Footwear comfort componentry

Abstract

The present invention relates to footwear componentry for alleviating the discomfort caused by wearing high-heeled footwear.

Description

BACKGROUND OF THE INVENTION

High heel footwear makes a fashion statement. However, there is an inherent discomfort in wearing said footwear. As many as 20% of the wearers of such footwear immediately experience foot pain related to the shoes, and the majority of wearers experience such pain after as little as four hours of wear. This discomfort results primarily from the wearer's foot sliding forward in the shoe with the consequence that the wearer's toes are jammed in the toe portion of the shoe. Specifically, by raising the heel higher than that of the natural foot angle, the wearer's natural walking pattern is altered, resulting in higher impulsive loads on the musculoskeletal system. In an investigation utilizing small low-mass piezoelectric accelerometers attached to the skin surface of both tibial tuberosities, the heel and metatarsal strike acceleration values began to exceed the barefoot values in the heel height ranges of 1.75 to 2.25 inches. Notwithstanding the inherent discomfort associated with high heel footwear, many women choose to wear such footwear in order to enhance the apparent length and slenderness of their legs. Further, men can experience the same discomfort while wearing elevated heel footwear, such as work boots and Western-style boots.

The art has attempted to develop componentry to manage the problem of discomfort while maintaining the desired stylishness that higher heels convey. For example, U.S. Pat. No. 4,876,805 discloses a flexible, energy absorbing insole for high heel footwear comprising an open cell, microcellular, flexible polyurethane foam having an energy absorbing polymer in the heel region of said insole. U.S. Pat. No. 4,835,884 discloses a shank containing high heel shoe structure having a heel pad and a basket for receiving said pad.

Further, U.S. Pat. No. 6,519,874 teaches a footwear assembly having an insole with cushioning that aligns with a footbed having a cavity in the rear portion. However, previous componentry failed to take into consideration the influence of gait mechanics as it relates to heel strike, mid-foot loading, metatarsal strike and toe off. It is well accepted that, as the heel is inclined, the foot's natural mechanism for shock absorbing and structural support are compromised, thus creating great discomfort.

Now, the Applicant has solved the problems that the previous componentry failed to solve. Applicant's componentry, when used in the assembly of high heel shoes, effectively lowers the internal heel height without compromising the external heel height, thereby, bringing the foot's mechanics closer to a naturally gaited foot. The integration of Applicant's footwear components into a variety of heel heights, ranging from as low as ¾ inch to as high as 3 inches, provides a reduction in actual heel height ranging from 5% to 55%. It is an accepted phenomenon that, as the heel is elevated; the forces are transferred from heel strike to a phenomenon known as metatarsal strike, as foot pressures are re-proportioned across the plantar surface of the foot. These forces that enter the body during the metatarsal strike are reduced by 10% to 50% when the Applicant's componentry is incorporated into footwear. Hence, the discomfort associated with wearing higher heel heights is reduced, while maintaining the desired stylishness. When Applicant's componentry is used in footwear, said footwear is both comfortable and aesthetically pleasing at the point of purchase display and on the foot of the wearer. Further, said componentry eliminates the need for a metal shank or other inserted stiffener, while providing the desired flexibility and stability to the wearer.

SUMMARY OF THE INVENTION

The present invention relates to a footbed comprising a protuberance in the subcalcaneous region of said footbed wherein further, the anterior portion of said protuberance is larger relative to the posterior portion of said protuberance.

The present invention further relates to an insole comprising:

• • a. a posterior rigid foam % component, having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and
  • b. a flexible metatarsal region.

The present invention also relates to a bi-layer footwear component comprising:

• • a. a first layer, wherein said first layer is comprised of a footbed comprising a protuberance in the subcalcaneous region of said footbed, wherein further, the anterior portion of said protuberance is larger relative to the posterior portion of said protuberance; and
  • b. a second layer, wherein said second layer is comprised of an insole comprising:
    • 1) a posterior rigid foam ¾ component having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and
    • 2) a flexible metatarsal region.

The following terms have the following meanings herein:

The term “subcalcaneous region” means the region below the heel.

The term “anterior portion” as used herein means the larger portion of said subcalcaneous protuberance.

The term “posterior portion” as used herein means the smaller portion of said subcalcaneous protuberance.

