EP2590540A1

EP2590540A1 - Infusion unit

Info

Publication number: EP2590540A1
Application number: EP11754727.3A
Authority: EP
Inventors: Mauro Gambaudo
Original assignee: SGL Italia SRL
Current assignee: SGL Italia SRL
Priority date: 2010-07-08
Filing date: 2011-07-08
Publication date: 2013-05-15
Also published as: IT1400886B1; ITTO20100591A1; WO2012004660A1; WO2012004660A8

Abstract

An infusion unit, wherein a pump (8), for feeding water to an infusion chamber (24) and to a hydraulic cylinder (25) for closing the infusion chamber (24), is equipped with an auto-priming, fast-discharge valve assembly (34), wherein an inner chamber (43) houses a sliding shutter (54) dividing the inner chamber (43) into a first half-chamber (59) communicating with the delivery of the pump (8) via a first port (33), and a second half-chamber (58) communicating with the outside via a second port (35), and with the hydraulic cylinder (25) via a third port (37); the shutter (54) being mounted inside the chamber (43) to move between a normal first position opening the second port (35), and a second position closing the second port (35), and being designed to permit fluid flow from the first port (33) to the second and third port (35, 37) in the first position, and to permit fluid flow from the third port (37) to the second port (35) in the second position.

Description

INFUSION UNIT

TECHNICAL FIELD

The present invention relates to a beverage infusion unit.

More specifically, the present invention relates to an infusion unit comprising a number of component parts, in turn comprising an infusion chamber; a hydraulic cylinder for opening-closing the infusion chamber; a water tank; a pump for feeding water from the tank to the infusion chamber and the hydraulic cylinder; and a hydraulic circuit connecting the component parts and comprising control and discharge valve means.

BACKGROUND ART

An infusion unit of this type is described, for example, in WO 2010/043952 in the name of the present Applicant .

Though the infusion unit according to the present invention is designed to make numerous different beverages, the following description refers, purely by way of example, to an infusion unit for making a coffee beverage from a measure of ground coffee housed or not inside a container.

One of the major drawbacks of infusion units of the above type lies in the pump, normally an electromagnetic pump, also drawing in a certain amount of air when pumping water from the tank, thus resulting in improper priming of the pump, so the percolating chamber takes longer to close, and the beverage normally takes longer to make .

Another major drawback is that, to discharge the hydraulic cylinder quickly following percolation, infusion units of this type need special valve elements which are not only expensive but also seriously complicate the internal design of the unit.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide an infusion unit of the above type, designed to eliminate the above drawbacks.

According to the present invention, there is provided an infusion unit as claimed in Claim 1 and preferably in any one of the following Claims.

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 of a preferred embodiment of the infusion unit according to the present invention;

Figures 2 and 3 show axial sections of a detail in Figure 1 in two different operating configurations.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole an infusion unit for an espresso coffee machine.

Infusion unit 1 comprises a number of component parts, in turn comprising an infusion water tank 2 with a bottom outlet 3, which communicates with the inside of tank 2 via a known softening device 4 housed inside tank 2.

Outlet 3 is connected, by a line 5 extending through a filter 6 and a known volume meter 7, to the inlet of a preferably electromagnetic pump 8, the outlet of which is connected by a line 9 to the inlet 10 of a three-way solenoid valve 11 having two outlets 12 and 13, and which is designed to assume an open position connecting inlet 10 to outlet 13, and a closed position connecting outlets 12 and 13 to each other and closing inlet 10. Outlet 12 is connected by a drain line 14 to a drain vessel 15; and outlet 13 is connected to an intermediate point along a feed line 16 connected at one end to the inlet 17 of a known boiler 18, the outlet 19 of which is connected to an intermediate point along a line 20 extending in known manner between a steam dispenser 21 controlled by a tap 22, and a calibrated inlet valve 23 of an infusion chamber 24.

Infusion chamber 24 is designed to house a measure of ground coffee, and is controlled by the piston of a hydraulic cylinder 25 having an inlet-discharge port 26.

At the opposite end to that connected to inlet 17 of boiler 18, feed line 16 is connected to the inlet 27 of a three-way solenoid valve 28 having two outlets 29 and 30, and which is designed to assume an open position connecting inlet 27 to outlet 30, and a closed position connecting outlets 29 and 30 to each other and closing inlet 27 . Outlet 29 is a discharge outlet connected by a line 31 to tank 2 ; and outlet 30 is connected by a line 32 to an inlet end port 33 of a fast-discharge, autopriming valve assembly 34 (described in detail below) , which has a discharge end port 35 connected by a line 36 and a T fitting to an intermediate point along line 31 , and an inlet-outlet port 37 connected by a line 38 to the inlet-discharge port 26 of hydraulic cylinder 25 .

