METHOD FOR MACHINING THE OUTER LAYER OF A TIRE DURING WHICH THE CUTTING PATH IS ADAPTED ACCORDING TO THE ORIENTATION OF THE REINFORCING THREADS WHICH ARE LOCATED UNDER SAID OUTER LAYER

Abstract

The present invention relates to a method for machining a tire (1) whose wall (3) comprises an outer layer (4) based on elastomer and a reinforcing ply (5) containing reinforcing threads (6), during which the tire (1) is rotated (R20) in a chosen direction of rotation (R20+, R20-), and a cutting path (T2_1, T2_2) is executed with a cutting tool (2) over a given cutting range (W2_1, W2_2) and in a given axial direction of travel (S2_1, S2_2) to remove material from the outer layer (4), said method comprising an analysis step during which the orientation (A6) of the reinforcing threads (6) is identified, then an adaptation step during which, as a function of the orientation (A6) of the reinforcing threads, the direction of rotation (R20+, R20-) of the tire, as well as the range cutting direction (W2_1, W2_2) and the axial direction of travel (S2_1, S2_2) applicable, so as not to take the ends of the reinforcement threads (6) against the grain.Figure 6A.

Description

Title of the invention: METHOD FOR MACHINING THE OUTER LAYER OF A TIRE DURING WHICH THE CUTTING PATH IS ADAPTED ACCORDING TO THE ORIENTATION OF THE REINFORCING THREADS WHICH ARE LOCATED UNDER SAID OUTER LAYER

[0001] The present invention relates to the field of machining of tires, in particular rubber-based pneumatic tires, said machining having the aim of removing from the tire at least part of the material which constitutes it, for example with a view to retreading said tire and / or recycling said material when said tire reaches the end of its life.

[0002] More particularly, with a view to increasing the recycling rate of the raw materials which make up the bandages, the inventors wished to develop a machining process which makes it possible to recover, from a bandage which is definitively reaching the end of its life and whose carcass can therefore no longer be repaired or reused, the largest possible quantity of rubber-based material constituting the external layer covering the carcass, and in particular the largest possible quantity of the material constituting the tread.

[0003] This, however, presents several difficulties.

[0004] A first difficulty is to carry out material removal which is rapid, in order to limit the cycle time and the energy consumption which are necessary to carry out the machining operation.

[0005] A second difficulty is that, although one seeks to recover a maximum amount of material, which encourages machining the outer layer as deeply as possible, as close as possible to the reinforcing threads belonging to the carcass of the tire, it is also appropriate, on the one hand, for the machining process to remain selective, so that only the desired rubber-based material of good quality is removed from the tire during the machining operation, without mixing foreign bodies, such as fragments of reinforcing threads from the carcass, with said material, and, on the other hand and above all, to prevent the cutting tool from catching, cutting or tearing the reinforcing threads present in the carcass, in particular when it comes to metal reinforcing threads, which are particularly likely to blunt the cutting tool and / or block the machining operation by becoming entangled.

[0006] The objects assigned to the invention therefore aim to remedy the aforementioned drawbacks and to propose a machining method which makes it possible to recover in a quickly and safely a maximum of good quality rubber-based material on a used bandage, while preserving the cutting tool as much as possible, and which allows in particular for this purpose to remove material as close as possible to the carcass of the bandage without risking harmful interference with the reinforcing threads of said carcass.

[0007] The objects assigned to the invention are achieved by means of a method of machining a bandage, said bandage having a wall which comprises at least one outer layer based on elastomer and at least one reinforcing ply which is located under said outer layer and which contains a plurality of reinforcing threads arranged according to an implantation pattern specific to the bandage, said method comprising a material removal step during which at least one cutting sequence is carried out according to which: - by means of a rotating support having an axis of rotation called the “main axis”, the bandage is driven in rotation on itself, around said main axis, in a chosen direction of rotation, - and, while the bandage is rotated on itself, a cutting path is executed with a cutting tool which allows the cutting tool to remove material from the outer layer as said cutting tool progresses along said cutting path, said method being characterized in that it comprises, prior to the material removal step: - a step of analyzing the bandage during which at least part of the layout diagram according to which the reinforcing wires of the reinforcing ply are arranged within the bandage to be machined is identified, - then a step of adapting the cutting sequence during which the cutting sequence is defined by adapting said cutting sequence according to at least one part of the implantation diagram which was identified during the bandage analysis step.

[0008] Advantageously, the method according to the invention makes it possible to make the cutting conditions used to remove the material constituting the external layer depend on the actual pattern of implantation of the reinforcing wires, and more particularly on the orientation that the reinforcing wires have when said reinforcing wires are arranged obliquely relative to the circumferential direction of the bandage, and in particular the direction of rotation of the bandage, the axial range of the bandage in which the cutting is carried out, and the direction of axial travel in which the cutting tool moves within said axial range, along the main axis.

[0009] Thus, said cutting conditions can be adapted so that the relative movement of the cutting tool with respect to the bandage, relative movement which includes at least one circumferential component, called “cutting speed”, carried by the circumferential direction differential of the bandage and which results from the rotation of the bandage, and an axial component called "feed rate" corresponding to the axial displacement component of the cutting tool along the main axis, tends to slide the cutting tool in the direction of the path of the reinforcing wires, during the machining operation, so that the cutting tool tends to press said reinforcing wires against the carcass, without taking said wires against the grain.

[0010] This considerably limits the risk of the cutting tool accidentally catching, lifting, or tearing the reinforcing threads, including in particular when the cutting tool reaches an axial end of the reinforcing ply, at which the reinforcing threads have a free end, and therefore form, relative to the circumferential direction of the bandage, points potentially vulnerable to peeling.

[0011] Furthermore, by taking note of the layout diagram of the reinforcing wires and thus adapting the cutting sequence on a case-by-case basis to the actual structure of the bandage which is subjected to the machining operation, it is possible to determine for each bandage a personalized cutting sequence, which is optimized to pass, without risk of snagging, the cutting tool as close as possible to the reinforcing wires, and therefore to remove and recover the maximum amount of material constituting the external layer, whatever the structure of the bandage and therefore whatever the layout diagram of the reinforcing wires.

[0012] The method according to the invention is therefore versatile, effective and safe, in particular for recycling the constituent materials of used tire treads.

[0013] 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:

[0014] [Fig.l] illustrates, in a perspective view, an example of an installation making it possible to implement a method according to the invention, here more particularly an installation comprising two robotic arms respectively carrying a first cutting tool and a second cutting tool arranged on either side of the rotating support which carries the bandage to be machined.

[0015] [Fig.2] is a front view of the installation of [Fig.l], in a plane normal to the main axis.

[0016] [Fig. 3] illustrates, according to a schematic cutaway perspective view, a possible first layout diagram of a bandage which can be treated by the method according to the invention, said first layout diagram comprising in this case a first reinforcing ply, radially the outermost, which has a first set of reinforcing threads arranged parallel to each other, according to a first oblique orientation relative to the equatorial circumferential direction of the bandage, and a second reinforcing ply, radially more internal than the first reinforcing ply, which is partially covered by the first reinforcing ply and which extends axially beyond the axial limits of the first reinforcing ply, and which comprises a second set of reinforcing threads, arranged parallel to each other, and having a second oblique orientation of the same sign as the first orientation of the reinforcing threads of the first reinforcing ply.

[0017] [Fig.4] is a sectional view, in a radial plane containing the main axis, and before any material removal operation, of a bandage which has a first implantation diagram according to [Fig.3].

[0018] Figures 5A and 5B illustrate, according to schematic views respectively in perspective and in section in a radial plane, the bandage of [Fig.4] during a step of analysis of the bandage according to the invention, during which a circumferential trench is dug in the equatorial region of the bandage, so as to reveal the first reinforcing ply at the bottom of said trench, and the corresponding implantation diagram is thus identified, here the first implantation diagram, and more particularly the orientation of the reinforcing threads of the first reinforcing ply is identified.

[0019] Figures 6A, 6B and 6C illustrate, respectively in a partial schematic view from above, a perspective view, and a schematic view in section in a radial plane, the bandage of Figures 4 and 5A and 5B, after a first cutting sequence during which the bandage has been rotated in a first direction of rotation and the outer layer removed by axially moving a cutting tool, flush with the first reinforcing ply then the second reinforcing ply, from the equatorial trench towards a first axial end of the bandage, over a first axial cutting range which covers a first hemisphere of the bandage.

[0020] Figures 7A and 7B illustrate, respectively in a partial schematic view from above and a schematic view in section in a radial plane, the bandage of Figures 4 and 5A and 5B, after a second cutting sequence which followed the first cutting sequence of Figures 6A, 6B and 6C, and during which the outer layer was removed by rotating the bandage in a second direction of rotation, opposite to the first direction of rotation, and by axially moving a second cutting tool, distinct from the first cutting tool used for the first cutting sequence, flush with the first reinforcing ply then the second reinforcing ply, from the equatorial trench towards the second axial end of the bandage, over a second axial cutting range which covers the second hemisphere of the bandage.

[0021] Figures 8A and 8B illustrate, respectively in a partial schematic view from above and a schematic view in section in a radial plane, the bandage of Figures 4 and 5A and 5B, after a variant of the second cutting sequence, which was preferably carried out simultaneously with the first cutting sequence of Figures 6A, 6B and 6C. During this variant of the second cutting sequence, the outer layer is removed in the second hemisphere of the bandage, by maintaining a first direction of rotation of the bandage identical to that implemented for the first cutting sequence used to remove the outer layer in the first hemisphere of the bandage, and by axially moving a second cutting tool, distinct from the first cutting tool used for the first cutting sequence, in the axial range corresponding to said second hemisphere, towards the second axial end of the bandage, but by maintaining said second cutting tool at a radial distance from the main axis which is strictly greater than that used for the first cutting tool in the first hemisphere of the bandage, and this in order to maintain in the second hemisphere, for safety, a residual thickness of outer layer which protects the reinforcing threads from tearing.

[0022] [Fig. 9] illustrates, in a perspective cutaway view, including an enlarged inset portion, a possible second layout diagram for a tire that can be treated by the method according to the invention. Said second layout diagram comprises in this case a first radially external reinforcing ply which has a first set of reinforcing threads which are arranged parallel to each other, and substantially or even exactly parallel to the equatorial circumferential direction of the tire. This first reinforcing ply, also called a "fret", thus forms a hoop which preferably covers the entire axial width of the top of the tire. Such a first reinforcing ply can in particular be obtained by winding around the main axis, on several consecutive contiguous turns, a continuous strip formed from a rubber matrix in which parallel and continuous reinforcing threads are embedded.The second layout scheme further provides a second reinforcing ply, which is located under the first reinforcing ply and which comprises a second set of reinforcing threads, preferably arranged obliquely relative to the equatorial circumferential direction, and the axial ends of which are located set back from the corresponding axial ends of the first reinforcing ply, so that the first reinforcing ply extends axially beyond the second reinforcing ply and completely covers said second reinforcing ply.

[0023] [Fig. 10] is a sectional view, in a radial plane containing the main axis, and before any material removal operation, of a bandage which has a second layout diagram according to [Fig.9].

[0024] Figures 11A and 11B illustrate, respectively in a partial schematic view from above and a schematic view in section in a radial plane, the bandage of [Fig. 10] during a step of analysis of the bandage according to the invention, during which a circumferential trench is dug in the equatorial region of the bandage, so as to reveal the first reinforcing ply at the bottom of said trench, and the corresponding implantation diagram is thus identified, here the second implantation diagram, and more particularly the orientation of the reinforcing threads of the first reinforcement layer.

[0025] Figures 12A and 12B illustrate, respectively in a partial schematic view from above and a schematic view in section in a radial plane, the bandage of Figures 10 and 11A and 11B after the execution of a first cutting sequence during which the outer layer in the first hemisphere of the bandage has been removed, by means of a first cutting tool which has been advanced axially in contact with the first reinforcing ply, from the equatorial trench to the first axial end of the bandage, and the execution of a second cutting sequence during which the outer layer in the second hemisphere of the bandage has been removed, by means of a second cutting tool which has been advanced axially in contact with the first reinforcing ply, from the equatorial trench to the second axial end of the bandage.

[0026] [Fig. 13] illustrates, in a detailed perspective view, the end of a robotic arm of the installation of figures 1 and 2 which carries a cutting tool formed by a rotating cylindrical knife as well as the sharpening system for maintaining the circular cutting edge of said knife.

[0027] [Fig. 14] illustrates, in a schematic top view, a possible third layout diagram which, like the first layout diagram of [Fig.3], comprises a first reinforcing ply, radially the outermost, which has a first set of reinforcing threads arranged parallel to each other, according to a first oblique orientation relative to the equatorial circumferential direction of the tire, and a second reinforcing ply, radially more internal than the first reinforcing ply, which is partially covered by the first reinforcing ply and which extends axially beyond the axial limits of the first reinforcing ply, and which comprises a second set of reinforcing threads, arranged parallel to each other, and having a second oblique orientation, but within which, unlike the first layout diagram, the second orientation according to which the second reinforcing threads are arranged within the second reinforcing ply is this time of opposite sign to the sign of the first orientation according to which the first reinforcing threads of the first reinforcing ply are arranged.

[0028] [Fig. 15] illustrates, according to a schematic view in a radial plane, a bandage arranged according to the third layout diagram illustrated in [Fig. 14], after the execution of a first cutting sequence during which a first so-called "straight" cutting path has been implemented, which cutting path is rectilinear and parallel to the main axis, to remove the external layer in the first hemisphere of the bandage, and the execution of a second cutting sequence during which a second straight cutting path has been implemented, rectilinear and parallel to the main axis, and here located at the same constant radial distance from the axis main than the first cutting path. Advantageously, the choice of such straight cutting paths makes it possible to carry out the removal of material in contact with the first reinforcing ply, radially the outermost, initially, then to continue the removal of material in line with the second reinforcing ply by holding the cutting tool slightly radially back from said second reinforcing ply. Thus, the cutting conditions can be adapted to the orientation of the first reinforcing wires which belong to the first reinforcing ply so that the cutting tool can, initially, slide in the correct direction in contact with said first reinforcing wires, without catching said first reinforcing wires, in the equatorial zone then when said tool crosses the end of said first reinforcing wires at the lateral edge of the first reinforcing ply in the hemisphere in question.Because the second reinforcing ply is located in a slight centripetal radial recess relative to the first reinforcing ply, these same cutting conditions then allow the cutting tool, when it continues its rectilinear axial movement in the hemisphere considered, while the bandage remains rotating in the same direction, to remain at a radial distance from the second reinforcing ply, leaving a slight residual thickness of external layer between the cutting tool and said second reinforcing ply for safety, so that the cutting tool does not risk catching the second reinforcing wires, although said second reinforcing wires have an orientation which is of the opposite sign to the orientation of the first reinforcing wires.Thus, in particular, the cutting tool can cross the lateral edge of the second reinforcing ply without damage, although, at the level of this lateral edge, said cutting tool flies against the grain over the ends of said second reinforcing threads.

[0029] [Fig. 16] illustrates, according to a schematic view in a radial plane, the principle according to which, to ensure that the cutting tool comes into contact with the reinforcing ply and then slides along the reinforcing ply while remaining in contact with the reinforcing wires, and this in order to remove as much thickness as possible from the external layer, said cutting tool is brought to a starting position, here in the equatorial plane, which is radially closer to the main axis, by a value called the "nominal deflection value", than is the reinforcing ply, the outermost face of which is located, in the absence of a cutting tool, at a radial distance from the main axis called the "radial envelope distance". Thus, the cutting tool is advantageously prestressed against the reinforcing ply, locally creating a slight centripetal radial deformation of the reinforcing wires by elastic bending.

[0030] The present invention relates to a method of machining a bandage 1.

[0031] Machining allows the mechanical removal of material from the bandage 1, by means of a cutting tool 2, 2'.

[0032] It should be noted that, in absolute terms, it could be considered to use as a cutting tool 2, 2' an abrasive tool, of the grinding wheel type. However, preference will be given to a cutting tool 2, 2' having at least one sharp blade, for example a cutting tool formed by a cylindrical knife 25, 25' as will be seen below. Such a cutting tool 2, 2' having a sharp blade in fact provides in particular a faster and more efficient cut than a grinding wheel, for less energy expenditure.

[0033] The machining method according to the invention may be used, for example, for stripping a bandage 1, i.e. for removing the remains of a worn tread from the bandage, with a view to retreading said bandage, when the carcass of said bandage 1 is reusable.

