CN113853341A

CN113853341A - Packaging assembly for forming and sealing a plurality of packages containing pourable products and method for forming and sealing a plurality of packages

Info

Publication number: CN113853341A
Application number: CN202080035591.XA
Authority: CN
Inventors: 马西莫·普拉德利; 马西米利亚诺·巴尔比; 法布里齐奥·里蒙迪
Original assignee: Tetra Laval Holdings and Finance SA
Current assignee: Tetra Laval Holdings and Finance SA
Priority date: 2019-07-01
Filing date: 2020-06-16
Publication date: 2021-12-28
Also published as: US20220363418A1; EP3760548B1; JP2022537627A; EP3760548A1; WO2021001144A1

Abstract

Described is a packaging assembly (1; 1') configured to form and seal a plurality of packages (3) containing pourable products, starting from a tube (2) of packaging material; the packaging assembly (1; 1') Comprising: a pair of annular rails (6), between which the tube (2) is fed in a linear advancing direction (A); and a pair of movable members (7; 7'), each of which is movable is coupled to a corresponding track (6) and is cyclically movable along the track (6); each movable member (7; 7') movably carries a corresponding forming member (20; 20') which forms The member (20; 20') is linearly movable towards the tube (2), transverse to the advancing direction (A), to cyclically come into contact with the continuous tube portion (13) in order to form at least one portion of the respective package (3). Corresponding packaging parts; each forming member (20; 20') comprises a movable part (21; 21') which can be tilted with respect to the advancing direction (A) to sequentially The inclination of the tube portion (13) with respect to the advancing direction (A) is controlled.

Description

Packaging assembly for forming and sealing a plurality of packages containing pourable products and method for forming and sealing a plurality of packages

Technical Field

The present invention relates to a packaging assembly configured to form and seal a plurality of packages containing a pourable product, in particular a pourable food product.

The present invention also relates to a method for forming and sealing a plurality of packages containing a pourable product, in particular a pourable food product.

Background

It is well known that many pourable food products, such as fruit juice, UHT (ultra high temperature treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package of pourable food products known as Tetra Brik Aseptic (registered trade mark) which is made by folding and sealing a laminated web of packaging material. The packaging material has a multilayer structure comprising a base layer, for example made of paper, covered on both sides with layers of heat-seal plastic material (for example polyethylene). In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material, for example aluminium foil, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

Such packages are typically produced in fully automated packaging assemblies in which a continuous tube is formed from a web of packaging material fed to such packaging assemblies. The web of packaging material is sterilized in the packaging assembly, for example by applying a chemical sterilization agent, for example a hydrogen peroxide solution, which chemical sterilization agent is removed from the surface of the packaging material once sterilization has been completed, for example by evaporation by heating. The web thus sterilized is then maintained in a closed, sterile environment and is folded and sealed longitudinally to form a tube which is fed in a vertical advancing direction.

To complete the forming operation, the tube is filled with the sterilized food product from above and sealed along equally spaced cross sections, followed by cutting.

A pillow pack (pillow pack) is thus obtained, having a longitudinal sealing band, a top transverse sealing band and a bottom transverse sealing band.

It is known to use packaging assemblies comprising a plurality of carts movable independently of each other on a track and configured to form and seal the above-described pillow packs.

In this case, a typical packaging assembly comprises two conveyors provided with the following:

-a first track and a second track defining a first annular path and a second annular path, respectively, and arranged on respective opposite lateral sides of the tube;

-a plurality of first carts movably coupled to the first track and configured to advance along a first path; and

a plurality of second carts movably coupled to the second track and configured to propel along a second path.

The first carts are movable (controllable) independently of each other along a first path, and the second carts are movable (controllable) independently of each other along a second path.

To achieve independent movement of the cart, a linear motor is typically used.

Thus, each of the first and second tracks is equipped with a respective individually energizable solenoid, e.g. an electrical coil, while each of the first and second carts is equipped with a permanent magnet. The resulting linear motors are configured to independently control the propulsion of the first and second carts along the first and second paths, respectively, in a known manner.

It is known that the first and second trolleys are configured to cooperate cyclically in pairs with each other and with the tube so as to form and seal respective tube portions of the tube, so as to produce the above-mentioned pillow packs.

Although functionally effective, the known packaging assemblies still remain to be further improved. In particular, when handling (i.e. forming and sealing) packages configured to be folded to form packages having a slanted (non-horizontal) top wall [ e.g. tetra pak (registered trademark) peak packages ], it is desirable to optimize the known packaging assembly.

