ES1312731U - EMPTY BOX STACKING MACHINE WITH STABILIZATION DEVICE (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Stacking machine (20) for nestable empty boxes (B) made of semi-rigid sheet material, with a bottom panel (PF) and side walls (PL) inclined convergently towards the bottom panel (PF), comprising: - a box (B) conveyor (21), configured to move the boxes (B) from a box receiving end, capable of being located below an outlet for boxes (B) formed in a mould (8) of a box forming machine (10) (B), towards a box delivery end (B); - a lifting cavity (23) adjacent to the delivery end, configured to accommodate the boxes (B) forming a vertical stack (P) of boxes (B), previously lifted by a lifting device (24) including a lifting actuator vertically movable between a lower lifting position, where the lifting device (24) is configured to receive the boxes from the conveyor (21), and an upper lifting position, where the lifting device (24) is configured to transfer the boxes to a holding device (25) configured to hold the boxes (B) forming a stack (P) in the lifting cavity (23); - a stabilization device (30) supported at the receiving end, comprising: a vertical linear drive (33) comprising first and second parts (33a, 33b) provided with relative vertical movement with respect to each other; a suction cup (34) vertically movable by the vertical linear drive (33); and a detection device (35) associated with the vertical linear drive (33); and wherein the suction cup (34) is configured to be positioned inferiorly adjacent to the bottom panel (PF) of the box (B), to retain by suction the boxes (B) by said bottom panel (PF), in a downward path of the box (B), from an upper box position associated with the mold (8), towards a lower box position determined by the detection device (35); and wherein the detection device (35) and the suction cup (34) are jointly configured to release the bottom panel (PF), at least in the lower position, to position the released box (B) in the lower position on a transport plane (22, 21a) of the stacking machine (20). (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Stacking machine for empty and nestable boxes with stabilizing device

TECHNICAL SECTOR

The technical field of the present invention is the positioning of boxes made of semi-rigid sheet material, for example, cardboard, at the exit of a forming station of a box forming machine, for example, of the type that includes a male or mandrel that moves with a back and forth or oscillating motion in and out of a folding die or mold.

OBJECT OF THE INVENTION

The present invention relates to a stacking machine for boxes made of semi-rigid sheet material comprising a stabilization device arranged at the receiving end of a conveyor.

Semi-rigid sheet means a sheet-shaped material that maintains its shape unless subjected to external forces and that has a certain rigidity when folded/bent.

Said semi-rigid sheet material includes the cases of a corrugated cardboard sheet (board), a compact cardboard sheet (also called cardboard cardboard, laminated cardboard, or stretched cardboard), a sheet formed by a cardboard sheet joined to one or more internal and/or external plastic sheets, a die-cut sheet of compact plastic, a die-cut sheet of corrugated or extruded plastic, a sheet that combines sheets of paper and plastic, as well as any material worked in a manner analogous to paper or cellulose fiber-based material.

BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEM TO BE SOLVED

Document ES1235813U discloses a stabilizing element 50 located at the receiving end of a conveyor 2 of a box stacking machine 1, intended to receive formed and empty boxes that descend by gravity through the lower part of a mold of a box forming machine 100. The stabilizing element 50 cooperates with side plates 51, one on each side of the conveyor. The stacking machine 1 also comprises a regulating device 60 that regulates the position or one end of the stabilizing element 50 on the conveyor 2 in a position further away or closer to the receiving end of the conveyor 2 to allow different box sizes to be stacked in use without modifying the relative position between the stacking machine 1 and said forming machine 100.

This solution in document ES1235813U works correctly by stabilizing straight-walled boxes individually at speeds of up to about 3,200 boxes per hour. In straight boxes, each side wall is 90 degrees relative to the bottom panel, i.e. parallelepiped-shaped boxes.

This solution in document ES1235813U works with boxes of considerable weight, in the order of 500 to 1000 grams each, due to the typical thickness between 4 and 5 mm and typically double-walled structure (with two corrugated sheets and two smooth sheets) of the semi-rigid sheet with which they are made, all of which results in a weight that helps the stability of the box.

Inconveniently, said solution of document ES1235813U is not viable for the stabilization of nestable boxes, of the type that have walls with a convergent inclination towards their bottom panel, with a mouth of width and length measurements greater than those of the bottom panel, intended to be inserted / nested, at least partially, one inside the other with their side walls in mutual contact.

This convergent inclination of the nestable boxes, with an inverted truncated pyramid shape, with chamfered or unchamfered edges, together with the evacuation/expulsion of the boxes one by one from the forming machine, means that these nestable boxes, of reduced weight, and empty, are not stabilized in any way with the stabilization element 50 in cooperation with the side plates 51 of the end of the conveyor of document ES1235813U.

Thus, document ES1235813U is not intended to solve the technical problem of the unitary stabilization of nestable boxes, with inclined walls, and with smaller sheet thicknesses (lower box weight), which descend one by one leaving a box forming machine.

On the other hand, in order to stabilize the aforementioned mutually nestable boxes with inclined side walls, formed in a box forming machine of the male or insertable and removable head type by actuating a mold with a cavity delimited by a plurality of forming elements, the mold may have associated guides, presses or brushes that nest and fit the boxes in the lower outlet mouth, expelling discrete or continuous batches of boxes from the machine. In this sense, documents US4522618A, ES2914929A1, ES1254508U, ES1306841U, ES1310346U may be cited. The following web link may also be cited https://www.voutube.com/watch?v=vSauGSqqsHw&feature=emb title .

