Patent Description:
In particular, as is known, there exist grinder-dosers for espresso preparations. Grinder-dosers for preparations other than espresso are also known such as, for example, grinder-dosers for Turkish coffee or American coffee.

These coffee-based preparations require different grinding granulometries so as to optimize the specific brewing technique used to extract coffee for preparing the corresponding beverage. In particular, the granulometry has an average particle size which progressively increases ranging from the Turkish-style grinding to espresso or American coffee (also referred to as filtered coffee).

There is also the need to offer the user high accuracy in the research of the granulometry of ground coffee around the degree of granulometry typical for the specific coffee-based preparation.

In a coffee grinder that uses toothed grinders as a crushing tool, the different profiles of granulometric distribution of the coffee powder for the different types of preparations are obtained by acting on the relative distance between the grinders crushing the beans to a powder.

The smaller the relative displacement between the grinders, the greater the degree of accuracy with which a determined and optimal granulometric profile of the coffee powder is defined, in order to enhance the organoleptic properties of the beverage extracted with the specific selected infusion/extraction method.

The best system known on the market is therefore a continuous micrometric adjustment system, wherein all the adjustment positions within a specific range are possible and selectable.

An adjustment system which allows this continuous adjustment is, for example, adjustment by means of a nut-screw coupling by which the grinders (or in general the tools used for crushing the beans) move away from, or approach, each other.

In practical embodiments, at least one of the grinders is driven and rotated by an electric motor; the other grinder is usually fixed. The grinders are housed inside a grinding chamber.

The grinders in turn are supported and kept appropriately oriented by relative grinder-holders in order to provide an annular outlet section between the grinders that is constant over the entire perimeter thereof, to have a homogeneous distribution of the powder at each outlet point from the grinders. It is therefore understood that the grinders are coaxial with each other.

The driven grinder is coupled to the transmission axis of the motor by means of the relative grinder-holder, and it is put in rotation by the electric motor. The adjustment of the distance between the grinders is obtained by moving at least one of the grinders, which in turn is coupled to its grinder-holder, placing it in axial movement (i.e. by bringing it closer or further away from the other grinder along an axial direction parallel to the rotation axis of the grinder) and this is commonly done, as mentioned, by a nut-screw coupling.

The adjustment system with the nut-screw coupling may be coaxial to the rotation axis of the grinders. In this case, such adjustment system is integrated within the containment body of the grinder-doser.

An internal adjustment system complicates the internal structure of the grinder-doser in the area where the grinders are housed. In some cases, this may also lead to complications in the operative management of the grinders, in terms of maintenance, for example.

Therefore, grinder-dosers have been proposed wherein the adjustment system is arranged outside the containment body of the grinder-doser. The adjustment system is associated with an external appendage of the grinder-doser and is operatively connected to the movable lower grinder by means of a lever, which transmits the adjustment system movements to the grinder.

The lever is arranged below the body of the grinder-doser so as to contact the axially movable lower grinder more easily. The lever and the grinder are not mechanically connected, but simply contact each other. This allows the lever to be freely oriented with respect to the axis of the grinder during its oscillations. Examples of such technical solution are disclosed in <CIT>, <CIT> and <CIT>.

Such technical solution is constructively very easy to implement. However, it is not entirely satisfactory from an operative point of view. The grinder is in fact guided by the lever only in thrust, that is, when the adjustment system imposes axial movements towards the upper grinder. When the adjustment system requires axial movements away from the upper grinder, the lever does not actively operate on the grinder. The lower grinder is in fact lowered by the action of gravity or the thrust generated by the beans that have penetrated between the grinders.

The inevitable axial sliding friction may slow down the lowering of the grinder, preventing the correct axial positioning of the grinder and thus negatively affecting the precision in adjusting the grinding granulometry.

The need of solving the drawbacks and limitations mentioned with reference to the prior art is therefore felt.

Such a need is met by a coffee grinder-doser according to claim <NUM>.

