Elevator Safety Brake Actuation Using Magnetic Overspeed Triggering

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Solution Overview

Problem

Traditional elevator overspeed safety systems rely on mechanical linkages that can be cumbersome and less efficient, whereas electrical overspeed safety systems without linkages pose challenges in simultaneous triggering of safety brakes during overspeed, overacceleration, and free fall events.

Innovation Solution

An electromechanical overspeed safety system utilizing a frame-mounted actuator with movable magnetic elements, where a rotating arm and biasing element work together to transition magnetic elements, generating repulsive and attractive forces to actuate safety brakes directly onto the guide rail, eliminating the need for mechanical linkages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical linkages are used to engage safety brakes simultaneously, then reliability of brake engagement is improved, but device complexity increases

Engineering Contradiction:

Improvereliability of brake engagementVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical linkages with an electromechanical actuator system that uses magnetic fields to simultaneously actuate safety brakes. The actuator includes a movable arm with a magnetic element that, when activated, generates magnetic attraction forces to engage brake elements on both guide rails simultaneously, eliminating the need for complex mechanical linkage mechanisms while maintaining reliable simultaneous brake engagement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If electrical overspeed safety systems without linkages are used, then device complexity is reduced, but reliability of simultaneous brake triggering deteriorates

Engineering Contradiction:

Improvedevice complexityVSAvoidreliability of simultaneous brake triggering

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent combines electrical control with electromechanical actuation. An electrical signal activates the electromechanical actuator, which then uses magnetic fields to simultaneously engage both safety brakes. This hybrid approach eliminates complex mechanical linkages while ensuring reliable simultaneous brake triggering through the magnetic coupling mechanism in the actuator.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electromechanical actuator serves as an intermediary between the electrical control system and the safety brakes. It receives an electrical activation signal and converts it into simultaneous mechanical action on both brakes through its magnetic field mechanism, bridging the gap between electrical control and mechanical brake engagement while maintaining reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If traditional mechanical linkage systems are used, then simultaneous brake engagement is achieved, but ease of operation deteriorates

Engineering Contradiction:

Improvesimultaneous brake engagementVSAvoidease of operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces complex mechanical linkage operations with an electromechanical actuator that can be activated by a simple electrical signal. The actuator's internal magnetic mechanism automatically coordinates the simultaneous engagement of both safety brakes, eliminating the need for operators to manage complex mechanical linkages while maintaining reliable simultaneous brake engagement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables efficient and controlled stopping of elevator cars during overspeed events by leveraging magnetic forces for simultaneous brake engagement, reducing reliance on friction and rail conditions, and simplifying the resetting process.

Implementation Method 1

a repulsive magnetic force is generated between the first magnetic element and the second magnetic element to urge the first magnetic element away from the second magnetic element

Methodology Applied

Scientific EffectMagnetic repulsion: Ion Repulsion/Attraction

Implementation Method 2

an attractive magnetic force is generated between the first magnetic element and the third magnetic element to urge the first magnetic element toward the third magnetic element

Methodology Applied

Scientific EffectMagnetic attraction: Ion Repulsion/Attraction

Data Source

PatentEP3636575B1Elevator safety actuator systems

Publication Date: 2023.03.29 OTIS ELEVATOR CO

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AI summary

Elevator systems are described that include a traveling component movable along a guide rail 309 and an overspeed safety system 300. The safety system includes a safety brake 314 connected to an electromechanical actuator 316. A safety brake element 334 of the safety brake is operable to engage with the guide rail to stop the traveling component. The electromechanical actuator includes a frame 310, a first magnetic element operably connected to the safety brake, a second magnetic element movably attached to the frame, and a third magnetic element fixedly attached to the frame. The second magnetic element is movable to urge the first magnetic element from a first position toward a second position. In the second position, the first magnetic element is located proximate the third magnetic element. As the first magnetic element transitions from the first position to the second position, the safety brake element is actuated into engagement with the guide rail.