Patent Description:
Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure is secured to a lower surface of the upper and is generally positioned between the foot and the ground. In addition to attenuating ground reaction forces and absorbing energy (i.e., imparting cushioning), the sole structure may provide traction and control potentially harmful foot motion, such as over pronation. Accordingly, the upper and the sole structure operate cooperatively to provide a comfortable structure that is suited for a wide variety of ambulatory activities, such as walking and running.

Conventional sole structures can generally incorporate multiple layers that are typically referred to as an insole, a midsole, and an outsole. The insole is a thin, cushioning member located within the upper and adj acent the plantar (lower) surface of the foot to enhance footwear comfort. The midsole, which is traditionally attached to the upper along the entire length of the upper, forms the middle layer of the sole structure and serves a variety of purposes that include controlling foot motions and providing cushioning. 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.

Conventional midsoles are often formed from a resilient, polymer foam material, such as polyurethane or ethylvinylacetate, that extends throughout the length of the footwear. The properties of the polymer foam material in the midsole are primarily dependent upon factors that include the dimensional configuration of the midsole and the specific characteristics of the material selected for the polymer foam, including the density of the polymer foam material. By varying these factors throughout the midsole, the relative stiffness, degree of ground reaction force attenuation, and energy absorption properties may be altered to meet the specific demands of the activity for which the footwear is intended to be used.

<CIT> describes high heels with various detachable designs.

The invention is defined by an article of footwear as disclosed in claim <NUM>.

The following discussion and accompanying figures disclose an article of footwear <NUM> (also referred to as the article <NUM>) that includes a removable sole structure with a mechanical cushioning element (as opposed to primarily relying on foam). These designs may enable any major component of the shoe to be selectively replaced, thus extending the total life of the article. Further, enabling easy removal of the components may permit an end user to customize colorways according to their own preferences, or to achieve a particular look. In some configurations, it may be preferable to form some or all of the components out of a thermoplastic polymer or other easily recyclable material to promote a sustainable design and minimize manufacturing and/or post-consumer waste. The concepts disclosed herein may be applied to a wide range of footwear styles and should not limited to the specific embodiments discussed below and depicted in the figures.

In addition to easy component replacement, the present designs may enable new/different retail models or practices that may be more autonomous, reduce overall packaging waste, enable a greater degree of user customization, and/or reduce supply chain complexity. For example, in one configuration, one or more components of an article of footwear may be formed using a 3D printing/rapid on-demand production technique, and may be made in a custom color and size for a particular user. This would reduce the need for separate packaging, inventorying, and global distribution of that components. Likewise, in some embodiments, individual components may be offered for sale from a vending machine or other automated purchase device. Such a vending machine may be placed at a traditional retail establishment for self-service walk-up commerce, or may be placed at an event venue and stocked with limited edition color or design components to commemorate that event. Other applications of the present technology are listed below.

With reference to <FIG>, an article of footwear <NUM> is depicted that includes an upper <NUM> and a sole structure <NUM> attached to the upper <NUM>. The article of footwear <NUM> may be divided into one or more regions. The regions may include a forefoot region <NUM>, a midfoot region <NUM>, and a heel region <NUM>. The forefoot region <NUM> may correspond with toes and joints connecting metatarsal bones with phalanx bones of a foot. The midfoot region <NUM> may correspond with an arch area of the foot while the heel region <NUM> may correspond with rear portions of the foot, including a calcaneus bone. The article of footwear <NUM> may additionally include a medial side <NUM> and a lateral side <NUM> that correspond with opposite sides of the article of footwear <NUM> and extend through the regions <NUM>, <NUM>, <NUM>. The article of footwear <NUM> may generally extend between an anterior end <NUM> or anterior end portion, which may correspond to the most forward point of the forefoot region <NUM>, and a posterior end <NUM> or posterior end portion, which may correspond to the most rearward point of the heel region <NUM>. A longitudinal axis of the article of footwear may be defined as extending between the anterior end <NUM> and the posterior end <NUM>. As used herein, anatomical directional references such as anterior and posterior should be understood as referencing directions of the article of footwear that would be consistent with the ends <NUM>, <NUM> defined above and with established anatomical convention when the shoe is worn on the foot of a wearer.

