FOOTWEAR ARTICLE

The footwear article comprises a generally elongate sole having a first portion for interaction with a ground surface during ambulation, a second portion for interaction with the ground surface during ambulation, and a third portion between the upper surface and the lower surface. The first portion includes a first material with a first material property, the second portion includes a second material with a material property, and the third portion includes a material with a third material property. The first and portions extend to the upper surface of the sole. The first material property provides dampening of impact load imparted to the foot of the person upon contact of the footwear article with the ground surface. The third material property is a visco-elastic property for providing controlled deformation upon contact of the footwear article with the ground surface and returns to an initial state upon removal of the impact.

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Description
FIELD OF THE INVENTION

The present invention relates to the field of footwear articles, in particular to footwear of composite form.

BACKGROUND OF THE INVENTION

It is well known in the art that shock loadings and forces applied to the underside of the foot of a person via the sole of footwear article have long term effects on the integrity of joints of a person, whilst also at times causing pain and discomfort, in particular when wearing footwear for extended periods of time.

Furthermore, it is well known that the majority of loading on impact to the foot of a person is imparted to the underside of the heel portion of the foot of a person in use.

Footwear articles of the prior art include various manners in which to increase comfort and conformity to the foot of user, including shock absorptive inserts, various types of foam rubber and air cushioning devices. Such footwear articles typically require increased manufacturing costs and tooling, thus increasing complexity of production.

The present invention is provides a footwear article which overcomes or at least substantially ameliorates at least some of the deficiencies as exhibited by those of the prior art.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a footwear article comprising:

a generally elongate sole for engagement with and support of the foot of a person, said sole having an upper surface, a lower surface, a first portion being for interaction with at least the heel region of the foot of the person, a second portion for interaction with at least a ground surface during ambulation, and a third portion disposed between the upper surface and the lower surface; and

a foot engagement means for securing the footwear article to the foot of a person.

characterised in that a first portion of the sole includes a first material having a first material property, the a second portion of the sole includes a second material having a second material property, and the third portion of the sole includes a third material having a third material property,

said first portion and said second portion extend at least to the upper surface of the sole, the first material property provideing for dampening of impact load imparted to the foot of the person upon contact of the footwear article with a ground surface, and the third material property being a visco-elastic property for providing controlled deformation upon contact of the footwear article with a ground surface and return to an initial state upon removal of said impact.

The third portion may extend substantially the length of the sole and substantially the width of the sole.

The visco-elastic property of the third portion may be non-uniform laterally. The visco-elastic property material of the central portion of the third portion may deform in a manner greater than the medial and lateral portions of the third portion so as to oppose lateral movement of the foot of the person with respect to the sole during ambulation.

The visco-elastic property of the third portion is non-uniform longitudinally.

Preferably, the second portion provides for interaction with at least the metatarsal region of the foot of the person.

Preferably the first portion further provides for interaction with and at least partial support of the plantar arch of the user.

Preferably the first portion extends substantially laterally across the sole.

Alternatively, the first portion is provided as a first part and a second part and laterally spaced apart such that the first part provides for interaction with the lateral inferior of the heel of the person and the second part provides for interaction with the medial inferior aspect of the heel of the user. The first part and the second part of the first portion are preferably sized and selected from a material so as to provide lateral stabilisation and load distribution of the heel of the person.

The first material property and the second material property may differ from each other and the first material and the second material may differ from each other, and the first material and the second material have differing densities.

The first portion and the second portion are preferably selected from the group including polymeric materials, rubbers, elastomers and organic materials or combinations thereof.

Preferably the first material and the second material are selected from the group including thermoplastic polymeric material, co-polymers and mixed polymer blends.

The first material and the second material are preferably selected from the group including polyurethane, ethylene vinyl acetate, poly vinyl acetate and the like.

The first material and the second material may be provided in the form of expanded form, compact form or gel form of combinations thereof.

Preferably the first material is a polyurethane gel and the second material is an expanded poly vinyl acetate material.

Preferably, the first material is a polyurethane gel and the second material is an expanded polyurethane.

