Fuse Switch Disconnector Fastening Mechanism

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Solution Overview

Problem

Existing fuse switch disconnectors require opening the housing and removing fuse links to unlock the upper housing part from the lower part, making installation inefficient and requiring a load-free state, which complicates assembly and maintenance.

Innovation Solution

A fuse switch disconnector design where the fastening means can be moved into a locked position without unlocking, allowing the upper housing part to be fastened to the lower part with the switch covers closed, using a bayonet-like mechanism accessible from the outside, preventing accidental unlocking and allowing only clockwise rotation for locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fastening means are arranged inside the upper housing part under the fuse links to prevent separation under load, then the locking reliability is improved, but the ease of operation deteriorates because the housing must be opened and fuse links removed before unlocking

Engineering Contradiction:
Improvelocking reliabilityVSAvoidease of unlocking
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The fastening means is divided into two functionally independent parts: a locking mechanism accessible from the front side that can be operated without opening the housing, and a securing mechanism that remains protected inside the housing under the fuse links. This segmentation allows the locking function to be accessed externally while the securing function remains protected, resolving the contradiction between accessibility and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediary element (such as a actuating lever or release mechanism) is introduced that transmits the unlocking force from the externally accessible front side to the internal fastening section. This intermediary allows operators to unlock the fastening means without opening the housing or removing fuse links, while still maintaining the secure locked position when closed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the fastening means require the housing to be opened for unlocking, then the protection against accidental unlocking is improved, but the productivity deteriorates due to the time-consuming assembly and maintenance process

Engineering Contradiction:
Improveprotection against accidental unlockingVSAvoidassembly efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The fastening system is segmented into an externally accessible locking control and an internally protected securing mechanism. This allows rapid locking/unlocking operations from the front side without requiring housing removal, significantly improving assembly and maintenance productivity while maintaining protection through the internal secure positioning of the fastening section.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the fastening means are designed with a bayonet-like mechanism accessible from the outside, then the ease of operation is improved by allowing locking without opening housing, but the device complexity increases due to the dual-position mechanism

Engineering Contradiction:
Improveease of fasteningVSAvoidfastening mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of requiring the housing to be opened to access the fastening mechanism, the design inverts the accessibility: the critical locking/unlocking function is made accessible from the outside front side, while the secure securing function remains inside. This inversion simplifies operation significantly while the internal secure positioning maintains reliability.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP2242081B1Safety load connecting block
Publication Date: 2013.12.18 EFEN
  • EP2242081B1 patent drawingFigure 1
  • EP2242081B1 patent drawingFigure 2
  • EP2242081B1 patent drawingFigure 3

AI summary

The disconnector has a fastening section (13) moved in a position in which a housing lower part is locked with a housing upper part and another position in which the housing lower part and the housing upper part are released. A fastening bolt (10) is arranged such that the fastening section is moved into the former position by exerting a force on a front side (12) or elements arranged at the front side. A mantle surface (14) of the fastening section exhibits a recess for a tool to exert the force on the fastening bolt so that the fastening bolt is moved into the latter position.