Waste Receptacle and Vacuum Cleaner

This application is a continuation of U.S. patent application Ser. No. 18/875,447, filed Dec. 16, 2024, which is a U.S. National Stage Entry of International Application No. PCT/US2023/025518, filed Jun. 16, 2023, which claims the benefit of U.S. Provisional Application No. 63/353,072, filed Jun. 17, 2022, U.S. Provisional Application No. 63/390,804, filed Jul. 20, 2022, and U.S. Provisional Application No. 63/417,748, filed Oct. 20, 2022, the disclosures of which are incorporated by reference herein in their entireties.

Cleaning tools such as vacuum cleaners have been used for decades to aid in cleaning dirt and other debris from floors. Most vacuum cleaners have a built-in motor to facilitate air suction and an area to collect dirt, but the units are often heavy and bulky, thus making it difficult to deftly maneuver the unit around a given floorspace. Accordingly, there exist some drawbacks and other unsolved issues that limit the convenience of vacuum cleaners.

As noted above, there are some non-trivial issues with the designs of most vacuum cleaners. Many of the issues pertain to matters of convenience for the user. For example, vacuum cleaners are often difficult to maneuver around and under furniture or other obstacles. Additionally, the vacuum components such as a waste receptacle, filters, and a motor are often jammed together in a cramped space in an effort to reduce the weight, but at the cost of efficiency. Accordingly, some vacuum cleaner embodiments are described herein that use a unique elongated design that provides the various vacuum components along nearly an entire length of the vacuum cleaner and in-line with one another. According to some embodiments, at least one waste receptacle, a filter structure, and a motor are each axially aligned with a longitudinal central axis of a body of the vacuum cleaner. An air suction inlet may also be arranged at a distal end of the body and axially aligned with the longitudinal central axis. According to some embodiments, the body may have a substantially constant cross-sectional area along its entire length, and the length of the body is at least 50%, at least 60%, at least 75%, or at least 90% the entire length of the vacuum cleaner. As used herein, a substantially constant cross-sectional area, as it pertains to the vacuum body, is an area that changes by, at most, 10% along the length of the body. In some embodiments, the body is cylindrical such that the body maintains a substantially constant diameter along its entire length, and the length of the cylindrical body is at least 50%, at least 60%, at least 75%, or at least 90% the entire length of the vacuum cleaner. As used herein, a substantially constant diameter, as it pertains to the diameter of the vacuum body, is a diameter that changes by, at most, 10% along the length of the body. In other embodiments, there may be separate portions along the length of the vacuum cleaner that interrupt the constant diameter or constant cross-sectional area, however, the portions that do exhibit the constant diameter or constant cross-sectional area will be spaced along the length of the vacuum by at least 50%, 60%, 75%, or 90% the entire length of the vacuum cleaner.

The vacuum cleaner described herein includes numerous other useful features that provide an advantage over conventional designs. For example, the vacuum cleaner includes a hidden hinge along the length of its body that allows the body to be split into two sections about the hinge. As suggested by the name, the hinge may be located completely within the body such that no part of the hinge mechanism extends beyond the diameter of the body. According to some embodiments, the separation of the body sections also breaks an air suction pathway between the two sections. In some embodiments, a first body section is rotated away from a second section body section such that it can rest substantially parallel and adjacent to the second body section. In its folded configuration, the vacuum is about half its working length and can be stored in a small space. As used herein, two elongated objects that are “substantially parallel” to one another refers to the objects being within +−10 degrees of perfectly parallel to one another.

In some examples, the vacuum cleaner includes a filter arrangement that includes a cylindrical pre-filter and a cylindrical post filter within the cylindrical body of the vacuum cleaner. Each of the pre-and post-filter may be axially aligned with the longitudinal central axis of the cylindrical body of the vacuum cleaner. In some embodiments, the pre filter is concentrically arranged within the post filter to provide more efficient usage of the space within the body.

In some examples, the vacuum cleaner includes an in-line handle design that allows the user to grip the vacuum and maneuver it around as if the vacuum cleaner body were a continuous linear extension of their arm. According to some embodiments, the handle includes a grip that extends between first and second brackets. Each of the first bracket and the second bracket extends away from the proximal end of the body and substantially parallel to the longitudinal central axis of the body.

In some examples, the vacuum cleaner includes a waste receptacle design having two housing portions with one housing portion designed to axially slide within the other housing portion. According to some embodiments, the second housing portion can slide into the first housing portion (which may remain fixed) in order to push debris down into the first housing portion and clean any debris from accumulating along an air suction tube within the waste receptacle. A door at one end of the waste receptacle may be configured to swing open about a hinge in response to the second housing portion sliding into the first housing portion. In some embodiments, a handle may be coupled to a top wall of the second housing portion and coupled to the air suction tube, such that pulling on the handle also moves the top wall and air suction tube axially in an opposite direction to the movement of the second housing portion.

According to an embodiment, a vacuum cleaner includes a cylindrical body having a longitudinal central axis and a substantially constant diameter along an entire length of the body extending from a proximal end to a distal end, a waste receptacle within the body and adjacent to the distal end of the body, an air suction inlet at the distal end of the body, and a motor housed in the body between the waste receptable and the proximal end of the body. Each of the waste receptacle, the air suction inlet, and the motor are axially aligned with the longitudinal central axis of the cylindrical body.

According to another embodiment, a vacuum cleaner includes a cylindrical body having a substantially constant diameter along an entire length of the body extending from a proximal end to a distal end. The body has a first section and a second section along its length. The vacuum cleaner further includes a hinge mechanism located within the body such that the first section of the body is connected to the second section of the body via the hinge mechanism, a first air suction passageway within or on the first section of the body, and a second air suction passageway within or on the second section of the body. The first air suction passageway is connected to the second air suction passageway when the hinge mechanism is in an unfolded state such that first section of the body is aligned lengthwise along the same central axis as the second section of body. There is a break between the first air suction passageway and the second air suction passageway when the hinge mechanism is in a folded state such that the second section of the body is rotated away from the first section of the body.

According to another embodiment, a vacuum cleaner includes a cylindrical body, a motor disposed within the body and aligned centrally to a longitudinal axis passing through the center of the body, and a filter structure disposed adjacent to the motor and within the body. The filter structure includes a cylindrical pre-filter having a first diameter and a cylindrical post-filter disposed around the cylindrical pre-filter. The cylindrical post-filter has a second diameter greater than the first diameter.

According to an embodiment, a vacuum cleaner includes a cylindrical body having a longitudinal central axis, a waste receptacle within the cylindrical body, and an air suction tube extending through at least a portion of the waste receptacle. The waste receptacle includes a first housing section, a second housing section, and a slider grip coupled to the first housing section. The first housing section is designed to fit within the second housing section. Movement of the slider grip along a track causes a corresponding movement of the first housing section relative to the second housing section.

According to an embodiment, a waste receptacle is designed for use on a vacuum cleaner. The waste receptacle includes a first cylindrical housing section having a first diameter, a second cylindrical housing section having a second diameter larger than the first diameter, and a slider grip coupled to the first cylindrical housing section. The first cylindrical housing section is configured to fit within the second cylindrical housing section. Movement of the slider grip along a track causes a corresponding movement of the first cylindrical housing section relative to the second cylindrical housing section.

These and other such embodiments will be described in more detail herein.

Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent in light of this disclosure.

The description uses the phrases “in an embodiment” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present disclosure, are synonymous. When used to describe a range of dimensions, the phrase “between X and Y” represents a range that includes X and Y.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

illustrates a perspective three-dimensional view of a vacuum cleaner, according to an embodiment. Vacuum cleanerhas the general shape of a stick vacuum, however, it includes a cylindrical bodythat extends along nearly an entire length of vacuum cleaner. In some embodiments, cylindrical bodyhas a substantially constant diameter along its entire length that is between about 3″ and about 6″, or between about 4″ and about 5″. Cylindrical bodymay have a total length between a proximal end and a distal end of between about 2′ and about 3′. In some embodiments, a nozzle assemblymay be coupled to the distal end of cylindrical bodywhile a handlemay be coupled to a proximal end of cylindrical body. Nozzle assemblycan include a rotatable brush head or any other type of cleaning head for facilitating the gathering of debris from the floor or other surfaces.

According to some embodiments, bodyincludes one or more sections along its length. Each of the various sections may house certain vacuum components and provide one or more air suction pathways up through body. For example, bodycan include a first section, a second section, and a third section, each aligned axially along a longitudinal central axisof body. According to some embodiments, longitudinal central axisalso extends through a grip portion of handleat the proximal end of cylindrical body. In some embodiments, each of sections-may be designed to be modular such that they can be separated from one another for maintenance or to replace one or more parts. In some embodiments, first sectionmay be coupled to the remaining sections (e.g., sectionsand) via a hinge that allows second sectionto separate from first sectionabout the hinge. Further details of the hinge are provided herein.

According to some embodiments, the length of body(e.g., including each of the body sections) takes up a majority of the entire length of vacuum cleaner(including nozzle assembly, body, and handle). For example, the length of bodymay be at least 50%, at least 60%, at least 70%, at least 75%, at least 80%, or at least 90% the entire length of vacuum cleaner. This design is in contrast with other stick vacuums where a suction tube extends away from a primary body section and makes up a majority of the length of the vacuum cleaner.

According to some embodiments, first sectionof bodyincludes a waste receptacle and is longer than either of second sectionor third section. In some embodiments, first sectionof bodyhas a length that is at least 30%, at least 40% or at least 50% of the total length of body. According to some embodiments, an air suction tube extends either through the waste receptacle within first sectionor along an outside surface of the waste receptacle, as will be discussed in more detail herein.

Second sectionof bodymay include an additional waste receptacle designed to collect finer debris compared to the waste receptacle of first section. Second sectionmay be directly adjacent to first sectionalong the length of body. The finer debris may be collected by passing the suctioned air through one or more cyclonic structures within second section. The waste receptacle of second sectionmay be fluidically connected via an airflow path with the waste receptacle of first section.

According to some embodiments, third sectionmay be directly adjacent to second sectionand may include the power components of vacuum cleaner, such as the motor and energy storage devices. A filter structure may be included with the motor to provide filtration of air both before and after it has passed through the motor. As discussed above, both the filter structure and the motor may be axially aligned with longitudinal central axiswithin body. For example, longitudinal central axismay pass through the central axis of rotation of the motor. According to some embodiments, the components of third sectionconstitute the majority of the weight of vacuum cleaner.

According to some embodiments, nozzle assemblyincludes a pivot mechanismabout which bodycan move and/or twist relative to the brush head. Pivot mechanismmay be any known pivoting structure that allows for a large dynamic range of movement, such as a ball-in-socket joint. According to some embodiments, pivot mechanismis aligned along longitudinal central axis.

Each of sections-of bodymay be formed from injection molded plastic or from any suitably rigid plastic material. In some embodiments, a clear or translucent plastic may be used for body sectionto allow for visual inspection of the waste receptacle within section. In some embodiments, vacuum cleaneronly includes a single waste receptacle (e.g., located within first section) and thus third sectionmay be expanded to encompass second section. In this way, bodymay be considered as having only two sections with third sectionbeing adjacent to first section(e.g., no second section).

illustrates a view of several of the components within vacuum cleaneralong the length of bodywith the outside covers of each of the sections removed, according to some embodiments. Note that, in some embodiments, only some of the illustrated components may be present within vacuum cleaner. According to some embodiments, various ones of the components may each be centrally aligned to the longitudinal central axis of body.

According to some embodiments, a nozzle coupling structureis coupled to a distal end of body(e.g., adjacent to first section). Nozzle coupling structuremay neck down from a diameter of bodyto a smaller diameter that interfaces with a cleaning head. Nozzle coupling structuremay be an integral part of nozzle assembly, such that nozzle coupling structureand the cleaning brush head are one unit that is removably coupled to the distal end of body. Accordingly, nozzle coupling structureincludes an air suction pathway through, for example, a central portion of its structure. The air suction pathway through nozzle coupling structuremay be in fluidic communication with an air suction inlet at the distal end of body.

According to some embodiments, first sectionof bodyincludes a first air suction tubeand a mesh or screenthat wraps around a second air suction tube. According to some embodiments, air along with any collected debris is sucked up through first air suction tubeand into the first waste receptacle within first section. According to some embodiments, the first waste receptacle is defined by the volume in first sectionaround any components such as air suction tubeand mesh or screen. After being pulled into the first waste receptacle, the air continues to pass through mesh or screenwhere it is sucked up through the second air suction tube inside of mesh or screentowards second sectionof body. Mesh or screenmay be a wire mesh or similar mesh-like structure that prevents larger debris (e.g., larger than the mesh size) from passing through mesh or screen. Any larger debris that cannot pass through mesh or screenis collected within the first waste receptacle of first section. According to some embodiments, first air suction tubeis axially aligned along the central longitudinal axis of body. In some other embodiments, first air suction tuberuns along an outside surface of bodyalong a length of first section, as discussed in more detail herein.

As noted above, the suctioned air passes through mesh or screenand towards second sectionvia a second air suction tube. According to some embodiments, second sectionincludes a second waste receptacle in a volume around a hinge. The suctioned air may first pass through one or more cyclonic separatorsdesigned to remove smaller debris (e.g., dust particles) from the air and capture the smaller debris within the second waste receptacle. The suctioned air continues onward, after passing through cyclonic separators, to third section.

According to some embodiments, hingeis a hidden hinge design that allows the entire portion of bodyabove first sectionto separate and rotate away from first sectionabout hinge. According to some embodiments, hingeis designed to be completely encompassed within bodyin its unfolded state (as illustrated in). Further details regarding hingeand its operation are provided herein with reference to.

According to some embodiments, third sectionof bodyincludes a filter structure, a motor, and a battery pack. Filter structureincludes both a pre-filter and a post-filter arranged in the flow path of the air, according to some embodiments. Briefly, the suctioned air passes through the pre-filter before it is drawn through motorand is exhausted from motorand passes through the post-filter before being vented away from the vacuum cleaner. Both the pre- and post-filter may be cylindrical in shape and axially aligned along the central longitudinal axis of body. Accordingly, one filter may be concentrically arranged within the other. Motormay be any suitable vacuum motor, such as a universal motor, that draws air up through the various sections of body. According to some embodiments, motorhas between 200 and 250 airwatts (AW) of suction. Battery packmay hold any number of energy storage devices. The energy storage devices may be rechargeable batteries that are designed to remain within battery packand be charged externally. In some other examples, the energy storage devices are replaceable batteries (such as AA, AAA, C, or D batteries) that can be accessed and removed/replaced by the user.

illustrates a closer view of the distal end of bodyafter removing nozzle coupling structure. According to some embodiments, an air suction inletis present at the distal end of body. Air suction inletmay be axially aligned along central longitudinal axis. According to some embodiments, at least a portion of nozzle coupling structureinterfaces with air suction inletto create an airflow path through nozzle coupling structureand into air suction inlet. Air that is sucked into air suction inletpasses into first air suction tubeof first section, according to some embodiments.

According to some embodiments, the removal of nozzle coupling structurefrom the distal end of bodyexposes a foot structurearound air suction inlet. Foot structuremay include a horse-shoe structurethat can be used to guide debris into air suction inletas foot structureis guided along the ground. The distal end of bodyalso includes a waste receptacle doorthat can be released to swing open about a hinge at one end to empty the contents of the first waste receptacle in first sectionof body.

illustrate different views of vacuum cleanerin a folded configuration about hinge, according to some embodiments. As shown in, bodyhas been split nearly in half such that first sectionis separated from any remaining sections (e.g., sectionsand) via rotation about hinge. According to some embodiments, second sectionrotates about hingesuch that the longitudinal central axis of second sectionis substantially parallel with the longitudinal central axis of first section. In this context, substantially parallel means that the longitudinal central axis of second sectionand first sectionare within 10 degrees of being parallel with one another. In some examples, second sectionand third sectionmay be considered a single section, such that rotation occurs between first sectionand the combined single section that includes both sectionsand.

According to some embodiments, the rotation of the different body sections about hingemay cause handleto rest either against or directly adjacent to nozzle coupling structure. For example, the angled shape of handlemay fit against the angled taper of nozzle coupling structure.

The entire vacuum cleaner may rest on the floor in an upright position on nozzle assemblywhen in the folded state illustrated in. In the folded state, the center of gravity of the vacuum is shifted so that it resides above a central portion of nozzle, providing vertical stability in the folded state. This can be useful for storage purposes as it decreases the total length of the vacuum cleaner while still allowing it to stand on its own.

provides a closer look of hingeand the adjacent body sections while the vacuum cleaner (and hinge) is in the folded configuration. According to some embodiments, a first air suction passagewayat an end of first sectionmates with a second air suction passagewayat an end of second sectionto provide a closed airpath between first sectionand second sectionwhen hingeis in its unfolded state (e.g., when each of first sectionand second sectionare aligned along the same longitudinal central axis.) However, according to some embodiments, the air flow path between first air suction passagewayand second air suction passagewayis broken when hingeis in its folded state (e.g., when second sectionis rotated away from first section). The shape of the openings for each of first air suction passagewayand second air suction passagewaymay be crescent or semicircular, as illustrated, or any other suitable shape that allow the passageways to fit together when hingeis folded and provides a substantially airtight seal when in its operating state. As noted above, second air suction passagewaymay lead to one or more cyclonic structures within second sectiondesigned to separate dust and other small particles from the airstream to be deposited in a second waste receptacle. In some other examples, the second waste receptacle is omitted, and second air suction passagewayleads directly to one or more pre-filters before encountering the motor.

It should be understood that hingecan be utilized within any type of vacuum cleaner to fold between two sections of the vacuum cleaner. For example, hingecan be used within any standard upright vacuum cleaner, any stick vacuum cleaner, or any canister vacuum cleaner. Also, hingeinis configured to fold the vacuum cleaner in a front-to-back arrangement, but hingecould be designed to fold the vacuum cleaner in any other direction, such as directly sideways relative to front-facing direction of nozzle assembly.

In some embodiments, hingenot only allows the folded vacuum body portions to be substantially parallel but provides no interference between the two body portions. For example, when in the folded configuration, the shortest distance between the outer surfaces of the two body sections, at the hinged end, can be less than 10 mm, less than 5 mm, less than 2 mm or less than 1 mm. For instance, the outer surfaces of the portions that are joined together at hingecan be in contact with each other when the vacuum is folded. This means that in some embodiments the folded configuration takes up no more than twice the horizontal space as the unfolded (e.g., fully extended) configuration.

Hingeincludes a plurality of leavesthat rotate about one or more pins, such as a central pin.illustrates hingewhile in its unfolded state and shows further details regarding the various structures that make up hinge. Each of leavesmay have a similar shape and be alternatingly offset from one another in a stacked configuration. A central pinmay pass through each of leaves, such that each of leavescan rotate about central pin. According to some embodiments, a set of end pins-and-pass through alternating ones of leaves. For example, if four leavesare stacked together, first end pin-passes through the first and third leavessuch that the first and third leaves can rotate about first end pin-, while second end pin-passes through the second and fourth leavessuch that the second and fourth leavescan rotate about second end pin-. According to some embodiments, a set of interior pins-and-pass through alternating ones of leavesthat are different from the leaves passed through by the corresponding end pins-and-. For example, first interior pin-passes through the second and fourth leavessuch that the second and fourth leaves can rotate about first interior pin-, while second interior pin-passes through the first and third leavessuch that the first and third leavescan rotate about second interior pin-. In some embodiments, each of first end pin-and second end pin-are designed to laterally slide along corresponding tracks-and-. Leavesmay be contained within housing structures-and-that are designed to separate from one another when hingeis in a folded state.

According to some embodiments, a seammay exist along the outer surface of bodybetween first sectionand second section. Bodymay separate along seamduring rotation about hinge. A mechanical catch may be used to maintain the longitudinal alignment between the first and second body sections when hingeis in its unfolded state. This mechanical catch may be released using, for example, a pushbuttonon the outside of body, thus allowing for rotation of the different body sections about hinge.

illustrates another view along the length of bodywith various body segments removed. According to some embodiments, the first section of bodyincludes three different body segments, although any number of body segments can be used. For example, a lower body segment, a middle body segment, and an upper body segmentmay connect together to form the exterior housing of the first body section. Each of lower body segment, middle body segment, and upper body segmentmay be formed from injection-molded plastic or any sufficiently rigid plastic material. Middle body segmentmay be a transparent plastic to allow for visual inspection of the first waste receptacle.

According to some embodiments, the second body sectionincludes a single housing structurethat protects the various components within second section. According to some embodiments, housing structurealso extends over at least a portion of third body section, such as over filter structure. The portion of housingthat fits around filter structuremay include any number of ventsto allow for air that has passed through the post filter on filter structureto escape through ventsand away from the vacuum cleaner. Housingmay be formed from injection-molded plastic or any sufficiently rigid plastic material.

provides a closer view of the inside of the first waste receptacle, according to an embodiment. As discussed above, first air suction tubeextends axially through a middle of the first waste receptacle. Air is drawn upwards through first air suction tubewhere it eventually escapes out from openinginto the first waste receptacle. According to some embodiments, a ramp structuremay be provided adjacent to openingto help direct the air downwards into the first waste receptacle.

The mesh or screenhas been removed in this view to show the underlying second air suction tubewrapping around a portion of first air suction tube. Second air suction tubeincludes a plurality of windows(e.g., openings) that allow air to pass through them where it is sucked upwards and into the second body section. Any number of windowsmay be used and they may be any size and/or shape. Mesh or screen(removed in this view) may wrap around each of windowssuch that only the air along with particles small enough to pass through the filter enter through windowsand into second air suction tube.

As discussed above, the first air suction tube may also extend along an outside of the first waste receptacle rather than through a center of it.illustrates another view of a housing structure around the first waste receptacle, according to another embodiment. In this case, a housingincludes a distal endthat fluidically interfaces with, for example, air suction inletat the distal end of body. Housingalso includes a proximal endthat includes an opening to fluidically interface with any air suction tube structure within second body section. According to some embodiments, air suction tubeis fluidically connected with the opening at distal endand is drawn outside of housingsuch that it does not extend through the first waste receptacle. Air suction tubemay extend up a length of housingand wrap back into a top portion of housingto expel the air into the top of the first waste receptacle.

illustrates another view of housingpulled away from the first waste receptacle. Inside of housing, second air suction tube(illustrated here again without the filter) may still be used to bring the air within the first waste receptacle up into the second body section. According to some embodiments, housingmay be a single machined piece that includes a portion of air suction tubethat connects to a lower air passageway. Air passagewaymay be a curved passageway that directs air from the opening at distal endup into air suction tube. It should be noted that this design allows for second air suction tubeto have a larger interior volume as compared to the design illustrated inbecause it does not have the smaller first air suction tubeextending upwards through it.

illustrates a closer view of the second body section, according to some embodiments. Hingemay be located at least partially or fully within second body section. As discussed above, air is passed from first body sectioninto a second air suction passagewayand across a bridge(shown here with dashed lines) that acts as a fluidic connector between second air suction passagewayat a distal end of second body sectionand an openingleading into cyclonic separators. According to some embodiments, the air that is sucked into cyclonic separatorsis spiraled around the nozzle-like cyclonic structures allowing dust and other fine debris to fall out through nozzle openings. The debris may impact a flared skirtafter it has been ejected from nozzle openings. Skirtmay be provided to help spread the debris outwards into the surrounding second waste receptacle. According to some embodiments, the second waste receptacle includes the open volume around skirtand also the volume around the outside of bridge. A cover may be provided over hinge(such as shown over the left portion of hinge) to prevent debris from settling within hinge. According to some embodiments, bridgeand the outside housing walls of the second body sectionmay be formed from a single plastic piece.

As discussed above, some designs of the vacuum cleaner omit the second waste receptacle and thus both it and the cyclonic separatorsare not present. In such embodiments, air may be passed via bridge structuredirectly to filter structure.

illustrates an exploded view of filter structurearranged adjacent to a motor inlet, according to some embodiments. Housing structurehas been pulled away from the top portion of the vacuum cleaner to provide access to filter structure. According to some embodiments, filter structureincludes both a pre-filterand a post-filter. Each of pre-filterand post-filtermay be cylindrical. Post-filtermay have a slightly tapered cylindrical shape with a wider opening at its distal end compared to its proximal end.

According to some embodiments, pre-filteris arranged concentrically within post filter. As illustrated more clearly in, pre-filtermay have a diameter smaller than the diameter of post-filter, such that both filters can be concentrically aligned with the central longitudinal axis of body. In some examples, pre-filterhas a diameter between about 1″ and about 2″ or between about 0.5″ and about 1.5″. Post-filtermay have a diameter at its distal opening between about 2″ and about 3″ or between about 2.5″ and about 3.5″. As noted above, the diameter of the proximal opening of post-filtermay be slightly smaller, such as around 0.5″ less than the diameter of the distal opening of post-filter. Pre-filtermay include any known filter material designed to trap most particles from entering the motor. Examples of pre-filter material include activated carbon in powered, granular, or honeycomb form, or foam-based materials. Post-filtermay be a high efficiency particulate air (HEPA) filter. Pre-filterand post-filtermay be coupled together such that the entire filter arrangement can be removed in one piece. In some other embodiments, post-filtermay be removed separately from pre-filter.