Elevator Door Motor Brake for 50 mm Opening Limit Compliance

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Solution Overview

Problem

Existing elevator systems require frequent adjustments and maintenance to prevent elevator car door opening beyond a new mandatory 50mm limit, which is inconvenient due to the mechanical deterrent devices' location outside the car, conflicting with initiatives to reduce external maintenance.

Innovation Solution

An elevator door operating system featuring a door motor brake with a mechanical stop and braking disk, along with a biasing member to engage a pin with the door motor, preventing door opening when not at a landing floor, using an electromagnetic pin arrangement to control the door motor's operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical cam and roller deterrent device is used to prevent door opening, then the door opening is prevented, but the device requires frequent adjustment and maintenance from outside the car

Engineering Contradiction:

Improvedoor opening preventionVSAvoidmaintenance accessibility

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The brake assembly is extracted from external mounting and integrated inside the elevator car, specifically mounted to the door motor assembly. This relocation eliminates the need for external maintenance while maintaining the door opening prevention function through the brake pin engaging the brake disk.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The brake assembly is combined with the door motor assembly, integrating the deterrent function into an existing internal component. This merging allows the brake mechanism to be maintained from inside the car along with the door motor, eliminating separate external maintenance requirements.

Inventive Principle:

Principle #5Merging (Combining)

2Manufacturing precision

If the opening limit is reduced to 50mm, then regulatory compliance is achieved, but the typical deterrent device only prevents opening beyond 100mm

Engineering Contradiction:

Improveopening limit complianceVSAvoiddoor opening prevention effectiveness

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The brake pin is designed to engage with the brake disk at a specific localized position that corresponds to the 50mm opening limit. This precise local engagement point ensures the door cannot open beyond the regulated distance, providing exact compliance rather than the generic 100mm limitation of traditional devices.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The traditional cam and roller mechanical system is replaced with a brake disk and brake pin mechanism. This substitution allows for more precise control of the door opening limit through the brake engagement geometry, enabling accurate 50mm limitation while maintaining mechanical reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the deterrent device is located outside the elevator car, then door opening is prevented, but it conflicts with initiatives to reduce external maintenance activities

Engineering Contradiction:

Improvedoor opening preventionVSAvoidmaintenance location

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The brake assembly is designed to be maintained from inside the car along with the door motor assembly. This integration allows the same internal maintenance personnel and procedures to service both components, making the system self-sufficient regarding maintenance location and eliminating the need for separate external maintenance operations.

Inventive Principle:

Principle #25Self-service

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 door remains closed when not at a landing floor, meeting new regulatory opening limits without the need for external adjustments, thereby reducing maintenance and aligning with manufacturer goals of minimizing external maintenance activities.

Implementation Method 1

a biasing member to urge the pin into engagement with the elevator door motor

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

using an electromagnetic pin arrangement to control the door motor's operation

Methodology Applied

Scientific EffectElectromagnetism: Electromagnet

Data Source

PatentEP3334678B1Door motor brake

Publication Date: 2022.05.11 OTIS ELEVATOR CO

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AI summary

An elevator system includes a hoistway; and an elevator car (12) disposed in and drivable along the hoistway, the elevator car including: an elevator car door (38); an elevator door motor (40) operably connected to the elevator car door to selectably open and close the elevator car door; and a door motor brake (52) disposed at the elevator car door and selectably engageable with the elevator door motor to prevent operation of the elevator door motor thus preventing undesired opening and/or closure of the elevator car door.