P100101 1 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Coffee tamping apparatus The following statement is a full description of this invention, including the best method of performing it known to us: 2 Coffee tamping apparatus Field of the invention This invention relates to a coffee tamping apparatus, and in particular to a coffee grinding and tamping apparatus. 5 Background of the invention With the growing demand for high quality espresso coffee, espresso machines have become increasingly sophisticated. Various types of fully programmable machines are available, in which grinding, tamping and brewing of the coffee is performed automatically, as is a milk frothing function if required. A drawback of machines of this type is that the programmable [0 functions are generally pre-set and limited, and whilst such machines have the advantage of being operable by unskilled users, it is widely accepted that a more manually intensive machine in the hands of a skilled user or barista produces a superior cup of coffee. Most if not all manual machines do not include a built-in grinding or tamping function. Rather, coffee beans are separately ground using a standalone grinder and are manually L5 dispensed into a filter in a filter holder. Dosage is either manually judged or based on an imprecise measurement like grinding time. Thereafter, the dosage is manually tamped using a handheld coffee tamper or puck and the filter holder is engaged with the group head, typically via a group head bayonet-type coupling, in preparation for brewing. In addition to the quality of the coffee beans, critical to the quality of the brewed espresso 20 coffee is the correct fineness of the grind, the correct dosage and the correct degree of tamping. Water quality and hot water pressure are further factors. Generally, it takes a skilled barista to effectively manage these variables and produce a consistently good shot of espresso. Furthermore, a manually intensive process is generally a lot messier than an automated one, in particular where ground coffee is being manually dispensed and tamped. 25 It is an object of an aspect of the invention to provide a coffee tamping apparatus which avoids the mess and degree of judgement associated with a manual tamp or puck.
3 Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. 5 Summary of the invention According to a first aspect of the invention there is provided a coffee tamping apparatus for tamping coffee grounds, the tamping apparatus comprising: a pre-compaction chamber for receiving ground coffee via a delivery path; a filter container engageable with a lower opening in the chamber for receiving ground 0 coffee from the pre-compaction chamber; a tamping mechanism arranged to tamp a predetermined quantity of ground coffee into the container; dosage sensing means arranged to detect that the tamping mechanism has reached a tamping compression height once the predetermined quantity of ground coffee has been fed into 15 the container, and to initiate a tamping mechanism stop sequence once the tamping mechanism has reached the tamping compression height; and adjustment means for adjusting the tamping compression height of the dosage sensing means such that the predetermined quantity of ground coffee to be fed into the container prior to initiation of the tamping mechanism stop sequence is manually selectable, the adjustment means 20 comprising a manually-adjustable interface extending from a housing of the coffee tamping apparatus. In a preferred form of the invention the apparatus comprises a display for displaying at least a parameter or reading associated with the adjustment means. Preferably, the tamping mechanism includes a rotary tamp which elevates in response to 25 ground coffee being fed through the tamp, the dosage sensing means including a first sensor which is responsive to the tamp being elevated a preselected distance, wherein the adjustment means is configured to adjust the tamping compression height by adjusting the elevation of the first sensor.
4 The tamping mechanism may further include a biasing means for biasing the rotary tamp downwardly into tamping contact with the ground coffee as it accumulates in the filter container. Conveniently, the coffee tamping apparatus further includes a coffee grinding sub assembly including a hopper for coffee beans, a grinding mechanism for grinding the coffee 5 beans, and grind adjustment means for adjusting the fineness of the ground coffee, the tamping apparatus further comprising an exit chute defining the delivery path for delivering ground coffee from downstream of the grinding mechanism to the pre-compaction chamber. The tamping mechanism is preferably driven by a tamping motor, and the grinding mechanism is preferably driven by a separate grinding motor. 