The term “larger,” as used herein is a relative term indicating that the anterior portion of said subcalcaneous protuberance and the posterior portion of said subcalcaneous protuberance can never be equal in size. Upon visual examination of said subcalcaneous protuberance, one ordinarily skilled in the art will observe that the anterior portion is larger relative to the posterior portion of said subcalcaneous protuberance. Further, the size relationship between the anterior portion of said subcalcaneous protuberance and the posterior portion of said subcalcaneous protuberance may be quantified by determining protrusion volumes. To quantify the difference in the volume of the anterior and posterior regions of the subcalcaneous protuberance, the following procedure was followed: A casting of the protuberance was made using a rigid elastomer of known, calculated density. The weight of the casting was measured and recorded. The length of the midline longitudinal axis (posterior to anterior) of the casting was measured and recorded. A portion, less than half based on the length of the longitudinal axis, was removed from the posterior portion of the protuberance perpendicular to the longitudinal axis. The posterior of the remaining portion of the protuberance was sanded perpendicular to the longitudinal axis until its length, posterior to anterior, was half of the original longitudinal axis length. The weight of the anterior half of the protuberance casting was measured and recorded. The weight of the posterior half of the protuberance casting was calculated from the initial weight of the casting and the weight of the anterior half of the casting (W_p=W_i−W_a). The volume of the anterior and posterior portions of the casting were calculated using the known density of the casting material and the weights of the anterior and posterior portions of the casting, respectively (V_a=W_a/D, V_p=W_p/D, D=density of casting material). The percent difference between the volume of the posterior and anterior portions of the protuberance was calculated as a percentage of the volume of the posterior portion of the protuberance (((V_p−V_a)/V_a)×100).

In an embodiment of the invention, the % difference between the volume of the anterior portion of the subcalcaneous protuberance and the volume of the posterior portion of the subcalcaneous protuberance is 5%.

In another embodiment of the invention, the % difference between the volume of the anterior portion of the subcalcaneous protuberance and the volume of the posterior portion of the subcalcaneous protuberance is 8.9%

In yet another embodiment of the invention, the % difference between the volume of the anterior portion of the subcalcaneous protuberance and the volume of the posterior portion of the subcalcaneous protuberance is 12%.

The term “metatarsal region” means the forefoot region. The terms “metatarsal” and “forefoot” can be used interchangeably herein.

The term “medial arch” means the arch from the medial point to the midpoint of the foot. The term “longitudinal arch” means the anterior to posterior length of the natural arch.

The term “plantar surface” means the bottom of the foot.

The term “Shore Scale” as used herein means a materials' hardness scale commonly used to measure the surface hardness or resistance to indention of plastics or rubbers. The hardness is measured using equipment called durometers. Durometers vary in the range of hardnesses they can measure by the difference in their spring force and indenter geometry.

The term “pphp” as used here in means parts per hundred polyol.

The term “footbed,” as used herein means the footwear component of the present invention having the subcalcaneous protuberance that the wearer's foot rests on, whose top view is visible to the wearer.

The term “insole,” as used herein, means the footwear component of the present invention having the subcalcaneous depression, said depression also known as a bucket, which is not visible to the wearer.

The term “bi-layer footwear component,” as used herein, means the component formed by the combining of the footbed to the insole, wherein said footbed is placed on top of said insole.

The term “last,” as used herein, means the form over which a shoe is made, which determines the size, shape, contours and style features of the shoe.

DESCRIPTION OF THE DRAWINGS OF THE INVENTION

FIG. 1 illustrates a top view of the footbed of the present invention comprising the subcalcaneous protuberance.

FIG. 1a illustrates a bottom view of the footbed of the present invention comprising the subcalcaneous protuberance.

FIG. 1b illustrates a side view of the footbed of the present invention comprising the subcalcaneous protuberance.

FIG. 2 illustrates a bottom view of the insole of the present invention comprising the subcalcaneous depression.

FIG. 2a illustrates a top view of the insole of the present invention comprising the subcalcaneous depression.

FIG. 2b illustrates a side view of the insole of the present invention comprising the subcalcaneous depression.

FIG. 2c illustrates a rear view of the insole of the present invention comprising the subcalcaneous depression.

FIG. 2d illustrates a cross-sectional view taken across lines 2d-2d of FIG. 2a of the insole of the present invention.

FIGS. 3a and 3b illustrate how the footbed with the subcalcaneous protuberance can be fastened to the insole with the subcalcaneous depression to prepare a bi-layer footwear component.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a footbed comprising a protuberance in the subcalcaneous region of said footbed wherein further, the anterior portion of said protuberance is larger than the posterior portion of said protuberance.

The present invention further relates to an insole comprising:

• • a. a posterior rigid foam ¾ component having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and
  • b. a flexible metatarsal region.

The present invention also relates to a bi-layer footwear component comprising:

• • a. a first layer, wherein said first layer is comprised of a footbed comprising a protuberance in the subcalcaneous region of said footbed, wherein further, the anterior portion of said protuberance is larger relative to the posterior portion of said protuberance; and
  • b. a second layer, wherein said second layer is comprised of an insole comprising:
    • 1) a posterior rigid foam ¾ component having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and
    • 2) a flexible metatarsal region.

