Fastener Element Notch and Bulging Design for Slip Strength

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Solution Overview

Problem

Conventional methods for manufacturing metallic fasteners with protruded portions for enhanced slip strength face challenges in forming protrusions with sufficient bulging height, especially when using wire materials with a Y-shaped cross section, and these protrusions can be compromised during polishing.

Innovation Solution

A metallic fastener element with a tape holding portion featuring notch portions concaved on its surfaces and bulging portions adjacent to the notch bottoms, which are formed during press molding, allowing for increased bulging height and stability, and a manufacturing device that includes a pressure pad with protruded pressing parts to shape the tape holding portion effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If protruded portions are formed on the tape holding portion to enhance slip strength, then slip strength is improved, but the protrusions can be compromised during polishing and the bulging height is difficult to secure

Engineering Contradiction:
Improveslip strengthVSAvoidprotrusion stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent forms the notch portions and bulging portions simultaneously during the press molding process before polishing. By creating the engagement features in advance during forming, the protrusions are established as integral parts of the structure that can withstand subsequent polishing operations without being compromised.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent combines the formation of notch portions and bulging portions into a single press molding operation. The pressure pad with protruded pressing parts creates both features simultaneously during element formation, integrating multiple functions into one manufacturing step and ensuring consistent geometry that maintains stability through polishing.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If conventional press molding is used to form protruded portions, then manufacturing is simplified, but sufficient bulging height cannot be achieved

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidbulging height
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent modifies the pressure pad to include protruded pressing parts at specific locations corresponding to where notch and bulging portions should form. This localized modification to the tooling allows precise control over the geometry and dimensions of the engagement features, achieving sufficient bulging height only where needed while maintaining simple overall manufacturing.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If Y-shaped wire material is used for cost-effective manufacturing, then manufacturing cost is reduced, but forming protrusions with sufficient bulging height becomes extremely difficult

Engineering Contradiction:
Improvemanufacturing costVSAvoidprotrusion geometry
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the geometric parameters of the press molding process by introducing protruded pressing parts on the pressure pad. This modification allows the Y-shaped wire material to be effectively utilized while achieving the required protrusion geometry, as the localized pressure distribution from the protruded pressing parts creates the necessary bulging height and notch features during forming.

Inventive Principle:
Principle #35Parameter changes

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 fasteners with enhanced slip and pull-out strength by allowing deep engagement of the fastener tape into the notch and bulging portions, maintaining protrusion size even after polishing, and facilitating cost-effective manufacturing using a Y-shaped wire material.

Implementation Method 1

locally pressing the tape holding portion of the element component along the element thickness direction to be plastically deformed

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3453276B1Fastener element, manufacturing device for fastener element, and manufacturing method for fastener element
Publication Date: 2020.10.28 YKK CORP
  • EP3453276B1 patent drawingFigure 1
  • EP3453276B1 patent drawingFigure 2~4
  • EP3453276B1 patent drawingFigure 5~6

AI summary

This fastener element (10) has a coupling head portion (11) and a tape holding portion (16) provided with a body portion (17), a first leg portion (18a), and a second leg portion (18b). The tape holding portion (16) has at least one notch portion (21) that is open on a tape holding surface (19), and a bulging portion (22) that bulges out adjacently with respect to a bottom surface (21a) in the element thickness direction of the notch portion (21). Such a fastener element (10) can be easily manufactured from a Y-shaped wire material (50). Furthermore, the slip strength and pull-out strength of the fastener element (10) can be increased by implanting the fastener element (10) in a fastener tape (3).