Electronic Safety Device for Portable Heat Engine Tools

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Solution Overview

Problem

Existing safety devices for portable heat engine tools, such as chainsaws, rely on mechanical means that are inefficient, prone to wear, and offer limited sensitivity and plane coverage, leading to slow response times and potential user injury during violent rebounds.

Innovation Solution

A safety device utilizing an independent electrical and/or electronic control system that processes acceleration data from accelerometers to directly control the engine's braking or ignition, allowing for fast, adjustable, and multi-planar response without moving parts, reducing wear and improving safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If mechanical means are used for safety devices, then the device structure is simple, but the response time is slow and the sensitivity is limited

Engineering Contradiction:
Improvedevice structureVSAvoidresponse time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent replaces the traditional mechanical safety device with an electronic control system comprising accelerometers, electronic control units, and electronic braking/ignition control. This substitution eliminates mechanical linkages and moving parts, enabling instantaneous detection and response to tool movement through electronic signal processing, thereby dramatically reducing response time while maintaining system simplicity through integrated electronic components.

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

2Ease of manufacture

If mechanical means are used for safety devices, then the device is easier to manufacture, but the device is prone to wear and has limited reliability

Engineering Contradiction:
Improvemanufacturing easeVSAvoiddevice reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent eliminates mechanical components that are subject to wear by using solid-state accelerometers and electronic control circuits. These electronic components have no moving parts, eliminating friction, wear, and mechanical failure modes. The system achieves enhanced reliability through electronic sensing and control while remaining manufacturable using standard electronic component assembly processes.

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

3Device complexity

If mechanical means are used for safety devices, then the device is simpler, but the sensitivity and plane coverage are limited

Engineering Contradiction:
Improvedevice complexityVSAvoidacceleration detection sensitivity
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs electronic accelerometers that can detect acceleration vectors with high precision in multiple planes (X, Y, and Z axes). These electronic sensors provide superior measurement sensitivity compared to mechanical mechanisms, enabling detection of subtle tool movements and vibrations. The electronic control unit processes signals from multiple accelerometers to determine tool orientation and movement in three-dimensional space, achieving comprehensive plane coverage without significantly increasing device complexity.

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

4Weight of moving object

If mechanical means are used for safety devices, then the device is lighter, but the inertia threshold is very high

Engineering Contradiction:
Improvedevice weightVSAvoidtrigger threshold sensitivity
Core Design Contradiction:
Weight of moving objectVSMeasurement precision

Solution Approach 1:

The patent uses electronic accelerometers with very low mass to detect tool movement, eliminating the need for heavy mechanical trigger mechanisms. The electronic sensing system can detect acceleration events with thresholds as low as 2000 m/s², providing highly sensitive detection without adding significant weight. The electronic control unit processes accelerometer signals to determine when safety thresholds are exceeded, enabling lightweight construction with high trigger sensitivity.

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

5Device complexity

If mechanical means are used for safety devices, then the device has fewer components, but the device can cause user injury during violent rebound

Engineering Contradiction:
Improvenumber of componentsVSAvoiduser injury risk
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical braking mechanisms that can cause harmful shocks to the user with electronic control of the engine's ignition and fuel injection systems. When a safety event is detected, the electronic control unit instantly cuts off ignition and fuel supply, stopping the engine without mechanical impact. This electronic approach eliminates the harmful rebound effects associated with mechanical braking while maintaining simple system architecture through integrated electronic control.

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

The solution enables instantaneous automatic stopping of tools during violent movements, enhancing safety by reducing response time, eliminating wear, and allowing adjustable sensitivity, while being more economical and lightweight compared to mechanical systems.

Implementation Method 1

at least one accelerometer (5) capable of measuring an acceleration on at least one plane or axis

Methodology Applied
Scientific EffectAcceleration detection: Accelerometer

Data Source

PatentEP2159018B1Safety device for portable tools with heat engine capable of stopping their operation following unexpected sudden and violent movements
Publication Date: 2013.07.24 PELLENC SA
  • EP2159018B1 patent drawingFigure 1A~1B
  • EP2159018B1 patent drawingFigure 1A'~1B'
  • EP2159018B1 patent drawingFigure 2~3

AI summary

Safety device for portable thermal engine tool allowing the near-instantaneous stopping of said tool's operation due to sudden and unforeseen violent movements, said device comprising at least one electronic accelerometer (5) allowing measurement of acceleration along at least one plane or axis (X, Y, Z), the output, or each output, of this accelerometer (5) being connected to an electrical and/or electronic control means (7), said electrical and/or electronic control means consisting of an electrical and/or electronic management board (7), this board and the accelerometer being supplied with electrical voltage by an electrical current generator (9) known in itself driven by the thermal engine, this electrical or electronic management board being configured to process the analog or digital electrical information from the accelerometer and to activate a means ensuring the near-instantaneous stopping of said thermal engine.