Cam Buffering Operation Counter for Air Circuit Breaker

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Solution Overview

Problem

Existing operation counter mechanisms for air circuit breakers are prone to damage due to excessive force generated by the closing spring, leading to defective counting functionality.

Innovation Solution

A cam-based operation counter driving apparatus that buffers and transfers the rotation force of the closing spring to a mechanical counter, using a cam with a varying radius of curvature to stabilize the force transfer and prevent component damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the closing spring directly drives the operation counter mechanism, then the counting function can be implemented, but the excessive force damages the components of the driving mechanism

Engineering Contradiction:
Improvestability of operation counterVSAvoidforce tolerance of driving mechanism components
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A cam mechanism is introduced as an intermediary between the closing spring and the operation counter driving mechanism. The cam converts the rotational force from the closing spring into controlled linear motion, buffering the excessive force and transferring it in a controlled manner to drive the operation counter without damaging its components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cam profile is designed with specific curvature variations that cushion the force transmission in advance. The varying radius of curvature in the cam profile creates a buffering effect that softens the impact of the closing spring's rotational force before it reaches the operation counter mechanism, preventing component damage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a cam with varying radius of curvature is used to buffer and transfer force, then component damage is prevented, but the device complexity increases

Engineering Contradiction:
Improveprotection of driving mechanism componentsVSAvoidcomplexity of cam structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cam mechanism serves multiple functions simultaneously: it converts rotational motion to linear motion, buffers excessive force, and drives the operation counter. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving reliable force buffering and component protection.

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

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 reliable and stable counting of the number of times the air circuit breaker contacts are closed, preventing damage to the driving mechanism and ensuring accurate operation and maintenance recognition.

Implementation Method 1

a cam coaxially connecting to the rotation shaft, and having an outer circumferential surface thereof formed with a cam profile with a varying radius of curvature, for buffering and transferring the rotation force of the rotation shaft to a mechanical counter

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP1914773B1Operation counter driving apparatus for air circuit breaker
Publication Date: 2009.12.23 LG INDUSTRIAL SYSTEMS CO LTD
  • EP1914773B1 patent drawingFigure 1
  • EP1914773B1 patent drawingFigure 2
  • EP1914773B1 patent drawingFigure 3~4

AI summary

A mechanical operation counting apparatus for counting the number of times a circuit of an air circuit breaker is closed, while performing a closing or opening operation of a switching unit, is provided with a driving apparatus to prevent an impact caused by a momentarily large force applied by a closing spring or opening spring, including: a cam (4) having an outer circumferential surface formed with a cam profile with a varying radius of curvature, a working lever having one end portion contacting the cam surface and pivoting according to a contact position thereof on the cam surface, a counter operating lever (52) having one end contacting the working lever and pivoted by engagement with the working lever, and the counter (51) being driven by the pivoting of the counter operating lever and counting and displaying the number of times the circuit of the air circuit breaker is closed.