Footwear with Jointed Sole Structure for Ease of Access

This application is a continuation of and claims the benefit of priority to U.S. Nonprovisional application Ser. No. 18/519,289, filed Nov. 27, 2023, which claims the benefit of priority to U.S. Provisional Application No. 63/428,370 filed Nov. 28, 2022, and each of which are hereby incorporated by reference in their entirety.

The present disclosure generally relates to an article of footwear, and more specifically to an article of footwear with a jointed sole structure for ease of access.

Traditionally, placing footwear on a foot often requires the use of one or both hands to stretch the ankle opening of a footwear upper and hold the rear portion during foot insertion. The fit of the upper is then adjusted following foot insertion, such as by tying laces.

An article of footwear disclosed herein may enable hands-free placement of the article of footwear on a foot by providing a sole structure with separate front and rear midsole components that define a groove at a lower side of the sole structure with a hinge disposed in the groove and connecting the midsole components. The hinge enables the sole structure to pivot (e.g., articulate) at the groove between a first orientation, referred to as a use position in which the groove is relatively open, and a second orientation, referred to as an access position in which the groove is relatively closed.

In some examples, separate front and rear upper portions may be secured to the front and rear midsole components. At least parts of the front and rear upper portions may be further apart from one another in the access position than in the use position, allowing easier foot entry into the front upper portion, and with the rear upper portion then automatically closing around the foot as the footwear returns to the use position under a load of the foot.

In some implementations, the article of footwear may be characterized by the absence of a biasing member extending between and connecting the front midsole component and the rear midsole component, or extending between and connecting the front upper portion and the rear upper portion, or extending between and connecting the front upper portion and the rear midsole component, or extending between and connecting the front midsole component and the rear upper portion, and configured to maintain the sole structure in the access position and/or in the use position. Instead, for example, the outsole may be characterized by at least a predetermined coefficient of friction (e.g., a static coefficient of friction and/or a sliding coefficient of friction of at least a predetermined magnitude) to maintain the sole structure in the access position until loaded by a foot to move to the use position. For example, the material and configuration of the outsole alone may provide at least the predetermined coefficient of friction to maintain the sole structure in the access position until loaded by a foot to move to the use position without any of an elastic band(s), biasing plate(s), or other component(s) included primarily to provide a biasing force that urges the sole structure toward the access position and/or the use position.

In addition, in some examples, the front midsole component may include a heel footbed that extends over the groove and overlays the rear midsole component in the use position. The article of footwear may include a divided footwear upper with a front upper portion secured to the front midsole component and a separate rear upper portion secured to the rear midsole component. The rear upper portion may include at least a portion of a heel collar, and the heel collar may be configured to support the heel footbed in the access position and resiliently deform to permit the heel footbed to move past the heel collar to the use position.

In an example, a resilient band may be suspended over and extend transversely across a portion of the inner surface of the rear midsole component (e.g., the top surface, also referred to as the foot support surface). For example, the resilient band may be secured to the inner surface at the medial and lateral side walls of the rear midsole component. In the access position, the resilient band may be spaced apart from portion of the inner surface of the rear midsole component and a heel footbed may rest on the resilient band. In the use position, the resilient band may resiliently stretch under load to allow the heel footbed to rest on the inner surface of the rear midsole component.

In an aspect, a side of the heel footbed and an inner surface of the rear midsole component may include complementary interlocking features that secure the heel footbed in the use position. In some examples, a tab may protrude at a side periphery of the heel footbed, and the rear midsole component may at least partially define a recess at an inner surface of the rear midsole component in which the tab is disposed to secure the heel footbed in the use position until a removal force is applied to the sole structure as discussed herein. The medial side of the heel footbed, the lateral side of the heel footbed, or both, may include such a tab. In other examples, the side periphery of the heel footbed may include a recess and the rear midsole component may include a tab protruding at the inner surface of the rear midsole component that is disposed in the recess of the heel footbed to secure the heel footbed in the use position until a removal force is applied to the sole structure as discussed herein.

In an example, the sole structure may comprise a stiffening layer secured to the side periphery of the heel footbed and the medial-side tab and the lateral-side tab may be integral with the stiffening layer.

