The present invention relates to a coffee bean grinder

The object of the present invention is to provide an improved coffee bean grinder.

According to my invention, I provide a coffee bean grinder comprising:

• a body,

• a burr mounting in the body and including:

• a passage via which beans to be ground can pass and

• a boss supported within the passage,

• a complementary pair of complementary burrs or serrated grinding wheels carried by the burr mounting on a burr axis;

• an upper and/or outer one of the burrs being journalled in the bun- mounting at a determined position along the burr axis and being adapted to be driven in rotation about the burr axis and

• a lower and/or inner one of the burrs being restrained from rotational in the mounting and mounted adjustably along the burr axis,

• a shaft supported irrotationally in the boss for axial movement and integral with or carrying the lower/inner burr and

• an adjustment member engaged with the shaft for adjusting the position of the shaft and lower/inner burr along the burr axis, the adjustment member crossing the passage.

The burrs may be "flat" burrs, which are nevertheless sufficiently tapered for coffee beans to pass between them at a central bore in an upper one of them and out as ground coffee at their peripheries, in which case, they are arranged one above the other on the burr axis. In other words, such burrs are a pair of round, flat burrs, arranged one above the other on the burr axis, an upper one having a central bore and grinding teeth in a lower face and a lower one having grindng teeth in an upper face, the teeth being tapered for coffee beans passing through the central bore to be received between the burrs and pass out radially, as ground coffee at their peripheries. Alternatively, they may be tapered burrs, in which case, the burrs are arranged one at least partially within the other on the burr axis. In other words, these burrs are a pair of cylindrical, tapered burrs, arranged one at least partially within the other on the burr axis, an outer one having a central bore and grinding teeth in an inner surface and an outer one having grinding teeth in an outer surface, the teeth being tapered to receive coffee beans passing down between their surfaces from above the burrs and out axially below the burrs, as ground coffee.

In adjusting the position of the lower/inner burr, the adjustment member facilitates adjustment of the fineness with which the coffee beans are ground, in that the ground coffee is more finely ground when the burrs are closer to each other.

Whilst I can envisage that the determined position of the journalled burr could be selected from a numeral of positions along the burr axis at which the burr is journalled, with fine adjustment of the grind being adjusted by the adjustment member, I prefer for the journal position to be permanently set.

Provision of the shaft within the boss and the adjustment member crossing the passage allows an unimpeded route for the beans to the burrs via the passage.

Whilst the adjustment member can be envisaged to cross the passage exposed to contact with beans passing through the passage; preferably the adjustment member is accommodated within a fixed member crossing the passage. Conveniently the fixed member supports, or contributes to the support of, the boss. The support can be open towards the burr, but is preferably closed with a way through it for the adjustment member. Preferably, the support, the boss and part of the burr mounting are integrally formed. In the preferred embodiment, the burr mounting is comprised of the upper and lower parts screwed together to contain components between them.

Whilst I envisage that the adjustment member could be arranged for rotational movement in the support for the boss and include a pinion engaged with rack teeth cut in the shaft or a cam engaged with the shaft, it is preferably a lever finger engaged with the shaft and arranged for movement in the boss. To control the position of the adjustment member, an adjustment mechanism will normally be provided.

Preferably, I provide the adjustment member as:

• a lever having:

• a fulcrum supported on the burr mounting or the body,

• an inner end engaged directly or indirectly, preferably via the shaft, with the lower / inner burr for its adjustment along the axis and

• an outer end.

In this case, the adjustment mechanism can be:

• means acting between the outer end of the lever and the body to move the outer end for adjustment of the position of the lower / inner burr along the axis with respect to the upper / outer burr.

The lever could be mounted at an aperture on a pin fast in the burr mounting or body at the fulcrum. However I prefer to provide the lever as a rod having a fulcrum swelling engageable in a recess in the burr mounting or body.

I can envisage the lever acting at a ratio, being the ratio of the distance from the fulcrum to the adjustment mechanism divided by the distance from the fulcrum to the end engaged with the burr shaft, from 2:1 to 5:1. It is more likely to be between 3:1 and 3.5:1 and in the preferred embodiment is 3.2:1.

In the preferred embodiment, a spring is provided for urging the shaft against the lever for avoiding backlash, with the adjustment mechanism acting in the same direction on the outer end of the lever. Preferably the spring, via the shaft, and the adjustment mechanism bear down on the lever.

