MXPA99010616A - Tire with composite ply structure and method of manufacture - Google Patents

Abstract

A tire (10) has a composite ply (40). The composite ply (40) has a primary ply (40A) reinforced with parallel inextensible cords (41) and a pair of ply extensions (40B) having synthetic cords. The method of manufacturing the tire (10) is described. The tire (10) can be made as a runflat type tire.

Description

PNEUMATIC WITH COMPOSED LAYER STRUCTURE AND MANUFACTURING METHOD TECHNICAL FIELD This invention relates to tires in general and, more specifically, to tires having a composite layer structure that includes at least one primary layer of non-extensible radial cords, most preferably fine diameter steel cords. for use on passenger tires or light truck tires, which include, but are not limited to, "runflat" tires.

BACKGROUND OF THE INVENTION The use of steel radial ropes in tires is well known in the art, tires for excavators and commercial trucks have used tires with steel ropes for years. As the use of steel strings in passenger rims is attempted, some common problems must be solved about how to consistently bend an upward layer of a layer reinforced with steel cords. Throughout history one must first ask the question whether it is still necessary to fold up the layer.

In 1921 Charles Miller in U.S. Patent 1,394,952 showed that the layers should be securely anchored to the heels by means of strips of cloth with crossed threads relative to the layer cords without some of the layers actually wrapping around the core of the layer. heel. Miller's tires showed that only four layers were possible, a discovery for the tires of this era. In 1342, S. M. Elliott in U.S. Patent 2,430,560 reported that tires for the field could be made with greater elastic deformation if the cloth strips that wrap around the heel do not make contact with the layers of the body. A radical departure from what was an accepted practice. In 1968, Fred Kovac and Grover Rye of Goodyear patented a slanted tire leaving an outer layer with giant ropes of 0.037 inches or larger. This outer layer consisted of two parts, a biased body layer and a pair of radial bead layers. The edges of the heel layers overlap the edges of the layers of the body and are interspersed between them. Kovac et al. They indicated that the body layer can be wire and the heel layers can be reinforced with fabric or filaments. Kovac rightly observes that if the giant ropes are used in the shell, the layers that contain them are so rigid that it is difficult for the tire manufacturer to bend them around the heels. In this way, he recommended that the edges of the stiffer layers be under the heels and the layers of softer fabric heels be folded under the heels with their edges superimposed on the edges of the rigid layers. Powers et al of The Firestone Tire & Rubber Company showed a pneumatic tire with radial layers with one or more layers of the body containing radially directed non-extensible cords, with the ends of the layer ending on the same side of the heel beam as the layer. The rim also has a heel connector layer containing inextensible, radial reinforcing cords that are wrapped around the bead beam. Powers et al noted that a British Patent No. 990,524 of the prior art discloses a body of radical layers and a radially shaped bead wrap, the strings of the body layers being rayon cords and the bead wrap being reinforced with cords of steel. Powers notes that the differences in the module gave rise to the fact that the strings did not act together as if they were in a layer, while their design of all non-extensible strings acts as a layer. Powers taught that the body layer and the layer connecting the heel, where these are adjacent to each other, should be at least 20% and not more than 50% of the peripheral distance of the body layer measured from the midpoint of the beam from the heel along the body layer to the point on the body layer where the edges of the tread layer are located. Powers suggests that glass ropes can be used, steel or Kevlar. The Powers et al test rim was a 11-22.5 truck tire that used Ix4 + 6x4x.175 + lx.15 radial ropes of steel wire of a cable construction with 14 ends per inch. In the same way, the heel connector used the same construction of steel wires. These truck tires carry a high operating inflation pressure of approximately 100 psi and the Powers patent demonstrated a potentially viable concept although the commercialization of these truck tires has not been seen. In 1995, Ahmad et al described a pneumatic tire with a discontinuous outer shell layer. Ahmad et al described a radially complete inner layer with a conventional bent end and a discontinuous outer shell layer extending from below the belt edges towards the bead, the outer layer being in contact with the outer layer. EPO publication 822195A2 discloses a runflat tire and the method showing a "runflat" tire with multiple radial layers, wherein at least one layer is wrapped around the heel and has a fold, the remaining layers simply end up near the heel. The concept of the heel area appears similar to the prior art solutions described in Runflat Tire and Method with the exception of the layers being separated by load materials or inserts, a common feature of the runflad rims. The present invention provides a form Novelty to create a structure composed of layers in a pneumatic tire. The rim can be a pneumatic tire with radial layers that includes the type known as rims "runflat" BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a sectional view of the rim according to the invention. Figure 2 is a fragmentary, amplified view of a portion of the side wall of the rim of Figure 1. Figure 3 is a cross-sectional view of an alternative embodiment of the rim according to the invention, the rim being a rim " runflat ". Figure 4 is a fragmented, amplified view of the portion of the side wall of the rim of Figure 3. Figure 5 is a perspective view of the composite layer shown on a construction drum manufactured using a first method of assembly. Figure 5A is a sectional view of the carcass made for the first method.

