Diaphragm Non-Return Valve for Breathing Gas Leakage Control

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Solution Overview

Problem

Existing breathing gas regulators for self-contained breathing apparatuses face issues such as increased bulk, weight, and restricted user head movement due to complex flushing mechanisms, and they suffer from continuous gas leakage, making it difficult to detect unintended leaks and leading to reduced cylinder life and compliance challenges.

Innovation Solution

A diaphragm for lung demand regulators featuring a non-return valve that opens only when a specific pressure differential threshold is exceeded, allowing gas flow during exhalation while preventing flow during inhalation or latent periods, thereby reducing gas leakage and maintaining positive pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a flushing mechanism with dedicated ducting is used to flush contaminants away from the diaphragm, then contaminant permeation through the diaphragm is reduced, but the space envelope, bulk, and weight of the regulator increase significantly

Engineering Contradiction:
Improvecontaminant permeation reductionVSAvoidregulator weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent extracts the flushing function from a separate dedicated ducting system and integrates it into the diaphragm structure itself. The diaphragm includes a central opening that allows exhaled gas to flow directly over the diaphragm surface, eliminating the need for external flushing ducts and reducing overall regulator weight while maintaining contaminant removal effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the flushing function with the diaphragm structure by incorporating a central opening directly in the diaphragm. This integration allows the diaphragm to serve dual purposes: as the primary sealing element and as the flushing conduit, eliminating the need for separate flushing components and reducing weight.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a flushing mechanism with dedicated ducting is used to flush contaminants away from the diaphragm, then contaminant permeation through the diaphragm is reduced, but the regulator cannot rotate relative to the mask, restricting user head movement

Engineering Contradiction:
Improvecontaminant permeation reductionVSAvoiduser head movement freedom
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent removes the rigid flushing ducting system that constrained regulator rotation and replaces it with a flexible flushing mechanism integrated into the diaphragm. The central opening in the diaphragm allows gas flow without requiring rigid external ducts, enabling the regulator to rotate freely with the mask while maintaining flushing effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the regulator is maintained at positive pressure with a cover lifted by pressure differential, then gas flow control is achieved, but continuous leakage occurs making it difficult to detect unintended leaks and depleting the gas cylinder more quickly

Engineering Contradiction:
Improvegas flow controlVSAvoidgas cylinder depletion rate
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent implements periodic flushing action through the diaphragm's central opening that opens and closes based on pressure differential changes during breathing cycles. This periodic flow control mechanism allows gas to be flushed during exhalation when pressure differential is sufficient, while preventing continuous leakage during inhalation and latent periods, thus reducing overall gas depletion while maintaining flow control.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The diaphragm's central opening automatically responds to pressure differential changes without requiring external control mechanisms. The opening permits gas flow when pressure differential exceeds a threshold (during exhalation) and closes when pressure differential is below the threshold (during inhalation), providing self-regulating flow control that prevents continuous leakage while maintaining effective flushing.

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 solution effectively reduces gas leakage, maintains continuous breathing gas flow, and allows for improved user mobility by eliminating the need for complex flushing mechanisms, thus enhancing the reliability and efficiency of breathing gas regulators.

Implementation Method 1

a diaphragm configured to move responsive to a pressure differential between the first and second faces... a non-return valve configured to control gas flow through the opening... wherein the non-return valve is biased to prevent all flow through the opening whilst the pressure differential is below a threshold and permit flow from the first face to the second face whilst the pressure differential is above a threshold

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4570326A1Lung demand regulator device and diaphragm
Publication Date: 2025.06.18 DRAGER SAFETY AG & CO KAAA
  • EP4570326A1 patent drawingFigure 1
  • EP4570326A1 patent drawingFigure 2
  • EP4570326A1 patent drawingFigure 3A

AI summary

There is disclosed a diaphragm for a lung demand regulator device, the diaphragm comprising: a first face and a second face, the diaphragm being configured to move responsive to a pressure differential between the first and second faces; an opening extending between the first face and second face; and a non-return valve configured to control gas flow through the opening; wherein the non-return valve is biased to prevent all flow through the opening whilst the pressure differential is below a threshold and permit flow from the first face to the second face whilst the pressure differential is above a threshold. Also disclosed is a lung demand regulator device comprising a diaphragm and a breathing apparatus.