TECHNICAL FIELD

The present invention refers to the sector of the packagings, and in particular to a pre-assembly station for a plant that produces packagings of variable sizes, such as for example the secondary packagings made according to the logic called BOD (Box On Demand).

BACKGROUND

In the field of goods distribution, providing primary and secondary packagings is widely known.

Each item is usually sold on the market enclosed within its own packaging, called primary, made directly by the manufacturer. The primary packagings are usually studied and manufactured by the manufacturers with the aim of presenting their products in the most appropriate way. In fact, the manufacturer often uses the primary packaging as a communication tool to transmit, through the choice of materials, finishes and graphics, the qualities that he wishes to associate with his product contained in its inside.

Conversely, the secondary packaging is usually provided by a subject other than the manufacturer, such as a distributor, a retailer or a shipper. The secondary packaging contains in its inside one or more products, often unrelated to each other, each complete with its own primary packaging. The secondary packaging is therefore intended to accompany the products only in the steps of handling and shipping the goods and therefore has a purely practical function. The secondary packaging must protect the products in its inside (including the primary packagings thereof) and must be suitable for showing the indications useful for handling and/ or shipping. For this reason the secondary packaging is usually made of simple corrugated cardboard. Once the products are delivered, the secondary packaging ends its function and is disposed of.

With the recent growth of the electronic market, where the products are ordered by the consumers on specific on-line platforms and are thus grouped, repackaged and shipped by the seller, the secondary packagings have become increasingly important.

In the sector of the secondary packagings, different approaches are possible on the part of the seller who ships the products, usually collected into groups according to the customer's orders. For example, a single order may contain a mobile phone with some accessories, such as a power reserve, headphones or a case, but it may also contain completely different objects such as a book, a household item or the like. A first approach is to provide for the seller to use predefined boxes based on a finite number of measurements and proportions. This type of approach therefore envisages arranging each group of products in the box which, among those capable of containing the entire group, has the lowest volume. The general rule is in fact that the cost for shipping a package depends on its weight and on its volume. Once the order defines the products, the total weight of the package is defined, too, net of the weight of the secondary packaging. However, since the differences in weight between the different boxes available are considered as negligible, in order to minimize the shipping costs it is preferable to minimize the volume of the package.

This method of providing the secondary packaging through predefined boxes can be carried out manually or automatically. As the skilled person can well understand, when the method is applied manually, the result of the execution depends to a large extent on the experience and care of the operator. In general, the manual method allows to safely handle all types of products, including the fragile, perishable or potentially dangerous ones. On the other hand, it requires relatively long processing times and implies a rather high probability of error in the optimization of the volume of the box. In fact, the operator, especially in the face of a large workload, can be led to choosing a slightly larger box than strictly necessary if this allows to speed up the operation. Conversely, the automatic execution of this operation, while improving the optimization step, does not allow the management of fragile, perishable or potentially dangerous items. To assess the impact of this limitation on the automatic application of the method, consider for example that all the batteries commonly used in the portable electronic devices are considered potentially dangerous because they are flammable, and therefore cannot be managed automatically.

This type of approach that envisages using a finite number of types of boxes implies in any case, be it manual or automatic, the use of a sub-optimal solution, because rarely a predefined box will be able to be completely filled by the group of products that constitute the order. It is much more likely that an empty portion of volume remains inside each box which portion must be filled with some filling material. This represents a significant disadvantage for several reasons. Firstly, due to the shipping cost which, being linked to the volume of the box, is greater than strictly necessary. In addition, the systematic shipping of enlarged boxes with respect to the actual needs implies a greater number of journeys of the freight carrier, be it an airplane, a ship or a van. Finally, there is a problem of consumer satisfaction. Upon receiving a partially empty box filled with filling material, the consumer perceives the shipment as inefficient and with an environmental impact greater than necessary. A different approach, which tries to solve the drawbacks described above, is that of the so-called BOD (from Box On Demand) which provides for the manufacture of a specific box for each group of objects, or order, being shipped by the seller. In other words, once the group of products to be shipped is defined for a single order, the relative box is built on the spot with ad hoc measurements, thus managing to optimize the volume of the box much more efficiently than the method described above. The BOD approach is much more sophisticated and requires today the use of very complex and expensive plants that create and provide the packaging in a fully automatic way. The plant arranges the products of the order, detects their measurements, cuts the box out of a sheet of cardboard and builds the box around the products. The manufacture of the packaging usually takes place in a discontinuous way, imposing an intermittent operation on the entire plant. This solution guarantees a relatively high speed of execution but, in addition to the high initial cost, like all the fully automatic processes, does not allow to manage fragile, perishable or potentially dangerous items.

Moreover, the constructively very complex solutions introduce other problems such as those of reliability, cost and complexity of integration with the existing lines. There is also a specific problem related to the lack of availability of optimization techniques, both 2D and 3D.

In general, therefore, in the plants of known type, whether they are intended for the production of primary or secondary packagings, of boxes with sizes that are predefined or sized on the spot (BOD), the problem of managing packagings of variable sizes arises each time.

In addition, the very complex solutions introduce other problems such as those of reliability, cost and complexity of integrating this machinery into existing plants or new plant designs, a problem of poor 2D and 3D optimization.

OBJECTS AND SUMMARY OF THE INVENTION

Aim of the present invention is therefore that of at least partially overcoming the drawbacks highlighted above in relation to the prior art.

In particular, a task of the present invention is to make available a pre-assembly station intended for packagings of variable sizes, which can be integrated into a semiautomatic plant, suitable for handling all types of items, including the fragile, perishable or potentially dangerous ones.

Furthermore, a task of the present invention is to make available a pre-assembly station intended for packagings of variable sizes, which has an operation of continuous type.

Moreover, a task of the present invention is to make available a pre-assembly station which, owing to the advantages introduced, maintains as much as possible the functionalities of the prior art.