Preferably the adjustment mechanism includes a cam of the type having a cam surface extending helically, the cam being arranged for rotation about an axis parallel to the axis of the burrs and bearing on the top of the outer end of the lever. The bean passage in the burr mounting can be either tapered or a substantially parallel passage. Preferably, the burr mounting or the body has a coffee beans inlet funnel aligned with the bean passage. Normally a ground-coffee, outlet funnel fast with the burr mounting and/or the body, but possibly removable for cleaning will be provided beneath the lower burr for directing the ground coffee into a receptacle for infusion.

Preferably, the receptacle is of tall/narrow shape with an outer rim shaped to assist inverted location over a portafilter for transferring the ground coffee into the portafilter. Further the receptacle has a flat circular base sized to fit inside the portafilter for evenly tamping the ground coffee into the portafilter.

Whilst in certain embodiments, the shaft carrying the non-rotating burr is radially located in the burr mounting via a bore in the burr mounting; preferably the shaft carrying the non-rotating burr is radially located in the burr mounting via a radial location member, preferably a plate adjustably fitted to the burr mounting.

In accordance with a particular feature, a lower or distal end of the non- rotating one of the burrs is radially located by:

• a location ring radially located by a bearing, or a housing therefor, in which the rotating burr is radially located and

• radial features extending from the non-rotating burr, or a location member fast with it, with the radial features locating in the location ring.

According to a second aspect of the invention I provide a coffee grinder comprising:

• a body, having a base, a stem and an upper limb extending from the stem,

• a burr mounting fast with upper limb of the body,

· a complementary pair of complementary burrs or serrated grinding wheels carried by the burr mounting on a burr axis that is substantially vertical with the grinder in its use orientation; • an upper and/or outer one of the burrs being journalled on the burr i mounting at a determined position along the axis and being adapted to be driven in rotation about the axis and

• a lower and/or inner one of the burrs being restrained from rotational in the mounting and mounted adjustably along the axis, and

• means for driving the upper and/or outer one of the burrs, the driving means including:

• drive formations on an outer circumference of the upper and/or outer one of the burrs,

• a drive motor in the stem of the body,

• reduction gearing arranged above the drive motor and

• a drive train between an output of the reduction gearing and the drive formations on the upper/outer burr.

Whilst I envisage that the drive train between the gearbox and the driven burr could be a toothed belt drive, because this is a low speed / high torque drive as opposed to a high speed / low torque drive, I prefer to provide the drive train as a gear train with an idler gear between the reduction gearing and the driven burr.

In order to accommodate the drive motor in the stem, I prefer to provide the motor as a high speed /low torque motor rotating with an output speed in the range 4,000rpm to 20,000rpm as opposed to the opposite. In order to provide a significant speed reduction in the gearing, I prefer to provide the gearing as an epicyclic gearbox with a gearing ratio reduction in the range from 1 :10 to 1 :30. In the preferred embodiment, I provide a two stage epicyclic gearbox, together with a further reduction in the drive train. Alternatively this epicyclic gearbox and motor assembly can be replaced by an induction motor rotating with an output speed in the range of 400rpm to 4,000rpm.

According to a third aspect of my invention, I provide a coffee grinder comprising:

• a body,

• a burr mounting fast with the body, • a complementary pair of complementary burrs or serrated grinding wheels carried by the burr mounting on a burr axis that is substantially vertical with the grinder in its use orientation;

• an upper and/or outer one of the burrs being journalled on the burr

mounting at a determined position along the axis and being adapted to be driven in rotation about the axis and

• a lower and/or inner one of the burrs being restrained from rotational in the mounting and mounted adjustably along the axis, and

• a funnel extension of the mounting and

• a removable bean doser fitted to the funnel, the doser being adapted to

dispense a volumetric dose of beans to the funnel for passage on to the burrs.

Preferably, the doser has:

• a rotatable body including a plurality of individually fillable dosing

chambers together with a blank or absent chamber all, equi-radially arranged in the body.

• a delivery portion having the body rotatably mounted on it and being non- rotationally complementary to the funnel extension, with a dosage supply conduit for receiving the predetermined quantity of coffee beans from a respective dosing chamber rotated into alignment with the supply conduit.

