Foam Dispenser Pump Passageway Layout to Reduce Dripping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Many liquid dispensers, both foaming and non-foaming, experience issues with liquid dripping when left unused due to coalescence of foam or liquid in the pump chamber, leading to unwanted leakage.
Innovation Solution
A piston pump design with a sump chamber and a passageway that extends upwardly from the sump outlet, allowing fluid to flow upward and then downward to a dispensing outlet, which is positioned below the sump outlet, reducing dripping by requiring liquid to reach a specific height before flowing out.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the pump chamber is left open to the outlet, then liquid can flow freely from the chamber to the outlet, but liquid drips under gravity from the chamber out of the outlet when the pump is unused
Solution Approach 1:
The passageway is inverted to extend upwardly from the sump outlet instead of downwardly. This inversion creates a barrier against gravity-driven dripping while still allowing pump-induced flow to reach the outlet during normal operation
Solution Approach 2:
The upwardly extending passageway portion acts as an intermediary barrier between the sump chamber and the outlet. Liquid must overcome gravity to reach this intermediate height, preventing spontaneous dripping while allowing controlled discharge during pumping cycles
2Reliability
If foam is drawn back into the pump during unused periods, then the pump maintains readiness for next use, but the foam coalesces into liquid and air causing liquid level to rise and drip from the outlet
Solution Approach 1:
The upwardly extending passageway converts the harmful effect of coalesced liquid into a beneficial barrier. The liquid that forms from coalescence must still overcome the gravitational barrier of the upward passageway, preventing dripping even when foam breaks down during storage periods
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 minimizes dripping between dispensing cycles by ensuring that liquid in the sump must reach a certain height before flowing out, preventing unwanted leakage and maintaining the pump's functionality.
Implementation Method 1
a sump is defined in a chamber into which sump liquid in the chamber flows due to gravity
Implementation Method 2
dripping from the dispensing outlet of the pump between cycles of dispensing can be reduced. In the preferred embodiments, dripping of liquid from the sump requires liquid to achieve a height in the sump above the height to which fluid in the passageway must be raised to flow downwardly to the dispensing outlet
Data Source
AI summary
The present invention provides a piston pump for liquid in which a sump is defined in a chamber into which sump liquid in the chamber flows due to gravity. A passageway leads from an outlet of the sump out of the chamber to a dispensing outlet. The dispensing outlet is at a height below the height of the sump outlet and fluid to exit the sump flows from the sump outlet upwardly in a first portion of the passageway to a height above the sump outlet then downwardly to the dispensing outlet. The chamber and its sump is defined between a piston chamber-forming member defining the chamber to be downwardly opening and a piston forming element axially slidable in the chamber.