MXPA99000027A - A metal string for the elastome reinforcement - Google Patents

Abstract

The present invention relates to a metal rope for the reinforcement of elastomers, the metal rope has a construction of 4 + 3 consisting of: (a) a core of four filaments, where the length of laying of the four filaments in the core is infinite, (b) a three-filament shell, where the diameter of each filament in the cord varies from 0.35 mm to 0.50

Description

A METALLIC STRING FOR THE REINFORCEMENT OF ELASTOMERS BACKGROUND OF THE INVENTION Although the invention is subject to a wide range of applications, it is particularly related to metallic rope, such as that used to reinforce elastomers. More particularly, the present invention is directed to a metal rope construction used to reinforce rubber articles, including pneumatic tires. In a conventional pneumatic radial tire using metallic cords, the fatigue properties of the framework layer and the web layer are degraded, mainly due to material fatigue due to repeated stress and erosion wear in the contact portion between the adjacent filaments . Both of these problems are said to be lightened by rubber penetration into the rope. The rubber layer interposed between the steel filaments is believed to prevent rubbing between adjacent filaments, the so-called "erosion wear". The present invention relates to a rope having improved rubber penetration into the rope. Improved rubber penetration will also provide the rope with superior corrosion resistance in case the rope is exposed to moisture. The present invention also relates to a rim having improved resistance to band edge separation resulting from the use of the 4 + 3 rope in the tire layers of the rim.

SUMMARY OF THE INVENTION The present invention relates to metal rope for reinforcement d? elastomers that has a construction of 4 + 3 where the diameter of each filament varies from 0.35 to 0.50 mm.

Brief Description of the Drawings Figure 1 is a cross-sectional view of a steel cord having a construction of the present invention, and Figure 2 is a cross-sectional view in accordance with one embodiment of the invention, taken in a plane containing the axis of rotation of the rim.

Definitions As used herein and in the claims, the terms "axial" and "axially" refer to directions that are parallel to the axis of rotation of a rim, "radial" and "radially" refer to directions that are perpendicular to the axis of rotation of a rim, "bead" refers to that part of a rim comprising an annular tension member wrapped by layer cords and configured, with or without other reinforcement elements, to fit a wheel rim of designed rim, "frame" refers to the rim structure apart from the band structure, d roda bearing band, lower tread and side wall rubber but including the heels, (the frame layers are wrapped around the heels ), "equatorial plane (EP)" refers to a plane that is perpendicular to the axis of rotation of a rim and passes through the center of the tread of the rim, "band" or "band layer" s e refers to an annular layer of parallel strings, woven or non-woven, that lies below the tread, not anchored to the bead, and that has rope angles of 15s to 66a with respect to the EP of the rim, "crown" refers substantially to the outer circumference of a rim on which the tread is disposed, "rivet" refers to the perpendicular distance between two adjacent ropes, "tenacity" refers to the breaking stress expressed as force per unit linear density of an undrawn sample (cN / Tex or gm / denier), usually used in textiles, "modulus" refers to the ratio of the change in stress to the change in fatigue, and "organic" refers to polymeric compounds that contain a structure or carbon column, which can be configured, stretched or formed into a particular physical configuration.

