Method of making a beverage from powdered material in a sealed capsule

In a process employing a coffee machine, a sealed capsule is fed with a certain amount of axial clearance into a cup aligned along a horizontal axis with a pressurized-hot-water sprinkler, and is moved towards the sprinkler to press an annular flange of the sealed capsule in fluidtight manner against the sprinkler, to pierce a front sealing wall of the sealed capsule by means of a first piercing device, to feed pressurized hot water through the sealing wall to expand the sealed capsule axially and eliminate the axial clearance, and to bring an end wall of the sealed capsule into fluidtight contact with a second piercing device, and pierce the end wall against the second piercing device, so that coffee flows out through the second piercing device.

TECHNICAL FIELD

The present invention relates to a method of making a beverage from powdered material in a sealed capsule.

Though the method of the present invention is suitable for percolating any type of beverage made by feeding pressurized hot water through powdered material in a sealed capsule, specific reference is made in the following description, purely by way of example, to a method for making a coffee beverage from a measure of ground coffee in a cup-shaped sealed capsule closed at one end by an end wall, and at the other end by a sealing wall connected integrally to an outer annular flange extending radially outwards from an end of a lateral wall of the sealed capsule.

BACKGROUND ART

Use of sealed capsules of the above type in a percolating machines is described, for example, in EP-1 219 217 and EP-1 295 554 of the same Applicant and in U.S. Pat. No. 5,398,596.

In percolating machines employing non-sealed capsules, percolation is normally performed by sealing a capsule axially and in fluidtight manner between a sprinkler of a pressurized-hot-water dispensing assembly and a piston movable to and from the sprinkler and having an outflow conduit for the percolated beverage.

The same method cannot be used when employing sealed capsules of the type described above, which are made of deformable material incapable of withstanding the axial compression to which non-sealed capsules are normally subjected to ensure fluidtight engagement of their end walls with the sprinkler at one end and with the piston at the other.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a percolating method enabling use of sealed capsules without affecting their structural stability.

According to the present invention, there is provided a method of making a beverage from powdered material in a sealed capsule, as claimed in claim1and, preferably, in any one of the following Claims depending directly or indirectly on claim1.

BEST MODE FOR CARRYING OUT THE INVENTION

Number1inFIG. 1indicates as a whole a percolating machine for making a coffee beverage from a measure of ground coffee in a sealed capsule2, which comprises a cup-shaped body made of thermoplastic material and having a truncated-cone-shaped lateral wall3having an outer annular flange4at its major base, and closed at its minor base by an inwardly convex end wall5. At the major base of lateral wall3, the cup-shaped body is closed in fluidtight manner by a sealing wall6normally made of metal foil, and the periphery of which is integral with the outer surface of annular flange4.

Machine1comprises a frame7, in turn comprising two substantially rectangular plates8located symmetrically on opposite sides of and parallel to a horizontal axis9, and connected to each other at one longitudinal end by a transverse wall10, and at the opposite longitudinal end by a transverse wall10afitted through with a pressurized-hot-water dispensing assembly11coaxial with axis9.

As shown inFIGS. 2 and 3, dispensing assembly11comprises a known boiler12located outwards of transverse wall10aand for receiving pressurized water from a known pump (not shown); and a sprinkler13connected to boiler12through transverse wall10ato receive pressurized hot water from boiler12via a one-way valve14calibrated to open when the pressure upstream from one-way valve14reaches a given value.

Dispensing assembly11also comprises a tubular body15, which is interposed between boiler12and sprinkler13, has, at the end facing boiler12, an annular flange16connected integrally to transverse wall10a, and has a central through hole coaxial with axis9and housing an end portion of a truncated-cone-shaped sleeve17extending through a hole18in transverse wall10aand connected integrally to boiler12.

As shown inFIG. 2, at the end facing boiler12, sleeve17communicates with the outlet of a feed conduit19fitted through boiler12and defining, at the end communicating with sleeve17, a spherical seat for supporting a shutter20of valve14.

