AU2014203747A1 - Grinder - Google Patents

Abstract

A grinder including a first grinding element having a first grinding surface; a second grinding element having a second grinding surface, wherein at least one portion of the first grinding surface opposes at least one portion of the second grinding surface, the opposing portions 5 separated by a separation distance, and wherein the first and second grinding surfaces are movable relative to one another to grind a product in between the opposing portions, an adjustment means for selectively adjusting the separation distance; and a user control operatively coupled with the adjustment means, wherein the user control has restricted adjustment of the separation distance within a selectively defined range of distances, and wherein the user control 10 and/or adjustment means can be calibrated to select the defined range of distances. -7 8e21 51 51 610 Fiaure 5a Fiauirp Sh

Description

1 GRINDER Field of the invention The present disclosure relates to grinders of the type having an adjustable grind setting to change the coarseness of the ground product. The present disclosure has particular application 5 for grinding products for human consumption, such as coffee beans during preparation of coffee. Background of the invention It is often desirable to grind consumable products during preparation of food and beverages. Grinding consumable products reduces the size of the product, so that the ground product is suitable for incorporation into the recipe for the food or beverage. 10 One well known application for grinders is to grind roasted coffee beans, whereby the ground coffee is then used to prepare coffee (beverage) using espresso machines, drip filtering, or with a plunger. It is known that these different methods of preparing coffee may require different coarseness or fineness of the ground coffee (known as "grind setting") to achieve optimal flavour. Furthermore, different types of coffee beans, different machines, and even 15 different individual tastes of the consumer can dictate changes in the grind setting. One type of coffee grinder known as a 'conical burr grinder' includes a stationary annular burr that receives a rotating conical burr. The burrs have surfaces that oppose the other burr, and rotation of the conical burr grinds coffee beans between them. The separation between these opposing surfaces is a major factor that dictates the coarseness or fineness of the ground coffee. 20 Some known coffee grinders include controls that allow the user to adjust the separation between these opposing surfaces thereby allowing the user to change the grind setting. In some grinders, the adjustment of this separation is between 0 and 1mm of vertical movement between the burrs. However, use of the coffee grinder over time can cause the burrs to wear, which consequently changes the separation between the opposing surfaces. Furthermore, the lower 25 burr or upper burr may "settle" (e.g. during a run-in period) after which the separation distance is unpredictable. Thus a user may set the control, such as a dial, at a position for a particular grind setting and find that over time, as the burrs wear out, the coarseness of the ground coffee increases.

2 One object of the present disclosure is to provide a grinder that may reduce or provide correction to the effects of the burrs wearing out. In some coffee grinders, the ground coffee exits the conical burrs and passes through a chute, and to an opening for dispensing the ground coffee. A stainless steel 'flap' may be 5 positioned in, before or after the chute, whereby the flap closes off the path of the ground coffee to provide back pressure to the ground coffee. This causes the ground coffee to collect upstream of the flow of ground coffee, which encourages the ground coffee to aggregate into larger 'clumps'. The upstream pressure overcomes the mechanical resistance of the flap which moves open to allow the clumps to pass through the chute. The clumps of ground coffee have increased 10 mass compared to ground 'fines', which reduces the effects of static electricity that may attract the coffee grounds. However, prolonged use may cause the stainless steel 'flap' to fatigue or undergo hysteresis to the point where the flap is permanently open. Another object of the present disclosure is to provide a grinder with an improved flap for the chute that reduces or eliminates the disadvantages of known flaps. 15 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. Summary of the invention 20 In a first aspect, the present disclosure provides a grinder including: a first grinding element having a first grinding surface; a second grinding element having a second grinding surface, wherein at least one portion of the first grinding surface opposes at least one portion of the second grinding surface, the opposing portions separated by a separation distance, and wherein the first and second grinding surfaces are movable relative to one another to grind a 25 product in between the opposing portions, an adjustment means for selectively adjusting the separation distance; and a user control operatively coupled with the adjustment means, wherein the user control has restricted adjustment of the separation distance within a selectively defined range of distances, and wherein the user control and/or adjustment means can be calibrated to select the defined range of distances.

3 In one form, the grinder further includes: a first stop means that operatively stops adjustment of the separation distance to a minimum distance, wherein calibration of the user control and/or adjustment means vary the minimum distance in the selected defined range of distances. 5 In one form, the grinder includes a second stop means that operatively stops adjustment of the separation distance to a maximum distance, wherein calibration of the user control and/or adjustment means varies the maximum distance in the selected defined range of distances. In a further form, the first and second stop means limits movement of the user control, thereby restricting adjustment of the separation distance within the defined range of distances. 10 In one form of the grinder, the difference between the minimum distance and the maximum distance is constant. In one form, the grinder is a conical burr grinder, wherein: the at least one portion of the first grinding surface includes a substantially frusto-conical surface facing outwardly, the at least one portion of the second grinding surface includes a substantially frusto-conical surface facing 15 inwardly, the opposing first and second portions are concentric, the second grinding element receives at least part of the first grinding element, wherein the adjustment means operatively provides relative movement of the first and second grinding elements along a common concentric axis to adjust the separation distance between the opposing portions. In a further form, the adjustment means is a screw adjustment rotatable in a first direction 20 to decrease the separation distance between the opposing portions, and rotatable in an opposite second direction to increase the separation distance between the opposing portions. In yet another form, the adjustment means includes: a stationary bracket with a first threaded portion, the stationary bracket positioned at a fixed axial displacement along the concentric axis, an adjustment wheel having a second threaded portion for engagement with the 25 first threaded portion, the adjustment wheel operatively carrying the second grinding element, wherein rotation of the adjustment wheel in the first or second direction displaces the second grinding element along the common concentric axis to adjust the separation distance.

