Modular, integrated powered air purifying respirator protector system

Abstract

To provide a modular, low profile PAPR system.SOLUTION: Disclosed is a modular, low profile PAPR system, the system including: a blower, a filter rail chassis 30 that is removably attachable to an inlet of the blower, and a hose system 100 that is removably attachable to the outlet of the blower. A battery pack 50 is attachable to the blower in a close, nested configuration abutting both the blower and the filter chassis 30, and may alternatively be carried remote from the blower with a power cord interconnecting the blower with the battery pack 50. The hose system 100 comprises an ovular outer tube, which maintains a generally flat profile for the hose as it extends across or along the operator's body. Two circular air carrying conduits are sealed within such ovular outer tube, thus providing a flat, small profile tube system that resists hoop stress applied to the outside of the hose.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 889,263, entitled "MODULAR INTEGRATED POWERED FILTRATION RESPIRATOR SYSTEM," filed August 20, 2019, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates generally to modular personal breathing apparatus, and more particularly to a modular compact powered air-purifying respirator (PAPR) system. [Background technology]

[0003] Powered air-purifying respirators (PAPRs) are commonly used by emergency responders and others working in hazardous environments, such as those contaminated by chemical, biological, radiological, or nuclear contaminants. Such systems typically include one or more filter cartridges and a blower unit for forcing air through a filter canister into a respirator or mask worn by the operator, thereby providing purified, breathable air to the operator. While generally effective in providing a safe, breathable environment for the operator, such systems are heavy and bulky, making them difficult and tiring to wear. Furthermore, the physical space occupied by the system's components can make it difficult for operators to use the system in tight, small, or other confined spaces. Furthermore, because operators with different mission objectives wear a variety of other equipment, a typical PAPR system may be unable to accommodate all of the other equipment they may wish to carry.

[0004] It would therefore be advantageous to provide a small, lightweight PAPR system that can be easily worn and carried by an operator and whose shape and general configuration can be easily customized to fit the space requirements on the operator's body. Summary of the Invention [Problem to be solved by the invention]

[0005] Disclosed herein is a modular, compact PAPR system. According to certain aspects of an exemplary embodiment, the system includes a blower, a filter rail chassis removably attachable to the blower inlet, and a hose system removably attachable to the blower outlet. The filter rail chassis has a low profile and may have one of several configurations, allowing for the attachment of, for example, one to three filter cartridges. To maintain the compactness of the system, the power source may be provided in a variety of configurations, including a removably attachable power source to the blower in a nested configuration adjacent to both the blower and the filter chassis, or alternatively, a battery pack carried remotely from the blower with a power cord interconnecting the blower and the battery pack. Furthermore, the power source may include a direct connection to an AC or DC power source. Such variable power and filter configurations provide users with the opportunity to quickly change the configuration of the PAPR, thereby allowing them to easily adapt to the particular environment in which they work (through controlling the air from the blower and the number of filters carried by the filter rail chassis). The hose system includes an oval-shaped outer tube extending from a first connector (attached to the blower) to a second, opposite end (attached to the operator's protective mask), the oval shape maintaining a generally flat profile for the hose as it extends across or along the operator's body. Two circular air-carrying conduits are sealed within the oval-shaped outer tube to prevent external contamination. This assembly results in a flat, compact tubing system. Despite its oval profile, the flat, compact tubing system maintains very high hoop stress due to the tubing system's inner circular tube, which provides low resistance to bending and intentional curving (as is desirable for routing the tubing system around other equipment worn by the operator), allowing it to bend around small radius bends without inadvertently kinking or sealing, thus resulting in a compact, non-collapsed hose system for conveying air from a remotely transported blower and filter assembly to the operator's protective mask.

