Abstract:
Aspects of the present disclosure relate to the brewing of beverages from a liquid, such as water, and a flavor base, such as tea, cocoa, or coffee. Specifically, aspects of the present disclosure enable the brewing of beverages with a level of precision that can yield a uniform taste from cup to cup, and at a rapid rate. In one embodiment, a liquid is heated in a reservoir to a predetermined temperature. Prior to brewing a beverage with the liquid, the liquid may be passed through a temperature control unit to cool the liquid to a desired brewing temperature. By utilizing such a temperature control unit, the brewing temperature can be varied on a per-beverage basis. Moreover, utilization of a temperature control unit can enable the liquid to be brought to a desired brewing temperature relatively rapidly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of, and thus claims the benefit of, U.S. patent application Ser. No. 12/976,663, which will issue as U.S. Pat. No. 8,371,211, entitled “MACHINE FOR BREWING A BEVERAGE SUCH AS COFFEE AND RELATED METHOD” and filed on Dec. 22, 2010, which in turn is a divisional of and claims the benefit of U.S. application Ser. No. 11/974,521, entitled “MACHINE FOR BREWING A BEVERAGE SUCH AS COFFEE AND RELATED METHOD” and filed on Oct. 11, 2007, which in turn is a continuation of PCT Application No. PCT/US2006/013930, designating the United States and filed on Apr. 11, 2006, which in turn claims the benefit of U.S. Provisional Application Nos. 60/670,955 filed on Apr. 11, 2005, 60/719,069 filed on Sep. 20, 2005, and 60/790,417 filed on Apr. 6, 2006. The disclosures of each of the foregoing applications are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Of the many techniques for brewing coffee, connoisseurs consider the French press technique to be one of the best for taste and efficient use of ground coffee (efficiency is proportional to the ratio of the amount of coffee brewed to the amount of ground coffee used). It is theorized that the good taste and efficiency is a result of the relatively thorough wetting of the coffee grounds that the French press technique allows. Wetting is function of the surface area of the coffee grounds in contact with water during the brewing time, and of the portion of the brewing time during which this contact occurs. The greater the contact area and contact time, the more thorough the wetting of the coffee grounds. 
     Referring to  FIGS. 1 and 2 , the French press technique is described. 
     Referring to  FIG. 1 , one places ground coffee  10  and hot water  12  in a coffee pot  14 , and allows coffee to brew. Because the ground coffee  10  often floats to the surface of the water  12 , one may stir or otherwise agitate the mixture of the ground coffee and the water to more thoroughly wet the individual coffee grounds that constitute the ground coffee. 
     Referring to  FIG. 2 , after the coffee  15  has brewed, one grasps a handle  16  of a filter  18 , inserts the filter into the coffee pot  14 , and presses the filter down toward the bottom of the pot. 
     Because the filter  18  passes liquid but does not pass coffee-ground-sized particles, as one presses the filter toward the bottom of the coffee pot  14 , the substantially ground-free brewed coffee  15  fills the portion of the pot above the filter while the filter retains the ground coffee  10  in the portion of the pot below the filter. Of course the edge  20  of the filter  18  and the inner side  22  of the pot  14  form a seal sufficient to prevent coffee grounds from passing between the edge of the filter and the inner side of the pot. 
     After one presses the filter  18  below a spout  24  of the coffee pot  14 , he can pour the substantially ground-free brewed coffee  15  into a cup (not shown in  FIGS. 1 and 2 ) via the spout. Although ideally one may stop pressing the filter  18  after the filter is below the spout  24 , one typically presses the filter all the way to the bottom of the coffee pot  14  to reduce the chances of undersized coffee grounds passing through the filter and into the cup. 
     Still referring to  FIG. 2 , after one pours the desired amount of brewed coffee  15 , he retracts the filter  18  from the pot  14  by pulling on the handle  16 , removes the ground coffee  10  from the pot, and then cleans the filter and the pot. 
     Unfortunately, a problem with the above-described French press technique is that it is often too time consuming and difficult for use by establishments, such as coffee shops, restaurants, and work places, that serve significant amounts of coffee. The taste of brewed coffee typically depends on the brew parameters, which include the size of the coffee grounds (i.e., the grind size or consistency), the water temperature, the ratio of ground coffee to water, and the brew time. Even a slight variation in one of the brew parameters may cause a noticeable change in the taste of the brewed coffee. Because one typically controls at least some of the French press brewing parameters manually using equipment not shown in  FIGS. 1-2  (e.g., coffee grinder, thermometer, measuring cup), it is often difficult and time consuming to control these brewing parameters, particularly with the level of precision required to brew many pots of coffee having a substantially uniform taste from pot to pot. And because each cup of brewed coffee poured from the same pot typically sat in the pot for a different length of time, the taste of the brewed coffee may even change significantly from cup to cup. 
     SUMMARY OF THE INVENTION 
     An embodiment of a machine for brewing a beverage such as coffee includes a chamber and a piston disposed in the chamber. The piston is operable to move to a first position to allow the chamber to receive a liquid and a flavor base such as ground coffee, to remain in the first position for a time sufficient for a beverage to brew, and to move to a second position to dispense the beverage by forcing the beverage out of the chamber. 
     By modifying or automating some or all steps of the French press brewing technique, such a machine can typically control the brewing parameters with a level of precision that yields brewed coffee having a uniform taste from cup to cup, and can typically brew the coffee with a speed that renders the machine suitable for use by establishments that serve significant amounts of coffee. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1-2  illustrate a conventional French press technique for brewing coffee. 
         FIG. 3  is a block diagram of a machine for brewing a beverage such as coffee using a modified French press technique according to an embodiment of the invention: 
         FIG. 4  is a cut-away side view of the brewing unit of  FIG. 3  according to an embodiment of the invention. 
         FIG. 5  is an exploded isometric view of the filter and wiper shuttle assembly of  FIG. 4  according to an embodiment of the invention. 
         FIGS. 6A-6B  are side views of the filter and wiper shuttle assembly of  FIGS. 4-5  according to an embodiment of the invention. 
         FIGS. 7A-7C  are side views of the filter and wiper shuttle assembly of  FIGS. 4-6B  and of a filter and wiper cleaning assembly according to an embodiment of the invention. 
         FIG. 8  is an isometric view of the filter and wiper cleaning assembly of  FIGS. 7A-7C  according to an embodiment of the invention. 
         FIG. 9  is a block diagram of the grinding-and-measuring unit of  FIG. 3  according to an embodiment of the invention. 
         FIG. 10  is a cut-away side view of the measuring assembly of the grinding-and-measuring unit of  FIG. 9  according to another embodiment of the invention. 
         FIG. 11  is a cut-away side view of the measuring assembly of the grinding-and-measuring unit of  FIG. 9  according to yet another embodiment of the invention. 
         FIG. 12  is a block diagram of the brewing chamber of  FIG. 4  and the measuring assembly of the grinding-and-measuring unit of  FIG. 9  according to still another embodiment of the invention. 
         FIGS. 13-18  illustrate a brewing cycle of the beverage-brewing machine of  FIG. 3  according to an embodiment of the invention. 
         FIG. 19  is a perspective view of the beverage-brewing machine of  FIG. 3  according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following discussion is presented to enable a person skilled in the art to make and use one or more embodiments of the invention. The general principles described herein may be applied to embodiments and applications other than those detailed below without departing from the spirit and scope of the invention. Therefore the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed or suggested herein. 
       FIG. 3  is a block diagram of a machine  30  for brewing a beverage according to an embodiment of the invention. The beverage-brewing machine  30  can brew coffee one cup at a time using an automated and modified French press technique, which allows the machine to brew coffee more quickly and more uniformly from cup to cup than can a human operator performing the conventional French press technique described above in conjunction with  FIGS. 1-2 . Consequently, the machine  30  is often more suitable for establishments that brew and serve significant amounts of coffee than is a human operator performing the conventional French press technique. 
     The machine  30  includes the following components: a water filter  32 , cleaner-dispensing unit  34 , water-reservoir-and-heating unit  36 , water-temperature-control unit  38 , water-and-cleaner-measuring-and-transporting unit  40 , liquid-waste-disposal unit  42 , cup-holder-and-overflow/waste-drain unit  44 , beverage-dispensing unit  46 , beverage-transporting unit  48 , beverage-brewing unit  50 , cup-sensing unit  52 , grind-transporting unit  54 , solid-waste-disposal unit  56 , hopper unit  58 , grinding-and-measuring unit  60 , barrier  62 , and controller  64 . And although the machine  30  may brew beverages (e.g., tea, cocoa) other than coffee, for purposes of explanation the structure and operation of the machine are described in conjunction with the machine brewing coffee. 
     The water filter  32  filters the water that is used to brew the coffee. But one may omit the filter  32  from the beverage-brewing machine  30 , particularly where the machine is installed in an establishment that has a water-purification system separate from the machine. 
     The cleaner-dispensing unit  34  stores a cleaning solution that the beverage-brewing machine  30  may use to clean some of the above-described components during a cleaning cycle, which is described in more detail below in conjunction with  FIG. 16 . Suitable cleaning solutions include vinegar, ammonia, soap-based solutions, and mixtures thereof. 
