Customized footwear and process for manufacturing such footwear

Abstract

An article of footwear for distributing pressure evenly on various regions of the foot comprising an upper and at least one moldable foam piece attached to an inner surface of the upper is provided, together with an article of footwear manufactured by a process comprising attaching at least one moldable foam piece to the inner surface of the upper of the footwear and stretching the upper over a footwear last comprising at least one cavity cut into the surface of the last that accommodates the moldable foam piece.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 60/614,068, filed Sep. 29, 2004.

FIELD OF INVENTION

The present invention relates to footwear. In particular, this invention relates to a design, construction, and process of manufacturing for footwear that better supports and stabilizes the skeletal structure of the feet.

BACKGROUND OF THE INVENTION

Most types of climbing footwear are generally designed to fit very snugly around the toes and heel of the foot. This type of snug design allows efficient transfer of power and energy from the human body to rock or ice surfaces. However, the snug design often forces the toes into a curled or knuckled position. In order to hold the foot in the curled or knuckled position, the footwear must exert pressure onto the top portion of the toes, under the ball of the foot, and the back and upper portions of the heel. Due to the differences in individual foot shapes, the pressure exerted by the footwear on the toes and heel, as well as under the ball of the foot, can be quite uncomfortable and sometimes painful, which can affect a climber's performance.

One type of footwear known in the art is manufactured with a set shape and support, provided with moldable materials. However, the shape and support of this type of footwear cannot be modified and therefore the footwear cannot be formed to the foot. Another type of footwear is manufactured with a thermoplastic structure throughout the upper of the footwear. The thermoplastic structure can be heated and molded to the foot. However, the thermoplastic structure is typically bulky and heavy, and has limited rigidity, and the moldability of the footwear is limited to the upper portion. Yet another type of footwear is provided with a self-contained bladder within the footwear. Different types of materials, such as “gel” or foam pieces, are contained within the bladder. A major limitation of this type of footwear is that the bladder is generally not integrated into the main structure of the footwear via mutual composite linkage or mechanical attachment. Also, the self-contained bladder system can only achieve one set of stiffness after molding, which leaves no customization of desired support. Therefore, the footwear cannot be customized to the feet. Still another type of footwear is provided with bladder systems that can be injected externally with a stiffening agent.

Most types of footwear known in the art are manufactured around a last. Generally, a footwear manufacturing process first involves stretching the upper of the footwear around the last using a considerable amount of tension. For example, in cement lasted footwear designs, the upper is stretched over the last using a lasting machine which applies a high amount of tension to the upper in order to stretch it over the last and to glue the edges of the upper to material on the bottom of the last. During this process, if a moldable foam piece is attached to the inside surface of the footwear upper, the foam becomes and remains compressed, thereby losing its moldable properties.

U.S. patent Publication No. US20040049950 discloses moldable footwear provided with a base and an upper portion. The upper portion contains two bladders located on the medial and lateral side of the foot. The two bladders are placed approximately between the base and malleoli, and between the middle of the heel and the proximal metatarsals. The bladders contain a dry composite. The dry composite is impregnated with a fast setting resin/hardener liquid that is dispensed via a double barrel syringe and spiral cap through a small opening located on the posterior heel.

U.S. patent Publication No. US20050144034 discloses a process for manufacturing injection molded polyurethane footwear consisting of two or more parts with different compositions. The process is directed to simultaneously injecting two different formulas of polyurethane into two different cavities of the same mold. The dual rotating or shuffling sole-plate makes it possible to inject the outsole and the insole/upper/shaft simultaneously without mixing.

U.S. patent Publication No. 20030227105 discloses an article of textile-soled footwear and process of manufacturing the footwear by employing a fabrication process and an apparatus that allows fabrication of the footwear's outer shell via a single injection-molding step. The article of footwear is provided with a textile layer at the ground-contacting surface of the outsole, the textile layer being moldably and integrally attached, in a common mold, to the molded outsole as it is being created during the injection process. Fasteners are set along the side of the sole plate of the injection mold to secure the textile layer across the sole plate, preventing the textile layer from being moved during injection of the moldable compound to form the outsole. The sole plate and the sidewalls of the injection mold are assembled in place for the injection process. The shoe upper is fitted onto the shoe last and set in place in the mold, the mold is closed, and the moldable compound is injected into the mold. Once injection is complete, the mold side walls are opened, the injected shoe is removed, and the excess textile layer is trimmed.

