Shaving Unit Adjustment Mechanism for Stationary Pivot Axis

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Solution Overview

Problem

Existing electric shavers face challenges in combining the functionality of adjusting the exposure distance of the shaving surface relative to the skin supporting surface with the ability to follow skin contours through a pivoting arrangement, without introducing pivoting inaccuracy.

Innovation Solution

A shaving unit design that incorporates a base member with a hair-cutting unit featuring an external cutting member, an internal cutting member, a skin supporting member, and an adjustment mechanism. The adjustment mechanism allows for the adjustment of the exposure distance while maintaining a stationary pivot axis, ensuring accurate pivoting and contour following.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the external cutting member and skin supporting member are made pivotable to follow skin contours, then the ability to follow skin contours is improved, but pivoting accuracy deteriorates when the exposure distance is adjusted

Engineering Contradiction:

Improveability to follow skin contoursVSAvoidpivoting accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The shaving unit is divided into separable components: the external cutting member assembly and the skin supporting member assembly, each capable of independent pivoting movements. This segmentation allows each component to be optimized for its specific function while maintaining overall adaptability to skin contours.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The shaving unit employs dynamic pivot axes that can adjust their position based on the exposure distance setting. When the exposure distance changes, the pivot axis position automatically adjusts to maintain optimal pivoting accuracy, transforming a static system into a dynamic one that adapts to different operating conditions.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If the exposure distance is adjusted by changing the relative position of cutting members, then the shaving performance is improved, but the pivot axis position becomes unstable

Engineering Contradiction:

Improveshaving performanceVSAvoidpivot axis position stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

A bearing-supported member is introduced as an intermediary component between the external cutting member and the skin supporting member. This bearing-supported member maintains a stable pivot axis position while allowing the other components to adjust their relative positions for exposure distance changes, thus mediating between the need for adjustability and stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The bearing-supported member serves multiple functions: it supports the pivot axis, maintains stable positioning, and allows for exposure distance adjustments. This multi-functionality resolves the contradiction by providing a single component that addresses both stability and adjustability requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If the external cutting member and skin supporting member are pivotably arranged, then contour following is improved, but alignment accuracy deteriorates when exposure distance varies

Engineering Contradiction:

Improvecontour following capabilityVSAvoidalignment accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system employs dynamic alignment compensation where the pivot axis position is adjusted in real-time based on the exposure distance setting. This dynamic adjustment ensures that alignment accuracy is maintained across different exposure distances, transforming a static alignment problem into a dynamically solvable one.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of pivot axis position dynamically based on the exposure distance. By adjusting this parameter, the system maintains optimal alignment accuracy across different operating conditions, resolving the contradiction between adaptability and precision.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4347198B1Adjusting a relative position in an exposure direction of two pivotably arranged members of a shaving unit

Publication Date: 2025.02.19 KONINKLIJKE PHILIPS NV

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AI summary

:A hair-cutting unit comprises an external cutting member (10) having a shaving surface (11) provided with hair-entry openings and a skin supporting member (30) having a skin supporting surface (31) surrounding the external cutting member (10). The hair-cutting unit is further equipped with an adjustment mechanism (50) configured to adjust an exposure distance over which the shaving surface (11) protrudes relative to the skin supporting surface (31) in an exposure direction (E). The external cutting member (10) and the skin supporting member (30) are jointly pivotal about a stationary pivot axis. The adjustment mechanism (50) is designed such that the stationary character of the pivot axis can be maintained for every possible relative position of the external cutting member (10) and the skin supporting member (30), so that a well-functioning combination of the adjustment mechanism (50) and the pivoting arrangement of the respective members (10, 30) is realized.