Multi-strand cable with a multi-strand layer

Abstract

The invention relates to a multi-strand cable with a multi-strand layer of structure 1 x X comprising a single layer (51) of X helically wound multi-strands (M1), each multi-strand (M1) comprising K > 1 strands (T1) helically wound around a main axis (A), each strand (T1) being a strand with at least two layers (C1, C3), with the strands (T1) being helically wound around an axis (A'). The cable (50) has an endurance criterion V1 = Δσ bending (M / D) < 3500 N x m / g. The cable (50) has a structural elongation As such that As ≥ 1.0%.

Description

Single-layer multi-strand cable

[0001] The invention relates to cables and a pneumatic system comprising these cables.

[0002] Cables with a 1xN structure, as described in document WO2016 / 131862, are known from the prior art. These cables comprise a single layer of N=4 strands wound helically with a pitch p3=20 mm. Each strand consists of an inner layer of 3 inner wires wound helically with a pitch p1=6.7 mm and an outer layer of 8 outer wires wound helically around the inner layer with a pitch p2=10 mm. The structural elongation of the cable is 2.8%, the cable diameter is 3.8 mm, the linear density is 36.4 g / m, and the endurance criterion is 3635 N x m / g.

[0003] These cables have the advantage of possessing a relatively high structural elongation, but the endurance criterion could be improved to increase the endurance of the reinforcements while reducing shear in the polymer matrix.

[0004] Today, a need is emerging for the development of new cables for applications in apex plies, particularly zero-degree plies such as apex plies for shrink-fitting. These plies are designed to shrink-fit the tire, thereby reducing shear stress at the plies' edges and decreasing the rigidity of the apex block at the center against stresses.

[0005] The invention aims at a cable which has sufficient flexibility and structural elongation to allow the shaping of the tire and reduce the rigidity of the top block, with an improved endurance criterion to withstand cyclic tensile stresses.

[0006] To this end, the invention relates to a multi-strand cable with a single layer of multi-strands in which the 1xX structural cable comprises a single layer of X multi-strands wound helically around a main axis, each multi-strand comprising K>1 strands, each strand having at least two layers comprising: - an inner layer consisting of Q1 internal metallic wire(s) of diameter d1, and - an outer layer consisting of Q3 external metal wires of diameter d3 wound around the inner layer, with the strands being wound helically around an axis, the cable (50) has an endurance criterion V1 = Bending / (M / D) < 3500 N xm / g; with - ^flexure = M steel x Max ^ e n MPa.mm is the maximum bending stress per unit curvature seen by the internal and external wires of the strands with di being the diameter of the metal wires and i ranging from 1 to 3 and with Macier = 200,000 MPa; - M is the linear mass in g / m of the cable, M being the sum of the metal sections of all the metal wires of the cable multiplied by the density of steel Ro with Ro= 7.79 g / cm3; -D is the diameter of the cable (50) in mm and; in which the cable has a structural elongation As such that As > 1.0%, the structural elongation As being determined according to ASTM D2969-04 of 2014 to the cable so as to obtain a force-elongation curve, the structural elongation As being equal to the elongation, in %, corresponding to the intersection between the tangent to the elastic part of the force-elongation curve at any point in its elastic part and the axis of elongations of the force-elongation curve.

[0007] Thanks to this multi-strand cable configuration with a single layer of multi-strands, the cable according to the invention makes it possible to obtain a cable with sufficient metal mass while keeping thin wires allowing to achieve increased endurance performance and thus improve the compromise between shear in the polymer matrix and the endurance holding of the reinforcement and improve the cleavage performance.

