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EP-4739835-A1 - MULTI-STRAND CABLE WITH TWO MULTI-STRAND LAYERS

EP4739835A1EP 4739835 A1EP4739835 A1EP 4739835A1EP-4739835-A1

Abstract

The invention relates to a multi-strand cable (50) with two multi-strand layers, the cable (50) comprising: - a cable inner layer (CI) made up of X = 1 multi-strand (M1) that has a diameter DM1 and comprises K > 1 strands (T1) helically wound about a main axis (A), each strand (T1) having at least two layers (C1, C3), with the strands (T1) being helically wound about an axis (B); and - a cable outer layer (CE) made up of Y > 1 multi-strands (M2) that have a diameter DM2 and are wound about the cable inner layer (CI), each multi-strand (M2) comprising L > 1 strands (T2) helically wound about a main axis (A'), each strand (T2) having at least two layers (C1'; C3'), with the multi-strands (T2) being helically wound about the main axis (A). The cable (50) has a structural elongation As such that As ≥ 1.0%, and has a saturation ratio π x (DM1+DM2)/( Y x DM2) greater than or equal to 1.11.

Inventors

  • LAURENT, Stéphane
  • BARBAT, Romain
  • CHEVALLEY, Marianna
  • GIANETTI, Alexandre
  • PINAUT, Rémi

Assignees

  • COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN

Dates

Publication Date
20260513
Application Date
20240613

Claims (15)

  1. 1. Multi-strand cable (50) with two layers of multi-strands, characterized in that the cable (50) comprises: - an internal layer (Cl) of the cable consisting of X=1 multi-strands M1 of diameter DM1 comprising K>1 strands (T1) wound in a helix around a main axis (A), each strand (T1) having at least two layers (C1, C3) comprising: - an internal layer (C1) consisting of Q1 internal metal wire(s) (F1), and - an outer layer (C3) made up of Q3 external metal wires (F3) wound around the inner layer (C1), and - an outer layer (CE) of the cable consisting of Y>1 multi-strands M2 of diameter DM2 wound around the inner layer (Cl) of the cable, each multi-strand M2 comprising L>1 strands (T2) wound helically around an axis (A), each strand (T2) having at least two layers (CT; C3’) comprising: - an internal layer (CT) made up of QT internal metal wire(s) (FT), and - an outer layer (C3’) consisting of Q3’ external metal wires (F3’) wound around the inner layer (CT), with the multi-strands (M2) being wound helically around the main axis (A), 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 for 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 on its elastic part and the axis of elongations of the force-elongation curve; and with a saturation ratio TT X (DM1+DM2)/(Y x DM2) greater than or equal to 1.11.
  2. 2. Cable (50) according to the preceding claim, in which As > 1.5% and preferably As > 2.0%.
  3. 3. Multi-strand cable (50’) with two layers of multi-strands extracted from a polymer matrix (102), characterized in that the extracted cable (50’) comprises: - an internal layer (Cl) of the cable consisting of X=1 multi-strands M1 of diameter DM1 comprising K>1 strands (T1) wound in a helix around a main axis (A), each strand (T1) having at least two layers (C1, C3) comprising: - an internal layer (C1) consisting of Q1 internal metal wire(s) (F1), and - an outer layer (C3) made up of Q3 external metal wires (F3) wound around the inner layer (C1), and - an outer layer (CE) of the cable consisting of Y>1 multi-strands M2 of diameter DM2 wound around the inner layer (Cl) of the cable, each multi-strand M2 comprising L>1 strands (T2) wound helically around an axis (A'), each strand (T2) having at least two layers (CT; C3') comprising: - an internal layer (CT) made up of QT internal metal wire(s) (FT), and - an outer layer (C3’) consisting of Q3’ external metal wires (F3’) wound around the inner layer (CT), with the multi-strands (M2) being wound helically around the main axis (A), the 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 for 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 on its elastic part and the axis of elongations of the force-elongation curve; and with a saturation ratio TT X (DM1+DM2)/(Y x DM2) greater than or equal to 1.11.
  4. 4. Cable (50,50') according to any one of the preceding claims, in which the diameter D of the cable ranges from 3 mm to 9.5 mm, preferably from 4 mm to 7.5 mm.
  5. 5. Cable (50,50’) according to any one of the preceding claims, in which the diameters of the metal wires (F1; F3; FT; F3’) range independently of each other 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.
  6. 6. Cable (50,50’) according to any one of the preceding claims, in which Y is equal to 5, 6, 7, 8, 9 or 10, preferably Y=6, 7 or 8 and more preferably Y=6.
  7. 7. Cable (50,50’) according to any one of the preceding claims, in which K= 2, 3 or 4, preferably K=3 or 4.
  8. 8. Cable (50,50’) according to any one of the preceding claims, in which L = 2,3 or 4 and preferably L =3 or 4.
  9. 9. Cable (50,50') according to any one of the preceding claims, in which each strand (T1) of the inner layer (Cl) has two layers (C1, C3).
  10. 10. Cable (50,50') according to any one of claims 1 to 8, in which each strand (T2) of the outer layer (CE) has two layers (CT, C3').
  11. 11. Cable (60) according to any one of claims 1 to 8, in which each strand (T1) of the inner layer (Cl) is three-layered (C1, C2, C3) and comprises: an intermediate layer (C2) consisting of Q2 intermediate metal wires (F2) wound around the inner layer (C1), and an outer layer (C3) consisting of Q3 outer metal wires (F3) wound around the intermediate layer (C2).
  12. 12. Cable (60) according to any one of claims 1 to 8, in which each strand (T2) of the outer layer (CE) is three-layered (CT, C2', C3') and comprises: an intermediate layer (C2') consisting of Q2' intermediate metal wires (F2') wound around the inner layer (CT), and an outer layer (C3') consisting of Q3' outer metal wires (F3') wound around the intermediate layer (C2').
  13. 13. Cable (50,50') according to any one of claims 1 to 10, in which each strand (T1; T2) of the inner and outer layers (Cl; CE) is two-layered (C1, C3, CT, C2’).
  14. 14. Reinforced product (100), characterized in that it comprises a polymer matrix (102) and at least one extracted 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. 15. Tire (10), characterized in that it comprises at least one extracted cable (50') such that the properties of this cable, measured after extraction of the tire, are those of the extracted cable (50') according to any one of claims 3 to 13 or a reinforced product according to claim 14.

