阅读说明：本技术 夹持器组件，用于从片状材料回收布局的装置及用于从片状材料的废料分离布局的方法 (Gripper assembly, device for recovering an arrangement from a sheet material and method for separating an arrangement from waste of a sheet material ) 是由 P·霍尼克 Y·鲁兰 R·瓦尔特里奥 于 2020-03-17 设计创作，主要内容包括：提供了用于从片状材料(12)回收布局(22)的夹持器组件。它包括夹持器体(32)的真空夹持器(26),该夹持器体上布置有一阵列的气流开口(34a,34b)。与所述布局(22)的一个或多于一个的坯料(20)相关联的气流开口(34a)被选择性地打开,并且与所述板状材料(12)的废料(28)相关联的气流开口(34b)被选择性地关闭。另外,描述了包括该夹持器组件的用于从片状材料(12)回收布局(22)的装置。进一步地,解释了用于从片状材料(12)的废料(28)分离布局(22)的方法。(A gripper assembly for recovering a layout (22) from a sheet material (12) is provided. It includes a vacuum holder (26) having a holder body (32) with an array of gas flow openings (34 a, 34 b) disposed therein. The air flow openings (34 a) associated with the one or more blanks (20) of the layout (22) are selectively opened and the air flow openings (34 b) associated with the waste (28) of the sheet material (12) are selectively closed. In addition, an apparatus for recovering a layout (22) from a sheet material (12) is described that includes the gripper assembly. Further, a method for separating a layout (22) from a waste (28) of sheet material (12) is explained.)

1. Gripper assembly (27) for recovering a layout (22) from a sheet material (12), in particular from paper or cardboard, comprising

A conveying unit (14) for supplying the sheet material (12), wherein the conveying unit (14) is equipped with a vacuum system (15) for holding the sheet material (12) on the conveying unit (14), and

a vacuum gripper (26) adapted to engage sheet material (12) provided by the delivery unit (14), the vacuum gripper (26) comprising a gripper body (32) having an array of airflow openings (34 a, 34 b) arranged thereon, each opening (34 a, 34 b) being adapted to grasp at least a portion of the sheet material (12) by applying a vacuum force thereto,

wherein the air flow openings (34 a, 34 b) associated with the one or more blanks (20) of the layout (22) are selectively opened and the air flow openings (34 a, 34 b) associated with the waste (28) of the sheet material (12) are selectively closed.

2. Gripper assembly (27) according to claim 1, characterized in that said array of air flow openings (34 a, 34 b) covers a predetermined maximum format of the sheet material (12) to be handled by the vacuum gripper (26).

3. Gripper assembly (27) according to claim 1 or 2, characterized in that the array of air flow openings (34 a, 34 b) is arranged on a gripping side of the gripping body (32), wherein the gripping side is provided with a hood (36), the hood (36) selectively covering the air flow openings (34 b) associated with the waste material (28) and selectively not interfering with the air flow openings (34 a) associated with the one or more blanks (20) of the layout (22).

4. Gripper assembly (27) according to claim 3, characterized in that the gripping side of the vacuum gripper (26) is magnetic, in particular wherein a magnetic cover (38) is attached to the gripping side of the vacuum gripper (26).

5. Gripper assembly (27) according to claim 4, characterized in that the cover (36) is positioned between the magnetic side of the vacuum gripper (26) and a magnetic sheet (40) covering the cover (36) on its side opposite the vacuum gripper (26).

6. A gripper assembly (27) according to any one of the preceding claims, characterized in that said conveying unit (14) comprises several suction openings (15 a) fluidly connected to said vacuum system (15) such that said sheet material (12) can be held on said conveying means (14) by sucking air by said vacuum system (15) through said suction openings (15 a), in particular wherein the configuration of said suction openings (15 a) is independent of the size and/or shape of said sheet material (12) to be treated.

7. Gripper assembly (27) according to any of the preceding claims, characterized in that the vacuum system (15) is configured such that the vacuum force applied by the vacuum system (15) to one or more blanks is smaller than the vacuum force applied by the vacuum gripper (26) to one or more blanks.

