Variable Stiffness Curtain for Crop Leaning

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Solution Overview

Problem

Existing cutter implements struggle to efficiently cut tall, rigid crops without hindering cutting performance, as they require a stronger bending force to lean the crops forward effectively.

Innovation Solution

A cutter implement with a curtain that includes a stiffness control feature, allowing for variable vertical stiffness that increases with the bend angle of the curtain, effectively controlling the force applied to the crop to achieve optimal leaning and cutting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a curtain is used to lean crop material forward, then cutting performance is improved, but the curtain requires strong bending force that may over-bend rigid crops

Engineering Contradiction:
Improvecutting performanceVSAvoidbending force
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The curtain's stiffness is made variable rather than fixed. The vertical stiffness increases with the bend angle, allowing the curtain to be compliant at low angles and stiffer at high angles. This dynamic property enables the curtain to effectively lean both flexible and rigid crops without applying excessive force that would cause over-bending.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The physical parameter of vertical stiffness is changed as a function of bend angle. By designing the curtain structure (with varying thickness, density, or construction) so that stiffness increases with deflection, the system adapts its mechanical properties to the operating conditions, providing optimal force characteristics for different crop types and bend angles.

Inventive Principle:
Principle #35Parameter changes

2Strength

If vertical stiffness of the curtain is increased to handle rigid crops, then leaning capability is improved, but flexible crops may be damaged by excessive stiffness

Engineering Contradiction:
Improveleaning capabilityVSAvoidcrop damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The curtain transitions from a static stiffness structure to a dynamic one where stiffness varies with operational conditions. As the curtain bends to lean flexible crops, the bend angle remains small, keeping the stiffness low and preventing damage. When handling rigid crops requiring larger bend angles, the stiffness naturally increases to provide sufficient leaning capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different portions of the curtain have different local properties that contribute to the overall variable stiffness characteristic. The curtain may have varying thickness, material density, or construction across its surface, with regions designed to provide appropriate stiffness characteristics at different locations and bend angles.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3984343B1Cutter implement with curtain
Publication Date: 2025.04.23 DEERE & CO
  • EP3984343B1 patent drawingFigure 1
  • EP3984343B1 patent drawingFigure 2A
  • EP3984343B1 patent drawingFigure 2B

AI summary

The cutter implement may include a housing, a cutter, and a curtain. The housing has a forward end for engaging the crop material when moving in a direction of operation. The housing at least partially defines a cutting region disposed at the forward end. The cutter is coupled to the housing and can cut the crop material in the cutting region. The curtain is coupled to the forward end of the housing and is positioned forward of the cutter relative to the direction of operation for engaging and leaning the crop material upstream of the cutter. The curtain includes a stiffness control feature operable to control a vertical stiffness of the curtain to provide a variable vertical stiffness that increases with an increase in a bend angle of the curtain rearward relative to the direction of operation.