FR2708518A1 - Device for folding and gluing of bags. - Google Patents

Abstract

The invention relates to a device for folding and gluing bags. This device (10) comprises a first gripper cylinder (12) and a first knife cylinder (16) and a glue bar to form a folded and glued bottom flap. A second gripper cylinder (24) arranged consecutively with several grippers (26, 28) is additionally provided. Associated with this is a second knife cylinder (30) which is provided with a folding knife and a suction element. Next to the second knife cylinder (30) is a fan rake (36) with spiral, curved conductive plates. In the direction of rotation of the second gripper cylinder (24), a conductive sheet (40) is arranged afterwards. The invention is applicable in the field of packaging.

Description

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  The invention relates to a device for folding and gluing bags with a first gripper cylinder and a first knife cylinder and a glue bar, respectively, cooperating therewith to form a folded and glued bottom flap. Such devices are already known. In these, bags open on both sides, for example side pleated bags, are glued in the format and folded by means of sizing bars cooperating with the gripper cylinders and a first knife cylinder and are folded down. by a conductive sheet or by an application strip passing over the surface and which is arranged after the knife cylinder in the direction of rotation of the gripper cylinder. The bottom flap formed correspondingly tends, until the glue has taken, to open under the elastic action of the paper. For this reason and to form stacks of less bulky bags it is desirable to fold once or more times the closed bags on one side by a bottom flap. The invention relates to the improvement of a generic device for folding and gluing bags so that after the formation of the bottom flap, repeated folding bags can be performed continuously. These measures

  must be small in size and operate continuously.

  According to the invention, this object is achieved starting from a device of the generic type by the characteristics indicated below. A second gripper cylinder having a plurality of grippers integrated in the gripper cylinder casing, extending transversely thereto and distributed around the periphery, is arranged after the first gripper cylinder in the conveying direction. This second gripper cylinder is associated first of all with a second knife cylinder which, apart from a folding knife, has a suction element. Looking in the direction of transport, a so-called fan-shaped rake is disposed directly next to the second knife cylinder, which consists of curved conductive sheets and protruding spiral

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  of a roll. In the direction of rotation of the second gripper cylinder, there is further arranged a conductive sheet

  extending transversely to the second gripper cylinder.

  The bags provided on the first bottom flanged cylinder are conveyed to the second gripper cylinder where the front end is sucked by a corresponding suction element of the second knife cylinder and is removed from the circumferential surface of the second cylinder. with pliers. With the folding knife of the second knife cylinder, a collet cylinder recess is formed in cooperation with a recess.

  first fold line extending transversely to the bag.

  The clamp in the corresponding recess of the tong cylinder is closed and squeezes the bag along this fold line. The bag transported in the direction of rotation of the second gripper cylinder in the meantime is then gripped by one of the curved conductive sheets, spirally wound from a roll, of the fan-shaped rake and is folded by the latter on the next part behind the folding line of the bag. The fan rake rotates during this movement. The fan-shaped rake, through kinematic cooperation with the knife cylinder and gripper cylinder, ensures that the folded bottom flap, which always has a tendency to open, can not open in an uncontrolled manner. The bag is folded in such a way on itself that the folded bottom flap is located between the two bag walls lying one on the other and is fixed by them. Such a device makes it possible to fold a corresponding bag, after forming the bottom flap, once

on himself.

  According to a preferred embodiment of the device, the bag, after the completion of the bottom flap, can be folded twice on itself. To this end, there is provided a third knife cylinder which cooperates with the second gripper cylinder. In the second gripper cylinder, two perimeter grippers cooperate to grip the bags adjacent the fold formed by the second and third knife cylinders, respectively. When the bag folded

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  When one arrives at the vicinity of the second knife cylinder, the second folding knife disposed thereon sinks into the bag and forms a second fold line along which the bag is gripped in the second tong cylinder by a second clip. The first clip which had retained the first fold line, as described before, is simultaneously opened so that the front end of the folded bag becomes

  releases from the periphery of the second gripper cylinder.

  By means of another curved conductive sheet which follows in

  the direction of rotation, the bag is folded again.

  According to one embodiment of the invention, between the first and the second gripper cylinder, an additional cylinder can be arranged around which the bags provided with the folded bottom flap are passed through a belt.

application.

  A band assembly comprising an upper pressure band and a lower pressure band can be provided to receive the folded bags several times from the second gripper cylinder and then to transport them, and by the application of the strips it is ensured that the folded bags correspondingly do not open again under the

elastic force of the paper.

  The invention will be better understood, and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatory text which will follow with reference to the accompanying schematic drawings given solely by way of example illustrating an embodiment of the invention, and in which: - Figure 1 is a schematic side view of an embodiment of the device according to the invention; FIGS. 2a and 2b show two alternative folding possibilities of a bag provided with a folded bottom flap; - Figure 3 is a schematic side view, in detail, according to Figure 1;

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  - Figure 4 shows a bag with a folded bottom flap at different fold states; and FIG. 5 is a block diagram showing the depression of a folding knife in cooperation with the gripper cylinder. The device 10 shown in FIG. 1 has a gripper cylinder 12, the production of which is mainly known, and whose envelope comprises on its periphery recesses 14 in which are arranged clamps that can be moved apart and approached in a manner that is also known. With this gripper cylinder which rotates in the direction of the arrow a cooperates a knife cylinder 16 and a glue bar which is not shown in more detail. By means of the glue bar, a bag section shown for example in FIG. 2a is sized in size and is then folded onto the knife cylinder so that the front end of the bottom flap is disengaged from the pliers cylinder. 12. By the pressure band 18 arriving tangentially to the gripper cylinder 12, the bottom flap is folded, and between the application belt 18 and the peripheral surface of the gripper cylinder 12, the bag with the folded bottom flap is transported further. It is then returned to the rotating cylinder in the direction of the arrow b and is transported between the peripheral surface of the cylinder 20 and the pressure band 22 before being transmitted to the second gripper cylinder 24 where it is transported between the belt 18 and the periphery of the second

clamp cylinder 24.

