A tire featuring a bracing ply with hydrophobic weft threads and a crown with reduced thickness.

Abstract

The tire (10) comprises a crown reinforcement (16) including a working reinforcement (20) including a radially outermost working ply (26) and a bracing reinforcement (22) including a plurality of filamentary woven bracing elements (220) spirally wound radially around the working reinforcement (20) and connected to each other by one or more filamentary weft elements (42). At the axially central portion (PO) of the crown (12), the average radial distance E1 between the bottom of the tread groove and the filamentary woven bracing elements (220) is E1≦2.00 mm. Each filamentary weft element (42) comprises a plurality of woven monofilaments and / or a plurality of woven fibers selected from synthetic organic polymer monofilaments and fibers, synthetic inorganic polymer monofilaments and fibers, and aggregates of these monofilaments and fibers.

Description

[[Technical Field]]

[0001] The present invention relates to tires. A tire means an enclosure intended to form a cavity in cooperation with a support element such as a rim, the cavity being capable of being pressurized to a pressure exceeding atmospheric pressure. The tire according to the present invention has a substantially toroidal structure exhibiting rotational symmetry about the main axis of the tire. [[Background Art]]

[0002] Passenger vehicle tires including a crown that also comprises a tread and a crown reinforcement are known from the prior art. Conventionally, the crown reinforcement comprises a hoop reinforcement and a working reinforcement. The hoop reinforcement is arranged radially outward of the working reinforcement and radially inward of the tread.

[0003] The working reinforcement comprises a radially inner working layer and a radially outer working layer arranged radially outward of the radially inner working layer. Each of the radially inner and radially outer working layers is axially bounded by two axial edges of the working layer, and comprises metal filament-like working reinforcing elements extending substantially parallel to each other axially from one axial edge of the working layer to the other axial edge.

[0004] The hoop reinforcement is axially bounded by two axial edges, and comprises a strip spirally wound over a plurality of circumferential windings so as to extend axially between the two axial edges. The strip comprises a plurality of textile filament-like hooping reinforcing elements that are substantially parallel to each other and extend in the main hooping direction.

[0005] First, despite their excellent performance, these tires have been observed to exhibit oxidation pockets in the working reinforcement, particularly in the radially outer working layer, after being driven under extremely harsh conditions and in the presence of corrosive agents. Such extremely harsh conditions occur especially when the tires are driven on rocky surfaces. While oxidation pockets do not threaten safe use, they can cause vibrations for the driver and are a source of discomfort that is desirable to eliminate.

[0006] Next, in order to reduce tire weight, rolling resistance, and environmental impact, there is a need to reduce the amount of material used, particularly in the tire crown. However, reducing the amount of material used in the crown, as expected, means that the hoop reinforcement and working reinforcement are more exposed to penetration by corrosive agents, and therefore are exposed more quickly and extensively to the formation of the aforementioned oxidation pockets. Thus, although lighter tires can certainly be obtained, they come with increased vibrational discomfort, which is undesirable. [Overview of the project] [Problems that the invention aims to solve]

[0007] The objective of the present invention is to provide a tire that improves the balance between vibrational discomfort caused by oxidation pockets and tire weight, and therefore its rolling resistance. [Means for solving the problem]

[0008] For this purpose, the present invention relates to a tire including a crown with a tread supporting the tread surface, wherein the crown has an axial center portion extending over an axial width equal to 50% of the axial width of the tread surface and positioned with the axial center above the midline plane of the tire, and the axial center portion of the tread has at least one deepest notch. The Crown is - A working reinforcement comprising at least one radially outermost working layer having metal filament-like working reinforcement elements, - A hoop reinforcement comprising a plurality of woven filament hooping reinforcement elements spirally wound around a working reinforcement in the radial direction and connected to one or more filament weft elements, wherein the hoop reinforcement is positioned radially outward of the working reinforcement and radially inward of the tread, It includes a crown reinforcement, In this tire, at the axial center of the crown, - Passing through the innermost radial point of the deepest cut in the axial center of the tread, and a surface substantially parallel to the tread surface, -The radial outer surface passing through the radially outermost point of the radially outermost woven filamentous hooping reinforcing element among the woven filamentous hooping reinforcing elements, The average radial distance E1 between them is E1 ≤ 2.00 mm. In this tire, the filamentous weft element(s) or at least one thereof comprises a plurality of woven monofilaments and / or a plurality of woven fibers selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic fibers and monofilaments, and aggregates thereof of monofilaments and fibers.

[0009] To achieve the objectives of the present invention, the inventors needed to demonstrate the mechanism leading to the formation of oxidation pockets. Accordingly, the inventors observed that the extremely harsh conditions encountered when tires travel on a rocky road surface are such that the stones covering the road surface attack the tire tread, forming depressions that penetrate the tread and reach the crown reinforcement. Once the tread is subjected to these attacks, corrosive agents, particularly moisture and salt, first penetrate the crown reinforcement via the hoop reinforcement. Next, it was observed that in the hoop reinforcement of prior art tires, the corrosive agents are transmitted to the hoop reinforcement not via the woven filamentous hooping reinforcement elements, but rather by the filamentous weft elements connecting the woven filamentous hooping reinforcement elements to one another. This transmission of corrosive agents is made possible precisely by the properties of the filamentous weft elements, which comprise aggregates containing cotton monofilaments. Until the inventors discovered, the use of cotton was driven solely by its relatively low cost and the fact that such filamentous weft elements were only useful in the manufacturing process of the hoop reinforcement described later and did not affect the formation of oxidation pockets.

[0010] In fact, in prior art tires, such filamentous weft elements are substantially parallel to each other in the main weft direction, which is not collinear with the main hooping direction. The main weft direction and the main hooping direction are substantially perpendicular. Such filamentous weft elements are used in the process of manufacturing strips, during which, in the step of manufacturing a very wide fabric, woven filamentous hooping reinforcement elements are arranged substantially parallel to each other and connected to each other by one or more filamentous weft elements, each filamentous weft element extending across the entire width of the very wide fabric. In the subsequent sizing step, the woven filamentous hooping reinforcement elements and filamentous weft elements are coated with one or more layers of one or more adhesive compositions, and then the pre-obtained very wide fabric is heat-treated to obtain a sized very wide fabric. Then, in the calendering step, the sized very wide fabric is embedded in an elastomer base material to obtain a calendered very wide fabric. Subsequently, in the cutting step, the calendered, very wide fabric is cut into smaller pieces to obtain multiple narrow strips in which the woven filamentous hooping reinforcement elements extend in a direction substantially parallel to the maximum length direction of the strip.

[0011] Therefore, as explained above, until our discovery, it was believed that the sole function of the filamentous weft elements was to hold the woven filamentous hooping reinforcement elements relative to each other during various steps such as sizing, calendering, and cutting.

[0012] Once the important role of filamentous weft elements in the formation of oxidation pockets in prior art tires was found, the inventors subsequently proposed eliminating the transmission means formed by cotton filamentous weft elements and confirmed that oxidation pocket formation can be suppressed by filamentous weft elements (multiple) comprising as few monofilaments as possible and as few corrosive agent-transmitting fibers as possible, according to the present invention. Thus, the present invention teaches the use of organic and / or inorganic synthetic fibers and / or monofilaments that, by their very nature, transmit little to no moisture or corrosive agents, and in any case transmit far less than cotton.

[0013] In fact, organic and / or inorganic synthetic fibers and / or monofilaments have relatively low moisture content. Therefore, the or at least one filamentous weft element(s) generally has a moisture content of less than 5.0%, preferably 3.0% or less, and more preferably 2.0% or less. Moisture content is measured in accordance with the standard ASTM D 885 / D 885MA (January 2010, Section 10), defined as the ratio of the weight of moisture contained in the filamentous weft element to the dry weight of the filamentous weft element, expressed as a percentage, and equal to [(WM) / M]x100, where W is the weight in grams of the filamentous weft element exposed to a temperature of 23°C ± 2°C for 48 hours at a relative humidity of 50% ± 10%, in accordance with the standard ISO 23529 (2016), and M is the weight in grams of the filamentous weft element after oven drying.

[0014] In accordance with the present invention, the woven filamentous hooping reinforcement elements are connected to one or more filamentous weft elements. Therefore, the filamentous weft elements are woven together with the woven filamentous hooping reinforcement elements in contact with them, and each woven filamentous hooping reinforcement element is kept at a given distance from adjacent woven filamentous hooping reinforcement elements. The weaving of the woven filamentous hooping reinforcement elements and the filamentous weft elements defines the weaving method. A well-known weaving method is taffeta weave, also known as plain weave.

[0015] Textile fibers and monofilaments are generally classified into two main categories: natural fibers and monofilaments, and chemical fibers and monofilaments. Natural fibers and monofilaments include monofilaments and fibers of plant origin (especially cotton), animal origin, and mineral origin. Chemical fibers and monofilaments include man-made fibers and monofilaments, and synthetic fibers and monofilaments. Man-made fibers and monofilaments are manufactured from natural raw materials, including viscose, which is manufactured from wood cellulose in particular. Synthetic fibers and monofilaments include organic polymer fibers and monofilaments (e.g., polyester and polyamide), and also inorganic polymer fibers and monofilaments (e.g., glass and carbon).

