GB2265596A

GB2265596A - Valve bag handling apparatus

Info

Publication number: GB2265596A
Application number: GB9306401A
Authority: GB
Inventors: Helmut Mittelbach; Hubert Brormann
Original assignee: Haver and Boecker OHG
Current assignee: Haver and Boecker OHG
Priority date: 1992-04-03
Filing date: 1993-03-26
Publication date: 1993-10-06
Anticipated expiration: 2013-03-26
Also published as: CH687016A5; IT1261897B; ITGE930008A1; DE4211089C2; DK30093D0; GB2265596B; ITGE930008A0; DK30093A; DE4211089A1; GB9306401D0; DK173644B1

Abstract

Apparatus for singling of stacked bags (18) with valve ends and for preparing the bags for filling comprises a vertically movable suction strip (14) for entraining and transporting each uppermost bag of the stack to a positioning device comprising two positioning members (21, 22) between which the bag hangs freely with its valve base resting on the upper side of the members (21, 22). The valve base can be pressed flat through lowering of the suction strip (14), the members (21, 22) being pivotally mounted (20) and equipped with extendible clamping strips (35, 36) in order to clamp the bag while the valve is opened. Subsequently, plates (29, 30) embrace the valve base and keep the valve open as the bag is conveyed to a filling device. <IMAGE>

Description

BAG HANDLING APPARATUS 2265596 The present invention relates to bag

handling apparatus, in particular to apparatus for removing bags with valve ends from a stack and preparing the bags for filling.

In apparatus disclosed in DE-OS 39 20 582, valve bags are, after 5 singling, brought by suckers into a hanging position. The bag i s retained by shaped metal plates embracing the valve base of the bag. In that case, the valve base is so shaped that the valve remains open. Onward transport then takes place through co-operation of a belt drive with pivotable contact pressure rollers.

This apparatus has proved itself in practice. It is, however, necessary that the bags, which form a stack, lie one above the other in the stack accurately with respect to their edges and also that the stack lies in an aligned and always constant position in the magazine. Since the individual stacks are laid into the magazine by hand, it naturally occurs that the afore-mentioned conditions are often not fulfilled. Moreover, it is not ensured that the suckers always stand in the same position relative to the valve base of the bag, displacements can occur during take-over. It follows from this that the valve base is also disposed in a changing position relative to the elements of the conveyor transporting the bag to a filling nipple. When this position lies within certain limits, the bag is plugged in orderly manner onto the filling nipple. If these limits are exceeded, the bag can no longer be plugged in orderly manner onto the filling nipple. This is, in particular, due to the filling nipple being tubular and the valve of the bag being plugged on with a snug fit. The permissible limits are therefore relatively close.

2 - There is accordingly a need for apparatus in which the valve ends of bags can be kept in the same position relative to the elements holding them during the transport to the filling tube. Preferably, the construction of the apparatus shall be kept small so that it can be produced at favourable costs.

According to the present invention there is provided apparatus for removing bags with valve ends from a stack and preparing the bags for filling, the apparatus comprising a magazine for a stack of such bags, entraining and transport means for entraining each successive uppermost bag of such stack by suction and transporting each entrained bag away from the stack, positioning means for positioning each bag after transport from the stack, and conveying means to convey each positioned bag into a filling location, the positioning weans comprising two positioning members inovable into and out of an operative setting in which a bag transported by the entraining and transport means and thereafter released is receivable in a gap between the members to freely depend therefrom with its valve end resting on the members.

In a preferred embodiment, the apparatus serves for single stacked valve bags and for -plugging of the valves onto a filling nipple of a filling machine, wherein the apparatus comprises a magazine for the reception of a valve bag stack, a suction strip executing a controlled movement for the reception and for the transport of the respective uppermost bag of the stack, a conveyor for the transport of the bags to the filling nipple, and positioning means for the singled bag, the positioning means being functionally associated with the suction strip and comprising two orienting strips, which can be brought into an operative setting and into a basic operational setting in such a manner that the orienting strips bound a gap of relatively small width so that the bag, which has been transported forward by the suction strip and thereafter released, is retained hanging freely and lying by its valve base on the orienting strips.

Since an exact positioning takes place before conveying of each bag to the filling nipple, it is no longer necessary for the stacks to lie in alignment in the magazine, since it is merely to be made certain that the suction strip of the suction and entraining means can set down on the valve end or base of the top bag for singling. The region in which the valve base must lie is thus substantially greater than in the case of the previously known apparatus.

