Switch Unit With Dual Circuits For Wear Detection

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Solution Overview

Problem

Switches can fail due to wear, aging, corrosion, or vandalism, posing risks to people and equipment, and existing technologies lack effective redundancy and predictive maintenance capabilities.

Innovation Solution

A switch unit with two redundant circuits and a conductive actuating element made of polymers filled with metal or carbon particles, allowing for self-monitoring and predictive maintenance through distinct behavior patterns and force detection, enabling early detection of wear or damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single switching circuit is used, then the device complexity is low, but the reliability decreases due to sudden failures from wear, aging, corrosion, or vandalism

Engineering Contradiction:
Improveswitching circuit reliabilityVSAvoidswitching circuit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The switching circuit is segmented into two independent circuits (first switching circuit with contacts K1a/K1b and second switching circuit with contacts K2a/K2b) that share common elements (closing element, actuating element, housing) but have separate contact paths. This segmentation allows the system to tolerate partial failures while maintaining overall functionality, directly resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #1Segmentation

2Loss of information

If conventional switches are used without monitoring, then the ease of operation is high, but the loss of information occurs regarding wear state and maintenance needs

Engineering Contradiction:
Improvewear state detectionVSAvoidoperational simplicity
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The patent implements feedback mechanisms through monitoring circuits that continuously evaluate the state of switching elements (contacts, closing element, actuating element). The monitoring circuit detects changes in electrical properties (conductivity, resistance) and provides feedback signals indicating wear state, maintenance needs, or failures. This feedback system resolves the contradiction by providing critical information without significantly complicating operation, as the monitoring occurs automatically.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The switching unit performs self-monitoring and self-diagnosis through integrated monitoring circuits that automatically detect wear, damage, or failures in the switching elements. The system serves itself by continuously assessing its own state and generating maintenance alerts, eliminating the need for external inspection while preserving ease of operation. The conductive actuating element with force detection enables self-monitoring of actuation forces to detect wear or vandalism.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If the actuating element is made of conductive polymer, then the ease of manufacture and minimal wear are achieved, but the manufacturing precision may be affected

Engineering Contradiction:
Improveactuating element fabricationVSAvoidelectrical conductivity uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The actuating element is constructed from composite materials - specifically conductive polymers (polymers filled with metal or carbon particles) or intrinsically conductive polymers. These composite materials combine the mechanical flexibility and ease of molding of polymers with the electrical conductivity of metal or carbon fillers. This composite approach resolves the contradiction by enabling easy manufacturing through molding while achieving sufficient electrical conductivity uniformity for reliable switching and monitoring functions.

Inventive Principle:
Principle #40Composite materials

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 switch unit ensures higher technical availability by detecting partial or impending failures, reducing risks and allowing for timely maintenance, while the conductive actuating element provides a simple and reliable structure with minimal mechanical wear.

Implementation Method 1

an electrically conductive actuating element (15), in particular based on conductive polymers filled with metal or carbon particles or on intrinsically conductive polymers

Methodology Applied
Scientific EffectPiezoresistive effect: Piezoresistive Effect

Implementation Method 2

The actuating element (15) is made of an intrinsically conductive plastic. However, embodiments with a compounded plastic are preferred, which has obtained its electrical conductivity through the addition of electrically conductive particles, such as carbon particles, metal particles, or the like

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3879550B1Switch unit
Publication Date: 2023.02.22 SCHAEFER GMBH
  • EP3879550B1 patent drawingFigure 1~4
  • EP3879550B1 patent drawingFigure 5~8
  • EP3879550B1 patent drawingFigure 9~10

AI summary

The switching unit according to the invention utilizes a switch with a movable or deformable closing element (14) made of a single or multiple convex, planar, electrically conductive material. It is part of both a first switching circuit and a second switching circuit. In the first switching circuit, it is energized longitudinally, i.e., within its surface. In the second circuit, it is energized transversely, i.e., perpendicular to its surface. By integrating it into different switching circuits and with different current directions, it is possible to detect faults before the switching unit (10) fails completely and to maintain operation initially.Furthermore, the closing element (14) is preferably moved by an electrically conductive actuating element made of plastic, which reduces wear and offers further design possibilities, particularly with regard to the detection of the actuating force.