WO1996004129A1 - Device and method for forming a box from a blank - Google Patents

Abstract

Method and device (1) for forming a box (2) from a blank (3) of sheet material including means (8, 9, 10, 12, 13) for storing several blanks in a stack, means (14, 15, 21) for gripping and shifting the blanks one by one to a blank-prefolding mandrel (16). The prefolding mandrel (16) disposed at the outlet of the blank storage means (10) is associated with the prefolding means (33). The invention also comprises means (23, 25) for conveying the prefolded blank from the prefolding mandrel to a final folding mandrel (24), and blank coating means (42), the final folding mandrel (24) comprising a lower side. The device includes means (38) for compressing the intermediate blank flap onto the lower side (65) of the final folding mandrel.

Description

DEVICE AND METHOD FOR PRODUCING A BOX FROM A BLANK

The present invention relates to a device for producing a box from a blank of sheet material comprising a series of rectangular flaps connected to each other by first fold lines parallel to each other, comprising an intermediate flap , and a first set of lateral flaps arranged on one side of said series of flaps, connected thereto by second fold lines perpendicular to the first fold lines and intended to form at least partially the bottom of the box, the device being of the type comprising means for storing blanks in stacks, a pre-folding mandrel disposed on the outlet of the storage means, gluing means and means for transferring the blank thus pre-folded to a definitive folding mandrel. The invention also relates to a method for producing a cash register in particular using a device of the type defined above.

It finds a particularly important, although not exclusive, application in the field of packaging objects or groups of objects which are introduced from above into the preformed packaging, the packaging being closed later, for example by an attached cover. A device of the type defined above is already known (DE-4209191 - A1).

This device has drawbacks. In particular, the transfer of the pre-wound blank around the mandrel involves risks of rearing and deformation of the blank. In addition, the gluing precision depends on the tightening on the mandrel, and the folding of the flaps used does not make it possible to obtain a body that is perfectly squared repeatedly.

The present invention aims to provide a method and a device of the type defined above, better meeting those previously known to the requirements of practice, in particular in that it makes it possible to produce a perfectly squared box, at high speed, and this easy to implement.

To this end, the invention essentially proposes a device for producing a box from a blank of sheet material comprising a series of rectangular flaps connected to each other by first fold lines parallel to each other, comprising an intermediate flap, and a first set of lateral flaps arranged on one side of said series of flaps, connected thereto by second fold lines and intended to form at least partially the bottom of the box, said device comprising : means for storing several blanks in a stack,

means for gripping and moving one by one of said blanks towards a pre-folding mandrel of said blanks,

said pre-folding mandrel, disposed on the outlet of the storage means of said blanks and associated with pre-folding means, means for transferring the blank thus pre-folded from the pre-folding mandrel to a definitive folding mandrel,

- means for gluing the blank, - and said definitive folding mandrel comprising a lower face, characterized in that the device comprises means for pressing the intermediate flap of the blank onto the underside of the definitive folding mandrel. In advantageous embodiments, use is made of one and / or the other of the following arrangements:

- The plating means consist of profiles, blades or the like arranged to progressively compress elastically the intermediate flap of the blank against the underside of the final folding mandrel during transfer;

the plating means comprise means for supporting the intermediate flap at a distance from the folding mandrel and means arranged to progressively bring closer and to press said intermediate flap on the underside of the final folding mandrel; the support means consist of a movable plate;

- The pre-folding mandrel is of section having a shape different from that of the definitive folding mandrel; the pre-folding mandrel has a rectangular section and the final folding mandrel has an octagonal section;

the means for gripping and moving said blanks towards the pre-folding mandrel comprise side arms for gripping by blank suction cup, located outside and pivoting on either side of the pre-folding mandrel, and suction means for taking up said blank by means of said pre-folding mandrel, said suction-taking means being associated with the means for moving the pre-folded blank, from the pre-folding mandrel to the folding mandrel;

- The device comprises, at the level of the final folding mandrel, means for intermediate folding of the bottom flaps before pressurizing on the one hand flaps intended to form the side walls, and on the other hand flaps intended to form said bottom ; - The device includes a synchronous system for plating the bottom on the final folding mandrel;

- The pre-folding mandrel is arranged directly above the outlet of the blank storage means; - The folding mandrel is of different section between a first pre-folding position and a second position for forming the box.

