Title:
Aviation mask
United States Patent 2398076


Abstract:
My invention relates to aviation masks particularly adapted for use in high altitudes in conjunction with oxygen supply mechanism of the demand type with the passages arranged and formed so that the exhaling valve mechanism $ will be protected from freezing, and restriction of the inhaled and...



Inventors:
Bulbullan, Arthur H.
Application Number:
US43979642A
Publication Date:
04/09/1946
Filing Date:
04/20/1942
Assignee:
Bulbullan, Arthur H.
Primary Class:
Other Classes:
128/205.25, 381/367
International Classes:
A62B18/02
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Description:

My invention relates to aviation masks particularly adapted for use in high altitudes in conjunction with oxygen supply mechanism of the demand type with the passages arranged and formed so that the exhaling valve mechanism $ will be protected from freezing, and restriction of the inhaled and exhaled gases will be at all times certainly and effectively prevented.

Mask structures of the type herein defined and claimed are primarily designed to be employed in military aviation where fighter planes are carried to very great heights. The heights to which such planes are capable of being driven have been rapidly increased during the last year or two, because it is known that the fighter plane which has the highest ceiling or has capacity for ascent to the greatest height has a very great advantage over planes that cannot reach that height, since the higher flying plane can reach an altitude above that? of the lower flying plane from which higher altitude attack is more likely to be successful. At these high altitudes it is, of course, necessary that oxygen, in sufficient concentration to maintain life, be delivered, in such a way as to maintain a suitable oxygen pressure in the alveolar regions of the lungs, must be continuously and certainly supplied.

Serious difficulties have been encountered in reference to such mask structures. One of these which has been found increasingly hard to overcome as higher elevations and a greater degree of cold are encountered, is in taking care of the moisture thrown from the lungs during expiration so as to prevent formation of ice on or about the exhaling valve, which might render it inoperative, or forming ice in the air passages, which might so restrict them. as to make satisfactory breathing impossible. Another difficulty has to do with sealing the mask upon the face so as to cover exposed portions below the eyes and protect such exposed portions from the intense cold of these high altitudes which is present in all seasons.

A further difficulty has been encountered in the fact that when the mask body is formed of semirigid material such as vulcanized rubber, it has heretofore been regarded essential or necessary to cover the body of the mask with a rigid saddle structure to help hold the mask in position, particularly in those instances in military aviation when quick maneuvers are essential as in the pull out in dive bombing, short turns and the like.

For the elimination of freezing, I have discovered that it is desirable to so position the exhalation passages and the exhaling valve that there is a short travel of gases of exhalation from the breathing chamber past the exhalation valve and, to outside atmosphere in passages of relatively large cross-sectional area. This short passage is kept sufficiently warm by the exhaled gases so that first, exhalations will go to atmosphere so quickly the amount of condensation will be small, and, second, it will never become cold enough to cause much condensation or to freeze any water which does condense. I have also discovered that by providing the mask body with a strong top wall forming the outer side of the breathing chamber in the mask body and by arranging a series of tubes and chambers with thick wall portions thereover in conjunction with a broad and thick flat-faced plateau extending about all the contact margins of the mask structure, the use of a rigid saddle structure and the difficulties both in making it fit properly and in having a mask which can be worn comfortably with such a rigid saddle structure can be avoided.

I have also discovered that a solution of the problem of comfortably sealing the mask upon the face may be found in providing a mask structure wherein the marginal contacting portions surrounding the body of the mask are made to enclose the nose, cheeks,,and chin of the wearer, that is substantially the entire face of the wearer below the eyes, and where these marginal portions are shaped as a raised plateau to provide a relatively large area of contact upon the facial parts of the wearer.

It is a principal object of my invention therefore to construct a mask wherein the exhaling valve will be located in respect to the breathing chamber in front of or below the mouth of the wearer and the passage or passages leading therefrom to outside atmosphere will be relatively large in cross-section and short in extent.

It is a further object of my invention to provide a relatively large valve chamber into which the exhalation valve is adapted to open centrally of the lower part of the breathing chamber of the mask, and to lead from the valve chamber a pair of short passages of large cross-sectional area diverging laterally and overlying passages coming from the oxygen or oxygen-air supply, which latter may be delivered from what is known as a demand type valve.

