EP2832681A1

EP2832681A1 - Filling head and method

Info

Publication number: EP2832681A1
Application number: EP13178646.9A
Authority: EP
Inventors: Roberto Zoni; Vincenzo Galotto; Simone Campi
Original assignee: Sidel SpA
Current assignee: Sidel SpA
Priority date: 2013-07-30
Filing date: 2013-07-30
Publication date: 2015-02-04
Anticipated expiration: 2033-07-30
Also published as: CN104340941A; EP2832681B1

Abstract

There is described a filling head (9, 9') for filling an article (2) with a pourable product, comprising a duct (11), which defines an outlet mouth (12) for pourable product and which may be arranged either in a closed configuration in which it prevents pourable product from flowing inside article (2); or in a respective open configuration in which it allows pourable product to flow inside article (2); filling head (9, 9') further comprises a closing element (14), which may be arranged, when duct (11) is in open configuration, either in a rest position in which it is detached from mouth (12), when article (2) is, in use, filled with product; or in an operative position in which it is in tight-fluid contact with mouth (12), during a cleaning step of respective first filling head (9, 9'), so as to prevent a cleaning agent from flowing out from mouth (12); filling head (9, 9') comprises an actuator (15, 15') operatively connected to closing element (14) and adapted to move closing element (14) between rest position and operative position.

Description

The present invention relates to a filling head and to a method for filling articles with a pourable product, especially for filling containers with a pourable food product.
Filling heads are known, which are fed with empty containers and output containers filled with a pourable food product.
The filling unit substantially comprises a carousel conveyor rotatable about a rotation axis, a tank containing the pourable food product, and a plurality of filling heads which have respective filling valves.
Filling heads are fluidly connected with the tank and are supported by the carousel conveyor in an eccentric position with respect to the rotation axis of the carousel conveyor.
In greater detail, the filling heads extend along respective vertical axes, are rotated by the carousel conveyor and are provided, at the lower end thereof, with respective outlet mouths for the product to be poured.
The filling heads also define respective ducts which are fluidly interposed between the tank and the mouths, and along which respective filling valves are interposed.
The filling valves can be selectively set between respective open configurations in which they allow the food product to pass through corresponding ducts and mouths and to fill the containers, and respective closed configuration in which they prevent the food product from flowing through the respective ducts.
The containers are gripped by respective gripping elements and are rotated by the carousel conveyor together with the respective filling heads.
The known filling unit also comprises a plurality of closing elements associated to respective filling heads.
During the filling of the containers and when the filling valves are in the respective open positions, the closing elements are normally arranged in respective rest positions, in which they are detached from the mouths of the respective filling heads and, therefore, do not interfere with the food product which is filling the containers.
Periodically, the filling unit undergoes a cleaning step, during which a cleaning agent is circulated inside the filling unit in place of the pourable product.
During the cleaning step, the filling valves are normally set in respective open configurations, so as to ensure that also the whole corresponding duct and mouths are cleaned by the cleaning agent.
In order to prevent the cleaning agent to come out from respective mouths and to waste in the environment, the closing elements are moved in respective operative positions.
When set in the respective operative positions, the closing elements are in tight-fluid contact with the mouths of the respective filling heads, so as to keep the cleaning agent inside the respective filling heads.
In other words, the closing elements act as gaskets which prevent the cleaning agent from wasting inside the environment.
In the known solution, the closing elements are idle relative to corresponding filling heads, are normally arranged in respective rest positions, and comprise respective rollers. Furthermore, the filling station comprises a cam which is fixed relative to the rotation axis of the carousel.
During the filling of the containers, the cam is in a position in which it cannot interact with the rollers. Accordingly, the closing elements remain in respective rest positions.
When it is necessary to carry out the cleaning step, the cam is moved towards the carousel, up to a position in which it interacts with the rollers.
Accordingly, all the closing elements simultanously reach the respective operative positions.
A need is felt within the industry to obtain a filling head with an enhanced flexibility as regard to the movement of the closing elements between the respective rest positions and respective operative positions.
Furthermore, a need is felt to reduce the cost deriving from the use and of the cam and its movement.
Finally, in the known solutions, when the damage of one of the containers to be filled is detected, the damaged container is conveyed with the other containers to a downstream star-wheel and removed by using a dedicate finger.
It goes without saying that the expulsion of the damaged containers results, in the known solutions, in considerable time-losses and cost.
A need is therefore felt within the industry to reduce, as far as possible, the costs due to the expulsion of the damaged container.
It is an object of the present invention to provide a filling head, which allows to meet at least one of the above-identified needs.
According to the present invention, provided a filling head for filling articles with a pourable product, as defined in claim 1.
The present invention also relates to a method of filling articles with a pourable product, as defined in claim 12.
The invention will now be described with reference to the accompanying drawings which illustrate two non-limitative embodiments thereof, in which:

