Two-way protective respirator system with positive air flow against airborne contaminant particles and vapor components

Abstract

A portable two-way protective respirator system to be worn by a person that filters ambient air of harmful viruses, bacteria, and other airborne contaminant particles and vapor components for safe and fresh breathing by the wearer, while also removing any harmful viruses, bacteria, and other airborne contaminant particles and vapor components from the person's exhaled airstream before it is emitted to the surrounding community to protect other persons therein is provided according to the invention. The system comprises a respirator mask connected by a flexible hose to an air inflow blower fan unit containing filter media that produces an incoming airstream for a first chamber contained inside the respirator mask free of those harmful contaminant particles and vapor components. A gaiter made from finely woven cotton material extending from the bottom of the respirator mask defines a second chamber for a second airstream exhaled by the person to remove viruses and bacteria from that second airstream by a diffusion mechanism as it passes between the threads of the finely woven gaiter material. The two-way protective respirator system is comfortable for the person to wear, while being highly portable to accommodate a variety of work, educational, and lifestyle activities conducted within a group setting.

Claims

1. A two-way protective respirator system for removing harmful airborne contaminant particles and vapor components from ambient air breathed by a person wearing the respirator and biologic virus, bacteria, and other pathogen particles from air exhaled by the person from the respirator and emitted to persons within a group setting within the surrounding community, the two-way protective respirator system configured to communicate with a source of ambient air comprising: a respirator worn over the nose and mouth of the person and defining a first chamber, the respirator fitting closely to the face of the person to reduce leakage of ambient air into or out of the first chamber between the person's face and the respirator, the respirator having an inlet orifice and an outlet orifice; a blower fan for drawing the ambient air into a hose connected to the inlet orifice of the respirator to produce a first airflow stream under a positive pressure condition for delivery to the first chamber of the respirator; a filter unit operatively connected to the blower fan for removing harmful airborne contaminant particles or vapor components contained within the ambient air from the first airflow stream before it is delivered to the first chamber of the respirator; a gaiter made from woven fabric extending from the respirator and having lateral edges that lie against the chest of the person, a second chamber defined by the gaiter fabric and the person's chest; wherein the filter unit removes harmful airborne contaminant particles or vapor components contained within the ambient air that is delivered as the first airflow stream to the first chamber to protect the person breathing in the first airflow stream contained in the first chamber; and wherein an exhaled second airflow stream emitted by the person into the first chamber flows out through the outlet orifice of the respirator into the second chamber defined by the gaiter and the person's chest, submicron biologic virus, bacteria, and other pathogen particles contained within the exhaled second airflow stream clinging to neighboring fibers of the woven fabric of the gaiter to remove them by a diffusion separation mechanism before the resulting sanitized exhaled airflow stream exiting the gaiter enters the surrounding community to protect persons within the group setting from exposure to the virus, bacteria, and other pathogen contaminant particles.

2. The two-way protective respirator system of claim 1, wherein the volume of the second chamber is larger than the volume of the first chamber, so that the velocity of the airflow stream decreases as it travels from the first chamber to the second chamber to cause the lateral edges of the gaiter to lie against the chest of the person to produce a seal for the second chamber.

3. The two-way protective respirator system of claim 1, wherein the respirator is made from a solid shell of non-permeable material.

4. The two-way protective respirator system of claim 1, wherein the blower fan is a centrifugal blower fan.

5. The two-way protective respirator system of claim 1, wherein the first airflow stream produced by the blower fan is at about 13-40 cfm.

6. The two-way protective respirator system of claim 1, wherein the first airflow stream upon delivery to the respirator first chamber is at about 3-10 cfm.

7. The two-way protective respirator system of claim 1, wherein the filter unit comprises mechanical, physical, electrostatic, or lightwave means to remove the harmful airborne contaminant particles from the incoming ambient air.

8. The two-way protective respirator system of claim 7, wherein the filter unit comprises a HEPA filter.

9. The two-way protective respirator system of claim 7, wherein the filter unit comprises a ultraviolet light.

10. The two-way protective respirator system of claim 1, wherein the filter unit comprises activated carbon material for removing the harmful vapor components from the incoming ambient air.

11. The two-way protective respirator system of claim 10, wherein the filter unit comprises a NATO filter cartridge.

12. The two-way protective respirator system of claim 1, wherein the volume of the first chamber is about 5-10 in.sup.3.

13. The two-way protective respirator system of claim 1, wherein the volume of the second chamber is about 50-100 in.sup.3.

14. The two-way protective respirator system of claim 1, wherein the surface area of the gaiter is about 25-150 in.sup.2.

15. The two-way protective respirator system of claim 1, wherein the gaiter is made from high-thread count, finely woven fabric having about 200-600 threads per inch (TPI).

