Eye Drop Dispenser Piston Hydraulic Force Amplification
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Solution Overview
Problem
Existing dispensers for administering eye drops are unfavorable due to their requirement for considerable operating forces and insufficient precision in dosing and application, making them unsuitable for precise handling.
Innovation Solution
A dosing assembly with a valve housing, piston sleeve, and spring device, where the effective surface area of the piston sleeve is significantly larger than the metering orifice, allowing for low-pressure release and high closing force to ensure precise dosing and microbiological sealing, combined with a conical design for enhanced sealing and a throttle to regulate flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional dispensers with small effective areas are used, then the device geometry is simple and compact, but considerable operating forces are required and dosing precision is insufficient
Solution Approach 1:
The patent applies hydraulic principles by creating a pressure amplification system where a small force applied to a large effective area of the piston is translated into a large force at the dosing opening through fluid pressure. The medium acts as the hydraulic fluid, transmitting pressure from the piston to the valve pin, enabling dosing with minimal operating force while maintaining precision.
Solution Approach 2:
The patent changes the physical parameters of the dosing system by introducing a piston with a large effective area (at least 50 times larger than the dosing opening cross-sectional area) and using fluid pressure as the transmission medium. This parameter change transforms the force requirement from direct mechanical action to hydraulic action, reducing operating force while improving dosing precision.
2Reliability
If the spring device applies high closing force to ensure microbiological sealing, then contamination is prevented, but the valve requires high operating force to open
Solution Approach 1:
The hydraulic pressure amplification system resolves this contradiction by allowing the spring to maintain high closing force for microbiological sealing while the user applies minimal force to the piston. The fluid pressure transmission converts the small piston force into sufficient force to overcome the spring's high closing force and open the dosing opening reliably.
Solution Approach 2:
The spring device acts as a counterweight providing constant closing force to ensure sealing, while the hydraulic system provides the counteracting opening force. The user's small input force on the piston generates a large counterforce through hydraulic pressure that overcomes the spring's closing force, enabling easy valve opening while maintaining reliable sealing when closed.
3Measurement precision
If the dosing opening is made small for precise dosing, then dosing accuracy improves, but the valve is more prone to contamination from liquid residues
Solution Approach 1:
The patent extracts the sealing function from the dosing opening itself and places it on the piston surface. The piston with its large effective area provides the sealing surface, allowing the dosing opening to remain small for precision while the sealing occurs at a different location (the piston-dosing opening interface), reducing contamination risk from liquid residues.
Solution Approach 2:
The piston acts as an intermediary between the user's input force and the dosing opening. It provides a large surface area for force application and creates a sealed interface with the dosing opening, allowing precise dosing through a small opening while minimizing contamination through the intermediary sealing mechanism.
4Force
If the effective area of the piston is made at least 50 times larger than the dosing opening, then low operating force is sufficient, but the device complexity increases
Solution Approach 1:
The piston serves multiple functions simultaneously: it provides the large effective area for force amplification, creates the seal with the dosing opening, transmits hydraulic pressure, and acts as the moving component for valve operation. This multi-functionality reduces overall device complexity despite the large area ratio, as one component accomplishes multiple critical tasks.
Solution Approach 2:
The patent merges the piston, seal, and force transmission elements into a single integrated component. The piston combines the force application surface, sealing surface, and movement mechanism, reducing the number of separate parts and simplifying the overall dosing assembly despite the sophisticated hydraulic principle employed.
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
Enables precise and easy handling with reliable microbiological sealing, minimizing contamination and ensuring accurate dosing, even with low user pressure, while preventing excessive medium discharge.
Implementation Method 1
a spring device being assigned to the valve pin... the spring device is designed to apply a high valve closing force
Implementation Method 2
The piston sleeve has a hydraulically active surface on which an opening force acts when pressure is applied to the medium accommodated in the dosing chamber
Implementation Method 3
the dosing opening is designed as a cone-shaped bore and the dosing pin has a cone-shaped extension attached to the front side, which completely fills the dosing opening in the closed state
Implementation Method 4
the dosing opening is preceded by a throttle which reduces a volume flow from a media reservoir to the dosing opening
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The dispenser has a medium storage (2) comprising a dosage opening (4) and provided for hand operation. The medium storage is limited in sections by flexibly designed wall sections (5) and by dimensionally stable retaining plates (6, 10), where the retaining plates are provided as a holder for applying operating forces on the medium storage. The dosage opening is formed at a dosage nozzle (7), and the wall sections are made from a plastic material e.g. polyethylene, where the retaining plates are arranged opposite to one another and the nozzle is attached to one of the retaining plates. An independent claim is also included for a dosage assembly for a dispenser.