figure 1 is a perspective view of a preferred embodiment of a filling head according to the present invention;
figure 2 is an enlarged view of some particular of the filling head of Figure 1, with parts removed for clarity;
Figure 3 is a perspective view of the filling head of Figures 1 and 2, showing a closing element in a rest position and during a filling step of a container;
Figure 4 is a lateral enlarged view of the filling head of Figure 3, showing the closing element in the rest position and during the filling step of the container;
Figure 5 is a perspective view of the filling head of Figures 1 and 2, showing the closing element in the rest position and before a cleaning step;
Figure 6 is a lateral enlarged view of the filling head of Figure 5, showing the closing element in the rest position and before a cleaning step;
Figure 7 is a perspective view of the filling head of Figures 1 and 2, showing the closing element in an operative position and during the cleaning step;
Figure 8 is a lateral enlarged view of the filling head of Figure 7, showing the closing element in the operative position and during the cleaning step;
Figure 9 is a perspective view of the filling head of Figures 1 and 2, showing the closing element during the expulsion of a damaged article;
Figure 10 is a lateral enlarged view of the filling head of Figure 9, showing the closing element during the expulsion of a damaged article;
Figure 11 and 12 schematically show further components of the filling head of Figures 1 to 10;
Figure 13 and 14 shows further components of the filling head of Figures 1 to 12;
Figure 15 shows a second embodiment of the filling head in accordance of the present invention, with the closing element in the rest position;
Figure 16 shows the second embodiment of the filling head, with the closing element in the operative position; and
Figure 17 schematically shows a filling unit comprising a plurality of filling heads according to the present invention.

With reference to Figure 17, numeral 1 indicates a filling unit for filling containers 2 (shown in Figures 3, 9 and 10) with a pourable food product.
In particular, filling unit 1 is fed with empty containers 2 and fills them with the pourable food product.
Non-limitative examples of the pourable food product consist of fruit juices, tea, beer or energy drinks.
Containers 2 can be made either of glass or plastic.
In the embodiment shown, each container 2 is made of plastic and comprises (Figure 9):

a mouth 3 adapted to allow the filling of container 2 by means of filling unit 1 and the following pouring of the food product from container 2;
a bottom wall 4 opposite to mouth 3; and
a neck portion 6 adjacent to mouth 2 and which is limited at its top by mouth 3.

Furthermore, container 2 comprises a ring 7 arranged at the base of neck portion 6 and below mouth 3.
Filling unit 1 substantially comprises (Figure 17):

a not-shown tank, which contains the pourable food product;
a carousel 8, which rotates about an axis A, vertical in the embodiment shown; and
a plurality of filling heads 9 (only one of which is shown in Figures 1 to 16), which are arranged at a periphery of carousel 8, extend along respective axes B parallel to each other and staggered relative to axis A.

In detail, filling heads 9 receive respective containers 2 at a inlet station I from an upstream conveyor, convey respective containers 2 along an arch-shaped path P having centre on axis A and outputs respective containers 2 at an output station O to a downstream conveyor.
Periodically, filling unit 1 undergoes a cleaning step, during which a cleaning agent is circulated inside filling heads 9 in order to sterilize them.
In the following of the present description, only one filling head 9 will be described in detail, being clear that filling heads 9 are identical to each other.
Filling head 9 comprises, in turn, (Figures 1 to 16):

a body 10;
a body 17;
a duct 11 (only schematically shown in Figures 11 and 12) which is fluidly connected with tank and defines an outlet mouth 12;
a valve 13 (only schematically shown in Figures 11 and 12) interposed along duct 11; and
a gripping device 16 comprising a plate orthogonal to axis B and which defines an open substantially semicircular slot for gripping neck portion 6 of container 2.

Valve 13 may be selectively arranged in:

an open configuration, in which it allows the pourable product from flowing from tank to mouth 12; and
a closed configuration, in which it prevents the pourable product from flowing from tank to mouth 12.