Preferably the third portion is provided as a shape memory expanded polymer and the viscosity of and density is selected such that the third portion in conjunction with the third material property provides said visco-elastic property. Preferably the third material is polyurethane.

The third portion may be provided in the form of interconnected deformable sub-portions. Alternatively, the third portion may be provided in the form of discrete deformable sub-portions.

Preferably, the third portion is provided as an expanded shape memory sponge construct.

Preferably, the sub-portions have a geometry which is partially spherical.

The engagement means is preferably selected from the group including straps, an enclosure, a buckle or the like.

Preferably the sole is formed as a unitary construct by co-molding the first portion and the second portion, with the third portion encapsulated within the sole. The sole is preferably formed as a unitary construct whereby the first portion and the second portion are joined together by an adhesive bonding agent, contact cement pressure or heat activated film or the like.

The upper surface of the sole is preferably provided as a substantially continuous surface and formed by at least part of the first portion and the second portion of the sole, and the first portion preferably extends partially towards the lower surface of the sole. Alternatively, the first portion may extend through the sole to the lower surface of the sole.

The upper surface is preferably of concave form and the sole includes a peripheral lip extending at least partially along the periphery of the sole so as to provide a contoured upper surface configured to receive the underside of the foot of the person.

The first portion of the sole may be provided as a multi-layered gel construct.

The sole may further include a fourth portion which extends to the upper surface of the sole and having material property provides for dampening of load imparted to the foot of the person upon contact with a surface, said third portion providing for interaction with at least the metatarsal region of the foot of the person.

Preferably the footwear article is provided is substantially non-enclosed, more preferably in the form of a “flip-flop” type footwear article. Alternatively, the article may be provided in the form of a “sandal” type footwear article, or as an at least partially enclosed footwear article.

Alternatively, the article may be provided as a heeled article such that the upper surface of the sole is inclined in a direction of from the upper surface towards the lower surface in a direction of from the first portion towards the second portion, and the third portion is located in a portion to substantially prevent or reduce movement of the foot of the person along the upper surface of the sole. The fourth portion may be located so as to be at adjacent the ball of the underside of the foot of the person.

Preferably, said first material is a gel type polymeric material and said second material is an expanded polymeric material, the sole is preferably formed as a unitary molded structure, and said first portion and said second portion co-operatively form a flexible sole.

Preferably a part of the first portion and a part of the second portion form the upper surface of the sole.

In a second aspect, the present invention provides a footwear article comprising:

a generally elongate sole comprising a first portion, a second portion and a third portion and having an upper surface and a lower surface,

said first portion being for direct contact and interaction with at least a portion of the underside of the foot of the person and being formed from a first polymeric material having a first density;

said second portion forming substantially the entire lower surface of the footwear article and being for direct contact and interaction with a ground surface and being formed from a second polymeric material having a second density; and

said third portion being disposed between the upper surface and the lower surface, and being formed from a third polymeric material, wherein said third

a generally elongate and flexible foot engagement means for securing the footwear article to the foot of a person, said foot engagement being engaged directly with at least said second portion and configured so as to extend over a portion of the upper side of the foot of the person;

wherein the first polymeric material and the second polymeric material are selected and the first portion and the second portion are sized and arranged such that the sole is substantially flexible and elastic so as to allow for substantial flexion of the sole longitudinally and return, when in use and during ambulation of the person;

wherein the first polymeric material and the second polymeric material are selected and the first portion and the second portion are sized and arranged such that dampening is provided upon load being imparted to the foot of the person upon contact with the surface;

wherein the third material property is a visco-elastic property for providing controlled deformation upon contact of the footwear article with a ground surface and return to an initial state upon removal of said impact; and

wherein the sole is formed as a unitary construct by co-molding the first portion and the second portion together with the third portion encapsulated within the sole, and the first polymeric material and the second polymeric material are suitably selected for said co-molding.

The first density is preferably greater than the second density, and the first material is preferably provided in a gel form and the second polymeric material is preferably provided in an expanded form.

