Spring-Based Removable Brush Head Coupling for Electric Toothbrushes

Solution Overview

Problem

Existing electric toothbrushes face issues with increased cost and weight due to magnet-based coupling, and potential corrosion from environmental moisture, necessitating a more efficient and cost-effective coupling mechanism for the brush head.

Innovation Solution

A toothbrush head design incorporating a motion transmission assembly with springs and an eccentrically coupled elongated motion arm to transfer linear motion from the driveshaft to rotational motion, eliminating the need for magnets and reducing vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If magnets are used to couple the brush head to the driveshaft, then the coupling strength and motion transfer are improved, but the cost and weight of the brush head increase

Engineering Contradiction:

Improvecoupling strengthVSAvoidbrush head weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent replaces the magnetic coupling system with a mechanical spring-based coupling system. The spring assembly provides the necessary coupling strength and motion transfer through mechanical elasticity rather than magnetic attraction, thereby eliminating the need for magnets and reducing the brush head weight while maintaining effective drive shaft to brush section motion transfer.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If magnets are used to couple the brush head to the driveshaft, then the coupling strength is improved, but the cost of manufacturing increases

Engineering Contradiction:

Improvecoupling strengthVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces the magnetic coupling system with a mechanical spring-based coupling system. The spring assembly provides the necessary coupling strength and motion transfer through mechanical elasticity rather than magnetic attraction, thereby eliminating the need for magnets and reducing the brush head weight while maintaining effective drive shaft to brush section motion transfer.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If uncovered magnets or magnetic materials are used, then the coupling effectiveness is improved, but corrosion resistance deteriorates due to environmental moisture

Engineering Contradiction:

Improvecoupling effectivenessVSAvoidcorrosion resistance

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the magnetic coupling system with a mechanical spring-based coupling system. The spring assembly provides the necessary coupling strength and motion transfer through mechanical elasticity rather than magnetic attraction, thereby eliminating the need for magnets and reducing the brush head weight while maintaining effective drive shaft to brush section motion transfer.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses a spring assembly that can be easily replaced if worn or damaged. The spring is a simple mechanical component that can be manufactured cost-effectively and replaced without requiring complex disassembly or specialized tools, making it an economical solution compared to magnetic materials that would require corrosion protection measures.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 provides a secure, lightweight, and corrosion-resistant coupling that reduces noise and vibration, allowing for efficient motion transfer while simplifying assembly and user experience.

Implementation Method 1

a spring configured to transfer motion from the driveshaft receiver to the elongated motion arm

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The elongated motion arm can be eccentrically coupled to the brush section and can be configured to cause rotation of brush section in response to movement of the elongated motion arm

Methodology Applied

Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentUS20250275622A1Removable brush head for electric toothbrush

Publication Date: 2025.09.04 ORALIC SUPPLIES INC

AI summary

This document discloses a toothbrush head for an electric toothbrush. The toothbrush head a brush section having a plurality of bristles attached thereon, a stem having an opening for receiving a driveshaft of an electric toothbrush, and a motion transmission assembly disposed within the stem. The motion transmission assembly includes a spring and an elongated motion arm having a distal end portion and proximal end portion, the distal end portion being coupled to the brush section. The spring is configured to bias the elongated motion arm in a proximal direction relative to the stem.