EP0028119A1

EP0028119A1 - Apparatus for packaging goods, especially a compressed stack of insulating mats, in a bag or a sack

Info

Publication number: EP0028119A1
Application number: EP80303723A
Authority: EP
Inventors: Tage Lund Johansen
Original assignee: BRDR JORGENSEN ELEKTRO Aps
Current assignee: BRDR JORGENSEN ELEKTRO Aps
Priority date: 1979-10-29
Filing date: 1980-10-22
Publication date: 1981-05-06
Also published as: NO803201L

Abstract

In an apparatus for packaging especially a compressed stack of mineral wool mats (23) in a bag or a sack (9), provision has been made, in view of reducing the manual work required, of a fully automatic mechanism for opening the flat-folded bags and drawing them on to a packaging beak (19) through which the material can be pushed forward to the bottom of the bag. This mechanism comprises a set of holders (6, 7) with grippers (13) for temporarily grasping the flat-folded bag (9) and enlarging the open end of said bag by increasing the space between the holders, and for drawing the bag on to the packaging beak (19). While this bag is filled, the next bag can be received by the holders to be ready for filling as soon as the first bag has been removed from the packaging beak.

Description

The present invention relates to an apparatus which is primarily designed for packaging a compressed stack of insulating mats in a bag or a sack but can also be used for goods of another kind.
When the goods concerned are insulating mats in the form of ready-cut rectangular batts or slabs of mineral wool having, for example, a size of about 0.6 x 1.2 m and a thickness between 50 and 125 mm, the packaging takes place generally by stacking a suitable number of such slabs to a height of, e.g., 0.7-1 m and passing the stack between an upper and a lower plate while exerting a certain compression in the vertical direction. Before its passage between these plates, the stack meets a foil web composed of an upper foil and a lower foil drawn from their respective feed roll and welded together along a horizontal seam located approximately midway between the plates. This composite foil web is drawn along by the stack when passing between the plates, so as to be tightened around the stack, the upper and lower foil being then welded together to form a rather broad seam behind the stack. The seam is cut through along its centre line, so that one portion forms the closure of the package around the stack while the other portion of the seam connects the ends of the next lengths of upper and lower foil to be used for packaging the subsequent stack. The packaged stack can then pass through a shrinking tunnel where the packaging foil is shrunk to such an extent that the height of the stack can be reduced up to 50% when finally packaged. It goes without saying that this results in the foil being subjected to a high tension which should in itself be easily tolerated even by a thin foil but which, all the same, has proved to result in breakage in many cases, because the foil has been weakened at the welding seam. Such breakage may take place immediately after the packaging or during transport and storage, and in both cases it results in considerable and troublesome additional work. When using a thicker foil or a lighter compression of the stack, the risk of breakage is of course reduced, but only at additional costs of material and transport, respectively. A further price-increasing factor of this packaging method is connected with the shrinking of the foil placed around the stack, which requires a substantial consumption of energy.
Unlike this known technique, the present invention relates to an apparatus for packaging goods, in particular a compressed stack of insulating mats, in a bag or a sack, and comprising a packaging beak through which the stack is led to the bottom of the bag, after the open end of said bag has been drawn on to the beak around its free end.
Packaging of mineral wool slabs according to this principle has been used for a number of years in the following manner: the height of the stack is first subjected to a reduction of up to 50%, whereafter the stack is pressed forward through the packaging beak, after a prefabricated bag or sack has been manually pulled on this beak so that it can accommodate the compressed stack without allowing it to expand again vertically to an appreciable extent. While continuing its movement through the beak, said stack draws off the sack from the beak, whereafter the mouth of the sack can _'be closed by welding or lacing. This method as hitherto practised requires a substantial amount of personnel, as it presupposes three working stands manned with five persons each, when work is carried on continuously.
The main object of the present invention is to provide an apparatus allowing a radical reduction of the staff required, and for this purpose the apparatus according to the invention is characterized by providing, in front of the free end of the packaging beak, a mechanism adapted for receiving and opening flat-folded bags and for drawing them on to the beak, said mechanism comprising two sets of holders with grippers for a respective side wall of the bag, which holders are movable away from each other for the opening of the bag and are further movable from a bag receiving position laterally displaced in relation to the packaging beak to a position in alignment with the beak, in which latter position the grippers while still firmly engaging with the side walls of the bag are displaceable parallel to the packaging beak to place the open bag thereon.
Thus, this apparatus makes use of prefabricated bags or sacks which can, without becoming economically unwarranted, be made in such a quality that they can stand without breaking the very high inner pressure exerted by the highly compressed stack, rendering a subsequent shrinkage unnecessary, although such shrinkage may possibly be envisaged in special cases.
The desired reduction of staff results from the fact that the opening of the flat-folded bags as well as their placing on the packaging beak are carried out fully automatically and in such a way that the various operations do not interfere with each other. The non- interference aspect is the reason why at any rate the initial opening of the bags takes place in a position which is laterally displaced in relation to the packaging beak, thereby allowing the reception and the initial opening of a bag to take place simultaneously with the filling of a preceding bag with a stack of insulating mats passing through the packaging beak. As soon as this bag has been released from the beak, the next bag can, by means of the holders, be opened to a maximum and be shifted to a position opposite the beak and be pushed onto said beak, whereafter the holders can immediately return to their receiving position for preparing the next bag.
Further details of the apparatus according to the invention are explained in the following with reference to the'drawing in which