10 Both the grinding and tamping motors typically drive the tamping and grinding mechanisms via drive trains in the form of drive belts. Alternatively, the drive trains may be gear-based or there may be a direct drive arrangement. Preferably the tamping mechanism includes a rotary tamping augur carried on a shaft, the shaft being capable of both axial and rotational movement, and including a drive coupling for 15 coupling the shaft to the drive train, the drive coupling being configured to transfer rotary movement to the shaft and to simultaneously allow axial movement of the shaft, typically via at least one and preferably three coupling pins. The biasing means is preferably a compression spring located in a spring mount which is carried on a bearing, the compression spring acting between the drive coupling and the bearing. 20 Advantageously the tamping compression height adjustment means comprises a manually operable adjustment knob or dial and a rotary to linear converter for converting rotational movement of the dial to linear movement of the first sensor. The rotary to linear converter includes a movement sensor for generating a signal which is fed to the microprocessor which in turn generates a display signal to display the reading 25 associated with the tamping compression height adjustment means, the reading being representative of the extent of rotation of the dial.
5 The rotary to linear converter may include a gearing arrangement which terminates in a pinion which drives a rack on which the first sensor is carried. The first sensor is conveniently a micro-switch having a contact which is activated by an axially movable switching land carried on the tamping mechanism. As a further aspect of the invention there is provided a coffee tamping apparatus for tamping coffee grounds, the tamping apparatus comprising filter holder sensing means for sensing when the filter holder is engaged with the lower opening, the filter holder sensing means being configured to activate the tamping mechanism in response to said engagement. Preferably the filter holder sensing means is also configured to activate the grinding mechanism in response to said engagement. Conveniently the tamping apparatus includes a ground coffee storage container which is engageable with the lower opening in the chamber, and container sensing means for sensing when the coffee storage container is engaged with the lower opening, the container sensing means being configured to activate the grinding mechanism but not the tamping mechanism in response to said engagement. The lower opening in the chamber preferably includes coupling means which are differently configured to triggereither the container sensing means or the filter holder sensing means in response to engagement of the container or filter holder respectively. The coupling means may be in the form of bayonet lugs which are configured or positioned differently between the filter holder and the container, thus triggering separate sensing means. Also described is a coffee tamping apparatus for tamping coffee grounds, the tamping apparatus comprising: a pre-compaction chamber for receiving ground coffee via a delivery path; a container engageable with a lower opening in the chamber for receiving ground coffee from the pre-compaction chamber; a tamping mechanism arranged to tamp a predetermined quantity of ground coffee into the container; 1001242011 6 a first dosage sensing means arranged to deactivate the tamping mechanism once a predetermined quantity of ground coffee has been fed into the container; wherein, the tamping mechanism includes a rotary tamp which elevates in response to ground coffee being fed through the tamp, the first dosage sensing means including a first sensor 5 which is responsive to the tamp being elevated a first predetermined distance. In one form, the tamping mechanism may further include a biasing means for biasing the rotary tamp downwardly into tamping contact with the ground coffee as it accumulates in the container. The tamping mechanism may include a rotary tamping augur carried on a shaft, the shaft 10 being capable of both axial and rotational movement, and including a drive coupling for coupling the shaft to the drive train, the drive coupling being configured to transfer rotary movement to the shaft and to simultaneously allow axial movement of the shaft. In one form, the container may be a filter container or a ground coffee storage container. Preferably, the apparatus further includes a container sensing means for sensing engagement of a [5 filter container or a ground coffee storage container. In one form, the apparatus further comprises a second dosage sensing means arranged to deactivate the tamping mechanism once a second predetermined quantity of ground coffee has been fed into the container, the second dosage sensing means including a second sensor which is responsive to the tamp being elevated to a second predetermined distance, wherein the second 20 predetermined distance is greater than the first predetermined