MXPA99010855A - Light weight fiberglass belted radial tire - Google Patents

Abstract

A very light weight tire (10) has at least one radial ply (38) and a fiberglass belt structure (36) covered by an overlay (59) having cords (80) selected from the group of aramid, rayon, PEN, PET and PVA. The tire (10) has a very thin or reduced gauge (t) undertead (13). The tire (10) can be made having very low rolling resistance due to the combination of casing structure and the reduced rubber mass.

Description

"RADIAL RIM WITH LIGHT WEIGHT GLASS FIBER BELTS" TECHNICAL FIELD This invention relates to pneumatic tires. More particularly, with lightweight radial layer tires that have an elongation of less than 0.8.

BACKGROUND OF THE INVENTION Tire engineers have historically tried to build very durable box structures that can survive the serious driving conditions to which the tires are subjected by vehicle operators. Previously the tires were very heavy and used many layers or sheets of rope bias. The main purpose was simply to retain the air and avoid disinflation. Through a process of endless research to develop more durable and better rim constructions, new materials and better designs have been developed.

The introduction of the radial tire made it practical to develop tires that have so few as a layer of frame. The layer was contained radially by a belt structure. To improve the durability of the rims, these belt structures were developed to be mainly reinforced with steel. These belts reinforced with steel yielded and currently provide a very durable structure. These rims with steel belts have many benefits that make their use attractive. The steel cords are not sensitive to heat, that is, their physical properties are fairly constant despite the operating temperature of the rim. The steel cords are essentially inextensible and the cords can be made of very high strength with fine filaments that have excellent resistance to fatigue. However, these belts with steel cords on the rims have resulted in the need to add rubber directly above the belts in the area to which it is commonly referred to as the underlying raceway on the belt layers themselves. the areas of the edges of the belt, all in an attempt to maintain these steel cords so that they are not exposed or to separate structurally on the edges. In addition the glass reinforced cord has a tenacity of 10 grams per denier compared to the steel cord used in belts that have 4 grams per denier. The resulting effect has been that the radial rims with steel belts are in fact heavier using more rubber in the area of the bearing surface and in the shoulders of the rim. It is precisely in these areas in which a large part of the wear performance of the tread surface of the rim and the sensitivity to rolling resistance must be higher. The more rubber there is in this area, the greater the hysteresis effects and the higher the temperatures under operating conditions. It is now an object of tire designers to develop tires that generate lower fuel consumption of the car. This can be achieved by designing cold-working tires, which have low mass and low rotational inertia, while increasing tire handling performance and tread wear, and the engineer must ensure that the tread of the rim and the contact patch of the tread surface have a uniform pressure distribution in order to achieve uniform wear. With the advent of high performance tires that have very low elongations, the use of belt structures that have overlapping layers of synthetic nylon or aramid cords has become common. To further achieve high-speed operation, the thickness of the running surface has been kept to a minimum. The mass of the thick rolling surfaces at high speeds simply wants to get rid of the rim. As these tires are pushed towards the design limit of the tire known to the engineer, you must rethink about all the parameters of the tire. In some cases, this means returning and re-analyzing the concepts that were used in the transfer of what was abandoned as a result of those in the technique that follows a different trajectory. One of these approaches that until now had been lost was favored among the tire engineers was the use of fiberglass straps that even when a very good material for straps lost be favored when the steel straps were introduced. The primary collapse of fiberglass belts was their apparent lack of durability. Even in the slanted tires of 1970, the use of fiberglass breakers had technical concerns. In US Pat. No. 3,762,458 issued October 2, 1973 in favor of Yoshida et al., It was stated that "glass is superior to organic fiber rope in heat resistance, dimensional stability and modulus of elasticity, and when the rubber is reinforced with glass rope and used as a breaker layer of a pneumatic tire, the rim is excellent in various properties, particularly it is excellent in abrasion resistance (road test) and turning power ". Yoshida and others, then goes without detail of why the fiberglass strings were disadvantaged in their use as breaker cords. He cites three serious drawbacks of the use of fiberglass breakers. "First, when a car is running, the dynamic bending transformation and shock transformation of the rim occurred due to the condition of the road surface and the glass strings are broken or crushed." Second, materials generally strangers, such as nails, pieces of glass and gravel penetrate the rim and reach their ripper layer during the use of the rim, particularly at the end of use, in this case, if the rim has a rupturing layer composed of conventional organic fibers , such as nylon fibers, rayon, polyester and vinyl (polyvinyl alcohol), etc., the rim break occurs only in the portion in which the foreign material has penetrated, on the contrary, if the rim has a rupturing layer of glass rope, the glass ropes are crushed by the penetrated foreign materials and the breakage of the glass ropes extends along the glass rope breaker layer. of