In another example, a peripheral support may be secured to the rear midsole component, such as at the inner side walls at the inner surface of the rear midsole component and may have an edge disposed adjacent to the recess in the rear midsole component. The wall support may be stiffer than the rear midsole component and the tab may be disposed in the recess under the edge of the wall support when the sole structure is in the use position to secure the heel footbed in the use position. In this manner, the more rigid wall support helps to maintain the tab in the recess.

The hands-free operation of the article of footwear may be made possible by these and/or other aspects described herein.

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. It should be understood that even though embodiments may be separately described in the following Figures, single features thereof may be combined in additional embodiments.

Referring to the drawings, wherein like reference numbers refer to like components throughout the views,shows an example of an article of footwear(also referred to herein simply as footwear) that includes a sole structureand a footwear upper(also referred to herein as an upper). As discussed herein, these and other features of the article of footwearenable an access position of the article of footwear(such as shown in) that particularly affords easy, hands-free foot entry into the article of footwear. Additionally, the article of footwearadopts a use position (such as shown in) after foot entry, particularly also in a hands-free manner. The article of footwearherein is depicted as a leisure shoe or an athletic shoe, but the present teachings are not limited to such, and also encompass dress shoes, work shoes, sandals, slippers, boots, or any other category of footwear.

The article of footwearhas three general regions: a forefoot region, a midfoot region, and a heel region, which are also the forefoot region, the midfoot region, and the heel region, respectively, of the sole structureand the footwear upper. The footwearalso includes a medial sideand a lateral side(best shown in) opposite from the medial side.

The forefoot regiongenerally includes portions of the article of footwearcorresponding with the toes and the joints connecting the metatarsals with the phalanges of a wearer's foot. The midfoot regiongenerally includes portions of the article of footwearcorresponding with the arch area of the foot, and the heel regioncorresponds with rear portions of the foot, including the calcaneus bone. The medial sideand the lateral sideextend through each of forefoot region, the midfoot region, and the heel regionand correspond with opposite sides of the article of footwear. The forefoot region, the midfoot region, the heel region, the medial side, and the lateral sideare not intended to demarcate precise areas of footwearbut are instead intended to represent general areas of footwearto aid in the following discussion.

The sole structureincludes a midsolethat has a front midsole componentA and a separate rear midsole componentB. The rear midsole componentB is separate and divided from the front midsole componentA. Stated differently, the front midsole componentA particularly is not integrally formed with, is not unitary with, and/or is not directly attached to the rear midsole componentB. The front midsole componentA and the rear midsole componentB together define a grooveat a lower sideof the sole structurebetween the front midsole componentA and the rear midsole componentB.

The footwear uppermay be a divided footwear upper having a front upper portionA and a rear upper portionB. The divided footwear upperis secured to the sole structureto define a foot-receiving cavity. More particularly, the front upper portionA is secured to the front midsole componentA, and the separate rear upper portionB is secured to the rear midsole componentB. The footwear upperis referred to as divided because the front upper portionA and the rear upper portionB are separate, discrete upper components that are not physically directly connected to one another.

A hingeis disposed in the grooveand connects the front midsole componentA to the rear midsole componentB. The front midsole componentA and the rear midsole componentB are pivotable relative to one another at the groovebetween a use position (shown in) and an access position (shown in). The grooveis relatively open in the use position and relatively closed in the access position.

Referring to, the front midsole componentA includes a first walldefining a front of the groove. The rear midsole componentB includes a second walldefining a rear of the groove. The hingehas a first wallA that lines the first wall. The hingehas a second wallB integral with the first wallA. The first wallA and the second wallB define a peaktherebetween. The second wallB of the hingelines the second wallof the rear midsole componentB. The hingeflexes at the peakwhen the sole structuremoves between the use position and the access position.