Gripping device 16 is movable parallel to axis B to approach or move away container 2 from mouth 12. The slot of gripping device 16 is open on the opposite side of axis A, and extends about axis B, so as to arrange mouths 3, 12 coaxially with respect to one another during the filling of container 2.
Filling head 9 also comprise a closing element 14 which may be arranged in:

a rest position (Figures 3 to 6), in which closing element 14 is detached from respective mouth 12; and
an operative position (Figures 7 and 8), in which closing element 14 is in tight-fluid contact with mouth 12.

Closing element 14 is arranged in the rest position during the normal filling of respective container 2, so as not to interfere with the pourable product coming out from mouth 12.
In particular, during the cleaning step, valve 13 is in the open configuration, so that the cleaning agent can contact and clean the whole duct 11 and mouth 12.
Still more precisely, during the cleaning step, closing element 14 is arranged in the operative position, so as to prevent the cleaning agent from coming out from mouth 12.
Advantageously, filling head 9 comprises an actuator 15 (Figures 11 and 12) operatively connected to closing element 14 and adapted to move closing element 14 between the rest position and the operative position.
It is important to point out that, due to the fact that actuators 15 are carried by respective filling heads 9, corresponding closing elements 14 move independently from one another between the respective rest positions and the respective operative positions.
Filling head 9 also comprises a sensor 20 (only schematically shown in Figures 11 and 12) capable of detecting whether or not container 2 is damaged, when duct 11 is in the open configuration and during the filling of container 2.
Sensor 20 is also functionally connected to actuator 15.
Furthermore, when sensor 20 detects that container 2 is damaged, actuator 15 displaces closing element 14 from the rest position to the operative position, so as to hit damaged container 2 and expel it from filling head 9.
In the embodiment shown, sensor 20 is a pressure sensor, which senses the pressure inside container 2 during the pressurization thereof.
In greater detail, actuator 15 firstly moves closing element 14 along a first stroke from the rest position (Figures 3 to 6) to an intermediate position (reached immediately after the position shown in Figures 9 and 10), and, then, moves closing element 14 from the intermediate position to the operative position (Figures 7 and 8) along a second stroke.
Still more precisely, in the intermediate position, closing element 14 is coaxial with mouth 12 and arranged at a given distance from mouth 12 along axis B.
The first stroke is helical about an axis C (Figures 1, 2, 4, 6, 8, and 11 to 14) parallel to axis B. In other words, along the first stroke, actuator 15 causes the simultaneous rotation of closing element 14 about axis C and the translation of closing element along axis C and towards mouth 12.
The second stroke is a translation of closing element 14 along axis C.
With reference to Figures 13 and 14, filling head 9 comprises a body 25 which is connected to body 11.
Body 25 projects from body 11 and is arranged on the opposite radial side of body 11 with respect to axis A.
Body 25 has, in the embodiment shown, a length along an axis C parallel and staggered from axis B, and vertical in the embodiment shown.
Body 25 is hollow and defines a cavity 24.
Body 25 comprises:

a top end wall 35 lying on a horizontal plane; and
a lateral wall 36 cylindrical of axis C, and which comprises a shoulder 37 and an enlarged portion 38.

Wall 35 and shoulder 37 are axially opposite with respect to one another.
Body 25 also comprises:

a shaft 26 housed inside cavity 24 rotatably about axis C and slidably along axis C; and
a pin 27 fixed with respect to axis C and which engages a slot 28 defined by shaft 26.

In detail, shaft 26 comprises, proceeding from a top axial end 30 facing wall 35 of body 25 towards a bottom axial end 31 arranged outside body 25,:

slot 28;
an enlarged portion 32;
a section 33 to which closing element 14 is eccentrically fitted; and
a section 34 to which an appendix 22 is fitted.

Portion 38 of wall 36 is axially interposed between shoulder 37 and wall 36, and houses portion 32 of shaft 26.
Appendix 22 moves integrally with shaft 26 and comprises a hitting surface 21, which hits damaged container 2 when closing element 14 reaches the intermediate position, so as to ease the removal of damaged container 2.
Still more precisely, hitting surface 21 of appendix 22 is positioned relative to closing element 14, in such a way that when closing element 14 reaches the intermediate position, hitting surface 21 hits against container 2 (Figures 9 and 10).
In the embodiment shown, hitting surface 21 is curved. Closing element 14 substantially comprises:

a circular plate 42 having an axis D; and
an arm 43 fitted to section 33 of shaft 26.