The upper <NUM> includes interior surfaces that defines an interior void <NUM> that receives and secures a foot for support on the sole structure <NUM>. An ankle opening <NUM> in the heel region <NUM> may provide access to the interior void <NUM>. For example, the ankle opening <NUM> may receive a foot to secure the foot within the void <NUM> and facilitate entry and removal of the foot from and to the interior void <NUM>.

In some examples, one or more fasteners or other closure systems may extend across the upper <NUM> to adjust a fit of the interior void <NUM> around the foot while concurrently accommodating entry and removal of the foot therefrom. The fasteners or other closure systems may include laces, straps, cords, latching mechanisms, clasps, snaps, hook-and-loop, or any other suitable type of fastener.

The upper <NUM> may be formed from one or more materials that are stitched or adhesively bonded together to form the interior void <NUM>. Suitable materials of the upper <NUM> may include, textiles, foam, leather, and synthetic leather. In one embodiment, the upper <NUM> may be formed from a knit fabric to provide a more socklike feel than traditional rigid uppers. The materials may be selected and located to impart properties of durability, air-permeability, wear-resistance, flexibility, and comfort to the foot while disposed within the interior void <NUM>.

The sole structure <NUM> is attached to an underside of the upper <NUM> and provides the article of footwear <NUM> with support and cushioning during use. Namely, the sole structure <NUM> attenuates ground reaction forces caused by the article of footwear <NUM> striking the ground during use. Accordingly, and as set forth below, the sole structure <NUM> may incorporate energy absorbing design characteristics to allow the sole structure <NUM> to minimize the impact experienced by a user when wearing the article of footwear <NUM>.

Referring to <FIG>, in general, the sole structure <NUM> includes a midsole <NUM> and may include an outsole <NUM> (or one or more outsole members or inserts). As generally illustrated in <FIG>, the midsole <NUM> may extend from the anterior end <NUM> to the proximal end <NUM> of the article of footwear and may further extend beyond the anterior and proximal extremes of the upper <NUM>. Such an overextension may, for example, provide a suitable foothold to aid the wearer in removing the shoe. The midsole <NUM> is secured to a lower portion of upper <NUM> and is positioned such that it extends under the foot during bipedal use. Among other purposes, midsole <NUM> is designed to attenuate ground reaction forces and to absorb energy (i.e., impart cushioning) when the user is walking or running.

With continued reference to <FIG> an outsole <NUM> or plurality of outsole members are provided on a lower, ground-facing surface of the midsole <NUM>, and on an opposite side of the midsole <NUM> from the upper <NUM>. The outsole <NUM> may define a ground-engaging surface <NUM> that is operative to provide wear-resistance and to enhance traction between the article of footwear <NUM> and the ground. The outsole <NUM> may be formed from a resilient material such as, for example, a rubber or durable thermoplastic polyurethane, which can improve traction and durability. The ground-engaging surface <NUM> may include one or more traction elements <NUM> (as best illustrated in <FIG>) or protrusions that extend outward to provide the article of footwear <NUM> with increased traction during use.

When fully assembled, an upper surface <NUM> of the midsole <NUM> may contact and be secured against a lower, ground-facing portion <NUM> of the upper <NUM>. In one configuration, the upper surface <NUM> of the midsole may be attached to the upper <NUM> using a suitable adhesive that may establish a permanent bond between the two components. In a different configuration, however, the midsole <NUM> may be secured to the upper <NUM> by securing it to a mating sole component that is integrated into the ground-facing portion <NUM> of the upper <NUM>. For example, as shown in <FIG>, the sole structure <NUM> may further include a chassis plate <NUM> that is either slipped in the inner void <NUM> to rest against the lower surface of the upper (similar to an insole or drop-in midsole) or that is directly integrated into the upper <NUM>, similar to a strobel. It is worth noting that the order of the components in the exploded view of <FIG> is shown for illustrative convenience, and that the chassis plate <NUM> is a drop-in component that is slipped into or wholly integrated with the upper <NUM>.