Confronting surfaces of the hingeat the groove(e.g., exposed surfaces or outer surfaces of the first wallA and the second wallB of the hinge) are closer to one another in the access position (see) than in the use position (see) so that the grooveis relatively open in the use position in comparison to the access position, and the grooveis relatively closed in the access position in comparison to the use position. Specifically, as shown in, the grooveis relatively open and/or the front upper portionA and the rear upper portionB are adjacent to one another in the use position. As shown in, the grooveis relatively closed and at least parts of the front upper portionA and the rear upper portionB are spaced further apart from one another in the access position than in the use position, widening the ankle openingin comparison to the use position to ease foot entry.

The sole structurefurther includes an outsole. In the example shown, the outsoleincludes three discrete components: a front outsole componentA, a rear outsole componentB, and a toe region outsole componentC, as best shown in. The front outsole componentA and the toe region outsole componentC are secured to the bottom surfaceof the front midsole componentA (see). The toe region outsole componentC is discrete and separate from the front outsole componentA. The front midsole componentA spans a gap(see) between the toe region outsole componentC and the front outsole componentA and may extend at least partially downward into the gapbetween the toe region outsole componentC and the front outsole componentA. The rear outsole componentB is secured to a bottom surfaceof the rear midsole componentB and is discrete and separate from the front midsole componentA. The front outsole componentA is entirely forward of the grooveand the rear outsole componentB is entirely rearward of the groove.

The hingeincludes a forward legC integral with the first wallA and extending forward from the first wallA under the front midsole componentA. The hingefurther includes a rear legD integral with the second wallB and extending rearward from the second wallB under the rear midsole componentB. The front outsole componentA is secured to the bottom surface of the forward legC of the hinge, and the rear outsole componentB is secured to the bottom surface of the rear legD of the hinge. For example, the outsole componentsA,B, andC may be secured to the respective front and rear midsole componentsA,B and the outsole componentsA,B to the respective forward and rear legsC,D with adhesive, by heat bonding, or otherwise.

In, the grooveparticularly is configured as substantially having a triangular shape in a cross-section taken along a longitudinal length of the article of footwear. In other examples, the groovemay be more semi-circular, square, or rectangular in cross-section. The groovemay have any cross-sectional shape that allows the two midsole componentsA,B to pivot relative to one another at the groove. The peakof the hingeor the top of the grooveat a cross-section through the grooveparticularly is configured to permit flexing of the material for opening and closing of the groovewhile minimizing or reducing stress concentrations or fatigue. For example, if a top of the grooveand a peakof the hingeparticularly extends from the lateral sideto the medial sideof the sole structure, then internal forces resulting from the flexing (such as forces on the hinge) are spread across the width of the sole structure, reducing stress concentrations. Additionally, if the top of the grooveand the peakof the hingeparticularly have a relatively rounded rather than a relatively pointed shape (e.g., do not have a pointed apex), internal forces are spread over a greater area of the material, reducing stress concentrations in comparison to a pointed groove.

The front midsole componentA and the rear midsole componentB may comprise, for example, an elastomeric foam such as a polyurethane or ethylvinylacetate foam to attenuate ground reaction forces (i.e., provide cushioning) when compressed between the foot and the ground during walking, running, or other ambulatory activities. Either or both of the front midsole componentA and the rear midsole componentB may incorporate fluid-filled chambers, plates, moderators, or other elements that further attenuate forces, enhance stability, or influence the motions of the foot. For example, the heel footbedof the front midsole componentA discussed herein may include a first plateand a second plateas discussed with respect to the article of footwear.

In the example shown, the foam of the midsole componentsA,B may include a foamed polymeric material and may be at least partially a polyurethane (PU) foam, a polyurethane ethylene-vinyl acetate (EVA) foam, and may include heat-expanded and molded EVA foam pellets.

