Lightweight aircraft tires

Abstract

To provide an improved aircraft tire that can meet the requirements for high speed, high load capacity, and lightweight design. [Solution] The pneumatic tire includes a tread and a carcass positioned radially inward of the tread and including a carcass ply having a first concave portion. The belt structure is positioned radially inward of the tread and radially outward of the carcass and includes a belt ply having a second concave portion. The radial distance (d1) between the carcass ply and the belt ply, each including the first and second concave portions, is constant.

Description

[Technical Field]

[0001] This disclosure relates to a pneumatic tire having a carcass and a belt reinforcement structure, and more particularly to a carcass and belt reinforcement structure for a high-speed, high-load tire for an aircraft. [Background technology]

[0002] In high-speed pneumatic tires, significant flex occurs in the crown region of the tire when the tire enters and leaves the footprint area. This problem is particularly significant in aircraft tires, which can reach speeds exceeding 200 miles per hour during takeoff and landing.

[0003] When a tire rotates at extremely high speeds, the large angular acceleration and velocity cause the crown to grow radially outward. If the crown growth exceeds that of the opposing shoulder of the tire, a difference in diameter can occur. This difference in diameter can cause drag on the rotating tire. As a result, the shoulder area of ​​the tread wears out faster than the crown area of ​​the tread, which can shorten the lifespan of the tread and tire. This phenomenon is called uneven wear.

[0004] To suppress the growth of tread deformation and improve tread wear characteristics, conventional radial tires may include a belt structure positioned between the tread rubber layer and the carcass in the crown region. The belt structure can suppress the growth of deformation in the crown region of the tread. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent Publication 2024 / 0051344 [Patent Document 2] U.S. Patent Publication No. 2008 / 0105352A1 [Patent Document 3] U.S. Patent No. 11,186,122 [Patent Document 4] U.S. Patent No. 4,893,665 [Patent Document 5] U.S. Patent No. 4,155,394 [Patent Document 6] U.S. Patent No. 6,799,618 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] The driving force behind current tire designs is aircraft tires that can achieve high speed, high load capacity, and weight reduction. Furthermore, normally, load-bearing capacity and weight are in a trade-off relationship. Therefore, there is a need for an improved aircraft tire that can meet the requirements of high speed, high load capacity, and weight reduction. [Means for Solving the Problems]

[0007] In one example, a pneumatic tire is provided that includes a tread, a carcass including a carcass ply disposed radially inward of the tread and having a first concave portion, and a belt structure including a belt ply disposed radially inward of the tread and radially outward of the carcass and having a second concave portion, wherein a radial distance (d1) between the carcass ply and the belt ply each including the first and second concave portions is constant.

[0008] In another example, a pneumatic tire is provided that includes a tread, a carcass including a carcass ply disposed radially inward of the tread and having a first concave portion, and a belt structure including a belt ply disposed radially inward of the tread and radially outward of the carcass and having a second concave portion, wherein a radial distance (d1) between the carcass ply and the belt ply each including the first and second concave portions is constant and is in the range of 0.030 inches to 0.090 inches.

[0009] [Definitions] "Apex" refers to the elastomer filler material positioned between the ply and the folded ply in the radially upper part of the bead core.

[0010] "Ring-shaped" means that it is formed in a ring-like manner.

[0011] "Aspect ratio" refers to the ratio of the tire's cross-sectional height to its cross-sectional width.

[0012] "Bead cross-sectional aspect ratio" refers to the ratio of the bead's cross-sectional height to its cross-sectional width.

[0013] "Asymmetrical tread" refers to a tread pattern that is not symmetrical with respect to the tire's center plane or equatorial plane (EP).

[0014] "Axial" and "in the axial direction" refer to a line or direction parallel to the tire's axis of rotation.

[0015] "Bead" refers to a portion of a tire that is wrapped in ply cord and may or may not have other reinforcing elements such as flippers, chippers, apex, toe guards, and chafers, and includes an annular tension member molded to fit the design rim.

[0016] "Belt structure" means at least two annular layers or plies of parallel cords, which are located beneath the tread, are not fixed to the bead, and have cords inclined with respect to the equatorial plane (EP) of the tire, and may be woven or not. The belt structure may also include plies of parallel cords inclined at relatively small angles, which act as a restraining layer.

[0017] A "bias tire" (cross-ply) refers to a tire in which reinforcing cords within the carcass plies extend diagonally across the tire from bead to bead at an angle of approximately 25° to 65° relative to the tire's equatorial plane (EP). If multiple plies are present, the cords of the plies extend at opposite angles to each other in alternating layers.

[0018] A "breaker" refers to at least two annular layers or plies of parallel reinforcing cords that are at the same angle as the parallel reinforcing cords of the carcass ply with respect to the equatorial plane (EP) of the tire. Breakers are typically associated with bias tires.

