EP3095597B1 - Device for folding carton blanks - Google Patents

Description

The present invention relates to a folding hook and a device for folding cardboard blanks, which is for example in a folding box gluer.

Folding cartons are cut-to-size prefabricated boxes, which are delivered in a collapsed state by the manufacturer to processing companies to save space. There, the carton blanks are unfolded into the carton with simple hand movements or by machine. The carton blanks are usually made of cardboard, preferably made of corrugated cardboard.

Some carton blanks include tabs that are folded by about 180 ° at the manufacturer. Most of these folded tabs are then glued to an adjacent part of the carton blank. These processes take place in folding box gluing machines. For this purpose, the area-trained carton blanks are conveyed in the transport direction by the gluing machine and processed during the process.

For folding over the tabs on a front in the transport direction edge of the carton blank rotating devices are known, which are referred to as Vorderfalthaken.

For folding over the tabs on a rear edge in the transport direction of the carton blank rotating devices are known, which are referred to as Hinterfalthaken.

Front catch and Hinterfalthaken are arranged in conventional machines each on a separate shaft, each having a separate drive (servo motor), which is controlled separately by a higher-level machine control.

From the US 4,544,368 a folding box gluing machine is known, wherein the front in the transport direction Flaps are folded. For this purpose, the Faltschachtelklebemaschine has a device for folding the front flaps upwards, which comprises hook-shaped, pivotable elements. The folding of the transport direction in the direction of transport in the rear edge of the carton blank is not described in this document.

From the US 2011/0092350 A1 a device for folding folding carton blanks is known, which has Vorderfalthaken and sickle-shaped Hinterfalthaken. At all sickle-shaped Hinterfalthaken each Vorderfalthaken is arranged in close proximity to a drive shaft.

From the DE 1 956 268 A a device for folding folding carton blanks with a folding disc is known. At this folding disk spaced apart a Aufrichtklappe and a folding flap are arranged, which take over the functions of a Vorderfalthakens and a Hinterfalthakens.

From the DE 1 561 432 A1 is a folding device for the rear lying in the transport direction flaps of cartons known.

From the US 1 513 297 A is a folding hook known, which is used for folding paper bags.

Object of the present invention is to simplify the folding of front and rear flaps and to provide a particularly compact and inexpensive device.

This object is achieved by a folding hook with the features of claim 1.

In the region of the convexly curved projection, the folding hook has a thickness D ₁₆ which is greater than in the crescent-shaped region (D ₁₆ > D ₂₀ ). Therefore, the convexly curved projection of the folding hook according to the invention projects beyond the contour of a conventional rear folding hook on a side opposite the crescent-shaped and concave area.

This means that the folding hook according to the invention can serve alternately as Vorderfalthaken and as Hinterfalthaken. The folding hook according to the invention first raises the tab on the front edge and then unfolds the flap located on the trailing edge.

The folding hook according to the invention takes over successively two functions and is therefore also referred to in the context of the invention as a combination folding hook.

As a result, only one shaft and one drive are required for the combination folding hook according to the invention in order to fold tabs on the leading edge and on the trailing edge of a carton blank during a passage through the device according to the invention. This significantly reduces the manufacturing costs and space requirements of the device according to the invention.

Preferably, the folding hook according to the invention is arranged on a rotating drive shaft. A plurality of such combination folding hooks can be arranged at different positions in the processing line of the folding box gluing machine in order to successively be able to fold different flaps which are arranged next to one another at the front and rear edges.

In a preferred embodiment it is provided that at least two, preferably three folding hooks are arranged at a same angular distance as a folding hook arrangement on a drive shaft. The arrangement of three folding hooks thus resembles a Triskele. When several combination folding hooks according to the invention are arranged around a drive shaft, the performance of the device according to the invention increases, at almost the same cost.

For faster processing of cardboard cuts in the folding box gluing machine, several triskels can be arranged in different positions in the folding box gluing machine.

It is further provided that the drive shaft is controlled in dependence on the transport speed and / or the position of the carton blank. This ensures that the convexly curved projection and the substantially crescent-shaped shape of the folding hooks engage in each case at the right time at a front and a rear flap of the carton blank.

