TECHICAL FIELD

The present invention relates to a folding unit and method for forming an empty package.

The present invention provides advantageous application for forming an empty package intended to contain a tube of toothpaste, to which the present invention will make explicit reference without loss of generality.

PRIOR ART

Normally, when packaging the tubes of toothpaste the packages, that had been previously formed and had been subsequently filled with the corresponding tubes of toothpaste, are used.

In most of the packaging machines on the market, the packages are fed already formed and flattened; consequently, in the packaging machine each package already formed is erected (by rotating two opposite side walls 90° with respect to the bottom and top base walls), and then is filled with the corresponding tube of toothpaste that is inserted axially inside the package itself. However, the packaging machines on the market show modest yield (i.e. the number of pieces that can be produced per unit hour) which can be significantly increased only at the expense of the final quality of the package. The patent application DE102008023782A1 describes the formation of a rigid pack of cigarettes with rounded corners on a packing machine that operates continuously. The packing machine comprises:

a store containing a stack of blanks;

a folding wheel which rotates continuously about a first axis of rotation and supports a plurality of folding heads, each of which is provided with a seat for housing a corresponding blank;

a feed wheel which is located between the store and the folding wheel, rotates continuously about a second axis of rotation, and supports a plurality of pickup heads, each of which is designed to retain a corresponding blank allowing to cyclically move the pickup head between a pickup station where the pickup head withdraws a blank from the store and a feed station where the pickup head releases the blank to the seat of a corresponding folding head;

and a weakening station which is provided with a weakening member and is arranged next to the feed wheel.

DESCRIPTION OF THE INVENTION

The object of the present invention is to provide a folding unit and method for forming an empty package, which unit and folding method allow to achieve high productivity and are, at the same time, easy and inexpensive to manufacture. According to the present invention, a folding unit and method for forming an empty package, as claimed in the attached claims are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment, wherein:

- Figure 1 is a plan view of a blank which is used for forming a package designed to contain a tube of toothpaste;

- Figures 2-5 are four perspective views which illustrate corresponding folding steps of the blank of Figure 1 to form a tubular package open at its opposite ends;

- Figure 6 is a schematic front view of a packaging machine which is provided with a folding unit implemented according to the present invention and uses the blanks of the type shown in Figure 1 for the packaging of tubes of toothpastes; - Figure 7 is a schematic side view of the packaging machine of Figure 6;

- Figure 8 is a plan and schematic view of the packaging machine of Figure 6; and

- Figure 9 is a front, schematic and enlarged scale view of a folding unit of the packaging machine of Figure 6 in which tubular packages are made according to the folding steps illustrated in Figures 2-5;

- Figures 10-15 are six perspective views which illustrate corresponding folding steps, according to a different embodiment, of the blank of Figure 1 for forming a tubular package open at its opposite ends;

- Figure 16 is a schematic front view of a different embodiment of the folding unit of Figure 9 in which tubular packages according to the folding steps shown in Figures 10-15 are made;

- Figure 17 is a perspective and schematic view of an alternative of the packaging machine of Figure 6 that uses the folding unit of Figure 16;

- Figure 18 is a schematic front view of the packaging machine of Figure 17;

- Figures 19-21 are three perspective views which illustrate corresponding folding steps of a flattened tubular package;

- Figure 22 is a schematic front view of an alternative configuration of the folding unit of Figure 16 in which tubular packages are made according to the folding steps shown in Figures 19-21 using the flattened tubular packages of the type illustrated in Figure 19;

- Figure 23 is a schematic front view of an alternative of the folding unit of Figure 16 in which the tubular packages are made according to the folding steps shown in Figures 10-15; and

- Figure 24 is an enlarged scale view of a part of Figure 23. PREFERRED EMBODIMENTS OF THE INVENTION

In Figure 1 the number 1 denotes as a whole a blank of cardboard that is used for forming a package 2 (shown in Figure 5) intended to contain a tube of toothpaste 3 (illustrated schematically in Figures 6, 7 and 8) . The blank 1 comprises two pre-weakened transverse fold lines 4 and four pre-weakened longitudinal fold line 5, between the pre-weakened transverse fold lines 4, a connecting tab 6 and four panels 7-10 which constitute four corresponding lateral walls of the package 2. Each panel 7-10 has a pair of corresponding flaps 11, which are arranged on the opposite sides of the panel, 7-10, are separated from the panel 7-10 by the two pre-weakened transverse fold lines 4 and are folded to form two end walls of the package 2. During the forming of the package 2, the connecting tab 6 is gummed (i.e. provided with glue) to stabilize the shape of the package 2 by adhering permanently the connecting tab 6 to an inner surface of the panel 10. During the closing of the open ends of the package 2, the flaps 11 of the panel 7 are gummed (i.e. provided with glue) to stabilize the two end walls by adhering permanently each flap 11 of the panel 7 to the underlying flap 11 of the panel 10.

