Leaf Shredder Cutting Element Spacing and Wear Control

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Solution Overview

Problem

Existing leaf shredding devices require regular maintenance and are prone to wear, making them less employable and less profitable due to collision between cutting elements, which affects their cutting ability and longevity.

Innovation Solution

A leaf shredding device with a spacer featuring spaced-apart teeth that controls the positioning of cutting elements, preventing collisions and improving wear resistance, along with adjustable and pivotable cutting elements to handle hard materials, and a centrifugal fan system for efficient leaf processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If cutting elements are positioned closely to improve cutting ability, then leaves can be shredded very finely, but cutting elements collide and wear increases

Engineering Contradiction:
Improvecutting precisionVSAvoidwear resistance
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

A spacer with spaced-apart teeth is introduced as an intermediary component between the first and second cutting elements. The teeth extend in the longitudinal direction of the shaft and control the relative positioning of the cutting elements, preventing direct collision while maintaining close proximity for effective cutting. This mediator allows the cutting elements to pass closely without colliding, resolving the contradiction between cutting precision and wear resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If cutting elements are made adjustable to handle hard materials, then adaptability improves, but device complexity increases

Engineering Contradiction:
Improvematerial handling capabilityVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The second cutting elements are made pivotable about a pivot axis, allowing them to move between a cutting position (within the path of first cutting elements) and a release position (outside the path). This dynamic positioning enables the cutting elements to adapt to different materials - handling hard materials by moving to the release position to avoid damage, while maintaining close positioning for normal leaf shredding operations.

Inventive Principle:
Principle #15Dynamics

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 device achieves improved cutting efficiency and reduced wear by preventing collisions between cutting elements, while the centrifugal fan system enhances leaf processing efficiency and prevents damage from hard materials, resulting in a more reliable and cost-effective solution for leaf management.

Implementation Method 1

a centrifugal fan, comprising a fan housing that houses a fan shaft rotatable about a second rotation axis and at least one fan blade that extends radially outwardly from the fan shaft and is rotatable about the second rotation axis by the fan shaft

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4420510A1Leaf shredding device, leaf processing system, and vehicle
Publication Date: 2024.08.28 GEBRR KRAAIJEVELD
  • EP4420510A1 patent drawingFigure 1
  • EP4420510A1 patent drawingFigure 2
  • EP4420510A1 patent drawingFigure 3

AI summary

Leaf shredding device, comprising a housing with at least one opening for input and/or output of leaves, a shaft mounted in the housing and rotatable about a rotation axis, at least one first cutting element that, at least in use, extends radially outwardly from the shaft and that is rotatable about the rotation axis, wherein a free end of the first cutting element distal from the shaft defines a path by rotation about the rotation axis, at least one second cutting element that is displaced from the at least one first cutting element in the longitudinal direction of the shaft and is located, at least in a cutting position thereof, within the path of the first cutting element as seen along the longitudinal direction of the shaft, such that the at least one first cutting element moves along the at least one second cutting element so as to cut leaves therebetween, the device further comprising a spacer with a base and at least one row of spaced-apart teeth extending from the base and away from the shaft, the row extending substantially in longitudinal direction of the shaft, and the spacer being located outside the path of the first cutting element and positioned such that each of the at least one second cutting elements is located, at least in the cutting position thereof, between two of the spaced-apart teeth.