Foam Pump with Nested Cylinders to Reduce Axial Profile
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Solution Overview
Problem
Foam pumps used in bag-in-box dispensers have a high profile, leading to trauma on flexible plastic bags and increased risk of leakage due to axial offset between air and liquid cylinders, which can result in product waste and hazardous conditions.
Innovation Solution
A dual air and liquid cylinder foam pump design with a collapsible air and liquid piston assembly, featuring a mixing chamber with rotational air flow channels and a self-closing liquid outlet valve, reduces the axial offset and prevents leakage by ensuring turbulent mixing and efficient dispensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If axial offset between air cylinder and liquid cylinder is increased to accommodate both cylinders, then both cylinders can be concentrically arranged, but the axial length of the pump increases resulting in high profile
Solution Approach 1:
The patent merges the air cylinder and liquid cylinder into a single integrated chamber, eliminating the need for separate concentric cylinders with axial offset. This consolidation reduces the overall axial length of the pump while maintaining the functionality of both air and liquid delivery systems.
Solution Approach 2:
The patent nests the liquid delivery system within the air delivery system by positioning the liquid piston and liquid outlet valve inside the air chamber. The liquid piston shaft extends through the air piston, and the liquid outlet valve is located within the air chamber, creating a nested configuration that minimizes axial length.
2Ease of operation
If high profile pump extends into flexible plastic bag, then pump can be mounted in bag-in-box dispenser, but trauma to bag occurs during transport and handling increasing risk of puncture
Solution Approach 1:
The patent extracts the dip tube from the pump design by positioning the liquid inlet valve directly at the bottom of the liquid chamber, allowing the liquid inlet to communicate with the bottom of the fluid reservoir without requiring a long dip tube that would extend into and potentially puncture the flexible bag.
Solution Approach 2:
The patent inverts the traditional pump orientation by positioning the liquid outlet above the liquid inlet, allowing the pump to function in an inverted configuration where the liquid flows downward into the pump chamber. This inversion eliminates the need for a long dip tube extending into the bag.
3Ease of operation
If pump is used in inverted orientation with fluid source above pump, then dispensing is enabled, but catastrophic leakage occurs if piston sticks or outlet valve fails
Solution Approach 1:
The patent incorporates a self-closing liquid outlet valve that automatically closes when liquid flow stops or pressure equalizes, preventing catastrophic leakage before it can occur. The valve is designed to close upon loss of pressure differential, providing a fail-safe mechanism that operates automatically without requiring piston movement.
Solution Approach 2:
The liquid outlet valve is designed as a self-closing mechanism that automatically seals the liquid outlet when liquid flow ceases or pressure equalizes between the liquid chamber and atmosphere. This self-service feature eliminates the need for active control or manual intervention to prevent leakage in inverted orientation.
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 achieves improved foam generation, reduces the risk of bag puncture, and prevents leakage by eliminating the need for a dip tube and minimizing axial offset, resulting in a lower profile and enhanced operational safety.
Implementation Method 1
each of the air passageways is configured to impart a rotational flow to air entering the mixing chamber
Implementation Method 2
causing a turbulent mixing thereof in the mixing chamber of the foam pump
Implementation Method 3
the collapsible air chamber and the collapsible liquid chamber are reduced in volume such that air is expelled from the collapsible air chamber
Implementation Method 4
A biasing member urges the piston assembly to a non-actuated position
Data Source
AI summary
A foam pump for generating a foam including a foamable liquid and air has dual, coaxial air and liquid cylinders, each having a respective air and liquid piston which move together during a dispensing operation. In certain embodiments, the air and liquid cylinders are modular, separately formed components. In certain embodiments, a plurality of differently sized, liquid cylinders are provided, each with a corresponding liquid piston which is complementary in size thereto. Providing multiple differently sized liquid cylinder and piston components allows the pump to be configured to deliver a desired quantity of foamable liquid and/or a desired liquid-to-air ratio in the foam output of the pump. The differently sized liquid cylinder and piston components can be used interchangeably with a common air cup design and other common pump components, the modular construction allowing custom pump output configurations to be provided with minimal tooling investment per output size.