Respiratory device

Jan. 4, 1938.

2,104,016

W. P. BIGGS

RESPIRATORY DEVICE

Filed Oct. 16, 1935

Sheets-Sheet 1

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Attorney

Jan. 4, 1938.

W. P. BIGGS

RESPIRATORY DEVICE

Filed Oct. 16, 1935

2,104,016

Sheets-Sheet 2

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Patented Jan. 4, 1938

2,104,016

UNITED STATES PATENT OFFICE pig. U IO CA*****ts^*· ---on ing the method of reinforcing that portion which “^w ______-ί 4-V.e τιτΛηνον·

2,104,018

RESPIRATORY device

William P. Biggs, Washington, D. C.

Application October 10, 1935, Serial No. 45,197

Claims. (Cl. 128—146) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757)

This invention relates to a device to protect workers against inhaling fumes arising from paint spraying operations, or the like, and dust from sand blasting, etc.

Among its objects are: . .

To provide an article of the type mentioned that will be effective in accomplishing the purposes for which it is used, that will adjust itself to faces of different sizes and configurations and will not interfere with the wearing of goggles by the user of my invention.

In the drawings: .

Fig. 1 is a side elevational view of a respirator made in accordance with my invention in position on the face of a wearer;

Fig 2 is a section along the median plane defined’by the plane of symmetry of the wearers f 8*C6 *

Fig 3 is an enlarged detail sectional view showpasses over the nose of the wearer;

Fig. 4 is an axial sectional view of one form of the air inlet fitting; .

Fig. 5 is an axial sectional view of an air inlet fitting particularly adapted for use when the air supply is derived from an air hose; .

Fig. 6 shows in axial section the air inlet Atting, a filter canister engageable therewith and an air hose fitting engageable with the canister;

, Fig 7 is a side elevation of the body of the device showing the section lines upon which various sectional views are taken;

Fig. 8 is an enlarged detail section through the fold at the edge of the body.

• Hgs 9 13, and 14 are fragmentary sectional ’ views taken on the broken lines respectively correspondingly numbered in Fig. 7;

Figs. 10 and 11 are sectional views showing the configuration of the rim and the symmetry 0 the two sides on lines 10—10 and 11—11, Hg. 7,

Fig. 12 is a sectional view on the line 12 12,

Fig. 7. .

The present invention is an.improvement over the device shown in my Patent No. 1,926,027, issued September 12,1933, and this application is a continuation in part of my copenffing application Ser. No. 732,817, filed June 28, 1934, now

My improved respirator is of the type some50 times termed a half-mask, that is, it covers merely the nose, mouth, and chin of the wearer as it is primarily intended for use in situations that are not dangerous to the eyes but require the exclusion of noxious gases or dust from the 55 respiratory tract. The body portion 7 is made of soft flexible rubber that gradually decreases in thickness from portion 8, to which the air inlet fitting 9 is secured, to the free edge 10. A narrow zone of the material of the body member 7 substantially equidistant throughout its length from 5 the free edge 10 is formed into a roll 11 having a base line 12, the boundary contour of the base being substantially an ogee curve on each side of the median plane defined by the plane of symmetry of the wearer’s face when the mask is in 10 operative position. The configuration thus defined permits the mask to fit well up on the nose of the wearer but leaves sufficient space below the eyes to allow the use of goggles when desired and brings the edge of body member 7 well back under the chin. As is shown in Figs. 7 and 8, especially in the latter, the rolled portion is of increasing thickness from each edge toward the base thereof and the thinnest part of the body proper is at the junction of the roll with the body wall. , , .

Owing to the rather sharp flexure of the body member along a line substantially coinciding with the center line of a wearer’s nose, the body member would have a tendency to tear easily along the flexure and to prevent this, a piece 13 of fabric is incorporated in that part of the body member that lies over the nose, the said fabric being readily extensible transversely of the nose to permit of adaptation thereof to the wearer’s face but substantially inextensible longitudinally of the ⁿ°On each side of the body member 7 is a pair of buttons 14 formed integrally with the body member the buttons of each pair being roughly equidistant from the adjacent portion of the base 12 of roll II. A piece of stiff wire 15 has one end secured to each of the buttons 14 and is somewhat convex toward the edge of the body member this wire serving as an attaching means for 40 head straps 16 which are engaged therewith to be adjustable lengthwise thereof. __