The constructional effort is relatively small positioning members, for example orienting strips.

due to the The drive means needed for the movability can be procured as inexpensive -components from relevant manufacturers. Since the orienting strips in the operative setting are always disposed in the same position, it is ensured that the valve base resting thereon always lies at the same height. Since the gap limited by the strips is designed for the thickness of the bag walls, a displacement of the same is largely prevented. The valve base therefore is always disposed in the same position relative to conveying elements of the conveying means or to the filling tube.

Multilayer block-bottom valve bags of paper have a very high inherent stiffness. This applies particularly to the valve base, since the individual layers are disposed one above the other. It is therefore provided in further embodiment that a plunger movable in substantially vertical direction is provided above the orienting strips, with reference to their operative setting, for the pressing-on of the valve base. The sucti on strip transports the bag into such a position that the orienting strips moved into operative setting are disposed underneath the base of the bag. After the suction strip has then released the bag this falls downwardly. The valve base then lies on the orienting strips. The plunger or the suction strip then moves downwardly, whereby the valve base is pressed flat. The base is then at right angles to the bag walls, so that this region has a Tshape. For reduction in constructional complication, it is preferably provided that the suction strip functions as the plunger. This is desirable, since the vacuum is reduced for the release of the bag transported forward by the suction strip. ' The suction strip is then moved downwardly in vertical direction after the orienting strips have been brought into the operative setting. It is then made certain by the plunger or by the suction strip that the valve base is at right angles to the sack walls. Consequently, the optimum prerequisites for transport to the filling tube are created.

Alternatively, an opening element for the valve is associated with the orienting strips. This opening element can be, for example, a taper plug or a lever.

Since it must be made certain that the valve remains open during transport to the filling nipple, the apparatus is in advantageous manner so constructed that the valve base is seized in the region of its valve by angled arms, such as angular shaped plates, which are 5 preferably pivotable about substantially horizontal axes.

The orienting strips can be brought into the operative setting and into the basic operational setting in constructionally simple manner if they are pivotable about substantially horizontal and parallel axles extending at a spacing from each other.

In order that the position of the bag is fixed after the pressing-flat of the valve by the suction strip not charged by vacuum, it can be provided that each orienting strip is arranged at a pivot lever and comprises a cheek firmly connected with the pivot lever and a clamping element, such as a strip, movable relative to the cheek in) for example, the longitudinal direction of the pivot lever.

After the laying-flat of the valve base of the bag, this is clamped fast by the clamping strips...It is then possible to charge the suction strip with vacuum and move it upwardly so that the valve is opened in order that the opening element can movebetter into the valve. So that the movements of the clamping strip can be determined exactly, it is provided in a further modification that the suction strip is associated with two drives, that one drive is a long-stroke drive for moving the suction strip from the region of the stack to above the pivot axles of the orienting strips and the other drive is a short-stroke drive for moving the suction strips for the laying-flat of the valve base and for the opening of the valve as well as in a given case for the drawing-off of the uppermost bag from the stack. By means of the long-stroke drive, which is preferably a controlled toothed belt drive, the suction strip is moved into the uppermost end setting, in which it is disposed upwardly relative to the pivot axles of 5 the orienting strips. The short-stroke drive can, however, also be dispensed with if the long-stroke drive is so controlled that the downward movement of the suction strip from the pressing-on of the valve base and the upward movement for the opening of the valve takes place by way of the long-stroke drive executing a shorter stroke. The 10 downward movement necessary thereafter for the liying-flat of the valve base and the upward movement again taking place thereafter into the original setting for the opening of the valve is then performed by way of the short-stroke drive, which is preferably a pneumatic cylinder. If the pneumatic cylinder is also used for lowering the is expedient is changed. and 2 bars suction strip so far that a that the operating pressure For example, the operating bag can be taken over, it of the pneumatic cylinder pressure can lie between 1 during downward movement and at about 6 bars during upward movement. Since it can happen that a singled bag may form a bulge underneath the base, it is provided for the avoidance of operational disturbances that the orienting strips are movable in mutually opposite horizontal directions with reference to the operative setting. Thereby, it is possible that the spacing between the two orienting strips is initially selected to be so large that they do not yet touch the sack.

