Strap Buckle Assembly with Arc Spring for One-Handed Adjustment

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Solution Overview

Problem

Existing strap buckle assemblies are inconvenient and time-consuming to adjust, requiring two hands to release the strap, especially when used in child carriers, and the process of length adjustment is complex and force-exerting.

Innovation Solution

A strap buckle assembly with a movable arc-shaped spring mechanism that allows for variable friction adjustment by changing the bending radius, enabling one-handed operation and easy length adjustment without the need to lift the buckle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional strap buckle assembly with two bars is used to clamp the strap, then the strap is securely clamped through friction force, but the adjustment of strap length becomes complicated and time-consuming requiring two hands

Engineering Contradiction:
Improveclamping reliabilityVSAvoidoperation convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The buckle is divided into a first part and a second part that can move relative to each other. The first part contains the clamping mechanism while the second part can be independently actuated, allowing one-handed operation to release the strap while maintaining secure clamping through the friction force between the two parts

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second part is made movable relative to the first part, enabling dynamic adjustment of the clamping force. By moving the second part, the friction force between the parts can be increased or decreased, allowing easy release of the strap by a single hand while maintaining reliable clamping when engaged

Inventive Principle:
Principle #15Dynamics

2Length of moving object

If the strap length is increased by pulling the free end into the buckle, then the strap length between the maze and first end portion is increased, but the adjustment procedure becomes complicated and force-exerting

Engineering Contradiction:
Improvestrap lengthVSAvoidadjustment procedure complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The buckle is segmented into movable first and second parts, creating a modular structure where the second part can be independently actuated. This segmentation simplifies the adjustment procedure by allowing the user to manipulate only the second part for length adjustment rather than performing complex multi-step operations on the entire buckle assembly

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable connection between the first and second parts enables dynamic length adjustment. The user can easily pull or push the second part relative to the first part to adjust the strap length, making the adjustment process simpler and requiring less force compared to traditional fixed buckle designs

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 one-handed operation and easy length adjustment of the strap, improving convenience and safety by allowing the strap to be securely fastened or released without the need for two hands, making it suitable for child carriers.

Implementation Method 1

an operating mechanism having a spring. The spring is arc-shaped, has a variable bending radius and comprises a first end connected to the first part of the strap buckle assembly as well as a second end connected to the second part of the strap buckle assembly

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The operating mechanism is configured to vary the bending radius of the spring, by moving the pivoting bar such that said first and second end of the spring are displaceable with respect to each other

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 3

a friction force can be realized between the first and second part for clamping a strap

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2832249B1Strap buckle assembly for clamping a strap
Publication Date: 2018.05.30 THULE IP AB
  • EP2832249B1 patent drawingFigure 1
  • EP2832249B1 patent drawingFigure 2a
  • EP2832249B1 patent drawingFigure 2b

AI summary

A strap buckle assembly (1) for clamping a strap (2) is disclosed which comprises a first and a second part (3, 4) for clamping the strap (2) in-between, wherein the first and the second part (3, 4) are relatively movable to each other, and an operating mechanism (5) having a spring (5b), wherein the spring (5b) is arc-shaped having a variable bending radius (R) and comprises a first end (5c) connected to the first part (3) as well as a second end (5d) connected to the second part (4), and wherein the operating mechanism (5) is configured to vary the bending radius (R) of the spring (5b) such that said first and second end (5c, 5d) of the spring (5b) are displaceable with respect to each other between a clamping position and an adjusting position.