As illustrated in Figures 2-5, the forming of the package 2 includes folding the panels 7 and 9 90° with respect to panel 8 and about corresponding pre-weakened longitudinal fold lines 5 giving the blank 1 a U-shape (as shown in Figure 3) . Subsequently, the connecting tab 6 is folded 90° with respect to the panel 7 and about a corresponding pre-weakened longitudinal fold line 5 (as shown in Figure 4) . Finally, the panel 10 is folded 90° with respect to panel 9 and about a corresponding pre-weakened longitudinal fold line 5 to be superimposed onto the connecting tab 6 previously folded (as illustrated in Figure 5); as mentioned earlier, the connecting tab 6 is previously gummed (i.e. provided with glue) in order to be permanently glued to an inner surface of the panel 10. In Figures 6, 7 and 8 with the number 12 is shown as a whole a packaging machine for packaging the tubes 3 of toothpaste in the packages 2 obtained by folding the blanks 1 according to the folding sequence shown in Figures 2-5.

As shown in Figure 6, the packaging machine 12 comprises a folding unit 13 in which the blanks 1 are folded to form the open packages 2 and an insertion unit 14 in which the tubes of toothpaste 3 are inserted longitudinally inside of the packages 2 previously obtained.

As shown in Figure 9, the folding unit 13 comprises a folding wheel 15 which is arranged vertically, is rotatably mounted about a horizontal axis of rotation 16 and is designed to turn with continuous motion (i.e. at constant speed) about the axis of rotation 16 itself (counterclockwise as shown in Figure 6) to cyclically run along a circular folding path PI. The folding wheel 15 supports a plurality of folding heads 17, each of which is provided with a U-shaped seat (preferably suctioning) which is adapted to receive and accommodate a corresponding blank 1 for folding the blank 1 itself, and then form (along the folding path PI) a package 2. The folding unit 13 further comprises a store 18 which is horizontally arranged, and houses a stack of blanks 1 and a feed wheel 19 which is arranged between the store 18 and the folding wheel 15 to extract the blanks 1 from an outlet of the store 18 and feed the same blanks 1 one after the other to the seats of the corresponding folding heads 17. The feed wheel 19 is arranged vertically, is rotatably mounted about a horizontal axis of rotation 20 (and parallel to the axis of rotation 16) and is designed to turn with continuous motion (i.e. at constant speed) about the axis of rotation 20 itself to cyclically run along an annular feed path P2. The feed wheel 19 supports an assembly of suction pickup heads 21, each _r

- 6 - of which is designed to retain a corresponding blank 1 during transfer of the blank 1 from the outlet of the store 18 to the seat of a corresponding folding head 17. In particular, the movement of the feed wheel 19 cyclically moves each pickup head 21 between a pickup station SI in which the pickup head 21 withdraws a blank 1 from the outlet of the store 18 and a feed station S2 in which the pickup head 21 inserts the blank 1 folded into a "U" inside the seat of the corresponding folding head 17; in other words, each blank 1 initially flat (as shown in Figure 2) is folded into a "U" (as shown in Figure 3) entering the seat of the corresponding folding head 17. Therefore inside the seat of the corresponding folding head 17, each blank 1 folded into a "U" has its panel 8 arranged contacting a bottom wall of the seat, its panels 7 and 9 arranged in contact with respective side walls of the seat, its connecting tab 6 projecting from a side wall of the seat, and its own panel 10 projecting from the other side wall of the seat. In the preferred embodiment illustrated in the attached figures, each pickup head 21 is rigidly connected to the feed wheel 19 (i.e. is not able to perform any movement with respect to the feed wheel 19) and the feed wheel 19 is rotatably mounted both about the axis of rotation 20 which constitutes the central axis of symmetry of the feed wheel 19, and about a further horizontal axis of rotation 22 which is parallel to and spaced from the axis of rotation 20; in other words, the axis of rotation 20 is perfectly centered with respect to feed wheel 19 while the axis of rotation 21 is eccentric (i.e. off center) with respect to feed wheel 19. Consequently, in use the feed wheel 19 rotates simultaneously both about the axis of rotation 20 which constitutes the central axis of symmetry of the feed wheel 19, and about the axis of rotation 21 which is parallel and spaced with respect to the axis of rotation 20. In particular, a rotating arm 23 is provided, which at a first end is hinged to a frame of the packaging machine 12 and about the axis of rotation 22 to rotate continuously about the axis of rotation 22 itself and at a second end opposite to the first end supports the feed wheel 19 in rotary manner about the axis of rotation 16 for rotating the feed wheel 19 continuously about the axis of rotation 16. In this embodiment, the feed path P2 cyclically followed by each pickup head 21 has a "four point" shape, well illustrated in Figure 9. According to a preferred embodiment, illustrated in Figure 9, each folding head 17 is hinged to the folding wheel 15 to rotate (as a result of a camshaft actuating system) with respect to the folding wheel 15 itself about an axis of rotation 24 which is parallel to and spaced from the axis of rotation 16; the relative movement between each folding head 17 and the folding wheel 15 serves to confer the folding head 17 a particular orientation in the instants in which the folding head 17 receives or transfers the corresponding blank 1. In the feed station S2 in which each blank 1 enters in the seat of the corresponding folding head 17, the folding head 17 itself is rotated about the axis of rotation 24 at first faster and then slower than the folding wheel 15 for coupling the folding head 17 with the corresponding pickup head 21 holding one blank 1.

