U.S. patent application number 09/729792 was filed with the patent office on 2001-12-13 for method and device for preparing espresso coffee.
Invention is credited to Bonanno, Francesco.
Application Number | 20010050002 09/729792 |
Document ID | / |
Family ID | 11438141 |
Filed Date | 2001-12-13 |
United States Patent
Application |
20010050002 |
Kind Code |
A1 |
Bonanno, Francesco |
December 13, 2001 |
Method and device for preparing espresso coffee
Abstract
A method for preparing espresso coffee or similar drinks in
manual or automatic machines, by causing a forced flow of boiling
water to pass through a percolation chamber containing coffee
powder, in which an adjustable back pressure is created in the
percolation chamber to increase the time of contact between the
powder and the water. A device for preparing espresso coffee or
similar drinks, comprising hot water generating means, a
percolation chamber traversed by hot water and intended to contain
coffee powder, and a drink exit conduit, in which the conduit is in
the form of a nozzle, the outlet of which is throttled by
adjustable means.
Inventors: |
Bonanno, Francesco; (Gaggio
Montano, IT) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.
624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Family ID: |
11438141 |
Appl. No.: |
09/729792 |
Filed: |
December 6, 2000 |
Current U.S.
Class: |
99/275 ;
99/323.1; 99/323.3; 99/452; 99/454; 99/483 |
Current CPC
Class: |
A47J 31/60 20130101;
A47J 31/0605 20130101; A47J 31/0657 20130101; A47J 31/4496
20130101; A47J 31/0663 20130101 |
Class at
Publication: |
99/275 ; 99/452;
99/454; 99/323.1; 99/323.3; 99/483 |
International
Class: |
A23L 002/54; A01J
011/00; A23C 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 7, 2000 |
IT |
BO2000A000051 |
Claims
1. A method for preparing espresso coffee or similar drinks in
manual or automatic machines, by causing a forced flow of boiling
water to pass through a percolation chamber containing coffee
powder, characterised in that an adjustable back pressure is
created in the percolation chamber to increase the time of contact
between the powder and the water.
2. A method as claimed in claim 1, characterised in that on its
exit from the percolation chamber the liquid is throttled within an
air-rich environment to facilitate creation of a creamy
emulsion.
3. A device for preparing espresso coffee or similar drinks,
comprising hot water generating means, a percolation chamber
traversed by hot water and intended to contain coffee powder, and a
drink exit conduit, characterised in that the conduit is in the
form of a nozzle, the outlet of which is throttled by adjustable
means.
4. A device as claimed in claim 3, characterised in that the nozzle
opens into an atmospheric pressure chamber which communicates with
the outside and in which the liquid falling from a delivery spout
is collected.
5. A device as claimed in claim 3, characterised in that said
atmospheric pressure chamber comprises, coaxial with the nozzle, a
threaded seat into which a member provided with externally located
operating means and carrying said throttling means is screwed.
6. A device as claimed in claim 5, characterised in that said
throttling means are a rubber nosepiece.
7. A device as claimed in claim 5, characterised in that said
throttling means are a needle-shaped pin.
8. A A device as claim 3, characterised by comprising an expansion
chamber communicating with the nozzle.
9. A device as claimed in claim 8, characterised in that the nozzle
is formed within an axially bored bush comprising an outer
circumferential groove communicating with the axial bore of the
nozzle via a radial duct.
10. A device as claimed in claim 9, characterised in that said
radial groove communicates with the expansion chamber.
11. A device as claimed in claim 8, characterised in that the
expansion chamber is a cylindrical chamber open outwards at one end
and containing a sealed piston opposed by a spring.
Description
[0001] This invention relates to the preparation of espresso
coffee, or Italian coffee, by percolating boiling water through a
certain lightly pressed quantity of ground roasted coffee in powder
form.
[0002] It is equally suitable for preparing espresso coffee
starting from a single-measure or multi-measure coffee sachet
formed of heat-resistant material able to act as a filter.
[0003] The invention is also suitable for preparing drinks from
coffee substitutes, such as barley or the like.
