Device for grinding coffee beans

Abstract

Device for grinding coffee beans, comprising a device body (11) with a feed opening (14), and a dosing system (20) comprising an interface (21) coupled to the device body (11), wherein the interface (21) is configured to support a container (30) for coffee beans and defines a through hole (22) aligned with the feed opening (24) to form a passage for the coffee beans to fall from the container (30) to the grinding chamber (13); and a shutter closing unit (25) having a plurality of shutter blades (26, 27) slidable between an opening position and a closing position. A grinder shaft (12c, 12c') extends axially until up to a plane defined by the shutter blades (26, 27), wherein, in the closing position, respective leading edges (26a, 27a) of the shutter blades (26, 27) cooperate to delimit a residual hole (28) receiving an upper end of the grinder shaft (12c, 12c').

Description

[0001] Device for grinding coffee beans

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

[0003] - a device body wherein a grinding chamber is formed, the grinding chamber opening aloft towards the outside of the device body, through a feed opening;

[0004] - a grinder shaft arranged within the grinding chamber and rotating about a rotation axis, the grinder shaft being arranged coaxially with the feed opening;

[0005] - a dosing system, comprising an interface coupled to the device body, wherein the interface is configured to support a container for coffee beans and defines a through hole that is aligned with the feed opening to form a passage for the coffee beans to fall from the container to the grinding chamber; a shutter closing unit having a plurality of shutter blades which are slidable between an opening position and a closing position for selectively allowing or blocking a flow of coffee beans through said passage; and an actuator operable to move the plurality of shutter blades with respect to the passage.

[0006] A coffee containing beverage is known to be prepared by using ground coffee obtained by means of grinding coffee beans. 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 container wherefrom, by means of a pump, the water itself 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 ground coffee in order to produce the coffee containing beverage.

[0007] It has been observed that at the end of the dosing operation when the shutter closing unit closes, coffee beans may become lodged between the shutter blades, thereby resulting in sub-optimal functioning of the dosing system. In particular, the upper end of the grinder shaft constitutes an obstacle to falling coffee beans, which may cause some beans to be in a position, when the shutter blades are closed, that interferes with the closing movement of the shutter blades, thereby preventing the complete closure of the latter.

[0008] One object of the present invention is to implement a solution that is at least in part capable of overcoming the drawback described above.

[0009] This and other objects are achieved according to the invention with a device of the type initially defined, wherein the grinder shaft extends axially until a plane defined by the shutter blades, wherein, in the closing position, respective leading edges of the shutter blades cooperate to delimit a residual hole receiving an upper end of the grinder shaft.

[0010] By virtue of the fact that the grinder shaft extends up to the plane defined by the shutter blades, those coffee beans that may be hindered from falling by the grinder shaft come to lie above the shutter blades, and do not therefore prevent the complete closure of the latter.

[0011] 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:

[0012] Figure 1 is a perspective view of a multi-container dosing system;

[0013] Figure 2a is an exploded view of the dosing system of Figure 1;

[0014] Figures 2b and 2c are cross-sectional perspective views of the dosing system coupled to a grinding device, wherein the dosing system is shown in two different operating positions;

[0015] Figure 3a is a perspective view of a detail of the dosing system;

[0016] Figure 3b is a perspective view of a detail of the dosing system, coupled to the grinding device;

[0017] Figure 4 is a plan view from below of the dosing system;

[0018] Figure 5 is a sectional view of the dosing system;

[0019] Figure 6 is a perspective view of a container of the dosing system;

[0020] Figures 7 and 8 are plan views of the dosing system in an opening position and a closing position respectively.

[0021] With reference to Figures 1 and 2a, a dosing system is indicated as a whole with the numeral 20. In the example shown, this is a multi-container system, but it could also be a single container system.

[0022] The dosing system 20 comprises an interface 21 configured to be coupled to a grinding device 10 (shown partially in Figures 2b and 2c) as part of a so-called "beans to cup" machine, capable of both grinding coffee beans and producing a beverage from the ground coffee. According to one embodiment, the coupling between the interface 21 and the grinding device 10 is implemented by means of a support structure (not shown) of the "beans to cup" machine, whereupon the dosing system 20 and the grinding device 10 are mounted. According to another embodiment, the coupling between the interface 21 and the grinding device 10 is direct, and the dosing system 20 is therefore mounted directly onto the grinding device 10.

[0023] 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, 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).

[0024] In particular, a grinding chamber 13 is formed inside the device body 11. 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 beans to be ground into the grinding chamber 13.