8. Device (10) for recovering a layout (22) from a sheet-like material (12), in particular from paper or cardboard, comprising

Gripper assembly (27) according to any one of the preceding claims, wherein the sheet material (12) comprising the layout (22) and waste material (28) is to be provided by the transport unit (14) of the gripper assembly (27), and wherein the vacuum gripper (26) of the gripper assembly (27) is connected to a handling unit (24), and

a layout storage unit (18) on which one or more blanks (20) of the layout (22) retrieved from the sheet material (12) can be positioned.

9. The apparatus (10) according to claim 8, characterized by one or more additional vacuum grippers (26 a), wherein each additional vacuum gripper (26 a) is connected to a respective additional handling unit (24 a).

10. The device (10) according to claim 8 or 9, characterized in that at least one of said handling unit (24) and said additional handling unit (24 a) comprises an industrial robot adapted to handle said respective vacuum gripper (26, 26 a) within a predetermined range of motion.

11. The device (10) according to any one of claims 8 to 10, wherein the blank storage unit (18) is a stacking unit.

12. Method for separating a layout (22) from a sheet-like material (12), in particular from a waste material (28) of paper or cardboard, comprising the following steps

a) Providing a sheet material (12) on a transport unit (14), wherein the sheet material (12) comprises a layout (22) with one or more blanks (20) and waste (28), and wherein the sheet material (12) is held on the transport unit (14) by a vacuum system (15) of the transport unit (14),

b) -gripping the one or more blanks (20) by a vacuum gripper (26), preferably a vacuum gripper (26) of a gripper assembly (27) according to claims 1 to 7, without cooperation with the waste (28), and thereafter,

c) separating the one or more blanks (20) from the scrap (28).

13. Method according to claim 12, characterized in that after step c) the blanks (20) are moved to a blank storage unit (18), in particular a stacking unit or another transport unit.

14. Method according to claim 12 or 13, characterized in that during step b) the vacuum gripper (26) is positioned on the sheet material (12), wherein the vacuum gripper (26) selectively grips the blank (20) without cooperating with the waste (28).

Technical Field

The present invention relates to a gripper assembly for a retrieval arrangement from sheet material, in particular from paper or cardboard, comprising a transport unit for providing the sheet material and a vacuum gripper having a gripper body on which an array of air flow openings is arranged, wherein each opening is adapted to grip at least a portion of the sheet material by applying a vacuum force thereto.

Further, the invention relates to an apparatus for recovering a layout from a sheet material, in particular from paper or cardboard, comprising a gripper assembly of the above-mentioned type, wherein the vacuum gripper of the gripper assembly is connected to a handling unit, and a layout storage unit on which one or more blanks of a layout recovered from the sheet material can be positioned.

Additionally, the present invention relates to a method of separating an arrangement from a sheet material, in particular from waste material of paper or paperboard.

Background

In a production line for producing paper or board products, the sheet material is usually provided in a single sheet or in a roll form. The sheet material is then cut, for example on a laser cutter, but not every portion of the sheet material is required for the final product. It is therefore necessary to separate the part of the end product that is needed, the so-called layout, from the part of the end product that is not needed, the so-called waste.

More precisely, a layout is defined as a usable portion of a sheet material, which may generally consist of a variety of blanks. The separation process is also referred to as stripping or blanking.

Since the paper and paperboard products have become more and more individualized, customers are demanding a large variety of paper or paperboard products to be produced, with a relatively low number of products to be produced per variety.

Therefore, the manufacturer of the paper or paperboard product must be able to profit from the production of the paper or paperboard product in small batches or batches. In other words, a short run of production needs to be profitable.

With corresponding production machines, gripper assemblies and devices, a shorter setup time is required to prepare the machine for a new or subsequent production batch. The changeover time should be as short as possible between the production of two different batches.

These requirements have been generally met in the paper or cardboard cutting field by using laser cutters, but the set-up time and changeover time for stripping or blanking is still high.