According to a preferred embodiment, in the feed station S2 each pickup head 21 is inserted inside the seat of the corresponding folding head 17 for folding into a "U" the blank 1 inside the seat; in this way, each pickup head 21 and the seat of the corresponding folding head 17 cooperate together as a mold-counter-mold for folding into a "U" the blank 1 inside the seat. According to a possible embodiment, each pickup head 21 is entirely rigid; however, this solution does not allow a buffered contact, with the interposition of a blank 1, between each pickup head 21 and the seat of the corresponding folding head 17 during a feeding step of the blank 1 to the folding wheel 15. To remedy this situation, a portion of each pickup head 21 can be obtained with an elastically deformable material to impart the pickup head 21 a (small) axial elastic deformability . Thanks to the fact that each pickup head 21 and the seat of the corresponding folding head 17 cooperate together as a mold-counter-mold for folding into a "U" the blank 1 inside the seat, the "U" folding of the blank 1 is executed with excellent quality (i.e. showing longitudinal edges perfectly shaped) .

The folding unit 13 comprising a gumming device 25, which is arranged near the feed wheel 19 to apply the glue (preferably hot, i.e. preferably fast setting) to the outer surface of the connecting tab of each blank 1 (during the subsequent folding of the blank 1, the outer surface of the connecting tab will be superimposed on the inner surface of the panel 10 so as to determine a permanent gluing between the connecting tab 6 and the panel 10) . In the embodiment schematically illustrated in Figure 9, the gumming device 25 is of the roller type, i.e. comprises a rotating gumming roller, in which its lateral surface is cyclically immersed in a glue bath, and then brought into contact with the connecting tab of a blank 1. According to an alternative and perfectly equivalent embodiment not illustrated, the gumming device 25 is of the spray type, i.e. comprises one or more gumming guns that are activated to spray glue under pressure towards the connecting tab of a blank 1.

The folding unit 13 comprises a folding device 26, which is arranged near the folding wheel 15 downstream of the feed station S2 for folding the connecting tab 6 of each blank 1 projecting from the seat of the corresponding head 17 90° (i.e. the connecting tab constitutes one end of the blank 1 which projects from the seat of the corresponding folding head 17) . In other words, downstream of the folding device 26 each blank 1 has the conformation illustrated in Figure 4. In addition, the folding unit 13 comprises a folding device 27, which is arranged near the folding wheel 15 immediately downstream of the folding device 26 for folding the panel 10 of each blank 1 projecting from the seat of the corresponding folding head 17 90° (i.e. the panel 10 constitutes one end of the blank 1 which projects from the seat of the corresponding folding head 17), and then completing the formation of the package 2. In other words, downstream of the folding device 26 each blank 1 has the conformation illustrated in Figure 5 and forms a corresponding package 2.

According to a preferred, but non limiting embodiment illustrated in Figure 9, the folding device 26 comprises a folding member 28 which acts on the connecting tab 6 of the blank 1 projecting from the seat of the folding head 17 and a rotating arm 29, which is hinged to a frame of the packaging machine 12 at a first end to rotate with alternating directions about an axis of rotation 30 parallel to the axis of rotation 16 and at a second end opposite to the first end supports the folding element 28. In use, the rotating arm 29 of the folding device 26 starting from an initial position (in which the folding member 28 does not interfere with the passage of a corresponding folding head 17 holding a blank 1) rotates at a higher speed and following the same advancement direction of the folding head 17 to bring the folding element 28 in contact with the connecting tab of the blank 1 so as to fold the connecting tab 6 90°; at the end of folding the connecting tab 6, the rotating arm 29 of the folding device 26 reverses its rotation direction to return to the initial position before the passage of the next folding head 17. In other words, the rotating arm 29 of the folding device 26 cyclically rotates back and forth to fold, at each step, the connecting tab 6 of a corresponding blank 1 held by the seat of a folding head 17.

According to a preferred, but non limiting embodiment _Λ

- 10 - illustrated in Figure 9, the folding device 27 comprises a folding member 31 acting on the panel 10 of the blank 1 which projects from the seat of the corresponding folding head 17 and an articulated parallelogram 32 supporting the folding element 31. The articulated parallelogram 32 comprises a rod 33 which is hinged at one end to a frame of the packaging machine 12, a rod 34 which is parallel and opposite to the rod 33 and supports the folding member 31, a rod 35 connecting the rod 33 to the rod 34 at the ends of the rod 33 hinged to the frame, and a rod 36 which is parallel and opposite to the rod 35. According to a preferred embodiment the folding member 31 comprises an ironing surface 37 that has a size greater than the size of the panel 10 of each blank 1 and rests on the panel 10 to drag along the panel 10 itself during the rotation of the folding wheel 15. In other words, once the panel 10 of a blank 1 is folded 90°, the ironing surface 37 is constantly oriented to remain parallel to and rests onto the panel 10 to drag along the panel 10 itself during the rotation of the folding wheel 15.