While <FIG> and <FIG> schematically illustrate outsole portions <NUM> that are comparatively large and include a plurality of traction elements, in the embodiment schematically illustrated in <FIG>, the outsole <NUM> may instead include a plurality of discrete outsole portions <NUM>, with each outsole portion comprising a single traction element <NUM>.

In some configurations, the midsole <NUM> may be secured to the chassis plate <NUM> by direct attachment either through welding (e.g., fusing two thermoplastic polymers together without an intermediate adhesive) or adhering with the use of an intermediate adhesive between the components. In another configuration, such as shown in <FIG>, the sole structure <NUM> includes a plurality of threaded fasteners <NUM> that extend between and operatively secure the midsole <NUM> in a fixed position relative to the chassis plate <NUM>. By un-securing these fasteners <NUM>, the midsole <NUM> may be removable from both the chassis plate <NUM> and the upper <NUM> to facilitate easy repair or replacement of one or more components of the article of footwear <NUM>. While threaded fasteners are shown and described herein for securing the midsole <NUM> to the chassis plate <NUM>, in other embodiments, other types of fasteners may be used. For example, push-in fasteners, quarter turn locking fasteners, or other forms of removable fastening may be used.

As shown in <FIG>, the chassis plate <NUM> includes a plurality of threaded anchors <NUM> that are each adapted to receive a different one of the plurality of threaded fasteners <NUM>. When assembled, each threaded fastener <NUM> may extend through a corresponding aperture <NUM> provided in the midsole <NUM> and may be threadably engaged with a different one of the plurality of threaded anchors <NUM> to secure the midsole <NUM> to the chassis plate <NUM>. The plurality of threaded anchors <NUM> may include, for example, tapped/threaded apertures formed directly into the chassis plate <NUM>, threaded bushings that are press fit or otherwise secured within apertures in the chassis plate <NUM>, or, as shown in <FIG> hex nuts that are seated within a corresponding hexagonal aperture <NUM> in an upper surface <NUM> of the chassis plate <NUM>.

In some configurations, once assembled, the material of the upper <NUM> may extend at least partially between the chassis plate <NUM> and the upper surface <NUM> of the midsole <NUM>. The chassis plate <NUM> and the midsole <NUM> may exert a compressive force against the trapped material of the upper <NUM>, which may provide sufficient resistance to prevent and/or inhibit the upper from decoupling from the midsole <NUM>/sole structure <NUM>. In one configuration, the upper <NUM> may further include one or more reinforced eyelets or grommets on the ground-facing portion <NUM>, through which the threaded fasteners may pass when secured to the chassis plate. These eyelets/grommets may further aid in stabilizing the upper <NUM> relative to the sole structure <NUM>.

Referring to <FIG>, the article of footwear <NUM> may at least partially rely on the structural design of the midsole <NUM> to attenuate ground reaction forces during use. This structural design generally relies on the midsole <NUM> flexing on impact and rebounding as the forces dissipate. The midsole <NUM> includes an upper plate <NUM> that is integrally coupled with one or more ground-facing lower plates <NUM> to form one or more spring-like shock absorbers. As generally discussed above, the upper plate <NUM> may extend across the entire length of the upper <NUM> from at least the anterior end <NUM> to the posterior end <NUM>. Further, the upper plate <NUM> may define the plurality of apertures <NUM> through which the threaded fasteners <NUM> may pass to secure the midsole <NUM> to the upper <NUM>.

The one or more ground facing lower plates <NUM> may each have a length, measured parallel to the longitudinal axis that is less than a similarly measured length of the upper plate <NUM>. Said another way, each ground facing lower plate <NUM> may extend under only a portion of the upper plate <NUM>. As generally illustrated in <FIG>, in one configuration, the midsole <NUM> may include a first ground facing lower plate <NUM> that is substantially located within the heel region <NUM> and a second lower plate <NUM> that is substantially located within the forefoot region <NUM>.