[0034] However, preferably, the machining method according to the invention will be part of a method for recycling a rubber-based material present on the bandage 1, preferably a method for recycling the rubber-based material constituting the tread, and will therefore aim to recover the largest possible quantity of said material relative to the total quantity of said material which is present on said bandage 1.

[0035] Such a recycling process will find application in particular to end-of-life tires 1, the carcass of which can no longer be repaired or reused, and which must therefore be dismantled to recover the raw materials.

[0036] As can be seen in particular in Figures 4 and 10, the bandage 1 has a wall 3 which comprises at least one external layer 4 based on elastomer, preferably based on vulcanized rubber, and at least one reinforcing ply 5, 5' which is located under said external layer 4 and which contains a plurality of reinforcing threads 6, 6'.

[0037] E4 will denote the thickness of the external layer 4, and in particular the residual thickness of said external layer, which separates the external surface of the wall 3 from the surface of the reinforcing ply 5, 5' closest to said external surface of the wall 3.

[0038] In a manner known per se, the reinforcing ply 5, 5' is preferably formed by a thin layer of a material forming a matrix which extends in two main directions which define the surface of the reinforcing ply, and in the thickness of which the reinforcing threads 6, 6' are embedded.

[0039] In particular, it will be possible to have a reinforcing sheet 5, 5' whose matrix is formed from an elastomer base, preferably from rubber, and containing metallic reinforcing threads 6, or possibly from a polymer such as Taramide.

[0040] Alternatively, the reinforcing sheet 5, 5' may have a resin matrix reinforced by reinforcing threads 6, 6' made of fiberglass.

[0041] Within the same reinforcing ply 5, 5', the reinforcing threads 6, 6' will preferably be arranged side by side, parallel to each other, even if other arrangements are possible without departing from the scope of the invention.

[0042] Said reinforcing wires 6, 6' are arranged according to an implantation diagram, which is specific to bandage 1.

[0043] The layout diagram defines the layout of the reinforcing threads 6, 6' within the reinforcing ply 5, 5', and therefore in particular the orientation A6, A6' of said reinforcing threads 6, 6', or even the spacing between neighboring reinforcing threads 6, 6'.

[0044] More particularly, the layout diagram will define the layout of the reinforcing wires 6, 6' which are located immediately under the outer layer 4 that it is desired to machine, and which are therefore closest to the apparent surface of the outer layer 4 into which the cutting tool 2 will penetrate. Said reinforcing wires 6, 6' therefore mark the maximum depth limit that one is, materially, authorized to reach with the cutting tool 2 when digging the outer layer 4 with the intention of selectively recovering the material constituting said outer layer 4 without perforating the reinforcing ply 5, 5' and without peeling, tearing or cutting said reinforcing wires 6, 6'.

[0045] Where appropriate, said reinforcing threads 6, 6' may be distributed over several reinforcing plies 5, 5', in particular within a first reinforcing ply 5 and a second reinforcing ply 5', which partially overlap and thus each have at least one surface portion located immediately under the external layer 4, in contact with said external layer, as is for example the case in FIGS. 3, 4, 14 and 15.

[0046] The implantation diagram will then define the number and the respective arrangement of the various reinforcement plies 5, 5' which are part of the composition of the bandage 1.

[0047] The implantation diagram is specific to the bandage, in that said implantation diagram will vary in particular depending on the model of the bandage 1, the dimensions of the bandage, and the intended use of the bandage 1, depending for example on whether the bandage 1 is intended to be used on a passenger vehicle, on a racing car, on a heavy goods vehicle, on construction machinery, on agricultural machinery, etc.

[0048] By way of example, a first layout diagram may be considered, as illustrated in Figures 3, 4 and 7A, which in this case comprises a first reinforcing ply 5, radially the outermost, which has a first set of reinforcing threads 6, called “first reinforcing threads 6”, arranged parallel to each other, according to a first orientation A6 oblique relative to the equatorial circumferential direction of the tire 1, and a second reinforcing ply 5', radially more internal than the first reinforcing ply 5, which is partially covered by the first reinforcing ply 5 and which extends axially beyond the axial limits of the first reinforcing ply, and which comprises a second set of reinforcing threads 6', called “second reinforcing threads 6'”, arranged parallel to each other, and having a second oblique orientation A6' of the same sign as the first orientation A6 of the reinforcing threads 6 of the first reinforcing ply reinforcement 5.

[0049] Such a first implementation plan may in particular be found frequently within a bandage 1 intended for heavy goods vehicles.

[0050] The first reinforcing wires 6 of the first reinforcing ply 5 implemented in accordance with this first implantation scheme will preferably be metallic. Similarly, the second reinforcing wires 6' of the second reinforcing ply 5' implemented in accordance with this first implantation scheme will preferably be metallic.

[0051] According to another example, a second layout diagram may be considered as illustrated in Figures 9 and 10, which comprises a first radially external reinforcing ply 5 which has a first set of reinforcing threads 6 which are arranged parallel to each other, and substantially or even exactly parallel to the equatorial circumferential direction of the bandage. This first reinforcing ply, also called "fret", thus forms a strapping which preferably covers the entire axial width of the top of the bandage. Such a first reinforcing ply 5 may in particular be obtained by winding on several consecutive contiguous turns around the central axis of the bandage, a continuous strip formed of a rubber matrix in which parallel and continuous reinforcing threads 6 are embedded.This second implantation scheme further provides a second reinforcing ply 5', which is located under the first reinforcing ply 5 and which comprises a second set of reinforcing threads 6', preferably arranged obliquely relative to the equatorial circumferential direction, and the axial ends of which are located set back from the corresponding axial ends of the first reinforcing ply 5, so that the first reinforcing ply 5 extends axially beyond the second reinforcing ply 5' and completely covers said second reinforcing ply 5'.

[0052] The first reinforcing threads 6 used in the first reinforcing ply 5 according to this second implantation scheme, radially the outermost, may be made of a metallic material, for example steel, in a composite material comprising glass fibers embedded in a resin, or even in a textile polymer material such as polyamide (“Nylon”) or aramid.

[0053] The second implantation scheme described above may in particular, but not exclusively, be implemented within tires intended to equip passenger vehicles.

[0054] A possible third layout diagram is illustrated in [Fig. 14]. This third layout diagram takes up the characteristics of the first layout diagram described above with reference to Figures 3, 4 and 7A, with the exception of the fact that, according to said third layout diagram, the orientation A6' of the second reinforcing threads 6' present in the second reinforcing ply 5' is of opposite sign to the orientation A6 of the first reinforcing threads 6 present in the first radially outermost reinforcing ply 5, and no longer of the same sign as said orientation A6 of the first reinforcing threads 6.

[0055] For convenience of description, when it is not necessary to distinguish specifically between the first reinforcing ply 5 and the second reinforcing ply 5', respectively between the first reinforcing threads 6 and the second reinforcing threads 6', and in particular when characteristics can be applied indifferently to a bandage 1 in which a single reinforcing ply would be concerned by the machining operation or to a bandage in which several reinforcing plies would be concerned by the machining operation, reference may be made generically to a "reinforcing ply 5, 5'" or to a "reinforcing ply 5", and respectively to "reinforcing threads 6, 6'" or "reinforcing threads 6".

[0056] Furthermore, it will be noted that the invention is applicable to very varied types of bandages, including toroidal bandages intended to equip vehicle wheels, among which pneumatic bandages, or airless bandages suspended by flexible spokes, but also bandages forming tracks intended for example for construction machinery, agricultural machinery or snowmobiles, or even bandages forming reinforced belts such as transmission belts or conveyor belts. The support 20 intended to receive the bandage 1 for the machining operations may of course be adapted according to the nature of the bandage 1 to be treated.

[0057] Preferably, the method may be applied to tires 1 intended for heavy goods vehicles, typically vehicles whose total authorized laden weight is greater than 3.5 tonnes, said tires being sized to be mounted on rims with dimensions between 16.5 inches and 24 inches.

[0058] The method may however also be applied to tires 1 intended for passenger vehicles, and therefore adapted to rims with a diameter between 13 inches and 24 inches.

[0059] The method according to the invention can of course be applied without restriction to tires of very varied dimensions, including very large tires, for example civil engineering tires intended to be mounted on rims of up to 63 inches.

[0060] Preferably, in a manner known per se, and as can be seen in Figures 1, 2, 4, 10 and 15, the bandage 1 has a first annular heel 7 and a second annular heel 8, provided respectively with a first bead wire and a second bead wire (not shown), and the wall 3 of the bandage forms a crown 10, radially external, as well as a first flank 11 which connects said crown 10 to the first heel 7 and a second flank 12 which connects the crown 10 to the second heel 8.

[0061] In a manner known per se, the first and second beads 7, 8 allow the mounting of the bandage on a rim.

[0062] The outer layer 4 will preferably correspond to the tread of the bandage 1, which extends over the top 10 of said bandage 1.

[0063] The method according to the invention comprises a material removal step during which at least one cutting sequence is carried out according to which: - by means of a rotating support 20 having an axis of rotation called the “main axis” Z20, the bandage 1 is driven in rotation R20 on itself, around said main axis Z20, in a chosen direction of rotation R20+, R20-, - and, while the bandage 1 is driven in rotation R20 on itself, a cutting path T2_l, T2_2 is executed with a cutting tool 2, 2', shown in dotted lines in figures 6A, 6C, 7A, 7B, 8A, 8B, 12A, 12B, and 15, which allows the cutting tool 2, 2' to remove material from the outer layer 4 of the bandage 1 as said cutting tool 2, 2' progresses along said cutting path T2_l, T2_2.

[0064] In practice, the main axis Z20 will coincide with the central axis of the bandage 1, around which the bandage 1 forms a toroidal ring, and which therefore corresponds to the axis around which the bandage rotates when said bandage 1 is in service on a vehicle wheel and rolling on the ground.

[0065] By convention, “axial” will designate a direction parallel to the axis considered, here more particularly a direction parallel to the axis of rotation Z20, and “radial” a direction perpendicular to said axis.

[0066] The term “circumferential” direction will be used to designate a direction of the tire which is orthoradial relative to the central axis of the tire, here therefore orthoradial relative to the main axis Z20, that is to say a direction which is contained in a plane normal to the central axis of the tire and which is, at a point considered on the tire, perpendicular to the radius which joins the central axis of the tire to said point considered, or even, in other words, a direction which, at a point considered on the tire, is normal to the radial plane which contains the central axis of the tire and which passes through said point considered.

[0067] By analogy with the terrestrial globe, the term "equatorial plane" P_EQ will conventionally designate the plane normal to the central axis of the bandage, here therefore normal to the main axis Z20, which passes through the middle of the axial range W1 occupied by the bandage 1, and which thus divides said bandage into a first hemisphere H1 and a second hemisphere H2, said second hemisphere H2 being located opposite the first hemisphere H1 with respect to said equatorial plane P_EQ.

[0068] The axial width W1 of the bandage corresponds to the distance which separates two fictitious gauge planes which are normal to the central axis of the bandage, here the main axis Z20, and which are each tangent to the wall 3, respectively at a first axially outermost point of the wall 3, generally located at the outer surface of the first flank 11, and forming a first axial end 1_1 of the bandage, and at a second axially outermost point of the wall 3, located axially opposite the first point, and generally located on the surface of the second sidewall 12, and forming a second axial end 1_2 of the bandage 1.

[0069] Similarly, the term "radial plane" or "meridian plane" will designate a plane which contains the central axis of the tire, here therefore which contains the main axis Z20, and which therefore extends on the one hand along the central axis of the tire, and on the other hand along a radius of the tire, perpendicular to the central axis.

[0070] Preferably, the rotating support 20 is arranged to hold the bandage 1, preferably not inflated, by the first heel 7 and second heel 8, while leaving the top 10 free.

[0071] The inventors have in fact found that it is thus possible to hold the bandage 1 by the heels 7, 8, while maintaining sufficient firmness of said bandage 1 for the machining operation, without it being necessary to inflate said bandage 1 or to support said bandage 1 by tiles which would be placed under the top 10 of said bandage 1.

[0072] It is therefore advantageous to machine bandages 1 which are no longer watertight, because they have perforations or lacerations, which is common on bandages which have reached the end of their life.

[0073] Preferably, the method, and more particularly the material removal step, will therefore be implemented on a non-inflated tire 1, that is to say a tire 1 whose radially internal face of the wall 3 is at ambient atmospheric pressure, without overpressure relative to said ambient atmospheric pressure which bathes the support 20 and more generally the workshop in which the installation 40 which makes it possible to carry out the method is installed.

[0074] Furthermore, the support by the heels 7, 8 allows the same support 20 to easily adapt to bandages 1 of very varied dimensions, and in particular to bandages 1 having internal diameters which are very different from one bandage 1 to another.

[0075] In this respect, it will be noted that, as illustrated in Figures 1 and 2, the rotary drive support 20 may for example be formed by a radially expandable drum 21, having jaws 22 which are capable of alternately deploying in a radially centrifugal manner to engage the heels 7, 8, thus adopting a diameter corresponding to the internal diameter of the bandage 1, and retracting in a radially centripetal manner to release the bandage 1 after the machining operation.

[0076] As an indication, the rotation speed of the support 20, and therefore of the bandage 1, during the material removal operations may be between 1 rpm and 5 rpm, for example equal to 3 rpm. Higher rotation speeds could of course be considered, for example of the order of 10 rpm. The aforementioned speeds, however, represent an advantageous compromise between the power required for the acceleration and braking of the support 20, reliability of the analysis step of the bandage, and cycle time.

[0077] During the cutting sequence, a cutting path T2_l, T2_2 is preferably executed with the cutting tool 2, 2', while the bandage is driven in rotation R20 on itself in the desired direction of rotation R20+, R20-, according to which said cutting tool 2 is made to travel, opposite the bandage 1, a predetermined axial range W2_l, W2_2 considered along the main axis Z20, called "axial cutting range", W2_l, W2_2, in a direction called "axial travel direction" S2_l, S2_2 predetermined, so that said cutting tool 2, 2' removes material from said outer layer 4 in said axial cutting range W2_l, W2_2 as said cutting tool 2, 2' progresses along the main axis Z20 in the axial travel direction S2_l, S2_2.

[0078] For example, the axial cutting range W2_l corresponds to the first hemisphere H1 in Figures 6A, 6B and 6C, and the axial cutting range W2_2 corresponds to the second hemisphere H2 in Figures 7A and 7B.

[0079] The axial travel direction S2_l, S2_2, corresponds to the direction in which the cutting tool 2, 2' generally travels the axial range W2_l, W2_2 during the cutting sequence, on the abscissa along the main axis Z20, and therefore moves across the width of the bandage, transversely to the circumferential direction of the bandage 1, starting from a starting axial abscissa, which corresponds to the end of the axial cutting range where the cutting sequence begins, to arrive at an ending axial abscissa, which corresponds to the other end of the axial cutting range, where the cutting sequence ends.

[0080] By convention, it may be considered that the axial travel direction is positive, and therefore that the cutting tool moves along the increasing abscissas along the main axis Z20, when the cutting tool moves from the second flank 12 to the first flank 11, which corresponds to a direction of movement from the background to the foreground in FIGS. 1 and 2. For convenience, the positive direction of the increasing abscissas of the main axis Z20 may be noted Z20+.

[0081] By way of example, the axial direction of travel S2_l goes from left to right in FIGS. 6A, 6C, here from the equatorial plane P_EQ to the first flank 11, and therefore in the positive direction Z20+, while the axial direction of travel S2_2 goes from right to left in FIGS. 7A, 7B, here from the equatorial plane P_EQ to the second flank 12, and therefore in the negative direction, noted Z20-.

[0082] The direction of rotation R20- is by convention negative in figures 6A, 6B and 8A, that is to say corresponds to a clockwise direction in figures 1 and 2, and is therefore oriented from bottom to top in said figures 6A and 8A.

[0083] Conversely, the direction of rotation R20+ is conventionally positive in Figure 7A, which corresponds to a counterclockwise direction of rotation, or “trigonometric direction”, on the Figures 1 and 2.

[0084] Furthermore, when it is sought to remove as much material as possible from the outer layer 4, as is the case in the context of a recycling process, the cutting sequence preferably provides that the cutting path T2_l, T2_2 is such that, in at least a part, or even in all, of the outer layer 4 crossed by said cutting path T2_l, T2_2, the residual thickness E4 of outer layer 4 that the cutting tool 2 which executes said cutting path T2_l, T2_2 leaves, at most, on the reinforcing wires 6, is less than or equal to 2 mm, preferably less than or equal to 1 mm, or even zero.

