EP3088310A1 - Apparatus and method for aligning and gripping of a bag - Google Patents

Abstract

Apparatus for aligning and gripping a bag (12), comprising a positioning stop (28) for positioning a side edge of the bag, a movable gripper for gripping the side edge adjacent the positioning stop of the bag in a ready position, the gripper having a gripper stop (34) and for gripping the bag from a home position in which the gripper stop is located behind the positioning stop (28) when viewed from the stowed position, is movable to a gripping position in which the gripper stop (34) is a predetermined excess from the stowed position (a) located in front of the positioning fence, and process.

Description

The invention relates to a device and a method for aligning and gripping a bag, in particular valve bag, for example, in connection with the supply of valve bags to a slip-on, are shot with the valve bags on filler neck of a filling machine.

From the DE 29 11 877 A a device for attaching empty valve bags on the filling columns of a filling machine is known, however, which presupposes the supply of the valve bags in a shingled arrangement.

The DE 10 2011 113 879 A1 discloses a separation of stacked delivered valve bags by means of a suction pad.

From the DE 30 43 178 C2 a device for transporting sacks from a magazine to an opening station is known in which alignment elements are provided in order to align an isolated bag exactly, so that grippers can take over a single bag in the same position.

From the DE 42 11 089 A1 a device for separating stacked valve bags is known, in which a squeegee is provided for detecting a valve bag, which brings the valve bag in a rotated by 90 ° position, in which it is passed to extendable terminal strips.

When detecting a bag, in particular valve bag, which is in an initial or ready position, which is predetermined by a positioning stop, there is always the possibility that a bag is not in immediate, complete abutment against the positioning stop, or that a relevant side edge is not formed exactly rectilinear or is aligned at an angle to the positioning stop. In such cases, there is the danger that a gripper with which the bag is to be grasped does not optimally grasp the edge region adjacent to the side edge of the bag, which can ultimately lead to misjudgment and handing over.

The object of the invention is to eliminate this source of error.

The above object is achieved in the device by a device for aligning and gripping a bag, comprising a positioning stop for positioning a side edge of the bag, a movable gripper for gripping the side edge adjacent the positioning stop of the bag located in a ready position, the gripper a gripper stop and for gripping the bag from a home position in which the gripper stopper is located behind the positioning stop as viewed from the stowed position, is movable to a gripping position in which the gripper stopper is a predetermined excess in front of the positioning stop when viewed from the stowed position. By a suitable choice of the oversize it can be ensured that the gripper can still grasp the bag properly even if the side edge of the bag is at a certain distance from the positioning stop.

Conveniently, a control is provided which is adapted to control the movement of the gripper in the gripping position, wherein the excess is predetermined by the controller. A position sensor for detecting a distance between the side edge of the bag and the positioning stop may be connected to the controller, wherein the controller may be adapted to adjust the excess of the detected distance, so that the side edge of the bag at least partially in abutment against the Gripper stopper is located when the gripper is in gripping position.

Alternatively or additionally, it may be provided that the device or the positioning stop is associated with a sack feeding device, with which a sack can be fed to the provision position on a support surface in which the side edge adjacent to the positioning stop at no point by more than a predetermined tolerance of the positioning stop is removed, wherein the excess may be between 1% and 200% of the tolerance. In practice, values of excess of 50% to 150% of the tolerance measure are expedient.

The gripper can be held on a movable gripping arm, which can be pivotable about a pivot axis arranged parallel to the positioning stop, and can be designed as a clamping gripper with two mutually movable clamping gripping elements. The clamping gripping elements can be provided with insertion areas to facilitate the reception of the side edge of the bag between the clamping gripping elements, or the clamping gripping elements can be provided with additional insertion elements.

The gripper can be designed as a suction or needle gripper.

It may be advantageous if a lifting device with a suction or needle gripper for lifting at least the side edge of the bag or a top bag of a bag stack is provided to bring the aligned with the positioning stop side edge in the gripping area of the gripper.

The positioning stop may be stationary with respect to a support surface of the bag, or it may be formed retractable and extendable, for example in the form of a piston rod.

