WO2012069986A1

WO2012069986A1 - Coffee centrifuge

Info

Publication number: WO2012069986A1
Application number: PCT/IB2011/055225
Authority: WO
Inventors: Luca Giorgella
Original assignee: Luca Giorgella
Priority date: 2010-11-23
Filing date: 2011-11-22
Publication date: 2012-05-31

Abstract

A coffee centrifuge for extracting a coffee beverage from coffee solids, includes a rotary holder having a sleeve portion for bounding a space for receiving the coffee solids. A rotor has an outer edge for scraping an inner surface of the sleeve portion and ejecting coffee solids from an opening in the sleeve portion. A coupling, such as a screw coupling, between a drive shaft and the rotor, provides relative axial displacement between the rotor and the rotary holder depending upon the direction of rotation of the drive shaft. Journal means supporting the rotary holder are disposed in a demountable cradle, allowing the holder to be readily removed for cleaning.

Description

COFFEE CENTRIFUGE

Technical field

The present invention relates to a coffee centrifuge for extracting a coffee beverage from coffee solids, such as ground roasted coffee beans.

Background of the Invention

Various elements are employed in coffee centrifuges to remove spent coffee solids and clean the rotary bowl or holder in which the solids are retained. These may include, for instance, pushers, which eject the coffee solids. A water flushing cycle may be employed, or it may be necessary to manually disassemble the machine to some extent for cleaning. US Patent Publication US2010/0266739 describes a coffee centrifuge in which the coffee solids are held in a holder comprising a cylindrical sieve rotated by a motor-driven drive shaft. A screw coupling connects the drive shaft to a pusher, such that rotation of the drive shaft provides axial displacement of the pusher within the cylindrical sieve. Rotation in one direction engages the pusher and cylindrical sieve to rotate together to centrifugally extract the coffee beverage, and rotation in an opposite direction moves the pusher out of the sieve to eject the coffee solids. Non-rotating chambers for receiving the coffee beverage and spent coffee solids are disposed circumferentially about the sieve and pusher and, for cleaning, the entire assembly of the non-rotating chambers, cylindrical sieve and attached pusher can be demounted from the drive shaft. A drawback with this arrangement is that the cylindrical sieve is recessed within the assembly and is difficult to access and clean. It is an object of the present invention to overcome or substantially ameliorate this disadvantage or, more generally, to provide an improved coffee centrifuge.

Disclosure of the Invention

According to one aspect of the present invention there is provided a coffee centrifuge for extracting a coffee beverage from coffee solids, comprising:

a drive shaft rotated about an axis;

a rotary holder having a sleeve portion for bounding a space for receiving the coffee solids, the sleeve portion extending axially to an opening;

journal means supporting the rotary holder for rotation about the axis;

a rotor having an outer edge for scraping an inner surface of the sleeve portion and ejecting coffee solids from the opening in the sleeve portion;

a coupling between the drive shaft and the rotor, such that rotation of the drive shaft provides relative axial displacement between the rotor and the rotary holder, rotation of the drive shaft in one direction engaging the rotor and rotary holder to rotate together, and rotation in an opposite direction axially separating the rotor and rotary holder to eject the coffee solids, and

a cradle in which the journal means is disposed, the cradle being demountably attached to the coffee centrifuge for manual removal.

The cradle may be removed from the apparatus without tools, and when the cradle is removed the rotary holder is not connected to the rotor, or the drive shaft, and thus may be readily removed from the coffee centrifuge. Preferably the axis is substantially upright when in use, and the cradle is lowered to demount it from the coffee centrifuge.

Preferably the cradle is demountably attached to the coffee centrifuge by a latch. For instance, the latch may comprise a latching member resiliently biased into a recess so as to demountably attached the cradle to the coffee centrifuge. Optionally, the latching member may be integral with the cradle, as in the case of a latch member comprising a projection formed on an integral resilient hinge.

Preferably the cradle comprises a first housing for receiving coffee solids ejected from the holder, or a second housing for receiving coffee beverage that has passed from the holder.

Preferably the cradle comprises a first housing for receiving coffee solids ejected from the holder, and a second housing for receiving coffee beverage that has passed from the holder, the second housing having an outlet for dispensing coffee beverage.

Preferably the second housing is formed separately from the first housing, and with the cradle removed from the apparatus the second housing may be extracted from the first housing for cleaning.

