Shaving Unit Drive Shaft Sealing via Shielding Members

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Solution Overview

Problem

Low-end rotary electric shavers often lack a sealing component in the drive shaft opening, leading to compromised functionality and reduced lifespan due to debris contamination, which increases costs and complexity in high-end designs.

Innovation Solution

Incorporating a first shielding member integrally formed with the base portion and a second shielding member with the holder, which engage to seal the drive shaft opening without separate sealing components, ensuring the hair-collecting chamber is isolated from the main body's interior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing component is added to seal the drive shaft opening, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidcomponent quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the sealing function with the holder component by integrating a sealing ring into the holder's opening. This merging of functions eliminates the need for a separate sealing component, thereby improving reliability while avoiding increased device complexity. The holder now serves both its original purpose of holding the cutting members and the additional function of sealing the drive shaft opening.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a sealing component is added to seal the drive shaft opening, then reliability is improved, but manufacturing cost increases

Engineering Contradiction:
Improvesealing performanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By integrating the sealing ring into the holder component, the patent eliminates the need for a separate sealing component, reducing the total number of parts that need to be manufactured and assembled. This merging approach lowers manufacturing costs while maintaining the necessary sealing performance for reliability.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the holder structure is modified to include sealing, then sealing performance is improved, but device complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidholder structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates a sealing ring directly into the holder's opening structure, combining the holding function and sealing function into a single component. This integration improves sealing performance while minimizing increases in device complexity, as the sealing feature is incorporated into the existing holder geometry rather than adding a separate complex sealing mechanism.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4274714B1Sealing an opening through which a drive shaft extends in a shaving unit for a rotary electric shaver
Publication Date: 2024.07.17 KONINKLIJKE PHILIPS NV
  • EP4274714B1 patent drawingFigure 1~2
  • EP4274714B1 patent drawingFigure 3~4
  • EP4274714B1 patent drawingFigure 5~6

AI summary

In a hair-cutting unit (6) of a shaving unit (3), a supporting member (30) surrounding and supporting an external cutting member (10) is present, and further a holder (40) mounted to the supporting member (30) is present. A base portion (7) of the shaving unit (3) comprises a hair-collecting chamber (50), a drive shaft (60) extending through an opening (71) in a bottom portion (70) of the base portion (7), and a first shielding member (72) surrounding this bottom opening (71). The holder (40) comprises a second shielding member (42) surrounding an opening (41) in the holder (40), wherein, in a coupled condition of the hair-cutting unit (6) and the base portion (7), the first shielding member (72) and the second shielding member (42) together surround the drive shaft (60) and thereby seal the bottom opening (71) relative to the hair-collecting chamber (50).