EP2829261B1 - Capsule filling device and method for filling a capsule with filling materials - Google Patents

Description

The invention relates to a capsule filling device for filling capsules with a filling material of the type specified in the preamble of claim 1 and a method for operating such a capsule filling device.

For swallowing provided capsules, for example, hard gelatin or the like consist of a capsule lower part and an attached capsule shell. For filling with a filling material in the form of a powder, granules or the like. The initially loose stacked capsule parts are separated. After filling the contents into the individual capsule lower part, the capsule is closed and completed by attaching the capsule upper part.

Such a filling process is performed on clocked capsule filling and closing machines, which are usually designed as so-called rotary transfer machines See, for example EP0194505 ,

, Here, a turntable with capsule receptacles and various, arranged around the turntable, stationary processing stations are provided. The number and configuration of the processing stations can vary as needed. Typically, a first station is formed as an empty capsule insertion and separation station followed by one or more filling stations. In a closing station, the capsules are closed by means of the previously separated capsule shell. In the working direction, at least one ejection station is then provided, in which the filled and sealed capsules are ejected from the capsule receptacle for further processing. Another processing station is provided for cleaning the capsule receptacle, as the Filling process with the dry and granular filling material leads to an unavoidable dust load on the capsule holder. The embodiment as a rotary transfer machine entails a limited space. This in turn means that the number of stations and their size are limited. At the same time, however, the demands on productivity and the complexity of various work steps to be performed are increasing. There is a need for clearance for additional processing stations, but there is no room for existing concepts of rotary transfer machines.

The invention has the object of developing a generic Kapselfülleinrichtung such that without increasing the space additional space for further processing tasks is created.

This object is achieved by a capsule filling device with the features of claim 1.

The invention is further based on the object of specifying a method for operating such a capsule filling device, by means of which the capsule ejection and the subsequent cleaning of the capsule holder can be performed within a single working cycle.

This object is achieved by a method having the features of claim 10.

According to the invention it is provided that the ejection station is provided with a suction device. The suction device comprises a movable suction head, which can be moved back and forth between a passive ejection position and an active suction position. In its passive ejection position, the suction head releases the capsule receptacle for the ejection of the capsules. In its active suction position, the suction head is in register with the capsule receptacle for the purpose of cleansing the capsule receptacle.

In a corresponding operating method according to the invention, a cycle of the following method steps is carried out in the ejection station over the duration of a single working cycle:

First, the capsule holder, which carries the filled and sealed capsules, moved by means of the turntable to the ejection station. There, the capsules are ejected from the capsule holder, while the suction head of the suction device is in its passive, the capsule holder releasing ejection position. Subsequently, the suction head is moved from its passive ejection position to its active suction position. After this is done, the capsule holder is sucked cleansing by means of the suction head. Subsequently, by means of rotation of the turntable, the emptied and cleaned capsule receptacle is moved to the next processing station, while a subsequent capsule receptacle with capsules is fed to the ejection station for a new ejection and suction process. During the latter step, or as a separate step, the suction head is moved from its active suction position back to its passive ejection position so that the cycle of operations described above can begin again.

By the movable suction head is achieved that the process of capsule ejection and the process of cleaning suction in a station, namely the ejection station, can be performed summarized, without that both steps collide with each other. For the suction neither a separate processing station nor a separate clock cycle is required. The limited space of the rotary transfer machine creates space that can be used for a processing station with different task. For example, it is possible to install an additional filling station. In particular, however, there is the possibility of the design and filling of double-row capsule receptacles, for which a second insertion and separation station as well as an additional filling station are required. The space required for this is freed by dispensing with a separate cleaning or suction station.

For example, the suction head can be translationally moved between its two positions. In a preferred embodiment, the suction head is designed as a pivotable ejection flap for discharging the ejected capsules in the passive ejection position. The pivoting movement allows high clock rates with low inertial forces occurring. By the pivoting movement is a double use of the suction head not only for the suction, but also for the ejection possible by the suction head favors in its passive ejection position by a corresponding inclination, the derivative of the ejected capsules.

The capsule receptacle has in conventional design individual receiving pockets for each capsule. It may be expedient to design the suction head, for example in the form of a suction cup with a correspondingly large suction opening, by means of which all receiving pockets are sucked. In a preferred embodiment, a plurality of suction channels are formed in the suction head, each having a corresponding with a receiving pocket suction opening. In the active suction position, the suction openings are in register with the receiving pockets. As a result, a targeted suction with great effectiveness is possible.

