Patent Description:
Generally speaking, capsules for infusion products basically comprise a cup-like container, constituting the capsule proper, with or without a filter element inside it and having an inlet opening which is closed by a respective lid. A measured quantity of product - for example, coffee - is filled into the container in substantially known manner, in order to make a beverage by infusion of water through the capsule itself.

Machines for making capsules of this kind comprise a plurality of processing stations, including a station for filling, or dosing, the product into the container and a weighing station for checking that the container is correctly filled.

An example of a machine for making capsules for infusion products is described in patent application <CIT>.

In this machine, the capsules being processed are housed in respective seats made on brackets which feed the capsules along a predetermined path through the processing stations.

More specifically, in the filling station, the capsules - or rather, the containers - are made to pass under the filler, for example of the screw type, from which a certain quantity of product is allowed to drop.

Downstream of the filling station, along the feed path, in the weighing station, the filled capsules are extracted from the respective seat by means of a suitable lifting system in order to release them from the supporting bracket.

The weight of the capsules is then checked by means of loading cells built into the lifting system.

After being weighed, each capsule is lowered back into its seat on the bracket and fed to the subsequent stations.

Generally speaking, prior art capsule making machines comprise a feedback control system configured to control the filling station based on the weight values measured, that is to say, to control the filling of the capsules which follow those previously filled and weighed.

One disadvantage of prior art capsule making machines is due to the fact that a relatively long time is necessary to allow the product to settle inside the capsule after the capsule has been lifted and before it can be weighed. Moreover, the lifting system must be free of the frame or base of the capsule making machine itself so that the vibrations and movements of the machine do not cause inaccurate measurements.

In practice, that means the lifting system and the loading cells constitute a self-contained unit separate from the machine frame and the architecture of the machine in its entirety is thus relatively complex and expensive.

In this context, the main technical purpose of this invention is to overcome the above mentioned disadvantages.

This invention has for an aim to provide a capsule making machine which is constructionally simpler than prior art solutions.

Another aim of the invention is to provide a capsule making machine in which the weighing system can be built into the structure of the machine itself.

The technical purpose and aims specified are substantially achieved by a packaging machine for making capsules according to claim <NUM>.

Further features of the invention and its advantages are more apparent in the non-limiting description below, with reference to a preferred but non-exclusive embodiment of an assembly station, as illustrated in the accompanying drawings, in which:.

With reference to <FIG>, the numeral <NUM> denotes a capsule making machine according to this invention.

The capsule making machine <NUM> is preferably designed to make capsules containing a granular product P for infusion.

A capsule basically comprises a substantially cup-like container <NUM> - with or without one or more filtering elements, not illustrated, inside it - and a lid for closing the container <NUM>.

The container <NUM> has an inlet opening <NUM> through which, as clarified further on in this description, the product P is supplied into the selfsame container <NUM> before the corresponding lid is applied.

The container <NUM> has an outer lip <NUM> surrounding the inlet opening <NUM> and intended, in particular, to be connected to the lid.

More specifically, a measured quantity of product - for example, coffee, to which explicit reference is hereinafter made but without thereby losing in generality - is filled into the container <NUM> in substantially known manner, in order to make a beverage by infusion of water through the capsule itself.

The machine <NUM>, which is described only insofar as necessary for understanding this invention, comprises a feed system <NUM> for feeding the containers <NUM> along a feed path in a direction of feed V.

In the preferred embodiment illustrated, the system <NUM> comprises an endless belt <NUM> or the like, trained around at least one pulley, not illustrated, having an axis of rotation R directed into the plane of <FIG>.

The feed path has a curved stretch <NUM>, preferably substantially circular.

The belt <NUM> has an inside face 3a directed towards the axis of rotation R and an outside face 3b directed towards the side opposite the axis R.

The feed system <NUM> comprises a plurality of brackets <NUM> for supporting the containers <NUM>.

With particular reference to <FIG>, it may be observed that each bracket <NUM> comprises, for example, a first arm <NUM> connected to the face 3b of the belt <NUM> and extending, preferably, mainly in parallel with the axis R.

Each bracket <NUM> comprises a second arm <NUM> extending from the first arm <NUM>, preferably at right angles thereto.

The second arm <NUM> has a plurality of seats <NUM> - four in the example illustrated - each designed to receive and support a respective container <NUM>.

The seats <NUM> preferably have a main axis "A" which is parallel to the axis R and are preferably in the form of through holes in the arm <NUM>.

As illustrated, the container <NUM> is preferably inserted in known manner into the respective seat <NUM> and rests on the arm <NUM> by means of the lip <NUM>.

In the example illustrated, the machine <NUM> comprises four filling stations <NUM>, <NUM>, <NUM>, <NUM> for filling the containers <NUM> and positioned along the feed path. Each station <NUM>, <NUM>, <NUM>, <NUM> is designed to supply a dose of the product P into a corresponding container <NUM>.