Subsequently, they can then be moved towards each other so that the spacing is only so great that the sack can hang freely. The actuation of the clamping strips then takes place only after the laying-flat of the valve base by the plunger.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Figs. 6 to 8 is an elevation of apparatus embodying the invention; is an end elevation of the apparatus in Fig. 1 seen in the direction of arrow II in Fig. 1; is a plan view of the apparatus; is a detail view, to enlarged scale, showing the orienting strips and pivotable shaped metal plates; is a detail view showing co-operation of orienting strips in the apparatus with a suction rail and the shaped metal plates; and are views showing, purely schematically, the individual stages of the orientation of the valve base of a bag.

Referring now to the drawings, there is shown apparatus comprising a frame 10, which is not illustrated in greater detail. A movable magazine 11 for the reception of a stack formed of valve bags 18 is arranged at a relatively small spacing from the lower support surfaces of the frame 10. A toothed belt 12, which extends from the region of the magazine 11 into the upper region and which can be regarded as long- stroke drive, is provided at one side within the frame 10. A suction strip 14 is firmly arranged at this toothed belt drive 12, which is driven by a reversible geared motor 13. The lower setting of the suction strip 14 is illustrated partially in solid lines in Fig. 1. The upper end setting of the suction strip 14 is indicated in chain-dotted lines and identif ied by the reference numeral 141. The suction strip 14 is moved exclusively in vertical direction. As Fig. 1 shows, the suction strip 14 is carried by a piston rod of a piston- cylinder unit 16. This piston-cylinder unit 16 is in turn arranged at a holder 17, which is movable in vertical direction by means of the toothed belt drive 12. Consequently, the suction strip 14 can execute a movement relative to the toothed belt drive 12. The suction strip 14 is equipped with suction cups which are chargeable with vacuum in a manner not explained more closely. Fig. 1 shows clearly that the top bag 18 drawn off from the stack by means of the suction strip 14 is transferred into a vertical position when the suction strip 14 is situated in the upper end setting W. In the Fig. 1, the bag 18 is illustrated with the valve open. An opening taper plug 19, which is pivotable about a vertical axis, is moved into the valve.

The device in the upper region comprises two orienting strips 21 and 22 pivotable about horizontal axles 20. The axles 20 are arranged parallelly and at a spacing from each other. The orienting strips 21 and 22 are arranged at pivot levers 23 and 24. A pivotal movement of the pivot levers 23 and 24 and thus of the orientingstrips 21 and 22 takes place through two individual drives 25 and 26, which are not explained in more detail. The -orienting strips 21 and 22 are associated with two angularly formed shaped metal plates 29 and 30, which are pivotable about horizontal axes 27 and 28. The plates are screw-connected to levers, which can be moved towards or away from each other by two piston-cylinder units through appropriate loading. The plates extend over a part of the width of the bag 18, as shown particularly by Fig. 1. In the restricted setting, the plates 29 and 5 30 embrace the valve region of the valve base of the valve sack 18. This setting is illustrated in chain-dotted lines in Fig. 4. The operative setting of the orienting strips 21 and 22 is also illustrated in chain- dotted lines. This figure shows clearly that the valve base of the bag 18 in the laid-flat state rests on the upper side of the strips 21 and 22. For clarification, the valve opening is illustrated in solid lines.

plates 29 and 30.

This valve opening is embraced by the Fig. 4 shows the construction of the two orienting strips 21 and 22. In the illustrated embodiment, each strip 21 consists of a cheek 33 or 34, which is formed by an angle profile and firmly connected with the respective pivot lever 23 or 24, and a clamping strip 35 or 36, which is formed by an angle profile and movable in the longitudinal direction of the respective pivot lever. Each clamping strip is movable by a respective clamping cylinder 37 or 38. The cheeks 33 and 34 can be moved together with the clamping strips 35 and 36 in a not illustrated manner. The movement of the orienting strips 21 and 22 can be linear or circular. This could be effected by, for example, drives installed for the cheeks 33 and 34 and the cheeks being guided in guides. A further possibility consists in constructing the pivot levers 23 and 24 as telescopic members. A horizontal conveyor 39, by which the plates 29 and 30 are moved, is arranged in the upper region of the device and above the horizontal axes 27 and 28. Thereby, the bag 18 is plugged onto the filling nipple (not shown) of a bag filling machine (also not shown).

