WO2024165778A1

WO2024165778A1 - Machine for forming cardboard boxes

Info

Publication number: WO2024165778A1
Application number: PCT/ES2024/070066
Authority: WO
Inventors: José BOIX JAEN
Original assignee: Boix Maquinaria Spain, S.L.U.
Priority date: 2023-02-08
Filing date: 2024-02-06
Publication date: 2024-08-15
Also published as: ES2978495A1

Abstract

The invention relates to a machine that comprises a conveying system for die-cut sheets that carries the sheets (3) from at least one loader (6) to a forming station (2) of the machine (1), such that each sheet (3) is retrieved from the loader (6) so as to be conveyed to horizontal longitudinal bars (12), and then each sheet (3) is pulled to the forming station (2) of the machine (1) by a conveyor device (5) that is able to hold the sheet (3) on its path in the same horizontal plane. The machine (1) further comprises one or more loaders (6) and one or more forming stations (2), and each loader (6) incorporates retaining devices, complementary to one another, for constantly retaining stacked sheets in the loader (6) in order to avoid machine (1) downtime.

Description

DESCRIPTION

CARDBOARD BOX FORMING MACHINE

Object of the invention

The present invention relates to a cardboard box forming machine comprising a die-cut sheet transfer system for transferring the sheets from at least one loader to a forming station of the machine. In this situation, each sheet is picked up from the loader by means of a suction cup device which is responsible for depositing the sheet on longitudinal bars and then the sheet is dragged to the forming station of the machine by means of a conveyor device, keeping the sheet in the same horizontal plane as it travels. The invention also relates to the machine itself, which comprises the transfer system, one or two loaders and one or two forming stations.

Technical problem to be solved and background of the invention

Nowadays, cardboard box forming machines are known, which generally comprise a forming station that integrates a mold and a core, as well as a transfer system for the die-cut sheets, from which the boxes are assembled, so that said transfer system is responsible for handling the sheets until they are brought to the forming station.

The die-cut sheets are initially stacked in a loader, so that a suction cup device is used to transfer the sheets individually to place them on horizontal guides and then to be transferred by a dragging device to the forming station where each box is assembled.

Among others, the cardboard box forming machines with publication numbers in Spain ES2644329, ES2081235, ES1280854 and ES112780 are known.

All these cited documents disclose good but complex and ineffective solutions if what is of interest is to achieve very high forming speeds.

The last two documents cited from this same title as the invention in question, are clear examples of machines of the type that concerns us with their respective die-cut sheet conveyor systems.

Description of the invention

In order to achieve the objectives and avoid the drawbacks in the previous sections, the invention proposes a system for transferring die-cut sheets in a cardboard box forming machine; the invention also relates to the machine itself.

The transfer of the sheets is carried out along at least one transport line from at least one loader in which the sheets are stacked to a forming station of the machine that includes at least one core and at least one mould; and where the transfer system collects the sheets individually from the loader to deposit them on longitudinal bars, and a conveyor device that drags the sheets individually to the forming station.

The conveyor device comprises a frame to which a first pair of driving sprockets integral with a transverse drive shaft and a second pair of driven sprockets are coupled, which receive transmission from the first pair of sprockets by means of two parallel longitudinal chains; where the longitudinal bars are located above the conveyor device. Said transverse drive shaft receives the rotary movement from a single motor-reducer.

In another embodiment of the transfer system, the first pair of pinions are integral with respective independent drive shafts separately connected to respective gear motors; where the transmission to the first pair of pinions is carried out separately and independently through the two gear motors.

The conveyor device further comprises at least one drive mechanism that is fixed to one of the two chains by means of a connecting body; where the drive mechanism comprises a vertical guide to which the connecting body is coupled and guided.

The vertical guide is attached to a slider that is coupled to a lower guide that runs parallel along the chain below it; where said guide The lower part is a fixed element attached to the frame of the conveyor device.

An adjustable support is attached to the vertical guide of the conveyor device, to which a pusher piece is attached, by means of which each sheet is moved when it is supported on the longitudinal bars to the forming station.

During the movement of the chains, the connecting body moves guided along the vertical guide driven in the lower guide, while the entire assembly of the drive mechanism is configured to move dragged by the chain, keeping the height of the adjustable support and its pusher piece constant.

The adjustable support of the drag mechanism has a horizontal bar configuration that can be fixed in different positions on the vertical guide, while the pusher piece is fixed to one end of the adjustable support.

The cardboard box forming machine comprises at least the die-cut sheet transport system, the loader and also the forming station.