[0006] According to certain aspects of embodiments of the present invention, a powered filtering respirator (PAPR) system includes: a blower unit having an air inlet and an air outlet configured to removably connect to a hose system for delivering purified air to a user; a filter rail chassis having a first closed end and a second open end and removably attached to the air inlet of the blower unit at the second open end; and a portable power assembly removably attached to the blower unit, wherein the filter rail chassis has at least one chassis inlet configured to removably and sealingly receive a filter canister, the portable power assembly having a bottom surface aligned with a bottom surface of the blower unit and a top surface at least partially positioned lower than a top of the at least one chassis inlet, the portable power assembly extending distally from a front of the blower unit to a point adjacent to a portion of the filter rail chassis.

[0007] According to another aspect of an embodiment of the present invention, a powered filtering respirator (PAPR) system includes: a blower unit having an air inlet and an air outlet configured to be removably connected to a hose system for delivering purified air to a user; a filter rail chassis having a first closed end and a second open end and removably attached to the air inlet of the blower unit at the second open end; a portable power assembly removably attached to the blower unit; and a hose system for delivering purified air to a user, the hose system having a hose inlet removably attached to the air outlet of the blower unit and a hose outlet configured to be attached to a user's safety mask, the filter rail chassis having at least one chassis inlet configured to removably and sealingly receive a filter canister, the hose system including two circular cross-section air delivery conduits extending between the hose inlet and the hose outlet, and an oval outer tube extending between the hose inlet and the hose outlet and surrounding the two circular cross-section air delivery conduits. [Brief explanation of the drawings]

[0008] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized. The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to like elements and in which:

[0009] [Figure 1A] FIG. 1 is a perspective view of a powered filtering respirator assembly according to certain aspects of an embodiment of the present invention. [Figure 1B] FIG. 1B is an enlarged view of a portion of the powered filtering respirator assembly of FIG. 1A showing the hose system connected to the blower unit. [Figure 2A] FIG. 1B is a front perspective view of a blower unit used in the powered filtering respirator assembly of FIG. 1A; [Figure 2B] FIG. 2B is a rear view of the blower unit of FIG. 2A. [Figure 2C] FIG. 2B is a front view of the blower unit of FIG. 2A. [Figure 3] FIG. 1B is a front perspective view of a filter rail chassis used in the powered filtering respirator assembly of FIG. 1A. [Figure 4A] FIG. 1B is a top view of the powered filtering respirator assembly of FIG. 1A with the filter rail chassis installed and the blower cover removed for clarity. [Figure 4B] FIG. 1B is a top view of the powered filtering respirator assembly of FIG. 1A without the filter canister and with the blower cover removed for clarity. [Figure 5A] FIG. 1B is a front perspective view of a power unit used in the powered filtering respirator assembly of FIG. 1A; [Figure 5B] FIG. 5B is a perspective view of the power supply unit of FIG. 5A as seen from the rear. [Figure 6] FIG. 10 is a front perspective view of a blower and power supply unit according to another aspect of an embodiment of the present invention. [Figure 7] FIG. 10 is a front perspective view of a powered filtering respirator assembly according to another aspect of an embodiment of the present invention. [Figure 8] 1 is a diagram of a pouch for remote storage of a power supply unit in accordance with certain aspects of an embodiment of the present invention. [Figure 9] FIG. 1B is a perspective view of a hose system used with the powered filtering respirator assembly of FIG. 1A; [Figure 10] FIG. 10 is an enlarged partial cross-sectional view of a portion of the hose system of FIG. [Figure 11] 10 is an exploded view of the inlet and outlet ends of the hose system of FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be understood by reference to the following description and the accompanying drawings. The description of the embodiments set forth below so that one can practice the invention is not intended to limit the scope of the preferred embodiments, but is provided as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.

[0011] For the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted. The terms used herein are used only for the purpose of describing particular embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. Furthermore, the use of terms such as "a" and "an" does not denote a limitation of quantity, but rather denotes the presence of at least one of the referenced item.