[0008] On the one hand, thanks to its relatively low endurance criterion, the cable according to the invention makes it possible to reduce stress levels in the cable subjected to tensile stress and thus extend the tire's lifespan. Indeed, the inventors of the invention discovered that the primary determining criterion for improving the endurance performance of a cable in a corrosive environment was not solely the breaking strength, as is widely taught in the prior art, but the endurance criterion represented in this application by an indicator equal to a combination of bending stress, cable diameter, and cable metal mass: - the bending stress per unit curvature seen by the inner and outer wires of the strands: Ao -( eXiOnbeing the maximum bending stress per unit curvature seen by the metal wires, on this type of cable, the inventors of the invention discovered that the tension stress on the cable generated at the same time tension and bending stresses at the scale of the unit wires; thus the reduction of this bending stress criterion is therefore positive for the tension endurance performance of the cable by relieving the part due to bending; - the metal mass of the cable on the diameter of the cable which, by increasing it, mainly relieves the tensile stresses of the cable: with M being the linear mass of the cable in g / m which can be defined in a simplified way by the sum of the metal mass of all the unit wires of the cable multiplied by the density of steel Ro= 7.79 g / cm3 with the sum of the sections being determined by image processing on a cross-section of the cable and ; with the diameter of the cable D is measured on the cable according to the ASTM D2969-04 standard.

[0009] By definition, the diameter of the cable is the diameter of the smallest circle in which the cable is circumscribed without the ferrule.

[0010] The structural elongation As, a quantity well known to those skilled in the art, is determined For example, by applying the 2014 ASTM D2969-04 standard to a tested cable to obtain a force-stretch curve. The As on the resulting curve is deduced as the elongation, expressed as a percentage, corresponding to the intersection between the tangent to the elastic portion of the force-stretch curve and the elongation axis of the force-stretch curve. As a reminder, a force-stretch curve comprises, as we move towards increasing elongations, a structural portion, an elastic portion, and a plastic portion. The structural portion corresponds to the structural elongation of the cable resulting from the coming together of the various strands and metal wires constituting the cable. The elastic portion corresponds to the elastic elongation resulting from the cable's construction, particularly the angles of the different layers and the diameters of the metal wires.The plastic part corresponds to the plastic elongation resulting from the plasticity (irreversible deformation beyond the elastic limit) of the metal wires.

[0011] In the invention, the cable comprises a single layer of X multi-strands, that is to say, it comprises an assembly consisting of one layer of multi-strands, no more and no less, that is to say, the assembly has one layer of multi-strands, not zero, not two, but only one.

[0012] Advantageously, each strand has cylindrical layers. Recall that such cylindrical layers are obtained when the different layers of strands are wound at different pitches and / or when the winding directions of these layers differ from one layer to another. A strand with cylindrical layers is highly penetrable, unlike a strand with compact layers, in which the pitch of all layers is equal and the winding directions of all layers are identical, which exhibits much lower penetrability.

[0013] Advantageously, each strand is desaturated, meaning there is a space between the outer layer threads, allowing the elastomeric composition to impregnate each strand.

[0014] Advantageously, each strand in the multi-strand is double-layered, meaning it comprises an assembly of two layers of metal wire, no more and no less; that is, the assembly has two layers of metal wire, not one, not three, but only two. The outer layer of each strand is wound around the inner layer of that strand, in contact with the inner layer of that strand.

[0015] Preferably, the strands do not undergo pre-formation.

[0016] The cable as defined above and according to the invention is bare, that is to say, devoid of any polymeric composition, in particular the cable is devoid of any elastomeric composition.

[0017] By metallic wire, we mean a metallic monofilament comprising a core made up mainly (i.e., for more than 50% of its mass) or entirely (for 100% of its mass) of a metallic material, for example carbon steel. The wire may advantageously include a layer of a metallic coating covering the core, the metallic coating being selected from zinc, copper, tin, and alloys of these metals, for example brass. Each wire is preferably made of pearlitic or ferritic-pearlitic carbon steel.

[0018] The values ​​of the characteristics described in this application for the bare cable are measured on or determined from the cables directly after manufacture, i.e. before any embedding step in a polymeric matrix, in particular an elastomeric one.

[0019] In this application, any range of values ​​designated by the expression "between a and b" represents the range of values ​​from more than a to less than b (i.e., excluding bounds a and b) while any range of values ​​designated by the expression "from a to b" means the range of values ​​from the bound "a" to the bound "b", i.e., including the strict bounds "a" and "b".

[0020] Advantageously, As > 1.5% and preferably As > 2.0%.

