Elevator Door Interlock Linkage and Vane Mechanism

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Solution Overview

Problem

Elevator car door interlocks face challenges in ensuring doors remain closed during movement and efficiently open at landings, with existing solutions not adequately addressing the need for precise control over door gap and emergency unlocking mechanisms.

Innovation Solution

The elevator car door interlock system employs a mechanism with vanes, link assemblies, and a drive mechanism that allows the first and second vanes to move relative to each other, using pivot pins and a pawl assembly to control the door latch, enabling secure locking and unlocking based on the elevator's position, with a biasing member ensuring functionality even when power is lost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex interlock mechanism is used to ensure precise door gap control and secure locking, then door safety and security are improved, but device complexity increases

Engineering Contradiction:
Improvedoor safetyVSAvoidinterlock mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The interlock mechanism is divided into separate functional components: a first link assembly controlling door latch engagement, a second link assembly managing gap control, and a ratchet-pawl mechanism for position locking. This segmentation allows each component to perform its specific function independently, improving overall reliability while maintaining manageable complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fixed plate serves as an intermediary element that provides a stable reference frame for the moving link assemblies. The fixed plate mediates between the motor-driven actuation and the door latch mechanism, ensuring precise control of door gap and latch engagement without requiring the entire mechanism to be overly complex

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a motor-driven mechanism with multiple linkages is used to control door latch engagement and gap, then door control precision is improved, but device complexity increases

Engineering Contradiction:
Improvedoor gap controlVSAvoidlinkage mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The ratchet mechanism employs asymmetric tooth geometry on the rack, with teeth configured to allow movement in one direction while preventing reverse movement. This asymmetric design enables precise unidirectional control of door gap and latch position without requiring complex bidirectional actuators or feedback mechanisms, simplifying the overall control system

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The link assemblies are designed with pivot points and sliding connections that allow dynamic adjustment of door latch engagement and gap control based on operational conditions. The mechanism transitions between locked and unlocked states through controlled movement of the linkages, enabling adaptive response to different door positions and forces applied

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a ratchet and pawl mechanism is used for emergency unlocking, then ease of operation in emergencies is improved, but device complexity increases

Engineering Contradiction:
Improveemergency unlockingVSAvoidratchet-pawl mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The ratchet-pawl mechanism is designed to be manually operable without requiring external power sources or complex electronic controls. The pawl can be disengaged from the ratchet teeth through simple manual manipulation, allowing occupants to unlock doors in emergency situations using only mechanical force, eliminating the need for batteries, motors, or electronic systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The ratchet and pawl components are designed as simple, robust mechanical elements that can be manufactured at low cost using basic materials. The mechanism prioritizes reliability and ease of manual operation over longevity or precision, accepting that these simple mechanical components may wear over time but providing adequate service life for emergency egress functionality

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

This solution ensures the elevator car doors remain closed during movement and efficiently open at landings, providing secure locking and unlocking functionality, including emergency unlocking, while maintaining a controlled door gap and ensuring operation even in power loss scenarios.

Implementation Method 1

a biasing member connected to the first vane and at least one of the second vane and a second link second end. In some embodiments, the biasing member is arranged to move the second vane such that the second intermediate link pivots about the fifth pivot and the first intermediate link pivots about the second pivot such that the latch link pivots the door latch to disengage the lock member.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3693318B1Elevator car door interlock
Publication Date: 2023.12.27 OTIS ELEVATOR CO
  • EP3693318B1 patent drawingFigure 1
  • EP3693318B1 patent drawingFigure 2~3
  • EP3693318B1 patent drawingFigure 4~5

AI summary

An elevator car door interlock (141) includes a first link assembly (157) having a first intermediate link (201) movably connected to a first vane (153), and a first link (203) having a first link first end (213) pivotally connected to the first intermediate link (201) and a first link second end (215) pivotally connected to a second vane (155). A latch assembly (165) includes a door latch (263) pivotally connected to the baseplate (151) wherein responsive to operation of a drive mechanism (135) that is drivably connected to the first link second end (215), while an interlock roller (293) engages at least one of the first vane (153) and the second vane (155), the first vane (153) moves towards the second vane (155) and the door latch (263) pivots to unlock an elevator car door (131).