Multi-Diaphragm Foam Pump Design for Consistent Air-to-Liquid Ratio

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing liquid dispenser systems fail to effectively dispense liquids as a foam product with a consistent air-to-liquid ratio, leading to inefficiencies in creating and delivering a foamy mixture of soap, sanitizer, or lotion.

Innovation Solution

The development of sequentially activated multi-diaphragm foam pumps, which include a molded multi-chamber diaphragm with a liquid pump chamber and multiple air pump chambers, operate in conjunction with a drive motor to mix and dispense foamable liquids with air, achieving a controlled air-to-liquid ratio through a rotatable drive mechanism and mixing chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional mechanical piston foam pumps are used to mix liquid and air, then foam can be dispensed, but the air-to-liquid ratio is inconsistent and energy consumption is high

Engineering Contradiction:
Improveair-to-liquid ratio consistencyVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The pump chamber is segmented into multiple diaphragms (first diaphragm for liquid, second and third diaphragms for air) that operate independently but sequentially. This segmentation allows precise control over the amount of liquid and air pumped, ensuring consistent air-to-liquid ratio while reducing the energy required compared to a single large piston mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The foam pump uses periodic sequential activation of diaphragms driven by a rotating mechanism with eccentric cams. The first cam activates the first diaphragm to pump liquid, followed by the second cam activating the second diaphragm to pump air, then the third cam activating the third diaphragm to pump additional air. This periodic sequential action ensures consistent mixing ratios and reduces energy consumption by only activating diaphragms when needed in the cycle.

Inventive Principle:
Principle #19Periodic action

2Productivity

If a rotary liquid pump with resilient housing is used, then liquid can be pumped, but foam mixing and dispensing is not effective

Engineering Contradiction:
Improvefoam dispensing efficiencyVSAvoidfoam consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention merges the liquid pumping function and air pumping function into a single integrated foam pump assembly. The first diaphragm handles liquid pumping while the second and third diaphragms handle air pumping, and all three are combined in one pump chamber that feeds into a common outlet. This merging ensures that liquid and air are mixed and dispensed together as foam, improving foam dispensing efficiency and consistency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-diaphragm foam pump assembly serves multiple functions: the first diaphragm pumps liquid, the second diaphragm pumps air, the third diaphragm pumps additional air, and the rotating mechanism with eccentric cams coordinates all three diaphragms. This multi-functionality within a single assembly enables effective foam mixing and dispensing that a single-function rotary pump cannot achieve.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If multiple diaphragms are used for sequential pumping, then foam quality improves, but device complexity increases

Engineering Contradiction:
Improvefoam consistencyVSAvoidpump structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple diaphragms (first, second, and third diaphragms) are merged into a single pump chamber assembly that shares common structural elements. The diaphragms are arranged within the same housing and share the outlet valve and mixing chamber connection, reducing the overall complexity compared to having separate pump units for each diaphragm.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotating mechanism with multiple eccentric cams serves as a universal actuator for all three diaphragms. A single rotating shaft with three eccentric cams coordinatedly activates the first, second, and third diaphragms in sequence, reducing the need for multiple separate actuators and simplifying the control system while maintaining precise foam consistency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution enables the efficient creation and dispensing of a foamy mixture with a controlled air-to-liquid ratio, enhancing the quality and consistency of the foam product, reducing energy consumption, and improving operational efficiency compared to conventional mechanical piston foam pumps.

Implementation Method 1

a first diaphragm for pumping liquid into a mixing chamber, a second diaphragm for pumping air into the mixing chamber, and a third diaphragm for pumping air into the mixing chamber

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

a rotatable drive mechanism including a first cam for sequentially actuating the first diaphragm, a second cam for sequentially actuating the second diaphragm, and a third cam for sequentially actuating the third diaphragm

Methodology Applied
Scientific EffectEccentric: Eccentric

Data Source

PatentEP3439521B1Sequentially activated multi-diaphragm foam pumps, refill units and dispenser systems
Publication Date: 2022.11.02 GOJO IND INC
  • EP3439521B1 patent drawingFigure 1
  • EP3439521B1 patent drawingFigure 2
  • EP3439521B1 patent drawingFigure 2A

AI summary

An exemplary foam dispenser includes a housing, a drive motor and a foam pump operatively coupled to the drive motor. The foam pump is secured to the housing and the foam pump includes a housing and a molded multi-chamber diaphragm. The molded multi- chamber diaphragm includes a liquid pump chamber, two or more air pump chambers; and an outlet valve. A mixing chamber is included and located downstream of the outlet valve for mixing foamable liquid from the liquid pump diaphragm with air from each of the two or more air pump chambers. In addition, a foam cartridge and an outlet for dispensing foam are also included.