Comfort Heel for Heeled Shoes

Abstract

A shoe shock absorbing and support system that is able to cushion the impact of a heel striking a surface to reduce injury and fatigue and to compensate for uneven surfaces while minimizing injury to the wearer. In a preferred embodiment of the present invention, a cushion layer formed of a soft, shock-absorption material is incorporated into the heel. The present invention also provides a multiple layer contour system that provides stability and cushioning without greatly increasing the thickness of the inner sole of the shoe.

Description

RELATED APPLICATIONS

This application is a continuation of Ser. No. 11/457,454 filed on Jul. 13, 2006 which is a continuation in part of Ser. No. 09/894,516 filed on Jun. 27, 2001 which claims priority from provisional application 60/214,086, filed on Jun. 27, 2000.

FIELD OF THE INVENTION

This application relates to the field of heeled shoes, and particularly to the field of providing comfort and stability in heeled shoes.

BACKGROUND OF THE INVENTION

The use of heeled shoes, and particularly shoes with high-heels, are prevalent in today's fashion. Typically, high-heeled fashion shoes are designed so that the heel of the foot wearing the shoe is higher than the toes. The heel of the shoe is typically formed of a hard plastic. The heel often is tapered so that the point of impact between the heel and surface is relatively small in cross-sectional area. Thus, the foot and body of the user of such shoes are subject to impressive forces when the heel strikes the ground. This impact is repeated numerous times while the user is walking. This repeated, high-energy impact causes discomfort, not only in the heel of the foot, but also transferred throughout the body of the user of such shoes. Additionally, since the heel is elevated, the impact forces the foot forward in the shoe, jamming the toes against the front of the shoe to cause further discomfort. The onset-rate, that is the rate at which the impact occurs and the forces are transmitted through hard narrow high heels, is typically very rapid. This rapid onset-rate does not allow time for the ankle, foot and leg muscles to adapt to the impact. This causes muscle and foot surface fatigue and increases vulnerability to twisting an ankle or other injuries.

The use of heeled shoes on uneven surfaces causes additional discomfort and danger. The angle of the foot relative to the surface creates a propensity for the user to roll or twist an ankle. Even if the ankle is not twisted, the surrounding muscles and ligaments are fatigued in trying to prevent the ankle from twisting or rolling. This is exacerbated even more by narrow or spike high-heels.

Another problem with existing high-heeled shoes is foot fatigue resulting from the elevated stance. This elevated position magnifies movement of the leg. The muscles in the ankle and lower leg are required to adjust to the movement of the leg from this position. This constant muscle contraction thus results in fatigue and cramping of the foot.

These and other problems are the result of the use of hard plastic heels as well as other types of heels in most heeled shoes. There have been attempts in the past to address these problems, but these attempts have not been successful at providing a heeled shoe that reduces the shock from the impact of the heel and surface while maintaining the lateral stability of the shoe. Examples of such prior attempts include U.S. Pat. Nos. 5,311,677; 4,876,805; 4,972,612; 4,429,473; 4,866,805 and many others disclose using cushioned insoles. Also, U.S. Pat. Nos. 5,063,691; 5,212,878; 5,212,878; and 5,782,014 disclose using shock absorbers in heels. However, none of these patents disclose any apparatus for maintaining lateral stability while providing increased shock absorption or any feature that will allow compensation for uneven surfaces. In many designs, increasing cushioning in heels with a small profile results in the heel becoming less stable since movement of the cushioning elements occurs over the entire heel. In this case, lateral stability is greatly sacrificed to provide cushioning.

U.S. Pat. No. 5,829,168 discloses a shock absorbing high heel that uses an inelastic rigid inner core for stabilization and an elastic outer envelope for shock-absorption. This design allows the heel to compress laterally and does not provide lateral stability or support for uneven surfaces.

Another problem that occurs with prior shoe designs is the lack of cushioning in the inner soles of the shoes, particularly in fashionable shoe designs. Typically, the shoe middle sole support structures are made of a thick paperboard and steel construction onto which an outer sole and insole is glued or attached. The inner sole may be formed with a heel cup and a slight arch at the mid portion to provide some measure of comfort to the wearer. However, in order to maintain the style and look of the shoe, and avoid the shoe sole body becoming thick in appearance, very little cushioning is provided. Also, in those shoes that attempt to provide additional cushioning, the stability of the shoe is often lost.