  The second gripper cylinder 24 rotates in the direction of the arrow e. Arranged on the circumferential surface of the second gripper cylinder are clamps 26 and 28 respectively arranged one after the other, integrated into the casing of the gripper cylinder and extending transversely to that -this. The assembly and operating mode of the gripper cylinder 24 is shown in FIGS. 1 and 3. The bags with the folded and glued bottom flap are first transported between the circumferential surface.

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  clamp cylinder 24 and turntable 18, the bag 11 being disposed on the gripper cylinder 24 so that its bottom flap is located in front. A second knife cylinder 30 follows in the direction of rotation of the gripper cylinder 24 to the application belt 18 which is applied to the circumferential surface and which is provided with a knife 32 and a

  suction device 34, as shown in FIG.

  The suction device 34 draws the bottom flap in front of the bag 11 and releases it from the peripheral surface of the second gripper cylinder 24. The folding knife 32 of the second knife cylinder, which turns in the direction of the arrow c, sinks in a desired spacing and forms a corresponding fold which is clamped by the clamp 26. The bag 11 thus clamped along the fold line is transported in the direction of rotation e and is grasped by a fan rake 36 rotating in the direction of rotation d. The fan rake 36 is provided with curved and spirally protruding conductive sheets 38 of a roll and which are formed and arranged to prevent opening of the folded flap not yet adhered to the bag 11. As shown in FIG. 3, the conductive sheets 38 respectively urge the front end of the bag 11. The curved conductive sheets arranged in a spiral shape are sufficiently close together to prevent opening of the bottom flap. They place the bottom flap, the folded part being oriented downwards, on the envelope

clamp cylinder 24.

  Then, the folded bag and around a first fold line passes under a conductive sheet 40. A la

  Following this is provided a pressure roller 42.

  Behind the pressure roller 42, a third knife cylinder 44 rotating in the direction of rotation f is arranged in the direction of rotation e. With a knife 46 a second fold line is formed. Upon depression of the folding knife 46, the clamp 26 is opened and the clamp 28 to grip the bag near the second fold line is closed. As a result, the front end that had

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  has been retained until now by the clamp 26 is lifted in the direction of the arrow g (Figure 3) of the peripheral surface of the second clamp cylinder 24. By a correspondingly formed conductive plate 48, the bag 11 is folded around the second fold line. Then, the folded bag is grasped by a band assembly 50 and is transported further between a top pressure band.

  52 and a lower pressure band 54.

  As shown in Figures 2a and 2b, the bag 11 with the bottom flap 13 is folded twice along a plurality of fold lines. The fold lines may be provided at different lengths, which is apparent from a comparison of Figures 2a and 2b. The folding of the bag 11 according to FIG. 4 shows the different stages of folding.

  to which the bag 11 is subjected in FIG.

  FIG. 5 shows on a larger scale how the folding knife 46 of the third knife cylinder 44 enters the bag 11. As can be seen from the right part of FIG. 5, the folding knife 46 comes into contact with the bag 11 in the vicinity of the folded bottom flap and then slides to form at the folding line of the bottom flap the fold line (left part of the figure). This folding corresponds to the folding example shown in FIG. 2a and FIG. 4. When the folding knife 46 is depressed, the upper free bag portion is retained and pressed into the clip 28. An uncontrolled opening of

  the upper bag portion is thus prevented.

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Claims (5)

  1. Device (10) for folding and gluing bags (11) with a first gripper cylinder (12) and a first knife cylinder (16) and a glue bar respectively cooperating therewith to form a folded and glued bottom flap, characterized by a second gripper cylinder (24) subsequently arranged comprising a plurality of grippers (26, 28) integrated in the gripper cylinder casing, extending transversely thereto and distributed a second knife cylinder (30) associated therewith which, apart from a folding knife (32), has a suction element (34), a fan rake (36) disposed adjacent to the second knife cylinder (30) which is provided with spirally extending conductive plates (38) of a roller and a conductive plate (40) arranged in the direction of rotation of the second gripper cylinder (24) following and extending transversely to the second gripper cylinder. 2. Device according to claim 1, characterized in that a third knife cylinder (44) cooperates with the second gripper cylinder (24), and that in the clamp cylinder respectively two clamps (26, 28) which follow one another on the periphery cooperate to seize the bags (11) in the vicinity of the fold formed by the second and third cylinders to knife (30, 44).   3. Device according to claim 2, characterized in that is disposed after the third knife cylinder (44) in the direction of rotation of the second clamp cylinder (24) a conductive sheet (48) extending   transversely to the second gripper cylinder.   4. Device according to one of claims 1 to 3,   characterized in that there is arranged between the first and second gripper cylinders (12, 24) an additional cylinder around which the bags are passed (11). 8 2708518   with folded bottom flap (13) by means of a band   of application (18). 5. Device according to one of claims 1 to 4, characterized in that there is provided a band assembly (50)   with an upper pressure band (52) and a lower pressure band (54) for receiving the folded bags (11)   several times of the second gripper cylinder (24) and to carry them further.