DEVICE FOR PREPARING A DOSE OF GROUND COFFEE POWDER

Abstract

The device for preparing a dose of ground coffee powder ready for infusion comprises a cup provided with a gripping handle and housing a filter containing said dose of ground coffee powder, a coupling support in which the cup is coupled separably, and a pressing piston that is engageable in the filter for pressing the dose of ground coffee powder, the pressing piston having anti-detachment means configured to prevent the detachment of the pressed dose of ground coffee powder from the walls of the filter when the pressing piston disengages the filter.

Claims

1. A device for preparing a dose of ground coffee powder ready for infusion, comprising a cup provided with a gripping handle and housing a filter containing said dose of ground coffee powder, a coupling support in which said cup is coupled separately, and a pressing piston that is engageable in said filter for pressing said dose of ground coffee powder, wherein said pressing piston has an anti-detachment unit configured to prevent the detachment of said pressed dose of ground coffee powder from walls of said filter when said pressing piston disengages said filter.

2. The device according to claim 1, wherein said anti-detachment unit comprises a filtering element that is selectively permeable to the air but not to said ground coffee powder.

3. The device according to claim 2, wherein said filtering element is fitted to a head of said pressing piston.

4. The device according to claim 3, wherein said anti-detachment unit further comprises air channels in said pressing piston that terminate on the head of said pressing piston behind said filtering element.

5. The device according to claim 4, wherein said air channels are permanently connected to the outer environment at atmospheric pressure.

6. The device according to claim 1, wherein said support comprises a vertical cylindrical conveying conduit conveying said dose of ground coffee powder to said filter.

7. The device according to claim 6, wherein said pressing piston is positioned inside said vertical cylindrical conveying conduit and comprises a scraping perimeter gasket on the inner side of said vertical cylindrical conveying conduit.

8. The device according to claim 7, wherein said scraping perimeter gasket is configured to form a seal with the inner side of said vertical cylindrical conveying conduit and with the inner side of a cylindrical wall of side filter positioned on a downward axial extension of the inner side of said vertical cylindrical conveying conduit.

9. The device according to claim 6, further comprises a coffee grinder for coffee beans comprising a dispensing slide dispensing ground coffee having an outlet into said conveying conduit.

10. The device according to claim 2, wherein said filtering element comprises a flat support having a distribution of first holes and a mesh fixed to the flat support and having a distribution of second holes of a lesser dimension than the first holes.

11. The device according to claim 10, wherein said second holes have a diameter comprised between 0.05 mm and 0.20 mm.

12. The device according to claim 1, wherein said pressing piston is movable to engage with and disengage from said filter.

13. The device according to claim 1, wherein said cup is movable to engage and disengage said pressing piston with and from said filter.

14. The device according to claim 13, wherein at least one of a manual or an automatic movement unit is provided with at least one of said pressing piston or said cup engaging and disengaging said pressing piston with and from said filter.

15. A coffee machine comprising the device preparing a dose of ground coffee powder according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further characteristics and advantages of the invention will more fully emerge from the description of a preferred but not exclusive embodiment of the device for preparing a dose of ground coffee powder ready for infusion according to the invention, illustrated by way of indicative and non-limiting example in the accompanying figures of the drawings, in which:

[0035] FIG. 1 shows a coffee machine that incorporates a device in accordance with an embodiment of the invention;

[0036] FIGS. 2 and 3 show a vertical section of the device with the pressing piston disengaged and engaged in the cup;

[0037] FIG. 4 shows a perspective view from below of the sectioned pressing piston;

[0038] FIG. 5 shows a perspective view from below of the sectioned pressing piston with the filtering element dismantled;

[0039] FIGS. 6a, 6b and 6c show a plan and raised side view of the filtering element, and an enlarged detail thereof;

[0040] FIG. 7 shows a perspective view of the filtering element;

[0041] FIG. 8 shows the filtering element sectioned orthogonally along a diametric plane; and

[0042] FIG. 9 shows an enlarged detail of FIG. 6.

DETAILED DESCRIPTION

[0043] With reference to the figures, a device 2 is illustrated for preparing a dose 100 of ground coffee powder ready for infusion.

[0044] The device 2 comprises a pressing piston 15 and a cup 3 provided with a gripping handle 13 and housing a filter 4 having delimiting walls 4a, 4b delimiting an open collecting chamber 101 for collecting the dose of ground coffee powder 100. The bottom wall 4a of the filter 4 has a plurality of uniformly distributed holes through which the coffee infusion passes that then flows to least one dispensing spout 14 of the infused coffee provided at the base of the cup 3.