Disclosure of Invention

It is therefore an object of the present invention to provide a packaging assembly designed to at least meet the above-mentioned need in a simple and low cost manner.

This object is achieved by a package assembly according to claim 1.

Another object of the present invention is to provide a method for forming and sealing a plurality of packages containing a pourable product, designed to at least meet the above-mentioned need in a simple and low-cost manner.

This object is achieved by a method for forming and sealing a plurality of packages as claimed in claim 14.

Drawings

Two preferred, non-limiting embodiments of the present invention will be described, by way of example, with reference to the accompanying drawings, in which:

figure 1 is a schematic front view of a package assembly for forming a plurality of sealed packages according to the present invention with some components removed for clarity;

fig. 2 is a perspective view of a portion of the package assembly of fig. 1 with some components removed for clarity;

fig. 3 is an enlarged exploded perspective view of the cart of the package assembly of fig. 1 with some components removed for clarity;

fig. 4 is an enlarged perspective cut-away view of two cooperating carts of the packaging assembly of fig. 1 with some components removed for clarity;

fig. 5a and 5b are two enlarged schematic partially cut-away side views of the two co-operating carts of fig. 4 in two different operating conditions, with parts removed for clarity;

fig. 6 is an enlarged perspective view of the cart of the package assembly according to the second preferred embodiment of the present invention with some components removed for clarity;

figure 7a is a perspective view of a package obtained by folding a package formed and sealed by a package assembly according to the present invention; and

fig. 7b is a side view of the package of fig. 7a, wherein the bottom flap of the package has been separated from the bottom wall of the package and the top flap of the package has been separated from the side wall of the package to better show that the package comprises a top sealing band that is not aligned with the bottom sealing band.

Detailed Description

With reference to fig. 1, numeral 1 generally designates a packaging assembly configured to form and seal, starting from a tube 2 of packaging material, a plurality of packages 3 containing pourable products, preferably pourable food products.

The packaging material has a multilayer structure (not shown) and comprises a layer of fibrous material (e.g. paper) covered on both sides by respective layers of heat-seal plastic material (e.g. polyethylene).

In the case of aseptic packages 3 for long-storage products, such as UHT milk, the packaging material also comprises layers of gas and light barrier material, such as aluminum foil or ethylene vinyl alcohol (EVOH) film, which are superimposed on a layer of heat-seal plastic material eventually forming the inner face of package 3 contacting the pourable product.

The tube 2 is formed in a known manner by longitudinally folding and sealing a web (not shown) of packaging material. The tube 2 is then filled from above with the pourable product through a duct (not shown) and fed through the packaging assembly 1 in a linear advancement direction a. In detail, the tube 2 extends along a rectilinear longitudinal (in particular vertical) axis X parallel to the direction a.

Two horizontal linear directions B, C that are orthogonal to each other and to direction a (fig. 1) may also be identified.

The package assembly 1 comprises:

a pair of conveyors 4 arranged on respective lateral sides of tube 2, spaced apart from each other along direction B, and configured to cooperate with tube 2; and

an exit conveyor 10 arranged below the conveyor 4 staggered with respect to the axis X along the direction B.

As shown in particular in fig. 2, each conveyor 4 substantially comprises:

a box-shaped element 5 comprising an annular track 6, the annular track 6 being defined by two rails (rails) arranged on opposite lateral sides of the box-shaped element 5 spaced from each other in the direction C; and

a plurality of moving members, preferably carts 7, each movably coupled to a respective track 6 and being cyclically movable along the track 6.

In particular, each trolley 7 is configured to cyclically slide along the track 6 of the respective conveyor 4. In view of the above, in use, a plurality of carts 7 slide along each track 6.

To this end, each trolley 7 substantially comprises (fig. 2 and 3) a movable body 14, which movable body 4 extends parallel to direction C when coupled to a respective track 6, and is provided with a plurality of wheels 15 configured to movably engage respective tracks 6.

In particular, the carts 7 of one conveyor 4 are movable along the respective rails 6 independently of each other and independently of the carts 7 of the other conveyor 4.

For this purpose, each trolley 7 is provided with a magnetic part, in particular a permanent magnet device 11, and each conveyor 4 comprises a plurality of powered magnetic field generators, preferably electric coils 12, arranged in fixed positions inside the box-shaped element 5. The coils 12 are configured to magnetically couple with the permanent magnets 11 of each trolley 7 in order to control the movement of such trolley 7 along the respective track 6.

