The present invention relates generally to tire enhancement and, more particularly, to a tire having a reinforcing exo-belt cover or skin, having a relatively high percentage by weight of a reinforcing material covering an entire outer surface of a base tire, wherein the base tire generally does not include or includes a low percentage by weight of a reinforcing material therein. Tires typically include a uniform distribution of reinforcing material throughout with respect to the outer surface of the tire including the treads and the remaining portions of the base tire. It would be advantageous to construct a tire having a concentration of reinforcing material at its outer surface, including on the treads and at the root of the treads where the tire is subjected to high stresses and impact loads.
Briefly stated, in a preferred embodiment, the present invention is directed to a tire for mounting to a transport vehicle including a base tire and a skin. The skin includes a predetermined pattern mounted thereon that is positioned on an external peripheral surface of the skin. The base tire and the skin are constructed of a predetermined rubber composition. The skin includes at least about nine percent (9%) by weight of reinforcing fibers and the base tire includes less than about three percent (3%) by weight of reinforcing fibers.
In another aspect, the prevent invention is directed to a tire for mounting to a transportation vehicle including a base tire constructed of a first rubber mixture and a skin constructed of a second rubber mixture. The first rubber mixture includes about less than three percent (3%) by weight reinforcing fibers and the second rubber mixture includes about nine percent (9%) or more reinforcing fibers by weight. The skin is mounted to and covers an entire outer circumferential surface of the base tire.
In a further aspect, the present invention is direct to a tire assembly for insertion into a mold for construction of a tire. The tire assembly includes a partially cured base tire, an adhesive membrane inhibitor and a partially cured skin. The adhesive membrane inhibitor is positioned on an outer circumferential surface of the partially cured base tire and the partially cured skin is positioned on the adhesive membrane inhibitor. The partially cured skin includes a predetermined pattern printed thereon. The predetermined pattern is positioned on an external peripheral surface of the skin. The adhesive membrane inhibitor generally prevents migration of contaminating materials between the base tire and skin during curing.
The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, “left”, “lower” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the bicycle tire and designated parts thereof. The terminology includes the above-listed words, derivatives thereof and words of similar import.
Referring to the drawings in detail, wherein like numerals indicate like elements throughout, there is shown in
The present invention relates to a base tire or tire 2 having an exo-belt skin or skin 1 that is applied to the external surface of the base tire 2, as is described more fully herein below. The preferred base tire 2 is shown in
As best shown in
In addition, in the case of some bicycle tires, reinforcing fibers may be added to the rubber mixture to improve performance. Typically, when such reinforcing fibers are added to the mixture, the mixture is referred to as a “3D compound”. The reinforcing fibers may comprise any suitable fiber or alternative reinforcing material, preferably mono-filament fiber, such as Kevlar®, which may be crushed and mixed into the rubber mixture. Kevlar® is an aromatic polyamide or aramid mono-filament fiber, as is know by one having ordinary skill in the art. Typically, such three dimensional (3D) compounds include approximately three percent (3%) by weight of the reinforcing fibers. However, the percentage of reinforcing fibers in the three dimensional (3D) compound may be less than or greater than three percent (3%) for particular applications.
As shown in
The skin 1 of the preferred embodiments preferably has a width that encompasses the entire width of the tread pattern 30 and each side wall 8 of the base tire 2 extending from one bead 9 to the other bead 9. That is, it is preferred that the entire exposed outer circumferential surface 6 of the base tire 2 is entirely covered by the skin 1. It is contemplated, however, that the width of the skin 1 may be less than that of the base tire 2 of the preferred embodiment. For example, the skin 1 could be configured to overlie and cover at least a portion of only one of the side walls 8 of the base tire 2 or just the tread members 10. Alternatively, the skin 1 may be configured to cover the entire outer circumferential surface 6 of the base tire 2 except for the tread members 10, such that the tread members 10 retain their natural ornamental appearance. Again, the width of the skin 1 will depend on the visual and performance characteristics one having ordinary skill in the art desires to impart to the tire. Since one of the functions of the skin 1 is decorative, the width of the skin 1 and the portions of the base tire 2 on which the skin 1 is applied will be determined by the visual effect to be created. The decorative function of the skin 1 is discussed in greater detail below.