To help understanding of the invention, various specific embodiments thereof will now be described by way of examples and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a grinding machine according to the invention;

Figure 2 is a transverse sectional view through the grinding machine of Figure

1;

Figure 3 is a close-up view in transverse section of the grinding mechanism of the grinding machine of Figure 1;

Figure 4 is a close-up view in transverse section of a second embodiment of the grinding mechanism; Figure 5 is a close-up view in transverse section of a third embodiment of the grinding mechanism;

Figure 6 shows two perspective views of an optional dosing mechanism for use with the grinding machine of Figure 1 ;

Figure 7 is a partial perspective view and a side elevation of the grinding machine of Figure 4, showing how the dosing mechanism of Figure 6 can be mounted thereto;

Figure 8 shows two transverse sectional views through the dosing mechanism of Figure 6;

Figure 9 is a close-up view in transverse section of;

Figure 10 is a perspective view showing the dosing mechanism of Figure 6 mounted on the grinding machine of Figure 4;

Figure 11 a front perspective view of a fourth coffee bean grinder in accordance with the invention;

Figure 12 is a corresponding rear perspective view;

Figure 13 is a central cross-sectional view of the coffee bean grinder of Figure

11;

Figure 14 is a perspective at the same angle as Figure 12 of a sub-assembly within the body of the coffee bean grinder of Figure 11 ;

Figure 15 is a cross-sectional view similar to Figure 13 of the sub-assembly of

Figure 1 ; and

Figure 16 is an underneath perspective view of a lower washer and location collar of the coffee grinder of Figure 11.

Figure 17 is an alternative embodiment central cross-sectional view of the coffee bean grinder of Figure 11 ;

Figure 18 is a top view of the coffee bean grinder sub-assembly of Figure 17 with the bean ejector baffle 333 removed for clarity.

Figure 19 is a bottom view of the coffee bean grinder sub-assembly of Figure 17 with the lower inner burr 341 and outlet funnel 331 both removed for clarity.

Referring firstly to Fig. 1, there is shown a grinding machine 1 according to an embodiment of the invention, which is primarily, but not exclusively, intended for use as a coffee grinder. The grinding machine 1 has a body 3. Material to be ground, such as coffee beans, can be introduced into the grinding machine 1 through an input funnel 39, which could be provided with an optional lid (not shown) designed to prevent unground material being ejected from the funnel 39 during the grinding operation. The material to be ground then passes under gravity through a grinding mechanism 9 to exit as a finer ground product, such as coffee powder, at outlet port 81. A stand 85 for receiving a portionised receiver 83 or a general storage vessel (not shown) for the ground product 82 is located under the outlet port 81. Such a portionised receiver 83 is sometimes known as a portafilter. The stand 85 comprises means for locating and holding the portionised receiver 83. Thus the portionised receiver 83 may be fitted to stand 85 and charged with ground product 82 from the outlet port 81 , before being transferred to an espresso machine, for example.

Fig. 2 shows a transverse sectional view through the grinding machine 1 of Fig. 1. As may be seen in Fig. 2, the body 3 of grinding machine 1 contains an electric motor 7 fitted with an optional cooling fan 8. Electric motor 7 acts as a source of motive power for a drive shaft 5, causing it to rotate about a longitudinal axis A-A' when motor 7 is activated by a user via on/off switch 87. As may also be seen in Fig. 2, the grinding mechanism 9 comprises lower / inner and upper / outer grinder burrs, which in the case of this embodiment are referred to as an inner grinding burr 11 (having a central axis B-B') and an outer grinding burr 13 concentric with the central axis of the inner grinding burr, with an annular channel 15 located between the inner and outer grinding burrs. The grinding burrs are usually made from hardened steel or ceramic materials, although other materials are envisaged.

The grinding mechanism 9 is motively connected to the drive shaft 5 via a transmission 17 which transmits power from the drive shaft 5 to the grinding mechanism 9, although in an alternative arrangement to that shown in Fig. 2, the grinding mechanism 9 could instead be motively connected directly to the drive shaft 5. In either case, rotation of the drive shaft 5 about the longitudinal axis A-A' by the electric motor 7 causes the inner and outer grinding burrs 11, 13 to rotate relative to each other about the central axis B-B' to grind material to be ground within the annular channel 15 located therebetween. The outlet port 81 is in communication with the annular channel 15 and is adapted to receive the ground product 82 and both direct and focus it towards the portionised receiver 83 below. It is envisaged that the internal surface of the outlet port 81 could be coated with a non-stick or similar low friction coating to facilitate complete transfer of all ground product 82 from annular channel 15 to portionised receiver 83 or receiving vessel.

The drive shaft 5 is motively connected to the outer grinding burr 13, such that when the drive shaft rotates, the inner grinding burr 11 remains static relative to the body 3 of the machine and the outer grinding burr 13 rotates about the inner grinding burr 11. It is generally envisaged that the outer grinding burr 13 will tend to operate in, a rotational speed range of, but not limited to, between lOOrpm and 2000 rpm. Outer burr 13 rotational speed will depend on factors such as burr diameter, burr tooth design, motor power, required rate of through put etc.

