BA NDAENTED DESCRIPTION OF THE INVENTION The invention relates to power transmission bands, but more particularly, the invention relates to a textile rope and its treatment as a tension member embedded in a urethane body, of a power transmission band, and more preferably a toothed belt of power transmission. The textile rope has long been used as a tension reinforcement in a power transmission band; The rope is embedded in a body of elastomeric material of the band forming the band and has a treatment that promotes adhesion with the band material and prevents the degradation of the textile filaments that form the rope, however the treatment may be the rope too rigid, which significantly damages the bending module of either the rope or the band. As a result, there is no single string treatment that works well for all bands. Generally speaking, a new treatment should be established where, whether the material of the rope or the band, change in an important way. For example, when the material of the rope is cotton, rayon or nylon, and the material of the band is rubber such as neoprene, the treatment of the rope may include sinking the rope in a resorcinol-formaldehyde latex (RFL), as that continues to dip the rope into a glue formed of rubber and a solvent. When the material of the rope is polyester, and that of the band is rubber, the treatment of the rope may include dipping the rope in isocyanate methylene di-phenylene (MDI). When the material of the rope is fiberglass and the material of the rope is rubber, the treatment of the rope may include sinking the rope in silane to what follows, sinking the rope (RFL). When the material of the rope is aramid and the material of the band is rubber, the treatment can include wetting the rope in an epoxy, to which it continues to sink it in (RFL), to what follows to do it in a glue or that it returns sticky rubber dissolved in a solvent. The change of material of the band can also have an important impact in the treatment of the rope or the selection of the rope, for example, castable urethane as material of the band, can form a significant part of the treatment of the rope, when the Urethane is in liquid state can penetrate the interstices of the rope. However, the urethane in its cured state as a high modulus band material can cause a special rope material to become unacceptable when it penetrates the interstices of the rope because the rope thus penetrated can have an unacceptable bending modulus. Also the penetrating urethane, can transfer too high an effort to the filaments that form the rope to cause unacceptable breaking of the filaments, which would result in the failure of the rope. In some cases, cotton and fiberglass are unacceptable as rope materials for that reason to be used with urethane as the web material. Due to the problems presented above and associated with the rope material, the rope treatment has taken a zic zac and prediscible trajectory in the last more than 30 years, since the urethane was first introduced and used effectively as a material of band in 1964. Referring to the 1964 U.S. Patent No. 3,138,962 (Haines et al.), a power transmission belt with a textile rope as a tension reinforcement is embedded in a band body of urethane material. The identified rope materials are Dacron (polyester), cotton, nylon, rayon and fortisspa, while the preferred rope material of the day was polyester. The characteristic of the invention of Haines is the treatment of the rope where the uncured urethane is emptied, penetrates completely in the rope and completely fills the interstices formed by the fiber that structures the rope. In other words in 1964, the condition of the rope treatment was to completely fill the interstices of the rope 100%, with urethane material for band. Such treatment of filling the rope 100%, lived little because the flexural modulus of the rope was too high, which resulted in other developments in the treatment of the rope. Referring to the American patent of 1967, 3,349,634 (Terhune et al.), A power transmission belt with a textile rope as a tension reinforcement was embedded in a band body made of urethane material for the belt. The material of the identified rope was nylon, rayon or polyester, while the preferred material was the latter. Terhune recognized that the complete penetration treatment of the interstices of the rope with urethane, tended to form a solid mass of the rope and the band and thus reduced the elasticity. The characteristic of Terhune is a rope treatment, where it is submerged in a material that completely impregnates the fiber comprising the rope. The material where it was submerged in the time of Terhune, was isocyanate, during the manufacture of the band, the liquid urethane material of the band penetrated the rope at a depth of no more than 10% of the rope to complete the treatment of the rope in place, this pre-treatment of filling the core of the rope up to 90% of its diameter with isocyanate and completing the treatment by filling the remaining 10% of its diameter with urethane, remains in use today for polyester rope material. In the US patent of 1975, number 3,894,900 (Redmond), a power transmission band with a rope reinforcement of aramid material is embedded in a strip body of band urethane material. The feature of Redmond's invention concerns an elastomer-free surface for the power transmission belt made of urethane that can be emptied as web material. The textile cord of the aramid material, (among a list of others), is embedded in the body of the band as a tension reinforcement, Redmond recognizes a string treatment as the string can be impregnated with a suitable material. however Redmond