CORE FOR THE MANUFACTURE OF A REINFORCED BANDAGE WITH GUARDS, FEATURING A STOP COMPENSATOR INTENDED TO FACILITATE BANDAGE DEMOLDING

Abstract

The present invention relates to a tool (1) for manufacturing an object (2), such as a pneumatic tire, which comprises a wall (3) which delimits a cavity (4) and at least one stay which passes through the interior of the cavity (4) so ​​as to connect a first anchor point (M1) located in a first portion (3_1) of the wall (3) to a second anchor point (M2) which is located in a second portion (3_2) of the wall (3), said tool (1) comprising a core (10) provided with at least one groove (12) receiving the stay (5),as well as a compensator (20) which includes a stop (21) which is movably mounted in the groove (12) and which is supported by an elastic element (22) to ensure elastic suspension of the stay (5) in order to constitute a reserve of stay length which can be mobilized to allow the second portion (3_2) of the wall containing the second anchor point (M2) to move away from the first portion (3_1) of the wall containing the first anchor point (M1) when the core (10) is extracted from the cavity (4). Figure 6,

Description

Title of the invention: CORE FOR THE MANUFACTURE OF A TIRE REINFORCED BY SHUTTERS COMPRISING A COMPENSATOR WITH STOPS INTENDED TO FACILITATE THE DEMOLDING OF THE TIRE

[0001] The present invention relates to the general field of manufacturing objects by means of a molding core, in particular rubber-based objects, which objects comprise on the one hand a wall which delimits a cavity and on the other hand filiform reinforcements forming stays which extend through the cavity of the object in order to connect a portion of the wall to another portion of the wall.

[0002] The present invention relates more particularly to the manufacture of pneumatic tires which, to improve their drift behavior, are provided with stays which extend within the toric inflation cavity which delimits the tire, and which each connect a first anchoring point located in the top of the tire to a second anchoring point located in the sidewall or in the bead of the tire.

[0003] To manufacture such stay bandages, the applicant has already proposed, in application WO-2022 / 200718, a manufacturing tool comprising a toric core which has a shape matching that of the wall delimiting the cavity of the bandage, and in which grooves are hollowed out suitable for the passage of the stays.

[0004] Although such tooling is generally satisfactory, the inventors have nevertheless noted that the demolding step, during which the core is extracted from the cavity of the bandage, after curing said bandage, could present a certain complexity, in particular with regard to the need to subdivide the core into a plurality of elements, and to successively move these different elements along particular demolding trajectories to avoid any damage to the stays.

[0005] The objects assigned to the invention therefore aim to remedy the aforementioned drawbacks and to propose an improved manufacturing tool which makes it possible to manufacture an object reinforced by stays while simplifying the demolding of said object.

[0006] The objects assigned to the invention are achieved by means of a tool intended to manufacture an object, such as a pneumatic tire, which comprises on the one hand a wall which has a concave internal surface delimiting a cavity, and on the other hand at least one filiform reinforcing element, called a "stay", which passes through the interior of the cavity so as to connect a first anchoring point located in a first portion of the wall to a second anchoring point which is located in a second portion of the wall, at a non-zero distance from the first anchoring point, said tool comprising a core which materializes a volume called "reserved volume" which corresponds to the cavity of the object and which is delimited by a convex external surface, called "receiving surface", which receiving surface has a shape conjugated to the internal surface of the wall of the object, is intended to receive one or more constituent components of said wall of the object, and thus determines a distance called "base distance" between the first anchoring point and the second anchoring point, said core further comprising at least one groove which is hollowed out inside the reserved volume, from the receiving surface, so as to accommodate the stay, said tooling being characterized in that it comprises a compensator which comprises a stop which is intended to cooperate with the stay and which creates, inside the groove, a point called "intermediate passage point" which is located outside the fictitious straight line, called "base straight line",which passes through the first anchor point and the second anchor point, so that the length of the path followed by the stay in the groove, from the first anchor point to the second anchor point via the intermediate passage point defined by the stop, is strictly greater than the base distance, which allows the compensator to have a reserve of stay length which can be mobilized to allow the second portion of the wall containing the second anchor point to move away from the first portion of the wall containing the first anchor point when the core is extracted from the cavity,

[0007] Advantageously, the stop according to the invention allows the compensator to deflect the stay, during the initial insertion of said stay into the groove, relative to the most direct path that the stay could theoretically adopt, in the absence of a stop, between the first anchoring point and the second anchoring point.

[0008] The compensator thus stores in the groove an excess length of stay which corresponds to the difference between, on the one hand, the length of the effective path of the stay passing through the intermediate passage point created by the stop and, on the other hand, the theoretical minimum length, called the “base distance”, which said stay would travel if said stay followed a straight, direct path through the groove, between the first anchoring point and the second anchoring point, without making a detour via the intermediate passage point.

[0009] Advantageously, this excess length forms a reserve of stay which is in particular available at the time of demolding, and which allows the stay to accompany, without damage to said stay, a separation movement by which the first portion of the wall of the object, containing the anchoring point, is separated from the second portion of the wall of the object, in order to open the cavity more widely and thus allow the core to be extracted from said cavity.

[0010] Thus, the temporary increase, during demolding, of the distance which separates the first anchoring point from the second anchoring point can be compensated by the compensator according to the invention.

[0011] More generally, the configuration conferred by the stop on the path followed by the stay advantageously makes it possible to "unfold" or "straighten" the stay when the first anchoring point moves away from the second anchoring point, and thus to geometrically bring the path actually followed by the stay closer to a rectilinear path, here to geometrically bring the path actually followed by the stay closer to the fictitious straight line which joins, at the instant in question, and in particular at the time of demolding, the first anchoring point to the second anchoring point.

[0012] The compensator is thus capable of "giving slack" to the stay to adapt to the spacing which is required between the anchor points, at each instant considered, the apparent length of said stay which corresponds to the length measured, at the instant considered, in a straight line between the two ends of the stay formed by the anchor points, that is to say the length of the base of the fictitious triangle whose vertices are formed respectively by the first anchor point, the second anchor point, and the intermediate passage point.

[0013] The compensator according to the invention thus prevents the stay from being damaged or even broken under the tensile stress to which its anchor points subject it during demolding.

[0014] Advantageously, the implementation of a compensator according to the invention makes it possible in particular to envisage the extraction of the core from the cavity in an extraction direction relative to which the wall of the object initially forms an undercut face which, in the absence of a compensator allowing an elongation of the stay, and therefore in the absence of the possibility of separating the wall portions of the object from one another, would make extraction impossible, or at the very least impossible without damaging or even breaking the stay.

[0015] It will be noted that, preferably, the stop will be mounted movably in the groove and supported by an elastic member, so that said stop is capable of ensuring elastic suspension of the stay housed in the groove.

[0016] Advantageously, such a suspended arrangement makes it possible in particular to compensate, during demolding, for the temporary increase in the distance which separates the first anchoring point from the second anchoring point thanks to a movement of the stop which collapses elastically, against the elastic member which supports said stop, under the effect of the tension which is exerted on the stay, and more particularly under the effect of an increase in the tension which is exerted on the stay, when said stay is subjected to traction by its anchoring points.

[0017] More generally, this suspended arrangement makes it possible to “unfold” or “straighten” the guy line when the first anchor point moves away from the second anchor point, thanks to the fact that the intermediate passage point, defined by the movable stop, of the fictitious straight line which joins, at the instant considered, and in particular at the time of demolding, the first anchor point to the second anchor point, and therefore that we can geometrically bring the path which is actually followed by the stay closer to a straight path.

[0018] Other objects, characteristics and advantages of the invention will appear in more detail on reading the description which follows, as well as with the aid of the appended drawings, provided for purely illustrative and non-limiting purposes, among which:

[0019] [Fig.l] illustrates, in a perspective view with material cut away along a radial plane, an example of a braced pneumatic tire capable of being produced using a tool according to the invention.

[0020] [Fig.2] illustrates, in an exploded perspective view, an element of a tool for producing the bandage of [Fig.1].

[0021] [Fig. 3] illustrates, in a detailed sectional view, a stop arrangement, here a suspended stop arrangement, as used in the tooling of [Fig. 2], according to which the stop is formed by a ball and the elastic member by a helical spring, here stressed in compression.