The footwear componentry of the present invention, as illustrated herein, can be prepared from materials including, but not limited to, polyurethanes; polycarbonates; polyethyleneterphthlate(PET); polyesters; polyamides; polyalkenes; neoprenes; acrylonitrile/butadiene/sytyrene (ABS); styrene/butadiene; polyvinylchloride; synthetic and natural latex rubbers; ethylene vinyl acetate; polyacrylates, polymethylmethacrylates; silicone elastomers; and polystyrene

In an embodiment of the present invention, polyurethane chemistry is used in the manufacture of the present invention. The basics of polyurethane chemistry are known to those skilled in the art. The basic reaction for making polyurethanes involves mixing an isocyanate with a polyol in the presence of ingredients including, but not limited to, catalysts, antifoamers, absorbents, chain extenders and pigments.

Isocyanates useful in the practice of the present invention include, but are not limited to Polycarbodiimide-modified diphenylmethane diisocyanate (e.g. ISONATE 143L); Carbodiimide Modified MDI (e.g. LURPRANATE MM103); Benzene, 1,1′-Methylene bis-(4-isocyanato-homopolymer (e.g. MONDUR CD); 4,4′-MDI Homopolymer (e.g. RUBINATE 1680); and prepolymer modified polyisocyanate (e.g. RUBINATE 9100, RUBINATE 1920).

Polyols useful in the practice of the present invention include, but are not limited to, polypropylene glycol diols (e.g. ARCOL PPG-1025, PLURACOL P1010, CARPOL PGP1000, Poly-G 20-112); EO-capped polyoxypropylene triols (e.g. MULTRANOL 3901, PLURACOL 380, PLURACOL 220, CARPOL GP6515, Poly-G 85-28, CARPOL GP1535); polyoxypropylene triols (e.g. PLURACOL TP440, MULTRANOL 4012, Poly-G 30-400T, ARCOL E-900, PLURACOL 1198, and Poly-G 92-27); EO-capped polyoxypropylene diols (e.g. MULTRANDOL 9111, PLURACOL 1062, CARPOL PGP4025).

Catalysts useful in the practice of the present invention include, but are not limited to, Triethylenediamine-based catalysts (e.g. DABCO 33LV, DABCO 1027, DABCO 1028, NIAX A-33, JEFFCAT TD-33A, TOYOCAT TEDA-L33, and TEGOAMIN 33); Bis(2-dimethylaminoethyl)ether-based catalysts (e.g. DABCO BL-17, NIAX A-107, JEFFCAT ZF-54, TOYOCAT ETF), 1,8-Diazabicyclo-5,4,0-undecene-7 catalysts (POLYCAT SA-1, PC CAT DBU TA1) and organotin catalysts (e.g. FOMREZ UL-1 and DABCO 120).

Antifoamers useful in the practice of the present invention include, but are not limited to, dimethyl polysiloxanes (e.g. TA-100 and DOW CORNING ANTIFOAM 1500).

Absorbents useful in the practice of the present invention include, but are not limited to, powdered alkali metal alumino-silcates (e.g. MOLSIV ABSORBENT TYPE 4A, SILIPORITE NK 10 AP, Sigma-Aldrich M2135, and SYLOSIV A4).

Chain extenders useful in the practice of the present invention include, but are not limited to, ethylene glycol; 1,4 Butanediol and N,N′-dialkylaminodiphenylmethane (e.g. UNILINK 4200).

Colorants useful in the practice of the present invention include, but are not limited to, pigment dispersions, and reactive dyes.

In an embodiment of the present invention, as illustrated by FIGS. 1, 1a, and 1b, the footbed is composed of a soft (50-60 Shore 00 scale as measured by ASTM D2240) visco-elastic polyurethane elastomer subcalcaneous region and a soft (45-55 Shore 00 scale as measured per ASTM D2240) PU foam. Said soft polyurethane visco-elastic subcalcaneous region is produced by mixing a carbodiimide modified polyisocyanate (ISONATE 143L) with a polyol resin blend. Said polyol resin blend is prepared by blending the following ingredients:

• • 1. 55 pphp (parts per 100 polyol) 1000 molecular weight polypropylene glycol diol (ARCOL PPG-1025).
  • 2. 25 pphp 6000 molecular weight polyoxypropylene triol, with ethylene oxide capping (MULTRANOL 3901).
  • 3. 20 pphp 400 molecular weight polyoxypropylene triol (PLURACOL TP440).
  • 4. 0.50 pphp tertiary amine catalyst, 33% triethylene diamine in dipropylene glycol (DABCO 33LV).
  • 5. 0.05 pphp dialkyltin mercaptide catalyst (FOMREZ UL-1).
  • 6. 0.10 pphp dimethyl polysiloxane antifoaming agent (TA-100).
  • 7. 2.0 pphp alkali metal alumino-silicate 4 absorbent 10 μm powder (MOLSIV ABSORBENT TYPE 4A).
  • 8. A colorant: pigment dispersion, reactive dye, or combination thereof.