The foamed polymeric material includes one or more polymers. The one or more polymers may include an elastomer, including a thermoplastic elastomer (TPE). The one or more polymers may include aliphatic polymers, aromatic polymers, or mixture of both. In one example, the one or more polymers may include homopolymers, copolymers (including terpolymers), or mixtures of both. The copolymers may be random copolymers, block copolymers, alternating copolymers, periodic copolymers, or graft copolymers, for instance. The one or more polymers may include olefinic homopolymers or copolymers or a mixture of olefinic homopolymers and copolymers. Examples of olefinic polymers include polyethylene (PE) and polypropylene (PP). For example, the PE may be a PE homopolymer such as a low density PE or a high density PE, a low molecular weight PE or an ultra-high molecular weight PE, a linear PE or a branched chain PE, etc. The PE may be an ethylene copolymer such as, for example, an ethylene-vinyl acetate (EVA) copolymer, an ethylene-vinyl alcohol (EVOH) copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-unsaturated mono-fatty acid copolymer, etc. The one or more polymers may include a polyacrylate such as a polyacrylic acid, an ester of a polyacrylic acid, a polyacrylonitrile, a polyacrylic acetate, a polymethyl acrylate, a polyethyl acrylate, a polybutyl acrylate, a polymethyl methacrylate, a polyvinyl acetate, etc., including derivatives thereof, copolymers thereof, and any mixture thereof, in one example. The one or more polymers may include an ionomeric polymer. The ionomeric polymer may be a polycarboxylic acid or a derivative of a polycarboxylic acid, for instance. The ionomeric polymer may be a sodium salt, a magnesium salt, a potassium salt, or a salt of another metallic ion. The ionomeric polymer may be a fatty acid modified ionomeric polymer. Examples of ionomeric polymers include polystyrene sulfonate, and ethylene-methacrylic acid copolymers. The one or more polymers may include a polycarbonate. The one or more polymers may include a fluoropolymer. The one or more polymers may include a polysiloxane. The one or more polymers may include a vinyl polymer such as polyvinyl chloride (PVC), polyvinyl acetate, polyvinyl alcohol, etc. The one or more polymers may include a polystyrene. The polystyrene may be a styrene copolymer such as, for example, an acrylonitrile butadiene styrene (ABS), a styrene acrylonitrile (SAN), a styrene ethylene butylene styrene (SEBS), a styrene ethylene propylene styrene (SEPS), a styrene butadiene styrene (SBS), etc. The one or more polymers may include a polyamide (PA). The PA may be a PA 6, PA 66, PA 11, or a copolymer thereof. The polyester may be an aliphatic polyester homopolymer or copolymer such as polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyrate, and the like. The polyester may be a semi-aromatic copolymer such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT). The one or more polymers may include a polyether such as a polyethylene glycol or polypropylene glycol, including copolymers thereof. The one or more polymers may include a polyurethane, including an aromatic polyurethane derived from an aromatic isocyanate such as diphenylmethane diisocyanate (MDI) or toluene diisocyanate (TDI), or an aliphatic polyurethane derived from an aliphatic isocyanate such as hexamethylene diisocyanate (HDI) or isophone diisocyanate (IPDI), or a mixture of both an aromatic polyurethane and an aliphatic polyurethane.

The foamed polymeric material may be a chemically foamed polymeric material, which is foamed using a chemical blowing agent that forms a gas when heated. For example, the chemical blowing agent can be an azo compound such as azodicarbonamide, sodium bicarbonate, or an isocyanate. Alternatively, or additionally, the foamed polymeric material may be a physically foamed polymeric material, which is foamed using a physical blowing agent which changes phase from a liquid or a supercritical fluid to a gas due to changes in temperature and/or pressure.

Optionally, in addition to the one or more polymers, the polymeric material may further include one or more fillers such as glass fiber, powdered glass, modified or natural silica, calcium carbonate, mica, paper, wood chips, modified or natural clays, modified or unmodified synthetic clays, talc, etc. Similarly, the polymeric material optionally may further include one or more colorants, such as pigments or dyes. Other optional components of the polymeric material include processing aids, ultra-violet light absorbers, and the like.

The foamed polymeric material may be a crosslinked foamed polymeric material, i.e., a foamed material in which covalent crosslinking bonds exist between at least a portion of the one or more polymers. A crosslinked foamed polymeric material can be formed by including a crosslinking agent in the polymeric material used to form the foam. The crosslinking agent can be a peroxide-based crosslinking agent such as dicumyl peroxide. Alternatively, the foamed polymeric material can be an uncrosslinked foamed polymeric material which has thermoplastic properties. The foamed polymeric material may be an elastomeric foamed material.