4 In one form, the adjustment wheel and the user control can be coupled together at a plurality of different relative angular displacements to each other. In a further form, the adjustment wheel and the user control each have complementary teeth to allow coupling at different relative angular displacements. 5 In one form of the grinder, the stationary bracket further includes: a first stop surface; and a second stop surface, the user control further includes at least one stop element, wherein the first and second stop surfaces provide limits to the movement of the stop element, such that user control can only adjust the separation distance within the defined range of distances. In one form, the grinder further includes a guide means for allowing the second grinding 10 element to move axially along the common concentric axis, whilst preventing rotation of the second grinding element around the common concentric axis. In one form of the grinder, the stationary bracket is releasable attached to a base of the grinder. In one form, the adjustment means and user control are part of a burr adjustment module, 15 wherein detaching the stationary bracket from the base of the grinder also detaches the burr adjustment module from the base of the grinder. In a further form, the burr adjustment module can be detached and attached to the base of the grinder without disturbing the selection of the user control for a corresponding separation distance. 20 In one form, the burr adjustment module further includes a carrier, wherein the carrier supports the second grinding element, and wherein the carrier is rotatably attached to the adjustment wheel such that the adjustment wheel operatively carries the second grinding element whilst allowing relative rotation between the adjustment wheel and the second grinding element. In another form of the grinder, a hopper container is releasable attached to the burr 25 adjustment module. In a further form, the hopper container is releasably attachable to the carrier. In one form, the grinder further includes a safety arrangement, wherein the safety arrangement prevents operation of the grinder if the hopper container and the burr adjustment module are not correctly assembled with the base of the grinder.

5 In a further form, the safety arrangement includes a safety element passing through the carrier, wherein when the hopper is attached to the carrier, the safety element is displaced to an unlocked position, and wherein when the hopper is detached from the carrier, the first safety element is displaced to a locked position, wherein a detection means is provided in the base of 5 the grinder to detect the displacement of the safety element. In one form of the grinder, at least one of the first or second grinding elements is operatively coupled and rotated by a motor when the grinder is in use. In one form of the grinder, the second grinding element is stationary when the grinder is in use. 10 In one form, the grinder further includes indicia to indicate to the user the selected separation distance within the defined range of distances. In one form, the grinder further includes a detent means operative on the user control or adjustment means, wherein the detent means provide tactile feedback to the user to allow adjustment of the separation distance within the defined range of distances in discrete 15 increments. In another form, the grinder is a flat burr grinder, wherein the first and second grinding elements include respective first and second grinding plates. In another aspect, the present disclosure provides a grinder including: a grinding mechanism for grinding a product to a ground product; a chute for providing a passage for the 20 ground product from the grinding mechanism to an outlet, a flap provided in the chute for applying back pressure to the ground product passing through the chute, wherein the flap is at least partially made of an elastomeric material. In one form, a lower portion of the flap is movable between a closed position and an open position, and the chute includes a lower wall, wherein at the closed position, a plane of the lower 25 portion of the flap converges and meets with a plane of the lower wall. 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.

