Sole Unit for Footwear and Footwear Incorporating Same
The present invention discloses a sole unit for shoes, sandals, boots, and other articles of footwear. The sole unit comprises at least one spring unit having at least a top wall and a bottom wall that define an opening to allow the top and bottom walls to converge under force, absorbing energy on impact and releasing energy on rebound. Variations in the longitudinal profile, transverse profile, spring-wall thickness, and spring-wall shape permit control over spring force in response to compression. A spring unit may further comprise one or more dampeners to modify the energy-storing properties of the spring unit. A spring unit may further comprise one or more bumpers that come into contact at predetermined distances when compressing the spring unit, to further modify the dynamic response of the spring under a load.
This application claims priority to and the benefit of U.S. Provisional Patent Application Nos. 60/609,937, filed Sep. 14, 2004 by Alan Hardy and Mark McMillan, and 60/610,302, filed Sep. 15, 2004 by Alan Hardy and Mark McMillan the disclosures of which are hereby incorporated by reference as if listed in their entirety.
BACKGROUND OF THE INVENTIONThe natural motions of the human foot during a foot strike (step) are complex and multidirectional, especially during sporting activities. Traditional footwear materials are generally very basic and cannot respond and react against these forces in a manner that compliments the natural variations in force and transitions of foot motion other than in a very linear and uniform way. Each sport and sporting activity has specific characteristics in terms of foot strike (stepping motions) and force transitions. Traditional cushioning elements are used in very similar ways for each sport, and therefore are only generally adaptable to the specific needs of each sport. Traditional cushioning materials offer a very similar effect to stepping onto a flat, cushioned floor surface with the disadvantage of exaggerated and unnatural torsional traction with the ground and occasionally unforgiving structural support from the footwear upper. Quite often, the consequence is less-than-optimal transitional results, greater instability, and higher likelihood of injury.
Footwear cushioning materials often offer only underfoot protection against basic linear impact shock, not against the rotational, torsional, and other more-complex dynamic movements related to foot and joint trauma. Therefore many traditional cushioning materials restrict and reduce the natural biomechanical responses from the foot and related joints and adjoining structure.
During most sports and athletic activities, the foot is subject to diverse and violent forces in terms of impact shock. Vertical, linear, lateral, and rotational (torsional) forces and motion transitions can be unnaturally high. These exaggerated forces can be attributed to advancements in the human condition, advancements of footwear design (traction/support) and technologies, and increasing physical requirements of the evolving sporting activities. The human foot is adaptable and well-suited to these dynamic requirements in terms of the biomechanical nature of the foot and ankle structure, but is somewhat disadvantaged by the more general and unspecific nature of the approaches at protection through footwear design and footwear engineering innovation.
Cushioning elements of most current sport and athletic footwear include basic shock absorbing and protective underfoot materials, such as foam, gel (visco-elastomers), structure or air springs, together with more traditional applications of upper design, for structure, support, and stability enhancement. Usually a consistent and uniform layer of shock absorbing and protective material, such as EVA or polyurethane foam, is placed between the foot and the ground.
These elements have limited structural adjustability and variability through design, due to the nature of the materials. Manufacturing limitations inherent in these materials also prove to be not very adaptable in terms of the variety of underfoot movements and kinetic dynamics during stepping or foot-strike motions. These traditional materials generally absorb shock in a spring-like manner, returning much of the energy in an uncontrolled fashion. Undampened or lightly dampened rebound is dissimilar to the natural function of the foot and its structural elements.
There have been some attempts to improve conventional sole units based on EVA or polyurethane foam, which have been the traditional footwear cushioning materials. In these attempts, polymer spring units have been placed in portions in the sole, particularly the heel portion, and in some cases the forefoot portion. See, for example, U.S. Pat. No. 5,461,800, which is hereby incorporated by reference in its entirety. The U.S. Pat. No. 5,461,800 patent discloses a foamless midsole unit, comprising upper and lower plates sandwiching transverse cylindrical units formed of resilient polymer. This system, as well as others, are based on constant linear geometry and protect the foot only against basic inertia shock, not against rotational, torsional, or other non-linear dynamic movements related to foot and joint trauma. Therefore many prior attempts restrict and reduce the natural biomechanical responses from the foot and related joints and adjoining structure. For example, the prior art typically has spring elements of a constant two-dimensional cross-section from rearfoot to forefoot and from the medial side to the lateral side. See, for example, U.S. Pat. No. 4,910,884, 6,625,905, or 5,337,492. However, these disclosures do not address, and in part restrict, a nonlinear asymmetrical foot strike and subsequent flex-transition from heel to toe.