In fact, the permanent magnet device 11 and the coils 12 of each conveyor 4, i.e. the carts 7 and the respective tracks 6, define linear motors configured in a known manner to independently control the movement of the carts 7 along the respective tracks 6.

As a possible alternative, not shown, the tracks 6 of the two conveyors 4 may comprise a single track.

With reference to fig. 1, the two tracks 6 define respective annular paths P, Q, which are arranged on opposite sides of the axis X of the tube 2 with respect to the direction B. More specifically, path P, Q includes:

respective operating branches P1, Q1, preferably rectilinear, between which the tube 2 is fed and along which the trolley 7 cooperates with the tube 2; and

respective return branches P2, Q2 along which cart 7 is detached from tube 2.

According to the preferred embodiment shown, path P, Q is substantially elliptical.

In use, when sliding along the respective operating branch P1, Q1, each trolley 7 of one conveyor 4 cooperates with a corresponding trolley 7 of the other conveyor 4-i.e. the trolleys 7 cooperate mutually two by two-in such a way as to define a pair of trolleys 7 facing each other and cooperating with each other and with the tubes 2, while sliding along the operating branches P1, Q1.

In particular, each pair of carts 7 is configured to cooperate with tube 2 so as to form and seal one respective pillow pack 3 at a time cyclically, and to cut pillow packs 3 to separate pillow packs 3 from tube 2, as shown in fig. 1.

To this end, the main body 14 of each trolley 7 carries, on one side thereof, a forming unit 18 and a sealing unit 19, both forming unit 18 and sealing unit 19 being configured to cooperate with the tube 2 along respective operating branches P1, Q1.

In particular, as better described hereinafter, forming units 18 are configured to cooperate respectively with tube portions 13 of tube 2 to form at least corresponding package portions, more particularly corresponding packages 3.

To this end, each forming unit 18 is carried in a movable manner by the respective trolley 7, preferably mounted on the respective trolley 7, and comprises a respective forming member, preferably a half-shell 20, having a C-shaped cross section and comprising a main wall 21 and a pair of lateral fins 22. In the embodiment shown, the flap 22 is movably coupled to the wall 21.

In detail, when the trolley moves along the operating branches P1, Q1, the tabs 22 protrude from the opposite lateral edges of the wall 21 with respect to the direction C and are hinged to these edges.

In use, half-shells 20 of each forming unit 18 are configured to cooperate in sequential and cyclical contact with tube portions 13, so as to form at least the packaging portions of respective packages 3.

In more detail, each half-shell 20 is linearly movable transversely, in particular orthogonally, to direction a and to axis X, towards tube 2, i.e. towards tube portion 13 which half-shell 20 must form.

In particular, each trolley 7 comprises a movable element 57 carrying a respective half-shell 20, which movable element 57 is linearly movable transversely, in particular orthogonally, to direction a and to axis X.

In particular, the movable element 57 is linearly movable along the direction B.

The sealing unit 19 is configured to cooperate with the tube 2 to seal the tube portions 13 at a predetermined equidistant succession of cross sections crosswise to the direction a and lying on a sealing plane S parallel to the direction a and centred with respect to the tube 2, so as to form in each tube portion 13 in turn opposite top and

bottom sealing bands

3a, 3 b. In other words, the sealing plane S intersects the tube 2 axially and contains the axis X.

Furthermore, sealing unit 19 is configured to cooperate with tube 2 to cut such packages 3 at a cross section through top sealing band 3a and bottom sealing band 3b, in order to separate packages 3 from each other.

On one conveyor 4, each sealing unit 19 is mounted downstream of a corresponding forming unit 18 of the respective trolley 7 along a respective path P, Q and comprises a relative sealing device 17 and an extractable cutting element, for example a knife (not shown).

On the other conveyor 4, each sealing unit 19 is mounted downstream of a corresponding forming unit 18 of a respective cart 7 along a respective path P, Q, and comprises a sealing device 23 and a seat, not shown, suitable for receiving a knife of a corresponding sealing device 23 configured to cooperate with such a relative sealing device 17.

In the preferred embodiment shown, the sealing means 23 is an ultrasonic sealing means.

According to an alternative embodiment, not shown, the sealing means 23 are induction heating elements and the corresponding counter-sealing means 17 are made of an elastic material, which provides the necessary mechanical support to clamp the tube 2 to the required pressure during the sealing operation.

