WO2019058267A1

WO2019058267A1 - Device for grinding and pressing coffee

Info

Publication number: WO2019058267A1
Application number: PCT/IB2018/057201
Authority: WO
Inventors: Francesco D'ursi; Gianluca BONO
Original assignee: B.M. Laser S.R.L.
Priority date: 2017-09-19
Filing date: 2018-09-19
Publication date: 2019-03-28
Also published as: IT201700104696A1

Abstract

The device (1) for grinding and pressing coffee comprises: one main frame (29) firmly resting on a work surface; and - one closed-chamber work assembly (2, 7, 27, 19, 11) which is adapted to grind and press coffee, mounted on the main frame (29) and comprising: coffee grinding means (2, 7) adapted to grind coffee beans; and coffee pressing means (27, 19) adapted to press the ground coffee inside a filter holding element (16).

Description

DEVICE FOR GRINDING AND PRESSING COFFEE

Technical Field

The present invention relates to a device for grinding and pressing coffee.

Background Art

The quality of espresso coffee in the cup is determined by several factors: the quality of the raw material, grinding, pressing of the powder, water used for extraction, pressure, temperature, chemical characteristics and finally the manual skill of whosoever prepares the beverage.

There is no doubt that the grinding as well as the pressing of the coffee if done incorrectly will negatively affect the result in the cup.

The preparation of an espresso coffee is therefore carried out by correctly grinding a certain quantity of coffee beans, pressing the powder obtained with strength and flatness and extracting the latter with water at known pressure and temperature.

The pressing of the powdered coffee is mainly done using manual pressing devices or pressing devices integrated in the frontal area of the grinder. Other pressing devices are known, but less used, such as telescopic column presses with or without the dynamometric device for regulating the pressing operation. All these known pressing devices, in particular the manual ones, have the following drawbacks which negatively affect the quality of the dispensed espresso coffee: difficulty in applying correct and repeatable pressures, difficulty in performing level pressing, favoring "channeling", i.e., the channeling of water into the thinner and less pressed areas of the coffee panel during the dispensing phase.

In the systems of known type, the withdrawal of the dose of powdered coffee and its pressing take place at different times and in different work groups.

This asynchrony causes longer times for operations and residues on the worktop, since the coffee powder is not perfectly conveyed inside the filter holder.

These latter known problems are more present in instantaneous grinding systems also because of the phenomenon of electrostatic currents which increase the volatility of the coffee powders. Moreover, grinding systems of known type require continuous calibration and maintenance operations because of the same drawbacks mentioned above.

Last but not least, there is the problem of coffee residue coming out of the grinding chamber. At the end of each grinding cycle, a ground coffee powder residue remains which is discharged during the next cycle. If the time between one cycle and another is significant (about 10-15 minutes), the coffee residues will contaminate the subsequent doses of fresh coffee, negatively affecting the quality of the espresso coffee infusion.

Description of the Invention

The main aim of the present invention is to provide a device for grinding and pressing coffee which, continuously and quickly, allows grinding the coffee beans and pressing the ground coffee obtained inside a single closed-chamber work assembly, also avoiding the known drawbacks of contamination of the freshly ground coffee by previous coffee powder residues, wastes and residues on the worktops and on the edges of the filter holder.

Within this aim, one object of the present invention is to provide a device for grinding and pressing coffee which grinds and presses the panel of powdered coffee in the filter holder in a regular manner with the right force and flatness. A further object of the present invention is to obtain a coffee grinding and pressing device which reduces the execution times of espresso coffee.

Another object of the present invention is to provide a device for grinding and pressing powdered coffee which allows precisely preparing the desired dose of coffee without leaving coffee residues inside and outside the work assembly. A further object of the present invention is to provide a device for grinding and pressing powdered coffee which allows overcoming the aforementioned drawbacks of the prior art within the scope of a simple, rational, easy, efficient to use and cost-effective solution.

The aforementioned objects are achieved by the present invention having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more evident from the description of several preferred, but not exclusive embodiments of a device for grinding and pressing powdered coffee, illustrated by way of an indicative, but non-limiting example, in the attached drawings in which:

Figure 1 is a sectional view of the device according to the invention;

Figure 2 is a sectional view of the pressing chamber in which the pressing element is at the beginning of the pressing step according to the invention;

Figure 3 is a sectional view of the pressing chamber in which the pressing element is at the end of the pressing step according to the invention;

Figure 4 is an upper sectional view of the grinding chamber according to the invention;

Figure 5 is a sectional side view of the grinding chamber according to the invention;

Figure 6 is a sectional view of an additional embodiment of the device according to the invention.