The machine loader includes a first retaining device for holding the stack of sheets stacked by its rear face corresponding to the last sheet, opposite a front face of the stack that corresponds to a first sheet prepared to be collected by the suction cup device; where the stack of sheets is supported on a first longitudinal guide centered on which the first retaining device is coupled, which comprises a first linear actuator to which a first stop is connected that is configured to retain the stack of sheets by its rear face.

The loader also includes two second retaining devices for holding the stack of sheets stacked by two opposite sides of its rear face by means of second retractable stops that form part of the second retaining devices.

These second retaining devices are configured to be activated during sheet feeding from the magazine, at which time the first device is deactivated; where when the first retaining device is activated, the second retaining devices are deactivated and retracted. Each of the second retaining devices comprises a second linear actuator coupled to a support integral with a side plate integral with a frame of the loader; where a rod of the linear actuator is connected to a first end of an elongated profile guided in a recess of a body that is fixed to a fixed guide integral with the side plate.

The fixed guide includes a longitudinal channel to which a sliding structure is coupled to which a second end of the elongated profile is attached; where this second end is opposite the first end of the elongated profile.

The second retractable stop is coupled to the sliding structure by means of an articulated connection linked to a spring element, such as an elastic plate or a spring, which is configured to achieve the retractable effect of said second retractable stop when it rotates in one direction to allow the entry of new sheets into the magazine.

In one embodiment of the invention the box forming machine comprises at least two loaders, at least two lines for transporting die-cut sheets and at least two forming stations with two cores and two moulds; where the conveyor device includes two drive mechanisms that are coupled, respectively, to the two chains of the conveyor device; and where said drive mechanisms are located in offset positions with respect to each other, which implies that the different operations in the transfer of the sheets and the formation of the two boxes are also offset.

Thanks to the new system for transferring the sheets, it is possible to substantially increase the production of the boxes, so that with the transfer system, as a first improvement of the invention, it acts, through its suction cup device, extracting from the stack of the loader or several loaders, so that the sheets are then guided horizontally to the forming station or forming stations.

A second improvement that is related to the first improvement and the speed of machine formation that requires having effective sheet loaders, when ensuring that the sheets stacked therein must always be perfectly available for the suction cup devices and this requires that said chargers be continuously fed with new stacks of sheets; where said second improvement refers to the charger assembly or the described chargers.

It should be noted that when the suction cups access the stack of sheets to suck the first one, said suction cups exert a certain thrust on this stack, so it is necessary that in some way on the side opposite the first sheet where the last sheet is located, a force is applied to counteract this thrust and ensure the good stability of said stack of sheets while the sheets are being reloaded. This problem is solved with the retaining device described.

Below, to facilitate a better understanding of this descriptive report and as an integral part of it, a series of figures are attached in which the object of the invention has been represented for illustrative and non-limiting purposes.

Brief description of the figures

Figure 1.- Shows a perspective view of a cardboard box forming machine, object of the invention. The machine includes at least one loader and a system for transferring the die-cut sheets.

Figure 2.- Shows a perspective view of a conveyor device that is part of the system for transferring die-cut sheets.

Figure 2a.- Shows an elevation view of what is represented in Figure 2.

Figure 3.- Shows a perspective view of a charger that is part of the machine of the invention.

Figure 4.- Represents a perspective view of two loaders in parallel, which are configured to support two groups or stacks of sheets.

Figure 4a.- Shows a perspective view of a part of the charger with a stack of die-cut sheets.

Figure 5.- Shows a plan view of the loader that supports a stack of stacked sheets arranged in vertical planes.

Figure 6.- Represents a perspective view of a second retaining device for temporarily holding the sheets stacked in the magazine during the loading of new sheets into said magazine.

Figure 6a.- Represents an exploded perspective view of what is represented in the figure 6.

Figure 7.- Represents a schematic view showing the different phases and devices during the transfer of each die-cut sheet until it reaches the box forming station.

Description of an exemplary embodiment of the invention

Considering the numbering adopted in the figures, the cardboard box forming machine 1 shown in figure 1 comprises at least one box forming station 2 that includes at least one mould 41 and a core 40 located above the mould 41; where for the formation of each box, the core 40 descends downwards dragging a die-cut sheet 3 until it is introduced into the mould 41 in which the box is finally formed.

Machine 1 also includes the transfer system for the die-cut sheets 3, from which the cardboard boxes are formed, as referred to in the preceding paragraph.