Said polyisocyanate is blended with the polyol resin blend, prepared as described hereinabove, at a ratio of 24 to 37 parts isocyanate to 100 parts polyol resin blend. Mixing-induced nucleation is removed by vacuum prior to complete polymerization.

Said soft PU foam is produced by mixing a carbodiimide modified polyisocyanate (ISONATE 143L) with a PU foam polyol resin blend. Said polyol resin blend is prepared by blending the following ingredients:

• • 1. 70 pphp 6000 molecular weight polyoxypropylene triol, with ethylene oxide capping (MULTRANOL 3901).
  • 2. 30 pphp 6600 molecular weight polyoxypropylene triol, with ethylene oxide capping, and a styrene/acrylonitrile copolymer (ARCOL E-900
  • 3. 1.2 pphp Water
  • 4. 0.40 pphp tertiary amine catalyst, 33% triethylene diamine in dipropylene glycol (DABCO 33LV).
  • 5. 0.01 pphp dialkyltin mercaptide catalyst (FOMREZ UL-1).
  • 6. 0.16 pphp diethanolamine
  • 7. A colorant: pigment dispersion, reactive dye, or combination thereof.

Said polyisocyanate is blended with the PU foam polyol resin blend at a ratio of 20 to 25 parts isocyanate to 100 parts polyol resin blend.

The procedure for producing the footbed, as illustrated in FIGS. 1, 1a and 1b, is as follows:

• • 1. Pre-mix both the elastomeric and the foam resin blends.
  • 2. Heat the mold to 125-135 F. and treat the bottom cavity with the appropriate mold release.
  • 3. Insert a piece of U073 plastic-backed PU film into a fabric frame with the PU film side down.
  • 4. Mix the PU elastomer resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 5. Degas the mixture for 20-30 seconds at 25 in Hg.
  • 6. Pour specified amount of degassed mixture into heel cavities.
  • 7. Allow elastomer to cure to tack.
  • 8. Mix the PU foam resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 9. Pour the specified amount of foam mixture into the footbed cavities, spreading the material length-wise, heel to toe, in the center of the cavity.
  • 10. Place the framed PU film on the bottom cavity, PU film side down.
  • 11. Place mold lid on top of PU film/bottom cavity and clamp.
  • 12. De-mold in 5-10 min.

In an embodiment of the present invention, as illustrated by FIGS. 2, 2a, 2b, 2c and 2d, the insole is composed of a flexible microcellular PU foam metatarsal component of varying density (0.28-0.60 g/cc) and hardness (10-60 Shore A scale as measured by ASTM D2240) that is bonded to a hard (75 Shore D scale as measured by ASTM D2240), dense (1.00 g/cc), rigid microcellular PU foam three-quarter component in the posterior region of said insole.

In an embodiment of the present invention, the lower density (0.28 g/cc), soft (10 Shore A), flexible metatarsal component is produced by mixing a carbodiimide modified polyisocyanate (ISONATE 143L) with a polyol resin blend at a ratio of 20 to 25 parts isocyanate to 100 parts polyol resin blend. Said polyol resin blend is prepared by blending the following ingredients:

• • 1. 70 pphp 6000 molecular weight polyoxypropylene triol, with ethylene oxide capping (MULTRANOL 3901).
  • 2. 30 pphp 6600 molecular weight polyoxypropylene triol, with ethylene oxide capping, and a styrene/acrylonitrile copolymer (ARCOL E-900
  • 3. 1.2 pphp Water
  • 4. 0.40 pphp tertiary amine catalyst, 33% triethylene diamine in dipropylene glycol (DABCO 33LV).
  • 5. 0.01 pphp dialkyltin mercaptide catalyst (FOMREZ UL-1).
  • 6. 0.16 pphp diethanolamine
  • 7. A colorant: pigment dispersion, reactive dye, or combination thereof.

The procedure for producing the flexible forefoot component, as illustrated in FIGS. 2, 2a, and 2b, is as follows:

• • 1. Premix the polyol resin blend for the forefoot foam.
  • 2. Heat the mold to 125-135 F. and treat the bottom cavity and the lid with the appropriate mold release.
  • 3. Mix the forefoot foam polyol resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 4. Pour the specified amount of foam mixture into the Forefoot cavities.
  • 5. Place mold lid on top of the bottom cavity and clamp.
  • 6. De-mold in 5-10 min.
  • 7. Trim or die cut the Forefoot component for use with the rigid three-quarter component.

