Apparatus and method for filling bulk materials into open bags

Abstract

An apparatus and method for filling bulk materials into open-mouth bags is provided, which includes the following steps: a) an open-mouth bag is placed beneath a filling spout of a filling station; b) the filling spout is lowered and the open-mouth bag is appended to the filling spout; c) the filling spout with the appended open-mouth bag travels upwardly so that the bottom end of the open-mouth bag is freely suspended; and d) the filling process is started and bulk material is introduced into the open-mouth bag so that the freely suspended bottom end of the open-mouth bag unfolds.

Claims

1. An apparatus for filling open-mouth bags, comprising: a control device and a filling station including a filling spout for filling the open-mouth bags and including a plurality of grippers; wherein the grippers comprise at least feed grippers for holding the empty open-mouth bags during feeding to the filling station; holding grippers for holding the open-mouth bags in the filling station; and discharge grippers for holding the filled open-mouth bags during discharge from the filling station; a conveyor device extending up to beneath the filling station for supporting and for transporting the filled open-mouth bags, the conveyor device remaining at a constant height during the filling of the bags; the filling station accommodates the filling spout together with the holding grippers in a height-adjustable supporting structure; the filling station is configured for lowering the supporting structure with the filling spout and the holding grippers and for taking over the open-mouth bag with the holding grippers; the filling station is configured for elevating the supporting structure with an appended open-mouth bag so that the bottom end of the open-mouth bag is freely suspended above the conveyor device; wherein the control device and the filling station are configured to provide an initial product thrust of a bulk material into the open-mouth bag for unfolding the bottom end of the bag which is freely suspended above the conveyor device; wherein at least one compacting device is integrated in the conveyor device; and wherein the filling station is suitable for lowering the supporting structure with the appended open-mouth bag onto the conveyor device so that the bottom end of the open-mouth bag is supported from beneath by the conveyor device, and is processed by the compacting device upon contact of the appended open mouth bag with the conveyor device; wherein the height-adjustable supporting structure includes a pivot lever, wherein the pivot lever is configured to move vertically and wherein the filling spout is mounted on the pivot lever, such that the filling spout and the appended bag is moved between an elevated position and a lowered position by the movement of the pivot lever, wherein the bag is unsupported in the elevated position but can receive product through the filling spout, and wherein the bag is supported by the conveyor device when the filling spout is in the lowered position, and wherein the bag is appended to the filling spout when the filling spout is in the lowered position.

2. The apparatus according to claim 1, wherein the filling station is suitable to lower the supporting structure with the appended open-mouth bag after filling begins so that the bottom end of the open-mouth bag rests on the conveyor device at least for part of the filling process.

3. The apparatus according to claim 1, wherein the control device and the filling station are configured and set up to lower the supporting structure with the filling spout and the holding grippers to take over the open-mouth bag with the holding grippers; and to elevate the supporting structure with the appended open-mouth bag for the bottom end of the open-mouth bag to be freely suspended above the conveyor device as filling begins.

4. The apparatus according to claim 3, wherein the control device and the filling station are set up and configured to lower the supporting structure with the appended open-mouth bag for the bottom end of the open-mouth bag to rest on the conveyor device at least during part of the filling process.

5. The apparatus according to claim 1, wherein the compacting device is disposed beneath a bearing surface of the conveyor device.

6. The apparatus according to claim 1, wherein the filling station comprises a drive for elevating and lowering the supporting structure.

7. The apparatus according to claim 1, wherein the feed grippers and the discharge grippers are fastened to a support frame of a gripper conveying device.

8. The apparatus according to claim 7, wherein the gripper conveying device comprises swing arms and a pendulum drive.

9. The apparatus according to claim 1, wherein the filling spout is configured as a flap spout suitable to enter an open-mouth bag.

10. The apparatus according to claim 1, wherein the conveyor device is height-adjustable.

11. The apparatus according to claim 1, wherein a roll accommodation for accommodating a tubular film roll is comprised and/or wherein a bag forming station is comprised.

12. The apparatus according to claim 1, wherein a bottom seam station for generating a bottom seam and/or a top seam station for closing the open-mouth bag is comprised.

