Drip Device Piston Sealing Mechanism for Contamination Prevention
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Solution Overview
Problem
Drip devices used in pharmaceuticals face issues with contamination due to seal loss during actuation, leading to potential deformation of nasal or pediatric spray heads and risk of external matter entering the device.
Innovation Solution
A drip device design featuring a piston head and connecting rod mechanism that blocks and opens a drip port using a plug, ensuring the liquid outlet is sealed when not in use and preventing external contamination by maintaining pressure within the infusion channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plug is used to seal the dispensing orifice, then contamination between actuations is avoided, but the plug exerts force on the dispensing head causing deformation and seal loss
Solution Approach 1:
A resilient sealing element (second seal) is introduced as an intermediary between the plug and the dispensing orifice. This seal absorbs the mechanical stress and thrust forces, preventing direct transmission to the thin-walled spray head while maintaining effective sealing. The resilient nature of this intermediate element allows it to deform elastically under plug pressure, ensuring continuous contact and seal integrity without compromising the structural strength of the dispensing head.
2Reliability
If the seal is actuated at the end of the return stroke, then sealing is ensured, but contamination may occur during the time slot between dispensing end and closure
Solution Approach 1:
The sealing action is performed in advance during the actuation stroke itself, rather than waiting until the end of the return stroke. The plug is designed to engage and begin sealing the dispensing orifice while the piston is still moving downward, creating an overlap period where sealing is established before dispensing completely ends. This preliminary sealing action eliminates the contamination vulnerability window by ensuring the seal is in place before any potential backflow or external contamination can occur.
3Reliability
If the plug is actuated by a spring to ensure sealing, then sealing force is provided, but the thrust can cause deformation of thin-walled spray heads
Solution Approach 1:
A resilient sealing element (second seal) is positioned between the plug and the dispensing orifice to absorb and distribute the spring thrust forces. This flexible seal component deforms elastically under the spring pressure, maintaining effective sealing contact while preventing the transmission of high-magnitude thrust forces to the thin-walled spray head structure. The resilient nature of this intermediate sealing element allows it to accommodate the spring force without causing permanent deformation to the spray head.
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 design effectively reduces the risk of external foreign matter contaminating the liquid agent by ensuring the plug consistently blocks the drip port, maintaining a sealed environment and preventing air or foreign matter from entering the device.
Implementation Method 1
a compression spring is placed between the piston head and the connecting block, and the compression spring pushes the connecting block downward to make the plug block the drip port
Implementation Method 2
when the piston head inserts into the piston chamber, the outer side wall of the piston head is slidably sealed with an inner side wall of the piston chamber
Implementation Method 3
an upper end of the second connecting tube extends into the first connecting tube and is slidably sealed with an inner side wall of the first connecting tube
Data Source
AI summary
The present disclosure relates to a drip device, including a drip bottle having a bottle mouth facing downward, since the bottle mouth faces downward, a liquid in the drip bottle is charged into a first connecting tube, an infusion channel, and a piston chamber when a pressing head is not pushed upward, a plug blocks a drip port, and the liquid cannot flow out from the drip port. When the pressing head is pushed upward to move the pressing head upward relative to a connecting cover, a piston head inserts into a piston chamber to separate the infusion channel from the piston chamber, the pressing head continues to move upward, a volume of the piston chamber is compressed, the liquid in the piston chamber will flow back to the drip bottle through a liquid outlet, and a volume of the infusion channel is also compressed.