The transfer system comprises at least one suction cup device 4, at least one conveyor device 5 arranged downstream of the suction cup device 4.

On the other hand, the machine 1 includes at least one loader 6 that is configured to hold the sheets 3 stacked in substantially vertical planes; where said loader 6 integrates a first centered retaining device 7 and two second lateral retaining devices 8 in parallel; where the three devices 7, 8 are configured to hold and push the sheets 3 stacked in the loader 6 in different phases, so that when the first retaining device 7 acts the two second devices 8 are deactivated and vice versa.

The stack P of sheets 3 supporting the magazine 6 includes a first sheet and a last sheet which is in contact with the first 7 or the two second retaining devices 8, as will be described in detail later; where the first and the last sheets 3 are arranged in opposite vertical planes of the stack P of sheets 3.

The first retaining device 7 is conventional and is coupled on a first longitudinal guide 9 centered, on which the stack P of sheets 3 rests. Said first retaining device 7 comprises a first stop 10 linked to a first linear actuator 11, such as a magnetic cylinder, such that said first stop O is configured so that the stack P of sheets 3 rests thereon by its last sheet.

The two second retaining devices 8 only act during the unitary loading of new sheets 3 in the magazine 6, so that when this does not occur, the first conventional retaining device 7 acts, holding the stack P by its last sheet 3.

During activation of the sheet transfer system 3, the suction cup device

4 picks up and transfers each first sheet of the stack P of sheets 7 to longitudinal bars 12, such that said suction cup device 4 is configured to transfer the sheets 3 individually from the loader 6 until they are resting on the longitudinal bars 12 that are located above the conveyor device

5 on a horizontal plane.

The conveyor device 5 is responsible for dragging each sheet 3 individually from the longitudinal bars 12 to the forming station 2 above the mold 41 and below the core 40.

The conveyor device 5 comprises a frame 13 to which a first pair of driving sprockets 14 are coupled, integral with a transverse drive shaft 15, and a second pair of driven sprockets 16, which receive transmission from the first pair of sprockets 14 by means of two longitudinal chains 17 in parallel; where the rotation of the transverse shaft 15 is carried out by means of a motor-reducer 18.

In another embodiment of the invention, the possibility has been provided of including two independent transverse drive shafts that separately transmit their rotations to the respective first pinions 14, so that in this case two motor-reducers 18 are included to transmit their rotary movements to the respective transverse drive shafts.

The conveyor device 5 further comprises at least one drive mechanism.

19 which is fixed to one of the two chains 17 by means of a connecting body 20.

The drive mechanism 19 comprises a vertical guide 21 to which a skate portion 22 integral with the connector body 20 is coupled, such that during the movement of the chains 17, the skate portion 22 together with the connector body 20 move guided along the vertical guide 21, while the entire assembly of the drive mechanism 19 moves dragged by the chain 17.

The vertical guide 21 is connected to a slide 23 fitted in a lower guide 24 that runs parallel along the chain 17 below it; said lower guide 24 is a fixed element integral with the frame 13 of the conveyor device 5.

An adjustable support 25 is attached to the vertical guide 21, on which a pusher piece 26 is coupled, by means of which each sheet 3 is moved, when it is supported on the longitudinal bars 12, to the forming station 2. Said pusher piece 26 is fixed at one end of the adjustable support 25, and can also have different shapes and widths.

The adjustable support 25 has a horizontal bar configuration that can be fixed in different positions with respect to the vertical guide 21 and parallel to the chain 17.

The adjustable support 25 of the conveyor device 5 is fixed to the vertical guide 21 by means of a plate 37 and screws 38 that thread into the vertical guide 21, while the adjustable support 25 has an end slot 39 through which said screws 38 pass to allow the mobility of the adjustable support 25.

Thus, the mobility of the respective chain 17 displaces the entire drive mechanism 19 guided in the lower guide 24, such that said drive mechanism 19 alternately travels the upper and lower branch of the chain 17, maintaining the movement of the pusher piece 26 and its adjustable support 25 stable in the same longitudinal and horizontal alignment without variation in its height.

When the drive mechanism 19 is associated with the lower branch of the chain 17 the connector body 20 is located in a lower location, while when the The drive mechanism 19 is associated with the upper branch of the chain 17, then the connector body 20 is located in an upper location along said vertical guide 21, with the adjustable support 25 and the pusher piece 26 always being kept at the same height without variation.

