Title:
SELF-TAILORED INSOLE
Kind Code:
A1


Abstract:
Disclosed is a self-tailored insole. The self-tailored insole comprises: an inner sole; and a hard member, attached to a lower side of the inner sole, transformable depending on a morphology of a user's sole, said hard member comprising: a heel portion which has a curved portion configured to allow the inner sole to closely contact with and support left, right and rear sides of a heel of the user, and an arch portion configured to allow the inner sole to closely contact with and support arches of a sole of the user, said heel portion and said arch portion being formed as one body, thus preventing the heel and the arches from being abnormally distorted upon locomotion.



Inventors:
Bae, Jin Woo (Daegu, KR)
Kim, Seon Chil (Daegu, KR)
Application Number:
14/363908
Publication Date:
01/28/2016
Filing Date:
03/20/2014
Assignee:
FOOTHEALTH CO., LTD.
Primary Class:
International Classes:
A43B17/00; A43B7/28; A43B17/02
View Patent Images:
Related US Applications:
20100287789Cushioning mechanism for shoe midsoleNovember, 2010Mo et al.
20160345662SHOE SOLEDecember, 2016Rosa
20080016717BREATHABLE-WATERPROOF FOOTWEARJanuary, 2008Ruban
20110010964FOOTWEAR SUSPENSION SYSTEMJanuary, 2011Hardy et al.
20100307032FOOTWEAR WITH SHAPED SOLE SURFACEDecember, 2010Geer et al.
20060037217Side entry footwear and methods of makingFebruary, 2006Bernstein
20150272263Energy-Saving Wearable Piezoelectric Transportation DeviceOctober, 2015Szent-miklosy
20100139129TRACTION MEMBER FOR SHOEJune, 2010Kuhtz et al.
20060117609Sole for moving in particular on unstable surfaceJune, 2006Guichard
20020053148FOOTWEAR WITH LAST AREA SEALING AND METHOD FOR ITS PRODUCTIONMay, 2002Haimerl
20120233891BICYCLE CLEAT COVERSeptember, 2012Woodford



Primary Examiner:
MANGINE, HEATHER N
Attorney, Agent or Firm:
CANTOR COLBURN LLP (Hartford, CT, US)
Claims:
1. A self-tailored insole, comprising: an inner sole; and a hard member, attached to a lower side of the inner sole, transformable depending on a morphology of a user's sole, said hard member comprising: a heel portion which has a curved portion configured to allow the inner sole to closely contact with and support left, right and rear sides of a heel of the user, and an arch portion configured to allow the inner sole to closely contact with and support arches of a sole of the user, said heel portion and said arch portion being formed as one body, thus preventing the heel and the arches from being abnormally distorted upon locomotion.

2. The self-tailored insole of claim 1, wherein the arch portion is responsible for supporting an inner arch of the sole of the foot and has cut lines formed therein in the inward direction from an outer end thereof.

3. The self-tailored insole of claim 2, wherein each of the cut lines has a circular hole at the inner end thereof.

4. The self-tailored insole of claim 1, wherein the hard member has a cushioning member attached to a lower side of the heal portion.

5. The self-tailored insole of claim 2, wherein the hard member has a cushioning member attached to a lower side of the heal portion.

6. The self-tailored insole of claim 3, wherein the hard member has a cushioning member attached to a lower side of the heal portion.

Description:

TECHNICAL FIELD

The present invention relates to a self-tailored insole. More particularly, the present invention relates to a self-tailored insole, used between the bottom of a shoe and the sole of the foot to protect the sole of the foot, comprising a hard member which can be transformed depending on the morphologies of the foot, thus functioning to allow the user to have a correct standing posture, mitigate the fatigue of the foot by evenly distributing the weight of the user throughout the sole of the foot, prevent the user's foot from being distorted or taking incorrect steps upon locomotion, and induce the user to walk with a correct gait.

BACKGROUND ART

The human foot is an organ at the terminal portion of the leg which bears weight when the body stands or walks, and which allows forward or reverse locomotion. Particularly, the sole of a foot is called a microcosm of the body in Oriental medicine because all of the body organs are connected to the sole in acupuncture theory. Hence, even just walking is helpful for health.

However, correct gait and standing posture is important because if a person does not have correct gait or standing posture, an impact may be imposed on the joints and the backbone, resulting in injury.

Since persons generally wear shoes, the sole is not spontaneously impacted with the ground, with the consequent distortion thereof.