In a preferred embodiment, the foot engagement means is a “thong” type engagement means, and the footwear article is provided in the form of a “flip-flop” type footwear article.

The third portion may extend substantially the length of the sole and substantially the width of the sole.

The visco-elastic property of the third portion is non-uniform laterally or non-uniform longitudinally.

The visco-elastic property of the central portion of the third portion may deform in a manner greater than the medial and lateral portions of the third portion so as to oppose lateral movement of the foot of the person with respect to the sole during ambulation. The first polymeric material and the second polymeric material may be selected from the group including thermoplastic polymeric materials, co-polymers and mixed polymer blends, more preferably from the group including polyurethane, ethylene vinyl acetate, poly vinyl acetate and the like.

In a preferred embodiment, the first material is a polyurethane gel material and the second material is an expanded polyurethane material.

The third portion may be provided as a shape memory expanded polymer and the viscosity of and density is selected such that the third portion in conjunction with the third material property provides said visco-elastic property. Preferably, the third material is polyurethane.

The third portion may be provided in the form of interconnected deformable sub-portions. Alternatively, the third portion may be provided in the form of discrete deformable sub-portions.

Preferably, the third portion is provided as an expanded shape memory sponge construct.

Preferably, the sub-portions have a geometry which is partially spherical.

The first portion may extend substantially laterally across upper surface of the sole and substantially form the rear part of the upper surface of the sole, and the second portion may form at least a part of the front part of the upper surface of the sole.

Alternatively, the first portion may form at least part of the front part of the upper surface of the sole, and the second portion may form at least a part of the rear part of the upper surface of the sole.

In an alternate embodiment, the first portion may form substantially the entire upper surface of the sole

The first portion may further provide for interaction with and at least partial support of the plantar arch of the user.

In other embodiments, the first portion may be provided as a first part and a second part and laterally spaced apart such that the first part provides for interaction with the lateral inferior of the metatarsal region of the foot of the person and the second part provides for interaction with the medial inferior aspect of the metatarsal region of the foot of the person. The first part and the second part of the first portion may be sized and selected from a material so as to provide lateral stabilisation and load distribution of the heel of the person.

In further embodiments, the upper surface may be of concave form and the sole may include a peripheral lip extending at least partially along the periphery of the sole so as to provide a contoured upper surface configured to receive the underside of the foot of the person.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will be explained in further detail below by way of examples and with reference to the accompanying drawings, in which:

FIG. 1a is a plan view of an exemplary embodiment of a footwear article according to the present invention;

FIG. 1b is a side view of the embodiment of the invention as depicted in FIG. 1a;

FIG. 1c is an enlarged side view of a portion of the embodiment of FIGS. 1a and 1b, in a partially deconstructed arrangement;

FIG. 1d depicts the embodiment of the footwear article of FIG. 1a in a flexed state;

FIG. 2a shows an exemplary embodiment of a third portion of the article according to the present invention;

FIG. 2b shows a cross-sectional view through the embodiment of FIG. 2a through the line E-E;

FIG. 2c shows a further exemplary embodiment of a third portion of the article according to the present invention;

FIG. 2d shows a cross-sectional view through the embodiment of FIG. 2c through the line F-F.

FIG. 3a depicts a cross-sectional view of a first schematic representation of a footwear article according to the present invention;

FIG. 3b depicts a cross-sectional view of a second schematic representation of a footwear article according to the present invention;

FIG. 3c depicts a cross-sectional view of a third schematic representation of a footwear article according to the present invention;

FIG. 3d depicts a cross-sectional view of a fourth schematic representation of a footwear article according to the present invention;

FIG. 3e depicts a cross-sectional view of a fifth schematic representation of a footwear article according to the present invention;

FIG. 3f depicts a cross-sectional view of a sixth schematic representation of a footwear article according to the present invention;

FIG. 3g depicts a cross-sectional view of a seventh schematic representation of a footwear article according to the present invention;

FIG. 3h depicts a cross-sectional view of the first schematic representation of the footwear article of the present invention along the line A-A;

FIG. 3i depicts a cross-sectional view of the third schematic representation of the footwear article of the present invention along the line B-B;

