Elevator Overspeed Governor Linkage With Spring Force Reduction

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Solution Overview

Problem

Car mounted overspeed governors in elevators experience increased impact forces at higher speeds, leading to potential component damage and the need for heavier, more costly mechanical connections to withstand these forces.

Innovation Solution

A force reduction mechanism is introduced between the overspeed governor and the safety gear, utilizing components like torsion springs, linear springs, or helical springs to absorb and distribute the impact force over a longer period, reducing the magnitude of the shock transmitted to the safety gear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If car mounted overspeed governor is used, then response time is improved, but impact force increases

Engineering Contradiction:
Improveresponse timeVSAvoidimpact force
Core Design Contradiction:
Loss of timeVSForce

Solution Approach 1:

A force reduction mechanism is introduced as an intermediary component between the overspeed governor and the safety gear. This mechanism includes a force reduction lever connected to the governor linkage, which acts as a mediator to reduce the impact force transmitted from the governor to the safety gear while preserving the quick response time advantage of car-mounted governors.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The force reduction mechanism changes the force parameter by using a lever system with different arm lengths. The force reduction lever has a first arm connected to the governor linkage and a second arm connected to the safety gear linkage, creating a mechanical advantage that reduces the impact force magnitude while maintaining the rapid actuation response.

Inventive Principle:
Principle #35Parameter changes

2Strength

If heavier mechanical connections are used, then strength is improved, but device complexity increases

Engineering Contradiction:
Improvemechanical connection strengthVSAvoidmechanical connection complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The force reduction lever serves as an intermediary that reduces the force magnitude before it reaches the safety gear connections. This allows the use of lighter, simpler mechanical connections that are sufficient for the reduced force level, rather than requiring heavy-duty connections designed for full impact forces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mechanical connection system is segmented into multiple components: the governor linkage, the force reduction lever, and the safety gear linkage. This segmentation allows each component to be optimized for its specific force level, resulting in simpler, lighter individual parts compared to a single heavy-duty connection system.

Inventive Principle:
Principle #1Segmentation

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 reduces the impact force on the safety gear, allowing for lighter and less costly mechanical connections without compromising reliability, as the force reduction mechanism spreads the impact force over time, thereby minimizing the stress on the governor and safety gear components.

Implementation Method 1

A force reduction mechanism is introduced between the overspeed governor and the safety gear, utilizing components like torsion springs, linear springs, or helical springs to absorb and distribute the impact force over a longer period, reducing the magnitude of the shock transmitted to the safety gear.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2855325B1Car mounted overspeed governor actuation device
Publication Date: 2021.08.25 OTIS ELEVATOR CO
  • EP2855325B1 patent drawingFigure 1
  • EP2855325B1 patent drawingFigure 2
  • EP2855325B1 patent drawingFigure 3

AI summary

A device for reducing an actuation force spike in an elevator car safety system. The device includes an elevator car mounted overspeed governor, a safety gear, a safety lever, and a force reducing mechanism. The force reducing mechanism is connected in a series relationship with the safety lever between the overspeed governor and the safety gear.