Air inlet fitting 9 comprises a cylindrical portion 17 having in it a groove 18 to receive rib 19 on body member 7 which locks the fitting and 45 the body member in assembled relation, an enlarged cylindrical portion 20 having threads 21 to engage the threads 22 on filter canister 23, ana a cage or spider 24 to retain the one-way air valve 25. The valve 25 is a disc of light material, 50 preferably mica, that is seatable against the frusto-conical flange'26 to prevent the passage of exhaled air through the inlet fitting but is readily unseatable to permit the passage of fresh air as the wearer inhales. When the device is to ₅₅

2,104,016 ' 2 be used in connection with a supply of air under pressure, a hood 27 is secured to cage 24 to direct the stream of air downwardly into the lower part of the mask and so prevent interference with 5 breathing by such stream, of air. Soft rubber flutter valve 28, of a type well known in this art, is secured to body member 7 in position to lie adjacent the chin of the wearer so that exhaled air readily passes from the body member 7 and 10 also to relieve immediately any excessive pressure set up by air issuing from, the hood 27.

Ordinarily the air surrounding the worker will be breathed after having been drawn through filter canister 23 to eliminate any noxious mat15 ters carried thereby, but if for any reason it is desirable or expedient that the air be taken from a source' of air under pressure, a tube 29 may form a portion of the connection to the air supply, said tube being provided with a fitting 20 30 that engages screw threads 31 on filter canister 23.

The effect of forming roll 11, as above described, is to predispose that part of the body member adjacent the free edge to roll outwardly 25 when pressure is applied adjacent the base 12 of roll ί I in fitting the device upon the face. The base of the roll is relatively rigid and constrains substantially the entire edge of the body member from, the nose to the lower edge of the ³θ jaw to move as a unit, but since the roll passes tinder the chin on a line transverse to that portion of the roll lying against the cheek, it prevents the distortion of body member 7 from, being absorbed merely as an increased roll and compels 35 a relatively wide zone adjacent the edge to move bodily inwardly as though it were being swung on a hinge whereof the axis of rotation lies along the base of roll ί ί, the angle between the portion passing under the chin and that Ijring against 10 the cheek acting as a point of support, or, so to speak, as a bearing for the hinge. An additional factor acting to move the wall of body 7 toward the face arises from the stresses set up by the application of pressure to roll 11. Since the base 45 of the roll is thickened and the material adjacent thereto is thin, such pressure produces the same effect as beginning to wind the wall material around the roll. The layers of material on the outer surface of the wall are thus placed under 50 compression and those on the inner surface are stretched, due to differences in their radii of curvature. Both the compressive and tensional forces tend to swing the wall bodily around the roll as an axis to relieve the strains in the same 55 angular sense as the rolling movement, and thus the wall is moved in toward the face. The wire member IS also serves as a stiffener and stress transmitting member to spread the inward swing of the side of the body member over a larger area GO and prevents any flexure of the body member on a line transverse to the edge. The result of the above described bodily inwardly movement of the sides of member 7 is to increase greatly the area of contact between the body member and the face 05 of the wearer, thus notably augmenting the efficacy of the gas-tight seal between the mask and the face.

In positioning the device upon the face, the lower portion of body member 7 is first placed 70 well back under the chin and the upper portion is then drawn up over the nose in such manner as to stretch body member 7 and the tension thus set up causes the mask to adhere closely to the face. I have found that having the body member 76 7 somewhat under tensional stress effects a much better contact with the face than when the sole force acting is a pressure against the face due to the pull of head straps 16. This capacity for stretching also makes the mask fit perfectly upon faces having wide variations in size and contour. 5 Fig. 7 shows how the thickness of the body 7 decreases outwardly from portion 8 and also that the base of roll 11 is thickened throughout its length, giving to the material in the roll a lunate or crescent cross section. The fragmentary sec- 10 tions are taken from the correspondingly labelled portions of the body as indicated by the broken lines connecting the fragmentary sections to the body. This form, differs from Fig. 1 in that the roll continues over the nose. 15

Fig. 9 is a section taken on the line 9—9, Fig. 7. This discloses the thickened pads 4® that fit against the side of the nose at the inner ends of the orbits of the wearer. It is well known that much of the gas leakage into masks of this kind 20 takes place adjacent the portion passing over the nose and the pads 40 are provided to secure such tightness of fit as will preclude the said leakage.

The invention herein described may be manufactured and used by or for the Government of 25 the United States of America for governmental purposes without the payment of any royalties thereon or therefor.