EP2594490B1 - Sack separation device and method for separating sacks - Google Patents

Description

The present invention relates to a bag separating device and a method for separating bags.

In the prior art, bag separating devices with a bag magazine for storing prefabricated bags are known, which have a bag removal device associated with the bag magazine for removing a bag to be separated from the bag magazine. The bag-separating device further has a transport path for discharging the separated bag from the bag-separating device.

The generic bag separating device is usually realized as part of a bag filling device. The sacks are, in particular, prefabricated sacks which are open on their filling side and are also referred to as open sacks. Such bags are supplied by the bag maker, an operator of the bag filling device in a stacked form. In this stacked form, the bags are placed in the bag magazine. In this case, the bag layer in the magazine must not have such an orientation that the bags lie one above the other in the vertical. Rather, the bags can also be provided obliquely or in vertical alignment next to each other in the bag magazine.

The previously known from the prior art bag separating device has a gripping arm for removing a bag to be separated, which is pivotally mounted and provided with a suction bridge which usually engages the sack to be separated at a front end and feeds a conveyor within the bag separating device and the isolated Sack of the sack removal device takes over and promotes the transport route. The transport route can be a slide on which the isolated bag slips off. It is also conceivable embodiment of the transport route by a circulating conveyor belt. Each transport path of the individual unfilled sacks from the sack-separating device can be regarded as a transport route within the meaning of the invention.

In the previously known conveyor is a circulating belt or transport chains with a plurality of successively provided in the direction of rotation entrainment portions which extend beyond the extending therebetween and each edge Belts or chains are connected to each other to one. The chains or belts form a window between adjacent driver sections, through which the separated sack is transported by pivoting the sack removal device into the interior of the revolving belt or chains and is carried along by the follower section following in the direction of rotation. The bag removal device usually attacks the bag at its rear end in the direction of transport. Accordingly, the isolated bag is raised in total by the carrier section running under the bag and placed on the inside of the driver section. Thereafter, the sack removal device releases the sack, so that it is first moved in a translatory manner by the sack removal device via the circulating belt. Usually, the isolated bag is already transferred at the level of the first deflection roller of the rotating belt or the chains of the conveyor to the transport device.

The previously known system allows an output of about 900 bags per hour, which is unsatisfactory.

Another bag separating device is off WO 03/089349 A1 known.

The present invention has for its object to provide a bag separator with higher output. Furthermore, the present invention wants to specify a method for separating bags from a bag magazine, which allows a high output.

In view of the device-related problem, the present invention provides a bag-separating device having the features of claim 1. This differs from the prior art by a transport path upstream bag pivoting device, with which the isolated bag can be brought from the bag removal device to the transport path by pivoting about a pivot center.

In this case, the pivoting movement of the bag usually follows a different kinematics than the pivoting movement of the sack removal device, provided that - as in the prior art - is formed by a pivotable arm with a suction bridge. Rather, the pivoting movement takes place by the pivoting device according to the invention by pivoting about a pivot center, which does not coincide with the pivot axis of the sack removal device, if this comprises a pivoting arm, on the Swivel axis insofar reference is made. The pivoting device is preferably designed so that the isolated bag is pivoted through an angle of at least 220 °, preferably 270 °. It is usually a circular, continuous in one direction pivoting movement. The radius of the pivoting movement and the speed of the pivoting movement are such that the isolated bag can be pivoted after transferring to the pivoting device on the one hand at high speed for transfer to the transport route, on the other hand but a change in position of the bag due to the centrifugal force occurs, the the bag during the pivoting movement substantially transferred from the predetermined by the bag magazine orientation in an orientation which must take the bag for discharge via the transport path, whereby the output of the bag separating device according to the invention can be high.

According to the present invention, the bag separating device has a bag guide surface formed as part of the bag pivoting device, which circumferentially surrounds the pivoting center and is associated with a gripping device mounted pivotably about the pivoting center. The Sackleitfläche is preferably formed as a rule stationary, the pivot center at least partially surrounding cylindrical surface formed.

