Elevator Safety Space Formation via Optical Detection

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Solution Overview

Problem

Current elevator safety systems during servicing are unreliable and complex, particularly in determining whether the elevator car is within a safe zone, and existing solutions may expose servicing employees to danger due to unclear activation status and unpredictable movement.

Innovation Solution

A safety arrangement that uses floor level door detectors to initiate a mechanical or electrical safety mechanism, ensuring the elevator car is locked or stopped at a safe position based on the opening of specific landing doors, creating a reliable safe space for servicing regardless of the elevator car's position within the hoistway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a predefined safety height is set close to the end of the hoistway to enable visual observation, then the safety space becomes shallower and easier to monitor visually, but the safety gear activation distance becomes unpredictable and the safety space may be insufficient

Engineering Contradiction:
Improvevisual observation accuracyVSAvoidsafety space sufficiency
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces visual observation with an optical detection system (light source and light receiver) that automatically measures the position of the elevator car relative to the safety height, eliminating the need for human visual judgment and providing precise, objective measurement of the car's position

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

Solution Approach 2:

The patent introduces an intermediary detection system consisting of a light source, light receiver, and evaluation unit that acts as a mediator between the elevator car position and the safety gear activation, providing reliable and predictable control based on precise optical measurement rather than unpredictable visual observation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If remote control safety system activation is used, then the servicing employee can activate safety from a distance, but it becomes unclear whether the safety system is reliably activated

Engineering Contradiction:
Improvesafety activation convenienceVSAvoidsafety activation status clarity
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the evaluation unit continuously monitors the light receiver signal and provides real-time information about the elevator car's position relative to the safety height, ensuring the servicing employee knows the safety system is actively monitoring and when activation is needed

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The safety system automatically activates the safety gear when the evaluation unit detects that the elevator car has reached the predefined safety height, eliminating the need for manual remote control activation and ensuring reliable automatic response based on precise optical detection

Inventive Principle:
Principle #25Self-service

3Reliability

If the elevator car is stopped at a safe position using door detectors, then the safe working space is clearly defined, but the system complexity increases due to multiple detectors and coordination requirements

Engineering Contradiction:
Improvesafe space definition clarityVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the safety height detection function from the complex door-level monitoring system and implements it as a separate optical detection system positioned at the predefined safety height, simplifying the overall system by dedicating a specific detection mechanism to the critical safety function

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The optical detection system serves multiple functions: it detects the elevator car position, determines when the safety height is reached, and triggers safety gear activation, consolidating what would otherwise require multiple separate detection and control mechanisms into a single integrated system

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

Data Source

PatentEP2941399B1Elevator and means for forming a safety space
Publication Date: 2020.05.13 KONE OYJ
  • EP2941399B1 patent drawingFigure 1
  • EP2941399B1 patent drawingFigure 2
  • EP2941399B1 patent drawingFigure 3~4

AI summary

The object of the invention is an elevator, which comprises at least an elevator car (3) arranged to move reciprocally in an elevator hoistway (1) and fitted on guide rails (2), a plurality of landing doors (1a, 1b) having landing door locks (12) openable e.g. with a service key, and a safety arrangement, which comprises means (7), which are arranged to form a safe space, preferably a working space, in the elevator hoistway (1) below the elevator car (3), access to which safe space is enabled via at least one landing door (1a) in the proximity of the base of the elevator hoistway (1), and/or a safe space, preferably a working space, above the elevator car (3), to which access is enabled via at least one landing door (1b) leading to the roof of the elevator car (3), and in which elevator the aforementioned safe space has a minimum height. The formation of each safe space is arranged to be implemented as a consequence of the opening occurring, e.g. with a service key, from a floor level of a landing door (1a, 1b) enabling access into the elevator hoistway (1).