[0045] The side wall 4b of the filter 4 that delimits the opening of the chamber 101 is cylindrical and has the maximum diameter of the filter 4.

[0046] The cup 3 is coupled separably with a support 7, in particular with a bayonet coupling system comprising outer fins 11 of the cup 3 that are lockable in suitable guides 12 provided in the support 7 by a roto-translation movement upwards of the cup 3.

[0047] The pressing piston 15 is engageable to close the open chamber 101 to press the dose of ground coffee powder 100.

[0048] Advantageously, the pressing piston 15 has an anti-detachment means of the pressed dose of ground coffee powder 100 from the walls 4a, 4b of the filter 4 that delimit the chamber 101.

[0049] The anti-detachment means, as will be seen better below, is operational when the pressing piston 15 disengages the filter 4.

[0050] The anti-detachment means comprises a filtering element 102 that is selectively permeable to the air but not the ground coffee present in the filter 4.

[0051] The filtering element 102 is fitted to the head 15a of the pressing piston 15.

[0052] The filtering element 102 specifically comprises a slightly convex flat support 102a having a uniform or non uniform distribution of first holes 102b, and a mesh 102c fixed to the flat support 102a and having a uniform or non uniform distribution of second holes 102d of smaller dimension than the first holes 102b.

[0053] The flat support 102a has the shape of a disk and is fixed concentrically to the head 15a, which is also circular in shape, of the pressing piston 15.

[0054] More precisely, the flat support 102a is housed in a circular recess 15c of joined shape provided on the head 15a of the pressing piston 15.

[0055] The depth of the circular recess 15c is equal to the thickness of the flat support 102a, which is thus flush with the outer surface of the head 15a of the pressing piston 15.

[0056] The flat support 102a has in turn a concentric circular recess 102f that houses the mesh 102c, which is also flat and circular and has a thickness that is less than the thickness of the flat support 102a.

[0057] The depth of the circular recess 102f is equal to the thickness of the mesh 102c that is thus arranged flush with the outer surface of the flat support 102a.

[0058] The second holes 102d have a diameter comprised between 0.05 mm and 0.20 mm. The diameter of the second holes 102 is less than the diameter of the grains of coffee powder that can thus not traverse the mesh 102c.

[0059] The first holes 102b have a dimension comprised between 0.8 mm and 3 mm.

[0060] The flat support 102a has a thickness comprised between 0.4 mm and 0.6 mm whereas the mesh 102c has a thickness comprised between 0.05 mm and 0.7 mm.

[0061] Centrally, the flat support 102a and the mesh 102c have a raised flared hole 102e for fixing the filtering element 102 by a screw 104 to the head 15a of the pressing piston 15.

[0062] The filtering element 102 can be made of metal, in particular stainless steel, or also of another material.

[0063] For greater dimensional precision, the calibrated holes 102b, 102d present on the filtering element 102 can be made by photo-engraving technique.

[0064] In order to assemble the mesh 102c on the support 102a, the outer perimeter edge of the mesh 102c can be welded continuously and the inner perimeter edge of the mesh 102c can be spot welded to the wall of the recess 102f.

[0065] Other assembly technologies for assembling the mesh 102c on the support 102a are possible, for example perimeter heading can be performed.

[0066] The anti-detachment means also comprises air channels 103 that terminate on the head 15a of the pressing piston 15 behind the filtering element 102. The air channels 103 can be permanently connected to the outer environment at atmospheric pressure.

[0067] Alternatively, the air channels 103 can be closed inside the pressing piston 15.

[0068] In the illustrated case, the air channels 103 terminate on the head 15a of the pressing piston 15, in particular at a further drop 15d of the bottom of the recess 15c.

[0069] The drop 15d is circular and concentric on the recess 15c and delimits an air chamber 15e precisely behind the filtering element 102.

[0070] The support 7 has a vertical cylindrical conduit 16 for conveying the dose of ground coffee powder 100 to the filter 4.

[0071] The pressing piston 15 is positioned inside the vertical cylindrical conveying conduit 16 and has a scraping perimeter gasket 17 for scraping the inner side 16a of the vertical cylindrical conveying conduit 16.

[0072] The scraping gasket 17 removes the coffee powder beans that remain attached to the inner side 16a of the vertical cylindrical conveying conduit 16 making the beans fall directly into the filter 4.

