Device for grinding coffee grains

Abstract

Device for grinding coffee grains, comprising: a device body (11) in which a grinding chamber (13) is formed, a grinding member (12) arranged in the grinding chamber (13) and configured to grind coffee grains and to produce a ground coffee powder; a discharge conduit (20) configured to discharge the ground coffee powder coming from the grinding chamber (13) towards the outside of said device; a powder removing system configured to remove ground coffee powder from the discharge conduit (20), comprising a vibrator member (30) mounted on the discharge conduit (20) and operable to apply a controlled vibration to the discharge conduit (30).

Description

[0001] Device for grinding coffee grains

[0002] The present invention relates to a device for grinding coffee grains, comprising:

[0003] - a device body in which a grinding chamber is formed,

[0004] - a grinding member arranged in the grinding chamber and configured to grind coffee grains and produce a ground coffee powder;

[0005] - a discharge conduit configured to discharge the ground coffee powder coming from the grinding chamber towards the outside of said device, the discharge conduit comprising a proximal end connected to the device body and a distal end in which a discharge opening is formed;

[0006] - powder removing means configured to remove ground coffee powder from the discharge conduit, the powder removing means comprising a vibrator member mounted on the discharge conduit and operable to apply a controlled vibration on the discharge conduit.

[0007] A coffee containing beverage is known to be prepared by using coffee powder obtained by means of grinding coffee grains. The beverage is generally obtained by means of extraction, i.e. percolation using pressurized boiling water. In particular, machines for producing beverages containing coffee are known which are provided with a water tank from which, by means of a pump, said water is delivered at high pressure to a heating unit. From the latter, hot water and / or water vapor are obtained, which are used within an extraction unit where they are percolated through the coffee powder in order to produce the coffee containing beverage.

[0008] It is possible to use coffee powder obtained from grinding coffee grains of the same variety, or to use a mixture of coffee powders obtained from grinding coffee grains of different varieties.

[0009] In grinding devices, in particular those used in so-called “beans to cup” machines, equipped to grind the coffee grains and produce the beverage from the coffee thus ground, the need is felt to prevent contamination between mixtures of ground coffee formed by different coffee selections. In this regard, different solutions have been proposed for removing the powder from the grinding member or transit chamber, such as scraping devices, fans, vibrator devices or air blower / suction devices.

[0010] In some components of the grinding device, such as in particular the discharge conduit into which the coffee powder may be packed, some of the known solutions may be inadequate to produce a sufficient level of removal.

[0011] One object of the present invention is to make a device that is at least in part capable of overcoming the drawback described above.

[0012] This and other objects are achieved according to the invention with a device of the type initially defined, wherein the proximal end of the discharge conduit is coupled to the device body through a pin or joint through which the discharge conduit is swingable with respect to the device body.

[0013] By virtue of this arrangement, the vibrator member is able to impart an effective shaking to the discharge conduit, so as to cause a substantial removal of the packed ground coffee powder from the discharge conduit. This removal may take place due only to the vibration applied by the vibrator member, or in cooperation with other devices present in the grinding device.

[0014] Further features and advantages of the invention will become clear from the detailed description that follows, given purely by way of non-limiting example and with reference to the accompanying drawings, wherein:

[0015] Fig. 1 is a perspective view of a grinding device according to the invention;

[0016] Fig. 2 is a further perspective view, wherein a part of the device of Fig. 1 is shown in exploded view;

[0017] Fig. 3 is a sectional view of the device of Fig. 1, taken at a vertical sectional plane;

[0018] Fig. 4 is a sectional view of the device of Fig. 1, taken at a horizontal sectional plane;

[0019] Fig. 5 is a side elevation view of the device in Fig. 1; and

[0020] Fig. 6 and 7 are views showing respective variants. The figures show a grinding device, denoted as a whole with 10. This device may be part of a so-called “beans to cup” machine, capable of both grinding coffee grains and producing a beverage from the coffee powder thus ground. According to an alternative embodiment, the grinding device could form an autonomous entity that is separate from a machine for producing coffee -based beverages.

[0021] The grinding device 10 comprises a device body 11, wherein there are housed those components that are provided for the operation thereof, such as, for example, a grinding member 12 (partially indicated in Fig. 3), an electric motor, a transmission that dynamically connects the grinding member to the electric motor, and a circuit board for controlling the electric motor (not shown).

[0022] In particular, a grinding chamber 13 is obtained inside the device body 11, which is visible in Fig. 3 and 4. Such grinding chamber 13 opens aloft towards the outside of the device body 11, through a feed opening 14. It is possible, by means of the feed opening 14, to gravity feed coffee grains to be ground into the grinding chamber 13. The feed opening 14 may be coupled to a dosing device (not shown) by means of which it is possible to feed predetermined quantities of coffee grains to the grinding chamber 13.

[0023] The grinding member 12 is arranged within the grinding chamber 13, which grinding member is configured to grind coffee grains and to produce a ground coffee powder. The grinding member is at least partially able to rotate around an axis indicated with z in the figures, but the specific constitution thereof is not essential for the purposes of the invention. In the example shown, the grinding member 12 comprises a movable grinding member 12a rotatable around the rotation axis z and a fixed grinding member 12b that is integral to the device body 11. In some figures, a rotation shaft 12c is also visible, rotatably integral with the movable grinding machine 12a.

