Patent Publication Number: US-2007108136-A1

Title: Fluid filtration assembly

Description:
BACKGROUND  
      1. Field of the Invention  
      The invention relates to the filtration of fluids and, more particularly, to assemblies and related methods for the filtration of water and other beverages.  
      2. Related Art  
      Fluids are filtered in a variety of ways, and for different purposes. Fluid filtration or purification (“filtration” or “filtering”) serves to eliminate undesirable matter, such as contaminants and particulate matter, from a quantity of a fluid. This is done, for example, to improve the purity, quality, safety, taste, smell, or other properties of the fluid that is being filtered. Examples of fluid filtration include the filtering of water in order to prepare it for human consumption, or the filtering of a mixture of hot water and ground coffee beans in order to provide a coffee drink. Another example of fluid filtration is the filtering of a fuel in order to eliminate contaminants that may damage an engine or affect its operation or performance.  
      Many different assemblies and related methods are used to filter fluids. Some approaches, including distillation, centrifugation, and the use of antibodies, and others, are not practical for small-scale (i.e., consumer) filtration needs, especially relating to water or other beverages that are being prepared for human use. Simpler approaches that are suited to consumer water and beverage filtration fit into two general categories: (a) gravity operated; and (b) pressure operated.  
      Gravity-operated filtration typically involves a container having upper and lower compartments, and a filter located in between. Another embodiment of this type of filter uses an upper container (i.e., a bag) that may be positioned above, and is connected to, a filter (which is, in turn, connected to another container or fluid outlet). Unfiltered fluid is placed into the upper compartment that is located above the filter relative to the direction of gravitational force. The fluid passes through the filter at a rate of flow determined by gravity, the physical properties of the filter, and the physical properties of the fluid, among other factors. In general, it may take several minutes for a liter of water to flow through a filter of a typical consumer water filtration device of this type. Examples of devices of this type include those made or sold by Brita Products Company (an affiliate of The Clorox Company, Oakland, Calif., USA), and Pur (an affiliate of Proctor &amp; Gamble Company, Cincinnati, Ohio, USA). Other gravity-fed water filtration assemblies are made by Katadyn Produkte AG (Wallisellen, Switzerland), and Mountain Safety Research (Seattle, Wash., USA).  
      Pressure operated assemblies rely on a, pressurized source of a fluid, such as a home, office, or laboratory water line—including those that feed into a faucet, shower, or appliance, for example. In a pressure operated device, pressurized water is forced through a filter. Water coming out of the filter is then re-introduced back into a water supply line, exits through an outlet (faucet or head) of a device, or is made available for consumption or other use. With regard to water filtration, these types of assemblies are commonly used for residential and commercial water filtration. Examples of devices of this type include those made or sold by Amway Corporation (an affiliate of Alticor, Ada, Mich., USA), The Brita Products Company (an affiliate of The Clorox Company, Oakland, Calif., USA), Culligan International (Northbrook, Ill., USA), Everpure, Inc. (Hannover Park, Ill., USA), General Electric Company (Fairfield, Conn., USA), Kenmore (an affiliate of Sears Holdings Corporation, Hoffman Estates, Ill., USA), Multi-Pure International (Las Vegas, Nev., USA), Pur (an affiliate of The Proctor &amp; Gamble Company, Cincinnati, Ohio, USA), and Sun Water Systems, Inc. (Fort Worth, Tex., USA). In addition, pressurized sources of water (including steam) are used in devices for making beverages such as coffee. Examples of such devices are made or sold by Bialetti Industrie S.p.A. (Coccaglio, Italy), Black &amp; Decker (Towson, Md., USA), Braun (an affiliate of The Proctor &amp; Gamble Company, Cincinnati, Ohio, USA), Bunn-O-Matic Corporation (Springfield, Ill., USA), Cuisinart (Stamford, Conn., USA), Keurig Incorporated (Wakefield, Mass., USA), Krups (an affiliate of Groupe SEB, Cedex, France), and La Pavoni S.p.A. (Milan, Italy).  
      Pressure operated devices also include those wherein the pressurized water source is provided by manual operation. These devices include hand-pump type water filters, such as those used by campers and outdoor enthusiasts to filter or purify water from a stream or other source, as well as water filters used to modify a beverage. The latter devices include those known as “French presses,” and involve the manipulation of a filter in a manner that forces a filter through a fluid (ground coffee beans and hot water in this case). Straw-type devices wherein fluid is drawn through a filter by means of negative pressure are also noted as devices that enable water filtration by pressure-induced means. Examples of devices of this general type include those made or sold by Bialetti Industrie S.p.A. (Coccaglio, Italy), Bodum AG (Triengen, Switzerland), Bonjour Products (Napa, Calif., USA), Frieling USA, Inc. (Charlotte, N.C., USA), Katadyn Produkte AG (Wallisellen, Switzerland), Planetary Design (Missoula, Mont., USA), and Timolino, Inc. (Laguna Hills, Calif., USA).  
      Manually-operated filtration devices of the last type are described in U.S. Pat. No. 678,692 to Roth; U.S. Pat. No. 1,982,846 to Wales; U.S. Pat. No. 2,311,759 to Johnson; U.S. Pat. No. 5,932,098 to Ross; U.S. Pat. No. 6,324,966 to Joergensen; and, U.S. Pat. No. 6,964,223 to O&#39;Loughlin.  
      These are merely a few examples of the kinds of assemblies and methods that have been developed in attempts to provide for the filtration and purification of fluids.  
     SUMMARY  
      Assemblies and methods are disclosed for filtering fluids, including water, by means of multiple-pass filtration. In general, multiple-pass filtration enables a fluid to be filtered by two or more successive passes through an assembly.  
      In accordance with embodiments of the invention, a fluid filtration assembly comprises filtration means and one-way flow means. A volume of a fluid that is flowed through filtration means of the assembly two or more times undergoes multiple-pass filtration. Flow of the fluid may be accomplished, for example, by moving the assembly through the fluid, or by moving the fluid through the assembly. Either method of use the assembly to perform multiple-pass filtration of the fluid.  
      Embodiments of the invention provide novel benefits and enable devices and methods of use that incorporate multiple-pass filtration assemblies. For example, water cups, beverage containers, filtration pitchers, coffee-making devices, and other similar products may apply embodiments of assemblies and methods of use of the invention to provide high quality fluid filtration simply, reliably, and at low cost. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the drawings, closely related figures have the same number but different alphabetic suffixes.  
       FIG. 1A  shows a schematic representation of a multiple-pass filtration assembly and process.  
       FIG. 1B  shows a schematic representation of a single-pass assembly and process.  
       FIG. 2  shows a side cut-away view of an embodiment of the invention, comprising a structure having filtration means and one-way flow means.  
       FIG. 3A  shows a top view of an embodiment of a capsule with filtration means and one-way flow means.  
       FIG. 3B  shows a side cut-away view of the same embodiment.  
       FIG. 4A  shows a top view of another embodiment of a capsule with filtration means and one-way flow means.  
       FIG. 43  shows a side cut-away view of the same embodiment.  
       FIG. 5A  shows a top view of yet another embodiment of a capsule with filtration means and one-way flow means.  
       FIG. 5B  shows a side cut-away view of the same embodiment.  
       FIGS. 6A-6D  show a method of using embodiments of the invention.  
       FIGS. 7A-7D  show a method of using an embodiment of the invention.  
       FIG. 8  shows a side cut-away view of an embodiment of the invention having a moveable capsule and associated tube-like manipulation means.  
       FIG. 9  shows a side cut-away view of another embodiment of the invention having a moveable capsule and associated rod manipulation means.  
       FIG. 10  shows a side cut-away view of yet another embodiment of the invention having a moveable capsule and associated rod manipulation means.  
       FIG. 11  shows a side cut-away view of yet another embodiment of the invention having a fixed capsule and fluid manipulation means.  
       FIG. 12  shows a side cut-away view of yet another embodiment of the invention having a filtration means and one-way flow means that are integrated with a structure of a vessel, and fluid manipulation means.  
       FIG. 13  shows a side cut-away view of yet another embodiment of the invention having a filtration means and one-way flow means that are integrated with a structure of a vessel, and fluid manipulation means. 
    
    
     DRAWING NUMERAL MEANINGS  
     
       
         
           
               
               
             
               
                   
               
               
                   
               
               
                 Drawing 
                   
               
               
                 Numeral 
                 Meaning 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1 
                 Assembly 
               
               
                 5 
                 Single-pass filter device of the prior art 
               
               
                 6 
                 Single pass filter device filter element 
               
               
                 10 
                 Capsule 
               
               
                 11 
                 Capsule first side 
               
               
                 12 
                 Capsule second side 
               
               
                 13 
                 Capsule peripheral wall 
               
               
                 14 
                 Capsule first side opening 
               
               
                 15 
                 Capsule second side opening 
               
               
                 20 
                 Filtration means 
               
               
                 21 
                 Filtration channel 
               
               
                 30 
                 One-way flow means 
               
               
                 31 
                 One-way flow channel 
               
               
                 40 
                 Manipulation means 
               
               
                 50 
                 Vessel 
               
               
                 60 
                 Fluid 
               
               
                 70 
                 Representation indicating a first direction of 
               
               
                   
                 movement of manipulation means 
               
               
                 71 
                 Representation indicating a second direction of 
               
               
                   
                 movement of manipulation means 
               
               
                 72 
                 Representation indicating a direction of flow of a 
               
               
                   
                 fluid through a filtration channel 
               
               
                 73 
                 Representation indicating a direction of flow of a 
               
               
                   
                 fluid through a one-way flow channel 
               
               
                   
               
            
           
         
       
     
     DETAILED DESCRIPTION  
     Introduction  
      In general, multiple-pass filtration means the filtration of a generally fixed volume a fluid (i.e., not a constant flow or uninterrupted stream) that occurs when the fluid, or a portion of a volume of the fluid, is passed through the same assembly two or more times.  
      As will be described in more detail below, embodiments of the invention have advantages including: 
          (1) Providing a fluid filtration assembly that enables multiple-pass filtration of a fluid;     (2) Providing a fluid filtration assembly that enables progressive filtration of a fluid by means of two or more passes of the fluid through such an assembly;     (3) Providing a fluid filtration assembly that enables a user to control the degree of filtration of a fluid;     (4) Providing a fluid filtration assembly that enables other novel fluid filtering devices;     (5) Providing a fluid filtration assembly that may be incorporated into a water filtering device;     (6) Providing a fluid filtration assembly that may be incorporated into a coffee-making device; and     (7) Providing a fluid filtration assembly that may be incorporated into a wide range of containers.        

      Embodiments of the invention provide assemblies, methods, and related devices for filtering fluids, including water, by means of multiple-pass filtration. Multiple-pass filtration enables a fluid to be filtered two or more times by successive passes through the same assembly, i.e., assembly  1 . By contrast, single-pass type filtration does not provide for recirculation (cycling) of fluid through the same device multiple times.  
      The general concept of multiple-pass filtration is shown in  FIG. 1A .  FIG. 1A  shows a representation of a generic multiple-pass filtration assembly  1 . In  FIG. 1A , the arrow (A-&gt;B-&gt;C) shows a path of flow of a fluid through the generic multiple-pass filtration assembly  1 . A fluid is caused to flow through filtration means  20  of the assembly  1  once (A-&gt;B), and then is caused to circulate back through another element of the assembly (B-&gt;C) in order to flow through filtration means  20  of the same assembly  1  at least one more time (C-&gt;D). In other words, the fluid is circulated (or cycled) two or more times through such a multiple-pass filtration assembly to cause multiple-pass filtration of the fluid. By contrast,  FIG. 1B  shows a representation of a single-pass filter device  5  of the prior art. In  FIG. 1B , the arrow (Y-&gt;Z) represents the path of flow of a fluid through a filter  6  of the single-pass filter device  5  of the prior art.  
      Importantly, multiple-pass filtration occurs when fluid flows through an assembly two or more times, and does not equate with the number of discrete filters or filtration means of an assembly of either type (multiple-pass or single pass, either of which may have one or many filters or filtration means). In other words, an assembly of either type may have one or more discrete filters or filtration means; however, the number of filters or filtration means of an assembly does not imply multiple-pass filtration of fluid. Only re-circulation of fluid through an assembly two or more times constitutes multiple-pass filtration.  
      Fluids that may be used in conjunction with embodiments of the invention include any fluid, including liquids and gasses. Examples of fluids that may be filtered using embodiments of the invention include water, coffee, tea, fuel, oil, and air. In particular, embodiments of the invention may be used to filter water or beverages for human consumption.  
     Capsule  
      Embodiments of the invention may be constructed of a capsule (also referred to as a “capsule structure”)  10  that is a structure that serves as a physical support for filtration means  20  and one-way flow means  30 .  
       FIG. 2  shows a side cut-away view of a generic assembly  1 . In  FIG. 2 , capsule  10  has filtration means  20  and one-way flow means  30 . Capsule  10  is positioned within (a column of) a fluid  60  located within a vessel (also referred to as a “container”)  50 . In general, fluid  60  is caused to flow through filtration means  20  of capsule  10  of assembly  1  a first time (one possible path of flow of fluid  60  through filtration means  20  is represented by arrow  72 ); then, at least a portion of fluid  60  is cycled (circulated) back through capsule  10  by means of one-way flow means  30  (one possible path of flow of fluid  60  through one-way flow means  30  is represented by arrow  73 ); then, at least a portion of fluid  60  is flowed back through filtration means  20 . Each pass through filtration means  20  constitutes a cycle. A functional combination of filtration means  20  and one-way flow means  30  enables multiple-pass filtration of fluid  60 . Two or more cycles cause multiple-pass filtration of fluid  60 .  
      Notably, embodiments of assemblies  1  enable multiple-pass filtration of fluid  60  so long as fluid  60  may be caused to flow back and forth through capsule  10 . This may be accomplished, for example, by moving capsule  10  through fluid  60 , or by moving fluid  60  through capsule  10 . For example, capsule  10  shown in  FIG. 2  may be moved up and down within fluid  60  located in vessel  50 . Alternatively, capsule  10  shown in  FIG. 2  may be in a fixed position (i.e., in relation to vessel  50 ), attached to vessel  50 , for example, and fluid  60  may be caused to move back and forth through capsule  10 . Either way, assembly  1  enables multiple-pass filtration of fluid  60 .  
      The shape, size, profile, and other features of assembly  1  may vary significantly; however, one embodiment of assembly  1  is a capsule  10 , which combines filtration means  20  and one-way flow means  30  to enable multiple-pass filtration.  
      One embodiment of assembly  1  is shown in  FIGS. 3A and 3B .  FIG. 3A  shows a top view of an embodiment of assembly  1 . Assembly  1   a  has a rectangular-shaped capsule  10   a , first side  11   a , first side openings  14   a , peripheral wall  13   a , a single filtration means  20   a  within a single filtration channel  21   a , and a single one-way flow means  30   a  within a single one-way flow channel  31   a .  FIG. 3B  shows a side cut-away view of this embodiment of assembly  1  shown in  FIG. 3A .  
      Another embodiment of assembly  1  is shown in  FIGS. 4A and 4b .  FIG. 4A  shows a top view of an embodiment of assembly  1 . Assembly  1   b  has a round-shaped capsule  10   b , first side  11   b , multiple first side openings  14   b , peripheral wall  13   b , and a single, centrally-positioned one-way flow means  30   b  within a single, centrally-positioned one-way flow channel  31   b .  FIG. 4   b  shows a side view of this embodiment of assembly  1  shown in  FIG. 4A , including filtration means  20   b  positioned within filtration channel  21   b.    
      Yet another embodiment of assembly  1  is shown in  FIGS. 5A and 5B .  FIG. 5A  shows a top view of this embodiment of assembly  1 . Assembly  1   c  has a generally square-shaped capsule  10   c , first side  11   c , first side openings  14   c , three discrete filtration means  20   c , each positioned within its own filtration channel  21   c , and two discrete one-way flow means  30   c , each positioned within its own one-way flow channel  31   c .  FIG. 5   b  shows a side view of this embodiment of the assembly  1  shown in  FIG. 5A .  
      Dimensions of assembly  1  may vary significantly. In one embodiment, for example, a cross-sectional dimension is between 10 and 100 cm. In another embodiment, for example, a cross-sectional dimension is between 1 and 1000 cm. In one embodiment, for example, the thickness of capsule  10  is between 1 and 10 cm. In another embodiment, for example, the thickness of capsule  10  is between 0.1 and 500 cm. First side openings  14  and second side openings  15  may also vary widely in size and shape, and combinations of different sizes and shapes are possible. For example, one embodiment of assembly  1  has capsule  10  having a circular cross-section, is 20 cm diameter, 3 cm thick, includes a central one-way flow channel  30  that is 5 cm diameter, and further includes 100 circular first side  11  and second side  12  openings of 0.1 cm diameter each.  
      A capsule may be manufactured of any one or more of a range of materials, including plastic, metal, glass, or other natural or synthetic materials, or combinations of these. A capsule may include one or more interior walls (dividers) to form compartments or enhance its structural rigidity. A capsule may be manufactured in a variety of ways. A capsule may be manufactured as a single piece, or multiple pieces that are assembled. A capsule may be formed, molded, or machined, for example. In one embodiment, for example a capsule is injection molded in two pieces, a bottom piece that includes spaced interior walls, and a top cover piece; filtration means and one-way flow means are positioned into the bottom piece; and the pieces are then assembled into a final assembly of the invention.  
      It is noted that embodiments of assemblies relate generally to a novel combination of filtration means and one-way flow means in order to enable multiple-pass filtration of a fluid. Such means may be combined using any capsule or any other structure that combines filtration means and one-way flow means. For example, filtration means  20  and one-way flow means  30  may be built into the sidewall of a cup or mug. In such an embodiment, a part of the structure of such a vessel would also serve as the structure that combines filtration means  20  and one-way flow means  30 , and enables a functional combination of these elements.  
     Filtration Means  
      In general, filtration means is any structure or process that enables filtering of a fluid. Fluid may be filtered, for example, to improve its purity, quality, safety, taste, smell, or other characteristics. Examples of contaminants or matter that may be filtered by embodiments of filtration means include: alachlor, atrazine, benzene, carbofuran, carbon tetrachloride, chlorobenzene, chlorine, dibromide, dibromochloropropane, dichlorobenzenes, dichloroethane, dichloroethylene, dinoseb, endrin, ethlybenzene, ethylene heptachlor, hexachlorobutadiene, hexachlorocyclopentadiene, lead, lindane, methoxychlor, methyltertbutylether, pentachlorophenol, simazine, styrene, tetrachloroethane, tetrachloroethlyene, toluene, 2,4,5-TP, trichlorobenzene, trichloroethanes, bromodichloromethane, bromoform, chloroform, chlorodibromomethane, xylenes, Cryptosporidium, and Giardia. These compounds or organisms are examples of those that may be found in drinking water.  
      Filtration means  20  may be any material or process that filters fluid  60  in a desired manner, i.e., is capable of reducing or eliminating some or all of contaminants from fluid  60 . Filtration means  20  may be made of a material (filtration media) such as carbon or paper, for example. In general, filtration means  20  may eliminate contaminants from fluid  60 , as fluid  60  is passed through the material. Filtration means  20  may, for example, be made of block carbon or activated carbon. Filtration means  20  may, for example, include an ion exchange resin. Filtration means  20  may, for example, include a microfilter. Filtration means  20  may be made of one material, or a combination of materials, such as in the case of a multimedia filter that provides for both physical and chemical filtration of fluid  60 . In one embodiment, filtration means  20  is a multimedia filter that includes block carbon and other constituents. Filtration means  20  may be a filter material or combination of filter materials that is enclosed in a filtration means unit, whereby the entire unit is replaceable, i.e., a cartridge that may be inserted and removed from a capsule  10 . This may be desirable since most filters have a life, and it may be useful to replace filtration means  20  in lieu of replacing the entire capsule  10  or assembly  1 .  
     One-Way Flow Means  
      One-way flow means is any structure or process that enables substantially unidirectional flow of fluid. For example, one-way flow means  30  may be a one-way valve. Such a valve may have leaves that move or flex to permit the flow of fluid  60  in one direction through the valve, but prevent the flow of the fluid  60  in an opposite direction through the valve. One-way flow means  30  may be made of deformable materials such as flexible plastic or rubber for example, or inflexible materials such as a stiff plastic or metal (possibly forming a hinge or other mechanism), or any combination of these or other materials. In one embodiment, one-way flow means  30  is a valve having three leaves that are made of a flexible plastic material. In another embodiment, one-way flow means  30  is trap door. In yet another embodiment, one-way flow means  30  is a generally fixed structure, such as a containment space, that enables fluid  60  to be (re)positioned into the space in order to facilitate a subsequent round of filtration of the fluid  60 . For example, an embodiment of the invention may be used by lowering one-way flow means  30  (comprising a containment space for holding a fluid) into fluid  60  to provide one-way flow of fluid  60  and circulation of fluid  60  back through filtration means  20 . In this last example, fluid  60  may flow around a structure, rather than through it.  
     Peripheral Wall  
      A peripheral wall (also referred to as a “side wall”) is an element of capsule  10  that, in one embodiment, facilitates movement of capsule  10  relative to vessel  50  containing fluid  60 . In such an embodiment, sides wall  13  is intended to facilitate secure movement of capsule  10  within (i.e., relative to the inside walls of) vessel  50 . In such an embodiment, peripheral wall  13  is straight (oriented at a right angle relative to the top and bottom surfaces of capsule  10 ) in order to enable secure (touching) direct contact with the inside walls of vessel  50  within which capsule  10  resides and moves. In other words, peripheral wall  13  is intended to substantially engage the interior surface, or inside wall or surface, of a chamber of vessel  50  in a manner that allows capsule  10  to slide up or down within such a chamber. Peripheral wall  13  may be made of the same or a different material as capsule  10 . Peripheral wall  13  may also be modified in any of a variety of ways. Examples of possible modifications include: surface texture, surface coating, rings (i.e., seal or gasket), or indentations. Whether or not modified, peripheral wall  13  may serve any one or more of the following purposes: a) promote stability of capsule  10  during movement of the capsule  10  relative to a chamber of vessel  50 ; b) promote a secure seal between capsule  10  and the inside wall of a vessel  50  in order to prevent or minimize undesirable flow (leakage) of fluid  60  around capsule  10  in the space between the capsule  10  and the inside wall of vessel  50 ; and  3 ) to facilitate movement (displacement or sliding) of capsule  10  relative to an inside wall of vessel  50 . In one embodiment of the invention, capsule peripheral wall  13  (a) provides stability of the capsule  10  as it is moved up and down within a chamber of vessel  50 , (b) provides a tight seal that prevents fluid  60  from by-passing filtration means  20 , and (c) facilitates sliding movement of the capsule  10  relative to the inside wall of the chamber of vessel  50 . Stability may also be achieved or enhanced by other means, such as manipulation means  40 , as described below.  
     Manipulation Means  
      Manipulation means (also referred to as “propulsion means”) includes any structure or process that causes fluid to flow through a capsule of an assembly. Manipulation means  40  may manipulate or move either capsule  10  or fluid  60 .  
      Manipulation means  40  that may move capsule  10  may include sticks, rods, and posts, for example. Another manipulation means  40  that may move capsule  10  is a tube-like structure that, for example, is connected with capsule  10  near or at the peripheral wall  13  of an embodiment of capsule  10 . Any of these manipulation means  40  may take any of a variety of shapes, sizes and forms. Manipulation means  40  that facilitate movement of capsule  10  may be made of a wide range of materials, including metal or plastic, or a combination of these or other materials. Manipulation means  40  of this type may be connected to a capsule  10  using an adhesive, engagement means, or a welding process, for example, or may be an integral part of capsule  10 .  
      Manipulation means  40  that facilitate movement of capsule  10  are connected to capsule  10  in order to displace capsule  10  in a desired manner. For example, moving manipulation means  40  of this type up relative to a vessel  50  displaces an associated capsule  10  up; moving manipulation means  40  of this type down relative to a vessel  50  displaces an associated capsule  10  down, i.e., further into vessel  50 .  
      Manipulation means  40  may also be any structure or process that moves fluid  60  in order to cause fluid  60  to flow through an embodiment of capsule  10 . Such manipulation means  40  may include any structure or process that is capable of altering a volume of a space of a vessel  50 , or otherwise causes fluid  60  to flow through capsule  10 . For example, manipulation means  40  of this type may be a deformable part of a vessel  50 , such as a depressible material, or a piston associated with vessel  50 .  
      Manipulation means  40  may also be remote, such as a magnet-controlled piston or other structure, or may even be the heating or cooling of fluid  60  to cause its flow through an embodiment of capsule  10  (i.e., the transformation of water into steam—and then back into water—that causes the water to expand and condense in a way that may cause it to flow back and forth through capsule  10 ).  
      An embodiment of assembly  1  may use multiple manipulation means  40 . For example, an embodiment of assembly  1  may include a first manipulation means (such as a post with a handle) to enable manual lifting of capsule  10 , and a second manipulation means (such as a spring) to cause capsule  10  to move in an opposite direction through fluid  60 . Another embodiment may have manipulation means  40  that engages a piston (and causes fluid  60  to move through capsule  10 ), and second manipulation means, such as a spring (to withdraw the piston and cause fluid  60  to move in an opposite direction through capsule  10 ). Other combinations of manipulation means are possible.  
      In general, manipulation means  40  cause the flow of fluid  60  through an embodiment of assembly  1 , irrespective of any particular design or method of operation.  
     Multiple-Pass Filtration  
      The progressive filtering of fluid to ever-greater degrees by means of two or more passes of fluid through filtration means of the same device is “multiple-pass filtration.” 
      For example, if a filter removes 90% of contaminants from fluid in a first pass, it should eliminate 90% of the remaining contaminants in a second pass, 90% of the remaining contaminants in a third pass, etc. After a first pass, 90% of the initial contaminants should be eliminated. After a second pass of the same fluid, 99% of the initial contaminants should be eliminated. After a third pass of the same fluid, 99.9% of the initial contaminants should be eliminated, and so on.  
      Even a filter that only removes 50% of contaminants in each filter pass (cycle) may be capable of eliminating 99.99% of contaminants in a quantity of fluid in about 15 cycles.  
      These are examples of one of the many benefits of multiple-pass filtration—a process that removes more and more of the contaminants from fluid by means of multiple (repeat) passes through the same filter. Multiple-pass filtration enables the use of less filtration material (medium) per assembly. One benefit of this is that it enables lower filter resistance. Another benefit of multiple-pass filtration is that it enables a wide range of novel water and fluid filtration devices.  
      The various embodiments of assemblies  1  enable multiple-pass filtration of fluid  60 . For example, multiple-pass filtration occurs when fluid  60  flows through filtration means  20  of an embodiment of the invention a first time, then flows through one-way flow means  30  of an embodiment of the invention, and is then allowed to flow back through filtration means  20  at least one more time. Each pass of fluid  60  through filtration means  20  constitutes a “cycle.” Two or more cycles constitute multiple-pass filtration. A user may perform a greater number or cycles in order to achieve a greater degree of filtration of fluid  60 .  
      In general, a cycle is enabled by one-way flow means  30  producing a relatively high resistance to fluid  60  flow from one direction (i.e., one side of capsule  10 ), but not an opposite direction (i.e., the other side of capsule  10 ). When capsule  10  of assembly  1  is moved into fluid  60 , or fluid  60  is forced into capsule  10  from a first direction, fluid  60  will flow preferentially through filtration means  20  (due to the high resistance to flow imposed by one-way flow means  30 ); when capsule  10  is moved out of fluid  60 , or fluid  60  is forced into capsule  10  from an opposite direction, fluid  60  will flow preferentially through one-way flow means  30  (due to relatively lower resistance that encourages preferential flow through one-way flow means  30  versus filtration means  20 ). Note that the terms “up” and “down” are used for descriptive purposes only, and may be reversed or changed, as appropriate, depending on the orientation of capsule  10  (i.e., filtration means  20  and one-way flow means  30 ), or the orientation of a device comprising assembly  1  of the invention.  
      In an embodiment of the invention, fluid  60  entering capsule  10  from a first direction will flow either substantially or completely through filtration means  20 , and fluid  60  entering capsule  10  from an opposite direction will flow either substantially or completely through one-way flow means  30 . Flowing fluid  60  back and forth through assembly  1  causes multiple-pass filtration of fluid  60 .  
      In general, multiple-pass filtration may be accomplished by embodiments of assembly  1  in either of two ways. First, an embodiment of assembly  1  may be moved (back and forth, for example) through fluid  60 . Second, fluid  60  may be moved (back and forth) through assembly  1 . Whether assembly  1  is moving or fixed relative to other structures (i.e., vessel  50 ), it is the relative movement of assembly  1  and fluid  60  that causes filtration. The techniques disclosed herein are independent of the manner in which assembly  1  is used—whether an embodiment of assembly  1  is being moved through fluid  60 , or fluid  60  is being moved through an embodiment of assembly  1 . Various methods of use fall within the scope of the invention. Assembly  1  should not be discriminated vis-à-vis its movement through fluid, or the movement of fluid through it.  
     Methods of Use  
      As described, an embodiment of assembly  1  may be either moveable through fluid  60 , or fluid  60  may be moveable through an embodiment of assembly  1 .  
      One embodiment of the invention includes capsule  10  that may be moved through fluid  60  two or more cycles to cause multiple-pass filtration. In the case of such an embodiment that is moveable through fluid  60 , a method of using such an embodiment includes the steps of: 
          (1) Positioning an embodiment of assembly  1  within vessel  50  filled with fluid  60 , as shown in  FIG. 6A ;     (2) Moving assembly  1  in a direction (i.e., down) that causes fluid  60  to pass through filtration means  20 , and that filters fluid  60 , as shown in  FIG. 6B  (arrow  70   x  represents a direction of movement of assembly  1 , and arrow  72   x  represents a direction of concurrent flow of fluid  60  through filtration means  20 ).  FIG. 6C  shows assembly  1  in a resting position at the bottom of vessel  50 ;     (3) Moving assembly  1  in an opposite direction (i.e., up) to cause fluid  60  to pass through one-way flow means  30 , as shown in  FIG. 6D  (arrow  71   x  represents a direction of movement of assembly  1 , and arrow  73   x  represents a direction of concurrent flow of fluid  60  through one-way flow means  30 );     (4) Repeating step 2 (or steps 2 and 3), at least once, in order to cause multiple-pass filtration and achieve a desired level of filtration of fluid  60 .        

      In the case of an embodiment of assembly  1  that is moveable through fluid  60 , another method of using such an embodiment includes the steps of: 
          (1) Pouring fluid  60  into vessel  50  that has assembly  1  of an embodiment of the invention near its bottom, as shown in  FIG. 6   c;       (2) Moving assembly  1  in a first direction (i.e., up) to cause fluid  60  to pass through one-way flow means  30 , as shown in  FIG. 4   d  (arrow  71   x  represents a direction of movement of assembly  1 , and arrow  73   x  represents a direction of concurrent flow of fluid  60  through one-way flow means  30 ).  FIG. 6A  shows assembly  1  in a resting position near the top of vessel  50 ;     (3) Moving assembly  1  in a second direction (i.e., down), opposite to a first direction, to cause fluid  60  to pass through filtration means  20 , and to filter fluid  60 , as shown in  FIG. 6   b  (arrow  70   x  represents a direction of movement of assembly  1 , and arrow  72   x  represents a direction of concurrent flow of fluid  60  through filtration means  20 );     (4) Repeating steps 2 and 3, at least once, in order to cause multiple-pass filtration and achieve a desired level of filtration of fluid  60 .        

      Another embodiment of assembly  1  has a capsule  10  that remains in a relatively fixed position (i.e., relative to a vessel  50 ) and has fluid  60  flowed through it two or more cycles in order to cause multiple-pass filtration. In the case of such an embodiment that has fluid  60  moved through it, a method of using such an embodiment includes the steps of: 
          (1) Applying a force to cause at least a portion of fluid  60  to flow through filtration means  20 , as shown in  FIG. 7A  (arrow  70   y  represents a direction of movement of assembly  1 , and arrow  72   y  represents a direction of concurrent flow of fluid  60  through filtration means  20 ).  FIG. 7B  shows fluid  60  in a steady state after it has flowed through filtration means  20 ;     (2) Releasing or reversing the force applied in Step  1  in order to cause fluid  60  to flow through one-way flow means  30 , as shown in  FIG. 7C  (arrow  71   y  represents a direction of movement of assembly  1 , and arrow  73   y  represents a direction of concurrent flow of fluid  60  through one-way flow means  30 ).        

       FIG. 7D  shows fluid  60  in a steady state after it has flowed through one-way flow means  30 ; 
          (3) Repeating step 1 (or steps 1 and 2), at least once, in order to cause multiple-pass filtration and achieve a desired level of filtration of fluid  60 .        
      Another method of using this type of an embodiment of assembly  1  includes the steps of: 
          (1) Applying a force to cause fluid  60  to flow through one-way flow means  30 , as shown in  FIG. 7C  (arrow  71   y  represents a direction of movement of assembly  1 , and arrow  73   y  represents a direction of concurrent flow of fluid  60  through one-way flow means  30 ).  FIG. 7D  shows fluid  60  in a steady state after it has flowed through one-way flow means  30 ;     (2) Releasing or reversing the force applied in Step 1 in order to cause fluid  60  to flow through filtration means  20 , as shown in  FIG. 7A  (arrow  70   y  represents a direction of movement of assembly  1 , and arrow  72   y  represents a direction of concurrent flow of fluid  60  through filtration means  20 ).  FIG. 7B  shows fluid  60  in a steady state after it has flowed through filtration means  20 ;     (3) Repeating steps 1 and 2, at least once, in order to cause multiple-pass filtration and achieve a desired level of filtration of fluid  60 .        

      The terms “up” and “down” are used for descriptive purposes only; in actual use, the orientation of a capsule or vessel may be reversed. Consequently, the method of use of an embodiment would be adapted, as appropriate.  
      Assemblies implemented in accordance with embodiments of the invention and the methods of use described above introduce several benefits. One benefit is the enablement of multiple-pass filtration of a fluid. Another benefit is the ability to make and use devices that incorporate embodiments of the invention to provide a range of new inventions that enable superior filtration of a fluid. Examples of such devices include vessels, drinking cups, mugs, water filtering containers, coffee-making devices, tea-making devices, and more. Several such embodiments that apply the invention are described in the following section.  
     REPRESENTATIVE EMBODIMENTS  
      In general, various embodiments of assemblies of the invention may be associated with a wide range of devices in order to enable multiple-pass filtration of a fluid. A few examples of devices that may incorporate embodiments of assemblies of the invention include: vessels, drinking cups, mugs, water filtration containers, portable drinking containers, coffee presses, tea making devices, and other similar products.  
      Several embodiments of devices that incorporate various embodiments of assemblies of the invention are described. In all of the embodiments described, a fluid may be moved through assembly  1  of an embodiment of the invention by manipulation means  40  (that either move assembly  1 , or move fluid  60 ) in order to enable multiple-pass filtration.  
       FIGS. 8-10  show representative embodiments of devices that incorporate embodiments of assemblies  1  of the invention along with manipulation means that enable the movement of a moveable capsule through fluid.  
       FIG. 8  shows a side cut-away view of vessel  50   d , such as a drinking cup. An embodiment of assembly  1  is moveably positioned in vessel  50   d , and includes capsule  10   d  (with filtration means and one-way flow means that are not shown) and associated tube-like manipulation means  40   d . In the embodiment shown in  FIG. 8 , a user would raise or lower manipulation means  40   d  to move capsule  10   d  through fluid, such as water. By moving manipulation means  40   d  and, by association, capsule  10   d  up and down according to a method of use of such an embodiment, this enables multiple-pass filtration of fluid. Such an embodiment may be used, for example, to filter water for human consumption. Such an embodiment may also be used, for example, to filter a composition of hot water and ground coffee beans, in order to provide a coffee drink that is ready for consumption. Tube-like manipulation means  40   d  shown in  FIG. 8  provide access to the fluid by means of an open top, and enable the addition of ingredients such as cream or sugar. The open top provided by manipulation means  40   d  also allows a user to consume a beverage directly from vessel  50   d . Capsule  10   d  may be permanently attached to manipulation means  40   d , or temporarily attached to manipulation means  40   d . If temporary, used capsule  10   d  may be detached and discarded, and new capsule  10   d  may then be attached. Also, filtration means of such an embodiment may be permanently attached to capsule  10   d , or temporarily attached to capsule  10   d . If temporary, used filtration means may be detached and discarded, and new filtration means may then be attached. An embodiment of the device generally depicted in  FIG. 8  may be used, for example, as a drinking cup, filtration container, coffee-making device, or tea-making device.  
       FIG. 9  shows a side cut-away view of another vessel  50   e , such as a water container. Another embodiment of assembly  1  is moveably positioned in vessel  50   e , and includes capsule  10   e  with filtration means and one-way flow means, and associated rod manipulation means  40   e . In the embodiment shown in  FIG. 8 , a user would raise or lower manipulation means  40   e  (possibly with the aid of a handle like the one shown in  FIG. 8 ) to move assembly  1  through fluid, such as water. By moving manipulation means  40   e  and, by association, capsule  10   e  up and down according to a method of use of the invention, this causes multiple-pass filtration of fluid. An embodiment of the device generally depicted in  FIG. 9  may be used, for example, to filter water for drinking purposes. Such an embodiment may also be used, for example, to filter a composition of hot water and ground coffee beans, in order to provide a coffee drink that is ready for consumption. Rod-like manipulation means  40   e  shown in  FIG. 9  provide a structure that may be positioned through a lid of a vessel  50   e , as shown in  FIG. 9 . Capsule  10   e  of such an embodiment may be permanently attached to manipulation means  40   e , or temporarily attached to manipulation means  40   e . If temporary, a used capsule  10   e  may be detached and discarded, and a new capsule  10   e  may then be attached. Also, filtration means of such an embodiment may be permanently attached to capsule  10   e , or temporarily attached to capsule  10   e . If temporary, used filtration means may be detached and discarded, and new filtration means may then be attached. An embodiment of the device generally depicted in  FIG. 9  may be used, for example, as a drinking cup, filtration container, coffee-making device, or tea-making device.  
       FIG. 10  shows a side cut-away view of a similar vessel  50   f  to the one shown in  FIG. 9  ( 50   e ), and another embodiment of assembly  1 . In particular, this embodiment of assembly  1  as shown in  FIG. 10  has different one-way flow means  30   f  (as compared with the previously described embodiments). In this embodiment, one-way flow means  30   f  comprises a wall structure that provides a containment space for fluid. In such an embodiment of assembly  1 , manipulation means  40   f  (same as shown in  FIG. 8 ) move capsule  10   f  up and down to cause, in this case, capsule  10   f  to either collect (when lowered, for example) or filter (when raised, for example) fluid. For example, if capsule  10   f  is lowered down into fluid, fluid would be caused to move around the side of capsule  10   f  and flow into the containment space provided by one-way flow means  30   f  of this embodiment. Once fluid is located in the containment space, manipulation means  40   f  may then be used to raise capsule  10   f  up (close to the lid, for example) to thereby enable fluid to flow through filtration means of this particular embodiment (as a result of gravity, for example). Repeating these steps as needed would pass fluid through filtration means two or more times and cause multiple-pass filtration of the fluid. An embodiment of the device generally depicted in  FIG. 10  may be used, for example, as a drinking cup, filtration container, coffee-making device, or tea-making device.  
       FIGS. 11-13  show representative embodiments of devices that incorporate embodiments of assembly  1  in conjunction with manipulation means that cause a fluid to move through a fixed position capsule.  
       FIG. 11  shows a side cut-away view of yet another device that incorporates an embodiment of assembly  1 . Vessel  50   g  includes capsule  10   g  located in a fixed position relative to vessel  50   g , i.e., attached to vessel  50   g . In this particular embodiment, fluid is caused to be moved through capsule  10   g  that includes both filtration means and one-way flow means.  FIG. 11  shows vessel  50   g  having a lower chamber with deformable portions of its side wall. By depressing the side wall, fluid is caused to be moved up through capsule  10   g . When the side wall of vessel  50   g  is released or otherwise caused to move back to its original position, for example, fluid is drawn back down through capsule  10   g . Repeating such (pumping) action provides a method of using a device of the type shown in  FIG. 11 . Capsule  10   g  of such an embodiment may be permanently attached to the vessel  50   g , or temporarily attached to vessel  50   g . If temporary, used capsule  10   g  may be detached and discarded, and new capsule  10   g  may then be attached. Also, filtration means of such an embodiment may be permanently attached to capsule  10   g , or temporarily attached to capsule  10   g . If temporary, used filtration means may be detached and discarded, and new filtration means may then be attached. An embodiment of the device generally depicted in  FIG. 11  may be used, for example, as a drinking cup, filtration container, coffee-making device, or tea-making device.  
       FIG. 12  shows a side cut-away view of yet another device that incorporates an embodiment of assembly  1 . Vessel  50   h  includes capsule  10   h  located in a fixed position, i.e., integrated into the side wall of the vessel  50   h . In this particular embodiment, fluid is caused to be moved through capsule  10   h  that includes both filtration means and one-way flow means.  FIG. 12  shows vessel  50   g  having a single (or multiple) side chamber(s) with deformable portions of associated side wall. By depressing the side wall, fluid is caused to be moved side-ways through capsule  10   h . When the side wall of vessel  50   h  is released or otherwise caused to move back to its original position, for example, fluid is drawn back through capsule  10   h . Repeating such (pumping) action provides a method of using a device of the type shown in  FIG. 12 . Capsule  10   h  of such an embodiment may be permanently attached to vessel  50   h , or temporarily attached to vessel  50   h . If temporary, used capsule  10   h  may be detached and discarded, and new capsule  10   h  may then be attached. Also, filtration means of such an embodiment may be permanently attached to capsule  10   h , or temporarily attached to capsule  10   h . If temporary, used filtration means may be detached and discarded, and new filtration means may then be attached. An embodiment of the device generally depicted in  FIG. 12  may be used, for example, as a drinking cup, filtration container, coffee-making device, or tea-making device.  
       FIG. 13  shows a side cut-away view of yet another device that incorporates an embodiment of assembly  1 . Vessel  50   i , such as a mug, includes capsule  10   i  in a fixed position, i.e., integrated into the side wall of vessel  50   i . In this particular embodiment, fluid is caused to be moved through capsule  10   i  that has both filtration means and one-way flow means.  FIG. 13  shows vessel  50   i  having a handle that is deformable in some way in order to enable the “pumping” of fluid through filtration means and one-way flow means of capsule  10   i . By depressing the side wall of vessel  50   i , fluid is caused to be moved through capsule  10   i . When the side wall of vessel  50   i  is released or otherwise caused to move back to its original position, for example, fluid is drawn back through capsule  10   i . Repeating such action provides a method of using a device of the type shown in  FIG. 13  to enable multiple-pass filtration. Capsule  10   i  of such an embodiment may be permanently attached to vessel  50   i , or temporarily attached to vessel  50   i . If temporary, a used capsule  10   i  may be detached and discarded, and a new capsule  10   i  may then be attached. Also, filtration means of such an embodiment may be permanently attached to capsule  10   i , or temporarily attached to capsule  10   i . If temporary, used filtration means may be detached and discarded, and new filtration means may then be attached. An embodiment of the device generally depicted in  FIG. 13  may be used, for example, as a drinking cup, filtration container, coffee-making device, or tea-making device.  
     ADDITIONAL EMBODIMENTS  
      Although the description above contains many details, these provide examples of some of the embodiments of the invention, and do not limit the scope of the invention. Furthermore, titles and headings are used solely to aid a reader, and do not limit the scope of the invention.  
      It should be apparent to one skilled in the art that the invention may vary in many aspects, including size, shape, materials, methods of manufacture, and methods of use. In addition, each of the elements of the invention may vary with regard to their number, design, construction, use, combination, and more. Thus the scope of the invention is defined by the attached claims, rather than by the examples given.