[0022] [Fig. 4] illustrates, in a sectional view, a possible variant of the suspended stop arrangement, according to which the stop is formed by a ball and the elastic member by a torsion spring.

[0023] [Fig. 5] illustrates, in a partial sectional view in a radial plane, the initial configuration of the stay and the compensator during a step of making the bandage of [Fig. 1], the wall of the bandage matching the receiving surface of the core, and the suspended stop, with which each groove considered is equipped, deflecting the path followed by the stay to create a reserve of stay length in the groove concerned.

[0024] [Fig. 6] illustrates, in a partial sectional view in a radial plane, the configuration of the stay and the compensator during a demolding step during which the sides and the heels of the bandage are moved apart to move them away from the top of the bandage, which also has the effect of moving the heels apart from each other along the central axis of the bandage, so as to allow the core to be extracted from the cavity of the bandage, in an extraction direction perpendicular to the central axis, through the neck-shaped passage delimited by the sides and the heels of the bandage.During this stage, each stop concerned pushes against its elastic member to allow the stay to unfold in order to increase its apparent length and thus to adjust said apparent length to the distance which increases, under the effect of the deflection of the wall which allows the widening of the neck, between the first anchoring point located in the top and the second anchoring point located in the side.

[0025] [Fig.7] illustrates, according to a partial sectional view in a radial plane, the confi guration of the stay and the compensator at the end of the demolding step, the core being completely removed from the cavity of the bandage, the stay being thus completely removed from the groove, and the sides and the heels of the bandage having returned to their rest position, while, within the extracted core, the stop is, under the effect of the return exerted by the elastic member, in the rest position that said stop occupies in the absence of a stay pressing on said stop.

[0026] [Fig. 8] is a front view, in a plane normal to the central axis of the bandage, of a toric core used to manufacture the bandage of [Fig. 1] in accordance with the steps illustrated in Figures 5, 6 and 7, said core being subdivided, in azimuth around the central axis, into a succession of sectors forming keys and vaults, and said core being here in a configuration which corresponds to the step of demolding a first sector, forming a key, at the moment when said first sector crosses the neck formed by the sides of the bandage which are kept apart.

[0027] [Fig. 9] illustrates, according to a partial sectional view in a radial plane, during the demolding step of a first sector as illustrated in [Fig. 6], the configuration of the stays and the compensators in a second sector which is still in place within the cavity of the bandage, and which is distinct from and immediately adjacent to said first sector.

[0028] The present invention relates to a tool 1 intended to manufacture an object 2, such as for example a pneumatic tire 40 shown in [Fig.l].

[0029] Whatever the nature and the destination of the object 2, the object 2 targeted by the invention comprises, as is notably clearly visible in figures 1, 5, 6 and 7, on the one hand a wall 3 which has a concave internal surface 3_in delimiting a cavity 4, and on the other hand at least one filiform reinforcing element 5, called “stay” 5, which crosses the interior of the cavity 4 so as to connect a first anchoring point M1 located in a first portion 3_1 of the wall 3 to a second anchoring point M2 which is located in a second portion 3_2 of the wall 3, at a non-zero distance from the first anchoring point ML

[0030] The stay 5 advantageously forms an integral, permanent part of the structure of the object 2.

[0031] The stay 5 advantageously has a certain flexibility, so as to be able to flex without damage, in particular during the manufacture of the object 2, but a quasi-inextensibility in the direction of its length, considered from the first anchoring point M1 to the second anchoring point M2, so that, once the object 2 has its definitive functional configuration, typically once the pneumatic tire 40 is mounted on a rim and inflated to the required pressure, the stay 5 is in a taut state, extending rectilinearly from the first anchoring point M1 to the second anchoring point M2, and prevents the second portion 3_2 of the wall from the object to move away from the first portion 3_1 of said wall of the object, which makes it possible to stiffen the object 2. As indicated in the preamble, in the case where the object 2 is a pneumatic tire, the presence of the stay makes it possible to reduce the drift phenomenon linked to the elasticity of the sides of the tire.

[0032] Preferably, the stay 5 will be formed from a single-strand or multi-strand wire, made from one or more strands of textile material, polymer material such as aramid, or even metallic material. According to one possible embodiment, the stay 5 is made from a composite wire made from glass fibers and resin.

[0033] As an indication, the threadlike nature of the stay 5 is such that the length of the portion of the stay 5 which extends into the cavity 4, that is to say the length of the stay 5 considered along the path formed by the stay 5 from the first anchoring point M1 to the second anchoring point M2, is preferably at least ten times, preferably at least twenty times, or even at least fifty times greater than the maximum width of said stay, that is to say the largest dimension of the transverse section of the stay 5.

[0034] The stay 5 has at least one section which is embedded in the first portion 3_1 of the wall 3, so as to be integrated and fixed to said first portion 3_1 of the wall, and at least one other section which is embedded in the second portion 3_2 of the wall 3, so as to be integrated and fixed to said second portion 3_2 of the wall. It is then considered, by convention, that the first anchoring point M1 corresponds to the point on the internal surface 3_in of the wall 3 of the object at which the stay 5 emerges from the first portion 3_1 of the wall 3 to extend into the cavity 4 of the object, while the second anchoring point M2 corresponds to the point on the internal surface 3_in of the wall 3 of the object at which the stay 5 emerges from the second portion 3_2 of the wall 3 to extend into the cavity 4.

[0035] The invention is of course applicable to the manufacture of objects 2 which can be of varied nature, shapes and dimensions.

[0036] In particular, although the invention is particularly intended for the manufacture of pneumatic tires 40 intended to equip vehicle wheels, it could be envisaged to produce by means of the tool 1 and the method according to the invention other types of inflatable pneumatic structures, bands reinforced by stays 5, etc.

[0037] Whatever the shape or the destination of the object 2, the invention is more particularly applicable to the manufacture of objects 2 whose wall 3 is formed from rubber, and in particular applicable to a method of manufacturing an object 2 which firstly comprises a manufacturing step during which the wall 3 of the object 2 is shaped on the tool 1 from one or more components based on raw rubber, i.e. unvulcanized, then a curing step during in which the object 2 is baked in order to vulcanize said wall 3, then finally a demolding step during which the object 2 is separated from the tool 1, after the baking operation.

[0038] As is clearly visible in Figures 2, 5, 6 and 7, the tool 1 comprises a core 10 which materializes a volume 11, called “reserved volume” 11, which corresponds to the cavity 4 of the object 2 and which is delimited by a convex external surface 10_out, called “receiving surface” 10_out, which receiving surface 10_out has a shape conjugated to the internal surface 3_in of the wall 3 of the object 2, is intended to receive one or more constituent components of said wall 3 of the object, and thus determines a distance called “base distance” LO between the first anchoring point M1 and the second anchoring point M2.

[0039] Typically, the receiving surface 10_out will be intended to be covered by one or more rubber-based components, more particularly one or more raw rubber-based components, such as rubber strips or rubber sheets, which sheets and / or strips may possibly be provided with reinforcing threads embedded in a layer of rubber. Said components will be placed so as to match the shape of the receiving surface 10_out to form the internal surface 3_in of the wall 3 of the object 2.

[0040] The core 10 is preferably metallic, for example made of steel. Said core 10 thus offers a rigid and robust receiving surface 10_out, and can be reused sustainably, for the successive manufacture of a large number of objects 2.

[0041] As can be seen in particular in Figures 2, 5, 7 and 8, the core 10 comprises at least one groove 12 which is hollowed out inside the reserved volume 11, from the receiving surface 10_out, so as to accommodate the stay 5.

[0042] The groove 12 thus forms a slot which penetrates into the volume of the core 10 and which opens onto the receiving surface 10_out by a mouth 14 so that it is possible, before said groove 12 is covered and masked by components constituting the wall 3, to engage the stay 5 in said groove 12 simply by sliding said stay 5 into said groove 12, from the outside of the core 10, so that said stay 5 passes through the receiving surface 10_out through the mouth 14 to sink and lodge in the reserved volume 11, inside the core 10, and then remains inside the core 10 while the components of the wall 3 are placed on said core 10.

[0043] Preferably, the receiving surface 10_out is solid, outside the opening formed by the mouth 14 of the groove 12, respectively, if there are several grooves, outside the openings formed by said grooves.

