Respirator

Nov. 4, 1958

J. N. MATHESON

RESPIRATOR

Filed May 18. 1954

2,858,828

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United States Patent Office Patented Nov. 4, 1958

Figure 5 is an enlarged, fragmentary cross-sectional view of a modified form of the valve seat 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, numeral 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 la 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 lb 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 in a 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 wearer’s face. A ring 4 of metal or plastic material is 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 of the 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 off as the result of lowering of the wearer’s 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 wearer’s 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 baffle 1c 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, in 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 Sa 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 Sa.

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

2,858,828 RESPIRATOR _g

James N. Matheson, West Reading, Pa., assignor, by mesne assignments, to The Electric Storage Battery Company, Philadelphia, Pa., a corporation of New Jersey

Application May 18, 1954, Serial No. 430,488

Claims. (CI, 128—141)

This invention relates to a respirator, and more par- 15 ticularly 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 20 outstanding disadvantages in that the tube is brought very close to the wearer’s body causing interference and, more particularly, as a consequence of lowering of the wearer’s head the tube is collapsed, therefore reducing or shutting off the air supply. . ²⁵

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 the air is blown against the face and up the nostrils of the wearer, causing objectionable breathing resistance and ³⁰annoyance. 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 ineffective as a seal if at any point thereof the seal is broken because of the presence of the aforesaid defects.

An object of my invention is to provide a novel respirator which is devoid of the above named disadvantages and which has an integral air-inlet snout which keeps the breathing tube away from the face of the wearer, thus prevents the possibility of accidental closing off of the 45 air supply by lowering of the wearer’s head.

A further object of my invention is to provide an integral baffle plate in a respirator mask to deflect exhaled air directly downwardly to the exhalation valve, to prevent blowing of such air against the face of the wearer 50 or 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. ^ilJ

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 por- ^ουtion of an airline respirator embodying the principles of my invention;

Figure 2 is a vertical cross-sectional view taken along line Π—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; . „θ

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

2,858,828 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 projection -on the inner surface of diaphragm 7, the •seal should :be broken along any one of the rings, the other two rings will serve to insure sealing engagement along a-closed circular path. The . dishedrout shape of the seat element .5 causes an initial yieldable engagement of .the ^peripheral portion of rubber diaphragm 7 against the respective .sealing rings. The grooves between the rings .provide an outlet for .moisture such as that which is breathed out, to prevent collection on a large area of the sealing surface which would make such a tight seal.as to require abnormal exhalation pressure:to;break.the.seal. .A maximum sealing area for the ’respective /sealing .rings :8 is provided.if the surfaces of the ledges.: are substantially flat as shown in Figure 5.

However, in some instances it is desirable to keep the ./sealing area of .the respective ridges at a minimum to lower .breathing resistance and to Facilitate breaking of -the seal:by exhalation. Such design is shown in Figure 16 wherein the. respective sealing rings 9 come to a point to form a line contact with diaphragm 7.

Figure 7 . shows a still further modification in which .the:sealing rings 10 are rounded so as to provide a seal-ing surface which is intermediate that shown in Figures 5 .and 6.

Of course, other numbers of rings than the three shown may be used instead, such as 1, 2, 4, 5, etc. Also, if .desired, the outer surface of element 5 need not be /dished. While it would be possible to provide sealing /rings,on the diaphragm rather than on the valve seat this would not be as advantageous as the construction shown .since it is far more expensive to mold a rubber diaphragm with such rings than. it 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.

Thus it will be seen that I have provided an efficient .respirator mask of integrally molded design, including a -downwardly and outwardly projecting snout which prevents accidental shutting off of the air supply as a consequence of lowering of the wearer’s head; also I have /provided, in the integrally molded respirator, a baffle which prevents undesirable blowing of exhaled air against ’the face or up the nostrils of the wearer or directly through the inlet tube; furthermore, I have provided a .highly reliable exhalation valve structure including a plurality of concentric sealing rings or seats to insure a ..perfect seal along at least one or more rings in the event of imperfections in the valve parts which might cause breakage of the seal along, any of the rings; furthermore, I’have provided a one-piece respirator mask which is of such construction as to minimize injury to the face of fhe wearer in 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 I have illustrated and .described, several embodiments of my invention, it will be understood that these .are.by way of illustration only, and that various changes .and modifications, may be made within the contemplation of my invention and within the scope of the following claims.