The front midsole componentA extends in the forefoot regionand the midfoot region, and/or particularly includes a heel footbed(see, e.g.,) that extends in the heel region. Accordingly, the front midsole componentA particularly is a full-length midsole component. In other examples, there may be no heel footbed, or there may be a footbed portion extending rearward over the groovethat does not extend fully to the heel region. The heel footbedextends over the grooveand overlays the rear midsole componentB in the use position and is spaced apart from the rear midsole componentB in the access position. The heel footbedoverlays and contacts a portionof the inner surfaceof the rear midsole componentB in the use position, inward of the rear upper portionB, as shown in phantom inand discussed herein with respect to corresponding components of the article of footwear. The portionis also referred to as the top surface and/or the foot-facing surface and/or foot support surface and/or top-facing surface of the rear midsole componentB.

As shown in, the heel footbedextends the full width of the foot-receiving cavitybetween the medial and lateral sides of the rear upper portionB discussed herein. In other examples, the heel footbedneed not extend the full width.

The heel footbedparticularly is an integral portion of the front midsole componentA. Stated differently, the front midsole componentA, including the heel footbed, may be a one-piece component, e.g., formed by injection molding or otherwise. In contrast, the rear midsole componentB particularly is not a full-length midsole component, as it extends in the heel region, but does not extend in the forefoot region, and/or extends only slightly, if at all, in the midfoot region. The rear midsole componentB particularly extends mainly rearward of the grooveand mainly in the heel region.

The article of footwearis characterized by an absence of a biasing member configured to maintain the sole structurein one of the use position or the access position (e.g., in a bi-stable arrangement). For example, the footwear upperand the sole structureare characterized by an absence of (e.g., do not include) a biasing member extending between the front upper portionA and the rear upper portionB, or between the front midsole componentA and the rear midsole componentB, or between the front upper portionA and the rear midsole componentB, or between the rear upper portionB and the front midsole componentA, etc. Accordingly, no bands, straps, biasing plates, etc. are added to the article of footwearto bias the article of footwearto the use position and/or the access position. Instead, the outsoleis characterized by at least a predetermined coefficient of friction (e.g., a predetermined coefficient of static friction and/or a predetermined coefficient of sliding friction) to maintain the sole structurein the access position. Stated differently, the outsoleis of a material and a configuration such that contact of the outsolewith the ground surface GS when in the access position ofprovides sufficient forces resisting relative movement of the outsole componentsA,B, and/orC, such as sliding of the sole structureon the ground surface GS and preventing the article of footwearfrom moving to the use position without the loading of an entering foot. Alternatively or in addition, a resilient band such as the resilient banddescribed with respect tomay be used to help maintain the article of footwearin the access position.

As shown in, a portion of the rear outsole componentB and a portion of the front outsole componentA and/or the toe region outsole componentC rest on the ground surface GS in the access position. By selecting the materials of the outsoleto provide at least the predetermined coefficient of friction (e.g., a predetermined coefficient of static friction and/or a predetermined coefficient of sliding friction) on various selected materials of the ground surface GS, such as typical flooring surfaces, concrete, etc., according to ASTM standardized test(s), no biasing member is needed to maintain the article of footwear in the access position.

In an example, the outsolemay be formed from materials that may generally include natural or synthetic rubber or other suitably durable materials. The material or materials for the outsolemay be selected to provide a desirable combination of durability, flexibility, and at least the predetermined coefficient of friction discussed herein. Synthetic rubbers that may be used include polybutadiene rubber, ethylene propylene rubber (EPR), styrene isoprene styrene (SIS) copolymer rubber, and styrene butadiene rubber.

Referring to, the outsole componentsA,B, andC each include a plurality of spaced tread elementsonly some of which are indicated reference numbers in. Alternatively, none of or only one or two of the outsole componentsA,B, andC may include such tread elements. The tread elementsextend from a medial side edgeA to a lateral side edgeB of the sole structurein each of the forefoot region, the midfoot region, and the heel region. The tread elementsextend downward and define a portion of the ground engaging surfaceof the sole structure. The tread elementsensure sufficient contact with the ground surface GS even in the case of an uneven ground surface. Additionally, the tread elementshave sufficient compliance to increase friction relative to the ground surface GS in comparison to a ground engaging surface without the tread elements.

