Vial Adapter Hinged Zones for Secure Snap Fit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid drug transfer devices face misalignment issues with injection vials due to non-uniform telescopic snap fits across different vial tube outer diameters, leading to detachment reaction forces and awkward gripping surfaces, which compromise secure attachment and detachment.
Innovation Solution
The introduction of hinged zones in vial guidance flex members, distanced from the vial adapter top wall, allows for intentional hinging during telescopic snap fitting, reducing detachment reaction forces and enabling secure fits across all standard vial tube outer diameters for a specific vial crown outer diameter, with longer puncturing cannula and guidance flex members for enhanced shielding without compromising the snap fit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the downward depending skirt is dimensioned to terminate above a vial shoulder to accommodate all standard vial tube outer diameters, then the vial adapter can be used with all standard vial tube outer diameters, but misalignment occurs leading to tear formation in the vial stopper
Solution Approach 1:
The vial adapter incorporates a vial alignment feature (such as a rim or flange) at a specific location on the downward depending skirt that provides localized alignment guidance. This feature is positioned to engage with the vial shoulder at a predetermined location, ensuring co-axial alignment specifically at the critical interface between the adapter and vial, while the rest of the skirt maintains its telescopic snap fit functionality across different vial tube diameters.
2Measurement precision
If vial guidance flex members are made longer to provide guidance, then alignment is improved, but detachment reaction force increases opposing manual attachment force
Solution Approach 1:
The vial guidance flex members are segmented into multiple sections with varying lengths and flexibilities. The portions that contact the vial shoulder are optimized for guidance, while other sections are designed with different flex characteristics to control the detachment reaction force. This segmentation allows the guidance function and force management to be independently optimized.
Solution Approach 2:
The vial guidance flex members are designed with dynamic flex characteristics that allow them to adapt during the attachment process. The flex members provide rigid guidance when needed but can flex to reduce opposing forces during the snap fit operation, transitioning between stiff and flexible states based on the attachment phase.
3Speed
If the slope of the vial shoulder is made steeper to facilitate outward radial sliding of vial guidance flex members, then alignment speed is improved, but the detachment reaction force increases
Solution Approach 1:
The vial adapter is designed with adjustable or variable geometric parameters, including the slope of the vial shoulder engagement surface and the positioning of the vial alignment feature. These parameters can be optimized to provide a balance between alignment speed and detachment force, allowing the device to achieve rapid alignment while minimizing the opposing force during the snap fit operation.
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 a secure, uniform, and stable telescopic snap fit on injection vials of varying diameters, reducing detachment forces and providing a comfortable gripping surface, allowing for reliable use across all standard vial tube outer diameters for a particular vial crown diameter.
Implementation Method 1
the vial guidance flex members are outwardly radially flexed with respect to their vial adapter centerline at their junctures with their vial adapter top wall
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
Liquid drug transfer devices including a vial adapter having at least two non- adjacent vial retention flex members and at least two non-adjacent vial guidance flex members. The vial guidance flex members are each provisioned with a purpose design hinged zone distanced from a vial adapter top wall for intentionally being hinged thereat on telescopic snap fitting on an injection vial. Vial retention flex members can double as vial guidance flex members with the condition that their hinged zones are distal to their inwardly protruding vial retention ribs relative to the vial adapter top wall.