6 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 of example and with reference to the accompanying drawings. Brief description of the drawings 5 Fig. 1 is a perspective view of a grinder having a base and a hopper; Fig. 2 is a perspective view of the grinder with the hopper removed; Fig. 3a is a perspective view of the grinder with a user control removed, and adjustment means exposed; Fig. 3b is a side view of the grinder in Fig. 3a; 10 Fig. 4a is a perspective view of the grinder with the adjustment means and stationary bracket separated from the base; Fig. 4b is a side view of the grinder in Fig. 4a; Fig. 5a is a perspective view of the grinder with the hopper and burr adjustment module separated from the base; 15 Fig. 5b is a side view of the grinder in Fig. 5a; Fig. 6a is an exploded perspective view of the major components of the burr adjustment module; Fig. 6b is an alternative perspective view of the burr adjustment module in Fig. 6a; Fig. 7a is a perspective view of the stationary bracket and adjustment wheel in threaded 20 engagement; Fig. 7b is an alternative perspective view of the stationary bracket and adjustment wheel in Fig. 7a; Fig. 7c is a top view of the stationary bracket and adjustment wheel in Fig. 7a; Fig. 7d is a cross-section side view of the stationary bracket and adjustment wheel along 25 D-D in Fig. 7c; Fig. 8a is a perspective view of the user control; Fig. 8b is an alternative perspective view of the user control; 7 Fig. 9a is an exploded perspective view of the burr adjustment module showing the detailed components; Fig. 9b is an alternative exploded perspective view of the burr adjustment module in Fig. 9a; 5 Fig. 9c is a side view of the burr adjustment module in Fig. 9a; Fig. 10a is a top view of the grinder showing the user control at a maximum setting for the separation distance in the defined range of distances; Fig. 10b is a top view of the grinder showing the user control at a medium setting for the separation distance in the defined range of distances; 10 Fig. 10c is a top view of the grinder showing the user control at a minimum setting for the separation distance in the defined range of distances; Fig. 1 la is a cross-section side view of the grinder showing the first and second grinding surfaces separated by a relatively large distance to correspond to the maximum setting in Fig. 10a; 15 Fig. 1 lb is a cross-section side view of the grinder showing the first and second grinding surfaces separated by an intermediate distance to correspond to the medium setting in Fig. 10b; Fig. 1 lc is a cross-section side view of the grinder showing the first and second grinding surfaces separated by a relatively small distance to correspond to the minimum setting in Fig. 10C; 20 Fig. 12 is a perspective view of a chute of the grinder; Fig. 13 is a cut-away perspective view of the chute in of Fig. 12 showing a flap; Fig. 14 is a top view of the chute of Fig. 12; Fig. 15 is a sectioned side view of the chute in Fig. 13. Fig. 16a is a sectioned side view of the chute in accordance with another embodiment 25 showing the flap in a closed configuration; Fig. 16b is a sectioned side view of the chute in Fig. 16b showing the flap in a partially open configuration; 8 Fig. 16c is a sectioned side view of the chute in Fig. 16c showing the flap in a substantially open configuration; and Fig. 17 is a perspective view of another embodiment of the flap made of spring wire. 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. A grinder, in the form of a conical burr grinder 1 for grinding coffee beans is shown in 10 Fig. 1. The grinder 1 has a base 3 for housing a motor to drive the grinder and supporting the components of the grinder, and a control dial 5 for activating the motor. A hopper 7 is supported above the base 3 and serves to contain coffee beans for feeding through the grinder. When in use, the motor is activated and the coffee beans are fed from the hopper 7 into the grinding mechanism (discussed below) to produce ground coffee that is dispensed through opening 9. A 15 user control 41 allows the user to adjust the grind setting. Overview of the grinder A grinder 1 in accordance with one embodiment will now be described with reference to Figs. 1 to 5b, which shows the grinder 1 in various states of assembly. The grinder 1 in this embodiment is a conical burr grinder. However, it is to be appreciated aspects of this disclosure 20 may be applied to other types of grinders, such as flat burr grinders. The grinder 1 includes a first grinding element 11, which is substantially conical, and has a first grinding surface 13. A second grinding element 21 has a second grinding surface 23, which in this embodiment is substantially annular to receive at least part of the grinding element. When assembled, as shown in Fig. 1la, at least one portion of the first grinding surface 13 25 opposes at least one portion of the second grinding surface 23, with a separation distance between these opposing portions. When in use, the first grinding element 11 is rotated so that the first and second grinding surfaces 13, 23 move relative to one another to grind a product in between the opposing portions. The separation distance between the opposing portions can be selectively adjusted by an 30 adjustment means 31. The adjustment means 31 in turn is operatively coupled with a user 9 control 41. The user control 41 includes a rotatable ring, with a protrusion 45 for showing the relative orientation of the ring. The user control 41 can be rotated by the user to adjust the separation distance, which in effect provides the user a means to adjust the "grind setting" for the grinder. Figs. 10a to 10c illustrate the user control 41 at various grind settings, with protrusion 5 45 providing visual indicia of the various positions and grind settings of the user control 41. Adjustment of the separation distance by the user control 41 is restricted so that the separation distance is adjustable within a selectively defined range of distances. The user control 41 and/or the adjustment means 31 can be calibrated to select the defined range of distances that the separation distance is restricted to. 10 The opposing portions of the first and second grinding surfaces 13, 23 are concentric and the adjustment means moves the second grinding element relative to the first grinding element along a common concentric axis. The user control 41 and adjustment means 31 are part of a burr adjustment module 51, that is detachable from the base 3 of the grinder 1 as shown in Fig. 5a. 15 Advantageously, calibration of the user control 41 and/or the adjustment means 31 allows the user to set a range of "grind settings" for the grinder 1. Furthermore, this also allows re calibration of the user control 41 and/or adjustment means 31. This is particularly useful when the grinding elements 11, 21 wear out, and the user finds that the coarseness of the ground coffee has increased for the same selected position on the user control 41. 20 Components of the grinder 1 will now be described in detail Burr adjustment module As shown in Figs. 6a and 6b, the burr adjustment module 51 includes three main component groups, the user control 41, a carrier group 81, and a stationary bracket 61. When assembled, the three groups are mounted concentrically. The user control 41 fits over the carrier 25 group 81 and engages the stationary bracket 61. The burr adjustment module houses the second grinding element 21, and includes the adjustment means and user control 41 in a module that can be removed from the base 3 for cleaning. Furthermore, the burr adjustment module 51 provides a mount for the hopper 7.

