WO1997016347A1

WO1997016347A1 - Method and device for the production of evacuated packets filled with loose bulk material, in particular ground coffee

Info

Publication number: WO1997016347A1
Application number: PCT/CH1996/000361
Authority: WO
Inventors: Benno Himmelsbach; Siegfried Meier
Original assignee: Sig Pack Systems Ag
Priority date: 1995-10-30
Filing date: 1996-10-15
Publication date: 1997-05-09
Also published as: AU7124096A; EP0858411A1; EP0858411B1; DE59604132D1

Abstract

The invention relates to cuboid-shaped packets (1) with loose bulk material and still open at the top. The said packets are transferred from a first linear conveyor (12) to a rotating intermediate conveyor (13) which transfers the packets to a revolving table (57). Vacuum hoods (81) are arranged on the revolving table (57) at regular intervals and are lowered after the transfer operation. The packets (1) are evacuated and compressed when in the one horizontal direction and held when in the second horizontal direction. After transverse sealing, the packets (1) are returned to the linear conveyor (12) by a second intermediate conveyor (15). The continuous operation of the conveyor achieved by the above device results in a high rate of production with careful handling of the packets.

Description

Method and device for producing evacuated packs filled with bulk goods, in particular ground coffee

US Pat. No. 4,538,399 describes a method and a device for producing evacuated packs containing ground coffee. The still unsealed packagings are delivered on a conveyor belt in holders at regular intervals. At a transfer point, the packs are pushed in pairs on a rotary table, which contains vacuum hoods. The rotary table has two side walls for each pack, one of which can be swiveled. Facing the axis of the turntable there is a third side wall designed as a ram. A fourth side wall is located on a wall of the lowered hood. During the evacuation, this plunger is pressed against the fourth side wall, so that the package is simultaneously compressed during the evacuation. With this device it is possible to produce guaderiform packs with flat side surfaces. The finished packs are pushed back onto the conveyor belt. The conveyor belt as well as the transfer device and the turntable move in cycles. 97/16347 PO7CH96 / 00361

The present invention has for its object to increase the performance of such a device. This task is solved by the combination of features of claims 1 and 4.

The second and fourth conveyors are preferably each designed as intermediate conveyors, which take over the packs from a first, preferably linear, conveyor or transfer them to it. Because the packs are each transferred to the third conveyor and back via an intermediate conveyor, this intermediate conveyor can have the same direction of movement on the transfer orders as the first or third conveyor, which is the case with the device described at the outset in accordance with US Pat 4,538,399 is not possible. This enables the transfer to take place with continuously running conveyors. Therefore, higher packaging performances can be achieved with careful handling of the packs.

However, the second and fourth conveyors do not necessarily have to be designed as intermediate conveyors. Instead of the only linear feed and discharge conveyor according to the prior art, a separate feed conveyor and discharge conveyor can also be used, e.g. be provided at diametrically opposite locations on the third conveyor. This variant also allows a continuous operation instead of an interactive one.

An exemplary embodiment of the invention is explained below with reference to the drawings. It shows:

FIGS. 1 to 3 show a perspective view of the package in the open, semi-closed and sealed state, FIG. 4 shows a top view of the transfer points,

FIG. 5 shows a detail of the one transfer point,

FIG. 6 shows a side view of the transfer point,

FIGS. 7 and 8 vertical sections through a vacuum hood,

Figure 9 is a horizontal section through the hood, and

Figure 10 is a schematic vertical section through the vacuum wheel.

1 shows a package 1 made of a flexible film 2 in the open state. It has a longitudinal fin seam 4 laid flat on a side surface 3 and a bottom 5 which is folded and cross-sealed analogously to the illustration according to FIGS. 2 and 3. the package is filled with bulk goods up to level 6 shown in broken lines, e.g. ground coffee, filled. In the device described below, this pack is provided with double folds 7 at the upper edge (FIG. 2), evacuated and finally sealed with a transverse sealing seam 8 (FIG. 3).