[0044] Preferably, the groove(s) 12 are blind, that is to say that said grooves 12 have a solid bottom 13, located under the receiving surface 10_out, in the volume reserved 11.

[0045] Said solid bottom 13 extends from a first mouth portion 14A of the groove 12, which opens onto a first zone of said receiving surface 10_out intended to receive the first portion 3_1 of the wall 3, to a second mouth portion 14B of the groove 12, which opens onto a second zone of said receiving surface 10_out intended to receive the second portion 3_2 of the wall 3.

[0046] The groove 12, and more particularly the mouth 14 of said groove 12 by which said groove 12 opens onto the receiving surface 10_out, extends, at the receiving surface 10_out, continuously at least over the entire length of the receiving surface 10_out which goes from the first mouth portion 14A to the second mouth portion 14B. More particularly, the mouth 14 of the groove 12 extends, at the receiving surface 10_out, continuously from the position of the first anchoring point M1 to the position of the second anchoring point M2, considered when the first portion 3_1 of the wall and the second portion 3_2 of the wall of the object are in contact with the receiving surface 10_out, as is the case in [Fig.5].The first anchoring point M1 and the second anchoring point M2 are thus presented, during the step of making the object 2, and more particularly the wall 3 of the object 2, each facing a mouth portion 14A, 14B of the groove 12.

[0047] According to the invention, the tool 1 comprises a compensator 20 which comprises a stop 21 which is intended to cooperate with the stay 5 and which creates, inside the groove 12, a point M3 called the “intermediate passage point” M3 which is located in the groove 12 and outside the fictitious straight line D0, called the “base straight line” D0, which passes through the first anchoring point M1 and the second anchoring point M2, so that the length L5_tot of the path followed by the stay 5 in the groove 12, from the first anchoring point M1 to the second anchoring point M2 via the intermediate passage point M3 defined by the stop 21, is strictly greater than the base distance L0, which allows the compensator 20 to have a reserve of stay length, noted “Delta_L”,which can be moved to allow the second portion 3_2 of the wall containing the second anchoring point M2 to move away from the first portion 3_1 of the wall containing the first anchoring point M1 when the core 10 is extracted from the cavity 4.,

[0048] Thus, when inserting the stay 5 into the groove 12, then making the object 2 on the core 10, the stay 5 comes to bear against the stop 21, and therefore adopts a trajectory which is deviated from the shortest trajectory represented by the base line D0.

[0049] In practice, the base line D0 is defined by the nominal positions of the first and second anchor points M1, M2, that is to say by the positions occupied by the first and second anchoring point Ml, M2 during the making of the object 2, when the first wall portion 3_1 and the second wall portion 3_2 are in contact with the receiving surface 10_out of the core 10 so that the internal wall 3_in matches said receiving surface 10_out.

[0050] Geometrically, the compensator 20 makes it possible to create a triangle M1M2M3 whose first anchor point M1 and the second anchor point M2 respectively form a first vertex and a second vertex which define the base [M1M2] of said triangle, and whose intermediate passage point M3 defined by the stop 21 forms the third vertex.

[0051] In a particularly preferential manner, the stop 21 is adaptive, in that said stop 21 allows a variation in the position of the intermediate passage point M3 within the groove 12 in reaction to a variation in the intensity of the longitudinal tension which prevails in the stay 5, between the first anchoring point M1 and the second anchoring point M2.

[0052] This adaptive character may in particular be obtained by giving the stop 21 elastic behavior.

[0053] According to one possible implementation, this elastic behavior will allow the stop 21 to operate by a threshold effect, according to which said stop 21, depending on the stresses exerted on the stay 5, will be able to alternately either retain the stay 5 at an intermediate passage point M3, by resisting the movement of the stay 5, or on the contrary, by elastically retracting under the effect of a stress greater than a predetermined threshold, release and / or allow the stay 5 to pass to allow the latter to modify its position in response to the stress.

[0054] It would thus be possible, for example, to provide a stop 21 in the form of a curved spring blade, which would have a sole, fixed to a first lateral wall 15 delimiting the groove 12, and an arch carried by the sole and forming a bulge in the direction of a second lateral wall 16 delimiting the groove 12, opposite the first lateral wall 15, so that said arch, elastically deformable and forming at rest with the second lateral wall 16 a constriction which is narrower than the transverse dimension of the stay 5, could stop the sinking of the stay 5 into the groove 12 at the intermediate passage point M3, or even maintain the stay 5 at the intermediate passage point M3 by elastic pinching between the arch and the second lateral wall 16, and, when sufficiently intense traction is exerted on the stay 5, release said stay 5 and / or allow said stay 5 to to cross the constriction, or to go deeper into groove 12,either to extract itself from said groove 12.,

[0055] According to another possible implementation, to which reference will preferably be made in the following, the stop 21 is mounted movably in the groove 12 and is supported by an elastic member 22 so that said stop 21 is capable of ensuring an elastic suspension of the stay 5 housed in the groove 12.

[0056] According to such an arrangement, during the production of the object 2 on the core 10, the stay 5 comes to bear against the stop 21 and can push said stop 21 against the return force generated by the elastic member 22, over a pushing distance which depends among other things on the stiffness of said elastic member 22 and on the longitudinal tension which is exerted in the stay 5 during the installation of the stay 5.

[0057] When, after the wall 3 of the object has been formed on the core 10, the second portion 3_2 of the wall is forced apart from the first portion 3_1 of the wall, so as to straighten the wall 3 to further open the cavity 4 in order to allow the core 10 to pass through to carry out the demolding, as illustrated in [Fig. 6], an additional traction is generated on the ends of the stay 5 which are located respectively at the first anchoring point M1 and at the second anchoring point M2, and therefore the longitudinal tension in the stay 5 is increased.

[0058] In response, the compensator 20 releases all or part of the initially constituted reserve of stay length, allowing the stay 5 to unfold and straighten to the extent necessary to relieve this increase in longitudinal tension.

[0059] To do this, it is in particular possible for the adaptive stop 21 to move, or even completely release, the intermediate passage point M3, to allow the corresponding portion of the stay 5 to move closer to the fictitious straight line which connects the first anchoring point M1 to the second anchoring point M2 at the instant in question.

[0060] If the stop 21 is suspended elastically, the elastic member 22 deforms elastically, and thus allows the stop 21, and therefore the intermediate passage point M3, to move within the groove 12, which allows the stay 5 to unfold to the extent necessary to adapt at any time to the spacing distance which separates the first anchoring point M1 from the second anchoring point M2.

[0061] Thanks to this flexibility of the intermediate passage point M3, the compensator 20 is in fact able, geometrically, to bring the third vertex M3 closer to the base [M1M2] of the triangle M1M2M3, thus reducing the height of the triangle which comes from said third vertex M3 and perpendicular to the base [M1M2], and increasing the value of the angle at the vertex of said third vertex M3. This deformation of the triangle M1M2M3 makes it possible to increase the length of the base [M1M2] of the triangle to the extent necessary and sufficient to accompany the separation movement which moves the first anchor point M1 and second anchor point M2 away from each other.

[0062] It will also be noted that the compensator 20 here advantageously forms a tensioning device which, thanks to the return force exerted by the elastic member 22, makes it possible to keep the stay 5 in tension between the first anchoring point M1 and the intermediate passage point M3 on the one hand, and between the inter passage point median M3 and the second anchor point M2 on the other hand, that is to say to keep a stay 5 which is rectilinear per piece, on each of the two sides [M1M3], [M3M2] of the triangle which are formed by the stay 5 opposite the base [M1M2]. It will be noted that, here, the sides of the triangle which are occupied by the stay 5 preferably form the two small sides of said triangle, each being of length less than the length of the base [M1M2] which then forms the large side of the triangle.

[0063] Maintaining tension in the two pieces of the stay 5 forming the sides [M1M3] and [M3M2] makes it possible in particular to order the stay 5 within the groove 12, both during the manufacturing step, including the installation of the stay 5 and then the installation of the components constituting the wall 3 of the object 2, and during at least part of the demolding operation. This avoids in particular any risk of jamming or tangling of the stay 5, in particular during the demolding step.

[0064] According to the invention, the reserve of stay length, denoted “Delta_L”, is advantageously constituted by means of the compensator 20 during the initial insertion of the stay 5 into the groove 12, and is then available and usable by the compensator 20 to allow a variation, and more precisely an increase, of the distance which separates the second anchoring point M2 from the first anchoring point M1, in relation to what this distance is initially, namely in relation to the basic distance L0 which is initially defined by the core 10 during the step of making the wall 3.

