Article of footwear and method of manufacturing an article of footwear

A sole structure for an article of footwear includes a unitary cushioning component comprising a plurality of scrap foam pieces configured as a plurality of different polyhedron shapes and a resin binder securing the scrap foam pieces to one another. The sole structure may comprise a midsole including an outer shell defining a central cavity. The cushioning component may be disposed in the central cavity as a core of the midsole. A method of manufacturing an article of footwear cutting the scrap foam body into pieces, mixing the pieces with a resin binder, and compression molding the mixed pieces and resin binder in a mold to form a cushioning component of a sole structure of the article of footwear.

TECHNICAL FIELD

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

BACKGROUND

Footwear often includes many components of many different materials. An article of footwear typically includes a sole structure configured to be located under a wearer's foot to space the foot away from the ground. Sole structures in athletic footwear are typically configured to provide cushioning, motion control, and/or resilience. Footwear manufacturing strives to provide high quality, durable footwear in an environmentally conscience manner.

DESCRIPTION

The present disclosure generally relates to an article of footwear and to a method of manufacturing the article of footwear that may include using scrap foam for at least one cushioning component. Stated differently, a scrap foam body from a first footwear application can be utilized in a second footwear application to reduce waste. The scrap foam pieces may result from cutting one or more scrap foam bodies. More specifically, in an aspect of the disclosure, the sole structure may include a cushioning component comprised of a plurality of scrap foam pieces and a resin binder securing the pieces to one another. The cushioning component may consist of only the scrap foam pieces, the resin binder, and in some implementations, dye added to the binder. No foaming agents, virgin foam material, or other additives are included in the cushioning component. Most scrap foam bodies may be recycled under the method as the initial shape of the scrap foam body is largely irrelevant given that it is cut into smaller pieces when utilized in the second footwear application, such as by chopping the scrap foam body into chopped pieces. Because the scrap foam body is cut, a majority of the scrap foam pieces may be configured as a plurality of different polyhedron shapes. For example, cutting blades may impart relatively straight faces on the pieces as well as angles between faces of the pieces, resulting in mostly polyhedron-shaped pieces. As a series of cutting operations may be employed, the pieces may have different sizes and different polyhedron shapes. The scrap foam body is thus not wasted but is reused as a cushioning component of a footwear sole structure, such as a midsole component. The cut pieces of different polyhedron shapes provide a more even (e.g., smoother) outer surface having denser edges and greater surface area than would a plurality of torn or crushed pieces of similar sizes, for example. A relatively smooth outer surface may provide greater comfort at the foot-facing surface as well as denser edges for structural stability of the cushioning component. Additionally, a relatively smooth outer surface may provide better bonding surfaces for the outer shell described herein.

In one example, a dye may be mixed in the resin binder prior to mixing the pieces of the scrap foam body with the resin binder. In one or more embodiments, the scrap foam pieces comprise Pebax® thermoplastic elastomer foam, and the resin binder comprises polyurethane. It should be appreciated however, that other materials may be used for the scrap foam pieces and/or for the resin binder within the scope of the present disclosure.

The cushioning component may be a midsole core, and the sole structure may further comprise an additional cushioning component configured as an outer shell defining a central cavity. The midsole core may be disposed in the central cavity as a core of the midsole. The outer shell thus at least partially surrounds the midsole core, and acts as a protective cage to shield the midsole core around its periphery. For example, the outer shell may comprise a lateral shell body extending along a lateral side of the midsole core and a medial shell body extending along a medial side of the midsole core. The lateral shell body may be coupled to the medial shell body forward of the midsole core and rearward of the midsole core. For example, each shell body may have longitudinally-extending bonding surfaces. The midsole core may be a first foam material, and the outer shell may be a second foam material different than the first foam material. For example, the midsole core may be Pebax® and the outer shell may be Phylon.

The central cavity defined by the outer shell may be a through hole and an upper surface and a lower surface of the midsole core may be exposed in the central cavity. Additionally, the upper surface of the midsole core may be flush with the lateral shell body and the medial shell body, the lower surface of the midsole core may be flush with the lateral shell body and the medial shell body, or both the upper surface and the lower surface of the midsole core may be flush with the lateral shell body and the medial shell body. Additionally, at least one of the medial shell body or the lateral shell body may have an inner side and an outer side, and at least one through hole extending from the inner side to the outer side with the midsole core extending across the through hole at the inner side.

In an aspect, the lateral shell body and the medial shell body may each have an inner rim extending inward into the cavity. The midsole core may interfit with the lateral side body and the medial side body at the inner rim so that the inner rim rests on the midsole core. The inner rim may be at the front and/or at the rear of each of the lateral shell body and the medial shell body. A notch in the midsole core may interfit with the inner rim. The inner rim and the notch may be referred to as complementary locating features that help in properly aligning the shell bodies and the midsole core during assembly.

The lateral shell body may have a bonding surface forward of the midsole core, and the medial shell body may have a bonding surface forward of the midsole core contiguous with and coupled to the bonding surface of the lateral shell body that is forward of the midsole core. The bonding surfaces may be bonded to one another, such as by applying adhesive on the bonding surfaces and then placing the bonding surfaces into contact with one another. In one aspect, applying adhesive may include applying primer and then applying cement to the bonding surfaces.

Similarly, the lateral shell body may have a bonding surface rearward of the core, and the medial shell body may have a bonding surface rearward of the core contiguous with and coupled to the bonding surface of the lateral shell body that is rearward of the midsole core. The bonding surfaces may extend in a longitudinal direction of the article of footwear and may be planar.