SUMMARY OF THE INVENTION

The present invention used in heeled fashion shoes provides a heel sub-assembly and/or a shoe heel that is able to cushion the impact of a heel striking a surface and lengthen the onset rate of impact as the heel first strikes. Thus, injury and fatigue is reduced from the use of heeled shoes, particularly with high-heeled shoes. Further, in a preferred embodiment, the present invention enables the shoe to maintain lateral stability and compensate for uneven surfaces and on both even and uneven surfaces to minimize fatigue and injury to the wearer.

In a preferred embodiment of the present invention, a cushion layer formed of a soft, shock-absorption material is incorporated into the heel between the tread and hard heel structure. The cushion layer provides greater shock absorption in the areas receiving the most impact from the heel striking a surface, namely the back edge of the heel that first strikes the ground. The heel cushion layer entirely contacts the ground as the entire foot touches the ground. The heel cushion at this point has cushioning yet is able to move only minimally laterally thus providing more support than cushioning

In a preferred embodiment of the present invention, the soft shock absorbing layer is in between the heel tread and the hard heel structure. The components of the heel sub-assembly can be affixed together by bonding, insert molding, bi-injection molding, adhesives, screws, pins, barbed fasteners, detents or other known fastening mechanisms.

In another preferred embodiment of the present invention, the shoe design provides greatly increased cushioning through the body of the foot while maintaining stability to the wearer. The support section of the shoe from the heel to the ball of the foot is made of a polymer that is much thinner and stronger than typical shoe midsoles. This allows more room in the shoe construction for a thicker cushioning layer providing more cushioning so that the overall aesthetic look of the shoe is not affected and comfort is greatly increased.

These and other features of the present invention are evident from the claims, and the detailed description of preferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded assembly perspective view of a preferred embodiment of the present invention.

FIG. 2 is a front perspective view of the heel subassembly of the embodiment of FIG. 1.

FIG. 3 is a bottom perspective view of the embodiment of FIG. 2.

FIG. 4 is an exploded view of another preferred embodiment of the present invention.

FIG. 5 is an exploded view of another preferred embodiment.

FIG. 6 is a cross-sectional view of another preferred embodiment.

FIGS. 7-9 are side views showing the action of the cushion layer of a preferred embodiment of the present invention during a heel strike movement.

FIG. 10 is a side cut-away view of a prior art shoe.

FIG. 11 is a side cut-away view of the contoured layer system of a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A preferred embodiment of the present invention is illustrated in FIGS. 1-10. It is to be expressly understood that the descriptive embodiments are provided herein for explanatory purposes only and are not meant to unduly limit the claimed inventions. The exemplary embodiments describe the present invention in terms of a cushioned heel subassembly and increased thickness cushion for use on heeled shoes, as shown in FIGS. 1-10. It is to be understood that the present invention is intended for use with other types of women's footwear that have elevated heels including high heels, mid heels, lower heels as well as elevated shoes having a heel of a wedge design, sandals, and other types of footwear having the heel surface higher that the forefoot surface.

The preferred embodiments of the present invention include two components that may be used either in combination with one another or separately to improve the comfort of wearing heeled shoes while still retaining the aesthetics and style of such shoes. These components include a cushion built into the heel of the shoe to minimize shock transferring to the user during a heel strike and a contoured inner sole system to provide increased cushioning while retaining the shape and style of the shoe.

Heel Cushion Component

In the preferred embodiment, shown in FIGS. 1-3, shoe 10 includes heel assembly 12 and sole 14. It is to be understood that the present invention is intended for use with women's footwear having an elevated heel portion. In this embodiment, heel 12 includes a heel sub-assembly 20 and a heel base 22. Generally, under the present invention, heel sub-assembly 20, shown in FIGS. 1-3, includes a heel tread with posts 30 and cushion layer 50. The cushion layer 40 is formed of a relatively soft, shock-absorbing material, such as, but not limited to rubber, plastic, urethane, cork, or other materials having shock-absorption properties. These two elements are typically attached to a rigid heel body that elevates the rear portion of the shoe 22. In the preferred embodiment, the cushion layer 50 is formed of polyether, or polyester or polyurethane elastomeric material with a Shore A hardness from 40 to 70.