Additional factors to be considered in determining the length and width of the skin 1 are the added weight and cost of the skin 1, among other factors. Inasmuch as rotational weight, particularly at the outer circumference of the tire, dramatically increases the amount of work required to increase the rotational speed of the tire, minimizing the rotational weight is important to overall tire performance. Accordingly, it is preferred that the skin 1 is tailored to balance between the added tire weight and the aesthetic and performance purposes and visual effect sought to be achieved. Whereas in the preferred embodiments, the skin 1 is intended to enhance the aesthetic characteristics of the tire around the entire outer periphery of the base tire 2, one may desire that the visual aesthetic characteristics are more locally limited on the outer circumferential surface 6 and/or tread members 10 of the tire.
As best shown in
Preferably, the skin 1 which, before being applied to the base tire 2 is in a green or partially cured state, is made of a composite rubber mixture, preferably a blend of about twenty-five percent (25%) synthetic rubber, such as styrene-butadiene rubber and about seventy-five percent (75%) natural rubber. The composition of the skin 1 is preferably the same as or similar to the composition of the base tire 2 to which the skin 1 is applied. In this manner, bonding between the skin 1 and the base tire 2 is enhanced. Additionally, a combination of rubber and a polymeric material could be used. Other materials known to those skilled in the art could also be used to construct the skin 1 and/or base tire 2, if desired.
In the preferred embodiments, a relatively high percentage of reinforcing fibers are added to the skin 1 to enhance performance and no or a relatively small percentage of reinforcing fibers are added to the base tire 2. Preferably, the reinforcing fibers are of the aromatic polyamide mono-filament type, such as Kevlar® and are crushed and mixed into the rubber mixture. However, the reinforcing fibers are not limited to the aromatic polyamide mono-filament type and may be constructed of nearly any type of reinforcing material, such as fiberglass, carbon, steel or other like materials that provide desired reinforcing properties to the tire. The reinforcing fibers, preferably the aromatic polyamide mono-filament fibers, could comprise between one and twelve percent (1-12%) by weight of the rubber mixture of the base tire 2 and skin 1, however, the reinforcing fibers of the preferred embodiments preferably comprise about six to twelve percent (6-12%) of the mixture of the skin 1 and zero to three percent (0-3%) of the mixture of the base tire 2. The reinforcing material selected preferably provides both durability and light weight to the skin 1 and is such formulated that the skin 1 bonds to the base tire 2 during production. Preferably the skin 1 is limited in thickness to permit effective transfer and retention of the desired decorative pattern 16 or image onto the desired portion of the outer circumferential surface 6 of the base tire 2 and to provide the desired performance characteristics. However, it is also contemplated that the skin 1 may be constructed having a substantial thickness so as to provide a thick protection layer for the base tire 2 from wear and abrasions.
In the preferred embodiments, the aromatic polyamide reinforcing fibers make up approximately nine percent (9%) by weight of the skin 1 and the reinforcing fibers make up approximately three percent (3%) by weight of the base tire 2. Concentrating the reinforcing fibers in the skin 1 improves puncture resistance of the tire, provides stability to the treads 10 and permits the tire to contain a greater tire pressure therein during use when compared to a typical tire having identically formulated base and skin formulations and concentrations of reinforcing fibers.
Tires are typically subjected to their most extreme stresses and impacts at their outermost surfaces due to the highest hoop stresses occurring at the outer surface, the puncture forces being applied to the outer surface during use and typically the highest bending and shear forces being applied at the bases of the treads 10. Accordingly, the ability to provide additional stiffness, strength and/or puncture resistance to the outermost surface of the tire by increasing the percentage by weight of the reinforcing fibers in the skin 1 is desirable because such an application positions the fibers where they are needed most to react the high stresses in these areas. In addition, the ability to concentrate the reinforcing fibers in the outermost surfaces in the skin 1, where they can be utilized to react the high stresses while reducing the percentage by weight of the reinforcing fibers in the base tire 2, generally reduces costs for the relatively expensive reinforcing fibers because the base tire 2 typically comprises a larger overall volume of the tire, thereby reducing the amount of reinforcing fibers required for each tire. Accordingly, concentration of the reinforcing fibers in the skin 1 improves the performance and durability of the tire while reducing the overall costs associated with producing the tire.