     The water-reservoir-and-heating unit  36  receives and stores water from the water filter  32 , and, under the control of the controller  64 , heats the stored water to a desired temperature, for example a temperature in the range from 150° F. to just below the boiling point of water. The heating element may be electric or any other type of conventional heating element, and a sensor (not shown in  FIG. 3 ) indicates to the controller  64  the temperature of the water in the reservoir. In one implementation, the capacity of the reservoir and the thermal output of the heating element are such that the machine  30  can brew a 16 ounce cup of coffee in approximately 50 seconds, and can brew ten 16 ounce cups of coffee in approximately 10 minutes. Alternatively, the reservoir-and-heating unit  36  may include a manually settable thermostat that maintains the temperature of the water at the temperature to which the thermostat is set. 
     The water-temperature-control unit  38  can alter the temperature of the water from the reservoir unit  36  to allow a different brew temperature from cup to cup. The temperature-control unit  38  receives water from the reservoir  36  during a beverage-brewing cycle, and, in response to the controller  64 , adjusts the temperature of the water received from the reservoir. In one implementation, the temperature-control unit  38  mixes the heated water from the reservoir  36  with colder water from the filter  32  to lower the temperature of the water used to brew coffee from the temperature of the water in the reservoir. The temperature-control unit  38  may operate in an open-loop configuration by relying on a thermodynamic algorithm that, using the sensed temperatures of the heated and cold water, regulates the amount of cold water mixed with the heated water to provide water having a desired temperature. Alternatively, the temperature control unit  38  may operate in a closed-loop configuration by sensing the temperature of the provided water and, in response to the sensed temperature, regulating the amount of cold water mixed with the heated water to provide water having the desired temperature. Moreover, instead of actually mixing cold tap water from the filter  32  with the heated water, the temperature-control unit  38  may include a heat exchanger that allows the cold water to cool the heated water without actually mixing with the heated water. The temperature control unit  38  may also be able to heat the water used to brew the coffee above the temperature of the water in the reservoir  36 . 
     Alternatively, one may omit the water-temperature-control unit  38  from the machine  30 , and depend on the reservoir-and-heating unit  36  to heat the water to the desired temperature. An advantage of the temperature-control unit  38  is that it provides water at the desired brew temperature relatively quickly if the water in the reservoir  36  is at or higher than the desired brew temperature; a disadvantage is that the unit  38  may add complexity and expense to the machine  30 . Comparatively, although omitting the temperature-control unit  38  may slow the machine&#39;s brewing speed, the reservoir-and-heating unit  36  can heat the water used to brew each cup of coffee from a base temperature to any desired brewing temperature under software control (via the controller  64 ) without adding any expense or complexity to the machine. Typically, the cold tap water entering the reservoir  36  to replace the expelled brew water drops the temperature of the water in the reservoir to or below the baseline temperature, thus readying the reservoir for the next cup. 
     The water-and-cleaner-measuring-and-transporting unit  40  transports a predetermined amount of water from the temperature-control unit  38  to the brewing unit  50  during a brewing cycle, and transports a predetermined amount of cleaning solution to the brewing unit during a cleaning cycle. The measuring-and-transporting unit  40  may also direct liquid waste from the brewing unit  50  to the liquid-waste disposal unit  42  as discussed below in conjunction with  FIGS. 13-18 . The unit  40  includes one or more electronically controllable valves, which, in response to the controller  64 , direct the water, cleaning solution, and liquid waste as described above and as described below in conjunction with  FIGS. 13-18 . Furthermore, the unit  40  measures the water and cleaning solution transported to the brewing chamber  50  as described below in conjunction with  FIGS. 13-18 . Moreover, the unit  40  may provide hot water directly to the beverage dispensing unit  46  so that one can obtain hot water for any desired use. 
     The liquid-waste disposal unit  42  receives liquid waste from the measuring-and-transporting unit  40  and disposes of this waste. The disposal unit  42  may include a drain (not shown in  FIG. 3 ) that is connected to the sewer line (not shown in  FIG. 3 ) of the establishment in which the machine  30  is installed. Alternatively, the disposal unit  42  may receive liquid waste from the beverage transporting unit  48  or from another component of the machine  30 . 
     The cup-holder-and-overflow/waste-drain unit  44  holds a cup (not shown in  FIG. 3 ) while the beverage-dispenser unit  46  fills the cup with the brewed beverage (or hot water as described above). The unit  44  also includes a drain portion to absorb, e.g., spillage from the cup and drippings from the dispenser unit  46  after the cup has been removed. The drain portion of the unit  44  may be removable for emptying, or may be connected to the liquid-waste disposal unit  42  or directly to the sewer line of the establishment in which the machine  30  is installed. 
     The beverage-dispensing unit  46  includes a spout (not shown in  FIG. 3 ), and dispenses the brewed beverage into the cup (not shown in  FIG. 3 ) as discussed in the preceding paragraph. 
     The beverage-transporting unit  48  transports the brewed beverage from the brewing unit  50  to the dispensing unit  46 . The unit  48  may include an electronically controllable valve (not shown in  FIG. 3 ), which, in response to the controller  64 , opens after the brewing unit  50  has brewed the beverage to allow the beverage to flow to the dispensing unit  46 . To prevent the dispensing unit  46  from dispensing a beverage when no cup is present, the controller  64  may close the valve if the cup sensor  52  indicates that no cup is present in the cup-holder portion of the unit  44 . The controller  64  may also close the valve at other times as described below in conjunction with  FIGS. 13-18 . 
     The beverage-brewing unit  50  receives heated water from the measuring-and-transporting unit  40 , receives ground coffee from the grind-transporting unit  54 , brews coffee, and then provides the brewed coffee to the beverage-dispensing unit  46  via the beverage-transporting unit  48 . The brewing unit  50  is further described below in conjunction with  FIGS. 4-8  and  13 - 18 . 
     As discussed above, the cup-sensing unit  52  indicates to the controller  64  whether a cup (not shown in  FIG. 3 ) is present in the cup holder  44 . If the cup is not present after the brewing unit  50  has brewed coffee, then the controller  64  may deactivate the beverage-transporting unit  48  to prevent the beverage-dispensing unit  46  from dispensing brewed coffee directly into the drain portion of the drain unit  44 . Alternatively, if the cup is present during a cleaning cycle, then the controller  64  may deactivate the beverage-transporting unit  48  to prevent cleaning solution from entering the cup. The cup-sensing unit  52  may include any type of sensor, such as an optical, mechanical, or ultrasonic sensor. 
     The grind-transporting unit  54  may include one or more electronically controllable valves, which, in response to the controller  64 , route ground coffee from the grinding-and-measuring unit  60  to either the brewing unit  50  or to the solid-waste-disposal unit  56 . The controller  64  may cause the unit  54  to route ground coffee to the disposal unit  56  when one wishes to “grind through” the remaining coffee beans in a hopper (not shown in  FIG. 3 ) of the hopper unit  58  before filling the hopper with new coffee beans. Such grinding through may prevent cross contamination between different types of coffee beans. 
     The solid-waste disposal unit  56  receives “ground through” coffee from the grind-transporting unit  54  per the preceding paragraph, and receives spent coffee grounds and disposable filters (if used) from the brewing unit  50  as discussed below. The disposal unit  56  may include a receptacle that one periodically removes for emptying, or that is connected to an electronic garbage disposer or directly to the sewer line of the establishment in which the machine  30  is installed. In addition, the solid-waste-disposal unit  56  may be connected to receive tap water, and may use the tap water to flush “ground-through” and spent coffee from the disposal unit into the garbage disposer unit or directly into the sewer line. The disposal unit  56  may periodically commence an automatic flushing sequence, e.g., after brewing each cup of coffee. Or, one may commence the flushing sequence manually. 
     The hopper unit  58  includes one or more hoppers for holding coffee beans (neither shown in  FIG. 3 ), which are gravity fed to the grinding-and-measuring unit  60 . Where the hopper unit  58  includes multiple hoppers, then one can load different types of coffee beans into each hopper, thus providing the coffee drinker with a selection of coffees. In one implementation, each hopper can hold slightly more than one pound of coffee beans, e.g., 1¼ pounds. Because coffee beans typically come in one-pound containers, a hopper having a greater-than-one-pound capacity allows one to refill the hopper with a whole container of coffee beans before the hopper is completely empty. 
     In response to the controller  64 , the grinding-and-measuring unit  60  grinds coffee beans (not shown in  FIG. 3 ) from the hopper unit  50 , and then provides to the grind-transporting unit  54  a predetermined amount of ground coffee. In one implementation, the grinding-and-measuring unit  60  continually indicates to the controller  64  the rate at which the unit is generating ground coffee, and the controller keeps track of the cumulative amount of ground coffee generated. When the cumulative amount of ground coffee equals a predetermined amount, then the controller  64  deactivates the unit  60 . Techniques for indicating the rate at which the unit  60  generates ground coffee and other techniques for measuring the ground coffee are discussed below in conjunction with  FIGS. 9-12 . Furthermore, the unit  60  may allow one to select, via the controller  64 , one of multiple grind sizes (e.g., coarse, normal, fine), as the grind size may affect the taste and other characteristics of the brewed coffee. 
