Movable Contact Assembly Using Yokes to Stabilize Contact Force

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Solution Overview

Problem

Existing electromagnetic contactors struggle with electromagnetic repulsive forces that deteriorate contact reliability between movable and fixed contacts, leading to unreliable electrical connections and increased movement force requirements.

Innovation Solution

A movable contact assembly with an upper yoke and auxiliary contact housing structure that generates a magnetic attractive force to counteract repulsive forces, maintaining a stable attractive state and reducing the required movement force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple yokes are arranged adjacent to the fixed contact and movable contact to generate magnetic attractive force, then contact reliability is improved, but the distance between yokes increases causing magnetic attractive force to decrease

Engineering Contradiction:
Improvecontact reliabilityVSAvoidmagnetic attractive force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent implements nesting by placing the upper yoke inside the auxiliary contact housing, which is itself coupled to the movable frame. This nested arrangement allows the yokes to be positioned close together (maintaining strong magnetic force) while still providing sufficient spacing for reliable contact operation. The auxiliary contact housing acts as an intermediary structure that enables the compact nesting of magnetic components.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a single-dimensional linear arrangement of yokes to a multi-dimensional configuration where the upper yoke is positioned both axially and radially relative to the lower yoke. The auxiliary contact housing provides a three-dimensional framework that allows the yokes to be arranged in space optimally - close enough for strong magnetic attraction but with proper spacing for contact reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If yokes are arranged farther apart to accommodate contact components, then assembly space is improved, but magnetic attractive force decreases making it difficult to offset electromagnetic repulsive force

Engineering Contradiction:
Improveassembly spaceVSAvoidmagnetic attractive force
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The upper yoke is nested within the auxiliary contact housing structure, allowing compact arrangement of magnetic components within the available assembly space. This nesting enables the yokes to be positioned close together for strong magnetic force while still accommodating all necessary contact components within the overall device envelope.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The auxiliary contact housing serves multiple functions: it provides structural support, houses the upper yoke, and facilitates the magnetic coupling between yokes. By merging these functions into a single integrated component, the design achieves compact assembly space while maintaining strong magnetic attractive force through optimal yoke positioning.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If auxiliary contact housing is coupled to upper yoke and fixedly coupled to movable frame, then assembly efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveassembly efficiencyVSAvoidstructural complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The auxiliary contact housing is designed as a multi-functional component that combines structural support, magnetic component mounting, and movable frame coupling into a single part. This merging reduces the total number of separate components and assembly steps, thereby improving assembly efficiency while the integrated design actually simplifies rather than complicates the overall structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The auxiliary contact housing performs multiple functions simultaneously: it serves as a mounting structure for the upper yoke, provides fixed coupling to the movable frame, and facilitates the magnetic circuit. This multi-functionality reduces the need for separate dedicated components for each function, improving assembly efficiency without increasing overall device complexity.

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

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

The solution effectively cancels electromagnetic repulsive forces, stabilizes the contact state, reduces movement force, and allows for a compact design while ensuring reliable electrical connections.

Implementation Method 1

an upper yoke coupled to the auxiliary contact housing to maintain its position, and arranged to face the lower yoke with the movable contact located therebetween, and configured to generate a magnetic attractive force together with the lower yoke

Methodology Applied
Scientific EffectMagnetic attractive force: Electromagnet

Data Source

PatentEP4715861A1Movable contact assembly and electromagnetic contactor including same
Publication Date: 2026.03.25 LS E-MOBILITY SOLUTIONS CO LTD
  • EP4715861A1 patent drawingFigure 1
  • EP4715861A1 patent drawingFigure 2
  • EP4715861A1 patent drawingFigure 3

AI summary

Disclosed are a movable contact assembly and an electromagnetic contactor including same. The movable contact assembly and the electromagnetic contactor including same, according to an aspect of the present invention, comprise: a movable contact provided to be movable in a direction toward a fixed contact and a direction opposite to the fixed contact; a lower yoke which is located adjacent to the movable contact and is provided to be movable together with the movable contact; an upper yoke which partially surrounds the movable contact and is configured to form a magnetic attractive force together with the lower yoke; and an auxiliary contact housing electrically connected to an auxiliary contact, coupled to the upper yoke, and fixedly coupled to a movable frame.