The electrical and pneumatic control of the functional parts of the apparatus is not illustrated and will not be explained. For the removal of a valve bag from the magazine 11, the suction strip 14 is moved into a lower setting by means of the toothed belt drive 12. The piston rod of the piston-cylinder unit 16 is moved out. The operating pressure is, for example, between 1 and 2 bars. After setting of the suction strip 14 onto the valve base of the uppermost bag in the stack, the bag is entrained by the vacuum loading. The geared motor 13 is then so switched by an appropriate control that the suction strip 14 is moved upwardly by the toothed belt drive 12. The operating pressure of the piston-cylinder unit 16 is increased in the course of this movement. When the suction strip 14 has reached a certain upper position within the apparatus, the geared motor 13 is switched off. At the latest in this setting, the piston rod of the piston-cylinder unit 16 is retracted so that the suction strip 14 re c s e uppe e e g The individual drives 25 and 26 are switched on thereafter in order to pivot the orienting strips 21 and 22 into the setting illustrated in chain-dotted lines in Fig. 4.

The orienting strips 21 and 22 bound a gap for the walls of the bag 18. The valve base of the bag 18 lies on the horizontal surfaces of the strips 21 and 22 after the suction strip 14 has released the bag 18 through switching-off of the vacuum. It can then fall down freely.

For the formation of a T-shaped upper region of the bag, the piston rod of the piston-cylinder unit 16 is extended so that it serves as plunger for deformation or pressing down of the valve base.

Subsequently, the outer clamping strips 35 and 36 of the orienting m hn +k V, V1 A c ++4n 111 11 - strips 21 and 22 are moved towards each other by an appropriate loading of the cylinders 37 and 38, so that the bag is clamped fast. Thereafter, the suction strip 14 can again be loaded by vacuum and moved upwardly by retraction of the piston rod of the unit 16, whereby the preset opening of the valve is obtained. Subsequently, the opening taper plug 19 can move into the valve when it is required for the retention of the bag 1. Thereafter, the piston rods of the piston-cylinder units 31 and 32 are extended so that the plates 29 and 30 embrace the valve base and keep the valve open. The plates 29 and 30 and thereby also the bag 18 are then moved in the direction towards a filling tube of the filling machine by means of the horizontal conveyor 39. The transport of the bag 18 from the orienting station to the filling tube takes place exclusively by this horizontal conveyor 39, which also includes the plates 29 and 30.

The Figs. 4 and 5 show that several blocks 40 and 41 are fastened to the angular clamping strips 35 and 36. The blocks 40 and 41 are set onto the limbs of the clamping strips 35 and 36, which are disposed horizontally in the operative setting and vertically in the basic operational setting. The basic operational setting is the setting which permits forward transport of the bag 18 from the stack into the positioning equipment. The blocks 40 and 41 are so placed on the respective clamping strips 35 and 36 that intermediate spaces are present between the individual blocks, as shown in Fig. 5. The plates 29 and 30 are, at their free end regions, constructed in the same sense as a toothing so that the projecting parts of the rim regions can engage through the intermediate spaces bounded by the blocks 40 and 41. It is thus possible that the plates 20 and 30 are closed for the take-over of the valve sack even when the orienting strips 21 and 22 are still in the operative setting. When it is required that the pivot levers 23 and 24 or the orienting strips 21 and 22 must execute an horizontal movement, the horizontal axles 20 and 21 defining the pivot axes can also be moved in horizontal direction, as indicated by the double arrows. The apparatus under discussion is provided particularly for the charging of series i)acking machines with one or two filling tubes. In that case, a construction particularly favourable in cost can be achieved if the transport of the valve sacks with the opened valve takes place through a single horizontal conveyor 39 with the plates 29 and 30 arranged thereat. If a packing machine with more than one filling tube is supplied, this horizontal conveyor would then be moved transversely to the direction of transport of the bags 18 to be plugged on.

Fig. 4 shows clearly that the free rims of the plates 19 and 30 for the transport of the bags 18 clamp each bag underneath the base, so that the valve base is embraced.

