Patent Application
20050236323
1. Field of the Disclosure
The present invention relates to water filters for brew baskets, such as used in coffee makers.
2. Description of the Related Art
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
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.
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.
In another aspect of the invention, the support tabs rest upon an upper rim of the brew basket.
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.
In another aspect of the invention, the filter holder is hinged to the brew basket.
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.
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.
In another aspect of the invention, the filter is affixed to the filter holder with a retaining ring.
In another aspect of the invention, the filter holder further includes a date indicator.
a through 2c are perspective views of a first embodiment of the invention.
a through 3d are perspective views of second and third embodiments of the invention.
a through 4d are perspective views of a fourth embodiment of the invention.
a and 5b are, respectively, a top plan and a perspective view of a fifth embodiment of the invention.
Referring to
Referring to
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.
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
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 (
Referring to
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 20a.
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As shown in
In
In
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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.
One preferred material for making the filter holder 20, clip-on units 23, carrier 20a, 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.
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.
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.
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.