annoyances or serious problems. In order to solve these inconveniences, it has been tried to place the organic fiber cords such as nylon cords on the side of the running surface of the glass rope breaker layer. However, until now a satisfactory result has not been obtained. In addition to these inconveniences, of the glass rope, the inventors have also found a third inconvenience of the glass rope that is peculiar to the glass rope and that does not occur in an organic fiber rope. That is, in the vulcanization step of the rim, the next step can be carried out. Namely, a tire is vulcanized at an elevated temperature and under high pressure, and then the tire is drawn into the atmosphere at room temperature and under atmospheric pressure and then the tire is applied with air pressure to the inner side under a high pressure to stabilize the size of the tire. When the rim is drawn into the atmosphere at room temperature, the strings composed of organic fibers other than fiberglass, such as rayon, nylon, vinyl and polyester fibers, etc. which were used as a reinforcing material of the rim, that is, they were used in a frame placed on the inner side of the breaker, they shrink considerably. As a result, the glass rope breaker placed directly adjacent to the rope layer of organic fiber coated with rubber (frame) is violently compressed, and the glass filaments that make up the glass cord of the breaker are compressed to decrease their toughness and They break when the car is running. For example, on a rim composed of two kinds of layers of a frame layer reinforced with organic fiber rope and a glass rope breaker, the glass cords constituting a glass rope breaker layer placed on the side of the frame are inferior in tenacity to the glass strings that constitute another layer breaking glass rope placed on the side of the running surface. In addition, when the organic fiber ropes having different shrinkage capabilities, for example, nylon rope or rayon rope is used as a frame rope, the nylon rope having a higher shrinkage decreases the tenacity of the rope of glass more than the rayon string. Further, still in the tire vulcanization treatment with conventional slanted belts wherein the rope layer of organic fiber coated with rubber such as rubber-coated nylon rope layer is placed on the running surface side of the rope breaker of glass, the above described phenomenon occurs between the glass rope breaker and the organic glass rope layer coated with rubber whereby the glass filaments are broken. Because when the tire cools down, the above-described organic fiber rope shrinks considerably. "These three problems were supposedly solved by Yoshida and others, as mentioned below:" Among the three previously described inconveniences of the rim that has the Glass rope breaker layer, the first inconvenient has already been solved by the inventors. That is, in order to decrease the bending transformation and shock transformation of the glass rope, a layer of rubber reinforced with short cut fiber is placed on the running surface side of the glass rope breaker layer. In order to solve the second inconvenience, that is, the problem of the resistance of the plunger against foreign materials, the inventors have confirmed that the arrangement of the rubber layer reinforced with cut fiber cuts on the side of the tread surface of the layer Glass rope breaker has a higher effect than the arrangement of a single rubber layer or a layer of cord covered with rubber. In addition, in order to solve the third inconvenience, the inventors have found that the following arrangement is more effective. That is, the glass rope breaker layer is not placed directly adjacent to the organic fiber cords which have a high shrinkage capacity but this layer having low shrinkage and does not transmit the shrinkage to the organic fiber cords towards the layer Glass rope breaker is placed between the rope layer of organic fiber coated with rubber (frame) and the glass rope breaker layer. "Therefore, Yoshida and others tried to retain the use of glass fiber breakers in the bias rims.The use of fiberglass straps on the radial tires was even more challenging.In the North American Patent granted to Christian MLL Bourbon de Carbon de France, de Carbon explains "the radial rims essentially comprise a radial frame, constituted of curved members that are straight in the central planes of the cover, in combination with a non-extensible belt comprising a reinforcement that is flexible in the radial direction (the direction perpendicular to the surface of the running surface) but which has high rigidity - longitudinal and transverse (that is, in directions parallel to the running surface), the non-extensible belt is automatically tensioned by internal pressure and thus has a considerable equatorial bonding effect on the curved members of the frame, even when the rim pneumatic is in resting position and is not subjected to any crushing load. "The DeCarbon solution to the problem of the radial rim belt structures was in use of flattened ropes having a width of approximately 1 millimeter, the highly flattened ropes being of steel or fiberglass plastic oriented at transverse angles of approximately 45 mm. 60 ° C. As you can easily see this solution were very complicated, and eventually lost any commercial interest due to the complexity and simpler success simultaneous steel belts.The present invention shows that the use of fiberglass straps that it can not be made commercially acceptable if the fiberglass is used with a combination of other components that ensure that the glass cords are not damaged during manufacture by ensuring that the thermal shrinkage differentials created during subsequent vulcanization, cooling and re-inflation do not They are transmitted to the glass ropes. Not only are they commercially acceptable, but they can also provide surprisingly beneficial improvements in tire weight and reduced rolling resistance.

