Brush Head Assembly Elastomeric Matrix Bristle Retention

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Solution Overview

Problem

Existing brush head assemblies face issues with bristle tufts becoming loose due to inadequate retention, leading to premature failure and inefficient manufacturing processes.

Innovation Solution

Embedding bristle tufts within an elastomeric matrix, with the proximal end of each tuft spaced from the retention ring, and using a network of webbing interconnected by an elastomeric matrix for enhanced retention and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bristle tufts are secured within retention rings using traditional methods, then the bristle tufts can be retained in the brush head, but the retention rings are not firmly secured and the bristle tufts can become loose under dynamic conditions

Engineering Contradiction:

Improveretention of bristle tuftsVSAvoidfirmness of retention ring securing

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent uses a composite structure combining rigid retention rings with a flexible elastomeric matrix material. The elastomeric matrix embeds and secures the retention rings, creating a composite assembly that provides both firm securing and flexibility under dynamic conditions, preventing the retention rings from becoming loose while maintaining reliable bristle tuft retention.

Inventive Principle:

Principle #40Composite materials

2Reliability

If bristle tufts are fused together using heat to form a fixed head, then the bristles are secured in position, but the process is time-consuming and expensive

Engineering Contradiction:

Improvefixing of bristle tufts in placeVSAvoidmanufacturing cycle time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the time-consuming heat fusion step from the manufacturing process by using pre-formed retention rings that mechanically hold the bristle tufts. The elastomeric matrix is then molded around the retention rings and bristle tufts, allowing the bristle tufts to be secured without requiring lengthy heat fusion operations, thus significantly reducing manufacturing cycle time and cost.

Inventive Principle:

Principle #2Taking out (Extraction)

3Ease of operation

If retention rings are used to secure bristle tufts, then the bristle tufts can be organized and retained, but under dynamic motion the bristle tuft structure undergoes higher stresses that could lead to separation

Engineering Contradiction:

Improveorganization of bristle tuftsVSAvoidstress on bristle tuft structure

Core Design Contradiction:

Ease of operationVSStress or pressure

Solution Approach 1:

The patent employs an elastomeric matrix that acts as a flexible shell embedding the retention rings and bristle tufts. This flexible matrix absorbs and distributes the higher stresses generated under dynamic motion conditions, preventing stress concentration on the bristle tuft structure and eliminating separation while maintaining ease of bristle tuft organization.

Inventive Principle:

Principle #30Flexible shells and thin films

4Volume of moving object

If the bristle tuft head is positioned close to the retention ring for compact structure, then the brush head is more compact, but the probability of the retaining head breaking through the retention ring increases

Engineering Contradiction:

Improvecompactness of brush headVSAvoidretention of bristle tuft head

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The elastomeric matrix serves as a cushioning layer between the bristle tuft head and the retention ring. This beforehand cushioning prevents the bristle tuft head from directly contacting and potentially breaking through the retention ring, maintaining reliable retention while allowing for a compact brush head design as the matrix can be molded to minimal thickness.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

This solution provides improved retention and flexibility of bristle tufts, reducing the likelihood of premature failure and streamlining the manufacturing process, resulting in cost-effective and efficient brush head production.

Implementation Method 1

there is elastomeric matrix located between the retention ring and the tuft ring. This provides for greater flexibility of tuft movement, and also, by reducing the pressure, reduces the probability of the retaining head breaking through the retention ring

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

the bristles are then fused together using heat to form a head which cannot be pulled out through the retention ring

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentEP3294088B1Brush head assembly and methods of manufacture

Publication Date: 2022.07.06 KONINKLIJKE PHILIPS NV

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AI summary

A brush head (32) including a neck (40) having a brush neck (42); a plurality of bristle tufts (21), each of which includes a plurality of bristle strands with a free end (25) and a proximal end (23), the proximal end having a proximal end head portion (26); a plurality of retention rings (50), each configured to receive the proximal end of at least one of the plurality of bristle tufts; an elastomeric matrix (30) bonded to at least a portion of the brush neck, the plurality of retention rings, and the proximal end of the plurality of bristle tufts, wherein the proximal end head portion of each of the plurality of bristle tufts is configured to comprise a space (27) between the proximal end head portion and the respective retention ring.