Device for forming groups of articles in cartoning machines and the like

Abstract: A device that builds up regular groups (20) of articles (2) includes gripping means (7) for picking up a row of articles (2) fed along a conveyor (5), in the region of a pick-up station (4). A robotic unit (15) controls the movement of the gripping means (7), along two perpendicular axes, and on a vertical plane transversal to the conveyor (5), so as to transfer the row of articles (2) picked up into a grouping frame (21) located in a station (10) where a regular group (20) of articles (2) is built up. A pushers (27) and the grouping frame (21) together delimit a space where a regular group is built up by subsequent placements of rows of articles (2).

Description: The present invention relates to packaging articles in cardboard containers, obtained from tubular blanks. Machines according to the preamble of claim 1 are known for forming regular groups of articles which are then introduced into containers, see e.g. WO-A-95/05312. In a further known solution, the group of articles to be introduced in the container is formed by subsequent downward article placements on a horizontal plate, moving vertically and located downstream of an articles feeding line. A device that operates in this way, as described in the US-A-4.551.052, includes a station provided with two rollers having longitudinal face millings, in the region of which relative plates are fixed; in a rest position the two plates form a channel that receives articles. Inside the channel there are means for detecting the formation of a layer of articles placed close to one another. When one layer is formed, the above mentioned rollers make a full turn in counter-rotating directions and transfer the layer to the plate below, or on top of the upper layer of the pile being formed on the same plate. According to another known solution, described in the US-A-5.116.195, the articles coming one by one from a horizontal feeding line are moved downwards to a plate supporting a pile of articles that is formed by such vertical translation. This pile is then moved horizontally by suitable convey means equipped with a frame, that can perform a series of strokes of limited length in order to bring a certain number of piles close to one another, and subsequently a longer stroke to transfer the so formed group of piles. Then this group is moved in a transversal direction by suitable packing means. In yet another solution a group of articles is formed proceeding upwards, beginning from a feeding station, in which a row of articles is formed; this row is subsequently raised by an elevator, situated below, until it is placed on suitable supports. The next row being raised strikes the previous one and raises it again. In this way, a pile of articles is built up by subsequent placement of layers on the said supports. Upon completition of the pile, a pusher moves it onto a fixed platform; the next pile transferred to the platform moves the previous one and others possibly present there. When a predetermined number of piles, brought close one to another, has been reached, the group is introduced into a container suitably positioned on the side of the platform. A device of this type is illustrated e.g. in the IT-B-208.806. The above mentioned solutions are considerably complex under both constructive and functional points of view, and usually also their dimensions are very big. A considerable drawback of the above mentioned solutions derives from the fact that the piles of articles forming the group to be introduced into the container and the same group are not stable during the necessary working steps. In fact, the articles arranged in piles simply rest on a base plane or at the most they rest against a lateral plane. This can make difficult the subsequent step of introducing the articles into the container. The object of the present invention is to provide a device that allows building up of regular groups of articles and subsequently, introduction of these groups of articles into respective containers, ensuring high throughput and stability of the same groups during different working steps. The above mentioned object is obtained in accordance with the contents of the claims. The characteristic features of the present invention are pointed out in the following description with reference to the enclosed drawings, in which: fig. 1 shows a lateral schematic view of a cartoning machine equipped with the device for forming regular groups of articles; fig. 2 shows a correspondent plan view of the same machine, during a subsequent working step; fig. 3 shows a transversal section of the device, taken along the plane III-III of fig. 1; figs. 4 and 5 show the same transversal section of the subject device, in subsequent working steps. With reference to the above mentioned figures, a cartoning or the like machine is equipped with a device for forming regular groups of articles 2, indicated with numeral 1. The articles 2 are fed one by one to a pick-up station 4 by conveying means 5, e.g. a belt conveyor; the articles 2 conveyed on the belt 5 stop when they strike a fixed shoulder 6, suitably positioned, as pointed out in the following. The device 1 features gripping means 7 equipped with suction elements 8, like suction cups, aimed at picking up a row of articles 2 from the conveying belt 5 and transferring them onto a plate 9, situated horizontally in a station 10, in which a regular group of articles 2 is built up and then introduced into a container 11. Beside this group building up station 10 and