U.S. Pat. No. 6,228,300 and U.S. patent Publication No. 20010004139 both disclose moldable footwear which conforms to the size and shape of the feet, together with a process of forming the footwear. The process in accordance with the above disclosures comprises molding the starting material on and around a foot, wetting the material with a mixture comprising a leather stiffening or hardening agent, and drying the wetted material while still on the foot.

U.S. Pat. No. 4,886,238 discloses a molding apparatus and a process for use in the manufacture of an article of footwear by molding an insole of molten flexible plastic material to a preformed outsole and to an upper.

U.S. Pat. No. 4,535,554 discloses an article of footwear formed of a molded plastic body member, provided with a molded plastic foot support member that supports the wearer's foot, and a flexible harness which retains the body member on the wearer's foot. The body member has a sole portion, a toe cup, a heel cup, and longitudinal sidewalls which extend from the toe cup to the heel cup. The foot support member has an upper surface, located at about the same height as the upper edges of the sidewalls, which provides anatomical support for a wearer's foot. The harness has a horizontal strap and inclined straps. The horizontal strap is connected to the heel cup, and the inclined straps are connected to the sidewalls of the body member.

The various types of footwear and various processes for manufacturing the footwear described above do not adequately provide for even distribution of pressure on various regions of the wearer's foot. In addition, the footwear and the processes described above do not adequately prevent moldable materials that are attached to the upper and the insole of the footwear from being compressed during the process of fitting the upper or insole of the footwear to a footwear last. It is therefore desirable to provide an article of footwear and a process for manufacturing such footwear to overcome the aforementioned disadvantages and problems

SUMMARY OF THE INVENTION

An article of footwear is provided for distributing pressure evenly on the top portion of the toes, the instep region of the foot, the upper ankle region, the back and lower region of the heel, and the region under the ball of the foot.

In one embodiment, the upper of the inventive footwear is provided with at least one moldable foam piece attached to an inner surface of the footwear upper in at least one of an upper toe region, an instep region of the foot, an upper ankle region, and a back and lower region of the heel.

In another embodiment, the insole of the inventive footwear is provided with at least one moldable foam piece attached to an inner surface of the insole in a region under the ball of the foot. As used herein and in the claims, the term “insole” means a flexible layer that is positioned between the wearer's foot and a midsole and/or an outsole of the footwear. The inner surface of the insole faces the midsole and/or outsole and the outsole contacts the ground.

Alternatively, the inventive footwear is provided with a first moldable foam piece attached to an inner surface of the insole in a region under the ball of the foot and a second moldable foam piece attached to an inner surface of the footwear upper in at least one of an upper toe region, an instep region of the foot, an upper ankle region, and a back and lower region of the heel.

The upper of the footwear may be constructed of an inelastic material and the moldable foam is typically a closed-cell expanded foam. The moldable foam piece may be in any desired thickness and density. The moldable foam piece may be in any configuration and is provided with a generally tapered outer edge in a manner such that when the moldable foam piece is attached to the inner surface of the upper or insole, the outer edge of the moldable foam piece forms an obtuse angle with respect to the inner surface of the upper or insole. Thus, the moldable foam piece has a convex configuration, like the surface of a sphere. In addition, the surface contour of the moldable foam piece can be symmetrical or asymmetrical with respect to the perimeter of the moldable foam piece.

In another embodiment, the inventive footwear is provided with at least two pull tabs attached to the Achilles notch area of the upper heel counter of the footwear and positioned on opposing sides of the heel counter.

