Interlocking Insole Midsole Footwear Attachment
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Solution Overview
Problem
Existing footwear sole structures lack an efficient mechanism for attenuating impact and providing cushioning without the need for adhesives or fasteners, and they do not effectively manage foot motion and traction.
Innovation Solution
A multilayered sole structure featuring a compressible polymer foam insole and midsole with intermeshing egg-crate geometries, where the insole 'floats' on the midsole, eliminating the need for adhesives or fasteners, and an optional synthetic-rubber outsole for enhanced traction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesives or fasteners are used to attach the insole to the midsole, then the attachment strength is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent replaces adhesive bonding (chemical mechanism) with a mechanical interlocking system consisting of protrusions on the insole that fit into recesses on the midsole. This mechanical substitution eliminates the need for adhesives or fasteners, reducing device complexity while maintaining attachment strength through the interlocking geometry of the protrusion-recess features.
2Strength
If the insole is rigidly fixed to the midsole, then the attachment strength is improved, but the foot motion control and comfort are worsened
Solution Approach 1:
The patent implements a dynamic attachment system where the insole is secured to the midsole through interlocking protrusions and recesses that allow controlled relative motion. This dynamic connection enables the insole to move slightly with foot motion while maintaining secure attachment, providing both attachment strength and adaptability to foot movement for enhanced comfort and motion control.
3Device complexity
If a single-layer sole structure is used, then the device complexity is reduced, but the impact attenuation and cushioning performance are worsened
Solution Approach 1:
The patent divides the sole structure into multiple functional layers: an insole layer with protrusions for cushioning and motion control, a midsole layer with recesses for impact attenuation, and an outsole layer for traction. This segmentation of the sole structure into distinct layers with specialized functions improves impact attenuation and cushioning performance while the interlocking mechanism integrates these layers into a cohesive unit.
4Manufacturing precision
If the insole and midsole are independently molded as distinct structures, then the manufacturing precision is improved, but the attachment mechanism complexity increases
Solution Approach 1:
The patent combines the attachment function with the structural features of the insole and midsole by integrating protrusions and recesses directly into the molded surfaces of each component. This merging of attachment functionality with the existing structural elements allows independently molded parts to connect through a relatively simple interlocking mechanism, achieving manufacturing precision without excessive attachment mechanism complexity.
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
This configuration provides improved impact attenuation, enhanced energy return, and better foot motion control while maintaining a lightweight and comfortable feel, with the insole and midsole interlocking via complementary protrusions and pockets for secure alignment.
Implementation Method 1
a compressible polymer foam insole and midsole
Implementation Method 2
enhanced energy return
Data Source
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AI summary
Presented are footwear sole structures with foot-cushioning insoles movably mounted onto impact-attenuating midsoles, methods for making/using such sole structures, and footwear fabricated with such sole structures. A multilayered sole structure assembly includes an insole movably mounted on a midsole. The midsole is formed with a first compressible material and includes opposing upper and lower midsole surfaces, multiple protrusions projecting from the upper midsole surface, and multiple pockets recessed into the upper midsole surface and interleaved with the midsole protrusions. The insole, which is formed with a second compressible material distinct from the first compressible material, includes opposing upper and lower insole surfaces, multiple protrusions projecting from the lower insole surface and interleaved with the midsole protrusions, and multiple pockets recessed into the lower insole surface and interleaved with the insole protrusions. Each midsole protrusion nests within a respective insole pocket, while each insole protrusion nests within a respective midsole pocket.