10 Stationary bracket The stationary bracket 61 mounts directly to the base 3 via a set of radially extending lugs 63. The radially extending lugs form part of a bayonet-type engagement with corresponding slots in the base 3. A slot 65 is provided for receiving a locking member 15 of the base 3, which 5 prevents the stationary bracket 61 from rotating out of engagement with the base 3 unless the locking member 15 is selectively retracted. Around the external periphery of the stationary bracket 61 are vertical ribs 68 for location against an inwardly facing curved surface 106 of the base 3. This assists in positioning the stationary bracket 61, and other components of the burr adjustment module, in particular the 10 second grinding surface 23 concentric with the first grinding surface 13 of the first grinding element 11 of the base 3. The stationary bracket 61 includes a first threaded portion 67, which in this embodiment is in the form of interrupted threads, for engagement with a corresponding threaded portion 85 of the carrier group 81, to form part of the adjustment means 31. In an alternative embodiment, the 15 first threaded portions 67 are continuous threads. A plurality of guide members 69 extend parallel to the common concentric axis, which are received by the carrier (discussed below) to prevent the second grinding element 21 from rotating around the common concentric axis. An arcuate channel 75 is provided in the stationary bracket 61 to receive a stop element 20 44 of the user control 41, as shown in Fig. 6b. A first stop surface 71 and second stop surface 73 is provided in the channel, as shown in Fig. 7c, which limits the movement of the stop element 44 and the user control 41. Thus the first and second stop surfaces 71, 73 provide limits to the stop element 44, such that the user control 41 can only adjust the separation distance within the defined range of distances. 25 Carrier Group Adjustment wheel The carrier group 81 includes an adjustment wheel 83 having a secondary threaded portion 85 for engagement with the first threaded portion 67 of the stationary bracket 71. Rotation of the adjustment wheel 83 relative to the stationary bracket 71 moves the adjustment 30 wheel 83 (and the second grinding element 21 in the carrier group 81) relative to the stationary 11 bracket 71 (and the first grinding element 11 in the base 3). Thus rotation of the adjustment wheel 83 provides adjustment of the separation distance of the grinder 1. A plurality of teeth 87 are provided for coupling with corresponding teeth 43 of the user control 41. The plurality of teeth 87 are provided uniformly around the adjustment wheel 83, 5 such that the teeth 43 of the user control 41 can be coupled with the plurality of teeth 87 at more than one location. That is, to allow coupling at different relative angular displacements. An annular flange 88, as shown in Fig. 9a, is provided to provide abutment surfaces for rotatable attachment with the carrier 91 (described in further detail below). A plurality of ridges 89 is provided on one side of the annular flange 88, as shown in Fig. 9b, to engage with a detent 10 means 96 to allow tactile feedback to the user whilst allowing adjustment of the separation distance in discrete increments. Carrier The carrier group 81 includes a carrier 91, which supports the second grinding element 21. The grinding element 21 may be push-fit into the carrier 91, or alternatively the carrier 91 15 may be molded onto the grinding element 21. Alternatively the grinding element 21 may be insert molded into the carrier 91. The carrier 91 and the adjustment wheel 83 are rotatably attached to each other such that the adjustment wheel 83 operatively carries the second grinding element 21 for movement along the concentric axis, whilst allowing relative rotation around the concentric axis between the 20 adjustment wheel 83 and the second grinding element 21. This rotatable attachment is achieved by providing the annular flange 88 of the adjustment wheel 83, between an annular shoulder 93 of the carrier 91, and a bearing ring 95 that is attached to the carrier 91. The carrier 91 includes a plurality of guide apertures 97 that receive guide elements 69 of 25 the stationary bracket 61. These guide elements 69 prevent the carrier 91 from rotating, in particular when the adjustment wheel 81 is rotated, or during use when the first grinding element 11 is rotated. A detent 96 is partially received in the bearing ring 95. The detent 96 is spring loaded to bias towards the plurality of ridges 89 of the adjustment wheel 83, to provide tactile feedback for 30 adjustment in discrete increments.