In another embodiment of the present invention, a higher density (0.60 g/cc), firm (60 Shore A), flexible metatarsal component is prepared by molding a mixture of a prepolymer modified polyisocyanate (Rubinate 9100) with a polyol resin blend at a ratio of 60 to 74 parts isocyanate to 100 parts polyol resin blend. Said polyol resin blend is prepared by blending the following ingredients:

• • 1. 75 pphp 4000 molecular weight polyoxpropylene diol, with ethylene oxide capping (MULTRANOL 9111).
  • 2. 25 pphp 6000 molecular weight polyoxypropylene triol, with ethylene oxide capping (MULTRANOL 3901).
  • 3. 8.9 pphp chain extender (ETHYLENE GLYCOL).
  • 4. 4.9 pphp aromatic diamine chain extended (UNILINK 4200).
  • 5. 0.47 pphp tertiary amine gelation catalyst, triethylene diamine in dipropylene glycol (DABCO 33LV).
  • 6. 0.11 pphp tertiary amine delayed-action blowing catalyst, bis (dimethylaminoethyl) ether in dipropylene glycol (DABCO BL-17).
  • 7. 0.71 pphp Water.
  • 8. A colorant: pigment dispersion, reactive dye or combination.

The procedure for producing the flexible forefoot component, as illustrated in FIGS. 2, 2a, and 2b, is as follows:

• • 1. Premix the polyol resin blend for the forefoot foam.
  • 2. Heat the mold to 125-135 F. and treat the bottom cavity and the lid with the appropriate mold release.
  • 3. Mix the forefoot foam resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 4. Pour the specified amount of foam mixture into the forefoot cavities.
  • 5. Place mold lid on top of the bottom cavity and clamp.
  • 6. De-mold in 5-10 min.
  • 7. Trim or die cut the forefoot component for use with the rigid three-quarter component.

In an embodiment of the present invention, the posterior rigid, three-quarter component of the insole, as illustrated by FIGS. 2, 2a, and 2b, is produced by molding a mixture of modified polyisocyanate (RUBINATE 1920) and a polyol resin blend at a ratio of 102 to 114 parts isocyanate to 100 parts polyol resin blend. Said polyol resin blend is prepared by blending the following ingredients:

• • 1. 100 pphp 1500 molecular weight polyoxyproprylene triol, with ethylene oxide capping (CARPOL GPI535).
  • 2. 21 pphp chain extender (ETHYLENE GLYCOL).
  • 3. 5.9 pphp aromatic diamine chain extender (Unilink 4200).
  • 4. 0.92 pphp delayed-action, amine gelation catalyst (DABCO).
  • 5. 0.26 pphp dimethyl polysiloxane antifoaming agent (TA-100)
  • 6. A colorant: pigment dispersion, reactive dye or combination thereof.
  • 7. The percentage of water in the polyol resin blend is measured and adjusted to 0.15-0.20%.

The procedure for producing the rigid, three-quarter, posterior, insole component with said polyol resin blend, as illustrated in FIGS. 2, 2a, and 2b, is as follows:

• • 1. Premix the polyol resin blend for the rigid foam.
  • 2. Heat the mold to 125-135 F. and treat the bottom cavity and the lid with the appropriate mold release.
  • 3. Mix the polyol resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 4. Pour the specified amount of rigid foam mixture into the mold cavities.
  • 5. Place mold lid on top of the bottom cavity and clamp.
  • 6. Open mold in 5-10 minutes.
  • 7. De-mold the part 1-5 minutes after mold opening.

In another embodiment of the present invention, the posterior rigid, three-quarter component of the insole, as illustrated by FIGS. 2, 2a, and 2b, is produced by molding a mixture of modified polyisocyanate (RUBINATE 1920) and a polyol resin blend at a ratio of 103 to 110 parts isocyanate to 100 parts polyol resin blend. Said polyol resin blend is prepared by blending the following ingredients:

• • 1. 100 pphp 400 molecular weight polyoxyproprylene triol (MULTRANOL 4012).
  • 2. 0.40 pphp delayed-action, amine gelation catalyst (POLYCAT SA-1).
  • 3. 0.04 pphp dialkyltin mercaptide catalyst (FOMREZ UL-1).
  • 4. 0.26 pphp dimethyl polysiloxane antifoaming agent (TA-100)
  • 5. A colorant: pigment dispersion, reactive dye or combination thereof.
  • 6. The percentage of water in the polyol resin blend is measured and adjusted to 0.15-0.20%.

The procedure for producing the rigid, three-quarter, posterior, insole component with said polyol resin blend, as illustrated in FIGS. 2, 2a, and 2b, is as follows:

• • 1. Premix the polyol resin blend for the rigid foam.
  • 2. Heat the mold to 165-175 F. and treat the bottom cavity and the lid with the appropriate mold release.
  • 3. Mix the PU rigid foam polyol resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 4. Pour the specified amount of rigid foam mixture into the mold cavities.
  • 5. Place mold lid on top of the bottom cavity and clamp.
  • 6. Open mold in 5-10 minutes.
  • 7. De-mold the part 1-5 minutes after mold opening.

In an embodiment of the present invention, as illustrated by FIGS. 2, 2a, and 2b, the flexible forefoot component and the rigid posterior component may be attached by using an appropriate adhesive.