As shown in fig. 1, when the forming unit 18 and the sealing unit 19 are pushed by the respective cart 7 of each conveyor 4 along the respective operating branch P1, Q1, the respective half-shell 20, the sealing device 23 and the relative sealing device 17 move back and forth in direction B between:

a closed or operating position in which half-shells 20, sealing means 23 and counter-sealing means 17 cooperate with respective tube portions 13 to form, seal and cut respective packages 3; and

an open or idle position in which half-shell 20, sealing means 23 and counter-sealing means 17 are separated from tube 2 or from formed package 3.

In particular, when both half-shells 20 of the two respective forming units 18 of a pair of cooperating carts 7 are in the operative (closed) position, they define a substantially prismatic cavity and accordingly control the volume and shape of one respective package 3 being formed.

More specifically, when the half-shells 20 are in the operative (closed) position, their walls 21 are located on opposite sides of the respective tube portion 13 and contact the respective tube portion 13.

In this case, flaps 22 of each half-shell 20 are rotated about the respective hinges from a position in which they diverge from respective walls 21 to a position in which they are substantially orthogonal to walls 21, facing flaps 22 of the other half-shell 20 carried by the corresponding cart 7 of the same pair and contacting tube 2 to completely enclose respective tube portions 13 intended to form respective packages 3.

When counter-sealing device 17 and sealing device 23 of a pair of cooperating carts 7 are in the active (closed) position, they cooperate with each other to heat-seal tube 2 so as to form a top sealing band 3a and a bottom sealing band 3b of packages 3 transverse to direction a and axis X and lying on sealing plane S.

Then, the respective cutting element is extracted so as to cut packages 3 between top sealing band 3a (of one package) and bottom sealing band 3b (of the adjacent package) and separate the formed packages 3 from each other.

Conversely, when the half-shell 20, the counter-sealing means 17 and the sealing means 23 are in the idle (open) position, they are separated from the tube 2.

According to the embodiment shown, the above-mentioned cyclic movement of the half-shells 20 (walls 21 and fins 22), of the counter-sealing means 17, of the sealing means 23 and of the cutting elements from their idle position to their operating position is automated (in a manner known per se and not described in detail) by the cooperation between a cam assembly 24 (fig. 2, which is fixed with respect to the conveyor 4 and to the track 6) and a plurality of cam followers (partially shown in fig. 2) carried by each trolley 7.

In detail, according to this preferred embodiment, each of the wall 21, the flap 22, the sealing means 23, the cutting element and the counter-sealing means 17 carries at least one respective cam follower configured to cooperate in a sliding manner with a respective cam surface of the cam assembly 24.

In particular, each tab 22 forming a cell 18 carries a respective cam follower 25, which cam follower 25 is configured to cooperate in a sliding manner with a corresponding cam surface of a cam element 26 of the cam assembly 24.

In more detail, the cam followers 25 are configured to cooperate in sliding manner with the respective cam elements 26 to move transversely to the advancing direction a, while the trolley 7 moves, in use, along the operating branches P1, Q1.

In this particular embodiment, for each trolley 7, the cam follower 25 is mechanically connected (coupled) to the flap 22 by means of a lever mechanism 27 (fig. 3), this lever mechanism 27 being configured to drive, in a known manner, the rotation of the flap 22 about its hinge due to the interaction of the cam follower 25 with the cam element 26.

Preferably, the half-shells 20, the counter-sealing means 17, the sealing means 23 and the cutting elements are pushed back into their respective idle positions by means of springs (not shown) acting on the respective cam followers.

Outlet conveyor 10 is configured to receive pillow packs 3 and convey them towards a folding unit, not shown, in which packs 3 are folded into their final shape, so as to obtain respective packages 50 (one of which is shown in fig. 7 a).

It should be noted that fig. 7b shows pillow packs 3 which do not correspond to any step of the forming cycle. Fig. 7b shows only the package 50 with its flaps open and the top and

bottom sealing bands

3a, 3b raised (i.e. the package 50 is not completely folded).

In particular, as can be seen in fig. 7b, pillow pack 3 comprises a substantially prismatic main portion 51 having a longitudinal axis Y and delimited at its bottom end by a flat horizontal bottom wall 52 and at its top end by an inclined top wall 53.

The top sealing band 3a and the bottom sealing band 3b, formed in the above-described manner by the sealing unit 19, axially project from the inclined top wall 53 and the bottom wall 52, respectively.

