The invention relates to a method for packaging relatively vulnerable products, in particular loaves of bread, into bags, comprising the steps of supplying bags, successively opening the bags, supplying products and successively filling the bags with the products. Such a method is known in different variants, and is applied particularly for packaging loaves of bread baked in large-scale bread factories.

Bread is continuously being baked in such factories, wherein loaves are usually transported through an oven in baking trays. After leaving the oven and being released from the baking trays, the loaves are generally first sliced and then packaged. Examples of earlier proposed mechanized slicing and packaging methods and the equipment to be employed therein can be found in the older patents WO 01/64520 Al, EP 0 542 336 Al, NL 1001892, NL 9300420 and NL 8401833.

It is usual for the loaves to be transported successively in transverse direction to a vertical slicer frame which is movable up and downward. The loaves are forced through this slicer frame, wherein they are cut into slices. A set of band slicers can otherwise also be used instead of a slicer frame. The sliced loaves are then transported to a location where a stack of bags is situated. Here one of the bags at a time is opened, after which one of the loaves is pushed therein in longitudinal direction. Opening of the bags is generally performed by mechanical or pneumatic means, while the loaves are pushed in longitudinal direction into the bags by means of a pusher member. The bag can here be held fast and the loaf of bread pushed, or the loaf held fast and the bag pulled thereover. Reference in this text to sliding products into bags is expressly understood to include both these options.

The known mechanized packaging method has the significant drawback that it requires a relatively large number of operations and cannot therefore always be performed quickly enough. Placing the loaf into the bag is in fact a discontinuous operation not readily compatible with the continuous baking process. It must be remembered here that industrial ovens currently have a capacity in the order of more than 3000 loaves per hour, but that in newer ovens this capacity amounts to more than 4000 loaves per hour. This means that the packaging of a loaf must be completed within a second when it is done in line with the oven. Pushing of the loaf into the bag must therefore take place at ever increasing speed. Because freshly baked loaves are still relatively soft however, they are not very easy to handle .

Another problem is associated with taking from the stack and opening the bags. Because they are thin and limp, these are not easy to handle either, whereby it is difficult to open the bags in reliable and reproducible manner. In addition, the bags may adhere to each other as a result of friction, whereby more than one bag at a time is taken from the stack.

This combination of factors results more and more frequently in malfunction, for instance because a bag is not opened quickly enough and the loaf is pushed against the edge of the bag. The slices of bread will then fall apart in the machine. With some types of bread the wastage can in this way amount in practice to more than 10%. This problem occurs particularly in the case of incised loaves which have an irregular peripheral form.

Slicing of the loaves often also results in problems. Upstream of the slicer frame the loaves are thus often pressed together due to the resistance at the position of the slicer frame, while downstream of the slicer frame they often fall apart as a result of the sudden acceleration at that position. These problems also increase as the speed at which loaves are supplied increases. And these problems also occur more frequently in the case of incised loaves .

The invention now has for its object to provide a method for mechanized packaging of relatively vulnerable products, such as loaves of bread, into bags, wherein these drawbacks do not occur or at least do so to lesser extent. According to a first aspect of the invention, this is achieved in a method as described above in that the bags and the products are transported substantially parallel to each other over a determined distance, and during this parallel transport the products are gradually pushed substantially transversely of the direction of transport into the bags. By transporting the products and the bags over a distance adjacently of each other, space and time are created in the line to carry the products gradually into the bags, so at relatively low speed in relation to each other.

The bags are preferably supplied in the form of a double foil strip, and are welded and cut prior to filling thereof with the products. By thus producing the bags in the line problems with separating the bags, which occur when they are supplied in stacks, are avoided.

A rapid and effective manner of opening the bags is achieved when each bag is opened by inserting a pair of blades therein and subsequently moving the blades apart.

The or each pair of blades is here advantageously inserted into the double foil strip prior to the welding and cutting and displaced synchronously with respectively the foil strip and the bags in the direction of transport. There is thus sufficient opportunity to fully open the bags in reliable manner.

When each product is pushed by a pusher member into the bag, this pusher member is preferably displaced synchronously with respectively the bags and products in the direction of transport .

It is recommended that, after sliding of the product into the bag, first the pair of blades and then the pusher member are withdrawn from the bag. In this way the bag is pulled optimally round the product.

According to a second aspect, the invention provides a packaging method wherein each product is cut into a number of slices prior to packaging by placing the product with one side on a carrier and urging a slicing member from an opposite side toward the carrier. The products being compressed or falling apart is prevented by no longer transporting the products through a slicing member but by supporting them during the slicing. When each product is divided into two halves with a substantially equal number of slices after the slicing and the product halves are individually packed, half loaves of bread can also be supplied in addition to full loaves.