In detail, arm 43 has a first end fitted to section 33 of shaft 26 and a second end, opposite to first end, which defines plate 42.
When closing element 14 is in the rest position, axis D is staggered from axis B of mouth 12 (Figure 13).
When closing element 14 is in the intermediate position, axis D is coaxial with axis B of mouth 12, but closing element is axially detached from mouth 12.
When closing element 14 is in the operative position, axis D is coaxial with axis B of mouth 12, and closing element 14 is in tight-fluid contact with mouth 12 (Figure 14).
Closing element 14 both integrally rotates with shaft 26 about axis C and integrally translates with shaft 26 along axis C.
Pin 27 extends along an axis E orthogonal to axis A, B and C and horizontal, in the embodiment shown.
Slot 28 comprises, proceeding from end 30 towards enlarged portion 32, (Figure 14):

a helix stretch 45 extending about axis C; and
a stretch 46 parallel to axis C.

With reference to Figures 13 and 14, actuator 15 is capable of exerting an action directed along axis C on shaft 26. That action causes, due to the shape of slot 28, the roto-translation of shaft 26 and the movement of closing element 14 along the first stroke and, then, the translation of shaft 26 parallel to axis C and the movement of closing element 14 along the second stroke.
Accordingly, when closing element 14 is arranged in the rest position (Figure 13) and shaft 26 receives an action parallel to axis C and upwards directed (with reference to Figure 13), shaft 26 at first upwards move along a helical trajectory about axis C and then upwards translates parallel to axis C.
On the contrary, when closing element 14 is arranged in the operative position (Figure 14) and shaft 26 receives an action parallel to axis C and downwards directed (with reference to Figure 14), shaft 26 at first downwards moves along a helical trajectory about axis C and then downwards translates parallel to axis C.
In particular, shaft 26 and cavity 24 defines therebetween:

a first variable volume chamber 29 axially extending between top end 30 of shaft 26 and a top wall 35 of body 25; and
a second variable volume chamber 23 axially defined between enlarged portion 32 of shaft 26 and a shoulder 37 of body 25.

In the embodiment shown, actuator 15 is pneumatic.
Still more precisely, actuator 15 comprises (Figures 11 to 14):

a control unit 49.
an electro-valve 50;
a duct 51 (only schematically shown in Figures 11 to 14) which extends between electro-valve 50 and chamber 29;
an electro-valve 52; and
a duct 53 (only schematically shown in Figures 11 to 14) which extends between electro-valve 52 and chamber 23.