[0012] The use of terms such as "first" and "second" does not imply a particular order, but rather is used to identify particular elements. Furthermore, terms such as "first" and "second" do not indicate an order of importance, and terms such as "first" and "second" are used to distinguish one element from another. Furthermore, it should be understood that the terms "comprise" and / or "comprising" or "include" and / or "including," as used herein, specify the presence of any one of the stated features, regions, integers, steps, operations, elements, and components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and groups thereof.

[0013] Although some features are described with respect to individual exemplary embodiments, aspects of the invention need not be limited thereto, as features from one or more exemplary embodiments may be combined with other features from one or more embodiments.

[0014] 1A and 1B, according to certain aspects of one embodiment, a modular integrated powered filtering respirator ("PAPR") system is provided having a blower unit 10, a filter rail chassis 30 configured to receive a filter canister 36, such as a CBRN filter canister, a power assembly 50 that powers the blower unit 10, and a hose assembly 100 that interconnects the blower unit 10 to a protective mask.

[0015] 1A-4B, blower unit 10 has an inlet port 12 that receives outlet end 32 of filter rail chassis 30 in an airtight connection. Blower unit 10 has a motor that operates fan 11 (FIGS. 4A-4B) that draws air through filter rail chassis 30, outward through outlet end 32 of filter rail chassis 30, and into inlet port 12 of blower unit 10. Filter rail chassis 30 has one or more filter canister ports 34. Each of one or more filter canister ports 34 may removably receive a filter canister 36, such as a CBRN filter canister having a configuration known to those skilled in the art. When blower unit 10 operates, air is drawn through filter canister 36 and into filter canister port 34, during which the process air is purified of contaminants.

[0016] The purified air then travels from filter canister port 34 through the body of filter rail chassis 30 towards blower unit 10, into inlet port 12 of blower unit 10, out outlet port 14, into hose assembly 100 and finally to the operator's protective mask.

[0017] The filter rail chassis 30 has a slim body configuration such that the width of the filter rail chassis 30 does not extend outside the diameter of the filter canister 36. The outlet end 32 of the filter rail chassis 30 has a width complementary to the width of the inlet port 12 of the blower unit 10, while the more distal portion of the filter rail chassis 30 may have a slimmer profile to further minimize handling loads and shocks on the operator. Additionally, the filter rail chassis 30 may be equipped with three or more filter canister ports 34, two filter canister ports 34, or one filter canister port 34, allowing the operator to select the configuration that best suits the work environment while minimizing the profile of the filter rail chassis 30 and maximizing the ability to adapt the system to current work needs. Because the filter rail chassis 30 is removable from the blower unit 10, the modular system allows the operator to select the appropriate size filter rail chassis 30 (i.e., one filter, two filters, three filters, etc.) for each mission. Preferably, the outlet end 32 of the filter rail chassis 30 may removably receive a clip 32a to retain the filter rail chassis 30 on the inlet 12 of the blower unit 10. This clip 32a may be manually removable when desired (e.g., when changing the filter rail chassis 30 from a two filter configuration to a three filter configuration or a one filter configuration).

[0018] To help maintain a compact profile, the blower unit 10 may have a recessed wall 16 that faces the filter canister 36 when mounted to the filter rail chassis 30. Preferably, the recessed wall 16 has a curvature that generally matches the curvature of the outer wall of the filter canister 36, such that the filter canister 36 closest to the blower unit 10 is positioned closer to the blower unit 10 than if the wall 16 had a flat configuration. The blower unit 10 has a front wall 18 that carries the outlet port 14, an operating switch 19 for an operator to adjust the speed of the blower motor, and preferably a smart remote switch connection 20 that allows connection of a smart remote switch (SRS) 120 on a hose assembly 100, as described in more detail below.