Said document US4522618A discloses a station with a male 40 with an inverted truncated pyramidal body which is introduced vertically into a mould to form boxes. A horizontal conveyor belt arranged at the outlet of the mould tilts the container so that its lower end is directed in the direction of movement of the belt (Fig. 5). The belt then drives the container in a lying orientation towards other containers which have been similarly directed and which have been stopped by a stop bar so that the container will nest with the last of the previous containers producing a complete series of nested containers which can be taken out as a group.

Said document ES2914929A1 discloses an accessory that is a box nesting device 3 with two formed box guides 3a, which are slide-shaped (Fig. 3), one associated with each mold 50. Each box nesting device 3 inserts a box B, previously bent by the aforementioned side faces 8 of the male and benders 52, 53, into another, to make the flat side walls WL of a box B contact the flat side walls WL of other boxes B that form a stack of nested boxes. The formed box guides 3a formed do not form an integral part of the mould 50 but are associated with it, since they are located to receive the formed boxes B with inclined side walls coming from the mould 50. The box guides 3a of Fig. 1 are not necessarily supported on the chassis 1 of the machine 100. Document ES2914929A1 describes an alternative embodiment (not shown in the figures), where the two formed box guides 3a can be supported on the chassis 1 forming an integral part of the mould 50 and located in the area of the aforementioned outlet mouth of the mould 50.

In document ES1254508U, at the exit of the mould for forming boxes with inclined walls, there are two pressers 4 that can be moved horizontally by cylinders 5, which count a number of formed containers, and open when they reach a number of nested boxes as a batch, lowering by gravity packages or batches of nested boxes nested together.

Between the moments 01:12 and 01:34 [mm:ss] of the aforementioned video from the link https://www.voutube.com/watch?v=vSquGSgqsHw&feature=emb title with 2940 views as of May 24, 2024, it corresponds to a video of the FT04.01 machine from the Italian manufacturer of corrugated and compact cardboard packaging forming machines Teco Italy ( http://tecoitaly.com/es/ ), in both forming stations of the machine, the containers are formed in batches by nesting one inside the other, before being removed by gravity, by two pairs of pressing cylinders, mutually facing each other in pairs, horizontally movable between a position in which they are in contact with the formed containers and a position in which they separate from each other to extract the batch or stack of mutually nested containers. At this moment it is observed that when the batches of boxes fall onto a belt, some of them are overturned, with the bottom panel of the lower box of the batch not being in contact with the conveyor belt.

However, the solutions proposed above offer solutions that cannot be adapted to improve the stability of formed and empty nesting boxes that descend individually from the outlet of a box forming machine, since the problem is greatly complicated by the fact that it is not a batch or group of boxes, which have a considerable combined weight that ensures the stability of the boxes, avoiding an unwanted overturning of the boxes, but rather the boxes are stably extracted one by one.

The stability of boxes with inclined walls that descend one by one from the forming machine is a particularly difficult challenge, since the boxes, in addition to their conical geometry (inverted truncated pyramid), have a very reduced thickness, for example between 0.3 and 2 millimetres, whether they are made of corrugated cardboard or compact cardboard, laminated cardboard, cardboard and/or mixed cardboard (made of a sheet of cardboard/paper and a plastic sheet joined together), etc., and therefore, they have a lower weight that tends to tip/knock the boxes down when they are coming out of the box forming machine, all of which becomes more complicated at higher production speeds.

On the other hand, the Italian company that manufactures corrugated and compact cardboard packaging forming machines, Teco Italy, announces, in the first half of November 2024, at the link:

https://www.linkedin.com/posts/teco-italy tecoperformance-automazione-efficienza-activity-7257747527968428034-HJsn?utm source=social share video v2&utm medium=android app&utm campaign=cop and link

a straight-sidewall cardboard box forming machine from flat sheets, of the male type movable in and out of a forming mould, having fixed to its chassis, below the mould, a box stabilisation and reorientation device comprising a vertical linear drive, a rotary drive mounted on a movable part of the vertical linear drive, and a suction cup movable vertically by the vertical drive between an upper position for suctionally retaining the boxes (B) by said bottom panel (PF), and mounted on the rotary drive for changing the orientation of the suction cup and the boxes 90 degrees during the downward travel of the box (B), from an upper position of the box associated with the mould (8), to a lower position associated with a conveyor, thereby reducing the working space.

The technical problem of the present invention is to improve productivity in the unitary evacuation of formed and empty boxes that are mutually nestable/nestable at the exit of a box forming machine with a desired position/orientation, reducing production downtime and mitigating and/or eliminating overturning of the boxes, all of which results in an improvement in the productivity of nestable/nestable boxes evacuated individually.

EXPLANATION OF THE INVENTION

To solve the drawbacks set out in the previous section, the present invention differentially presents a stacking machine for boxes made of semi-rigid sheet material, empty of product, and nestable within each other, each box having a bottom panel and side walls inclined convergently towards the bottom panel.

Thus, the box stacking machine is configured to work with the semi-rigid sheet material boxes mentioned above.