Finally, a task of the present invention is to make available a station, a plant and a method for the pre-assembly of boxes of variable sizes that are particularly advantageous with respect to the prior art.

These and other objects and tasks of the present invention are achieved by a station, a plant and a method in accordance with the appended claims. Further characteristics are identified in the dependent claims. All appended claims form an integral part of the present disclosure.

In accordance with a first aspect, the invention concerns a pre-assembly station of boxes of variable sizes, configured for receiving in input flat blanks representing the plane development of at least two boxes of different sizes and for releasing in output preassembled boxes. The pre-assembly station comprises:

- a worktable having a width and a length, wherein the worktable is configured for receiving and supporting a flat blank with a predetermined orientation;

- two folding elements, movable in the direction w of the width of the worktable; and

- pushing means configured for pushing the flat blank toward the folding elements, through the folding elements, and beyond, in the direction I of the length of the worktable.

Furthermore, in the station of the invention, each of the folding elements comprises a helical screw surface developing around a longitudinal axis a, parallel to the direction 1.

The pre-assembly station of the invention, with a very simple structure, allows to solve the problems of the prior art, in particular it is characterized by a semi-discrete to continuous operation and is suitable for use in fully automatic plants but also in semiautomatic plants that allow to handle all types of items, including the fragile, perishable or potentially dangerous ones.

Preferably, the station further comprises an electronic control unit configured for controlling the actuation of one or more of the elements of the station itself. The presence of the electronic control unit allows the operation of the pre-assembly station to be automated at various levels, even fully.

Preferably, the pushing means imposes a relative translation movement on the flat blank with respect to the folding elements and the folding elements, once positioned in the direction w, remain stationary during the interaction with the flat blank.

The folding elements have a very simple structure and, apart from the possibility of being translated in the direction of the width, they are static elements that do not introduce any complications in the system.

Preferably the folding elements are mounted on motorized translating supports, configured for being actuated by the electronic control unit.

Preferably the station further comprises pressure elements adjacent to a proximal portion of the folding elements.

Preferably the pushing means comprise actuators or motors configured for being actuated by the electronic control unit.

In some embodiments, the station further comprises abutments for the correct positioning of the flat blank with respect to the direction w. Preferably each abutment is mounted on a translating support, so as to be able to translate in the direction w. Advantageously, the translating support is motorized and is configured for being actuated by the electronic control unit.

In some embodiments, the station further comprises a dispenser of joining means. Preferably the dispenser is mounted on a translating support, so as to able to translate in the direction w. Advantageously, the translating support is motorized and is configured for being actuated by the electronic control unit.

Preferably in the station of the invention, each of the folding elements further comprises a flat surface parallel to the worktable and, at a distal end of the folding element, the helical screw surface is substantially parallel to and superimposed on the flat surface. Furthermore, the folding element is preferably configured so as to allow the adjustment of the distance between the flat surface and the helical screw surface superimposed thereon.

The possibility of adjusting the distance between the flat surface and the helical screw surface makes it possible to use the same folding elements with flat blanks obtained from materials of different thickness. In accordance with some embodiments, the helical screw surface of the folding element is continuous.

Such a structure of the folding element allows to obtain a particularly robust helical screw surface and to maximize the surface on which the stresses are distributed.

In accordance with some embodiments, the helical screw surface of the folding element is discrete and/ or discontinuous, obtained by juxtaposing linear guides.

Such a structure of the folding element makes it possible to obtain a helical screw surface that is particularly easy to achieve.

In accordance with a second aspect, the invention concerns a plant for manufacturing boxes of variable sizes. The plant comprises:

- a cutting station configured for cutting out of a sheet of packaging material at least two flat blanks representing the plane development of two boxes of different sizes; downstream of the cutting station, a pre-assembly station configured for receiving in input the flat blanks and for releasing in output pre-assembled boxes;

- in parallel with the pre-assembly station, a station for providing bulk items; downstream of the pre-assembly station and of the station for providing bulk items, a packaging station configured for receiving in input pre-assembled boxes and bulk items and for releasing in output assembled boxes containing items.

In the plant of the invention, the pre-assembly station is in accordance with what is described above.

In accordance with a third aspect, the invention concerns a method for manufacturing boxes of variable sizes. The method of the invention comprises the steps of:

- providing a pre-assembly station in accordance with what is described above;

- providing a flat blank representing the plane development of a box, wherein the flat blank comprises two folding axes ;

- laying down the flat blank on the worktable of the pre-assembly station with a predetermined orientation;

- aligning the folding elements of the pre-assembly station with the folding axes /of the flat blank; and

- pushing the flat blank toward the folding elements, through the folding elements, and beyond.

Preferably in the method of the invention, the step of aligning the folding elements with the folding axes / of the flat blank comprises the step of making the longitudinal axes a of the folding elements coincident with the folding axes /of the flat blank.

Further features and purposes of the present invention will become more evident from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below with reference to some examples, provided for explanatory and non-limiting purposes, and illustrated in the annexed drawings. These drawings illustrate different aspects and embodiments of the present invention and reference numerals illustrating structures, components, materials and/ or similar elements in different drawings are indicated by similar reference numerals, where appropriate. Moreover, for clarity of illustration, certain references may not be repeated in all drawings.

