Quick-Change Blade Cover Assembly for Lawn Mowers

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Solution Overview

Problem

Lawn mower operators face difficulties in quickly and easily changing blades due to perceived complexity and the need for tools, which can lead to suboptimal lawn care performance and satisfaction.

Innovation Solution

A quick-change blade system with a cover assembly that houses a blade mount with a latch assembly, allowing for tool-free and one-handed blade removal and replacement, while protecting the blade holding assembly from debris.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional blade mounting system is used, then the blade is securely held, but the blade change process becomes complex and requires tools

Engineering Contradiction:
Improveease of blade changeVSAvoidcomplexity of blade mounting system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The blade mounting system is segmented into modular components: a blade holder with clutch mechanism, a separate cover assembly with latch, and a quick-change blade. This segmentation allows each component to perform its specific function independently, enabling tool-free blade changes while maintaining secure holding through the clutch-latch interaction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cover assembly acts as an intermediary between the operator and the blade holder. By providing a protective cover with an easy-to-operate latch mechanism, it mediates the interaction between the user and the complex clutch mechanism, simplifying the blade change process while protecting the internal components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the blade mount is exposed, then blade changes are easily accessible, but the blade mount is vulnerable to debris damage

Engineering Contradiction:
Improveprotection from debrisVSAvoidaccessibility of blade mount
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The cover assembly is designed to be opened before blade removal and closed after blade installation. This preliminary action of opening the cover provides accessible reach to the blade holder and clutch mechanism, while the subsequent closing action restores protection against debris. The latch mechanism enables this sequence to be performed quickly by hand.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cover assembly functions as a flexible protective shell that can be rapidly opened and closed. This thin-walled structure provides adequate protection against debris while allowing easy manual operation to access the blade mounting components when needed.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If a secure latch mechanism is used, then the blade is firmly secured, but the mechanism becomes harder to operate quickly

Engineering Contradiction:
Improvesecurity of blade holdingVSAvoidtime for blade change
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The clutch mechanism within the blade holder provides self-service security: once the blade is inserted and the cover latch is engaged, the clutch automatically maintains firm holding without requiring continuous operator input. This self-locking feature ensures reliable blade security while minimizing the time and effort needed for blade changes.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3027000B1Quick-change blade cover assembly
Publication Date: 2019.11.06 HUSQVARNA AB
  • EP3027000B1 patent drawingFigure 1A
  • EP3027000B1 patent drawingFigure 1B
  • EP3027000B1 patent drawingFigure 2

AI summary

A lawn care device may include a cutting deck housing at least one blade, a rotatable shaft, and a blade mount operably coupled to the rotatable shaft. The blade mount may include a clasp to secure the at least one blade within an engagement slot of the blade mount. The cover assembly may form a cavity with at least one sidewall extending substantially around a periphery of the blade mount.