Removable Shield Prevents Leakage in Safety Razor Cartridge

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Solution Overview

Problem

Existing safety razors with dispensing systems for flowable shaving aids face issues such as viscosity changes and adhesion problems due to meteorological conditions, leading to undesirable leakage and manufacturing challenges with non-flat surfaces and adhesive reactions.

Innovation Solution

A replacement cartridge design featuring a removable shield between the reservoir and dispensing head, which prevents flow until removed, using a grippable portion and weakened areas for easy separation, and optional springs to maintain fluid communication and prevent leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a removable tape is used to seal the dispensing head, then the shaving aid material can be prevented from leaking during storage and shipment, but the non-flat surface of the dispensing head creates manufacturing challenges and adhesive reaction problems

Engineering Contradiction:
Improveleakage preventionVSAvoidtape application difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The shield is divided into a flat portion that contacts the dispensing head and a grippable portion that extends outward. This segmentation allows the flat portion to provide a suitable sealing surface for the removable tape while the grippable portion enables easy user removal without requiring manipulation of the entire shield structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flat portion of the shield acts as an intermediary between the non-flat dispensing head surface and the removable tape. By providing a flat intermediate surface, it enables reliable adhesive bonding without requiring the dispensing head itself to be flat, thus resolving the manufacturing challenge.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the shield is made completely removable, then the user can easily remove it to start using the shaving aid material, but the shaving aid material may leak from the opening when the cartridge is not in use

Engineering Contradiction:
Improveshield removal easeVSAvoidleakage prevention during storage
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The shield transitions from a sealed state (when attached to the cartridge) to a removed state (when the user pulls the grippable portion). This dynamic design allows the shield to provide leakage prevention during storage and transport, then be easily removed by the user to access the shaving aid material.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The grippable portion is extracted from the main body of the shield and extended outward, creating a dedicated handling feature. This allows the user to grasp and remove only the shield without needing to manipulate the entire cartridge or deal with the opening mechanism, simplifying the removal operation.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the shield covers the entire opening, then leakage prevention is maximized, but the user cannot easily grasp and remove the shield

Engineering Contradiction:
Improveleakage preventionVSAvoidshield removal ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The shield is segmented into two functional portions: a flat portion that covers the opening for leakage prevention and a grippable portion that extends outward for user manipulation. This segmentation allows each portion to optimize its specific function while working together as a unified shield structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2358507B1Replacement cartridge for a safety razor
Publication Date: 2015.07.08 EVEREADY BATTERY CO INC
  • EP2358507B1 patent drawingFigure 1
  • EP2358507B1 patent drawingFigure 2A~2B
  • EP2358507B1 patent drawingFigure 3~4

AI summary

A replacement cartridge for a safety razor includes a dispensing head and a reservoir for a flowable shaving aid material. A removable shield is between the reservoir and the dispensing head and the shield interrupts fluid communication between channels of the reservoir and the dispensing head when the shield is in place. Fluid communication is permitted when the shield is removed. Removal of the shield is a onetime event. The shield can be a thermoplastic film. A razor cartridge can be disposed adjacent the dispensing head and the housing of the razor cartridge can be integrally formed with the housing of the dispensing head.