Elevator Car Barrier Triggering Emergency Stop on Contact

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Solution Overview

Problem

Maintenance personnel in elevator systems face risks of injury during maintenance procedures due to accidental contact with moving elevator cars, particularly when the car is operated before completion of maintenance or when extending body parts beyond the car perimeter while it is moving.

Innovation Solution

An elevator car equipped with flexible and rigid barriers that extend from its surfaces, which upon contact with an object, rotate or flex to trigger an emergency brake, ensuring the elevator stops before impact, thereby creating a safety space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If barriers are made rigid to ensure structural strength, then safety protection capability is improved, but risk of serious impact injury to maintenance personnel worsens

Engineering Contradiction:

Improvesafety protection capabilityVSAvoidimpact injury risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The barrier structure changes its physical state from rigid to flexible upon detection of maintenance personnel presence, allowing it to deform and absorb impact energy while still providing safety protection. This parameter change resolves the contradiction by making the barrier rigid during normal operation but flexible during maintenance operations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The barrier transitions from a static rigid structure to a dynamic flexible structure based on operational conditions. When the elevator car is in maintenance mode, the barrier becomes flexible to prevent serious impact injury, while maintaining its protective function. This dynamic adaptation resolves the contradiction between structural strength and impact injury risk.

Inventive Principle:

Principle #15Dynamics

2Length of stationary object

If barriers extend further to increase safety space, then protection distance is improved, but stopping distance requirement worsens

Engineering Contradiction:

Improvesafety space distanceVSAvoidstopping distance

Core Design Contradiction:

Length of stationary objectVSLoss of time

Solution Approach 1:

The emergency brake is activated in advance when the flexible barrier detects maintenance personnel, initiating the stopping process before the elevator car reaches the barrier. This preliminary action allows the barrier to extend further while still providing adequate stopping distance, as the brake begins working before impact would occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The flexible barrier acts as an intermediary element that triggers the emergency brake system. When the barrier is displaced by maintenance personnel, it activates the brake, which then provides the stopping force. This intermediary mechanism allows the barrier to extend further while ensuring the stopping distance requirement is met through the brake system.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If flexible portion is made more compliant to reduce impact, then injury prevention is improved, but detection sensitivity worsens

Engineering Contradiction:

Improveimpact forceVSAvoidcontact detection sensitivity

Core Design Contradiction:

Object-affected harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The mechanical detection system is replaced with a magnetic detection system using a magnet and magnetic sensor. This substitution allows the flexible barrier to be highly compliant for impact reduction while the magnetic sensor provides sensitive detection of the barrier's displaced position, resolving the contradiction between compliance and detection sensitivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

A magnetic field is introduced as an intermediary between the flexible barrier and the detection system. The magnet attached to the flexible barrier interacts with the magnetic sensor to detect barrier displacement, allowing the barrier itself to remain highly compliant while the magnetic field provides sensitive detection capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 barriers effectively prevent serious injury to maintenance personnel by initiating an emergency stop of the elevator car, ensuring a safe working environment during maintenance procedures.

Implementation Method 1

The at least one barrier may comprise a flexible portion configured to flex upon contact with an object. The flexible portion may comprise polycarbonate, or other suitable material. The flexible portion can help to absorb an impact.

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP4328164B1Elevator car comprising at least one barrier

Publication Date: 2026.03.04 OTIS ELEVATOR CO

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AI summary

An elevator car (102) comprising at least one barrier (110) extending from an external surface (106, 108) of the elevator car (102) is disclosed. The elevator car (102) further comprises a switch (208) connectable in series with a safety chain circuit. The at least one barrier (110) is configured to be displaced from a first position (202) to a second position (204) upon contact with an object (120), such that the displacement to the second position (204) opens the switch (208) to initiate an emergency stop procedure of the elevator car (102).