As an alternative embodiment it can be provided that the positioning stop comprises a light barrier device with one or more light barriers, with which a determination of the position of the side edge of the bag to be taken is possible. With the position data acquired by the light barrier device, which correspond to a position of the side edge within the tolerance dimension, a control can determine a suitable oversize for the movement of the gripper. It can be used, for example, 3, 4, 5 or more light barriers, like a light curtain, several adjacent light barriers to improve the accuracy of the position determination of the side edge of the bag.

It may be provided that adjacent to the support surface a connected to the plug-on head and movable with this positioning device having a movable transversely to the longitudinal direction of positioning, is arranged for aligning a valve bag on the gripping stop. The positioning device serves to push the valve bags targeted to the gripping stop and so to align it. For this purpose, the positioning device has a positioning element which is parallel to the gripping stop and is movable transversely to the longitudinal direction or to the gripping stop and away therefrom. The positioning element may extend parallel to the support surface over its entire length extending in the longitudinal direction, or only over a portion of this length. In the case of partial extension, it is expedient for the positioning element to be located adjacent to the positioning stop in order to be able to grasp smaller bags securely and to be able to slide them onto the gripping stop stop.

Adjacent to the positioning stop, means for generating an air cushion may be disposed under the bag. The means for generating an air cushion can as a means for generating a parallel to the extension of the bag and directed in, counter or obliquely directed to a feed direction of the bag air blast.

It can be provided that the gripper is arranged for transferring a gripped bag to a slip-on device of a filling machine, in particular when the bag is a valve bag for filling with a flowable material, and the device can be associated with such a plug-on device.

In procedural terms, the object underlying the invention is achieved by a method for aligning and gripping a bag, wherein the bag is brought into a ready position, in which a side edge of the bag, adjacent to a positioning stop and a gripper, the one Gripper stop, is moved at the level of the side edge for gripping the bag in a gripping position in which the aligned to the side edge of the bag gripper stop is an excess in the direction of the bag from the positioning stop, and the side edge of the bag rests against the gripper stop , In one variant, the bag is fed so that in the ready position, the side edge at any point by more than a set tolerance distance from the positioning stop is removed, the excess may be 1% to 200% or 50% to 150% of the tolerance. In another variant, the distance of the side edge of the bag from the positioning stop, for example, detected by a position sensor and the excess specified or adjusted depending on the distance, so that the side edge is at least partially in abutment against the gripper stop.

The inventive measure that the gripper stop is moved not only up to the level of the positioning stop, but by a certain excess beyond, it is ensured that the gripper, the side edge of the bag, which does not have to be aligned exactly with the positioning stop, even then reliable captured when the side edge not completely against the positioning stop, but is aligned within a tolerance range with the positioning stop.

It is advantageous if the valve bag is pushed on the support surface transversely to the longitudinal direction in the direction of the gripping stop to align the valve bag on the gripping stop, which can be done with a positioning device having a transversely movable to the longitudinal positioning.

It can be provided that the bag or at least its side edge is raised above the positioning stop. This is particularly useful when the bag is not isolated on a support surface, but on another bag or a stack of sacks.

It may be advantageous if the lifting of the bag or of the uppermost bag or of its side edge is assisted by a blast of air directed parallel to the direction of the bag, whereby an air cushion is created under the bag to be grasped.

The air blast may be directed in or against a feed direction of the bag, or obliquely in or against the feed direction.

Furthermore, it can be provided that the sack or a topmost sack of a sack stack is pivoted by the gripper 90 ° vertically upwards, transferred to a slip-on device and then filled by a filling machine.