More specifically, in a package 50 (fig. 7a) with a sloping top wall 53, for example a tetra pak (registered trademark) peak package, the bottom sealing band 3b is coaxial with the axis Y, while the top sealing band 3a is eccentric with respect to the axis Y.

In more detail, when the top sealing band 3a projects vertically from the inclined top wall 53, it is arranged offset with respect to the axis Y by a distance 55 (measured orthogonally to the axis Y), as can be seen in fig. 7 b.

Since, as mentioned above, the sealing unit 19 is configured to cooperate with the tube 2 to seal the tube portion 13 at a cross section lying on a sealing plane S centred with respect to the tube 2 and slightly rotated during the sealing operation, due to the arrangement of the top sealing band 3a on the inclined top wall 53 of the package 50, offset with respect to the axis Y so as to ensure the formation of the inclined top wall 53.

This rotation is imparted during the sealing operation thanks to a specific predetermined pattern of crease lines (known per se and not illustrated) provided on the packaging material and necessary for determining the formation of the packages 50 with the sloping top wall 53.

The forming unit 18, and in particular the half-shells 20, must therefore follow and control (i.e. drive) the above-mentioned rotation of the tube portions 13 in sequence during the sealing and forming of the packages 3. In fact, if rotation is not allowed, the tube portion 13 will be damaged due to the deformation caused by the fold imparted by the pattern of crease lines.

To this end, the wall 21 of each half-shell 20 can be inclined with respect to the direction a to control the inclination of the respective tube portion 13 with respect to the direction a.

In particular, each half-shell 20 can be tilted with respect to the respective movable element 57.

In more detail, half-shell 20 comprises a rear wall 56, which rear wall 56 is connected to a movable element 57 and movably carries wall 21-and fins 22 through this wall 21-and is linearly movable in direction B towards said tube 2. In particular, each rear wall 56 is arranged behind a respective wall 21 with respect to direction B.

Conveniently, each wall 21 may be inclined with respect to the corresponding rear wall 56, the rear wall 56 not being inclined but only moving linearly in direction B.

More specifically, the walls 21 of each pair of half-shells 20 can be inclined by an angle α with respect to the direction a and with respect to the rear wall 56 (fig. 5b), so as to drive the tube portion 13 with which it is cooperating by the same angle α.

In view of the above, wall 21 is both linearly movable in direction B, carried by rear wall 56, and inclined at an angle α with respect to direction a.

As can be seen in fig. 5b, since the flaps 22 are hinged to the wall 21, the flaps 22 may also be inclined with respect to the respective rear wall 56.

Thus, the wall 21 is configured to be inclined while the trolley 7 advances parallel to the direction a, in particular along the operating branches P1, Q1 of the annular path P, Q, respectively.

In this way, the inclination of the wall 21 by the angle α -i.e. of the tube portion 13-ensures that the half-shell 20 follows and controls the above-mentioned rotation of the tube portion 13 caused by the particular configuration of the crease lines thereof.

Furthermore, the above-described configuration ensures that the top sealing band 3a of each pack 50 is formed offset by a distance 55 with respect to the axis Y of the pack 50, without compromising the structural integrity of the pack 50.

To achieve the above-mentioned tilting, the packaging assembly 1 comprises actuator means configured to drive the tilting movement of each wall 21 and, consequently, of each tube portion 13.

According to this preferred embodiment, the actuator means comprise a cam follower 25 and a cam element 26.

For the sake of brevity, reference will be made below to a single cart 7 configured to form and seal respective tube portions 13.

However, all features described below for such carts 7 apply to all carts 7 movably coupled to the track 6 of the conveyor 4.

In detail, the trolley 7 comprises a pusher mechanism 28, to which pusher mechanism 28 the cam followers 25 are fitted and which pusher mechanism 28 is configured to come into contact with the half-shells 20 to drive the tilting movement of the walls 21.

Thus, the wall 21 is movably coupled to the rear wall 56 of the half-shell 20 by means of a hinge 29 (fig. 4, 5a and 5b), which hinge 29 is configured to allow the wall 21 to rotate about the direction C with respect to the rear wall 56.

Pusher mechanism 28 comprises a pushing pin 30 coupled to cam follower 25, in particular integrally fixed to cam follower 25, so that a transverse movement of cam follower 25 along direction B and towards axis X corresponds to a transverse movement of pushing pin 30 along direction B and towards axis X.