[0019] According to certain aspects of the embodiment, and with particular reference to FIGS. 1A and 1B, the SRS may be provided in one of two configurations: a stand-alone configuration or a hose-integrated configuration. In the stand-alone configuration, the SRS is contained in its own housing connected to the SRS connection 20 on the blower unit 10. In the hose-integrated configuration, the SRS 120 is fixed to the hose assembly 100. The SRS 120 therefore functions through two switches: an on-board switch or a remote switch. Preferably, when the remote switch is used, the on-board switch cannot be used. In the hose-integrated configuration using a remote switch, the SRS 120 may comprise a two-position switch located at the end of the hose assembly 100 that attaches to the operator's mask, allowing for easy and quick operator access. The remote SRS 120 may preferably have an "off" position comprised of a position where a firm tactile sensation (snap) is maintained and an "on / set" position comprised of a tactile momentary position. When set to "off," the PAPR is off. The first time the operator presses "On / Set" from the "Off" position, the PAPR will go to the programmed setting, <Setting 1> or <Last> (see Program Selection description below); similarly, each time "On / Set" is pressed, the PAPR will go to the next programmed setting, <Setting X>.

[0020] Thus, as a non-limiting example, starting from the "Off" position, if "On / Set" is pressed three times, the PAPR will operate at the speed programmed in <Setting 3>.

[0021] Optionally, additional functionality may be incorporated into the SRS assembly, such as indicators that provide visual signals indicating system conditions such as (by way of non-limiting example) low current or current flow, low battery or overall battery condition.

[0022] Similarly, the manual on-board blower / filter rail switch 19 may comprise a rotary selector providing four position settings, such as, by way of non-limiting example, "Off," "Setting 1," "Setting 2," and "Setting 3" (each setting representing a different operating speed or operating state of the blower unit 10 and identical to a state programmed in the remote SRS 120).

[0023] According to certain aspects of specific embodiments, the system allows an operator to define the number of speed settings and their respective functions / flow rates that can be achieved by the blower unit 10. Such programming may be performed through the SRS connection 20 using a personal computer system (PC) or other computing device connected to the SRS connection 20. In certain configurations, the PC or other computing device may include software that allows each <<setting>> to be programmed, preferably to one of the following exemplary settings: (i) a constant flow rate with a range defined by a blower operating window for a given number of filter canisters 36; or (ii) a BRP (breathing rate response) defined by the number of filter canisters 36 and available as an offset from the default parameters used to increase flow levels across the BRP curve.

[0024] The PC or other computing device may include software that allows for the "initial on / off" setting to be set either starting from <setting 1> or starting from the last setting used before "off." Additionally, the PC or other computing device may include software that allows for cycling after the last setting. For example, if four settings are programmed, after pressing on / set four times, the unit will do nothing on the fifth press, regardless of the number of times on / set is pressed, as shown below: [Table 1] Alternatively, the unit may cycle back, and on the fifth press the unit may cycle back to <Setting 3>, cycling as follows: [Table 2]

[0025] 5A-7, the modular integrated PAPR system may include a power supply assembly 50 for powering the blower unit 10. For a specific embodiment, the power supply assembly 50 may include a battery pack mounted, e.g., removably mounted, to the housing of the blower unit 10. In this regard, the battery pack 50 may have an inner wall 52 that conforms to the outer shape of the housing of the blower unit 10 and at least a portion of the outer edge of the filter rail chassis 30. More specifically, a first portion of the inner wall 52 may be flat to conform to a side wall portion of the housing of the blower unit 10 with at least a portion of the battery pack disposed below the housing of the blower unit 10.

[0026] The battery pack 50 preferably has a pin assembly 54 that connects to the power port 22 on the blower unit 10, thereby enabling the pin assembly 54 to engage a power circuit internal to the blower unit 10 and power the blower motor. Optionally, a battery pack adapter 60 may be disposed in series between the battery pack 50 and the battery port 22 on the blower unit 10. Use of the battery pack adapter 60 in this manner allows the battery pack 50 to be quickly replaced with another when it is depleted, without having to manipulate the battery pack 50 when attaching it to the blower unit 10. A cable 62 may removably receive the pins 54 of the battery pack 50, thereby allowing one battery pack 50 to be quickly connected or disconnected from another. Similarly, the cable 62 allows an operator to carry the battery pack 50 on their body, separate from the blower unit 10 and filter rail chassis 30, thus further providing the operator with an opportunity to minimize the profile of the blower unit 10 and filter rail chassis 30. The battery pack adapter 60 has pins 64 that are generally identical to the pins 54 on the battery pack 50 and that similarly mate with the power port 22 on the blower unit 10 .