Each ground facing lower plate <NUM>, <NUM> may have a respective central portion <NUM>, anterior end portion <NUM>, and posterior end portion <NUM>, with the central portion <NUM> being located between the anterior end portion <NUM> and the posterior end portion <NUM>. At least one of the anterior or posterior end portion <NUM>, <NUM> of each lower plate <NUM>, <NUM> may be secured to or otherwise joined to the upper plate <NUM>, while the central portion <NUM> may be spaced apart from the upper plate <NUM>. In some configurations, the midsole <NUM> may define a void <NUM> or open space between one or both of the lower plates <NUM>, <NUM> and the upper plate <NUM>. This void <NUM> may enable the respective lower plate <NUM>, <NUM> to more easily yield in response to an impact loading. As better shown in <FIG>, in one configuration, a first void <NUM> may extend between the central portion <NUM> of the first lower plate <NUM> and the upper plate <NUM> and may extend through the midsole <NUM> from the lateral side to the medial side. Further, in some configurations, a second void <NUM> may extend between the central portion <NUM> of the second lower plate <NUM> and the upper plate <NUM> and may similarly extend through the midsole <NUM> from the lateral side to the medial side.

As further illustrated, in one configuration, the first ground-facing lower plate <NUM>, provided in the heel region <NUM>, may be joined to the upper plate <NUM> via a first radiused transition <NUM> that is provided at a posterior end of the midsole <NUM>. Likewise, the second ground-facing lower plate <NUM>, provided in the forefoot region <NUM>, may be joined to the upper plate <NUM> via a second radiused transition <NUM> that is provided at an anterior end of the midsole <NUM>. In doing so, the midsole <NUM> may have an appearance where the upper plate <NUM> wraps downward at both the posterior and anterior ends to form the respective first and second lower plates <NUM>, <NUM>. In doing so, this design leaves the sidewalls substantially open to provide the respective voids <NUM>, <NUM> through the width of the midsole <NUM>. In this configuration, the upper plate <NUM>, first lower plate <NUM> and second lower plate <NUM> may all be integrally formed, such as through an injection molding, 3d printing/additive manufacturing process, or thermoforming process.

In a general sense, the present design may attenuate ground impact forces by enabling the respective lower plates <NUM>, <NUM> to elastically deform in response to an applied load. As shown in the figures, in one configuration, each lower plate may operate similar to a leaf spring - i.e., where each lower plate <NUM>, <NUM> is anchored at opposing anterior and posterior end portions <NUM>, <NUM>, and the central portion <NUM> is operative to deflect toward the upper plate <NUM> in response to an applied transverse load. In this embodiment, such as shown in <FIG>, both the anterior and posterior end portions <NUM>, <NUM> of each lower plate <NUM>, <NUM> may be integrally formed with the upper plate <NUM>. This may be accomplished, for example, using one or more molding processes, including injection molding, compression molding, and the like. Likewise, in some embodiments, this may be accomplished through a 3d printing/additive manufacturing process.

Greater travel distances in the lower plate <NUM>, <NUM>, and thus greater cushioning/force attenuation, may be provided by spacing the respective anterior and posterior end portions <NUM>, <NUM> for each lower plate <NUM>, <NUM> further apart. In one configuration, a midsole <NUM> with adequate cushioning performance may be provided though a design where the anterior end portion <NUM> of the first, heel-side lower plate <NUM> attaches to the upper plate <NUM> or otherwise terminates at a first location <NUM> that is anterior to a second location <NUM> where the posterior end portion <NUM> of the second, forefoot lower plate <NUM> attaches to the upper <NUM> or otherwise terminates. As shown in <FIG>, in one embodiment of this design, the midsole <NUM> may have a scissored appearance, where one of the two plates attaches in a central location between the medial and lateral sides <NUM>, <NUM>, and the other plate extends on opposing sides of that plate and attaches at locations that are more peripherally located. In another embodiment, one plate may attach closer to the medial side <NUM> of the upper plate <NUM>, while the other plate may attach closer to the lateral side <NUM>.