According to a preferred, but non limiting, embodiment illustrated in Figure 9, the folding unit 13 comprises a contrast element 38 U-shaped and an actuator device 39 (shown schematically in Figure 7) that inserts the contrast element 38 inside the seat of each folding head 17 upstream of the folding devices 26 and 27 (i.e. upstream of the folding device 26) and extracts the contrast element 38 from the seat of the folding head 17 downstream of the folding devices 26 and 27 (i.e. downstream of the folding device 27) by making the contrast element 38 itself and for a certain distance perform a synchronous movement with the movement of the folding head 17. In this way, the folding devices 26 and 27 fold the tab 6 and the connecting panel 10 of each blank 1 (i.e. the two ends of the blank 1 projecting from the seat of the corresponding folding head 17) onto the contrast element 38. In particular, the action of the contrast element 38 allows to press with a high pressure the panel 10 and the connecting tab of each blank 1 between the ironing surface 37 of the folding element 31 (external to the package 2) and the contrast element 38 (internal to the package 2) allowing to obtain an optimum and very strong bonding between the panel 10 and the connecting tab .

In other words, immediately upstream of the folding device 26 the actuating device 39 inserts with an axial movement (i.e. parallel to the axis of rotation 16) the contrast element 38 inside the seat of each folding head 17, between the folding device 26 and the folding device 27, the actuating device 39 moves the contrast element 38 along the packing path PI and in synchronism with the folding head 17, and finally downstream of the folding device 27 the actuating device 39 extracts with an axial movement (i.e. parallel to the axis of rotation 16) the contrast element 38 from the seat of the folding head 17. Then, the actuator device 39 is able to move the contrast element 38 both axially, i.e. perpendicularly to the folding path PI, to insert /remove the contrast element 38 in/from each folding head 17, and parallel to the folding path PI (i.e. approximately along an arc of circumference) to follow each folding head 17 during part of its advancement along the folding path PI. In use, the contrast element 38 cyclically performs an annular path having an operating step in which the contrast element 38 moves together with each folding head 17 from an initial position arranged upstream of the folding device 26 up to a final position arranged downstream of the folding device 27, and a return step in which the contrast element 38 is away from the folding heads 17 and returns from the final position to the initial position to be ready to start a new operating step.

Thanks to the combined action of the folding element 31 and of the contrast element 38, it is possible to press together the panel 10 and the connecting tab of each blank 1 with a high „

- 12 - pressure allowing to obtain an optimal and very strong gluing between the panel 10 and the connecting tab (thus a gluing which is able to endure without problems even when the operating speed of the packaging machine 12 is high) . Moreover, thanks to the combined action of the folding elements 28 and 31 and of the contrast member 38, the folding of the connecting tab 6 and of the panel 10 of each blank 1 takes place in a qualitatively excellent way (i.e. having longitudinal edges perfectly conformed) .

In a transfer station S3 arranged downstream of the folding devices 26 and 27, each package 2 is transferred from the seat of a corresponding folding head 17 to the insertion unit 14. Even in the transfer station S3 where each package 2 leaves the seat of the corresponding folding head 17, the folding head 17 itself is rotated about the axis of rotation 24 first faster and then slower than the rotation of the folding wheel 15 for coupling the folding head 17 with the insertion unit 14.

As illustrated in Figures 6, 7 and 8, the insertion unit 14, wherein each tube of toothpaste 3 longitudinally inside a corresponding package 2 is inserted, comprises a release conveyor 40 (schematically shown in Figures 7 and 8) that advances with continuous motion and is provided with pockets 41 designed to house the tubes 3 of toothpaste and a receiving conveyor 42 which advances with continuous motion in synchronism with the release conveyor 40, is provided with pockets 43 for housing the packages 2, receive the package 2 from the folding wheel 15 in the release station S3, and has an insertion portion P3 which extends parallel and next to the release conveyor 40. Also, the insertion unit 14 comprises a plurality of pushers 44 (schematically shown in Figures 7 and 8), each of which, along the insertion portion P3, advances with continuous motion in synchronism with the two conveyors 40 and 42 and moves perpendicular to the insertion portion P3 „

- 13 - to axially transfer each tube 3 of toothpaste from a pocket 41 of the release conveyor 40 to a pocket 43 of the receiving conveyor 42. According to a preferred embodiment, the release conveyor 40 is a belt conveyor provided with a belt, which is wound in a loop about two end pulleys (one of which is motorized) and has possible transverse ribs which laterally delimit the pockets 41. Similarly and according to a preferred embodiment illustrated in Figure 6, the receiving conveyor 42 is a belt conveyor 45 provided with a belt, which is wound in a loop about two end pulleys 46 and 47 (one of which is motorized) and has possible transverse ribs which laterally delimit the pockets 43. The pulley 47 of the receiver conveyor 42 has a dimension greater than the pulley 46, is vertically arranged, is rotatably mounted about a horizontal axis of rotation 48 (parallel to the axis of rotation 16) and is designed to turn with continuous motion (i.e. at constant speed) about the axis of rotation 48 itself (clockwise as illustrated in Figure 6) . The pulley 46 is provided with a plurality of axially oriented ribs 49, which are arranged on opposite sides of the belt 45 of the receiver conveyor 42 and constitute extensions of the pockets 43 of the receiver conveyor 42. As illustrated in Figures 7 and 8, an actuator device 50 is provided which moves the pusher 44 by conferring to the pushers 44 themselves both an advancement motion parallel to the insertion portion P3, synchronized with the two conveyors 40 and 42, and an insertion movement perpendicular to the insertion portion P3.