The movement of the pusher piece 26 (forward and backward) always occurs on the same line or plane, but driven by a chain 17, like traditional systems, but with the major difference that in the latter the pusher piece 26 follows the ascending and descending path of the upper branch and the lower branch of the chain 17 itself as it is normally linked to one of its links, which does not occur in the invention in question, as described above.

As previously mentioned, the pusher piece 26 is mounted on the adjustable support 25 (so that it can be positioned where desired depending on the box format), which in turn is linked to the vertical guide 21 which is movable by the chain 17; where the connector body 20 moves along the vertical guide 21.

The vertical guide 21 moves the entire drive mechanism 19, but it is said vertical guide 21 which allows compensation for changes in height of the connector body 20 while the chain 17 produces the movement of the entire drive mechanism 19.

Figures 2 and 2a show the entire assembly of the conveyor device 5, which can feed two forming stations 2 of the machine 1. Specifically, a first drive mechanism 19 which is located at the rear, hooked to one of the two chains 17 in parallel, and a second drive mechanism 19 which is located at the front, hooked to the other paired chain 17; all this to achieve an alternating operation to avoid operating problems in the sense that the same operations do not coincide at the same time throughout the process of transferring the sheets 10 and forming the two boxes.

The operation of the machine 1 is substantially optimized by being able to efficiently feed the respective stack P of sheets 3 that is located in the loader 6, so that as previously mentioned during said feeding the first retention device 7 is deactivated, delaying its first stop 10, leaving by pushing the stack P of sheets 3, and the two second retention devices 8 are activated, which include second retractable stops 27 that push said stack 3 until the loading of new sheets 3 is finished, at which time the first retention device 7 is activated again and the two second retention devices 8 are deactivated.

As shown more clearly in Figure 6, each second retaining device 8 comprises a second linear actuator 28 coupled to a support 29 integral with a side plate 30 integral with a frame 31 of the magazine 6.

A rod of the linear actuator 28 is connected to a first end of an elongated profile 32 guided in a hollow of a body 33 which is fixed to a fixed guide 34 integral with the side plate 30; where said fixed guide 34 includes a longitudinal channel 34a in which a sliding structure 35 is coupled to which a second end of the elongated profile 32 is connected; where this second end is opposite to the first end of the elongated profile 32.

The second retractable stop 27 is coupled to the sliding structure 35 by means of an articulated connection linked to a spring element, such as a helical spring 36 or an elastic plate 36'; all this to achieve the retractable effect of said second retractable stop 27 when it rotates in one direction to allow the entry of the new stack of sheets introduced into the magazine 6.

When the two second retaining devices 8 of each magazine 6 are activated, the second retractable stops 27 are moved by means of the second linear actuators 28.

The function of the second retaining devices 8 is to retain the stacked sheets 3, and more specifically that the second retractable stops 27 allow the stack of sheets 3 to be kept stable with a certain tightness while new die-cut sheets 3 are being loaded in correspondence with a rear face corresponding to the last sheet of the stack P of sheets 3 that rests on the second retractable stops 27; where a front face corresponding to the first sheet of said stack P of sheets 3 corresponds to an area where the suction cup device 4 picks up the sheets 3 to transfer them to the bars longitudinal 12 arranged above the conveyor device 5.

Therefore, each second retractable stop 27 functions as a ratchet allowing the introduction or entry of sheets 3 according to a direction C perpendicular to the stacked sheets 3 as shown in figure 5; where said second retractable stop 27 tilts in one direction when the sheets are introduced by means of a turn, then recovering its position by turning in the opposite direction when the sheets 3 have been introduced in the last position in the stack P of sheets 3 by the action of the spring element 36, 36'.

The spring element 36, 36' tends to keep said second retractable stop 27 in a stable position, so that each time the sheets 3 are introduced into the stack P of sheets 3 of the magazine 6, said spring element 36, 36' is tensioned. The tightening of the sheets 3 in the magazine 6 remains stable perpendicularly to them during the loading of new sheets 3. Obviously when the first retaining device 7 acts, the tightening of the stack P of sheets 3 also remains stable.

