Coffee grinding machine with a system for simplifying opening and closing of the grinding chamber

Abstract

A coffee grinding machine is described that includes a grinding chamber, the grinding chamber including a lower portion and an upper portion, the upper and lower portions of the grinding chamber being separable from one another, the grinding chamber configured to have a closed operating position in which the upper portion is connected to the lower portion and an open position in which the upper portion is separated from the lower portion, the lower portion of the grinding chamber including a first bar and the upper portion including a second bar configured to cooperate with the first bar to grind coffee beans, the upper portion also including an adjustment mechanism configured to adjust the relative distance between the first bar and the second bar in the closed operating position to vary the fineness of the ground coffee, and in the open position the second bar is connected to the upper portion of the grinding chamber and separated from the first bar, and in the closed operating position the upper and lower portions are joined by magnetic attraction.

Description

[Technical Field]

[0001] The present invention relates to a machine for grinding coffee beans, which can be a separate machine or can be integrated into a machine for producing coffee-based beverages, and which is also known simply as a "coffee grinding machine", "coffee grinder" or "mill".

[0002] More particularly, the present invention relates to the opening and closing of a grinding chamber. Even more particularly, the present invention relates to a mechanism that can simplify the opening (and closing) of a grinding chamber. [Background technology]

[0003] As is known, a certain amount of ground coffee, commonly referred to as a "dose," is used to prepare espresso coffee. The dose can be a single dose, a double dose, or multiple doses. The dose of ground coffee is typically loaded into a filter in the form of a cup with an open top and a micro-perforated bottom. The dose of coffee is typically compressed within the filter to form a coffee powder pack. The filter is then supported by a filter holder configured to removably engage within the dispensing unit of an espresso coffee machine. Hot water is passed under pressure through the coffee powder pack to obtain espresso coffee.

[0004] Coffee powder is obtained in a coffee grinding machine. In known coffee grinding machines, coffee beans are ground by passing them through grinding elements. Flat, conical or mixed grinding elements are known. Typically, the grinding elements of a coffee grinding machine comprise a fixed element and an element that rotates relative to the fixed element. For example, in a coffee grinding machine with flat burrs, one burr remains stationary while the other burr is rotated by a motor. Some coffee grinding machines allow the distance between the burrs to be modified in order to vary the particle size of the coffee powder.

[0005] Patent document 1 describes a coffee grinding machine having a housing and two grinding discs arranged opposite each other, the engagement of the grinding discs with the flange of the fixed disc or the flange of the rotor being effected by magnets connected to the flange of the fixed disc or the flange of the rotor.

[0006] US Pat. No. 5,649,999 describes a grinder for crushing tobacco leaves. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] German Utility Model No. 2020 / 07016141 [Patent Document 2] US Patent Application Publication No. 2012 / 0168544 Summary of the Invention [Problem to be solved by the invention]

[0008] The applicant has carefully investigated known coffee grinding machines.

[0009] As is well known, in known coffee grinding machines for home and commercial use, it is desirable to be able to vary the distance between the burrs accurately, repeatably and stably, which allows for the adjustment of the particle size of the coffee powder thus produced, which can have a series of advantages.

[0010] For example, a variety of particle sizes can be obtained, from very fine to coarser particle sizes, suitable for different types of extraction operations.

[0011] It is desirable that the user feel comfortable and comfortable with the movements when adjusting the particle size.

[0012] It is also desirable that the operation for adjusting the particle size is simple and the set value is relatively easy to read.

[0013] To at least partially obtain the aforementioned properties, the burrs and all parts forming the grinding chamber must be rigid and extremely stable, while at the same time, particularly in the case of "on-demand" coffee grinding machines, i.e. machines that grind doses from a pre-loaded amount of coffee beans, the grinding chamber must be easy to open and at least some of the parts must be separable from one another.

[0014] Opening the grinding chamber is necessary to check the wear state of the burrs, but especially to remove coffee residues.

[0015] It is common to clean the grinding chamber by removing coffee residue. While cleaning of the grinding chamber and burrs should be done regularly, it is clearly recommended to clean the grinding chamber even for a short period of time before discontinuing use of the coffee grinding machine. In fact, coffee residues are prone to oxidation and emit a foul odor. Failure to remove coffee residues can result in mold growing on the coffee residues. This mold has a negative impact on the quality of the ground coffee, especially the first grind dose.