In another embodiment of the present invention, as illustrated by FIGS. 2, 2a, and 2b, the flexible forefoot component and the rigid posterior component may be attached by molding the rigid posterior component directly to the pre-molded and trimmed flexible forefoot component using the following procedure:

• • 1. Premix the polyol resin blend for the rigid foam.
  • 2. Heat the mold to 125-135 F. or 165-175 F. depending on the rigid foam polyol resin blend being used, and treat the bottom cavity and the lid with the appropriate mold release.
  • 3. Insert the flexible forefoot piece into the mold in the proper orientation. (The core cell structure of the forefoot component, exposed by trimming or die cutting, allows the flexible and rigid components to bond.)
  • 4. Mix the rigid foam resin blend and the corresponding isocyanate at the specified ratio for 10 seconds.
  • 5. Pour the specified amount of rigid foam mixture into the heel and arch areas of the mold cavities.
  • 6. Place mold lid on top of the bottom cavity and clamp.
  • 7. Open mold in 5-10 minutes.
  • 8. De-mold the part 1-5 minutes after mold opening.

FIGS. 1, 1a and 1b illustrate an embodiment of the footbed (3) of the present invention comprising the protuberance in the subcalcaneous region (10). FIG. 1 is a top view of said footbed (3), illustrating the soft polyurethane foam portion (9) of said footbed (3), which spans the entire length of the top view of said footbed (3). FIG. 1a is a bottom view of said footbed (3), illustrating the protuberance in the subcalcaneous region (10) and the soft polyurethane foam portion (9), of said footbed (3). Said protuberance in the subcalcaneous region (10) is affixed to the soft polyurethane foam portion (9) of said footbed (3). The anterior portion (11) of said protuberance (10) is larger relative to the posterior portion (12) of said protuberance in the subcalcaneous region (10). FIG. 1b is a side view of said footbed (3) illustrating the soft polyurethane foam portion (9) of said footbed (3) and the protuberance in the subcalcaneous region (10). Said protuberance has an anterior portion (11) that is larger relative to the posterior portion (12).

FIGS. 2, 2a, 2b, 2c and 2d illustrate an embodiment of the insole (13) of the present invention comprising the subcalcaneous depression (4). FIG. 2 is a bottom view of said insole (13), illustrating the subcalcaneous depression (4) in the posterior rigid foam ¾ component (5) of said insole (13) and the flexible metatarsal component (6) and an optional metatarsal cushion (14). Said posterior rigid foam % component (5) is combined to the flexible metatarsal component (6) to create the insole (13). FIG. 2a is a top view of said insole (13), illustrating the posterior rigid foam % component (5) of said insole and the flexible metatarsal component (6) and an optional metatarsal cushion (14). FIG. 2b is a side view of said insole (13), illustrating the longitudinal arch (7) of said insole (13). FIG. 2c is a rear view of said insole (13), illustrating the subcalcaneous depression (4). FIG. 2d is a cross-sectional view taken across lines 2d-2d of FIG. 2a to illustrate the medial arch (8) of said insole (13).

One skilled in the art of footwear manufacturing understands the need for comfort as well as style. Footwear with eye appealing contours is a goal of footwear manufacturers. Applicant's componentry, which is comprised of the insole and the footbed, is adaptable to the contours of a wide variety of stylish footwear. Said componentry provides comfort without adding excess bulk to the footwear's silhouette. For example, in an embodiment of the invention, the footbed is a cushioned device that extends from the rearward heel point to the most forward point of the flexible metatarsal region. Said footbed has a central positioned protuberance in the subcalcaneous region of said footbed. Said protuberance is a visco-elastic polyurethane elastomer. Said protuberance has a greater proportion of material forward of its mid-point. Said visco-elastic polyurethane elastomer protuberance in the subcalcaneous region is attached to a soft polyurethane foam. Said soft polyurethane foam is visible as the top surface of the entire footbed. Said footbed is fully tapered around its perimeter edges and exhibits a side-to-side taper from the center line to the perimeter edges to promote maximum cushioning and a refined tailored silhouette to the finished constructed footwear. The top surface of the footbed is bonded directly to a polyurethane film that may have a multitude of layers. The purpose of said film is to provide a clean bonding surface capable of receiving colorants, fabrics, hides or combinations thereof. Said footwear may also feature a molded arch and heel counter and any variety of surface ornamentations. The material characteristics of the foot bed are such that a lining material, a textile synthetic or natural hide, can be attached by of methods, including but not limited to cementing and stitching. Both the top and bottom surfaces of the foot bed may include functional or decorative elements or both.