[0016] Therefore, according to the present invention, the presence of natural monofilaments and natural fibers, as well as artificial monofilaments and artificial fibers, can be avoided as much as possible, preferably completely.

[0017] Each filamentous hooping reinforcing element is a woven fabric in the sense that it comprises one or more woven monofilaments and / or one or more woven fibers, preferably comprising woven monofilaments and / or one or more woven fibers, for at least 50% of its weight.

[0018] A monofilament is generally a very long, continuous, single filamentary element obtained by spinning from a molten material. A fiber is a short, single filamentary element. Multiple fibers are spun together to obtain a continuous yarn. Therefore, when an aggregate consists only of polymer synthetic fibers, or a combination of polymer synthetic monofilaments, the aggregate comprises one or more continuous yarns, each continuous yarn being formed from spun yarns (or aggregates) of these polymer synthetic fibers.

[0019] To improve the balance between the vibrational discomfort caused by oxidation pockets and the weight of the tire, and therefore its rolling resistance, the present invention proposes the use of filamentous weft elements that do not transmit or transmit very little corrosive agents, in order to reduce the thickness of the material(s) separating the bottom of the deepest cut in the axial center of the tread from the woven filamentous hooping reinforcement elements in the axial center of the tread. This thickness is represented by the mean radial distance E1. Thus, reducing the mean radial distance E1 increases the risk of corrosive agents reaching the hoop reinforcement, but the corrosive agent transmission by the filamentous weft elements(s) prevents an increase in the total surface area of ​​the oxidation pockets, or even reduces it.

[0020] Therefore, in the first compromise, which is an improvement over the prior art, it is possible to choose to significantly reduce the mean radial distance E1. This prevents an increase in the total surface area of ​​the oxidation pockets; although this surface area does not necessarily decrease, the tire becomes significantly lighter and therefore its rolling resistance decreases. In the second compromise, which is an improvement over the prior art, it is possible to choose to moderately reduce the mean radial distance E1. This reduces the total surface area of ​​the oxidation pockets, moderately reduces the weight of the tire, and moderately reduces its rolling resistance. Which compromise to choose will be determined by a person skilled in the art depending on the application of the tire.

[0021] The average radial distance E1 is determined for the axially central portion of the crown by measuring a plurality of radially distributed distances between surfaces along the width of the axially central portion of the crown in the axial direction. For example, the distance is measured every 1 centimeter in the axial direction starting from the end faces that axially divide the axially central portion of the crown. Of course, if the radially outermost point of the textile filament hoop reinforcing element is located radially outward of a surface passing through the radially innermost point of said or each deepest groove in the axially central portion of the tread and is substantially parallel to the tread surface, the measured radial distance is considered negative to account for the potential influence of corrosive agents. Conversely, and in most cases, if the radially outermost point of the textile filament hoop reinforcing element is located radially inward of a surface passing through the radially innermost point of said or each deepest groove in the axially central portion of the tread and is substantially parallel to the tread surface, the measured radial distance is considered positive.

[0022] These measurements are performed on a plurality of meridional sections equally distributed along the circumferential direction of the tire, for example, on four meridional sections. Thereafter, to obtain the average radial distance E1, the radial distances thus measured are averaged.

[0023] The radial distance between two surfaces means the linear distance between a point on one surface and its projection point onto the other surface in the radial direction of the tire.

[0024] The axially central portion of the tread is the axial portion of the tread corresponding to the axially central portion of the crown. The axially central portion of the crown and the axially central portion of the tread are axially bounded by the same first and second end faces, each of the first and second end faces is perpendicular to the axial direction of the tire, and passes through first and second points located at an axial distance equal to 25% of the width of the tread surface from the median plane of the tire.

[0025] Conventionally, the tread surface is determined for a tire mounted on a reference rim by inflating it to the nominal pressure (250 kPa or 290 kPa depending on whether it is a standard tire or a reinforced tire) in accordance with the European Tyre and Rim Technical Organisation (ETRTO) 2020 standard manual. When there is a clear boundary between the tread surface and the remaining part of the tire, the axial width of the tread surface can be easily measured. When the tread surface is continuous with the outer surface of the tire sidewall, the axial limit of the tread surface passes through a point where the angle formed by a tangent to the tread surface passing through this point and a straight line parallel to the axial direction passing through this point is equal to 30°. In a meridional section, when there are multiple points where the absolute value of the angle is equal to 30°, the radially outermost point is adopted.

[0026] Optionally and preferentially, the tire according to the present invention is for vehicles selected from passenger cars, light utility vehicles and camper vans, and more preferentially, the tire according to the present invention is for passenger cars.

[0027] Passenger car tires are passenger car tires or automobile tires as defined in the ETRTO 2020 Standard Manual. Such tires have a cross section characterized by a meridional section height H and a nominal section width SW, in accordance with the ETRTO 2020 Standard Manual. More preferably, and optionally, passenger car tires to which the present invention is advantageously applied have a ratio H / S expressed as a percentage that is at most equal to 90, preferably at most equal to 80, more preferably at most equal to 70, and further, at least equal to 20, preferably at least equal to 80, more preferably at least equal to 30, and a nominal section width SW that is at least equal to 115 mm, preferably at least equal to 155 mm, more preferably at least equal to 175 mm, and further, at most equal to 385 mm, preferably at most equal to 315 mm, more preferably at most equal to 285 mm. Furthermore, the rim flange diameter D, which defines the diameter of the rim for tire mounting, is equal to at least 12 inches, preferably at least 16 inches, and moreover, to a maximum of 24 inches, preferably to a maximum of 21 inches. The nominal section width SW, nominal aspect ratio H / S, and rim flange diameter D are indicated by size markings engraved on the tire sidewall in accordance with the ETRTO 2020 standard manual.

[0028] Tires for small utility vehicles or campervans are as specified in Sections 10-12 of the ETRTO 2020 standard manual, specifically the section on utility vehicle tires.

[0029] For new tires, the cut depth is the maximum radial distance between the bottom of the cut and its projection onto the ground during tire operation. The maximum cut depth is called the tread pattern height. In most tires, the deepest cut in the axial center of the tread is also the deepest cut in the tread and therefore defines the tread pattern height.

[0030] A notch refers to either a groove or a sipe, which forms an open space on the tread surface.

[0031] A sipe or groove has two main characteristic dimensions on the tread surface: width and curve length, such that the curve length is at least twice the width. Thus, the sipe or groove is defined by at least two main surfaces that determine its curve length and are connected at the bottom surface, and these two main surfaces are separated from each other by a non-zero distance called the width of the cut.

[0032] For new tires, the width of the notch is the maximum distance between two main sides, measured on the radial side coinciding with the tread surface if the notch is not chamfered, and between the outermost radial side of the notch and the radially inward side of the chamfered portion if the notch is chamfered. This width is measured substantially perpendicular to the main sides.

[0033] The axial width of the cut is measured along the axial direction of the tire, for example, in the meridional cross-section of the tire.

[0034] The distance between the main sides of the sipes is such that, especially when the tire is new and under normal driving conditions, including being under nominal load and nominal pressure, the main sides defining the sipes are at least partially in contact with the tread.

[0035] The grooves are designed so that, under normal driving conditions, including when the tire is under nominal load and nominal pressure, the distance between the main sides of the tire prevents these main sides from coming into contact with each other.

[0036] The cuts can be made in the lateral or circumferential direction.

[0037] A lateral cut is such that the cut extends in an average direction that forms an angle of more than 30°, preferably 45° or greater, with respect to the circumferential direction of the tire. The average direction is the shortest curve connecting the two ends of the cut and is parallel to the tread surface. A lateral cut can be continuous, that is, not interrupted by a tread pattern block or another cut, so that the two main sides determining its length are uninterrupted over the length of the lateral cut. Similarly, a lateral cut can be discontinuous, that is, interrupted by one or more tread pattern blocks and / or one or more other cuts, so that the two main sides determining its length are interrupted by one or more tread pattern blocks and / or one or more other cuts.

[0038] The circumferential cuts are designed to extend in an average direction that forms an angle of 30° or less, preferably 10° or less, with respect to the circumferential direction of the tire. The average direction is the shortest curve connecting the two ends of the cut and is parallel to the tread surface. If the circumferential cuts are continuous, the two ends coincide and are connected by a curve that goes around the entire circumference of the tire. The circumferential cuts can be continuous, that is, not interrupted by tread pattern blocks or other cuts, so that the two main sides that determine their length are uninterrupted around the entire circumference of the tire. Similarly, the circumferential cuts can be discontinuous, that is, interrupted by one or more tread pattern blocks and / or one or more other cuts, so that the two main sides that determine their length are interrupted around the entire circumference of the tire by one or more tread pattern blocks and / or one or more other cuts.

[0039] In the case of a circumferential cut located on the outer side of the midline of a tire, its side surfaces are called the axial inner surface and the axial outer surface, and the axial inner surface is positioned axially inward of the axial inner surface with respect to the midline at a given azimuth angle.

[0040] Each circumferential cut has an axial inner end and an axial outer end. Regardless of whether the circumferential cut has a chamfer or not, each axial inner end and outer end are located at the axial inner edge or outer edge, respectively.