     The barrier  62  separates the controller  64  and associated circuitry (not shown in  FIG. 3 ) from other components of the machine  30 . For example, steam from hot water and brewing or brewed coffee may condense and damage or otherwise render inoperable the controller  64 . Furthermore, condensation on the conduits that carry cold tap water may cause similar problems. Therefore, a moisture barrier  62  helps keep the controller  64  and associated circuitry dry. 
     The controller  64  controls the operation of some or all of the other components of the brewing machine  30  as discussed above, and includes a processor  66 , a memory  68 , a control panel and display  70 , and a communications port  72 . 
     The processor  66  executes a software program stored in the memory  68  or in another memory (not shown), and controls the operations of the components of the machine  30  as described above and as described below. 
     In addition to storing one or more software programs, the memory  68  may store sets of predetermined brew parameters as discussed below in conjunction with  FIGS. 13-18 , and may provide working memory for the processor  66 . 
     The control panel and display  70  allows an operator (not shown in  FIG. 3 ) to enter brewing options (e.g., coffee type, cup size, and brewing parameters) or to select brewing options from a menu that the processor  66  may generate on the display. For example, the operator may select via the control panel and display  66  individual brewing parameters (e.g., grind size, water temperature, brewing time, and the coffee-ground-to-water ratio), or a set of predetermined brewing parameters stored in the memory  68 . As an example of the latter, a coffee roaster may have determined preferred brewing parameters for its coffee. One may then store these preferred parameters in the memory  68  as a set, and associate the set with an identifier, such as the name or type of the coffee. Therefore, instead of entering or selecting each brewing parameter individually, which may be tedious, the operator merely enters or selects from a menu the identifier, and the controller  64  causes the machine  30  to brew coffee according to the set of parameters corresponding to the identifier. 
     The communications port  72  allows the processor  66 , memory  68 , and control panel and display  70  to communicate with one or more devices external to the machine  30 . For example, the port  72  may be connected to a computer (not shown in  FIG. 3 ) so that one can program or run diagnostics from the computer. Or, the port  72  may be connected to the internet, so that one can download into the memory  68  data such as sets of brewing parameters from coffee roasters or suppliers. In addition, the port  72  may receive data via a wireless channel, such as a set of brewing parameters from a RFID tag or a barcode on a container of coffee or on a coffee cup (the tag may hold the cup owner&#39;s preferred coffee type, cup size, or brew parameters). Furthermore, the port  72  may allow the processor  66  to download demographic information, such as coffee-drinker preferences and number of cups brewed, to a coffee roaster or supplier or to the manufacturer/supplier of the machine  30 . 
     Still referring to  FIG. 3 , alternate embodiments of the machine  30  are contemplated. For example, one or more of the above-described units or components may be omitted, the function of multiple units may be consolidated into fewer units, or the function of a single unit may be divided among multiple units. 
       FIG. 4  is a cut-away side view of the beverage-brewing unit  50  of  FIG. 3  according to an embodiment of the invention. As discussed above in conjunction with  FIG. 3 , the brewing unit  50  allows the machine  30  to brew coffee according to a modified French press technique. 
     The beverage-brewing unit  50  includes a brewing chamber  80  having a top opening  82  and a side wall  84  and disposed in a chamber block  86  having a top surface  88 , a piston  90  disposed within the chamber and having a top surface  92  and side  94 , a motor  96  for driving the piston, and a filter and wiper shuttle assembly  98 . The shuttle assembly  98  is illustrated in a disengaged position in which it is not sealing the opening  82 . In a closed position (not illustrated in  FIG. 4 ), the shuttle assembly  98  covers and seals the opening  82  while coffee brews in the chamber  80 . 
     The brewing chamber  80 , which may be cylindrical, holds the ground coffee and water (neither shown in  FIG. 4 ) while the coffee brews. One may design the shape and other features of the chamber  80  to promote agitation of the water-and-ground-coffee mixture as discussed below. 
     The piston  90  is the same shape as the brewing chamber  80 , the side  94  of the piston forms a water-tight seal with side wall  84  of the brewing chamber, and the motor  96  moves the piston up and down within the chamber. The motor  96 , which is responsive to the controller  64  ( FIG. 3 ), may be any motor, such as a stepper motor, suitable to drive the piston  90 , and may include a sensor, such as one or more limit switches, that indicates to the controller the position, speed, and traveling direction of the piston. 
     The shuttle assembly  98  includes an inlet  100 , a nozzle  102 , separator ribs  104 , a filter  106 , an outlet  108 , and a wiper  110 . A shuttle-assembly driver (not shown in  FIG. 4  but described below in conjunction with  FIGS. 7A-7C ) moves the shuttle assembly  98  across the chamber opening  82 , and causes the shuttle assembly to seal the chamber opening while coffee is brewing in the chamber  80 . 
     The inlet  100  is a conduit that routes hot water or cleaning solution from the water-measuring-and-transporting unit  40  ( FIG. 3 ) to the nozzle  102 . 
     The nozzle  102  directs the water from the inlet  100  in a spray pattern to agitate the mixture of the water and the ground coffee (not shown in  FIG. 4 ) within the chamber  80  so that the coffee grounds are more thoroughly wetted. For example, the nozzle  102  may create a pattern that causes the mixture of water and coffee grounds within the chamber  80  to swirl around as if one were stirring the mixture. Moreover, the water-measuring-and-transporting unit  40  ( FIG. 3 ) may include a pump or other device that can, in response to the controller  64  ( FIG. 3 ), impart a predetermined pressure to the water in the inlet  100  to increase the agitation of the water-and-coffee-ground mixture. The nozzle  102  may also hold the filter  106  in place as discussed below in conjunction with  FIG. 5 . Furthermore, the nozzle  102  may be positioned such that it is in the center of the chamber opening  82  when the shuttle assembly covers the brewing chamber  80 , or may be positioned in any non-centered location. Moreover, the nozzle  102  may cause the water to enter the chamber at an angle to promote agitation of the water-and-coffee-ground mixture as discussed above. 
     The separator ribs  104  create a space  112  between the filter  106  and a bottom surface  114  of the shuttle assembly  98  to facilitate the flow of brewed coffee from the chamber  80  to the outlet  108 . The ribs  104  may be attached to or integral with either the filter  106  or the bottom surface  114 . 
     The filter  106  effectively separates spent coffee grounds from brewed coffee. After the coffee brews in the chamber  80 , the motor  96  extends the piston  90  upward at a controlled speed to force the brewed coffee through the filter  106 , into the space  112 , and to the beverage-transporting unit  48  ( FIG. 3 ) via the outlet  108 . Although the filter  106  passes liquid (in this case brewed coffee), it does not pass solids (in this case coffee grounds) having a grain size greater than a predetermined diameter. Therefore, the filter  106  retains the coffee grounds in the chamber  80  so that the grounds do not contaminate the dispensed brewed coffee. 
     The wiper  110  transports the spent coffee grounds from the brewing unit  50  into the solid-waste disposal unit  56  ( FIG. 3 ). Specifically, after the piston  90  extends to force the brewed coffee out of the chamber  80  as discussed in the preceding paragraph, the controller  64  ( FIG. 3 ) causes the shuttle-assembly driver (not shown in  FIG. 4 ) to raise the shuttle assembly  98  a predetermined distance so that the bottom edge of the wiper  110  is substantially even with the surface  88  of the chamber block  86 . Next, the controller  64  causes the motor  96  to further extend the piston  90  until the surface  92  of the piston is substantially coplanar with the surface  88 . Then, the controller  64  causes the shuttle-assembly driver to move the shuttle assembly  98  in a direction (here to the right of  FIG. 4 ) that is substantially perpendicular to the direction in which the piston  90  moves such that the wiper  110  sweeps the spent coffee grounds from the piston surface  92 , onto the surface  88 , and into the solid-waste-disposal unit  56  ( FIG. 3 ). As discussed below in conjunction with  FIGS. 7A-7C , the brewing unit  50  may also include a cleaning assembly for cleaning the wiper  110  and the filter  106 . 
     To provide a more precise control of the brewing temperature, the brewing unit  50  may include a temperature sensor and a heating/cooling mechanism (neither shown in  FIG. 4 ). The heating/cooling mechanism may be, e.g., electric or gas. Alternatively, the heating/cooling mechanism may include a water jacket that is disposed along the side wall  84  of the chamber  80 , or on the outside of the chamber block  86 . To heat the water-and-ground-coffee mixture with the chamber  80 , the machine  30  ( FIG. 3 ) fills the jacket with hot water from the reservoir  36  ( FIG. 3 ) or from another source; similarly, to cool the mixture the machine  30  fills the jacket with cold water from the filter  32  or directly from the tap. Using the temperature sensor, the controller  64  may implement closed-loop control of the brewing temperature by regulating the flow of water through the jacket. 
       FIG. 5  is a perspective view of the shuttle assembly  98  of  FIG. 4  according to an embodiment of the invention where the brewing chamber  80  of  FIG. 4  is cylindrical. 
     The filter  106  may be a screen made of metal or of another suitable material, may be made from a cloth or from paper, or may be a combination of a screen to filter larger coffee grounds and cloth/paper to filter smaller coffee grounds. The filter  106  and space  112  are the same shape as the chamber opening  82 . Furthermore, the filter  106  may be flat, or may be slightly concave with an inner curvature facing the chamber  80 . 