The invention also provides a method for producing a box from a blank of sheet material comprising a series of rectangular flaps connected to each other by first fold lines parallel to each other, comprising a flap intermediate and a first set of lateral flaps arranged on one side of said series of flaps, connected thereto by second fold lines perpendicular to the first fold lines and intended to form at least partially the bottom of the body, process in which:

- we store several blanks in a stack,

- said blanks are taken and moved one by one towards a pre-folding mandrel of said displaced blank,

- said blank is pre-folded,

the blank thus pre-folded is transferred from the pre-folding mandrel to a definitive folding mandrel,

- the blank is glued during the transfer, - and the blank is wrapped around said definitive folding mandrel comprising a lower face, characterized in that, during the winding of said blank around the mandrel, the intermediate flap of the blank is pressed onto the underside of the final folding mandrel.

Advantageously, the method is characterized in that, in order to press said blank, the intermediate flap of the blank is progressively compressed elastically against the underside of the final folding mandrel during transfer.

In another advantageous embodiment, the method is characterized in that, in order to press the intermediate flap at the level of the folding mandrel, said intermediate flap is progressively brought closer to the underside of the definitive folding mandrel against which it comes to bear entirely at the end of plating, by means of a movable plate.

The invention will be better understood on reading an embodiment of the invention given below by way of nonlimiting example.

The description refers to the accompanying drawings in which: Figure 1 is a schematic side elevation view of an embodiment of the device according to the invention.

Figure 2 is a schematic partial side view of the device of Figure 1 after movement and formation of the box around the final folding mandrel.

Figure 3 is a sectional view along III-III of Figure 1 showing more particularly the pre-folding mandrel.

Figures 4 to 10 schematically show in cross section, at the level of the final folding mandrel, the formation of the box produced according to the embodiment of the invention more particularly described here.

Figures 1 and 2 schematically show a device 1 for the production of a box 2 from a blank 3 (in phantom in Figure 1) of sheet material comprising a series of rectangular flaps 4 connected to each other by first fold lines 5 parallel to each other, comprising an intermediate flap, and a first set of lateral flaps 6 arranged on one side of the series of flaps, connected to the latter by second fold lines 7 and intended to form at least partially the bottom of the body.

The device 1 comprises a magazine 8 for supplying horizontal blanks or flat blanks comprising a forklift 9 of the stack 10 of blanks, kept at constant level during unstacking. Means 17 for precise positioning and setting of the blanks in xy are provided. At the end of each stack, it is replaced by a next stack 12, waiting on rollers 13, and suitable for being pushed on the forklift which is lowered for this purpose. With the device more particularly described here, the unstacking is done directly above the stack 10 thanks to six or eight gripping suction cups, namely on the one hand two suction cups 14, respectively secured to two lateral arms 15, arranged on either side of the pre-folding mandrel 16 and arranged to take a first position 17, for gripping by suction of the cutout from above 18, a second position 19, for leveling the cutout horizontally substantially under said mandrel, and a third position 20 for release of the arms upwards, for example using a series 21 of pneumatic or electric articulated jacks, and on the other hand one or two series of two articulated suction cups 22, for resumption of cutting, disposed through the mandrel 16, axially with respect thereto and integral with the carriage 23 for transferring the pre-folded blank, over at least part of the path, towards the mandrel 24 for definite folding f (see figure 2). The carriage 23, integral with the suction cups 22 is for example actuated by an articulated assembly 25 comprising an arm 26 actuated by a rod 27, the arm being mounted so as to pivot about a transverse horizontal axis 28 fixed at one of its ends. The arm 26 comprises at its other end an articulated rod 29, one end of which is pivotally mounted on the said other end of the arm 26 and the other end 30 is on the one hand guided horizontally by a rail. horizontal guide disposed parallel to the mandrels, and on the other hand movable in rotation relative to a part 31 secured to the carriage 23, said part being provided with a pawl pawl 32 arranged to come into contact with the rear part of the blank 3.

Means 33 for pre-folding or at least partially winding the blank on the mandrel 16 are provided, comprising arms 34, suitable for compressing vertically on the mandrel 16 the two longitudinal flaps located on either side of the lower intermediate flap (see also figure 3). The arms are for example articulated around an axis 35 and movable parallel to the longitudinal axis of the mandrel between a retracted position, set back relative to the blank, and an active position for compressing the flaps against the mandrel.

