BLOWER FOR RESPIRATORY PROTECTIVE EQUIPMENT

A PAPR blower includes a frame comprised of three interconnected sections. A first flexible manifold connects between the first and second polygonal sections, and a second flexible manifold connects between the first and third polygonal sections. The second and third polygonal sections each include a respiratory filter. The first polygonal section comprises a vacuum motor and an outlet for filtered air. The vacuum motor generates a vacuum in the manifolds, thereby drawing ambient air into the respiratory filters and delivering filtered air from the respiratory filters, through the manifolds, and to the filtered air outlet. The blower may include an air delivery tube comprising a first end configured to be attached to the filtered air outlet and a second end configured to be attached to a breathing mask. The air delivery tube includes electrical wiring and a switch at the second end for controlling operation of the blower.

FIELD OF THE INVENTION

The present Application relates to the field of respiratory protective equipment, and more specifically, but not exclusively, to a blower for a powered air-purifying respirator (PAPR) that is structured ergonomically to enable comfortable wearing in multiple positions.

BACKGROUND OF THE INVENTION

Respiratory protective equipment enables its wearers to unrestrictedly breathe air, free of airborne noxious agents, while performing their intended tasks. Respiratory protective equipment may be worn, for example, firefighters, soldiers, or medical personnel.

An exemplary type of respiratory protective equipment is a powered air-purifying respirator (PAPR). A PAPR includes at least a blower unit, at least one filter, and a delivery tube. The blower unit draws air through the filter, which filters the air, and delivers filtered air through the delivery tube to an enclosed environment within a hood. A variety of PAPR units with these basic components are commercially available.

SUMMARY OF THE INVENTION

PAPR units suffer from various drawbacks which make them challenging to use. First, PAPR units may be uncomfortable to wear, especially for long periods of time, due to their weight and lack of symmetry. Second, there may be a reduced ability to hear when using a PAPR unit, due to noise from the blower motor. Moreover, it may be difficult to turn the blower off and on when the blower is worn on the back, due to lack of easy access to the switch.

It is an object of the present disclosure to overcome these and other drawbacks.

The present disclosure describes a PAPR blower with a novel ergonomic design. Specifically, the battery unit, blower, and filters are arranged on a frame having flexible manifolds connecting between the blower and the filters. When the blower is strapped to the body, the flexible manifolds adapt to the shape of the body to which the blower is attached. As a result, the blower may be worn comfortably on multiple regions of the body, including the upper back, lower back, and hip.

In addition, the present disclosure describes a PAPR blower with a novel air delivery tube. The air delivery tube includes electrical wiring therein and a switch for operating the PAPR blower near an outlet of the air delivery tube. As a result, the user may operate the blower using the switch located on the tube, which is easy to access at the user's neck, rather than having to reach behind his or her back to access a switch at the blower itself.

Furthermore, the present disclosure describes a PAPR blower with a novel mechanism for sound damping. The sound damping mechanism may include a damping ring arranged around a circumference of the blower as well as a damping disc arranged opposite a face of the blower. The sound damping mechanism both reduces the sound emanating from the blower as well as reduces the vibrations generated by the blower during operation.

According to a first aspect, a PAPR blower is disclosed. The blower includes a frame comprised of three interconnected sections, wherein a first flexible manifold connects between the first and second polygonal sections, and a second flexible manifold connects between the first and third polygonal sections. The second and third polygonal sections each include a respiratory filter. The first polygonal section comprises a vacuum motor and an outlet for filtered air. When the PAPR blower is in operation, the vacuum motor generates a vacuum in the manifolds, thereby drawing ambient air into the respiratory filters and delivering filtered air from the respiratory filters, through the manifolds, and to the filtered air outlet.

In another implementation, centers of the polygonal sections are arranged in a shape of an isosceles triangle, wherein the first polygonal section is arranged at an apex of the isosceles triangle, and the second and third polygonal sections are arranged at a base of the isosceles triangle.

In another implementation, the blower further includes a plurality of adjustable straps for attaching the PAPR blower to the user's body, and plurality of slots or buckles arranged around a perimeter of the frame, each slot configured to receive therein one or more of the straps.

Optionally, when the straps are arranged within the slots or buckles and tightened around a user's body, the flexible manifolds flex, thereby adapting the PAPR blower to contours of the user's body.

Optionally, the plurality of slots or buckles comprise at least: a plurality of upper slots or buckles at an upper edge of the first polygonal section; a plurality of upper lateral slots or buckles at lateral edges of the first polygonal section; and a plurality of lower lateral slots or buckles at lateral edges of the second and third polygonal sections.

Optionally, the straps are configurable in different orientations relative to the slots or buckles, for wearing of the PAPR blower on the user's back, waist, and thigh. Optionally, when the PAPR blower is worn on the user's back, a first strap is threaded through into the lower lateral slots or buckles and encircles the user's back, and a second strap is threaded through into the upper slots or buckles and reaches from the user's back to the user's chest. Optionally, when the PAPR blower is worn on the user's waist, a first strap is threaded into through the lower lateral slots or buckles and encircles the user's lower waist, and a second strap is threaded into the upper lateral slots or buckles and encircles the user's upper waist. Optionally, when the PAPR blower is worn on the user's thigh, a first strap is threaded through into the lower lateral slots or buckles and encircles the user's lower thigh, and a second strap is threaded into the upper lateral slots or buckles and encircles the user's waist.

In another implementation, the blower includes a removable battery receptacle configured to be attached to the vacuum motor at the first polygonal section. Optionally, the battery receptacle is removable from and replaceable onto the vacuum motor with a screwing motion, wherein the screwing motion effects both a physical and electrical connection. Optionally, the battery receptacle is attachable to an external face of the first polygonal section relative to the user's body. When the battery receptacle is attached to the first polygonal section, a mass of the PAPR blower is evenly distributed among the first, second, and third polygonal sections.

In another implementation, the blower includes an air delivery tube. The air delivery tube includes a first end configured to be attached to the filtered air outlet and a second end configured to be attached to a breathing mask. The air delivery tube comprises electrical wiring and a switch at or adjacent to the second end for controlling operation of the PAPR blower.

Optionally, the blower further includes electrical contacts and a mechanical connector configured on the first end, wherein the electrical contacts are arranged such that connection of the mechanical connector to the outlet for filtered air automatically connects the electrical contacts to corresponding electrical contacts at the outlet for filtered air.

Optionally, the electrical wiring is folded or coiled within the air delivery tube such that an expanded length of the electrical wiring is up to 40 50% greater than a length of the air delivery tube when the air delivery tube is not expanded.

In another implementation, the blower further includes a damping ring for damping noise and vibration, said damping ring configured between the vacuum motor and an external casing of the PAPR blower. Optionally, the damping ring includes a plurality of through holes and a plurality of ridges. Optionally, the damping ring is substantially cylindrical and is arranged circumferentially around the vacuum motor.

Optionally, the blower further includes at least one damping cylinder arranged opposite a face of the vacuum motor. Optionally, the damping cylinder includes a plurality of through holes, wherein the through holes have a diameter adapted to damp vibrations of a frequency generated by the vacuum motor based on Helmholtz resonance.

DETAILED DESCRIPTION OF THE INVENTION

The present Application relates to the field of respiratory protective equipment, and more specifically, but not exclusively, to a blower for a powered air-purifying respirator (PAPR) that is structured ergonomically to enable comfortable wearing in multiple positions.

Polygonal section11houses vacuum motor50. Vacuum motor50is powered by batteries in removable battery receptacle30, and turned on and off with switch40. Vacuum motor50has an outlet52for delivery of filtered air to an air delivery tube90(shown inFIGS.6,7, and8). Polygonal sections13a,13bhouse respiratory filters20a,20b. The respiratory filters20a,20bmay be, for example, CBRN filters.

Polygonal sections11,13a, and13bare joined by flexible manifolds16a,16b. Manifolds16a,16bare hollow and are configured to deliver filtered air therethrough, from the respiratory filters20a,20b, to the vacuum motor50. When the PAPR blower10is in operation, the vacuum motor50generates a vacuum in the manifolds, thereby drawing ambient air into the respiratory filters and delivering filtered air from the respiratory filters, through the manifolds, and to the filtered air outlet. The blower10is capable of delivering approximately 120 liters of filtered air per minute.

In the illustrated embodiments, the polygonal sections11,13a,13bare arranged substantially in the shape of an isosceles triangle. First polygonal section11is arranged at the apex of the triangle, and second and third polygonal sections13a,13bare arranged at the base of the isosceles triangle. Advantageously, the symmetric configuration of the polygonal sections enables the blower10to be mounted to the body in multiple configurations, as will be discussed further herein.

Referring toFIG.2, battery receptacle30is attachable to the first polygonal section11through operation of a screwing motion. Specifically, handhold32may be used to screw the battery receptacle onto threads34. The battery receptacle30further includes electrical contacts42which are adapted to form an electrical connection with corresponding electrical contacts44for the vacuum motor50. The screwing motion effects both a physical and electrical connection, such that, when the battery receptacle is fully threaded onto threads34, the electrical connection is completed without requiring any additional connection activity.

The batteries within battery receptacle30may be one or more single-use batteries. For example, battery receptacle30may contain eight AA batteries, which may support filtering operation for approximately 4 to 8 hours in a CBRN environment. Alternatively, the batteries may be one or more rechargeable batteries. For example, the batteries may be four 5.8V lithium batteries, which may support filtering operation for approximately 7-9 hours. Advantageously, the removable battery receptacle30allows external charging and the removal of a battery receptacle with an empty battery and its replacement with a full battery. In addition, the position of the battery receptacle30at an external face of the blower10(i.e., not adjacent to the user's body) allows for the battery to be replaced when the blower10is still adhered to the body, and allows the new batteries to be easily and safely screwed on.

When the battery receptacle30is attached to the first polygonal section11, a mass of the PAPR blower is evenly distributed among the first, second, and third polygonal sections. That is, a center of mass of the PAPR blower is at the centroid of the isosceles triangle defined by the vacuum motor50, respiratory filter20a, and respiratory filter20b. The resulting balancing of the mass of the PAPR blower10, in combination with the flexing of the manifolds16enables the blower to be situated comfortably at multiple locations on the body, without distancing any portion of the blower10from the body, thereby reducing shaking of the blower10and strain on the body.

FIGS.2and3show specifically the components that make up a flow path of filtered air between the respiratory filters20a,20band the vacuum motor50. Each polygonal section13a,13bincludes a receptacle14a,14bwith a back15a,15b, into which CBRN filter20a,20bis inserted. Specifically, each receptacle14a,14bhas a threaded ring18a,18btherein, for screwing therein a respective respiratory filter20a,20b. The threaded rings18may be compatible with a standard NATO RD40 connection. The connection between the receptacles14a,14band the respiratory filters20a,20bmay alternatively be accomplished through any other mechanism known to those of skill in the art. The cavity formed by receptacles14a,14band backs15a,15b, is fluidically connected to the corresponding manifold16a,16b. Optionally, receptacle14a,14band back15a,15bmay be formed integral with manifolds16a,16b, for example, through molding or additive manufacturing.

As seen inFIGS.1-4B, the blower10includes multiple slots for passing straps therethrough. The slots are mounted at various locations around the perimeter of each of the polygonal sections11,13a,13b. Specifically: slots62and63(collectively referred to herein as upper slots) are located at an upper edge of first polygonal section11; slots61and64(collectively referred to herein as upper lateral slots) are at the lateral edges of section11. Slots65and66are at the perimeter of receptacle14a, and slots67and68, are at the perimeter of receptacle14b. Slots65-68are collectively referred to herein as lower lateral slots.

In the illustrated embodiments, the slots are merely locations for the straps to pass through, and the straps are fastened through a conventional fastening mechanism along the straps themselves. In alternative configurations, the slots are formed as the latch of a buckle, with the straps including the tongue of the buckle.

When straps are inserted into one or more slots or buckles, and tightened against the body of the user, the manifolds16a,16bmay flex. This flexing of the manifolds16a,16bis counterbalanced by a spring force of springs69a,69b, which bias the manifolds16a,16bfrom the flexed position ofFIG.4Ato the straight position ofFIG.4B. The flexing of the manifolds16a,16badapts the PAPR blower10to contours of the user's body. Advantageously, the flexible3D design of the blower10allows the blower10to adjust to every curve and body structure of each user. The flexible design also provides shock and impact absorption.

FIGS.5A-5Cillustrate how straps82,84may be placed into different slots in order to enable different harnessing positions for blower10. As discussed above, although the description below is in reference to threading straps into slots, the same principles apply for threading straps into buckles (i.e., latching the end of the strap into the buckle).

In the view ofFIG.5A, the blower10is worn on the upper back. A first strap82is threaded into lower lateral slots65and67, and encircles the user's back. A second strap is threaded into upper slots62and63, and reaches from the user's back to the user's chest. Straps82,84meet in the region of the user's chest. Air delivery tube90extends from the blower10to the region of the user's mouth, over the user's shoulder.

In the view ofFIG.5B, the blower10is worn on the waist. First strap82is threaded into lower lateral slots65(not shown) and67, and encircles the user's lower waist. Second strap84is threaded into upper lateral slots61and64, and encircles the user's upper waist. Air delivery tube90extends from the blower10to the region of the user's mouth, over the user's shoulder.

In the view ofFIG.5C, the blower10is worn on the thigh. First strap82is threaded into lower lateral slots66(not shown) and68, and encircles the user's lower thigh. Second strap84is threaded into slots61and64and encircles the user's waist. Air delivery tube90extends from the blower10to the region of the user's mouth, in this case under the user's arm.

The ability to wear the blower10in three different positions represents a significant advance over known blowers, which are typically able to be worn only in one or two positions. Specifically, the user is able to adjust the location of the blower in response to different needs, such as a desire to situate the weight in a different location, or a desire to utilize different locations on the body for harnessing of other devices. Due to the flexing of the manifolds16a,16b, and springs69a,69b, as well as the symmetric orientation of the blower10the blower10adapts equally well to the different locations on which it is situated inFIGS.5A-5C.

Although the blower is illustrated as being in three specific locations in FIGS. it is evident that the blower may likewise be situated in different locations on the body, as desired. For example, the blower may alternatively be situated on the user's chest, or on the side of the user's waist. In each case, the symmetry and flexibility of the blower10enables the blower to be worn in comfort, as discussed.

FIGS.6-8illustrate aspects of the air delivery tube90in greater detail. Air delivery tube90is made of a flexible casing92. The flexible casing92may be made of any suitable flexible material, such as rubber. The casing92may be comprised of an inner layer and an outer layer, with one or more electric wires contained therebetween.

Air delivery tube90includes a proximal end91, with a mechanical connector56for a screw-based connection with the filtered air outlet52of the blower10, and a distal end93having a screw-based connector94for connection with a CBRN gas mask (not shown). The airflow connections between the tube90and the filtered air outlet52and the gas mask may be, for example, standard RD40 connections.

The gas mask may be any gas mask known to those of skill in the art. In one particularly advantageous example, the gas mask is equipped with an integrated interface platform for respiratory protective equipment. The integrated interface platform may include an air inlet interface, to which the distal end93connects, and may further include interfaces for air outlets, drinking, speech, and communication. An exemplary integrated interface platform is disclosed in Israeli patent application 289562, filed Jan. 2, 2022, entitled “A Platform For Respiratory Protective Equipment,” the contents of which are incorporated by reference as if fully set forth herein.

At the distal end93, on/off switch96may be used to control operation of the blower10. The external portion of the switch96is formed integrally with the outer layer of the air delivery tube90, as a result, the switch96and the tube90comprise a single unit. The switch96may alternatively be located on or at the connector94; when the connector94is attached to the tube90, the switch96and the tube90are united into a single device. Advantageously, switch96allows the user to control operation of the blower from a region around the user's neck, without contorting to access switch40, which would often be located behind the user's back.

At the proximal end91, air delivery tube90also forms an electrical connection with the vacuum motor50. End91includes a female connector end54, which includes recessed electrical contacts58. The electrical contacts58are connected to the wires within air delivery tube90. The outlet52of the vacuum motor50has a corresponding male connector end (not shown) with protruding electrical contacts (not shown). The mating of the connector ends is necessary in order to effect an airtight connection between outlet52and end91. Outlet52and end91may further include guides for assisting in the alignment of the male and female electrical connectors, and for permitting the mechanical connector56to close only when the connectors are properly aligned. When the electrical connectors are properly aligned, end91is properly lined up with outlet52, and mechanical connector56is properly screwed onto the threads of outlet52, an electrical connection is formed with the vacuum motor50.

