US20240197037A1

US20240197037A1 - Shoe and inserts or layers for a shoe

Info

Publication number: US20240197037A1
Application number: US18/555,779
Authority: US
Inventors: Nikhil Gupta; Stephanie POLLACK; Düng LUONG
Original assignee: Graciella Scott LLC
Current assignee: Graciella Scott LLC
Priority date: 2021-04-20
Filing date: 2022-04-20
Publication date: 2024-06-20
Also published as: WO2022226041A3; EP4326115A2; CN117202818A; JP2024515116A; EP4326115A4; WO2022226041A2

Abstract

A shoe insole may include a compressible soft material: a first fiberboard layer below the compressible soft material: a composite rigid stiffener layer below the first fiberboard layer, the composite stiffener layer extending over no more than 60% of the area of the insole: a rigid and flexible composite shank layer below the composite stiffener layer; and a reinforcement layer. A shoe such as a high-heeled shoe may include such an insole.

Description

FIELD OF THE INVENTION

The present invention relates generally to a shoe, and an improved inner layer and/or insert for a shoe.

BACKGROUND OF THE INVENTION

High heel shoes are notoriously uncomfortable. There have been minimal upgrades and innovation to the structural integrity of a high heel shoe in the last 100 years. High heel shoes do not take into account the shape of a human foot much less the biomechanics.
Footwear with a heel height of 2 cm or higher or the like generally has a shoe shape including several layers and regions: an upper and a sole assembly connected to the upper. The sole assembly may include several layers and regions. An “insert” for a shoe may include compressible material and may be placed into a completed shoe. The midsole of the shoe may be built directly into the structure of the shoe. Both the insert and the midsole may make up the entire insole of the shoe. The mold of the shoe itself (which may be called a last) takes into account all of the insole layers, and their dimensions and measurements in order to account for accurate volume, so that there will be enough room for the volume of the foot to exist inside the shoe along with the additional volume from the addition of all layers of the insole.

SUMMARY

A shoe insole may include a compressible soft material; a first fiberboard material layer below the compressible soft material; a rigid composite shank stiffener layer below the first fiberboard layer, the composite shank stiffener layer extending over no more than 60% of the area of the insole; a rigid and flexible composite layer (e.g. extending from heel to toe) below the composite stiffener layer which may be a reinforcement layer). A shoe such as a high-heeled shoe may include such an insole. Embodiments of the present invention include a new structure, process, and manufacturing upgrade to make insoles or shoes with improved wearability and comfort.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting examples of embodiments of the disclosure are described below with reference to figures listed below. The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanied drawings.

FIG. 1 depicts an exploded view of a shoe according to embodiments of the present invention.

FIG. 2 depicts an insole or insert according to embodiments of the present invention.

FIG. 3 depicts a portion of a midsole bending under propulsion and in line with natural foot gait patterns according to embodiments of the present invention.

FIG. 4 depicts a portion of a midsole including a composite shank and stiffener according to embodiments of the present invention.

FIG. 5 shows a flowchart of a method according to embodiments of the present invention.

