Sealing group for a machine for making pods with extraction products

Abstract

A sealing group for sealing single packages enclosing products lined up within a tubular packaging strip advancing in a forward-advancing direction. The group includes first and second sealing devices positioned in succession along the direction to seal the strip; the first and second sealing devices includes, respectively, a first and second pairs of sealing heads operated by a kinematic device to synchronize movement so that each pair cyclically performs a sealing step in which the sealing heads move together for sealing and, simultaneously, advance along the direction to drag the strip in the direction during the sealing, and a positioning step in which the sealing heads are apart and move back along a direction opposite to the direction. The kinematic devices are synchronized so that at least one of the first and second pairs is in the sealing step to perform a continuous advancement of the strip.

Description

TECHNICAL FIELD

[0001] This invention relates to a sealing group for machines for making pods with extraction products.BACKGROUND ART

[0002] Currently, in the market for extraction products, such as coffee, barley coffee, tea and camomile, the so-called single-dose pods are also used for making the extracted product.

[0003] These pods which can be used for single use infusion comprise two pieces of filter material placed one over the other and sealed together to enclose, centrally, the dose of product in a, usually, circular shape.

[0004] One of the prior art machines that produce and package these pods, which operate with alternating motion, that is to say, step by step, comprises:

[0005] a station for feeding a first continuous strip of filter material;

[0006] a station for forming (pre-forming), on the first strip, a succession of circular impressions;

[0007] a station for dosing and feeding a dose of product inside each impression made on the first strip;

[0008] a station for feeding a second continuous strip of filter material configured to be positioned on the first strip provided with doses of product;

[0009] a station for joining, by sealing, the first and second continuous strips of filter material;

[0010] a station for cutting two strips of filter material to form, at least partly, individual pods;

[0011] a station for evacuating / receiving the single pods from a horizontal feed line of the strips;

[0012] a station for packaging the individual pods in a piece of wrapping film wrapped and closed on the pod.

[0013] The evacuation / receiving station and the packaging station, which are of particular interest in this description, are interconnected so as to be able to move the pods away from the pod forming line and position the individual pods in the piece of overwrapping film which will then be sealed.

[0014] The two above-mentioned evacuation / receiving and packaging stations comprise:

[0015] an ejection element for the pod configured to detach the pod from the excessive part (waste) of the continuous strips of filter material and to direct the pods (in a direction transversal to and under the surface of arrival of the continuous strips) towards

[0016] a rotary wheel or drum designed to receive and rotate each pod by a predetermined angle which is able to present the pod at

[0017] a gripper configured to pick up the single pod, rotating it by a right angle and positioning it, by vertical falling, in a sheet of overwrapping film folded into a “C” shape;

[0018] a sealing element designed to close the wrapping film and form the single package with pod.

[0019] The machine described above, although of good reliability, has shown technical limitations due to its reduced productivity.

[0020] In particular, all the operating stations forming the machine work in an alternating or stepwise fashion so as to feed the pods, moved along a feed line, in a number such that they can be correctly handled by the receiving and packaging stations described above, which are also moved in an alternating fashion.

[0021] In order to increase productivity, for example, the pod feed lines might be doubled in such a way as to present two pods placed side by side simultaneously for evacuation and packaging.

[0022] However, that solution would have required a complete doubling of the components of the evacuation and packaging stations.

[0023] This increase in the components of the evacuation and packaging stations would have resulted in an increase in the volumes and costs of the machine which could not be offset with the increase in productivity of the machine.Aim of the Invention

[0024] The aim of the invention is to provide a sealing group for a machine for making pods with extraction products which overcomes the above-mentioned drawbacks of the prior art.

[0025] In particular, the aim of the invention is to provide a sealing group and a machine for making pods with extraction products which are capable of maintaining reduced overall dimensions but increasing the productivity of the machine.

[0026] A further aim of the invention is to provide a machine for making pods with extraction products which is structured in such a way as to make the operating line extremely flexible according to the production requirements.