The tooling of the known stripping or blanking device is also relatively costly, since the tooling needs to be specifically adapted to the layout to be stripped. An alternative to such tooling is manual operation, which has no significant cost advantage.

It is therefore an object of the present invention to provide a gripper assembly, a device for recovering a layout device from a sheet material, and a corresponding method, which are both suitable for small batch production, i.e. which both provide short setup times and short changeover times. This also means that small batch production will be achieved in a competitive, i.e. low cost, manner.

Disclosure of Invention

This problem is solved by a gripper assembly according to claim 1. The transport unit has a vacuum system allowing to safely transport sheet material having any shape and size. Additionally, such a transport unit is capable of providing sheet material to an associated vacuum gripper in a precise manner. Further, the transport unit can be integrated smoothly into existing or planned material flows. In the case of a vacuum gripper, the air flow openings associated with the layout will catch one or more blanks of the layout, while the air flow openings associated with the waste material will not cooperate there. For this reason, determining the layout-related air flow openings and the scrap-related air flow openings is an active process, which takes place before the actual clamping operation starts. Thus, the layout can be easily separated from the waste. The vacuum gripper is particularly adapted to the geometry of the layout to be separated from the respective waste material by selectively opening the corresponding gas flow openings and selectively closing all the gas flow openings associated with the waste material. This can be done easily and quickly, resulting in a reduction in setup and changeover times. Such a vacuum gripper is therefore very suitable for producing individualized paper or board products in small quantities at a reasonable cost.

The gripper assembly according to the invention can be used for sheet material, which is provided in the form of a single sheet or a roll. The above effects and advantages can be achieved for both forms. The vacuum holder preferably uses a sheet material in the form of a single sheet. Such material may be designated as cut into sheets.

Typically, the sheet material to be processed by the gripper assembly is previously processed manually in a cutting machine where the boundaries between the layout and the scrap are cut. That is, the gripper assembly is disposed downstream of the cutter with respect to the direction of travel of the sheet. The cutter is preferably a laser cutter.

In this case, the transport unit of the gripper assembly may be shared with the laser cutter, i.e. the same transport unit is used in both the cutter and the gripper assembly.

In addition to paper or paperboard, the vacuum gripper is also suitable for handling sheet-like materials made of polymer, medium density fiberboard or any other flexible material.

The distance between adjacent gas flow openings or the grid size of the array may be chosen smaller compared to the geometric elements of the layout. Thus, small, elongated, or profiled layout geometry elements may also be reliably gripped by the vacuum gripper. More precisely, each geometric element is seized by a relatively large number of airflow openings. Additionally, the small mesh size may increase the vacuum force applied to an area of the sheet material. Thus, heavier or thicker sheet materials can be processed.

Preferably, an array of air flow openings covers a predetermined maximum format of sheet material to be handled by the vacuum gripper. Thus, by selectively closing and opening the airflow openings as described above, any kind of layout geometry can be separated from the remaining waste material as long as the outer boundary of the maximum format is met. The vacuum gripper is suitable for use with a variety of paperboard or paper products.

If the sheet material is provided in the form of a single sheet, the maximum format of the sheet material corresponds to the maximum format of the single sheet to be handled by the vacuum gripper.

According to an embodiment of the invention, an array of airflow openings is arranged at the clamping side of the clamp body, wherein the clamping side is provided with a hood that selectively covers the airflow openings associated with the scrap material and that selectively does not interfere with the airflow openings associated with the blank or blanks of the layout. This means that a cut-out area is provided in the cover which does not cover the airflow opening. The cut-out area substantially corresponds to the geometry of the one or more blanks of the layout. The remaining areas of the hood, i.e. the areas corresponding to the waste, are selectively covered, i.e. closed, with the respective airflow openings. In this context, "not disturb" means that the gripping function of the vacuum gripper is maintained with respect to these openings. Thus, the vacuum is applied only to the blank, not to the waste. Different masks may be provided for different geometries of the layout. Thus, in highly individualized production, a suitable cover is provided for each job. In preparing the holder for subsequent work, only the cover has to be replaced, which is preferably done without the use of tools. This process can be performed very quickly, thereby reducing setup and changeover times. The conveying unit does not need to be adjusted during replacement operation. It is generally applicable to all types of work that the gripper assembly is to handle.