[0024] A bottom portion 15 of the grinding chamber 12 is arranged directly at the outlet of the grinding member 12 and therebelow. This bottom portion 15 is configured to receive ground coffee powder from the grinding member 12. A mounting seat 16 is further formed in the device body 11 at the bottom portion 15 of the grinding chamber 13. The mounting seat 16 is in communication with the bottom portion 15 of the grinding chamber 13. A discharge conduit 20 is mounted at the mounting seat 16, configured to discharge ground coffee powder from the grinding chamber 13 towards the outside of the grinding device 10.

[0025] In the example shown, a rotating element 17 is associated with the grinding member 12 to facilitate the expulsion of the ground coffee powder toward the discharge conduit 20. The rotating element 17 may be connected to the rotating part of the grinding member 12 and may rotate integrally therewith. The rotating element 17 may be arranged under the grinding member 12 at the bottom portion 15 of the grinding chamber 13. The rotating element 17 may be equipped with blades. According to one embodiment, the grinding member 12 and / or the rotating element 17 may be rotated in a rotation direction that is inverted from the rotation direction provided for grinding the coffee grains in order to facilitate the expulsion of the ground coffee powder towards the discharge conduit 20.

[0026] The discharge conduit 20 comprises a proximal end 10a connected to the device body 11 and a distal end 20b in which a discharge opening 20d is obtained. By means of the discharge opening 20d, the ground coffee powder may be discharged into a container or filter, depending on the circumstances of application of the device described herein.

[0027] The discharge conduit 20 defines a channel surrounded by a wall 20c of the discharge conduit 20. Such wall 20c comprises a bottom wall 20c’ inclined downwards, which extends from the proximal end 20a to the distal end 20b of the discharge conduit and therefore acts as a chute for the ground coffee powder. According to a plan view, the discharge conduit extends from the grinding chamber 13 tangentially with respect to the axis of rotation z of the grinding member 12, with a concordant orientation with respect to the grinding rotation direction of the coffee grains. This arrangement facilitates the expulsion of the ground coffee powder from the grinding chamber 13. In the event that the grinding device is of the type operable for inverting the rotation direction of the grinding member and / or the related rotating element, the discharge conduit 20 may optionally be arranged in a concordant orientation with respect to the inverted rotation direction. Other arrangements of the discharge conduit are possible, for example in a radial / transverse or perpendicular downward direction.

[0028] From a construction point of view, the discharge conduit 20 comprises a conduit shell 21 and a conduit cover 22 mounted on the conduit shell 21 at the distal end 20b of the discharge conduit 20. The proximal end 20a and the wall 20c of the discharge conduit 20 are formed on the conduit shell 21. At the distal end 20b of the discharge conduit 20, the conduit shell 21 comprises a flange portion 21b. By means of such flange portion 21b, the conduit cover 22 is fastened to the conduit shell 21.

[0029] A passage opening 23 is formed through the conduit cover 22 in communication with the channel defined by the conduit shell 21. A discharge shell 24 is mounted distally on the conduit cover 22 about the passage opening 23. The discharge shell 24 cooperates with a distal surface of the conduit cover 22 to define a vertically extending discharge channel, which is in communication with the passage opening 23 and ends at the bottom with the discharge opening 20d.

[0030] A membrane 25 made of deformable material, for example, silicone or other elastomeric material, is interposed between the flange portion 21b of the conduit shell 21 and the conduit cover 22. A floating flap 25a peripherally delimited by a slit 25b formed through the membrane 25 is formed on the membrane 25. Such floating flap 25a acts as a tilting hatch that allows the release of ground coffee powder to be controlled, which passes from the channel defined by the conduit shell 21 to the passage opening 23, allowing the dusting phenomenon of the powder to be contained. The slit 25b defining the floating flap 25a may have different shapes, but a U-shaped slit is considered to ensure optimal operation.

[0031] The discharge conduit 20 further comprises a powder removing system configured to remove ground coffee powder from the discharge conduit 20. Such powder removing system may be operated by a control unit of the grinding device, for example between one grinding process and the other, in particular in the event that it is intended to change the selection of coffee grains to be ground. The powder removing system comprises a vibrator member 30 mounted on the discharge conduit 20 and operable to apply a controlled vibration to the discharge conduit 20. The vibrator member 30 is an electrically operated device and may be mounted in any part of the discharge conduit 20. Preferably, the vibrator member 30 is mounted at the distal end 20b of the discharge conduit 20, but could be mounted at the proximal end 20a of the discharge conduit 20, or at an intermediate point between the proximal end 20a and the distal end 20b. In particular, the vibrator member 30 comprises an electric motor 30a on the shaft on which an unbalanced mass 30b is fitted, the rotation of which generates vibrations. Several unbalanced masses 30b may possibly be fitted to the electric motor 30a. Furthermore, there may be multiple vibrator members 30 mounted at various points of the discharge conduit 20.

