US2954793A - Pressure compensated inhalationexhalation valve for pressure breathing mask - Google Patents

Description

Oct. 4, 1960 H. w. SEELER PRESSURE COMPENSATED INHALATION-EXHALATION VALVE FOR PRESSURE BREATHING MASK 2 Sheets-Sheet 1 Filed Sept. 12, 1958 'nn l v f NW] l Oct. 4; 1960 H. w. SEELER PRESSURE COMPENSATED INHALATION-EXHALATION VALVE FOR PRESSURE BREATHING MASK 2 Sheets-Sheet 2 Filed Sept. 12, 1958 llL w v a PRESSURE COMPENSATED INHALATION- 'EXHALATION VALVE FOR PRESSURE BREATHING MASK Henry W. *Seeler, Dayton, Ohio, assignor to the United States of America as represented by the Secretary of the Air Force Unite The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

This invention relates to a valve assembly, and more particularly to a pressure compensated inhalation and exhalation valve assembly for pressure breathing in a high altitude mask, of the general type as shown in my Patent No. 2,820,469, dated January 21, 1958.

High altitude masks in use currently have three valves built into them. This causes the masks to be unnecessarily large and uncomfortable. The improved valve assembly as shown in my above referred to patent took over the work of these valves by compactly combining the function of an inhalation valve and a pressure compensated exhalation-inhalation valve with the result that breathing masks could be made smaller and lighter. This has an important effect on the ability of the wearer to usethe mask for long periods of time without objectional discomfort. Accordingly a principal feature of this invention is to provide a compact valve assembly for a breathing mask that combines the functions of an inhalation valve and a fully pressure compensated and balanced exhalation valve.

A further object of this invention is the provision of an improved valve assembly designed so that low tempera: ture oxygen supplied to the valve assembly can not freeze 'the exhalation moisture in the valve assembly and cause It is therefore an object of this invention to provide asupplementary pressure chamber and diaphragm for the exhalation valve for controlling the movement of the exhalation valve between exhalation and nonexhalation positions.

A further object includes the provision of means for compensating variations of pressure in the supplementary pressure chamber due to variations of pressure in'the inhalation chamber during inhalation and exhalation.

.-A further object is the provision of a dual diaphragm structure for closing the supplemental pressure chamber comprising means for mounting the exhalation valve for concentric axial movement, and including a restricted bleed port for connecting the supplemental chamber in restricted communication tothe inhalation chamber.

These and other objects of this invention will become more apparent when read in the light of the following specification and. accompanying drawings in which like reference characters refer to like parts in the several figures.-

iFigure '1 is aside elevation of the'improved valve asatent sembly disclosing the annular exhalation port and showing the mask receiving groove and the oxygen hose receiving portion. A portion of the mask and oxygen hose are shown in the dotted lines in Figure 3.

Figure 2 is an end elevation of the valve assembly look ing toward the mask receiving end. I

Figure 3 is a longitudinal sectional view through the assembly, taken about on the plane indicated by line 3-3 in Figure 2 but including a portion of the mask and oxygen hose, which are shown in dotted lines.

Figure 4 is a detail cross sectional view through my improved dual annular diaphragm ring. 2

Referring to the drawings by reference numerals the improved compensated inhalation and exhalation valve assembly is indicated generally by the reference numeral 1 comprising an annular tubular housing or casing 2 having an inner or mask end 3 and an outer or oxygen supply end 4 (see Figure 3). The housing 2 has a tubular stem portion or oxygen supply conduit 5 adapted to be secured to an oxygen supply hose 6 and the inner or mask end 3 is formed with an annular mask receiving groove 7 adapted to be inserted in a suitable hole prepared in the oxygen mask 8.

An inhalation chamber 9 and an exhalation chamber 10 in the housing 2 are separated by a movable dividing Wall 11 so that the exhalation chamber 10 is at the inner end of the housing 2 and the inhalation chamber 9 is near the outer end. This dividing wall 11 consists of an annular inhalation valve 12 and an annular exhalation valve 13. The valve 13 includes a rigid tubular support The periphery 21 of the inhalation'valve .12 is adapte V to make a one way sealing contact with the valve seat 22 on the edge of the exhalation valve portion 20 and close off the inhalation port23 connecting the inhalation and exhalation chambers 9 and 10.