It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity, or several physical components may be included in one functional block or element. Reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and modules have not been described in detail so as not to obscure the invention. For the sake of clarity, discussion of same or similar features or elements may not be repeated.
Embodiments of the present invention may include an insole with varying stiffness across its length or surface, for example due to a shank stiffener extending over no more than 60% of the area of the insole or midsole, included above, below or next to a composite layer which may extend the entire length or most of the length of the insole. An insole or insert located below the upper may include a first flexible, shock-absorbing, foot conforming and deforming, natural and or synthetic polymer, closed or open celled, woven or non-woven, composite or hybrid material layer e.g. gel, silicone, foam, sponge, leather, felt, viscoelastic, emollient, EPDM rubber, latex, wool, polyurethane (PU), Elastomer, EVA (Ethylene vinyl acetate), thermoplastics, TPU, thermoset, copolymers, polyamides, or other cellular deformable and or viscoelastic material. These soft and or compressible layers may include gel or foam. Such a layer may extend the length of the shoe from heel to toe and can be paired with or without an additional second layer underneath of woven and or non-woven natural or synthetic polymer, woven and/or non woven composite and or hybrid materials (e.g. same list of materials listed above) under this first layer.
Unlike prior art high heel shoes, shoes according to embodiments of the present invention may take force pressures of the body and natural gait into account. An insole according to some embodiments may have a strategic design with additional raised/bulging shock-absorbing material placed for example in the heel, arch, right below the arch towards middle of the shoe, and with or without the additional material under the phalanges to help provide additional comfort and alleviate some of the pressure natural gravity places onto the static and dynamic foot.
A midsole (e.g. including example layer 30 in FIG. 1 ) according to some embodiments may be made of a first rigid and flexible material that bends in line with the natural gait of the foot, and which is made of materials such as woven and nonwoven materials used collectively, or individually made of woven and non-woven natural or synthetic composite and or hybrid materials e.g. engineered fibers such as carbon, glass, Kevlar, rubber grades, and natural and or synthetic fiber composite with or without laminate, thermoplastic, polylactic acid (PLA), natural fiber, plastic, thermoset, thermoset, thermoplastic, elastomer or plastic polymer resin, used in combination or individually, with a shape that extends from the heel to the toe. This first material may help reduce over pronation, and may resist torque. The midsole may be located below the sock liner/insole including several layers. A midsole may extend from heel to toe, e.g. include a foot length composite layer along with a stiffener.
A midsole stiffener or shank stiffener may be attached or adhered adjacent to the midsole and made of a second rigid material may support the stiffness of the midsole which is less flexible than the composite laminate shank and toe reinforcement layer (composite laminate shank and toc reinforcement layer may be e.g. layer 30 in FIG. 1 ), and which may extend from the heel to the bottom of the arch; this may extend for the full length of shoe, or substantially the full length. Midsole stiffener (e.g. layer 25 in FIG. 1 ) may be e.g., fiber reinforced composite with or without laminate of thermoplastic, polylactic acid (PLA), natural and or synthetic fiber, plastic, carbon thermoset, thermoplastic, elastomer, plastic polymer resin, shankboard, cardboard, rubber grades, fiberboard, MDF, woven or nonwoven insole board, wood, wood pulp, polyester fiber, bio materials, strobel insole board, leather, EVA, nylon, paper, laminated or non laminated synthetic or natural materials, open or closed cell materials, fiber-reinforced resin laminates, leatherboard, particle pressboard, cellulose or other natural or synthetic composite materials. The midsole stiffener may keep shank (e.g. layer 30) from moving and harness shape.
The stiffener (e.g. layer 25 in FIG. 1 ) and composite shank layers (e.g. layer 30 in FIG. 1 ) may be sandwiched or enclosed in between layers of fiberboard material such as shankboard, cardboard ( e.g. layers 20 and 35 in FIG. 1 ), woven or non woven, materials, cellulose, insole board, nylon, laminated or non laminated natural or synthetic materials, fiber-reinforced resin laminates and other advanced composites, paper, wood, bio materials, polyester fiber, open or closed cell materials, nonwoven or woven insole board, polyester, wool, strobel insole board, EVA, rubber grades, copolymers, PMMA, PESU, PET, PBT, ABS, PEEK, PEI, PCT, or thermoplastic, wood pulp, paper, leatherboard, leather, particle pressboard, MDF, fabric, felt, scrim, nylon, other natural and composite materials, etc. These sandwiching layers may be wider than the internal stiffener and composite layer. The “inner” layer or layers ( e.g. layers 25 and 30 in FIG. 1 ) may be sandwiched between fiberboard materials, such as shankboard, cardboard, bamboo, cork, MDF, cellulose, or other material and may use an additional shank stiffener, which could be made with plastic, bamboo, felt, paper, fabric, scrim, wood, cellulose, leatherboard, cork, polyester, wool, particle pressboard, leatherboard, nylon, insole board, laminated or non laminated, natural or synthetic composition materials, open or closed cell materials, woven or non woven, or other fiberboard materials, composite, thermoset, etc. A stiffener layer and a shank layer may be sandwiched between the fiberboard materials such as shankboard, cardboard, MDF, or cellulose. The fiberboard materials, layers may be for example ¼″ or another dimension wider than the shank and shank stiffener layers. The perimeter of the fiberboard or shankboard layers may be for example glued, tacked, bonded, high pressure or heated, sewed, stitched, stapled, fastened, stringed, screwed, nailed, formed, molded, or nailed shut to each other, encasing the composite layers. Nails, tacks, staples which may be used in the production manufacture of the shoes may penetrate the fiberboard material, cellulose, shankboard and may or may not penetrate the composite, e.g. by being positioned at the edges of the “sandwich”. This stiffener may extend from heel to arch to provide support for the arch and may maintain the longitudinal arch, may define the shape of the shoe, may maintain alignment of forepart and heel throughout all the stresses of a shoe's life, and may keep the integrity of the shape of shoe and may be used as added reinforcement of the foot. The composite and stiffener layers may provide additional shock absorption and strength to the overall shoe while also decreasing the overall weight of the shoe, making the shoe lighter vs. prior art shoes, and take the wearer's natural gait and biomechanics into account. The midsole may be attached and encased between fiberboard materials such as, e.g. shankboard, cardboard, fiberboard, cellulose, particle pressboard, leatherboard, leather, and located below the insole. This material may offer additional support for the shoe, may absorb moisture, may be durable enough to withstand friction in wear, may be flexible, may not harden and crack in wear or with moisture or perspiration, may be uniform in thickness, may be lightweight, may be resistant to shrinkage or growth, may be able to hold tacks, adhesives, nails, screws, staples, or stitches, may be dimensionally stable and may not alter in manufacture or wear and may be used for the purpose of containing the layers of the midsole and for manufacturing purposes.
The two middle layers inside the “sandwich” may include one rigid shank stiffener and may support the stiffness (e.g. layer 25 in FIG. 1 ) that runs from the heel to arch to provide support for the arch, defines the shape of the shoe, and keeps the integrity of the shape, and is attached to a rigid and flexible material that runs from heel to toe (e.g. layer 30, e.g. a shank). These layers provide additional shock absorption and strength to the overall shoe while also decreasing the overall weight of the shoe, making the shoe lighter vs traditional shoes, and take the wearer's natural gait and biomechanics into account. Prior art shoes use metal or plastic, whereas layers in embodiments of the present invention may include woven and nonwoven materials used collectively or individually made of natural and/or synthetic composite and or hybrid materials, e.g. fiber-reinforced resin laminates, engineered fibers such as, carbon, composite laminate, thermoplastic, polylactic acid (PLA), natural fiber, plastic, thermoset, thermoplastic, elastomer or plastic polymer resin, or fiber reinforced composite laminate. These two middle layers may be sandwiched between fiberboard materials e.g. shankboard, cardboard, cellulose, leather, particle pressboard, positioned above and below the two middle layers. This material provides additional shock absorption and is used for the purpose of containing the middle layers of the midsole and for manufacturing purposes. Layer 20 may be thinner than layer 35, may be of same or different materiality, may be more flexible than layer 35, may include shape retention, may absorb moisture, may be resistant to hardening or cracking due to moisture or perspiration and may be resistant to shrinkage or growth in humidity and heat. Layer 35 (e.g. fiberboard or shankboard) may be harder and thicker than layer 20, may be able to withstand tremendous loads which occur at the waist/arch and heel of a shoe, may be durable enough to stand up to friction in wear, may be lightweight, may have the ability to hold tacks, adhesive, screws, nails, staples, stitches, may have increased nail holding strength, bending strength (dimensionally stable and will not alter during wear or during manufacturing process), may be flexible, and may have shape retention.
Embodiments of shoes described herein may allow for flexibility in the sagittal plane while providing for rigidity in the frontal and transverse planes to ensure stability throughout the gait cycle. This rigidity may be a need unique to high heel shoes. This increased stability in the gait cycle may allow for more fluid and pain-free ambulation. These properties may be achieved by a combination of material selection and engineering the material structure in the composite material, including but not limited to the amount, orientation, length, and direction of fibers in each layer and collectively in the multiple layers in the laminate.
