EP2390190A1

EP2390190A1 - Machine for packaging products of various kinds into bags of heat weldable plastic material.

Info

Publication number: EP2390190A1
Application number: EP11167309A
Authority: EP
Inventors: Andrea Salamon
Original assignee: Msa Service di Salamon Andrea
Current assignee: Msa Service di Salamon Andrea
Priority date: 2010-05-26
Filing date: 2011-05-24
Publication date: 2011-11-30
Also published as: ITPN20100029A1; IT1400298B1

Abstract

Automatic machine for packaging products of various kind into bags of heat weldable plastic material, in which the bags are obtained from a continuous band formed by two thin sheets overlapped and joined to each other along their side edges, or formed by a single sheet.

Machine comprising a first and a second movable roll (15, 23), which can be moved away and approached to each other, and provided with cutting means (29) and sealing means (31, 44) of the continuous band (6), and also comprising a first and a second pliers carrying support (32, 37) provided with a relative grasping pliers (34, 39) of the continuous band (6), which can be moved away and approached to each other, and detaching means (42, 43) of the bag which has been formed and filled with the desired products.

During the operation, the continuous band (6) is unwound from a feeding roll (9) and advanced through the movable rolls (15, 23), the pliers (34, 39), the cutting means (29) and the sealing means (31, 44'), so as to form a bag which is then welded, filled with the products and detached from the machine.

Description

The invention relates to an automatic machine for packaging products of various kind into bags of heat weldable plastic material, which is transparent or not transparent, in which the bags obtained by a continuous band of such material are at first opened and in succession filled with the products and sealed for the delivery.
Automatic machines for packaging products of various kind into bags of heat weldable plastic material are known, which bags are obtained by a continuous band of such material formed by two thin sheets overlapped and joined to each other along the side edges thereof.
This continuous band is introduced into the machine and wound around a feeding roll providing for advancing intermittently the band towards a cutting and sealing station, where the band is firstly stopped and then cut at the desired length and finally sealed at one end portion thereof so as to form a bag. Afterwards, the two sheets of the bag are spread apart from each other at the other free end portion thereof, on a station constituted by rollers of adhesive material which are firstly pushed against the relative band sheets, in a manner to adhere closely and temporarily to the same sheets on the bag free end portion, and then these rollers are moved away from each other thereby spreading apart the sheets and allowing to introduce in the interior of the bag the products which have been introduced on a machine loader, which is associated to this operative station. When the filling of the bag is ended, the loading of the products is stopped and the rollers are detached from the bag free end portion, thereby closing the bag, and arrange themselves for a subsequent operation, while this bag free end portion is sealed on to said sealing station, with consequent closing of the bag with the products contained therein, for being delivered.
However, the so realized machines aren't sometimes able to operate during the time in a satisfactory manner, in that the rollers of adhesive material doesn't adhere always effectively against the bag free end portion, and therefore may determine incomplete openings or even failures to open the sheets of the continuous band, with consequent impossibility to fill all the bags with the requested products, and need to stop the machine for repairing or replacing these rollers.
The object of the present invention is to made an automatic machine of the kind referred to, with such characteristics as to eliminate the drawback of the machines currently existing on the market, and to ensure always a filling of all the bags with the required products, thereby ensuring an effective and fully reliable operation of the same machine.
This automatic machine is made with the constructive characteristics substantially described, with particular reference to the enclosed patent claims.
The invention will be understood better by the following description, given by way of not limitative example only and with reference to the accompanying drawings in which :

Fig. 1 shows a schematic cutaway side view of the bag packaging machine according to the invention ;
Figs. 2-12 show, with the same view of Fig. 1, the packaging machine displaced into different operative steps thereof;
Figs. 13 and 14 show a schematic cutaway front view of a component part of the machine according to the invention, displaced into two different operative positions thereof.