Embodiments of the Invention

With particular reference to these illustrations, reference numeral 1 globally indicates a device for grinding and pressing coffee.

The device 1 for grinding and pressing coffee comprises:

at least one main frame 29 firmly resting on a work surface; and

- at least one closed-chamber work assembly 2, 7, 27, 19, 11 which is adapted to grind and press coffee, mounted on the main frame 29 and comprising: coffee grinding means 2, 7 adapted to grind coffee beans; and

coffee pressing means 27, 19 adapted to press ground coffee inside at least one filter holding element 16.

The grinding means 2, 7 comprise at least one grinding chamber 2 and at least one hinged grinding element 7 rotating around an axis of rotation A inside the grinding chamber 2 and adapted to grind coffee beans.

Advantageously, the device 1 for grinding and pressing coffee comprises at least one conveying element 3 adapted to contain the coffee beans 5 and loaded through the loading opening 4. The conveying element 3 allows the coffee beans 5 to pass into the grinding chamber 2.

The device 1 comprises at least a first mechanical actuator 8, 9 of the grinding element 7, the first mechanical actuator 8, 9 making the grinding element 7 rotate around the axis of rotation A at a predetermined angular velocity value for grinding the coffee beans.

In the embodiment shown in the illustrations, the first mechanical actuator 8, 9 comprises a motor 9 and a driving shaft 8 rotating around the axis of rotation A and the grinding chamber 2 comprises two grinding elements 7, in this case two grinders operating in conjunction to each other and kinematically associated with the driving shaft 8. The ground coffee comes out in the form of powder from the slots 10 between the grinders.

Advantageously, according to the present invention, the device 1 comprises movement means for moving the grinding elements 7, the movement means being adapted to adjust the distance of the same close to or away from each other along the axis of rotation A, so as to restrict or enlarge the slots 10 depending on the characteristics of the blend of coffee beans to be ground and depending on the grain size of the coffee powder to be obtained. According to the present invention, the driving shaft 8 can be provided with motion transmission means, of known type and not shown, for rotating the grinders 7 which are not in axis with the axis of rotation A.

Advantageously, the device 1 comprises first control means of the grinding means 2, 7, the first control means modifying the predetermined rotational speed value exerted by the first mechanical actuator 8, 9.

This way, the first control means, not shown and of known type, control the rotation of the motor 9 and consequently the rotation of the grinding elements 7. Conveniently, the variation in rotation speed of the grinding elements 7 permits varying the quantity of ground coffee according to the characteristics of the blend of coffee beans used by the device 1 and according to the precise quantity of powdered coffee to be obtained at each coffee dose preparation cycle.

The work assembly 2, 7, 27, 19, 11 comprises connection means 11 interposed between the grinding means 2, 7 and the pressing means 27, 19, adapted to convey the ground coffee from the grinding means 2, 7 to the pressing means 27, 19 and comprising at least one expansion area 12.

Advantageously, the connection means 11 are composed of a conveyor which is interposed between the grinding chamber 2 and the pressing chamber 27 to form the closed-chamber work assembly 2, 7, 27, 19, 11, as shown in Figure 1. The grinding element 7 comprises at least one dragging profile 28 arranged in contact with the grinding chamber 2, the dragging profile 28 pushing the ground coffee into the connection means 11.

Conveniently, the powdered coffee coming out of the slots 10 is pushed, by means of the inclined dragging profiles 28 of the grinders, according to the tangential trajectory B into the expansion area 12 of the connection means 11. Advantageously, according to the present invention, the tangential trajectory B allows the coffee powder to be immediately introduced into the expansion area

12 without leaving deposits of powder in the grinding chamber 2.

The pressing means 27, 19 comprise at least one pressing chamber 27 and at least one hinged pressing element 19 moveable along a direction of work C inside the pressing chamber 27 and adapted to press the ground coffee inside the filter holding element 16.

Conveniently, the pressing chamber 27 is substantially hollow and preferably cylindrical in shape.

Furthermore, the work assembly 2, 7, 27, 19, 11 comprises a discharge opening

13 obtained at the bottom of the pressing chamber 27 and adapted to discharge the ground coffee into the filter holding element 16.

