Recessed Cutter Assembly in Trimmer Head Housing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing trimmer heads require users to cut and replace trimmer line manually, which is inconvenient and can lead to messes and unattended equipment, as they often lack a built-in cutter for trimming line length at the point of use.

Innovation Solution

A trimmer head design incorporating a recessed knife or cutter assembly within the housing, allowing for easy cutting of trimmer line to desired length directly in the trimmer head, with optional deflectable doors to prevent debris entry and enhance usability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a built-in cutter is integrated into the trimmer head, then convenience of cutting trimmer line at the point of use is improved, but device complexity increases

Engineering Contradiction:

Improveconvenience of cutting trimmer lineVSAvoidstructure of trimmer head

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the cutter function with the trimmer head housing by providing a recess in the housing that receives a cutter assembly. This integration merges two separate functions (trimming vegetation and cutting trimmer line) into a single unified device, eliminating the need for separate cutting tools and enabling convenient on-site line cutting while maintaining relatively simple device structure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The passageway in the trimmer head housing serves as an intermediary structure that provides access to the cutter assembly. This passageway allows the user to insert trimmer line for cutting without exposing sharp edges externally, and also serves as a receptacle for receiving cut line pieces. The deflectable door acts as another intermediary element that controls access to the cutter while protecting users from sharp edges.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a recessed cutter assembly with deflectable door is used, then safety by preventing debris entry and user protection is improved, but ease of operation decreases due to additional access steps

Engineering Contradiction:

Improvedebris entry and user safetyVSAvoidaccess to cutter

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The deflectable door is designed to be movable rather than fixed, allowing it to flex open when the user applies force to insert trimmer line for cutting, and flex closed when not in use. This dynamic design provides automatic protection without requiring separate locking mechanisms, and the door's flexibility allows easy access when needed while maintaining safety during operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The recessed cutter assembly design allows the cutter to perform its cutting function automatically once the trimmer line is inserted into the passageway. The user simply needs to fold the trimmer line and insert it into the passageway where the cutter automatically cuts it to length, eliminating the need for manual measurement or external cutting tools.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS9861034B2Trimmer head with incorporated line cutter

Publication Date: 2018.01.09 SHAKESPEARE CO

AI summary

A trimmer head for a rotary trimmer, includes an upper housing and a lower housing secured to the upper housing, wherein either the upper housing or the lower housing has a passageway. The trimmer head also includes a cutter assembly maintained in the passageway, wherein the cutter assembly has a knife, and wherein trimmer line inserted into the passageway is cut by the knife. A related method of cutting a trimmer line using the cutter assembly incorporated into a trimmer head is also disclosed.