INSOLES, SHOES AND PRODUCTION METHODS
The present invention relates to an improvement to footwear. An insole is disclosed which is especially advantageous for users of high-heeled shoes. The insole comprises a cushioning pad arranged in a heel region and/or a toe region of the insole. The cushioning pad comprises an inner pad material and an outer pad material, the outer pad material enclosing the inner pad material to form a hermetically sealed pocket containing at least air and the inner pad material. A viscoelastic foam layer which extends continuously from one end of the insole to the other end of the insole in a longitudinal direction is arranged on the two cushioning pads. A shock-absorbing layer is arranged between the cushioning pad and the viscoelastic foam layer. A top layer which also extends continuously from one end of the insole to the other end of the insole in a longitudinal direction is arranged on the viscoelastic foam layer and comprises perforations provided in the heel region and the toe region.
This application is a 371 national phase U.S. non-provisional patent application, which claims the benefit of priority from Patent Cooperation Treaty International Patent Application Number PCT/GB2015/050371 filed on Feb. 11, 2015, and GB Patent Application No. 1402326.1 filed on Feb. 11, 2014, the entire disclosures of which are incorporated herein.
FIELDThe present invention relates to insoles for footwear.
BACKGROUNDFoot pain and sore feet are problems commonly associated with uncomfortable footwear. High-heeled footwear in particular have a reputation for causing a significant amount of discomfort. Many users of such footwear experience foot pain related to the footwear immediately or after a few hours of wearing such footwear. The pain is due to the wearer's foot being on an inclined plane and being pulled forward by gravity toward the toes. The pressure on the metatarsal foot region (ball or forefoot) and the squeezing effect on the toes give rise to a painful sensation in these areas of the foot, as well as a feeling of fatigue and discomfort in the foot and other areas of the body. Furthermore, most humans walk leading with their heel first. This places pressure on the heel region and can similarly give rise to pain and discomfort.
Various types of insole have been developed to alleviate such problems. Some of these include flexible inserts or insoles, which attempt to provide cushioning or support to parts of the foot.
For example, U.S. Pat. No. 7,322,132 discloses an insole for a high-heeled shoe comprising raised areas in particular regions of the insole in order to support particular areas of the foot. However, the insole disclosed therein does not provide cushioning for the foot, which is an important factor for comfort.
The use of cushioning layers of varying degrees of comfort is known. For example, U.S. Pat. No. 4,633,598 discloses an insole for athletic shoes comprising layers of varying hardness and a shock-absorbing foam in the heel region. However, the disclosure only concerns athletic shoes. It does not address the problem of how to provide comfort in a high-heeled shoe and does not provide cushioning in areas which affect high-heeled shoe wearers.
Furthermore, the use of insole layers to provide comfort is constrained by the thickness of the insole. If the insole is too thick, this may cause problems in inserting the foot into the item of footwear. Thus, no one has yet found the optimum way to provide maximum cushioning, shock absorption and support for an insole, particularly in stiletto shoes, where the heel is significantly higher than the toes.
SUMMARYThe present invention attempts to address these problems by providing an insole for footwear.
The insole preferably comprises a first material extending continuously from one end of the insole to the other end of the insole in a longitudinal direction and optionally a cushioning pad arranged in a heel region and/or a toe region of the insole. The cushioning pad preferably comprises an inner pad material and an outer pad material, the outer pad material optionally enclosing the inner pad material to form a hermetically sealed pocket preferably containing at least air and the inner pad material.
The cushioning pad is typically arranged below the first material.
The inner pad material is preferably a mesh spacer fabric.
The mesh spacer fabric typically has a structure comprising a fibrous core sandwiched between two mesh layers. The inner pad material preferably comprises two of these structures stacked on top of each other.
The mesh spacer fabric is optionally made from synthetic fibre.
The inner pad material is preferably a viscoelastic foam, more preferably an open-celled viscoelastic foam, and optionally a polyurethane foam.
The outer pad material is preferably impermeable to water, and optionally made from at least one of: polypropylene, polyethylene, nylon, polyvinyl chloride and polytetrafluoroethylene.
The first material is preferably a viscoelastic foam, more preferably an open-celled viscoelastic foam, and optionally a polyurethane foam. Optionally, the first material has one or more of the following properties:
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- a) a density of between 120 and 450 kg/m3 measured with ASTM D3574-95 Test A;
- b) a compression set of between 0 and 15% measured with ASTM D3574 Test D at 70 degrees Celsius;
- c) a compression force deflection of between 0 and 350 kPa measured at 5 mm/min, strain rate force measured at 25% deflection; and
- d) a ball rebound resilience value of between 0 and 30% measured with ASTM D2632-96, vertical rebound.
The insole optionally further comprises an upper layer arranged above the first material and typically extends continuously from one end of the insole to the other end of the insole in a longitudinal direction.