The cover may be made of a sheet material, in particular a cardboard or a plastic material. Starting from a solid sheet, a laser cutter can be used to produce a cover suitable for a particular job. For this purpose, the laser cutter can be loaded manually or automatically. In a second embodiment, a gripper-mounted robot may pick sheets from a stack of unprocessed masks and place them in a cutting area.

It is thus possible to produce the cover and to process the sheet material with the same cutting machine, which then cooperates with the vacuum gripper equipped with this cover. Thus, no special machinery is required to produce the cover.

It is also possible to provide the hoods with a storage unit where each hood of different geometry is associated with a certain type of layout, where the hoods of different geometry can be stored when they are not used on the vacuum gripper.

To replace the cover of the vacuum gripper, the gripper can adopt a mounting position characterized by easy access for the operator. The operator can then manually replace the cover.

Advantageously, the clamping side of the vacuum clamp is magnetic, in particular wherein the magnetic cover is attached to the clamping side of the vacuum clamp. The magnetic cover may be magnetic sheet-like and does not interfere with any airflow openings. Thus, it does not interfere with the function of the vacuum gripper. The magnetic cover may be glued or attached to the clamping side of the clamp by any other suitable method. Such a holder provides the possibility of attaching the cover to the holder by magnetic means. This allows for easy and quick replacement of the cover.

In this case, the cover may be positioned between the magnetic side of the vacuum holder and a magnetic sheet covering the cover on its side opposite the vacuum holder. Thus, the cover is attached to the holder body in a reliable manner and at the same time is still easy to replace. Preferably, an aperture is provided in the magnetic sheet, the aperture being disposed opposite each of the airflow openings of the holder. Therefore, the function of the vacuum gripper is not hindered by the magnetic sheet. Advantageously, the cover is made of a non-magnetic material. As an alternative to the magnetic sheet, a magnetic grid may be provided, which grid covers the cover on the side thereof opposite the vacuum holder. In both alternatives, i.e. the magnetically attractable sheet and the magnetic grid, the cover can be manually replaced as above.

Alternatively, the cover may be replaced semi-automatically. In this case, the magnetic sheet is stored in a precise position, and the operator manually positions the cover on the holder to be attached to the magnetic sheet. After the previous cap is removed from the holder, it is automatically moved to a position vertically above the magnetic sheet, causing the later to be magnetically attracted to the holder. Then, the cover and the magnetic sheet are mounted to the holder.

The cover can also be replaced in a fully automatic manner. As a preparatory measure thereto, the operator removes the magnetic sheet and the existing cover from the holder. Subsequently, the new cover is gripped by a gripper using a vacuum gripper function. That is, the airflow inlet associated with the waste material serves to grasp the shroud and attach the shroud to the holder. The magnetic sheet is likewise stored in a precise location, and then the magnetic sheet is mounted to the holder by moving the holder to a position vertically above the magnetic sheet so that the latter is magnetically attracted to and held on the holder.

Whenever a new or different cover is mounted on the holder, it must be ensured that the cover is not contaminated, in particular from waste material resulting from the manufacturing process of the cover. Otherwise, small waste particles may get caught between the magnetic sheet and the vacuum holder to block the air flow opening in an undesirable and uncontrolled manner. This must be avoided.

The risk of contamination of the hood by waste particles is particularly high immediately after the cutting process, for example a laser cutting process, which cuts the hood according to the geometry of the layout to be recovered. To remove the waste particles from the hood, the waste particles can be separated from the hood by means of air jets. Alternatively, during cutting of the cover, the waste portion of the sheet material of the cutting cover may be cut into small pieces small enough to be drawn through the vacuum chamber of the vacuum gripper without jamming. In this case, there is no risk of hindering the gripper function. If the hood is cut on an uneven conveyor belt, these small waste particles can also fall through the conveyor belt or be sucked through the conveyor belt without getting stuck.