[0016] When grinding preselected doses, especially high-quality doses, removing coffee residues is necessary to ensure that the entire amount of coffee beans fed into the machine is collected in ground form. This can be easily achieved by using a small brush after opening the grinding chamber.

[0017] More generally, when the type of coffee being ground is changed, it is highly recommended to remove the coffee residue.

[0018] Coffee grinding machines are known that have a system for opening the grinding chamber. To ensure rigidity, in many applications, the grinding chamber can be opened by removing one of the bars using a tool such as a screwdriver or an Allen wrench. The use of a tool discourages users from regularly opening the grinding chamber for cleaning and maintenance.

[0019] The Applicant therefore set out to find a reliable and advantageous solution for the safe and easy opening of the grinding chamber and for the stable and reliable closing of the grinding chamber.

[0020] According to the Applicant, the above and other objects are achieved with a coffee grinding machine comprising a grinding chamber, the closure of which is ensured by magnetic force, while the opening of the grinding chamber is performed by the user by applying a force opposite to the closing magnetic force. Advantageously, according to embodiments, no tools are required to open the grinding chamber.

[0021] The simplification of opening the grinding chamber according to the invention is of great advantage to the user, especially since no tools are required: in this way, cleaning cycles can be carried out more frequently and without the need for the assistance of a technician (especially in a domestic environment).

[0022] The invention is particularly applicable to any coffee grinding machine having a flat burr, a conical burr, or a mixing burr.

[0023] The applicant has noticed that the solution described in patent application WO 2007 / 023990 does not solve the problem of facilitating the opening of the grinding chamber: in fact, the upper and lower parts of the grinding chamber are joined by screws.

[0024] Furthermore, the applicant has noticed that in the solution described in Patent Document 1, the fineness setting is lost by unscrewing the upper part from the lower part every time the grinding chamber is opened. Therefore, when the upper part is re-screwed onto the lower part of the grinding chamber, the fineness adjustment must be performed again. This operation is inconvenient and discourages users from performing it frequently. Instead, opening the grinding chamber must be performed daily, or in any case frequently, in order to clean the coffee powder bars and thereby prevent the coffee remaining between the bars from emitting a bad odor. [Means for solving the problem]

[0025] According to a first aspect, the present invention provides a coffee grinding machine for grinding coffee beans, comprising a grinding chamber, the grinding chamber including a lower portion and an upper portion, the upper and lower portions of the grinding chamber being separable from each other, the grinding chamber being configured to assume a closed operating position in which the upper portion is joined to the lower portion and an open position in which the upper portion is separated from the lower portion, the lower portion of the grinding chamber comprising a first bar, the upper portion comprising a second bar configured to cooperate with the first bar to grind the coffee beans, the upper portion also comprising an adjustment mechanism configured to adjust the relative distance between the first bar and the second bar in the closed operating position to vary the fineness of the ground coffee, the second bar being connected to the upper portion of the grinding chamber and separated from the first bar in the open position, the upper and lower portions being joined together by magnetic attraction in the closed operating position. Essentially, the second bar is integral with the upper portion of the grinding chamber, and when the upper portion is separated from the lower portion, the two bars are separated. In this way, residual coffee can be easily cleaned separately from the bars, for example, using compressed air and / or a brush. Advantageously, the adjustment mechanism forms part of the upper part of the grinding chamber, and the adjustment is maintained even when the grinding chamber is open and the bars are separated from each other, and the adjustment mechanism is independent of the magnetic arrangement for closing the grinding chamber.

[0026] According to the present invention, the upper and lower parts are not joined by screws or bolts.

[0027] According to an embodiment, the lower part of the grinding chamber comprises a single magnet or multiple magnets.

[0028] According to an embodiment, the magnet or magnets are arranged within the thickness of the lower part of the grinding chamber.

[0029] According to an embodiment, the upper part of the grinding chamber comprises a single magnet or multiple magnets.

[0030] According to an embodiment, the magnets are pin-shaped and are preferably angularly equally spaced.

[0031] According to an embodiment, the part of the grinding chamber opposite the part containing the magnets contains a body made of ferromagnetic material.

[0032] According to an embodiment, the first bar is mechanically connected to the lower part of the grinding chamber by means of a screw or other threaded member.