The upper layer preferably comprises perforations, optionally wherein the perforations are arranged only in a heel region and/or in a toe region of the upper layer.
Preferably, the upper layer is porous and is optionally a synthetic fibre, leather, pigskin or sheepskin.
The insole optionally further comprises an intermediate layer arranged between the cushioning pad and the first material. The intermediate layer is preferably a viscoelastic foam, more preferably an open-celled viscoelastic foam, and optionally a polyurethane foam. Optionally, the intermediate layer has one or more of the following properties:
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- a) a density of between 80 and 100 kg/m3 measured with ASTM D3574-95 Test A;
- b) a compression set of between 0 and 1% measured with ASTM D3574, compressed by 25% for 22 hours at 70 degrees Celsius;
- c) an indentation force deflection of between 10 and 50 lb/(50 in2) measured with ASTM D3574 Test B1; and
- d) a ball rebound resilience value of between 0 and 3.5% measured with ASTM D3574.
- Optionally, the intermediate layer is an ethylene-vinyl acetate foam.
The insole is conveniently configured to be removably placed in footwear comprising a heel. Preferably, the removable insole further comprises an anti-slip material to prevent slippage between the removable insole and the inside of the footwear.
The insole is optionally formed integrally within an item of footwear.
The present invention also provides an item of footwear comprising an insole in accordance with the invention. Typically, the item of footwear further comprises a heel, wherein said heel is preferably higher than 4 cm.
The present invention also provides a high-heeled shoe (preferably a stiletto shoe) comprising an insole, said insole preferably comprising a first material extending continuously from one end of the insole to the other end of the insole in a longitudinal direction and optionally a cushioning pad arranged in a heel region and/or a toe region of the insole. The cushioning pad preferably comprises an inner pad material and an outer pad material, the outer pad material optionally enclosing the inner pad material to form a hermetically sealed pocket preferably containing at least air and the inner pad material.
The present invention also provides a method of making an insole for footwear preferably comprising enclosing an inner pad material and air with an outer pad material, optionally hermetically sealing the outer pad material to form a cushioning pad having an inner pocket preferably containing at least the inner pad material and air, and optionally adhering a continuous piece of material to the cushioning pad such that the cushioning pad is arranged in a heel region and/or a toe region of the insole.
The present invention also provides a method of making a high-heeled shoe (preferably a stiletto shoe) typically comprising providing a high-heeled shoe, optionally enclosing an inner pad material and air with an outer pad material, optionally hermetically sealing the outer pad material to form a cushioning pad having an inner pocket preferably containing at least the inner pad material and air, optionally providing the cushioning pad on the inside base of the high-heeled shoe in a heel region and/or a toe region, and optionally adhering a continuous material extending from one end of the high-heeled shoe to the other end of the high-heeled shoe in a longitudinal direction on to the cushioning pad.
An insole according to another embodiment of the invention preferably comprises a first material extending continuously from one end of the insole to the other end of the insole in a longitudinal direction, and optionally a first viscoelastic foam arranged only in a heel region and in a toe region of the insole. The insole preferably further comprises a resilient material typically arranged only in a heel region and in a toe region of the insole.
The present invention also provides an insole for footwear, preferably comprising a first viscoelastic foam and a resilient material each conveniently arranged only in a heel region and in a toe region of the insole.
The resilient material of the insole is preferably polyurethane foam, ethylene vinyl acetate foam, silicone or rubber. The insole optionally further comprises a first material extending continuously from one end of the insole to the other end of the insole in a longitudinal direction. The first material conveniently comprises perforations, optionally wherein the perforations are arranged only in a heel region and/or in a toe region of the first material. Preferably the first material is porous, and is optionally a synthetic fibre, leather, pigskin or sheepskin.
The first material is optionally a viscoelastic foam, preferably an open-celled foam.
The insole typically further comprises an intermediate viscoelastic foam arranged between the first material and the first viscoelastic foam and is preferably arranged continuously from one end of the insole to the other end of the insole in a longitudinal direction.
The intermediate viscoelastic foam is preferably an open-celled foam.
The first viscoelastic foam is preferably an open-celled foam and optionally polyurethane. Optionally, the first viscoelastic foam has one or more of the following: (a) a density of between 80 and 100 kg/m3 measured with ASTM D3574-95 Test A; (b) a compression set of between 0 and 1% measured with ASTM D3574, compressed by 25% for 22 hours at 70 degrees Celsius; (c) an indentation force deflection of between 10 and 50 lb/(50 in2) measured with ASTM D3574 Test B1; and (d) a ball rebound resilience value of between 0 and 3.5% measured with ASTM D3574;
The intermediate viscoelastic foam is optionally polyurethane, or the first material is optionally polyurethane. Optionally, the intermediate viscoelastic foam or the first material has one or more of the following: (a) a density of between 120 and 450 kg/m3 measured with ASTM D3574-95 Test A; (b) a compression set of between 0 and 15% measured with ASTM D3574 Test D at 70 degrees Celsius; (c) a compression force deflection of between 0 and 350 kPa measured at 5 mm/min, strain rate force measured at 25% deflection; and (d) a ball rebound resilience value of between 0 and 30% measured with ASTM D2632-96, vertical rebound;
The insole optionally further comprises a cork material preferably arranged only in the heel region and in the toe region of the insole. The cork material is typically arranged between the first viscoelastic foam and the resilient material.