In an advantageous embodiment, the receiving pockets are arranged in pairs in two rows in the capsule receptacle. Here, the suction channels are branched Y-shaped and formed with pairs of suction openings for each pair of receiving pockets. The inventive summary of the capsule output and the suction in only one station, the design of double-row capsule receptacles without additional space requirement is possible, which significantly increases the productivity of the capsule filling. In conjunction with the aforementioned Y-shaped branched suction channels while maintaining the clock rate a targeted and reliable cleaning or suction of all individual receiving pockets possible.

In a preferred development of the capsule filling device according to the invention, in addition to the suction device, the ejection station also has a blow-out device with blower channels for cleaning out the capsule holder. In particular, the Ejection station ejection pins for ejecting the filled capsules from the capsule receptacle, wherein the blast channels are formed in the ejector pins. In the associated operating method, the ejection pins are moved out of a rest position to eject the filled capsule into the capsule holder. In an opposite retraction movement and at the same time active suction a cleansing blowing out of the capsule holder is made by means of the ejector pins.

The blowing out thus takes place during the retraction movement, which is required in any case, so that no additional time is required. The process of blowing out more than aspiration allows a targeted guidance of the air flow, whereby even persistently adhering powder or dust residues can be removed. The simultaneously active suction ensures that the said powder and dust residues do not get into the environment or other machine parts, so that overall an effective cleaning is achieved.

For the design of the blower duct different designs are possible. Suitably, the blower channel is formed in particular in its design in the ejector pin by a hollow and frontally sealed tube, in the peripheral wall blow-out are formed. The blow-out slots have slot axes which are advantageously inclined with respect to the longitudinal direction and the radial direction of the respective blow duct to the suction towards. As a result, a directed blowing in particular of the peripheral walls of the receiving pockets with simultaneous effective extraction is possible.

In a preferred embodiment, the suction head is in its passive ejection position to a sealing surface such that the one or more suction channels formed in the suction head are sealed flow-tight. In the active suction position, the one or more suction channels are released from the sealing surface. In a corresponding operating method, the vacuum source of the suction device is active during the entire cycle. The vacuum source does not need to be switched off. The suction is therefore only by the pivoting position of the Suction head on or off, which is possible with low response times and high clock rates.

Fig. 1

in einer Draufsicht den Drehtisch einer erfindungsgemäß ausgeführten Kapselfülleinrichtung mit zweireihigen Kapselaufnahmen und angedeuteten, um den Drehtisch herum angeordneten Bearbeitungsstationen,

Fig. 2

in einer schematischen Schnittdarstellung die erfindungsgemäße Auswurfstation mit einer dorthin bewegten Kapselaufnahme des Drehtisches nach Fig. 1 zu Beginn eines Bearbeitungszyklus' mit einem in eine passive Auswurfposition verschwenkten Saugkopf,

Fig. 3

die Anordnung nach Fig. 2 beim Ausstoßen der Kapseln,

Fig. 4

in einer schematischen Längsschnittdarstellung einen Auswurfstift der Anordnung nach den Fig. 2 und 3 mit einem integrierten Blaskanal und umfangsseitig angeordneten Ausblasschlitzen,

Fig. 5

die Anordnung nach den Fig. 2 und 3 nach dem Auswerfen der Kapseln und mit in seine aktive Saugposition verschwenktem Saugkopf, und

Fig. 6

die Anordnung nach Fig. 5 beim Zurückziehen der Auswurfstifte während eines gleichzeitigen Ausblas- und Absaugvorganges.

An embodiment of the invention is described below with reference to the drawing. Show it:

Fig. 1

in a plan view, the turntable of a capsule filling device according to the invention with two-row capsule receptacles and indicated processing stations arranged around the turntable,

Fig. 2

in a schematic sectional view of the ejection station according to the invention with a capsule receptacle of the turntable moving there Fig. 1 at the beginning of a processing cycle with a suction head pivoted into a passive ejection position,

Fig. 3

the arrangement after Fig. 2 when ejecting the capsules,

Fig. 4

in a schematic longitudinal sectional view of an ejector pin of the arrangement according to the FIGS. 2 and 3 with an integrated blow channel and circumferentially arranged blow-out slots,

Fig. 5

the arrangement after the FIGS. 2 and 3 after ejection of the capsules and with the suction head pivoted into its active suction position, and

Fig. 6

the arrangement after Fig. 5 when retracting the ejector pins during a simultaneous blow-out and suction.