The cushion layer 50, in a preferred embodiment of the present invention, absorbs at least a portion of the impact from the heel striking a surface while providing support, particularly at other locations in the cushion layer. In the preferred embodiment, the cushion layer 50 accomplishes this by allowing absorption of the shock by the thicker soft shock absorption material at the rear of the heel strike zone of the heel. Heel strike is defined as the impact occurring when the heel of the shoe hits the ground before the toe touches down during the stride of the wearer.

In the preferred embodiment shown in FIGS. 1-5, the material is much thicker at the strike area 70, thus more able to absorb impact at that location. The thinner area 72 of the cushion layer 50 is aligned perpendicular to the direction of the movement of the shoe. This causes the thicker material 70 to move more and absorb more shock during initial heel strike. Area 72 is thinner to offer less cushioning and greater stability as the shoe is flat to the ground. In this embodiment, the cushion layer 50 may also include pockets or voids 74 in the material to allow the material to displace easier at those locations.

The heel tread with posts 30, in the preferred embodiment, secures the cushion layer 50 to the hard heel structure 22 of the shoe in a manner that allows the cushion layer 50 to asymmetrically flex or flow. That is, the cushion layer 50 and the heel base 22 are able to flex forward, rearward and upward relative to the hard heel structure 22 but do not flex as much sideways or torsionally in order to maintain lateral stability. The flex may be accomplished by the cushion layer 50 actually flexing, but in a preferred embodiment, the material of the cushion layer 50 is displaced by the impact of the force of the heel strike especially in the areas of the thicker material. It bulges outwards and may move into perforations within the layer.

The design of the heel tread with posts 30 is accomplished in numerous variations and is not meant to be limited to these descriptive embodiments. The heel tread may include adhesives, pins, screws, button barbs or many other types of securing devices.

The heel tread 30 includes a plurality of post members 32, 34, 36, 38 that engage in mating holes 40, 42, 44, 46 formed in heel base 22. These post members 32-38 have mushroom shaped heads that are slightly larger than the body of the post members. The heel tread 30 may also include a centrally located hole 48 for decorative purposes. In this embodiment, heel tread is formed of a hard durable high-grip plastic material.

Cushion layer 50, in this preferred embodiment, is formed of a soft polyurethane material. The cushion layer 50 includes a plurality of holes 52, 54, 56, 58 aligned with the members 32, 34, 36, 38 of the mounting plate, a central cut out portion 60 and a tab member 62 extending partially into the cut-out portion 60.

The midsole 14, which will be described in greater detail below, includes an engagement member 76 extending downward into an aperture 24 in the heel base 22 to secure the sole to the heel assembly 12.

These components are assembled as shown in cross section in FIGS. 1-3. The post members 32-38 engage through holes 52-58 of the cushion layer 50 into holes 40-46 of the heel base. The engagement member 70 of the sole 12 is inserted through aperture 24 of the heel base 22, to engage the cut-out 62 of the cushion layer 50 with the open upper recess 48. The four posts 32-38 of the mounting plate are inserted through the holes 52-58 of the cushion layer 50 and into the holes 40-46 of the heel base 22. The mushroom shaped head portions of the posts deform into the holes 40-46 to form a retaining mechanism for securing the mounting plate and cushion layer to the heel base 22. Further retaining mechanisms may be used, such as adhesives, screws or other interlocking means, to secure the components to one another. The tab member 62, shown in FIG. 3, engages in the center hole 48 to minimize movement between the thinner center portion of the cushion layer 50 and the heel tread 30 and for cosmetic reasons. Thus, the components are easily and securely mounted to the heel base 22 of the shoe 10 in a snap-together fashion.

