Counter ejector for a converting machine, and corresponding converting machine

Abstract

The present invention relates to a counter ejector (17) for a converting machine (10) for making packaging elements from sheet material, the counter ejector comprising a lifting device (21) arranged in close proximity to the counter ejector's inlet (22) through which packaging elements are introduced, a separator (24) for forming a batch of packaging elements, and a conveyor (25) for transporting the batch of packaging elements towards an exit section (E) of the counter ejector. The invention further pertains to a converting machine (10) comprising a such counter ejector (17).

Description

[0001] IMPROVED COUNTER EJECTOR FOR A CONVERTING MACHINE, AND CONVERTING MACHINE THEREOF TECHNICAL FIELD OF THE INVENTION

[0002] The present invention concerns the field of converting machines for making packaging elements. The invention relates particularly to a counter ejector for a converting machine for making packaging elements from sheet material. It also pertains to a converting machine comprising a such counter ejector.

[0003] BACKGROUND OF THE INVENTION

[0004] Converting machines, such as flexo folder-gluers, are used to produce packaging elements like folding boxes. These machines comprise various work modules to process sheets of corrugated cardboard or similar materials. Among these modules, a flexo folder-gluer includes a counter ejector, also called a counter module or simply counter, placed after the folding-gluing module. The role of this peripheral is to form batches of a preset number of folding boxes. The batches are then conveyed towards an exit section, where they are forwarded to other binding and / or clustering means, such as a palletizer, which organizes several batches into stacks suitable for placing on pallets.

[0005] To support and move the batches, the counter ejector includes a lifting device, also known as an elevator, positioned near the inlet of the counter ejector. Its function is to work in conjunction with a separator that forms the batches, and to move the batches towards a conveyor, onto which they are transferred by the separator.

[0006] However, a converting machine is typically used to produce boxes of varying widths or lengths. A problem arises with the elevator when long boxes are made. Indeed, when long boxes are produced, the packagingelements’ supporting means of the elevator must be long enough to properly support the boxes along their entire length. Otherwise, there is a risk of the stack of boxes tilting. On the other hand, a long elevator is not desirable when short sheets are processed because the boxes must then be conveyed over a longer distance, which degrades the overall productivity of the converting machine.

[0007] To solve this problem, it is known to provide an elevator that may be moved longitudinally in the sheet transport direction (i.e. the horizontal direction that goes from the inlet to the outlet of the counter). A such solution is for instance described in US 10,822,188 B2.

[0008] However, the need to move the elevator longitudinally increases the bulk of the counter ejector, and consequently that of the converting machine. Also, this design makes the elevator heavier, because of the rails and guides that are required to move the elevator, which implies greater energy consumption to move it up and down and, consequently, higher production costs.

[0009] SUMMARY OF THE INVENTION

[0010] The present invention aims to remedy these drawbacks. Accordingly, it is an object of the invention to provide a counter ejector that may process both long and short boxes without degrading the performance of the converting machine, increasing its bulk, or inducing higher production costs.

[0011] In order to achieve this object, a first aspect of the invention pertains to a counter ejector for a converting machine for making packaging elements from sheet material, the counter ejector comprising a lifting device arranged in close proximity to the counter ejector’s inlet through which packaging elements are introduced, a separator for forming a batch of packaging elements, and a conveyor for transporting the batch of packaging elementstowards an exit section of the counter ejector. Advantageously, the lifting device comprises at least one arm for supporting at least one packaging element, the arm comprising a body and an extension linked to the body, the extension being displaceable between a retracted position and an extended position, thereby allowing the length over which a packaging element can be supported to be modified.

[0012] In one embodiment, the length over which a packaging element can be supported when the extension is in the retracted position corresponds to the body’s length.

[0013] In one embodiment, the arm extends longitudinally in a sheet transport direction. That way, optimal support for production of long boxes is provided.

[0014] In one embodiment, the extension is connected to an actuator which is attached to the body and configured to displace the extension from the retracted position to the extended position, and vice versa.

[0015] In one embodiment, the body as a U-shaped profile comprising a top surface and two lateral walls, the actuator being arranged under the top surface and between the lateral walls.

[0016] In one embodiment, the actuator is pneumatic.

[0017] In one embodiment, the extension is a flap linked to the body by means of an axis about which the flap rotates when it is displaced from the retracted position to the extended position, and vice versa. This design allows the lifting device’s weight to be minimized.

[0018] In one embodiment, the flap forms a right angle with the body when it is in the retracted position.In one embodiment, the lifting device comprises four arms provided with an extension. This implementation further minimizes the lifting device’s weight.

[0019] A second aspect of the invention pertains to a converting machine for making packaging elements from sheet material, the converting machine comprising a counter ejector as described above.