[0065] It will be noted that, advantageously, the compensator 20 makes it possible not only to compensate for a forced increase in the distance separating the second anchoring point M2 from the first anchoring point M1, when such an increase is caused by the demolding operation, but also for a possible intrinsic shortening of the stay 5 which results from a thermal shrinkage of the stay 5, linked to the nature of the material(s) constituting the stay 5, and which is caused by a curing step which is carried out after the step of making the wall 3 and before the demolding step.

[0066] The stay length reserve Delta_L is equal to the difference between, on the one hand, the length L5_tot of the path followed by the stay 5 in the groove 12, from the first anchoring point M1 to the second anchoring point M2 via the intermediate passage point M3 defined by the stop 21, and on the other hand the basic distance L0: Delta_L = L5_tot - L0

[0067] In the aforementioned triangular configuration, according to which the stay 5 is stretched so as to form rectilinear segments from the first anchoring point M1 to the intermediate crossing point M3 firstly and then from the intermediate crossing point M3 to the second anchoring point M2, the maximum available stay length reserve Delta_L is, in absolute terms, the difference between, on the one hand, the cumulative length of the two pieces of stay forming the short sides [M1M3] and [M3M2] of the triangle and, on the other hand, the initial length of the base [M1M2]. of the triangle, it being recalled that said initial length of the base [M1M2] is the base distance LO as defined by the shape and dimensions of the core 10 and which separates the first anchoring point M1 located in the first wall portion 3_1 from the second anchoring point M2 located in the second wall portion 3_2 when said first and second wall portions 3_1, 3_2 match the receiving surface 10_out of said core 10.

[0068] Preferably, said stay length reserve Delta_L is between 3% and 30%, preferably between 8% and 20%, more preferably between 10% and 15%, of the basic distance L0.

[0069] Preferably, alternatively or cumulatively with the relative proportions indicated above, the stay length reserve Delta_L may be comprised, in absolute value, between 3 mm, minimum value, and 30 mm, maximum value, for example between 10 mm, minimum value and 18 mm, maximum value preferably between 12 mm and 15 mm.

[0070] This dimensioning of the Delta_L length reserve, and more particularly the low values ​​(minimum values) chosen for said Delta_L length reserve, advantageously makes it possible to have sufficient excess stay length 5 in stock in the groove 12, at the end of the manufacturing step and before the possible baking step and the demolding step, i.e. sufficient initial excess stay length, so that the stay 5 can then undergo without damage: - a possible intrinsic shortening of said stay 5 caused by thermal shrinkage, during the baking step, while the first and second anchoring points M1, M2 are held by the core 10 at a fixed distance from each other, in this case at the basic distance L0 from each other, and, above all, - an extension of the effective distance which separates the first and second anchoring points M1, M2, caused by the forced separation of the first and second wall portions 3_1, 3_2, when at least one of said first and second wall portions 3_1, 3_2 is detached and separated from the receiving surface 10_out of the core 10 during the demolding step.

[0071] This same dimensioning of the length reserve Delta_L, and more particularly the high values ​​(maximum values) chosen for said length reserve Delta_L, advantageously make it possible to limit the initial excess length of the stay 5 in such a way that, after the demolding operation, and once the object 2 has been placed in the functional configuration for which said object 2 is intended, for example once the object 2 has been mounted on a mounting support, such as a rim, and / or once the object 2 has been inflated by introducing a pressurized fluid into the cavity 4, then the wall 3, and more particularly the first wall portion 3_1 and the second wall portion 3_2, are in a configuration such that the initial excess length of the stay is absorbed, that is to say that the stay 5 extends in a rectilinear manner, and therefore in a substantially taut manner, in the cavity 4, from the first anchoring point M1 to the second anchoring point M2, and can thus exercise its stay function, by opposing the relative distance of the first and second anchoring points M1, M2, and therefore by retaining the second portion of wall 3_2 relative to the first portion of wall 3_1 and vice versa.

[0072] Preferably, the core 10 comprises a plurality of grooves 12 spaced apart from each other and each intended to accommodate a separate stay 5.

[0073] This makes it possible to equip the object 2 with a plurality of stays 5, each of which extends from a first anchoring point M1, distinct from the first anchoring points M1 of the other stays 5, to a second anchoring point M2, distinct from the second anchoring points M2 of the other stays 5. The object 2 thus has, as is notably the case in [Fig.l], a series of first anchoring points M1 and a series of second anchoring points M2, connected to each other by a series of stays 5, which ensures multi-point guying of the wall 3.

[0074] As indicated above, each of the grooves 12 of the plurality of grooves 12 advantageously has a mouth 14 which forms a continuous opening along the profile of the receiving surface 10_out, from the first portion of the wall 3_1 to the second portion of the wall 3_2, and more particularly from the first anchoring point M1 of the stay 5 associated with the groove 12 considered to the second anchoring point M2 of said stay 5.

[0075] When the core 10 comprises a plurality of grooves 12, the compensator 20 then preferably comprises, as is notably visible in [Fig.2], a plurality of stops 21, each of said stops 21 being intended for one of said grooves 12. Each stop 21 can of course preferably be supported by an elastic member 22.

[0076] Thus, each stay 5 will be offered a passage point M3 giving said stay 5 a reserve length, which will be usable in particular during the demolding operation.

[0077] Even more preferably, each stop 21 is supported by its own elastic member 22, distinct from the elastic members 22 associated with the other stops 21, to ensure individual elastic suspension of each stay 5, independent of the suspension of the other stays 5.

[0078] This being the case, it is not excluded to envisage a collective elastic member 22, shared by several movable stops 21.

[0079] It will be noted that, in the present application, reference is preferably made, for convenience of description, to a groove 12 in particular, and to the corresponding stay 5, it being understood that the considerations and characteristics applicable to a groove 12 can preferably apply, in an analogous manner, to several grooves 12, preferably to all the grooves 12 of the core 10, and to the corresponding stays 5.

[0080] Preferably, the groove 12 is delimited by two solid side walls 15, 16 which face each other, which intersect the receiving surface 10_out and which define between them a groove width W12 which is sufficient to allow the free passage of the transverse section of the stay 5.

[0081] Each of said side walls 15, 16 preferably extends continuously from the mouth 14 of the groove 12 to the bottom 13 of said groove 12.

[0082] Said side walls 15, 16, which can preferably be parallel to one another, advantageously make it possible to guide the stay 5 inside the groove 12, and to limit the transverse movement of said stay 5, in particular when said stay 5 is engaged with the movable stop 21.

[0083] For information purposes, the largest dimension of the cross-section of the stay 5, i.e. the diameter of the stay 5 when said stay 5 is formed by a wire or a cable having a cross-section of circular shape, is between 0.3 mm and 3 mm, for example between 0.8 mm and 1.2 mm.

[0084] In practice, the width W12 of the groove 12 will be chosen to be equal to or greater than the largest transverse dimension of the stay 5, for example between 101% and 160% of the largest transverse dimension of the stay 5, for example between 110% and 150%, or even between 110% and 130%, for example equal to 120% of the largest transverse dimension of the stay 5.

[0085] More particularly, the diameter of the stay 5 being known, it will be possible to apply a dimensioning rule which will consist of choosing a groove width W12 equal to the diameter of the stay 5 increased by 10% to 30%, for example increased by 20%.

[0086] As an indication, alternatively or cumulatively with the ranges of relative values ​​mentioned above, the width W12 of the groove 12 may be comprised, in absolute value, between 0.3 mm and 3 mm, preferably between 0.8 mm and 2.2 mm, for example between 1 mm and 1.8 mm, or even between 1.1 mm and 1.3 mm.

[0087] Preferably, the stop 21 is formed by a ball 23 whose diameter is strictly greater than the width W12 of the groove 12 and which is guided in sliding in a chamber 24 which communicates with said groove 12 by a slot 25 which allows the stay 5 to engage the stop 21, as is notably visible in figures 2, 3, 4 5 and 6.

[0088] The stop 21 thus forms a slider which is mounted mobile and guided in the chamber 24, here in rectilinear translation.