Figure 6 is a perspective view of the composite layer shown being manufactured in an alternative, preferred method. Figure 6A is a sectional view of the carcass made for the preferred alternative method. Figures 7A, 7B and 7C are schematic views of the casing for the "runflat" rim of Figure 4 manufactured according to the method of Figure 6. Figure 8 is a sectional view of u, the second embodiment alternative of the "runflat" rim. Figure 9 is a sectional view of a third alternative embodiment of the rim "° * runflat".

SUMMARY OF THE INVENTION A rim 10 with a tread 12, a belt structure 36 and a carcass 30 radially inwardly of the tread 12 and the belt structure 36 is described. A carcass 30 has a pair of portions. of heel 22, each heel portion 22 having an elastomeric apex 48 and a non-extensible bead core 26. The housing 30 has at least one composite layer structure 40 radially inwardly of the belt structure 36 and extending from and wrapping around of each bead core 26. The at least one composite layer structure 40 has a primary layer 40A reinforced by cords 41 with a modulus E of X or greater, the cords 41 extending radially and extending substantially inextensible from the bead portion 22 to the heel portion 22. The composite layer 40 further has a pair of layer extensions 40B reinforced by flexible cords 43. The extension of the layers 40B are superposed to the primary layer 40A and wrapped around the bead cores 26 and the elastomeric apex 48 extending radially outwards. The cords 41 of the primary layer 0A of the at least one composite layer 40 have a modulus X, while the cords 43 of the extension of the layer 40B have a modulus smaller than X. The cords 43 of the extension of the layer 40B they are practically extensible. The strings 43 of the extension of the layer of the at least one composite layer 40 are preferably synthetic and are selected from a group of strings made of nylon, rayon, polyester or aramid, preferably. The cords of the primary layer are preferably made of metal, more preferably of steel. In a preferred embodiment of the composite layer, the primary layer has a plurality of thin-gauge steel cords placed uniformly. The ropes have a diameter C in millimeters and one or more filaments. Each filament has a diameter D and preferably a tensile strength of at least (-2,000D + 4,400 MPa) x 95%, where D is the diameter of the filament in millimeters and C is less than 0.75 millimeters. An elastomeric material encapsulates this rope material. The elastomeric material has a gauge thickness in the diameter range of the rope C plus 0.22 mm to C plus 1.25 mm. Preferably, the strings are evenly spaced at 14 epi or more per inch. In a second embodiment of the rim according to the invention, the housing 30 has a pair of sidewall structures 20. Each structure of the side wall extends radially inwardly from the tread. Each side wall has at least a first insert 42 radially inward of the at least one composite layer 42., a second insert 46 and a second layer 38 being separated from the at least one composite layer 40 by the second insert 46. The second layer 38 is reinforced by radial cords 45, the cords 45 having a modulus E different from the cords of the primary layer of the at least one composite layer structure 40. The cords of the second layer 38 are made of a synthetic material, preferably selected from the group of nylon, polyester, rayon or aramid. In the preferred "runflat" embodiment, inserts 42, 46 are made of an elastomeric material, which may be reinforced with ropes or otherwise reinforced with short synthetic fibers. Inserts 42, 46 have a Shore hardness. A in the range of 40 to 85, each insert 42, 46 can employ different hardness values.Three or more additional inserts can be used if desired.Although any insert material known in the art is useful, the material similar to the described in U.S. Patent No. 5,368,082 are more acceptable as they are found in copending application 08 / 865,489 filed May 29, 1997. In one embodiment, the rim has a maximum width of the section at a height (h) and the at least one composite layer 40 has a pair of bent ends 32, a bent end 32 being wrapped around each bead core 26 and extending radially at a distance of at least 40% of (h). In another embodiment, the rim has bent ends of the at least one composite layer 40 extending radially to and laterally beneath the belt structure. In still another alternative embodiment of the rim, the second layer 38 has the bent ends terminating radially below the bent ends of the at least one structure of the composite layer. Otherwise, the bent ends of the composite layer structure 40 may end radially below the bent ends of the second layer structure 38. In any case, at least one layer structure must have the terminal ends extending radially to a distance of at least 40% of the height (h). The second and first inserts are of elastomeric material with a Shore A hardness in the range of 40 to 85. The first insert may be different in shore hardness relative to the second insert. In a third and fourth embodiments, the composite layer 40 has an extension of the layer that surrounds the heel 40B with the cords encapsulated in elastomeric material having a predetermined thickness in the cross section (T) measured perpendicular between a first surface and a second surface. The strings are closer to the first surface. The second surface is adjacent to the primary layer in the region of the side walls.

