PERCOLATING METHOD AND MACHINE FOR MAKING A BEVERAGE FROM ANHYDROUS POWDERED MATERIAL
TECHNICAL FIELD
The present invention relates to a percolating method for making a beverage from anhydrous powdered material .
More specifically, the present invention relates to a percolating method for making a beverage from anhydrous powdered material, wherein pressurized hot water is fed through a fluidtight percolating chamber containing a measure of said material and communicating with the outside via a discharge channel . BACKGROUND ART
In the percolating machine industry, particularly those for producing coffee or barley beverages - to which the following description refers purely by way of example - machines are produced for making a beverage covered with a thick, stable layer of fine froth or so- called "cream" which is extremely popular among consumers .
Forming this creamy layer with air depends on various factors, such as the grain size of the powdered material used; the amount of powdered material used and the extent to which it is compressed inside the percolating chamber; and the pressure of the hot water fed through the percolating chamber.
Correct interaction of all these parameters is necessary, in fact, to produce sufficient hydraulic resistance inside the percolating chamber to oppose flow of the water and form emulsion swirl in the percolated beverage .
In the past, to form "cream" on the beverage, regardless of whether or not the above conditions are achieved, and in particular to increase the amount and quality of the creamy layer, various technical solutions have been employed designed, normally, to mix outside air into the beverage issuing from the percolating chamber. This is done, for example, by increasing the flow speed of the beverage by means of a valve member located along the discharge channel, and directing the resulting jet onto a normally rough surface of an emulsion chamber, where the turbulence formed in the fluid incorporates the surrounding air particles, thus forming froth. Though effective, this solution, in most cases, has the drawback of seriously complicating the design of the percolating device of the machine, thus impairing the
simplicity, sturdiness, and manufacturing cost of the machine itself.
DISCLOSURE OF INVENTION
It is an object of the present invention to provide a percolating method, for making a beverage from anhydrous powered material, designed to produce, in a straightforward, effective, low-cost manner, a beverage covered with a thick, air-emulsified surface layer or so-called "cream" . According to the present invention, there is provided a percolating method for making a beverage from anhydrous powdered material , as claimed in independent Claim 1 and, preferably, in any one of the following Claims depending directly or indirectly on Claim 1. According to the present invention, there is also provided a percolating machine for making a beverage from anhydrous powdered material, as claimed in independent Claim 3 and, preferably, in any one of the following Claims depending directly or indirectly on Claim 3.
BRIEF DESCRIPTION OF THE DRAWINGS
A non-limiting embodiment of the invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a schematic side view of a preferred embodiment of the machine according to the present invention;
Figure 2 shows a larger-scale axial section of an infusion device of the Figure 1 machine;
Figure 3 shows an exploded view of . the Figure 2 infusion device; Figure 4 shows a section along line IV-IV in Figure 2;
Figure 5 shows a larger-scale underside view of a detail in Figure 2;
Figure 6 shows an axial section of a detail in Figure 2.
BEST MODE FOR CARRYING OUT THE INVENTION .
Number 1 in Figure 1 indicates as a whole a percolating machine comprising an outer casing 2; and an infusion device 3 having a substantially vertical axis 4 and located over a flat horizontal surface of outer casing 2 defining a cup supporting surface.
More specifically, as shown in Figures 1, 2 and 4, infusion device 3 comprises a removable percolating cup 5; a pressurized-hot-water sprinkler 6 coaxial with axis 4; and a casing 7 integral with outer casing 2 and comprising a C-shaped bottom portion defining a seat 8 for supporting cup 5 in a percolating position (Figure 1) , in which cup 5 is coaxial with, and connected in fluidtight manner to, sprinkler 6 to form, with sprinkler 6, a percolating chamber 9.
With reference to Figures 2, 3 and 4, cup 5 comprises a body 10, which has an axis coincident with
axis 4 in the percolating position, has a radial handle 11, and is bounded at the top by a flat surface 12 having a central cavity 13 defining a bottom half- chamber of percolating chamber 9, and for partly housing a known wafer 14 containing a measure of ground coffee or barley or other anhydrous material .
Cup 5 also comprises an emulsifying device 16, which is inserted inside a hole 15 coaxial with axis 4 and communicating with cavity 13, and is designed to receive and emulsify the percolated beverage from cavity 13 - as described in detail below - to obtain, at the outlet of infusion device 3, a beverage covered with a thick, stable layer of fine froth.
As shown in Figures 3-6, emulsifying device 16 comprises a cylindrical body 17, in turn comprising a top portion 18 and a bottom portion 19 equal in diameter and separated by an annular flange 20.
Top portion 18 and flange 20 are inserted precisely inside respective portions of hole 15 formed axially along body 10 of cup 5; and bottom portion 19 is housed precisely inside a respective portion of hole 15 formed axially in a beverage spout 21, which is secured to body 10 by screws and with the interposition of an annular seal, and has, on the side facing emulsifying device 16, a tubular appendix extending from spout 21 towards flange 20 to press flange 20 against body 10 and lock emulsifying device 16 axially inside hole 15.