Description

Multi-strand cable with two layers of multi-strands [001] The invention relates to cables and a tire comprising these cables. [002] The state of the art discloses cables having a (1+6)x(3+8) structure as described in document FR2969181 letter B. These cables comprise 6 strands wound in a helix around a strand at a pitch of 60 mm. Each strand comprises, on the one hand, an inner layer of 3 inner wires wound in a helix at a pitch of 7.7 mm and an outer layer of 8 outer wires wound in a helix around the inner layer at a pitch of 15.4 mm. The structural elongation of the cable is less than 0.2% and the breaking force is 19,600 N. [003] These cables are rigid cables, they have the advantage of relieving tension on the working plies but of very substantially increasing the circumferential rigidity of the structure, leading to increased sensitivity of the crown block to attacks at the center of the tread when they are placed at the level of the additional reinforcement. [004] Also known from the state of the art are cables as described in US2792868. [005] Today, a need is emerging for the development of new cables for crown plies applications, in particular plies with laying angles of less than 10° such as the additional reinforcement. The purpose of this reinforcement is to relieve tension in the working plies, to increase the endurance performance of the tire, especially the resistance to cleavage. [006] The aim of the invention is to provide a cable having a good compromise in rigidity: flexible enough to reduce the rigidity of the crown block with a breaking force sufficient to withstand extension stresses. [007] For this purpose, the invention relates to a multi-strand with two layers of multi-strands, in which the cable comprises: - an internal layer of the cable consisting of X=1 multi-strands M1 of diameter DM1 comprising K>1 strands wound in a helix around a main axis, each strand having at least two layers comprising: - an internal layer consisting of Q1 internal metal wire(s), and - an outer layer consisting of Q3 external metal wires wound around the inner layer, and - an outer layer of the cable consisting of Y>1 multi-strands M2 of diameter DM2 wound around the inner layer of the cable, each multi-strand M2 comprising L>1 strands wound helically around an axis, each strand having at least two layers comprising: - an internal layer consisting of Q1’ internal metal wire(s), and - an outer layer consisting of Q3' external metal wires wound around the inner layer, with the multi-strands being wound helically around the main axis, 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 on its elastic part and the axis of elongations of the force-elongation curve; and with a saturation ratio TT X (DM1+DM2)/(Y x DM2) greater than or equal to 1.11. [008] Thanks to this multi-strand cable configuration with two layers of desaturated multi-strands, the cable according to the invention makes it possible to obtain a cable with sufficient structural elongation providing flexibility in extension and sufficient metal mass, while keeping fine wires for flexibility in bending, to improve the compromise between shear in the polymer matrix, flexibility and resistance of the crown block and thus improve the compromise of aggression and cleavage performance. [009] The structural elongation As, a quantity well known to those skilled in the art, is determined for example by applying the ASTM D2969-04 standard of 2014 to a cable tested so as to obtain a force-elongation curve. The As on the curve obtained is deduced as the elongation, in %, corresponding to the intersection between the tangent to the elastic part of the force-elongation curve and the axis of the elongations of the force-elongation curve. As a reminder, a force-elongation curve comprises, moving towards increasing elongations, a structural part, an elastic part and a plastic part. The structural part corresponds to a structural elongation of the cable resulting from the bringing together of the different strands and metal wires constituting the cable. The elastic part corresponds to an elastic elongation resulting from the construction of the cable, in particular from 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. [010] In the invention, the cable comprises two layers of multi-strands, that is to say it comprises an assembly consisting of a layer of Y>1 multi-strands wound around a single layer of multi-strands, no more and no less, that is to say the assembl