COMPENDIUM OF THE INVENTION A rim 10 of radial layer exhibiting very light weight and low rolling resistance has an elongation in the range of 0.2 to 0.8. The rim 10 has a pair of parallel annular bead cores 26; one or more layers 38 of radial frame, at least one layer 38 of radial frame being wound around the bead cores 26; a belt structure 36 positioned radially outwardly from one or more radial frame layers 38 in a crown area of the rim 10; and an overlay 59 having a width that essentially coincides with the width of the belt structure 36. A running surface 12 is placed radially outwardly of the superposed layer 59 and a side 20 is placed between the running surface 12 and the heels 26. The superimposed layer 59 has filaments or cords 70, the cords 70 being selected from a group. of materials, the group being of rayon, PET, aramid, PEN or PVA, embedded in an elastomer. The belt structure 36 is made of two layers 50, 51 reinforced with fiberglass rope having rope angles within the range of 18 ° to 26 °, preferably of about 22 °. Layers 50, 51 are simple cut layers that do not require bent side edges. The superimposed layer 59 is preferably spirally wound radially outward from and adjacent the belt structure 36. The superimposed layer 59 is made of a continuous strip of reinforcing tape having a width of 1.27 centimeters to 3.81 centimeters having from 4 to 45 parallel reinforcing filaments or a cord 70 embedded therein. In the preferred embodiment, the superimposed strings 70 are made of aramid, however, strings of high tensile strength, low thermal shrinkage, such as rayon, PEN, PET or PVA can also be used. The rim 10 according to the invention has a very thin underlying running surface 13, the underlying rolling subsurface 13 being measured from the radially external surface of the cords 70 of a superimposed layer 59 to the full depth circumferential groove. The thickness (t) of the superimposed tread 13 is less than 2 millimeters, preferably greater than 1 millimeter. To improve handling performance, the rim 10 employs a hard apex 46 extending radially outward of each bead core 26 and adjacent to the layer 38. The apex 46 has shore hardness D greater than 50. To improve stability side, the rim 10 can employ two side insert pieces, one insert being left on each of the sides 20. Each side insert has two layers 52, 53 of biased cord reinforcements. The cords of the first layer 52 are oriented in an equal but opposite manner on the cords of the second layer 53, the two layers 52, 53 interposed between the apex 46 and the upturned piece 32 of the frame layer 38. The strings of each layer are oriented at an angle of 25 ° to 60 ° in relation to the radial direction. Preferably, the first and second layers 52, 53 have a radially inner end 54 and a radially outer end 55, the respective ends 54, 55 of a layer being staggered relative to the ends 54, 55 of the opposite layer. The radially outer end 55 of a layer is placed at approximately half the SH section height of the rim or at the h site, as shown.

The rim 10 further has a noise-damping rubber strip 42 which lies below one edge of the belt and which extends to approximately 50 percent of the section height SH of the rim 10. The strings 41 of a or more of the frame layers 38, may be selected from the group of rayon, nylon, PEN, PET, steel or aramid. The preferred rim 10 used a rayon frame layer 38. The rim 10 using the novel combination described above can be made very light in weight compared to conventional rims. The rim 10 of the invention can demonstrate excellent performance, particularly high speed handling with the additional benefit of very low rolling resistance.

BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a cross-sectional view of the rim 10 of the preferred embodiment in accordance with the present invention.

DEFINITIONS "Elongation" means the ratio of its section height to its section width. "Axial" and "axially" means the lines or directions that are parallel to the axis of rotation of the rim. "Heel" or "Heel Core" generally means that part of the rim comprising an annular tension member, the radially internal heels are associated with the retention of the rim to the edge that is wrapped by layer cords and configured with or without other reinforcement elements such as fins, chisels, apices or filling or loading materials, tip protectors and excoriators. "Belt Structure" or "Reinforcement Belt" means at least two layers or annular sheets of parallel strings, woven or non-woven, that lie below the running surface, not anchored in the heel, and have both angles of left rope as right within the scale of 17 ° to 27 ° with respect to the equatorial plane of the rim. "Circumferential" means lines or directions extending along the perimeter of the surface of the annular tread surface perpendicular to the axial direction.

"Frame" means the structure of the rim in addition to the structure of the belt, running surface and underlying running surface, but including the heels. "Case" means the frame, belt structure, heels, sides and all other components of the rim except the running surface and the underlying running surface. "Excoriators" refers to narrow strips of material placed around the outside of the heel to protect the layers of rope from the edge, which distributes bending above the edge. "Cord" means one of the reinforcing strands of which the layers of the tire consist. "Equatorial plane (EP)" means the plane perpendicular to the axis of rotation of the rim and passing through the center of its running surface. "Footprint" means the patch or contact contact area of the tread surface of the rim with a flat surface at zero speed and under normal load and pressure. "Inner lining" means the layer or layers of elastomer or other material forming the inner surface of the rim free of tube and containing the inflation fluid within the rim.

"Normal Inflation Pressure" means the specific design inflation pressure and the load assigned by the appropriate standards organization for the service condition for the tire. "Normal Load" means the specific design inflation pressure and the load assigned by the organization of appropriate standards for the service connection for the tire. "Layer" means a layer of parallel strings coated with rubber. "Radial" and "radially" mean directions radially toward or away from the axis of rotation of the rim. "Radial Layer Tire" means a pneumatic rim with belts or circumferentially restrained in which at least one layer has cords extending from bead to bead that are placed at rope angles between 65 ° and 90 ° with respect to the equatorial plane of the rim. "Section Height" means the radial distance from the nominal edge diameter to the outer diameter of the rim in its equatorial plane. "Section Width" means the maximum linear distance parallel to the axis of the rim and between the outside of its sides when and after it has been inflated at normal pressure for 24 hours, but unloaded, excluding elevations of the sides due to placement of labels, decoration or protective bands. "Highlight" means the upper portion of the side just below the edge of the running surface. "Side" means that portion of the rim between the running surface and the heel. "Rolling Surface Width" means the length of the arc of the running surface in the axial direction, ie, in a plane parallel to the axis of rotation of the rim.

