The present invention relates to a method for packing products in a container, especially a trough- shaped package, with the use of a packing means, by which method the products are first grouped next to the packing means which is downwardly open and has two substantially vertical spaced-apart walls.

The invention also relates to a device for packing products in a container, especially a trough-shaped package, said device comprising a packing means, a means for feeding previously grouped products to the packing means, and a means for moving the packing means from a product feeding position to a product depositing position just above or inside the package. The packing of products in trough-shaped packages is still almost exclusively carried out manually, especially with food products, such as biscuits and hamburgers, which of course is hygienically unsuitable. Furthermore, manual packing is time-consuming and- requires a large number of packers, thus entailing heavy expenses. The production capacity that can be achieved by manual packing is simply too low. At present, there are no machines on the market which can replace, in a satisfactory manner, the manual packing prevalent in the food industry. A particular problem arises when one wishes to pack products deep down in a packing box. With manual packing, this is a comparatively difficult and strenuous operation, for which reason one has tried to use automatic packing for deep-packing of products. These endeavours have not been successful because of the limited space available in the packing box. The fact is that it is extremely difficult to move a product-carrying machine component deep down into the box. Furthermore,

the problem is aggravated by the fact that the products should fill the entire box to the utmost possible extent to prevent them from shaking during transport. Since there is no machine available to solve the above- mentioned problem, deep packing is. at present almost exclusively carried out manually.

The main object of the present invention is therefore to provide a method and a device for automatic packing of products in a container, especially a trough-shaped package, said method and said device having a high production capacity and low labour requirements.

A particular object of the invention is to provide a method and a device for packing products deep down into packing boxes, if desired in several layers. A further object of the invention is that the packing should be carried out hygienically and in a manner which puts a minimum of strain on the workers.

These and other objects that will become apparent from the following description, have been achieved, according to the invention, in that the method described by way of introduction is characterised in that a cloth is stretched between the downwardly directed, free edges of the two walls so that the cloth forms a bottom for the packing means; that the grouped products are fed into the packing means and placed on the stretched cloth; that the packing means, together with the products carried therein by the cloth, is positioned above and thereafter lowered down into the package; that the cloth is loosened and completely pulled away so that the products are placed on the bottom of the package; and that the packing means is lifted out of the package and, finally, returned to the initial position for another cycle.

Furthermore, the invention provides a device of the type described by way of introduction, said device being characterised in that the packing means is down¬ wardly open and has two substantially vertical spaced-

apart walls between which the products can be fed when the packing means is in said feeding position, a cloth being stretchable between the downwardly directed edges of the two walls so as to form a product- carrying bottom for the packing means, the cloth being adapted to be removed when the packing means is in said depositing position.

Preferred embodiments and variants of the method and the device according to the invention are stated in the appended subclaims.

The invention will now be described in more detail, reference being had to the accompanying drawings.

Fig. 1 is a schematic perspective view of a device according to a first embodiment of the invention, including a product-packing means.

Fig. 2 is a view similar to Fig. 1 of the device in its position for feeding previously grouped products.

Fig. 3 is a front view of the packing means during lowering into a trough-shaped package. Fig. 4 is a view similar to Fig. 3, showing the removal of the cloth from the packing means.

Fig. 5 shows the withdrawal of the packing means from the package in which the products remain.

Figs 6-9 are four schematic front views corresponding to each other and showing how the cloth is wrapped round the packing means.

Fig. 10 is a schematic side view of a machine to which the invention according to the first embodiment is applicable. Fig. 11 is a schematic perspective view of a device according to a second embodiment of the invention, including a slightly modified package means.

Fig. 12 shows the device in Fig. 11 in a position just before the products are deposited in a packing box. Figs 1-5 schematically show the packing of products in a packing box by means of a method and a device according to the first embodiment of the invention. The

device includes a rigid packing means 1 which is open downwardly and has two substantially vertical and parallel side walls 2, 3 spaced apart from each other. In the initial position shown in Fig. 1 , a flexible cloth 4 is wrapped round the packing means 1 , a pulling means 5 being fixed to one end of the cloth 4. The device also comprises a clamping means 6 applicable against the outside of the wall 2 for clamping a portion of the cloth 4 therebetween (see Fig. 2). Fig. 2 shows how the cloth 4 has been wrapped further round the packing means 1 to form a bottom 7 therefor. The pulling means 5 is first passed between the wall 2 and the clamping means 6, whereupon the clamping means is applied against the wall 2. In this manner, the cloth 4 is stretched between the downwardly directed edges of the two walls 2, 3 and held against the wall 2 by means of the clamping means 6, while the means 5 exerts a pulling force in the direction of the arrow. This is the product feeding position. The products 8 which here are frozen hamburgers, are grouped in per se known manner in front of the packing means 1 to which they are fed, via guides 10, by means of a feeding means 9 which is of known con¬ struction and therefore not described in detail. Thereafter, the packing means 1 and the products 8 carried therein by the cloth 4 are moved to a product delivering position just above (the dash-dot lines) or inside a container in the form of a trough-shaped package 11 shown in section. Preferably, the packing means 1 is set down on the bottom of the package 11, and the open bottom of the packing means 1 has a shape corresponding to that of the open top of the package 11 , the distance between the walls 2, 3 of the packing means 1 being only slightly smaller than the distance between the corresponding opposing walls of the package 11.

Then the clamping means 6 is loosened, and the

pulling action on the means 5 in clockwise direction is continued until the cloth 4 has been pulled away from the open bottom of the packing means 1 (see Fig. 4) and the products 8 stand on the bottom of the package 11. Evidently, there has to be a certain clearance between the walls 2, 3 of the packing means 1, and the walls and bottom of the package 11, in order to render it possible to pull away the cloth 4 smoothly.

