Patent Application
20050262736
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.
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:
The present invention also relates to a bi-layer footwear component comprising:
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 (Wp=Wi−Wa). 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 (Va=Wa/D, Vp=Wp/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 (((Vp−Va)/Va)×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.
a illustrates a bottom view of the footbed of the present invention comprising the subcalcaneous protuberance.
b illustrates a side view of the footbed of the present invention comprising the subcalcaneous protuberance.
a illustrates a top view of the insole of the present invention comprising the subcalcaneous depression.
b illustrates a side view of the insole of the present invention comprising the subcalcaneous depression.
c illustrates a rear view of the insole of the present invention comprising the subcalcaneous depression.
d illustrates a cross-sectional view taken across lines 2d-2d of
a 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.
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:
The present invention also relates to a bi-layer footwear component comprising:
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
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:
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
In an embodiment of the present invention, as illustrated by
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:
The procedure for producing the flexible forefoot component, as illustrated in
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:
The procedure for producing the flexible forefoot component, as illustrated in
In an embodiment of the present invention, the posterior rigid, three-quarter component of the insole, as illustrated by
The procedure for producing the rigid, three-quarter, posterior, insole component with said polyol resin blend, as illustrated in
In another embodiment of the present invention, the posterior rigid, three-quarter component of the insole, as illustrated by
The procedure for producing the rigid, three-quarter, posterior, insole component with said polyol resin blend, as illustrated in
In an embodiment of the present invention, as illustrated by
In another embodiment of the present invention, as illustrated by
a and 1b illustrate an embodiment of the footbed (3) of the present invention comprising the protuberance in the subcalcaneous region (10).
a, 2b, 2c and 2d illustrate an embodiment of the insole (13) of the present invention comprising the subcalcaneous depression (4).
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
Further, the footbed, as illustrated by
The application of Norman Dean, entitled FOOTWEAR HAVING A HEEL AND HEEL BREAST, filed simultaneously herewith is incorporated by reference.
