Abstract:
A filter assembly for a brew basket includes a filter, a filter holder to removeably hold the filter, one or more support tabs extending outwardly from the periphery of the filter holder to an extent effective in engaging the brew basket so as to suspend the filter holder no higher than substantially flush with an upper rim of the brew basket. The support tabs are of sufficient dimension and under substantially no bending stress when the filter holder is suspended in the brew basket so as to demonstrate no substantial deformation under normal heat conditions within the brew basket during use.

Description:
BACKGROUND OF THE DISCLOSURE  
       [0001]     1. Field of the Disclosure  
         [0002]     The present invention relates to water filters for brew baskets, such as used in coffee makers.  
         [0003]     2. Description of the Related Art  
         [0004]     Various devices have been devised to provide water filters for coffeemakers, many of them complicated and costly. A filter described in Koslow et al., U.S. Patent Publication No. US2001/0032882 A1, entitled DEVICE, METHOD, AND SYSTEM FOR REMOVING CONTAMINANTS FROM A LIQUID, published Oct. 25, 2001, is schematically shown in  FIG. 1 . The device has a filter contained in a circular filter holder  1  that is rimmed with a plurality of flexible thermoplastic supporting tabs  2 . The device is pushed down into a generally conical brew basket  3  until the supporting tabs  2  resiliently bend against the interior surface of the brew basket  3  and thereby support the filter.  
         [0005]     A potential problem with prior plastic framed filters device is that thermoplastics tend to soften and lose their resiliency when subjected to heat and stress, particularly polyethylene. The result is that the filter may drop onto the coffee grounds or even tip over, resulting in a spill-over and allowing unfiltered water to reach the coffee grounds. The present invention has been developed to overcome these drawbacks.  
       BRIEF SUMMARY OF THE DISCLOSURE  
       [0006]     The present invention is directed to a filter assembly for a brew basket having a filter, a filter holder to removeably hold the filter, one or more support tabs extending outwardly from the periphery of the filter holder to an extent effective to engage the brew basket so as to suspend the filter holder no higher than substantially flush with an upper rim of the brew basket. One or more support tabs are of sufficient dimension and under substantially no bending stress when the filter holder is suspended in the brew basket so as to demonstrate no substantial deformation, under normal heat conditions, within the brew basket during use. That is, the support tabs are only subjected to the weight of the filter and filter holder and are not deformed or otherwise loaded during use, other than by the passage of water.  
         [0007]     In another aspect of the invention, the support tabs rest upon an upper rim of the brew basket.  
         [0008]     In another aspect of the invention, each support tab engages a tab receiver located on an inner wall of the brew basket. Each support tab may nest within a tab receiving pocket formed on the brew basket.  
         [0009]     In another aspect of the invention, the filter holder is hinged to the brew basket.  
         [0010]     In another aspect of the invention, the filter is affixed to the filter holder by a plurality of snap-on mounting units, each snap-on mounting unit having a support tab thereon.  
         [0011]     In another aspect of the invention, the filter holder further includes a top retainer and a carrier from which the support tabs extend. The carrier is adapted to receive the top retainer, and the filter is sandwiched and held between the top retainer and the carrier.  
         [0012]     In another aspect of the invention, the filter is affixed to the filter holder with a retaining ring.  
         [0013]     In another aspect of the invention, the filter holder further includes a date indicator.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a schematic drawing, partly in section, of a filter assembly constructed in accordance with the prior art.  
         [0015]      FIGS. 2   a  through  2   c  are perspective views of a first embodiment of the invention.  
         [0016]      FIGS. 3   a  through  3   d  are perspective views of second and third embodiments of the invention.  
         [0017]      FIGS. 4   a  through  4   d  are perspective views of a fourth embodiment of the invention.  
