Classifications

• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/062—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration
  • D07B1/0633—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration having a multiple-layer configuration
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S57/00—Textiles: spinning, twisting, and twining
  • Y10S57/902—Reinforcing or tire cords
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
  • Y10T428/249933—Fiber embedded in or on the surface of a natural or synthetic rubber matrix
  • Y10T428/249934—Fibers are aligned substantially parallel

Definitions

• the present invention relates to steel cables ("steel cords") which can be used for reinforcing rubber articles such as tires. It relates more particularly to so-called “layered” cables which can be used to reinforce the crown reinforcement of radial tires.
• Steel cables for tires are generally made up of carbon pearlitic (or ferrito-pearlitic) steel wires, hereinafter referred to as "carbon steel", the carbon content of which is generally between 0.2% and 1.2%, the diameter of these wires generally being between 0.10 and 0.50 mm (millimeter).
• carbon steel the carbon content of which is generally between 0.2% and 1.2%
• the diameter of these wires generally being between 0.10 and 0.50 mm (millimeter).
• These wires are required to have a very high tensile strength, generally greater than 2000 MPa, preferably greater than 2500 MPa, obtained by virtue of the structural hardening occurring during the work hardening phase of the wires.
• These wires are then assembled in the form of cables or strands, which requires the steels used that they also have sufficient torsional ductility to support the various wiring operations.
• layered cords or “multilayer” steel cables consisting of a central core and one or more layers of wire. concentric arranged around this soul.
• These layered cables are preferred to older cables known as “strand cords” because on the one hand of a lower industrial cost, on the other hand of a greater compactness making it possible in particular to reduce the thickness of the rubber plies used for the manufacture of tires.
• strand cords cables
• cables with a compact structure cables with tabular or cylindrical layers.
• those most common in the crown reinforcement of radial tires are essentially cables of the formula [M + N] or [M + N + P], the latter being generally intended for larger tires.
• These cables are formed so as the known a M wire core (s) surrounded by at least one layer of N son . optionally itself surrounded by an outer layer of P wires, with in general M varying from 1 to 4, N varying from 3 to 12, P varying from 8 to 20 if necessary, the assembly possibly being shrunk by a outer hoop wire wound helically around the last layer.
• the layered cables must first of all have a high rigidity in compression, which implies in particular that their wires, at least for the majority of them, have a relatively large diameter, in general at least equal to 0.25 mm, greater in particular than that of the wires used in conventional cables for the carcass reinforcement of tires.
• these cables are impregnated as much as possible with rubber, that this material penetrates into all the spaces between the wires constituting the cables. Indeed, if this penetration is insufficient, then empty channels are formed, along the cables, and corrosive agents, for example water, capable of penetrating into the tires for example following cuts or other attacks from the crown of the tire, travel along these channels through the crown reinforcement of the tire. The presence of this moisture plays an important role in causing corrosion and accelerating fatigue process (called "fatigue-corrosion” phenomena), compared to a dry atmosphere. -
• the publication RD No. 34370 proposes, to solve this problem, cables of structure [1 + 6 + 12], of the compact type or of the type with concentric tubular layers, consisting of a core formed of a single wire, surrounded by '' an intermediate layer of 6 wires itself surrounded by an outer layer of 12 wires.
• the penetrability by the rubber can be improved by using different wire diameters from one layer to another, or even within the same layer.
• Construction cables [1 + 6 + 12] the penetration of which is improved by an appropriate choice of the diameters of the wires, in particular the use of a core wire of larger diameter, have also been described, for example in EP-A-0 648 891 or O98 / 41682.
• multilayer cables have also been proposed or described with a central core surrounded by at least two concentric layers, in particular cables of formula [1 + N + P] (for example [1 + 4 + P] or [1 + 5 + P]) or even [2 + N + P] (for example [2 + 5 + P]), whose outer layer is unsaturated (ie, incomplete), thus ensuring better penetration by rubber (see for example RD N ° 316107, August 1990, p. 681; EP-A-0 567 334 or US-A-5 661 965; EP-A-0 661 402 or US-A- 5,561,974; EP-A-0 675 223).
• cables of formula [1 + N + P] for example [1 + 4 + P] or [1 + 5 + P]
• [2 + N + P] for example [2 + 5 + P]
• the cables When used for the reinforcement of tire crown reinforcement, the cables must certainly resist corrosion but also satisfy a large number of other criteria, sometimes contradictory, in particular of toughness, high adhesion to rubber, uniformity, flexibility , impact and puncture resistance, endurance in compression and flexion-compression, all in a more or less corrosive atmosphere.