[0004] Hereinafter, reference will be made exclusively to coffee,
this term also embracing its substitutes.
[0005] Espresso coffee preparation machines for domestic or bar use
comprise a hot water generator feeding a percolation chamber
containing the coffee powder.
[0006] Said chamber commonly comprises the lower filtering wall,
for example of perforated stainless steel, and is connected below a
top piece through which the boiling water is fed.
[0007] Below the filtering wall there is defined a collection
chamber for the percolated product which flows to the outside
through a spout below which the cup is placed.
[0008] The quality of the product obtained depends both on the
quality of the powder and on the ability of the operator, who has
to press the powder to the correct extent to achieve uniform
distribution of the percolating water through the entire coffee
mass.
[0009] A commonly observed indicator in the user's judgement of the
quality of the espresso coffee is the presence of froth, ie a
creamy phase above the surface of the liquid phase.
[0010] The need to optimize the percolation stage, on which for
equal powder quality the quality of the finished product depends,
is obvious.
[0011] In the known art, in spite of full operator attention, there
is a limit to the degree of utilization of the powder, as almost
inevitably passages of lesser density form in the powder mass,
creating preferential passageways for the hot water, which hence
does not sufficiently traverse certain parts of the powder.
[0012] Said drawback is also present in automatic machines, in
which the manner in which the powder is fed to the percolation
chamber often does not ensure uniform water passage through the
whole of the coffee powder.
[0013] The object of this invention is to propose and provide an
espresso coffee preparation method and device which ensures maximum
powder utilization and can be easily adapted for the use of any
starting substance.
[0014] The invention is aimed at both manual machines and automatic
machines.
[0015] The invention is primarily based on the fact of creating a
back pressure of desired value which slows down the flow of the hot
water, giving it time to expand throughout the entire mass of
powder.
[0016] According to the invention, said back pressure is preferably
associated with an expansion chamber positioned between the liquid
exit nozzle and the coffee delivery spout, the liquid entering this
chamber with a certain speed to mix with the air and produce a
creamary emulsion giving an enhanced appearance to the drink.
[0017] The method of the invention is implemented by devices easily
associated with manual or automatic machines.
[0018] Said devices enable the object of the invention to be
attained by virtue of the characteristics stated in the claims.
[0019] The constructional and functional characteristics of the
invention will be apparent from the ensuing detailed description
illustrating its various methods of implementation, given by way of
non-limiting example with the aid of the figures of the
accompanying drawings.
[0020] FIG. 1 is a partly sectional side view of a percolation
chamber suitable for manual machines, in it most simple
embodiment.
[0021] FIG. 2 shows an improved embodiment of the percolation
chamber of FIG. 1.
[0022] FIG. 3 shows an embodiment of the invention which can be
easily associated with an automatic machine.
[0023] FIG. 4 is an enlarged detail of FIG. 3.
[0024] FIG. 5 shows a possible variant of FIG. 4.
[0025] FIG. 1 shows the top piece 1 of a normal espresso coffee
preparation machine, to which the percolation chamber is fixed by
the known bayonet connector 2.
[0026] This chamber comprises a cup piece 4 provided with a handle
5 and defining a chamber 3 provided with a removable perforated
wall 7.
[0027] The wall 7 bounds an underlying chamber 8 for collecting the
percolated product, from which it emerges through the nozzle 9.
[0028] Below the nozzle there is provided an emulsifying chamber 10
which is closed by a plug 11 axially bored at 12, and communicates
with the spout 13 through which the drink is delivered to the
cup.
[0029] The emulsifying chamber 10 comprises a threaded seat 14
coaxial with the nozzle 9, and into which a threaded member 15
provided with operating means 16 is screwed.
[0030] The member 15 is axially hollow to receive an axial pin 17
possibly by way of elastic means 18. The pin 17 is provided at its
end with a nosepiece for closing the nozzle 9, which nosepiece can
be an elastomeric ball 19 or a steel needle 190 (as in FIG. 5).