The resilient material optionally contains odour-controlling or anti-microbial ingredients.
The insole is conveniently configured to be removably placed in footwear comprising a heel. Preferably, the removable insole further comprises an anti-slip material to prevent slippage between the removable insole and the inside of the footwear.
The insole is optionally formed integrally within an item of footwear.
The present invention also provides an item of footwear comprising an insole in accordance with the invention. Typically, the item of footwear further comprises a heel, wherein said heel is preferably higher than 4 cm.
The present invention also provides a high-heeled shoe (preferably a stiletto shoe) comprising an insole, said insole preferably comprising a first viscoelastic foam preferably arranged only in a heel region and in a toe region of the insole and typically further comprising a continuous material over said first viscoelastic foam. Optionally, the high-heeled shoe further comprises a resilient material under said first viscoelastic foam, said resilient material typically being only in a heel region and in a toe region of the insole.
The present invention also provides a method of making an insole for footwear preferably comprising providing a first viscoelastic foam in two regions and typically adhering a continuous piece of material to the first viscoelastic foam such that the first viscoelastic foam is conveniently arranged only in a heel region and a toe region of the insole.
The present invention also provides a method of making an insole for footwear preferably comprising providing a first viscoelastic foam in two regions, optionally providing a resilient material in two regions and optionally adhering the first viscoelastic foam to the resilient material such that both the first viscoelastic foam and the resilient material are conveniently arranged only in both a heel region and a toe region of the insole.
The present invention also provides a method of making a high-heeled shoe (preferably a stiletto shoe) typically comprising providing a high-heeled shoe, preferably providing a first viscoelastic foam to the inside base of the high-heeled shoe in a heel region and toe region and conveniently adhering a continuous material extending from one end of the high-heeled shoe to the other end of the high-heeled shoe in a longitudinal direction on to said first viscoelastic foam. Optionally, the method further comprises adhering a resilient material under the first viscoelastic foam preferably only in a heel region and a toe region of the high-heeled shoe.
The present invention will now be described, by way of non-limitative example only, with reference to the accompanying drawings, in which:
High-heeled footwear are usually known to be shoes with a heel between 5 and 13 cm (or higher). While the invention is particularly advantageous in connection with high-heeled shoes, it can also improve the comfort of flat shoes (no heel), low-heeled shoes (less than 2.5 cm) or mid-heeled shoes (between 2.5 and 5 cm), including ‘ballerinas’ or boots.
In the embodiment shown in
Starting from the base 10, islands 8 are arranged to form cushioning pads in the insole 20. Islands 8 are arranged in two discrete islands 8a, 8b. The term “discrete island” refers to the fact that the two islands 8a, 8b are separate and not joined together. As shown in
The islands 8a, and 8b are typically irreversibly attached to the base 10, preferably by glue or other adhering means. The glue may be applied across the whole surface of islands 8, or may be provided in discrete amounts before adhering to the base 10.
Each of islands 8a and 8b preferably comprise two layers. The first layer 4 is preferably a resilient material and forms the lower layer of the insole 20, which is in direct contact with the base of the shoe 21. The second layer 3 is preferably a viscoelastic foam and is typically adhered on top of the first layer 4. First layer 4 is optional. In an embodiment where the first layer 4 is not provided, the second layer 3 can instead be adhered directly to the base 10 of the shoe 21. Alternatively, the first layer 4 may be arranged above the second layer 3.
In
The first layer 4 is preferably a resilient material and is typically a polyurethane foam, but could also be an ethylene-vinyl acetate (EVA) foam, silicone, rubber or any other suitable resilient material providing sufficient support. The first layer 4 typically has a higher resilience than second layer 3. The first layer 4 optionally further comprises odour-controlling and/or anti-microbial additives to prevent foot odours from developing inside the shoe 21. These odour-controlling and/or anti-microbial ingredients may also be provided in other layers instead of, or in addition to, first layer 4.
The first layer 4 provides the insole with support and shock absorption. By arranging the first layer 4 only in the heel and toe regions of the insole 20 and not across the whole longitudinal length of the insole 20, optimum comfort is achieved and material costs are reduced. However, support is still provided to the heel and toe areas of the foot.
The second layer 3 is preferably an open-celled foam or a memory foam.