[0085] Indeed, the cutting tool 2 will pass as close as possible to the reinforcing wires 6 of the reinforcing ply 5 which is immediately underlying the external layer 4, and will therefore leave at most a residual thickness E4 of said external layer 4 which will be thin, or even zero.

[0086] An example of an application where the cutting tool 2, 2' leaves a very thin but non-zero residual thickness E4 is illustrated in the case of the removal of material carried out in the second hemisphere H2 (here on the left) in figure 8B.

[0087] Another example of application where the cutting tool 2, 2' this time leaves no residual thickness E4, i.e. a zero residual thickness E4, is illustrated in the case of the removal of material carried out in the first hemisphere H1 in FIGS. 6C and 8B (here on the right in said figures) or in each of the first and second hemispheres H1, H2 in FIGS. 12A and 12B.

[0088] It will be noted that, for this purpose, according to a preferred implementation possibility, the cutting trajectory T2_l, T2_2 is such that the cutting tool 2 slides on the reinforcing ply 5, in contact with the reinforcing wires 6, over at least a part, or even over the entirety, of the cutting range W2_l, W2_2 assigned to it.

[0089] It is thus possible to remove, by carriage, that is to say by axial movement of the cutting tool 2, in contact with the reinforcing ply 5, the entire thickness of the external layer 4, and thus obtain a zero residual thickness E4, and this without cutting or tearing the reinforcing wires 6, nor a fortiori perforating the reinforcing ply 5, during the passage of the cutting tool 2.

[0090] To ensure that the cutting tool 2, 2' remains in contact with the reinforcing ply 5, 5' over the entire circumference of the bandage 1, at each instant of rotation of the bandage 1, and that said cutting tool 2, 2' therefore slides well along the reinforcing threads 6, 6', without losing contact with the latter, including when the bandage 1, and more particularly the reinforcing ply 5, 5', has a slight centering defect on the main axis Z20 and / or slight shape defects of the "out-of-round" type which result, on the circumference of the bandage 1, in slight local variations in the radius of the wall 3, it will be possible advantageously, according to a preferential characteristic which may constitute an invention in its own right, and as will be explained in more detail in the following, provide a cutting path T2_l, T2_2 which positions and axially moves the cutting tool 2, 2' at a radial distance from the main axis Z20 which is strictly less than the radial distance called the "radial envelope distance" D0_ply at which, in the absence of radial stress exerted on the wall 3 by the cutting tool 2, 2', the radially external limit of the reinforcing wires 6, 6' of the reinforcing ply 5, 5' which is located immediately under the external layer 4 is located. Thanks to such positioning, the cutting tool 2, 2' will force the reinforcing wires 6, 6' to flex elastically to form a slight centripetal radial depression of the reinforcing ply 5, 5', and will therefore be prestressed against the reinforcing ply 5, 5' by centripetal radial prestressing, which will make it possible to compensate for any radial play and therefore in particular to compensate for out-of-roundness..

[0091] It will be noted that the aforementioned cutting sequence, according to which the cutting tool 2 passes less than 2 mm, or even less than 1 mm from the reinforcing wires 6, or even slides in contact with said reinforcing wires 6, may correspond: - or, preferably, according to a so-called “single-pass” operating mode, with a single cutting sequence, according to which all of the material constituting the external layer 4 is removed, which is thus considered recoverable in the axial cutting range W2_l, W2_2 considered in a single turning pass carried out in said axial cutting range as close as possible to the reinforcing wires 6, - or, possibly, according to a so-called “multi-pass” operating mode, at the last cutting sequence of a series of cutting sequences which take place in the axial cutting range W2_l, W2_2 concerned, that is to say at the last pass of a succession of turning passes during which the cutting tool 2 will have been progressively brought radially closer to the reinforcing wires 6, step by step, by pushing the cutting tool 2 a little further into the external layer 4 with each pass, in the direction of the reinforcing ply 5, in stages corresponding to the desired depth of pass.

[0092] The “single-pass” operating mode will be preferred as much as possible in order to minimize the cycle time. However, a “multi-pass” operating mode may be opted for, and in particular for an operating mode with two successive passes, in certain situations, and in particular when a large thickness of external layer 4 is still present on the bandage 1, which large thickness could affect the identification of the bandage implantation pattern, or even exceed the cutting power capabilities of the machine and cause the machine to stall.

[0093] Of course, as indicated above, the invention aims to ensure that, when the cutting tool 2 is made to penetrate the external layer 4 and when the the removal of material from the outer layer 4, and although the cutting tool 2 is brought close to the reinforcing wires 6, or even into contact with said reinforcing wires, where appropriate by exerting a radial prestressing of the cutting tool 2 against the reinforcing wires 6 to the point of creating a local depression of the reinforcing wires 6 and the corresponding reinforcing ply 5, any damaging interference of said cutting tool 2 with said reinforcing wires 6 is nevertheless avoided, in particular in order to avoid perforating the reinforcing ply 5, but also in order to avoid blunting, blocking or even breaking the cutting tool 2 against one or more of said reinforcing wires 6.

[0094] For this purpose, according to the invention, the method comprises, prior to the material removal step: - a step of analyzing the bandage 1 during which at least part of the layout diagram is identified according to which the reinforcing wires 6 of the reinforcing ply 5 are arranged within the bandage 1 to be machined, - then a step of adapting the cutting sequence during which the cutting sequence is defined by adapting said cutting sequence according to at least one part of the implantation diagram which was identified during the step of analyzing the bandage 1.

[0095] Thus, in accordance with the invention, during the step of analyzing the bandage, one or more pieces of information are acquired on one or more characteristics of the implantation diagram, and more particularly at least one piece of information on the orientation A6 of the reinforcing threads 6, then the parameterization of the cutting sequence is established from said information, here more particularly as a function of the orientation A6 of the reinforcing threads 6, which makes it possible to adapt the cutting sequence to each bandage 1, as a function of the implantation diagram of the reinforcing threads 6 to which the bandage 1 in question obeys.

[0096] Advantageously, the invention therefore provides first of all, during the step of analyzing the bandage 1, to search for the presence of one or more characteristics of the implantation diagram, for example the presence of reinforcing threads 6 which are parallel to each other and oriented obliquely with respect to the equatorial circumferential line L_EQ of the bandage 1, and where appropriate to quantify said characteristic or characteristics which will have been identified as being actually present, for example by measuring the value and the sign of the angle called “ply angle” A6_ang according to which said reinforcing threads are oriented, then subsequently, during the step of determining the cutting sequence, to apply one or more pre-established determination rules to generate, from the characteristics of the implantation diagram thus identified and / or quantified, an appropriate cutting sequence.

[0097] For this purpose, the method may provide a list of potential characteristics to be searched for, which will for example be pre-listed in a database or in a computer program used by the method, and each associated with a search and analysis protocol which, when applied during the bandage analysis step, makes it possible to determine whether or not the characteristic concerned is present within the layout diagram according to which the bandage 1 in question is arranged, and to quantify said characteristic if necessary.

[0098] The method according to the invention thus has the capacity to recognize several different implantation patterns and to distinguish between these different implantation patterns, such that the method is capable of identifying the implantation pattern which corresponds to that of the bandage 1 being treated.

[0099] The pre-established determination rules will then allow the method according to the invention to create a cutting sequence which takes into consideration the characteristics of the implantation diagram, in particular to impose certain constraints on the rotation R20 of the bandage as well as on the cutting trajectory T2_l, T2_2.

[0100] Said determination rules will make it possible to associate with each of the implantation diagrams capable of being recognized a specific cutting sequence parameterization, from among a plurality of available parameters, and therefore to select and define a specific cutting sequence from among several potential cutting sequences available.

[0101] The invention thus creates a link of dependency between the cutting sequence finally chosen and the implantation diagram which is present within the bandage 1 and from which the choice of the cutting sequence results.

[0102] Thus, it becomes possible to modify and optimize the cutting sequence differently for each new bandage 1 which is presented for machining, according to an individual setting, personalized for each bandage 1, and this in particular in order to carry out a passage of the cutting tool 2 as close to the reinforcing wires 6 as it is possible to do so in complete safety, taking into account the arrangement of said reinforcing wires 6 provided by the layout diagram which is specific to said bandage 1.

[0103] By making the parameterization of the cutting sequence dependent on the layout diagram of the reinforcing wires 6, the method according to the invention is therefore very versatile, since it adapts intrinsically to any layout diagram, and therefore to any type and dimensions of bandage 1, while being very safe, since it guarantees that, during the execution of the cutting sequence, any damaging collision of the tool with the reinforcing wires 6 is avoided, and therefore in particular any tearing, peeling, or tangling of said reinforcing wires 6.

[0104] Preferably, the step of analyzing the bandage, then the step of adapting the cutting sequence, then the execution of said cutting sequence during the material removal step, will be carried out automatically, by means of an appropriate control unit 51, such as an electronic or computer processing unit, typically an industrial programmable logic controller.

[0105] The determination rules which make it possible to associate a specific cutting sequence with a specific identified implantation diagram may be presented for example in the form of law tables, maps, or mathematical formulas which are contained in a non-volatile memory which is accessible to the control unit 51, and therefore implemented by the method.

[0106] Preferably, the step of analyzing the bandage is capable of identifying an implantation pattern according to which the reinforcing threads 6 extend parallel to each other within the reinforcing ply 5, and of identifying the orientation A6 of said reinforcing threads 6 relative to a reference direction called the “equatorial circumferential line” L_EQ which corresponds to the intersection of the radially external surface of the reinforcing ply 5 with a fictitious plane called the “equatorial plane” P_EQ which, as indicated above, is normal to the main axis Z20, and therefore to the central axis of rotation of the bandage, and passes through the middle of the axial range W1 occupied by said bandage 1.

[0107] More particularly, the orientation A6 may correspond to the so-called “ply angle” A6_ang that the reinforcing threads 6 of a reinforcing ply 5 located in the crown 10 of the tire 1 form, relative to the equatorial circumferential line L_EQ, i.e. the angle at which each reinforcing thread 6 is oriented in a lace around an imaginary radial line that is perpendicular to the main axis Z20 and that passes through the intersection of said reinforcing thread 6 with the equatorial circumferential line, as illustrated in FIGS. 6A, 7A, 8A, 12A and 14.

[0108] The orientation A6 of the reinforcing threads 6 may typically be defined by means of two parameters, namely the sign of the layer angle A6_ang and the value of said layer angle A6_ang, taking for example as a reference the equatorial circumferential line L_EQ, the orientation of which is considered to be zero degrees. By convention, it may be considered that the layer angle A6_ang is negative when, as is the case in FIG. 6A, it deflects the reinforcing thread 6 at an acute angle to the left (therefore in the trigonometric, anti-clockwise, yaw direction) relative to the equatorial circumferential line L_EQ, and that the layer angle A6_ang is positive when it deflects the reinforcing thread 6 at an acute angle to the right (in the clockwise yaw direction), as is the case for the first reinforcing threads 6 in [Fig. 14].

[0109] Knowledge of the orientation A6 of the reinforcing threads 6 will advantageously make it possible to adapt the direction of rotation R20+, R20- of the bandage 1 and the cutting path followed by the cutting tool 2 to prevent the cutting tool 2 from taking the reinforcing threads 6 against the grain and from lifting said reinforcing threads 6 out of the reinforcing ply 5 by accidentally catching the end of one or other of said reinforcing threads 6.

[0110] Preferably, during the step of adapting the cutting sequence, the cutting sequence is defined by adapting, as a function of at least one part of the diagram implantation which was identified during the bandage analysis step, at least one, preferably at least two, and more preferably each of the following three parameters: i) the direction of rotation R20+, R20- of the bandage 1, ii) the axial cutting range W2_l, W2_2, iii) the axial travel direction S2_l, S2_2 in which the cutting tool 2 is moved within the axial cutting range W2_l, W2_2.

[0111] These parameters have in fact been identified as relevant when seeking to machine a bandage 1 whose reinforcing threads 6 are oriented obliquely relative to the equatorial circumferential line L_EQ and when it is desired to avoid taking the ends of the reinforcing threads 6 against the grain, so as not to tear off the points formed by said reinforcing threads 6 at the axial ends 5_1, 5_2 of the reinforcing ply 5, that is to say at the lateral selvedges 5_1, 5_2 of the reinforcing ply 5.

[0112] The determination rules provided by the invention and applied during the step of adapting the cutting sequence advantageously make it possible to assign values to the various aforementioned parameters as a function of one or more characteristics of the implantation diagram which was identified during the step of analyzing the bandage, and more particularly as a function of the orientation A6 of the reinforcing threads which was identified during the step of analyzing the bandage.

[0113] More particularly, the determination rules may define, from the identified implantation diagram, and in particular as a function of the orientation A6 of the reinforcing threads which was identified during the bandage analysis step: (i) the sign, positive or negative, of the direction of rotation R20+, R20- to be used; ii) the axial position and the axial extent of the axial cutting range W2_l, W2_2, which can be defined by the two values which are the axial abscissa of its first terminal (first end of said axial cutting range) on the one hand, and the axial abscissa of its second terminal (second end of said axial cutting range) on the other hand; iii) the sign, positive or negative, of the axial direction of travel S2_l, S2_2, applicable in the axial cutting range considered.

[0114] More particularly, the determination rules may make it possible to choose, in particular as a function of the orientation A6 of the reinforcing threads 6, a combination of values of these parameters, and more particularly the combination of a sign of the direction of rotation R20+, R20- and a sign of the direction of axial travel S2_l, S2_2, which allows the cutting tool 2 to travel the reinforcing threads 6 in the correct direction, i.e. in the direction which tends to press against the reinforcing ply 5 and the carcass of the tire the points formed by said reinforcing threads 6 at the level of the lateral selvedges 5_1, 5_2 of the reinforcing ply 5 rather than to turn up and tear off said threads. reinforcement 6, when crossing the lateral edge 5_1, 5_2 of the reinforcement ply 5, and therefore the end of the reinforcement threads 6, which is located in the selected axial cutting range W2_l, W2_2.

[0115] For example, in the situation illustrated in Figure 6A, an axial cutting range W2_l will be chosen which corresponds to the first hemisphere H1 of the tire 1, a negative direction of rotation R20-, going from bottom to top in the figure, and a positive axial direction of travel S2_l, going to the right in the figure, so that the cutting tool 2 goes in the direction not only of the first reinforcing threads 6 present in the first reinforcing ply 5, radially the outermost, and which have a first negative orientation A6, but also in the direction of the second reinforcing threads 6' present in the second reinforcing ply 5', which is located under the first reinforcing ply 5 and which projects axially beyond the lateral edge 5_1 of said first reinforcing ply, said second reinforcing threads 6' having a second orientation A6' of the same sign, here negative, and possibly of the same angle value A6'_ang, as the first reinforcing threads 6.

[0116] Of course, the step of adapting the cutting sequence will also make it possible to define the cutting trajectory T2_l, T2_2 that the cutting tool 2 must follow, in the specified axial cutting range W2_l, W2_2, by fixing for example a set of passage points of said trajectory which will each be characterized by the position on the axial abscissa and the radial position of the passage point considered, relative to the main axis Z20.

[0117] In this respect, the radial positions of said passage points will preferably be defined in such a way that the cutting tool 2 travels through the external layer 4, over the extent of the specified axial cutting range W2_1, W2_2, while remaining at a distance from the reinforcing wires 6, here at a radial distance from the reinforcing wires 6 in the example of FIG. 6A, which is less than or equal to 2 mm, preferably less than or equal to 1 mm.

[0118] In particular, several of said passage points, preferably more than half of said passage points, or even all of said passage points defining the cutting path T2_l, T2_2 may be located at a radial distance from the main axis Z20 which is less, than the abscissa of the passage point considered, than the radial envelope distance D0_ply at which the reinforcing wires 6, 6' are located in the absence of radial action of the cutting tool 2, 2' on the wall 3, so that when the cutting tool 2, 2' travels the cutting path T2_l, T2_2, it maintains a forced centripetal radial depression of the wall 3 and of the reinforcing ply 5, 5' by centripetal elastic deformation in flexion of the reinforcing wires 6, 6'. As indicated above, such a choice allows the cutting tool 2, 2' to reach with certainty the implantation depth of the reinforcement layer 5, 5' and to maintain contact with said reinforcing sheet 5, 5', sliding along and in contact with the reinforcing wires 6, 6', at any point on the circumference of the wall which faces the cutting tool 2, 2'.