         [0018]      FIG. 5   a  and  5   b  are, respectively, a top plan and a perspective view of a fifth embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     Referring to  FIGS. 2   a ,  2   b  and  2   c  there is shown a preferred embodiment of the invention wherein a filter holder  20  is provided with a plurality of support tabs  21  that extend outwardly there from to engage the inner walls of a brew basket  10 . The support tabs  21  support the filter holder  20  substantially flush with or below the upper rim  10 ′ of the brew basket  10  so as not to interfere with the insertion and removal of the brew basket into and out of a coffee maker. The purpose of the filter holder  20  is to hold and support a water filter. The filter holder  20  is preferably provided with a recess  27  to allow the filter holder to fit within certain brew baskets and to allow the user to easily grasp the filter holder  20  and remove it from the brew basket  10 .  
         [0020]     Referring to  FIGS. 2   b  and  2   c , there is shown a filter holder  20  with a filter  22  mounted thereon. The preferred filter  22  is a disk filter, meaning the thickness of the circular filter  22  is substantially smaller than the width or diameter of the filter. The filter  22  may be adhesively bonded, insert molded, ultrasonically welded or otherwise permanently attached to the filter holder  20 . In this manner, the filter holder  20  and filter  20  may be replaced as a single unit.  
         [0021]     A plurality of snap-on mounting units  23  are provided in the form of resilient Y-shaped fingers, each having a support tab  21  thereon. The snap-on units  23  are snapped on to the filter holder  21  such that a filter retaining portion  24  of the snap-on mounting units  23  engage the filter  22  and hold it in place. The snap-on mounting units are of sufficient thickness and strength so as to avoid loss of resiliency so as to demonstrate no substantial deformation during normal operating temperatures. Further, the support tabs  21  are under sufficiently minimal or no bending when the filter holder  20  is mounted within the brew basket  10  to avoid deformation during normal operating temperatures. The mounting unit  23  fit within the brew basket  10  with a clearance fit, except for tabs  21 .  
         [0022]     For many existing models of coffee makers, there will be sufficient vertical clearance between the upper rim  10 ′ of the brew basket  10  and the coffee maker to allow the support tabs  21  to sit or clamp upon the upper rim  10 ′ of the brew basket. For models with tighter tolerances, it may be necessary to modify the brew basket design to include one or more recessed pockets or tab receivers  28  in the brew basket so as to permit the upper surfaces of the support tabs  21  to sit flush with or below the upper rim  10 ′. The tab receivers  28  may be in the form of notches in the rim  10 ′ of the brew basket  10 , or one or more vertically-recessed ledges on the inside wall of the brew basket  10 , such as the depressed rim  28  shown in  FIGS. 4   a  and  4   b.    
         [0023]     Filter  22  can take the form of a flexible disk having a filtering agent such as activated carbon particles sandwiched between two sheets of flexible porous textile material  30 . An anti-flexing frame structure  25  ( FIG. 2   a ) may be desirable to avoid tearing of the filter material. An annular plastic support ring  31  ( FIG. 2   b ) may be molded around the circumferential edge of the filter  22  to provide additional support and rigidify to the filter  22 .  
         [0024]     Referring to  FIGS. 3   a  through  3   c , there is shown a second embodiment of the invention wherein the filter holder  20  includes a carrier  20   a  and a top retainer  20   b . The carrier  20   a  has an anti-flexing cross brace structure  35  for supporting flexible or rigid filters. The filter  22  maybe bonded or otherwise fixed to the top retainer  20   b  and is thereby held in place on the brew basket  10  by the top retainer  20   b  and the carrier  20   a . One or more support tabs  21  are integrally molded around the carrier&#39;s periphery. The assembly of the carrier  20   a , filter  22  and top retainer  20   b  is simply dropped into the brew basket  10  with a circumferential clearance fit (except for tabs  21 ) for easy mounting.  
         [0025]     What is meant by “one or more” support tabs  21  is that a single support tab may support the filter if the single “tab” is formed as an annular ring or rim encircling the rim of the carrier. The single tab may extend more than 180 degrees around the rim of the carrier  20   a.    