[0019] The term "cable" refers to a cord formed by twisting together two or more pairs of pliers.

[0020] "Carcass" refers to the tire structure, including the bead, which is separate from the belt structure on the plies, the tread, the undertread, and the sidewall rubber.

[0021] "Casing" refers to the entire tire, excluding the carcass, belt structure, bead, sidewall, tread, and undertread.

[0022] "Chippa" refers to a narrow strip of fabric or steel cord located within the bead area, which serves to reinforce the bead area and stabilize the innermost radial portion of the sidewall.

[0023] "Circumferential" and "circumferential" refer to a line or direction that extends along the circumference of the annular surface of a tire parallel to the equatorial plane (EP) and perpendicular to the axial direction, and can also refer to the direction of a set of adjacent circular curves whose radius, when viewed in cross-section, defines the axial curvature of the tread.

[0024] "Concave" refers to a specific curvature in the tire structure where the tire structure curves inward toward the tire's centerline in the contact area. This inward curvature forms a concave contour when viewed across the tire's cross-section.

[0025] "Convex" refers to a specific curvature in the tire structure where the tire curves outward from the tire's centerline in the contact patch. This outward curvature forms a convex contour when viewed across the tire's cross-section.

[0026] "Code" refers to one of the reinforcing strands that make up the tire's reinforced structure.

[0027] "Cord angle" refers to the acute angle formed by the cords relative to the equatorial plane (EP) on the left or right side in a plan view of the tire. "Cord angle" is measured in a hardened but non-expanded tire.

[0028] "Crown" refers to the inner part of the tire at both ends of the tire's tread width.

[0029] "Denier" refers to the weight in grams per 9,000 meters (a unit representing linear density). "Dtex" refers to the weight in grams per 10,000 meters.

[0030] "Density" refers to the weight per unit length.

[0031] "Elastomer" refers to an elastic material that can recover its dimensions and shape after deformation.

[0032] The "equator plane (EP)" refers to a plane perpendicular to the tire's axis of rotation and passing through the center of its tread, or a plane containing the circumferential centerline of the tread.

[0033] "Fabric" essentially refers to a network of multiple cords that extend in one direction and may be twisted together, the cords being composed of multiple filaments (which may be twisted together) of a high modulus material.

[0034] A "fiber" is a unit of material, either natural or artificial, that forms the basic elements of a filament, and is characterized by having a length of at least 100 times its diameter or width.

[0035] "Filament count" refers to the number of filaments that make up a yarn. For example, 1000 denier polyester has approximately 190 filaments.

[0036] "Flipper" refers to the reinforcing fabric around the bead wire, used for strength and to secure the bead wire within the tire body.

[0037] "Footprint" refers to the contact area or region of a tire's tread that is in contact with a flat surface under normal load and pressure at zero speed.

[0038] "Gauge" generally refers to a dimension, specifically a thickness dimension.

[0039] A “groove” refers to an elongated void within the tread that extends straight, curved, or zigzag around the tread in a circumferential or lateral direction. Grooves extending circumferentially and laterally may have common portions. “Groove width” may be the portion of the tread surface occupied by a groove or groove portion divided by the length of that groove or groove portion; therefore, groove width may be the average width over the length of that groove. Grooves may vary in depth within the tire. The depth of a groove may vary around the tread, and the depth of one groove may be constant and different from the depth of another groove within the tire. When such narrow or wide grooves have substantially less depth than the wider circumferential grooves with which they interconnect, they can be considered to form a “tie bar” that tends to maintain rib-like characteristics in the tread area in question. As used herein, grooves are intended to have a width large enough to remain open within the tire’s contact area, i.e., footprint.

[0040] "High-tensile steel (HT)" refers to carbon steel with a filament diameter of 0.20 mm and a tensile strength of at least 3400 MPa.

[0041] "Inside" refers to the direction towards the inside of the tire, and "outside" refers to the direction towards the outside.

[0042] "Inner liner" means one or more layers of elastomer or other material that form the inner surface of a tubeless tire and contain the expanding fluid inside the tire.

[0043] The "inboard side" refers to the side of the tire closest to the vehicle when the tire is mounted on the wheel and the wheel is mounted on the vehicle.

[0044] "LASE" is the load at a specific elongation.

[0045] "Horizontal direction" refers to the axial direction.

[0046] "Lay length" refers to the distance that a twisted filament or strand travels until it rotates 360 degrees around another filament or strand.

[0047] "Load range" refers to the load and inflation limits of a given tire used for a specific type of driving, as defined in the Tire & Rim Association's table.

[0048] "Mega high-tensile steel (MT)" refers to carbon steel with a filament diameter of 0.20 mm and a tensile strength of at least 4500 MPa.

[0049] "Net contact area" refers to the value obtained by dividing the total area of ​​contact elements between defined boundary edges, measured around the entire circumference of the tread, by the total area of ​​the tread around the entire circumference between boundary edges.