Fig. 1 shows in a plan view of the central part of a capsule filling device according to the invention designed to fill into Fig. 2 shown capsules 14 with a dry, free-flowing medium. The contents may be provided in the form of a powder, granules or the like. This may be a pharmaceutical preparation or order to act a dietary supplement. The capsules 14 ( Fig. 2 ) consist of a capsule lower part 29 and an attached capsule top 31, both of which are made of hard gelatin, for example.

The capsule filling device according to Fig. 1 comprises a turntable 11, which is rotationally drivable about a vertical axis of rotation 13 according to an arrow 31 in clocked steps. On a peripheral region 12 of the turntable 11, a number of capsule receptacles 15 is arranged at regular angular intervals. In the illustrated embodiment, a total of ten capsule receptacles 15 are provided. But it can also be a different number appropriate. The capsule receptacles 15 contain at least one row of receiving pockets 18 for receiving the capsules 14. In the preferred embodiment shown, two parallel rows of paired receiving pockets 18 are provided.

From the simultaneous synopsis of Fig. 1 and 2 It is clear that each capsule receptacle 15 consists of one fixed to the peripheral region 12 of the turntable 11 lower part receptacle 31 and a relatively pivotable upper part receptacle 32. Around the turntable 11 around several fixed, so not rotated with the turntable 11 processing stations are positioned, which are shown only schematically and not in detail with the exception of an ejection station 10 described in more detail below. The number of processing stations corresponds to the number of capsule receptacles 15, so that in each angularly clocked rotational position of the turntable 11, each capsule receptacle 15 comes to lie in the access area to a processing station.

According to the preferred embodiment shown, the two first processing stations are each an insertion and separation station 1, 2, in which provisionally mated, from capsule base 29 and capsule top 30 ( Fig. 2 ) existing empty capsules successively first in a first row of receiving pockets 18 and then in a second deer of receiving pockets 18 are used, in which case a separation of the attached capsule shell 30 from the capsule base 29 is carried out. The next processing station is a separation station 3. In the transition from the second insertion and Separation station 2 to the separation station 3, the upper part receiving 32 is pivoted with the capsule upper parts 30 held therein with respect to the lower part receiving 31 with the capsule lower parts 29 held therein. Faulty, not separate empty capsules are eliminated in the separation station 3.

Here, a total of three filling stations 4, 5, 6, in which the capsule lower parts 29 held in the lower part receptacles 31 are filled with the intended filling material, follow the separating station 3. It may be sufficient to provide only one or two filling stations. The arrangement of several, here a total of three filling stations 4, 5, 6 allows the filling of capsule parts 29 in two rows of receiving pockets 18, wherein optimally also a filling with different contents can be provided.

After passing through the last filling station 6 takes place in a Einschwenkstation 7 pivoting the upper part receptacle 32 back into the aligned position relative to the lower part receiving 31. In the subsequent closing station 8, the capsules 14 are closed by the previously withdrawn or separated capsule tops 30 back on the filled capsule bottoms 29 are pushed and latched. At the closing station 8 are still close to two ejection stations 9, 10 at. In the first ejection station 9 tested and found to be bad capsules 14 are ejected. In the subsequent second ejection station 10, the remaining capsules 14 found to be well are ejected and sent for further processing. However, it may also be expedient to dispense with the first ejection station 9 for excreting the bad capsules and instead to provide only one ejection station 10, in which case the separation of bad capsules takes place at a later time outside the capsule filling device shown here.

The description of the processing stations provided here serves only as an example. It is also possible to provide other processing stations with different tasks and / or in different numbers. In any case, the capsule filling device comprises at least one ejection station 10, whose embodiment according to the invention is described below in connection with FIGS Fig. 2 to 6 is described.