[0119] As an indication, the radial distance of the cutting tool 2, 2' from the main axis Z20 may be chosen to be at least 1 mm, preferably at least 2 mm less than the radial envelope distance D0_ply, more preferably less than the radial envelope distance by a value called the "nominal deflection value" D_bend of between 2 mm and 5 mm, for example equal to 3 mm.

[0120] Thus, according to a preferred characteristic which may constitute an invention in its own right, during the bandage analysis step, it is identified, at a given axial abscissa, which preferably corresponds to the abscissa of the starting point K1, K2 of the cutting path T2_1, T2_2, and even more preferably to the abscissa of the equatorial plane P_EQ, at what radial distance from the main axis Z20, called the “radial envelope distance” D0_ply, is the radially external limit of the reinforcing wires 6 of the reinforcing ply 5 located at said given abscissa, then, during the cutting path adaptation step, the cutting path T2_1, T2_2 is defined in such a way that said cutting path brings the cutting tool 2, when it is at the given abscissa, to a radial distance from the main axis Z20 which is strictly less than the radial envelope distance D0_ply of a value called “nominal deflection value” D_bend,for example less than the radial envelope distance D0_ply by a value called the “nominal deflection value” D_bend of between 2 mm and 5 mm, more preferably equal to 3 mm, so as to cause a radial depression of the wall 3 by elastic deformation in bending of the reinforcing wires 6, and thus create a prestress in radial compression of the cutting tool 2 against the external layer 4 supported by the reinforcing wires 6.,

[0121] Advantageously, it will be possible to preferably maintain over at least half, or even over at least 75%, or even over the entirety of the chosen axial cutting range W2_l, W2_2, a non-zero nominal deflection value D_bend, typically between 2 mm and 5 mm, and therefore a centripetal radial prestress and a local centripetal bending of the reinforcing wires 6, 6' under the action of the cutting tool 2, 2', in order to scrape the external layer 4 as close as possible to the reinforcing wires 6, 6', and more preferably in contact with said reinforcing wires 6, 6'.

[0122] To do this, it will be possible, for example, advantageously, while the cutting tool 2, 2' moves axially in the axial cutting range W2_l, W2_2, to control the cutting tool 2, 2' in radial force, for example so that the intensity of the centripetal radial force exerted by the tool against the wall 3 along the cutting path T2_l, T2_2 follows a setpoint equal to the intensity of the initial centripetal radial force which is exerted and measured when the cutting tool 2, 2' is positioned at the point of departure Kl, K2 from the cutting path T2_l, T2_2, applying the chosen nominal value of deflection D_bend.

[0123] More generally, according to a preferred characteristic which may constitute an invention in its own right, it will be possible, during the cutting sequence, to bring the cutting tool 2, 2' into contact with the reinforcing ply 5, and more particularly into contact with the reinforcing wires 6, and while the cutting tool 2, 2' moves axially in the chosen axial cutting range W2_1, W2_2, to control the cutting tool 2, 2' in radial force, so that said cutting tool 2, 2' slides into contact with the reinforcing ply 5, against the reinforcing wires 6.

[0124] To achieve such a centripetal radial force control, it is possible, for example, to use a pneumatic cylinder which radially presses the cutting tool 2, 2' against the wall 3, and more particularly against the reinforcing ply 5, 5', with the desired force intensity. A pneumatic cylinder in fact ensures both good control of the intensity of the force and a flexible, floating pneumatic suspension of the cutting tool 2, 2', which allows the latter to remain permanently in contact with the wall 3, and in compression against said wall 3, and more particularly against the reinforcing ply 5, 5', during the rotation R20 of the bandage 1, even in the event of irregularities in curvature or centering causing out-of-roundness.

[0125] Of course, in addition to the above considerations related to the radial positioning of the cutting tool 2, 2', the invention aims, as indicated above, to be able to travel through the reinforcing plies 5, 5', at least in part or even in full, along cutting paths T2_1, T2_2 whose orientation does not present any risk of damage with regard to the orientation A6, A6' of the reinforcing wires 6, 6'.

[0126] According to a preferred characteristic which may constitute an invention as such, the cutting sequence is defined by choosing the direction of rotation R20+, R20- of the bandage, the axial cutting range W2_l, and the axial travel direction S2_l such that: - the axial cutting range W2_l traveled by the cutting tool 2 extends axially from the abscissa of the equatorial plane P_EQ of the bandage to at least the axial abscissa of a first axial end of the reinforcing ply 5, called the “first lateral edge” 5_1, which is located axially distant from the equatorial plane P_EQ; or, more preferably, the axial cutting range W2_l, traveled by the cutting tool 2 extends axially from the abscissa of the equatorial plane P_EQ to at least the axial abscissa of a first axial end 1_1 of said bandage, in order to cover a first hemisphere H1 of the bandage 1, as illustrated for example in FIG. 6A; - the cutting tool 2 moves in an axial direction of travel S2_l which goes from the equatorial plane P_EQ towards said first axial end 5_1 of the reinforcement ply 5; respectively the cutting tool 2 moves in an axial direction of travel S2_l which goes from the equatorial plane P_EQ towards the first axial end 1_1 of the bandage 1, in this case located on the side of the equatorial plane P_EQ where the first axial end 5_1 of the reinforcement ply 5 is located; - the relative displacement of the cutting tool 2 with respect to the reinforcing ply 5, which can be represented for convenience in the form of a speed vector V2, has on the one hand a circumferential displacement component V2_circ, induced by the rotation R20 of the bandage 1, which has the same sign as the circumferential component A6_circ of the orientation A6 of the reinforcing wires 6, considered when said reinforcing wires 6 are traversed from the equatorial plane P_EQ towards the first axial end 5_1 of the reinforcing ply 5, respectively towards the first axial end 1_1 of the bandage 1, and on the other hand an axial displacement component V2_ax, which corresponds to the chosen axial direction of travel S2_l, which axial displacement component V2_ax has the same sign as the axial component A6_ax of the orientation A6 of the reinforcing wires 6,considered when traveling through said reinforcing threads 6 from the equatorial plane P_EQ towards the first axial end 5_1 of the reinforcing ply 5, respectively towards the first axial end 1_1 of the bandage 1.,

[0127] Thus, if we consider at a given instant, in a plane reference frame whose origin corresponds to the point of contact of the cutting tool 2, and more particularly of the cutting edge of the cutting tool 2, with the reinforcing ply 5, and more particularly with a reinforcing wire 6, at the instant considered, and whose base is defined by an axial vector, parallel to the main axis Z20, and a circumferential vector, perpendicular to the axial vector, then the speed vector V2 of the cutting tool 2 which characterizes, at the point of contact between the cutting tool 2 and the reinforcing ply 5, the displacement of the cutting tool 2 relative to the surface of the reinforcing ply 5, is located in the same quadrant of said reference frame as the direction vector tangent to the reinforcing wire 6 passing through the origin of the reference frame at the instant considered, for example in the South-East quadrant in FIG. 6A, and points in the same direction as said direction vector tangent to the reinforcing wire 6,for example to the right and down in Figure 6A.,

[0128] More particularly, the invention will make it possible to ensure that, by a judicious choice of the cutting sequence, and more particularly by a judicious selection of the direction of rotation R20+, R20- and the direction of axial travel S2_l, S2_2, the circumferential components V2_circ and respectively axial V2_ax of the speed vector V2 representing the movement of the cutting tool 2 relative to the reinforcing ply 5 are, at the moment when said cutting tool 2 axially crosses the axial end 5_1 of the reinforcing ply 5, and therefore the free ends of the reinforcing wires 6, of the same signs as the circumferential components A6_circ, respectively axial A6_ax of the direction vector, tangent to the reinforcing wires 6, which characterizes the orientation A6 of said reinforcing wires at the axial end 5_1 of said reinforcing ply 5.

[0129] Thus, the sliding of the cutting tool 2 along the reinforcing threads 6, and more particularly the sliding of the cutting tool 2 on the end of the reinforcing threads 6 at the moment when said cutting tool 2 crosses the lateral edge 5_1 of the reinforcing ply 5, will tend to smooth said reinforcing threads 6 and to keep them pressed within the reinforcing ply 5, without taking said reinforcing threads 6 against the grain, and therefore will not risk tearing said reinforcing threads 6.

[0130] It will be noted that, when one of the parameters of the cutting sequence is imposed, for example if it has been chosen to impose a direction of rotation R20+, R20-, then it will be possible to select and adapt, as a function of the orientation A6 observed of the reinforcing wires 6, the other parameters of the cutting sequence, in particular the choice of the hemisphere H1, H2 that it is desired to machine by sliding the cutting tool 2 in contact with the reinforcing wires 6, so that, taking into account the axial travel direction S2_l, S2_2 which imposes that the cutting tool 2 travels the chosen hemisphere from the equatorial plane P_EQ towards the pole of said hemisphere H1, H2, this axial travel direction S2_l, S2_2 corresponds to the correct direction of movement relative to the reinforcing wires 6 present in the hemisphere thus chosen.

[0131] For example, with reference to figures 5B and 6A, if, in a first case, a negative R20- direction of rotation is imposed (oriented from bottom to top in the figure), then one will choose, as illustrated in figure 6A, to machine the right hemisphere, located to the right of the equatorial plane in said figure.

[0132] Conversely, if we imposed, in a second case, a positive direction of rotation R20+, oriented from top to bottom in figure 6A, we would then opt for machining of the left hemisphere, located to the left of the equatorial plane P_EQ in figure 6A, instead of machining of the right hemisphere.

[0133] In this second case, the right hemisphere could be machined - either by passing a cutting tool 2, 2' in contact with the reinforcing wires 6 in said right hemisphere after having reversed the direction of rotation to obtain a rotation in the negative direction R20- allowing the reinforcing wires 6 to be taken in the correct direction in said right hemisphere, - or, if the positive direction of rotation R20+ were retained, and therefore the reinforcement wires 6 were required to be traversed against the grain in said right hemisphere, by planning to shift the cutting path, carried out in the right hemisphere, by a predetermined radial shift value Delta_T2, according to a principle analogous to that illustrated in the left part of figure 8B, so that the cutting tool 2, 2' passes at a radial distance from the reinforcement wires 6, in particular at the ends of these reinforcement wires 6 located in said right hemisphere.

[0134] Different means can be considered for identifying the implantation diagram of the bandage 1 which must be machined.

[0135] According to a first possible implementation, the step of analyzing the bandage may identify the bandage 1 by means of an identifier embedded on said bandage 1, said identifier being able for example to be a marking which is present on the side of the bandage, such as an explicit manufacturing batch number, a bar code or a matrix code (QR-code), or even an electronic identifier stored in an RFID chip integrated into the bandage.

[0136] From this identifier, it will be possible to access a database which will contain information on the bandage 1 itself and / or on the manufacturing batch from which said bandage 1 originates, and more particularly on information concerning the implantation diagram used to manufacture said bandage 1.

[0137] This solution may, however, have its limits when seeking to recycle tires from very diverse sources, the manufacturing data of which are not made accessible by the manufacturers.

[0138] This is why, according to another preferred implementation possibility, the step of analyzing the bandage may implement a measurement phase, during which the bandage 1 is physically inspected by means of one or more measuring devices, in order to identify the layout pattern of the reinforcing threads 6.

[0139] For example, the bandage 1 may be subjected to a measurement by X-ray radiography, so as to be able to acquire an image of the reinforcing ply 5, and of the reinforcing threads 6, through the thickness of the external layer 4 which still masks said reinforcing ply 5. While such a solution advantageously makes it possible to have a very complete view of the implantation diagram, it nevertheless requires having a radiography installation, and may therefore prove complex and costly to implement.

[0140] According to another option, an inspection of the bandage 1 may be carried out by probing, by locally digging the outer layer 4 in one or more zones of said outer layer 4, called “prospecting zones”, until reaching the reinforcing ply 5, in order to observe the arrangement of the reinforcing threads 6 in the portions of the reinforcing ply 5 thus made visible in said prospecting zone(s).

[0141] Such a probing inspection also advantageously makes it possible to empirically determine the radial position at which the reinforcing ply 5 is located relative to the main axis Z20, and more particularly to measure the radial envelope distance D0_ply at which the radially external limit of the reinforcing wires 6 is located when the wall 3 is free of any radial stress generated by the cutting tool 2. Such a probing inspection therefore makes it possible to precisely define a radial reference for parameterizing the cutting trajectory T2_l, T2_2.

[0142] It will be possible to consider probing the bandage 1 in several prospecting zones. distinct, disjointed from each other, and for example distributed in several different axial ranges over the width W1 of the bandage, in order to obtain a relatively complete and precise estimate of the implantation diagram.

[0143] Such a multiplication of surveys will, for example, make it possible to remove any uncertainty as to the axial extent of the reinforcing ply 5, and as to the possible presence, under a first reinforcing ply 5, of a second reinforcing ply 5' which extends axially beyond the lateral edges 5_1, 5_2 of the first reinforcing ply 5 and which has a second orientation A6' of reinforcing threads 6'.

[0144] However, in practice, the inventors have found that a single survey, in particular a survey carried out in the equatorial zone of the bandage 1, could be sufficient to obtain a reliable, or at least statistically reliable, estimate of the implantation pattern, or at least a reliable identification of a family of implantation patterns to which the observed implantation pattern belongs, all of which are pieces of information whose knowledge is sufficient in practice to be able to define a cutting sequence that does not present any risk.

[0145] This is why, preferably, during the step of analyzing the bandage, a circumferential annular trench 27, called an “exploration trench” 27, is dug in the external layer 4 using the cutting tool 2, until the reinforcement ply 5 is reached, as is for example illustrated in FIGS. 5A, 5B, 1 1A and 1 1B.

[0146] Advantageously, such a solution makes it possible to use the same equipment, namely the rotary support 20 and the cutting tool 2, both for digging said exploration trench 27, during the bandage analysis step, and for executing the cutting sequence during the material removal step.

[0147] Said exploration trench 27 can also advantageously constitute the axial starting point of the cutting trajectory T2_1, T2_2.

[0148] More particularly, it will thus be possible, in a first step, during the step of analyzing the bandage, to dig the exploration trench 27 by dressing, that is to say by making the cutting tool 2 penetrate into the outer layer 4, and by making said cutting tool advance through the thickness of said outer layer 4, towards the reinforcement ply 5, in a centripetal radial direction relative to the main axis Z20, until reaching said reinforcement ply 5, and more particularly until reaching the reinforcement wires 6 which are radially closest to the apparent surface of the outer layer 4 in the radial direction in which the cutting tool 2 penetrates into the outer layer 4, then, in a second step, to carry out the step of removing material by turning, by executing a cutting trajectory T2_1, T2_2 substantially or even strictly axial along the main axis Z20,at a radial distance from the main axis Z20 which will be defined from the radial position reached when digging the trench 27, and which will advantageously allow the cutting tool 2 to remain at a , distance of the reinforcing wires 6 less than or equal to 2 mm, preferably less than or equal to 1 mm, or even in contact with the reinforcing wires 6 by forced bending, as indicated above.

[0149] The analysis step may advantageously comprise a phase of detecting the arrival of the cutting tool 2 in contact with the reinforcement ply 5, in order to stop the radial penetration movement of the cutting tool 2 when it reaches the reinforcement ply 5.

[0150] This detection may be carried out by any appropriate means, for example by an electrical or electromagnetic detection means which will react to the proximity, or to the contact, between the cutting tool 2 and the reinforcing wires 6, in particular if said reinforcing wires 6 are metallic.

[0151] Another means of detection may consist of detecting by an optical sensor, such as a profilometer or a photographic device associated with an image analyzer, the appearance, at the bottom of the trench 27, of undulating reliefs on the surface which correspond to the reinforcing wires 6.

[0152] Yet another means of detection may consist of carrying out a comparison between, on the one hand, the radial position called the “constrained position” of the surface of the bandage in the angular sector called the “working angular sector” where the bandage is subjected to the action of the cutting tool 2 and, on the other hand, the reference radial position occupied by this same surface of the bandage in an angular sector called the “free angular sector”, which is sufficiently distant from the working angular sector where the cutting takes place so that the surface of the bandage is no longer subjected to the constraint of the cutting tool 2, and this in order to detect a depression which occurs, in the cutting angular sector, when the cutting tool 2 has exhausted the elastomeric material constituting the external layer 4 and causes a bending of the reinforcing threads 6.

