Forklift Lifting Height Detection Using Non-Volatile Memory and Hall Sensors

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Solution Overview

Problem

Existing industrial truck systems face reliability and cost-effectiveness issues in providing accurate information about the current lifting height of load-carrying means, particularly due to the sensitivity of traditional switches to vibrations and temperature fluctuations, which can lead to malfunctions, especially in cold storage environments.

Innovation Solution

The method employs a non-volatile memory to store lifting height information when the truck is switched off, combined with a switching element that changes state when the load-carrying element passes a predetermined height, allowing for immediate access to the current lifting height upon startup, using sensors like magneto-resistive Hall sensors for reliable detection, and error messaging for malfunction detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If reed switches are used for lifting height detection to maintain switching state independently of power supply, then lifting height information is retained when truck is switched off, but the system becomes susceptible to vibrations and temperature fluctuations causing malfunctions

Engineering Contradiction:
Improvelifting height information retentionVSAvoidswitching element reliability
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent replaces mechanical/reed switches with a sensor system that uses magnetic field detection (Hall effect or similar non-contact sensing) combined with electronic memory storage. This substitution eliminates the mechanical vulnerability to vibrations while maintaining the ability to retain lifting height information when the truck is switched off.

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

Solution Approach 2:

The patent changes the operating parameters of the detection system by using sensors that are insensitive to vibrations and temperature fluctuations. The switching element is designed to change state based on magnetic field changes rather than mechanical contact, making the system more reliable in cold storage environments while still retaining information independently of power supply.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If traditional lifting height switches are used, then the system is simple in structure, but the switches are sensitive to vibrations and temperature fluctuations leading to malfunctions

Engineering Contradiction:
Improveswitching element structureVSAvoidswitching element reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces traditional mechanical switches with a sensor-based system that uses magnetic field detection. This maintains relative structural simplicity while dramatically improving reliability by eliminating mechanical components that are sensitive to vibrations and temperature changes.

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

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the lifting height position and the switching element. This magnetic field mediator allows the switching element to detect position changes without direct mechanical contact, thereby reducing sensitivity to vibrations and temperature fluctuations while maintaining system simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If the truck is switched off to save energy, then power consumption is reduced, but lifting height information is lost and the truck cannot be used immediately upon startup

Engineering Contradiction:
Improvepower consumptionVSAvoidtime to become operational
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent performs the action of storing lifting height information in non-volatile memory before the truck is switched off. This preliminary action ensures that the information is preserved and immediately available upon startup, eliminating the need for initial movement cycles and reducing the time to become operational while maintaining energy savings during the off-state.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces non-volatile memory as an intermediary storage medium that retains lifting height information independently of power supply. This intermediary allows the system to maintain operational readiness without continuous power consumption, resolving the contradiction between energy savings and immediate operational capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach provides reliable and cost-effective determination of the current lifting height, reducing the need for initial movement cycles and enhancing operational safety by ensuring accurate information is available immediately upon startup, while being resistant to environmental factors like temperature fluctuations.

Implementation Method 1

Reading out information about the lifting height stored in a non-volatile memory when the truck was last switched off

Methodology Applied
Scientific EffectNon-volatile memory storage:

Implementation Method 2

a switching element that does not have a function that maintains its switching state independently of an energy supply and is arranged so that its switching state changes when a load-carrying element of the industrial truck passes a predetermined lifting height

Methodology Applied
Scientific EffectSwitching element state change:

Implementation Method 3

using sensors like magneto-resistive Hall sensors for reliable detection

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2390222B1Method for providing information about a current hoisting height and industrial truck for same
Publication Date: 2013.09.04 JUNGHEINRICH AG
  • EP2390222B1 patent drawingFigure 1
  • EP2390222B1 patent drawingFigure 2
  • EP2390222B1 patent drawingFigure 3

AI summary

Method for providing information about the current lifting height of a load-carrying device (12) of a forklift truck comprising the following steps: • Reading information about the lifting height stored in a non-volatile memory (52) when the forklift truck was last switched off, • Determining information about the current lifting height based on the information about the lifting height read out when the forklift truck was last switched off and the switching state of a switching element (18) that does not have a function to maintain its switching state independently of a power supply and is arranged such that its switching state changes when the load-carrying device (12) of the forklift truck passes a predetermined lifting height (26).