In the present invention the terms "nesting boxes" and "nestable boxes" are synonymous and mean that the boxes have an upper opening through which they are capable of being inserted into each other, at least partially, being capable of contacting flat side walls of a tray inclined convergently towards its bottom with the inclined flat walls of another similar box, to be capable of forming a batch or stack of trays.

Throughout the present invention, tray, box and container are synonyms.

“Semi-rigid sheet material” means a sheet-like material which maintains its shape unless subjected to external forces and which has a certain rigidity when folded/bent. Such semi-rigid sheet material includes a corrugated (corrugated) cardboard sheet, a compact cardboard sheet (also called cardboard board, laminated cardboard, laminated cardboard or stretched cardboard), a sheet consisting of a cardboard sheet joined to one or more internal and/or external plastic sheets, a sheet combining cardboard/paper and plastic sheets, and any material worked in a manner analogous to paper or cellulose fibre-based material.

The stacking machine comprises a box conveyor, configured to move boxes from a box receiving end to a box delivery end. The receiving end is capable of being positioned below an outlet for boxes formed in a mold of a box forming machine.

Likewise, the stacking machine comprises a lifting cavity, a lifting device, a supporting device, and a stabilizing device arranged at the receiving end.

The lifting cavity is adjacent to the delivery end. The lifting cavity is configured to accommodate the boxes forming a vertical stack of boxes previously lifted by the lifting device.

The lifting device includes a lifting actuator vertically movable, according to a vertical direction Z, between a lower lifting position, where the lifting device is configured to receive the boxes from the conveyor, and an upper lifting position, where the lifting device is configured to transfer the boxes to a holding device.

The support device, associated with the upper position of the lifting device, is configured to support the boxes in an elevated position forming a stack in the lifting cavity.

Preferably, the lifting device can lift one or more boxes at a time, the lifting cavity can accommodate one or more stacks of boxes at a time, and the supporting device can support one or more stacks of boxes at a time, so that the stacking machine can stack one or more stacks of boxes at a time.

The stacking machine further comprises a stabilizing device supported at the receiving end of the conveyor.

The stabilization device comprises a vertical linear drive comprising a first and second part provided with relative vertical movement relative to each other, according to the vertical direction Z, perpendicular to the ground plane where the stacking machine is located.

The stabilization device also includes a suction cup that can be moved vertically by the vertical linear drive.

Furthermore, the stabilization device comprises a detection device associated with the vertical linear drive.

Likewise, in the stacking machine, the suction cup is configured to be positioned inferiorly adjacent to the bottom panel of the box, to retain the boxes by suction by said bottom panel, in a downward path of the box, from an upper box position associated with the mold, towards a lower box position determined by the detection device.

Also, in the stacking machine, the sensing device and the suction cup are jointly configured to release the bottom panel, at least in the lower position, to position the released box in the lower position on a transport plane of the stacking machine.

That is to say, to solve the problem of productivity in the evacuation of empty boxes with inclined side walls in the shape of an inverted truncated pyramid that descend individually from a box forming machine, the present invention differentially proposes a stacking machine object, in which a stabilization device is supported at the receiving end of a conveyor, which has a vertical linear drive, a suction cup movable by the drive and a detection device associated with the suction cup.

On the contrary, to solve the stability of nestable box packs, the state of the art focuses on grouping the boxes in discrete or continuous batches, by providing stabilization devices fixed to the mold of the forming machine in combination with the release of box packs by gravity, or by providing accessory devices to the forming machine as slide guides, forming a continuous batch of boxes.

Some advantages of the stacking machine of the present invention are described below in relation to its technical characteristics.

Firstly, the stabilisation device is advantageously and intentionally included in the stacking machine, supported at the receiving end of the conveyor thereof, which facilitates the positioning (installation) of the stabilisation solution in a wide range of models of box forming machines, since the solution for stabilising the boxes does not depend on the specific measurements and parts of the box forming machines, as repeatedly occurs in the state of the art, resulting in a reduction in production downtime, due to the easy installation of the stacking machine object with the integrated stabilisation device of the present invention, leading to an increase in productivity in the unitary evacuation of the inverted truncated pyramidal boxes.

Second, advantageously, the positioning of the box during its downward path is very precise and reliable, preventing any positional deviation and/or lateral overturning, since the suction cup allows the suction retention of the box, eliminating positional deviations: the position/orientation of each box does not fall under the arbitrariness introduced by gravity during descent. Furthermore, the suction cup and the detection device are configured to release the box in the lower position, and optionally in a lower downward path positioned below the lower position, advantageously providing a smooth and precise positioning of each box on the transport plane, and advantageously avoiding an undesirable rebound effect of the empty inverted truncated pyramidal box, usually of reduced thickness, when it comes into contact with the transport plane comprised in the stabilization device or in the conveyor.

Thirdly, advantageously, the effective unitary stabilization of the nestable/nestable boxes at the exit of the forming machine, thanks to the stabilization device comprised by the present invention in the stacking machine, at the box receiving end of the conveyor thereof, allows the possibility of carrying out additional tasks/operations on each of the boxes susceptible of being moved unitarily along the conveyor thanks to the transition zone provided by the conveyor between its receiving and delivery ends, after the unitary stabilization of boxes on the transport plane and before the boxes are raised and supported forming a stack of mutually nested boxes housed in the lifting cavity.

In the detailed exposition of embodiments described below, some optional features of the present invention are explained and the advantages and technical effects provided by each of them are detailed.