[0153] More particularly, the cutting tool 2 can be gradually brought closer to the main axis Z20, according to a centripetal radial movement, which allows said cutting tool 2 to gradually penetrate into the external layer 4 to dig the exploration trench 27, and compare between them: - on the one hand the evolution, here the reduction, of the reference radial distance which separates the radially external surface of the wall 3, considered in the free angular sector, from the main axis Z20, radial distance which therefore decreases as the external layer 4 becomes thinner due to the fact that the cutting tool 2 actually digs into said external layer 4, - with on the other hand the evolution of the radial position of the cutting tool 2, which in fact corresponds to the constrained radial distance which is imposed by the cutting tool 2 on the surface of the wall 3 in the angular working sector, and detect the appearance of a threshold of divergence between these two developments, called “threshold characteristic deformation”, which makes it possible to observe that the radial reference position of the wall 3, here the bottom of the exploration trench 27, in the free angular sector no longer decreases, or almost no longer, while the cutting tool 2 continues to approach the main axis Z20, which means the cutting tool 2 has exhausted the elastomeric material constituting the external layer 4 and causes, in the angular working sector, a centripetal radial deformation in bending of the reinforcing wires 6, which said cutting tool 2 causes in its centripetal radial displacement without removing material from the wall 3, and therefore without reducing the apparent radius of the wall 3 in the free angular sector.

[0154] Advantageously, the radial reference position occupied by the wall 3, here by the bottom of the exploration trench 27, at the moment when the aforementioned divergence appears linked to the elastic flexion depression of the reinforcing wires 6 under the effect of the radial progression of the cutting tool 2, will correspond to the radial envelope distance D0_ply from which reference can be taken to define the cutting trajectories T2_l, T2_2.

[0155] Preferably, the axial range covered by the trench 27, and more particularly, the axial range of the portion of the reinforcing ply 5 which is made visible at the bottom of the trench 27 thanks to said trench 27, contains the axial abscissa of the equatorial plane P_EQ, so that the trench 27 constitutes an equatorial trench 27.

[0156] More preferably, the trench 27 is located inside an axial range called the “equatorial range” whose axial extent represents less than 50% of the axial width W1 of the tire 1, preferably less than 35% of the axial width W1, and which contains the abscissa of the equatorial plane P_EQ.

[0157] Thus, preferably, during the step of analyzing the bandage 2, the cutting tool 2 removes thickness from the external layer 4, and therefore from the wall 3, by digging an equatorial circumferential trench 27, in a central portion of the crown 10 which forms an equatorial band of the bandage 1.

[0158] An advantage is that the arrangement of the reinforcing threads 6 in the equatorial range is generally such, whatever the model of bandage 1, and therefore whatever the implantation scheme, that said reinforcing threads 6 are the least vulnerable to accidental peeling, in particular because the equatorial zone is distant from the lateral edges 5_1, 5_2 of the reinforcing ply 5 and from the ends of said reinforcing threads 6.

[0159] It will also be noted that the material extracted during the drilling, and more particularly the material extracted from the external layer 4 during the digging of the trench 27, can be advantageously recovered, in the same way as the material which will then be taken during the cutting sequence(s), and can even represent up to 30% or even 35% of the total material recovered by the method according to the invention.

[0160] Once the exploration trench 27 has been dug, the orientation A6 of the reinforcement wires 6 is identified by observing the apparent surface of the reinforcement sheet 5, which forms the bottom of the exploration trench 27.

[0161] In absolute terms, the operator could be involved in visually identifying the orientation A6 of the reinforcing threads 6, if necessary by direct observation of the reinforcing ply with the naked eye.

[0162] However, for the sake of convenience and efficiency, provision will preferably be made to identify the orientation A6 of the reinforcing wires 6 by observing the apparent surface of the reinforcing sheet 5, which forms the bottom of the exploration trench 27, a visual observation, by means of an optical detection device 50.

[0163] According to a possible implementation, semi-automatic, said optical detection device will be able to offer simple assistance to the operator, by acquiring and / or analyzing an image of the reinforcing ply 5, image from which the operator will be able to visualize the orientation A6 of the reinforcing threads 6, and act accordingly to indicate or confirm what is said orientation A6, to be taken into consideration to determine the cutting sequence.

[0164] According to another possible implementation, particularly preferred to reduce the cycle time and the cost of the process, the optical detection device 50 will be designed to detect the orientation A6 of the reinforcing wires 6 in a fully automatic manner, without the intervention of the operator.

[0165] Preferably, the optical detection device 50 may comprise: - a laser profilometer, arranged to measure by telemetry, on a predetermined angular sector around the main axis Z20, the reliefs of the apparent surface of the reinforcement ply 5 which are due to the reinforcement threads 6, and / or - an image acquisition device, such as a camera, making it possible to take a photograph of the apparent surface of the reinforcing sheet 5, and which is associated with an image processing unit.

[0166] In the case where a profilometer is used which scans the apparent surface of the reinforcement ply 5 over the axial width of the bottom of the exploration trench 27, the alternation of the reinforcement wires 6, which create projecting reliefs on the surface of the reinforcement ply 5, and the rubber interstices which separate two neighboring reinforcement wires 6 and which thus form hollows, causes undulations to appear on the apparent surface of the reinforcement ply 5, undulations whose crest lines correspond to the path of the reinforcement wires 6, and therefore make it possible to visualize the orientation A6 of the reinforcement wires.

[0167] In the case where one or more images are acquired by means of a camera, the path of the reinforcing wires 6, and therefore their orientation A6, can be revealed by applying to the acquired images one or more known filters, used by the image processing unit, by example a Fonder transform filter.

[0168] Preferably, for better reliability, the speed of rotation R20 of the rotary support 20, and therefore of the bandage 1, can be slowed down at the time when the optical detection device 50 is used to acquire the profilometer reading and / or the photographic image of the reinforcement sheet 5, relative to the nominal speed of rotation R20 which was used to dig the exploration trench 27.

[0169] Thus, for example, it will be possible to use a rotation speed R20 of the order of 3 rpm to 5 rpm to dig the exploration trench 27, while the cutting tool 2 is driven into the external layer 4 in a centripetal radial direction, then, when it has been detected that the cutting tool 2 has reached the required depth, in contact with the reinforcement layer 5, slow down the rotation speed R20 to 0.5 rpm to acquire the reading using the profilometer or the images using the camera, or even stop the rotation to acquire the clearest possible image with the camera.

[0170] However, if the optical detection device 50 is sufficiently efficient, and more particularly if the acquisition speed of the profilometer and / or the camera allows it, it will possibly be possible to maintain a rotation speed R20 equal to the nominal rotation speed used to dig the trench 27, for example between 3 rpm and 5 rpm, or even 10 rpm, while the optical detection device 50 acquires the information necessary for identifying the orientation A6 of the reinforcing wires 6.

[0171] Preferably, the wall 3 of the tire has a toroidal revolution shape, around the main axis Z20, and the section of said wall 3, considered in a radial plane containing the main axis Z20, has a shape that is generally curved towards the outside, as can be seen in particular in FIGS. 4, 5B, 6C, 7B, 8B, 10, 11B, 12B and 15.

[0172] The wall 3 can thus preferably have a concave shape with respect to the main axis Z20, and thus delimit, in the case where the tire 1 is a pneumatic tire, a cavity which makes it possible to contain the inflation gas of said pneumatic tire.

[0173] Preferably, when the wall 3 has a shape that is curved outwards, the step of analyzing the bandage comprises a step of selecting the cutting trajectory T2_l, T2_2 during which, depending on the sign of the orientation A6 of the reinforcing threads 6 relative to the equatorial circumferential direction L_EQ, the following are chosen: - or, if the orientation A6 of the reinforcing wires 6 has a first sign, for example a positive sign as illustrated in [Fig. 14], a cutting path T2_l, T2_2 called “straight cutting path”, according to which the cutting tool 2 remains at a constant radial distance from the main axis Z20 while said cutting tool 2 moves along the axis Z20. along said main axis Z20; more preferably, the cutting path T2_l, T2_2 will then be rectilinear and parallel to the main axis Z20; - or, if the orientation A6 of the reinforcing wires 6 has a second sign opposite to the first sign, for example a negative sign as in Figure 6A, a cutting path T2_l, T2_2 called “curved cutting path”, according to which the radial distance of the cutting tool 2 is varied relative to the main axis Z20, as the cutting tool 2 moves along said main axis, in order to give the cutting path T2_l, T2_2 a curvature which is of the same sign as the curvature that the wall 3 has, considered in the radial plane containing the main axis Z20, as is for example shown diagrammatically in Figures 6A and 7A.

[0174] The curved cutting path may be obtained by applying a predefined curved path, which may be identical from one bandage 1 to another, or possibly adapted according to certain parameters of the bandage 1, in particular according to the axial width W1 of the bandage.

[0175] One possibility for adapting the curved cutting path to the reinforcing ply 5, and more generally to the bandage 1, may consist of controlling the cutting tool 2 in radial force, as described above, for example so that the cutting tool 2 exerts against the wall 3, and more particularly against the reinforcing ply 5, 5', a centripetal radial force of constant intensity, while said cutting tool moves along the main axis Z20. The cutting tool 2 may thus dynamically adjust its radial position by substantially following the curvature that the reinforcing ply 5, and where appropriate the bandage 1, presents in a radial plane. It will be noted in this respect that, according to what may constitute a separate invention, the implementation of a radial force control makes it possible to slide the cutting tool 2 in contact with the reinforcing ply 5, along the reinforcing wires 6,whatever the possible irregularities of the surface of the reinforcing ply 5, in particular at the level of edges 5_1, 5_2, and / or whatever the curvature of the reinforcing ply 5, including for example in the event that, instead of presenting, in the usual manner, a concave curvature according to which the reinforcing ply 5 approaches the main axis Z20 in the shoulders, the reinforcing ply 5 would tend to rise in the shoulders, thus forming a convex curvature with respect to the main axis Z20, either because of the shape of the wall 3 which would be collapsed in the equatorial zone, with respect to the shoulders, at the time of the cutting sequence, or because of an implantation scheme which would structurally provide for a centrifugal radial raising of the reinforcing ply 5 in the shoulders.

[0176] Whatever the execution methods of the curved cutting path, the choice of a curved cutting path advantageously makes it possible to pass as close as possible to the reinforcing ply 5, or the reinforcing plies 5.5' over the entire axial width W1. of the bandage, both in the apex 10 and in the shoulders which form a curved transition between the apex 10 and each of the first and second flanks 11, 12 respectively. Indeed, the further one moves away from the equatorial plane P_EQ, the closer the cutting tool gets to the main axis Z20, which in particular allows said cutting tool 2 to substantially follow the curvature of the shoulders, and therefore the curved shape that the reinforcing ply 5, 5' presents in said shoulders. Thus, as much material as possible can be recovered.

[0177] The choice of such a curved cutting path, however, assumes that the bandage analysis step has made it possible to acquire the certainty that the implantation diagram is compatible with such a curved cutting path, and that, in particular, it is certain not to tear any reinforcing wires 6 in the shoulders, at the axial ends of the crown 10.

[0178] For example, in the case of a laminated structure conforming to the first layout diagram of Figures 3, 4 and 6A, the cutting tool 2, coming from the equatorial plane P_EQ, machines the first hemisphere H1 by first traversing a portion of the first reinforcing ply 5, then crossing the lateral edge 5_1 of said first reinforcing ply 5, before continuing along the second reinforcing ply 5', until reaching and crossing the lateral edge 5'_1 forming the axial end of said second reinforcing ply 5'.To the extent that the second reinforcing threads 6' are oriented in the same direction as the first reinforcing threads 6, here at a negative angle in both cases in Figures 3 and 6A, it is possible to serenely cross successively, without risk of tearing the first reinforcing threads 6 or the second reinforcing threads 6', the lateral edge 5_1 of the first reinforcing ply 5 then the lateral edge 5'_1 of the second reinforcing ply 5' while maintaining the same direction of rotation R20+ and the same direction of travel S2_l throughout the axial cutting range W2_l covering the first hemisphere Hl. The cutting tool 2 can thus slide successively over the first reinforcing wires 6 then over the second reinforcing wires 6', up to the ends of said second reinforcing wires 6', in contact with said first then second reinforcing wires 6, 6', and thus remove the external layer 4 flush with said first then second reinforcing wires 6, 6', as can be seen in FIG. 6C.

[0179] Conversely, the choice of a straight cutting path will allow the shoulders to remain, for safety reasons, and in particular in the case where doubt persists as to the exact and complete nature of the implantation diagram, a slight residual thickness of external layer 4. This residual safety thickness arises from the divergence which exists between the straight path on the one hand and the curvature of the shoulders of the bandage 1 which progressively folds said shoulders towards the main axis Z20 on the other hand. The presence of such a residual safety thickness advantageously avoids any risk of tearing of the reinforcing threads 6, 6' present in said shoulders.

[0180] A straight cutting path may in particular be a relevant choice when the layout diagram provides a laminated structure such as that of the third layout diagram illustrated in [Fig. 14], according to which the second reinforcing wires 6', located in the second reinforcing ply 5' which projects axially beyond the first reinforcing ply 5, have an orientation A6' whose sign, here positive, is opposite to the sign, here negative, of the orientation A6 of the first reinforcing wires 6. Indeed, the cutting tool 2, which moves at a constant radial distance from the axis, will thus be able to cross the lateral edge 5_1 of the first reinforcing ply 5, and therefore the ends of the first reinforcing wires 6, in the correct direction, in contact with said first reinforcing wires 6, whereas, because the second reinforcing ply 5' is installed deeper than the first reinforcing ply 5,and where appropriate, due to the fact that the second reinforcing ply 5' follows the curvature of the bandage 1 and therefore here gradually approaches the main axis Z20 as one approaches the shoulder and the first flank 11, the cutting tool 2 will pass at a slight radial distance from the ends of the second reinforcing wires 6', this time leaving a safety thickness, here a residual excess thickness Delta_4 of external layer 4 between the cutting tool 2 and the second reinforcing wires 6', when said cutting tool 2 crosses the lateral edge 5'_1 of the second reinforcing ply 5', as can be seen in [Fig. 15].

[0181] In this respect, it will be noted that the inventors have empirically observed that, in the majority or even all cases, the presence in the equatorial zone of first reinforcing threads 6 having a positive orientation A6, as in [Fig. 14], was, at least for certain values of angle A6_ang of said orientation A6, an indicative sign of the presence of a laminated structure in which a second reinforcing ply 5' projects axially beyond the first reinforcing ply 5 containing the first reinforcing threads 6, and in which the orientation A6' of the second reinforcing threads 6' was negative.The inventors concluded that it was advantageous to systematically opt for a straight cutting path, and more particularly a rectilinear cutting path at a constant distance from the main axis Z20, as soon as a positive orientation A6 of the first reinforcing wires 6 was detected in the equatorial zone, in order to provide, as a precaution, a residual safety thickness in the axial zone containing the ends of the second reinforcing wires 6.

[0182] Conversely, a negative orientation A6 of the first reinforcing threads 6, in particular in the equatorial zone, generally predicts a negative orientation A6' (therefore of the same sign) of the second reinforcing threads 6' of the laminated structure, as in FIGS. 3 and 6A, so that a curved trajectory is favored when a negative orientation A6 of the first reinforcing threads 6 is detected in the equatorial zone.

[0183] By convention, we can consider that the axial position of the cutting tool 2, and more particularly the axial position of the starting point Kl, K2 of the cutting path T2_l, T2_2, corresponds to the axial position of a reference point which belongs to the cutting tool 2, which corresponds to the point of the cutting edge of the cutting tool 2 which is in contact with the wall 3 of the bandage, in particular with the reinforcing ply 5, at the instant considered, and which is radially closest to the main axis Z20 (in particular if several points of the cutting tool are in contact with the wall 3 of the bandage 1).