This rotation of the outer burr 13 relative to the static inner burr 11 has the advantage that the connection between the drive shaft 5 and the grinding mechanism 9 does not have to cross the pathway of the material to be ground from the entry point of the input funnel 39 through the annular channel 15 between the inner and outer grinding burrs to the exit point of the outlet port 81 and the ground product 82 is able to progress through the grinding mechanism 9 unimpeded. The portionised receiver 83 may therefore be readily positioned in close proximity and directly under the outlet port 81 by a user.

In particular, in this embodiment, the longitudinal axis A-A' of the drive shaft 5 is offset from and parallel to the central axis B-B' of the inner grinding burr 11, so that the motor 7 and transmission 17 are also both offset from the pathway of the material to be ground through the grinding mechanism 9. In an alternative

embodiment, the longitudinal axis A-A' of the drive shaft 5 could instead be arranged perpendicular to the central axis B-B' of the inner grinding burr 11 with a

transmission comprising right-angled gears to motively connect the drive shaft 5 to the grinding mechanism 9, in such an alternative arrangement, both the motor 7 and the transmission 17 would therefore also be out of the pathway of the material to be ground through the grinding mechanism 9. The embodiment shown in Fig. 3 has the advantage of a more compact arrangement than this alternative, however.

Fig. 3 is a close-up view in transverse sectional view of the grinding machine 1 of Fig. 1, which shows the grinding mechanism 9 and how it works in greater detail. As may be seen in Fig. 3, the outer grinding burr 13 rotates inside a bearing 18 and has a first set of gear teeth 19 and the drive shaft 5 has a second set of gear teeth 21 which engage indirectly with the first set of gear teeth 19 via the transmission 17. To achieve this indirect engagement, the transmission 17 comprises of gear wheels 23 and 24 individually having sets of gear teeth 20 which engage with both the first and second sets of gear teeth 19, 21 of the outer grinding burr 13 and the drive shaft 5. This allows the high-speed, but low torque rotation of the electric motor 7 to be stepped down to a low speed but high torque rotation of the outer grinding burr 13 in two steps. In an alternative possible arrangement, such as where the drive shaft 5 was hand-operated as a source of motive power and could therefore be provided with a higher torque, the first set of gear teeth 19 on the outer grinding burr 13 could engage directly with the second set of gear teeth 21 on the drive shaft 5.

Fig. 3 also shows how a separation of the inner and outer grinding burrs 11 , 13, and hence a width of the annular channel 15 between the inner and outer grinding burrs, can be both consistently maintained and accurately adjusted. An outer grinding surface of inner burr 11 has the shape of a first cone and an inner grinding surface of the outer burr 13 also has the shape of a second cone but of opposite orientation to the first cone, so that the respective apices of the first and second cones lie on opposite sides, i.e. above and below, the grinding mechanism 9, except that a portion of the inner grinding surface of the outer burr 13 closest to the outlet port 51 has the shape of a third cone of the same orientation as the first cone, but larger.

It is generally envisaged that the outside diameter of the body of the outer burr 13 will be in the range of, but not limited to, 30mm to 100mm.

Material to be ground will therefore enter funnel 39 and be directed by the first and second cones towards the annular channel 15, which is located between the first and third cones. Since the inner and outer grinding burrs 11, 13 are movable relative to each other along a parallel central axis B-B\ this brings the first and third cones either closer to or further away from each other, and the width of the annular channel 15 between the inner and outer grinding burrs is accordingly adjustable by such parallel movement of one of the inner and outer grinding burrs relative to the other. Several other different arrangements of inner and outer grinding burrs are imaginable, however.

