Razor Assembly Recovering Force Dynamics

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional razor assemblies with rotational motion for shaving blades face challenges in achieving an appropriate rotation range and recovering force, leading to either stiff rotation or inadequate contact with the skin, resulting in inefficient shaving and potential skin irritation.

Innovation Solution

A razor assembly with a recovering force-providing unit that increases recovering force at a greater rate in the second pivot section than the first, allowing for a wider rotation range and smoother shaving, while maintaining sufficient support during the shaving process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If recovering force is increased to maintain good contact between razor cartridge and skin, then contactability is improved, but rotation becomes stiff

Engineering Contradiction:
ImprovecontactabilityVSAvoidrotation smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The recovering force-providing unit is designed to dynamically adjust the recovering force based on the rotational angle. The force increases as rotation progresses, providing stronger contact force when the cartridge is rotated away from the skin, while allowing smoother initial rotation. This dynamic adjustment resolves the contradiction between maintaining contact and enabling smooth rotation.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If rotation range is increased to accommodate curvy skin areas, then adaptability is improved, but excessive rotation makes shaving inconvenient

Engineering Contradiction:
Improveskin area coverageVSAvoidshaving convenience
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent defines a specific rotation angle parameter (α) that ranges from 0° to 45°, which is optimized to balance adaptability and convenience. This angular parameter change allows the cartridge to accommodate curvy skin areas while preventing excessive rotation that would make shaving inconvenient. The recovering force also changes with this angle parameter, increasing as the angle increases.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If recovering force is decreased to enable smooth rotation, then rotation smoothness is improved, but contactability deteriorates

Engineering Contradiction:
Improverotation smoothnessVSAvoidcontactability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The recovering force acts periodically during the rotation process, with different force magnitudes at different rotational stages. Initially, when rotation begins, the force is lower to allow smooth movement. As rotation progresses and the cartridge moves away from the skin, the force increases periodically to maintain contact. This periodic variation in force resolves the contradiction between smooth rotation and contactability.

Inventive Principle:
Principle #19Periodic action

4Ease of operation

If rotation range is decreased to prevent excessive rotation, then shaving convenience is improved, but adaptability to curvy skin deteriorates

Engineering Contradiction:
Improveshaving convenienceVSAvoidskin area coverage
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The recovering force-providing unit is pre-configured with a spring mechanism that is preliminarily compressed to store elastic energy. This preliminary action ensures that as the cartridge rotates and moves away from the skin, the stored energy is released to provide the necessary recovering force, enabling the cartridge to adapt to curvy skin areas while maintaining shaving convenience through the controlled 0° to 45° rotation range.

Inventive Principle:
Principle #10Preliminary action

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 enables efficient and comfortable shaving by providing the necessary recovering force and rotation range, reducing skin irritation and improving shaving performance, especially on curvy skin areas.

Implementation Method 1

a recovering force-providing unit configured to provide the razor cartridge having been rotated about the first rotational axis from a rest position with a recovering force for returning the razor cartridge to the rest position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3928935B1Razor assembly
Publication Date: 2024.03.13 DORCO CO LTD
  • EP3928935B1 patent drawingFigure 1A~1B
  • EP3928935B1 patent drawingFigure 2(a)~2(c)
  • EP3928935B1 patent drawingFigure 3

AI summary

In some embodiments, the present disclosure provides a razor assembly including a razor cartridge, razor handle, and recovering force-providing unit. The razor cartridge includes a shaving blade having a cutting edge and a blade housing receiving the shaving blade longitudinally. The razor handle is connected to the razor cartridge rotatably about a first rotational axis parallel to longitudinal direction within a rotation range. The recovering force-providing unit provides the razor cartridge rotated about the first rotational axis from a rest position with recovering force returning the razor cartridge to the rest position. The rotation range includes a first pivot section between the rest position and first angle, and a second pivot section between the first angle and a greater second angle. The recovering force increases as the razor cartridge rotates with an increasing rotational angle, at an increasing rate that differs between the first and second pivot sections.