[0089] The slot 25 preferably has a width equal to the width W12 of the groove, or possibly slightly greater than the width W12 of the groove, but in in all cases strictly less than the diameter of the ball 23, and more preferably strictly less than the radius of the ball 23, so that the ball 23 remains captive in the chamber 24 without being able to pass through the slot 25, and that the slot 25 is superimposed on the groove 12 to allow the stay 5 to slide into the chamber 24 in order to come to bear against the stop 21 while being guided by the slot 25. The stay 5 can thus slide in the slot 25, and more generally in the groove 12, along the side walls 15, 16, without risk of jamming, when the stop 21 moves under the combined action of a longitudinal traction exerted on the stay 5 and the return force exerted by the elastic member 22.

[0090] Of course, a slider of a shape other than a ball 23 could be used as a stop 21, provided that this shape is suitable for sliding, here rectilinear, and that the slider has a width greater than the width of the slot 25, to remain captive in the chamber 24. For example, a rectangular parallelepiped with rounded corners and edges, mounted to slide in the chamber 24, could be used as a stop 21.

[0091] However, the use of a ball 23 has several advantages, including simplicity of implementation, a rounded contact surface which does not risk damaging the stay 5 by abrasion or cutting the stay 5, and a spherical shape which ensures sliding of the stop 21 inside the chamber 24 without jolts or seizure.

[0092] The direction D21 of movement of the stop 21, and more particularly the direction of translation of the cursor formed here by the ball 23, such that this direction of translation is defined by the chamber 24, is preferably parallel to the side walls 15, 16 of the groove 12, and perpendicular or substantially perpendicular (at + / - 5 degrees, for example) to the base line D0.

[0093] Such an arrangement is both simple, robust, and well suited to optimizing the sensitivity of the compensator 20 to variations in longitudinal traction which affect the stay 5.

[0094] It is of course possible to envisage different types of elastic members 22. According to one possibility illustrated in [Fig.4], the elastic member 22 can be formed by a torsion spring 26, one branch of which supports the stop 21, here the ball 23, against the stay 5.

[0095] However, according to a preferred arrangement, the elastic member 22 is formed by a helical spring 27, as illustrated in FIGS. 2, 3, 5, 6 and 7.

[0096] Such an arrangement is in fact particularly simple, compact and inexpensive.

[0097] Furthermore, it makes it possible to easily choose a stiffness of the elastic member 22 which is adapted to the stay 5 and the core 10 used.

[0098] Preferably, the prestress of the elastic member 22 can be adapted, which is here a prestress in compression against the stop 21 and therefore against the insertion of the stay 5, by means of a setting screw which axially compresses the helical spring 27 within the chamber 24, against the ball 23.

[0099] In this respect, it will be noted that provision may be made to close the chamber 24 by means of a threaded cylinder head which will provide a dual function by forming, opposite the slot 25, on the one hand a closure member having the function of preventing the elastic member 22, here the helical spring 27, as well as the stop 21, here the ball 23, from escaping from the chamber 24, and on the other hand a calibration screw having the function of adjusting the compression prestress of the elastic member 22, here the helical spring 27.

[0100] The prestress of the elastic member 22 may preferably be chosen equal to or greater than the foreseeable intensity of the force that the stay 5 exerts on the stop 21, against said elastic member 22, when the stay 5 is placed in the groove 12, due to the longitudinal tension that the installation device exerts on the stay 5. Thus, the stop 21 will be able to resist being pushed in during the operation of installing the stay 5, and will only give way and push in, against the elastic member 22, at the time of the demolding operation, when the longitudinal tension in the stay 5 is increased by pulling on the second wall portion 3_2. Thus, it will be possible to advantageously define precisely, and in a reproducible manner, the position of the intermediate passage point M3 when the stay 5 is placed.

[0101] Here, said intermediate passage point M3 will in fact initially correspond to the rest position of the ball 23 when said ball 23 is pressed against the bottom of the chamber 24, opposite the opening of the slot 25, by the helical spring 27.

[0102] In practice, the prestress of the elastic member 22, and therefore here more particularly the prestress which presses the ball 23 into the bottom of the chamber 24, awaiting the stay 5, may be between 2 Newtons and 50 Newtons, for example between 8 Newtons and 15 Newtons, or more particularly between 10 Newtons and 12 Newtons.

[0103] Preferably, the intermediate passage point M3 defined by the stop 21 is, as is clearly visible in [Fig.5], located in a zone which is strictly between the base line D0 on the one hand and the outline of the receiving surface 10_out onto which the groove 12 opens on the other hand.

[0104] Thus, when the stay 5 is inserted into the groove 12, by exerting a slight longitudinal tension in said stay 5 and forcing said stay 5 to pass through the first anchoring point M1 and the second anchoring point M2, then the interception of the stay 5 by the stop 21 occurs automatically, slightly below the receiving surface 10_out, thus imposing a bend on the stay 5, at the intermediate passage point M3, so that the stay 5 cannot reach a direct rectilinear configuration between the first anchoring point M1 and the second anchoring point M2, that is to say so that the stay 5, although passing through the first and second anchoring points anchor line Ml, M2, cannot come to stretch completely and merge with the base line DO.

[0105] If the stop 21 is suspended, the elastic member 22 is then preferably arranged so as to be able to push the stop 21 against the stay 5, in the direction of the receiving surface 10_out.

[0106] Advantageously, this configuration allows the elastic member 22, here the helical spring 27, to work in compression, in a stable and robust manner, against the stay 5, and to use the stop 21, here the ball 23, as a pusher which tends to elastically return the stay 5 in the direction of the mouth 14 of the groove 12, and therefore in the direction of the receiving surface 10_out, opposite the bottom 13 of the groove 12.

[0107] The depression of the stop 21, here along the direction of movement D21 imposed by the configuration of the chamber 24 which guides the stop 21, automatically adapts to the intensity of the longitudinal tension which is exerted in the stay 5, thus allowing the compensator 20 to dynamically accommodate the variations in length imposed on the stay 5.

[0108] More particularly, during the initial installation of the stay, the stop 21 sinks to a first degree of sinking, which may be substantially zero, and which it maintains while the components of the wall 3 are placed on the core, as can be seen in [Fig. 5], then, when the second portion of the wall 3_2 is moved away from the first portion of the wall 3_1 in order to proceed with the demolding, the stop 21 sinks further by compressing the elastic member 22, to reach a second degree of sinking, greater than the first degree of sinking, which makes it possible, as illustrated in [Fig. 6], to reposition the intermediate passage point M3 so as to unfold the stay 5 to accompany the increase in the distance which separates the first anchoring point M1 from the second anchoring point M2.

[0109] Preferably, as illustrated in [Fig.2], the compensator 20 comprises a cartridge 30 which is inserted removably into the core 10 in a direction D30 called the “insertion direction” D30 which is transverse to the side walls 15, 16 delimiting the groove 12, and more preferably, when the core 10 comprises a series of several grooves 12, which is transverse to the side walls 15, 16 delimiting the different grooves 12.

[0110] The cartridge 30 comprises a chamber 24 which contains a stop 21, preferably a ball 23, moved by an elastic member 22, preferably a helical spring 27, said chamber 24 being provided with a slot 25 which is arranged, here transversely to the insertion direction D30, to align with the groove 12 of the core 10 in order to allow the stay 5 to reach the stop 21 located in said chamber 24.

[0111] More preferably, in the case of a plurality of grooves 12, the cartridge 30 comprises a plurality of chambers 24 each containing a stop 21, preferably a ball 23, moved by an elastic member 22, preferably a helical spring 27, each chamber 24 being provided with a slot 25 which is arranged to align with the corresponding groove 12 of the core 10 in order to allow the stay 5 concerned to reach the stop 21 located in said chamber 24.

[0112] The cartridge 30 is thus in the form of a slotted cage 25, which is inserted through the core 10 to position the stops 21, here the balls 23, opposite each groove 12.

[0113] Preferably, each chamber 24 contains the elastic member 22 specific to the stop 21 concerned. Thus, the cartridge 30 will ensure individual elastic suspension of each stop 21, and therefore of each corresponding stay 5.

[0114] Preferably, the chamber 24 will form a bore arranged to receive on the one hand the ball 23 and on the other hand the helical spring 27 which pushes said ball 23 in the direction of the slot 25, and therefore against the stay 5.