As shown more clearly in Figures 2 and 3 , valve assembly 34 comprises a cup-shaped cylindrical body 39 having a longitudinal axis 40 and comprising a tubular lateral wall 41 coaxial with axis 40 , and an end wall 42 crosswise to axis 40 . Lateral wall 41 and end wall 42 define a cylindrical chamber 43 coaxial with axis 40 , and which, at the opposite end to that closed by end wall 42 , has an opening 44 engaged by a plug 45 coaxial with axis 40 and locked axially to cylindrical body 39 by a bayonet joint 46 .

Plug 45 comprises an inner portion 47 extending inside part of chamber 43 and engaging the inner lateral surface of lateral wall 41 in fluidtight manner; and an outer portion extending outside cylindrical body 39 and defining a connection 48 for line 36 . Plug 45 has an axial through hole 49 , the end of which, at the free end of connection 48 , defines discharge end port 35 .

At a free end portion of inner portion 47 , hole 49 has a wider portion 50 , which communicates with the inside of the chamber through an end opening 51 formed through a free axial end surface of inner portion 47 crosswise to axis 40 . This end surface defines an annular seat 52 for a cylindrical centre portion 53 of a shutter 54 made of elastically deformable, preferably elastomeric, material, and which, in addition to centre portion 53 , comprises an axial appendix 55 , which engages wider portion 50 and serves as a locator for a calibrated helical spring 56 , or other similar elastic element (not shown) , compressed, inside wider portion 50 , between centre portion 53 and an annular end shoulder of wider portion 50 ; and a concave, conical, peripheral annular lip 57 positioned with its concavity facing plug 45 , and which cooperates elastically with the inner lateral surface of lateral wall 41 to divide chamber 43 into two half-chambers 58 , 59 coaxial with axis 40 and varying in volume in complementary manner. Half-chamber 58 houses inner portion 47 of plug 45 ; and half-chamber 59 houses a stop 60 extending axially inside chamber 43 towards plug 45 from end wall 42 to limit the travel of shutter 54 to a normal open position (Figure 2 ) opening discharge end port 35 and in which centre portion 53 of shutter 54 is pushed by spring 56 onto stop 60 , and a closed position (Figure 3 ) closing discharge end port 35 and in which centre portion 53 of shutter 54 is positioned, in opposition to spring 56 , contacting seat 52 .

Valve assembly 34 has two radial connections 61 , 62 for attaching respective lines 38, 32, and which have respective axial holes communicating with respective half-chambers 58, 59 and defining inlet-outlet port 37 and inlet end port 35 respectively.

When pump 8 is turned on, a stream of cold water is drawn from tank 2 through softening device 4 and along line 5, and normally contains air which temporarily affects operation of pump 8 by preventing it from priming properly.

The water-air stream flows along line 9 and through solenoid valve 11 - set connecting inlet 10 to outlet 13 - to line 16, along which part of the flow containing substantially all the air flows up to solenoid valve 28, while the rest is fed to boiler 18 and line 20.

Line 20 is closed at one end by tap 22, and at the other by inlet valve 23 of infusion chamber 24, which, at this point, is open and already loaded with a measure of ground coffee (not shown) .

The part of the water-air stream directed to solenoid valve 28 finds this set connecting inlet 27 to outlet 30, and so flows to inlet end port 33 of valve assembly 34, which is set to the normal closed position shown in Figure 2.

The water-air stream flows through inlet end port 33 into half-chamber 59, and is stopped by shutter 54. Given the presence of air in the flow to half-chamber 59, and the compressibility of the air itself, the initial increase in pressure inside half-chamber 59 is too low to overcome the action of spring 56 , but is high enough to allow the air to flex annular lip 57 slightly, flow into half-chamber 58 , reach hole 49 and discharge end port 35 , and so flow out along line 36 .

Valve assembly 34 thus acts as a fast-acting bleed and automatic priming device enabling pump 8 , in the space of a few seconds, to supply half-chamber 59 with cold water containing no air. The pressure inside half- chamber 59 thus increases rapidly to move shutter 54 , in opposition to spring 56 , into the closed position closing hole 49 and discharge end port 35 , so the cold water can flow through port 37 of valve assembly 34 and along line 38 to hydraulic cylinder 25 to close infusion chamber 24 .

During this operation, the delivery from pump 8 is compensated by expansion of hydraulic cylinder 25 , so the pressure along lines 9 , 16 , 32 and 38 remains substantially constant. However, when the piston of hydraulic cylinder 25 eventually closes infusion chamber 24 and stops, the pressure along lines 9 , 16 , 32 and 38 increases rapidly to a point at which hot water flows out through inlet valve 23 to infuse the ground coffee.

This continues until pump 8 is stopped by a signal from volume meter 7 , solenoid valves 11 and 28 close simultaneously, and valve assembly 34 returns to its normal open position.

More specifically, outlet 13 of solenoid valve 11 is connected to drain outlet 12 to drain the hot water in lines 20 and 16 along drain line 14 into drain vessel 15; and outlet 30 of solenoid valve 28 is connected to discharge outlet 29 to rapidly discharge the cold water in half-chamber 59 and line 32 along discharge line 31 into tank 2.