Further features and advantages of the present invention will appear more clearly from the following description of preferred non-limiting embodiments thereof, wherein:.

Elements or parts of elements in common to the embodiments described below are referred to with the same reference numerals.

With reference to the above figures, reference numeral <NUM> globally denotes a coffee grinder-doser according to the present invention.

It should be noted that the grinder-doser of the present invention may not only be applied to grinding of coffee beans, but also to grinding for any beverage or infusion that may be obtained from beans, preferably roasted and subsequently ground, in order to obtain a powder suitable for infusion. Therefore, reference to a "coffee" grinder-doser is made by way of a non-limiting, non-exhaustive, and merely exemplary option of a possible use of the grinder-doser in accordance with the present invention.

The grinder-doser comprises a body <NUM> which encloses a first grinder <NUM> supported by a relative first grinder-holder <NUM>, and a second grinder <NUM> supported by a relative second grinder-holder <NUM>. The body <NUM> may comprise a main hollow element <NUM> which houses said grinders <NUM>,<NUM>.

Preferably, the body <NUM> is provided, on the upper part, with an opening <NUM> for accessing a grinding chamber <NUM> for coffee beans made inside said body <NUM>. Typically, such access opening <NUM> is coupled to conduits or a hopper (not shown in the appended figures) for feeding the beans. The body <NUM> is furthermore provided, at the grinding chamber <NUM>, with an outlet <NUM> for ground coffee.

The first and second grinders <NUM>,<NUM> are facing one to the other along an axial direction X-X and are housed in the grinding chamber <NUM>.

The grinding chamber typically has a cylindrical shape, symmetrical with respect to said axial direction X-X.

The grinders <NUM>,<NUM> are mechanically fixed to the respective grinder-holder <NUM>,<NUM>. The grinders <NUM>,<NUM> are provided with teeth <NUM> which cooperate with each other for crushing or grinding the beans. The granulometry obtainable by the grinders <NUM>,<NUM> is given by the relative axial distance D between the teeth <NUM> of the respective first and second grinders <NUM>,<NUM>.

Usually at least one of said grinders <NUM>,<NUM> is a driven grinder, i.e. it is mechanically connected to motor means <NUM> for its rotation, so as to initiate the grinding. The other grinder is usually fixed in rotation.

For example, as illustrated in the appended figures, the first grinder <NUM> is fixed in rotation and the second grinder <NUM> rotates due to the action of motor means <NUM> to which it is operatively connected.

As will be further explained below, one of said grinders <NUM> is movable along the axial direction X-X with respect to the other grinder <NUM>. The adjustment of the axial position of the axially movable grinder <NUM> with respect to the other axially fixed grinder <NUM> allows the relative axial distance D between the two grinders, and therefore the grinding granulometry, to be adjusted.

Preferably, said grinders <NUM>,<NUM> are coaxial with each other with respect to a rotation axis R-R of at least one grinder, which is parallel to said axial direction X-X.

In particular, the motor means <NUM> which cause the rotating grinder <NUM> to rotate comprise an electric motor <NUM> provided with a drive shaft <NUM> directly or indirectly connected to such second grinder <NUM> by means of the relative second grinder-holder <NUM>.

Preferably, as shown in <FIG>, the drive shaft <NUM> of the electric motor <NUM> is offset from the rotation axis R-R of the driven grinder <NUM> and is connected thereto, for example, by means of a toothed belt <NUM> which connects a toothed wheel <NUM> (keyed onto the second grinder-holder <NUM> around the rotation axis R-R) to a pinion <NUM> integral with the drive shaft <NUM>.

As illustrated in particular in <FIG>, the second grinder-holder <NUM> which supports the second grinder <NUM> in rotation is provided with a shaft <NUM>, which is constrained in rotation on the body <NUM> by at least two bushings or bearings <NUM>, which guide it in rotation.