     The separating ribs  104  are arranged to form a manifold. That is, the ribs  104  are arranged so that they direct brewed coffee flowing from the chamber  80  through the filter  106  into the outlet  108 . 
     The inlet  100  and nozzle  102  are threaded so that one can screw the nozzle into the inlet; and, as discussed above in conjunction with  FIG. 4 , the nozzle secures the filter  106  when the nozzle is screwed into the inlet. 
     In addition to the inlet  100 , the nozzle  102 , the ribs  104 , the filter  106 , the outlet  108 , and the wiper  110 , the shuttle assembly  98  includes a gasket  120 , upper and lower portions  122  and  124 , linkage members  126  and  128 , which connect the upper and lower portions, and track guides  130 ,  132 ,  134 ,  135 , and  137  (the counterparts to the guides  134 ,  135 , and  137  are not present in  FIG. 5 ). 
     Referring to  FIGS. 4 and 5 , the gasket  120  forms a water-tight face seal around the perimeter of the chamber opening  82  while the water-measuring-and-transporting unit  40  introduces water into the brew chamber  80 , while the coffee brews, and while the piston  90  ( FIG. 4 ) extends to dispense the brewed coffee. Alternatively, the shuttle assembly  98  may be designed to make a bore seal with the chamber opening  82 . 
     The upper and lower portions  122  and  124 , the linkage members  126  and  128 , and the track guides  130 ,  132 ,  134 ,  135 , and  137  are further described below in conjunction with  FIGS. 6A and 6B . 
       FIG. 6A  is a cut-away side view of the brewing unit  50  and the shuttle assembly  98  disengaged from the brewing unit according to an embodiment of the invention. While disengaged, the lower portion  122  of the shuttle assembly  98  is raised substantially the thickness of the wiper  110  above the surface  88  of the chamber block  86  such that the gasket  120  ( FIG. 5 ) is spaced from the surface of the chamber block, and thus does not seal the chamber opening  82 . Consequently, the wiper  110  can sweep the spent coffee grounds (not shown in  FIG. 6A ) off of the piston  90  as discussed above in conjunction with  FIG. 4 . The upper track guides including guides  130 ,  132 , and  134  ( FIG. 5 ) engage an upper track  136 , and the lower track guides including guides  135  and  137  engage a lower track  138 . The upper and lower tracks  136  and  138  are part of a shuttle-assembly drive, which is further described below in conjunction with  FIGS. 7A-7C . The upper guides  130 , and  132 , and  134  allow the upper portion  122  of the shuttle assembly  98  to move back and forth along the upper track  136 , and the lower guides  135  and  137  allow the lower portion  124  of the shuttle assembly to move back and forth along the lower track  138 . Furthermore, while the shuttle assembly  98  is disengaged from the brewing unit  50 , the linkage members  126  and  128  make an acute angle relative to the upper track  136 . 
       FIG. 6B  is a cut-away side view of the brewing unit  50  and the shuttle assembly  98  engaged with the brewing unit  50  according to an embodiment of the invention. In this position, the lower track guides including the guides  135  and  137  engage vertical portions  140  and  142  of the lower track  138 , and force the lower portion  122  of the shuttle assembly  98  against the surface  88  of the chamber block  86  such that the gasket  120  ( FIG. 5 ) seals the chamber opening  82 . 
     Referring to  FIGS. 6A and 6B , the operation of the shuttle assembly  98  is described according to an embodiment of the invention. 
     After the grind-transporting unit  54  ( FIG. 3 ) loads ground coffee into the chamber  80  via the opening  82 , the shuttle assembly  98  moves leftward from its position in  FIG. 6A . 
     When the lower track guides  135 ,  137 , etc. respectively engage the vertical portions  140  and  142 , the linkage members straighten, and thus force the lower portion  122  of the shuttle assembly  98  toward and against the surface  88  such that the gasket  120  ( FIG. 5 ) seals the brewing chamber  80 . 
     After the coffee brews, the piston  90  ( FIG. 4 ) extends to dispense the brewed coffee from the chamber  80 . Because the tracks  136  and  138  compose an over-the-center-toggle configuration, the pressure generated against the lower portion  22  by the piston  90  forces the shuttle assembly  98  to the left. But because the shuttle assembly  98  can travel little or no distance to the left, the shuttle assembly remains in the engaged position of  FIG. 6B . Therefore, the tracks  136  and  138  implement a stable seal, because even in the absence of force on the shuttle assembly  98  in the leftward direction, pressure within the chamber  80  will reinforce the seal, and will not cause the seal to “blow” by forcing the shuttle assembly  98  rightward. 
     After the piston  90  dispenses the brewed coffee, the shuttle assembly  98  moves rightward from its position in  FIG. 6B . As the shuttle assembly  98  moves rightward, the lower track guides  135 ,  137 , etc. disengage the vertical portions  140  and  142  such that the lower portion  122  of the shuttle assembly  98  moves upward and away from the surface  86 . Vertically engaging and disengaging the chamber opening  82  may significantly extend the life of the gasket and other components that form the seal with the chamber opening of the chamber. 
     Next, the piston  90  ( FIG. 4 ) extends further until the piston surface  92  ( FIG. 4 ) is substantially coplanar with the surface  86 . While the piston  90  is extending further, the shuttle assembly  98  may temporarily halt its rightward movement. 
     Then, as the shuttle assembly  98  continues moving rightward, the wiper  110  wipes the used coffee grounds (not shown in  FIGS. 6A and 6B ) off of the piston surface  92  and into the solid-waste-disposal unit  56  ( FIG. 3 ). 
     After the wiper  110  moves past the edge of the surface  88 , the shuttle assembly  98  stops, and remains in this “home” position (not shown in  FIGS. 6A and 6B ) until the brewing chamber  80  brews another cup of coffee, at which time the shuttle assembly repeats the above-described sequence. 
       FIG. 7A  is side view of a portion of the brewing unit  50 , the shuttle assembly  98  in a first disengaged position, and a shuttle-assembly drive  150  according to an embodiment of the invention. 
     The shuttle-assembly drive  150  may include a drive belt  152 , drive gears  154  and  156 , an attachment member  158 , a solenoid plunger  160 , and a cleaning assembly  162 , which includes a scraper  164 , optional water jets (not shown in  FIG. 7A ), and pivots  166  (only one shown in  FIG. 7A ). The plunger  160  is operable to engage and disengage the cleaning assembly  162  as described below in conjunction with  FIGS. 7A-8 . 
     The member  158  attaches the shuttle assembly  98  to the belt  152 , and the drive gears  154  and  156  turn clockwise to move the shuttle assembly to the left, and turn counterclockwise to move the shuttle assembly to the right. The shuttle-assembly drive  150  may also include one or more stops (not shown) to limit the distance that the shuttle assembly  98  can move in the left or right directions. In one implementation, the ends of the tracks  136  and  138  ( FIGS. 6A-6B ) provide such stops. 
       FIGS. 7B and 7C  show rightward movement of the shuttle assembly  98  relative to the shuttle assembly&#39;s position in  FIG. 7A  according to an embodiment of the invention. 
       FIG. 8  is an isometric view of the cleaning assembly  162  of  FIGS. 7A-7C  according to an embodiment of the invention. The scraper  164  may be made out of metal, rubber, or any other suitable material, and is disposed over the solid waste disposal unit  56  ( FIG. 3 ). And if the filter  106  ( FIGS. 4-7C ) is concave, the scraper  164  has the same contour so that it can contact the filter across its entire diameter. In addition to the scraper  164  and the pivots  166 , the cleaning assembly  162  may include water jets  168 , which are adjacent to the scraper. Although not shown, the water-measuring-and-transporting unit  40  ( FIG. 3 ) may feed to the jets  168  heated water from the reservoir  36  ( FIG. 3 ), or may feed to the jets heated water from the reservoir mixed with cleaning solution from the cleaner-dispensing unit  34  ( FIG. 3 ). Flexible tubing or another type of conduit may connect the water-measuring-and-transporting unit  40  to the water jets  168 . Alternatively, the water jets  168  may be fed directly from the tap-water inlet ( FIG. 3 ) or from another water or cleaning-solution source. 
     Referring to  FIGS. 7A-8 , the operation of the cleaning assembly  162  is described according to an embodiment of the invention. 
     The scraper  164  and water (or cleaning solution) discharged from the water jets  168  clean the filter  106  and the wiper  110 . 
     As discussed above in conjunction with  FIGS. 6A-6B  and as shown in  FIG. 7A , after the brewing unit  50  brews coffee, the shuttle-assembly drive  150  moves the shuttle assembly  98  upward and to the right such that the wiper  110  begins sweeping the spent coffee grounds from the surface  92  of the piston  90  into the solid-waste-disposal unit  56 . 
     In addition, the controller  64  ( FIG. 3 ) extends the plunger  160  toward the brewing unit  50  to rotate the cleaning assembly  162  about the pivots  166  such that the top edge of the scraper  164  is substantially coplanar with the underside of the filter  106 . The solenoid plunger may be designed to extend no further than the desired position, or a sensor (not shown) may indicate to the controller  64  when the scraper  164  is in the desired position. Alternatively, the plunger may not be a solenoid plunger, but may instead be a spring-loaded plunger that forces the cleaning assembly  162  into the proper position. 