• the invention also relates to the use of a cable according to the invention for the reinforcement of articles or semi-finished products made of plastic and / or rubber, for example plies, pipes, belts, conveyor belts, tires, more particularly radia ⁇ x tires using a metal crown reinforcement.
• the cable of the invention is very particularly intended to be used as a reinforcement element for the crown reinforcement of radial tires intended for industrial vehicles chosen from vans, "Heavy vehicles” - ie, metro, bus, road transport vehicles ( trucks, tractors, trailers), off-road vehicles -, agricultural or civil engineering machinery, airplanes, other transport or handling vehicles.
• the invention also relates to these semi-finished articles or products made of plastic and / or rubber themselves when they are reinforced with a cable according to the invention, in particular tires intended for the vehicles mentioned above, as well as composite fabrics comprising a rubber composition matrix reinforced with a cable according to the invention, which can be used in particular as a crown reinforcement ply of such tires.
• the air permeability test makes it possible to measure a relative index of air permeability noted "R". It constitutes a simple means of indirect measurement of the penetration rate of the cable by a rubber composition. It is carried out on cables extracted directly, by shelling, from the vulcanized rubber sheets which they reinforce, therefore penetrated by the cooked rubber.
• the test is carried out on a determined cable length (for example 2 cm) in the following manner: air is sent to the cable inlet, under a given pressure (for example 1 bar), and the quantity is measured air at the outlet, using a flow meter; during the measurement the cable sample is blocked in a tight seal so that only the quantity of air passing through the cable from one end to the other, along its longitudinal axis, is taken into account by the measurement.
• the measured flow is lower the higher the penetration rate of the cable by the rubber.
• the diameter of the core and that of the wires of layers C1 and C2 i the helix pitches (therefore the angles) and the winding directions of the different layers are defined by the set of the following characteristics (d 0 , d ] 5 d 2 , pi and p 2 expressed in mm):
• N 4: 0.40 ⁇ (d 0 / d,) ⁇ 0.80; for N ⁇ 5: 0.70 ⁇ (d 0 / d,) ⁇ 1.10;
• the cable of the invention in particular when it does not have an external hoop wire, preferably checks the characteristic (vii) below:
• Characteristics (v) and (vi) - different p ,, and p 2 and layers C1 and C2 wound in the same direction of twist - mean that, in known manner, the wires of layers C1 and C2 are essentially arranged in two cylindrical (ie tubular), adjacent and concentric layers.
• cables with so-called “tubular” or “cylindrical” layers we mean cables made up of a core (ie, core or central part) and one or more concentric layers, each of tubular shape, arranged around of this core, in such a way that, at least in the cable at rest, the thickness of each layer is substantially equal to the diameter of the wires which constitute it; it follows that the cross section of the cable has a contour or envelope (denoted E) which is substantially circular, as illustrated for example in FIG. 1.
• the cables with cylindrical or tubular layers of the invention must in particular not be confused with cables with so-called “compact” layers, assemblies of wires wound at the same pitch and in the same direction of twist; in such cables, the compactness is such that practically no distinct layer of wires is visible; it follows that the cross section of such cables has a contour which is no longer circular, but polygonal.
• the outer layer C2 is a tubular layer of P wires called "unsaturated” or "incomplete”, that is to say that, by definition, there is enough space in this tubular layer C2 to add at least one (P + l) th wire of diameter d 2. several of the P sons possibly being in contact with each other. Conversely, this tubular layer C2 would be qualified as “saturated” or “complete” if there was not enough room in this layer to add at least one (P + 1) th wire of diameter d 2 .
• the cable of the invention is a layered cable of construction denoted [1 + N + P], that is to say that its core consists of a single wire (M + l), such that shown for example in Figure 1 (cable noted CI).
• This Figure 1 shows schematically a section perpendicular to the axis (denoted O) of the core and the cable, the cable being assumed to be straight and at rest.
• the core C0 (diameter d 0 ) is formed of a single wire; it is surrounded and in contact with an intermediate layer C1 of 5 wires of diameter di wound together in a helix at a pitch pi; this layer C1, of thickness substantially equal to d b is itself surrounded and in contact with an external layer C2 of 10 wires of diameter d 2 wound together in a helix according to a ' pitch p 2 , and therefore of thickness substantially equal to d 2 .
