Counter-Rotating Cutting Discs for Vegetation Fragmentation

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Solution Overview

Problem

Existing rotary cutters require significant power for operation and produce long plant fragments that are difficult to collect, making them inefficient for eliminating inter-row vegetation in crop fields.

Innovation Solution

A plant cutting module with multiple rotating cutting discs, where each disc has angularly offset radial knives that deploy and retract under centrifugal force, allowing for efficient fragmentation of plants with reduced power consumption and easy maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single rotary cutting disc is used, then the device complexity is low, but the plant fragmentation efficiency is insufficient and power consumption is high

Engineering Contradiction:
Improveplant fragmentation efficiencyVSAvoidnumber of cutting discs
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The single cutting disc is segmented into multiple cutting discs (at least four) arranged in sets, with each disc carrying angularly offset knives. This segmentation allows the system to process plants more efficiently through multiple cutting actions while maintaining manageable complexity through modular arrangement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cutting discs are arranged in vertical stacks (coaxial arrangement) rather than a single horizontal plane, adding a vertical dimension to the cutting mechanism. This multi-level arrangement increases fragmentation capability without proportionally increasing the horizontal footprint or operational complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If multiple cutting discs with angularly offset knives are used, then plant fragmentation efficiency improves, but the device complexity increases

Engineering Contradiction:
Improveplant fragmentation efficiencyVSAvoidarrangement of cutting discs and knives
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The complex cutting system is segmented into modular sets of coaxial discs, where each disc carries a specific number of angularly offset knives. This modular segmentation makes the complex arrangement more manageable and easier to maintain while preserving fragmentation efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of having knives fixed on a single disc plane, the invention inverts the approach by stacking multiple discs vertically with knives on different discs offset at different angles. This inverted spatial arrangement achieves comprehensive coverage and efficient fragmentation while distributing complexity across multiple simple modular units.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If radial knives are mounted on rotating discs, then plant cutting effectiveness improves, but safety concerns arise from high-speed rotating knives

Engineering Contradiction:
Improveplant cutting effectivenessVSAvoidsafety hazards from rotating knives
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention inverts the traditional rotary cutter design by mounting knives radially on rotating discs rather than having the entire disc rotate with fixed blades. The knives are mounted to rotate with the discs, creating a controlled cutting action that is effective yet safer due to the radial mounting geometry and controlled rotation.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The radial knives are designed to rotate dynamically with the discs rather than being fixed rigidly. This dynamic arrangement allows the knives to follow the rotational motion smoothly, reducing vibration and improving safety while maintaining cutting effectiveness through the continuous rotational contact with plant material.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If a single rotary cutter is used, then the device is simple to operate, but the collected plant material consists of long fragments that are difficult to manage

Engineering Contradiction:
Improveoperation simplicityVSAvoidplant fragment length
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The single cutting action is segmented into multiple sequential cutting actions by arranging at least four discs with angularly offset knives in coaxial stacks. This segmentation of the cutting process naturally produces shorter, more manageable plant fragments while the overall device remains simple to operate through centralized rotation control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By arranging cutting discs in vertical stacks rather than a single plane, the invention adds a vertical dimension to the cutting sequence. Plants passing through the cutter undergo multiple cutting actions at different vertical levels, producing shorter fragments without complicating the horizontal operation or material handling.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 module effectively fragments plants with lower power requirements, ensuring safe and easy operation while maintaining simplicity in construction, and facilitates easy collection of cut plant material.

Implementation Method 1

a possible retraction of the knives when encountering an obstacle and a deployment of the knives taking place under the simple action of the centrifugal force resulting from the rotation of the discs

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4338568B1Plant cutting module couplable to a frame of a soil working machine and a soil working machine comprising at least one cutting module
Publication Date: 2025.01.15 FEROTIN BENOÎT
  • EP4338568B1 patent drawingFigure 1
  • EP4338568B1 patent drawingFigure 2~3
  • EP4338568B1 patent drawingFigure 4~5

AI summary

Module (3) for cutting vegetation coupled to a chassis (2) of a soil-working machine (1), and comprising a box, at least one rotating cutting disc (5) and a device (6) for rotating the disc(s) (5), said box having in ground-supported use configuration an open front face (7), an opposite rear face, side faces (9), a bottom face (10) facing the soil to be worked and an opposite top face, and the axis of rotation of each disc (5) passing through the bottom (10) and top faces of the box.The disks (5) mounted together in rotation form two sets (11) of disks with each set (11) of disks comprising at least two superimposed parallel coaxial disks (5), the disks (5) of said sets (11) are counter-rotating disks (5) with each disk (5) of one set (11) coplanar with a disk (5) of the other set (11), each disk (5) carries at least one radial knife (12) mounted freely to rotate about an axis parallel to the axis of rotation of the disks (5), the knives (12) are angularly offset from one disk (5) to another of the same set (11) of disks (5) and from a disk (5) of one set (11) of disks (5) to a coplanar disk (5) of another set (11) of disks (5).