US20090095165A1 - Machine for brewing a beverage such as coffee and related method - Google Patents

Abstract

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 the beverage to brew, and to move to a second position to dispense the beverage by forcing the beverage out of the chamber. By modifying some or all steps of the French press brewing technique, the machine can typically control coffee-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.

Description

CLAIM OF PRIORITY
• This application claims priority to U.S. Provisional Application Ser. Nos. 60/670,955 filed on Apr. 11, 2005, 60/719,069 filed on Sep. 20, 2005, and Ser. No. ______ (attorney docket number 2402-001-05 titled IMPROVED MAGNOLIA AND PHINNEY BREWER) filed on Apr. 6, 2006. All of the above applications are incorporated by reference.
BACKGROUND
• 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 toFIGS. 1 and 2, the French press technique is described.
• Referring toFIG. 1, one places groundcoffee10 andhot water12 in acoffee pot14, and allows coffee to brew. Because theground coffee10 often floats to the surface of thewater12, 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 toFIG. 2, after thecoffee15 has brewed, one grasps ahandle16 of afilter18, inserts the filter into thecoffee pot14, and presses the filter down toward the bottom of the pot.
• Because thefilter18 passes liquid but does not pass coffee-ground-sized particles, as one presses the filter toward the bottom of thecoffee pot14, the substantially ground-free brewedcoffee15 fills the portion of the pot above the filter while the filter retains theground coffee10 in the portion of the pot below the filter. Of course theedge20 of thefilter18 and theinner side22 of thepot14 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 thefilter18 below aspout24 of thecoffee pot14, he can pour the substantially ground-free brewedcoffee15 into a cup (not shown inFIGS. 1 and 2) via the spout. Although ideally one may stop pressing thefilter18 after the filter is below thespout24, one typically presses the filter all the way to the bottom of thecoffee pot14 to reduce the chances of undersized coffee grounds passing through the filter and into the cup.
• Still referring toFIG. 2, after one pours the desired amount of brewedcoffee15, he retracts thefilter18 from thepot14 by pulling on thehandle16, removes theground coffee10 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 inFIGS. 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
• 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 ofFIG. 3 according to an embodiment of the invention.
• FIG. 5 is an exploded isometric view of the filter and wiper shuttle assembly ofFIG. 4 according to an embodiment of the invention.
• FIGS. 6A-6B are side views of the filter and wiper shuttle assembly ofFIGS. 4-5 according to an embodiment of the invention.
• FIGS. 7A-7C are side views of the filter and wiper shuttle assembly ofFIGS. 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 ofFIGS. 7A-7C according to an embodiment of the invention.
• FIG. 9 is a block diagram of the grinding-and-measuring unit ofFIG. 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 ofFIG. 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 ofFIG. 9 according to yet another embodiment of the invention.
• FIG. 12 is a block diagram of the brewing chamber ofFIG. 4 and the measuring assembly of the grinding-and-measuring unit ofFIG. 9 according to still another embodiment of the invention.
• FIGS. 13-18 illustrate a brewing cycle of the beverage-brewing machine ofFIG. 3 according to an embodiment of the invention.
• FIG. 19 is a perspective view of the beverage-brewing machine ofFIG. 3 according to an embodiment of the invention.
DETAILED DESCRIPTION
• 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 amachine30 for brewing a beverage according to an embodiment of the invention. The beverage-brewing machine30 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 withFIGS. 1-2. Consequently, themachine30 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.
• Themachine30 includes the following components: awater filter32, cleaner-dispensing unit34, water-reservoir-and-heating unit36, water-temperature-control unit38, water-and-cleaner-measuring-and-transporting unit40, liquid-waste-disposal unit42, cup-holder-and-overflow/waste-drain unit44, beverage-dispensing unit46, beverage-transporting unit48, beverage-brewing unit50, cup-sensing unit52, grind-transporting unit54, solid-waste-disposal unit56,hopper unit58, grinding-and-measuring unit60,barrier62, andcontroller64. And although themachine30 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.
• Thewater filter32 filters the water that is used to brew the coffee. But one may omit thefilter32 from the beverage-brewing machine30, particularly where the machine is installed in an establishment that has a water-purification system separate from the machine.
• The cleaner-dispensingunit34 stores a cleaning solution that the beverage-brewing machine30 may use to clean some of the above-described components during a cleaning cycle, which is described in more detail below in conjunction withFIG. 16. Suitable cleaning solutions include vinegar, ammonia, soap-based solutions, and mixtures thereof.
• The water-reservoir-and-heating unit36 receives and stores water from thewater filter32, and, under the control of thecontroller64, 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 inFIG. 3) indicates to thecontroller64 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 themachine30 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 unit36 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 unit38 can alter the temperature of the water from thereservoir unit36 to allow a different brew temperature from cup to cup. The temperature-control unit38 receives water from thereservoir36 during a beverage-brewing cycle, and, in response to thecontroller64, adjusts the temperature of the water received from the reservoir. In one implementation, the temperature-control unit38 mixes the heated water from thereservoir36 with colder water from thefilter32 to lower the temperature of the water used to brew coffee from the temperature of the water in the reservoir. The temperature-control unit38 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, thetemperature control unit38 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 thefilter32 with the heated water, the temperature-control unit38 may include a heat exchanger that allows the cold water to cool the heated water without actually mixing with the heated water. Thetemperature control unit38 may also be able to heat the water used to brew the coffee above the temperature of the water in thereservoir36.
• Alternatively, one may omit the water-temperature-control unit38 from themachine30, and depend on the reservoir-and-heating unit36 to heat the water to the desired temperature. An advantage of the temperature-control unit38 is that it provides water at the desired brew temperature relatively quickly if the water in thereservoir36 is at or higher than the desired brew temperature; a disadvantage is that theunit38 may add complexity and expense to themachine30. Comparatively, although omitting the temperature-control unit38 may slow the machine's brewing speed, the reservoir-and-heating unit36 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 controller64) without adding any expense or complexity to the machine. Typically, the cold tap water entering thereservoir36 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-transportingunit40 transports a predetermined amount of water from the temperature-control unit38 to thebrewing unit50 during a brewing cycle, and transports a predetermined amount of cleaning solution to the brewing unit during a cleaning cycle. The measuring-and-transportingunit40 may also direct liquid waste from thebrewing unit50 to the liquid-waste disposal unit42 as discussed below in conjunction withFIGS. 13-18. Theunit40 includes one or more electronically controllable valves, which, in response to thecontroller64, direct the water, cleaning solution, and liquid waste as described above and as described below in conjunction withFIGS. 13-18. Furthermore, theunit40 measures the water and cleaning solution transported to thebrewing chamber50 as described below in conjunction withFIGS. 13-18. Moreover, theunit40 may provide hot water directly to thebeverage dispensing unit46 so that one can obtain hot water for any desired use.
• The liquid-waste disposal unit42 receives liquid waste from the measuring-and-transportingunit40 and disposes of this waste. Thedisposal unit42 may include a drain (not shown inFIG. 3) that is connected to the sewer line (not shown inFIG. 3) of the establishment in which themachine30 is installed. Alternatively, thedisposal unit42 may receive liquid waste from thebeverage transporting unit48 or from another component of themachine30.
• The cup-holder-and-overflow/waste-drain unit44 holds a cup (not shown inFIG. 3) while the beverage-dispenser unit46 fills the cup with the brewed beverage (or hot water as described above). Theunit44 also includes a drain portion to absorb, e.g., spillage from the cup and drippings from thedispenser unit46 after the cup has been removed. The drain portion of theunit44 may be removable for emptying, or may be connected to the liquid-waste disposal unit42 or directly to the sewer line of the establishment in which themachine30 is installed.
