WO2009071247A1

WO2009071247A1 - Device for the production of milk foam or the like

Info

Publication number: WO2009071247A1
Application number: PCT/EP2008/010114
Authority: WO
Inventors: Bruno Bardazzi; Alessandro Doria
Original assignee: Espressocap S.R.L.
Priority date: 2007-12-05
Filing date: 2008-11-28
Publication date: 2009-06-11
Also published as: ITGE20070119A1

Abstract

Device for producing milk froth or the like, comprising a member (101) connectable to supply means (11) for supplying pressurized water steam from a boiler at one end thereof, and provided with discharge means (211) at the other end thereof, said member (101) being in fluid communication with a suction duct (301, 2) for sucking milk or other liquid intended to froth production, through an opening (121) formed between said two ends, said suction duct being provided with air-suction means (401, 311 ) for sucking air from the external environment.

Description

"DEVICE FOR THE PRODUCTION OF MILK FOAM OR THE LIKE" TEXT OF THE DESCRIPTION

Ths present invention relates to devices for preparing drinks and foods, and particularly it relates to a device for preparing milk froth or the like.

In-house production of whipped milk froth, i.e. the well known

"cappuccino" froth, is a frequently encountered problem. This product - obtainable only in an extemporary manner - is produced in bars by using high-pressurized steam jets and, in any case, by skilled operators; the results normally obtainable by an in-house user are very poor both aesthetically and organoleptically. Many devices of the prior art attempted to obtain a milk froth with a good texture by using joint actions of heating and whipping, but, in this case, the complication was actually due to the combined heating and whipping means, which make the device complex and, above all, difficult to be maintained.

Various devices are known in the art which can use the high- pressurized steam discharge from the boiler of an espresso coffee machine in order to make an aesthetically and organoleptically desirable milk froth. However, they are highly complex devices both in terms of construction and utilisation. Such devices take advantage of the steam jet both for sucking the milk intended to make the froth, and for producing the froth by incorporating air from the environment, optionally by making additional use of mechanical stirring means.

Therefore, the aim of the present invention is to provide a device for producing milk froth or the like, which can be manufactured in a simple and inexpensive way using the smallest possible number of parts and materials which are the easiest to be processed, while being able to be used virtually with any pressurized steam source, and primarily with espresso coffee machines. Therefore, the object of the present invention is a device for producing milk froth or the like, comprising a member connectable to supply means for supplying pressurized water steam from a boiler at one end thereof, and provided with discharge means at the other end thereof, said member being in fluid communication with a suction duct for sucking milk or other liquid intended to froth production, through an opening arranged between said two ends, said suction duct being provided with air-suction means for sucking air from the external environment.

In a preferred embodiment, said device comprises a tubular sleeve intended to be coupled to the supply means for pressurized water steam from a boiler at one end thereof, and provided with a supply nozzle at the opposite end thereof, said sleeve being provided with a radial channel in communication with the suction duct for milk or the like, said duct being provided with a radial opening for sucking air from the external environment near said communication channel with said sleeve. Preferably, the sleeve, the suction duct and the air-suction means are formed as a unitary block which is integrally made of a thermoplastic material.

The air-suction means are formed as a duct which is open at one end thereof and in radial communication with the milk-suction duct, said duct having removable closing means provided with suitable air-drawing passages. From one hand, such closing means can protect the fluid being processed against external agents, and from the other hand, the ability of removing such closing means allows to maintain the communication opening between the two ducts in a clean condition. Typically, the communication openings between the sleeve and the milk-suction duct, and between the milk-suction duct and the air-suction duct, respectively, are sized in order to maximize the turbulence effects which ensure the production of froth from the so-sucked liquid.

Other advantages and features of the device according to the present invention will be apparent from the following description of an embodiment thereof, which is provided by way of illustration, and not by way of limitation, with reference to the accompanying drawings, wherein:

Figure 1 is a side elevation view of the device according to the present invention, as applied to a machine for making espresso coffee; and Figure 2 is a longitudinal sectional view of a preferred embodiment of the device according to the present invention.

Figure 1 illustrates an embodiment of the device according to the present invention; reference numeral 10 denotes an espresso coffee machine internally provided with a water tank 13 connected to a boiler 14 which, in turn, is connected to supply means 11 for supplying pressurized water steam. The device according to the invention, as denoted by 1 in the figure, is coupled to said supply means and carries a spout 12 which is normally connected to said means. A tube 2 is connected to the device 1 for sucking milk 21 from a container 20; the device 1 pours the resulting froth into a cup 30 placed below it through the spout 12.