However, when wearing high-heeled shoes or using high heel inserts, a person is apt to form an incorrect gait or standing posture. In this condition, the body's weight is not evenly distributed over the sole, which may cause a foot disorder or give the person discomfort, ultimately having a bad influence on other body organs and eventually harming health.

These days, with an increasing interest in health, there is a strong demand on functional shoes that provide comfort to the foot.

Functional shoes are, however, generally very expensive due to their distinct characteristics, and thus are very restrictively utilized. As consumption goods, shoes impose a cost burden on the user at generally regular intervals of time. Hence, an increasing number of users want functional insoles which can be generally applied to shoes.

A functional insole is disclosed in Korean Patent Publication No. 10-2011-0019062 (Feb. 25, 2011).

The reference invention relates to a functional health footpad which can be inserted into shoes. The functional health footpad is described to exhibit excellent elastic restoring force without impairing the soft insole of the shoe and provide an arch structure of the foot without distortion, permanently free of deformation, whereby it can not only absorb shocks upon walks, but also functions to correct mal-transformed feet and wrong gait whenever walking.

This insole is configured to fix both the arches of the foot and the heel at correct positions and to induce the user to establish accurate gait, whereby a standing posture can be corrected and foot pains mitigated.

However, the conventional insole has a uniform shape, and thus is difficult to apply to varied foot shapes of all people.

As an alternative, insoles personalized to individuals have attracted great attention. A conventional personalized insole is described in Korean Patent Publication No. 10-2010-0065991 (Jun. 17, 2010).

This personalized insole comprises a base disposed on the bottom of a shoe, a moldable portion, overlying the base, capable of being molded according to the sole shape of the user, and a fabric layer, established on the moldable portion, which is to be in contact with the sole of the user, whereby the insole can be accurately fitted to the foot of the user.

Another personalized insole is found in Korean Patent Publication No. 10-2006-0109598 (Oct. 23, 2006).

This cited invention pertains to a method for manufacturing a personalized insole, in which a simpler process procedure, compared to conventional methods, is employed. By this method, a personalized insole can be more easily and quickly manufactured, with better economical advantage and effectiveness. This cited invention is characterized in that conventional manufacturing processes can be omitted or significantly simplified by use of convenient and semi-permanent casting tools, and semi-processed products.

However, because conventional inventions require the measurement of the foot shape of the user before the manufacture of the personalized insoles, they suffer from the disadvantage of inconvenience, a long period of time for manufacture, poor productivity, and cost increase.

DISCLOSURE

Technical Problem

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a self-tailored insole, comprising a hard member which can be transformed, depending on the weight of the user, so as to set the configuration of an inner sole within a short period of time according to the user's foot; and particularly, a hard member coupled to the lower side of an inner sole, in which a heel portion having a curved portion, and an arch portion are formed as one body, said heel portion being responsible for preventing the foot from being distorted by the pressure transmitted from the heel through the arches of the foot whenever the user walks, and for stably supporting both the heel and the arches of the foot, so as to induce the user to have a correct posture, said arch portion functioning to supporting both inner and outer arches of the foot.

In one embodiment of the self-tailored insole according to the present invention, the arch portion has cut lines formed therein in the inward direction from an outer end thereof, with a circular hole construction at the inner end of each of the cut lines, whereby the arch portion can prevent the sole of the foot from experiencing a pain upon locomotion, to support the arches of the sole of the foot in compliance with the motion of the foot during walking or running.

In another embodiment of the self-tailored insole according to the present invention, the hard member has a cushioning member attached to the lower side thereof, said cushioning member being designed to absorb the impact from the heel upon walking or running.

Technical Solution

In order to accomplish the above object, there is provided a self-tailored insole, comprising: an inner sole; and a hard member, attached to a lower side of the inner sole, transformable depending on a morphology of user's sole, said hard member comprising: a heel portion which has a curved portion configured to allow the inner sole to closely contact with and support left, right and rear sides of a heel of the user, and an arch portion configured to allow the inner sole to closely contact with and support arches of a sole of the user, said heel portion and said arch portion being formed as one body, thus preventing the heel and the arches from being abnormally distorted upon locomotion.

In the self-tailored insole according to the present invention, the arch portion is responsible for supporting an inner arch of the sole of the foot and has cut lines formed therein in the inward direction from an outer end thereof.

In the self-tailored insole according to the present invention, each of the cut lines has a circular hole at the inner end thereof.

