Abstract:
A system and method for reducing the amount of caffeine in an existing volume of brewed coffee. The brewed coffee contains a predetermined level of caffeine. To reduce the caffeine, a caffeine filter is provided. Furthermore, a coffee receptacle is provided to hold the decaffeinated coffee. A filter chamber is positioned over the coffee receptacle. The caffeine filter is placed in the filter chamber. Brewed coffee is dripped, poured, or otherwise advanced into the filter chamber. At least some of the brewed coffee flows through the caffeine filter and into the coffee receptacle. This reduces the level of caffeine of the filtered coffee entering the coffee receptacle. The system also enables a single source of brewed coffee to produce cups of both regular coffee and decaffeinated coffee, using only one type of regular ground coffee.

Description:
REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 15/288,143, filed Oct. 7, 2016, which is a continuation of U.S. patent application Ser. No. 13/099,456, filed May 3, 2011, the entire content of each application being incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    In general, the present invention relates to coffee makers that are used to brew either a cup or a pot of coffee. Additionally, the present invention relates to systems and methods that are used to remove caffeine from brewed coffee. 
       BACKGROUND OF THE INVENTION 
       [0003]    Many people like to drink freshly brewed coffee. Of those people, some like to drink regular caffeinated coffee, while others prefer to drink decaffeinated coffee. As a consequence, when a group of people are gathered, separate pots of regular coffee and decaffeinated coffee need to be brewed in order to accommodate the different preferences of coffee drinkers. 
         [0004]    In many homes, people brew coffee using a coffeemaker. Some of the most popular coffee makers are drip coffee makers. In a drip coffee maker, ground coffee is placed in a filter cone above a pot. The coffee maker heats water and then directs the heated water through the filter cone. The water brews the coffee and the coffee drips through the filter and into the awaiting pot. Many people only have a single coffee maker. Consequently, if a person wants to serve both regular coffee and decaffeinated coffee, two separate pots of coffee must be brewed. Furthermore, once one type of coffee is brewed, the coffee must be transferred to some secondary serving pot, so that the coffee machine pot is available for use in making the second type of coffee. 
         [0005]    In the prior art, attempts have been made to solve this problem by creating caffeine filtering packets that are placed into a coffee cup. As regular coffee is poured into a coffee cup, the caffeine in the coffee is partially removed by the filter packet. Such prior art systems are exemplified by U.S. Pat. No. 5,603,830 to Everhart, entitled Caffeine Adsorbent Liquid Filter With Integrated Adsorbent. The problem with such prior art filter packets is one of effectiveness. Coffee is brewed at the temperature of boiling water. As soon as the coffee is brewed, it begins to cool. The coffee starts to cool as soon as it drips into the coffee pot. The coffee further cools as it is poured through the air and into a cold coffee cup. Furthermore, the coffee cools even more as it saturates the cold filter packet. As the coffee cools it loses significant energy. As a result, the cooled coffee in cup must sit with a filter packet for up to two minutes, to remove a mere 40 percent of the caffeine in the coffee. 
         [0006]    Many people do not want to wait to drink their coffee. Furthermore, many people do not consider coffee that still has sixty-percent of its caffeine to be decaffeinated. 
         [0007]    In the prior art, attempts have been made to remove caffeine from coffee when it is at its hottest temperature. This is typically done by creating a coffee filter that also is a caffeine filter. Such a prior art system is exemplified by U.S. Pat. No. 2,375,550 to Grossman, entitled Removal of Caffeine From Coffee Extract. 
         [0008]    The problem with such filters is one of flow rate. Drip coffee makers need thin porous coffee filters in order to achieve the proper flow rate of coffee through the filter. If the filter is too thick, or otherwise too dense, the coffee will back up in the filter and overflow out of the coffee maker. When a caffeine filter is added to the coffee filter, it must be made very thin in order to maintain the required coffee flow through rate. However, making a caffeine filter so thin, severely limits its effectiveness. As a consequence, still less than half of the caffeine in the coffee is removed. 
         [0009]    Another problem associated with combining a caffeine filter with a coffee filter is that the caffeine filter affects all of the coffee that passes through the filter. Consequently, a person can create a pot of partially decaffeinated coffee, but they still have to brew a pot of regular coffee if both regular and decaffeinated coffee are to be served. Furthermore, since the entire pot of coffee is decaffeinated by the filter, it is more efficient just to simply use decaffeinated coffee to start. A need therefore exists for a coffee maker that brews caffeinated coffee and yet can remove at least 50% and up to 90% percent of the caffeine from the brewed coffee before it is served. A need also exists for a coffee maker that can make a single brew of coffee and produce individual servings of either regular coffee or decaffeinated coffee from that single brew. These needs are met by the present invention as described and claimed below. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention is a system and method for reducing the amount of caffeine in an existing volume of brewed coffee. The brewed coffee, by nature, contains a predetermined level of caffeine. To reduce this level of caffeine, a caffeine filter is provided. Furthermore, a coffee receptacle, such as a coffee cup or a coffee pot is provided to hold the decaffeinated coffee. 