Optionally, interference between the rear upper portionB and the heel footbedfurther enhances the ability to maintain the article of footwearin the access position in the absence of loading of an entering foot. For example, in the access position of, the rear upper portionB is shown including a heel collar. The heel collarof the rear upper portionB along with a medial-side front collar portionA and a lateral-side front collar portionB of the front upper portionA define an ankle openingthat is wider in the access position (see) than in the use position (see). A medial side portionA of the heel collarand a lateral side portionB of the heel collarare spaced sufficiently close to one another and include sufficient compliant cushioning that the medial and lateral side portionsA,B of the heel collarsupport the heel footbedin the access position (in the absence of loading by an entering foot) and resiliently deform to permit the heel footbedto move past the heel collarto the use position under loading of an entering foot.

The rear upper portionB and the front upper portionA may include any one or more of several different materials. For example, the rear upper portionB and the front upper portionA may include leather, textiles, polymers, cotton, foam, composites, etc., or combinations of these. The rear upper portionB and the front upper portionA may be a polymeric material capable of providing elasticity, and may be of a braided construction, a knitted (e.g., warp-knitted) construction, or a woven construction.

shows the article of footwear with the sole structurearticulated even further than the access position of(e.g., the grooveis further closed than in) exposing more of the heel footbedthan in the access position of. For example, the wallsA,B of the hingewill eventually touch to provide a stop (e.g., the groovecompletely closes to prevent further rotation or pivotal movement toward one another), but the exterior surfaces of the first and second wallsA,B in the grooveneed not necessarily touch in the access position of.

To help maintain the article of footwearin the use position,shows that the sole structureincludes a lateral-side tabprotruding at a lateral-side peripheryof the heel footbed. In the example shown, the sole structureincludes a lateral-side stiffening layersecured at the lateral-side peripheryof the heel footbed, and the lateral-side tabis an integral portion of the lateral-side stiffening layer. The lateral-side stiffening layerand the integral lateral-side tabare stiffer than the heel footbed. Although not shown, the heel footbedmay include a like medial-side stiffening layer secured at the medial side periphery(see) of the heel footbedand a medial-side tab as an integral portion of the medial-side stiffening layer, as shown with respect to the article of footwearin. In, the lateral-side stiffening layerand the integral lateral-side tabare covered by the rear upper portionB in the access position.

The lateral-side stiffening layermay be secured to the bodyof the heel footbedsuch as with adhesive, or may be coated on the body, or otherwise applied to define a portion of the lateral-side peripheryof the heel footbed. In one example, the lateral-side stiffening layeris molded separately from the bodyand is then adhered to the body. In another example, foam used to form the bodymay be processed such as by temperature-controlled curing so that the lateral-side stiffening layeris an integral external skin of the bodythat is more dense than a remaining internal portion of the bodythat it covers.

The bodymay be relatively less hard than the lateral-side stiffening layerand the integral lateral-side tab. For example, the bodymay have a first hardness and the lateral-side stiffening layerand the integral lateral-side tabmay have a second hardness greater than the first hardness. For example, the bodymay be elastomeric foam, as discussed, and the lateral-side stiffening layerand the integral lateral-side tabmay be a semi-rigid or rigid plastic (such as a thermoplastic), a composite, nylon, a polyether block amide such as PEBAX® available from Arkema, Inc. in King of Prussia, Pennsylvania USA, a fiberglass reinforced polyamide, a rigid thermoplastic polyurethane (with or without glass fiber).

Because the protruding lateral-side tabis of the harder material of the lateral-side stiffening layer, the lateral-side tabmoves past softer, compressible portions of the rear upper portionB and the rear midsole componentB by compressing such portions when under loading of an entering foot and then interlocks with the rear midsole componentB in the use position. Specifically, the rear midsole componentB includes an inner surface(indicated in phantom in) with a lateral-side recess in a lateral side of the inner surface, as shown in greater detail with respect to the like inner surfaceof the rear midsole componentB of the article of footwearin. The lateral-side tabis disposed in the lateral-side recess when the sole structuremoves to the use position to secure the heel footbedin the use position. More specifically, the lateral-side tabin the lateral-side recess and/or a similar medial side tab in a medial side recess interlocks the heel footbedto the rear midsole componentB to help maintain the article of footwearin the use position.