In the self-tailored insole according to the present invention, the hard member has a cushioning member attached to a lower side of the heal portion.

Advantageous Effects

The self-tailored insole according to the present invention is characterized by a hard member in which a heel portion having a curved portion, and an arch portion are integrated, said the heel portion being configured to allow an inner sole to closely contact with and support left, right and rear sides of the heel, said arch portion being configured to allow the inner sole 10 to closely contact with and support the arch portion of the sole of the user, whereby the insole can protect the heel from an impact by guaranteeing the stable support of the heel, and can induce the user to walk with a correct gait by minimizing the distortion of the foot in the shoe upon locomotion.

Also, being transformable depending on the morphology of the sole of the user's foot, the hard member introduced to the self-tailored insole according to the present invention allows the insole to be personalized to all different individuals within a short period of time. Thus, it is free of the inconvenience of individual customization, and makes it possible to significantly reduce the production time, to allow for the mass production of insoles, and thus to decrease the production cost.

Further, the hard member of the self-tailored insole according to the present invention has an arch portion with cut lines, and functions to induce the user to take a correct posture by stably supporting arches of the user's foot and to significantly mitigate foot's fatigue by distributing the weight.

The insole of the present invention mitigates the pain or load caused by the pressure of the arch portion of the shoes whenever locomotion takes place, and stably supports the arches of the foot even if the foot moves in a rotational direction during locomotion, thereby inducing the user to walk with a correct gait. Also, use of the insole does not discomfort the user.

Provided with a cushioning member at a lower side of the heel portion, the self-tailored insole according to the present invention can reduce the impact from the heel, and thus can be generally applied to various shoes including hiking boots, running shoes, etc.

DESCRIPTION OF DRAWINGS

FIG. 1 is an anatomical view illustrating a structure of the foot.

FIG. 2 is a perspective view of a self-tailored insole according to the present invention.

FIG. 3 is side view of the self-tailored insole according to the present invention, with a partially enlarged cross sectional view taken from the circle.

FIG. 4 is a bottom view of the self-tailored insole according to the present invention.

FIG. 5 shows a rear view of the self-tailored insole according to the present invention, and a perspective view, a cross sectional view, and a modified example of a cushioning member according to the present invention.

<Description of the Reference Numerals in the Drawings>
10: inner sole11: mesh layer
12: cushioning sheet layer13: EVA sheet layer
14: spilehole
20: hard member21: heel portion
21A: curved portion21B: shielding groove
22: arch portion22A: cut lines
22B: circular hole
30: cushioning member31: body
31A: microhole31B: shielding protrusion
32: coupling protrusion33: cushioning protrusion
34: air cushioning layer39: elastic body

BEST MODE

The present invention will now be described in detail based on aspects (or embodiments). The present invention may, however, be embodied in many different forms and should not be construed as being limited to only the embodiments set forth herein, but should be construed as covering modifications, equivalents or alternatives falling within ideas and technical scopes of the present invention.

In the figures, like reference numerals, particularly, tens and units, or reference numerals having like tens, units and letters refer to like elements having like functions throughout, and unless the context clearly indicates otherwise, elements referred to by reference numerals of the drawings should be understood based on this standard.

Also, for convenience of understanding of the elements, in the figures, sizes or thicknesses may be exaggerated to be large (or thick), may be expressed to be small (or thin) or may be simplified for clarity of illustration, but due to this, the protective scope of the present invention should not be interpreted narrowly.

The terminology used herein is for the purpose of describing particular aspects (or embodiments) only and is not intended to be limiting of the present invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,”, “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For the convenience of an explanation of the self-tailored insole according to the present invention, general directions, but not exact, are determined with reference to

FIG. 5. In this regard, up-, down-, left- and rightward directions are determined as viewed in FIG. 5, with the direction of gravity defined as the downward direction. The heel portion accommodating the heel of the user is determined as a rear side to determine the front side and the rear side.

Prior to the description of the present invention, the structure of the foot is, as shown in FIG. 1, divided into a fore-foot section including toes, a mid-foot section including an inner arch upwardly curved inside the foot on the basis of the instep and the soles of both feet, and an outer arch upwardly curved outside the foot on the basis of the instep and the soles of both feet, and a rear-foot including the heel.

With regard to the structure of the insole shown in FIG. 5, the side where the arch for supporting the center of the sole of the foot is present is defined as an inside while the opposite side to the inside is determined as outside.