[0031] The nosepiece 19, 190 can be rested against the nozzle 9 and
be kept pressed by the elastic means 18, or can be positioned at
the desired distance from said nozzle by screwing the member 15
into its seat to a greater or lesser extent.
[0032] FIG. 2 comprises all the means shown in FIG. 1, indicated by
the same reference numerals.
[0033] The improved embodiment of FIG. 2 also comprises an
expansion chamber 20 communicating with the duct of the nozzle 9
via a branch 21.
[0034] The chamber 20, of circular cross-section, comprises a
sealed piston 22 maintained at that end close to the nozzle 9 by a
spring 23 opposed by the plug 24. The plug 24 is bored at 25 and
communicates with the outside.
[0035] FIGS. 3, 4 and 5 show executive details of the
aforedescribed embodiments, suitable particularly but not
exclusively for implementing the invention in automatic
machines.
[0036] Those details of FIGS. 3 to 5 corresponding to the details
of FIGS. 1 and 2 are indicated by the same reference numerals.
[0037] The reference numeral 100 indicates a portion of the body of
the automatic espresso coffee preparation machine to which the
invention is applied.
[0038] In the illustrated example said portion 100 comprises the
hot water delivery duct 101, in front of which the piece 102 is
fixed such that the axis of the nozzle 9 is aligned with 101.
[0039] This nozzle is provided within a bush 90 having an axial
bore and a circular groove 91 positioned in front of the expansion
chamber 20 and communicating with the axial bore of the nozzle 9
via a branch 21.
[0040] Below the nozzle 9 there is an emulsifying chamber 10 which
is closed by a plug 11 bored axially at 12, and communicates with
the drink delivery spout 13.
[0041] The emulsifying chamber 10 comprises a threaded seat 14
coaxial with the nozzle 9, and into which a threaded member 15
provided with operating means 16 is screwed.
[0042] The member 15 is axially hollow to receive an axial pin 17
possibly by way of elastic means 18. The pin 17 is provided at its
end wash a nosepiece in the form of an elastomeric ball 19 for
closing the nozzle 9.
[0043] The ball 19 can be rested against the nozzle 9 and be kept
pressed by the elastic means 18, or can be positioned at the
desired distance from said nozzle by screwing the member 15 into
its seat to a greater or lesser extent.
[0044] The same applies if a needle 190 is provided instead of the
ball.
[0045] In the variant of FIG. 5, the throttling means for the
nozzle 9 are in the form of a needle 190.
[0046] The invention operates in the following manner. The known
procedure is used for coffee percolation.
[0047] According to the invention, by using the operating member 16
to adjust the thrust of the throttling element 19, 190 against the
nozzle 9 or its distance from the nozzle 9, a back pressure is
created in the percolation chamber 3 which increases the contact
time between the hot water and the coffee powder, to ensure
optimium utilization of this latter.
[0048] A drink is hence obtained of quality comparatively much
better than that obtained with the known system, meaning that for
equal coffee powder quality a better drink is obtained, or that for
equal powder quality less powder can be used.
[0049] The final drink appearance is rich in cream in that in
passing through the gap between the nosepiece 19 and the nozzle at
great speed, the drink mixes with the air contained in the chamber
10, to emulsify and assume the enhanced creamy appearance which
besides facilitating development of the aroma, gives quality to the
drink.
[0050] Perfect execution of the process depends to a substantial
extent on the diameter of the nozzle 9, which must be as small as
possible compatible with the requirements of throughput and the
risk of clogging.
[0051] The embodiments shown in FIGS. 2 and 4 considerably reduces
the risk of clogging.
[0052] In this respect, during percolation, that portion of
percolated liquid which initially descends and is the least rich in
solid particles fills the chamber 20 by overcoming the elastic
resistance of the piston 22, which moves towards the left to
compress the spring 23.
[0053] When not water feed is halted at the end of the process, the
liquid contained in the chamber 22 is expelled through the nozzle 9
to clean it of any solid parts, while at the same time it acts
below the perforated wall 7 to free any perforations clogged with
coffee powder.
* * * * *