US 2199230 A
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Description (OCR text may contain errors)
April 30, 1940. N. SCHWARTZ RESPIRATOR Filed Feb. 9, 1957 INVENTOR' flaw)! v wwv v v ill-\hiii Patented Apr. 30, 1940 UNITED STATES. PATENT OFFICE RESPIRATOR Nathan Schwartz, New York, N. Y., assignor to Hygeia Filtering Corporation, New York, N. Y.
Application February 9, 1937, Serial No. 124,851
piece of the respirator and also in adapting the face piece for connection with the filter unit and also in the construction of the filter unit.
More particularly the invention resides in the construction of an air space at the point of connection of the filter unit and the face piece of the respirator. The advantages derived by the construction of such a space has been explained in detail in my copending application Serial No. 122,169. Additional advantages noted by the applicant is that the filter unit or separator may be attached after the face piece has been completed with its valve connection and wire attachments and head band attachments. If attachments have been made prior to the attachment of a filter unit with a rigid base, then there is a distortion to such previous attachments, which distortion is due to needed rough manipulation of the face piece when placing same under the fastener machine. In the improved method the face piece is never placed under a fastener eyelet machine, as will be noted in the specification.
The improvement in this method is the construction of a substantially cup shaped elastic molded rubber material for the connecting purpose, or
the formation of such cup shape by having the aperture in a swatch elastic rubber material smaller than that of the aperture of the wall of the filter unit. Therefore when these are connected with each other, there is a stretching of the smaller rubber material hole and thereby a cup formation occurs, due to an inward inclination resulting in the unstretched part of the said rubber swatch material.
Another feature is the construction of a limited spaced filter unit or separator in a manner whereby the filter material may be undulated and thus provide a large filler area, and also to provide special means at the margins of the frame wall of said filter unit in order to obtain a perfectlysealed juncture between the edges of the filter material and the parts where it is secured.
Another feature is to provide a set back below the nose line of the face piece for the purpose of emplacing the said filter unit. Due to the large undulations in the frame wall of the filter unit and also in the filter material the entroposterior measurement in the present improved respirator is most conveniently located at the said set back portion. At the said location it is neat, unobstructing to vision, and comfortable for the wearer. If the filtering duty of the filter 5 unit is very exacting two such filter units may be attached to the face piece, and in such instance it is to be attached at the sides of the face piece as shown in my copending application,
Serial No. 122,169. 10
Another feature is to provide an apron like downward extension of the face piece which is continuous with the vertical wall of the set back portion and the object thereof is to facilitate the attachment of the molded rubber swatch for con- 15 struction of the air space connection between the filter unit and the face piece.
Another featureis to provide a supporting element for the filter material and also means to insure a sealed and leak proof joint at its mar- 20 ginal attachment.
With the above recited and other objects in view reference is had to the following description and accompanying drawing in which there is exhibited one example or embodiment of the 25 invention, while the claims describe the actual scope of the same.
In the drawing:
Figure 1 is a cross section on line l--l of Figure 2, showing the face piece attached.
Figure 2 isa front view of the separator, part- .ly broken.
Figure 3 is a detail of the filter frame, that is, the frame supporting structure of the separator or filter unit. 35
Figure 4 is a perspective view of the elastic cup shaped conduit means for connecting the sepator and the face piece.
Figure 5 is a perspective of the collar fastener for sealing the filter material to the mar- 40 ginal wall of the frame wall of the filter unit, partly broken.
Figure 6 is a broken portion of the margin of the frame wall, illustrating the tines projecting outwardly at the inturned flange.
' Figure 7 shows a modified form of the invention, in section, illustrating a rubber washer with a metal supporting rim used for sealing the marginal attachment of the filter material, and the 50 frame wall having no undulation to correspond with the indulation of the filter element.
Figure 8 is perspective view of the rubber washer having a metal supporting rim, partly broken. 5
Figure 9 is a cross section of the filter material supporting perforated element.
Referring to the drawing by characters of reference, A designates the face piece of the respirator, B the filter unit, 0 the valve, D the head band, E the connecting member, F the collar fastener for the marginal portion of the filter material, G' the rubber washer sealing means for the second form of attaching the filter material at the marginal portion of the filter frame, S the filter supporting element.
The face piece A is adapted to conform to the face and engages the face at the bridge of the nose and under the chin, and head bands D are used to fasten the said face piece A to head of the wearer. It is made of elastic molded rubber or its equivalent.
The face piece A has a set back below the nose line which set back has a horizontal wall l0, and a vertical wall The vertical wall II has an aperture |2. Below the chin line is another set back, which has provided a depending boss I4 and the said depending boss in its central portion has an opening or aperture l5, the outlet base of an exhaust valve is herein inserted and attached.
