Footwear with removable midsole having projections

An article of footwear includes an upper and an upper plate secured to the upper and having a plurality of apertures formed therein. A removable midsole has a plurality of projections extending from a lower surface thereof, with each projection extending through one of the apertures of the upper plate.

FIELD OF THE INVENTION

This invention relates generally to footwear, and, in particular, to footwear with a removable midsole having projections received in apertures formed in an upper plate secured to an upper.

BACKGROUND OF THE INVENTION

Conventional articles of athletic footwear include an upper and a sole structure that are specifically designed for use in particular athletic activities. Running shoes, for example, incorporate a lightweight upper that provides the foot with ventilation, thereby decreasing the overall weight of the footwear and removing perspiration from the area surrounding the foot. Sole structures for running shoes are generally designed to provide a high degree of cushioning, which includes ground reaction force attenuation and energy absorption, and may incorporate motion control components for reducing the inward roll of the foot following footstrike. Basketball shoes generally incorporate an upper that protects the ankle from sprains and a sole that provides stability during the commonly executed lunges and quick direction changes. Finally, the sole structures for soccer shoes and football shoes may incorporate spikes that provide a high degree of traction on natural turf playing fields.

Despite the differences between the various footwear styles, sole structures for conventional footwear generally include multiple layers that are referred to as an insole, a midsole, and an outsole. The insole is a thin, cushioning member located adjacent to the foot that enhances footwear comfort. The midsole forms the middle layer of the sole and serves a variety of purposes that include controlling potentially harmful foot motions, such as over pronation; shielding the foot from excessive ground reaction forces; and beneficially utilizing such ground reaction forces for more efficient toe-off. The outsole forms the ground-contacting element of footwear and is usually fashioned from a durable, wear resistant material that includes texturing to improve traction.

The primary element of a commonly-employed type of conventional midsole is a resilient, polymer foam material, such as polyurethane or ethylvinylacetate, that extends throughout the length and width of the footwear. In designing the midsole, footwear manufacturers balance the manner in which the midsole provides cushioning with stability. In general, a relatively thick midsole will provide greater cushioning than a relatively thin midsole, but will also have less stability than the relatively thin midsole.

As an alternative, U.S. Pat. Nos. 5,353,523 and 5,343,639 to Kilgore et al., hereby incorporated by reference, discloses an article of athletic footwear with a midsole that includes foam columns placed between semi-rigid upper and lower plates. In general, the foam columns support the entire heel portion of the foot. The heel portion of a conventional article of footwear generally includes a block of foam material and may incorporate fluid-filled bladders, as disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 to Rudy. In contrast, the heel portion of the footwear disclosed in the Kilgore patents includes foam columns and a void that extends through the columns. Unlike many conventional midsole materials, therefore, the foam columns generally utilize a foam with a higher density to provide greater support per unit-volume of foam material.

The performance characteristics of the foam columns disclosed in the Kilgore patents are primarily dependent upon factors that include the dimensional configurations of the columns and the properties of the foam material selected for the columns. By designing the columns to have specific dimensions and foam properties, cushioning and stability of the footwear may be generally tuned to meet the specific demands of the activity for which the footwear is intended to be used. In running shoes, for example, the dimensions and foam properties may be selected to provide greater cushioning. Similarly, the configuration of the columns may also be selected to provide enhanced stability in basketball shoes.

As stated above, cushioning and stability may be generally tuned to meet the specific demands of a particular activity. In general, the dimensions and foam properties will be selected to accommodate specific weights of the wearer, a generally preferred degree of cushioning, a particular activity, a specific ground surface, and a certain degree of motion control. A particular pair of footwear, however, may be purchased and worn by individuals with a wide range of weights that prefer different degrees of cushioning. In addition, the footwear may be used for varying activities on ground surfaces with a wide variety of compliance characteristics. In addition, different wearers may require different degrees of pronation or supination control.

It would be desirable to provide an article of footwear that reduces or overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain embodiments.

SUMMARY

The principles of the invention may be used to advantage to provide an article of footwear with a removable midsole having projections. In accordance with a first aspect, an article of footwear includes an upper and an upper plate secured to the upper and having a plurality of apertures formed therein. A removable midsole has a plurality of projections extending from a lower surface thereof, with each projection extending through one of the apertures of the upper plate.