The term “open-celled foam” refers to the pockets of gas trapped within the foam. In an open-celled foam, the pockets of gas connect with each other, allowing fluids to pass through the foam's entire structure. In contrast, a closed-celled foam has discrete pockets of gas. Open-celled foams are known for being more resistant to permanent deformation after repeated compressions than closed-celled foams. They are also known for their softness and breathability (porosity).
The term ‘memory foam’ is used to describe a foam that is sensitive to pressure and temperature, which allows the foam to mould to the shape of the wearer's foot, for example. They are known for their ability to return to their original shape after being compressed. Therefore, as the foot moves and shifts around in the shoe, a memory foam is able to constantly and gradually readjust to the changes in pressure and distribute the pressure evenly. This provides the insole with increased cushioning, comfort and stability.
Memory foams are typically open-celled polyurethane foams. Second layer 3 is thus ideally an open-celled polyurethane memory foam.
An example of such foams are the CONFOR® foams manufactured by Trelleborg Applied Technology. The first viscoelastic foam is preferably CONFOR® CF-42 or CF-45, but may optionally be CONFOR® CF-40 or CF-47.
Second layer 3 preferably has a density of between 80 and 110 kg/m3 measured with American Society for Testing and Materials (ASTM) standard ASTM D3574-95 Test A, more preferably of between 85 and 100 kg/m3, even more preferably of between 90 and 95 kg/m3 and most preferably of 93 kg/m3.
Second layer 3 preferably has a compression set (a measure of the permanent deformation of a foam after it has been compressed between two metal plates for a controlled time period and temperature condition) of between 0 and 1% measured with ASTM D3574, compressed by 25% for 22 hours at 70 degrees Celsius, more preferably a compression set of between 0.2 and 1%, even more preferably of between 0.3 and 1% and most preferably of 0.4% or 0.9%.
Second layer 3 preferably has an indentation force deflection (related to firmness of the foam) of between 10 and 50 lb/(50 in2) measured with ASTM D3574 Test B1 at a 25% deflection, 22 degrees Celsius and 50% relative humidity. More preferably, the second layer 3 has an indentation force deflection of between 20 and 40 lb/(50 in2), even more preferably of between 23 and 37 lb/(50 in2) and most preferably of 26 lb/(50 in2) or 34 lb/(50 in2).
Second layer 3 preferably has a ball rebound resilience value of between 0 and 3.5% measured with ASTM D3574, more preferably of between 0.5 and 3.0%, even more preferably of between 0.8 and 2.6% and most preferably of 1.0% or 2.4%.
Second layer 3 preferably has a tensile strength of between 90 and 200 kPa measured with ASTM D3574, 51 cm/min at 22 degrees Celsius, more preferably of between 110 and 170 kPa, even more preferably of between 120 and 160 kPa and most preferably of 125 kPa or 154 kPa.
Second layer 3 preferably has an elongation of between 90 and 150% measured with ASTM D3574 at 51 cm/mm and 22 degrees Celsius, more preferably of between 100 and 120%, even more preferably of between 105 and 115%, and most preferably of 108% or 109%.
Second layer 3 typically consists of only one particular foam but may optionally comprise multiple foams preferably provided in layers, each foam having a different set of properties. This allows for fine-tuning of the cushioning, comfort and support provided by second layer 3.
As shown in
Third layer 2 is typically foot-shaped and preferably extends across the whole width of the insole. Third layer 2 is typically flat when no pressure is applied but can be contoured in order to provide more support to particular areas of the foot, if required.
Third layer 2 preferably comprises a viscoelastic foam. Third layer 2 is preferably an open-celled foam or a memory foam, with the terms ‘open-celled foam’ and ‘memory foam’ having the same meanings as explain above. Third layer 2 is thus ideally an open-celled polyurethane memory foam. Third layer 2 provides the insole with additional cushioning, comfort, support and stability.
An example of such foams are PORON® foams manufactured by Rogers Corporation. The viscoelastic foam of third layer 2 is preferably one of: PORON® Plus Cushioning, PORON® Performance Cushioning, PORON® Slow Rebound Cushioning and PORON® XRD™ Extreme Impact Protection.
The third layer 2 preferably has a density of between 120 and 450 kg/m3 measured with American Society for Testing and Materials (ASTM) standard ASTM D3574-95 Test A. For example, the third layer 2 has a density of between 210 and 360 kg/m3 (such as in product PORON® Plus Cushioning), or a density of between 210 and 450 kg/m3 (such as in product PORON® Performance Cushioning), or a density of 240 kg/m3 (such as in product PORON® Slow Rebound Cushioning) or a density of between 120 and 450 kg/m3 (such as in product PORON® XRD™ Extreme Impact Protection).
Third layer 2 preferably has a compression set (a measure of the permanent deformation of a foam after it has been compressed between two metal plates for a controlled time period and temperature condition) of between 0 and 15% measured with ASTM D3574 Test D at 70 degrees Celsius, more preferably a compression set of between 5 and 15%, even more preferably of between 7 and 13%, even more preferably between 9 and 11%, and most preferably of 10%.