• The beverage-dispensingunit46 includes a spout (not shown inFIG. 3), and dispenses the brewed beverage into the cup (not shown inFIG. 3) as discussed in the preceding paragraph.
• The beverage-transportingunit48 transports the brewed beverage from thebrewing unit50 to the dispensingunit46. Theunit48 may include an electronically controllable valve (not shown inFIG. 3), which, in response to thecontroller64, opens after thebrewing unit50 has brewed the beverage to allow the beverage to flow to the dispensingunit46. To prevent thedispensing unit46 from dispensing a beverage when no cup is present, thecontroller64 may close the valve if thecup sensor52 indicates that no cup is present in the cup-holder portion of theunit44. Thecontroller64 may also close the valve at other times as described below in conjunction withFIGS. 13-18.
• The beverage-brewing unit50 receives heated water from the measuring-and-transportingunit40, receives ground coffee from the grind-transportingunit54, brews coffee, and then provides the brewed coffee to the beverage-dispensingunit46 via the beverage-transportingunit48. Thebrewing unit50 is further described below in conjunction withFIGS. 4-8 and13-18.
• As discussed above, the cup-sensingunit52 indicates to thecontroller64 whether a cup (not shown inFIG. 3) is present in thecup holder44. If the cup is not present after thebrewing unit50 has brewed coffee, then thecontroller64 may deactivate the beverage-transportingunit48 to prevent the beverage-dispensingunit46 from dispensing brewed coffee directly into the drain portion of thedrain unit44. Alternatively, if the cup is present during a cleaning cycle, then thecontroller64 may deactivate the beverage-transportingunit48 to prevent cleaning solution from entering the cup. The cup-sensingunit52 may include any type of sensor, such as an optical, mechanical, or ultrasonic sensor.
• The grind-transportingunit54 may include one or more electronically controllable valves, which, in response to thecontroller64, route ground coffee from the grinding-and-measuringunit60 to either thebrewing unit50 or to the solid-waste-disposal unit56. Thecontroller64 may cause theunit54 to route ground coffee to thedisposal unit56 when one wishes to “grind through” the remaining coffee beans in a hopper (not shown inFIG. 3) of thehopper unit58 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 unit56 receives “ground through” coffee from the grind-transportingunit54 per the preceding paragraph, and receives spent coffee grounds and disposable filters (if used) from thebrewing unit50 as discussed below. Thedisposal unit56 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 themachine30 is installed. In addition, the solid-waste-disposal unit56 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. Thedisposal unit56 may periodically commence an automatic flushing sequence, e.g., after brewing each cup of coffee. Or, one may commence the flushing sequence manually.
• Thehopper unit58 includes one or more hoppers for holding coffee beans (neither shown inFIG. 3), which are gravity fed to the grinding-and-measuringunit60. Where thehopper unit58 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 thecontroller64, the grinding-and-measuringunit60 grinds coffee beans (not shown inFIG. 3) from thehopper unit50, and then provides to the grind-transporting unit54 a predetermined amount of ground coffee. In one implementation, the grinding-and-measuringunit60 continually indicates to thecontroller64 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 thecontroller64 deactivates theunit60. Techniques for indicating the rate at which theunit60 generates ground coffee and other techniques for measuring the ground coffee are discussed below in conjunction withFIGS. 9-12. Furthermore, theunit60 may allow one to select, via thecontroller64, 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.
• Thebarrier62 separates thecontroller64 and associated circuitry (not shown inFIG. 3) from other components of themachine30. For example, steam from hot water and brewing or brewed coffee may condense and damage or otherwise render inoperable thecontroller64. Furthermore, condensation on the conduits that carry cold tap water may cause similar problems. Therefore, amoisture barrier62 helps keep thecontroller64 and associated circuitry dry.
• Thecontroller64 controls the operation of some or all of the other components of thebrewing machine30 as discussed above, and includes aprocessor66, amemory68, a control panel anddisplay70, and acommunications port72.
• Theprocessor66 executes a software program stored in thememory68 or in another memory (not shown), and controls the operations of the components of themachine30 as described above and as described below.
• In addition to storing one or more software programs, thememory68 may store sets of predetermined brew parameters as discussed below in conjunction withFIGS. 13-18, and may provide working memory for theprocessor66.
• The control panel anddisplay70 allows an operator (not shown inFIG. 3) to enter brewing options (e.g., coffee type, cup size, and brewing parameters) or to select brewing options from a menu that theprocessor66 may generate on the display. For example, the operator may select via the control panel and display66 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 thememory68. 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 thememory68 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 thecontroller64 causes themachine30 to brew coffee according to the set of parameters corresponding to the identifier.
• Thecommunications port72 allows theprocessor66,memory68, and control panel anddisplay70 to communicate with one or more devices external to themachine30. For example, theport72 may be connected to a computer (not shown inFIG. 3) so that one can program or run diagnostics from the computer. Or, theport72 may be connected to the internet, so that one can download into thememory68 data such as sets of brewing parameters from coffee roasters or suppliers. In addition, theport72 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's preferred coffee type, cup size, or brew parameters). Furthermore, theport72 may allow theprocessor66 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 themachine30.
• Still referring toFIG. 3, alternate embodiments of themachine30 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 unit50 ofFIG. 3 according to an embodiment of the invention. As discussed above in conjunction withFIG. 3, thebrewing unit50 allows themachine30 to brew coffee according to a modified French press technique.
• The beverage-brewing unit50 includes abrewing chamber80 having atop opening82 and aside wall84 and disposed in achamber block86 having atop surface88, apiston90 disposed within the chamber and having atop surface92 andside94, amotor96 for driving the piston, and a filter andwiper shuttle assembly98. Theshuttle assembly98 is illustrated in a disengaged position in which it is not sealing theopening82. In a closed position (not illustrated inFIG. 4), theshuttle assembly98 covers and seals theopening82 while coffee brews in thechamber80.
• Thebrewing chamber80, which may be cylindrical, holds the ground coffee and water (neither shown inFIG. 4) while the coffee brews. One may design the shape and other features of thechamber80 to promote agitation of the water-and-ground-coffee mixture as discussed below.
• Thepiston90 is the same shape as thebrewing chamber80, theside94 of the piston forms a water-tight seal withside wall84 of the brewing chamber, and themotor96 moves the piston up and down within the chamber. Themotor96, which is responsive to the controller64 (FIG. 3), may be any motor, such as a stepper motor, suitable to drive thepiston90, 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.
• Theshuttle assembly98 includes aninlet100, anozzle102,separator ribs104, afilter106, anoutlet108, and awiper110. A shuttle-assembly driver (not shown inFIG. 4 but described below in conjunction withFIGS. 7A-7C) moves theshuttle assembly98 across thechamber opening82, and causes the shuttle assembly to seal the chamber opening while coffee is brewing in thechamber80.
• Theinlet100 is a conduit that routes hot water or cleaning solution from the water-measuring-and-transporting unit40 (FIG. 3) to thenozzle102.
• Thenozzle102 directs the water from theinlet100 in a spray pattern to agitate the mixture of the water and the ground coffee (not shown inFIG. 4) within thechamber80 so that the coffee grounds are more thoroughly wetted. For example, thenozzle102 may create a pattern that causes the mixture of water and coffee grounds within thechamber80 to swirl around as if one were stirring the mixture. Moreover, the water-measuring-and-transporting unit40 (FIG. 3) may include a pump or other device that can, in response to the controller64 (FIG. 3), impart a predetermined pressure to the water in theinlet100 to increase the agitation of the water-and-coffee-ground mixture. Thenozzle102 may also hold thefilter106 in place as discussed below in conjunction withFIG. 5. Furthermore, thenozzle102 may be positioned such that it is in the center of thechamber opening82 when the shuttle assembly covers thebrewing chamber80, or may be positioned in any non-centered location. Moreover, thenozzle102 may cause the water to enter the chamber at an angle to promote agitation of the water-and-coffee-ground mixture as discussed above.
