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Title:
POWERED WINDOW AIR FILTER APPARATUS
Document Type and Number:
WIPO Patent Application WO/2017/033097
Kind Code:
A1
Abstract:
A powered window air filter apparatus that comprises a first, base unit and a second, movable unit.

Inventors:
GREGERSON, Glen O. (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
LAGESON, Kent E. (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
LUCHT, Steven G. (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
PILGRIM, John M. (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
PRINCE, David J. (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
ZHANG, Zhiqun (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
Application Number:
IB2016/054932
Publication Date:
March 02, 2017
Filing Date:
August 17, 2016
Export Citation:
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Assignee:
3M INNOVATIVE PROPERTIES COMPANY (3M Center, Post Office Box 33427Saint Paul, MN, 55133-3427, US)
International Classes:
F24F7/013; B01D46/10; E06B7/02; F24F3/16; F24F13/18
Domestic Patent References:
WO2006052099A22006-05-18
Foreign References:
US6099607A2000-08-08
US7122066B22006-10-17
US5334091A1994-08-02
US20100197214A12010-08-05
US4955997A1990-09-11
Attorney, Agent or Firm:
WOOD, Kenneth B. et al. (3M Center, Office of Intellectual Property CounselPost Office Box 3342, St. Paul MN, 55133-3427, US)
Download PDF:
Claims:
What is claimed is:

1. A powered window air filter apparatus, comprising:

a first, base unit that comprises a fan; and,

a second, movable unit that comprises an air filter;

wherein the second, movable unit is reversibly slidably movable back and forth relative to the first, base unit, between at least a first, unexpanded configuration and a second, expanded configuration, and

wherein the fan and the air filter are fluidically connected to each other by a conduit that includes at least one reversibly expandable and contractible section and that allows the second, movable unit to be reversibly slidably moved back and forth between the first, unexpanded configuration and the second, expanded configuration while maintaining the fluidic connection between the fan and the air filter.

2. The powered window air filter apparatus of claim 1, wherein the base unit and the movable unit each exhibit a longitudinal axis and a transverse axis, wherein the longitudinal axis of the base unit and the longitudinal axis of the movable unit are aligned with each other so as to define a longitudinal axis of the powered window air filter apparatus, and wherein the direction along which the movable unit is reversibly slidably movable is aligned with the longitudinal axis of the powered window air filter apparatus.

3. The powered window air filter apparatus of claim 1 wherein the air filter is positioned proximate an exterior-air inlet that is located on an upper portion of an exterior face of the movable unit of the apparatus, and wherein the base unit comprises a filtered-air outlet through which filtered air is motivated by the fan to exit the powered window air filter apparatus, the filtered-air outlet being located on a lower portion of an interior face of the base unit of the apparatus.

4. The powered window air filter apparatus of claim 1 wherein the reversibly expandable and contractible section of the conduit comprises a hollow tube that is reversibly expandable and contractible along its long axis, wherein the air filter, the hollow tube, and the fan are all aligned with each other in a longitudinally-stacked configuration, and wherein when the movable unit is in the first, unexpanded configuration, the aspect ratio of a longitudinal length of the powered window air filter apparatus to an interior-exterior thickness of the powered window air filter apparatus is at least about 6: 1.

5. The powered window air filter apparatus of claim 4 wherein the apparatus comprises first, second and third elongate retaining fins that each exhibit a long axis that is at least generally aligned with the long axis of the hollow tube, and wherein at least portions of the first, second and third retaining fins collectively circumscribe at least portions of the hollow tube.

6. The powered window air filter apparatus of claim 1 wherein the base unit and the movable unit each comprise first and second transverse walls that are tapered inwardly toward each other so that they are spaced further apart from each other at a position proximate an interior wall of the unit, and are spaced closer to each other at a position proximate an exterior wall of the unit.

7. The powered window air filter apparatus of claim 6 wherein the base unit and the movable unit each comprise first and second flanges that respectively extend at least generally transversely beyond the first and second transverse walls of the unit, at a location proximate the interior wall of the unit.

8. The powered window air filter apparatus of claim 6 wherein the first and second transverse walls of the base unit each comprise a generally transversely-outwardly -facing resilient layer along at least a portion of a longitudinal length of the transverse wall, and wherein the first and second transverse walls of the movable unit each comprise a generally transversely-outwardly-facing resilient layer along at least a portion of a longitudinal length of the transverse wall; and,

wherein when the movable unit is in the first, unexpanded condition, at least a portion of the resilient layer of the first transverse wall of the base unit exteriorly abuts a lower portion of the resilient layer of the first transverse wall of the movable unit, and at least a portion of the resilient layer of the second transverse wall of the base unit exteriorly abuts a lowermost portion of the resilient layer of the second transverse wall of the movable unit.

9. The powered window air filter apparatus of claim 6 wherein a lowermost surface of the base unit is provided by a downwardly-facing resilient layer, and wherein an uppermost surface of the movable unit is provided by an upwardly-facing resilient layer.

10. The powered window air filter apparatus of claim 1 wherein the air filter is a framed air filter comprising an air filter media with a rigid supporting frame mounted to the perimeter of the air filter media.

11. The powered window air filter apparatus of claim 1 wherein the apparatus comprises a one-way brake with a default configuration that is a first, engaged configuration, in which engaged configuration the brake allows the movable unit to move away from the first, unexpanded configuration toward the second, expanded configuration but prevents the movable unit from moving away from the second, expanded configuration toward the first, unexpanded configuration; and, wherein the brake can be actuated into a second, disengaged configuration that allows the movable unit to move reversibly back and forth in either direction between the first, unexpanded configuration and the second, expanded configuration.

12. The powered window air filter apparatus of claim 11 wherein the one-way brake is a non- stepwise brake that is configured so that when the brake is in the first, engaged configuration the brake allows the movable unit to move away from the first, unexpanded configuration toward the second expanded configuration in a continuous manner rather than in stepwise increments; and,

wherein the brake is configured so that when the brake is in the second, disengaged configuration, the brake allows the movable unit to move reversibly back and forth in either direction between the first, unexpanded configuration and the second, expanded configuration in a continuous manner rather than in stepwise increments.

13. The powered window air filter apparatus of claim 12 wherein the brake comprises an elongate slider bar that extends along at least a portion of the longitudinal axis of the apparatus and that is fixedly attached to either, but not both, of the base unit and the movable unit;

wherein the brake further comprises a braking member that is movably connected to the unit to which the slider bar is not fixedly attached, which braking member is biased by a biasing member into a default position in which the braking member allows the slider bar to slidably move only in a first direction that allows the movable unit to move away from the first, unexpanded configuration toward the second, expanded configuration and in which the braking member prevents the slider bar from moving in a second, opposite direction that allows the movable unit to move away from the second, expanded configuration toward the first, expanded configuration;

and, wherein the brake comprises an actuator whereby a user can manually actuate the brake so as to move the braking member away from the default position and into a position into which the slider bar is allowed to slidably move in either direction along the longitudinal axis of the apparatus so that while the brake is manually actuated, the movable unit can be moved reversibly back and forth between the first, unexpanded configuration and the second, expanded configuration.

14. The powered window air filter apparatus of claim 13 wherein the actuator that allows the brake to be manually disengaged by a user is located on an interior face of the base unit and wherein the slider bar is fixedly attached to the movable unit.

15. The powered window air filter apparatus of claim 13 wherein the braking member comprises a slot through which the elongate slider bar passes, wherein when the brake is in the first, default condition the slot of the braking member is positioned at a first angle relative to the long axis of the slider bar so that a surface of the braking member that at least partially defines the slot allows the slider bar to move in the first direction but frictionally prevents the slider bar from moving in the second direction;

wherein when the brake is actuated the slot of the braking member is moved from the first angle to a second angle relative to the long axis of the slider bar, at which second angle the braking member allows the slider bar to move back and forth in the first and second directions;

and wherein the second angle is greater than the first angle.

16. The powered window air filter apparatus of claim 1 wherein the apparatus further comprises a one-way speed limiter that limits the speed at which the movable unit can be moved away from the second, expanded configuration toward the first, unexpanded configuration but does not limit the speed at which the movable unit can be moved away from the first, unexpanded configuration toward the second, expanded configuration.

17. The powered window air filter apparatus of claim 16 wherein the one-way speed limiter comprises first and second rollers that define a gap through which the slider bar passes while contacting both rollers; wherein both rollers are configured to rotate freely in a direction that allows the slider bar to move in the first direction, and wherein both rollers are configured to have a limited rotational speed when turning in a direction that allows the slider bar to move in the second direction.

18. The powered window air filter apparatus of claim 1 wherein the fan is positioned inside a fan chamber that is defined by surfaces of the base unit and is not defined by any surfaces of the movable unit, and wherein a ceiling of the fan chamber is defined by a partition of the base unit.

19. The powered window air filter apparatus of claim 18 wherein a braking member of a one-way brake is movably connected to the base unit at a location that is outside of the fan chamber, and wherein an actuator that actuates the one-way brake is movably attached to the partition of the base unit and is positioned outside of the fan chamber.

20. The powered window air filter apparatus of claim 1 wherein all electrical components of the apparatus are located in the base unit and wherein the movable unit does not include any electrical component of any kind.

21. A kit comprising the powered window air filter apparatus of claim 1 wherein the kit further includes at least one replacement air filter assembly.

22. A method of installing the powered air filter apparatus of claim 1 into an opening in a sash window, the method comprising:

sliding a movable sash of the sash window so as to create an opening in the window;

positioning the powered air filter apparatus in the opening of the window, with a lowermost surface of the base unit of the powered air filter apparatus resting on a lower sill of the window and with a first transverse side of the powered air filter apparatus abutted against a side jamb of the sash window; slidably moving the movable portion of the powered air filter apparatus upward until an uppermost surface of the movable portion is abutted against an upper lintel of the sash window;

and,

slidably moving the movable sash of the sash window toward the powered air filter apparatus until an edge of the movable sash is abutted against a second transverse side of the powered air filter apparatus.

Description:
POWERED WINDOW AIR FILTER APPARATUS

Background

Windows are available in a wide variety of sizes and can include e.g. one or more movable sashes that can be slidably opened to allow airflow into the interior of a building. However, in many locations, the outside air may contain undesirable pollution or contaminants. It may thus be desirable to filter air that passes into a building through a window opening.

Summary

In broad summary, herein is disclosed a powered window air filter apparatus that comprises a first, base unit and a second, movable unit. These and other aspects will be apparent from the detailed description below. In no event, however, should this broad summary be construed to limit the claimable subject matter, whether such subject matter is presented in claims in the application as initially filed or in claims that are amended or otherwise presented in prosecution.

Brief Description of the Drawings

Fig. 1 is a perspective interior view of an exemplary powered window air filter apparatus, in a first, unexpanded condition.

Fig. 2 is a perspective exterior view of an exemplary powered window air filter apparatus, in a first, unexpanded condition.

Fig. 3 is a perspective interior view of an exemplary powered window air filter apparatus, in a second, expanded condition.

Fig. 4 is a perspective exterior view of an exemplary powered window air filter apparatus, in a second, expanded condition.

Fig. 5 is a perspective exploded interior view of an exemplary base unit and movable unit of a powered window air filter apparatus.

Fig. 6 is a perspective exploded exterior view of an exemplary base unit and movable unit of a powered window air filter apparatus.

Fig. 7 is a bottom view of an exemplary powered window air filter apparatus.

Fig. 8 is an interior view of an exemplary powered window air filter apparatus, with interior walls of the apparatus housing omitted.

Fig. 9 is a top perspective cross-sectional view of an exemplary powered window air filter apparatus.

Fig. 10 is an interior view of a portion of an exemplary powered window air filter apparatus, with interior walls of the apparatus housing omitted.

Fig. 11 is a partial cross-sectional view of an exemplary one-way brake of a powered window air filter apparatus, with the brake in an engaged configuration.

Fig. 12 is a partial cross-sectional view of an exemplary one-way brake of a powered window air filter apparatus, with the brake in a disengaged configuration. Fig. 13 is a view of an exemplary speed limiter of a powered window air filter apparatus.

Fig. 14 is an interior perspective view of an exemplary powered window air filter apparatus installed in a horizontal sash window.

Like reference numbers in the various figures indicate like elements. Some elements may be present in identical or equivalent multiples; in such cases only one or more representative elements may be designated by a reference number but it will be understood that such reference numbers apply to all such identical elements. Unless otherwise indicated, all figures and drawings in this document are not to scale and are chosen for the purpose of illustrating different embodiments of the invention. In particular the dimensions of the various components are depicted in illustrative terms only, and no relationship between the dimensions of the various components should be inferred from the drawings, unless so indicated.

As used herein as a modifier to a property or attribute, the term "generally", unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring a high degree of approximation (e.g., within +/- 20 % for quantifiable properties). The term "substantially", unless otherwise specifically defined, means to a high degree of approximation (e.g., within +/- 10% for quantifiable properties). The term "essentially" means to a very high degree of approximation (e.g., within plus or minus 2 % for quantifiable properties). It will be understood that the phrase "at least essentially" subsumes the specific case of an "exact" match. However, even an "exact" match, or any other characterization using terms such as e.g. same, equal, identical, uniform, constant, and the like, will be understood to be within the usual tolerances applicable to the particular circumstance rather than requiring absolute precision or a perfect match. All references herein to numerical parameters are understood to be calculable (unless otherwise noted) by the use of average values derived from a number of measurements of the parameter.

Detailed Description

Glossary

The following terminology is used in describing a window air filter apparatus that can be installed in a sash window of a building:

Terms such as interior and exterior and the like are defined with respect to the window and building; interior means toward a room in which window the air filter apparatus is installed; exterior means away from the room. By way of specific example, an interior side of the window air filter apparatus faces toward a room of the building; an exterior side of the window air filter apparatus faces away from the room and is in contact with environmental air that is desired to be filtered as it passes into the room.

Terms such as inside, outside, inward, outward, and the like, are defined with respect to the air filter apparatus; terms such as inward, inside, and the like denote a direction toward the geometric center of the air filter apparatus. Terms such as outward, outside and the like denote a direction away from the geometric center of the air filter apparatus.

The term longitudinal denotes a direction (L) along the long axis of an air filter apparatus. As installed in a sash window, the longitudinal axis of the air filter apparatus will be orthogonal to the direction of slidable movement of a movable sash of the sash window. In the case of a horizontal sash window (in which case the movable sash is movable back and forth in a horizontal direction with respect to the Earth), the longitudinal direction of the apparatus will be at least generally aligned with the vertical direction with respect to the Earth. The transverse direction (T) of an air filter apparatus is orthogonal to the longitudinal direction of the apparatus and is at least generally aligned with the direction of slidable movement of a movable sash in a window in which the apparatus is installed. The transverse direction can be considered to be the "width" direction of the apparatus as installed. The thickness direction (Th) of an air filter apparatus is orthogonal to the longitudinal direction of the apparatus and is orthogonal to the transverse direction of the apparatus. As installed in a sash window, the thickness direction of the apparatus is at least generally aligned with an interior-exterior axis of the window. The longitudinal direction (L), the transverse direction (T), and the thickness direction (Th) are shown for an exemplary air filter apparatus installed in a horizontal sash window in Fig. 14.

Terms such as upper, lower, upward, downward, above, below and the like are applied to an air filter apparatus installed in a horizontal sash window with the longitudinal axis of the apparatus being at least generally vertically aligned relative to the Earth, and have their customary meaning.

Disclosed herein is a powered window air filter apparatus 10, comprising a first, base unit 20 that comprises a fan, and a second, movable unit 60 that comprises an air filter assembly comprising an air filter media. The second, movable unit 60 is reversibly slidably movable back and forth relative to the first, base unit 20 between at least a first, unexpanded configuration and a second, expanded

configuration. Apparatus 10 is configured to be self-retaining in the second, expanded configuration (and also in any partially expanded configuration) as discussed in detail later herein. An exemplary apparatus 10 is shown in a first, unexpanded configuration in interior view (i.e., a view from within a room in a window of which the apparatus is installed) in Fig. 1 and in exterior view (i.e., a view from outside a room in a window of which the apparatus is installed) in Fig. 2. Apparatus 10 is shown in a second, expanded configuration in interior view in Fig. 3 and in exterior view in Fig. 4.

Base unit 20 comprises a lower, pedestal portion 36 and an upper, riser portion 25 as can be seen in the interior view of Fig. 5, in which movable unit 60 is exploded away from base unit 20. In some embodiments, portions 36 and 25 may be integral with each other, meaning that they are of the same composition and were made together as a single piece, at the same time in the same operation (e.g., an injection molding operation). In other embodiments, portions 36 and 25 may be made separately and then attached together in the manufacturing of apparatus 10. Movable unit 60 comprises an upper, shroud portion 75 and a lower, sleeve portion 65 as can be seen in Fig. 5. Portions 75 and 65 may be integral with each other, or may be separately made and attached together.

Base unit 20 and movable unit 60 may each comprise a main body (e.g., a housing) that is made e.g. of molded plastic, to which main body various additional components (e.g. one or more

weathershields, resilient layers, air conduits, fittings, brakes, speed limiters, and so on, as disclosed in detail later herein) may be attached. As is evident from Figs. 1, 5, and 6, when apparatus 10 is in an unexpanded condition, shroud portion 75 of movable unit 60 outwardly overlies and surrounds riser portion 25 of base unit 20. When apparatus 10 is in this unexpanded condition, sleeve portion 65 of movable unit 60 outwardly overlies pedestal portion 36 of base unit 20, on the exterior side 24 of base unit 20 and on a major portion of the transverse sides 66 of base unit 20. (Sleeve portion 65 is three-sided with an interior side being omitted so as to not block the flow of filtered air from fan 117 toward filter-air outlet 31, as will be appreciated e.g. from inspection of Figs. 5 and 8.)

Base unit 20 and movable unit 60 each exhibit a longitudinal axis and a transverse axis, the longitudinal axis of the base and movable units being aligned with each other so as to define a longitudinal axis (L) of the powered window air filter apparatus 10, as shown in Fig. 14. In many embodiments, the direction along which movable unit 60 is reversibly slidably movable relative to base unit 20 is at least substantially aligned with the longitudinal axis (L) of the powered window air filter apparatus, as will be evident from e.g. Figs 1 and 3.

When apparatus 10 is in an expanded condition, a portion of interior side 21 of riser portion 25 of base unit 20 may be exposed, as shown in Fig. 3; also, exterior side 24 of lower, pedestal portion 36 of base unit 20 may be exposed, as shown in Fig. 4. Thus, the interior side of apparatus 10 is provided by portions of walls of interior side 61 of movable unit 60 and of interior side 21 of base unit 20, as seen in Figs. 1 and 3. The exterior side (that faces e.g. outside into the environment) of apparatus 10 is provided by walls of exterior side 64 of movable unit 60 and by portions of walls of exterior side 24 of base unit 20, as seen in Figs. 2 and 4.

The exterior side of apparatus 10 may be exposed to environmental conditions such as rain, snow, hail, windblown debris, and so on. Accordingly, it will be appreciated that the design of apparatus 10, in which the exterior walls and transverse walls of base unit 20 and of movable unit 60 that are exposed to the environment are at least generally solid (e.g., with few or no unoccluded through-holes extending therethrough, except for e.g. an air inlet 71 as described later), and in which the exterior wall and transverse walls of movable unit 60 outwardly overlie the exterior wall and transverse walls of base unit 20, enhance the ability of these walls to minimize or prevent the entry of e.g. rain or snow into apparatus 10.

Movable unit 60 comprises a filter assembly 250 (seen most easily in Fig. 10) for filtering air. Accordingly, an exterior-air inlet (e.g., an opening) 71 is provided e.g. on an upper portion of exterior face 64 of shroud portion 75 of movable unit 60, as seen in Fig. 2. This exterior-air inlet may be exteriorly covered by a weathershield 72 (which may be provided e.g. a solid layer as in the exemplary design of Figs. 2 and 4, or which may be collectively provided by a set of louvers or the like) that at least substantially prevents the entry of e.g. liquid water into the exterior-air inlet. In particular, weathershield 72 may be shielded or enclosed at its upper end e.g. to prevent downwardly-moving rain water from entering the exterior-air inlet.

Base unit 20 comprises a fan 117 (as shown in exemplary embodiment in Fig. 8) for drawing exterior air in through exterior-air inlet 71 and through the filter media of air filter assembly 250, and expelling the filtered air into a room through filtered-air outlet 31 of base unit 20. Filtered-air outlet 31 may be located e.g. on the interior (room-facing) side 21 of lower, pedestal portion 36 of base unit 20; if desired, a cover 32 may be provided interiorly of filtered-air outlet 31, as shown in exemplary embodiment in Fig. 1. A fluidic connection must be provided between filter assembly 250 and fan 117; furthermore, this fluidic connection must allow the required movability of unit 60 and unit 20 relative to each other (while descriptions herein speak of moving unit 60 relative to unit 20, it will be appreciated that either unit can be moved relative to the other if desired). In order for this to be achieved, fan 117 and air filter assembly 250 are fluidically connected to each other by a conduit that includes at least one reversibly expandable and contractible section. This allows the units to be reversibly slidably moved back and forth between the first, unexpanded configuration and the second, expanded configuration while maintaining the fluidic connection between the fan and the air filter.

As shown in exemplary embodiment in Figs. 8 and 10, the fluidic connection between fan 117 and filter assembly 250 can be provided by a conduit that includes an air-receiving receptacle 112 that receives air that passes through filter media 255, which receptacle comprises an outlet fitting 113 that is mated to an upstream end of a hollow tube (hose) 114. The downstream end of tube 114 can be mated to an inlet fitting that is provided in a partition 115, which inlet fitting allows air to enter a fan chamber 116 containing fan 117. In some embodiments, hollow tube 114 may be reversibly expandable and contractible along its long axis (for example, tube 114 may be accordionized as shown in Figs. 8 and 10 to facilitate such expansion and contraction). This can allow units 60 and 20 to be moved relative to each other along the long axis of apparatus 10, while preserving the fluidic connection between filter assembly 250 and fan 117. (It will be appreciated that the above-described arrangement and components represent merely one convenient way of providing a fluidic connection; any suitable fluidic connection that preserves the movability of units 20 and 60 relative to each other may be used.)

In some embodiments, one or more retaining members may be provided to retain tube 114 in position e.g. to ensure that tube 114 does not unacceptably bow or kink when it is contracted along its long axis. In particular embodiments, such retaining members may take the form of elongate retaining fins that extend along at least a section of e.g. sleeve portion 65 and that protrude at least generally inward into the chamber within which tube 114 is positioned. Three such retaining fins are depicted in the view of Fig. 9; two major fins 121, and one minor fin 122 (one of the major fins 121 is also visible in Fig. 6; minor fin 122 is also visible in Fig. 13). Such fins may be positioned e.g. so that they collectively circumscribe at least a portion of the length of tube 114. By this is meant that at least one fin is present in each 120-degree segment of tube 114 (when viewed along the long axis of tube 114). As is evident in Fig. 9, it is not necessary to continuously circumferentially surround tube 114 in an uninterrupted manner for this purpose; the three-rib arrangement of Fig. 9 has been found acceptable for many instances.

It will be appreciated e.g. from Fig. 8 that in some embodiments air filter assembly 250 (which is directly behind the air-receiving receptacle 112 in the view of Fig. 8), hollow tube 114, and fan 117 may all be at least generally aligned with each other in a longitudinally-stacked configuration. By this is meant that these components are at least generally aligned with each other along the longitudinal axis of apparatus 10. Such an arrangement (in contrast to a design in which e.g. a fan is positioned interiorly of a filter assembly) can allow apparatus 10 to have a very small thickness dimension (that is, the dimension (Th) that extends interiorly-exteriorly, as shown in Fig. 14). It will be appreciated that this can advantageously provide that apparatus 10, when installed in an opening of a window, does not protrude very far out the window and thus will not interfere with e.g. a window screen, shutter, or the like, that might be present exteriorly of the window. This property can be characterized by means of an aspect ratio, which is defined as the ratio of the longitudinal length of the powered window air filter apparatus to the interior-exterior thickness of the powered window air filter apparatus. In various embodiments, when the movable unit is in the first, unexpanded configuration, the aspect ratio of the powered window air filter apparatus (measured at the point of maximum thickness of the apparatus) may be at least about 6: 1, 8: 1, 10: 1, or 12: 1.

In many embodiments, apparatus 10 may exhibit a tapered shape when viewed along the longitudinal axis of apparatus 10 (as is evident in the bottom view of Fig. 7). This may be provided by way of base unit 20 comprising first and second transverse sides 26 (provided by first and second sidewalls 38) that are tapered inwardly toward each other so that they are spaced further apart from each other at a position proximate interior side 21 of the base unit, and are spaced closer to each other at a position proximate exterior side 24 of the base unit, as shown in exemplary embodiment in Fig. 7.

Movable unit 60 may similarly comprise first and second transverse sides 66 (provided by first and second sidewalls 78) that are tapered inwardly toward each other so that they are spaced further apart from each other at a position proximate interior side 61 of the movable unit, and are spaced closer to each other at a position proximate exterior side 64 of the movable unit. Transverse sidewalls 38 and 78 of base unit 20 and movable unit 60 that establish a tapered shape in this manner, and with the sidewalls 78 of the movable unit outwardly overlying the sidewalls 38 of the base unit, are visible in the cutaway cross- sectional view of Fig. 9.

It will be appreciated that such a tapered shape of apparatus 10 can provide that when air filter apparatus 10 is installed in an opening of a sash window with the narrower end facing exteriorly and the wider end facing interiorly (as in Fig. 14), one transverse wall of apparatus 10 will abut a stationary jamb of the window, and the other transverse wall of apparatus 10 will abut an edge of the movable sash of the window, with the wide end of the tapered apparatus being on the interior side of the window opening. This arrangement can provide that apparatus 10 is less likely to be dislodged from the opening so as to fall outside of the window.

If desired, apparatus 10 may comprise one or more edge flanges that extend in a generally transverse direction, beyond the transverse edges of the main body of apparatus 10, so as to be positioned interiorly of an interior surface of e.g. the window jamb or an edge of the movable sash. Such features can additionally minimize the likelihood of apparatus 10 being dislodged so as to fall outside of the window. Thus in some embodiments, base unit 20 may comprise first and second flanges 33 that respectively extend at least generally transversely beyond the first and second transverse sidewalls 38 of the base unit, at a location proximate an interior side 21 of the base unit. Movable unit 60 may similarly comprise first and second flanges 63 that respectively extend at least generally transversely beyond the first and second transverse sidewalls 78 of the movable unit, at a location proximate interior side 61 of the movable unit. Such flanges may be e.g. made separately and attached respectively to the main bodies of the base unit and the movable unit; or, they may be integrally molded therewith. If desired, in some embodiments apparatus 10 may include one or more retaining straps with a first end that is attached to apparatus 10 and with a second end that can be attached to a retaining device (e.g., a hook) that can be mounted e.g. on an interior wall of a room, to a portion of the window frame, or the like.

Powered air filter apparatus 10 can be installed into an opening of a sash window, e.g. a horizontal sash window (meaning a window in which a movable sash thereof is slidably movable in a horizontal direction, e.g. as in the exemplary window 300 of Fig. 14). With reference to Fig. 14, this can be done by moving movable sash 301 (to the left, in the view of Fig. 14) to create an opening 305 in the window that is transversely wide enough to receive apparatus 10. Apparatus 10 can then be positioned in the opening, with a lowermost surface of lower end 28 of base unit 20 resting on the upward-facing surface 313 of a bottom sill 315 of the window frame 311, and with a first transverse side of apparatus 10 abutted against an inward-facing surface 312 of side jamb 317 of window frame 311. Movable unit 60 of apparatus 10 can then be moved slidably upward (along the long axis L of apparatus 10) until an uppermost surface of upper end 68 of movable unit 60 is abutted against a downward-facing surface 314 of an upper lintel 316 of window frame 311. (Apparatus 10 is self-retaining in this condition, e.g. by the use of a one-way brake as discussed later herein.) Movable sash 301 can then be slidably moved (to the right, in the view of Fig. 14) toward air filter apparatus 10 until an inward-facing face 303 of leading edge 302 of movable sash 301 is abutted against a second transverse side of air filter apparatus 10. In this manner apparatus 10 is transversely pinned in between leading edge 302 of movable sash 301 and side jamb 317; and, apparatus 10 is longitudinally pinned in between bottom sill 315 and upper lintel 316 of the window frame. Apparatus 10 can thus be securely held in place in the opening of the window. In some embodiments, apparatus 10 may be provided with one or more magnetic attachment elements, which can be magnetically attached to one or more complementary magnetic attachment elements that are positioned at a suitable location or locations on the window frame. Such arrangements and methods are described in detail in U.S. Provisional Patent Application No. xx/xxxxxx, attorney docket number 76686US002, entitled Magnetically Attachable Window Air Filter Apparatus, filed evendate herewith, the entirety of which is incorporated by reference herein.

To aid in the secure holding of apparatus 10 in place in a window opening 305, and/or to minimize any air leaks around apparatus 10, apparatus 10 can comprise resilient layers (comprised e.g. of foam rubber, or of any suitable resiliently compressible material) on various surfaces thereof. For example, a resilient layer 29 may be provided on the lower end 28 of base unit 20 e.g. so that a major surface of resilient layer 29 provides the aforementioned lowermost surface of base unit 20 that rests against the lower sill of the window frame. Similarly, a resilient layer 69 may be provided on the upper end 68 of movable unit 60 e.g. so that a major surface of resilient layer 69 provides the aforementioned uppermost surface of movable unit 60 that abuts the upper lintel of the window frame.

Resilient layers can similarly be provided on the first and second transverse sides of apparatus 10. As seen most easily e.g. in FIGs. 2 and 4, this may be achieved by way of first and second resilient layers 67 that are provided on at least portions of the first and second transverse sides 66 of movable unit 60, in combination with first and second resilient layers 27 that are provided on at least portions of the first and second transverse sides 26 of base unit 20. Such resilient layers may extend along at least a portion of the longitudinal length of the various transverse sides. In some embodiments, resilient layers 67 of movable unit 60 may each extend at least substantially along the entire longitudinal length of movable unit 60, including a portion 74 of resilient layer 67 that extends downward along sleeve portion 65 of movable unit 60, as seen in Figs. 2 and 4.

In some embodiments, resilient layers 27 of base unit 20 may each include a lowermost portion located proximate the lower end 28 of base unit 20, and also a portion 37 that extends upward along an exteriormost part of transverse side 26 of pedestal portion 36 of base unit 20, as seen in Figs. 2 and 4. Such arrangements can provide that when movable unit 60 is in the first, unexpanded condition, portion 37 of resilient layer 27 of a first transverse side 26 of base unit 20 exteriorly abuts lower portion 74 of resilient layer 67 of a first transverse side 66 of movable unit 60. Similar considerations hold for the second transverse walls of base unit 20 and movable unit 60. Such arrangements can also provide that when apparatus 10 is in an expanded condition (whether partially or fully expanded), a resilient layer may be provided at every point along the entire longitudinal length of the first and second transverse sides of apparatus 10, as is evident from Figs. 3 and 4. This can help ensure that a sufficiently air-tight seal is provided between the entire length of the first and second transverse sides of apparatus 10, and the window jamb and the leading edge of the window sash against which the first and second transverse sides are abutted, regardless of the extent to which unit 60 is expanded relative to unit 20. Apparatus 10 may use any suitable air filter assembly 250 comprising any suitable air filter media 255 (these components are most easily visible in the interior view of Fig. 10, in which receptacle 112 has been omitted so that filter assembly 250 can be seen). In some embodiments, air filter assembly 250 may comprise an air filter media 255, e.g. a pleated air filter media as shown in Fig. 10, with a rigid support frame (not visible in Fig. 10) mounted to the perimeter thereof. Such a support frame may be made of e.g. chipboard, one or more molded plastic pieces, and so on. For ease of access, weathershield 72 may be removable from exterior side 64 of movable unit 60, at which time a filter assembly 250 may be inserted into filter assembly holder 111 (visible in Fig. 10). It will be appreciated that air-receiving receptacle 112, as discussed earlier herein and as seen in exemplary embodiment in Fig. 8, may be conveniently positioned immediately inward of filter assembly holder 111 and may be attached e.g. to holder 111 and/or to any convenient part of movable unit 60. Weathershield 72 may be reattached (e.g., by snap- fitting) to exterior side 64 of movable unit 60 to hold air filter assembly 250 securely in place. Any suitable fastener(s), clamp(s), and so on, may be used as an adjunct to, or in place of, a snap-fit attachment. In some embodiments weathershield 72 may be e.g. hingedly connected to movable unit 60 to allow access to the filter holder, rather than weathershield 72 being separable from unit 60. In some embodiments, an air filter assembly may comprise a flexible frame; or, such an assembly may be provided by a piece of air filter media alone, which may be attached to a suitable holder by any desired fastening mechanism.

Filter media 255 may be any suitable filter media, chosen from e.g. fiberglass, fibrous polymeric webs, and so on. In some embodiments, an electrostatic charge is optionally imparted into or on to material(s) of filter media 255. In other words, an electrostatically charged media may be used, of which many grades are available, and many of which offer high efficiency with low pressure drop. Thus, the filter media can be, or include, an electret nonwoven web. Electric charge can be imparted to the filter media in a variety of ways as is well known in the art, for example by hydrocharging, corona charging, etc. In other embodiments, the filter media is not electrostatically charged. Additional multi-functional media grades, which incorporate activated carbon or other materials for purifying gas-phase pollutants, may also be incorporated into a layer of the filter media. The filter media can be constructed, for example, from nonwoven fibrous media formed of materials such as polypropylene, linear polyethylene or polyvinyl chloride. Other suitable, non-limiting materials for the filter media include porous foams, nonwovens, papers, fiberglass, or the like. In some embodiments, the filter media comprises a filter media that captures dust, allergens such as pollen and mold spores, and fine-particle pollutants, from the outdoor air. The filter media may be a single layer; or it may be a multilayer media comprised of multiple layers that serve various functions (e.g., it may include any or all of a primary particle-filtering layer, a coarse pre-filtering layer, and a gas or vapor absorbing layer).

As noted, a fan 117 is used to draw air in through inlet 71, through filter media 255, into and through receptacle 112, and into and through hollow tube 114. The fan also expels filtered air through outlet 31. A fan of any suitable type may be used, e.g. an axial -flow fan, a centrifugal fan, or a cross-flow fan. In particular embodiments, a centrifugal fan (often referred to as a squirrel-cage fan) may be used, with the fan comprising a long axis that coincides with the axis of rotation of the fan, which long axis is at least generally aligned with the long axis of base unit 20 in which the fan is mounted (all as shown in Fig. 8). Use of such a fan, mounted in such manner, can allow the filter, air conduit, and fan to be arranged in an a longitudinally-stacked configuration as described previously. Fan 117 can be driven by any suitable electric motor 118. In some embodiments, motor 118 and any other electrical components present, e.g. sensors, switches or the like, may be powered by an internal power source (e.g., a rechargeable battery). In other embodiments, such components may be powered by an external power cord that can enter base unit 20 e.g. through passage 35 (visible in Fig. 7).

In particular embodiments, all electrical components (including fan 117, and any on-off switches, fan speed control switches, operating circuitry, sensors, lights, indicators, and so on) of apparatus 10 may be located in base unit 20 (e.g., attached thereto, directly or indirectly). Such arrangements can provide that movable unit 60 need not include any electrical component of any kind, which can simplify the manufacture and operation of apparatus 10.

In some embodiments, fan 117 can be mounted in a fan chamber 116 that is defined within lower, pedestal portion 36 of base unit 20. A ceiling of such a fan chamber can be provided e.g. by partition 115 as shown in Fig. 8. In particular embodiments, partition 115 may be an at least generally horizontally- extending partition, to which various components of apparatus 10 may be conveniently attached as discussed later herein. Regardless of the particular design, partition 115 may comprise a through-passage through which air that is received from hollow tube 114 (which tube may be fluidically connected to partition 115 by way of e.g. any suitable fitting) can enter fan chamber 116.

It will be appreciated that the tolerances with which various components of apparatus 10 are abutted near each other and/or attached to each other may be controlled so as to minimize the number and/or amount of air leaks into apparatus 10. This may advantageously provide that little or no exterior air is able to bypass filter media 255 so as to e.g. allow unfiltered air to enter a building through apparatus 10. Such arrangements may also maximize the efficiency of power use (e.g., by minimizing the amount of room air that may enter fan chamber 116 and be inadvertently recirculated).

It will be appreciated that such tight-fitting of components to minimize air leaks must nevertheless preserve the ability to move units 60 and 20 back and forth relative to each other as previously described. In particular, the closeness with which the various walls (e.g., transverse walls, interior walls, and exterior walls) of base unit 20 and movable unit 60 approach each other can be controlled to provide a tight fit in at least portions of these units, as is evident in e.g. Fig. 9. (Fig. 9 also shows an exemplary arrangement of the various walls of units 20 and 60 that allow the units to be slidably moved relative to each other without coming apart from each other.) If desired, resilient layers (e.g., foam weatherstripping) can be provided e.g. between surfaces of base unit 20 and movable unit 60 at locations most advantageous to minimize air leaks. It will also be appreciated that the presence of partition 115 that provides a ceiling of fan chamber 116 (and also the use of close-fit tolerances on any items that pass through partition 115, e.g. a sliding bar as described later herein) can help ensure that even if unfiltered air is able to enter an upper portion of apparatus 10, such air may not be able to easily enter fan chamber 116.

As noted, in the installation of apparatus 10 into an opening of a window, apparatus 10 is placed into the opening e.g. with the lower end of base unit 20 resting on the window sill, and movable unit 60 is moved slidably upward until the upper end of movable unit 60 is abutted against the window lintel. In many embodiments, it may be useful for apparatus 10 to include a one-way brake 150 that allows movable unit 60 to be self-retaining in such a configuration, to render the installation easier for a user. Such a one-way brake may comprise a first, engaged configuration, in which engaged configuration the brake allows movable unit 60 to move away from the first, unexpanded configuration toward the second, expanded configuration. However, in the first, engaged configuration the brake prevents the movable unit from moving away from the second, expanded configuration toward the first, unexpanded configuration. With reference to Fig. 14, such a one-way brake can allow movable unit 60 to be moved upward as desired; and, unit 60 can then be left at any desired position without it being impelled by gravity to slidably move back downward. In particular embodiments, this engaged configuration is a default configuration of brake 150, meaning that the brake is always in the engaged configuration unless a user acts to remove the brake from the engaged configuration and to actively keep the brake from returning to an engaged configuration. This can provide that a user does not have to perform any action (e.g., pushing a button, turning a lever, etc.) to release the brake in order to slidably move unit 60 upward. Nor does a user have to continuously, or intermittently, perform any such action during the process of slidably moving unit 60 upward.

In at least some embodiments, brake 150 can be actuated (e.g., manually, by a user) into a second, disengaged configuration that allows movable unit 60 to be moved reversibly back and forth (e.g., up and down) in either direction between the first, unexpanded configuration and the second, expanded configuration. Thus, brake 150 can be actuated into the second, disengaged configuration when it is desired to put apparatus 10 into an unexpanded condition (e.g., so that apparatus 10 can be more easily removed from a window). In embodiments in which the engaged configuration of brake 150 is a default configuration, the actuation must be maintained to keep the brake disengaged in order to keep moving unit 60 toward the first, unexpanded configuration. That is, if the actuation is performed e.g. by pushing a button, the user must keep the button pushed in order to keep moving unit 60 toward an unexpanded configuration.

Brake 150 can take the form of any braking device or mechanism that can perform the above- described one-way braking when engaged, and can allow bidirectional motion when disengaged. In various embodiments, such one-way braking devices may rely on e.g. ratchets, cog wheels, and so on. However, in some embodiments, brake 150 is a non-stepwise brake, meaning that brake 150 is configured so that when the brake is in the engaged configuration the brake allows movable unit 60 to be moved away from the first, unexpanded configuration toward the second, expanded configuration, in a continuous manner (e.g. any desired amount, e.g. a fraction of a millimeter) rather than in stepwise increments. (Such a brake will also, when disengaged, allow continuous rather than stepwise motion, in either direction.)

Any suitable one-way, non-stepwise brake can be used as desired. In some embodiments, such a brake may rely on one or cams that has a protrusion that when in a first, engaged configuration, frictionally impinges on a member at an angle so as to allow motion in one direction but not in the opposite direction. The one or more cams can be rotated to a second, disengaged configuration in which each cam is spaced away from the member so as to allow movement in either direction. One-way, non- stepwise brakes of this general type are described in U.S. Provisional Patent Application No. xx/xxxxxx, attorney docket number 76771US002, entitled Unpowered Window Air Filter Apparatus, filed evendate herewith, which is incorporated by reference herein in its entirety. Any such brake can be actuated by any suitable actuator, e.g. a push-button, a handle to be turned or pulled, and so on.

In some embodiments, such a one-way, non-stepwise brake 150 is of the general type depicted in Figs. 11 and 12 (an exemplary suitable location for a brake 150 in apparatus 10 is seen in Figs. 8 and 10). Brake 150 utilizes an elongate slider bar 151 that extends along at least a portion of the longitudinal axis of apparatus 10 (the entire length of slider bar 151 is most easily seen in Fig. 8). Slider bar 151 is fixedly attached to either, but not both, of base unit 20 and movable unit 60. (In the exemplary embodiments of Figs. 11 and 12, slider bar 151 is fixedly attached to movable unit 60 (by attachment 169 as most easily seen in Fig. 10), and is not fixedly attached to base unit 20.) As is evident from Figs. 8 and 10, in this exemplary design slider bar 151 passes through the earlier-described partition 115. A through-opening is provided in partition 115 for this purpose, which through-opening is sized and shaped to closely abut the sides of slider bar 151 to assist in retaining slider bar 151 in position, and also in order to minimize any air leaks through partition 115 into fan chamber 116.

Brake 150 further comprises a braking member 152 that is movably connected to the unit to which slider bar is not fixedly attached. In the depicted embodiment of Figs. 11 and 12 braking member 152 is movably connected to base unit 20 by way of bracket 158. Braking member 152 is biased by a biasing member 154 (in this embodiment, a coil spring) into a default position in which braking member 152 allows slider bar 151 to slidably move only in a first direction (upward, in the view of Fig. 11) that allows movable unit 60 to move away from the first, unexpanded configuration toward the second, expanded configuration. In this default position, braking member 152 prevents slider bar 151 from moving in a second direction (downward, in the view of Fig. 11) that would allow movable unit 60 to move away from the second, expanded configuration toward the first, expanded configuration. Brake 150 further comprises an actuator (a push-button 34, in the depicted embodiment) whereby a user can manually actuate brake 150 so as to move (e.g., to rotatably move) braking member 152 away from the default position and into a position in which slider bar 151 is allowed to slidably move in either direction along the longitudinal axis of the apparatus 10. Such a position of braking member 152 is illustrated in exemplary embodiment in Fig. 12. Thus, while brake 150 is manually actuated, movable unit 60 can be moved reversibly back and forth relative to base unit 20, e.g. between the second, expanded configuration and the first, unexpanded configuration.

In the exemplary design of Figs. 11 and 12, braking member 152 comprises a slot 153 through which elongate slider bar 151 passes (in the depicted design, slot 153 is partially open on one side rather than circumferentially surrounding slider bar 151 on all sides). When brake 150 is in the first, default condition slot 153 is positioned at a first angle relative to the long axis of slider bar 151 so that a surface of braking member 152 that at least partially defines slot 153, allows slider bar 151 to move in a first direction (again, upward in the view of Fig. 11) but frictionally prevents slider bar 151 from moving in a second direction (downward, in the view of Fig. 11). When brake 150 is actuated, slot 153 is moved (e.g., by the rotating movement of braking member 152) from the first angle to a second angle relative to the long axis of the slider bar 151. As can be seen from comparison of Figs. 11 and 12, the second angle is greater than the first angle (in other words, the second angle corresponds to a major plane of braking member 152 and slot 153 thereof being more nearly perpendicular to the long axis of slider bar 151, than they are when at the first angle). With slot 153 positioned at this second angle, braking member 152 now allows slider bar 151 to move back and forth in both of the first and second directions.

In the exemplary design of Figs. 11 and 12, a first terminal end of braking member 152 is seated in a notch 159 of bracket 158, thus allowing rotating movement of braking member 152 (about an axis that corresponds closely to the first terminal end of braking member 152). A second terminal end of braking member 152 is positioned to be impinged by an angled (e.g., wedge-shaped) protrusion 155 that is slidably movable toward the second terminal end of braking member 152 to rotatably move braking member 152 as described above. (In the exemplary design of Figs. 11, a U-shaped spacer 156 is provided between the surfaces of braking member 152 and angled protrusion 155, e.g. for smoother operation.) Wedge-shaped protrusion 155 is connected to actuator button 34, button 34 being part of an assembly that includes protrusion 155 and that is attached by slidable connections 157 to partition 115 of base unit 20. Thus, button 34 can be pushed to move it slidably inwards (from the position shown in Fig. 11, to the position shown in Fig. 12) to actuate brake 150 into the second, disengaged position.

In the depicted embodiment, biasing member 154 applies a force to braking member 152 which in turn applies force to protrusion 155 of the actuator button assembly, to move the actuator button assembly outward unless continued inward force is applied to button 34 by a user. Thus, this exemplary design provides a brake 150 in which the default configuration of the brake is an engaged position as exemplified by Fig. 11. While biasing member 154 is a coil spring in the depicted embodiment, any type of spring or suitable biasing member may be used. As noted, bracket 158 is provided to facilitate the desired manipulation of braking member 152. In the illustrated embodiment, bracket 158 also includes a slot that partially surrounds slider bar 151 and that (e.g., in combination with the above-described through-opening in partition 115), help to retain slider bar 151 stably in place even as bar 151 e.g. moves back or forth along its long axis.

In the above-described embodiment, slider bar 151 is fixedly attached to movable unit 60 and is not attached to base unit 20 (rather, brake 150 is attached to base unit 20). In an alternative embodiment, this could be reversed with slider bar 151 being fixedly attached to base unit 20 and with brake 150 thus being attached to movable unit 60. However, it will be appreciated that the depicted arrangement allows actuator button 34 to be positioned on base unit 20 rather than on movable unit 60, with the advantageous result that button 34 may remain more easily reachable by a user even when movable unit 60 is in its most expanded (e.g., its highest possible) position.

As discussed above, in at least some embodiments movable unit 60 of apparatus 10 can be moved toward an expanded configuration, e.g. upward, and a one-way brake 150 can provide that movable unit 60 will not move back downward to any appreciable extent (even if the user lets go of movable unit 60) unless the brake is disengaged. When the brake is disengaged, movable unit 60 can then be moved downward (or allowed to move downward under the influence of gravity). In some embodiments, it may be advantageous for apparatus 10 to comprise a one-way speed limiter 160 that limits the speed at which movable unit 60 can be moved away from the second, expanded configuration toward the first, unexpanded configuration (such movement, in most uses of apparatus 10, will correspond to a downward direction relative to the Earth). However, limiter 160 will not appreciably limit the speed at which movable unit 60 can be moved away from the first, unexpanded configuration toward the second, expanded configuration (such a movement, in most uses of apparatus 10, will correspond to an upward direction).

Limiter 160 can be of any suitable design, operating by any suitable mechanism of action. In some embodiments, limiter 160 can be of the general type shown in Fig. 13 (a exemplary suitable location for a limiter 160 within apparatus 10 is seen in Fig. 10). A limiter of this type can make use of the same slider bar 151 described previously for use with one-way brake 150. Limiter 160 comprises first and second rollers 161 that define a gap through which slider bar 151 passes while contacting both rollers. Both rollers are configured to rotate freely in a direction that allows the slider bar to move in a first direction that corresponds to movement of movable unit 60 toward an expanded configuration. That is, both rollers may "freewheel" to allow the slider bar to move in this direction (which direction is upward in the view of Figs. 10 and 13). At least one of the rollers (in some embodiments, both rollers) is configured to have a limited rotational speed when turning in a direction that allows slider bar to move in a second direction that corresponds to movement of unit 60 toward an unexpanded configuration. In some embodiments, one or both rollers may comprise at least a radially outermost resilient layer 162 that is at least somewhat compressible. The width of the gap between the outermost surfaces of the two rollers may then be set to be slightly less than the width of the slider bar that passes therebetween. This can provide that the slider bar is held between the rollers with a slight compression fit, which can enhance the smooth operation of the limiter.

Regardless of the specific configuration and components, such arrangements can provide that when the one-way brake is actuated to disengage the brake to allow movable unit 60 to move downward, away toward an unexpanded configuration, the limiter can ensure that the Earth's gravity does not cause unit 60 to move downward too rapidly. It will thus be appreciated that the arrangements disclosed herein can allow a user to grasp base unit 20 (e.g. by grasping either lower handle 22 or upper handle 23), and to push actuator button 34. This can allow movable unit 60 to gently descend, motivated by gravity but with the speed limited by limiter 160, without the user necessarily having to grasp any portion of movable unit 60 during this process. (To raise unit 60 to an expanded condition, a user can of course grasp handle 22 or 23 of base unit 20 with one hand, and grasp handle 62 of movable unit 60 with the other hand to raise unit 60, since it is not necessary to push actuator button 34 in order to move unit 60 in this direction.)

If desired, apparatus 10 may include a scent element that can be inserted at any convenient point along the air pathway from inlet 71 to outlet 31. The moving air may impinge on the scent element (e.g., the air may pass through it, if the scent element is e.g. a fibrous web that is loaded with a scent) so as to volatilize any scent therein. (The term scent is used broadly, to encompass e.g. any fragrance, essential oil, and so on, that a user may desire to have broadcast into e.g. a living space.) In some embodiments, a scent element may be a fibrous web as noted, which web may be insertable into the air pathway e.g. through an entry slot. Or a scent element may be provided by way of having a receptacle or pathway into which a liquid scent (e.g., an essential oil) can be placed (e.g., with a dropper) and from which it is able to follow a flowpath into the air pathway.

If desired, a piece (e.g., an elongate length) of resilient material (e.g. foam rubber,

weatherstripping, or the like) can be inserted in between the glass of the movable sash 301, and the glass of the other (e.g., non-movable) sash 304, e.g. at location 318 of Fig. 14, in order to minimize any passage of unfiltered air through the small gap between these glass layers that may result from the window being (partly) open.

Also if desired, a window-stop may be positioned e.g. at location 319 of Fig. 14. Such a window- stop may ensure that movable sash 301 is not inadvertently moved (leftward, in the view of Fig. 14) away from its position of being abutted against a lateral side of apparatus 10. Such a window-stop may be any suitable item, e.g. a rubber wedge whose leading edge may be jammed against the trailing edge of movable sash 301, an elongate rod with one end abutted against the trailing edge of movable sash 301 and the other end abutted against the side jamb of the window frame, and so on. Either or both of such a piece or pieces of e.g. weatherstripping, and a window-stop, may be included in a kit that e.g. comprises an apparatus 10 (which may already have one filter assembly 250 installed therein) and that comprises one or more replacement filter assemblies, instructions for use, and so on.

Although discussions herein have focused on sash windows with e.g. one horizontally movable sash and with one sash that is fixed in place, it will be appreciated that apparatus 10 may easily be installed in a window that comprises two horizontally movable sashes (in such case, either sash may be chosen to be moved so as to provide a window opening in which to install apparatus 10). Moreover, although discussions herein have focused on horizontal sash windows (meaning windows with at least one movable sash that is movable in a direction that is at least generally horizontal with respect to the Earth), it will be appreciated that apparatus 10 may be easily installed in a vertical sash window (meaning a window with at least one movable sash that is movable in a direction that is at least generally vertical with respect to the Earth). In such a case, the movable sash may be moved e.g. upward to provide an opening with a vertical span sufficient to accommodate the transverse direction (the width) of apparatus 10. Apparatus 10 may then be positioned so that the "lower" end 28 of apparatus 10 abuts a first jamb of the window, and so that the "upper" end 68 of apparatus 10 abuts a second jamb of the window, and with one transverse side of apparatus 10 resting on the window sill. After this, the vertically-movable sash can then be moved downward so that its leading edge is abutted against the other transverse side of apparatus 10. (Apparatus 10 could also be installed in an opening in the upper part of a vertical sash window, rather than in an opening in the lower part.)

It will thus be appreciated that installation and use of apparatus 10 in a vertical sash window can be performed in the same manner as described herein with regard to a horizontal sash window, with apparatus 10 merely being rotated e.g. 90 degrees with respect to the Earth. It will thus be understood that the use herein of terms such as upper, lower, above, below, uppermost, lowermost, and so on, are used for convenience of description in the exemplary embodiment of installation of apparatus 10 in a horizontal sash window; it is emphasized that such language does not limit the use of apparatus 10 to horizontal sash windows.

List of Exemplary Embodiments

Embodiment 1 is a powered window air filter apparatus, comprising: a first, base unit that comprises a fan; and, a second, movable unit that comprises an air filter; wherein the second, movable unit is reversibly slidably movable back and forth relative to the first, base unit, between at least a first, unexpanded configuration and a second, expanded configuration, and wherein the fan and the air filter are fluidically connected to each other by a conduit that includes at least one reversibly expandable and contractible section and that allows the second, movable unit to be reversibly slidably moved back and forth between the first, unexpanded configuration and the second, expanded configuration while maintaining the fluidic connection between the fan and the air filter.

Embodiment 2 is the powered window air filter apparatus of embodiment 1, wherein the base unit and the movable unit each exhibit a longitudinal axis and a transverse axis, wherein the longitudinal axis of the base unit and the longitudinal axis of the movable unit are aligned with each other so as to define a longitudinal axis of the powered window air filter apparatus, and wherein the direction along which the movable unit is reversibly slidably movable is aligned with the longitudinal axis of the powered window air filter apparatus.

Embodiment 3 is the powered window air filter apparatus of any of embodiments 1-2 wherein the air filter is positioned proximate an exterior-air inlet that is located on an upper portion of an exterior face of the movable unit of the apparatus, and wherein the base unit comprises a filtered-air outlet through which filtered air is motivated by the fan to exit the powered window air filter apparatus, the filtered-air outlet being located on a lower portion of an interior face of the base unit of the apparatus.

Embodiment 4 is the powered window air filter apparatus of any of embodiments 1-3 wherein the reversibly expandable and contractible section of the conduit comprises a hollow tube that is reversibly expandable and contractible along its long axis, wherein the air filter, the hollow tube, and the fan are all aligned with each other in a longitudinally-stacked configuration, and wherein when the movable unit is in the first, unexpanded configuration, the aspect ratio of a longitudinal length of the powered window air filter apparatus to an interior-exterior thickness of the powered window air filter apparatus is at least about 6: 1. Embodiment 5 is the powered window air filter apparatus of embodiment 4 wherein the apparatus comprises first, second and third elongate retaining fins that each exhibit a long axis that is at least generally aligned with the long axis of the hollow tube, and wherein at least portions of the first, second and third retaining fins collectively circumscribe at least portions of the hollow tube.

Embodiment 6 is the powered window air filter apparatus of any of embodiments 1-5 wherein the base unit and the movable unit each comprise first and second transverse walls that are tapered inwardly toward each other so that they are spaced further apart from each other at a position proximate an interior wall of the unit, and are spaced closer to each other at a position proximate an exterior wall of the unit. Embodiment 7 is the powered window air filter apparatus of embodiment 6 wherein the base unit and the movable unit each comprise first and second flanges that respectively extend at least generally transversely beyond the first and second transverse walls of the unit, at a location proximate the interior wall of the unit. Embodiment 8 is the powered window air filter apparatus of any of embodiments 6-7 wherein the first and second transverse walls of the base unit each comprise a generally transversely- outwardly-facing resilient layer along at least a portion of a longitudinal length of the transverse wall, and wherein the first and second transverse walls of the movable unit each comprise a generally transversely- outwardly-facing resilient layer along at least a portion of a longitudinal length of the transverse wall; and, wherein when the movable unit is in the first, unexpanded condition, at least a portion of the resilient layer of the first transverse wall of the base unit exteriorly abuts a lower portion of the resilient layer of the first transverse wall of the movable unit, and at least a portion of the resilient layer of the second transverse wall of the base unit exteriorly abuts a lowermost portion of the resilient layer of the second transverse wall of the movable unit. Embodiment 9 is the powered window air filter apparatus of any of embodiments 1-8 wherein a lowermost surface of the base unit is provided by a downwardly-facing resilient layer, and wherein an uppermost surface of the movable unit is provided by an upwardly -facing resilient layer. Embodiment 10 is the powered window air filter apparatus of any of embodiments 1-9 wherein the air filter is a framed air filter comprising an air filter media with a rigid supporting frame mounted to the perimeter of the air filter media.

Embodiment 11 is the powered window air filter apparatus of any of embodiments 1-10 wherein the apparatus comprises a one-way brake with a default configuration that is a first, engaged

configuration, in which engaged configuration the brake allows the movable unit to move away from the first, unexpanded configuration toward the second, expanded configuration but prevents the movable unit from moving away from the second, expanded configuration toward the first, unexpanded configuration; and, wherein the brake can be actuated into a second, disengaged configuration that allows the movable unit to move reversibly back and forth in either direction between the first, unexpanded configuration and the second, expanded configuration. Embodiment 12 is the powered window air filter apparatus of embodiment 11 wherein the one-way brake is a non-stepwise brake that is configured so that when the brake is in the first, engaged configuration the brake allows the movable unit to move away from the first, unexpanded configuration toward the second expanded configuration in a continuous manner rather than in stepwise increments; and, wherein the brake is configured so that when the brake is in the second, disengaged configuration, the brake allows the movable unit to move reversibly back and forth in either direction between the first, unexpanded configuration and the second, expanded configuration in a continuous manner rather than in stepwise increments. Embodiment 13 is the powered window air filter apparatus of embodiment 12 wherein the brake comprises an elongate slider bar that extends along at least a portion of the longitudinal axis of the apparatus and that is fixedly attached to either, but not both, of the base unit and the movable unit; wherein the brake further comprises a braking member that is movably connected to the unit to which the slider bar is not fixedly attached, which braking member is biased by a biasing member into a default position in which the braking member allows the slider bar to slidably move only in a first direction that allows the movable unit to move away from the first, unexpanded configuration toward the second, expanded configuration and in which the braking member prevents the slider bar from moving in a second, opposite direction that allows the movable unit to move away from the second, expanded configuration toward the first, expanded configuration; and, wherein the brake comprises an actuator whereby a user can manually actuate the brake so as to move the braking member away from the default position and into a position into which the slider bar is allowed to slidably move in either direction along the longitudinal axis of the apparatus so that while the brake is manually actuated, the movable unit can be moved reversibly back and forth between the first, unexpanded configuration and the second, expanded configuration. Embodiment 14 is the powered window air filter apparatus of embodiment 13 wherein the actuator that allows the brake to be manually disengaged by a user is located on an interior face of the base unit and wherein the slider bar is fixedly attached to the movable unit. Embodiment 15 is the powered window air filter apparatus of any of embodiments 13-14 wherein the braking member comprises a slot through which the elongate slider bar passes, wherein when the brake is in the first, default condition the slot of the braking member is positioned at a first angle relative to the long axis of the slider bar so that a surface of the braking member that at least partially defines the slot allows the slider bar to move in the first direction but frictionally prevents the slider bar from moving in the second direction; wherein when the brake is actuated the slot of the braking member is moved from the first angle to a second angle relative to the long axis of the slider bar, at which second angle the braking member allows the slider bar to move back and forth in the first and second directions; and wherein the second angle is greater than the first angle.

Embodiment 16 is the powered window air filter apparatus of any of embodiments 1-15 wherein the apparatus further comprises a one-way speed limiter that limits the speed at which the movable unit can be moved away from the second, expanded configuration toward the first, unexpanded configuration but does not limit the speed at which the movable unit can be moved away from the first, unexpanded configuration toward the second, expanded configuration. Embodiment 17 is the powered window air filter apparatus of embodiment 16 wherein the one-way speed limiter comprises first and second rollers that define a gap through which the slider bar passes while contacting both rollers; wherein both rollers are configured to rotate freely in a direction that allows the slider bar to move in the first direction, and wherein both rollers are configured to have a limited rotational speed when turning in a direction that allows the slider bar to move in the second direction.

Embodiment 18 is the powered window air filter apparatus of any of embodiments 1-17 wherein the fan is positioned inside a fan chamber that is defined by surfaces of the base unit and is not defined by any surfaces of the movable unit, and wherein a ceiling of the fan chamber is defined by a partition of the base unit. Embodiment 19 is the powered window air filter apparatus of embodiment 18 wherein a braking member of a one-way brake is movably connected to the base unit at a location that is outside of the fan chamber, and wherein an actuator that actuates the one-way brake is movably attached to the partition of the base unit and is positioned outside of the fan chamber.

Embodiment 20 is the powered window air filter apparatus of any of embodiments 1-19 wherein all electrical components of the apparatus are located in the base unit and wherein the movable unit does not include any electrical component of any kind.

Embodiment 21 is a kit comprising the powered window air filter apparatus of any of embodiments 1-20 wherein the kit further includes at least one replacement air filter assembly.

Embodiment 22 is the kit of embodiment 21 wherein the kit further includes at least one piece of resilient weatherstripping that, when a sash window is partially open with the powered air filter apparatus installed into an opening of the window, can be positioned in a space between a first sash of the window and a second sash of the window to at least substantially prevent airflow therethrough. Embodiment 23 is the kit of any of embodiments 21-22 wherein the kit further includes at least one window-stop that can be positioned on a sill of the sash window so as to at least substantially prevent a movable sash of the window from being moved so as to open the window further.

Embodiment 24 is a method of installing the powered air filter apparatus of any of embodiments 1-20 into an opening in a sash window, the method comprising: sliding a movable sash of the sash window so as to create an opening in the window; positioning the powered air filter apparatus in the opening of the window, with a lowermost surface of the base unit of the powered air filter apparatus resting on a lower sill of the window and with a first transverse side of the powered air filter apparatus abutted against a side jamb of the sash window; slidably moving the movable portion of the powered air filter apparatus upward until an uppermost surface of the movable portion is abutted against an upper lintel of the sash window; and, slidably moving the movable sash of the sash window toward the powered air filter apparatus until an edge of the movable sash is abutted against a second transverse side of the powered air filter apparatus.

It will be apparent to those skilled in the art that the specific exemplary elements, structures, features, details, configurations, etc., that are disclosed herein can be modified and/or combined in numerous embodiments. All such variations and combinations are contemplated by the inventor as being within the bounds of the conceived invention, not merely those representative designs that were chosen to serve as exemplary illustrations. Thus, the scope of the present invention should not be limited to the specific illustrative structures described herein, but rather extends at least to the structures described by the language of the claims, and the equivalents of those structures. Any of the elements that are positively recited in this specification as alternatives may be explicitly included in the claims or excluded from the claims, in any combination as desired. Any of the elements or combinations of elements that are recited in this specification in open-ended language (e.g., comprise and derivatives thereof), are considered to additionally be recited in closed-ended language (e.g., consist and derivatives thereof) and in partially closed-ended language (e.g., consist essentially, and derivatives thereof). To the extent that there is any conflict or discrepancy between this specification as written and the disclosure in any document incorporated by reference herein, this specification as written will control.