Device for feeding selected groups of products

Abstract: A selection device comprises a third conveyor (10) interposed between a first and a second conveyor (4, 7), and movable in accordance with a direction of advance (A) at a speed (V1) higher than the speed (Va) of the first conveyor (4); a vertical wall (11) interposed between the third conveyor (10) and the second conveyor (7), movable vertically in the two directions; accompanying means (12), set in proximity of the wall (11), and adjustable in height with respect to the third conveyor (10); means (13) for activating and deactivating the movement of the third conveyor (10) and accompanying means (12), acting on both, to be able to perform, in sequence: an arrest of the third conveyor (10) with the wall (11) lifted to set the front of the bottles (2) in proximity of the wall; a first activation of the third conveyor (10), with the stabilisation means (12) lifted from the bottles (2), such as to allow an advance of the front of the bottles (2) until contact with the wall (11) is attained to compact the bottles (2) and, lastly, a second activation of the third conveyor (10) with a lowering of the wall (11) and of the stabilisation means (12) on the bottles (2) to feed them towards the second conveyor (7) in predetermined groups (1) and with the simultaneous distancing of the group from the bottles (2) arriving from the first conveyor (4).

Description: The present invention relates to a machine for selecting groups of continuously fed products, particularly a machine for packaging groups of bottles by means of heat-shrinking plastic film, in accordance with the preambule of claim 1. Such a machine is known from EP-A-703167 of the same applicant. Within the field of the aforesaid automatic machine it is known that the production line (which is tasked with defining and selecting a group of bottles, then package it according to different criteria) comprises, in succession: a station for continuously feeding bottles (hereinafter we shall refer to this product, though it is applicable to other types of containers such as cans and the like) located upstream of the machine with respect to a line of advance of the bottles themselves. The latter advance on multiple rows of defined width and one behind the other on a horizontal conveyor belt towards an intermediate selection station able to define the format of the group of bottles to be wrapped (or their number), and comprising a second conveyor belt, also horizontal. Lastly a station for wrapping the group of bottles selected with a length of plastic film, preferably heat-shrinking. To obtain a proper separation into predefined groups of bottles, the aforesaid selection station is equipped (see patent application IT - BO93A000428 by the same Applicant) with a first wall, movable vertically in the two directions and located in correspondence with the final end of the feeding station to stop or let advance the bottles towards an intermediate pre-selection station, placed between the feeding station and the selection station. This intermediate station is equipped with a second vertical wall, placed at a distance from the first wall equal to a defined size of the group of bottles to be selected, and adjustable as a function of the aforesaid size. The second wall is also movable vertically in the two directions and in phase with the first one, in the sense that when the first wall is in a raised position interfering with the front of the selected group of bottles, the second wall is in an exclusion position and vice versa: in this way, when a certain number of bottles has moved beyond the first point of interference on the plane, a first subdivision of a group of bottles from the continuous waiting line is obtained, whereas the second point only tends to distance the various groups from one another when they are transported from the remanining branch of the intermediate station towards the selection station where the group is drawn by a transverse bar, guided by related chains, which comes in contact at the rear with the end row of the selected group immediately downstream of the final end of the pre-selection station. In a second solution (see also patent application IT - BO94A000160 by the same Applicant), the selection station is provided with a conveyor interposed between the feeding station and the selection station itself, which is movable in accordance with the direction of advance at a speed higher than the speed at which the feeding station is moved. The conveyor is moved intermittently thanks to a clutch assembly which allows the engagement and exclusion of the motion according to pre-determined stop and advance times, i.e. to feed the bottles to the selection station as a function of the groups to be formed with those bottles, and respectively a stop to the motion of the bottles, in co-operation with an upper plate able to block the advance of the front of the bottles. In the solutions mentioned above however, although problems related to the higher uniformity in the working speeds present in the various stations (which speeds are relatively high) were resolved, drawbacks have been noted due, in the first case, to the double stop to the bottles which does not allow a high productivity per time unit owing to mechanical limitations due to the alternate motion of the two blocking walls, in addition to the fact that such walls increase the risk that the bottles may fall as a result of the high speeds of motion involved in the various stations. Moreover, the second wall always