DETAILED DESCRIPTION OF THE INVENTION The rim 10 according to the present invention employs a singular structure. The rim 10, as illustrated in Figure 1, is a rim for a radial passenger car or a light truck; the rim 10 is provided with a portion 12 of tread surface engaging the earth terminating at the shoulder portions at the lateral edges 14, 16 of the running surface 12, respectively. A pair of side portions 20 extend from the side edges of rolling surface 14, 16, respectively and terminate in a pair of bead regions 22. The upturned ends 32 of at least one radial layer 38 of the frame reinforcement structure 30 are wound around the bead cores 26 and extend radially outward to a terminal end 33. The upturned part 32 can terminate at approximately the radial location of the maximum section width in the embodiment of Figure 1. The rim 10 may include a conventional interliner 35 that forms the inner peripheral surface of the rim 10 if the rim is to be tube free. In the preferred rim 10, the inner liner 35 is made of 100 percent bromobutyl. As shown in Figure 1, the rim 10 can employ a single synthetic layer wound above the bead core 26 and extending to a raised upwardly turned end 33 positioned at approximately the radial location of the maximum section diameter (h). ). Positioned circumferentially around the radially outer surface of the frame reinforcement structure 30 below the running surface portion 12 there is a tread surface reinforcing belt structure 36. In the specific embodiment illustrated, the belt structure 36 comprises two cut belt layers 50, 51 and the cords 80 of the belt layers 50, 51 are oriented at an angle of approximately 22 ° with respect to the middle circumferential center plane of the rim. The cords 80 of the belt layer 50 are placed in a direction opposite to the middle circumferential center plane and that of the cords 80 of the belt layer 51. However, the belt structure 36 can comprise any number of belt layers and the cords 80 can be placed at any desired angle, preferably within the range of 18 ° to 26 °. An important feature of the layers 50, 51 is that each layer 50, 51 is a single cut layer, with no side edges being bent. The belt structure 36 provides lateral stiffness through the width of the belt so as to minimize the lifting of the running surface 12 from the road surface during the operation of the rim 10. In the illustrated embodiments, this is achieved by having the cords 80 of the fiberglass belt layers 50, 51, and preferably glass fiber 660 / lTex have a construction density of 15-25 EPI. The frame reinforcement structure 30 comprises at least one reinforcing layer structure 38. In the specific embodiment illustrated in Figure 1, there is provided in reinforcing layer structure 38 with an upturned piece 32 of radially outer layer, and this layer structure 38 preferably has a layer of parallel cords 41. The cords 41 of the reinforcing layer structure 38 are oriented at an angle of at least 75 degrees with respect to the middle circumferential center plane CP of the rim 10. In the specific embodiment illustrated, the cords 41 are oriented at an angle of approximately 90 degrees with respect to the mid circumferential CP center plane. The cords 41 can be made of any material normally used for rope reinforcement of rubber articles, for example, and not by way of limitation, of rayon, nylon and polyester, aramid or steel. Preferably, the cords are made of a material having a high adhesion property with rubber and high heat resistance. For the strings 41 of the frame, organic fiber cords with an elastic modulus within the range of 250 to 1400 kgf / square millimeter, such as nylon 6, nylon 6-6, rayon, polyester or high modulus cords, are commonly used. In the case of 340-to-2100dTex, these fiber cords are used, preferably at a density of 17 to 30 EPI. Another high modulus fiber includes aramid, vinyl, PEN, PET, PDA, carbon fiber, fiberglass, polyamides. Alternatively, steel strings of very high tensile strength steel having fine diameter filaments exhibiting excellent fatigue resistance could be used. In the specific preferred embodiment illustrated, the cords 41 are made of rayon. The cords 41 have an E modulus of X and a Y elongation percentage. The preferred rayon cord 41 has X values within the scale of at least up to 10 GPa and percentage of elongations within the scale commonly found in the specific material of the rope. As further illustrated in Figure 1, the bead regions 22 of the rim 10 each have first and second essentially annular inextensible bead cores 26, respectively. The bead core is preferably constructed from a single steel or monofilament wire continuously wound. In the preferred embodiment, high-tensile steel wire with a diameter of 0.97 millimeters is wound on four radially internal to radially outer layers of four wires respectively, forming a 4x4 construction. Placed within the bead region 22 and the radially internal portions of the side portions 20 are the high modulus elastomer apex insertion pieces 46, positioned between the frame layer reinforcement structure 38 and the ends 32 turned upwards. , respectively. The elastomeric apex insertion pieces 46 extend from the radially outer portion of the bead cores 26 respectively to the side portion, which decreases gradually in cross sectional width. The elastomeric inserts 46 terminate at a radially outer end at a distance G radially inward from the width of the maximum section of the rim at location (h), as shown in Figure 1. In the specific embodiment illustrated, the elastomeric apex insert 46, each extends from its respective bead cores 26 to a distance G of approximately 25 percent (25%) of the section height of the rim. For purposes of this invention, the maximum section height SH of the rim will be considered as the radial distance measured from the nominal edge diameter NRD of the rim to the radially most outward portion of the running surface portion of the rim. tire. Also, for the purposes of this invention, the nominal edge diameter will be the diameter of the rim, as designated by its size. In a preferred embodiment of the invention, the bead regions 22 further includes the apex insert 46 and the tip 32 turned upwardly of the layer.