[0032] In the example shown, the vibrator member 30 is clamped between the conduit shell 21 and the conduit cover 22, more precisely between the flange portion 21b of the conduit shell 21 and the conduit cover 22. In particular, the vibrator member 30 is clamped between a first clamping portion 31 formed peripherally on the flange portion 21b of the conduit shell 21 and a second clamping portion 32 formed peripherally on the conduit cover 22.

[0033] The proximal end 20a of the discharge conduit 20 is inserted into the mounting seat 16 formed in the device body 11. In particular, the proximal end 20a of the discharge conduit 20 is fastened to the mounting seat 16 by means of fastening elements 41, such as a pair of screws, which define a rotation pin that allows the discharge conduit to oscillate vertically with respect to the device body 11. A gasket 40 made of deformable material, e.g., silicone or other elastomeric material, is inserted between an outer surface 20’ of the proximal end 20a of the discharge conduit 20 and an inner surface 16’ of the mounting seat 16, which gasket makes localized contact between the proximal end 20a of the discharge conduit 20 and the mounting seat 16. For the remainder of the extension of the mounting seat 16 in the longitudinal direction of the discharge conduit 20, there remains a gap h between the outer surface 20’ of the proximal end 20a of the discharge conduit 20 and the inner surface 16’ of the mounting seat 16, which allows limited oscillations of the discharge conduit 20 with respect to the device body 11. The arrangement described above improves the effect of the vibrations imparted by the vibrator member 30. In particular, the system described above is comparable to a mass-spring-damper system which may be optimized by analyzing the correlation between the oscillation frequency, oscillation amplitude and dust discharge effectiveness.

[0034] According to a variant shown in Fig. 6, the proximal end of the discharge conduit 20 may be mounted on a tubular socket 16” protruding from the device body 11 and in communication with the grinding chamber. In this variant, there would still be a fastening to the tubular socket by means of fastening elements which define a rotation pin 41’, which allows the discharge conduit to oscillate vertically with respect to the device body 11. A gasket (not shown) would be inserted between an inner surface of the proximal end of the discharge conduit and an outer surface of the tubular socket. According to a further variant illustrated in Fig. 7, the connection between the discharge conduit and the device body could be made by means of a sleeve 41” made of deformable material, having a first end fitted on a tubular socket protruding from the device body and a second end fitted on the outer surface of the proximal end of the discharge conduit, and which would form an oscillation joint between the discharge conduit 20 and the device body 11.

Claims

CLAIMS1. Device for grinding coffee grains, comprising:- a device body (11) in which a grinding chamber (13) is formed,- a grinding member (12) arranged in the grinding chamber (13) and configured to grind coffee grains and produce a ground coffee powder;- a discharge conduit (20) configured to discharge the ground coffee powder coming from the grinding chamber (13) towards the outside of said device, the discharge conduit (20) comprising a proximal end (20a) connected to the device body (11) and a distal end (20b) in which a discharge opening (20c) is formed;- powder removing means configured to remove ground coffee powder from the discharge conduit (20), the powder removing means comprising a vibrator member (30) mounted on the discharge conduit (20) and operable to apply a controlled vibration to the discharge conduit (30), characterized in that the proximal end (20a) of the discharge conduit (20) is coupled to the device body (11) through a hinge pin or spherical joint (41, 41’, 41”) through which the discharge conduit (20) is swingable with respect to the device body (11).

2. Device according to claim 1, wherein the vibrator member (30) comprises an electric motor (30a) on whose shaft an unbalanced mass (30b) is fitted, which rotation generates said controlled vibration.

3. Device according to claim 1 or 2, wherein, when viewed from a plan view, the discharge conduit (20) extends from the grinding chamber (13) tangentially with respect to a rotation axis (z) of the grinding member (12).

4. Device according to any of the preceding claims, wherein the vibrator member (30) is arranged at the distal end (20b) of the discharge conduit (20).

5. Device according to any of the preceding claims, wherein the discharge conduit (20) comprises a downwardly inclined bottom wall (20c’) extending from the proximal end (20a) to the distal end (20b) of the discharge conduit (20).

6. Device according to any of claims from 4 to 6, wherein the discharge conduit (20) comprises a conduit shell (21) and a conduit cover (22) mounted on the conduit shell (21) at the distal end (20b) of the discharge conduit (20), and wherein the vibrator member (30) is clamped between the conduit shell (21) and the conduit cover (22).

7. Device according to claim 6, wherein the conduit cover (22) has a passage opening (23), wherein the discharge conduit (20) comprises a discharge shell (24) distally mounted on the conduit cover (22) around the passage opening (23), said discharge shell cooperating with the conduit cover (22) to define the discharge opening (20c) in communication with the passage opening (23).

8. Device according to claim 7, wherein a membrane (25) of deformable material is interposed between the conduit shell (21) and the conduit cover (22), a floating flap (25a) being formed on the membrane (25), the floating flap being delimited by a slit (25b) formed through the membrane (25).

9. Device according to any of the preceding claims, wherein the proximal end (20a) of the discharge conduit (20) is inserted in a mounting seat (16) formed in the device body (11), wherein a gasket (40) is inserted between an outer surface (20’) of the proximal end

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