Air delivery tube90is expandable and retractable. This expansion and retraction may be accomplished through stretching of the rubber or similar materials from which the air delivery tube90is made. Other mechanisms for expansion may similarly be used, as may be recognized by those of skill in the art. The elongation of the air delivery tube is useful in order to enable use of the air delivery tube90by users having different heights. The elongation is also useful for accommodating different mounting locations of the blower on the body. For example, a user requires a longer air delivery tube90when carrying the blower10on the thigh as compared to when carrying the blower10on the back. The ability to retract portions of the air delivery tube90ensures that the tube90does not flop around, which would potentially interfere with other activities being performed by the user.

The electrical wire within the air delivery tube90may be elongated or shortened by up to 50%. This elongation ensures that the wire will not be damaged when the tube90is expanded. This degree of expansion may be greater than the degree of expansion of the tube90itself. The expansion may be accomplished through one or more of the following techniques: 1) leaving extra length of wire in the interstitial space between the inner and outer layers; implementing at least a portion of the wire as a spiral wire that is inherently able to be stretched; or use of a spring mechanism that keeps the wire taut but permits expansion of the wire when desired.

FIGS.9and10A-10Ddepict various internal components of the vacuum motor and in particular a system that is used for damping noise and vibrations generated by the vacuum motor50.FIG.9illustrates an exploded view of the components of the first polygonal section11. From left to right, first polygonal section11includes battery connector32; battery receptacle30; frame12and flexible manifolds16; first damping cylinder74; vacuum motor damping ring70; second damping cylinder74and rear cover51of the vacuum motor50.

FIG.10AandFIG.10Bdisplay front and rear perspective views of the damping ring70. Damping ring70is made of a flexible polymer such as polyurethane, silicone, rubber, or another suitable shock-absorbing material. Ring70is sized to encircle the vacuum motor and performs at least the following functions. First, ring70fixes the location of the vacuum motor50between the frame12and the rear cover51, and thus prevents jiggling of the vacuum motor within the frame12. In addition, the through holes71and ridges72of the ring70absorb vibrations generated by the vacuum motor50. This, in turn, prevents transmission of sound waves from within the frame to outside the frame, and also prevents generation of echoes within the internal structure of the frame12. Simultaneously, the through holes71and ridges72provide passageways for the circulation of air within the internal space of the blower10.

In particular, the damping ring70reduces transmission of sound from the vacuum motor50to the exterior of the blower10based on general principles of sound attenuation, such as those that are used to measure Apparent Sound Transmission Class (ASTC). The principles of sound attenuation that are used to measure ASTC are explicated, inter alia, in ASTM Standard E336. The damping ring achieves this reduction in sound transmission, at least in part, through the asymmetry of the lattice structure of the through holes71, which causes sound to be trapped within the damping ring70. Preferably, a decibel level of the sound exiting the blower10is no greater than 50 dB.

FIG.10Cdisplays a perspective view of the damping cylinder74. Damping cylinder74may be made of the same materials as damping ring70. Damping cylinder74includes holes75. Similar to through holes71, holes75absorb shock and vibrations, and separate the vacuum motor50from the exterior of frame12, in order to prevent transmission of vibrations to the exterior and corresponding creation of sound waves. However, unlike damping ring70, which operates based on general sound damping principles, holes75have specific diameters which are used to dampen sound waves of specific frequencies that are generated by operation of the blower10. These diameters are calculated based on the resonance formula of a Helmholtz resonator. Specifically, holes75have the effect of suppressing the particular frequencies generated by the vacuum motor50, for example, during spinning of the vacuum motor to produce a vacuum. The efficacy of damping cylinder74with respect to the targeted frequencies may be measured with the Noise Reduction Coefficient (NRC).

The damping cylinders74also help fix the vacuum motor in place during assembly of the blower10. Together, the damping ring70and two damping cylinders74form a complete sound isolation structure, which encompasses the vacuum motor50entirely, except for the exit location of outlet52.

Optionally, damping cylinders74may include a spongy layer (not shown), for further absorptions of vibrations. In such embodiments, in order to enable operation of the Helmholtz resonance, the holes75are always oriented facing the vacuum motor50, while the spongy layer is located on an outer face of the damping cylinder, toward an exterior wall of the blower10.

FIG.10Dillustrates the damping ring70and damping cylinder74arranged around vacuum motor50. Outlet52is exposed for delivery of the filtered air to air delivery tube90.