[0025] The grinding member 12 is arranged within the grinding chamber 13, which grinding member is configured to grind coffee beans and to produce a ground coffee powder. The grinding member is at least partially able to rotate about 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 about the rotation axis z and a fixed grinding member 12b that is integral to the device body 11. Also visible in Figures 2b and 2c is a grinder shaft 12c that is rotationally integral with the movable grinding member 12a and arranged coaxially with the feed opening 14. The grinder shaft 12c comprises an axial extension 12c', the function of which will be described below. The axial extension 12c' may be an element that is screwed or otherwise mounted onto an upper end of the grinder shaft 12c’. Alternatively, the axial extension 12c' may be a part of the grinder shaft 12c, made in one piece with the rest of the grinder shaft 12c. The axial extension 12c' may have directional shapes that facilitate the descent of the beans. For example, the axial extension 12c' may be tapered and / or provided with a helical structure on the outer lateral surface thereof.

[0026] The interface 21 of the dosing system 20 is configured to support at least one container 30 for coffee beans and defines a through hole 22 configured to be aligned with the feed opening 14 of the grinding device 10 to form a passage for the coffee beans to fall from the container 30 to the grinding chamber 13 of the grinding device 10.

[0027] In the example shown, the interface 21 comprises a main plate 23 and a guide element 24 mounted on the main plate 23. On a lower face 23a of the main plate 23 (see Figure 4) a coupling formation 23b is formed, which is arranged around the through hole 22, and wherethrough the interface 21 may be coupled to the feed opening of the grinding device. The guide element 24, arranged on an upper face 23c of the main plate 23, has an edge 24a which extends in a circumferential arc, wherealong a guide formation 24b is formed, the object of which will be described below. A pair of cap receiving seats 23d and a blade seat 23e are also obtained on the upper face 23c of the main plate 23, the purpose of which will be described below.

[0028] The dosing system 20 further comprises a shutter closing unit 25 having a plurality of shutter blades which are slidable between an opening position and a closing position for selectively allowing or blocking a flow of coffee beans through the passage defined by the through hole 22. In the illustrated example, the plurality of shutter blades consists of two shutter blades indicated with 26 and 27 which are arranged in the blade seat 23e. The opening position of the shutter blades 26, 27 is represented, for example, in Figures 1, 2c, 3 and 7, whilst the closing position of the shutter blades 26, 27 is represented in Figures 2b and 8.

[0029] The shutter blades 26, 27 are hinged upon the interface 21, more precisely upon the main plate 23, at the same rotation pin 23f that defines a vertical rotation axis zi of the shutter blades 26, 27 (shown in Figures 7 and 8). The shutter blades 26, 27 have respective leading edges 26a, 27a which, in the closing position of the shutter blades, abut against each other. Said leading edges 26a, 27a, in the closing position of the shutter blades 26, 27, cooperate to delimit a residual hole 28. To this end, respective notches delimiting complementary portions of the residual hole 28 are formed on the leading edges 26a, 27a. Preferably, the residual hole 28 has a flared edge to direct the beans along the direction of fall.

[0030] As may be seen in Figures 2a, 2b and 3b, by virtue of the axial extension 12c', the grinder shaft 12c extends axially (at least) until a plane defined by the shutter blades 26, 27. In the closing position of such shutters, the residual hole 28 delimited by the respective leading edges of the shutter blades 26, 27 receives the upper end of the grinder shaft 12c. For clarity, in Figure 3b, one of the shutter blades has been removed.

[0031] The shutter blades 26, 27 have respective peripheral edges 26b, 27b which extend in a circumferential arc and which are slidingly coupled to an edge 23g of the lamella seat 23e. A male-female coupling between the peripheral edges 26b, 27b of the shutter blades 26, 27 and the edge 23g of the blade seat 23e holds the shutter blades 26, 27 in the vertical direction.

[0032] A first blade 26 of the pair of shutter blades 26, 27 comprises a first portion 26c delimited aloft by a first top surface 26d and at least one second portion 26e delimited aloft by a second top surface 26f recessed with respect to the first top surface 26d. A second blade 27 of the pair of shutter blades 26, 27 is capable of sliding on the second top surface 26f of the first blade 26 and having a top surface 27g flush with the first top surface 26d of the first blade 26. Furthermore, the top surface 27g of the second blade 27 and the first top surface 26d of the first blade 26 are arranged flush with the upper surface 23c of the main plate 23.

