Sole Unit for Footwear and Footwear Incorporating Same

Abstract

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]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 INVENTION[0002]The 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 there...

AI Technical Summary

Benefits of technology

[0037]These and other embodiments are described in more det

Problems solved by technology

The natural motions of the human foot during a foot strike (step) are complex and multidirectional, especially during sporting activities.

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.

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.

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.

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.

Therefore many prior attempts restrict and reduce the natural biomechanical responses from the foot and related joints and adjoining structure.

However, these disclosures do not address, and in part restrict, a nonlinear asymmetrical foot strike and subsequent flex-transition from heel to toe.

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