Elevator Safety Circuit With Sensor State Localization

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Solution Overview

Problem

Conventional switching devices and safety devices for elevators face challenges in accurately determining the switching states of sensors, particularly when multiple sensors are connected in series, making it difficult to identify which sensor is defective, and requiring extensive maintenance efforts.

Innovation Solution

A switching device with a communication unit that modulates resistance, voltage, or current to transmit information between sensors and a switching unit, allowing individual sensors to communicate and switch states without interrupting the electrical line, enabling centralized monitoring and easier retrofitting by using a single communication line.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional opening switches connected in series are used to monitor door closed status, then the safety function is achieved, but it becomes impossible to identify which switch is defective or interrupted

Engineering Contradiction:
Improvedoor safety monitoringVSAvoidswitch defect localization
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the monitoring function into individual sensor units, each capable of independent communication with the switching unit. This segmentation allows each sensor to be individually identified and monitored, enabling defect localization while maintaining the overall safety monitoring function through the distributed sensor network.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If opening switches connected in series are used, then the circuit is simple, but an open switch causes a line break that interrupts the entire circuit

Engineering Contradiction:
Improvecircuit structureVSAvoidcircuit continuity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces communication units as intermediaries between sensors and the switching unit. These communication units enable data transmission without requiring physical electrical contact, allowing the circuit to remain continuous even when sensor switches are open, thus maintaining reliability while simplifying the physical circuit structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional switching devices are used, then installation is straightforward, but retrofitting requires extensive modifications to existing wiring

Engineering Contradiction:
Improveinstallation simplicityVSAvoidretrofit capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent designs the switching unit with integrated communication capabilities that can interface with both conventional switching devices and modern sensor systems. The communication unit can interpret various signal types and protocols, making the system universally compatible and easily adaptable to different installation scenarios including retrofits, without requiring extensive wiring modifications.

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

4Reliability

If multiple sensors are connected in series for monitoring, then the safety coverage is improved, but the difficulty of identifying individual sensor states increases

Engineering Contradiction:
Improvesafety coverageVSAvoidindividual sensor state information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent implements a feedback communication system where each sensor transmits its individual switching state to the switching unit through dedicated communication channels. This feedback mechanism provides real-time information about each sensor's state, maintaining complete visibility of individual sensor conditions while allowing multiple sensors to operate in parallel for enhanced safety coverage.

Inventive Principle:
Principle #23Feedback

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 solution enhances the localization of sensor switching states, reduces maintenance complexity, and allows for efficient retrofitting by enabling sensors to communicate and switch states without line interruptions, improving the reliability and safety of elevator systems.

Implementation Method 1

communication can take place via a modulation of its own resistance of the sensor

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

the switching unit is in turn designed to carry out the communication with the sensors by modulating the current intensity or the voltage

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 3

If the resistance of a sensor is fundamentally changed when the sensors are connected in series, then the current intensity changes according to Ohm's law. If a constant current source is then used for the circuit, a change in resistance will cause the voltage to increase to compensate for the resulting decrease in current

Methodology Applied
Scientific EffectOhm's Law: Ohm's Law

Data Source

PatentEP2567926B1Circuit device, safety device and lift device
Publication Date: 2013.10.09 CEDES AG
  • EP2567926B1 patent drawingFigure 1~3
  • EP2567926B1 patent drawingFigure 4~6
  • EP2567926B1 patent drawingFigure 7~8

AI summary

A circuit device is proposed which includes at least one sensor (1, 1', 10) for detection, which can be switched between at least two switching states depending on the detection. To enable improved localization of the switching states, a switching unit (12, 12', 12'', 25, 27) is provided, wherein the switching unit and the at least one sensor each have a communication unit (50, 51) for communication with each other, and the switching unit can be switched depending on the at least one sensor.