[0184] According to a preferred characteristic which may constitute an invention in its own right, and whatever in particular the direction R20+, R20- of rotation chosen, or whatever the hemisphere H1, H2 primarily concerned by the cutting sequence considered, the cutting path T2_1, T2_2 has a starting point K1, K2 which is located axially, along the main axis Z20, at an axial position which is between 40% (lower limit) and 60% (upper limit) of the total length of the axial range W1 which is delimited by the first and second axial ends 1_1, 1_2 of the tire 1, considering that the axial position of the first axial end 1_1 corresponds to 0% of said total length, the axial position of the second axial end 1_2 corresponds to 100% of said total length, and the axial position of the middle of the straight line segment defined axially by the axial ends 1_1, 1_2, and therefore the axial position of the equatorial plane P_EQ,corresponds to 50% of the total length of the axial range Wl. ,

[0185] Thus, the starting point K1, K2 of the cutting path will be located in the equatorial zone of the bandage 1, in which the reinforcing threads 6 are not very vulnerable to tearing.

[0186] More preferably, the starting point K1, K2 of the cutting trajectory will be located in the exploration trench 27, as indicated above.

[0187] Preferably, the bandage 1 extending axially, along the main axis Z20, from a first axial end 1_1 to a second axial end 1_2, the material removal step comprises: - a first cutting sequence during which a cutting tool 2 travels, in a first axial direction of travel S2_l, a first axial cutting range W2_l which extends from a first starting point Kl situated axially between the first and second axial ends 1_1, 1_2 of the bandage, at a distance from each of the first and second axial ends 1_1, 1_2 of the bandage, said first starting point Kl preferably being situated at an axial position between 40% and 60% of the length of the axial range W1 between the first and second axial ends 1_1, 1_2 of the bandage, and more preferably situated in the equatorial plane P_EQ which passes through the middle of the axial range W1 occupied by the bandage, to a first arrival point Ml situated at least at the axial abscissa of the first end axial 1_1 of the bandage, or even beyond said axial abscissa of the first axial end 1_1 of the bandage, in the first axial direction of travel S2_l, - then a second cutting sequence during which a cutting tool 2, 2' travels, in a second axial direction of travel S2_2 opposite to the first axial direction of travel S2_l, a second axial cutting range W2_2, complementary to the first axial cutting range W2_l, from a second starting point K2 located in the first axial cutting range W2_l, preferably at the same abscissa as the first starting point Kl, and more preferably in the equatorial plane P_EQ of the bandage 1, to a second arrival point M2 located at least at the axial abscissa of the second axial end 1_2 of the bandage, or even beyond said axial abscissa of the second axial end 1_2 of the bandage, in the second ... axial path S2_2.

[0188] In other words, the first hemisphere H1 is advantageously processed by a first cutting sequence, following a first cutting trajectory T2_l which travels at least through said first hemisphere H1 in the first axial direction of travel S2_l, and the second hemisphere H2 by a second cutting sequence, following a second cutting trajectory T2_2 which travels at least through said second hemisphere H2 in the second axial direction of travel S2_2 opposite to the first axial direction of travel S2_l, i.e. by performing a first cutting trajectory T2_l and a second cutting trajectory T2_2 substantially mirroring each other with respect to the equatorial plane P_EQ.

[0189] It will be noted that, for simple convenience of description, the same reference “W1” can be used to designate the axial width of the bandage 1 and the axial range occupied by the bandage 1.

[0190] Advantageously, the second axial cutting range W2_2 is complementary to the first axial cutting range W2_l so that the second axial cutting range W2_2 covers at least the part of the axial width W1 of the tire which is not covered by the first cutting range W2_l, and vice versa.

[0191] In this way, at the end of the execution of the first and second cutting sequences, the cutting tool(s) 2, 2' will have cumulatively covered, by the two corresponding cutting trajectories T2_l, T2_2, the entire axial width W1 of the bandage 1, and thus recovered all the material which is accessible over said axial width Wl.

[0192] Furthermore, by providing two distinct cutting sequences, each of which is dedicated to a hemisphere H1, H2 of the bandage 1, the invention advantageously makes it possible to specifically adapt the first cutting sequence to the first hemisphere H1 and the second cutting sequence to the other, second, hemisphere H2, which sometimes makes it possible to optimize the machining cycle time, typically when the same direction of rotation R20+, R20- is kept to machine the two hemispheres H1, H2, and sometimes to optimize the quantity of material recovered, typically when adjusting the direction of rotation R20+, R20- to each of the first and second cutting sequences, in particular depending on the orientation A6 of the first reinforcing wires 6, in order to be able to choose a first cutting trajectory T2_l and a second cutting trajectory T2_2 which each pass into contact with the first reinforcing wires 6, and where appropriate also into contact with the second reinforcing wires 6'.

[0193] It will also be noted that the transition between the digging of the exploration trench 27 and the first cutting sequence can be carried out according to several execution variants.

[0194] According to a first variant embodiment, when the cutting tool 2 which digs the exploration trench 27 reaches the reinforcement layer 5, the cutting tool 2 is moved away from said reinforcement layer 5, preferably according to a centrifugal radial recoil movement relative to the main axis Z20, the layout pattern of the reinforcement wires 6 visible at the bottom of the trench 27 is identified, and more particularly the orientation A6 of said reinforcement wires 6 is identified, the parameters of the cutting sequence are decided, then the cutting tool 2 is engaged again against the reinforcement layer 5, by pushing it into the trench 27, to thus place said cutting tool at the starting point of the cutting path, then the axial movement of the cutting tool 2 is initiated in the chosen axial travel direction S2_l, S2_2.

[0195] If necessary, the cutting tool 2 is thus pushed radially into the trench until it reaches the radial distance which has been defined by applying the nominal value of deflection D_bend decided, to prestress the cutting tool 2 in contact with the reinforcing wires 6 and locally cause centripetal radial bending of said reinforcing wires 6.

[0196] According to a second variant embodiment, once the reinforcement ply 5 has been reached, and more particularly, if necessary, once the radial position integrating the chosen nominal deflection value D_bend has been reached, the cutting tool 2 can be held at the bottom of the exploration trench 27 while the layout diagram, and more particularly the orientation A6 of the reinforcement wires 6, is identified, then the axial movement of the cutting tool 2 can be directly initiated in the chosen axial travel direction S2_l, S2_2, without first causing the cutting tool 2 to perform, within said exploration trench 27, a centrifugal radial recoil movement followed by a new centripetal radial approach. Advantageously, this second variant will make it possible to reduce the cycle time of the machining operation.

[0197] It will also be noted that, preferably, and in particular in order to avoid having to completely stop the rotation R20 of the support 20 and the bandage 1 at the end of the operation of digging the exploration trench 27, the same direction of rotation R20+, R20- will be maintained during the operation of digging the exploration trench 27 and then during the first cutting sequence which immediately follows the operation of digging.

[0198] For this purpose, it will be possible to select the hemisphere H1, H2 that it is desired to machine during the first cutting sequence, and in which it is desired to remove a maximum of material by passing the cutting tool 2, 2' in contact with the reinforcing wires 6, as a function on the one hand of the direction of rotation R20+, R20- used during the operation of digging the trench 27, and therefore imposed for the first cutting sequence, and on the other hand of the detected orientation A6 of the reinforcing wires 6, the selection of said hemisphere being carried out in such a way that the reinforcing wires 6 present in the chosen hemisphere are presented in the correct direction with respect to the cutting tool 2, 2', taking into account said direction of rotation R20+, R20- imposed.

[0199] For example, if, in Figures 5A and 5B, a negative direction of rotation R20- is used to dig the trench 27, that is to say a direction of rotation which goes from bottom to top in Figure 6A, then, taking into account the orientation A6 of the reinforcing wires 6, we will continue with a cutting sequence in which we machine the right hemisphere, located to the right of the equatorial plane in Figure 6A, as illustrated in said Figure 6A. Conversely, if trench 27 had been dug using a positive R20+ rotation direction, oriented from top to bottom in Figure 6A, it is in the left hemisphere that such a positive R20+ rotation direction would avoid taking the reinforcement wires 6 against the grain, as can be understood by viewing the geometric diagrams presented in the left half of Figure 7A, and it is therefore the left hemisphere that would be chosen to carry out the first cutting sequence.

[0200] Preferably, the first cutting sequence is executed by means of a first cutting tool 2, and the second cutting sequence is executed by means of a second cutting tool 2' distinct from the first cutting tool 2.

[0201] Advantageously, by providing two cutting tools 2, 2' each assigned to a cutting sequence, it will be possible to optimize each of the first and second cutting sequences, and in particular the respective cutting trajectory T2_1, T2_2 of each of the cutting tools 2, 2', independently of one another, and / or, where appropriate, have the possibility of executing said first and second cutting sequences either simultaneously, one at the same time as the other, or sequentially, one after the other, the second cutting sequence starting after the end of the first cutting sequence.

[0202] Preferably, and in particular in order to avoid interference of the second cutting tool 2' with the first cutting tool 2, in particular in the equatorial zone of the bandage 1, the first cutting tool 2 and the second cutting tool 2' will be offset in azimuth relative to each other around the main axis Z20, in order to each occupy a distinct angular sector around the main axis Z20.

[0203] The first cutting tool 2 and the second cutting tool 2', and more particularly their respective points of contact with the wall 3 of the bandage 1, can thus be distant from each other in azimuth by at least 30 degrees, preferably at least 90 degrees, or even at least 120 degrees, and for example be substantially diametrically opposed, typically 180 degrees + / - 20 degrees from each other, as illustrated in Figures 1 and 2.

[0204] Each cutting tool 2, 2' will preferably be carried, positioned and moved by a positioning system 42, 42', comprising for example a robotic arm 44, 44'.

[0205] When two cutting tools 2, 2' are used, it will thus be possible to provide, preferably on either side of the rotary support 20, a first robotic arm 44 carrying the first cutting tool 2 and a second robotic arm 44', distinct and independent from the first robotic arm 44, carrying the second cutting tool 2'.

[0206] It will be noted that, when there is no need, in the description, to specifically distinguish between the first cutting tool 2 and the second cutting tool 2', and in particular when considering characteristics which could apply indifferently to one or the other cutting tool 2, 2', to an installation 40 which would comprise a single cutting tool 2 or to an installation 40 which would comprise several cutting tools 2, 2', in particular two cutting tools 2, 2', the present description may, for convenience, refer generically to a "cutting tool 2, 2'", or even to a "cutting tool 2".

[0207] Preferably, and as can be seen in Figures 1, 2 and 13, the cutting tool 2, and more preferably each of the first and second cutting tools 2, 2', is formed by a cylindrical knife 25, 25' with a circular base, driven in rotation R25 around its generating axis Z25, Z25', and of which a circular edge 25A forms the cutting edge which engages the wall 3 of the bandage.

[0208] Such a cylindrical knife 25 advantageously provides a precise, clean and regular cut, which makes it possible to remove the constituent material of the external layer 4 in the form of shavings or strips.

[0209] The generator axis Z25, around which said cylindrical knife 25 rotates in rotation R25 on itself while the bandage 1 is itself driven in rotation R20 by its support 20, is advantageously oriented so that said cylindrical knife 25, and more particularly its edge 25A, is presented in a manner substantially tangent to the visible surface, in movement, of the wall 3, and more preferably slightly obliquely relative to said visible surface.

[0210] Thus, more preferably, in order to promote the penetration of the edge 25A of the cylindrical knife 25 into the wall 3 and to clear the space necessary for the robotic arm 44, the generator axis Z25 of the cylindrical knife will have, in a plane normal to the main axis Z20, and more particularly in a plane normal to the main axis Z20 passing through the point of the edge 25A which is in contact with the wall 3 and closest to the main axis Z20, an angle of inclination relative to the tangent to the perimeter of wall 3, for example an angle of inclination of the order of 15 degrees.

[0211] Each cylindrical knife 25, 25' will preferably be provided with a sharpening system 45, comprising for example a sharpening wheel, which will allow the cutting edge to be automatically sharpened during or after the cutting operation.

[0212] The edge 25A forming the cutting edge may preferably form a smooth edge 25A which is in the form of a continuous wall, like the first knife 25 shown to the right of the bandage 1 in Figures 1 and 2, or in [Fig. 13]. Such a smooth edge 25A will have in particular the advantage of not having any roughness likely to accidentally catch a reinforcing wire 6.

[0213] However, as a variant, it is not excluded that one or other of the cylindrical knives 25 may have a crenellated shape, according to which grooves, preferably parallel to the generating axis Z25, subdivide said edge 25A into a succession of blades which form as many teeth distributed over the circumference of said edge 25A, as is the case of the second knife 25' shown to the left of the bandage 1 in Figures 1 and 2. Such a toothed knife can in fact facilitate the fractionation of the cut material into small chips, and therefore limit the volume necessary to store the material thus recovered. On the other hand, such a toothed cylindrical knife must not be pressed into contact with the reinforcing wires 6, 6', to avoid any tearing, so that the corresponding cutting path must provide a radial position of the cutting tool 2 which makes it possible to preserve, for safety, a residual thickness of external layer 4.

[0214] Preferably, the cylindrical knife 25, 25' will have a diameter between 100 mm and 300 mm.

[0215] The cylindrical knife 25, 25' may also be associated with a chip evacuation chute 46, as illustrated in [Fig. 13], which chute 46 will guide the material removed from the bandage 1 towards a recovery system, comprising for example an evacuation conveyor which may itself open directly above a recovery tank into which said conveyor will discharge the material extracted from the external layer 4 of the bandage 1.

[0216] According to one possible implementation, the first cutting sequence and the second cutting sequence are executed one after the other, and, at the end of the first cutting sequence, the direction of rotation R20+, R20- of the bandage is reversed, so as to execute the second cutting sequence using a second direction of rotation R20+ which is of opposite sign to the first direction of rotation R20- which was used during the first cutting sequence.

[0217] As an example, the second cutting sequence illustrated in Figure 7A, which makes it possible to machine the second hemisphere H2, here the left hemisphere in said Figure 7A, is executed after the first cutting sequence illustrated in Figure 6A and using a positive direction of rotation R20+, opposite to the negative direction of rotation R20- which is implemented during the first cutting sequence which is illustrated in Figure 6A and which makes it possible to machine the first hemisphere H1, here on the right in said Figures 6A and 7A.

[0218] Advantageously, the inversion of the direction of rotation R20+, R20- of the bandage 1 makes it possible to treat, one after the other, each hemisphere H1, H2 in the correct direction relative to the orientation A6, A6' of the reinforcing threads, and therefore to machine the external layer 4 as close as possible to said reinforcing threads, and more particularly in contact with the reinforcing threads 6, 6', in each of the two hemispheres H1, H2.

[0219] More particularly, the second cutting trajectory T2_2 implemented during the second cutting sequence will then preferably be of the same nature as the first cutting trajectory T2_l implemented during the first cutting sequence, i.e. curved if the first cutting trajectory T2_l is curved, or on the contrary straight if the first cutting trajectory T2_l is straight. More preferably, the second cutting trajectory T2_2 may be symmetrical to the first cutting trajectory T2_l with respect to the equatorial plane P_EQ.

[0220] The orientation of the first and second cutting tools 2, 2' must of course be adapted to the change in direction of rotation R20+, R20-. Thus, as can be seen in particular in Figures 1 and 2, the cutting edge of the first cutting tool 2, here the edge 25A of the first cylindrical knife 25 carried by the first robotic arm 44 located to the right of the rotary support 20 in said Figures 1 and 2, must point in opposition to the first direction of rotation R20-, while the cutting edge of the second cutting tool 2', here the edge of the second cylindrical knife 25' carried by the second robotic arm 44' located to the left of the rotary support 20, must point in opposition to the second direction of rotation R20+. In the example of Figures 1 and 2, the edges 25A of each of the two knives 25, 25' thus both point upwards.

[0221] According to another possible implementation, the first cutting sequence and the second cutting sequence are executed using the same direction of rotation R20+, R20-, and more preferably are executed simultaneously.

[0222] Advantageously, because the same direction of rotation R20+, R20- of the bandage 1 is used to carry out the two cutting sequences, there is no need to reverse the direction of rotation R20+, R20- between the first cutting sequence and the second cutting sequence, so that the time and energy that would otherwise be necessary to brake, stop, then restart the support 20 in rotation R20 in the desired direction are saved.

[0223] Furthermore, the simultaneous execution of the two cutting sequences makes it possible to carry out the second cutting sequence in masked time compared to the first cutting sequence, and thus reduce the cycle time of the machining operation.

[0224] Of course, if one opts for a direction of rotation R20+, R20- common to the two cutting sequences, and more particularly for the simultaneity of the two cutting sequences, then the first and second cutting tools 2, 2' will both be oriented accordingly, depending on the single direction of rotation R20+, R20- chosen.