[0033] According to an embodiment, the second bar is mechanically connected to the top of the grinding chamber by a screw or other threaded member.

[0034] According to an embodiment, the second bar is integrated with a threaded bar holder disk and the adjustment device comprises a ring nut.

[0035] According to an embodiment, the ring nut includes an inner ring nut having an adjustment thread formed therein and an outer ring nut that serves as a grip for the operator.

[0036] According to an embodiment, a sliding track is arranged between the lower and upper parts.

[0037] According to an embodiment, a positioning member is provided for connecting the lower and upper portions together in position.

[0038] According to an embodiment, the positioning member includes teeth protruding radially inward from the inner circumference of the sliding track and corresponding notches on the bar holder disc, or includes notches on the lower part of the grinding chamber and teeth on the bar holder disc.

[0039] According to embodiments, the teeth are not angularly equally spaced and / or have different shapes and / or have different sizes.

[0040] There now follows a detailed description of the invention, given purely by way of non-limiting example and to be read with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0041] [Figure 1.1]1 is a schematic diagram of a coffee grinding machine according to an embodiment of the present invention; [Figure 1.2] A longitudinal section of the machine shown in Figure 1.1. [Figure 2] FIG. 2 is an enlarged vertical cross-sectional view of a grinding chamber according to an embodiment of the present invention. [Figure 3] FIG. 3 is an enlarged longitudinal cross-sectional view of the grinding chamber of FIG. 2 without the ring nut assembly connected thereto. [Figure 4] FIG. 4 is an exploded vertical cross-sectional view of a fixing screw and a sliding plate. [Figure 5] FIG. 10 is an axonometric view from above of the fixing screw and sliding plate in a disassembled state. [Figure 6] FIG. 10 is an axonometric view from below of the fixing screw and sliding plate in a disassembled state. [Figure 7] FIG. 2 shows a second embodiment of the grinding chamber, in which the closing of the grinding chamber is performed by magnetic attraction. [Figure 8] FIG. 1 is an exploded axonometric view of the lower part of the grinding chamber. DETAILED DESCRIPTION OF THE INVENTION

[0042] Figures 1.1 and 1.2 show a coffee grinding machine according to an example of embodiment of the invention. Obviously, the coffee grinding machine according to the invention can take a form entirely different from that shown without departing from the scope of protection of the invention.

[0043] The machine 10 comprises a machine body 12 containing the main components, including a grinding chamber 30 having a burr assembly 36. Typically, the machine 10 comprises a hopper 14 at its top, which is configured to contain the coffee beans to be ground and to allow the coffee beans to reach the grinding chamber 30 and the burr assembly 36.

[0044] The machine 10 also includes a device for adjusting the fineness of the powder to be ground, which will be explained in more detail below.

[0045] The machine 10 also comprises an outlet duct 16 for directing the ground coffee to a filter 18, which is supported by a filter holder 20. Advantageously, a support 22 may be provided for supporting the filter holder 20 while the ground coffee powder is being filled into the filter 18. The support 22 is height adjustable. Also shown in Figure 1.1 are a push button 26 for operating the coffee grinding machine and an LED (or display) for indicating the status of the machine 10.

[0046] Figure 1.2 shows a longitudinal section of the machine shown in Figure 1.1. In addition to the parts already mentioned, the bar assembly and the electric motor 24 for rotating one bar relative to the other are shown.

[0047] The burr assembly (and grinding chamber 30 according to the first embodiment) is shown in more detail in various Figures 2-6.

[0048] Various Figures 2-6 show the grinding chamber 30 with a bar assembly including a lower bar 361 and an upper bar 362. The grinding chamber 30 includes a lower portion 31 and an upper portion 32. The lower portion 31 of the grinding chamber houses the lower bar 361. The upper portion 32 of the grinding chamber includes the upper bar 362.

[0049] According to the embodiment shown, the lower bar 361 is a movable bar. The lower bar 361 is kinematically connected to the motor shaft in any known manner. This connection can be made, for example, by a flanged bar holder disk 361 that rotatably supports the lower bar 361.

[0050] Advantageously, the flanged disc may be provided with a suitable radial profile designed to expel the ground coffee exiting the bars 361 , 362 from the grinding chamber 30 .