Preferably, the axially movable grinder <NUM> is the rotating (driven) grinder. In such case, the two bushings or bearings <NUM> which guide the shaft <NUM> of the second grinder-holder in rotation, also allow its translation in the axial direction.

The offset configuration between the motor axis and the grinder axis R-R is preferable with respect to a coaxial configuration in that:.

As shown in the appended figures, the grinder-doser <NUM> comprises an adjustment device <NUM> of the relative axial distance D between said first and second grinders <NUM>,<NUM>.

The adjustment device <NUM> in turn comprises a control element <NUM> which is supported by said body <NUM> in a position offset from said axial direction X-X. In particular, such control element <NUM> is arranged outside the body <NUM> of the grinder-doser <NUM>.

In particular, as illustrated in the appended figures, the control element <NUM> is supported by said body <NUM> by means of a support appendage <NUM> rigidly fixed to the body <NUM>. In more detail, the support appendage <NUM> defines an engagement seat <NUM> for the control element <NUM>.

The control element <NUM> is kinematically connected to the axially movable grinder <NUM> by means of a lever <NUM> pivoted on said body <NUM> to impose on said axially movable grinder <NUM> controlled movements along said axial direction X-X so as to adjust the relative axial distance D between said first and second grinders <NUM>,<NUM>.

In this way, the adjustment of the relative axial distance D between the grinders <NUM>,<NUM> is obtained by axially moving only one grinder <NUM> and the relative grinder-holder <NUM>.

The adjustment device <NUM> of the relative axial distance D between said first and second grinders <NUM>,<NUM> therefore serves as a device for adjusting the grinding granulometry.

According to the invention, said lever <NUM> is kinematically connected to:.

The rotation axes Y1-Y1 and Y2-Y2 of said first and second hinges <NUM>,<NUM> are parallel to the fulcrum axis Y-Y of said lever <NUM>.

Thanks to the invention, the axial movement of the movable grinder <NUM> is guided in both ways along said axial direction X-X (i.e. both towards and away from the other grinder <NUM>) by the lever <NUM> and therefore by the control element <NUM>. Therefore, contrary to what is contemplated in prior art solutions, the axial movement of the movable grinder <NUM> is always perfectly controlled and guided by the adjustment device <NUM>.

This is all made possible by the fact that the constraint between the lever <NUM> and the movable grinder <NUM> is achieved by means of a hinge (second hinge <NUM>) with an axis parallel to the fulcrum axis. The second hinge <NUM> in fact allows to transmit to the movable grinder <NUM> only the axial motion components of the lever <NUM>, while leaving the lever free to modify its own inclination with respect to the axial direction X-X of the grinder <NUM> by rotating around the fulcrum axis Y-Y.

In this way, the drawbacks of the prior art solutions are fully addressed, preventing the inevitable axial sliding friction from affecting the correct axial positioning of the axially movable grinder, and therefore the precision in adjusting the axial distance between the grinders, and therefore the precision in adjusting the grinding granulometry.

This is all made possible without affecting the operation of the lever and without requiring complex technical measures.

Similarly, the connection between the control element <NUM> and the lever <NUM> by means of a hinge (first hinge <NUM>) with an axis parallel to the fulcrum axis Y-Y allows to transmit to the lever <NUM> only the axial motion components imposed by the control element <NUM>, while leaving the lever free to modify its own inclination with respect to the control element <NUM>. As will be further explained below, this also provides for broad freedom of orientation of the control element <NUM> with respect to the lever <NUM>, allowing the grinder-doser <NUM> to be adapted, upon installation, to specific requirements of overall dimension reduction.

According to a preferred embodiment illustrated in the appended figures, the axially movable grinder is the second grinder <NUM>, i.e. the driven grinder, connected to motor means <NUM> for its rotation around said axial direction X-X. Preferably, the first grinder <NUM> is instead fixed both in rotation and axially.

