Abstract:
A portafilter apparatus for an espresso machine, the apparatus comprising: a metal head that is attachable to a group head of the espresso machine, the head defines a coffee grounds compartment for containing a quantity of ground coffee; and a perforated movable floor within the head; the floor forms a filter and defines the base of the coffee grounds compartment, the floor is vertically movable with respect to the head to adjust a volume of the coffee grounds compartment.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to portafilters and more particularly to a portafilter with variable volume adjustment. 
       BACKGROUND OF THE INVENTION 
       [0002]    Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field. 
         [0003]    A portafilter is a device that attaches onto the group head of an espresso making machine and that carries a quantity or dose of ground coffee in a compartment with a perforated floor that acts as a filter. The compartment is sometimes referred to as a basket and in some portafilters, the basket is interchangeable. Baskets of different capacity and flow characteristics may thereby be interchanged with one another. For example, a double-shot of ground coffee requires a basket with a 12-14 gram capacity. A single-shot basket might hold, for example, 6-7 grams. Some portafilters can receive a basket for a triple-shot, thereby having a ground coffee capacity of 18-21 grams. Even when a portafilter can receive interchangeable baskets, the grind capacity of any single basket is generally fixed because obtaining an optimal brew requires the fill height of the ground coffee in the basket to remain relatively constant. 
         [0004]    Optimising the coffee brewing process also requires that the head of the portafilter be pre-heated to reach an optimal working temperature. Gauging whether or not the head of an ordinary portafilter has reached the pre-heat temperature is difficult, particularly if the portafilter has been disengaged from the group head for some time before being re-used. 
         [0005]    In a machine where different ground coffee quantities are sought to be brewed, neither the coffee grinder that dispenses the grounds into the portafilter nor the coffee machine that dispenses the hot water through the portafilter are able to compensate for the different ground coffee quantities other than by user command or human input directly into the grinder or machine. 
         [0006]    A portafilter can be particularly adapted for either a single-shot and have a single spout or a double-shot and have a double spout. 
         [0007]    The present invention addresses the above limitations in the coffee brewing process. 
       SUMMARY OF THE INVENTION 
       [0008]    According to an embodiment there is provided a portafilter having a basket whose volume is adjustable. 
         [0009]    According to an embodiment there is provided a portafilter having a basket whose volume is continuously adjustable. 
         [0010]    According to an embodiment there is provided a portafilter that can sense and display or communicate its own temperature. 
         [0011]    According to an embodiment there is provided a portafilter that can wirelessly communicate parameters such as basket volume and temperature to an espresso making machine or a coffee grinder. 
         [0012]    According to an embodiment there is provided a portafilter having both a single spout and a double spout. 
         [0013]    According to an embodiment there is provided a portafilter apparatus for an espresso machine, the apparatus comprising:
       a metal head that is attachable to a group head of the espresso machine,   the head defines a coffee grounds compartment for containing a quantity of ground coffee; and   a perforated movable floor within the head; the floor forms a filter and defines the base of the coffee grounds compartment, the floor is vertically movable with respect to the head to adjust a volume of the coffee grounds compartment.       
 
         [0017]    The apparatus may further include: a handle coupled to the head; and a volume adjustment selector located about the free end of the handle is operatively associated with the floor, such that rotation of the selector causes the floor to raise or lower with respect to the head. 
         [0018]    The perforated floor may be supported by a moving floor body. The body may include a vertical thread rack that is driven by a pinion and bevel gear assembly; the pinion and bevel gear assembly is rotated by a main shaft that passes through the handle. Rotation of the volume adjustment selector may cause rotation of the shaft to raise or lower the floor with respect to the head. 
         [0019]    A gearbox located about the free end of the handle may terminates the shaft, such that rotation of the volume adjustment selector actuates the gearbox to cause rotation of the shaft. The gearbox may be in the form of a planetary gearbox. 
         [0020]    Hot water from the group head may enters an open mouth of the compartment, passes through the ground coffee and exits the compartment through the perforated floor. 
         [0021]    The floor may be associated with a circumferential seal that extends between the floor and an interior side wall of the compartment. 
         [0022]    Volume of the coffee grounds compartment may be continuously adjustable between a predefined minimum volume and a predefined maximum volume. 