FIG. 3j depicts a cross-sectional view of the second schematic representation of the footwear article of the present invention along the line C-C;

FIG. 3k depicts a cross-sectional view of the seventh schematic representation of the footwear article of the present invention along the line D-D;

FIG. 4a is a plan view of another exemplary embodiment of a footwear article according to the present invention;

FIG. 4b is an underside view of the embodiment of the invention as depicted in FIG. 4a;

FIG. 4c is a side view of the embodiment of the invention as depicted in FIGS. 4a and 4b;

FIG. 5a is a plan view of another schematic representation of an embodiment of the present invention;

FIG. 5b is a plan view of a further second schematic representation of an embodiment of the present invention;

FIG. 5c is a plan view of yet another schematic representation of an embodiment of the present invention;

FIG. 5d is a plan view of yet a further schematic representation of an embodiment of the present invention;

FIG. 6a is a plan view of a first schematic representation of yet another embodiment of the present invention;

FIG. 6b is a plan view of a second schematic representation of yet a further embodiment of the present invention;

FIG. 6c is a plan view of a third schematic representation of still a further embodiment of the present invention;

FIG. 7a depicts yet still another embodiment of a footwear article according to the present invention;

FIG. 7b depicts yet still a further embodiment of a footwear article according to the present invention;

FIG. 8 depicts an alternate embodiment of a footwear article according to the present invention; and

FIG. 9 depicts yet an alternate embodiment of a footwear article according to the present invention.

 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1a to 1d show an exemplary embodiment of a footwear article 100 according to the present invention is shown. In the present embodiment, the footwear article 100 is provided in the form of a “flip-flop” type article, however other articles or other or alternate embodiments are also applicable to the invention, such as a sandal, slip-on type shoes or the like.

The article 100 is provided as a generally elongate sole 110 which, in the present invention, is provided as three portions, a first portion 116, a second portion 118, and a third portion 115 disposed between the first portion and the second portion although those skilled in the art will appreciate that the article 100 may be provided as further portions without departing from the invention.

A foot engagement means 120 is provided which is provided so as to co-operatively secure the article 100 to the foot of a person. Although depicted as a typical “flip flop” engagement device, those skilled in the art shall appreciate that other engagement devices such as straps, buckles, cross-overs or the like are equally applicable to the invention. Co-operatively with the sole 110, the engagement means 120 secures the article 100 to the foot of a person.

The engagement means 120 is affixed to the sole 110 of the article via apertures extending through the sole 110, the engagement means 120 having formations for abutting against and within recesses within the underside 114 of the sole 110. Again, those skilled in the art will understand that various engagement means may secured to the sole 110 in other manners where applicable.

The first portion 116 is positioned and formed from a material suitable for providing cushioning or dampening to the heel of a person when standing or during walking. The second portion 118 provides for support of the front portion or metatarsal portion of the foot of a person.

The third portion 115 has visco-elastic properties for providing controlled deformation upon contact of the footwear article with a ground surface and return to an initial state upon removal of said impact.

The first portion 116 of the sole 110 is formed from a gel-type polymeric material, in the present embodiment a polyurethane gel material, which provides for cushioning and shock absorption to the heel portion of a user.

The second portion 118 of the sole 110 is formed from a further polymeric material, in the present embodiment expanded polyurethane, which is integrally formed with the first portion 110. The second portion of the present embodiment forms the majority of the sole, the flexural properties in conjunction with suitable sizing provides for significant flexing of the sole when walking and again increases comfort to a use.

In the present embodiment 100, the third portion 115 extends substantially the length of the sole and substantially the width of the sole. However, as will be appreciated by those skilled in the art, in other or alternate embodiment, the visco-elastic property of the third portion is non-uniform laterally and may vary laterally.

For example, the visco-elastic property of the central portion of the third portion may deform in a manner greater than the medial and lateral portions of the third portion so as to oppose lateral movement of the foot of the person with respect to the sole during ambulation.