As noted above and generally illustrated in <FIG>, the midsole <NUM> is removably secured to the chassis plate <NUM> and upper <NUM> using a plurality of threaded fasteners <NUM> that each extend through a different respective hole/aperture <NUM> provided in the upper plate <NUM>. In one embodiment, to provide access to these threaded fasteners, one or more of the lower plates <NUM> may include a plurality of access apertures <NUM> extending entirely through the thickness of the lower plate <NUM>, with each access aperture <NUM> being aligned with a different one of the plurality of apertures <NUM> in the upper plate <NUM>. The access apertures <NUM> may facilitate tightening of the respective threaded fasteners <NUM> by allowing an elongate tool, such as a screwdriver, to extend through the access aperture <NUM> into contact with the fastener <NUM>.

<FIG> schematically illustrate the alignment between each of the plurality of apertures <NUM> in the upper plate <NUM> and the plurality of access apertures <NUM> in the respective lower plates <NUM>. In general, the term "aligned" in the context of the alignment of holes between the two plates, is intended to mean that each aperture is centered around a longitudinal axis of a threaded fastener as that threaded fastener is being threaded into the chassis plate <NUM> through the aperture <NUM> in the upper plate <NUM>.

In some embodiments, the midsole <NUM> may be secured to the chassis plate <NUM> in both the heel region <NUM> and in the forefoot region <NUM>. As such, the first lower plate <NUM> comprises a first plurality of access apertures <NUM>, while the second lower plate <NUM> includes a second plurality of access apertures <NUM>. As shown in <FIG>, the first plurality of access apertures <NUM> in the first lower plate <NUM> are aligned with a first subset of the plurality of apertures <NUM> in the upper plate <NUM>. Likewise, as shown in <FIG>, the second plurality of access apertures <NUM> in the second lower plate <NUM> are aligned with a second subset of the plurality of apertures <NUM> in the upper plate <NUM>. As further illustrated in <FIG>, the number of access apertures <NUM> provided in the midsole <NUM> may be less than the total number of apertures provided in the one or more lower plates <NUM>. More specifically, the midsole <NUM> may further include one or more ancillary apertures <NUM> that extend entirely through the lower plate <NUM>, though are not aligned with a corresponding aperture <NUM> in the upper plate <NUM>. In one embodiment, the total number of ancillary apertures <NUM> may be greater than the total number of access apertures <NUM>.

Referring again to <FIG>, rather than simply leaving the access apertures <NUM> and/or ancillary apertures <NUM> open, these apertures may instead be used to retain or secure the outsole <NUM> to the midsole <NUM>. For example, in one configuration, the outsole <NUM> may include a forefoot outsole portion <NUM> and a heel outsole portion <NUM>, such as shown in <FIG>. In this configuration, each of the forefoot outsole portion <NUM> and heel outsole portion <NUM> may include a plurality of posts <NUM> that extend upward into the plurality of access apertures <NUM> in the lower plate <NUM>. These posts <NUM> may be glued in place, however in a more preferable embodiment, they may simply be press fit into the holes. In one embodiment, each post <NUM> may include a retention feature <NUM> (as best seen in <FIG> and <FIG>) that protrudes to an opposing side of the lower plate <NUM> and has a diameter that is larger than a corresponding diameter of the aperture through which it extends. In this manner, the retention feature <NUM> may provide a mechanical interference that resists the post <NUM> from easily being removed from the aperture.

In the embodiment shown in <FIG>, where discrete outsole elements are used, each of the plurality of discrete outsole elements may at least partially extend into a different one of the plurality of apertures in the lower plate. For example, each discrete outsole element may include a respective post that may be press fit, adhered, or otherwise secured within a respective aperture). Similar to the embodiment shown in <FIG>, each post may include a retention feature, much like the design shown in <FIG>.

In general, the outsole described above is configured to be removable from the midsole to provide selective access to the threaded fasteners and enable a user to separate the midsole from the upper. In one configuration, the process of disassembling a fully assembled article of footwear <NUM> may begin by removing the outsole <NUM> and/or the plurality of outsole members from the apertures in the lower plate. Opening these apertures, by removing the outsole <NUM>, may then permit a tool, such as a screwdriver, hex wrench, socket driver, or the like to be inserted through the various apertures to individually engage each threaded fastener <NUM>. By rotating the tool, each threaded fastener may be removed, which may decouple the midsole from the upper.

