Note: Descriptions are shown in the official language in which they were submitted.
2048631 0s566
Device for Frothinq and/or Emulsifyinq, While at the Same
Time Heatinq, a Liauid, Such as Milk, by the Introduction
of Superheated Steam
This invention relates to a device for frothing
and/or emulsifying, while at the same time heating, a
liquid, such as milk, by the introduction of superheated
~ steam through a steam pipe connected to a steam genera-
; ting means, the steam pipe having at its free end at
least one steam discharge nozzle.
.
Devices of this type are used in coffee makers,
espresso makers, tea makers or similar appliances which
are equipped with a steam generating means, such as a
steam boiler, and include an additional device for the
withdrawal of superheated steam.
The use of superheated steam affords the advantage
of a very rapid heating of beverages, such as coffee,
tea, milk, cocoa or the like, including soups and other
foods and liquids. Special cooking vessels are not
necessary for this purpose; the material may be heated
directly in the dish in which it is served, for example,
a cup, a drinking glass, a plate, etc.
However, a very popular preparation nowadays is a
mixed drink known as "cappuccino" which is made of hot
milk froth and espresso. The milk is heated by the
,
introduction of steam. This is intended to froth up the
milk and emulsify it with steam and, if possible, also
with a supply of alr. The superheated steam is
introduced into the still flowable milk and emulsified
with it to a gaseous condition. As this occurs, the
superheated steam heats the milk, condenses in the milk
and should combine with it to form an emulsion as fine as
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possible and eventually a relatively firm and stable
froth.
According to the current state of the art, attempts
are made to inject superheated steam through a steam
nozzle into a vessel containing cold milk. In this pro-
cess, the user is required to insert the steam nozzle in
the milk and a~itate it therein so as to accomplish an
optimum flow and dosage of steam and air. ~his neces-
sitates a great deal of experience in order to prevent
the milk from spattering and the hot steam from being
discharged into the surroundings.
Devices are known which are intended to facilitate
this process. Thus~ for example, DE 35 38 041 A1 dis-
closes a construction in which the steam discharge nozzle
is surrounded by a vacuum chamber through which addi-
tional fresh air is to be aspirated. Further, DE 1 157
750 B1 shows a device to be likewise mounted downstream
of the steam discharge nozzle, in which the superheated
steam is intended to perform rotary movements by passing
~through a helically extending steam duct. A still
further similar construction is known from EP 0 287 906
A2.
It is an object of the present invention to provide
a device for frothing and/or emulsifying, while at the
same time heating, a liquid, with which the result aimed
at may be accomplished more rapidly, more consistently
and thus in an improved way, which is easier to manipu-
late and, above all, does not require special skills.
According to the present invention, this object is
accomplished in a device of the type initially referred
to in that the steam discharge nozzle or nozzles is or
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are associated with at least one member which is driven
to rotate by means of the superheated steam exhausted
from the steam discharge nozzle or nozzles.
By means of the superheated steam exhausted from the
steam discharge nozzle at a relatively high pressure, the
member associated with the steam discharge nozzle is
caused to rotate at high velocity. This makes it
possible for steam, air and the liquid to be treated to
emulsify rapidly. As a result, a particularly creamy
and, owing to the high air content, stable froth of milk
is readily obtainable. The milk froth attains a consis-
tency similar to the consistency of whipped cream. This
provides ideal conditions for the preparation of
"cappuccini" and similar beverages. In the device of the
present invention, this result is achieved in that the
liquid to be treated is acted on mechanically-physically
and at the same time thermally. By virtue of the
mechanical-physical action (that is, the rotary motion)
on milk, for example, the constituents of milk, in par-
ticular fat and protein, are broken up into minutest
particles. In combination with the aqitation process and
the introduction of finest steam and air, the emulsifying
process proceeds particularly rapidly, and the result is
~ highly stable owing to thorough blending.
;~ ~owever, it is not only in the frothing up of milk
that the construction of the invention yields very good
results. The rotary member is highly effective also in
mixing, blending, emulsifying, frothing and the like, of
other hot beverages, such as cocoa, instant coffee or
instant tea, including also instant soups.