This can provide a degree of assistance in preventing or at least partly ameliorating the incidence of a person walking off the medial or lateral side of the footwear article. This may provide advantages orthotically as well as provide more even distribution of wear of the heel portion of the article, hence increasing and enhancing product longevity. As will also be appreciated, third portion and hence visco-elastic properties may be non-uniform longitudinally, depending upon the physical requirements of the article.

In a preferred embodiment such as that of the present embodiment, the third portion is provided as a shape memory expanded polymer and the viscosity of and density is selected such that the third portion in conjunction with the third material property provides said visco-elastic property. preferably, the third material is polyurethane.

In the present embodiment of the article 100, the first portion 116 and the second portion 118 are integrally formed by a co-molding process, whilst the third portion 115 is located within the mold so as to be encapsulated within the sole 110 of the article 100.

Further, such a co-molding process so as to provide continuity between the portions 116 and 118, and results in an interphase between the first portion 116 and the second portion 118, rather than an interface. Such a process of formation provides a suitably strengthed bond between the first portion 116 and the second portion 118.

A co-molding process, as will readily be understood by those skilled in the art, is whereby the portions are molded together and are generally formed with a common mold.

By being formed as a co-molded sole 110, the present invention provides for continuity of the sole 110 to be formed as a unitary construct, allowing for ease of form and providing for continuity of the upper surface 112 of the sole, thus allowing for direct contact of the underside of the foot of a user and also provides for ease of formation and manufacturing. Further, by providing a unitary construct such that the sole 110 is substantially formed in total by the first portion 116 and the second portion 118, ease and simplicity of formation and manufacture is achieved.

In other or alternate embodiments, the sole 110 may be formed by adhering the first portion 116 and the second portion 118 together by adhesives, pressure or heat sensitive glues or the like, where applicable.

Although in the present embodiment, the first portion 116, the second portion 118 are formed from a polyurethane gel, an expanded polyurethane material and a shape memory polyurethane visco-elastic material, respectively, those skilled in the art that other polymer or thermoplastic materials may also be utilised, such as poly vinyl acetate materials or other such suitable polymeric materials.

Alternatively, in other embodiments and as would be understood by those skilled in the art, other materials such as rubbers, elastomers, organic materials or combinations thereof, and co-polymer and mixed polymer blends and combinations thereof may also be utilised. Further, materials may be provided in the form of compact polymers, expanded polymeric materials or gel materials or combinations thereof and may be used in various combinations without departing from the scope of the invention. Furthermore, the sole 110 may be provided as a single material having varying densities so as to provide a first portion with appropriate cushioning whilst being of a expanded form for example for other parts of the sole so as to provide for structural integrity.

In other embodiments, cushioning elements such as “air cushioning” elements may be incorporated within the sole to provide for additional cushioning to the foot of a user.

Referring to FIG. 2a and FIG. 2b, Referring to FIGS. 2a-2d, there are shown schematic exemplary embodiments of a third portion 200a, 200b, in accordance with the present invention. The third portion 200a, 200b may be provided as a polymeric sheet, or any other membrane with suitable visco-elastic deformable portions 210a, 210b, which, as depicted, are interconnected by a membrane 220a, 220b.

As will be appreciated by those skilled in the art, numerous embodiments and materials or constructs may be applicable, to provide the visco-elastic properties in accordance with the requirements for the third portion 200a, 200b, in accordance with the present invention.

Preferably, the third portion 200a, 200b, is provided as an expanded shape memory sponge type construct, for example, an expanded polyurethane material. Again, those skilled in the art will appreciate that any similar such suitable material for providing the requisite visco-elastic properties is equally as applicable to the present invention.

Referring to FIGS. 3a-3g, there are shown cross-sectional schematic views of a number of alternate exemplary embodiments of a footwear article 300a-300g according to the present invention, these embodiments 300a-300g include a third portion 310a-310g being formed of different geometries depending upon the particular requirements and requisite physical properties of the article 300a-300g.

As will be noted and appreciated by those skilled in the art, the third portions 300a-300g may be of different geometries, sizes and shapes, and may extend both laterally and longitudinally in different amount so as to provide different visco-elastic dampening, again depending upon the application of the article.

