Vacuum Locking for Article of Footwear or Apparel

This application is a continuation of U.S. Non-Provisional application Ser. No. 18/068,035, filed Dec. 19, 2022, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 63/292,295, filed Dec. 21, 2021. The disclosures of these prior applications are considered part of the disclosure of this application and are hereby incorporated by reference in their entirety.

The present disclosure relates generally to a locking device for an article of apparel or footwear.

This section provides background information related to the present disclosure and is not necessarily prior art.

Articles of apparel, such as garments and headwear, and articles of footwear, such as shoes and boots, typically include a receptacle for receiving a body part of a wearer. For example, an article of footwear may include an upper and a sole structure that operate to form a receptacle for receiving a foot of a wearer. Likewise, garments and headwear may include one or more pieces of material formed into a receptacle for receiving a torso or head of a wearer.

Articles of apparel or footwear are typically adjustable and/or include a relatively flexible material to allow the article of apparel or footwear to accommodate various sizes of wearers, or to provide different fits on a single wearer. While conventional articles of apparel and articles of footwear are adjustable, such articles do not typically allow a wearer to lock the size or shape of the article to a body part of the wearer. For example, while laces adequately secure an article of footwear to a wearer by contracting or constricting a portion of an upper around the wearer's foot, the laces do not cause the upper to lock in a size or shape conforming to the user's foot. Accordingly, an optimum fit of the upper around the foot is difficult to achieve.

Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure.

The terminology used herein is for the purpose of describing particular exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, attached, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections. These elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example configurations.

In one configuration, a locking structure for an article includes a bladder having a first barrier element attached to a second barrier element to define a chamber including an interior void and a plurality of locking elements disposed within the interior void and each attached to at least one of the first barrier element and the second barrier element, each of the locking elements including an interface surface operable to selectively engage an interface surface of another one of the locking elements.

The locking structure may include one or more of the following optional features. For example, each of the locking elements may include an anchor attached to an inner surface of one of the first barrier element and the second barrier element. Additionally or alternatively, each of the locking elements may include a locking body having the interface surface. In this configuration, each of the locking elements may include a pair of interface surfaces disposed on opposite sides of the locking body and/or the locking body may be contoured.

In another configuration, a port may be in fluid communication with the interior void and/or a compressible component may be disposed within the interior void. The bladder may include a third barrier element attached to the first barrier element and the second barrier element, the third barrier element formed within the chamber to define a first subchamber having a first interior void and a second subchamber having a second interior void. In this configuration, the plurality of locking elements may be disposed within the first interior void and the compressible component may be disposed within the second interior void. Finally, the first subchamber having the first interior void may include a first port in communication with the first interior void and the second subchamber having the second interior void may include a second port in communication with the second interior void.

In another configuration, a locking structure for an article includes a bladder having a first barrier element attached to a second barrier element to define a chamber including an interior void and a locking system including locking elements each attached to one of the first barrier element or the second barrier element and including at least one interface surface, the interior void of the bladder operable between a first pressure to move the locking system to a locked state and a second pressure to move the locking system to an unlocked state.

The locking structure may include one or more of the following optional features. For example, each of the locking elements may include an anchor attached to an inner surface of one of the first barrier element and the second barrier element. Additionally or alternatively, each of the locking elements may include a locking body having the interface surface. In this configuration, each of the locking elements may include a pair of interface surfaces disposed on opposite sides of the locking body and/or the locking body may be contoured.

In one configuration, a port may be in fluid communication with the interior void. Further, a compressible component may be disposed within the interior void. In this configuration, the bladder may include a third barrier element attached to the first barrier element and the second barrier element, the third barrier element formed within the chamber to define a first subchamber having a first interior void and a second subchamber having a second interior void. The locking system may be disposed within the first interior void and the compressible component may be disposed within the second interior void. The first subchamber having the first interior void may include a first port in communication with the first interior void, and the second subchamber having the second interior void may include a second port in communication with the second interior void.

An upper for an article of footwear may include the foregoing locking structures. Additionally or alternatively, an article of apparel may include the foregoing locking structures.