Figure 1 represents a block diagram of the plant in accordance with the invention;

Figure 2 schematically represents the flat blank RSC of a box;

Figure 3 schematically represents the flat blank of Figure 2 during the preassembly of the box;

Figure 4 schematically represents the pre-assembled box obtained from the flat blank of Figures 2 and 3, in the collapsed state;

Figure 5 schematically represents the pre-assembled box of Figure 4, in the expanded state;

Figure 6 schematically represents the assembled box of Figure 4;

Figure 7 is a plan view of a pre-assembly station in accordance with the invention;

Figure 8 is a side view of the pre-assembly station of Figure 7;

Figure 9 is a front view of the pre-assembly station of Figure 7;

Figure 10 is an axonometric view of the pre-assembly station of Figure 7; Figure 11 is an axonometric view of a pre-assembly station in accordance with the invention;

Figure 12 is an axonometric view of a pre-assembly station in accordance with the invention;

Figure 13 is an enlarged view of the detail indicated with XIII-XIII in Figure 12;

Figure 14 is a schematic axonometric view of a folding element of the pre-assembly station in accordance with the invention;

Figure 15 is another schematic axonometric view of the folding element of Figure 14;

Figure 16 is a schematic plan view of the folding element of Figure 14;

Figure 17 is a schematic view of the section operated along the trace XVII-XVII of Figure 16;

Figure 18 is a schematic view of the section operated along the trace XVIII-XVIII of Figure 16; and

Figure 19 is a schematic view of the section operated along the trace XIX-XIX of Figure 16;

Figure 20 is a schematic view of the section operated along the trace XX -XX of Figure 16;

Figure 21 is a schematic axonometric view of another folding element of the preassembly station in accordance with the invention;

Figure 22 is another schematic axonometric view of the folding element of Figure 21;

Figure 23 is a schematic side view of the folding element of Figure 21;

Figure 24 is a schematic view of the section operated along the trace XXIV -XXIV of Figure 23;

Figure 25 is a schematic view of the section operated along the trace XXV -XXV of Figure 23; and

Figure 26 is a schematic view of the section operated along the trace XXVI-XXVI of Figure 23; Figure 27 is a schematic view of the section operated along the trace XXVII-XXVII of Figure 23;

Figure 28 is a schematic view of the section operated along the trace XXVIII-XXVIII of Figure 23; and

Figure 29 is a schematic plan view of an embodiment of the plant of the invention.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications and alternative constructions, certain preferred embodiments are shown in the drawings and are described hereinbelow in detail. It must in any case be understood that there is no intention to limit the invention to the specific embodiment illustrated, but, on the contrary, the invention intends covering all the modifications, alternative and equivalent constructions that fall within the scope of the invention as defined in the claims.

The description deals in detail with the peculiar aspects and the technical characteristics of the invention, while the aspects and the technical characteristics per se known can only be hinted at. In these respects, what is reported above with reference to the prior art remains valid.

The use of "for example", "etc.", "or" indicates non-exclusive alternatives without limitation, unless otherwise indicated. The use of "comprises" and "includes" means "comprises or includes, but not limited to", unless otherwise indicated.

The invention is intended to operate in the presence of acceleration of gravity g which uniquely defines the vertical direction and the horizontal directions perpendicular thereto. In the discussion that follows, it is also considered that the acceleration of gravity g uniquely defines the terms "above", "upper", "high" and the like, with respect to the terms "below", "lower", "low" and the like.

The invention concerns the pre-assembly of boxes 30 starting from flat blanks 32 representing the plane development thereof. In order to better understand the invention, it is good to briefly describe the type of the flat blanks 32 for which the pre-assembly station 50 has been configured. The steps necessary to obtain a box 30 (or packaging) starting from such flat blanks 32 are also described.

In the following discussion, flat blanks 32 are considered intended to make boxes 30 of cuboid shape and consisting of a single continuous element. The continuous element is intended to constitute, by means of subsequent folds, all the walls of the box 30. With reference to Figure 2, the continuous element comprises six slots 34 aligned with each other two by two and, at one end, a joining fin 36 (or manufacturer's edge) intended to be joined to the opposite end. The bottom (lower wall) and the ceiling (upper wall) of the box 30 are obtained by closure flaps 38 which constitute extensions of the side walls 40 and which are separated from each other by the slots 34.

For simplicity's sake, a number of conventions are adopted below with reference to Figure 2. The side walls 40 are counted and numbered starting from the one comprising the joining fin 36. In addition, the flat blank 32 is considered with the joining fin 36 protruding to the left. In this way the lower closure flaps 38i are intended to form the bottom of the box 30, while the upper closure flaps 38s are intended to form the ceiling of the box 30. As the skilled person can well understand such conventions are intended only to make the description smoother and nothing would change if different conventions were adopted, for example contrary.

The particular type of flat blank 32 shown in Figure 2 is the one defined based on the well-known RSC standard (Regular Slotted Container). In this particular case all the closure flaps 38 have the same length, from the fold to the edge. Thus the closure flaps 38 that extend from the long sides meet in the middle, while the closure flaps 38 that extend from the short sides do not meet (see for example Figure 6). Because of the equal length of the closure flaps 38, the blank RSC appear as a large rectangle comprising the six slots 34 aligned with each other two by two, and from which the joining fin 36 protrudes. In other types of flat blanks 32, the closure flaps 38 may have different lengths from each other, measured from the fold to the edge. In this case such flat blanks 32 do not follow the RSC standard but can still be processed by the pre-assembly station 50 of the invention.

Each of the flat blanks 32 intended to be processed in the pre-assembly station 50 of the invention defines two initial folding axes f. A first folding axis passes between the first side wall 40i and the second side wall 402, along the slots 34 closer to the joining fin 36. The second folding axis passes between the third side wall 40s and the fourth side wall 404, along the opposite slots 34, those farthest away from the joining fin 36.

A first step of pre-assembly of the box 30 starting from the flat blank 32 envisages folding the first side wall 40i and the respective closure flaps 38 around the first folding axis i, toward the second side wall 40? (see Figure 3). A second step of pre-assembly of the box 30 envisages folding the fourth side wall 404 and the respective closure flaps 38 around the second folding axis fi, toward the third side wall 40s. In this way, the fourth side wall 404 overlaps the joining fin 36 (see Figure 4). A further pre-assembly step is to provide joining means 42, for joining the joining fin 36 to the fourth side wall 404. The joining means 42 may be one or more of glue, adhesive tape, double-sided tape, metal staples, and the like. For example, Figure 3 schematically shows an adhesive strip (e.g., glue or double-sided tape) arranged on the joining fin 36 prior to folding the fourth side wall 404.

