Elevator Locking Mechanism Access Control via Removable Plug

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Solution Overview

Problem

Elevator systems lack effective mechanisms to prevent unauthorized access to locking mechanisms during maintenance operations, posing safety and regulatory concerns.

Innovation Solution

The elevator access system includes a bushing with a keyway, a plunger, and a removable plug that moves the plunger and lever into positions to control access, with an optional elevator safety chain switch to break the safety chain, ensuring secure access and operation only by authorized personnel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

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

Engineering Contradiction:

Improveaccess to locking mechanismsVSAvoidunauthorized access

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The locking mechanism is segmented into multiple components: a removable plug that blocks access, a plunger that can be actuated, and a lever that operates the lock. The plug is separated from the main locking mechanism, allowing it to be removed only when needed for maintenance, thereby preventing unauthorized access while enabling authorized operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A removable plug acts as an intermediary element between the external environment and the locking mechanism. This plug physically blocks the keyway and prevents direct access to the plunger, serving as a mediator that can be removed by authorized personnel to enable maintenance operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If access to locking mechanisms is restricted to prevent unauthorized operation, then safety is improved, but ease of operation for authorized personnel deteriorates

Engineering Contradiction:

ImprovesafetyVSAvoidaccess during maintenance

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The removable plug is pre-installed in the keyway to block access before any maintenance operation begins. This preliminary blocking action ensures safety by default, and authorized personnel can easily remove the plug when they need to perform maintenance, thus maintaining both safety and ease of operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system transitions from a static blocked state (plug inserted) to a dynamic accessible state (plug removed) based on operational needs. The plug can be easily inserted or removed to change the accessibility of the locking mechanism, providing dynamic control over safety and ease of operation.

Inventive Principle:

Principle #15Dynamics

3Object-affected harmful factors

If a removable plug is installed to block access to the plunger, then unauthorized access is prevented, but device complexity increases

Engineering Contradiction:

Improveunauthorized access preventionVSAvoidaccess system structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The safety blocking function is extracted as a separate removable plug component rather than being integrated into the main locking mechanism. This extraction allows the plug to be independently manufactured, installed, and removed, simplifying the overall system while effectively preventing unauthorized access.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The removable plug is designed as a simple, inexpensive component that can be easily manufactured and replaced. It serves as a temporary blocking element that is removed when maintenance is needed and can be replaced afterward, providing an economical solution to prevent unauthorized access without adding significant complexity.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

4Ease of operation

If the plunger is made accessible to operate the lever, then ease of operation is improved, but safety risks from unauthorized operation increase

Engineering Contradiction:

Improvelever operationVSAvoidunauthorized operation

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The removable plug is inserted into the keyway to preliminarily prevent any action on the plunger before authorization occurs. This preliminary anti-action blocks unauthorized operation, and only when the plug is removed by authorized personnel can the plunger be actuated to operate the lever, thus balancing ease of operation with safety.

Inventive Principle:

Principle #9Preliminary anti-action

Data Source

PatentUS11136217B2Elevator access systems for elevators

Publication Date: 2021.10.05 OTIS ELEVATOR CO

AI summary

Elevator access systems are provided. The elevator access systems include a bushing having a keyway, a plunger disposed within the bushing and movable relative thereto, a lever operably connected to the plunger, and a removable plug located within the keyway of the bushing, wherein the removable plug urges the plunger and the lever into a first position, and upon removal of the removable plug, the plunger and the lever move to a second position, wherein in the second position the plunger is accessible to operate the lever.