US3067741A - Face masks for use in the administration of oxygen or other gases - Google Patents

Description

Dec. 11, 1962 F. G. CROASDAILE 3, FACE MASKS FOR USE IN THE ADMINISTRATION OF OXYGEN OR OTHER GASES Filed Nov. 27, 1959 2 Sheets-Sheet 1 INVENToR ATTORNE S Dec. 11, 1962 F. G. CROASDAILE 3,067,741

FACE MASKS FOR USE IN THE ADMINISTRATION OF OXYGEN OR OTHER GASES Filed Nov. 27, 1959 2 Sheets-Sheet 2 INVENTOR 42 H Fkbfi'kKK Gamer CRMSOAILE ATTORNEYS United States Patent ()filice 3,067,741 Patented Dec. 11, 1962 3,067,741 FACE MASKS FOR USE IN THE ADMINISTRATION OF OXYGEN OR OTHER GASES Frederick George Croasdaile, London, England, assignor to Oxygenaire (London) Limited, London, England Filed Nov. 27, 1959, Ser. No. 855,727 Claims priority, application Great Britain Aug. 18, 1959 1 Claim. (Cl. 128205) This invention relates to face masks for use in the administration of oxygen and other gases, comprising a project from its open edge on the side in which the aperbag of flexible substantially gas-proof material having an a open edge into which the nose and chin of a person may be inserted.

- One object of the invention is to provide a simple form of face mask capable of being produced at a cost' low enough to "justify its being discarded after being used only once, thus avoiding the need for sterilisation after use.

Another object of the invention is to provide a face mask which is maintained in substantially gas-tight engagement with the users face, by means dependent on the continued flow of gas into the mask, so that such gastight engagement is lost if the gas supply fails.

The invention consists in the provision of means defining a tubular enclosure extending around at least a part of the open edge of the bag, the gas to be administered being led into the said enclosure and passing therefrom into the bag and the inlet to and outlet from the enclosure being of such relative dimensions that the enclosure is infiated by the gas supplied to the mask.

In the accompanying drawings:

FIGURE '1 is a side view of one form of face mask according to the invention;

FIGURE 2 is a perspective view showing the mask of FIGURE 1 in position on a users face;

FIGURE 3 is a section on the line III-III of FIG- 7 URE 1;

FIGURE 4 is a side view, similar to FIGURE 1, of another form of face mask according to the invention;

FIGURE 5 is a section on the line V-V of FIG- URE 4;

FIGURE 6 is a partial view of the mask shown in FIGURE 4, as viewed from the opposite side;

FIGURE 7 is a perspective view showing the mask of FIGURES 4 to 6 in position on a users face; and

FIGURE 8 is an explanatory detail view similar to part of FIGURE 5.

Referring to FIGURES 1 to 3 of the drawings, the mask comprises a bag 10 of thin plastic material such as polyvinyl chloride, open at one edge 11 and closed at its other edges. The material may be transparent and the drawing illustrates a mask made of transparent material. The bag 10 is conveniently made from plastic material extruded in tubular form and cut into suitable lengths, one end of each length having its corners rounded as at 12 and the two sides being heat-sealed together at that end. The other end of the piece is folded inwardly and heatsealed at its edge to the inner face of the bag wall, along the line 13, the line of sealing extending around the edge of a tab 14 projecting from the edge of the folded-in portion. There is thus formed a tubular enclosure '15 extending around the open edge of the bag 10, and a pocket 16 opening into the tubular enclosure.

A tubular inlet fitting 17 is heat-sealed to the side of the bag 10 within the area of the pocket 16 and is adapted to receive a flexible tube 18 (FIGURE 2) connecting the mask to a gas container or other source of supply of gas under pressure. In the tab 14 which forms the inner wall of the pocket 16 there is formed an aperture 19 connecting the said pocket to the interior of the bag, the said tures 22 are formed, and an elastic cord' 24 extends be tween the two-straps 23. J

The mask is fitted to the users face by insertingthe nose and chin into the open edge of the bag, the side of the latter to which the inlet fitting 17 is attached passing under the chin, and the elastic cord 24 is passed round the back of the users head to holdthe mask in position. Oxygen or other gas to be administered is fed into the mask through the tube 18 and, since'the restriction at the apertur'e '19 is greater than at'the inlet" fitting 17,'.the gas passing through the tubular enclosure 15 into the bag 10 inflates the said tubular enclosure. Such inflation causes the inner wall of the enclosure to be pressed against the users face to make a substantially gas-tight contact therewith. As the user breathes he inhales the oxygen supplied to the bag, and the exhaled gases in part escape through the apertures 22, the remainder, enriched by the increasing oxygen, being re-inhaled by the user. If the gas supply fails, the tubular enclosure 15 is de-inflated, and the mask tends to fall away from the face leaving the user free to breath atmospheric air.

