The present disclosure relates generally to methods for manufacturing articles of footwear. More specifically, aspects of this disclosure relate to mechanical features for retaining segments of an article of footwear on a last during assembly of the footwear.
Articles of footwear, such as shoes, boots, slippers, sandals, and the like, are generally composed of two primary elements: an upper for securing the footwear to a user's foot; and a sole for providing subjacent support to the foot. Uppers may be fabricated from a variety of materials, including textiles, foams, polymers, natural and synthetic leathers, etc., that are stitched or bonded together to form a shell or harness for securely receiving a foot. For sandals and slippers, the upper may have an open toe or open heel construction, or may be generally limited to a series of straps extending over the instep and, in some designs, around the user's ankle. Conversely, boot and shoe applications typically employ a full upper with a closed toe and heel construction that encases the foot. An ankle opening through a rear quarter portion of the upper provides access to the footwear's interior, facilitating entry and removal of the foot into and from the upper. A lace or strap may be utilized to secure the foot within the upper.
A sole structure is generally attached to the underside of the upper, positioned between the user's foot and the ground. In many articles of footwear, including athletic shoes and boots, the sole structure is a layered construction that generally incorporates a comfort-enhancing insole, an impact-mitigating midsole, and a surface-contacting outsole. The insole, which may be located partially or entirely within the upper, is a thin and compressible member that provides a contact surface for the underside “plantar” region of the user's foot. By comparison, the midsole is mounted underneath the insole, forming a middle layer of the sole structure. In addition to attenuating ground reaction forces, the midsole may help to control foot motion and impart enhanced stability. Secured to the underside of the midsole is an outsole that forms the ground-contacting portion of the footwear. The outsole is usually fashioned from a durable, wearproof material that includes tread patterns engineered to improve traction.
Available techniques for fabricating an article of footwear may begin with interconnecting the individual pieces of material that form a forward “vamp” portion of the footwear's upper. An optional inner liner may then be joined to the interior surfaces of one or more exterior panels of the vamp. For designs where the vamp is formed separate from the toe box, a matching toe cap is stitched or bonded to the foreword end of the vamp. This pre-constructed assembly is then seated on a complementary fixture—more commonly known as a “last”—that has the general shape of a human foot. Historically, a pin, clip, shim, or spring-biased tang is used to temporarily fasten the assembly to the last. An assortment of processes may then be utilized to tighten the upper around the last, thereby imparting the foot-shaped contour of the last to the interior of the upper. In order to conform the upper of an athletic shoe around a last, for example, a strobel material may be secured to a lower perimeter of the upper and stretched across an area of the last corresponding to the plantar surface of the foot. A heel counter is affixed to a rearward end of the vamp, and the sole structure is secured to the underside of the upper to generally enclose the strobel between the upper and sole structure.
Presented herein are methods for constructing articles of footwear using sacrificial straps to secure segments of the footwear to a manufacturing fixture, shoe structure segments prefabricated with such sacrificial straps, systems for manufacturing articles of footwear using sacrificial straps, and methods for operating such systems. By way of example, there is presented a manufacturing process workflow for fabricating an athletic shoe using a sacrificial heel strap to temporarily secure the forward vamp and attached strobel to a last. Upon completing the manufacturing procedure or procedures associated with the last, such as attachment of the heel counter and sole structure to the vamp, the sacrificial heel strap is permanently removed. In this example, the sacrificial heel strap may generally consist of a thin, elongated strip of material that is removably attached at opposing ends thereof proximal the welt line of the vamp. This sacrificial heel strap may be formed from a material that is different from and structurally inferior to that of the other segments of the shoe. The material may be frangible, easily cut, or fabricated with features to facilitate removal of the strap, such as a tear seam or micro-slots. In addition, the heel strap may be configured to fit inside the upper, e.g., adjacent a heel cap/rear quarter of the shoe structure, yet be readily accessible for ease of removal of the strap once the shoe is pulled from the last.
Aspects of this disclosure are directed to manufacturing processes for constructing footwear. In an example, a method is presented for manufacturing an article of footwear for a foot of a user. This representative method includes, in any order and in any combination with any of the above or below disclosed features and options: providing a first segment of an upper, wherein the upper is configured to attach to the user's foot and includes a sacrificial strap that is attached at opposing ends thereof to the first segment; placing the first segment of the upper on a manufacturing fixture; attaching the first segment to the manufacturing fixture by positioning the sacrificial strap against the manufacturing fixture; attaching a second segment of the upper to the first segment; removing the first and second segments from the fixture; and disconnecting the sacrificial strap from the upper.