In preferred embodiments of the present invention, the cushion layer is varied in thickness. Different areas of the cushion layer 50 may have differing thickness and/or hardness. This provides greater shock absorption at the rear area that that receives the greatest impact. Other areas of the cushion layer that are thinner or harder to provide greater stability for the heel tread when it sits flat on the ground. In an alternative embodiment, the cushion layer may include a lateral bar extending from side to side to allow greater shock absorption at the rear or front of the heel while maintaining lateral stability in the heel. The thicker rear profile of the cushion layer 70 has an added benefit in that it lengthens the onset rate of impact by absorbing the impact more slowly than a typical hard heel tread and heel structure. This longer onset rate allows the muscles, tendons and bones of the foot and lower leg more time to compensate and meet the forces of impact thus greatly reducing fatigue to the lower extremity.

It is to be expressly understood that other types of fastening techniques can be used to provide the unique features of providing shock or impact absorption while maintaining lateral stability. For example, and without limiting other equivalent fastening mechanisms considered under the scope of the claimed inventions, mechanical fasteners such as barbs, screws, buttons may be used. Various shapes of the cushion layer and components provide the lateral stability while allowing non-symmetrical flexing of the cushion layer.

Another embodiment of the present invention for use with narrower heels is shown in FIG. 4. Since the heel area is much smaller, the heel assembly 140 uses a cushion layer 150 with a thicker area 152 and thinner area 154 and two holes 156, 158 extending through it. The heel tread with posts 160 includes two posts 162, 164 aligned with the holes 156, 158. The posts 162, 164 are inserted through the two holes 156, 158 and into mating holes of the heel base to secure the components to the heel base. The cushion layer 140 also performs similar to the above described embodiment. The thicker rear area 152 provides greater cushioning during the initial impact of a heel strike. The forward part of the cushion layer 154 is thinner to provide some cushioning with increased lateral stability. This design provides shock absorption without affecting the lateral stability of the heel that might cause imbalance to the shoe wearer. The two posts 162, 164 may be made of metal or other strong material that is co-molded with the heel tread material if the heel profile is very small for extra strength.

Another embodiment of the present invention is illustrated in FIG. 5. This embodiment includes a cushion layer 250 having a thicker area 252 and a thinner area 254. The heel tread 230 includes a single post 232. In this embodiment, the post 232 is in a T shape cross section that attaches the heel tread yet prevents rotation between the cushion layer 250 and the mounting plate 230, although other shapes may be used as well. These shapes may be a square, rectangle or other keyed shape that securely attached the heel tread while preventing rotation during use. The post 232 is inserted into a similar shaped hole 256 in the cushion layer 250 and into engagement with a similarly shaped hole in the heel base of the shoe. The cushion layer also performs similar to the above described embodiments. The thicker rear 252 provides greater cushioning during the impact of a heel strike. This provides shock absorption without affecting the lateral stability of the heel that might cause imbalance to the shoe wearer.

Another preferred embodiment is illustrated in FIG. 6. This embodiment uses an elevated wedge shaped heel 260. The wedge heel 260 includes a cushion layer insert 262. The cushion layer insert 262 has a thicker rear area 264 for absorbing the initial heel strike with a thinner front area 266 for providing cushioning and stability when the heel is parallel and in contact with the ground surface.

Other shapes and sizes and engagement mechanisms of the cushion layer and the mounting plate are considered to be within the scope of the presently claimed inventions that allow different portions of the cushion layer to absorb the impact of the heel strike while other portions of the cushion layer provide greater stability.

In use, as shown in FIGS. 7-9, the thicker area 70 of the cushion layer absorbs the impact of the initial heel strike. As the wearer's foot and shoe passes through the stride and the toe drops to the ground, as shown in FIGS. 8 and 9, the weight of the wearer is transferred to the thinner area 72 of the heel cushion layer. This area does not afford as much shock absorption which is not necessary as the shock has already been absorbed. Instead, this thinner area provides some shock absorption while providing greater lateral and torsional stability so that the wearer has greater control. This is important for heeled shoes as they are typically less stable and simply providing soft cushioning uniformly across the entire heel results in considerable loss of lateral stability as the soft heel flexes laterally. In addition, the thinner cushioning area allows the heel to conform to uneven surfaces increasing safety and comfort. The shoe of the preferred embodiment thus provides greater shock absorption where it is most needed while maintaining lateral stability and control and better adaptability to uneven surfaces.

Inner Sole Support and Cushioning

The second component of the overall system of the present invention, that can be used alone or in combination with the above described heel cushion, is the contoured layer system 100. The contoured layer system of the present invention is similar to the system described in U.S. Pat. Nos. 5,025,573; 5,572,805; and 5,575,098, assigned to the assignee of this patent application and incorporated herein by reference.