• Theseparator ribs104 create aspace112 between thefilter106 and abottom surface114 of theshuttle assembly98 to facilitate the flow of brewed coffee from thechamber80 to theoutlet108. Theribs104 may be attached to or integral with either thefilter106 or thebottom surface114.
• Thefilter106 effectively separates spent coffee grounds from brewed coffee. After the coffee brews in thechamber80, themotor96 extends thepiston90 upward at a controlled speed to force the brewed coffee through thefilter106, into thespace112, and to the beverage-transporting unit48 (FIG. 3) via theoutlet108. Although thefilter106 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, thefilter106 retains the coffee grounds in thechamber80 so that the grounds do not contaminate the dispensed brewed coffee.
• Thewiper110 transports the spent coffee grounds from thebrewing unit50 into the solid-waste disposal unit56 (FIG. 3). Specifically, after thepiston90 extends to force the brewed coffee out of thechamber80 as discussed in the preceding paragraph, the controller64 (FIG. 3) causes the shuttle-assembly driver (not shown inFIG. 4) to raise the shuttle assembly98 a predetermined distance so that the bottom edge of thewiper110 is substantially even with thesurface88 of thechamber block86. Next, thecontroller64 causes themotor96 to further extend thepiston90 until thesurface92 of the piston is substantially coplanar with thesurface88. Then, thecontroller64 causes the shuttle-assembly driver to move theshuttle assembly98 in a direction (here to the right ofFIG. 4) that is substantially perpendicular to the direction in which thepiston90 moves such that thewiper110 sweeps the spent coffee grounds from thepiston surface92, onto thesurface88, and into the solid-waste-disposal unit56 (FIG. 3). As discussed below in conjunction withFIGS. 7A-7C, thebrewing unit50 may also include a cleaning assembly for cleaning thewiper110 and thefilter106.
• To provide a more precise control of the brewing temperature, thebrewing unit50 may include a temperature sensor and a heating/cooling mechanism (neither shown inFIG. 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 theside wall84 of thechamber80, or on the outside of thechamber block86. To heat the water-and-ground-coffee mixture with thechamber80, the machine30 (FIG. 3) fills the jacket with hot water from the reservoir36 (FIG. 3) or from another source; similarly, to cool the mixture themachine30 fills the jacket with cold water from thefilter32 or directly from the tap. Using the temperature sensor, thecontroller64 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 theshuttle assembly98 ofFIG. 4 according to an embodiment of the invention where thebrewing chamber80 ofFIG. 4 is cylindrical.
• Thefilter106 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. Thefilter106 andspace112 are the same shape as thechamber opening82. Furthermore, thefilter106 may be flat, or may be slightly concave with an inner curvature facing thechamber80.
• The separatingribs104 are arranged to form a manifold. That is, theribs104 are arranged so that they direct brewed coffee flowing from thechamber80 through thefilter106 into theoutlet108.
• Theinlet100 andnozzle102 are threaded so that one can screw the nozzle into the inlet; and, as discussed above in conjunction withFIG. 4, the nozzle secures thefilter106 when the nozzle is screwed into the inlet.
• In addition to theinlet100, thenozzle102, theribs104, thefilter106, theoutlet108, and thewiper110, theshuttle assembly98 includes agasket120, upper andlower portions122 and124,linkage members126 and128, which connect the upper and lower portions, and track guides130,132,134,135, and137 (the counterparts to theguides134,135, and137 are not present inFIG. 5).
• Referring toFIGS. 4 and 5, thegasket120 forms a water-tight face seal around the perimeter of the chamber opening82 while the water-measuring-and-transportingunit40 introduces water into thebrew chamber80, while the coffee brews, and while the piston90 (FIG. 4) extends to dispense the brewed coffee. Alternatively, theshuttle assembly98 may be designed to make a bore seal with thechamber opening82.
• The upper andlower portions122 and124, thelinkage members126 and128, and the track guides130,132,134,135, and137 are further described below in conjunction withFIGS. 6A and 6B.
• FIG. 6A is a cut-away side view of thebrewing unit50 and theshuttle assembly98 disengaged from the brewing unit according to an embodiment of the invention. While disengaged, thelower portion122 of theshuttle assembly98 is raised substantially the thickness of thewiper110 above thesurface88 of thechamber block86 such that the gasket120 (FIG. 5) is spaced from the surface of the chamber block, and thus does not seal thechamber opening82. Consequently, thewiper110 can sweep the spent coffee grounds (not shown inFIG. 6A) off of thepiston90 as discussed above in conjunction withFIG. 4. The upper trackguides including guides130,132, and134 (FIG. 5) engage anupper track136, and the lower trackguides including guides135 and137 engage alower track138. The upper andlower tracks136 and138 are part of a shuttle-assembly drive, which is further described below in conjunction withFIGS. 7A-7C. The upper guides130, and132, and134 allow theupper portion122 of theshuttle assembly98 to move back and forth along theupper track136, and thelower guides135 and137 allow thelower portion124 of the shuttle assembly to move back and forth along thelower track138. Furthermore, while theshuttle assembly98 is disengaged from thebrewing unit50, thelinkage members126 and128 make an acute angle relative to theupper track136.
• FIG. 6B is a cut-away side view of thebrewing unit50 and theshuttle assembly98 engaged with thebrewing unit50 according to an embodiment of the invention. In this position, the lower track guides including theguides135 and137 engagevertical portions140 and142 of thelower track138, and force thelower portion122 of theshuttle assembly98 against thesurface88 of thechamber block86 such that the gasket120 (FIG. 5) seals thechamber opening82.
• Referring toFIGS. 6A and 6B, the operation of theshuttle assembly98 is described according to an embodiment of the invention.
• After the grind-transporting unit54 (FIG. 3) loads ground coffee into thechamber80 via theopening82, theshuttle assembly98 moves leftward from its position inFIG. 6A.
• When the lower track guides135,137, etc. respectively engage thevertical portions140 and142, the linkage members straighten, and thus force thelower portion122 of theshuttle assembly98 toward and against thesurface88 such that the gasket120 (FIG. 5) seals thebrewing chamber80.
• After the coffee brews, the piston90 (FIG. 4) extends to dispense the brewed coffee from thechamber80. Because thetracks136 and138 compose an over-the-center-toggle configuration, the pressure generated against thelower portion22 by thepiston90 forces theshuttle assembly98 to the left. But because theshuttle assembly98 can travel little or no distance to the left, the shuttle assembly remains in the engaged position ofFIG. 6B. Therefore, thetracks136 and138 implement a stable seal, because even in the absence of force on theshuttle assembly98 in the leftward direction, pressure within thechamber80 will reinforce the seal, and will not cause the seal to “blow” by forcing theshuttle assembly98 rightward.
• After thepiston90 dispenses the brewed coffee, theshuttle assembly98 moves rightward from its position inFIG. 6B. As theshuttle assembly98 moves rightward, the lower track guides135,137, etc. disengage thevertical portions140 and142 such that thelower portion122 of theshuttle assembly98 moves upward and away from thesurface86. Vertically engaging and disengaging thechamber opening82 may significantly extend the life of the gasket and other components that form the seal with the chamber opening of the chamber.
• Next, the piston90 (FIG. 4) extends further until the piston surface92 (FIG. 4) is substantially coplanar with thesurface86. While thepiston90 is extending further, theshuttle assembly98 may temporarily halt its rightward movement.
• Then, as theshuttle assembly98 continues moving rightward, thewiper110 wipes the used coffee grounds (not shown inFIGS. 6A and6B) off of thepiston surface92 and into the solid-waste-disposal unit56 (FIG. 3).
• After thewiper110 moves past the edge of thesurface88, theshuttle assembly98 stops, and remains in this “home” position (not shown inFIGS. 6A and 6B) until thebrewing chamber80 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 thebrewing unit50, theshuttle assembly98 in a first disengaged position, and a shuttle-assembly drive150 according to an embodiment of the invention.
• The shuttle-assembly drive150 may include adrive belt152, drive gears154 and156, anattachment member158, asolenoid plunger160, and acleaning assembly162, which includes ascraper164, optional water jets (not shown inFIG. 7A), and pivots166 (only one shown inFIG. 7A). Theplunger160 is operable to engage and disengage thecleaning assembly162 as described below in conjunction withFIGS. 7A-8.
