ELECTROSTATIC DISCHARGE INSOLE

Abstract

The present invention discloses an advanced insole for electrostatic discharge footwear. The insole features a base foam layer and a fabric top cover with conductive threads woven into the cover material, providing electrical flow paths from a wearer's foot to the base foam layer. An electrostatic discharge chemical additive is incorporated into the base foam layer, creating polarity channels for an electrical pathway within the foam layer. The insole is designed in a 3D supportive shape for increased foot comfort and interface, including a heel cup and arch support. The edges adjacent the toe region are beveled to accommodate various footwear, and the bottom surface of the base foam layer includes molded-in structures that provide varying degrees of cushioning to different regions of the foot. This novel insole design enhances comfort while ensuring efficient electrostatic discharge, proving advantageous in various footwear applications.

Claims

1. An insole for electrostatic discharge footwear comprising: a base foam layer having a unitary body with a contoured upward-facing shape to follow the shape of a wearer's foot; a fabric top cover having conductive threads woven into the cover material, overlaying the base foam layer and providing electrical flow paths from a foot of a wearer to the base foam layer; and an electrostatic discharge chemical additive added to the base foam layer, creating polarity channels for an electrical pathway within the foam layer.

2. The insole of claim 1, wherein the fabric top cover is constructed of a breathable knit material.

3. The insole of claim 1, wherein the fabric top cover is a woven material.

4. The insole of claim 1, wherein the fabric top cover is a non-woven material.

5. The insole of claim 1, wherein the base foam layer is constructed of polyurethane closed-cell foam, the foam having a durometer in the range of 41c to 47c on the Asker c scale.

6. The insole of claim 1, wherein the electrostatic discharge chemical additive is added to a liquid polyurethane material before it is molded, foamed, and cured.

7. The insole of claim 1, further comprising a semi-rigid support member along at least a portion of a bottom of the base foam layer, the semi-rigid support member providing additional heel and arch support to the base foam layer.

8. The insole of claim 7, wherein the support member includes a conductive material.

9. The insole of claim 7, wherein the support member covers less than half of a lower surface area of the base foam layer.

10. An insole for an electrostatic discharge footwear, the insole being formed in a 3D supportive shape for a foot for increased comfort and foot interface, comprising: a base foam layer; and a fabric top cover having conductive threads woven into the cover material, overlaying the base foam layer and providing electrical flow paths from a foot of a wearer to the base foam layer.

11. The insole of claim 10, wherein the 3D supportive shape comprises a heel cup and an arch support.

12. The insole of claim 10, wherein the edges adjacent the toe region of the insole are beveled to accommodate various footwear.

13. The insole of claim 10, wherein the thickness of the region of the insole beneath the ball and toes of the foot is reduced to accommodate various footwear.

14. The insole of claim 10, wherein the bottom surface of the base foam layer includes molded-in structures that provide relatively more or less cushioning to the foot in various regions of the foot.

15. The insole of claim 14, wherein the molded-in structures comprise ridges and recesses.

16. A method for creating an insole for an electrostatic discharge footwear, the method comprising: providing a base foam layer with a conductive additive; providing a fabric top cover having conductive threads woven into the cover material; and overlaying the fabric top cover on the base foam layer to provide electrical flow paths from a foot of a wearer to the base foam layer.

17. The method of claim 16, wherein the fabric top cover is constructed of a breathable knit material.

18. The method of claim 16, wherein the fabric top cover is a woven material.

19. The method of claim 16, wherein the base foam layer is constructed of polyurethane closed-cell foam having a specific gravity between 0.31 to 0.35 to provide contoured foot support.

20. The method of claim 16, wherein the electrostatic discharge chemical additive is added to a liquid polyurethane material before it is molded, foamed, and cured.

21. The method of claim 16, wherein the additive is conductive particles such as carbon powder.

22. The method of claim 16, further comprising forming the insole into a 3D supportive shape for a foot for increased comfort and foot interface.