Tubular body15supports a piercing device21comprising a circular plate22, which is coaxial with axis9, is fitted in fluidtight manner to the end of tubular body15via the interposition of two annular seals, one surrounding the periphery of plate22, and is connected removably to tubular body15by a bayonet joint. Plate22has a central through hole23coaxial with axis9, and, on the side facing boiler12, comprises a tubular appendix fitted in fluidtight manner, via the interposition of an annular seal, inside the end of sleeve17opposite the end engaged by feed conduit19, so as to define a seat for a spring24by which shutter20is pushed against its spherical seat.

In addition to plate22, piercing device21also comprises a number of needles25integral with one another and with plate22, and extending, parallel to axis9, from plate22towards transverse wall10.

Sprinkler13is substantially cup-shaped, is coaxial with axis9, with its concavity facing boiler12, and comprises a cylindrical lateral wall26fitted in axially-sliding manner to a cylindrical outer surface of tubular body15; and an end wall27parallel to and facing plate22, and having a number of holes28, each coaxial with a respective needle25.

As shown inFIGS. 2 and 3, sprinkler13is mounted to move, in opposition to a number of springs29compressed between flange16of tubular body15and sprinkler13itself, between an extracted rest position (FIG. 2), in which end wall27is kept detached from plate22by a known stop device (not shown), and needles25are housed inside sprinkler13, and a withdrawn work position (FIG. 3), in which end wall27contacts plate22, and needles25project from respective holes28.

In addition to dispensing assembly11, machine1also comprises a hydraulic cylinder29, which is housed between plates8of frame7, coaxially with axis9and facing sprinkler13, and in turn comprises a fixed tubular body30coaxial with axis9, and a piston31coaxial with axis9and mounted to slide axially along tubular body30and through a ring32integral with tubular body30and closing the end of tubular body30facing dispensing assembly11.

As shown inFIGS. 2 and 3and in more detail inFIGS. 6 and 7, an intermediate portion of piston31is defined by a finned section, two diametrically opposite radial fins33of which engage, in use, respective grooves34formed in an inner surface of ring32to guide piston31axially along tubular body30, and to lock piston31angularly about axis9with respect to tubular body30.

Piston31comprises an annular end flange35, which faces an end wall36of tubular body30, extends radially from piston31up to tubular body30, and defines, between piston31and end wall36, a variable-volume chamber37, which is closed in fluidtight manner by an annular seal38fitted to the end of piston31, and communicates with the outside via a pressurized-hot-water feed conduit39. A return spring40is mounted between ring32and flange35, and is coiled, coaxially with axis9, about the intermediate portion of piston31.

As shown inFIGS. 2 and 3, at the end facing sprinkler13, piston31is fitted with a truncated-cone-shaped tubular appendix flaring towards sprinkler13, coaxial with axis9, and defining the lateral wall41of a cup42for housing a capsule2, and which is movable, by piston31and in a direction parallel to axis9, between a withdrawn position (FIG. 2) detached from sprinkler13, and a forward infusion position (FIG. 3), in which, in use, a free edge43of cup42presses flange4, of a capsule2inside cup42, in fluidtight manner against sprinkler13.

Cup42houses a piercing device44comprising a plate45resting on the bottom of cup42and having a number of needles46, which extend parallel to axis9, are integral with one another, and, in use, pierce end wall5of capsule2, so that the percolated coffee flows out from capsule2and through a number of holes, formed through needles46and plate45, into an outflow conduit47.

Plate45is locked to the bottom of cup42by an elastic retaining ring48comprising, as shown clearly inFIG. 7, a number of outer appendixes49, which engage respective through slots50formed at the base of lateral wall41of cup42. One of slots50is left free to tighten elastic ring48from the outside, and to remove elastic ring48and plate45.