A process of manufacturing the inventive footwear is also provided. In one embodiment of the inventive process, at least one moldable foam piece is molded into a customized configuration by the application of heat and pressure or pressure alone. After the desired customized configuration is achieved, the at least one moldable foam piece is attached to the inner surface of either the upper or the insole of the inventive footwear.

The upper or the insole, to which the at least one moldable foam piece is attached, is stretched over a specially designed last. The last comprises at least one cavity or depression cut into the surface of the last. The at least one cavity is hollowed-out and basin-like, and has a generally concave and rounded configuration, resembling the inside surface of a sphere. The at least one cavity has a larger surface area than that of the moldable foam piece. This allows the moldable foam piece to remain uncompressed during the manufacturing process when the upper or the insole of the inventive footwear is stretched over the inventive last, thus providing the footwear with curved protrusions on the inside. After the upper is stretched over the inventive last, it is attached or bonded to a rand, a midsole and/or an outsole, using a method known in the art.

When the inventive footwear is worn and tightened by laces, straps, or elastic bands, the moldable foam attached to the inner surface of the upper and/or the insole of the footwear is compressed against regions of the foot that exert the highest pressure against the inner surface of the footwear, and/or against natural depressions in the foot, such as in the upper ankle area, thus creating an inside contour that matches the contour of the wearer's foot. The matching of the shape of the inventive footwear to the wearer's foot not only allows for distribution of pressure, but also relieves various pressure points, resulting in improved comfort for the wearer's feet.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention are described in detail below and illustrated in the drawings, in which:

FIG. 1 shows a top view of an embodiment of the inventive footwear last;

FIG. 2 shows a bottom view of another embodiment of the inventive footwear last;

FIG. 3 shows a side view of yet another embodiment of the inventive footwear last;

FIG. 4 shows a side view of still another embodiment of the inventive footwear last;

FIG. 5 shows a side view of an alternative embodiment of the inventive footwear last;

FIG. 6 shows a top view of another alternative embodiment of the inventive footwear last; and

FIG. 7 shows a perspective view of an embodiment of the inventive footwear provided with two moldable foam pieces as indicated by dotted lines.

DETAILED DESCRIPTION OF THE INVENTION

An article of footwear is provided having improved distribution of pressure on the top region of the toes, over the instep of the foot, on the upper region of the ankle, the back and lower region of the heel, and/or the region under the ball of the foot by custom molding the interior surface of the inventive footwear to the foot. This is accomplished by providing curved projecting volumes, or protrusions, on interior surfaces of the footwear in regions where the foot exerts high pressure against the interior surfaces of the footwear and/or in regions that match natural depressions or cavities in the foot, thereby producing footwear that provides better fit and more even distribution of pressure. More specifically, the protrusions, which are preferably formed of moldable foam pieces, are provided in at least one of the following regions: the upper toe region, the instep region, the upper ankle region, the back and lower region of the heel, and the region around the ball of the foot. The inventive footwear is capable of withstanding wear and tear, and of holding the foot in the optimal position for efficient transfer of power and energy. The present invention may be applied to various forms of footwear including, but not limited to, climbing, athletic, hiking, mountaineering, casual, dress shoes, sandals, slippers, clogs, and the like.

An embodiment of the inventive footwear 20 is shown in FIG. 7. The upper 14 of the footwear 20 is provided with at least one moldable foam piece 30 attached to an inner surface of the footwear upper 14 in an upper toe region 40. In other embodiments, the at least one moldable foam piece 30 may be attached to an instep region 50 of the foot, an upper ankle region 60, a back and lower region of the heel 70, or combinations thereof.

In another embodiment, an insole 80 of inventive footwear 20 is provided with at least one moldable foam piece 30 attached to an inner surface of insole 80 in a region under the ball of the foot. As used herein and in the claims, the term “insole” means a flexible layer that is positioned between the wearer's foot and a midsole and/or an outsole of the footwear. The inner surface of the insole faces the midsole and/or outsole and the outsole contacts the ground.