As shown in Figure 8, the insertion unit 14 comprises a folding device 51 which is arranged along the receiving conveyor 42 and upstream of the insertion portion P3 and folds in a known way the flaps 11 of a front end wall of each package 2 conveyed by the receiving conveyor 42 itself; furthermore, the insertion unit 14 comprises a folding device 52 which is arranged along the receiving conveyor 42 and downstream of the insertion portion P3 and folds in a known way the flaps 11 of a rear end wall of each package 2 conveyed by the receiving conveyor 42 itself.

According to a preferred embodiment illustrated in Figure 8, the insertion unit 14 comprises a printing device 53 (for example, inkjet) , which is arranged along the receiving conveyor 42 and downstream of the folding device 51 to print at least one identification code (for example containing date and place of packaging) on the front end wall of each package 2 conveyed by the receiving conveyor 42 itself. According to a preferred embodiment illustrated in Figure 6, the store 18 of the blanks 5 is horizontally oriented and is arranged above the two conveyors 40 and 42; said arrangements allows to optimize the use of space without compromising in any way the full access to all components of the packaging machine 12. In this way, the packaging machine 12 is particularly compact while showing an optimal accessibility to all its components.

In the embodiment illustrated in the attached figures, the folding unit 13 is part of the packaging machine 12, and therefore is directly coupled to the insertion unit 14. According to a different embodiment not illustrated, the folding unit 13 could be followed by a flattening unit, which flattens each package 2 (i.e. makes each package 2 assume a flat shape) for forming a stack of flattened packages 2 which is fed at a later time to a packaging machine utilizing standard flattened packages 2. Consequently, the folding unit 13 described above can also be completely autonomous and independent from the packaging machine 12.

In Figures 10-15, a different sequence of folding the blank 1 illustrated in Figure 1 for forming the package 2 is illustrated. Starting from the flat blank 1 illustrated in Figure 10, forming the package 2 initially provides the folding of the panels 8 and 10 with respect to the panel 9 and about corresponding longitudinal pre-weakened fold lines 5 giving the blank 1 a U-shape (as shown in Figure 11) ; at this step, the panels 8 and 10 are folded with respect to the panel 9 and about corresponding longitudinal pre-weakened fold lines 5 by an angle less than 90° (i.e. the panels 8 and 10 form with the panel 9 respective obtuse angles) . Subsequently, the panel 8 is further folded with respect to the panel 9 and about a corresponding longitudinal pre-weakened fold line 5 to place the panel 8 at 90° with respect to the panel 9 (as illustrated in Figure 12) . At this point, the panel 7 is folded 90° with respect to panel 8 and about a corresponding longitudinal pre-weakened fold line 5 (as illustrated in Figure 13) . Subsequently, the connecting tab 6 is folded 90° with respect to the panel 7 and about a corresponding longitudinal pre-weakened fold line 5 (as illustrated in Figure 14) . Finally, the panel 10 is further folded with respect to panel 9 and about a corresponding longitudinal pre- weakened fold line 5 to place the panel 10 at 90° with respect to the panel 9 and onto the connecting tab, i.e. to be superimposed onto the connecting tab 6 previously folded (as illustrated in Figure 15) ; as mentioned earlier, the connecting tab is previously gummed (i.e. provided with glue) in order to be permanently glued to an inner surface of the panel 10. Figure 16 illustrates a folding unit 13 which represents an alternative of the folding unit 13 illustrated in Figure 9 and folds the blanks 1 according to the folding sequence illustrated in Figures 10-15; in other words, the folding unit 13 illustrated in Figure 9 folds the blanks 1 according to the folding sequence illustrated in Figures 2-5, while the folding unit 13 illustrated in Figure 16 folds the blanks 1 according ^ _r

- 16 - to the folding sequence illustrated in Figures 10-15.

In the folding unit 13 illustrated in Figure 9, the seat of each folding head 17 is devoid of moving parts, i.e. is constituted solely by elements rigidly connected to the folding head 17 itself (i.e. the seat of each folding head 17 comprises two lateral walls which are arranged radially with respect to the folding wheel 15 and are rigidly connected to the folding head 17) ; accordingly, the seat of each folding head 17 never modifies its shape during the advancement along the folding path PI. Whereas, in the folding unit 13 illustrated in Figure 16, the seat of each folding head 17 comprises a suctioning base wall 54 (i.e. designed to retain the blank 1 by suction) rigidly connected to the folding head 17 and two lateral walls 55 and 56 that are hinged to the folding head 17 to rotate (as a result of a camshaft actuating system) with respect to the folding head 17 about respective horizontal axes of rotation 57 parallel and spaced from the axis of rotation 24; accordingly, the seat of each folding head 17 changes its shape during the advancement thereof along the folding path PI by the effect of an opening (i.e. separate from each other) and closing (i.e. towards each other) of the lateral walls 55 and 56. In particular, in the feed station S2 and in the release station S3, the lateral walls 55 and 56 of the seat of each folding head 17 are arranged so as to form between each other and with the base wall 54 an obtuse angle, while between the feed station S2 and the release station S3, the lateral walls 55 and 56 of the seat of each folding head 17 are rotated (in subsequent moments, i.e. not simultaneously) to be arranged parallel to each other and perpendicular to the base wall 54.

