AU716697B2

AU716697B2 - Device for vacuumizing and closing bags

Info

Publication number: AU716697B2
Application number: AU38466/97A
Authority: AU
Inventors: Jurgen Haak; Dieter Schenk
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1996-09-28
Filing date: 1997-07-23
Publication date: 2000-03-02
Anticipated expiration: 2017-07-23
Also published as: PL332493A1; DE59702671D1; ES2153679T3; JP2001500825A; BR9712142A; AU3846697A; WO1998013264A1; HUP0001095A2; EP0928270B1; TW379184B; DE19640142A1; SK39199A3; HUP0001095A3; EP0928270A1

Description

I

-1- Prior Art The invention relates to a device for the vacuuming and closing of bags. In German Patent Application No. 40 13 273 there is disclosed devices of the kind that are part of a packaging unit in which, for example, bags filled with coffee are manufactured. The known device features a vacuuming chamber, the both halves of which can traverse the flat-folded head closure projecting from the shoulders of the body of the respective bag and can receive it during the vacuuming and closing procedure. The jaws of the seal, forming the one seal seam in the head closure of the bag are situated in the vacuuming chamber halves.

The performance of the known device which operates in steps is limited because of the time needed for the closing of the vacuuming chamber and the vacuuming of the bag contents. For this reason, with high performance packaging units, several devices, for example four devices, are employed simultaneously. To do this, during an idle phase of the conveyor transporting the bags, a bag is transferred by means of a transfer device to one of the devices. At the conclusion of the vacuuming and closing process, the bag is 20 channelled back during a further idle phase of the conveyor, into the conveyor again. An arrangement of this kind, of several devices, is very expensive as, alongside the devices themselves, additional transfer devices are needed.

Moreover, the arrangement of the several known devices requires a large amount of space.

Summary of the Invention According to the invention there is provided a device for the vacuuming and closing of bags whose flat-folded head seal stands up from shoulders of the base with two devices arranged adjacent to one another which receive the head seal of the bag sealing it from the atmosphere, for the vacuuming of the bag, the devices with a first suction opening connected to a vacuum source 17/12/99,td10213.spe.doc, 1 for the drawing out and drawing apart of the walls of the head closure and with at least a second suction opening for the suction of air or gas from the bag and with a sealing device arranged below the opening edge of the bag featuring two sealing jaws pressable into one another for the fixing of a sealing seam on the head closure of the bag, wherein the devices for vacuuming the bag are manufactured as endless suction conveyors arranged in contact with the head closure of the bag and that the sealing device is aligned with a lower section of said suction conveyors.

Advantages of the Invention The device of the invention has the advantage that it is both high performance and compact and is relatively simply constructed. The use of suction bands for the vacuuming of bag has, in addition, the special advantage that the efficiency of the device can be easily and simply increased to any extent through the length of the bands being increased. By means of a corresponding lengthening of the suction bands, even with a relatively high *4 conveying speed of the bags, a sufficiently long time for vacuuming and closure is achieved. The high performance of the device has the result that 20 even with high performance packaging plant which manufactures, per minute, S over 100 bags, a single device according to the invention suffices. No additional transfer devices are necessary. That is, the bags can remain in their conveyor, further reducing the manufacturing cost., A further advantage exists in that in the use of the suction band, it can be considered that the S 25 device is almost format-independent. This means that bags of any size and various foil thicknesses can be processed.

An adaptation to various height formats is possible, for example, through the distance of the suction bands from the conveyor. Further, the elasticity of the suction bands which, for example, are constructed of elastic plastics, guarantee an adjustment to various film thicknesses so that the distance 17/12/99,tdl 0213.spe.doc,2 2abetween the adjacent suction bands does not have to be adjusted. Because the suction bands are moved synchronously with the conveyor, both a cyclic operation and a continuous operation of the device is possible.

Further advantages and advantageous extensions of the device of the invention for the vacuuming and closing of the bags can be seen in the following description.

The arrangement of the sealing device below the upper suction bands has the advantage that the base up to the forming of the transverse seam at the head is constantly sealed so no air or oxygen returns to a bag once vacuumed.

Furthermore, the sealing device is separate from the actual vacuum device so that the seal device is very well accessible for cleaning and maintaining.