- The member or members reinforced with rope 52, 53 have a first end 54 and a second end 55. The first end 54 is axially and radially inward from the second end 55. The member or members 52, 53 reinforced with rope increase in distance radial from the axis of rotation of the rim 10 as a function of the distance from its first end 54. In Figure 1 illustrated, the rope reinforced member comprises two components 52, 53 having a width of approximately 4 centimeters. The axially internal component 52 has a radially internal end 54 that is radially at or slightly above the first and second bead cores 26. The axially external component 53 has a radially inner end that is radially outwardly of the outer surface of the bead core 26 by approximately 1 centimeter. The axially internal and axially external components 52, 53 preferably have a rayon, nylon, aramid or steel cord reinforcement in the preferred embodiment, and 1400 / 2dTex rim nylon cords were used. The second end 55 of the cord reinforcement member 53 is positioned radially outwardly of the bead core 26 and the termination 33 of the end 32 turned upwardly of the first layer 38 and is positioned radially at a distance of at least 50 by - - cent of the SH section height, as measured from the nominal heel diameter. The cords of the members 52, 53 are preferably inclined at an included angle relative to the radial direction within the range of 25 ° to 75 °, preferably to 55 °. If two members are used, the bead angles are preferably the same, but they are placed opposite each other. The cord reinforcement member 52, 53 improves the handling characteristics of the rim 10 of the present invention. Members 52, 53 greatly reduce the tendency for the car to over-turn, a significant problem encountered in conventional tires that are driven while in a deflated or inflated condition in an underlying manner. A cloth-reinforced member 61 can be added to the bead regions 22 of the rim 10. The cloth-reinforced member has first and second ends 62, 63. The member is wound around the first layer 38 and the bead core 26. Both the first and the second ends 62, 63 extend radially above and away from the bead core 26. The side portions 20 of the rim 10 of the preferred embodiment are provided with a pair of first cushioning materials 42 noise absorbers. The first noise damping filler materials 42 are used between the interliner 35 and the reinforcement layer 38. The first filler or filler materials 42 extend from under each strap of the belt in the jump region of the rim 10 until radially inward of the end 55 of the reinforced member. As illustrated in the preferred embodiment of the invention, as shown in Figure 1, the side portions 20 each include a first filler or noise damping filler 42 and an apex 46 insert. Filling or filling materials 42 are placed as described above. The apex insert pieces 46 are positioned between the first layer 38 and the upturned ends 32 of the layer 38, respectively. For the purposes of this invention, the width of the maximum section (SW) of the rim is measured parallel to the axis of rotation of the rim from the axially external surfaces of the rim, excluding signs, ornaments and similar materials. Also, for the purposes of this invention, the width of the running surface is the axial distance through the rim perpendicular to the equatorial plane (EP) of the rim, as measured from the rim footprint inflated to the tire pressure. maximum normal inflation, to a load classified and mounted on a wheel for which it was designed.