In order to enable application of the discontinuous slicing operation in an otherwise continuous production line, it is recommended that a number of products are simultaneously sliced and optionally divided, and the sliced products or product halves are successively packed.

The invention also relates to a device for packaging relatively vulnerable products, in particular loaves of bread, into bags, comprising means for supplying bags, means for opening the bags, means for supplying products and means for filling the bags with the products . Such a packaging device is likewise known, for instance from the above-mentioned older patents.

The invention has for its object to develop such a device such that the above described method can be performed therewith. According to a first aspect of the invention, the device is provided for this purpose with means for transporting the bags and the products substantially parallel to each other over a determined distance, wherein the filling means are adapted to gradually slide the products substantially transversely of the direction of transport into the bags during this parallel transport . The device can comprise at least one pair of blades and at least one pusher member which can be displaceable synchronously with the bags in the direction of transport. In a preferred embodiment of the device the at least one pair of blades and the at least one pusher member are connected for this purpose to the transport means.

The device is preferably further provided with stationary guide means placed along the transport means and co-acting with the at least one pair of blades and the at least one pusher member. The pair of blades and the pusher member are moved in the correct manner toward and away from the bags by these guide means during transport.

The guide means advantageously comprise at least one guide for the at least one pair of blades and at least one guide for the at least one pusher member, so that the blade pairs and the pusher members can perform movements of their own.

According to a further preferred embodiment of the device, the transport means comprise an endless, circulating, driven transport element carrying a number of blade pairs and pusher members, wherein the blade pairs and pusher members form in each case a set and are distributed uniformly over the transport element. A large number of bags can thus be simultaneously opened and filled with products.

Further preferred embodiments of the device according to the invention form the subject matter of the sub-claims. The invention will now be elucidated on the basis of an example, wherein reference is made to the accompanying drawing, in which: Fig. 1 shows a schematic perspective top view of the actual packaging line of a packaging device according to the invention,

Fig. 2 shows a view corresponding to fig. 1 from another angle ,

Fig. 3 and 4 show respectively a top view and a side view of the packaging line of fig. 1 and 2,

Fig. 5A and 5B together represent a schematic top view of the whole packaging device, including the slicing line, during slicing and packaging of full loaves,

Fig. 6A and 6B show a view corresponding to fig. 5A and 5B of the device during packaging of half loaves.

Fig. 7A to H show schematically the different steps of opening, filling with a product and then closing a bag, Fig. 8 shows a side view according to arrow VIII in fig. 5A, and

Fig. 9 shows a side view according to arrow IX in fig. 6A.

A device 1 for packaging relatively vulnerable products 3 , in particular loaves of bread, into bags 2 comprises means

4 for supplying bags 2, means 5 for opening the supplied bags

2, means 6 for supplying products 3,- and means 7 for filling bags

2 with products 3.

In the shown example the bag supply means 4 comprise a supply holder or roll 8 on which a double folded foil strip 9 is wound. In addition, bag supply means 4 comprise downstream of supply roll 8 a welding member and a cutting member, which in the shown example are combined to form a single welding and cutting station 10. Supply roll 8 is supported by two rollers 11, 12, while the first part of foil strip 9 is carried by a first foil conveyor 15 trained round two reversing rollers 13, 14.

At the position of welding and cutting station 10 the foil strip is transferred from a second foil conveyor 16, which is likewise trained round two reversing rollers 17, 67, to a third foil conveyor 69 trained round two reversing rollers 18, 68. The second and third foil conveyors 16, 69 each have in addition a circulating part trained respectively round auxiliary rollers 19, 20 and 21, 22. Reversing rollers 67, 68 and auxiliary rollers 19-22 and the circulating parts are here movable so that the position of welding and cutting station 10 can be adjusted to a desired speed. By setting a transport speed of the third foil conveyor 69 which is higher than that of the second foil conveyor 16 bags 2 are separated from each other after the welding and cutting .

Foil conveyors 15, 16, 69 further have a vacuum provision, whereby respectively foil strip 9 and bags 2 are held fast on these conveyors 15, 16, 69. The first and second foil conveyors 15, 16 can otherwise be combined to form a single conveyor .

Connecting to foil conveyors 15, 16, 69 is a conveyor 36 trained round two reversing rollers 37, 38. Using this conveyor 36, which is embodied as a conveyor belt with a number of catches thereon, bags 2 are discharged after being filled with products 3. Arranged above this discharge conveyor 36 are means 42 for at least partially closing the filled bags 2, here in the form of two parallel rods 43, 44 which are placed one above the other and the upper rod 43 of which has on the upstream side an infeed segment running obliquely downward.