The above mentioned Figures illustrate schematically the automatic machine 5 for packaging products of various kind into bags of heat weldable plastic material, which is transparent or not transparent, in which the bags are obtained by a continuous band 6 of such material, formed by at least two thin sheets overlapped and joined to each other along the side edges thereof, or by a single sheet folded in a manner to form at least two sheets overlapped to each other.
The machine is substantially constituted (see Fig. 1) by a metallic rigid load carrier framework 7, provided with a lower lengthened base 8 adequately secured to the floor and on the upper and back portion of which an idle feeding roll 9 is supported, onto which the continuous band 6 of plastic material is wound, which roll rotates and unwind progressively such band with a slow and intermittent movement, and the advancing of such band occurs in the single advancing direction A towards the different machine component parts which will be described in detail, in order to form the bags and to fill them with the desired products.
Moreover, such feeding roll 9 is associated with different rolls 11, 12, 13 and 14 supported by the load carrier framework 7, on to which the continuous band 6 is wound and kept tensioned as well as driven and guided along its advancing path, wherein such band is firstly advanced from an upper to a lower position and thereafter in a reverse direction, and finally through powered and tensioning rolls 13 and 14, adapted to drive and keep tensioned the same band, such band is passed through the operative station which will be described, where the band is firstly cut and opened at an end portion thereof, and then is filled with the desired products, which have been introduced in advance into a suitable container-loader (not shown) supported on the machine upper part, thereafter it is sealed by means of welding of its leading and tail end portions, and finally it is detached from this operative station and made available ready for delivery.
This operative station is substantially constituted by at least a first movable roll 15 (see also Figs. 13 and 14), pivoted in a crank mechanism 17 supported on and fixed laterally the machine load carrier framework 7 and constituted by a lengthened bar 18 having a central lengthened through slot 19, in which a bearing 20 is housed and slidable with a limited stroke, which bearing is secured to the end portion of the movable roll 15, and which bar is also provided with two identical cranks 21 pivoted at the one end portion thereof in the load carrier framework 7 and at the other end portion thereof to a relative end portion of the lengthened bar 18, said bar being in turn actuated with a rectilinear alternate movement in the longitudinal direction by a pneumatic or hydraulic cylinder 22 or the like, fixed to and supported by the load carrier framework 7.
Besides, such first movable roll 15 is mounted in the machine in a stationary position, situated below the position of said powered and tensioning rolls 13 and 14 and coinciding with the position of these latter. The operative station is also constituted by at least a second movable roll 23 (see Figs. 13 and 14 again) identical to the previous roll and fixed to and supported by a carriage 24 driven by a relative pneumatic, or hydraulic cylinder or the like (not shown), which is fixed to and supported by the load carrier framework 7, said carriage being slidable together with the second roll 23 with a short stroke along longitudinal guide members 25 of the load carrier framework 7.
Such second roll 23 is fixed at an end portion thereof to a bearing 26, also housed and slidable with a limited stroke in the central through slot 19 of the bar 18, near the previous bearing 20, in a manner that the rolls 15 and 23 are aligned with each other and displaced by the movement of the carriage 24 in the longitudinal direction, from a position approached to each other (see Figs. 3-7, and 9-11), to a position moved away from each other (see Figs. 2, 8 and 12), in which between these two rolls a free space is defined for the passage of the continuous band 6, and vice versa. Furthermore, these movable rolls 15 and 23 are driven by the crank mechanism 17 from a lowered position (see Fig. 14) during the sucking and cutting steps of the continuous band, to a lifted position (see Fig. 13) during the welding step of the end portions of each bag filled with the desired products. Finally, the movable rolls 15 and 23 are provided with relative inner cavities 27 and 28 communicating by means of suitable conduits with a vacuum source constituted by at least a vacuum pump (not shown) installed in the machine, which is driven for established time periods during each machine operative cycle in which the movable rolls are pushed into contact with the two opposite sides of the continuous band 6, in order to provide for a suction action with such an intensity as to let the same rolls to adhere closely to such sides of the band, so as to perform the function which will be described later on. The one of the movable rolls, in the example the roll 15, is also provided with at least a rectilinear cutting blade 29, situated in such a position as to be able to act against the continuous band 6, and driven by a pneumatic or hydraulic cylinder 30, or the like, from a re-entered position in which it does not act against the continuous band 6, to a position projected beyond the supporting roll, in which it acts against the continuous band 6, by cutting it, and vice versa. Finally, such movable rolls are also provided with relative welding means 31 of traditional type, situated on the same rolls in a position different than that of the cutting blade 29 and such as to be able to act against the two sides of the continuous band 6, so as to weld to each other the two end portions of each bag which is formed after that a band portion has been cut, and filled with the desired products, in the manner which will be described later on.
In particular, these welding means 31 are situated in the relative movable rolls in a position spaced away from that of the cutting blade 29, in a way that they may act against the two sides of the continuous band 6 separately from the action of the cutting blade 29, and only after that this latter has cut a band portion and then has been moved away therefrom. In the indicated example, these welding means 31 are situated in the lower zone of the movable roll 15, and are activated after that these rolls have been moved away in the raised position and pushed contemporaneously against the two sides of the portion of the continuous band.
The packaging machine according to the invention also comprises a first fixed pliers carrying support 32, pivoted on the load carrier framework 7 in a position corresponding to that of the first movable roll 15 and shaped with a flat upper surface 33 in which a short flat pliers 34 is applied in the machine transversal direction, which is provided with a terminal edge 35 inclined downward and situated above the relative movable roll 15. Such first pliers carrying support 32 is actuated by a pneumatic or hydraulic cylinder 36, or the like, with a short stroke in the rotating direction, from a raised to a lowered position, and vice versa, for the reason which will be described.