In an aspect, the sole structure may include an outsole extending across and secured to a lower surface of the midsole core, to a lower surface of the lateral shell body, and to a lower surface of the medial shell body. In one or more embodiments, the outsole may be at least partially transparent, so that the lateral shell body, the midsole core, and the medial shell body may be viewed through the outsole.

In some embodiments, a heel counter may be secured to an upper surface of the lateral shell body and to an upper surface of the medial shell body in a heel region of the article of footwear. The heel counter may also be secured to the upper of the article of footwear, such as to an exterior surface of the upper around a rear of the heel portion of the upper.

In another aspect, an article of footwear may comprise a midsole including a first cushioning component configured as a midsole core and a second cushioning component configured as an outer shell defining a central cavity. The midsole core may be disposed in the central cavity with the outer shell bordering a lateral side and a medial side of the midsole core and defining a plurality of through holes exposing the lateral side and the medial side of the midsole core. The midsole core may or may not comprise cut scrap foam pieces as discussed above.

A method of manufacturing an article of footwear may comprise receiving a scrap foam body, cutting the scrap foam body into pieces, and mixing the pieces with a resin binder to form a mixture. The method may further include compression molding the mixture in a mold to form a cushioning component of a sole structure of the article of footwear. Due to the cutting, the pieces may be configured as a plurality of polyhedrons of different shapes as discussed herein. The pieces retain their polyhedron shapes in the cushioning component as assembled in the finished article of footwear (except as may be slightly reshaped to conform to a mold in which they are compression molded) and are not ground, melted, pelletized or otherwise processed in a manner that changes their cut polyhedron shapes under the method disclosed herein.

In an aspect, the method may comprise drying the mixture and pouring the mixture into the mold prior to compression molding the mixture in the mold. In another aspect, the method may include adding dye to the resin binder prior to mixing the pieces with the resin binder. Accordingly, the cushioning component made from the mixture of pieces scrap foam body and resin binder can be dyed to a desired color.

In another aspect, the cushioning component may be a midsole core, and the method of manufacturing may further comprise bonding a medial shell body to a medial side of the midsole core and a lateral shell body to a lateral side of the midsole core so that the medial shell body and the lateral shell body form an outer shell defining a central cavity with the midsole core disposed in the central cavity. Bonding the medial shell body to the medial side of the midsole core may include applying adhesive to the medial shell body, applying adhesive to the medial side of the midsole core, and pressing the medial shell body against the medial side of the midsole core. Similarly, bonding the lateral shell body to the lateral side of the midsole core may include applying adhesive to the lateral shell body, applying adhesive to the lateral side of the midsole core, and pressing the lateral shell body against the lateral side of the midsole core. Applying adhesive may include applying primer and applying cement.

In an aspect, the method of manufacturing may further comprise, prior to pressing the medial shell body against the medial side of the midsole core and pressing the lateral shell body against the lateral side of the midsole core, aligning the medial shell body and the lateral shell body with the midsole core by mating an alignment feature of the medial shell body and an alignment feature of the lateral shell body with a complementary alignment feature of the midsole core.

Additionally, the method of manufacturing the article of footwear may further comprise bonding an outsole to a lower surface of the midsole core, to a lower surface of the lateral shell body, and to a lower surface of the medial shell body. Still further, the method of manufacturing may further comprise bonding a heel counter to an upper surface of the lateral shell body and to an upper surface of the medial shell body in a heel region of the article of footwear.

The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the modes for carrying out the present teachings when taken in connection with the accompanying drawings.

Referring to the drawings, wherein like reference numbers refer to like components throughout the views,FIG.1is a lateral side view of an article of footwear10that has a sole structure12and an upper14secured to the sole structure12. The upper14forms a foot-receiving cavity16configured to receive a foot. The upper14may be a variety of materials, such as leather, textiles, polymers, cotton, foam, composites, etc., and is shown with a lace15for tightening the upper14around a foot.

The footwear10illustrated herein is depicted as an athletic shoe configured for sports or for wear as a leisure shoe, but the footwear10is not limited to athletic or leisure shoes. The footwear10including its components described herein may be an athletic shoe, a leisure shoe, a dress shoe, a work shoe, a sandal, a slipper, a boot, or any other category of footwear. As indicated inFIG.1, the footwear10may be divided into a forefoot region18, a midfoot region20, and a heel region22, which are also the forefoot region, the midfoot region, and the heel region, respectively, of the sole structure12and the upper14. The forefoot region18generally includes portions of the article of footwear10corresponding with the toes and the joints connecting the metatarsals with the phalanges. The midfoot region20generally includes portions of the article of footwear10corresponding with the arch area and instep of the foot, and the heel region22corresponds with rear portions of the foot, including the calcaneus bone. The forefoot region18, the midfoot region20, and the heel region22are not intended to demarcate precise areas of the footwear10but are instead intended to represent general areas of the footwear10to aid in the following discussion.

The sole structure12includes a midsole24and an outsole26. An insole (not shown) may rest on the sole structure12in the foot-receiving cavity16. The midsole24attenuates ground reaction forces (e.g., provides cushioning) when compressed between the foot and the ground during walking, running, or other ambulatory activities. The midsole24includes multiple components integrated as a unit and is described in greater detail with respect toFIG.2. The outsole26establishes the ground-engaging surface of the article of footwear10and may be one-piece or may be several discrete outsole components. In one example, the outsole26may be formed from a wear-resistant material that may be textured to impart traction. For example, the outsole26may comprise a natural or synthetic rubber.