         [0011]    A filter chamber is positioned over the coffee receptacle. The caffeine filter is placed in the filter chamber. Brewed coffee is dripped, poured, or otherwise advanced into the filter chamber. At least some of the brewed coffee is directed through the caffeine filter and into the coffee receptacle. This reduces the level of caffeine of the filtered coffee filling the coffee receptacle. The system also enables a single source of brewed coffee to produce cups of both regular coffee and decaffeinated coffee, using only one type of regular ground coffee. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For a better understanding of the present invention, reference is made to the following description of exemplary embodiments thereof, considered in conjunction with the accompanying drawings, in which: 
           [0013]      FIG. 1  is a perspective view of an exemplary embodiment of a coffee maker machine; 
           [0014]      FIG. 2  is a schematic of the operational features of the coffee maker machine shown in  FIG. 1 ; 
           [0015]      FIG. 3  is a schematic of an alternate embodiment of a coffee maker machine; 
           [0016]      FIG. 4  is a perspective view of an alternate embodiment of the present invention; 
           [0017]      FIG. 5  is a perspective view of an alternate embodiment of the present invention; 
           [0018]      FIG. 6  is a high-performance liquid chromatography (HPLC) curve for standard caffeine; 
           [0019]      FIG. 7  is a high-performance liquid chromatography (HPLC) curve for regular coffee; 
           [0020]      FIG. 8  is a high-performance liquid chromatography (HPLC) curve for Calgon Type TOG-NDG-LF-5 in fine powder form; 
           [0021]      FIG. 9  is a high-performance liquid chromatography (HPLC) curve for Norit GA830 in granular form; 
           [0022]      FIG. 10  is a high-performance liquid chromatography (HPLC) curve for Norit GAC1240 in granular form; and 
           [0023]      FIG. 11  is a high-performance liquid chromatography (HPLC) curve for Norit PAC200 in fine powder form. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    Although the present invention assembly and method can be embodied in many ways, the embodiments illustrated show the assembly configured as a drip coffee maker for in-home use. These embodiments are selected in order to set forth the best modes contemplated for the invention. The illustrated embodiments, however, are merely exemplary and should not be considered limitations when interpreting the scope of the appended claims. 
         [0025]    Referring to both  FIGS. 1 and 2 , a drip coffee maker  10  is shown. The coffee maker  10  has a receptacle port  12  sized to receive a coffee pot  14 . Within the receptacle port  12 , a heater  15  is provided to heat the contents of the coffee pot  14 . 
         [0026]    A brew chamber  16  is positioned at the top of the coffee maker  10  above the receptacle port  12  and the coffee pot  14 . A traditional prior art coffee filter  18  is placed in the brew chamber  16 . The coffee filter  18  is partially filled with regular caffeinated ground coffee  20 . The ground coffee  20  contains caffeine, as is the case with natural coffee. A water reservoir  22 , water heater  24  and water pump  26  are provided. The water heater  24  heats some of the water from the water reservoir  22  to a temperature just below boiling. The heated water is pumped into the brew chamber  16 , wherein the water brews the ground coffee  20  to produce brewed coffee  30 . The brewed coffee  30  permeates through the coffee filter  18 . The water pump  26  and the water heater  24  are managed by a control circuit  28 . The control circuit  28  is set by a user interacting with the various manual controls  32 , in the form of buttons and knobs manufactured into the coffee maker  10 . In this manner, the coffee maker  10  can be set to brew one cup, two cups or any number of cups up to the capacity of the coffee pot  14 . 
         [0027]    If regular coffee is desired, the brewed coffee  30  passing through the coffee filter  18  is permitted to drip directly into the coffee pot  14 . The coffee pot  14  will therefore fill with regular caffeinated coffee. However, if decaffeinated coffee is desired, an auxiliary filter system is provided. 
         [0028]    A filter chamber  34  is provided below the brew chamber  16  and above the coffee pot  14 . The filter chamber  34  has a large open top  35  that receives the brewed coffee  30  dripping out of the brew chamber  16 . The brewed chamber  16  has side walls  36  that funnel the brewed coffee  30  to a narrow flow opening  38  at the bottom of the filter chamber  34 . Accordingly, any brewed coffee  30  that drips into the open top  35  of the filter chamber  34  is funneled to the flow opening  38  at the bottom of the filter chamber  34 . 
         [0029]    A filter support structure  40  is formed within the filter chamber  34 . The filter support structure  40  is configured to receive and retain a removable caffeine filter  42 . When the caffeine filter  42  is placed in the filter support structure  40 , all the brewed coffee  30  that flows through the filter chamber  34  is directed through the caffeine filter  42 . The caffeine filter  42  is a premanufactured packet that contains activated charcoal and/or other material that interacts with the caffeine present within the brewed coffee  30  or adsorbs the caffeine. 