distance. Preferably, the first dosage sensing means is deactivated, and the second dosage sensing means is activated when a filter container is sensed by the container sensing means. In another aspect of the invention, there is provided a method of tamping coffee grounds from a tamping apparatus to a container engaged with the tamping apparatus, including the steps 25 of: selecting a desired dosage by adjusting a tamping compression height for a dosage sensing means based on a selected dosage, the adjustment means comprising a manually adjustable interface extending from a housing of the coffee tamping apparatus; 7 activating the tamping apparatus, whereby a tamping mechanism delivers and tamps ground coffee into the container; and initiating a tamping mechanism stop sequence when a quantity of ground coffee tamped in the container reaches the tamping compression height sensed by the dosage sensing means. 5 As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps. Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way 10 of example and with reference to the accompanying drawings. Brief description of the drawings Figure 1 shows a perspective view of a coffee grinding and tamping apparatus of the invention; Figure 2 shows a perspective view of the inner workings of the grinding and tamping 15 apparatus of Figure 1; Figure 3 shows a top plan view of the inner workings of Figure 2; Figure 4 shows a cross-sectional side view of the coffee grinding and tamping apparatus of Figure 1; 8 Figure 5 shows a perspective cutaway sectional view of those components of the apparatus defining the flow path of ground coffee from a grinder to a filter holder; Figure 6A shows a partly cutaway perspective view of a detail of a pre-compaction chamber; 5 Figure 6B shows a partly cutaway perspective view of a detail of the pre-compaction chamber of Figure 6A with a filter holder in position; Figure 6C shows a perspective view of the filter holder coupled to the pre-compaction chamber, showing the lead-in chamfer of the sprung pin; Figure 6D shows an alternative perspective view of the grinding and tamping apparatus [0 of Figure 2, illustrating a second micro-switch; Figure 6E shows a perspective view of a beaker container for holding ground coffee; Figure 6F shows a side view of the beaker of Figure 6E coupled to the pre-compaction chamber, illustrating an activated micro-switch; Figure 6G shows a perspective view of the beaker coupled to the pre-compaction [5 chamber of Figure 6F, illustrating an inactivated second micro-switch; Figure 7 shows a top perspective view of part of the tamping sub-assembly; Figure 8A shows a cross-sectional side view of the tamping sub-assembly of Figure 7; Figure 8B shows a perspective view of the augur; Figure 9 shows a top perspective view of the tamping sub-assembly including a height 20 adjustment mechanism; Figure 10 shows a cross-sectional side view of the tamping sub-assembly of Figure 9 with drive components; Figure 11 shows a top perspective view of the tamping sub-assembly showing part of a drive shaft coupling; 9 Figure 12 shows a cross-sectional side view of the tamping mechanism sub-assembly with the height adjustment mechanism in a raised position; Figure 13 shows the sub-assembly of Figure 12 with the height adjustment mechanism in a median position; 5 Figure 14 shows a perspective view of part of the tamping mechanism sub-assembly, illustrating a micro-switch arrangement for the tamping mechanism in the "beaker mode"; Figure 15 shows a block diagram representing the circuit schematic of the tamping and grinding apparatus; Figure 16 shows a flow diagram of the logic for the microprocessor; t0 Figure 17 shows a partly cutaway perspective view of an alternative embodiment of the tamping mechanism sub-assembly, with the tamper raised; and Figure 18 shows a partly cutaway perspective view of the tamping mechanism sub assembly of Figure 17, with the tamper lowered. Detailed description of the embodiments .5 It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention. Referring first to Figure 1, a tamping and grinding apparatus 10 of the invention 20 comprises a housing 12 upon which is mounted a coffee bean hopper 14. A grind adjustment dial 16 extends between the hopper 14 and the housing 12, and forms part of a coffee grinding sub assembly 18 illustrated in Figure 4. A front face 12A of the housing is formed with an LCD screen 20 for displaying various parameters and readings, including compression height, grind setting and the presence or otherwise of a filter handle or canister. The grind adjustment dial 16 25 is fitted with a sensor (not shown) which is connected to a microprocessor, which in turn generates a display signal for display on the screen 20 representative of the fineness of the grind.