The rim 10 illustrated in Figure 1 of the rim of the preferred embodiment has an overlay 59 of fabric placed around the tread surface reinforcing belt structure 36. For example, two spirally wound layers ideally having PEN, PET, PVA, rayon or aramid cords can be placed above each of the reinforcing strap structures 36, with the lateral ends extending beyond the lateral ends of the reinforcing straps 36. 36 belt structures. Alternatively, a single layer of spirally wound reinforced fabric can be used as a superimposed layer. The rim 10 of the preferred embodiment employed spirally wound aramid ropes 70 of flexten 1670 / 3dTex or more preferably 1100 / 2dTex. The aramid material has a modulus of elasticity considerably higher than nylon and consequently results in a stronger rim reinforcement than the two nylon layers. Nylon exhibiting high thermal shrinkage should be avoided because its use will damage the fiberglass strings 80 of the belts 50, 51. Applicants have found that an increase in high speed capacity can be achieved in a rim with the single layer of aramid remaining above that has at least 14 EPI, preferably, approximately 17 EPI. Generally, the use of an aramid material in passenger car tire applications is avoided due in part to the fact that the material exhibits noise-deficient properties that make sounds echo through the relatively thin sides of the tire. rim of passenger car. The rim of the applicants of the present invention employs a noise-deadening insert 42 on the sides 20, which significantly dampens the noises generated by the rim. These noise damping sides 20 allow the use of an aramid overlay without experiencing unacceptable noise levels. The cords 80 of the superimposed layer 59 can alternatively be made of rayon, PET, PEN or PVA. A PEN filament having a density of 240dTex to 2200dTex can be employed, more preferably, 1440 / 2dTex which has both a twist of yarn and a string of between 4 and 12 tpi, preferably 7Z / 9S can be used since then . The apex fill or insert materials 46, as shown, can be made from one or two or more different elastomeric materials. Preferred embodiments employed only one compound or material in the apex insert pieces 46 that extended from the bead core 26. The material of the preferred apex insert is very hard having a shore hardness - D of 50 or more, preferably 50 to 55. The hardness of the insert 46 was achieved by crosslinking the mixed reinforcing resins to a known common mixing process to achieve a high hardness that allows a minimum amount of the material to be use to form the apex insert 46. The inserts 46 can alternatively be loaded with short fibers, which are preferably oriented at an angle of at least 45 ° to improve the radial and lateral stiffness of the insert, preferably the fibers are radially oriented. Preferably, the short fibers are made of textile or synthetic materials such as rayon, nylon, polyester or aramid. These short fibers can be directed or placed radially at skewed angles, preferably at least 45 °, but they should not extend circumferentially. The galling of the rim 10 in the lower bead region radially outwardly of the structure 30 of the frame adjacent the edge flange can be minimized, especially during the use of the rim in an inflated condition, not completely, by providing a portion. 60 of a hard rubber excoriator. The belt structure 36 has belts 50, 51 which preferably use 660 / lTex glass fiber at a density of 15 to 25 EPI. The belts 50, 51 had a width of about 98 percent of the rope width of the mold tread surface which is commonly referred to as the tread surface arc width. To further improve the operation of the rim 10 and the lightweight particulars, the tread surface 12 was constructed having a minimum thickness or caliper (t) of the underlying tread surface 13. Conventionally, for high performance of the car rim of passengers the underlying running surface is reduced to between 2 and 5 millimeters. The rim of the present invention had an underlying rolling surface less than 2 millimeters, preferably about 1 millimeter, as measured from the radially outer strings 70 of the superimposed layer 59 to the bottom of the full depth circumferential groove, as is shown in Figure 1. To ensure that the rim 10 of the invention reduced the inherent stresses created when molding a rim having glass fiber belts 50, 51, it was determined that the mold must be wide and flat on the surface rolling. The radius of the running surface of 315 millimeters and a tread width of 141 millimeters was evaluated with - - acceptable results At a tire size of 195 / 65R15 91V, a radius of running surface of 914 millimeters and a runway width of 152 millimeters yielded superior results. The inventors believe that the flat rolling radius greater than 300 millimeters across the width of the tread surface of approximately 125 millimeters or more will provide acceptable results. More preferably, the radius R of the running surface must be greater than 500 millimeters for the width of the cord of the running surface of more than 150 millimeters, more preferably R must be at least 750 millimeters. This wide flat tread arch allows the strings 80 of the belt to experience minimal thermal shrinkage distortion that could damage the strings of layer 51, adjacent to shell 38 of the frame. That is, in combination with the layer cords 41 of the low thermal shrinkage and an overlay layer 59 of such low thermal shrinkage means that the rim 10 can be manufactured and placed in use in such a way that the glass fiber belts 50, 51 will survive. Exposure to thermal expansion and contraction. A test tire 10 having a size 195 / 65R15 91V was manufactured with conventional steel belts and the weight of the rim was 9.4 - kilograms. The rim of the same size manufactured in accordance with the present invention, and having a weight of 7.2 kilograms that depends on the tuning of the rim 10 when using the concepts of the invention described above have rendered weights within the scale of 6.9. to 7.4 kilograms. This reduction in weight in and by itself was a very beneficial improvement in relation to the prior art, since it reduces the contribution of kinetic energy of the rim, decreasing both the transfer and the kinetic energy of rotation, and thereby reducing the fuel consumption. In addition, the reduced weight of the tire mass allows car manufacturers to redesign the suspension with reduced weight components to improve the car's weight, performance and handling. The rim of the present invention provided an improvement in rolling resistance of 10 percent versus a classic construction made in the same mold with the same tread compound. Improvements in tread wear were observed from 0 percent to 10 percent in a normal tire wear test 10 versus conventional construction. The rim 10 was found to be less sensitive to wear of the wheel position. He - wear of the shoulder of the steering position and the wear of the center line of the position of the rear wheel when loaded lightly were much less pronounced on the rim 10 of the invention when compared with the rims of the prior art. The flat spots of the rim of the invention had been greatly improved in relation to the rims of the prior art in terms of the amount of time required to recover a gear free of alterations. Flat staining is a condition that occurs in a common manner when a vehicle after being driven stalls causing the hot rim to cool in such a way that the structure has a locally flattened box structure. More importantly, the rim of the invention has demonstrated excellent durability and has passed the plunger test, high V speed, road durability of the frame, external resilometer, curb crash test, road plunger and road tests. qualification of DOT and ECE R30 legally required. Although certain embodiments and representative details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