BRIEF DESCRIPTION OF THE DRAWINGS

To complement the description being made of the object of the invention and to help in a better understanding of the characteristics that distinguish it, this descriptive report is accompanied, as an integral part thereof, by a set of plans, in which the following have been represented for illustrative and non-limiting purposes:

Figs. 1 and 2 are side views of a first embodiment of the stacking machine of the present invention, with the suction cup in the upper and lower box positions, respectively, and further showing that the box receiving end of the conveyor is located below a box outlet formed in a mold of a box forming machine shown in dashed line;

Fig. 3 is a side view cut away according to a longitudinal section of the stacking machine of Figs. 1, 2, 15 and 16, where the lifting device, the lifting cavity, and the supporting device are shown, and where a stack of boxes lifted, supported and housed in the lifting cavity has been represented;

Fig. 4 is a top perspective view of the stacking machine of Figs. 1 and 2;

Figs. 5 and 6 are cut-away side views of the stacking machine of Figs. 1 and 2, respectively, showing the stabilizing device at the receiving end of the conveyor, with the suction cup in the upper and lower box positions, respectively;

Fig. 7 is a top perspective view of the stabilization device removed from the receiving end of the conveyor;

Fig. 8 is an exploded top perspective view of the stabilizing device, and of some elements of the receiving end of the conveyor, of Fig. 7;

Fig. 9 is a top perspective view of the stabilization device of Figs. 2, 4, 6 and 7 with the suction cup in the lower position;

Fig. 10 is a top perspective view of the stabilization device of Figs. 1 and 5 with the suction cup in the upper box position;

Figs. 11 and 12 show the stabilization device of Figs. 9 and 10, respectively, in a bottom perspective view;

Figs. 13 and 14 show the stabilization device of Figs. 11 and 12, respectively, according to another bottom perspective view; and

Figs. 15 and 16 are side views of a second embodiment of the stacking machine of the present invention, with the suction cup in the upper and lower box positions, respectively, and further showing that the box receiving end of the conveyor is located below a box outlet formed in a mold of a box forming machine shown in dashed line.

DETAILED EXPOSURE OF IMPLEMENTATION MODES / EXAMPLES

Throughout Figs. 1 to 4 and 15 and 16, reference 20 generically designates the stacking machine (20) for empty boxes (B) made of semi-rigid sheet material that can be nested within each other.

That is, the box (B) stacking machine (20) is configured to work with said boxes (B) that are empty of product inside them, and that are nestable thanks to side walls (PL) inclined convergently towards the bottom panel (PF) of the same.

The boxes (B) shown throughout Figs. 1 to 16 have an upper opening, through which boxes (B) can be inserted into other boxes (B), at least partially, being able to contact flat side walls (PL) of a box inclined convergently towards its bottom panel (PF) with the inclined flat side walls (PL) of another similar box (B), to be able to form a batch or stack (P) of boxes (B), as shown in Fig. 3.

As shown in Figs. 1 to 8 for the first embodiment, and Figs. 15, 16 and 3 for the second embodiment, the stacking machine (20) comprises a box (B) conveyor (21), configured to move the boxes (B) according to a linear transport direction (T) from a box receiving end to a delivery end.

As shown in Figs. 1 and 2 for the first embodiment and Figs. 15 and 16 for the second embodiment, the receiving end of the conveyor (21) is capable of being located below an outlet of boxes (B) formed in a mould (8) of a box forming machine (10) (B).

Continuing in Figs. 1, 2, 15 and 16, the mold (8) comprises a plurality of forming elements and a cavity (9) delimited peripherally by said plurality of forming elements.

Figs. 1, 2, 15 and 16 show that a male (7) or head with an inverted truncated pyramidal body corresponding to the shape of the box (B) is vertically movable in a vertical direction (Z) by a male drive (not shown), between the inserted position of Figs. 1 and 15 and the extracted position of Figs. 2 and 16, to be introduced and extracted from the cavity (9) of the mold (8).

Thus, the mould (8) and the core (7) cooperate to form boxes (B) with side walls (PL) inclined convergently towards their bottom panel (F), starting from a plate initially situated below the core (7) in the extracted position and above the mould (8).

In Figs. 1 to 3, 15 and 16 the stacking machine (20) further comprises a stacking station including a lifting cavity (23), a lifting device (24), a supporting device (25), and a stabilizing device (30) arranged at the receiving end of the conveyor (21).

In Figs. 1 to 3, 15 and 16, the lifting cavity (23), in the form of a vertical tunnel, is adjacent to the delivery end. The lifting cavity (23) is configured to accommodate the boxes (B) forming a vertical stack (P) of boxes (B) previously lifted by the lifting device (24).

Optionally, the lifting cavity (23) with an essentially parallelepiped shape is delimited on two of its sides by at least two lateral structures (23a), one on each side.

The lifting cavity (23) is optionally delimited on another side by at least one pusher plate (23b) movable by a horizontal cylinder to move the stacks (P) of boxes (B) to an exit site of the stacking machine (20).

The lifting device (24), shown in detail in Fig. 3, includes a lifting actuator, for example, a cylinder, vertically movable, according to a vertical direction (Z), between a lower lifting position (not shown), where the lifting device (24) is configured to receive the boxes from the conveyor (21), and an upper lifting position shown in Fig. 3, where the lifting device (24) is configured to transfer the boxes to a supporting device (25).