[0115] According to one possible arrangement, the stops 21 and the elastic members 22 may be held in place inside the cartridge 30 by the solid part of the core 10 itself. For this purpose, the positioning of the cartridge 30 will be carried out by iterations, each iteration comprising: a first step during which an assembly formed of a stop 21, here a ball 23, and an elastic member 22, here a helical spring 27, is introduced into the chamber 24 closest to the core 10, then a step during which the cartridge 30 is pushed inside the core 10, in the insertion direction D30, over a distance which corresponds to the spacing between two successive chambers 24. The operation will be repeated as many times as there are chambers 24 to be filled.

[0116] According to another possible arrangement, each of the chambers 24 can be closed by means of a threaded cylinder head, which will be screwed into the cartridge 30, at a threaded end of the chamber 24, after the stop 21, here the ball 23, and the elastic member 22, here the helical spring 27, have been introduced into said chamber 24. The threaded cylinder head will thus provide support for the elastic member 22, here the helical spring 27, at one end of said elastic member 22 located opposite the end supporting the stop 21. Once the cartridge 30 is fitted with its stops 21 and elastic members 22, held by the threaded cylinder heads, the cartridge 30 as a whole can be inserted into the core 10.

[0117] Such an arrangement makes it possible on the one hand to easily handle the cartridge 30 without the risk of losing balls 23 or springs 27, since the threaded cylinder heads which close the chambers 24 retain these elements inside said chambers 24, and on the other hand to carry out individual calibration of each elastic member 22, since the insertion of each threaded cylinder head into the corresponding chamber 24, by screwing, makes it possible to increase the compression prestress of the elastic member 22, here of the helical spring 27.

[0118] In a particularly preferential manner, the tool 1 will be intended for the manufacture of a toroidal bandage 40, such as that illustrated in [Fig.l], said toroidal bandage 40 comprising a crown 41 intended to form a tread, a first annular bead 42 and a second annular bead 43 designed to allow the bandage 40 to be attached to a mounting support such as a rim, as well as a first sidewall 44 and a second sidewall 45 which connect the crown 41 respectively to the first bead 42 and to the second bead 43; the crown 41, the first and second sidewalls 44, 45 and the first and second beads 42, 43 form as a whole the wall 3 having the concave internal surface 3_in which delimits the cavity 4 of the bandage 40.

[0119] The receiving surface 10_out of the core 10 then has, as can be seen in FIGS. 5, 6 and 7, a toroidal shape which is centered on a central axis Z10 and which comprises a radially external top zone 51 intended to receive components constituting the top 41 of the tire 40, and, on either side axially of said top zone 51, a first lateral zone 52 folded back towards the central axis Z10 and intended to receive components constituting the first flank 44 and the first heel 42 as well as a second lateral zone 53 folded back towards the central axis Z10 and intended to receive components constituting the second flank 45 and the second heel 43.

[0120] It will be noted that, in a manner known per se, the first and second heels 42, 43 will preferably each contain at least one rod, for example formed by a braid of one or more metal wires or by turns of continuous wire wound around the central axis Z10, so that each rod will form, around the central axis Z10, an annular reinforcement whose circumference is almost inextensible.

[0121] The toroidal core 10 will advantageously be divided into juxtaposed sectors 54, 55, each occupying a predetermined angular sector in azimuth around the central axis Z10, as can be seen in [Fig.8].

[0122] This succession of sectors 54, 55 comprises, alternately, sectors 54 called “keys” 54, designed to be accessible by radially internal approach and to be removed first during the disassembly of the core 10 carried out during the demolding operation, and sectors 55 called “vaults” 55 which are supported and locked in position by the keys 54 and designed to become maneuverable after they have been released by the removal of the keys 54.

[0123] According to a possible arrangement, the sectors 54, 55 could themselves be axially divided into three blocks, as described in application WO-2022 / 200718 mentioned in the preamble, namely: - a first block called the “central block” which forms a central portion of the zone summit 51 of the receiving surface 10_out, all of the central blocks forming a crown called the “central crown”, - a second block called the “left ear” which is axially attached to the first block, said left ear 22 comprising the first lateral zone 52 of the receiving surface 10_out as well as a portion of the top zone 51 which axially extends the central portion of the top zone carried by the central block, on the corresponding side of said central block, - a third block called the “right ear” which is axially attached to the central block, on the side of the central block which is axially opposite the side receiving the left ear, said right ear comprising the second lateral zone 53 of the receiving surface 10_out as well as a portion of the top zone 51 which axially extends the central portion of the top zone 11 on the corresponding side of the central block.

[0124] However, according to a preferred embodiment, each sector 54, 55 may be monolithic, in that it extends in one piece over the entire axial width of the core 10, from the first lateral zone 52 inclusive to the second lateral zone 53 inclusive, including the summit zone 51, thus providing a sector 54, 55 which has, in section in a radial plane containing the central axis Z10, a Q (capital Omega) section, as can be seen in FIGS. 5, 6 and 7. In practice, the implementation of a monolithic sector 54, 55 amounts to merging into a single piece the different constituent blocks of a sector 54, 55 as described in application WO-2022 / 200718, namely the left ear, which will here form a first lobe 17, the central block, and the right ear, which will form a second lobe 18 here.

[0125] It will be noted that, for simplicity of representation, [Fig. 2] represents a portion of a sector 54, 55, which may correspond in practice to an ear within the meaning of application WO-2022 / 200718. Of course, the arrangement illustrated in [Fig. 2], namely the implementation of a cartridge 30 as described above, may be found in a similar manner within a monolithic sector 54, 55, by providing a cartridge 30 for each portion of the monolithic sector 44, 45 fulfilling the function of an ear, and therefore ultimately by providing two cartridges 30 for each monolithic sector 54, 55, as appears in FIGS. 5, 6 and 7.

[0126] Preferably, the toroidal core 10 will be divided into twenty sectors 54, 55 around the central axis Z10, even more preferably into ten sectors 54, 55 at the rate of five keys 54 and five vaults 55, as illustrated in [Fig.8].

[0127] The core 10 intended to manufacture a toroidal bandage 40 comprises a plurality of grooves 12 which are distributed in azimuth around the central axis Z10, as is clearly visible in [Fig.8], and which are arranged to allow the passage, through the cavity 4, of stays 5 which each connect, as is notably clearly visible in [Fig.l], a first anchoring point M1 called the “summit anchoring point” which is located in the top 41 of the bandage 40 to a second anchoring point M2 called “lateral anchoring point” which is located in one of the sides 44, 45 or the heels 42, 43 of the bandage 40.

[0128] Thus, in this particular case, the first portion 3_1 of the wall 3 mentioned above will correspond to the top 41 of the bandage 40, while the second portion 3_2 of the wall 3 will correspond to one of the sides 44, 45 or to one of the heels 42, 43 of the bandage 40.

[0129] Preferably, the first anchoring point M1 and the second anchoring point M2 associated with the same stay 5, and therefore with the same groove 12, are located at the same azimuthal position around the central axis Z10. The base line D0 associated with said groove 12 is then, in this case, contained in a radial plane containing the central axis Z10 of the core 10.

[0130] The compensator 20 advantageously associates with each groove 12 of the plurality of grooves 12 of the core 10 intended to manufacture a toroidal bandage 40 a stop 21, preferably suspended by an elastic member 22, in order to create a reserve of stay length Delta_L in said groove 12.

[0131] Thus, in each groove 12, there is a stop 21 capable of positioning the stay 5 housed in the groove 12, at a point called the “intermediate passage point” M3 which is located in the groove 12 and outside the fictitious straight line, called the “base straight line” D0, which passes through the first anchoring point M1 and the second anchoring point M2, so that the length L5_tot of the path followed by the stay 5 in the groove 12, from the first anchoring point M1 to the second anchoring point M2 via the intermediate passage point M3 defined by the stop 21, is strictly greater than the base distance L0 which is defined between the first and second anchoring points M1, M2 by the core 10, for the stay 5 considered, which allows the compensator 20 to have, for each stay 5, a reserve of stay length which can be mobilized to allow flank 44, 45 or heel 42,43 containing the second anchor point M2 to move away from the vertex 41 containing the first anchor point M1 when the core 10 is extracted from the cavity 4.,

[0132] Preferably, in each groove 12 there is a stop 21 formed by a ball 23, which is mounted movably in said groove 12 and which is here supported by an elastic member 22, preferably a helical spring 27, so that said stop 21 is capable of ensuring elastic suspension of the stay 5 at the intermediate passage point M3.