10 A compression height dial 22 extends from one side of the housing, and is used to manually adjust the compression height of ground coffee within the grinding and tamping apparatus. A filter handle 24 extends from a filter holder 26 which is located within a C-shaped recess 28 defined in the housing. 5 Referring now to Figures 2 and 3, the grinding sub-assembly 18 is driven by a grinding motor 30 via a belt drive 32 extending around a drive wheel or pulley 34 from which a drive shaft 36 extends. A tamping sub-assembly 38 is driven by a separate tamping motor 40 via a drive belt 42 which extends around a drive wheel or pulley 44. The other end of the drive belt 42 extends around a drive shaft 46 which extends axially from the motor 40. 10 Grinding sub-assembly Referring now to Figure 4, the grinding sub-assembly 18 includes the grinder drive shaft 36. This drives a lower conical burr (not shown) which is fixed to the drive shaft and which rotates at about 500rpm. An upper conical burr 50 is stationary, and the grind adjustment dial 16 is operable to adjust the distance between the upper and lower conical burrs thereby to adjust the 15 fineness of the grind. A load sensor (not shown) on the grinding motor 30 senses when there is no grinding load, which corresponds to the hopper 14 being empty. The load sensor is also connected to or communicates with the microprocessor, which activates a beeper in response to a "no load" condition, indicating that the hopper needs to be replenished. The belt-driven motors 30 and 40 are generally smaller and tend to operate more smoothly than direct drive motors. 20 Further, because of the pulley arrangement, no other gearing down arrangement is necessary to lower the speed of the motors. Referring in addition to Figure 5, it can clearly be seen how ground coffee exiting the grinding burrs is deposited in an upper chamber 52. It exits the upper chamber 52 in the direction of arrow 55 via an exit chute 54 which communicates with an entry chute 56 forming part of a 25 pre-compaction chamber 58. The pre-compaction chamber 58 is formed with an annular bayonet receiving recess 60 towards its base for receiving the filter holder 26 which is formed with a complemental bayonet fitting, including bayonet lugs 88 (Figure 6B). The filter holder carries a filter basket 62 for receiving compacted or tamped coffee grounds. As can clearly be seen in Figure 6B, the filter basket has an outer peripheral lip 64 which extends over the upper rim 66 of 30 the filter holder. An annular elastomeric seal 68 is located in a corresponding annular recess 70 11 to provide a wipe seal between the filter basket 62 and the pre-compaction chamber. This minimises or reduces "spill-over" of grounds resulting in a clean filter edge after the grinding and tamping process. As a result, the integrity of the corresponding seal in the group head of the espresso machine is not compromised with stray grounds when the filter holder is rotated into position. Filter holder sensing switch arrangement Referring now to Figures 6A to 6C, a sprung pin 72 having a lead in chamfer 73 is shown biased downwardly by means of a coil spring 74 into the previously described bayonet recess 60. A micro-switch 78 is screw mounted to a side wall of the pre-compaction chamber 58 via a mounting block 80, and includes a sprung contact 82 which is positioned to be activated by an arm 84 extending laterally from a base of the pin 72. As is clear from Figure 6B, when the filter holder 26 is rotated into engagement with the bayonet recess, the bayonet lug 88 pushes the pin upwards which in turn causes the actuating arm 84 to close the contact 82. Closure of the micro-switch, which corresponds to full insertion of the filter holder, allows both the grinding motor 30 and the tamping motor 40 to be turned on via a button. An override function is also provided in the circuitry and is operable via a switch/touch to override the manual turn-on function. The handle is now fully supported by the bayonet corresponding to no hands operation. The default logic will accordingly require the user to push a button -the override will be the automatic insert handle and machine turns on. In one embodiment of the invention, the filter holder may be replaced by a container or hopper, such as a beaker 89 for storing ground coffee. This container or hopper 89 may be configured with a flange 89A, 89B to actuate the micro-switch 78 via the pin 72, as shown in Figure 6F, which in turn is arranged only to activate the grinder motor. An additional micro switch 78A and pin arrangement may be provided where the filter holder 26 (as shown in Figure 6D), but not any hopper or container (as shown in Figure 6G), is able to actuate via suitable profiling at the bayonet-fitting interface 88A. This second micro-switch 78A is arranged separately to activate the tamping motor. As a result, if a container or hopper is fitted in position, as illustrated in Figures 6F and 6G, only the grinder is activated, whilst if the filter holder is located in position in the manner indicated in Figure 6B, both micro switches are activated, which serves to activate both the grinder and tamper motors. 