Each station <NUM>, <NUM>, <NUM>, <NUM> comprises a respective filler <NUM>, for example of the screw type with vertical axis, to supply the dose of product P into the corresponding container <NUM>.

In practice, only one container <NUM> is filled in each station <NUM>, <NUM>, <NUM>, <NUM> and the number of filling stations preferably corresponds to the number of seats <NUM> made on each bracket <NUM>.

In the preferred embodiment illustrated by way of example, the container <NUM> located in the seat <NUM> closest to the belt <NUM> is filled in the first station <NUM>, and the containers <NUM> in the seats <NUM> located progressively further from the belt <NUM> are filled, respectively, in the stations <NUM>, <NUM>, <NUM> located downstream of the first station <NUM> in the direction of feed V.

The machine <NUM> comprises a plurality of detecting stations <NUM>, <NUM>, <NUM>, <NUM> - four in the example illustrated - positioned along the feed path.

Each detecting station <NUM>, <NUM>, <NUM>, <NUM> is preferably located downstream of a respective filling station <NUM>, <NUM>, <NUM>, <NUM> according to the direction of feed V, to detect a significant parameter of the dose of product P supplied into the respective container <NUM>.

Each station <NUM>, <NUM>, <NUM>, <NUM> comprises a respective detecting sensor <NUM>, which is a microwave sensor as described in more detail below, configured to detect the aforementioned parameter.

In practice, the parameter is detected in each station <NUM>, <NUM>, <NUM>, <NUM> only in the container <NUM> filled in the filling station <NUM>, <NUM>, <NUM>, <NUM> immediately upstream of the detecting station <NUM>, <NUM>, <NUM>, <NUM> according to the direction of feed V.

Preferably, the number of detecting stations <NUM>, <NUM>, <NUM>, <NUM> preferably corresponds to the number of seats <NUM> made on each bracket <NUM>.

The detecting sensor <NUM> is a microwave sensor configured to detect the moisture and/or density of the product P in each container <NUM>.

More specifically, the microwaves are electromagnetic rays in the electromagnetic spectrum with wavelength between upper radio wave ranges and infrared rays.

The sensor <NUM> is composed of a microwave resonant zone characterized by a resonance peak frequency and a resonance bandwidth.

If a quantity of product P to be measured is placed in the resonant zone, the peak frequency and bandwidth shift, on first approximation, as a function of product mass, whereas their ratio to each other depends only on moisture.

It is thus possible to calculate the density and moisture of the product P based on the variation of the resonance curve.

Thus, knowing the value of the density of the product P and the volume of the container <NUM> containing the product P, it is possible to calculate the weight of the product P in each container <NUM>.

Advantageously, in each station <NUM>, <NUM>, <NUM>, <NUM>, the detecting sensor <NUM> operates at the seat <NUM> previously filled in the filling station <NUM>, <NUM>, <NUM>, <NUM> immediately upstream of the detecting station <NUM>, <NUM>, <NUM>, <NUM> according to the direction of feed V.

The machine <NUM> comprises a control unit, schematically represented as a block <NUM>, in communication with the sensors <NUM>.

The unit <NUM> is configured to process the parameter, and more specifically, the moisture and/or density of the product P, detected by each sensor <NUM>, and to provide a piece of information about the weight of each dose of product P supplied into the corresponding container.

In practice, in a substantially known manner, the unit <NUM> provides, for each container <NUM>, an indication of the weight of the product P dosed into the container <NUM>.

Advantageously, the unit <NUM> is in communication with the fillers <NUM> in the filling stations <NUM>, <NUM>, <NUM>, <NUM> and is configured to drive each filler <NUM> as a function of the weight calculated.

The unit <NUM> controls the filling stations <NUM>, <NUM>, <NUM>, <NUM> based on the quantity of product actually supplied into the respective container <NUM>.

With particular reference to <FIG>, which is a detail showing a first embodiment of the station <NUM>, the detecting sensor <NUM> comprises a cylindrical resonator <NUM> of substantially known type.

As illustrated, the resonator <NUM> is mounted above the bracket <NUM>, in particular above the arm <NUM>.

The resonator <NUM> has a cavity <NUM> having a respective inlet opening.

The resonator <NUM> is mounted in such a way that the cavity <NUM>, and more specifically, the inlet opening thereof, is opposite the seat <NUM> of the container <NUM> to be checked, that is to say, looking at <FIG>, the inlet opening of the cavity <NUM> is directed downwards.

In each station <NUM>, <NUM>, <NUM>, <NUM>, the corresponding cylindrical resonator <NUM> is opposite a respective seat <NUM> housing the container <NUM> to be checked.

The detecting station <NUM> comprises a lifting device <NUM> located on the opposite side of the resonator <NUM> relative to the arm <NUM>.

