Retrofittable Snap-Action Switch Lock for Circuit Breakers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing low-voltage protection devices, such as circuit breakers, lack a simple and efficient method for retrofitting quick switching functionality, which is necessary for handling larger nominal currents without increasing complexity or storage costs.

Innovation Solution

A retrofittable switch lock mechanism with a blocking part and return spring, where the locking part is Z-shaped and snaps onto a bearing, and the return spring is J-shaped, allowing for easy and secure mounting, enabling abrupt switching on without additional space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a retrofittable device for instantaneous switching is implemented, then quick switching functionality is achieved for handling larger nominal currents, but device complexity increases

Engineering Contradiction:
Improvequick switching functionalityVSAvoidswitching lock assembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The switching lock assembly is divided into a basic assembly and a retrofittable instantaneous switching device. The retrofittable device comprises a blocking part with a tongue element and a return spring, which can be added to the basic assembly to enable instantaneous switching functionality. This segmentation allows the same basic assembly to serve both standard and quick-switching applications.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blocking part is designed with a pre-formed tongue element that engages with the roller at a specific position. The return spring is pre-positioned to apply force to the tongue element. When the handle is rotated, the tongue element automatically engages with the roller at the predetermined position, enabling instantaneous switching without requiring complex control mechanisms.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If different switch lock assemblies are manufactured for standard and quick switching applications, then specific functionality is optimized, but storage and handling costs increase

Engineering Contradiction:
Improveswitching functionality optimizationVSAvoidvariety of assemblies to store
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The basic switching lock assembly is designed to be universal and can function in both standard switching and instantaneous switching applications. By adding the retrofittable blocking part and return spring, the same basic assembly achieves quick switching capability. This eliminates the need to manufacture and store separate assemblies for different applications, reducing inventory complexity and storage costs.

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

3Manufacturing precision

If manual assembly of pre-assembled key switch assemblies is performed, then assembly precision is maintained, but productivity decreases

Engineering Contradiction:
Improveassembly precisionVSAvoidassembly speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The retrofittable device incorporates a dynamic engagement mechanism where the tongue element of the blocking part automatically engages with the roller during handle rotation. The return spring provides dynamic force to ensure proper engagement. This dynamic design allows for simpler, faster assembly processes while maintaining precision through the self-aligning nature of the engagement mechanism.

Inventive Principle:
Principle #15Dynamics

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

This solution reduces the variability of pre-assembled switch lock assemblies, lowers storage and handling costs, and simplifies the assembly process by allowing for easy control of quick activation needs, eliminating the need for complex manual assembly of pre-assembled key switch assemblies.

Implementation Method 1

The return spring (7) is J-shaped with two legs (12, 13) which are connected to one another via a connecting region (14). The one leg (12) of the return spring (7) is attached to the tongue (9) of the locking element (6), whereas the other leg (13) of the return spring (7) is attached to the switching circuit board (2).

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3293751B1Operating mechanism for a low voltage circuit breaker
Publication Date: 2019.12.18 SIEMENS AG
  • EP3293751B1 patent drawingFigure 1~2
  • EP3293751B1 patent drawingFigure 3~4
  • EP3293751B1 patent drawingFigure 5~6

AI summary

The invention relates to a switching lock for a low-voltage protection device with two opposing switching circuit boards (1, 2), wherein a rotatable handle (3) is arranged between the switching circuit boards (1, 2) and is operatively connected to a roller (16) via a bracket (15). The invention is characterized in that the roller (15) is operatively connected to a retrofittable device for dynamic switching, by means of which a switching lever (5) is moved into a corresponding switching position.