When the trolley 7 is pushed along the operating branch P1 or Q1, the pushing pins 30 are arranged behind the rear wall 56 of the half-shell 20 and the wall 21 with respect to the direction B and are configured to push onto the wall 21 to drive the wall 21 in rotation about its hinge 29, so as to control the wall 21 and therefore the angular movement angle α of the inclination of the respective tube portion 13.

Preferably, the rear wall 56 is provided with a through hole (fig. 5a-5b) through which, in use, the pin 30 is pushed and then reaches the wall 21.

In view of the above, the rotation of the fins 22 and the tilting of the wall 21-and the tilting of the tube portion 13-are driven by the same actuator means, i.e. the cam follower 25 and the cam element 26.

To this end, the trolley 7 comprises a stop member 31, which stop member 31 is configured to stop the movement of the lever mechanism 27 that controls the rotation of the flap 22, while allowing an additional stroke of the pusher mechanism 28 and, therefore, of the pin 30 in the direction B.

In detail, the stop members 31 are configured to abut against the abutment surface of the trolley 7 once the fins 22 reach their final position around the tube portion 13.

Due to this configuration of the actuator means, no dedicated actuator means configured to drive the tilting of the wall 21 is required.

In view of the above, the wall 21 and the tube portion 13 can be moved between:

a first position in which the pin 30 is detached from the wall 21, the wall 21 is parallel to the axis X and to the direction a, and the axis Y of the tube portion 13 remains parallel to the axis X and to the sealing plane S (fig. 5 a); and

a second position in which pin 30 has pushed wall 21 so that wall 21 is inclined by angle α, tube portion 13 is inclined by angle α and top sealing band 3a has been formed in alignment with sealing plane S and axis X (fig. 5 b).

Preferably, in order to ensure that the wall 21 automatically returns from the second position to the first position, resilient means are provided, such as a spring member 32 resiliently coupling the wall 21 to the rear wall 56.

More specifically, the spring member 32 is arranged on the side of the wall 21 with respect to the direction a, which is the opposite side with respect to the side on which the hinge 29 is arranged.

Conveniently, for a given pair of half-shells 20 cooperating with each other to form pack 3, the positions of hinge 29 and spring member 32 are reversed with respect to each other along direction a. In other words, the first half-shell 20 of the pair has a wall 21 hinged to the upper portion (with respect to direction a) of the respective rear wall 56, and the second half-shell 20 of the pair has a wall 21 hinged to the lower portion (with respect to direction a) of the rear wall 56.

In this manner, lateral movement of the cam follower 25 by the shaped cam member 26 tilts the wall 21 by the angle α -i.e., the tube portion 13 by the angle α -so that the top seal belt pattern 3a is offset relative to the axis Y by the distance 55 in the package 50 without compromising the structural integrity of the package 50, as can be seen in fig. 7 a.

Conveniently, each forming unit 18 is movable along the direction a towards a respective sealing unit 19 of each trolley 7 in a known and not described in detail manner. This movement allows the formation of sloping top and

bottom walls

53, 54.

The operation of the packaging assembly 1 is described hereinafter starting from the condition in which a pair of cooperating carts 7 slides along a respective track 6, following a respective path P, Q and approaching a respective operating branch P1, Q1.

In this case, each trolley 7 moves along the respective operating branch P1, Q1 and in direction a, and the half-shells 20 (walls 21 and fins 22), the counter-sealing means 17, the sealing means 23 and the cutting elements are actuated in turn by means of the interaction of the cam followers of the cam assembly 24 with the respective cam elements.

At the same time, tube 2 is filled from above with the pourable product.

After the tabs 22 have completed their rotation and come into contact cooperation with the respective tube portion 13 to be formed, the stop members 31 abut against the respective abutment surfaces and the pins 30 start to move, thanks to the extra travel available.

As soon as the pins 30 contact the respective walls 21, the walls 21 start to rotate about the hinges 29, respectively, so as to tilt the angle α in order to follow the rotation imparted to the tube portion 13 by the sealing operation.

After completion of the formation, sealing and cutting of tube 2, so as to obtain packages 3, half-shells 20, counter-sealing means 17, sealing means 23 and the cutting elements are returned to their idle position. The formed and filled packages 3 are transferred to the exit conveyor 10 and to the above-mentioned folding unit to be folded into finished packages 50.