[0027] Said aims are fully achieved by the sealing group and by the machine for making pods with extraction products according to the invention, as characterised in the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The features of the machine will become more apparent from the following detailed description of a preferred, non-limiting embodiment of it, illustrated by way of example in the accompanying drawings, in which:

[0029] FIG. 1 is a schematic side view of a machine for making pods with extraction products in which the sealing group according to this invention is applied;

[0030] FIGS. 2 to 6 show the sealing group according to the invention in corresponding operating steps; FIG. 2 is a perspective view and FIGS. 4 to 7 are front views;

[0031] FIGS. 7 to 9 show the operating screen of sealing heads of the sealing group of FIGS. 2 to 6;

[0032] FIG. 10 is a rear perspective view of the kinematic mechanisms of the sealing group;

[0033] FIGS. 11 and 12 are both front views of the sealing group in two different configurations of the sealing heads to reach a cleaning position of the heads.DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0034] With reference to the accompanying drawings, in particular FIG. 1 and from 3 to 9, the sealing group according to the invention, labelled 100 in its entirety, is used for portioning individual packages C having a predetermined number of products 1 lined up in a tubular strip 2 of packaging feeding along a forward-advancing direction A.

[0035] As described in more detail below, this sealing group 100 can be applied in a machine 101 for making pods with extraction food products (shown in its entirety in FIG. 1).

[0036] The group 100 comprises a first sealing device 3 configured for sealing portions of the tubular strip 2 of packaging.

[0037] The first sealing device 3 is positioned along the forward-advancing direction A and comprises a first pair of sealing heads 5,

[0038] As illustrated, the sealing group 100 also comprises a second sealing device 4 positioned along the forward-advancing direction A and comprising a second pair of sealing heads 6.

[0039] The first 5 and the second 6 pair of sealing heads are driven by a respective kinematic device 7, 8 configured to synchronise the movement of the first 5 and the second 6 pair of sealing heads in such a way that each pair 5, 6 of sealing heads cyclically performs:

[0040] a sealing step wherein the sealing heads of the pair 5 or 6 are close to each other for sealing the tubular packaging strip 2 and, simultaneously, feed along the forward-advancing direction A in such a way as to drag the tubular packaging strip 2 along the forward-advancing direction A during the sealing step, and

[0041] a positioning step wherein the sealing heads of the pair 5 or 6 are spaced apart from each other and move backwards along a direction opposite to the forward-advancing direction A.

[0042] Again, as illustrated, the respective kinematic control devices 7, 8 are synchronised in such a way that at least one of the first or second pairs of sealing heads 5, 6 is (always) in the sealing step for continuously feeding the tubular packaging strip 2.

[0043] In other words, the two pairs of sealing heads are configured to obtain, in a synchronised fashion with each other, a sealing of the package of products together with a feeding of the tubular packaging strip (as clearly shown in FIGS. 7 to 9).

[0044] In light of this, each kinematic device 7, 8 is controlled by a control unit 9 (illustrated in FIG. 11 with a block) configured to command one of between the first or second pair 5 or 6 of sealing heads to perform the sealing step, while the other pair of the first and second pair 6 or 5 of sealing heads performs the positioning step, so as to maintain a continuous dragging of the tubular packaging strip 2.

[0045] In light of this, each kinematic device 7, 8 comprises a cinematic group driven by a driving mechanism 14 via a motorized shaft 10 to move the respective pair 5, 6 of sealing heads with a roto-translational movement.

[0046] As illustrated, each kinematic device 7, 8 comprises for each sealing head of each pair 5, 6 of sealing heads:

[0047] the motorized shaft 10 (connected to the control unit 9);

[0048] two first lever mechanisms 11 forming a respective four-bar linkage mechanism between the motorized shaft 10 and the respective sealing head allowing a roto-translational movement of the sealing head;

[0049] a second lever mechanism 12 interposed between the first two lever mechanisms 11 kinematically linked between the respective sealing head and the motorized shaft 10 to allow the thrust of the respective sealing head onto the tubular packaging strip 2 during the sealing step;

[0050] a plurality of cam elements 13 arranged between the driving mechanism 14 and the motorized shaft 10 allowing synchronized movement of the two first 11 and the second 12 lever mechanisms.

[0051] Basically, each sealing head is moved by the first lever mechanisms 11 in their roto-translational movement, whilst the second lever mechanism 12 allows the correct pressure to be obtained on the tubular packaging strip 2.

[0052] Each cam element 13 is illustrated in FIG. 11 and may comprise cam profiles keyed to the respective driving mechanism 14 and in contact with respective cam follower rollers connected to the first 11 and second 12 lever mechanisms by the motorized shaft 10.

[0053] As illustrated in FIGS. 2 to 9, the kinematic devices 7, 8 described above of each pair 5, 6 of sealing heads, during the sealing step, are commanded to bring one of the first or second pairs 5 or 6 of sealing heads from a distant position to a close position for sealing the tubular packaging strip 2 and contemporarily move the tubular packaging strip 2 along the forward-advancing direction A (see FIGS. 8 and 9).