[0133] It will be noted that, preferably, the first heel 42 and the second heel 43 form, in section in a radial plane containing the central axis Z10, and with respect to the axially widest part of the cavity 4, a constriction, so that the first flank 44 and the second flank 45 form undercut faces with respect to the direction extraction direction D_extract of the sector 54, 55 considered, extraction direction D_extract which, as can be seen in Figures 6 and 8, is here perpendicular to the central axis Z10, and contained in the bisector plane of the sector 54, 55 considered, that is to say the radial plane called the “median radial plane” which contains the central axis Z10 as well as the bisector of the angle covered, around the central axis Z10, by the sector 54, 55 considered.

[0134] In this case, the demolding operation requires axially separating the first heel 42 and the second heel 43 from each other, to allow the passage of the sector 54, 55 which is to be extracted.

[0135] In this respect, the separation of the beads 42, 43 can be caused simply by forcing the elastic deformation of the first and second flanks 44, 45 of the tire under the effect of the thrust of the first and second lobes 17, 18 of the sector 54, 55 which executes the centripetal radial extraction movement, relative to the tire 40, in the extraction direction D_extract. In this case, the first and second flanks 44, 45 and / or the first and second beads 42, 43 can slide on the lobes 17, 18, remaining in contact with the receiving surface 10_out, at least at the start of the extraction movement, as illustrated in [Fig.6].

[0136] Optionally, it could be envisaged to actively detach the first heel 42 from the first lateral zone 52 of the receiving surface 10_out while, simultaneously, detaching the second heel 43 from the second lateral zone 53 of the receiving surface 10_out, by exerting on said first and second heels 42, 43 opposite traction forces, in order to open a passage of suitable width in front of the sector 54, 55 concerned. For this purpose, it could for example be possible to force the separation of the heels using a suitable traction tool, distinct from the sector 54, 55 considered and engaging on said heels 42, 43.

[0137] It will also be noted that, due to the continuity of material of each of the first and second heels 42, 43 around the central axis Z10, the fact of locally moving a heel 42, 43 away from the position that said heel 42, 43 initially occupies on the receiving surface 10_out of the core, in the angular range occupied by the sector 54, 55 that it is desired to extract from the cavity 4 of the bandage 40, also has the effect of moving this same heel 42, 43 away from the receiving surface 10_out in the neighboring sectors 54, 55, as illustrated in [Fig.9].

[0138] Of course, the spacing of the heels 42, 43, regardless of the way in which the spacing is caused or the sector 54, 55 concerned by said spacing, must not cause any damage to the bandage 40 or to the stays 5. In particular, the spacing of the heels 42, 43 must not cause any weakening or tensile breakage of the stays 5, nor tearing of their anchoring points M1, M2.

[0139] Now, advantageously, the compensator 20 is capable of restoring, when necessary, all or part of the reserve of stay length that said compensator 20 has formed within the groove 12, and thus allows all the stays 5 concerned to adapt without damage to the variations, and more specifically to the increases, in the distance which separates the first and second anchoring points M1, M2, variations which are induced by the displacement of the heel 42, 43 concerned.

[0140] This compensation, and more particularly the unfolding of the stay 5, can advantageously occur in the sector 54, 55 which executes the demolding movement in the extraction direction D_extract, while the top zone 51 of said sector 54, 55 detaches and moves away from the internal wall 3_in of the top 41 of the bandage, as illustrated in [Fig. 6], but also in the sectors 55, 54 which are immediately adjacent to said sector executing the demolding movement, while said neighboring sectors 55, 54 are still in place in the cavity 4 of the bandage, the top zone 51 of each of said neighboring sectors 54, 55 still being in contact with the internal wall 3_in at the top 41 of the bandage, but the heels 42, 43 of said neighboring sectors 55, 54 are separated and thus detached from the zones lateral 52, 53 of the receiving surface 10_out, as illustrated in [Fig.9].

[0141] Advantageously, the compensator 20 therefore allows all the stays 5 concerned to adapt flexibly to the traction, induced by the movement of the heel 42, 43, which is specific to them, both in the sector 54, 55 which executes the demolding movement in the extraction direction D_extract and in the sectors 54, 55 which are immediately adjacent to said sector executing the demolding movement.

[0142] It will also be noted that the differential movement of the stop 21 relative to the core 10, permitted by the deformation of the elastic member 22, can advantageously be carried by a direction of movement D21 which is not parallel to the extraction direction D_extract followed by the core 10.

[0143] Of course, the invention also relates to a method of manufacturing an object during which a tool 1 according to the invention is used.

[0144] According to this manufacturing method, a stay 5 is placed in each groove 12 of the core 10, against the stop 21, here preferably against the stop 21 which is supported by the elastic member 22, then at least one component is placed on the receiving surface 10_out to form the wall 3, then the object 2 is demolded by separating from each other a first portion of the wall 3_1 containing a first anchoring point M1 of the stay 5 and a second portion of the wall 3_2 containing a second anchoring point M2 of the stay 5, to allow the extraction of the core 10 from the cavity 4 delimited by the wall 3.

[0145] Preferably, when installing the stay 5, a longitudinal tension is exerted on the stay 5, between the first anchoring point M1 and the second anchoring point M2, so that the path followed by the stay 5 within the groove 12 forms a broken line, rectilinear in pieces, the intermediate passage point M3 of which forms a summit.

[0146] This positioning of the stay 5 against the stop 21 can cause a certain recoil of said stop 21, in the direction D21 of movement, to the extent necessary to allow the force exerted by the elastic member 22 on the stop 21 to balance the force exerted by the stay 5 on the stop 21.

[0147] The stay 5 is preferably fixed to the receiving surface 10_out of the core, by attaching the stay 5 to anchoring structures pre-arranged on the receiving surface 10_out and intended to permanently integrate the wall 3 of the object 2, so as to form the first and second anchoring points M1, M2. This makes it possible to keep the stay 5 in tension while the core 10 is covered with components constituting the wall 3. According to a preferred implementation possibility, the anchoring structures will be formed by adhesive strips, for example strips of raw rubber, arranged on the core 10 respectively near the first mouth portion 14A through which the stay 5 enters the groove 12 and near the second mouth portion 14B through which the stay 5 emerges from the groove 12, adhesive strips against which the stay 5 will be pressed, or even in which the stay 5 will be buried.

[0148] Of course, the wall 3 will be sufficiently flexible, and more preferably elastically flexible, to tolerate the spacing necessary for the extraction of the core 10.

[0149] Preferably, the manufactured object 2 is a bandage 40, more preferably a toroidal bandage 40, the wall 3 of which is formed from one or more rubber-based components.

[0150] In this case, in accordance with the manufacturing method, the stays 5 are placed on the core 10, in the grooves 12, said rubber-based component(s) intended to form the wall are placed in the raw state on the receiving surface 10_out of the core, then the core 10 furnished with the stays 5 and the wall 3 is subjected to a curing operation making it possible to vulcanize the rubber-based component(s) of the wall, then the bandage 40 is demolded by separating, by elastic deformation, the second portion of the wall 3_2 from the first portion of the wall 3_1 and by extracting the core 10 from the cavity 4 delimited by said wall 3.

[0151] In the case of a toroidal bandage 40, this will allow in particular, by axially separating the flanks 44, 45 and the heels 42, 43 of the bandage to enlarge the neck delimited by said heels 42, 43, to clear a sufficient passage to extract the core 10, here the sector 54, 55 concerned from said core 10, through said neck according to a centripetal radial demolding movement.

[0152] Of course, the invention is in no way limited to the sole embodiments described in the foregoing, the person skilled in the art being able in particular to isolate or freely combine one or other of the aforementioned characteristics, or to substitute equivalents for them.

[0153] In particular, as an alternative to the installation of raw rubber-based components and the aforementioned curing step, it could be envisaged to produce all or part of the object 2, and in particular all or part of the crown 41, the sides 44, 45 and / or the heels 42, 43 of the bandage 40, by injection of a thermoplastic elastomer material, after having dressed the core 10, carrying the stays 5, by means of an appropriate injection mold.

