Molded Case Circuit Breaker Trip Bar With Modular Current Adjustment

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Solution Overview

Problem

Existing molded case circuit breakers with adjustable disarming bars require complex manufacturing adaptations, lacking interchangeability with fixed adjustment devices, and are not cost-effective.

Innovation Solution

A molded case circuit breaker design featuring a fixed disarming bar with a variable adjustment mechanism, comprising a variable adjustment disarming bar that can be modularly added, using a concave surface and an eccentric current adjustment dial to modify the distance between bimetal elements, allowing for adjustable current range without additional fastening components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If adjustable disarming bars are implemented in molded case circuit breakers, then adaptability to different current ranges is improved, but device complexity increases due to additional adjustment parts

Engineering Contradiction:
Improveadjustability to current rangeVSAvoidconstruction complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The disarming bar is divided into a fixed portion and a variable adjustment portion that can be independently positioned. The fixed portion provides structural stability while the variable portion allows adjustment to different current ranges through discrete positioning options, reducing overall complexity compared to fully adjustable designs

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fixed adjustment disarming bar design serves as a universal base structure that can accommodate different current ranges by simply changing the variable adjustment portion positioning, eliminating the need for multiple different disarming bar designs for different current ratings

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If adjustable disarming bars with multiple parts are used, then adaptability is improved, but ease of manufacture deteriorates due to additional assembly steps

Engineering Contradiction:
Improveadjustability to current rangeVSAvoidmanufacturing simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The variable adjustment portion is pre-positioned and pre-assembled to specific positions on the fixed disarming bar during manufacturing. This preliminary positioning allows the circuit breaker to be produced in different current range configurations at the manufacturing stage, simplifying field assembly and reducing the number of assembly steps required during installation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The disarming bar design incorporates self-aligning features and self-locking mechanisms that allow the variable adjustment portion to automatically position itself correctly on the fixed portion without requiring complex external alignment tools or multiple fastening operations during assembly

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If conventional adjustable disarming bars are implemented, then adaptability is improved, but cost-effectiveness deteriorates due to additional components

Engineering Contradiction:
Improveadjustability to current rangeVSAvoidcost of construction
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adjustment mechanism is extracted as a separate variable portion that can be independently manufactured and then attached to the fixed disarming bar. This extraction allows for standardized production of the fixed portion at low cost while the variable portion can be produced in different configurations as needed, reducing overall component costs compared to fully integrated adjustable designs

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The variable adjustment portion is designed to nest within or attach to the fixed disarming bar structure, sharing common mounting surfaces and alignment features. This nesting approach allows both portions to utilize the same structural space and manufacturing fixtures, reducing total material usage and manufacturing cost while maintaining adjustability functionality

Inventive Principle:
Principle #7Nested doll (Nesting)

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 a simpler, cost-effective construction of adjustable circuit breakers by allowing modular integration of variable adjustment, maintaining operational reliability and safety without complex manufacturing modifications.

Implementation Method 1

the temperature of the electrical path operates by being related to a predetermined time delay within a range where the temperature of the electrical path does not exceed the permissible temperature to be regulated

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the bimetal starts to bend before the opening/closing mechanism can be operated by the rotation of an adjustable disarming bar

Methodology Applied
Scientific EffectBimetallic strip: Bi-Metallic Strip

Data Source

PatentEP4576153A1Molded case circuit breaker and assembly method
Publication Date: 2025.06.25 WEG DRIVES & CONTROLS AUTOMAC O LTDA
  • EP4576153A1 patent drawingFigure 1~2
  • EP4576153A1 patent drawingFigure 3~4
  • EP4576153A1 patent drawingFigure 5~7

AI summary

The present invention describes a molded case circuit breaker, comprising: a trigger device provided with at least one rotating bar; a fixed adjustment bar arranged, in a movable and rotatable manner, on said rotating bar of the trigger device and in the direction of movement of an operating handle; a plurality of bimetals provided, in their upper portion, with transverse distance adjustment elements; wherein said circuit breaker further comprises a variable adjustment disarming bar disposed upon said fixed disarming bar, said variable adjustment disarming bar having concave surfaces; wherein the concave surfaces are arranged, respectively, on the flat contact surfaces; wherein the concave surfaces each comprise an inclined portion projecting frontally to the upper portion of a plurality of bimetals; and wherein the variable adjustment disarming bar extends along the length of the fixed disarming bar; and a circuit test button comprising a first drive bar physically associated with said fixed disarming bar and a second actuation bar physically associated with said variable adjustment disarming bar.