         [0026]     Referring to  FIG. 3   d  there is shown a third embodiment where the carrier  20   a  is hinged to the brew basket  10  about a horizontal axis and may simply be swung out of the way when emptying the brew basket  10  of used coffee grounds. The carrier  20   a  may be removably and replaceably snap fit to the brew basket  10  with a pair of resilient ball and socket hinges  36  of the type commonly used on hinged plastic boxes and the like. A piano type hinge may also be used.  
         [0027]     As shown in  FIGS. 4   a  through  4   d , fourth and fifth embodiments of the invention mold the support tabs  21  integrally and homogeneously onto the filter holder  20 . For purposes of clarity, neither the filter nor the means of securing it to the filter holder are shown.  
         [0028]     In  FIGS. 4   a  and  4   b , the support tabs  21  are mounted high on the rim of the filter holder  20  and engage the brew basket  10  as described above with respect to the previous embodiments of  FIGS. 2 and 3 . Here the tab receiver  28  is shown as a depressed rim or stepped recessed ledge running around the inside wall of the brew basket  10 .  
         [0029]     In  FIGS. 4   c  and  4   d , the support tabs  21  are mounted lower on the rim of the filter holder and engage the upper rim of a filter basket  40  typically including a permanent metal or plastic filter screen. Such filter baskets  40  may have a bail or swing handle  41 , so in such cases the diameter of the filter holder  20  will be chosen to fit within the diameter or opening defined by the swing handle  41 .  
         [0030]     Referring to  FIGS. 5   a  and  5   b , there is shown a sixth embodiment of the invention wherein support tabs  21  are preferably integrally and homogeneously molded onto the filter holder  20 . The filter  22  is held onto the filter holder  20  by a retaining ring  50  which attaches to the bottom of the filter holder  20 , such as by screwing onto the bottom of the filter holder  20  or any other suitable interlocking means. The filter  22  is thereby sandwiched and clamped between the filter holder  20  and the retaining ring  50 . The retaining ring  50  may be provided with a lower support structure such as cross braces  35  to retard flexing of the filter  22 . This is also a means of retaining the filter for use with the embodiments of  FIG. 4 .  
         [0031]     The filter holder may be provided with a date indicator  51 , including a slide indicator  52 , a notched slide groove  53 , and date graduations  54  opposite the notches  55 . The date graduations  54  will preferably indicate the twelve months of the year. When the user replaces the filter  21 , the user slides the slide  52  to the proper notch to indicate either the current month or the month the filter  21  should be replaced. In this manner, the user is reminded when to change the filter  21 . The slide indicator  52  is adapted to resiliently snap into and out of the notches  55 .  
         [0032]     One preferred material for making the filter holder  20 , clip-on units  23 , carrier  20   a , and retaining ring is thermoplastic. Homopolymers are inexpensive and readily available thermoplastics, such as polyethylene and polypropylene. Polypropylene is preferred over polyethylene because of its greater resistance to deformation under conditions of heat and stress.  
         [0033]     The preferred filter is a filtering agent, such as activated carbon, sandwiched between two porous sheets of material  30 . A preferred disk filter  22  is thin, perhaps no more than a sixteenth to an eighth of an inch.  
         [0034]     While various values, scalar and otherwise, may be disclosed herein, it is to be understood that these are not exact values, but rather to be interpreted as “about” such values, unless explicitly stated otherwise. Further, the use of a modifier such as “about” or “approximately” in this specification with respect to any value is not to imply that the absence of such a modifier with respect to another value indicated the latter to be exact.  
         [0035]     Changes and modifications can be made by those skilled in the art to the embodiments as disclosed herein and such examples, illustrations, and theories are for explanatory purposes and are not intended to limit the scope of the claims. Further, the abstract of this disclosure is provided for the sole purpose of complying with the rules requiring an abstract so as to allow a searcher or other reader to quickly ascertain the subject matter of the disclosures contained herein and is submitted with the express understanding that it will. not be used to interpret or to limit the scope or the meaning of the claims.