Embodiments of the invention may include, compressible materials for example, custom foot conforming composite or hybrid material like gel and/or foam (can be used collectively or individually in one or several layers, e.g. layers 10 and 15 in FIG. 1 ) deformable insole with biomechanical support shape inspired by orthotics to help stabilize and support the foot, reducing stress on feet, ankles, and knees, improve stability, lower back, provides shock absorption of gravitational forces lessening the impact on the heels and forefoot with each step, provides comfort and support, very good ability to resist change, good pressure distribution, high elasticity helps it retain its shape after each step, able to retain its shape over time, thermoregulated cooling character giving optimal temperature/keeps the foot cool and minimizes heat generated in the foot which causes friction and friction causes pain, provides ergonomic support, and enhanced breathability. This insole-or insert may include for example some or all the following in the design: full-length footbed and whole foot insole with or without met pad which may takes the weight off the ball of the foot resulting in less pressure on the metatarsals, prevents the foot from shifting forward in the shoe; a flexible arch support may be built into the shoe which forms the shape of the foot to allow maximum comfort and for the foot to remain secure in the shoe while walking, also prevents pronation; a cobra cut design in the heel may provide additional cushioning at heel taking pressure off the plantar fascia and holds the foot in to prevent it from moving around in the shoe too much; and a footbed and or toe bar may relieve pressure off the phalanges/toes preventing hammertoe formations.
In some embodiments of the invention, the toe box in a shoe may be deeper (e.g., widened) to case and relieve pressure off phalanges (e.g. toes), and reduce aggravation and progression of bunion deformities. The outsole (e.g. layer 40 in FIG. 1 ) in some embodiments may be composite, synthetic or natural, or hybrid material (e.g. fiber-reinforced resin laminates, leather, polyurethane ((PU), ethylene vinyl acetate (EVA), plastic, ASA, PMMA, PEEK, TPU, EDPM Rubber, biomaterials, thermoplastic, copolymer, bioplastics, cork, latex, thermoplastic rubber (TRP), polyvinyl chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), natural or synthetic rubber, bespoke polyurethane (BPU)), or other material, to reduce wear on the midsole, may provide grip and keep the wearer from slipping, may provide reinforcement of the shoe as it makes direct contact with the ground and may increase durability of the shoe, may be flexible, may be waterproof, and may provide additional shock absorption. A heel tip or protector may be used to protect the shoe and the wearer as it strikes the ground. The heel protector may be a flat or corrugated material and shaped to conform to the exact size and shape of the heel tip bottom surface. The heel may attach to the bottom of the outersole. The heel tip may be made with a composite or hybrid or natural material (e.g. rubber, TPU, plastic, TPU, nylon, etc.). A heel in some embodiments may be for example 2.5 cm or higher, may be positioned underneath the heel of the foot and touch the ground. A metal rod may ensure security, and may be placed centrally under the heel bone and in line with the wearer's ankle joint. A heel counter may be used to keep heel counter stiff with or without extra padding to help support the foot, minimalize Haglund's deformity aka “pump bump”, and keep it inside the shoe.
In some embodiments a shoe is lighter and more shock-absorbing than prior art high heel shoes.
FIG. 1 depicts an exploded view of a shoe including an insert or insole; and a midsole, according to some embodiments of the invention. While FIG. 1 depicts a high-heeled shoe, other types of shoes may be used with embodiments of the invention. Other layers or arrangements of layers may be used. Referring to FIG. 1 , a shoe insert may include an insole (e.g. layers 5-20) and midsole (e.g. layers 25-35). A shoe may include upper 1 which may cover the foot or contain or hold the foot inside the shoe, as is known in the art. Upper 1 may have a slightly wider toe box and increased total volume than in other comparable shoes to better fit the majority of human feet. Sock liner 5 may be placed above the midsole and insole and may make direct contact with a foot inserted in the shoe, and may be made with or without antimicrobial, sweat absorbing, and/or anti-odor properties. Sock liner 5 may be a thin piece of material which is on the top of insole or midsole 3. Sock liner 5 may protect the wearer's foot from all the inner workings of the shoe and the inner seams, may attach directly to the insole, and may be of for example a gel or foam material used with or without an additional soft hybrid or composite material, like foam or gel.
A layer 10 may include a soft deformable material, or a compressible soft material, including foot conforming deformable material e.g. gel, foam, silicone, or an open or closed or open cell spongy top. Layer 10 may provide more shock absorption of gravitational forces, reduce muscle fatigue, mold to the wearer's foot, provide pressure distribution and relief, reduce muscle fatigue to allow the wearer to be able to stand, walk, or dance longer and more comfortably, provide a full-length footbed from heel to metatarsals, maintain stability and dimensions regardless of temperature/pressure/humidity conditions, provide thermoregulated cooling character giving optimal temperature, provide enhanced breathability, provide ergonomic support, may return to original shape once pressure is removed, and may be energy absorbent. Various layers may be omitted, e.g. layer 10 may be used with or without layer 15, and additional layers, materials or structures may be included. Layers 5 and 10 may be attached (e.g. adhered, cemented, fused, thermo bonded, bonded, formed, high pressured, heated, fastened, molded, or glued) together. Layers 10 and 15 may be attached (e.g. adhered, fused, molded, bonded, thermo bonded, cemented, fastened, formed, high pressured, heated, glued, or glued together).
A foot conforming deformable compressible layer (e.g. gel or foam) insole insert 15 may be positioned below (relative to the foot, which is above, and the bottom of the shoe, which is below) layer 10. Layers 10 and 15 may be compressible, and may be made of the same or different materials as each other; in one embodiment layer 10 is gel and layer 15 is foam. In one embodiment different materials may be used in layers 10 and 15 in order to increase softness; gel may be used in one layer, and a softer foam in another layer as gel may in some cases be too hard. In other embodiments, different foams and or gels behaving in different ways may be used in each of the two layers for a more well balanced shoe. Layers 10 and 15 may be considered part of the sock liner or insert and may be considered part of the insole. Layers 10 and 15 may be combined into one layer in some embodiments.
A fiberboard material (e.g. cellulose or cardboard) layer 20 positioned below layers 5 and 10 may provide additional cushioning, may aid manufacturing/production, may provide protection for the composite materials or layers (e.g. layers 25 and 30) as well as additional reinforcement of the midsole. The shank layer (e.g. layer 30) may be positioned between the fiberboard material layer 20 and the stiffener layer (e.g. layer 25). Layers 20 and 35 may be used instead of or in additional to, fiberboard, shankboard, natural or synthetic composition, woven or non woven, laminated or non-laminated, scrim, fabric, felt, cork, leather, paper, insole board, cardboard, cellulose, leatherboard/leather, particle pressboard, MDF, or natural or synthetic woven or non woven open celled or closed celled materials. Layers 20 and 35 and 40 may allow for easy manufacture, and may sandwich around layers 25 and 30, all of layers 20, 25, 30 and 35 forming a “sandwich”; layer 40 may form an outer layer of this sandwich. Layers 35 protects the midsole from friction and wear. Layers 35 and 40 may allow for better handling and to be easily repaired by cobblers for the wearer, e.g. if the outersoles need to be replaced due to wear.
A shank stiffener, or stiffener layer 25, may be composite, high strength composite, or hybrid material (e.g. composite laminate, or hybrid, or thermoplastic, or thermoset, or plastic). Stiffener layer 25 may in some embodiments be a fiberboard layer, MDF, or cardboard or leatherboard, leather or particle pressboard, or shankboard typically thicker than would be a thermoplastic version of layer 25. Shank stiffener 25 may be positioned below fiberboard material layer 20, and may keep the shoe from collapsing, provide maximum support to the wearer while in the shoe, and may be lightweight (when in comparison to metal pieces), and in some embodiments does not stretch. Shank stiffener 25 may in some embodiments extend over no more than 60% of the area of insole or midsole 3, or over no more than 60% of the area of the shank layer (e.g. layer 30). Shank stiffener 25 may in other embodiments extend over no more than other areas, e.g. substantially 60%, substantially 55%, substantially 65%, or other portions of the area of insole or midsole 3 or the shank layer. Further, other layers, such as a composite layer or gel layer, may not extend completely the length of the shoe from heel to tip of shoe; for example one or more of these layers can extend from the heel to toe area. Typically, the fiberboard layers 20 and 35 are wider and longer, and extend of a larger area, than layers 35 and 30.
Stiffener layer 25 may be directly attached (e.g. adhered, fused, thermo bonded, bonded, formed, molded, fastened, high pressured, heated, or glued) onto composite or shank layer 30 as if it were one piece, or layers 25 and 30 may be attached as one piece as one piece, and layer 25 may be positioned above or below composite layer 30 (e.g. above when in the shoe, e.g. layer 25 may be closer to the foot than layer 30). In the case that stiffener 25 is fiberboard material, or cellulose, it may not be attached to layer 30. Stiffener layer 25 may ensure layer 30 the composite is less flexible and stiffer from heel to arch (compared to the portions of layer 30 not coextensive with or bonded to stiffener 25) and cannot move. Prior art high heel shoes do not incorporate molding a midsole as one piece, and thus may use metal as a shank, and attach the metal shank onto a last, a mold of shoe, and hammer or machine press it to the proper shape.
Instead of a metal shank or a metal global repair shank as in prior art shoes, embodiments may use an additional piece of shankboard, fiberboard, cellulose, thermoset, copolymer, polyamides, plastic, or thermoplastic in layer 25 that may be attached (e.g. glued, fastened, formed, molded, or bonded) onto the composite shank 30 as a shank stiffener, e.g. for the arch to heel area.
Shank and toe reinforcement 30 may be a rigid and flexible shank layer positioned below shank stiffener 25 and may be formed from bendable composite laminate (e.g. carbon fiber) may provide underfoot support, protect the shoe wearer from feeling hard objects on the ground, increase stability, provide additional shock absorption, increase foot flexibility reducing fatigue, prevents foot from turning in the wrong direction, and increase protection of the foot. Composite layer 30 may be rigid and flexible in that a portion of it may bend up, not down, e.g. as shown in example FIG. 3 . Shank layer 30 may be a reinforcement layer, a part that gives the shoe it's shape, and also what keeps it sturdy. Shank and toe reinforcement 30 may extend from the heel area of the insole to the toe area of the insole. Shank and under foot reinforcement may protect the wearer from feeling hard objects on the ground, may increase stability, may provide additional shock absorption, may increase foot flexibility reducing fatigue, may increase protection of the foot, may be lightweight (comparison to prior art metal layers), may enable more energy into the step, may follow natural gait patterns to optimize and enhance natural foot movements and conserve energy, may reduce the size and bulk of midsole creating a lighter shoe that further reduces fatigue, and may not stretch.