In accordance with another aspect, an article of footwear includes an upper and an upper plate secured to the upper. A plurality of first apertures is formed in a forefoot portion of the upper plate. A plurality of second apertures is formed in a heel portion of the upper plate. A plurality of hollow support columns extends downwardly from the heel portion of the plate, with each hollow support column being one of transparent and translucent. A removable midsole has a plurality of first projections and a plurality of second projections. Each first projection is configured to extend through one of the first apertures in the upper plate, and each second projection is configured to extend through one of the second apertures in the upper plate and be received in one of the hollow support columns. Each of a plurality of outsole elements is secured to a lower surface of one of the support columns.

In accordance with a further aspect, an article of footwear includes an upper and an upper plate secured to the upper. A plurality of first apertures is formed in a forefoot portion of the upper plate. A plurality of second apertures is formed in a heel portion of the upper plate. A plurality of hollow support columns extends downwardly from the heel portion of the plate, with each hollow support column being one of transparent and translucent. A lower plate extends rearwardly from a midfoot portion of the upper plate and has a plurality of apertures formed therein, with each aperture receiving a portion of one of the hollow support columns. A removable midsole has a plurality of first projections and a plurality of second projections. Each first projection is configured to extend through one of the first apertures in the upper plate. The first projections are arranged in a plurality of rows extending substantially transversely across the midsole and a plurality of columns extending substantially longitudinally along the midsole. Each second projection is configured to extend through one of the second apertures in the upper plate and be received in one of the hollow support columns. Each of a plurality of first slits extends between adjacent rows of first projections. Each of a plurality of second slits extends between adjacent columns of first projections. Each of a plurality of outsole elements is secured to a lower surface of one of the support columns.

Substantial advantage is achieved by providing footwear with a removable midsole having projections. In particular, the removable midsole allows midsoles with different characteristics to be inserted and removed in the footwear when desired. For example, midsoles with different performance or aesthetic characteristics can be easily exchanged whenever desired by the user.

These and additional features and advantages disclosed here will be further understood from the following detailed disclosure of certain embodiments.

The figures referred to above are not drawn necessarily to scale and should be understood to provide a representation of the invention, illustrative of the principles involved. Some features of the footwear with a removable midsole having projections depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. The same reference numbers are used in the drawings for similar or identical components and features shown in various alternative embodiments. Footwear with a removable midsole having projections as disclosed herein would have configurations and components determined, in part, by the intended application and environment in which they are used.

DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS

The present invention may be embodied in various forms. A preferred embodiment of an article of footwear10is shown inFIGS. 1-3. Footwear10includes an upper12that forms an interior void that comfortably receives a foot and secures the position of the foot. The configuration of upper12, as depicted, is suitable for use during athletic activities, e.g., running. Accordingly, upper12may have a lightweight, breathable construction that includes multiple layers of leather, textile, polymer, and foam elements adhesively bonded and stitched together. For example, upper12may have an exterior that includes leather elements and textile elements for resisting abrasion and providing breathability, respectively. The interior of upper12may have foam elements for enhancing the comfort of footwear10, and the interior surface may include a moisture-wicking textile for removing excess moisture from the area immediately surrounding the foot.

For purposes of general reference, as illustrated here, footwear10may be divided into three general portions: a forefoot portion14, a midfoot portion16, and a heel portion18. Portions14,16, and18are not intended to demarcate precise areas of footwear10. Rather, portions14,16, and18are intended to represent general areas of footwear10that provide a frame of reference during the following discussion.

Footwear10also includes a lateral side20and a medial side22. Forefoot portion14generally includes portions of footwear10corresponding with the toes and the joints connecting the metatarsals with the phalanges. Midfoot portion16generally includes portions of footwear10corresponding with the arch area of the foot, and heel portion18corresponds with rear portions of the foot, including the calcaneus bone. Lateral side20and medial side22extend through each of portions14-18and correspond with opposite sides of footwear10. Portions14-18and sides20-22are not intended to demarcate precise areas of footwear10. Rather, portions14-18and sides20-22are intended to represent general areas of footwear10to aid in the following discussion. Portions14-18and sides20-22may also be applied to upper12specifically, or any other portion of footwear10.