12 The carrier 91 also includes slots 99 that form part of a bayonet-type attachment for receiving the hopper 7. User control The user control 41 will now be described with reference to Figs. 8a and 8b. The user 5 control 41 includes a plurality of teeth 43 for coupling with the plurality of teeth 87 of the adjustment wheel 83. The teeth 43 are substantially uniform in size so that they can readily couple with the teeth 87 of the adjustment wheel 83 in more than one relative position, and preferably at discrete positions around the entire 360 degree range. A stop element 44 extends downwardly from the user control 41. The stop element is 10 received in the channel 75 of the stationary bracket 61 for restricting movement of the user control 41 within a defined range. A protrusion may assist the user by providing visual indicia of the position of the user control 41. This protrusion 45 may also function to increase the user's grip on the user control 41 during adjustment of the grind setting. 15 A spring loaded paddle 48 having a locking edge 49 is provided to allow the user control 41 to be clipped onto an annular edge 86 of the adjustment wheel 83. This is further assisted by lip 47. Base The base 3 of the grinder 1 will now be described, with reference to Figs. 5a and 1la. 20 The base 3 includes the first grinding element 11 that is rotatably driven by a motor (not shown) around substantially the same axis as the concentric axis.. The first grinding element 11, although rotatable, is of a fixed axial displacement along the concentric axis. In this embodiment, the first grinding element 11 is mounted to a rotatable shaft 110, which in turn is supported by a pair of ball bearings 108 (see Fig. 1 la). By providing a relatively 25 short shaft length between the bearings 108 and the first grinding element 11, deviation of the grinding element 11 from the concentric axis due to lateral force is reduced. In one embodiment, the rotatable shaft 110 is coupled to the motor by a belt drive (not shown). In some electric motors, the shaft has "end-float" or "end-play" whereby the shafts have some axial movement. Thus if a grinding element is mounted directly to the shaft of the electric 30 motor, there may be some axial movement in the grinding element. By using a belt drive that is 13 intermediate the shaft of the motor and the first grinding element 11, this may reduce or prevent the effects of "end-float" or "end-play". The base 3 includes slots 101 for receiving and engaging lugs 63 of the stationary bracket 61. To prevent the stationary bracket 61 from disengaging from the base 3, a spring loaded 5 locking member 15 is provided to slot into slot 65 of the stationary bracket 61. A release button 16, integrally formed with the locking member 15, allows the user to retract the locking member 15 so that the stationary bracket 61 can be disengaged. In an alternative embodiment the release button may be separate from the locking member 15 and be operatively connected by a linkage. The internal curved surface 106 may be CNC machined to provide a curved surface that 10 is concentric to the concentric axis. A chute 17 provides a passage for ground coffee from the grinding elements 11, 21 to the opening 9. Operation of the grinder - Adjustment of the separation distance Adjustment of the "grind setting" for the grinder 1 during normal use will now be 15 described with reference to Figs. 10a to 1 1c. Maximum "grind setting" in the defined range Figs 10a and 1la show the grinder with the user control 41 at the maximum "grind setting", where the stop element 44 of the user control 41 is in abutment with the first stop surface 71. 20 Referring to Fig. 1 la, the second grinding surface 23 is at a relatively maximum separation distance from the first grinding surface 13, for this particular defined range of distances. This will give a relatively coarse-ground coffee. Since the user control 41 is positioned to the maximum "grind setting", which is stopped by the first stop surface 71, the user would not be able to achieve greater coarseness without 25 recalibrating the grinder 1. Intermediate "grind setting" in the defined range Figs. 10b and 1 lb show the grinder with the user control 41 at an intermediate "grind setting", wherein the user control 41 is in the middle between the maximum and minimum setting. The stop element 44 in the channel 75 is approximately halfway between the first stop 30 surface and second stop surface 73.

14 Referring to Fig. 1 ib, the second grinding surface 23 is closer from the first grinding surface 13 when compared to the maximum "grind setting" in Fig. 11 a. This will produce ground coffee that is finer than the maximum "grind setting". Minimum "grind setting" in the defined range 5 Figs. 10c and 1 ic show the grinder with the user control 41 at a minimum "grind setting", wherein the stop element of the user control 41 abuts the second stop surface 73. Referring to Fig. 1 1c, the second grinding surface 23 is at a relatively minimum separation distance from the first grinding surface 13, for this particular defined range of distances. This will give the finest (i.e. smallest) ground coffee. 10 Since the user control 41 is positioned to the minimum "grind setting", which is stopped by the second stop surface 73, the user would not be able to achieve finer (smaller) ground coffee without recalibrating the grinder 1. Operation of the grinder - Calibration of the grinder As the grinder is used, the first and second grinding surface 13, 23 will wear out. 15 Consequently, the minimum "grind setting" may provide ground coffee that is coarser than the user would desire. Alternatively, a grinder may be assembled at the factory with a defined range of distances for the separation distance that does not cover the separation distances the particular end user desires. In such cases, the grinder 1 can be calibrated so that the defined range of distances covers a separation distance that the user desires. 20 To calibrate the grinder, safety precautions such as switching off the grinder 1 and removing power cords, etc should be performed to minimise risk to the user. To assist in disassembly, the hopper 7b is removed as shown in Fig. 2, which fully exposes the user control 41 for separation from the other components of the burr adjustment module 51. The paddle 48 (see Figs. 8b and 10a) of the user control 41 is then manipulated to 25 release the locking edge 49 from the annular edge 86 of the adjustment wheel 83. The user control 41 is then removed. Figs. 3a and 3b shows the grinder 1 with the adjustment wheel 83 exposed for calibration of the grinder 1. The user can directly rotate the adjustment wheel 83 so that the carrier 91 and the second grinding element 21 are displaced along the concentric axis. In the case where the 30 first and second grinding surfaces 13, 23 have worn, the user may for example rotate the 15 adjustment wheel 83 (in the illustrated embodiment, rotating clockwise) so that the carrier 91 moves towards the base 3 (and so that the second grinding surface 23 moves towards the first grinding surface 13) to compensate for the worn surfaces. Alternatively, the user may rotate the wheel 83 in a direction until the desired separation distance is achieved. 5 Once the user has made the adjustments to the desired separation distance, the user control 41 is replaced by clipping onto the adjustment wheel 83. Calibration is then complete. In one method of calibration where the user wants to calibrate the grinder to index from the smallest separation distance within the defined range of distances, the user may rotate the adjustment wheel 83 to the smallest separation distance they desire. The user can then replace 10 the user control 41, with the user control 41 orientated at the minimum "grind setting" as shown in Fig. 10c. That is, the user control 41 is orientated so that the stop element 44 is close to or abutting the second stop surface 73. In another method of calibration where the user wants to calibrate the grinder to index from a desired separation distance that is approximately halfway in the defined range of 15 distances, the user can first rotate the adjustment wheel 83 to the desired separation distance. The user can then replace the user control 41 that is orientated to the intermediate "grind setting" as shown in Fig. 10b. Thus the middle of the defined range of distances is at the user's preferred or desired separation distance, and the user may deviate to a coarser or finer setting from this desired separation distance. 20 In yet another method of calibration where the user wants to calibrate the grinder to index from the largest separation distance within the defined range of distances, the user may rotate the adjustment wheel 83 to the largest separation distance they desire. The user can then replace the user control 41, with the user control 41 orientated at the maximum "grind setting" as shown in Fig. 10a. That is, the user control 41 orientated so that the stop element 44 is close to or abutting 25 the first stop surface 7a. Removal of the burr adjustment module The burr adjustment module 51 may be removed as a complete module as shown in Fig. 5a by depressing release button 16. This allows the user to inspect and clean the grinder 1. Advantageously, the burr adjustment module 51 can be removed without disturbing the position 30 of the user control 41 relative to the other components of the burr adjustment module 51. Thus the user would not lose their particular "grind setting" during inspection and cleaning.