1001242011 12 Alternatively, the microprocessor in detecting activation of one micro-switch 78, would perform a sequence of functions suitable for filling, and optionally light tamping, of the container or hopper 89. If the microprocessor detects activation of both micro-switch 78 and 78A, an alternative sequence of functions for filling and tamping the filter holder 26 is 5 performed. In addition, when the container or hopper 89 is filled, the microprocessor may rotate the augur 92 several revolutions to "clear" the grounds from the pre-compaction chamber 58 prior to completing the filling sequence. Tamping sub-assembly Referring now to Figures 7, 8A and 10, part of the tamping sub-assembly 38 with filter 10 holder 26 is shown. A rotary shaft 90 carries a tamping head or augur 92 which comprises two 180" helical flights 92A and 92B, as best shown in Figure 8B. As can clearly be seen in Figure 10, the shaft extends through a Teflon bush 94 of top hat section. The bush 94 extends through a central aperture 96 defined in a top cover 98 of the pre-compaction chamber, and is held in position by means of a circlip 100. A sealing gland 102 is sandwiched between the base of the [5 bush 94 and a cup-shaped seal mount 104. A drive shaft coupling 108 similarly of top hat section is formed with a lowermost flange 110, the upper surface of which provides a horizontal land 112. The drive shaft coupling 108 is provided with a central aperture 112 through which the shaft 90 extends, and a grub screw 113 extends through the drive shaft coupling and bears against the drive shaft to lock the coupling in position relative to the shaft. The drive shaft coupling is also 20 formed with three apertures 114, which are visible in Figure 11. The three apertures receive three shaft pins, one of which is shown at 116 in Figure 10. These shaft pins extend from a hub portion 118 of drive wheel 44. The drive shaft coupling 108 is formed with an upper annular groove 120 which receives a compression spring 122. The upper side of a compression spring 122 locates within an annular 25 groove 124 defined within a compression spring mount 126 which is clipped into a bearing 128. The bearing is in turn fitted within a circular aperture 130 defined in an upper housing 132 of the sub-assembly, and held in position by means of a retaining ring 133. The compression spring 122 acts to bias the drive shaft assembly, including the drive shaft coupling 108, the drive shaft 90 and the tamping augur 92 downwards at a suitable tamping pressure.
13 It will be appreciated that the drive shaft assembly including the drive shaft coupling 108 is configured to move axially relative to the bush 94 and the hub 118, with the drive shaft pins 116 being located within the three drive shaft apertures 114 and allowing the drive shaft assembly to move smoothly up and down as it is rotating. 5 As the drive shaft assembly rotates and the coffee grounds are fed into the pre compaction chamber 58 via the chute 56, the grounds migrate down the helical flights 92A and 92B of the tamping augur 92 and are then incrementally compacted or tamped between the lower surfaces of the tamping augur and the filter basket 62. As more grounds accumulate beneath the tamping augur 92, the augur is slowly pushed up against the downward bias of the compression [0 spring 122. A desired tamping compression height is shown in broken outline at 134 in Figure 4. The manner in which this compression height may be adjusted will now be described with reference to Figures 7 to 12. A further micro-switch 135 is shown mounted on a moulding 136 which carries a rack formation 138. The moulding 136 is in turn slidably mounted within a sub-housing 140 which is t5 screwed onto an opening in the upper housing 132. The sub-housing 140 is formed with a cover plate 142 having a rectangular opening through which a pinion 144 extends. The pinion is formed with a fine set of teeth 146 which intermesh with the rack 138. It can clearly be seen from Figure 8A how rotation of the pinion 144 will cause the moulding 136 to move vertically up and down, which in turn causes vertical adjustment of the micro-switch 135, typically 20 allowing for 5-10mm of vertical movement. A roller contact 148 extends from the micro-switch 135. The roller contact is arranged to make rolling contact with the land 112 on the drive shaft coupling as it rotates and moves upwardly in response to upward movement of the tamping mechanism. Closure of the contact via the upwardly moving land causes the tamping motor 40 to turn off via the microprocessor. As a result, if the micro-switch 135 is moved to the uppermost 25 position as illustrated in Figure 12, the tamping compression height is raised to a maximum level. In contrast, if the micro-switch 135 is lowered to say the Figure 13 position, then the tamping compression height is lowered by the same amount. In this manner, the volume of coffee within the filter holder can be manually adjusted. Referring now to Figure 9, the height adjustment mechanism 150 is shown in more detail. 