Preferably, as in the illustrated embodiment, the inner grinding burr 11 is fixed, so that it does not rotate, but is precisely movable parallel to the central axis B- B', whereas the outer grinding burr 13, while being driven in rotation, is vertically fixed relative to the body 3 of the machine. This movement of the inner grinding burr 11 parallel to the central axis B-B' is achieved as follows: The outside diameter of shaft 32 is sized so that it accurately fits within a similarly sized bore in central pillar 29. The first screw thread 27 is formed on the surface of bore 30 of shaft 32. This thread 27 engages with a shaft 33 having the second screw thread 28 formed on an outer surface thereof, the bore 30 and the shaft 33 being coaxial with the central axis B-B'. The shaft 33 further comprises a knob 35 on an end thereof for rotation of shaft 33 about its central axis by a user. Shaft 32 is also provided with a dowel pin 36 which slides in slot 37 in the gearbox housing 10, thereby preventing inner burr 11 from rotating, while allowing it to slide parallel to central axis B-B'. Thus, rotation by the user of knob 35 causes inner burr 11 to either be drawn towards outer burr 13 (thereby closing annular channel 15 for a finer grind) or rotation of knob 35 in the opposite direction causes inner burr 11 to move away from outer burr 13 (thereby opening annular channel 15 for a coarser grind). Spring 38 is positioned concentric to central axis B-B' and maintains a pressure on shaft 32 downward relative to body 3 of the machine, thereby removing backlash in the adjustment system.

The further advantage of this arrangement is that by completely unscrewing locking nut 12 from shaft 32 and unscrewing outlet port 81, both the grinding burrs 11 and 13 may be completely removed for cleaning or replacement of worn or broken parts, as may be appreciated from Fig. 3.

However, several different other arrangements for movement of the inner grinding burr 11 parallel to the central axis B-B' are also possible. For example, shaft 32 and inner grinding burr 11 could be formed integrally as a single component. In the illustrated embodiment, the knob 35 comprises a click-stop 25 to align a rotational position of the knob 35 about the central axis B-B' with a predetermined separation of the inner and outer grinding burrs 11, 13 and therefore a corresponding width of the annular channel 15 between the inner and outer grinding burrs 11 & 13. The click stop 25 comprises a number of indents equally spaced circumferential around the top surface of central pillar 29 which individually engage with a sprung loaded pin 26 located in underside of knob 35. This allows predetermined settings for the coarseness or fineness of the grinding mechanism to be rapidly selected by a user.

Fig. 4 is a close-up view in transverse sectional view of an alternative embodiment of the grinding machine 1 of Fig. 1 in which inner burr 11 is mounted from above and wherein vertical adjustment of inner burr 11 relative to outer burr 13 is carried out from the side. Fig 4 shows the grinding mechanism 9 and how it works in greater detail.

In this embodiment:

• The outer burr 13 is similarly driven in rotation but fixed vertically.

• The inner burr 11 is rotationally fixed but can be adjusted vertically.

• The inner burr 11 is attached to the shaft 32 and fixed by locking nut 12 from below.

• Grinding mechanism 9 has a gearbox housing 10 produced by two mating halves.

• The upper half of the gearbox housing 10 is provided with an inner bore 31.

• Shaft 32 is sized to accurately slide vertically within this inner bore 31.

• Shaft 32 has a slot 40 machined in it and fitted with a pin 41.

• Gearbox housing 10 is provided with a side slot 42 and pivot pin 43 off to one side of central axis B-B'.

• A lever arm 44 is provided and positioned so as to fit inside slot 42 of gearbox housing 10 and to pivot on pivot pin 43 in the gearbox housing 10.

• Positioned in one end of lever arm 44 is an open slot 45 which locates

precisely with the pin 41 in shaft 32.

• Both shaft 32 and inner burr 11 are prevented from rotation by the engagement of lever arm 44 with slot 40 in shaft 32. • The other end of lever arm 44 in provided with a calibration screw 46.

• It should be noted that the distance from pin 41 in shaft 32 and the pivot pin 43 in gearbox housing 10 is significantly smaller than the distance from the pivot pin 43 in the gearbox housing 10 and calibration screw 46 (approx. 5:1).

• Calibration screw 46 passes, with clearance, through a hole in the body 3 and acts on the underside of rotatable dial 47.

• Rotatable dial 47 is provided with a continuous rib 48 mounted to its

underside.

• Continuous rib 48 is produced so that is of varying height about is

circumference.

• This variable height continuous rib 48 acts like a cam and engages with the end of the calibration screw 46.

• The action of rotating the dial 47 results in calibration screw 46 and hence the end of the lever arm 44, moving vertically, due to its action on the cam profile.

• This vertical movement is reduced by a factor of about 5: 1 at the other end of the lever arm 44, resulting in a very accurate and repeatable method of inner burr 11 adjustment.

• The calibration screw 46 is provided, so as to consistently allow the setting of the width of the annular channel 15 during production and subsequent servicing.

• The continuous nature and cam profile of continuous rib 48 on the underside of the rotatable dial 47 results in the adjustment of annular channel 15 being reset once 360 degrees of dial rotation is complete.