[0073] The scraping perimeter gasket 17 is configured to form a tight seal with the inner side 16a of the vertical cylindrical conveying conduit 16 and with the inner side of the cylindrical side wall 4b of the filter 4 positioned precisely on the axial downward extension of the inner side 16a of the vertical cylindrical conveying conduit 16. The conveying conduit 16 and the cylindrical side wall 4b of the chamber 101 are positioned continuously in relation to one another so as not to leave escape paths open for the coffee powder transiting to the filter 4.

[0074] Preferably, along the conveying conduit 16, an outlet 10 opens of a dispensing slide 9 of ground coffee connected to a grinder 8.

[0075] The device 2, as illustrated, can be incorporated into a coffee machine 1. Nevertheless, it must be pointed out that, unlike what has been illustrated, the device 2 can also be a structurally and functionally autonomous unit that is completely separate from the coffee machine 1.

[0076] The pressing piston 15 can even be specially structured to also act as an infusion piston.

[0077] In the solution illustrated, it is the piston 15 that is moved to perform pressing of the dose of ground coffee powder when the cup 3 is coupled with the support 7.

[0078] For this purpose, a linear movement mechanism is provided of the pressing piston 15 in the conveying conduit 16.

[0079] This mechanism is able to actuate reversibly the pressing piston 15 between a pressing position in which the pressing piston 15 is inside the cup 3 and a rest position in which the pressing piston 15 is above the outlet 10 of the slide 9.

[0080] The movement mechanism comprises a rotatable manual control lever 19 and a transmission that transforms rotation of the control lever 19 in a vertical translation of the pressing piston 15.

[0081] The pressing force exerted by the piston 15 can be regulated by elastic friction exerted by an elastic clutch that connects the lever 19 to the transmission.

[0082] The transmission can comprise specifically a gear formed by a vertical rack 20 that is solidly constrained to the pressing piston 15 and an arc of a cogwheel 21 supported rotationally by a horizontal mechanical axis 22 connected to the control lever 19 and engaging the vertical rack 20.

[0083] Naturally, it is possible to provide alternatively a non-manual but automatic or semiautomatic control of the pressing piston.

[0084] In order to perform pressing of the dose of ground coffee powder, in other solutions it is possible to provide moving of the cup 3, in particular by moving the support 7 thereof whilst the pressing piston 15 remains stationary.

[0085] The device 2 performs a work cycle comprising in sequence a first loading step of loading the dose of coffee powder into the filter 4, a second step of descent of the pressing piston 15, and a third step of lifting the pressing piston 15 above the outlet 10 of the slide 9.

[0086] In the first step of the work cycle, the pressing piston 15 is in a raised position above the outlet 10 of the slide 9.

[0087] Once the dose of ground coffee has been dispensed to the filter 4 housed in the cup 3 coupled with the support 7, the user can rotate the control lever 19 in the direction that causes vertical downward translation of the pressing piston 15 in the conveying conduit 16.

[0088] The pressing piston 15 in the initial step of the descent with the gasket 17 scrapes and cleans the inner side 16a of the conveying conduit 16 and in the final step of the descent engages in the filter 4 and performs pressing of the dose of ground coffee powder present in the filter 4.

[0089] Normally, before being able to uncouple the cup 3 from the support 7 and being thus able to couple the cup 3 with the end of the infusion unit of the coffee machine 1, the pressing piston 15 is returned to the initial position raised above the outlet 10 of the slide 9.

[0090] During the ascent of the pressing piston 15, a progressively growing volume opens between the head 15a of the pressing piston 15 and the pressed dose of ground coffee powder present in the filter 4.

[0091] During the ascent of the pressing piston 15, the gasket 17 of the pressing piston 15 further creates a tight seal against the cylindrical wall 16a of the conveying conduit 16.

[0092] Despite the seal exerted by the gasket 17, in this space of constantly increasing volume no persistent vacuum is created that, if present, could generate significant upward suction force on the pressed dose of ground coffee powder.

[0093] In fact, as the volume of said space increases, the decrease of inner pressure is promptly compensated by the inflow of air thereinto drawn through the air channels 103 and the filtering element 102.

[0094] The pressed dose of ground coffee powder does not therefore detach from the walls 4a, 4b of the filter 4 and does not promote the formation of preferential paths of the water through the detachment zones during infusion.

[0095] In practice, with the present invention a device is provided that, without dirtying, enables a dose of ground coffee powder to be loaded and pressed correctly in the filter 4 of the cup 3 ready to be subjected to a correct infusion procedure.

[0096] The device thus conceived is susceptible of numerous modifications and variants falling within the scope of the inventive concept; moreover, all the details are replaceable by technically equivalent elements.

[0097] In practice, the materials used, as well as the dimensions, can be any according to the needs and the state of the art.