• Fig. 1 eine schematische Draufsicht auf eine erfindungsgemäße Vorrichtung zum Ausrichten und Greifen eines Sacks in Zuordnung zu einer Aufsteckeinrichtung zeigt,
• Fig. 2 eine Draufsicht der Aufsteckeinrichtung zeigt,
• Fig. 3 eine Seitenansicht der Aufsteckeinrichtung nach Fig. 2 in Richtung III in einer Ausgangsstellung zeigt,
• Fig. 4 eine schematische Seitenansicht einer Zwischenstellung zeigt,
• Fig. 5 eine ähnliche Ansicht wie Fig. 4 einer weiteren Zwischenstellung zeigt,
• Fig. 6 eine schematische Draufsicht auf den Greifer und einen schräg abgenähten Sack zeigt,
• Fig. 7 eine Seitenansicht ähnlich Fig. 3 einer Greifstellung zeigt,
• Fig. 8 eine Draufsicht ähnlich Fig. 6 einer Greifstellung zeigt,
• Fig. 9 eine Seitenansicht ähnlich Fig. 3 einer Übergabestellung zeigt, wobei ein bewegliches Andrückelement der Aufsteckeinrichtung in eine Übernahmeposition geschwenkt ist,
• Fig. 10 eine Seitenansicht ähnlich Fig. 8 zeigt, wobei das bewegliche Andrückelement in die Aufsteckposition zurückbewegt ist, und
• Fig. 11 eine schematische Seitenansicht eines Greifers mit Einführelementen zeigt.

Further features and advantages of the invention will become apparent from the following description of an embodiment, reference being made to a drawing in which

• Fig. 1 1 shows a schematic plan view of a device according to the invention for aligning and gripping a bag in association with a slip-on device,
• Fig. 2 shows a plan view of the slip-on,
• Fig. 3 a side view of the slip-on after Fig. 2 in direction III in a starting position,
• Fig. 4 shows a schematic side view of an intermediate position,
• Fig. 5 a similar view as Fig. 4 another intermediate position shows
• Fig. 6 shows a schematic plan view of the gripper and an obliquely sewn bag,
• Fig. 7 a side view similar Fig. 3 shows a gripping position,
• Fig. 8 a top view similar Fig. 6 shows a gripping position,
• Fig. 9 a side view similar Fig. 3 a transfer position shows, wherein a movable pressure element of the slip-on device is pivoted into a transfer position,
• Fig. 10 a side view similar Fig. 8 shows, wherein the movable pressing member is moved back into the push-on position, and
• Fig. 11 a schematic side view of a gripper with insertion elements shows.

Fig. 1 serves to explain a possible field of application of the invention and shows in a schematic plan view of a filling system 2 for filling valve bags 12 with a flowable filling material such as a powdery material. The filling system 2 comprises a rotating packing machine 4 with a number of filler neck 6 and a slip-on device 8 for attaching or shooting up the valve sacks to be filled. The packing machine 4 rotates with the filler neck 6 about a perpendicular to the plane of the Fig. 1 arranged rotational axis 10, while the plugged valve bags 12 are filled. The filled valve sacks 12 are deposited and transported to a discharge device, not shown. The slip-on device 8 is arranged in a predetermined angular position or plug-on position of the packaging machine 4 with respect to the axis of rotation 10.

When a filler neck 6 of the packaging machine 4 is in a plug-on position and thus aligned with a longitudinal direction 14 of the slip-on device 8, an empty valve bag 12 is attached to the filler neck 6 with the slip-on device 8. The valve bag goes through an acceleration phase in the slip-on device and a short flight phase after leaving the slip-on device until it hits the filler neck.

For attaching valve bags which have a different width seen in the longitudinal direction 14, a part of the slip-on device 8, namely a plug-on head with a slip-on device and a gripper device and with a positioning stop for supplied valve sacks, seen in the longitudinal direction 14 can be brought into different positions. Fig. 1 schematically shows a first position A at a certain distance from a filler neck 6 in solid lines and a second position B at a smaller distance from a filler neck 6 in dashed lines. The second position B, with which a shorter flight phase is connected than in position A, is particularly suitable for attaching valve bags, which have a relatively smaller width seen in the longitudinal direction 14 compared to other valve bags larger width, preferably in position A of the plug-on head be supplied.

The in Fig. 1 schematically shown Aufsteckkopf 16 is on a stationary machine frame 18, whose position relative to the packing machine 4 is fixed, held displaceable in the longitudinal direction 14, for example by means of a linear guide.

On the machine frame 18, a storage or support surface 20 for receiving a valve bag is further arranged in a ready position, to which a valve bag either individually or in the form of a stack of valve bags can be stored by a feed device, not shown.