16. The two-way protective respirator system of claim 15, wherein the gaiter comprises two or more layers of the high-thread count, finely woven about 200-600 TPI fabric.

17. The two-way protective respirator system of claim 1, wherein the diameter of the outlet orifice of the mask is restricted to about 0.6 inches to create a slight back pressure condition inside the first chamber to keep the first airflow stream entering the first chamber separate from the moist, warmer exhaled second airflow stream exiting through the outlet orifice into the second chamber.

18. The two-way protective respirator system of claim 1, wherein if a person requires more than about 4 cfm of filtered air in the first airflow stream delivered to the first chamber of the respirator for proper breathing, the increased breathing of the person draws the volume of the exhaled second airflow stream contained in the second chamber back through the outlet orifice of the respirator into the first chamber to supplement the first airflow stream contained inside the first chamber for breathing by the person.

19. The two-way protective respirator system of claim 18, wherein ambient air is not drawn by the person's increased breathing level through gaps existing between the respirator and the person's face into the first chamber to expose the person to harmful airborne contaminant particles and vapor components contained in the ambient air.

20. The two-way protective respirator system of claim 1, wherein the temperature of the first airflow stream delivered to the first chamber of the respirator is reduced to make it more comfortable for the person to breathe.

21. The two-way protective respirator system of claim 1, wherein the humidity of the first airflow delivered to the first chamber of the respirator is controlled to make it more comfortable for the person to breathe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the accompanying drawings:

(2) FIG. 1 is a frontal perspective view of a person wearing the shoulder strap embodiment of the two-way protective respirator system of the present invention.

(3) FIG. 2 is a frontal perspective view of a person wearing the backpack embodiment of the two-way protective respirator system of the present invention.

(4) FIG. 3 is a side view of the person wearing the backpack embodiment of the two-way protective respirator system of FIG. 2.

(5) FIG. 4 is a rearward perspective view of the person wearing the backpack embodiment of the two-way protective respirator system of FIG. 2.

(6) FIG. 5 is a perspective view of the two-way protective respirator system of the present invention.

(7) FIG. 6 is a perspective view of the air intake and filtration module of the two-way protective respirator system in its closed position.

(8) FIG. 7 is an opposite perspective view of the air intake and filtration module of FIG. 6.

(9) FIG. 8 is a perspective view of the air intake and filtration module of FIG. 6 in its opened position.

(10) FIG. 9 is a frontal perspective view of the support frame and support bracket for the air intake and filtration module in their hingably-opened position.

(11) FIG. 10 is a rearward perspective view of the support frame and support bracket for the air intake and filtration module of FIG. 9.

(12) FIG. 11 is a perspective view of the battery pack for the air intake and filtration module.

(13) FIG. 12a is a frontal perspective view of the air intake blower fan unit with the filtration media removed.

(14) FIG. 12b is a perspective view of the face plate of the air intake blower fan unit of FIG. 12a.

(15) FIG. 13 is a rearward perspective view of the air intake blower fan unit of FIG. 12a disconnected from the support frame.

(16) FIGS. 14a and 14b are perspective views of the blower fan for the cooling blower fan unit.

(17) FIG. 15 is a top perspective view of the filter unit for the cooling blower fan unit.

(18) FIG. 16 is a bottom perspective view of the filter unit for the cooling blower fan unit of FIG. 15.

(19) FIG. 17 is a perspective view of the O-ring contained inside the assembled cooling blower fan unit.

(20) FIG. 18 is a perspective view of an alternative embodiment of the air intake blower fan unit with the NATO filter cartridge removed.

(21) FIG. 19 is a perspective view of the NATO filter cartridge.

(22) FIG. 20 is bottom perspective view of the NATO filter cartridge.

(23) FIG. 21 is a perspective view of an alternative NATO filter cartridge embodiment containing a HEPA filter and activated carbon.

(24) FIG. 22 is a perspective view of the respirator mask, flexible connector hose, and gaiter of the two-way protective respirator system of the present invention, showing the exterior of the respirator.

(25) FIG. 23 is perspective view of the respirator mask, flexible connector hose, and gaiter of the two-way protective respirator system, showing the interior of the respirtator.

(26) FIG. 24 is a frontal perspective view of the respirator mask.