As seen in Figure 3 the inhalation valve opens whenever the relative pressure in the inhalation chamber9 exceeds the pressures in the exhalation chamber 10. This equalizes the gas pressures in both chambers 9 and 10 nnular valve seat 24 formed in the bo y f h housing 2 of the valve assembly. The exhalation chamber 10. communicates with the ambient air through ports 25 which are opened and closed by the exhalation valve 13.

On the opposite end 25 of the exhalationValVe portion 20 an annular ring shaped dual diaphragm 15' is mounted. The diaphragm 15 as seen in Figures 3. and

4 comprises a pair of concentric U-shaped'in cross section resilient diaphragm portions orv rings. The outer U-shaped in cross section ring is indicated at 28 while the integral concentric inner ring diaphragm is indicated The dual diaphragm 15 is secured intermediate its inner. and outer edges to the end of the tubular support portion 26 of the exhalation valve structure by suitable means such as by the retaining ring 36, [The outer periphery of.

the outer ring 28 is provided with an annular mounting head 31 which snugly fits the annulargroove in' the "enretains the bead 31 in its groove or channel. p i The inner edge periphery of the inner ring 29 of the larged portion 32 of the housing 1 and a sealing ring 33" annular mounting bead 34 which is seated in an annular groove 35 in the tubular sleeve or ferrule 36 seated in thetubular stem 5 and extending inwardly toward the inhalation chamber 9 and formed with an inturned flange 3-7'forming a spring seat.

An annular ring or ferrule 39 snugly fitted in the inner bore of the tubular sleeve 36 is locked therein by a snap ring 39 seated in suitable complemental grooves and this ferrule 39 retains the inner bead 34 in the sleeve 36, which sleeve 36 for all practical purposes can be considered an inner tubular extension of the oxygen supply conduit portion 5 extending into or at least toward the inhalation chamber 9. The two concentric diaphragm ring portions 28 and 29 with the right hand portion 32 of the housing 2 and the sleeve 36 form a closed pressure chamber 40 located toward the outer or oxygen supply receiving end 4 of the valve assembly.

This chamber 40 is provided with a restricted or small communicating passage 41 therefrom into the interior of the inhalation or oxygen supply passage 44.

Thus, the. inner edge of the flexible inner U-shaped diaphragm portion 29 is secured to the tubular extension or stem 36 and the outer edge of the flexible outer diaphragm portion 28 is secured to the intermediate portion 32 of the housing while the annular intermediate portion 42 of the diaphragm is secured to the right hand end of the exhalation valve 13, for purposes that will subsequently appear as the description proceeds. Relative pressure in the closed chamber 40 prevents improper functioning and chatter of the exhalation valve, also the use of the dual diaphragm 15 provides means forming a concentric floating connection between the outer enlarged intermediate portion 32 of the housing 2 and the inwardly spaced inwardly extending extension 36 of the outer end 4'of the tubular stem portion 5 of the casing 2. This supports the exhalation valve 13 in a resilient flexible concentric spaced floating relation to the exhala tion valve seat 24 and in radially spaced relation to the housing (except at the valve seat 24) and forms damping means to prevent chatter of the inhalation, exhalation valve structure, the spaced relation between the exhalation valve 13 and the casing 2 reducing to a minimum extent the danger of moisture accumulation and freezing of the movable, parts which might cause malfunctioning of the assembly.

The concentric diaphragmportions or rings 28 and 29 are molded from rubber-like material and are very thin and substantially semicircular in cross sectionsin planes perpendicular to the plane of the diaphragm and transverse to its periphery.

chamber, plus a pressure increment suflicient to overcome the biasing means 43.

The inhalation valve diaphragm 16 is preferably molded of light flexible rubber-like material and is formed with an annular U-shaped flexing ring 45 as shown on Figure 3.