[0021] The invention also relates to a cable extracted from a polymer matrix, the extracted cable comprising a single layer of X multi-strands wound helically around a main axis, each multi-strand comprising K>1 strands, each strand having at least two layers comprising: - an inner layer consisting of Q1 internal metallic wire(s) of diameter d1, and - an outer layer consisting of Q3 external metallic wires of diameter d3 wound around the inner layer, with the strands being wound helically around an axis, in which the cable has an endurance criterion V1 = ^Ofi eX ion / (M / D) < 4000 N xm / g; with - Deflection = M steel x Max ^ e n MPa.mm is the maximum bending stress per unit curvature seen by the internal and external wires of the strands with di being the diameter of the metal wires and i ranging from 1 to 3 and with Macier = 200,000 MPa; - M is the linear mass in g / m of the cable, M being the sum of the metal sections of all the metal wires of the cable multiplied by the density of steel Ro with Ro= 7.79 g / cm3; -D is the diameter of the cable in mm; the extracted cable has a structural elongation As' such that As' > 0.3%, the structural elongation As' being determined according to ASTM D2969-04 of 2014 to the cable so as to obtain a force-elongation curve, the structural elongation As' being equal to the elongation, in %, corresponding to the intersection between the tangent to the elastic part of the force-elongation curve at any point of its elastic part and the axis of elongations of the force-elongation curve.

[0022] Preferably, the polymer matrix is ​​an elastomeric matrix.

[0023] The polymeric matrix, preferably elastomeric, is based on a polymeric composition, preferably elastomeric.

[0024] A polymer matrix is ​​defined as a matrix comprising at least one polymer. The polymer matrix is ​​thus based on a polymer composition.

[0025] An elastomeric matrix is ​​defined as a matrix comprising at least one elastomer. The preferred elastomeric matrix is ​​thus based on the elastomeric composition.

[0026] The expression "based on" means that the composition includes the mixture and / or the in situ reaction product of the different constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, during the different phases of manufacturing the composition; the composition can thus be in a totally or partially crosslinked state or in a non-crosslinked state.

[0027] By polymeric composition, we mean that the composition comprises at least one polymer. Preferably, such a polymer can be a thermoplastic, for example a polyester or a polyamide, a thermosetting polymer, an elastomer, for example natural rubber, a thermoplastic elastomer or a mixture of these polymers.

[0028] An elastomeric composition is defined as a composition comprising at least one elastomer and at least one other component. Preferably, a composition comprising at least one elastomer and at least one other component includes an elastomer, a crosslinking system, and a filler. Suitable compositions for these webs are conventional compositions for calendering reinforcing wire elements and include a diene elastomer, for example, natural rubber; a reinforcing filler, for example, carbon black and / or silica; a crosslinking system, for example, a vulcanizing system, preferably comprising sulfur, stearic acid, and zinc oxide; and optionally, a vulcanization accelerator and / or retarder and / or various additives. Adhesion between the metal wires and the matrix in which they are embedded is ensured, for example, by a metallic coating, such as a layer of brass.

[0029] The values ​​of the characteristics described in this application for the extracted cable are measured on, or determined from, cables extracted from a polymer matrix, particularly an elastomeric one, for example, from a tire. Thus, for example, on a tire, the strip of material is removed radially on the outside of the cable to be extracted so that the cable to be extracted is visible radially protruding from the polymer matrix. This removal can be done by peeling with pliers and knives or by planing. Then, the end of the cable to be extracted is freed with a knife. Next, the cable is pulled out of the matrix at a relatively shallow angle so as not to plasticize the cable. The extracted cables are then cleaned. carefully, for example using a knife, so as to detach the remnants of polymer matrix attached locally to the cable and taking care not to degrade the surface of the metal wires.

[0030] To determine the linear mass of the extracted cable, a cross-section of the cable is performed in the elastomeric matrix, determining the steel surface area by image processing and multiplying by the density of the steel.

[0031] To measure the linear mass of the extracted cable, one can also, following the operation described above, weigh one meter of cleaned cable to determine the average linear mass of cleaned cable over 10 measurements.