         [0023]    A controller module may receive signals from one or more sensors associates with the portafilter. A temperature sensor may measure the temperature of the head and transmits a signal indicative of the temperature state to the controller module. A position sensor may provide a signal indicative of a volume state of the coffee grounds compartment to the controller module. The position sensor may measure a rotational position of the selector or main shaft 
         [0024]    A display module may be coupled to the controller module for presenting information of a state indicated by the one or more sensors. 
         [0025]    A receiver may receive a data signal from an appliance for configuring settings of the controller module. A receiver may receive electromagnetic energy to charge an internal power source and/or it capacitor for powering the controller module. The receiver may be in the form of a wireless receiver. 
         [0026]    A transmitter may transmit a data signal to an associated appliance for configuring setting of the associated appliance. The transmitter may transmit a data signal indicative of a volume of the coffee grounds compartment to the espresso machine for configuring a water delivery volume. The transmitter may transmit a data signal indicative of a volume of the coffee grounds compartment to a coffee grinder machine for configuring a ground coffee delivery volume. The transmitter may be in the form of a wireless transmitter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0027]    In order that the invention be better understood, reference is now made to the following drawing figures by way of example, in which: 
           [0028]      FIG. 1  is a perspective view of a portafilter having a variable volume compartment. 
           [0029]      FIG. 2A  is a cross sections through the portafilter shown in  FIG. 1 . 
           [0030]      FIG. 2B  is a cross sections through the portafilter shown in  FIG. 1 . 
           [0031]      FIG. 3  is an exploded perspective view of the portafilter depicted in  FIG. 1 . 
           [0032]      FIG. 4  is a perspective view of the portafilter shown in  FIG. 1 , with double spout in place. 
           [0033]      FIG. 5  is a perspective view of the portafilter shown in  FIG. 11 , with single spout in place. 
           [0034]      FIG. 6  is a perspective view of a portafilter having an internal processor, a graphic display and other features. 
           [0035]      FIG. 7  is a perspective view of a portafilter with an electronic display. 
           [0036]      FIG. 8  is a perspective view of a portafilter having a mechanical display. 
           [0037]      FIG. 9  is a schematic diagram of a network comprising a coffee grinder, portafilter, coffee machine and communications device. 
           [0038]      FIG. 10  is a schematic diagram of an espresso coffee machine having a processor controlled grind adjustment and other features. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]    As shown in  FIG. 1 , a portafilter  100  has a metal head  101  with male bayonet features  102  that attaches to the group head of an espresso making machine. The head  101  has a coffee grounds compartment  103  for containing a quantity or dose of ground coffee. Hot water from the group head enters the open mouth  104  of the compartment  103 , passes through the ground coffee and exits the compartment  103  through a perforated floor  105  that forms the filter of the compartment  103 . Brewed coffee that passes through the filter  105  is dispensed from a spout  106 , The head  101  is retained by a handle  107 . In this example, the floor  105  of the compartment is adjustable vertically  108  in accordance with the rotation of a selector  110 , for example a rotatable knob, located at the free end of the handle  107 . 
         [0040]    As shown in  FIG. 2A  and  FIG. 2B , the perforated filter or floor  105  is associated with a circumferential seal  200  that extends between the vertically adjustable floor  105  and the interior side wall  201  of the compartment or basket  103 . Thus, hot water entering the basket can exit only through the floor and not around it. In this example, the perforated filter or floor  105  is supported by a moving filter floor body  202 . The body  202  supports the floor  105  above a gap  203  that leads to a central discharge passageway  204 . The discharge passageway  204  terminates above and discharges onto the spout  106 . The body  202 , in this example, incorporates a vertical gear rack or thread  205  that is driven by, in this example, a pinion and bevel gear assembly  206 . The pinion and bevel gear assembly  206  is rotated by a main shaft  207  that passes through the handle and terminates at a gear box, for example, a planetary gear box  208  that is actuated by the portafilter&#39;s rotating selector  110 , for example as rotatable knob. 
