Shoe Sole Lateral Roll-Up Portion for Stability

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Solution Overview

Problem

Existing shoe soles for court sports, such as tennis and basketball, face challenges in preventing lateral shake while maintaining sole bendability and impact absorption, with current solutions either leading to excessive rigidity or increased lateral shake due to hardness variations in midsole layers.

Innovation Solution

A shoe sole design featuring a lower midsole with a high-hardness lateral roll-up portion and a softer medial portion, combined with an upper midsole that is softer laterally and softer medially, to support the foot without excessive rigidity or collapse, using a foamed resin body to enhance stability and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the upper-layer midsole is made hard to support lateral force, then lateral shake prevention is improved, but the bending rigidity becomes excessively high and bendability lowers

Engineering Contradiction:
Improvelateral shake preventionVSAvoidsole bendability
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The midsole is designed with different hardness levels in different regions: the lateral portion (including roll-up portion) has higher hardness for lateral support, while the central portion has lower hardness for bendability and comfort. This local differentiation resolves the contradiction by providing hard support only where needed for lateral stability without making the entire sole rigid.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The midsole is segmented into multiple portions with different hardness characteristics: a hard lateral portion for stability and a soft central portion for flexibility. This segmentation allows each region to perform its specific function independently, preventing lateral shake while maintaining sole bendability.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If the upper-layer midsole is made hard to prevent lateral shake, then lateral stability is improved, but the impact-absorbing property near the foot sole lowers

Engineering Contradiction:
Improvelateral stabilityVSAvoidimpact on foot sole
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The midsole uses local quality differentiation where the lateral portion is hard for stability while the central portion near the foot sole is soft for impact absorption. This ensures that impact forces are absorbed by the softer central region without compromising lateral support from the harder lateral region.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the hardness of the roll-up portion is decreased to improve bendability, then sole flexibility is improved, but the roll-up portion collapses and lateral shake increases

Engineering Contradiction:
Improvesole flexibilityVSAvoidlateral shake prevention
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The roll-up portion is designed with high hardness to maintain its structural integrity and prevent collapse, while the central portion maintains low hardness for flexibility. This local differentiation allows the roll-up portion to provide lateral support without compromising overall sole flexibility.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2848144B1Sole provided with outer sole and midsole
Publication Date: 2020.04.29 ASICS CORP
  • EP2848144B1 patent drawingFigure 1
  • EP2848144B1 patent drawingFigure 2
  • EP2848144B1 patent drawingFigure 3A~3B

AI summary

A shoe sole including an outsole 2 and a midsole 1, wherein: the midsole 1 includes a lower midsole 4 of a lower layer formed by a foamed body of a resin, and an upper midsole 3 of an upper layer formed by a foamed body of a resin and arranged on the lower midsole 4; a lateral roll-up portion 42 for supporting a lateral side of a foot from a side of the foot is formed integrally with the lower midsole 4; a hardness of a lateral portion 40 of the lower midsole 4 including the lateral roll-up portion 42 is a first hardness; a hardness of a medial portion 41 of the lower midsole 4 is a second hardness lower than the first hardness; a hardness of a lateral portion 30 of the upper midsole 3 is a third hardness lower than the first hardness; and a part or a whole of the high-hardness lateral roll-up portion 42 is protruding in an upward direction past the upper midsole 3 on a lateral side of the upper midsole 3 so that the lateral side of the foot is supported by the lateral roll-up portion 42 from the side of the foot without being supported by the upper midsole 3 from the side of the foot.