Fig. 5 shows how the packing means 1- and the associated cloth 4 are lifted out of the package 11 without dislodging the products 8 therein. Then, the packing means 1 is taken back to the product feeding position for another cycle.

Figs 6-9 schematically show the use of special means for passing the cloth 4 round the packing means 1. As has been pointed out earlier, one end of the cloth 4 is fixed to the pulling means 5 which, in this embodiment, is connected to the piston rod of a first, vertically positioned piston-cylinder unit 12 which is connected to and movable by means of a second, horizontally positioned piston-cylinder unit 13. Owing to the double action of the piston-cylinder units 12, 13, the cloth 4, during a cycle, is wrapped round the packing means 1 in a path mainly following the circumference of the packing means 1. It should be pointed out that the position shown in Fig. 6 corresponds to the position in Fig. 1 and that, furthermore, the piston-cylinder units 12, 13 are mounted on a trolley (not shown) which follows the packing means 1 when this is moved. Fig. 9 shows schematically how the clamping means 6 can be urged against the wall 2 of the packing means 1 by a further piston-cylinder unit 14 which, however, if this arrangement should interfere with the product delivery, can naturally be positioned elsewhere, for example such that the clamping means is urged against the upper side of the packing means 1.

In deep packing, to which the invention is especially

applicable, the packing cycle may be repeated several times, several layers of products being packed in the package, possibly with the use of interleaving paper (not shown). A machine to which the method and the device according to the first embodiment of the invention is especially applicable, is shown in Fig. 10. The products 8, here in the form of piled, frozen hamburgers, are fed, in the manner described above, to the packing means 1 in which the stretched cloth 4 constitutes the bottom 7 (cf. Fig. 2 ) . Thus, the packing means 1 is in product feeding position.

As is apparent from the arrows, the packing means 1 is then raised and moved horizontally by means of inter alia a piston-cylinder unit 15, to be finally lowered into the product depositing position just above or inside the package 11. The packing means 1 is shown in product depositing position by means of dash-dot lines. This machine for packing hamburgers has been tested in actual practice and turned out to have a production capacity of 200 hamburgers/min, which far exceeds what has been possible hitherto in manual packing. This also gives the hygienic ad¬ vantages mentioned in the introduction. Figs 11 and 12 schematically show a device and a method according to a second embodiment of the invention. The components in Figs 11-12 with counterparts in Figs 1-10 bear the same reference numerals.

In this embodiment, the products 8 which here are assumed to be biscuits, are placed or grouped on the cloth 4 next to the packing means 1 (see Fig. 11). The cloth 4, of which only a portion is shown, is then pulled, on two horizontal plates 16, 17, in a sub¬ stantially horizontal direction with the aid of the means 5. In other words, the means 5 is moved in a direction away from the packing means 1. Between them¬ selves, the two plates 16, 17 define a free space 18

and have, at each opposing longitudinal edge, a rod 19 and 20, respectively, for guiding the cloth 4 (see Fig. 12).

The dome-shaped packing means 1 is downwardly open and has, apart from the walls 2, 3, an upper wall 21 on which three piston-cylinder units are mounted. The central piston-cylinder unit 22 imparts to the packing means 1 a reciprocating vertical motion, while the other two piston-cylinder units 23 are connected to and adapted to move a holding plate 24 which is positioned inside the packing means 1 and whose function will be explained below. One side wall 3 of the packing means 1 is hingedly connected to the upper side 21 and thus can be slightly pivoted, by means not shown, in a direction away from the packing means 1. In this manner, the products 8 placed on the cloth 4 can be fed in under the side wall 3 and into the packing means 1 by the horizontal movement of the cloth 4. When the products 8 are inside the packing means 1 , between the side walls 2, 3 and on the stretched cloth 4, the wall 3 is swung back to its vertical position.

Fig. 12 shows how the packing means 1, together with the products 8 carried therein by the cloth 4, is moved substantially vertically down into a comparatively deep packing box 25 positioned thereunder, the cloth 4 being stretched between the downwardly directed edges of the side walls 2, 3 and forming the bottom 7 of the packing means 1. When the packing means 1 is wholly inside the box 25, the cloth 4 is pulled away in the direction of the arrow in the manner previously de¬ scribed, and the products 8 are deposited on the bottom of the box 25. In order to retain the products 8 when the cloth is pulled away, the holding plate 24 is moved down towards the products 8 by means of the piston- cylinder units 23, and is then retracted. When the products 8 have been deposited in the box 25, the packing means 1 is raised so as to begin another cycle.

The cloth 4 can either be pulled back and forth for each cycle, or pulled in the same direction in a closed path round the place where the packing box 25 is posi¬ tioned. Several layers of products 8 may be packed in the same box 25.

The plates 16, 17 and the associated rods 19, 20 are mounted on a frame (not shown), while the packing means 1 is mounted on a stand (not shown) positioned above said means, and is, as has been mentioned earlier, reciprocable in a vertical direction. Advantageously, one plate 16 and its associated rod 19 are horizontally movable for adjusting the free space 18 to suit different box sizes. The boxes 25 are fed in under the space 18 by hand or by means of known conveyors not forming a part of the invention and therefore not shown or de¬ scribed in detail.

Preferably, the packing means 1 have an external shape corresponding to the inner shape of the box 25. Furthermore, the packing means 1 may be provided with some type of guide means (not shown).

Finally, it should be pointed out that the invention is by no means restricted to the above-mentioned. embodi¬ ments, and that a number of modifications are conceivable within the scope of the appended claims. Some of the method steps according to the invention may, for example, be carried out in another order. Moreover, anyone skilled in the art realises that other means than those de¬ scribed herein can be used for feeding the products into the packing means and for moving the latter, and other means may be used for moving, fastening and stretching the cloth.