In addition, it is provided that the drive shaft rotates stepwise and / or with different rotational speed. Assuming that the transport speed of the carton blank is done at a uniform speed, it may be necessary for effectively folding the tab that the drive shaft in certain periods of time, the folding hooks or only slowly move, or at certain times the folding hooks for a short time especially to move fast.

The drive shaft does not run at a constant speed.

In order to be able to control the rotational movement of the drive shaft, the device according to the invention can have scanning devices for the carton blank and / or suitable sensors which determine the respective current position of the tab to be folded over. The signals of the scanning devices or sensors are evaluated in a control device and, depending on the result determined, the drive shaft is rotated by its drive.

Further advantages will become apparent from the following description and the accompanying drawings.

Figur 1

zwei um 180° versetzt zueinander auf einer Antriebswelle angeordnete Vorderfalthaken (Stand der Technik);

Figur 2

zwei um 180° versetzt zueinander auf einer Antriebswelle angeordnete Hinterfalthaken (Stand der Technik);

Figur 3

einen erfindungsgemäßen (Kombinations-)Falthaken in einer bevorzugten Ausführungsform;

Figur 4

eine Bearbeitungsstraße einer Faltschachtelklebemaschine in einer Draufsicht;

Figur 5

acht Arbeitsschritte (Fig. 5a - 5h) des Falthakens aus Fig. 3 beim Umklappen von Laschen eines Kartonzuschnitts und

Figur 6

eine nicht erfindungsgemäße Kombination eines Vorderfalthakens und eines Hinterfalthakens.

Embodiments of the invention are illustrated in the figures and are explained in more detail in the following description. In each case, in schematic form:

FIG. 1

two offset by 180 ° to each other on a drive shaft arranged Vorderfalthaken (prior art);

FIG. 2

two offset by 180 ° to each other on a drive shaft arranged Hinterfalthaken (prior art);

FIG. 3

a (combination) folding hook according to the invention in a preferred embodiment;

FIG. 4

a processing line of a Faltschachtelklebemaschine in a plan view;

FIG. 5

eight steps ( Fig. 5a - 5h ) of the folding hook Fig. 3 when folding flaps of a carton blank and

FIG. 6

a non-inventive combination of a Vorderfalthakens and a Hinterfalthakens.

Description of the embodiments FIG. 1 shows a Vorderfalthaken 10 of the prior art. In FIG. 1 are two Vorderfalthaken 10 offset by 180 ° to a common drive shaft 12 arranged with hexagonal cross-section. The two Vorderfalthaken 10 are connected to each other by a chain link 14 and fixed by means of a clamping screw 15 to the drive shaft 12.

At the free end of the Vorderfalthakens 10 each have a convexly curved projection 16 is formed in FIG. 1 is formed annular. By a rotation of the drive shaft, the convexly curved projection 16 is usually pressed from below against a arranged at the front edge of a carton blank tab. As a result, the tab is raised and moves against a fixed "obstacle", which causes the actual folding of this tab. The transport movement of the carton blank supports or allows the folding of this tab only.

Even if at the rear of the carton blank (seen in the direction of transport) a tab is present, the is also to be folded, a separate Hinterfalthaken 18 is required according to the prior art.

FIG. 2 shows two oppositely arranged Hinterfalthaken 18 according to the prior art.

The Hinterfalthaken 18 is bent on its inside at least partially sickle-shaped. The Hinterfalthaken 18 folds with its rounded tip 21 a at a trailing edge of a carton blank (not shown) tab. The crescent-shaped region 20 is designed or curved so that the Hinterfalthaken 18 touches the tab only with its tip 21. This prevents the Hinterfalthaken 18 damaged the tab when folding.

The tip 21 is thus the actual effective range of the Hinterfalthakens 18, which at least partially rotated under a from the rear of the carton blank (seen in the transport direction) cut tab of a carton blank and then folds the tab by a further rotational movement of the Hinterfalthakens 18 about the drive shaft 12 ,

In this case, the rotational movement of the drive axle 12 must be controlled so that the tip 21 of the Hinterfalthakens 18 at least briefly "overhauled" the rear end of the carton blank in the transport direction.

FIG. 3 shows three folding hooks 22 according to the invention, which are arranged offset by 120 ° to each other on a drive shaft 12. This arrangement is reminiscent of a so-called Triskele and is a preferred arrangement 23.

