EP0894721B1 - Method and device for tying single objects or stacks of objects - Google Patents

Description

The invention lies in the field of packaging technology and relates to a method and a device according to the preambles of the corresponding independent claims. The method and the device serve for strapping substantially cuboid objects or stacks of objects, such as stacks of newspapers or magazines, which are successively conveyed into a strapping position and after strapping out of it.

According to the prior art, objects or stacks of objects which are conveyed on a conveying path are strapped transversely to this conveying direction with the aid of a band channel which extends in a loop around the conveying path and in the region of which the object to be strapped is stopped. A band loop positioned in the band channel is then pulled out of the band channel, stretched around the object and closed, for example, by welding around the object.

Corresponding band channels can also be used for strapping parallel to the direction of conveyance if it is ensured that the band channel is used for conveying away of the strapped object. This is realized, for example, by designing the belt channel or parts thereof to be movable in such a way that they can be removed from the conveyor path before the strapped object is conveyed away (for example DE-4421661), or by using belt channel parts that could hinder further conveyance on the side of the conveyor path be arranged and the band is only moved into the area of the conveyor track when it is pulled out of the band channel (DE-4230730).

According to the prior art, objects are also strapped in two directions that are essentially perpendicular to one another, in that a plurality of devices, as briefly described above, are sequentially arranged one behind the other or integrated into one another. Simple arrangements have two transverse strapping devices arranged sequentially one behind the other, the conveying direction of the objects to be strapped between the two devices being changed by 90 ° or the objects to be strapped being rotated by 90 °.

Devices for simultaneous longitudinal and transverse strapping with the aid of band channels are described, for example, in the publications DE-3909223 and US-5078057. These devices are complex both in terms of mechanics and in terms of control. Furthermore, the methods with band channels, in particular for longitudinal strapping, are limited to narrow strapping material, i.e. they can only be used for strapping, but not for wrapping with a wider material, and the band channels are simple in terms of device only if strapping material is used which is sufficient Stability in order to be able to be pushed into the channel.

This also applies to the relatively simple device with two band channels (DE-3303956) arranged obliquely to the conveying direction in the area of a strapping position, in the effective area of which the objects or stacks to be strapped must be conveyed with their diagonals parallel to the conveying direction.

Methods for strapping parallel to the conveying path (longitudinal strapping) are also known in which the strapping material (e.g. band) is fed in from two sides opposite one another relative to the conveying path (top / bottom, left / right). The ends of the strips fed from one side are connected to each other so that the strip is stretched like a curtain across the conveying path of the object or stack to be strapped. The object or stack is moved on the conveyor path against the belt stretched over the conveyor path, so that it lies on its front side and is pulled along. When the back of the object to be strapped has passed through the place of the band curtain, the two bands on the back of the object or stack are reconnected and cut off in such a way that the two separated pieces of band are closed around the object parallel to the direction of conveyance, and for the following article the belt is in turn stretched through the conveyor path.

Devices for carrying out this type of longitudinal strapping are described, for example, in the publications EP-225665, EP-592049, DE-2548786 or DE-2513668. The same publications also describe devices for connecting and disconnecting the tapes from the two tape sources.

Devices in which the strapping material is fed from only one side and in which the free end of the band works also work on the same principle with the help of a movable gripper or a similar mechanical means stretched through the conveyor path and closed around the object to be strapped.

The strapping using a strapping material stretched through the conveying path, like the methods described above with a band channel, can be used for relatively narrow and relatively stiff strapping bands. However, it is also easily adaptable for the use of wider strapping materials and for the use of strapping materials which have no or only very little inherent rigidity. Objects and stacks of objects can also be wrapped with these last-mentioned methods, for example with thin foils made of plastic, which have essentially the same width as the objects to be strapped or are wider than these, "strapped" or rather.

Publication EP-113874 also describes a combination of transverse strapping with the longitudinal strapping described above. In this combination, however, only strapping without significant tension, as is customary for strapping in the sense of wrapping with foils, is possible at least in the longitudinal direction.