When the foot is positioned within the foot-receiving cavity16of the footwear10, it is supported on a foot-facing surface of the midsole24. The foot-facing surface of the midsole24may be covered by a strobel (not shown) secured to a lower region of the upper14. Also, an insole (not shown) may rest on the strobel or directly on the sole structure12in embodiments without a strobel, in which case the foot is supported by both the sole structure12and the insole.

FIG.2is a perspective view of the sole structure12including the midsole24and a heel counter32. The midsole24includes a unitary cushioning component, referred to herein as a midsole core34, that is comprised of cut pieces36of a scrap foam body38(shown inFIG.22) coated with a resin binder40that secures the pieces36to one another. The cut pieces36result from a cutting the scrap foam body38as described herein, a process that may also be referred to as chopping. Accordingly, the pieces36may be referred to as either cut pieces or chopped pieces. Additionally, a dye may be mixed in the resin binder prior to mixing the chopped pieces36with the resin binder40. In a non-limiting example, the scrap foam body38(and, therefore, the cut pieces36) comprises Pebax® thermoplastic elastomer foam and may be sold under the tradename ZoomX by Nike, Inc. The resin binder40may comprise a water-based polyurethane dispersion. The scrap foam body38, the resulting pieces36, and the resin binder40may be other materials than these within the scope of the disclosure.

The scrap foam body38shown inFIG.22is what remains of a sheet of foam after a plurality of one-piece midsole layers used in a first footwear application (e.g., for other articles of footwear of a different configuration than article of footwear10) are cut out leaving behind a plurality of recesses or apertures38A and remaining material38B surrounding the recesses or apertures38A. The sheet of foam may initially have a generally uniform thickness T. The remaining material38B of the sheet may also be split to reduce the thickness prior to a cutting process that results in the pieces. Accordingly, when the remainder38B is cut, at least the thickness dimension of a majority of the chopped pieces36may be substantially uniform. If the cutting process is controlled to provide width and length dimensions of most cut pieces36within predetermined dimensions, the resulting volume of most individual chopped pieces will be within a predetermined range of volumes. The cutting process may subject the scrap foam body38to a series of passes through cutting machine(s) having straight cutting blades disposed at different angles relative to the direction of movement of the blades. Additionally, the pieces36may be disposed in different orientations on a conveyor as they pass through the cutting machine(s), creating three dimensional pieces having a plurality of different polyhedron shapes. For example, at least some if not a majority of the pieces will have flat faces resulting from a plane of cutting of the cutting blade through the remainder38B, a subsequent cutting of a first stage of pieces, a still subsequent cutting of a second stage of pieces, etc. These pieces36thus have a plurality of different polyhedron shapes as best shown, for example, inFIGS.3,8-13, and23-24. The cut pieces of different polyhedron shapes provide a more even (e.g., smoother) outer surface having denser edges and greater surface area than would a plurality of torn or crushed pieces of similar sizes, for example. A relatively smooth outer surface may provide greater comfort at the foot-facing surface as well as denser edges for structural stability of the midsole core34. Additionally, a relatively smooth outer surface may provide better bonding surfaces for the outer shell60,62.

In addition to the midsole core34, the midsole24includes an additional cushioning component configured as an outer shell60,62that defines a central cavity44(best shown inFIGS.14and15) with the midsole core34disposed in and filling the central cavity44as shown inFIG.2. The midsole core34is bonded to the outer shell60,62and includes complementary locating features46A,46B (best shown inFIG.3) that help in properly aligning the midsole core34to the outer shell60,62during assembly. More specifically, the midsole core34has a front outer ledge46A in the forefoot region18and a rear outer ledge46B in the heel region22. The ledges46A and46B are defined by a front notch48A and a rear notch48B between the upper surface50and the side surface52of the midsole core34. The notches48A,48B and the accompanying ledges46A,46B each extend around a portion of the perimeter of the midsole core34. The front notch48A and the front outer ledge46A extend partially around the perimeter at a forward extent54of the midsole core34from the lateral side28to the medial side30. Similarly, the rear notch48B and the rear outer ledge46B extend partially around the perimeter at a rear extent56from the lateral side28to the medial side30. The midsole core34is shown inFIG.3as formed after the mixture of chopped pieces36, resin binder40and dye, if used, is mixed, dried, and compression molded.

The outer shell60,62includes a lateral shell body60and a medial shell body62bonded to one another forward of and rearward of the midsole core34. The lateral shell body60and the medial shell body62may each be formed by compression molding of injection molded phylon preforms. The lateral shell body60extends along the lateral side28of the midsole core34(e.g., along the lateral side surface71) as shown inFIG.4. The medial shell body62extends along the medial side30of the midsole core34(e.g., along the medial side surface76) as shown inFIG.5. The upper surface50of the midsole core34is flush with an upper surface61of the lateral shell body60and with an upper surface63of the medial shell body62as shown inFIGS.2and9-13, for example. Similarly, a lower surface70of the midsole core34is flush with a lower surface72of the lateral shell body60where the surfaces70,72meet, and with a lower surface74of the medial shell body62where the surfaces70,74meet as shown inFIGS.9-13, for example. In other embodiments, only the upper surface50is flush with the upper surface61,62and the lower surface70is not flush with the lower surfaces72,74, or only the lower surface70is flush with the lower surfaces72,74and the upper surface50is not flush with the upper surfaces61,62. Similarly, a lower surface70of the midsole core34is flush with a lower surface72of the lateral shell body60where the surfaces70,72meet, and with a lower surface74of the medial shell body62

