Diaphragm Valve for Dual Ink Cartridges and Backflow Prevention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Printing fluid supply systems face issues with fluid spillage and air ingestion during printhead removal due to remnant pressure in fluid pipes, and existing solutions do not effectively prevent backflow between dual cartridges of the same fluid type.

Innovation Solution

A printing fluid supply system that includes a shared pressurized air source controlled by a selection valve and a three-way, two-position mechanical valve with a diaphragm to selectively couple a pressurized cartridge to the printhead while sealing an unpressurized one, preventing backflow and regulating pressure during printhead removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a dual printing fluid supply cartridge system is used to enable cartridge replacement without interrupting printing, then operational continuity is improved, but fluid backflow between cartridges causes spillage and air ingestion during printhead removal

Engineering Contradiction:

Improveoperational continuityVSAvoidfluid spillage and air ingestion

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

A three-way, two-position mechanical valve with diaphragm is introduced as an intermediary component between the dual cartridges and the printhead. This valve selectively couples the pressurized cartridge to the printhead while sealing the unpressurized cartridge, preventing direct fluid communication between cartridges and eliminating backflow during printhead removal.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The valve system creates different fluid connection states for different cartridges based on their pressurization status. The pressurized cartridge maintains active fluid supply to the printhead, while the unpressurized cartridge is locally sealed off, preventing harmful backflow while maintaining operational continuity.

Inventive Principle:

Principle #3Local quality

2Productivity

If pressurized air is used to pump printing fluid from the cartridge to the printhead, then fluid flow is improved, but remnant pressure in fluid pipes causes fluid spillage during printhead removal

Engineering Contradiction:

Improvefluid flowVSAvoidfluid spillage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The three-way, two-position mechanical valve acts as a mediator that controls the pressurized fluid path. When the printhead is removed, the valve seals the pressurized cartridge and fluid lines, preventing remnant pressurized fluid from spilling while maintaining normal fluid flow during printing operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If check valves are installed at each cartridge outlet to prevent backflow, then fluid backflow is reduced, but fluid spillage during printhead removal persists due to remnant pressure

Engineering Contradiction:

Improvebackflow preventionVSAvoidfluid spillage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The three-way, two-position mechanical valve serves as a more effective intermediary than simple check valves. It provides active control over the fluid path, sealing both cartridge outlets when the printhead is removed, thereby preventing both backflow between cartridges and spillage from remnant pressure in the fluid lines.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If a valve system is introduced to prevent backflow between cartridges, then backflow prevention is improved, but device complexity increases

Engineering Contradiction:

Improvebackflow preventionVSAvoidvalve system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The three-way, two-position mechanical valve operates automatically based on pressure differential between the cartridges. The diaphragm responds to pressure changes, selectively coupling the pressurized cartridge to the printhead without requiring external control mechanisms, thereby achieving reliable backflow prevention with relatively simple device architecture.

Inventive Principle:

Principle #25Self-service

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 system ensures consistent fluid flow, prevents fluid spillage and air ingestion, and allows for seamless cartridge replacement by maintaining controlled pressure and preventing backflow between cartridges, enhancing operational efficiency and maintenance.

Implementation Method 1

selectively couple a pressurized printing fluid supply cartridge to the printhead and seal an unpressurized printing fluid supply cartridge

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a spring that applies a force upon the diaphragm

Methodology Applied

Scientific EffectElastic force: Spring

Data Source

PatentEP3233502B1Valves for printing fluid supply systems

Publication Date: 2022.01.05 HEWLETT PACKARD DEVELOPMENT COMPANY LP

Figure 1
Figure 2
Figure 3

AI summary

In an example, a valve for a printing fluid supply system is disclosed. In this example, the valve includes two rigid shells to provide connections to a first printing fluid supply cartridge, a second printing fluid supply cartridge and a printhead. Further, the valve includes a diaphragm with sealing elements disposed between the two rigid shells to selectively couple one of the first printing fluid supply cartridge and the second printing fluid supply cartridge to the printhead and seal other printing fluid supply cartridge using the sealing elements.