(27) FIG. 25 is a schematic view of a person wearing the respirator and gaiter portions of the two-way protective respirator system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(28) A portable two-way protective respirator system to be worn by a person that provides inlet air to a first chamber contained in the respirator that is filtered of harmful viruses, bacteria, and other airborne contaminant particles and vapor components, for safe and fresh breathing for the wearer, and a second chamber off the first chamber that collects exhaled air from the wearer for separation of harmful viruses, bacteria, and other microorganisms contained therein by means of diffusion before they are transmitted to persons within the surrounding community is provided according to the invention. Such a portable mask system acts like a respirator to protect the wearer, while simultaneously serving as a mask to protect people within the surrounding community from harmful airborne contaminant particles, vapor components, and diseases. It also provides much-needed mobility to the person wearing the protective two-way protective respirator system for conducting work, educational, and lifestyle activities within group settings. The two-way protective respirator system can optionally condition the incoming filtered airstream to desired temperature and humidity level conditions in order to make the air more comfortable for the wearer to breathe.

(29) As used in this Application, harmful airborne contaminant particles and vapor components mean non-biologic particles made up of a variety of components, including acids (such as nitrates and sulfates), organic chemicals, metals, elements from the soil, dust, soot, and smoke, as well as gas vapor components like aldehydes, acid gases, sulfur dioxide, nitrogen oxides, polyacrylic aromatic hydrocarbons, benzene, toluene, styrene, metals, dioxins, ethylene oxide, formaldehyde, ammonium compounds, naphthalene, coke dust and sulfur, inorganic arsenic, cadmium, methylene chloride, chromium, 1,3-butadiene, and hydrogen sulfide. Airborne contaminant particles also include biologic particles like viruses, bacteria, pathogens, and other microorganisms that cause infections and diseases, all such contaminant particles and vapor components being capable of airborne transmission via droplets, aerosols, or solid particles that can be breathed by persons, or deposited onto hard surfaces that can be transmitted to other persons by means of surface contact.

(30) For purposes of this invention, group setting means two or more persons engaged in close proximity to each other in occupational, educational, recreational, cultural, commercial, or lifestyle tasks or activities pertinent to, without limitation, the meat packing, dental, front-line health care, retail store, grocery store, work office, home healthcare, assembly line, school, college or university, live sports, theater, concert, performing arts, drug development, or vaccine development industries, as well as normal daily tasks conducted by persons having compromised immune systems.

(31) As used in this application, surrounding community means other persons found within a work, educational, recreational, cultural, commercial, laboratory, or research environment who are positioned close enough to a person exhaling air to be exposed to the transmission of a harmful airborne contaminant particle or vapor component contained therein.

(32) The two-way protective respirator system 10 of the present invention is shown in FIGS. 1-4. As shown in a first embodiment depicted in FIG. 1, it comprises an air intake and filtration module 12 that is connected by means of flexible hose 14 to a respirator 16 that is secured by means of harness 18 to the wearer's (20) face 22, thereby covering the wearer's nose and mouth. Secured to the exterior surface of 24 of respirator 16 and extending downwardly in close proximity to the wearer's chest 24 is gaiter 26. The air intake and filtration module 12 may be conveniently worn and carried by the wearer 20 by means of strap 23 that can be secured around the wearer's shoulder or chest. In this manner, the two-way protective mask system 10 is portable, thereby providing much-needed mobility to a variety of work, educational, recreational, cultural, commercial, and day-to-day tasks of the wearer without impediment or discomfort.

(33) In an alternative second embodiment shown in FIGS. 2-4, the air intake and filtration module 12 may be contained inside a backpack 28 that is conveniently worn on the wearer's back 30 by means of straps 32. The hose 14 extends outside the backpack 28 to connect to respirator 16. Some persons may find it more comfortable to wear the air intake and filtration module 12 portion of the two-way protective respirator system 10 on the back, instead of suspended around the shoulder. Moreover, an upper zippered compartment 34 in backpack 28 provides the wearer storage space to carry additional personal items.

(34) The principal components of the two-way protective respirator system 10 are shown more clearly in FIG. 5 outside of backpack 28. The air intake and filtration module 12 is shown more specifically in FIG. 6-8. It comprises an intake air blower fan unit assembly 40, an airflow exit port tube 42, and a battery unit 44 for providing a ready source of electrical current to the cooling blower fan unit 40.

(35) The support frame 50 for the air intake and filtration module 12 is shown in FIGS. 9-10. It comprises a base plate 52 having four threaded holes 54 formed therein. Extending from one edge 56 of base plate 52 are a pair of lugs 58 having through bores 60 (not shown) formed therein along a common axis A-A. Extending from the opposite edge 62 of the base plate 52 are a second pair of lugs 64 having through bores 66 formed therein along a common axis B-B.

(36) The support frame 50 also comprises support bracket 70 comprising a central wall 72, two side walls 74 and 76 extending perpendicularly from the central wall, and foot support 78 extending perpendicularly from central wall 72. Central wall 72, side walls 74 and 76, and foot support 78 cooperate to form an interior volume V. This interior volume V is dimensioned to accommodate battery pack 80 shown in FIG. 11.

