US20110078922A1

US20110078922A1 - Thermoforming upper process with reinforcement

Info

Publication number: US20110078922A1
Application number: US12/572,441
Authority: US
Inventors: Sergio Cavaliere; Matteo Tessaro
Original assignee: Nike Inc
Current assignee: Nike Inc
Priority date: 2009-10-02
Filing date: 2009-10-02
Publication date: 2011-04-07
Also published as: CN102548443A; EP2482683A1; WO2011041053A1

Abstract

An article of footwear is provided and includes an upper having a medial side and a lateral side simultaneously formed from a single sheet of material in a thermoforming mold. The medial side and lateral side are joined to each other such that a joint between the medial side and the lateral side extends continuously from a heel portion of the upper to a toe portion of the upper.

Description

FIELD

The present disclosure relates to an article of footwear and a method of manufacturing an article of footwear.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.
Conventional footwear typically includes an upper structure, a strobel, and an outsole structure that cooperate to support a foot during use. The strobel connects a medial side of the upper structure to a lateral side of the upper structure and cooperates with the upper structure to securely receive and position the foot relative to the outsole structure. The outsole structure is typically secured to a lower portion of the strobel and generally between the foot and a ground surface and attenuates reaction forces by absorbing energy as the footwear contacts the ground.
Many of the processes for manufacturing conventional footwear are labor intensive and/or require numerous steps. Furthermore, each of the subassemblies of an article of footwear—an upper structure, strobel, and outsole structure—are often formed from separate and distinct processes with each employing a myriad of materials formed in numerous and distinct manufacturing processes.
The upper structure, for example, typically includes a series of different materials such as leather, plastic, nylon, and metal, each independently formed and joined together. In forming the leather portion, a blank of material is typically cut into the desired shape with the offal or scrap being discarded. The plastic pieces are typically molded in a separate manufacturing operation, as are the metal pieces such as eyelets, and are then separately and individually joined to the leather portion of the outsole structure. Because the leather components, plastic components, and metal components are all formed from different materials and are each formed in separate manufacturing processes, manufacturing a conventional upper structure requires an investment in tooling to form the individual components, and also requires subsequent assembly of the individual components. The additional tooling and manufacturing processes required to form the upper structure add to the overall cost and complexity of the article of footwear.
Once the upper structure is formed, the upper structure is typically attached to the strobel, which is manufactured in a separate manufacturing process and, as such, requires dedicated manufacturing tooling specific to formation of the material of the strobel. The strobel is subsequently attached to the upper structure by way of stitching and/or epoxy, thereby increasing the overall cost and complexity of the article of footwear.
Formation of the upper structure, strobel, and outsole structure necessarily generates offal or scrap. For example, forming the leather portion of the upper structure from a blank of leather material (i.e., a sheet of leather material) results in the material not used in forming the upper structure being discarded and, thus, wasted. Likewise, in manufacturing the strobel, forming the different layers of the strobel from different sheets of materials likewise results in waste when the strobel is trimmed into a desired shape. The offal or scrap generated during formation of the upper structure, strobel, and outsole structure is typically discarded or recycled but, nonetheless, adds to the overall cost of manufacturing the upper structure, strobel, and outsole structure and, as such, adds to the overall cost and complexity associated with manufacturing the article of footwear.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
An article of footwear is provided and includes an upper having a medial side and a lateral side simultaneously formed from a single sheet of material in a thermoforming mold. The medial side and lateral side are joined to each other such that a joint between the medial side and the lateral side extends continuously from a heel portion of the upper to a toe portion of the upper.
An upper for an article of footwear includes a medial portion having a first heel portion, a first bottom portion, and a first toe portion formed from a sheet of material in a thermoforming mold. The upper further includes a lateral portion having a second heel portion, a second bottom portion, and a second toe portion formed from the sheet of material in the thermoforming mold. The lateral portion is joined to the medial portion to attach the first heel portion to the second heel portion, to join the first bottom portion to the second bottom portion, and to join the first toe portion to the second toe portion.
A method of manufacturing an upper for an article of footwear is provided and includes providing a sheet of material, forming the sheet into a medial portion of the upper in a thermoforming mold, and forming the sheet into a lateral portion of the upper in a thermoforming mold. The method further includes separating the medial portion from the sheet, separating the lateral portion from the sheet, and attaching the medial portion to the lateral portion along a joint extending from a heel portion to a toe portion of the attached medial and lateral portions.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of an article of footwear according to the principles of the present disclosure;

