WO2015079342A1

WO2015079342A1 - Machine and method for covering boxes.

Info

Publication number: WO2015079342A1
Application number: PCT/IB2014/065334
Authority: WO
Inventors: Mauro Mazzinghi; Marco MENICHETTI
Original assignee: Emmeci S.P.A.
Priority date: 2013-11-29
Filing date: 2014-10-15
Publication date: 2015-06-04
Also published as: ITBO20130661A1

Abstract

A machine for covering boxes using pre-glued paper blanks (2), comprising: a vertically mobile plate (8) for supporting a base (2b) of the blank (2) and the box (1); means for folding sides (3, 4) of the blank (2); means for folding upper flaps (3b, 4b) of the sides (3, 4) towards the inside of the box and in contact with inner faces of the side walls of the box; contact plates (18, 19) positioned outside the box to prevent an outward movement of the corresponding side walls of the box positioned in contact with them; presser elements (20, 21), mobile relative to the corresponding contact plates for translating along a horizontal line (DR) parallel with the base of the box, and insertable in the box for moving inside the box towards the corresponding contact plates and parallel with them, for pressing the side walls of the box interposed between the contact plates and the corresponding presser elements.

Description

DESCRIPTION

MACHINE AND METHOD FOR COVERING BOXES.

Technical field

This invention relates to a machine and a method for covering a box.

Background art

The technical field of this invention is that of industrial processing for covering boxes having a bottom wall and a side wall with a plurality of sides, in particular four sides.

The boxes in question are made from shaped sheets of paper or cardboard, known as forming blanks.

In particular, the boxes are formed from flat blanks consisting of a base and a plurality of faces connected to the base and which can be folded relative to the base to constitute a side wall of the box.

As regards the industrial process which produces the finished box, it should noticed that said process comprises two separate steps: a step of forming the box and a subsequent step of covering the box by applying a covering sheet (that is to say, a cover) on it.

This invention particularly concerns the box covering step.

More precisely, within the scope of this invention, the box to be covered is a box with a bottom wall having a number of sides which, in general, is equal to or greater than three, but in particular is equal to four. Moreover, the box has as many side walls as the sides of the base of the box.

The covering sheets are in turn shaped sheets, which constitute covering blanks.

The covering blank is a flat blank with a base shaped like the bottom wall of the box and sides (that is to say, side portions) connected to the base and designed to be folded to cover the side wall of the box.

Examples of machines and methods for covering boxes are described, for example, in patent documents US1646563, US2241962, US2713813 or EP618066.

Box covering comprises the following steps.

Firstly, a layer of glue is applied to the covering blank.

Then, the box to be covered is rested on the covering blank previously glued (that is to say, pre-glued), in such a way that the bottom wall of the box adheres to the base of the covering blank.

At this point the assembly made up of the box and the covering blank coupled to it is received by the covering machine, and the actual covering process begins.

First, the sides of the covering blank are folded (from a horizontal position coplanar with the base to a vertical position) to cover the outside of corresponding side walls of the box.

It should be noticed that the sides of the covering blank have two flaps: a lower flap, which covers the outer face of the corresponding side wall of the box, and an upper flap, which extends upwards beyond the edge and is used for an upper fold over, that is to say, to cover the inner face of the same wall.

Folding of the sides of the covering blank occurs by moving the box vertically downwards, through an opening formed by contact elements, typically brushes or rollers. The folding is caused by the interaction between the moving box and the fixed contact elements.

For moving the box there is a mould, which consists of a body whose purpose is to form a constraining element operatively fitted to size in a space inside the box.

The mould is connected to a rod for moving the mould and the box coupled to it.

It should be noticed that the covering blank is shaped so that the sides have a length greater than the length of the corresponding side walls of the box.

In that way, when the sides of the covering blank are folded and adhering to the side wall of the box, each panel comprises a portion (hereinafter referred to as the upper flap) which extends upwards beyond the edge of the corresponding side wall of the box.

The purpose of these upper flaps of the covering blank is to cover the upper free edge of the box and at least a portion of the inner surface of the side wall of the box.

Therefore, when folding of the sides of the covering blank is complete, the upper flap of each side of the covering blank is folded over inside the box, from a vertical position to a horizontal position (parallel with the base). That folding of the upper flaps from a vertical position to a horizontal position is performed by folding elements (for example small blades with horizontal orientation) mobile towards the box until they penetrate inside it, positioned above the box close to the upper edge of the box.

It should be noticed that, according to the prior art, segments projecting laterally from the panels of the covering blank are also folded; this operation is called lateral fold over.

Said partial inner covering (known also as "inner fold over" or "upper fold over") may be more or less "deep", according also to the type, the geometrical shape and the planned use of the box. In particular, the depth of the fold over is determined by the length of the fold over segments, compared with the height of the respective face of the side wall of the box to be covered.

Said internal fold over is performed in two steps, as follows.

Starting from a configuration in which the mould is removed from the box, in a first sub-step the vertically projecting upper flaps are folded at a right angle, towards the inside of the box, by a plurality of said folding elements.

In a subsequent step, the segments which are horizontal are further folded through another right angle, to make them adhere to the inner face of the wall of the box. That is done by moving the mould vertically downwards, in such a way that it is synchronised with a movement of the folding elements away from the box, to prevent it from interfering with them.

In short, the mould is raised and then lowered again towards the inside of the box for allowing further folding of the upper flaps.

However, prior art covering machines have several limits and disadvantages, in terms of various aspects.

As regards the upper fold over, there are two main problems.

A first problem relates to the need to perform the fold over without the folded segments soiling with glue; this would adversely affect the appearance of the box.

In prior art solutions, the fold over segments are generally soiled with glue as, during the folding, the ends of adjacent segments (that is, associated with consecutive faces of the box) interfere with each other, that is, they touch.

In fact, as mentioned previously, the blank is pre-glued to allow its adhesion to the box; therefore, during folding the laterally facing edges of the various segments touch each other before closing towards the inside of the box: this determines a possible transfer of glue onto the part of the segments in view.

The presence of these traces of glue in view adversely affects the quality and the appearance of the box, especially if the box is to be used to hold high quality products.