As shown inFIGS.4and5, each of the lateral shell body60and the medial shell body62defines a plurality of through holes64A,64B, respectively, extending entirely through the shell bodies60,62. More specifically, the through holes64A in the lateral shell body60extend from an outer side66of the lateral shell body60to an inner side68of the lateral shell body60, best shown inFIGS.11and14. A lateral side surface71of the midsole core34extends across the through holes64A at the inner side68. Similarly, the through holes64B in the medial shell body62extend from an outer side75of the medial shell body62to an inner side77of the medial shell body62, best shown inFIGS.11and14. A medial side wall76of the midsole core34extends across the through holes64B at the inner side77. The lateral side wall71and the medial side wall76of the midsole core34are exposed and viewable from an exterior of the sole structure12at the through holes64A,64B, respectively. The through holes64A,64B reduce the overall weight of the shell bodies60,62. Additionally, the compressibility of the shell bodies60,62is increased at those areas extending over a through hole64A or64B.

The lateral and medial shell bodies60,62and the midsole core34have complementary locating features that help in properly aligning the shell bodies60,62and the midsole core34during assembly. For example, as shown inFIGS.14-15and18-19, the lateral shell body60has an inner rim86A extending inward into the central cavity44at a rear of the cavity44and an inner rim86B extending inward into the cavity44at a front of the cavity44. As shown inFIGS.9and14-17, the medial shell body62has an inner rim88A extending inward into the cavity44at the rear of the cavity44and an inner rim88B extending inward into the cavity at the front of the cavity44. The midsole core34interfits with the lateral shell body60and the medial shell body62at the inner rims86A,86B,88A, and88B so that the inner rims rests on and are bonded to the ledges46A,46B of the midsole core34. More specifically, the inner rims86A,88A fit into the notch48B and overlay and are contiguous with the rear outer ledge46B. The inner rims86B,88B fit into the notch48A and overlay and are contiguous with the front outer ledge46A. The inner rims86A,86B,88A,88B and the notches48A,48B may be referred to as complementary locating features.

The lateral shell body60may be coupled to the medial shell body62forward of the midsole core34as shown inFIG.2and rearward of the midsole core34as best shown inFIG.6. More specifically, the lateral shell body60and the medial shell body62may be coupled to one another at bonding surfaces when they are coupled to the side walls71,76of the midsole core34. For example, as shown inFIG.16, the medial shell body62has a front bonding surface90A that is disposed forward of the central cavity44and thus forward of the midsole core34when the medial shell body62is assembled to the midsole core34. The medial shell body62has a rear bonding surface90B that is disposed rearward of the central cavity44and thus rearward of the midsole core34when the medial shell body62is assembled to the midsole core34. As shown inFIG.18, the lateral shell body60has a front bonding surface92A that is disposed forward of the central cavity44and thus forward of the midsole core34when the lateral shell body60is assembled to the midsole core34. The lateral shell body60has a rear bonding surface92B that is disposed rearward of the central cavity44and thus rearward of the midsole core34when the lateral shell body60is assembled to the midsole core34. The bonding surfaces90A,90B and/or92A,92B may extend in the longitudinal direction of the article of footwear10(e.g., along or parallel with the longitudinal midline LM).

The bonding surface90A is continuous with and coupled to the bonding surface92A forward of the midsole core34, and the bonding surface92A is contiguous with and coupled to the bonding surface92B rearward of the midsole core34in the assembled article of footwear10. The bonding surfaces90A,90B and92A,92B may be planar as shown, and may be bonded to one another, such as by applying adhesive (e.g., primer and cement) on the bonding surfaces and then placing the bonding surfaces into contact with one another. For example, primer and cement may first be applied to the side walls71,76of the midsole core34, and to the outer ledges46A,46B. Primer and cement may be applied to the inner sides68,77of the lateral and medial shell bodies60,62and to the bonding surfaces90A,90B,92A,92B. The midsole core34may then be aligned with the lateral shell body60by fitting the inner rim86A to the rear outer ledge46B and the inner rim86B to the front outer ledge46A. The abutting surfaces will be contiguous with and bond to one another. The medial shell body62may then be aligned with and fit to the medial side wall76of the midsole core34by fitting the inner rim88A to the rear outer ledge46B and the inner rim88B to the front outer ledge46A. The bonding surface92A will abut and bond to the bonding surface90A, and the bonding surface92B will abut and bond with the bonding surface90B.

The heel counter32may be an injection molded polymer.FIGS.4and5show the heel counter32secured to the upper surface61of the lateral shell body60and the upper surface63of the medial shell body62so that the heel counter32is disposed in the heel region22of the article of footwear10as shown inFIG.1. For example, the heel counter32may be bonded to the upper surfaces61,63with primer and cement.FIGS.9and14,16, and18show that the upper surfaces61,63are configured with slight recesses78,80that serve as locating features to accurately position the heel counter32on the surface61,63. Lower portions of the recess78in the upper surface61and the recess80of the upper surface63together receive a lower flange82of the heel counter32(best shown inFIG.21) so that the forward ends82A,82B of the lower flange82are at forward ends78A,80A (seeFIG.14) of the recesses78,80, respectively. The recesses78,80have surrounding side walls81,83respectively that outwardly surround the lower flange82. The recess78has a side wall85A, the recess80has a side wall85B, and each recess has a portion of a rear wall85C that together surround an outer peripheral edge of the heel counter32to help properly locate the heel counter32on the upper surfaces61,63. More specifically, a lateral outer peripheral edge87A abuts the side wall85A of the heel counter32, a medial outer peripheral edge87B abuts the side wall85B of the heel counter32, and a rear edge87C abuts the rear walls85C of the heel counter32.