The lateral wall 55 of the seat of each folding head 17 ends with a folding appendage 58 which is arranged perpendicular to the lateral wall 55 and, as better described hereinafter, is adapted to fold the panel 7 of the blank 1 90° with respect to the panel 8 of the blank 1 when the lateral wall 55 is rotated to fold the panel 8 itself.

The folding unit 13 comprises a folding device 59 that, as better described hereinafter, folds the connecting tab 6 of the blank 1 90° with respect to the panel 7 of the blank 1. The folding device 59 is arranged outside the folding wheel 15, close to the folding wheel 15 itself, and downstream of the feed station S2; furthermore, the folding device 59 comprises a drum 60 mounted to rotate about a horizontal axis of rotation 61 parallel to the axis of rotation 16, and a pair of folding members 62 which project radially from the drum 60.

In the folding unit 13 illustrated in Figure 9, each pickup head 21 is rigidly connected to the feed wheel 19 (i.e. is not able to perform any movement with respect to the feed wheel 19) and the feed wheel 19 is rotatably mounted both about the axis of rotation 20, which constitutes the central axis of symmetry of the feed wheel 19, and about the further axis of rotation 22. In the folding unit 13 illustrated in Figure 16, each pickup head 21 is movably mounted on the feed wheel 19 to move with respect to the feed wheel 19 itself. In this embodiment, the feed wheel 19 is rotatably mounted only about the axis of rotation 20. Moreover, in this embodiment, the supply path P2 cyclically followed by each pickup head 21 has a circular shape well illustrated in Figure 16. Preferably, each pickup head 21 is hinged to the feed wheel 19 to rotate (by effect of a camshaft actuating system) with respect to the feed wheel 19 itself about an axis of rotation 63 which is parallel to and spaced from the axis of rotation 20; the relative movement between each pickup head 21 and the feed wheel 19 serves to confer the pickup head 21 a particular orientation in the instants in which the pickup head 21 receives or transfers the corresponding blank 1.

In the pickup station SI, each pickup head 21 is rotated about „

- 18 - the axis of rotation 63 first faster and then slower than the rotation of the feed wheel 19 for coupling the pickup head 21 with the outlet of the store 18; in the feed station S2 in which each blank 1 enters the seat of the corresponding folding head 17, each pickup head 21 is rotated about the axis of rotation 63 first faster and then slower than the rotation of the feed wheel 19 for coupling the pickup head 21 with the corresponding folding head 17. According to a preferred embodiment, the feed wheel 19 comprises a plurality of support elements 64, each of which is arranged next to a corresponding pickup head 21, is independent and separated from the pickup head 21 itself, and provides a support for the blank 1 between the pickup station SI and the feed station S2. According to a preferred embodiment, each support element 64 is arranged downstream of the pickup head 21 with respect to the rotation direction of the feed wheel 19 and is L-shaped, i.e. has an operational part arranged circumferentially and a connecting portion arranged radially. Furthermore, according to a preferred embodiment, each support element 64 is hinged to the feed wheel 19 to rotate with respect to the feed wheel 19 itself about an axis of rotation 65 which is parallel to and horizontally spaced with respect to the second axis of rotation 20. The function of each support element 64 is to offer a support to the blank 1 particularly at the gumming device 25 which is arranged between the pickup station SI and the feed station S2; in particular, each support element 64 provides a contrast to a corresponding blank 1 when the blank 1 is in contact with the gumming roller of the gumming device 25 so that the blank 1 rests on the gumming roller of the gumming device 25 with a certain force and therefore ensures optimal gumming of the blank 1 itself. The following describes the operation of the folding unit 13 illustrated in Figure 16. Initially, a pickup head 21 of the feed wheel 19 withdraws a flat blank 1 (i.e. arranged as illustrated in Figure 10) from the mouth of the store 18 at the pickup station SI and then transfers the flat blank 1 from the pickup station SI to the feed station S2 along a feed path P2. Along the feed path P2, the connecting tab of the blank 21 is gummed by a gumming device 25 which is arranged between the pickup station SI and the feed station S2.

Subsequently, in the feed station S2 the pickup head 21 inserts the blank 1 folded into a "U" inside the seat of the folding head 17 so that the panel 9 of the blank adheres to a base wall 54 of the seat of the folding head 17 (the base wall 54 holds the panel 9 by suction) and only one end of the blank 1 projects from the seat of the folding head 17. In this situation, the blank 1 is arranged as shown in Figure 11: the panel 10 rests onto the lateral wall 56 of the seat of the folding head 17 and forms an obtuse angle with the panel 9, the panel 9 rests onto the base wall 54 of the seat of the folding head 17, the panel 8 rests onto the lateral wall 55 of the seat of the folding head 17 and forms an obtuse angle with the panel 9, and the panel 7 together with the connecting tab 6 projects from the seat of the folding head 17 (i.e. constitute the single end of the blank 1 which projects from the seat of the folding head 17) .

