Wave Spring Footwear Sole for Impact Absorption

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Solution Overview

Problem

Current footwear cushioning technologies, such as foams and springs, fail to effectively absorb impact energy while maintaining stability and energy return, leading to potential injuries and reduced athletic performance.

Innovation Solution

Incorporating wave springs encapsulated in compressible materials within the shoe sole, particularly in the heel and ball areas, to absorb impact and return energy during foot strikes, enhancing comfort and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If compression springs are used for cushioning in footwear, then impact absorption is provided, but the spring constant is not appropriate for footwear as the spring is either fully compressed or not compressed enough

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidspring compression appropriateness
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent changes the spring constant parameter by using wave springs instead of conventional compression springs. Wave springs provide a more appropriate spring constant for footwear that allows optimal compression during heel strike while maintaining stability, resolving the issue of springs being either fully compressed or not compressed enough.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the conventional compression spring mechanism with a wave spring mechanism. This substitution provides a more suitable mechanical system for footwear cushioning, enabling the spring to operate within an optimal compression range during normal walking and running forces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If torsion springs are used for cushioning in footwear, then impact absorption is provided, but the spring force is placed over a very small area

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidspring force distribution area
Core Design Contradiction:
Loss of energyVSArea of stationary object

Solution Approach 1:

The patent changes the spring type from torsion spring to wave spring, which fundamentally alters how the spring force is distributed. Wave springs provide a more distributed force pattern across a larger area of the shoe sole, reducing pressure concentration and improving comfort.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If wave springs are used in footwear, then impact energy is absorbed and energy is returned during foot strikes, but the spring structure becomes more complex

Engineering Contradiction:
Improveimpact energy absorption and returnVSAvoidspring structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent replaces complex multi-component spring assemblies with wave springs that provide both cushioning and energy return in a single integrated structure. This substitution reduces overall device complexity while achieving superior impact energy management through the inherent properties of wave spring mechanics.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The wave spring system effectively reduces impact, decreases injury risk, and recovers energy for more efficient movement, while extending the shoe's lifespan by sharing energy absorption and return with the spring.

Implementation Method 1

Wave springs, which may be encapsulated in a compressible plastic and/or polymer, may be placed in the sole of a shoe... to cushion the impact of foot strikes

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

Wave springs... may return a portion of the impact energy to the user for more efficient jumping, walking and/or running

Methodology Applied
Scientific EffectElastic recovery: Elastic Recovery

Implementation Method 3

Wave springs, which may be encapsulated in a compressible plastic and/or polymer... to cushion the impact of foot strikes

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP3675674B1Spring cushioned shoe with encapsulated spring
Publication Date: 2024.05.01 SPIRA INC
  • EP3675674B1 patent drawingFigure 1
  • EP3675674B1 patent drawingFigure 2
  • EP3675674B1 patent drawingFigure 3

AI summary

A sole assembly for an article of footwear comprises a midsole, a sole having a heel region, and a first wave spring disposed within a vacuity located within the heel region. The wave spring includes a top surface and a bottom surface. A plate, resting upon the top surface of the wave spring, is unsecured to the midsole and sized to permit movement within the vacuity along with the wave spring responsive to a rolling foot strike.