Definitions "Relationship between dimensions" 'means the relation of its height of the section to its width of the section. "Axial" and "axially" means the lines or directions that are parallel to the axis of rotation of the rim, "Heel" or "bead core" generally means that part of the rim that consists of an annular traction member, the heels radially internal are associated with keeping the tire to the rim being wrapped by strings of the layers and formed, with or without other reinforcement elements such as cuts, pieces, apices or fillings, risers and screens. "Belt structure" or "Reinforcement belts" means at least two annular layers or layers of parallel strings, woven or non-woven, below the tread, not anchored to the heel, and having left and right cord angles at the heel. the range from 17 ° to 27 ° with respect to the equatorial plane of the tire. "Circumferential" means the lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction. "Shell" means the structure of the tire in addition to the structure of the belt, the tread, the lower part of the tread, on the layers, but including the beads. "Coating" means the carcass, belt structure, heels, sidewalls and all other components of the tire except the tread and the underside of the tread. "Screens" refers to narrow strips of material placed around the outside of the heel to protect the layers of the cords from the rim, distribute bending over the rim. "Rope" means one of the reinforcing threads of which the layers in the tire are composed. "Equatorial plane (PE)" means the plane perpendicular to the axis of rotation of the tire and passing through the center of its tread. "Footprint" means the area or contact area of the tread of the tire with a flat surface at zero speed and under normal load and pressure. "Inner lining" means a layer or layers of elastomer or other material that forms the inner surface of a tire without an inner chamber and that contains the inflator fluid within the tire. "Normal inflation pressure" means the specific design inflation pressure and the load assigned by the organization of adequate standards for the state in service for the tire. "Normal load" means the inflation pressure and the load of the specific design assigned by the organization of adequate standards for the state in service for the tire.

** "Layer" means a layer of parallel strings covered with rubber. "Radial" and "radially" means the directions radially toward or away from the axis of rotation of the tire. "Tire with radial layers" means a pneumatic rim with belt or circumferentially restricted in which at least one layer has cords extending from the heel to the bead and are at corners of the strings between 65 ° and 90 ° with respect to the plane equatorial tire. "Section height" means the radial distance from the nominal diameter of the rim to the external diameter of the tire in its equatorial plane. "Section Width" means the maximum linear distance parallel to the axis of the tire and between the outside of its walls when and after it has been inflated to normal pressure for 24 hours, but without load, the elevations of the walls are excluded laterals due to labeling, decoration or protective bands. "Shoulder" means the upper portion of the side wall just below the edge of the tread. "Sidewall" means that portion of a tire between the tread and the heel. "Tread width" means the arc length of the tread surface in the axial direction, ie, in a plane parallel to the axis of rotation of the tire.