Third layer 2 preferably has a compression force deflection (related to firmness of the foam) of between 0 and 350 kPa measured at 5 mm/min, strain rate force measured at 25% deflection. For example, the third layer 2 has an compression force deflection of between 20 and 110 kPa (such as in product PORON® Plus Cushioning), of between 35 and 350 kPa (such as in product PORON® Performance Cushioning), of between 1 and 150 kPa (such as in product PORON® Slow Rebound Cushioning Series), or of between 5 and 160 kPa (such as in product PORON® XRD™ Extreme Impact Protection).
Third layer 2 preferably has a ball rebound resilience value of between 0 and 30% measured with ASTM D2632-96, vertical rebound. For example, the third layer 2 has a ball rebound resilience of between 20 and 30% (such as in product PORON® Plus Cushioning), of between 10 and 25% (such as in product PORON® Performance Cushioning), or of between 1 and 15% (such as in product PORON® Slow Rebound Cushioning Series).
Third layer 2 preferably has a tensile strength of between 90 and 1100 kPa measured with ASTM D3574 Test E. For example, the third layer 2 has a tensile strength of between 240 and 570 kPa (such as in product PORON® Plus Cushioning), of between 420 and 1100 kPa (such as in product PORON® Performance Cushioning), of between 85 and 760 kPa (such as in product PORON® Slow Rebound Cushioning Series), or of between 160 and 1100 kPa (such as in product PORON® XRD™ Extreme Impact Protection).
Third layer 2 preferably has an elongation of between 90 and 150% measured with ASTM D3574 Test E. For example, the third layer 2 has an elongation of 100% (such as in product PORON® Plus Cushioning and product PORON® Performance Cushioning), of between 90 and 150% (such as in product PORON® Slow Rebound Cushioning Series), or of over 145% (such as in product PORON® XRD™ Extreme Impact Protection).
The third layer 2 typically consists of only one particular foam but may optionally comprise multiple foams preferably provided in layers, each foam having a different set of properties. This allows for fine-tuning of the cushioning, comfort and support provided by third layer 2.
The insole 20 according to the invention therefore typically comprises at least two viscoelastic foams, wherein the two viscoelastic foams are preferably different. Thus, although the two foams can both be open-celled memory foams, they are different in that they have different physical characteristics. The third layer 2 is preferably firmer than the second layer 3 in order to provide stability as well as comfort for the foot. The second layer 3 is preferably highly damped, or has a slow recovery, or has a low resilience in order to provide a high degree of cushioning. Third layer 2 and the second layer 3 preferably complement each other and provide an enhanced level of comfort and/or cushioning and/or support that would otherwise not be provided if the insole 20 comprised only one viscoelastic foam layer.
As shown in
Fourth layer 1 is preferably a soft material, or a material which provides a soft feeling to the wearer. Fourth layer 1 is also preferably a porous material and thus allows fresh air to circulate in and out of the insole. This provides a number of advantages, such as helping to prevent odours and allowing the shoe to dry more quickly when wet. Fourth layer 1 can be made from a synthetic material or fibre, such as nylon or LYCRA®. Alternatively, the first material 1 is a leather-like material, such as leather, sheepskin or pigskin.
As shown in
The insole 20 according to the invention therefore provides cushioning, comfort, support and stability across the majority of the foot due to continuous layers 1 and 2. The islands 8a, 8b result in raised areas at the heel region and the toe region of the insole 20, which provide extra cushioning, comfort, support and stability for the heel and toe areas of the foot. Furthermore, by arranging the first layer 4 and the second layer 3 only in a heel region and a toe region of the insole 20, less material is required to provide an improved level of comfort and therefore material costs for manufacturing the insole 20 are lowered.
The thickness of the fourth layer 1 is typically less than 3 mm, preferably less than 2 mm and more preferably less than 1 mm. The thickness of the third layer 2, if present, is typically between 0.3 and 11 mm and preferably between 3 and 9 mm. The thickness of the second layer 3, if present, is typically between 0.3 and 10 mm, preferably between 2 and 8 mm and most preferably between 3 and 5 mm. The thickness of the first layer 4, if present, is typically between 0.3 and 5 mm and preferably between 1 and 3 mm.
The thickness of the complete insole 20 (in a non-compressed state) is thus typically between 1.2 and 50 mm, preferably between 7 and 19 mm, more preferably between 9 and 14 mm. Once compressed, e.g. with a foot compressing the insole in situ in a shoe, the insole may be considerably thinner.
Fourth layer 1, third layer 2, second layer 3 and first layer 4 are preferably uniform in thickness, but each may have a non-uniform thickness across the length and/or the width of the insole in order to provide support to particular areas of the foot.
