US 3736928 A
The invention is concerned with a hygienic face mask formed from a single sheet of air-filtering fibrous sheet material so folded as to provide a free space between outer and inner walls of the mask. Air flow openings are or may be provided at the rear end portion of the outer walls. The mask is held snugly against the nose and adjacent portion of the face of the wearer by means of a stiff but deformable clip member inserted in slits in the top of the mask.
Description (OCR text may contain errors)
United States Patent [191 Andersson et al.
1 1 June 5, 1973 154] COLLAPSIBLE FACE MASK 175] lnventorszErik Arne Andersson; Bror Axwl Erling Andersson, both of Stockholm,Sweden  Assignee: Nils O. W. Rundblad, Markaryd,
Sweden 221 Filed: Mar. 15, 1971  Appl.No.: 124,259
 US. Cl ..l28/146.2, 128/139  Int. Cl. ..A62b 23/02  Field of Search ..128/146.2, 146.6,
 References Cited UNITED STATES PATENTS 3,500,825 3/1970 Andersson ..128/146.2 X
FOREIGN PATENTS OR APPLICATIONS 62,257 3/1944 Denmark ..l28/146.2 4,789 12/1912 GreatBritain ..128/146.6
Primary ExaminerWilliam E. Kamm Assistant Examiner-G. F Dunne Attorney-Pierce, Sche'ffler & Parker 57 ABSTRACT The invention is concerned with a hygienic face mask formed from a single sheet of air-filtering fibrous sheet material so folded as to provide a free space between outer and inner walls of the mask. Air flow openings are or may be provided at the rear end portion of the outer walls. The mask is held snugly against the nose and adjacent portion of the face of the wearer by means of a stiff but deformable clip member inserted in slits in the top of the mask.
1 Claim, 4 Drawing Figures COLLAPSIBLE FACE MASK The present invention relates to face masks, and has as its object the provision of a collapsible hygienic face mask which is suitable for mass production, at a low price, but which is, nevertheless, effective and comfortable to use. Due to its low price, the mask may be disposed of'after it has been used.
The mask according to the invention is made of a foldable, air-filtering sheet of permeable fibrous material.
A suitable embodiment of the invention is shown by way of example in the accompanying drawing, in which FIG. 1 is a plan view of the mask with its two identical halves in superimposed position, that is, lying flat on each other;
FIG. 2 is a cross-section along line 22 in FIG. 1;
FIG. 3 is a diagrammatic perspective view of the mask when the halves of the mask are spread apart and the mask is cut along the line 22 in FIG. 1; and
FIG. 4 is a diagrammatic view of the mask when mounted on the face of a person.
The mask is made of a single piece ofa foldable, nonwoven, air-filtering fibrous sheet material which has been cut from a continuous web of such material, and which has been folded to a generally W-shaped crosssection as will be understood from FIG. 2.
The mask comprises two identical double-walled halves each of which has outer walls 1 and 2 respectively and inner walls 3 and 4 respectively. The forward edge 5 of the mask, which is also the junction of the forward edges of the outer walls 1, 2, is concavely curved, whereas the rear edge 6 of the mask is straight.
From the ends 7, 8 of the curved forward edge 5 to a middle portion located between two points 9 and 10, the outer and inner walls 1, 2 and 3, 4, respectively are united along lines 11 and 12. Between the points 10 and 11 the front edges of the inner walls are joined to-' gether by a straight fold 13 which is spaced from the uniting line 14 joining the edges of the outer walls between the points 9 and 10. Thus, a free space 15 roughly approaching in shape the segment of a sphere is formed between the outer and inner walls in the mouth region of the mask.
The rear ends of the inner and outer walls are joined by folds l6 and 17 respectively, and here an elastic attachment string 18 is passed between the walls to enable the mask to be attached to the head of a wearer.
The exhalation and inhalation air will pass through the two layers formed by the outer and inner walls as indicated by the arrows 19 in FIG. 3. However, in the example shown, part of the air will pass through the space 15 and the tunnel passage formed between the outer and inner walls 1, 3 and 2, 4 to air flow openings 20, 21 in the rear end portions of the outer walls as indicated by the arrows 22. These openings may be provided when it is desired to facilitate breathing.
A deformable metal strip 23 is secured at the upper end of the forward edge 5 and has its legs inserted into slits 24, 24 in the outer walls. When the mask is mounted on the face of a person and strip 23 is pressed tightly against the nose, the strip will retain its shape and will hold the mask tightly against the nose and surrounding region of the face. Thus escape of air at the upper edges of the mask may be substantially prevented.
1. A collapsible hygienic face mask cut from a W- folded web of an air-filtering fibrous sheet material, comprising two identical double-walled halves which in their superimposed position before use have a common forward convexly curved edge (5) and two coinciding rearward straight edges (16, 17) corresponding to the folded side edges of the W-folded web, the inner (3, 4) wall portions and outer (l, 2) wall portions of the two halves of the mask being joined together along the common forward curved edge (5) from its ends to the ends (9, 10) of a middle portion thereof located in front of the mouth region of the mask, where the forward edge of the outer wall, constituted by the joined outer wall portions, in said middle portion is spaced from a straight middle portion (13) of the forward edges of the inner wall portions which are joined together by a fold (13) corresponding to the middle fold of the W-folded web, whereby a free space (15) at the mouth region will be formed between the outer and inner walls when the mask is adjusted to the face of a wearer, the inner wall of the mask being unbroken, the two outer wall portions being provided at their rear end portions with openings (20, 21) for exhaled air having passed through the inner walls to said free space between said inner and outer walls.