         [0030]    The shape of the filter  42  may be varied in accordance with the shape of the filter holder and/or the desired amount of time that the caffeinated coffee is exposed to the activated charcoal or adsorbant. Thus, the filter may be pad-shaped with a single peripheral seam or puck-shaped with one or more peripheral seams. The thickness of the filter may be in the range of 0.25 to 2 inches, again, depending upon the shape of the filter holder and/or the desired amount of time that the caffeinated coffee is exposed to the activated charcoal or adsorbant. The peripheral shape of the filter may be round, oval, square or any operative shape. The activated charcoal or adsorbant may be embedded into a funnel shape with an inner filter, an outer filter, and the charcoal or adsorbant disposed therebetween. The filter “paper” may be natural or synthetic, with the porosity of the material being selected as a function of grain size. That is, for a granular material, the porosity may be greater than a material used in conjunction with a fine powder to minimize the amount of activated charcoal or adsorbant escaping from the filter as the caffeinated coffee flows therethrough. 
         [0031]    The amount of activated charcoal or adsorbant in the filter is also a function of the amount of caffeinated coffee to be decaffeinated and the desired level of decaffeination. In preferred embodiments, the caffeine filter  42  contains an amount of activated charcoal  44  in the range of 1 to 10 grams. In more preferred embodiments, the caffeine filter  42  contains at least five grams. Much larger amounts of activated charcoal  44 , in the range of 10 to 100 grams can be used to decaffeinate large pots of coffee. Although the primary function of the caffeine filter  42  is to remove caffeine from the brewed coffee  30 , the caffeine filter  42  may contain other ingredients that add material to the brewed coffee  30 . For example, flavorants may be provided in the caffeine filter  42  that add flavors, such as vanilla or cinnamon to the brewed coffee  30 . 
         [0032]    The rate of flow out of the brew chamber  16  is known by the manufacturer of the coffee maker  10 . For many traditional coffee makers, this flow rate is between 0.05 and 0.5 fluid ounces per second. The size of the filter chamber  34  and the porosity of the caffeine filter  42  are designed so that the flow rate through the filter chamber  34  and the caffeine filter  42  is greater than the flow rate out of the brew chamber  16 . In this manner, when the coffee maker  10  is in operation, the flow out of the brew chamber  16  cannot cause the underlying filter chamber  34  to overflow. 
         [0033]    The caffeine filter  42  is selectively inserted into, and removed from, the filter chamber  34 . When the caffeine filter  42  is not in place, the brewed coffee  30  flows through the empty filter chamber  34  and filter support structure  40  without being altered. However, when the caffeine filter  42  is in place, all the brewed coffee  30  flowing into the coffee pot  14  passes through the caffeine filter  42 . The filter support structure  40  has a swivel arm  46  that is pivotably connected to the coffee maker  10 . As a result, the filter support structure  40  can be selectively moved between an operational position and a loading position. When the filter support structure  40  is in its loading position, it is pivoted out of the filter chamber  34  so that the caffeine filter  42  is accessible and easy to both load and unload. When the pivoting retainer is moved to its operational position, the filter support structure  40  holds the caffeine filter  42  in position within the filter chamber  34 . 
         [0034]    It will be understood that the brewed coffee  30  is at its hottest in the coffee maker  10  while the brewed coffee  30  is first made in the brew chamber  16 . By positioning the caffeine filter  42  directly under the brew chamber  16 , the caffeine filter  42  receives the brewed coffee  30  before the brewed coffee  30  has had the ability to cool to any significant degree. As a result, the brewed coffee  30  interacts with the caffeine filter  42  while at or near its brewing temperature and reaches the coffee pot with minimum loss of temperature. Furthermore, since the brewed coffee  30  is dripping through the caffeine filter  42  at a rate controlled by gravity, the caffeine filter  42  never becomes overwhelmed by the volume of brewed coffee  30 . The result is that all of the brewed coffee  30  passes through the caffeine filter  42 . None of the brewed coffee  30  flows around the caffeine filter  42  without being affected. As a consequence, over ninety percent of the caffeine contained within the brewed coffee  30  can be removed by the caffeine filter  42 . 
         [0035]    To determine the effectiveness of commercially available caffeine adsorbants, experiments were conducted using high-performance liquid chromatography (HPLC).  FIGS. 6 through 11  show, respectively, HPLC curves for standard caffeine; regular coffee; Calgon Type TOG-NDG-LF-5 in fine powder form; Norit GA830 in granular form; Norit GAC1240 in granular form; and Norit PAC200 in fine powder form. This study shows while that granular activated carbon may not be that effective, activated carbon in fine powder form of highly effective in removing caffeine from regular coffee in a short period of time. 
         [0036]    The experimental procedures were as follows:
       1) Blank: brew 4 cups (˜636 mL) of water through coffee maker with white filter paper.   2) Brew (˜2×7.4 g) of coffee using 4 cups of water (˜636 mL), with white filter paper.   3) A small amount of brewed coffee was injected into HPLC to determine its initial caffeine content.   4) Pour 150 mL hot coffee (50° C.) over 5 g activated carbon in one-layer white Whatman #40 filter paper (150 mm, Catalog #1440-150) in a funnel Filter paper.   5) About 1 mL of the filtrate was further centrifuged to precipitate the activated carbon.   6) The clear solution was injected into HPLC to determine caffeine content.   7) HPLC conditions: 25% MeOH+75% water, flow rate 1.0 mL/min, 254 nm, 15 cm C18 column. Caffeine retention time 4.3 min.       
 