In addition, this makes another quality control on the boxes necessary and, possibly, additional cleaning inside the box which, in effect, increases the production times and the final cost of the boxes.

A second problem relates to the depth of the fold over.

In fact, in order to improve the appearance of the box, it is necessary to maximise the portion of the inner surface of the side wall of the box affected by the fold over (that is to say, covered).

This, naturally, translates into the need to increase the height of the fold over segments, or of the upper flaps of the sides of the covering blank. However, this involves limitations and difficulties due to the need to move the box and to hold it still in the fold over station; in fact, this need results in the presence of structures (for example the mould inserted in the box), positioned in the space inside and above the box, which are designed to move and stop the box.

These structures constitute geometrical constraints on the maximum permissible height of the upper fold over segments, since the segments must not, during folding (which causes rotation of the segments around the upper edges of the box) interfere with said structures.

In contrast, there is a need to cover boxes completely or partly even on the inner faces of the side walls.

Moreover, prior art covering machines cannot meet the need of obtaining an effect of softness to the touch of the side walls of the box, called the "cushion effect".

Disclosure of the invention

Therefore, the aim of this invention is to provide a machine and a method for covering boxes which overcome the above mentioned disadvantages of the prior art.

In particular, the aim of this invention is to provide a machine and a method for automatically covering a box using a pre-glued covering blank, allowing boxes to be obtained which are particularly soft to the touch, creating a "cushion effect" on the side walls of the box.

Another aim of this invention is to provide a machine and a method for automatically covering a box using a pre-glued covering blank, allowing boxes to be made in which the covered portion of the inner surface of the side wall is particularly large, as well as being particularly well-finished from an aesthetic viewpoint.

Another aim of this invention is to provide boxes which are well-finished and free of aesthetic defects in the inner zone of the covered side wall, allowing rapid execution and therefore high productivity.

These aims are fully achieved by the machine and method forming the subject matter of this invention as characterised in the appended claims.

In particular, the machine according to the invention is a machine for covering paper or cardboard boxes using pre-glued paper blanks having a plurality of sides which are joined to a base.

To move the box along a vertical path, the machine comprises a vertically mobile plate designed to support the base of the blank with the box coupled to it.

Preferably, the machine also comprises a bracket designed to be positioned resting on the base of the box and operating in conjunction with the plate to hold the base of the box interposed there (the plate is positioned below and the bracket above the base of the box).

Preferably, the plate is motor-driven and is connected to a control unit, for moving the box along a vertical path, between positions at predetermined heights. Alternatively, the bracket could be motor-driven and the plate passive (for example, connected to a return spring); or both the bracket and the plate could be motor-driven.

According to the disclosure, for pressing the side walls of the box when covering is complete, the machine comprises:

- contact plates, positioned outside the box to prevent an outward movement of the corresponding side walls of the box positioned in contact with them;

- presser elements, mobile relative to the corresponding contact plates for translating along a horizontal line parallel with the base of the box, and insertable in the box for moving, inside the box, towards the corresponding contact plates and parallel with them, for pressing the side walls of the box interposed between the contact plates and the corresponding presser elements.

Therefore, the machine according to the invention has no mould inside the box and the side walls of the box are pressed from the inside out, against contact plates positioned outside the box.

This allows pressing which is particularly precise and causes little trauma to the box, allowing air to be kept trapped between the side walls of the box and the flaps of the sides of the covering blank, to create the desired soft effect.

According to another aspect of this disclosure, the machine comprises a plurality of multi-function operating units (one for each side wall of the box).

Each of said operating units is designed to perform the following functions, relative to the corresponding side of the covering blank: folding of the side of the blank into a vertical position with the lower flap in contact with the corresponding side wall of the box; folding of the upper flaps of the side of the blank towards the inside of the box from an upright position to a horizontal position; folding of said upper flap of the side of the blank so that it is in contact with the inner face of the corresponding side wall of the box; pressing of the side wall of the box.

It should be noticed that, in general, the box to be covered has four side walls, two lateral and two end; but that does not limit the scope of the invention, which applies to boxes with any number of sides.

Each (multi-function) operating unit comprises one of the contact plates and one of the presser elements, which can be moved away from and towards one another, like the jaws of grippers, but remaining parallel with each other and relative to the side walls of the box.

Preferably, the operating units are positioned at two (or more) different heights, forming two (or more) pressing stations positioned at said different heights.

Preferably, there are (at least) two pressing stations. Each pressing station has a pair of operating units, in which the contact plates of the pair of operating units are positioned parallel with and opposite one another.

That allows complete processing (complete with all of the functions listed above, including pressing) for a pair of opposite sides of the covering blank on corresponding side walls of the box, and, at a later stage and in a different position, allows the same complete processing to be carried out for the other pair of opposite sides of the covering blank on corresponding side walls of the box. This makes the machine fast and precise and facilitates size change- overs, since it allows the contact plates to be sized for a maximum width of the side walls of the box, without the contact plates acting on adjacent side walls of the box interfering with each other due to a problem with their dimensions.

Preferably, the relative vertical movements between the box and the operating units are performed by moving the box (by means of the plate or if necessary the bracket).

That allows particularly precise machine operation.

In contrast, the contact plates can move horizontally towards and away from the vertical path of the box.

The presser elements move horizontally relative to the corresponding contact plates, towards and away from the vertical path of the box.

Preferably, each contact plate is positioned at the same height as and opposite the corresponding presser element.

In light of this, the control unit is programmed to control an actuator designed to move the box vertically and one or more actuators designed to move the presser elements relative to the corresponding contact plates, for controlling, in a synchronised fashion, a movement of at least one of the presser elements away from the corresponding contact plate, to form between them a gap for inserting a corresponding side wall of the box, and a lifting of the box, from a height lower than that of said contact plate, for bringing it to the height of the contact plate, with the corresponding wall inserted in said gap.

Alternatively, the presser elements are assigned vertical movements relative to the contact plates.

It should be noticed that said insertion of the side wall of the box in the gap formed between the contact plate (outside the box) and the presser element (aligned with a plane inside the side wall of the box) causes the folding down of the upper flap of the side of the covering blank, until it is in contact with the inner face of the side wall of the box. Therefore, the presser element also performs that function of further folding of the upper flap.

