EP1470909B1 - Folding apparatus and method for setting-up a tray - Google Patents

Description

Technical area

The present invention relates to methods of forming a carton from a pre-grooved carton blank. Furthermore, the present invention relates to a device for carrying out this method with a die, which defines an opening, and a stamp, which is at least partially insertable into the opening.

State of the art

Methods and apparatus for forming cartons, such as those used for packaging plate-shaped workpieces such as furniture fronts, panels, strips or the like, are known in a variety of designs.

In this case, as a starting material usually flat cardboard blanks are used, which are usually equipped with pre-scored folding edges and, for example, consist of solid or Mehrfachwellpappe.

So revealed the DE 196 36 262 A a folding machine, in which the folding process of the carton blanks takes place with a plurality of mechanically operated flaps, which are displaceable in a common receiving plane, wherein the carton blank held during folding by a fixing device in the receiving plane. This solution has proven to be quite suitable, but has the disadvantage that the multiple mechanically operated flaps bring a comparatively complex design and control with him and are not suitable for a continuous folding process in continuous processing.

Another type of folding devices are those that operate on the Matritzen- or thermoforming principle. Thus, the applicant has been using folding devices for some time, which have a die which defines an opening and a die which is at least partially insertable into the opening. In addition to the punch and die, the known folding devices have tiltable or pivotable folding elements in order to fold inner straps, which can not be brought into their folded position by means of the punch stroke, by means of a tilting movement.

However, these folding elements have the disadvantage that they lead to a complex construction and control of the folding device and a correspondingly complicated procedure to allow precisely defined tilting or pivoting movements. In addition, the adaptation of the tiltable or pivotable folding elements to changing geometries of cardboard blanks is difficult.

DE 1 086 533 B . DE 1152007 B and US 4988331A reveal more folding devices.

Presentation of the invention

It is an object of the present invention to provide a simplified method of forming a carton from a pre-grooved carton blank.

This object is achieved according to the present invention by a method of forming a carton from a pre-grooved carton blank having the features of claim 1.

Preferred embodiments of the invention are specified in the dependent claims.

The present invention is based on the idea of concentrating the formation of a folded box from a pre-scored carton blank as far as possible on functions of the punch in order to simplify the procedure as well as the required apparatus for carrying out the method. For this purpose, the invention provides that the stamp takes on tasks that are performed in the prior art of additional folding elements. More specifically, it is provided in the method according to the invention that the stamp having two printing elements is withdrawn after a first insertion into the opening of a die to adjust the spacing of the printing elements in at least one direction and then a second insertion of the stamp in the opening of the die be made such that the carton blank is folded at least in sections.

In this way, with the method according to the invention, several successive folding operations can be carried out in a simple and rapid manner in order to produce a finished folding box from a pre-grooved cardboard blank. At the same time, the method according to the invention makes it possible to use a simplified folding device, which is described below.

According to a development of the method according to the invention, the spacing of the printing elements after the second insertion is adjusted at least in one direction, in order thereby to effect a folding process. The punch thus has a double folding function, namely on the one hand during its insertion into the opening of the die and on the other hand by means of adjusting its own dimensions whereby a wide variety of folding operations can be made on the pre-grooved carton blank. It is particularly preferred that the distance of the printing elements after the second insertion is increased. As a result, portions or tabs of the carton blank that are prefolded during the second insertion of the punch, can be brought in a simple and timely manner in its final folded position.

In order to ensure an optimal folding process during the second insertion of the punch into the opening of the die, according to a development of the method according to the invention, after the withdrawal and before the second insertion of the punch, tabs of the carton blank are folded or prefolded such that they interpose the opening of the die and the stamp come to rest. This makes it possible that the stamp can optimally absorb and fold the respective tabs at its second insertion, without jamming of the tabs or damage to the carton blank occurs.

In order to achieve an optimal implementation of the method according to the invention, the use of a folding device with the features of claim 4 is preferred according to the present invention. This is characterized in that the stamp has at least two printing elements, the distance is adjustable, and in particular also while the stamp is at least partially inserted into the opening of the die. With this construction, the stamp is given a simple, but variable construction, whereby the printing elements can easily be matched in their geometry to the desired folding functions. In this context, it is further provided that the at least two pressure elements are movable relative to one another in at least one direction, in particular also while the punch is at least partially inserted into the opening of the die.

According to one embodiment of the invention, the punch and preferably also the opening of the die dimensions, which are adjustable at least in one direction. As a result, a device with a simple construction is provided with which the method according to the invention can be advantageously carried out. In particular, no additional folding elements or only comparatively simple, additional folding elements are required in the device according to the invention, which considerably simplifies not only the construction but also the control of the device.

According to a development of the folding device according to the invention, the die is formed by at least two frame elements, which are connected to each other by means of adjusting elements, in particular sliding pieces, such that the dimensions of the opening of the die are adjustable. As a result, the variability of the folding device according to the invention is further increased by the folding device is easily adaptable to changing geometries of the carton blank or the carton to be formed. Furthermore, it is therefore conceivable to vary the dimensions of the die opening during operation of the folding device, for example to assist folding operations.

