Loop-Shaped Razor Spring Mechanism for Compact Pivot and Eject Travel

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Solution Overview

Problem

Current razor springs and spring mechanisms are inadequate due to their size, complexity, and functionality limitations, leading to fatigue, permanent deformation, and increased cost, particularly when additional benefits or accidental drops compromise their performance.

Innovation Solution

A loop-shaped spring member with overlapping end portions is used, providing angular rotation and enhanced stiffness for both pivot and eject functions, allowing for longer travel distances without exceeding yield stresses, and is designed to be compact and durable, made from stainless steel or flat wire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If coil springs or straight springs are used for pivot or eject functions, then the spring can provide the necessary force, but the spring occupies a lot of volume and has limited travel distance without exceeding yield stresses

Engineering Contradiction:
Improvespring forceVSAvoidspring volume
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The patent applies a loop-shaped spring configuration instead of traditional coil or straight springs. This curved loop geometry allows the spring to achieve greater deflection and travel distance within a compact volume, resolving the contradiction between providing sufficient force and minimizing volume occupation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The loop-shaped spring utilizes a two-dimensional planar configuration that can deflect in multiple directions, allowing for longer travel distances without increasing the overall volume occupied by the spring component.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Force

If coil springs or straight springs are used, then the spring can provide pivot or eject functionality, but the short length does not allow for large deflections or long travel distances without exceeding yield stresses

Engineering Contradiction:
Improvespring forceVSAvoidspring length
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The loop-shaped configuration extends the effective length of the spring in a curved path, allowing for larger deflections and longer travel distances while maintaining a compact overall footprint, thus resolving the contradiction between force provision and length constraints.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Adaptability or versatility

If separate springs are used for pivot and eject functions, then each function can be optimized, but the device complexity and cost increase

Engineering Contradiction:
Improvefunctional optimizationVSAvoidspring mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The loop-shaped spring is designed to perform multiple functions including pivot movement, eject functionality, and accidental drop protection within a single component, thereby reducing device complexity and component count while maintaining functional optimization.

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

Solution Approach 2:

The patent merges multiple spring functions into a single loop-shaped spring component, combining pivot and eject functionalities that would traditionally require separate springs, thus simplifying the overall device structure.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If traditional springs are used, then the basic pivot or eject function is provided, but fatigue and permanent deformation occur particularly after accidental drops

Engineering Contradiction:
Improvebasic functionalityVSAvoidspring durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The loop-shaped spring configuration inherently provides better shock absorption and stress distribution, protecting against fatigue and permanent deformation from accidental drops before they occur, thus improving reliability while maintaining basic functionality.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 loop-shaped spring member reduces fatigue and stress, enabling reliable long-term performance with low force requirements, providing improved design flexibility and maintaining functionality even after accidental drops, while reducing the overall volume occupied.

Implementation Method 1

a loop shaped spring member disposed in an assembly, the assembly having one or more movable portions wherein the one or more movable portions provide an angular rotation of the handle to the cartridge

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The loop-shaped spring member reduces fatigue and stress, enabling reliable long-term performance with low force requirements

Methodology Applied
Scientific EffectElastic recovery: Elastic Recovery

Data Source

PatentEP3546157B1Razor mechanisms
Publication Date: 2021.04.21 THE GILLETTE CO
  • EP3546157B1 patent drawingFigure 1A~1B
  • EP3546157B1 patent drawingFigure 1C~1D
  • EP3546157B1 patent drawingFigure 2A~2D

AI summary

The present invention describes a novel spring mechanism for a razor 70. In the razor, the spring member 10 may be disposed in a movable member assembly 72, portions of which may be used for ejection or pivoting. The spring may be fully encompassed within the assembly and be placed within supporting structures 94 therein. The spring is a loop-shaped element having overlapping end portions 12a, 12b with free distal ends 12a', 12b'. Alternately, the spring member 30A is tear drop shaped loop shape with distal ends 32a', 32b' that are spaced apart. The spring may be disposed within a first and/or second movable member 82, 84 such as an eject button or a pivot member. A retarding structure 14 on the spring provides a retarding force which is based on the interaction of the retarding structure 95 with a protrusion on an assembly portion to keep the spring orientation intact. The spring is desirably comprised of stainless steel and is a flat wire.