Hook-and-Locking Fastener for Dense Fabrics Without Tool Assembly

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Solution Overview

Problem

Existing two-piece fasteners damage fabrics with dense meshes and require specialized tools for assembly, limiting their application to materials like socks and not being suitable for denser materials like woven fabrics, plastic, or paper.

Innovation Solution

A fastening device with hook and locking members that allow secure interlocking without damaging the material, using pivotable locking members to enhance the locking effect and prevent detachment, allowing for use on denser materials without specialized tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a shank or pin is used to penetrate the fabric for fastening, then the fastening strength is improved, but the fabric is damaged by the hole

Engineering Contradiction:
Improvefastening strengthVSAvoidfabric damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The fastening device is divided into two separate parts: a first part with hook members that penetrate the fabric, and a second part with locking members that receive the hooks. This segmentation allows the penetrating function to be isolated to small hook members rather than large pins, minimizing fabric damage while maintaining fastening strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of having a single pin penetrate through the fabric and lock on the other side, the invention inverts the approach by having small hook members penetrate and be received by larger locking members that remain outside the fabric, reversing the traditional penetration-locking sequence and reducing fabric intrusion.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If a rivet tool or specialized tool is required for the fastening procedure, then the fastening reliability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvefastening reliabilityVSAvoidtool requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fastening device is designed to be self-assembling without external tools. The hook members are inserted through the fabric and automatically engaged by the locking members through snap-action engagement, allowing the device to fasten itself without requiring rivet tools or specialized equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces the mechanical riveting system (requiring rivet tools) with a snap-fit engagement system based on elastic deformation and geometric interlocking. The locking members use resilient arms that deflect to allow hook insertion and then snap back to lock the hooks in place, substituting complex mechanical tooling with simple elastic-mechanical engagement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If the mesh of the fabric is dense, then the fabric strength and integrity are improved, but existing fasteners cannot penetrate without causing damage

Engineering Contradiction:
Improvefabric integrityVSAvoidfastener compatibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The invention changes the size parameter of the penetrating element from large pins to small hook members, allowing penetration of dense fabric meshes. The hook members have dimensions small enough to pass through tight fabric weave without causing excessive damage, while the locking members remain large enough to provide secure engagement on the other side of the fabric.

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 design enables secure fastening of dense fabrics and other materials without damage, providing reliable interlocking and easy assembly by hand, eliminating the need for specialized tools and preventing deformation.

Implementation Method 1

the locking member is configured to pivot in a direction towards the hook member when the hook member is in engagement with the locking member and a force is applied from the hook member on the locking member

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3405063B1A fastening device and a fastening system
Publication Date: 2020.04.29 AVAITEC AB
  • EP3405063B1 patent drawingFigure 1~3b
  • EP3405063B1 patent drawingFigure 4a~5c
  • EP3405063B1 patent drawingFigure 6a~7d

AI summary

A fastening device (1; 101; 121; 131; 1 10; 210; 310; 410) comprising a first part (2) having a first engaging side (21) and a second part (3) having a second engaging side (31) and wherein the fastening device further comprises at least two sets of individual engaging members (22; 32) configured to engage with each other. Each set of engaging members comprises a hook member (22) and a locking member (32). The hook member (22) protrudes from the first engaging side (21) of the first part (2), and said hook member has an engagement side (23) from which a hook (24) protrudes. The locking member (32) is pivotably connected to the second part (3) and extends into a recess (33) provided in the second engaging side (31) of the second part (3), which recess is adapted to receive the hook member (22) for engagement with the locking member (32), and the locking member (32) is configured to pivot in a direction towards the hook member (22) when the hook member is in engagement with the locking member and a force is applied from the hook member on the locking member. Also disclosed is a fastening system comprising two fastening devices.