• the wires wound around the core CO are thus arranged in two adjacent and concentric, tubular layers (layer C1 of thickness substantially equal to di, then layer C2 of thickness substantially equal to d 2 ).
• layer C1 of thickness substantially equal to di
• layer C2 of thickness substantially equal to d 2
• the wires of layer C1 have their axes (denoted Oi) arranged practically on a first circle Ci shown in dotted lines
• the wires of layer C2 have their axes (denoted O 2 ) arranged practically on a second circle C 2 , also shown in dotted lines.
• the diameter d 0 of the core is preferably within a range of 0.15 to 0.30 mm, more particularly from 0.15 to 0.20 mm in the case of a structure cable [M + 4 + P], from 0.20 to 0.30 mm in the case of a structural cable [M + 5 + P], with in particular M equal to 1.
• the surface of the penetration channels between these two layers is increased and further improved cable penetration, while optimizing its fatigue-corrosion and compression performance.
• the pitch represents the length, measured parallel to the axis O of the cable, at the end of which a wire having this pitch makes a complete revolution around the axis O of the cable; thus, if the axis O is sectioned by two planes perpendicular to the axis O and separated by a length equal to the pitch of a wire from one of the two layers Cl or C2, the axis of this wire (Oi or O 2 ) has in these two planes the same position on the two circles corresponding to the layer C1 or C2 of the wire considered.
• all the wires of layers C1 and C2 are wound in the same direction of twist, that is to say either in the direction S (arrangement noted “S / S”), or in direction Z (arrangement marked “Z / Z”).
• Such an arrangement of layers C1 and C2 is rather contrary to the most conventional constructions of layered cables [M + N + P], in particular those of construction [3 + 9 + 15], which most often require crossing of the two layers Cl and C2 (either an "S / Z" or "Z / S” arrangement) so that the wires of the layer C2 come to fry the wires of the layer Cl.
• the winding in the same direction of the layers C1 and C2 advantageously makes it possible, in the cable according to the invention, to minimize the friction between these two layers C1 and C2 and therefore the wear of the wires which constitute them.
• the ratios (d 0 / d ⁇ ) must be fixed within determined limits, according to the number N (4 or 5) of wires of the layer Cl. Too low a value of this ratio is detrimental to penetration by rubber. A too high value harms the compactness of the cable, for a level of resistance that is ultimately little modified; increased rigidity of the core due to a diameter d 0 too large would also be detrimental to the feasibility itself of the cable, during the wiring operations.
• the wires of layers C1 and C2 can have an identical or different diameter from one layer to another.
• the maximum number P max of wires wound in a single saturated layer around the layer Cl is of course a function of many parameters (diameter d 0 of the core, number N and diameter di of the wires of the layer Cl, diameter d 2 of the layer C2). For example, if P max is equal to 12, P can then vary from 9 to 11 (for example constructions [l + N + 9], [l + N + 10] or [1 + N + ll]) ; if P max is for example equal to 11, P can then vary from 8 to 10 (for example constructions [l + N + 8], [l + N + 9] or [l + N + 10]).
• the number P of wires in the layer C2 is 1 to 2 less than the maximum number P max .
• the invention is thus preferably implemented with a cable chosen from structural cables [1 + 4 + 8], [1 + 4 + 9], [1 + 4 + 10], [1 + 5 + 9], [1 + 5 + 10] and [1 + 5 + 11].
• the invention is preferably implemented in the crown reinforcement of truck tires, with cables of structure [1 + 5 + P], more preferably of structure [1 + 5 + 9], [1 + 5 + 10] or [1 + 5 + 11]. Even more preferably, cables of structure [1 + 5 + 10] or [1 + 5 + 11] are used.
• the wires of the layer C1 can be chosen to have a diameter greater than those of the layer C2, for example in a ratio (dJd 2 ) preferably between 1.05 and 1, 30.
• the diameters of the wires of layers C1 and C2 that these wires have the same diameter or not, are in a range of 0.25 to 0.35 mm.
• the steps pi and p 2 are preferably chosen to be between 7 and 21 mm, while more preferably checking at least one of the relations (vii) or (viii) mentioned above.
• An advantageous embodiment consists for example in choosing pi between 7 and 14 mm and p 2 between 14 and 21 mm.
• the invention can be implemented with any type of steel wire, for example carbon steel wire and / or stainless steel wire as described for example in applications EP-A-0 648 891 or WO98 / 41682 cited above.