Referring to FIGS. 3h-3k cross-sectional views are shown in which the third portions 310a, 310c, 310b and 310g are depicted as being encapsulated within the footwear article 300a, 300c, 300b and 300g.

Referring to FIGS. 4a-4c, there is shown another exemplary embodiment of a footwear article according to the present invention. In this embodiment, the sole 410 is provided with a concave upper surface 412 which is suitably contoured so as to provide for comfort of fit to the foot of a user when wearing the article 400. A peripheral lip 413 is provided which extends around the periphery of the sole 410 again providing for comfort to a user and for foot conformity.

In the present embodiment, the first portion 416 further extends as a medial portion 419 to provide arch support to the foot of a person. Those skilled in the art will appreciate that other geometries and positioning of the first portion 416 may be provided in other or alternate embodiments so as to provide cushioning to the underside of the foot of a person, without departing from the scope of the invention.

Referring to FIGS. 5a-5d, there are shown schematic representations of embodiments of the present invention. Referring to FIG. 5a there is shown an embodiment 500a of the invention whereby a fourth portion 515a is provided towards the metacarpal portion of a user's foot to provide for cushioning to the front portion of the foot of a user. The fourth portion may be formed from same of different materials as that of the first portion 516a.

In another embodiment of the footwear article 500b as shown in FIG. 5b, the first portion 516b and the second portion 515b are integrally formed, and co-operatively provide for lateral support of the underside of the foot of a user.

Referring to FIG. 5c, and embodiment of the footwear article 200c is shown whereby a portion 519c of the first portion provides for medial arch support.

In a further embodiment of a footwear article 500d according to the present invention as depicted in FIG. 5d, the first portion 516d is provided as two separate parts being spaced apart laterally so as to provide for increased medial or lateral support and cushioning to the underside of the heel portion of the foot of a user.

Referring to FIGS. 6a, 6b and 6c, there are shown embodiments of footwear articles 600a, 600b and 600c having various foot engagement means. FIG. 6a shows a foot engagement means 620 typical of that of a “flip-flop”, FIG. 6b shows an “cross-over” type engagement means and FIG. 6c shows a single-strap type foot engagement means 620c. Those skilled in the art will appreciate that numerous types of foot engagement means are applicable without departing from the scope of the invention.

Referring to FIG. 7a, there is shown another embodiment of a footwear article 700 according to the present invention. In the present embodiment, the first portion 710 extends along the entire length of the article 700 so as to provide the entire upper surface 720. In this embodiment, the first portion 710 again is formed from a gel material so as to provide dampening to the foot of a user upon impact, in combination with an expanded polymeric foam of which the second portion 720 is formed.

Further, in the present embodiment, elongate grooves 740 extend laterally across the upper surface 720 of the article 700. The grooves 740 allow for localized deformation of the first portion 710, which provides for additional dampening to the foot of a user during use. Furthermore, the laterally extending grooves 4740 also provide a “grip” effect which prevents slippage of the foot of a user against the other surface 720 during use.

Referring to FIG. 7b, there is shown a further embodiment of a footwear article 700 according to the present invention. Similarly as in the embodiment depicted in FIG. 7a, the first portion 710 extends the entire length of the footwear article 700 so as to form the entire upper surface 720. Again, the second portion is provided by an expanded polymeric material 720 of foam form which extends the entire length of the article 700.

In the present embodiment, grooves 740 are provided which, similarly as in the embodiment depicted in FIG. 7a, allow for localized deformation of the first portion 710, and due to the gel like properties, and further incorporation with the expanded polymeric properties of the second portion 730, the grooves 740 allow for additional dampening and cushioning to the foot of a user during use. Furthermore, again the grooves 740 provide a “grip” type effect which reduces slippage of the foot of a user on the upper surface 720 of the article 700 during use.