As with conventional articles of footwear, sole assembly14includes an insole (not shown) located within upper12, a midsole21, and an outsole23. Midsole21and functions as the primary shock-attenuating and energy-absorbing component of footwear10.

Suitable materials for midsole21include resilient, polymer foam materials, such as polyurethane or ethylvinylacetate (EVA). Other suitable materials for midsole21will become readily apparent to those skilled in the art, given the benefit of this disclosure. Suitable materials for outsole23include traditional rubber materials. Other suitable materials for outsole23will become readily apparent to those skilled in the art, given the benefit of this disclosure.

In certain embodiments, footwear10may not include an outsole layer separate from midsole21but, rather, the outsole may comprise a bottom surface of midsole21that provides the external traction surface of sole assembly14. In certain embodiments, outsole23may be made of a plurality of separate outsole elements secured to portions of footwear10.

Unless otherwise stated, or otherwise clear from the context below, directional terms used herein, such as rearwardly, forwardly, top, bottom, inwardly, downwardly, upwardly, interior, exterior, etc., refer to directions relative to footwear10itself. Footwear10is shown inFIG. 1to be disposed substantially horizontally, as it would be positioned on a horizontal surface when worn by a wearer. However, it is to be appreciated that footwear10need not be limited to such an orientation. Thus, in the illustrated embodiment ofFIG. 1, rearwardly is toward heel portion18, that is, to the right as seen inFIG. 1. Naturally, forwardly is toward forefoot portion14, that is, to the left as seen inFIG. 1, and downwardly is toward the bottom of the page as seen inFIG. 1. Top refers to elements toward the top of the page as seen inFIG. 1, while bottom refers to elements toward the bottom of the page as seen inFIG. 1. Inwardly or interior is toward the center of footwear10, and outwardly or exterior is toward the outer peripheral edge of footwear10.

An upper plate24is secured to a lower edge of upper12. In the illustrated embodiment, upper plate24is secured about its upper peripheral edge to a lower peripheral edge of upper12with stitching26. It is to be appreciated that upper plate24may be secured to upper12with adhesive or any other suitable fastening means. Upper plate24may be formed of a fairly rigid elastomeric material, such as lightweight, durable polymer materials having a moderate flexural modulus, e.g., polyester, nylon, a polyether block copolyamide (sold as Pebax® by ATOFINA Chemicals of Philadelphia, Pa.), or thermoplastic polyurethane (TPU). Upper plate24may also be formed of a composite material that is a combination of a polymer and a plurality of fibers or particulates, such as glass or carbon fibers. Other suitable materials for upper plate24will become readily apparent to those skilled in the art, given the benefit of this disclosure.

A plurality of hollow support columns28are provided in heel portion18and extend downwardly from the lower surface of upper plate24. In certain embodiments, support columns28are co-injected with upper plate24. In other embodiments, support columns28may be bonded to upper plate24with adhesive, for example. Other suitable fastening means for securing support columns28to upper plate24will become readily apparent to those skilled in the art, given the benefit of this disclosure.

In the illustrated embodiment, four (4) support columns28are provided in heel portion18, with two support columns28being positioned on lateral side20and two support columns28being positioned on medial side22of heel portion18. In certain embodiments, support columns28are formed of transparent or translucent materials. Such materials will allow a structure positioned within a support column28to be visible from the exterior of footwear10. As seen inFIG. 4, the interior surface of support columns28substantially defines a cylinder. It is to be appreciated that the interior of support columns28may have other shapes as well.

In the illustrated embodiment, a reduced diameter, or necked portion29is formed in the exterior surface of each support column28proximate its lower end. Necked portions29serve to provide additional strength and shear resistance for support columns28, as well as enhanced aesthetics.

In certain embodiments, support columns28may be formed of an elastomeric material such as TPU. Other suitable materials for support columns28will become readily apparent to those skilled in the art, given the benefit of this disclosure.