The object of the invention is to provide a method for strapping substantially cuboid objects or stacks which are fed one behind the other. With the method according to the invention, it should be possible to create stable strapping with a simple device and largely independently of the strapping material (different widths, different requirements for the tension required for the strapping). In addition, the method should allow a high degree of flexibility regarding the type of strapping (longitudinal strapping, cross strapping, cross strapping), the cycle time should be essentially independent of the desired type of strapping and, apart from the stop in the strapping position, the conveyance of the objects to be strapped and strapped should remain as continuous and straight as possible. It is also an object of the invention to provide an apparatus for performing the method.

This object is achieved by the method and the device as defined in the patent claims.

The method according to the invention is based on a combination of a longitudinal strapping method with a first strapping material stretched over the conveying path (strapping parallel to the conveying path) and a transverse strapping method, for example with the aid of a channel loop oriented transversely to the conveying path (strapping transverse to the conveying path). The first strapping material is stretched over the conveying path at the entrance to a strapping position and the channel loop is arranged, for example, in the middle of the same, single strapping position (for a substantially central transverse strapping), so that the first strapping material is essentially already wrapped around the object to be strapped when it is stopped in the strapping position. When the object stands still in the strapping position, the transverse strapping is folded, tensioned, closed and severed essentially simultaneously with the tensioning, closing and severing of the longitudinal strapping. So that the longitudinal and transverse strapping can be created independently of one another with a sufficient tension, appropriately designed and driven pressing and optionally stabilizing means must be provided, in particular for the strapping of compressible objects or stacks.

Cross strapping is not initiated for items that are only to be strapped lengthways. For objects that are only to be strapped transversely, the stretched-on first strapping material is shifted such that it runs next to the conveying path or above the conveying path and the object can pass without taking the strapped material with it. For multiple cross strapping, the object can be moved slightly in the strapping position or a plurality of band channels can be provided. For multiple longitudinal strapping, several strapping materials can be stretched through the conveyor path. The strapping material for the longitudinal strapping can be a strapping or a wider wrapping material, such as a plastic film. Such a wrapping material has an arbitrary width, that is, for example, the same width as the objects or stacks to be strapped or wider than this.

Figuren 1 bis 6

aufeinander folgende Stadien des erfindungsgemässen Verfahrens, angewendet für die Längs- und/oder Querumreifung von Stapeln von Zeitungen oder Zeitschriften mit Blickrichtung quer zum Förderweg (Figuren 1 und 4 bis 6) und parallel zum Förderweg (Figuren 2 und 3);

Figur 7

eine Tandemvorrichtung zur Durchführung des erfindungsgemässen Verfahrens;

Figur 8

eine Vorrichtung zur Durchführung des erfindungsgemässen Verfahrens integriert in eine Anordnung zum Herstellen von Kreuzstapeln, zur Bestückung der Stapel mit einem Deckblatt und zur wahlweisen Längs- und/oder Querumreifung des bestückten Stapels.

The method according to the invention is intended to be illustrated with the aid of the following figures in a schematically illustrated exemplary embodiment of the device according to the invention. Show:

Figures 1 to 6

successive stages of the method according to the invention, used for the longitudinal and / or transverse strapping of stacks of newspapers or magazines with a direction of view transverse to the conveying path (FIGS. 1 and 4 to 6) and parallel to the conveying path (FIGS. 2 and 3);

Figure 7

a tandem device for performing the inventive method;

Figure 8

a device for carrying out the method according to the invention integrated into an arrangement for producing cross stacks, for loading the stacks with a cover sheet and for optional longitudinal and / or transverse strapping of the loaded stack.

Figures 1 and 4 to 6 show very schematically an exemplary embodiment of the device for carrying out the method according to the invention with a viewing angle perpendicular to the conveying direction F, in which the stacks S to be strapped are conveyed to the strapping position U and strapped stacks S 'are conveyed away from the strapping position U.