Fig. 2 shows in a schematic cross-sectional view of the second ejection station 10 after Fig. 1 Here, it can be clearly seen that a pair of receiving pockets 18 corresponding to the two in Fig. 1 shown rows of receiving pockets 18 each contains an already filled capsule 14. The capsule bases 29 are held in the lower part receptacle 39, while the capsule tops 30 are held in the upper part receptacle 32. In the state shown, however, the capsule tops 30 are already attached to the capsule bottoms 29 previously filled with the contents. In addition, already in the first ejection station 9 ( Fig. 1 ) has taken place an ejection of badly found capsules 14, so that now in the second ejection station 10 shown here the ejection of the remaining, found to be good capsules 14 from the receiving pockets 18 of the capsule receptacle 15 is imminent. For this purpose, the ejection station 10 for each individual receiving pocket 18 each have an ejector pin 23. The ejector pins 23 are below the capsule receptacle 15 in a rest position and are designed for a vertical ejection movement from bottom to top, as described below in connection with Fig. 3 is described.

The ejection station 10 further comprises a suction device 16 with a movable suction head 17 and optionally also a blow-out device 21 with blow channels 22. In the suction head 17, at least one suction channel 19 is formed with at least one suction opening 20. Preferably, in an optional single-row embodiment of the capsule receptacle 15, a number of suction channels 19 are provided, which corresponds to the number of receiving pockets 18. In the preferred embodiment shown here with a double-row configuration of the capsule receptacle 15, the suction head 17 contains suction channels 19 in a number which is equal to the number of pairs of receiving pockets 18. In this case, each suction channel 19 is branched in a Y shape and opens in the direction of the capsule receptacle 15 into two respective suction openings 20 corresponding to the pairs of receiving pockets 18.

The suction device 16 further comprises a housing 33 in which a collecting channel 34 is formed. The collecting channel 34 establishes a pressure and flow-transmitting connection between the suction head 17 and a vacuum source 27 shown schematically. The suction head 17 is pivotally mounted on the housing 33 about a pivot axis 37 lying parallel to the rows of receiving pockets 18. For a flow-proof pivotal mounting of the suction head 17 is provided with a concentric with the pivot axis 37 formed lateral surface 36 in the form of cylinder sections. Corresponding to the lateral surface 36, a cylindrically shaped bearing seat 35 is formed in the housing 33, in which the lateral surface 36 slides fluid-tight and pressure-tight in a pivoting movement about the pivot axis 37. As a result, a flow and pressure transmitting connection between the collecting channel 34 and the individual suction channels 19 is ensured.

On its underside facing the capsule receptacle 15, pairs of channel sections 38 are formed in the housing 33, whose number, position and size correlate with the pairs of receiving pockets 18. Further, a cylindrical portion-shaped sealing surface 26 is formed on the housing 33, which extends from an area laterally of the channel portion 38 to above the channel portions 38 addition. In the region of its suction openings 20, the suction head 17 is likewise configured in the manner of a cylinder section in a manner correlating with the sealing surface 26 and lies sealingly against the sealing surface 26. Function and operation of the suction device 16 will be described below in more detail.

For the formation of the blow-out device 21, separate blow channels 22 may be provided in addition to the ejection pins 23. In the preferred embodiment shown, a respective blowing channel 22 is formed in each case an ejector pin 23. If necessary, the blower channels 22 can be connected in a flow-pressure-transmitting manner with an overpressure source 28, which is only indicated schematically, in a manner not shown. As blowing medium for the blow-out 21 different technical gases come into consideration. In a preferred and simple embodiment, the overpressure source 28 provides compressed air as blowing medium for the blow-out device 21.

With the arrangement described above, the method steps described below are carried out cyclically at the ejection station 10 shown here:

Fig. 2 shows the arrangement at the beginning of the aforementioned cycle 'of process steps. By a clocked rotary motion of the turntable 11 ( Fig. 1 ), a capsule receptacle 15 with filled and sealed capsules 14 was previously moved to the second ejection station 10. The suction head 17 is pivoted about its pivot axis 37 in a passive ejection position. Here it lies with its cylindrical, the suction openings 20 contained end face at the non-interrupted region of the sealing surface 26 side of the channel portions 38 sealingly, so that the at least one, here all the suction head 17 formed in the suction channels 19 are sealed at their suction ports 20 fluid-tight. Preferably, but not necessarily, the negative pressure source 27 is active in this state, for example in the form of a pump. Due to the sealing effect of the sealing surface 26, however, no suction takes place. Furthermore, the suction head 17 is pivoted so far laterally that the channel sections 38 and the underlying receiving pockets 18 are completely released from the suction head 17, as a result, the capsules 14 can be ejected from their receiving pockets 18 through the channel sections 38 upwards. The ejection pins 23 are initially still in a lower rest position, in which they do not yet protrude into the receiving pockets 18 and not yet in contact with the capsules 14.