DETAILED DESCRIPTION OF THE INVENTION The reference numbers as represented in the drawings are the same as those indicated in the specification. For purposes of this application, the different embodiments illustrated in the figures each use the same reference number for similar components. The structures basically used the same components with variations in place or quantity, originating by this means the alternative constructions in which the concepts of inventiveness can be practiced. The tire 10 according to the present invention employs a single side wall structure 20. The tires 10 as illustrated in Figures 1 and 2 are radial tires for passengers or light trucks; the tires 10 are provided with a tread portion with grinding calibration 12 terminating in the shoulder portions on the lateral edges 14, 16 of the tread 12, respectively. A pair of side wall portions 20 extend from the side edges 14, 16, respectively and terminate in a pair of bead portions 22, each with an annular, inextensible bead core 26, respectively. The tire 10 is further provided with a structure that reinforces the housing 30 which extends from the heel portion 22 through a portion of the side wall 20, the tread portion 12, the opposite sidewall portion 20 toward the portion heel 22. The structure of the housing 30 has at least one composite layer structure 40 with bent ends 32 wrapped around the bead cores 26, respectively. The tire 10 may include a conventional inner liner 35 forming the inner peripheral surface of the tire 10 if the tire is to be of the non-inner chamber type. Circumferentially positioned around the radially outer surface of the structure that reinforces the casing 30 below the portion of the tread 12 is a belt structure reinforcing the tread 36. In the particular embodiment illustrated, the belt structure 36 it consists of two cut belt layers 50, 51 and the cords of the belt layers 50, 51 are oriented at an angle of approximately 23 ° with respect to the semi-circumferential center plane of the tire. The cords of the belt layer 50 are positioned in an opposite direction relative to the semi-circumferential center plane and from that of the cords of the belt layer 51. However, the belt structure 36 may consist of any number of belt layers. of any desired configuration and the strings can be placed at any desired angle. The belt structure 36 provides lateral stiffness across the width of the belt to minimize the raising of the tread from the road surface during operation of the tire in the uninflated state. In the illustrated embodiments, this is done by making the strings of the belt layers 50, 51 preferably of steel and more preferably of a steel cable construction. The reinforcing structure of the carcass 30 of the tire of the preferred embodiment 10 as shown in Figure 1 consists of at least one composite layer structure 40. The at least one composite layer structure 40 has a primary layer 40A extending from the portion from the heel to the heel portion. The primary layer preferably has a layer of parallel strings 41; the cords 41 of the primary layer are oriented at an angle of at least 75 ° with respect to the semi-circumferential central plane of the tire. Superposed and attached to the primary layer 40A is a layer extension 40B having ropes 43 of the extension of the layer 40B oriented at an angle of at least 75 ° with respect to the semicircifferential central plane of the tire. In the particular modality illustrated, the strings 41 and 43 are oriented at an angle of approximately 90 ° with respect to the semi-circumferential center plane. The cords 41 of the primary layer 40A of the at least one composite layer structure 40 are preferably made of a non-extensible material such as steel, Kevlar or glass. Although the cords 43 may be made of any material normally used for the reinforcement of the cords of the rubber articles, for example, and not as a limitation, aramid, nylon, rayon and polyester. The primary layer 40B has cords 41 which are preferably substantially inextensible, the cords are synthetic or metal, more preferably metal, more preferably high tensile steel. The cords 41 have module X. In the case of the steel cords 41, the module is greater than 150 GPa. One way to achieve this resistance is by combining the appropriate process and alloys as described in U.S. Patent 4,960,473 and 5,066,455, which are hereby incorporated by reference herein in their entirety, with a micro-alloyed steel rod with one or more of the following elements: Ni, Fe, Cr, Nb, Si, Mo, Mn, Cu, Co, V and B. The preferred chemistry is mentioned below in percentages by weight: C 0.7 to 1.0 Mn 0.30 to 0.05 Yes 0.10 to 0.3 Cr 0 to 0.4 V 0 to 0.1 Cu 0 to 0.5 Ni 0 to 0.5 Co 0 to 0.1 being the difference iron and residues. The resulting rod is then stretched to the proper tensile strength. The cords 41 for use in the tire housing do not "runflat" 30 of Figures 1 and 2 may consist of one (monofilament) to multiple filaments. The number of total filaments in the rope 41 can be in the range of 1 to 13. Preferably, the number of filaments per string is in the range from 6 to 7. The individual diameter (D) of each filament is generally in the range from .10 to .30 mm, with each filament having at least one tensile strength from 2000 MPa to 5000 MPa, preferably at least 3000 MPa. Another important property of steel cords 41 is that the total elongation for each filament in the cord should be at least 2% over a length of 25 centimeters. The total elongation is measured according to ASTM A370-92. Preferably, the total elongation of the rope is in the range from about 2% to 4%. A particularly preferred total elongation is in the range of about 2.2 to about 3.0%. The torsion values for the steel for the filament used in the rope must be at least 20 turns with a calibrated length of 200 times the diameter of the wire. In general, the torque value is in the range from about 20 to about 100 turns. Preferably, the torsion values are in the range from about 30 to about 80 turns with a range from about 35 to 65 being particularly preferred. The torsion values are determined in accordance with test method ASTM E 558-83 with lengths of Test 200 times the diameter of the wire. There are different constructions of the specific metal strings 41 for use in the primary layer 40B. Representative examples of the constructions of the specific strings include: lx, 2x, 3x, 4x, 5x, 6x, 7x, 8x, llx, 12x, 1 + 2, 1 + 4, 1 + 5, 1 + 6, 1 + 7, 1 + 8, 2 + 1, 3 + 1, 5 + 1, 6 + 1, 11 + 1, 12 + 1, 2 + 7, 2 + 7 + 1, 3 + 9, l + 5 + lyl + 6 + l or 3 + 9 + l, the outer wrapping filament can have a tensile strength of 2500 MPa or greater based on a filament diameter of .15 mm. The most preferred rope constructions include the diameters of the filaments are 3x .18, 1 + 5x .18, 1 + 6x .18, 2 + 7x .18, 2 + 7x, 18x 1 x .15, 3 + 9x .18 + Ix .15, 3 + 9x.l8, 3x.20 + 9x .18 and 3 x .20 + 9x .18 + lx .15. The aforementioned string denominations are understandable to those skilled in the art. For example, the denomination 2x, 3x, 4x and 5x means a bundle of filaments; that is, two filaments, three filaments, etc. The denomination as 1 + 2 and 1 + 4 indicate, for example, a single filament wrapped by two or four filaments. The primary layer 40B has a layer of steel strings described above arranged to have from about 5 to about 100 extremities per inch ("2 to 39 ends per cm) when measured in the equatorial plane of the tire. Preferably, the string layer is arranged to have about 7 to about 60 ends per inch ("2.7 to 24 ends per cm) in the equatorial plane. The above calculations for the ends per inch are based on the range of diameters for the rope, the strength of the rope and the practical resistance requirement for the layer. For example, the high number of ends per inch will include the use of a lower diameter rope for a given strength compared to a lower number of ends per inch for a larger diameter wire for the same strength. In the alternative, if one chooses to use a rope of a given diameter, it is possible that more or fewer ends per inch have to be used - depending on the strength of the rope. The metal cords 41 of the layer 40 are oriented so that the tire 10 according to the present invention is what is commonly known as radial. The steel cord of the layer intersects the equatorial plane (PE) of the tire at an angle in the range from 75 ° to 105 °. Preferably, the steel cords intersect at an angle from 82 ° to 98 °. The preferred range is from 89 ° to 91 °. The layer 40 has a plurality of fine diameter cords 41 with the diameter of the cord C less than 1.2 mm. The rope 41 can be any of the aforementioned cords including, but not limited to, 1 + 5x.l8 mm or 3x.l8 miti or a monofilament wire having a diameter of about 0.25 mm, preferably 0.175 mm. It is considered desirable that these cords 41 have filaments with a minimum tensile strength of at least 2500 MPa and over 2.0% elongation, preferably about 4000 MPa and over 2.5% elongation. As further illustrated in Figure 2, the at least one composite layer structure 40 has a pair of layer extensions 40B, each with a pair of bent ends 32 respectively, which wrap around the core of the heel 26. ends 34 of the extension of the layer are in proximity to the bead core 26 and terminate radially above and axially inwardly of the bead core making contact superimposed with the terminal end 33 of the primary layer 40A. In the preferred embodiment, the bent ends 32 are located within 20% of the height of the SH section of the tire from the radial location (h) of the maximum width of the section, most preferably ending at the radial location (h). ) of the maximum width of the section. As shown, the bent ends 32 end radially at a distance E over the nominal diameter of the tire rim in proximity to the radial location (h) of the maximum width of the tire section. As further illustrated in Figures 1 and 2, the bead portions 22 of the tire 10 each have first and second annular, substantially non-extensible bead cores 26, respectively. The bead cores each have a flat base surface 27 defined by an imaginary surface tangent to the radially innermost surface of the bead wires. The flat base surface 27 is a pair of edges 28, 29 and a width of the heel "BW" between the edges. Preferably, the core of the heel 26 can further include a flat, radially outer surface 31 extending between the first and second surfaces 23, 25, respectively. The radially outer surface 31 has a maximum height BH, the height BH is less than the width of the base BW. The cross section defined by the surfaces 23, 25, 27 and 31 is preferably in the form of a substantially rectangular or trapezoidal cross section. The heel cores preferably constructed of a single steel wire or monofilament wrapped in continuous form. In a preferred embodiment, wires of 0.050 inch diameters are wrapped in radially internal to radially outer layers of 7, 8, 7, 6 wires, respectively. The flat surfaces of the base of the first and second bead cores 26 are preferably inclined relative to the axis of rotation, and the lower part of the multi-portion of the bead is inclined in the same manner, with the preferred inclination being approximately 10 °. in relation to the axis of rotation, preferably approximately 10.5 °. This inclination of the base of the heel helps to seal the tire and is approximately double the inclination of the flange of the bead of a conventional rim and is considered to facilitate the assembly and helps to retain the heels seated to the rim. Located within the region of the heel 22 and the radially internal portion of the sidewall portions 20 are the high modulus elastomeric apex fillings 48 positioned between the housing reinforcing structure 30 and the bent ends 32, respectively. The elastomeric filling materials 48 extend from the radially outer portion of the bead cores 26, respectively, to the portion of the side wall gradually decreasing in width in the cross section. The elastomeric filling materials 48 terminate at a radially outer end at a distance G from the nominal diameter of the rim NRD of at least 25% of the height of the section SH of the tire. In a preferred embodiment of the invention, the extensions of the layer 40B have parallel strings extending radially 43. Otherwise, the extensions of the layer 40B may have strings 43 oriented at an angle of inclination relative to the radial direction. The amount of and the direction of orientation could be in the range at an included angle relative to the radial direction in the range from 25 ° to 75 °. Preferably 45 ° or less. It is considered that the rope reinforcement of the extension of the layer 40B using inclined angle cords can be used to improve the handling characteristics of the tire when the tire is not inflated. With reference to Figures 3 and 4, the reinforcement structure of the casing 30 of the "runflat" rim of the preferred embodiment 10 as shown in Figure 3 consists of at least two reinforcing layer structures 38 and 40. In the Particular embodiment illustrated is providing a reinforcement structure of the radially inner layer 38 and a reinforcing structure of the radially outer composite layer 40, each layer structure 38 and 40 preferably having a layer of parallel strings extending radially from the portion from the heel 22 to the heel portion 22. The second reinforcing structure of the layer 38 is wrapped around the structure of the composite layer 40 and has a folded end 37 extending radially outwardly. The second structure of layer 38 preferably has synthetic nylon or rayon, aramid or polyester material. Thus, the composite layer 40 is precisely as defined at the outset with a primary layer 40A extending from heel to heel and with non-stretchable cords 41 and an overlay extension 40B with a synthetic cord 43 wrapping around the bead 26 and with a bent end 32. Radially inward of the second reinforcing structure of the layer 38 is an elastomeric insert 42 interposed between an inner liner 35 and the layer 38. Between the layer 38 and the primary layer 40A of the composite layer 40 is an elastomeric insert. 