Direct Attach Footwear Sole with Visible Insert

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Solution Overview

Problem

Traditional footwear manufacturing methods involve multiple steps and adhesives that increase manufacturing time, cost, and potential defects, while also affecting the aesthetic and performance of the shoe.

Innovation Solution

A direct attach process where a polymeric foam composition is injected into a mold with the upper present, forming a mechanical and chemical bond with the upper to create a sole, eliminating the need for adhesives and ensuring alignment and fit, with an insert forming a visible portion of the sole sidewall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional multi-step adhesive bonding process is used, then alignment and bonding can be achieved, but manufacturing time and cost increase

Engineering Contradiction:
Improvealignment precisionVSAvoidmanufacturing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent combines multiple separate operations (aligning the sole, applying adhesive, and bonding) into a single injection molding operation. The pre-foam insert is positioned in the mold cavity, and the polymeric foam composition is injected to simultaneously bond the sole to the upper in one continuous process, eliminating the need for separate alignment and adhesive application steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent incorporates the pre-foam insert into the mold cavity before injecting the polymeric foam composition. This preliminary positioning of the insert ensures proper alignment and fit is achieved before the bonding process begins, allowing the sole to be pre-aligned with the upper during the molding process itself rather than requiring separate alignment steps.

Inventive Principle:
Principle #10Preliminary action

2Strength

If traditional adhesive bonding is used, then sole and upper can be joined, but manufacturing cost and potential defects increase

Engineering Contradiction:
Improvebond strengthVSAvoidmanufacturing simplicity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates the adhesive substance from the bonding process entirely. Instead of using chemical adhesives to join the sole and upper, the process relies on the mechanical interlocking and chemical bonding properties of the polymeric foam composition that forms the sole itself, creating a direct bond without intermediate adhesive materials.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a composite construction where a pre-foam insert (first material) is combined with injected polymeric foam composition (second material) to form the sole. This composite approach creates a bonded interface between different foam materials that directly attaches to the upper, eliminating the need for separate adhesives while maintaining bond strength.

Inventive Principle:
Principle #40Composite materials

3Productivity

If direct attach process with insert is used, then manufacturing efficiency improves, but process complexity increases

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the sole construction into two distinct components: a pre-foam insert and an injected polymeric foam composition. This segmentation allows each component to serve a specific function (the insert provides structural framework and the injected material provides bonding and cushioning), simplifying the overall process by dividing the sole creation into manageable stages within a single molding operation.

Inventive Principle:
Principle #1Segmentation

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

Reduces manufacturing time and cost, minimizes defects, and enhances the aesthetic and performance of the shoe by eliminating adhesives and ensuring precise alignment and fit.

Implementation Method 1

forming a mechanical and chemical bond with the upper to create a sole

Methodology Applied
Scientific EffectMechanical bond:

Implementation Method 2

forming a mechanical and chemical bond with the upper to create a sole

Methodology Applied
Scientific EffectChemical bond: Chemical Bonding

Data Source

PatentEP3764831B1Direct bottomed article of footwear with an insert
Publication Date: 2025.06.25 NIKE INNOVATE CV
  • EP3764831B1 patent drawingFigure 1~2
  • EP3764831B1 patent drawingFigure 3~4
  • EP3764831B1 patent drawingFigure 5~7

AI summary

An article of footwear has an upper that is direct attached with the sole. The direct attach sole has an insert, such as an airbag, that forms a portion of a sidewall. The insert is externally visible and forms at least a portion of an external sidewall of the sole. The insert is formed into the direct attach sole by having the insert or a mask temporarily joined with the insert contact a sidewall molding surface of a mold used in the direct attach operation such that the insert results in forming a visible element of the direct attached sole.