Preferably the coffee centrifuge further comprises an inlet for passing coffee solids into the space, the inlet having an annular form and extending about the drive shaft.

Preferably the coffee centrifuge further comprises a conduit for passing water and/or steam through the inlet.

Preferably the journal means comprises a rolling element bearing held in the cradle, such as a ball bearing or roller bearing. The journal means may comprise a plain bearing in the cradle, a bushing or a shell.

Preferably the opening is at a first axial end of the sleeve portion, the rotary holder further comprising a base portion closing a second end of the sleeve portion opposite the opening. Preferably the opening is uppermost.

Preferably the sleeve portion is cylindrical. Preferably the sleeve portion includes apertures through which the coffee beverage is passed. Preferably the apertures comprise a set of apertures arrayed generally in a transverse plane transverse to the axis. Preferably the apertures of the set comprise circumferential slits.

Preferably the rotary holder further comprises an axially extending protrusion for engaging the journal means. Preferably the protrusion is substantially cylindrical and received in a central opening in the journal means.

Preferably one of an axially aligned nub and cooperating nub-receiving aperture are provided in respective ones of an end of the drive shaft and holder.

Preferably a shoulder is formed on an end of the drive shaft for abutting the rotary holder, such that the rotary holder is located axially between the journal means and the shoulder.

Preferably the outer edge of the rotor has a circumferential extent complementary to the inner surface of the sleeve portion.

Preferably the opening is disposed at a first axial end of the sleeve portion and the rotor further comprises a closure for closing the opening.

Preferably the coffee centrifuge further comprises a seal for sealing between a periphery of the closure and the sleeve portion.

Preferably the coffee centrifuge further comprises an aperture in the closure for receiving an elongate neck in which the inlet is disposed.

Preferably the coupling comprises a first part fixed to rotate with the drive shaft, and a second part fixed to rotate with either the rotor or the sleeve, one of the first and second parts comprising an inclined member extending inclined to the axis, and the other of the first and second parts having engagement means engaged with the inclined member. Preferably the inclined member is a helical member, such as a screw thread. The inclined member may comprise an external screw thread and the engagement means a complementary internal screw thread. Preferably the coupling is between the drive shaft and the rotor.

By providing a demountable cradle in which the journal means are disposed, the rotary holder may be readily removed from the coffee centrifuge, allowing the holder to be cleaned separately in a manner not possible with prior art coffee centrifuges of this type.

Brief Description of the Drawings

Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:

Figure 1 is a diagrammatic perspective view of a coffee centrifuge in accordance with a first embodiment of the present invention;

Figure 2 is a diagrammatic exploded perspective view is of a centrifugal pump member of the device shown in Figure 1;

Figure 3 is a diagrammatic perspective view of a rotary holder of the device shown in Figure 1;

Figure 4 is a diagrammatic plan view of the rotary holder shown in Figure 3;

Figure 5 is a diagrammatic perspective view of a cradle of the device shown in Figure 1;

Figure 6 is a diagrammatic plan view of the cradle shown in Figure 5;

Figure 7 is a diagrammatic perspective view of a drive member of the device shown in Figure 1;

Figure 8 is a diagrammatic side view of a housing of the device shown in Figure 1;

Figure 9 is an exploded schematic sectional view in an upright central plane through a coffee centrifuge according to a second embodiment of the invention;

Figure 10 is a schematic sectional view in an upright central plane through the assembled coffee centrifuge of Fig. 9, showing the rotor in a beverage-extracting position, and

Figure 11 is a schematic sectional view in an upright central plane through the assembled coffee centrifuge of Fig. 9, showing the rotor in a waste-ejecting position.

Description of the Preferred Embodiments

Referring to Figures 1-8 of the drawings, there is shown a first embodiment of a coffee centrifuge 10 for extracting a coffee beverage from coffee solids. It will be understood that the present coffee centrifuge 10 may form part of a coffee machine having other components, such as components for receiving coffee solids, and for receiving water for dissolving soluble components as it is passed through the coffee solids; a heating device for heating the water to be passed through the coffee solids; a device such as a pump for transferring water to the coffee centrifuge; electrical and control components required to control operation of the extraction process; a grinder arranged to produce the coffee solids, as from roasted coffee beans; and/or any other components required to carry out the extraction process.

The coffee centrifuge 10 includes a housing assembly 12 arranged to receive a rotor 14, and a rotary holder 16, both of which are rotatable relative to the housing assembly 12 about an axis 90. The coffee centrifuge 10 also includes a drive shaft 20 connected to a motor 22 and arranged to effect rotation of the rotor 14 during use.