• steel wire for example carbon steel wire and / or stainless steel wire as described for example in applications EP-A-0 648 891 or WO98 / 41682 cited above.
• carbon steel is used, but it is of course possible to use other steels or other alloys.
• carbon steel When carbon steel is used, its carbon content (% by weight of steel) is preferably between 0.50% and 1.0%, more preferably between 0.68% and 0.95%; these contents represent a good compromise between the mechanical properties required for the tire and the feasibility of the wire. It should be noted that in applications where the highest mechanical strengths are not necessary, it is advantageous to use carbon steels whose carbon content is between 0.50% and 0.68%, in particular varies from 0, 55% to 0.60%, such steels being ultimately less expensive because they are easier to draw. Another advantageous embodiment of the invention may also consist, depending on the intended applications, of using steels with a low carbon content, for example between 0.2% and 0.5%, in particular because of a cost lower and easier to draw.
• the constituent wires of the cables of the invention preferably have a tensile strength greater than 2000 MPa, more preferably greater than 3000 MPa. In the case of tires of very large dimensions, one will especially choose cords whose tensile strength is between 3000 MPa and 4000 MPa. Those skilled in the art know how to manufacture carbon steel wires having such a resistance, in particular by adjusting the carbon content of the steel and the final work hardening rates ( ⁇ ) of these wires.
• the cable of the invention could comprise an external hoop, consisting for example of a single wire, metallic or not, wound helically around the cable at a shorter pitch than that of the outer layer, and an opposite winding direction or identical to that of this outer layer.
• an external hoop consisting for example of a single wire, metallic or not, wound helically around the cable at a shorter pitch than that of the outer layer, and an opposite winding direction or identical to that of this outer layer.
• the cable of the invention already self-wrapped, does not generally require the use of an external wrapping wire, • the one hand advantageously solves the problems of wear between the hoop and the wires of the outermost layer of the cable, on the other hand makes it possible to reduce the overall diameter and the cost of the cable.
• a hoop wire in the general case where the wires of layer C2 are made of carbon steel, it is then advantageously possible to choose a hoop wire of stainless steel in order to reduce the wear by fretting of these wires.
• a hoop wire of stainless steel made of carbon steel in contact with the stainless steel hoop, as taught by the aforementioned application WO98 / 41682, the stainless steel wire being able to be optionally replaced, in an equivalent manner, by a composite wire of which only the skin is made of stainless steel and the carbon steel core, as described for example in patent application EP-A-0 976 541.
• the cable of the invention can advantageously be used in crown reinforcement for all types of tires, in particular tires for large vans, heavy vehicles or civil engineering vehicles.
• FIG. 2 schematically represents a radial section of a tire with a metal crown reinforcement which may or may not conform to the invention, in this general representation.
• This tire 1 comprises a crown 2 reinforced by a crown reinforcement 6, two sidewalls 3 and two beads 4, each of these beads 4 being reinforced with a bead wire.
• the crown 2 is surmounted by a tread not shown on this schematic figure.
• a carcass reinforcement 7 is wound around the two rods 5 in each bead 4, the reversal 8 of this reinforcement 7 being for example disposed towards the outside of the tire 1 which is here shown mounted on its rim 9.
• the carcass reinforcement 7 is in a manner known per se consisting of at least one ply reinforced by so-called "radial” cables, that is to say that these cables are arranged practically parallel to each other and extend from a bead to the other so as to form an angle between 80 ° and 90 ° with the median circumferential plane (plane perpendicular to the axis of rotation of the tire which is located midway between the two beads 4 and passes through the middle of the 'crown reinforcement 6).
• the tire according to the invention is characterized in that its crown reinforcement 6 comprises at least one crown ply, the reinforcement cables of which are multilayer steel cables according to the invention.
• the cables of the invention can for example reinforce all or part of the so-called working crown plies, or so-called crown plies (or half-plies) triangulation and / or so-called protective top plies, when such triangulation or protective top plies are used.
• the crown reinforcement 6 of the tire of the invention can of course comprise other crown plies, for example one or more crown plies called hooping plies.
• the density of the cables according to the invention is preferably between 20 and 70 cables per dm (decimeter) of crown ply, more preferably between 30 and 60 cables per dm of ply, the distance between two adjacent cables, from axis to axis, thus preferably being between 1.4 and 5.0 mm, more preferably between 1.7 and 3.3 mm.