To remove the article of footwearin a hands-free manner, the wearer's opposite foot may be placed on an external ledgeof the rear midsole componentB. The external ledgemay have a reinforcing coverthat is a relatively hard plastic, similar to the material of the lateral-side tab. By depressing the external ledgewith the wearer's opposite foot pushing down on the cover, the rear midsole componentB is urged to pivot downward and rearward with respect to the use position of, urging the sole structureto articulate to the access position, moving the grooveto the relatively closed position, and providing enough force to move the lateral-side taband any corresponding medial side tab out of the lateral-side recess and any corresponding medial side recess, to release the heel footbed, which moves to the access position ofas the front midsole componentA pivots about the grooverelative to the rear midsole componentB. The frictional forces of the outsoleon the ground surface GS are overcome to allow such articulation.

The rear midsole componentB may also include a forward-projecting clip (like clipdiscussed with respect to the article of footwear) that overlays the rear extent of the heel footbedin the use position to further help maintain the heel footbedin the use position. The forward-projecting clip flexibly interfaces with the rear extent of the heel footbedwhen the sole structuremoves from the use position to the access position. The clip may also be referred to as a lip.

show an article of footwearalike in all aspects to the article of footwearexcept that the shape of a rear midsole componentB of the article of footwearis more tapered at the rear than rear midsole componentB and includes a bottom recess(see), a reinforcing coverextends further around the medial and lateral sides,in the heel regionon the external ledgethan does the reinforcing coverof the article of footwear(as best shown in), and the outsole componentsA,B,C corresponding with outsole componentsA,B, andC, respectively, have a slightly differently layout of tread elements, as shown in. The rear outsole componentB includes an apertureat the bottom recess. The front outsole componentA underlies the forward legC of the hingeand the rear outsole componentB underlies the rear legD.

In the cross-sectional view of the hingeshown in, it is apparent that the hingeincludes a forward ridgeA at the intersection of the first wallA and the forward legC, and a rear ridgeB at the intersection of the second wallB and the rear legD. The ridgesA,B extend downward and serve as alignment features for securing the front and rear outsole componentsA,B to the front and rear legsC,D. The front outsole componentA is abutted against the front ridgeA and the rear outsole componentB is abutted against the rear ridgeB to properly align the outsole componentsA,B with the hinge.

Like the article of footwear, the article of footwearis also characterized by an absence of a biasing member configured to maintain the sole structurein one of the use position or the access position (e.g., in a bi-stable arrangement). For example, the footwear upperand the sole structureare characterized by an absence of a biasing member extending between the front upper portionA and the rear upper portionB, or between the front midsole componentA and the rear midsole componentB, or between the front upper portionA and the rear midsole componentB, or between the rear upper portionB and the front midsole componentA. Accordingly, no bands, straps, biasing plates, etc. are included to bias the article of footwearto the use position and/or the access position. Instead, the outsoleis characterized by at least a predetermined coefficient of friction (e.g., of static friction or of sliding friction) to maintain the sole structurein the access position. Stated differently, the outsoleis of a material and a configuration such that contact of the outsolewith the ground surface GS when in the access position like that of the article of footwearinprovides sufficient forces to resist relative movement of the outsole componentsA,B, and/orC such as sliding of the sole structureon the ground surface GS and preventing the article of footwearfrom moving to the use position without the loading of an entering foot.

In the access position, the outsolerests on a portion of the rear outsole componentB and on a portion of the front outsole componentA and/or the toe region outsole componentC. By selecting the materials of the outsoleto provide at least a predetermined coefficient of friction (e.g., of static friction or of sliding friction) on various selected materials of the ground surface GS, such as typical flooring surfaces, concrete, etc., according to ASTM standardized test(s), no biasing member is needed to maintain the article of footwearin the access position.