The rotor 14 is shown in more detail in Figure 2. The rotor 14 may include a base portion 24 of annular form, having a circumferential edge 91 and a plurality of vanes 26 disposed on the base portion 24. The base portion 24 may be generally planar, extending in a plane (not shown) transverse to the axis 90. The rotor 14 may also include a diverter 28 of generally frusto-conical configuration, which assists in directing coffee solids falling in the axial direction on the rotor 14 to move radially outwardly, and a hub 30 disposed generally centrally of the rotor 14 and engagable with the drive shaft 20 such that rotation of the drive shaft 20 effects rotation of the rotor 14. The rotor 14 may also include a top or closure portion 32 of generally annular configuration connected to the vanes 26, but shown in Figure 2 separate to the vanes 26 for illustrative purposes.

The rotary holder 16 is shown more particularly in Figures 3 and 4. The rotary holder 16 comprises a sleeve portion 42 for bounding a space 93 for receiving the coffee solids. The sleeve portion 42 comprises a plurality of apertures 44 arranged so that fluid passing through the coffee solids during use is able to pass through the sleeve portion 42, but coffee solids are substantially not able to pass through the sleeve portion 42. The sleeve portion 42 has an inner surface 94 complementary to the outer edge 91 and extends axially to an opening 92 at one axial end, and may have a generally circular base portion 40 closing an opposing end. In use, the axis 90 is generally upright and opening 92 is disposed uppermost. The rotary holder 16 may also include a cylindrical, axially extending protrusion 46 disposed generally centrally of the base portion 40 and about which the rotary holder 16 is arranged to rotate during use.

The cradle 18 is shown more particularly in Figures 5 and 6. The cradle 18 includes a recessed portion 50 of generally cylindrical configuration, and a boss 52 provided with a hole or journal 54. The cradle 18 is arranged to receive the rotary holder 16 such that the protrusion 46 of the rotary holder 16 is received in the journal 54 and the rotary holder 16 is able to freely rotate relative to the cradle 18. It will be understood that the recessed portion 50 is sufficiently shallow that the apertures 44 provided in the rotary holder 16 are not obscured by the recessed portion 50 of the cradle 18.

The drive shaft 20 is shown more particularly in Figure 7. The drive shaft 20 may include a section 60 having an end cap 62 provided at a first longitudinal end of the section 60 and an engaging portion 64 provided at a second opposite longitudinal end of the section 60. The engaging portion 64 may be arranged to engage directly or indirectly (e.g. via a gear set) with a drive shaft of the motor 22 such that the motor 22 turns the drive shaft 20. The section 60 extends during use through the hub 30 of the rotor 14 with the end cap 62 being disposed adjacent an outwardly facing surface of the base portion 24 so as to retain the rotor 14 on the drive shaft 20.

The drive shaft 20 may also includes an external helically threaded portion which provides a first coupling part 66, and which may extend from an end of the section 60 adjacent the end cap 62, in this example to a stop location 63 on the section 60 between the end cap 62 and the engaging portion 64. The helically threaded first coupling part 66 engages during use with a guide pin or second coupling part 68 extending through a through hole provided in the rotor 14. The coupling 66, 68 provided by these two coupling parts thereby operatively connects the rotor 14 to the drive shaft 20. The arrangement is such that rotation of the drive shaft 20 in a first direction causes the rotor 14 to move downwardly relative to the drive shaft 20 towards the end cap 62, and rotation of the drive shaft 20 in a second opposite direction causes the rotor 14 to move away from the end cap 62 to the stop location 63.

The housing 12 is shown more particularly in Figure 8. The housing 12 may include an inlet 70 for passing coffee solids into the space 93, a first housing portion 72, and a second housing portion 74. Each of the first and

second housing portions

72, 74 defines a generally cylindrical internal space. As shown more particularly in Figure 2, an intersection between the first and

second housing portions

72, 74 internally of the housing 12 defines a shoulder portion 76 since the internal diameter of the first housing portion 72 is of slightly larger diameter than the internal diameter of the second housing portion 74. The internal diameters of the first and

second housing portions

72, 74 are such that the rotor 14 is receivable in either of the first and

second housing portions

72, 74, but the rotary holder 16 is receivable only in the first housing portion 74 and is prevented from moving axially into the second housing portion 74 by the shoulder portion 76.

