Adjustable End Stop Contact Structure for Dust-Sealed Switching

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Solution Overview

Problem

Existing energy-saving contacts in power electronics are prone to contamination by dust due to large passage holes in the electrical board, which can block current flow and affect the proper functioning of the contactor.

Innovation Solution

The design includes a fixed part with a passage orifice for the stop that has an internal section identical to the external section of the stop, allowing the stop to translate in a perpendicular plane, with a minimal clearance to prevent dust entry and precise adjustment of the stop's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a large passage hole is provided in the electrical board for the stop, then positioning tolerances are accommodated, but dust can enter and block current flow

Engineering Contradiction:
Improvepositioning tolerance accommodationVSAvoiddust contamination
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The passage orifice is segmented into two functional zones: an upper portion that allows stop passage with tolerance accommodation, and a lower portion that forms a dust-tight seal when the stop is in its lower position. This segmentation enables the same structure to serve both positioning tolerance accommodation and dust prevention functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stop itself acts as an intermediary element that performs dual functions: it serves as the positioning reference (allowing tolerance through the orifice) and simultaneously acts as a dust barrier when positioned in the lower position, blocking the passage orifice to prevent dust entry.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the stop is tightly fitted in the passage orifice to prevent dust entry, then dust contamination is prevented, but manufacturing tolerances cannot be accommodated

Engineering Contradiction:
Improvedust contamination preventionVSAvoidpositioning tolerance accommodation
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The stop is designed to be movable within the passage orifice, transitioning between an upper position (for assembly and tolerance accommodation) and a lower position (for dust sealing). This dynamic positioning allows the system to adapt to manufacturing tolerances while maintaining dust prevention capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The passage orifice has different functional requirements at different locations: the upper portion allows clearance for tolerance accommodation, while the lower portion requires tight fitting for dust prevention. This local differentiation of quality enables both tolerance accommodation and dust sealing.

Inventive Principle:
Principle #3Local quality

3Loss of time

If the energy-saving contact opens too early due to premature stop-blade interaction, then the contactor switches to holding coil mode, but the moving part may lack power to complete the stroke

Engineering Contradiction:
Improveswitching timingVSAvoidstroke completion
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The mechanical interaction between the stop and blade is replaced by a precisely controllable electromagnetic force. The actuating coil generates magnetic force that acts on the core mounted on the moving part, providing reliable and controllable stroke completion without dependence on mechanical stop-blade timing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If the energy-saving contact opens too late due to delayed stop-blade interaction, then the moving part has sufficient power, but the separation distance is too short causing rebound or sticking

Engineering Contradiction:
Improvestroke powerVSAvoidcontact separation
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The mechanical stop-blade interaction that determines contact separation timing is replaced by electromagnetic control. The actuating coil can be precisely controlled to generate sufficient magnetic force throughout the entire stroke, ensuring reliable contact separation without rebound or sticking, regardless of mechanical timing variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 design effectively prevents dust contamination, ensuring reliable operation of the energy-saving contact by maintaining a closed contact at rest and opening at the end of the moving part's travel, while allowing for easy assembly and adjustment without tight manufacturing tolerances.

Implementation Method 1

The moving part 3 is driven in translation towards its upper position by the action of an actuating coil when an actuating current flows through it, acting by induction on a core mounted on the moving part 3 and engaged between the turns of the actuating coil.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an elastic blade fixed to the fixed part at one end and whose second end forms an energy-saving contact

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4537374B1Energy-saving contact with adjustable end stop
Publication Date: 2026.01.14 SAFRAN ELECTRICAL & POWER
  • EP4537374B1 patent drawingFigure 1~2
  • EP4537374B1 patent drawingFigure 3~4

AI summary

The invention relates to an energy-saving contact (1) comprising a fixed part (2) and a mobile part (3) able to move in a main direction (Z) between a contact position and a breaking position, the energy-saving contact (1) comprising a spring blade (8) fixed to the fixed part (2) and forming an electrical contact, as well as an end stop (10) mounted on the mobile part (3) and arranged so as to be distant from the blade (8) and to come to press against the blade (8) when the mobile part (3) is in the contact position. The fixed part (2) defines an orifice (11) through which the end stop (10) passes opposite the blade (8), the orifice (11) having an internal cross section substantially identical to an external cross section of the end stop (10), the end stop (10) being mounted on the mobile part (3) such as to be mobile translationally in a plane (XY).