The insole 20 may also comprise a cork material, preferably arranged only in a heel region and a toe region of the insole. The cork material is typically arranged between second layer 3 and first layer 4 or below first layer 4. The cork material is preferably the same length, width and shape as at least one of second layer 3 and first layer 4. The cork material helps to absorb moisture, which is a cause of unpleasant odours in footwear.
It is not necessary that the insole comprises both fourth layer 1 and third layer 2 in combination, although it is preferred. For example, fourth layer 1 may be adhered directly on top of the second layer 3, without providing third layer 2 in between them. Alternatively, third layer 2 may be adhered on top of second layer 3, without providing fourth layer 1 above third layer 2.
The size, shape and arrangement of the islands and the arrangement of the perforations shown in
In
Stitching of the layers is of course not limited to this embodiment and can be provided in the integral shoe embodiment. For example, layers 1 and 2 in
The cavities are positioned at a heel end and a toe end of the insole 40. The second layer 3 is preferably arranged between third layer 2 and first layer 4. Third layer 2 covers and surrounds both second layer 3 and first layer 4. The bottom surface of first layer 4 is level with the bottom surface of third layer 2. The islands 8 may be held in the cavities by glue or other adhering means. In contrast to the embodiment wherein third layer 2 was adhered on top of the islands 8, the overall thickness of insole 40 is minimised here, whilst still providing the advantages of combining multiple layers of materials with varying properties. Third layer 2 may optionally only partially cover and/or surround the islands 8.
Arranging the islands 8 in cavities of third layer 2 or fourth layer 1 is of course not limited to this embodiment and can be provided in the embodiments described above. For example, islands 8a and 8b in
The thicknesses of the layers, relative thicknesses of islands 8 and relative thicknesses of the layers within each island 8 are of course not limited to the illustrated embodiment in
Changing the overall thickness of the islands 8 relative to the thickness of the third layer 2 or fourth layers 1 is of course not limited to this embodiment and can be provided in the other embodiments. For example, the thickness of islands 8a and 8b in
For European shoe sizes between 36 and 39, the longitudinal length of each of the discrete islands is typically greater than 4 cm, preferably greater than 4.5 cm, and more preferably greater than 5 cm. The width of each of the discrete islands is typically greater than 3 cm, preferably greater than 3.4 cm, and more preferably greater than 3.8 cm.
For European shoe sizes between 40 and 45, the longitudinal length of each of the discrete islands is typically greater than 5 cm, preferably greater than 5.5 cm, and more preferably greater than 6 cm. The width of each of the discrete islands is typically greater than 3.5 cm, preferably greater than 4 cm, and more preferably greater than 4.4 cm.
As shown in
The inner pad material 541 is preferably a mesh spacer fabric. A mesh spacer fabric is shown in
Compared to a cushioning pad pocket containing only air, use of inner pad material 541 provides a cushioning pad that is softer, more flexible and resilient and can handle a large load. The inner pad material 541 also provides redundancy in the event that the cushioning pad 54 leaks air, as the inner pad material 541 will still provide some level of cushioning. Alternatively, the inner pad material 541 can be another material having similar properties, such as a foam, preferably a viscoelastic foam, such as the ones already described herein.
The outer pad material 542 is preferably impermeable to water so that the performance or durability of the cushioning pad 54 is not negatively affected in wet conditions. The outer pad material 542 is preferably thin and lightweight and is typically made from at least one of: polypropylene, polyethylene, nylon, polyvinyl chloride and polytetrafluoroethylene. The outer pad material 542 preferably completely encloses the inner pad material 541 and is typically sealed using heat or adhesive means to form a sealed perimeter around the inner pad material 541. In a plan view, the outer pad material 542 typically extends from the perimeter of the inner pad material 541 by 0.5-2 cm in all directions.
An optional shock-absorbing layer 53 may also be arranged between the cushioning pad 54 and third layer 52 to provide the insole 50 with additional cushioning and shock-absorption. The shock-absorbing layer 53 typically extends continuously from one end of the insole to the other end of the insole 50 in a longitudinal direction but may be localised in one region only (e.g. only in the heel region or only in the toe region). The shock-absorbing layer 53 is typically adhered to the top of the cushioning pad 54 and optionally also to the top of the base 57 in a region of the base 57 not covered by the cushioning pad 54.
The shock-absorbing layer 53 is typically foot-shaped and preferably extends across the whole width of the insole 50. The shock-absorbing layer 53 preferably comprises a viscoelastic foam. The shock-absorbing layer 53 is preferably an open-celled foam or a memory foam, with the terms ‘open-celled foam’ and ‘memory foam’ having the same meanings as explained above. The shock-absorbing layer 53 is thus preferably an open-celled polyurethane memory foam. An example of such foams are the CONFOR® foams manufactured by Trelleborg Applied Technology. The shock-absorbing layer 53 is preferably formed from CONFOR® CF-42 or CF-45, but may optionally be CONFOR® CF-40 or CF-47.