The combination folding hooks 22 according to the invention have features of a front folding hook 10 and a back folding hook 18 of the prior art. Thus, a convexly curved projection 16 is formed at the free ends of the folding hook 22, wherein the folding hook on the convexly curved projection 16 has a thickness D ₁₆ which is greater than a thickness D ₂₀ in the crescent-shaped area 20. To save weight , the convexly curved projection 16, as well as in FIG. 1 , be formed annular. The projection 16 serves to realize the Vorderfalthakenfunktion.

In other words, at its free end and on a concavely curved side of the crescent-shaped region 20, the folding hook 22 according to the invention has a projection.

In addition, the folding hooks 22 in their course, in particular on the inside of the folding hook 22, a crescent-shaped portion 20 on. The area 20 serves to realize the Hinterfalthakenfunktion.

The tip 21 is formed only on the inside of the folding hook 22, that is, in continuation of the crescent-shaped portion 20. On the outside, where the convexly curved projection 16 is present, no pronounced tip is present and, moreover, not required. The folding hook 22 according to the invention thus represents a Kombinationsfalthaken, which combines the functions of a Vorderfalthakens and a Hinterfalthakens.

FIG. 4 shows a part of a processing line in a plan view. Shown is a folding or folding module 24 (hereinafter referred to as "module") are recessed in the conveyor belt 26 in grooves. The transport belts 26 serve to convey a carton blank 28 through the module 24. The transport direction (feed direction) is indicated by an arrow with the reference numeral 30. In order to be able to transport the carton blank 28 even when the side walls are folded over, the transport belts 26 are arranged offset to one another in part. Preferably, the transport belts 26 in the module 24 are laterally displaceable (see reference numeral 32) in order to adjust the module to the processing of different large carton blanks. The module 24 is adapted to automatically fold on two sides of a carton blank 28 tabs 34, 34 'at the front edge and the trailing edge of the carton blank. A fold line for the carton blank 28 is identified by the reference numeral 36.

In the module 24, as seen in the transport direction 30, at two different positions 38, 38 'folding hooks 22 are arranged, wherein the folding hooks 22 at the position 38 of the folding over outer tabs 34, 34 'of the carton blank 28 is used. In the position 38 ', the folding hooks 22 are arranged for folding over tabs arranged in the interior of the carton blank.

In the positions 38, 38 'is in FIG. 4 essentially the drive shaft 12 is shown with the folding hooks 22.

The function and operation of the folding hook assembly 23 with three folding hooks 22 according to the invention (according to FIG FIG. 3 ), as it could be arranged, for example. At the position 38 in the Faltschachtelklebemaschine, will be described below with the help of FIGS. 5a to 5h described. In these figures, only the part of the module 24 necessary for understanding and the carton blank 28 moving through the module 24 (in different positions) are shown.

FIG. 5a shows circulating the transport belt 26. On the transport belt 26 is a flat trained cardboard blank 28 is placed, which is moved by the transport belt 26 in the transport direction 30.

The carton blank 28 has notches 42. Through these cuts 42, the folding tabs 34, 34 'are "divided". In addition, the carton blank 28 has bent edges 44. Along these kink edges 44, the tabs 34, 34 'folded.

The folding hook arrangement 23 is arranged on a rotating drive shaft 12. A direction of rotation of the drive shaft 12 is designated by the reference numeral 40.

By a suitable control of the drive shaft 12, one of the folding hooks 22 touches the tab 34 located at the front edge of the carton blank from below.

In FIG. 5b the carton blank 28 has moved on and the drive shaft 12 has rotated so far in the direction of rotation 40 that the convexly curved projection 16 at the free end of the folding hook 22 raises the front tab 34. As a result, the tab 34 bends so far at the bend edge 44 that the tab 34 strikes a fixed fold-over roll 46 disposed above the carton blank 28 when the carton blank 28 is further transported through the module 24. The Umklapprolle 46 then takes over the actual folding of the tab 34. Under folding it is a bend of the tabs 34, 34 'by significantly more than 90 °, preferably by about 180 °, understood. This process is in the FIG. 5c illustrated. Alternatively to the Umklapprolle can also be used a brush or a hold-down rod.

In FIG. 5c the drive shaft 12 has been rotated in the direction of rotation 40 so far that none of the folding hooks 22 touches the tab 34. The Umklapprolle 46 is further in contact with the tab 34. By the (further) feed of the carton blank 28 in the transport direction 30, the folding roller 46 presses the tab 34 further back and down.