         [0041]    As shown in more detail in  FIG. 3 , the gearbox assembly  208  is contained, at least partially, under the peripheral rim  301  of the rotating selector or knob, and between the selector/knob and the remainder of the handle  107 . The planetary gearbox assembly in this example comprises a gear housing  302  that supports three planetary gear shafts  303 . Each gear shaft supports a planetary gear  304 . The planetary gears  304  drive a planetary pinion gear  305  that is attached to a proximal end  306  of the main shaft  207 . The proximal ends of the planetary gear shafts  303  are retained by a gear housing cover  307  and the cover  307  is affixed to the gear housing with, in this example three axial, threaded fasteners  308 . In preferred embodiments, the planetary gearbox mechanism reduces the rotation of the selector  110  so that, for example, one full revolution of the selector  110  results in four revolutions of the main shaft  207 . 
         [0042]    The main shaft  207  is supported at one end by the planetary pinion gear  305  and at the distal end by a drive pinion gear  309 . As shown in  FIG. 2A  through  FIG. 3 , the drive pinion gear  309  is located beneath the filter floor body  202  and within the portafilter&#39;s head  101 . Thus, rotation of the selector  301  (for example, a rotatable knob) is transmitted by the main shaft  207 , through a central passageway  310  in the handle  107  and a second passageway  311  through the neck  312  of the head  101  to the drive pinion gear  309 . Rotation of the drive pinion gear  309  about the horizontal axis of the main shaft  207  causes a rotation of a drive bevel gear  313  about a vertical axis. The drive bevel gear  313  has a collar  314  that is internally threaded and that engages cooperating teeth or threads  315  located on the filter floor body  202 . 
         [0043]    In the example of  FIG. 3 , the filter floor  105  comprises a circular perforated disk having a descending rim  316  that cooperates with a groove  317  in the peripheral seal  200 . Flush fasteners  318  pass through cooperating openings  319  in the filter floor and thus serve to removeably clamp or retain the seal  200  between the floor  105  and the filter floor body  202 . The filter floor body  202  has threaded openings  319  for receiving the flush fasteners  318 . The perforated floor  105  and seal  200  can be removed for cleaning by withdrawing the threaded fasteners  318 . The filter flood body  202  may also be removed for cleaning, by rotating it to unseat the threads  315  from the internal threads of the collar  314 . This also provides access to the fasteners  340  that affix the cover  320  to the head  101 . 
         [0044]    The underside of the head  101  accommodates a cover  320 . In this example, the cover  320  has a peripheral rim  321  having a notch  322  that allows the main shaft  207  to pass through it. The cover  320  has an outlet rim  323  that is provided with an outlet cover  324  that receives a revolving 3-way spout  325 . Because the discharge opening of the outlet  323  is eccentric, (see  FIG. 2A  through  FIG. 3 ) brewed coffee being discharged from the passageway  204  will fall onto an inverted “U” shaped dual spout  326  (see  FIG. 4 ) or a single spout  327  (see  FIG. 5 ) depending on the rotational orientation of the spout outlet  325 . 
         [0045]    As shown in  FIG. 6 , a portafilter too, may have a head  101  or neck  312  in which is internally incorporated a temperature sensor such, as a thermistor  601 . In this example, the thermistor measures the temperature of the metallic head  101  and transmits the relevant signal information to a controller or processor  602  located within the handle  107 . The controller  602  is adapted to drive an electronic graphic display  603  located, in this example, on an upper surface of the handle  107  adjacent the neck  312 . In preferred embodiments, the handle also has within it, a position sensor  604  that cooperates with, for example, the selector  110  or the rotating main shaft  207 . The rotational position of the shaft, because it drives the vertically reciprocating floor  105  is indicative of the internal volume or working capacity of the basket or compartment  103 . The position sensor  604  transmits data to the processor  602  which in turn is adapted to provide a graphic indication, either numerically or symbolically on the display  603 . Power required for the processor, instrumentation and display is provided by an internal battery or capacitor  605  located within the handle  107 . In particularly preferred embodiments, data relating to the output of the temperature sensor  601  and the position sensor  604  can be transmitted wirelessly by a combination transmitter and optimal receiver  606  also located within the handle  107 . Data signals received by the receiver  606  can be processed by the controller  602  and displayed on the display area  603 . The receiver  606  may also be used to receive electromagnetic energy and use that energy to charge the internal battery or capacitor  605 . 
         [0046]    As shown in  FIG. 7 , the electronic display  603  is adapted to indicate, either alphanumerically  701  or symbolically  702  (or both), the volume or working capacity of the compartment  103 , in real time as the selector  110  is rotated. The electronic display  603  can also provide an alphanumeric or graphic symbol  704  that indicates when the correct pre-heat temperature has been achieved in the head  101  as recorded by the temperature sensor  601 . 