[0032] The advantageous characteristics described below apply equally to bare cable and to cable extracted from a polymer matrix.

[0033] Advantageously, criterion V1 is greater than or equal to 1000 N xm / g, preferably greater than or equal to 1500 N xm / g.

[0034] Advantageously, criterion V1 is less than or equal to 3000 N xm / g.

[0035] Advantageously, the linear mass M ranges from 15 to 75 g / m, preferably from 25 to 65 g / m.

[0036] Preferably, the cable has a cable diameter such that the cable diameter D ranges from 3 mm to 7 mm, preferably from 3.5 mm to 6 mm.

[0037] By definition, the diameter of a strand is the diameter of the smallest circle in which the strand is circumscribed.

[0038] Preferably, the diameters of the metal wires range independently from 0.15 mm to 0.50 mm, preferably from 0.18 mm to 0.35 mm and more preferably from 0.20 mm to 0.30 mm.

[0039] Preferably, the wires in the same layer of a predetermined strand all have substantially the same diameter. Advantageously, the strands all have substantially the same diameter. By "substantially the same diameter," we mean that the wires or strands have the same diameter within industry tolerances.

[0040] Advantageously, X is equal to 3 or 4, preferably X=4.

[0041] Advantageously, K= 2, 3 or 4, preferably K=3 or 4.

[0042] In a first embodiment, each strand has two layers.

[0043] In a second embodiment, each strand has three layers and comprises: an intermediate layer consisting of Q2 intermediate metal wires wound around the inner layer, and an outer layer consisting of Q3 external metal wires wound around the intermediate layer.

[0044] Advantageously, each strand is of the non-gummed in situ type. By non-gummed in situ, we mean that before the strands are joined together, each strand consists of the threads of the different layers and devoid of polymeric composition, in particular of elastomeric composition.

[0045] Strands of the multi-strands of the cable according to the invention

[0046] Advantageously, in this first embodiment, in a preferred variant, Q1=1, 2, 3 or 4, preferably Q1=1, 2 or 3 and more preferably Q1=1 or 3.

[0047] Advantageously, in this first embodiment, in a preferred variant, Q3 = 5, 6, 7, 8, 9 or 10, preferably Q3 = 6, 7, 8 or 9 and more preferably Q3 = 6 or 9.

[0048] In a variant of this first embodiment, Q1 = 1.

[0049] Advantageously, Q3 = 5, 6 or 7 and preferably Q3 = 6.

[0050] In another variant of this first preferred embodiment, Q1 > 1, preferably Q1 = 2, 3 or 4.

[0051] Advantageously, Q3 = 7, 8, 9 or 10 and preferably Q3 = 7, 8 or 9.

[0052] In a first variant, Q1=2 and Q3=7 or 8, preferably Q1=2, Q3=7.

[0053] In a second variant, Q1=3 and Q3=7, 8 or 9, preferably Q1=3, Q3=8.

[0054] In a third variant, Q1=4 and Q3=7, 8, 9 or 10, preferably Q1=4, Q3=9.

[0055] In a highly preferential manner, for each strand, Q1=1 and Q3=6.

[0056] REINFORCED PRODUCT ACCORDING TO THE INVENTION

[0057] Another object of the invention is a reinforced product comprising a polymer matrix and at least one cable or extracted cable as defined above.

[0058] Advantageously, the reinforced product comprises one or more cables according to the invention embedded in the polymer matrix, and in the case of several cables, the cables are arranged side by side along a main direction.

[0059] PNEUMATIC ACCORDING TO THE INVENTION

[0060] Another object of the invention is a tire comprising at least one extracted cable or a reinforced product as defined above.

[0061] By pneumatic including an extracted cable, we mean a pneumatic including a cable whose properties, measured after extraction of the pneumatic, are those of the extracted cable, this cable being, prior to its incorporation into the pneumatic, a cable such as the cable described previously.

[0062] Preferably, the tire comprises a carcass reinforcement anchored in two beads and radially surmounted by a crown reinforcement itself surmounted by a tread, the crown reinforcement being joined to said beads by two sidewalls and comprising at least one cord as defined above.