requires an adjustment to its distance every time the format of the bottle groups is changed. In the second case described, the greater drawback is given by the possible lack of homogeneity in the advance of the bottles on the conveyor, or the various rows of bottles could be out of phase due both to the insufficient friction of the conveyor in the initial accelaration phase, and by a lack of bottle continuity on the rows of advancing bottles; all this may therefore lead to a stoppage in the line to allow to restore the correct feeding of the groups. The object of the present invention is therefore to eliminate the drawbacks mentioned above through the realisation of a machine for the selection of groups of products so structured as to allow a correct selection of the groups, with the certainty that the products always remain compacted during their advance, also maintaining a good productivity per unit of time with reduced costs. The technical characteristics of the invention, according to the aforesaid purposes, are defined in the appended claims and its advantages shall be made more evident in the description that follows, made with reference to the enclosed drawings, which show an embodiment provided purely by way of non limiting example, in which: Figures 1, 2 and 3 show a machine constituting the object of the present invention for packaging bottles ; the figures show a succession of respective operating configurations of the selection means in schematic side views with some parts removed the better to show others; Figure 4 shows an enlarged detail as per Figure 1 in which the elements comprising part of the subject selection means can be seen; the figure is shown in a schematic side view with some parts removed the better to show others; Figure 5 shows a partial view from C with respect to Figure 4 in which a part of the stabilisation and accompaniment means comprised in the subject machine can be seen. According to the figures of the attached drawings, the machine allows the selection of groups 1 of products, and in particular bottles 2, arranged in multiple rows both transversely, defining a front, and longitudinally defining a continuous line of the bottles themselves. The machine comprises, among other elements, a station 3 for continuous feeding of the bottles 2 according to a direction of advance indicated with the arrow A and according to a speed Va. This feeding station 3 comprises a first conveyor 4 extending horizontally and enclosing in a loop a first series of motor driven pulleys 5. In proximity with the downstream end of the feeding station 3, with respect to the aforesaid direction of advance A, is present a station 6 (shown only partially) for the advance of the bottles 2 in groups 1 with pre-determined length, with respect to the direction of advance A; this advancement station 6 comprises a second horizontal conveyor 7 enclosing in a loop a second series of motor driven pulleys 8. Between these two feeding and advancement stations 3 and 6 are fitted means 9 for selecting the bottles 2, whereby a move of the bottles themselves can be obtained from the feeding station 3 to the advancement station 6 in the aforesaid pre-settable groups 1. As can be seen in the attached figures, the aforesaid selection means 9 essentially comprise a third conveyor 10, a vertical wall 11, stabilisation and accompaniment means 12 and means 13 for selectively driving the third conveyor 10 and the stabilisation and accompaniment means 12. More in detail, the third conveyor 10 is coplanar, with its own active branch 10a, to the first and the second conveyor 4 and 7, interposed between them and movable in accordance with the aforesaid direction of advance A at speed V1 higher than the speed Va of the first conveyor 4 thanks to a related motor drive 25 connected to one of the pulleys 26 which move the third conveyor 10. This speed V1 is essentially equal to the speed V3 of the second conveyor 7. The vertical wall 11 is interposed between the third conveyor 10 and the second conveyor 7, and it is movable vertically in the two directions between a raised position blocking the front of the bottles 2 and respectively a lowered exclusion position, below the aforesaid active branch 10a, allowing passage to the bottles 2. To obtain these positions the vertical wall 11 is provided with motion means 24 comprising a hydraulic or pneumatic piston, fitted underneath the third conveyor 10. The stabilisation and accompaniment means 12 are fitted in proximity of the end of the third conveyor 10 closer to the second conveyor 7, and they can be adjusted in height with respect to the third conveyor 10 between a lowered position in contact with the free end of the bottles 2, and a raised position, released from the bottles themselves. As can also be observed in Figure 4, the stabilisation and accompaniment means comprise one or more belts 14 enclosing in a loop a pair of third pulleys 15 whereof at least one is connected to the aforesaid means 13 in such a way as to obtain a motion of the belts 14 at a speed V2 equal to the aforesaid speed V1 of the third conveyor 10. As can better be observed in Figure 5, these belts 14 are supported, for each side, by means of a rod, threaded and perpendicular to the third conveyor 10; on each rod 30 is screwed a nut 31 integral with a crosspiece 38 passing above the belts 14 and supporting a vertical piston 18p on each side of which are provided two guides 35 (whereof only one is visible, since the figure is only partial as the structure is essentially specular). The