Moreover, when the upper flap is positioned vertically extending above the box, the horizontal movement of the presser element, from the outside of the box towards the inside but always above the box, causes folding of the upper flap towards the inside of the box, from a vertical position to a horizontal position. Therefore, the presser element also performs that function of folding the upper flap from a vertical position to a horizontal position.

Moreover, in an operating configuration of folding of sides of the covering blank, the contact plate is in a position far from the vertical path of the box and the presser element is positioned in a plane outside the box but near to the corresponding side wall of the box. In that way, the presser element is designed to form a contact element interacting with the side of the blank during a downward movement of it, together with the box.

In light of this, preferably, each operating unit comprises a projection connected to the presser element and extending upwards and horizontally away from a vertical path of the plate.

That promotes folding of the side of the blank from a horizontal position to a vertical position, because it forms a guide for folding the side of the blank into the vertical position with the respective lower flap in contact with the corresponding side wall of the box.

Hence, the present disclosure regards a machine for covering paper or cardboard boxes using pre-glued paper blanks having a plurality of sides which are joined to a base.

The (covering) machine comprises:

- a vertically mobile plate designed to support the base of the blank with the box coupled to it;

- first folders for folding the sides of the blank (e.g. means for folding the sides of the blank) to arrange them in a vertical position with respective lower flaps in contact with corresponding side walls of the box; - second folders for folding upper flaps of the sides of the blank (i.e. means for folding upper flaps of the sides of the blank) towards the inside of the box, moving them from an upright position to a horizontal position;

- third folders for folding the upper flaps of the sides of the blank (i.e. means for folding the upper flaps of the sides of the blank) into contact with the inner faces of the corresponding side walls of the box;

- pressers (i.e. presser means), for each side wall of the box, for pressing towards one another the upper flaps and the lower flaps of the sides of the blank which are coupled respectively to the inner and outer faces of the wall.

The pressers comprise:

- contact plates positioned outside the box for preventing an outward movement of the corresponding side walls of the box positioned in contact with them;

- presser elements mobile relative to the corresponding contact plates for translating along a horizontal line parallel with the base of the box, and insertable in the box for moving inside the box towards the corresponding contact plates and parallel with them, for pressing the side walls of the box interposed between the contact plates and the corresponding presser elements.

Preferably, the presser elements and the corresponding contact plates are arranged on corresponding parallel planes.

Preferably, the presser elements are mobile towards and away from the corresponding contact plates by translation along directions which are perpendicular to said planes (on which the corresponding presser elements and contact plates are arranged).

The disclosure also provides a method for covering paper or cardboard boxes using pre-glued paper blanks having a plurality of sides which are joined to a base.

The method comprises a movement of the box coupled to the blank along a vertical path. Moreover, the method comprises the following steps:

- folding of the sides of the blank to arrange them in a vertical position with respective lower flaps in contact with corresponding side walls of the box;

- folding of upper flaps of the sides of the blank towards the inside of the box, to move them from an upright position to a horizontal position;

- further folding of the upper flaps of the sides of the blank until they are in contact with inner faces of the corresponding side walls of the box;

- pressing of the side walls of the box, by moving towards one another the upper flaps and the lower flaps of the sides of the blank, coupled respectively to the inner face and to the outer face of the walls.

According to the invention, the pressing step comprises, for each side wall of the box, a movement of the corresponding presser element, positioned inside the box and opposite the side wall, relative to the corresponding contact plate (which remains stationary during this step, so that it forms a stationary outer contact element), positioned outside the box in contact with the side wall, to prevent it from moving outwards.

The movement of the presser element occurs by translation along a horizontal line parallel with the base of the box and perpendicular to the contact plate and to the presser element.

It should be noticed that the presser element is preferably in turn plate- shaped.

Preferably, before the pressing step, the box is positioned at a height lower than at least one of the presser elements. Moreover, said at least one presser element is positioned in a forward position relative to the corresponding contact plate. Moreover, the box is moved relative to said at least one presser element vertically until a corresponding side wall of the box is interposed between the contact plate and the presser element opposite it, respectively on the outside and on the inside of the box.

Preferably, pressing takes place in at least two separate sub-steps, in corresponding pressing stations positioned at different heights.

This allows the pressing of side walls of the box which are adjacent to one another in different sub-steps, at different heights.

In light of this, preferably, even the steps of folding the sides of the blank, folding the upper flaps of the sides of the blank and further folding of the upper flaps occur in at least two corresponding separate sub-steps, with the box positioned at different heights.

In particular, a first sub-step of folding a pair of non-consecutive sides of the blank, a first sub-step of folding the upper flaps of said sides of the blank and a first sub-step of further folding of said upper flaps take place one after another, in a first station at a first height. Then, in a second station at a second height, corresponding second sub-steps take place one after another, relating to another pair of non-consecutive sides of the blank.

Brief description of drawings

These and other features will become more apparent from the following detailed description of a preferred, non-limiting embodiment of the invention, with reference to the accompanying drawings, in which:

- Figure 1 is a top plan view of an open covering sheet and a box positioned with its bottom wall on the sheet to be folded with the machine according to this invention;

- Figures 2 to 8 are schematic sides views with some parts cut away of a first sequence of steps carried out by a box covering machine according to this invention, for folding and for folding over a first pair of wings of the covering sheet for a pair of side walls of a box;

- Figures 9 to 1 1 are schematic front views with some parts cut away of a second sequence of steps carried out by the covering machine for folding opposite pairs of flaps of the sheet on two end walls of the box;

- Figures 12 to 19 are schematic side views with some parts cut away of a third sequence of steps carried out by the box covering machine for folding and for folding over a second pair of wings of the sheet for the two end walls of the box. Detailed description of preferred embodiments of the invention

With reference to the accompanying drawings, and in particular with reference to Figure 1 , the covering machine 100 according to this invention is used to cover cardboard boxes 1 with a covering sheet 2 in the form of an open paper blank provided with surfaces or stretches T treated with glue.