In FIG. 4, transfer points between a feed and discharge conveyor 12, a second conveyor 13, a third conveyor 14 and a fourth conveyor 15 are shown schematically. The conveyor 12 has, at regular intervals, receiving pockets 16 with parallel side walls 17, which run transversely to the transport direction A, for receiving a pack 1 each. It can be designed, for example, as a chain conveyor or as a conveyor belt. The intermediate conveyors 13, 15 have the same structure. They have a turntable 23, 24 driven about a vertical axis 21, 22. Holding elements 25, 26, which consist of two vertically standing angle plates 27, 28, are uniformly distributed over this circumference. Each sheet 27, 28 is fastened to an arm 29, 30. For the sake of a better overview, these arms 29, 30 and their actuation are only shown in one of the holding elements 25 of the conveyor 13. The arms 29, 30 can be pivoted independently of one another about a common, vertical axis 31 and are offset from one another in the axial direction. Together with two further arms 32, 33 they form a double-armed lever. The two arms 32, 33 carry rollers 34, 35 at their free ends. The rollers 34, 35 roll on separate, vertically offset cams 36, 37. The arms 29, 30 are tensioned against one another by a prestressed tension spring 38. The cams 36, 37 are designed such that the side walls of the sheets 27, 28 at the transfer point 39 move from the conveyor 12 to the conveyor 13 parallel to the side walls 17 of the pockets 16. When approaching the transfer point 39, the side walls 27 are still a little larger apart than the side walls 17. The circumferential speed of the axes 31 is approximately equal to the transport speed of the conveyor 12.

At the transfer point 39 there is a plunger 44 on the side of the conveyor 12 opposite the conveyor 13, which can be pushed for example by means of a pneumatic cylinder 45 perpendicular to the direction of transport A in order to bring a product 1 out of a pocket 16 into a pocket to align aligned retaining element 25. The cylinder 45 is moved back and forth in the transport direction, for example by means of a chain 46 rotating over two wheels and a parallel guide, not shown, in such a way that it rotates synchronously with the conveyor 12 for the transfer of the package 1. As soon as the pack 1 is pushed into the associated holding element 25, the cams 36, 37 have a slightly smaller radius, so that the sheets 27 are pressed against the filled pack 1 by the spring 38. A stationary, horizontal sliding plate 47 supports the packs 1 in the area of the conveyors 12 to 15 and the transfer points 39, 51, 55, 56 so that they do not slide down.

The finished packs 1 are transferred from the conveyor 15 to the conveyor 12 in a corresponding manner also by means of a plunger 48 with a periodically moving cylinder 49 and sliding plate 47 at the transfer point 51.

The transfer point 55 from the conveyor 13 to the conveyor 14 is shown in FIGS. 5 and 6. The transfer point 56 from the conveyor 14 to the conveyor 15 functions analogously. The conveyor 14 also includes a turntable 57 which rotates continuously about a vertical axis 58 (Figure 10). A vertical guide plate 59 extending in the form of a cylindrical segment extends between the positions 39, 55. On the plate 57, rear walls 60 are mounted at regular intervals distributed over the circumference, and side walls 62 which can be pivoted about vertical axes 61 and are divided in height. The upper part 63 can be pivoted separately from the lower part 64. The parts 63, 64 are controlled by a total of four cam discs 65, 66, 67, 68 via levers 70 and rollers 71 in such a way that all parts 63, 64 are spread directly in front of the transfer point 55, approximately as the middle plane of the pack 1 passes through by the common plane of the axes 21, 58 of the turntables 23, 57, the upper parts 63 are pressed against one another by the force of springs 69 (FIG. 9), so that they hold the packs 1. Thereupon the metal sheets 27, which pass below the parts 63, open. As soon as the holding elements 25 come out of the Once the packs 1 have turned away, the lower parts 64 of the side walls 62 also close. The side walls 62 are now pressed against the pack 1 by the springs 69. Only a small gap of less than two millimeters, preferably less than 1% of the height of the side walls 62 is provided between the upper and lower parts 63, 64. The gap between the parts 63, 64 is above half the height of the side walls 62.

When the table 57 continues to rotate, a base plate 73 is raised by a cam 74, so that the base 5 of the pack 1 is supported. The height of the cam disk 74 can be adjusted by a cylinder 75. The cylinder 75 is controlled by a control device 76 in the function of a sensor 77, which measures the level 6 of the bulk material in the package 1. The bulk height of the bulk material can namely vary despite the same bulk material weight depending on the degree of grinding of the batch being processed. The sliding plate 47 is shown rotated by 90 ° in FIG. 6. In reality it runs in front of the lowered base plate 73.

