TECHNICAL FIELD

[0001] Embodiments of the subject matter described herein relate generally to shoes and shoe manufacturing techniques. More particularly, embodiments of the subject matter relate to a two-part, dual-density, molded shoe and related manufacturing techniques.

BACKGROUND

[0002] The prior art is replete with a wide variety of shoe designs and different shoe manufacturing processes. One-piece injection-molded shoes have become popular due to their affordable nature, comfort, and lack of shoestrings. For example, many shoes are now produced from injection-molded ethylene vinyl acetate (EVA) material. Such EVA shoes are manufactured by injecting the EVA material into appropriately shaped molds. Most EVA shoes are created from a single material. In other words, the same EVA material is injected into a single mold to create the entire shoe. It may be possible to fabricate an EVA shoe from two or more EVA materials by injecting the different materials into a single mold. However, it may be difficult to control the injection- molding process when more than one material is introduced into a single mold.

Moreover, undesirable blending of the different materials may occur, leading to imperfections, defects, and a higher scrap rate.

[0003] Accordingly, it is desirable to have an improved injection-molded shoe design and a related manufacturing technique. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

BRIEF SUMMARY

[0004] An exemplary embodiment of a two-part shoe is presented here. The two-part shoe includes an injection-molded sole component having a bottom surface and an upper surface, and an injection-molded upper shell component having an upper and a base integrated with, contiguous to, and continuous with the upper. The base has an outer surface affixed to the upper surface of the sole component. [0005] Another exemplary embodiment of a two-part shoe is also provided. The two- part shoe includes a sole component having a bottom surface and an upper surface, where the sole component is composed of a material having a first density. The two-part shoe also includes an upper shell component having an upper and a base integrated with, contiguous to, and continuous with the upper. The base has an outer surface adhered to the upper surface of the sole component in the absence of stitching and fasteners. The upper shell component is composed of a material having a second density that is lower than the first density.

[0006] Also provided is an exemplary embodiment of a method of manufacturing a two-part shoe. The method fabricates a molded sole component from a first material having a first density, the sole component having a bottom surface and an upper surface. The method also fabricates a molded upper shell component from a second material having a second density that is lower than the first density, where the upper shell component has an upper and a base integrated with, contiguous to, and continuous with the upper, and the base has an outer surface. The method continues by affixing the outer surface of the base to the upper surface of the sole component.

[0007] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures.

[0009] FIG. 1 is a perspective view of an exemplary embodiment of a shoe;

[0010] FIG. 2 is a perspective view of the shoe depicted in FIG. 1 at an intermediate stage in the manufacturing process;

[0011] FIG. 3 is an exploded perspective view that shows the two primary

components of the shoe depicted in FIG. 1;

[0012] FIG. 4 is a bottom perspective view of the sole component of the shoe depicted in FIG. 1; [0013] FIG. 5 is a top view of the upper shell component of the shoe depicted in FIG. i;

[0014] FIG. 6 is a bottom view of the upper shell component of the shoe depicted in FIG. l; and

[0015] FIG. 7 is a partially phantom side view of the shoe depicted in FIG. 1 during a step in an exemplary manufacturing process.

DETAILED DESCRIPTION

[0016] The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

[0017] In addition, certain terminology may also be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as "upper", "lower", "above", and "below" refer to directions in the drawings to which reference is made. Terms such as "front", "back", "rear", "side", "outboard", and "inboard" describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms "first", "second", and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.

[0018] The subject matter presented here relates to a two-part shoe construction that includes two primary injection-molded components, namely, a sole component and an upper shell component. The two primary components are individually fabricated using different molds and, after molding, they are assembled together using, for example, an adhesive. In certain preferred embodiments, the two components are molded from an ethylene vinyl acetate (EVA) material. The sole component may be injection-molded from an EVA material that has a higher density and/or a higher resiliency than the EVA material used for the upper shell component. The two-part and dual-density

manufacturing approach described here is easy to implement and facilitates the use of a variety of different materials and colors for a single shoe style or model. Moreover, the two-part technique with separate molds enables a manufacturer to "mix and match" sole components and upper shell components if so desired to create customized and new shoe styles or models that are based on older designs.

[0019] FIG. 1 is a perspective view of an exemplary embodiment of a shoe 100 that has been manufactured in accordance with a two-part technique, FIG. 2 is a perspective view of the shoe 100 at an intermediate stage in the manufacturing process, and FIG. 3 is an exploded perspective view that shows the two primary components of the shoe 100. It should be appreciated that the style and overall design of the shoe 100 reflect merely one of many possible embodiments, and that the style and design of the shoe 100 depicted in FIG. 1 are not intended to limit or otherwise restrict the scope or application of the subject matter presented here.

[0020] The illustrated embodiment of the shoe 100 is based upon two primary components: a sole component 102 and an upper shell component 104 that is affixed to the sole component 102. FIG. 1 depicts the shoe 100 in its final assembled state, after the installation of shoelace retaining elements 106 onto the upper shell component 104 and after placement of a liner 108 into the interior of the upper shell component 104.

[0021] FIG. 3 shows the upper surface 110 of the sole component 102, and FIG. 4 is a bottom perspective view of the sole component 102. FIG. 4 depicts the bottom surface 112 of the sole component 102, which is on the opposite side of the sole component 102 relative to the upper surface 110. The sole component 102 generally includes an outsole 114 and a midsole 116. The outsole 114 and the midsole 116 are integrated, contiguous to each other, and continuous with each other. In other words, the outsole 114 and the midsole 116 are unitary and seamless in this particular embodiment. Indeed, as described in more detail below, the outsole 114 and midsole 116 can be molded together in one piece. Notably, the bottom surface 112 of the sole component 102 corresponds to the outsole 114, as shown in FIG. 4. In practice, the bottom surface 112 of the sole component 102 and/or the outsole 114 may define a sole pattern or sole design for the shoe 100, as is well understood.