[0041] In the case of a lateral cut, the sides are called the front and rear, and the front is the side whose edge enters the contact surface before the edge of the rear with respect to a given circumferential line.

[0042] In some embodiments, whether or not it is a principal circumferential cut, such or each circumferential cut is chamfered. The chamfer of a circumferential cut can be a straight chamfer or a rounded chamfer. A straight chamfer is formed by a flat surface inclined with respect to the axial inner and outer surfaces extending to the axial inner or outer edge that divides the circumferential cut axially. A rounded chamfer is formed by a curved surface extending tangentially into the axial inner or outer surface. The chamfer of a circumferential cut is characterized by a height and width equal to the radial distance and axial distance, respectively, between a point common to the axial inner or outer surface extended by the chamfer and the axial inner or outer edge that divides the circumferential cut axially.

[0043] In some embodiments, the transverse cuts or each transverse cut is chamfered. In other words, each transverse cut is defined radially by a front and rear surface that are connected to each other by a bottom surface that divides the transverse cut circumferentially and radially inward. The chamfer of the transverse cut can be a straight chamfer or a rounded chamfer. A straight chamfer is formed by a flat surface inclined with respect to the front and rear surfaces extending to the front or rear edge that divides the transverse cut circumferentially. A rounded chamfer is formed by a curved surface extending tangentially into the front or rear surface. The chamfer of the transverse cut is characterized by a height and width equal to the radial distance, the point common to the front or rear surface extended by the chamfer, and the distance perpendicular to the front or rear edge between the front or rear edge that divides the transverse cut circumferentially.

[0044] The tire according to the present invention has the shape of an annular body around an axis of rotational symmetry that substantially coincides with the axis of rotation of the tire. This axis of rotational symmetry defines three directions conventionally used by those skilled in the art: axial, circumferential, and radial.

[0045] The axial direction is understood to be the direction substantially parallel to the rotational axis of the tire or mounting assembly, i.e., the axis of rotation of the tire or mounting assembly.

[0046] The circumferential direction is understood to be a direction substantially perpendicular to both the axial direction and the radius of the tire or mounting assembly (in other words, a direction tangent to the circle around the axis of rotation of the tire or mounting assembly).

[0047] The radial direction is understood to be any direction along the radius of the tire or mounting assembly, that is, any direction that intersects with the axis of rotation of the tire or mounting assembly and is substantially perpendicular to that axis.

[0048] The midline of a tire (denoted as M) is understood to be a plane located midway between the two beads in the axial direction, passing through the axial center of the crown, and perpendicular to the tire's axis of rotation.

[0049] The tire's equatorial plane is understood to be the plane passing through the tire's equator, perpendicular to the median plane and radially in the meridional section. The tire's equator is the axis in the meridional section (a plane perpendicular to the circumferential direction and parallel to the radial and axial directions) that is parallel to the tire's axis of rotation and is equidistant between the radially outermost point of the tread intended to contact the ground and the radially innermost point of the tire intended to contact a support, such as the rim.

[0050] The meridional plane is understood to be a plane parallel to and containing the axis of rotation of a tire or mounting assembly, and perpendicular to the circumferential direction.

[0051] "Radially inward of ~" and "radially outward of ~" are understood to mean "closer to the tire's axis of rotation than ~" and "further from the tire's axis of rotation than ~," respectively. "Axially inward of ~" and "Axially outward of ~" are understood to mean "closer to the tire's midline than ~" and "further from the tire's midline than ~," respectively.

[0052] The bead is understood to be the portion of the tire intended to allow it to be mounted to a mounting support, such as a wheel with a rim. Therefore, each bead is intended to be in contact with the flange of the rim, in particular, to enable the tire to be mounted.

[0053] A carcass layer or working layer is understood to be a layer having continuous filamentous reinforcing elements from one edge to the other. Therefore, a carcass layer or working layer can be folded back within the tire to form twice the thickness of that layer. Two different carcass layers or working layers have discontinuous filamentous reinforcing elements from one layer to the other. Two superimposed carcass layers or working layers form a thickness equal to the sum of the thicknesses of the two carcass layers or working layers.

[0054] The expression "between a and b" indicates a range of values ​​that extends from greater than a to less than b (i.e., excluding the endpoints a and b), whereas the expression "from a to b" indicates a range of values ​​that extends from a to b (i.e., including the exact endpoints a and b).

[0055] The characteristics of the woven filamentous hooping reinforcement elements and filamentous weft elements (multiple elements) can be determined, for example, by extracting these elements from a tire in accordance with a process compliant with standard ASTM D885 / D885M-10a-6.4.

[0056] Unless otherwise specified, the geometric characteristics of a tire are measured for an unloaded, uninflated tire, or, if possible, in the tire cross-section within the midline plane.

[0057] **In this case,** or each filamentous weft element is composed of woven monofilaments and / or woven fibers, selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic fibers and monofilaments, and aggregates of these monofilaments and fibers, at least 50%, preferably at least 75%, and more preferably 100%, of the weight of the or each filamentous weft element.

[0058] In the said or each filamentous weft element, the risk of corrosive agent transmission can be reduced by maximizing the weight ratio of monofilaments and / or fibers that do not transmit corrosive agents.

[0059] The weight ratio of the monofilament and fiber in question is determined by measuring the weight of the filamentous weft element, and then separating the monofilament and fiber in question and measuring their respective weights. The ratio of the two weights is equal to the resulting weight ratio.

[0060] Optionally and advantageously, at least 50%, preferably at least 75%, and more preferably 100%, of the cumulative length of the filamentous weft element(s) comprises a plurality of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic woven fibers and monofilaments, and aggregates thereof. By maximizing the length of filamentous weft elements that do not transmit corrosive agents, the risk of corrosive agent transmission can be reduced.

[0061] The ratio of the cumulative length of the target filamentous weft element(s) is determined by measuring the cumulative length of the filamentous weft element(s) over a representative portion of the tire, and, if necessary, over the entire tire, and then measuring the cumulative length of the target filamentous weft element(s). The ratio of the two cumulative lengths is equal to the ratio of the obtained cumulative lengths.

[0062] In any embodiment that maximizes tire weight reduction, E1 ≤ 1.80 mm, preferably E1 ≤ 1.50 mm, more preferably E1 ≤ 1.40 mm, and even more preferably E1 ≤ 1.20 mm.

[0063] Optionally, E1 ≥ 0.20 mm, preferably E1 ≥ 0.50 mm, and more preferably E1 ≥ 1.00 mm. The presence of a non-zero material thickness makes it possible to protect the woven filamentous hooping reinforcement elements from excessive attack and excessive penetration into the crown reinforcement body.

[0064] Optionally and advantageously, the filamentous weft element(s) or at least one thereof comprises a plurality of organic polymer synthetic fabric fibers and / or monofilaments. Such monofilaments and fibers are particularly inexpensive.

[0065] Optionally and preferentially, at least 50%, preferably at least 75%, and more preferably 100%, of the weight of the or each filamentous weft element is composed of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments. In other words, if 100% of the weight of the or each filamentous weft element is composed of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments, then the or each filamentous weft element is composed of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments. In this case, the or each filamentous weft element does not contain natural monofilaments, natural fibers, artificial monofilaments and artificial fibers. The weight ratio is determined as described above.

[0066] Optionally and advantageously, at least 50%, preferably at least 75%, and more preferably 100%, of the cumulative length of the filamentous weft element(s) comprises multiple organic polymer synthetic fibers and / or monofilaments. The percentage of the cumulative length is determined as described above.

[0067] In one optional and advantageous embodiment, the organic polymer synthetic fiber and monofilament is selected from polyester fibers and monofilaments, polyamide fibers and monofilaments, polyketone fibers and monofilaments, polyurethane fibers and monofilaments, acrylic fibers and monofilaments, polyolefin fibers and monofilaments, polyetherketone fibers and monofilaments, as well as aggregates of these monofilaments and aggregates of these fibers, preferably selected from polyester fibers and monofilaments, polyamide fibers and monofilaments, as well as aggregates of these monofilaments and aggregates of these fibers, with a more favorable selection being organic synthetic fibers and monofilaments, which are polyester fibers and monofilaments. Among polyesters, PET (poly(ethylene terephthalate)), PEN (poly(ethylene naphthalate)), and PEF (polyethylene-2,5-flangecarboxylate) are preferred, with PET being particularly preferred. Among polyamides, aliphatic polyamides and aromatic polyamides are preferred, with aliphatic polyamides being particularly preferred.

[0068] In some optional and preferred embodiments, at the axial center of the crown, -The radial inner surface passing through the innermost radial point of the radially innermost woven filamentous hooping reinforcing element among the woven filamentous hooping reinforcing elements, -The radial outer surface passing through the radially outermost point of the metal filament-like working reinforcing element of the radially outermost working layer of the working reinforcement, The average radial distance E2 between them is E2 ≤ 0.40 mm, preferably E2 ≤ 0.30 mm, and more preferably E2 ≤ 0.20 mm.