This concept can be realized particularly advantageous in that the die is formed by at least four rod-shaped frame elements which define the opening of the die and are connected to each other by means of adjusting elements, in particular sliding pieces, such that the dimensions of the opening of the die are adjustable. This modular design has proven to be very flexible and at the same time cost effective in practice.

In order to enable a first folding process already during the insertion of the carton blank between the opening of the die and the punch, it is provided according to a development of the folding device according to the invention that the adjusting elements with respect to the opening of the die in the direction protrude the punch and preferably have a wedge-shaped section. This makes it possible to put the pre-grooved cardboard blank between the punch and die opening, for example by means of a gripping device, that when inserting the carton blank already some tabs of the same are prefolded by the wedge-shaped section. In this way, the number of possible folding operations is further increased by means of a simple static component, without making the construction and control of the device more complex.

Nevertheless, in the case of complex carton blanks or folding cartons, it may be necessary to pre-fold individual tabs of the carton blank in the course of the overall process such that they come to rest between the punch and die opening, in order subsequently to be folded by a stroke movement of the stamp. For this purpose, it is preferred according to a development of the folding device according to the invention that it has a pre-folding, which is linearly movable and by means of the individual tabs of the cardboard section are foldable so that they come to rest between the punch and the remaining carton blank. In contrast to the prior art, it is sufficient in the context of the present invention that the pre-folding device is only linearly movable, and not necessarily tiltable, which keeps the construction and control of the device simple.

With regard to a reliable and permanent folding process, it is further provided according to a development of the present invention that the folding device has a counter-pressure device which is arranged on the side of the die opposite the punch. As a result, a dimensionally stable folding box can be formed by an interaction of punch and counter-pressure device.

Brief description of the drawings

Fig. 1

schematically shows a preferred embodiment of the folding device according to the invention and essential steps in carrying out the method according to the invention;

Fig. 2

schematically shows essential process steps in forming a carton from a grooved carton blank according to the inventive method.

Detailed description of a preferred embodiment

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

Fig. 1 schematically shows a folding device 1 for forming a folding box 2 'from a pre-grooved carton blank 2. The folding device 1 comprises a die 4, which defines an opening 6, and a punch 8, which is at least partially insertable into the opening 6. The punch 8 has in the present embodiment, two pressure elements 10, 12, whose mutual distance in the direction of the in Fig. 1d ) shown arrow 6, wherein the entire punch in the direction of in Fig. 1d ) shown arrow 5 is movable.

The die 4 is formed in the present embodiment by four rod-shaped frame members 14, 16, 18, 20, wherein the frame member 20 in Fig. 1 is covered by the frame member 18. The frame members 14, 16, 18, 20 define the opening 6 of the die 4 and are interconnected by means of sliding pieces 22 such that the dimensions of the opening 6 of the die 4 are adjustable. The adjustment of the frame members 14, 16, 18, 20 can be done manually by means Spindles etc. or automated by means of actuators etc.

Moreover, in the present embodiment, the sliding pieces 22 are formed so as to protrude from the opening 6 of the die 4 in the direction of the punch 8, a wedge-shaped portion 22 'being provided in the region of the projection.

Furthermore, the folding device 1 comprises a pre-folding device 24, which is linear along the in Fig. 1c ) shown arrows 4 is movable and is formed for example by movable angle pieces or the like. Finally, the folding device 1 comprises a counter-pressure device in the form of abutments 26, which are arranged on the opposite side of the punch 8 of the die 4.

The operation of the folding device 1 according to the invention and the method according to the invention for forming a folding box 2 'from a pre-grooved cardboard blank 2 will be described below with reference to FIG Figures 1 and 2 described, wherein Fig. 2 in each case individual states of the carton blank before or after execution of in Fig. 1 shows shown process steps.

First, the in Fig. 2a ) cardboard box 2 detected by means of a gripping device such as a gripper arm with vacuum suction and inserted into the folding device 1 such that the carton blank 2 between the punch 8 and the die opening 6 comes to rest ( Fig. 1a )). In this case, the carton blank 2 is inserted between the wedge-shaped portions 22 'of the sliding pieces 22 such that the tabs 2A through the wedge-shaped portions 22' as indicated by arrows in Fig. 1a ) are suggested to be folded. In this way, the in Fig. 2b ) state of the carton blank 2.

Subsequently, as in Fig. 1b ), the punch 8 is moved or inserted into the opening 6 of the die 4 such that the side flaps 2B, 2C of the carton blank 2 are folded. In this case, the carton blank 2 is pressed into the die opening 6 and the carton blank 2 reaches the in Fig. 2c ) state shown. Thereafter, the punch 8 is retracted to its original position.