• ein Fördermittel 1 zur Zuförderung von zu umreifenden Stapeln S auf einem Förderweg in die Umreifungsposition U und zur Wegförderung von umreiften Stapeln S' aus der Umreifungsposition U,
• ein Längsumreifungsmittel 2 zum Aufspannen eines ersten Umreifungsmaterials A/A' senkrecht durch den Förderweg und zum Spannen, Schliessen und Abtrennen des ersten Umreifungsmaterials hinter dem Stapel S,
• ein Querumreifungsmittel 3 zum Bilden einer Querschlaufe aus einem zweiten Umreifungsmaterial B und zum Spannen, Verschliessen und Abtrennen der Schlaufe,
• gegebenenfalls ein Verschïebungsmittel zum Verschieben des durch den Förderweg gespannten ersten Umreifungsmaterials A/A' aus dem Bereich des Förderwegs,
• vordere und gegebenenfalls hintere Press- und Stabilisierungsmittel 4 und 5 zur Pressung und Stabilisierung eines Stapels S beim Einlauf in die Umreifungsposition U und während der Umreifung und gegebenenfalls zur Spannung des ersten Umreifungsmaterials A,
• und ein Steuermittel 6 zur Steuerung der genannten Mittel 1 bis 5 und des Verschiebungsmittels für eine wahlweise Erzeugung von Längs- und/oder Querumreifungen um in die Umreifungsposition U geförderte Stapel S.

The strapping position U is equipped with the following means:

• a conveying means 1 for feeding stacks S to be strapped on a conveying path into the strapping position U and for conveying strapped stacks S 'away from the strapping position U,
• a longitudinal strapping means 2 for tensioning a first strapping material A / A 'perpendicularly through the conveying path and for tensioning, closing and severing the first strapping material behind the stack S,
• a cross strapping means 3 for forming a cross loop from a second strapping material B and for tensioning, closing and severing the loop,
• optionally a displacement means for displacing the first strapping material A / A 'stretched through the conveyor path from the region of the conveyor path,
• front and optionally rear pressing and stabilizing means 4 and 5 for pressing and stabilizing a stack S when entering the Strapping position U and during strapping and possibly for tensioning the first strapping material A,
• and a control means 6 for controlling said means 1 to 5 and the displacement means for an optional production of longitudinal and / or transverse strapping around stack S conveyed into strapping position U.

The conveyor 1 is implemented, for example, by conveyor belts 11, 12 and 13, between which a gap for the first strapping material A / A 'is provided at the entrance of the strapping position U and, for example, a gap for the loop made of the second strapping material B in the middle of the strapping position U. are.

The longitudinal strapping means 2 essentially has an upper and a lower supply spool 21 and 21 'of the first strapping material A / A', upper and lower braking / guiding means 22 and 22 'for guiding the strapping material and for generating a tension, as well as upper ones movable relative to one another in the conveying path and lower, cooperating means 23 and 23 'for tensioning, connecting and severing the first strapping material. Such longitudinal strapping means 2 belong to the prior art (see documents cited at the beginning of the prior art) and can be implemented by the person skilled in the art without a more detailed description.

Optionally, the brake / guide means 22 and 22 'are arranged in a coordinated manner perpendicular to the conveying direction F so that they can move the curtain stretched over the conveying path laterally (in the figure perpendicular to the plane of the paper) out of the conveying path, and thus the function of the displacing means take.

Figures 2 and 3 show, viewed from an angle parallel to the conveying direction, such brake / guide means 22 and 22 'in their operative position (Figure 2), in which they tension the first strapping material A / A' through the conveying path, and in their non-operative position (Figure 3), in which they guide the first strapping material to the side of the conveyor path. The brake / guide means 22 and 22 'consist, for example, of a pair of clamping jaws 22.1 and a guide roller 22.2 which can be moved in a plane transverse to the conveying path by means of a lever 22.4 which can be pivoted about an axis of rotation 22.3. Depending on the width and elasticity of the strapping material, it is advantageous to rotate the brake shoe pair 22.1 and guide roller 22.2 and thus the strapping material by 90 ° and also to pivot adjacent deflecting rollers (for example deflecting roller 22.5), as is shown in FIGS. 2 and 3.