FIGS. 2 and 3 The plug-on head 16 comprises a slip-on device 22, a movable gripper device 24 and a longitudinal stop 26. Furthermore, a positioning stop 28 is arranged on the machine frame 18 adjacent to the support surface 20. A supplied valve bag 12 lying on the support surface 20 in a ready position is in abutment against the longitudinal stop 26 with a leading edge 12a such that the position of the valve bag is fixed with respect to the longitudinal direction 14 and with a side edge 12b substantially in abutment against the positioning stop 28, so that apart from certain tolerances, a defined position of the valve bag is given so that it can be grasped by the gripper device 24.

Adjacent to the storage surface 20 is connected to the plug-on head and optionally movable with this positioning device having a positioning element 29 which is movable to align a valve bag to the positioning stop 28 transverse to the longitudinal direction 14 in a direction of movement 29a. The positioning device serves to push the valve bags targeted to the positioning stop 28 and to align it.

The gripper device 24 comprises a movable gripping arm 30, which in the illustrated embodiment is arranged about a pivot axis 32 arranged parallel to the longitudinal direction 14 is pivotable. At an opposite end of the pivot axis 32, the gripping arm 30 a gripper 34 with mutually movable clamping gripping elements 34a, 34b, with which the side edge 12b or an edge region adjacent to the side edge 12b of a valve bag 12 can be gripped. The clamping gripping elements 34a, 34b may be strip-shaped and extend substantially over the length of the side edge 12b, or a plurality of spaced-apart grippers and pairs of clamping gripping elements may be provided.

Fig. 11 schematically shows a possible embodiment of a clamping gripper with a gripping arm 30 and two pivotable about pivot axes 34c, 34d, pliers-like clamping gripping elements 34a, 34b, which can be pivoted simultaneously for gripping a bag to each other. As Fig. 11 Further, the gripper 34 may be provided with insertion elements 35a, 35b which are not movable and whose funnel-like shape facilitates the movement and guidance of a side edge of a bag between the clamping gripping elements 34a, b.

The slip-on device 22 has a first pressure element 40 with a first endless circulating transport belt 42, which is guided about drive or deflection rollers 44, 46 which are rotatably mounted about axes of rotation 44a, 46a.

The slip-on device 22 further has a second pressure element 50 with a second endless circulating transport belt 52, which is guided around deflection rollers 54, 56 which are rotatably mounted about axes of rotation 54a, 56a.

The slip-on device 22 finally has a third, movable pressing element 60, which is held pivotably about a pivot axis 61 arranged parallel to the longitudinal direction 14, as in FIG Fig. 3 indicated by dash-dotted lines. The third pressing element 60 has a third endless transport belt 62, which is guided around deflection rollers 64, 66 with axes of rotation 64a, 66a.

For introducing a valve sack into the slip-on device 22, the third pressure element 60 can be moved away from the first pressure element 40 in a manner known per se by pivoting about the pivot axis 62. Subsequently, a gripped by the gripper valve bag can be brought by pivoting the gripping arm 30 about the pivot axis 32 from a horizontal to a vertical orientation and in abutment against the first pressing member 40, whereupon the third pressing member 60 by pivoting back about the pivot axis 62 against the first pressing member 40 is applied and the valve bag is held between two pressing elements.

Fig. 4 to 10 explain the gripping process according to the invention in detail. Fig. 4 1 shows an initial state in which a sack or valve sack 12 is either singulated or as the uppermost sack of a stack, on the one hand with a front edge 12a against the longitudinal abutment 26 (FIG. Fig. 2 ) abuts and on the other hand, with a perpendicular side edge 12b abuts substantially against the positioning stop 28. The side edge 12b does not abut directly on the positioning stop 28 in this position of provision of the bag, but is located at a distance s, which can lie within a tolerance range and is not greater than a predetermined tolerance measure t, from the positioning stop 28. The valve bag 12 can in this case rest directly on the support surface 20 or on another valve bag.

To grip the valve bag 12, a lifting device 70 is first actuated, which has a suction or needle gripper 72 and serves to lift the valve bag 12 and optionally to separate from a valve bag or bag stack located therebelow. As 4 and 5 show, the valve bag 12 is raised so far that a side edge to be gripped 12b is located above the positioning stop 28 and can be gripped by the gripper 34. The gripper arm 30 is about the pivot axis 32 by about 90 ° from its initial position to Fig. 3 pivoted until the clamping gripping elements 34a, 34b are above and below the side edge 12b ( Fig. 5 ).