The transport unit may include a number of suction ports that are fluidly connected to a vacuum system such that drawing air through the suction ports by the vacuum system retains the sheet material on the transport unit. In particular the arrangement of the suction openings is independent of the size and/or shape of the sheet material to be processed. This also means that the configuration of the suction openings is independent of the size and/or shape, i.e. layout, of the one or more blanks. In other words, the conveying unit is generally applicable to any kind of sheet material including any kind of layout. Thus, the transport unit does not need any changes when the gripper assembly is adapted to a new job. Thus, the conversion time and the corresponding effort are reduced.

And, the vacuum system is configured such that a vacuum force applied to the one or more blanks by the vacuum system is less than a vacuum force applied to the one or more blanks by the vacuum gripper. The vacuum gripper is thus able to grip and move the blank held by the transport unit. In other words, the vacuum gripper is able to separate the blank from the transport unit.

Furthermore, this problem is solved by a device according to claim 8. For such a device, it is useful to explain the effects and advantages of the vacuum gripper. This means that such a device can provide short set-up times and short changeover times and is therefore very suitable for producing individualized paper or board products. Further, such an arrangement is independent of the number of blanks comprised by the layout, as a plurality of blanks may be gripped by the vacuum gripper. This results in a reduction in overall processing time and relatively low cost.

Since the gripper assembly according to the invention can be used for sheet material, which is supplied in the form of a single sheet or a roll, the device according to the invention can also be used in both forms.

In the context of such a device, it is preferably not necessary to connect the layout and the waste material by means of so-called break points, i.e. small bridge-like elements of the sheet material that physically connect the layout with the waste material. In other words, a break point is a small interruption on the cutting line to create a bridge between the layout and the scrap. Thus, during blanking, these split points do not need to be broken. This results in paper or paperboard products of high optical quality because they are free of small protuberances which are usually present at the end of the breaking point.

The use of such a device is particularly suitable when used in conjunction with a laser cutting machine. As described above, the laser cutting machine has an advantage of short setup time and switching time. The same is true for the device according to the invention. Thus, a substantially continuous production flow can be established using the laser cutting machine and the device according to the invention. This results in a high product yield per unit time, especially for so-called short run production.

The apparatus may comprise one or more additional vacuum grippers, wherein each additional vacuum gripper is connected to a respective additional handling unit. Thus, several vacuum grippers can be used in parallel in a recovery arrangement from the sheet material. Therefore, the blanking process can be performed at high speed. This results in high product yields per time unit. The number of vacuum grippers is generally not limited and can be selected on a case-by-case basis.

A plurality of vacuum grippers may cooperate with a single transport unit and a single sheet storage unit. In such a configuration, the vacuum grippers and the respective handling units may be arranged on opposite sides or on the same side of the transport unit, e.g. on the left and right sides of the conveyor belt. In doing so, a compact design of the device can be achieved.

According to a variant, at least one of the handling unit and the additional handling unit comprises an industrial robot adapted to handle the respective vacuum gripper within a predetermined range of motion. For example, a six-axis industrial robot arm or a two-axis pick-and-place robot may be used.

The conveyor unit may be directly connected to the product output area of the laser cutter such that the sheet material is placed on the conveyor unit without any detour. Furthermore, the handling unit and the one or more vacuum grippers may be adapted to cooperate with the moving transfer unit. Therefore, the sheet material is moved at a constant speed while the peeling process is performed. This results in a shorter overall processing time.

The blank storage unit may be a stacking unit. This means that blanks recovered from the sheet material are stacked on top of each other. In case the layout comprises more than one blank, the different blanks may be sorted such that blanks of the same geometry or type are stacked on top of each other.

Furthermore, the problem is solved by a method according to claim 12. Therefore, the blanking or peeling process can be performed in an easy and quick manner. This improves the profitability of such a process.

After step c), the blanks may be moved to a blank storage unit, in particular a stacking unit or a further transport unit. Effects and advantages have been described with reference to a blank storage unit.