(37) Extending from edge 86 of support bracket side wall 76 is lug 88 having through bore 96 (not shown) formed therein. Extending from opposite edge 92 of support bracket side wall 74 is lug 94 having through bore 97 formed therein.

(38) Lug 88 of support bracket 70 is inserted in between lugs 58 of base plate 52 with the through bores 60 of lugs 58 and through bore 96 of lug 88 axially aligned. Bolt 100 is inserted through these through bores 60 and 96 of lugs 58 and 88, respectively, so that base plate 52 and support bracket 70 are hingably connected to each other. In this manner, the support bracket 70 containing battery pack 80 can be folded against base plate 52 to which the intake air blower fan unit 40 is attached to form the air intake and filtration module assembly 12, as shown in FIG. 7. Clip 102 is inserted through bores 97 and 66 of lugs 94 and 64, respectively, to secure the base plate 52 and support bracket 70 in this assembled manner.

(39) The intake air blower fan unit 40 is shown in greater detail in FIGS. 12a, 12b, and 13. It comprises housing 110 to which face plate 112 is secured by means of a plurality of bolts 114. Housing 110 comprises back wall 116 and side walls 118 defining an interior volume V.sub.2 of housing 110. An air intake blower fan 120 is inserted into interior volume V.sub.2 of housing 110.

(40) This air intake blower fan 120 is shown in greater detail in FIGS. 14a and 14b. It is preferably a centrifugal blower fan that pulls air in along axis C-C and pushes it out at a 90 angle along a second axis D-D. Suitable cooling blower fans may be sourced from Coultran Industrial Supply, Inc. of City of Industry, California. It should comprise a DC 12V fan unit operating its fan blades at a speed of about 3000-3200 rpm, and producing an outlet airflow of about 13-40 cfm. As shown in FIGS. 14a-14b, this air intake blower fan unit 120 has an inlet port 122 and in outlet port 124. A pair of wires 126 delivers electrical current to the fan unit. Air inflow enters fan 120 via inlet port 122 whereupon its velocity is increased to the about 13-40 cfm value.

(41) This processed air stream exits the fan 120 via outlet port 124, which is attached to exit port tube 42 attached to housing 110. This air stream will feel fresh to the wearer when it is delivered to respirator 16 for easier breathing.

(42) A plurality of threaded bores 128 formed around the perimeter of housing 110 (see FIG. 13) accommodate a plurality of bolts 130 that are used to secure cooling blower fan unit 40 to threaded apertures 54 of base plate 52 of support frame 50 (see FIG. 10).

(43) While the air intake blower fan unit 120 may preferably produce an airflow of about 12-40 cfm, this airflow will be reduced by the time that it travels through flexible hose 14 to respirator 16 (see FIG. 5). The airflow delivered to the nose cup in respirator 16 should be about 3-10 cfm, preferable about 4 cfm.

(44) A battery pack 80 is shown in FIG. 11 for providing a source of electrical current for the air intake blower fan unit 120. The battery pack comprises a housing 82 containing the battery cells. The battery cells may be alkaline or nickel cadmium, but they are preferably lithium ion battery cells. A conductor 84 extends from the exterior of the battery housing 82 to connector 85 at its distal end. A toggle switch 83 mounted on battery housing 82 permits the wearer to turn the battery pack 80 on or off. The connector 85 may be plugged into inlet 41 of cooling blower fan unit assembly 40 (see FIGS. 6-7 and 12). In this manner, electrical current can be delivered upon demand by battery pack 80 to air intake blower fan 120 in order to operate the air intake blower fan as described below. Meanwhile, interior volume V of support bracket 70 (see FIG. 9) is dimensioned to accommodate battery pack 80 so that it may be securely contained within the air intake blower fan unit assembly 40 of the two-way protective respirator system 10 of the present invention.

(45) FIGS. 12a and 12b show face plate 112 of air intake blower fan unit 40 in greater detail. Formed within base plate 112 is annular recess 140 comprising back wall 142 and circular side wall 144. A hole 146 is formed within back wall 142 within the central portion of base plate 112. A plurality of keys 148 extend from circular side wall 144 and annular channel 150 is formed within back wall 142 surrounding hole 146.

(46) Filter unit 160 is shown in greater detail in FIGS. 15-16. It is preferably round in shape, although other shapes like squares and rectangles also may be used. The filter unit 160 comprises a bottom annular wall 162, circular side wall 164 surrounding the bottom wall's perimeter, and top wall 166. Entrapped inside the interior volume V.sub.3 of this filter housing 166 formed by the bottom wall 162, side wall 164, and top wall 166 is a filtration media 168. A plurality of apertures 170 and 172 formed within top wall 166 and bottom wall 162, respectively allow atmospheric air to freely flow into and out of filtration media 168. A plurality of keys 174 extend from the perimeter of bottom wall 162 of the filter housing 166.