• A spring 38 is provided in a pocket in shaft 32 to provide constant pressure on shaft 32 in a downward direction, thus removing any backlash in the adjustment system.

• Numbers or similar markings are provided on the reverse side of the rotatable dial 47 to allow the user to clearly see the grind setting.

• Burrs 11 and 13 can be removed for cleaning, sharpening or replacement by removing the outlet port 81 and locking nut 12.

Thus the separation of the inner and outer grinding burrs 11 and 13, and hence the width of the annular channel 15 between the inner and outer grinding burrs 11 and 13, can be adjusted by rotating the dial 47. Otherwise, the general design is very similar to the embodiment of Fig. 3.

Fig. 5 is a close-up view in transverse sectional view alternative embodiment of the grinding machine 1 of Fig. 1. It is similar in construction to that of Figs. 3 and 4 but with an alternative method of both mounting the inner burr 11 and accurately adjusting the vertical height of the inner burr relative to the outer burr 13.

Turning now to Fig. 6 to 10, there is shown an optional dosing mechanism 71 for supplying a predetermined quantity of material to be ground to the annular channel 15 between the inner and outer grinding burrs 11, 13. The dosing mechanism 71 comprises a plurality of individually fillable dosing chambers 73. The respective volumes of the individually fillable dosing chambers 73 are the same as each other, so that if each is filled to a level top, it will contain the same predetermined quantity of material to be ground as the others. The dosing mechanism 71 further comprises a delivery portion 75 having a shape which can be mated with the funnel 39 of the grinding machine 1 in the manner indicated in Fig. 7 by the arrows labelled C. The delivery portion 75 comprises a dosage supply conduit 77 for receiving the predetermined quantity of material to be ground from one of the plurality of individually fillable dosing chambers 73 and supplying this predetermined quantity to the funnel 39.

Dosing mechanism 71 has an anti-rotation notch 88 which mates with an anti- rotation rib 89 in funnel 39 of grinding machine 1 in order to prevent relative rotation of dosing mechanism 71 and grinding machine 1. In an alternative embodiment, the rib 89 and notch 88 can be transposed or other locking features can be employed.

In use, dosing chambers 73 can be either filled by hand or automatically filled from an additional fixed bean feed hopper (not shown) mounted above dosing mechanism 71.

The construction of the dosing mechanism 71 and how it works in cooperation with the grinding machine 1 can be more readily appreciated from Figs. 7 to 10. The plurality of individually fillable dosing chambers 73 are rotatable relative to the delivery portion 75 about a central pivot 74, to align a selected one of the plurality of dosing chambers 73 with the dosage supply conduit 77. In the transverse sectional view of Fig. 9, none of dosing chambers 73 is aligned with the dosage supply conduit 77. Instead, the dosage supply conduit 77 is aligned with a blank portion 73a of the dosing mechanism 71, which may also be seen in Figs. 6 and 7. In this condition, even if all of the plurality of individually fillable dosing chambers 73 are charged with material to be ground, none of the material to be ground enters the dosage supply conduit 77. However, in the alternative close-up view in transverse section of the dosing mechanism 71 mounted to the grinding machine 1 of Fig. 7, there is shown the alternative condition in which one of dosing chambers 73 is aligned with the dosage supply conduit 77. In this case, material to be ground, contained in one of the dosing chambers 73, is able to enter the dosage supply conduit 77 in the direction indicated in Fig. 8 by arrows D D and pass from there into the grinding mechanism 9 below. The dosing mechanism 71 further comprises a click-stop 79 at each location where a respective one of the plurality of individually fillable dosing chambers 73 is aligned with the dosage supply conduit 77. The click-stop 79 comprises a plurality of indents each of which corresponds with a respective one of the dosing chambers 73 as well as with the blank portion 73a. The click-stops 79 are able to engage with a sprung loaded pin 80, located in a top surface of the delivery portion 75 in the manner shown in Figs. 8 and 9. This allows the user to rapidly and accurately rotate any one of the dosing chambers 73, as well as the blank portion 73a, into alignment with the dosage supply conduit 77. Fig. 10 shows the dosing mechanism 71 mounted to the grinding machine 1 , so that one or more predetermined quantities of material to be ground can be passed from the dosing mechanism 71 into the grinding mechanism 9 to be ground when the grinding mechanism 9 is activated by a user by operation of on/off switch 87. From there, the ground product 82 can pass into a portionised receiver 83, which is aligned with to the outlet port 81. Once the grinding process has finished the ground product

82 can be quickly and easily transferred to another operation, such as using it to brew coffee. In Fig. 10, a portafilter is shown as an example of such a portionised receiver

83 resting on stand 85 below the outlet port 81, ready for use. Referring to Figures 11 to 16, a coffee grinder comprises a generally C-shaped body/ casing 201, of light alloy components, including a base 202 having a platform 203 adapted to support a ground coffee receiving receptacle 270. Behind the platform, a stem 204 extends up and over the base. A cover 205 closes the body and includes a coffee bean inlet funnel 206 over the platform. The components of the body are held together as by screws 207.