[0069] In fact, to improve the compromise between the vibrational discomfort caused by oxidation pockets and the weight of the tire, these embodiments also propose using filamentous lath elements that do not transmit corrosive agents, or transmit only a small amount, to reduce the thickness of the material separating the bottom of the deepest cut in the axial center of the tread from the woven filamentous hooping reinforcing elements in the axial center of the tread, as well as the metal filamentous working reinforcing elements of the radially outermost working layer (and therefore the layer radially closest to the woven filamentous hooping reinforcing elements in the axial center of the tread). This thickness is expressed by the mean radial distance E2. Therefore, similar to E1, reducing the mean radial distance E2 that separates the radially outermost working layer from the hoop reinforcement increases the risk of corrosive agents reaching the radially outermost working layer. However, the filamentous weft elements (multiple) prevent corrosive agent transmission, thus preventing an increase in the total surface area of ​​oxidation pockets, or even reducing it.

[0070] Similar to what was described for E1, the first compromise, which is an improvement over the prior art, allows for a significant reduction in the mean radial distance E2. This prevents an increase in the total surface area of ​​oxidation pockets (though it does not necessarily decrease), while significantly reducing the tire's weight. The second compromise, which is an improvement over the prior art, allows for a moderate reduction in the mean radial distance E2. This reduces the total surface area of ​​oxidation pockets and moderately reduces the tire's weight. The choice of which compromise to select will be determined by a person skilled in the art, depending on the tire's application.

[0071] The mean radial distance E2 is determined in the same way as the mean radial distance E1, with the necessary modifications.

[0072] In the first modified example, E2 ≥ 0.05 mm, preferably E2 ≥ 0.10 mm. The presence of a non-zero material thickness prevents direct contact between the woven filamentous hooping reinforcing element and the metal filamentous working reinforcing element, thus preventing excessive propagation of corrosive agents from the hoop reinforcing element to the working reinforcing element. Furthermore, such a non-zero thickness ensures mechanical separation between the working reinforcing element and the hoop reinforcing element.

[0073] In the second modification, E2 < 0.05 mm. Unlike the first modification, the objective here is to minimize, or even eliminate, the thickness of the material in order to bring the woven filamentous hooping reinforcing element into direct contact with the metal filamentous working reinforcing element. While corrosive agents can propagate on metal filamentous working reinforcing elements that intersect with the woven filamentous hooping reinforcing element(s) that may transmit these corrosive elements, the filamentous weft reinforcing element(s) of the present invention reduces, or even eliminates, corrosive agent propagation on metal filamentous working reinforcing elements that do not intersect with the woven filamentous hooping reinforcing element(s) that transmit the corrosive agent.

[0074] In some possible but non-limiting embodiments, whether in the first or second modification, at least one of the woven filamentous hooping reinforcing elements is in contact with at least one of the metallic filamentous working reinforcing elements of the radially outermost working layer. As described above, contact between the woven filamentous hooping reinforcing elements and at least one of the metallic filamentous working reinforcing elements results only in limited propagation of the corrosive agent in the working reinforcement, thanks to the filamentous weft reinforcing elements(s) of the present invention.

[0075] In some optional embodiments, at the axial center of the crown, - A surface that passes through the innermost radial point of the deepest cut in the axial center of the tread, and is substantially parallel to the tread surface, -The radial outer surface passing through the radially outermost point of the metal filament-like working reinforcing element of the radially outermost working layer of the working reinforcement, The average radial distance H between them is H ≤ 3.00 mm, preferably H ≤ 2.75 mm, more preferably H ≤ 2.50 mm, and even more preferably H ≤ 2.35 mm.

[0076] By making the value of E1 relatively small, and optionally, relatively small, the mean radial distance H can be reduced if desired, and thus the tire can be made lighter. In another embodiment, by reducing E1 and optionally reducing E2, the height of the tread pattern can be increased to maintain a relatively high H value, and in particular, to increase the number of kilometers the tire can travel.

[0077] In one embodiment, the hoop reinforcement comprises a strip that is axially divided by two axial edges and spirally wound over a plurality of circumferential windings so as to extend axially between the axial edges.

[0078] In the first modification of this embodiment, the strip is spirally wound over multiple circumferential windings such that, in the axial central portion of the crown, two adjacent circumferential windings of the strip do not overlap each other in the axial and radial directions. Therefore, when the strip has two longitudinal axial edges, in the axial central portion of the crown, the adjacent longitudinal axial edges of two adjacent circumferential windings are adjacent to each other axially without forming an axial or radial overlap, that is, they are axially separated from each other without forming an axial or radial overlap between the two circumferential windings. This prevents the formation of a double thickness in the hoop reinforcement. When the adjacent longitudinal axial edges of two adjacent circumferential windings are axially separated from each other, this improves the balance between high-speed durability and tire weight by increasing the wrapping in the high-speed, more sensitive portion, i.e., the axially outer portion of the axial central portion, and decreasing the wrapping in the high-speed, less sensitive portion, i.e., the axial central portion.

[0079] In a second modification of this embodiment, two adjacent circumferential windings form an axial and radial overlap between them in the axial center of the crown. In this second modification, the strip windings overlap each other in the manner of roof tiles and are therefore generally referred to as "lapping".

[0080] To make tire manufacturing as efficient as possible, the strips are substantially parallel to one another and comprise multiple woven filament-like hooping reinforcing elements embedded in a polymer matrix, preferably an elastomer matrix.

[0081] Advantageously, each woven filamentous hooping reinforcement element extends in the main hooping direction, forming an angle with the circumferential direction of the tire that is 10° or less in absolute terms, preferably 7° or less, and more preferably 5° or less.

[0082] In one advantageous embodiment, the woven filamentous hooping reinforcement elements are connected to one another by a plurality of filamentous weft elements that are substantially parallel to each other in the main weft direction, which is not collinear with the main hooping direction.

[0083] Optionally, the main weft direction forms an angle of 45° or more, preferably 75° or more, with respect to the main hooping direction.

[0084] To manufacture the hoop reinforcement and strip of the above-described embodiment, a strip is manufactured which, when spirally wound around a working reinforcement, forms the hoop reinforcement. In the step of manufacturing a very wide fabric, woven filamentary hooping reinforcement elements are arranged substantially parallel to each other. Next, the woven filamentary hooping reinforcement elements are separated into a first ply and a second ply of woven filamentary hooping reinforcement elements.

[0085] Next, the woven filamentous hooping reinforcement elements are connected to each other by one or more filamentous weft elements that extend across the entire width of the very wide fabric. For this purpose, the filamentous weft elements are woven alternately with the woven filamentous hooping reinforcement elements of the first ply and the second ply of the filamentous warp elements.

[0086] In the subsequent sizing step, the woven filamentous hooping reinforcing elements and filamentous weft elements are covered with one or more layers of one or more adhesive compositions, and then the previously obtained very wide fabric is heat-treated to obtain a sized very wide fabric.

[0087] Subsequently, in the calendering step, a very wide piece of fabric, sized to the desired dimensions, is embedded in an elastomer base material to obtain a calendered, very wide piece of fabric.

[0088] Next, in the cutting step, the calendered, very wide fabric is cut into small pieces to obtain multiple narrow strips in which the woven filamentous hooping reinforcement elements extend in a direction substantially parallel to the maximum length direction of the strip.

[0089] It should be noted that in some embodiments, during the step in which the woven filamentous hooping reinforcement elements are connected to one or more filamentous weft elements, shuttleless looms, such as projectile looms, looms with flexible or rigid rapiers, or fluid jet looms may be used. In the case of fluid jet looms, air jet looms combined with tufted filamentous weft elements will be used to great advantage. Tufted filamentous weft elements are understood to be filamentous elements having monofilaments, fibers, or yarns that do not remain within the circumscribed circle of the theoretical filamentous element corresponding to the filamentous weft element, from which the monofilaments, fibers, or yarns that do not remain within that circle have been removed. Tufted filamentous weft elements mean that the filamentous weft elements are neither smooth nor textured, as described in International Publication No. 2015 / 016791.

[0090] In another embodiment, a shuttle loom that does not specifically require tufted filament weft elements can be used.

[0091] In some embodiments, each woven filament hooping reinforcement element comprises one or more organic synthetic monofilaments, preferably an aggregate comprising multiple organic synthetic monofilaments. Thus, the woven filament hooping elements do not transmit corrosive agents, and the propagation of these corrosive agents along woven filament hooping elements positioned in close proximity to or in contact with the attack is prevented as much as possible.

[0092] Optionally, the organic polymer synthetic monofilament is selected from polyester monofilament, aliphatic polyamide monofilament, aromatic polyamide monofilament, polyketone monofilament, and aggregates of these monofilaments, preferably from polyester monofilament, aliphatic polyamide monofilament, aromatic polyamide monofilament, and aggregates of these monofilaments, and more preferably from polyester monofilament, aliphatic polyamide monofilament, aggregates of aliphatic polyamide monofilament, and aggregates of aromatic polyamide monofilament. Among polyesters, PET (poly(ethylene terephthalate)), PEN (poly(ethylene naphthalate)), and PEF (polyethylene-2,5-flangecarboxylate) are preferred, with PET being particularly preferred. Among aliphatic polyamides, 6 or 6,6 aliphatic polyamides are preferred. Among aromatic polyamides, poly(metaphenylene isophthalamide) and poly(paraphenylene terephthalamide) are preferred.