It should be noticed that glue is distributed on some parts of the blank 2 in a gluing station (not illustrated) upstream of the covering machine 100. Before reaching the covering machine 100, the box 1 is centred, that it so say, it is positioned with its bottom wall 1 a on the flat surface of the base 2b of the blank 2 in a centring station (not illustrated) so that it is in the configuration illustrated in Figure 1 .

It should be noticed that the structure of the blank 2 illustrated in the accompanying drawings is an example and does not limit the scope of the invention.

In particular, the term box 1 refers to a container having a plurality of side walls 1 b, 1 c, 1 d, 1 e which are connected to the bottom wall 1 a.

Said side walls 1 b, 1 c, 1 d, 1 e (and the bottom wall 1 a) each have an inner face and an outer face.

Moreover, each side wall 1 b, 1 c, 1 d, 1 e extends away from the bottom wall 1 a from a lower, connecting edge as far as an upper, free edge.

In this description particular reference is made, without thereby limiting the scope of the invention, to covering a box 1 which has a quadrilateral cross- section.

In particular, the box illustrated has a pair of end walls 1 c, 1 e (short) and a pair of sides 1 b, 1 d (long sides).

However, the machine 100 and the method described below may be applied to boxes having the most diverse geometries.

Moreover, preferably, the box 1 is made of cardboard, paperboard or the like. As indicated, the covering sheet 2 is a blank comprising a base 2b, preferably made of paper, defining a plurality of sides which are connected to each other, each being positionable opposite and couplable to a respective wall 1 b, 1 c, 1 d, 1 e of the box 1 . In light of this, it should be noticed that hereinafter reference is made to the "sheet 2" as well as to the "blank 2".

In this case, each side covers both faces (inner and outer) of the wall 1 b, 1 c, 1 d, 1 e of the box 1 , as described below.

In particular, the blank 2 in the flat configuration comprises four sides 3 and 4 and four segments 5, 6.

The four segments 5, 6 form a partial extension of two of the sides 3 of the blank 2 (in this case the covering sides 3 of the longer side walls) so as to make the covering complete and continuous on the four walls 1 b, 1 c, 1 d, 1 e (as indicated below).

The covering machine 100 comprises a horizontal surface 7 for movement of the blank 2 and the box 1 (with direction of feed A) positioned at a feed/unloading height Q0. It should be noticed that the box 1 was previously coupled to the blank 2, in the sense that the base 1 b of the box is positioned on a corresponding base face 2b of the blank 2.

The machine 100 comprises a (lower) retaining plate 8 for the blank 2 and the box 1 .

The plate 8 is mobile, in both directions, along a vertical path P for guiding the box 1 and the blank 2 along the path at different heights. Operatively, the movement of the plate 8 begins (and ends) from (at) the above- mentioned feed/unloading height Q0.

It should be noticed that the plate 8 is provided with suction means 9 (or other retaining means) for holding the blank 2 in a stable and centred position.

In light of this, the plate 8 is provided on its contact surface with holes 8b for allowing a vacuum to be generated for retaining the blank 2. The holes

8b are connected to a vacuum source 8c. Preferably, the plate 8 is connected to a movement cylinder 8a of an actuator 10 (schematically illustrated with a block) controlled by a control unit 1 1 of the machine 100.

Preferably, the machine 100 also comprises an (upper) counter-retaining bracket 12 positioned and mobile in terms of height again vertically and opposite the plate 8.

It should be noticed that the bracket 12 is positioned, in a home position, at a height which is higher than the above-mentioned feed/unloading height Q0.

The bracket 12 has a perimetric size which is less than the perimetric size of the bottom wall 1 a of the box 1 and is designed only for pressing the bottom wall 1 a of the box 1 against the plate 8.

Preferably, the bracket 12 is connected to a corresponding movement cylinder 13 of an actuator 14 (also schematically illustrated with a block) controlled by the above-mentioned control unit 1 1.

In light of this, continuously operating in conjunction with one another, the bracket 12 and the plate 8 guide the box 1 and the blank 2 along the vertical path P, for completely covering the box 1 according to the control modes managed and programmed by the control unit 1 1 .

The covering machine 100 comprises a first operating unit 15 for a first pair of wings/sides 3 of the blank 2 on a corresponding pair of walls 1 b, 1 d of the box 1 (in this example the long or lateral sides).

The first operating unit 15 is positioned along the vertical path P, at a (first) operating height Q1 which is lower than the feed/unloading height Q0 of the box 1 with the blank 2.

In light of this, the first operating unit 15 is designed to fold the first pair of wings 3 onto the outer surface and onto the inner surface of the corresponding walls 1 b, 1 d of the box 1 .

The covering machine 100 also comprises a second operating unit 16 for a second pair of wings/sides 4 of the blank 2 on a corresponding pair of walls 1 c, 1 e of the box 1 (in this example the short or end sides). The second operating unit 16 is positioned along the vertical path P, at a (second) operating height Q2 which is lower than the (first) operating height Q1 of the first operating unit 15.

The second operating unit 16 is designed to fold the second pair of wings 4 onto the outer surface and onto the inner surface of the corresponding (end) walls 1 c, 1 e of the box 1.

It should be noticed that the first operating unit 15 and the second operating unit 16 are positioned relative to each other along planes which are orthogonal to one another for intercepting the different wings 3, 4 of the blank 2.

Preferably, the first operating unit 15 and the second operating unit 16 have a length at least equal to the size of the corresponding walls 1 b, 1 c, 1 d, 1 e of the box 1 .

The covering machine 100 comprises a third operating unit (folding blades 17) for the two pairs of segments 5, 6 of the blank 2, arranged along the vertical path P and at a (third) operating height Q3 which is lower than the (first) operating height Q1 of the first operating unit 15 and higher than the (second) operating height Q2 of the second operating unit 16.

It should be noticed that the third operating unit is designed to fold the segments 5, 6 with the box 1 and the blank 2 moving, that is to say, during the descent of the box 1 and the blank 2 from the (first) operating height Q1 of the first operating unit 15 to the (second) operating height Q2 of the second operating unit 16.

The third operating unit comprises a pair of folding blades 17 for each pair of segments 5, 6.

The pairs of folding blades 17 are positioned and mobile parallel with the lying plane of the second operating unit 16.

Basically, the three operating units 15, 16, 17 virtually define the sides of a perimetric covering channel whose shape is similar to that of the box 1 and which extends vertically downwards.