By dictionary definition, an inner sole, a footpad, and an insole are the same in meaning. For the convenience of description, all of conventional inserts for shoes are referred to as footpads while the structure to be inserted into a shoe in accordance with the present invention is defined as an insole, and the insole structure including fabric sheet layers, but devoid of the hard member, is called an inner sole, but these definitions are not intended to limit the scope of the present invention at all.

Below, a description will be given of the self-tailored insole according to the present invention with reference to the accompanying drawings.

As shown in FIGS. 2 to 4, the self-tailored insole according to the present invention comprises:

an inner sole 10; and

a hard member 20, attached to the lower side of the inner sole 10, transformable according to the user's sole, wherein said hard member comprises:

a heel portion 21 which has a curved portion 21A configured to allow the inner sole 10 to be in close contact with and support left, right and rear sides of the heel, and

an arch portion 21 configured to allow the inner sole 10 to be in close contact with and support the arch portion of the sole of the user.

The term “arch of the sole of the foot” is intended to encompass both the inner arch and the outer arch which are present, respectively, inside and outside the foot on the basis of both feet which are put side by side, so that the inner arch of one foot is opposed to its counterpart of the other foot while the outer arch is not opposed to its counterpart of the other foot.

The inner sole 10 is cut to a predetermined size of the user, and bonded onto the hard member 20.

As shown in the partial cross sectional view of FIG. 3, the inner sole 10 has a tri-layer structure composed of a mesh layer 10 to be in contact with the foot of the user, a cushioning sheet layer 12, and an EVA (ethylene vinyl acetate) sheet layer 13.

The mesh layer 11 may be composed of a fabric material which is usually used in conventional inner soles.

In addition, the mesh layer 11 may be supplemented with silver fibers to effectively remove foot odor.

The cushioning sheet layer 12 is made of OrthoLiite to absorb a shock from the sole of the foot.

“OrthoLite,” a well-known material used in insoles for shock absorption, is an open cell foam with excellent restoring force and shock absorption. Particularly, it is highly breathable, allowing air to circulate in and around the insole, preventing the presence of foot odor. In addition, the open cell foam maintains resistance to compression with time, guaranteeing far better cushioning and fit inside the shoe, compared to conventional simple fabric insoles. Accordingly, it is utilized in various functional shoes including hiking boots, running shoes, etc.

Turning now to the EVA sheet layer 13, it is made of a synthetic ethylene acetate vinyl resin. This layer contains micropores therein, and provides plasticity, stress cracking resistance, and impact resistance, functioning to cushion a shock and comfort the foot via the inner sole 10.

Depending on the manufacturer's choice, the EVA sheet layer 13 may be substituted by a non-woven fabric layer, a urethane layer or a latex layer.

A plurality of spileholes 14 may be formed across or in a part of, for example, the upper or lower side of the inner sole 10 to absorb and discharge sweat from the user and thus to keep the foot cool inside the shoe.

Both the mesh layer 11 of a fabric material and the cushioning sheet layer 12 of OrthoLight are provided with micropores while spileholes 14 are perforated in the lower side of only the EVA sheet layer 13 in one embodiment of the present invention, as shown in FIG. 5.

The hard member 20 functions to support both a mid-foot portion in which the arches are formed and a rear-foot portion including the heel.

In this regard, the hard member 20 is formed beneath a part of the inner sole 10 preferably by injection molding of high strength thermoplastic or thermosetting resin, or both.

In one preferred embodiment, the material of the hard member may be an engineering plastic made of a mixture of polyamide (PA) and nylon 66.

The hard member 20 comprises a heel portion 21 for supporting the heel of the user, and an arch portion 22 for supporting both the longitudinal inner arch and the outer arch which are present, respectively, inside and outside the foot on the basis of both feet which are put side by side.

To support and hold the inner and outer arches of the foot, the arch portion 22 is formed at slant angles.

Because the slant angle of the inner arch is greater than that of the outer arch, the arch portion may be formed corresponding to the morphology.

The heel portion 21 has a curved portion 21A which runs to a predetermined distance in a curved upward direction to support and fix the opposite lateral sides and the rear side of the heel.

When a user wears a shoe provided with the insole, the weight of the user is spontaneously compressed on the mesh layer 11 of the insole throughout the sole of the foot.

In this condition, the arch portion 22 is transformed to fit with the arch morphology of the foot, thus stably supporting the foot of the user.