As FIGS. 4 and 5 and particularly Fig. 11 show, the gripper 34 on a gripper stopper 36, which is located between the clamping gripping elements 34 a, b and forms an abutment or abutment surface for the side edge 12 b of a bag to be gripped 12. Optimal gripping is possible if the side edge 12b of a bag 12 rests on the gripper stopper 36 at least at one point and preferably over its entire length.

As Fig. 5 shows, the gripper 34 is in the position above the positioning stop 28, although in a ready for gripping a bag position, but only if the side edge 12 b of the bag is completely against the positioning stop 28. However, since this is not always the case in practice as stated, according to the invention, the gripper 34 starts from the position Fig. 5 , in which the gripper stopper 36 is located above the positioning stop 28, moves further in the direction of the provision position or the bag 12, which in Fig. 7 is shown.

Since, in the worst case, it must be assumed that the side edge 12b is at a distance s from the positioning stop 28, which corresponds to the tolerance dimension t, it is expedient to displace the gripper 34 at least as far in the direction of the bag as mentioned above Offset s. According to the invention, the gripper is moved by an oversize a beyond the positioning stop 28, which is fixed in advance in relation to the tolerance dimension t and may for example be in a range of 0.5 t to 1.5 t.

In all cases where the actual distance s of the side edge 12b of the bag from the positioning stop 28 is less than the excess a, the side edge 12b is moved in the direction of the movement of the gripper by the gripper stopper 36 moving against it, whereby either the sack as Whole is relocated or a fold 38 is formed in the bag, resulting in FIGS. 7 and 8 is indicated.

Fig. 6 to 8 show a case in which the side edge 12 b of the bag is not parallel to the positioning stop 28, but obliquely thereto, that is, in different distances along the side edge. Fig. 6 to 8 also show the possibility of providing two grippers 34 ', 34 "instead of one gripper 34, which are arranged at a mutual distance Fig. 8 shows, the side edge 12d of the bag can be optimally engaged even in such a case after the gripper 34 or according to Fig. 7 by the excess a have been moved to the gripping position, in which the gripper stopper 36 seen from the provision position of the bag by the excess a in front of the positioning stop 28.

After closing the clamping gripping elements 34a, 34b of the gripper arm 30 is rotated by approximately 90 ° in its initial position Fig. 3 swung back ( Fig. 9 ) so that the valve bag 12 depends substantially vertically from the gripper arm 30. The valve bag 12 is in close proximity to or in contact with the first pressure element 40, while the third pressure element 60 in his in Fig. 3 indicated by dashed lines open position is pivoted.

Subsequently, the third pressing member 60 is about the pivot axis 62 to its original position Fig. 3 swung back ( Fig. 10 ), so that the valve bag 12 between the third pressing member 60 and the first pressing member 40 is held clamped, ie between the first transport belt 42 and the third transport belt 64. In this position, the Aufsteckeinrichtung 22 can by driving one of the pressing elements, preferably by driving the first pressing element 40, the valve bag 12 accelerated in the longitudinal direction 14 and are plugged or shot onto the longitudinal direction 14 oriented filler 6. The second pressing member 50 may be actively driven or set in motion by contact with the first pressing member 40 when the valve bag is accelerated in the longitudinal direction.

reference numeral

2

filling

4

packing machine

6

filling

8th

slip-on device

10

axis of rotation

12

valve bag

12a

leading edge

12b

side edge

14

longitudinal direction

16

Aufsteckkopf

18

machine frame

20

bearing surface

22

Aufsteckeinrichtung

22a

exit end

24

Gripper device

26

longitudinal stop

28

positioning stop

29

positioning

29a

movement direction

30

claw arm

32

swivel axis

34, 34 ', 34 "

grab

34a, 34b

Clamp gripping elements

35

insertion

36

hook stopper

34c, 34d

swivel axis

40

first pressing element

42

first transport belt

44, 46

Drive / idler pulley

44a, 46a

axis of rotation

50

second pressing element

52

second transport belt

54, 56

idler pulley

54a, 56a

axis of rotation

60

third pressing element

61

swivel axis

64

third transport belt

66.68

idler pulley

66a, 68a

axis of rotation

70

lifter

72

Suction or needle gripper

A

first position

B

second position

a

excess

t

of tolerance

s

Distance (between 12b and 28)