[0225] More particularly, the two cylindrical knives 25, 25' will then be oriented so as to each present their cutting edge in opposition to the chosen direction of rotation R20+, R20-. Thus, on an installation such as that shown in Figures 1 and 2, the first knife 25, located on the right in said Figures 1 and 2, will point for example upwards, if a negative direction of rotation R20- is chosen, here a clockwise direction in said Figures 1 and 2, while the second knife 25', located on the left in said Figures 1 and 2, here diametrically opposite the first knife 25 relative to the main axis Z20, will no longer point upwards but downwards, in opposition to this same negative direction of rotation R20-.

[0226] Preferably, when the first cutting sequence and the second cutting sequence are executed using the same direction of rotation R20+, R20-, or, more particularly, when the first cutting sequence and the second cutting sequence are executed simultaneously, then the second cutting path T2_2 which is applied during the second cutting sequence, and which is more preferably traveled by the second cutting tool 2', has a centrifugal radial offset, denoted Delta_T2, relative to the first cutting path T2_l which is applied during the first cutting sequence, and which is here preferably traveled by the first cutting tool 2, as illustrated in FIGS. 8A and 8B, so as to preserve a residual excess thickness Delta_4 of external layer 4 in the second axial cutting range W2_2 relative to the first axial cutting range W2_l.

[0227] Advantageously, it is thus possible to preserve a residual safety thickness in the axial cutting range, here the second axial cutting range W2_2, and therefore more particularly in the second hemisphere H2, in which the cutting tool, here the second cutting tool 2', will travel the reinforcing wires 6, 6' against the grain, so that the cutting tool 2' remains at a distance from said reinforcing wires 6, 6' in the risk zone(s), in particular when crossing the axial position of the ends of said reinforcing wires 6, 6', while, conversely, the cutting tool, here the first cutting tool 2, will be able to slide in contact with the reinforcing wires 6, 6' in the other axial cutting range, here the first axial cutting range W2_l, and therefore in the first hemisphere Hl, where said reinforcing wires 6, 6' are oriented in the common sense taking into account the direction of rotation R20- and the direction of axial travel S2_l.

[0228] In other words, it will be possible, in order to maintain the benefit provided in terms of saving time and energy by machining using a single direction of rotation, taking more precautions in hemisphere H2 where the reinforcing wires are run against the grain than in hemisphere H1 where the reinforcing wires are run in the right direction, by machining the external layer 4 less deeply in the second hemisphere H2 than in the first hemisphere H1.

[0229] This may result in exposing the reinforcing ply 5, and more particularly the reinforcing threads 6, in the first hemisphere H1, and in maintaining a slight residual thickness E4 of external layer 4 which covers the reinforcing ply 5 in at least part or even all of the portion of the reinforcing ply 5 which extends into the second hemisphere H2, as can be seen in FIGS. 8A and 8B.

[0230] As an indication, the centrifugal radial offset Delta_T2 will be between 1 mm and 3 mm.

[0231] The centrifugal radial offset Delta_T2 may be chosen in such a way that the second cutting tool 2' follows a second cutting path T2_2 which remains outside the radial envelope distance D0_ply, i.e. the second cutting tool 2' remains radially set back towards the outside relative to the position of the reinforcing wires 6, and therefore cannot reach said reinforcing wires 6.

[0232] Furthermore, it is possible to implement an evolving centrifugal radial offset Delta_T2, for example which will be zero at the abscissa of the equatorial plane P_EQ, at the starting point K2 of the second cutting trajectory T2_2, and which will become positive from a certain axial distance from the equatorial plane P_EQ, so that the second cutting tool 2' will move away from the reinforcing wires 6, in order to leave a residual thickness of external layer 4, only when the second cutting tool 2' approaches the second edge 5_2 of the reinforcing ply 5 located in the second hemisphere H2 and exceeds said second edge 5_2.

[0233] In this respect, it will be noted that, according to a possible implementation of the invention, the first positioning system 42 forms a master positioning system which executes a first cutting trajectory T2_l according to which said first positioning system 42 axially moves the first cutting tool 2 from the equatorial plane P_EQ by sliding said first cutting tool 2 in contact with the reinforcing ply 5, along the reinforcing wires 6, preferably by controlling the first cutting tool 2 in radial force as explained above, while the second positioning system 42' forms a slave positioning system within which the execution of the second cutting trajectory T2_2 is delayed in time, according to which said second positioning system 42' axially moves the second cutting tool 2' from the equatorial plane P_EQ, relative to the execution of the first cutting trajectory T2_l.

[0234] It is then advantageously possible to detect a crossing by the first cutting tool 2 of a first lateral edge 5_1 of the reinforcing ply 5 in the first hemisphere H1, and to control the second positioning system 42' so as to introduce into the second cutting trajectory T2_2 a centrifugal radial offset Delta_T2 allowing the second cutting tool 2' to pass radially at a distance from the reinforcing ply 5 when said second cutting tool 2' passes, in the second hemisphere H2, by an abscissa which is the mirror image, with respect to the equatorial plane P_EQ, of the abscissa of the first lateral edge 5_1 crossed by the first cutting tool 2.

[0235] More particularly, for this purpose, it will be possible to measure, during the execution of the first cutting path T2_l, radial positions which are successively adopted by the first cutting tool 2 controlled in radial force, along the first cutting path T2_l in contact with the reinforcing ply 5, and to control the second cutting tool 2' in radial position, from the measured radial positions of the first cutting tool 2, so as to be able to introduce a centrifugal radial offset Delta_T2 in the second cutting path T2_2 if, in the first hemisphere H1, a variation in the radial position of the first cutting tool 2 is detected which is representative of the axial crossing, by the first cutting tool 2, of an edge 5_1 of the reinforcing ply 5.

[0236] To obtain a deferred execution of the second cutting path, in order to leave the first cutting path T2_l with a necessary advance to allow the control unit 51 to detect the crossing of the first edge 5_1 in the first hemisphere and to adjust the second cutting path T2_2 accordingly, the axial movement of the second cutting tool 2' in the second hemisphere H2 along the second cutting path T2_2 may be triggered when the first cutting tool 2 crosses, in the first hemisphere H1, a predetermined axial abscissa threshold away from the equatorial plane P_EQ, or at the end of a predetermined time delay from the triggering of the axial movement of the first cutting tool 2 along the first cutting path T2_l.

[0237] Of course, the invention also relates to an installation 40 making it possible to implement a method as described above.

[0238] Thus, the invention relates to an installation 40 intended to machine a bandage 1, said bandage 1 having a wall 3 which comprises at least one external layer 4 based on elastomer, preferably based on vulcanized rubber, and at least one reinforcing ply 5, which is located under said external layer 4 and which contains a plurality of reinforcing threads 6 arranged according to an implantation pattern specific to the bandage, said installation comprising: - a rotating support 20 which is arranged to receive the bandage, which rotating support is mounted in rotation on a frame 30 around a main axis Z20 and associated with a drive system 41 which makes it possible to drive said rotary support 20, and therefore the bandage 1, in rotation R20 on itself around said main axis Z20, - at least one cutting tool 2, 2', - a positioning system 42, 42' which makes it possible to move the cutting tool 2, 2' relative to the frame 30 and to the rotary support 20, while the rotary support carrying the bandage is driven in rotation R20, so as to make the cutting tool 2, 2' execute a cutting path T2_l, T2_2 which allows the cutting tool 2, 2' to remove material from the external layer 4 as said cutting tool 2, 2' progresses along said cutting path T2_l, T2_2, - a control unit 52 arranged to control the drive system 41 and the positioning system 42 in order to implement the rotation R20 of the support 20 and the cutting path T2_l, T2_2 of the cutting tool 2 according to a predefined cutting sequence, said installation being characterized in that it comprises: - a system 53 for analyzing the bandage arranged to identify at least part of the layout diagram according to which the reinforcing wires 6 of the reinforcing ply 5 are arranged within the bandage 1 to be machined, - and a unit 54 for adapting the cutting sequence which is arranged to define the cutting sequence which will be applied by the control unit 52 by adapting said cutting sequence as a function of at least one part of the implantation diagram which has been identified by the bandage analysis system 53.

[0239] The control unit 52, the bandage analysis system 53 and the unit 54 for adapting the cutting sequence will preferably be electronic or computer-based, and will allow automatic performance of the steps of bandage analysis, adaptation of the cutting sequence, and execution of the cutting sequence.

[0240] They may advantageously be grouped within the control unit 51, for example formed by a computer or an industrial programmable automaton.

[0241] The rotational movements of the support 20, of positioning and movement of the cutting tool or cutting tools 2, 2', of rotation of the cylindrical knives 25, 25', may be provided by electric motors, controlled by the control unit 52.

[0242] The bandage analysis system 53 may comprise, as mentioned above, an optical detection device 50 comprising a laser profilometer and / or an image acquisition device.

[0243] Alternatively, the bandage analysis system 53 could however use an electrical or electromagnetic device making it possible to detect the orientation of the reinforcing threads 6, in particular if said reinforcing threads are metallic and therefore electrical. strictly conductive.

[0244] For example, an excitation electrode could be applied in the middle of the axial range occupied by the portion of reinforcement sheet 5 which is exposed at the bottom of the exploration trench 27, in order to place one or more reinforcement wires 6 under tension, and provide a set of receiving electrodes, distributed axially over the width of the trench 27, in contact with the reinforcement sheet 5, and offset in azimuth around the main axis Z20 relative to the excitation electrode, so that it is possible to guess in which direction the electrified reinforcement wires are pointing by noting which receiving electrodes are stimulated, those located axially to the left of the excitation electrode, or those located axially to the right of the excitation electrode.

[0245] Furthermore, as indicated above, the installation will preferably comprise two cutting tools 2, 2', in this case two cylindrical knives 25, 25', each having its own positioning system 42, 42', here comprising respectively a first robotic arm 44 carrying the first knife 25 and a second robotic arm 44' carrying the second knife 25'.

[0246] Each robotic arm 44, 44' will advantageously allow the knife 25, 25' that it carries to describe any useful cutting trajectory T2_l, T2_2 opposite the wall 3 of the bandage 1, in the cutting range W2_l, W2_2 chosen and in the axial travel direction S2_l, S2_2 chosen, and in particular to access, and travel through, both the first hemisphere H1 and the second hemisphere H2 of the bandage.

[0247] As indicated above, the positioning system 42, 42', and more particularly one and / or the other arm 44, 44', may comprise a pneumatic cylinder to radially press the cutting tool 2, 2' against the wall 3 of the bandage 1, and where appropriate control said cutting tool in radial force.

[0248] Three examples of implementation of the invention will now be briefly described in relation to the figures.

[0249] FIRST EXAMPLE

[0250] The bandage 1 is placed on the support 20 and said bandage is rotated in the negative R20 direction, i.e. the clockwise direction in FIGS. 1 and 2, for example at a speed of 3 rpm.

[0251] The first knife 25 is then rotated around its generating axis Z25 and said first knife is pushed in a centripetal radial movement into the top 10 of the bandage, in order to hollow out the external layer 4 as illustrated in FIG. 5B.

[0252] As soon as it is detected that the first knife 25 has reached the radially outermost reinforcement ply 5, the rotation of the support 20 is slowed down, without stopping it, for example to bring it to 0.5 rpm / second.

[0253] The optical detection device 50 is then used to determine the presence of wires. reinforcement 6 at the bottom of the trench 27, and identify, among other characteristics of the implantation diagram, the orientation A6 of said reinforcement wires 6, by measuring the value of the layer angle A6_ang and the sign of said layer angle.

[0254] Here, as can be seen in Figures 5A and 6A, it can be seen that the reinforcing threads 6 have a “left” orientation, i.e. a negative orientation.

[0255] Taking into account the direction of rotation in progress, and the identified orientation A6 of the reinforcing wires 6, the hemisphere and the direction of travel which are compatible with sliding of the cutting tool 2 in contact with the reinforcing wires 6 are preferably chosen.

[0256] Here, taking into account the negative orientation of the reinforcing wires 6 and the negative sign of the direction of rotation R20-, it is decided to start the machining with the right hemisphere, that is to say the hemisphere located to the right of the equatorial plane P_EQ in FIGS. 5A, 6A, 6C, so that the reinforcing wires 6 are presented in the correct direction. The first axial cutting range W2_l chosen for the first cutting sequence therefore covers a first hemisphere H1 which corresponds to the right hemisphere.

[0257] Furthermore, the orientation A6 of the reinforcing wires, possibly supplemented by other information such as the spacing between neighboring reinforcing wires 6, makes it possible to identify the implantation pattern, and in particular to conclude with a reasonable degree of certainty that we are in the presence of a first implantation pattern as described above, comprising a first reinforcing ply 5 and a second underlying reinforcing ply 5', the respective reinforcing wires 6, 6' of which are oriented according to the same sign, here a left-hand orientation. We can therefore opt for a first curved cutting trajectory T2_l.

[0258] The rotation of the support 20 is then accelerated, for example to reach a speed of 3 rpm / second.

[0259] The support 20, and therefore the bandage 1, is allowed to make at least one complete turn on itself, around the main axis Z20, while the knife 25 is in the trench 27, in contact with the reinforcing ply 5, at its starting point Kl, then the knife 25 begins to be moved axially in the direction of the pole of the first hemisphere Hl, until the arrival point Ml is reached, as illustrated in FIG. 6A.

[0260] In doing so, the material constituting the external layer 4 in the first hemisphere H1 is removed by rolling.

[0261] Advantageously, the knife 25 slides along the reinforcing wires 6, at a radial distance from said reinforcing wires which is, depending on the quality of the cutting edge of the knife 25, less than or equal to 1 mm, or even zero so that said knife slides in contact with said reinforcing wires 6. For this purpose, as indicated above, it will be possible to choose a suitable nominal value of deflection D_bend, and apply this value to fix the radial distance of the cutting tool 2 relative to the main axis Z20 so as to force a centripetal radial bending of the reinforcing wires 6.

[0262] Advantageously, the sliding of the cutting tool 2 occurs without damage, the knife 25 not tearing off any reinforcing threads 6, 6', in particular when the knife 25 successively crosses the lateral edge 5_1 of the first reinforcing ply 5, and therefore the ends of the first reinforcing threads 6, then the lateral edge 5'_1 of the second reinforcing ply 5', and therefore the ends of the second reinforcing threads 6'.

[0263] Once the first hemisphere H1 has been machined, and therefore the first and second reinforcing plies exposed in said first hemisphere, as illustrated in FIGS. 6A, 6B, 6C, a second cutting sequence is carried out in the opposite hemisphere, here the second hemisphere H2 corresponding to the left hemisphere, by means of the second knife 25'.

[0264] According to this second cutting sequence, the direction of rotation of the support 20 is first reversed to obtain a positive direction of rotation R20+, then the axial movement of the second knife 25' is triggered, from a starting point K2 located in the trench 27, and in an axial direction of travel S2_2 of opposite sign to that used during the first cutting sequence, as illustrated in FIG. 7A.

[0265] The second cutting path T2_2 is advantageously the mirror image of the first cutting path T2_1 with respect to the equatorial plane P_EQ, and the adaptation of the direction of rotation R20+ allows the second cutting tool 2', which may possibly in turn be controlled by radial force, to slide in contact with the reinforcing wires 6, 6' while presenting itself in the correct direction with respect to the orientation of the reinforcing wires 6, 6', and thus to cross without damage to the reinforcing wires 6, 6' the second lateral edge 5_2 of the first reinforcing ply 5 then the second lateral edge 5'_2 of the second reinforcing ply 5' before reaching the second arrival point M2.

[0266] SECOND EXAMPLE

[0267] This second example begins in the same way as the first example.

[0268] On the other hand, once trench 27 has been dug and the implantation plan identified (Figures 5A, 5B), the second cutting sequence is performed in the second hemisphere H2 by the second knife 25' while, simultaneously, the first knife 25 performs the first cutting sequence in the first hemisphere H1, as illustrated in Figures 8A and 8B.

[0269] In fact, we use only one and the same direction of rotation of the support, here a negative direction R20-.

[0270] The first knife 25 runs along the first hemisphere H1 in contact with the reinforcing wires 6.

[0271] On the other hand, provision is made to offset the second knife 25' radially outwards, as can be seen in FIG. 8B, by a radial offset value Delta_T2, preferably between 1 mm and 3 mm, so that the second knife 25' leaves a residual excess thickness Delta_4 of the external layer and does not catch the reinforcing threads 6, 6' which it runs against the grain in the second hemisphere.

