (6, 7), and the first and second beads (4, 5) together form a wall (8) having a concave inner surface (8_in) that defines the cavity (9) of the tire (2). The tool (1) comprises a donut-shaped core (10) having a convex outer surface called a "receiving surface" (10_out) around its central axis (Z10), The donut-shaped core has a shape conjugate to the inner surface (8_in) of the tire wall (8) and comprises a radially outer crown zone (11) suitable for receiving components that form the crown (3) of the tire (2), a first lateral zone (12) on both axial sides of the crown zone (11) that is folded back toward the central axis (Z10) and is suitable for receiving components that form the first side wall (6) and the first bead (4), and a second lateral zone (13) that is folded back toward the central axis (Z10) and is suitable for receiving components that form the second side wall (7) and the second bead (5), thereby the core (10) embodies a volume called a "reserved volume" that is externally separated by the receiving surface (10_out) and corresponds to the cavity (9) of the tire. The core (10) has a plurality of passages (15) that extend inside the secured volume below the receiving surface (10_out) and open above the receiving surface (10_out), so that each of the passages (15) can receive inside the passages (15) reinforcing elements called “stays” (16) that are designed to be permanently incorporated into the structure of the tire (2), each extending inside the cavity (9) of the tire and connecting crown fastening points (17) located on the crown (3) of the tire to lateral fastening points (18) located on either the sidewalls (6, 7) or the bead (4, 5) of the tire, such that the crown zone (11) of the receiving surface connects to one of the first and second lateral zones (12, 13). A tool characterized by (1).

2. The tool according to claim 1, wherein the passages (15) for the stays (16) are formed by grooves (15) cut out from the receiving surface (10_out) within the thickness of the secured volume, and so they have openings that are continuous along the profile of the receiving surface (10_out) from the crown zone (11) to the lateral zones (12, 13) in question.

3. The aforementioned core (10) is i) A first annular subassembly (21) called a "center ring" (21) that forms the central portion of the crown zone (11) of the receiving surface (10_out) suitable for receiving one or more components that form the crown (3) of the tire (2), ii) A second annular subassembly (22) called a “left lug” (22) that is axially adjacent to the central ring (21) and comprises a portion of the crown zone (11) that extends axially, the first lateral zone (12) of the receiving surface (10_out) and the central portion of the crown zone (11) on the corresponding side of the central ring (21), and encloses the groove (15) that forms the passage for the stay (16) that connects the first side wall (6) of the tire to the crown (3) of the tire, iii) A third annular subassembly (23) called a “right lug” (23) that is axially adjacent to the center ring (21) on the side of the center ring (21) opposite in the axial direction to the side that receives the left lug (22), and comprises a portion of the crown zone (11) that extends axially, the second lateral zone (13) of the receiving surface (10_out) and the central portion of the crown zone (11) on the corresponding side of the center ring (21), and encloses the groove (15) that forms the passage for the stay (16) that connects the second side wall (7) of the tire to the crown (3) of the tire, The assembly comprises a plurality of annular subassemblies (21, 22, 23) having the following: The annular subassemblies (21, 22, 23), namely the central ring (21), the left lug (22), and the right lug (23), are each angularly divided into sectors (24, 25, 26, 27, 28, 29) azimuthally around the central axis (Z10), and alternating sectors called “keys” (24, 26, 28) are designed to be radially accessible from the inside with respect to the dismantling of the subassemblies (21, 22, 23) in question and to be removed first, and sectors called “bow-shaped segments” (25, 27, 29) are supported and locked in place by the keys (24, 26, 28) and are designed to be operable after they are released by the removal of the keys (24, 26, 28). The tool according to feature 2.

4. A side surface (40, 41) of at least one lug key (26, 28) that defines an angular sector (A26) occupied azimuthally by the lug key around the central axis (Z10), and thus the side surface (40, 41) of at least one lug key (26, 28) that interacts with a lug arch segment (27, 29) adjacent to the lug key (26, 28) in the annular subassembly (22, 23) and a dividing line (PJ) along the central axis The tool according to claim 3, wherein the line (Z10) is parallel to a virtual plane called the “sagittal meridian” (P_MER_26) which is a radial plane that intersects with the center of the angular sector (A26) occupied by the lug keys (26, 28) in question, and so the side surface (40, 41) allows the lug keys (26, 28) to be withdrawn from the adjacent lug arch segments (27, 29) by sliding and / or inclining along the dividing line (PJ).