23. The method of claim 22, wherein the 3D supportive shape comprises a heel cup and an arch support.

24. The method of claim 22, wherein the edges adjacent the toe region of the insole are beveled to accommodate various footwear.

25. The method of claim 22, wherein the thickness of the region of the insole beneath the ball and toes of the foot is reduced to accommodate various footwear.

26. The method of claim 22, wherein the bottom surface of the base foam layer includes molded-in structures that provide relatively more or less cushioning to the foot in various regions of the foot.

27. Footwear having electrostatic discharge properties, the footwear comprising: an upper to surround at least a portion of the foot of a wearer; an outsole engaged to the upper, the outsole having electrostatic discharge properties embedded therein; an insole comprising: a cushion member having conductive material therein, the conductive material allowing transmission of static electricity from the top of the cushion member to the bottom of the cushion member; a cover material fixed to the cushion member, the cover material being a fabric, the fabric having fabric threads; wherein the fabric includes conductive threads extending through the fabric from top to bottom, the conductive threads being integrated with the fabric threads.

28. The footwear of claim 27, further comprising: a midsole secured to a top of the outsole, the midsole having electrostatic discharge properties embedded therein; and a last board secured to a top of the midsole, the last board having electrostatic discharge properties for discharging static electricity from the insole to the midsole; wherein the insole rests on the midsole.

29. The footwear of claim 28, wherein the cushion member comprises a closed-cell foam having an additive providing electrostatic discharge properties, the cushion member having an upper surface contour substantially following the bottom contour of a foot.

30. The footwear of claim 29, further comprising a semi-rigid support member along at least a portion of a bottom of the cushion member, the semi-rigid support member providing additional heel and arch support to the cushion member.

31. The footwear of claim 28, wherein the last board includes a thread extending therethrough from top to bottom, the thread being conductive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings:

[0023] FIG. 1 illustrates a footwear insole with electrostatic discharge properties including a cushion member, and a fabric top cover.

[0024] FIG. 2 shows a cross-sectional view of the insole positioned within a shoe, emphasizing the interaction between the insole base and the shoe's midsole and/or outsole.

[0025] FIG. 3 depicts a cross-sectional side-elevational view of the insole, showcasing a top cover and a cushion base with formed recesses and ribs on the bottom for differential cushioning.

[0026] FIG. 4A presents a top view of the insole with an ESD fabric top cover and contoured heel and arch to fit the wearer's foot shape.

[0027] FIG. 4B illustrates the fabric top cover material, both the top face and the bottom face.

[0028] FIG. 5 displays the bottom view of an insole featuring a heel cup, arch support, beveled toe edges, and a base cushion structure with ribs and recesses.

[0029] FIG. 6A shows the bottom view of an insole with a beveled toe edge and various structural features.

[0030] FIG. 6B shows a toe-end portion of the bottom view of the insole.

[0031] FIG. 6C shows the toe-end portion in cross section.

[0032] FIG. 7 illustrates the interior of a shoe showing the last board with conductive stitching to create a conductive path from the insole to the midsole or outsole.

[0033] FIG. 8 illustrates an alternate embodiment having a further support structure nested with the foam cushion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Aspects of the present invention are best understood by reference to the description set forth herein. It should be understood, however, that the following descriptions, while indicating preferred aspects and numerous specific details thereof, are given by way of illustration only and should not be treated as limitations. Changes and modifications may be made within the scope herein without departing from the spirit and scope thereof, and the present invention herein includes all such modifications.

[0035] The present invention relates to an insole for an electrostatic discharge (i.e., antistatic) footwear. The insole comprises a base foam layer. This layer can be made from a variety of materials, including but not limited to polyurethane, rubber, or silicone. In the preferred embodiment, the foam layer serves as the primary structure of the insole, providing support and comfort to the wearer's foot.

[0036] The insole further comprises a fabric top cover. This cover preferably includes conductive threads woven into (or otherwise integrated into) the cover material. These threads create an electrical flow path from the foot of the wearer to the base foam layer. This feature is particularly beneficial in environments where electrostatic discharge is a concern, such as in certain industrial or laboratory settings.