The bag-separating device includes the bag-pivoting device which contains the bag-gripping device and the bag-guiding surface. The bag gripper, z. B. a suction bridge, this is associated with the Sackleitfläche and itself, following the contour of the Sackleitfläche, pivotally mounted. The preferably fixedly arranged sack removal device is preferably assigned to the sack magazine, from which the prefabricated sacks are taken, that this sack removal from the sack magazine at a transfer position, the removed bag passes the gripping device. The gripping device is preferably designed such that the sack at the transfer position takes over and this leads along the Sackleitfläche up to a dispensing position at which the bag is deposited by the Sackleitfläche on the transport route. The transfer position is in this case preferably upstream of the bag guide surface.

The Sackleitfläche is advantageously a flat, uninterrupted section and in particular made of a sheet or plastic. The Sackleitfläche is preferably positioned such that it is provided between the pivoting center of the gripping device and the gripping device itself or the gripped bag. Consequently, the bag is guided by this construction, for example, when the Sackleitfläche is formed as the pivot center at least partially surrounding cylindrical surface, with respect to the pivot center on the outside of the pivot center side facing away from the Sackleitfläche. This Sackleitfläche is stationary, wherein the gripping device holds the gripped bag preferably only at one of the bag ends, in particular at a closed end of the bag. The bag itself is consequently held pivotably by the gripping device about a holding axis extending transversely to the longitudinal direction of the bag in the region of the sack end. This makes it possible that the bag is turned in the course of depositing on the transport path exactly to this holding axis formed by the gripping device and stored in the opposite direction, as he has been removed from the bag magazine on the transport route.

The sack removal device and the sack pivoting device are preferably designed as two separate units, wherein in particular a removal center of the sack removal device is provided outside of an enveloping surface formed by the Sackleitfläche. In particular, it is preferable to position the removal pivot center of the sack removal device between the sack magazine and the transport section in such a way that the removal swivel center is also positioned below, ie between the sack guide surface and the sack magazine.

Particularly advantageous is the formation of a natural air cushion between the bag and the Sackleitfläche, so that the bag on the air cushion and slides past the Sackleitfläche without contact. For this purpose, the rotational speed of the bag should be greater than 1.5 m / sec with respect to the Sackleitfläche. It is particularly preferred to select the circulation speed even greater than 3 m / sec, very particularly preferably even greater than 8 m / sec. However, the rotational speed should also not be too high, so that the bag is not pivoted on the grasped by the gripper end about the holding axis due to its inertia, that of a guide along the Sackleitfläche no longer be the question. The guide on the Sackleitfläche is in any case given if the contour of the bag substantially follows the contour of the Sackleitfläche while the gripping device pivots the bag around the Sackleitfläche.

High circulation speeds of greater than 10 m / sec can therefore also be unfavorable. It may even be that, under certain circumstances, even rotational speeds greater than 3 m / sec are not advantageous. This always depends on the particular geometry of the Sackleitfläche itself.

Consequently, it is particularly preferred that the sack transport along the stationary sack guide surface be substantially smooth, i. E. the bag does not or not substantially touch the bag guide surface itself during pivoting.

Incidentally, it is advantageous for the bag-sorting device according to the invention that it contains substantially three units positioned separately from one another. These are the sack removal device and the sack magazine as a unit, the Sackleitfläche and the bag gripper as a second unit and separately provided, the conveyor belt as a third unit.

The Sackleitfläche must not fully surround the pivot center. It is only important to form an intended for the isolated bag baffle, against which this at least temporarily during pivotal movement and at least partially can be brought to bear in order to transfer the bag from the sack removal device on the transport path in a predetermined manner as part of a pivoting movement , The pivotably mounted about the pivot center gripping device usually runs around the Sackleitfläche. It can be guided on the Sackleitfläche. Usually, however, the gripping device has a pivot arm, which articulates about the pivot center and carries a gripper, which rotates on the side facing away from the pivot center of the Sackleitfläche about this. In this case, the gripper between the Sackleitfläche and an outer guide surface may be provided which surrounds the Sackleitfläche completely or partially, to hold the bag on a predetermined trajectory.

