Unidirectional Valve Assembly for Face Masks
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Solution Overview
Problem
Conventional valve assemblies for face masks, such as circular diaphragm valves and cantilever flap valves, face challenges in minimizing airflow resistance and pressure differential required to open the valve, while also preventing leaks and ensuring effective sealing against hazardous airborne contaminants.
Innovation Solution
A unidirectional valve assembly with a non-circular valve orifice and a Y-shaped arrangement of cross members, featuring a flexible and cantilevered valve flap that is biased to a closed position against a valve seat, even when inverted, and requires minimal pressure differential to open during inhalation or exhalation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a circular diaphragm valve is used, then the valve can seal against the valve seat, but it creates significant airflow resistance and requires high pressure differential to open
Solution Approach 1:
The valve flap is divided into multiple segments or struts that can flex independently, allowing the valve to seal effectively while reducing the overall resistance to airflow through the valve assembly
Solution Approach 2:
Instead of a circular diaphragm configuration, the invention uses a linear or rectangular valve flap design that inverts the traditional sealing approach, reducing airflow obstruction while maintaining sealing capability
2Object-generated harmful factors
If a thin and flexible cantilever flap valve is used, then airflow resistance is reduced, but the valve can move away from the valve seat when inverted creating leak paths
Solution Approach 1:
The valve flap is designed with curved engagement surfaces that conform to the valve seat geometry, ensuring reliable sealing in any orientation including inverted positions while maintaining low airflow resistance
Solution Approach 2:
The valve assembly incorporates gravitational force as a sealing mechanism, where the weight of the valve flap itself helps maintain contact with the valve seat when inverted, eliminating the need for additional springs or weights
3Reliability
If cross members are added to support the valve flap, then sealing is improved, but airflow resistance increases
Solution Approach 1:
Cross members or struts are positioned only at critical locations where support is needed for sealing, rather than providing continuous support across the entire valve flap, thus maintaining low airflow resistance while ensuring reliable sealing at key engagement points
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 valve assembly effectively minimizes airflow resistance and pressure differential required to open the valve, while ensuring a secure seal against airborne contaminants, even in inverted orientations, thus enhancing wearer comfort and safety.
Implementation Method 1
The valve assembly typically includes a valve element configured to allow one-way or unidirectional flow of air into or out of the mask body in response to an inhalation or exhalation of air by the wearer which creates a pressure differential across the valve element
Implementation Method 2
The circular valve element is flexible and typically mounted at its centre such that the circumferential edge of the valve element is urged away from the valve seat when in an open position and back onto the valve seat when in a closed position
Data Source
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AI summary
The present application describes a unidirectional valve assembly (100) for a face mask, comprising a valve seat member (104) providing a continuous valve seat surface (156) surrounding a non-circular valve orifice (116), and a plurality of cross members (162) each extending partially across the valve orifice to meet at an intersection region; a substantially flexible and cantilevered valve flap (106) mounted at a fixed end region (108) to the valve seat member and configured to engage the valve seat when in a closed position to prevent air flow through the valve assembly; and a valve cover member (102) attached to the valve seat member and defining a plurality of apertures (178,180,182) in fluid communication with the valve orifice when at least a free end region (110) of the valve flap is in an open position with respect to the valve seat to allow air flow through the valve assembly, wherein the cross members (162) are arranged in a Y-shape configuration.