[0033] The dosing system 20 further comprises an actuator 29' that is operable for moving the plurality of shutter blades 26, 27 in relation to the passage defined by the through hole 22. In the example shown, the actuator 29' is an electrically driven linear actuator which moves the shutter blades 26, 27 through a transmission 29. A linear actuator is preferable to a rotating actuator insofar as it allows for more precise control of the movement of the shutter blades 26, 27.

[0034] To this end, a movable element 29a' of the actuator 29' is fixed to a fork element 29a of the transmission 29, slidingly coupled to the lower surface 23a of the main plate 23. Each of the arms of the fork element 29a is coupled to a relevant rocker arm 29b pivoted to the lower surface 23 a of the main plate 23. In particular, each rocker arm 29b comprises a proximal end provided with a pin 29c that is slidingly coupled to a groove 29d formed on a distal end of a relevant arm of the fork element 29a. Each rocker arm 29b furthermore comprises a distal end provided with a groove 29e slidingly coupled to a pin 29f that is integral with a relevant shutter blade 26, 27. The pins 29f of the shutter blades 26, 27 are guided along grooves 23h obtained through the main plate 23. The actuator and the transmission, which allow the shutter blades to move, may be different from those described above.

[0035] The coffee beans container 30 essentially comprises a main body 31 and a neck 32 extending from one end of the container 30. An opening is made at the neck 32 of the container 30 in such a way as to allow coffee beans to be loaded into the container 30 when the latter is in the upright position, and to allow said coffee beans to be discharged by gravity out of the container when the container is in the inverted position shown in the figures, wherein the opening of the container is arranged at the lower end of the container 30. According to one embodiment, not shown, the opening for loading and the opening for unloading may be distinct, for example arranged at opposite ends of the container. The example shows a container having a circular cross section. Such shape is not essential to the invention it being possible to have other shapes. The opening of the container 30 is closed by a cap 33 fixed to the neck 32 of the container 30. The cap 33 has a plate shape and is configured to be slidingly inserted into a relevant cap receiving seat 23d. To this end, the lateral edges 33a of the cap 33 are slidingly coupled to respective edges 23d’ of the cap receiving seat 23d. A malefemale coupling between the lateral edges 33a of the cap 33 and the edges 23d’ of the cap receiving seat 23d holds the cap 33 in the vertical direction. The cap 33 is fixed to the neck 32 by means of a pair of elastic flaps 33b protruding vertically from the cap 33 and extending in a transverse direction with respect to the direction of extension of the lateral edges 33a of the cap 33. Such elastic flaps 33b engage with ribs 32a obtained on the neck 32 of the container 30, having at least one portion extending in a transverse direction with respect to the direction of extension of the side edges 33a of the cap 33.

[0036] The dosing system 20 may further comprise a container-changing assembly 40. The container-changing assembly 40 comprises a support element 41 mounted on the main plate 23 and defining a rotation pin 41a for at least one, and preferably two container-holder elements 42. Each container-holder element 42 comprises a support arm 42a having a radially inner end hinged to the rotation pin 41a, and therefore capable of rotating about a vertical rotation axis Z2 defined by the rotation pin 41a.

[0037] By rotating about the vertical rotation axis Z2, the support arm 42a is able to slide upon the upper surface 23c of the main plate 23. The radially outer end of the support arm 42a has a housing portion 42b, wherein a bay 42c is formed that is open radially outwards, and wherein the profile thereof matches the profile of the outer side surface of the main body 31 of the container 30. At the bottom of the bay 42c, the housing portion 42b has a support protrusion 42d that is configured to provide support for a shoulder of the container 30. A pair of elastic teeth 42e, arranged on opposite sides of the bay 42c, is obtained on the support projection 42d for snap-fitting the neck 32 of the container 30. Correspondingly, on an inner surface of the bay 42c, a pair of protruding formations 42g is formed, configured for snap-fitting the main body 31 of the container 30. A pair of end extensions 42f arranged on opposite ends of the support protrusion 42 is furthermore obtained on the support projection 42d for slidingly coupling with the guide formation 24b of the guide element 24.

[0038] By virtue of the arrangement described above, each container-holder element 42 is capable of completing a circular trajectory between an insertion position, shown in Figures 1, 7 and 8, and a working position wherein the container 30 is arranged aligned with the through hole 22 of the interface 21. An end stop, at the insertion position, is defined by the support element 41. Another end stop, at the working position, is defined by a surface of the support arm 42a of the container-holder element 42 that has remained in the insertion position, whereagainst there abuts a corresponding surface of the support arm 42a of the container-holder element 42 that has been conveyed to the working position. The container-holder element 42 may be manually moved between the insertion position and the working position. According to an alternative embodiment, not shown, the movement of the container-holder element 42 may be driven by a dedicated actuator.