In an embodiment of the invention, the insole is comprised of a posterior rigid foam ¾ component and a flexible metatarsal region. Said posterior rigid foam % component is free formed or cast to fit the exact profile dimensions of the manufacturer's footwear designing contoured last. The contours of the posterior rigid foam % component reflect a lower profile along the lateral side of said rigid foam % component and a higher profile along the medial side of said rigid foam % component. The top of said posterior rigid foam % component is tapered to blend into the contoured surfaces of the manufacturer's foot-forming last. The forward edge of the rigid posterior foam % component exhibits a side-to-side tapered dimension from the center line and perimeter edges, which is symmetrical to the leading edge of the flexible front piece, which also exhibits a side-to-side tapered dimension from the center line to the perimeter edges.

Said posterior rigid foam ¾ component is resistant to flexing, while providing stability to the wearer. Further, these properties are achieved without the use of any metal shank or other inserted stiffener. The posterior rigid foam % component part is designed to compliment the aesthetics of the fully assembled shoe, while providing the requisite stability without the need for a shank.

Said posterior rigid foam ¾ component is stepped tapered along its forward edge. Further, said posterior rigid foam ¾ component is contoured along its forward edge. The forward medial point of said forward edge extends behind the first metatarsal and the forward lateral point of said forward edge extends behind the fifth metatarsal.

The contours of the posterior rigid foam % component add comfort to the assembled footwear because said contours follow the normal, human gaiting patterns. Further, said posterior rigid foam % component has a depression in the subcalcaneous region which promotes proper fit within the heel seat of the assembled footwear, as well as providing the wearer with the desired stability. Said posterior rigid foam % component has a molded and integrated arch to provide support along the longitudinal and transverse arches of the human foot. Said arch has a generally channel-shaped cross section. Said posterior rigid foam % component, which includes the depression in the subcalcaneous region, has one or more negative recesses along its top surface and, one or more positive protuberances along its bottom surface for the purpose of attaching said posterior rigid foam % component to the heel units. Attachment to the heel units is accomplished by means including, but not limited to screws, nails, tacks or rivets. Because the posterior rigid foam % component does not require the addition of a metal shank or other inserted stiffener, the connection of said posterior rigid foam ¾ component to the outside heel is a direct connection.

Said posterior rigid foam ¾ component is combined with said flexible metatarsal region to form Applicant's insole. The flexible metatarsal region is sufficiently elastic so as to follow the contours of the shoe forming contoured last and to easily flex without the use of additional flex grooves. The flexible metatarsal region can be shaped to match any variety of toe characteristics by methods including, but not limited to, trimming, cutting, sanding or skiving. The leading edge of said flexible metatarsal region is tapered and contoured to promote a connection to the posterior rigid foam % component that is comfortable to the wearer. The material characteristics of this flexible metatarsal region are such that a textile substrate can be attached. In a further embodiment, a multiple density flexible metatarsal region can be constructed wherein the material characteristics of said flexible metatarsal region are such that a second density polymer can be added to further attenuate shock generated by metatarsal strike.

In an embodiment of the present invention, the posterior rigid foam ¾ component has a pronounced and stepped taper to allow for a seamless connection to said flexible metatarsal region. This stepped tapered point of connection is also contoured in a sloping fashion, medial to lateral or side-to-side, to promote a comfortable transition from the posterior rigid foam % component to the flexible metatarsal region. Said flexible metatarsal region can be combined with the posterior rigid foam % component by mechanical or chemical means to construct the Applicant's insole.

Either the footbed, as illustrated by FIGS. 1, 1a, and 1b, or the insole, as illustrated by FIGS. 2, 2a, 2b, 2c and 2d, can be used alone as a component in the manufacture of footwear.

Further, the footbed, as illustrated by FIGS. 1, 1a, and 1b, and the insole as illustrated by FIGS. 2, 2a, 2b, 2c and 2d can be used together to form a bi-layer footwear component for use in the manufacture of footwear. When said footbed and insole are used together, the top view of the footbed with the protuberance in the subcalcaneous region, as illustrated by FIGS. 1, 1a, and 1b will be visible to the wearer. In an embodiment of the invention, the protuberance in the subcalcaneous region (10) of the footbed (3), will fit into the subcalcaneous depression (4) of the insole (13), as illustrated in FIGS. 3a and 3b to form a bi-layer footwear component, suitable for use in high-heel footwear. Said footbed and insole can be incorporated into footwear by methods known to those skilled in the art of shoe manufacturing.

The application of Norman Dean, entitled FOOTWEAR HAVING A HEEL AND HEEL BREAST, filed simultaneously herewith is incorporated by reference.

Claims

1. A footbed comprising a protuberance in the subcalcaneous region of said footbed, wherein further, the anterior portion of said protuberance is larger, relative to the posterior portion of said protuberance.

2. A footbed according to claim 1, wherein further, said footbed is prepared from polyurethane materials.

3. A footbed according to claim 2, wherein the top surface of said footbed is bonded to a polyurethane film, said film, capable of receiving colorants, fabrics or hides, or mixtures thereof.

4. A footbed according to claim 2, wherein said footbed comprises a top surface of soft polyurethane foam, further provided that said protuberance in the subcalcaneous region of said footbed is a visco-elastic polyurethane elastomer.