[0020] In one embodiment, the converting machine comprises a production management system comprising at least one processor and a memory that are configured to:

[0021] • obtain a value of the length of a sheet to be processed; and

[0022] • cause the displacement of the extension in the retracted position or in the extended position in accordance with said value

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will now be described with reference to the appended drawings, in which:

[0025] - Figure 1 is a schematic view of a converting machine according to an embodiment of the invention;

[0026] - Figure 2 is a schematic view of some elements of a counter ejector according to the invention;

[0027] - Figure 3A is schematic view of a lifting device of a counter ejector according to the invention;

[0028] - Figure 3B is schematic view of a lifting device of a counter ejector according to the invention; and

[0029] - Figure 4 is a schematic view of some elements of a lifting device of a counter ejector according to the invention.

[0030] DETAILED DESCRIPTION

[0031] A converting machine 10 for making packaging elements from sheet formed material according to an embodiment of the present invention is illustratedin Figure 1. In this embodiment, the converting machine 10 takes the form of a flexo folder-gluer (FFG) that is used to produce folding boxes from sheets of corrugated cardboard or other similar paper-based material. It thus comprises a plurality of different work modules to print, cut, crease, fold and glue sheets, and a counter ejector to form batches of folding boxes. The invention, however, is applicable to other types of converting machine which comprise a counter ejector.

[0032] From its entry section, and in the direction T in which the sheets / boxes are transported, which is horizontal and thus perpendicular to a vertical direction going from the ground to the top of the machine, the converting machine 10 comprises: a pre-feeder 11 , a feeder module 12, a printing module 13, which typically comprises several flexographic printing modules 14, a slotter and / or a rotary die-cutter 15, a folding-gluing module 16, and a counter ejector 17.

[0033] Preferably, the converting machine 10 according to the invention also comprises, at its extreme downstream end, a palletizer (not illustrated) to organize batches of boxes into stacks which are placed on pallets. It is also equipped with a production management system 18, which includes at least one data processor and a memory.

[0034] Figure 2 illustrates a schematic view of the counter ejector 17 according to an embodiment of the invention. It conventionally includes a lifting device 21 arranged very near and below the counter ejector’s inlet 22, through which folding boxes output by the folding-gluing module 16 are introduced. In a common configuration, the lifting device 21 is fixed to, or it nearly touches, an anterior wall 23 of the counter ejector 17.

[0035] To support the boxes that fall from the inlet 22, the lifting device 21 conventionally comprises a plurality of arms. These arms extendlongitudinally, i.e. , in the sheets / boxes transport direction T. Preferably, the inlet 22 takes the form of a slit through which the boxes output by the foldinggluing module 16 are introduced.

[0036] Moreover, like most other known counters, the counter ejector 17 according to the invention comprises a separator 24 for forming, i.e., grouping, batches of boxes. It is also commonly equipped with a conveyor 25 for transporting the batches of boxes towards its exit section E. During operation, the lifting device 21 continuously moves up and down. It ascends to receive a batch of boxes formed by the separator 24, thereby preventing the batch from falling freely from a great height, and it descends to align with the conveyor 25. At this point, the separator 24 moves longitudinally (i.e., in the transport direction T) to transfer the batch supported by the lifting device 21 onto the conveyor 25.

[0037] Figures 3A, 3B show schematic views of the lifting device 21 from above, and Figure 4 shows a schematic view of some of some of its components from below.

[0038] As is apparent in these figures, the lifting device 21 comprises at least one arm 31 that includes a body 32 and an extension 33. The extension is linked to the body 31 and is displaceable between a retracted position and an extended position. That is, the extension 33 is movable with respect to the body. As a result, the length over which boxes are supported may be modified, particularly to allow optimal productivity of the converting machine when producing short boxes, and to prevent the risk of the stack of boxes tilting when producing long boxes.

[0039] In one exemplary embodiment of the invention, the lifting device 21 comprises four such extendable arms 31 with a body 32 and a linked extension 33. The extensions 33 of all extendable arms 31 are similarlydisplaceable between a retracted and an extended position. However, the lifting device 21 may include fewer or more extendable arms 31. The extendable arms 31 are arranged between two lateral arms 34 that only include a body, i.e., with no linked extension. This design balances minimizing the weight of the lifting device 21 and preventing the stack of boxes from tilting.

[0040] As best seen in Figure 4, the displacement of the one or more extensions 33 is controlled using one or more actuators 35. In other terms, each extension 33 of each extendable arm 31 is connected to a dedicated actuator 35, preferably pneumatic, which is arranged and configured to displace the extension 33 to which it is attached from the retracted position to the extended position, and vice versa. To allow arrangement of the actuators 35, the body 32 of each extendable arm 31 has a U-shaped profile formed by a top surface and two lateral walls. An actuator 35 is advantageously arranged under the top surface and between the lateral walls of the body 32 of an extendable arm 31.