[0050] The "net-gross ratio" refers to the value obtained by dividing the total area of ​​the tread contact elements between the lateral edges of the tread around the entire circumference by the total area of ​​the tread around the entire circumference between the lateral edges.

[0051] A "non-directional tread" refers to a tread that does not have a preferred direction of travel and does not need to be positioned on the vehicle at a specific wheel position to ensure that the tread pattern aligns with the preferred direction of travel. Conversely, a directional tread pattern has a preferred direction of travel that requires specific wheel positioning.

[0052] "Normal load" refers to the specific design inflation pressure and load specified by the appropriate standardization body for the tire's operating conditions.

[0053] "Normal tensile steel (NT)" refers to carbon steel with a filament diameter of 0.20 mm and a tensile strength of at least 2800 MPa.

[0054] The "outboard side" refers to the side of the tire that is furthest from the vehicle when the tire is mounted on the wheel and then mounted on the vehicle.

[0055] "Ply" refers to a cord reinforcement layer consisting of multiple parallel cords that are covered with rubber and arranged radially or in other ways.

[0056] "Radial" and "radially" refer to the direction toward or away from the tire's axis of rotation.

[0057] "Radial ply construction" means one or more carcass plies, or at least one ply having reinforcing cords oriented at an angle between 65° and 90° with respect to the equatorial plane (EP) of the tire.

[0058] "Radial ply tire" means a belted or circumferentially constrained pneumatic tire having a bead-to-bead cord, with at least one ply positioned at a cord angle between 65° and 90° with respect to the tire's equatorial plane (EP).

[0059] A "rib" means a circumferentially extending strip of rubber on the tread defined by at least one circumferential groove and such a second groove or lateral edge, the strip not being laterally divided by a groove of full depth.

[0060] "Rivet" refers to the open space between codes within a layer.

[0061] "Sectional height" refers to the radial distance from the nominal rim diameter to the outer diameter of the tire at the tire's equatorial plane (EP).

[0062] "Sectional width" refers to the maximum straight distance parallel to the tire axis between the outer surfaces of the sidewalls, excluding any sidewall bulges caused by labels, decorations, or protective bands, when the tire has been inflated to normal pressure for 24 hours or thereafter in an unloaded state.

[0063] "Self-supporting run-flat" refers to a type of tire that has a structure strong enough to support the vehicle load on its own when operated for a limited time at a limited speed in a non-inflated state. The tire's sidewall and inner surface will not collapse or buckle due to the tire structure alone (e.g., without an internal structure).

[0064] "Sidewall insert" refers to an elastomer or cord reinforcement located in the sidewall region of the tire. The insert may be added to the carcass reinforcement ply and the outer sidewall rubber that forms the outer surface of the tire.

[0065] "Sidewall" refers to the part of the tire between the tread and the bead.

[0066] A "sipe" or "notch" refers to a small slot molded into the tread element of a tire that further divides the tread surface to improve traction. Sipes may be configured to close when within the contact area, or footprint, to distinguish them from grooves.

[0067] The "spring constant" refers to the stiffness of a tire, expressed as the slope of the load deflection curve at a given pressure.

[0068] "Stiffness ratio" refers to the value obtained by dividing the stiffness of the belt structure being inspected by the stiffness of another belt structure, when the value is determined by a fixed three-point bending test in which the cord is bent by applying a load to the center between the fixed ends while supporting both ends of the cord.

[0069] "Ultra-high-strength steel (ST)" refers to carbon steel with a filament diameter of 0.20 mm and a tensile strength of at least 3650 MPa.

[0070] "Tenacity" is a stress expressed as force per unit linear density (gm / tex or gm / denier) in an unstrained sample. It is used in textiles.

[0071] "Tension" is a stress expressed as force / cross-sectional area. Strength (psi) = 12,800 × specific gravity × tenacity (grams / denier).

[0072] "Toe guard" refers to the circumferentially arranged elastomer rim contact portion of the tire, located on the axially inner side of each bead.

[0073] "Tread" refers to the molded rubber component that is fixed to the tire casing and includes the portion of the tire that contacts the road when the tire is properly inflated and under normal load.

[0074] "Tread element" or "traction element" refers to a rib or block element.

[0075] "Tread width" refers to the arc length of the tread surface in a plane containing the tire's axis of rotation.

[0076] The "folded end" refers to the portion of a carcass ply that is folded upward (i.e., radially outward) from the bead around which the ply is wrapped.

[0077] "Ultra-high-strength steel (UT)" refers to carbon steel with a filament diameter of 0.20 mm and a tensile strength of at least 4000 MPa.

[0078] "Vertical deflection" refers to the amount of deflection a tire experiences under load.