Once the fourth side wall 404 is joined to the joining fin 36, the pre-assembled box 30 is obtained in a collapsed configuration (Figure 4). In this configuration the box 30 has the structural continuity of the side walls 40 but must be closed at the upper and lower ends. To conclude the assembly of the box 30 it is therefore necessary to space the side walls 40 from each other, so that they are perpendicular two by two (Figure 5) and it is still necessary to fold the closure flaps 38i intended to constitute the bottom of the box 30 (Figure 6). Also in this case, in a manner known per se, it is necessary to provide joining means 42 such as glue, adhesive tape, double-sided tape, metal staples and the like.

In accordance with a first aspect, the invention concerns a pre-assembly station 50 for boxes 30 (or packagings) of variable sizes. The pre-assembly station 50 of the invention is configured for receiving in input flat blanks 32 representing the plane development of at least two boxes 30 of different sizes and for releasing in output pre-assembled boxes 30, the pre-assembly station 50 comprises:

- a worktable 44 having a width and a length, wherein the worktable 44 is configured for receiving and supporting a flat blank 32 with a predetermined orientation;

- two folding elements 46, movable in the direction w of the width of the worktable 44; and

- pushing means 48 configured for pushing the flat blank 32 toward the folding elements 46, through the folding elements 46 and beyond, in the direction I of the length of the worktable 44.

In addition, each of the folding elements 46 comprises a helical screw surface 54 developing around a longitudinal axis a, parallel to the direction I.

With reference to the block diagram of Figure 1, the pre-assembly station 50 defines an inlet and an outlet, spaced apart along the direction I of the length. The preassembly station 50 is in fact configured for receiving in input flat blanks 32, one at a time, and for releasing in output pre-assembled boxes 30 in a collapsed configuration. Below the direction I is also considered oriented from the inlet to the outlet. Further, within the pre-assembly station 50, a position relatively close to the inlet is called proximal, while a position relatively close to the outlet is called distal. Preferably the pre-assembly station 50 comprises an electronic control unit 51 configured for controlling the actuation of one or more of the elements of the station itself, as will be better described below. The electronic control unit 51 may be dedicated to the pre-assembly station 50 only or, more preferably, may be configured for controlling the entire plant 100.

The worktable 44 may be defined by a real substantially continuous surface, such as for example in the embodiment of Figure 11, or by a plurality of longitudinal elements arranged along the direction I and spaced apart from each other along the direction w, such as for example in the embodiments of Figures 7-10 and 12-13. When intended as a geometric entity, the worktable 44 is also called a plane wl.

The predefined orientation with which the flat blank 32 is intended to be laid down on the worktable 44 must ensure the correct cooperation of the flat blank 32 itself with the pre-assembly station 50. In particular, the flat blank 32 must be arranged with the two folding axes arranged parallel to the direction I. Furthermore, the flat blank 32 must be positioned with the joining fin 36 protruding laterally in the direction w in a predetermined sense, for example to the left (see Figures 10, 11 and 12). Finally, the flat blank 32 must be arranged in a predefined position with respect to the direction w. This particular aspect of the positioning of the flat blank 32, and the technical features of the pre-assembly station 50 connected thereto, will be described in greater detail below.

Advantageously, the folding elements 46 are static elements, which have as their only possibility of movement the translation along the direction w. This translation also takes place in the preliminary steps, in preparation for the folding step, during which the folding elements 46 remain perfectly still with respect to the worktable.

A first embodiment of the folding elements 46 is described below with particular reference to Figures 14 to 20. Each of such folding elements 46 comprises a first substantially flat surface 52 and a second helical screw surface 54 (or helicoid). The flat surface 52 lies parallel to the worktable 44 (plane wl). The helical screw surface 54 develops around a longitudinal axis a, parallel to the direction I.

The two folding elements 46 of the pre-assembly station 50 have specular functions to each other, preferably they also have specular shapes to each other. Figures 14 to 20 show the left folding member 46. In such a left folding element 46, proceeding along I (thus from the inlet toward the outlet of the pre-assembly station 50) the helical screw surface 54 describes an arc of about 180°. At the proximal end of the folding element 46, the helical screw surface 54 lies to the left of the flat surface 52, substantially coplanar and parallel thereto (see Figure 17). Proceeding in the direction I, the helical screw surface 54 shows a development that gradually rotates clockwise (see Figure 18 and 19). At the distal end of the folding element 46, the helical screw surface 54 returns to be substantially parallel to the flat surface 52, although inverted by 180° and superimposed thereon (see Figure 20).

As the skilled person can well understand, the right folding element 46 is in all respects analogous to the left one just described, except for having a specular function to it and therefore preferably also having a specular shape to it. In other words, even in such a right folding element 46, proceeding along the direction I, the helical screw surface 54 describes an arc of about 180°. At the proximal end, the helical screw surface 54 lies to the right of the flat surface 52, substantially coplanar and parallel thereto. Proceeding in the direction I, the helical screw surface 54 shows a development that gradually rotates counterclockwise to return to be, at the distal end, substantially parallel to the flat surface 52, although inverted by 180° and superimposed thereon.

At the distal ends of the folding elements 46, between the flat surface 52 and the helical screw surface 54 superimposed thereon there is a distance that is approximately equal to twice the thickness f of the packaging material, typically corrugated cardboard, with which the flat blanks 32 are made (see in particular Figure 20).

In accordance with some embodiments, the folding elements 46 are configured so as to allow, at least at the distal end, the adjustment of the distance between the flat surface 52 and the helical screw surface 54 superimposed thereon. In this way it is possible to use the same folding elements 46 with packaging materials having different thicknesses f.

Preferably the two folding elements 46 comprise, at the proximal end, an inclined lead-in ramp 56 to facilitate a smooth engagement of the flat blank 32.

