US2858828A - Respirator - Google Patents

Description

1958 J. N. MATHESON 8,

RESPIRATOR Filed May 18. 1954 INV ENT OR.

JzmerM/Mesan.

-m0mmr RESPIRATOR James N. Matheson, West Reading, Pa., assignor, by mesne assignments, to The Electric Storage Battery JCompany, Philadelphia, Pa., a corporation of New ersey Application May 18, 1954, Serial No. 430,488

9 Claims. (Cl. 128-141) This invention relates to a respirator, and more particularly to an airline respirator mask, although the features thereof are applicable to other types of respirators.

In commonly used designs of airline respirators, air from an external source is supplied through a bellows inlet tube to the bottom part of the mask. This has outstanding disadvantages in that the tube is brought very close to the wearers body causing interference and, more particularly, as a consequence of lowering of the wearers head the tube'is collapsed, therefore reducing or shutting off the air supply.

A still further disadvantage of common types of respirator facepieces or masks is that exhaled air is generally deflected sidewise or upwardly therein, therefore much of theair is blown against the face and up the nostrils of the wearer, causing objectionable breathing resistance and annoyance. Also a still further disadvantage of commonly used respirators is that the'exhalation valve is not always reliable for effecting a complete seal upon inhalation because oftentimes there are defects in the rubber diaphragm, such as small pin point projections, which prevent the possibility of an air-tight seal; that is, the single sealing ring formed adjacent the rim of the valve diaphragm is ineflective as a seal if at any point thereof 'the seal is broken because of the presence of the aforeor through the inlet breathing tube.

A still further object of my invention is to provide a reliable exhalation valve having a plurality of sealing rings to assure a perfect seal even in the event of sealimpairing imperfections in the valve.

Other objects and advantages of the present invention will become more apparent from a study of the following description taken with the accompanying drawing wherein:

Figure 1 is a front elevational view of the mask portion of an airline respirator embodying the principles of my invention;

Figure 2 is a vertical cross-sectional view taken along line lI-II of Figure 1;

Figure 3 is a somewhat enlarged elevational view, as viewed from the exterior, of the exhalation valve shown in Figures 1 and 2, wherein a portion of the valve diaphragm is shown broken away-to more clearly illustrate the sealing ridges or rings;

Figure 4 is a transverse, cross-sectional view taken along line IVIV of Figure 3; I

United States Patent "ice Figure 5 is an enlarged, fragmentary cross-sectional view of a modified form of the valveseat shown in Figures 3, and 4;

Figure 6 is an enlarged fragmentary cross-sectional view of a second modified form of valve seat and;

Figure 7 is a fragmentary cross-sectional view of a third modified form of valve seat.

Referring more particularly to the drawing, numeralv 1 denotes a respirator mask of molded rubber or similar elastic material having detachably secured thereto, by snap fasteners, straps 2 (shown broken away). Straps 2 are adapted to encircle the head of the wearer for holding the inturned mouth portion 1a of the mask in air-tight, sealing engagement about the nose, cheeks and chin of the wearer. Adjacent the nose portion are tapered accordion-like pleats 1b of the same thickness or reduced thickness as compared to that of the respirator mask 1 to allow the nose encircling portion to freely pivot forwardly ina readily yieldable manner, about the apex of said pleats as pivots or hinges, so as to conform to different shapes of noses of different wearers and so as to allow wearing of the mask either high or low on the nose.

Integrally formed on the front portion of the respirator mask is an inlet snout 3, also of rubber or the like, which extends downwardly at an angle away from the wearers face. A ring 4 of metal or plastic materialis slip-fitted in the end portion of the snout so that one end of a flexible breathing tube (not shown), such as one of accordion design, may be slip-fitted to the ring, like the end portion ofthe snout. The other end of the breathing tube is attached to any suitable source of air supply, such :as a compressed air tank or a chemical cartridge worn by the wearer which filters incoming air from the atmosphere. Thus the breathing tube is projected downwardly and outwardly away from the wearer to prevent the possibility of its being closed 01f as the result of lowering of the wearers head as in common designs in which the breathing tube emerges from the bottom portion of the respirator. Also, the tube does not interfere with the wearer. Moreover, in case of accidental pressing of the snout against the wearers face there are no hard metallic or plastic parts which would cause injury to the face of the wearer in view of the integrally molded design of the snout 3.

