Elevator Access Control System for Safe Maintenance Positioning

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Solution Overview

Problem

Elevator maintenance poses safety risks due to unauthorized access and the need for technicians to enter hazardous elevator shafts, while existing systems lack efficient mechanisms to restrict access and facilitate maintenance from safer locations.

Innovation Solution

The implementation of an elevator control system that allows authorized personnel to activate a maintenance mode, automatically positioning the elevator car relative to a landing to enable access to specific parts of the elevator car, such as the lintel or sill, without requiring entry into the shaft, using an access control module to manage locking mechanisms and prevent unauthorized access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If locking mechanisms are made easily accessible in elevator cars for maintenance operations, then maintenance ease is improved, but unauthorized access and safety risks increase

Engineering Contradiction:
Improvemaintenance accessVSAvoidunauthorized access risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The access prevention device transitions between locked and unlocked states dynamically based on system mode. In normal operation, the device locks the mechanism; in maintenance mode with proper authorization, it unlocks to allow access. This dynamic state change resolves the contradiction by making the system secure during regular use but accessible when needed for maintenance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

An access control module acts as an intermediary between maintenance personnel and the locking mechanism. It verifies authorization credentials and controls the state of the access prevention device, serving as a mediator that allows legitimate access while blocking unauthorized attempts, thus resolving the security-access contradiction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If technicians can access elevator shaft for maintenance operations, then maintenance capability is improved, but safety risks from hazardous positions increase

Engineering Contradiction:
Improvemaintenance capabilityVSAvoidshaft entry danger
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary positioning of the elevator car to predetermined maintenance positions before maintenance work begins. The car is automatically conveyed to specific positions that provide access to different components (lintel, sill, etc.), eliminating the need for technicians to enter the shaft and perform manual positioning, thus resolving the safety-capability contradiction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual mechanical positioning (technicians physically moving the car or positioning themselves in the shaft) with an automated control system that uses electrical signals to position the elevator car. This substitution eliminates the hazardous manual shaft entry while maintaining full maintenance capability.

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

3Reliability

If access prevention device is always enabled for security, then safety is improved, but maintenance access becomes difficult

Engineering Contradiction:
Improveaccess securityVSAvoidmaintenance accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The access prevention device dynamically changes its state based on operational context. It maintains a locked state during normal operation for security, but transitions to an unlocked state when the system is in maintenance mode with proper authorization. This dynamic behavior resolves the contradiction between constant security and maintenance accessibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameter of the access prevention device from 'locked' to 'unlocked' based on the system mode and authorization status. This parameter change allows the device to maintain high security during normal operation while becoming accessible during authorized maintenance operations, resolving the contradiction between security and accessibility.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If multiple access points are provided for maintenance, then maintenance flexibility is improved, but system complexity increases

Engineering Contradiction:
Improvemaintenance flexibilityVSAvoidaccess control system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A single access control module serves multiple functions: it authenticates maintenance personnel, controls the access prevention device, positions the elevator car to appropriate maintenance positions, and manages different maintenance modes. This multi-functional approach provides maintenance flexibility across multiple access points while avoiding the complexity of separate control systems for each function.

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

Data Source

PatentEP3360837B1Maintenance access system for elevators
Publication Date: 2022.04.20 OTIS ELEVATOR CO
  • EP3360837B1 patent drawingFigure 1
  • EP3360837B1 patent drawingFigure 2
  • EP3360837B1 patent drawingFigure 3

AI summary

Methods and system for operating an elevator include receiving input regarding a maintenance action at an access control module, the input including a first predetermined maintenance position, the first predetermined maintenance position being a position of the elevator car within an elevator shaft relative to a landing, conveying an elevator car to the first predetermined maintenance position, disabling an access prevention device of a landing door lock, and opening a landing door at the landing to enable access to the elevator car positioned at the first predetermined maintenance position.