in the region of a line 14 for conveying filled containers, there is a station 12 for setting up blanks 13 into containers 11. The plate 9 is in fact co-planar with the lower wall of the container 11 each time situated in the opening station 12. The gripping means 7 are controlled by a robotic unit 15 that drives movements thereof along two perpendicular axes, on a vertical plane transversal to the conveying belt 5. The robotic unit 15 includes a vertical bar 16, the lower part of which carries a plate 17 supporting the suction cups 8; virtually, the suction cups 8 are arranged in pairs, turned downward, along the plate 17 so as to engage a row of articles on the conveying belt 5. The bar 16 runs through a slide 18, joined with a grooved guide 19 that extends transversally to the conveyor belt 5, on a horizontal plane over the same belt 5. In the region of the said station 10, over the plate 9, the device 1 features a grouping frame 21 from which a group of articles can be easily transferred into the container 11. The grouping frame 21 is opened at its top for insertion therein of the rows of articles 2, and is also opened on the side opposite to the container 11 to be filled, that means also opposite to the station 12. In particular, the grouping frame 21 includes a pair of lateral walls 21a and features, on the side close to the container 11, transversal walls 21b slightly convergent so as to form a lead-in section for the same container 11. One of the internal lateral walls 21a of the grouping frame is in alignment with an abutment surface 6a of the fixed shoulder 6. The grouping frame 21 slides on the plate 9, in horizontal direction, transversal to the conveying line 14, and is operated by a reciprocating device 22 including an oscillating arm 23 articulated to a carriage 24 that slides in a guide 25 in the said transversal direction; the carriage 24 is integral with a bar 26 fastened to the grouping frame 21. In practice, the grouping frame 21 moves between a position, in which the group of articles 2 is formed over the plate 9, and a position, shifted toward the container 11, in which the same group of articles is introduced into the said container 11. Moreover, the device 1 features a pusher 27 constituted basically by a vertical plate that forms an additional wall of the grouping frame 21, extending from the side opposite to the one facing the container 11, when the grouping frame is in the position where the group of articles 2 is formed. The pusher 27 is moved in the said horizontal direction, transversal to the conveying line 14, by a reciprocating device 28 including an oscillating arm 29 articulated to a carriage 30 that slides in a guide 31; the carriage 30 is integral with a bar 32 fastened to the pusher 27. The plate 9 is carried by a reciprocating operation device 33, that controls movements of the plate in the vertical direction. This operation device 33 allows adjustments of the vertical position of the plate 9, in particular during size change-over. The operation device 33 can be used also to control vertical movement of the plate 9 in phase relation with building up of the group of articles 2 inside the grouping frame 21. In this way, the plate 9 can be lowered stepwise from the highest position in registry with the layers of the articles 2 being formed in succession inside the grouping frame 21. Operation of the device will be described beginning from the step, in which a row of articles 2 is picked up from the conveying belt 5 (Fig. 1). During the picking up step the gripping means 7 are situated over the above mentioned row of articles 2, in the pick up station 4. In order to pick up the articles, the gripping means 7 are lowered, thus bringing the suction cups 8 to contact the articles 2, as seen in Fig. 3. Subsequent raising of the gripping means 7 raises also the articles 2. The lowering and raising of the gripping means 7 are determined by the vertical sliding of the bar 16 of the robotic unit 15. Subsequent movement of the slide 18 of the robotic unit 15 along the guide 19 brings the gripping means 7 to the station 10, in which a regular group of articles 2 is formed, as seen in Figs. 2 and 3. At this point, the gripping means 7 are lowered again so as to insert the articles 2 into the grouping frame 21, as shown in Fig. 3, where the broken line 7a indicates the position assumed by the gripping means 7 during this step. In fact, the row of articles 2 is put inside the space delimited by the lateral walls 21a of the grouping frame 21 and by the pusher 27, adjacent thereto. Likewise, next rows of articles 2 are transferred into the grouping frame 21 and progressively arranged one beside another and the layers of articles are put one on another. This subsequent placement of the rows of articles 2 builds up a regular group, for the sake of clarity indicated with 20. It is to be pointed out that during the building up step, the group 20 is guided on three consecutive sides delimited by the lateral walls 21a of the grouping frame 21 and by the pusher 27, adjacent thereto. When the regular group 20 of articles has been formed, the grouping frame 21 and the pusher 27 are simultaneously driven to translate toward the motionless container 11 located in the station 12 of the conveying line 14; this rotation is operated by rotation of the relative oscillating arms 23,29 that control movement of the carriages 24,30 along the guides 25, 31 (Fig. 4). In this way the grouping frame 21 is positioned so as to form a lead-in section for the same container 11. The bottom and top wings of the