[0054] In other words, following the diagram in FIGS. 2 to 9 and the arrows F5 and F6 illustrating the trajectories shows:

[0055] a first pair of heads 5 has just finished a package C and is moving away from the strip 2, whilst the second pair of sealing heads 6 closes on the strip 2 and starts both the sealing and the dragging of the strip (FIGS. 3 and 7) of the relative package;

[0056] the first pair of sealing heads 5 moves back (relative to the forward-advancing direction A) to reach a new package to be formed, but being overtaken by a package C1 to be formed which will be performed by the second pair of sealing heads 6 which has finished producing the relative package C with the dragging of the strip 2 (FIGS. 2, 4 and 8);

[0057] the second pair of heads 6 moves back (relative to the forward-advancing direction A) to reach a new package to be formed, but being overtaken by the package C formed by the first pair of sealing heads 5 which has finished producing the relative package C with dragging of the strip 2 (FIGS. 5, 6 and 9).

[0058] It should be noted that the first 3 and the second 4 sealing devices are configured for sealing the tubular packaging strip 2 on three sides forming a U profile.

[0059] As illustrated in FIG. 6, the group 100 comprises a reinforcement frame 15 associated with each motorized shaft 10 and configured to stiffen the first and the second pairs 5 and 6 of sealing heads.

[0060] The frame 15 has the shape of a bridge closed in a loop and protrudes outside the operating zones for passage of the tubular packaging strips 2.

[0061] As illustrated in FIGS. 10 to 12, the sealing group 100 further comprises a clutch group 16 configured to temporary disengage the kinematic devices 7, 8 of the pairs 5, 6 of sealing heads from the respective motorized shaft 10, allowing the sealing heads to be freely rotated in order to put them into a cleaning / maintenance position to allow cleaning and maintenance of the sealing heads.

[0062] In light of this, the clutch group 16 comprises a control lever 17 acting on the kinematic devices 7, 8 by means of a series of pulleys 18 keyed by a kinematic mechanism with the kinematic devices 7, 8 and a motion transmission belt 19 connected in a loop on the pulleys 18.

[0063] The control lever 17 can rotate about an axis X to allow, synchronously, a movement of the first and second pairs 5, 6 of sealing heads in the above-mentioned cleaning / maintenance position.

[0064] As shown in FIGS. 5, 11 and 12, the sealing heads may be stopped in a fixed sealing position and, subsequently, by rotating the lever 17, move firstly to a raised position and with the two heads of each pair only partly facing each other (that is to say, offset), and then to the cleaning position.

[0065] The lever 17 acts, through the pulleys 18 and the transmission belt 19, on corresponding cam means 28 dedicated to this function and connected to the respective motorized shafts 10.

[0066] This invention provides a machine 101 for producing and packaging pods (with extraction products) equipped with the sealing group 100 (see FIG. 1).

[0067] The machine 101 may be used for making pods for extraction products such as, but not restricted to, coffee, barley coffee, tea, camomile.

[0068] These single-use pods comprise two pieces of filter material placed one over the other and sealed together to enclose, centrally, the dose of product in a, usually, circular shape.

[0069] The machine 101 extends along a relative advancing line and comprises a sequence in substantial succession of operating stations.

[0070] The machine 101 comprises a first feeding station 20 (having a feed reel) configured for feeding a first continuous strip S1 (of filter material).

[0071] The machine 101 comprises a dosing station 21 configured to dose a product on the first continuous strip S1.

[0072] Moreover, the machine 101 comprises a second feeding station 22 (having a feed reel) configured to feed a second continuous strip S2 (of filter material) to be positioned on the first continuous strip S1 having the doses of product.

[0073] The machine 101 also comprises a joining station 23 configured to seal (usually hot) the first S1 and second S2 continuous strips together to form a continuous band N comprising a plurality of pods arranged along a plurality of adjacent lines advancing on an advancement plane P.

[0074] The machine 101 also comprises a cutting station 24 configured to cut individual pods 1 (comprising a pair of rotary knives) from the continuous band N.

[0075] The machine 101 also comprises an inserting station 25 configured to insert the pods within the tubular packaging strip 2.

[0076] The machine 101 comprises a sealing station 26 configured to portion single packages C having a predefined number of pods.