In Fig. 3 it is shown that the lifting device comprises a lifting surface (24a) attached to a movable part of the lifting actuator. For example, the lifting surface (24a) may be defined by a plate and/or a suction cup as shown in the figures, by two horizontal bars (not shown), among other options.

In Figs. 1 to 3, 15 and 16, the support device (25) associated with the upper lifting position of the lifting device (24), is configured to support the boxes (B) in an elevated position forming a stack (P) in the lifting cavity (23).

Optionally, the support device (25) includes spring-retractable stops as shown in the figures (or retraction cylinders not shown) arranged on two sides of the lifting cavity (23) that protrude into the lifting cavity (23), to support the boxes resting on said stops, and are retracted out of the lifting cavity (23) to allow the vertical passage of the boxes (B) upwards in the lifting cavity (23).

Preferably, the lifting device (24) can lift one or more boxes (B) at a time, the lifting cavity (23) can accommodate one or more stacks of boxes (B) at a time, and the supporting device (25) can support one or more stacks (P) of boxes (B) at a time, so that the stacking machine (20) can stack one or more stacks (P) of boxes (B) simultaneously.

Figs. 1, 2, 4, 15 and 16 show that, for both embodiments, the stacking machine (20) further comprises a stabilizing device (30) supported at the receiving end of the conveyor (21).

In Figs. 1, 2 and 4 to 16, the stabilization device (30) comprises a vertical linear drive (33). The vertical linear drive (33) comprises first and second parts (33a, 33b) provided with relative vertical movement relative to each other, according to the vertical direction (Z).

The vertical linear drive (33) may be a fluid-dynamic cylinder, for example, pneumatic, provided with a body as a first part (33a) and a rod as a second part (33b) and as shown in the figures. Alternatively, the vertical linear drive may be a mechanism that includes a vertical rack moved by a pinion associated with a rotating electric motor (not shown), or a belt attached to a rotating electric motor (not shown), among other options.

Preferably, the second part (33b) of the figures is an anti-rotation rod.

In another embodiment (not shown in the figures) the second part (33b) is guided by vertical linear drive rod guides (33) guided in the body, to position/orient the box (B) accurately on the transport plane (22, 21a).

Optionally, a turning device (not shown) may be arranged on the second part, which changes the orientation of the box to a stable turned position during the downward travel.

Figs. 1, 5, 7 to 10, 12, 14 and 15 show that the stabilization device (30) comprises a suction cup (34) movable vertically by the vertical linear drive (33).

In an option not shown in the figures, the stabilization device (30) may comprise a plurality of suction cups (34).

The suction cup (34) is connected in operation to a vacuum generating source, for example, a Venturi device, or alternatively to a vacuum pump, among other options.

Furthermore, the stabilization device (30) comprises a detection device (35) associated with the vertical linear drive (33).

Optionally, the sensing device (35) may include or correspond to an inductive detector, as shown in Figs. 1, 2, 5, 6, 8 and 13 to 16.

In the stacking machine (20), the suction cup (34) is configured to be positioned inferiorly adjacent to the bottom panel (PF) of the box (B), to retain by suction the boxes (B) by said bottom panel (PF), in a downward path of the box (B), from the upper box position associated with the mold (8) shown in Figs. 1, 5, 10, 12, 14 and 15, towards the lower box position of Figs. 2, 4, 6, 7, 9, 11, 13, 16 determined by the detection device (35).

In the stacking machine (20), the sensing device (35) and the suction cup (34) are jointly configured to release the bottom panel (PF), at least in the lower position, to position the released box (B) in the lower position on a transport plane (22, 21a) of the stacking machine (20), with the bottom panel (PF) in contact with the transport plane (21, 21a), as shown in Figs. 2, 6, 9 and 16.

That is, the suction cup (34) and the detection device (35) are configured to release the box (B) in the lower position and/or in a lower descending path positioned below the lower position, providing a smooth and precise positioning of each box (B) on the transport plane (22, 21a), and advantageously avoiding an undesired rebound effect of the empty inverted truncated pyramidal box (B) of usually reduced thickness, when contacting the conveyor plane (22, 21a).

Thus, in the upper box position and on a downward path towards the lower position, the suction cup (34) holds the boxes (B) by suction on the bottom panel (PF). Then, upon detection of the lower position of the suction cup (34) by the detection device (35), which can be connected to a control unit (not shown), for example a programmable logic controller (PLC), this sends a signal to a vacuum generating source connected to the suction cup (34) to cut off the suction of the vacuum cup (34) in said lower position and/or during a vertical downward path located below the lower position.

In a preferred option, Figs. 1, 2, 4 and 8 to 16 show that the stabilization device (30) further comprises a first vertical positioning device (36, 37), comprising a first vertical guide (36) and a first fixing and releasing device (37), configured to modify the upper position of the suction cup (34) in the vertical direction (Z).

In this preferred option, advantageously, the first vertical positioning device (36, 37) allows to stabilize, effectively retaining by suction, a wide variety of box heights (B), of different measurements between the bottom panel (PF) and the upper mouth delimited by the upper parts of the side walls (PL), all of this resulting in a mitigation of downtime in the stabilization of the boxes (B), and an improvement in the productivity of said operation.