container 11 are open and the container is ready for the introduction of the group 20 of articles 2. Obviously, the translation of the grouping frame 21 and the pusher 27 determines the movement of the regular group 20 of articles 2 formed inside the same grouping frame 21. After having reached the advanced position in which the group 20 is introduced, the grouping frame 21 stops while the pusher 27 continues its forward movement, thus causing translation of the group 20 with respect to the grouping frame (Fig. 5). Then, the group 20 is pushed inside the container 11. When the container 11 has been filled with the articles 2, the grouping frame 21 and the pusher 27 return to the group building up position. The container 11 filled with the articles 2 is carried forward by the conveying line 14 to undergo subsequent packaging steps. Consequently, the proposed device allows to form regular groups of articles and subsequently introduce them into relative containers in a very simple way. In fact, these operations are carried out by gripping means operated by mechanisms working with a combination of straight movements, with a high throughput. Moreover, this allows to facilitate change-over of the device in relation to different sizes of the containers to be filled. An important feature of the described device is that it ensures stability of the formed groups of articles during different working steps. Actually, the groups of articles are formed by subsequent placements into the grouping frame, from which they are then introduced into respective containers, without intermediate movements. Moreover, during the regular group forming step as well as during the step of their introduction to the container, these groups are guided on three sides by the said grouping frame and a relative pusher. The reduction of different working stations results also in a smaller size and bigger operation speed, as well as in constructive and functional simplicity. In the embodiment illustrated in the enclosed figures, the robotic unit 15 moves the gripping means 7 along two perpendicular axes, and to be more precisely, on a vertical plane transversal with respect to the conveying means 5; this is possible due to the fact that the abutment surface 6a, which is in alignment with the lateral internal wall 21a of the grouping frame, does not need to be moved longitudinally, i.e. in the direction defined by the conveying means 5. It is understood that this is an advantageous simplification not a limitation, because nothing prevents the robotic unit 15 from having also another longitudinal axis perpendicular to both previously mentioned axes. Alternatively, the suction cups 8 can be substituted by pliers that grip laterally the row of articles 2; obviously these pliers must not change reciprocal positioning of the articles. Moreover, by using suction cups or pliers, it is possible to pick up two or more rows of articles arranged side by side or two or more rows of articles put one on the other.

Claims: Device for forming regular groups (20) of articles (2) in cartoning machines (3) or the like, including gripping means (7) designed to pick up at least one row of articles (2) fed by conveying means (5) to a pick up station (4) and to transfer the at least one row of articles to a grouping station (21, 27); characterised in that it further includes a robotic unit (15) for controlling movement of the said gripping means (7) along two perpendicular axes and on a vertical plane transversal to the said conveying means (5), for transferring the row of articles (2) into a grouping frame (21), located in a group building up station (10), in which a regular group (20) of articles (2) is built up; a pusher (27) cooperating with the said grouping frame (21) for delimiting a space in which said regular group (20) of article (2) is formed by subsequent placements of rows of the said articles (2), and for introduction of the same group (20) of the articles (2) into a container (11). Device, according to claim 1, characterised in that the said gripping means (7) feature suction means (8) supported by the lower part of a bar (16) of the said robotic unit (15) sliding vertically on a slide (18) movable on a guide (19) that extends transversally to the said conveying means (5), for reciprocating motion of the same gripping means (7) between the said pick up station (4) and the said group building up station (10). Device, according to claim 1, characterised in that the said grouping frame (21) is opened at the top for introduction thereinside of the said rows of articles (2), as well as at the side opposite to side facing the said container (11) to be filled, with the said pusher (27) situated in the region of said opened side. Device, according to claim 1, characterised in that the said group building up station (10) includes a plate (9) defining the base of the said grouping frame (21) and the support for the said group (20) being formed. Device, according to claim 4, characterised in that the said plate (9) moves vertically between a raised position, inside the grouping frame, and a lowered position in which it defines the base of the grouping frame, the said lowering being stepwise in relation with the introduction of subsequent layers of articles (2) into the grouping frame (21). Device, according to claim 1, characterised in that the said gripping means (7) are constituted by pliers.

Inventors: MONTI GIUSEPPE, MONTI, GIUSEPPE
Applicants: MARCHESINI GROUP SPA, MARCHESINI GROUP S.P.A.
Application year: 1996
Main classification: B65B5
IPC codes: B65B5, B65B35