[0022] FIG. 5 is a top view of the upper shell component 104, and FIG. 6 is a bottom view of the upper shell component 104. The upper shell component 104 generally includes an upper 118 and a base 120. The upper 118 and the base 120 are integrated, contiguous to each other, and continuous with each other. In other words, the upper 118 and the base 120 are unitary and seamless in this particular embodiment. Indeed, as described in more detail below, the upper 118 and the base 120 can be molded together as a single piece. In this regard, the base 120 may form a solid bottom enclosure for the upper shell component 104, as shown in FIG. 6. In some embodiments, the interior surface of the base 120 defines the footbed for the shoe 100. In other embodiments, the interior surface of the base 120 represents a support surface for the footbed of the shoe 100.

[0023] The upper surface 110 of the sole component 102 may be slightly dished (concave) and contoured to accommodate, receive, and mate with the upper shell component 104. More specifically, the upper surface 110 of the sole component 102 may be contoured to receive the base 120 of the upper shell component 104. This feature makes it easier to assemble the two primary components of the shoe 100 in the manner described below. Moreover, the upper surface 110 of the sole component 102 may be contoured and/or it may include features designed to enhance comfort, fit, foot support, etc. For example, the upper surface 110 of the sole component 102 may define a heel cup area, an arch support area, or the like.

[0024] Referring again to FIG. 1 and FIG. 2, the outer surface of the base 120 is affixed to the upper surface 110 of the sole component 102 using, for example, an adhesive, glue, a welding agent, a bonding agent, or the like. Notably, the upper shell component 104 is attached to the sole component 102 in the absence of, and without requiring, any stitching, fasteners, snaps, buttons, rivets, or the like. In other words, the upper shell component 104 is coupled to the sole component 102 using no attachment mechanism or element other than the adhesive substance.

[0025] In practice, the sole component 102 is realized as a one-piece molded part. Although various molding techniques could be used, the exemplary embodiment described here is fabricated as an injection-molded part. In preferred embodiments, the sole component 102 is composed of an EVA material having the desired static, dynamic, and mechanical properties (e.g., density, resiliency, rebound, durability, toughness, and the like). Likewise, the upper shell component 104 is realized as a one-piece molded part, preferably an injection-molded part. In certain embodiments, the upper shell component 104 is also composed of an EVA material having the desired static, dynamic, and mechanical properties (e.g., density, resiliency, rebound, durability, toughness, and the like). [0026] Although not always required, it is desirable to fabricate the sole component 102 and the upper shell component 104 from different EVA materials, i.e., EVA materials having different static, dynamic, mechanical, and/or other properties or characteristics. For example, the sole component 102 may be composed of a first injection-molded EVA material having a first density, and the upper shell component 104 may be composed of a second injection-molded EVA material having a second density that is lower than the first density. Alternatively or additionally, the sole component 102 may be composed of a first injection-molded EVA material having a first resiliency, and the upper shell component 104 may be composed of a second injection-molded EVA material having a second resiliency that is lower than the first resiliency. This type of dual-density or dual- resiliency allows the shoe 100 to exhibit a relatively flexible and comfortable upper shell component 104 along with a high density and high rebound sole component 102.

[0027] The shoe 100 may be manufactured in accordance with the following exemplary fabrication process. The sole component 102 and the upper shell component 104 are molded (e.g., by injection-molding suitable EVA materials) using separate and distinct molds. As described above, the sole component 102 is molded from one type of EVA material having a relatively high density, while the upper shell component 104 is molded from another type of EVA material having a relatively low density. After the molding processes, the sole component 102 and the upper shell component 104 may be cleaned, inspected, trimmed, or otherwise prepared for the next stage of the

manufacturing process.

[0028] The sole component 102 and the upper shell component 104 are then affixed or otherwise joined together to form a two-piece assembly (see FIG. 2). In accordance with one approach, adhesive is applied to the upper surface 110 of the sole component 102, to the outer surface of the base 120 of the upper shell component 104, or to both. After the adhesive has been applied, the sole component 102 and the upper shell component 104 are mated together and held in the desired aligned position. In practice, the sole component 102 and the upper shell component 104 are maintained in this mated state for a period of time that allows curing or drying of the adhesive.

[0029] In certain embodiments, after the sole component 102 and the upper shell component 104 are coupled together, a foot- shaped last 140 is inserted into the upper shell component 104 (see FIG. 7). This maintains the desired shape of the upper shell component 104 while the adhesive sets. In addition, the last 140 may be used to distribute force (labeled " " in FIG. 7) over the base 120 of the upper shell component 104. The last 140 distributes the force in a more uniform manner to improve the integrity of the bond between the upper surface 110 of the sole component 102 and the outer surface of the base 120. It should be appreciated that force may be applied to the bottom surface 112 of the sole component 102 (in lieu of or in addition to force applied to the last 140). The desired amount of force is maintained for a period of time that is sufficient to create a strong and durable bond between the two primary components of the shoe 100.

[0030] After the sole component 102 has been secured to the upper shell component 104, the fabrication of the shoe 100 may proceed until completion. For the illustrated example, the shoelace retaining elements 106 are secured to the upper shell component 104, and the liner 108 is coupled within the upper shell component 104 (resulting in the state shown in FIG. 1). Additional manufacturing and packaging steps may be performed to prepare the shoe 100 for shipping, display, retail sale, etc.

[0031] It should be appreciated that some or all of the manufacturing process described above may be performed by automated equipment operated under the control of technicians and/or software. Moreover, it should be appreciated that an actual manufacturing process may include any number of additional or alternative steps that are not specifically mentioned here.

[0032] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.