There is a tremendous opportunity for improving the current state of general sporting footwear ride and cushioning by approaches catered to these specific requirements; for example, by utilizing a cushioning device that offers a finer level of regionally specific tuning and adaptable transitions for the complex and dynamic forces encountered by the foot, the forces the foot is subjected to, and by the foot's interaction with the ground during a foot strike or stepping action.
SUMMARY OF THE INVENTIONThe present invention is a sole unit for footwear that overcomes problems in the prior art by providing at least one spring unit, dampener, or contact bumper, alone or in combination, for example, as described below:
A shoe having a sole unit comprising a spring unit, wherein
the spring unit is adapted for use in footwear and having at least a top wall and a bottom wall;
an opening disposed between the top and bottom walls to allow the top and bottom walls to converge under force;
the spring unit comprising a first profile for at least a portion of the top and bottom walls that is generally oriented in a longitudinal axis, and a second profile for at least a portion of the top and bottom walls that is generally oriented along an axis transverse to the longitudinal axis;
the first profile providing a plurality of spring rates along the longitudinal axis, through varying, complex sectional shape and dimension in order to offer different and appropriate resistances and spring rates throughout the length and width of the unit; and
the second profile providing a plurality of spring rates along the transverse axis, also through varying, complex sectional shape and dimension.
A sole unit as described above wherein the first profile generally is converging going from a rearward end of the spring unit toward a frontward end of the spring unit.
A sole unit as described above wherein the first profile generally is converging going from a frontward end of the spring unit toward a rearward end of the spring unit.
A sole unit as described above wherein the second profile is generally converging going from a lateral side to a medial side, or medial side to lateral side, but may have multiple convergences in order to offer plurality of spring rates, depending on the directional load requirements.
A sole unit as described above wherein there are a plurality of sections of convergence or divergence between the lateral and medial sides of the second profile.
A sole unit as described above wherein between the lateral and medial sides of the second profile there are a plurality of sections of convergence or divergence.
A sole unit as described above wherein between the front and rear of the spring unit along the longitudinal axis there are a plurality of sections of convergence or divergence.
A sole unit as described above wherein along the longitudinal axis, there is a change in the uniformity of the top or bottom wall's responsiveness to force due to varying and changing sectional thicknesses throughout the surfaces, creating complex and non-uniform sections throughout the unit, together with different material types, hardnesses, and flexibilities, and with optional laminations and combinations of other shaped surfaces, the spring unit offers a tuned and structured variety of load resistances, and appropriate directional force management, dependent upon the requirements of the various typical foot-strike and load management requirements.
A sole unit as described above wherein the angles of the front and rear surfaces, combined with the radii at adjoining bottom and top walls can be adjusted to accommodate to different load, load direction, and energy transitional requirements, according to the particular purpose of the shoe.
A sole unit as described above further comprising one single, or a plurality of spring units, which may be connected or separate and independent, and which are placed in any and various areas of the underfoot, in any and various configurations including angular and diverse alignments which correspond to directional load transference during different foot strikes and transitions, and which are not restricted to any symmetry around any linear longitudinal or medial to lateral axis, in order to provide many different truly bio-mechanically correct and ergonomically appropriate options of foot-strike, force dissipation and complex loading transitions during foot strike, and so catering to different requirements of various users, and purposes of the shoe. For example,
A sole unit as described above further comprising a dampener which can be co-produced and integral with the unit, directly laminated to, or mechanically fixed to the unit, in part or in whole, in order to offer adaptability in constructions and customizable for particular footwear requirements.
A sole unit as described above wherein the dampener is associated with at least one surface of the spring unit, so that compression of the spring unit places the dampener under tension, creating a return force applied to the spring unit.
A sole unit as described above wherein the spring unit is located at a position in the rear lateral area of the heel of the underfoot, or at a position of the foot which makes contact with the ground first, during stepping or foot-strike motion, can have its long surfaces aligned transversely with this axis appropriate to foot-strike patterns typical to linear stepping motion, motion such as while running, or sideways lateral foot strike such as in court sport activity.
A sole unit as described above wherein the spring unit can be made from any material with spring-like, energy absorbing and energy storing qualities, such as polymers, metals, composites, or any appropriate combinations of these.
A sole unit as described above wherein the spring unit further comprises at least one bumper to limit travel of opposing walls of the spring unit.
