Blade Unit Segmentation for Narrow Area Shaving

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Solution Overview

Problem

Conventional electric razors with sliding members improve shaving comfort and reduce skin damage on wide areas but struggle with ease of shaving on narrow areas, such as under the nose, due to the positional relationship between reciprocating blades and the sliding member.

Innovation Solution

The blade unit features a comb-shaped outer blade with open and bent blade portions arranged alternately, allowing for effective scooping and cutting of body hair in narrow areas while reducing skin damage, and an engaging mechanism that regulates the movement of the comb-shaped outer blade relative to mesh-shaped outer blades to maintain optimal shaving performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a sliding member such as a roller is added to reduce friction and skin damage, then skin damage is reduced and shaving comfort is improved, but the ease of shaving narrow parts deteriorates due to the positional relationship between reciprocating blades and sliding member

Engineering Contradiction:
Improveskin damageVSAvoidease of shaving narrow parts
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The outer blade is divided into multiple blade units, each with its own sliding member. This segmentation allows each blade unit to independently contact the skin with its sliding member, enabling the razor to effectively shave both wide areas (where multiple blades work together) and narrow areas (where individual blade units can access tight spaces without interference from other blades or sliding members).

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sliding member acts as an intermediary between the reciprocating blade and the skin. By positioning the sliding member at the skin-contacting end of each blade unit, it mediates the interaction by reducing friction and preventing direct blade-skin contact that causes damage, while still allowing the blade to effectively cut hair even in narrow areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If multiple reciprocating blades are used to cut more body hair at once, then productivity is improved, but device complexity increases due to the need for sliding members and their positioning mechanisms

Engineering Contradiction:
Improvehair cutting efficiencyVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Multiple blade units are merged into a single integrated outer blade structure, with each blade unit having its own sliding member. This merging approach maintains high productivity by enabling simultaneous hair cutting across multiple blades, while the integrated design reduces overall structural complexity compared to having completely separate blade assemblies.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Each blade unit with its integrated sliding member serves multiple functions: cutting hair, reducing friction, and protecting skin. This multi-functionality eliminates the need for separate components for each function, thereby reducing device complexity while maintaining high productivity through the use of multiple blades.

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

Data Source

PatentEP4067021B1Blade unit and electric razor
Publication Date: 2025.01.22 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4067021B1 patent drawingFigure 1
  • EP4067021B1 patent drawingFigure 2~3
  • EP4067021B1 patent drawingFigure 4

AI summary

The present disclosure provides a blade unit that achieves both smooth skin sliding in a wide area and ease of shaving in a narrow area. Blade unit 200 according to the present disclosure comprises four or more outer blades extending in a first direction and sliding member 220 extending in the first direction, and blade unit 200 is attached to electric razor 300, wherein at least two outer blades included in the four or more outer blades are arranged on both sides of sliding member 220.