According to the invention the device is provided with means 23 for transporting bags 2 and products 3 substantially parallel to each other over a determined distance. In addition to foil conveyors 15, 16, these parallel transport means 23 comprise a conveyor 24 for products 3. This conveyor 24 is embodied here as chain conveyor having a number of carriages 25 on which products 3 are transported. In addition to carriages 25, conveyor 24 also carries a corresponding number of blade pairs 26 which form part of bag opening means 5. These blade pairs 26 are movable transversely of the direction of movement of conveyor 24 so that they can be inserted into and again withdrawn from bags 2. In addition, blades 26A, 26B of each blade pair 26 can be moved apart in order to open bags 2.

Finally, conveyor 24 also carries a number of pusher members 27 corresponding to the number of carriages 25 and blade pairs 26, and forming part of filling means 7. In the shown example these pusher members 27 are likewise movable transversely of the direction of movement of conveyor 24 , and are adapted to slide products 3 gradually into bags 2 during the parallel transport. Placed along conveyor 25 for the purpose of controlling the movements of blade pairs 26 and pusher members 27 are stationary guide means consisting of a first guide 28, which co-acts with blade pairs 26, and a second guide 29 which co-acts with pusher members 27. These guides 28, 29 circulate just as conveyor 24. Second guide 29 for pusher members 27 runs at the position of the active part of conveyor 24 parallel to the transport plane defined thereby. Conversely, first guide 28 for blade pairs 26 has an obliquely rising part 30, an elevated part 31 and an obliquely descending part 32, whereby blades 26A, 26B can be moved away from and toward each other. For the purpose of controlling the movements with which blade pairs 26 are inserted into and once again withdrawn from bags 2, first guide 28 further has a part 33 running obliquely toward foil conveyors 15, 16, a part 34 lying above these conveyors and a part 35 running back at an angle. In similar manner second guide 29 has a part 39 running obliquely toward discharge conveyor 36, a part 40 located close to this conveyor and a part 41 running back at an angle, with which pusher members 27 can be slid into and once again withdrawn from bags 2.

The operation of the packaging device 1 described up to this point is as follows. The double folded foil strip 9 is unwound from supply holder 8 by bag supply means 4. While this strip is moving over foil conveyors 15, 16 it is opened in that a blade pair 26 is inserted therein from the side 47 located opposite fold line 46. In the shown example this insertion begins roughly at the position of the transition between the two foil conveyors 15, 16. When these conveyors 15, 16 are embodied as a single continuous foil conveyor, the insertion begins roughly halfway along this conveyor. The insertion movement is controlled by the inclining part 33 of first guide 28, along which an arm 45 of upper blade 26B runs. The later opening of the bag is simplified by inserting blade pair 26 into foil strip 9 when it is still relatively easily accessible.

Once blade pair 26 has been inserted fully into foil strip 9, a product 3 is placed by product supply means 6 onto carriage 25 between blade pair 26 and pusher member 27 (fig. 7A) . Foil strip 9 is then closed by welding at two positions in transverse direction between fold line 46 and open side 47 in welding and cutting station 10, and is severed between the two welded joins. A bag 2 is thus formed. Problems with separating of the bags are avoided by forming bag 2 in the line instead of supplying the bag on a stack.

Bag 2 is then opened by moving upper blade 26B upward relative to lower blade 26A (fig. 7B) . This upward movement is controlled by the obliquely rising part 30 of first guide 28. Upper blade 26B is then held up in that its arm 45 runs along the elevated part 31 of first guide 28.

Product 3 is then pushed off carriage 25 by pusher member 27 into the bag 2 which is being held open (fig. 7C) . This sliding movement is controlled by the inclining part 39 of the second guide along which runs the free end 48 of pusher member 27. This sliding movement ends as soon as the end 48 of pusher member 27 reaches the straight part 40 of second guide 29 {fig. 7D) . The angle of inclining part 39 of second guide 29 thus determines how quickly the product 3 is pushed into bag 2. A gradual sliding movement can be achieved by making this angle quite small, thereby reducing the risk of malfunction.

The blade pair 26, still in the opened position, are then withdrawn from bag 2 (fig. 7E) . This withdrawal is controlled by the obliquely descending part 35 of first guide 28. Pusher member 27 remains in the extreme position and holds product 3 fixedly in bag 2. The open side of bag 2 is then guided between the two rods 43, 44 of closing means 42, whereby the bag is pinched closed to some extent {fig. 7F) . The product is in this way stabilized to some extent.