[0063] In a preferred embodiment, the top reinforcement comprises a protective reinforcement, a working reinforcement, and a reinforcing reinforcement comprising at least one cable as defined above, the protective reinforcement being radially interposed between the tread and the working reinforcement, and the reinforcing reinforcement being preferably sandwiched between the two layers of working reinforcement.

[0064] The cable is particularly intended for industrial vehicles chosen from among heavy vehicles such as "Heavy Goods Vehicles" - i.e., metro, bus, road transport vehicles (trucks, tractors, trailers), off-road vehicles -, agricultural or civil engineering vehicles, other transport or handling vehicles.

[0065] Preferably, the tire is for construction equipment type vehicles. Thus, the tire has a dimension in which the diameter, in inches, of the rim seat on which the tire is intended to be mounted is greater than or equal to 40 inches.

[0066] The invention also relates to a rubber article comprising an assembly according to the invention, or an impregnated assembly according to the invention. A rubber article is understood to mean any type of rubber article such as a balloon, a non-pneumatic object such as a non-pneumatic bandage, a conveyor belt, or a track. The invention will be better understood upon reading the following examples, given solely as non-limiting examples and made with reference to the drawings in which: - Figure 1 is a cross-sectional view perpendicular to the circumferential direction of a tire according to the invention; - Figure 2 is a detailed view of area II of figure 1; - Figure 3 is a cross-sectional view of a reinforced product according to the invention; - Figure 4 is a schematic cross-sectional view perpendicular to the axis of the cable (assumed to be straight and at rest) of a cable (50) according to a first embodiment of the invention; - Figure 5 is a schematic cross-sectional view perpendicular to the cable axis (assumed to be straight and at rest) of an extracted cable (50') according to a first embodiment of the invention; and - Figure 6 is a view similar to that of Figure 4 of a cable (60) according to a second embodiment of the invention.

[0067] EXAMPLE OF A PNEUMATIC TIRE ACCORDING TO THE INVENTION

[0068] Figures 1 and 2 show an X, Y, Z coordinate system corresponding to the usual axial (X), radial (Y) and circumferential (Z) orientations of a tire.

[0069] The "circumferential median plane" M of the tire is the plane that is normal to the axis of rotation of the tire and that is equidistant from the annular reinforcement structures of each bead.

[0070] Figures 1 and 2 show a tire according to the invention and designated by the general reference 10.

[0071] The 10-inch tire is for heavy-duty vehicles such as construction equipment, for example, of the type "dumper". Thus, tire 10 has a size of type 53 / 80R63.

[0072] The tire 10 comprises a crown 12 reinforced by a crown reinforcement 14, two sidewalls 16, and two bead 18, each bead 18 being reinforced with an annular structure, here a bead 20. The crown reinforcement 14 is radially surmounted by a tread 22 and joined to the bead 18 by the sidewalls 16. A carcass reinforcement 24 is anchored in the two bead 18 and is here wrapped around the two beads 20. It includes a gusset 26 facing outwards from the tire 20, which is shown here mounted on a rim 28. The carcass reinforcement 24 is radially surmounted by the crown reinforcement 14.

[0073] The carcass reinforcement 24 comprises at least one carcass layer 30 reinforced by radial carcass cables (not shown). The carcass cables are arranged substantially parallel to each other and extend from one bead 18 to the other so as to form an angle between 80° and 90° with the median circumferential plane M (plane perpendicular to the axis of rotation of the tire which is located midway between the two bead 18 and passes through the middle of the apex reinforcement 14).

[0074] The tire 10 also includes a sealing layer 32 made of an elastomer (commonly called inner rubber) which defines the radially inner face 34 of the tire 10 and which is intended to protect the carcass layer 30 from air diffusion from the space inside the tire 10.