In particular, control unit 49 controls, on the basis of the signal of presence of damaged container 2 generated by sensor 20, electro- valves 50, 52 so as to connect one of ducts 51, 53 to a source of air in pressure and the other one of ducts 51, 53 to a discharge.
In particular, the arrows in Figure 11 and 14 indicate the airflow direction inside ducts 51, 53, when they are connected either to a source of air in pressure or to a discharge.
When duct 51 (53) is connected to the source of air in pressure and duct 53 (51) is connected to the discharge, the pressure in chamber 29 (23) is made greater than the pressure in chamber 23 (29). In this way, shaft 26 undergoes a downwards (upwards) force parallel to axis C.
In the embodiment shown, control unit 49 and electro- valves 50, 52 are housed inside body 17.
The operation of filling unit 1 is described with reference to only one filling head 9 and to the corresponding container 2 and closing element 14.
The operation of filling unit 1 is also described, starting from a condition in which closing element 14 is in the rest position and pin 27 is in contact with a top end of stretch 45 of slot 28 (Figures 11 and 13).
Filling head 9 is driven in rotation about axis A by carousel 8 and receives empty container 2 at station I.
In particular, container 2 is gripped by gripping device 16 and is coaxial with axis B of mouth 12.
Filling head 9 fills container 2 along a path P extending from station I to station O.
Along path P, valve 13 is arranged in the open configuration, in which it allows the pourable product to flow from tank to container 2, through duct 11 and mouth 12.
In case sensor 20 detects that container 2 is not damaged, the filling goes on until a given level of the pourable product inside container 2 is reached.
At this stage, valve 13 is set in the closed configuration and filling head 9 outputs filled container 2 to a downstream not-shown conveyor at station O.
In case sensor 20 detects that container 2 is damaged, in the embodiment shown by detecting that container 2 cannot be properly pressurized before the filling, actuator 15 moves closing element 14 from the rest position to an intermediate position (reached immediately after than the positions shown in Figures 9 and 10) and then from the intermediate position to the final position (figure 7 to 8) .
As shown in Figures 9 and 10, when closing element 14 reaches the intermediate position, it hits damaged container 2 gripped by gripping device 16 and causes the expulsion of damaged container 2.
Accordingly, container 2 is expelled along path P by filling head 9.
In greater detail, closing element 14 is firstly moved by actuator 15 from the rest position to the intermediate position along the upwards helical first stroke of axis C. At the end of that first stroke, axis D of closing element 14 and axis B of mouth 12 coincide, but closing element 14 is still spaced from mouth 12 along coinciding axes B, D (Figures 9 and 10).
Closing element 14 is then moved by actuator 15 from the intermediate position to the operative position along the upwards second stroke, which is parallel to axis B and terminates when closing element 14 tight-fluid contacts mouths 12.
Still more precisely, in order to move closing element 14 from the rest position to the operative position, control unit 49 controls electro- valves 50, 52, so that the pressure in duct 53 is made higher than in duct 51 (Figures 11 and 13).
As a result, the pressure in chamber 23 is made higher than the pressure in chamber 29 and shaft 26 is subject to an upward force parallel to axis C.
Starting from the condition of Figure 13, helix stretch 45 of slot 28 is engaged by pin 27. Accordingly, the upward force on shaft 26 causes the simultaneous rotation of shaft 26 about axis C and upwards translation of shaft 26 parallel to axis C.
Closing element 14 moves along the first stroke which terminates when pin 27 engages stretch 46 of slot 28.
When closing element 14 is at the end of the first stroke, appendix 22 contacts container 2 and contributes the expulsion of container 2 (Figures 9 and 10).
Subsequently, the upwards action on shaft 26 simply causes the upward movement of shaft 26, which terminates when pin 27 abuts against the lower end of stretch 46 of slot 28, as shown in Figure 14.
Accordingly, closing element 14 moves along the second stroke, which terminates when closing element 14 is in tight-fluid contact with mouth 12.
Once closing element 14 has reached the operative position, control unit 49 controls electro- valves 50, 52, so that the pressure in duct 51 is made higher than in duct 53 (Figure 14).
As a result, the pressure in chamber 29 is made higher than the pressure in chamber 23 and shaft 26 is subject to a downward force parallel to axis C.
Accordingly, actuator 15 moves back closing element 14 along the second stroke from the operative position to the intermediate position, and then moves back closing element 14 along the first stroke from the intermediate position to the rest position.
It is important to stress that closing element 14 of one filling head 9 can be moved independently of other closing elements 14 of other filling heads 9.
In this way, the expulsion of one or more damaged container 2 along path P does not affect the correct filling of the other non-damaged containers 2.
Periodically, filling unit 1 undergoes a cleaning step.
More precisely, the tank is filled with the cleaning agent, and the latter is circulated inside filling heads 9 in the place of the pourable product.
During the cleaning step, valves 13 are in set in the respective open configurations, so that the cleaning agent can contact and sterilize whole ducts 11 and corresponding mouths 12.
In order to prevent the cleaning agent from coming out from mouths 12 and to waste in the environment surrounding filling unit 1, all actuators 15 of all filling heads 9 move all closing elements 14 in the respective operative positions.
The movement of closing elements 14 from the respective rest positions to the respective operative positions is identical to the one previously described with reference to only one closing element 14 during the filling of container 2, and simply differs for the fact that no containers 2 are arranged below mouths 12 during the cleaning step. Accordingly, closing elements 14 and appendix 22 do not hit any damaged containers 2, when they all together move towards the respective operative positions during the cleaning step.
At the end of the cleaning step, actuators 15 simultaneously move closing elements 14 from the respective operative positions to the respective rest positions, in the same way as previously described with reference to only one closing element 14 during the filling of container 2.
With reference to Figures 15 and 16, 9' indicates a second embodiment of the filling head.
Filling head 9' is similar to filling head 9 and will be disclosed hereinafter only insofar as it differs from the latter; corresponding parts or equivalents of filling head 9, 9' will be indicated, where possible, by the same reference numerals.
In particular, filling head 9' differs from filling head 9 in that actuator 15' is capable of exerting both a torque about axis C and an action along axis C on shaft 26'.
Actuator 15' comprises:

one or more permanent magnet 60' fixed to shaft 26';
and
a pair of coils 61' carried by body 25 and magnetically coupled with magnet 60'.