[0027] Additionally, the battery pack 50 may optionally have a detachable cable 70 (shown in FIG. 7 ) that allows the battery pack 50 to be connected to a power source, such as an AC or DC power source, for purposes of both charging the battery pack 50 and directly powering the blower unit 10. Alternatively, the battery pack 50 may be hardwired to such a power cable 70. The battery pack 50 may be configured to transfer external power to the blower unit 10 when connected to the external power source, and to automatically switch to battery power when the external power source is disconnected.

[0028] Additionally, while the battery pack 50 is removable from the blower unit 10, it may have removable fasteners, such as screws or bolts, that hold the battery pack 50 in the housing of the blower unit 10 and ensure a secure connection between these elements. In a particularly preferred configuration, the top of the battery pack 50 may include guide rails 53 that engage push latches 17 on the underside of the housing of the blower unit 10. This allows the battery pack 50 to slide and click into position on the underside of the housing of the blower unit 10, holding it in place while allowing a user to press the push latches 17 downward and slide the battery pack 50 outward along the guide rails 53 for eventual removal from the blower unit 10.

[0029] In either of the above cases, the battery pack 50 may be removable from the blower unit 10 and may be carried by the operator in a pouch 80 (shown in FIG. 8) or the like separate from the blower unit 10 and filter rail chassis 30.

[0030] As noted above, with particular reference to Figures 9-11, hose system 100 provides a conduit for breathable air from blower unit 10 to a connection port on an operator's protective mask. Hose system 100 includes a first end 101 configured for connection to outlet port 14 on blower unit 10 and a second end 102 configured for connection to an inlet port on the exterior of the operator's protective mask. More specifically, first end 101 includes a rotatable coupling 103 that forms a straight-line connection with outlet port 14 on blower unit 10. Similarly, second end 102 includes a rotatable coupling 104 that carries outlet 105, which provides a 90-degree connection from hose system 100 to the operator's protective mask, to minimize the profile of the modular, integrated PAPR system. First flexible cuff 106, which in an exemplary embodiment may be made from rubber, and similarly configured second flexible cuff 107 fit securely onto tapered portions of rotatable coupling 103 and rotatable coupling 104, respectively, which are inserted within outer tube 110. Preferably, outer tube 110 is welded to each of rubber cuffs 106 and 107 to ensure an airtight connection.

[0031] The outer tube 110 is made of a material thick enough to protect against tearing while being flexible enough to allow the operator to position and route the outer tube 110 in the most desirable configuration for a given device configuration. The outer tube 110 is oval-shaped, which maintains the small, flat profile of the hose system 100 so that the outer tube 110 lies flat against the operator's body in the intended position and location without rolling and interfering with other operators' use of the wearable equipment. In certain exemplary configurations, the outer tube 110 may be formed from a heavy-duty nylon, such as CORDURA® or NOMEX®, by way of non-limiting example. The outer tube 110 may alternatively be formed from other abuse-protective, flexible materials, such as KEVLAR® or materials of similar configuration. The outer surface of the outer tube 110 is preferably welded to the inner surfaces of the rubber cuffs 106 and 107, respectively.