[0154] The cooking step will then be replaced by a cooling step allowing the thermoplastic elastomer material to be brought to a solid and elastic state.

[0155] It would of course be possible to envisage a mixed process, combining a filling phase where solid rubber-based elements are placed on the core 10, and a phase of injecting thermoplastic elastomer material. The curing step could then occur before, simultaneously with, or after the phase of injecting thermoplastic elastomer material.

[0156] In all cases, the method then comprises, once the object 2 has been produced, here once the bandage 40 has been produced, a demolding step during which the core 10 is released from the cavity 4 of the object 2 while leaving the stays 5 in place in said cavity 4, as is notably illustrated in the sequence of figures 5, 6 and 7.

Claims

Claims

1. Tool (1) intended to manufacture an object (2), such as a pneumatic tire, which comprises on the one hand a wall (3) which has a concave internal surface (3_in) delimiting a cavity (4), and on the other hand at least one filiform reinforcing element (5), called a "stay" (5), which passes through the interior of the cavity (4) so as to connect a first anchoring point (Ml) located in a first portion (3_1) of the wall (3) to a second anchoring point (M2) which is located in a second portion (3_2) of the wall (3), at a non-zero distance from the first anchoring point (Ml), said tool (1) comprising a core (10) which materializes a volume, called a "reserved volume" (11), which corresponds to the cavity (4) of the object (2) and which is delimited by a convex external surface, called a "receiving surface" (10_out), which receiving surface (10_out) has a shape conjugate to the internal surface (3_in) of the wall (3) of the object (2),is intended to receive one or more constituent components of said wall (3) of the object (2), and thus determines a distance called the “base distance” (LO) between the first anchoring point (Ml) and the second anchoring point (M2), said core (10) further comprising at least one groove (12) which is hollowed out inside the reserved volume (11), from the receiving surface (10_out), so as to accommodate the stay (5), said tool (1) being characterized in that it comprises a compensator (20) which comprises a stop (21) which is intended to cooperate with the stay (5) and which creates, inside the groove (12), a point called the “intermediate passage point” (M3) which is located outside the fictitious straight line, called the “base straight line” (DO), which passes through the first anchoring point (Ml) and the second anchoring point (M2), so that the length (L5_tot) of the path followed by the stay (5) in the groove (12),from the first anchor point (Ml) to the second anchor point (M2) via the intermediate passage point (M3) defined by the stop (21), or strictly greater than the base distance (LO), which allows the compensator (20) to have a reserve of guy length which can be mobilized to allow the second portion (3_2) of the wall containing the second anchor point (M2) to move away from the first portion (3_1) of the wall containing the first anchor point (Ml) when the core (10) is extracted from the cavity (4).,

2. Tooling according to claim 1 characterized in that the stop (21) is adaptive, in that said stop (21) allows a variation in the position of the intermediate passage point (M3) within the groove (12) in reaction to a variation in the intensity of the longitudinal tension which prevails in the stay (5), between the first anchoring point (M1) and the second anchoring point (M2).

3. Tooling according to claim 1 or 2 characterized in that the stop (21) is mounted movably in the groove (12) and is supported by an elastic member (22) so that said stop (21) is capable of ensuring elastic suspension of the stay (5) housed in the groove (12).

4. Tooling according to claim 3 characterized in that, the groove (12) being delimited by two solid side walls (15, 16) which face each other, which intersect the receiving surface (10_out) and which define between them a groove width (W12) which is sufficient to allow the free passage of the transverse section of the stay (5), the stop (21) is formed by a ball (23) whose diameter is strictly greater than the width (W12) of the groove (12) and which is guided in sliding in a chamber (24) communicating with said groove (2) by a slot (25) which allows the stay (5) to engage the stop (21).

5. Tooling according to claim 3 or 4 characterized in that the elastic member 22 is formed by a helical spring (27).

6. Tooling according to one of the preceding claims, characterized in that the intermediate passage point (M3) defined by the stop (21) is located in a zone strictly between the base line (DO) on the one hand and the outline of the receiving surface (10_out) onto which the groove (12) opens on the other hand.

7. Tooling according to claim 6 and one of claims 3 or 4, characterized in that the elastic member (22) is arranged so as to be able to push the stop (21) against the stay (5), in the direction of the receiving surface (10_out).

8. Tooling according to one of the preceding claims, characterized in that the core (10) comprises a plurality of grooves (12) spaced apart from each other and each intended to accommodate a separate stay (5), and in that the compensator (20) comprises a plurality of stops (21), each of said stops (21) being intended for one of said grooves (12).

9. Tooling according to claim 8 characterized in that the compensator (20) comprises a cartridge (30) which is inserted removably into the core (10) in a direction called the “insertion direction”. (D30) which is transverse to the side walls (15, 16) delimiting the different grooves (12), and which comprises a plurality of chambers (24) each containing a stop (21) moved by an elastic member (22), each chamber (24) being provided with a slot (25) which is arranged to align with the corresponding groove (12) of the core (10) in order to allow the stay (5) concerned to reach the stop (21) located in said chamber (24).

10. Tooling according to one of the preceding claims, characterized in that the stay length reserve (Delta_L), equal to the difference between, on the one hand, the length L5_tot of the path followed by the stay (5) in the groove (12), from the first anchoring point (M1) to the second anchoring point (M2) via the intermediate passage point (M3) defined by the stop (21) and, on the other hand, the base distance (LO), is between 3% and 30% of the base distance (LO), and / or between 3 mm, minimum value, and 30 mm, maximum value.

11. Tool (1) according to one of the preceding claims, characterized in that it constitutes a tool intended for the manufacture of a toroidal bandage (40) comprising a crown (41) intended to form a tread, a first annular bead (42) and a second annular bead (43) designed to allow the bandage (40) to be attached to a mounting support such as a rim, as well as a first sidewall (44) and a second sidewall (45) which connect the crown (41) respectively to the first bead (42) and to the second bead (43), the crown (41), the first and second sidewalls (44, 45) and the first and second beads (42, 43) forming as a whole the wall (3) having the concave internal surface (3_in) which delimits the cavity (4) of the bandage (40), in that the receiving surface (10_out) of the core has a toroidal shape which is centered on a central axis (Z 10) and which includes a summit zone (51), radially external,intended to receive components constituting the top (41) of the tire (40), and, on either side axially of said top zone (51), a first lateral zone (52) folded towards the central axis (Z10) and intended to receive components constituting the first sidewall (44) and the first heel (42) as well as a second lateral zone (53) folded towards the central axis (Z10) and intended to receive components constituting the second sidewall (45) and the second heel (43), in that the core (10) comprises a plurality of grooves (12) which are distributed in azimuth around the central axis (Z10) and arranged to allow the passage, through the cavity, of stays (5) which connect, each a first anchoring point (Ml), called "summit anchoring point", located in the top (41) of the bandage, to a second anchoring point M2, called "lateral anchoring point", located in one of the sides (44, 45) or the heels (42, 43) of the bandage (40), and in that the compensator (20) associates with each groove (12) of the plurality of grooves (12) a stop (21), preferably suspended by an elastic member (22), in order to create a reserve of stay length in said groove (12).

12. A method of manufacturing an object during which a tool (1) according to any one of the preceding claims is used, a stay (5) is placed in each groove (12) of the core (10), against the stop (21), then at least one component is placed on the receiving surface (10_out) to form the wall (3), then the object (2) is demolded by separating from each other a first portion of the wall (3_1) containing a first anchoring point (M1) of the stay (5) and a second portion of the wall (3_2) containing a second anchoring point (M2) of the stay (5), to allow the extraction of the core (10) from the cavity (4) delimited by the wall (3).

13. Method according to claim 12 characterized in that the manufactured object (2) is a tire (40) whose wall (3) is formed from one or more rubber-based components, and in that, for this purpose, the stays (5) are placed on the core (10), in the grooves (12), said rubber-based component(s), intended to form the wall (3), are placed in the raw state on the receiving surface (10_out) of the core, then the core (10) furnished with the stays (5) and the wall (3) is subjected to a curing operation making it possible to vulcanize the rubber-based component(s) of the wall, then the tire (40) is demolded by separating, by elastic deformation, the second portion of the wall (3_2) from the first portion of the wall (3_1) and by extracting the core (10) from the cavity (4) delimited by said wall (3).

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