The magnet 60' and coils 61' are shaped in such a way that the magnetic excitation of coils 61' generates both an action parallel to axis C and a torque about axis C on magnet 60' and, therefore, on shaft 26'.
Accordingly, shaft 26' differs from shaft 26 for not comprising any slot 28.
The operation of filling head 9' differs from the operation of filling head 9 in that actuator 15' exert on shaft 26' both a torque about axis C and a force along axis C. In this way, actuator 15' directly causes both the rotation about axis B and the translation along axis C of shaft 26' and, therefore, of closing element 14.
From an analysis of the features of filling head 9, 9' and of the filling method made according to the present invention, the advantages it allows to obtain are apparent.
In particular, actuator 15, 15' is carried by filling head 9, 9'.
Accordingly, closing element 14 of each filling head 9, 9' may be moved independently of the other closing elements 14 of remaining filling head 9, 9', and with a movement law different from the movement laws of the other closing elements 14 of remaining head 9, 9'.
In the light of the above, filling head 9, 9' is far more flexible than the solution described in the introductory part of the present description as regards to the movement of closing elements 14.
Moreover, there is no longer need for a costly and cumbersome cam which interacts with closing elements 14 only during the cleaning step, for moving closing elements 14 into respective operative configurations.
Furthermore, closing element 14 of one filling head 9, 9' may be arranged in the operative position whereas closing elements 14 of remaining filling heads 9, 9' remain in the respective rest positions.
Accordingly, closing element 14 can be advantageously used, during the filling of container 2 and in case that container 2 is damaged for hitting damaged container 2 and expelling it from filling head 9.
In this way, damaged containers 2 are expelled along path P and are not conveyed downstream of filling unit 1.
Accordingly, there is no need of dedicated tools arranged downstream of filling unit 1 for removing damaged containers 2.
Finally, it is apparent that modifications and variants not departing from the scope of protection of the claims may be made to filling head 9, 9' and to the filling method.
In particular, actuator 15, 15' could move respective closing element 14 only along the first respective stroke and between the respective rest position and intermediate position, when a damaged container 2 must be expelled.
Furthermore, filling head 9, 9' could comprise only part of actuator 15, 15', in particular only body 25, shaft 26 and chambers 23, 29; control unit 49, electro- valves 50, 52 and ducts 51, 53 being external to filling head 9, 9'.
Furthermore, sensor 20 could be different from the pressure sensor described in the present description.
Finally, actuators 15, 15' may be electro-magnetic, so as to exert an electro-magnetic force on shaft 26 directed parallel to axis C.

Claims

A filling head (9, 9') for filling an article (2) with a pourable product, comprising:
- a duct (11), which defines an outlet mouth (12) for said pourable product and which may be arranged either in:
a closed configuration in which it prevents said pourable product from flowing inside said article (2); or in

an open configuration in which it allows said pourable product to flow inside said article (2);

said filling head (9, 9') further comprising a closing element (14), which may be arranged, when said duct (11) is in said open configuration, either in:

- a rest position in which it is detached from said mouth (12), when said article (2) is, in use, filled with said product; or in

- an operative position in which it is in tight-fluid contact with said mouth (12), during a cleaning step of respective said first filling head (9, 9'), so as to prevent a cleaning agent from flowing out from said mouth (12);
characterized by comprising at least part of an actuator (15, 15') operatively connected to said closing element (14) and adapted to move said closing element (14) between said rest position and said operative position.
The filling head of claim 1, characterized by comprising a sensor (20) capable of detecting whether or not said article (2) is damaged, when said duct (11) is in said open configuration and during a filling step of said article (2) with said pourable product;
said actuator (15, 15') being operatively connected to said sensor (20) and configured for moving said closing element (14) towards said operative position during the filling of said article (2), so as to hit said article (2) and expel it from said filling head (9, 9').
The filling head of claim 1 or 2, characterized in that said closing element (14) may be rotated by said actuator (15, 15') along a first stroke and between said rest position and an intermediate position about a first axis (C), which is parallel to a second axis (B) of said mouth (12);
said closing element (14) being also movable by said actuator (15, 15') parallel to said first axis (C), along a second stroke, and between said intermediate position and said operative position;
said intermediate position being interposed between said rest position and said operative position;
said article (2) being arranged, in use, coaxially with said mouth (12) during the filling, so that said closing element (14) hits, in use, said article (2) when it reaches said intermediate position.
The filling head of claim 3, characterized in that said closing element (14) may also be moved parallel to said first axis (C) and between said rest position and said intermediate position, so that said closing element (14) moves along an helical path coaxial with said first axis (C) along said first stroke.
The filling head of claim 4, characterized by comprising:
- a shaft (26) rotatable about said first axis (C) and to which said closing element (14) is eccentrically fitted with respect to said first axis (C); and