[0075] The crown reinforcement 14 comprises, radially from the outside to the inside of the tire 10, a protective reinforcement 36 arranged radially inside the tread 22, a working reinforcement 38 arranged radially inside the protective reinforcement 36 and a reinforcing reinforcement 40 radially interposed between the two plies 48, 46 of the working reinforcement 38. The protective reinforcement 36 is thus radially interposed between the tread 22 and the working reinforcement 38.

[0076] The protective frame 36 comprises first and second protective layers 42, 44 comprising protective metal cables, the first layer 42 being arranged radially inside the second layer 44. Optionally, the protective metal cables make an angle of at least 10°, preferably from 10° to 35° and preferably from 15° to 35° with the circumferential direction Z of the tire.

[0077] The working frame 38 comprises first and second working layers 46, 48, the first layer 46 being arranged radially inside the second layer 48.

[0078] The shrink-fit armature 40, also called the limiting block, includes at least one cable 50 making an angle of no more than 10°, preferably from 0° to 5° with the circumferential direction Z of the tire 10.

[0079] EXAMPLE OF A REINFORCED PRODUCT ACCORDING TO THE INVENTION

[0080] Figure 3 shows a reinforced product according to the invention and designated by the general reference 100. The reinforced product 100 comprises at least one cable 50, in this case several cables 50, embedded in the polymer matrix 102.

[0081] Figure 3 shows the polymer matrix 102 and the cables 50 in an X, Y, Z coordinate system where the Y direction is the radial direction and the X and Z directions are the axial and circumferential directions, respectively. In Figure 3, the reinforced product 100 comprises several cables 50 arranged side by side along the principal X direction, extending parallel to each other within the reinforced product 100 and collectively embedded in the polymer matrix 102. Here, the polymeric matrix 102 is an elastomeric matrix based on an elastomeric composition.

[0082] CABLE ACCORDING TO A FIRST EMBODIMENT OF THE INVENTION

[0083] Figure 4 shows cable 50 according to a first embodiment of the invention.

[0084] Referring to Figure 5, each marginal reinforcement element is formed, after extraction of the tire 10, by an extracted cable 50' as described below. The cable 50 is obtained by embedding it in a polymer matrix, in this case in a polymer matrix forming the polymer matrix of each working layer.

[0085] The 50 cable and the 50' extracted cable are metallic and of the multi-strand type with a single cylindrical layer. Thus, it is understood that the layers of multi-strands constituting the 50 or 50' cable are one in number, no more, no less.

[0086] At least 50% of the metal wires, preferably at least 60%, more preferably at least 70% of the metal wires, and most preferably each metal wire of the cable comprises a steel core having a composition conforming to standard NF EN 10020 of September 2000 and a carbon content C > 0.80% and preferably C > 0.82%, and at least 50% of the metal wires, preferably at least 60%, more preferably at least 70% of the metal wires, and most preferably each metal wire of the cable comprises a steel core having a composition conforming to standard NF EN 10020 of September 2000 and a carbon content C < 1.20% and preferably C < 1.10%. Here, each metal wire comprises a steel core having a composition conforming to standard NF EN 10020 of September 2000 and a carbon content C = 0.86%.

[0087] Each wire has a tensile strength, denoted Rm, such that 2500 < Rm < 3100 MPa. The steel used for these wires is said to be SHT grade ("Super High Tensile"). Other wires can be used, for example, lower grade wires, such as NT grade ("Normal Tensile") or HT grade ("High Tensile"), as well as higher grade wires, such as UT grade ("Ultra Tensile") or MT grade ("Mega Tensile").

[0088] METHOD FOR MANUFACTURING THE CABLE ACCORDING TO THE INVENTION

[0089] We will now describe an example of a manufacturing process for multi-strand cable with 50 strands.

[0090] Each T1 strand described above is manufactured according to known processes comprising the following steps, preferably carried out in-line and continuously: - firstly, a first assembly step by wiring or twisting the 6 external wires F3 around the internal wire F1 of the internal layer C1 at a pitch of p3 and in the direction S to form the external layer C3 at a first assembly point; - preferably a final torsion balancing step.

[0091] By "torsional balancing", we mean here, in a way well known to those skilled in the art, the cancellation of residual torsional couples (or elastic torsional return) acting on each wire of the strand, in the outer layer.