Pusher member 27 can then be safely withdrawn from bag 2 {fig. 7G) in that its free outer end 48 runs along the part 41 running back at an angle of second guide 29. Finally, blade 26B is moved downward again onto blade 26A (fig. 7H) in that its arm 45 moves along the obliquely descending part 32 of first guide 29. Carriage 25, blade pair 26 and pusher member 27 are then returned by the circulating conveyor 24 to the beginning of the line, where the cycle is repeated. Packaging 2 with product 3 therein is finally guided along a closing station 66 and there closed with a clip.

Packaging device 1 is further provided here with means 49 for cutting each of the products 3 placed upstream of product supply means 6 into a number of slices or cut portions 50. According to the invention these slicing means 49 comprise a carrier 51 which supports products 3 on one side and which is embodied in this case as a conveyor trained round reversing rollers 56. In addition, slicing means 49 according to the invention comprise a slicing member 52 movable from an opposite side, so here from above, toward the carrier or conveyor 51. This slicing member 52 is formed here by a framework 53 in which a large number of knives 54 are mounted in longitudinal direction, so in the direction of transport of carrier/conveyor 51. Slicer frame 53 is also movable reciprocally in longitudinal direction, whereby the products placed thereunder are as it were sawn through.

Because slicing means 49 according to the invention do in fact operate discontinuousIy, in contrast to the prior art vertical slicer frames, they are adapted to process multiple products 3 at a time. In the shown example slicer frame 53 is dimensioned such that six products 3 transported spaced apart on carrier 51 fit within the frame. Carrier/conveyor 51 is adapted to carry six products 3 at a time below slicer frame 53 and to then remain stationary during slicing. Products 3 are transported on carrier 51 in compartments defined by upright walls 55. Arranged in these walls 55 are recesses in which knives 54 can move. Products 3 are thus also supported optimally during slicing. This slicing method results in considerably less damage and wastage of products 3 and to fewer malfunctions than the conventional method of slicing using a vertical slicer frame through which the products press each other.

Products 3 for slicing are carried to carrier 51 by a feed conveyor 57 and a vertical feed unit 58. Once products 3 have been sliced with knives 54 to form a number of slices or cut portions 50 and slicer frame 53 has been moved upward again, the sliced products 3 are carried further to a transfer end 59 of carrier/conveyor 51 which functions as a buffer. Conveyor 51 here again comes to a stop, after which the six sliced products 3 are taken by product supply means 6 from transfer end 59 and transferred to the six carriages 25 of conveyor 24 which are free because the associated blade pair 26 is inserted in foil strip 9. In the shown example product supply means 6, which can for instance comprise a number of grippers corresponding to the number of products 3, are for this purpose pivotable about a longitudinal axis 60 which runs parallel to the direction of transport of conveyors 51 and 24. Product supply means 6 are simultaneously displaceable along this axis 60 in order to carry products 3 from the stationary transfer end 51 to the moving carriages 25.

Finally, packaging device 1 is further provided with means 61 for dividing each sliced product 3 into two halves 62 with a substantially equal number of slices 50. These dividing means 61 are placed between slicing means 52 and product supply means 6. In the shown example dividing means 61 comprise a pair of adjacent, individually movable conveyors 63, 64. These two individually movable conveyors 63, 64 can for instance be substituted for transfer end 59 of carrier 51. Walls 65 defining compartments for receiving the sliced products 3 therefore take a divided form so that the product halves 62 are properly supported during the relative movement of conveyors 63, 64. Sliced products 3 are easily divided into two halves 62 by for instance moving conveyor 63 through a short distance, such as the distance between two walls 65, and stopping the other conveyor 64. These halves 62 can then be taken from the relevant conveyor 63, 64 by product supply means 6 and transferred to the corresponding carriages 25 of conveyor 24 of filling means 7. This transfer will of course then take place in two steps, so that slicing means 49 then stop for a time while both conveyors 63, 64 are emptied.

Bag supply means 4, bag opening means 5 and filling means 7 are of course adapted in this case to the smaller dimensions of product halves 62. The first and second guides 28, 29 can for instance thus be displaced or be replaced by other models. The invention thus makes it possible in rapid and reliable manner to package relatively vulnerable products, such as loaves of bread, into packages which are relatively difficult to handle. In addition, the invention enables careful slicing of these products prior to the packaging. Furthermore, there is considerably less waste than is usual in the prior art.

Although the invention has been elucidated above on the basis of an example, it will be apparent that it is not limited thereto. Form, dimensions and number of the different components of the shown packaging device can thus be varied in many ways . The different new aspects of the invention can also be applied in many combinations while retaining the associated advantages. The scope of the invention is therefore defined solely by the following claims.