         [0047]    As an alternative to an electronic display, an as suggested by  FIG. 8 , a mechanical display  800  may be provided on an upper surface of the handle  107 . In this example, rotation of the main shaft  207  is converted by a gear mechanism  801  into the linear movement of a sliding pointer  802  that is carried within a slot  803  formed on an upper surface of the handle  107 . Index marks  804  next to the slot  803  provide an indication of the internal volume of the compartment  103 . 
         [0048]    As a further alternative to an electronic display, a plurality of incremental indicators may be printed, or formed on the surface of the handle and/or selector (e.g. rotatable knob) that correspond to the user selection or perimeter or measured state. 
         [0049]    It will be appreciated that the aforementioned adjustment mechanism that controls the height of the filter floor and thus the volume of the compartment  103  is continuous or stepless. Tactile feedback and/or graphical feedback and/or audio feedback can be provided to the user for indicating advancement of the selector and resultant movement of the compartment floor. 
         [0050]    As shown in  FIG. 9  and  FIG. 10 , a portafilter  100  constructed in accordance with the above teachings can form part of a wireless network in conjunction with a coffee grinder  901  (being a grinder that is either internal or external to an espresso making machine), an espresso making machine  902  and a personal preferably wireless communications device  903  such as a smart phone, personal computer, tablet, pad or the like. The wireless communication between the aforementioned devices  100 ,  901 ,  902 ,  903  allow for a wide range of benefits and functionality including individually, and in any practical combination, the following examples. 
         [0051]    With reference to the example of  FIG. 9 , wherein the coffee grinder  901  and coffee machine  902  are separate (or  FIG. 10  when the grinder is integrated with the coffee machine and optionally shares its controller), communication between the coffee grinder  901  and coffee machine  902  can enable wireless or hard wired communication of data signals and command signals between the coffee grinder  901  and the coffee machine  902 . User inputs or commands relating to the grind size and duration may be provided to the coffee grinder&#39;s controller either from the coffee grinder&#39;s user interface  904  or from the personal communication device  903 . These user inputs are used to operate a grind adjust position motor tool that raises and lowers a burr in the grinder&#39;s grind head  1002  and thus alter the size of the grinds produced by the grinder  901 . In some embodiments, the actual position of the burrs is detected by a grind adjust position sensor  1003 . Data from the grind adjust position sensor is provided to either the coffee grinder&#39;s controller  903  ( FIG. 9 ) or a central controller  1004  ( FIG. 10 ). In this way, data relating to the user&#39;s grind selection, the actual position of the adjustable burrs and the grind duration can be broadcast by the grinder  901  and, for example, logged by the communication device  903  or used by the coffee machine&#39;s controller  905  wirelessly via the coffee machine&#39;s transmitter and receiver  906  and controller  905 , or hard wired per  FIG. 10 ). This information is used by the coffee machine&#39;s controller  905 ,  1004  to control aspects of the brewing process such as water temperature, brew duration, brew water press re profile etc. These same parameters can also be controlled by corresponding user inputs originating in the communications device  903 . Thus, the communication device  903  can transmit commands to alter the functionality or operation parameters of the coffee machine  902 , the grinder  901  or both of these  901 ,  902 . 
         [0052]    It will be appreciated that data from the portafilter  100  regarding head temperature and compartment volume may be provided wirelessly to the coffee grinder  901  so that it can be used by the grinder&#39;s controller  903  to adjust the delivery volume of ground coffee. Data from the portafilter  100  can also be wirelessly transmitted to the coffee machine  902  so that the device&#39;s controller  905 ,  1004  can adjust the volume of water delivered to the portafilter. The data transmitted b the portafilter  100  can also be transmitted to the communications device  903  where it can be logged or recorded for future use. 
