JPH02268772A - Breathing mask - Google Patents

Abstract

PURPOSE: To obtain a respiration mask which filtrates particles and/or harmful gas, and toxic gas from breathing air by manufacturing it from a flexible air- impermeable and foaming material and providing it with a shell having a hole and with a filter liner which filters the air passing through the hole. CONSTITUTION: This respiration mask 10 is equipped with an outside shell 11 which is thermally formed from a single-layer sheet of a cross-linked air- impermeable independent foaming material and a discharge valve 16. The respiration mask 10 can be worn comfortably for a long period of time by making the shell 11 soft enough to fit easily around the nose and mouth to the outline of the wearer. Having a hole 12 passing the front of the shell 11 of the mask, when mask 10 is to be discarded after use, the outside filter 18 is attached on the hole 12 by an adhesive and it is possible to be attached removably to the outside of the shell 11 of the mask by a maintenance instrument when the mask is reusable. The filter 17 is to be attached by an adhesive to the inside of the shell 11 of the mask on the hole 12, for a disposable mask and for a reusable mask it can be attached detachably by a snap type maintenance instrument 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a respirator for covering the nose and mouth and for filtering breathing air, and in particular for a respirator having a molded or thermoformed non-perforated or perforated shell and a respirator that covers the nose and mouth and filters harmful substances or gases. The invention relates to a respirator having a filtration carton or ridges or one or more liners or layers of fabric or other F-suitable material impregnated with substances that remove other substances from the breathing air.

In summary, the invention is reusable or disposable;
A respirator for filtering particulate matter and/or noxious gases from breathing air is disclosed. This mask is
Polymeric closed-cell foam that is impermeable to air and has excellent shape retention that allows the edges of the mask to fit and seal around the wearer's face around the nose and mouth.
The shell (s
hell). The shell of the foam mask has one or more holes through the central portion, and a filter is mounted over this hole, thereby passing all inhaled air through the hole. . A one-way valve is installed through the violet of the mask shell to vent exhalation air.

A review of the prior art shows that a wide variety of face masks or respirators exist for the treatment of breathing air. Generally, prior art masks fall into two categories. That is,
These include disposable or single-use respirators and replaceable cartridge-type respirators.

-a, prior art disposable masks are made from a permeable fibrous medium formed into a cup shape to conform to the contours of the wearer's face. In some masks, the fibrous media is shaped to conform to the wearer's face and at the same time achieve a seal against the flow of toxic dust and mists into the breathing air chamber. In other masks, a noseclip is attached to the respiratory mask;
and used to achieve a seal around the nasal area.

In most prior art disposable textile media masks, treatment and filtration of the breathing air is one of the major areas of the respirator.
This is achieved by airflow through the minute. Large amounts of filtration media are used to create a seal for the entire mask, plus excess waste from removal between shells.
Although such masks are relatively expensive, they are advantageous because they provide a relatively low pressure drop across the filtration media for the same breathing air volumetric flow rate. and thus lack the ability to hold a sufficient charge of air treatment substances that absorb toxic gases, fumes, vapors, etc., to protect the wearer in hazardous environments. cannot meet government approval standards or requirements for such applications.

For example, to meet government requirements for paint spraying, organic vapors, acid gases, or pesticide spraying, fiber media for disposable respirators should be filled with a sufficient loading of activated carbon granules (approximately 10
0 grams) is difficult to impregnate. This is due to the limited capacity of the fibrous media to entrain or load or impregnate the toxic gas treatment media. In some cases, even when relatively thick fibrous shells are used, the amount of activated carbon entrapped in the respirator shell may be insufficient for certification or approval for paint spraying applications.
National Standard for Occupational Safety and Health (NIO8H) J
insufficient to meet the requirements.

In such cases, masks lacking N103H approval are typically referred to as hazardous masks.

In many cases where the filtration media is impregnated with air treatment substances or loaded with additional fibrous media, the respirator is relatively thick and good fit and seal of the respirator is difficult to achieve. . In these cases, nose clips and/or
Alternatively, wide, low-stretch, strong straps are used to apply a strong force to pull the mask against the wearer's face. As a result, an air seal is obtained by contorting the wearer's face to fit around the mask rather than deforming the mask to fit the wearer's face. Needless to say, such masks are not comfortable to wear.

Therefore, the limiting factor in making a single-use respirator that meets the NlO3H requirements is that the fibers that hold the activated carbon granule weight of approximately 100 grams while keeping the total weight of the mask within the limits that can be held The problem lies in the fact that it is very difficult to produce media masks.

A review of prior art masks indicates that many formations of disposable masks involve heating, stretching, and/or compressive filling of the filtration media; such manufacturing factors affect the filtration media in terms of perturbation rate and pressure drop. According to a review of the prior art, in many disposable masks, the area that contacts the wearer's face has a fibrous nature, which would adversely affect the efficiency of It is not possible to provide an airtight seal similar to elastomeric material seals as required by enforcement agencies for applications.

In the manufacture of respirators designed for single use or a finite number of uses, the cost of the filtration media represents a significant portion of the total manufacturing cost.

As the cost of the media (including removed waste) increases, the overall competitiveness of the product in the market is reduced considerably. This is true in all respirators targeted for applications in particulate filtration, including toxic dust and mists; in many such masks, the area of V permeable media in the final product is is equal to the area of the shell.

In the prior art, numerous products and patents are directed to achieving an effective airtight seal between the perimeter of the mask shell and the wearer's face. In some cases, polymeric beads, rims, flaps, or combinations thereof are added to the periphery of the respirator of the textile shell to provide non-transmission around the periphery of the respirator in areas that come into contact with the wearer's face. Except for the use of thin rims of closed-cell elastomeric materials or foam, a review of prior art masks and patents does not suggest impermeable polymeric foam materials or Use is not permitted.