Fig. 3 shows the arrangement after Fig. 2 in the execution of a subsequent process step within the same work cycle at the same ejection station 10. Starting from the in Fig. 2 shown rest position, the ejector pins 23 were moved up into the receiving pockets 18 and through them, so that the capsules 14 are ejected from their receiving pockets 18 through the channel sections 38 upwards. The suction head 17 resting laterally in its passive ejection position acts here as a pivotable ejection flap for discharging the ejected capsules 14 radially inwards due to its inclination to the axis of rotation 13 of the turntable 11 (FIG. Fig. 1 ).

This is followed within the same work cycle at the same ejection station 10, the next step accordingly Fig. 5 at. Before this will be discussed in more detail, is first on Fig. 4 referenced, in which an ejector pin 23 after the Fig. 2, 3rd enlarged and shown schematically in longitudinal section. To form the blow channel 22 already described above, the ejector pin 23 is formed as a hollow and frontally closed-up tube, in the peripheral wall of the blowout slots 24 are formed. Alternatively or additionally, blow-out openings or slots can also be formed in the upper cover wall. The blow-out slots 24 have slot axes 25 which, relative to the longitudinal direction and the radial direction of the respective blow duct 22, extend to the suction device 16 (FIG. Fig. 2, 3rd . 5, 6 ) are inclined. When the overpressure source 28 (FIG. Fig. 2, 3rd . 5, 6 ) forms in the blast passage 22 from a blast of air, which according to arrows 40 through the blow-out slots 24 the slot axes 25 following emerges with radial and axial direction component.

After the ejection process of the capsules 14 as shown by Fig. 3 Now, the suction head 17 from his in the Fig. 2, 3rd shown passive ejection position in an active suction position according to the illustration Fig. 5 pivoted. In this active suction position, the suction openings 20 are in register with the respective receiving pockets 18 and the optional intermediate channel sections 38. As a result, the suction openings 20 are no longer covered by the sealing surface 26, but only sealed around the outside. The negative pressure generated by the negative pressure source 27 now forms a gas or air flow in the collecting channel 34 and in the suction channels 19, which continues through the suction channels 20 through the optional channel sections 38 and the receiving pockets 18 therethrough. Powder or dust residues or other contaminants that have settled in the area of the receiving pockets 18 are thereby sucked off.

After the ejection of the capsules 14 (FIG. Fig. 3 ) now the ejection pins 23 moved upward with the blow channels 22 formed therein in a retraction movement back to the rest position Fig. 2 method. Already in the in Fig. 5 shown upper ejection position, but with active suction device 16 after Fig. 5 can now the Blowout 21 are put into operation. The receiving pockets 18 of the capsule receptacle 15, in particular in the region of their peripheral walls, are actively blown out with compressed air or other pressurized gases via the blow ducts 22 formed in the ejection pins 23 and through the blowout slots 24 simultaneously with the suction described above Dust or other contaminants cleaned. The blow-off stream with the entrained and detached contaminant particles is sucked directly through the active suction device 16.

Fig. 6 shows the arrangement after Fig. 5 during the retraction movement of the ejector pins 23, with the ejector pins 23 in an intermediate position between the upper ejection position Fig. 5 and the lower rest position after Fig. 2 are shown. During the retraction movement, both the suction device 16 and the blow-out device 21 are active. The latter can be provided over the entire Rückzugweg. However, it may also be expedient to activate the suction device 16 and / or the blow-out device 21 only over part of the said withdrawal path. Another possibility is to keep the suction device 16 and the blow-out device 21 in operation over a period of time that lasts the same length. As long as it is ensured that the blow-out 21 is only active when the suction device 16 is active, the period of the blow-out may also be shorter than the period of suction.

Based on the condition Fig. 6 the ejector pins 23 now move completely back to their rest position Fig. 2 pulled while the suction head 17 back to its passive ejection position Fig. 2 is pivoted. The above-described cycle of process steps for ejecting the capsules 14 and cleaning the capsule holder 15 is now complete. By a clocked rotary motion of the turntable 11 ( Fig. 1 ) is now the emptied and cleaned capsule receptacle 15 to the next processing station, here to the first insertion and separation station 1 ( Fig. 1 ), while a subsequent capsule receptacle 15 with capsules 14 retained therein for re-ejection Suction process of the ejection station 10 after the Fig. 1 to 6 is supplied. Here again starts the above-described cycle of process steps.

