Multi-Material Stop Element for Hair Removal Device Noise Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hair removal devices often produce unwanted tactile and audible feedback due to the abutment of stop elements, which can be uncomfortable and noisy, especially when the device is subjected to external impact.

Innovation Solution

The use of multi-component injection moulding to create stop elements from a combination of harder and softer plastic materials, where the softer material is used for damping and cushioning, reducing noise and enhancing user comfort by creating a soft stop mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If stop elements are made from hard plastic material to ensure structural strength and protect components during impact, then device protection is improved, but tactile and audible feedback (noise and hard end stop sensation) increases

Engineering Contradiction:
Improvestructural strengthVSAvoidtactile and audible feedback
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The stop element is manufactured using multi-component injection molding to create a composite structure with a hard plastic material core providing structural strength and a soft plastic material outer layer reducing tactile and audible feedback. This composite approach allows simultaneous achievement of component protection and user comfort.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The stop element features different material properties in different regions: the core maintains hard properties for structural integrity and impact resistance, while the outer layer (particularly the stop face) has soft properties to cushion contact and reduce noise. This local differentiation of material quality resolves the contradiction between strength and comfort.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If separate stop elements are used to provide cushioning effect, then user comfort is improved, but device complexity and assembly effort increase

Engineering Contradiction:
Improvenoise and tactile feedbackVSAvoidnumber of component parts
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The stop element combines multiple functions into a single integrated component: structural support, impact protection, and noise reduction are all achieved through one multi-material stop element rather than requiring separate components. This merging reduces assembly complexity while maintaining comfort benefits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-component stop element serves multiple purposes simultaneously: it limits head pivoting movement, protects components during impact, and provides noise reduction. This multi-functionality eliminates the need for separate cushioning elements, reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 approach effectively suppresses noise and enhances user comfort by providing a cushioning effect during head movement and external impacts, while also reducing the number of components and production costs.

Implementation Method 1

The combination of a harder or more rigid plastic material withstanding e.g. mechanical loads with a softer plastic material permits damping of the abutment limiting the pivoting of the head with respect to the handle.

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 2

the softer plastic material may cushion e.g. mechanical loads if the device is subject to external impact forces, e.g. when dropping the device

Methodology Applied
Scientific EffectCushioning: Damping

Data Source

PatentEP3546147B1Hair removal device
Publication Date: 2023.05.24 BRAUN GMBH
  • EP3546147B1 patent drawingFigure 1
  • EP3546147B1 patent drawingFigure 2~4

AI summary

The present invention is concerned with a hair removal device comprising a handle (2), which encases a drive unit (6) and an energy source, and a head (3), which is pivotably supported on the handle (2) and comprises at least one hair removal unit (4, 5) coupled to the drive unit (6) by means of a transmission converting a motion of the drive unit into a movement of a driven part of the at least one hair removal unit (4, 5). Pivoting of the head (3) with respect to the handle (2) is limited by abutment of a stop face (14, 16) of a stop element (7, 15) with a counter-stop element (8a, 8b, 12). The stop element (7, 15) is made by multi-component injection moulding from a first plastic material and a second plastic material which is softer than the first plastic material, wherein the stop face (14, 16) is made from the second plastic material.