Autonomous Mower Height Adjustment Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing autonomous mowers lack efficient and cost-effective mechanisms for adjusting the height of cut (HoC) without causing binding or chatter during operation, especially when dealing with varying grass heights and conditions.

Innovation Solution

An autonomous mower with a cutting assembly featuring a tool drive system and HoC control system that allows for automatic or manual adjustment of the cutting blade height, utilizing a threaded engagement between inner housing portions to translate the cutting blade assembly relative to the chassis, and incorporating a seal to prevent debris ingress, ensuring smooth operation and minimal binding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a height adjustment mechanism is implemented in autonomous mowers, then the adaptability to different grass conditions is improved, but the device complexity increases

Engineering Contradiction:
Improveheight of cut adjustmentVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cutting blade assembly is made dynamically adjustable through a threaded engagement mechanism that allows the inner housing portions to move relative to each other, enabling the mower to adapt to different grass heights and conditions while maintaining a relatively simple mechanical structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The height of cut parameter is changed by adjusting the position of the cutting blade assembly through threaded engagement, allowing the system to modify its operational parameter without requiring complex reconfiguration of the entire mower structure

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the cutting blade assembly is adjusted to different heights, then the adaptability to varying grass conditions is improved, but binding or chatter during operation occurs

Engineering Contradiction:
Improveheight of cut adjustmentVSAvoidoperational smoothness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The threaded engagement mechanism is extracted as a separate, dedicated component that specifically handles height adjustment, isolating the adjustment function from the main cutting assembly and allowing smooth transitions without interfering with the operational reliability of the cutting blade

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The threaded engagement between inner housing portions is designed to prevent binding and chatter by providing a cushioned, controlled transition mechanism that anticipates and mitigates mechanical stress during height adjustments, ensuring smooth operation across different cutting heights

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Manufacturing precision

If inner housing portions are engaged through threaded engagement, then the height adjustment precision is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveheight adjustment precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The housing is segmented into multiple inner housing portions that can be manufactured separately and then assembled through threaded engagement, allowing each component to be produced using standard manufacturing processes while achieving precise height adjustment through the assembled configuration

Inventive Principle:
Principle #1Segmentation

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

Enables consistent and seamless transition between different heights-of-cut, maintaining effective cutting performance across varying grass conditions while minimizing mechanical stress and wear, thus enhancing operational efficiency and reducing manufacturing complexity.

Implementation Method 1

utilizing a threaded engagement between inner housing portions to translate the cutting blade assembly relative to the chassis

Methodology Applied
Scientific EffectThreaded engagement: Screw

Data Source

PatentEP4054309B1Autonomous mower
Publication Date: 2025.04.02 THE TORO COMPANY
  • EP4054309B1 patent drawingFigure 1
  • EP4054309B1 patent drawingFigure 2
  • EP4054309B1 patent drawingFigure 3

AI summary

Aspects relate to an autonomous ground working vehicle. The vehicle has a chassis, wheels coupled to the chassis, a motor housing coupled to the chassis, a tool motor, and a tool. The motor housing defines a motor cavity extending in an axial direction and has a first inner housing portion having a first helical thread about the motor cavity and a second inner housing portion having a second helical thread about the motor cavity that engages the first helical thread. The first inner housing portion has a motor mounting surface and is axially translatable relative to the chassis and rotatably fixed relative to the chassis. The second inner housing portion is rotatable relative to the chassis and axially fixed relative to the chassis. The tool motor is fixed to the motor mounting surface and has an output shaft extending in a first direction. The tool is fixed to the output shaft.