     Referring to  FIG. 7B , as the shuttle assembly  98  continues to move rightward, the scraper  164  contacts the underside of the filter  106  and dislodges spent coffee grounds and, if present, other residue (neither shown in  FIGS. 7A-7C ) that stuck to the underside of the filter as the piston  90  was forcing brewed coffee through the filter. Water (or cleaning solution) discharged from the jets  168  facilitates the dislodging of the spent coffee grounds and residue from the filter  106 , and, depending on the jets&#39; spray pattern, may also keep the scraper  164  free of coffee grounds and other residue. Because the scraper  164  and jets  168  are positioned over the solid-waste-disposal unit  56  ( FIG. 3 ), the dirty water, dislodged coffee grounds, and other residue fall into the disposal unit. And if the filter  106  includes a disposable cloth or paper portion on its underside, then the scraper  164  may also remove this portion such that it falls into the disposal unit  56  along with the spent coffee grounds and other residue. 
     Referring to  FIG. 7C , after the filter  106  moves over the scraper  164 , the wiper  110  moves over the scraper, which contacts the bottom of the wiper. The scraper  164 , together with water (or cleaning solution) discharged from the jets  168 , dislodges spent coffee grounds and, if present, other residue stuck to the wiper. As discussed above, because the scraper  164  and the jets  168  are positioned over the solid-waste-disposal unit  56  ( FIG. 3 ), the coffee grounds and other residue dislodged from the wiper  110  fall into the disposal unit. After the wiper  110  moves rightward past the scraper  164 , the jets  168  may continue to discharge water to dislodge coffee grounds, and, if present, other residue from the scraper, such that the dirty water and dislodged material fall into the solid-waste-disposal unit  56 . 
       FIG. 9  is a block diagram of the grinding-and-measuring unit  60  of  FIG. 3  according to an embodiment of the invention. 
     The grinding-and-measuring unit  60  includes an electric motor  170  that is powered by a supply voltage V and that is responsive the controller  64  ( FIG. 3 ), a shaft  172 , a grinder  174 , and a discharge port  176 . The grinding-and-measuring unit may also include a current sensor  178  or a temperature sensor  180 . 
     The motor  170  drives the grinder  174  via the shaft  172  in response to the controller  64  ( FIG. 3 ). 
     The grinder  174  may be any suitable device for grinding coffee beans or another substance from which a beverage may be brewed. 
     The discharge port  176  provides the ground coffee from the grinder  174  to the grind-transporting unit  54  ( FIG. 3 ), or directly to the beverage-brewing unit  50  ( FIG. 3 ) if the brewing machine  30  ( FIG. 3 ) lacks the grind-transporting unit. 
     The current sensor  178  generates and provides to the controller  64  ( FIG. 3 ) a signal that indicates the amount of current that the motor  172  draws, and the temperature sensor  180  generates and provides to the controller a signal that indicates the temperature of the motor. 
     In operation, the controller  64  ( FIG. 3 ) determines that the amount of ground coffee discharged from the port  176  equals the product of the grind rate of the grinder  174 —the grind rate may be stored in the controller memory  68 —and amount of time that the motor  170  is “on”. Because the instantaneous grind rate of the grinder  174  may depend on the amount of material that the grinder is grinding, and thus discharging through the port  176 , at that instant, the controller  64  may also base the ground-coffee measurement on the current that the motor  170  draws, on the temperature of the motor, or both the current drawn and the temperature. At any one instant, the load on the motor  170  is proportional to the amount of ground coffee that the grinder  176  discharges through the port  176 , and the current that the motor draws is proportional to the load. Therefore, the higher that rate at which the grinder  174  discharges ground coffee through the port  176 , the higher the load on the motor  170 , and thus the higher the current that the motor draws. Furthermore, the grind rate is proportional to the motor efficiency, which is typically inversely proportional to the motor temperature. Therefore, the higher the temperature of the motor  170 , the smaller the amount of ground coffee that the grinder  174  is discharging through the port  176 . Consequently, the controller  64  can measure the amount of coffee discharged from the port  176  by monitoring the signals from the current and temperature sensors  178  and  180  and applying an algorithm that relates the values of these signals to the rate at which the grinder  174  discharges ground coffee through the port  176 . Alternatively, the grinding and measuring unit  60  may omit one or both of the current and temperature sensors  178  and  180 , and the controller  64  may measure the amount of ground coffee discharged from the port  176  by monitoring only the signal from the included one of the current and temperature sensors (if one is included). 
     When the controller  64  ( FIG. 3 ) determines that the grinder  174  has generated and discharged through the port  176  a predetermined amount of ground coffee, the controller deactivates the motor  170 . 
       FIG. 10  is a side view with portions broken away of a ground-coffee measuring assembly  190  of the grinding-and-measuring unit  60  of  FIG. 3  according to another embodiment of the invention, where like numbers reference components common to  FIGS. 9-10 . The assembly  190  can replace or supplement the controller&#39;s calculation of the amount of ground coffee discharged via the discharge port  176  based on the grind rate of the grinder  174  ( FIG. 9 ) and the signals from none, one, or both of the current and temperature sensors  178  and  180  of  FIG. 3 , and is disposed within the discharge port. Alternatively, the assembly  190  may be disposed in another suitable location within the grinding-and-measuring unit  60 . 
     The assembly  190  includes a motor  192 , a speed sensor  194 , a shaft  196 , and a disk  198  having an upper surface  200 . 
     The motor  192  is an electric or other suitable motor that is separate from the grinder motor  170  ( FIG. 9 ) and that spins the shaft  196  and the disk  198  at a substantially constant speed when the disk is able to rotate freely, i.e., when nothing, such as ground coffee, impedes the rotation of the disk. 
     The speed sensor  194  generates a signal that indicates the rotational speed of the disk  198 , and provides this signal to the controller  64  ( FIG. 3 ). 
     The disk  198  is substantially flat, relatively lightweight, and is formed from plastic or another suitable material. Furthermore, the disk  198  may have holes (not shown in  FIG. 10 ) sufficiently wide to pass coffee grounds. 
     In operation, the controller  64  ( FIG. 3 ) measures the amount of ground coffee (indicated by the arrows) discharged from the port  176  based on the rotational speed of the disk  198 . As ground coffee (indicated by the arrows) flows from the coffee grinder  174  ( FIG. 9 ) to the port  176 , the ground coffee collects on the upper surface  200  of the disk  198  before flowing over the sides (through the holes) of the disk and through the port as indicated by the arrows. Because the ground coffee collected on the surface  200  has a mass, it effectively changes the disk&#39;s rotational moment of inertia by an amount proportional to the mass of collected coffee. This change in the disk&#39;s moment of inertia changes the speed at which the disk  198  spins by an amount proportional to the change in the moment of inertia. The controller  64  monitors the speed of the disk  198  via the signal generated by the sensor  194 . Consequently, by integrating the speed of the disk  198  with respect to time, the controller  64  can use an algorithm that relates the integrated disk speed to the amount of ground coffee that collects on the disk surface  200  over time to determine the amount of ground coffee discharged from the port  176 . 
     Furthermore, the controller  64  ( FIG. 3 ) may use any of the above-described measuring techniques to “learn” a more accurate algorithm for determining the amount of ground coffee based on grind rate of the grinder  174  ( FIG. 9 ). That is, the controller can calculate the amount of ground coffee that the grinder  174  generates in two ways: 1) based on a predetermined grind rate multiplied by the “on” time of the grind motor  170  ( FIG. 9 ) and none, one, or both of the motor temperature and current draw as described above in conjunction with  FIG. 9 ; and, 2) using the disk  198 . Because the second calculation may be more accurate than the first, the controller  64  compares the results yielded by both calculations, and then adjusts the algorithm for the first calculation so that it yields a new result that is closer or equal to the result yielded by the second calculation. This “learning”, which the controller  64  may accomplish using known neural-network or other techniques, may allow the controller  64  to accurately measure the amount of discharged ground coffee if, e.g., the assembly  190  fails. 
     When the controller  64  ( FIG. 3 ) determines that the port  176  has discharged a predetermined amount of ground coffee, the controller deactivates the grinder motor  170  ( FIG. 3 ) and the motor  192 . 
       FIG. 11  is a side view with portions broken away of a ground-coffee measuring assembly  210  of the grinding-and-measuring unit  60  of  FIG. 3  according to another embodiment of the invention, where like numbers are used to reference components common to  FIGS. 9-11 . The assembly  210  can replace or supplement the controller&#39;s calculation of the amount of ground coffee discharged via the port  176  based on the grind rate of the grinder  174  ( FIG. 9 ) and the signals from none, one, or both of the current and temperature sensors  178  and  180  of  FIG. 9 ; and, like the assembly  190  of  FIG. 10 , the assembly  210  is disposed within the discharge port  176 . Alternatively, the assembly  210  may be disposed in another suitable location within the grinding-and-measuring unit  60 . 