[0037] The fabric top cover can be constructed of a breathable knit material. This material allows for air circulation, helping to keep the wearer's foot dry and comfortable. The conductive threads can be woven into the fabric in a variety of patterns and densities, depending on the desired level of conductivity. Alternatively, the fabric top cover can be a woven material. This type of material can provide a different feel and level of comfort to the wearer. The conductive threads can be woven or otherwise integrated into the fabric in a variety of ways, depending on the desired properties of the insole. In another embodiment, the fabric top cover can be a non-woven material. This type of material can offer a different texture and level of durability compared to woven materials. The conductive threads can be integrated into the non-woven material in a variety of ways, depending on the desired properties of the insole.

The electrical flow paths in the fabric top cover extend from side to side and front to back of the insole. This configuration ensures that the entire surface of the foot is in contact with the conductive threads, providing a consistent and reliable electrical flow path to the foam layer.

[0038] The base foam layer of the insole can be constructed of polyurethane closed- cell foam. This type of foam is known for its durability and resilience, making it an excellent choice for an insole material. The foam can be molded into a variety of shapes and sizes to fit a wide range of footwear. The density of the foam can be adjusted to provide good support to the underside of the foot of the wearer while still providing cupping of the heel and cushioning under the entire foot.

[0039] The electrostatic discharge chemical additive is added to the base foam layer. This additive is mixed into the liquid polyurethane material before it is molded, foamed, and cured. The additive creates polarity channels within the foam, providing an electrical pathway within the foam layer.

[0040] In some embodiments, the additive can be conductive particles such as carbon powder. These particles can be mixed into the liquid polyurethane material before it is molded, foamed, and cured. The particles polarize to discharge static electricity through the foam layer, further enhancing the insole's electrostatic discharge properties.

[0041] The insole can be formed into a 3D supportive shape for the foot. This shape can include features such as a heel cup and an arch support, providing increased comfort and foot-to-insole interface. The 3D shape can be customized to fit the wearer's foot, providing a personalized fit and feel.

[0042] The edges adjacent the toe region (toe and ball of the foot area generally) of the insole can be beveled. This feature allows the insole to better accommodate various types of footwear, including work boots and other types of protective footwear. The beveled edges reduce the overall volume of the insole, allowing it to fit more comfortably within the shoe.

[0043] In some embodiments all or large portions of the thickness of the region of the insole beneath the toes of the foot can be reduced. Again, this feature allows the insole to better fit within shoes with a smaller toe box, such as work boots or other types of protective footwear.

[0044] The bottom surface of the base foam layer can include molded-in structures. These structures can provide more or less cushioning to the foot in various regions, depending on the wearer's needs. This feature allows for a more customized level of comfort and support even with a dense foam cushion that provide heel cupping and arch support.

[0045] The molded-in structures can include ridges and recesses. These features can be strategically placed to provide additional support or cushioning in specific areas of the foot. For example, ridges can be placed in areas that need more support, such as the arch, while recesses can be placed in areas that need more cushioning, such as the heel. An area needing more support would have more space between ridges, for example.

[0046] The present invention also provides a method for creating an insole for an electrostatic discharge footwear. This method involves providing a base foam layer. The foam layer can be created using a variety of materials and methods, depending on the desired properties of the insole.

[0047] The method further involves providing a fabric top cover with conductive threads woven into the cover material. The conductive threads can be woven into the fabric using a variety of techniques, depending on the desired properties of the insole.

[0048] The fabric top cover is then overlaid on the base foam layer. This step creates an electrical flow path from the foot of the wearer to the base foam layer. The overlaying process can be done using a variety of methods, depending on the desired properties of the insole.

[0049] The base foam layer can be constructed of polyurethane closed-cell foam. This type of foam can provide a high level of support and comfort to the wearer. The foam can be molded into a variety of shapes and sizes to fit a wide range of footwear. The density of the foam can be selected to retain supportive shape, especially to the region of the insole rearward of the toe region, such as the arch and heel region.