More in detail, such second grinder <NUM> is kinematically connected to said lever <NUM> by means of the second grinder-holder <NUM>, which in turn is kinematically connected to the second hinge <NUM> by interposition of a joint <NUM> suitable to allow the free rotation of the second grinder-holder <NUM> and the associated second grinder <NUM> around said axial direction (X-X) with respect to said lever <NUM>.

In particular, as shown in <FIG> and <FIG>, said joint <NUM> may comprise a support bearing 74a for the shaft <NUM> of the second grinder-holder <NUM> and a bearing-holder 74b. The latter is connected to the lever by means of said second hinge <NUM>, defined by a pair of coaxial pins <NUM> which connect the bearing-holder 74b to the lever <NUM> along the hinge axis Y1-Y1.

Advantageously, as illustrated in particular in <FIG> and <FIG>, the lever <NUM> is constituted by two parallel shaped rods <NUM>,<NUM>, connected to each other by a pin <NUM> which defines the fulcrum <NUM> of the lever on the body <NUM>, and two distinct pairs of coaxial pins <NUM> and <NUM> which respectively form the first hinge <NUM> and the second hinge <NUM>.

According to a particularly preferred embodiment, the first (fixed) grinder <NUM> is an upper grinder, while the second (axially movable and rotating) grinder <NUM> is a lower grinder. Reference is made to a lower and an upper position in relation to said axial direction X-X which in use is preferably vertically oriented.

The preferred choice of adjusting the axial distance D between the two grinders by operating on the lower grinder <NUM> instead of on the upper grinder <NUM> allows the grinders to be replaced and cleaned by disassembling the first grinder-holder <NUM>, without losing the degree of adjustment defined by the axial position of the second grinder-holder <NUM>. In fact, access to the grinding chamber <NUM> is obtained by disassembling and thus removing the first (fixed) grinder-holder <NUM> from the body <NUM>.

In accordance with the embodiments illustrated in the appended figures, said lever <NUM> in use is arranged below the body <NUM>, preferably in an axially opposite position with respect to said opening <NUM> for accessing the grinding chamber <NUM>.

Preferably, as illustrated in <FIG>, said lever <NUM> is connected to opposite ends 70a,70b with respect to its fulcrum <NUM>, respectively to the axially movable grinder <NUM> and the control element <NUM>. In other words, the fulcrum <NUM> is located in an intermediate position between the connection with the control element <NUM> and the connection with the axially movable grinder <NUM>. Operatively, a movement with an axial component transmitted by the control element <NUM> to the lever <NUM> in a first axial direction results in an axial motion of opposite direction on the axially movable grinder <NUM>.

In accordance with an alternative embodiment, illustrated in <FIG>, the fulcrum <NUM> of said lever <NUM> may be arranged at one end of the lever 70a itself, while the control element <NUM> and the axially movable grinder <NUM> are connected to the lever <NUM> on the same side with respect to the fulcrum. In this case, a movement with an axial component transmitted by the control element <NUM> to the lever <NUM> in a first axial direction results in an axial motion in the same direction on the axially movable grinder <NUM>.

The choice between the configuration of the lever with intermediate fulcrum or the configuration of the lever-end fulcrum, as well as the choice of the relative position of the connection with the control element and movable grinder is related to the need to reduce the dimensions of the grinder-doser <NUM> upon installation. Advantageously, in order to facilitate the adaptation of the grinder-doser <NUM> upon installation, the grinder-doser <NUM> may be modularly provided with different attachment points for both the lever fulcrum and the support appendage of the control element as illustrated in <FIG>.

In accordance with a preferred embodiment illustrated in the appended figures, the adjustment device <NUM> comprises a nut-screw system for controlling the amplitude of the axial movements imposed by said control element <NUM> on the axially movable grinder <NUM> by means of said lever <NUM>.