The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description, the drawings, and the claims.

Referring to, examples of a locking structureinclude a bladderand a locking systemattached to the bladder. The bladderincludes a first barrier layer(e.g., a first barrier element) attached to a second barrier layer(e.g., a second barrier element) formed on an opposite side of the bladderfrom the first barrier layer. A distance from the first barrier layerand the second barrier layerdefines a thickness of the bladder. The first barrier layerand the second barrier layercooperate to define a chamberhaving an interior void.

The locking systemincludes a plurality of locking elementsattached to at least one of the first barrier layerand the second barrier layerto form the locking system. As discussed in greater detail below, the plurality of locking elementsare operable to transition the locking systemof the locking structure-between an unlocked state (), where the bladderis free to stretch and conform around the wearer, and a locked state (B), where the bladderis restricted or locked from stretching or conforming. Each locking elementincludes a locking bodyhaving a first side and a second side. The first side of the locking bodydefines an interface surface, discussed in greater detail below, and the second side of the locking bodyincludes an anchorfor attaching the locking elementto one of the barrier layers,

In the illustrated examples, the first barrier layerincludes a first inner surfaceand a first outer surface, and the second barrier layerincludes a second inner surfaceand a second outer surface. The first inner surfaceand the second inner surfaceface each other and are joined to each other at discrete locations to form a peripheral seam.

As used herein, the term “barrier layer” (e.g., barrier layers,) encompasses both monolayer and multilayer films. In some embodiments, one or both of the barrier layers,are each produced (e.g., thermoformed or blow molded) from a monolayer film (a single layer). In other embodiments, one or both of the barrier layers,are each produced (e.g., thermoformed or blow molded) from a multilayer film (multiple sublayers). In either aspect, each layer or sublayer can have a film thickness ranging from about 0.2 micrometers to about 1 millimeter. In further embodiments, the film thickness for each layer or sublayer can range from about 0.5 micrometers to about 500 micrometers. In yet further embodiments, the film thickness for each layer or sublayer can range from about 1 micrometer to about 100 micrometers.

One or both of the barrier layers,can independently be transparent, translucent, and/or opaque. As used herein, the term “transparent” for a barrier layer and/or a chamber means that light passes through the barrier layer in substantially straight lines and a viewer can see through the barrier layer. In comparison, for an opaque barrier layer, light does not pass through the barrier layer and one cannot see clearly through the barrier layer at all. A translucent barrier layer falls between a transparent barrier layer and an opaque barrier layer, in that light passes through a translucent layer but some of the light is scattered so that a viewer cannot see clearly through the layer.

The barrier layers,can each be produced from an elastomeric material that includes one or more thermoplastic polymers and/or one or more cross-linkable polymers. In an aspect, the elastomeric material can include one or more thermoplastic elastomeric materials, such as one or more thermoplastic polyurethane (TPU) copolymers, one or more ethylene-vinyl alcohol (EVOH) copolymers, and the like.

As used herein, “polyurethane” refers to a copolymer (including oligomers) that contains a urethane group (—N(C═O)O—). These polyurethanes can contain additional groups such as ester, ether, urea, allophanate, biuret, carbodiimide, oxazolidinyl, isocynaurate, uretdione, carbonate, and the like, in addition to urethane groups. In an aspect, one or more of the polyurethanes can be produced by polymerizing one or more isocyanates with one or more polyols to produce copolymer chains having (—N(C═O)O—) linkages.

Examples of suitable isocyanates for producing the polyurethane copolymer chains include diisocyanates, such as aromatic diisocyanates, aliphatic diisocyanates, and combinations thereof. Examples of suitable aromatic diisocyanates include toluene diisocyanate (TDI), TDI adducts with trimethyloylpropane (TMP), methylene diphenyl diisocyanate (MDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), hydrogenated xylene diisocyanate (HXDI), naphthalene 1,5-diisocyanate (NDI), 1,5-tetrahydronaphthalene diisocyanate, para-phenylene diisocyanate (PPDI), 3,3′-dimethyldiphenyl-4,4′-diisocyanate (DDDI), 4,4′-dibenzyl diisocyanate (DBDI), 4-chloro-1,3-phenylene diisocyanate, and combinations thereof. In some embodiments, the copolymer chains are substantially free of aromatic groups.

