Elevator Door Lock Safety Device with Expanding Members

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Solution Overview

Problem

Elevator systems lack effective safety devices to prevent unauthorized access to locking mechanisms, which is a safety concern, especially during maintenance operations or emergencies like fires.

Innovation Solution

The elevator door lock safety device features a base with expanding extension members, an actuation device, and optional friction members that secure the device within the door lock, preventing removal and ensuring unauthorized access is blocked by increasing the separation distance between the members upon actuation, forming a friction fit with the door lock.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the locking mechanism is made easily accessible for maintenance operations, then the ease of operation is improved, but the security against unauthorized access deteriorates

Engineering Contradiction:
Improveaccessibility for maintenanceVSAvoidsecurity against unauthorized access
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking mechanism is divided into two functional parts: an accessible exterior portion for authorized maintenance operations, and an interior portion that requires insertion and actuation of the safety device. This segmentation allows routine maintenance while preventing unauthorized access to critical interior components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The safety device acts as an intermediary element between the exterior environment and the interior locking mechanism. When inserted and activated, it expands to block access to the interior portion, serving as a mediator that enables controlled access - allowing authorized personnel to operate the lock while preventing unauthorized individuals from accessing the interior components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the safety device is designed to prevent access to the locking mechanism, then the security is improved, but the ease of operation for authorized personnel deteriorates

Engineering Contradiction:
Improvesecurity against unauthorized accessVSAvoidaccessibility for maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The safety device is designed to be inserted into the locking mechanism before maintenance operations begin. This preliminary action establishes security controls in advance, allowing authorized personnel to then operate the lock through the designated exterior interface without needing to access the interior, thus maintaining both security and operational ease.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the expanding extension members are designed to increase separation distance upon actuation, then the security against removal is improved, but the device complexity increases

Engineering Contradiction:
Improvesecurity against removalVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The extension members transition from a static, compact configuration to a dynamic, expanded state upon actuation. This dynamic behavior allows the device to maintain a low-profile inserted state during installation, then automatically expand to engage with the interior surfaces and increase separation distance, providing secure anti-removal functionality without requiring a permanently complex structure.

Inventive Principle:
Principle #15Dynamics

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 provides a secure mechanism to prevent unauthorized access to elevator door locks, allowing authorized personnel to perform maintenance safely without risking improper operation or access during emergencies.

Implementation Method 1

a friction member located on each of the first and second expanding extension members, wherein the friction member is configured to provide friction engagement with an engagement surface of a door lock

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3293138B1Elevator door lock safety device
Publication Date: 2019.08.07 OTIS ELEVATOR CO
  • EP3293138B1 patent drawingFigure 1
  • EP3293138B1 patent drawingFigure 2
  • EP3293138B1 patent drawingFigure 3A~3B

AI summary

Elevator door lock safety devices (300; 400; 500; 600; 700; 900) including a base (408), a first expanding extension member (410a; 510a; 910a) extending from the base (408), the first expanding extension member (410a; 510a; 910a) having a first exterior surface (522a) and a first interior surface (416a), a second expanding extension member (410b; 510b; 910b) extending from the base (408) and opposing the first expanding extension member (410a; 510a; 910a), the second expanding extension member (410b; 510b; 910b) having a second exterior surface (522b) and a second interior surface (416b), wherein a separation distance (412; 512) is defined between the first and second interior surfaces (416a; 416b), an actuator aperture (420; 920) formed within the first expanding extension member (410a; 510a; 910a) and extending through the first expanding extension member (410a; 510a; 910a) from the first exterior surface (522a) to the first interior surface (416a), and an actuation device (406; 906) passing through the actuator aperture (420; 920), wherein actuation of the actuation device (406; 906) actuates the elevator door lock safety device (300; 400; 500; 600; 700; 900) from a first state to a second state, wherein the separation distance (412; 512) is greater in the second state than in the first state.