In another example, a method is presented for assembling an athletic shoe. This representative method includes, in any order and in any combination with any of the above or below disclosed features and options: providing a foot-shaped last with a forefoot region, a heel region, and a midfoot region interposed between and adjoining the heel and forefoot regions; placing a vamp segment of the athletic shoe's upper, e.g., with an attached strobel, on at least the forefoot region of the last, the upper including a sacrificial strap that is removably attached at opposing ends thereof proximate a rear edge of the vamp; temporarily attaching the vamp to the last by positioning the sacrificial strap around and against at least the heel region of the last; attaching a heel counter to the vamp, e.g., via stitching, bonding, or other suitable means; attaching a sole structure of the athletic shoe to the vamp and heel counter, e.g., via welting, foxing, or other suitable means; after attaching the heel counter and sole structure to the vamp, removing the vamp, heel counter and sole structure from the last; and, after removing the assembled athletic shoe from the last, tearing or cutting the sacrificial strap from the upper.
Further aspects of the disclosure are directed to pre-assembled segments of an article of footwear with sacrificial straps. For instance, an article of footwear includes an upper that receives and attaches to a foot of a user. The upper is fabricated with a vamp, a heel counter that rigidly attaches to the vamp, and a sacrificial strap that nests inside the heel counter and removably attaches at opposing ends thereof proximate a rear edge of the vamp. The article of footwear also includes a sole structure that attaches to a lower portion of the upper and supports thereon the user's foot. The sole structure includes an outsole that defines the ground-engaging portion of the footwear. After assembling the footwear, the sacrificial strap is configured to be permanently disconnected from upper.
Other aspects of the present disclosure are directed to manufacturing systems for constructing an article of footwear. In an example, a footwear manufacturing system includes a flat machine that constructs a first segment of an upper with a sacrificial strap that is attached at opposing ends thereof to the first segment. The manufacturing system also includes a last with a foot-shaped section that seats thereon the various segments of the upper. One or more of these segments may be mechanically attached to the last by positioning the sacrificial strap against the last. After being securely attached to the last, the segments of the upper are rigidly attached to each other. A finishing bench receives the attached segments of the upper such that the sacrificial strap can be permanently removed from the upper.
For any of the disclosed systems, methods, and devices, disconnecting the sacrificial strap from the upper may include cutting the sacrificial strap off of the first segment. To facilitate removal, the sacrificial strap may be fabricated from a polymeric material and/or textile material, both of which are configured to be readily cut, e.g., by a pair of manually operated scissors. Optionally, the sacrificial strap may be fabricated with a reduced-thickness section and/or a slotted section, both of which facilitate cutting the strap. Alternatively, disconnecting the sacrificial strap from the upper may include tearing the sacrificial strap off of the first segment. To facilitate removal by tearing, the sacrificial strap may be fabricated from a frangible material that is configured to be readily torn. Optionally, the sacrificial strap may be fabricated with a tear seam that includes a series of apertures and/or micro-slots that facilitate tearing of the strap.
For any of the disclosed systems, methods, and devices, the first segment may be fabricated with a first material while the sacrificial strap is fabricated with a second material that is distinct from the first material of the first segment. As another option, the sacrificial strap may consist essentially of an elongated, single-piece sling that is bonded or stitched to the first segment. In other words, the sacrificial strap may be characterized by a lack of a buckle, buckle through holes, surface finishing, interior lining, and other features characteristic of permanent straps used for sandals, high-heeled shoes, etc. As indicated above, the first segment of the upper to which the sacrificial strap is attached may be a vamp segment of the upper; however, it is envisioned that sacrificial straps may be attached to other segments of the shoe structure to facilitate assembly of the footwear. For instance, the first and second segments discussed above may include a vamp segment, a strobel segment attached to the vamp segment, and/or a heel counter segment.
The above summary is not intended to represent every embodiment or every aspect of the present disclosure. Rather, the foregoing summary merely provides an exemplification of some of the novel concepts and features set forth herein. The above features and advantages, and other features and attendant advantages of this disclosure, will be readily apparent from the following detailed description of illustrated examples and representative modes for carrying out the present disclosure when taken in connection with the accompanying drawings and the appended claims. Moreover, this disclosure expressly includes any and all combinations and subcombinations of the elements and features presented above and below.
The present disclosure is amenable to various modifications and alternative forms, and some representative embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the above-enumerated drawing. Rather, the disclosure is to cover all modifications, equivalents, combinations, subcombinations, permutations, groupings, and alternatives falling within the scope of this disclosure as encompassed by the appended claims.
