Patent Application
20120047767
The present invention relates to a shoe construction with improved comfort and has particular utility in connection with various types of footwear.
At first glance, dress shoes are stylish, trendy and make a strong fashion statement. However, most design detail and attention is focused on the outside of the shoe rather than on the inside. A closer look beyond the cosmetic design details reveals that the base materials used to construct the shoe are rigid, dense, inflexible, have mostly flat foot contacting surfaces and low density foam padding that is initially soft but “bottoms out” immediately. While comfort is always marketed, it is not always delivered.
Throughout the years, shoes have been made lighter, more durable and more comfortable. Numerous patents have been issued relating to structures attempting to accomplish this goal. Typically, comfort has been achieved by the addition of cushioning to a shoe construction, for example, by providing foam or gel pad inserts and/or foam or gel insoles. Numerous combinations of these types of components have been used in shoes to provide comfort. In most cases, layers of foam or other similar materials are added to the sole construction to create the initial perception of comfort but such constructions typically lose their effect in a short time and actually create discomfort. Beneath the soft foam are hard, stiff structural components. A wearer of these shoes typically compromises on comfort in order to wear the stylish shoes. The stylish shapes designed into the uppers of shoes do not translate into comfort when applied to the bottoms. Insole, sockliner and bottom shapes don't match the plantar surface of a person's foot.
Nonetheless, many conventional shoes such as high-heeled shoes have a reputation for being extremely popular yet uncomfortable because raising the heel is unnatural and such a construction creates anatomical issues and pain. The wearer's weight is shifted forward from the heel and arch areas to the forefoot and toe areas, creating high pressure and concentrating up to 70%-80% of the wearer's weight to these areas. Thus, it is known that many users of such shoes experience foot pain related to the shoes immediately, and the majority of users experience such pain after as little as several hours of use.
When the shapes of the insole and sockliner don't match the plantar surface of a wearer's foot, such shoe interiors have minimal/low arch and heel contact with the foot. Combining this with inflexible soles increases pressure during flex and toe off, creating pressures in this area up to four times higher as compared to standing still.
While many improvements have been made, there is still a need for an improved light weight shoe sole construction particularly useful in high-heeled footwear with improved comfort.
It is therefore desirable to provide an improved shoe sole construction for various types of footwear including high-heeled footwear. The most important factor to address in all footwear and, particularly, in high-heeled footwear, is better distribution of foot pressure, especially as the heel height is increased. Introducing anatomical shapes to support the heel and arch areas is needed to alleviate forefoot discomfort and improve comfort.
Specific advantages and features of the present invention will be apparent from the attached drawings and the description of an illustrative embodiment of the present invention.
The present invention is designed for incorporation into an article of footwear. Although the present invention will be described in connection with a conventional high-heeled sole having an outsole for engaging the ground, it is likewise well-suited for use in essentially any type of shoe construction including a sole construction having a midsole and shoe constructions having low heel or no heel (flat) configurations. The present invention involves the provision of an insert assembly including a sockliner and an insole board, the sockliner being anatomically shaped to reflect the natural shape of a wearer's foot and being superimposed or positioned in overlying relationship to the insole board. The insole board includes a relatively rigid board member extending from a heel area to at least a midfoot area and is formed and shaped to provide a consistent foundation for supporting the anatomically shaped sockliner. The sockliner is then secured in the shoe for supporting a wearer's foot.
The sockliner of the present invention includes a raised area in the midfoot region and a recessed area located in the hind foot or heel region. The raised area is positioned to underlie the medial arch of the wearer's foot and the recessed area is positioned to underlie the heel of the wearer's foot. The recessed area is defined by the peripheral edges formed around the hind foot region from the medial side to the lateral side of the heel. The peripheral edge in the hind foot region forms a raised portion where it wraps around the heel of the wearer's foot.
The anatomically shaped and formed sockliner is designed from the inside out and reflects the natural shapes of the human foot. The shaped plantar surface topography maximizes surface contact with the wearer's foot and increases comfort. An extended “heel seat” design in the sockliner utilizes more of the rear part of the foot and shoe to bear weight and distribute pressure. A reduced heel center thickness is provided to avoid peak heel pressure during heel impact.