[0092] After this final twist balancing stage, the strand manufacturing process is complete. Each strand is wound onto one or more receiving reels for storage before the subsequent assembly operation by wiring the individual strands to obtain the multi-strand cable.

[0093] For the manufacture of the multi-strands of the invention, the process is carried out in a manner well known to those skilled in the art, by twisting the strands previously obtained, using twisting machines sized to assemble strands.

[0094] In a manufacturing step of the multi-strand M1 of layer 51, the K=3 internal strands T1 are assembled by twisting at the pitch P1 and in the direction S to form the multi-strand M1 of layer 51 at a first assembly point.

[0095] Then, in a subsequent manufacturing step, the X=4 multi-strand M1s are assembled by wiring at a pitch pe and in the S direction to form a multi-strand cable of multi-strands. Optionally, in a final assembly step, the ferrule F is wound at a pitch pf in the Z direction around the assembly previously obtained.

[0096] The 50 cable is then incorporated by calendering into composite fabrics made of a known composition based on natural rubber and carbon black as a reinforcing filler, conventionally used for manufacturing the crown reinforcements of radial tires. This composition essentially comprises, in addition to the elastomer and the reinforcing filler (carbon black), an antioxidant, stearic acid, an expanding oil, cobalt naphthenate as an adhesion promoter, and finally a vulcanization system (sulfur, accelerator, ZnO).

[0097] The composite fabrics reinforced by these cables comprise an elastomeric matrix made up of two thin layers of elastomeric composition superimposed on either side of the cables, with thicknesses ranging from 1 to 4 mm respectively. The calendering pitch (the pitch of the cables in the fabric) (elastomeric composition) ranges from 4 mm to 8 mm.

[0098] These composite fabrics are then used as a working layer in the crown reinforcement during the tire manufacturing process, the steps of which are otherwise known to those skilled in the art.

[0099] CABLE ACCORDING TO A SECOND EMBODIMENT OF THE INVENTION

[0100] Figure 6 shows a cable 60 according to a second embodiment of the invention.

[0101] Unlike the first embodiment described above, cable 60 according to the second embodiment is such that Q1= 1; Q2= 5 and Q3= 10.

[0102] Table 1 below summarizes the characteristics for the different 50, 50' and 60 cables.

[0103] [Table 1]

[0104] Table 2 below summarizes the characteristics for the cable of the state of the art described in document WO2016 / 131862.

[0105] [Table 2] ;0106] It is observed that the 50, 50' and 60 cables according to the invention make it possible to obtain a cable exhibiting sufficient flexibility and structural elongation to allow the shaping of the tire and reduce the rigidity of the top block, with an improved endurance criterion to withstand cyclic tensile stresses compared to the cable of the prior art.

[0107] The invention is not limited to the embodiments described above.

Claims

DEMANDS 1. A single-layer multi-strand cable (50) characterized in that the 1xX structural cable comprises a single layer (51) of X multi-strands (M1) wound helically around a main axis (A), each multi-strand (M1) comprising K>1 strands (T1), each strand (T1) being of at least two layers (C1, C3) comprising: - an inner layer (C1) consisting of Q1 internal metallic wire(s) (F1) of diameter d1, and - an outer layer (C3) consisting of Q3 external metal wires (F3) of diameter d3 wound around the inner layer (C1), with the strands (T1) being wound helically around an axis (A), the cable (50) has an endurance criterion V1 = Bending / (M / D) < 3500 N xm / g; with - Deflection = M steel x Max ^ en MPa.mm is the maximum bending stress per unit curvature seen by the internal and external wires of the strands with di being the diameter of the metal wires and i ranging from 1 to 3 and with Macier = 200,000 MPa; - M is the linear mass in g / m of the cable (50), M being the sum of the metal sections of all the metal wires of the cable multiplied by the density of steel Ro with Ro= 7.79 g / cm3; -D is the diameter of the cable (50) in mm and ; in which the cable (50) has a structural elongation As such that As > 1.0%, the structural elongation As being determined according to ASTM D2969-04 of 2014 to the cable (50) so as to obtain a force-elongation curve, the structural elongation As being equal to the elongation, in %, corresponding to the intersection between the tangent to the elastic part of the force-elongation curve at any point of its elastic part and the axis of elongations of the force-elongation curve.