A sub-assembly 211 comprising upper and lower component support members 212,214 is arranged in the casing, rigidly screwed 215 at its stem end to the cover 205 and resiliently mounted via bushes 216 and screws 217 to a nose 208 of the stem at the other end via spigots 218. The members 212,214 are screwed together by screws 219. The lower member 214 is formed to receive:

• an electric motor and double reduction gearbox unit 220 at a seat 221 and spigots 222. The unit per se is a standard unit and will not be further described;

• a shaft 223 of an idler gear 224 in mesh with an output pinion of 225 of

gearbox;

• a plain bearing 226 for an upper/outer grinding burr 227. The burr is screwed 228 to a gear 229 in mesh with the idler gear 224 at an effective reduction - typically 4:1 - with respect to the pinion 225

• a location collar 230 holding an outlet funnel 231 for ground coffee 232 to flow down to a receptacle 270 on the platform 203 along a ground coffee flow path 210.

• The upper member 212 is complementarily with the lower member and has:

• an upper location 234 for the shaft 223;

• a passage 235 beneath the funnel 206 for guiding coffee beans into the burrs 227 and 241 along a bean flow path 209;

• a lug 236 extending into the passage; a sleeve 237 integral with the lug and substantially coaxial with the passage 235 and the burr 227; and

• A bean ejector baffle 233 for preventing partially ground coffee bean

fragments from being ejected upwards back out of the coffee bean inlet funnel 206. A shaft 238 is received in the sleeve 237, with the shaft having an anti-rotation tab 239 received in a keyway 240 in the sleeve, whereby the shaft is inhibited from rotation. At its lower end, the shaft has a lower/inner burr 241 splined 242 to it and secured by a large diameter washer 243 with 3 or more location ribs 259 positioned on its outer dia. These ribs locate in the location collar 230, whilst allowing relative vertical movement of the washer and non-rotating lower burr with respect to the rotating upper burr 227. The location collar is held fast with the lower component support member 214 by screws 2301. The location collar engages with the plain bearing 226. Thus the lower burr is held concentrically with the upper burr for uniform coffee bean grinding, when the upper/outer burr is driven by the motor. The burrs and the shaft are all co-axial on a burr axis A-A, passing normally through the burrs. This axis is upright in the coffee grinder in use, with the inlet funnel 206, the passage 235 and the outlet funnel 231 all being aligned on the axis to encourage flow of the beans and the ground coffee through the grinder under gravity.

The shaft 238 and burr 241 are adjustable up and down, for fineness of grind by a lever 244. This is carried at a fulcrum swelling 245 in a recess 246 in the lug 236 and engages via a ball end 247 in a cylindrical recess 248 in the shaft 238. A spring 249 is received in a bore 250 in the upper end of the shaft 238, acting against a closed end 251 of the shaft sleeve 237 to drive the shaft 238 down against the action of the lever 244.

A remote end 252 of the lever is acted on by a cam 253 formed as a spiral on a cam member 254. This has a lower central pin 260 guided by the upper casing upper 212 and is housed in a cam carrier 255 screwed 256 to the sub-assembly opposite from the motor and gearbox unit. The carrier has a slot 257 for locating the lever laterally and an adjustment knob 258 is fast with the cam member. Turning of the knob adjusts the position of the non-rotating inner burr 241 within the outer burr 227.

The adjustment knob 258 is the only one of the components just described which are outside the casing 201. The coffee receptacle, or grind cup, 270 is of "egg cup" shape to provide ease of pouring of the ground coffee into a portafilter of an espresso coffee machine from its tall/narrow shape. It has an outer rim groove 271 to assist inverted location over the portafilter for transferring the ground coffee out of the grind cup into the portafilter filter basket. The grind cup also has a flat circular base 272. This is sized to fit inside the portafilter filter basket for evenly tamping the ground coffee into the portafilter filter basket.

