Escalator Handrail Tension Detection Using Temperature Difference

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Solution Overview

Problem

Existing escalators lack effective methods to detect and prevent excessive tension in handrails, leading to increased wear and reduced lifetime due to high tension settings.

Innovation Solution

Incorporating temperature sensors at key points along the handrail and ambient reference sensors, connected to a processing unit that compares temperature measurements to detect excess tension by identifying heat input differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tension in the handrail is increased to ensure smooth running, then handrail stability improves, but handrail wear increases and lifetime decreases

Engineering Contradiction:
Improvehandrail stabilityVSAvoidhandrail lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the parameter being monitored from mechanical tension (which is difficult to measure) to temperature (which is easily measurable). By detecting temperature changes in the handrail that correspond to excessive tension, the system can identify when tension levels are harmful and alert operators to adjust them, thus preventing excessive wear while maintaining adequate tension for smooth operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces direct mechanical tension measurement with thermal sensing. Instead of using mechanical sensors that would interfere with the handrail's operation, the system uses temperature sensors to indirectly detect tension levels through the heat generated by excessive tension, providing a non-intrusive monitoring solution.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If tensioning device is adjusted to provide high tension, then handrail runs smoothly, but excessive tension is set accidentally leading to short lifetime

Engineering Contradiction:
Improvehandrail smooth runningVSAvoidhandrail lifetime
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where temperature sensors continuously monitor the handrail's temperature, and when excessive temperature (indicating excessive tension) is detected, the system generates an alert or signal to operators. This feedback loop allows operators to adjust the tensioning device to optimal levels, preventing accidental over-tensioning while maintaining smooth operation.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If temperature sensor and reference temperature sensor are provided to measure handrail temperature, then excess tension can be detected, but device complexity increases

Engineering Contradiction:
Improveexcess tension detectionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses the handrail's own temperature as the measurement parameter, which naturally provides information about excessive tension without requiring external power sources or complex measurement systems. The temperature difference between the handrail and ambient environment serves as a built-in indicator of problematic tension levels, simplifying the overall system architecture.

Inventive Principle:
Principle #25Self-service

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

Effectively detects and prevents excessive handrail tension, reducing wear and extending the lifespan of handrails by identifying and adjusting tension levels.

Implementation Method 1

at least a first temperature sensor provided at the first handrail for measuring the first handrail's temperature

Methodology Applied
Scientific EffectTemperature sensing: Thermal Radiation

Data Source

PatentEP4524080B1Escalator and method to detect excess tension at a handrail
Publication Date: 2026.01.14 TK ESCALATOR NORTE SA
  • EP4524080B1 patent drawingFigure 1a~3

AI summary

The invention refers to an escalator (1), comprising: a support structure (2), a number of steps (3) or pallets or a moving belt guided in a circulating manner and forming a path (4), a first handrail (7.1) guided in a circulating manner and being turned around by newels (9.1, 9.2), a first tensioning device for tensioning the first handrail (7.1), a first temperature sensor (11.1) provided at the first handrail (7.1) for measuring the first handrail's (7.1) temperature, a first reference temperature sensor (12.1) for the first temperature sensor (11.1) and a processing unit (16) configured to receive measuring values from the first temperature sensor (11.1) and the first reference temperature sensor (12.1), wherein the processing unit (16) is configured to compare the measuring values of the first temperature sensor (11.1) and the measuring values of the first reference temperature sensor (12.1).