2. Cable (50) according to the preceding claim, wherein As > 1.5% and preferably As > 2%.

3. A single-layer multi-strand cable (50') of 1x X structure extracted from a polymer matrix (102), characterized in that the extracted cable (50') comprises a single layer (51) of X multi-strands (M1) wound helically around a main axis (A), each multi-strand (M1) comprising K>1 strands (T1), each strand (T1) having at least two layers (C1, C3) comprising: - an inner layer (C1) consisting of Q1 internal metallic wire(s) (F1) of diameter d1, and - an outer layer (C3) consisting of Q3 external metallic wires (F3) of diameter d3 wound around the inner layer (C1), with the strands (T1) being wound helically around an axis (A), characterized in that the extracted cable (50') has an endurance criterion V1 = ^Ofi eX ion / (M / D) < 3500 N xm / g; with - Deflection = M steel x Max ^ e n MPa.mm is the maximum bending stress per unit curvature seen by the internal and external wires of the strands with di being the diameter of the metal wires and i ranging from 1 to 3 and with Macier = 200,000 MPa; - M is the linear mass in g / m of the cable (50'), M being the sum of the metal sections of all the metal wires of the cable multiplied by the density of steel Ro with Ro= 7.79 g / cm3; -D is the diameter of the cable (50') in mm; the extracted cable (50') has a structural elongation As' such that As' > 0.3%, the structural elongation As' being determined according to ASTM D2969-04 of 2014 on the cable (50') so as to obtain a force-elongation curve, the structural elongation As' being equal to the elongation, in %, corresponding to the intersection between the tangent to the elastic part of the force-elongation curve at any point in its elastic part and the axis of elongations of the force-elongation curve.

4. Cable (50; 50') according to any one of the preceding claims, wherein criterion V1 is greater than or equal to 1000 N xm / g, preferably greater than or equal to 1500 N xm / g.

5. Cable (50; 50') according to any one of the preceding claims, wherein criterion V1 is less than or equal to 3000 N xm / g.

6. Cable (50; 50') according to any one of the preceding claims, wherein the linear mass M ranges from 15 to 75 g / m, preferably from 25 to 65 g / m.

7. Cable (50; 50') according to any one of the preceding claims, wherein the diameter D of the cable ranges from 3 mm to 7 mm, preferably from 3.5 mm to 6 mm.

8. Cable (50; 50') according to any one of the preceding claims, in which the diameters of the metal wires (F1; F3) range independently from 0.15 mm to 0.50 mm, preferably from 0.18 mm to 0.35 mm and more preferably from 0.20 mm to 0.30 mm.

9. Cable (50; 50') according to any one of the preceding claims, wherein X is equal to 3 or 4, preferably X=4.

10. Cable (50; 50') according to any one of the preceding claims, wherein K= 2, 3 or 4, preferably K=3 or 4.

11. Cable (50; 50') according to any one of the preceding claims, wherein each strand (T1) is two-layered (C1, C3).

12. Cable (50; 50') according to any one of the preceding claims, in which Q1=1, 2, 3 or 4, preferably Q1=1, 2 or 3 and more preferably Q1=1 or 3.

13. Cable (50; 50') according to any one of the preceding claims; wherein Q3 = 5, 6, 7, 8, 9 or 10, preferably Q3 = 6, 8 or 9 and more preferably Q3 = 6 or 9.

14. Reinforced product (100), characterized in that it comprises a polymer matrix (102) and at least one cable (50') such that the properties of this cable, measured after extraction, are those of the extracted cable (50') according to any one of claims 3 to 13.

15. Pneumatic (10), characterized in that it comprises at least one cable (50') such that the properties of this cable, measured after extraction from the pneumatic, are those of the extracted cable (50') according to any one of claims 3 to 13 or a reinforced product according to claim 14.

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