5. An insole comprising:

a. a posterior rigid foam ¾ component having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and

b. a flexible metatarsal region.

6. An insole according to claim 5, wherein further said posterior rigid foam ¾ component comprises a stepped taper along the forward edge of said posterior rigid foam ¾ component.

7. An insole according to claim 5, wherein said posterior rigid foam ¾ component comprises a contour along its forward edge, further provided that the forward medial point of said forward edge extends behind the first metatarsal and the forward lateral point of said forward edge extends behind the fifth metatarsal.

8. An insole according to claim 5, wherein further, said insole is prepared from polyurethane materials.

9. An insole according to claim 5, further provided that said contours reflect a lower profile along the lateral side of said insole and a higher profile along the medial side of said insole.

10. An insole according to claim 5, further provided that said posterior rigid foam ¾ component has one or more negative recesses along the top surface of said posterior rigid foam ¾ component and one or more positive protuberances along the bottom surface of said posterior rigid foam ¾ component.

11. An insole according to claim 5, wherein further, said flexible metatarsal region comprises a tapered leading edge.

12. A bi-layer footwear component comprising:

a. a first layer, wherein said first layer is comprised of a footbed comprising a protuberance in the subcalcaneous region of said footbed, wherein further, the anterior portion of said protuberance is larger relative to the posterior portion of said protuberance; and

b. a second layer, wherein said second layer is comprised of an insole comprising: 1) a posterior rigid foam ¾ component having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and

2) a flexible metatarsal region.

13. A bi-layer footwear component according to claim 12, wherein said footbed comprises a top layer of soft polyurethane foam, further provided that said protuberance in the subcalcaneous region of said footbed is a visco-elastic polyurethane elastomer.

14. A bi-layer footwear component according to claim 12, wherein said contours reflect a lower profile along the lateral side of said insole and a higher profile along the medial side of said insole.

15. A bi-layer footwear component according to claim 12, wherein said posterior rigid foam ¾ component has one or more negative recesses along the top surface of said posterior rigid foam ¾ component and one or more positive protuberances along the bottom surface of said posterior rigid foam ¾ component.

16. Shankless high-heel footwear comprising:

a. a footbed, said footbed comprising a protuberance in the subcalcaneous region of said footbed, wherein further, the anterior portion of said protuberance is larger relative to the posterior portion of said protuberance; and

b. a posterior rigid foam ¾ component having a depression in the subcalcaneous region; further provided that the longitudinal and medial arches of said insole follow the contours of the last; and

c. a flexible metatarsal region

17. A bi-layer footwear component comprising:

a. a first layer comprising a footbed having a protuberance in a subcalcaneous region of the footbed; and

b. a second layer including an insole comprising a posterior rigid heel portion having a depression in a subcalcaneous region of the rigid heel portion adapted to receive the protuberance of the footbed, a rigid arch region sized and shaped for extending under and supporting an arch of a wearer's foot free of any other supporting structure at the arch, and a flexible metatarsal region, the rigid heel portion and rigid arch portion being formed of the same material.

18. A bi-layer footwear component according to claim 17 wherein the rigid arch region has a generally channel-shaped cross section.

19. A b-layer footwear component according to claim 17, wherein the material forming the rigid heel region and the rigid arch region is a polymeric material.

20. A bi-layer footwear component according to claim 19 wherein the material forming the rigid heel region and the rigid arch region is polyurethane.

21. A bi-layer footwear component according to claim 19 wherein the material forming the rigid heel region and the rigid arch region is a foamed polymeric material.

22. A bi-layer footwear component according to claim 17 wherein the rigid heel region and the rigid arch region are formed as one piece.

23. A shankless high heel footwear comprising:

a. an outsole;

b. a heel;

c. an insole comprising a posterior rigid heel portion having a depression in a subcalcaneous region of the rigid heel portion and a rigid arch region sized and shaped for extending under and supporting an arch of a wearer's foot free of any other supporting structure at the arch, and a flexible metatarsal region, the rigid heel portion and rigid arch portion being formed of the same material;

d. a footbed having a protuberance in a subcalcaneous region of the footbed adapted to be received in the depression of the posterior rigid heel portion of the insole; and

e. an upper.

24. A shankless high heel footwear according to claim 23 wherein the rigid arch region has a general channel-shaped cross section.

25. A shankless high heel footwear according to claim 23 wherein the material forming the rigid heel region and the rigid arch region is a polymeric material.

26. A shankless high heel footwear according to claim 25 wherein the material forming the rigid heel region and the rigid arch region is polyurethane.

27. A shankless high heel footwear according to claim 25 wherein the material forming the rigid heel region and the rigid arch region is a foamed polymeric material.

28. A shankless high heel footwear according to claim 23 wherein the rigid heel region and rigid arch region are formed as one piece.