As explained in the foregoing description of the gripper assembly and apparatus, the performance of the method can also be applied to sheet material provided in a single sheet or in roll form.

In addition to sheets made of paper or paperboard, the method according to the invention is also suitable for processing sheet material made of polymer, medium density fiberboard or any other flexible material.

In another form, a vacuum gripper is positioned on the sheet during step b), wherein the gripper selectively grasps the blank without cooperation with the waste material. Thereby enabling the vacuum gripper to grasp the blank in an accurate manner. Thus, the method is also applicable to layouts with very small or fine parts.

Drawings

The invention will now be explained with reference to a few embodiments shown in the drawings. In the drawings, there is shown in the drawings,

fig. 1 shows a schematic view of an apparatus for recovering a layout from a sheet material according to a first embodiment of the invention, wherein the sheet material is also shown.

Fig. 2 shows an exemplary sheet material, which can be processed in the device according to fig. 1,

figure 3 shows a schematic view of an apparatus for recovering a layout from a sheet material according to a second embodiment of the invention,

figure 4 shows the device according to figure 3 seen in the direction IV of figure 3,

fig. 5 shows a vacuum gripper of the gripper assembly according to the invention, simultaneously engaged with a sheet material,

FIG. 6 schematically illustrates the fit between the sheet material and the cover of the vacuum gripper and

figure 7 shows in an exploded view a vacuum gripper of a gripper assembly according to a second embodiment of the invention.

Detailed Description

In fig. 1, an apparatus 10 for recovering a layout from a sheet material 12 is shown. Which cooperates with a sheet material 12 made of paper or cardboard.

The sheet material 12 is provided on a conveyor unit 14, which in the example shown is a conveyor belt. The conveyor belt moves in the direction indicated by arrow 16.

The transport unit 14 is equipped with a vacuum system 15 for holding the sheet material 12 on the relevant surface of the transport unit 14.

To this end, the delivery unit 14 includes a number of suction ports 15a that are fluidly connected to the vacuum system 15 such that the sheet material 12 may be retained by drawing air through the suction ports 15a (only some of the suction ports 15a are designated with reference numerals for clarity).

Further, the apparatus 10 includes a layout storage unit 18 on which one or more blanks 20 of a layout 22 retrieved from the sheet material 12 may be positioned. In this example, the layout memory cell 18 is a so-called stack cell. This means that the blanks 20 of the layout 22 are stacked on top of each other in the layout memory unit 18.

Additionally, the device 10 has a handling unit 24, which is connected to a vacuum gripper 26. The handling unit 24 and the corresponding vacuum gripper 26 are shown in three different cases, designated A, B and C.

The handling unit 24, which is only schematically indicated, may comprise an industrial robot adapted to handle the respective vacuum gripper 26 within a predetermined range of motion.

The transport unit 14 and the vacuum gripper 26 constitute a gripper assembly 27.

The method of separating the layout 22 from the scrap material 28 of the sheet material 12 may be performed by the apparatus 10. In other words, a method of peeling or blanking is performed.

Fig. 2 shows an exemplary sheet material 12 comprising a layout 22 having four blanks 20 and a scrap material 28.

In a first step of the method, a sheet material 12 is provided.

The blank 20 of the layout 22 is then gripped with a vacuum gripper 26 (situation a in fig. 1). To do so, the vacuum gripper 26 is positioned on the sheet material 12 and grasps only the arrangement 22.

The vacuum gripper 26 does not engage the waste material 28.

The layout 22 is then separated from the scrap material 28, as shown in case B in fig. 1. In this example, the layout 22 is raised by the vacuum gripper 26, while the waste material 28 remains on the transport unit 14.

This is possible because the vacuum system 15 is configured such that the vacuum force applied to the layout 22 by the vacuum system 15 is less than the vacuum force applied to the layout 22 by the vacuum gripper 26.

Subsequently, the gripper 26 moves to the condition C where it is positioned on the blank storage unit 18. The blanks 20 are stacked on the blank storage unit 18 or on other blanks 20 already positioned. Thereafter, the engagement between the vacuum gripper 26 and the blank 20 is terminated, and the vacuum gripper 26 can be moved back to condition a by the handling unit 24.