FIG.6andFIGS.10-13, for example, show the outsole26extending across and secured to the lower surface70of the midsole core34, the lower surface72of the lateral shell body60, and the lower surface74of the medial shell body62. For example, the outsole26may be bonded to (e.g., adhered to) the lower surfaces70,72,74with primer and cement. The outsole26may be at least partially transparent, so that the lateral shell body60, the midsole core34, and the medial shell body62may be viewed through the outsole26. Any suitable standardized test may be used to determine transparency, such as American Society for Testing and Materials (ASTM) Standard D1003-00, Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics. The outsole26also extends over a front surface of the lateral shell body60and the medial shell body62as shown inFIG.7.FIG.8shows the outsole26including several integrally-formed lugs26A,26B, only some of which are labelled. The midsole core34including its discrete, chopped foam body pieces36is shown as visible through the transparent outsole inFIG.8.

FIGS.25A and25Bare a flowchart of one example of a method200of manufacturing an article of footwear such as the article of footwear10. The steps are shown in chronological order, although another order may be possible. The circled A shows where the steps shown inFIG.25Bcontinue from those shown inFIG.25A.

The method200may comprise step202, receiving a scrap foam body such as the scrap foam body38ofFIG.22. For example, the scrap foam may be Pebax® foam in the form of a sheet from which a plurality of midsole layers used for other articles of footwear of a different configuration than article of footwear10have already been cut or otherwise removed. The method200is not limited to the use of Pebax® foam. Most scrap foam bodies may be recycled under the method200as the initial shape of the scrap foam body is largely irrelevant after it is subjected to potential splitting and to the cutting process (e.g., chopping process) described herein. The scrap foam body38is thus not wasted but is reused as a cushioning component of a footwear sole structure, such as a midsole component

The method200then proceeds with step204, cutting the scrap foam body38into pieces36. Cutting the scrap foam body38into pieces36may be by chopping the scrapped foam body38such that the pieces36are chopped pieces. If the scrap foam body38is in sheet form, step204may first include a sub-step of splitting the scrap foam body38to a thickness in the Z direction of about 10 mm (e.g., from about 8 mm to about 12 mm). Step204may include sub-steps of multiple passes through one or more chopping machines. For example, the scrap foam body38(or bodies if split) may be placed through a chopping machine for a first pass with vertical cuts, and then placed again through a chopping machine for a second pass with vertical cuts, then a third time through a chopping machine that provides random cuts with blades at various angles. The cutting process of step204is selected to result in pieces36configured with a plurality of different polyhedron shapes and of sizes within a target range of lengths, widths, and heights between 5 mm and 40 mm to account for more than 99 percent of the original scrap foam body38as usable chopped pieces36. Some of the pieces36resulting from this process are about 10 mm cubes. Pieces of this size result in fewer and smaller voids on the surface of the completed midsole core34than do larger pieces, resulting in a more even surface and denser edges of the completed midsole core34(for comfort at the foot-facing surface, for structural stability at the edges, and for adequate bonding surfaces for the outer shell60,62). In some examples, the scrap foam body38may be divided into pieces in some other manner than by cutting in step204, such as by crumbling or tearing the scrap foam body38. However, cutting the scrap foam body38into cut pieces36by the use of a cutting machine can achieve the target sizes with greater accuracy than if other methods of dividing the scrap foam body38(e.g., crumbling or tearing) were used. Additionally, the polyhedron-shaped pieces36retain their shapes after step204. For example, they are not melted into pellets, ground, re-foamed, etc.

The method200may include step208, mixing dye with a resin binder40to provide a desired color of the resin binder40. Alternatively, resin binder40without colored dye may be used, in which case the method proceeds from step204(with possible sub-step206) to step210.

In step210, the cut pieces36are mixed with the resin binder40(dyed or undyed) to form a mixture. A ratio of the chopped pieces36to the resin binder40(or resin binder40and dye mixture) may be 1:1.5 (e.g., 1 part cut pieces36to 1.5 parts resin binder40(or resin binder40and dye mixture)) may be placed in a mixing container which is then placed inside of a mixing machine and mixed sufficiently to coat all outer surfaces of the cut pieces36with the resin binder40. For example, a mixing time of 5 to 6 minutes for a 20-liter volume in a commercial mixer may be implemented.FIG.23shows pieces36and dyed resin40in a mixture held in a mixing container98prior to being completely mixed.

After mixing in step210, the method200may proceed to step212, drying the mixture. For example, the resin-coated cut pieces36may be dried until only solid resin40remains coating the outer surfaces of the cut pieces36. The resin binder-coated cut pieces36may be removed from the mixer and placed in a dryer for 30 minutes at 80 degrees Celsius, for example.FIG.24shows one example cut piece36having a polyhedron shape, coated with resin40, and after drying.

Once dried, the method200moves to step214, weighing an amount of the resin-coated pieces to provide a predetermined weight and then, step216, pouring the weighed mixture of pieces36coated with resin40(now in a dried state) into a compression mold that together will compress the mixture to provide a midsole core34with the shape and dimensions ofFIG.2. For example, the weighed amount may be poured into a bottom portion of the mold. Next, in step218, the mold may be closed by closing a top portion to provide a compression ratio of the resin-coated pieces36of about 150 to 160%.