The shock-absorbing layer 53 preferably has a density of between 80 and 110 kg/m3 measured with American Society for Testing and Materials (ASTM) standard ASTM D3574-95 Test A, more preferably of between 85 and 100 kg/m3, even more preferably of between 90 and 95 kg/m3 and most preferably of 93 kg/m3.
The shock-absorbing layer 53 preferably has a compression set (a measure of the permanent deformation of a foam after it has been compressed between two metal plates for a controlled time period and temperature condition) of between 0 and 1% measured with ASTM D3574, compressed by 25% for 22 hours at 70 degrees Celsius, more preferably a compression set of between 0.2 and 1%, even more preferably of between 0.3 and 1% and most preferably of 0.4% or 0.9%.
The shock-absorbing layer 53 preferably has an indentation force deflection (related to firmness of the foam) of between 10 and 50 lb/(50 in2) measured with ASTM D3574 Test B1 at a 25% deflection, 22 degrees Celsius and 50% relative humidity. More preferably, the shock-absorbing layer 53 has an indentation force deflection of between 20 and 40 lb/(50 in2), even more preferably of between 23 and 37 lb/(50 in2) and most preferably of 26 lb/(50 in2) or 34 lb/(50 in2).
The shock-absorbing layer 53 preferably has a ball rebound resilience value of between 0 and 3.5% measured with ASTM D3574, more preferably of between 0.5 and 3.0%, even more preferably of between 0.8 and 2.6% and most preferably of 1.0% or 2.4%.
The shock-absorbing layer 53 preferably has a tensile strength of between 90 and 200 kPa measured with ASTM D3574, 51 cm/min at 22 degrees Celsius, more preferably of between 110 and 170 kPa, even more preferably of between 120 and 160 kPa and most preferably of 125 kPa or 154 kPa.
The shock-absorbing layer 53 preferably has an elongation of between 90 and 150% measured with ASTM D3574 at 51 cm/mm and 22 degrees Celsius, more preferably of between 100 and 120%, even more preferably of between 105 and 115%, and most preferably of 108% or 109%.
Alternatively, the shock-absorbing layer 53 could be formed of an ethylene-vinyl acetate foam.
The shock-absorbing layer 53 typically consists of only one particular foam but may optionally comprise multiple foams preferably provided in layers, each foam having a different set of properties. This allows for fine-tuning of the cushioning, comfort and support provided by shock-absorbing layer 53.
In the case that the insole 50 according to the present embodiment does not contain the shock-absorbing layer 53, third layer 52 is preferably adhered to the top of the cushioning pad 54 and optionally also to the top of the base 50 in a region of the base 50 not covered by the cushioning pad 54.
The insole 50 of
For both the integral insole 50 and the removable insole 60, the cushioning pad 54 may also be arranged in cavities of the shock-absorbing layer 53 (if present) or the third layer 52 (if the shock-absorbing layer 53 is not present), in a similar manner to that described for the insole 30 shown in
The above-described insoles can be used in many types of footwear, particularly in items of footwear comprising a heel, where the heel area is raised above the toe area. The above-described insoles are thus particularly advantageous when used in shoes having a heel exceeding 4 cm, for example stiletto shoes, as they provide increased cushioning, comfort, support and stability, not just across the whole foot but also in the heel and toe regions, where pain is most likely to occur.
The present invention also includes a stiletto shoe integrally or removably incorporating any of the insoles as described herein.
The present invention also includes a method for making an insole for footwear. In one broad form of the invention, such a method would include providing two islands or a cushioning pad and a continuous piece of fabric and adhering the continuous piece of fabric to the two islands or cushioning pad. For an insole integrated with a high-heeled shoe or other item of footwear, the materials of the insole may be adhered together in isolation, or they may be prepared by adhering each material piece by piece onto the item of footwear.
For the integral insoles or the removable insoles the materials and layers of the insole may be stitched together. For example, third layer 2 and fourth layer 1 may be stitched together around the outer edge to hold them together. An anti-slip layer 7 may be adhered or attached to the bottom layer of the removable insoles, for preventing slippage between the removable insole and the inside of the shoe.
Thus, a typical manufacturing method for the insoles 20, 30, 40 will comprise providing a first layer of material, adhering to that a second layer of material, adhering together two materials to form a heel island, adhering together two materials to form a toe island, and then adhering the heel and toe islands to the second layer of material. The materials are preferably as described above.
An alternative manufacturing method for the insoles 20, 30, 40 comprises adhering together two materials, and cutting out a heel island and a toe island from the adhered layers, followed by adhering the heel and toe islands to a continuous layer of material.
A typical manufacturing method for the insoles 50, 60 comprises enclosing an inner pad material within an outer pad material, hermetically sealing the outer material to form a cushioning pad having an inner pocket containing at least the inner pad material and air and adhering a continuous piece of material on to the cushioning pad such that the cushioning pad is arranged in a heel region and/or a toe region of the insole.