Detailed Description of the Preferred Modality A metallic rope is described for the reinforcement of elastomers, the metallic rope having seven filaments consisting of (a) a core composed of four filaments; And (b) a three-filament cover, where the diameter of each filament in the cord varies from 0.35 mm to 0.50 mm. In addition, a pneumatic rim with a tread is described, a frame having radial cords, two side walls spaced at a distance, which in the axial direction determines the width of the rim section, two beads around each of the rims. which are turned upwards, from the inside to the outside, the ends of the strings of the frame and a band structure which is interposed circumferentially between the tread and the frame, the band structure having a width which is substantially equal to that of the tread band and having at least two radially overlapping layers of elastomeric material reinforced with metal ropes, the metal ropes being parallel to each other and included at an angle of between 15s and 66f with respect to the equatorial plane of the rim comprising: the band structure having at least one layer that is reinforced with a metal cord that iste of (a) a core composed of four filaments; And (b) a three-filament cover where the diameter of each filament in the cord varies from 0.35 mm to 50 mm. The present invention will be explained in more detail with reference to the accompanying drawings. In Figure 1, a metal cord 10 for reinforcing elastomers is illustrated, comprising: (a) a core composed of four filaments 12, 14, 16, 18, and (b) a three-filament cover 20, 22, 24. The term "length of lay" as used herein with respect to filaments 12, 14, 16, 18 in the Core is the distance along the length of the string in which one of the filaments in the core makes one complete revolution (360s) around the outside of the four-filament core 12, 13, 16, 18. The length of the string Core filaments can vary from 5 mm to infinity (without twisting). Preferably, the length of the filaments in the core scale is infinite and, therefore, the group of four core filaments 12, 14, 16, 18 is not twisted with respect to the cord axis 10 and with respect one from another. The term "run length" as used herein with respect to the group of three filaments 20, 22, 24 in the cover is the distance along the outside of the rope 10 in which one of the filaments in the cover makes a full revolution (3602) around the outside of the rope 10. The group of three filaments 20, 22, 24 is twisted with respect to the rope axis 10, but they are parallel to each other. The length of laying of the three filaments 20, 22, 24 in the cover can vary from 5 mm to 50 mm. Preferably, the length of the run varies from about 15 mm to 25 mm. The diameter of each filament in the cord 10 can vary from about 0.35 mm to 0.50 mm. Preferably, the diameter of the filament varies from 0.38 mm to 0.44 mm. The tensile strength of each filament in terms of megapascals should be at least 3040 - (1200 x D) Mpa, where D is the diameter of the filament in mm. Preferably, the tensile strength of each filament varies from about 3040 - (1200 x D) MPa to 4400 - (2000 x D) MPa. The intended use of the rope of the present invention is a rubber reinforced article. Said articles will incorporate the rope of the present invention and which will be impregnated with rubber as is known to those experienced in the field. The representatives of the articles that can use the rope of the present invention include bands, rims and hoses. In the most preferred application, the rope of the present invention is used as a band layer of a pneumatic tire. With reference to Figure 2, one embodiment of a pneumatic tire 50 of the present invention is illustrated, which comprises a bearing band 52, frame layers 54 having radial cords., two side walls 56 spaced apart at a distance that in the axial direction determines the width of the rim section, two heels 58 around each are turned upwards, from the inside to the outside, the ends of the strings of the frame layers 54 and a band structure 60 that is circumferentially interposed and relatively inextensible between the tread band 52 and the frame layers 54. The web structure 60 has a width that is substantially equal to that of the rolling band 52 and has at least two radially overlapping layers of elastomeric material 62, 64, 66 reinforced with metal cords of the present invention. The band structure has from 2 to 12 layers, with three to four layers being preferred. According to one embodiment, the rope 4 + 3 is used in two layers 64, 66 of band or three layers 62, 64, 66 of band and the upper band 68 is reinforced with filaments or cords of an organic polymer. Any organic polymer that has sufficient strength and durability for the purpose described can be used. Examples of such organic polymers are thermoplastics such as nylon 46, nylon 66, nylon 6, nylon 12, polyesters such as polyethylene terephthalate, polyethylene naphthalate; and polyvinyl alcohol. Preferably, nylon monofilaments are used. According to one embodiment, monofilaments having a round cross section are used and have at least 2,200 decitex, with a tenacity of at least 31 cN / tex, an initial modulus of at least 177 cN / tex, an elongation at break of at least 15 percent and a shrink of at most 6 percent. Preferably, the monofilament for use in the upper band 68 has a decitex of 2,200 decitex to 10,000 decitex. The nylon monofilaments, particularly well suited for use in the upper band 68 are those sold by Shakespeare of Columbia, South Carolina, under the designation WN 125. The upper band 68 is generally constructed so as to have a monofilament bead count which it varies from 8 to 25 ends per 2.54 centimeters (EPI) or 3.15 to 9.84 ends per centimeter. Preferably, the rope count varies from 12 to 15 ends per inch or 4.72 to 5.91 ends per centimeter.

The filament or cords of the upper band 68 may remain thereon or in the opposite direction to those cords in the next underlying band layer 66. The band layers 62, 64, 66 containing the 4 + 3 string are constructed so as to have a rope end count ranging from 8 to 15 ends per inch (2.54 cm) (EPI) or 3.15 to 5.91 ends per centimeter. Preferably, the rope count varies from 9 to 12 ends per inch or 3.54 to 4.72 ends per centimeter. The pneumatic tires 50 of the present invention can be designed for various load scales. For example, the load scales can be E. F, G, H. J or L. Preferably, the load scales are H and J.