The face mask shown in FIGURES 4 to 8 of the drawings comprises a bag 25 made of thin sheet plastic material such as polyvinyl chloride, the material being first cut to a suitable shape and then folded and joined where necessary by heat-sealing. The bag 25 is open at one edge 26 and tapers inwardly from that edge to a relatively narrow rounded end 27. A portion 28 of the sheet material is folded inwardly around the open edge of the bag, and an extension of the folded in portion is provided, comprising a relatively narrow membrane like portion 30 and a substantially circular portion 31. The folded-in portion 28 is heat-sealed to the inner surface of the bag at 32 to form a tubular enclosure 33 around the open edge of the bag, and the extension is also heat-sealed to one wall of the bag around its edge to provide, between itself and that wall of the bag, a capsule 34 connected to the tubular enclosure 33 by a passage 35. The tubular enclosure 33 does not extend completely round the edge 26 of the bag, but is interrupted at 36 where the said edge, when the mask is in use, lies over the bridge of the users nose.

A tubular inlet fitting 37, similar to that described with reference to FIGURES 1 to 3, is heat-sealed to the wall of the bag 25 so as to open into the capsule 34, and an aperture 38, substantially smaller in area than the smallest part of the bore of the inlet fitting at 39, leads from the passage 35 into the interior of the bag. A stiffening disc 41 is heat-sealed to the wall of the bag opposite to that to which the extension 30, 31 is secured, so as to lie within the area of the capsule 34, and a pair of segmental holes 42 are cut through the disc 41 and the part of the wall of the bag which it covers.

Apertures 43, corresponding to the apertures 22 shown in FIGURE 1, are formed in the same wall of the bag as the holes 42, and the mask is fitted with straps 44 and an elastic cord 45 for holding it in position on the users face, as already described.

In the face mask shown in FIGURES 4 to 7 the incoming gas not only inflates the tubular enclosure 33, but also inflates the capsule 34 and the passage 35. The inflation of the capsule 34 causes the substantially circular portion 31 of the extension, which forms the inner wall of the capsule, to press against the opposite wall of the bag, as shown in FIGURE 8, and cover the holes 42, with the result that these holes are closed. Thus; communication between the interior of the bag and the atmosphere is limited to that provided by the apertures 43 so long as the gas is being supplied. Failure of the gas supply, however, causes the capsule 34 to collapse, opening the holes 42 and allowing 'air to enter and leave the bag through them, so that the user is not distressed by restriction of air for breathing even if the edge of the mask remains in fairly air-tight contact with his face.

I claim:

A face mask comprising a bag of thin flexible substantially gas-proof sheet material having walls and an open end into which the nose and chin of the wearer may be inserted so that the'open end engages the wearers face, means for holding the bag in position on the wearers face, at least one relatively large aperture in one wall of said bag connecting the interior of the bag to the atmosphere, a gas inlet in the other wall of said bag, means for closing said aperture when gas is flowing into said inlet, said closing means comprising a thin, flexible, gas-proof membrane in said bag, said membrane being attached to said other wall and forming therewith a capsule, a tubular enclosure extending around at least a part of said open end of the bag, passage means connecting said capsule to said tubular enclosure, said gas inlet communicating with the inside of said capsule, an outlet opening in said capsule leading to the interior of the bag, said opening being of a smaller size than said gas inlet, whereby when gas is applied to said inlet the flow at the outlet opening will be restricted more than at the inlet so that said capsule will be inflated by the incoming gas closing the aperture in said bag to the atmosphere and said tubular enclosure will be inflated whereby gas-tight contact against the Wearers face will be effected.

References Cited in the file of this patent FOREIGN PATENTS

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