The present invention relates to insoles for footwear.

Foot 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, US 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, US 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.

The 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: a) a density of between 120 and 450 kg/m ³ 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:

a) a density of between 80 and 100 kg/m ³ 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 in ² ) measured with ASTM D3574 Test

Bl; 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/m ³ 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 in ² ) measured with ASTM D3574 Test Bl; 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/m ³ 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:

Figure 1 is a perspective exploded side view of part of a high-heeled shoe comprising an insole according to the invention.

Figure 2 is a top view of a removable insole according to the invention.

Figure 3 is a bottom view of a removable insole according to the invention.

Figure 4 is a cross-sectional side view of an insole according to the invention. Figure 5 is a top view of a heel portion of an insole according to the invention.

Figure 6 is a cross-sectional end view of an insole according to the invention.

Figure 7 is perspective exploded side view of a high heeled shoe comprising an insole according to the invention.

Figure 8 is a sectional side view of a mesh spacer fabric used in the insole shown in Figure 7.

Figure 1 shows part of a high-heeled shoe according to the invention which comprises a heel 9 and a base 10. The high-heeled shoe is of a typical shape, wherein the heel region of the shoe is raised in comparison with the toe region. The base of the shoe typically slopes down from the heel region to the toe region with a smooth gradient. Heel 9 tapers from the top of the heel to the bottom of the heel; however, the heel can be of any shape and size. The upper part of the shoe which covers the foot is not shown for clarity of the drawing; however, an upper part is typically present. The shoe is made of conventional shoe materials that preferably provide durability, grip and/or protection from the weather.

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 Figure 1, an insole 20 for the high-heeled shoe 21 is provided integrally with the shoe 21 itself. However, as is described later, the insole could also be provided as a removable insole to be inserted into the shoe as required. As is conventional, the insole 20 has a bottom (shoe side), a top (foot side), a heel end and a toe end. In the present embodiment, multiple layers of material 1, 2, 3, 4 are arranged on the base 10 of the high-heeled shoe 21.

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 Figure 1, there is a central region of space (between the heel and toe portions) into which islands 8 do not extend. A first discrete island 8 a is provided in a heel region of the insole 20 and a second discrete island 8b is provided in a toe region of the insole 20. The heel island 8a is typically in the heel end of the insole 20 and covers a partial or substantial region of the heel of a human foot. The toe island 8b is typically in the toe end of the insole 20 and covers a partial or substantial region of the toes and/or metatarsal region of the foot.

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 Figure 1, it can be seen that the first layer 4 and the second layer 3 are essentially the same shape and are placed directly on top of each other. It can also be seen that the discrete islands 8a, 8b are narrower in width than the base 10 and do not extend to the extreme ends of the insole of the shoe 21. In other words, in a plan view, there is a gap between the edge of the shoe 21 and the edges of the discrete islands 8a, 8b, which extends all the way around the discrete islands. As an alternative to what is shown, the discrete islands 8a, 8b can extend across the whole width of the insole of the shoe 21 and/or extend up to the outer edge of the insole of the shoe 21 in a longitudinal direction. For example, the heel island 8a may extend to the rear heel edge of the insole and the toe island 8b can extend to the front toe edge of the insole.

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/m ³ measured with American

Society for Testing and Materials (ASTM) standard ASTM D3574-95 Test A, more preferably of between 85 and 100 kg/m ³ , even more preferably of between 90 and 95 kg/m ³ and most preferably of 93 kg/m ³ .

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 in ) measured with ASTM D3574 Test Bl at a 25% deflection, 22 de grees Celsius and 50% relative humidity. More preferably, the second layer 3 has an indentation force deflection of between 20 and 40 lb/(50 in ), even more preferably of between 23 and 37 lb/(50 in ) and most preferably of 26 lb/(50 in ² ) or 34 1b/(50 in ² ).

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 Figure 1, a third layer 2 is arranged over the islands 8. Third layer 2 is typically arranged continuously from one end of the insole 20 to the other end of the insole 20 in a longitudinal direction. Third layer 2 is typically adhered to the top of second layer 3 and optionally also to the top of the base 10 in the region between the islands 8. Third layer 2 may also be adhered to the first layer 4, if for example, the first layer 4 is larger in a plan view than second layer 3.

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/m ³ 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/m ³ (such as in product PORON® Plus Cushioning), or a density of between 210 and 450 kg/m ³ (such as in product PORON® Performance Cushioning), or a density of 240 kg/m ³ (such as in product PORON® Slow Rebound Cushioning) or a density of between 120 and 450 kg/m ³ (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 5mm/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 Figure 1, a fourth layer 1 is arranged over the third layer 2. Fourth layer 1 is also arranged continuously from one end of the insole 20 to the other end of the insole 20 in a longitudinal direction. Fourth layer 1 is typically foot-shaped (and the same size and shape in plan view as the second layer 2, if present) and preferably extends across the whole width of the insole of the shoe 21. Fourth layer 1 is optionally adhered to the top of third layer 2, or to the islands 8a, 8b if no third layer is present.