On the other hand, prior art replaceable cartridge masks
Elastomeric facepieces, which generally include elastomeric facepieces designed to closely fit and achieve an airtight seal with the wearer's face, typically have one opening. and is suitable for accommodating a removably mounted cartridge for the treatment of breathing air. Elastomeric facepieces are also typically fitted with one-way discharge valves.

In order to achieve and maintain an air-tight seal along the circumference of the cartridge, the shell of the mask is made stiffer, either by ridges or by the use of thicker material, particularly around the cartridge-receiving opening. For this reason, respirators are generally of heavy construction and thus feel heavy on the wearer's face. The overall weight of the basic respirator shell with mounting straps and two replaceable activated carbon granule filters is 327
Gram. The weight of two filter cartridges is 183
Gram. The ratio of the weight of the mask functional components (filter) to the total weight of the mask is R = 182/
327=0.56.

From the point of view of the comfort of the mask wearer, it is desirable to keep the ratio R as high as possible, especially for masks that perform their intended function but require relatively heavy functional components (filters). In such a case, the closer R is to the limit value of 1, the least discomfort the wearer will experience.

Generally speaking, NIO8H approved masks that use removably attached replaceable cartridges are expensive. This is because a significant initial capital investment must be made for a durable respirator shell. Other indirect costs include the cost of periodic shell cleaning, sterilization, and inspection for cuts, cracks, leaks, etc., and storage. In some workplaces, individuals using such durable respirators prefer or require that other co-workers do not use the same respirator shell at other times. This is usually done to prevent diseases that are transmitted by breathing contaminated air or through skin or saliva in contact with a contaminated mask shell.

In this case, the shell of the respirator is numbered and designated for use only by the individual.

Furthermore, in some applications, for example in environments contaminated with asbestos fibers, shaking the mask shell after use contaminates the clean environment.

In such cases, it is desirable to dispose of the mask shell and the entire air flushing cartridge after each use; such disposal is expensive since the main cost is that of the mask shell; on the other hand, Recently adopted government regulations have denied approval of traditional disposable respirators for use in environments contaminated with asbestos fibers.

Many durable masks, especially approved ones, are
In order to achieve an effective seal with the wearer's face, strong force is required to pull the mask against the wearer's face.

When such masks are constructed to be suitable for harsh use environments, the head top is designed to prevent the mask from falling off the wearer's face and to maintain a complete seal with the wearer's face. The need for a band arises. Such headtop bands typically diverge from the above-ear bands and are placed on the top of the mask wearer's head. Such headtop bands are particularly undesirable when the top of the wearer's head at the location of the headtop band is bald.

As concluded from the above, it is an inexpensive, single-user (single-use or repeated-use) respirator with an eave that fits snugly around the wearer's face and achieves a complete airtight seal. There is a need in the art for flexible shells. Such a mask would have a fit and seal comparable to that obtained with currently available elastomeric facepieces, while being lightweight and thus feeling relatively comfortable and having a specific Sufficient air treatment or filtration media and/or equipment loading can be maintained to provide the desired protection against environmental hazards.

The need in the prior art is met by the respiratory mask taught and claimed by the present invention. The new mask bridges the dark gap between unapproved disposable masks and expensive approved interchangeable cartridge respirators. This mask benefits from the reduced cost of V-permeation media due to the use of relatively small portions of such media since the media does not have to undergo adverse processing conditions such as heating, stretching, and/or compression filling. Features.

The above needs of the prior art are met by the novel respirator of the present invention, which is non-disposable or single-use, which filters particulate matter, noxious gases and toxic gases from inhaled air, and which is relatively lightweight. It is soft and flexible and forms an excellent seal to the wearer's face around the nose and mouth without the need for tight elastic straps, and does not distort the wearer's face to achieve a good seal. They are comfortable to wear for long periods of time, and are relatively inexpensive. Such a respirator is an effectively functioning alternative to prior art rubber shell masks, so that each worker can have his or her own reusable mask; Alternatively, the mask can be discarded after one use.

The primary embodiment of the new mask of the present invention has an outer shell thermoformed from a sheet of crosslinked closed cell foam. The foam shell is impermeable to air, while being soft and pliable, and has excellent shape retention and elasticity. The central region of the shell is perforated with a plurality of holes to allow inhaled air to pass through the air impermeable shell and a filtration liner located on the inside or outside of the mask above the holes. The shell of this mask supports a variety of F1 filtration filters ranging from simple fiber F# filtration liners to filter dust or mists to fiber sheet liners impregnated with activated carbon to filter noxious or toxic gases and other hazardous substances. Tough enough for. The filter can be removably held inside or outside the shell over the hole by a force fit retainer or clip, and can be easily removed for filter replacement. Removable filters can also be attached with self-adhesive strips around the perimeter of the filter. A filter can also be thermally bonded or otherwise permanently bonded to the inside or outside of the mask in one of the holes to create a disposable mask. When filters are mounted both inside and outside the shell above the holes, the outside filter serves as a pre-filter and the inside filter serves as a post-filter.

A one-way exhaust valve can be installed through the wall of the foam mask shell to exhaust the exhaled air. The exhaust valve is located in a position where it does not interfere with the filter liner.

In an alternative embodiment of the invention, the basic shell can be formed from two parts.

The periphery of the shell, which contacts the wearer's face to create an airtight seal and to which the strap is attached, is formed from an air impermeable foam material. A piece of air permeable foam is attached to the shell periphery by heat bonding, adhesive or other methods, eliminating the need for holes in the main embodiment of the invention. The filter is further attached to the inside and/or outside of the mask over the air permeable foam material.

The filter is permanently attached for disposable masks and removable as described above for reusable masks.