Once apart, further disassembly of the article of footwear may be achieved, for example, by removing a sock liner or insole from the interior void of the upper. Likewise, in some configurations, the chassis plate <NUM> may also be removed from the interior void <NUM> of the upper <NUM>. Full disassembly in this manner may permit each component to be individually replaced should that component begin to show signs of wear from use.

Given the ease with which the present article of footwear <NUM> may be disassembled and individual components may be replaced, it would be preferable for each component to be capable of being recycled or reused in some manner to advance the goal of sustainable manufacturing/product design. As such, in one configuration, at least the midsole <NUM> and the chassis plate <NUM> may be substantially formed from a thermoplastic polymer that may be easily melted down and recycled. The term "substantially" is intended to contemplate that certain aperture bushings or threaded hex nuts may be formed from metal, while the main body of the component may be formed entirely from the thermoplastic polymer. Furthermore, in some designs, the outsole <NUM> may also be formed from a thermoplastic polymer, and likewise, in some designs the upper <NUM> may comprise a knit material formed from a yarn that includes a thermoplastic polymer. In some embodiments, the yarn used to form the knit upper may be entirely formed from thermoplastic polymer filament. In one configuration, each of the upper <NUM>, the chassis plate <NUM>, the midsole <NUM> and the outsole <NUM> may be substantially formed from a thermoplastic polymer material (i.e., with the exception of any threaded fasteners, retention members, or bushings used to facilitate the joining of the various components). In this manner, the present article of footwear <NUM> may be entirely recyclable while also maintaining the ability to selectively replace one or more components that are exhibiting signs of wear.

In one configuration, each of the midsole <NUM> and chassis plate <NUM> may be formed from a non-foamed polymer material or, alternatively, from a composite material containing fibers such as carbon fibers. Suitable materials may include thermoplastic polyurethane (TPU), polyamides (e.g., PA6 or PA66), or other engineering polymers. The material may include a fiber fill, such as short or long fiber glass, aramid, bamboo, or carbon fibers, or may include similar continuous fabrics. Forming the midsole <NUM> from a relatively rigid material allows the midsole <NUM> to distribute forces associated with use of the article <NUM> while also preventing the structure from collapsing on itself under the weight of the wearer. In one configuration, to prevent debris from becoming trapped within the intermediate recess/void <NUM> between the upper and lower plates <NUM>, <NUM>, a foamed thermoplastic polymer material may be provided between the plates. To facilitate access to the threaded fasteners <NUM>, the foamed thermoplastic polymer material may include through-hole apertures extending between the access apertures <NUM> in the lower plate <NUM> and the apertures <NUM> in the upper plate <NUM>.

An example of an upper construction that may be used with the present article of footwear <NUM> is described in <CIT>. The '<NUM> Application generally describes a knitted upper that has a multi-layer fabric construction that resembles a sock or "bootie. " As described, the upper may further have selective reinforcement or stiffening portions within the heel, lateral sidewall, and/or medial sidewall. These stiffened portions may be provided, for example, by incorporating thermoplastic stiffening panels between adjacent knitted layers, or by thermally treating regionally provided thermoplastic yarns within the knit to alter a material property of the fabric.

The upper <NUM> may be constructed by pulling one or more layers of tubular knit material onto a last, and then closing a toe seam, for example, using RF or ultrasonic welding techniques. In one configuration, the tubular knit material may include a plurality of thermoplastic fibers. Likewise, in some embodiments, the upper may include other features typical of a shoe, such as lace eyelets graphical embellishments, and the like. Further detail on the process for forming a strobel-less upper are explained in the '<NUM> Application mentioned above. While a strobel-less upper is preferred, in other embodiments, the upper <NUM> may be constructed in a standard manner by seaming a vamp and/or other shoe portions to a strobel.