[0077] The machine 101 also comprises a cutting station 27, arranged downstream of the sealing station 26, and configured to separate the portioned single packages C from each other.

[0078] As illustrated, the sealing station 26 comprises the sealing group 100 illustrated up to now.

[0079] According to a non-limiting example embodiment not fully illustrated, the above-mentioned inserting station 25 may comprise a plurality of gripper units rotating continuously about an axis of rotation and along a plane parallel to the advancement plane P of the products 1.

[0080] Each gripper unit is configured for gripping and releasing a single pod 1.

[0081] The tubular packaging strip 2 is folded along a folding edge in such a way as to superpose two portions of packaging strip forming an opening opposite the folding line and positioned facing the inserting station 25.

[0082] The tubular packaging strip 2 is advanced continuously by advancement means (pairs of rollers) along a plane coplanar with the plane of rotation of the plurality of gripper units and in phase with the above-mentioned pairs 5 and 6 of sealing heads.

[0083] The gripper units are configured to grip substantially simultaneously a corresponding plurality of individual products (pods) 1 placed side by side on a common line of products feeding out of the cutting station 27 and to release them, after an angular rotation of the gripper units, in the tubular packaging strip 2 between the two superposed portions of the packaging strip 2, in succession and according to a predetermined sequence.

[0084] In other words, the groups of products 1 obtained at the outfeed from the cutting station (in this case, a row of three) are picked up almost simultaneously by the grippers present (movable continuously) and moved directly inside the packaging strip which is also advanced continuously up to the sealing group (which also operates continuously). Whilst all the preceding stations up to the cutting station operate with stepping or discontinuous motion.

[0085] This “mixed” solution allows a band of pods to be formed having multiple rows which are then picked up quickly and precisely by the gripper units with consequent positioning inside the packaging strip positioned, as described below, alongside the cutting station and coplanar with the rotation plane of the gripper units.

[0086] The strip 2 advances continuously up to the sealing group 100 which, as mentioned, allows the packages C to be formed and to drag the strip 2 continuously up to the cutting of the packages.

[0087] This invention also provides a method for sealing single portions of packages having a predetermined number of products.

[0088] The method comprises the steps of:

[0089] preparing a tubular packaging strip 2 containing a line of adjacent products 1

[0090] advancing the tubular packaging strip 2 along a forward-advancing direction A;

[0091] sealing the tubular packaging strip 2 by means of a first 3 and a second 4 sealing device arranged along the forward-advancing direction A; the first 3 and the second 4 sealing device sealing respective alternate portions of the tubular packaging strip 2, the sealing being made with a simultaneous dragging of the tubular packaging strip 2 along the forward-advancing direction A;

[0092] synchronizing the two sealing devices 3 and 4 so that at least one of between the first and second sealing devices 3 or 4 performs the sealing step and simultaneously the dragging step to ensure a continuous advancement of the tubular packaging strip 2 along the forward-advancing direction A.

[0093] It should be noted that, while one of between the first and second sealing devices 3 or 4 seals and drags the tubular packaging strip (2), the other sealing device 4 or 3 moves back along a direction opposite to the forward-advancing direction A.

[0094] In light of this, the first and second sealing devices 3 or 4 seal the tubular packaging strip 2 on three sides forming a U profile.

[0095] Again, in light of this, the tubular strip 2 is obtained by folding a packaging strip along a folding line forming a continuous U-shaped pocket by overlapping two portions of the packaging strip, leaving an opening opposite the folding line.

[0096] As already mentioned, the products 1 are pods of food material.

Claims

1. A sealing group for sealing single packages enclosing a predefined number of products lined up within a tubular packaging strip advancing in a forward-advancing direction, said group comprising a first sealing device configured to seal portions of said tubular packaging strip, wherein said first sealing device is arranged along said forward-advancing direction and comprises a first pair of sealing heads, characterized in that said sealing group further comprises a second sealing device arranged along said forward-advancing direction and comprising a second pair of sealing heads, said first and second pairs of sealing heads being operated by a respective kinematic device configured to synchronize movement of the first pair and second pair of sealing heads so that each pair of sealing heads cyclically performs a sealing step in which the sealing heads of the pair are close to each other for sealing the tubular packaging strip and, simultaneously, advance in said forward-advancing direction so as to drag the tubular packaging strip in the forward-advancing direction during the sealing step, and a positioning step in which the sealing heads of the pair are distant from each other and move back along a direction opposite to the forward-advancing direction and in that said respective kinematic devices are synchronized so that at least one of said first and second pairs of sealing heads is in the sealing step to perform a continuous advancement of the tubular packaging strip.