[0079] "Yarn" is a general term for a continuous strand of textile fibers or filaments. Yarn can be produced in the following forms: (1) a number of twisted fibers; (2) a number of untwisted filaments; (3) a number of filaments that are partially twisted together; (4) a single filament (monofilament) that may or may not be twisted; and (5) a narrow strip of material that may or may not be twisted.

[0080] The "zigzag belt reinforcement structure" consists of at least two layers of ribbons of parallel cords, each having 1 to 20 cords within it, wherein the cords of the ribbons are arranged in an alternating pattern extending between the lateral ends of the belt layers at angles between 3 and 40 degrees. [Brief explanation of the drawing]

[0081] [Figure 1] This is a cross-sectional view of an example of a tire related to this disclosure. [Figure 2] This is an enlarged cross-sectional view of a portion of the tire shown in Figure 1. [Figure 3] This is a cross-sectional view of the tire shown in Figure 1. [Figure 4] This is an enlarged cross-sectional view of a portion of the tire shown in Figure 3. [Modes for carrying out the invention]

[0082] The accompanying drawings incorporated herein and constituting part thereof illustrate an example of an aircraft radial tire and are used solely for illustrative purposes.

[0083] To facilitate understanding of this disclosure, Figures 1-4 are depicted in a simplified form and are not to exact scale. Figure 1 is a cross-sectional view of an aircraft radial tire 8 according to an example of this disclosure. The tire 8 is mounted on a rim, for example, as recommended by the Tire and Rim Association (TRA), and is inflated in an unloaded state to a pressure equal to approximately 10% of its rated inflation pressure. The tire 8 is symmetrical with respect to the equatorial plane (EP). The tire 8 also includes a pair of bead sections 10, each bead section including a bead 12 embedded within it.

[0084] The tire 8 further comprises sidewall portions 18 extending substantially radially outward from each of the bead portions 10 to the tread portion 20. The tread portion 20 extends axially between the radially outward ends of the sidewall portions 18. The tread portion 20 further comprises a radially outward tread surface 22 having a contact portion. In the example shown in Figure 1, under the above conditions, the contact portion of the tread surface 22 is convex. In other examples, the contact portion of the tread surface 22 is substantially parallel to the axial direction of the tire 8. The tread portion 20 also has one or more circumferential ribs 24 defined by one or more circumferential grooves 26. The tread portion 20 may have any number of circumferential ribs 24 and circumferential grooves 26, but as shown in Figure 1, the tire 8 has five circumferential ribs 24 defined by four circumferential grooves 26.

[0085] Furthermore, the tire 8 is reinforced by a carcass 30 that extends annularly from one bead portion 10 to the other bead portion 10 and is symmetrical with respect to the equatorial plane (EP). The carcass 30 includes a plurality of carcass plies. In the tire 8 of Figure 1, the carcass 30 includes a plurality of inner carcass plies 32 and a plurality of outer carcass plies 34, the plurality of inner carcass plies 32 being positioned radially inward relative to the plurality of outer carcass plies 34. The plurality of inner carcass plies 32 are wound around the bead portion 10 from the axially inward to the axially outward of the tire 8 to form a folded portion, and the plurality of outer carcass plies 34 extend radially downward to the bead portion 10 along the outside of the folded portion of the inner carcass plies 32. Each of the plurality of inner and outer carcass plies 32, 34 is formed from a calendered sheet of reinforcing material. Typically, such plies are made from a calendered product in which a plurality of essentially parallel reinforcing cords are covered on both sides with layers or sheets of rubber composition.

[0086] The cords of the inner and outer carcass plies 32,34 are oriented either substantially perpendicular to the equatorial plane (EP) of the tire 8, or at a certain angle to the equatorial plane (EP) of the tire 8. In one example, the cords are positioned perpendicular to the equatorial plane (EP) of the tire 8. In another example, the cords are positioned in the range of 80 to 90 degrees relative to the equatorial plane (EP) of the tire 8. In yet another example, the cords are positioned in the range of 82 to 90 degrees relative to the equatorial plane (EP) of the tire 8.

[0087] Furthermore, the cords of the inner and outer carcass pies 32,34 are of a variety of materials and structures. In one example, the cords of the inner and outer carcass pies 32,34 are nylon cords. In another example, the cords of the inner and outer carcass pies 32,34 are nylon-6,6 cords. In yet another example, the cords of the inner and outer carcass pies 32,34 are nylon-6,6 cords having a 2100 dtex / 2 / 2 structure. In an additional example, the cords of the inner and outer carcass pies 32,34 are aramid and nylon cord structures, such as hybrid cords, high-energy cords, or merged cords. Non-limiting examples of suitable cords are described in U.S. Patent Publication 2024 / 0051344, which is incorporated herein by reference. Also, the cords of the calendered ply sheet have a transverse density such that the number of ends per inch is in the range of approximately 12 to 30 when measured from the calendering machine or directly below the bead 12.