16 In addition to not disturbing the "grind setting", removing the burr adjustment module 51 as a whole, allows the user to remove and replace the module 51 without having to re-calibrate the grinder 1. However, it is to be appreciated that a user may wish to remove components of the burr 5 adjustment module 51 separately, and as shown in Figs. 4a and 4b, the carrier group 81 and the stationary bracket 61 are separated together. This situation may occur if, for example, during calibration the user decides further disassembly and cleaning is warranted. Safety interlock In the illustrated embodiment, the grinder 1 is provided with a safety arrangement to 10 prevent operation of the grinder if the hopper 7 and the burr adjustment module 51 are not correctly assembled with the base 3. The safety arrangement includes a safety element 103 as shown in Figs. 7a and 9c. The safety element 103 is spring-loaded generally upwards to a "locked position" and is located within a track 107 of the carrier 91. When the hopper 7 is mounted to the carrier 91 via the slots 99, a protrusion from the mounting attachment of the 15 hopper 7 depresses the safety element 103 downwardly to an "unlocked position". The safety element 103, in turn depresses a plunger 105 in the base 3 (best illustrated in Fig. 5a). The plunger 105 in turn is operatively connected to a detection means, in the form of a micro switch (not shown), that is in communication with a controller of the grinder 1. When the plunger 105 is depressed (i.e. in the unlocked position), it indicates that the carrier group, and the hopper 7 20 are correctly assembled with the base 3, and the controller allows operation of the grinder 1. If the plunger 105 is not depressed (i.e. in the locked position), the controller prevents operation of the grinder 1 to reduce the risk of the grinder operating and causing injury or damage. The safety element 103 passes vertically through an aperture in the carrier 91. Since the carrier 91, in generally, only moves vertically during adjustment of the separation distance, this 25 allows the safety element 103 to remain generally in the same position in the horizontal plane during such adjustment. That is, rotation of the user control 41 and/or the adjustment wheel 83 does not change the radial or angular location of the safety element around the concentric axis. In the another embodiment, the micro switch may be connected to a relay switch connected to the electrical power input to the grinder 1 or the motor of the grinder to prevent 30 operation of the grinder 1 when the grinder 1 is not fully assembled.

17 Flat burr grinder In another embodiment of a grinder, aspects of the present disclosure are provided for use with a flat burr grinder. A flat burr grinder includes first and second grinding plates as the respective first and second grinding elements. The plates each have a grinding surface, wherein 5 the first grinding surface of the first grinding plate opposes the second grinding surface of the second grinding plate. An aperture is provided centrally in at least one of the plates to allow coffee beans to be fed between the plates, whereby relative rotation of the two plates grinds the beans. In one form, a flat burr grinder includes a stationary plate with the aperture positioned 10 above a rotating lower plate. The coffee is fed through the central aperture, and ground coffee is forced radially outwards from the centre. Alternative adjustment means In the described embodiment the user control and adjustment means are located proximal to the burrs. However, it is to be appreciated that in some other embodiment, the user control 15 may be located away from the burrs (grinding elements). For example a user control may be provided on the side of the base 3 of the grinder. The user control may be operatively connected to the adjustment means, such as through an arrangement of gears and/or linkages. Such an arrangement would also allow adjustment of the separation distance between the grinding elements as described in the above mentioned embodiment. 20 Chute flap An embodiment of a chute flap for the chute 17 will now be described with reference to Figs. 12 to 16c. A chute assembly 201 includes two body halves 203, 205 that form the chute 17 having an inlet 217 and an outlet 219. This inlet 217 provides a substantially horizontal pathway into 25 the chute 17, and the outlet 219 provides a substantially vertical pathway for ground coffee to drop out of the chute 17. The two body halves have internal walls 213, which oppose each other. As shown in Fig. 14, the internal walls 213 have faces at a diverging angle 216 from the inlet to the outlet 219. This ensures the chute has an increasing cross-sectional area from the inlet 217 to the outlet 219 to reduce the risk of blockages forming. The body halves 203, 205 of the chute 30 may be made of a number of materials, including but not limited to acetyl, folded stainless steel sheets, ABS plastic (acrylonitrile butadiene styrene), polypropylene and other polymers.