46. The cords 41 of the primary layer 40 are preferably non-extensible and made of steel, while the cords 43 of the extension of the layer are preferably synthetic and are made of a material similar to that of the second layer 38. The "runflat" tire has an unloaded and inflated section height of SH. When it is normally inflated, but with a static load, the tire deforms producing a load height of approximately 75% or less of SH. When the tire is not inflated and statically loaded, the height of the tire section is 35% or greater than SH. This class of tires generally have thicker side walls as shown in Figures 4, 8 and 9. These tires may employ a composite layer having non-extensible cords 41 with filaments of a diameter from 0.05 to 0.5 mm, preferably 0.25 to 0.4 mm These cords 41 are preferably metallic, made of steel, but are not limited to very high tensile steel strings of tires without "runflat" capability. This is made possible because the thick side walls limit the fatigue by bending or fatigue by bending the cords 41 allowing to use more rigid cords. This has the advantage of increasing the carrying capacity of the tires while reducing their cost. This construction has multiple similarities to the co-pending application titled "Runflat tire with improved housing", series No. 08 / 865,489 filed on May 29, 1997, which is incorporated in its entirety as reference herein. In this application, it was noted that the flexural modulus of the sidewall structure could be moved to be substantially adjacent to the non-stretchable cords 41 of the structure of the layer 40. By joining a superimposed synthetic cord 43 as an extension layer 40B, which is wrapped around the heel portion, the tire manufacturer can now adjust the operation of the tire so that, in the area of the heel 22 the substantially more deformable synthetic material is effectively wrapped around the beads providing easier assembly and a capability to adjust the operation of the vehicle by raising or reducing the transition between extensible and non-extensible layer cords. By doing this, the engineer can adjust the radial location of the overlap between extendable and non-extendable cords so that the tire can act more like a compound that has mainly synthetic cords in the lower bead region and can adjust the stiffness by reducing the cords non-extensible to adjust the heel area to increase the stiffness of the heel portion. With reference to Figure 5, a perspective view of a composite layer 40 shown on a construction cylinder 5 is shown. The composite layer 40 has the extensions of the layer 40B previously attached to the component of the primary layer 0A. The heel cores 26 are then placed over the extensions of the layer in an approximate area and axially adjacent to the primary layer on each side of the tire as shown. As the tire shell is inflated, the extensions of the layer 40B maintain the primary layer 40A close to the proximal location relative to the core of the heel 26. Figure 5A shows the sectional view of the features described above. Figure 6 is a perspective view of the composite layer 40 made in an alternative method. As shown, the extension of the layer 40B is placed on each side of the building drum 5 with the bead core 26 positioned directly on top of and approximately centered on each extension of the layer 40B, preferably the extension of the layer 0B and the core of the heel 26 are placed in a shallow depression on each side of the building drum 5. The primary layer 40 then extends flat or substantially flat overlying the bead cores 26 as shown in the view of 6A cut. The width W of the primary layer 40 is cut so that the width of the primary layer is within the range of the distance L between the axially internal sides 23 and its axially outer sides 25 of the bead cores 26. Preferably, the width W of the primary layer 40A is established to approximate the space between the midpoint of the two bead cores 26, thus W equals L + BW ideally. As the tire is inflated during the construction process and the extensions of the layer 40 are folded upwards to join a primary layer 40A, the primary layer 40A is stretched radially inwardly in the lower area, so that the end 33 of the primary layer 40A slides through the upper portion 31 of the bead core 26 and is preferably positioned adjacent the bead core 26 and the extension of the layer 40B at the location directly adjacent to the radially outer portion 31 of the bead core 26. It is considered that this method of manufacture ensures that the cords of the primary layer 41 are of a maximum length of the cord in relation to the location of bead to heel measured around the peripheral distance of the tire. A particularly useful feature of the assembly method shown in Figure 6 is that when the building drum is recessed, it is possible to slide the bead cores onto the drum 5 and over the extension of layer 40B without having to clean the material. apex loading 48 or the inserts because the primary layer is on the bead cores 26. The inserts 46 can be installed on the housing structure after the beads are formed, then the apex loading material 48 and the inserts 46 can be fired to the assembly after which the primary layer can be superimposed and cylindrically spliced to the unit. Heel cores 26, as can easily be seen from Figures 5 and 5A can be slid over the extensions of the layer 40B and the liner 35 from one end of the construction drum if desired or both ends in any case without having to pass over the layer primary 40. A similar advantage is obtained with the "runflat" housing unit of Figures 7A, 7B, 7C. As can be seen in Figures 5 and 6, the resulting constructions are fundamentally the same with the advantage of the method employed in Figure 6 providing the ability to reduce the end 33 of the component of the primary layer 40A to a location near the bead during the blow formation of the finished tire. The use of a non-stretchable rope 41 in the primary layer 40A ensures that the layer when being inflated onto the construction drum will act as a preloaded spring forcing the end 33 to fit securely and consistently in the proper position on the side or in proximity to the core of the heel. In an alternative construction, the width of the layer W can be set to L + greater than 2BW. This construction can ensure that the ends of the primary layer 33 are located along the axially outer surface 23 of the bead core 26.