A sole unit as described above wherein the dampener and the bumper can be designed to be integral and combined in the same element.
A sole unit comprising at least one spring unit, the spring unit having opposing top and bottom walls, spaced along an axis, the spring unit having a plurality of spring rates along at least a portion of the axis, and a dampener disposed between top and bottom walls.
A sole unit as described above wherein the dampener is disposed so that the length or elongation of the dampener does not exceed the maximum opening between the surfaces of the spring unit to which it is attached or aligned, thereby coming into tension at the point when the load on the spring unit is released and the forces are returned by the spring unit.
A sole unit as described above wherein the spring unit has continuous complex curved surfaces, including an upper, outer surface that conforms to the bottom shape of the foot, in the areas where the spring unit is located, together with included sectional thickness and shape alterations throughout its length in order to offer differing and appropriate resistances to loading.
A sole unit as described above wherein the spring unit has an upper, outer surface that conforms to the bottom shape of the foot includes surfaces that wrap up and around the side surfaces of the foot, in order to better control the foot position during transitional loading due to foot-strike motions in any direction.
A sole unit for footwear comprising a spring unit and a dampener, wherein the dampener is placed under tension when the spring is compressed, creating a return force applied to the spring unit.
The foregoing is not intended to be an exhaustive list of embodiments and features of the present invention. Persons skilled in the art are capable of appreciating other embodiments and features from the following detailed description in conjunction with the drawings.
These and other embodiments are described in more detail in the following detailed descriptions and the figures.
Referring to
As used herewithin, “shoe” refers to footwear generally and includes shoes, sandals, boots, and other footwear articles. “Sole unit” generally may comprise a midsole for energy absorption and/or return; an outsole material for surface contact and abrasion resistance and/or traction; or a single unit providing such midsole or outsole functions. While a sole unit would generally extend the length of the shoe, a sole unit could also comprise a unit that extends for a lesser area, such as, just the forefoot or rearfoot portion, or some other area of lesser length or width. “Spring rate” refers to spring resistance in response to compression, where a spring unit may have a plurality of spring rates as a result of variations in spring unit wall thickness, spring unit profile, and other features.
Looking more specifically at spring unit 16, which will be discussed as representative of spring units according to the present invention, spring unit 16 comprises a continuous closed-curve structure with an opening 18 oriented transverse to the longitudinal axis to the wearer's foot. For clarity, all figures depict a single spring unit 16 placed in the rearfoot section of sole unit 14, substantially under the standing wearer's heel. This depiction and the corresponding discussion is representative and exemplary. The use of multiple spring units 16 is within the scope of the present invention. The use of one or more spring units 16 placed in the rearfoot, midfoot, or forefoot sections of a shoe, alone or in any combination, is within the scope of the present invention. Furthermore, one or more spring units 16 may partly or wholly replace part or all of the conventional midsole material in any portion of a sole unit.
Referring to
Viewed from the side, the rear-most portion (heel) 22 of the embodiment of
Viewed transversely, as shown in
Generally, from outer-most edges of the upper surface and lower surface to inner-most edges 28, the sections, thicknesses, and angles are constantly varying in order to provide structural dynamics in order to propagate collapse and support in-line with natural foot-stride transitions. In the embodiment of
Contemplated materials for spring unit 14 include injected thermoplastics, such as, but not limited to, Hytrel polymer, PEBAX, and TPU, as well as other resilient polymers, thermo-set plastics, and metallic materials known in the art, alone or in combination, that can be shaped and formed into complex sections and shapes. Contemplated fabrication methods include molding, injection molding, direct-injection molding, one-time molding, composite molding, insert molding, co-molding separate materials, or other techniques known in the art, alone or in combination. Contemplated fabrication or assembly methods include adhesives, bonding agents, welding, mechanical bonding, or interlocking shapes, alone or in combination. Laminated structures are within the scope of the present invention.