A second embodiment of the folding elements 46 is described below with particular reference to Figures 21 to 28. Each of such folding elements 46 comprises a helical screw surface 54 (or helicoid). The helical screw surface 54 develops around a longitudinal axis a, parallel to the direction I. In this embodiment, the flat surface 52 described above is replaced by the worktable 44 (plane wl) of the pre-assembly station 50.

The two folding elements 46 of the pre-assembly station 50 have specular functions to each other, preferably they also have specular shapes to each other. Figures 21 to 28 show the left folding member 46. In such a left folding element 46, proceeding along I (thus from the inlet toward the outlet of the pre-assembly station 50) the helical screw surface 54 describes an arc of about 180°. At the proximal end of the folding element 46, the helical screw surface 54 lies to the left of the axis a, substantially coplanar and parallel to the worktable 44 (see Figure 24). Proceeding in the direction I, the helical screw surface 54 shows a development that gradually rotates clockwise (Figures 25, 26 and 27). At the distal end of the folding element 46, the helical screw surface 54 returns to be substantially parallel to the worktable 44, although inverted by 180° and superimposed thereon (see Figure 28).

As the skilled person can well understand, the right folding element 46 is in all respects analogous to the left one just described, except for having a specular function to it and therefore preferably also having a specular shape to it. In other words, even in such a right folding element 46, proceeding along the direction I, the helical screw surface 54 describes an arc of about 180°. At the proximal end, the helical screw surface 54 lies to the right of the axis a, substantially coplanar and parallel to the worktable 44. Proceeding in the direction I, the helical screw surface 54 shows a development that gradually rotates counterclockwise to return to be, at the distal end, substantially parallel to the worktable 44, although inverted by 180° and superimposed thereon.

At the distal ends of the folding elements 46, between the worktable 44 and the helical screw surface 54 superimposed thereon there is a distance that is approximately equal to twice the thickness f of the packaging material, typically corrugated cardboard, with which the flat blanks 32 are made (see in particular Figures 23 and 28).

Preferably the two folding elements 46 comprise, at the proximal end, a lead-in track 53 to facilitate a smooth engagement of the flat blank 32.

The folding elements 46 of the first embodiment (Figures 14 to 20) have a smaller development along the direction I than the folding elements 46 of the second embodiment (Figures 21 to 28). As the skilled person can well understand, a folding of equal amplitude, i.e. equal to 180°, obtained over a smaller distance imposes a greater effort on the packaging material of the flat blanks 32, typically corrugated cardboard. Thus the embodiment of Figures 14 to 20 is more suited to flat blanks 32 made of a relatively flexible material, which allows to be folded in a relatively abrupt manner. Otherwise, for flat blanks 32 made of a relatively rigid material it may be preferable to use folding elements 46 which impose the folding in a more progressive manner, thus similar to those of Figures 21 to 28.

Preferably the two folding elements 46 are not aligned in the direction I, but one of them is slightly closer to the inlet, while the other is slightly closer to the outlet. In particular, the folding element 46 closer to the inlet is the one placed on the side of the pre-assembly station 50 where it is envisaged that the joining fin 36 of the flat blank 32 is placed. In the embodiments shown in the accompanying figures, wherein the flat blank 32 is arranged with the joining fin 36 on the left, the left folding element 46 is closer to the inlet, while the right folding element 46 is closer to the outlet.

The two folding elements 46 are preferably mounted on translating supports, so as to be able to translate in the direction w. Even more preferably, the translating supports are motorized and can be actuated by the electronic control unit 51.

The pre-assembly station 50 is configured for imposing along the direction I a relative translation movement between the flat blank 32 and the folding elements 46. The pushing means 48 obtain this relative movement by imposing the translation of the flat blank 32 with respect to the folding elements 46 which, once positioned in the direction w, remain stationary during the interaction with the flat blank 32. As the skilled person can well understand, theoretically it would be possible to achieve the same result by holding the flat blank 32 still and by translating the folding elements 46. This second solution, however, appears less advantageous because the plant 100 as a whole requires in any case the movement of the flat blank 32 from the upstream stations toward the downstream stations and therefore the solution that imposes the movement to the flat blank 32 appears to be more efficient. In the case of the kinematic inversion, the flat blank 32 should still be removed and brought toward the outlet of the pre-assembly station 50, while the folding elements 46 should be subjected to an alternating movement along the direction I.

The helical screw surface 54 may define a regular helicoid or may define an irregular helicoid. More in detail, the helical screw surface 54 defines, for each section operated in a plane perpendicular to the axis a, a straight segment inclined with respect to the flat surface 52. The angle between the helical screw surface 54 and the flat surface 52 varies along the axis a such variation can be appreciated, for example, by comparing the sections of Figures 17 to 20 and the sections of Figures 24 to 28 with each other.

In accordance with some embodiments, such variation is uniform along the axis a; in other words, the angle comprised between the helical screw surface 54 and the flat surface 52 is a linear function of the position along the axis a. The helical screw surface 54 thus defines a regular helicoid.

In accordance with other embodiments, the angle variation is not uniform along the axis a; in other words, the angle comprised between the helical screw surface 54 and the flat surface 52 is a non-linear function of the position along the axis a. The helical screw surface 54 thus defines an irregular helicoid. For example, in some sections the angle variation may be slower and in other sections it may be faster. In other words, considering that the flat blanks 32 are pushed along the direction I at a constant speed, the angular variation of the helical screw surface 54 may impose a gentler fold in some sections (similar to what happens in the embodiment of Figures 21 to 28) and a more abrupt fold in other sections of the movement of the flat blanks 32 (similar to what happens in the embodiment of Figures 14 to 20).

In accordance with the embodiments shown in the accompanying figures, the helical screw surfaces 54 of the folding elements 46 are continuous. A continuous helical screw surface 54 suitable for the invention can be obtained by various construction technologies. For example, the continuous helical screw surface 54 can be obtained: by casting starting from a model; by machining by removal of material starting from the solid material; by deformation of a metal sheet, possibly cut into parts; by additive technologies, such as 3D printing or sintering.