[0051] In this specification and the associated drawings, it is clear that the orientation of the axes A of the bars 361, 362 is vertical. However, the invention is also applicable to coffee grinding machines in which the axes of the bars are horizontal or inclined in a direction different from the vertical. In fact, as shown in Figure 1.2, the axes A of the bars are inclined relative to the vertical. The bars can also be arranged in a different way, such as with a movable bar at the top or with two movable bars. Finally, as mentioned above, the invention is also applicable to the case of conical bars.

[0052] The upper bar 362 is aligned on the same axis A. The upper bar 362 is integral with the bar holder disc 4. The bar holder disc 4 is preferably rigidly connected to the upper bar 362, for example by means of screws 41 (FIG. 7). The bar holder disc 4 has a cylindrical outer surface and screws 42 on at least a part of the outer surface.

[0053] The inner adjusting ring nut 17 is arranged radially outside the bar holder disc 4. The inner adjusting ring nut 17 has threads 172 that mate with the threads 42 of the bar holder disc 4.

[0054] The outer adjusting ring nut 15 is arranged radially outside the inner ring nut 17. The outer ring nut 15 is at least partially made of a thermoplastic material and serves as a grip for the operator.

[0055] As will become more apparent below, the bar holder disc 4 (and the upper bar 362 connected thereto) is configured such that it cannot rotate relative to the lower part of the grinding chamber when the grinding chamber is closed. Rotation of the ring nut therefore causes displacement of the bar holder disc 4 and the upper bar 362. Axial displacement can occur in a first direction towards the lower bar or in a second direction away from the lower bar.

[0056] When the grinding chamber is opened, the preset adjustment is not lost and remains the same when the grinding chamber is closed again. This is due to the fact that the grinding adjustment mechanism is independent of the way the upper grinding chamber and the lower grinding chamber are connected.

[0057] The operator can rotate the outer ring nut 15 to increase / decrease the fineness of the ground coffee. The outer and inner ring nuts can be connected to each other by a toothed notch profile and can be uncoupled by a certain amount of axial sliding.

[0058] According to an embodiment of the present invention, the inner ring nut 17 is at least partly made of a ferromagnetic material.

[0059] According to an embodiment of the present invention, the inner ring nut 17 is made substantially entirely of ferromagnetic material.

[0060] The ferromagnetic material may be selected from the group consisting of, for example, iron, steel, nickel, cobalt, chromium, or any combination thereof. A spring 23 is provided. The spring 23 pushes the upper bar upward in the same direction as the pressure acting on the coffee during grinding. This is to eliminate play in the adjustment screw. The spring 23 is attached to an upper seat 25 formed in an upper cap 27.

[0061] According to a first embodiment, at least one magnet 311 is provided which is substantially integral with the lower part 31 of the grinding chamber. According to an embodiment, a plurality of magnets 311 are provided.

[0062] The magnets 311 can be, for example, in the form of pins inserted into the wall of the lower part 31 of the grinding chamber 30. This solution is shown in Figures 2 to 6. The magnetic pins 311 can be arranged in any number, for example 2, 3, 4, 5 or 6 (as in the particular example shown in the drawings). Each pin 311 is inserted into a hole 312 formed in the thickness of the wall of the lower part 31 of the grinding chamber 30.

[0063] According to an embodiment, the holes 312 are equally angularly spaced, but may be spaced differently.

[0064] According to an embodiment, the sliding track 38 may be arranged on the upper surface of the lower part 31 of the grinding chamber 30. The sliding track 38 may, for example, be formed directly in the grinding chamber or may be made of different materials that are preferably non-magnetic and have specific friction properties, such as bronze, brass, polymers, steel, and sintered materials that may be provided with wear-resistant and friction-resistant coatings.

[0065] The sliding track 38 is, for example, in the form of a circular rim and has a small thickness, which may be, for example, a few millimeters, for example, 2 to 6 mm. In other embodiments, the sliding track may not be present, since a sliding track formed directly in the grinding chamber would also ensure functionality.

[0066] The sliding track 38 can be fixed to the top of the lower part of the grinding chamber by means of screws 381 inserted into respective through holes 382 in the sliding track 38 and into respective blind holes 383 in the wall of the lower part 31 of the grinding chamber 30 .

[0067] Advantageously, the heads of the magnetic pins 311 are substantially flush with the upper surface of the sliding track 38 as they each pass through a through hole 313 .