18 A lower wall 215 is formed at the lower periphery of the body halves 203, 205 and is angled at a slope from the inlet 217 to the outlet 219. A flap 207 is provided that covers the path of the chute 17. In the illustrated embodiments the flap 207 is located within the chute 17, to provide back pressure to the ground 5 coffee. As discussed above, this facilitates clumping of the ground coffee until the upstream pressure overcomes the mechanical resistance of the flap 207 which then opens to allow the clumps to pass through the chute 17. This reduces static in the ground coffee. The flap 207 may be made of an elastomeric material. In one embodiment, it is made of a food-grade silicone material. Alternatively, it could me made of acetyl, nylon, ABS plastic, 10 polypropylene, santoprene@ elastomers (thermoplastic vulcanizates). In other embodiments, the flap 207 may be made of spring steel, stainless steel shims. In yet another embodiment the flap 407 may be made of bent spring wire as shown in Fig. 17. In one embodiment, the flap 207 has a durometer hardness value of around 65. The flap 207 is resilient so that the flap 207 can provide the back pressure and return to the closed or 15 substantially closed position after grinding. The flap 207 is of a substantially T cross-section, which is received in corresponding slots 209 of the body halves 203, 205 as shown in Fig. 13. This slotted arrangement facilitates ease of assembly and does not require separate fasteners to retain the flap 207 with the other components of the chute assembly 201. 20 The flap 207 may optionally include a stainless steel or spring steel insert molded with the flap for additional strength. This may be molded so that the insert is entirely overmolded by the elastomeric material. Alternatively, the insert may be partially exposed. In a further embodiment, the insert may be further biased to the closed position by a torsion spring for additional back pressure. The torsion spring may be integral to the insert, or separately formed. 25 In one embodiment, the flap 207 is longer (in the axis from the T slot to the distal end) than it is wide (in the axis between the opposing internal walls 213 of the halves 203, 205). This allows the spread of the bending flap 207 to bend evenly. This is best shown in Figs. 16a to 16c. The width of the flap may be slightly less than the corresponding width of the chute 17 (i.e. the distance between the opposing internal walls 213) to reduce the chance of the flap 207 30 touching the walls 213, which may hinder movement of the flap 207.

19 Operation of an embodiment of the flap 207 will now be described with reference to Figs. 16a to 16c. When the flap 207 is removed from the chute assembly 201, the flap 207 is substantially T shaped. When the flap 207 is assembled with the chute assembly 201, the lower portion of the flap 207 is slightly bent when at the closed position as shown in Fig. 16a. Thus in 5 this embodiment, even at the closed position, the flap 207 is pre-stressed, which increases the back pressure against the ground coffee. When the ground coffee is fed into the inlet 217, the ground coffee is initially stopped by the closed flap 297 and collects in the chute 17 upstream of the flap 207. Once a sufficient amount of ground coffee collects, and the pressure from the ground coffee forced through the 10 inlet 217 overcomes the counteracting pressure from the flap 207, the flap 207 bends to allow some ground coffee to flow, as shown in Fig. 16b. Additional pressure from the ground coffee will bend the flap 207 even more to allow more ground coffee to flow as shown in Fig. 16c. As shown in Fig. 16a, a plane of a lower portion of the flap 207 converges and meets with a plane of the lower wall 215. Advantageously, this arrangement allows even small 15 deflections in the flap 207 to provide sufficient passage for the ground coffee to flow though the chute 17. Furthermore, the location where the flap 207 and lower wall 215 meet is at a slope, which assist in the flow of ground coffee through the chute 17 when the flap 207 is deflected by pressure from the upstream ground coffee. An alternative embodiment of the flap 307 is shown in Fig. 15. In this embodiment, the 20 flap 307 is relatively shorter than the flap 207 shown in Fig. 16a. This shorter flap 307 at rest in the closed position is substantially T shaped. In this embodiment, there is less (or even no) pre stressing of the flap 307. This may reduce the back pressure to the ground coffee. However, it should be noted that the shorter flap 307, may have a different width to length ratio that may affect the force/pressure required to bend the flap 307 to the open position. 25 Furthermore, selection of material, and material properties of the flap 307 may be made to adjust the required back pressure, to be the same as, or even more than that of the embodiment shown in Figs. 16a to 16c. 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 30 from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims (27)

1. A grinder including: - a first grinding element having a first grinding surface; - a second grinding element having a second grinding surface, wherein at least one 5 portion of the first grinding surface opposes at least one portion of the second grinding surface, the opposing portions separated by a separation distance, and wherein the first and second grinding surfaces are movable relative to one another to grind a product in between the opposing portions, - an adjustment means for selectively adjusting the separation distance; and 10 - a user control operatively coupled with the adjustment means, wherein the user control has restricted adjustment of the separation distance within a selectively defined range of distances, and wherein the user control and/or adjustment means can be calibrated to select the defined range of distances. 15

2. A grinder according to claim 1, further including: - a first stop means that operatively stops adjustment of the separation distance to a minimum distance, wherein calibration of the user control and/or adjustment means vary the minimum distance in the selected defined range of distances. 20

3. A grinder according to any one of the preceding claims including: - a second stop means that operatively stops adjustment of the separation distance to a maximum distance, wherein calibration of the user control and/or adjustment means varies the 25 maximum distance in the selected defined range of distances. 21

4. A grinder according to claim 3 when dependent on claim 2, wherein the first and second stop means limits movement of the user control, thereby restricting adjustment of the separation distance within the defined range of distances. 5

5. A grinder according to any one of the preceding claims, wherein the difference between the minimum distance and the maximum distance is constant.