In yet another embodiment of the invention, the closed cell foam material from which the shell of the mask is thermoformed is made from a layered material. The outermost layer on the side mask shell that contacts the face may be the best material that allows more comfortable wearing of the mask or reduces chafing or exhibits a hypoallergenic effect. Other layers may be chosen for shape retention, aesthetic appearance, or multiple ponding reasons.

In another embodiment of the invention, one or more filter cartridges are not attached to the inside and/or outside of the foam shell, but rather through the walls of the shell. The curl ridge is removably fastened to the collar and is attached and fastened through the foam shell.

In yet another alternative embodiment of the invention.

Rather than being formed from closed cell foam, the mask shell can be manufactured by aging a sheet of commercially available synthetic non-oven filtration material. A shell shaped in this way can be cup-shaped. During molding, a piece of fibrous sheet material impregnated with activated carbon or other fugitive material is heat bonded or otherwise attached to the inside of the mask and does not overlap the edges of the mask. In this method, the basic mask shell is formed. 7 (The filtration material provides pre-filtration and the filtration liner attached to the inside of the shell provides ttt filtration.

The invention will be better understood from reading the following detailed description in conjunction with the drawings.

According to the present invention, it is advantageous to use non-permeable polymeric foams as the basic respiratory mask shell; the use of such foams having a fairly low density generally results in a low weight mask; Such a high ratio, leading to a highly desirable high filtration media weight ratio R to the overall weight of the mask, is desirable not only from a comfort point of view, but also especially for military gas masks because of cost and overall weight savings. .

For the purpose of describing the present invention, a shell of impermeable polymeric foam is defined as a medium impermeable to gas and liquid flow, and a semi-a-tight dense Jjj (6
2.4lb+a/It', 1.00g/am')
The shell medium of the product and mask has a specific gravity that is lower than the solid density of the polymer or combination of polymers from which it is made. For example, a non-permeable polyethylene foam shell weighs 62.4 lbm/ft”x 0 .

9 1=56.784 lbm/fL3(0,91
Similarly, the foam shell of nylon 66 has a lower density than nylon 62,4 lbm/
ft'x 1.14 =71.136 1bm/ft
3(1, i 4H/cs'),
etc. According to the provisions of paragraph E, an initially permeable fibrous sheet or an open cell foam sheet coated or sealed on one or both sides to make it impermeable to fluid flow is classified as an impermeable foam. defined as a body. Other materials that can alternatively be used to make the shell of the present mask include polymer sheets or films, 4a fiber webs, textiles, open cell foam and/or closed cell foam combinations. Or laminate.

The low density of the foam allows it to form a thick but lightweight respiratory mask shell. this is.

A thicker shell provides greater overall stiffness, allowing the mask shell to hold its shape and hold a platter of filtration or air treatment media without sacrificing ease of surface deformation of the shell. Particularly desirable for This is a very important feature for effective facial fit and seal. For example, 21b,/It' (approximately 0.032 g/cm) manufactured by Voltek, Inc.
1/8 inch (approximately 3.2t++) J with a density of ')
Light crosslinked closed cell polyethylene foam of T.
Formed into a cup-shaped shell respirator with rearwardly projecting protrusions of the type disclosed in U.S. Pat. . These projections are shown in FIGS. 211, 3, 7 and 9. A formed foam shell weighing about 3 grams (commonly used for lightweight respirators) has two stretchable lightweight 174-inch widths weighing about 2 grams (commonly used for lightweight respirators). Attached to the braided elastic straps of the
Holds a load of 150 grams on the outside of its surface or on its inside without falling off the wearer's face without soaking or compromising the airtight seal between the surroundings and the wearer's face. was completed. The resulting mask had a ratio lλ of 150/(150+2+-3)=0.97 and was more comfortable for long-term wear than approved masks that were heavier by -m. Additionally, it did not require a head-top strap like many approved masks. Generally, an activated carbon granule charge of approximately 100 grams and other media is sufficient to provide the mask wearer with protection against various toxic gases, vapors, etc., depending on the requirements. be.

It is worth noting that from the point of view of economy and wearing comfort, it is desirable to use narrower, lighter and more stretchable bands to hold the mask on the face. This is all possible with the present invention.

Compared to continuous-modality polymeric materials, polymeric foam shells are easier to cut and drill. thus,
It is possible to obtain a shell with an excellent face seal while using easier and less investment equipment manufacturing techniques, such as thermoforming. The cutting and/or drilling process is carried out in the shell of a molded foam mask obtained by aging molding, injection molding, rotational molding, blow molding or other manufacturing techniques. Using multiple holes or a single large cutout has the same function, but it is preferable to use multiple holes, as this prevents the unsupported medium from bulging outward or inward during exhalation and inhalation. Filtration to minimize shrinkage and to obtain better shape retention and load support inside and/or outside of the mask shell and to secure the media without blocking air passages. Particularly useful for obtaining additional fixed points within a region. Such fixation points subside to maintain the shape of the filtration media even when the interior of the mask is very humid or when such media is moistened by high humidity.

The characteristics of shape retention and resistance to collapse in humid conditions are highly desirable and in some cases required for applications.

The use of foam on the inner and/or outer surfaces of the shell also provides a flexible surface. Such flexibility of the inner and/or outer surfaces has the added advantage of providing a comfortable surface for obtaining a perfect seal between the replaceable cartridge or media liner and the shell of the mask. I will provide a.

In the present invention, at least one of the polymeric foam materials
The shell of the mask consists of two layers of non-permeable laminate! It can be used for iJ construction. The use of such a laminate makes it possible to obtain a combination of color, softness and/or high tackiness of the surface of the mask shell in contact with the wearer's face and hardness of the outer shell, While maintaining a low overall weight of the mask's shell and maintaining Food and Drug Administration (FDA) approved and non-approved materials. Such laminates also include the entire material and/or
Alternatively, it can reduce manufacturing costs and increase the elastic recovery from deformation, strength and mechanical properties of the mask shell, especially at the anchoring points or threading points or strap holes.

