EP1279489A2 - Method and apparatus for removing stacks of bags from a chain of stacked bags - Google Patents

Abstract

To extract a stack of bags, from a chain of bag stacks, the bag stack (14) is gripped at a take-off station (26) by a robot arm (28) with grips. A spindle with an expanding peripheral surface, at the robot side, expands the hollow pin (16) so that the pin clamping flanges (18) are released. The bag stack is taken from the carrier belt (20) by the robot, to be laid on a table or a conveyor belt.

Description

The invention relates to a method for removing stacks of bags, in particular consisting of plastic packaging bags, from a stack of bags and a device for carrying out this method.

In the previously unpublished earlier application DE (Az. 01638-01) a method for summarizing bags in the form of bag stack chains is already described. These bag stack chains are usually made up of plastic, preferably polyethylene, bags. According to this embodiment described there, the plastic packaging bags are arranged in the form of a bag stack chain on a carrier tape. The bags combined in the stack of bags are connected to one another via lips formed on their open side and are attached to a carrier tape in a scale-like manner by means of a fastening means. This fastener consists of a hollow pin in the core with a pin lock. In the aforementioned application it is described in detail how the bag stack chain can be produced mechanically by applying bag stacks to the carrier tape. In the aforementioned application the bag stack chains are wound up in coils in which the bag stacks lie on the outside of the carrier tape and are wound up accordingly. Conversely, the stacks of bags can of course also be rolled up on the inside of the carrier tape to form a wrap.

The object of the present invention is to remove a method for removing stacks of bags from such a stack of bags and to provide an apparatus for carrying out this method.

According to the invention, this object is achieved by the features of claim 1. Accordingly, a method for removing bag stacks of the structure, as detailed in the preamble of claim 1, is proposed, in which the bag stack is gripped by a robot arm by means of grippers in a removal station, the pin closure being separated from the pin by suitable means , According to a preferred embodiment of the invention, which is protected in claim 2, at least one robot-side mandrel with an expandable peripheral surface is inserted into the hollow core of the pin and the pin is expanded by expanding the peripheral surface of the mandrel to such an extent that the clamped Pin lock is released and that the stack of bags is lifted from the carrier tape via the robot-side grippers.

Further preferred refinements of the method result from claims 3 to 6.

Accordingly, the stack lifted off the carrier belt by the robot-side grippers can be placed on a table or a conveyor belt in such a way that the at least one mandrel provided on this conveyor belt or table can be inserted into the recesses in the stack of bags, the at least one pin which has previously connected the stack of bags to the carrier belt while pulling out the stack of bags on the conveyor belt or table.

The stack of bags gripped by the robot-side grippers can, after being lifted off the carrier belt, be positioned above the storage position above the conveyor belt or table and can be lowered by lowering the robot-side gripper arms relative to the robot-side mandrel, with which the hollow pin in the core is fixed. As a result of this lowering, the pin that is hollow in the core is pulled out of the corresponding opening in the stack of bags and at the same time the stack of bags is pushed onto the mandrel positioned on the conveyor belt or the table by means of this opening. After delivery, the stack of bags can be fed to a filling station in a manner known per se via a conveyor belt.

It is particularly advantageous if the bag stack chain for unloading the individual bag stack is unwound from a winding, the bag stack chain or the carrier film of this bag stack chain being guided over deflection rollers and the bag stack of the bag stack chain being fed to the removal station in cycles and removed there by means of the robot arm. After the respective stack of bags has been removed, the carrier film is wound up again on a roll.

During transport into the removal station, the individual stacks of bags are inserted with the pin lock into a corresponding slot in a support plate and fixed there for removing the stack of bags. As a result, the position of the respective pins is clearly defined, so that the robot-side gripper with the corresponding mandrel can engage securely in the interior of the hollow pins.

Devices for carrying out the method according to the invention result from claims 7 to 10. Accordingly, according to the invention the robot arm has lateral grippers by means of which the stack of bags can be gripped from the side.

The expandable peripheral surface of the robot-side mandrel can consist of a rubber bead that can be arched out by shortening the mandrel.

The free end of the robot-side mandrel can have a widened head in such a way that it can eject the released pin lock from the hollow core of the pin.

At least one photocell can be arranged next to the course of the carrier film in such a way that the removal position of the stack of bags can be defined. For this purpose, the photocell detects the return or leading edge of a stack of bags, which usually protrudes laterally over the carrier film, so that the exact position of the stack of bags in the removal station can be determined here.