13. The apparatus according to claim 1, wherein at least one cooling station for cooling a closing seam is comprised.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The figures show in:

(2) FIG. 1 the apparatus according to the invention in a schematic side cross section in a first position;

(3) FIG. 2 the apparatus according to FIG. 1 in a second position;

(4) FIG. 3 the apparatus of FIG. 1 in a third position;

(5) FIG. 4a simplistic horizontal cross section of the filling station;

(6) FIG. 5 a side view of another filling station; and

(7) FIG. 6 the apparatus according to FIG. 1 in a fourth position.

DETAILED DESCRIPTION

(8) FIGS. 1 to 4 each show the same apparatus in a schematic side cross section in various positions or states. In all the figures, components and parts of the real apparatus have been omitted to simplify viewing. Although the FIGS. 1, 2, 3 and 6 show the same apparatus, not all the figures illustrate all the components and not all the figures show all the reference numerals.

(9) The apparatus 1 illustrated in the FIGS. 1, 2, 3 and 6 serves for filling bulk materials into open-mouth bags 2. Preferably the open-mouth bags 2 are manufactured in a bag forming station 27 of the apparatus 1. To this end the apparatus 1 comprises a roll accommodation 24 for a tubular film roll 25. The roll accommodation 24 may be mounted to, or placed separately in front of, the apparatus 1.

(10) A variety of deflection rollers 31 shown in simplistic views provide intermediate storage, not illustrated in detail, to enable the tubular film roll 25 to unwind quasi continuously. Alternately it is possible to feed prefabricated open-mouth bags to the apparatus 1.

(11) The apparatus 1 comprises a frame 40 to which the various components of the apparatus 1 are mounted. A bottom seam station 29 is disposed at the bag forming station 27, presently comprising a pair of welding jaws for making a bottom seam in the supplied tubular film 32. After indexing the tubular film 32 one bag length further, the cutting knife 33 cuts the bag off at the head end so as to provide a separate open-mouth bag 2 intended for filling. Grippers 10 (empty-bag grippers) hold the open-mouth bag 2. Meanwhile the bottom seam of the open-mouth bag 2 may be cooled in the cooling station 28 for the bottom seam to show the required stability for the quantity of product intended for filling.

(12) The bag forming station 27 is followed by a variety of processing stations, including in particular the filling station 5, the pre-opening station 39 and the top seam welding station 42 with welding jaws 41. The open-mouth bags 2 are transported between each of the stations (5, 27, etc.) by means of a conveying device 20 which ultimately conveys the open-mouth bags 2 linearly or horizontally through the apparatus 1. The conveying device 20 comprises a support frame 21 to which various sets of grippers 10 are mounted. The support frame 21 is held by a pair of swing arms 22 to swing between two pivot positions. The conveying device 20 is driven by means of a pendulum drive 23 in the shape of an electric motor which by means of an eccentric member 19 allows pendulum motions between forwardly pivoted and rearwardly pivoted support frame 21 positions. The filling station 5 comprises a drive 18 for elevating and lowering the supporting structure 8.

(13) In the forwardly pivoted position illustrated in FIG. 1 the shown open-mouth bag 2 can thereafter be appended to the filling spout 6, which is presently configured as a flap spout 26. In the rearwardly pivoted position, not shown, the open-mouth bag previously formed in the bag forming station 27, can be taken over by the feed grippers 11. With the next pendulum index the open-mouth bag 2 is conveyed further from the bag forming station 27 to the next station. The bag forming station 27 may be followed by another cooling station 28 or for example a bag opening station immediately follows in which the head end 30 of the open-mouth bag 2 is (pre-) opened e.g. by suction banks. Another index reaches the filling station 5 as is shown in FIG. 1.

(14) In the position illustrated in FIG. 1 the pre-opened open-mouth bag 2 is positioned beneath the filling spout 6. The bottom end 9 of the open-mouth bag 2 rests on the conveyor device 7. The conveyor device 7 is height-adjustably disposed on the frame 40 for compensating and setting different bag lengths by way of height adjustment 38. The conveyor device 7 is not height adjusted for each single filling so as to enable considerable ease of driving and a considerably simple configuration of height adjustment.