In the embodiment more particularly described here, the pre-folding mandrel is of rectangular section, having a recessed longitudinal central part, for passage of the transfer carriage 23 equipped in the lower part of the central suction cups 22 between the pre-folding position 36 (see figure 2) and the folding position 37. The mandrel 16 is for example constituted by four horizontal, metallic bars 16 ', rectangular rectangular, forming the four corners of the mandrel.

The device 1 further comprises plating means 38 comprising a movable plate 39 for plating the intermediate flap 40 of the pre-folded blank on the underside 41 hollowed out of the mandrel 24 for final folding, gluing means 42 comprising for example nozzles injection for application of hot glue known under the English name of "hot melt", and / or cold glue injection nozzles known to those skilled in the art, disposed on the path between the pre-folding mandrel 16 and the folding mandrel 24 located in the horizontal extension of each other, the pre-folding mandrel therefore transforming into a folding mandrel of smaller cross section in the embodiment more particularly described here. The blank 3 pre-folded in a U on the pre-folding mandrel 16 and which is transported via the carriage 23 does not undergo, during transport between the mandrel 16 and the mandrel 24, significant friction resistance due to the smaller cross section of the second mandrel, a gap between the transfer device and the pre-folding mandrel being formed with a value greater than the thickness of the blank material.

The blank is transferred by a vacuum system (suction cup) and a mechanical pusher, to be permanently pressed onto the surface of the mandrel.

Guide rails are also provided, the assembly being arranged so that it produces only rolling friction during the transfer process.

The device 1 also comprises means 43 for folding the flaps 6 intended to form the bottom of the package.

These means 43 include push cylinders 44, a closing plate 45 for example actuated by a cam device 46 between a position in horizontal withdrawal, and a position for pressing the bottom on the mandrel, which has a face end 47 suitable for serving as a support to support the forces during pressurization for bonding the bottom.

In the embodiment more particularly described here, the device 46 also makes it possible to actuate the carriage 23, via the rod 27, at the same time as the plate 45, which allows perfect mechanical repeatability and therefore very high precision, the movements being mechanically linked as will be described below.

To do this, the end 48 of the rod 27, opposite the arm 26 is fixed in rotation to a vertex 49 of a triangle 50, movable in rotation around a transverse horizontal axis 51 located at another vertex and integral with the device chassis 1.

The third apex 52 is in turn integral in rotation with a rod 53 fixed at its other end to a movable arm 54, integral with a cam 55 via a roller 56 between a low position where the carriage 23 is at the folding station , and a high position where the carriage is at the pre-folding station.

The plate 45 has, in turn, its position controlled by the cam 57 via a roller 59 fixed on the middle part of an arm 60, one end is fixed to the frame 61 of the device 1 and the other is secured to a rod 62 for controlling the plate 45, a pneumatic cylinder 58 acting on an articulated rod itself secured to a rod whose other end is secured to the plate. The plate 45 is therefore movable between a vertical position and a horizontal position, according to a determined mechanical time diagram, as a function of the position of the carriage 23. Means for ejecting the box formed, for example via the carriage 23 capable of assuming an extreme position located beyond the mandrel 24, and means 63 for recovering said box, for example comprising a conveyor belt, finally complete the device .

We will now describe with reference to Figures 4 to 10 showing in cross section a portion of the folding station 37, the final formation of the box before its ejection.

In the following, the same reference numbers have been used to represent the same elements.

In the embodiment more particularly described here, the folding mandrel 24 is of octagonal section, having cut corners 64, and a horizontal lower face 65, the plating means 38 comprising a plate 39 of shape complementary to the lower part of the mandrel.

As described above, the lower face 65 can for example be hollowed out or be presented in any other equivalent way for the skilled person. For example, the folding mandrel can be, similarly to the pre-folding mandrel, formed by four profiled bars, parallel and horizontal, metallic, forming the four cut corners of the mandrel.

The preformed U-shaped blank 3 on the pre-folding mandrel is guided by lateral rails to the folding station, a station at which its intermediate flap 66 is located at a distance from the bottom of the plate 39 (see FIG. 4).

