S-Shaped Flexible Conductive Elements for Circuit Breakers

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Solution Overview

Problem

Existing conductor assemblies in low-voltage circuit breakers face issues with flexibility and compactness due to the expansion of wire rope shunts and the space-consuming V-shape of layered ribbon shunts, which hinder their ability to accommodate compound motion and occupy minimal space within the housing.

Innovation Solution

The use of S-shaped flexible conductive elements made from layered conductive ribbon, with strategically designed bends and retention mechanisms, allows for a compact and flexible conductor assembly that can withstand compound motion while minimizing space usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If wire rope shunts are used, then flexibility is provided, but the shunt body expands outward and occupies more than the width of the finger, interfering with adjacent structures

Engineering Contradiction:
ImproveflexibilityVSAvoidwidth occupation
Core Design Contradiction:
Adaptability or versatilityVSArea of moving object

Solution Approach 1:

The patent replaces wire rope shunts with layered ribbon shunts that function as flexible thin films. These ribbons provide the necessary flexibility for compound motion while maintaining a compact width that fits within the finger structure, eliminating the expansion problem of wire ropes.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent introduces curved configurations including U-shaped and S-shaped bends in the ribbon shunts. These curved geometries enable the shunts to accommodate compound motion of the fingers while maintaining a compact form factor that does not interfere with adjacent structures.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If wire rope shunts are used, then flexibility is provided, but the ropes bunch together during short circuit events, inhibiting the flexibility of the assembly

Engineering Contradiction:
ImproveflexibilityVSAvoidstructural integrity
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The layered ribbon structure maintains its integrity during short circuit events unlike wire ropes that bunch together. The ribbon's flat, layered construction prevents bunching while maintaining flexibility through controlled bending in U-shaped and S-shaped configurations.

Inventive Principle:
Principle #30Flexible shells and thin films

3Volume of moving object

If layered ribbon shunts are used, then a compact form is achieved, but the V-shape creates a single sharp bend that concentrates stress and consumes substantial space

Engineering Contradiction:
Improvespace consumptionVSAvoidstress concentration
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The patent replaces the V-shape with U-shaped and S-shaped curved configurations. These gradual curves eliminate sharp bends and stress concentrations while maintaining compact space usage. The multi-directional bends of the S-shape specifically address compound motion requirements.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent divides the ribbon shunt into multiple segments with bends in different directions (U-shaped bends, S-shaped bends). This segmentation distributes stress across multiple gentle curves rather than concentrating it in a single sharp V-shaped bend.

Inventive Principle:
Principle #1Segmentation

4Area of moving object

If layered ribbon shunts are used, then space is reduced, but the V-shape consumes a substantial amount of valuable space within the molded housing

Engineering Contradiction:
Improvespace efficiencyVSAvoidhousing space consumption
Core Design Contradiction:
Area of moving objectVSVolume of moving object

Solution Approach 1:

The U-shaped and S-shaped curved configurations are more space-efficient than V-shapes. The curves follow a more compact path that reduces the overall envelope space required within the molded housing while still accommodating the necessary motion range.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 S-shaped flexible conductive elements provide robust, compact, and economical solutions that accommodate the full range of motion in circuit breakers, optimizing space usage and reducing stress concentrations within the housing.

Implementation Method 1

S-shaped flexible conductive elements made from layered conductive ribbon

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

retention mechanisms

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP1912229B1Electrical switching apparatus, and conductor assembly, and independent flexible conductive elements therefor
Publication Date: 2015.11.18 EATON CORP
  • EP1912229B1 patent drawingFigure 1
  • EP1912229B1 patent drawingFigure 2
  • EP1912229B1 patent drawingFigure 3

AI summary

A flexible conductive element is provided for the conductor assembly of an electrical switching apparatus. The conductor assembly includes a load conductor, a movable contact assembly including a number of movable contact arms, movable electrical contacts mounted on the movable contact arms, and a plurality of flexible conductive elements. Each flexible conductive element includes a first end electrically connected to the load conductor, a second end electrically connected to a corresponding one of the movable contact arms of the movable contact assembly, and a plurality of bends between the first end and the second end. A first one of the bends is in a first direction and at least a second one of the bends is in a second direction which is generally opposite the first direction, in order that the flexible element is generally S-shaped. A conductor assembly and an electrical switching apparatus are also disclosed.