In step220, the mold may be heated to about 163 degrees Celsius and then in step222cooled to below 30 degrees Celsius. In step224, the mold is opened, in step226, the midsole core34is removed from the mold, and in step228, the midsole core34is trimmed to remove any flash. Notably, the pieces36retain their shapes through the subsequent steps after the cutting step204(e.g., through the drying, heating, and cooling steps, etc.) so that the completed midsole core as disposed in the finished article of footwear10is comprised of foam pieces36that are randomly disposed, have different polyhedron shapes, and may be within a target range of dimensions as determined by the spacing of cutting blades in the cutting step204.

The lateral shell body60and the medial shell body62used in the sole structure12may be obtained already in a formed state (e.g., may be formed by a different entity) or may be formed by the entity carrying out the method200. Accordingly, if formed by the entity carrying out the method200, then the method200may include injection molding a preform of each of the medial shell body62and the lateral shell body60in a respective heated mold for a predetermined amount of time in step230, and then compression molding the preforms to provide the medial shell body62and the lateral shell body60in step232. Step232may include sub-steps of heating and cooling while in the mold, then trimming, washing, and drying after removal from the mold. In an example, the medial shell body62and the lateral shell body60comprise Phylon.

The method may include step234, bonding the medial shell body62and the lateral shell body60to the midsole core34by stock-fitting (e.g., manually assembling) the components. Step234may include sub-step236, applying adhesive to the medial shell body62, applying adhesive to the medial side of the midsole core34, such as from the forward extent54, along the medial side wall76, to the rear extent56. Similarly, sub-step236may include applying adhesive to the lateral shell body60, and applying adhesive to the lateral side of the midsole core34, such as from the forward extent54, along the lateral side wall71, to the rear extent56. Applying adhesive in sub-step236may include applying primer and applying cement, for example.

Next, step234may include sub-step238, aligning the medial shell body62with the midsole core34by mating an alignment feature of the medial shell body62(e.g., the inner rims88A,88B) with a complementary alignment feature of the midsole core34(e.g., the rear notch48B mates with the rear inner rim88A and the front notch48A mates with the front inner rim88B so that the rim88A rests on the rear outer ledge46B and the rim88B rests on the front outer ledge46A). Once aligning is complete, the method200moves to step240, pressing the medial shell body62against the medial side of the midsole core34. In step242, the lateral shell body60is aligned with the midsole core34by mating an alignment feature of the lateral shell body60(e.g., the inner rims86A,86B) with a complementary alignment feature of the midsole core34(e.g., the rear notch48B mates with the rear inner rim86A and the front notch48A mates with the front inner rim86B so that the rim86A rests on the rear outer ledge46B and the rim86B rests on the front outer ledge46A). In step244, the lateral shell body60is pressed against the lateral side of the midsole core34.

Accordingly, in step234, the inner side77of the medial shell body62bonds to the medial side wall76of the midsole core34and to the ledges46A,46B, the inner side68of the lateral shell body60bonds to the lateral side wall71of the midsole core34and to the ledges46A,46B, and the laterally-extending bonding surfaces92A,92B bond to the bonding surfaces90A,90B.

The step234may be referred to as stock-fitting the shell bodies60,62to the midsole core34as the assembly and pressing is done manually. After stock-fitting the components to one another, the method200may move to step246, in which the outer shell60,62and the midsole core34to which the outer shell60,62is bonded are further compressed by machine, such as in a deep well press, to ensure secure bonding.

After step246, and after the outer shell60,62and midsole core34are removed from the machine press in step248, the method200may further comprise step250, bonding an outsole26to a lower surface70of the midsole core34, to a lower surface72of the lateral shell body60, and to a lower surface74of the medial shell body62.

Still further, the method200may include step252, bonding the heel counter32to the upper surface61of the lateral shell body60and to the upper surface63of the medial shell body62in the heel region22.

Additional steps of the method200may include assembling various components of the upper14by stitching, adhesive, and heat bonding, etc. Alternatively, the upper14may be assembled by a different entity so that it is ready for lasting and/or securement to a strobel. In step254, the upper14may be secured to the sole structure12and to the heel counter32. This may include various sub-steps such as securing a strobel to the upper14on a last, and applying adhesive (e.g., primer and cement) to the strobel and to the heel counter32, and pressing the upper surface50of the midsole core34and the upper surfaces61,63of the outer shell60,62against the strobel and the heel counter32against the rear of the upper14in the heel region22.

Accordingly, the method of manufacturing200an article of footwear10disclosed herein results in a unique insole with a midsole core and an outer shell. The method of manufacturing200may increase the environmental sustainability of footwear manufacturing by utilize scrap foam as discussed herein.

The following Clauses provide example configurations of an article of footwear disclosed herein.

Clause 1. A method of manufacturing an article of footwear, the method of manufacturing comprising: receiving a scrap foam body; cutting the scrap foam body into pieces; mixing the pieces with a resin binder to form a mixture; and compression molding the mixture in a mold to form a cushioning component of a sole structure of the article of footwear.

Clause 2. The method of manufacturing of clause 1, further comprising: prior to compression molding the mixture in the mold:drying the mixture; and pouring the mixture into a mold.

Clause 3. The method of manufacturing of any of clauses 1-2, further comprising: prior to mixing the pieces with the resin binder, adding dye to the mixture.

Clause 4. The method of manufacturing of any of clauses 1-3, wherein the cushioning component is a midsole core, and the method further comprising: bonding a medial shell body to a medial side of the midsole core and a lateral shell body to a lateral side of the midsole core so that the medial shell body and the lateral shell body form an outer shell defining a central cavity with the midsole core disposed in the central cavity.

