Grass Mower Discharge Cover Locking Mechanism

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Solution Overview

Problem

Conventional grass mower devices face issues with maintaining the discharge-opening cover in a reliable closed posture without heavy operational resistance and preventing clogging of mulching baffle plates due to inadequate urging forces and design flaws.

Innovation Solution

The grass mower device incorporates a lock mechanism with a stopper member and a lock urging mechanism to maintain the discharge-opening cover in a closed posture with reduced operational effort and a mulching baffle plate design that directs grass clippings away from the cutting path, preventing clogging by allowing easy discharge to the rear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the urging force of the spring is increased to reliably hold the discharge-opening cover in the closed posture, then the reliability of cover closure is improved, but the operational resistance for switching the cover to the open posture increases making operation heavy

Engineering Contradiction:

Improvereliability of cover closureVSAvoidoperational resistance for switching cover

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The closing mechanism is segmented into two functional components: a spring-based urging mechanism that provides closing force, and a lock mechanism with a stopper member that provides holding force. This segmentation allows the spring to be designed with moderate urging force for reliable closing operation, while the lock mechanism independently provides the holding function to maintain the closed posture without requiring excessive spring force.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lock mechanism with the stopper member acts as an intermediary between the spring urging mechanism and the discharge-opening cover. The stopper member engages with the cover to provide the holding function, allowing the spring to exert only moderate urging force while the lock mechanism mediates to ensure reliable closure maintenance without heavy operational resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If a conventional spring-only urging mechanism is used for the discharge-opening cover, then the structure is simple, but the cover cannot be reliably held in the closed posture without heavy operational resistance or continuous spring force

Engineering Contradiction:

Improvestructural simplicityVSAvoidreliability of cover closure maintenance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lock mechanism is designed to automatically engage when the discharge-opening cover is closed by the spring urging force. The stopper member automatically locks into position to hold the cover closed, and automatically releases when the cover is opened, providing self-service locking and unlocking functions without requiring additional actuators or complex control systems.

Inventive Principle:

Principle #25Self-service

3Productivity

If the mulching baffle plate is positioned to surround the cutter blade rotational range, then grass cutting effectiveness is improved, but grass clippings accumulate and clog the baffle plate

Engineering Contradiction:

Improvegrass cutting effectivenessVSAvoidclogging of mulching baffle plate

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The harmful accumulation of grass clippings within the mulching baffle plate is addressed by providing a discharge opening that extracts and removes clippings from the baffle plate interior. The discharge opening cover with its locking mechanism allows selective opening to remove accumulated clippings, preventing clogging while maintaining the baffle plate's grass cutting effectiveness during normal operation.

Inventive Principle:

Principle #2Taking out (Extraction)

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

The solution allows for reliable operation of the discharge-opening cover with a light operational feel and prevents clogging of the mulching baffle plate, ensuring efficient grass cutting by maintaining the discharge-opening cover in a closed posture and directing clippings away from the cutting path.

Implementation Method 1

a lock urging mechanism for urging the lock mechanism to the locking state, the lock urging mechanism being configured to apply an urging force to the lock mechanism in response to switchover of the discharge-opening cover to the closing posture

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3329759B1Grass mower device and riding type grass mower having the grass mower device

Publication Date: 2020.10.07 KUBOTA CORP

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AI summary

A grass mower device includes a cover urging mechanism (26) for urging a discharge opening (20) to a closing posture, a lock mechanism (30) switchable between a locking state for holding the discharge opening (20) cover under the closing posture and a lock releasing posture for allowing switchover of the discharge-opening cover (20) to the opening posture, a lock urging mechanism (34) for urging the lock mechanism (30) to the locking state, and an operational portion (33) for switching the lock mechanism (34) to the lock releasing posture against the urging force of the lock urging mechanism (34).