The filter unit or separator in the first form of this invention is adapted for high concentration duty. Therefore the depth of the filter frame is greater, the pleats of the filter material is larger and the outlet. aperture is centrally located. Therefore the filter material may be denser and have a large surface area in a limited space. The present arrangement makes it possible to have in one filter unit a surface area equal to the surface area of two filter units. provided for this form of the invention are sufficiently large to provide 24 square inches of surface area and heretofore it required two filter units of this type of construction to provide such a large surface area. The filter frame or frame wall I6 is preferably made of a substantially rigid light aluminum metal or its equivalent.
Figure 1 is a cross section of the filter unit in the first form and the depth here is to be noted in comparison with the depth of the filter unit in the cross section shown in Figure'7, which represents the second form.
In the first form the filter unit has a metal frame wall "5, which has an aperture I1 for communicationwith the air space l8, the wall l6 has small indents l9 for the purpose of providing means for spacing the filter material 20 fromthe said wall l6, and the said wall I6 has a large concentric forward bulge 22 located between the rim 2| and the aperture IT. The purpose of the said forward bulge is to minimize dead air space between the filter material 20 and the wall IS. The said circumferential concentric bulge disposes sectional, or radial pleats. The filter material 20 conforms in configuration with the ,said wall I6 and it therefore also has a sectional or radial undulation. The rim has an inturned flange 23 at its margin, which is adapted for emplacement of the filter material 20.
A collar fastener E is provided, and it has two arms. One arm whichis directed rearward has an inturned flange 24 which is adapted to forcibly snap over outward protrusions 25, which are provided in the rim 2| of the frame wall I 6. When said flange 24 snaps over the protrusion 25 the inwardly directed arm of the collar F impinges upon the filter material 20 which is emplaced over the flange 23 andthereby an air tight juncture is provided. Tines 32 are provided at That is, the pleats the edges of the flange 23 to prevent any slipping of the filter material.
In the first form of the invention the outlet aperture I! is concentric, and purposely so to perform-heavy duty. That is to evenly distribute the filtration work load over the filter material. If the outlet aperture is eccentric the filtration load is concentrated at the area of the said aper-- ture and clogging quickly occurs in that area making the said arrangement less satisfactory than when the aperture is in concentric position.
The location of the separator in the first form is preferably at the setback portion below the nose line. It is convenient to adopt the said location, for the comfort of the wearer. Particularly, vision is undisturbed when so located. The connection of the separator with the face piece is by means of a molded rubber substantially cup shaped frame E with an aperture 26 which is connected with the aperture I! by means of eyelet fastener 2|. A washer 28 is inserted at the rear side to make the connection firm and durable. The fiat margin of frame E is adhesively attached to the vertical wall ll of the set back portion and an air space I8 is thereby created. This permits a swinging motion to the separator at the frame connection portion and thereby jolts to the separator have only little or no effect on the face piece engaging portions and leaks are prevented. This protection is very important for preventing dislocations of the face piece at the nasal area. The vertical wall I I has provided an apron like extension 30 downward which makes it possible to make the attachment of the frame E with ease and comfort.
' The vertical wall II has an aperture l2. Therefore the filtered air passes air space 3| which is between the filter material 20 and the frame wall l6 then the eyelet 21 then the air space l8 then the aperture |2 then to the face piece and the respiratory organs.
Figure 3 illustrates the outward protrusions 25 at the rim 2| of the frame wall I6, and also the concentric aperture I1 and also the concentric circumferential bulge 22, which corresponds with the undulation of the filter material 20 in order to minimize dead air space.
In the second form of this invention as illustrated in Figure 7, the depth of the frame wall is less than in the first form. The reason is that it is intended for light concentration duty. That is for less difiicult filtration. The frame wall l6 has no concentric bulge and has the aperture located eccentrically and the peripheral portion of the rim 2| has an inturned flange 23a. Instead of a collar fastener as in the first form, a molded elastic rubber washer G is provided. The filter material is tucked in under the inturned flange, then the rubber washer is inserted between the rear wall of the flange and the filter material 20, and a leak proof juncture is thus obtained. The washer G has a grit gauze screen 34 attached thereto, for the purpose of deflecting elements that may injurethe filter material 20."
Such a grit gauze screen 34 is in like manner attached to the collar fastener F in the first form of this invention. Both fastening is done with fastening rivets.
The connection of the separator with the face piece A in the second form is made as in the first form as illustrated in Figure 7.
The elastic rubber connecting frame E may be made in a difierent manner than described above. A swatch of elastic rubber material may be used and a smaller size aperture is made than that made in the frame wall l6, and when the two apertures are connected by means of the eyelet fastener, the rubber swatch aperture is stretched to equal the size of the metal frame aperture and-the stretch in the rubber causes a forward bulge of the adjacent nonstretched part of the rubber and thereby a cup formation is produced and this results in the air space It.