[0041] In one exemplary embodiment of the invention, each extension 33 of each extendable arm 31 is in the form of a flap, i.e., a rotative element. Specifically, an extension 33 is linked to the body 32 of an extendable arm 31 by means of an axis 36 about which it rotates to move between the retracted position and the extended position. When the extension 33 is in the retracted position, it forms a right angle with the body 32 of the arm 31 , as illustrated in Figures 3B and 4. In this configuration, the support length for boxes is minimal, corresponding to the length of the body 32 alone. This position is suitable for processing short boxes.

[0042] Conversely, an extension 33 forms an angle of 180° with the body 32 of an extendable arm 31 when the extension 33 is in the extended position, as illustrated in Figure 3A. In this configuration, the support length for boxes ismaximized, roughly corresponding to the combined length of the body 32 and the extension 33. This position is advantageous for minimizing the risk of the stack of boxes tilting when processing long boxes.

[0043] The converting machine 10 according to the invention is further configured as follows. When an operator specifies a new production job, the length of the sheets to be processed is set either manually by the operator or automatically according to the specified job. The production management system 18 then obtains, i.e., retrieves, the value of the length of the processed sheets. Next, the production management system 18 determines the position of the extensions 33 of the extendable arms 32 of the lifting device 21 of the counter ejector 17 based on the length of the processed sheets. It then causes the extensions 33 of the extendable arms 32 to be displaced accordingly.

[0044] For example, if the production management system 18 determines that the length of the processed sheets is less than a predefined length (e.g. 1m), which value is preset in accordance with the counter’s or the converting machine’s dimensions, it concludes that short sheets are processed. It then causes displacement of the extensions 33 of the extendable arms 32 of the lifting device 21 of the counter ejector 17 in the retracted position.

[0045] Conversely, if the production management system 18 determines that the length of the processed sheets is greater than the predefined length, it determines that long boxes are processed, and it causes the displacement of the extensions 33 of the extendable arms 32 of the lifting device 21 of the counter ejector 17 in the extended position.

[0046] Thus, no manual intervention is necessary to set the position of the extension 33 of the extendable arms 32. This automation allows theconverting machine 10 according to the invention to produce both short and long packaging elements, such as folding boxes, with optimal productivity.

Claims

CLAIMS1. A counter ejector (17) for a converting machine (10) for making packaging elements from sheet material, the counter ejector comprising a lifting device (21) arranged in close proximity to the counter ejector’s inlet (22) through which packaging elements are introduced, a separator (24) for forming a batch of packaging elements, and a conveyor (25) for transporting the batch of packaging elements towards an exit section (E) of the counter ejector, wherein the lifting device comprises at least one arm (31) for supporting at least one packaging element, the arm comprising a body (32) and an extension (33) linked to the body, the extension being displaceable between a retracted position and an extended position, thereby allowing the length over which a packaging element can be supported to be modified.

2. The counter ejector (17) according to claim 1, wherein the length over which a packaging element can be supported when the extension (33) is in the retracted position corresponds to the body’s (32) length.

3. The counter ejector (17) according to any one of the preceding claims, wherein the arm (31) extends longitudinally in a sheet transport direction (T).

4. The counter ejector (17) according to any one of the preceding claims, wherein the extension (33) is connected to an actuator (35) which is attached to the body (32) and configured to displace the extension from the retracted position to the extended position, and vice versa.

5. The counter ejector (17) according to claim 4, wherein the body as a U-shaped profile comprising a top surface and two lateral walls, the actuator (35) being arranged under the top surface and between the lateral walls.

6. The counter ejector (17) according to one of claims 4-5, wherein the actuator (35) is pneumatic.

7. The counter ejector (17) according to any one of the preceding claims, wherein the extension (33) is a flap linked to the body by means of an axis (36) about which the flap rotates when it is displaced from the retracted position to the extended position, and vice versa.

8. The counter ejector (17) according to claim 7, wherein the flap forms a right angle with the body (32) when it is in the retracted position.

9. The counter ejector (17) according to any one of the preceding claims, wherein the lifting device (21) comprises four arms (31) provided with an extension (33).

10. A converting machine (10) for making packaging elements from sheet material, wherein it comprises a counter ejector (17) according to any one of the preceding claims.

11. The converting machine (10) according to claim 10, wherein it comprises a production management system (18) comprising at least one processor and a memory that are configured to:• obtain a value of the length of a sheet to be processed; and• cause the displacement of the extension (33) in the retracted position or in the extended position in accordance with said value.

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