6. A grinder according to any one of the preceding claims wherein the grinder is a 10 conical burr grinder, wherein: - the at least one portion of the first grinding surface includes a substantially frusto-conical surface facing outwardly, - the at least one portion of the second grinding surface includes a substantially frusto-conical surface facing inwardly, 15 - the opposing first and second portions are concentric, - the second grinding element receives at least part of the first grinding element, wherein the adjustment means operatively provides relative movement of the first and second grinding elements along a common concentric axis to adjust the separation distance between the opposing portions. 20

7. A grinder according to claim 6 wherein the adjustment means is a screw adjustment rotatable in a first direction to decrease the separation distance between the opposing portions, and rotatable in an opposite second direction to increase the separation distance between the opposing portions. 25 22

8. A grinder according to claim 7, wherein the adjustment means includes: - a stationary bracket with a first threaded portion, the stationary bracket positioned at a fixed axial displacement along the concentric axis, - an adjustment wheel having a second threaded portion for engagement with the 5 first threaded portion, the adjustment wheel operatively carrying the second grinding element, wherein rotation of the adjustment wheel in the first or second direction displaces the second grinding element along the common concentric axis to adjust the separation distance.

9. A grinder according to claim 8, wherein the adjustment wheel and the user control 10 can be coupled together at a plurality of different relative angular displacements to each other.

10. A grinder according to claim 9, wherein the adjustment wheel and the user control each have complementary teeth to allow coupling at different relative angular displacements. 15

11. A grinder according to any one of claims 8 to 10, wherein: - the stationary bracket further includes: - a first stop surface; and - a second stop surface, - the user control further includes at least one stop element, 20 wherein the first and second stop surfaces provide limits to the movement of the stop element, such that user control can only adjust the separation distance within the defined range of distances. 23

12. A grinder according to any one of the preceding claims when dependent on claim 6, further including a guide means for allowing the second grinding element to move axially along the common concentric axis, whilst preventing rotation of the second grinding element around the common concentric axis. 5

13. A grinder according to any one of claims 8 to 12, wherein the stationary bracket is releasable attached to a base of the grinder.

14. A grinder according to claim 13, wherein the adjustment means and user control 10 are part of a burr adjustment module, wherein detaching the stationary bracket from the base of the grinder also detaches the burr adjustment module from the base of the grinder.

15. A grinder according to claim 14, wherein the burr adjustment module can be detached and attached to the base of the grinder without disturbing the selection of the user 15 control for a corresponding separation distance.

16. A grinder according to either claim 14 of 15, wherein the burr adjustment module further includes a carrier, wherein the carrier supports the second grinding element, and wherein the carrier is rotatably attached to the adjustment wheel such that the adjustment wheel 20 operatively carries the second grinding element whilst allowing relative rotation between the adjustment wheel and the second grinding element.

17. A grinder according to any one of claims 14 to 16, wherein a hopper container is releasable attached to the burr adjustment module. 25 24

18. A grinder according to claim 17, wherein the hopper container is releasably attachable to the carrier.

19. A grinder according to either claim 17 or 18, further including a safety 5 arrangement, wherein the safety arrangement prevents operation of the grinder if the hopper container and the burr adjustment module are not correctly assembled with the base of the grinder.

20. A grinder according to claim 19, wherein the safety arrangement includes a safety 10 element passing through the carrier, wherein when the hopper is attached to the carrier, the safety element is displaced to an unlocked position, and wherein when the hopper is detached from the carrier, the first safety element is displaced to a locked position, wherein a detection means is provided in the base of the grinder to detect the displacement of the safety element. 15

21. A grinder according to any one of the preceding claims wherein at least one of the first or second grinding elements is operatively coupled and rotated by a motor when the grinder is in use. 20

22. A grinder according to any one of the preceding claims wherein the second grinding element is stationary when the grinder is in use.

23. A grinder according to any one of the preceding claims further including indicia to indicate to the user the selected separation distance within the defined range of distances. 25 25

24. A grinder according to any one of the preceding claims further including a detent means operative on the user control or adjustment means, wherein the detent means provide tactile feedback to the user to allow adjustment of the separation distance within the defined range of distances in discrete increments. 5

25. A grinder according to any one of claims 1 to 5 wherein the grinder is a flat burr grinder, and the first and second grinding elements include respective first and second grinding plates.

26. A grinder including: - a grinding mechanism for grinding a product to a ground product; 10 - a chute for providing a passage for the ground product from the grinding mechanism to an outlet, - a flap provided in the chute for applying back pressure to the ground product passing through the chute, wherein the flap is at least partially made of an elastomeric material. 15

27. A grinder according to claim 26, wherein a lower portion of the flap is movable between a closed position and an open position, and the chute includes a lower wall, wherein at the closed position, a plane of the lower portion of the flap converges and meets with a plane of the lower wall. 20