Secondary Disconnect Assembly Error-Proofing Features

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Solution Overview

Problem

Existing electrical switching apparatus, such as circuit breakers, lack effective error-proofing features to ensure correct orientation and alignment of accessory plugs, leading to potential damage and improper electrical connections.

Innovation Solution

A secondary disconnect assembly with error-proofing features, including elongated ribs and slots on terminal blocks and accessory plugs, and alignment posts and grooves on the cradle assembly, which prevent incorrect insertion and ensure proper orientation, alignment, and secure locking of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If accessory plugs are made removable for customer customization, then ease of operation and adaptability are improved, but the risk of improper insertion and damage increases

Engineering Contradiction:
Improveease of customizationVSAvoidrisk of improper insertion
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies asymmetry by providing ribs on the terminal block and corresponding slots on the accessory plug that are oriented in specific directions. These asymmetric features allow the accessory plug to be inserted only in the correct orientation, preventing improper insertion while maintaining ease of customization. The ribs and slots are positioned such that they guide the plug into proper alignment during insertion.

Inventive Principle:
Principle #4Asymmetry

2Adaptability or versatility

If secondary disconnect assembly components are made easily removable, then adaptability and ease of manufacture are improved, but manufacturing precision and alignment accuracy become more difficult to maintain

Engineering Contradiction:
Improveease of reconfigurationVSAvoidalignment accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by incorporating alignment posts and grooves that automatically guide and position the terminal block and accessory plug during assembly. These features are pre-formed on the components themselves, ensuring that when the accessory plug is inserted, it automatically aligns with the correct orientation and position, maintaining manufacturing precision while allowing easy reconfiguration.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If error-proofing features are added to prevent improper insertion, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprevention of improper connectionVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into the error-proofing features. The ribs and slots serve both as mechanical guides for alignment and as prevention mechanisms against improper insertion. The alignment posts and grooves simultaneously provide positioning and orientation control. By combining these functions into integrated features rather than separate mechanisms, the patent improves reliability while minimizing the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3278345B1Electrical switching apparatus and secondary disconnect assembly with error-proofing features therefor
Publication Date: 2020.04.29 EATON INTELLIGENT POWER LTD
  • EP3278345B1 patent drawingFigure 1
  • EP3278345B1 patent drawingFigure 2
  • EP3278345B1 patent drawingFigure 3~4

AI summary

A secondary disconnect assembly (100) is for electrically connecting and disconnecting accessories to an electrical switching apparatus (2), such as a power circuit breaker (2). The secondary disconnect assembly (100) includes a terminal block assembly (200) comprising a mounting member (212), at least one terminal block (400) removably mounted on the mounting member (212), and at least one accessory plug (500) structured to be removably inserted into the terminal block (400) to be electrically connected to the terminal block (400). The terminal block (400) and the accessory plug (500) each include a plurality of error-proofing features (420,422;520,522). The error-proofing features (420,422;520,522) prohibit insertion of the accessory plug (500) into the terminal block (400) unless the accessory plug (500) is correctly disposed in a predetermined orientation.