At the junction of snout 3 and mask 1 there is provided an integral, vertically downwardly extending bafile It for the purpose of deflecting downwardly, directly into the exhalation valve 5, air exhaled by the wearer and thus preventing such air from being deflected against the face or upwardly of the nostrils of the wearer which would cause increased breathing resistance and annoyance. Also it prevents exhaled air and moisture from entering the snout 3 and air inlet tube.

The exhalation valve comprises mainly a somewhat wheel-shaped, valve seat element 5, preferably of hard plastic material, having a central groove ,6 of reduced diameter, about its perimeter, which tightly fits, vin an air-tight manner, in a hole formed in the lower part of respirator mask 1. The outside portion of the wheellike, valve seat element 5 is dished, as shown more clearly in Figure 4, along the configuration of a spherical segment. A rubber diaphragm 7 of disc shape is securely anchored at the center thereof to element 5 by means of an integral projection 5a having an enlarged head. A small hole in the center of diaphragm 7 is stretched in diameter and slipped over the enlarged head portion of projection 5a.

An important feature of the exhalation valve is the provision of a plurality of annular ridges or seats 8 against which the outer peripheral portion of diaphragm 7 will come into sealing engagement. As will be more apparent from Figure 5, there are three concentric,.sealing rings or annular seats provided by ridges 8 so that if by virtue of some imperfection, such as a small pro- Tjection .on the inner surface of diaphragm 7,":the seal :should she 'broken along any rone of :the rings, the other two rings will serve to insure sealing engagement along a closed circular ;path. ThedishedTOut shape of the seat .element 5 causes an initial yieldable engage- .ment of the peripheral portion :of rubber .diaphragm 7 against the respective sealing rings. The grooves be iweenthe rings .provide an outlet for :moisture such as slhat'which is breathed out, to prevent collection on a large area of :the sealing surface which would make suchfa tight scales-.torequire abnormal exhalation pres- ;sm'eitmbreaktheseal. .A maximum-sealing area for the mespective :sealingrings T8 is providedlif the surfaces of the ledgesare substantially flatasshown in Figure 5. .However, .insome.instances.itis desirable to keep the ssealing area 'IOf :the respective ridges at a minimum to lower :breathing resistance and .to facilitate breaking of the seal :byexhalation. Such design is shown in Figure i6 wherein therespectivesealing rings 9 come to a point to 'formatline contact with diaphragm 7. Figure ,71shows a still further modification in which ,thezsealing rings.10 are rounded so as to provide a sealingsurface which is intermediate that shown in Figures 5 .and 6.

f course, other numbers of rings than the three tzshown'may be used instead, such as .1, 2, 4, 5, etc. Also, desired, the outer surface of element need not be dished. While .it would be possible to provide sealing :ringsmn the diaphragm rather than on the valve seat this would not be as advantageous asthe construction shown .since it .is far more expensive to mold a rubber dizaphragm with such rings thanit would be to mold the element 5, the latter being preferably of plastic material, .which is more inexpensively molded and requires a :shorter time'than for the molding operation of rubber.

Thusit will be seen that I .have provided an eflicient respirator mask of integrally molded design, including a cdownwardlyand outwardly projecting snout which pre- =vents [accidental shuttingofl .of the air supply as a con- .-sequence of lowering .of the wearers head; also I have provided, .in ,the integrally molded respirator, a baffie which-prevents undesirable blowingof exhaled air against 'the .face or up the nostrils of the wearer or directly through the inlet tube; furthermore, I have provided a hi ghly reliable exhalation valve structure including a ;plurality ,of concentric sealingrings or seats ,to insure a perfect sealalong at least one or more rings in the event '-0f imperfections in the valve parts which .might cause ,breakage of .the seal alongany of the rings; furthermore, .1 :have provided acne-piece respirator mask whichis of ,,such construction as to minimize injury to the face of .-the-.wearerin case the. snout is accidentally pushed against the face, such as by a welding helmet or the like; furthermore, while various novel features are shown in .connection with an airline respirator it will be observed ,that they are useful for other types of respirators and .masks .for .similar purposes.

While Ihave illustrated and .describedseveral embodiments of my invention, it will be understood that these ..are.by.way of illustrationvonly, and that various changes and modifications, may bemade withinthe contemplation ..of my invention and within the-scope of the following ..claims.

