Temperature Switch Housing Seal Against Solder and Contaminant Ingress

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Solution Overview

Problem

Existing temperature-dependent switches face issues with mechanical sealing, particularly due to insulating foils wrinkling or curling, leading to leakage paths for liquids and contaminants, which are difficult to detect and rectify.

Innovation Solution

The introduction of a sealing ring on the upper side of the cover part, which is in sealing contact with the bent upper section of the wall, enhances mechanical sealing without the need for insulating foils, allowing for automated and cost-effective production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulating foils are used to electrically insulate housing parts, then electrical insulation is achieved, but mechanical sealing deteriorates due to wrinkling and curling

Engineering Contradiction:
Improveelectrical insulationVSAvoidleakage paths for liquids and contaminants
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a sealing ring as an intermediary component between the insulating foil and the housing parts. This sealing ring prevents direct contact between liquids/contaminants and the insulating foil, eliminating the wrinkling and curling problems while maintaining both electrical insulation and mechanical sealing functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the sealing function into separate components: the insulating foil handles electrical insulation while the sealing ring handles mechanical sealing. This segmentation allows each component to perform its specific function optimally without interfering with the other, preventing the wrinkling and curling issues.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If manual sealing methods are used to prevent ingress during production, then sealing effectiveness is improved, but productivity deteriorates due to increased complexity and time

Engineering Contradiction:
Improveingress of solder, varnishes, and contaminantsVSAvoidproduction efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The sealing ring is pre-installed on the housing parts before the production processes (soldering, varnishing) begin. This preliminary sealing action prevents ingress of contaminants during these processes without requiring manual sealing operations, thereby maintaining both sealing effectiveness and production efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sealing ring provides automatic sealing protection without requiring manual intervention during production. The component's design inherently prevents ingress of solder, varnishes, and contaminants during automated production processes, eliminating the need for additional manual sealing steps.

Inventive Principle:
Principle #25Self-service

3Strength

If the upper section of the wall is bent over to hold the cover part, then mechanical fastening is achieved, but sealing capability deteriorates due to deformation and gaps

Engineering Contradiction:
Improvemechanical fasteningVSAvoidleakage paths
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The sealing ring acts as an intermediary between the bent upper section of the wall and the cover part. It accommodates the deformation from bending while maintaining continuous sealing contact, preventing leakage paths even under mechanical stress.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing ring is designed as a flexible component that can deform with the bent wall section while maintaining sealing effectiveness. This flexibility allows it to adapt to the mechanical fastening configuration without creating gaps or leakage paths.

Inventive Principle:
Principle #30Flexible shells and thin films

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 sealing ring effectively prevents the ingress of solder, varnishes, and contaminants into the switch interior, ensuring a reliable mechanical seal and reducing the risk of internal damage during production processes.

Implementation Method 1

a sealing ring is arranged on the upper side of the cover part and is in sealing contact with the bent over, upper section of the wall

Methodology Applied
Scientific EffectSealing contact:

Implementation Method 2

an insulating foil is provided between them, which runs parallel to the cover and is laterally extended upwards

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

a temperature-dependent switching function, which has a spring-loaded snap-action disc carrying a movable contact part, as well as a bimetallic disc fitted over the movable contact part

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

a spring-loaded snap-action disc pressing the movable contact part against a stationary counter-contact

Methodology Applied
Scientific EffectElastic energy storage: Elasticity

Data Source

PatentEP4369374B1Temperature-dependent switch
Publication Date: 2025.08.27 HOFSAESS MARCEL P
  • EP4369374B1 patent drawingFigure 1
  • EP4369374B1 patent drawingFigure 2
  • EP4369374B1 patent drawingFigure 3

AI summary

Temperature-dependent switch (10) with a housing (12) comprising a cover part (16) with a top (24) and a lower part (14) with a raised, circumferential wall (28), the upper section (30) of which is bent over onto the top (24) of the cover part (16) and thereby holds the cover part (16) to the lower part (14), wherein two contact surfaces (48, 50) are provided on the outside of the housing (12) and a switching mechanism (34) is arranged in the housing (12) which is configured to switch, depending on its temperature, between a closed state, in which the switching mechanism (34) establishes an electrically conductive connection between the two contact surfaces, and an open state, in which the switching mechanism (34) opens the electrically conductive connection between the two contact surfaces (48, 50). On the top side (24) of the lid part (16) a sealing ring (32) is arranged, which is in sealing contact with the bent, upper section (30) of the wall.