• Themember158 attaches theshuttle assembly98 to thebelt152, and the drive gears154 and156 turn clockwise to move the shuttle assembly to the left, and turn counterclockwise to move the shuttle assembly to the right. The shuttle-assembly drive150 may also include one or more stops (not shown) to limit the distance that theshuttle assembly98 can move in the left or right directions. In one implementation, the ends of thetracks136 and138 (FIGS. 6A-6B) provide such stops.
• FIGS. 7B and 7C show rightward movement of theshuttle assembly98 relative to the shuttle assembly's position inFIG. 7A according to an embodiment of the invention.
• FIG. 8 is an isometric view of the cleaningassembly162 ofFIGS. 7A-7C according to an embodiment of the invention. Thescraper164 may be made out of metal, rubber, or any other suitable material, and is disposed over the solid waste disposal unit56 (FIG. 3). And if the filter106 (FIGS. 4-7C) is concave, thescraper164 has the same contour so that it can contact the filter across its entire diameter. In addition to thescraper164 and thepivots166, the cleaningassembly162 may includewater jets168, which are adjacent to the scraper. Although not shown, the water-measuring-and-transporting unit40 (FIG. 3) may feed to thejets168 heated water from the reservoir36 (FIG. 3), or may feed to the jets heated water from the reservoir mixed with cleaning solution from the cleaner-dispensing unit34 (FIG. 3). Flexible tubing or another type of conduit may connect the water-measuring-and-transportingunit40 to thewater jets168. Alternatively, thewater jets168 may be fed directly from the tap-water inlet (FIG. 3) or from another water or cleaning-solution source.
• Referring toFIGS. 7A-8, the operation of the cleaningassembly162 is described according to an embodiment of the invention.
• Thescraper164 and water (or cleaning solution) discharged from thewater jets168 clean thefilter106 and thewiper110.
• As discussed above in conjunction withFIGS. 6A-6B and as shown inFIG. 7A, after thebrewing unit50 brews coffee, the shuttle-assembly drive150 moves theshuttle assembly98 upward and to the right such that thewiper110 begins sweeping the spent coffee grounds from thesurface92 of thepiston90 into the solid-waste-disposal unit56.
• In addition, the controller64 (FIG. 3) extends theplunger160 toward thebrewing unit50 to rotate thecleaning assembly162 about thepivots166 such that the top edge of thescraper164 is substantially coplanar with the underside of thefilter106. The solenoid plunger may be designed to extend no further than the desired position, or a sensor (not shown) may indicate to thecontroller64 when thescraper164 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 cleaningassembly162 into the proper position.
• Referring toFIG. 7B, as theshuttle assembly98 continues to move rightward, thescraper164 contacts the underside of thefilter106 and dislodges spent coffee grounds and, if present, other residue (neither shown inFIGS. 7A-7C) that stuck to the underside of the filter as thepiston90 was forcing brewed coffee through the filter. Water (or cleaning solution) discharged from thejets168 facilitates the dislodging of the spent coffee grounds and residue from thefilter106, and, depending on the jets' spray pattern, may also keep thescraper164 free of coffee grounds and other residue. Because thescraper164 andjets168 are positioned over the solid-waste-disposal unit56 (FIG. 3), the dirty water, dislodged coffee grounds, and other residue fall into the disposal unit. And if thefilter106 includes a disposable cloth or paper portion on its underside, then thescraper164 may also remove this portion such that it falls into thedisposal unit56 along with the spent coffee grounds and other residue.
• Referring toFIG. 7C, after thefilter106 moves over thescraper164, thewiper110 moves over the scraper, which contacts the bottom of the wiper. Thescraper164, together with water (or cleaning solution) discharged from thejets168, dislodges spent coffee grounds and, if present, other residue stuck to the wiper. As discussed above, because thescraper164 and thejets168 are positioned over the solid-waste-disposal unit56 (FIG. 3), the coffee grounds and other residue dislodged from thewiper110 fall into the disposal unit. After thewiper110 moves rightward past thescraper164, thejets168 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 unit56.
• FIG. 9 is a block diagram of the grinding-and-measuringunit60 ofFIG. 3 according to an embodiment of the invention.
• The grinding-and-measuringunit60 includes anelectric motor170 that is powered by a supply voltage V and that is responsive the controller64 (FIG. 3), ashaft172, agrinder174, and adischarge port176. The grinding-and-measuring unit may also include acurrent sensor178 or atemperature sensor180.
• Themotor170 drives thegrinder174 via theshaft172 in response to the controller64 (FIG. 3).
• Thegrinder174 may be any suitable device for grinding coffee beans or another substance from which a beverage may be brewed.
• Thedischarge port176 provides the ground coffee from thegrinder174 to the grind-transporting unit54 (FIG. 3), or directly to the beverage-brewing unit50 (FIG. 3) if the brewing machine30 (FIG. 3) lacks the grind-transporting unit.
• Thecurrent sensor178 generates and provides to the controller64 (FIG. 3) a signal that indicates the amount of current that themotor172 draws, and thetemperature sensor180 generates and provides to the controller a signal that indicates the temperature of the motor.
• In operation, the controller64 (FIG. 3) determines that the amount of ground coffee discharged from theport176 equals the product of the grind rate of thegrinder174—the grind rate may be stored in thecontroller memory68—and amount of time that themotor170 is “on”. Because the instantaneous grind rate of thegrinder174 may depend on the amount of material that the grinder is grinding, and thus discharging through theport176, at that instant, thecontroller64 may also base the ground-coffee measurement on the current that themotor170 draws, on the temperature of the motor, or both the current drawn and the temperature. At any one instant, the load on themotor170 is proportional to the amount of ground coffee that thegrinder176 discharges through theport176, and the current that the motor draws is proportional to the load. Therefore, the higher that rate at which thegrinder174 discharges ground coffee through theport176, the higher the load on themotor170, 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 themotor170, the smaller the amount of ground coffee that thegrinder174 is discharging through theport176. Consequently, thecontroller64 can measure the amount of coffee discharged from theport176 by monitoring the signals from the current andtemperature sensors178 and180 and applying an algorithm that relates the values of these signals to the rate at which thegrinder174 discharges ground coffee through theport176. Alternatively, the grinding and measuringunit60 may omit one or both of the current andtemperature sensors178 and180, and thecontroller64 may measure the amount of ground coffee discharged from theport176 by monitoring only the signal from the included one of the current and temperature sensors (if one is included).
• When the controller64 (FIG. 3) determines that thegrinder174 has generated and discharged through the port176 a predetermined amount of ground coffee, the controller deactivates themotor170.
• FIG. 10 is a side view with portions broken away of a ground-coffee measuring assembly190 of the grinding-and-measuringunit60 ofFIG. 3 according to another embodiment of the invention, where like numbers reference components common toFIGS. 9-10. Theassembly190 can replace or supplement the controller's calculation of the amount of ground coffee discharged via thedischarge port176 based on the grind rate of the grinder174 (FIG. 9) and the signals from none, one, or both of the current andtemperature sensors178 and180 ofFIG. 3, and is disposed within the discharge port. Alternatively, theassembly190 may be disposed in another suitable location within the grinding-and-measuringunit60.
• Theassembly190 includes amotor192, aspeed sensor194, ashaft196, and adisk198 having anupper surface200.
• Themotor192 is an electric or other suitable motor that is separate from the grinder motor170 (FIG. 9) and that spins theshaft196 and thedisk198 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.
• Thespeed sensor194 generates a signal that indicates the rotational speed of thedisk198, and provides this signal to the controller64 (FIG. 3).
• Thedisk198 is substantially flat, relatively lightweight, and is formed from plastic or another suitable material. Furthermore, thedisk198 may have holes (not shown inFIG. 10) sufficiently wide to pass coffee grounds.
• In operation, the controller64 (FIG. 3) measures the amount of ground coffee (indicated by the arrows) discharged from theport176 based on the rotational speed of thedisk198. As ground coffee (indicated by the arrows) flows from the coffee grinder174 (FIG. 9) to theport176, the ground coffee collects on theupper surface200 of thedisk198 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 thesurface200 has a mass, it effectively changes the disk's rotational moment of inertia by an amount proportional to the mass of collected coffee. This change in the disk's moment of inertia changes the speed at which thedisk198 spins by an amount proportional to the change in the moment of inertia. Thecontroller64 monitors the speed of thedisk198 via the signal generated by thesensor194. Consequently, by integrating the speed of thedisk198 with respect to time, thecontroller64 can use an algorithm that relates the integrated disk speed to the amount of ground coffee that collects on thedisk surface200 over time to determine the amount of ground coffee discharged from theport176.
