GIULIANI, Nicola (Via Tiola 3151/C, Castello di Serravalle, Bologna, I-40050, IT)
PAGANINI, Livio (Via Ramedello 7/1, Corporeno, Ferrara, I-44100, IT)
GIULIANI, Nicola (Via Tiola 3151/C, Castello di Serravalle, Bologna, I-40050, IT)
1. A device for the formation of layers of products to be packaged mutually superposed, comprising:
- a stacking surface movable in a substantially vertical direction, on which the superposed layers of products to be packaged are arranged;
- a pair of substantially superposed conveyors to feed said layers to said stacking surface; characterized in that said movable surface is associated with a compacting wall, positioned approximately orthogonal to the direction of feed of said conveyors and therebelow, the lowering movement of said moving surface carrying the layer or layers deposited thereon approximately to the height of said compacting wall.
2. Device as claimed in claim 1 , characterized in that said compacting wall is provided with a movement towards and away from said moving surface, to facilitate lowering of the moving surface with the layers of product deposited thereon and subsequent compacting of said layers.
3. Device as claimed in claim 1 or 2, characterized in that said conveyors each comprise a sliding surface of the products and members to push the products along said sliding surface. 4. Device as claimed in claim 3, characterized in that said push members comprise bars transverse to the direction of feed of the products. 5. Device as claimed in claim 4, wherein a first of said conveyors comprises double the number of transverse push bars with respect to the other of said push conveyors. 6. Device as claimed in claim 5, characterized in that a first of said conveyors comprises two transverse push bars and the other of said conveyors comprises one transverse push bar.
7. Device as claimed in claim 5 or 6, wherein the lower conveyor comprises two transverse push bars and the upper conveyor comprises only one transverse push bar.
8. Device as claimed in one or more of claims 4 to 7, characterized in that at least one of said conveyors is arranged and controlled so as to compact one or more of said layers of products by means of a movement of at least one of said transverse push bars.
9. Device as claimed in one or more of the preceding claims, characterized in that it comprises at least one moving separator element insertable above said stacking surface, when at least one layer of products is arranged on said stacking surface, said conveyors being controlled so as to position at least a further layer of products on said moving separator which, by moving away, deposits said at least one further layer of products on the layer or layers below previously deposited on said moving surface.
"Improved device for the formation of groups of products in several layers"
DESCRIPTION Technical field
The present invention relates to improvements to machines or devices for the ordered arrangement of products destined for packaging. More in particular, the present invention relates to a device for the formation of mutually superposed layers of products to be packaged, such as rolls of toilet paper, packs of napkins or the like. State of the art In the tissue paper converting industry, to produce for example toilet paper, kitchen towels, paper napkins and handkerchiefs or the like, there is frequently the need to produce packages of several products arranged according to superposed layers. A plurality of superposed layers of rolls, packs of napkins or the like are packaged with heat-sealable plastic films, to form packages destined for sale.
WO-A-2006/134622 discloses devices and methods for the production of groups of three layers of superposed products for packaging. In these devices alignment and compacting of the products formed in single layers is critical, as incorrect alignment of the products causes defects during subsequent packaging or even jamming of the packaging lines downstream of the layering device. Objects and summary of the invention
According to one aspect, the invention provides measures to solve or alleviate the aforesaid problems. In substance, in one embodiment, the invention provides a device for the formation of mutually superposed layers of products to be packaged, comprising:
- a stacking surface movable in a substantially vertical direction, on which the layers of superposed products to be packaged are arranged;
- a pair of substantially superposed conveyors to feed said layers to said stacking surface;
- a compacting wall, positioned approximately orthogonal to the direction of feed of the conveyors and thereunder, in a position such that the lowering movement of the moving surface carries the layer or layers deposited thereon approximately to the height of the compacting wall,
so that the products interacting with the compacting wall are correctly ordered or compacted.
According to some embodiments, the compacting wall is provided with a movement towards and away from the moving surface, to facilitate lowering of the moving surface with the layers of products deposited thereon and subsequent compacting of said layers.
Further advantageous features and embodiments of the invention are described below with reference to examples of embodiment and are defined in the appended dependent claims. Brief description of the drawings
The invention will be better understood by following the description and accompanying drawing, which shows non-limiting practical embodiments of the invention. More in particular, in the drawing:
Figures 1 to 3 show an operating sequence in a simplified schematic representation of the device according to the invention in side view; and
Figure 4 shows a schematic front view according to IV-IV of Figure 3. Detailed description of embodiments of the invention
The present invention can be incorporated in a device designed and controlled as described in WO-A-2006/134622, which should be referred to for greater details, for the part not described in the present specification, which is limited to the innovative and characterizing aspects of the present invention.
With reference to the accompanying figures, the device, indicated as a whole with 1 , includes a stacking surface 3 movable vertically according to the arrow f3 (Fig. 2). A fixed stop wall 5 is associated with the stacking surface to define the position of complete insertion of layers S of products P, in the example illustrated formed by way of example of rolls of toilet paper or the like.
In the example illustrated, three layers, indicated with S1, S2, S3, are arranged on the stacking surface 3, each comprising four rows of three products P. However, it must be understood that other configurations are possible, with a different number of products for each layer and also, if necessary, a different number of mutually superposed layers.
To stack the layers S1, S2, S3 on the vertically movable stacking
surface 3 the device includes a pair of substantially superposed conveyors: a first lower conveyor 7 and a second upper conveyor 9. A sliding surface 7A is associated with the lower. conveyor 7, along which the layers S of products P are pushed by means of the conveyor 7. For this purpose, the conveyor 7 has transverse push bars 7B, 7C. In a practical embodiment the conveyor 7 is formed by two endless flexible members substantially parallel and distanced by a degree sufficient to contain therebetween the layers to be stacked and which support the transverse push bars 7B, 7C.