[0050] The electrostatic discharge chemical additive is added to the base foam layer. This additive is mixed into the liquid polyurethane material before it is molded, foamed, and cured. The additive creates polarity channels within the foam, providing an electrical pathway within the foam layer.

[0051] In some embodiments, the additive can be conductive particles such as carbon powder. These particles can be mixed into the liquid polyurethane material before it is molded, foamed, and cured. The particles polarize to discharge static electricity through the foam layer, further enhancing the insole's electrostatic discharge properties.

[0052] The method can further involve forming the insole into a 3D supportive shape for a foot. This shape can include features such as a heel cup and an arch support, providing increased comfort and foot interface. The 3D shape can be customized to fit the wearer's foot, providing a personalized fit and feel.

[0053] The edges adjacent the toe region of the insole can be beveled as part of the forming process. This feature allows the insole to better accommodate various types of footwear, including work boots and other types of protective footwear. The beveled edges reduce the overall volume of the insole, allowing it to fit more comfortably within the shoe.

[0054] The thickness of the region of the insole beneath the toes of the foot can be reduced as part of the forming process. This feature allows the insole to better fit within shoes with a smaller toe box, such as work boots or other types of protective footwear. The reduced thickness does not compromise the comfort or support provided by the insole. Cushion thickness under the ball of the foot can be maintained, while it can taper forward of the ball of the foot towards the front of the insole where a beveled edge can further reduce thickness.

[0055] The bottom surface of the base foam layer can include molded-in structures that provide relatively more or less cushioning to the foot in various regions of the foot. These structures can be created using a variety of methods, depending on the desired properties of the insole.

[0056] The present invention provides a supportive, comfortable insole that can meet or be well below required maximum levels of resistance to electrostatic discharge. The insole interfaces well with a variety of footwear, making it a versatile solution for a wide range of applications. The insole's unique combination of features, including its conductive threads, foam layer, and molded-in structures, provide a high level of comfort and support while also effectively discharging static electricity.

[0057] Referring now to FIG. 1, it illustrates a footwear insole 100 with electrostatic discharge properties. The insole 100 includes a base 102 and a top cover 106. The base includes a cushion 104. The base may also include support semi-rigid or rigid structures to support the cushion. The insole 100 is designed to provide both comfort and low resistance to electrostatic discharge. The top cover 106 overlays the cushion 104 and provides substantial electrical flow paths from the foot of the wearer to the bottom of the base 102. The base 102 is designed to be comfortable and supportive, with a heel cup 108 and an arch support 110 shaped to the bottom of the wearer's foot. The toe region of the insole 100 includes a beveled edge 114 to better accommodate various types of footwear.

[0058] The cushion layer 104 of the insole 100 as depicted in FIG. 1, can be constructed of various materials, with a preferred material being polyurethane closed-cell foam. This foam is favored due to its comfort and supportive properties. The foam is elastomeric. The durometer of the elastomeric foam is selected to provide the right balance of support and cushion. Preferably, the durometer is approximately 44c, based on the Asker C scale. With the preferred construction, relying on the foam for heel cup and arch support, the range of durometer is between about 41-47c. Higher or lower durometer targets are used on other embodiments depending on the construction, shape, contour, and overall thickness of the insole. Refer further to the discussion below with regard to FIG. 8 where an additional support member might allow the foam to have a lower durometer while still providing good support. Likewise, the density or specific gravity of the polyurethan closed-cell foam is preferably in the range of 0.33+/0.02. Higher or lower densities may be used, again depending on the structure, shape, contour, and overall thickness of the insole product.

[0059] The foam layer of the base 102 is designed to be molded, foamed, and cured with an electrostatic discharge (ESD) chemical additive. This additive creates polarity channels within the foam, providing an electrical pathway for the discharge of static electricity.

[0060] The top cover 106 of the insole 100 as shown in FIG. 1, is constructed with conductive threads woven integrally into the cover material. The threads run throughout the cover material from side to side and front to back, providing ample electrical flow paths from the wearer's foot to the base 102. The top cover 106 is preferably constructed of a breathable knit material, but it may also be a woven or other non-woven material.