It should be noticed that the first operating unit 15 and the second operating unit 16 are of similar construction and operating mode, therefore, other than the different reference characters, the description relating to the first operating unit 15 also applies to the second operating unit 16.

Each first and second operating unit 15 or 16 comprises a pair of opposite contact plates 18 or 19. Each contact plate 18, 19 has a vertical (reference) wall. Each one of the first and second operating unit 15 or 16 comprises a (corresponding) pair of presser elements 20 or 21 . Preferably, the presser elements 20, 21 are connected to the corresponding contact plates 18, 19. Each presser element 20, 21 is mobile between a first operating position, proximal to the respective plate 18 or 19, and a second operating position, distal to the respective plate 18 or 19 (and vice versa). It should be noticed that the movement of the presser elements 20 or 21 is along a line DR parallel with the base 1 a of the box 1 , in both directions. Preferably, the contact plates 18, 19 and the presser elements 20, 21 are arranged on corresponding, parallel planes; in particular, these planes are vertical, that is, parallel to the direction of movement of the plate 8.

The presser elements 20, 21 are mobile towards and way from the corresponding contact plates 18 or 19 along a direction which is perpendicular to those planes (along which the corresponding presser elements 20, 21 and contact plates 18 or 19 are arranged).

In light of this, each contact plate 18 or 19 is connected to movement units 22 in turn associated with a supporting frame (not illustrated) for moving the plate 18 or 19 along the horizontal line DR in both directions and at least between two operating positions: a first position near to the path P

(referring to the size of the box 1 ), and a second operating position away from the path P (referring to free transit of the box 1 and the blank 2 being processed), that is to say, with a centre-to-centre distance between the pairs of plates 18 or 19 which is greater than the size of the box 1 (described in detail below).

Each pair of contact plates 18 or 19 forms, at least in the first, near position, the reference of the two dimensions of the box 1 (maximum operating width - size - of the box 1 to be covered and maximum length of the box 1 to be covered).

In light of this, each pair of contact plates 18 or 19 is, therefore, adjustable in this first, near operating position, again in both directions and according to a trajectory transversal to the vertical path P, by means of the above- mentioned movement/adjusting means 22 depending on the size of the box 1 to be covered.

Also in light of this, each mobile element 20 or 21 is connected to movement means 23 or 24 (for example a hydraulic actuator) for reaching its operating positions.

Therefore, it should be noticed that the movement units 22 of the contact plate 18 or 19 and the movement means 23 or 24 of the mobile element 20 or 21 are coordinated with each other (by means of the control unit 1 1 ) for the movements of the corresponding components.

Each mobile element 20 or 21 is composed an (inverted) "L"-shaped arm 25 or 26 in which the vertical stretch forms a presser element 32 or 33 opposite the contact plate 18 or 19, whilst the horizontal stretch is directly connected to the actuator 23 or 24.

Moreover, each mobile element 20 or 21 comprises a projection 27 or 28 (guiding folder), extending from the presser element 25 or 26 with an arced shape, extending upwards until the free end reaches the feed/unloading height Q0, in the case of the first operating unit 15 (see Figures 2 to 8), and a folding start height Q2a in the case of the second operating unit 16 (see Figures 12 to 18).

The projection 27 or 28 has a vertical piece superposed on the outer surface of the presser element 25 or 26 and its subsequent pieces are set at angles to each other, without gaps, away from the vertical channel for configuring a lifting/erection path creating the folding for the corresponding sides 3 or 4 of the blank 2 towards the outer surfaces of the walls 1 b, 1 d or

1 c, 1 e of the box 1 . In other words, the projection 27 or 28 extends in an arc according to a trajectory moving away from the vertical perimetric channel so as to intercept the outermost edges of the sides 3 or 4 of the blank 2.

It should be noticed that the projection 27 or 28 intercepts the outer edges of the sides 3 or 4 of the blank 2 with a first lowering movement to the operating height Q1 or Q2, for intermediate covering of the outer surfaces of the pair of sides 1 b, 1 d or 1 c, 1 e of the box.

It should be noticed that each mobile element 20 or 21 , in this intercepting configuration of the projection 27 or 28, is in the first operating position in contact with the corresponding contact plate 18 or 19.

In turn, each contact plate 18 or 19 is in the second operating position with a centre-to-centre distance greater than the size of the box 1 to allow its free descending movement along the path P.

The box 1 with blank 2, descending to the corresponding operating height Q1 or Q2, allows the arced projection 27 or 28, to intercept the pair of sides 3 or 4 of the blank 2 and to lift them so that they are vertical (Figures 3 and 4 or 12 to 14).

In light of this, the plate 8 and the bracket 12 perform a further lowering of the box 1 and blank 2 to an intermediate operating height Q4 or Q5 located below the first operating unit 15 or the second operating unit 16. In this configuration each of the two sides 3 or 4 of the blank 2 has a lower flap 3a or 4a substantially abutting the outer surface of the wall 1 b, 1 d or 1 c, 1 e, whilst the upper flap 3b or 4b is aligned with the lower flap 3a or 4a and projects beyond the wall 1 b, 1 d or 1 c, 1 e of the box 1 .

In this position, each mobile element 20 or 21 moves from the first operating position to the second operating position along the line DR (Figures 5 and 6 or 15 and 16), in such a way as to fold towards the inside of the box 1 the upper flap 3b or 4b until said upper flap 3b or 4b is in a substantially horizontal configuration (by means of the presser element 32 or 33) and to define a free inner channel or gap S for folding between the presser element 32 or 33 and the contact plate 18 or 19. In light of this, the plate 8 and the bracket 12 perform controlled lifting of the box 1 and the blank 2 towards the operating height Q1 or Q2.

The upward movement of the box 1 causes the corresponding wall 3 or 4 to enter the gap S defined by the contact plate 18 or 19 and the presser element 32 or 33.

This movement allows a corresponding stabilisation of the lower flap 3a or 4a on the outer surface of the walls 1 b, 1 d or 1 c, 1 e of the box 1 and folding of the upper flap 3b or 4b towards the corresponding inner surface of the wall 1 b, 1 d or 1 c, 1 e of the box 1 (Figure 7 or 17).

