Lace Spool Fastening Mechanism With Pawl-Controlled Release

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Solution Overview

Problem

Existing fastening devices for laces, such as buckles, face issues with security due to easy loosening under external forces or vibrations, lack of incremental release functionality, and complex structures that increase manufacturing costs and assembly difficulties.

Innovation Solution

A fastening device with a case, spool, and knob featuring engaging teeth and a pawl arm mechanism that allows incremental release by temporarily offsetting friction as the lace is tensioned or released, utilizing a combination of pawl arms and abutting members to manage lace tension and prevent full release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple spring-based fastening mechanism is used, then the structure is simple and manufacturing cost is low, but the lace is easily released due to vibrations or external force

Engineering Contradiction:
Improvestructure simplicityVSAvoidsecuring force
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The fastening mechanism is segmented into multiple independent components: a housing with engaging teeth, a spool, a pawl arm with abutting member, and a knob. This segmentation allows each component to perform a specific function while working together to achieve reliable incremental release of the lace.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If a buckle with interference between components is used, then the cord can be received inside and adjusted, but the structure becomes complex increasing manufacturing cost and assembly difficulty

Engineering Contradiction:
Improvecord adjustment capabilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of cord adjustment from complex buckle mechanisms and implements it through a simplified spool-pawl system. The lace is wound around the spool which can rotate to adjust length, while the pawl arm with abutting member provides a simpler alternative to complex interference-based locking mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If a pawl arm mechanism with abutting member is used, then incremental release function is achieved, but the device complexity increases

Engineering Contradiction:
Improveincremental release functionVSAvoidengaging unit complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The abutting member is designed to be deflectable by the lace tension itself. When the lace is pulled, the tension automatically deflects the abutting member to offset friction and allow incremental release, without requiring additional actuators or complex control mechanisms. The system uses the lace's own tension to facilitate its release.

Inventive Principle:
Principle #25Self-service

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 device provides secure and incremental lace tensioning and release, enhancing user convenience while reducing manufacturing complexity and assembly challenges, maintaining tension without full release until desired.

Implementation Method 1

the at least one abutting member is deflected by a tension of the lace to offset a friction temporarily

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the at least one abutting member is deflected by a tension of the lace

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

a tension of the lace to offset a friction temporarily

Methodology Applied
Scientific EffectTension: Tension

Data Source

PatentEP4321050A1Fastening device
Publication Date: 2024.02.14 CHEN CHIN CHU
  • EP4321050A1 patent drawingFigure 1
  • EP4321050A1 patent drawingFigure 2
  • EP4321050A1 patent drawingFigure 3

AI summary

A fastening device includes a case including a plurality of engaging teeth, a spool disposed at the case and configured for a lace to be wound therearound, a knob covering the case, and an engaging unit disposed at the case and coupled to the spool. The engaging unit includes at least one pawl arm selectively coupled to at least one of the engaging teeth, and at least one abutting member. As the knob is rotated in a tensioning direction, the engaging unit is rotated and the pawl arm is disengaged from the engaging teeth to allow the spool to tension the lace. As the knob is rotated in a releasing direction to allow the pawl arm to disengage from the engaging teeth, the abutting member is deflected by a tension of the lace to offset a friction temporarily, thereby allowing the lace to be incrementally released.