     The assembly  210  includes an emitter  212  and a sensor  214 . The emitter  212  emits a beam  216  of electromagnetic energy such as light to the sensor  214 , which detects the intensity of the beam, generates a signal that indicates the intensity of the beam, and provides this signal to the controller  64  ( FIG. 3 ). For example, the emitter  212  may be a light-emitting diode (LED), or a laser diode, and the sensor  214  may be a photo detector. 
     In operation, the controller  64  ( FIG. 3 ) measures the amount of ground coffee discharged from the port  176  based on the intensity of the beam  216  detected by the sensor  214 . As ground coffee (indicated by the arrows) flows from the coffee grinder  174  ( FIG. 9 ) to the port  176 , at least some of the ground coffee passes through the beam  216 . The more ground coffee passing through the beam  216  at any instant, the smaller the portion of the beam that strikes the sensor  214 , and thus the lower the beam intensity detected by the sensor. The controller  64  monitors the intensity of the beam  216  via the signal generated by the sensor  214 . Consequently, by integrating the intensity of the beam  216  with respect to time, the controller  64  can use an algorithm that relates the integrated intensity to the amount of ground coffee that passes through the beam over time to determine the amount of ground coffee discharged from the port  176 . 
     Furthermore, the controller  64  may use the above-described measuring technique to “learn” a more accurate algorithm for determining the amount of ground coffee based on the grind rate of the grinder  174  ( FIG. 9 ) as described above in conjunction with  FIG. 10 . 
     When the controller  64  ( FIG. 3 ) determines that the port  176  has discharged a predetermined amount of ground coffee, the controller deactivates the grinding motor  170  ( FIG. 3 ). 
     Moreover, in another implementation of the assembly  210 , the emitter  212  is replaced with a combination emitter and detector, and the sensor  214  is replaced with a reflector. Therefore, the emitter/detector  212  emits the beam  216 , the reflector  214  reflects the beam, and the emitter/detector detects the intensity of the reflected beam. The controller  64  ( FIG. 3 ) measures the amount of ground coffee discharged through the port  176  based on the intensity of the reflected beam as described above. 
       FIG. 12  is a diagram of the beverage-brewing unit  50  and a ground-coffee measuring assembly  220  of the grinding and measuring unit  60  of  FIG. 3  according to another embodiment of the invention, where like numbers are used to reference components common to  FIGS. 9-12 . The assembly  220  can replace or supplement the controller&#39;s calculation of the amount of ground coffee discharged via the port  176  based on the grind rate of the grinder  174  ( FIG. 9 ) and the signals from none, one, or both of the current and temperature sensors  178  and  180  of  FIG. 9 , and is disposed external to the discharge port  176 . Alternatively, the assembly  220  may be disposed in another suitable location within the grinding-and-measuring unit  60 . Furthermore, although for purposes of explanation the assembly  220  is shown transporting ground coffee directly to the brewing chamber  80 , the assembly  220  transports the ground coffee to the ground-transporting unit  54  ( FIG. 3 ) where the brewing machine  30  ( FIG. 3 ) includes the ground-transporting unit. Alternatively, the assembly  220  may compose all or part of the ground-transporting unit  54 . 
     The assembly  220  includes a measuring, i.e., dosing, cup  222 , a scale  224 , and a cup drive assembly (the operation of which is indicated by the dashed line in  FIG. 12 ). The dosing cup  222  is kinematically decoupled from the cup drive assembly when the cup is on the scale  224 . “Kinematically decoupled” means that the drive assembly exerts no force on the cup  222 , so that the weight indicated by the scale  224  is not corrupted by the drive assembly. 
     The dosing cup  222  receives ground coffee (represented by the solid line arrow) discharged from the port  176 , and the scale  224  weighs the ground coffee and the cup and provides to the controller  64  ( FIG. 3 ) a signal that indicates this weight. Because the scale  224  may be sensitive to vibrations caused by the beverage-brewing machine  30  ( FIG. 3 ) or present in the environment in which the machine is located, the scale may weigh the ground coffee and cup multiple times, and the controller  64  may determine the weight of the ground coffee and cup to be the average of these multiple weights. For example, when the measured weight is close to the desired weight, the controller  64  may turn off the grinder motor  170  ( FIG. 9 ) to eliminate the vibrations therefrom, measure the weight of the cup  222  and coffee inside, and repeat this sequence until the desired amount of ground coffee is in the cup. 
     The cup drive assembly (represented by the dashed line) moves the cup  222  from the scale  224  to the opening  82  of the brewing chamber  80 , and tips the cup such that the ground coffee falls from the cup into the brewing chamber. The drive assembly may also “bang” the cup  222  to dislodge into the brewing chamber  80  ground coffee that is stuck to the bottom or sides of the cup. 
     In operation, the controller  64  ( FIG. 3 ) determines from the signal (or multiple signals per above) generated by the scale  224  the weight of ground coffee discharged from the port  176 . Ground coffee (indicated by the arrows) exits the port  176  and enters the cup  222 . The scale  224  weighs the cup  222  and the ground coffee in the cup, and, as discussed above, generates one or more signals that each represent the combined weight of the coffee and the cup. The controller  64  monitors the combined weight of the coffee and the cup via the one or more signals generated by the scale  224 . From the combined weight of the ground coffee and the cup  222 , the controller  64  determines the weight of the coffee by subtracting from the combined weight the known weight of the cup, which may be determined beforehand and stored in the memory  68  ( FIG. 3 ). To prevent overfilling of the cup  222 , the controller  64  may stop the grinder motor  170  ( FIG. 9 ) when the weight of the ground coffee in the cup is below the desired weight, and then weigh the coffee, pulse the motor, and repeat this sequence one or more times until the desired weight of ground coffee is in the cup. 
     When the controller  64  ( FIG. 3 ) determines that the port  176  has discharged a predetermined weight of ground coffee into the cup  222 , the controller deactivates the grinding motor  170  ( FIG. 9 ) and causes the cup drive assembly (represented by the dashed line) to dump the ground coffee in the cup  222  into the brewing chamber  180 . Then the controller  64  causes the cup  222  to return to its “home” position on the scale  224 . 
       FIGS. 13-18  illustrate the operation of the beverage-brewing machine  30  of  FIG. 3  during a beverage-brewing cycle according to an embodiment of the invention, where like numbers reference components common to  FIGS. 3-18 . For clarity of explanation,  FIGS. 13-18  omit some features discussed above in conjunction with  FIGS. 3-12 , it being understood that these features may be present even though they are not shown or discussed. For example, although  FIGS. 13-18  do not show the linkage members  126  and  128  and track guides  130 ,  132 ,  134 ,  135 , and  137 , ( FIGS. 5-7C ) of the shuttle assembly  98 , the shuttle assembly may include these linkage members and track guides. Furthermore, although it may not be explicitly stated, the controller  64  may control one or more of the below-described steps. Moreover, although the operation of the machine  30  is described for brewing coffee, the operation for brewing another beverage, such as tea, may be the same as or similar to the described operation. 
     Referring to FIGS.  3  and  13 - 18 , the operation of the beverage brewing machine  30  during a beverage-brewing cycle is discussed according to an embodiment of the invention. 
     Referring to  FIG. 13 , after a human operator (not shown in FIGS.  3  and  13 - 18 ) activates the machine  30  by, e.g., turning “on” a power switch (not shown in FIGS.  3  and  13 - 18 ), the machine  30  performs a self-check/initialization during which the piston  90  and shuttle assembly  98  move into respective “home” positions if they are not already in their respective home positions. For example, the piston  90  moves into a position where the piston surface  92  is substantially coplanar with the block surface  88 , and the shuttle assembly  98  moves into a position in which the opening  82  of the brew chamber  80  is partially or fully exposed. Alternatively, the piston  90  and shuttle assembly  98  may already be in their respective home positions from the last brew cycle, or may move into any other respective non-home positions that are suitable for starting the brew cycle. 
     Next, the operator enters a coffee selection (if multiple coffees are available), a beverage size (e.g., 8 ounces, 16 ounces), and one or more brewing parameters (e.g., grind size, ground-coffee-to-water ratio, water temperature, and brew time) via the control panel  70 . For example, if the hopper unit  58  holds two or more roasts of coffee beans, then the operator may select a desired roast by name or by another identifier, such as the name or number of the hopper (not shown in FIGS.  3  and  13 - 18 ) holding the beans of the desired roast. Furthermore, the machine  30  may allow the operator to enter a custom beverage size (e.g., 9 ounces, 11 ounces), or may constrain the operator to one or more predetermined sizes (e.g., 8 ounces, 16 ounces). Moreover, the operator may enter each brewing parameter separately, or may enter an identifier, such as the name of the selected roast, to select a set of predetermined brew parameters that are stored in the memory  68  and associated with the identifier. Alternatively, the present operator, another operator, or the machine  30  (via, e.g., the internet or RFID tag) may have already entered the brewing parameters when the coffee beans were loaded into the hopper. If the operator enters the brew parameters separately, but fails to enter one or more required parameters, then the machine  30  may assign a default value to each of the parameters not entered. And if the operator enters a set of brewing parameters via an identifier he may alter one or more of these pre-programmed parameters either directly or abstractly. An example of the later is where the operator selects an “abstract” brew strength (e.g., weak, normal, strong) that the controller  64  converts into an actual coffee-to-water ratio in a pre-programmed manner. In addition, the machine  30  may, via the display  70 , remind the operator to place a cup in the cup holder  44 . 