This disclosure is susceptible of embodiment in many different forms. There are shown in the drawings and will herein be described in detail representative embodiments of the disclosure with the understanding that these illustrated examples are provided as an exemplification of the disclosed principles, not limitations of the broad aspects of the disclosure. To that extent, elements and limitations that are described, for example, in the Abstract, Technical Field, Background, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise.
For purposes of the present detailed description, unless specifically disclaimed: the singular includes the plural and vice versa; the words “and” and “or” shall be both conjunctive and disjunctive; the words “any” and “all” shall both mean “any and all”; and the words “including” and “comprising” and “having” shall each mean “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “generally,” “approximately,” and the like, may be used herein in the sense of “at, near, or nearly at,” or “within 0-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof, for example. Lastly, directional adjectives and adverbs, such as fore, aft, medial, lateral, proximal, distal, vertical, horizontal, front, back, left, right, etc., may be with respect to an article of footwear when worn on a user's foot and operatively oriented with the base of the sole structure seated on a flat surface, for example.
Referring now to the drawings, wherein like reference numbers refer to like features throughout the several views,
The representative article of footwear 12 is depicted in
With continuing reference to
The upper 14 portion of the footwear 12 may be fabricated from any one or combination of a variety of materials, such as textiles, engineered foams, polymers, natural and synthetic leathers, etc. Individual segments of the upper 14, once cut to shape and size, are stitched, adhesively bonded, welded, or otherwise joined together to form an interior void for comfortably receiving a foot. The individual material elements of the upper 14 may be selected and located with respect to the footwear 12 in order to impart properties of durability, air-permeability, wear-resistance, flexibility, and comfort, for example. An ankle opening 11 (
Sole structure 16 is rigidly secured to the upper 14 such that the sole structure 16 extends between the upper 14 and a support surface upon which a user stands, for example. In effect, the sole structure 16 functions as an intermediate support platform that separates the user's foot from the ground. In addition to attenuating ground reaction forces and providing cushioning for the foot, sole structure 16 of
In accordance with the illustrated example, the sole structure 16 is fabricated as a sandwich structure with a top-most insole 30, an intermediate midsole 32, and a bottom-most outsole 34. Insole 30 is shown located partially within the interior void of the footwear 12, firmly secured to a lower portion of the upper 14, such that the insole 30 is located adjacent a plantar surface of the foot. Underneath the insole 30 is a midsole 32 that incorporates one or more materials or embedded elements that enhance the comfort, performance, and/or ground-reaction-force attenuation properties of footwear 12. These elements and materials may include, individually or in any combination, a polymer foam material, such as polyurethane or ethylene-vinyl acetate (EVA), filler materials, moderators, air-filled bladders, plates, lasting elements, or motion control members. Outsole 34, which may be absent in some configurations of footwear 12, is secured to a lower surface of the midsole 32. The outsole 34 may be formed from a rubber material that provides a durable and wear-resistant surface for engaging the ground. In addition, outsole 34 may also be textured to enhance the traction (i.e., friction) properties between footwear 12 and the underlying support surface.
A variety of techniques, elective processes, and system architectures may be utilized to manufacture the athletic shoe 12. An example of a footwear manufacturing system 10 and attendant workflow process that incorporates the use of one or more sacrificial straps 40 to fabricate an article of footwear 12 are set forth in
Initial stages of the manufacturing process may comprise supplying, accessing, and/or utilizing (collectively “providing”) the various materials, tools and machines needed to manufacture the athletic shoe 12. By way of non-limiting example, the representative footwear manufacturing system 10 of
Shoe last 46 of
During assembly of the athletic shoe 12, the vamp 18 segment of the upper 14 is loosely placed on a complementary forward section of the last 46 (e.g., that section associated with the forefoot and midfoot regions RFF and RMF and extending over the extensor hallucis and extensor digitorum ligaments of the foot), as indicated at step S4. Strobel 24 is concomitantly stretched across the underside surface of the last 46, which may generally correspond to the plantar surface of the foot, as seen in
Turning next to
Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; those skilled in the art will recognize, however, that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, changes, and variations apparent from the foregoing descriptions are within the scope of the disclosure as defined by the appended claims. Moreover, the present concepts expressly include any and all combinations and subcombinations of the preceding elements and features.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/676,572, which was filed on May 25, 2018, and is incorporated herein by reference in its entirety and for all purposes.
Number | Date | Country | |
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62676572 | May 2018 | US |