         [0044]    The results were as follows: 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
               
               
                   
                 Initial 
                 Final 
                 % of 
               
               
                   
                 Caffeine 
                 Caffeine 
                 Caffeine 
               
               
                 Run 
                 Content 
                 Content 
                 Removal 
               
               
                   
               
             
             
               
                 1) Regular coffee 
                 3.22 mM 
                 — 
                 — 
               
               
                 2) Calgon Type TOG-NDG-LF-5 
                 3.22 mM 
                 0.43 mM 
                 87% 
               
               
                 (Fine powder) 
               
               
                 3) Norit GA830 (Granular) 
                 3.22 mM 
                 2.33 mM 
                 28% 
               
               
                 4) Norit GAC 1240 (Granular) 
                 3.22 mM 
                 2.11 mM 
                 34% 
               
               
                 5) Norit PAC 200 (Fine powder) 
                 3.22 mM 
                 0.14 mM 
                 96% 
               
               
                   
               
             
          
         
       
     
         [0045]    In operation, if a person wants to make a pot of regular caffeinated coffee, the caffeine filter  42  can be removed and the coffee maker  10  would operate in the traditional manner using standard ground coffee  20  and standard coffee filters  18 . Conversely, if a person wants to make a pot of decaffeinated coffee, regular ground coffee  20  can be placed into the brew chamber  16 . The caffeine filter  42  is set into its operational position within the filter chamber  34 . The coffee maker  10  is then operated in the traditional fashion. The brewed coffee  30  drips out of the brew chamber  16  and into the filter chamber  34 . In the filter chamber  34 , the brewed coffee  30  passes through the caffeine filter  42  and loses up to ninety percent of its caffeine, depending upon the filter used. The decaffeinated filtered coffee  50  then drips into the coffee pot  14 . 
         [0046]    It will also be understood that the coffee maker  10  can be filled with enough coffee to make two or more cups of coffee. The manual controls  32  can then be set to brew coffee one cup serving at a time. A coffee cup can be set in place of the coffee pot  14 . The first cup of coffee can be brewed without the caffeine filter  42  in place. Subsequent cups of coffee can then be brewed with the caffeine filter  42  in place. As a result, by filling a coffee maker  10  with regular ground coffee only once, cups of both regular caffeinated coffee and decaffeinated coffee can be selectively brewed. 
         [0047]    Referring now to  FIG. 3 , an alternate embodiment of the present invention coffee maker  52  is shown. In this embodiment, the coffee maker  52  is capable of changing the flow of brewed coffee  54  along one of two possible paths. In the first path, the brewed coffee  54  does not pass through a caffeine filter  56  and remains caffeinated. In the second path, the brewed coffee  54  passes through a caffeine filter  56  and becomes decaffeinated. 
         [0048]    In this embodiment, a filter chamber  58  is provided that is partitioned into an open section  59  and a filtered section  60 . Nothing is present in the open section  59 . Accordingly, any coffee flowing through the open section  59  would pass straight through the filter chamber  58  unaffected. Conversely, the caffeine filter  56  is positioned in the filtered section  60 . Consequently, any brewed coffee  54  that passes into the filtered section  60  would pass through the caffeine filter  56  and would therefore be decaffeinated. 
         [0049]    A deflector mechanism  62  is provided under the brew chamber  64 . The deflector mechanism  62  is controlled by at least one of the manual controls  67 . The deflector mechanism  62  can be used to selectively direct the brewed coffee  54  into either the open section  59  or the filtered section  60  of the filter chamber  58 . In this manner, a person can brew a cup or pot of decaffeinated coffee and then a cup or pot of regular coffee without having to add or remove any caffeine filter. The user need only push the proper button on the coffee maker  52 . 
