Shape-Shifting Toothbrush Tuft with Variable Cross-Sectional Geometry

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Solution Overview

Problem

Existing toothbrush designs lack versatility in their tuft shapes, which limits their ability to meet advanced cleaning needs, and there is a need for a method to manufacture such advanced tufts.

Innovation Solution

A toothbrush head or brush carrier featuring a shape-shifting tuft with distinct first and second cross-sectional areas and shapes, where the planes of these cross-sections are parallel, and a method of manufacturing this tuft using a mold insert with corresponding cavities, fiber introduction, and connection techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional tuft with uniform cross-section is used, then the manufacturing process is simple, but the cleaning versatility and adaptation to different tooth surfaces is limited

Engineering Contradiction:
Improvecleaning versatilityVSAvoidtuft shape complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The tuft is divided into multiple sections along its length, with each section having a different cross-sectional shape. The first cross-section has a first shape and the second cross-section has a second shape that does not match the first when overlaid, allowing different parts of the tuft to perform different cleaning functions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the tuft are given different local geometries to optimize performance for specific cleaning tasks. The varying cross-sectional shapes create different fiber arrangements at different heights, enabling the tuft to adapt to various tooth surface geometries and provide enhanced cleaning versatility

Inventive Principle:
Principle #3Local quality

2Shape

If the cross-sectional area changes along the tuft length, then the tuft shape can be varied, but the structural consistency and mounting stability may be compromised

Engineering Contradiction:
Improvecross-sectional shape variationVSAvoidstructural consistency
Core Design Contradiction:
ShapeVSStability of the object's composition

Solution Approach 1:

The tuft employs asymmetric cross-sectional shapes where the first cross-sectional shape and second cross-sectional shape do not match when overlaid. This asymmetric design allows shape variation while maintaining structural integrity through careful design of the fiber arrangement and binding structure

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention changes the geometric parameters of the cross-section along the tuft length while maintaining the cross-sectional area substantially constant. By varying the shape parameters (such as orientation, eccentricity, or boundary definition) rather than the area parameter, the tuft achieves shape diversity while preserving structural consistency and mounting stability

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If advanced tuft shapes are implemented, then cleaning performance is enhanced, but the manufacturing complexity increases

Engineering Contradiction:
Improvecleaning capabilityVSAvoidmanufacturing simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The mold insert is pre-configured with cavities that define the complex shape-shifting tuft geometry before the molding process. By preparing the mold insert in advance with the precise cavity shapes, the complex tuft geometry can be manufactured efficiently through a single molding operation, reducing overall manufacturing complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mold insert cavities serve as negative copies of the desired tuft shapes. By creating precise inverse molds of the complex cross-sectional shapes, the manufacturing process can replicate the advanced tuft geometry accurately without requiring complex forming operations or multiple assembly steps

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4029406B1Toothbrush head or brush carrier
Publication Date: 2025.06.18 BRAUN GMBH
  • EP4029406B1 patent drawingFigure 1A~1B
  • EP4029406B1 patent drawingFigure 2A~2B
  • EP4029406B1 patent drawingFigure 3A~3B

AI summary

The present disclosure is concerned with a toothbrush head or a brush carrier having at least one carrier element, at least one shape-shifting tuft mounted on the carrier element such that the shape-shifting tuft raises from a mounting end on a mounting surface of the carrier element generally along an extension direction towards a free end of the shape-shifting tuft, the shape-shifting tuft having a length from the mounting base to the free end, the shape-shifting tuft comprising a plurality of fibers, and the shape-shifting tuft having a first cross-section having a first cross sectional area and shape at a first length along the extension direction, and a second cross-section having a second cross-sectional area and shape at a second length along the extension direction, wherein the first cross-sectional area and the second cross-sectional area are substantially identical and the first cross-sectional shape and the second cross-sectional shape are different so that the first cross-sectional shape does not match the second cross-sectional shape independent from an angle by which the first cross-sectional shape is rotated and independent from a displacement of the first cross-sectional shape.