The device <NUM> comprises a piston <NUM> which is movable, in a substantially known manner, between a lowered position, illustrated by the dashed line in <FIG>, and a raised position.

The piston <NUM> is movable along the axis A of the corresponding seat <NUM> in such manner as to pass through the latter.

The piston <NUM> is configured to transfer the container <NUM>, at least partly, from the seat <NUM> into the cavity <NUM>, passing from the lowered to the raised position and, vice versa, from the raised to the lowered position.

Advantageously, in order to measure at least the moisture from which, as mentioned, the unit <NUM> calculates the weight of the product P dosed into the container <NUM>, the microwave sensor <NUM> can operate even without waiting for the product to settle after lifting.

With reference to <FIG>, which is a detail showing the station <NUM> in a second embodiment of it by way of example, the detecting sensor <NUM> comprises a flat resonator <NUM> of substantially known type.

The resonator <NUM> is opposite the seat <NUM> in such a way as to be opposite the product P inside the container <NUM> so as to scan it with the microwaves to measure the moisture and/or density of the product P to be transmitted to the unit <NUM>.

In order not to interfere with the resonator <NUM>, the bracket <NUM> is made preferably of a plastic or ceramic material, preferably of the low loss type, such as, for example PEEK or HDPE.

With reference to <FIG>, which is a detail showing the station <NUM> in a third embodiment of it by way of example, the detecting sensor <NUM> comprises a resonator of the type known as "fork resonator" of substantially known type, comprising a microwave emitter <NUM> and a corresponding receiver <NUM>.

The emitter <NUM> and the receiver <NUM> are mounted on opposite sides of the arm <NUM> so that the microwaves transmitted between them pass through the corresponding seat <NUM> and the container <NUM> housed therein.

Thus, the product P inside the container <NUM> can be scanned with the microwaves to measure the moisture and/or density of the product P to be transmitted to the unit <NUM>.

In order not to interfere with the emitter <NUM> and receiver <NUM>, the bracket <NUM> is made preferably of a plastic or ceramic material, preferably of the low loss type, such as, for example PEEK or HDPE.

Generally speaking, the microwave device allows detecting the density of the product in the capsule and, knowing the volume of the capsule, also the weight of the product inside.

More specifically, a microwave device allows measuring in known manner the moisture of a product, which can then be correlated with the density. The detecting stations which allow measuring the weight of the product in the containers using microwave sensors can be integrated in and mounted on the same frame as that of all the other machine stations.

It should be noted that there can be more than one sensor <NUM> for each measurement to be performed, so that the data detected can be crossed and a more precise result obtained. In particular, the sensors <NUM> can be in the same detecting station. Alternatively, the sensors <NUM> can be located in successive detecting stations.

It should be noted that using at least one sensor <NUM> makes it possible to recognize the weight of two or more products inside the same container. This is advantageous when a container, for example, contains a layer of coffee and layer of powdered milk and a parameter of each needs to be detected. The weights of the two distinct products can thus be obtained.

It should also be noted that a further sensor <NUM> might also be provided before the filling station in order to take a measurement of the container when it is still empty, so as to obtain the tare weight.

Claim 1:
A machine for making capsules of the type comprising a container (<NUM>) and a dose of product (P) inserted in the container (<NUM>), the container (<NUM>) being preferably a cup-like container (<NUM>) having an inlet opening (<NUM>), through which the product (P) is supplied into the container (<NUM>) before a corresponding lid is applied, and an outer lip (<NUM>) surrounding the inlet opening (<NUM>), said machine comprising a feed system (<NUM>) for feeding at least a container (<NUM>) along a feed path in a direction of feed (V), said feed system (<NUM>) comprising at least a seat for said container (<NUM>), said machine comprising at least one filling station (<NUM>, <NUM>, <NUM>, <NUM>) positioned along the feed path and comprising at least one filling unit (<NUM>) for supplying the dose of product (P) into said container (<NUM>), said machine comprising at least one detecting station (<NUM>, <NUM>, <NUM>, <NUM>) positioned along said feed path immediately downstream of said filling station (<NUM>, <NUM>, <NUM>, <NUM>) according to said direction of feed (V) and comprising a detecting sensor (<NUM>) operating at said seat (<NUM>), said detecting sensor (<NUM>) being designed to detect a first significant parameter of said product supplied into said container (<NUM>), said machine being characterized in that said detecting sensor (<NUM>) is a microwave sensor and said first parameter is the moisture or the density of the dose of product (P) supplied into said first container, wherein the microwave sensor allows detecting the density of the dose of product (P) in the container (<NUM>) and calculating the weight of the dose of product (P) in the container (<NUM>) knowing a volume of the container (<NUM>), the machine comprising a control unit (<NUM>) in communication with the microwave sensor (<NUM>) configured to process said first parameter detected by the microwave sensor (<NUM>), and to provide the weight of the dose of product (P) supplied into the container (<NUM>).