         [0050]    It will therefore be understood that a caffeine filter  56  can be loaded into the coffee maker  52  at the beginning of a day. Prior to use, the caffeine filter  56  is wrapped in a protective package to prevent the caffeine filter  56  from interacting with gases in the air. The packaging is removed just prior to placing the caffeine filter  56  into the coffee maker  52 . Regular ground coffee  20  is filled into the brew chamber  64 . If a person wants regular coffee, that person does nothing but operate the coffee maker  52  in the traditional manner. If a person wants decaffeinated coffee, that person presses the appropriate “decaffeinated” button on the use interface. This changes the position of the deflector mechanism  62  and directs the brewed coffee  54  through the caffeine filter  56 . Decaffeinated coffee is then obtained. 
         [0051]    A single caffeine filter  56  can be made large enough to filter caffeine from multiple cups or pots of coffee. In this manner, a single caffeine filter  56  can be used to decaffeinate different cups or pots of coffee that are brewed at different times. However, for best decaffeination control, it is preferred that single use caffeine filter be used and that the caffeine filter be discarded after every use. 
         [0052]    Referring to  FIG. 4 , another embodiment of the present invention is shown. In this embodiment, the filter chamber and caffeine filter are removed from a coffee maker and are embodied in a handheld assembly  70 . The handheld assembly  70  contains a funnel shaped filter chamber  72 . A caffeine filter  74  is placed within the filter chamber  72 . A flow opening  76  is formed in the bottom of the filter chamber  72  below the caffeine filter  74 . The handheld assembly  70  is held over a coffee cup  78  so that the flow opening  76  is positioned over the coffee cup  78 . Brewed caffeinated coffee  80  is poured into the filter chamber  72 . The brewed coffee  80  flows through the caffeine filter  74  where most of the caffeine is removed. The filtered decaffeinated coffee  82  then flows into the coffee cup  78  through the flow opening  76 . Once the desired amount of filtered coffee  82  has flowed into the coffee cup  78 , the handheld assembly  70  is removed. 
         [0053]    Referring to  FIG. 5 , yet another embodiment of the present invention is shown. In this embodiment, a filter chamber  92  is designed into the neck  94  of a coffee pot  90 . The filter chamber  92  is shaped and sized to receive and retain a removable filter packet  96 . 
         [0054]    In the shown embodiment, the filter packet  96  contains two different compounds. In the top of the filter packet  96  is a volume of activated charcoal  98 . The activated charcoal  98  adsorbs caffeine, as has been previously described. Accordingly, it will be understood that when the filter packet  96  is in place, the activated charcoal  98  will adsorb caffeine from brewed coffee, both as the brewed coffee is dripped into the coffee pot  90  and as the brewed coffee is poured out of the coffee pot  90 . The caffeine filtration of the coffee both entering and leaving the coffee pot  90  increases the effectiveness of the caffeine removal. This results in coffee that is highly decaffeinated when finally poured into a cup. 
         [0055]    The second compound in the filter packet  96  is a flavorant  100 . The flavorant  100  adds a secondary flavor to the brewed coffee as the brewed coffee flows into and out of the coffee pot  90 . In this manner, different flavors can be added to different pots of coffee, even though only one type of coffee is being brewed. 
         [0056]    It will be understood that the filter packet  96  can contain only activated charcoal  98  or only flavorant  100 , and that the showing of both is only a convenience for this disclosure. 
         [0057]    It will be understood that the embodiments of the present invention that are illustrated and described are merely exemplary and that a person skilled in the art can make many variations to those embodiments. All such embodiments are intended to be included within the scope of the present invention as defined by the claims.