A lower plate30extends from a rear portion of forefoot portion14of upper plate24, at a point where upper plate24extends upwardly and rearwardly providing a raised arch, rearwardly beneath upper plate24. Lower plate30extends beneath and between support columns28in heel portion18of footwear10, forming a web31between support columns28. In the illustrated embodiment, lower plate30includes a plurality of first apertures32, seen most clearly inFIG. 4, with each first aperture32exposing a central portion of the lower surface of a corresponding support column28. A second aperture34is formed in lower plate30, and is positioned in between support columns28. In certain embodiments, second aperture34is substantially diamond-shaped. It is to be appreciated that second aperture34may have any desired shape.

Lower plate30may be formed of a fairly rigid elastomeric material, such as lightweight, durable polymer materials having a moderate flexural modulus, e.g., polyester, nylon, a polyether block copolyamide (sold as Pebax™ by ATOFINA Chemicals of Philadelphia, Pa.), or thermoplastic polyurethane (TPU). Lower plate30may also be formed of a composite material that is a combination of a polymer and a plurality of fibers or particulates, such as glass or carbon fibers. Other suitable materials for upper plate24will become readily apparent to those skilled in the art, given the benefit of this disclosure.

As seen most clearly inFIG. 3, upper plate24has a plurality of apertures formed therein. As seen in the embodiment illustrated here, a plurality of first apertures36are positioned in forefoot portion14in a grid-like pattern of transverse rows35extending substantially transversely across upper plate24and longitudinal columns37extending substantially longitudinally along upper plate24. First apertures36are generally substantially rectangular in shape. The outer side of each first aperture36extending along both medial side22and lateral side20, however, are slightly angled with respect to its transverse sides, in order to more closely match the curved sides of footwear10. It is to be appreciated however, that first apertures36can have any desired shape.

A plurality of second apertures38are positioned in heel portion18of upper plate24. In the illustrated embodiment, four (4) second apertures38are positioned in heel portion18, two second apertures38being positioned on lateral side20and two second apertures38being positioned on medial side22of heel portion18. It is to be appreciated that any number of second apertures38may be positioned in heel portion18of upper plate24. Each second aperture38in heel portion18is in fluid communication with an interior of a support column28. In the illustrated embodiment, second apertures38are substantially circular. It is to be appreciated however, that second apertures38can have any desired shape.

Removable midsole21includes a plurality of projections extending downwardly from its lower surface40. A plurality of first projections42extend downwardly from forefoot portion14of midsole21, and extend downwardly through first apertures36of upper plate24, as seen inFIG. 1. In the illustrated embodiment, first projections42are generally substantially rectangular in shape. As noted above with respect to first apertures36, the outer side of each first projection42extending along both medial side22and lateral side20are slightly angled with respect to its transverse sides, in order to more closely match the curved sides of footwear10. It is to be appreciated however, that as with first apertures36, first projections42can have any desired shape.

In the illustrated embodiment, first projections42are formed in a grid pattern of transverse rows41extending substantially transversely across midsole21and longitudinal columns43extending substantially longitudinally along midsole21to match that of first apertures36. In forefoot portion14of footwear10, first projections42of midsole21have no outsole elements23and, therefore, first projections42form the ground-engaging surface of footwear10in the forefoot portion14of footwear10.

In certain embodiments, a plurality of slits44may be formed in lower surface40of midsole21. In the illustrated embodiment, a plurality of first slits44aextend substantially transversely across midsole21, with each first slit44apositioned between adjacent transverse rows35of first projections42. Similarly a plurality of second slits44bextend substantially longitudinally along midsole21, with each second slit44bpositioned between adjacent longitudinal columns37of first projections42. Slits44serve to make midsole21more flexible, thereby facilitating installing midsole within footwear10and removing it therefrom.

A plurality of second projections46extend downwardly from heel portion18of midsole21. In the illustrated embodiment, four (4) second projections46are positioned in heel portion18of midsole21, two second projections46being positioned on lateral side20and two second projections46being positioned on medial side22of heel portion18of midsole21. It is to be appreciated that any number of second projections46may be positioned in heel portion18of midsole21. Each second projection46is received in one of the hollow support columns28, as seen inFIG. 4. In the illustrated embodiment, second projections46are substantially cylindrical. It is to be appreciated however, that second projections46can have any desired shape that mates with second apertures38within which second projections46are received.

