Air Circuit Breaker Breaking Spring Axial Assembly

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Solution Overview

Problem

The existing air circuit breakers face challenges in achieving a compact structure and simplifying the installation process of the breaking spring due to the closed loop shape of the first fixing part, which requires additional space and complicates the assembly process.

Innovation Solution

The breaking spring design includes a first fixing part with a hook-like shape and a fixing hole with an outward entrance, allowing the connection shaft to be inserted without needing additional space, and a tool with a hook part to simplify the installation process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the first fixing part is designed as a closed loop shape, then the breaking spring can be securely fixed, but additional space is required for assembly and the assembly process becomes complicated

Engineering Contradiction:
Improvefixing securityVSAvoidassembly process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The first fixing part is divided into two functional sections: a hook-like shape for securing the breaking spring and a separate fixing hole with an outward entrance for tool access. This segmentation allows the breaking spring to be fixed securely while enabling simple assembly through the outward-opening entrance without requiring complex axial movements or additional space.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the first fixing part is designed as a closed loop shape, then the breaking spring can be securely fixed, but additional space is required at the end portion of the connection shaft

Engineering Contradiction:
Improvefixing securityVSAvoidspace at connection shaft end
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The fixing structure is segmented into a hook-like shape for secure attachment and a separate fixing hole with outward entrance. This allows the breaking spring to be securely fixed while the tool accesses through the outward opening, eliminating the need for additional axial space at the connection shaft end that would be required for a closed loop design.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the fixing hole is designed with an outward entrance, then the assembly tool can access easily, but the structure becomes less symmetric

Engineering Contradiction:
Improvetool accessibilityVSAvoidstructural symmetry
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The fixing hole is deliberately designed with an asymmetric outward opening rather than a symmetric closed loop. This asymmetric design provides easy access for the assembly tool while the hook-like shape maintains the structural integrity and securing function. The asymmetry is functional rather than arbitrary, optimizing both assembly ease and structural performance.

Inventive Principle:
Principle #4Asymmetry

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

This design enables a compact structure, simplifies the assembly tool, reduces assembly time, and lowers fabrication costs by eliminating the need for axial movement of the breaking spring during installation.

Implementation Method 1

a coil-shaped elastic member (57) interposed between the first and second fixing parts (51, 55)... the breaking spring (37) provides an elastic force for returning the movable contactor (38) to its initial state

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a closing spring (25) which has one end connected with a lower end portion of the driving lever (24) and the other end supported by the frame (9), and is compressed due to the rotation of the driving lever according to the rotation of the cam (22) to store elastic energy

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1914772B1Air circuit breaker, breaking spring of air circuit breaker and connection method thereof
Publication Date: 2010.06.02 LG INDUSTRIAL SYSTEMS CO LTD
  • EP1914772B1 patent drawingFigure 1
  • EP1914772B1 patent drawingFigure 2
  • EP1914772B1 patent drawingFigure 3

AI summary

An air circuit breaker, a breaking spring of the air circuit breaker, and its connection method are disclosed. The air circuit breaker includes: a cam (22); a driving lever (24) connected with the cam and rotated; a closing spring (25) compressed by the driving lever (24); a plurality of links (29,34,35) that transfer a driving force generated when the closing spring is stretched; a switching shaft (3) connected with one or the links by a connection shaft (36) and rotated according to movement of the link; and a breaking spring (37) having a fixing hole (52,72) with one side opened at one end portion (51,70) thereof, so as to be fixed to the connection shaft (36) perpendicularly in an axial line direction of the connection shaft. A space for assembling does not need to be formed at an end portion of the connection shaft, obtaining a compact structure. In addition, a tool can be simplified, an installation can be facilitated, an assembling time can be shortened, and a fabrication cost can be reduced.