• Furthermore, the controller64 (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 grinder174 (FIG. 9). That is, the controller can calculate the amount of ground coffee that thegrinder174 generates in two ways: 1) based on a predetermined grind rate multiplied by the “on” time of the grind motor170 (FIG. 9) and none, one, or both of the motor temperature and current draw as described above in conjunction withFIG. 9; and, 2) using thedisk198. Because the second calculation may be more accurate than the first, thecontroller64 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 thecontroller64 may accomplish using known neural-network or other techniques, may allow thecontroller64 to accurately measure the amount of discharged ground coffee if, e.g., theassembly190 fails.
• When the controller64 (FIG. 3) determines that theport176 has discharged a predetermined amount of ground coffee, the controller deactivates the grinder motor170 (FIG. 3) and themotor192.
• FIG. 11 is a side view with portions broken away of a ground-coffee measuring assembly210 of the grinding-and-measuringunit60 ofFIG. 3 according to another embodiment of the invention, where like numbers are used to reference components common toFIGS. 9-11. Theassembly210 can replace or supplement the controller's calculation of the amount of ground coffee discharged via theport176 based on the grind rate of the grinder174 (FIG. 9) and the signals from none, one, or both of the current andtemperature sensors178 and180 ofFIG. 9; and, like theassembly190 ofFIG. 10, theassembly210 is disposed within thedischarge port176. Alternatively, theassembly210 may be disposed in another suitable location within the grinding-and-measuringunit60.
• Theassembly210 includes anemitter212 and asensor214. Theemitter212 emits abeam216 of electromagnetic energy such as light to thesensor214, which detects the intensity of the beam, generates a signal that indicates the intensity of the beam, and provides this signal to the controller64 (FIG. 3). For example, theemitter212 may be a light-emitting diode (LED), or a laser diode, and thesensor214 may be a photo detector.
• In operation, the controller64 (FIG. 3) measures the amount of ground coffee discharged from theport176 based on the intensity of thebeam216 detected by thesensor214. As ground coffee (indicated by the arrows) flows from the coffee grinder174 (FIG. 9) to theport176, at least some of the ground coffee passes through thebeam216. The more ground coffee passing through thebeam216 at any instant, the smaller the portion of the beam that strikes thesensor214, and thus the lower the beam intensity detected by the sensor. Thecontroller64 monitors the intensity of thebeam216 via the signal generated by thesensor214. Consequently, by integrating the intensity of thebeam216 with respect to time, thecontroller64 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 theport176.
• Furthermore, thecontroller64 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 grinder174 (FIG. 9) as described above in conjunction withFIG. 10.
• When the controller64 (FIG. 3) determines that theport176 has discharged a predetermined amount of ground coffee, the controller deactivates the grinding motor170 (FIG. 3).
• Moreover, in another implementation of theassembly210, theemitter212 is replaced with a combination emitter and detector, and thesensor214 is replaced with a reflector. Therefore, the emitter/detector212 emits thebeam216, thereflector214 reflects the beam, and the emitter/detector detects the intensity of the reflected beam. The controller64 (FIG. 3) measures the amount of ground coffee discharged through theport176 based on the intensity of the reflected beam as described above.
• FIG. 12 is a diagram of the beverage-brewing unit50 and a ground-coffee measuring assembly220 of the grinding and measuringunit60 ofFIG. 3 according to another embodiment of the invention, where like numbers are used to reference components common toFIGS. 9-12. Theassembly220 can replace or supplement the controller's calculation of the amount of ground coffee discharged via theport176 based on the grind rate of the grinder174 (FIG. 9) and the signals from none, one, or both of the current andtemperature sensors178 and180 ofFIG. 9, and is disposed external to thedischarge port176. Alternatively, theassembly220 may be disposed in another suitable location within the grinding-and-measuringunit60. Furthermore, although for purposes of explanation theassembly220 is shown transporting ground coffee directly to thebrewing chamber80, theassembly220 transports the ground coffee to the ground-transporting unit54 (FIG. 3) where the brewing machine30 (FIG. 3) includes the ground-transporting unit. Alternatively, theassembly220 may compose all or part of the ground-transportingunit54.
• Theassembly220 includes a measuring, i.e., dosing,cup222, ascale224, and a cup drive assembly (the operation of which is indicated by the dashed line inFIG. 12). Thedosing cup222 is kinematically decoupled from the cup drive assembly when the cup is on thescale224. “Kinematically decoupled” means that the drive assembly exerts no force on thecup222, so that the weight indicated by thescale224 is not corrupted by the drive assembly.
• Thedosing cup222 receives ground coffee (represented by the solid line arrow) discharged from theport176, and thescale224 weighs the ground coffee and the cup and provides to the controller64 (FIG. 3) a signal that indicates this weight. Because thescale224 may be sensitive to vibrations caused by the beverage-brewing machine30 (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 thecontroller64 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, thecontroller64 may turn off the grinder motor170 (FIG. 9) to eliminate the vibrations therefrom, measure the weight of thecup222 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 thecup222 from thescale224 to theopening82 of thebrewing chamber80, and tips the cup such that the ground coffee falls from the cup into the brewing chamber. The drive assembly may also “bang” thecup222 to dislodge into thebrewing chamber80 ground coffee that is stuck to the bottom or sides of the cup.
• In operation, the controller64 (FIG. 3) determines from the signal (or multiple signals per above) generated by thescale224 the weight of ground coffee discharged from theport176. Ground coffee (indicated by the arrows) exits theport176 and enters thecup222. Thescale224 weighs thecup222 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. Thecontroller64 monitors the combined weight of the coffee and the cup via the one or more signals generated by thescale224. From the combined weight of the ground coffee and thecup222, thecontroller64 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 memory68 (FIG. 3). To prevent overfilling of thecup222, thecontroller64 may stop the grinder motor170 (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 controller64 (FIG. 3) determines that theport176 has discharged a predetermined weight of ground coffee into thecup222, the controller deactivates the grinding motor170 (FIG. 9) and causes the cup drive assembly (represented by the dashed line) to dump the ground coffee in thecup222 into thebrewing chamber180. Then thecontroller64 causes thecup222 to return to its “home” position on thescale224.
• FIGS. 13-18 illustrate the operation of the beverage-brewing machine30 ofFIG. 3 during a beverage-brewing cycle according to an embodiment of the invention, where like numbers reference components common toFIGS. 3-18. For clarity of explanation,FIGS. 13-18 omit some features discussed above in conjunction withFIGS. 3-12, it being understood that these features may be present even though they are not shown or discussed. For example, althoughFIGS. 13-18 do not show thelinkage members126 and128 and track guides130,132,134,135, and137, (FIGS. 5-7C) of theshuttle assembly98, the shuttle assembly may include these linkage members and track guides. Furthermore, although it may not be explicitly stated, thecontroller64 may control one or more of the below-described steps. Moreover, although the operation of themachine30 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 and13-18, the operation of thebeverage brewing machine30 during a beverage-brewing cycle is discussed according to an embodiment of the invention.
• Referring toFIG. 13, after a human operator (not shown in FIGS.3 and13-18) activates themachine30 by, e.g., turning “on” a power switch (not shown in FIGS.3 and13-18), themachine30 performs a self-check/initialization during which thepiston90 andshuttle assembly98 move into respective “home” positions if they are not already in their respective home positions. For example, thepiston90 moves into a position where thepiston surface92 is substantially coplanar with theblock surface88, and theshuttle assembly98 moves into a position in which theopening82 of thebrew chamber80 is partially or fully exposed. Alternatively, thepiston90 andshuttle assembly98 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 thecontrol panel70. For example, if thehopper unit58 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 and13-18) holding the beans of the desired roast. Furthermore, themachine30 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 thememory68 and associated with the identifier. Alternatively, the present operator, another operator, or the machine30 (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 themachine30 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 thecontroller64 converts into an actual coffee-to-water ratio in a pre-programmed manner. In addition, themachine30 may, via thedisplay70, remind the operator to place a cup in thecup holder44.