Fig.1 shows rather schematically the essential elements of a preferred embodiment of the apparatus, and
Fig.2 shows a lateral view on a larger scale of the holders with associated grippers forming part of the apparatus according to Fig.1.

In Fig.1, 1 and 2 indicate horizontal elements belonging to the support (not shown in detail) of the apparatus, and 3 is a vertical standard forming part of said support. In this standard are mounted a couple of reversible chain drives 4 and 5 for two holders 6 and 7, respectively, which are shown in the above-mentioned receiving position. 8 indicates a carriage or slide for carrying forward between the holders 6 and 7 a flat-folded bag 9. This bag 9 can in a conventional manner be fed from a stock or it can, also in a known manner, be made just before from a tubular foil which at suitable intervals corresponding to the desired bag length is sealed by means of a transverse welding seam 10 forming the bottom of the ready bag.
Each of the holders 6 and 7, see in particular Fig.2, can be designed as a pneumatic cylinder 11 having a piston rod 12 carrying a gripping head 13 which by suitable control of the pressure fluid admitted to the cylinders 11 is displaceable backwards and forwards, as indicated by the arrows 14' in Fig. 2. On their sides facing each other, the grippers are provided with suction cups 14 and spring clips 15 for temporarily gripping the bag 9. For this purpose the carriage or slide 8 is displaced to the left from the position shown in Fig.2, until the end of the bag which is held to the carriage or slide 8 by means of a releasable clip 16 has passed the spring clips 15. Thereafter, the grippers 13 are drawn nearer to each other, so that the opposite lateral walls of the bag are grasped by their respective suction cups 14 after establishing a suitable partial vacuum. The clip 16 is then released and the carriage 8 is withdrawn from the space between the grippers 13 which are again moved a little farther from each other to initiate the opening of the bag 9. Afterwards, a pair of angular swinging arms 16 pivotally mounted in the foremost end of the grippers 13 are actuated, said arms being so arranged that their free bent ends, when pivoting in the directions indicated by arrows, land in the spring clips 15 and thereby form an outward fold in each of the two lateral walls of the bag. When the arms 16 have been swung back to the position shown in Fig.2, the folds in question will remain in engagement with the spring clips 15, whereby the gripping of the bag 9 is intensified. As indicated in Fig. 2, each of the swing arms 16 can be carried by a shaft 17 in frictional or toothed engagement with a reciprocating driving rod 18 which can, for instance, be actuated by a pneumatic cylinder (not shown) mounted in the associated gripper 13.
When the bag 9 has in this manner been firmly secured to the two holders 6 and 7 with the grippers 13, the opening of the bag is completed by moving the holder 7 away from the holder 6, whereafter the two holders together are laterally displaced until the open bag is facing a packaging beak 19, Fig.1, which may be of conventional design and therefore is not shown in detail. In the embodiment shown in the drawing, it is assumed that the said lateral displacement takes place in the vertical direction, thus that the holders in the receiving position are positioned on a higher level than the beak 19.
This beak 19 is provided with a support (not shown) having an upper and a lower endless band 20 running in the directions indicated by the arrows, the paths of which are determined by the guiding and return rollers 21 and 22. The inner and forwardly running band portions converge, at any rate until they meet the guiding rollers 21 and possibly to the region of the return'rollers 22, and they contribute thereby to a vertical compression of the stack of mineral wool mats 23 to be packaged.
When the holders 6 and 7 with the open bag 9 have been positioned in front of the packaging beak 19 as explained above, the pneumatic cylinders 11, Fig.2, are actuated, whereby the grippers 13 are moved forward parallel with the beak 19 so as to position the open end of the bag 9 around this beak. Adjacent the outer faces of the beak are placed rotating brushes 24 driven by their respective motors 25 and running continuously in the directions indicated by arrows. In the advanced position of the grippers 13, these rotating brushes 24 together with the external, back-running portions of the bands 20 of the beak will catch the edge portions of the lateral walls of the bag which thereby are drawn or swept onto the beak and possibly smoothed out along said beak as indicated by the dotted line in Fig.1. Latest during this operation the partial vacuum in the suction cups 14 has been released and the pull exerted by the brushes 24 on the lateral walls of the bag is sufficient to free these walls from the spring clips 15.
When the bag has in this manner been transferred to the beak 19, the holders 6 and 7 return to the receiving position shown in Fig.1 and the foremost stack of mineral wool mats 23 in the beak 19 is pushed forward to abut against the flattened bottom of the bag 9 and further-onso as to draw the bag clear of the beak. The filled bag falls then down on a band conveyor 26 and when it has been entirely released from the beak 19 and is at a bag's length therefrom, the next bag can be placed on the beak in the manner explained above.

