Temperature-Dependent Switch Sealing with Cutting Burr
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Solution Overview
Problem
Existing temperature-dependent switches face sealing issues due to the inability of stiff insulating foils to achieve a lasting seal, leading to contamination ingress and increased production complexity and costs.
Innovation Solution
A temperature-dependent switch design featuring a circumferential cutting burr on a sealing ring, which penetrates into the insulating foil or cover part, creating a mechanical barrier to prevent contamination and simplifying production by separating the cutting burr from the lower part, allowing for easier and more cost-effective manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stiff insulating foil is used to provide electrical insulation between the lower part and the cover part, then electrical insulation is achieved, but the foil cannot achieve a lasting seal allowing contamination ingress
Solution Approach 1:
The sealing function is segmented from the insulating foil by introducing a separate sealing ring with an elastomeric material. The sealing ring is inserted into a circumferential groove of the lower part, creating a dedicated sealing component that can independently perform sealing without compromising the electrical insulation function of the insulating foil.
Solution Approach 2:
The sealing ring acts as an intermediary element between the lower part and the cover part. It provides the sealing function that the stiff insulating foil cannot achieve, while the insulating foil continues to provide electrical insulation. The elastomeric material of the sealing ring allows it to deform and create a reliable seal against contamination ingress.
2Reliability
If the cutting burr is integrated into the lower part to provide sealing, then sealing is achieved, but production complexity and costs increase
Solution Approach 1:
The sealing ring is separated from the lower part as an independent component. The sealing ring is inserted into a circumferential groove of the lower part, allowing both components to be manufactured separately using standard processes. This segmentation simplifies production compared to integrating a cutting burr into the lower part, while still achieving reliable sealing through the elastomeric material of the sealing ring.
Solution Approach 2:
The sealing ring is a simple, inexpensive component made from elastomeric material that can be easily manufactured and replaced if necessary. Its simplicity and low cost make it an economical solution compared to integrating a complex cutting burr structure into the lower part.
3Stability of the object's composition
If the insulating foil is made stiff to maintain structural integrity, then structural stability is achieved, but sealing capability is lost
Solution Approach 1:
The functions of structural support, electrical insulation, and sealing are segmented into different components. The insulating foil maintains its stiff structure for structural integrity and electrical insulation, while the sealing function is assigned to the elastomeric sealing ring that can deform to create a reliable seal.
Solution Approach 2:
Different parts of the assembly have different material properties optimized for their specific functions. The insulating foil is stiff and non-compliant for structural and insulation purposes, while the sealing ring is made of elastomeric material with local compliance to achieve sealing. This local differentiation of material properties allows both structural stability and sealing reliability to be achieved simultaneously.
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 cutting burr provides a reliable seal against dirt and fluids, preventing varnish or resin from entering the switch, while reducing production costs by allowing the lower part to be produced as a punched part, maintaining electrical insulation and sealing effectiveness.
Implementation Method 1
a bimetal snap-action disc (30) which changes, depending on the temperature, between a first stable geometric configuration in its low temperature position and a second stable geometric configuration in its high temperature position
Implementation Method 2
a circumferential cutting burr (54) which penetrates into the insulating foil (22) or cover part (18), creating a mechanical barrier to prevent contamination
Data Source
AI summary
A temperature-dependent switch having a housing that comprises a cover part and an electrically conductive lower part. The switch further comprises a first external contact surface arranged on the upper side of the cover part, and a second external contact surface provided externally on the housing. Still further, the switch comprises a temperature-dependent switching mechanism that is arranged in the housing and that, depending on its temperature, establishes or opens an electrically conductive connection between the first and the second external contact surfaces. A circumferential cutting burr acting as a sealing means is furthermore provided, that penetrates into the insulating foil or the cover part, wherein the cutting burr is arranged on a sealing ring that is connected to the lower part by means of a non-positive, positive and/or firmly bonded connection.