Laminated Midsole Structure for Footwear Shock Absorption
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Solution Overview
Problem
Midsoles with a single-layer structure face issues with permanent deformation and inadequate shock absorption due to repeated bending, particularly in the front foot portion, and fail to provide optimal arch support for varying foot arch heights, leading to discomfort and instability.
Innovation Solution
A layered midsole structure comprising a high-resilience first foamed body and a low-resilience second foamed body with a higher specific gravity, where the second foamed body has a lower recovery speed and is used in the majority of the front, middle, and rear foot portions, with specific hardness and thickness distributions to enhance shock absorption and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer midsole structure is used, then the device complexity is low, but the shock absorption performance and resistance to permanent deformation are insufficient
Solution Approach 1:
The midsole is divided into multiple layers with different materials: a first foamed body layer and a second foamed body layer. Each layer has distinct properties - the first layer provides initial cushioning while the second layer with lower resilience prevents permanent deformation. This segmentation allows each layer to perform its specific function, resolving the contradiction between reliability and complexity.
Solution Approach 2:
The invention uses composite material construction by combining two different foamed bodies with different resilience characteristics. The first foamed body has higher resilience for shock absorption, while the second foamed body has lower resilience for stability. This composite approach enables the midsole to achieve both shock absorption and resistance to permanent deformation simultaneously.
2Reliability
If a high-resilience foamed body is used throughout the midsole, then the shock absorption is improved, but the stability and load distribution linearity deteriorate
Solution Approach 1:
Different regions of the midsole are assigned different material properties. The first foamed body layer provides high-resilience shock absorption in areas requiring cushioning, while the second foamed body layer provides low-resilience stability in areas requiring load distribution. This local differentiation of material qualities resolves the contradiction between shock absorption and load distribution linearity.
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 layered structure improves shock absorption and stability by distributing load more linearly, preventing excessive deformation and maintaining stability even under high loads, while allowing for a lighter weight and improved arch support for varying foot shapes.
Implementation Method 1
the second foamed body has a greater specific gravity than the first foamed body, and is formed by a low-resilience material having a speed of recovering to its original shape after being deformed lower than that of the first foamed body
Implementation Method 2
the mid sole includes: an upper layer and a lower layer, wherein one of the upper layer and the lower layer includes a layer of a first foamed body having a thermoplastic resin component; in another one of the upper layer and the lower layer, one or two or more of a majority of a flat area of a front foot portion
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3B
AI summary
A mid sole arranged on an outsole having a tread surface, the mid sole including: an upper layer and a lower layer, wherein one of the upper layer and the lower layer includes a layer of a first foamed body having a thermoplastic resin component; in another one of the upper layer and the lower layer, one or two or more of a majority of a flat area of a front foot portion, a majority of a flat area of a middle foot portion, and a majority of a flat area of a rear foot portion includes a layer of a second foamed body having a thermoplastic resin component; and the second foamed body has a greater specific gravity than the first foamed body, and is formed by a low-resilience material having a low speed of recovering to its original shape after being deformed.