30 A shaft 151 extends from the compression height dial 22, and carries a small cog 152 which in turn drives a larger gear 154. A smaller cog 156 is mounted to rotate coaxially with the larger 14 gear 154, and in turn drives the cog or pinion 144 which controls vertical movement of the rack 138. At the end of the shaft 151 is a trim potentiometer 158 which is mounted on a PCB 160. The gears are used to reduce 2700 of rotation to 30* of rotation. The down-gearing arrangement is used so that the trim potentiometer can function accurately, in that it has relatively low 5 sensitivity which requires large rotational movements (ie 2700) to register change. The analogue signal derived from the trim potentiometer is converted at the microprocessor to a digital signal which is then displayed on the LCD screen 20 to communicate the compression height. A tamping arrangement for lightly tamping coffee grounds when filling a container or hopper 89 will now be described with reference to Figure 14. When filling the container 89 [0 (herein described as "beaker mode"), it may be advantageous to impart a light tamp to ensure complete filling of the container 89. A further micro-switch 161, is fixed relative to the top cover 98 of the pre-compaction chamber 58, and is activated by the lowermost flange 110, when the drive shaft coupling 108 and connected augur 92 is at the lower most position relative to the pre-compaction chamber 58. When filling the container 89, it may be advantageous to turn the t5 augur 92, to assist in distribution of the coffee grounds into the container as well as providing a light tamper. When initially filing the container, the augur 92 and the drive shaft coupling will be at the lowermost position, thereby causing the flange 110 to activate the micro-switch 161. When the container is filled, or nearly filled, the auger 92 would start to impart a tamper force on the coffee grounds. In turn, the coffee grounds in the container would impart an opposing force !0 against the rotating augur 92, thereby shifting the augur 92 and lowermost flange 110 away from the micro-switch 161, thereby deactivating it. Once the micro-switch 161 is deactivated, the filling sequence can be completed and the grinder and augur can be stopped. This arrangement allows a light tamper on the coffee grounds, compared to the tamping described above for the filter holder 26. 25 In further variations, more micro-switches may be incorporated at different levels to sense additional positions of the drive shaft coupling 108. This may be incorporated to assist in sensing various level of tamping. Circuit Schematic Referring to Figure 15, the circuit schematic 200 for controlling the tamping and grinding 30 apparatus 10 is shown. The user inputs desired activation settings 201 to the controller, such as 15 start and stop, as well as setting manual and automatic modes. The controller has input sensors for the tamper compression height 205, grind setting height 207, as well as a current sensor 209 to measure load on the grinder motor. The controller, provides actuation signals to the tamper motor 211 and grind motor 213, as provided by the control logic, and displays information to the 5 operator on the LCD or LED display 215. In one embodiment, the controller is microprocessor based. Control Logic The control logic 300 will now be described with reference to Figure 16. The apparatus is turned on 301 and enters standby mode 303. In this mode, the apparatus detects and displays 10 the settings 305 of the apparatus, including tamping compression height, grind settings, manual/automatic mode of operation, and whether a group handle (filter holder) or beaker (container) is coupled to the apparatus. These settings 305 may directly or indirectly reflect a selected dosage of ground coffee. These settings, may be adjusted by the user whilst the apparatus is in the standby mode 303. The machine will remain in standby mode 303 until either t5 the filter holder 307 or the beaker 309 is detected by the micro-switches. In the standby mode 303, the apparatus detects if the filter (handle) is present at step 307. If the filter (handle) is detected, by activation of micro-switches 78 and 78A, the apparatus will once again detect and display the grinder status 311, including displaying that a filter is present. The apparatus will then determine if the apparatus is in an "automatic" mode at step 315. If in 20 an automatic mode, the apparatus will automatically commence the grinding and tamping step 317 by activating the respective motors. If not in an automatic mode, i.e. in a "manual" mode, the apparatus will wait for the user to push the start button at step 313, and once the start button is pushed, will commence the grinding and tamping 317 step. Whilst grinding and tamping, the apparatus will continue to detect and display the grinder status 318. 