The density of the foam can be as low as 4 oz/ft3. Experiments conducted on lightly crosslinked polyethylene foam mask shells with various densities yielded a preferred (though not necessarily optimal) density of 4 lb/ft3 (about 0.064 g/cm3). The use of elastomeric polymer foams makes it possible to simultaneously obtain a desirable combination of wearer comfort, product competitiveness in the market, and functional characteristics of a mask not possible with prior art masks. 0 For example, (1) snugly adheres to the wearer's facial skin around the area where the mask contacts the user's face, and thus is as effective as that obtained from conventional solid-phase elastomeric or rubber facepieces; Guarantees an airtight seal.

(2) The ease of deformation of the form relieves the contact force between the wearer's face and the mask shell to spread the tensile force applied to the mask seal over a large surface area of the wearer's face, which This makes it possible to eliminate rough or excessive spots on the face of the wearer, which would normally cause redness on the wearer's face, even after a short duration of wearing the mask.

(3) The lightness of the shell provides improved wearer comfort;
Increasing this ratio, which results in an increase in the ratio R of heavy liquid of the filtration media to the total weight of the mask, reduces the overall material cost of the mask and increases its competitiveness in the market. It also makes the use of such foam mask shells equally attractive for hazardous mask (non-approved) and NI OS H approved applications from a product cost standpoint. The lightness of the shell allows the use of narrower, lighter and easily stretchable bands, without excessive force.
and holding the mask shell against the wearer's face, preferably without a helmet band.

(4) Obtaining a strong but light mask shell that can meet N103H specifications for some applications.

(5) The use of elastomeric material foams such as polyurethane or lightly crosslinked polyethylene increases shape retention and recovery from deformation, and Nl for elastomeric facepieces for some applications.
03H requirements and other desirable features as described in this application.

The masks of the present invention feature a facepiece that covers the wearer's mouth and nose and generally conforms to the contours of the wearer's face in the area of contact between the wearer's face and the facepiece.

Furthermore, the mask has a rear portion made of a non-permeable material, preferably a closed cell polymeric foam or a generally non-permeable polymeric foam. The rear portion has a circumferential area that contacts the wearer's face. This area is impermeable to air and is flexible, soft, and highly adhesive to provide an airtight and complete seal between the wearer's face and the entire circumferential area. , generally made from elastomeric materials. To reduce manufacturing costs, the circumferential area can be integrated with the rear part. It is also
It may also be an additional segment attached to the side of the rear portion of the wearer's face.

There is also a front section made of a non-permeable material, preferably a closed cell polymeric foam or a generally non-permeable polymeric foam. To reduce manufacturing costs, the anterior and posterior sections may be formed from polymeric closed cell foam or generally impermeable polymeric foam, laminates of light impermeable polymeric materials or foams, and/or other polymeric materials. It can be an integral part of one continuous impermeable shell. The front section can also be attached to the rear section in such a way as to provide a complete and continuous airtight seal at the point connecting the front section to the rear section.

The front portion has at least one circumferential area on the inner surface facing the wearer's face and/or on the outer surface. The front part is protected against the passage of air, gases, particulates, vapors, etc. by having a wide cut-out area or preferably several small cut-out areas, holes or perforations surrounded by a circumferential area. Be made transparent.

At least one air-permeable treatment medium, such as a replaceable or permanently attached cartridge, is attached to the inside and/or outside of the forward section in a gas-tight manner along a circumferential region, thereby allowing the air treatment medium to between the inner surface, the inner surface of the front part, the inner surface of the rear part and the wearer's face (!
Creates a rare processing air chamber.

If more than one air permeable treatment medium is used, the first medium is attached to the outside of the front section, thereby acting as a pretreatment or initial prefiltration medium. This is the coating f′
This is the case for applications such as blue masks for li.

The air permeable treatment medium may be formed mechanically or by friction, or by an interference or snap fit,
permanently or removably attached to the outer portion in one or more locations by one or a combination of melting or fusion and cosolidiary.

The outer portion may be shaped to accommodate, in one or more locations, one or more cartridges for treatment of breathing air. The cartridges can be arranged in series or parallel to provide breathing air treatment. Additionally, the outer portion may be a bellows shaped to accommodate each cartridge.

FIG. 1 shows a respiratory mask 10 having only an inner filter.
The front view of the mask is not shown, and the mask comprises an outer shell 11 thermoformed from a single layer sheet of crosslinked closed cell foam that is impermeable to air. Although various foam materials can be used.

In the embodiment of the invention disclosed herein, a 3/16 inch thick foam, commercially available from Voltech, a division of United FoaJ, is used. The foam material is soft, yet thick enough that the thermoformed shell has a soaked resilience, and yet stiff enough that the thermoformed shell has excellent shape retention, as shown in FIG. A filter liner and retainer can be supported behind the hole 12, as shown in FIG. The hole 12 through the central portion of the mask shell 11 can be drilled into the foam trunk prior to thermoforming of the mask shell 11, or after the shell 11 is formed. The holes 12 are preferably 17/4 inner (approximately 635 ml 11) in diameter and the spacing between the holes is preferably half the hole diameter, although those skilled in the art will You may be able to change the interval.