In accordance with other embodiments (not shown), the helical screw surfaces 54 of the folding elements 46 may be discrete and/ or discontinuous, obtained for example by juxtaposing linear guides. Preferably, each of the linear guides develops along the direction I defining a helix around the longitudinal axis a.

Such an embodiment can greatly simplify the realization of the helical screw surface 54 since the deformation of each linear guide appears easier. Depending on the specific needs, the linear guides constituting the helical screw surface 54 may be placed into contact with each other (thus simulating a continuous surface) or may be spaced apart from each other (thus obtaining a discontinuous surface).

As the skilled person can well understand, similar choices are also available for the flat surface 52, although this is much easier to achieve.

In accordance with some embodiments, the surfaces 52 and 54 of the folding elements 46 comprise at least locally a coating suitable for facilitating the sliding of the material constituting the flat blanks 32. The coating may homogeneously cover the entire extent of the flat surface 52 and/ or of the helical screw surface 54, or it may be limited to the areas where the sliding of the flat blanks 32 produces greater effects due to friction, for example in terms of wear, abrasion, temperature rise, etc.

The coating may take the form of a thin film, for example deposited on the surfaces 52 and 54 as a paint, or it may take the form of thick inserts, applied as mechanical pieces. Preferably the coating may be made with a low friction coefficient material, such as for example bronze or Polytetrafluoroethylene (PTFE).

The pushing means 48 are configured for pushing the flat blank 32 toward the folding elements 46, through the folding elements 46 and beyond, along the direction /, in particular from the inlet toward the outlet of the pre-assembly station 50.

The pushing means 48 may take different forms depending on the specific needs. In accordance with some embodiments, the pushing means 48 comprise one or more pushers 58 moved by as many linear actuators, preferably placed below the worktable 44. Figures 7 to 10 show a pre-assembly station 50 comprising two pushers 58 arranged in parallel, while Figure 11 shows a pre-assembly station 50 comprising only one central pusher 58. The linear actuators, known per se, can be for example electric, pneumatic, or hydraulic, and can be chosen by the skilled person based on the specific needs.

In other embodiments, such as that of Figures 12 and 13, the pushing means 48 comprises a plurality of lower 60 and upper 62 motorized belts. The lower belts 60 define the worktable 44 and at the same time contribute to the translation of the flat blank 32. The upper belts 62 contribute to the translation of the flat blank 32.

In the embodiment of Figures 12 and 13 the thrust is transmitted from the belts 60, 62 to the flat blank 32 mainly by means of appendages 64 protruding from the belts themselves, in particular from the upper belts 62 (see in particular Figure 13). In such an embodiment, the eight lower belts 60 are spaced apart from each other in the direction w, thus forming longitudinal slits 66 in the worktable 44, also for the purpose of accommodating the appendages 64 protruding from the upper belts 62.

In other embodiments, the thrust may be transmitted from the belts 60, 62 to the flat blank 32 simply by friction; in this case it is preferable that the belts 60, 62 apply a pressure to the flat blank 32 in a direction perpendicular to the plane wl. In these embodiments the longitudinal slits 66 are not necessary and therefore the worktable 44 can be defined by a single lower belt 60 of suitable width.

In the event that the pushing means 48 provide for the action of multiple elements on the flat blank 32 (for example two pushers 58 like in Figure 10 or two appendages 64 like in Figure 12), it is important that they are synchronized in the movement, so as not to induce an undesired rotation of the flat blank 32 in the plane wl. For example, the synchronization can be ensured mechanically or electronically by means of the electronic control unit 51.

Regardless of the type, therefore, the pushing means 48 comprise actuators or motors, and it is preferable that such actuators or motors can be actuated by the electronic control unit 51.

In accordance with some embodiments in which the pushing means 48 provide for the action of multiple elements on the flat blank 32, it is preferable that the pushing means 48 are mounted on translating supports, so as to be able to translate in the direction w. Even more preferably, the translating supports are motorized and can be actuated by the electronic control unit 51.

Preferably, the pre-assembly station 50 further comprises abutments 68 for the correct positioning of the flat blank 32 with respect to the direction w. In some embodiments, the abutments 68 may simply be optical references. In other embodiments, such as for example that of Figures 7-10, the abutments 68 comprise side resting surfaces that allow a unique position for the flat blank 32 to be defined.

Each abutment 68 is preferably mounted on a translating support, so as to be able to translate in the direction w. Even more preferably, the translating support is motorized and can be actuated by the electronic control unit 51.

Preferably the pre-assembly station 50 further comprises pressure elements 70, adjacent to a proximal portion of the folding elements 46. Preferably, the pressure elements 70 are superimposed on a proximal portion of the flat surface 52 of the folding elements 46 or on a portion of the worktable 44. Preferably the pre-assembly station 50 comprises a right pressure element 70, located immediately to the left of the axis a of the right folding element 46, and a left pressure element 70, located immediately to the right of the axis a of the left folding element 46. Between the flat surface 52 or the worktable 44, on the one hand, and the lower surface of the pressure element 70 superimposed thereon, on the other hand, there is a distance that is approximately equal to the thickness f of the packaging material, typically corrugated cardboard, with which the flat blanks 32 are made.

In the embodiments of Figures 10-13, the pressure elements 70 take the form of skids. In other embodiments they may take different forms, such as for example advantageously idle belts or arrays of rollers.

Preferably the pressure elements 70 are fixed with respect to the folding elements 46 and translate rigidly together with them in the direction w. Alternatively, the folding elements 46 can also be mounted on their own translating supports, so as to be able to translate in the direction w. In this case it is preferable that the translating supports are motorized and that they can be actuated by the electronic control unit 51.

Preferably the pre-assembly station 50 further comprises a dispenser of joining means 42 (not shown), configured for arranging the joining means 42 between the joining fin 36 and the fourth side wall 40, once they are folded. This dispenser can take different forms, all per se known in the sector, depending on the type of the joining means 42 that is adopted in the pre-assembly. For example, the dispenser may comprise a nozzle that distributes glue, a head that applies a double-sided tape, a stapler that applies metal staples, and so on.