         [0053]    The network arrangement described above can be used in the following ways. For example, a skilled operator could program brew parameters such as brew temperature, extraction time, grind volume, tamping pressure via a software program installed on the communications device  903 . These parameters can then be uploaded or transmitted to the coffee machine  902  and grinder  901  whereby control program les associates with the appropriate controllers  903 ,  905 ,  1004  will execute the selected parameters for the purpose of replicating the operator&#39;s selected beverage. In another example, the grinder  901  or coffee machine  902  can transmit or download data to the communications device  903  for the purpose of the diagnosis of a problem or potential problem by the user or a service technician. The communications device  903  can accordingly provide a graphic display that relates to the In diagnostic data or provide advice in the form of text or images that relates to solutions to the diagnostic or the problem suggestion by the diagnostic data. In another example, data from all of or any of the portafilter  100 , coffee grinder  901  or coffee machine  902  can be transmitted to and collected by the communications device  903  and logged or recorded for future use. This would allow a user to replicate a particular brew temperature, extraction volume, extraction pressure profile and other parameters once off, repeatedly, or as a data package that can be shared among different users. 
         [0054]    In other examples, and as suggested by  FIG. 10 , a coffee machine  902  with (in this example) an integral or built-in coffee grinder  901  includes a tamping system such as a motorised tamping auger  1005 . The tamping system  1005  further comprises a DC auger motor  1006  that is controlled by the device&#39;s processor  1004 . The motor  1006  drives a rotating auger head  1007  through an adjustable slip clutch  1008  that is associated with a torque sensor  1009 . Ground coffee delivered by the burr grinder  1002  enters the auger head  1007  through a delivery chute  1010 . The coffee machine  902  further comprises a user interface ion that communicates with the processor and through which user inputs, commands or preferences can be expressed to the processor inputs  1012 . Other inputs to the processor include signals relating to the output of the torque sensor  1009 , the flow rate indicated by the flow meter  1013  that is in-line with the high pressure water deliver pump  1014 , an in-line pressure sensor  1015  that is in-line between the high pressure pump  1014  and the brew water boiler  1016  and the output of the grind adjust position sensor  1003 . Utilising these inputs, the controller  1004  is able to exercise control over the grind adjust position motor  1001 , the In grinder motor  1017 , the auger motor  1006 , both the high pressure brew water delivery pump  1014  and the lower pressure steam water delivery pump  1018 , the heating element  1019  of the steam boiler  1020 , the heating element  1021  of the brew water boiler  1022 , the discharge solenoid  1023  that controls the output to the group head  1024  and the graphic display  1025 . In this way, the is processor  1004  can use feedback from the flow meter  1013 , the pressure sensor  1014 , the grind adjust position sensor  1003 , the tamp torque sensor  1009  and the extraction tune to calculate an ideal grind size setting and to regulate the grind, adjust motor  1001  accordingly. The processor  1004  uses feedback from the flow meter  1013 , the pressure sensor  1015 , the grind adjust position sensor  1003 , the tamp torque sensor  1009  and the extraction time to calculate au ideal torque tamp setting and thereby regulate the action of the auger motor  1006  to deliver the calculated torque tamp setting. For example, if a previous extraction was too fast, the processor can reduce the grind size by adjusting the grind adjust motor  1001  and thereby the grind size to make the grind smaller and thereby slow the extraction process. If a previous extraction was too slow, then the grind size can be made larger by controlling the grind size adjust motor  1001  in conjunction with a monitoring of same from the grind adjust position sensor  1003 . Similarly, the previous extraction was too fast, the tamp pressure can be increased by changing the target or threshold resistance as determined by the torque sensor  1009 . Similarly, the previous extraction was too slow, then the tamp pressure can be decreased and the grinder motor will stop at a lower torque resistance as determined by the torque sensor  1009 . 
         [0055]    In another embodiment where no grind size adjust motor  1001  is utilised, the processor can prompt the user using the display  1025  or with the is emission of an audio tone  1026  to adjust the grind size manually, for example, from the user interface  1011 . 
         [0056]    Thus, the processor  1004  is able to receive signals from various sensors and calculate target parameters for various machine functions including grind size and tamp pressure and then execute those parameters, for example by is automatically adjusting grind size or tamp pressure using processor controlled motors  1001 ,  1006  and appropriate feedback devices  1003 ,  1009 . 
         [0057]    Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. 
         [0058]    As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. 
         [0059]    Reference throughout this specification to “one embodiment” or “an embodiment” or “example” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 
         [0060]    Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Any claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. 
         [0061]    Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining” or the like, refer to the action and/or processes of a microprocessor, controller computer or computing system, or similar electronic computing device, that manipulates and/or transforms data. 
         [0062]    Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. 
         [0063]    Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. 
         [0064]    While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope or spirit of the invention.