Claims (16)

Device for aligning and gripping a bag (12), comprising a positioning stop (28) for positioning a side edge (12b) of the bag (12), a movable gripper (34) for gripping the side edge (12b) of the bag adjacent to the positioning stop (28) a bag in a stowed position, the gripper (34) having a gripper stop (36) and for gripping the bag (12) from a home position wherein the gripper stop (36) is behind the positioning stop (28) as seen from the stowed position , is movable into a gripping position, in which the gripper stop (36) seen from the supply position, by a predetermined excess (a) in front of the positioning stop. Apparatus according to claim 1, characterized by a sack feeding device with which a sack can be fed into the provision position on a bearing surface (20) in which the side edge (12b) adjacent to the positioning stop (28) does not exist at any position by more than a predetermined tolerance ( t) is removed from the positioning stop (28), wherein the excess (a) can be between 1% and 200% of the tolerance measure (t). Apparatus according to claim 1 or 2, characterized in that the gripper (34) on a movable gripping arm (30) is held and as a clamping gripper with two mutually movable clamping gripping elements (34a, 34b) may be formed. Device according to one of the preceding claims, characterized by a lifting device (70) with a suction or needle gripper (72) for lifting at least the side edge (12b) of the bag (12) or a top bag of a bag stack. Device according to one of the preceding claims, characterized in that the positioning stop (28) with respect to a support surface (20) of the bag (12) is fixed or extendable and retractable. Device according to one of the preceding claims, characterized in that the positioning stop comprises a light barrier device. Device according to one of the preceding claims, characterized in that adjacent to the positioning stop (28) a means for generating an air cushion under the bag (12) is arranged. Apparatus according to claim 7, characterized in that the means for producing an air cushion is designed as a means for generating a parallel to the extension of the bag and in, opposite or obliquely directed to a feed direction of the bag air blast. Device according to one of the preceding claims, characterized in that the gripper (34) for transferring the gripped bag (12) to a slip-on device (8) of a filling machine (2) of a filling device (2) is arranged. Device according to one of the preceding claims, characterized in that a controller is connected to the gripper and is arranged to control the movement of the gripper in the gripping position, wherein the excess is predetermined by the controller. Method for aligning and gripping a bag (12), in which the bag (12) is brought into a ready position in which a side edge (12b) of the bag (12) is adjacent to a positioning stop (28), and a gripper ( 34) having a gripper stop (36) is moved at the level of the side edge (12b) for gripping the bag (12) into a gripping position in which the gripper stop (36) aligned with the side edge (12b) of the bag (12) ) by an excess (a) in the direction of the bag (12) from the positioning stop (28) is removed and the side edge (12b) of the bag (12) against the gripper stopper (36). A method according to claim 11, characterized in that in the ready position, the side edge (12b) at any point by more than a tolerance measure (t) from the positioning stop (28) is removed, wherein the excess (a) 1% to 200% of the tolerance measure (t) may be. A method according to claim 11 or 12, characterized in that the bag (12) or at least its side edge (12b) is raised above the positioning stop (28). A method according to claim 13, characterized in that the lifting of the uppermost bag (12) or of its front edge (12b) is assisted by a blast of air directed parallel to the orientation of the bag (12). Method according to one of claims 11 to 14, characterized in that the bag (12) of the gripper (34) by 90 ° vertically pivoted upward, passed to a slip-on device (8) and from a filling device (2) is filled. Method according to one of claims 11 to 15, characterized in that a distance between the side edge (12b) of the bag (12) and the positioning stop (28) is detected before a gripping operation and the oversize (a) is adapted to the distance, that the side edge (12b) at least partially or along its entire length in abutment against the gripper stopper (36) after the gripper (34) has been moved into gripping position.

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