piston 18p and the guides 35 in turn support a plate 39, lying underneath them and parallel to the aforesaid crosspiece 38, connected at its ends to a respective swivelling bushing 40 supporting the first horizontal shaft 32 supporting the third pulleys 15 of the aforesaid belts 14 (the ones downstream with respect to the direction of advance A). The threaded rods 30 are in turn rotatingly supported by a bridge structure 33 fastened to the sides of the machine and they are motorised around their axis, by means of a kinematic mechanism comprising gears 41 and chain 42 and located above the bridge structure 33, in order to move in height the belts 14 (thanks to screwing the nuts 31 in one direction or the other) according to the height of the products to be fed. The minimum height position is shown as a dashed line in Figure 4. To obtain the aforesaid lowered and raised positions of the belts 14 with respect to the bottles 2, only the vertical piston 18p set above the belts 14 is used, together with the two guides 35 on each side thereof, and with which the belts 14 are raised and lowered away from and towards the bottles 2 (see arrows F in Figures 4 and 5); the lowering and raising stroke of the piston 18p lowers or raises plate 39 to which are integral, as stated above, the bushings 40 supporting the first shaft 32, thus allowing the belts 14 to come in contact with the bottles 2 or to move away from them. The belts 14 are also connected, at least on one of their sides, with a motion transferring assembly comprising a pair of arms 16 and 17 defining an articulated arm. On the pair of arms 16 and 17 are fastened at least three pairs of gears 19, 20 and 21 whereon are meshed a pair of chains 22 and 23 closed in a loop, in succession, on the gears themselves in order to transfer motion from the means 13, placed underneath the third conveyor 10, to the third pair of pulleys 15. The articulated arm structure allows to maintain constant the motion transfer regardless both of the movement in height of the belts 14 for adjustement with respect to the bottles 2, and of the contact motion of the belt 14 performed with piston 18p. The aforesaid means 13 for selectively driving the third conveyor 10 and the stabilisation and accompaniment means 12 comprise a known clutch assembly 27 connected to the aforesaid motor drive 25, or to the motor drive 25 alone, actuated or stopped automatically according to the machine cycle. To this motion assembly are connected at least the aforesaid pulley 26 of the third conveyor 10 and one of the chains 22 and 23 of the means 12 to impart the motion to the belts 14. The means 13 allow a succession of phases by the elements just described starting from a cycle start situation wherein bottles 2 are already present on the third conveyor 10. The first phase (shown in Figure 1) entails a stop of the third conveyor 10 in correspondence with the raised position of the wall 11 so as to position the front of the bottles 2 in proximity of the wall itself, but not in contact therewith. The second phase (shown in Figure 2) entails activating a first time the third conveyor 10, after raising the belts 14 from the upper end of the bottles 2; this motion of the third conveyor 10 allows an advance of the front of the bottles 2, according to direction A, sufficient to obtain contact of the front itself with the raised wall 11 and in such a way as to compact the bottles 2 positioned longitudinally on the third conveyor 10. The third phase (shown in Figure 3) entails activating a second time the third conveyor 10 simultaneously with a lowering of the wall 11 and of the belts 14 onto the bottles 2 in order to feed a number of bottles 2 towards the second conveyor 7 according to their predetermined groups 1, and obtaining a simultaneous distancing of the latter group from the subsequent said bottles 2 arriving from the first conveyor 4. Obviously, the first and second activation of the third conveyor 10 may be merged in a single activation if the descent speed of the wall 11 is sufficiently high to avoid a possible arrest phase of the third conveyor 10 to wait for the descent of the wall 11. Upon passage of the group 1 of bottles 2, there is another arrest of the third conveyor 10 to perform anew the sequence of phases just described. To obtain a higher stability of the bottles 2 selected, it is possible to insert a second belt 43 above the second conveyor 7 immediately downstream of the belts 14 (see in particular Figures 3 and 4). This second belt is closed on related pulleys 44 whereof one is directly driven by means of one of the pulleys 8 of the second conveyor 7: in this way the bottles 2 exiting the third conveyor 10 are held, for a certain length, both below and above at the same speed so as to keep them stable even after the acceleration imparted by the second activation of the third conveyor 10. This second belt 43 can be adjusted in height only when changing product format. The machine just described therefore attains its purposes thanks to a simple and economical structure, in addition to being able to be adapted to any kind of product thanks to the adjustment in height of the belts 14. The stop and re-start phase of the bottles, together with contact with the upper belts, makes the bottles remain stable during their feeding and selection; the phase entailing compacting the bottles against the vertical wall prevents an out-of-phase condition of the bottles by several rows arriving from the first conveyor, even if upstream of them there should be feeding gaps.

