Elevator Safety Sensor Testing Relay

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing elevator systems require regular testing of safety sensors in the safety chain to ensure safe operation, but existing methods compromise the integrity of the safety chain or fail to provide automatic and reliable testing.

Innovation Solution

A testing arrangement that includes a test circuit and a switchable testing relay, allowing safety sensors to be disconnected from the safety chain and connected to a test circuit for operability testing without adding additional circuitry, ensuring compliance with safety standards like EN-81.20.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If safety sensors are regularly tested to ensure safe operation, then reliability is improved, but the integrity of the safety chain is compromised

Engineering Contradiction:
Improvesafety sensor testingVSAvoidsafety chain integrity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent extracts the safety sensors from the safety chain during testing by using a testing relay to disconnect them. This allows the sensors to be tested individually or in groups without affecting the overall safety chain integrity, as the disconnecting action is temporary and controlled.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the safety sensors into testable groups or individuals using the testing relay, which can connect or disconnect specific sensors from the safety chain. This segmentation enables targeted testing of one or more sensors while maintaining the rest of the safety chain operational.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If additional circuitry is added to test safety sensors, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvesensor operability testingVSAvoidcircuitry additions
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The testing relay serves multiple functions: it acts as a normal relay in the safety chain and simultaneously functions as a testing device that can connect or disconnect sensors for testing purposes. This multi-functionality eliminates the need for separate additional circuitry dedicated solely to testing.

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

Solution Approach 2:

The existing relay structure in the safety chain is made to serve the additional function of sensor testing. The relay's inherent switching capability is utilized to perform testing operations, allowing the system to test its own components without requiring external specialized testing equipment.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3271278B1Elevator testing arrangement
Publication Date: 2020.10.07 OTIS ELEVATOR CO
  • EP3271278B1 patent drawingFigure 1
  • EP3271278B1 patent drawingFigure 2a~2b
  • EP3271278B1 patent drawingFigure 3a~3b

AI summary

A testing arrangement (36) for testing the operability of at least one safety sensor (21, 22, 23, 26, 28) connected to the safety chain (30) of an elevator system (1), the testing arrangement (36) comprises: at least one test circuit (34) for testing the operability of the at least one safety sensor (21, 22, 23, 26, 28); and at least one testing relay (32, 33). The testing relay (32, 33) is switchable between an operational position and a test position and it is configured for electrically connecting the at least one safety sensor (21, 22, 23, 26, 28) to the safety chain (30) in the operational position and for electrically connecting the at least one safety sensor (21, 22, 23, 26, 28) to the test circuit (34) in the test position.