The plate 39 of the intermediate flap 66 of the blank is brought closer (see FIG. 5), for example via a jack hydraulic 67 by pressing said flap against the mandrel.

The cut corners of the body are thus pressed onto the cut corners of the mandrel in a single vertical movement from bottom to top.

Also and for example, in an equivalent manner, two lateral jacks of complementary shape to the cut corners can be provided for pressing the intermediate flap on the underside of the mandrel by simply compressing the cut corners framing the intermediate flap on the cut corners opposite screw of the folding mandrel, by a vertical, oblique or lateral movement of said cylinders.

Given the complementary shapes, the side flaps 68 are thus brought closer to the mandrel with which they are therefore in contact, the pusher fingers 44, also coming to complete this shaping.

A tab 69 (FIG. 6), for example actuated by a jack 70, then presses the upper flap

71 on the mandrel, the tongue 72 also being applied by a piece 73 to the upper cut corner 74.

Then a piece 75 having a face of complementary shape to the cut corner (Figure 7) presses the end flap 76 connected to the flap 71 on the tongue 72 to complete the winding.

Together or following the operations which have just been described, the operations for closing the bottom of the body are also carried out (FIGS. 8 to 10).

Two push cylinders 77, lateral, close the vertical lateral flaps 78; then the horizontal lateral flaps 79 are folded down, in two stages, by an actuator 80 (for the upper flap 81), then using the plate 45, after erasing the actuator 80. Once the bottom 81 is finished, the plate 45 is erased, the plate 39 descends, controlled by the cam 57 and an internal ejection device of the mandrel (not shown) performs a longitudinal movement and ejects the body towards the means 63 for taking up the body, before loading.

As is obvious and as it follows from the above, the invention is not limited to the embodiment more particularly described. On the contrary, it embraces all variants, and in particular those where the folding and pre-folding means are actuated differently, for example by pneumatic, electric or hydraulic means slaved to each other by a programmable automaton, rather than by a system of cams.

Also the plating means on the folding mandrel can be different, the main thing being that the plating function is carried out, making it possible to obtain a box in a repetitive and precise manner.

We will now describe the operation of the device 1 with particular reference to FIG. 1.

The blank 3 located just below the pre-folding mandrel 16 is gripped by the suction cups 14 connected in a manner known per se to a vacuum device, the device 21 then being in the low position.

Then the arms 15 are mounted and the blank 3 is placed below the interior face of the rectangular mandrel 16. The suction cups 22 then grip the blank from the inside of the mandrel 16, the suction cups 14 being vented and the arms 15 are raised completely in the vertical position. The arms 34 then pivot and grip the side flaps of the blank 3 which are U-shaped and pressed against the mandrel.

The carriage 23 integral with the suction cups 22 is then automatically moved by the cam system, the pawl 32 pushing the blank to the folding position on the mandrel 24.

In passing, the gluing means 42 deposit the glue necessary for fixing the flaps together, and for fixing the flaps together to form the bottom in known manner, up to the folding position on the mandrel 24.

The plate 39 is then approached and pressed on the mandrel before or simultaneously with the folding of the upper flap by the tab 69, the tongue 72 then being compressed on the upper flap which has been previously glued on its contact part with the tongue.

Before applying the tongue or simultaneously, the small lateral flaps 75 of the bottom are folded under pressure on the bottom 47 of the mandrel and then the tongue 72 is applied; the upper flap 77 is folded, the lower flap and upper flap assembly then being pressed against the bottom of the mandrel by the plate 45. During forming, the carriage 23 is returned to its initial position, actuated by the cam system dimensioned in consequence, to take a blank and repeat the operation. Once the formation of the box is finished, it is ejected when the carriage returns with a new blank, all the jacks and other devices having participated in the forming returning to their initial position, and so on.

