Patent Application
20100031535
The present invention relates to a sole for an article of footwear. More particularly, various examples of the invention relate to applying graphic elements to a sole element for an article of footwear.
Applying brand information, colors, decorations, etc. to the soles of shoes is desirable. A variety of techniques for creating such decorated soles have been developed.
It is known, for example, to apply a color toning additive to a vulcanized rubber plate and to subsequently apply heat and pressure via an embossing roller to the coated rubber plate, thereby forming a marked plate which can be die-cut, sewn, glued, etc. to form a sole for a shoe.
It is also known to incorporate a thin layer or skin having a decorative pattern into a base layer or substrate. In some examples, a layer of decorative fabric is incorporated into an injection-molded or compression-molded sole. In another example, a polymeric membrane having a decorative pattern printed thereon is placed within a mold cavity and subsequently co-molded to a poured substrate.
U.S. Pat. No. 7,188,648 issued to Mellet et al., which is incorporated herein in its entirety by reference, discloses a partially cured skin, with a decorative printed pattern facing the ultimate outer surface. This skin, which has a thickness of from 0.5 mm to 1 mm, is co-molded to a partially-cured substrate to form a decorated laminated tire tread. Difficulties may occur when trying to align two substrates within a single mold. Problems may also arise with the quality of the bond between the two substrates, particularly with respect to air that may be trapped between the layers during the bonding process. Further, the thinness of the skin layer may cause handling problems and require special care during the co-molding process to prevent undesirable perforation or tearing of the skin.
Thus, all of these known techniques have drawbacks. Some involve multi-step processes, thereby increasing production costs and time. Others require special handling techniques to protect and/or properly align the decorative pattern during production. Even others require multi-layer construction, thereby increasing the complexity of the process and the chances of introducing flaws into the finished product.
Accordingly, it would be desirable to provide decorated soles for footwear that are easy to produce with a minimum of handling and with a robust and efficient process.
Various aspects of the invention relate to a decorated sole element for footwear. Some aspects of the invention relate to footwear having such a decorated sole element.
According to one aspect of the invention, a method of forming a sole element for an article of footwear includes obtaining a partially-cured substrate having a first surface and an opposed surface opposite the first surface and applying one or more graphic elements to the first surface to create a decorated substrate. The method further includes placing the decorated partially-cured substrate into a mold for a sole element and curing the decorated substrate (e.g., while applying heat and/or pressure). During curing, at least a portion of each of the first surface and the opposed surface contacts the mold.
According to another aspect of the invention, a method of forming a sole element for an article of footwear includes obtaining a partially-cured substrate and applying one or more graphic elements to one or more surfaces of the substrate to create a decorated substrate. The method further includes placing the decorated substrate into a mold for a sole element and curing the decorated substrate within the mold (e.g., while applying heat and/or pressure). The decorated substrate substantially fills the mold.
The graphic elements could include an ink component, a reflective component, an anti-abrasive component and a textured component.
The substrate may have a thickness greater than 0.1 cm, and optionally may have a thickness greater than approximately 0.15 cm, greater than approximately 0.2 cm, greater than approximately 0.3 cm or greater than approximately 0.4 cm. The thickness may depend, at least in part, on the required thickness of the sole element. The thickness may also depend, at least in part, on the desire to minimize distortion of the graphic element.
The substrate may be a composite rubber mixture. Further, the substrate may contain a filler, for example, carbon, graphite, glass and/or aramid fibers.
According to another aspect of the invention, a partially-cured ground-contacting element may be co-cured to the first surface of the substrate during the step of curing.
According to even another aspect of the invention, the substrate may be a pre-form having at least one relief feature. The relief feature is configured to accommodate a change in geometry of the pre-form from a substantially flat pre-form to a sole element having three-dimensional characteristics. An example of a relief feature is a notch.
The sole element may be an outsole, a midsole or any other portion of a sole structure.
According to another aspect of the invention, an article of footwear includes the sole element formed by one of the disclosed methods and an upper configured to retain the sole element to a user's foot.
The foregoing Summary, as well as the following Detailed Description, will be better understood when read in conjunction with the accompanying drawings.