25 When grinding and tamping 317 the apparatus will monitor whether a stop button is activated at step 319. If the stop button is activated, the grinder proceeds to the stop sequence 323, whereby the grinder motor stops and the tamper motor will run for another 5 seconds to complete tamping before the apparatus returns to the standby mode 303. If the stop button is not activated, the grinder will continue grinding and tamping 317, 30 and enter a filled filter detection step 320, to determine whether the coffee grounds have filled up 16 the filter. This is achieved through micro-switch 135, which will activate when the coffee grounds have filled up to cause the tamper to rise to the desired tamping compression height. If the apparatus detects the coffee grounds have filled up, the apparatus proceeds to the stop sequence 323 as described above. Otherwise, the apparatus will continue grinding and tamping 5 317. In the standby mode 303, if the filter handle is not detected 307, the apparatus will detect if a beaker is present at beaker detection step 309, by sensing if micro-switch 78, by itself, is activated. If no beaker is present, the apparatus will remain in the standby mode 303. If a beaker is detected, the apparatus further detects and displays the grinder status 311, including 10 displaying that a beaker is present. The apparatus will then determine if the apparatus is in an "automatic" mode at step 315. If in an automatic mode, the apparatus will automatically commence the grinding and tamping step 317 by activating the respective motors. If not in an automatic mode, i.e. in a "manual" mode, the apparatus will wait for the user to push the start button at step 313, and once the start 15 button is pushed, will commence the grinding and tamping step 317. During grinding and tamping, the apparatus will continue to detect and display the grinder status 318. During grinding and tamping 317 the apparatus will also detect whether a stop button is activated at step 319. If the stop button is activated, the grinder proceeds to a stop sequence 337, whereby both the grinder motor and tamper motor stops and the apparatus returns to the standby 20 mode 303. If the stop button is not activated, the grinder will continue the grinding and tamping step 317, and proceed to a filled beaker detection step 334, to determine whether the coffee grounds have filled up the beaker. This is achieved through micro-switch 161, which becomes deactivated when the beaker is full or nearly full. If the apparatus detects the coffee grounds have 25 filled up, the apparatus proceeds to the stop sequence 337 as described above. Otherwise, the apparatus will continue grinding and tamping 317. Alternative embodiment of tamping sub-assembly Referring to Figures 17 and 18, there is provided an alternative tamper assembly 400. The tamper assembly 400 comprises a shaft 401, having screw threading 403 for engagement 17 with the top cover 409 of the pre-compaction chamber 458. A rotatable coupling 405, couples the tamper 407 to the shaft 401, thereby allowing the shaft to rotate 401 relative to the tamper 407. The tamper 407, is provided with a seal 409 to seal against the walls of the pre-compaction chamber 458. 5 To fill coffee grounds into the filter holder 26, coffee grounds are introduced into the pre compaction chamber 458 via chute 56. The conical surface of the pre-compaction chamber 458 allow the coffee grounds to pass around the raised tamper, as shown in Figure 17, and into the filter holder 26. Once an appropriate amount of coffee grounds are introduced, the tamper 407 is lowered to tamper the coffee grounds. This is achieved by driving the shaft 401, whereby the 10 threading 403 drives the shaft 401 axially towards the filter holder 26, as shown in Figure 18. This forces the tamper 407 towards the filter holder. As the coupling 405 is rotatable, this, in combination with friction against the coffee grounds and neck of the pre-compaction chamber 458, reduces or prevents the tamper 407 from rotating during tamping. In one embodiment the coupling 405 may include a universal joint. [5 This may allow a degree of angular displacement of the tamper 407. The tamper assembly 400 may be arranged with one or more sensors to determine height and/or pressure, and consequently compaction of the coffee grounds. This may include an arrangement of micro-switches to determine the height of the tamper 407. In one form, the micro-switch(es) may be fixed relative to the pre-compaction chamber 458 and/or filter holder 20 26. In another form, the micro-switch(es) are height adjustable relative to the pre-compaction chamber 458 and/or filter holder 26, thereby allowing adjustment of tamper height, and/or pressure.