Shoe Upper Cutting Pattern Correction for Thermoforming

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Solution Overview

Problem

When manufacturing shoe uppers, simply designing cutting patterns based on shoe last shapes can result in portions that do not sufficiently conform to the shoe last during thermoforming, leading to inadequate fit and comfort.

Innovation Solution

A design support apparatus that calculates a cutting pattern for a heat-shrinkable sheet by considering shrinkage directions and coefficients, incorporating corrections to ensure the upper conforms accurately to the shoe last shape, using a processor to simulate and adjust the pattern based on foot shape data and material properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a cutting pattern is designed simply based on the shape of the shoe last, then the design process is simple and quick, but the upper does not sufficiently conform to the shape of the shoe last after thermoforming

Engineering Contradiction:

Improveconformance to shoe last shapeVSAvoiddesign process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention applies preliminary action by pre-calculating and incorporating the shrinkage amount into the cutting pattern design before the actual cutting and thermoforming processes. The processor computes the shrinkage amount based on material properties and thermoforming conditions, then adjusts the cutting pattern accordingly in advance, so that the upper automatically conforms to the shoe last shape after shrinkage occurs during thermoforming.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention utilizes parameter changes by modifying the cutting pattern dimensions based on computed shrinkage parameters. The processor adjusts the cutting pattern size and shape parameters according to the predicted shrinkage behavior of the material during thermoforming, transforming the static cutting pattern into a dynamic design that accounts for material transformation.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the cutting pattern is corrected to account for shrinkage, then the upper conforms better to the shoe last, but the calculation and design process becomes more complex

Engineering Contradiction:

Improvefit accuracyVSAvoiddesign process ease

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention applies self-service by enabling the system to automatically compute shrinkage amounts and generate corrected cutting patterns without requiring manual intervention or expert knowledge. The processor autonomously performs the calculations based on input parameters about material properties and thermoforming conditions, making the complex correction process as easy as inputting basic material data.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention replaces manual design and adjustment processes with automated computational processing. Instead of relying on experienced designers to manually adjust cutting patterns based on empirical knowledge, the system uses a processor to automatically calculate shrinkage and generate corrected patterns, substituting mechanical/designer judgment with computational algorithms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If shrinkage is not considered in the cutting pattern, then the manufacturing process is simpler, but the thermoforming result is inadequate

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidthermoforming quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

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 solution enables the production of shoe uppers that fit more accurately to the shoe last, enhancing user comfort and fit by accounting for material shrinkage and thickness variations, thereby improving the thermoforming process.

Implementation Method 1

a cloth that forms an upper is overlaid on a shoe last, to thereby form the upper that conforms to the shape of the shoe last... thermoforming a cloth that forms an upper

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP4035551B1Design support apparatus, design method and upper producing system

Publication Date: 2023.10.04 ASICS CORP

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AI summary

A design support apparatus (100) includes: an input unit (106) that receives shoe last data (1); a processor (102) (computing unit) that computes a cutting pattern (30) of a sheet based on the shoe last data (1) received by the input unit (106); and an output unit (108) that outputs the cutting pattern (30) of the sheet computed by the processor (102). The processor (102) calculates an amount of correction in consideration of a shrinkage direction and a shrinkage coefficient of the sheet, and calculates the cutting pattern (30) of the sheet by developing, on a plane, three-dimensional shape data (2) that conforms to a dimension of the shoe last data (1), to thereby obtain a shape pattern (3) of an upper, and incorporating the calculated amount of correction into the shape pattern (3) of the upper.