• Then, referring toFIG. 14, thepiston90 retracts a predetermined distance to leave enough room in thechamber80 for receivingground coffee230. Alternatively, if the home position of thepiston90 leaves sufficient room in thechamber80, then the piston need not retract.
• Next, the grinding-and-measuringunit60 and, if present, the grind-transportingunit54, load thebrewing chamber80 with a predetermined amount of theground coffee230. If the grinding-and-measuringunit60 can provide different grind sizes (e.g., coarse, fine), then the unit generates theground coffee230 having the selected grind size. Alternatively, theunit60 may provide different portions of theground coffee230 having different grind sizes. For example, theunit60 may provide an intermediate grind consistency by finely grinding the first half of theground coffee230 and coarsely grinding the second half of the ground coffee. Furthermore, because the grind size may affect the grind rate of the grinder174 (FIG. 9), thecontroller64 may take into account the grind size when measuring theground coffee230, particularly when using the (grind rate)×(grinding time) measuring technique described above in conjunction withFIG. 9.
• Referring toFIG. 15, after the grinding-and-measuringunit60, and, if present, the grind-transportingunit54, load theground coffee230 into thechamber80, theshuttle assembly98 seals theopening82 of thebrewing chamber80 as described above in conjunction withFIGS. 6A-6B.
• While the grinding-and-measuring and grind-transportingunits60 and54 are loading theground coffee230 into thechamber80 and while theshuttle assembly98 is sealing the chamber, the water-reservoir-and-heating unit36 is heating the water to a predetermined temperature if the water is not already at this temperature. In one example, theunit36 heats the water above the desired brewing temperature so that the water-temperature-control unit38 can provide to thechamber80 water at the desired brewing temperature by cooling the heated water from the reservoir with cold tap water as described above in conjunction withFIG. 3. In another example, the reservoir-and-heating unit36 heats the water to the brewing temperature, and the temperature-control unit38 is inactive or omitted. Either technique allows control of the brewing temperature from cup to cup.
• Next, the water-measuring-and-transportingunit40 fills the sealedbrewing chamber80 with a desired amount ofwater232 having the desired brewing temperature via thenozzle102. In one example, the water-and-measuringunit40 includes a pump that forces the desired amount ofwater232 through thenozzle102. In another example, the water-measuring-and-transportingunit40 lacks a pump, and thewater232 is gravity fed from thereservoir unit36 to thenozzle102 via the water-measuring-and-transporting unit. In these two techniques, the beverage-transportingunit48 may open theoutlet108 to allow air in thechamber80 to escape via the outlet as thewater232 enters the chamber. In yet another example, theoutlet108 is closed and thepiston90 retracts to create a suction that draws thewater232 from thereservoir36 into thechamber80 via the measuring-and-transportingunit40 and thenozzle102. In still another example, a combination of the pump and piston suction is used to fill thechamber80 with water.
• Still referring toFIG. 15, techniques for measuring the water that the water-measuring-and-transportingunit40 provides to thebrewing chamber80 are discussed. In one implementation, theunit40 includes a solenoid pump, which pumps water at a highly consistent rate. Therefore, thecontroller64 determines the amount of water that theunit40 provides to thebrewing chamber80 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 unit38, the temperature-control unit or the water-transportingunit40 may include sensors to indicate the pressure and temperature of the water, and thecontroller64 may take into account the pressure or temperature when measuring the amount ofwater232 provided to thebrewing chamber80.
• And in an implementation where thepiston90 draws in thewater232 by retracting, then thecontroller64 may measure the amount of water that enters thechamber80 by measuring the distance that thepiston90 retracts, and using an algorithm to relate the distance retracted to the amount of water drawn. Because the amount of water that thepiston90 draws into thechamber80 may depend on the temperature of the water and the temperature and pressure of the gas in the chamber and in other parts of themachine30, the machine may include temperature and pressure sensors in these parts of the machine, and thecontroller64 may take into account these temperatures and pressures when measuring the amount ofwater232 drawn into the chamber.
• In still another example, thewater232 enters thechamber80 or is measured using a combination or sub-combination of the above-described techniques.
• In a related implementation, thecontroller64 adjusts the amount ofwater232 introduced to thechamber80 based on the amount ofground coffee230 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, thecontroller64 can adjust the amount of one of theground coffee230 andwater232 based on the measurement of the other. Because the water measurement is typically more accurate than the coffee measurement, thecontroller64 adjusts the amount of water based on the measured amount ofground coffee230 in thechamber80. 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 thecontroller64 determines that 33 grams of coffee were introduced into thechamber80. To maintain the 3/1 ratio, thecontroller64 causes the water-measuring-andtransportation unit40 to introduce 11 ounces of water into the cylinder. Themachine30 can then discard one ounce of the brewed coffee via the liquid-waste disposal unit42 as further described below in conjunction with the discussion of “silt” so that only the desired 10 ounces of coffee fill the operator's coffee cup (not shown in FIGS.3 and13-18). Although the coffee-to-water ratio may still be off due to errors in measuring thecoffee230 andwater232, the ratio is typically more accurate than it would have been had the amount of water not been adjusted as described above. Thecontroller64 may use this technique when toolittle coffee230 is in thechamber80 by introducing less water into the chamber, although this will result in less than the selected amount of coffee in the operator's cup. Alternatively, thecontroller64 may cause the grinder174 (FIG. 9) to grind some additional coffee.
• Still referring toFIG. 15, after the desired amounts ofground coffee230 andwater232 are in thechamber80, themachine30 agitates the mixture of the ground coffee and the water to thoroughly wet the ground coffee. In one example, the spray pattern from thenozzle102 performs this agitation while thewater232 is entering thechamber80. To enhance the agitation, thewater232 may enter thechamber80 in multiple bursts. In another example, a mechanical member (not shown in FIGS.3 and13-17) performs the agitation while thewater232 is entering thechamber80, after the water enters the chamber, or both while and after the water enters the chamber. In yet another example, both thenozzle102 and the mechanical member perform the agitation.
• Next, the mixture of theground coffee230 and thewater232 remains in thechamber80 for the selected brewing time. During the brewing time, thebrewing unit50 may heat or cool the mixture within thechamber80 as discussed above in conjunction withFIG. 4.
• Then, thecup sensing unit52 indicates whether a cup (not shown in FIGS.3 and13-18) is in theholder44. If a cup is not in the holder, then thecontroller64 halts the brewing cycle, and may sound an audio or visual alarm, until the operator places a cup in theholder44. If a cup is in theholder44, then the brewing cycle continues as described below.
• Referring toFIG. 16, after the brewing time has expired, thepiston90 extends to expel the brewedcoffee234 from thechamber80 and into a coffee cup (not shown in FIGS.3 and13-18) in thecup holder44 via the beverage-transporting and -dispensingunits48 and46. Thepiston90 forces the brewedcoffee234 through thefilter106, into thespace112, and through theoutlet108 to thebeverage transporting unit48. In one implementation, thepiston90 extends in multiple steps to allow the spentcoffee grounds230 to settle on thesurface92 of the piston. In another implementation, a pressure sensor (not shown in FIGS.3 and13-18) is located within thebrewing chamber80, and thecontroller64 controls the extension speed of thepiston90 in a closed-loop manner to maintain the pressure within thebrewing chamber80 at a desired level that prevents damage to, e.g., thefilter106 and the seal between theshuttle assembly98 and the brewing chamber.