[0088] In the tire 8 of Figure 1, the carcass 30 includes three inner carcass plies 32 and two outer carcass plies 34. However, the disclosure is not limited to the number or configuration of these inner and outer plies, and may include one or more inner and outer carcass plies. The outer carcass ply 34a is the radially outermost carcass ply and includes a concave portion. The concave portion of the outer carcass ply 34a has two axial boundaries (A) that are symmetrical with respect to either side of the equatorial plane (EP). C ,A'C ) extends between. Still, the present disclosure is not limited to this configuration, and the axial boundary (A C , A’ C ) may be asymmetric about the equatorial plane (EP). The axial width (W C ) of the concave portion is the axial distance between the axial boundaries (A C , A’ C ) of the concave portion of the outer carcass ply 34a. The axial boundaries (A C , A’ C ) of the concave portion of the outer carcass ply 34a are the outermost boundaries in the radial direction of the outer carcass ply 34a. The outer carcass ply 34a further includes two convex portions on the outside of the concave portion in the axial direction. Each of these convex portions is bounded on the inside in the axial direction by the axial boundaries (A C , A’ C ) of the concave portion and on the outside by the end portions of the outer carcass ply 34a.

[0089] The other outer carcass ply 34 and inner carcass ply 32 have the same structure as the outer carcass ply 34a and, as described above, include a concave portion extending between two axial boundaries and two convex portions outside the concave portion in the axial direction.

[0090] The tire 8 is further reinforced by a belt structure 40 positioned radially between the carcass 30 and the tread portion 20. In one example, the belt structure 40 is symmetrical with respect to the equatorial plane (EP). In other examples, the belt structure 40, or at least a portion of the belt structure 40, is asymmetrical with respect to the equatorial plane (EP). The belt structure 40 includes a first belt layer 42 and a second belt layer 44. The first belt layer 42 is positioned radially outward of the second belt layer 44. The first belt layer 42 and the second belt layer 44 each include one or more belt plies, which are one of the following: low-angle or helical belt plies, zigzag belt plies, a combination of helical belt plies and zigzag belt plies, etc. Non-limiting examples of belts for use in the tire 8 of this disclosure are shown in U.S. Patent 2008 / 0105352A1 and U.S. Patent 11,186,122, which are incorporated herein by reference, respectively.

[0091] With respect to any low-angle or helical belt plies of the belt structure 40, in one example, such any belt ply has a cord positioned at an angle in the range of 0 to 20 degrees with respect to the equatorial plane (EP). In another example, any low-angle or helical belt plies of the belt structure 40 have a cord positioned at an angle in the range of 0 to 15 degrees with respect to the equatorial plane (EP). In yet another example, any low-angle or helical belt plies of the belt structure 40 have a cord positioned at an angle of 5 degrees or less with respect to the equatorial plane (EP). In yet another example, any low-angle or helical belt plies of the belt structure 40 have a cord positioned at an angle of 3 degrees or less with respect to the equatorial plane (EP).

[0092] With respect to any zigzag belt plies of the belt structure 40, in one example, such any zigzag belt plies are positioned at angles from 3 to 40 degrees with respect to the equatorial plane (EP) and have cords that alternately extend to the fold points at each lateral end of the belt structure 40. In another example, any zigzag belt plies of the belt structure 40 are positioned at angles from 5 to 40 degrees with respect to the equatorial plane (EP) and have cords that alternately extend to the fold points at each lateral end of the belt structure 40. In yet another example, any zigzag belt plies of the belt structure 40 are positioned at angles from 6 to 30 degrees with respect to the equatorial plane (EP) and have cords that alternately extend to the fold points at each lateral end of the belt structure 40.

[0093] The belt plies of the first and second belt layers 42, 44 are formed by a continuous rubberized strip wound circumferentially around the tire 8. The second belt layer 44 is first wound spirally around the carcass 30, and then the first belt layer 42 is wound spirally around the second belt layer 44. The rubberized strip may be wound continuously to form both the second belt layer 44 and the first belt layer 42. The rubberized strips of the first and second belt layers 42, 44 are reinforced with a plurality of embedded, highly elastic and non-stretchable reinforcing cords. The cords within the rubberized strip are substantially parallel to each other. The cords consist of one or more of nylon, rayon, polyester, aramid, glass, or metal, are arranged substantially parallel to each other, and are covered with an elastomer matrix such as a cured rubber casing. Appropriate codes and non-limiting examples of strips of one or more reinforcing codes are also described in U.S. Patents 4,893,665, 4,155,394, and 6,799,618, each incorporated herein by reference.