In the illustrated embodiment, each second projection46has a tab48extending downwardly from its lower surface, which is received in a recess50formed in a corresponding projection52extending downwardly from the bottom of each support column28, as seen inFIG. 4. Each projection52at the lower end of each support column28is captured in a corresponding first aperture32of lower plate30.

An outsole element23is secured to the lower surface of lower plate30beneath each support column28. Each outsole element23is substantially cylindrical with a central aperture54formed therein. Central apertures54allow visibility of support columns28and midsole21from the exterior of footwear10.

Another embodiment of a removable midsole is seen inFIG. 5, in which a midsole21ais formed such that it extends only throughout forefoot portion14of footwear10. The remainder of the midsole in such an embodiment would not be removable, and is fixed within footwear10in a conventional manner. Midsole21ahas the same configuration as that described above with respect to the forefoot portion14of midsole21, that is, it includes the plurality of first projections42that are received in first apertures36and slits44.

A further embodiment of a removable midsole is seen inFIG. 6, in which a midsole21bis formed such that it extends only throughout heel portion18of footwear10. The remainder of the midsole in such an embodiment would not be removable, and is fixed within footwear10in a conventional manner. Midsole21bhas the same configuration as that described above with respect to the heel portion18of midsole21, that is, it includes the plurality of second projections46that are received in second apertures38.

Since midsole21is removable, midsoles with different characteristics can easily be exchanged within footwear10. Thus, the performance characteristics of footwear10can be altered by replacing one midsole21with a given performance characteristic with a midsole21having a different performance characteristic. For example, midsoles21with different densities or durometers can be exchanged with one another, thereby altering the support of midsole21. By selecting a desired midsole21, the cushioning and stability of footwear10may be generally tuned to meet the specific demands of a particular activity. In general, the characteristics or properties of midsole21can be selected to accommodate various parameters, such as the specific weight of the wearer, a generally preferred degree of cushioning, a preferred degree of pronation or supination control, a particular activity, a specific ground surface, or a certain degree of motion control, for example. In addition, the footwear may be used for varying activities on ground surfaces with a wide variety of compliance characteristics. Thus, it can be appreciated that replaceable midsoles21with any desired performance characteristics can be selected and easily exchanged.

Since support columns28are translucent or transparent, second projections46of midsole21are visible from the exterior of footwear10in heel portion18of footwear10. Additionally, since first projections42extend outwardly through upper plate24and form the ground-engaging surface of footwear10in forefoot portion14, midsole21is visible from the exterior of front portion14of footwear10. Consequently, a change in the appearance of midsole21will be visible from the exterior of footwear10. Accordingly, the removability of midsoles21also allows midsoles21with different aesthetic characteristics to be easily exchanged in footwear10. For example, midsoles21of different colors can easily be exchanged in footwear10, thereby varying the aesthetic appearance of footwear10. Midsoles21with other aesthetic characteristics including texture, for example, can similarly be exchanged.

Thus, it can be seen that through the use of a removable midsole21, the aesthetic appearance and/or performance characteristics of footwear10can easily be altered by the user.

Certain embodiments of the present invention are particularly useful in systems that allow users or customers to have footwear custom-manufactured. The ability to remove and exchange midsole21is particularly suited for providing footwear that is optimized for a particular user.

U.S. patent application Ser. No. 11/420,926, filed on May 30, 2006 and entitled “Custom Ordering of an Article,” the entire disclosure of which is incorporated herein, describes a system and method with a graphical user interface for customizing an article. The system may be accessed by a user through the Internet, for example. The graphical user interface includes an analog-style selection control that allows a user to select at least one characteristic of a feature of the article. Thus, the color, density, or any other characteristic of removable midsole21could be selected with such a system.

U.S. patent application Ser. No. 09/721,445, filed on Nov. 21, 200 and entitled “Method and System for Custom Manufacturing Items Such as Footwear”, “the entire disclosure of which is incorporated herein, describes a system and method for allowing a customer to custom-order an item, such as shoes. The system and method may allow the retailer to control the selection of choices given to the customer for custom-manufacturing an item, so that the retailer can maintain some control over the appearance and/or structural components of the custom-manufactured item. The selection of a particular removable sole by the customer can be done through such a system and method.

In light of the foregoing disclosure of the invention and description of various embodiments, those skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims.