Patent Publication Number: US-11045751-B2

Title: Filter design with interchangeable core cover

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/756,768 filed on Mar. 1, 2018, now U.S. Pat. No. 10,391,427, which claims the benefit and priority of International Application No. PCT/IB2016/001479, filed on Sep. 27, 2016, which claims the benefit of U.S. Provisional Application No. 62/235,304, filed on Sep. 30, 2015. This application is also related to the following United States patent applications: (1.) U.S. application Ser. No. 15/756,713 filed on Mar. 1, 2018, which claims the benefit and priority of International Application No. PCT/IB2016/001472, filed on Sep. 27, 2016, which claims the benefit of U.S. Provisional Application No. 62/235,289, filed on Sep. 30, 2015; (2.) U.S. application Ser. No. 15/756,747 filed on Mar. 1, 2018, now U.S. Pat. No. 10,765,973, which claims the benefit and priority of International Application No. PCT/IB2016/001495, filed on Sep. 27, 2016, which claims the benefit of U.S. Provisional Application No. 62/235,295, filed on Sep. 30, 2015; and (3.) U.S. application Ser. No. 15/756,809 filed on Mar. 1, 2018, now U.S. Pat. No. 10,343,931, which claims the benefit and priority of International Application No. PCT/IB2016/001474 filed on Sep. 27, 2016, which claims the benefit of U.S. Provisional Application No. 62/235,321 filed on Sep. 30, 2015. The entire disclosures of each of the above applications are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments of the present invention generally concern water filtration systems for pitchers and other fluid containers. More particularly, embodiments of the invention relate to an interchangeable core cover configured to be used with a filter core of a filter assembly. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Water filtration has become common in homes, offices and other places to produce cleaner and better tasting water. Accordingly, water containers such as pitchers have been equipped with filtration systems. In some instances, these filtration systems may employ a filter core around which a piece of a filter medium is wrapped and secured. The filter core can include various openings that allow unfiltered water to enter the interior of the filter core by passing through the filter medium. The filtered water can then exit through an open end of the filter core. 
     Although filter assemblies such as that just described have proven useful in some circumstances, certain problems nonetheless remain. For example, the filter core is typically configured with an outlet of fixed diameter that is sized for a particular flow rate, or range of flow rates, based upon the filter medium, or filter media, employed in the associated filter assembly. This can be problematic from a variety of perspectives. 
     For example, a manufacturer would be required to produce an array of different filter cores, each having a particular outlet diameter matched to the particular filter medium, or media, expected to be used with that filter core. This is an inefficient approach to manufacturing inasmuch as it would require tool and/or process changes to manufacture filter cores having different outlet sizes. 
     A related concern is that careful attention must be paid during the manufacturing process to ensure that a filter core of the appropriate outlet diameter is correctly matched to the filter medium or filter media that is to be used with that filter core. For example, a filter core with relatively small outlet diameter, and a correspondingly low flow rate, may not provide a satisfactory consumer experience. As another example, a filter core with relatively large outlet diameter, and a correspondingly high flow rate, may not enable adequate contact time between the fluid and the filtration medium/media, thus limiting the effectiveness of the filter assembly. 
     Further, a filter core configuration with a fixed diameter can be problematic for the consumer as well. For example, even if the consumer is willing to exchange a degree of filtration effectiveness for a relatively higher flow rate, the fixed diameter of the filter core may prevent such a tradeoff, resulting in dissatisfaction on the part of the consumer. Likewise, even if the consumer is willing to accept a reduced flow rate in exchange for a relative improvement in filtration performance, the fixed diameter of the filter core may prevent such a tradeoff, again resulting in dissatisfaction on the part of the consumer. 
     In light of problems such as those noted above, it would be useful to provide a filter core that is not limited to a fixed flow rate, or range of flow rates. As well, it would useful to provide a filter core having a flow rate, or range of flow rates, that corresponds to the type of filter medium/media with which the filter core is employed. Finally, it would be useful to provide a filter core that can be readily configured to provide any one of a number of desired flow rates. 
     SUMMARY 
     One or more embodiments within the scope of the invention may be effective in overcoming one or more of the disadvantages in the art. One example embodiment is directed to a core cover configured to pass a particular flow rate or range of flow rates when employed in a filter assembly. As such, the core cover implements a flow regulation function, among others. 
     Core covers according to embodiments of the invention can each be configured to pass a particular flow rate or range of flow rates. Notwithstanding any differences in the respective flow rates they are configured to pass however, each of the core covers has a common interface configuration that enables them to be used interchangeably in the same filter core, or filter cores of the same configuration. Thus, the flow rate associated with a particular filter core can be easily customized, such as during manufacturing for example, by simply selecting a core cover with the desired flow rate. The core cover can be simple in construction and may, in some cases, take the form of a unitary, single-piece structure. 
     In at least some embodiments, the core cover remains permanently engaged with the filter core once installed in the filter core. In other embodiments, the core cover is releasably engageable with the filter core such that an existing core cover in a filter core can be removed and replaced with another filter core. 
     The core cover can include indicia that are perceptible by the senses of a user. The indicia may directly indicate or reference, for example, any one or more of the flow rate or range of flow rates the core cover is configured to pass, and/or the type(s) of filter medium/media for which the core cover is suited. As well, the indicia can take any form perceptible by one or more senses of a user, examples of which include colors, numbers, letters, shapes, and symbols. Thus, some indicia, such as raised letters or numbers for example, can be both seen and felt by a user, while other indicia, such as color for example, are only visually perceptible. In any case, the scope of the invention is not limited to the use of any particular indicator or indicia however. 
     Finally, some embodiments of the core cover can be used in connection with a filter assembly including a filter core about which a filter medium is wrapped two or more times. In one particular embodiment, the filter medium is a laminate that includes a layer of activated carbon fiber (ACF) media positioned between two layers of non-woven material. Still other embodiments of the core cover are used in connection with a filter assembly including a filter core or filter cartridge that contains a filter medium such as ion exchange resin (IER) which may be combined in some cases with activated carbon granules. 
     The foregoing examples are provided solely by way of example and is not intended to limit the scope of the invention in any way. Consistently, various other embodiments of filter assemblies, and associated filter media and core covers, within the scope of the invention are disclosed herein. 
    
    
     
       DRAWINGS 
       In order to describe the manner in which at least some aspects of this disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only example embodiments of the invention and are not therefore to be considered to be limiting of its scope, embodiments of the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG. 1  is a top perspective view of an example embodiment of a filter assembly and associated cage; 
         FIG. 2  is an exploded view of the example filter assembly of  FIG. 1 ; 
         FIG. 3  is a top perspective view of an example embodiment of a filter assembly and associated core cover; 
         FIG. 4  is a top perspective view of an example filter core including a core cover; 
         FIGS. 5 a  and 5 b    are section views of an example filter core and core cover; 
         FIG. 6  is an exploded view of an example filter core and core cover; 
         FIG. 7  is a bottom perspective view of an example core cover; and 
         FIG. 8  is a top perspective view of an example core cover. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to aspects of various embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. While described in conjunction with these embodiments, it will be understood that they are not intended to limit the disclosure to these embodiments. 
     In general, embodiments of the invention can be employed in connection with devices, such as filter assemblies and fluid containers, where there is a need to filter fluid as, and/or before, the fluid is dispensed from the container. In one particular example, embodiments of the invention can be used in conjunction with a pitcher, although the scope of the invention is not limited to this example environment and extends, more generally, to any environment where such embodiments can be usefully employed. For example, embodiments of the invention can be employed with any water, or other fluid, container, examples of which include, but are not limited to, bottles, carafes, and jugs. 
     A. Example Filter Assembly 
     Directing attention now to  FIGS. 1 and 2 , details are provided concerning a filter assembly, one example of which is denoted generally at  100 . Embodiments of the filter assembly  100  can be employed in connection with a cage  50  that may be a removable element of a fluid container, such as the example fluid containers disclosed herein. In general, the filter assembly  100  can be releasably engaged with the cage  50 , and the cage  50  then connected to the fluid container. In the particular example of  FIGS. 1 and 2 , the filter assembly  100  can be configured to releasably engage the cage  50  in a push fit or snap fit arrangement. As such, the filter assembly  100  can include structures (not shown) that can be releasably engaged with corresponding structure(s) (not shown) of the cage  50  by pushing the filter assembly  100  into the cage  50  until the filter assembly  100  snaps or locks into the cage  50 . Likewise, the filter assembly  100  can be removed from the cage  50  by pushing the filter assembly  100  at a location near the bottom of the cage  50 . The scope of the invention is not limited to the foregoing example however, and any other structure(s) that enable releasable engagement of the cage  50  and the filter assembly  100  with each other can be used. 
     As best shown in  FIG. 2 , the example filter assembly  100  includes a filter core  200  that may include one or more sealing elements  250 , such as an O-ring for example, that seals the filter core  200  to the fluid container (not shown) when the filter core  200  and fluid container are engaged with each other, so as to prevent bypass of unfiltered fluid past the filter core  200  and out of the fluid container. In the example of  FIG. 3 , the filter assembly  100  further includes a filter medium  300  attached to the filter core  200 . In particular, the filter medium  300  can be wrapped around the filter core  200  to form multiple stacked layers, as shown in  FIGS. 2, 3, and 5  discussed below. Some examples of a filter medium  300  that can be used in connection with embodiments of the filter core  200  are disclosed in United States Publication No. 2018-0311600, and identified in the ‘Related Applications’ section of this disclosure. The scope of the invention is not limited to the use of such a filter medium however. 
     With continued reference to  FIGS. 1 and 3 , the filter assembly  100  further includes a core cover  400 . In general, the core cover  400  can define a flow control opening  402  that enables control of the flow rate of fluid out of the filter assembly  100 . The core cover  400  can be removably attached to the filter core  200  in any suitable way, such as with threads, a snap-fit arrangement, or any other type of respective complementary structures. Some example complementary structures of a filter core and core cover are disclosed in the aforementioned ‘Related Application.’ 
     With particular attention now to  FIGS. 3 and 4 , and continuing attention to  FIG. 2 , the example filter assembly  100  is disclosed with the cage  50  omitted.  FIGS. 2 and 3  indicate that the filter medium  300  is wrapped multiple times around the filter core  200 . Thus, in order to enter the filter core  200 , such as during a fluid dispensing process for example, the fluid to be filtered must pass through the layers of the filter medium  300 . In more detail, and with reference to  FIGS. 3 and 4 , fluid passing through the filter medium  300  from a location external to the filter assembly  100  enters the hollow interior  202  and can then exit the filter core  200  by way of the core cover  400 . 
     B. Example Core Cover 
     With continued attention to  FIG. 4 , and directing attention now to  FIGS. 5 a   - 8 , details are provided concerning example embodiments of a core cover, one example of which is denoted at  400 . In general, the core cover  400  can be made of any suitable material, or materials. Example embodiments of the core cover  400  are made of chemically inert materials. In at least some embodiments, the core cover  400  is substantially, or completely, made of plastic. Moreover, the core cover  400  may have a unitary, single-piece construction. As well, the core cover  400  can be constructed using any suitable production process(es), one example of which is injection molding. 
     As shown in  FIG. 4 , the core cover  400  can be configured such that when the core cover  400  is fully received by the filter core  200 , the upper surface  402  of the core cover  400  is substantially flush with the end surface  204  of the filter core  200 . In the illustrated example, the core cover  400  and corresponding receiving structure of the filter core  200  are indicated as generally circular in shape. However, other shapes can be employed and the scope of the invention is not limited to the illustrated example. 
     With continued reference to  FIG. 4 , the core cover  400  defines a fluid passageway  404  that is arranged for fluid communication with the interior  202  of the filter core  200  when the core cover  400  is positioned as indicated. Further details concerning the fluid passageway  404  can be found in the discussion of the remaining figures below. 
     Directing attention now to  FIGS. 5 a  and 5 b   , details are provided concerning some aspects of an example interface between the core cover  400  and the filter core  200 . In the illustrated example, the filter core  200  defines a recess  206  sized and configured to receive the core cover  400 . In general, the recess  206  is axially aligned with the fluid passageway  404  of the core cover  400  when the core cover  400  is received in the recess  206 , and the recess  206  is in fluid communication with the interior  202  of the filter core  200 . The depth of the recess  206 , which can generally correspond to the overall height of the core cover  400 , is defined by an annular shoulder  208 . Among other things, the annular shoulder  208  can serve to limit the depth to which the core cover  400  is inserted into the recess  206 . Any other structure(s) of comparable functionality could alternatively be employed however. 
     As further indicated in  FIG. 5 a    in particular, the filter core  200  can include one or more complementary structures  210  configured to engage, either permanently or releasably, one or more corresponding complementary structures  406  of the core cover  400 . In the particular embodiment illustrated in  FIG. 5 a   , the complementary structures  210  comprise a plurality of elongate protrusions disposed about a perimeter of the recess  206 . The example of  FIG. 5 b    includes four protrusions, but any suitable number of protrusions, such as one, two, three or any number more than four, could be employed. In general, the protrusions extend radially into the recess  206  so as to be positioned to engage the complementary structures  406  of the core cover  400  as the core cover  400  is moved into position in the recess  206 . 
     In particular, the complementary structure  406  can take the form of an annular ring disposed about the exterior of the core cover  400  and extending outwardly in a radial direction from the core cover  400  side surface  408 . When in the form of an annular ring at least, the complementary structure  406  is configured and arranged to slip past the complementary structure(s)  210 , which may be in the form of protrusions as discussed above, as the core cover  400  is inserted into the recess  206 . 
     In their undeformed dispositions, the complementary structures  210  and  406  may collectively form an interference fit. For example, the outside diameter of the complementary structure  406 , when in the form of an annular ring for example, may be relatively larger than the inside diameter of the complementary structure  210 , when in the form of protrusions for example. As such, the core cover  400  cannot be fully inserted into the recess  206  unless the core cover  400  is deformed to some degree. Accordingly, at least some embodiments of the core cover  400  are configured to elastically deform to the extent necessary to enable full insertion of the core cover  400  into the recess  206 . 
     In at least some embodiments, this functionality is achieved by way of a cantilever configuration defined by the inner wall  410  and outer wall  412  of the core cover  400 . In particular, because the bottom end of the outer wall  412  is unconstrained, it is movable to some extent in a radial direction. Correspondingly, the radial position of the complementary structure  406 , which is positioned on the outer wall  412 , can be changed, such as when the core cover  400  is inserted into the recess  206 . Thus, an insertion force F (see  FIG. 5 a   ) exerted on the core cover  400  temporarily overcomes the interference between the complementary structures  406  and  210  by causing an elastic deformation of the outer wall  412  as the complementary structure  406  encounters the complementary structure  210  of the filter core  200 . After the complementary structure  406  is positioned below the complementary structure  210 , the outer wall  412  reassumes its undeformed state where the free end of the outer wall  412  is undeflected, thus locking the core cover  400  into the recess  206 , as shown in  FIG. 5   b.    
     If there is a need to ensure that the core cover  400  remains permanently in the recess  206 , one or both of the complementary structures  210  and  406  can be modified to increase the extent to which those structures interfere with each other. On the other hand, if there is a need to be able to remove the core cover  400  from the recess  206 , the interference fit between the complementary structures  210  and  406  can be implemented accordingly. 
     While the example of  FIGS. 5 a  and 5 b    utilizes an interference fit to ensure retention, either permanent or removable, of the core cover  400  in the filter core  200 , various other complementary structures can be employed to engage the core cover  400  and filter core  200 , whether permanently or releasably. As an example of the latter, the core cover outer wall  412  can include threads (not shown) that engage corresponding threads (not shown) of the wall  212  that defines the recess  206 . Thus, a core cover  400  configured in this way can be easily installed, removed, and replaced in a filter core  200 . 
     It will be appreciated from the foregoing discussion that the complementary structures disclosed herein are but a few examples of structural implementations of a means for engaging, permanently or releasably depending on the embodiment, the core cover  400  and the filter core  200 . Accordingly, any other structure(s) of comparable functionality could alternatively be employed. 
     With reference now to  FIGS. 6-8 , additional details are provided concerning the structure and operation of example embodiments of the core cover  400 . As shown, embodiments of the core cover  400  may include additional structures that engage corresponding structures of the filter core  200 . For example, the core cover  400  may include one or more index slots  414  that releasably engage a corresponding index guide  214 , or index guides  214  as applicable, of the filter core  200 . In the illustrated example, the index guide  214  takes the form of an axially oriented protrusion extending from the wall  212  of the filter core  200 . The index slot  414  and index guide  214  can be used to orient the core cover  400  in a particular way relative to the filter core  200  by inserting the core cover  400  in the filter core  200  so that the index guide  214  is received in the index slot  414 . The index guide  214  and index slot  414  can also cooperate with each other to prevent axial rotation of the core cover  400  in the recess  206 . 
     C. Flow Control 
     With continued reference to  FIGS. 7 and 8  in particular, the fluid passageway  404  of the core cover  400  is an example structural implementation of a means for flow control. Any other structure(s) of comparable functionality can alternatively be employed however. In general, the diameter D of the fluid passageway  404  can be selected as desired to enable a particular flow rate, or range of flow rates, through the fluid passageway  404 . This notion is embodied in the equation: Q=V×A, where Q is the desired flow rate, V is the velocity of the flow, and A is the area of the fluid passageway  404 . The area A is a function of the diameter D, thus: A=π×D 2 /4. In embodiments where the fluid passageway  404  is non-circular, the area A can be readily obtained by other suitable equations, and then selected as necessary to obtain a desired flow rate or range of flow rates. 
     While the example fluid passageway  404  is indicated in the figures as being generally cylindrical in shape, and thus having a relatively constant diameter, the scope of the invention is not so limited. Thus, for example, the fluid passageway  404  can have a conical type of configuration in which the diameter increases, or decreases, from the first end of the fluid passageway  404  to the second end of the fluid passageway  404 . 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.