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US-12616332-B2 - Brewing unit for a machine for preparing coffee

US12616332B2US 12616332 B2US12616332 B2US 12616332B2US-12616332-B2

Abstract

A brewing unit for an automatic machine to make coffee beverages includes a brewing chamber closed at the lower part by a first piston and at the upper part, on the opposite side, by a second piston, a first inlet duct for the heated water, and a first outlet duct for the beverage, communicating respectively with an inlet side and with an outlet side of the brewing chamber, and a filtering element disposed in the brewing chamber.

Inventors

  • Paolo Evangelisti
  • Nicola PIOVAN
  • Davide Bonotto

Assignees

  • De'Longhi Appliances S.R.L. Con Unico Socio

Dates

Publication Date
20260505
Application Date
20210512
Priority Date
20200514

Claims (16)

  1. 1 . A brewing unit ( 10 ; 110 ) for an automatic machine to make coffee beverages, comprising: a brewing chamber ( 12 ) closed at the lower part by a first piston ( 13 ; 113 ) and at the upper part, on the opposite side, by a second piston ( 14 ; 114 ), a first inlet duct ( 15 ; 115 ) for the heated water, and a first outlet duct ( 16 ; 116 ) for the beverage, communicating respectively with an inlet side ( 12 A) and with an outlet side ( 12 B) of said brewing chamber ( 12 ), and a filtering element ( 18 ) disposed in said brewing chamber ( 12 ), a decanting chamber ( 20 ; 120 ) disposed downstream of said filtering element ( 18 ) and upstream of said outlet duct ( 16 ) in the direction of the flow of water, and diversion and guide means ( 40 ) disposed in said decanting chamber ( 20 ; 120 ) and having the function of conveying the flow of beverage so as to divert it and make it follow an indirect path toward an outlet aperture ( 31 ; 131 ) of said decanting chamber ( 20 ; 120 ).
  2. 2 . The brewing unit ( 10 , 110 ) as in claim 1 , wherein said decanting chamber ( 20 ; 120 ) is made in a head portion ( 23 ; 124 ) of a respective piston ( 13 ; 114 ) associated with the outlet side ( 12 B) of said brewing chamber ( 12 ).
  3. 3 . The brewing unit ( 10 , 110 ) as in claim 2 , wherein said head portion ( 23 ; 124 ) is at least partly hollow, defined by a bottom wall ( 25 ; 125 ) and one or more lateral walls ( 26 ; 126 ), and comprising a support portion ( 27 ; 127 ) configured to support said filtering element ( 18 ) in a central zone, and the outlet aperture ( 31 ; 131 ) communicating with said first outlet duct ( 16 ; 116 ).
  4. 4 . The brewing unit ( 10 , 110 ) as in claim 1 , wherein said decanting chamber ( 20 ; 120 ) has a height comprised between 1 and 8 mm.
  5. 5 . The brewing unit ( 10 , 110 ) as in claim 1 , wherein said diversion and guide means ( 40 ) comprise a plurality of pins, or pegs ( 41 ) disposed according to a predefined pattern.
  6. 6 . The brewing unit ( 10 , 110 ) as in claim 1 , wherein said diversion and guide means ( 40 ) comprise at least one annular protrusion ( 42 , 43 ) having the shape of an arc open toward said outlet aperture ( 31 ; 131 ).
  7. 7 . The brewing unit ( 10 , 110 ) as in claim 6 , wherein there is provided only one annular protrusion ( 42 , 43 ) disposed coaxial to said decanting chamber ( 20 ; 120 ).
  8. 8 . The brewing unit ( 10 , 110 ) as in claim 6 , wherein there are provided at least two arc-shaped annular protrusions ( 42 , 43 ) disposed concentric to each other.
  9. 9 . The brewing unit ( 10 , 110 ) as in claim 8 , wherein said at least two annular protrusions ( 42 , 43 ) divide said decanting chamber ( 20 ) into zones having the same size in a radial direction.
  10. 10 . The brewing unit ( 10 , 110 ) as in claim 6 , wherein said at least one, or each, annular protrusion ( 42 , 43 ) extends for a circular sector comprised between 240° and 280°.
  11. 11 . The brewing unit ( 10 , 110 ) as in claim 1 , wherein it comprises a removable insert ( 30 ) on which said diversion and guide means ( 40 ) are provided, which is configured to position itself, during use, in said decanting chamber ( 20 ; 120 ).
  12. 12 . The brewing unit ( 10 , 110 ) as in claim 11 , wherein said insert ( 30 ) has an upper surface ( 32 ) inclined downward between a first side ( 30 A) and a second side ( 30 B), which are opposite with respect to a central axis, wherein the second side ( 30 B) faces, during use, toward the outlet aperture ( 31 ; 131 ).
  13. 13 . The brewing unit ( 10 , 110 ) as in claim 12 , wherein in correspondence with the second side ( 30 B), said insert ( 30 ) comprises a shaped portion ( 39 ), hollowed in said upper surface ( 32 ) and configured to act as a chute and lead-in for the beverage toward said outlet aperture ( 31 ).
  14. 14 . The brewing unit ( 10 , 110 ) as in claim 12 , wherein said decanting chamber ( 20 ; 120 ) and said insert ( 30 ) are provided with respective first ( 35 ) and second coupling members ( 36 ) configured to cooperate with each other and guarantee a correct and stable positioning of the insert ( 30 ) in said decanting chamber ( 20 ; 120 ).
  15. 15 . The brewing unit ( 10 , 110 ) as in claim 1 , wherein said diversion and guide means ( 40 ) are made in a head portion ( 23 ; 124 ) of the piston ( 13 ; 114 ) that is associated with said outlet side ( 12 B) of said brewing chamber ( 12 ).