Before and/or during the upward movement of the box 1 , each contact plate 18 or 19 moves from the second operating position towards the first operating position (again along the line DR) for defining the alignment and stabilisation of the lower flap 3a, 4a (Figures 6 and 16).

In a first embodiment, the plate 18 or 19 moves along the horizontal line DR reaching a third, intermediate position between the first and second operating positions.

In an alternative embodiment, the plate 18 or 19 moves along the horizontal line DR reaching the first operating position of alignment with the size of the box 1.

Having reached the operating height Q1 or Q2, the plate 8 and the bracket 12 are stopped, whilst the arm 25 or 26 of the mobile element 20 or 21 returns to the first operating position (opposite direction along the line DR) to terminate covering of the wall 1 b, 1 d or 1 c, 1 e, that is to say, (operating in conjunction with the fixed element 18 or 19) making the two flaps 3a or 4a and 3b or 4b, with glue on them, adhere on the corresponding surfaces of the wall 1 b, 1 d or 1 c, 1 e of the box 1 (Figure 8) thanks to the presser element 32 or 33.

In this position, the movement of the arm 25 or 26 may be aided by the movement of the plate 18 or 19 towards the first operating position of alignment with the size of the box 1 to complete adhesion of both of the flaps 3a, 4a and 3b, 4b on the corresponding surfaces of the walls of the box 1 .

As already indicated, this structure and these operating steps are also identical for the second operating unit 16 which is at the (second) height Q2, lower than the perimetric covering channel of the machine 100 and which therefore are not repeated, but are illustrated in Figures 12 to 18. Preferably, each blade 17 is mobile according to a predetermined angled trajectory T17, between a non-operating position, located outside the perimetric channel (Figure 9), and an operating position for folding located inside the perimetric channel (Figures 10 and 1 1 ), and vice versa.

Each blade 17 is connected to an actuator 29 able to control the corresponding blade 17, synchronised with the similar blade 17 positioned on the opposite side, between the two positions, respectively non- operating and operating (and vice versa).

Each blade 17 comprises a reduced thickness contact head (or brush) 30 connected to a rigid shaft 31 connected to the corresponding actuator 29. In light of this, when the arm 25 of the mobile element 20 of the first operating unit 15 performs a stroke towards the second operating position to free the walls 1 b, 1 d covered by the contact between the arm 25 and the contact plate 18, the plate 8 can perform a further descent of the box 1 below the (first) operating height Q1 and away from the first operating unit 15.

It should be noticed that the segments 5 and 6 to be folded, in this configuration, extend from the lower flap 3a of the side 3 of the blank 2 already folded and are aligned with the covered wall 1 b, 1 d of the box 1 . During the descent of the plate 8 and the bracket 12 with the box 1 towards the (second) operating height Q2 of the second operating unit 16, each blade 17 is activated and moves towards the segments 5, 6 with a line T17 angled towards the second operating unit 16.

Each blade 17 reaches its operating position of complete folding of the corresponding segment 5 and 6 towards the outer surface of the wall 1 c and 1 e still to be covered at a height almost near to the (second) operating height Q2 of the second operating unit 16 (see Figures 8 to 1 1 ).

It should be noticed that the partial overlap between folding of the segments 5 and 6 and the initial erection of the second pair of sides 4 of the blank 2 (in particular of the lower flap 4a) allows the segments 5 and 6 to be kept correctly in the folded position without unwanted "ears" forming on the segments 5 and 6.

As already indicated, the subsequent step of folding the second pair of (end) sides 4 of the blank 2 on the respective walls 1 c and 1 e of the box 1 is identical to what is described above for the first operating unit 15 (see again Figures 12 to 18).

Then, when the covering step by the second operating unit is complete, the plate 8 and the bracket 12 return the covered box 1 to the above- mentioned feed/unloading height Q0 to release it in a horizontal direction U opposite to the direction of feed A.

During this return upstroke step, the corresponding contact plates 15 or 16 are in the second operating position for box 1 transit and the mobile element 20 or 21 has the "L"-shaped arm 25 or 26 in the first operating position in contact with the corresponding contact plate 18 or 19.

This invention also provides a method for covering paper or cardboard boxes 1 using pre-glued paper blanks 2 having a plurality of sides 3, 4 which are joined to a base 2b, comprising the following steps:

- moving the box 1 coupled to the blank 2 along a vertical path P;

- folding the sides 3, 4 of the blank 2 to arrange them in a vertical position with respective lower flaps 3a, 4a in contact with corresponding side walls 1 b, 1 c, 1 d, 1 e of the box 1 ;

- folding upper flaps 3b, 4b of the sides 3, 4 of the blank 2 towards the inside of the box 1 , to move them from an upright position to a horizontal position;

- further folding of the upper flaps 3b, 4b of the sides 3, 4 of the blank 2 until they are in contact with inner faces of the corresponding side walls

1 b, 1 c, 1 d, 1 e of the box 1 ; - pressing the side walls 1 b, 1 c, 1 d, 1 e of the box 1 , by moving towards one another the upper flaps 3b, 4b and the lower flaps 3a, 4a of the sides 3, 4 of the blank 2, coupled respectively to the inner face and to the outer face of the walls 1 b, 1 c, 1 d, 1 e.

According to the invention, the pressing step comprises a movement of presser elements 20, 21 , positioned inside the box 1 and opposite corresponding side walls 1 b, 1 c, 1 d, 1 e of the box 1 , relative to contact plates 15, 16 positioned outside the box 1 in contact with corresponding side walls 1 b, 1 c, 1 d, 1 e of the box, for preventing the side walls from moving outwards, in which said movement of the presser elements 20, 21 occurs by translation along a horizontal line DR parallel with the base 1 a of the box 1 .