Besides, the machine comprises a second movable pliers carrying support 37, pivoted on the carriage 24 in a position corresponding to that of the second movable roll 23 and shaped with a flat upper surface 38, to which a short flat pliers 39 is applied in the machine transversal direction, which pliers is provided with a terminal edge 40 inclined downward and situated above the relative movable roll 23 and on a position aligned with that of the preceding pliers 34. Also this pliers carrying support 37 is actuated by a pneumatic or hydraulic cylinder 41, or the like, with a short stroke in the rotating direction, from a raised to a lowered position, and vice versa, for the reason which will be described. Furthermore, the machine comprises at least a loader (not shown) arranged on a position above that of said movable rolls 15 and 23, which is filled in advance with the desired products to be introduced into the bags, which is associated to traditional control means (not shown) for providing the selective filling of each bag with the desired quantities of these products.
Finally, the present machine comprises a detaching system of each filled bag, which is formed by a pneumatic or a hydraulic cylinder 42, or the like, fixed to the carriage 24 in a position below the movable roll 23, and by an opposite sprung stud 43 supported in a position below the movable roll 15, such cylinder and stud being situated at the two sides of each bag and being able to act against the same sides, so as to determine and make easier as it will be described the detaching of each bag from the machine. Now, there are described the various operative steps of each working cycle of the automatic machine according to the invention, in the first of which (see Fig. 2) the carriage 24 and the movable roll 23 as well as the pliers carrying support 37 are displaced in a position moved away from the movable roll 15 and the pliers carrying support 32, thereby defining between such component parts the free space for the passage of the continuous band 6. Under this condition, moreover, the movable rolls 15 and 23 are displaced in the lowered position thereof and aren't fed by the vacuum of the vacuum pump, and the cutting blade 29 is re-entered into the movable roll 15. The powered and tensioning rolls 13 and 14 are driven slowly in rotation, so that also the continuous band 6 is unwound progressively from the roll 9 and advanced by the various rolls in the direction A, entering vertically said free space for a determinate length, thereby defining a band portion which forms a bag, and at this point the advancing of the continuous band 6 is stopped. Under this condition, the lower end portions of the sheets of the band portion are closed in that they have been welded to each other during the previous welding step, which will be described later on. In the subsequent operative step (see Fig. 3), the carriage 24 is displaced automatically leftwards together with the pliers carrying support 37 and the movable roll 23, up to arrange close to each other the movable rolls 15 and 23 and the pliers carrying supports 32 and 37, and under this condition the portion of the continuous band is tighten at its sides by the movable rolls 15 and 23, which are so positioned in correspondence of the area in which the band portion will be then cut for forming the bag. Afterward, the vacuum feeding of the movable rolls 15 and 23 is started, with consequent sucking by these latter of the sheets of the band portion and adhering of the same sheets against the movable rolls. In the subsequent operative step (see Fig. 4), by keeping the movable rolls 15 and 23 still pushed against the two sides of the portion of continuous band, it is at first effected a slight rotation of the powered and tensioning rolls 13 and 14 in a direction opposite to the advancing direction A, thereby providing a traction of the band 6, and then the cutting blade 29 is actuated, which therefore cuts the portion of continuous band.
Thereafter, in the subsequent operative step (see Fig. 5) the cutting blade 29 is returned back in the re-entered position thereof and the carriage 24 with the roll 23 and the pliers carrying support 37 is moved backward, by detaching it slightly from the roll 15 and the pliers carrying support 32.
In the subsequent operative position (see Fig. 6) the movable rolls 15 and 23 are displaced contemporaneously in the raised position thereof, and arrange themselves for welding the end portions of each bag, and the raising of these movable rolls provides for spreading apart the upper edges of the portion of continuous band, thanks to the sucking action produced by the vacuum which keeps the movable rolls always adherent to the sheets of such band portion.
In the subsequent operative step (see Fig. 7) the pliers carrying supports 32 and 37 are actuated contemporaneously, with consequent limited rotation downward thereof and penetration of the inclined edges 40 and 35 of the pliers 39 and 34 between the upper edges of said portion of continuous band, which therefore are locked into position.
In the subsequent step (see Fig. 8), still keeping the movable rolls 15 and 23 in the same preceding positions, it is actuated the carriage 24 in the opposite direction along the guide members 25, for a pre-established distance such that to detach from each other the two sheets of the portion of continuous band, and then in the space so defined between these sheets there are introduced the desired quantities of the desired products 44.
In the subsequent step (see Fig. 9) the carriage 24 is displaced again into the same position of Fig. 7, so that the edges of the band portion are approached to each other again, and then welded by means of the welding means 31, thereby obtaining the bag with the products contained therein. Furthermore, during this step additional welding means 44' provided in the machine above the welding means 31 provide to weld and to close also the lower end portion of the subsequent band portion, thereby forming the closed bottom of the subsequent bag.
In the subsequent operative step (see Fig. 10) the movable rolls 15 and 23 are always kept into the same position and the vacuum feeding thereof is terminated, while the pliers carrying supports 32 and 37 are still raised slightly and contemporaneously, so that the inclined edges 40 and 35 of the pliers 39 and 34 disengage themselves from the welded edges of the so obtained bag.
In the subsequent operative step (see Fig 11), compressed air is introduced into the movable rolls 15 and 23, which air is therefore directed toward the welded bag end portion, and such rolls are gradually displaced into the lowered position thereof, while the detaching cylinder 42 is pushed at time intervals against a side of the bag, the other side of which is so pushed against the sprung stud 43, and owing to this pushing action combined with the blowing of compressed air it is determined the detaching of the bag from this position. Finally, in the remaining operative step (see Fig. 12) the movable rolls 15 and 23, displaced in the lowered position, are moved away from each other, by displacing the carriage 24 along the guide members 25 in the opposite direction, together with the movable pliers carrying support 37 which therefore is moved away from the fixed pliers carrying support 32. Consequently, the bag falls and is collected into an underlying container (not shown), and the movable rolls are displaced in the lowered position, while the continuous band 6 is advanced again through the free space, so as to arrange the machine for performing a subsequent cycle. In this way, the present automatic machine allows to obtain always the opening of each bag, thanks to the sucking action produced by the vacuum which determines an effective and safe adhering of the movable rolls against the end portions of the sheets of the continuous band 6.