In particular aspects, the polyurethane polymer chains are produced from diisocynates including HMDI, TDI, MDI, H12 aliphatics, and combinations thereof. In an aspect, the thermoplastic TPU can include polyester-based TPU, polyether-based TPU, polycaprolactone-based TPU, polycarbonate-based TPU, polysiloxane-based TPU, or combinations thereof.

In another aspect, the polymeric layer can be formed of one or more of the following: EVOH copolymers, poly(vinyl chloride), polyvinylidene polymers and copolymers (e.g., polyvinylidene chloride), polyamides (e.g., amorphous polyamides), amide-based copolymers, acrylonitrile polymers (e.g., acrylonitrile-methyl acrylate copolymers), polyethylene terephthalate, polyether imides, polyacrylic imides, and other polymeric materials known to have relatively low gas transmission rates. Blends of these materials as well as with the TPU copolymers described herein and optionally including combinations of polyimides and crystalline polymers, are also suitable.

The barrier layers,may include two or more sublayers (multilayer film) such as shown in Mitchell et al., U.S. Pat. No. 5,713,141 and Mitchell et al., U.S. Pat. No. 5,952,065, the disclosures of which are incorporated by reference in their entirety. In embodiments where the barrier layers,include two or more sublayers, examples of suitable multilayer films include microlayer films, such as those disclosed in Bonk et al., U.S. Pat. No. 6,582,786, which is incorporated by reference in its entirety. In further embodiments, the barrier layers,may each independently include alternating sublayers of one or more TPU copolymer materials and one or more EVOH copolymer materials, where the total number of sublayers in each of the barrier layers,includes at least four (4) sublayers, at least ten (10) sublayers, at least twenty (20) sublayers, at least forty (40) sublayers, and/or at least sixty (60) sublayers.

The chambercan be produced from the barrier layers,using any suitable technique, such as thermoforming (e.g. vacuum thermoforming), blow molding, extrusion, injection molding, vacuum molding, rotary molding, transfer molding, pressure forming, heat sealing, casting, low-pressure casting, spin casting, reaction injection molding, radio frequency (RF) welding, and the like. In an aspect, the barrier layers,can be produced by co-extrusion followed by vacuum thermoforming to produce an inflatable chamber, which can optionally include one or more valves (e.g., one way valves) that allows the chamberto be filled with a fluid (e.g., gas).

The chambercan be provided in a fluid-filled (e.g., as provided in footwear) or in an unfilled state. The chambercan be filled to include any suitable fluid, such as a gas or liquid. In an aspect, the gas can include air, nitrogen (N2), or any other suitable gas. The fluid provided to the chambercan result in the chamberbeing pressurized. Alternatively, the fluid provided to the chambercan be at atmospheric pressure such that the chamberis not pressurized but, rather, simply contains a volume of fluid at atmospheric pressure.

The chamberdesirably has a low gas transmission rate to preserve its retained gas pressure. In some embodiments, the chamberhas a gas transmission rate for nitrogen gas that is at least about ten (10) times lower than a nitrogen gas transmission rate for a butyl rubber layer of substantially the same dimensions. In an aspect, chamberhas a nitrogen gas transmission rate of 15 cubic-centimeter/square-meter⋅atmosphere⋅day (cm3/m2⋅atm⋅day) or less for an average film thickness of 500 micrometers (based on thicknesses of the barrier layers,). In further aspects, the transmission rate is 10 cm3/m2⋅atm⋅day or less, 5 cm3/m2⋅atm⋅day or less, or 1 cm3/m2⋅atm⋅day or less.

In some implementations, the first barrier layerand the second barrier layercooperate to define a geometry (e.g., thicknesses, width, and lengths) of the chamber. The peripheral seammay extend around the chamberto seal the fluid (e.g., air) within the chamber. Thus, the chamberis associated with an area of the bladderwhere inner surfaces,of the first and second barrier layers,are not joined together and, thus, are separated from one another.