When the turntable 57 is turned further outside the area of the conveyor 23, a vacuum hood 81 (FIGS. 7 to 9) moved along with the table 57 is moved down over the pack 1. Each vacuum hood 81 is guided vertically displaceably on the table 57 by means of a rod 82 (FIG. 10). The rods 82 have a roller 83 at the bottom, which rolls on a cam 84. Thus, the hoods 81 are raised before reaching the transfer point 56 and lowered after passing through the point 55. In the lowered position, a sealing ring 85 seals the interior of the hood 81 by resting on the table 57. The hood 81 has a wedge 87 on each of its two side walls 86. The inner surfaces 88 of the two wedges 87 diverge towards the bottom. When the hood 81 is lowered, these surfaces 88 run up Rollers 89, which are rotatably mounted on the lower parts 64 of the side walls 62. The upper parts 63 are taken along by drivers 90 (FIG. 6). When the hood 81 is in the lowered position, the inner surfaces of the side wall parts 63, 64 lying one above the other are therefore in alignment and are parallel to the inner surfaces of the opposite side wall parts 63, 64.

A front wall 96 of the pack holder 97 of the table 57 is fastened to the front wall 94 of the hood 81 by means of a parallelogram linkage 95. In the raised position of the hood 81 (indicated by a dot-dash line at the top right corner in FIG. 7), the wall 96 is pivoted away from the wall 60. When the hood 81 is lowered, a roller 98 rotatably mounted on the wall 96 runs on a plate 99 and pivots the wall 96 from the basic position into a shark position.

The walls 60, 96 each have a plate-shaped support 105, on which a membrane 106 is attached. Each membrane 106 carries a plunger 107, on which a rectangular plate 108 is attached. The length and width dimensions of the plates 108 are slightly larger than those of the pack 1.

After the hood 81 has been lowered, the side walls 62 are fixed in their end position and hold the pack 1 in position. The base plate 73 is raised into the required position by the control device 76. At the same time, the interior 111 of the hood 81 is evacuated, the spaces 112 between the membrane 106 and the carrier 105 being able to be connected to the same vacuum in a first phase. Subsequently, these opposite rooms 112 are pressurized with compressed air. The package 1 is thus pressed in the horizontal direction so that its other Place the other side surfaces and the base 5 and the cover surface against the fixed side walls 62, the base plate 73 and an only indicated cover plate 113. The cover plate 113 is in two parts and part of the conventional folding device (not shown) for producing the gusset folds 7. Towards the end of the pressing process, the transverse sealing seam 8 is formed with transverse sealing jaws 114. These sealing jaws 114 are also only indicated because their mode of operation is known in the art.

After sealing, the interior 111 is reconnected to the atmosphere and the hood 81 is raised by means of the cam disc 84 before the package 1 in question reaches the transfer point 56.

At this point 56 the reverse process occurs as at point 55. First, the lower parts 64 of the side walls 62 open so that the spread sheets 28 of the holding elements 26 can retract. The bottom plate 73 is lowered. Now the sheets 28 close and hold the finished package 1, whereupon the upper parts 63 open, so that the package 1 extends on the conveyor 15 from the side walls 62 of the conveyor 14. Finally, the pack 1 is pushed onto the conveyor 12 at point 51.

The configuration described makes it possible for the packs 1 to be evacuated in the case of continuously running conveyors 12 to 15, to be pressed into a cuboid-shaped package with flat side surfaces, and to be closed. A high packaging speed is achieved with gentle handling and thus avoiding injuries to the packaging film.

A vertical section through the conveyor 14 is shown schematically in FIG. The turntable 57 is on a zy Lindric stand 118 rotatably mounted. It is driven, for example, by a motor 119 via bevel gears 120, 121. Two lines 122, 123 are guided in the stator 118. The line 122 is connected to a compressed air source 124, the line 123 to a suction pump 125. Above the lines 122, 123 each lead into an annular groove 127, 128 in a hub 126 of the turntable 57.