In more detail, a typical manufacturing method for the cushioning pad 54 component of the insole 50, 60 preferably comprises sandwiching an inner pad material 541 between two layers of an outer pad material 542, such that the inner pad material is entirely surrounded by both layers of the outer pad material 542 in a plan view. The perimeter of the two layers of the outer pad material 542 are then sealed together using heat or adhesive means (e.g. glue), to form an enclosure or pocket containing at least the inner pad material 541 and air.
Alternatively, the outer pad material 542 may be provided as a clam structure, into which an inner pad material 541 is placed, before closing and sealing the outer pad material 542.
Claims
1. An insole for footwear comprising:
- a first material extending continuously from one end of the insole to the other end of the insole in a longitudinal direction; and
- a cushioning pad arranged in a heel region and/or a toe region of the insole;
- wherein the cushioning pad comprises an inner pad material and an outer pad material, the outer pad material enclosing the inner pad material to form a hermetically sealed pocket containing at least air and the inner pad material.
2. An insole according to claim 1, wherein said cushioning pad is arranged below the first material.
3. An insole according to claim 1, wherein the inner pad material is a mesh spacer fabric.
4. An insole according to claim 3, wherein the mesh spacer fabric has a structure comprising a fibrous core sandwiched between two mesh layers, and the inner pad material comprises two of said structures stacked on top of each other.
5. (canceled)
6. An insole according to claim 1, wherein the inner pad material is a viscoelastic foam, preferably an open-celled viscoelastic foam.
7. (canceled)
8. An insole according to claim 6, wherein the inner pad material is a polyurethane foam.
9. (canceled)
10. An insole according to claim 1, wherein the outer pad material is made from at least one of: polypropylene, polyethylene, nylon, polyvinyl chloride and polytetrafluoroethylene.
11. An insole according to claim 1, wherein the first material is a viscoelastic foam, preferably an open-celled viscoelastic foam, preferably a polyurethane foam.
12. (canceled)
13. (canceled)
14. An insole according to claim 11, wherein the first material has one or more of the following properties:
- a) a density of between 120 and 450 kg/m3 measured with ASTM D3574-95 Test A;
- b) a compression set of between 0 and 15% measured with ASTM D3574 Test D at 70 degrees Celsius;
- c) a compression force deflection of between 0 and 350 kPa measured at 5 mm/min, strain rate force measured at 25% deflection; and
- d) a ball rebound resilience value of between 0 and 30% measured with ASTM D2632-96, vertical rebound.
15. An insole according to claim 1, further comprising an upper layer arranged above the first material and extending continuously from one end of the insole to the other end of the insole in a longitudinal direction.
16. An insole according to claim 15, wherein the upper layer comprises perforations.
17. (canceled)
18. An insole according to any one of claim 15, wherein the upper layer is porous.
19. (canceled)
20. (canceled)
21. An insole according to claim 1, further comprising an intermediate layer arranged between the cushioning pad and the first material.
22. An insole according to claim 21, wherein the intermediate layer is a viscoelastic foam, preferably an open-celled viscoelastic foam, preferably a polyurethane foam.
23. (canceled)
24. (canceled)
25. An insole according to claim 22, wherein the intermediate layer has one or more of the following properties:
- a) a density of between 80 and 100 kg/m3 measured with ASTM D3574-95 Test A;
- b) a compression set of between 0 and 1% measured with ASTM D3574, compressed by 25% for 22 hours at 70 degrees Celsius;
- c) an indentation force deflection of between 10 and 50 lb/(50 in2) measured with ASTM D3574 Test B1; and
- d) a ball rebound resilience value of between 0 and 3.5% measured with ASTM D3574.
26. An insole according to claim 21, wherein the intermediate layer is an ethylene-vinyl acetate foam.
27. (canceled)
28. (canceled)
29. (canceled)
30. An item of footwear comprising an insole according to claim 1.
31. An item of footwear according to claim 30, further comprising a heel, wherein said heel is preferably higher than 4 cm.
32. A high-heeled shoe comprising an insole, said insole comprising a cushioning pad arranged in a heel region and/or in a toe region of the insole and further comprising a continuous material over said cushioning pad, wherein the cushioning pad comprises an inner pad material and an outer pad material, the outer pad material arranged around the inner pad material to form a hermetically sealed pocket containing at least air and the inner pad material.
33. A method of making an insole for footwear comprising:
- enclosing an inner pad material and air with an outer pad material;
- hermetically sealing the outer pad material to form a cushioning pad having an inner pocket containing at least the inner pad material and air;
- adhering a continuous piece of material to the cushioning pad such that the cushioning pad is arranged in a heel region and/or a toe region of the insole.
34. (canceled)
Type: Application
Filed: Feb 11, 2015
Publication Date: Dec 15, 2016
Inventor: Nanna Liv PEDERSEN (London)
Application Number: 15/118,173