In particular, as illustrated in <FIG>, the control element <NUM> comprises a screw or ring nut <NUM> that is guided by the body <NUM> (which is axially fixed) and is engaged with a first nut-screw <NUM> associated to said lever <NUM> by means of the first hinge <NUM>. Preferably, the screw or ring nut <NUM> is guided by the body <NUM> by means of a second nut-screw <NUM> integral with the body <NUM>. In particular, the second nut-screw <NUM> may be integral with said support appendage <NUM>.

Advantageously, the nut-screw system is well suited for manual operation of the control element <NUM>. Alternatively, if the actuation of the control element <NUM> is automated, the nut-screw system may be replaced by other systems, such as for example a pneumatic cylinder or a rack and pinion system.

Advantageously, the Z-Z axis of said screw or ring nut <NUM> may be parallel to said axial direction X-X (as illustrated in <FIG>) or it may form an angle of inclination α with respect thereto (as schematically illustrated in <FIG>).

Depending on the requirements, the axis Z-Z of the screw <NUM> of the control element <NUM> may have any inclination. The inclination with respect to the axial direction X-X is selected depending on the accessibility spaces available at the assembly site of the grinder-doser <NUM>, which is normally part of a more complex machine. Advantageously, in order to adjust the inclination it is sufficient to replace the adjustment appendage <NUM> with a suitable engagement seat <NUM>.

As illustrated in the appended figures, the screw or ring nut <NUM> may be provided with a knob <NUM> for its manual rotation by a user.

Alternatively or in combination, the screw or ring nut <NUM> may be operatively connected to a motor means for automatic adjustment of the axial distance D between the grinders <NUM>,<NUM>. The motor means <NUM> is schematically represented in <FIG> with a dotted rectangle. It should be noted that the automatic adjustment is not necessarily an alternative to a manual adjustment by the knob <NUM>. In other words, the knob <NUM> and the automatic adjustment by motor may coexist in the same embodiment.

In particular, the automated actuation of the screw or ring nut <NUM> may be obtained by means of a stepper motor, connected to a control unit (not shown in the appended figures) which also controls the electric motor <NUM> actuating the driven grinder <NUM> in rotation. This system would allow, for example, to set up the grinding based on predetermined "recipes". Operatively, by means of the screw <NUM> of the control element the granulometry of ground coffee is adjusted using a stepper motor, while by means of an actuation time of the motor <NUM> the dispensed dose of ground coffee is adjusted.

Claim 1:
A grinder-doser (<NUM>) for beans, for example coffee beans, comprising a body (<NUM>) which encloses a first grinder (<NUM>) supported by a relative first grinder-holder (<NUM>), and a second grinder (<NUM>) supported by a relative second grinder-holder (<NUM>), wherein the first and second grinders (<NUM>,<NUM>) are facing one to the other along an axial direction (X-X) and are housed in a grinding chamber (<NUM>) for coffee beans made inside said body (<NUM>), one of said grinders (<NUM>) being movable along the axial direction (X-X) with respect to the other grinder (<NUM>), said grinder-doser (<NUM>) comprising an adjustment device (<NUM>) of the relative axial distance (D) between said first and second grinders (<NUM>,<NUM>), which in turn comprises a control element (<NUM>) which is supported by said body (<NUM>) in a position offset from said axial direction (X-X) and is kinematically connected to the axially movable grinder (<NUM>) by means of a lever (<NUM>) pivoted on said body (<NUM>) to impose on said axially movable grinder (<NUM>) controlled movements along said axial direction (X-X) so as to adjust the relative axial distance (D) between said first and second grinders (<NUM>,<NUM>), wherein said lever(<NUM>) is kinematically connected to said control element by means of a first hinge (<NUM>), characterized in that said lever (<NUM>) is kinematically connected to said axially movable grinder (<NUM>) by means of a second hinge (<NUM>), the rotation axes (Y1-Y1; Y2-Y2) of said first and second hinges (<NUM>,<NUM>) being parallel to the fulcrum axis (Y-Y) of said lever (<NUM>).