Claims

1. Device (1) for producing a box (2) from a blank (3) of sheet material comprising a series of rectangular flaps (4) connected to each other by first fold lines ( 5) parallel to each other, comprising an intermediate flap (66), and a first set of lateral flaps (6) arranged on one side of said series of flaps, connected to the latter by second fold lines (7 ) perpendicular to the first fold lines and intended to form at least partially the bottom of the box, said device comprising: - means (8, 9, 10, 12, 13) for storing several blanks in a stack, means (14 , 15, 21) for gripping and moving one by one of said blanks to a mandrel (16) for pre-folding said blanks, - said mandrel (16) for pre-folding, arranged on the outlet of the means (10) for storing said blanks and associated to pre-folding means (33), means (23, 25) for transferring the blank thus pre-folded from the pre-folding mandrel to a definitive folding mandrel (24), - means (42) for gluing the blank, and said mandrel (24) for final folding comprising a lower face, characterized in that the device comprises means (38) for plating the intermediate flap of the blank on the lower face ( 65) of the final folding mandrel. 2. Device according to claim 1, characterized in that the folding mandrel has an octagonal section. 3. Device according to any one of claims 1 and 2, characterized in that the plating means (38) comprise means (39) for supporting the distance from the intermediate flap at the folding mandrel and means (67) arranged to gradually bring closer and to press said intermediate flap (66) on the underside (65) of the final folding mandrel. 4. Device according to claim 3, characterized in that the support means (39) consist of a movable plate. 5. Device according to any one of the preceding claims, characterized in that said plating means comprise at least one vertical action cylinder from the bottom up capable of exerting the plating function of said intermediate flap on the folding mandrel. 6. Device according to claim 5 dependent on claim 2, characterized in that said plating means comprise two cylinders with oblique or lateral vertical action, compressing the cut corners framing said intermediate flap, on the cut corners opposite said folding mandrel. 7. Device according to any one of claims 1 and 2, characterized in that the plating means (38) consist of profiles, blades or the like arranged to gradually compress the shutter in an elastic manner. intermediate of the blank against the underside of the final folding mandrel during transfer. 8. Device according to any one of the preceding claims, characterized in that the pre-folding mandrel (16) has a cross section having a shape different from that of the definitive folding mandrel (24). 9. Device according to claim 8, characterized in that the pre-folding mandrel (16) has a rectangular section and the definitive folding mandrel (24) has an octagonal section. 10. Device according to any one of the preceding claims, characterized in that the means (14, 15, 21) for gripping and moving said blanks towards the pre-folding mandrel comprise arms (15) lateral for gripping by suction cup (14) of the blank, located outside and pivoting on either side of the pre-folding mandrel (16), and means (22) for sucking up said blank by means of said pre-folding mandrel (16), said suction cup recovery means being associated with means (23) for moving the pre-folded blank, from the pre-folding mandrel to the folding mandrel. 11. Device according to any one of the preceding claims, characterized in that it comprises, at the level of the mandrel (24) for final folding, means (44) for intermediate folding of the bottom flaps before pressurization on the one hand of the flaps intended to form the side walls, and on the other hand flaps intended to form said bottom. 12. Device according to any one of the preceding claims, characterized in that it comprises a system (45, 46) for plating the bottom on the final folding mandrel with double (55, 57). 13. Device according to any one of the preceding claims, characterized in that the pre-folding mandrel (24) is disposed directly above the outlet of the blank storage means. 14. Device according to any one of the preceding claims, characterized in that the folding mandrel (24) is extensible between a first retracted position and a second position for forming the box. 15. Method for producing a box (2) from a blank (3) of sheet material comprising a series of rectangular flaps (4) connected to each other by first fold lines (5) parallel to each other, comprising an intermediate flap (66), and a first set of lateral flaps (6) arranged on one side of said series of flaps, connected to the latter by second fold lines (7) perpendicular to the first fold lines and intended to form at least partially the bottom of the box, process in which: - we store several blanks in a stack, - said blanks are taken and moved one by one towards a mandrel (16) for pre-folding said blanks, - said blanks are pre-folded, - the blank thus pre-folded is transferred from the pre-folding mandrel to a mandrel (24) for final folding, - the said blank is glued during the transfer, - and the said blank is wrapped around the said final folding mandrel comprising a lower face, characterized in that, to wind the said blank around the mandrel, the intermediate flap is pressed (16) of the blank on the underside of the final folding mandrel. 16. Method according to claim 15, characterized in that, in order to press said blank, the intermediate flap of the blank is progressively compressed elastically against the underside of the final folding mandrel during transfer. 17. The method of claim 15, characterized in that, to press the intermediate flap at the folding mandrel, said intermediate flap is progressively brought closer to the lower face (41) of the final folding mandrel against which it comes to fully support at the end of the tackle.