Claims

1. An apparatus for packaging goods, especially a compressed stack of insulating mats (23), in a bag or a sack (9), comprising a packaging beak (19) through which the stack is led to the bottom of the bag, after the open end of said bag has been drawn on to the beak around its free end, characterized by providing, in front of the free end of the packaging beak (19), a mechanism adapted for receiving and opening flat-folded bags (9) and for drawing them on to the beak, said mechanism comprising two sets of holders (6, 7) with grippers (13) for a respective side wall of the bag, which holders are movable away from each other for the opening of the bag (9) and are further movable from a bag receiving position laterally displaced in relation to the packaging beak (19) to a position aligned with the beak, in which latter position the grippers while still firmly engaging with the side walls of the bag are displaceable parallel to the packaging beak to place the open bag thereon.

2. An apparatus as claimed in claim 1,
characterized in that the grippers (13) are provided, on their sides facing each other, with suction cups (14) for grasping the opposite lateral walls of the bag during the initial opening of said bag, and spring clips (15) for gripping the lateral walls of the bag till it has been positioned on to the packaging beak (19).

3. An apparatus as claimed in claim 2,
characterized in that the spring clips (15) are arranged for gripping an outward fold of the respective side wall of the bag and that the grippers (13) are provided with angular swinging arms (16) which after the initial opening of the bag are movable from a rest position to a position into the bag to form the outward folds in the spring clips (15) and thereafter are movable back to their rest position outside the bag, the folds being retained in the spring clips.

4.. An apparatus as claimed in claim 3,
characterized in that in connection with the packaging beak (19) provision is made of rotating brushes (24) arranged for catching, together with the outer side of the beak, the edge portions of the lateral walls of the bag, in the advanced position of the grippers (13), for pulling the folds of these walls free from the spring clips (15) and for sweeping the bag (9) on to the beak.