In the inhalation cycle the" exhalation valve portion 13 remains on its seat 24 and theinhalation valve diaphragm 16 unseats, the peripheralportion 21 leaving the'seat 22, and oxygen from the inhalation chamber 9' enters through the exhalation chamber into the mask 8 for inhalation by the wearer.

The closed pressure or balancing chamber 40' was formerly under :balancedpressurewith the oxygen pressure in the inhalation chamber through the restricted communicating port 41; so that upon inhalation when a reduction in the oxygen pressure in the inhalation chamber occurs the pressure in the chamber 40 can not escape immediately and assists in retaining the exhalation valve 13 on its seat.

When exhalation from the wearer of the mask 8 occurs.

the flapper inhalation valve 12-16 closes as pressure builds up in the exhalation chamber moving the exhalation valve 13' to the right as shown in Figure 3 to discharge through the ports 25 to the ambient air. Simultaneously, pressure in the pressure chamber 40 leaks through port 41 which causes damping action of the exhalation valve against vibration and chatter.

When pressure in the exhalation chamber 10 is reduced sufficiently the spring 43 plus the pressure admitted This dampens the movement of the exhalation valve and eliminates chatter or flutter. The degree of damping can belcontrolled by the size of the port 41 The embodiment of the invention herein shown and 'describedis to be regarded as illustrative only and it is to be understood that the invention is susceptible of variations, modifications and changes within the scope of the appended claims.

way the valve assembly is always completely pressure compensated throughout all pressure ranges and is bal-' anced by the dual diaphragm ring 15 and the pressure in the closed chamber 40 in restricted communication with the oxygen intake or supply passage 44. g

It should be observed that the eflective area of the exhalation valve 13 in the exhalation chamber 10 is that area confined by the valve seat 24. The effective area on the opposite side of the exhalation valve 13 in the inhalation chamber 9 and in the'chamber 40 is equal to theetfective area of the exhalation valve in the exhalation chamber. Since these two areas are equal, a pressure in,

the exhalation chamber suflicient to open the exhalation valve rnust be as great as the pressure in the inhalation I claim:

1. A compensated inhalation and exhalation valve assembly for pressure breathing in a high altitude mask comprising; a housing having inhalation and exhalation chambers and an inner tubular extension extending into said inhalation chamber and an exhalation port connecting said exhalation chamber with the ambient air, a dividing wall separating said inhalation and exhalation chambers, said dividing wall including an exhalation valve operating to open and close said exhalation port, the effective area of said exhalation valve in said exhalation chamber being equal to the eifective area of said exhalation valve in said inhalation chamben biasing means connected to said exhalation valve and said housing for closing said exhalation port, said dividing Wall further including an inhalation valve, the exhalation pressure necessary to open said exhalation valve against the forces of said biasing means is equal to the pressure entering thevalve assembly plus a pressure increment suflicient to overcome said biasing means, said housing having a closed chamber formed with a restricted port opening into said inhalation chamber, an inner annular flexible diaphragm connected between said inner tubular extension of said housing and said exhalation valve forming an inner flexi ble ring shaped closure for said closed chamber, and

an outer concentric ring shaped flexible diaphragm connectedbetween. saidhousing and said exhalation valve a in forming an outer ring shaped flexible closure for said closed chamber.

2. Apparatus as claimed in claim 1 in which both of said ring shaped diaphragms are U-shaped in cross section, formed with the eifective pressure area of the outer ring shaped diaphragm open to ambient air through said exhalation port equal the opposing pressure on the outer ring shaped diaphragm in the inhalation chamber, and the effective pressure area on the inner ring shaped diaphragm within said closed chamber equals the opposing effective pressure area on the inner ring shaped diaphragm in the inhalation chamber.