     Then, referring to  FIG. 14 , the piston  90  retracts a predetermined distance to leave enough room in the chamber  80  for receiving ground coffee  230 . Alternatively, if the home position of the piston  90  leaves sufficient room in the chamber  80 , then the piston need not retract. 
     Next, the grinding-and-measuring unit  60  and, if present, the grind-transporting unit  54 , load the brewing chamber  80  with a predetermined amount of the ground coffee  230 . If the grinding-and-measuring unit  60  can provide different grind sizes (e.g., coarse, fine), then the unit generates the ground coffee  230  having the selected grind size. Alternatively, the unit  60  may provide different portions of the ground coffee  230  having different grind sizes. For example, the unit  60  may provide an intermediate grind consistency by finely grinding the first half of the ground coffee  230  and coarsely grinding the second half of the ground coffee. Furthermore, because the grind size may affect the grind rate of the grinder  174  ( FIG. 9 ), the controller  64  may take into account the grind size when measuring the ground coffee  230 , particularly when using the (grind rate)×(grinding time) measuring technique described above in conjunction with  FIG. 9 . 
     Referring to  FIG. 15 , after the grinding-and-measuring unit  60 , and, if present, the grind-transporting unit  54 , load the ground coffee  230  into the chamber  80 , the shuttle assembly  98  seals the opening  82  of the brewing chamber  80  as described above in conjunction with  FIGS. 6A-6B . 
     While the grinding-and-measuring and grind-transporting units  60  and  54  are loading the ground coffee  230  into the chamber  80  and while the shuttle assembly  98  is sealing the chamber, the water-reservoir-and-heating unit  36  is heating the water to a predetermined temperature if the water is not already at this temperature. In one example, the unit  36  heats the water above the desired brewing temperature so that the water-temperature-control unit  38  can provide to the chamber  80  water at the desired brewing temperature by cooling the heated water from the reservoir with cold tap water as described above in conjunction with  FIG. 3 . In another example, the reservoir-and-heating unit  36  heats the water to the brewing temperature, and the temperature-control unit  38  is inactive or omitted. Either technique allows control of the brewing temperature from cup to cup. 
     Next, the water-measuring-and-transporting unit  40  fills the sealed brewing chamber  80  with a desired amount of water  232  having the desired brewing temperature via the nozzle  102 . In one example, the water-and-measuring unit  40  includes a pump that forces the desired amount of water  232  through the nozzle  102 . In another example, the water-measuring-and-transporting unit  40  lacks a pump, and the water  232  is gravity fed from the reservoir unit  36  to the nozzle  102  via the water-measuring-and-transporting unit. In these two techniques, the beverage-transporting unit  48  may open the outlet  108  to allow air in the chamber  80  to escape via the outlet as the water  232  enters the chamber. In yet another example, the outlet  108  is closed and the piston  90  retracts to create a suction that draws the water  232  from the reservoir  36  into the chamber  80  via the measuring-and-transporting unit  40  and the nozzle  102 . In still another example, a combination of the pump and piston suction is used to fill the chamber  80  with water. 
     Still referring to  FIG. 15 , techniques for measuring the water that the water-measuring-and-transporting unit  40  provides to the brewing chamber  80  are discussed. In one implementation, the unit  40  includes a solenoid pump, which pumps water at a highly consistent rate. Therefore, the controller  64  determines the amount of water that the unit  40  provides to the brewing chamber  80  as being equal to the product of the pump rate and the amount of time that the pump is active. Because the pump rate may vary with the pressure and temperature of the water from the temperature-control unit  38 , the temperature-control unit or the water-transporting unit  40  may include sensors to indicate the pressure and temperature of the water, and the controller  64  may take into account the pressure or temperature when measuring the amount of water  232  provided to the brewing chamber  80 . 
     And in an implementation where the piston  90  draws in the water  232  by retracting, then the controller  64  may measure the amount of water that enters the chamber  80  by measuring the distance that the piston  90  retracts, and using an algorithm to relate the distance retracted to the amount of water drawn. Because the amount of water that the piston  90  draws into the chamber  80  may depend on the temperature of the water and the temperature and pressure of the gas in the chamber and in other parts of the machine  30 , the machine may include temperature and pressure sensors in these parts of the machine, and the controller  64  may take into account these temperatures and pressures when measuring the amount of water  232  drawn into the chamber. 
     In still another example, the water  232  enters the chamber  80  or is measured using a combination or sub-combination of the above-described techniques. 
     In a related implementation, the controller  64  adjusts the amount of water  232  introduced to the chamber  80  based on the amount of ground coffee  230  introduced to the chamber. This maintains the coffee-to-water ratio, which is one of the brewing parameters that significantly affects taste, more accurate from cup to cup. The error in the ground-coffee-to-water ratio is the sum of the water-measurement error and the coffee-measurement error. To reduce the ratio error, the controller  64  can adjust the amount of one of the ground coffee  230  and water  232  based on the measurement of the other. Because the water measurement is typically more accurate than the coffee measurement, the controller  64  adjusts the amount of water based on the measured amount of ground coffee  230  in the chamber  80 . For example, assume that the coffee-to-water ratio is 3 grams/ounce, so a 10-ounce cup of coffee calls for 30 grams of ground coffee and 10 ounces of water. However, suppose that the controller  64  determines that 33 grams of coffee were introduced into the chamber  80 . To maintain the 3/1 ratio, the controller  64  causes the water-measuring- and transportation unit  40  to introduce 11 ounces of water into the cylinder. The machine  30  can then discard one ounce of the brewed coffee via the liquid-waste disposal unit  42  as further described below in conjunction with the discussion of “silt” so that only the desired 10 ounces of coffee fill the operator&#39;s coffee cup (not shown in FIGS.  3  and  13 - 18 ). Although the coffee-to-water ratio may still be off due to errors in measuring the coffee  230  and water  232 , the ratio is typically more accurate than it would have been had the amount of water not been adjusted as described above. The controller  64  may use this technique when too little coffee  230  is in the chamber  80  by introducing less water into the chamber, although this will result in less than the selected amount of coffee in the operator&#39;s cup. Alternatively, the controller  64  may cause the grinder  174  ( FIG. 9 ) to grind some additional coffee. 
     Still referring to  FIG. 15 , after the desired amounts of ground coffee  230  and water  232  are in the chamber  80 , the machine  30  agitates the mixture of the ground coffee and the water to thoroughly wet the ground coffee. In one example, the spray pattern from the nozzle  102  performs this agitation while the water  232  is entering the chamber  80 . To enhance the agitation, the water  232  may enter the chamber  80  in multiple bursts. In another example, a mechanical member (not shown in FIGS.  3  and  13 - 17 ) performs the agitation while the water  232  is entering the chamber  80 , after the water enters the chamber, or both while and after the water enters the chamber. In yet another example, both the nozzle  102  and the mechanical member perform the agitation. 
     Next, the mixture of the ground coffee  230  and the water  232  remains in the chamber  80  for the selected brewing time. During the brewing time, the brewing unit  50  may heat or cool the mixture within the chamber  80  as discussed above in conjunction with  FIG. 4 . 
     Then, the cup sensing unit  52  indicates whether a cup (not shown in FIGS.  3  and  13 - 18 ) is in the holder  44 . If a cup is not in the holder, then the controller  64  halts the brewing cycle, and may sound an audio or visual alarm, until the operator places a cup in the holder  44 . If a cup is in the holder  44 , then the brewing cycle continues as described below. 
     Referring to  FIG. 16 , after the brewing time has expired, the piston  90  extends to expel the brewed coffee  234  from the chamber  80  and into a coffee cup (not shown in FIGS.  3  and  13 - 18 ) in the cup holder  44  via the beverage-transporting and -dispensing units  48  and  46 . The piston  90  forces the brewed coffee  234  through the filter  106 , into the space  112 , and through the outlet  108  to the beverage transporting unit  48 . In one implementation, the piston  90  extends in multiple steps to allow the spent coffee grounds  230  to settle on the surface  92  of the piston. In another implementation, a pressure sensor (not shown in FIGS.  3  and  13 - 18 ) is located within the brewing chamber  80 , and the controller  64  controls the extension speed of the piston  90  in a closed-loop manner to maintain the pressure within the brewing chamber  80  at a desired level that prevents damage to, e.g., the filter  106  and the seal between the shuttle assembly  98  and the brewing chamber. 