Advantageously, with respect to the direction w, the dispenser must be aligned with the position where the joining fin 36 will be located once the first side wall 40i of the flat blank 32 has been correctly folded. To be positioned correctly, the dispenser is preferably arranged between the two folding elements 46 with respect to the direction w. Furthermore, in the case in which the joining means 42 are to be applied on the joining fin 36 before the fourth side wall 404 is folded on itself (see Figure 3), the dispenser is preferably arranged between the two folding elements 46 also with respect to the direction I. Preferably the dispenser is configured for being actuated by the electronic control unit 51.

Preferably the dispenser is mounted on a translating support, so as to able to translate in the direction w. Even more preferably, the translating support is motorized and can be actuated by the electronic control unit 51.

The operation of the pre-assembly station 50 in accordance with the invention is briefly described below. As mentioned above, the correct operation of the pre-assembly station 50 requires a precise positioning of the flat blank 32 with respect to all the elements of the station itself. This positioning can be carried out manually by an operator, but it is advantageous that it can be managed automatically, for example by the electronic control unit 51 configured for controlling the pre-assembly station 50 and/ or the entire plant 100.

Firstly, it is necessary that the flat blank 32 is arranged so that its folding axes are parallel to the direction I and that the joining fin 36 protrudes in the direction w on a predefined side, in the examples of the accompanying figures on the left side. It is then necessary to correctly align the flat blank 32 with respect to the folding elements 46. In particular, it is necessary to make the longitudinal axes a of the folding elements 46 coincident with the folding axes /of the flat blank 32. For this purpose, once the position of the flat blank 32 has been defined with respect to the direction w, for example by means of the abutments 68, it is possible to translate the two folding elements 46. This possibility of translation makes it possible to operate with flat blanks 32 of different sizes each time.

Once the longitudinal axes a of the folding elements 46 coincide with the folding axes /of the flat blank 32, it is possible to actuate the pushing means 48 in such a way as to push the flat blank 32 toward the folding elements 46, through the folding elements 46 and beyond, in a distal direction along I. During translation, the upper closure flap 38 of the first side wall 40i of the flat blank 32 (i.e. the wall from which the joining fin 36 protrudes) meets as first the respective folding element 46, in the example the left one. In particular, the upper closure flap 38s and then gradually the first side wall 40i and the lower closure flap 38i are brought by the lead-in ramp 56 into correct contact with the helical screw surface 54.

Shortly after, the upper closure flap 38s of the second side wall 40?, adjacent to the first side wall 40i, fits between the worktable 44 and the pressure element 70. During the translation in the distal direction of the flat blank 32, the helical screw surface 54 progressively lifts the first side wall 40i and imposes a clockwise rotation on it, while the second side wall 40? is kept adherent to the worktable 44 by the pressing element 70. At the outlet from the left folding element 46, the first side wall 40i has undergone a clockwise rotation by 180° around the folding axis , until it is completely folded over on the second side wall 40? (Figure 3).

The operation of the second folding element 46 (the right one, in the example) is identical and specular to that described above, and preferably takes place with a predetermined delay. Preferably, in fact, the arrangement of the two folding elements 46 is misaligned in the direction I, in order to first fold the side wall 40i of the flat blank 32 from which the joining fin 36 protrudes. In this way the joining fin 36 remains inside the assembled box 30.

Some types of joining means 42, such as glue and double-sided tape, require to be arranged on the joining fin 36 before folding the fourth side wall 404 of the flat blank 32. In this case it is advantageous that the dispenser of the joining means 42 is arranged between the two folding elements 46 with respect to the direction I, so that it can act on the joining fin 36 before the fourth side wall 404 is folded.

Other types of joining means 42, such as the metal staples and the adhesive tape, may also be provided after the fourth side wall 404 of the flat blank 32 has been folded on the joining fin 36. In this case it is advantageous that the dispenser of the joining means 42 is arranged downstream of the two folding elements 46 with respect to the direction I.

When the flat blank 32 exits the two folding elements 46, the first side wall 40i, with the joining fin 36, is completely folded over on the second side wall 40? and the fourth side wall 404 is completely folded over on the third side wall 40s, overlapping the joining fin 36 (Figure 4). Once the joining means 42 have been applied, the pre-assembled box 30 is thus obtained in a collapsed configuration, ready to be fed to the station downstream of the plant 100. In accordance with a second aspect, the invention concerns a plant 100 for manufacturing boxes 30 (or packagings) of variable sizes. A plant 100 in accordance with the invention is shown in the block diagram of Figure 1. The plant 100 of the invention comprises: a cutting station 72 configured for cutting out of a sheet of packaging material at least two flat blanks 32 representing the plane development of two boxes 30 of different sizes; downstream of the cutting station 72, a pre-assembly station 50 configured for receiving in input the flat blanks 32 and for releasing in output pre-assembled boxes 30;

- in parallel with the pre-assembly station 50, a station 74 for providing bulk items; and downstream of the pre-assembly station 50 and of the station 74 for providing bulk items, a packaging station 76 configured for receiving in input preassembled boxes 30 and bulk items and for releasing in output assembled boxes 30 containing items.

In the plant 100 of the invention, the pre-assembly station 50 is of the type described above.

The plant 100 for manufacturing boxes 30 of variable sizes can be a traditional plant 100 configured for manufacturing different predefined types of boxes 30, or it can be a plant 100 configured for operating according to the logic called BOD (Box On Demand).

Preferably the plant 100 comprises an electronic control unit 51 configured for controlling the actuation of one or more of the stations of the plant 100 itself.

Preferably the cutting station 72 is configured for cutting out of a sheet of packaging material (e.g. cardboard) at least two flat blanks 32 representing the plane development of boxes 30 of different sizes. The cutting station 72 is preferably automated and is configured for being controlled by the electronic control unit 51.

