Asymmetric Hitch Frame for Offset Agricultural Tool Clearance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Agricultural machines, such as mower and mower conditioner types, face issues with ground clearance when crossing windrows due to weight distribution, leading to tire sag and insufficient height for passage, requiring cumbersome adjustments of hitching system components which are not always feasible, especially in newer, wider, and heavier machines.

Innovation Solution

The machine's structural design increases the distance between the lower coupling pins' axis and the tool's connection point, ensuring sufficient ground clearance through an asymmetrical construction and controlled pivoting, allowing simultaneous coupling and stable detachment without needing manual adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the machine uses a symmetrical hitch frame with equal-length arms, then the structure is simple and easy to manufacture, but the ground clearance becomes insufficient when the machine is laterally offset due to tire sagging

Engineering Contradiction:
Improvehitch frame symmetryVSAvoidground clearance
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The patent applies asymmetry by making the right hitch frame arm longer than the left arm. This asymmetric design compensates for the tire sagging that occurs on the right side when the machine is laterally offset, thereby maintaining sufficient ground clearance for the tool group to pass through windrows without touching the ground or swaths.

Inventive Principle:
Principle #4Asymmetry

2Shape

If the right axle stand is adjusted to a shorter length to compensate for sagging, then ground clearance is maintained, but the operation becomes cumbersome and adjustments may not be feasible with poorly maintained equipment

Engineering Contradiction:
Improveground clearanceVSAvoidadjustment complexity
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The patent implements preliminary action by pre-configuring the hitch frame with asymmetric arm lengths during manufacturing. This eliminates the need for field adjustments of axle stands, as the ground clearance compensation is built into the structure itself, making the system ready-to-use without requiring operator intervention or adjustment of movable components.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the machine is made wider and heavier to improve working performance, then productivity increases, but the sagging phenomenon becomes more significant

Engineering Contradiction:
Improveworking performanceVSAvoidsagging
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The asymmetric hitch frame design with the right arm extended further back specifically addresses the increased sagging caused by wider and heavier machine configurations. The additional length on the right side provides greater structural support and leverage to counteract the increased weight and width, maintaining ground clearance despite the enhanced working capabilities.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3108730B1Mounted agricultural machine with a group of tools that can be offset laterally
Publication Date: 2022.02.23 KUHN SA
  • EP3108730B1 patent drawingFigure 1
  • EP3108730B1 patent drawingFigure 2
  • EP3108730B1 patent drawingFigure 3A

AI summary

The present invention relates to a mounted agricultural machine comprising, on the one hand, a supporting structure (2) with a chassis (2'), a boom (7), and a hitch frame (2"), and, on the other hand, a set of tools (6) mounted on the boom (7), said boom (7) being able to bring the set of tools (6) into a laterally offset position and its inclination allowing the set of tools (6) to be moved between lowered and raised positions, the hitch frame (2") having two lower trunnions (5, 5') mutually aligned and with a common axis (AC) located in a horizontal plane, in the position when the machine (1) is removed, the agricultural machine (1) being characterized in that it incorporates in its structure, between its lower hitch trunnions (5, 5') and the free end (7") of the boom (7) carrying the tool or set of tools (6), a design arrangement intended, when the set tool (6) is in an offset position, to increase the distance between, on the one hand,the common axis (AC) of the two lower coupling trunnions (5, 5') or the plane containing simultaneously this axis (AC) and the direction of advance and, on the other hand, the connection point (8) between the end (7") of the boom (7) and the tool group (6).