Figure 2 is a sectional view of the device according to the present invention; it comprises a sleeve 101 provided with an inner cylindrical cavity 111 whose open end allows to couple the supply means 11 of pressurized steam to an end 15. Said end 15 is provided with sealing means 17 and an axial channel 16. A duct 211 is axially formed on the bottom of the cavity 111 of the sleeve 101 , said duct ending in an expandable cavity 231 formed in a tail member 201 at an end of the sleeve 101 which is opposite to the end connected to the steam supply means 11. Said tail member 201 is provided with sealing means 221 to sealingly couple it to the spout 12. A channel 121 ends in the cavity 111 of the sleeve 101 , said channel being radially formed with respect to said cavity 111 and connecting it to the inner cavity of a duct 301 whose axis is perpendicular to said sleeve 101. The free end of the duct 301 is connected to the tube 2 for sucking milk from the container, as illustrated in Figure 1 and previously described. A radial opening 311 is formed near the end of the duct 301 which is faced to the cavity 111 of the sleeve 101 , which radial opening makes said duct in communication with a chamber 401 having a plug 501 placed therein. Said plug has a radial flange 511 with grooves 521 to allow external air to access said chamber 401 ; furthermore, a notch 531 is formed in the body of the plug, whereby sealing means 541 allow to fixedly position said plug while allowing air to pass through.

The operation of the device according to the present invention will become apparent from the following. The device is coupled to the pressurized steam-supply means as normally provided in a conventional espresso coffee machine, which can be either manual, semi-automatic or automatic, operating either in an extemporary manner or with pre-packaged doses. The coupling can be carried out by removing the supply spout 12, which is then remounted onto the same device according to the method shown in Figure 2. By supplying steam through the supply means 11 , the steam flow passing through the cavity 111 of the sleeve 101 sucks the fluid in the duct 301, that is the milk coming from the container 20 as shown in Figure 1 , by virtue of an ejection effect, i.e. the well known Venturi effect. In the same time, before encountering the steam in the cavity 111 , the sucked milk blends with air from the chamber 401 , which air is also subjected to an ejection effect in a completely analogous manner.

In this way, a fine dispersion of air bubbles is introduced into the mass of liquid milk; since this dispersion is processed by the hot steam jet with which it blends in the cavity 111 , it can form a milk froth which is then supplied to the cup 30 through the spout 12. Advantageously, the duct 211 connecting the cavity 111 to the spout 12 ends in an expandable cavity 231 to increase the flow turbulence of the fluids which have just blended, so as to improve the intimate mixing of the liquid fluids, in this case milk, with the gaseous fluids, i.e. water steam and air.

Of course, the relative sizes of the different ducts in communication with each other can be properly studied in order to improve the results of the so-generated ejection effect; the size ratios in the figure have not been exactly illustrated for the sake of graphical presentation. It can be considered that the ratio between the cross-section of the communication opening of the air-suction chamber 401 and the cross-section of the milk-suction duct 301 can be from 1 :4 to 1 :8, while the ratio between the cross-section of the channel 121 and the cross-section of the cavity 111 of the sleeve 101 can be from 1 :10 to 1 :20.

As already mentioned above, the plug 501 inserted in the cavity of the chamber 401 serves only to prevent extraneous particles from entering the sucked flow; in this way, when the plug 501 has been removed, the chamber 401 , is easily accessed and maintained.

The whole device 1 can be easily formed integrally by moulding of a thermoplastic material, with the only criterion being to select a material which is resistant to temperatures greater than 100⁰C, and preferably greater than 150⁰C.

By making the necessary adjustments, that is after the sleeve 101 has been conveniently sized, it is possible to produce devices of the type described according the present invention virtually for any espresso coffee machine which is currently available on the market.

Claims

1. Device for producing milk froth or the like, comprising a member (101) connectable to supply means (11) for supplying pressurized water steam from a boiler at one end thereof, and provided with discharge means (211) at the other opposite end thereof, said member (101) being in fluid communication with a suction duct (301 , 2) for sucking milk or other liquid intended to froth production, through an opening (121) formed between said two ends, said suction duct being provided with air-suction means (401 , 311) for sucking air from the external environment.

2. Device according to Claim 1 , comprising a tubular sleeve (101) intended to be coupled to said supply means (11) for pressurized water steam from a boiler at one end thereof, and provided with a supply nozzle (201) at the opposite end thereof, an internal cavity (111) of said sleeve (101) being in communication with the suction duct (301) for milk or the like through a suitable radial channel (121), said duct being provided with a radial opening (311) for sucking air from the external environment near said communication channel (121) with said sleeve.

3. Device according to Claim 1 or 2, wherein said air-suction means comprise a chamber (401), said chamber being open at one end thereof and communicating with the milk-suction duct (301) through a port (311) formed radially thereof.

4. Device according to Claim 3, wherein said chamber (401) is provided with removable closing means (501) formed to allow air to be drawn.

5. Device according to any one of the preceding Claims 2 to 4, wherein the ratio between the cross-section of the communication opening (311) of the air-suction chamber (401) and the cross-section of the milk-suction duct (301) can be from 1 :4 to 1 :8.

6. Device according to any one of the preceding Claims 2 to 5, wherein the ratio between the cross-section of the channel (121) and the cross-section of the cavity (111) of the sleeve (101) can be from 1 :10 to 1 :20.

7. Device according to any one of the preceding Claims 2 to 6, wherein the sleeve (101), the milk-suction duct (301) and the air-suction means (401) are formed as a unitary block which is integrally made of a thermoplastic material.