The following discussion and accompanying figures disclose a decorated sole and an article of footwear having a decorated sole in accordance with various aspects of the present invention. Although concepts related to the sole are disclosed with reference to an article of athletic footwear, the sole is not limited to use with footwear designed for athletic activities. Thus, the sole according to various embodiments of the invention may be incorporated into footwear that is generally considered to be non-athletic, including a variety of dress shoes, casual shoes, sandals, and boots.
An article of footwear 100 is depicted in
Sole structure 20 may include more than one sole element 22. Thus, as illustrated in
These sole elements may be formed from any suitable material. Thus, as known in the art, sole element may 22 be formed of polymer foam material, such as polyurethane or ethylvinylacetate. This may be particularly suitable for midsole 26. Sole element 22 may be formed of a wear-resistant material, such as natural or synthetic rubber or a combination thereof. This may be particularly suitable for outsole 24. One particular composite rubber mixture may include approximately 75% natural rubber and 25% synthetic rubber. The synthetic rubber could include a styrene-butadiene rubber. Other suitable polymeric materials for outsole 24 include silicone, thermoplastic polyurethane, polypropylene, polyethylene, ethylvinylacetate, and styrene ethylbutylene styrene. The material of sole elements 22 may also include fillers or other components to tailor their wear, durability, abrasion-resistance, compressibility, stiffness and/or strength properties. Thus, for example, outsole 24 may include reinforcing fibers, such as carbon fibers, glass fibers, graphite fibers, aramid fibers, basalt fibers, etc.
Various other secondary elements 21, i.e., comfort elements, motion-control elements, stability elements, ground-contacting elements, etc., may be incorporated into sole structure 20. For example, a sockliner 27 may be located on an upper surface of midsole 26 to provide a comfortable surface for contacting the foot. As a second example, a comfort element could be a fluid-filled bladder (not shown) and such bladder may be incorporated into midsole 26 or located between midsole 26 and outsole 24. By way of another example, stability elements could include anti-roll stiffeners, orthotics, pronation control elements, and the like incorporated or otherwise attached to sole structure 20. As an example of ground-contacting elements, cleats or treads may be incorporated or otherwise attached to outsole 24.
In accordance with an aspect of the invention and referring to
As shown in
In one embodiment, referring back to
As best shown in
Substrate 40 is partially cured. As an example, the 75/25 rubber composite hybrid substrate may be cured for approximately 300 to 350 seconds at a temperature of approximately 350° C. under a pressure of approximately 2000 pounds/square inch, thereby achieving a substantially half-cured rubber product. Other partial cure times, temperatures and pressures for a variety of different materials would be apparent to and determined by persons of ordinary skill in the art, given the benefit of this disclosure.
Substrate 40 may have a thickness, t, which is suitable for substantially filling the mold and/or for forming a complete sole element 22. The optimum thickness of substrate 40 may be selected based on the material properties of the substrate and the desired finished properties of the sole element 22. For example, light-weight running shoes require a lighter weigh sole that standard running shoes, while standard hiking boots require a heavier duty sole than running shoes. In one embodiment, the thickness of substrate 40 may be greater than 0.1 cm for ease of handling the substrate. Optionally, the thickness of substrate 40 may be greater than approximately 0.15 or 0.2 cm in order to provide, for example, sufficient material to easily handle the finished sole element 22. As another option, the thickness of substrate 40 may be greater than approximately 0.3 cm in order to provide sufficient material to create, for example, a more durable outsole 24 or to provide sufficient material for forming treads or other ground contacting elements. As even another option, the thickness of substrate 40 may be greater than approximately 0.4 cm or even up to approximately 0.5 cm in order to provide, for example, sufficient material to form even more rugged outsoles or to form deeper ground contacting elements.
Further, substrate 40 may be provided with a thickness for optimizing the quality of the finished graphic elements. In general, increasing the thickness of substrate 40 results in less deformation of the substrate during application of the graphics and therefore less deformation or distortion of the graphic elements. Thus, a thickness of substrate 40 approximately 0.1 to approximately 0.15 may provide sufficient stability to allow for a minimally distorted graphic element. Increasing the thickness of substrate 40 above approximately 0.10 or above approximately 0.2 cm would result in even less distortion of the graphic elements. Providing a substrate above approximately 0.3 cm provides even better image stability, while providing a substrate having a thickness above approximately 0.4 cm results in significantly less deformation than a substrate having a thickness less than 0.1 cm.