Instead of the robot-side mandrel with an expandable peripheral surface, it would also be conceivable that the means for expanding the hollow core of the pin consist of three or more fingers which are arranged on the gripper in such a way that they can be moved towards and away from one another and thus similarly the previously described robot-side mandrel can expand the hollow core of the pin. However, other similarly acting means for separating the pin lock from the pin can also be used.

Fig. 1:

eine Vorrichtung zur Entnahme eines Beutelstapels von einer Beutelstapelkette gemäß der vorliegenden Erfindung in vereinfachter seitlicher Darstellung, teilweise geschnitten,

Fig. 2:

ein Detail der Vorrichtung gemäß Fig. 1, entsprechend dem Schnitt o-o nach Fig. 3, wobei hier noch eine weitere Verarbeitungsstation gezeigt ist,

Fig. 3:

eine Draufsicht auf die Vorrichtung gemäß Fig. 1 sowie die weitere Vorrichtung nach Fig. 2,

Fig. 4:

einen Schnitt n-n gemäß Fig. 1,

Fig. 5:

einen Schnitt m-m gemäß Fig. 1 in einer ersten Arbeitsphase während der Entnahme des Beutelstapels,

Fig. 6:

einen Schnitt m-m gemäß Fig. 1 in einer zweiten Arbeitsphase während der Entnahme des Beutelstapels und

Fig. 7:

eine den Figuren 5 und 6 entsprechende Darstellung während des Ablegens des Beutelstapels auf dem Vorderband bzw. Tisch gemäß Fig. 3.

Further details and advantages of the invention result from an embodiment shown in the drawing. Show it:

Fig. 1:

1 shows a device for removing a stack of bags from a chain of stacked bags according to the present invention in a simplified side view, partly in section,

Fig. 2:

2 shows a detail of the device according to FIG. 1, corresponding to the section oo according to FIG. 3, a further processing station being shown here,

Fig. 3:

2 shows a top view of the device according to FIG. 1 and the further device according to FIG. 2,

Fig. 4:

2 shows a section nn according to FIG. 1,

Fig. 5:

1 in a first working phase during the removal of the stack of bags,

Fig. 6:

a section mm of FIG. 1 in a second phase during the removal of the stack of bags and

Fig. 7:

5 shows a representation corresponding to FIGS. 5 and 6 while the stack of bags is placed on the front belt or table according to FIG. 3.

1 shows a device for carrying out the method according to the invention, which is designated overall by 10. Here, a roll 12 of a bag stack chain is unwound and the individual bag stacks 14 are removed. The stack of bags 14 are connected to a carrier film 20 via pins 16, which are closed by means of a pin lock 18. In the present exemplary embodiment, the bag stack chains are wound onto the winding 12 in such a way that the carrier tape 20 lies on the outside, so that the respective bag stacks 14 come to lie below the associated carrier tape 20. The bag stack chains are unwound from the winding 12 and guided over deflection rollers 22, 24.

In a removal station 26, the individual stacks of bags 14 are gripped by a robot arm 28 and released from the carrier tape 20 in a manner described in more detail below. After the stack of bags has been removed, the now empty carrier tape 20, after being deflected around the deflecting roller 24, is again rolled up into a roll 30.

According to FIG. 2 it is shown how the robot arm 28 (partially shown in broken lines) places the detected stack of bags 14 on a table 32 of a filling machine known per se.

The situation of removing the device 10 and placing it on the table 32 is shown from above again in FIG. 3, the robot in the different positions being shown here partly in broken lines and partly in solid lines. The carrier tape 20 is moved in the direction of arrow a in FIG. 3. The table 32 can be moved back and forth so that the stacked bags 14 are fed to a filling funnel, not shown here, which is only indicated by an arrow F.

With reference to FIGS. 4 and 6, it will now be described how the stack of bags 14 is removed in the removal station 26. The position of the removal station 26 is defined by a plate 34 running underneath the carrier tape 20, the plate 34 having a slot in the region in which the pins 16 are arranged for receiving these pins 36. If, as shown here, two pins 16 lying parallel to one another are provided, two slots 36 arranged next to one another are provided in the corresponding plate 34. During the movement of the carrier tape with a corresponding stack of bags, the pins 16 connecting the bag stack 14 with the carrier tape 20 are inserted with their pin lock 18 into the corresponding slots 36 and fixed there at the end. When the end of the slots 36 is reached, the stack of bags 14 is fixed in place in the removal station 26. The reaching of this removal position is monitored by one or more photosensors 38 (cf. also FIG. 1).