This embodiment is not intended to be restricted to the details of the above described embodiment. For instance the burr axis need not be vertical in use and the inlet and outlet funnels need not be aligned on the axis. The driven upper/outer burr 227 can be journalled on a rotating element bearing as opposed to the plain bearing 226. The arrangement of the idler gear 224 can be replaced by a tooth belt drive. As mentioned elsewhere, the conical burrs can be replaced by flat burrs.

Referring to Figures 17 to 19, shows the same coffee grinder as that described in Figs 11 to 16 apart from a cover 305 which closes the body and includes a coffee bean inlet funnel 306 over the platform. The profile of said coffee bean inlet funnel is concave and works in conjunction with bean ejector baffle 333 to provide a near vertical gap of about 12mm or more to allow the largest coffee beans to enter the passage 335.

The outside diameter of the bean ejector baffle is sized to be just smaller than the centre hole in the cover 305, so as to allow easy fitting of the cover over the gearbox assembly during assembly.

A sub-assembly 311 comprising upper and lower component support members 312,314 is arranged in the casing.

The upper member 312 is complementarily with the lower member and has: a passage 335 beneath the funnel 306 for guiding coffee beans into the burrs 327 and 341 along a bean flow path 309;

lugs 336a and 336b extending into the passage; a sleeve 337 integral with both lugs 336a and 336b and substantially coaxial with the passage 335 and the burr 327;

the bean flow path 309 passing either side of both lugs 336a and 336b and a bean ejector baffle 333 for preventing partially ground coffee bean fragments from being ejected upwards back out of the coffee bean inlet funnel 306.

a shaft guide plate 361 fixedly attached to upper member 312 by two screws 362 and provided with a precision matching bore 364 so as to concentrically locate and guide the lower end of shaft 338.

the two mounting holes in shaft guide plate 361 are sized so as to allow a degree of adjustment before screws 362 are tightened, thus allowing shaft 338 to be concentrically fixed relative to upper/outer burr 327 during final assembly and without the need for precision machining of support members 312,314.

a bore 334 is provided in the open end 351 of sleeve 337 so as to match and accurately align the upper end of shaft 338.

A shaft 338 is received in the sleeve 337, with the shaft having an anti-rotation tab 339 received in a keyway 340 in the sleeve, whereby the shaft is inhibited from rotation. At its lower end, the shaft has the lower/inner burr 341 splined 342 to it and secured by a large diameter washer 343.

The shaft guide plate 361, whilst allowing relative vertical movement of the shaft and non-rotating lower/inner burr 341 with respect to the rotating upper/outer burr 327. The shaft guide plate 361 is held fast relative to the upper component support member 312 by screws 362. A bore 364 in the shaft guide plate precisely engages with the shaft 338. Thus the lower/inner burr is held concentrically with the upper/outer burr for uniform coffee bean grinding, when the upper/outer burr is driven by the motor. The burrs and the shaft are all co-axial on a burr axis A-A, passing normally through the burrs. This axis is upright in the coffee grinder in use, with the inlet funnel 306, the passage 335 and the outlet funnel 331 all being aligned on the axis to encourage flow of the beans 309 and the ground coffee 310 through the grinder under gravity. The shaft 338 and burr 341 are adjustable up and down, for fineness of grind by a lever 344. This is carried at a fulcrum swelling 345 in a recess 346 in the lug 336a and engages via a ball end 347 in a cylindrical recess 348 in the shaft 338. A spring 349 mounted on a spigot on the upper end of the shaft 338, acting against a shoulder 365 of the shaft sleeve 337 to drive the shaft 338 down against the action of the lever 344.

A remote end 352 of the lever is acted on by a cam 353 formed as a spiral on a cam member 354. This has a lower central bore guided by a pin 360 formed in the upper casing upper 312 and is housed in a cam carrier 355 screwed 356 to the subassembly opposite from the motor and gearbox unit. The carrier has a slot 357 for locating the lever laterally and an adjustment knob 358 is fast with the cam member. Turning of the knob adjusts the position of the non-rotating lower/inner burr 341 within the upper/outer burr 327.

The adjustment knob 358 is the only one of the components just described which are outside the casing 301. This embodiment is not intended to be restricted to the details of the above described embodiment. For instance the burr axis need not be vertical in use and the inlet and outlet funnels need not be aligned on the axis. The driven upper/outer burr 327 can be journalled on a rotating element bearing as opposed to the plain bearing 326. The arrangement of the idler gear 324 can be replaced by a tooth belt drive. As mentioned elsewhere, the conical burrs can be replaced by flat burrs.