[0061] As seen in FIG. 1, the heel cup 108 and the arch support 110 are part of the 3D supportive shape of the insole 100. These features are designed to provide increased comfort and foot interface. The heel cup 108 cradles the heel of the wearer, while the arch support 110 provides support to the arch of the foot. This increased foot interface enhances the ESD capability of the insole 100. Thus, the top cover 106 may be made with a lower amount of conductive material to achieve the antistatic electrical conduction therethrough.

[0062] The beveled edge 114 in the toe region of the insole 100 as illustrated in FIGS. 1, 5, and 6, is designed to better accommodate various types of footwear, particularly work footwear. The protective features of work footwear often create a decreased volume within the toe box. The beveled edge 114 allows the insole 100 to better integrate within the footwear without taking up much volume. The thickness of the region of the insole 100 beneath the toes of the foot (toe region 112) can also be reduced to accommodate such footwear as further detailed below in connection with FIGS. 6A-C.

[0063] Referring to FIG. 2, a cross-sectional view of the insole 100 positioned within a shoe (footwear 200) is depicted, emphasizing the interaction between the insole base 102 and the shoe's midsole 204 and/or outsole 202. The figure provides a detailed view of footwear 200, the insole 100, the midsole 204, and the outsole 202. The footwear 200 includes the insole 100, the midsole 204, and the outsole 202. The insole 100 is positioned within the shoe and rests on the midsole 204 or a last board (shown in FIG. 7).

[0064] The base 102 of the insole is designed to be comfortable and supportive. It is shaped to the bottom of the wearer's foot, providing a heel cup 108 and an arch support 110. This contouring not only enhances comfort but also decreases the insole's resistance to electrostatic discharge due to increased engagement with the wearer's foot. The base 102 of the insole is preferably constructed with a cushion 104 made from a foam material, preferably polyurethane closed-cell foam, which is molded, foamed, and cured with an electrostatic discharge (ESD) chemical additive. This additive creates polarity channels within the foam, providing an electrical pathway. The base 102 may also have a semi-rigid support structure beneath and/or beside at least a portion of the cushion 104 to increase support to cushion 104 and insole 100.

[0065] The midsole 204 is a component of the shoe that lies between the insole 100 and the outsole 202. Often the footwear also includes a last board on top of or in place of the midsole. The midsole 204 provides additional support and cushioning to the wearer's foot. It is typically softer than the outsole 202 while the outsole may be more durable. The insole 100, specifically the base 102 of the insole, interacts with the midsole 204, transmitting the electrical flow from the insole 100 to the midsole 204. This interaction is facilitated by the conductive properties of the insole 100, particularly the conductive threads in the fabric top cover and the ESD chemical additive in the base foam layer. As further explained below, the footwear 200 might also include a Strobel or last board between the insole and the midsole or outsole.

[0066] The outsole 202 is the bottom part of the shoe that comes in direct contact with the ground. The outsole 202 is designed to be durable and provide traction. The insole 100, particularly the base 102 of the insole, also interacts with the outsole 202, transmitting the electrical flow from the insole 100 to the outsole 202 through the last board and midsole, if included in the footwear. This interaction further enhances the shoe's low resistance to electrostatic discharge, making the footwear 200 safe for static-sensitive work zones.

[0067] FIG. 3 illustrates a cross-sectional side-elevational view of the insole 100. The base 102 and top cover 106 are shown. The base 102 includes cushion 104. The upper side of cushion 104 is generally contoured to the shape of the foot. The bottom side of the cushion 104 (or base 102) and has formed recesses 302 and ribs 300 for differential cushioning. The top cover 106 overlays the base 102, providing a smooth surface for the foot of the wearer.