Throughout the present invention, the term "vertical guide" should be understood in a broad sense, and includes the cases of a slot, elongated hole or vertically arranged hole, aligned with the vertical direction (Z), as well as the case of tongue and groove projections (with first and second parts sliding relative to each other) arranged vertically, such as the case of a vertically arranged spindle, and a combination of these, among other options.

Throughout the present invention, the expression “fixing and releasing device” must be understood in a broad sense, and includes the cases of screws, for example: a screw, a bolt, or a handle or lever that includes a threaded rod as a screw, and includes the case of the threaded edges of a vertically arranged spindle, and a combination of these, among other options.

Thus, Figs. 1, 2, 4 and 8 to 16 show that the first vertical guide (36) is a slot, elongated hole or slot arranged vertically parallel to the vertical direction (Z), aligned with the vertical direction (Z), while the first fixing and release device (37) is a handle that includes a threaded rod in the form of a screw, the first fixing and release device (37) modifying the upper position of the suction cup (34) in the vertical direction (Z).

Preferably, Figs. 1, 2 and 4 to 16 show that the stabilization device (30) further comprises a second vertical positioning device (38, 39), comprising a second vertical guide (38) and a second fixing and releasing device (39), configured to modify the position of the detection device (35) according to the vertical direction (Z).

In this preferred option, advantageously, the second vertical positioning device (36, 37) allows to mitigate the undesired rebound effect described above, releasing the bottom panel (PF) from the suction of the suction cup (34) in a desired position, to work a wide variety of box heights (B), of different measurements between the bottom panel (PF) and the upper mouth delimited by the upper parts of the side walls (PL), all of this resulting in a mitigation of downtime in the stabilization of the boxes (B), and an improvement in the productivity of said operation.

Thus, Figs. 1, 2, 4 and 8 to 16 show that the second vertical guide (38) is a slot, elongated hole or slot arranged vertically parallel to the vertical direction (Z), aligned with the vertical direction (Z), while the second fixing and releasing device (39) is a handle that includes a threaded rod in the form of a screw, the second fixing and releasing device (39) modifying the position of the detector device (35) according to the vertical direction (Z).

Continuing in Figs. 4 to 10 and 14, the stacking machine (20) comprises a chassis (26), and a support (31) mounted on the chassis (26). The stabilization device (30) is mounted on the support (31) in a removable manner relative to the chassis (26) by an auxiliary fixing and releasing device (31a, 31b) configured to fix and release the main support (31) from the chassis (26) at the receiving end of the conveyor (21).

Advantageously, this construction of the stabilization device (30), mounted on the support (31) which is in turn mounted on the chassis (26), facilitates the integration of the stabilization device (30) in both new and existing stacking machines, in addition to shortening installation times, all of which results in a reduction in production stops, and in an improvement in productivity in the stabilization of units of inverted truncated conical boxes (B).

Optionally, the support (31), as shown in Figs. 7 and 8, is formed by a set of pieces joined together by screws and/or welding. Thus, the support (31) in Figs.

7 and 8 comprises two support sides extending in the conveying direction (T) of Figs. 1 to 6, 15 and 16, a support crossbar screwed together between the two sides and extending in the transverse direction (Y), and a prominently vertical complementary support bolted to each support side. The complementary support of the support (31) supports the vertical linear drive (34), the suction cup (34), and the detection device (35) as shown in Fig. 8. At the distal ends of the support sides are screwed plugs where an auxiliary fixing and releasing device (31a, 31b) is located for removably attaching to the receiving end of the chassis (26) of the conveyor (21). Said auxiliary fixing and releasing device (31a, 31b) will be described in detail later.

In an alternative embodiment of the support (31) not shown in the figures, the support (31) may be a single piece.

In the embodiment of Figs. 15 and 16, the stabilization device (30) is mounted at least partially directly on the chassis (26).

Throughout this specification, the term “mounted” and the term “supported” should be understood as synonyms and refer to one element being mounted/supported, either directly or indirectly, on another element.

The auxiliary fixing and releasing device (31a, 31b) includes a plurality of screw elements (31b), shown in detail in Figs. 7 to 10 and 14.

The plurality of screw elements (31b) connect in Figs. 1 to 6, 15 and 16 the chassis part (26) of the conveyor receiving end (21) with the support (31) where the stabilization device (30) is mounted.

The plurality of screw elements (31b) pass through holes (31a), made in the chassis (26) and support (31), respectively, and facing each other correspondingly. The plurality of screw elements (31b) is removable from the first holes (31a) as shown in Figs. 7 and 8 to release the support (31) from the chassis (26).

Optionally, Figs. 5 to 14 show that the stabilizing device (30) further comprises a secondary support (32) mounted on the support (31). In addition, the vertical linear drive (33) is mounted on the secondary support (32), and the suction cup (34) is arranged on the second part (33b). Also, in the box stacking machine (20), the first vertical linear positioning device (36, 37) is configured to modify the position of the vertical linear drive (33) and secondary support (32) according to the vertical direction (Z) relative to the support (31).

In Figs. 1 to 16, for both embodiments, the transport plane (22, 21a) is defined by coplanar upper surfaces of two worm flexible transmission elements, parallel to each other and separated from each other according to a transverse direction (Y), between which the suction cup (34) is arranged.

Throughout this specification, the expression "flexible transmission element" includes the cases of a chain, for example, a link chain, a toothed or smooth belt, a band or strip, among other options.

