Safety Razor Spring Finger Blocking Mechanism

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Solution Overview

Problem

Disposable safety razors often lack secure mechanisms for attaching and detaching razor cartridges, leading to potential detachment during abuse, such as drops, resulting in unsafe operation due to partial attachment.

Innovation Solution

A safety razor design featuring a handle with a movable arm and spring finger mechanism that prevents accidental disengagement of the razor cartridge by engaging pivoting connecting structures along a pivot axis, ensuring secure mounting and preventing release even under impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If disposable razors are designed without secure engagement mechanisms to simplify manufacturing and reduce cost, then ease of manufacture is improved, but reliability deteriorates as the razor cartridge may detach during abuse

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcartridge attachment security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The arm is designed to be movable relative to the handle, transitioning between a first position during engagement and a second position during disengagement. This dynamic mechanism allows the cartridge to be securely attached during normal use while enabling intentional release when needed, resolving the contradiction between secure attachment and ease of manufacture.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring finger changes its mechanical state based on applied force - remaining engaged under normal conditions but allowing disengagement when sufficient force is applied to overcome the spring's resistance. This parameter change enables the system to provide both secure attachment and controlled release without complex mechanisms.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If disposable razors include secure engagement mechanisms to prevent accidental detachment, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecartridge attachment securityVSAvoidengagement mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring finger automatically returns to its engaged position after the arm is moved, and the blocking structure automatically prevents accidental disengagement. The mechanism serves itself by using the user's intentional action (pressing the button or applying force) to trigger the engagement/disengagement sequence, eliminating the need for additional control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The engagement mechanism is divided into distinct functional elements: the movable arm for engagement, the spring finger for maintaining engagement, and the blocking structure for preventing accidental release. This segmentation allows each element to perform its specific function simply, reducing overall complexity while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the arm is made movable to enable engagement and disengagement, then ease of operation is improved, but stability deteriorates as the arm may move in the release direction causing accidental detachment

Engineering Contradiction:
Improvecartridge attachment and releaseVSAvoidarm position stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The spring finger is pre-positioned to engage with the arm, and the blocking structure is pre-configured to prevent movement in the release direction. These preliminary actions ensure that the arm remains stable during normal use while allowing controlled movement during intentional engagement or disengagement operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The blocking structure provides preliminary anti-action by preventing the arm from moving in the release direction before such movement can cause accidental detachment. This counter-action maintains stability while allowing the arm to be movable for intentional operations.

Inventive Principle:
Principle #9Preliminary anti-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 ensures the razor cartridge remains securely attached to the handle, preventing accidental detachment and ensuring safe operation by inhibiting movement in the release direction, thus enhancing user safety and usability.

Implementation Method 1

a spring finger having an end portion and that is flexible in a direction opposed to the mount direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

blocking structure having a blocking surface generally perpendicular to the pivot axis. The end portion of the spring finger is closely spaced from the blocking surface to prevent movement of the arm relative to the housing along the release direction

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2892697B1Safety razor
Publication Date: 2016.10.19 EDGEWELL PERSONAL CARE BRANDS LLC
  • EP2892697B1 patent drawingFigure 1
  • EP2892697B1 patent drawingFigure 2
  • EP2892697B1 patent drawingFigure 3

AI summary

A safety razor has a handle including an arm moveable relative to the handle and terminating in handle connecting structure engageable with cartridge connecting structure of a razor cartridge. The safety razor has a flexible spring finger having an end portion. The spring finger is integrally formed with one of a housing of the razor cartridge and the arm, and the other of the housing and the arm includes blocking structure having a blocking surface. The end portion of the spring finger is closely spaced from the blocking surface to prevent movement of the arm relative to the housing sufficient to disengage the handle pivoting connecting structure from the cartridge pivoting connecting structure thereby preventing accidental release of the razor cartridge from the handle.