Shank and toe reinforcement 30 layer and shankboard layer 35 may bend in one directional motion only, upwards, dorsiflexion and plantarflexion (sagittal plane), during propulsion following the natural gait of the foot; e.g. this bending may be unidirectional and typically this layer cannot or should not move/bend the other way (downward) because the foot does not move in the transverse or frontal plane. This works to protect your feet and minimize over-bending to reduce fatigue. Frequently wearing high heels can cause one's toes to stay hyperextended position which a midsole according to one embodiment may accommodate. It may not be desirable to have movement from the heel to arch areas, and thus in some embodiments layer 30 is held in place in the area from heel area 3 to arch area 23, e.g. no more than 60% of the extent of layer 25. When people walk the force pressure and ground reaction forces are absorbed by the whole foot in a cyclical-type motion.
The feet may act as shock absorbers in three different directions: the first is pronation, the motion of the foot during the gait cycle wherein the foot rolls inward to displace shock. When one runs or jumps, the foot strikes the ground primarily against the outside edge of the foot with the ankles turned inward. As the weight of one's body is spread across the foot, the foot and ankle turn inward, and the arch flattens out. A second way that the foot absorbs shock is through transverse arch flattening. There are five metatarsal bones in the foot. The transverse arch runs across these metatarsal bones. When walking, the foot rolls inward across the ball of the foot, from the outside of the foot to the big toe.
The foot makes contact with the ground beginning with the fifth metatarsal bone. Because the fifth metatarsal is so flexible, it provides a gentle impact. The transverse arch starts to flatten out, which widens the ball of the foot. The third way that the foot absorbs shock is through the toes splaying apart. As the feet bear weight, the metatarsals widen, causing the toes to splay apart. This provides a stable base for the body. In addition, this splaying of the toes offers a greater area of contact with the ground so that the nerve endings in the feet can receive and transmit information from the ground.
Having a bendable layer that follows the gait allows for added support in the propulsion of the foot (toe area of the foot). Unidirectional layer 30 may be designed to provide flexibility as the wearer's foot touches down on the ground, a toc-off that allows for maximum propulsion and an economically ergonomically guided stride. Such a mechanism has not been used in prior art high-heel shoes. The toe area/footbed 33 may be flexible or more flexible of the area between the heel-to-arch area.
Layers 20 and 35 may be fiberboard material such as shankboard, MDF or cardboard or cellulose. Layers 20 and 35 may together envelope around the composite laminate layer 30 and stiffener layer 25 and possibly other layers. The edges or sides of layers 20 and 35 may extend beyond the layers they envelop, enclose or sandwich (e.g. beyond the width of the shank layer and beyond the width of the stiffener layer). The edges or sides of layers 20 and 35 may be shaved or skived and may join to each other and be attached (e.g. adhered, fused, thermo bonded, bonded, cemented, high pressured, heated, formed, molded, stapled, sewed, screwed, stitched, stringed, nailed, fastened, tacked or glued) to each other at their edges or periphery to seal in at least the composite layer and stiffener layer. In one embodiment, the composite and stiffener layers are connected or attached to each other, but not to encapsulating layers 20 and 35: the composite and stiffener layers may be placed inside the sandwich of the fiberboard layers, and fiberboard layers may be attached only to each other, at their periphery where they extend beyond the composite and stiffener layers. Layers 10, 15 and/or 20 may be attached (e.g. fused, molded, adhered, glued, thermo-bonded, cemented, heated, high pressured, formed, bonded, fastened, etc.). Layers 25 and 30 and may be restrained or sandwiched between layers 20 and 35, but also may be directly attached to layers 25 and 35.
An outer sole 40 may provide reinforcement to the shoe as it hits the ground, and additional shock absorption. A heel 45 is in one embodiment 2.5 cm or higher, and may be positioned underneath the wearer's heel and may touch the ground. Heel 45 may be placed centrally under the heel bone and in line with the wearer's ankle joint to enable the back of the shoe to touch the ground.
Insole or midsole 3 may include layers 5-35, and may reduce weight significantly in comparison to metal, steel or brass components, and may ensure safe, stable, and maximum support to the wearer.
Shank stiffener, or stiffener layer 25 may provide and enhance the rigidity and stiffness of a portion the midsole, e.g. in one example no more than 60% of the composite shank layer 30 may be reinforced by layer 25, for example from arch to heel, heel to metatarsal, or from the rear of the midsole to a middle portion. Stiffener layer 25 may extend across other portions of the composite layer, e.g. 50% or 60% of the layer. Stiffener 25 material may be any suitable material that can work alongside the composite material, such as thermoplastic, plastic, thermoset, rubber grades, copolymers, a fiberboard, shankboard, cardboard, or cellulose. Typically, stiffener 25 is made of second material less flexible and stiffer than shank and toe reinforcement 30. The manufacture of a shoe with a heel as opposed to a flat is different, as more attention needs to be paid to the strength (e.g. measured in MPa) of the arch of the foot: thus shanks and shank stiffeners according to the present invention may improve prior art shoes.
FIG. 2 depicts an insole according to embodiments of the present invention. In FIG. 2 , insole layer 100 (which may correspond to layer 10 in FIG. 1 ) may include circular area 105 at the bottom of FIG. 2 , e.g., the rear of the layer, which may be for example gel. Triangular area 110 with an elevated area in the middle may be for example gel. Raised curved area 115 near or on the arch may be for example gel, smaller triangular area 117, and horizontally oriented “foot” shaped area 120 at the top of the figure, near the front of the layer, may also be gel. The entirety of gel insole 100 may be encased in film. Other shapes or positions for areas 105-120 may be used, and materials for cushioning or padding other than gel may be used.
FIG. 3 depicts a portion of a composite layer bending under propulsion and in line with natural foot gait patterns according to embodiments of the present invention. In FIG. 3 , the front portion of the composite layer bends upward (e.g. towards the foot, away from the ground) as at the front portion the composite layer shank and toe reinforcement layer (e.g. layer 30 in FIG. 1 ) can bend, and in the middle to the rear portion the stiffener (e.g. layer 25 in FIG. 1 ) keeps the composite layer from bending in any direction. The part that is free of stiffener (e.g. below the arch) bends up to follow foots natural gait pattern. While the part bends up, it is not desirable for the composite layer to bend the other way. To better support the foot, the layer 30 may bend up; in some embodiments it is not desirable for the composite layer to bend the other way.
Around age 2, the human foot is still flexible and soft, but the muscles and arch begin to mature. As we age, the foot becomes more narrow and starts to look like a more developed foot. As we continue to grow, soft tissue is less adaptable and requires support and stability to support the arch and relieve pressure. The ankle joint moves the foot up and down (plantarflexes and dorsiflexes). The toes also move up and down. The middle of the foot does not move. The reason layer 30 bends upward is because the toes dorsiflex and are supported to keep them from bending down. The bend down in high heels can cause hammer toes; the toes are forced together. Layer 30 may keep that from happening in high heel shoes, unlike in prior art shoes. An important function of the foot is propulsion of weight during stance phase. This function is made possible by the midtarsal joint (midfoot) locking and unlocking. During heel strike, the foot needs to be flexible in order to adjust to the surface and the midtarsal joint unlocks to provide this flexibility. Later in the gait cycle, the foot then needs to act as a rigid lever to propel the weight of the body forward which is made possible by midtarsal joint locking. During pronation/eversion of the foot, the axis of the talonavicular and calcancal cuboid (midfoot) joints are parallel to each other, making it easier for them to independently move and unlock the midtarsal joint. The axes cross each other during supination/inversion and locks the metatarsophalangeal joint making it difficult to move.
FIG. 4 depicts a portion of a midsole according to embodiments of the present invention. In FIG. 4 , shank stiffener (e.g. layer 25 in FIG. 1 ) is depicted as area 400 extending from heel to arch, and shank and toe reinforcement layer (e.g. layer 30 in FIG. 1 ) can be seen unobscured in portion 410 from heel to toe (shank and toc reinforcement layer is obscured in the portion where stiffener layer is placed over it). The shank stiffener may be thermoset, thermoplastic, copolymer, or a different fiberboard material such as shankboard, cellulose or cardboard, MDF.
Layers that include gel, e.g. layer 10 or the layer depicted in FIG. 2 , may include a gel with a shore or durometer level of 55-65 shore, or approximately 55 shore; in other embodiments the shore range may be 25-65. A foam or gel having lower shore levels, e.g. 5-15, may be used under the conformable material, e.g. foam or gel having 55-65 shore. One way of achieving desired softness in some embodiments includes using material having 55 shore is to combine it with material in certain areas having lower shore, e.g. 5-15 shore or utilize a gel without combination in the shore range of 25-50. An embodiment may use a shore 55 compressible material, e.g. foam or gel, so that the film will not break, an additional foam with a durometer shore measurement of for example 15. Embodiments may use a gel insole with dual durometer shore ratings, with the base being 55-65 and bulges or pads ( e.g. areas 105, 110, 115 and 120) being in our desired range of 25-50, or lower, e.g. 10 shore or approximately 10 shore. shore.
From the perspective of podiatry, prior art high heel shoes in general do not work well. Prior art high heel shoes may include problems such as the following, which embodiments of the present invention may alleviate:

- They may not take pressure distribution into account (e.g. the majority of weight is placed on forefoot).
- They may not be designed to follow the shape of the foot and do not provide much arch support.
- Even low-profile orthotics may be very difficult to wear in high heels because they raise the arch causing foot to lift out of shoe. They also have a tendency to shift in shoe.
- They may not have enough padding for comfort.
- With a decentralized heel rod when the heel of the shoe sits at the back of the heel bone instead of centrally, the weight of the body will be thrust forward causing premature pain to the ball of the foot. In addition, the upper body may be more inclined to hunch forward and the knees will (nearly) always be held in a bent position exacerbating muscle fatigue particularly in the quadriceps. The ability to put weight through the heel and rest may be drastically reduced. It may affect walking style and instead of a natural heel-toe action the wearer may be forced to walk with the foot landing first.
- Prior art shoes may aggravate the symptoms and progression of bunion deformities from tight-fitting/narrow toe box which does not accommodate the normal structure of forefoot. Heels put pressure on the big toe, pushing it towards the second toe causing further exacerbations.
- Metatarsalgia—if the majority of the bodyweight (pressure) is on ball of foot, this overuses the fat pad in forefoot, causing it to thin.
- Neuroma—tight-fitting/narrow shoes can cause pressure on balls of feet and for the metatarsal heads to be squeezed together causing the nerves in the feet to become inflamed.
- Hammertoes—heel height forces the toes to bend as they lean forward. Over time the bent toe can no longer straighten on its own. This also may be due to tight, narrow toe box not having enough room in the shoe.
- Ankle sprains—such prior art shoes may not offer much support, and very slippery insoles making the wearer more prone to twisting their ankle.
- Ingrown toenails—high heels compress the toes together which can cause the big toe to grow into the skin resulting in an ingrown toenail.
- Back pain—the shoe may tilt the pelvis forward causing tightening in hip flexors and hamstrings. It can also cause an increased curvature or arch in the back b/c body weight is pushed forward (e.g. this may change one's posture).
- Haglund's deformity, aka “Pump Bump”—rigid backs of pump-style shoes can create pressure that aggravates the enlargement when walking.