The insole board of the present invention extends from the rear of the shoe forward to an area adjacent the ball of the foot. The top surface of the insole board is shaped to conform somewhat to the shape of the bottom surface of the sockliner. The insole board generally lies on the top of the outsole or midsole if the midsole is used. The insole board preferably terminates adjacent the ball of the foot and is preferably made of a rigid pressed fiberboard material. A forefoot insole portion may be provided to extend from the terminal end of the insole board to the toe portion of the shoe. A shank may also be positioned inside the insole board. The top surface of the insole board forms recesses which open upwardly.
The shape and outline of the sockliner reflects the natural shapes of the human foot. The molded or formed insole board with a concaved heel seat creates an improved foundation to support the sockliner and the human foot. As the foot is “loaded” with body weight during heel strike, the present sockliner compresses and fills the formed concaved insole board member and supports the foot, insuring maximum contact. This formed board member effectively locks in the anatomical shape within the shoe and prevents inconsistencies in assembly.
When a foot is inserted into a shoe that houses the present sockliner, the recessed area of the sockliner serves to receive and locate the heel in a substantially concaved heel area, and the raised area portion supports the medial arch of the wearer's foot so that the sockliner contacts substantially the entire bottom surface of the wearer's foot. The combination of a raised area under the medial arch, a recessed area immediately under the heel, and the use of a sockliner material that does not bottom out improves the distribution of the pressure and the comfort of shoes made in accordance with the teachings of the present invention.
These and other objects and advantages of the present invention will become more apparent to those skilled in the art after considering the following detailed specification taken in conjunction with the accompanying drawings.
It should be understood that the present drawings are not necessarily to scale and that the present embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should also be understood that the present invention is not necessarily limited to the particular embodiments illustrated herein. Like numbers utilized throughout the various Figures designate like or similar parts or structure.
In the present invention, an insert assembly is provided which improves comfort and can be installed in any type of shoe. For purposes of this invention, it is to be understood that high-heeled shoes include all footwear having a heel which elevates the heel of a person's foot above the midfoot and/or forefoot portions of a wearer's foot. The benefits of the present invention are achieved when a raised area is positioned in a shoe to underlie the medial arch area and a concaved area is formed to underlie the heel area. Preferably, the insert assembly of the present invention functions as the insole board and/or sockliner of a high-heeled footwear. Although the present insert assembly will be disclosed in connection with a typical high-heeled shoe, those skilled in the art will recognize that any type of shoe can be used with the present insert assembly without departing from the spirit and scope of the present invention.
The reference numeral 1 designates generally a shoe construction as illustrated in
The present invention relates to the construction of the insert assembly 10 and its combination with the other elements of a typical shoe such as the upper 3, the forefoot insole portion 18 and the outsole 7.
The foot of a human may be considered to have three regions, the forefoot region (area adjacent the toes), the midfoot region (area adjacent the arch), and the hind foot region (area adjacent the heel). The midfoot region is that area between the forefoot and the hind foot regions. The sockliner 15 of the present insert assembly 10 includes three regions substantially underlying the above-referenced corresponding three regions of the wearer's foot. The forefoot region of the sockliner 15 is designated generally A, the midfoot region is designated generally B, and the hind foot region is designated generally C as best illustrated in
As illustrated in the foot pressure distribution diagram of
The insert assembly 10 is preferably comprised of two superposed layers designated generally as a sockliner 15 and an insole board 17 (
The sockliner 15 has a top surface 21 and a bottom surface 24. The top surface 21 is positioned and oriented for engagement with a foot. Since the sockliner 15 is designed to support the foot and to be incorporated into conventional footwear, the sockliner 15 is generally foot-shaped. The sockliner 15 may, however, take on other shapes, as desired, to accommodate various alternative sole designs. The sockliner 15 includes a generally smooth top surface 21 designed to support the wearer's foot. The top surface 21 is shaped to match the natural shape or silhouette of the wearer's foot, for example, by providing the top surface 21 with a concaved heel area 33 and a raised arch area 23 as will be hereinafter further explained. The sockliner 15 of the illustrated embodiment further includes a peripheral lip 22 that extends upwardly around the peripheral edge of the sockliner 15 in the hind foot region. The sockliner 15 directly engages the undersurface of the wearer's foot.