In some examples, the barrier layers,may include the same materials to provide the chamberwith a homogenous barrier construction, such that both sides of the locking structurewill contract and relax at the same rate when pressure within the chamberis adjusted. Alternatively, a first one of the barrier layers,may be at least partially constructed of a different barrier material and/or configuration than the other one of the barrier layers,to selectively impart a contour as the locking structuretransitions between the relaxed state and the locked state. For example, one of the barrier layers,may be at least partially formed with a different modulus of elasticity and/or stiffness than the other barrier layer,, such that when the locking structuretransitions from the relaxed state to the locked state, the first one of the barrier layers,contracts at a different rate than the other barrier layer,to cause the locking structureto curl.

Each locking elementin the plurality of locking elementsincludes an interface surfaceconfigured to cooperate with the interface surfaceof an opposing one of the locking elementsto maintain the locking systemin the locked state. As discussed in greater detail below, the interface surfacesof the locking elementsmay include textured and/or high friction materials configured to restrict or prevent relative movement between opposing interface surfaces. Accordingly, when the interface surfaceof one locking elementin the plurality of locking elementsis in contact with an interface surfaceof a second locking elementin the plurality of locking elements, the locking elementscooperate to create a rigid locking layer. Examples of different geometries and surface configurations of locking elementsare discussed below with respect to.

In use, the locking structureis moved between the unlocked state and the locked state by adjusting the fluid pressure within the interior voidof the chamber. In some examples, the pressure within the interior voidcan be selectively adjusted from a first pressure (e.g., at or above ambient) to a second pressure (e.g., a pressure below ambient). For example, the pressure within the interior voidmay be reduced by drawing a vacuum within the interior void through a port(e.g.,) attached to the bladder. The vacuum may be drawn using a pressure source, such as a pumpintegrated within the footwearor provided as a peripheral (i.e., independent) accessory to the footwear. For illustrative purposes, the pumpis shown disposed in the heel regionof the sole structure(e.g.,). However, the pumpmay be attached or disposed in any portion of the article of footwear, such as on the upperor in other regions of the sole structure. Further, the pumpmay be a peripheral accessory not attached to the shoe, such as a hand pump. As the pressure is reduced (e.g., below ambient) within the interior void, the plurality of locking elementsare drawn toward one another and lock the locking structureinto place (e.g., the locked state). Conversely, to move the locking structureto the relaxed state, the pressure within the interior voidis increased and the plurality of locking elementsrelease from one another to allow movement of the locking structure.

With continued reference to, locking structureincludes a plurality of locking elementsdisposed within the interior voidof the chamber. As shown, a first plurality of locking elementsare disposed on the inner surfaceof the first barrier layerand a second plurality of locking elementsare disposed on the second inner surfaceof the second barrier layer. In some implementations, the plurality of locking elementsare integrally formed with the inner surfaces,of the barrier layers,. In other implementations, the plurality of locking elementsare mechanically attached to the inner surfaces,of the barrier layers,(e.g., individually welded).

In, the first plurality of locking elementsdisposed on the first inner surfaceof the first barrier layeroppose the second plurality of locking elementsdisposed on the second inner surfaceof the second barrier layer. While in the relaxed state (), the interface surfacesof the first plurality of locking elementsdisposed on the first inner surfaceof the first barrier layerare spaced apart and separated from the interface surfacesof the second plurality of locking elementsdisposed on the second inner surfaceof the second barrier layer. When the pressure in the interior voidof the chamberis reduced from a first pressure (e.g., at or above ambient) to a second pressure (e.g., below ambient), the inner surfaces,of the barrier layers,move toward one another to bring the interface surfacesof the first plurality of locking elementsinto direct contact with the opposing interface surfacesof the second plurality of locking elements. Once the first plurality of locking elementsare in direct contact with the opposing second plurality of locking elementsat the respective interface surfaces, the resulting friction between the interface surfacesforms the locking layerthat maintains the locking structurein the locked state of.