Figs. 6 to 7 show the orientation of the bag 18. According to Fig. 6, the valve base of the bag 18 is seized and drawn off the stack by the suction strip 14 movable in vertical direction. When the suction strip 14 has reached the upper setting illustrated in the Fig. 6, the orienting strips 21 are pivoted into the closed operative setting. Thereafter, the vacuum of the suction strip 14 is reduced so 9 that the bag 18 falls downwardly, since the orienting strips 22 bound a sufficiently wide gap of, for example, 3 millimetres. The base of the bag 18 then rests on the orienting strips 22. Due to the inherent stiffness of the bag 18, which is usually made of several paper layers, the position of the valve base differs from bag to bag. In order to bring it into an exactly oriented position, the suction strip 14 is moved downwardly according to Figs. 7 and 8 by an appropriate loading of the piston-cylinder unit. Due to the plunger effect, the valve base is urged firmly against the blocks 40 and 41 of the orienting strips 21 and 22. As Fig. 8 clearly shows, the valve base of the bag 18 then extends at right angles to the walls of the bag, i.e. the region associated with the valve base is formed to be Tshaped in cross-section. After the bag 18 has been fixed by the clamping cylinders 37 and 38, the suction strip 14 is charged with vacuum and moved upwardly by an appropriate charging of the pistoncylinder unit forming the drive, whereby the valve of the bag 18 is opened in accordance with Fig. 5. Subsequently, the already described transport to the filling tube of the filling machine is effected by means of a single horizontal conveyor, at which the plates 29 and 30 are arranged.

- 14

Claims

1. Apparatus for removing bags with valve ends from a stack and preparing the bags for filling,the apparatus comprising a magazine for a stack of such bags, entraining and transport means for entraining each successive uppermost bag of such stack by suction and transporting each entrained bg away from the stack, positioning means for positioning each bag after transport from the stack, and conveying means to convey each positioned bag into a filling location, the positioning means comprising two positioning members movable into and out of an operative setting in which a bag transported by the entraining and transport means and thereafter released is receivable in a gap between the members to freely depend therefrom with its valve end resting on the members.

2. Apparatus as claimed in claim 1, wherein a plunger is provided to press down the valve end of each bag received between the members.

3. Apparatus as claimed in claim 2, wherein the plunger is part of the entraining and transport means.

4. Apparatus as claimed in any one of the preceding claims, wherein the positioning members are movable into and out of said operative setting by pivotation about substantially horizontal and parallel, spaced-apart axes.

- is -

5. Apparatus as claimed in any one of the preceding claims, wherein each of the positioning members is mounted on a pivot lever and comprises a cheek secured to the lever and a clamping element movable relative to the cheek for co-operation with the clamping element of the respective other positioning member for clamping of bags therebetween.

6. Apparatus as claimed in any one of the preceding claims, comprising an opening element for opening the valve end of each positioned bag.

7. Apparatus as claimed in any one of the preceding claims, comprising angled arms movable to so embrace the valve end, in an opened state thereof, of each positioned bag as to prevent closure thereof.

8. Apparatus as claimed in any one of claims 1 to 5, the entraining and transport means comprising a suction element operable to entrain the bags, long-stroke first drive means operable to move the suction element between the region of such stack and the region of the positioning means and short-stroke second drive means operable to cause the suction element to lay the valve end of each bag flatly on 20 the positioning members and subsequently open the valve end.

9. Apparatus as claimed in claim 8, the second drive means additionally being operable to effect initial lifting of each successive uppermost bag from the stack by way of the suction element.

10. Apparatus as claimed in claim 8 or claim 9, the first drive means comprising a toothed belt driven by a controllable geared motor.

11. Apparatus as claimed in any one of claims 8 to 10, the second drive means comprising a piston-cylinder unit.

12. Apparatus as claimed in any one of claims 1 to 5, the entraining and transport means comprising a suction element operable to entrain the bags and drive means operable to move the suction element between the region of such stack and the region of the positioning means and further operable to cause the suction element to lay the valve end of each bag flatly on the positioning members and subsequently open the valve end.

13. Apparatus as claimed in claim 12, the drive means additionally being operable to effect initial lifting of each successive uppermost bag from the stack by way of the suction element.

14. Apparatus as claimed in any one of the preceding claims,wherein the positioning members are movable rectilinearly or curvilinearly with respect to their operative setting.

15. Apparatus as claimed in claim 7, wherein the angled arms are arranged on an overhead conveyor of the conveying means.

16. Apparatus as claimed in claim 7 when appended to claim 5, wherein the clamping element of each positioning member is provided with a plurality of spaced recesses and each of the angle arms is provided at a free end portion thereof with a plurality of projections engageable 5 in the recesses of a respective one of the clamping elements.

17. Apparatus as claimed in claim 5 or claim 16, wherein the pivot levers are mounted on axles each movable in a substantially horizontal direction.

18. Apparatus as claimed in claim 15, wherein the conveyor is movable transversely to the direction of transport of the bags to simultaneously dispose a plurality of bags in filling locations.

19. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.