In valve assembly 34, line 38 is connected to tank 2 by half-chamber 58 and lines 36 and 31, to rapidly withdraw the piston of hydraulic cylinder 25 and open infusion chamber 24. In other words, at this stage, valve assembly 34 provides for rapidly discharging hydraulic cylinder 25.

One valve assembly 34 therefore provides for both bleeding pump 8 and rapidly discharging hydraulic cylinder 25.

If infusion unit 1 is only used to produce steam, the process is the same as described above, except that solenoid valve 28 is kept closed (outlet 30 is connected to discharge outlet 29, and inlet 27 is closed) to cut off cold water feed to hydraulic cylinder 25. When only producing steam, the fall in pressure along line 20 prevents inlet valve 23 from opening, and therefore hot water from being fed to infusion chamber 24.

Solenoid valve 28 therefore mainly provides for preventing operation of hydraulic cylinder 25 when only producing steam. But, if this minor drawback is considered negligible, solenoid valve 28 may obviously be eliminated, and outlet 13 of solenoid valve 11 connected directly to inlet end port 33 of valve assembly 34.

Claims

1) An infusion unit comprising a number of component parts, in turn comprising an infusion chamber (24) ; a hydraulic cylinder (25) for opening-closing the infusion chamber (24); a water tank (2); a pump (8) for feeding water from the tank (2) to the infusion chamber

(24) and hydraulic cylinder (25); and a hydraulic circuit connecting the component parts and comprising control, bleed, and fast-discharge valve means; the infusion unit being characterized in that said valve means comprise a valve assembly (34) for automatically priming the pump (8) and rapidly discharging the hydraulic cylinder; the valve assembly (34) comprising a chamber (43), a shutter (54) mounted inside the chamber (43) to divide the chamber (43) into a first and second half-chamber (59, 58), a first port (33) connecting the first half-chamber (59) to the delivery of the pump (8), a second port (35) connecting the second half-chamber (58) to the outside, and a third port (37) connecting the second half-chamber (58) to the hydraulic cylinder

(25) ; the shutter (54) being mounted inside the chamber (43) to move between a normal first position opening the second port (35) , and a second position closing the second port (35) , and being designed to permit fluid flow from the first port (33) to the second and third port (35, 37) in the first position, and to permit fluid flow from the third port (37) to the second port (35) in the second position.

2) An infusion unit as claimed in Claim 1, wherein the shutter (54) comprises an elastically deformable annular sealing lip (57) cooperating with a surface of the chamber (43) to divide the chamber (43) into said first and second half-chamber (59, 58); the annular lip (57) being conical and concave, with its concavity facing the second half-chamber (58) ; and calibrated elastic means (56) being provided to keep the shutter (54) normally in the first position.

3) An infusion unit as claimed in Claim 1 or 2 , wherein the hydraulic cylinder (25) and the infusion chamber (24) are parallel; the hydraulic circuit comprising a first portion (32, 38) connecting the pump (8) to the hydraulic cylinder (25) , and a second portion (16, 20) parallel to and communicating with the first portion (32, 38), and connecting the pump (8) to the infusion chamber (24) ; the valve assembly (34) being fitted to said first portion (32, 38); the first port (33) communicating with the delivery of the pump (8); the second port (35) being a bleed and/or discharge port; and the third port (37) communicating with the hydraulic cylinder (25) .

4) An infusion unit as claimed in one of the foregoing Claims, wherein the chamber (43) is a cylindrical chamber with an axis (40) ; the shutter (54) is movable axially along the chamber (43); and the elastic means (56) are mounted to act axially on the shutter (54) .

5) An infusion unit as claimed in Claim 4, wherein the first and third port (33, 37) are radial with respect to said axis (40) .

6) An infusion unit as claimed in Claim 4 or 5, wherein the second port (35) is axial with respect to said axis (40) .

7) An infusion unit as claimed in one of the foregoing Claims, wherein the valve assembly (34) comprises a cup-shaped tubular body (39) , which defines said chamber (43) and has a longitudinal axis (40) , a transverse wall (42) closing one end, and an axial opening (44) at the other end; and a plug (45) closing said axial opening (44) ; the second port (35) being an axial port formed through the plug (45) ; the first and third port (33, 37) being radial ports formed through the tubular body (39) ; and the shutter (54) being housed in the tubular body (39) and movable axially along a portion of the tubular body (39) extending between the first and third port (33, 37) .

8) An infusion unit as claimed in Claim 7, wherein the plug (45) extends axially inside the tubular body (39) to define a first end of said portion of the tubular body (39) , and a seat (52) for supporting the shutter (54) in the second position; stop means (60) being housed inside the chamber (43) to define a second end of said portion of the tubular body (39) , and a support for the shutter (54) in the first position. 9) An infusion unit as claimed in Claim 7 or 8, wherein said elastic means (56) comprise a helical spring (56) coaxial with said longitudinal axis (40) and compressed between the shutter (54) and the plug (45) .