Clause 5. The method of manufacturing of clause 4, wherein bonding the medial shell body to the medial side of the midsole core includes applying adhesive to the medial shell body and applying adhesive to the medial side of the midsole core and pressing the medial shell body against the medial side of the midsole core; wherein bonding the lateral shell body to the lateral side of the midsole core includes applying adhesive to the lateral shell body and applying adhesive to the lateral side of the midsole core and pressing the lateral shell body against the lateral side of the midsole core.

Clause 6. The method of manufacturing of any of clauses 4-5, further comprising: prior to pressing the medial shell body against the medial side of the midsole core and pressing the lateral shell body against the lateral side of the midsole core, aligning the medial shell body and the lateral shell body with the midsole core by mating an alignment feature of the medial shell body and an alignment feature of the lateral shell body with a complementary alignment feature of the midsole core.

Clause 7. The method of manufacturing of any of clauses 4-6, further comprising: bonding an outsole to a lower surface of the midsole core, to a lower surface of the lateral shell body, and to a lower surface of the medial shell body.

Clause 8. The method of manufacturing of any of clauses 4-7, further comprising: bonding a heel counter to an upper surface of the lateral shell body and to an upper surface of the medial shell body in a heel region of the article of footwear.

Clause 9. An article of footwear comprising: a sole structure including a unitary cushioning component comprising a plurality of scrap foam pieces configured as a plurality of different polyhedron shapes and a resin binder securing the scrap foam pieces to one another.

Clause 10. The article of footwear of clause 9, wherein the cushioning component is a midsole core, the sole structure further includes an additional cushioning component configured as an outer shell defining a central cavity, and the midsole core is disposed in the central cavity.

Clause 11. The article of footwear of clause 10, wherein the outer shell comprises: a lateral shell body extending along a lateral side of the midsole core; a medial shell body extending along a medial side of the midsole core; and wherein the lateral shell body is coupled to the medial shell body forward of the midsole core and rearward of the midsole core.

Clause 12. The article of footwear of clause 11, wherein the central cavity is a through hole and an upper surface and a lower surface of the midsole core are exposed in the central cavity.

Clause 13. The article of footwear of clause 12, wherein the upper surface of the midsole core is flush with the lateral shell body and the medial shell body, the lower surface of the midsole core is flush with the lateral shell body and the medial shell body, or both the upper surface and the lower surface of the midsole core are flush with the lateral shell body and the medial shell body.

Clause 14. The article of footwear of any of clauses 11-13, wherein: at least one of the medial shell body or the lateral shell body has an inner side and an outer side and defines at least one through hole extending from the inner side to the outer side; and the midsole core extends across the at least one through hole at the inner side.

Clause 15. The article of footwear of any of clauses 11-13, wherein: the lateral shell body and the medial shell body each have an inner rim extending inward into the central cavity; and the midsole core interfits with the lateral shell body and the medial shell body at the inner rim so that the inner rim rests on the midsole core.

Clause 16. The article of footwear of any of clauses 11-15, wherein: the lateral shell body has a bonding surface forward of the midsole core; and the medial shell body has a bonding surface forward of the midsole core contiguous with and coupled to the bonding surface of the lateral shell body.

Clause 17. The article of footwear of any of clauses 11-16, wherein: the lateral shell body has a bonding surface rearward of the midsole core; and the medial shell body has a bonding surface rearward of the midsole core contiguous with and coupled to the bonding surface of the lateral shell body.

Clause 18. The article of footwear of clause 17, wherein the bonding surface of the lateral shell body and the bonding surface of the medial shell body extend in a longitudinal direction of the article of footwear.

Clause 19. The article of footwear of any of clauses 11-18, further comprising: an outsole extending across and secured to the lower surface of the midsole core, a lower surface of the lateral shell body, and a lower surface of the medial shell body.

Clause 20. The article of footwear of any of clauses 11-19, further comprising: a heel counter secured to an upper surface of the lateral shell body and an upper surface of the medial shell body in a heel region of the article of footwear.

Clause 21. The article of footwear of any of clauses 10-20, wherein the midsole core is a first foam material and the outer shell is a second foam material different than the first foam material.

Clause 22. The article of footwear of any of clauses 9-21, the cushioning component further comprising a dye mixed in the resin binder.

Clause 23. The article of footwear of any of clauses 9-22, wherein the scrap foam pieces comprise Pebax® foam and the resin binder comprises polyurethane.

Clause 24. An article of footwear comprising: a midsole including: a first cushioning component configured as a midsole core; and a second cushioning component configured as an outer shell defining a central cavity; wherein the midsole core is disposed in the central cavity with the outer shell bordering a lateral side and a medial side of the midsole core and defining a plurality of through holes exposing the lateral side and the medial side of the midsole core.

Clause 25. The article of footwear of clause 24, wherein the central cavity is a through hole and an upper surface and a lower surface of the midsole core are exposed in the central cavity.

Clause 26. The article of footwear of any of clauses 24-25, wherein the outer shell comprises: a lateral shell body extending along the lateral side of the midsole core; a medial shell body extending along the medial side of the midsole core; and wherein the lateral shell body is coupled to the medial shell body forward of the midsole core and rearward of the midsole core.

Clause 27. The article of footwear of clause 26, wherein an upper surface of the midsole core is flush with the lateral shell body and the medial shell body, a lower surface of the midsole core is flush with the lateral shell body and the medial shell body, or both the upper surface and the lower surface of the midsole core are flush with the lateral shell body and the medial shell body.

Clause 28. The article of footwear of any of clauses 26-27, wherein at least one of the medial shell body or the lateral shell body has an inner side and an outer side and at least one of the plurality of through holes extends from the inner side to the outer side and the midsole core extends across the through hole at the inner side.