• the cables according to the invention are preferably arranged in such a way that the width (denoted "- £") of the rubber bridge, between two adjacent cables, is between 0.5 and 2.0 mm. This width - ⁇ represents in known manner the difference between the calendering pitch (no laying of the cable in the rubber fabric) and the diameter of the cable. Below the minimum value indicated, the rubber bridge, too narrow, risks mechanical deterioration when working the ply,
• the width -t is chosen to be between 0.8 and 1.6 mm.
• the rubber composition used for the fabric of the crown reinforcement ply has, in the vulcanized state (i.e., after baking), a secant module in extension MA10 which is greater than 5 MPa. More preferably, the MA10 module is between 5 and 20 Mpa, in particular between 5 and 10 MPa when this fabric is intended to form a triangulation or protection sheet of the crown reinforcement, between 8 and 20 MPa when this fabric is intended to form a working ply of the crown reinforcement. It is in such fields of modules that the best endurance compromise has been recorded between the cables of the invention on the one hand, and the reinforced fabrics of these cables on the other hand.
• fine carbon steel wires are used, prepared according to known methods as described, for example, in the abovementioned applications EP-A-0 648 891 or WO98 / 41682. , starting from commercial wires with an initial diameter of about 1.75 mm.
• the steel used is a known carbon steel, the carbon content of which is approximately 0.9%.
• the commercial starting wires first undergo a known degreasing and / or pickling treatment before their subsequent implementation. At this stage, their breaking strength is approximately 1150 MPa, their elongation at break is approximately 10%. Copper is then deposited on each wire, followed by a zinc deposit, by electrolytic means at room temperature, and then heat is heated by Joule effect to 540 ° C. to obtain brass by diffusion of copper and zinc, the weight ratio (phase ⁇ ) / (phase ⁇ + phase ⁇ ) being equal to approximately 0.85. No heat treatment is carried out on the wire after obtaining the brass coating.
• a so-called “final” work hardening is then carried out on each wire (ie after the last heat treatment), by cold wire drawing in a humid environment with a wire drawing lubricant which present as an emulsion in water.
• This wet drawing is carried out in a known manner in order to obtain the final work hardening rate (denoted ⁇ ) calculated from the initial diameter indicated previously for the starting commercial wires.
• the steel wires thus drawn have the mechanical properties indicated in Table 1.
• the elongation At indicated for the wires is the total elongation recorded when the wire breaks, that is to say integrating both the elastic part of the elongation (Hooke's law) and the plastic part of the elongation.
• the brass coating which surrounds the wires has a very small thickness, clearly less than a micrometer, for example of the order of 0.15 to 0.30 ⁇ m, which is negligible compared to the diameter of the steel wires.
• the composition of the steel of the wire in its various elements is the same as that of the steel of the starting wire.
• the brass coating facilitates the wire drawing, as well as the bonding of the wire with the rubber.
• the wires could be covered with a thin metallic layer other than brass, for example having the function of improving the corrosion resistance of these wires and / or their adhesion to rubber, for example a thin layer of Co , Ni, Zn, Al, an alloy of two or more of the compounds Cu, Zn, Al, Ni, Co, Sn.
• the preceding wires are then assembled in the form of cables with structural layers [1 + 5 + 10].
• These cables are manufactured with wiring devices (Barmag cabling machine) and according to methods well known to those skilled in the art which are not described here for the simplicity of the description. Due to different pi and p 2 pitch, they are carried out in two successive operations (manufacturing a cable [1 + 5] then wiring the last layer around this cable [1 + 5]), these two operations being advantageously be made online using two stranding machines arranged in series.
• These cables according to the invention have the following characteristics:
• the wires F2 of layers C1 and C2 are wound in the same direction of twist (direction S).
• the cable tested has no ferrule and has a diameter of about 1.34 mm.
• the core of this cable has a diameter d 0 equal to that of its single wire, practically devoid of twist on itself.
• the cable of the invention exemplified here is a cable with tubular layers as shown schematically in cross section in Figure 1, already discussed above. It differs from the cables of the prior art in particular by the fact that its outer layer C2 comprises two wires less than a conventional saturated cable and that its pitches pi and p 2 are different while also checking the relation (v) supra. In other words, in this cable, P is 2 less than the maximum number (here P max ⁇ 12) of wires wound in a single saturated layer around the layer Cl. To further increase its penetration by rubber, the wires of layer C1 were chosen with a diameter greater than those of layer C2 in a preferred ratio (dJd 2 ) of between 1.05 and 1.15.
