WO2023018595A1

WO2023018595A1 - Respirator assembly with a changeable filter

Info

Publication number: WO2023018595A1
Application number: PCT/US2022/039392
Authority: WO
Inventors: Ronald L. Gerson
Original assignee: Louis M. Gerson Co.
Priority date: 2021-08-13
Filing date: 2022-08-04
Publication date: 2023-02-16

Abstract

A respirator filter assembly includes a detachable housing to encase, at least partially, a respirator cartridge attachable to a respirator mask. The detachable housing defines an interior volume and a cartridge-side opening to receive the respirator cartridge. The detachable housing includes a filter holding mechanism located within the interior volume. The respirator filter assembly also includes a replaceable filter secured to the detachable housing by the filter holding mechanism.

Description

RESPIRATOR AS SEMB LY WITH A CHANGEAB LE FILTER

Cross Reference to Related Applications

[001] This application claims priority to US Provisional Application No. 63/232,885, filed on August 13, 2021, the contents of which is hereby incorporated by reference in its entirety.

Background

[002] The present disclosure relates to respirators and face mask assemblies.

[003] A respirator is a device designed to protect the wearer from inhaling harmful dusts, fumes, vapors, or gases. Respirators are used to remove hazardous particles or vapors from the air and are typically used in situations such as construction or chemical cleanup where those hazardous materials can be found in high concentrations. Respirators come in a wide range of types and sizes used by the military, private industry, and the public. All respirators have some type of facepiece, or mask body held to the wearer's head with straps, a cloth harness, or some other method. The mask body of the respirator covers either the entire face (“Full Face Masks”) or the bottom half of the face including the nose and mouth (“Half-Masks”).

[004] Due to the potential dangers of inhaling hazardous particles or vapors, it is important that a properly functioning ventilation device (respirator) be used when operating in such hazardous environments. Cartridge filter assemblies can include filters that are disposed within a sealed housing. Such sealed housings have a cover that are ultrasonically sealed or glued to a main housing. Thus, different situations with different filtering requirements would ordinarily require the use of different cartridge units (with different filtering behaviors) for those different situations.

Summary

[005] The implementation described herein generally relate to a changeable filter assembly that allows the user to substitute various filters within a detachable housing that is attached to a cartridge of a respirator mask.

[006] In a general aspect of the invention, a respirator filter assembly includes a detachable housing to encase, at least partially, a respirator cartridge attachable to a respirator mask. The detachable housing defines an interior volume and a cartridge- side opening to receive the respirator cartridge. The detachable housing includes a filter holding mechanism located within the interior volume. The respirator filter assembly also includes a replaceable filter secured to the detachable housing by the filter holding mechanism.

[007] Embodiments of this aspect of the can include one or more of the following features. The replaceable filter includes a paper pleated filter incorporated within a gasketed peripheral member sized and shaped to fit within the detachable housing. The replaceable filter is selected from a plurality of available replaceable filters with different filtering characteristics

[008] The filter holding mechanism includes one or more of: a shelf element, extending from an interior wall of the detachable housing, on which the replaceable filter is placed, or a groove defined on the interior wall to received edge portions of the replaceable filter. In the case that a shelf element is included, it is further configured to sealingly attach to an exterior of the respirator cartridge.

[009] The detachable housing further includes a removeable housing cover attached to an edge of the detachable housing defining an outer opening across from the cartridgeside opening. The removable housing cover includes vent holes allowing passage of air through the outer opening towards the cartridge-side opening. The detachable housing further comprises a seal located proximate to the cartridge-side opening and extending from an inner wall of the detachable houses, the seal configured to sealingly attach to an exterior of the respirator cartridge.

[010] In some embodiments, the assembly includes the respirator mask and can also include the respirator cartridge. In embodiments in which the assembly includes a respirator cartridge, the respirator cartridge includes a cartridge body defining an inner cavity filled with particulate material, and a vented cartridge cover fitted on the cartridge body to enclose the particulate material filling the inner cavity. The particulate filter material can be an adsorbent particulate material selected from a group of activated charcoals, zeolites, molecular sieves, and alumina. The particulate material can be mixed with heterophil fibers.

[Oil] The respirator cartridge further includes a retaining structure spanning the inner cavity to retain the particulate material in a space defined between an inner wall of the cartridge body and an inner surface of the retaining structure closest to the inner wall of the cartridge body. The retaining structure can be a porous membrane to allow passage of air through the membrane and inhibit passage of the particulate filter material through the membrane and the vented cartridge cover can include a lattice structure defining vents.

[012] In another aspect of the invention, a respirator kit includes a respirator cartridge attachable to a respirator mask; replaceable filters, each of the replaceable filters including different filtering characteristics; and a detachable housing to encase, at least partially, the respirator cartridge, the detachable housing defining an interior volume and a cartridge-side opening to receive the respirator cartridge, wherein the detachable housing includes a filter holding mechanism located within the interior volume that receives a selected one of the plurality of replaceable filters.

[013] Embodiments of this aspect of the can include one or more of the following features. The respirator cartridge includes a cartridge body defining an inner cavity filled with particulate material, and a vented cartridge cover fitted on the cartridge body to enclose the particulate material filling the inner cavity. The filter holding mechanism includes one or more of: a shelf element, extending from an interior wall of the detachable housing, on which the selected one of the plurality of replaceable filters is placed, or a groove defined on the interior wall to received edge portions of the selected one of the plurality of replaceable filters. The detachable housing further comprises a seal located proximate to the cartridge- side opening and extending from an inner wall of the detachable housing, the seal configured to sealingly attach to an exterior of the respirator cartridge.

[014] Among other advantages, a respirator filter assembly and a respirator kit including such a respirator filter assembly allows for a user to substitute various filters within a detachable housing that is attached to a cartridge of a respirator mask.

[015] Other features and advantages of the invention are apparent from the following description, and from the claims.

Brief Description of the Drawings

[016] These and other aspects will now be described in detail with reference to the following drawings.

[017] FIG. 1 is a respirator assembly that includes a changeable filter. [018] FIG. 2 shows a cross-sectional view of a detachable housing attachable to a respirator cartridge.

[019] FIG. 3 is a perspective view of a removable housing cover for a detachable housing that can be attached to a respirator cartridge.

[020] FIG. 4 is a housing cover and a detachable structure with a replaceable filter.

[021] FIG. 5 shows different replaceable filters for use with the detachable housing used with a respirator cartridge.

[022] FIG. 6 is a diagram of an example respirator cartridge (canister) attachable to a detachable housing.

[023] FIG. 7 is a diagram of an example mask connected to two cartridges such as those shown in FIG. 1.

[024] FIG. 8a diagram of an example cartridge canister with a rounded body.

[025] FIG. 8b is a cross-sectional view of the cartridge depicted in FIG. 8a.

[026] Like reference symbols in the various drawings indicate like elements.

Description

[027] The implementations described herein are directed to systems, devices, and assemblies that include a replaceable (changeable) respirator filter that is typically disposed within a structure that is fitted on a respirator cartridge (cannister) used with respirator mask (an example of such a mask is the mask 110 shown in FIG. 1). The replaceable respirator filter allows the user to build or construct a filter assembly with desired filter components (to achieve a desire filtering performance). Thus, the user can use a respirator assembly for one application that requires a filter with a modest level of filtration (e.g., for spray painting protection), and use the same assembly, but with a different replaceable filter, for another use application requiring a higher level of filtration (e.g., when dealing with hazardous materials). A supplier of the replaceable filter assembly can thus provide filtration kits that include a detachable respirator housing to receive and hold the filter, along with various filters with different filtering capabilities (i.e., different filtering characteristics / attributes), and optionally a respirator cartridge (and possibly also a respiration mask) so that a user can assemble an appropriate filter combination rather than have to purchase separate cartridges for each application. Thus, the implementations described herein include a respirator filter assembly comprising a detachable housing to encase, at least partially, a respirator cartridge attachable to a respirator mask, the detachable housing defining an interior volume and a cartridge- side opening to receive the respirator cartridge, with the detachable housing including a filter holding mechanism located within the interior volume. The assembly further includes a replaceable filter secured to the detachable housing by the filter holding mechanism. Examples of the respirator assembly may also include the respirator cartridge and/or the mask to which the respirator cartridge is attached.

[028] More particularly, with reference now to FIG. 1, a respirator assembly 100 that includes a replaceable respirator filter is shown. The assembly 100 includes a filter mask 110 configured to receive two removable respirator cartridges 120 and 122 on each side of the mask. In other example embodiments, the mask may be configured to receive a single cartridge, or more than two cartridges. The cartridge 120 is shown in its assembled state while the cartridge 122 on is shown in a disassembled state (i.e., disconnected from its housing). The respirator cartridges 120 and 122 are configured to be attached to detachable housings 130 and 132, respectively, that encase (at least partially) the cartridges 120 and 122. As illustrated in FIG. 1, the housing 130 is attached (through a threading structure, through a sealing or gasket-type member) to the cartridge 120. In some embodiments, and as will be discussed in greater detail below, the detachable housings 130 and 132 are configured to be sealingly attached to their respective cartridges so that air cannot enter the vented cover of the cartridges other than through the replaceable filters that are fitted within the detachable housings,

[029] With reference now to FIG. 2, a cross-sectional diagram 200 is provided of an example detachable housing 210, which may be similar to either of the housings 130 or 132 shown in FIG. 1, with a removable housing cover 220 attached to the detachable housing 210 to cover an outer opening 234 of the detachable housing (that opening is referred to as the outer opening of the housing 210 because that is the opening that is farther away from the cartridge to which the removable housing is attached). Attachment of the cover 220 to the detachable housing 210 can be achieved through any number of attachment approaches. For example, a threading mechanism may be used to fit threads on an outer wall of the housing cover 220 to corresponding threads on an inner wall of the detachable housing 210. Alternatively, a rim on at least portions of an exterior surface of the housing cover (the rim is depicted in FIG. 2 as element 222) can be fit into a corresponding groove (not shown in FIG. 2) defined in an inner wall of the detachable housing 210 near the outer opening 234. In another embodiment, attachment of the housing cover 220 to the housing structure can be achieved by fitting the housing cover 220, which may be made of a deformable resilient material, into the outer opening 234 of the detachable housing 210 so that when a force applied to the cover to deform and compress it is ceased, the deformable cover expands and presses against the inner walls of the housing structure 210. In such embodiments, the rim 222 of the housing cover 220 rests on an outer edge 218 of the detachable housing 210. In the latter example implementation, the rim 222 also serves to define the depth to which the cover 220 is placed within the interior volume defined by the detachable housing 210 in that the rim 222 inhibits how far down the cover can be lowered by preventing further advancement once the rim 222 comes in contact with the edge 218 of the detachable housing 210.

[030] With reference to FIG. 3, a perspective view diagram of an example housing cover 300, which may be similar to the housing cover 220 of FIG. 2, is shown. The housing cover 300 includes a cover body 310 (e.g., one made from a deformable resilient material), and a rim 320, which may be similar to the rim 222 of FIG. 2. Also shown in FIG. 3 are vent holes 330 defined on a side surface 312 of the cover body 310. The vent holes 330 allow air to enter the cover and the detachable housing (when the cover 300 engages a detachable housing such as the housing 210 of FIG. 2) and to be directed via a replaceable / changeable filter disposed within the detachable housing.

[031] FIG. 4 is another embodiment of housing cover 400, but with vent hole 430 (covered with a grate 432) positioned on a main surface 412 of a cover body 410. FIG. 4 illustrates the housing cover disassembled (removed) from a housing 402 (which may be similar to the detachable housing 210 of FIG. 2) that includes a replaceable filter 440 disposed within the interior volume of the detachable housing 402. The replaceable filter 440 may be a paper pleated filter incorporated within a gasketed peripheral member that is sized and shaped to fit snugly within the housing. The gasketed peripheral member may be formed of a flexible elastomeric material such that it can be received within the detachable housing (e.g., using filter holder, as will be discussed in greater detail below) that is to be attached to the respirator cartridge.

[032] Turning back to FIG. 2, the detachable housing 210 defines an interior volume 230 and a cartridge-side opening 232 to receive the respirator cartridge (to at least partially encase it). Attachment to the respirator cartridge (e.g., the cartridges 120 or 122 of FIG. 1) can be achieved through a threaded structure provided on the exterior of the cartridge and the interior walls of the detachable housing (this example implementation is not shown in FIG. 2). Alternatively, as depicted in FIG. 2, attachment to the target cartridge can be achieve through a seal (gasket), such as a ring-shaped seal (or O-ring) 212 surrounding the cartridge-side opening 232 of the detachable housing 210. The seal 212, which can be made from resilient material (such as rubber) can thus be sealingly secured to the exterior of the respirator cartridge to substantially inhibit or prevent air from seeping between the interior walls of the detachable housing 210 and the exterior walls of the cartridge.

[033] As noted above, and as further shown in FIG. 2, the detachable housing 210 includes a filter holding mechanism located within the interior volume. In some examples, the filter holding mechanism includes a shelf element, such as a shelf 214, extending from an interior wall 216 of the detachable housing 210. The replaceable filter (not shown in FIG. 2 but one that may be similar to the filter 440 of FIG. 4) may be placed on the shelf 214. As noted, the replaceable filter may be of a size and shape that it snugly fits within the cross-sectional area within of the interior volume 230, as defined by the shelf 214 (as shown in FIG. 2, the walls of the detachable housing may be tapered, thus defining different cross-sectional areas at different vertical locations of the housing’s walls). In some embodiments, groove portions 217 may be defined along the inner wall 216 to receive outer edges of the replaceable filter disposed within the detachable housing (this may be done in conjunction with, or without, the shelf 214). Thus, in some examples, the filter holding mechanism includes one or more of, for example, a shelf element, extending from an interior wall of the detachable housing, on which the replaceable filter is placed, and/or a groove defined on the interior wall (or a portion thereof) of the detachable housing so as to receive edge portions of the replaceable filter.

[034] In embodiments in which a shelf 214 is used, the shelf 214 may be used to provide a further seal (gasket) to sealingly secure the detachable housing 210 to the respirator cartridges (such as the cartridges 120 and 122 of FIG. 1). Therefore, in some embodiments, the shelf 214 can serve the dual purpose of holding a replaceable / changeable filter and creating a seal (in addition to using the seal 212, or without using the seal 212). Like the seal 212, the shelf 214 may be a ring-shaped seal (or O-ring) positioned somewhere between (e.g., halfway) the outer opening 234 and the cartridgeside opening 232 of the detachable housing 210.

[035] As noted, the replaceable filter placed within the detachable housing may include a paper pleated filter incorporated within a gasketed peripheral member sized and shaped to fit snugly within the detachable housing. The replaceable filter is selected from a plurality of available replaceable filters with different filtering characteristics. FIG. 5 is a photo 500 of different filters 510, 512, 514, and 516 with substantially the same dimensions, but of different filtering characteristics. In operation, the housing cover (e.g., the cover 220 of FIG. 2) can be removed from its detachable housing (e.g., the housing 210 of FIG. 2) to place one of the available filters 510-516) in the housing using the particular filter holding mechanism that is included with the detachable structure. The selection of the filter to use may depend on the particular application for which a respirator mask is to be employed, and on the age of the current filter disposed within the detachable housing 210 (e.g., if the current replaceable filter has reached the end of its useful life). The use of the replaceable filter within the detachable housing attached to a respirator cartridge allows for a more diverse use of a respirator mask assembly for different application. Specifically, the respirator cartridge that is being used may include a relatively coarse filter covering the particulate material (adsorbent particulate material) within the cartridge. To adjust the filtering performance of the assembly (comprising the housing assembly, and the respirator cartridge), the proper replaceable filter is selected and placed into the detachable housing, the housing cover is attached to the detachable housing, and the now closed detachable housing assembly is attached to the respirator cartridge (cannister). The replaceable filter selected, along with the fixed filter within the cartridge can thus provide a controllably variable filtering performance that is determined based on the filtering characteristics of the replaceable filter and the filtering characteristics associated with the respirator cartridge.

[036] As discussed herein, the detachable housing is configured to attach to a respirator cartridge (or cannister), in a way that the housing encases (at least partially) the body of the cartridge, and generally forms a seal between the housing and the cartridge. With reference to FIG. 6, a front view diagram of an example respirator cartridge 600, which may be similar to any of the cartridges (120 or 122) depicted in FIG. 1, is shown. The cartridge 600 includes a cartridge body 603 defining an inner cavity (where the inner cavity is the space within the cartridge body 603) and a female connector 610 for connecting to a male inhalation port of a mask (such as the mask 110 or 700 of FIGS. 1 and 7).

[037] Particulate filter material (not shown in FIG. 6) such as an adsorbent particulate material selected from a group of activated charcoals, zeolites, molecular sieves, and alumina, are contained within the inner cavity defined by the cartridge body 603. In some embodiments, the particulate material may be an adsorbent material. In some embodiments, the particulate material may be mixed with heterophil fibers. The particulate filter material is further contained within a filter media retaining structure such as a mesh bag, container, or membrane (a portion of a membrane-type media retaining structure 612 is shown in FIG. 6). In practice, the filter media retaining structure can be made of other materials that do not inhibit air flow through the cartridge 600 and is typically constructed to be a non-woven web of material. The filter media retaining structure may have a relatively coarse filter configuration that, while preventing the particulate material from breaching the retaining structure (e.g., breaching a membrane) would let air pass through it for further filtering action by the adsorbent particulate material, with the filtered air then passing to the respirator mask. The coarse filtering action performed by the retaining structure is supplemented by potentially finer filtering action achieved by the replaceable filter within the detachable housing that attaches to the respirator cartridge. The supplemental filtering action is controllable in that the proper replaceable filter can be selected and placed within the detachable housing to achieve the desired level of filtering required for the particular application for which the respirator assembly is to be used (e.g., high / finer filtering action for applications involving operating in more dangerous and hazardous environments, and lower / coarser filtering action for application that are of lesser danger).

[038] The shape of the cartridge body 603 may be made, in some embodiments, to be curved (as shown, for example, in FIGS. 8a and 8b). The purpose of the curvature of the cartridge body 603 is such that when the cartridge is packed with particulate material according to the approach discussed in WO 2020/252004 Al (entitled “Systems and methods for centrifugal force-based canister,” filed June 10, 2020, the content of which is herein incorporated by reference in its entirety), centrifugal force is exerted on the cartridge 600, the particulate filter material may be packed more efficiently than if the cartridge body 603 were to have an angular shape. It is noted that one can take advantage of the curvature of the cartridge body 603 when imparting centrifugal force if centrifugal force is exerted on the cartridge 600 by rotating it about a vertical axis created by a retractable application pipe inserted into a fill opening (such as the fill opening 802 of FIGS. 8a and 8b).

[039] Once a housing cover with a desired replaceable filter is attached to a cartridge (e.g., a cartridge filled with particulate material to achieve desired density through the application of a centrifugal force in accordance with the approaches described in WO 2020/252004), the assembly can be fitted to a respirator mask. More particularly, FIG. 7 is a diagram of a mask 700 with two cartridges (canisters) 702 removably connected to the mask's inhalation ports. In order to increase airflow through the adsorbent media, internal ridges may project inwardly from the interior surface of the bottom side of vapor filter to promote distribution of the inhaled air over the entire surface area of the cartridges 702. The ridges may also apply pressure to the retaining fabric, thereby compacting the adsorbent media to prevent channeling or openings in the media, through which unfiltered air could otherwise pass. The ridges are spaced apart from each other to allow for a high degree of airflow throughout the cartridges 702. Further details regarding embodiments of a mask and various accompanying structures that may be fitted on the cartridges 702 are provided in U.S. patent publication No. 2008/0156329, entitled “Cartridge Respirator with Integral Filter Adaptor,” the content of which is hereby incorporated by reference in its entirety.

[040] Thus, in some example embodiments, the respirator assembly described herein may include a respirator cartridge, that is attachable to the detachable housing (as described above), and which includes a cartridge body defining an inner cavity filled with adsorbent particulate material, and a vented cartridge cover fitted on the cartridge body to enclose the adsorbent particulate material filling the inner cavity. The particulate filter material may be adsorbent particulate filter material selected from a group of activated charcoals, zeolites, molecular sieves, and alumina. The particulate material may be mixed with, in some embodiments, with heterophil fibers. The respirator cartridge may further include a retaining structure spanning the inner cavity to retain the particulate material in a space defined between an inner wall of the cartridge body and an inner surface of the retaining structure closest to the inner walls of the cartridge body. For example, the retaining structure may be a porous membrane to allow passage of air through the member and inhibit passage of the adsorbent particulate filter material through the membrane (i.e., a membrane that is impermeable to the particles of the particulate filter materials, but which allows air to permeate through the membrane or whichever retaining structure is used). The retaining structure may also extend to entirely encase or surround the particulate media (e.g., act as a net or a sac), or, alternatively, may include a separate structure to prevent particulate materials from exiting the cartridge through the port connecting the cartridge to the inlet port of the respirator mask. In some embodiments, the vented cartridge cover (e.g., the cover 704 depicted in FIG. 7) may include a lattice structure defining vents.

[041] In some situations, cartridges filled by systems such as the systems described in WO 2020/252004 can be made to have a rounded shape, thus increasing the available volume for packing particulate material for relative to the surface area of the exterior of the cartridges. It is noted that because the packing of the particulate material is achieved through application of centrifugal forces, rather than by pressing the particular material using the walls of the cartridges, a substantially flat-shaped housing for the canister is not needed. Referring to FIG. 8a, a diagram of an example cartridge 800 is depicted. The cartridge 800 is shown to have a curved body relative to the body structure of the cartridge 600 seen in FIG. 6. The cartridge 800 includes a curved body 803 defining an inner cavity 801, where the curved cartridge body 803 is shown to include a fill opening 802 at its top. The fill opening 802 is positioned such that a retractable application pipe can be inserted so as to fill the inner cavity 801 with particulate filter material (other filling mechanisms, and filling interfaces / adapters to interact with such filling mechanisms, may also be used). While the fill opening 802 is shown to be positioned at a top portion of the cartridge, the fill opening 802 may be located at other places on the exterior of the cartridge 800. A curved lattice 804 defines the curvature of the cartridge 800, as well as a series of vents through which filtered air can be passed to a mask.

[042] Further referring to FIG. 8a, the shape of the filter cartridge 800 is shown to have a curvature that is defined by a curvature in the lattice 804 in addition to a curvature in the outer wall 803. The resulting overall shape for the cartridge 800 is such that, when compared to the filter canister 600 shown in FIG. 6, the two cartridges have comparable height (length along the longitudinal axis extending from the canister’s top to its bottom), the cartridge 800 protrudes further along a transverse axis of the canister’s body. This gives the cartridge 800 a greater volume than the cartridge 600 shown in FIG. 6, for a relatively small increase of materials used to create the cartridge 800. A consequence of the volume increase of the cartridge 800 relative to cartridge 600 is that more particulate filter material (shown in FIG. 8b) can be contained within the inner cavity 801 of the cartridge 800.

[043] Referring to FIG. 8b, a cross-sectional view of the cartridge 800 shown in FIG. 8a is provided. The inner cavity 801 is shown to be the space between the outer wall 803 and the curved lattice 804. The outer wall 803 is shown to be shaped such that it fits securely into a slot 805a, where the slot 805a is formed as the interior space created by a circumferential lip 805b on the rim of the curved lattice 804. The seal formed by the outer wall 803 and the circumferential lip 805b is such that their coupling ensures that air can first flow through the lattice side of the canister body, into the inner cavity 801. In addition, a female connector 810 is affixed to the outer wall 803. The positioning of the female connector 810 in the outer wall 803 is chosen so as to facilitate air flow through the lattice 804 to an opening (not shown) created by the presence of the female connector 810 in the outer wall 803. [044] The detachable housing, an assortment of replaceable filters (each with different filtering characteristics and adapted for different tasks or application), and one or more cartridges may be provided to a user as a kit (the kit may also include a respirator mask). In such embodiments, the respirator kit may include a respirator cartridge attachable to a respirator mask, a plurality of replaceable filters, each of the replaceable filters including different filtering characteristics, and a detachable housing to encase, at least partially, the respirator cartridge, with the detachable housing defining an interior volume and a cartridge- side opening to receive the respirator cartridge. The detachable housing includes a filter holding mechanism located within the interior volume that receives a selected one of the plurality of replaceable filters. The respirator cartridge includes a cartridge body defining an inner cavity filled with adsorbent particulate material, and a vented cartridge cover fitted on the cartridge body to enclose the adsorbent particulate material filling the inner cavity. The filter holding mechanism may include one or more of, for example, a shelf element, extending from an interior wall of the detachable housing, on which the replaceable filter is placed, and/or a groove defined on the interior wall to received edge portions of the replaceable filter. In some embodiments, the detachable housing may further include a seal located proximate to the cartridge- side opening and extending from an inner wall of the detachable houses, with the seal configured to sealingly attach to an exterior of the respirator cartridge.

[045] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly or conventionally understood. As used herein, the articles “a” and “an” refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element. “About” and/or “approximately” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, encompasses variations of ±20% or ±10%, ±5%, or ±0.1% from the specified value, as such variations are appropriate in the context of the systems, devices, circuits, methods, and other implementations described herein. “Substantially” as used herein when referring to a measurable value such as an amount, a temporal duration, a physical attribute (such as frequency), and the like, also encompasses variations of ±20% or ±10%, ±5%, or ±0.1% from the specified value, as such variations are appropriate in the context of the systems, devices, circuits, methods, and other implementations described herein.

[046] As used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of’ or “one or more of’ indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C), or combinations with more than one feature (e.g., AA, AAB, ABBC, etc.). Also, as used herein, unless otherwise stated, a statement that a function or operation is “based on” an item or condition means that the function or operation is based on the stated item or condition and may be based on one or more items and/or conditions in addition to the stated item or condition.

[047] Although particular embodiments have been disclosed herein in detail, this has been done by way of example for purposes of illustration only and is not intended to be limiting with respect to the scope of the appended claims, which follow. Features of the disclosed embodiments can be combined, rearranged, etc., within the scope of the invention to produce more embodiments. Some other aspects, advantages, and modifications are considered to be within the scope of the claims provided below. The claims presented are representative of at least some of the embodiments and features disclosed herein. Other unclaimed embodiments and features are also contemplated.

Claims

What is claimed is:

1. A respirator filter assembly comprising: a detachable housing to encase, at least partially, a respirator cartridge attachable to a respirator mask, the detachable housing defining an interior volume and a cartridgeside opening to receive the respirator cartridge, wherein the detachable housing includes a filter holding mechanism located within the interior volume; and a replaceable filter secured to the detachable housing by the filter holding mechanism.

2. The assembly of claim 1, wherein the replaceable filter includes a paper pleated filter incorporated within a gasketed peripheral member sized and shaped to fit within the detachable housing.

3. The assembly of claim 1, wherein the replaceable filter is selected from a plurality of available replaceable filters with different filtering characteristics.

4. The assembly of claim 1, wherein the filter holding mechanism includes one or more of: a shelf element, extending from an interior wall of the detachable housing, on which the replaceable filter is placed, or a groove defined on the interior wall to received edge portions of the replaceable filter.

5. The assembly of claim 4, wherein the shelf element is further configured to sealingly attach to an exterior of the respirator cartridge.

6. The assembly of claim 1, wherein the detachable housing further includes a removeable housing cover attached to an edge of the detachable housing defining an outer opening across from the cartridge-side opening.

7. The assembly of claim 6, wherein the removable housing cover includes vent holes allowing passage of air through the outer opening towards the cartridge- side opening.

8. The assembly of claim 1, wherein the detachable housing further comprises a seal located proximate to the cartridge- side opening, and extending from an inner wall of the detachable houses, the seal configured to sealingly attach to an exterior of the respirator cartridge.

9. The assembly of claim 1, further comprising the respirator mask.

10. The assembly of claim 1, further comprising the respirator cartridge.

11. The assembly of claim 10, wherein the respirator cartridge includes a cartridge body defining an inner cavity filled with particulate material, and a vented cartridge cover fitted on the cartridge body to enclose the particulate material filling the inner cavity.

12. The assembly of claim 11, wherein the particulate filter material is an adsorbent particulate material selected from a group of activated charcoals, zeolites, molecular sieves, and alumina.

13. The assembly of claim 11, wherein the particulate material is mixed with heterophil fibers.

14. The assembly of claim 11, wherein the respirator cartridge further comprises a retaining structure spanning the inner cavity to retain the particulate material in a space defined between an inner wall of the cartridge body and an inner surface of the retaining structure closest to the inner wall of the cartridge body.

15. The assembly of claim 14, wherein the retaining structure is a porous membrane to allow passage of air through the membrane and inhibit passage of the particulate filter material through the membrane.

16. The assembly of claim 11, wherein the vented cartridge cover comprises a lattice structure defining vents.

17. A respirator kit comprising: a respirator cartridge attachable to a respirator mask; a plurality of replaceable filters, each of the replaceable filters including different filtering characteristics; and a detachable housing to encase, at least partially, the respirator cartridge, the detachable housing defining an interior volume and a cartridge-side opening to receive the respirator cartridge, wherein the detachable housing includes a filter holding mechanism located within the interior volume that receives a selected one of the plurality of replaceable filters.

18. The kit of claim 17, wherein the respirator cartridge includes a cartridge body defining an inner cavity filled with particulate material, and a vented cartridge cover fitted on the cartridge body to enclose the particulate material filling the inner cavity.

19. The kit of claim 17, wherein the filter holding mechanism includes one or more of: a shelf element, extending from an interior wall of the detachable housing, on which the selected one of the plurality of replaceable filters is placed, or a groove defined on the interior wall to received edge portions of the selected one of the plurality of replaceable filters.

20. The kit of claim 17, wherein the detachable housing further comprises a seal located proximate to the cartridge- side opening and extending from an inner wall of the detachable housing, the seal configured to sealingly attach to an exterior of the respirator cartridge.

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