Those skilled in the art will understand that the method for forming the tire as shown in Figures 5 or 6 can be used in Figures 1 and 2 of the tire of the invention or alternatively Figures 3 and 4 of the tire "runflat" without significant modification. With reference to Figures 8 and 9, views of cuts of a second and third alternative embodiments of the tires 10 are shown. In the tire 10 of the second embodiment, the extension of the layer of the composite layer 40B is manufactured in one way only. . As shown, both the radially inner layer 34 and the radially outer layer 32 of the extension of the layer 40B extend a distance approximately below the belt reinforcing structure 36. The extension of the layer 40B as shown has a transverse thickness T predetermined, the strings of the layer 43 are placed adjacent to a surface opposite the opposite surface giving rise to an asymmetric location of the strings 43 so that a large amount of elastomeric material is on one side of the strings 43 with almost nothing on the opposite side of the strings 43.

During the manufacture of this tire, the extensions of the layers 40B are placed in the construction drum and extend substantially wider on each side of the bead core 26. The width is sufficient so that when the tire is inflated, the ends 32, 34 will end under belts 50, 51. Primary layer 40A is between bead cores 26 as shown. When the tire 10 is inflated and the extension of the layer 40B is bent upward, the tire cutoff results as shown in Figure 7. Preferably, the elastomeric coating of the layer 40B for the extension of the layer is similar in texture. composition to the inserts inserts 42, 46 previously described. As the extension of the layer is bent upward, it forms two filled inserts and the filling of the apex from the thickest area of the coating layer. The primary layer is interposed and interposed between both ends 32, 34 of the extension of the radially extending layer, the resulting tire is a "runflat" tire where the apex filling and the inserts were ingeniously placed being incorporated into the extension of layer 40B. As can be easily appreciated by those skilled in the art, this tire greatly reduces the number of components used in the manufacture and assembly of a "runflat" tire greatly improving the speed and precision at which a tire can be manufactured. The cords 41 of the primary layer are preferably non-extensible but could be any described cord material, including nylon, rayon, polyester, and so on. If a greater efficiency in the tire's elasticity rate is necessary, the tire of Figure 8 can further include inserts 42 located radially inwardly and adjacent to the extension of the layer 40B, as shown in Figure 9. This tire "runflat" of the third alternative embodiment has a great capacity of support at an inflation pressure O. As shown, the primary layer 40A can be located somewhat centered on the core of the heel 26 by applying additional apex filling 48 in two parts on each side of the primary layer 40A. Otherwise, if a single filler 48 is employed, the primary layer 40A may be contiguous with the extension of the layer 40B as shown in Figure 4, or the primary layer 40A may be contiguous with the upturned portion 32 of the extension of layer 40B, if apex filling 48 is placed below the primary plate during assembly. When the "runflat" tire of Figure 4 is assembled with a composite layer 40, the preferred method includes the steps of providing a construction drum 5 having a contoured profile as shown in the sectional view in Figures 7A, 7B and 7C applying the coating 35, a riser of the fabric material (optional), the first inserts 42 and the layer 38 with synthetic cords superimposed on the previously mentioned components. Then, the extensions of the layer 40B are placed on the layer 38 approximately centered to the planes BB, the planes BB being the planes defining the space L between the bead cores 26. Then a bead core 26 is placed on each plane BB. It is important to note that the bead cores 26 can slide over the housing structure unimpeded due to the contours of the drum and the internal diameter of the bead cores. This means that the cores 26 can slide freely over the entire structure from the end of the building drum or the heels 26 can be installed from both ends, if desired. When the beads 26 are installed, the crown drum expands defining the location of the beads. The inserts 46 are then applied. The primary layer 40A is then placed over the inserts and the underlying components are sewn. It is important to note that the primary layer 40A has a width W equal to greater than the space L of the bead core, preferably L + the width BW of the bead core, more preferably, the distance L plus twice the width of the W of the bead core. Heel core, then the apex fillings 48 are joined preferably directly over the ends of the primary layer 40A. The casing then has the folds upward of the layer 38 and the extension 40B bent upwards and sewn into the casing. Then the rubber strips of the belt wedges and the screen components and side walls 60, 20 are joined. The casing is then inflated to a toroidal shape and as the tire 10 is being formed, the primary layer 40A slides through from the heel cores 26 to the axially internal location of the bead cores 26 joining adjacent to the extensions of the layer 40B as already described. Then, the belt layers 50, 51 and the Cover 59 (if used) are applied as well as the tread 12, thus completing the assembly of the green tire 10. In the tire 10 of the preferred embodiment of Figures 3 and 4, the cover 59 is spirally wound on the belts in three layers to improve the stiffness of the tire when the tire operates in the "runflat" state. Those skilled in the art will appreciate that the rubbing of the tires, as shown in the lower region of the bead radially outwardly of the carcass structure 30 adjacent to the rim flange can be minimized, especially during use in the tire. state not inflated by providing a portion of strong rubbing rubber 60. In addition, those skilled in the art will appreciate that the high-speed operation of the tires shown can be improved by the addition of layers of cloth 59, including, but not limited to tire covers. nylon or aramid in layers of fabric or in strips. This is known in the art.