• This C-I cable showed excellent penetration by the rubber, measured in the air permeability test. It also checks each of the following preferential relationships:
• the elongation At indicated for the cable is the total elongation recorded at the break of the cable, that is to say integrating both the elastic part of the elongation (Hooke's law), the plastic part of the elongation and the so-called structural part of the elongation inherent in the specific geometry of the cable tested.
• the procedure for manufacturing the tires of the invention is as follows.
• the preceding layered cables are incorporated by calendering into a rubberized fabric formed of a known composition based on natural rubber and carbon black as reinforcing filler, conventionally used for the manufacture of crown reinforcement plies for radial tires (module MA 10 equal to around 18 MPa, after cooking).
• This composition essentially comprises, in addition to the elastomer and the reinforcing filler, an antioxidant, stearic acid, a reinforcing resin (phenolic resin plus methylene donor), cobalt naphthenate as an adhesion promoter, finally a vulcanization system (sulfur, accelerator, ZnO).
• the cables are arranged parallel in a known manner, according to a determined cable density, for example 40 cables per dm of ply, which, taking into account the diameter of the cables, is equivalent to a width "- #" rubber bridges, between two adjacent cables, lying in a particularly preferential range of 1.0 to 1.4 mm (in the present case, approximately 1.16 mm).
• the tires, manufactured in a known manner, are as shown diagrammatically in FIG. 2, already commented on.
• Their radial carcass reinforcement 7 is for example made up of a single radial ply formed of a conventional rubberized fabric comprising conventional metallic cables arranged at an angle of approximately 90 ° with the median circumferential plane.
• the crown reinforcement 6 it consists of (i) two crossed overlapping working plies, reinforced with metal cables inclined by 22 degrees, these two working plies being covered by (ii) a protective crown ply reinforced with conventional elastic metal cables inclined by 22 degrees.
• Each of the two working plies is formed from the rubberized fabric according to the invention.
• the cables of the invention make it possible to reduce the phenomena of corrosion and of fatigue-corrosion, in particular under conditions of fatigue under compression, in particular in the crown reinforcement of radial tires, and thus to improve the longevity of • such crown reinforcement.
• the core CO of the cables of the invention could consist of a wire with a non-circular section, for example plastically deformed, in particular a wire with a substantially oval or polygonal section, for example triangular, square or still rectangular; the core CO could also consist of a preformed wire, of circular section or not, for example a wavy, twisted, twisted wire in the form of a helix or in a zig-zag.
• the diameter d 0 of the core represents the diameter of the imaginary cylinder of revolution which surrounds the core wire (overall diameter), and no longer the diameter (or any other transverse size, if its section is not circular) of the core wire itself.
• the core CO was formed not of a single wire as in the previous examples, but of several wires assembled together, for example two wires arranged parallel to one another or else twisted together, in a direction of twist identical or not to that of the intermediate layer Cl.
• the core wire being less stressed during the wiring operation than the other wires, given its position in the cable, it is not necessary for this wire to use, for example, compositions. steel with high torsional ductility; it is advantageously possible to use any type of steel, for example stainless steel, in order to result, for example, in a hybrid steel cable as described in the aforementioned application WO98 / 41682, comprising a stainless steel wire in the center and carbon steel wires around.
• one (at least one) linear wire from one of the two layers C1 and / or C2 could also be replaced by a preformed or deformed wire, or more generally by a wire of section different from that of other wires of diameter. di and / or d 2 , so as for example to further improve the penetrability of the cable with rubber or any other material, the overall diameter of this replacement wire possibly being less, equal or greater than the diameter (di and / or d 2 ) of the other constituent wires of the layer (Cl and / or C2) concerned.
• all or part of the wires constituting the cable according to the invention could consist of wires other than steel wires, metallic or not, in particular wires made of mineral or organic material to high mechanical strength, for example monofilaments made of organic liquid crystal polymers as described in application WO92 / 12018.
• the invention also relates to any multi-strand steel cable.
• ⁇ multi-strand rope whose structure incorporates at least, as an elementary strand, a layered cable according to the invention.

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• 2001
  • 2001-12-21 JP JP2002554316A patent/JP2004527666A/ja active Pending
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  • 2001-12-21 WO PCT/EP2001/015189 patent/WO2002053827A1/fr not_active Application Discontinuation
• 2003
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