[0094] In one example, the cords of the rubberized strips forming the belt plies of the first and second belt layers 42,44 are aramid and nylon cord structures, e.g., aramid and nylon hybrid cords or mixed cords. In another example, the cords of the rubberized strips are aramid and nylon 6,6 hybrid cord structures. In yet another example, the cords of the rubberized strips are aramid and nylon 6,6 hybrid cord structures, where the aramid cord has a 3300 dtex / 1 structure, the nylon 6,6 cord has an 1880 dtex / 1 structure, and the hybrid cord has a (3300 dtex / 1 + 3300 dtex / 1 + 1880 dtex / 1)3 structure or (6.7 + 6.7 + 4.5) / 6.7 structure. The cords of the rubberized strips also have a lateral density with the number of ends per inch ranging from approximately 12 to 30. Furthermore, the strips have a gauge, i.e., thickness, ranging from 1 mm to 2 mm.

[0095] In the tire 8 of Figure 1, the first belt layer 42 contains four belt plies. However, the first belt layer 42 is not limited to this number and may contain any number of belt plies. In one example, the first belt layer 42 contains four zigzag belt plies. In another example, the first belt layer 42 consists of four spiral belt plies. In yet another example, the first belt layer 42 contains four belt plies that are a combination of spiral and zigzag belt plies.

[0096] Furthermore, the belt plies of the first belt layer 42 include one or any combination of belt structures such as concave, convex, and substantially parallel (or parallel) to the axial direction of the tire 8. In one example, at least one belt ply of the first belt layer 42 is convex and has an axial width. At least one belt ply of the first belt layer 42 is convex along its axial width. In another example, at least one belt ply of the first belt layer 42 is convex and has a portion substantially parallel to the convex axial outer end. The substantially parallel portion of the at least one belt ply is oriented symmetrically with respect to one side of the tire's equatorial plane (EP) and extends between two axial boundaries that are also oriented symmetrically with respect to one side of the tire's equatorial plane (EP). The axial width of the substantially parallel portion is the axial distance between such axial boundaries of the substantially parallel portion. At least one belt ply transitions from the substantially parallel portion to at least the end of the belt ply, between two convex portions originating from the axial boundaries. In other words, the convex portion is defined axially by the axial boundary of a substantially parallel portion on the inside in the axial direction, and by the end of at least one belt ply of the first belt layer 42 on the outside in the axial direction. In yet another example, at least one belt ply of the first belt layer 42 is substantially parallel to the axial direction of the tire 8. In yet another example, at least one belt ply of the first belt layer 42 is concave. In any of the above examples, the belt plies of the first belt layer 42 may be symmetrical or asymmetrical with respect to the equatorial plane (EP).

[0097] Furthermore, in the tire 8 of Figure 1, the second belt layer 44 includes five belt plies 44a, 44b, 44c, 44d, and 44e, where belt ply 44a is the innermost belt ply in the radial direction of the second belt layer 44, and belt ply 44e is the outermost belt ply in the radial direction of the second belt layer 44. However, the second belt layer 44 is not limited to this number and may include any number of belt plies. In one example, the second belt layer 44 includes five spiral belt plies. In yet another example, the second belt layer 44 includes five zigzag belt plies. In yet another example, the second belt layer 44 includes five belt plies that are a combination of spiral and zigzag belt plies.

[0098] Furthermore, at least one of the belt plies 44a, 44b, 44c, 44d, 44e of the second belt layer 44 includes a concave portion. In the tire 8 of Figure 1, the belt ply 44a of the second belt layer 44 is the innermost belt ply in the radial direction and includes a concave portion. The belt ply 44a has an axial endpoint (E a ,E' a ) has an axial width (W B2a ) has an axial width (W B2a ) is the axial width (W) of the tire 8. T ) is equal to at least two-thirds of the axial width (W T ) is measured on the sidewall with the tire mounted on the rim and inflated to a pressure equal to approximately 10% of its rated inflation pressure. In other examples, the axial width (W) of the belt ply 44a. B2a ) is in the range of 70% to 100% of the widest belt of the belt structure 40. In yet another example, the axial width (W) of the belt ply 44a B2a This ranges from 90% to 95% of the widest belt in the belt structure 40.

[0099] The concave portion of the belt ply 44a has two axial boundaries (A a ,A' a) extends between them, and these axial boundaries are symmetric with respect to either side of the tire equatorial plane (EP). However, the disclosure is not limited to this configuration, and the axial boundaries (A a ,A' a The axial width (W) of the concave portion may be asymmetrical with respect to either side of the equatorial plane (EP). a ) is the axial boundary (A) of the concave portion of the belt ply 44a. a ,A' a This is the axial distance between the two points. The axial boundary of the concave portion of the belt ply 44a (A a ,A' a ) is the outermost radial boundary of the belt ply 44a. The belt ply 44a further includes two convex portions outside the concave portion in the axial direction. These convex portions are the axial boundary (A) of the concave portion on the inside in the axial direction. a ,A' a ) causes the axial endpoint (E) of the belt ply 44a to be on the outside in the axial direction. a ,E' a The boundaries are defined by each of these.