Fig. 3 and 4 show a second embodiment of the device 10. This embodiment differs from the embodiment explained above in that it comprises an additional vacuum gripper 26a, which is connected to a corresponding additional handling unit 24 a.

The two vacuum grippers 26, 26a cooperate with a single transport unit 14 and a single layout storage unit 18.

The vacuum grippers 26, 26a can operate according to two variants. Either of the two vacuum grippers 26, 26a cooperates with a different portion of a single sheet of material 12 in the sense that the vacuum gripper 26 grasps a first portion of the layout and places it on the layout storage unit 18 and the additional vacuum gripper 26a grasps the remaining second portion of the layout and places it on the layout storage unit 18. Alternatively, each second sheet of material 12 provided by the delivery unit 14 may be processed by a vacuum gripper 26 and each other sheet of material 12 may be processed by an additional vacuum gripper 26 a.

In both variants, as shown in fig. 3, both vacuum grippers 26, 26a can operate along the same trajectory 30.

As for the method of implementing the layout for separating waste from sheet-like material using the second embodiment, the explanation similar to the above is applicable.

In fig. 5 to 7, the vacuum gripper 26 is shown in detail. An exemplary sheet of material 12 is also shown. Since the additional vacuum gripper 26a is the same, a detailed description thereof will be omitted.

The vacuum gripper 26 includes a gripper body 32. An array of airflow openings 34a, 34b are disposed on the clamping side thereof (only a portion of the airflow openings 34a, 34b are designated with reference numerals for clarity). Each of the airflow openings 34a, 34b is adapted to grasp at least a portion of the sheet material 12.

As can be seen from fig. 5 and 6, only the gas flow openings 34a associated with the layout 22 are open, i.e. only the gas flow openings 34a associated with one or more blanks 20 of the layout 22 are open. The remaining airflow openings 34b are closed because they are covered by the cover 36. Thus, the hood 36 does not interfere with the airflow openings 34a associated with the layout.

Thus, the vacuum gripper 26 adapts to the geometry of the layout 22 such that only the blank 20 is grasped when positioned over the sheet material 12. The waste material 28 is not caught by the vacuum gripper 26. Such a vacuum gripper 26 is therefore well suited to separate the arrangement 22 from the waste material 28.

As best shown in FIG. 6, an array of air flow openings 34a, 34b cover a predetermined maximum format of sheet material 12 to be manipulated by the vacuum gripper 26.

An array of airflow openings 34a, 34b is small in mesh compared to the geometry of the layout 22 to be recovered. Thus, the vacuum gripper is adaptable to a wide variety of different types of recovery arrangements 22 by adapting the hood 36 to the geometry of the arrangement 22.

Another embodiment of a vacuum gripper 26 is shown in fig. 7. In this embodiment, the vacuum gripper 26 is magnetic, more specifically a magnetic cover 38 is attached to the gripping side of the vacuum gripper 26, for example by gluing.

The shroud 36 is now positioned between the magnetic cover 38 and the magnetic sheet 40 and is thereby securely attached to the vacuum gripper 26.

The cover 36 is made of a non-magnetic material and can therefore be easily replaced by detaching the magnetic sheet 40 from the vacuum holder 26 and positioning a different cover 36 on the magnetic lid 38.

As can be seen, an array of holes is provided in both the magnetic cover 38 and the magnetic sheet 40. The arrays of apertures correspond to an array of airflow openings 34a, 34 b. Therefore, neither the magnetic cover 38 nor the magnetic sheet 40 can block or obstruct the airflow openings 34a, 34 b. Thus, there is no need to replace or fit the magnetic cover 38 and magnetic sheet 40 when adapting the vacuum gripper 26 to different geometries of the layout 22.

Apart from these structural differences, the function of the vacuum gripper 26 according to the second embodiment is not different from the vacuum gripper 26 explained with reference to fig. 5 and 6.