The carts 7 then slide along the respective return branches P2, Q2 until they again reach the respective operating branches P1, Q1 to form another pack 3.

The entire operating cycle is repeated for each packet 3 to be formed, sealed and cut. The entire operation is also repeated for each pair of trolleys 7 present in the packaging assembly 1.

The reference numeral 7 'in figure 6 generally designates a cart for a packaging assembly 1' according to a second embodiment of the present invention.

The packaging assembly 1 'and the cart 7' are similar to the packaging assembly 1 and the cart 7 according to the first embodiment, the following description is limited to the differences between them, and the same reference numerals are used for the same or corresponding parts where possible.

It is also noted that the features described below for the cart 7' apply to all carts 7' that may be present in the packaging assembly 1 '.

In particular, the packaging assembly 1' differs from the packaging assembly 1 in the type of actuator means used for driving the tilting movement of the tube portion 13.

In detail, the packaging assembly 1' comprises dedicated actuator means specifically configured to drive the tilting movement of the tube portion 13.

In more detail, the actuator means comprise a dedicated cam follower 33, which dedicated cam follower 33 is configured to cooperate in a sliding manner with the cam surface of the dedicated cam element 34 of the cam assembly 24'.

More specifically, the trolley 7 'comprises a forming unit 18' carrying a half-shell 20 'having a main wall 21', the main wall 21 'being coupled to the cam follower 33 by means of a lever mechanism 35, the lever mechanism 35 being configured to convert the transverse movement of the cam follower 33 into an oblique movement of the wall 21' at an angle α.

In detail, according to this preferred embodiment, the whole half-shell 20' can be tilted by the angle α.

In particular, the half-shells 20' can be tilted with respect to the respective movable element 57.

This particular arrangement allows a dedicated control mechanism to tilt the half-shell 20', and therefore also the tube portion 13, and allows to avoid the need for the pusher mechanism 28, the hinge 29 and the spring member 32.

The advantages of the packaging assembly 1, 1' according to the present invention will be clear from the foregoing description.

In particular, thanks to the oblique movement of the walls 21, 21', the forming unit 18, 18' can follow and control the rotation of the tube portion 13 imparted thereto due to the particular configuration of the crease lines in the package 50 with the oblique top wall 53 during the sealing operation, in which case the carts 7, 7' can be moved annularly along the annular track 6 by means of linear motors.

This further allows to obtain a top sealing band 3a of each package 50 (which is offset with respect to the axis Y of such package 50), which provides more space on the sloping top wall 53 to mount the opening devices 54 thereon, without compromising the structural integrity of the package 50.

Moreover, the configuration of the packaging assembly 1' and of the trolley 7' allows to separate the actuation of the rotation of the control flap 22 from the actuation of the inclination of the control wall 21 '; in practice, the fins 22 can be controlled even when the corresponding walls 21 'and half-shells 20' are tilted, collisions between the parts can be avoided and the tilting operation is more precise.

Clearly, changes may be made to the packaging assembly 1, 1' as described herein without, however, departing from the protective scope as defined in the accompanying claims.

Claims

1. A packaging assembly (1; 1') configured to form and seal, starting from a tube (2) of packaging material, a plurality of packages (3) containing pourable products;

the packaging assembly (1; 1') comprises:

-a pair of endless tracks (6) between which the tube (2) is fed along a linear advancement direction (a); and

-a pair of movable members (7; 7'), each of which is movably coupled to a respective track (6) and can move cyclically along said track (6);

each movable member (7; 7') of said pair of movable members (7; 7') movably carries a respective forming member (20; 20'), said forming member (20; 20') being linearly movable towards said tube (2), transversely to said advancing direction (A), to cyclically come into contact with a continuous tube portion (13) so as to form at least a corresponding package portion of a respective package (3);

wherein each forming member (20; 20') comprises a movable portion (21; 21'), said movable portion (21; 21') being tiltable with respect to said advancing direction (A) to sequentially control the tilting of said tube portion (13) with respect to said advancing direction (A).

2. The package assembly according to claim 1, wherein each movable member (7; 7') comprises a movable element (57) which is linearly movable towards the tube (2) and supports the respective movable portion (21); each movable portion (21) is tiltable relative to the corresponding movable element (57).

3. A package assembly according to claim 1 or 2, wherein each movable member (7; 7') movably carries a respective sealing member (17, 23) configured to seal the tube portion (13) transversely;

each forming member (20; 20') is movable along the longitudinal direction (A) with respect to the respective sealing member (17, 23).