According to a preferred embodiment, namely, the bag pivoting device is designed so that it seizes the isolated bag only at its closed end, which forms an anticipatory end in the pivotal movement of the bag around the pivot center, which leading end is formed by a closed end of the pre-assembled bag. In other words, the sack is usually gripped at its closed end and with this end in an anticipatory direction pivoted the transport route. The sack removal device for separating a sack from the sack magazine preferably also grips the sack at its closed end. Thereafter, the sack removal device is designed so that it cooperates with the sack to be separated and still arranged in the sack magazine at the end at which the closed end of the sack is located. The sack removal device accordingly does not attack the entire surface of the bag, but only the edge and can - as in the prior art - have a suction bridge to grab the sack to be separated regularly almost over its entire width and pick up from the bag magazine.

The separating device has a blowing device, which comprises a blowing nozzle arranged between the bag and the pivoting center, by means of which the separated bag can be removed from the bag guide surface. Usually, the blowing device is controlled so that it acts only pulse-like manner on the bag, preferably acts on the non-gripped, free and trailing end of the bag such that this end is pivoted about the preferably still firmly held by the gripper end when the Sack approaches as part of the pivoting movement of the transport route. Thus, the development of the present invention allows a change in position and / or shape of the bag in the context of the pivoting movement such that it is stored in the context of as smooth as possible movement of the pivoting device on the transport path.

The tuyere is arranged according to a preferred embodiment of the present invention above the transport path, so that in addition to the induced by the tuyere movement of the bag also gravity contributes to the most uniform and effective movement of the bag for storage of the same on the transport route.

The dispensing position at which the sack is deposited by the Sackleitfläche on the transport path is preferably provided in the region of the tuyere, which is associated with the Sackleitfläche, with which tuyere the sack while this end of the gripping device is still held, in order then the formed holding axis, which usually extends transversely to the bag longitudinal direction in the region of the held end of the bag, is pivoted and stored on the transport path.

With regard to the procedural aspect of the present invention, a method having the features of claim 6 is provided. Accordingly, the aforementioned device-related features also characterize the method of pivoting the bag. In this method, a single bag is removed from the bag magazine in a previously known manner for separating sacks and transferred to a transport route. After removing the isolated bag from the bag magazine, however, the bag is pivoted, i. moved in a circular motion about a pivoting center, as previously described in the apparatus aspect of the present invention. In particular, the method is thus to be carried out so that the sack is guided substantially smoothly and / or smoothly along the sack guiding surface.

Preferred developments of the method according to the invention are specified in claims 10 to 13.

The pivoting movement about the pivoting center is further preferably controlled so that the usually free, trailing end in the context of the pivotal movement by centrifugal force radially with respect to the pivoting movement to the outside, i. is moved away from the pivot center. To transfer to the transport path, the leading end is preferably initially passed past the intended nozzle before a blow delivered from the blower impulse is given to the bag to the trailing end of the bag - supported by the Blasimpuls - impart a movement direction, with which the trailing End led in the direction of the transport route, preferably approximately tangentially to the transport path and from above on this is stored. Depending on the desired kinematics, the pivoting speed of the bag on the bag pivoting device and the strength of the Blasimpulses before, during or after giving up the Blasimpulses the leading end of the bag is released, so that the bag is removed from the bag pivoting device and stored on the transport route ,

Thereafter, the bag is pivoted in particular at the transfer of the bag pivoting device on the transport device to its leading end. In support of this pivoting movement, the pivoting movement about the pivot center, that is, the pivoting movement, by which the bag is conveyed in total by the sack removal device to the transport path, strongly braked. By this braking the pivoting of the bag is favored around the leading end.

Figur 1

eine Seitenansicht des Ausführungsbeispiels in einem Betriebszustand, bei dem ein zu vereinzelnder Sack aus dem Sackmagazin entnommen wird;

Figur 2

das Ausführungsbeispiel bei Übergabe des vereinzelten Sackes an die Sackschwenkeinrichtung;

Figur 3

das Ausführungsbeispiel beim Bewegen des vereinzelten Sackes auf der Sackschwenkeinrichtung; und

Figur 4

einen Betriebszustand, bei welchem der vereinzelte Sack auf die Transportstrecke überführt wird.

Further details and advantages of the present invention will become apparent from the following embodiment in conjunction with the drawing, which schematically illustrates an embodiment of the present invention. In this show:

FIG. 1

a side view of the embodiment in an operating condition in which a bag to be separated from the bag magazine is removed;

FIG. 2

the embodiment when transferring the isolated bag to the bag pivoting device;

FIG. 3

the embodiment when moving the isolated bag on the bag pivoting device; and

FIG. 4

an operating state in which the isolated sack is transferred to the transport route.