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 Figure 1, fourth layer 1 also comprises mechanically made perforations 5 arranged in the heel region and the toe region of the insole 20. The perforations typically extend from the top surface of fourth layer 1 through to the bottom surface of fourth layer 1. The perforations may have diameters in the range of 0.2mm to 2mm. When pressure is applied to and released from the fourth layer 1, air is pushed through the material pores and/or perforations 5 into the underlying foam materials of the insole 20, which creates a 'pumping' action and increases the level of cushioning that the entire insole 20 provides. The perforations 5 need not be confined to the heel region and/or toe region of the insole 20, but may optionally be arranged over the entire surface of fourth layer 1, or may exist only in the toe region, or only in the heel region, or in other regions that are not the toe region or the heel region.

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.

Figures 2 and 3 show an alternative embodiment for a removable insole 30. This insole 30 is configured to be removable from a standard shoe 21. The removable insole 30 is intended to be positioned on the insole board or sock liner of a high-heeled shoe. Preferably the removable insole 30 is flexible enough such that it readily conforms to the shape of the upper surface of the shoe's insole board or sock liner. By providing the insole 30 as a removable insert, the removable insole 30 can be inserted into items of footwear that were previously too uncomfortable to wear, without having to modify the footwear itself. Furthermore, the removable insole 30 can be swapped between multiple items of footwear, which increases convenience and decreases cost for the user.

Figure 2 shows a top view of such a removable insole 30. The general construction of the removable insole is the same as described above for the integral insole 20. The first layer 4, the second layer 3, the third layer 2 and the fourth layer 1 are all shown in exemplary areas of the removable insole 30. It can be seen that the islands 8 formed by first layer 4 and second layer 3 may have an elliptical or oval shape in a plan view. Furthermore, as shown, the islands 8a and 8b can have a different length, width and shape to each other. For example, heel island 8a is elongated in a longitudinal direction, whereas toe island 8b is elongated in a width direction. Furthermore, at least a portion of island 8b extends across the whole width of the insole.

Perforations are arranged over the toe region only, but may optionally be arranged over the heel region as well, or over the heel region only, or over other regions of the insole, or over the whole surface of the insole, as with the above embodiment.

The size, shape and arrangement of the islands and the arrangement of the perforations shown in Figures 2 and 3 can of course be applied to the embodiment of Figure 1 described above. For example, islands 8a and 8b in Figure 1 may have a different length, width, and shape to each other.

In Figures 2 and 3, fourth layer 1 and third layer 2 are both foot-shaped and extend continuously from one end of the insole 30 to the other end of the insole 30 in a longitudinal direction. Fourth layer 1 and third layer 2 are essentially the same shape and size in a plan view. The outer edges of fourth layer 1 and third layer 2 may be stitched together with stitches 6 to hold the layers together. Stitching also provides protection against wear and tear around the edges of the removable insole. Stitching may be provided around the whole perimeter of the insole, as shown in Figure 2, or the stitching may be provided only in certain areas.

Alternatively or additionally, fourth layer 1 and third layer 2 may be adhered together using glue or other adhering means. The first layer 4 and second layer 3 may also be held together by stitches 6. Additionally, the discrete islands 8a, 8b may be attached to third layer 2 by stitches or glue or other adhesive means.

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 Figure 1 may be stitched together in the same way as above, before or after being attached to islands 8 a and 8b.

Figure 3 shows a bottom view of the removable insole 30 shown in Figure 2. Attached to the bottom of the removable insole 30 is an anti-slip layer 7, which prevents slippage between the removable insole 30 and the inside of the shoe 21. The anti-slip layer 7 can comprise a rough material or a material with a patterned surface, such as grooves, in order to increase friction between the removable insole 30 and the base

10 of the shoe 21. The anti-slip layer 7 preferably extends continuously from one end of the insole 30 to the other end of the insole 30 in a longitudinal direction. Optionally, the anti-slip layer 7 is the same shape and size in a plan view as fourth layer 1 and/or third layer 2. Alternatively, the anti-slip layer 7 may be arranged only in a heel portion and a toe portion, or in any other portion(s) on the bottom of the removable insole 30.

Figures 4 to 6 show the islands 8 formed by second layer 3 and first layer 4 in more detail, and show an alternative arrangement for how the islands 8 can be arranged in the insole 40.

Figure 4 shows a longitudinal cross-sectional side view of another embodiment of the insole 40, wherein the islands 8 are arranged in cavities within third layer 2. The heel end of the insole 30 is on the left side of the figure. Fourth layer 1 is not shown, but is preferably present and may be arranged on top of third layer 2. Alternatively, the islands 8 may be arranged in cavities within fourth layer 1, when the insole 40 is not provided with third layer 2.

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

Figure 1 may be arranged in cavities of third layer 2.