• Still referring toFIG. 16, sometimes “silt” or other undesirable debris (not shown in FIGS.3 and13-18) that are too fine to be retained in thebrewing chamber80 by thefilter106 float near or to the top of the brewedcoffee234. To keep this debris out of the coffee cup (not shown in FIGS.3 and13-18), before thepiston90 begins to extend the beverage-transportingunit48 closes and the water-transportingunit40 opens. Therefore, as thepiston90 extends, a predetermined amount of the brewedcoffee234 including the debris is expelled into the liquid-disposal unit42. After thepiston90 expels the predetermined amount of brewedcoffee234 into thedisposal unit42, the beverage-transportingunit48 opens and the water-transportingunit40 closes such that the extending piston expels the remaining, and substantially debris free, brewedcoffee234 to the beverage-dispensingunit46. Thecontroller64 may cause thepiston90 to expel the desired amount of brewedcoffee234 into thedisposal unit42 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 thechamber80 by the retractingpiston90 as described above). Furthermore, thecontroller64 may introduceadditional ground coffee230 andwater232 into thechamber80 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 thecontroller64 may introduce 27 grams ofground coffee230 and 9 ounces ofwater232 into thechamber80. This maintains the desired coffee-to-water ratio and cup size while allowing thepiston90 to expel 1 ounce of debris-ridden brewedcoffee234 into the liquid-waste disposal unit42.
• Referring toFIG. 17, thepiston90 stops extending and expelling the brewed coffee234 (not shown inFIG. 17) when thepiston surface92 is a predetermined distance below theblock surface88. This predetermined distance is sufficient to prevent the spentcoffee grounds234 from pressing against thefilter106 with a force sufficient to damage the filter, the seal between thechamber80 and theshuttle assembly98, or other components of the shuttle assembly.
• Then, thecontroller64 may indicate to the operator via thedisplay70 or other indicator (not shown in FIGS.3 and13-18) that he may remove the coffee-filled cup (not shown in FIGS.3 and13-18) from thecup holder44.
• Referring toFIG. 18, theshuttle assembly98 next moves upward and away from thechamber80, and thepiston90 extends until thepiston surface92 is substantially coplanar with theblock surface88.
• Next, theshuttle assembly98 moves rightward such that thewiper110 sweeps the spentcoffee grounds230 from thepiston90 and into the solidwaste disposal unit56.
• Still referring to FIGS.3 and13-18, 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 toFIGS. 3 and 16, the operation of the beverage-brewing machine30 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 ofFIGS. 13-18 may perform or be modified to perform the same or similar functions during the cleaning cycle.
• After an operator (not shown inFIGS. 3 and 16) activates themachine30 by, e.g., turning “on” a power switch (not shown inFIGS. 3 and 16), he may initiate a cleaning cycle via thecontrol panel70, or the machine may initiate the cleaning cycle automatically. For example, themachine30 may automatically initiate the cleaning cycle at a predetermined time each day.
• Next, theshuttle assembly98 seals thebrewing chamber80.
• While theshuttle assembly98 is sealing thechamber80, the water reservoir andheating unit36 heats the water to a predetermined temperature if the water is not already at this temperature. In one example, theunit36 heats the water above the desired cleaning temperature so that the watertemperature control unit38 can provide to thechamber80 water at the desired cleaning temperature by cooling the heated water with cold tap water. In another example, the reservoir-and-heating unit36 heats the water to the cleaning temperature, and the temperature-control unit38 is inactive or omitted.
• Then, the water-and-cleaner-measuring-and-transportingunit40 fills the sealedbrewing chamber80 via thenozzle102 with a mixture comprising a predetermined amount of water and cleaning solution (e.g., vinegar) from thecleaner dispensing unit34. Theunit40 may measure the mixture using the same techniques and components used to measure the water during a brewing cycle as discussed above in conjunction withFIGS. 13-18. For example, the cleaningdispenser34 may provide a steady flow of cleaning solution to the transportingunit40, which provides a predetermined amount of water to thechamber80. Because theunit34 dispenses the cleaning solution at a known rate, the amount of cleaning solution dispensed is proportional to the amount of water that the transportingunit40 provides to thechamber80. Furthermore, while the cleaning mixture enters thechamber80, the beverage-transportingunit48 may open theoutlet108 to allow air in the chamber to escape. In another implementation, theoutlet108 is closed and thepiston90 retracts to creating a suction that draws the mixture of water and cleaning solution into thechamber80 via the measuring-and-transportingunit40 and thenozzle102. With this technique, thecontroller64 can measure the amount of cleaning mixture that enters thechamber80 using the same techniques to measure drawn-in water as discussed above in conjunction withFIGS. 13-18. In yet another implementation, the water-and-cleaner mixture enters thechamber80 using a combination or sub-combination of the above-described techniques. In still another implementation, the operator may pour the cleaning solution into thechamber80 via thechamber opening82.
• Next, themachine30 agitates the mixture of the cleaning solution and water. In one implementation, the spray pattern from thenozzle102 performs this agitation while the mixture is entering thechamber80. To enhance the agitation and cleaning of thechamber80, the mixture may enter the chamber in multiple bursts. In another example, a mechanical member (not shown inFIGS. 3 and 16) performs the agitation while the mixture is entering thechamber80, after the mixture enters the chamber, or both while and after the mixture enters the chamber. In yet another example, both thenozzle102 and the mechanical member agitate the cleaning mixture.
• Then, the cleaning mixture remains in thechamber80 for a predetermined cleaning time, during which thepiston90 may move up or down to enhance the cleaning of thechamber80 and the piston.
• After the cleaning time has expired, thecup sensing unit52 indicates to thecontroller64 whether a cup is in thecup holder44. If a cup is present, then thecontroller64 halts the cleaning cycle and may sound an audible or visible alarm until the cup is removed from the holder.
• If thecup sensing unit52 indicates that no cup is in thecup holder44, thepiston90 extends to expel the cleaning mixture from thechamber80 and into thedrain unit44 via the beverage-transporting-and-dispensingunits48 and46. Thepiston90 forces the cleaning mixture through thefilter106, into thespace112, and through theoutlet108 to the beverage-transportingunit48. The cleaning mixture cleans thefilter106, thespace112, theoutlet106, the beverage-transporting-and-dispensingunits48 and46, the cup-holder-and-drain unit44, and the conduits connecting these components as the mixture passes through.
• Thepiston90 stops extending and expelling the cleaning mixture when thepiston surface92 is substantially coplanar with theblock surface88.
• Next, themachine30 repeats the above-described cycle one or more times with water only to rinse the cleaned components and conduits.
• Then, theshuttle assembly98 disengages thechamber80 in preparation of the next brewing cycle.
• Still referring toFIGS. 3 and 16, other embodiments of the cleaning cycle are contemplated. For example, instead of mixing cleaning solution with water, the cleaner-measuringunit40 may provide straight (i.e., unmixed with water) cleaning solution from thedispenser34 to thebrewing chamber80. 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 themachine30 according to an embodiment of the invention.
• Referring toFIGS. 3 and 19, in addition to the cup-holder-and-drain unit44 and the control panel anddisplay70, themachine30 includes a stainless steel andplastic housing240,hoppers242 and244, abeverage dispensing spout246, atray248, and three doors orpanels250,252, and254. Each of thehoppers242 and244, which are part of thehopper unit58, can hold the same or different types of coffee beans. The dispensingspout246 is part of the beverage-dispensingunit48, and thetray248, which is removable for cleaning, is part of the cup-holder-and-drain unit44. The door/panel250 allows access for emptying or servicing the solid-waste-disposal unit56, and the door/panel252 allows access for servicing some or all of the components above thebarrier62 inFIG. 3. The door/panel254 allows access for servicing the printed circuit board (not shown inFIGS. 3 and 19) on which theprocessor66,memory68,communications port72, and perhaps other electronic components are located. The height of themachine30 is 18 inches or less so that the machine can fit on a counter top under standard-height cabinets (neither shown inFIG. 19). Because this height may be too small to allow water from thereservoir unit36 to gravity feed into the brewing chamber80 (not shown inFIGS. 3 and 19), the water-transportingunit40 may include a pump, or thepiston90 may retract to draw water into the brewing chamber as described above in conjunction withFIGS. 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.