In this construction, the rotary member may be a
structure resembling a turblne wheel. It is only impor-
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20~8 6 30~566
tant that the drive be accomplished solel by the super-
heated steam impinging on the vanes of t}e turbine wheel
and that the wheel perform an air intake function and, in
addition, a certain mixing function in tie emulsion or
the liquid.
In a preferred further development of the subject
matter of the invention, the pivot shaft of the turbine
wheel may be disposed on the extended cent:al axis of the
steam pipe. In this arrangement, a nozzl~ body diverging
concentrically and conically towards the free end and
accommodating the steam discharge nozzle and the pivot
shaft may be attached to the downstream esd of the steam
pipe. Preferably, the nozzle body should provide an end
shield for the turbine wheel. In this ~rrangement, an
emulsifying chamber may be formed between the end shield
and the turbine wheel. In this emulsifyir~ chamber, air,
steam and the liquid to be emulsified a e subjected to
turbulence for intimate mixing.
A particularly effective configurati~n of the sub-
ject matter of the invention results if t^e nozzle body,
the turbine wheel attached thereto and -he emulsifying
chamber are embraced by an emulsifyinc cage. This
emulsifying cage should be largely open i?. the direction
D in which steam or emulsion is dischargec, and it should
have air intake ports on the periphery of he emulsifying
chamber.
For retrofitting coffee and espres30 makers, the
nozzle body may be a push-on or scr~-on structure
attached to the end of the steam pipe.
,,
The nozzle body should include at least one steam
duct terminating in at least one steam d scharge nozzle
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20~863~
05566
in the end shield of the noz~le body in the vane region
of the turbine wheel.
A particularly preferred nozzle body structure
results if it is comprised of a nozzle ~ody bell and a
nozzle body core, with the steam duct or ducts being
formed between the conical outer wall of the nozzle body
core and the corresponding conical inner wall of the
nozzle body bell fitting over the nozzle body core.
Embodiments of the present invention will now be de-
scribed in more detail in the following with reference to
the accompanying drawings.
In the drawings,
FIGS. 1 to 4 are an exploded representation illus-
trating schematically a device according to the inven-
tion, comprisinq a push-on head (FIG. 1), a nozzle body
; (FIG. 2), a rotary member (FIG. 3), and a bolt serving as
a pivot shaft for the rotary~member (FIG. 4);
FIG. 5 shows the device of FIGS. 1 to 4 in assembled
condition;
FIGS. 6 to 10 show a device of the invention illus-
trating a second embodiment; FIG. 6 shows a nozzle body
~comprised of two parts;
FIG. 7 shows a turbine wheel;
~;FIG. 8 shows an emulsifying cage within which the
turbine wheel rotates;
FIG. 9 is a view of the emulsifying cage of FIG. 8,
as seen looking from the direction A;
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FIG. 10 is a view of the turbine wheel of FIG. 7;
and
FIG. 11 shows the device of FIGS. 6 to 10 in assem-
bled condition.
According to the embodiments illustrated in the
drawings, the superheated steam produced, for example, in
the high-temperature water heater/steam generator of a
coffee maker/espresso maker is passed - under the control
of a steam outlet valve, not shown, provided on the
appliance - through a steam pipe R and a steam passage 11
formed in a push-on head 1 to a nozzle body 10 where it
is distributed in steam ducts 13 to be exhausted from the
nozzle body 10 through steam discharge nozzles 12.
In an axial extension of the central axis M of the
steam pipe R or the steam passage 11 in the push-on head
1, a socket-type/internally-threaded opening 19 is pro-
vided in the nozzle body 10. A bolt 16 having a thread
18 and a pivot shaft 17 is in threaded engagement with
this internal thread 19. A rotary member providing the
turbine wheel 14 is seated on the pivot shaft 17 in a
pivot bearing t4.1 . The turbine wheel 14 comprises a
rotor 14.2 on which turbine vanes 14.3, shown only
schematically, are disposed.
The nozzle body 10 is a rotationally symmetrical
body diverglng conically towards its free end. It forms
an end shield 15 at its free end. In this end shield 15,
one or several steam discharge nozzles 12 are arranged
such that the steam exhausted from them impinges on the
turbine vanes 14.3 of the turbine wheel 14 at maximum
possible velocity. This causes rotatian of the turbine
wheel 14 about the pivot shaft 17 on the bolt 16.