The transverse strapping means 3 essentially has a supply spool 31 for the second strapping material B, a loop channel 32 which extends in a loop around the conveying path, and means 33 for introducing the second strapping material B into the loop channel 32 and for folding the loop around the stack and for tensioning, connecting and severing on. Such transverse strapping means 3 are part of the prior art and can be implemented by a person skilled in the art without a more detailed description (see documents cited at the beginning of the prior art).

The device has front and optionally also rear pressing and stabilizing means 4 and 5, in particular for creating tensioned strapping around compressible stacks or objects. The front pressing and stabilizing means 4 essentially acts on the leading stack part and can be moved cyclically, in such a way that it already presses on the stack S as it runs in and thus additionally prevents the individual objects (newspapers or magazines) move relative to each other in the conveying direction F due to the action of the open curtain of the first strapping means A / A '. Depending on the requirements for the longitudinal strapping and its tension, the front pressing and stabilizing means has a gap through which the first strapping material runs, and then does not act on the first strapping material or it also presses on the first strapping material and thus contributes to the tension of the first strapping material around the leading part of the stack to be strapped.

The rear pressing and stabilizing means 5 acts on the trailing stack part and is designed, for example, as a pair of pressing pieces that can be moved up and down, between which the first strapping material runs.

Stabilizing means arranged laterally of a stack to be strapped, as are known from strapping devices according to the prior art, can also be provided for the strapping of unstable stacks.

The control means 6 (shown schematically in FIG. 1 as a box with dashed lines for the device parts to be controlled) are provided with data of the supplied stacks. This data is used to decide whether a stack should be strapped lengthways, crossways, lengthways and crossways or not at all. The data may also be used to decide how far device elements (e.g. elements 23, 4, 5) have to be moved in order to be able to convey a stack to be strapped unhindered to the strapping position, i.e. how large the minimum movement required to remove these device elements from the Funding path is.

Before the entry of a stack S (FIG. 1), which is to be strapped lengthways and crossways, the following device configuration is created with the aid of the control means 6: conveyor means 1 is running, brake / guide means 22/22 'are in the operative rest position (tighten the strapping material the conveying path does not slow it down), means 23/23 'are in the rest position above and below the conveying path, loop of the second strapping material B is prepared in the loop channel 32, front pressing and stabilizing means 4 in an initial position above the conveying path (e.g. in the conveying direction in its rearmost position, shown in solid lines), rear pressing and stabilizing means 5 also in its starting position above the conveying path. The position of the front pressing and stabilizing means 4 shown in dashed lines in FIG. 1 is the rest position, in which it does not extend into the area of the loop channel 32.

When it arrives in the strapping position U, the stack takes along the first strapping means stretched by the conveying path, which is supplied by the two spools 21 and 21 ', whereby known tape storage devices between the supply spool and the conveying path can be provided for fast subsequent delivery.

When the stack S has reached the starting position of the front pressing and stabilizing means 4 (FIG. 4), it is lowered onto the stack and is pressed onto the stack in the conveying direction F. For very unstable stacks, which could be disordered by the strapping material to be taken along, the front pressing and stabilizing means must be designed and moved in such a way that it already accompanies the stack in a stabilizing manner when it hits the first strapping material stretched over the conveyor path.

When the stack is positioned in the strapping position U (FIG. 5), the following actions are triggered: conveyor means 1 (in particular conveyor belts 12 and 13) are stopped and the rear pressing and stabilizing means 5 are lowered onto the stack, braking / guiding means 22/22 'are brought into the braking position, means 23/23' are brought into the action position and activated for connecting and disconnecting the first strapping material A / A 'and at the same time the means 33 for the transverse strapping is activated.

When the two straps have been created (FIG. 6), the following actions are triggered: front and rear pressing and stabilizing means 4 and 5 are raised via the conveying path, means 23/23 'are moved out of the region of the conveying path, and conveying means 1 starts up 'Brake / guide means 22/22' are brought into the rest position, a new loop of second strapping material B is created in the loop channel.