Claims (43)

1. A machine for brewing a beverage, the machine comprising:

a chamber; and

a piston disposed within the chamber and operable to move to a first position to allow the chamber to receive a liquid and a flavor base, to remain in the first position for a time sufficient for the beverage to brew, and to move to a second position to dispense the beverage by forcing the beverage out of the chamber.

2. The machine ofclaim 1, further comprising a controller operable to control the movement of the piston.

3. The machine ofclaim 1 wherein the chamber and piston are cylindrical.

4. The machine ofclaim 1 wherein:

the first position of the piston comprises a retracted position; and

the second position of the piston comprises an extended position.

5. The machine ofclaim 1 wherein:

the flavor base comprises coffee; and

the liquid comprises water.

6. The machine ofclaim 1, further comprising:

wherein the flavor base comprises a solid; and

a filter operable to pass the beverage and retain the solid in the chamber while the piston moves from the first position to the second position.

7. The machine ofclaim 1, further comprising:

wherein the flavor base comprises a solid; and

a wiper operable to remove the solid from the piston after the beverage is dispensed.

8. The machine ofclaim 1, further comprising:

a hopper operable to store coffee beans; and

a grinder operable to receive the coffee beans from the hopper, to grind the coffee beans, and to provide the ground coffee to the chamber as the flavor base.

9. The machine ofclaim 1, further comprising:

a hopper operable to store the flavor base; and

a measuring unit operable to receive the flavor base from the hopper and to provide a predetermined amount of the flavor base to the chamber.

10. The machine ofclaim 1, further comprising:

a hopper operable to store the flavor base; and

a transporter operable to provide the flavor base from the hopper to the chamber during a first operating mode and operable to provide the flavor base to a disposal unit during a second operating mode.

11. The machine ofclaim 1, further comprising a reservoir operable to hold the liquid, to heat the liquid to a predetermined temperature, and to provide the heated liquid to the chamber.

12. The machine ofclaim 1, further comprising:

a reservoir operable to hold the liquid and to heat the liquid to a first predetermined temperature; and

a temperature-control unit operable to receive the heated liquid from the reservoir, to change the temperature of the liquid from the first predetermined temperature to a second predetermined temperature, and to provide the liquid having the second predetermined temperature to the chamber.

13. The machine ofclaim 1, further comprising:

a reservoir operable to hold the liquid and to heat the liquid to a first predetermined temperature; and

a temperature-control unit operable to receive the heated liquid from the reservoir, to cool the liquid to a second predetermined temperature, and to provide the cooled liquid to the chamber.

14. The machine ofclaim 1, further comprising:

a reservoir operable to hold a cleaner; and

a transporter operable to provide the cleaner from the reservoir to the chamber during a cleaning operating mode.

15. The machine ofclaim 1, further comprising:

a holder operable to hold a beverage cup; and

wherein the piston is operable to dispense the beverage into the cup.

16. The machine ofclaim 1, further comprising:

a holder operable to hold a beverage cup;

a sensor operable to indicate whether the beverage cup is in the holder; and

wherein the piston is operable to dispense the beverage if the sensor indicates that the beverage cup is in the holder.

17. A method, comprising:

brewing a beverage in a chamber from a flavor base and a liquid; and

forcing the beverage out of the chamber by moving a piston within the chamber.

18. The method ofclaim 17 wherein producing the beverage comprises brewing coffee in the chamber from ground coffee and water.

19. The method ofclaim 17 wherein forcing the beverage comprises forcing the beverage through a filter to remove a solid from the beverage.

20. The method ofclaim 17, further comprising:

introducing the flavor base into the chamber; and

introducing the liquid into the chamber in a manner that mixes the flavor base and the liquid.

21. The method ofclaim 17, further comprising:

introducing the flavor base into the chamber; and

introducing the liquid into the chamber in multiple bursts.

22. The method ofclaim 17, further comprising wiping a solid residue from the piston into a waste-disposal unit after forcing the beverage out of the chamber.

23. The method ofclaim 17, further comprising:

receiving a beverage-producing parameter; and

producing the beverage according to the parameter.

24. The method ofclaim 17, further comprising:

electronically receiving a beverage-producing parameter; and

producing the beverage according to the parameter.

25. A machine for brewing coffee, the machine comprising:

a brew chamber having an opening operable to receive ground coffee;

a reservoir operable to hold water, to heat the water to a first predetermined temperature, and to provide heated water to the brew chamber;

a filter;

a piston disposed in the chamber and operable to force brewed coffee out of the chamber through the filter; and

a wiper operable to sweep the ground coffee off of the piston after the piston forces the brewed coffee out of the chamber.

26. The machine ofclaim 25, further comprising:

a hopper operable to store coffee beans; and

a grinding-and-measuring unit operable to receive coffee beans from the hopper, to grind the beans into ground coffee, and to introduce a predetermined amount of ground coffee into the brew chamber.

27. The machine ofclaim 26 wherein the grinding and measuring unit comprises an optical sensor operable to indicate an amount of ground coffee that the unit introduces to the brew chamber.

28. The machine ofclaim 26 wherein the grinding and measuring unit comprises an ultrasonic sensor operable to indicate an amount of ground coffee that the unit introduces to the brew chamber.

29. The machine ofclaim 26 wherein the grinding and measuring unit comprises a disk operable to indicate an amount of ground coffee that the unit introduces to the brew chamber.

30. The machine ofclaim 26 wherein the grinding and measuring unit comprises:

a grinding motor; and

a current sensor operable to indicate an amount of ground coffee that the unit introduces to the brew chamber based on a current drawn by the grinding motor.

31. The machine ofclaim 26 wherein the grinding and measuring unit comprises:

a grinding motor; and

a temperature sensor operable to indicate an amount of ground coffee that the unit introduces to the brew chamber based on a temperature of the grinding motor.

32. The machine ofclaim 26 wherein the grinding-and-measuring unit comprises:

a container operable to hold the ground coffee;

a mass sensor operable to indicate a mass of the ground coffee held in the container; and

a mechanism to dump the ground coffee in the container into the brew chamber.

33. The machine ofclaim 26 wherein the grinding-and-measuring unit comprises:

a container operable to hold ground coffee; and

a mechanism to dump the ground coffee in the container into the brew chamber.

34. The machine ofclaim 26 wherein the grinding-and-measuring unit comprises:

a container operable to hold ground coffee; and

a mass sensor operable to indicate a mass of the ground coffee held in the container.

35. The machine ofclaim 25, further comprising a water transporting unit disposed between the reservoir and the brew chamber and operable to receive heated water from the reservoir and to introduce a predetermined amount of the heated water into the chamber via the opening.

36. The machine ofclaim 25 further comprising a water transporting unit disposed between the reservoir and the brew chamber and operable to receive heated water from the reservoir and to introduce a predetermined amount of the heated water into the chamber via the opening, wherein the water transporting and measuring unit comprises a pump that introduces the water into the brew chamber at a rate that is proportional to a time during which the pump is active.

37. The machine ofclaim 25 wherein the piston is operable draw a predetermined amount of heated water from the reservoir into the chamber by moving a distance that corresponds to the predetermined amount.

38. The machine ofclaim 25 wherein:

the filter is operable to cover the opening of the brew chamber; and

the piston is operable to force the brewed coffee out of the chamber via the opening and through the filter.

39. The machine ofclaim 25, further comprising a temperature unit disposed between the reservoir and the water transporting and measuring unit and operable to cool the water from the reservoir to a second predetermined temperature.

40. The machine ofclaim 25 wherein the wiper and the filter are attached to a common assembly.

41. The machine ofclaim 25, further comprising an electronic controller operable to control operation of the grinding and measuring unit, the reservoir, the water transporting and measuring unit, the piston, and the wiper.

42. The machine ofclaim 25, further comprising:

a substantially flat surface contiguous with the opening of the brew chamber;

wherein the piston has a surface and is operable to move into a wipe position where the piston surface is substantially coplanar with the contiguous surface after the piston forces the brewed coffee out of the chamber; and

wherein the wiper is operable to sweep the ground coffee from the piston surface when the piston is in the wipe position.

43. The machine ofclaim 25, further comprising a cleaning mechanism operable to remove ground coffee from the filter and the wiper after the wiper sweeps the coffee grounds from the piston.

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