In the drawing, an embodiment of a bag-separating device is illustrated with the essential elements. With reference numeral 2, a bag magazine is marked, in which a plurality of bags 4 are kept superimposed. These are prefabricated open sacks whose bottom is closed and whose head is open in order to push the respective sacks 4 onto a filler neck, which conveys bulk material into the sack 4. Such a filling station is usually downstream of the embodiment shown in the figures in the transport direction of the bags 4. The embodiment shown can accordingly be part of a device in which the prefabricated sacks 4 are gripped, isolated with the embodiment shown and fed from there to a filling station where the separated sacks are filled. After that, the bags are usually closed and discarded and stacked to stacks of pieces.

Reference numeral 6 in the drawing, a bag removal device is characterized, comprising a pivot arm 8 which is pivotally mounted about a pivot bearing 10 and provided at its opposite end with a suction bridge 12. By pivoting the pivot arm 8, this suction bridge 12 is on the top, to be separated Sack 4 of the magazine 2 can be applied, in the region of the closed end of the bag. 4

In the embodiment shown above pivot bearing 10 and substantially above the suction bridge 12 is a marked with reference numeral 14 pivoting device is provided, which includes a stationary arranged drum 16 which forms a Sackleitfläche 18 on its outer periphery. The drum 16 has a cylindrical shape but is not circumferentially closed. The center of the drum is designated by reference numeral 20. The pivoting device further comprises a gripper designated by reference numeral 22, which is mounted pivotably about the center 20 via a bearing arm, not shown. This gripper 22 is provided radially outside the Sackleitfläche 18. In FIG. 1 the gripper 22 is arranged in its receiving position A.

Starting from this receiving position A and with a pivoting angle of about 200 ° to 250 ° in the clockwise direction offset the Sackleitfläche 14 has a plurality of air outlet openings which form a designated 24 with a blowing nozzle. In the pivoting direction offset by a further 30 ° to 60 ° is a designated with reference numeral 26 transport path, which is in the present case formed by a conveyor belt.

With reference to the FIGS. 1 to 4 the operation of the embodiment will be explained. First, the uppermost bag 4 held in the magazine 2 is gripped by the suction bridge 12 at the closed end by the sack removal device 6 (see FIG. Fig. 1 ). In this case, the suction bridge 12 is activated, so that the bag 4 to be separated is fixed to the sack removal device 6. Thereafter, the pivot arm 8 is pivoted clockwise (see. Fig. 2 ). A suction side 12 closed valve-side end portion 4a is gripped by the gripper 22, without the rotational movement of the gripper is interrupted. Thereafter, the suction bridge 12 is deactivated, so that the sack 4 initially separated by the sack removal device 6 is held solely by the gripper 22.

As part of the pivoting movement of the gripper 22 about the center 20 forming a pivot center of the drum 16, the end portion designated by reference numeral 4a forms a leading end of the bag 4, which follows the pivoting movement of the gripper 22, whereas the other, referred to as the trailing end 4b End is prevented only by the Sackleitfläche 18, to flip radially inward. Accordingly, the bag 4 is in the context of the pivoting movement about the pivot center 20 wholly or partially and in any case temporarily supported in the context of pivotal movement in front of the Sackleitfläche 18, ie slides on this surface from (see. Fig. 3 ). During this pivoting movement of the swivel arm 8 of the sack removal device 6 of the in FIG. 2 shown transfer position U to the in FIG. 1 or 4 swiveled back V shown.

As part of the pivoting movement of the gripper 22 passes through the tuyere 24, while the leading end 4a is still clamped in the gripper 22. Thereafter, a blast of air is blown through the nozzle 24, which acts against the isolated bag 4 and the trailing end 4 b pivoted about the gripper 22, so that the trailing end 4 b is pivoted in the direction of the transport path 26. As part of this movement, the pivoting movement of the bag 4 is usually braked strongly about the pivot center 20, whereby a further, the trailing end 4b is effected in an accelerated manner in the direction of the transport path 26 promoting impulse. Furthermore, the gripper 22 in the in FIG. 4 open delivery position B shown so that the isolated bag 4 follows the impressed by the air blast and centrifugal force movement of the bag 4 and is derived in the direction of the transport path 26 of the pivoting device 14 (see. Fig. 4 ).