Claims (12)

1. Capsule filling device for filling capsules (14) with a filling material, comprising a rotary table (11) with capsule receiving areas (15) and also fixed processing stations arranged around the rotary table (11), of which at least one processing station is an ejection station (9, 10) for ejecting the filled capsules (14) from the capsule receiving area (15),
   characterised in that the ejection station (10) is equipped with a suction means (16), wherein the suction means (16) comprises a movable suction head (17) which can be moved back and forth between a passive ejection position and an active suction position, wherein the suction head (17) in its passive ejection position releases the capsule receiving area (15) for the ejection of the capsules (14), and wherein the suction head (17) in its active suction position lies covering the capsule receiving area (15) to purify the capsule receiving area (15) by suction.
2. Capsule filling device according to claim 1,
   characterised in that the suction head (17) is formed as a pivotable ejection flap for guiding the ejected capsules (14) in the passive ejection position.
3. Capsule filling device according to claim 1 or 2,
   characterised in that the capsule receiving area (15) has individual receiving pockets (18) for each capsule (14), and a plurality of suction channels (19), each with a suction opening (20) for each receiving pocket (18), are formed in the suction head (17).
4. Capsule filling device according to claim 3,
   characterised in that the receiving pockets (18) are arranged in pairs in two rows in the capsule receiving area (15) and the suction channels (19) are branched off in a Y shape with pairs of suction openings (20) for each pair of receiving pockets (18).
5. Capsule filling device according to one of claims 1 to 4,
   characterised in that the ejection station (9, 10) in addition to the suction means (16) also has a blow-out device (21) with blowing channels (22) purifying the capsule receiving area (15) through a blow-out action.
6. Capsule filling device according to claim 5,
   characterised in that the ejection station (9, 10) has ejection pins (23) to eject the filled capsules (14) from the capsule receiving area (15), and the blowing channels (22) are formed in the ejection pins (23).
7. Capsule filling device according to claim 5 or 6,
   characterised in that the blowing channel (22) is formed by a hollow tube closed at its end face, in the peripheral wall of which tube blow-out slots (24) are formed.
8. Capsule filling device according to claim 7,
   characterised in that the blow-out slots (24) have slot axes (25) which are inclined towards the suction means (16) with respect to the longitudinal direction and the radial direction of the respective blowing channel (22).
9. Capsule filling device according to one of claims 1 to 8,
   characterised in that the suction head (17) in its passive ejection position lies against a sealing surface (26) so that one or more suction channels (19) formed in the suction head (17) are sealed with respect to flow.
10. Method for operating a capsule filling device according to one of claims 1 to 9, characterised by a cycle of the following method steps carried out in the ejection station (10):

    - the capsule receiving area (15) taking along capsules is moved by means of the rotary table (11) to the ejection station (10);

    - in the ejection station (10) the filled capsules (14) are ejected from the capsule receiving area (15) while the suction head (17) of the suction means (16) is in a passive ejection position releasing the capsule receiving area (15);

    - subsequently the suction head (17) is moved from its passive ejection position into its active suction position and the capsule receiving area (15) is thus purified by suction;

    - subsequently by means of rotation of the rotary table the emptied and purified capsule receiving area (15) is moved to the processing station while a subsequent capsule receiving area (15) with capsules is fed to the ejection station (10) for renewed ejection and suction process;

    - the suction head (17) is moved from its active suction position back into its passive ejection position.
11. Method according to claim 10,
    characterised in that the ejection pins (23) are moved from a position of rest for ejection of the filled capsules (14) into the capsule receiving area (15), and in the case of a contrary withdrawal movement and simultaneously active suction means (16) a purifying blow-out of the capsule receiving area (15) is carried out by means of the ejection pins (23).
12. Method according to claim 11,
    characterised in that the suction head (17) lies in its passive ejection position against a sealing surface (26) such that one or more suction channels (19) formed in the suction head (17) are sealed against flow, in the active suction position the one or more suction channels (19) are released by the sealing surface (26) and an under-pressure source (27) of the suction means (16) is active during the whole cycle.

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