Rear Hitch Extension Layout for Work Vehicles With Protruding CVT

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Solution Overview

Problem

The obstruction caused by the rearward protrusion of the hydraulic static continuously variable transmission in existing multi-purpose vehicles hinders easy attachment of a hitch, and existing solutions do not adequately address this issue.

Innovation Solution

A work vehicle design featuring a guard member covering the transmission, a first attachment portion overlapping with rear wheels, an extension member protruding rearward from this attachment, and a second attachment portion for hitch connection, which is positioned rearward of the transmission, allowing easy hitch attachment and minimizing obstruction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the hydraulic static continuously variable transmission protrudes rearward from the body, then the transmission can be positioned to overlap with rear wheels, but the transmission causes obstruction when the hitch is attached from the rear side

Engineering Contradiction:
Improveease of hitch attachmentVSAvoidobstruction by transmission
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

An extension member is introduced as an intermediary component between the body frame and the hitch. This extension member extends rearward from the body frame at a position overlapping with rear wheels, allowing the hitch to be attached at its front end to the extension member while its rear end connects to the towing object, thereby bypassing the obstruction caused by the transmission and enabling easy rear-side hitch attachment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the hitch attachment position is located further forward on the body from the transmission, then the transmission obstruction is avoided, but the attachment position becomes difficult to visually recognize

Engineering Contradiction:
Improveease of hitch attachmentVSAvoidvisual recognition of attachment position
Core Design Contradiction:
Ease of operationVSDifficulty of detecting and measuring

Solution Approach 1:

The extension member utilizes the longitudinal dimension (extending rearward from the body frame) to reposition the hitch attachment point. By extending in the front-rear direction, the extension member brings the hitch attachment position to a location that is both rearward of the transmission obstruction and visually accessible from the rear side of the vehicle, resolving both the obstruction and visibility issues simultaneously.

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

3Reliability

If the extension member is permanently fixed to the body frame, then the hitch attachment structure is stable, but the extension member may contact obstacles located behind the work vehicle

Engineering Contradiction:
Improvestability of hitch attachmentVSAvoidcontact with obstacles
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The extension member is designed with removable attachment to the body frame, transforming it from a static permanent fixture to a dynamic configurable component. This allows the extension member to be installed when hitch functionality is needed and removed when not in use, preventing contact with obstacles behind the vehicle while maintaining stability during hitched operations.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4644160A1Work vehicle
Publication Date: 2025.11.05 KUBOTA CORP
  • EP4644160A1 patent drawingFigure 1
  • EP4644160A1 patent drawingFigure 2
  • EP4644160A1 patent drawingFigure 3

AI summary

A work vehicle includes an engine (6), a running gear (2) having rear wheels (22), a continuously variable transmission (8) that protrudes rearward from the rear wheels (22) and that is configured to continuously change driving force from the engine, a guard member (9) covering the continuously variable transmission (8) at least from a rear side, a first attachment portion provided at a position overlapping with the rear wheels (22) in a side view, and an extension member (11) attached to the first attachment portion and protruding rearward from the first attachment portion, in which the extension member (11) is connected to the guard member (9) and has a second attachment portion to which a hitch (14) is attachable.