FIG. 2 is an exploded view of the article of footwear of FIG. 1;

FIG. 3 is an exploded view of a multi-layer sheet according to the principles of the present disclosure for use in forming a portion of an article of footwear;

FIG. 4 is a perspective view of a mold according to the principles of the present disclosure for forming a portion of the article of footwear of FIG. 1;

FIG. 5 is a perspective view of an upper and tongue formed from the sheet of FIG. 3 in the mold of FIG. 4;

FIG. 6 is a perspective view of the tongue and medial and lateral portions of the upper separated from the sheet of FIG. 5;

FIG. 7A is a first perspective view of an upper of the article of footwear of FIG. 1 according to the principles of the present disclosure;

FIG. 7B is a second perspective view of the upper of the article of footwear of FIG. 1 according to the principles of the present disclosure;

FIG. 7C is a third perspective view of the upper of the article of footwear of FIG. 1 according to the principles of the present disclosure;

FIG. 8 is an exploded view of a sock liner for use with an article of footwear according to the principles of the present disclosure;

FIG. 9 is a perspective view of the article of footwear of FIG. 1 including an outsole according to the principles of the present disclosure; and

FIG. 10 is a perspective view of the article of footwear of FIG. 1 including an outsole according to the principles of the present disclosure.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
With reference to FIGS. 1 and 2, an article of footwear 10 is provided and includes an upper 12 and an outsole 14. The upper 12 receives a user's foot and cooperates with the outsole 14 to provide support and cushioning to the user's foot during use.
The upper 12 includes a medial portion 16, a lateral portion 18, and a tongue 20. The medial and lateral portions 16, 18 cooperate to define a generally hollow shell having an opening 19 through which the user's foot is inserted for use. The medial portion 16 includes a first side portion 22, a first toe portion 24, a first heel portion 26, and a first bottom portion 28. The lateral portion 18 includes a second side portion 30, a second toe portion 32, a second heel portion 34, and a second bottom portion 36.
The tongue 20 is attached to the medial and lateral portions 16, 18. Laces 38 engaging the medial and lateral portions 16, 18 can draw the medial and lateral portions 16, 18 towards each other to secure the user's foot within the upper 12. The tongue 20 improves the overall aesthetics of the article of footwear 10 and protects the user's foot by preventing the laces 38 from rubbing against a dorsal portion of the user's foot during use. In one configuration, the tongue 20 includes reinforcements 39 to provide additional support and protection for the user's foot.
An optional sock liner 40 may be disposed within the upper 12 and may provide additional cushioning and shock absorption to the user's foot during use. The sock liner 40 may include a structural layer 42 and a cushioning layer 44. The structural layer 42 is relatively rigid and may be formed from a hard polymeric material. The cushioning layer 44 is relatively soft and is formed from a compliant foam or other polymeric material that cushions and/or directs moisture away from the foot. The sock liner 40 is adhesively bonded, stitched, or otherwise suitably attached to the first and second sole portions 28, 36.
An optional collar 46 may be disposed on a rim of the opening 19 of the upper 12 to reinforce the opening 19. The collar 46 is a generally U-shaped member formed from a rigid polymeric material. The collar 46 improves the overall aesthetics of the article of footwear 10 and provides support for the user's ankle during use. A cushioning material such as foam (not shown) may be disposed along an inner portion of the collar 46 to provide additional comfort during use. The collar 46 is adhesively bonded or otherwise suitably attached to the rim of the opening 19.