[0093] In some embodiments, the working layer or each working layer is axially separated by two axial edges of the working layer and comprises metal filament-like working reinforcement elements that extend substantially parallel to each other in the axial direction from one axial edge to the other axial edge of the working layer.

[0094] Optionally, regardless of the configuration of the working reinforcement, each metal filamentary working reinforcement element extends along the circumferential direction of the tire and along the principal direction, forming an angle in absolute value that is strictly greater than 10°, preferably in the range of 15° to 50°, and more preferably in the range of 20° to 35°.

[0095] In the first configuration of the working reinforcement, the working reinforcement comprises a radially inner working layer and a radially outer working layer positioned radially outside the radially inner working layer. In this modified example, the main directions in which each filamentous working reinforcement element of the radially innermost working layer extends, and the main directions in which each filamentous working reinforcement element of the radially outermost working layer extends, form angles opposite to the circumferential direction of the tire. These angles may have the same or different absolute values.

[0096] In the second configuration of the working reinforcement, the working reinforcement comprises a single working layer. In this second configuration, therefore, the radially outermost working layer is the only working layer. The presence of a single working layer makes it possible to lighten the tire, in particular, and as a result, it is possible to reduce the energy dissipated by crown hysteresis and thus reduce the rolling resistance of the tire. Thus, the working reinforcement does not have a layer reinforced with filamentous reinforcing elements apart from this working layer. Filamentous reinforcing elements of such reinforcing layers that have been excluded from the working reinforcement of the tire include metal filamentous reinforcing elements and woven filamentous reinforcing elements. Very preferably, the working reinforcement consists of a single working layer.

[0097] In one embodiment that enables a reduction in the weight of metal filamentary working reinforcement elements, each metal filamentary working reinforcement element in the working layer or in each working layer is composed of a metal monofilament.

[0098] If the tire optionally comprises two beads, two sidewalls connecting each bead to the crown, and carcass reinforcements fixed to each bead, the carcass reinforcements extend radially within each sidewall and axially within the radially inward direction of the crown reinforcements.

[0099] In the first configuration of the carcass reinforcement, the carcass reinforcement comprises a single carcass layer. In this first configuration, apart from the single carcass layer, the carcass reinforcement does not have any layers reinforced with filamentous reinforcing elements. The filamentous reinforcing elements of such reinforcing layers excluded from the tire carcass reinforcement comprise metallic filamentous reinforcing elements and woven filamentous reinforcing elements. In very preferential terms, the carcass reinforcement consists of a single carcass layer.

[0100] In the second configuration of the carcass reinforcement, the carcass reinforcement comprises two carcass layers. In this second configuration, it is preferable that the main directions of the filamentous carcass reinforcement elements of the two carcass layers are substantially parallel to each other.

[0101] Advantageously, if the carcass reinforcement comprises at least one carcass layer, the or each carcass layer comprises a woven filament-like carcass reinforcement element that is axially separated by two axial edges of the or each carcass layer and extends axially from one axial edge to the other axial edge of the or each carcass layer.

[0102] In a first modified carcass reinforcement that can be used in combination with the first and second configurations of the carcass reinforcement and in combination with the first and second configurations of the working reinforcement, each filamentous carcass reinforcement element extends in the principal direction of each filamentous carcass reinforcement element, which is substantially constant between each axial edge of the carcass layer and forms an angle with the circumferential direction of the tire of 60° or more in absolute value, preferably in the range of 80° to 90°.

[0103] In a second modified carcass reinforcement that can be used in combination with the first and second configurations of the carcass reinforcement, and in combination with a working reinforcement having a single working layer, each filamentous carcass reinforcement element is in the circumferential direction of the tire and -At the axial center of the carcass layer, which extends axially parallel to the working layer in the radial direction, the angle is strictly less than 80° in absolute terms. - Between the axial center of the carcass layer and each axial edge, the angle is in the range of 80° to 90° in absolute terms, in the two axial sides of the carcass layer that extend in the axial and radial directions. Each filamentous carcass reinforcing element extends in the main direction.

[0104] The present invention will be better understood by reading the following description, which is given in conjunction with the drawings as merely a non-limiting example. [Brief explanation of the drawing]

[0105] [Figure 1] This is a meridional cross-sectional view of a tire according to a first embodiment of the present invention. [Figure 2] Figure 1 is a schematic fractured view of the tire, showing the arrangement of filamentous reinforcing elements within the crown. [Figure 3] Figure 1 is a top view of the tire tread. [Figure 4] Figure 1 is a detailed view of the axial center of the tire crown. [Figure 5] Figure 1 shows the hoop reinforcement for the tire. [Figure 6]Figure 5 shows photographs of the filamentous weft and woven filamentous hooping reinforcement elements related to the hoop reinforcement. [Figure 7] This is a diagram of a tire according to a second embodiment, similar to those in Figures 1 and 4. [Figure 8] This is a diagram of a tire according to a second embodiment, similar to those in Figures 1 and 4. [Figure 9] This is a diagram of a tire according to a third embodiment, similar to Figure 4. [Figure 10] This is a diagram of a tire according to a third embodiment, similar to Figure 5. [Figure 11] This is a diagram similar to Figure 9 of a tire according to the fourth embodiment. [Figure 12] This is a diagram similar to Figure 10 of a tire according to the fourth embodiment. [Modes for carrying out the invention]

[0106] The reference frames X, Y, and Z, corresponding to the normal axial (Y), radial (Z), and circumferential (X) directions of the tire, are shown in the figure.

[0107] Figures 1 to 6 show a tire according to the present invention, denoted by the general reference symbol 10. The tire 10 has a substantially annular shape around a rotation axis substantially parallel to the axial direction Y. The tire 10 is for passenger cars and has a size of 225 / 45R17. In various figures, the tire 10 is depicted as new, i.e., unused.

[0108] The tire 10 includes a crown 12 which includes a tread 14 that supports a tread surface intended to contact the ground during its travel. The tread surface 15 is axially divided by first and second axial ends 151, 152 passing through points N located on either side of the central plane M, in which case the angle between the tangent T to the tread surface 15 passing through these points and a straight line R parallel to the axial direction Y is equal to 30°. The tread surface 15 has an axial width L measured as the axial distance from the first axial end 151 to the second axial end 152. The crown 12 includes an axial center P0 and two axial sides P1 and P2 located on either side of the axial center with respect to the central plane M.

[0109] The axial central portion P0 extends axially over an axial width L0 equal to 50% of the axial length L of the tread surface 15. The first and second axial side portions P1 and P2 each have axial widths L1 and L2 equal to 25% of the axial length L of the tread surface 15. The axial central portion P0 is positioned with the median plane M as its axial center.

[0110] Referring to Figures 1, 3, and 4, the tread 14 is provided with cuts including main circumferential cuts 72, 74, 76, 78, secondary circumferential cuts 80, 82, 84, and transverse cuts 90, 92, 94, 96, 98. The main circumferential cuts 72, 74, 76, 78 are circumferential grooves.

[0111] Referring to Figure 4, each main circumferential cut 72, 74, 76, 78 comprises two sides Fr1, Fr2 and a bottom surface Frd. Each main circumferential cut 72, 74, 76, 78 has a depth He ranging from 4.00 mm to the tread pattern height Hs, preferably from 5.00 mm to the tread pattern height Hs, and more preferably from 5.50 mm to the tread pattern height Hs. Each depth is at least 50% of the tread pattern height Hs, where Hs = 6.50 mm, and each main circumferential cut 74, 76 has a depth equal to He = Hs = 6.50 mm, and each main circumferential cut 72, 78 has a depth equal to 6.00 mm. Thus, each main circumferential cut 74, 76 is the deepest cut of the tire 10, particularly in the axial center P0.

[0112] The crown 12 also includes a crown reinforcement 16 extending circumferentially in the X direction within its interior. The tire 10 also includes a sealing layer 18 that is airtight to the expansion gas and is intended to define an internal cavity closed by the mounting support of the tire 10 once the tire 10 is mounted to a mounting support, such as a rim.

[0113] The crown reinforcement 16 comprises a working reinforcement 20 and a hoop reinforcement 22.

[0114] The working reinforcement 20 comprises two working layers 24 and 26. The radially outer working layer 26 is located radially outward from the radially inner working layer 24. Therefore, the radially outer working layer 26 is the radially outermost working layer of the working reinforcement 20.

[0115] The hoop reinforcement 22 comprises at least one hooping layer, in this case one hooping layer 28.

[0116] The crown reinforcement 16 is radially covered by the tread 14. Here, the hoop reinforcement 22, in this example the hooping layer 28, is positioned radially outward of the working reinforcement 20 and radially inward of the tread 14. Therefore, the hoop reinforcement 22 is sandwiched radially between the working reinforcement 20 and the tread 14.

[0117] The tire 10 has two sidewalls 30 that extend radially inward from the crown 12. The tire 10 further has two beads 32 radially inward from the sidewalls 30. Each sidewall 30 connects each bead 32 to the crown 12.