Preferably the plant 100 also comprises movement means configured for displacing, inside the stations or from one station to another, the flat blanks 32, the preassembled boxes 30, the bulk or grouped items, the assembled boxes 30 containing the items. The movement means are preferably automated and are configured for being controlled by the electronic control unit 51.

In accordance with some embodiments, the packaging station 76 is fully manual and is manned by an operator. In the packaging station 76, in fact, it is necessary to complete the assembly of the box 30, by folding the lower closure flaps 38i that constitute the bottom of the box 30, and to introduce the relative items into the box 30. The presence of an operator implies some advantages. In fact, the operator, in addition to clearly simplifying the packaging station 76, also makes it possible to manage fragile, perishable or potentially dangerous items that cannot be handled automatically.

In accordance with other embodiments, the packaging station 76 has a first automated substation and a second manual substation manned by an operator. In the first substation, the assembly of the box 30 is completed in an automated manner, by folding the lower closure flaps 38i that constitute the bottom of the box 30. In the second substation, the items of the relative order are manually introduced into the box 30. Also in this case the presence of the operator allows to manage the fragile, perishable or potentially dangerous items, while the presence of the first automated substation allows to lighten the operator's workload and to obtain higher processing speeds.

In accordance with still other embodiments, the packaging station 76 is fully automated. Both the completion of the assembly of the box 30 and the introduction of the items into the box 30 are carried out automatically. This allows for higher processing speeds to be obtained.

Preferably the plant 100 is of the type configured for providing, according to the BOD logic, a secondary packaging for a plurality of items forming an order. Preferably said plant 100 is of the type developed by the same Owner and described in the patent document entitled METHOD AND PLANT FOR MANUFACTURING A SECONDARY PACKAGING ACCORDING TO THE BOD LOGIC filed on the same date. A possible embodiment of such a plant is schematically represented in Figure 29. The plant 100 comprises in brief:

- an electronic control unit 51 comprising a memory module, an elaboration module, and control modules configured for providing instructions to the plant 100;

- a general storage 101 comprising a plurality of items;

- handling means configured for, on the basis of the instructions provided by the electronic control unit 51:

- taking items from the general storage 101; and

- grouping together the taken items so as to constitute a plurality of orders, - a standby storage 102 configured for maintaining the orders in standby;

- feeding means configured for making available a sheet of packaging material of predefined sizes, on the basis of the instructions provided by the electronic control unit 51;

- a cutting station 72 configured for cutting out of the sheet the flat blank 32 of a box 30 on the basis of the instructions provided by the electronic control unit 51, wherein the flat blank 32 is defined by the electronic control unit 51 in relation to a specific order;

- a pre-assembly station 50 configured for pre-assembling the box 30 starting from the cut flat blank 32;

- a packaging station 76; and

- movement means configured for, on the basis of the instructions provided by the electronic control unit 51, making available to the packaging station 76 the pre-assembled box 30 together with the related order.

In accordance with a third aspect, the invention concerns a method for preassembling boxes 30 of variable sizes. The method comprises the steps of:

- providing a pre-assembly station 50 in accordance with the invention;

- providing a flat blank 32 representing the plane development of a box 30, wherein the flat blank 32 comprises two folding axes ;

- laying down the flat blank 32 on the worktable 44 of the pre-assembly station 50 with a predetermined orientation;

- aligning the folding elements 46 of the pre-assembly station 50 with the folding axes / of the flat blank 32; and

- pushing the flat blank 32 toward the folding elements 46, through the folding elements 46 and beyond, in the direction I of the length of the worktable 44.

The flat blank 32 is of the type described above representing the plane development of a box 30 or packaging. Preferably, the step of aligning the folding elements 46 with the folding axes /of the flat blank 32 comprises the step of making the longitudinal axes a of the folding elements 46 coincident with the folding axes /of the flat blank 32. Even more preferably said step comprises translating the folding elements 46 with respect to the direction w of the width of the worktable 44. Preferably the step of pushing the flat blank 32 toward the folding elements 46, through the folding elements 46 and beyond is carried out by means of the pushing means 48.

Preferably the method further comprises the step of providing joining means 42 between the joining fin 36 and the opposite side wall 40 of the flat blank 32 (the fourth side wall 404 in the convention adopted).

The pre-assembly method described above makes available, one by one, preassembled boxes 30 in a collapsed configuration. Preferably said method is comprised in a more general packaging method comprising the steps of:

- providing the pre-assembled box 30 in a collapsed configuration;

- spacing the side walls 40 of the pre-assembled box 30 from each other, so that they are perpendicular two by two; and

- folding the lower closure flaps 38i intended to constitute the bottom of the box 30.

Preferably the packaging method also comprises the further step of introducing one or more bulk items into the box 30.

In light of the above, the skilled person can well understand that the invention overcomes the drawbacks highlighted in relation to the prior art.

In particular, the present invention makes available a pre-assembly station 50 intended for packagings of variable sizes, which can be integrated into a plant 100, possibly semi-automatic, suitable for handling all types of items, including the fragile, perishable or potentially dangerous ones.

Furthermore, the present invention makes available a pre-assembly station 50 intended for packagings of variable sizes, which has an operation of continuous type. In light of the above description, it will in fact be clear to the skilled person that, in the preassembly station 50, the flat blanks 32 are continuously made to slide from the inlet to the outlet, with the sole care of correctly positioning the folding elements 46.

Moreover, the present invention makes available a pre-assembly station 50 which, together with the advantages introduced, maintains as much as possible the functionalities of the prior art.

Finally, the present invention makes available a station, a plant 100 and a method for pre-assembling boxes 30 of variable sizes particularly advantageous with respect to the prior art.

In conclusion, all the details can be replaced by other technically equivalent elements; the characteristics described in relation to a specific embodiment can also be used in the other embodiments; the materials used, as well as the contingent shapes and sizes, can be any according to the specific implementation needs without leaving the scope of protection of the following claims.