An optional toe cover 48 may be disposed over a joint between the first and second toe portions 24, 32 of the upper 12 and may be formed from a generally rigid polymeric material. The toe cover 48 improves the aesthetics of the article of footwear 10 and provides protection for the phalanges and metatarsals of the user's foot during use. The toe cover 48 is adhesively bonded or otherwise suitably fixed to the first and second toe portions 24, 32 and generally covers a junction of the medial and lateral portions 16, 18.
The outsole 14 includes a plate 50 and an integrated heel counter 52. The plate 50 is formed from a rigid material relative to the first and second bottom portions 28, 36 to provide the article of footwear 10 with support. While the plate 50 is described as being rigid, the plate 50 is sufficiently flexible to allow a user to comfortably walk, run and agilely maneuver during use. The plate 50 can be adhered directly to the first and second sole portions 28, 36 of the upper 12. Alternatively, a midsole (not shown) can be disposed between the plate 50 and the first and second sole portions 28, 36 of the upper 12. In the particular configuration illustrated in FIG. 2, the plate 50 includes a plurality of cutouts 54 that reduce the overall weight of the article of footwear 10, improve the flexibility of the outsole 14, and improve the aesthetics of the article of footwear 10.
The plate 50 may also include a plurality of integrally formed cleats 56. The cleats 56 are shaped, sized and arranged to optimize grip and traction between the user's foot and a turf or dirt surface during use for a given application or sport during which the article of footwear 10 is intended to be worn. In other configurations, the plate 50 may include a tread pattern 58 instead of the cleats 56 (FIG. 10). The plate 50 may include the tread pattern 58, which may be optimized for other applications such as running, walking, and cross-training, for example. In still other configurations, the plate 50 may include other protrusions, spikes, contours and/or other features in addition to or in place of the cleats 56 and/or tread pattern 58. Such protrusions, spikes, contours and/or features may optimize grip and traction between the user's foot and the ground or floor for a given application, thereby improving the user's performance. In any of the foregoing configurations, the cleats 56 tread pattern 58, protrusions, spikes, contours, and/or other features may be integrally formed with the plate 50 during formation of the plate 50. Following formation of the plate 50, the plate 50 may be attached to a bottom portion of the joined medial and lateral portions 16, 18, as will be described below.
The heel counter 52 is integrally formed with the plate 50 and includes a plurality of transverse structural members 60 and one or more vertical structural members 62 that cooperate to provide rigidity and support for the user's heel. While the heel counter 52 is described as being integrally formed with the plate 50, the heel counter 52 could be a separate component apart from the outsole 14 and could be molded into the upper 12 or inserted between a rear portion of the upper 12 and an interior liner (not shown) of the upper 12.
With reference to FIGS. 1-10, a method of manufacturing the article of footwear 10 will be described. The upper 12 and tongue 20 are formed from a single sheet of material 102 (FIG. 3), thereby reducing wasted material. The sheet of material 102 may include one or more layers 104 of a material or a plurality of materials. Such material or materials may be selected to provide support and protection for the user's foot, while also providing ventilation for cooling the foot and removing perspiration. The sheet of material 102 may include localized reinforcements 106 that are sized, shaped, and positioned to provide additional support and/or protection for predetermined portions of the user's foot (e.g., the calcaneous, metatarsals, phalanges, and/or cuneiforms) when the sheet of material 102 is formed into the upper 12. The localized reinforcements 106 may be areas of increased thickness in the sheet of material 102 and/or may include additional layers of rigid materials disposed on or between the layers 104 of the sheet of material 102.