In some embodiments, shoes, inserts, or high heel shoes according to the present invention may:

- Use a foot conforming deformable compressible insole which may be shock-absorbing, lessening the impact on the heels, arch, and forefoot with each step. This may provide comfort and support, provide very good ability to resist changes (e.g. buffering ability), good pressure distribution. High elasticity may be used to help it retain its shape after each step, and allow it able to retain its shape over time (e.g. be dimensionally stable).
- Include a “met pad”, e.g. the circular area 3 near the arch in FIG. 2 , which takes the weight off the ball of the foot resulting in less pressure on the metatarsals, and may prevent foot from shifting forward in the shoe.
- Include flexible arch support near area 115, which may be built into the shoe forming to the shape of the foot to allow maximum comfort and for the foot to remain secure in the shoe whole walking, and also prevent pronation.
- Include a cobra cut near circular area 105 to provide cushioning at heel, taking pressure off the plantar fascia. The cobra cut may be an area behind the heel (e.g. starts on the left), which wraps around the back of the heel and extends (on the right) straight into the arch.
- Include a toe bar and under toe(s) near areas 110 and 117, padding and additional cushioning to provide support to the flanges and metatarsals in the foot during static and dynamic movement(s)
- Include a minor heel cup (e.g. area 105) with an additional heel bump (e.g., the raised bump in the middle of the heel area 105) in the middle of the heel to help foot from shifting forward in the shoe and provide additional padding.
- Heel placement may have a centralized heel rod which is critical for comfort and protection.