does not identify the types of material suitable for the aramid rope or how the rope should be impregnated. The combination of aramid rope material sold under the Kevlar trademark, among others list, and urethane material is presented in the 1989 US patent, 4,838,843 (Westhoff), the rope treatment presented by Westhoff, is that the rope is embedded and basically surrounded by urethane, so that the rope is linked to the urethane with a binding value of 42kg / cm2. Thus, the treatment of the rope comprises liquid urethane of the band material which penetrates a portion of the interstices formed by fibers comprising the rope. All of the aforementioned patents, except Westhoff, give a laundry list of identification of the rope materials which has little relation to the invention presented particularly and similarly many give an identification list of the materials of the band. Rope and band materials are added chronologically to the laundry list as new materials are developed. The US patent of 1996, 5,209,705 (Gregg) also uses a laundry list to identify rope materials and web materials. For an invention concerning the orientation of the teeth of the belt or gears for a power transmission belt, it provides a list of rope materials, such as fiberglass, carbon, steel, polyester, high tenacity rayon or preferably Poly Aramid, similarly provides a list of web materials such as polychloroprene, polyurethane, NBR, IIR, IR, SBR, SCM, EPDM and others. Gregg implies that band and string materials could be used in all possible combinations, but it is known from industrial experience that not all combinations of band and string materials work effectively. One of the possible combinations of Gregg, is a material of rope of carbon fiber and a material of urethane, the problem is that Gregg, does not present a string treatment for any of the possible materials of rope or of the possible combinations with the band material. More particularly Gregg does not disclose what type of rope treatment is necessary to protect and prevent extremely cracking carbon fibers from being damaged by being subjected to a cyclic bend in a urethane body of a power transmission toothed belt. The present invention is directed to the solution of the problem wherein, a carbon fiber rope material is embedded in a band body of urethane material, the problem is solved by a treatment of the rope when it is stuffed into a body of band of urethane material. According to the invention, a synchronous power transmission belt is provided, comprising a band body of cast or cast urethane material forming band teeth in the body and spaced apart in one section, a tear-resistant fabric reinforcement disposed along the peripheral surfaces of the teeth of the band, a spiral coiled rope tension member embedded in the band body and a carbon fiber tow, a rope treatment essential to the invention comprises that the rope take a minimum amount of the web material when the web is cast, the webs constructed according to the invention show an unexpected improvement over the prior art webs particularly those constructed with a tensor member constructed of aramid fiber. Other features and advantages of the invention will be apparent after looking at Figs. and the description thereof, wherein: FIGURE 1 is a partial longitudinal sectional view partly cut away with cross section showing a band of the invention with a hollow cord and teeth of the band. FIGURE 2, is an enlarged partial cross-sectional view taken along line 2-2, of FIG. 1, showing an embossed rope. FIGURE 3 is a view, similar to FIG. 2, but showing an embossed rope of the prior art. FIGURE 4 is a chart showing the operation of the band as a function of the treatment of the rope for the bands according to the invention and bands of the prior art. Referring to Figs. 1-2, band 10 of the invention has a body 12 of cast urethane strip material with band teeth 14 formed in the body and spaced a certain distance P. The teeth are covered with a cloth 16, resistant to Wear disposed along the peripheral surfaces of the teeth of the band, a tension member 18, of a helical cord is embedded in the body of the band, the band is manufactured using known processing techniques. The body is cast from a liquid urethane material which upon curing has the physical characteristics required for a power transmission band, for example, the urethane may have the properties presented in US Pat. No. 4,838,843 to Westhoff where the web material of urethane has a tensile modulus of at least 105 kg / cm2, and a 100% elongation when cast using standard ASTM procedures. The urethane can have a tensile modulus of at least 119kg / cm2, and an elongation of 100%; Another example of urethane that can be used is presented in US Pat. No. 5,112,282 issued to Patterson and Asoc. A urethane having high temperature properties is presented in WO 96/0284 (February 1, 1996), issued to Wu and Asoc Whatever the urethane that is chosen, it must have the property that the liquid state during the casting is able to flow and penetrate the interstices of the rope as will be explained later in greater detail. A plurality of transversely oriented slots 20 may optionally be formed in an outer layer of the band. Although not necessarily, the slots 20, reduce the weight of the band and improve somewhat the flexibility of the band. These spaced teeth 14, formed from the body, can have any desired transverse shape such as trapezoid, curvilinear, or truncated curvilinear. Examples of curvilinear tooth shapes are presented in U.S. Patent Nos. 3,756,091 to Miller; 4,515,577 to Cathey, and asoc .; and 4,605,389 to Westhoff, the cured urethane has a high coefficient of friction (for example about 0.65), with most of the web materials of the same pulley. Consequently, it is necessary to reduce the coefficient of friction so that it is not aggressive (for example down to about 0.45 along the teeth of the band), so that the teeth of the band can easily enter and exit the slots of a band. pulley. The wear-resistant fabric 16 disposed on the peripheral surface of the teeth of the bandano only offers resistance to wear, but also increases the resistance to breakage of the teeth and reduces the aggressiveness of the teeth of the band when entering the grooves or notches of the pulley. Preferably, the fabric has a low coefficient of friction such as that presented in US Patent 3, 964,328 issued to Redmond. The fabric must also have some extensibility to accommodate the deflection of the teeth when the band is in use. The creased nylon fabric 15 has proved to be satisfactory for the tear-resistant fabric. The tension member 18 in the form of a rope has a helical spiral across the width of the band in a spaced apart manner. The rope preferably occupies approximately 56 to 80% of the width of the band and more preferably approximately 64 to 81% of the width of the band. It is necessary that the rope is embedded in and basically surrounded by the urethane of the body, so that the rope meets the urethane body. The rope comprising the tension member is made of carbon fibers and an example of this is the carbon fiber sold by Amoco. The carbon fiber is typically made by carbonizing another fiber such as polyacrylonitrile fiber, wherein the carbonization process basically reduces the diameter of the fiber. The skein of coal is characterized by the number of fibers contained there, rather than by denier or detex. A nomenclature of numbers and the letter "K" are used to indicate the number of carbon fibers in a skein. Of course carbon fiber can be characterized by those terms when desired. For example skein of carbon fiber "3K", the K, is an abbreviation for a thousand fibers, and the 3, indicates a multiplier, thus the skein of carbon 3K, identifies a skein of 3 thousand fibers or filaments. Like other textile materials, a certain number of carbon fibers combine to form a skein; one skein can be combined with another skein to form a larger skein and the skein or skeins of skeins can be twisted together to form a rope. The carbon fiber has an extremely small diameter that can be 6.5 microns, the individual fibers fracture easily when a skein is processed to form a rope. For this reason, it is desirable to keep the number of mechanical processes to a minimum when forming a rope, for example, the twisting together of several skeins to form a bundle of skein and twist the skein bundles around to form a rope, are mechanical operations that fracture the individual fibers. The number of fractures decreases by reducing the number of twisting operations. Fiber manufacturers often coat the fibers with a material that acts to lubricate the fiber and prevent fracture of the fiber when it is processed into skeins and spun on reels, in some cases the coating may have a chemical structure that is compatible with the fiber. an adhesive used to treat a string when included in a power transmission band. Referring to Fig. 2, a 6K-3 string is shown where there are three folds or groups 22, 24, 26, of skein of 6K carbon fiber, twisted together (with a twisting multiplier of 2.1), to form the rope 18, only the skein fold 22, schematically illustrates the ends of the skeins in the fold and in the skein bundles 22, 26, are schematized with phantom lines so that clarity increases when illustrating a feature of the present invention. Urethane in an empty liquid form has carboxyl groups that are polar. During the casting process to form a band, it is important that the urethane liquid wet the string so intensively that the string takes up urethane in the interstices 28, formed between the fiber filaments comprising the string. A water-based epoxy such as that provided by Amoco, has a UC309 finish, which is polar; such polar material is preferred since it allows the epoxy to wet the rope during casting. One way to characterize the ability of carbon fiber to be moistened with urethane is to measure the contact angle of the carbon fiber with deionized water using an instrument that measures the dynamic contact angle since deionized water is also polar. It has been determined that a contact angle of the carbon fiber with the deionized water of less than 60 °, and preferably less than 45 °, will provide the necessary penetration into the interstices of the rope to capture the material of the band when the band is strain or empty The amount of web material that a string captures during casting can be measured by weighing a length of string length and comparing it to a string that is removed from a finished band and measuring the difference in weight. In this way, the rope captures the material of the band in mg x mm3, of the rope volume that can be determined for each millimeter of the length of the rope. There is a minimum amount of penetration to a point 30, (schematically illustrated by a phantom line), where the string captures a sufficient amount of urethane and the band of the invention exhibits improved performance compared to the prior art bands, such as as bands constructed with a tensor member made of aramid fiber. The penetration can be more complete and up to a point 32, (illustrated by a phantom line), whereby the cord captures more band material, and the band exhibits a substantial increase in performance with respect to the above-mentioned prior art bands. . Referring to Fig. 3, a rope made of aramid from a band