The shell 11 of the mask has two elastic straps 13 and 14 attached to a rim 15. The straps 13 and 14 go behind the head of the wearer of the mask 10 when the mask is worn, and the rim 15 of the shell 11 of the mask.
In a preferred embodiment of the invention, straps 13 and 14 hold the mask 1o comfortably against the wearer's face without distorting the face while maintaining an airtight seal between the rim and the wearer's face. 15, but can also be attached by sewing, hot gluing, or adhesive by methods known in the art. Although straps 13 and 14 are shown as strips of elastic material, in alternative embodiments of the invention strap 1
3 and 14 can be made adjustable by methods known in the art.

In FIG. 1, a one-way vent valve 16 of a known type widely used in the respiratory mask art is shown. valve 16
are mounted in holes or suitably shaped cavities (FIGS. 2 and 3) through the lower portion of the shell 11 of the mask, with a filtration liner (not shown) inside the mask 10 behind all holes 12. The valve 16 allows the mask wearer to inhale through the filtration liner, but upon exhalation, the valve 16 opens to expel the exhaled air.

Although not clearly shown in FIG. 1, as shown in FIG. There is a filter 17 attached to the.

As described in more detail herein, the inner filter 17 shown in FIGS. 3 and 4U:4 can also be used with a snap-on retainer (as shown) (not shown) can be held inside the shell 11 of the mask. In reusable respirators, the filter can be replaced periodically for continued use in the same environment, or replaced with a new type of filter for use in a new environment.

However, the snap-on retainer can also be dispensed with, and the filter 17 can be permanently attached to the inside of the mask shell 11 by heat bonding or adhesive by methods known in the art, and can be used only once and then You can also make disposable respirators that are thrown away.

When wearing the respirator 10 shown in FIG. 1, the shell of the mask is flexible so that it easily conforms to the contours of the wearer's face around the nose and mouth and achieves a good seal. It is shaped so that no distortion of the wearer's face is required. Furthermore, the rim 15 is sufficiently soft - lastly, due to the manufacturing method, it fits very comfortably and snugly to the wearer's face, requiring less force than rigid prior art disposable masks. Therefore, the respiratory mask 10 can be comfortably worn for a long period of time.

FIG. 2 shows a side cross-sectional view of the respirator 10 with an outer filter 18 attached, which is also thermoformed from a single layer sheet of cross-linked closed cell foam that is impermeable to air. outer shell 11 and discharge valve 16
and. The mask IO also has a hole 12 through the front side of the foam mask shell 11. If mask 10 is disposable, outer filter 18 is attached over hole 12 by thermal bonding or adhesive to create a disposable mask. However, the outer filter 18 can also be attached to the outside of the mask shell 11 by placing a retainer, as shown with reference to FIG. 5 and described hereafter, to make a reusable respirator. It can also be removably attached to the In reusable respiratory masks.

Filters can be replaced periodically for continued use in the same environment, or replaced with new filter types for use in new environments.

FIG. 3 shows a side cross-sectional view of the respiratory mask 10, in which a one-way outlet valve 16 is installed through the wall of the lower part of the mask shell 11, in which case it does not interfere with the filter 17, which is a disposable mask. The filter 17 can be permanently attached to the inside of the mask shell 11 over the hole 12 by heat bonding or adhesive, or the filter 17 can be snapped on as shown to create a reusable mask. Hole 12 by type holder 19
can be removably attached to the inside of the shell 11 of the mask on top of the mask. The retainer 19 is shown in more detail in FIG. 4 and is retained in a recess molded around the inner wall of the shell 11 so that the retainer 19 can be attached to the inside of the shell 11 of the mask to provide a replaceable filter 17. The structure of an exemplary multilayer filter 17 is shown in FIG. Basically, the inner filter 17 is prefabricated with one or more layers and then stamped into flat rectangular or other shaped pieces. When the filter 17 is multilayer,
There is a first layer of fibrous material (not shown) impregnated with activated carbon, and there is a second layer (not shown) attached to the activated carbon layer.

The second layer is preferably a reticulated layer (
net 1 ayer), the filter 17 fits inside the middle part of the shell 11 of the mask and covers all the holes 12. Due to the flexibility of the filter 17, it fits inside the middle part of the shell 11 of the mask. Easy to fit.

FIG. 4 shows an isometric cross-sectional view of the snap-type retainer 19.
The retainer 19 is molded from a flexible thermoplastic material that is flexible when inserted into the interior of the mask shell 11 and is retained in the groove as shown in detail in Figure 4a. The plastic from which the retainer] 9 is molded is also strong and combined with the thickness of the retainer does not break easily.

The outer edge 20 snaps into the aforementioned groove around the interior of the mask shell 11 to retain the filter 17 inside the mask shell 11. When assembling the respiratory mask 10, the retainer one also deforms to match the inner contours of the mask shell 11. Also, the inner filter 17 is attached to the inner surface of the mask shell 11 above the hole 12.
There are ribs 21 that serve to hold the . The rib 21 is
With a large space between them, the lick filter 1
It will be appreciated that the retainer 19 working with the mask can have many design variations that do not overly impede the flow of inhaled air through the mask 7 and into the inside of the mask 10. When it is desired to replace the filter 17, remove the retainer from inside the shell 11 of the mask by grasping the retainer 19 near one edge and pulling.The used filter 17 is then removed and replaced with a new filter 17. It is replaced and the retainer 19 is reinstalled.

In Figure 4a a cross-sectional view of the shell 11 of the mask is shown showing the grooves 22 formed around the inside of the shell 11 during thermoforming. Retainer 19 is shown in the snap-in position, with outer edges 20 engaged in a force fit in grooves 22 . Upon insertion, the retainer 19 deforms to hold the filter 17 inside the mask shell 11 against the hole 12. This force fit engagement maintains a good seal so that the intake air does not pass around the filter 17.

Although the description of FIGS. 1-3 has been described for a mask in which the filter 17 is replaceable once removed, the retaining means 19 can be omitted and the filter 17 can be placed inside the shell 11 of the mask and/or It can be bonded to the outside by thermal bonding or adhesive. This creates a disposable respirator 10 that is replaced after one use.