[0118] The tire 10 includes carcass reinforcements 34 fixed to each bead 32, which in this example are wound around bead wires 33. The carcass reinforcements 34 extend radially in each sidewall 30, axially in the crown 12, and radially inward of the crown reinforcements 16. The crown reinforcements 16 are positioned radially between the tread 14 and the carcass reinforcements 34. The carcass reinforcements 34 comprise at least one carcass layer, which in this example comprises a single carcass layer 36. In this example, the carcass reinforcements 34 consist of a single carcass layer 36.

[0119] Referring to Figure 4, each working layer 24, 26, hooping layer 28, and carcass layer 36 comprises a polymer matrix, in this case an elastomer matrix in which one or more filamentous reinforcing elements of the corresponding layer are embedded. The interfaces of two different adjacent layers are depicted by dotted lines. These layers will now be described with reference to Figures 2 to 5.

[0120] The hoop reinforcement 22, in this example the hooping layer 28, is axially separated by two axial edges 221 and 222 of the hoop reinforcement 22. The hoop reinforcement 22 comprises a strip 40 that is helically wound over a plurality of circumferential windings Ci so as to extend axially between its axial edges 221 and 222.

[0121] Figure 5 shows several windings C1 to C4, which are located at the axial center P0 of the crown. The strip 40 comprises several textile filamentary hooping reinforcing elements 220, which are substantially parallel to each other and embedded in the elastomer matrix of the hooping layer 28, and the textile filamentary hooping reinforcing elements 220 are wound radially spirally around the working reinforcing body 20. The strip 40 is wound spirally over multiple circumferential windings Ci at the axial center P0 of the crown 12 such that two adjacent circumferential windings Ci of the strip 40 do not overlap each other in the axial and radial directions. Therefore, as can be seen in Figure 5, in the axial center P0 of the crown 12, there is no radial overlap between one of the woven filament hooping reinforcing elements of one circumferential winding Ci of the strip 40 and one of the woven filament hooping reinforcing elements of the circumferential winding Cj adjacent to the circumferential winding Ci.

[0122] Each woven filament hooping reinforcement element 220 extends in the main hooping direction D0, forming an angle AF with the circumferential direction X of the tire 10, which is 10° or less in absolute terms, preferably 7° or less, and more preferably 5° or less. In this example, AF = -5°. The strip 40 has a density of woven filament hooping reinforcement elements of 120 per decimeter of the strip 40, and this density is measured in a direction perpendicular to the direction D0.

[0123] Within the strip 40, the woven filamentous hooping reinforcement elements 220 are connected to one another by a plurality of filamentous weft elements 42 that are substantially parallel to each other in the main weft direction DT, which is not collinear with the main hooping direction D0. The filamentous weft elements 42 are discontinuous to each other. The main weft direction DT forms an angle with the main hooping direction D0 of 45° or more, preferably 75° or more, and in this example, substantially equal to 90°.

[0124] The radially inner working layer 24 is axially separated by two axial edges 241 and 242. The radially inner working layer 24 includes metal filament-like working reinforcement elements 240 that extend axially from axial edge 24A to the other axial edge 24B in a manner substantially parallel to each other in the principal direction D1. Similarly, the radially outer working layer 26 is axially separated by two axial edges 261 and 262. The radially outer working layer 26 includes metal filament-like working reinforcement elements 260 that extend axially from axial edge 261 to the other axial edge 262 in a manner substantially parallel to each other in the principal direction D2. The principal direction D1 from which each filament-like working reinforcement element 240 of the radially inner working layer 24 extends, and the principal direction D2 from which each filament-like working reinforcement element 260 of the radially outer working layer 26 extends, form angles AT1 and AT2, respectively, opposite to the circumferential direction X of the tire 10. Each principal direction D1 and D2 forms angles AT1 and AT2 with the circumferential direction X of the tire 10, respectively, which are in absolute value strictly greater than 10°, preferably in the range of 15° to 50°, and more preferably in the range of 20° to 35°. In this example, AT1 = -26° and AT2 = +26°.

[0125] The carcass layer 36 is axially separated by two axial edges 361 and 362. The carcass layer 36 is provided with carcass filament-like reinforcing elements 360 that extend axially from one axial edge 361 to the other axial edge 362 in the main direction D3, which forms an angle AC with the circumferential direction X of the tire 10. This angle AC is substantially constant between the axial edges 361 and 362 and is in the range of 60° or more in absolute value, preferably between 80° and 90°, in this example AC = +90°.

[0126] Figure 6 shows a cross-sectional view of the hoop reinforcement 22 in a cross-section perpendicular to direction D0 and including one of the filamentous weft elements 42. Referring to Figure 6, each filamentous hooping reinforcement element 220 comprises one or more organic synthetic monofilaments, preferably an aggregate comprising multiple organic synthetic monofilaments. The organic polymer synthetic monofilaments are selected from polyester monofilaments, aliphatic polyamide monofilaments, aromatic polyamide monofilaments, polyketone monofilaments, and aggregates of these monofilaments, preferably selected from polyester monofilaments, aliphatic polyamide monofilaments, aromatic polyamide monofilaments, and aggregates of these monofilaments, and more preferably selected from polyester monofilaments, aliphatic polyamide monofilaments, aggregates of aliphatic polyamide monofilaments, and aggregates of aromatic polyamide monofilaments. In this case, each filamentous hooping reinforcement element 220 conventionally comprises two multifilament yarns, each multifilament yarn consisting of a monofilament yarn of aliphatic polyamide, in this example nylon, with a count equal to 94tex, and these two multifilament yarns are individually twisted spirally at 320 turns per meter and then twisted together spirally in the opposite direction at 320 turns per meter. These two multifilament yarns are then spirally wound around each other. As a variation, a hooping filament reinforcing element can be used, comprising one multifilament yarn consisting of aliphatic polyamide, in this case nylon monofilament yarn with a count equal to 140 tex, and one multifilament yarn consisting of aromatic polyamide, in this case aramid monofilament yarn with a count equal to 167 tex. These two multifilament yarns are individually twisted spirally in one direction at 290 turns per meter, and then twisted together spirally in the opposite direction at 290 turns per meter. These two multifilament yarns are then spirally wound around each other. This variation results in AT1 = -29° and AT2 = +29°.

[0127] Still referring to Figure 6, each filamentous weft element 42 comprises a plurality of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic fibers and monofilaments, and aggregates of these monofilaments and fibers. More specifically, at least 50%, preferably at least 75%, here 100%, of the weight of each filamentous weft element 42 is composed of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic fibers and monofilaments, and aggregates of these monofilaments and fibers. Furthermore, at least 50%, preferably at least 75%, here 100%, of the cumulative length of the filamentous weft element 42 comprises a plurality of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic woven fibers and monofilaments, and aggregates of these monofilaments and fibers.

[0128] At least one of the filamentous weft elements 42 comprises a plurality of organic polymer synthetic woven fibers and / or monofilaments. More specifically, at least 50%, preferably at least 75%, here 100%, of the weight of each filamentous weft element 42 is composed of woven monofilaments and / or woven fibers selected from organic polymer synthetic fibers and monofilaments. Furthermore, at least 50%, preferably at least 75%, here 100%, of the cumulative length of the filamentous weft element 42 comprises a plurality of organic polymer synthetic fibers and / or monofilaments.

[0129] Organic polymer synthetic fibers and monofilaments are selected from polyester fibers and monofilaments, polyamide fibers and monofilaments, polyketone fibers and monofilaments, polyurethane fibers and monofilaments, acrylic fibers and monofilaments, polyolefin fibers and monofilaments, polyetherketone fibers and monofilaments, as well as aggregates of these monofilaments and aggregates of these fibers, preferably selected from polyester fibers and monofilaments, polyamide fibers and monofilaments, as well as aggregates of these monofilaments and aggregates of these fibers, where the organic synthetic fibers and monofilaments are polyester fibers and monofilaments.

[0130] In this example, each filamentous weft element 42 comprises two twisted yarns, each including a core and a layer covering the core, where the core comprises multiple polyester monofilaments and the layer comprises multiple polyester fibers. The sum of the yarn counts of each filamentous weft element 42 is equal to 22 tex. The yarn count of each filamentous weft element 42 ranges from 1 tex to 20 tex, preferably from 10 tex to 15 tex. Here, it is 11 tex. To produce each filamentous weft element 42, the two twisted yarns are wound spirally around each other with a twist of 1100 turns per meter, in which case each filamentous weft element 42 has a twist of equal to 1100 turns per meter. The moisture content of each filamentous weft element 42 is equal to 1.8%.

[0131] The density of the filamentous weft elements 42 is 3.0 to 8.0 filamentous weft elements per dm of strip length 40, preferably 3.0 to 6.0 filamentous weft elements per dm of strip length 40, and more preferably 3.0 to 5.5 filamentous weft elements per dm of strip length 40. Here, the density of the filamentous weft elements 42 is equal to 5.0 filamentous weft elements per dm of strip length 40.