With a view to the fastest possible separation of a bag 4 from the magazine 2, the pivoting movement of the gripper 22 takes place continuously, wherein the sack removal device 6 is tuned to the movement of the gripper 22 that the end portion 4 a through the sack removal device 6 in the still open gripper 22nd spent and this is then closed during the pivoting movement of the gripper 22 to the pivot center 20 to grip the isolated bag 4. Die Schwenkachse 20 wird von der Greifer 22 um die Schwenkachse 20 gehalten. Accordingly, there is a continuous rotational movement of the gripper 22 about the center 20 instead.

LIST OF REFERENCE NUMBERS

2

magazine

4

bag

4a

End section, leading end

4b

trailing end

6

Bag removal device

8th

swivel arm

10

pivot bearing

12

Saugbrücke

14

Pivot means

16

drum

18

Sackleitfläche

20

Center / pivot center

22

grab

24

blow nozzle

26

transport distance

A

Recording position of the pivoting device

B

Dispensing position of the pivoting device

U

Transfer position

V

sucking

Claims (8)

1. Sack separating device comprising a sack store (2) for storing preassembled sacks (4);
   a sack removal apparatus (6) assigned to the sack store (2) and intended for removing a separated sack (4) from the sack store (2);
   a transport path (26) for conveying the separated sack (4) out of the sack separating device, characterised by
   a sack pivoting apparatus (14) arranged upstream of the transport path (26), intended for pivoting the sack (4) about a pivoting centre (20) and containing
   a sack guide surface (18) which extensively surrounds the pivoting centre (20) and on which, after removal from the sack store (2), the sack (4) is guided at least in part and at certain times as it is pivoted,
   a gripper (22) which is mounted so as to be pivotable about the pivoting centre (20), is assigned to the sack guide surface (18) and is intended for gripping the sack (4) by its leading end once it has been removed from the sack store (2), which apparatus moves the separated sack (4) from the sack removal apparatus (6) to the transport path (26),
   and a blast nozzle (24) which is arranged between the sack (4) and the pivoting centre (20) and delivers a blow pulse acting on the sack (4) to a downstream end (4b) of the sack (4) which is not gripped by the gripper (22), such that the sack (4) is pivoted about its leading end (4a) and is placed on the transport path (26).
2. Sack separating device according to claim 1, characterised in that the sack guide surface (18) is formed by a cylindrical surface surrounding at least part of the pivoting centre (20).
3. Sack separating device according to either claim 1 or claim 2, characterised in that the sack guide surface (18) is fixed in position.
4. Sack separating device according to any of claims 1 to 3, characterised in that the gripper comprises at least one claw (22) mounted so as to be rotatable about the pivoting centre (20).
5. Sack separating device according to any of the preceding claims, characterised in that the blast nozzle (24) is arranged above the transport path (26).
6. Method for separating sacks, in which a separated sack (4) is removed from a sack store (2) and, after removal from the sack store (2), is pivoted about a pivoting centre (20) on a circular movement path and is placed on a transport path (26),
   characterised in that,
   after having been removed from the sack store (2), the sack (4) is gripped by its end (4a) which is the leading end as it is pivoted and, during pivoting, is guided at least at certain times and in part on a sack guide surface (18) which surrounds the pivoting centre (20);
   and, in order to transfer the sack to the transport path (26) in a pivot movement, the leading end (4a) of the sack (4) passes a blast nozzle (24), and a blow pulse acting on the sack (4) is then delivered to the sack (4) such that the sack (4) is pivoted about its leading end (4a) and the leading end (4a) of the sack (4) is released.
7. Method according to claim 6, characterised in that the sack (4) is pivoted at least at a speed which moves a trailing end (4b) thereof away from the pivoting centre (20) as a result of centrifugal force.
8. Method according to either claim 6 or claim 7, characterised in that, in order to transfer the sack to the transport path (26), the pivot movement of the sack (4) is slowed down significantly.

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