It is a further object of my invention to have the inlet passageway leading from the oxygen or oxygen-air supply, whether in continuous flow or more particularly of the demand type, centrally positioned at the bottom of the mask, and thereafter to divide the inlet passageway into two laterally disposed passageways underlying the exhalation passageways and surrounding the exhalation chamber.

It is a further object of my invention to provide a mask body having a broad raised plateaulike portion projected inwardly into the breathing chamber, which shall engage the face at the sides of the cheeks and under the chin with a broad contact surface, whereby the breathing chamber is effectively sealed throughout and all portions of the face and chin below the eyes and which would be below the cap and goggles of the aviator are protected against outside cold.

It is a further object of my invention to provide a mask structure formed of semi-rigid material such as vulcanized rubber, wherein no rigid saddle members are employed but embodying hooks or strips secured to the sides of the mask structure, in conjunction with a system of straps going about the head of the aviator above the 1 eyes, about the back part of the neck of the aviator, and over the top of the aviator's head, said system of straps, when connected with the aforesaid hook portions in conjunction with the face-contacting marginal plateau-like portions of the mask and the tube and chamber walls at the top of the mask body, operating to hold the mask on the face of the wearer no matter what stresses must be resisted such as those encountered in the pull-out of dive bombing operations and other airplane maneuvers.

The full objects and advantages of my invention will appear in connection with the detailed description thereof hereafter given in the specification, and the novel features of my invention by which the above noted advantageous results are produced will be particularly pointed out in the claims.

In the drawings illustrating an application of my invention in one form: Fig. 1 is a side elevation view of the mask structure as the same is worn.

Fig. la is a purely diagrammatic showing of oxygen supply means.

Fig. 2 is a full front top plan view of the mask structure.

Fig. 3 is a full bottom plan view of the mask structure showing the interior of the breathing chamber.

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2, viewed in the direction of the arrows.

Fig. 5 is a sectional longitudinal view of the mask structure, taken on line 5-5 of Fig. 2, viewed in the direction of the arrows.

Fig. 6 is a sectional plan view of the mask structure taken on line 6-6 of Fig. 5.

As shown in the drawings my mask structure comprises a body portion 10. This body portion has a nose-receiving part II and two cheekoverlying portions 12 and 13, which come together to extend under the chin of the wearer, as best indicated at 14 in Figs. 1, 3 and 4. The side walls of the nose engaging portion are normally held inwardly to grip the side walls of the nose by means of a metallic U-shaped spring member 15 embedded in the material of the mask body as indicated at 16 in Figs. 1, 5 and 6.

The marginal portion of the mask structure is formed with a broad face-engaging raised plateau indicated at 17 over the nose, at 18 over the cheeks, and at 19 under the chin, as best shown in Figs. 4 and 5. The mask body and the parts thereof excepting the exhaling valve, is and are formed of a semi-rigid material such as vulcanized rubber. The contacting portions 17, 18 and 19 are somewhat thickened as shown at 20 and 21 of Fig. 4 and at 22 of Fig. 5. This is in effect a face-engaging band or plateau which is raised inwardly from the body of the mask as indicated at 23 in Figs. 4 and 5. The mask body 10 has a depth from the face contacting plateau 17, 18 and 19 to a front wall 24 of the mask such that when worn there is an ample breathing chamber 25, Figs. 4 and 5, which, except for the passageways hereinafter described, is sealed from the outside atmosphere. The nose and mouth extend into the chamber 25 and, because of the ample space of said chamber, breathing is carried on with a marked degree of ease and comfort.

Overlying the front wall 24 of the mask structure is a Y-shaped extension 26, best shown in Figures 2 and 5, which provides an exhaling valve chamber 27 and two short diverging outlet 0 tubes 28 and 29, enclosing discharge passageways 30 and 31, as clearly shown in Figs. 3 and 6.

The wall 24 at the front of breathing chamber 25 is provided with a circular opening 32. Receiving the edges of the opening 32 is a groove 33 between the spaced flanges 34 and 35 of an exhaling valve member 36. This has an outer disc 37, Fig. 3, provided with a plurality of openings 38 held upon the disc 37 by a fastening device 39. Attached to the disc 37 at its center is a flap valve 40 adapted to engage an annular valve seat 41, Fig. 5. The flap valve 40 is within the valve chamber 27 which is, as clearly indicated in Figs. 5 and 6, of generous size relative to the exhaust area through the apertures 38 in plate 37. The openings of channels 30, 31, and the tubes 28, 29 are also of relatively large cross-sectional area.