Alternatively, inventive footwear 20 may be provided with a first moldable foam piece 30 attached to the inner surface of insole 80 in a region under the ball of the foot and at least one additional moldable foam piece 30′ attached to the inner surface of footwear upper 14 in at least one of the upper toe region 40, instep region 50, upper ankle region 60, and back and lower region of the heel 70.

Inventive footwear 20 may be provided with at least two pull tabs 100 attached to an Achilles notch area 120 of an upper heel counter of the footwear 20 and positioned on opposing sides of the heel counter. The pull tabs 100 may also take form of loops.

If upper 14 of footwear 20 is constructed of mostly elastic material, it is difficult to maintain the desired shape of the foot within the footwear 20. Therefore, upper 14 of inventive footwear 20 comprises an inelastic material so that the footwear 20 is capable of holding the foot in the optimal position for efficient transfer of power and energy. Examples of the inelastic material include, but are not limited to, leather, synthetic leather, woven fabrics, and the like.

Moldable foam piece 30 is typically a closed-cell expanded foam, such as ethylene vinyl acetate (EVA), polyurethane, or Pebax® foam. Moldable foam piece 30 may be constructed in any desired thickness and density. In one embodiment, moldable foam piece 30 is between about 6 mm to 10 mm in thickness and has a durometer measurement between about 20 to 40 on a Shore C scale. In areas where the foot is more sensitive to pressure, such as the toes, a lower density foam may be used, for example, 25 on a Shore C scale. A higher density foam may be used in and around the heel area, where the foot is less sensitive to pressure and the forces on the sides of the footwear are greater, and a firmer foam, for example, 35 on a Shore C scale.

Moldable foam piece 30 may be in any configuration and it may generally have an oval or oblong configuration. Moldable foam piece 30 is provided with a generally tapered outer edge 150 in a manner such that when moldable foam piece 30 is attached to the inner surface of upper 14, for example, outer edge 150 of moldable foam piece 30 forms an obtuse angle with respect to the inner surface of upper 14. Thus, moldable foam piece 30 generally has a convex configuration with respect to the inner surface of upper 14 and resembles the surface of a sphere. In addition, the surface contour of moldable foam piece 30 can be symmetrical or asymmetrical with respect to the perimeter of moldable foam piece 30.

A process of manufacturing the inventive footwear is also provided. Most footwear is manufactured around a last. Generally, a footwear manufacturing process first involves the stretching of the upper of the footwear around the last with a considerable amount of tension. In climbing shoes, for example, rubber rands and outsole are then bonded or glued to the upper of the footwear. The rand and outsole bonding process also requires applying considerable pressure and tension to the upper of the footwear. In cement lasted footwear designs, the upper is stretched over the last using a lasting machine which applies a high amount of tension to the upper in order to stretch it over the last and to glue the edges of the upper to material onto the bottom of the last. In addition, heat is sometimes used to help cure the glue. During this process using a conventional last, if a moldable foam piece is attached to the inside surface of the footwear upper, the foam will become compressed and remain compressed, thereby losing its moldable properties.

During the process of manufacturing the inventive footwear, a specially designed last having at least one cavity or depression cut into the surface of the last is employed. The cavity accommodates the moldable foam piece and thereby allows the moldable foam piece to remain uncompressed during the manufacturing process. The upper may thus be lasted, and the rands and the soles bonded to the upper of the footwear using all necessary pressure and heat without compressing the moldable foam piece.

In one embodiment of the inventive process, at least one moldable foam piece 30 may be molded into a customized configuration quickly, if desired, by utilizing heat and pressure. Alternatively, moldable foam piece 30 may be molded into a customized configuration slowly by utilizing pressure alone.