Concentration of the reinforcing fibers in the skin 1 of the tire may also improve the ability of the tire to adhere or stick to the road or other surface that the tire is rolling on in use. Specifically, an outer, top surface 10a of the treads 10 is the surface of the tire that is directly in contact with the road surface or other supporting surface during use and is subjected to the greatest amount of wear. In addition, the inclusion of the reinforcing fibers in the rubber mixture of the base tire 2 and the skin 1 tends to decrease the stickyness of the material. That is, the skin 1, having a high percentage by weight of reinforcing fibers, tends to have a lower stickyness to the road surface when compared to the lower percentage of reinforcing fibers by weight base tire 2 that is comprised of only rubber with no reinforcing fibers therein. When the top surface 10a of the treads 10 wears such that the base tire 2 is exposed at the top of the individual treads 10 or, if desired by the user, the skin 1 at the top surface 10a is shaved to expose the base tire 2, the tires typically have a stronger adherence or stickyness to the road surface, which may be desirable for users in some applications. Such a tire construction provides the desired high strength at an outer surface of the tire and particularly at a root edge 10b of the treads 10 by concentrating the high reinforcing fiber percentage skin 1 the areas of the tire that are subjected to the highest stresses and loads. In addition, such a tire construction provides a relatively high stickyness at the surfaces of the tire that are contacting the road surface by exposing the sticky base tire 2 material to the road surface, either through wear of the tops of the treads 10 to expose the base tire 2 or by shaving of the tops of the treads 10. Accordingly, such a tire would typically have the ability to withstand relatively high tire pressures, high stresses in the skin 1, high stresses at the root edge 10b of the treads 10 and high puncture and wear resistance through inclusion of the high percentage or reinforcing fibers in the skin 1 and provide a highly sticky tire by exposing the relatively low or no percentage of reinforcing fibers base tire 2 to the road surface.
In some applications, at least the exposed outer surface of the skin 1 could be coated with a protective coating (not shown) to protect the skin 1 from the effects of wear and abrasion both following manufacture (in transport, etc.) and during use. Preferably the protective coating is urethane, but it is contemplated that the protective coating could be any transparent or translucent, durable, flexible material with sufficient bonding characteristics to adhere to the skin 1 under the conditions of anticipated use and/or manufacturing. Preferably, the protective coating selected also provides protection to the skin 1 from ultraviolet light and the like. The protective coating preferably works together with the high reinforcing fiber percentage skin 1 to enhance wear resistance at the surface of the tire. The protective coating may not be applied to the top surfaces of the treads 10 such that the relatively sticky, low reinforcing fiber percentage base tire 2 is in facing engagement with the road surface during use.
As best shown in
The decorative pattern 16 is visible on at least a portion of the peripheral surface of the skin 1, i.e., it is applied to the surface of the skin 1. Preferably, the skin 1 is produced with the intended colored design printed thereon. Alternatively, it is to be understood that the decorative pattern 16 could be embedded within a portion of the skin 1.
The skin 1 may be made by any of several methods well known to those skilled in the art. Most preferably, the skin 1 is made by creating a thin sheet of rubber composition material (not shown) which is partially cured. Preferably, the skin 1 has a thickness in the range of about one-half to about one millimeter (½-1 mm) and more preferably is in the range of one-half to three-quarters of a millimeter (½-¾ mm). Preferably, a membrane (not shown) is applied to one side of the skin 1 to enable the skin 1 to be handled more easily. It should be understood that the use of a membrane for handling is not necessary. The decorative pattern 16 is printed on the skin 1 using any of a number of techniques known to those skilled in the art, but preferably is printed using offset and other known printing techniques which are well-known. Preferably the ink applied to the skin 1 is sufficiently rubberized or flexible to be able to withstand the rigors of tire use, including expansion during inflation and flexure during use, based on the cycle of alternate tension/compressive stresses created on the tire during normal use.