It is to be noted that the rubber washer G has an attached metallic rim support 33, which is for the purpose of providing a firm base and support for the insertion of the said washer.
It is also to be notedthat a perforated supporting element S is provided for the filter material in the second form of this invention, and thereby the filter material is supported and spaced from the frame wall l5. A central protrusion i9 is provided for spacing the perforated element from the frame wall 86. The element S extends circumferentially .to the edge of the inturned flange 23a, and preferably, somewhat distal to the said flange 23a, so that the element may readily be removed when required. However the element is to extend near enough to the said flange 23a to be in a position to influence an outward pressure upon the filter material and thereby assist the flange in providing and maintaining a leak proof joint. Therefore the said supporting element is preferably a light resilient perforated metal or wire screen or an equivalent material.
For the purpose of this invention the term leak proof as herein used, means, proof against passage of unfiltered air.
It is to be noted that the improvement in this invention in the provision of a resilient supporting element S in connection with an inturned flange provided at the margin of the frame wall It, whereby the said element is located in a manner to exert an outward pressure at an influential point with relation to the said flange, furnishes a needed solution forthe problem of possible leaks at a joint where an inturned flange is relied upon to secure the edges of the filter material. In workshops where respirators are needed for pro tection against dust fumes and injurious gases or other extraneous particles, there is frequently present extraneous substances in the air that exert damaging influences upon the filter material. Moisture, acids and alkalies may be mentioned. Therefore the effect of such extraneous matter may be to soften the marginal flange engaging section of the filter material and thereby loosen the joint and cause a leak thereat. However with the improved supporting element S herein provided that danger is eliminated.
The collar fastener F in the first form of the invention herein described has a similar distinct advantage'in impinging tightly upon the said filter material and thereby eliminating any leaky possibilities, at the marginal securing joint.
The supporting element S may be made of a light aluminum metal with an alloy of brass to provide. a resiliency to the support. with ample perforations to permit a free and unobstructed air flow. Also a wire screen having similar supporting properties and providing a free air flow may perform the required functions. The preferred perforated supporting element is'a light metallic resilient material or its equivalent.
Having thus described my invention, I claim as new and desire to secure by Letters Patent as follows:
1. A respirator including a face piece having an intake port, a filter unit having a frame wall with undulations, an outlet port and marginal means, and filter material, and the said filter material is removably secured at its edges to the margin of said frame wall by the said means, and an air conduit consisting of a substantially cup shaped flexible element communicating respectively. with the intake and outlet ports and constituting means of connection between the face piece and the filter unit.
2. A respirator having a face piece connected with a filter unit which filter unit has filter material and marginal means for removably securing the said filter material at the edges thereof, and the said means includes a surrounding marginal wall, with the periphery of said wall having an inturned flange and the edges of said flanges having outwardly directed tines, and at the outer side of said wall extrusions are provided, and a resilient collar fastener having two arms one directed inward and the other rearward, and the latter arm having an inturned flange at its marginal end, and the size of said fastener is overlappingly fitting the said wall and the saidfilter material is emplaced over the saidtined flanges, and the fastener is placed over the filter material and the said wall, and the inturned flange of the collar fastener is snapped over the said extrusions whereby the inturned arm impinges the filter material against the tined flanges and thus provides a leak proof joint.
3. A filter unit for filter type respirators having a frame wall with a central protrusion and a peripheral inwardly directed groove, the outer wall of the said groove being formed by'a substantially rigid inturned flange, filter material and a foraminous supporting element for the said material, the said material being mounted at the said groove with the said element being disposed rearward thereto and extending to the marginal portion thereof and the said element confronts the said protrusion whereby it has a forward pressure exerted thereto, and thereby the said element exerts a forward pressure to the said material and provides a leak proof mounting at the said groove for varied thicknesses of filter material.
4. A filter unit for filter type respirators, including a substantially stiff frame wall, filter material and a perforated supporting element for the said material, and a substantially rigid in-v turned flange at the margin of the said frame wall, the said material being removably secured at its margin edges by the said flange impinging thereon, and the said element being disposed at the inner side of said material in supporting relation thereto with the margin thereof so located with reference to the flange as to impinge the marginal portion of the material against the flange to insure a leak proof joint thereat.
5. A respirator including a face piece having a set back portion below the nose line and an inlet port, a filter unit including an undulated 'frame wall, an outlet port, marginal means, an undulated filter material, and a filter supporting element, and the said filter material is removably secured at its edges at the margin of said wall by the said means and supported at its inner side by the said element, and an air conduit connecting the said face piece and the said filter unit and establishing communication therebetween, and the said filter unit is located at the said set back portion of the face piece and is disposed confronting relation thereto.
NATHAN scHwAR'rz. 15