After the desired customized configuration of moldable foam piece 30 is achieved, an untrimmed piece of moldable foam is attached to the liner of upper 14 or insole 80 of the inventive footwear. The liner of footwear 20 and moldable foam piece 30 are generally laminated to each other. In one embodiment, the liner and the untrimmed moldable foam are perforated. The perforations, generally about 3 mm in diameter and approximately 6 mm apart, pass through both the liner layer and the untrimmed moldable foam. The perforated liner and the untrimmed moldable foam are then trimmed, for example, approximately to the shape of upper 14 of footwear 20. The edges of the liner and the trimmed moldable foam are next skived and laminated to upper 14. The liner and the moldable foam are then attached to the bottom front portion and the top edge of the footwear 20, by way of stitching, sewing, bonding, or gluing.

The upper 14 or the insole 80, to which at least one moldable foam piece 30 is attached, is stretched over the specially designed last. An embodiment of the inventive last 10 is shown in FIG. 1. The last 10 comprises at least one cavity 12 or depression cut into the surface of the last 10. The at least one cavity 12 is hollowed-out and basin-like, and has a generally concave and rounded configuration, resembling the inside surface of a sphere. The at least one cavity 12, generally has a larger surface area than that of moldable foam piece 30, allowing moldable foam piece 30 to remain uncompressed during the manufacturing process when the upper 14 or the insole 80 of the inventive footwear 20 is stretched over the inventive last 10.

FIG. 1 shows an embodiment of inventive last 10 provided with two cavities 12 about the upper toe region 40. FIG. 2 shows another embodiment of inventive last 10 provided with a cavity 16 about the region under the ball of the foot 90. FIG. 3 shows yet another embodiment of inventive last 10 provided with cavity 12 about the upper toe region 40 and a cavity 25 about the upper and back heel region 70. FIG. 4 shows still another embodiment of inventive last 10 provided with cavity 12 about the upper toe region 40, cavity 25 about the upper and back heel region 70, and a cavity 16 about the region under the ball of the foot 90. FIG. 5 shows an alternative embodiment of inventive last 10 provided with cavity 12 about the upper toe region 40, cavity 16 about the region under the ball of the foot 90, and a cavity 35 about the upper ankle region 60. FIG. 6 shows another alternative embodiment of inventive last 10 provided with two cavities 45 about the instep region 50.

Inventive footwear 20 may be manufactured by a process comprising stretching upper 14 over last 10 provided with at least one cavity 12 about the upper toe region 40. When upper 14 of the inventive footwear is stretched over last 10, moldable foam piece 30, which is attached to the inside of upper 14, corresponds to and fits within the basin-like cavity 12 of last 10. The concave configuration of cavity 12 allows moldable foam piece 30 to retain a tapered outer edge 150.

Inventive footwear 20 may also be manufactured by a process comprising stretching insole 18 over last 10 provided with at least one cavity 16 cut into the bottom of footwear last 10, about the region around the ball of the foot 90. In this embodiment, moldable foam piece 30 is skived all the way around the perimeter of last 10 and is attached or bonded to insole 18 of footwear last 10. Insole 18 and moldable foam piece 30 are then bonded upper 14 of the inventive footwear 20 wherein moldable foam piece 30 is inserted between insole 18 and upper 14 of footwear 20.

Inventive footwear 20 may yet be manufactured by a process comprising stretching upper 14 over last 10 provided with at least one cavity 25 cut into a back heel area 70 of last 10 in a shape similar to an Achilles pad, centered at the back heel area 70 of footwear last 10. Moldable foam piece 30 is skived all the way around the perimeter of back heel area 70 and is bonded to back heel area 70 of footwear last 10. The Achilles pad shaped cavity 25 is then finished with a finishing material. The finishing material includes, but not limited to, pig skin, a thin and supple synthetic material, and the like.

Inventive footwear 20 may still be manufactured by a process comprising stretching upper 14 over last 10 provided with at least one cavity 35 cut into an upper ankle region 60 of last 10. Moldable foam piece 30 is skived all the way around the perimeter of an upper ankle region 60 and is bonded to upper ankle region 60 of footwear last 10.

Inventive footwear 20 may alternatively be manufactured by a process comprising stretching upper 14 over last 10 provided with at least one cavity 45 cut into an instep region 50 of footwear last 10. Moldable foam piece 30 is skived all the way around the perimeter of instep region 50 of footwear last 10 and is bonded to instep region 50 of footwear last 10.

