US 2578621 A
Description (OCR text may contain errors)
Dec. 11, 1951 w. P. YANT RESPIRAIOR MASK Filed Dec. 29, 1945 INVENTOR WITNESSES:
A", ATTORNEYS Patented Dec. 11, 1951 RESPIRATOR MASK William P. Yant, Murraysville, Pa., assignor to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Application December 29, 1945, Serial No. 637,822
This invention relates to respirator half masks which cover the nose and mouth of the wearer but not his eyes.
Such masks include a face-piece formed of impermeable flexible material and having a nosecovering portion at the top which is arched up over the nose and diverges downwardly. Because of the differences in noses and facial contours, as well as the pull of the head straps on the face-piece, the nose portion of the mask generally is the most difficult to fit against the face snugly enough to form a seal. To assure a better fit of the mask in general, it sometimes has been provided with a flange or lip extending inwardly and forwardly from the edge of the mask. This lip is quite flexible and is supposed to conform to the face to produce a seal, but it does not completely solve'the problem, especially around the nose.
It is ainong the objects of this invention to provide a respirator half mask in which the areas of the face-piece on opposite sides of the nose are prevented from spreading apart; in which those areas are drawn in tightly against the sides of the nose when the mask is applied to the face; and in which the face-engaging area of the facepiece is more yielding than heretofore.
In accordance with this invention, a flexible face-piece, having its nose-covering portion roughly conforming to the shape of a nose and diverging downwardly, is provided at the lower end of the nose-covering portion with a flexible cross member the opposite ends of which are connected to the face-piece near its face-receiving opening in a position to be engaged by the upper lip of the wearer. When the mask is worn the cross member prevents the cheeks and the head straps from holding the face-piece away from the sides of the nose, and the upper lip of the wearer presses forward on the cross member which thereby pulls the adjoining portions of the iacepiece toward each other to form a good seal at the sides of the nose. If the face-piece is provided around its face-receiving opening with a flexible sealing lip extending forward into the face-piece, the ends of the cross member can be joined to the free edges of this lip at opposite sides of the face-piece, or they can be joined to the face-piece in front of the sealing lip. Where such a lip is used, it is doubled upon itself with its outer edge joining the rear edge of the facepiece along a line in front of the bend in the lip. As a result, the bend in the lip, rather than the edge of the face-piece, contacts with the face. Preferably, the distance between the bend in the 2 Claims. (Cl. 128-146) lip and its outer edge is greater at the sides of the nose and below the chin than at other places to produce areas of greater flexibility.
The preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 is a front view of the mask; Fig. 2 is a rear view thereof; Fig. 3 is a side view; Fig. 4 is a horizontal section taken on the line IVIV of Fig. l; and Fig. 5 is a central vertical section showing the position of the mask when it is being worn on the face.
Referring to the drawings, the face-piece l of the mask is made of rubber or other suitable impervious flexible material and is in the gen eral shape of a triangle like a conventional half mask. The wide lower portion is designed to cover the mouth and chip of the wearer, while the upwardly tapered upper portion is formed for receiving his nose. The opposite sides of the lower portion of the face-piece are provided with inlet openings closed by conventional flexible inlet valves 2. Secured to the face-piece around each of these openings is a threaded cup 3 that has an opening communicating with the inlet opening. screwed into each of these cups so that all air that is inhaled must be drawn through the cartridges. As shown in Figs. 4 and 5, the bottom of the face-piece is provided with an outlet opening in which a ring 5 is mounted. This ring supports a flexible exhalation valve 3 and also a protective cage 8 for the valve. The mask can be held in place in the usual way by head straps (not shown) the end of which are hooked onto curved Wires 9 (Figs. 2 and 4) riveted to the face-piece behind the cartridge cups.
Preferably, there is integrally joined to the rear edge of the face-piece a flexible flange or lip ll of rubber which extends entirely around the face-receiving opening of the face-piece. The lip extends rearwardly and then is folded or bent inwardly and converges forward into the facepiece with the free edge of the lip spaced 2. considerable distance from the wall of the facepiece. The lower portion of the lip inside the face-piece is considerably wider than the rest of it and extends upwardly to provide a chinreceiving socket 12 that holds the mask in posi tion around the mouth. For the most part, the lip is thinner and more flexible than the wall of the face-piece, and its free marginal portion generally will conform to the contour of the face and help form a seal. The rear edge-ofthe facepieee does not engage the face. Instead, contact 'is made with the soft, yielding lipfat its fold.
A removable filter cartridge 4 is This improves the seal and makes the mask more comfortable to wear. It has been found that the greatest flexibility in the mask is required at the sides of the nose and below the chin. Therefore, the rearwardly extending section of the lip is increased in depth in those 10- cations to provide the desired flexibility. As shown in Fig. 3, this is done by making the edge of the face-piece on opposite sides of the nose and beneath the chin concave so that in those locations greater areas will have to be occupied by lip H. The wide areas of this sealing lip beside the nose will tend to be rolled inwardly against the nose when the mask is applied to the face. a
To avoid the possibility that the mask may not fit snugly enough around the noses of some people, due to the cheeks tending to push the facepiece away from the sides of the nose, or to the tendency of the head straps to spread the nose covering portion of the face-piece, provision is made for positively counteracting any such spreading action by tying the opposite sides of the nose-covering portion together. This is accomplished by'rneans of a thin, flexible cross member 13 which is located near the rear and at the lower end'of the nose-covering portion in a position where it will engage the upper lip of the wearer. Preferably, the opposite ends of this cross member are connected to the free edges of the sealing lip with which they most suitably are integral. When the mask is fitted on the face the flexible cross member not only keeps the nose-covering portion of the face-piece from spreading, but the cross member is pushed forward 3 by the upper lap of the wearer and therefore draws the opposed portions of flexible lip l! toward each other. This, in effect, clamps the face-- piece lip tightly against both sides of the nose and insures a seal. Yielding of the nose-engag ing portion of the lip for this purpose is facilitated by the wide areas of the lip on opposite sides of the nose.
The cross member 13, by preventing the opposite portions of lip II from spreading too far apart, allows the mask to be made of thinner material than otherwise would be possible. In other words, the cross member helps the mask to retain its shape even though it is very thin and flexible, which is desirable for snugger fitting.
According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent .5 its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.
1. A respirator half mask comprising a facepiece formed of resilient material and having a nose-covering portion conforming roughly to the shape of the nose, and a cross member at the rear of the face-piece extending across the lower end of said nose-covering portion for tying opposite sides of said portion together.
2. A respirator half mask comprising a facepiece formed of resilient material and having a nose-covering portion conforming roughly to the shape of the nose, and a flexible cross member inside the face-piece at the lower end of said nose-covering portion in a position to be engaged and pressed forward by the upper lip of the wearer, the opposite ends of said member being connected to the sides of said nose-covering portion to keep them from spreading apart.
WILLIAM P. YANT.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 2,320,770 Cover June 1, 1943 2,329,154 Bulbulian Sept. 7, l 43 2,391,677 Bulbulian Dec. 25, 1945 2,403,046 Bulbulian July 2, 1946 2,415,846 Randall Feb. 18, 1947