The sheet of material 102 is thermoformed in a mold 110 having a first portion 111 and a second portion 113 (FIG. 4) that cooperate to simultaneously form the shapes of the medial portion 16, the lateral portion 18, and the tongue 20 (FIG. 5). During the thermoforming process, the first side portion 22, first toe portion 24, first heel portion 26, and first bottom portion 28 of the medial portion 16, as well as the second side portion 30, second toe portion 32, second heel portion 34, and second bottom portion 36 of the lateral portion 18 are formed simultaneously in the mold 110 generally between the first portion 111 and the second portion 113. The mold 110 illustrated in FIG. 4 is configured to form the upper 12 for the article of footwear 10 having a predetermined size and corresponding to the user's right foot. A second mold (not shown) is configured to form an upper for an article of footwear having the predetermined size and corresponding to the user's left foot.
The molds 110 may be formed in a variety of predetermined sizes to form uppers corresponding to a variety of users' foot sizes, including children's sizes and/or adults' sizes. Accordingly, a facility for manufacturing the upper 12 of the present disclosure may be equipped with a plurality of molds 110, each corresponding to one of a plurality of predetermined sizes.
After being formed from the sheet of material 102, the medial portion 16, lateral portion 18, and tongue 20 are separated from the sheet of material 102, as shown in FIG. 6. The medial portion 16, lateral portion 18, and tongue 20 may be separated from the sheet of material 102 and from each other via a laser cutting process, for example, or via any other automated or manual cutting process. Flash or scrap material 112 may be discarded or recycled. Because the tongue 20 is formed from the same sheet of material 102 as the medial portion 16 and the lateral portion 18, the method of manufacturing the article of footwear 10 disclosed herein reduces the amount of scrap material. Specifically, because the area of the sheet of material 102 disposed between the medial portion 16 and the lateral portion 18 is not used in forming the medial portion 16 or the lateral portion 18, this material is wasted and must either be discarded or recycled. Forming the tongue 20 in this region between the medial portion 16 and lateral portion 18 reduces the amount of material that must be discarded or recycled and, as such, reduces the overall cost and complexity associated with manufacturing the article of footwear 10.
After the medial portion 16 and the lateral portion 18 are separated from the sheet of material 102 and from each other, the medial and lateral portions 16, 18 are joined together to form the upper 12 including a unitary toe portion 114, a unitary heel portion 116, and a unitary bottom portion 118, as shown in FIGS. 7A-7C. The medial portion 16 and lateral portion 18 are fastened directly to each other at a joint 120 disposed between the medial portion 16 and the lateral portion 18.
The medial portion 16 and the lateral portion 18 may be attached to one another at the joint 120 by stitching, high-frequency welding, and/or adhesively bonding the medial portion 16 directly to the lateral portion 18. Such stitching, high-frequency welding, and/or adhesive may extend along the entire joint 120 or, alternatively, may be selectively applied at discrete locations along the joint 120.
The joint 120 extends continuously from a top portion of the heel portion 116 and across the bottom portion 118 and the toe portion 114. In this manner, the first and second toe portions 24, 32 form the unitary toe portion 114, the first and second heel portions 26, 34 form the unitary heel portion 116, and the first and second bottom portions 28, 36 form the unitary bottom portion 118, as shown in FIGS. 7A-7C. Because the medial and lateral portions 16, 18 include first and second bottom portions 28, 36 that are joined together to form the unitary bottom portion 118, the article of footwear 10 can be manufactured without a strobel.
The tongue 20 is stitched, high-frequency welded, and/or adhesively bonded to the medial and lateral portions 16, 18. The tongue 20 may be secured to the medial and lateral portions 16, 18 before, during, or after the medial and lateral portions 16, 18 are secured to each other.