As noted above, and as best shown in
One suitable ink product that may be used in accordance with at least some examples of this invention is produced by Union Process, Inc. of Akron, Ohio. Union Process's silkscreen ink (800 series) is a highly viscous ink for use in a silk screening method for decorating rubber latex objects. These silk screen inks are typically concentrated and may be diluted, according to the manufacturer's instructions, with a mineral spirit solvent in the range of 30% solvent to 70% ink by volume. In one aspect of the present invention, the concentrated silk screen ink may be diluted with mineral spirit solvent in the range from approximately 5% to approximately 25% by volume, more preferably in the range of from approximately 10% to approximately 20% by volume, thereby producing an ink with a relatively high solids content. These high solids content inks have a relatively high viscosity and may provide better coverage. This may result in achieving a given opacity of the graphic element in fewer passes or applications of the ink. In one particular aspect, the concentrated silk screen ink is diluted with approximately 10% by volume of mineral spirit solvent. The solvent can be a fast drying solvent. After application, the ink may be air dried for 3 to 5 minutes. Optionally, a dryer may be used to dry the ink after application. A suitable mesh for applying these 800 series inks ranges from 200-325 mesh.
Alternatively, graphic elements 50 may be applied to substrate 40 as decals transferred from a carrier film. Such decals may include ink decals, rubber decals or other polymeric or non-polymeric materials. Other methods of applying graphic elements 50 to the surface of the substrate 40 would be apparent to persons of skill in the art, given the benefit of this disclosure.
Graphic elements 50 may be used to apply logos, brand names, manufacturing or source indicia, style identification, size, etc. Graphic elements may be used to apply colored patterns, including mono-colored or multi-colored patterns. Graphic elements may include reflective, phosphorescent, anti-abrasion, textured, etc. components.
In one embodiment, graphic elements 50 may be applied to both sides of substrate 40, such that decorated substrate 44 includes graphic elements 50 on opposing surfaces. This may be particularly suitable, for example, when the article of footwear is a flip-flop or sandal or other article of footwear wherein both the upper and lower surfaces of the sole element 20 are visible.
In another embodiment, the material of substrate 40 may be provided with a colorant. The material of the substrate may be provided with a colorant that completely permeates the substrate. In one aspect, the color of the substrate material may be coordinated with the applied graphic elements 50. Thus, by way of non-limiting example, substrate 40 may be formed of a rubber-like material having an integral color that complements the colors of the graphic elements. Optionally, the color of the material of the substrate may be of the same family as the base color (or as an accent color) of the graphic elements. By coordinating the color of the material of the substrate with the colors of the graphic elements, less ink may need to be applied to achieve the final desired graphic element colors. For example, the material of the substrate may be a dark blue and the color of the graphic elements may be light and/or medium blues. In certain aspects, the color of the material of the substrate may be coordinated with the graphics elements such that openings in the graphic elements, which allow the color of the substrate to be exposed, may be part of the overall design of the ultimate sole element. In other aspects, the color of the material of the substrate may be chosen to provide very little contrast between the substrate and the graphic elements. This may be desired if the graphic elements were to wear away, thereby exposing the underlying substrate.
According to another aspect of the invention, and referring back to
Additionally, a second, partially-cured substrate may be placed within mold 60 with the first, decorated substrate 40. The first and second substrates may be co-cured together. The first and second substrates may be formed of the same or different materials. They may have the same or different dimensions. The second substrate may or may not be decorated.
In another embodiment, as shown in
As best shown in
Alternatively, as best shown in
As best shown in
Referring to
In one embodiment, substrate 40 or pre-form 42 may include one or more relief features 45. Relief feature 45 is meant to allow the substantially flat substrate to more easily conform to the three-dimensional aspects of the mold. Thus, for example, as shown in
Referring to
While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art, given the benefit of this disclosure, will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth above. All examples, whether preceded by “for example,” “such as,” “including, or other itemizing terms or followed by “etc.,” are meant to be non-limiting examples, unless otherwise stated or obvious from the context of the specification.