15 Diagram An embodiment example of the invention is depicted in the diagram and will be explained in more detail in the following description. Figure 1 shows a device for the vacuuming and closing of bags in a simplified frontal view, 0000 20 Figure 2 the device as in Figure 1 in a plan view, Figure 3 a section in the II1-111I plane of Figure 1, Figure 4 a longitudinal section through the intake area of the device and Figure 5 a section V-V plane of Figure 4.

Description of the Embodiment Example oi 17/12/99,td 10213.spe.doc,2 WO 98/13264 PCT/DE97/01556 -3- The device 10 for the vacuuming and closing of bags 1 is a constituent part of a packaging unit not depicted in detail. In the packaging unit, one bag 1 at a time is formed to a packing material pattern, is filled with a certain amount of material, eg. coffee, the filled bag, after passing the device 10, being directed to further stations, in particular a top sealing station and, if applicable, a labelling station.

For the transporting of the bags 1 to the individual treatment stations or in the device 10, a cyclic conveyor (11) operates with catches 12, 13 between which a bag is engaged and is taken up.

For the preparation of the bag 1 for the device 10, a folding station 15, not described in any detail is situated in front of the device 10 in which the side walls of the head area 2 of the bag 1 are folded flat resembling fins so that it stands up vertically from the shoulders of the base 3 of the bag 1.

The device 10 features at the top of the head area 2 of the bag 1 suction conveyors 16, 17 between which the head area 2 of the bag 1 is conveyed. Each of the suction conveyors 16, 17 consist of a lower, narrow suction band 18, 19 and an upper, wide suction band 21. The upper suction bands 20, 21 are constructed longer than the lower suction bands 18, 19. The suction bands 18 to 21 have a common driven reversing wheel 22, 23 extending to above both suction bands 18, 20 and 19, 21 and a lower reversing wheel 24, and an upper wheel 26, 27 each with a height corresponding to that of the respective suction band 18, 19 and 20, 21. Both driven reversing wheels 22, 23 are coupled together with one another and are driven by a motor not depicted so that the suction bands 18 to 21 move synchronously and at the same speed. This conveying speed of the suction bands corresponds, in turn, to the conveying speed of the conveyor 11.

The arrangement of the suction bands 18 to 21 is of a kind that the compartments of the suction band 18 to 21 facing both sides of the head area 2 of the bag 1 touch each other. In the surfaces of the suction bands 18 to 21, troughs are formed at equal intervals and are arranged in such a way that they each form a pocket 28 for a head area 2 of a bag 1. The pockets 28 are centred with the head areas 2 of the bags 1 and feature a lesser width than the bags 1. Furthermore, the troughs in the lower suction bands 18, 19 are constructed over their complete height while in the upper suction bands 20, 21 they extend to a part of WO 98/13264 PCT/DE97/01556 -4their height so that the upper suction bands 20, 21 cover the opening of the bag 1 in each case. The height of the pockets 28 corresponds, then, to at least the height of the head area 2 of the bags 1. In the compartments of the suction bands 18 to 21 in the area of the troughs, holes 29, 30 are made, the size of the holes 29 allocated to the upper suction bands 20, 21 being greater than the size of the double row of lower holes 30. Further, the upper holes 29 are arranged in a chamber-like extended area 31 of the pockets 28 which is above the head area of a bag 2. The holes 29, 30 work together with slit-shaped suction channels 32, 33 in suction strips 34, 35 and 36. The suction strips 34 to 36 are in a vacuum body 37, 38 respectively arranged between the compartments of the suction bands 18 to 21. A suction hole 39 extending from the upper side of the vacuum body 37, 38 and opening into the suction channel 32 while the suction channel 33 is connected to at least one vacuum source not depicted.

For the forming of the transverse head seams 4 in the head areas 2 of the bags 1, a sealing device 41 with pieces which can be positioned against one another is arranged below the upper suction bands 20, 21. In an extension of the lower suction bands 18, 19 is a compression device 42 for the compression of the material filling the bags 1.

