Elevator Rope Elongation Detection With Displacement Threshold Triggering

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Solution Overview

Problem

Existing elevator rope elongation detection devices are limited in applicability, have complex structures, and suffer from low sensitivity and false detection triggers, particularly in emergency situations.

Innovation Solution

A device comprising brackets, a coupling member, and a trigger is installed in the rope head device to detect elevator rope elongation, allowing for adjustable sensitivity and preventing false triggers by using a coupling member that contacts the bracket only after a preset displacement threshold is exceeded.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing detection devices are installed on elevator equipment with two steel belts, then they can detect rope elongation, but they cannot be applied to other elevator equipment with more steel belts

Engineering Contradiction:
Improveapplicability to different elevator configurationsVSAvoiddetection device structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The detection device is designed with a coupling member that can connect to multiple brackets simultaneously, enabling it to work with elevator equipment having different numbers of steel belts (two, three, or more). This universal design allows the same device structure to be applied across various elevator configurations without requiring configuration changes or multiple specialized devices.

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

2Measurement precision

If detection devices have complicated structure, then they may provide detailed detection capability, but they have limited installation and arrangement location

Engineering Contradiction:
Improvedetection sensitivityVSAvoidinstallation and arrangement flexibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The detection device is divided into separate functional modules: brackets installed on the rope head device, a coupling member with holes for connection, and a trigger mechanism. This segmentation allows each component to be independently optimized and installed at convenient locations, with the coupling member serving as a flexible connector that can be positioned to achieve both precision and ease of installation.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If detection devices are designed to detect small rope elongation rate, then detection sensitivity is improved, but false detection trigger occurs easily in elevator emergency stop

Engineering Contradiction:
Improvedetection sensitivityVSAvoidfalse detection trigger
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The coupling member is pre-configured with holes at specific positions that align with the trigger mechanism only when a certain displacement threshold is exceeded. This preliminary arrangement ensures that the trigger is activated only when actual rope elongation reaches dangerous levels, preventing false triggers during normal operation or emergency stops while maintaining high sensitivity for detecting real elongation problems.

Inventive Principle:
Principle #10Preliminary action

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 device provides flexible detection sensitivity, easy installation, and avoids false triggers, ensuring reliable real-time monitoring of elevator rope conditions for enhanced safety and reliability.

Implementation Method 1

one and more brackets connected to an elastic reset member in the rope head device

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4631902A1Device and method for detecting elevator rope elongation and elevator
Publication Date: 2025.10.15 OTIS ELEVATOR CO
  • EP4631902A1 patent drawingFigure 1
  • EP4631902A1 patent drawingFigure 2~3
  • EP4631902A1 patent drawingFigure 4~5

AI summary

A device and a method for detecting elevator rope elongation, and an elevator are disclosed. An elevator rope is connected to a rope head device and an operating device in an elevator, and the device for detecting elevator rope elongation includes: one and more brackets connected to an elastic reset member in the rope head device, a coupling member connected to at least one of the brackets and configured to be driven into a trigger position by the at least one bracket when the displacement of the elastic reset member exceeds a threshold value due to reduction of compression amount, and a trigger connected to the coupling member and configured to be triggered to generate a trigger signal when the coupling member is driven into the trigger position. The present disclosure can be widely applied to detect the elevator rope elongation condition in many types of elevator equipment.