By adapting the height of the rest position of the upper means 23 and the starting positions of the pressing and stabilizing means 4 and 5 to the height of a subsequent stack, the cycle time can be reduced for stacks with a small height and thus an average cycle time can be reduced.

For stacks that are only to be strapped transversely, the first strapping material A / A 'is shifted out of the conveying path by appropriate displacement of the part spanned by the conveying path or by displacing the brake / guide means 22/22' and, if necessary, again for the next stack moved in the conveyor path. Operative and non-operative positions of the brake / guide means 22 and 22 'are shown in Figures 2 and 3.

The means 33 are not activated for stacks which are only to be strapped lengthwise.

It is obviously also possible to let a stack (possibly consisting of only one copy) pass through the strapping position (possibly without a stop) without any strapping.

A number of control processes can obviously be dispensed with for the identical strapping of identical stacks and the corresponding means can therefore be designed more simply.

For strapping objects in contrast to strapping stacks, the first strapping material A / A 'can also be stretched horizontally through the conveying path instead of vertically through the conveying path.

FIG. 7 shows a further embodiment of the device according to the invention. It is a tandem device that straps two objects or stacks per cycle. The device essentially consists of two devices connected in series, as shown in FIGS. 1 to 6, the device parts of which are also designated with the same reference numbers (or with the same reference numbers as .1) as the corresponding device parts in FIGS. 1 to 6. However, only a curtain of the first strapping material A / A 'is provided, which is placed around both supplied stacks S and S.1 and in immediate succession first on the rear of the leading stack S.1 and then on the rear of the trailing stack S is tensioned, closed and separated.

With the aid of the device as shown in FIG. 7, the strapping time can be reduced, with not quite the double equipment being necessary (only two supply spools 21 and 21 'of the first strapping material A / A'). Since either a pair of consecutive stacks S and S.1 can be strapped longitudinally or neither, the flexibility of the device is slightly reduced compared to the flexibility of the device according to FIGS. 1 to 6.

FIG. 8 also shows the integration of a device according to the invention into a processing line in which individual printed products such as newspapers or magazines are fed (arrow C), are stacked in a stacking device 60 with a rotary table to form partial stacks and then to form cross stacks S. The cross stacks are conveyed by means of a slide 14 into the area of a printer and delivery arm 61, by means of which the stack is equipped with a cover sheet. In addition to or instead of the cover sheet, other information carriers can also be added. Again using a slide 14, the loaded stack is conveyed into the strapping position U of the device 62 according to the invention and strapped, as was described in detail above.

It can be seen from the combination example in FIG. 8 how compact such or a similar processing line can be designed using the device according to the invention, which is not only welcomed for reasons of space but also what makes the conveying paths of the not yet strapped and therefore sensitive stacks extremely short and therefore extremely short makes it easy.

The components of such a processing line can be used individually. The point 61 also serves as a calming zone in the the stack is inserted at a relatively high speed, in which it is laterally stabilized and possibly stopped and from which it is moved out at a lower speed. Such a treatment also makes processing very unstable stacks problem-free.

Claims (17)