It follows that as the wearer of the mask exhales the exhalation gases passing from the exhalation valve have opportunity to expand and flow freely and with ease through the large crosssectional area of the discharge openings over the short distances from the valve 37 to the outside air, which results in rapid release of the exhaled gases before they have time to cool. It also results in" so small a degree of cooling before the gases have reached the outside air that frost normally does not tend to form within the chamber 27,in quantities sufficient to injuriously restrict the valve chamber and passageways 30 and 31.

Furthermore, all the walls of chamber 37 and passageways 30 and 31 slope sharply downwardly so that if any moisture were to accumulate on these walls it would readily pass out with the ,1, warm exhalation gases and drip away from the edges of the passageways 30 and 31.

The relatively large area of the valve chamber 27 and passages 30 and 31 and their short extent and sharp downward slope without kinks or bends, are all of great importance in enabling the mask to be worn in the extremely low temperatures of altitudes of from 35,000 to 40,000 feet without the formation of ice upon or about the exhalation valve or in any substantial degree upon the walls of these passages. The exhalation gases are warm and between successive exhalations a considerable body of these warm gases is retained in the chamber 37 and the passages 30'and 31, so, even though the outer walls of the chamber and passages are exposed to the intense cold, this considerable body of warm exhalation gases within the chamber and passages does not have time to lose its heat sufficiently to form ice before a new body, of freshly warmed exhalation gases is introduced by a succeeding exhalation.

For the demand type oxygen supply, and indeed for any form of oxygen supply, it is advantageous to have the oxygen and rebreathed gases, with or without addition of air, introduced through a central passageway with a single tube leading to the rebeathing bag and the breathing responsive valve mechanism of a demand type oxygen supply or if desired to a continuously flowing oxygen supply means. In the mask of my invention a central tube 42 depends from the bottom part of the mask and is connected by means of a suitable flexible tubing 43, Fig. 1, with a suitable form of oxygen supply (diagrammatically shown).

The passageway 44 within the tubular extension 42, as clearly shown in Fig. 6, has two branch passages 45 and 46 extending through circularly disposed branch tubes 47 and 48. The passages 45 and 46 within the tubes 47 and 48 connect with the rebreathing chamber 13 through elongated openings 49, 50, as clearly shown in Pigs. 3, 4 and 6. These openings 49, 50 enter the breathing chamber toward the top and the tubes 47, 48 extend under the exhalation outlet tubes 28 and 29 and upon the body walls 12 and U3 of the breathing chamber, to all of which they are integrally attached. It follows that the inhalation gases will travel under the tubes 28 and 29 and along the side or cheek body portions 12 and 13 of the mask and in this way the inhalation gases may be in some degree pre-heated.. Also, the openings 49 and 50 admitting the inhalation gases to the breathing chamber are positioned at either side of the nostrils and of course, all parts are well out of contact with the alae nasi.

A circular extension 51 at the upper part of the mask structure provides a chamber 52, Fig. 5, adapted to receive a radio microphone and hold it protected in convenient position to be used in speaking. A circular opening 53 exposes the microphone to the breathing chamber. It will be noted, as shown in Figs. 3 and 5, that the front wall 24 through which the openings 32 and 53 lead to the exhaling chamber 27 and microphone chamber 52, respectively, is straight and extends in a single plane. This straight wall positions the openings to valve chamber and microphone chamber relative to the openings 49 and 50 from the inhalation tube 44 and its branches 46 and 47 in a manner to bring all of said openings most favorably positioned relative to the mouth and nose of the wearer. It also materially assists in providing the large exhalation chamber 27 and its short large downwardly extended tubes 28 and 29, which very greatly facilitates exhalation in breathing and also prevents freezing entirely, or permits freezing only at the outlets 30 and 31 of said branch tubes where the ice can be readily crushed and removed by the fingers.

This straight front wall in conjunction with the members forming the microphone chamber, the exhalation passageways and the inhalation passageways, provides an unusually strongly reinforced arrangement to support the mask in position on the face of the wearer and to resist external pressure strains such as are incurred during dive-bombing and the like.