Preferably, before the pressing step:

- the box 1 is positioned at a height lower than at least one of the presser elements 20, 21 ;

- the presser element 20, 21 is positioned in a forward position relative to the corresponding contact plate 18, 19;

Preferably, the box 1 is moved, relative to the presser element 20, 21 , vertically until a corresponding side wall 1 b, 1 c, 1 d, 1 e of the box 1 is interposed between the contact plate 18, 19 and the presser element 20, 21 opposite it, respectively on the outside and on the inside of the box 1 . In light of this, the relative vertical movement between the presser element 20, 21 and the corresponding side wall 1 b, 1 c, 1 d, 1 e of the box 1 causes the further folding of the upper flap 3b, 4b of the side 3, 4 of the blank 2 coupled to the side wall 1 b, 1 c, 1 d, 1 e of the box 1 , until it is in contact with the inner face of the side wall 1 b, 1 c, 1 d, 1 e of the box 1 .

Preferably, the pressing step is carried out in at least two separate sub- steps, at corresponding pressing stations 15, 16 positioned at different heights Q1 , Q2, in which side walls 1 b, 1 c, 1 d, 1 e of the box 1 adjacent to each other are pressed in different sub-steps.

More precisely, each of the steps of folding the sides 3, 4 of the blank 2, of folding the upper flaps 3b, 4b of the sides 3, 4 of the blank 2 and of further folding of the upper flaps 3b, 4b of the sides 3, 4 of the blank 2 is carried out in at least two corresponding separate sub-steps, with the box 1 positioned at different heights Q1 , Q2, therefore:

- a first sub-step of folding a pair of non-consecutive sides 3, 4 of the blank 2, a first sub-step of folding the upper flaps 3b, 4b of the sides 3, 4 of the blank 2 and a first sub-step of further folding of said upper flaps 3b, 4b take place one after another and are followed by at least a corresponding sequence of second sub-steps, relating to another pair of non-consecutive sides 3, 4 of the blank 2.

Preferably, before the step of folding a side 3, 4 of the blank 2 to place it in a vertical position, the corresponding contact plate 18, 19 is placed in a position far from the vertical path P of the box 1 and the corresponding presser element 20, 21 is placed in a folding position in which it is positioned outside the vertical path P of the box 1 so that, during the folding step, it interacts with the corresponding side 3, 4 of the blank 2 during lowering of the box 1 relative to the presser element 20, 21 .

Preferably, before the step of folding one of the upper flaps 3b, 4b of the sides 3, 4 of the blank 2 towards the inside of the box 1 , the box 1 is positioned at a height Q4, Q5 lower than that of a corresponding presser element 20, 21 , with an upper edge of a corresponding side wall 1 b, 1 c, 1 d, 1 e of the box 1 near to a lower edge of the presser element 20, 21 , so that the folding occurs by moving the presser element 20, 21 horizontally towards the inside of the box 1 , in such a way that it interacts with the upper flap 3b, 4b, angling it towards the inside of the box 1.

Claims

1 . A machine for covering paper or cardboard boxes (1 ) using pre- glued paper blanks (2) having a plurality of sides (3, 4) which are joined to a base (2b), comprising:

- a vertically mobile plate (8) designed to support the base (2b) of the blank (2) with the box (1 ) coupled to it;

- means for folding the sides (3, 4) of the blank (2) to arrange them in a vertical position with respective lower flaps (3a, 4a) in contact with corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 );

- means for folding upper flaps (3b, 4b) of the sides (3, 4) of the blank (1 ) towards the inside of the box (1 ), moving them from an upright position to a horizontal position;

- means for folding the upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) into contact with the inner faces of the corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 );

- presser means, for each side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ), for pressing towards one another the upper flaps (3b, 4b) and the lower flaps (3a, 4a) of the sides (3, 4) of the blank (2) which are coupled respectively to the inner and outer faces of the wall (1 b, 1 c, 1 d, 1 e),

characterised in that the presser means (15, 16) comprise:

- contact plates (18, 19) positioned outside the box (1 ) for preventing an outward movement of the corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ) positioned in contact with them;

- presser elements (20, 21 ) mobile relative to the corresponding contact plates (18, 19) for translating along a horizontal line (DR) parallel with the base (1 a) of the box, and insertable in the box (1 ) for moving inside the box (1 ) towards the corresponding contact plates (18, 19) and parallel with them, for pressing the side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ) interposed between the contact plates (18, 19) and the corresponding presser elements (20, 21 ).

2. The machine according to claim 1 , wherein each contact plate (18, 19) is positioned at the same height (Q1 , Q2) as and opposite the corresponding presser element (20, 21 ).

3. The machine according to claim 2, wherein the contact plates (18, 19) are mobile along said horizontal line (DR) between a position far from a vertical path (P) of the box (1 ) and a position near to it, wherein the contact plates (18, 19) are in contact with the corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ) which is positioned at the height (Q1 , Q2) of the contact plates (18, 19).

4. The machine according to any one of the preceding claims, wherein the presser elements (20, 21 ) are connected (or hooked to the corresponding contact plates (18, 19).

5. The machine according to any one of the preceding claims, comprising a bracket (12) designed to be positioned resting on the base (1 a) of the box and operating in conjunction with the plate (8) to hold the base (1 a) of the box (1 ) interposed between them, wherein the plate (8) and/or the bracket (12) is motor-driven and connected to the control unit (1 1 ), for moving the box (1 ) along a vertical path (P), between positions at predetermined heights.

6. The machine according to claim 5, wherein the control unit (1 1 ) is programmed to move the box (1 ) along a vertical path (P) and is connected to one or more actuators (23, 24) for moving the presser elements (20, 21 ) relative to the corresponding contact plates (18, 19), for controlling, in a synchronised fashion:

- a movement of at least one of the presser elements (20, 21 ) away from the corresponding contact plate (18, 19), for defining between them a gap (S) for inserting a corresponding side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ), and

- a lifting of the box (1 ), from a height lower than that (Q1 , Q5) of said contact plate (18, 19), for bringing it to the height (Q1 , Q2) of the contact plate (18, 19), with the corresponding wall (1 b, 1 c, 1 d, 1 e) inserted in said gap (S).