The internal view of the mask 10 shown in FIG. 3 is of the form of the mask with only an internal filter 17.

In this type, a snap-on retainer 19 is used. When the mask 10 is of the type having both an inner filter 17 (FIG. 1) and an outer filter 18 (FIG. 2), different filter retention means can be used. This different holding means is the holding means 23 shown in FIG.
It is. The holding means 23 connects and holds both the inner filter 17 and the outer filter 18 at the same time. The retaining means 23 consist of pieces 24 to 27 molded from thermoplastic or made from metal. Pieces 24 are rectangular or other suitable shapes, and the frame has a number of central area holes or rib pieces, each serving the same purpose as a single snap-on retainer, and as shown. To,
The piece 26 with a number of protrusions 25 around the edges is another rectangular or other suitable shape, and the frame 24
has the same dimensions as and also has hole or rib elements, but instead of projections 25 it has a number of holes 27.

Hole 27 is located around the edge of frame piece 26 and is precisely aligned with projection 25 around the edge of frame piece 24. In manufacturing, the shell 11 of the mask has projections 25
It has a large number of holes 28 that are equal to the number of holes 27 and have the same diameter. These special holes 28 through the shell 11 of the mask surround the holes 12 through which the inhaled air passes,
The outer dimensions of the edges of filters 17 and 18 are such that they just fit within protrusion 25. Alternatively, filters 17 and 18 may have the same outer edge dimensions as frame pieces 24 and 26. can.

In this case there are a number of holes (not shown) passing through the filters 17 and 18 around the edges, the diameter of these holes is the same as the hole 27 and they are in the same position.

During assembly of the filter holder 23 to the shell 11 of a mask with a filter without holes, the outer filter 18 is placed on the lip of the frame piece 24 between the protrusions 25 . The protrusion 25 is then inserted from the front side of the mask 10 through a corresponding hole around the hole 12 into the shell 1 of the mask.
It is inserted inside 1. The frame piece 26 is then
The part of the protrusion 25 placed inside the shell 11 of the mask, so that the part of the mask extending inside the shell 11 is located in the hole 27.
pass through. The retainer clip 29 is then attached to each protrusion 25.
and between the frame pieces 24 and 26, the mask shell 11 and the filter 1 are placed together as shown in FIG.
Pressed to grab 7 and 18. Frame piece 24
And 26 ribs.

Filters 17 and 1 are connected to the holes 12 through which the intake air passes.
Hold 8.

When the filters 17 and 18 have holes around their periphery, the outer filter 18 is first attached to the frame piece so that the protrusion 25 passes through the six. After the frame piece 24 has been attached to the mask shell 11 as described above, the inner filter 17 is assembled so that the protrusion 25 passes through the hole around its periphery. Frame piece 26 and clip 29 are assembled as described above. Those skilled in the art will devise many different ways to cooperatively hold the inner and outer filters 17 and 18 against the mask shell 11 so that inhaled air cannot pass around the edges of the liner. It is clear that it could be done.

FIG. 6 illustrates a filter 17 or 18 which is a multilayer filter. This exemplary multilayer filter has a first layer 29 of fibrous material used to filter dust and mists from the inhaled air.

The second layer 30 is a 4M fiber material impregnated with activated carbon or other material to absorb noxious gases or toxic gases and mists and airborne particulate matter; such material is used in the extraction system ( Extraction
available from Steso Corporation (Norwood, Mass.). 0 where the reticulated material forms the third layer 31
The layer 31 is either the waste of the inner filter 17 facing the inside of the shell 11 of the mask, or the layer of the filter 18 found on the outside of the mask 10, and the layer 31 is provided for aesthetic appearance only. is “DELNET (DELN)”.
ET) J and Hercules
It is a non*oven porous reticulated material manufactured by Co., Ltd.

An alternative embodiment of the invention is shown in FIG. 7, in which a snap-on retainer 19 or combination as described above is shown.

A retainer 23 is not used; rather, a self-adhesive strip 32 attached to the edge holds the outer filter 1 in place.
Provision is made for removably attaching 8. To realize this embodiment, a flat, rectangular, oval or other lance fitting piece 33 is attached to the front surface of the mask shell 11, as shown in FIG. The purpose of the mounting piece 33 is to provide a base onto which the self-adhesive filter 18 can be mounted. Installation is part 3
3 surrounds the hole 12 through which the intake air passes and is attached by thermal bonding, adhesive bonding or other techniques. The wearer of the mask IO takes off the replacement outer filter 18, which has a self-adhesive strip attached around the green and attaches an easily removable protective cover strip (not shown) known in the self-adhesive art. peel off). The filter 18 is then attached to piece 33 such that the self-adhesive strip secures the filter 18.
When replacing the filter 18, grip it by the edges and peel the attachment from the piece 33. Then attach the new self-adhesive filter 18 to the piece 33.
In an alternative embodiment of the invention, the attachment attaches the piece 33 to the inside of the foam mask shell 11 and attaches the self-adhesive filter to the inside of the mask rather than to the outside of the mask.

When required, attachment piece 33 can be attached to both the inside and outside of the foam mask shell 11, and the attachment of both self-adhesive filters 17 and 18 can be done using piece 3.
Install it on 3. Thus, the mask 10 can be used to provide filtration for selective combinations of noxious and toxic gases, dust and mists.

In alternative embodiments, filters 17 and/or 18 are filters of the type known in the art.
It can be a cartridge.

In yet another embodiment, the filters 17 and/or 18 are permanently and directly attached to the foam mask shell 11 covering all the holes 12 by various techniques known in the art. I can do it.

