Elevator Car Safety Device for Drift Immobilization

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Solution Overview

Problem

Elevator cars stopped at floor landings are at risk of drifting due to faulty transmission components, posing safety hazards during loading and unloading, as existing remote maintenance technologies lack effective immobilization methods.

Innovation Solution

A safety device comprising a brake member and a parachute device, with a cabin positioning sensor and control circuit that activates the parachute to instantly immobilize the car if it drifts beyond a predetermined distance from the marked position, ensuring safe stopping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If remote maintenance is implemented without on-site operator presence, then maintenance efficiency is improved, but safety reliability deteriorates due to inability to physically check transmission components

Engineering Contradiction:
Improvemaintenance efficiencyVSAvoidsafety reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system enables self-monitoring through automated sensors that detect car position and brake status, allowing the elevator to identify and report its own anomalies without requiring continuous human presence for inspection

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The positioning sensor provides continuous feedback to the control circuit about the car's position relative to the mark, enabling real-time monitoring and automatic activation of safety devices when drift exceeds thresholds

Inventive Principle:
Principle #23Feedback

2Reliability

If multiple mechanical elements are used for car immobilization, then stopping reliability is improved, but system complexity increases due to multiple potential failure points

Engineering Contradiction:
Improvestopping reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The parachute device serves as a pre-positioned safety backup that activates automatically if the primary brake system fails, providing a second line of defense without requiring complex real-time decision-making or additional mechanical components during normal operation

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If brake system is relied upon for car immobilization, then device simplicity is maintained, but safety margin decreases due to risk of brake drift under load

Engineering Contradiction:
Improvedevice simplicityVSAvoidsafety margin
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The positioning sensor acts as an intermediary that monitors the car's position and translates mechanical drift into an electrical signal that triggers the safety device, creating a bridge between the mechanical brake system and the parachute safety mechanism

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP1752408B1Safety method and device for maintaining the level of an elevator car at a landing
Publication Date: 2013.01.16 SODIMAS
  • EP1752408B1 patent drawingFigure 1~2

AI summary

The method involves detecting a positioning of an elevator car (5) with respect to a positioning mark (19) at the level of the car at each landing of floor during controlling the stopping of the car at the landing. Operation of a car safety device (13) is controlled for instantaneously stopping the car in a safety position in case of drift of the car below or above the mark and beyond a determined distance of the drift permitted to the mark. An independent claim is also included for a safety device for maintaining elevator car at stop in landing.