Claims: A machine for the selection of groups of products, the machine comprising at least one station (3) for the continuous feeding of said products according to a direction of advance (A) and at a speed (Va), said station (3) comprising a first conveyor (4) with horizontal extension enclosing in a loop a first series of motor-driven pulleys (5); in correspondence with the downstream end of said feeding station (3), with respect to said direction of advance (A), being provided a station (6) for advancing the products, in groups (1) whose longitudinal dimension, with respect to said direction of advance (A), are pre-determined and comprising a second horizontal conveyor (7) enclosing in a loop a second series of motor-driven pulleys (8); selection means (9) being provided between said feeding station (3) and said advancement station (6) and acting on said products (2) so as to define their transfer from said feeding station (3) to said advancement station (6) in said pre-determinable groups (1), said selection means (9) comprising: a third conveyor (10) coplanar, with its own active branch (10a), with said first and second conveyor (4, 7), interposed between them and movable in accordance with said direction of advance (A) at a speed (V1) exceeding that of said speed (Va) of said first conveyor (4); stabilisation and accompaniment means (12); means (13) for selectively driving the third conveyor (10) and said stabilisation and accompaniment means (12), acting on both; characterised in that said selection means (9) further comprise: a vertical wall (11) interposed between said third conveyor (10) and said second conveyor (7), movable vertically in the two directions between one raised position to block the front of said products (2) and respectively a lowered position of exclusion underneath said active branch (10a) and of Machine according to claim 1, characterised in that said stabilisation and accompaniment means (12) comprise at least one belt (14) enclosing in a loop a pair of third pulleys whereof at least one is connected to said means (13) for selectively driving the third conveyor (10) in such a way as to obtain the motion of said at least one belt at a speed (V2) equal to that of said speed (V1) of said third conveyor (10). Machine according to claim 2, characterised in that said at least one belt (14) is supported, at each side, by a structure provided with a threaded rod (30), set perpendicularly to said third conveyor (10), and whereto a crosspiece (38) is coupled by means of a nut (31) integral therewith, passing transversely above said at least one belt (14), and having at both ends a respective bushing (40) rotatingly supporting a first horizontal shaft (32) supporting said third pulleys (15) located downstream with respect to said direction of advance (A); said threaded rods (30) being in turn rotatingly supported by a bridge structure (33) fastened to the sides of the machine and said rods (30) being motor driven around their axis so as to allow a variation in height of said at least one belt (14) according to the height of said products (2) to be fed. Machine according to claim 3, characterised in that said crosspiece (38) supports a vertical piston (18p) on each side thereof are provided guides (35) supporting a plate (39), laying underneath them and parallel to the aforesaid crosspiece (38); at the ends of said plate (39) being integral respective said bushings (40) rotatingly supporting said first horizontal shaft (32) for imparting motion to said third pulleys (15); said piston (18p) acting on said plate (39) in such a way as to move said at least one belt (14) between a raised position for moving away from said products (2), and a lowered position of contact of said belt (14) with the upper end of said products (2). Machine according to claim 2, characterised in that said at least one belt (14) is provided with means for transferring motion comprising a pair of arms (16, 17) defining an articulated arm; on said arms (16, 17) being fastened at least three pairs of gears (19, 20, 21) whereto is meshed at least one pair of chains (22, 23) enclosing in a loop the same and able to allow the transfer of motion from said means (13) for selectively driving the third conveyor (10), located underneath said third conveyor (10), to said third pair of pulleys (15). Machine according to claim 1, characterised in that said vertical wall (11) is provided with means (24) for imparting motion comprising a fluid-driven piston located underneath said third conveyor (10), and able to allow said raised and respectively lowered position of the wall itself. Machine according to claim 1, characterised in that said second conveyor (7) is provided with a second accompanying belt (43) located above the second conveyor itself and immediately downstream of said stabilisation and accompaniment means (12); said second belt (43) being enclosing in a loop a pair of related pulleys (44) whereof one is connected to one of said second pulleys (8). Machine according to claim 1, characterised in that said second conveyor (7) presents a speed (V3) which is essentially equal to said speed (V1) of said third conveyor (10).

Inventors: BETTINI RODOLFO, BETTINI, RODOLFO
Applicants: AETNA GROUP SPA, AETNA GROUP S.P.A.
Application year: 1997
Main classification: B65G47
IPC codes: B65G47