Strap Coiling Assembly for One-Handed Tightness Adjustment

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Solution Overview

Problem

Users, especially beginners or those with difficulty using two hands, face complexity and time-consuming operations when adjusting strap tightness, as existing methods require manual tying and dual-hand manipulation.

Innovation Solution

A strap adjustment apparatus comprising a driving part, coiling part, and adjusting part, where the driving part drives the coiling part to rotate, utilizing spring sheets and annular racks to wind or unwind the strap, allowing one-handed adjustment of tightness without tying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual tying and dual-hand manipulation are used to adjust strap tightness, then the strap can be securely fixed, but the operation becomes complex and time-consuming

Engineering Contradiction:
Improvestrap fixation securityVSAvoidoperation complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The strap adjustment apparatus enables self-adjustment through a mechanical winding mechanism. The user simply needs to wind the strap around the coiling column, and the ratchet mechanism automatically maintains the adjusted tightness without requiring manual tying or complex dual-hand operations. The system serves itself by using the winding action to both adjust and lock the tightness.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The ratchet mechanism acts as an intermediary between the winding action and the strap tightness maintenance. It translates the winding motion into a one-way locking mechanism that prevents unwinding, thereby securing the strap at the desired tightness level without requiring the user to perform complex tying operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If manual tying operations are performed to fix the strap, then secure attachment is achieved, but time is significantly consumed

Engineering Contradiction:
Improvestrap attachment securityVSAvoidadjustment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The apparatus performs the attachment function automatically through the winding and ratchet mechanism. Once the strap is wound around the coiling column, the ratchet mechanism automatically locks the position, eliminating the need for time-consuming manual tying operations while maintaining secure attachment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the time-consuming tying operation from the adjustment process and replaces it with a simple winding motion. The complex knot-tying function is removed and substituted with a mechanical winding and locking system that achieves the same secure attachment much faster.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If dual-hand manipulation is required for strap adjustment, then proper tensioning can be achieved, but accessibility is reduced for users with dexterity challenges

Engineering Contradiction:
Improvetensioning accuracyVSAvoiduser accessibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The apparatus performs the tensioning function through a single-handed winding operation. The mechanical advantage provided by the coiling column and ratchet mechanism allows one hand to achieve proper tensioning that previously required dual-hand manipulation, thereby improving accessibility for users with dexterity challenges.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The ratchet mechanism provides dynamic adaptation during the winding process. It allows free winding in the tightening direction while automatically preventing unwinding, enabling users with limited dexterity to achieve and maintain proper tension with one hand without requiring coordinated dual-hand manipulation.

Inventive Principle:
Principle #15Dynamics

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

Enables simple, one-handed adjustment of strap tightness, reducing operational complexity and time, particularly benefiting users with dexterity challenges, while maintaining a preset level of tightness.

Implementation Method 1

the coiling part is provided thereon with a coiling column and spring sheets

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the driving part is configured to drive the coiling part to rotate in an axial direction; the coiling part is provided thereon with a coiling column and spring sheets, and the coiling column is provided thereon with a fixing portion configured to fix a strap; the adjusting part is provided thereon with annular racks cooperating with the spring sheets

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP3556239B1Strap adjustment apparatus and assembly
Publication Date: 2022.01.12 SHENZHEN FITGO TECH CO LTD
  • EP3556239B1 patent drawingFigure 1
  • EP3556239B1 patent drawingFigure 2
  • EP3556239B1 patent drawingFigure 3~4

AI summary

A belt adjustment apparatus and assembly, wherein the belt adjustment apparatus (42) includes a driving part (1), a coiling part (2), and an adjusting part (3); the driving part (1), the coiling part (2), and the adjusting part (3) are coaxially provided; the driving part (1) and the coiling part (2) are both movably connected with the adjusting part (3); the driving part (1) is configured to drive the coiling part (2) to rotate in an axial direction; the coiling part (2) is provided thereon with a coiling column (4) and spring sheets (5), and the coiling column (4) is provided thereon with a fixing portion (6) configured to fix a strap; the adjusting part (3) is provided thereon with annular racks (7) cooperating with the spring sheets (5). When fixing through the strap, with the above belt adjustment apparatus (42), the user can avoid a tying operation, and can complete the adjustment of a level of tightness merely by rotating and operating the driving part (1) with one hand, which operation is simple, and saves time, especially facilitating use of beginners or users having difficulty in using two hands.