The structural layer 42 and cushioning layer 44 of the optional sock liner 40 may be molded, laser cut, or otherwise formed from corresponding sheets or blanks of material (not shown). The structural layer 42 and cushioning layer 44 may be stitched, adhesively bonded, and/or high-frequency welded together to form the sock liner 40. The sock liner 40 can be formed before, during, or after molding the upper 12. Optionally, the sock liner 40 may be inserted into the upper 12 and may be stitched, adhesively bonded, and/or high-frequency welded on an inner side of the bottom portion 118 of the upper 12.
After the upper 12 is formed by securing the medial portion 16 and lateral portion 18 to each other, the outsole 14 may be over-injected or injection molded directly onto the upper 12. The plate 50 may be formed directly on an outer side of the bottom portion 118 such that the heel counter 52 is simultaneously formed directly on the heel portion 116. A single mold (not shown) is used to substantially simultaneously form the plate 50, the heel counter 52, and, optionally, the cleats 56 or tread pattern 58.
In some embodiments, a midsole (not shown) may be disposed between the bottom portion 118 of the upper 12 and the outsole 14 to provide the article of footwear 10 with a layer of shock-absorbing material. The midsole may be directly attached to the bottom portion 118 of the upper 12 via a suitable adhesive and may likewise be attached to the plate 50 by a suitable adhesive.
The heel counter 52 is formed onto the upper 12 separately from the plate 50 and may be attached to the upper 12 by an adhesive. The heel counter 52 could alternatively be disposed between layers 104 of the sheet of material 102 and may be formed simultaneously with the medial and lateral portions 16, 18 in the mold 110. For example, the localized reinforcements 106 may be inserted into the sheet of material 102 and/or mold 110 in a region of the heel such that when the medial portion 16 and the lateral portion 18 are formed in the mold 110, respective halves or portions of the heel counter 52 are likewise formed. When the medial portion 16 and the lateral portion 18 are joined, the halves of the heel counter 52 formed from the localized reinforcements 106 are likewise joined and cooperate to form the heel counter 52.
The collar 46 and/or toe cover 48 are separately injection molded or otherwise molded, machined, or formed. After the medial portion 16 and lateral portion 18 are secured together, the collar 46 and/or toe cover 48 are attached to the upper 12. The collar 46 is attached to the upper 12 at a rim of the opening 19 (FIG. 1) via adhesive bonding, stitching, and/or high-frequency welding, for example. The toe cover 48 is disposed over the joint 120 on the toe portion 114 of the upper 12 and attached thereto via adhesive bonding, stitching, and/or high-frequency welding, for example. In another configuration, the collar 46 and/or toe cover 48 are over-injected onto the upper 12 in a similar fashion as the process described above, whereby the outsole 14 is over-injected onto the upper 12. The collar 46 and/or toe cover 48 may be formed integrally with the medial and lateral portions 16, 18 in the mold 110 by placing localized reinforcements 106 in an area around the collar 46 and/or toe cover 48 such that when the medial and lateral portions 16, 18 are joined, the localized reinforcements 106 are likewise joined and form the opening 19 and/or toe cover 48.
Regardless of how the collar 46, toe cover 48, and heel counter 52 are formed, providing the collar 46, toe cover 48, and heel counter 52 with a material of increased rigidity and/or thickness may be advantageous depending on the particular application of the article of footwear 10. For example, if the article of footwear 10 is designed for use in a sport such as soccer, increasing the thickness and/or rigidity of the toe cover 48 aids in applying a force and striking a ball. However, if the article of footwear 10 is designed for use in a sport such as running or jogging, providing the article of footwear 10 with a relatively rigid collar 46, toe cover 48, or heel counter 52 provides little to no benefit to the user during the intended activity. In such a configuration, the sheet of material 102 may not include localized reinforcements 106 but, rather, may include a generally uniform thickness.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims

1. An article of footwear comprising:

an upper including a medial side and a lateral side simultaneously formed from a single sheet of material in a thermoforming mold and joined to each other such that a joint between said medial side and said lateral side extends continuously from a heel portion of said upper to a toe portion of said upper.

2. The article of footwear according to claim 1, further comprising a tongue connected to said upper and formed simultaneously with said medial and lateral sides from said single sheet of material.

3. The article of footwear according to claim 1, further comprising an outsole disposed on a bottom portion of said upper.

4. The article of footwear according to claim 3, wherein said outsole is over-injected directly onto said upper.

5. The article of footwear according to claim 3, wherein said outsole includes a tread pattern or a plurality of integrally formed cleats.

6. The article of footwear according to claim 3, further comprising a counter integrally formed with said outsole.

7. The article of footwear according to claim 1, further comprising a toe cover disposed over a portion of said joint.

8. The article of footwear according to claim 1, wherein said sheet of material includes at least one localized thick spot operable to form an area of increased strength on said upper.

9. The article of footwear according to claim 1, wherein said area of increased strength is at least one of a heel counter and a toe counter.

10. The article of footwear according to claim 1, further comprising at least one reinforcement member molded into at least one of said medial side and said lateral side.

11. The article of footwear according to claim 1, wherein said joint between said medial and lateral sides is formed by at least one of stitching, high-frequency welding, and adhesive bonding.

12. An upper for an article of footwear, the upper comprising:

a medial portion including a first heel portion, a first bottom portion, and a first toe portion formed from a sheet of material in a thermoforming mold; and

a lateral portion including a second heel portion, a second bottom portion, and a second toe portion formed from said sheet of material in said thermoforming mold, said lateral portion joined to said medial portion to attach said first heel portion to said second heel portion, said first bottom portion to said second bottom portion, and said first toe portion to said second toe portion.

13. The upper according to claim 12, wherein said medial portion is attached to said lateral portion along a continuous joint extending from a joint between said first and second heel portions, along a joint between said first and second bottom portions, and to a joint between said first and second toe portions.

14. The upper according to claim 13, wherein said continuous joint is formed by at least one of stitching, high-frequency welding, and adhesive bonding.

15. The upper according tot claim 14, further comprising a tongue formed simultaneously from said sheet of material.

16. The upper according to claim 12, further comprising an outsole over-injected directly onto said first bottom portion and said second bottom portion.

17. The upper according to claim 16, wherein said outsole includes a tread pattern or a plurality of integrally formed cleats.

18. The upper according to claim 16, further comprising a counter integrally formed with said outsole.

19. The upper according to claim 12, further comprising integrally formed counter halves respectively formed with said medial portion and said lateral portion.

20. The upper according to claim 12, further comprising at least one reinforcement member molded into at least one of said medial portion and said lateral portion.

21. A method of manufacturing an upper for an article of footwear, the method comprising:

providing a sheet of material;

forming said sheet into a medial portion of the upper in a thermoforming mold;

forming said sheet into a lateral portion of the upper in a thermoforming mold;

separating said medial portion from said sheet;

separating said lateral portion from said sheet; and

attaching said medial portion to said lateral portion along a joint extending from a heel portion to a toe portion of said attached medial and lateral portions.

22. The method of claim 21, wherein said forming steps are performed in the same mold.

23. The method of claim 21, wherein said separating includes laser cutting said medial portion and said lateral portion from said sheet.

24. The method of claim 21, wherein said joining includes at least one of stitching, high-frequency welding, and adhesively bonding.

25. The method of claim 21, wherein said joining includes forming a continuous joint between said medial portion and said lateral portion extending from said heel portion to said toe portion.

26. The method of claim 21, further comprising forming an outsole over a bottom portion of said joined medial and lateral portions.

27. The method of claim 26, wherein said forming said outsole includes over-injecting said outsole onto said joined medial and lateral portions.

28. The method of claim 21, further comprising forming a reinforced heel counter on said medial and lateral portions.

29. The method of claim 28, wherein first and second portions of said reinforced heel counter are formed simultaneously with said medial and lateral portions.

30. The method of claim 21, further comprising positioning a sock liner within said joined medial and lateral portions.