[0068] FIG. 4A presents a top view of the insole with an ESD fabric top cover 106 and contoured heel cup 108 and arch support 110 designed to fit the wearer's foot shape. The ESD fabric top cover 106 overlays a base foam layer (not shown in this figure) and is woven with conductive threads that provide electrical flow paths from the foot of the wearer to the foam layer. The contoured heel cup 108 and arch support 110 are designed to provide both comfort and lower ESD resistance due to more engagement with the wearer's foot.

[0069] FIG. 4B shows the fabric top cover 106 prior to being molded with the cushion 104. Once molded with the cushion 104, the top cover 106 is trimmed, preferably by die cutting the fabric to match the shape of the cushion 104 and as shown in FIG. 4A. The top cover 106 includes a top face 402 and a bottom face 404. Bottom face 404 includes a film 406. Film 406 helps bond cushion 104 to top cover 106 while limiting penetration of the uncured cushion material (polyurethan liquid base) through the fabric of top cover 106. In a preferred embodiment, film 406 is a thin polyurethane film layer applied only to the bottom of top cover 106. It functions as a bonding layer for the cushion polyurethane to adhere to during the foaming and curing process. No additional adhesives are required during the construction of the insole. Such adhesives could compromise the electrostatic discharge properties. The film 406 used has a very low electrical resistance so as to not significantly impact the overall static discharge of the insole. The thickness is preferably about 0.02 mm and can be in the range of 0.10 mm to 0.01 mm.

[0070] Referring now to FIGS. 5 and 6A-C, the bottom of the inventive insole 100 is illustrated. The figures show the various structural features of the insole, including the insole bottom, a beveled toe edge 114, and a tread pattern 500. These features are designed to provide comfort to the wearer and accommodate different types of footwear. As previously noted, the insole 100 features a heel cup 108, arch support 110, beveled toe edges 114. The insole also includes a base cushion structure or tread pattern 500 with ribs 300 and recesses 302. The insole 100 is designed to provide a comfortable orthotic with low resistance to electrostatic discharge.

[0071] The base 102 provides the overall shape and support for the insole 100. As described previously, it is constructed from a foam layer. The ribs 300 and recesses 302 are molded into the bottom surface of the base cushion structure 500. These structures provide varying levels of cushioning to different regions of the foot, allowing for a customized level of comfort and support. For example, variations for heel strike and toe push may be made. The base structure 500 can also provide extra friction between the bottom of the insole 100 and the last board or midsole. This will help hold the insole in place for better foot stability.

[0072] The tread pattern 500 is molded into the bottom surface of the base cushion layer. The tread pattern can include various ridges and recesses that are strategically placed to provide more or less cushioning to different regions of the foot, such as the heel strike and toe push areas. This feature enhances the insole's comfort and support, while also improving its interface with the foot.

[0073] The beveled toe edge 114, shown in these figures, enhances its compatibility with various types of footwear. The beveled edge allows the insole to better fit within the toe box 208 of the shoe 200, especially in work footwear where protective features often decrease the available volume. This design consideration ensures that the insole can provide support and comfort without taking up excessive space.

[0074] FIG. 6B shows a sulcus line 602 between the regions of the insole that correspond to the ball of the foot and the toes of the foot. Preferably, the thickness of the insole rearward (towards the heel) of the sulcus line 602 is approximately 5.0 mm. A slight taper of the bottom surface of the cushion 104 then extends to the toe end of the insole such that the thickness of the insole is approximately 3.1 mm. Thus, the reduction in thickness extends forward from the sulcus line 602 to the toe end of the insole at the beveled edge 114 and a rounded tip 608. the progression of the taper is shown by lines 610. This taper increases the volume within the toe box of the footwear-a place where volume might be reduced from protective toe-cap features of work footwear. However, the cushion thickness in the region of the ball of the foot (to just past where the metatarsal heads press onto the insole) remains significant, promoting foot comfort. The beveled edge 114 is a reduction in addition to the thickness taper.

[0075] FIG. 7 illustrates the interior of a shoe, denoted by reference numeral 200. The shoe 200 includes a last board 700, which is shown with conductive stitching 702. The conductive stitching 702 creates a conductive path from the insole to the midsole 204 or outsole 202. The last board 700 is an integral part of the shoe 200 and serves as the foundation on which the shoe is constructed. It is typically made from a durable material that can withstand the wear and tear of daily use.