Further, inventive footwear 20 may be manufactured by a process comprising inventive last 10 provided with at least one cavity 12, cavity 16, and cavity 25 cut into various regions of footwear last 10. In other alternative embodiments, inventive footwear 20 may be manufactured by a process comprising last 10 provided with at least one cavity 12, cavity 16, cavity 25, at least one cavity 35, and at least one cavity 45 cut into various regions of footwear last 10.

The present invention has been described with reference to specific embodiments. These specific embodiments should not be construed as limitations on the scope of the invention, but merely as illustrations of exemplary embodiments. It is further understood that many modifications, additions and substitutions may be made to the described footwear and process of manufacturing such footwear without departing from the broad scope of the present invention.

Claims

1. An article of footwear comprising:

an upper;

an insole; and

at least one moldable foam piece attached to an inner surface of either the upper or the insole,

wherein when a user's foot is inserted in the footwear, the moldable foam piece is positioned in a region where the foot exerts high pressure against an inner surface of the footwear.

2. An article of footwear comprising:

an upper;

an insole; and

at least one moldable foam piece attached to an inner surface of either the upper or the insole,

wherein the moldable foam piece is located in a region selected from the group consisting of: top region of the toes, instep of the foot, upper region of the ankle, back and lower region of the heel, and under the ball of the foot.

3. The article of footwear of claim 2, wherein the upper is constructed of an inelastic material selected from the group consisting of: leather, synthetic leather, woven fabrics, and the like.

4. The article of footwear of claim 2, wherein the moldable foam piece has a thickness between 6 and 10 mm.

5. The article of footwear of claim 2, wherein the moldable foam piece has a density thickness between 20 and 40 on the Shore C scale.

6. The article of footwear of claim 2, wherein the moldable foam piece comprises a generally tapered outer edge in a manner such that when the moldable foam piece is attached to the inner surface of the upper or the insole, an outer edge of the moldable foam piece forms an obtuse angle with respect to the inner surface of the upper or the insole.

7. The article of footwear of claim 2, wherein the moldable foam piece is symmetrical with respect to the perimeter of the moldable foam piece.

8. The article of footwear of claim 2, wherein the moldable foam piece is asymmetrical with respect to the perimeter of the moldable foam piece.

9. The article of footwear of claim 2, wherein the moldable foam piece is a closed-cell expanded foam selected from the group consisting of: ethylene vinyl acetate (EVA), polyurethane, or Pebax® foam.

10. The article of footwear of claim 2, wherein the footwear is provided with at least two pull tabs attached to an Achilles notch area of the footwear.

11. A method of manufacturing an article of footwear comprising:

attaching at least one moldable foam piece to an inner surface of an upper of the footwear;

stretching the upper over a footwear last comprising at least one cavity cut into the surface of the last that accommodates the moldable foam piece; and

skiving the moldable foam piece around the perimeter of the at least one cavity, wherein the moldable foam piece remains uncompressed when the upper of the footwear is stretched over the last.

12. An article of footwear manufactured by the method of claim 11.

13. The method of claim 11 wherein the at least one cavity is cut into a region of the footwear last selected from the group consisting of: an upper toe region, an instep region, an lower ankle region, a back and lower region of the heel, and combinations thereof.

14. An article of footwear manufactured by the method of claim 13.

15. A method of manufacturing an article of footwear comprising:

attaching at least one moldable foam piece to an inner surface of an insole of the footwear;

stretching the insole over a footwear last comprising at least one cavity cut into the surface of the last that accommodates the moldable foam piece; and

skiving the moldable foam piece around the perimeter of the at least one cavity, wherein the moldable foam piece remains uncompressed when the insole of the footwear is stretched over the last.

16. An article of footwear manufactured by the method of claim 15.

17. The method of claim 15, wherein the at least one cavity is cut into of the footwear last about a region under the ball of the foot.

18. An article of footwear manufactured by the method of claim 17.