The ground coffee conveyed into the pressing chamber 27 through the connection means 11 is in fact arranged inside the filter holding element 16 through the discharge opening 13.

This way, the pressing element 19 slides inside the pressing chamber 27 and moves close to the discharge opening 13, until the ground coffee is pressed inside the filter holding element 16.

Advantageously, the pressing element 19 is cylindrical in shape and substantially complementary to the shape of the pressing chamber 27.

The device 1 comprises removable fixing means 15 of the filter holding element 16 to the pressing chamber 27 which fixing means are adapted to associate hermetically the filter holding element 16 to the pressing chamber 27.

Conveniently, the filter holding element 16 is fixed to the pressing chamber 27 by means of the fixing means 15 and by means of an adjustable stop element 17 as shown in Figure 1.

Advantageously, the hermetic coupling between the filter holding element 16 and the pressing chamber 27 prevents coffee powder and residues from escaping onto the worktop and also ensures pressing flatness.

Furthermore, the device 1 comprises detection means 18 for detecting the presence of the filter holding element 16 which make it possible to start the work cycle.

The pressing of the coffee powder takes place in the pressing chamber 27 by means of the pressing element 19.

The device 1 comprises at least a second mechanical actuator 20, 21 of the pressing element 19, the second mechanical actuator 20, 21 moves the pressing element 19 along the direction of work C to exert a predetermined pressure value on the ground coffee inside the filter holding element 16.

Conveniently, the second mechanical actuator 20, 21 is a piston comprising a cylinder 21 and a rod 20 having an end portion arranged facing the filter holding element 16 and with which the pressing element 19 is associated.

This way, the pressing element 19 is pushed towards the filter holding element 16 by means of the rod 20 which completes the stroke required inside the cylinder 21 to press the coffee powder inside the filter holding element 16. Figure 1 shows the cylinder 21 and the rod 20 in idle position, Figure 2 shows the cylinder 21 and the rod 20 at the start of the pressing phase, while Figure 3 shows the cylinder 21 and the rod 20 at the end of the pressing phase.

Advantageously, the second mechanical actuator 20, 21 can be operated mechanically, e.g., by means of a lever connected to the piston, or electronically, e.g., by means of an electronic push-button panel.

The second mechanical actuator 20, 21 rotates the pressing element 19 around the direction of work C.

Advantageously, at the end of the pressing cycle, while the pressing element 19 presses the ground coffee inside the filter holding element 16, the second actuator 20, 21 rotates the pressing element 19 around the direction of work C. This way, the rotation of the pressing element 19 in contact with the powdered coffee panel allows cleaning the surface of the pressing element 19 itself.

The device 1 comprises second control means of the pressing means 27, 19, the second control means modifying the predetermined pressure value exerted by the second mechanical actuator 20, 21.

Advantageously, according to the present invention, the force exerted by the piston can be calibrated by the second control means so as to produce the same force at each work cycle (about 20-25 kg) on the ground coffee panel and thus ensure the constant quality of the coffee infusion.

The pressing element 19 comprises cleaning means 22 for cleaning the pressing chamber 27, the cleaning means 22 are arranged in sliding contact with the pressing chamber 27.

Advantageously, the cleaning means 22 are arranged on the upper and lower ending part of the pressing element 19.

Moreover, according to the present invention, the cleaning means 22 can be made, e.g., as o-rings in plastic and antistatic material to avoid dust accumulation at the end of each work cycle. The internal surface of the pressing chamber 27 is substantially in contact with the cleaning elements 22 to obtain, at each sliding of the pressing element 19, the total conveying of the coffee powder into the filter holding element 16, leaving the walls of the pressing chamber 27 perfectly clean and free of coffee powder residues.

The present invention is completed by the main frame 29 which comprises a casing 26 of the grinding chamber 2 and a casing 24 of the pressing chamber 27, equipped with a closing element 25 and fixed by means of retention elements 23 to the casing 26.

An additional embodiment of the device 1 is shown in Figure 6, wherein, unlike what has been described with reference to the previous embodiment of the device 1, the work assembly 2, 7, 27, 19 is without the connection means 11, and wherein the grinding chamber 2 and the pressing chamber 27 are directly communicating with each other, substantially defining a single chamber for grinding and pressing the coffee.