The coplanar upper surfaces refer to an upper section of the worm flexible transmission elements, which are capable of transporting the boxes (B) one after the other.

In the stacking machine (20) of the embodiment of Figs. 1 to 14, the two flexible worm transmission elements are auxiliary transport transmission elements (22, 22) included in the stabilizing device (30).

Additionally, Figs. 7 to 10 show that the stabilization device (30) further comprises two rotating shafts (40, 40) and four wheels (41). Two wheels (41) are fixed to each rotating shaft (40) and each auxiliary transport transmission element is coupled to two of said wheels (41), one on each rotating shaft (40).

In the example of Figs. 7 to 10, each auxiliary transport transmission element (22) is a belt, tape or band coupled to two wheels (40), as a pulley, one front and one rear.

In an embodiment not shown, the wheels (40) may be toothed by having grooves, the wheels (40) being toothed pulleys and the auxiliary transport transmission element (22) being a toothed belt whose teeth are capable of engaging in said grooves.

In another embodiment not shown, the wheels (40) may be toothed by having meshing teeth, the wheels (40) being pinions and the auxiliary transport transmission element (22) being a link chain.

Optionally, Figs. 7 to 10, 13 and 14 show that the stabilizing device (30) further comprises an auxiliary wheel (42) mounted on one of said rotating shafts (40), and a flexible linking worm transmission element (43) coupled to the auxiliary wheel (42) and to a transport wheel (28) of the conveyor (21), preferably movable by the rotating electric motor (27).

According to the second embodiment, shown in Figs. 15 and 16, in the stacking machine (20), the two worm flexible transmission elements are two transport transmission elements (21a, 21a) comprised in the conveyor (21), preferably movable by the rotary electric motor (27).

Continuing in the first embodiment of the stacking machine (20) of Figs. 1 to 13, the stabilizing device (30) further comprises two side guides (44), one side guide (44) being on each side of the transport plane (22, 21a), for guiding the boxes (B) to be transported on the transport plane (22, 21a).

Continuing with the second embodiment of the stacking machine (20) of Figs. 1 to 13, the stacking machine (20) further comprises a guide adjusting device (45, 46) configured to change the separation according to a transverse direction (Y) between the two side guides (44), and configured to change the position of the side guides (44) according to a vertical direction (Z) with respect to the transport surface (22, 21a), to guide said boxes (B) of different sizes and/or of different inclinations on the side walls (PL).

In the example of the figures, the guide regulating device (45, 46) comprises two secondary linear guides (45) articulatedly supported on the chassis (26) and/or support (31), each linear guide (45) supporting a respective lateral guide (44).

The guide regulating device (45, 46) further comprises two secondary fixing and releasing devices (46), one associated with each side guide (44), each secondary fixing and releasing device (46) being configured to fix and release the side guide (44) to change the transverse separation between side guides (44) and the height of the guides.

In the other embodiment of the stacking machine (20) of Fig. 15 and 16, it comprises two side guides (44) supported on the chassis (26), with one side guide (44) on each side of the transport plane defined by the two transport transmission elements (21a, 21a), for guiding the boxes (B) to be transported on the conveyor (21).

The operation of the box stacking machine (20) is summarized below, according to a possible preferred option, where the formed boxes (B) coming from an output of a box forming machine (10) (B) are received at the receiving end of the conveyor (21) in a reliable and safe manner by the stabilization device (30) arranged at the receiving end of the conveyor (21).

With the suction cup (34) in the upper position, holding the box (B) by suction at the bottom panel (PF), the second part (33b) of the vertical linear drive (33) moves the suction cup (34) with the bottom panel (PF) held in a downward path of the box (B) towards a lower position, determined by the detection device (35), oriented towards said second part (33b).

In the example of the figures, a plate or piece (33c) shown in Figs. 5, 9 and 15, fixedly or integrally attached to the second part (33b), is facing the detector device (35) in the lower position of Figs. 2, 6, 10 and 16, and the detector device (35) causes in this lower position the release of the bottom panel (PF), leaving the suction cup (34) to retain the bottom panel (PF). The box (B) may remain in the release position supported by the suction cup (34).

Optionally, the suction cup (34) travels along a lower descending section or path, additional to the descending section referred to above, with the box (B) supported and not held by suction until the box (B) is placed on the transport plane (22, 21a) of the stacking machine (20).

The transport plane (22, 21a) is either part of the stabilisation device (30) itself, as shown in Figs. 1 to 14, or part of the conveyor (21) of the stacking machine (20), as shown in Figs. 15 and 16.

In Figs. 1 to 4 and 15 and 16 the conveyor (21) comprises two mutually parallel conveyor bands, belts, straps or chains (21a, 21a) movable by an electric motor (27) of the conveyor (27).

The boxes (B) are then moved by the conveyor (21) from the receiving end to the delivery end.

Continuing in Figs. 1 to 4 and 15 and 16, the boxes (B) coming from the conveyor (21) are supported on a lifting surface (24a) of the lifting device (24), and are lifted by the actuator of the lifting device (24) from a lower lifting position to an upper lifting position.

In the upper lifting position, the lifting device (24) transfers the boxes to a supporting device (25) which supports the boxes (B) forming a stack (P) in the lifting cavity (23), as shown in Fig. 3.