[0068] The purpose of the sliding track 38 is to facilitate the rotational sliding of the inner ring nut 17. This sliding action may be necessary to ensure the fluidity and precision of the bar positioning. A sliding action is also necessary to determine the axial position of the bar holder disc 4 and, as a result, to perform grinding adjustment (the relative distance between the two bars).

[0069] The predetermined position can be defined by a locating member present in the sliding track 38 and / or in the ring nut body 17 directly facing the sliding track 38. The predetermined position must be provided between the sliding track 38 and the upper bar holder disc 4 by, for example, teeth and notches as described below.

[0070] Due to said radial connection, the bar holder disc 4 does not rotate but can slide axially by rotating the outer ring nut 15 via the threading 42-172.

[0071] The teeth may also form part of the grinding chamber 30 .

[0072] By way of example, the various figures show one embodiment of a positioning member that includes teeth 385 projecting radially inward from the inner circumference of the sliding raceway 38 and notches 171 that correspond to the inner ring nut 17. One of the notches 171 is shown in Figure 6. Obviously, the same function may be performed by other positioning members, and in either case the notches may be located in the sliding raceway (or in either case the lower part of the grinding chamber) and the teeth may be located in the inner ring 17.

[0073] In this embodiment, the number of teeth 385 and notches 171 is three, but a fewer (even one) or greater number may be configured. To establish a unique relative position between the inner ring nut 17 and the sliding track 38 (integral with the lower portion 31 of the grinding chamber 30), the teeth 385 and notches 171 are not equally spaced angularly. Thus, there is essentially a unique position for coupling the ring nut body 17 to the grinding chamber. To find this unique coupling position, one or the other must be rotated clockwise or counterclockwise relative to the other.

[0074] Alternatively, the notches 171 (and similarly the teeth 385) may not be the same shape and / or the same size.

[0075] Once the correct stable coupling position is found, the inner ring nut 17 is locked against the lower part 31 of the grinding chamber 30 by the magnetic attraction between the magnet 311 and the ring nut body 17 made of ferromagnetic material.

[0076] The number and diameter of the magnets 311 are dimensioned to provide sufficient attractive force to ensure a stable and reliable bond.

[0077] To open the grinding chamber, the user simply lifts the upper part, i.e., the inner ring nut 17 (along with the outer ring nut 15, upper bar 362, and bar holder disk 4) against the magnetic attraction between the magnet 311 and the inner ring nut 17, which is made of a ferromagnetic material. To open the chamber, the user does not need to use any tools (e.g., a screwdriver, wrench, or hex wrench). Because the upper bar is integrated with the upper part of the grinding chamber, when the upper part of the grinding chamber is lifted, the bars separate from each other, while the lower bar remains in the lower chamber, essentially integrating with the upper part of the grinding chamber. In this way, the two bars can be cleaned and inspected separately.

[0078] Advantageously, the upper chamber maintains the fineness of grind adjustment, in other words, when the upper part of the grinding chamber is reconnected to the lower part, the relative distance between the bars remains the same as it was before the grinding chamber was opened, which is a major advantage as it does not discourage opening the grinding chamber (typically for cleaning purposes).

[0079] Obviously, although it is described herein that the magnet is fixed at the bottom of the grinding chamber and the body made of ferromagnetic material is at the top (inner ring nut), the opposite situation is also possible, i.e. the magnet is at the top and the ferromagnetic material is at the bottom, or a combination of the two solutions.

[0080] Advantageously, an air gap can be provided between the magnet and the ferromagnetic material, which is indicated by t in FIG.

[0081] The invention ensures perfect relative alignment of the two bars during the actuation phase.

[0082] Furthermore, optimum stability is provided in the set adjustment position of the ring nut, ensuring stability during grinding.

[0083] Furthermore, by properly adjusting the attractive forces and coefficients of friction acting on the sliding raceway, optimal sliding and fluid movement of the ring nut is ensured.

[0084] 7 and 8 show another embodiment of the present invention. 31A shows a bell member for supporting the motor assembly that is not made of a metallic material. The bell member may be made of, for example, a thermoplastic material. The bell member substantially covers the lower part of the grinding chamber. A sheet of magnets 311 is formed thereon.

[0085] 31B denotes the lower part of the grinding chamber. Considering that 31B is surrounded by a wall integral with bell member 31A, the wall of the lower part of the grinding chamber may be relatively thin, for example, a few millimeters thick, e.g., 2 mm, made of metal (e.g., stainless steel).