In one embodiment, a business model suitable to commercialize the present design may include offering at least one of the components for sale separate from the remaining components. Such may be accomplished through the use of self-service vending machines, or through traditional retail means. This may permit users to customize and/or repair their article of footwear by replacing only a single component. In yet another embodiment, global supply chain systems may be greatly simplified by producing one or more of the shoe components local to the final point of sale. For example, the midsole <NUM> may be produced using an additive manufacturing process, such as fused filament fabrication at a retail site, or at a regional distribution/manufacturing center that is within a predefined local distance of the retail site. Such a model would not only simplify global supply chain logistics, but may also reduce the need for excess inventory production and storage by producing components as requested (i.e., directly by the consumer, or requested by a retailer when inventory is getting low). It may also permit a greater degree of user customization in terms of the colors, embellishments, fit, and/or cushioning/support properties.

The above features and advantages, and other features and advantages, of the present teachings are readily apparent from this detailed description of some of the best modes and other embodiments for carrying out the present teachings, as defined in the appended claims, when taken in connection with the accompanying drawings.

"A," "an," "the," "at least one," and "one or more" are used interchangeably to indicate that at least one of the item is present; a plurality of such items may be present unless the context clearly indicates otherwise. All numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term "about" whether or not "about" actually appears before the numerical value. "About" indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; about or reasonably close to the value; nearly). In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range. Each value within a range and the endpoints of a range are hereby all disclosed as separate embodiment. The terms "comprises," "comprising," "including," and "having," are inclusive and therefore specify the presence of stated items, but do not preclude the presence of other items. As used in this specification, the term "or" includes any and all combinations of one or more of the listed items. When the terms first, second, third, etc. are used to differentiate various items from each other, these designations are merely for convenience and do not limit the items.

Claim 1:
An article of footwear (<NUM>) comprising:
an upper (<NUM>) having an internal volume adapted to receive a foot of a wearer;
a sole structure (<NUM>) secured to the upper (<NUM>), the sole structure (<NUM>) including:
a chassis plate (<NUM>) provided within the upper (<NUM>);
a midsole (<NUM>) removably secured to the chassis plate (<NUM>) via plurality of fasteners extending therebetween, the midsole (<NUM>) positioned such that a portion of the upper (<NUM>) extends between the chassis plate (<NUM>) and the midsole (<NUM>); and
an outsole tread element removably attached to a ground facing surface of the midsole (<NUM>);
wherein the plurality of fasteners comprise a plurality of threaded fasteners (<NUM>) extending between and removably securing the midsole (<NUM>) with the chassis plate (<NUM>),
wherein:
the chassis plate (<NUM>) comprises a plurality of threaded anchors (<NUM>);
the midsole (<NUM>) comprises a plurality of apertures (<NUM>), each aperture (<NUM>) corresponding to a different one of the plurality of threaded anchors (<NUM>);
wherein the plurality of fasteners comprise a plurality of threaded bolts, each threaded bolt extending through a corresponding one of the plurality of apertures (<NUM>) and being threadably engaged with a different one of the plurality of threaded anchors (<NUM>) to secure the midsole (<NUM>) with the chassis plate (<NUM>);
wherein the midsole (<NUM>) comprises a mechanical cushioning structure having an upper plate (<NUM>) coupled with a lower plate (<NUM>, <NUM>, <NUM>), the upper plate (<NUM>) including the plurality of apertures (<NUM>) through which the plurality of threaded fasteners (<NUM>) extend, the lower plate (<NUM>, <NUM>, <NUM>) comprising an anterior end portion (<NUM>), a posterior end portion (<NUM>), and a central portion (<NUM>) disposed between the anterior end portion (<NUM>) and the posterior end portion (<NUM>); and
wherein:
the central portion (<NUM>) of the lower plate (<NUM>, <NUM>, <NUM>) is spaced apart from the upper plate (<NUM>);
at least one of the anterior end portion (<NUM>) or the posterior end portion (<NUM>) of the lower plate (<NUM>, <NUM>, <NUM>) is secured to the upper plate (<NUM>); and
the outsole tread element is secured to the lower plate (<NUM>, <NUM>, <NUM>).