No rigid saddle structure is employed with this mask since the arrangement of tubes and chambers and the thickened top wall 49 when constructed of semi-rigid material, such as vulcanized rubber, are strong enough to resist any tendency toward collapse. For holding the mask 6 body upon the face a hook structure 54 has its base 55 secured by suitable rivets 56 to the cheek portions 12 and 13 of the mask. A hook 57 fast on each of the hook members 54 is adapted to receive a metallic loop 58 through which ex- 7 tends a strap 59. The strap 59 is turned at the loops 58 on each side of the face as indicated at-' 60, one portion 61 going around the back of the neck and another portion 62.going over the top of the head. To the portion 62 a second strap I 63 is secured which goes around the head at the forehead and back of the head as shown in Fig. 1.

The entire arrangement secures the mask firmly upon the face of the aviator so as successfully to r resist any pressure forces encountered tending to strip the mask from the face.

The advantages of my invention will appear from the description which has been given in the Sspecification. A fuhdamental and principal advantage comes from the fact that the exhalation valve chamber and double passages therefrom are large in cross-sectional area permitting both quick passage of exhalation gases to outside atmosphere and retention of a considerable volume of such gases in the chamber and passages between exhalations, which volume being warm is not sufficiently cooled before a following exhalation so that condensation can freeze, either on the exhalating valve or on the inner walls of the discharge passageways.

It is a further advantage of my invention that the exhalation valve is located at the lower part of the breathing chamber of the mask in front of the mouth of the wearer as the mask is worn which will bring it below but in the vertical plane of the nostrils and substantially in front of the mouth, thus insuring short and easy travel of exhalation gases and putting these gases through the valve and into the valve chamber and outlet passages at.substantially their warmest temperature. Another marked advantage of my invention resides in the fact that the gases of inhalation come through a single central tube connection with relatively long passages under the exhalation gas outlets and along side walls of the breathing chamber, whereby the inhalation gases will be preliminarily warmed before entering the breathing chamber.

A further advantage of the arrangement of the inhalation passages and particularly their entrance into the breathing chamber is that this is immediately adjacent and at the sides of both nostrils so that breathing through the nose is thereby greatly facilitated. The circuit from inlet to outlet in the breathing chamber is short, the openings are generous in size, and the result is a facility and comfort in breathing comparable with that in the open air.

A further important advantage of my invention resides in the thickened face engaging plateau at the margins of the mask. This arrangement has been worked out to conform to the bony structure under the soft parts of the face. The mask margins are so positioned that they will be spread slightly on application to the average face, with the result that the plateau portions are held with a spring pressure against the parts of the fact contacted. This brings about effective sealing without discomfort in wearing the mask.

10 A further marked advantage of my invention resides in the fact that because of the form of construction of the mask body and the thickened contact plateau portions, the provision of valve chamber and microphone chamber along the cen5 ter of the mask and of thickened outlet tubes from the valve chamber, and the provision of central bottom inlet tube and thickened branch tubes united with the body of the mask, the mask can be safely worn under severe flying conditions '0 without the use of rigid saddle members and without danger of collapsing.

A further advantage of my invention related to that next above referred to, resides in the fact that the mask can be held on the face by a simple '5 hook structure attached to the sides thereof connected with bands (which may be elastic if desired) secured by means of loops to these hooks.

This makes possible ready and quick attachment of the mask to the face of the wearer and adds to the comfort of the wearer. This quick detachment may take place without removing the helmet and goggles worn by the aviator over the strap arrangement heretofore described, simply by slipping the loops I5 from the hooks. This may be of great importance in the event that the aviator is forced to bail out in high altitudes and at very low temperatures, in which case it would be necessary for him to divest himself of the mask connected with an oxygen supply carried by the airplane and use a parachute escape device with oxygen secured to the aviator's uniform. In such a situation it is highly advantageous to be able to take off the mask without disturbing the helmet and goggles.