(15) Optionally the conveyor device 7 may be separately disposed on the floor. The conveyor device 7 comprises a belt section 15 that is in particular configured as a conveyor belt. The surface of the belt section 15 forms a bearing surface 17 for example for filled open-mouth bags 2.

(16) The belt section 15 is diverted by deflection rollers 14. An electric motor 37 may serve for driving.

(17) The conveyor device 7 extends up to beneath the filling station 5 and up to beneath the filling spout 6, such that a compacting device 16 received or disposed on the conveyor device 7 is likewise positioned beneath the filling spout 6 in the vertical direction.

(18) The compacting device 16 is received on the conveyor device 7 such that the compacting device 16, while it is active, acts on the carrying belt section 15 of the conveyor device 7 and on the bearing surface 17 of the conveyor device 7. This allows processing (after lowering the filling spout) an open-mouth bag 2 resting on the conveyor device 7 respectively an open-mouth bag 2 supported by the conveyor device 7, by means of the compacting device 16. This enables compacting the bulk material in the open-mouth bag 2 already during the filling process.

(19) First, however, the open-mouth bag 2 is appended to the flap spout 26, as FIG. 2 illustrates. To this end the supporting structure 8 receiving the filling spout 6 or flap spout 26 and the holding grippers 12 disposed thereat is lowered until the situation illustrated in FIG. 2 ensues. Then the tips of the flap spout already enter the pre-opened head end of the open-mouth bag 2. In the same way the holding grippers 12, not recognizable in FIG. 2, take over the open-mouth bag 2 in the gusseted region of the open-mouth bag, so that the grippers 10 on the support frame 21 can release the open-mouth bag 2 intended for filling. The bottom end 9 of the open-mouth bag 2 intended for filling is still resting on the conveyor device 7. With direct filling this would result in the bottom end not (always) cleanly unfolding.

(20) Thereafter the supporting structure 8 with the filling spout 6 and the holding grippers 12 is elevated to the position illustrated in FIG. 3. This elevation is achieved by a pivot lever 46 included in the supporting structure 8, the lever pivoting vertically relative to a fixed structure 47. Then the bottom end 9 of the open-mouth bag is elevated far enough so as to come out of contact with the conveyor device 7. However, there is at least a (small) gap between the bottom end 9 of the open-mouth bag 2 intended for filling and the bearing surface 17 of the conveyor device 7. At least the degree of freedom of the bottom end 9 is large enough so that the bottom can freely unfold with the first product (product thrust) entering.

(21) In FIG. 3 the flap spout 26 is furthermore tipped up so that the filling process can start. The flap spout together with the supporting structure 8 and the holding grippers 12 is in the elevated position 34. The supporting structure 8 is still in the elevated position 34. The bottom end 9 of the open-mouth bag 2 is freely suspended.

(22) Thereafter the filling process starts wherein bulk material is introduced into the open-mouth bag 2. The timed coordination is such (in particular based on empirical values) that the product thrust first entering the open-mouth bag 2 unfolds the bottom end 9 of the open-mouth bag 2 (as far as possible wrinkle-free). An unfolded bottom end 9a is schematically shown in broken lines in FIG. 3.

(23) Lowering the supporting structure 8 may be initiated thereafter or previously, by coordination, so that the conveyor device 7 in particular supports the bottom end 9 of the open-mouth bag 2 as soon as possible following unfolding the bottom end 9 of the open-mouth bag 2. This allows for the compacting device 16 accommodated there to act on the bottom end 9 of the open-mouth bag 2 and to effectively compact already during filling any bulk material that is already present.

(24) FIG. 3 also shows the spreader 43 which holds open the open-mouth bag 2 during transfer of the pre-opened open-mouth bag 2 to the filling spout 6.

(25) FIGS. 4 and 5 show two variants of the arrangement of the holding grippers 12 on the supporting structure 8 of the filling station 5. FIG. 4 shows a horizontal cross section of the filling station with the schematic, cross sectional view of the filling spout 6 to which an open-mouth bag 2 is appended. The supporting structure 8 retains the filling spout and also the holding grippers 12. The holding grippers 12 are shown in the closed state, gripping the gussets 3 of the open-mouth bag 2 for controlled retaining of the open-mouth bag 2 during the filling process. A holding gripper 12 in the opened state is also shown in broken lines. The holding gripper 12 needs to be pivoted outwardly far enough to allow discharging (and feeding) an open-mouth bag intended for filling between the holding grippers 12.