While in the locked state of, tensile forces FT applied along the lengths of the barrier layers,are opposed by the frictional forces between the interface surfacesof the locking elements. Thus, the bladderis restricted from stretching or deforming around the wearer when the locking systemis in the locked state. When the wearer wishes to unlock the locking system, such as to loosen the article (e.g., shoe or clothing), the wearer increases the pressure within the interior voidof the bladderto move the first barrier layeraway from the second barrier layer(). Consequently, the interface surfacesof the respective first and second pluralities of the locking elementsdisengage from each other to allow the barrier layers,to stretch and deform.

With particular reference to, a locking structureis provided and includes the bladderand a locking systemdisposed within the bladder. In view of the substantial similarity in structure and function of the components associated with the locking structurewith respect to the locking structure, like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions are used to identify those components that have been modified.

Referring to, the locking systemb includes a plurality of locking elementsdisposed within the interior voidof the chamber. In this example, the plurality of locking elementsare only disposed on one of the inner surfaces,of the barrier layers,. As shown, the plurality of locking elementsare disposed on the inner surfaceof the first barrier layerin. In some implementations, the plurality of locking elementsare integrally formed with the inner surfaces,of the barrier layers,. In other implementations, the plurality of locking elementsare mechanically attached to the inner surfaces,of the barrier layers,(e.g., individually welded).

Unlike the example of, where the locking elementsare attached to each barrier layer,and each include the interface surfaceon one side, the locking elementsof the present example includes a pair of the interface surfacesdisposed on opposite sides of the locking element. Here, the locking elementsinclude a locking bodyincluding the interface surfacesdisposed on opposite sides of the locking body. The locking elementsalso include an anchordisposed at one end of the locking body. The anchorattaches to the inner surface,of one of the barrier layers,such that the locking bodyextends from the anchorto a free end disposed at an opposite end from the anchor.are illustrated with the locking elementsof, but may include any one or more of the other locking elements-as provided in.

While in a relaxed state (), the locking bodiesof adjacent ones of the plurality of locking elementsdisposed on the inner surfaceof the first barrier layerare arranged in a spaced apart manner to prevent direct contact between the interface surfacesof the plurality of locking elements. In this relaxed state, the locking structureis relatively flexible and can conform and stretch to fit a variety of geometries. When the pressure of the interior voidof the chamberis reduced from a first pressure (e.g., ambient) to a second pressure (e.g., below ambient), the inner surfaces,of the barrier layers,move toward one another to bring the plurality of locking elementsinto direct contact with one another at the interface surfaceswhere each locking elementin the plurality of locking elementsoverlaps adjacent locking elements. Thus, the interface surfaceon a first side of a first one of the locking bodyof one of the locking elementswill engage the opposing interface surfaceon the second side of the locking bodyof an adjacent one of the locking element. Once the plurality of locking elementsare in overlapping direct contact with one another at their respective interface surfaces, the resulting friction between the interface surfacesforms the locking layerthat maintains the locking structurein the locked state in.

Optionally, the locking systemshown inmay be provided in a force-responsive configuration that does not utilize vacuum. Here, the locking systemb is configured to lock in response to reactive forces applied to the locking systemby the foot. For example, during low-energy movements (e.g., walking) the elastic forces of the materials of the barrier layers,may bias the locking systemtowards a contracted, unlocked state. However, during high-energy movements (e.g., cutting, stopping, starting), the barrier layers,may stretch in response to forces applied to the shoe upper. As the barrier layers,are stretched around the foot, the locking elementsare collapsed upon each other to form a locking interface, thereby limiting the amount of stretch in the barrier layers,. Thus, unlike applications including a vacuum locking configuration, in which the locking systemis continuously locked under the force of vacuum, force-responsive configurations are tuned to lock in response to threshold forces caused by movements of the foot. The threshold forces for locking and unlocking the locking systemmay be turned by modifying the spacing, quantity, size, shape, and/or surface textures of the locking elements. Optionally, the locking systemmay be implemented on a single one of the barrier layers,or on another resilient substrate (e.g., an elastic fabric).

