Elevator Light Curtain Testing via Moving Test Element

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Solution Overview

Problem

Conventional elevator systems face challenges in ensuring the continuous functionality of light curtain units during operation, particularly when the elevator car is moving, as existing methods for testing these units can complicate safety processes and may not accurately differentiate between interruptions caused by the test element and other objects.

Innovation Solution

A method and system where a test element is strategically positioned within the elevator shaft to interrupt the light beam when the elevator car moves, utilizing a position detection device to ensure that only the test element causes interruptions, allowing for efficient testing of the light curtain units without compromising safety, and an evaluation unit processes the data to maintain or suspend elevator operation as necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the light curtain unit is tested during door operation, then the functionality can be verified, but the safety process becomes complicated

Engineering Contradiction:
Improvelight curtain functionalityVSAvoidsafety process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The test element is pre-positioned in the elevator shaft at a location that ensures it will interrupt the light beam during elevator car movement. This preliminary positioning allows automatic testing to occur during non-safety-critical periods without requiring complex real-time decision-making or interfering with door operation safety protocols.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the test element interrupts the light beam during car movement, then testing can occur, but differentiation from other interruptions becomes difficult

Engineering Contradiction:
Improvetesting efficiencyVSAvoidinterruption source identification
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The test element acts as a known intermediary object with specific, predetermined characteristics. Its fixed position in the elevator shaft and known geometry allow the evaluation unit to distinguish its interruptions from other objects based on the consistent pattern of light beam interruption, thereby maintaining measurement precision while enabling continuous testing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The evaluation unit continuously monitors light beam interruptions and provides feedback about the test element's position and the light curtain's response. This feedback mechanism allows the system to verify that interruptions are caused by the test element at the expected location and time, enabling precise differentiation between test-related interruptions and other potential issues.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If the transmitter and receiver are on the elevator car, then all shaft doors can be monitored, but the system complexity increases

Engineering Contradiction:
Improvedoor monitoring coverageVSAvoidsystem configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The transmitter and receiver units mounted on the elevator car serve multiple functions: they monitor all shaft doors along the car's path, enable testing during movement, and provide continuous coverage without requiring separate units at each shaft door. This multi-functionality achieves universal door monitoring while actually reducing overall system complexity compared to distributing units across multiple locations.

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

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

Enables reliable and efficient testing of light curtain units during non-safety critical periods, ensuring the system's safety by differentiating between test element and other interruptions, and facilitating prompt maintenance or service when necessary.

Implementation Method 1

a transmitter unit (16) for emitting a light beam (21) and a receiver unit (18) for receiving the light beam (21)

Methodology Applied
Scientific EffectLight beam transmission and reception: Light

Data Source

PatentEP3728096B1Lift assembly with a light curtain unit
Publication Date: 2023.02.01 INVENTIO AG
  • EP3728096B1 patent drawingFigure 1
  • EP3728096B1 patent drawingFigure 2~3
  • EP3728096B1 patent drawingFigure 4

AI summary

The invention relates to a lift system (1) comprising a lift shaft (2) and a door opening (11, 13), and a transmitter unit (16) for emitting at least one light beam (21) and a receiver unit (18) for receiving the light beam (21), wherein the transmitter unit (16) is arranged on a first side of the door opening (11, 13) and the receiver unit (18) is arranged on the other side of the door opening (11, 13), as well as comprising a test element (30) for testing the receiver unit and/or for testing the transmitter unit (16), wherein the light beam (21) between the transmitter unit and the receiver unit (16, 18) can be interrupted by the test element (30). The invention also relates to a method for testing a receiver unit (18) or a transmitter unit (16) of this type.