TECHNICAL FIELD

The present invention relates to a capsules closure device for a coffee capsule machine.

BACKGROUND ART

In general, a coffee machine operating with coffee capsules (is also adapted for the preparation of other hot beverages by using capsules containing appropriate ingredients) mainly comprises: a machine body, wherein an infusion chamber is formed, housing in use a capsule; a closure device acting on the capsule for closing the capsule between a holding element (having a seat for the capsule) and an abutment element (piercing head) to define the infusion chamber and pierce the capsule; and hot water circulation means to circulate a pressurized hot water flow through the capsule into the infusion chamber and obtaining an infusion. According to the contents of the capsule, the desired hot drink (coffee, tea, etc.) is obtained.

The closure device must not only push the capsule into position in the infusion chamber, but also close with sufficient force the opposing elements that define the infusion chamber, ensuring the hydraulic seal against the working pressure.

The most common machines are provided with closure devices that are mechanical, hydraulic, or mechanically servo- actuated.

The mechanical systems have the advantage of relatively low production costs and good reliability; however, these systems, in order to be operated with little effort by the user, need complex levers. This complexity affects the chain of tolerances, requiring reset systems during production that do not take into account the abnormal conditions of use (intensive or semi-professional use) . The chain of tolerances of individual parts can then generate malfunctions within the entire system, and reset registers are necessary during the assembly setup.

Hydraulic systems are advantageous from the standpoint of ease of use by the user, but do not allow large excursions of closure, thereby limiting access to the area of insertion of the capsule. In addition, for reasons of cost and rationality of the circuit, if they are used to move the piercing head these systems mainly use the heated water from the boiler and destined for the supply, with consequent problems typical of calcium deposits; systems that instead move the holding element (having the seat for the capsule) utilize cold water, but operate with longer strokes and with very long waiting times .

The servo-actuated systems (usually electric) combine the versatility of the drive motor control with the precision of male-thread/nut-screw actuation. They are capable of sustaining fairly high stress, needing however major space and are therefore bulky, expensive and noisy as well. DISCLOSURE OF INVENTION

It is an aim of the present invention to provide a closure capsule device for a coffee capsule machine that is free of the drawbacks of the prior art highlighted here; in particular, it is a purpose of the invention to provide a device that is relatively simple and inexpensive to implement and allows to load and unload the capsule with little effort from the user and a limited number of movements, also requiring low maintenance. It is a further aim of the invention to provide a device that can accept medium/high manufacturing tolerances, to accept structural deformations due to the heavy operation, to accept capsules with relatively large dimensional tolerances, to eliminate the need to register/reset every single machine. The present invention is therefore related to a capsule closure device for a coffee capsule machine as defined in essential terms in the annexed claim 1 and, in its additional characters in the dependent claims.

In essence, the device of the invention combines a mechanical unit, that can be manually or automatically actuated, and a hydraulic system, which assists the operation of the mechanical unit. In this way, the most is made of the simplicity and intuitiveness of handling typical of a mechanical system, but the required user's efforts are reduced. The device according to the invention is therefore particularly simple and easy to use, specifically requiring low manual effort by the user.

The device is also simple and inexpensive to implement and fully reliable and requires low maintenance; in terms of production, the invention device allows to accept medium/high manufacturing tolerances, to accept structural deformations due to heavy operation, to accept capsules with relatively large size tolerances, eliminating the need to register/reset every single machine.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional features and advantages of the present invention will appear clear from the description that follows of a non- limiting example of implementation, with reference to the attached drawing figures, wherein:

- Figure 1 is a schematic view of a capsule machine for preparing coffee and other hot beverages, comprising a capsule closure device according to the invention;

Figures 2-5 are schematic views with parts removed for clarity of the respective variants of the device of figure 1. BEST MODE FOR CARRYING OUT THE INVENTION

In Figure 1 is schematically represented, only in its main elements useful for understanding the present invention, a capsule machine 1 for preparing coffee and other hot beverages, operating with coffee in capsules and adapted for preparing other hot beverages by using capsules containing appropriate ingredients.