I claim: 1. An oxygen mask for use at high altitudes, comprising a mask body having surrounding walls adapted to seal with marginal portions thereof against the checks, nose, and under the chin of the wearer, and having a straight front wall, all said walls enclosing a breathing chamber, an exhalation chamber of considerable size formed on the outside of the bottom portion of and connected with said front wall, an exhalation valve opening outwardly from said breathing chamber through said front wall into the exhalation chamber, and a pair of short, diverging outlet passages leading downwardly from the exhalation chamber and 'discharging to atmosphere at points outside the lower limits of the mask body.

2. An oxygen mask for use at high altitudes, comprising a mask body having surrounding walls adapted to seal with marginal portions thereof against the cheeks, nose, and under the chin of the wearer, and having a straight front wall extending centrally as worn up and down along said marginal portions, all said walls enclosing a breathing chamber, an exhaling valve on said front wall toward the bottom thereof, a valve chamber over said valve outside the front wall, a short outlet passage leading downwardly from said valve chamber to discharge to atmosphere, a microphone chamber extending outwardly from the upper part of said front wall, and inlet passages having the openings into the breathing chamber at the sides of the front wall, said front wall in combination with the parts connected therewith as related thereto greatly strengthening the mask body for attachment to the wearer and to resist pressure strains in use such as in dive bombing.

3. An oxygen mask for use at high altitudes, comprising a mask body adapted to seal against the cheeks, nose and under the chin of the wearer and to form a breathing chamber surrounding the mouth and nose, an inlet tube for admitting oxygen and gases from the rebreathing bag including a tube at the bottom center of the mask body and a pair of tubes branching from the central tube and each extending in an upward curve along the mask body to and opening into the upper part of the breathing chamber, and a valved exhaling outlet including a pair of outlet tubes overlying the inlet branch tubes and straddling the inlet central tube for discharging exhalation gases to atmosphere.

4. An oxygen mask for use at high altitudes, comprising a mask body adapted to seal against the cheeks, nose and under the chin of the wearer and to form a breathing chamber surS5 rounding the mouth and nose, an inlet tube for admitting oxygen and gases from the rebreathing bag including a tube at the bottom center of the mask body and a pair of tubes branching from the central tube and each extending in an upward curve along the mask body to and opening into the upper part of the breathing chamber, a valve chamber outside of the mask body and between said branch tubes, an outlet valve opening from the breathing chamber into said valve chamber, and a pair of short outlet tubes leading divergingly from the valve chamber so as to overlie the inlet branch tubes and straddle the inlet central tube for discharging exhalation gases to atmosphere.

5. An oxygen mask for use at high altitudes, comprising a mask body having means for contacting the nose, cheeks and under the chin of the wearer to form as worn a breathing chamber enclosing the mouth and nose of the wearer, said mask body having a straight front wall, extension members integrally united with said front wall forming a microphone chamber at the top and an exhalation chamber below the microphone chamber and diverging outlets therefrom and forming also inhalation tubes underlying said exhalation outlet tubes, whereby the exhaling valve, exhaling chamber, inhalation valves, opening to inhalation tubes, and microphone chamber are compactly and symmetrically positioned relative to the mouth and nose of the wearer in the rebreathing chamber when the mask is worn, and the mask body is thereby greatly strengthened for attachment to the wearer and to resist pressure strains in use such as dive-bombing.

6. An oxygen mask for use at high altitudes, comprising a body having a substantially straight front wall, a nose-receiving portion at the upper end thereof, a microphone chamber over and opening through the upper part bf said wall, an exhalation valve opening through the lower part of said wall, an extension forming a relatively large-sized exhalation chamber outside of said exhalation valve, and a pair of short diverging outlet passages of relatively large transverse area leading from the exhalation chamber to a point outside the lower limits of the mask body to atmosphere.

7. An oxygen mask for use at high altitudes, comprising a mask body formed with a broad inwardly projecting continuous marginal plateau of thickened material shaped and positioned to contact the nose, cheeks and under the chin of the wearer and seal the mask on the face of the wearer to form a breathing chamber enclosing the mouth and nose of the wearer, spaced elongated inlet tubes extending along the front of said mask body to near its upper part and integral therewith, and an outlet chamber and spaced outlet tubes on said mask body and overlying and attached to said inlet tubes, whereby the mask body in its entirety is rendered sufficiently firm and resistant to undergo the pressures and stresses of use in flying without rigid protecting saddle members.

ARTHUR H. BULBULIAN.