[0032] Preferably, two air carrying conduits 120 having circular cross sections are disposed within the outer tube 110 to carry filtered air from the blower unit 10 to an air inlet provided in the operator's protective mask. The circular air carrying conduits 120 may include a reinforcing coil 122 extending around the circumference of each conduit 120 to provide crush resistance for each individual conduit 120, such as when the outer tube 110 is inadvertently compressed by other equipment carried by the operator. Furthermore, providing two such circular air carrying conduits 120 imparts a much higher hoop stress to the entire hose system 100 than if the entire hose system 100 were simply hollow and oval. Thus, such an assembly of an oval outer tube 110 with circular air carrying conduits 120 therein allows for a flat, low-profile outer hose system that can rest against the operator's body. Such an assembly helps reduce the overall profile of the hose system 100 while still ensuring protection against inadvertent kinking or occlusion of the air carrying conduits. Still, providing two internal circular air carrying conduits provides lower bending resistance than providing one large circular conduit, thereby allowing the operator to route the hose system 100 on his or her body in a manner that is most appropriate and comfortable for a given equipment payload. In an exemplary configuration, each of the air carrying conduits 120 preferably has an outer diameter of about 14 mm to 24 mm, and more preferably has an outer diameter of about 19 mm and a length of about 36 inches.

[0033] Each end of each air carrying conduit 120 is received in a fitting 130. Each fitting 130 is configured to transfer air between the two air carrying conduits 120 and one of the first end 101 and second end 102 of the hose system 100. The outer wall of each fitting 130 is sized to fit snugly inside the respective inner ends of the 90-degree connections of the rotatable coupling 103 (at the first end 101 of the hose system 100) and the rotatable coupling 104. The outer wall of each fitting 130 may further comprise one or more sealing members, such as gaskets or O-rings, to provide a liquid-tight and air-tight seal. In a particularly preferred configuration, a CBRN protective barrier sleeve 140 surrounds both air carrying conduits 120, further protecting the air carried by the air carrying conduits 120 from contamination by harmful elements external to the hose system 100. In such a configuration, a CBRN protective barrier 140 seals each fitting 130 at each inner end of each fitting 130. CBRN protective barrier 140 may be formed from GORE-TEX® in certain exemplary embodiments, although a variety of other flexible CBRN protective materials may be used as well.

[0034] While preferred embodiments and certain modifications of the concepts underlying the present invention have been fully described, various other embodiments, as well as certain variations and modifications of the embodiments shown and described herein, will be apparent to those skilled in the art once the underlying concepts described above are fully understood. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein.

Claims

1. a blower unit having an air inlet and an air outlet configured to removably connect to a hose system for delivering purified air to a user; a filter rail chassis having a first closed end and a second open end, the filter rail chassis being removably attached to the air inlet of the blower unit at the second open end; a portable power supply assembly removably attached to said blower unit; Equipped with the filter rail chassis having at least one chassis inlet configured to removably and sealingly receive a filter canister; The portable power assembly includes: a bottom surface aligned with the bottom surface of the blower unit; a top surface at least a portion of which is positioned lower than the top of the at least one chassis inlet; and The powered filtering respirator assembly, wherein the portable power supply assembly extends distally from a front of the blower unit to a point adjacent a portion of the filter rail chassis.

2. a filter canister attached to the at least one chassis inlet; 10. The powered filtering respirator assembly of claim 1, wherein the filter rail chassis has a width dimension that is less than an outer diameter of the filter canister.

3. 3. The powered filtering respirator assembly of claim 2, wherein the filter rail chassis has a height dimension that is less than a width dimension of the filter rail chassis.

4. 3. The powered filtering respirator assembly of claim 2, wherein the air inlet of the blower unit is located in a rear wall of the blower unit, the rear wall of the blower unit including a recess having a radius of curvature that matches a radius of curvature of the outer diameter of the filter canister.

5. 10. The powered filtering respirator assembly of claim 1, wherein the blower unit further comprises a smart remote switch connection port.

6. 6. The powered filtering respirator assembly of claim 5, further comprising a smart remote switch removably connected to the smart remote switch connection port.

7. a hose system for delivering purified air to a user, the hose system having a hose inlet removably attached to the air outlet of the blower unit and a hose outlet configured to be attached to a safety mask of the user; 7. The powered filtering respirator assembly of claim 6, wherein the smart remote switch actuator is fixed to the hose system.