3. A compensated inhalation and exhalation valve assembly for pressure breathing in a high altitude mask, comprising; a housing, said housing having inhalation and exhalation chambers and a port connecting the exhalation chamber with the ambient air, valve means in said housing separating said chambers, said valve means including an exhalation valve for opening and closing said port, biasing means connected to said exhalation valve and said housing for closing said exhalation valve, said exhalation valve having opposed surfaces, one surface in each chamber, and including a rigid tubular support portion and an inner ring shaped diaphragm and an annular concentric outer ring shaped diaphragm, the inner periphery of the inner ring shaped diaphragm and the outer periphery of the outer ring shaped diaphragm being secured to said housing to form a closed pressure chamber, within said inhalation chamber, said housing having a restricted communication port between said closed pressure chamber and said inhalation chamber for restrictively bleeding inhalation pressure between the closed pressure chamber and the inhalation chamber, an inhalation valve between said exhalation chamber and said inhalation chamber for admitting gas from said inhalation chamber into said exhalation chamber, said ring shaped flexible diaphragms both being. semicircular in cross section in planes perpendicular to the planes of the rings and transverse to the periphery of the tubular portion of the exhalation valve with the inner periphery of the outer ring shaped diaphragm and the outer periphery of the inner ring shaped diaphragm connected in sealed relation to said rigid tubular support the efiective area of said outer ring shaped diaphragm and the effective area of the surface of exhalation valve in the inhalation chamber being equal to the effective area of the exhalation and said exhalation valve is flexibly supported between the exhalation chamber and the inhalation chamber by the said inner and outer ring shaped diaphragms intermediate the respective inner periphery of the outer ring diaphragm and the outer periphery of the imter ring diaphragm.

valve in the exhalation chamber whereby the exhalation pressure necessary to open said exhalation valve against the forces of said biasing means is equal to the pressure entering the valve assembly plus a pressure increment sufficient to overcome said biasing means, said inner ring shaped diaphragm having an efiective pressure area in said pressure chamber equal to the effective pressure area on said inner ring diaphragm in said inhalation chamber.

4. Apparatus as claimed in claim 3 in which the inhalation valve is wholly supported by the exhalation valve 5. Apparatus as claimed in claim 4 in which said biasing means comprises; a light coil compression spring having one end engaging said exhalation valve and its opposite end engaging said housing with the inner periphery of the inner ring shaped diaphragm surrounding said spring in spaced relation thereto intermediate its ends.

6. Apparatus as claimed in claim 5 in which said housing has a tubular concentric extension projecting inwardly toward said inhalation chamber forming an annular inner Wall of said pressure chamber and said re stricted pressure relief passage is formed in said annular inner Wall establishing restricted communication between said inhalation chamber and said pressure chamber, and the inner periphery of said inner ring shaped diaphragm is fixed to the projecting end portion of said tubular extension.

7. Apparatus as claimed in claim 6 in which said exhalation valve is formed With a tubular extension having a communicating inhalation passage therethrough from the inhalation chamber into the exhalation chamber having an annular concentric inhalation valve seat having a diameter equal to the apex diameter of the inner U-shaped in cross section ring diaphragm and said inhalation valve comprises a flexible resilient diaphragm carried by said tubular extension of said exhalation valve resiliently seated on said inhalation valve seat closing said inhalation passage and opening into said exhalation chamber upon a relative increase in pressure in said inhalation chamber over the pressure in said exhalation chamber.

8. Apparatus as claimed in claim 7 in which said housing is formed with an annular concentric exhalation valve seat having a diameter equal to the apex diameter of said outer U-shaped in cross section flexible ring shaped diaphragm and said exhalation Valve is formed with an annular flat valve seat engaging surface disposed in a plane perpendicular to the axis of the tubular extension of the exhalation valve.

9. Apparatus as claimed in claim 8 in which said inner an outer ring shaped flexible diaphragms are formed integral of thin flexible rubber-like material to constitute a dual flexible double U-shaped in cross section diaphragm for closing said pressure chamber having an intermediate annular concentric recess portion, and said rigid tubular support portion of said exhalation valve projects toward said pressure chamber and is seated in said intermediate annular concentric recessed portion of the dual diaphragm.

No references cited.

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