The device described above operates as follows: the bags 1 filled and prefolded in the folding station 15 in the head area 2 are brought, stepwise, by the conveyor 11 between the suction conveyors 16, 17 which are also driven stepwise and in synchrony with the conveyor 11. There, the head areas 2 reach the vicinity of the pockets 28 of the suction bands 18 to 21. The walls of the head areas 2 of the bags 1 are drawn at this point through the lower holes 30 so that an opening to the inside, that is to the material the bag is being filled with, is formed. The contents of these bags 1 are vacuumed through the resulting opening through the upper holes 29, ie. the remaining oxygen is removed from the bags 1 for the purpose of better shelf life of the contents. Where necessary, a gassing of the contents using protective gas, takes place. Simultaneous with the vacuuming process of the bags 1, the compression or pressing of the contents takes place by means of the compression device 42. Additional air is pressed out of the bags 1 by means of the pressing of the contents, supporting the vacuuming.

After the vacuuming process is completed, ie. the desired negative pressure is reached and the bags 1 come out of the area of the lower suction bands 18, 19 into the sealing area 41.

WO 98/13264 PCT/DE97/01556 There, during an idling phase of the conveyor 11 in the head area 2, the head transverse seam 4 of each bag is sealed. As the upper suction bands 20, 21, after the bag leaves the area of the lower suction bands 18, 19 before the sealing of the head area 4 of the bag 1 by means of the sealing device 41, remain in cooperation with the bag 1, air or oxygen is prevented from returning to the as yet unsealed bag 1.

After the transverse head seam 4 in the bag 1 is sealed, the bag 1 is moved with the next motion of the conveyor out of the area of the device 10 to be directed to the next station.

Claims

1. A device for the vacuuming and closing of bags whose flat-folded head seal stands up from shoulders of the base with two devices arranged adjacent to one another which receive the head seal of the bag sealing it from the atmosphere, for the vacuuming of the bag, the devices with a first suction opening connected to a vacuum source for the drawing out and drawing apart of the walls of the head closure and with at least a second suction opening for the suction of air or gas from the bag and with a sealing device arranged below the opening edge of the bag featuring two sealing jaws pressable into one another for the fixing of a sealing seam on the head closure of the bag, wherein the devices for vacuuming the bag are manufactured as endless suction conveyors arranged in contact with the head closure of the bag and that the sealing device is aligned with a lower section of said suction conveyors. i. 2. The device as claimed in Claim 1, wherein each suction conveyor has an upper suction band and a lower suction band, that the upper suction S bands cover the edge of the opening of the bag, that the length of the lower suction is less than the length of the upper suction bands and that the sealing 20 jaws of the sealing device in an extension of the lower suction bands are S.o. Sc .06:0, arranged below the upper suction bands.

3. The device as claimed in Claim 2, wherein the lower suction bands, the first suction openings are constructed for the drawing in and drawing apart of the walls of the head closure of the bag and, in the upper suction bands, the at least one second suction opening is constructed for the removal of air or gas from the bag.

4. The device as claimed in any one of Claims 1 to 3, wherein the sides of the suction conveyors facing the head seals of the bag lie on each other, in the reception area of the head seal of a bag, trough-like indentations being formed from the surface of the suction conveyors forming a bag-shaped chamber in which the head closure of the bag is completely taken up. 17/12/99,td10213.spe.doc,6 -7- The device as claimed in Claim 4, wherein each band has several trough-shaped indentations, each equidistant from the next.

6. The device as claimed in any one of Claims 1 to 5, wherein between the compartments of the bands a vacuum body is arranged and that the vacuum body features suction strips connected to the vacuum source on the sides facing the head closure of the bag.

7. The device as claimed in any one of the Claims 1 to 6, wherein the bands are arranged above a conveyor transporting the bags.

8. The device as claimed in Claim 7, wherein the conveyor is constructed as a "cup chain" with catches.

9. The device as claimed in Claim 7 or 8, wherein at least one device for the compressing of the contents of the bags is arranged below the bands. A packaging unit with a device for the vacuuming of and the closing of bags as claimed in any one of Claims 1 to 9. Dated this 1 7 th day of December, 1999. 0 ROBERT BOSCH GMBH 20 By their Patent Attorneys: CALLINAN LAWRIE 17/12/99,td10213.spe.doc,7