The reason for the difference in configuration is that sole unit 16 is oriented in shoe 10 for court or lateral sport applications, in which containing initial heel-strike loads is not as important as containing lateral loads. Spring unit 16 therefore needs to ease the initial crash propagation, allowing a more-acute transition to lateral containment. Spring unit 316, in contrast, is designed for a linear sports shoe, such as a running shoe, where a larger moment of force needs to be contained in the lateral heel strike area. Spring unit 316 then transitions into a midfoot load. In shoe 10, as shown in
In
Referring now to
Top wall 432 and bottom wall 434 define an opening 436. Spring unit 416 therefore has a first profile along a longitudinal line that is generally a diamond shape. However, as in other embodiments, the diamond has rounded corners as opposed to sharper pointed corners to provide resilience and to improve fatigue resistance of the materials under stress cycles. In addition to diamond-shapes, profiles may range from trapezoidal, oval, curved, or compound forms. Spring cells 416a-n are connected to facilitate load transfer from cell to cell, during stages between initial foot strike and natural stepping motion. The use of multiple, smaller spring cells 416a-n effectively minimizes the wearer's perception of load transfer. Multiple, smaller cells 416a-n may be separated horizontally as well as vertically. The spring unit 416 shown in
Spring unit 616 may also include one or more ribs 617 that wrap up and around any part of the foot, in order to better-control foot position during transitional loading or foot-strike motions in any direction. For example, spring unit 616 may comprise one or more vertically extending ribs that support and surround the base of the foot, thereby enhancing the effect of the under-foot spring units. In this regard, upper 612 of shoe 610 may directly connect to the upper outer surface of the configuration. A major benefit of the spring-array structure of
The various embodiments of spring units 16, 316, 416, 516 and so on discussed herein may optionally be integrated with one or more dampeners to provide enhanced functionality. “Dampening” generally refers to the ability of certain materials to reduce the amplitude of oscillations, vibrations, or waves. In a shoe, shock from impact generates compression waves or other vibrations within the sole unit and particularly within spring unit 16, which by design stores energy during foot strike and releases it by toe-off. A purpose of a dampener is to control and deaden “ringing” oscillations within sole unit 14 and spring unit 16. As used herein, single or multiple dampeners are components of spring unit 16 are meant to modify the effects of the energy stored in the spring unit 16 and released after foot strike. A spring unit with a dampener absorbs and releases energy more slowly and efficiently than one without a dampener.
Contemplated dampening materials include visco-elastomer which may include various polyurethanes or gels. In addition, plain elastomer materials may be used; however, they may not provide as desirable dampening qualities on the spring unit as a visco-elastomer. Contemplated fabrication methods include molding, injection molding, direct-injection molding, one-time molding, composite molding, insert molding, co-molding separate materials, or other techniques known in the art, alone or in combination. Contemplated fabrication or assembly methods include adhesives, bonding agents, welding, mechanical bonding, or other mechanical or chemical fastening means know to persons in the art, alone or in combination. Laminated dampener structures are within the scope of the present invention.
Dampener 740 has a shank 744 terminated on at least one end by a head 746. Shank 744 passes through each divider 742 via an aperture 748, seen best in
Compressing spring unit 716 forces top wall 732 and bottom wall 734 closer together. Dividers 742 are elastomeric structures connected to walls 732 and 734, so the reduction in distance between walls 732 and 734 tends to increase the distance between dividers 742. For example, as shown in
Preferably, dampener 742 is mounted in a static or unloaded state. Static mounting enables dampener 740 to most-effectively address compression dampening and rebound dampening.
Dampener 740 may take on several configurations, parallel to the ground, mounted at an angle, or opposing surfaces in the spring, under tension or not under tension. In addition to mounting the dampener, it could be fully or partially circumferential around the spring unit; or it can be related to a specific spring cell or interconnect and interact with multiple spring cells.
Spring unit 816 shown in
Spring unit 1416 also has a plurality of bumpers spaced along top wall 1432 and bottom wall 1434. Compression reduces the distance between top wall 1432 and bottom wall 1432. At a predetermined distance, the upper bumper strikes the corresponding lower bumper, limiting the travel of spring unit 1416. The distance between each upper and lower bumper is one factor controlling the amount of compression required to make contact. The counterforce produced by contact between the bumpers depends in part on the choice of bumper material.
As shown in
Under compression, the behavior of spring unit 1816 and dampener 1840 is similar to that of the analogous parts of the embodiment of
Persons skilled in the art will recognize that many modifications and variations are possible in the details, materials, and arrangements of the parts and actions which have been described and illustrated in order to explain the nature of this invention and that such modifications and variations do not depart from the spirit and scope of the teachings and claims contained therein.
While the inventors understand that claims are not a necessary component of a provisional patent application, and therefore have not included detailed claims, the inventors reserve the right to claim, without limitation, at least the following subject matter.
