Refillable Cosmetic Pen Coupling for Torque-Limited Refill Advance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cosmetic applicators with refill mechanisms face issues of wastefulness due to the entire pen being discarded after use, and existing refill replacement systems are cumbersome or prone to damage from user misuse.
Innovation Solution
A cosmetic applicator with a sliding refill mechanism featuring two couplings: a first coupling for rotational movement transmission and a second coupling to prevent excessive torque, ensuring easy refill replacement and protection against accidental damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire pen including feed mechanism is discarded after refill exhaustion, then hygiene requirements are met, but sustainability and resource waste are compromised
Solution Approach 1:
The cosmetic applicator is divided into two separable parts: a reusable applicator body containing the feed mechanism and a disposable cartridge containing the refill. This segmentation allows the hygienic disposable portion to be discarded while the valuable feed mechanism is retained and reused, resolving the contradiction between hygiene compliance and resource waste.
2Loss of substance
If a cartridge system with separable housing is used for refill replacement, then sustainability is improved, but the replacement process becomes cumbersome requiring dexterous finger operation
Solution Approach 1:
The cartridge is designed to be completely extracted from the applicator body as a single unit, eliminating the need for users to manipulate small components or perform complex assembly operations. The cartridge can be removed and replaced by simple pulling and pushing motions, making the sustainable refill system easy to operate.
3Ease of operation
If a push rod mechanism is used for refill extension, then refill advancement is achieved, but the mechanism is vulnerable to damage from user errors such as over-extension or accidental rotation
Solution Approach 1:
A spring element is integrated into the coupling mechanism to provide mechanical cushioning against excessive forces. When users apply too much force or rotate the applicator body excessively, the spring compresses to absorb the excess energy, preventing damage to the refill advancement mechanism while allowing normal operation.
4Ease of operation
If the coupling allows free rotation for refill advancement, then ease of refill replacement is improved, but accidental over-rotation can damage the mechanism
Solution Approach 1:
The coupling mechanism incorporates a preliminary protective action by allowing controlled rotation for normal refill advancement while simultaneously providing mechanical limits through the spring-coupled design. This prevents excessive rotation from causing damage, as the spring mechanism absorbs accidental over-rotation forces before they can reach vulnerable components.
Data Source
AI summary
A refillable cosmetic applicator with a cartridge that accommodates a refill stick which is movable in relation thereto, and an applicator main body to which the cartridge can be attached, characterized in that the cosmetic applicator comprises two couplings, namely a first coupling by means of which a rotational movement generated by the user on the applicator main part is transmitted to the cartridge in such a way that the refill stick is displaced relative to it, and a (different) second coupling, by means of which it is prevented that a rotational movement is transmitted to the cartridge any longer as soon as the cartridge can no longer follow this rotational movement.