2. The sealing group according to claim 1, wherein each kinematic device is controlled by a control unit configured to command one of between the first or second pair of sealing heads to perform the sealing step, while the other pair of said first and second pair of sealing heads performs the positioning step, so as to maintain a continuous dragging of the tubular packaging strip.

3. The sealing group according to claim 1, wherein each kinematic device comprises a cinematic group driven by a driving mechanism via a motorized shaft to move the respective pair of sealing heads with a roto-translational movement.

4. The sealing group according to claim 3, wherein each kinematic device comprises for each sealing head of each pair of sealing heads:the motorized shaft;two first lever mechanisms forming a respective four-bar linkage mechanism between the motorized shaft and the respective sealing head allowing a roto-translational movement of the sealing head;a second lever mechanism interposed between the first two lever mechanisms kinematically linked between the respective sealing head and the motorized shaft allowing thrust of the respective sealing head onto the tubular packaging strip during the sealing step;a plurality of cam elements arranged between the driving mechanism and the motorized shaft allowing synchronized movement of the two first and the second lever mechanisms.

5. The sealing group according to claim 1, wherein the kinematic devices of each pair of sealing heads, during the sealing step, are commanded to bring one of the first and second pairs of sealing heads from a distant position to a close position for sealing the tubular packaging strip and contemporarily move the tubular packaging strip along the forward-advancing direction.

6. The sealing group according to claim 3, comprising a reinforcement frame associated to each motorized shaft and configured to stiffen the first and second pairs of sealing heads.

7. The sealing group according to claim 3, further comprising a clutch group configured to temporary disengage the kinematic devices of the pairs of sealing heads from the respective motorized shaft, allowing the sealing heads to be freely rotated in order to put them into a cleaning / maintenance position to allow cleaning or maintenance of the sealing heads.

8. The sealing group according to claim 7, wherein the clutch group comprises a commanding lever acting on the kinematic devices by means of a series of pulleys kinematically keyed with the kinematic devices and a transmission belt linked in a ring configuration to the pulleys, the commanding lever being rotatable around an axis to allow, synchronously, moving of the first and second pairs of sealing heads into said cleaning / maintenance position.

9. The sealing group according to claim 1, wherein said first and second sealing devices are configured to seal the tubular packaging strip on three sides forming a U profile.

10. A machine for producing and packaging pods comprising:a first feeding station configured to feed a first continuous strip;a dosing station configured to dose a product on the first continuous strip;a second feeding station configured to feed a second continuous strip to be disposed on top of the first continuous strip having the doses of product;a joining station configured to seal the first and second continuous strips together to form a continuous band comprising a plurality of pods arranged along a plurality of adjacent lines advancing on an advancement plane;a cutting station configured to cut single pods from the continuous band;an inserting station configured to insert the pods within a tubular packaging strip;a sealing station configured to portion single packages having a predefined number of pods;a cutting station, arranged downstream of the sealing station, and configured to separate the portioned single packages from each other.characterized in that the sealing station comprises a sealing group according to claim 1.

11. A method for sealing single portions of packages having a predefined number of products comprising the steps of:preparing a tubular packaging strip containing a line of adjacent products;advancing said tubular packaging strip along a forward-advancing direction;sealing said tubular packaging strip by means of a first and a second sealing device arranged along said forward-advancing direction, said first and second sealing device sealing respective alternate portions of said tubular packaging strip, said sealing being made with a simultaneous dragging of said tubular packaging strip along said forward-advancing direction;synchronizing the two sealing devices so that at least one of between the first and second sealing devices performs the sealing step and simultaneously the dragging step to ensure a continuous advancement of the tubular packaging strip along said forward-advancing direction.

12. The method according to claim 11, wherein while one of between the first and second sealing devices seals and drags the tubular packaging strip, the other sealing device moves back along a direction opposite to the forward-advancing direction.

13. The method according to claim 11, wherein said first and second sealing devices seal the tubular packaging strip on three sides forming a U profile.

14. The method according to claim 11, wherein the tubular strip is obtained by folding a packaging strip along a folding line forming a continuous U-shaped pocket by overlapping two portions of the packaging strip, leaving an opening opposite the folding line.

15. The method according to claim 11, wherein said products are pods of food material.

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