A cross-sectional view of a typical heeled shoe 10 is shown in FIG. 10. The shoe 10 includes an outer sole 14, formed of an abrasion resistant material known in the industry or other suitable materials, an inner sole 16 formed of resin filled cardboard, paper, or other typical material used for structural inner soles. These typical middle sole materials lack structural strength compared to modern polymer and reinforced plastic materials used in the preferred embodiment. Thus, they must be much thicker in profile to provide adequate strength. The typical heeled fashion shoe cushion layer 18 is very thin and provides only a minimal amount of cushioning. This is because high heel shoes have a high degree of aesthetic design that does not allow the thicker profiles for fashion reasons. Thus, typical heeled fashion shoe construction and materials only allow for a relatively thin layer of cushioning material when compared to more comfortable walking and athletic shoes.

The shoe of a preferred embodiment of the present invention is shown in FIGS. 1, 10 and 11. This shoe includes a contoured layer system 106. The contoured layer system 106 includes an upper cushion layer 108 and a structural polymer composite layer 110. The polymer composite layer 110 of this preferred embodiment is formed of modern strong high impact plastic that is far stronger than the typical structural materials described above. These polymers may be reinforced with fiberglass or other structural additives as well as thin metal reinforcements. This allows the structural polymer layer 110 to be much thinner in cross section than typical construction allowing many times thicker cushioning layers than a typical heeled fashion shoe as shown in FIG. 11.

It is to be expressly understood that other materials may be used as well that function in a substantially similar manner. The polymer layer 110 is molded into a contour that not only supports the contours of the foot in a comfortable manner but also provides stability as well. The contour layer may transition from a stiff heel portion 112 and arch portion 114 into a thinner, flexible portion 116 at the ball and toe portion of the shoe. The entire contour layer 110 provides stiffness laterally while allowing a degree of flexibility at the ball and toe portion to enable the foot of the shoe wearer to flex as they stride forward. This flexible portion 116 may be a separate part or may be over molded or co-molded as a unitized piece with the polymer layer 110 to increase stability and provide a smooth flex transition under the ball of the foot.

The cushion layer 108 is formed of a foam material that provides advanced cushioning and lengthens the onset of impact yet minimizes breaking down during use. This cushion layer also transitions from a thicker portion at the heel area to a thinner portion at the ball and toe box portion of the shoe and has a contoured shape to provide support to the bottom of the foot. The thick cushion layer 108 in the preferred embodiment is made of closed cell urethane foam, or closed cell polymer foam with a high degree of impact absorption, cushioning and durability as opposed to the typically used thin open cell foam layer found in typical heeled fashion shoes. The use of the unique composite layer having a relatively thin cross section enables the cushion layer to have sufficient thickness to greatly reduce the stress that occurs during walking thus increasing comfort.

This unique multiple layer contour system provides greater cushioning than previously available while keeping the thickness of the inner sole of the shoe at a relatively minimum for aesthetic and fashion reasons. In the preferred embodiment discussed above, the structural polymer midsole 110 is maintained at less than one eighth inch while the cushion layer 108 is maintained at more than one quarter inch. This is the inversion of typical heeled fashion shoe construction where the structural layer is maintained at more than one quarter inch and the cushioning layer is maintained at less than one eighth inch Additionally, the stability of the heel region and the lateral stability of the entire shoe is increased by the structural polymer midsole 110 along with the greater cushioning.

Heel Cushion Component Combined With Inner Sole Support and Cushioning

The previously described Inner Sole Support and Cushioning design is best used with the Heel Cushioning Component design as a complete system to substantially increase the cushioning, support and comfort of heeled fashion shoes while maintaining a low profile thin soled design as desired in fashion heeled shoes. The two designs work in tandem to reduce the onset rate of initial impact, increase support and stability to the entire foot, and provide smooth transitional impact absorption through the entire phase of stepping. The result is reduced fatigue to tendons, bones and muscles of the lower leg and foot in addition to increased stability and reduced incidence of injury. In addition, lengthening of the onset rate of impact at initial heel strike combined with increased support and cushioning through the surface of the sole reduces the forward force applied to the toes that compresses them into the front portion of the toe box thus addressing a common source of discomfort when wearing high heeled fashion shoes.