Referring now to FIG. 8, there is depicted yet a further embodiment of a footwear article 800 according to the present invention. In the present embodiment, the first portion 810, again formed from a gel material, and in this embodiment is provided towards the front portion of the footwear article 800. The first portion 810 forms a part of the upper surface 820, and the second portion 830, again formed from an expanded polymeric material, forms the remaining portion of the upper surface 820.

In the present embodiment, the first portion 810 provides for dampening and shock absorption at the front portion of the foot of a user in use, and furthermore, the first portion being located in this position provides for grip of the foot of a user and prevents slippage along the upper surface 820 in use.

Referring now to FIG. 9, there is depicted yet a further embodiment of a footwear article 900 according to the present invention. In the present embodiment, the first portion 910 is provided again in a gel material form, and the second portion 930 is provided in an expanded polymeric form. The first portion 910 extends the entire length of the footwear article 900 so as to form the entire upper surface 920 of the article 900

In reference to the embodiments of the invention as described in the description above, as will be appreciated by those skilled in the art, the footwear articles are provided such that the sole of the article comprises the entire sole of the device, and the foot engagement means merely hold the sole to the bottom of the foot of the user. Such footwear articles are termed different names in different parts of the world, including terms such as “flip flop”, “thongs” and “jandals”.

As will be understood by those skilled in the art, to provide a flip-flop type footwear article, the article must be extremely flexible so as to allow for continual flexing during walking or ambulation of a person. Such a sole is distinctly different from that of traditional footwear articles, whereby a comparatively small amount of flexion is allowable and typically at one portion of the sole, in comparison with that as required and provided by flip-flop type footwear articles.

As will also be appreciated by those skilled in the art, it is necessary to provide an article which, after many repetitions of flexion, maintains its structural integrity without the first portion and the second portion separating or delaminating.

Furthermore, those skilled in the art will appreciate that the sole of a flip-flop device as claimed and shown in the accompanying drawings in accordance with the present invention, only comprises the upper portion and the lower portion as described, the upper portion (i.e. first portion) providing for direct contact with the underside of the foot of a user most often without a sock, and the lower portion (i.e. second portion) engages directly with the grounds or surface upon which a person walks, without the use of additional outer source or the like.

Furthermore, flip-flop type footwear, as will readily be understood and appreciated by those skilled in the art, are often exposed to harsh environmental conditions such as water and long durations of sunlight due to their typical applications, and the materials from which they are formed and the manner in which the portions are joined, must be capable of withstanding such exposure.

As such, those skilled in the art will appreciate that a substantial difference exists between the sole of the footwear article in the present invention and those of conventional footwear, for which have in the prior art been described as being formed by multiple layers.

It will be appreciated, that as the sole of the present invention is comprised only of the first portion and the second portion, these portions must be securely joined or bonded together securely in a manner, as there exists no outer shoe body whereby an inner sole is still retained within a shoe even if not securely bonded to the inside of a shoe, and also in view of typical applications as discussed above.

The present invention has overcome problems of the prior art such as delamination, so as to provide a footwear article having a sole distinctly different from those of conventional footwear, a sole which must endure significantly larger amounts of flexion and strain, whilst maintaining the structural integrity of the sole. By provision of a “co-molding process” whereby a gel material is co-moulded with a polymeric material which is expanded in a manner so as to provide continuity between the gel-type material and the expanded polymeric material. As such, a unitary sole of a unitary construct has been provided that overcomes practical and longevity problems which may be encountered when utilizing bonding techniques such as used in the prior art. The co-molding process provides for structural integrity and also maintains the bond between the materials throughout angles of flexion of the sole well beyond the amount of flexion that conventional footwear are exposed to.

Furthermore, the co-molding process simplifies production so as to allow ease of manufacture and reduction in manual labour, and does not require separate formation of the two portions, and does not require a post-fabrication process for joining the portions.

Thus, the two portions, by being moulded, provides a unitary structure whereby the sole is formed of a “continuous” polymeric material, without the necessity for adhesive and the like, and thus mitigating the incidence of de-bonding, even throughout repetitive large amounts of flexing. The co-molding process provides for rapid and cost and time effective manufacture, and reduces the amount of material wastage, thus also providing environmental advantages.

