Floating Piston Metering Dispenser with Liquid Seal Film
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Solution Overview
Problem
Dosing dispensers with drag piston systems require high precision and complex manufacturing, leading to high costs and limited container shapes, and are sensitive to leaks and solid particles, which can cause malfunctions.
Innovation Solution
A 'floating' piston system with a clearance fit that uses a pasty substance to form a sealing film, allowing for a simpler and less sensitive design, suitable for substances like wax or lip care products, where the piston adheres to the container wall and maintains a sealing film without requiring exact fit or high precision, and can handle solid particles without frictional issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a drag piston system with airtight sealing is used, then reliable pump operation and optimal residual emptying are achieved, but manufacturing precision requirements and device complexity increase significantly
Solution Approach 1:
The patent introduces a liquid sealing film as an intermediary substance between the piston and container wall. This liquid sealant fills the clearance gap (approximately 0.02-0.2 mm) between the piston surface and container inner wall, creating an effective seal without requiring precise mechanical fit. The liquid sealing film mediates the sealing function while allowing mechanical tolerances, thus resolving the contradiction between reliability and manufacturing precision.
2Reliability
If a drag piston system with sealing lips is used, then airtight sealing is achieved, but friction forces increase and movement becomes difficult
Solution Approach 1:
The patent replaces the mechanical sealing system (sealing lips and contact-based sealing) with a liquid-based sealing mechanism. Instead of relying on mechanical contact between piston and container wall, the system uses a liquid sealing film that conforms to the clearance gap. This substitution eliminates the high friction forces associated with mechanical sealing lips while maintaining effective sealing, as the liquid sealant creates capillary and adhesive forces rather than mechanical friction.
3Measurement precision
If small container diameters are used, then product dosage precision is improved, but the relationship between piston circumference and piston area becomes unfavorable increasing friction
Solution Approach 1:
The liquid sealing film acts as a mediator that decouples the relationship between piston dimensions and frictional resistance. In small diameter containers, the clearance gap between piston and wall remains constant (0.02-0.2 mm), and the liquid sealant fills this gap uniformly. This allows the piston to move with consistent low friction regardless of container size, as the liquid sealant provides sealing and lubrication without the frictional resistance that would otherwise scale with piston circumference.
4Ease of manufacture
If a vent opening with stopper is added to the container, then air can escape during filling, but device complexity and number of parts increase
Solution Approach 1:
The patent extracts the venting function from the mechanical domain (vent opening with stopper) and integrates it into the liquid sealing system. The liquid sealant allows air to pass through during filling operations when the piston is positioned to permit venting, then automatically seals when the piston moves into its operational position. This extraction of the venting function from mechanical components eliminates the need for separate vent openings and stoppers, reducing device complexity while maintaining ease of filling.
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
This design reduces manufacturing costs and complexity, allows for various container shapes, and prevents ambient air from entering, ensuring reliable operation and efficient dispensing without the need for precise tolerances or sealing lips, making it cost-effective for small diameter containers.
Implementation Method 1
The pasty substance adheres well to the surface of the piston and is pulled along by it when the system is emptied. Due to the adhesion of the component to the container wall, the sealing film thus formed is maintained between the piston and the container wall.
Implementation Method 2
When dosing, the pump sucks the component out of the container and the resulting negative pressure tightens the piston.
Data Source
Figure 1
Figure 2~6
Figure 7~12
AI summary
For a cost-effective design of a metering dispenser for dispensing a substance (12), which is poured into a container (1) that is open at an end face and which can be removed from the container (1) by means of a pump unit (10), wherein a piston (5) is inserted in the container (1), the piston (5) has smaller dimensions than the inner contour of the container (1) and a film (5a) of the pasty substance (12) is provided in order to seal between the piston (5) and the inner contour of the container (1).