Figure 4 also shows third layer 2 having a greater thickness at the heel end of the insole 40 compared to the toe end of the insole 40. Third layer 2 may indeed have a non-uniform thickness distribution in order to provide extra support to particular areas of the foot. Thus, for example, the toe end of the insole 40 may be thicker than the heel end, or the centre of the insole 40 may be thicker than the outer areas. Fourth layer 1 may also have a non-uniform thickness in the same manner as third layer 2. The first layer 4 and the second layer 3 may also have non-uniform thicknesses as required.

Figure 4 also shows that islands 8a and 8b may have different thicknesses to each other. In particular, Figure 4 shows island 8b to be thinner overall than island 8a. However, island 8a could be the same thickness or thinner overall than island 8b.

Figure 4 also shows a thickness ratio between the two layers in each island 8 of approximately 1: 1.

However, the thickness ratio may be adjusted as required. The thickness ratio between the layers in one of the islands 8a, 8b may be different to the thickness ratio between the layers in the other one of the islands 8a, 8b.

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 figures 4-6 and can be provided in the other embodiments. For example, layers 1-4 in Figure 1 may have non-uniform thicknesses and different thicknesses relative to each other. Figure 5 shows that second layer 3 and first layer 4 are typically the same length, width and shape and are placed directly on top of each other. Figure 5 also shows that the islands 8 may also have a rounded-off rectangular shape, in addition to the other shapes already described herein.

Figure 6 shows that the second layer 3 and the first layer 4 in at least the heel portion are each narrower than the total width of the insole (i.e. the width of fourth layer 1 and/or third layer 2). The material costs of the insole are thereby lowered, whilst still providing increased comfort in the heel and toe regions of the foot. The width of the second layer 3 and first layer 4 may be increased or decreased as required, and may be the same width of the insole if desired.

Figures 4 and 6 also show that the overall thickness of the discrete islands is approximately half that of the third layer 2. However, the thickness of the discrete islands may also be increased or decreased relative to third layer 2 in order to provide additional comfort, cushioning or support as required.

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 Figure 1 may be adjusted relative to the thickness of third layer 2 or fourth layer 1.

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.

Figure 7 shows a high-heeled shoe 55 according to an embodiment of the invention. The insole 50 of the present embodiment is similar to the insole 20 of Figure 1, except that the islands 8 are replaced with a cushioning pad 54 arranged in a heel region and/or a toe region of the insole 50. The insole 50 shown in Figure 7 comprises a cushioning pad 54, an optional shock-absorbing layer 53, third layer 52 and fourth layer 51. Third layer 52 and fourth layer 51 are substantially the same as third layer 2 and fourth layer 1 as described for the embodiments of Figure 1-6 and are not further described in detail here. Other features of the embodiments of Figure 1-6 as described herein may be incorporated into the present embodiment without any substantial modifications.

As shown in Figure 7, starting from the base 57, a cushioning pad 54 is arranged in the insole 50. The cushioning pad 54 can be arranged in a heel region and/or toe region of the insole 50. In Figure 7, the heel cushioning pad 54 is visible. The shape and size of the cushioning pad 54 is similar to the shape and size of the previously described islands 8 of the embodiments of Figures 1-6. The cushioning pad 54 preferably comprises an outer pad material 541 enclosing an inner pad material 541 to form an hermetically sealed pocket containing at least air and the inner pad material 541.

The inner pad material 541 is preferably a mesh spacer fabric. A mesh spacer fabric is shown in Figure 8. The mesh spacer fabric is conventionally porous and typically has a multi-layered structure comprising a fibrous core sandwiched between two mesh layers. The fibrous core typically comprises fibres orientated substantially perpendicular to the upper and lower mesh layers, linking the two layers together. The mesh spacer fabric is typically made from a synthetic fibre such as nylon or polyester and preferably has a thickness of 2-5 mm, more preferably 3 mm. A typical mesh spacer fabric is marketed as '3D spacer fabric' or '3D mesh'. The inner pad material 541 is preferably formed of two layers of the mesh spacer fabric stacked on top of each other but may also be formed of one layer or more than two layers of the mesh spacer fabric.

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 54 land 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/m ³ measured with American Society for Testing and Materials (ASTM) standard ASTM D3574-95 Test A, more preferably of between 85 and 100 kg/m ³ , even more preferably of between 90 and 95 kg/m ³ and most preferably of 93 kg/m ³ .

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 in ² ) measured with ASTM D3574 Test Bl 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 in ² ), even more preferably of between 23 and 37 lb/ (50 in ² ) and most preferably of 26 lb/(50 in ² ) or 34 lb/(50 in ² ).

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 Figure 7 can also be provided as a removable insole 60. The construction of the removable insole 60 is same as the construction of the removable insole 30 shown in Figures 2 and 3, except that the islands 8 are replaced with the cushioning pad 54, and the shock-absorbing layer 53 is optionally arranged between the cushioning pad 54 and third layer 52.

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 Figures 4-6.

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.