The machine 1 mainly comprises: a machine body 2 having an entry opening 3 for a capsule 4 and infusion supplying nozzle 5, a capsule closure device 6, acting on the capsule 4 for closing the capsule 4 in an infusion chamber 7 and piercing the capsule 4, and a primary hydraulic circuit 8 for circulating a pressurized hot water flow through the capsule 4 in the infusion chamber 7 and making an infusion.

In more detail, the infusion chamber 7 is delimited by a pair of opposed elements 12, 13, movable with respect to each other and cooperating to define the infusion chamber 7; the device 6 moves at least one of the elements 12, 13 with respect to each other, for example (but not necessarily) along a direction of travel, for selectively closing/opening the infusion chamber 7, closing the capsule 4 in the chamber 7 and piercing the capsule 4 from opposite sides. The element 12 is a hollow holding element, substantially shaped as a cup and having a seat 14, shaped so as to house the capsule 4, and a front access opening 15 to the seat 14; the element 13 is an abutment element that fluid-tightly closes the opening 15 and cooperates with the element 12 to close the seat 14 within the capsule 4 and define the infusion chamber 7. In the embodiment shown in Figure 1, the element 13 is fixed (integral with the machine body 2) while the element 12 is movable, actuated by the device 6.

The elements 12, 13 are provided with respective opposed piercing needle groups 16 adapted to pierce opposite parts of the capsule 4.

The primary hydraulic circuit 8 connects a water tank 18 with the infusion chamber 7, and specifically with an inlet 19 formed in the element 12; along the circuit 8 are arranged in series, between the tank 18 and the chamber 7, a turbine 21, a pump 22, a boiler 23 and a one-way valve 24 configured to permit the circulation of water only towards the inlet 19 and having an opening threshold set at a predetermined pressure value .

The device 6 comprises an operation lever 25 operable by a user, a mechanism 26 connected to the lever 20 for moving the elements 12, 13 with respect to each other, and an hydraulic recovery device 27 that acts on the mechanism 26 for exerting a predetermined closing force on the elements 12, 13.

The mechanism 26 is manually operated by the user by way of the lever 25, which therefore defines a mechanical actuator 28 of the mechanism 26, or by another mechanical or electrical actuator; the mechanism 26, operated by the actuator 28 (lever 25) , moves the elements 12, 13 with respect to each other by a first movement.

In the example shown in Figure 1, but not necessarily, the mechanism 26 comprises two arms 31, 32 hinged one to the other and respectively to a movable member 33 of the hydraulic recovering device 27 and a back portion 34 of the element 12. The mechanism 26 extends between a root end 36, connected to an anchorage wall 35 integral to the machine body 2, and to a free end 37, integrally connected to the element 12. In the example of Figure 1, the device 27 is interposed between the anchorage wall 35 and the mechanism 26, specifically the root end 36 of the mechanism 26. The root end 36 is connected to the anchorage wall 35 through the member 33, to which is hinged; the free end 37 is integrally movable with element 12 for closing the capsule 4 in the infusion chamber 7.

The lever 25 is shaped so that its rotation operated by the user takes the capsule 4 within the machine 1 for being closed between the elements 12, 13. The lever 25 is hinged to the machine body 2 and to one of the arms 31, 32, so that the rotation of the lever 25 results in a movement of the arms 31, 32 with respect to each other and then a translation of the element 12, which leads to closing the elements 12, 13 one against the other.

The hydraulic recovering device 27 acts on the mechanism 26 to actuate a second movement of the elements 12, 13 with respect to each other, so as to exert a predetermined closing force upon the elements 12, 13.

The first movement and the second movement of the elements 12, 13 are actuated independently one from the other by the mechanical or electrical actuator 28 (in this case, the lever 25) and, respectively, from the hydraulic recovering device 27.

The hydraulic recovering device 27 comprises a hydraulically operated variable-volume compensation chamber 40 which houses a movable piston 41 (which is the member 33), and an auxiliary hydraulic circuit 42 which connects the chamber 40 to the pump 22 for varying the volume of the chamber 40 and moving the piston 41.