Downstream of the feed station S2 the lateral wall 55 of the seat of the folding head 17 is rotated to be arranged perpendicular to the base wall 54 of the seat of the folding head 17; this movement causes both the further folding of the panel 8 with respect to the panel 9 to place the panel 8 perpendicular to the panel 9 (as illustrated in Figure 12), and the folding of the panel 7 90° with respect to the panel 8 (as illustrated in Figure 13) due to the action of the folding appendage 58 of the lateral wall 55 of the seat of the folding head 17. In other words, in the feed station S2 the lateral walls 55 and 56 of the seat of the folding head 17 are arranged so as to form one with the other and with the base wall 54 an obtuse angle and downstream of the feed station S2 the lateral wall 55 of the seat of the folding head 17 is rotated to fold the panel 8 of the blank 1, arranged contacting the lateral wall 55 with respect to the panel 9 of the blank 1 that adheres to the base wall 54 of the seat of the folding head 17 so as to have the panel 8 perpendicular to the panel 9. Moreover, the folding appendage 58 of the lateral wall 55 of the seat of the folding head 17 fold of the panel 7 of the blank 1 90° with respect to the panel 8 of the blank 1 when the lateral wall 55 of the seat of the folding head 17 is rotated to fold the panel 8 of the blank 1.

Subsequently, a folding member 62 of the folding device 59 folds the connecting tab 6 of the blank 1 90° with respect to the panel 7 of the blank 1 (as illustrated in Figure 14) by placing the connecting tab 6 facing the panel 10 of the blank 1 arranged contacting the lateral wall 56 of the seat of the folding head 17.

Finally, downstream of the folding device 59, the lateral wall 56 of the seat of the folding head 17 is rotated to fold the panel 10 of the blank 1, arranged contacting the lateral wall 56 with respect to the panel 9 of the blank 1 that adheres to the base wall 54 of the seat of the folding head 17, and onto the connecting tab (previously gummed) , and so as to have the panel 8 perpendicular to the panel 9.

In Figures 16 and 17 two different views of a packaging machine 12 that is similar to the packaging machine 12 illustrated in Figures 6, 7 and 8 and is provided with a folding unit 13 of the type of that illustrated in Figure 16 (i.e. that executes the folding sequence illustrated in Figures 10-15) are illustrated. In the insertion unit 14 of the packaging machine 12 illustrated in Figures 6, 7 and 8, the release conveyor 40 is arranged behind the receiving conveyor 42 with respect to the frame of the packaging machine 12 (i.e. the release conveyor 40 is arranged between the frame of the packaging machine 12 and the receiving conveyor 42) . Instead, in the insertion unit 14 of the packaging machine 12 illustrated in Figures 16 and 17, the release conveyor 40 is arranged in front of the receiving conveyor 42 with respect to the frame of the packaging machine 12 (i.e. the receiving conveyor 42 is arranged between the frame of the packaging machine 12 and the release conveyor 40); accordingly, the structure of the actuator device 50 that moves the pushers 44 by impressing the pushers 44 themselves both in an advancement motion parallel to the insertion portion P3, synchronized with the two conveyors 40 and 42, and an insertion movement perpendicular to the insertion portion P3, has been modified. Compared to the folding unit 13 illustrated in Figure 9, the folding unit 13 illustrated in Figure 16 has certain advantages. In particular, with respect to the folding unit 13 illustrated in Figure 9, the folding unit 13 illustrated in Figure 16 has a more effective withdrawal of the blanks 1 from the outlet of the store 18 (in particular, the risk of extracting together two blanks 1 instead of only one blank 1 is reduced) , has a better gumming of the blanks 1, has fewer risks of glue splashes that by detaching from the blanks 1 can involve the folding unit 13 (this result is achieved thanks to a feed path P2 devoid of abrupt direction changes and thanks to the support elements 64 that reduce uncontrolled vibration of the portions of the blank 1 not bound to the pickup head 21), has a better insertion of the blanks 1 in the seats of the folding head 17 (in particular the insertion happens more simply thanks to the greater opening of the lateral walls 55 and 56 of the seats and more slowly allowing to obtain more accurate and precise folds), and has a better gluing of the connecting tabs 6 in that for a certain period of time each connecting tab 6 is pressed firmly onto the corresponding panel 10 from the lateral wall 56 of the seat of the respective folding head 17.

In Figures 19-21, a folding sequence of a blank 1 which has previously been folded to assume a tubular shape (as illustrated in Figure 21), and then was subsequently flattened starting from the tubular conformation to assume a flat form (as shown in Figure 19) is illustrated. Starting from the flattened blank 1 illustrated in Figure 19, the formation of the package 2 provides for simply folding the panels 8 and 10 90° with respect to the panels 7 and 9 and about corresponding pre-weakened fold lines 5 (in Figure 20 an intermediate step of this folding process is illustrated) .