An annular seal 22 is inserted between spout 21 and emulsifying device 16, has an outside diameter equal to the diameter of bottom portion 19, and has an inside diameter equal to the diameter of a hole 23 formed in spout 21, coaxially with axis 4, to connect emulsifying device 16 to the outside and conduct the beverage from emulsifying device 16 out of cup 5.
On the side facing cavity 13, top portion 18 has a truncated-cone-shaped portion projecting axially from hole 15 and having a flat end surface, to which is fitted, by a screw 24, a perforated disk 25 for filtering the beverage extracted from wafer 14, and for separating the centre of cavity 13 from a catch chamber 26 formed at the bottom of cavity 13 and defined by the truncated-cone-shaped portion of emulsifying device 16 and by disk 25.
Catch chamber 26 is surrounded completely by an annular groove coaxial with axis 4 and housing a seal 27. As shown in Figures 2 and 4-6, emulsifying device 16 has two axial grooves formed, diametrically opposite each other with respect to axis 4, in the lateral surface of body 17 and closed laterally by the lateral surface of hole 15 to define, with hole 15, respective channels 28, which define a first portion of a beverage discharge channel formed partly in emulsifying device 16 and partly in spout 21.
Channels 28 come out inside an annular dispensing chamber 29 defined by seal 22 and by an annular groove, which is formed axially in an end surface 30 of bottom portion 19, has an outside diameter smaller than bottom portion 19, and has an inside diameter smaller than the diameter of hole 23.
Dispensing chamber 29 communicates with hole 23 by two narrow channels 31, which define a second portion of the beverage discharge channel, and are defined by respective radial grooves formed in surface 30 and each extending, along an axis 32 perpendicular to axis 4, from a respective inlet facing a respective channel 28, to a respective outlet facing the other outlet and communicating with hole 23, which defines a third and end portion of the discharge channel.
The diameter of the central hole of seal 22 being smaller than the inside diameter of dispensing chamber 29, each channel 31 comprises a tubular first portion, i.e. closed by a corresponding annular portion of seal 22; and a U-shaped second portion open towards hole' 23.
Operation of machine 1 will now be described, as of when cup 5, loaded with a wafer 14, is set to the percolating position (Figures 2 and 4) , in which an outer annular flange of wafer 14 is gripped in fluidtight manner between sprinkler 6 and surface 12 of cup 5 to close percolating chamber 9 containing wafer 14.
When pressurized hot water from sprinkler 6 is fed through wafer 14, the powder in wafer 14 is percolated, and a liquid-air mixture flows out of wafer 14 and filters through disk 25 into catch chamber 26. The remaining pressure forces the mixture from catch chamber 26 into channels 28, then into dispensing chamber 29, and finally into channels 31.
The cross section of channels 31 being much smaller than that of dispensing chamber 29, each mixture flow from dispensing chamber 29 into a respective channel 31 is accelerated sharply as it .flows along the tubular first portion of channel 31, and is converted into a high-speed radial jet directed along axis 32 towards axis 4 .and towards the opposite jet from the other channel 31.
Collision of the two. jets produces considerable turbulence in the resulting mixture flow, so that ■ the liquid particles in the mixture are emulsified with the air particles in the mixture to form a thick froth of beverage mixed with fine air bubbles.
Finally, the emulsified beverage flows out of spout 21 through hole 23 and into a cup, placed beforehand underneath spout 21, to form, inside the cup, a bottom layer of liquid beverage, and a thick, stable top layer of "cream" .
An alternative embodiment (not shown) may have more than two channels 28 and/or channels 31. In the case of
three or more channels 31, the respective jets may- collide at one point common to all of channels 31, or there may be a number of collision points, at each of which at least two channels 31 converge. With reference to the above, it is important to stress the advantage afforded by the method according to the present invention.
By dividing the percolated beverage flow into at least two partial flows, and causing the partial flows to collide to emulsify the liquid particles with air particles "inside" the flow, a thick layer of cream is formed on the coffee with no need to emulsify the flow from the percolating chamber with "outside" air, and therefore with no need for a flow-accelerating system or an emulsion chamber inside the percolating cup, in which to create turbulence.
Moreover, by virtue of the partial flows being formed and colliding inside an emulsifying device located along the discharge channel - of which channels 28 of emulsifying device 16 define a first portion - the resulting percolating cup is straightforward in design, cheap and easy to produce, and highly compact, being not much larger than a normal cup with .no emulsifying device. In this connection, it should be pointed out that, though the example described and shown in the drawings relates to a removable percolating cup with a slide-in
fastening system inside seat 8, in other embodiments not shown, percolating cup 5 may be one of various known types commonly used in percolating machines, e.g. a removable bayonet-connection or non-removable type.
In other embodiments not shown, as opposed to a wafer 14, percolating cup 5 may be designed to house a measure of loose ground coffee, or a known perforated or sealed capsule containing a measure of ground coffee.