In an alternative embodiment, at least some of the three dimensional tread members 10 are positioned on the outer circumferential surface 6 in a pattern that corresponds in theme or design to the design printed on the skin 1. In a further alternative embodiment, at least some of the tread members 10 are shaped to correspond in theme or design to the design printed on the skin 1. It is contemplated that the tread members 10 may be both shaped and positioned so as to correspond in design or theme to the design printed on the skin 1 and to enhance the overall aesthetic appearance of the tire.
Referring to
The skin 1 is preferably applied to the base tire 2 during the tire manufacturing process. As stated above, the skin 1 is in a partially cured, green state at the time it is constructed. The adhesive membrane inhibitor 40 is preferably positioned between the skin 1 and base tire 2 or is brushed or otherwise applied to the inner surface of the skin 1 or to the outer surface of the base tire 2 prior to positioning the base tire 2 relative to the skin 1. Preferably the skin 1 and inhibitor 40 are applied to the base tire 2 when the base tire 2 is also in a green or partially cured state and the base tire 2, inhibitor 40 and skin 1 are thereafter fully cured (vulcanized) together to form an assembled tire. The adhesive membrane inhibitor 40 tends to improve the adhesion of the base tire 2 to the skin 1 prior to and following a curing cycle. The molding equipment used for curing the base tire 2, inhibitor 40 and skin 1 is conventional equipment used during tire manufacture and is generally well known to those skilled in the art. Other equipment and/or methods may be employed to secure the skin 1 to the base tire 2.
Preferably a BOM vertical mold is used to cure and secure the skin 1, inhibitor 40 and base tire 2 to each other, however, other molds such as a toroidal clam-shell molds or the like could be used, if desired. Preferably, the partially cured skin 1, the inhibitor 40 and the partially cured base tire 2 are placed in the mold and thereafter an expandable interior mold bladder (not shown) is expanded using steam or other such pressure to cause the skin 1, the inhibitor 40 and the base tire 2 to expand into the mold with the outer or exposed surface of the skin 1 facing the inner surface of the mold. Further expansion of the mold bladder causes the skin 1 and base tire 2 to conform to the inner surface of the mold thereby creating the desired tire shape, texture and tread pattern. The adhesive membrane inhibitor 40 generally adheres to both the skin 1 and base tire 2 and improves the bond between the base tire 2 and skin 1. The inhibitor 40 also generally limits or prevents migration of oils, carbon and other contents of the base tire 2 into the skin 1. The bladder is retained in place by the pressure for a predetermined time period during which the tire 1, the inhibitor 40 and the skin 2 are fully cured or vulcanized by heat and pressure transmitted to the bladder via steam or other well known methods. Preferably, the outer surface of the mold is also heated in a manner known to those skilled in the art to enhance curing of the combined skin 1, inhibitor 40 and base tire 2 and to prevent insufficient, inconsistent or over curing of the base tire 2, inhibitor 40 and/or skin 1.