A control unit 131 is assigned to each hood 81 and is supplied with current via taps 133 by slip rings 132. Each control unit 131 is assigned two switches 134, 135 and two valves 136, 137. The switches 134, 135 are actuated by cams 138, which are rigidly connected to the stand 118. The valves 136, 137 are connected via a line 139 to the groove 127 and thus to the suction pump 125, the valve 136 additionally via a line 140 to the compressed air source 124. The valve 137 controls the negative pressure within the hood 81 after it has been lowered and fill it with atmospheric air before lifting. The valve 136 initially connects the spaces behind the membranes 106 to the suction pump 125 until the base plate 73 is raised to the final height. The rooms are then connected to the compressed air source 124. The packs 1 are thus compressed in the radial direction of the rotary table 57 by the flat plates 108.

Claims

claims

1. A method for producing evacuated packs (1) filled with bulk goods, in particular ground coffee, the packs (1) being fed from a first conveyor (12) to a second conveyor (13) and from this one third conveyor (14) is transferred, which contains a plurality of accompanying vacuum hoods (81), the packs (1) after evacuation and sealing being transferred to a fourth conveyor (15) and from there back to the first conveyor (12), and after the transfer of the packagings (1) from the second conveyor (13) to the third conveyor (14) a first pair of side walls (62) for holding the packagings (1) is brought into its closed end position, a second pair of sidewalls (108) is brought into an intermediate position and in a second step, with the vacuum in the vacuum hood (81), the second pair of side walls (108) is brought into its pressed position.

2. The method according to claim 1, wherein a base plate (73) supporting the packing base (5) is raised into an upper end position before the initiation of the second step.

3. The method according to claim 1 or 2, wherein the second pair of side walls (108) is moved into the pressing position by a member (106) which can be acted upon by a pressure medium.

4. Device for carrying out the method according to one of claims 1 to 3 for producing evacuated packs (1) filled with bulk goods, in particular ground coffee, comprising a first conveyor (12) for feeding the unsealed packs (1) Via a second conveyor (13) to a third conveyor (14), which has a plurality of moving vacuum hoods (81), and a fourth conveyor (15) for receiving the sealed packages (1) from the third conveyor (14) and for transferring them of these packages (1) onto the first conveyor (12), the third conveyor (14) having first and second pairs of side walls (62, 108) assigned to each hood (81), the first pair of side walls (62) being driven by a first drive means (65 -69, 87) can be moved from an open basic position into its end position and the second pair of side walls (108) can be moved from a basic position into an intermediate position and through a third A by a second drive means (95, 98, 99) ntriebsmit¬ tel (106) is movable into its pressing position.

5. The device according to claim 4, wherein the second and fourth conveyor (13, 15) are each rotatable about a vertical axis (21, 22) and have a plurality of holding elements (25, 26) for receiving the packs (1).

6. The device according to claim 5, wherein the holding elements (25, 26) at the transfer point (39, 51) from or to the first conveyor (12) in an approximately parallel direction to holding members (16) on the first conveyor ( 12) are movable, and they are designed such that they open at the transfer points (55, 56) to and from the third conveyor (14).

7. Device according to one of claims 4-6, wherein the second drive means two parallel levers (95) comprises one end of which is articulated on the hood (81) and the other end of which is articulated on a side wall holder (105).

8. Device according to one of claims 4 to

7, the third drive means each comprising a membrane (106) which can be acted upon by a pressure medium.

9. Device according to one of claims 4 to

8, the side walls of the first pair of side walls (62) being pivotable about axes (61) and the first drive means (65 to 69, 87) comprising springs (69) and cams (65 to 68) for pivoting these side walls (62).

10. The device according to claim 9, wherein the first drive means additionally comprises rollers (89) which run up on wedges (87) on the side walls (86) of the hood (81) when the hood (81) is lowered.

11. The device according to one of claims 4 to 10, wherein the third conveyor (14) has holding means (63) for holding the packs (1) during transfer from the second conveyor (13).

12. The apparatus of claim 11, wherein the side walls (62) of the first pair of side walls are divided in two in height and the upper part (63) of these side walls (62) is pivotable into the partition independently of the lower part (64).

13. The apparatus of claim 12, wherein the separation point between the lower and upper side wall part (63, 64) is arranged above half the height of the side wall pairs (62).

14. The apparatus of claim 12 or 13, wherein the gap between the upper and lower side wall part (63, 64) is less than 1% of the height of the first side wall pair (62).

15. Pack with bulk material, in particular ground coffee, produced by the process according to one of claims 1 to 3, wherein all six side faces of the pack are flat and at least the side edges are uniform and not over the planes of the adjacent side faces protrude.