' 'l-claim:

.1. A respirator mask ,of molded elastic material of L'substantially cup shape with a substantially pear shaped mouth portion adapted to form an air tightfit about the v.nose, cheeks and chin of the wearer, and .having an in- .tegralsnoutportion in the form of a tube extending an- ,gularly downwardly and outwardly from the plane of thelfront, central portion of the mask, beginningfrom the vicinity of the nose of the wearer, a sleeve at the outer endof said tube onto which auairflinlettubeisattachable, and an exhalation valve mounted on the bottom, chin surrounding portion of said mask including a disc shaped, flexible diaphragm rigidly mounted centrally thereof to a valve seat on the outside surface of said mask, a downwardly trextending integrally molded baffle disposed at the top of the junction of said snout and mask and encircling the upper half portion of the integrally attached end of said tube anddisposed forwardly of the nose of the wearerin a position so as to deflect exhaled air away from said inlet snout and directly against the chin encircling portion of the respirator into said exhalation valve to eflect unseating of the valve and exhaust of said air.

2. A respiratoras recited in claim 1 wherein the nose encircling portion of said respirator is provided with bellows-like pleats tapering to hinge points located on opposite sides of the n'osesto :permit the nose engaging portion to be forwardly yieldable.

3. A respirator *mask .of molded :flexible material .aud of substantially cup shape having a :substantially pear shaped mouth portion :adapted to form an air-tight fit about the nose, cheeksandtchin of .the wearer andhaving an integrally-molded tubular inlet .snout projecting forwardly and downwardly from thetfront central portion of the :respirator Lm'ask beginning adjacent the nose ,of

"the wearer, .aan exhalation valve including .a valve seat secured to the bottom of .said mask adjacent the chin of the wearer and *baffle means at the junction of said snoutand mask-for deflecting exhaled air in the direction towardsaid exhalation valve, said valve seat comprising a wheel-like element, between the spokes of which ,outlet passages are provided and having a central hub withan outwardly extending projection, a flat, disc shaped rubber diaphragm having a central hole through which saidprojection extends to'rigidly secure the center of said diaphragm to said .hub, said valve including a 'plurality-ofconcentric rings adapted to form seats for sealing engagement with=the outer peripheral portion of .said valve, whereby upon exhalation, said diaphragm will be unseated from said rings.

-4. .Arespiratoras-recited in claim 3 wherein the outer face portion of said seating element is dished out whereby the .central anchoriug point ;is-d isposed inwardly .with respect to'said sealingridgesto assureinitial contact of the diaphragm with ,said :ridges.

'5. -A respirator as recited in claim 3 wherein .said sealing'ridges terminate 'in flat sealing surfaces for contacting said diaphragm.

6. A respirator .as recited in ,claim 3 wherein said ridges are tapered in cross-section to substantially a point, ,to provide line-sealing engagement with said 7. A respirator as recited in claim 3 wherein said sealing ridges are rounded .in cross-section, their crests providing sealing-engagement with saiddiaphragm along concentric circles.

8. A respirator .mask of molded elastic material of substantially cup .shape with .a substantially pear shaped mouth portionadapted to form anair-ttight fit about the nose, cheeks and .chin of .the wearer and having an integral tubular portion for passage of air into the mask and having .an outlet opening at the bottom thereof for allowing exhaledair to pass .to the exterior of the mask, a baflle inside said mask integrally formed coextens'ively with said .fronLfaceportion .at .the end of said tubular portion and inclined with respect to the axis of said tubular .portionfor-deflecting air breathed in through said tubular portion directly towards said outlet opening.

9. .A respirator mask of molded flexible material having a marginal portion 'for forming an air-tight 'fit with the face of the wearer, and having an exhalation valve comprising a valve seat having 'a dished central "hub portion with radially outwardly extending spokes through which outlet openings areprovided, and a rim at the extremities of said spokes in which are formed a plurality of concentric rings surrounding said openings, the outer surface of said spokes and rim being dished, and a flat, disc shaped, thin rubber diaphragm rigidly secured at its center to said hub exteriorly of said mask and normally seating against said rings because of said dished shape but being unseated therefrom as the result of exhalation of the wearer.

1,352,818 Lamb et a1 Sept. 14, 1920 6 Greenwald June 25, 1929 Bullard Aug. 18, 1936 Leguillon Apr; 15, 1941 Dank Feb. 27, 1945 Yant Aug. 14, 1945 Akerman Apr. 19, 1949 Glidden July 20, 1954 Matheson et a1 Apr. 26, 1955 Russell Jan. 7, 1958 FOREIGN PATENTS France Oct. 20, 1931 Great Britain May 16, 1951

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