[0132] Each metal filamentary working reinforcement element 240,260 is an assembly of two steel monofilaments wound spirally at a pitch of 14 mm, with each steel monofilament having a diameter of 0.30 mm. For clarity, Figure 4 shows a circle circumscribing this assembly, the diameter of which is equal to the diameter of each metal filamentary working reinforcement element 240,260. In one variation, each metal filamentary working reinforcement element 240,260 is composed of steel monofilaments having a diameter of 0.30 mm. More generally, the steel monofilaments have diameters ranging from 0.25 mm to 0.32 mm. In yet another variation, it is also possible to use an assembly of six steel monofilaments, each having a diameter of equal to 0.23 mm and comprising an inner layer of two monofilaments spirally wound together at a pitch of 12.5 mm in a first direction, for example, the Z direction, and an outer layer of four monofilaments spirally wound around the inner layer at a pitch of 12.5 mm in a second direction opposite to the first direction, for example, the S direction.

[0133] Each filamentous carcass reinforcement element 360 conventionally comprises two multifilament yarns, each multifilament yarn composed of a polyester monofilament, in this example, PET. These two multifilament yarns are individually twisted spirally in one direction at 240 turns per meter, and then twisted together spirally in the opposite direction at 240 turns per meter. Each of these multifilament yarns has a count equal to 220 tex. Other variations may utilize a count equal to 144 tex and a twist equal to 420 turns per meter, or a count equal to 334 tex and a twist equal to 270 turns per meter.

[0134] Figure 4 shows - A surface 100 that passes through the innermost radial points of each of the deepest cuts 74, 76 in the axial center P0 of the tread 14 and is substantially parallel to the tread surface 15, -The radial outer surface 102 passing through the radially outermost point of the woven filamentous hooping reinforcing element 220 that is the outermost in the radial direction among the woven filamentous hooping reinforcing elements 220, -The radial inner surface 104 passing through the radially innermost point of the woven filamentous hooping reinforcing element 220 that is the innermost in the radial direction among the woven filamentous hooping reinforcing elements 220, -The radial outer surface 106 passing through the radial outermost point of the metal filament-like working reinforcing element 260 of the radial outermost working layer 26 of the working reinforcing body 20, This indicates.

[0135] At the axial center P0 of the crown 12, the average radial distance E1 between the surface 100 and the radial outer surface 102 is E1 ≤ 2.00 mm. Here, E1 ≤ 1.80 mm, preferably E1 ≤ 1.50 mm. Furthermore, E1 ≥ 0.20 mm, preferably E1 ≥ 0.50 mm, and more preferably E1 ≥ 1.00 mm. In this example, E1 = 1.50 mm.

[0136] At the axial center P0 of the crown 12, the average radial distance E2 between the radial inner surface 104 and the radial outer surface 106 is E2 ≤ 0.40 mm, preferably E2 ≤ 0.30 mm. Furthermore, E2 ≥ 0.05 mm, preferably E2 ≥ 0.10 mm. In this example, E2 = 0.23 mm.

[0137] At the axial center P0 of the crown 12, the average radial distance H between the surface 100 and the radially outer surface 106 is H ≤ 3.00 mm, preferably H ≤ 2.75 mm, more preferably H ≤ 2.50 mm, and even more preferably H ≤ 2.35 mm. In this example, H = 2.34 mm.

[0138] Here, the tire according to the second embodiment will be described with reference to Figures 7 and 8. Elements similar to those in the first embodiment are denoted by the same reference numerals.

[0139] Unlike the tire according to the first embodiment, the working reinforcement 20 of the tire 10 according to the second embodiment comprises a single working layer 26, which is therefore the radially outermost working layer of the working reinforcement 20.

[0140] Furthermore, each filamentous carcass reinforcing element 360 is located in the circumferential direction X of the tire 10, - In the axial center of the carcass layer extending axially parallel to the working layer 26, the angle is strictly less than 80° in absolute terms. - Between the axial center of the carcass layer 36 and each axial edge, in the two axial sides of the carcass layer 36 that extend in the axial and radial directions, the angle is in the range of 80° to 90° in absolute value. Each filamentous carcass reinforcing element 360 extends in the main direction D3, forming the structure.

[0141] As described above, a tire comprising a single working layer and a carcass layer, and a process for manufacturing the same, are known in particular from European Patent No. 3489035, French Patent No. 2797213 and French Patent No. 1413102.

[0142] Here, a tire according to the third embodiment will be described with reference to Figures 9 and 10. Elements similar to those in the previous embodiments are denoted by the same reference numerals.

[0143] Unlike the first embodiment, the two adjacent circumferential windings Ci of the strip 40 overlap each other radially and axially.

[0144] Figure 9 depicts the woven filament-like hooping reinforcement elements as white circles when they belong to a given circumferential winding Ci, and as circles filled with dots when they belong to a circumferential winding Ci+1 adjacent to the circumferential winding Ci.

[0145] In this embodiment, the radial outer surface 102 is, in accordance with the present invention, the surface passing through the radially outermost point of the radially outermost woven filament hooping reinforcing element 220 among the woven filament hooping reinforcing elements 220. Here, the radially outermost woven filament hooping reinforcing element 220 among the woven filament hooping reinforcing elements 220 is the woven filament hooping reinforcing element 220 of each circumferential winding that radially overlaps the woven filament hooping reinforcing element 220 of the adjacent circumferential winding.

[0146] Furthermore, in this embodiment, the radial inner surface 104 is, in accordance with the present invention, the surface passing through the radially innermost point of the radially innermost woven filament hooping reinforcing element 220 among the woven filament hooping reinforcing elements 220. Here, the radially innermost woven filament hooping reinforcing element 220 among the woven filament hooping reinforcing elements 220 is the woven filament hooping reinforcing element 220 of each circumferential winding whose adjacent woven filament hooping reinforcing elements 220 overlap radially, and whose other woven filament hooping reinforcing elements 220 do not overlap.

[0147] Here, the tire according to the fourth embodiment will be described with reference to Figures 11 and 12. Elements similar to those in the previous embodiments are denoted by the same reference numerals.

[0148] Similar to the first and second embodiments, in the fourth embodiment of the tire 10, the strip 40 is spirally wound over multiple circumferential windings Ci such that two adjacent circumferential windings Ci of the strip 40 do not overlap each other in the axial and radial directions at the axial center P0 of the crown 12. Accordingly, as can be seen in Figures 11 and 12, at the axial center P0 of the crown 12, there is no radial overlap between one of the woven filament hooping reinforcing elements of one circumferential winding Ci of the strip 40 and one of the woven filament hooping reinforcing elements of a circumferential winding Cj adjacent to the circumferential winding Ci. Unlike the first and second embodiments, at the axial center of the crown, the adjacent longitudinal axial edges of two adjacent circumferential windings are axially separated from each other without forming an axial or radial overlap between the two circumferential windings.

[0149] Official Exam

[0150] First comparative test

[0151] A comparison was made between two control tires, T0 and T1, which were identical to each other except for the hoop reinforcement and the radial distance E2, during the aggressive driving test described below.

[0152] The control tire T0 has a hoop reinforcement in which the woven filamentous weft reinforcing elements are not connected to each other by any of the filamentous weft elements. In other words, the hoop reinforcement of the control tire T0 has no filamentous weft elements. Furthermore, E2 = 0.11 mm.

[0153] The control tire T1 has a hoop reinforcement in which woven filamentous weft reinforcing elements are connected to each other by filamentous weft elements. Furthermore, E2 = 0.30 mm.

[0154] Each test tire was inflated to a pressure equal to 80% of the nominal air pressure for a passenger car intended and capable of carrying it. The vehicle drove on a circuit consisting of sections of tarmac-paved road and sections of crushed stone with raised and protruding parts that could attack the tread of the tire being tested. The vehicle drove several laps of this circuit to ensure that the tread was attacked by crushed stone, whether when passing over the crushed stone-covered sections or when entering the tarmac-paved sections if crushed stone was lodged in the tread. The circuit also included a wet section containing a mound of saltwater to allow a corrosive agent to penetrate the areas where the crushed stone attacked the tire. After sufficient driving, e.g., several thousand kilometers, the tread and hoop reinforcement were removed from each tested tire, and the radially outermost working layer of the working reinforcement was analyzed.

[0155] During this analysis, first, the number of attacks Np present in the radially outermost working layer of the working reinforcement is counted. Next, the surface area of ​​each oxidation pocket is measured. Then, the total surface area St of all oxidation pockets in the radially outermost working layer of the working reinforcement is estimated from these values.

[0156] The various characteristics of the control tires T0 and T1, as well as the results of the aggressive driving tests described above, are summarized in Table 1 below.

[0157] The attack count Np is given with the control tire T1 as the baseline value of 100. A number Np greater than 100 means that the radially outermost working layer of the tested tire has more attacks than the control tire T1.

[0158] Similarly, the total surface area St is given with the control tire T1 as the baseline value of 100. A total surface area St greater than 100 means that the radially outermost working layer of the tested tire has a total surface area of ​​oxidation pockets greater than that of the control tire T1. [Table 1]

[0159] This first comparative test demonstrates that the presence of cotton filamentous weft elements in control tire T1 results in a significant increase in the total surface area St of the oxidation pockets compared to control tire T0, which has no filamentous weft elements in the hoop reinforcement.