[0100] Furthermore, as shown in Figures 1 and 2, the outermost carcass ply 34a and the innermost belt ply 44a in the radial direction are positioned at a constant or substantially constant radial distance (d1) from each other. That is, the outermost carcass ply 34a and the innermost belt ply 44a in the radial direction are separated by the axial endpoint (E) of the belt ply 44a. a ,E' a From one end to the other, the axial width (W B2a They are separated from each other by a radial distance (d1) along the ). Therefore, the radial distance (d1) between the radially outermost carcass ply 34a and the radially innermost belt ply 44a, each containing a concave portion, does not change or substantially changes. In one example, the radial distance (d1) is in the range of 0.030 inches to 0.090 inches. In other embodiments, the radial distance (d1) is 0.050 inches.

[0101] Furthermore, in tire 8, as shown in Figure 3, the belt ply 44b is a second belt ply on the radially inner side and includes a concave portion. The belt ply 44b has an axial endpoint (E b ,E' b ) has an axial width (W B2b ) has an axial width (W B2b ) is at least the axial width (W) of the tire 8. T ) is equal to two-thirds of the axial width (W) of the belt ply 44a. B2a It is larger than ).

[0102] The concave portion of the belt ply 44b has two axial boundaries (A b ,A' b ) extends between them, and these axial boundaries are symmetrical with respect to either side of the equatorial plane (EP) of the tire. However, the disclosure is not limited to this configuration, and the axial boundaries (A b ,A' b The axial width (W) of the concave portion may be asymmetrical with respect to either side of the equatorial plane (EP). b ) is the axial boundary (A) of the concave portion of the belt ply 44b. b ,A' b This is the axial distance between the two points. The axial boundary of the concave portion of the belt ply 44b (A b ,A' b ) is also the outermost radial boundary of the belt ply 44b. The belt ply 44b further includes two convex portions outside the concave portion in the axial direction. These convex portions are the axial boundary (A) of the concave portion on the inside in the axial direction. b ,A' b ) causes the axial endpoint (E) of the belt ply 44b to be on the outside in the axial direction. b ,E' b The boundaries are defined by each of these.

[0103] As shown in Figures 3 and 4, the belt plies 44a and 44b are positioned at a constant or substantially constant radial distance (d2) from each other. That is, the belt plies 44a and 44b are separated by the axial endpoint (E) of the belt ply 44a. a ,E' a From one end to the other, the axial width (W B2a They are separated from each other by a radial distance (d2) along the ) line. Therefore, the radial distance (d2) between belt ply 44a and belt ply 44b, each containing a concave portion, does not change or substantially changes. In one example, the radial distance (d2) is in the range of 0.030 inches to 0.090 inches. In another example, the radial distance (d2) is 0.050 inches.

[0104] Similarly, the outermost carcass ply 34a and the innermost belt ply 44a are parallel in the radial direction, and the belt ply 44a and belt ply 44b are parallel, so the outermost carcass ply 34a and belt ply 44b are also parallel in the radial direction, or are spaced a constant or substantially constant radial distance apart from each other.

[0105] Furthermore, in the tire 8 of Figure 1, the other belt plies 44c, 44d, and 44e of the second belt layer 44 are either convex or parallel or substantially parallel to the axial direction of the tire 8. Specifically, the belt plies 44c, 44d, and 44e are convex. However, the belt plies 44c, 44d, and 44e of the second belt layer 44 are not limited to the configurations described above and may include one or any combination of belt structures, including concave, convex, and substantially parallel (or parallel) portions to the axial direction of the tire 8. In any of the examples described above, each of the belt plies of the second belt layer 44 is either symmetrical or asymmetrical with respect to the equatorial plane (EP).

[0106] Wherever the terms “include” or “including” are used herein or in the claims, these terms are intended to be inclusive, similar to the term “comprise” when used as a connecting word in the claims. Furthermore, wherever the term “or” is used (e.g., A or B), it is intended to mean “A or B, or both.” If the applicant intends to indicate “only A or B, and not both,” the term “A or B only, and not both” is adopted. Thus, the use of these terms here is inclusive, not exclusive. See Bryan A. Garner, “A Dictionary of Modern Legal Usage 624” (2nd edition, 1995). Also, wherever the terms “in” or “into” are used herein or in the claims, “on” or “onto” is intended to have an additional meaning. Where the term “selectively” is used herein or in the claims, it is intended to mean a state of a component that allows the user of the device to activate or deactivate a feature or function of that component as needed or desired in the use of the device. Where the term “operatively connected” is used herein or in the claims, it is intended to mean that the identified component is connected to perform a specified function. Where the term “substantially” is used herein or in the claims, it is intended to mean that the identified component has a relationship or quality indicated by a degree of error that would be acceptable in the industry covered. In this specification and in the claims, the singular forms “a,” “an,” and “the” include the plural. Finally, where the term “about” is used with a number, it is intended to include ±10% of that number.In other words, "approximately 10" can sometimes mean between 9 and 11.