Example Three sets of 315 / 80R22.5 tires were tested for durability (Goodyear G391 Unisteel construction) (Load Scale H). Two tires from each group were tested. The rim of the first group (present invention) had three layers of steel reinforced band of which two were reinforced with 4 + 3x.41 rope at a 10-ply (2.54 cms) head count and the lower band was reinforced with 2 x 0.22 / 9 x 0.20 + 1 to a cape count of 12 ends per inch. A round nylon monofilament (10,000 decitex) reinforced the upper band layer to a count of 15 ropes per inch. The rim of the second group, control 1, was identical to the rim of the first group (present invention) except that the two of the three band layers in the band structures were reinforced with rope 3 x 0.365 / 9 x .034 + 1 to a head count of 9 ends per inch. The rim of the third group, control 2, had three layers of steel band of which two were reinforced with steel rope 3 x 0.265 / 9 x 0.245 at a count of 16 ropes per inch, the lower band was reinforced with 3 x 0.22 / 9 x 0.20 + 1 x 0.15 at a count of 12 ropes per inch and the upper band layer was reinforced steel 3 x 0.265 / 9 x 0.245 to a count of ropes 12 ends per inch. All the band angles were the same and the remaining design characteristic of all the tires were the same. The table below provides the test data for the average of the two tires in each group of two endurance tests. The first test is the Lisa wheel test of 304.80 centimeters, where the speed of the wheel is constant with increased loads over time. The results of the first test are reported in terms of kilometers to failure and normalized to the control results of two tires. The second test is known in the industry as ECE-R54. The results of ECE-R54 are reported in terms of hours to failure and normalized to the results control of 2 tires.

Control 2 Control 1 Present 3x.265 / 9X 3x.365 / 9X Invention .245 34 + 1 mono- 4 + 3X.41 filament monofilanylon mento nylon Km to Classification of failure 100 167 165 Hours to Classification of failure 100 120 137

Claims (10)

1. - A metallic rope for the reinforcement of elastomers, the metallic rope characterized by: (a) a core composed of four filaments; And (b) a three-filament cover where the diameter of each filament in the cord varies from 0.35 mm to 0.50 mm.

2. The metal rope of claim 1, characterized in that the length of laying of the four filaments in the core varies from 5 mm to infinity; and the length of laying of the three filaments in the cover varies from 5 mm to 50 mm.

3. The rope of claim 1, characterized in that the tensile strength of each filament is at least 3040 - (1200xD) MPa, where D is the diameter in millimeters of the filament. 4.- A pneumatic rim with a tread, frame layers that have radial cords, two side walls spaced at a distance, which in the axial direction determines the width of the rim section, two heels around each are flipped upwards, from the inside to the outside, the rope ends of the frame layers and a band structure which is circumferentially interposed between the tread and the frame layers, the band structure having a width that is substantially equal to that of the tread and having at least two radially overlapping layers d? elastomeric material reinforced with metal ropes, the metal ropes being parallel to each other and included at an angle of between 16s and 66a with respect to the equatorial plane of the rim comprising: the band structure having at least one layer that is reinforced with a rope metal characterized by (a) a core composed of four filaments; And (b) a three-filament cover where the diameter of each filament in the cord varies from 0.35 mm to 50 mm. 5. The rim of claim 4, characterized in that the length of laying of the filaments in the core varies from 5 mm to infinity; and the length of the filaments in the roof varies from 5 mm to 50 mm. 6. The rim of claim 4, characterized in that the tensile strength of each filament is at least 3040 - (1200xD) MPa where D is the diameter in millimeters of the filament. 7. The rim of claim 4, characterized in that the band structure comprises from 2 to 12 radially overlapping layers of elastomeric material. 8. The rim of claim 4, characterized in that the count of rope ends of the layer reinforced with the metal rope varies from 8 to 15 ropes per inch 83.15 to 5.91 ropes per cm). 9. The rim of claim 4, characterized in that the upper layer of the band structure is reinforced with a filament of organic polymer or rope. 10. The rim of claim 9, characterized in that the organic polymer is selected from the group consisting of nylon, polyester and polyvinyl alcohol.