Elevator Refuge Space Weight Sensor Safety Detection

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Solution Overview

Problem

Existing elevator safety systems may fail or be inadequately followed by maintenance workers, leading to risks of injury or entrapment for individuals in refuge spaces during elevator operations.

Innovation Solution

An elevator system that detects objects in refuge spaces using weight-sensing technology, such as pressure sensors or piezoelectric materials, to automatically generate a safety signal and trigger appropriate safety responses, such as emergency stops or reduced speed operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If existing safety systems and inspection mode protocols are used, then maintenance workers can access refuge spaces for maintenance work, but the risk of injury or entrapment increases when safety systems fail or protocols are not followed

Engineering Contradiction:
ImproveAccess to refuge space for maintenanceVSAvoidRisk of injury or entrapment
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces manual activation of safety systems with automatic sensor-based detection. Weight sensors automatically detect the presence of maintenance workers in refuge spaces and trigger safety modes without requiring manual intervention, thereby eliminating the risk associated with human error or failure to follow protocols.

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

Solution Approach 2:

The safety system becomes self-activating by automatically detecting worker presence through weight sensors and initiating safety protocols without human intervention. The system serves itself by monitoring its own operational state and autonomously responding to potential hazards.

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If the elevator car is placed in inspection mode to protect maintenance workers, then worker safety is improved, but the elevator system loses automated operational control and requires manual operation

Engineering Contradiction:
ImproveWorker safetyVSAvoidElevator operational control
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent implements dynamic switching between automated and manual operational modes based on real-time sensor input. The elevator system automatically transitions to manual inspection mode when workers are detected in refuge spaces, and can automatically resume normal operation when the space is clear, providing adaptability rather than static operational states.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses weight sensors to provide continuous feedback on the presence of maintenance workers. This feedback loop enables the control system to automatically adjust operational mode based on current conditions, switching between automated and manual control as needed without requiring manual mode changes.

Inventive Principle:
Principle #23Feedback

3Reliability

If weight sensors are installed in refuge spaces to detect maintenance workers, then automatic safety detection is improved, but device complexity and installation requirements increase

Engineering Contradiction:
ImproveAutomatic safety detectionVSAvoidSensor installation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent utilizes the elevator car roof structure to serve multiple functions: it provides the refuge space platform, acts as the mounting surface for weight sensors, and functions as the detection surface itself. This multi-functionality reduces the need for separate sensor mounting structures and simplifies installation.

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

Solution Approach 2:

The patent employs thin film weight sensors that can be directly applied to the elevator car roof surface. These flexible sensors integrate seamlessly with the existing structure, requiring minimal installation infrastructure and reducing overall system complexity compared to rigid sensor assemblies.

Inventive Principle:
Principle #30Flexible shells and thin films

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

Enhances safety in refuge spaces by ensuring that the elevator system is aware of and responds to the presence of individuals, even if standard safety protocols are not followed, thereby reducing the risk of injury or entrapment.

Implementation Method 1

The sensor comprises a piezoelectric material

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4345043B1Elevator safety system
Publication Date: 2025.04.16 OTIS ELEVATOR CO
  • EP4345043B1 patent drawingFigure 1
  • EP4345043B1 patent drawingFigure 2
  • EP4345043B1 patent drawingFigure 3

AI summary

An elevator system (1) including at least one refuge space (7, 8) and at least one sensor (9). The at least one sensor (9) is configured to detect weight in the at least one refuge space (7, 8) and produce at least one safety signal (21) indicating the presence of weight in the at least one refuge space (7, 8). The system can be used to improve the safety in the at least one refuge space (7, 8) in the event that the usual safety procedures have either failed or not been followed. For example, if for some reason the elevator system (1) has not been placed into a safe state before a maintenance worker (10) accesses the at least one refuge space (7, 8), the system will detect them and can produce at least one safety signal (21) immediately indicating their presence in the at least one refuge space (7, 8).