As shown inFIGS. 1 and 2, machine1also comprises a loading device51located between sprinkler13and cup42, and which receives a capsule2downwards, and holds it in position coaxial with axis9, with sealing wall6substantially contacting end wall27of sprinkler13.

Loading device51comprises an inlet conduit52integral with frame7and sized to permit insertion of a capsule2, positioned with sealing wall6facing sprinkler13, in a substantially vertical loading direction perpendicular to axis9. As shown inFIGS. 1 and 5, inlet conduit52is bounded, on the side facing cup42, by two plates53crosswise to axis9and defining a gap54, and, on the side facing sprinkler13, by a plate55crosswise to axis9and having a central slot56aligned with gap54. At the top, inlet conduit52has an annular flange57, which cooperates with a lid58hinged to flange57to rotate, about an axis crosswise to axis9, between an open position opening inlet conduit52(as shown by the dash line inFIG. 2), and a closed position closing inlet conduit52. Lid58is fitted, on its inner surface, with an appendix59having a through hole60which, when lid58is in the closed position, is aligned with gap54and slot56, and is engaged transversely (FIG. 3), when cup42is moved into the infusion position, by a pin61fitted rigidly to the top of piston31and which locks lid58in the closed position.

Loading device51also comprises a gripping device62, in turn comprising two jaws63(FIG. 5) extending downwards from flange57, located symmetrically on opposite sides of axis9, and each comprising a top portion64, and a curved bottom portion65with its concavity facing the other bottom portion65. Each top portion64is hinged at its top end to a respective fixed pin66, parallel to axis9, to oscillate, in opposition to a spring (not shown), between a closed position and an open position closing and opening gripping device62respectively. In the closed position, top portions64define a funnel-shaped seat67communicating upwards with the inside of inlet52, and downwards with a substantially cylindrical seat68coaxial with axis9and defined by bottom portions65. Seat68is open on the sides facing sprinkler13and cup42, and retains a capsule2positioned with its sealing wall6substantially tangent to end wall27of sprinkler13.

When machine1is turned on by the user, pressurized hot water is pumped along feed conduit39into chamber37, thus moving cup42from the withdrawn to the infusion position. During this movement, edge43of cup42engages the ends of bottom portions65facing cup42, thus parting jaws63to ease capsule2into cup42.

On receiving capsule2, cup42continues along axis9, thus moving sprinkler13from the extracted rest position to the withdrawn work position, so that needles25penetrate capsule2through sealing wall6. When cup42eventually reaches the forward infusion position, edge43presses flange4in fluidtight manner against end wall27of sprinkler13.

As shown inFIG. 4, cup42is of such a depth that, when cup42is in the forward infusion position and capsule2is inserted completely inside cup42, a relatively small axial clearance is left between end wall5of capsule2and plate45, and needles46are housed inside the gap between end wall5and plate45.

When valve14opens and pressurized hot water is pumped into capsule2along feed conduit19and through hole23and holes28, the high pressure formed inside capsule2deforms capsule2axially, so that end wall5contacts plate45in fluidtight manner, needles46penetrate capsule2(FIG. 3), and a percolating chamber is formed inside capsule2and communicating with the outside along outflow conduit47.

In connection with the above, it should be pointed out that, during percolation, axial thrust to engage capsule2and sprinkler13in fluidtight manner is applied solely to flange4, and lateral wall3of capsule2is only subjected to axial compression when the pressure inside capsule2is such as to prevent collapse of lateral wall3due to combined bending and compressive stress.

When the user presses a stop button (not shown), pressurized-hot-water supply is cut off, and withdrawal of piston31moves cup42back into the withdrawn position. Along a first portion of this movement, flange4of the used capsule2encounters bottom portions65of jaws63, so that capsule2is gradually extracted from cup42; and, when cup42is released from jaws63, the used capsule2is retained, facing sprinkler13, inside seat68.

When the user inserts a new capsule2inside inlet conduit52to make another coffee, and closes lid58, jaws63part to drop the used capsule2.