  16. 16 . An automatic machine to make coffee beverages, comprising: a brewing unit ( 10 ; 110 ) as in claim 1 , a water supply source connected to said first inlet duct ( 15 ; 115 ), and a beverage delivery nozzle connected to said first outlet duct ( 16 ; 116 ).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Section 371 of International Application No PCT/IT2021/050142, filed May 12, 2021, which was published in the English language on Nov. 18, 2021, under International Publication No. WO 2021/229622 A1, which claims priority under 35 U.S.C. § 119(b) to Italian Application No. 102020000010978, filed May 14, 2020. FIELD OF THE INVENTION Embodiments described here concern a brewing unit for an automatic machine for preparing coffee beverages, in particular for preparing an American-type coffee beverage. BACKGROUND OF THE INVENTION Coffee machines are known for preparing American coffee, also called “drip coffee machines”, comprising a water tank, a boiler, a brewing chamber in which a filter is positioned and into which on each occasion the coffee powder is introduced, and a container located under the brewing chamber to receive the beverage. The water heated by the boiler is fed to the brewing chamber where, due to the effect of gravity, it percolates through the coffee powder, extracting the aromatic substances in order to obtain the coffee beverage that is collected in the container. “Drip” type coffee machines have a simple construction, and a low production cost. One disadvantage of traditional machines is that they require manual intervention by the user both to load the coffee powder and also to remove it at the end of the preparation of the beverage. Automatic coffee machines are also known, which comprise a device to feed the coffee powder, a boiler to heat the flow of brewing water, a mobile brewing unit comprising a brewing cylinder closed at one end by means of a first piston and defining a brewing chamber, and a second piston suitable to engage with the mobile brewing cylinder, on the opposite side with respect to the first piston, and to close the brewing chamber. The brewing chamber is connected on one side to a water supply source, and on the opposite side to a duct to deliver the coffee beverage. A filter element suitable to retain the coffee powder is provided between the brewing chamber and the beverage delivery duct. In the automatic machines of the type in question, brewing units are normally used which are substantially the same as those for preparing espresso coffee, since they differ substantially only in the presence/absence of a valve to whip the crema between the filter element and the delivery duct. However, this difference is not sufficient to make it possible to obtain an American type coffee similar to that obtained with traditional percolation machines or “drip machines”. Known types of machines for preparing coffee are described for example in EP0521561A1 and U.S. Pat. No. 5,823,096A. EP0521561A1 describes an automatic machine for preparing espresso or American type coffee, comprising a mobile brewing chamber in which the coffee powder is disposed, and drive means to move a piston to compress the coffee powder. U.S. Pat. No. 5,823,096A describes a machine for preparing coffee comprising a mobile brewing chamber in which the coffee powder is disposed and a piston that is inserted into the brewing chamber to compress the coffee powder. One disadvantage of known solutions is that the use of traditional brewing units entails generating froth in the coffee beverage between the outlet of the brewing chamber and the beverage delivery duct, as is actually required for a high quality espresso type coffee beverage. The small holes in the filter element, together with the pressure that is generated in the brewing chamber, generally comprised between 1 and 3 bar, in fact, are sufficient to generate turbulent motions in the beverage, with consequent formation of air bubbles and froth, which is neither required nor desired in American-type coffee. To solve the problem of froth generation, however, it is not possible to enlarge the diameter of the holes, since this would also entail the transit through them of the coffee powder, which would end up in the beverage dispensed, making it not compliant with the required quality standards. One purpose of the present invention is to provide a brewing unit for a machine for preparing coffee of the automatic type, which is optimized for preparing American-type coffee at low-pressure. Another purpose of the present invention is to provide a brewing unit which allows to obtain a coffee beverage with characteristics similar to those obtainable by percolation machines of the traditional type. Another purpose is to provide a super-automatic coffee machine, optimized for preparing American coffee. Another purpose is to provide a machine for preparing coffee beverages which is reliable and does not require the manual loading and unloading of the coffee powder by the user. The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages. SUMMARY OF THE INVENTION The present invention is set f