The section mm in FIG. 5 now shows what happens after the bag stack 14 has been fixed in the removal position. Lateral grippers 40 for gripping the edge of the stack of bags are provided on the robot arm 28. As shown in Fig. 5, the grippers 40 are controlled after reaching the removal position. 6, the grippers are shown in a solid line in the controlled position in which they hold the edge of the stack of bags 14. After holding the stack of bags by the grippers 40, a mandrel 46 moves into the central cavity 48 of the pin 16 via corresponding lifting cylinders 42 and a parallel guide 44. The mandrel 46 has a sheath 50 made of rubber, which is compressible over the movable pin 54 provided with a head 52 such that the circumference of the mandrel 46. After the mandrel 46 has been moved in via the lifting cylinder 42 into the interior of the pin 16, the movable pin 54 is withdrawn via a clamping cylinder 56 to such an extent that the rubber jacket 50 bulges out and thereby fixes and expands the pin 16 due to its circumferential expansion. As a result, the pin lock 18 received in a clamping manner is loosened, so that it falls out of the pin 16 essentially due to gravity and can be collected in a container 58 (cf. FIG. 1). If necessary, the pin lock can also be additionally pushed out of the pin by appropriate movement of the pin head 52. After appropriate removal of the pin fastener 18, the stack 14 can be removed from the carrier tape 20 and moved in the manner already described to the table 32 on which mandrels 62 are arranged in each case. These mandrels can be seen in FIG. As a result, the stack of bags 14 is withdrawn from the pin 16, which is still fixed via the mandrel 46. The opening that is released is plugged onto the table-side mandrel 62. After appropriate positioning on the mandrels 62, the grippers 40 are moved in the direction of arrow b in FIG. 7 to an open position (in dashed lines) and the robot arm can be moved back again to start a next removal cycle.

After the stack of bags has been put down, it is further processed in the filling station in a known manner.

Claims (10)

Method for removing bag stacks, in particular consisting of plastic packaging bags, from a bag stack chain, which consist of bag stacks with several bags arranged on a carrier tape, the bag stacks being connected to the carrier tape via at least one pin hollow in the core with a pin lock clamped in,
characterized,
that in a removal station the bag stack is gripped by a robot arm by means of grippers and the pin lock is separated from the pin by suitable means. Apparatus according to claim 1, characterized in that as a means for separating the pin lock from the pin at least one robot-side mandrel with an expandable peripheral surface is inserted into the hollow core of the pin, that the pin is expanded by expanding the peripheral surface of the mandrel to such an extent that the pin lock that is clamped in is solved and that the stack of bags is lifted from the carrier belt via the robot-side grippers. Method according to claim 2, characterized in that the stack lifted from the carrier belt by the robot-side grippers is placed on a table or a conveyor belt in such a way that the at least one mandrel provided on this conveyor belt or table can be inserted into the recesses in the stack of bags, wherein the at least one pin that previously connected the stack of bags to the carrier belt is pulled out while the stack of bags is being placed on the conveyor belt or table. A method according to claim 3, characterized in that the stack of bags gripped by the robot-side grippers is positioned after being lifted off the carrier belt above the storage position above the conveyor belt or table and by correspondingly lowering the robot-side gripper arms relative to the robot-side mandrel with which the hollow in the core Pin is set, is lowered. Method according to one of claims 1 to 4, characterized in that the bag stack chain for the removal of the individual bag stacks is unwound from a roll and is guided over deflection rollers and that after removal of the respective bag stack the carrier film is wound up again on a roll. Method according to one of claims 1 to 5, characterized in that the individual stack of bags during transport into the removal station with the Pen lock moves into a corresponding slot in a support plate and is fixed there for removing the stack of bags. Device for carrying out a method according to one of claims 1 to 6, characterized in that the robot arm has lateral grippers, by means of which the stack of bags can be gripped from the side. Apparatus according to claim 7, characterized in that the expandable peripheral surface of the robot-side mandrel consists of a rubber bead which can be arched out by shortening the mandrel. Apparatus according to claim 8, characterized in that the robot-side mandrel has a widened head at its free end such that it can eject the released pin lock from the hollow core of the pin. Device according to one of claims 5 to 9, characterized in that at least one photocell is arranged next to the course of the carrier film in such a way that the removal position of the stack of bags can be defined.

Images