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FIGS. 1 to 4 show the individual ccmponents 1, 10,
14 and 16 of the device of the invention; FIG. 5 shows
the device in assembled, operative condition.
The mode of operation of this device is as follows:
The steam passing throuqh the steam pipe R, the
steam passage 11, the steam ducts 13 and the steam dis
charge nozzles 12 and impinging on the t~rbine vanes 14.3
of the turbine wheel t4 causes the t~rbine wheel to
rotate at high velocity. On immersing t:~e device of the
invention with its turbine wheel 14 in a beverage, such
as milk, the rotating turbine wheel 14 will mechanically
break up fat, protein and similar partic'es contained in
the milk, while on the other hand causins intimate mixing
of the milk with steam and laterally induced air, this
process taking place in the emulsifying chamber EK formed
between the end shield 15 on the underside of the nozzle
body 10 and the rotor 14.2. The user is merely required
to make sure that the end shield 15 o the device is
"placed down" on the milk surface. If this requirement
is satisfied, a creamy and stable milk froth i9 obtained
reliably and rapidly, which is particularly well suited
for the preparation of "cappuccini", chocolate and simi-
lar beverages.
FIGS. 6 to 11 of the drawings show in all essential
details a second embodiment o the subject matter of the
invention.
In this embodiment, the nozzle body 20 includes an
integrally formed push-on head 21 for pushing or screwing
down or similarly fastenlng the device to the steam pipe
which is conne¢ted to the high-temperature water
heater/steam generator. The push-on head 21 may be
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provided, for example, with a clamp-type locking means 22
for attachment to the steam pipe by clam?ing. In this
arrangement, the clamp-type locking means 22 has to be
configured such as to serve at the same time a sealing
function. It will be understood that the means 22 may
equally well be a threaded body with which the device is
screwed down on the steam pipe.
In this embodiment, the push-on head 21 of the
nozzle body 20 is integrally formed with a nozzle body
bell 23 diverging conically towards the free end of the
nozzle body 20. The nozzle body bell 23 has an inner
wall 26 which diverges likewise conically towards the
outside and towards the free end, the divergent section
starting approximately at the point where the superheated
steam is discharged from the steam pipe. A nozzle body
core 24 the conical outer wall 25 of which is conformed
to the conical inner wall 26 of the nozzle body bell 23
is inserted into the tapered widening of the nozzle body
bell 23.
Either the inner wall 26 or the outer wall 25 incor-
porates one or several steam ducts 27. It is also con-
ceivable to maintain a spacing between the outer wall 25
and the inner wall 26, the spacing extendi~g circumferen-
tially along the entire length. The steam ducts 27
terminate in one or several steam discharge nozzles 28
embedded in an abutment ring 34 formed on the nozzle body
core 24.
FIGS. 7 and 10 show a turbine wheel 29. A rotor
29.2 carryin~ turbine vanes 29.3 on its periphery extends
from a central pivot bearing 29.1. hith its pivot
bearing 29.1, the turbine wheel 29 is adapted to rotate
on a pivot shaft 31 which is firmly seated in a bore 35
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2 a~86~ ~66
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in the nozzle body core 24. In this arrangement, the
axis of the bore 35 or of the pivot shaft 31 may lie on
the extension of the central axis M of the steam pipe or
the nozzle body 20.
The pivot shaft 31 is anchored in positive
engagement in the bore 35 in the nozzle body core 24.
The turbine wheel 29 is a loose push-on seat on the pivot
bearing of the pivot shaft 31. This enables it to be
removed for cleaning purposes, for example. Rib members
29.4 are integrally formed on the upper side of the rotor
29.2 in an axially protruding manner. These rib members
29.4 prevent the turbine wheel 29 from being slipped onto
the pivot shaft 31 in the improper position, their pro-
trusions making it impossible for the emulsifying cage
30, which will be described in more detail in the
following, to be seated down in locking engagement.
On the other hand, the rib members 29.4 contribute
to a still more intensive turbulence of the liquid to be
treated and provide for good rinsing of the centrally
disposed components, for example, the inside of the
nozzle body core 24, during cleaning.