(47) The filtration media 168 may comprise any suitable mechanical, physical or electrostatic means for removing viruses, bacteria, and other undesirable airborne contaminant particles from the incoming airstream that enters the filtration media. Examples of such filtration media 168 include pleated hydrophobic filters, electrostatic filters that use static electricity to catch airborne contaminant particles as they pass through the filters media and activated carbon, as well as ultra violet light that may be cast upon microbial contaminants to kill the bacteria and viruses therein. Such filter media 168 should be capable of removing particles that are 0.1-1.0 m in size from the air stream, preferably particles below 0.3 m in diameter. The filter media 168 should preferably comprise a true High Efficiency Particulate Air (HEPA) filter that is capable of removing 99.7% or more of all particles that are 0.3 m or greater in diameter, or a medical-grade HEPA filter that can trap 99.95-99.995% of such particles.

(48) The filter unit 160 is secured to the face plate 112 of the cooling blower fan unit 40 by means of inserting it into the annular region defined by back wall 142 and circular side wall 144. The filter unit housing 166 is then rotated so that keys 174 extending outwardly from bottom wall 162 of filter housing 166 slide under and are entrapped by keys 148 extending inwardly from face plate 112 of air intake blower fan unit face plate 112 (see FIGS. 15 and 12b).

(49) A circular O-ring 180 shown in FIG. 17 may be inserted into annular channel 150 formed within back wall 142 of air intake blower fan face plate 112 (see FIG. 12b). O-ring 180 is therefore positioned between the bottom wall 162 of filter housing 166 and back wall 142 of face plate 112 to ensure that only air that passed through filtration media 168 may enter blower fan unit 40. In this manner, viruses, bacteria, and other airborne contaminant particles contained in the ambient air are reliably removed from the incoming air stream drawn into the air intake blower fan unit 40 for delivery though outlet tube 42 via flexible hose 14 to respirator 16 (see FIG. 5).

(50) The two-way protective respirator system 10 of the present invention may also be used to protect the wearer from vapor contaminants contained in the ambient air. For example, firefighters combatting large forest fires often must breath smoke that contains, in addition to carbon monoxide, carbon dioxide, and particulate matter like soot, dangerous organic vapors like aldehydes, acid gases, sulfur dioxide, nitrogen oxides, polyacrylic aromatic hydrocarbons, benzene, toluene, styrene, metals, and dioxins. Left untreated, these harmful vapor components can badly injure or kill the firefighters.

(51) Likewise, industrial plant workers can come into contact with a variety of dangerous fumes generated by the manufacturing processes, including or caused by the use of highly concentrated chemicals during production. Examples include ethylene oxide, formaldehyde, ammonium compounds, naphthalene, coke dust and sulfur, inorganic arsenic, cadmium, toluene, methylene chloride, chromium, benzene compounds, 1,3-butadiene and hydrogen sulfide. While manufacturing plants may be required to operate large filters to process the air containing these hazardous vapors and gases, employees may need additional protection.

(52) Thus, another embodiment 250 of the two-way protective respirator system of the present invention (see FIGS. 8-21) uses a NATO filter cartridge 252 in place of the pleated filtration media 168 shown in FIGS. 15-16. As shown in FIG. 18, air intake blower fan unit 254 is similar to the air intake blower fan unit 40 of FIG. 12 with the exception that face plate 256, which is secured to housing 110, comprises an outer ring wall 258 surrounding an annular region 260 further defined by inner ring wall 262. The inner ring wall 262 surrounds aperture 264 formed at the center of ace plate 256. The face plate wall around aperture 264 bears internal thread 266 (e.g., 40 mm threads).

(53) The NATO filter cartridges 252 shown in FIGS. 19-20 are available from a variety of suppliers like 3M Corp. of St. Paul, Minnesota They are designed to be used in gas masks worn by troops seconded to the North Atlantic Treaty Organization during battles and other hostile encounters. They comprise a housing 270 having an air inlet aperture 272 and an air outlet aperture 274 defined by annular wall 276 having external threads 278.

(54) The NATO filter cartridge 252 is mounted to face plate 256 of air intake blower fan unit 254 by means of seating its bottom surface inside annular region 260 with annular wall 276 extending therefrom inserted into aperture 264 of face plate 256 and the external threads 278 of annular wall 276 of the NATO filter cartridge 252 screwably engaging the internal threads 266 of the aperture 264 formed within the face plate. In this manner, all ambient air drawn by the air intake blower fan 120 will pass through inlet aperture 272 of NATO filter cartridge 252 and through the separation media 280 contained inside with the treated air stream passing through aperture 264 in face plate 256 into housing 110 of air intake blower fan unit 254, whereupon it can be delivered by flexible hose 14 to respirator 16 worn by the person 20.