In addition to keeping the inner sole 10 in the morphology of the heel, the curved portion 21A protects the heel from an impact by guaranteeing the stable support of the heel due to the intensity of the hard member 20, and induces the user to walk with a correct gait by minimizing the distortion of the foot in the shoe upon locomotion.

Moreover, the arch portion 22 supports the arches of the foot in their original forms, thereby solving the problem of incorrect walking and standing postures which have arisen as the inner and outer arches and the heels of both feet are distorted to decrease weight distribution and thus to lean the weight in one direction (particularly in the direction of the inner arch).

Particularly, the heel portion 21 and the arch portion 22 are formed as one body in the hard member, so that when the user walks, the hard member can prevent the heel and the arches from being abnormally distorted by the pressure transmitted from the heel through the inner and outer arches to the toe of the fore-foot.

Therefore, the self-tailored insole of the present invention can significantly mitigate the fatigue of the foot and the load imposed on the joint even when standing or locomotion for a long period of time because the hard member 20 in which the arch portion 22 and the heel portion 21 having the curved portion 21A are molded into one body evenly distributes the weight of the user throughout the sole of the foot to prevent the three-face contact structure which only the sole of the human foot have from being distorted by the shoe.

Also, the present invention readily allows for an ergonomic design to fit to the foot of the user, dissolving the cost burden and production inconvenience of self-tailored shoes.

In order to stably support the foot of the user and facilitate the production thereof, the hard member 20 in which the arch portion 22 and the heel portion 21 are integrated may be formed by injection molding.

After the injection molding, the hard member 20 may be pressed against the inner sole 10 to allow the arch portion 22 and the heel portion 21 to form predetermined slant angles, with the consequent attachment of the hard member 20 to the inner sole 10.

Alternatively, the injection molding of the hard member 20 may be performed in such a manner that the arch portion 22 and the curved portion 21A of the heel portion 21 form predetermined slant angles, followed by bonding the hard member 2 to the lower side of the inner sole 10.

Generally, a resin molded product accounting for the arch portion 22 and the heel portion 21 bears certain strength. In this state, when the upper end compresses the foot in contact therewith, a pain or inconvenience may be caused whenever locomotion undertaken.

The hard member 20 according to the present invention is characterized by the formation of cut lines 22A in the arch portion 22 in the inward direction from an outer end whereby the arch can be prevented from experiencing a burden or pain caused when the hard member functions to protect the inner arch of the foot of the user the slant angle of which is low.

The cut lines 22A are formed by partially cutting the body of the hard member 20. Given the cut lines, the arch portion 22, which is responsible for the constitutive, stable support of the inner arch of the foot of the user, can be variably transformed depending on the morphologies of the foot during walking, and thus support the arch without causing discomfort to the user.

Since the hard member 20 is deformed depending on the arch's shape during walking, stress may be accumulated at the inner ends of the cut lines 22A after a long time of walks and thus may be apt to destroy the hard member 20.

In one embodiment of the present invention, a circular hole 22B the diameter of which is greater than the width of the cut lines 22A is formed at the inner end of each of the cut lines 22A to relieve the stress caused by the displacement of the arch portion 22 during walking, thereby preventing the destruction of the hard member 20.

Next, the heel of the user exhibits relatively small change morphological during walking. On the other hand, since the heel is in constitutive contact with the insole, it is likely to suffer from a pain by rubbing. In one preferred embodiment of the present invention, the inner sole 10 further extends upwards from the upper end of the heel 21 so that it prevents the heel from experiencing pain caused by rubbing.

When the extended portion 15 of the inner sole 10 is formed, a step may be formed as a result of inconsistency between ends of the hard member 20 and the inner sole 10 and gives discomfort to the user. In the present invention, the edge of the hard member 20 is buried in the inner sole 10 before attachment therebetween.

In addition, the extended portion 15 of the inner sole 10 may be formed only on the heel portion 21 or over the whole hard member 20.

Further, the self-tailored insole of the present invention may be provided with a cushioning member 30 at the lower side of the heel portion 21.

The cushioning member 30 may be made of an elastic synthetic resin, such as a non-woven fabric, latex, or an elastomer, and functions to absorb the shock transmitted to the heel.

In one embodiment of the present invention, the lower side of the hard member 20 may have a circular hole (not shown) to which the cushioning member 30 is attached in such a manner that a part of the cushioning member 30 is buried in the hard member 20.