tension member of the prior art is shown. The rope comprises 5 bundles of skein, 36, 38, 40, 42, 44 where each bundle of skein is first twisted in one direction to form a fold and subsequently the pleats are twisted together in an opposite direction to form a rope 34. Only the fold 36, schematically illustrates ends of individual skeins in a skein fold. The skeins of skein 36-42, are schematized with ghost lines for the sake of clarity. Aramid fiber is fragile in compression but to a lesser degree than carbon fiber. The aramid fiber can be treated with a material in the manufacture of the skein, and later coated with an epoxy that prevents the fiber from fracturing when the skeins are twisted first in the direction and then in the opposite direction to form a rope. The epoxy coating does not completely seal the rope 34, but rather leaves interstices 44, where the liquid urethane can penetrate the rope during the manufacturing process of the band. Care should be taken to prevent penetration into a rope beyond point 48, because too much urethane capture will cause a decrease in belt life. The decrease in the life of the band, can be attributed to what is taught in the technique mentioned above (for example Terhune), where the complete penetration of the interstices of the rope by the urethane, tends to form a solid mass of the rope together with the band, and therefore reduces the elasticity. The bands become more difficult to bend or hard (that is, there is an increase in the modulus of selection or said reduction in the flexibility of the band to bend around the pulleys when the rope is filled with urethane). The bands constructed in accordance with the invention may have a rope construction of any desired type including the types illustrated in Figs. 2 and 3. Such bands are initially rigid to bending compared to similar bands constructed with aramid ropes; as predicted by the prior art, the bands are rigid to flex because the urethane penetrates the interstices of the string to a degree that approximates making a solid mass of the string. Initially, the bands are so rigid that a break is often heard when the bands are folded manually, the crackling noise is believed to be a result of the individual fibers of the strings when they are being fractured. Also when the belts are operated around the pulleys, there is a remarkably rapid decay of the tensile strength in the belt (for example a decrease of 27 to 40% in 500 hours), which gives the indication that the belts would be inadequate for the service. Bands of the prior art with aramid rope have less decay in tensile strength ranging from 50 to 53% in 500 hours. In short, the noise and the tense decay lead him to believe (and as it is based on the prior art), that such bands would be unsatisfactory. On the contrary, the bands of the invention prove to be a significant improvement over the bands of the prior art of similar construction, where the only difference is the material of the rope and the treatment of the rope. To characterize the qualities of the invention, bands with a separation of 8 and 14mm were built and tested; the strips constructed in accordance with the present invention included carbon fiber with a cord treatment including that the cord captured various amounts of the band material. The bands of the invention were marked with respect to similarly constructed bands except the rope was made of aramid, and the aramid rope captured different amounts of the material of the band. The band thus constructed had thus constructions in accordance with what is shown in table 1. Table 1 String Bandwidth 8mm 14mm Carbon fiber caliber, mm 1.7 (.042pul.) 1.98 (.078pul.) Denier 10,800 32,400 construction 6K -3 6K-9 (18,000 fibers) (54,000 fibers)
Aramid caliper, mm 1.16 (.046in) 2.29 (.090in) denier 8.640 32.700 construction 4 x 2160 5 x 6540
The bands thus constructed were tested and compared to each other. The power test included running 8mm bands, with 17.2 to 25.8 horsepower on 24 grooved pulleys at 200 rpm. up to the failure of the band and bands of 14 mm, on 32 pulleys of slots with a power of 60 to 92.3 horsepower at 1,750 rpm, until the failure of the band. Referring to Fig. 4, the 8 mm bands with aramid rope and having a urethane capture of 0.02 mg / mm3, reached a maximum band life of approximately 400 hours, and a decrease in performance to a life of band of approximately 160 hours when the urethane capture was increased to 0.26mg / mm3, similarly the 14mm aramid rope bands, worked well for approximately 400 hours of band life until the urethane capture exceeded 0.26mg / mm3, where the life of the band began to fall at approximately 380 hours. In contrast to the aramid rope bands, both the 8 and 14 mm bands, constructed with a carbon fiber rope and in accordance with the present invention, presented an unexpected improvement in performance in terms of life of band of approximately 480hrs. When the interstices of the rope of the band captured a minimum of approximately 0.20mg, of band material per cubic millimeter of rope volume for each millimeter of the length of the rope. There was also a more important improvement in the performance of the band with band lives of approximately 800hrs. , when the carbon cord captured a minimum of approximately 0.24mg / mm3. When the urethane capture increased to 0.28mg / mm3, the performance of the band increased approximately 1900 hrs. A penetration of the rope with the rope material was achieved when the carbon fibers formed a contact angle with the deionized water of about 60 degrees or less. The bands that had a 3/8 pitch, and a construction with 6K-2 carbon fiber rope (12,000 fibers), were also built.