(55) The separation media 280 contained inside housing 270 of the NATO filter cartridge 252 may comprise activated carbon which is useful for adsorbing chemical elements and compounds contained inside hazardous vapors and gases. Any filter cartridge holding a NBC rating (Nuclear, Biological, and Chemical) is suitable for purposes of the two-way protective respirator system 10 of the present invention. Suitable activated carbon-based NATO filter cartridges 252 may be sourced from 3M Corp.

(56) Even more advantageously, combination activated carbon/HEPA filter NATO filtration cartridges 280 (see FIG. 21) may be sourced from 3M Corp. Such cartridges 280 have a housing 282 with a top surface 284 featuring a plurality of inlet regions 286 for incoming ambient air. A HEPA filter 288 is contained within the top portion of housing 282 with a volume of activated carbon contained inside the lower portion. In this matter, ambient air drawn into combination NATO filter cartridge 280 will have airborne contaminant particles removed by means of the HEPA filter, while the activated carbon material then removes vapor and gas contaminants by means of adsorption. Thus, such a combination NATO filter cartridge can treat both harmful airborne contaminant particles and vapor and gas components contained within ambient air before it is delivered to respirator 16 to be breathed by the wearer of the respirator.

(57) The respirator 16 portion of the two-way protective respirator system 10 is depicted in greater detail in FIGS. 22-23. As shown in FIG. 23, it comprises respirator mask 190 featuring a shell 192 having a peripheral edge 194 around the circumference of the respirator mask that is properly shaped to the face of the wearer. In this way, the respirator mask 190 may be worn over the nose and mouth of the wearer, while preventing ambient air from leaking through the gap between the mask and face that is commonplace for prior art surgical masks. Such leakage would cause the wearer to breath in any viral, bacterial, or other airborne contaminant particles contained in the ambient air that would defeat the purpose of the two-way protective respirator system.

(58) The shell 192 portion of the respirator mask 190 may be made from separate front, side, and bottom panels, but it is preferably continuously shaped. The resulting three-dimensional structure provided by such front portion 196, side portions 198, and bottom portion 200 defines a chamber 202 referred to herein as the first chamber. This chamber has an open back side for accommodating the wearer's face. Straps or harness 18 attached to the side portions 198 of the respirator mask 190 secure the respirator mask in place with respect to the head of the wearer.

(59) Located in the front portion 196 of the respirator mask 190 is an inlet hole 206. A fitting 208 may be secured to this inlet hole 206 which is then attached to flexible hose 14 that in turn is secured to outlet pipe 42 of cooling blower fan unit 40 (see FIG. 5). In this manner, the incoming ambient air that is filtered by air intake blower fan unit 40 is delivered at a slightly elevated pressure of about 1.5-3 inches of water, preferably about 2 inches of water through flexible hose 14 through inlet hole 206 into first chamber 202 of respirator mask 190. The approximately 4 cfm of incoming air velocity is maintained above a zero value during the wearer's inhalation. This incoming processed air stream may be easily breathed by the wearer through his nose and mouth, while being protected from the viral, bacterial, and other harmful airborne contaminant particles and vapor/gas components contained in the ambient air that were entrapped by the filter media 160 or 252 contained inside the air intake blower fan unit 40.

(60) The nose cup shell 192 of respirator mask 190 should be produced from a non-permeable material like 70-90 durometer silicone elastomer. 80 Shore A elastomer is preferred. It is important that the nose cup shell be sufficiently elastomerically flexible, so that the peripheral edge 194 of the shell adheres closely to the contour of the face of the wearer to prevent leakage of unfiltered exhaled air escaping from the respirator mask 190 to the environment. Otherwise, the people in the surrounding community would be subject to breathing in the very viruses and bacteria that the two-way protective respirator system 10 of the present invention is designed to prevent.

(61) The volume of this first chamber 202 contained inside respirator mask 190 should be about 5-10 in.sup.3, preferably about 7 in.sup.3. Such an interior volume will accommodate an adequate supply of filtered air for the wearer of the mask 190 to breath.

(62) Thus, the respirator mask 190 of the present invention is different from prior art products available in the industry in that it does not contain one or two filter units directly attached to the respirator for filtering contaminant particles from the incoming air after it enters the mask. Instead, the filtration process occurs before the airstream enters the first chamber 202 inside respirator mask 190. Moreover, the continuous supply of fresh air into the respirator 16 will flush out high humidity and temperature conditions accumulated in the first chamber 202 caused by exhalation, thereby improving the comfort for the wearer who may have the respirator mask 190 secured to his face for a prolonged period of time.