The first housing portion 72 may includes a fluid inlet, in this example a water inlet 78, and the second housing portion 74 may includes a waste outlet, in this example a waste coffee solids outlet 80 through which waste coffee solids are ejected during use. The housing 12 also includes an externally screw threaded portion 82 arranged to engage with a corresponding screw threaded portion on the cradle 18. It will be understood that this demountable attachment of the cradle 18 allows easy access without tools to the components inside the housing, particularly to the rotary holder 16 for cleaning purposes.

When the rotor 14 is disposed adjacent the end cap 62, the rotor 14 is disposed inside the rotary holder 16 in a beverage-extracting position, and when the rotor 14 is disposed remotely from the end cap 62, the rotor 14 is disposed in a waste-ejection position with the rotary holder being located adjacent but not inside the rotary holder 16 and inside the second housing portion 74. The coupling 66, 68 enables the rotary holder to be disposed in the beverage-extracting position or in the waste position, and for extraction and waste disposal to be carried out simply by selecting the speed and direction of rotation of the drive shaft 20.

In operation, coffee solids are introduced through the inlet 70, for example from an automated coffee grinding component of a coffee extraction system or apparatus. The coffee solids fall through the inlet 70 into the space 93 and onto the diverter 28 of the rotor 14 and are urged outwardly of the rotor 14 by the diverter 28. The motor 22 then causes the drive shaft 20 to rotate in a first direction. By virtue of the interaction between the guide pin coupling part 68 of the rotor 14 and the helically threaded coupling part 66 of the drive shaft 20, the rotor 14 is disposed in the beverage-extracting position wherein the rotor 14 is located adjacent the end cap 62 of the drive shaft 20 and the rotor 14 is received in the rotary holder 16 in the first housing portion 72. Rotation of the rotor 14 with the rotor 14 in the beverage-extracting position causes the coffee solids to move outwardly of the rotary holder and to be distributed substantially evenly around an internal surface of the sleeve portion 42 of the rotary holder 16.

Heated water is then introduced into the first housing portion 72 through the water inlet 78 whilst the rotor 14 and the rotary holder 16 are rotating which causes the water to be forced through the coffee solids and the apertures 44 in the rotary holder 16, thereby extracting the soluble components from the coffee solids to produce a coffee beverage. After extraction of the coffee beverage, the motor 22 is reversed, turning the drive shaft 20 in a second direction opposite the first direction and, by virtue of the interaction between the guide pin coupling part 68 and the helically threaded coupling part 66, the rotor 14 is caused to move axially from the beverage-extracting position to the waste position along the section 60 away from the end cap 62 to the stop location 63 and into the second housing portion 74. Substantially all of the water introduced into the rotor 14 passes through the bed of coffee solids formed on the surface 94 and, as a consequence, the solids remaining in the rotary holder 16 after extraction is substantially dry. The outer edge 91 of the rotor 14 thus scrapes the complementary inner surface 94, moving the waste coffee solids axially. In the waste position, the rotor 14 is disposed adjacent but not inside the rotary holder 16 and rotation of the rotor 14 causes the waste coffee solids to be expelled from the rotor 14 through the waste outlet 80. The cradle 18 can be unscrewed manually from the housing, and with the cradle 18 removed, the rotary holder 16 may drop out, as it is not connected to the rotor, or the drive shaft, and thus may be readily removed from the coffee centrifuge for cleaning.

A second embodiment of the invention is shown in Figs 9-11, wherein like parts are designated by like numerals. Referring to Fig. 9, a funnel 202 fixed to a frame of the coffee centrifuge has a cylindrical neck 203 with an inlet 204 for passing coffee solids into the space 93, the inlet 204 having an annular form and extending about the drive shaft 20. A conduit 206 is provided for passing water through the inlet 204. A tapered mounting part 207 may be fixed to the frame 205.

In this embodiment the annular base portion 24 and closure portion 32 may be connected by spacers 126, and an a sealing ring 200 may be disposed on the closure portion 32, for sealing the closure portion 32 to the rotary holder 16. The sealing ring may be received in a peripheral recess and disposed for engagement with the cylindrical inner surface 94 of the sleeve portion 42. The closure portion 32 may comprise a frusto-conical part 201 projecting away from the base portion 24 to enlarge the internal space 93 bounded by the rotor 14 and the holder 16. The opening 95 in the closure portion 32 receives the cylindrical neck 203 of the funnel. The

coupling

168, 66 comprises the external thread 66 on the drive shaft 20 and the complementary internal thread 168 on the rotor 14. An axially aligned nub 208 may project from the end of the drive shaft 20, forming a shoulder 212 adjacent the end cap 62.