Embodiments may include a custom last which may be made to better fit the modern wearer's actual foot anatomy by widening the toe box, and can vary in height, shape, instep, pitch, and structure; and may be longer, providing more access to movement in all directions. Embodiments may use an updated last to fit internal components of an embodiment of the shoe, updated to accommodate a modern wearer's (e.g. women's, men's, gender non-binary people's) actual foot size and measurement, have enough volume, size and proper shape to accommodate these factors while still keeping aesthetic integrity. Before shoes can go into production, a last is produced which should be precise, which mimics foot shape and gives the shoe both shape and aesthetic. A number of factors may be taken into account, e.g., how the foot rolls when one walks, heel height, how deep or wide the toe box is, as well as the shoe overall, to better fit a modern human foot, take internal volume and internal insole/midsole layers (e.g. those of FIG. 1 ) into account, as well the aesthetic design. Later in the design process, the last may be placed inside the shoe so it can be molded or formed around it and is used again when the shoe is almost finished to ensure end fit matches design and aesthetic.
FIG. 5 shows a flowchart of a method according to embodiments of the present invention. The operations of FIG. 5 may be used to produce components such as those shown in FIGS. 1-4 , but may be used with other shoes and inserts.
Referring to FIG. 5 , in operation 500, a first compressible gel layer (e.g. layer 10 in FIG. 1 ) may be attached (e.g. adhered, glued, molded, formed, fastened, or bonded) to a sock liner layer (e.g. layer 5, layer 10 being below layer 5 when inserted in an upright shoe) and to a second compressible layer (e.g. layer 15, layer 15 being below layer 10), if present. Prior to adhering in operation 500, the first compressible layer may be cut, formed, or shaped into a required shape relevant to second compressible layer and the second compressible layer may be cut into required shape relevant to a first fiberboard layer. The order of operations in FIG. 5 may be different: for example the attachment of the first compressible layer to the second compressible layer may happen towards the end of the process.
In operation 505, if present, a second compressible layer (e.g. layer 15) may be attached to a first compressible layer (typically positioned above the second compressible layer) and to a first fiberboard layer (e.g. layer 20, which may be below layer 15). The attachment of the first compressible layer to the second compressible layer may happen towards the end of the process.
In operation 510, fiberboard layers (e.g. layers 20 and 35) may be cut or formed to be wider than stiffener layer (e.g. layer 25) and composite layer (e.g. layer 30).
In operation 515, stiffener layer (e.g. layer 25) and composite layer (e.g. layer 30) may be cut more narrowly than the fiberboard layers; this may use a more complex process than prior art shoes.
In operation 520, stiffener and composite layers may have strategic holes or perforations placed through different areas in advance, e.g. prior to being placed in the sandwich, to keep screws, nails, staples, needles, tacks, from penetrating these materials. Enclosing fiberboard or cardboard layers may be wider than the composite layers, and or stiffener and composite layers may have holes created in them in advance, to prevent screws, staples, needles, tacks, or nails from penetrating the inner sandwich materials from being perforated by screws, staples, tacks, needles, or nails, which may cause cracks in the lamina, especially with increased wear and time. Holes, perforations or openings may be cut or formed in one or more of the stiffener layer and composite prior to positioning each fiberboard layer to surround the combination of the stiffener layer and composite layer.
In operation 525, the stiffener layer may be attached (e.g. adhered, glued, fastened, bonded, fused, heated, high pressured, molded, or formed) to the composite layer.
In operation 530, stiffener layer (e.g. layer 25) and composite layer (e.g. layer 30) may be molded, and or formed, and shaped, to the precise shape of the last, possible using a more complex process than prior art shoes, depending on heel height and design. Layers 15, 20, 35, and 40 may also be molded and or formed to precise shape of last. Layers may be molded and or formed to the last separately, not together, or as part of the same action.
In operation 535, each fiberboard layer may be positioned so that the combination of the two fiberboard layers surrounds the combination of the stiffener layer and composite layer. For example, fiberboard layers 20 and 35 may be positioned to sandwich or surround the middle stiffener and composite layers, and may be attached, (e.g. adhered, glued, nailed, stapled, sewed, stitched, tacked, screwed, fastened, bonded, molded, formed, or fused), around their periphery (typically layers 20 and 35 are attached, (e.g. nailed, fused, stapled, tacked, adhered, etc.) to each other and this connection between layers 20 and 35 does not connect to the inner layers of the stiffener and composite). Fiberboard layers may be glued to the stiffener layer. This may be performed to keep, for example, nails or machinery used during the manufacturing process, from penetrating the composite and stiffener layers.
In operation 540, an upper (e.g. upper 1) may be attached, (e.g. adhered, sewed, stitched, nailed, stapled, glued, bonded, screwed, stringed, tacked, fused, or molded, formed, fasted), around the last (which may be used to construct the insole and midsole), above or below the compressible insole, and or above or below the midsole, and or over to below layer 35. This layer may be shaved, skived, or sanded down on the edges to keep layer even.
In operation 545, outersole layer 40 may be attached, (e.g. adhered, glued, molded, formed, stitched, nailed, sewed, or bonded, formed, molded, tacked, stapled, stringed, screwed, fused, fastened) to a second fiberboard material layer (e.g. layer 35).
In operation 550, heel 45 may be attached, (e.g. screwed, glued, adhered, nailed, sewed, stitched, bonded, molded, formed, fused, fastened, stringed, welted, strobeled, stapled), or otherwise connected to the shoe, e.g. to layers 20-40, or specifically to outsole (e.g. layer 40) only.
In operation 555, sock liner layer 5 and a compressible layer may be inserted into shoe before or after upper 1 is attached. Compressible layer(s) (e.g. 10-15) may be inserted before or after upper 1 is attached. In some embodiments, all soft insole layers are inserted into the shoe after heel is attached: for example insole materials are attached at the beginning, the second compressible layer may not molded or formed along with first fiberboard material, and the insole/insert may not be attached to first fiberboard material until after or before the heel is attached. In some embodiments, the sock liner and first compressible layer are inserted before or after the heel is attached e.g. only the sock liner and first compressible are attached and are not attached to the second compressible (e.g. second compressible layer 15) layer until after the heel is attached.
Other operations or series of operations may be used. In the description and claims of the present application, each of the verbs, “comprise”, “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of components, elements or parts of the subject or subjects of the verb. Unless otherwise stated, adjectives such as “substantially” and “about” modifying a condition or relationship characteristic of a feature or features of an embodiment of the disclosure, are understood to mean that the condition or characteristic is defined to within tolerances that are acceptable for operation of an embodiment as described. In addition, the word “or” is considered to be the inclusive “or” rather than the exclusive or, and indicates at least one of, or any combination of items it conjoins.
Descriptions of embodiments of the invention in the present application are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments. Embodiments comprising different combinations of features noted in the described embodiments, will occur to a person having ordinary skill in the art. Some elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. The scope of the invention is limited only by the claims.
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A shoe insole comprising:

a compressible soft material;

a first fiberboard material layer below the compressible soft material;

a stiffener layer below the first fiberboard, the stiffener layer extending over no more than 60% of the area of the insole; and

a rigid and flexible composite shank layer below the stiffener layer.

2. The shoe insole of claim 1 comprising a second fiberboard material layer below the rigid and flexible composite shank layer, the first fiberboard material layer and second fiberboard material layer enclosing the stiffener layer and shank layer.

3. The shoe insole of claim 2, wherein the first fiberboard material layer is attached to the second fiberboard material layer at the periphery of the first fiberboard material layer.

4. The shoe insole of claim 1 wherein the rigid and flexible shank extends from the heel area of the insole to the toe area of the insole.

5. The shoe insole of claim 1 wherein the rigid and flexible shank layer and stiffener are attached as one piece.

6. The shoe insole of claim 1, wherein the first fiberboard material layer extends beyond the width of the shank layer and beyond the width of the stiffener layer.

7. The shoe insole of claim 1, wherein the toe area is flexible.

8. A shoe comprising:

a compressible material layer;

a first fiberboard material layer;

a composite shank layer below a stiffener layer; and

the stiffener layer extending over no more than 60% of the area of the composite shank layer; wherein the stiffener layer is positioned between the first fiberboard material layer and the shank layer.

9. The high-heel shoe of claim 8 comprising a second fiberboard material layer positioned below the rigid and flexible shank layer, the first fiberboard material layer and second fiberboard material layer forming a sandwich around the stiffener layer and shank layer.

10. The high-heel shoe of claim 9, wherein the first fiberboard material layer is attached to the second fiberboard material layer at the edge of the first fiberboard material layer.

11. The high-heel shoe of claim 8 wherein the rigid and flexible shank extends from the heel area of the shoe to the toe area of the shoe.

12. The high-heel shoe of claim 8 wherein the rigid and flexible shank layer and stiffener are attached, as one piece.

13. The high-heel shoe of claim 8, wherein the first fiberboard material layer extends beyond the width of the shank layer and beyond the width of the stiffener layer.

14. The high-heel shoe of claim 8, wherein the toe area is flexible.

15. A method comprising:

cutting two fiberboard layers to each be wider than each of a stiffener layer and a composite layer;

attaching the stiffener layer to the composite layer; and

positioning each fiberboard layer to surround the combination of the stiffener layer and composite layer.

16. The method of claim 15, comprising attaching the two fiberboard layers to each other.

17. The method of claim 15, comprising attaching the two fiberboard layers to each other at their periphery.

18. The method of claim 15, comprising attaching the two fiberboard layers to each other such that the fiberboard layers to not attach to the stiffener layer and composite layer.

19. The method of claim 15, wherein the stiffener layer extends over no more than 60% of the area of the composite layer.

20. The method of claim 15 wherein the stiffener layer and the composite are-attached as one piece.

21. The method of claim 15, comprising forming or cutting holes in one or more of the stiffener layer and composite prior to positioning each fiberboard layer to surround the combination of the stiffener layer and composite layer.