Locking Top Cage for Freeze-Drying Vessel Stopper
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Solution Overview
Problem
Existing locking tops for vessels with necks, used in pharmaceutical applications for freeze-drying, either reduce evaporative flux or fail to securely hold the stopper during the process due to their design, which affects the effectiveness of freeze-drying.
Innovation Solution
A locking top with a cage structure that can adopt two positions: an intermediate holding position allowing evaporative flux and a locking position for secure sealing, featuring flexible tabs and a shear zone for easy transition between positions, ensuring secure stopper holding and efficient gas exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lower ring of the muselet completely surrounds the neck of the vessel, then the stopper is securely held, but the gas exchange capacity is drastically reduced
Solution Approach 1:
The cage is segmented into multiple bridges (first bridges, second bridges, third bridges) that are distributed around the circumference. This segmentation allows gas to pass through the spaces between bridges while still providing secure stopper holding, resolving the contradiction between complete surrounding for security and open structure for gas exchange.
Solution Approach 2:
Different bridges have different functions: first bridges hold the stopper, second bridges provide structural support, and third bridges allow gas passage. This local differentiation of qualities enables the structure to simultaneously achieve secure holding and maintain evaporative flux.
2Object-generated harmful factors
If the stopper is pushed only partially into the neck during freeze-drying, then evaporative flux is maintained, but the stopper is not held securely
Solution Approach 1:
The cage is designed to be dynamically positionable in two states: an intermediate position during freeze-drying that allows gas exchange, and a locked position that provides secure sealing. This dynamic adaptability resolves the contradiction between partial insertion for evaporative flux and secure holding.
3Device complexity
If the stopping device is merely placed on the stopper without being held, then the structure is simple, but the device and stopper can become disconnected accidentally
Solution Approach 1:
The cage is merged with the stopper through mechanical interlocking features including flexible tabs that engage with the stopper and breaking bridges that provide irreversible connection. This merging ensures the stopping device remains securely attached to the stopper throughout the process.
Data Source
AI summary
A locking top for blocking a stopper in the neck of a vessel comprises an outer body and a cage that is configured to fit into and lock axially in the outer body. The cage comprises an upper ring, a plurality n of branches connected to the upper ring, n/2 median bridges and n/2 lower bridges arranged in alternation on the periphery of the cage, each connecting together two adjacent branches. When the top is in an intermediate holding position in which the stopper is partially pushed into the neck, the lower bridges surround, at least in part, a collar of the neck; the median bridges located, in an axial direction, between the upper ring and the lower bridges are designed to form an open space between them and the collar.