[0272] Where appropriate, as mentioned above, the radial offset value Delta_2 may be zero at the starting point K2 of the second cutting path T2_2, the second cutting tool 2' touching the reinforcing wires 6 at this second starting point K2, then increase progressively in order to radially move the cutting tool 2' away from the main axis Z20 as the cutting tool 2' moves away from the equatorial plane P_EQ and approaches the shoulder of the bandage 1, so as to reveal a residual excess thickness Delta_4 of the outer layer 4 between the cutting tool 2' and the reinforcing wires 6 at least when said cutting tool 2' axially crosses the end of said reinforcing wires 6, here directly above the second selvedge 5_2 of the first reinforcing ply 5, and even more so when said cutting tool 2' axially crosses the end of the second reinforcing wires 6' directly above the second edge 5'_2 of the second reinforcement layer 5'.

[0273] THIRD EXAMPLE

[0274] This time, the trench 27 shows a second implantation diagram as described above, and makes it possible to observe the presence of reinforcing wires 6 having an orientation A6 parallel or quasi-parallel to the equatorial plane P_EQ, typically having an angle A6_ang less than or equal, in absolute value, to 5 degrees, or even less than or equal to 3 degrees or even 2 degrees (figures 11A and 11B).

[0275] The machining can be carried out in one hemisphere H1 then the other hemisphere H2 sequentially, in which case the same knife 25 can be used for both cutting sequences or a first knife 25 for the first cutting sequence and a second knife 25' for the second cutting sequence. Advantageously, it is not necessary to reverse the direction of rotation R20+, R20- from one cutting sequence to the other.

[0276] As a variant, which makes it possible to minimize the cycle time, the two cutting sequences can be executed simultaneously, the first knife 25 being assigned to the first hemisphere H1, and the second knife 25' to the second hemisphere H2.

[0277] In all cases, it is advantageous to decide to machine the first hemisphere H1 as well as the second hemisphere H2 in contact with the reinforcing wires 6, as illustrated in FIG. 12A, and more particularly by positioning the cutting tools 2, 2' in accordance with a non-zero nominal value of deflection D_bend as described above.

[0278] Preferably, both the first cutting sequence and the second cutting sequence use a curved trajectory as shown in Figures 12A and 12B, and thus make it possible to collect the maximum amount of material available across the entire width of the bandage 1.

[0279] Of course, in the event that the reinforcing sheet 5 according to the second implantation diagram contains reinforcing threads 6 made of textile material, for example PET, precautions will be taken to prevent the knife 25, 25' from attacking said reinforcing threads 6 and mixing fragments of textile with the elastomer-based material, constituting the external layer 4, which it is desired to recover.

[0280] For example, once the radial position at which the reinforcing ply 5 is located has been detected, during the drilling operation by digging the trench 27, i.e. once the radial envelope distance D0_ply has been identified, it may be decided to apply, to each of the first and second cutting trajectories, a nominal value of deflection D_bend equal to zero, or even a safety radial offset, for example of the order of 1 mm to 3 mm, to ensure that, during the first and second cutting sequences, the knives 25, 25' are positioned at worst at the radial envelope distance D0_ply (which amounts to choosing a nominal value of deflection D_bend equal to zero), or more preferably in centrifugal radial withdrawal relative to the radial envelope distance (which amounts to choosing a non-zero safety radial offset), so that said knives 25, 25' remain slightly withdrawn radially outwards relative to the radial envelope distance. to the reinforcement layer 5.

[0281] Of course, the invention is in no way limited to the embodiment variants described above, 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.

Claims

Claims

1. Method for machining a tire (1), said tire (1) having a wall (3) which comprises at least one outer layer (4) based on elastomer and at least one reinforcing ply (5) which is located under said outer layer (4) and which contains a plurality of reinforcing threads (6) arranged according to an implantation pattern specific to the tire, said method comprising a material removal step during which at least one cutting sequence is executed according to which: - by means of a rotating support (20) having an axis of rotation called "main axis" (Z20), the tire (1) is driven in rotation on itself, around said main axis (Z20), in a chosen direction of rotation (R20+, R20-), - and, while the tire is driven in rotation (R20) on itself, a cutting path (T2_l, T2_l) is executed with a cutting tool (2),T2_2) which allows the cutting tool (2) to remove material from the outer layer (4) as said cutting tool (2) progresses along said cutting path (T2_l, T2_2), said method being characterized in that it comprises, prior to the material removal step:, - a step of analyzing the bandage during which at least part of the layout diagram is identified according to which the reinforcing wires (6) of the reinforcing ply (5) are arranged within the bandage (1) to be machined, - then a step of adapting the cutting sequence during which the cutting sequence is defined by adapting said cutting sequence according to at least one part of the implantation diagram which was identified during the bandage analysis step.

2. Method according to claim 1 characterized in that, during the cutting sequence, a cutting path (T2_l, T2_2) is executed with the cutting tool (2), while the bandage (1) is driven in rotation (R20) on itself in the desired direction of rotation (R20+, R20-), according to which said cutting tool (2) is made to travel, opposite the bandage, a predetermined axial range (W2_l, W2_2) considered along the main axis (Z20), called "axial cutting range" (W2_l, W2_2), in a direction called "axial travel direction" (S2_l, S2_2) predetermined, so that said cutting tool (2) removes material from said outer layer (4) in said axial cutting range (W2_l, W2_2) as said cutting tool (2) progresses along the main axis (Z20) in the axial travel direction (S2_l, S2_2), and in that, during the step of adapting the cutting sequence, the cutting sequence is defined by adapting, as a function of the at least one part of the layout diagram which has been identified during the step of analyzing the bandage, at least one, preferably at least two, and more preferably each of the following three parameters: i) the direction of rotation of the bandage (R20+, R20-), ii) the axial cutting range (W2_l, W2_2), iii) the axial travel direction (S2_l, S2_2) in which the cutting tool (2) is moved within the axial cutting range (W2_l, W2_2).

3. Method according to claim 1 or 2 characterized in that the step of analyzing the bandage is capable of identifying an implantation pattern according to which the reinforcing threads (6) extend parallel to each other within the reinforcing ply (5), and of identifying the orientation (A6) of said reinforcing threads (6) relative to a reference direction called "equatorial circumferential line" (L_EQ) which corresponds to the intersection of the radially external surface of the reinforcing ply (5) with a fictitious plane called "equatorial plane" (P_EQ) which is normal to the main axis (Z20) and which passes through the middle of the axial range (W1) occupied by the bandage (1).

4. Method according to claim 3 characterized in that, during the step of analyzing the bandage, a circumferential annular trench (27), called an "exploration trench" (27), is dug in the external layer (4), using the cutting tool (2), until the reinforcement ply (5) is reached, and the orientation (A6) of the reinforcement threads (6) is identified by observing the apparent surface of the reinforcement ply (5), which forms the bottom of the exploration trench (27), by means of an optical detection device (50).

5. Method according to claim 4 characterized in that the optical detection device (50) comprises: - a laser profilometer, arranged to measure by telemetry, on a predetermined angular sector around the main axis (Z20), the reliefs of the apparent surface of the reinforcing ply (5) which are due to the reinforcing threads (6), and / or - an image acquisition device, such as a camera, making it possible to take a photograph of the apparent surface of the reinforcing ply (5), and which is associated with an image processing unit.

6.

7. Method according to claim 2 and one of claims 3 to 5, characterized in that the cutting sequence is defined by choosing the direction of rotation (R20+, R20-) of the bandage, the axial cutting range (W2_l), and the axial travel direction (S2_l) such that: - the axial cutting range (W2_l) traveled by the cutting tool (2) extends axially from the abscissa of the equatorial plane (P_EQ) of the bandage to at least the axial abscissa of a first axial end (5_1) of the reinforcing ply (5) located axially away from the equatorial plane, - the cutting tool (2) moves in an axial direction of travel (S2_l) which goes from the equatorial plane towards said first axial end (5_1) of the reinforcement ply, - the relative displacement (V2) of the cutting tool (2) with respect to the reinforcing ply (5) has on the one hand a circumferential displacement component (V2_circ), induced by the rotation (R20) of the bandage, which has the same sign as the circumferential component (A6_circ) of the orientation (A6) of the reinforcing threads, considered when said reinforcing threads are traversed from the equatorial plane (P_EQ) towards the first axial end (5_1) of the reinforcing ply, and on the other hand an axial displacement component (V2_ax), which corresponds to the chosen axial direction of travel (S2_l), which axial displacement component (V2_ax) has the same sign as the axial component (A6_ax) of the orientation (A6) of the reinforcing threads (6), considered when said reinforcing threads (6) are traversed from the equatorial plane (P_EQ) towards the first axial end (5_1) of the ply reinforcement. Method according to one of claims 3 to 6, characterized in that, the wall (3) of the bandage (1) having a toroidal revolution shape, around the main axis (Z20), and the section of said wall (3), considered in a radial plane containing the main axis (Z20), having a shape that is generally curved towards the outside, the step of analyzing the bandage comprises a step of selecting the cutting trajectory during which, depending on the sign of the orientation (A6) of the reinforcing threads (6) relative to the equatorial circumferential direction (L_EQ), the following are chosen: - or, if the orientation (A6) of the reinforcing wires has a first sign, a cutting path (T2_l, T2_2) called “straight cutting path”, according to which the cutting tool (2) remains at a constant radial distance from the main axis (Z20) while said cutting tool (2) moves along said main axis (Z20), - or, if the orientation (A6) of the reinforcing wires (6) has a second sign opposite to the first sign, a cutting path (T2_l, T2_2) called a “curved cutting path”, according to which the radial distance of the cutting tool (2) is varied relative to the main axis (Z20), as the cutting tool (2) moves along said main axis (Z20), in order to give the cutting path a curvature which is of the same sign as the curvature presented by the wall (3), considered in the radial plane containing the main axis (Z20).

8. Method according to one of the preceding claims, characterized in that the cutting sequence provides a cutting path (T2_l, T2_2) which is such that, in at least a part of the external layer (4) crossed by said cutting path (T2_l, T2_2), the residual thickness (E4) of external layer (4) which the cutting tool (2) which executes said cutting path (T2_l, T2_2) leaves at most on the reinforcing wires (6) is less than or equal to 2 mm, preferably less than or equal to 1 mm, or even zero.

9. Method according to one of the preceding claims, characterized in that, during the cutting sequence, the cutting tool (2, 2') is brought into contact with the reinforcing ply (5), and while the cutting tool (2, 2') moves axially in a chosen axial cutting range (W2_l, W2_2), the cutting tool (2, 2') is controlled by radial force, for example by means of a pneumatic cylinder, so that said cutting tool (2, 2') slides in contact with the reinforcing ply (5), against the reinforcing wires (6).

10. Method according to one of the preceding claims, characterized in that, the bandage (1) extending axially, along the main axis, from a first axial end (1_1) to a second axial end (1_2), the material removal step comprises: - a first cutting sequence during which a cutting tool (2) travels, in a first axial direction of travel (S2_l), a first axial cutting range (W2_l) which extends from a first starting point (Kl) located axially between the first and second axial ends (1_1, 1_2) of the bandage, at a distance from each of the first and second axial ends of the bandage, preferably located at an axial position between 40% and 60% of the length of the axial range (Wl) between the first and second axial ends of the bandage, and more preferably located in the plane equatorial plane (P_EQ) which passes through the middle of the axial range (Wl) occupied by the bandage, up to a first arrival point (Ml) located at least at the axial abscissa of the first axial end (1_1) of the bandage, or even beyond said axial abscissa of the first axial end of the bandage, in the first axial direction of travel (S2_l), - then a second cutting sequence during which a cutting tool (2, 2') travels, in a second axial direction of travel (S2_2) opposite to the first axial direction of travel (S2_l), a second axial cutting range (W2_2), complementary to the first axial cutting range (W2_l), from a second starting point (K2) located in the first axial cutting range (W2_l), preferably at the same abscissa as the first starting point (Kl), and more preferably in the equatorial plane (P_EQ) of the bandage, up to a second arrival point (M2) located at least at the axial abscissa of the second axial end (1_2) of the bandage,or even beyond said axial abscissa of the second axial end (1_2) of the bandage, in the second axial direction of travel (S2_2).,

11. Method according to claim 10 characterized in that the first cutting sequence is executed by means of a first cutting tool (2), and the second cutting sequence is executed by means of a second cutting tool (2') distinct from the first cutting tool (2).

12. Method according to claim 10 or 11, characterized in that the first cutting sequence and the second cutting sequence are executed one after the other, and in that, at the end of the first cutting sequence, the direction of rotation (R20+, R20-) of the bandage (1) is reversed, so as to execute the second cutting sequence using a second direction of rotation (R20+) which is of opposite sign to the first direction of rotation (R20-) which was used during the first cutting sequence.

13. Method according to claim 10 or 11 characterized in that the first cutting sequence and the second cutting sequence are executed using the same direction of rotation (R20+, R20-), and more preferably are executed simultaneously, and in that the second cutting path (T2_2) which is applied during the second cutting sequence has a centrifugal radial offset (Delta_T2) relative to the first cutting path (T2_l) which is applied during the first cutting sequence, so as to preserve a residual excess thickness (Delta_4) of external layer (4) in the second axial cutting range (W2_2) relative to the first axial cutting range (W2_l).

14. Method according to one of the preceding claims, characterized in that the bandage (1) has a first annular heel (7) and a second annular heel (8), provided respectively with a first bead wire and a second bead wire, in that the wall (3) of the bandage forms a radially external crown (10), as well as a first flank (11) which connects said crown (10) to the first heel (7) and a second flank (12) which connects the crown (10) to the second heel (8), and in that the rotating support (20) is arranged to hold the bandage (1), preferably not inflated, by the first heel (7) and second heel (8), while leaving the crown (10) free.

15. Method according to one of the preceding claims, characterized in that, during the bandage analysis step, it is identified, at a given axial abscissa, which preferably corresponds to the abscissa of the starting point (Kl, K2) of the cutting path (T2_l, T2_2), at what radial distance from the main axis (Z20), called "radial envelope distance" (D0_ply), the radially external limit of the reinforcing wires (6) of the reinforcing ply (5) located at said given abscissa, then, during the cutting path adaptation step, the cutting path (T2_l, T2_2) is defined in such a way that said cutting path brings the cutting tool (2), when the latter is at the given abscissa, to a radial distance from the main axis (Z20) which is strictly less than the radial envelope distance (D0_ply) of a value called “nominal deflection value” (D_bend),for example less than the radial envelope distance (D0_ply ) by a value called the “nominal deflection value” (D_bend ) of between 2 mm and 5 mm, more preferably equal to 3 mm, so as to cause radial depression of the wall (3) by elastic deformation in bending of the reinforcing wires (6), and thus create a prestress in radial compression of the cutting tool (2) against the external layer (4) supported by the reinforcing wires (6).,

16. Installation (40) intended to machine a bandage (1), said bandage (1) having a wall (3) which comprises at least one external layer (4) based on elastomer, preferably based on vulcanized rubber, and at least one reinforcing ply (5), which is located under said external layer (4) and which contains a plurality of reinforcing threads (6) arranged according to an implantation pattern specific to the bandage, said installation including: - a rotary support (20) which is arranged to receive the bandage, which rotary support is mounted in rotation on a frame (30) around a main axis (Z20) and associated with a drive system (41) which makes it possible to drive said rotary support (20), and therefore the bandage (1), in rotation (R20) on itself around said main axis (Z20), - at least one cutting tool (2, 2'), - a positioning system (42, 42') which allows the cutting tool (2, 2') to be moved relative to the frame (30) and the rotating support (20), while the rotating support (20) carrying the bandage is driven in rotation (R20), so as to cause the cutting tool (2, 2') to execute a cutting path (T2_l, T2_2) which allows the cutting tool to remove material from the outer layer (4) as said cutting tool progresses along said cutting path, - a control unit (52) arranged to control the drive system (41) and the positioning system (42) in order to implement the rotation of the support (20) and the cutting trajectory (T2_l, T2_2) of the cutting tool according to a predefined cutting sequence, said installation being characterized in that it comprises: - a system (53) for analyzing the bandage arranged to identify at least one part of the implantation diagram according to which the reinforcing wires (6) of the reinforcing ply (5) are arranged within the bandage (1) to be machined, - and a unit (54) for adapting the cutting sequence which is arranged to define the cutting sequence which will be applied by the control unit (52) by adapting said cutting sequence according to the at least one part of the implantation diagram which has been identified by the system (53) for analyzing the bandage.

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