As shown in Fig. 3, the lifting cavity (23) adjacent to the delivery end houses the boxes (B) forming a vertical stack (P) of boxes (B), previously raised by the lifting device (24).

Optionally, when the desired number of boxes (B) making up the stack (P) is reached, the pusher plate (23a) is moved by a horizontal cylinder towards the exit site of the stacking machine (20).

The scope of the present invention is given by the following claims.

Claims (12)

1.- Stacking machine (20) for empty boxes (B) made of semi-rigid sheet material that can be nested within each other, with a bottom panel (PF) and side walls (PL) inclined convergently towards the bottom panel (PF), comprising: a box (B) conveyor (21), configured to move the boxes (B) from a box receiving end, capable of being located below an outlet of boxes (B) formed in a mold (8) of a box forming machine (10) (B), towards a box delivery end (B); a lifting cavity (23) adjacent to the delivery end, configured to accommodate the boxes (B) forming a vertical stack (P) of boxes (B), previously elevated by a lifting device (24) including a vertically movable lifting actuator between a lower lifting position, wherein the lifting device (24) is configured to receive the boxes from the conveyor (21), and an upper lifting position, wherein the lifting device (24) is configured to transfer the boxes to a holding device (25) configured to hold the boxes (B) forming a stack (P) in the lifting cavity (23); a stabilizing device (30) supported at the receiving end, comprising: a vertical linear drive (33) comprising first and second parts (33a, 33b) provided with relative vertical movement relative to each other; a suction cup (34) movable vertically by the vertical linear drive (33); and a detector device (35) associated with the vertical linear drive (33); and wherein the suction cup (34) is configured to be positioned inferiorly adjacent to the bottom panel (PF) of the box (B), to retain by suction the boxes (B) by said bottom panel (PF), in a downward path of the box (B), from an upper box position associated with the mold (8), towards a lower box position determined by the detection device (35); and wherein the sensing device (35) and the suction cup (34) are jointly configured to release the bottom panel (PF), at least in the lower position, to position the released box (B) in the lower position on a transport plane (22, 21a) of the stacking machine (20). 2. - Stacking machine (20) for boxes (B) according to claim 1, wherein the stabilization device (30) further comprises a first vertical positioning device (36, 37), comprising a first vertical guide (36) and a first fixing and releasing device (37), configured to modify the upper position of the suction cup (34) in the vertical direction (Z). 3. - Stacking machine (20) for boxes (B) according to claim 2, wherein the stabilization device (30) further comprises a second vertical positioning device (38, 39), comprising a second vertical guide (38) and a second fixing and releasing device (39), configured to modify the position of the detection device (35) according to the vertical direction (Z). 4. - Stacking machine (20) for boxes (B) according to any one of claims 1, 2 or 3, comprising a chassis (26), and a support (31) mounted on the chassis (26), the stabilization device (30) being mounted on the support (31) in a removable manner with respect to the chassis (26) by an auxiliary fixing and releasing device (31a, 31b) configured to fix and release the main support (31) from the chassis (26) at the receiving end. 5. - Stacking machine (20) for boxes (B) according to claim 4, wherein the stabilization device (30) further comprises a secondary support (32) mounted on the support (31), where the vertical line drive (33) is mounted on the secondary support (32), where the suction cup (34) is arranged in the second part (33b); and wherein the first vertical linear positioning device (36, 37) is configured to modify the position of the vertical linear drive (33) and secondary support (32) according to the vertical direction (Z) with respect to the support (31). 6. - Stacking machine (20) for boxes (B) according to any one of the preceding claims, wherein the transport plane (22, 21a) is defined by coplanar upper surfaces of two endless flexible transmission elements, parallel to each other and separated from each other in a transverse direction (Y), between which the suction cup (34) is arranged. 7. - Stacking machine (20) for boxes (B) according to claim 6, wherein the two flexible endless transmission elements are auxiliary transport transmission elements (22, 22) included in the stabilizing device (30). 8. - Stacking machine (20) for boxes (B) according to claim 7, wherein the stabilization device (30) further comprises two rotating axes (40, 40) and four wheels (41), two wheels (41) being fixed to each rotating axis (40), and each auxiliary transport transmission element being coupled to two of said wheels (41), one on each rotating axis (40). 9. - Stacking machine (20) for boxes (B) according to claim 8, wherein the stabilization device (30) further comprises an auxiliary wheel (42) mounted on one of said rotating shafts (40), and a flexible linking endless transmission element (43) coupled to the auxiliary wheel (42) and to a transport wheel (28) of the conveyor (21). 10. - Stacking machine (20) for boxes (B) according to any one of claims 6 to 9, wherein the two endless flexible transmission elements are two transport transmission elements (21a, 21a) included in the conveyor (21). 11. - Stacking machine (20) for boxes (B) according to any one of the preceding claims, wherein the stabilization device (30) further comprises two lateral guides (44), being a lateral guide (44) on each side of the transport plane (22, 21a), to guide the boxes (B) to be transported on the transport plane (22, 21a). 12. - Stacking machine (20) for boxes (B) according to claim 11, further comprising a guide adjusting device (45, 46) configured to change the separation according to a transverse direction (Y) between the two side guides (44), and configured to change the position of the side guides (44) according to a vertical direction (Z) with respect to the transport surface (22, 21a), to guide said boxes (B) of different sizes and/or of different inclinations on the side walls (PL).