The folding unit 13 illustrated in Figure 16 can be simply changed, also for handling flattened tubular packages 2 in place of the flat blanks 1; in other words, in this embodiment, the flat blanks 1 are previously folded to assume a tubular shape (as shown in Figure 21) and then are subsequently flattened starting from the tubular conformation to assume a flat shape (as shown in Figure 19) . As shown in Figure 22, to handle flattened tubular packages 2, or to handle blanks 1 previously folded and flattened, it is sufficient to slightly modify the folding heads 17 of the folding wheel 15, while the feed wheel 19 remains practically the same (of course the gumming device 25 is disabled or disassembled as the application of glue is no longer required) . In particular, each folding head 17 of the seat is modified by eliminating the lateral wall 56 and by using only the lateral wall 55 to "open" the corresponding flattened tubular package 2; in other words, in each folding head 17 the lateral wall 55 of the seat acts as a folding member for pushing on the panel 8 or 10 of the blank 1 adjacent to the panel 9 of the blank 1 that adheres to the base wall 54 for restoring the blank 1 itself from the flat form to the tubular shape thus completing the formation of the package 2. In use, in the pickup station SI the feed wheel 19 withdraws each blank 1 from the mouth of the store 18 and then, in the feed station S2, the feed wheel 19 feeds the blank 1 to the seat of a corresponding folding head 17; in the seat of each folding head 17 the panel 9 of the blank 1 rests onto the base wall 54 holding the panel 9 itself by suction. Downstream of the feed station S2, the lateral wall 55 of each folding head 17 pushes on the panel 8 or 10 of the blank 1 (which is adjacent to the panel 9 of the blank 1 that adheres to the base wall 54) to rotate the panels 8 and 10 90° with respect to the panels 7 and 9 thus completing the formation of the package 2; consequently, the lateral wall 55 of each folding head 17 acts as a folding element that is hinged to the folding head 17 to rotate, with respect to the folding head 17 itself about the corresponding axis of rotation 57. In Figures 23 and 24 an alternative of the folding unit 13 illustrated in Figure 16 is shown. The folding unit 13 illustrated in Figure 23 differs from the folding unit 13 illustrated in Figure 16 for the positioning of the store 18 of the blanks, for the conformation of the feed wheel 19, (that is structurally different but functionally identical to the feed wheel 19 illustrated in Figure 16), for the positioning and the conformation of the receiving conveyor 42, for positioning and conformation of the gumming device 25, and for the feeding mode of the packages 2 to the receiving conveyor 42.

In the folding unit 13 illustrated in Figures 23 and 24, the gumming device 25 is no longer coupled to the feed wheel 19, but is coupled to the folding wheel 15. In particular, the gumming device 25 is arranged in the vicinity of the folding wheel 15 (i.e. along the folding path PI) and (immediately) „

- 24 - upstream of the folding device 59 to apply glue to the connecting tab of each blank 1 before folding the connecting tab 6 itself by means of the folding device 59. The gumming device 25 comprises a rotating gumming element 66 which rotates about an axis of rotation 67 parallel to and spaced from the axis of rotation 16 of the folding wheel 15 and has one end that cyclically applies the glue to the connecting tab of each blank 1. Furthermore, the gumming device 25 comprises a rotating gumming roller 68, which is partially immersed in a glue bath and is arranged next to the gumming element 66 so that cyclically the ends of the gumming element 66 touches a lateral surface of the gumming roller 68 to receive the glue that subsequently the gumming element 66 will apply to the connecting tab 6 of a blank 1.

In the folding unit 13 illustrated in Figures 23 and 24, between the folding wheel 15 and the receiving conveyor 42 a further transfer conveyor 69 is interposed, which receives the package 2 from the folding wheel 15 of the release station S3 and feeds the packages 2 to the pockets 43 of the receiving conveyor 42.

The packaging machine 12 described above (in its many alternatives) has numerous advantages.

In the first place, the packaging machine 12 described above allows to achieve high productivity per hour (i.e. a number of pieces produced in the time unit) while ensuring a high quality standard of the packages 2. This result is obtained also thanks to the fact of allowing the entire packaging machine 12 to operate (and in particular the folding unit 13) in a continuous manner, i.e. always moving at a constant speed, instead of using the intermittent mode which provides a cyclic succession of rest and movement steps; in fact, by operating in continuous mode the packaging machine 12 (and in particular the folding unit 13) can reach high hourly _^

- 25 - production without subjecting the products, at the same time, to intense mechanical stress (i.e. accelerations/decelerations) . Furthermore, the packaging machine 12 described above allows to obtain the packages 2 directly from flat blanks 1 (i.e. without using tubular flattened blanks) having a modest encumbrance and a minimum production cost (with respect to the tubular flattened blanks) .

As mentioned previously, the packaging machine 12 described above is particularly compact, in particular thanks to the fact that the store 18 of the blanks 1 is horizontal and arranged above the conveyors 40 and 42.

The position of the gumming device 25 of the folding unit 13 allows the gumming device 25 to adapt to the various formats of the blanks 1 with extreme simplicity; in other words, in a very simple way the gumming device 25 can be configured to gum blanks 1 of a different shape and/or size.

The packaging machine 12 is easily adaptable to produce special format packages 2 (for example packages 2 having a fin-shaped fold) .

The packaging machine 12 described above is also easy and inexpensive to manufacture, as it is composed of structurally simple and lesser moving elements of easy implementation. Finally, the packaging machine 12 described above provides adequate maneuvering space around each component, and therefore are simplified both in the initial assembly of the components and the subsequent maintenance (from simple cleaning to replacements) of the components themselves.