5. The grooves (15) within a single lug sector (26, 27, 28, 29) are each separated by two transverse walls that are generated in the overall axial direction (DG_A) parallel to the central axis (Z10) or that form tapered surfaces extending from the bottom (19) of the groove to the receiving surface (10_out), thereby generating the "necessary crevice" by virtually moving the stay (16) in question along a virtual exit trajectory contained throughout the entire interior of the groove (15) in the overall axial direction (DG_A) parallel to the central axis (Z10). The tool according to any one of claims 3 and 4, characterized in that the groove (15) opens up free space that confines a virtual volume called the "rearrangement volume," thereby enabling the axial pull of the lug sector (26, 27, 28, 29) in question during an axial pull movement (M_A) that is guided parallel to the central axis (Z10) and toward the equatorial plane (P_EQ) of the core (10) without the side walls of the groove (15) interfering with the stay (16) during the axial pull movement (M_A).

6. The tool according to any one of claims 2 to 5, characterized in that the groove (15) is generated along a radial plane containing the central axis (Z10), thereby enabling the placement of a stay (16) extending along the radial plane within the tire (2).

7. The tool according to any one of claims 2 to 5, characterized in that the grooves (15) intersect in a cross shape on the receiving surface (10_out) so as to enable the intersecting stays (16) to be positioned inside the tire (2).

8. The tool according to claim 7 and 3, characterized in that each of the cross-intersecting grooves (15) within a single lug sector (26, 27, 28, 29) is contained in a radial plane intersecting the center of the lug sector in question, called the “sagittal meridian” (P_MER_26, P_MER_27), and is separated by two transverse walls generated in a diagonal overall direction (DG_O) that converge toward the central axis (Z10) in the direction from the lug (22, 23) in question toward the opposite lug (23, 22) and is non-zero and strictly less than 90 degrees, and forms an angle called the “colatitude angle” A44 with the central axis (Z10).

9. The sides (40, 41) and therefore the dividing line (PJ) that define the lag key (26, 28) in question are, i) in the first option, angled azimuthally offset with respect to the sagittal meridian plane (P_MER26) of the lag key (26, 28) by a value such that the cross-cross groove (16) that runs along the receiving surface (10_out) and the base profile (45) from the crown zone (11) to the lateral zone (12, 13) passes through opposing vertices of the grid units defined on the receiving surface (10_out) by a value such that the lag key (26, 28) is angled azimuthal offset with respect to the sagittal meridian plane (P_MER26) The tool according to claim 8, characterized in that it is generated in the diagonal overall direction (DG_O) based on the base profile (45) which corresponds to the intersection line (46) with the defined radial plane (P1, P2), or, in a second option, the base profile (45) which corresponds to the zigzag polyline (47) formed on the receiving surface (10_out) by the alternating edges of the units of the grid which are defined on the receiving surface by the cross intersection groove (15) and extend from the crown zone (11) to the transverse zones (12, 13).

10. The passage (15) for the stay (16) is separated by a side wall. The core (10) has a recess (50) behind the side wall, below the receiving surface (10_out), and penetrating between the passages (15), which is separated from the passages (15) by the side wall. The tool according to any one of claims 1 to 9.

11. The tool according to any one of claims 1 to 10, further comprising a barrier device (60) that interacts with the core (10) to prevent the entry of components forming the crown (3), side walls (6, 7), or bead (4, 5) of the tire into the passage (15) of the core (10) with which the stay (16) is engaged.

12. The crown (3) is suitable for forming a tread, and the tire (2) is provided with a first annular bead (4) and a second annular bead (5) designed to allow the tire (2) to be attached to a mounting support such as a rim, with the crown (3) together with a first side wall (6) and a second side wall (7) connecting the crown (3), the first and second side walls (6, 7), and the first and second beads (4, 5) as a whole form the tread of the tire (2). A donut-shaped tire (2) having a wall (8) with a concave inner surface (8_in) that defines a bead (9), wherein the tire (2) comprises reinforcing elements (16) called "stays" (16), each extending within the cavity (9) of the tire and connecting a crown fixing point (17) located on the crown (3) of the tire to a lateral fixing point (18) located on either the side wall (6, 7) or the bead (4, 5) of the tire, a method for manufacturing the donut-shaped tire (2), A preparation step (S0) in which the tool (1) according to any one of claims 1 to 11 is prepared, Step (S2) of arranging the stay (16) such that reinforcing threads (70) suitable for forming the stay (16) are passed through each passage (15) of the core (10), Next, in a filling step (S4), the components forming the crown (3), side walls (6, 7), and bead (4, 5) of the tire are placed on the receiving surface (10_out), Next, the curing stage (S5), Next, the core (10) is disengaged from the tire (2), and the stay (16) is left in a fixed position within the cavity (9) of the tire (2) in a demolding step (S6), A method characterized by comprising:

13. The method according to 12, wherein, following the preparation step (S0) and before the step (S2) in which the stay (16) is positioned, the fixing structure (71, 72) is laid on the lateral zone (12, 13) and the crown zone (11) of the receiving surface (10_out) of the core, facing the fixing point (18, 17) provided for attaching the stay (16) to the fixing point (18, 17) provided for attaching the stay (16) to the fixing point (18, 17) provided for attaching the stay (16) to the wall (8) of the tire, the fixing structure (71, 72) is laid on the lateral zone (12, 13) and the crown zone (11) of the receiving surface (10_out) of the core, wherein the fixing structure (71, 72) is laid on the lateral zone (12, 13) and the crown zone (11) of the receiving surface (10_out) of the core, facing the fixing point (18, 17) provided for attaching the stay (16) to the wall (8) of the tire, by sandwiching the end of the stay (16) between the fixing structure (71, 72) and the component so as to fix the stay (16) to the fixing point (18, 17) provided for attaching the stay (16) to the fixing point (18, 17) provided for attaching the stay (16) to the wall (8) of the tire, the fixing step (S1) is laid on the lateral zone (12, 13) and the crown zone (11) provided for attaching the stay (16) to the fixing point (18, 17) provided for attaching the stay (16) to the wall (8) of the tire, the fixing structure (71, 72) is laid on the lateral zone (12, 13) and the crown zone (11) provided for attaching the stay (16) to the fixing point (18, 17) provided for

14. The core (10) comprises a central ring (21) and left lugs (22) and right lugs (23) that enclose the passage (15) for a stay (16) in the form of a groove (15) opening onto the receiving surface (10_out), and each of the central ring (21) and lugs (22, 23) is angularly divided into sectors that form keys (24, 26, 28) alternating with arc-shaped segments (25, 27, 29), so the demolding step (S6) is a partial step of removing the central ring (21) so that the keys (24) of the central ring and then the arc-shaped segments (25) of the central ring are removed radially to release the lugs (22, 23), and then the keys (26) of one of the left and right lugs (22) are removed from the tire The present invention comprises a second partial step in which the arched segment (27) of the lug pulls out the first lug (22) which is pulled out of the cavity (9) of the tire, so as to release the corresponding portion of the cavity (9) and the stay (16) positioned in the corresponding portion of the cavity (9); and a third partial step in which the key (28) of the other lug pulls out the other lug (23) which is pulled out of the cavity (9) of the tire, so as to release the corresponding portion of the cavity (9) and the stay (16) positioned in the corresponding portion of the cavity (9), The sectors (26, 27, 28, 29) of each lug move in a way that depends on the arrangement of the lateral walls of the groove (15), i.e. i) When the lateral wall of the groove (15) is generated in the overall axial direction (DG_A) parallel to the central axis (Z10), in the axial translational extraction movement (M_A), ii) When the lateral wall of the groove (15) is generated in an oblique overall direction (DG_O) that intersects the central axis (Z10) at a non-zero acute colatitude angle (A44), in an oblique centripetal translational movement (M_O) that simultaneously has an axial component and a radial component, To be pulled out, The method according to claim 12 or 13, characterized by the features described herein.

15. After step (S2) of positioning the stay (16), the barrier device (60) is implemented, which, during the filling step (S4) and the curing step (S5), covers the passage (15) before the filling step (S4) and thus forms a screen between the passage (15) and the components of the wall (8) of the tire by applying masking elements (61, 63) such as a shell (61) and / or masking strip (63) to the receiving surface 10_out, or at least during the curing step (S5), the stay engaged with the passage (15) The method according to any one of claims 12 to 14, further comprising a protective step (S3) that interacts with the core (10) to prevent the entry of the components forming the crown (3), the side walls (6, 7), or the bead (4, 5) of the tire (2) into the passage (15) of the core (10) with the stay (16), by using a filling element (65) that temporarily fills the volume of each passage (15) leaving the space between the stay (16) and the opening of the passage (15) that appears on the receiving surface (10_out).

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