4. The package assembly according to any one of the preceding claims, wherein the movable portion (21; 21') is tiltable by a given angle (a) with respect to the advancing direction (A).

5. The package assembly according to any one of the preceding claims, and further comprising actuator means (25, 26; 33, 34) configured to drive the tilting movement of each movable portion (21; 21').

6. A package assembly according to claim 5, wherein, for each track (6), the actuator means comprise at least one cam surface (26; 34) fixed with respect to the track (6), and a cam follower (25; 33), the cam follower (25; 33) being carried by the respective forming member (20; 20') and being configured to cooperate in a sliding manner with the cam surface (26; 34).

7. The packaging assembly (1) according to claim 6, wherein each forming member (20) comprises a forming element (22), said forming element (22) being configured to form a respective portion of the package (3); the cam follower (25) being mechanically connected to the forming element (22); the actuator means (25, 26) are also configured to drive the forming element (22).

8. The packaging assembly (1) according to claim 6 or 7, wherein said cam follower (25) is configured to cooperate with said cam surface (26) to move transversally to said advancing direction (A);

and wherein said movable member (7) comprises a pusher mechanism (28), said cam follower (25) being fitted to said pusher mechanism (28) and said pusher mechanism (28) being configured to cooperate in contact with the respective movable portion (21) to drive said tilting movement of said movable portion (21).

9. The packaging assembly (1) according to claim 8, wherein said movable portion (21) is coupled to said forming member (20) at least by means of a hinge (29);

the pusher mechanism (28) comprises a pushing pin (30), the pushing pin (30) being integrally fixed to the cam follower (25) and configured to push onto the respective movable portion (21) to drive the movable portion (21) in rotation about the hinge (29) to cause the tilting of the movable portion (21).

10. The packaging assembly (1') according to claim 6, wherein said cam follower (33) is configured to cooperate with said cam surface (34) to move transversally to said advancing direction (A);

and wherein the cam followers (33) are coupled to the respective forming members (20') by means of a lever mechanism (35), the lever mechanism (35) being configured to convert a transverse movement of the cam followers (33) into a tilting movement of the movable portion (21') by the given angle (a);

said actuator means (33, 34) being dedicated to driving said tilting of said movable portion (21').

11. The package assembly according to any one of the preceding claims, wherein each movable member (7; 7') and the respective track (6) define a linear motor.

12. The packaging assembly according to any one of the preceding claims, comprising a plurality of pairs of movable members (7; 7') cyclically movable along said track (6), respectively;

wherein the movable members (7; 7') that move, in use, along one track (6) of the pair of tracks (6) are independently movable relative to each other and are configured to cooperate with corresponding movable members (7; 7') that move, in use, along the other track (6) of the pair of tracks (6).

13. The package assembly according to any one of the preceding claims, wherein the movable portion (21; 21') is tiltable so as to allow the formation of a package (50) having a tilted wall (53).

14. A method for forming and sealing a plurality of packages (3) containing pourable products, starting from a tube (2) of packaging material, said method comprising the steps of:

i) -feeding the tube (2) between two endless tracks (6) in a linear advancement direction (a);

ii) cyclically advancing a pair of forming members (20; 20');

iii) bringing the forming member (20; 20') are moved linearly towards said tube (2) to cooperate cyclically in contact with the continuous tube portion (13) to form at least respective package portions of respective packages (3); and

iv) inclining the forming member (20; 20') of the respective movable portion (21; 21') to sequentially control the inclination of said tube portion (13) with respect to said advancing direction (a).

15. The method of claim 14, wherein said step iii) of linearly moving comprises the steps of:

v) linearly moving the movable elements (57) of a pair of movable members (7, 7'), each movable element (57) supporting a respective movable portion (21), each movable member (7; 7') movably coupled to a respective track (6) and cyclically movable along said track (6);

and wherein said step iv) of tilting comprises the steps of:

iv) having each movable portion (21; 21') are inclined with respect to the respective movable element (57).

16. The method of claim 14 or 15, and further comprising the steps of:

vii) transversely sealing the tube portion (13) by means of a pair of sealing members (17, 23), each sealing member (17, 23) being formed by a respective movable member (7; 7'), each movable member (7; 7') movably coupled to a respective track (6) and movable cyclically along said track (6), each movable member (7; 7') movably carrying a respective forming member (20; 20');

viii) moving each forming member (20; 20').