FIG. 8 shows an embodiment of the invention having a foam mask shell 11. In FIG. At least one large hole 37 is drilled through the shell 11 and the collar 38
Through the wall of the shell 11 of the mask at 7, thermal bonding,
Friction snap fit or adhesive bonding. Alternatively, the large six 37 can be replaced with a suitably shaped permeability-forming cavity to accommodate a filter cartridge, for example one with multiple holes for air flow. The walls of such forming cavities are flat or corrugated (bellows) shaped. Alternatively, two holes or cavities 37;
There could be two colors 38, but only one is shown in FIG. 8 for ease of representation. Collar 38 may be cylindrical or pond-shaped, and a passageway or six 39 therethrough is used to mount a replaceable cartridge filter 40 of the type known in the art. Cartridge filter 40 has an enlarged portion 41 having an outer dimension essentially equal to the inner dimension of cylindrical passageway 39 through collar 38 . To install the cartridge filter 40, the extension 41 is connected to the passageway 3.
in which case it creates a relatively tight rsm fit holding the filter 40. Furthermore, no unwanted air will pass through this joint.To replace the cartridge filter 40, grasp it and twist it back and forth while pulling it away from the mask shell 11. After removing the cartridge filter, a new filter cartridge 40 is installed. There are many different types of filter cartridges that are interchangeable for use with the mask 10 of FIG. 8 in many types of environments. Alternatively, filter cartridge 40 can be permanently attached to mask shell 11 by a variety of methods known in the art. Foam shell masks are then replaced by more traditional forms of 'gas masks', which are cheaper, lighter and more comfortable to wear. Although inexpensive, such masks do not suffer from the attendant problems of mask handling and contagious disease concerns discussed above.

While what has been described above is a preferred embodiment of the invention, it will be apparent to those skilled in the art that numerous modifications can be made without departing from the spirit and scope of the invention. For example, elastic straps 13 and 14 are
By passing through the hole in the rim 15 of the mask,
It can be attached to the shell 11 of the mask.

The main features and aspects of the invention are as follows.

1. A respirator for filtering air, the shell being formed from a flexible, air-impermeable foam material and having one or more holes through its central portion; a respirator comprising: a first filter liner secured to and permeable through the holes that covers all of the holes and thereby filters the total amount of inhaled air passing through the holes;

2. The respiratory mask further comprises a retainer having a rim, the mask shell having a formed ridge surrounding the hole when the mask shell is formed, and the rim being pushed into the ridge. 2. The respiratory mask of claim 1, wherein the retainer and the first filter liner are both secured to the shell of the mask when the device is closed.

3. The method further comprises a one-way exhaust valve installed through the wall of the shell of the mask at a location not covered by the first filter liner and configured to exhaust exhaled air.
Respiratory mask as described in.

4. Attached to the edge of the shell of the mask and used to hold the respiratory mask over the nose and mouth of the mask wearer by passing it around the wearer's head; 1.
4. The respirator of claim 3, further comprising three or more elastic straps.

5. The respiratory mask further comprises a second filter liner that filters the air passing through the holes, the first filter liner being fixed to the inner side of the mask, and the second filter liner having: , fixed to the outside of the shell of the mask and covering all of the holes, thereby filtering all of the inhaled air passing through the holes.

6. further comprising a retainer attached to the shell of the mask over the first and second filter liners to secure both the first and second filter liners to the mask over the holes; 5. The respiratory mask as described in 5 above.

7. The foam mask shell has physical properties that give it shape retention and 1) conforms the edges of the mask shell to the wearer's face around the wearer's nose and mouth. 5. A respirator according to claim 4, which is made from a cross-linked closed-cell foam of a polymer having a resiliency that allows it to be sealed.

8. The respiratory mask according to 1 above, wherein the first filter liner comprises one or more layers including an r-conspiracy layer.

9. The respirator of claim 1, wherein the air impermeable foam material from which the respirator is made is a laminate structure.

10. An air-filtering respiratory mask, the shell of the mask being formed from a visible, air-impermeable foam material and having one or more holes through its central portion: fixed to the shell of the mask; a first attachment having an opening surrounding the hole; a first filter liner having an adhesive strip around the periphery to filter air passing through the hole; The attachment is used to secure the first filter liner to the respirator by being adhesively secured to the means, the first filter liner covering all of the holes, thereby Filtering all of the inhaled air passing through the holes.

11.1iif The respiratory mask of claim 10, further comprising a one-way exhaust valve mounted through the wall of the shell of the mask in a location not covered by the first filter liner and for exhausting exhaled air.

12, attached to the edge of the shell of the mask and used to hold the respiratory mask over the nose and mouth of the mask wearer by passing it around the wearer's head;
12. The respiratory mask of claim 11, further comprising one or more elastic straps.

13. The foam mask shell has physical properties that give it shape retention and that allow the edges of the mask shell to conform to the wearer's face around the wearer's nose and mouth. 13. A respirator according to claim 12, which is made from a cross-linked closed-cell foam of a polymer having a resiliency that allows it to be sealed.

14. said first attachment means is fixed on the outside of said mask; and further, said second attachment means is fixed on the inside of the shell of said mask and has an opening surrounding said hole; an adhesive strip around the periphery. a second filter line that filters air passing through the holes, wherein the adhesive strip
is used to secure the second filter liner to the respirator by being adhesively secured to the means, the second filter liner covering all of the holes, thereby 11. The respiratory mask according to item 10, further comprising: filtering all of the inhaled air passing through the holes.

15. The respiratory mask of claim 14, further comprising a one-way exhaust valve mounted through the wall of the mask shell at a location not covered by the first or second filter liner to exhaust exhaled air.

16, attached to the edge of the shell of the mask and used to hold the respiratory mask over the nose and mouth of the mask wearer by passing it around the wearer's head;
16. The respiratory mask of claim 15, further comprising one or more elastic straps.