[0076] The conductive stitching 702 is woven into the last board 700. The stitching 702 is composed of conductive threads that are designed to provide a path for electrical flow. Since the insole 100 with cushion 104 is layered above the last board 700, the threads sewn through the last board are not felt by the wearer. The density of the electrical threads (conductive stitching 702) through the last board can be provided to achieve the desired conductive flow from the insole 100 to the midsole and or outsole. Other means of providing a conductive last board are also possible.

[0077] The midsole 204 and the outsole 202 are the parts of the shoe 200 that come into direct contact with the ground. The midsole 204 is typically made from a material that can absorb shock and provide cushioning, while the outsole 202 is designed to provide traction and resist wear. The conductive path created by the conductive stitching 702 extends from the insole, through the last board 700, and to the midsole 204 and/or the outsole 202. This allows for the discharge of static electricity, thereby enhancing the ESD capability of the shoe 200.

FIG. 8 shows a further embodiment that includes a support member 800. Support member 800 is more rigid than cushion 104. Support member 800 may be, for example, a plastic material rather than a foam material. Support member 800 cradles cushion 104 to hold it in place and still provide support even with a less dense foam in cushion 104. However, as shown in FIG. 8, at least half of the bottom surface of base 102 exposes cushion 104. Thus, support member 800 does not need to be discharge conductive to provide adequate dissipation of static electricity. Support member 800 preferably surrounds heel cup 108 and underlies at least a portion of arch support 110 of cushion 104.

[0078] The U-shape of support member 800 exposes a central region of cushion 104 beneath heel cup 108. This provides conducive dissipation over a large area and also allows support member 800 to flex inwardly or outwardly to accommodate footwear of various widths. Of course, support member 800 may also include conductive material therein to provide static electricity dissipation.

[0079] The insole designed as per the innovative aspects of the present invention is not just functionally superior, but also excels in providing user comfort. In some embodiments, the insole is formed into a 3D supportive shape for the foot. This shape includes design elements such as a heel cup and an arch support. These features are intended to enhance the comfort of the wearer and to increase foot interface, thereby naturally improving the ESD capability of the insole.

[0080] The present invention also addresses the common issue of footwear compatibility. In certain embodiments of the insole, the edges adjacent to the toe region are beveled. This design element allows the insole to better fit within the toe box of various types of footwear, especially work footwear where the protective features often decrease the available volume. Similarly, the thickness of the region of the insole beneath the ball and toes of the foot can be reduced to accommodate such footwear, ensuring the comfort of the wearer is not compromised.

[0081] The bottom surface of the base cushion layer of the insole may also be tailored to enhance comfort. In certain embodiments, the bottom surface includes molded-in structures that provide relatively more or less cushioning to the foot in the various regions. For example, the structures may take the form of ridges and recesses, strategically placed to create regions that provide more or less cushioning. This allows for a customized level of comfort and support to the wearer, further enhancing the usability of the insole.

[0082] Compared to the prior art solutions, the present invention offers several advantages including its enhanced comfort, improved interface with the foot, and efficient electrostatic discharge. The contoured 3D shape for the foot, the conductive threads in the fabric top layer, and the ESD chemical additive in the base foam layer work synergistically to create an insole that is both comfortable and effective in reducing ESD resistance. Additionally, the beveled edge of the toe region of the cushion layer of the base and the adjustable thickness beneath the ball and toes of the foot better accommodates work footwear, making this insole a versatile solution for all types of footwear.

[0083] The embodiments of the present invention disclosed herein are intended to be illustrative and not limiting. Other embodiments are possible, and modifications may be made to the embodiments without departing from the spirit and scope of the invention. As such, these embodiments are only illustrative of the inventive concepts contained herein. It should be understood that the present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The invention should not be limited to the described and depicted embodiments, but should be defined by the appended claims, which therefore include all equivalents of the disclosed and claimed invention.