In the present invention, an impact is absorbed by both the cushioning member 30, and the inner sole 10 composed of a bilayered cushioning sheet layer 12 and an EVA sheet layer 13 before transmission to the sole of the foot. Hence, the present invention is applicable to various shoes including sneakers, running shoes, hiking boots, etc. According to the kind of shoes, their shock absorption may be determined.

In one embodiment of the present invention, a double cushioning design may be established in the cushioning member 30 to increase the generality of the insole, which guarantees high shock absorption ability irrespective of the kind of shoes.

To this end, the cushioning member 30 has a body 31 resembling a plate, as shown in FIG. 4. Within the body 31, a plurality of coupling protrusions 32 stands upright on the side wall.

The coupling protrusions 32 are fitted to holes formed on the bottom of the hard member 20, so that the peripheral contact part of the body 31, and the coupling protrusions make sure of the attachment of the cushioning member 30 to the hard member 20.

Moreover, the body 31 has a round, flat central bottom and a wall extending at a slightly slant angle from the bottom to the edge. Bar-type protrusions 33 are radially formed in the central bottom area while the coupling protrusions 32 are provided on the slightly slant wall.

Accordingly, when the plate-like cushioning member 30 is assembled to the hard member 20, an air cushioning layer 34 is spontaneously constructed, functioning to primarily absorb the impact transmitted from the heel portion 21.

If the intensity of the impact exceeds the coverage of the air cushioning layer 34, the impact brings the hard member 20 into contact with the bar-type protrusions 33 so that it can be secondarily absorbed due to the elasticity of the bar-type protrusions.

Also, the elasticity of the body 31 of the cushioning member 30 is a third factor for absorbing the impact.

As described above, the present invention establishes multi-step shock absorption mechanisms including the cushioning member 30 with various cushioning structures, and the inner sole 10 with a laminated structure for shock absorption, so that the insole of the present invention can safely absorb shock to protect the sole of the foot and the joint from impact during locomotion. Therefore, the insole of the present invention may bring about an economical profit because it can be used instead of expensive functional shoes.

In one preferred embodiment of the present invention, the cushioning member may be provided at its central bottom with a microhole 31A for the air circulation of the air cushioning layer 34.

Also, as shown in FIG. 4, the cushioning member may be provided with an elastic body 39 within the air cushioning layer 34. The elastic body 39 is partially responsible for shock absorption while allowing the air cushioning layer 34 to restore within a short period of time to cope with the successive generation of impacts.

The elastic body may be a coil spring established along the circumference of the coupling protrusion.

A next description is given of an air shield provided for the cushioning member.

The cushioning member 30 is generally bonded to the lower side of the heel portion 21 of the hard member 20 via an adhesive. After a long-term use, the air tightness maintained by the bonding force decreases so that the air contained within the air cushioning layer may be drained through gaps, leading to a decrease in shock absorption.

In one embodiment of the present invention, an air shield is introduced to the contact face between the hard member 20 and the cushioning member 30 to prevent the functional deterioration of the air cushioning layer 34.

As shown in the partially enlarged view of FIG. 4, the air shield includes a shielding protrusion 31B formed along the upper edge of the cushioning member 30, and a shielding groove 21B formed in correspondence with the shielding protrusion 31B in the lower side of the heel portion 21 of the hard member 20.

The shielding groove 21B is established in an up- and outward direction in the lower side of hard member 20, and the shielding protrusion 31B is fitted to the shielding groove 21B.

The shielding protrusion 31B includes a flange 31Bb formed along the upper end of the body 31 of the cushioning member 30, and a shielding wing 31Ba bent in a down- and inward direction from the end of the flange, with the formation of air tight layer 31C between the flange 31Bb and the shielding wing 31Ba.

Since the cushioning member 30 is made of an elastic material as described above, it may be forcibly fitted into the shielding groove 21B upon the first setting.

In this structure, the air tight layer 31C of the shielding protrusion 31B surrounds the air cushioning layer 34 and is formed in correspondence with the shape of the shielding groove 21B. Given an impact, the air within the air cushioning layer 34 may be discharged through an interface between the cushioning member 30 and the hard member 20, but not through the microhole 31A. Under this condition, the air tight layer 31C is expanded in an outward direction by the pressure of the discharging air to push the flange 31Bb and the shielding wing 31Ba into the inner side of the shielding groove 21B.

Accordingly, the air shield is configured to block the air discharge of the air cushioning layer 34 via the interface between the cushioning member 30 and the hard member 20, thereby preventing a decrease in cushioning function.

Although the preferred embodiments of the present invention have(has) been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.