Claims

1.- System for transferring die-cut sheets in a cardboard box forming machine, where the transfer of the sheets (3) is carried out along at least one transport line from at least one loader (6) in which the sheets (3) are stacked in vertical planes, to a forming station (2) of the machine (1); and where the transfer system collects the sheets (3) individually from the loader (6) to deposit them on longitudinal bars (12); the transfer system comprising a conveyor device (5) that drags the sheets (3) individually to the forming station (2); characterized in that:

- the conveyor device (5) comprises a frame (13) on which a first pair of driving sprockets (14) integral with a transverse drive shaft (15) and a second pair of driven sprockets (16) are coupled, which receive transmission from the first pair of sprockets (14) by means of two longitudinal chains (17) in parallel; where the longitudinal bars (12) are located above the conveyor device (5);

- the conveyor device (5) further comprises at least one drive mechanism (19) which is fixed to one of the two chains (17) by means of a connecting body (20); wherein the drive mechanism (19) comprises a vertical guide (21) to which the connecting body (20) is coupled and guided;

- the vertical guide (21) is connected to a slide (23) which is coupled to a lower guide (24) which runs parallel along the chain (17) below it; where said lower guide (24) is a fixed element integral with the frame (13) of the conveyor device (5);

- an adjustable support (25) is attached to the vertical guide (21) on which a pusher piece (26) is coupled, by means of which each sheet (3) moves when it is supported on the longitudinal bars (12), to the forming station (2); where during the mobility of the chains (17), the connecting body (20) moves guided along the vertical guide (21) guided in the lower guide (24), while the entire assembly of the drive mechanism (19) is configured to move dragged by the chain (17) keeping the height of the adjustable support (25) and its pusher piece (26) constant.

2.- System for transferring die-cut sheets in a forming machine Cardboard boxes, according to claim 1, characterized in that the adjustable support (25) of the drive mechanism (19) has a horizontal bar configuration that can be fixed in different positions on the vertical guide (21), while the pusher piece (26) is fixed at one end of the adjustable support (25).

3.- System for transferring die-cut sheets in a cardboard box forming machine, according to any one of the preceding claims, characterized in that the first pair of driving pinions (14) are integral with a single transverse drive shaft (15) connected to a motor-reducer (18).

4.- System for transferring die-cut sheets in a cardboard box forming machine, according to any one of the preceding claims 1 or 2, characterized in that the first pair of pinions (14) are integral with respective independent drive shafts separately connected to respective motor reducers (18); where the transmission to the first pair of pinions (14) is carried out separately and independently.

5.- Cardboard box forming machine, comprising the system for transporting die-cut sheets (3) described in any one of the preceding claims, and also comprising the loader (6) that includes a first retaining device (7) for holding the stack (P) of sheets (3) stacked by its rear face corresponding to the last sheet, opposite a front face of the stack (P) that corresponds to a first sheet prepared to be picked up by the suction cup device (4); where the stack (P) of sheets is supported on a first longitudinal guide (9) centered on which the first retaining device (7) is coupled, which comprises a first linear actuator (11) to which a first stop (10) is connected that is configured to retain the stack (P) of sheets by its rear face; It is characterized in that the charger (6) also includes two second retaining devices (8) for holding the stack (P) of stacked sheets by two opposite sides of its rear face by means of second retractable stops (27) that form part of the second retaining devices (8); where the second retaining devices (8) are configured to be activated during the feeding of sheets (3) from the charger (6), at which time the first device is deactivated; and where when the first retaining device (7) is activated, the second retaining devices are deactivated.

6.- Cardboard box forming machine, according to claim 5, characterized in that:

- each of the second retaining devices 8 comprises a second linear actuator (28) coupled to a support (29) integral with a side plate (30) integral with a frame (31) of the charger (6); where a rod of the linear actuator (28) is connected to a first end of an elongated profile (32) guided in a recess of a body (33) which is fixed to a fixed guide (34) integral with the side plate (30);

- the fixed guide (34) includes a longitudinal channel (34a) to which a sliding structure (35) is coupled, to which a second end of the elongated profile (32) is attached; where this second end is opposite the first end of the elongated profile (32).

7.- Cardboard box forming machine, according to the preceding claim 5 or 6, characterized in that the second retractable stop (27) is coupled to the sliding structure (35) by means of an articulated connection linked to a spring element, which is configured to achieve the retractable effect of said second retractable stop (27) when it rotates in one direction to allow the entry of new sheets into the loader (6); where said spring element is an element selected from a helical spring (36) and an elastic plate (36').

8.- Cardboard box forming machine, according to any one of the preceding claims 5 to 7, characterized in that it comprises at least two loaders (6), at least two lines for transporting die-cut sheets (3) and at least two forming stations (2) with two cores (40) and two moulds (41); where the conveyor device (2) includes two drive mechanisms (19), which are coupled, respectively, to the two chains (17) of the conveyor device (5); and where said drive mechanisms (19) are located in positions out of phase with respect to each other, which implies that the different operations in the transfer of the sheets (3) and the formation of the two boxes are out of phase.