While the present invention has been explained by reference to the examples or preferred embodiments described above, it will be appreciated that those are examples to assist understanding of the present invention and are not meant to be restrictive. Variations or modifications which are obvious or trivial to persons skilled in the art, as well as improvements made thereon, should be considered as equivalents of this invention.

Furthermore, while the present invention has been explained by reference to “flip-flop” type footwear articles, it should be appreciated that the invention can apply, whether with or without modification, to other footwear articles without loss of generality.

Claims

1-70. (canceled)

71. A footwear article comprising:

a generally elongate sole comprising a first portion, a second portion and a third portion and having an upper surface and a lower surface,
said first portion being for direct contact and interaction with at least a portion of the underside of the foot of the person and being formed from a first polymeric material having a first density;
said second portion forming substantially the entire lower surface of the footwear article and being for direct contact and interaction with a ground surface and being formed from a second polymeric material having a second density;
said third portion being disposed between the upper surface and the lower surface, and being formed from a third polymeric material,
a generally elongate and flexible foot engagement means for securing the footwear article to the foot of a person, said foot engagement being engaged directly with at least said second portion and configured so as to extend over a portion of the upper side of the foot of the person;
wherein the first material is provided in a gel form and the second polymeric material is provided in an expanded form, and wherein the first density is greater than the second density;
wherein the first polymeric material and the second polymeric material are selected and the first portion and the second portion are sized and arranged such that the sole is substantially flexible and elastic so as to allow for substantial flexion of the sole longitudinally and return, when in use and during ambulation of the person;
wherein the first polymeric material and the second polymeric material are selected and the first portion and the second portion are sized and arranged such that dampening is provided upon load being imparted to the foot of the person upon contact with the surface; and
wherein the third material property is a visco-elastic property for providing controlled deformation upon contact of the footwear article with a ground surface and return to an initial state upon removal of said impact.

72. A footwear article according to claim 71, wherein the first portion forms substantially the entire upper surface of the sole.

73. A footwear article according to claim 71, wherein the third portion is provided as a shape memory expanded polymer and the viscosity of and density is selected such that the third portion in conjunction with the third material property provides said visco-elastic property.

74. A footwear article according to claim 71, wherein the third portion is provided in the form of interconnected deformable sub-portions or discrete deformable sub-portions.

75. A footwear article according to claim 71, wherein the third portion is provided as an expanded shape memory sponge construct.

76. A footwear article according to claim 74, wherein the sub-portions a geometry which is partially spherical.

77. A footwear article according to claim 71, wherein the third portion extends substantially the length of the sole and substantially the width of the sole.

78. A footwear article according to claim 71, wherein the visco-elastic property of the third portion is non-uniform laterally.

79. A footwear article according to claim 71, wherein the visco-elastic property of the third portion is non-uniform longitudinally.

80. A footwear article according to claim 71, wherein the first polymeric material and the second polymeric material are selected from the group including thermoplastic polymeric materials, co-polymers and mixed polymer blends.

81. A footwear article according to claim 71, wherein first polymeric material and the second polymeric material are selected from the group including polyurethane, ethylene vinyl acetate, poly vinyl acetate and the like.

82. A footwear article according to claim 71, wherein the third polymeric material is polyurethane.

83. A footwear article according to claim 71, wherein said foot engagement means is selected from the group including straps, an enclosure, a buckle or the like.

84. A footwear article according to claim 71, wherein the sole is formed as a unitary construct by co-molding the first portion and the second portion together, with the third portion encapsulated within the sole.

85. A footwear article according to claim 71, wherein said foot engagement means is a “thong” type engagement means, and the footwear article is provided in the form of a “flip-flop” type footwear article.

Patent History
Publication number: 20150230547
Type: Application
Filed: Sep 10, 2012
Publication Date: Aug 20, 2015
Inventor: David Fu (Kowloon)
Application Number: 14/422,949
Classifications
International Classification: A43B 13/18 (20060101); A43B 3/12 (20060101); A43B 1/14 (20060101); A43B 13/12 (20060101);