The two designs can also be used independently. The use of the Heel Cushion System may enable the cushion layer 108 to be further reduced in thickness while providing an improved level of comfort and fatigue reduction.

These and other features of the present invention are found in combination or singly. It is to be expressly understood that the above descriptions of embodiments are for explanatory purposes only and are not meant to limit the scope of the claimed inventions.

Claims

1. A shoe having an elevated heel, said shoe comprising:

a heel base on said elevated heel;

a cushion layer formed from a shock absorbing material mounted to said heel base;

said cushion layer including a thick portion at the rear of said shoe to absorb the initial impact of the heel strike and a thinner portion at the mid portion of said heel of said shoe to provide cushioning and stability when the shoe is substantially flat on the surface;

an inner sole;

a cushioning layer on said inner sole; and

a thin composite layer on said inner sole formed from a composite polymer material for providing a thin cross section with lateral stability that allow said cushioning layer to be several times thicker yet stay within a thin overall cross-section for fashion purposes.

2. The shoe of claim 1 wherein said cushion layer includes:

varying hardness of said cushion layer at differing parts of said cushion layer.

3. The shoe of claim 1 wherein said shoe includes:

said cushion layer having an asymmetrical shape to allow forward/rearward movement while minimizing lateral movement of said cushion layer relative to said heel base.

4. The shoe of claim 1 wherein said composite layer includes:

an overmolded fiberglass and urethane layer.

5. A shoe having an elevated heel, said shoe comprising:

a heel base on said elevated heel; and

a cushion layer formed from a shock absorbing material mounted to said heel base;

said cushion layer formed in an asymmetrical shape for providing shock absorption as said heel initially strikes a surface while providing lateral stability for said heel base as said heel is in substantial contact with the surface.

6. The shoe of claim 5 wherein said cushion layer includes:

a portion of said cushion layer having a thicker portion for greater shock absorption at the point of the heel strike.

7. The shoe of claim 5 wherein said cushion layer includes:

various thickness at differing parts of said cushion layer to provide shock absorption and stability for said heel base.

8. The shoe of claim 5 wherein said cushion layer includes:

a thick portion at the rear of said shoe to absorb the initial impact of the heel strike; and

a thinner portion at the mid portion of said heel of said shoe to provide cushioning and stability when the shoe is substantially flat on the surface.

9. The shoe of claim 5 wherein said cushion layer includes:

varying hardness of said cushion layer at differing parts of said cushion layer.

10. The shoe of claim 5 wherein said shoe includes:

said cushion layer having an asymmetrical shape to allow forward/rearward movement while minimizing lateral movement of said cushion layer relative to said heel base.

11. The shoe of claim 5 wherein said shoe further comprises:

an inner sole;

a cushioning layer on said inner sole; and

a thin composite layer on said inner sole formed from a rigid polymer material for providing lateral stability of the shoe while maintaining a thin profile.

12. The shoe of claim 5 wherein said contour layer includes:

an overmolded rigid polymer and soft urethane layer.

13. A shoe having an inner sole; said shoe comprising:

an inner sole;

a cushioning layer on said inner sole; and

a thin composite layer on said inner sole formed from a composite polymer material for providing a thin cross section that allow said cushioning layer to be several times thicker yet stay within a thin overall cross-section for fashion purposes.

14. The shoe of claim 13 wherein said contour layer includes:

an overmolded fiberglass and urethane layer.

15. The shoe of claim 13 wherein said shoe further comprises:

an elevated heel base on said shoe;

a cushion layer for attachment to the elevated heel base; and

a portion of said cushion layer having a thicker portion for shock absorption at the point of initial heel strike.

16. The shoe of claim 13 wherein said cushion layer includes:

various thickness at differing parts of said cushion layer to provide shock absorption and stability for said heel base.

17. The shoe of claim 13 wherein said cushion layer includes:

a thick portion at the rear of said shoe to absorb the initial impact of the heel strike; and

a thinner portion at the mid portion of said heel of said shoe to provide cushioning and stability when the shoe is substantially flat on the surface.