7. The machine according to claim 5 or 6, wherein the control unit (1 1 ) is programmed to move the box (1 ) along a vertical path (P) and is connected to one or more actuators (23, 24) for moving the presser elements (20, 21 ) relative to the corresponding contact plates (18, 19), for controlling, in a synchronised fashion:

- a box (1 ) stop at a height lower than that of at least one of the presser elements (20, 21 ), with an upper edge of a corresponding side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ) near to a lower edge of the presser element (20, 21 );

- a movement of said at least one presser element (20, 21 ) away from the corresponding contact plate (18, 19) towards the inside of the box (1 ), for folding towards the inside of the box (1 ) the upper flap (3b, 4b) of the side (3, 4) of the blank (2) coupled to said side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ), moving it from the upright position to the horizontal position.

8. The machine according to any one of the preceding claims, wherein the plate (8) is vertically mobile relative to the presser elements (20, 21 ) for causing a relative translation between the box (1 ) and the presser elements (20, 21 ) positioned inside the box (1 ) near to corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ), for folding the upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) into contact with the inner faces of the corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ).

9. The machine according to any one of the preceding claims, comprising, for each presser element (20, 21 ), a projection (27, 28) connected to the presser element (20, 21 ) and extending upwards and horizontally away from a vertical path (P) of the plate (8), therefore the projection (27, 28) is shaped in such a way as to interact with the sides (3, 4) of the blank (2) coplanar with the base (2b) of the blank (2), for folding them into a vertical position with the respective lower flaps (3a, 4a) in contact with the corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ).

10. The machine according to any one of the preceding claims, comprising two pressing stations (15, 16) positioned at different heights (Q1 , Q2), wherein each pressing station (15, 16) comprises at least one of said contact plates (18, 19) and at least one corresponding presser element (20, 21 ).

1 1 . The machine according to claim 10, wherein each pressing station (15, 16) comprises two said contact plates (18, 19), positioned parallel with and opposite one another and mobile towards and away from each other between corresponding far and near positions, in which they are in contact with corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ) which are parallel with one another.

12. The machine according to any one of the preceding claims, comprising, for each contact plate (18, 19), a corresponding "L"-shaped arm (25, 26) horizontally mobile relative to the respective contact plate (18, 19) and comprising a horizontal stretch, positioned at the top of the contact plate (18, 19), and a vertical stretch (32, 33) opposite the contact plate (18, 19) for forming said presser element (20, 21 ).

13. A method for covering paper or cardboard boxes (1 ) using pre- glued paper blanks (2) having a plurality of sides (3, 4) joined to a base (2b), comprising the following steps:

- moving the box (1 ) coupled to the blank (2) along a vertical path (P);

- folding the sides (3, 4) of the blank (2) to arrange them in a vertical position with respective lower flaps (3a, 4a) in contact with corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 );

- folding upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) towards the inside of the box (1 ), for moving them from an upright position to a horizontal position;

- further folding of the upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) until they are in contact with inner faces of the corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 );

- pressing of the side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ), by moving towards one another the upper flaps (3b, 4b) and the lower flaps (3a, 4a) of the sides (3, 4) of the blank (2), coupled respectively to the inner face and to the outer face of the walls (1 b, 1 c, 1 d, 1 e),

characterised in that the pressing step comprises a movement of presser elements (20, 21 ), positioned inside the box (1 ) and opposite corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ), relative to contact plates (15, 16) positioned outside the box (1 ) in contact with corresponding side walls (1 b, 1 c, 1 d, 1 e) of the box for preventing their outward movement, wherein said movement of the presser elements (20, 21 ) occurs by translation along a horizontal line (DR) parallel with the base (1 a) of the box (1 ).

14. The method according to claim 13, wherein, before the pressing step,

- the box (1 ) is positioned at a height lower than at least one of the presser elements (20, 21 );

- said at least one presser element (20, 21 ) is positioned in a forward position relative to the corresponding contact plate (18, 19);

- the box (1 ) is moved, relative to said at least one presser element (20, 21 ), vertically until a corresponding side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ) is interposed between the contact plate (18, 19) and the presser element (20, 21 ) opposite it, respectively on the outside and on the inside of the box (1 ).

15. The method according to claim 14, wherein said relative vertical movement between said at least one presser element (20, 21 ) and the corresponding side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ) causes said further folding of the upper flap (3b, 4b) of the side (3, 4) of the blank (2) coupled to said side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ), until it is in contact with the inner face of said side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ).

16. The method according to any one of claims 13 to 15, wherein the pressing is carried out in at least two separate sub-steps, at pressing stations (15, 16) positioned at different heights (Q1 , Q2), in which side walls (1 b, 1 c, 1 d, 1 e) of the box (1 ) which are adjacent to one another are pressed in different sub-steps.

17. The method according to claim 16, wherein each of said steps of folding the sides (3, 4) of the blank (2), of folding upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) and of further folding of the upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) takes place in at least two corresponding separate sub-steps, with the box (1 ) positioned at different heights (Q1 , Q2), therefore a first sub-step of folding a pair of non- consecutive sides (3, 4) of the blank (2), a first sub-step of folding upper flaps (3b, 4b) of said sides (3, 4) of the blank (2) and a first sub-step of further folding of said upper flaps (3b, 4b) take place one after another and are followed by at least a corresponding sequence of second corresponding sub-steps, relating to another pair of non-consecutive sides (3, 4) of the blank (2).

18. The method according to any one of claims 13 to 17, wherein, before the step of folding a side (3, 4) of the blank (2) to place it in a vertical position, the corresponding contact plate (18, 19) is placed in a position far from the vertical path (P) of the box (1 ) and the corresponding presser element (20, 21 ) is placed in a folding position in which it is positioned outside the vertical path (P) of the box (1 ) so that, during the folding step, it interacts with the corresponding side (3, 4) of the blank (2) during lowering of the box (1 ) relative to the presser element (20, 21 ).

19. The method according to any one of claims 13 to 18, wherein, before the step of folding one of the upper flaps (3b, 4b) of the sides (3, 4) of the blank (2) towards the inside of the box (1 ), the box (1 ) is positioned at a height (Q4, Q5) lower than that of a corresponding presser element

(20, 21 ), with an upper edge of a corresponding side wall (1 b, 1 c, 1 d, 1 e) of the box (1 ) near to a lower edge of the presser element (20, 21 ), therefore said folding occurs by moving said presser element (20, 21 ) horizontally towards the inside of the box (1 ), in such a way that it interacts with the upper flap (3b, 4b), angling it towards the inside of the box (1 ).