Pruning Shear Guide Pin and Magnetic Sensor for Blade Alignment

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Solution Overview

Problem

Existing pruning shears suffer from poor guidance of the moving cutting blade due to wear, leading to a decrease in cut quality, and lack precision in triggering the cutting cycle, with inadequate adjustment for wear and opening amplitude.

Innovation Solution

The pruner features a guide pin engaged in an adjusted manner with a threaded seat in the counter-blade, immobilized by a pin, and equipped with a smooth surface for a guide ring, allowing for precise adjustment and replacement of cutting elements, along with a magnetic sensor system for improved precision and adjustable blade alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the guide shaft is mounted in a rotationally guided manner within a bearing formed in the head, then the blade can move smoothly during cutting, but wear increases over time leading to increased play and poor guidance of the moving cutting blade

Engineering Contradiction:
Improvesmooth blade movementVSAvoidblade guidance quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the traditional mechanical bearing system with a magnetic field-based positioning system. A magnet is embedded in the trigger mechanism, and a Hall effect sensor detects its position, eliminating the need for direct mechanical contact between the guide shaft and bearing. This substitution prevents wear-induced play while maintaining smooth blade movement through magnetic field sensing of the trigger's angular position.

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

Solution Approach 2:

The patent introduces a Hall effect sensor as an intermediary element between the mechanical components. Instead of directly measuring the trigger position through mechanical contact, the sensor detects changes in the magnetic field generated by the magnet on the trigger, providing precise positional information without mechanical wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Extent of automation

If the trigger position is measured using a magnet and Hall effect sensor to control the angular position of the moving blade, then the cutting cycle can be controlled, but the position is deduced rather than measured directly leading to less accuracy

Engineering Contradiction:
Improveautomatic cutting cycle controlVSAvoidtrigger position measurement accuracy
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The patent replaces indirect mechanical position deduction with direct magnetic field sensing. The Hall effect sensor directly measures the angular position of the trigger by detecting the magnetic field of the embedded magnet, providing precise measurement rather than deducing position from other parameters.

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

3Stability of the object's composition

If the counter-blade is rigidly fixed to the head, then the structure is simple and stable, but wear cannot be compensated and blade overlap value cannot be adjusted

Engineering Contradiction:
Improvestructural stabilityVSAvoidblade overlap adjustment capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent transforms the static, rigid connection between the counter-blade and head into a dynamic, adjustable system. The guide shaft with threaded section allows the counter-blade position to be adjusted along the shaft, enabling compensation for wear and adjustment of blade overlap while maintaining structural stability through the secure threaded connection.

Inventive Principle:
Principle #15Dynamics

4Strength

If the guide shaft is secured by a pin engaged in holes in the head and counter-blade, then the counter-blade is firmly immobilized, but replacement of the counter-blade requires dismantling multiple components

Engineering Contradiction:
Improvecounter-blade immobilizationVSAvoidcounter-blade replacement ease
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The patent segments the fastening system into modular components: the guide shaft with integrated threaded section, the adjustable counter-blade, and the locking pin. This segmentation allows the counter-blade to be adjusted by rotating it on the threaded shaft, and replacement to be facilitated by removing just the locking pin and guide shaft, rather than dismantling the entire assembly.

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 design enhances the guidance and precision of the cutting blade, facilitates easy replacement and adjustment for wear compensation, and provides accurate blade alignment, resulting in improved cut quality and adaptability for various pruning tasks.

Implementation Method 1

on their carcass, opposite the magnet, they receive a Hall effect sensor to measure the amplitude of the magnetic field of the magnet and deduce the angular position of the trigger

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2353366B1Branch shear for cutting plants
Publication Date: 2012.03.21 INFACO
  • EP2353366B1 patent drawingFigure 1~2
  • EP2353366B1 patent drawingFigure 3~5

AI summary

The shear has a hollow gripping handle that is provided with a distal end of a support end (5) carrying a counter blade (60). A motorized blade is articulated with respect to the counter blade, where the motorized blade is mounted on a guiding axle (7). The guiding axle is engaged in a bore (50) in an adjusted manner, where the bore is formed in the head. A threaded bearing (70) is engaged in a crossing threading (60a) formed in the counter blade, where the counter blade is immobilized with respect to the head by a pin. The pin is engaged in a piercing of the head and the counter blade.