(63) Flexible, corrugated CPAP hose 14 that delivers the filtered airflow from cooling blower fan unit 40 to first chamber 202 contained inside respirator mask 190 should be made from a suitably flexible material like polyvinyl chloride (PVC) to accommodate the movement of the wearer's body. It should be about 24-60 inches in length, preferably about 36 inches. It should also be about 0.5-1.5 inches ID in diameter, preferably about 0.8 inches ID. Such an appropriately sized flexible connector hose 14 will ensure that the airstream delivered by cooling blower fan unit 40 to first chamber 202 contained inside respirator mask 190 exhibits an average velocity of about 4 cfm for easy breathing by the wearer.

(64) The bottom portion 200 of respirator mask 190 features at least one outlet hole 210, preferably a plurality of outlet holes of at least three. Such outlet holes permit air exhaled by the wearer's mouth to readily exit first chamber 202 inside the respirator mask 190. This represents a departure from the standard N95 respirator used in the medical profession for which the wearer must exhale air through the N95 mask material which limits proper respiratory function, or the air is expelled directly through an exhalation valve mounted in the N95 respirator without diffusion filtering. After a few hours, tight-fitting N95 respirators have been found to reduce the amount of available oxygen by up to 20% for the wearer. The non-woven fabric material forming the body of the N95 respirator that blocks viral particles simultaneously restricts the inflow of ambient air containing oxygen necessary for breathing along with exhaled air that therefore builds up inside the N95 respirator.

(65) The outlet holes 210 contained within the bottom portion 200 of the respirator mask 190 of the present invention allows the exhaled air to enter a second chamber 214 defined by the bottom surface 200 of the respirator mask 190, the gaiter 26 of the two-way protective mask system 10, and the wearer's chest 24 (see FIG. 25). Gaiter 26 should be produced from two to three layers of high-thread count, fine-weave cotton or cotton/polyester blend fabric. Exemplary materials for gaiter 26 include broad cloth cotton, poplin, linen, flannel, tea towel, and sweatshirt fabric. The threads of this woven fabric should be characterized by about 200-600 threads per inch (TPI), preferable about 600 TPI. While too loose of a fabric weave will prevent the resulting apertures between the woven threads from filtering out the airborne contaminant particles, too tight of a fabric weave will cause a backup of exhaled air within second chamber 214, reduced respiratory function, and unwanted leakage of the air between respiratory mask 190 and gaiter 26 and the wearer's face and chest.

(66) Second chamber 214 should have a volume of about 50-100 in.sup.3, preferably about 75 in.sup.3. A surface area for gaiter 26 of about 25-150 in.sup.2, preferably about 80-100 in.sup.2, should be capable of producing this volume for second chamber 214. It is important that the volume of second chamber 214 is sufficiently greater than the volume of first chamber 202, so that the velocity of the airflow contained inside the first chamber decreases as it enters the second chamber 214 due to the increased volume of the second chamber with respect to the volume of the first chamber. This reduced velocity of the air flow exhaled by the wearer into the second chamber 214 will cause the natural resistance of the fabric of gaiter 26 to cause the gaiter to lie against the chest of the wearer to produce a relatively air-tight seal of the edges of the gaiter against the wearer's chest. Such a seal will cause the exhaled air to exit second chamber 214 through the apertures between the woven threads of the fabric for gaiter 26, instead of between the gaiter and the wearer's chest, in order to filter out larger airborne contaminant particles contained within the exhaled air. At the same time, the reduced velocity of the exhaled airflow contained inside second chamber 214 will allow the submicron virus particles contained in the exhaled air to cling to the neighboring fibers of the woven fabric of the gaiter 26 to be separated from the exhaled air exiting the second chamber by means of a diffusion separation mechanism. This lower exhaled air velocity inside second chamber 214 will increase the efficiency of this diffusion separation.

(67) Gaiter 26 may also include an elastic fabric back portion 27 that attaches it to head straps or harness 18 that surrounds the wearer's head (see FIG. 23). The forces exerted by these elastic fabric panels 27 help to pull the gaiter 26 against the wearer's chest to produce the necessary air-tight seal.

(68) The inlet orifice 206 formed within shell 192 of respirator mask 190 should be about 0.5-1 inch in diameter. The larger, the better for facilitating incoming filtered airflow. Meanwhile, the outlet orifices 210 should preferably be three in number at about 0.6 inches in diameter each. By restricting the size of these outlet orifices, a slight back pressure condition is created inside first chamber 202 inside the respirator mask to keep the cooled and filtered airflow entering the first chamber separate from the moist, warmer air exhaled by the wearer into the second chamber. This will improve the physical comfort of the wearer who can therefore wear the respirator mask 190 and utilize the two-way protective respirator system 10 of the present invention for a longer time period.