In the holder 16 has a bowl-like form with a nub-receiving aperture 209, complementary to the nub 208, may be provided. The shoulder 212 formed by the end cap 62 abuts the rotary holder 16, such that the rotary holder is located axially between the journal 54 and the shoulder 212. The sleeve portion 42 includes apertures in the form of circumferential slits 188 through which the coffee beverage is passed. A set of slits 188 extend circumferentially and are arrayed generally in a transverse plane 211, which extends transverse to the axis 90. Abutment faces 227, 228 are provided on an outer side of the base portion 24 of the rotor 14 and an opposing side of the base portion 40 of the holder 16.

The

cradle

220, 221 is an assembly, comprising a first housing 220 for receiving coffee solids ejected from the holder 16, and a second housing 221 for receiving coffee beverage that has passed from the holder 16. The journal 54 may comprise a double ball bearing held in the second housing 221. The second housing 221 encloses a volume extending about the holder 16 from a little above the plane 211 of the slits 188 down to outlets 222 to which the coffee beverage can drain for dispensing. A cylindrical, axially extending baffle 223 may be provided in the second housing 221 for directing the flow of coffee beverage. The second housing 221 may be formed separately from the first housing 220, and cooperating

features

224, 225 may locate and support the second housing 221 generally within the first housing 220, such that when assembled the outlets 222 pass through an opening 226 in the base of the first housing 220.

A latch (not shown) on the second housing 220 of the

cradle

220, 221 may be provided to demountably attach the

cradle

220, 221 to the frame 205, via the mounting part 207. The latch may comprise a latching member integral with the

cradle

220, 221 and resiliently biased into a recess (not shown) in the mounting part so that the

cradle assembly

220, 221 is readily demountable.

The operation of the coffee centrifuge is shown in Figs 10 and 11, showing the coffee extracting and waste-ejecting positions respectively. Referring to Fig. 10, the coffee solids (not shown) drop through the funnel 202 and from the inlet 204 into the space 93. To move the rotor 14 to the beverage-extracting position shown, the motor 22 turns the shaft 20 in a first direction. When the abutment faces 227, 228 abut as illustrated, torque is transferred from the rotor 14 to the holder 16 and the centrifugal action produces a filter bed of coffee solids 230 held against the inner wall 94. Hot water is then introduced through the conduit 206. The slits 188 are disposed adjacent the closure portion 32 near the top of the space 93 such that water must generally travel up through the bed 230 before the water, now including dissolved coffee elements to form a coffee beverage, can pass from the holder 16. The coffee beverage passes from the holder 16 into the first housing 220 and drains to the outlets 222.

To then eject the waste coffee solids the shaft 20 is turned in a second direction opposite the first direction, as by reversing the motor 22. Relative rotation between the

coupling parts

66, 168 displaces the rotor 14 relative to the holder 16, separating the abutment faces 227, 228 of rotor and rotary holder. As the rotor 14 moves axially, the base portion 24 removes the coffee bed 230, ejecting the coffee solids through the opening 92, the rotation throwing these solids outward into the first housing 220 where they are collected. The rotor 14 may move axially upwardly to the waste-ejecting position shown in Fig. 11, where its further upward travel may be limited by a stop (not shown) fixed to the drive shaft 20 and against which the rotor abuts. Referring to Fig. 11, in this position a planar, transverse face of the base portion 24 may be generally aligned with a rim 231 of the holder 16.

A reverse-rotation-preventing device (not shown), such as a one-way clutch or ratchet assembly, may be engaged with the holder 16, to prevent the holder 16 from rotating in the second direction.