The upper conveyor 9 has a similar structure, with a sliding surface 9A and with a single push bar 9B carried by two endless flexible members (for example a belt or a chain) which form the conveyor 9.
A compacting wall 11 , extending substantially vertically, is arranged under the sliding surface 7A of the lower conveyor 7. In some embodiments, the compacting wall 11 is provided with a movement according to the arrow f11 (Figure 2).
Finally, for the part of interest in the present description, the device 1 comprises (see Figure 4) a separator element that serves to temporarily separate superposed layers of products P during the stacking process. In some embodiments of the invention, the separator element comprises two surfaces 13A, 13B carried by slides 15A, 15B movable according to the double arrows f15A and f15B along guides 17A and 17B. The movements of the stacking surface 3, of the compacting wall 11 , of the conveyors 7, 9 and of the surfaces 13A, 13B are obtained with actuators of conventional type, not shown. The operating cycle of the device described above is clearly understood by examining the sequences of Figures 1 to 3. To obtain a package of three mutually superposed layers S1 , S2, S3 of products P, in a first step (Figure 1) the lower conveyor 7 pushes, by means of the pusher or push bar 7B, a first layer of products P onto the surface 3. This surface is located at a height approximately corresponding to the height of the front edge of the sliding surface 7A. Once the layer S1 has been placed on the stacking surface 3 the latter is lowered (arrow f3) to take the position in Figure 2. Lowering of the stacking surface 3 preferably takes place with the compacting wall 11 in the position of Figure 1 , i.e. distanced from the volume inside which the stacking
surface 3 moves. This facilitates downward movement of this surface preventing interference between the compacting wall 11 and the products P positioned on the stacking surface 3. However, it would also be possible for the wall 11 to abut on the stacking surface 3, carrying it to the position it takes in Figure 2, even before lowering of the stacking surface 3. According to other embodiments, the compacting wall 11 is not movable and is located in the position of Figure 2. In this case, it is advantageous to provide an inclined upper portion of the wall 11 (also indicated in Figures 1 to 3 with 11 A, as this is advantageous also in the case of movable wall 11), to facilitate lowering of the stacking surface 3 and of the layer S1 of the products positioned thereon in the first step of the operating cycle.
Before, during or after lowering of the stacking surface 3 from the position of Figure 1 to the position of Figure 2, the two conveyors 7 and 9 have pushed a second layer S2 and a third layer S3 of products P into an intermediate position along the sliding surfaces 7A, 9A, by means of the transverse bar 7C of the conveyor 7 and the transverse bar 9B of the conveyor 9 respectively. The layers of products are fed to the conveyors 7, 9 in a known manner by means of an oscillating conveyor belt or other suitable device, not shown. In the subsequent step, the movement of the conveyors 7, 9 pushes the layers S2, S3 towards the stacking surface 3, obtaining superposing of the three layers S1 , S2, S3 on this surface. The position of maximum feed of each of the three layers is defined by the wall 5.
In some embodiments, before simultaneously pushing the layers S2, S3 onto the stacking surface 3, the separator surfaces 13A, 13B are moved from an idle position (indicated with a dashed line in Figure 4) to an operating position, shown with a solid line in Figure 4. In this way the layer S2 is pushed by the bar 7C by means of the conveyor 7 onto the separator surface formed by the surfaces 13A, 13B moved towards each other, thereby preventing direct sliding of the layer S2 on the layer S1 below. As the two conveyors 7, 9 move in synchronism, no sliding occurs between the two layers S2 and S3, and therefore no separator surface is required therebetween.
The arrangement described above achieves the advantage of compacting the products P of the lower layer S1 and maintaining them in the
ordered arrangement due to the fact that they are contained between the wall 5 and the compacting wall 11. Laterally, the products P of the layer S1 are held by lateral walls 19A, 19B (Figure 4). The products P of the layers S2, S3 above are retained laterally by containing walls 21 A, 21 B forming the continuation of the walls 19A, 19B. In actual fact, the walls 19A, 21 A and 19B, 21 B respectively can be mutually integral, i.e. formed only by two opposite walls, each suitably interrupted or slotted to allow passage of the separator elements or surfaces 13A, 13B. In some embodiments, the separator elements or surfaces can have a comb structure to . penetrate through the lateral walls, which can therefore have a structural continuity between lower portion 19A, 19B and upper portion 21 A, 21 B.
In some embodiments, after reaching the position of Figure 3, when the separator surfaces 13A, 13B are returned to the idle position (dashed line in figure 4) and the stacking surface 3 is lifted to take the superposed layers S1 , S2, S3 to a packaging position above (not shown), the conveyors 7, 9 can be controlled with an alternating movement so that the push bars 7C, 9B oscillate around the end position shown in Figure 3.
In this way, these push bars 7C, 9B form a compacting element of the products P of the layers S1 , S2, S3 preventing the risk of accidental movement of the products P during the lifting steps towards the packaging position above.
Likewise, the push bar 7B acts as compacting element at the moment (shown in Figure 1) in which the layer S1 is lowered to the lower level (Figure 2) in contact with the compacting wall 11. It is understood that the drawing only shows an example provided purely by way of practical demonstration of the invention, which can vary in forms and arrangements without however departing from the scope of the concept underlying the invention. Any reference numbers in the appended claims are provided to facilitate reading of the claims with reference to the description and to the drawing, and do not limit the scope of protection represented by the claims.
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