[0086] 31C shows the base of the grinding chamber made of stainless steel. This second embodiment also shows that the magnets can be integrated into the outer wall of the actual grinding chamber, rather than being located within the thickness of the lower part of the grinding chamber.

[0087] For purposes of the present invention, the "lower wall of the grinding chamber" can be a single wall (e.g., made of a metallic material such as stainless steel) or a multi-layer wall (e.g., having an inner layer and an outer layer). A multi-layer wall can include layers made of different materials.

[0088] It is clear that the present invention represents a significant improvement over the solution described in patent application WO 2007 / 024990. In particular, the adjustment device is integrated into the upper part of the grinding chamber and is configured to maintain the grinding setting even when the upper part of the grinding chamber is separated from the lower part.

[0089] Furthermore, according to the present invention, the bar can be made of any material, such as, for example, stainless steel, ceramic material, etc.

Claims

1. A coffee grinding machine (10) for grinding coffee beans, comprising a grinding chamber (30), wherein the grinding chamber (30) comprises a lower part (31) and an upper part (32), and the upper part (32) and the lower part (31) of the grinding chamber (30) are separable from each other. The grinding chamber (30) is configured to take on a closed operating position in which the upper part is joined to the lower part, and an open position in which the upper part is separated from the lower part. The lower part (31) of the grinding chamber is equipped with a first bar (361), The upper part (32) comprises a second bar (362) configured to cooperate with the first bar (361) to grind coffee beans. The upper part (32) further includes an adjustment mechanism (15, 17, 4) configured to adjust the relative distance between the first bar (361) and the second bar (362) in order to change the fineness of the ground coffee in the closed operating position. In the open position, the second bar (362) is connected to the upper part (32) of the crushing chamber and separated from the first bar (361). In the closed operating position, the upper part (32) and the lower part (31) are joined together by magnetic attraction, in the coffee grinding machine (10).

2. The coffee grinding machine (10) according to claim 1, wherein the lower part (31) of the grinding chamber (30) is equipped with a single magnet or a plurality of magnets (311).

3. The coffee grinding machine (10) according to claim 2, wherein the single magnet or the plurality of magnets (311) are arranged within the thickness of the lower part (31) of the grinding chamber (30).

4. The coffee grinding machine (10) according to claim 1, wherein the upper part (32) of the grinding chamber (30) is equipped with a single magnet or a plurality of magnets (311).

5. The coffee grinding machine (10) according to claim 2, 3, or 4, wherein the magnets (311) are pin-shaped and preferably arranged at equal angular intervals.

6. The coffee grinding machine (10) according to claim 1, wherein the portion (32, 31) of the grinding chamber opposite to the portion equipped with the magnet (311) is a body made of a ferromagnetic material.

7. The coffee grinding machine (10) according to claim 1, wherein the first bar (361) is mechanically connected to the lower part (31) of the grinding chamber by a screw or other screw member.

8. The coffee grinding machine (10) according to claim 1, wherein the second bar (362) is mechanically connected to the upper part (32) of the grinding chamber by a screw or other screw member.

9. The coffee grinding machine according to claim 1, wherein the second bar (362) is integrated with a threaded bar holder disc (4), and the adjustment device includes ring nuts (15, 17).

10. The coffee grinding machine according to claim 9, wherein the ring nut comprises an inner ring nut (17) having an adjustment screw (172) formed thereon, and an outer ring nut (15) that functions as a grip for the operator.

11. The coffee grinding machine (10) according to claim 1, wherein a sliding track (38) is disposed between the lower part (31) and the upper part (32).

12. The coffee grinding machine (10) according to claim 11, further comprising positioning members (385, 171) for connecting the lower part (31) and the upper part (32) at predetermined positions.

13. The coffee grinding machine (10) according to claim 12, wherein the positioning member (385, 171) includes teeth (385) projecting radially inward from the inner circumference of the sliding track (38) and a notch (171) corresponding to the bar holder disc (4), or includes the lower notch (171) of the grinding chamber and the teeth (385) of the bar holder disc (4).

14. The coffee grinding machine (10) according to claim 13, wherein the teeth (385) are not arranged at equal angular intervals and / or have different shapes and / or have different sizes.

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