Internal Midsole Footwear Design Using Cooled Adhesive Bonding
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Solution Overview
Problem
Conventional footwear designs, particularly athletic shoes, have a pronounced and heavy sole structure due to the external midsole and outsole assembly, which hampers athletic performance and offers limited design options while compromising on weight, safety, stability, and comfort.
Innovation Solution
The design integrates a midsole completely within an interior chamber of the upper member, with optional outsole and heel members attached to the exterior surface, using a cement material that is cooled to allow movement before bonding, and applying additional elements like outsole members and heel units to create a lightweight and stable footwear structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a conventional external midsole and outsole assembly is used, then the footwear provides adequate structural support and durability, but the footwear weight increases and athletic performance is hampered
Solution Approach 1:
The midsole is repositioned from an external assembly to an internal component located within the interior chamber of the upper member. This dimensional repositioning eliminates the need for a pronounced external sole structure while maintaining internal structural support, thereby reducing footwear weight without compromising reliability
Solution Approach 2:
The midsole is integrated with the upper member through adhesive bonding within the interior chamber, merging two previously separate components (upper member and midsole) into a unified structure. This integration eliminates the need for separate external sole assemblies, reducing overall weight while maintaining structural integrity
2Adaptability or versatility
If a conventional external midsole and outsole assembly is used, then the footwear provides adequate structural support, but the sole structure becomes visually apparent and design versatility is limited
Solution Approach 1:
By moving the midsole to the interior chamber, the external shape of the footwear is no longer constrained by the need to accommodate an external sole assembly. This enables greater design freedom for the external shape and appearance while the midsole continues to provide internal structural support
Solution Approach 2:
The midsole is extracted from the external assembly and repositioned internally, removing the visual prominence of the sole structure from the footwear's external appearance. This allows for more versatile and aesthetically pleasing design options while maintaining the functional integrity of the sole
3Ease of manufacture
If cement material is applied and then cooled to allow movement, then the midsole can be properly positioned within the upper member, but the manufacturing process complexity increases
Solution Approach 1:
The temperature of the cement material is changed from ambient to cooled state during assembly, altering its physical properties to allow movement and positioning. After positioning, the temperature is returned to ambient or heated to activate bonding. This parameter change enables precise positioning while maintaining ease of manufacture
Solution Approach 2:
The cement material is cooled in advance before the midsole is positioned, preparing the bonding surface to allow movement. This preliminary cooling action enables proper positioning to be achieved before final bonding occurs, simplifying the overall assembly process despite the additional temperature control step
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 approach results in a lightweight footwear product that maintains safety and stability while eliminating the need for a visually apparent sole structure, enhancing athletic performance and design versatility.
Implementation Method 1
cooling at least one of the upper member or the midsole to a sufficient extent so that the midsole and upper member will move with respect to one another despite the presence of the cement material
Data Source
AI summary
Methods for making footwear products include: (a) applying cement to a surface of an upper and/or midsole; (b) cooling the upper and/or midsole so that these parts will move relative to one another despite the cement's presence; and (c) placing the midsole in the upper. Additional methods include: (a) providing an upper having an interior chamber; (b) placing a prelast member including a midsole allowance part into the chamber; (c) removing the prelast member; and (d) placing a midsole in the chamber. The upper and/or midsole may have cement applied thereto and may be cooled before the insertion step, as described above. When sufficiently cooled, the cement will not immediately bind the parts contacting it, but it will allow relative movement of these parts. After the midsole is positioned in the upper, the assembly may be heated to activate the cement and fix the parts together.