It has in practice been ascertained how the described invention achieves the intended objects and, in particular, the fact is underlined that the grinding of the coffee beans and the pressing of the ground coffee take place in a continuous manner. Moreover, the grinding of the coffee and the pressing of the ground coffee inside the filter holding element take place within a single work assembly. The accumulation of powder and the phenomenon of electrostatic currents during the grinding phase are avoided by the tangential trajectory B of the ground coffee and by the expansion area which reduces friction and conveys the coffee powder into the pressing chamber. The pressing chamber is hermetically coupled to the filter holding element to prevent the coffee powder coming out into the working area, while in the pressing chamber the cleaning elements, preferably inclined and preferably made of antistatic material, keep the pressing chamber free of residues which accumulate due to the phenomenon of electrostatic currents.

Claims

1) Device (1) for grinding and pressing coffee, characterized by the fact that it comprises:

at least one main frame (29) firmly resting on a work surface; and

- at least one closed-chamber work assembly (2, 7, 27, 19, 11) which is adapted to grind and press coffee, mounted on said main frame (29) and comprising:

coffee grinding means (2, 7) adapted to grind coffee beans; and coffee pressing means (27, 19) adapted to press the ground coffee inside at least one filter holding element (16).

2) Device (1) according to claim 1, characterized by the fact that said grinding means (2, 7) comprise at least one grinding chamber (2) and at least one hinged grinding element (7) rotating around an axis of rotation (A) inside said grinding chamber (2) and adapted to grind coffee beans.

3) Device (1) according to one or more of the preceding claims, characterized by the fact that said pressing means (27, 19) comprise at least one pressing chamber (27) and at least one hinged pressing element (19) moveable along a direction of work (C) inside said pressing chamber (27) and adapted to press the ground coffee inside said filter holding element (16).

4) Device (1) according to one or more of the preceding claims, characterized by the fact that said work assembly (2, 7, 27, 19, 11) comprises connection means (11) interposed between said grinding means (2, 7) and said pressing means (27, 19), adapted to convey the ground coffee from said grinding means (2, 7) to said pressing means (27, 19) and comprising at least one expansion area (12).

5) Device (1) according to one or more of the preceding claims, characterized by the fact that it comprises at least a first mechanical actuator (8, 9) of said grinding element (7), said first mechanical actuator (8, 9) rotating said grinding element (7) around said axis of rotation (A) at a predetermined angular velocity value for grinding coffee beans.

6) Device (1) according to one or more of the preceding claims, characterized by the fact that said grinding element (7) comprises at least one dragging profile (28) arranged in contact with said grinding chamber (2), said dragging profile (28) pushing the ground coffee into said connection means (11).

7) Device (1) according to one or more of the preceding claims, characterized by the fact that said pressing element (19) comprises cleaning means (22) for cleaning said pressing chamber (27), said cleaning means (22) being arranged in sliding contact with said pressing chamber (27).

8) Device (1) according to one or more of the preceding claims, characterized by the fact that it comprises removable fixing means (15) of said filter holding element (16) to said pressing chamber (27) adapted to associate hermetically said filter holding element (16) to said pressing chamber (27).

9) 9) Device (1) according to one or more of the preceding claims, characterized by the fact that it comprises first control means of said grinding means (2, 7), said first control means modifying said predetermined rotational speed value exerted by said first mechanical actuator (8, 9).

10) Device (1) according to one or more of the preceding claims, characterized by the fact that said grinding means (2, 7) comprise at least one pair of grinding elements (7) defining at least one slot (10) between them, and by the fact that it comprises movement means for moving said grinding elements (7) close to or away from each other along the axis of rotation (A), so as to restrict or enlarge said slot (10).

11) Device (1) according to one or more of the preceding claims, characterized by the fact that it comprises at least a second mechanical actuator (20, 21) of said pressing element (19), said second mechanical actuator (20, 21) moving said pressing element (19) along said direction of work (C) to exert a predetermined pressure value on the ground coffee inside said filter holding element (16).

12) Device (1) according to one or more of the preceding claims, characterized by the fact that said second mechanical actuator (20, 21) rotates said pressing element (19) around said direction of work (C).

13) Device (1) according to one or more of the preceding claims, characterized by the fact that it comprises second control means of said pressing means (27, 19), said second control means modifying said predetermined pressure value exerted by said second mechanical actuator (20, 21).