Claims
1. A shoe having a sole unit comprising a spring unit, wherein
- the spring unit adapted for use in footwear and having at least a top wall and a bottom wall;
- an opening disposed between the top and bottom walls to allow the top and bottom walls to converge under force;
- the spring unit comprising a first profile for at least a portion of the top and bottom walls that is generally oriented in a longitudinal axis, and a second profile for at least a portion of the top and bottom walls that is generally oriented along an axis transverse to the longitudinal axis;
- the first profile providing a plurality of spring rates along the longitudinal axis; and
- the second profile providing a plurality of spring rates along the transverse axis.
2. The sole unit of claim 1 wherein the first profile generally is converging going from a rearward end of the spring unit toward a frontward end of the spring unit.
3. The sole unit of claim 1 wherein the first profile generally is converging going from a frontward end of the spring unit toward a rearward end of the spring unit.
4. The sole unit of claim 2 wherein the second profile is generally converging going from a lateral side to a medial side.
5. The sole unit of claim 4 wherein there are a plurality of sections of convergence or divergence between the lateral and medial sides of the second profile.
6. The sole unit of claim 1 wherein between the lateral and medial sides of the second profile there are a plurality of sections of convergence or divergence.
7. The sole unit of claim 1 wherein between the front and rear of the spring unit along the longitudinal axis there are a plurality of sections of convergence or divergence.
8. The sole unit of claim 1 wherein along the longitudinal axis, there is a change in the uniformity of the top or bottom walls responsiveness to force due to varying and changing sectional thicknesses throughout the surfaces, together with different material types, hardnesses, and flexibilities the spring unit offers a tuned and structured variety of load resistances, and appropriate directional force management, dependent upon the requirements of the various typical foot-strike and load management requirements.
9. The sole unit of claim 1 wherein the angles of the front and rear surfaces, combined with the radii at adjoining bottom and top walls can be adjusted to accommodate to different load, load direction, and energy transitional requirements, according to the particular purpose of the shoe.
10. The sole unit of claim 1 further comprising a plurality of spring units, which are placed in any and various areas of the underfoot, in any and various configurations, in order to provide many different options of foot-strike force dissipation and transitions, catering to different requirements of various users.
11. The sole unit of claim 1 further comprising a dampener.
12. The sole unit of claim 11 or claim 16 wherein the dampener is associated with at least one surface of the spring unit, so that compression of the spring unit places the dampener under tension, creating a return force applied to the spring unit.
13. The sole unit of claim 1 wherein the spring unit is located at a position in the rear lateral area of the heel of the underfoot, or at a position of the foot which makes contact with the ground first, during stepping or foot-strike motion, can have its long surfaces aligned transversely with this axis appropriate to foot-strike patterns typical to linear stepping motion, motion such as while running, or sideways lateral foot strike such as in court sport activity.
14. The sole unit of claim 1 wherein the spring unit can be made from any material with spring-like, energy absorbing and energy storing qualities, such as polymers, metals, composites, or any appropriate combinations of these.
15. The sole unit of claim 1 wherein the spring unit further comprises at least one bumper to limit travel of opposing walls of the spring unit.
16. A sole unit comprising at least one spring unit, the spring unit having opposing top and bottom walls, spaced along an axis, the spring unit having a plurality of spring rates along at least a portion of the axis, and a dampener disposed between top and bottom walls.
17. The sole unit of claim 16 wherein the dampener is disposed so that the length or elongation of the dampener does not exceed the maximum opening between the surfaces of the spring unit to which it is attached or aligned, thereby coming into tension at the point when the load on the spring unit is released and the forces are returned by the spring unit.
18. The sole unit of claim 1 wherein the spring unit has continuous complex curved surfaces, including an upper, outer surface that conforms to the bottom shape of the foot, in the areas where the spring unit is located.
19. The sole unit of claim 1 wherein the spring unit has an upper, outer surface that conforms to the bottom shape of the foot includes surfaces that wrap up and around the side surfaces of the foot, in order to better control the foot position during transitional loading due to foot-strike motions in any direction.
20. A sole unit for footwear comprising a spring unit and a dampener, wherein the dampener is placed under tension when the spring is compressed, creating a return force applied to the spring unit.
21. A spring unit according to claim 1 wherein through varying, complex sectional shape and dimension the unit provides different and appropriate resistances and spring rates throughout the length and width of the unit
Type: Application
Filed: Sep 14, 2005
Publication Date: Oct 23, 2008
Applicant: TRIPOD, L.L.C. (Beaverton, OR)
Inventors: Alan Hardy (Portland, OR), Mark McMillan (Banks, OR)
Application Number: 11/575,300
International Classification: A43B 13/28 (20060101); A43B 13/20 (20060101); A43B 21/28 (20060101);