Baffled Trimmer Guard for Noise Reduction and Line Control

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Solution Overview

Problem

Existing trimmers generate excessive noise during operation and require manual advancement of trimmer line, which can damage the power tool and is undesirable.

Innovation Solution

A trimmer guard with a body featuring a deck and a skirt, equipped with baffles to reduce noise and a line cutter assembly to manage trimmer line, including a blade that can be removably positioned for different cutting radii, is integrated with the trimmer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the motor power is reduced to lower noise generation, then noise level decreases, but performance and cutting capability deteriorate

Engineering Contradiction:
Improvenoise levelVSAvoidmotor performance
Core Design Contradiction:
Object-affected harmful factorsVSPower

Solution Approach 1:

The patent introduces a trimmer guard as an intermediary component between the motor and the external environment. The guard includes noise baffles that intercept and block sound waves generated by the motor, preventing them from propagating outward while allowing the motor to operate at full power without compromising performance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If manual advancement method is used to feed trimmer line, then device complexity is reduced, but reliability and risk of damage increase

Engineering Contradiction:
Improveline advancement mechanismVSAvoidtool durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a self-service line advancement system where the trimmer guard automatically feeds new trimmer line when the existing line becomes exhausted. The guard includes a line cutter assembly with a blade that can be positioned to automatically cut and feed new line, eliminating the need for manual intervention and preventing damage to the power tool

Inventive Principle:
Principle #25Self-service

3Ease of operation

If bump feed method is used to advance trimmer line, then ease of operation is improved, but harmful factors and damage to power tool increase

Engineering Contradiction:
Improveline advancement operationVSAvoiddamage to power tool
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The trimmer guard acts as a protective intermediary between the trimmer line and the power tool body. The guard includes a line cutter assembly positioned to intercept and manage the trimmer line, preventing direct contact between the line and the power tool components that would cause damage during the line advancement process

Inventive Principle:
Principle #24Intermediary (Mediator)

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 trimmer guard effectively reduces noise and automates trimmer line advancement, enhancing user safety and tool durability.

Implementation Method 1

A plurality of baffles are formed on the body of the trimmer guard. The baffles are adapted to reduce noise generated by the trimmer during operation.

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentEP4154696B1Trimmer guard and trimmer
Publication Date: 2026.01.07 TECHTRONIC CORDLESS GP
  • EP4154696B1 patent drawingFigure 1~2
  • EP4154696B1 patent drawingFigure 3
  • EP4154696B1 patent drawingFigure 4

AI summary

Trimmer guards and trimmers are provided. A trimmer guard includes a body having a deck having an inner side adapted for connecting the trimmer guard to a trimmer; an outer side that is substantially arc-shaped. The body of the trimmer has a first edge and a second edge each arranged between the inner side and the outer side. The body further has a skirt extending from the outer side at an angle to the deck. The body includes a line cutter assembly on a bottom surface. When the trimmer guard is connected to a trimmer, the deck and the skirt together define a space for housing a rotary cutting tool of a cutting assembly of the trimmer. A plurality of baffles are formed on the body of the trimmer guard. The baffles are adapted to reduce noise generated by the trimmer during operation.