Preferably, the skin 1 is initially positioned in the mold so that upon expansion of the mold bladder, the decorative pattern 16 on the skin 1 is in proper registry with the tread pattern 30 imparted to the skin 1 and the base tire 2 by the inner surface of the mold. It will be recognized by those skilled in the art that the skin 1, through the curing process, becomes fused or bonded to the base tire 2 due to the combination of the skin 1, the inhibitor 40 and the base tire 2 and the final curing process. Thus, when the partially cured base tire 2 and the partially cured skin 1 are subjected to the remainder of the curing process to which a tire is normally subjected and which is well known to those skilled in the art, the skin 1 bonds with or becomes part of the base tire 2 with the inhibitor 40 positioned therebetween and generally creating a barrier to migration of undesirable materials between the skin 1 and the base tire 2 and improving the bond. The bonding of the base tire 2 and the skin 1 is enhanced due to the rubber composition of the skin 1 being generally the same as or similar to the rubber composition of the base tire 2. It is also preferred that the skin 1 is applied prior to filly curing the base tire 2 to help avoid a costly double-cure process and to create a permanent bond between the skin 1 and the base tire 2 so that the visual characteristics of the tire remain aligned with or in registry with the base tire 2 in both the circumferential and axial directions. It should be understood, however, that for some applications, the skin 1 may be applied to the base tire 2 after the base tire 2 is fully cured using an adhesive, for example, the inhibitor 40, or some other direct or intermediate bonding agent or process. Specifically, the adhesive membrane inhibitor 40 may be applied to the base tire 2 after it is fully cured and then the skin 1 may be applied over the adhesive membrane inhibitor 40 for full curing of the skin and inhibitor 40 to the base tire 2.
As shown in
It is noted that the preferred skin 1 covers the tread members 10 in their entirety, as contrasted to prior techniques for decorating tires, such as that disclosed in U.S. Pat. No. 5,904,794, which is incorporated herein in its entirety by reference. Covering the entire visual surface of the tire with the decorative pattern 16 or the surface texture 20 is advantageous not only for improving the aesthetics of the tire, but also to permit the design to incorporate the tread members 10 into the overall visual appearance of the tire or of the vehicle that the tire is mounted on. Additionally, covering the tread members 10 with the skin 1 can cause the skin 1 to serve as a reinforcing exo-belt which also improves the performance and wear resistance of the tire, particularly if the reinforcing fibers and more particularly is the above-described high percentage by weight of reinforcing fibers have utilized in the formulation of the skin 1. The high percentage by weight of reinforcing fibers in the skin 1 may be particularly effective in reducing shearing and bending failures of the tread members 10 at their root ends. In the preferred embodiments, the percentage by weight of the reinforcing fibers in the skin 1 is relatively high when compared to the reinforcing fibers in the base tire 2 and the reinforced exo-belt formed by the skin 1 improves the performance, puncture resistance and wear resistance of the tire, while also generally reducing material costs in the construction of the tire, because the overall percentage by weight of the generally high cost reinforcing fibers is reduced by concentrating the reinforcing fibers where they are most required, in the peripheral or skin surfaces of the tire, while employing little or no reinforcing fibers in the base tire 2.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concepts thereof. It should also be understood that the above disclosure is directed generally to a bicycle tire for purposes of providing one example of the types of tires or rubber-type components to which the present invention may be applied. It is contemplated that the present invention may be applied to any type of tire or other rubber or polymeric component, including, but not limited to, all types of bicycle tires including sew-ups, tubeless and clincher tires, in addition to motorcycle tires, automobile tires, heavy equipment tires, etc. and bath mats, car floor mats, rubberized flooring, rubber hoses, golf club grips, conveyor belts, sneaker soles, etc. The application of the constructions and methods for the tire of the present invention may be particularly adaptable for automobile racing tires or public transportation vehicles by adapting the particular properties of the tires to user requirements and for the ability to apply advertisements on the tires utilizing the decorative patterns. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications within the spirit and scope of the invention, as defined by the appended claims.
This patent application is a continuation-in-part of U.S. patent application Ser. No. 11/470,064, filed Sep. 5, 2006, which is a continuation of U.S. patent application Ser. No. 10/253,837, now U.S. Pat. No. 7,118,643, filed Sep. 24, 2002, which claims the benefit of U.S. Provisional Patent Application No. 60/325,523, filed Sep. 28, 2001, the entire subject matters of which are hereby incorporated by reference.
Number | Date | Country | |
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60325523 | Sep 2001 | US |
Number | Date | Country | |
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Parent | 10253837 | Sep 2002 | US |
Child | 11680212 | Feb 2007 | US |
Number | Date | Country | |
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Parent | 11470064 | Sep 2006 | US |
Child | 11680212 | Feb 2007 | US |