Claims (20)

R E I V I N D I C A C I O N S

1. A pneumatic radial tire rim having an elongation of 0.2 to 0.8, comprising a pair of parallel annular beads, one or more radial frame layers, at least one radial frame layer having a pair of upturned sections that they are wound around the heels, a belt structure positioned radially outwardly from one or more layers of radial frame in a crown area of the rim, and a jacket layer having a width essentially coinciding with the width of the structure of the tire. belt, a running surface radially outwardly of the superposed layer, and a side placed between the running surface and the heels, wherein the running surface comprises filaments or reinforcing cords, the cords are selected from a group of materials , being the group of rayon, PET, aramid, PEN or PVA, embedded in an elastomer, and the belt structure is made of two layers reinforced with fiber rope. idrio that have rope angles within the range of 18 ° to 26 °.

2. The pneumatic tire of claim 1, wherein the superimposed layer is spirally wound radially outwardly from the belt structure and comprises a continuous strip of elastomeric reinforcing tape having a width of 1.27 centimeters to 3.81 centimeters, and 4 to 45 parallel reinforcing filaments or cords embedded in it.

3. The pneumatic tire of claim 1, wherein the reinforcing filaments are filaments of PEN having a density of 240dTex to 2200dTex.

The pneumatic tire of claim 1, wherein the PEN reinforcement cords have a torsional multiplier of 5 to 10.

The pneumatic tire of claim 1, wherein the reinforcement of PEN is the cords of 1440 / 2dTex that have a twist of thread and rope of between 4 to 12 tpi.

6. The pneumatic tire of claim 1, wherein the reinforcing filaments of the superimposed layer are aramid.

7. The pneumatic tire of claim 5, wherein the reinforcing filaments of the superimposed layer are of flexten 1100 / 2dTex.

The pneumatic tire of claim 6, wherein the filaments have one end per 2.54 centimeters (EPI) of about 15 to 30.

The rim of claim 1, wherein the running surface has an underlying running surface. , as measured from the surface radially - outer of the strings of the overlying layer to a full depth circumferential groove, the underlying running surface having an average thickness of less than 2 millimeters.

10. The rim of claim 8, wherein the underlying rolling surface has a thickness of about 1 millimeter.

The rim of claim 1, further comprising an apex extending radially outwardly above each of the bead cores and adjacent to the layer, the apex having a shore D hardness greater than 50.

12. The rim of claim 10, further comprising two side insertion pieces, an insert on each side, each insert is constituted by two elastomer layers reinforced by cords to the bias, a first layer being oriented equal, but opposite to the second layer, and the two layers being interposed between the apex and the upturned section of the frame layer.

The rim of claim 11, wherein the first and second layers have biased rope angles of 25 ° to 60 °.

The rim of claim 12, wherein each first and second layer have a radially inner end and a radially outer end, the respective ends of a layer are staggered with respect to the ends of the opposite layer, the radially outer end of a layer being positioned approximately half the height of the section of the rim.

15. The rim of claim 1, further comprising an intermediate liner and an elastomeric noise-absorbing insert, the insert being between the inner liner and the layer below one edge of the belt, and extending to approximately 50 percent of the section height of the rim.

16. The pneumatic tire of claim 1, wherein the shell layers have radial rayon cords.

17. The pneumatic tire of claim 1, wherein the frame layers have radial nylon cords.

18. The pneumatic tire of claim 1, wherein the frame layers have PEN radial cords.

19. The pneumatic tire of claim 1, wherein the frame layers have radial aramid cords.

20. The pneumatic tire of claim 1, wherein the frame layers have radial steel cords.