Clause 29. The article of footwear of any of clauses 26-28, wherein: the lateral shell body and the medial shell body each have an inner rim extending inward into the central cavity; and the midsole core interfits with the lateral shell body and the medial shell body at the inner rim so that the inner rim rests on the midsole core.

Clause 30. The article of footwear of any of clauses 26-29, wherein: the lateral shell body has a bonding surface forward of the midsole core; and the medial shell body has a bonding surface forward of the midsole core contiguous with and coupled to the bonding surface of the lateral shell body.

Clause 31. The article of footwear of any of clauses 26-30, wherein: the lateral shell body has a bonding surface rearward of the midsole core; and the medial shell body has a bonding surface rearward of the midsole core contiguous with and coupled to the bonding surface of the lateral shell body.

Clause 32. The article of footwear of any of clauses 26-31, wherein the bonding surface of the lateral shell body and the bonding surface of the medial shell body extend in a longitudinal direction of the article of footwear.

Clause 33. The article of footwear of any of clauses 26-32, further comprising: an outsole extending across and secured to the lower surface of the midsole core, a lower surface of the lateral shell body, and a lower surface of the medial shell body.

Clause 34. The article of footwear of any of clauses 26-33, further comprising: a heel counter secured to an upper surface of the lateral shell body and an upper surface of the medial shell body in a heel region of the article of footwear.

Clause 35. The article of footwear of any of clauses 26-34, wherein the midsole core includes recycled foam pieces and resin binder coating the recycled foam pieces.

Clause 36. The article of footwear of clause 35, wherein the midsole core further includes a dye mixed in the resin binder.

Clause 37. The article of footwear of any of clauses 35-36, wherein the recycled foam pieces comprise Pebax® foam and the resin binder comprises polyurethane.

To assist and clarify the description of various embodiments, various terms are defined herein. Unless otherwise indicated, the following definitions apply throughout this specification (including the claims). Additionally, all references referred to are incorporated herein in their entirety.

An “article of footwear”, a “footwear article of manufacture”, and “footwear” may be considered to be both a machine and a manufacture. Assembled, ready to wear footwear articles (e.g., shoes, sandals, boots, etc.), as well as discrete components of footwear articles (such as a midsole, an outsole, an upper component, etc.) prior to final assembly into ready to wear footwear articles, are considered and alternatively referred to herein in either the singular or plural as “article(s) of footwear”.

For consistency and convenience, directional adjectives may be employed throughout this detailed description corresponding to the illustrated embodiments. Those having ordinary skill in the art will recognize that terms such as “above”, “below”, “upward”, “downward”, “top”, “bottom”, etc., may be used descriptively relative to the figures, without representing limitations on the scope of the invention, as defined by the claims.

The term “longitudinal” refers to a direction extending a length of a component. For example, a longitudinal direction of a shoe extends between a forefoot region and a heel region of the shoe. The term “forward” or “anterior” is used to refer to the general direction from a heel region toward a forefoot region, and the term “rearward” or “posterior” is used to refer to the opposite direction, i.e., the direction from the forefoot region toward the heel region. In some cases, a component may be identified with a longitudinal axis as well as a forward and rearward longitudinal direction along that axis. The longitudinal direction or axis may also be referred to as an anterior-posterior direction or axis.

The term “transverse” refers to a direction extending along a width of a component. For example, a transverse direction of a shoe extends between a lateral side and a medial side of the shoe. The transverse direction or axis may also be referred to as a lateral direction or axis or a mediolateral direction or axis.

The term “vertical” refers to a direction generally perpendicular to both the lateral and longitudinal directions. For example, in cases where a sole is planted flat on a ground surface, the vertical direction may extend from the ground surface upward. It will be understood that each of these directional adjectives may be applied to individual components of a sole. The term “upward” or “upwards” refers to the vertical direction pointing towards a top of the component, which may include an instep, a fastening region and/or a throat of an upper. The term “downward” or “downwards” refers to the vertical direction pointing opposite the upwards direction, toward the bottom of a component and may generally point towards the bottom of a sole structure of an article of footwear.

The “interior” of an article of footwear, such as a shoe, refers to portions at the space that is occupied by a wearer's foot when the shoe is worn. The “inner side” of a component refers to the side or surface of the component that is (or will be) oriented toward the interior of the component or article of footwear in an assembled article of footwear. The “outer side” or “exterior” of a component refers to the side or surface of the component that is (or will be) oriented away from the interior of the shoe in an assembled shoe. In some cases, other components may be between the inner side of a component and the interior in the assembled article of footwear. Similarly, other components may be between an outer side of a component and the space external to the assembled article of footwear. Further, the terms “inward” and “inwardly” refer to the direction toward the interior of the component or article of footwear, such as a shoe, and the terms “outward” and “outwardly” refer to the direction toward the exterior of the component or article of footwear, such as the shoe. In addition, the term “proximal” refers to a direction that is nearer a center of a footwear component, or is closer toward a foot when the foot is inserted in the article of footwear as it is worn by a user. Likewise, the term “distal” refers to a relative position that is further away from a center of the footwear component or is further from a foot when the foot is inserted in the article of footwear as it is worn by a user. Thus, the terms proximal and distal may be understood to provide generally opposing terms to describe relative spatial positions.

While several modes for carrying out the many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative aspects for practicing the present teachings that are within the scope of the appended claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and exemplary of the entire range of alternative embodiments that an ordinarily skilled artisan would recognize as implied by, structurally and/or functionally equivalent to, or otherwise rendered obvious based upon the included content, and not as limited solely to those explicitly depicted and/or described embodiments.