8. 8. The powered filtering respirator assembly of claim 7, wherein the actuator of the smart remote switch is adjacent to the hose outlet.

9. 10. The powered filtering respirator assembly of claim 1, further comprising a hose system having a hose inlet removably attached to the air outlet of the blower unit and a hose outlet configured to attach to a user's safety mask, the hose system delivering purified air to a user.

10. The hose system comprises: two circular cross-section air conveying conduits extending between the hose inlet and the hose outlet; an oval outer tube extending between said hose inlet and said hose outlet and surrounding said two circular cross-section air conveying conduits; 10. The powered filtering respirator assembly of claim 9, further comprising:

11. the hose inlet further comprises a first rotatable coupling; the hose outlet further comprises a second rotatable coupling; The hose system comprises: a first flexible cuff having a first cuff inner surface and secured to the first rotatable coupling; a second flexible cuff having a second cuff inner surface and secured to the second rotatable coupling; Further provided with a first end of the oval outer tube welded to the first cuff inner surface; 11. The powered filtering respirator assembly of claim 10, wherein a second end of the oval outer tube is welded to the second cuff interior surface.

12. 11. The powered filtering respirator assembly of claim 10, further comprising a CBRN protective barrier tube surrounding the two circular cross-section air carrying conduits between the two circular cross-section air carrying conduits and the oval outer tube.

13. a first fitting insertable into the first rotatable coupling to form the first fluid-tight and gas-tight seal, the first fitting receiving a first end of each of the two circular cross-section air conveying conduits; a second fitting insertable into the second rotatable coupling to form the second fluid-tight and gas-tight seal and adapted to receive second ends of the two circular cross-section air conveying conduits; 13. The powered filtering respirator assembly of claim 12, comprising:

14. the portable power assembly is connectable to a power port of the blower unit; The portable power assembly includes: a battery pack adapter connectable to the power port of the blower unit; a power cable secured to the battery pack adapter and connectable to the portable power assembly; 10. The powered filtering respirator assembly of claim 1, further comprising:

15. a blower unit having an air inlet and an air outlet configured to removably connect to a hose system for delivering purified air to a user; a filter rail chassis having a first closed end and a second open end, the filter rail chassis being removably attached to the air inlet of the blower unit at the second open end; a portable power supply assembly removably attached to the blower unit; a hose system for delivering purified air to a user, the hose system having a hose inlet removably attached to the air outlet of the blower unit and a hose outlet configured to be attached to a safety mask of the user; Equipped with the filter rail chassis having at least one chassis inlet configured to removably and sealingly receive a filter canister; The hose system comprises: two circular cross-section air conveying conduits extending between the hose inlet and the hose outlet; an oval outer tube extending between said hose inlet and said hose outlet and surrounding said two circular cross-section air conveying conduits; 1. A powered filtering respirator assembly comprising:

16. the hose inlet further comprises a first rotatable coupling; the hose outlet further comprises a second rotatable coupling; The hose system comprises: a first flexible cuff having a first cuff inner surface and secured to the first rotatable coupling; a second flexible cuff having a second cuff inner surface and secured to the second rotatable coupling; Further provided with a first end of the oval outer tube welded to the first cuff inner surface; 16. The powered filtering respirator assembly of claim 15, wherein a second end of the oval outer tube is welded to the second cuff interior surface.

17. 16. The powered filtering respirator assembly of claim 15, further comprising a CBRN protective barrier tube surrounding the two circular cross-section air carrying conduits between the two circular cross-section air carrying conduits and the oval outer tube.

18. a first connecting member insertable into the first rotatable coupling to form the first fluid-tight and gas-tight seal, the first connecting member receiving a first end of each of the two circular cross-section air conveying conduits; a second connecting member insertable into the second rotatable coupling to form the second fluid-tight and gas-tight seal and adapted to receive second ends of the two circular cross-section air conveying conduits; 20. The powered filtering respirator assembly of claim 17, comprising:

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