With particular reference to, a locking structureis provided and includes the bladderand a locking systemdisposed within the bladder. In view of the substantial similarity in structure and function of the components associated with the locking structurewith respect to the locking structure, like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions are used to identify those components that have been modified.

Referring to, in some implementations, the locking structureincludes a plurality of the locking elementsand a compressible componentdisposed within the interior voidof the chamber. The compressible componentis a transformable structure operable to transition between a relaxed state and a constricted state. Once in the constricted state, the plurality of locking elementsare operable to transition the locking structurebetween the unlocked state and the locked state. Accordingly, the plurality locking elementsand the compressible component, when disposed within the interior void, cooperate to transition the locking structurefrom a relaxed unlocked state, to a constricted unlocked state, to a constricted locked state.

In this example, the compressible componentincludes a collapsible lattice structurehaving a plurality of apertures or reliefs formed through a thickness of the compressible component. Generally, when a pressure within the interior voidof the chamberis reduced from a first pressure (e.g., ambient) to a second pressure, the lattice structureis configured to collapse within the chamberto transition the compressible componentfrom the unlocked and relaxed state () to the unlocked and constricted state (). When the pressure within the interior voidof the chamberis further reduced from the second pressure to a third pressure, the plurality of locking elementsare brought into contact to form the locking layerassociated with the locked state.

As shown, the compressible componentincludes a first surfaceon a first side of the compressible componentand a second surfaceon an opposite second side of the compressible component. A distance from the first surfaceto the second surfacedefines a thickness of the compressible component. As discussed in greater detail below, the compressible componentis operable to further transition the locking structurebetween a relaxed state () and a constricted state (). The compressible componentmay be formed of a resilient material, such as a foam material, which is configured to compress within the bladderas pressure within the interior voidis reduced and to bias the bladderback towards the expanded or relaxed state when pressure within the interior voidis increased.

One of the first surfaceand the second surfaceof the compressible componentmay be attached to one of the inner surfaces,of the barrier layers,when the locking structureis assembled. As shown, the second surfaceof the compressible componentis attached to the second inner surfaceof the second barrier layer. In some implementations, the second surfacemay be fully attached to the second inner surface. Thus, as the compressible componentmoves between the relaxed and constricted state, the compressible componentdirectly pulls the second barrier layerto transition the second barrier layerbetween a relaxed and constricted state. Whileshow the locking elementsdisposed between the compressible componentand the bladderas being attached to the first barrier layerof the bladdervia the anchors, it will be appreciated that the anchorsof the locking elementsmay alternatively be attached to first surfaceof the compressible component.

While in the relaxed state (), the plurality of locking elementsare disposed on the first inner surfaceof the first barrier layerand are arranged in a spaced apart manner to prevent direct contact between the interface surfacesof the plurality of locking elements. In this relaxed state, the locking structureis relatively flexible and can conform to a variety of geometries. When the pressure of the interior voidof the chamberis reduced from the first pressure (e.g., ambient) to the second pressure (e.g., below ambient), the compressible componentconstricts and pulls the attached second barrier layerto move the locking structurefrom the relaxed state to the constricted state (). In the illustrated example, the transition from the relaxed state to the constricted state is represented by a change in the overall length of the bladderfrom a first length Lin the relaxed state to a smaller second length Lin the constricted state.

Once in the desired constricted state, the pressure of the interior voidof the chamberis further reduced from the second pressure to a third pressure (i.e., a pressure below the second pressure) and the inner surfaces,of the barrier layers,move toward one another to bring the plurality of locking elementsinto direct contact with one another at the interface surfacesand with the first surfaceof the constricted compressible component. Each locking elementin the plurality of locking elementsoverlaps adjacent locking elements, and once the plurality of locking elementsare in overlapping direct contact with one another at their respective interface surfaces, the resulting friction between the interface surfacesforms the locking layerthat maintains the locking structurein the constricted state to the locked state (). Additionally, the interface surfacesof the locking elementsmay engage the first surfaceof the constricted compressible componentto maintain the compressible componentin the constricted state.