[0107] As stated above, this disclosure is illustrated by the description of its embodiments, and the embodiments are described in considerable detail, but it is not the applicant's intention to limit the appended claims to such detail or to limit them in any way. Additional advantages and variations will be readily apparent to those skilled in the art who benefit from this application. Thus, in its broader embodiments, this application is not limited to any particular detail, any described exemplary example, or any apparatus mentioned. Such details, examples, and apparatus can be deviated from without departing from the spirit or scope of the overall inventive concept.

Claims

1. Tread and A carcass comprising a carcass ply having a first concave portion, which is arranged radially inward of the tread, A belt structure including a belt ply having a second concave portion, which is positioned radially inward of the tread and radially outward of the carcass, Includes, The radial distance (d) between the carcass ply and the belt ply, each including the first and second concave portions. 1 ) is a constant, pneumatic tire.

2. The aforementioned radial distance (d 1 The pneumatic tire according to claim 1, wherein the diameter is in the range of 0.030 inches to 0.090 inches.

3. The aforementioned radial distance (d 1 The pneumatic tire according to claim 1, wherein the diameter is 0.050 inches.

4. The pneumatic tire according to claim 1, wherein the belt ply includes a helical belt ply having cords arranged in a range of 0 to 15 degrees with respect to the equatorial plane (EP) of the pneumatic tire, and the cords of the belt ply have a hybrid structure.

5. The pneumatic tire according to claim 1, wherein the carcass ply has cords arranged perpendicular to the equatorial plane (EP) of the pneumatic tire, and the cords of the carcass ply are nylon-6,6 having a 2100 dtex / 2 / 2 structure.

6. The carcass ply and the belt ply are defined by the axial width (W) of the belt ply. B2a A pneumatic tire according to claim 1, which is parallel to the )

7. The pneumatic tire according to claim 1, further comprising zigzag belt plies radially outward of the belt plies, the belt structure being arranged at an angle of 3 to 40 degrees with respect to the equatorial plane (EP) of the pneumatic tire and having cords that alternately extend to the fold points of each lateral end of the belt structure.

8. The pneumatic tire according to claim 1, wherein the belt structure includes a second belt ply located radially outward from the belt ply, the second belt ply is a helical belt ply having cords arranged in a range of 0 to 15 degrees with respect to the equatorial plane (EP) of the pneumatic tire, and the second belt ply has a third concave portion.

9. The radial distance (d) between the belt ply containing the second and third concave portions and the second belt ply. 2 The pneumatic tire according to claim 1, wherein the coefficient of force is constant.

10. The radial distance (d) between the carcass ply and the second belt ply, each including the first and third concave portions. 3 The pneumatic tire according to claim 8, wherein the coefficient of the pressure is constant.

11. Tread and A carcass comprising a carcass ply having a first concave portion, which is arranged radially inward of the tread, A belt structure including a belt ply having a second concave portion, which is positioned radially inward of the tread and radially outward of the carcass, Includes, The radial distance (d) between the carcass ply and the belt ply, each including the first and second concave portions. 1 The diameter of a pneumatic tire is constant and ranges from 0.030 inches to 0.090 inches.

12. The aforementioned radial distance (d 1 The pneumatic tire according to claim 11, wherein the diameter is 0.050 inches.

13. The pneumatic tire according to claim 11, wherein the belt ply includes a helical belt ply having cords arranged in a range of 0 to 15 degrees with respect to the equatorial plane (EP) of the pneumatic tire, and the cords of the belt ply have a hybrid structure.

14. The pneumatic tire according to claim 11, wherein the carcass ply has cords arranged perpendicular to the equatorial plane (EP) of the pneumatic tire, and the cords of the carcass ply are nylon-6,6 having a 2100 dtex / 2 / 2 structure.

15. The carcass ply and the belt ply are parallel along the axial width (W B2a ) of the belt ply. The pneumatic tire according to claim 11.

16. The pneumatic tire according to claim 11, further comprising zigzag belt plies radially outward of the belt plies, the belt structure being arranged at an angle of 3 to 40 degrees with respect to the equatorial plane (EP) of the pneumatic tire and having cords that alternately extend to the fold points of each lateral end of the belt structure.

17. The pneumatic tire according to claim 11, wherein the belt structure includes a second belt ply located radially outward from the belt ply, the second belt ply being a helical belt ply having cords arranged in a range of 0 to 15 degrees with respect to the equatorial plane (EP) of the pneumatic tire, and the second belt ply having a third concave portion.

18. The radial distance (d) between the belt ply containing the second and third concave portions and the second belt ply. 2 The pneumatic tire according to claim 17, wherein the coefficient of the pressure is constant.

19. The pneumatic tire according to claim 18, wherein the radial distance between the carcass ply, which includes the first and third concave portions respectively, and the second belt ply is constant.

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