1. Method for strapping substantially parallelepipedic objects or stacks (S) being conveyed on a conveying path into a strapping position (U) and out of the strapping position (U), wherein the objects or stacks (S) are conveyed against a first strapping or wrapping material (A/A') extending across the conveying path and draw the first strapping or wrapping material (A/A') such that it is laid around the front side of the object or stack, wherein the first strapping or wrapping material (A/A') is closed behind the object or stack, is cut off and positioned across the conveying path again and wherein in the same strapping position (U) a second strapping material (B) is positioned, tensioned and closed around the object or stack perpendicular to the conveying path while the stack is pressed, characterized in that the front part of the object or stack (S) is additionally pressed and stabilized during conveyance into the strapping position (U) with the aid of a pressing and stabilizing means being displaced in conveying direction (F) together the stack, wherein the first strapping material (A/A') runs through a gap in the pressing and stabilizing means (4).
2. Method according to claim 1, characterized in that the first strapping or wrapping material (A/A') is supplied from two opposite sides of the conveying path.
3. Method according to claim 1 or 2, characterized in that for selectively strapping an object or stack with the second strapping material (B) only, the first strapping or wrapping material (A/A') is displaced from the conveying path.
4. Method according to one of claims 1 to 3, characterized in that the first strapping or wrapping material (A/A') is a strapping tape or a plastic film which is connectable by means of welding.
5. Method according to one of claims 1 to 4, characterized in that the second strapping material (B) is a strapping tape connectable by means of welding.
6. Method according claim 1 or 2, characterized in that a first and a second object or stack (S and S.1) are conveyed simultaneously and behind each other into a first and a second strapping position (U and U.1) the second strapping position being arranged behind the first strapping position and that the first strapping or wrapping material (A/A') is closed first between the two objects or stacks and immediately afterwards is closed on the rear side of the second object or stack.
7. Device for strapping substantially parallelepipedic stacks (S) of printed products conveyed on a conveying path into a strapping position (U) and out of the strapping position (U), which device comprises conveying means for sequentially conveying the stacks on a conveying path into the strapping position (U) and out of the strapping position (U) and further comprises, in the region of the strapping position, parallel strapping means (2) for positioning a first strapping material (A/A') across the conveying path and for tensioning, closing and cutting off the first strapping material (A/A') behind a stack (S) conveyed into the strapping position, a means (3) for perpendicular strapping also arranged in the strapping position (U) for forming a perpendicular loop from a second strapping material (B) around the stack conveyed into the strapping position (U) and for tensioning closing and cutting the loop and a means for pressing of the stack (S) in the strapping position, characterized in that the pressing means is designed and arranged as movable pressing and stabilizing means (4) which additionally by means of being conveyed together with the stack acts on the stack in a stabilizing and pressing manner also during the stack's conveyance into the strapping position and that the first strapping material runs through a gap in the pressing and stabilizing means.
8. Device according to claim 7, characterized in that it further comprises displacing means for displacing the first strapping material (A/A') extending across the conveying path out of the same.
9. Device according to claim 7 or 8, characterized in that it further comprises a movable rear pressing and stabilizing element (5) which is arranged movably such that it presses onto the rear part of a stack to be strapped during the strapping process.
10. Device according to one of claims 7 to 9, characterized in that conveying belts (11, 12 13) or pushers (14) are provided as conveying means (1).
11. Device according to one of claims 7 to 10, characterized in that the means (2) for parallel strapping comprises two storage reels (21 and 21') of the first strapping or wrapping material (A/A') arranged on opposite sides of the conveying path as well as two braking/guiding means (22 and 22') and cooperating means (23 and 23') for tensioning, connecting and cutting-off the first strapping or wrapping material (A/A') which means are movable towards each other into the conveying path.
12. Device according to claim 11, characterized in that the braking/guiding means (22 and 22') are movable for displacing the first strapping or wrapping material (A/A') extending across the conveying path.
13. Device according to claim 12, characterized in that the braking/guiding means (22, 22') consist of a pair of clamping jaws (22.1) and a guiding roller (22.2) which are pivotal into a plane perpendicular to the conveying path with the help of a lever.
14. Device according to claim 13, characterized in that the pair of clamping jaws (22.1) and the guiding roller (22.2) are additionally rotatable by 90°.
15. Device according to one of claims 7 to 14, characterized in that the means (3) for perpendicular strapping comprises a storage reel (31) for the second strapping material (B), a tape channel (33) running around the conveying path in form of a loop and means (33) for introducing the second strapping material (B) into the tape channel (32) and for laying the loop around the object or stack positioned in the strapping position (U) as well as for tensioning, closing and cutting off the loop.
16. Device according to one of claims 7 to 15, characterized in that it comprises a double strapping position (U and U.1) for two successive objects or stacks (S and S.1) with one sole curtain of the first strapping material (A/A') extending across the conveying path.
17. Use of a device according to one of claims 7 to 16 in a processing line in which newspapers or magazines are stacked, the stacks are equipped with a covering sheet and/or carrier of information and are then selectively strapped perpendicular and/or parallel to the conveying direction.