The compensation chamber 40 may be of various types. In the non-limitative example shown in Figure 1, the chamber 40 is defined inside a casing 43, integrally fixed with the machine body 2 and in particular to the anchorage wall 35; the chamber 40 is delimited by an inner side surface 44 of the casing 43 and has an inlet 45 and an outlet 46, formed for example, through a side wall 47 of the casing 43. The piston 41 is slidably housed inside the chamber 40 and is provided with at least one seal 48, such as a fluidly-tight radial sealing ring cooperating with the surface 44. The circuit 42 comprises: a branch T-joint 50, that joins a primary hydraulic circuit 8 of the machine 1 downstream the pump 22 and upstream a boiler 23 (in other terms, the T-joint 50 is arranged between the outlet of the pump 22 and the inlet of the boiler 23) ; a supply conduit 51 which connects the joint 50 to the inlet 45 of the chamber 40; a recirculation conduit 52 which connects the outlet 46 of the chamber 40 with the tank 18; a control electrovalve 53 controlling the circuit 42, which is installed along the recirculation conduit 52. In the embodiment of figure 1, the compensation chamber 40 is arranged at the attachment end 36 of the mechanism 26 and is interposed between the anchorage wall 35 and the mechanism 26.

The device 6 is controlled by the combined action of the pump 22 and of the electrovalve 53.

The electrovalve 53 is normally open. When the user loads the capsule 4 in the machine 1, acting on the lever 25, also the pump 22 starts and the electrovalve 53 closes; the pump 22 pressurizes the primary circuit 8 (hot) and the auxiliary circuit 42 (cold) , that reach the pressure equal to the opening threshold of the one-way valve 24, providing to the compensation chamber 40 a pressure sufficient for a strong seal . The pressure difference between the capacity of the pump 22 and the regulation of the valve 24 is then the pressure reserved for the infusion of the capsule 4: once passed the opening threshold of the valve 24, the valve 24 opens allowing the passage of water (hot) through the infusion chamber 7.

At the end of the dispense cycle, the pump 22 stops, the electrovalve 53 opens discharging water into the tank 18 and then downloading the pressure from the chamber 40, allowing an easy opening of the mechanism 26.

In the variant of Figure 2, in which details similar or identical to those already described are indicated with the same numbers (and some details are omitted for simplicity) , the hydraulic recovering device 27 is arranged on the movable side of the mechanism 26 and near the infusion chamber 7. In particular, the compensation chamber 40 is formed inside the element 12 and/or the casing 47 is integrally fixed to the element 12. The integration of the compensation chamber 40 with the infusion chamber 7 simplifies the construction of the device 6.

In this case, after actuating the mechanism 26 and closing the elements 12, 13 one against the other, the pump 22 turns on, taking water from the tank 18, the electrovalve 53 closes and then the circuits 8, 42 are put under pressure. The one-way valve 24 ensures to the circuit 42, as previously described, a pressure difference sufficient to close the chamber 7, closing the elements 12, 13 one against the other. In the variant of Figure 3, the hydraulic recovery device 27 is directly installed on the mechanism 26.

In particular, the device 27 is interposed between the two arms 31, 32 of the mechanism 26; the casing 47 in which the compensation chamber 40 is formed is then fixed to the machine body 2 and the chamber 40 houses one or (as shown in figure 3) two movable members 33, in particular two opposed pistons 41, each hinged to an arm 31, 32.

The variant of Figure 4 is totally equal to that shown in figure 2, but the hydraulic recovering device 27 is arranged on the stationary element 13 (piercing disc) , rather than the movable element 12.

In the variant of Figure 5, the mechanism 26 comprises a male- thread/nut-screw system 55 which is formed by a screw 56, driven by a motor 57 (defining an electric actuator 28 of the mechanism 26), and a female-screw 58, acting on the element 12 to translate it back and forth with respect to the anchorage wall 35 and to the element 13; the hydraulic recovering device 27 is arranged (similarly to the version of Figure 2) on the movable side of the mechanism 26, being the compensation chamber 40 axially interposed between the female-screw 58 and the element 12. Also in this case, advantageously, the compensation chamber 40 is formed inside the element 12 and/or the casing 47 is integrally fixed to the element 12. The compensation chamber 40 has a pair of opposite axial shoulders, facing each other, respectively, joined to the female-screw 58 and to the element 12.

Finally, it is understood that to the device here described and illustrated further changes and variations may be made without going beyond the scope of the attached claims.