Claims (32)

1. A tire having a tread, a belt structure and a carcass radially inwardly of the bearing surface and the belt structure, the carcass having a pair of bead portions each bead portion having an elastomeric apex and a non-extensible bead core, the carcass is characterized by: at least one layer structure composed radially inwardly of the belt structure and extending from and wrapping around each bead core, the at least one composite layer structure having a primary layer reinforced with parallel strings with an E-modulus of X or greater, with the strings extending radially and substantially inextensible, extending from the heel portion to the heel portion, and a pair of layer extensions reinforced by flexible cords, the extensions of the layer being joined in superimposed form to the primary layer and wrapping alr around the core of the heel and the elastomeric apex, and extending radially outward.

2. The tire of claim 1 further is characterized by: a pair of sidewall structures, each radially extending the tread inwardly therefrom, each of the side walls having at least a first insert radially inwardly of the tire. the at least one composite layer, a second insert, and a second layer being interposed between the first insert and the second insert, and separated from the at least one layer composed of the second insert, the second layer being reinforced by radial cords, having the radial strings a modulus E different from the strings of the primary layer of the at least one composite layer structure.

The tire of claim 1, wherein the strings of the primary layer of the at least one composite layer have a modulus X, while the strings of the extension of the layer have a modulus less than X; the ropes of the extension of the layer being practically extensible.

4. The tire of claim 4, wherein the strands of the extension of the layer of the at least one composite layer are synthetic.

5. The tire of claim 4, wherein the strands of the extension of the layer of the at least one composite layer are selected from a group of ropes made of nylon, rayon, polyester or aramid.

The tire of claim 3, wherein the strings of the primary layer are metallic.

The tire of claim 6, wherein the strings of the primary layer are made of steel.

The tire of claim 2, wherein the strings of the primary layer of the at least one composite layer have a modulus X, while the strings of the second layer have a modulus less than X.

9. The tire of the claim 8, wherein the strings of the primary layer of the at least one first layer are metallic.

The tire of claim 9, wherein the cords of the at least one composite layer of the primary layer are made of steel.

The tire of claim 8, wherein the cords of the second layer are synthetic.

The tire of claim 7, wherein the cords of the second layer are made of a material selected from the group of nylon, polyester, rayon or aramid.

13. The tire of claim 2, wherein the second layer is an insert reinforced with cords extending from below the belt structure in proximity to the bead core.

The tire of claim 1, wherein the second layer extends from each bead core and is interposed radially down the belt structure and radially inwardly of the at least one full layer [sic] having a bent end upwards wrapping around the composite layer and the heel core.

15. The tire of claim 2, wherein the second insert is elastomeric and is reinforced with ropes.

16. The tire of claim 1, where the second insert is reinforced with short fibers of synthetic material.

The tire of claim 1, wherein the tire has a section height (h) and the at least one composite layer has a pair of ends bent upwards, one end being wrapped around each bead core and extending radially at a distance of at least 40% from (h).

18. The tire of claim 1, wherein the tire has the ends of the at least one composite layer bent upwardly extending radially to and laterally down the belt structure.

The tire of claim 18, wherein the second layer has the ends bent upwardly terminating radially below the bent ends upwardly of the at least one composite layer.

The tire of claim 18, wherein the second insert and the first insert are elastomeric with a Shore A hardness in the range of 40 to 85.

The tire of claim 20, wherein the Shore A hardness of the first Insert is different from the Shore A hardness of the second insert.

22. The tire of claim 2 further comprises a third layer structure.

23. The tire of claim 21 further comprises three elastomeric inserts.

24. The tire of claim 1, wherein the primary layer of the composite layer has: a plurality of fine diameter steel ropes, uniformly positioned, the ropes having a diameter C in millimeters and one or more filaments, each filament having a diameter D and a tensile strength of at least (- 2000D + 4000MPa) x 95%, where D is the diameter of the filament in millimeters, C being less than 0.75 mm; an elastomeric material encapsulating the material of the cords, the elastomeric material having a thickness in the range of the diameter of the cord C plus 0.22 mm to C plus 1.25 mm.

25. The tire of claim 24, wherein the cords of the primary layer of the composite layer are uniformly placed 14 EPI or more ends per inch.

26. The tire of claim 1, wherein the extension of the layer has a radially inner end, the extension of the layer extending from below the belt structure wrapping around and radially outward to a radially outer end radially inwardly and adjacently. to the structure of the belt, the extension of the layer has a thickness T measured between a first surface and a second surface, the extension cords being in closer proximity to the first surface relative to the second surface.

27. The method of construction of a tire without inner chamber having a composite layer structure, consists of the steps of: cylindrically applying a coating on a construction drum; joining a pair of layer extensions, with one layer extension attached to each respective end of the coating; defining a bead core on each layer extension and fixing the axial spacing between the bead cores at a distance L; applying a primary layer having a width W, the width W being greater than L; fold up the ends of the layer extension, and give the toroidal shape to the tire.

28. The method of constructing a tire without an interior chamber having a composite layer structure of claim 27, further comprising the steps of: attaching a pair of inserts to the liner; apply a coat on the coating; and join two or more inserts to the layer.

29. The method of constructing a tire without inner chamber having a composite layer structure further comprises the steps of: with the toroidal formation of the tire, the end of the primary layer moves through the heel cores to a location axially internal joining it to the extensions of the layer.

30. A "runflat" tire, the tire having an unloaded and inflated section height of SH, a normally loaded, inflated and static section height of 75% or less of SH, and an uninflated section height , normally charged, static 35% SH or greater, the tire is characterized by: at least one layer structure composed radially inwardly of the belt structure and extending from and wrapping around each bead core, at least a composite layer structure having a primary layer reinforced with parallel ropes having an E-modulus of X or greater, the ropes extending radially and substantially inextensible, extending from the heel portion to the heel portion, and a pair of extensions of layer reinforced by flexible cords, the extensions of the layer being superposed to the primary layer and wrapping around the core of the heel n and the elastomeric apex, and extending radially outward.

31. The "runflat" tire of claim 30, the inextensible cord of the composite layer having filaments of a diameter from 0.05 50 0.6 mm [sic].

32. The "runflat" tire of claim 31, wherein the diameter of the filament is in the range of 0.25 mm to .4 mm.