FIGS. 8 and 9 of the drawings show an emulsifying
cage 30. FIG. 9 is a view of the emulsifying cage, as
seen looking from the direction A of FIG. 8.
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In assembled condition, the emulsifying cage 30
embraces the turbine wheel 29 and the periphery of the
nozzle body 20 at its free end. Knobs 37 are formed on
the side walls 36 of the approximately cup-shaped emulsi-
fying cage 30 at its open upper end, enabling the
emulsifying cage 30 to be located in positive engagement
with the lower end of the nozzle body 20. The knobs 37
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are in cooperative relation with radial grooves 38 on the
periphery of the nozzle body 20, such that after passing
the knobs 37 through the grooves 38, the emulsifying cage
is located on the radially protruding rim 39 by a
turning motion relative to the nozzle body 20.
The underside 40 of the emulsifying cage 30 is
largely open for free passage of the emulsion to be
treated; only three web members 41 extending radially
from the pivot 42 to the side walls 36 are provided. The
side walls 36 include intake ports 33 pointing radially
outwardly. Their position is such that they are at least
in part above the turbine wheel 29 in the assembled con-
dition of the emulsifying cage 30.
The capability also exists to provide additional
ribs, webs and grooves on the inner side of the
emulsifying cage 30, such as on the side walls 36. Such
additions may produce still more intensive turbulence and
thus thorough blending.
FIG. 11 shows the device in assembled, operative
condition. In thls Figure, too, the underside of the
nozzle body 20 or the nozzle body core 24 provides an end
shield 32 which combines with the upper side of the tur-
bine wheel 29 to form an emulsifying chamber EK. The
steam discharge nozzles 28 are so arranged that the steam
exhausted from them at high velocity impinges directly on
the upper side of the turbine vanes 29.3, thereby causlng
rotation of the turbine wheel. If a recipient containing
a liquid to be frothed is placed against the device, the
liquid to be treated enters between the web members 41 up
into the emulsifying cage 30 where it is mechanically
treated by the turbine wheel 29. At the same time, the
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turbine wheel 29 induces air laterally through the ports
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33, so that superheated steam, air and swirled-up liquid
are intimately mixed already in the emulsifying chamber
EK. The resulting emulsion is then pushed down by the
turbine vanes 29.3 and is further treated mechanically as
this occurs.
The only thing the user should remember is not to
immerse the device too deeply in the liquid to be
treated. The liquid level should be at the level of the
end shield 32, approximately. On the other hand, a
momentary deeper immersion will have no detrimental
effect, the turbine wheel rotating at high velocity
causing a sufficient amount of additional air to be
induced.
The emulsifying cage 30 has a supplementary func-
tion: The side walls 36 on the cage 30 provide a splash
guard. When the induction effect of the turbine wheel 29
through the ports 33 is sufficient, spattering of liquid
to the sides is reliably prevented.
The device of the invention is practically self-
cleaning, because a rotating turbine wheel causes the
particles of treated liquid to be virtually centrifuged
away. Thus, easy cleaning may be accomplished using
simple tap water in combination with the steam exhausted
from the steam discharge nozzles.
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204g631
05566
_ 12 -
1 push-on head
nozzle body
11 steam passage
12 steam discharge nozzles
13 steam ducts
14.1 pivot bearing
14.2 rotor
14.3 turbine vanes
end shield
16 bolt
17 pivot shaft for 14
18 thread of 16
19 internal thread in 10
nozzle body
21 push-on head, integrally forme~
22 threaded/clamp-type locking means
23 nozzle body bell
24 nozzIe body core
conical outer wall of 24
26 conical inner wall of 23
27 steam ducts
28 steam discharge nozzles
29 turbine wheel
emulsifying cage
29.1 pivot bearing
29.2 rotor
29~3 turbine vanes
29.4 rib members
31 pivot shaft for 29
32 end shield
33 intake ports
34: abutment ring of 24
bore:
36 side~walls of 30
37: knobs
38 grooves
39 radial rim of 20:
underside of 30
41 web:members
42 piVQt
R steam pipe
RE free end of steam pipe
EK emulsifying chamber
M central axis:
D discharge direction of steam/emulsion
,
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