FIG. 5d shows the completely folded flap 34. The carton blank 28 has now been moved so far in the transport direction 30 that the folding hooks 22, the tab 34 can not reach. The drive shaft 12 is temporarily stopped or rotates only very slowly. The transport of the carton blank 28 continues in the transport direction 30.

In FIG. 5e the tip 21 of a folding hook 22 concealed by the tab 34 'has reached the rear flap 34' of the cardboard blank 28. As a result of the rotational movement of the drive shaft 12 in the direction of rotation 40, which begins again, the tip 21 of the folding hook 22 raises the rear tab 34 ', as a result of which the tab 34' kinks around the bending edge 44.

In order to further fold over the tab 34 ', the drive shaft 12 must briefly perform a relatively fast rotational movement, so that the tip 21 of the folding hook 22' overtakes 'the moving carton blank 28 and as a result the tab 34' is folded forwards. This situation is in the FIG. 5f shown.

In FIG. 5g the rotational movement of the folding hook assembly 23 is almost complete. Due to the sickle-shaped formation 20 of the folding hook 22 prevents the folding hook 22 the Umklappbewegung the rear tab 34 'bothers, or that the folding hook 22, the tab 34' is not damaged.

In FIG. 5h the folding of the front flap 34 and the folding of the rear flap 34 'is completed. The rotational movement of the folding hook arrangement 23 can be interrupted until a further carton blank 28 is brought onto the transport belt 26 in the region of the folding hook arrangement 23.

In the FIG. 6 an arrangement of a Vorderfalthaken 10 and a Hinterfalthaken 20 on a common drive shaft 12 is shown. In this arrangement, which is not the subject of the present invention, the known from the prior art folding hooks 10, 20 are successively used. This means that a significant advantage of the invention, namely the need to provide only one drive shaft 12, is also achieved by this arrangement. As a result, the cost advantage and the saving of footprint are achieved.

The control of the drive shaft 12 is in this arrangement over the embodiment of the invention according to the FIGS. 5a to h something else. The performance [carton blanks / min] of both arrangements is similar.

Characterized in that both folding hooks are arranged on a common shaft, Savings in installation space, reduction of the number of shafts and drives with the same functionality are achieved. The front latch and the rear latch are designed as separate components. As a result, inter alia, the conversion of existing devices for folding flaps of a carton blank comprising a transport device of cardboard blanks is facilitated. Also, the control of the common drive shaft can build on existing controls of front latch and the Hinterfalthaken (on separate drive shafts). This considerably simplifies and simplifies the integration into the machine control.

The working method corresponds largely to that in connection with the FIGS. 5a to 5h explained method of operation, so reference is made in this regard to these figures and their description.

Claims (6)

1. Folding hook (22) for folding down tabs (34, 34') of a planar carton blank (28), the tabs (34, 34') being arranged on an edge of the carton blank (28) that is at the front in the transport direction and/or on an edge of the carton blank that at the rear in the transport direction, characterized in that the folding hook (22) comprises a convexly curved projection (16) on a free end, in that the folding hook (22) is substantially crescent-shaped and concave in a region (20) opposite the convexly curved projection (16), and in that a tip (21) is formed on the folding hook (22) as a continuation of the crescent-shaped region (20).
2. Folding hook arrangement comprising two or three folding hooks (22) according to claim 1, wherein the folding hooks (22) are arranged on a common drive shaft (12).
3. Device for folding down tabs (34, 34') of a carton blank (28), comprising a transport apparatus for transporting a carton blank (28) and means for folding down a tab (34) on a front edge of a carton blank (28) and means for folding down a tab (34') on a rear edge of a carton blank (28), characterized in that at least one folding hook (22) according to claim 1 or a folding hook arrangement (23) according to claim 2 is arranged on a drive shaft (12).
4. Device according to claim 3, characterized in that two or more folding hooks (22, 10, 20) are arranged on the drive shaft (12).
5. Device according to any of claims 3 to 4, characterized in that a rotation of the drive shaft (12) depends on the transport speed and/or the position of the carton blank (28).
6. Device according to claim 5, characterized in that the drive shaft (12) rotates in steps and/or at different rotational speeds.

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