Fastener Element Inner Edge Thinning for Slide Fastener Puckering

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Solution Overview

Problem

Existing metal fastener elements for slide fasteners face issues such as reduced pliability and sliding ability when the attachment pitch is narrowed, leading to problems like puckering, poor engagement, and reduced flexibility, especially with double side elements where the thin thickness portion is exposed and the contact area with the tape is reduced.

Innovation Solution

The fastener element design includes a flat plate-shaped engaging head with protrusions and fitting spaces on both surfaces, a body portion with a bridge connecting the leg portions, and thinning portions on the inner peripheral edges to reduce the tape nipping surface area, ensuring a constant thickness of the outer side edges, which enhances pliability and prevents inclination during sliding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the attachment pitch of fastener elements is narrowed to improve density and appearance, then the aesthetic appearance and density are improved, but the pliability of the fastener stringer and sliding ability of the slider deteriorate

Engineering Contradiction:
Improvedensity of fastener elementsVSAvoidsliding ability
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The patent applies local quality by creating a thin thickness portion at a specific location (inner peripheral edge portion) of the fastener element, while maintaining normal thickness at other locations (outer side edge portions). This localized thinning reduces the tape contact area to maintain pliability without compromising the overall structural integrity and appearance of the fastener stringer.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the thin thickness portion is extended to reduce tape contact area and enhance pliability, then the pliability is improved, but the contact area with the tape is reduced leading to poor engagement

Engineering Contradiction:
ImprovepliabilityVSAvoidengagement quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The thin thickness portion is strategically positioned only at the inner peripheral edge portion where tape contact occurs, while the outer side edge portions maintain normal thickness. This localized approach ensures that the tape contact area is reduced enough to maintain pliability, while the outer portions provide sufficient engagement and structural stability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent addresses the contradiction by introducing a thickness dimension variation at a specific location. By controlling the thickness in the vertical dimension at the inner peripheral edge portion, the design achieves both reduced tape contact area for pliability and maintained outer dimension for engagement, effectively resolving the contradiction through dimensional control.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the thin thickness portion is provided on outer side edge portions to reduce contact area, then the pliability is improved, but the appearance of the slide fastener deteriorates due to exposed thin portions

Engineering Contradiction:
ImprovepliabilityVSAvoidappearance
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The thin thickness portion is located exclusively at the inner peripheral edge portion, which is not visible from the exterior. The outer side edge portions maintain uniform, normal thickness that provides a clean appearance. This spatial differentiation ensures that the functional requirement for reduced tape contact area is met without compromising the aesthetic appearance of the slide fastener.

Inventive Principle:
Principle #3Local quality

4Quantity of substance

If the attachment pitch is reduced to improve density, then the aesthetic appearance is improved, but puckering occurs due to reduced flexibility

Engineering Contradiction:
ImprovedensityVSAvoidpuckering
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

By positioning the thin thickness portion at the inner peripheral edge portion, the design maintains sufficient outer dimension to prevent tape deformation and puckering. The localized thinning provides the necessary flexibility for high-density attachment without creating the harmful puckering effect that would result from uniform thinning or thickness reduction at critical support locations.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2946683B1Fastener element and fastener stringer
Publication Date: 2017.08.23 YKK CORP
  • EP2946683B1 patent drawingFigure 1~2
  • EP2946683B1 patent drawingFigure 3
  • EP2946683B1 patent drawingFigure 4

AI summary

This fastener element (10, 20, 30, 40) is configured in such a manner that the thickness of the outer peripheral edges of a body section (12, 22, 42) and of leg sections (13, 23, 43), the thickness being measured between a first main surface and a second main surface, is constant, and a thinned section (16, 26, 36) having a smaller thickness than the outer peripheral edges is provided on at least part of the inner peripheral edges of the body section (12, 22, 42) and of the leg sections (13, 23, 43), the inner peripheral edges being located on the first main surface side and the second main surface side. As a result of this configuration, even if fastener stringers (1) are produced while the mounting pitch of fastener elements (10, 20, 30, 40) is reduced, a reduction in the flexibility and flexuousness of the fastener stringers (1) is minimized.