[0160] On the one hand, the number of attacks Np in the control tire T0 is far greater than that of the control tire T1, and on the other hand, the average radial distance E2 in the control tire T0 is significantly smaller than that of the control tire T1, so this is all the more unexpected. In fact, a large number of attacks Np is expected to result in a large number of oxidation pockets, and therefore, the total surface area St of oxidation pockets in the control tire T0 is expected to be larger than that of the control tire T1. Furthermore, a small average radial distance E2, and therefore a small material thickness, makes it easier for corrosive agents to be transmitted, and therefore, the total surface area St of oxidation pockets in the control tire T0 is expected to be larger than that of the control tire T1.

[0161] Second comparative test

[0162] A comparison was made between the control tires T2 and T3 and the tire 10 according to the first embodiment described above.

[0163] The control tire T3 is equipped with the same filamentous hooping reinforcement elements as tire 10 according to the first embodiment. In the control tire T2, each filamentous hooping reinforcement element comprises two multifilament twists, each multifilament twist consisting of a monofilament yarn of aliphatic polyamide, in this case nylon, with a count equal to 140 tex, and these two multifilament twists are individually twisted spirally in one direction at 250 turns per meter, and then twisted together spirally in the opposite direction at 250 turns per meter.

[0164] In addition, for the control tire T3 and the tire 10 according to the first embodiment, E1 = 1.50 mm. For the control tire T2, E1 = 2.30 mm.

[0165] Furthermore, while the reference tire T2 has an E2 of 0.44 mm and the reference tire T3 has an E2 of 0.38 mm, the tire 10 according to the first embodiment has an E2 of 0.23 mm.

[0166] In addition, while the filamentous weft elements of the control tires T2 and T3 are made of cotton fibers, the filamentous weft elements of the tire 10 according to the first embodiment are as described above.

[0167] The control tires T2 and T3 were compared with the tire 10 according to the first embodiment in the aggressive driving test described above. The weight and rolling resistance of the tires were also measured in accordance with United Nations Economic Commission for Europe Regulation No. 117.

[0168] The various characteristics of the control tires T2 and T3, as well as the tire 10 according to the first embodiment, and the results of aggressive driving tests, including measurements of weight and rolling resistance, are summarized in Table 2 below. [Table 2]

[0169] When comparing control tires T2 and T3, it should be noted that the mean radial distance E1 and mean radial distance E2 were significantly reduced in order to lighten control tire T3 compared to control tire T2. Thus, the thickness of the material(s) protecting the woven filamentous hooping reinforcing elements from attack has been significantly reduced, and the thickness of the material(s) protecting the metal filamentous working reinforcing elements from corrosive agents transmitted by the filamentous weft elements has also been significantly reduced. Consequently, as demonstrated during the initial aggressive driving test, a significant increase in the number of attacks Np and, therefore, an increase in the total surface area of ​​oxidation pockets in control tire T3 was observed due to the significant propagation of corrosive agents via the cotton filamentous weft elements. Furthermore, it should be noted that the filamentous hooping reinforcing elements of control tire T2 are wider than those of tire T3 and tire 10 according to the first embodiment, making them more susceptible to transmitting corrosive agents, which is all the more noteworthy.

[0170] Comparing the control tire T3 with the tire 10 according to the first embodiment, it is observed that the number of attacks Np is substantially the same for the same mean radial distance E1. However, in the case of the tire 10 according to the first embodiment, a much lower total surface area St of oxidation pockets is observed despite a smaller E2 value than that of the control tire T3. According to the present invention, this is due to the presence of filamentous weft elements that limit or even eliminate the propagation of corrosive agents in the hoop reinforcement.

[0171] Comparing the control tire T2 with the tire 10 according to the first embodiment, it can be observed that, despite the significantly smaller average radial distances E1 and E2 of the tire 10 according to the first embodiment, the total surface area St of the oxidation pockets of the tire 10 according to the first embodiment is not significantly larger than that of the control tire T2. In any case, the increase in the total surface area St of the oxidation pockets is not proportional to the degree of tire weight reduction, nor is it proportional to the increase in rolling resistance.

[0172] Therefore, in conclusion, by reducing E1 and / or E2, and thus reducing the weight of the tire, and thus reducing its rolling resistance, it is possible to suppress or even reduce the formation of oxidation pockets using the filamentous weft elements of the present invention, which prevent the propagation of corrosive agents.

[0173] The present invention is not limited to the embodiments described above.

[0174] It will be understood that further reductions in thicknesses E1 and E2 are highly possible in order to achieve the technical effects of the present invention. Therefore, it is possible to envision tires with E1 ≤ 1.40 mm, and more preferably E1 ≤ 1.20 mm, which will allow for further weight reduction of the tire. It is also possible to envision tires with E2 ≤ 0.20 mm, in which case as well, it will be possible to further weight reduction of the tire.

[0175] Furthermore, if it is determined that reinforcement of the carcass reinforcement 34 is necessary, it is also possible to consider a carcass reinforcement 34 having two carcass layers. [Explanation of symbols]

[0176] 14 tread 72, 74, 76, 78 Main circumferential cuts 80, 82, 84 Sub-circumferential cuts 90, 92, 94, 96, 98 Horizontal cuts P0 Crown axial center P1 Crown's first axial side P2 Crown's second axial side X Circumferential direction of the tire Y-shaped tire axial direction Z Tire Radial Direction

Claims

1. A tire (10) comprising a crown (12) including a tread (14) supporting a tread surface (15), wherein the crown (12) extends over an axial width (L0) equal to 50% of the axial width (L) of the tread surface (15) and has an axial center portion (P0) whose axial center is above the midline plane (M) of the tire (10), and the axial center portion (P0) of the tread (14) comprises at least one deepest notch (74, 76) of the axial center portion (P0) of the tread (14), The aforementioned crown (12) is - A working reinforcing body (20) comprising at least one radially outermost working layer (26) having a metal filament-like working reinforcing element (260), - A hoop reinforcement (22) comprising a plurality of woven filament hooping reinforcement elements (220) spirally wound around the radial direction of the working reinforcement (20) and connected to one or more filament weft elements (42), wherein the hoop reinforcement (22) is positioned radially outward of the working reinforcement (20) and radially inward of the tread (14), The crown reinforcement (16) includes, In the axial central portion (P0) of the crown (12), - A surface (100) substantially parallel to the tread surface (15) passing through the deepest cut (74, 76) in the axial center (P0) of the tread (14) or the radially innermost point of each deepest cut (74, 76), - The radial outer surface (102) passing through the radially outermost point of the radially outermost woven filament hooping reinforcing element (220) among the woven filament hooping reinforcing elements (220), The average radial distance E1 between them is E1 ≤ 2.00 mm. A tire (10) in which one or more filamentous weft elements (42) or at least one thereof comprises a plurality of woven monofilaments and / or a plurality of woven fibers selected from organic polymer synthetic fibers and monofilaments, inorganic polymer synthetic fibers and monofilaments, and aggregates of these monofilaments and fibers.

2. The tire (10) according to claim 1, wherein E1 ≤ 1.80 mm.

3. The tire (10) according to claim 1 or 2, wherein the filamentous weft element (42) or at least one thereof comprises a plurality of organic polymer synthetic woven fibers and / or monofilaments.

4. The tire (10) according to any one of claims 1 to 3, wherein the organic polymer synthetic fiber and monofilament are selected from polyester fiber and monofilament, polyamide fiber and monofilament, polyketone fiber and monofilament, polyurethane fiber and monofilament, acrylic fiber and monofilament, polyolefin fiber and monofilament, polyetherketone fiber and monofilament, and aggregates of these monofilaments and aggregates of these fibers.

5. In the axial central portion (P0) of the crown (12), - The radial inner surface (104) passing through the innermost radial point of the woven filament hooping reinforcing element (220) that is the innermost in the radial direction among the woven filament hooping reinforcing elements (220), - The radial outer surface (106) of the radial outermost working layer (26) of the working reinforcement body (20) passing through the radial outermost point of the metal filament-like working reinforcement element (260), The tire (10) according to any one of claims 1 to 4, wherein the average radial distance E2 between them is E2 ≤ 0.40 mm.

6. The tire (10) according to claim 5, wherein E2 ≤ 0.30 mm.

7. In the axial central portion (P0) of the crown (12), - The surface (100) passing through the deepest cut (74, 76) in the axial center (P0) of the tread (14) or the radially innermost point of each deepest cut (74, 76), and substantially parallel to the tread surface (15), - The radial outer surface (106) passing through the radial outermost point of the metal filament-like working reinforcing element (260) of the radial outermost working layer (26) of the working reinforcing body (20), The tire (10) according to any one of claims 1 to 6, wherein the average radial distance H between them is H ≤ 3.00 mm.

8. The tire (10) according to claim 7, wherein H ≤ 2.50 mm.

9. The tire (10) according to any one of claims 1 to 8, wherein the hoop reinforcement (22) comprises a strip (40) spirally wound over a plurality of circumferential windings (C1, C2, C3, C4), and the strip (40) comprises a plurality of woven filament hooping reinforcement elements (220) substantially parallel to each other and embedded in a polymer matrix during a calendering step.

10. The tire (10) according to claim 9, wherein the hoop reinforcement (22) is axially separated by two axial edges (221, 222) of the hoop reinforcement (22), and the strip (40) is spirally wound over a plurality of circumferential windings (C1, C2, C3, C4) so ​​as to extend axially between the axial edges (221, 222) of the hoop reinforcement (22).

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