(26) FIG. 5 shows another variant with holding grippers 12 pivotable, not by vertical but by horizontal axes 36. The holding grippers 12 can pivot within the supporting structure 8 and they in turn serve to seize the gusseted regions 3 of the open-mouth bags 2. Again, the open-mouth bag 2 is received on the filling spout 6.

(27) FIG. 6 finally shows a schematic side cross section of the apparatus of FIG. 1, with a filled open-mouth bag 2 schematically inserted.

(28) The lowered position 35 of the supporting structure including the filling spout 6 and holding grippers 12 shown in FIG. 6 is taken shortly after beginning filling, so that the bottom end 9 of the open bag 2 intended for filling can already be processed by the compacting device 16 during a considerable portion of the filling process so as to achieve effective compaction of the bulk material intended for bagging.

(29) Since the apparatus shown is a high-performance machine which allows to manufacture and fill up to 2600 open-mouth bags and more per hour, the index time per each index is just slightly longer than 1 second. Thus, only a duration of mostly less than 1 second is available for the filling process proper. This is why an early beginning of effective compaction is considerably advantageous.

(30) On the whole the apparatus according to the invention and the method according to the invention offer considerable advantages since the efficiency of filling bulk materials into open-mouth bags can be increased considerably, involving little complexity and ease of operation, by way of a double spout lift. The conveyor device may and should be disposed up to beneath the filling spout so that a compacting device disposed there acts on the bottom end of the open-mouth bag already during filling. It is not required to have a drop-down conveyor belt as is provided in the prior art. It is sufficient to elevate the filling spout with the appended open-mouth bag and to start the filling process. During the filling process the open-mouth bag is lowered back down on the conveyor device and the compacting device contained therein. It has even been found that the drive for elevating the filling spout including the holding grippers does not need to be configured more powerful than the drive for elevating the filling spout used thus far, although now the supporting structure 8 does not only hold the filling spout 6 and the empty open-mouth bag 2 during the filling process but also holds a considerable portion of bulk material before the partially filled open-mouth bag 2 is deposited on the conveyor device 7.

(31) Furthermore, no thrust flaps are required for pulling the open-mouth bag 2 off a separate vibrator. This releases the load on the drive for the conveying device somewhat. The drive for the conveyor device 7 does not need to be designed more powerful since a filled bag had to be accelerated previously.

(32) The bulk materials bagged are preferably granular products. It is also possible to bag cement or similar products using the apparatus according to the invention.

(33) Another advantage is that a separate drive for elevating and lowering a compacting device can be dispensed with. The compacting device does not require elevating and lowering in operation.

(34) It is also advantageous that the compacting device can be integrated in the conveyor device or in the bag discharge belt where it may be positioned immediately beneath the carrying belt side. A considerable advantage is that the conveyor device is generally static and there is no drop-down section.

(35) While a particular embodiment of the present apparatus and method for filling bulk goods into open-mouth bags has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.

LIST OF REFERENCE NUMERALS

(36) TABLE-US-00001 1 apparatus 2 open-mouth bag 3 gusset 4 control device 5 filling station 6 filling spout 7 conveyor device 8 supporting structure 9 bottom end 9a unfolded bottom 10 gripper 11 feed gripper 12 holding gripper 13 discharge gripper 14 deflection roller for 15 15 belt section 16 compacting device 17 resting surface 18 drive for 8 19 eccentric member 20 conveying device 21 support frame 22 swing arm 23 pendulum drive 24 roll accommodation 25 tubular film roll 26 flap spout 27 bag forming station 28 cooling station 29 bottom seam station 30 head end 31 deflection roller for 32 32 tubular film 33 cutting knife 34 elevated position 35 lowered position 36 pivot point of 12 37 drive for 7 38 height adjustment of 7 39 pre-opening station 40 frame 41 welding jaw 42 top seam welding station 43 spreader