[0039] The dosing system 20 further comprises a sensor 45 that is configured to provide a detection signal for indicating that the working position has been reached on the part of one of the container-holder elements 42.

[0040] The figures also show a control lever 51 and related gears 52, 53 by means whereof it is possible to adjust the mutual distance of the grinders of the grinding device. Such elements are not the object of the invention and will not therefore be described further.

[0041] A container 30 provided with a cap 33 is inserted into one of the container-holder elements 42, according to the direction of the arrow A shown in Figure 1. The cap 33 is then slid along the relevant cap receiving seat 23d obtained within the interface 21, until the main body 31 of the container 30 is coupled to the protruding formations 42g, and the neck 32 of the container 30 is coupled to the elastic teeth 42e.

[0042] At this point, the container-holder element 42 may be rotated until the working position is reached. At the beginning of this movement, the container 30 disengages from the cap 33 which remains within the relative cap receiving seat 23d, by virtue of the fact that the coupling flaps 33d of the cap 33 are arranged parallel to the local direction of movement of the container 30. The container 30 may then slide with the lower opening thereof substantially in contact with a substantially continuous sliding surface, initially defined by the upper surface of the cap 33 and then by the upper surface 23c of the main plate 23, and finally by the top surfaces 27g and 26d of the shutter blades 26, 27 which are in the closed position thereof. Along the entire path the coffee beans are therefore prevented from escaping from the container 30.

[0043] Once the container-holder element 42 has reached the working position, this state is detected by the sensor 45, which provides a signal authorizing a control unit of the system to activate the actuator 29' in order to convey the shutter blades 26, 27 to the opening position, and to thus perform the dosage of the coffee beans.

Claims

CLAIMS1. Device for grinding coffee beans, comprising: a device body ( 11 ) in which a grinding chamber ( 13 ) is formed, the grinding chamber(13) opening aloft towards the outside of the device body (11), through a feed opening (14); a grinder shaft (12c) arranged in the grinding chamber (13) and rotating about a rotation axis (z), the grinder shaft (12c, 12c’) being arranged coaxially with the feed opening(14); a dosing system (20) comprising an interface (21) coupled to the device body (11), wherein the interface (21) is configured to support a container (30) for coffee beans and defines a through hole (22) aligned with the feed opening (24) to form a passage for the coffee beans to fall from the container (30) to the grinding chamber (13); a shutter closing unit (25) having a plurality of shutter blades (26, 27) slidable between an opening position and a closure position for selectively allowing or blocking a flow of coffee beans through said passage; and an actuator (29’) operable so as to move the plurality of shutter blades (26, 27) with respect to the passage; characterized in that the grinder shaft (12c, 12c’) extends axially until up to a plane defined by the shutter blades (26, 27), wherein, in the closing position, respective leading edges (26a, 27a) of the shutter blades (26, 27) cooperate so as to delimit a residual hole (28) receiving an upper end of the grinder shaft (12c, 12c’).

2. Device according to claim 1, wherein respective notches delimiting complementary portions of the residual hole (28) are formed on the leading edges (26a, 27a) of the shutter blades (26, 27).

3. Device according to claims 1 or 2, wherein the residual hole (28) has a beveled edge.

4. Device according to any of the preceding claims, wherein said plurality of shutter blades comprises a pair of shutter blades (26, 27) hinged to the interface (21) at a same rotation axis (zi).

5. Device according to claim 4, wherein the shutter blades (26, 27) are arranged in a blade seat (23e) formed on an upper surface (23c) of the interface (21), said shutter blades having respective peripheral edges (26b, 27b) slidingly coupled to an edge (23g) of the blade seat (23).

6. Device according to claim 5, wherein said pair of shutter blades comprises a first blade (26) comprising a first portion (26c) delimited aloft by a first top surface (26d) and at least one second portion (26e) delimited aloft by a second top surface (26f) recessed with respect to the first top surface (26d), and a second blade (27) capable of sliding on the second top surface (26f) of the first blade (26) and having a top surface (27g) flush with the first top surface (26d) of the first blade (26).

7. Device according to claim 6, wherein the top surface (27g) of the second blade (27) and the first top surface (26d) of the first blade (26) are arranged flush with the upper surface (23c) of the interface (21).

8. Device according to any of the preceding claims, wherein the actuator (29’) is an electrically driven linear actuator and is connected to the plurality of shutter blades (26,27) by means of a transmission (29).

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