Switching Device Lever Head Contour Safety Interlock

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Solution Overview

Problem

Existing electrical circuit breakers lack a mechanism to ensure safe access to the interior housing, as the housing cover can be opened regardless of the switching lever position, posing a risk of damage or injury when the circuit is still energized.

Innovation Solution

A switching device with a coordinated opening and outer contour of the switching opening and lever head, allowing the housing cover to be opened only when the switching lever is in the off position, preventing direct access to the interior when the lever is on and ensuring de-energization before maintenance or upgrades.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the housing cover is made openable for access to the interior, then maintenance and upgrades become possible, but access can be obtained even when the circuit is energized creating safety risks

Engineering Contradiction:
Improveaccess for maintenance and upgradesVSAvoidrisk of damage or injury from energized circuit
Core Design Contradiction:
Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The switching lever head must be moved to the off position before the housing cover can be opened. This preliminary action ensures the circuit is de-energized before access to the interior is permitted, eliminating the safety risk while maintaining ease of repair.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The switching lever head acts as an intermediary element between the housing cover and the interior space. Through its coordinated contours with the switching opening, it mediates the opening process by requiring the lever to be in the off position, thus controlling access based on circuit state.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the housing cover can be opened freely, then access to the interior is always possible, but this creates safety hazards when the switching unit is still energized

Engineering Contradiction:
Improveaccess to interiorVSAvoidsafety during operation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system requires the switching lever to be moved to the off position as a preliminary action before the housing cover can be opened. This ensures that access to the interior is only possible when the switching unit is de-energized, maintaining both ease of operation and reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The coordinated contours of the switching lever head and switching opening create a self-locking mechanism. The system automatically prevents opening when the lever is in the on position through the geometric coordination, without requiring additional control systems or interventions.

Inventive Principle:
Principle #25Self-service

3Device complexity

If the switching lever head allows free movement through the switching opening, then operation is simple, but the housing cover can be opened regardless of circuit state

Engineering Contradiction:
Improvesimple lever operationVSAvoiduncontrolled access to energized interior
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The coordinated contours between the switching lever head and switching opening create an asymmetric geometric relationship. The opening contour is specifically shaped to allow the lever head to pass through only when positioned in the off state, while blocking passage in the on state, thus controlling access without complicating the lever operation.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The geometric coordination requires the switching lever head to be in the off position as a preliminary condition before it can move through the switching opening and allow the housing cover to open. This maintains simple operation while preventing uncontrolled access.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2634785B1Switching device
Publication Date: 2016.10.19 SIEMENS AG
  • EP2634785B1 patent drawingFigure 1
  • EP2634785B1 patent drawingFigure 2~3
  • EP2634785B1 patent drawingFigure 4~5

AI summary

The device (10) has a switching unit arranged inside a housing (20) that comprises an openable housing cover (22). A control lever head (42) of a control lever (40) for switching the switching unit projects through a switching opening (24) and is movable between an on-position (E) and an off-position. An opening contour of the opening and an outer contour of the control lever head are aligned with one another such that the control lever head prevents and permits a movement of the cover via the head in the on-position and the off-position, respectively. An independent claim is also included for a method for opening a housing cover of a switching device.