Hydraulic Elevator Force Measurement Without Locking

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Solution Overview

Problem

Existing methods for testing the functionality of hydraulic elevators are cumbersome, imprecise, and prone to damage, particularly when determining the maximum lifting force required to lift a nominal load, as they often require structural parameters and locking devices.

Innovation Solution

A method involving a force measuring device to measure the weight force and pressure of an elevator car, plotting these against a straight line to determine the maximum weight force without locking the car to the shaft, using a pressure measuring device and computer for accurate calculations, and optionally using an optical distance sensor to assess hydraulic tightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a locking device is used to lock the car in the shaft to measure lifting force, then the measurement of maximum lifting force becomes possible, but the locking device and guide rails may be damaged by the lifting force

Engineering Contradiction:
Improvemeasurement of maximum lifting forceVSAvoiddamage to locking device and guide rails
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A force measuring device is introduced as an intermediary element between the elevator car and the shaft floor. This mediator allows the measurement of lifting forces without requiring direct mechanical connection or locking of the car to the shaft, thereby avoiding damage to locking devices and guide rails while enabling accurate force measurement through the measuring device's sensors

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical locking system with a force measurement system. Instead of using mechanical locks to hold the car and measure force through the locking mechanism, the system uses sensors in the force measuring device to detect lifting forces, substituting mechanical interaction with electronic measurement that does not cause damage

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If structural parameters like working piston area are used to calculate maximum force from pressure, then the measurement can be performed with existing equipment, but the determination becomes cumbersome and imprecise

Engineering Contradiction:
Improveuse of existing equipmentVSAvoiddetermination of maximum force
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The force measuring device performs self-calibration and automatic determination of maximum lifting force through its control unit. The device autonomously processes pressure measurements, applies the straight-line evaluation method, and calculates the maximum force without requiring manual input of structural parameters or complex calculations by the operator, making the process both precise and easy to perform

Inventive Principle:
Principle #25Self-service

3Measurement precision

If the car is locked in the shaft with a locking device to measure lifting force, then the force can be measured directly, but the procedure becomes complex and time-consuming

Engineering Contradiction:
Improvedirect measurement of lifting forceVSAvoidtesting speed and simplicity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts the force measurement function from the mechanical locking system and places it in a dedicated force measuring device positioned in the shaft pit. This separation allows the measurement to occur without engaging locking mechanisms, eliminating the complexity and time required for locking operations while maintaining direct force measurement capability through the measuring device's sensors

Inventive Principle:
Principle #2Taking out (Extraction)

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 method allows for quick, accurate, and easy assessment of elevator functionality without requiring structural parameters or locking devices, providing immediate determination of the maximum weight force and hydraulic device condition, facilitating efficient testing with minimal equipment and effort.

Implementation Method 1

measuring a weight force F1 exerted by the car on the force measuring device

Methodology Applied
Scientific EffectForce measurement:

Implementation Method 2

measuring a first pressure P1 prevailing in the hydraulic device

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 3

a hydraulic pump and a working piston for moving an elevator car

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP2251294B1Method and assembly for testing that a hydraulic lift is functioning correctly
Publication Date: 2012.05.09 DEKRA TESTING & INSPECTION GMBH
  • EP2251294B1 patent drawingFigure 1
  • EP2251294B1 patent drawingFigure 2

AI summary

The method involves setting a car on a force measuring equipment and measuring weight (F1) exerted by the car on the force measuring equipment. A pressure (P1) corresponding to the weight is measured. The car is lifted from the equipment and moved upto a preset holding point, and another pressure is measured. A connection between a hydraulic pump and a working piston is broken and a maximum pressure (P3) in the pump is measured. A maximum weight (F2) corresponding to the maximum pressure is determined from a line, which runs through the measured pressures and the weight.