In the illustrated embodiment, the sockliner 15 includes one raised area 23 in the midfoot region B. The raised area 23 (
The apex of the raised area 23 is preferably between about 2 mm and about 25 mm higher than the top surface 21 of the sockliner 15 located immediately forward of the forward raised area location 20 (
The sockliner 15 further includes a recessed area 33 located in the hind foot region C. The top surface 21 of the hind foot region C forms a recessed portion lying under the area of the calcaneus so as to receive the wearer's heel. The recessed area 33 is positioned to underlie the heel 35 of the wearer's foot as best seen in
The thicknesses of the sockliner 15 varies from the hind foot region C to the midfoot region B and the forefoot region A. The minimum thickness is in the forefoot region A where the thickness of the sockliner 15 is typically in the range of about 1 mm to about 5 mm. In the midfoot region B, the thickness of the sockliner 15 can vary from about 0.5 mm at the edges to up to about 25 mm at the arch area depending on the shoe as best seen in the cross sectional views from the medial to lateral sides as illustrated in
Further, the overall dimensions of the present insert assembly 10 as well as the specific shape and configuration of the various sections thereof are also subject to wide variations and may be sized and shaped into a wide variety of different sizes and configurations so as to be compatible with the size and shape of the particular footwear onto which the present structures may be mounted, or to conform with any space limitations associated therewith out impairing the teachings and practice of the present invention.
It is also understood that various modifications may be made to all of the various embodiments without departing from the spirit and scope of the present invention.
The sockliner 15 can be a molded foam layer, for example, a cellular type non-rigid foam, and depending upon the particular characteristics needed in the layer 15, the material can be an open cell or a closed cell foam. Preferably, the sockliner 15 is formed from a flexible material, e.g., molded flexible plastic or rubber, such as polyurethane, thermoplastic elastomer (TPE), latex, thermoplastic rubber (TPR), ethylene vinyl acetate (EVA), rubber sponge, specialty elastomers, or the like. Preferably, the hardness of the sockliner 15 is in the range of between about 15 and about 60 ASKER C scale. The density of the sockliner 15 is in the range of between about 0.10 and about 0.40 g/cc.
In one embodiment, it is desirable to have predictable performance characteristics of the foam to be used. One way to measure this is by a compression/deflection graph such as the representative compression/deflection graph illustrated in
As shown, the insert assembly 10 also includes an insole board 17 that extends from the rear of the shoe 1 forward to an area adjacent the ball 31 of the foot. In another embodiment, the insole board 17 may extend from the heel to the toe area, or a forefoot insole member such as forefoot insole portion 18 may be utilized to extend from or overlap with the terminal end of the insole board 17 as illustrated in
The top surface 42 of the insole board 17 includes recesses and is shaped to conform to the bottom surface 24 of the sockliner 15. The recesses are upwardly opening. Preferably the proximal and distal ends of the insole board 17 have a depth that results in their being flush with the bottom surface 24 of the sockliner 15 where it wraps around the bottom surface 24 of the sockliner 15. Preferably the peripheral edges of the insole board 17 have a shape corresponding to a shape of the bottom surface 24 of the sockliner 15. The insole board 17 has a peripheral edge configuration substantially parallel to the outer peripheral edge configuration of the bottom surface 24 of the sockliner 15, but slightly larger than the outline of the sockliner 15.
In use, the insert assembly 10 is located within a shoe 1 with its heel end at the back of the shoe so that the recessed area 33 underlies substantially the heel 35 of the wearer such that the recessed area 33 receives and the sockliner 15 wraps around a substantial portion of the heel of the wearer. From there, the sockliner 15 extends forwardly to the midfoot region having the raised area 23. The raised area 23 underlies substantially the medial arch area of the wearer's foot. The raised area 23 tapers toward the distal end of the sockliner 15. Thus, when a wearer's foot is inserted into a shoe that houses the present sockliner 15, the recessed area 33 serves to locate the heel on a substantially concave surface. The raised area 23 positions and supports the medial arch of the foot so that the sockliner 15 contacts the entire bottom surface of the foot. It should be noted that contrary to the teachings of the prior art, the present invention provides a recessed area 33 for receiving the heel of the wearer's foot and a raised area 23 for supporting the arch of the wearer's foot. The combination of a raised area 23 under the medial arch, a recessed area 33 immediately under the heel, and the use of a foam material that doesn't exceed a deflection range of about 50%-80% for a given dynamic weight/load expected within the shoe, that is, the material does not bottom out, improves the comfort of shoes made in accordance with the present invention.
Thus, there has been shown and described several embodiments of an anatomical shoe insert construction. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present invention will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.