17. The respirator of claim 10, wherein the air impermeable foam material from which the respirator is made is a laminate structure.

18. An air-filtering respiratory mask, comprising: a shell of the mask formed from a flexible, air-impermeable polymeric closed-cell foam and having one or more holes through a central portion thereof; The foam has physical properties that provide shape retention to the mask shell and resiliency that allows the edges of the mask shell to conform and seal to the wearer's face around the wearer's nose and mouth. a filter cartridge mounted over the apertures to thereby pass all inhaled air passing through the apertures;

19. During the formation of the shell of the mask, a recess is formed with the hole in the bottom thereof, the filter cartridge is attached to the recess by a force fit, and the recess is the recess in which the shell of the mask is formed; Due to the flexibility of the foam material, it expands and connects the sides of the recess and the filter.
18 above, where the contact between the cartridge and the cartridge is an airtight seal.
Respiratory mask as described in.

20. During the formation of the shell of the mask, a recess is formed in the bottom of which there is a Vt hole, and the filter cartridge is configured such that all the breathing air has to pass through the filter cartridge. 19. The respirator according to 18 above, wherein the recess is sealed.

21. The respiratory mask of claim 18, further comprising first attachment means secured to each of said holes and having an opening in which one of said filter cartridges is attached.

22. 1 above, further comprising a one-way exhaust valve installed through the wall of the mask to exhaust exhaled air.
8. The respiratory mask according to 8.

23, attached to the edge of the shell of the mask and used to hold the respiratory mask over the nose and mouth of the mask wearer by passing it around the wearer's head;
19. The respiratory mask of claim 18, further comprising one or more elastic straps.

24. The respiratory mask of claim 18, wherein the mask shell has at its edge a rearwardly projecting protrusion that adapts the edge of the mask shell to the face of the wearer of the mask.

25. An air-filtering respiratory mask made from a piece of fibrous material by forming it into a generally cup-shaped shell to fit over the mouth and nose of the mask wearer, through which the inhaled air passes. a filter liner fixed to the mask shell, not covering the edges of the mask, and generally conforming to the contours of the mask shell; and is impermeable to air flow in the region of the shell of the mask that contacts the face of the person and is not covered by the filter liner.

26. The respiratory mask of claim 25, further comprising a one-way exhaust valve mounted through the wall of the shell of the mask to exhaust exhaled air from inside the mask.

[Brief explanation of drawings]

FIG. 1 is a front view of a mask with one filter mounted inside the mask, the mask having holes through which inhaled air passes, an outlet valve for exhaled air, and a mask that holds the mask against the wearer's face; FIG. Shown with elastic straps. FIG. 2 is a side cross-sectional view of a mask with a filter attached to the front of the mask showing the exhaust valve for exhaled air and the elastic straps that hold the mask to the wearer's face. FIG. 3 is a side cross-sectional view of a mask with an inner and/or outer filter showing the orientation of the filter media mounted on the inside, the filter retainer, and the vent valve. FIG. 4 is an isometric cross-sectional view of a snap-on plastic retainer used to hold the filter inside the mask, with the filter attached inside. No. 4a1M, in a position inside the shell of the mask,
FIG. 5 is a cross-sectional view of the mask shell showing the snap-on retainer of FIG. 4; FIG. 5 is a layout diagram of a filter holder used in a mask having both an outer pre-filter and an inner post-filter. FIG. 6 is a diagram of the filter showing the various layers. FIG. 7 is a cross-sectional view of a foam shell mask with one filter replaceably attached to the outside of the mask by self-adhesive strips. FIG. 8 is a cross-sectional view of a foam shell mask using one or more filter cartridges removably clamped to the collar, with the collar mounted and clamped through the foam shell. 10... Respiratory mask 11... Shell 12... Hole 13.14... Strap 15... Rim 16... One-way discharge valve 17.18... Filter 19... Holder 20... Outer edge 21... Rib 22... Groove 23. ...Holding means 24,26...Pieces 25...Protrusions 27,28...Holes 32...Strips 33...・Installation is part 37.39...hole 38...color 40...cartridge filter

Claims (1)

Claims: 1. An air-filtering respiratory mask comprising: a shell of the mask formed from a flexible air-impermeable foam material and having one or more holes through a central portion thereof; fixed to the shell of the mask and covering all of the holes, thereby filtering all of the inhaled air passing through the holes;
a first filter liner that filters air passing through the hole. 2. A respirator for filtering air, the shell of the mask being formed from a flexible, air-impermeable foam material and having one or more holes through its central portion; fixed to the shell of the mask; , a first attachment means having an opening surrounding the hole; a first filter liner having an adhesive strip around the periphery to filter air passing through the hole; By being adhesively fixed to the attachment means of
used to secure the first filter liner to the respirator, the first filter liner covering all of the holes, thereby filtering all of the inhaled air passing through the holes; A respiratory mask comprising: 3. A respirator for filtering air, comprising: a shell of the mask formed from a flexible, air-impermeable polymeric closed-cell foam and having one or more holes through its central portion; the body has physical properties that provide shape retention to the mask shell and elasticity that allows the edges of the mask shell to conform and seal to the wearer's face around the wearer's nose and mouth; a filter cartridge mounted over the aperture to thereby filter all inhaled air passing through the aperture. 4. An air-filtering respiratory mask made from a piece of fibrous material by forming a generally cup-shaped shell to fit over the mouth and nose of the mask wearer, through which the inhaled air passes. a filter liner that is fixed to the mask shell, does not cover the edges of the mask, and generally conforms to the contours of the mask shell; and is impermeable to air flow in the region of the shell of the mask that contacts the face of the person and is not covered by the filter liner.