For the removal of spent coffee solids and cleaning, the

cradle

220, 221 is demounted. Firstly, the latches (not shown) connecting the

cradle

220, 221 to the machine are released, the

cradle

220, 221 together with the holder 16 supported therein. With the

cradle

220, 221 removed the holder 16 can be pulled out of the journal 54 for cleaning. The second housing 221 may be extracted from the first housing 220 for cleaning.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

Claims

A coffee centrifuge for extracting a coffee beverage from coffee solids, comprising:

a drive shaft rotated about an axis;

a rotary holder having a sleeve portion for bounding a space for receiving the coffee solids, the sleeve portion extending axially to an opening;

journal means supporting the rotary holder for rotation about the axis;

a rotor having an outer edge for scraping an inner surface of the sleeve portion and ejecting coffee solids from the opening in the sleeve portion;

a coupling between the drive shaft and the rotor, such that rotation of the drive shaft provides relative axial displacement between the rotor and the rotary holder, rotation of the drive shaft in one direction engaging the rotor and rotary holder to rotate together, and rotation in an opposite direction axially separating the rotor and rotary holder to eject the coffee solids, and

a cradle in which the journal means is disposed, the cradle being demountably attached to the coffee centrifuge for manual removal.
The coffee centrifuge of claim 1 wherein the cradle is demountably attached to the coffee centrifuge by a latch.
The coffee centrifuge of claim 1 or claim 2 wherein the cradle comprises a first housing for receiving coffee solids ejected from the holder, or a second housing for receiving coffee beverage that has passed from the holder.
The coffee centrifuge of claim 1 or claim 2 wherein the cradle comprises a first housing for receiving coffee solids ejected from the holder, and a second housing for receiving coffee beverage that has passed from the holder, the second housing having an outlet for dispensing coffee beverage.
The coffee centrifuge of claim 4 wherein the second housing is formed separately from the first housing, and with the cradle removed from the apparatus the second housing may be extracted from the first housing for cleaning.
The coffee centrifuge of any of the preceding claims further comprising an inlet for passing coffee solids into the space, the inlet having an annular form and extending about the drive shaft.
The coffee centrifuge of any of the preceding claims further comprising a conduit for passing water and/or steam through the inlet.
The coffee centrifuge of any of the preceding claims wherein the journal means comprises a rolling element bearing held in the cradle.
The coffee centrifuge of any of the preceding claims wherein the opening is at a first axial end of the sleeve portion, the rotary holder further comprising a base portion closing a second end of the sleeve portion opposite the opening.
The coffee centrifuge of any of the preceding claims wherein the sleeve portion is cylindrical.
The coffee centrifuge of any of the preceding claims wherein the sleeve portion includes apertures through which the coffee beverage is passed.
The coffee centrifuge of claim 11 wherein the apertures comprise a set of apertures arrayed generally in a transverse plane transverse to the axis.
The coffee centrifuge of claim 11 wherein the apertures of the set comprise circumferential slits.
The coffee centrifuge of any of the preceding claims wherein the rotary holder further comprises an axially extending protrusion for engaging the journal means.
The coffee centrifuge of claim 14 wherein the protrusion is substantially cylindrical and received in a central opening in the journal means.
The coffee centrifuge of any of the preceding claims wherein one of an axially aligned nub and cooperating nub-receiving aperture are provided in respective ones of an end of the drive shaft and holder.
The coffee centrifuge of any of the preceding claims wherein a shoulder is formed on an end of the drive shaft for abutting the rotary holder, such that the rotary holder is located axially between the journal means and the shoulder.
The coffee centrifuge of any of the preceding claims wherein the outer edge of the rotor has a circumferential extent complementary to the inner surface of the sleeve portion.
The coffee centrifuge of any of the preceding claims wherein the opening is disposed at a first axial end of the sleeve portion and the rotor further comprises a closure for closing the opening.
The coffee centrifuge of any of the preceding claims further comprising a seal for sealing between a periphery of the closure and the sleeve portion.
The coffee centrifuge of any of the preceding claims further comprising an aperture in the closure for receiving an elongate neck in which the inlet is disposed.
The coffee centrifuge of any of the preceding claims wherein the coupling comprises a first part fixed to rotate with the drive shaft, and a second part fixed to rotate with either the rotor or the sleeve, one of the first and second parts comprising an inclined member extending inclined to the axis, and the other of the first and second parts having engagement means engaged with the inclined member.
The coffee centrifuge of claim 22 wherein the inclined member is a helical member.
The coffee centrifuge of any of the preceding claims wherein the inclined member comprise an external screw thread and the engagement means a complementary internal screw thread.
The coffee centrifuge of any of the preceding claims wherein the coupling is between the drive shaft and the rotor.
A coffee centrifuge having any novel combination of features disclosed herein.
A coffee centrifuge substantially as hereinbefore described with reference to the accompanying drawings.