     Still referring to  FIG. 16 , sometimes “silt” or other undesirable debris (not shown in FIGS.  3  and  13 - 18 ) that are too fine to be retained in the brewing chamber  80  by the filter  106  float near or to the top of the brewed coffee  234 . To keep this debris out of the coffee cup (not shown in FIGS.  3  and  13 - 18 ), before the piston  90  begins to extend the beverage-transporting unit  48  closes and the water-transporting unit  40  opens. Therefore, as the piston  90  extends, a predetermined amount of the brewed coffee  234  including the debris is expelled into the liquid-disposal unit  42 . After the piston  90  expels the predetermined amount of brewed coffee  234  into the disposal unit  42 , the beverage-transporting unit  48  opens and the water-transporting unit  40  closes such that the extending piston expels the remaining, and substantially debris free, brewed coffee  234  to the beverage-dispensing unit  46 . The controller  64  may cause the piston  90  to expel the desired amount of brewed coffee  234  into the disposal unit  42  by measuring the distance that the piston extends, and using an algorithm to determine the amount of brewed coffee expelled based on the distance that the piston extends (this algorithm may be the same as or similar to the one used to determine the amount of water drawn into the chamber  80  by the retracting piston  90  as described above). Furthermore, the controller  64  may introduce additional ground coffee  230  and water  232  into the chamber  80  to compensate for the debris-removal step. For example, if the operator wants an 8 ounce cup of coffee brewed with 24 grams of ground coffee (a 3 gram to 1 ounce ratio), then the controller  64  may introduce 27 grams of ground coffee  230  and 9 ounces of water  232  into the chamber  80 . This maintains the desired coffee-to-water ratio and cup size while allowing the piston  90  to expel 1 ounce of debris-ridden brewed coffee  234  into the liquid-waste disposal unit  42 . 
     Referring to  FIG. 17 , the piston  90  stops extending and expelling the brewed coffee  234  (not shown in  FIG. 17 ) when the piston surface  92  is a predetermined distance below the block surface  88 . This predetermined distance is sufficient to prevent the spent coffee grounds  234  from pressing against the filter  106  with a force sufficient to damage the filter, the seal between the chamber  80  and the shuttle assembly  98 , or other components of the shuttle assembly. 
     Then, the controller  64  may indicate to the operator via the display  70  or other indicator (not shown in FIGS.  3  and  13 - 18 ) that he may remove the coffee-filled cup (not shown in FIGS.  3  and  13 - 18 ) from the cup holder  44 . 
     Referring to  FIG. 18 , the shuttle assembly  98  next moves upward and away from the chamber  80 , and the piston  90  extends until the piston surface  92  is substantially coplanar with the block surface  88 . 
     Next, the shuttle assembly  98  moves rightward such that the wiper  110  sweeps the spent coffee grounds  230  from the piston  90  and into the solid waste disposal unit  56 . 
     Still referring to FIGS.  3  and  13 - 18 , other embodiments of the above-described brewing cycle are contemplated. For example, the order of the above-described steps may be altered, the steps described as being performed concurrently may be performed at different times, and steps described as being performed at different times may be performed concurrently. Furthermore, some of the steps may be omitted. 
     Referring to  FIGS. 3 and 16 , the operation of the beverage-brewing machine  30  during a cleaning cycle is described according to an embodiment of the invention. Although not specifically discussed, some or all of the techniques discussed above in conjunction with the brewing cycle of  FIGS. 13-18  may perform or be modified to perform the same or similar functions during the cleaning cycle. 
     After an operator (not shown in  FIGS. 3 and 16 ) activates the machine  30  by, e.g., turning “on” a power switch (not shown in  FIGS. 3 and 16 ), he may initiate a cleaning cycle via the control panel  70 , or the machine may initiate the cleaning cycle automatically. For example, the machine  30  may automatically initiate the cleaning cycle at a predetermined time each day. 
     Next, the shuttle assembly  98  seals the brewing chamber  80 . 
     While the shuttle assembly  98  is sealing the chamber  80 , the water reservoir and heating unit  36  heats the water to a predetermined temperature if the water is not already at this temperature. In one example, the unit  36  heats the water above the desired cleaning temperature so that the water temperature control unit  38  can provide to the chamber  80  water at the desired cleaning temperature by cooling the heated water with cold tap water. In another example, the reservoir-and-heating unit  36  heats the water to the cleaning temperature, and the temperature-control unit  38  is inactive or omitted. 
     Then, the water-and-cleaner-measuring-and-transporting unit  40  fills the sealed brewing chamber  80  via the nozzle  102  with a mixture comprising a predetermined amount of water and cleaning solution (e.g., vinegar) from the cleaner dispensing unit  34 . The unit  40  may measure the mixture using the same techniques and components used to measure the water during a brewing cycle as discussed above in conjunction with  FIGS. 13-18 . For example, the cleaning dispenser  34  may provide a steady flow of cleaning solution to the transporting unit  40 , which provides a predetermined amount of water to the chamber  80 . Because the unit  34  dispenses the cleaning solution at a known rate, the amount of cleaning solution dispensed is proportional to the amount of water that the transporting unit  40  provides to the chamber  80 . Furthermore, while the cleaning mixture enters the chamber  80 , the beverage-transporting unit  48  may open the outlet  108  to allow air in the chamber to escape. In another implementation, the outlet  108  is closed and the piston  90  retracts to creating a suction that draws the mixture of water and cleaning solution into the chamber  80  via the measuring-and-transporting unit  40  and the nozzle  102 . With this technique, the controller  64  can measure the amount of cleaning mixture that enters the chamber  80  using the same techniques to measure drawn-in water as discussed above in conjunction with  FIGS. 13-18 . In yet another implementation, the water-and-cleaner mixture enters the chamber  80  using a combination or sub-combination of the above-described techniques. In still another implementation, the operator may pour the cleaning solution into the chamber  80  via the chamber opening  82 . 
     Next, the machine  30  agitates the mixture of the cleaning solution and water. In one implementation, the spray pattern from the nozzle  102  performs this agitation while the mixture is entering the chamber  80 . To enhance the agitation and cleaning of the chamber  80 , the mixture may enter the chamber in multiple bursts. In another example, a mechanical member (not shown in  FIGS. 3 and 16 ) performs the agitation while the mixture is entering the chamber  80 , after the mixture enters the chamber, or both while and after the mixture enters the chamber. In yet another example, both the nozzle  102  and the mechanical member agitate the cleaning mixture. 
     Then, the cleaning mixture remains in the chamber  80  for a predetermined cleaning time, during which the piston  90  may move up or down to enhance the cleaning of the chamber  80  and the piston. 
     After the cleaning time has expired, the cup sensing unit  52  indicates to the controller  64  whether a cup is in the cup holder  44 . If a cup is present, then the controller  64  halts the cleaning cycle and may sound an audible or visible alarm until the cup is removed from the holder. 
     If the cup sensing unit  52  indicates that no cup is in the cup holder  44 , the piston  90  extends to expel the cleaning mixture from the chamber  80  and into the drain unit  44  via the beverage-transporting-and-dispensing units  48  and  46 . The piston  90  forces the cleaning mixture through the filter  106 , into the space  112 , and through the outlet  108  to the beverage-transporting unit  48 . The cleaning mixture cleans the filter  106 , the space  112 , the outlet  106 , the beverage-transporting-and-dispensing units  48  and  46 , the cup-holder-and-drain unit  44 , and the conduits connecting these components as the mixture passes through. 
     The piston  90  stops extending and expelling the cleaning mixture when the piston surface  92  is substantially coplanar with the block surface  88 . 
     Next, the machine  30  repeats the above-described cycle one or more times with water only to rinse the cleaned components and conduits. 
     Then, the shuttle assembly  98  disengages the chamber  80  in preparation of the next brewing cycle. 
     Still referring to  FIGS. 3 and 16 , other embodiments of the cleaning cycle are contemplated. For example, instead of mixing cleaning solution with water, the cleaner-measuring unit  40  may provide straight (i.e., unmixed with water) cleaning solution from the dispenser  34  to the brewing chamber  80 . Furthermore, the order of the above-described steps may be altered, the steps described as being performed concurrently may be performed at different times, and steps described as being performed at different times may be performed concurrently. Moreover, some of the steps may be omitted. 
       FIG. 19  is a perspective view of the machine  30  according to an embodiment of the invention. 
     Referring to  FIGS. 3 and 19 , in addition to the cup-holder-and-drain unit  44  and the control panel and display  70 , the machine  30  includes a stainless steel and plastic housing  240 , hoppers  242  and  244 , a beverage dispensing spout  246 , a tray  248 , and three doors or panels  250 ,  252 , and  254 . Each of the hoppers  242  and  244 , which are part of the hopper unit  58 , can hold the same or different types of coffee beans. The dispensing spout  246  is part of the beverage-dispensing unit  48 , and the tray  248 , which is removable for cleaning, is part of the cup-holder-and-drain unit  44 . The door/panel  250  allows access for emptying or servicing the solid-waste-disposal unit  56 , and the door/panel  252  allows access for servicing some or all of the components above the barrier  62  in  FIG. 3 . The door/panel  254  allows access for servicing the printed circuit board (not shown in  FIGS. 3 and 19 ) on which the processor  66 , memory  68 , communications port  72 , and perhaps other electronic components are located. The height of the machine  30  is 18 inches or less so that the machine can fit on a counter top under standard-height cabinets (neither shown in  FIG. 19 ). Because this height may be too small to allow water from the reservoir unit  36  to gravity feed into the brewing chamber  80  (not shown in  FIGS. 3 and 19 ), the water-transporting unit  40  may include a pump, or the piston  90  may retract to draw water into the brewing chamber as described above in conjunction with  FIGS. 13-18 . 
     From the foregoing it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Furthermore, where an alternative is disclosed for a particular embodiment, this alternative may also apply to other embodiments even if not specifically stated.