As in Fig. 2c ), are end portions of the tabs 2C in this state, even beyond the side flaps 2B and are intended to be folded in the further process in the interior of the carton to be formed. To prepare for this folding, is now by means of the pre-folding 24 of in Fig. 1c ), wherein the angle-like elements of the pre-folding device 24 move linearly in the direction indicated by the arrows 4 and in this way the end portions of the flaps 2 C in the in Fig. 2d ) fold shown position. Thereafter, the elements of the pre-folding device 24 are withdrawn.

Finally, the folding of the end portions of the tabs 2C inward to the in Fig. 2e ) finished folding box 2 'finish. For this purpose, first the dimensions of the punch 8 in the direction of in Fig. 1d ) is reduced by the shoes 10, 12 are driven towards each other. It should be noted that the dimensions of the punch 8 in the previously described method steps substantially correspond to the dimensions of the base of the carton blank 2. From this condition, the dimensions of the punch in the direction of the arrow 6 are now reduced to allow folding in of the end portions of the tabs 2C.

After reducing the dimensions of the punch 8, it is again inserted into the opening 6 of the die 4 so that the end portions of the flaps 2C are folded inwardly.

With this method step, the forming of the folding box 2 'can already be completed. However, it is preferred that this is followed by a further method step, in which the dimensions of the punch 8 are again increased in the direction of the arrow 6, thereby causing an even further folding of the end portions of the flaps 2C. This method step is particularly preferred when the end portions of the flaps 2C are provided with locking projections 2D which serve to engage in recesses 2E of the carton blank 2, which gives the resulting cardboard box 2 'a higher stability. The enlargement of the dimensions of the punch 8 can in turn be achieved by moving the punch shoes 18, 12 in this final process step, which ensures a secure engagement of the projections 2D in the recesses 2E.

Thereafter, the finished carton 2 'removed from the folding device 1 or by means of a suitable device, such as a conveyor belt or the like, are discharged from the folding device 1.

Claims (11)

1. Process for forming a folded packet (2') from a pre-grooved carton blank (2) having the steps:

   placing the carton blank (2) between the opening (6) of a female mould (4) and a punch (8), which can be introduced at least in sections into the opening (6), and which has at least two pressure elements (10, 12), the distance of which can be adjusted at least in one direction,

   first introduction of the pressure elements (10, 12) into the opening (6) of the female mould (4) such that the carton blank (2) is folded at least in sections by the pressure elements,

   withdrawal of the pressure elements (10, 12) and adjustment of the distance of the pressure elements (10, 12) at least in one direction, and

   second introduction of the pressure elements (10, 12) into the opening (6) of the female mould (4) such that the carton blank (2) is folded at least in sections by the pressure elements.
2. Process according to claim 1, characterised in that after the second introduction of the pressure elements (10, 12), the distance thereof is adjusted at least in one direction, in particular increased, particularly to thus effect a folding process.
3. Process according to claim 1 or 2, characterised in that after withdrawal and before the second introduction of the pressure elements (10, 12), flaps of the carton blank (2) are folded such that they come to rest between the opening (6) of the female mould (4) and the punch (8).
4. Folding device (1) for carrying out the process according to one of the preceding claims, having:

   a female mould (4), which defines an opening (6),

   a punch (8), which has at least two pressure elements (10, 12), the distance of which can be adjusted, and can be introduced at least in sections into the opening (6),

   wherein the at least two pressure elements (10, 12) can be moved linearly with respect to one another in at least one direction.
5. Folding device according to claim 4, characterised in that the opening (6) of the female mould (4) has dimensions which can be adjusted at least in one direction.
6. Folding device according to claim 4 or 5, characterised in that the distance of the pressure elements (10, 12) can be adjusted even while the punch (8) is introduced at least in sections into the opening (6) of the female mould (4).
7. Folding device according to one of claims 4 to 6, characterised in that the female mould (4) is formed by at least two frame elements (14, 16, 18, 20), which are connected to one another by means of adjusting elements (22), in particular sliding pieces, such that the dimensions of the opening (6) of the female mould (4) can be adjusted.
8. Folding device according to one of claims 4 to 7, characterised in that the female mould (4) is formed by at least four rod-like frame elements (14, 16, 18, 20), which define the opening (6) of the female mould (4) and are connected to one another by means of adjusting elements (22), in particular sliding pieces, such that the dimensions of the opening (6) of the female mould (4) can be adjusted.
9. Folding device according to claim 7 or 8, characterised in that the adjusting elements (22) project opposite the opening (6) of the female mould (4) in the direction of the punch (8) and preferably have a wedge-shaped section (22').
10. Folding device according to one of the preceding claims 4 to 9, characterised in that it has a pre-folding device (24) which can be moved linearly and by means of which individual flaps of the carton blank (2) can be folded such that they come to rest between the punch (8) and the remaining carton blank.
11. Folding device according to one of the preceding claims 4 to 10, characterised in that it has a counter-pressure device (26), which is arranged on the side of the female mould (4) opposite the punch (8).

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