- a pin (27) fixed relative to said first axis (C) and which engages a slot (28) defined by said shaft (26);
said actuator (15, 15') being controllable to exert an action parallel to said first axis (C) onto said shaft (26);
said slot (28) having at least one stretch (45) shaped as a helix, so that when said shaft (26) is subjected to an action parallel to said first axis (C), the movement of said slot (28) relative to said pin (27) causes said shaft (26) and, therefore, said closing element (14) to simultaneously rotate about said first axis (C) and to move parallel to said first axis (C) between said rest position and said intermediate position and along said first stroke.
The filling head of any one of claims 2 to 5, characterized by comprising an appendix (22) operatively connected to said closing element (14) and adapted to further hit said article (2) to ease the expulsion of the latter.
The filling head of claim 6, characterized in that said appendix (22) is eccentric with respect to said first axis (C) and moves integrally with said closing element (14).
The filling head of claim 5 to 7, characterized in that said actuator (15) is pneumatic or electro-magnetic.
The filling head of any one of claims 1 to 4, characterized in that said actuator (15') is capable to simultaneously exert both a torque about said first axis (C) and a force parallel to said first axis (C) onto said closing element (14).
A filling unit (1), characterized by comprising a first filling head (9, 9') and a second filling head (9, 9') according to any one of the foregoing claims;
said first filling head (9, 9') and said second filling head (9, 9') comprising respectively a first said closing element (14) and a second said closing element (14);
said first closing element (14) and said second closing element (14) being movable between said rest position and said operative position independently of one another.
The filling unit of claim 10, when depending on any one of claims 2 to 9, characterized by comprising a carousel (8) which drives said first filling head and said second filling head (9, 9') together along a filling path (P);
said first closing element (14) and second closing element (14) reaching said intermediate position and expelling, in use, said damaged article along said path (P).
A method of filling an article with a pourable product, comprising the steps of:
- filling an article (2) by displacing a duct (11) of a filling head (9, 9') in an open configuration, in which said duct (11) allows said pourable product to flow inside said article (2);

- cleaning said filling head (9, 9') by circulating a cleaning agent inside said filling head and by leaving said duct (11) in said open configuration, at the end of said step of filling;
said step of filling comprising the step of keeping a closing element (14) in a rest position, in which it is detached from an outlet mouth (12) of said duct (11);
said step of cleaning comprising the step of moving said closing element (14) into an operative position, in which it is in tight-fluid contact with said mouth (12), so as to prevent said cleaning agent from coming out from said mouth;
characterized by comprising the step of moving said closing element (14) between said rest position and said operative position by using an actuator (15, 15'), which is at least in part carried by said filling head (9, 9').
The method of claim 12, characterized by comprising the steps of:
- detecting whether or not said article (2) is damaged, during said step of filling;

- displacing said closing element (14) form said rest position to said operative position, in case said article (2) is damaged;
said step of displacing comprising the step of hitting said article (2) with said closing element (14) and expelling it from said filling head (9, 9').
The method of claim 13, characterized in that said step of displacing comprises the steps of:
- firstly at least rotating said closing element (14) about a first axis (C) and along a first stoke, so as to move said closing element (14) from said rest position to an intermediate position, in which said closing element (14) is substantially coaxial with and axially spaced from a mouth (12) of said filling head (9, 9'); and

- subsequently translating said closing element (14) along said first axis (C) and along a second stroke, so as to arrange said closing element (14) in said operative position.
The method of claim 13 or 14, characterized in that said step of filling comprises the step of conveying said filling head (9, 9') together with said article (2) along a path (P);
said step of hitting being carried out along said path (P), so that said damaged article (2) is expelled along said path (P).