(69) While the number and size diameter of outlet apertures 210 in respirator mask 190 are important for creating the necessary slight back pressure condition in the first chamber to separate the warmer and moister exhaled air contained in the second chamber from the fresh incoming filtered airstream entering the first chamber, there are times when a back flow of air from the second chamber to the first chamber is desirable. First, a person undergoing physical exercises or other exertion will need more than 4 cfm of filtered air in the nose cone region of respirator mask 190. Prior art mask devices like surgical masks will allow the person undergoing heavy breathing to draw ambient air through the gaps between the mask and the face to satisfy this extra demand. However, such ambient airstream drawn through the gaps will not be filtered of harmful airborne contaminants. The resulting exposure to such harmful airborne particles and vapor components would defeat the purpose of the two-way protective respirator system 10 of the present invention.

(70) Second, as the filter media 168, 252 contained inside the air intake blower fan unit 120 becomes overloaded with entrapped airborne particles and vapor components, it will impede a desirable flow of filtered air through the filter media to the respirator mask 190. Such a reduced airflow may no longer meet the needs of a person at rest, and particularly a person undergoing strenuous exertion.

(71) Third, as the stored energy contained in battery pack 80 is reduced due to operation of the air intake blower fan unit 120, less filtered and conditioned airstream will be delivered to the respirator mask 190.

(72) But due to the novel design of the two-way protective respirator system 10 of the present invention that contains two separate air chambers, this problem is readily overcome. The second chamber defined by gaiter 26 and the wearer's chest is closely adjacent to the first chamber defined by the respirator mask 190 and the wearer's face. Only the bottom surface 200 of the respirator mask 190 separates the two chambers. Outlet apertures 210 allow for open communication between the air volume contained inside the two chambers. Thus, a person undergoing heavy exertion or otherwise needing an extra volume of incoming filtered airflow in the first chamber will breathe more deeply, thereby drawing a portion of the exhaled air contained inside the second chamber back through outlet apertures 210 to produce the necessary extra volume of air inside the first chamber for the person wearing the respirator mask 190 to breathe.

(73) While this volume of air drawn from the second chamber back into the first chamber may not be as fresh as the incoming airflow delivered by the air intake blower fan unit 120 to the first chamber, it is still breathable. It is also better than the wearer trying to draw unfiltered ambient air into the respirator mask 190's first chamber via any gaps between the respirator mask and the wearer's face. Moreover, any airborne contaminant particles or vapor components contained inside the second chamber that are drawn back into the first chamber will have been personally exhaled by the wearer, so they represent no new danger to the wearer.

(74) Furthermore, the wearer is likely to sense the existence of stale air in the first chamber. This will notify the wearer of the fact that the filter media contained inside the air intake blower fan unit 120 may need to be replaced, or to check whether battery pack 80 needs to be replaced or recharged.

(75) This feature that allows air contained inside the second chamber to be drawn back into the first chamber for breathing helps to mitigate the potentially adverse effect of a tight-fitting respirator mask. At the same time, because the availability of this back drafted air from the second chamber to the first chamber will reduce any drawing of ambient air through any gaps into the first chamber, there is less of a need for very tightly fitting the respirator mask to the wearer's face. This is particularly helpful for persons with facial hair. Standard N95 respirator masks prohibit facial hair that can impede a tight seal between the respirator mask and the person's face.

(76) In another embodiment of the two-way protective respirator system 10 of the present invention, the air intake blower fan unit 40 may be adapted to additionally treat the temperature and humidity levels of the incoming airstream. This may entail a small, portable thermoelectric cooler/heater unit. Such a unit should operate off of the electrical supply provided by battery 80. It should preferably be capable of cooling the filtered incoming airflow by up to 20 F., and heating the incoming airflow by up to 60 F. The thermoelectric-cooler/heater unit may be adjustable so that the wearer can define how much deviation he wants to produce from ambient temperate conditions. By cooling the temperature and removing any resulting condensed water in the airflow, the humidity level of that airflow may simultaneously be adjusted by the wearer for additional comfort.

(77) Once the incoming ambient air is drawn by the fan unit and passed through the filter media to remove harmful airborne particulates and vapor components, the resulting airstream is then passed through the thermoelectric-cooler/heater unit to adjust the temperature and humidity accordingly. Such temperature and humidity-controlled air stream will be more comfortable for inhalation when it is delivered to the respirator 16, 190.

(78) The above specification and accompanying drawings provide a complete description of the structure, components, and operation of the two-way protective respirator system of the present invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.