Claims

Automatic machine for packaging products of various kind into bags of heat weldable plastic material, which is transparent or not transparent, the bags being obtained by a continuous band of such material formed by two thin sheets overlapped and joined to each other along the side edges thereof, or formed by a single sheet, which band is wound around a feeding roll supported on the machine load carrier framework and advanced in an intermittent manner by motor means, tensioning means and guiding means toward cutting and sealing means, where the band is firstly stopped and then cut at the desired length and finally sealed at one end portion thereof so as to form a bag, which is opened and filled with the desired products contained into a loader and finally is closed, sealed and detached and collected for being delivered, characterized by first and second movable means (15, 23) associated with said motor and tensioning means (13, 14) and communicating with vacuum generating means for providing for an intermittent suction , as well as provided with cutting means (29) and sealing means (31, 44'), and characterized by first and second grasping means (32, 34 ; 37, 39) and detaching means (42, 43) acting on to the band of each bag, said first movable means (15) being mounted in the load carrier framework (7) on a fixed position, which is situated below and coincident with the position of said motor and tensioning means (13, 14), and said second movable means (23) being mounted into at least a carriage (24) movable in the machine from a position spaced away to a position approached with respect to said first movable means (15), and vice versa, said first and second movable means (15, 23) being able to be driven at the same time, on their approached position, into a first position to provide for the suction of the same of the two sheets of the continuous band (6), and the consequent opening and cutting of the so formed bag, and into a second position to provide for the sealing of the bag with the products introduced therein, and characterized in that said first and second grasping means (32, 34 ; 37, 39) are mounted articulated respectively near said first and second movable means (15, 23), and may be displaced from a position moved away with respect to the continuous band (6), when said carriage (24) is moved away from said first movable means (15), so as to allow the passage of the continuous band (6) for forming and filling the bag, to a position approached with respect to the bag in order to grasp, guide, seal and detach the same, and characterized finally in that said detaching means (42, 43) are adapted to act against the bag after the same has been sealed, with a pushing action combined with a push produced by compressed air directed against the bag, in a way to provide for the detaching and falling of the same bag from the machine.
Machine according to claim 1, characterized in that said first and second movable means comprise respectively a first and a second movable roll (15, 23) pivoted on a crank mechanism (17) supported by and secured laterally the load carrier framework (7) and constituted by a lengthened bar (18) provided with a lengthened central through slot (19), in which a first and a second bearing (20, 26) are slidably housed, which bearings are secured to the corresponding first and second movable roll (15, 23), said bar (18) being provided at its end portions with two cranks (21) pivoted on the load carrier framework (7) and driven by control means (pneumatic, hydraulic cylinder 22 or the like) with an alternative rectilinear movement in the longitudinal direction.
Machine according to claim 2, characterized in that said first and second movable roll (15, 23) are provided with relative inner cavities (27, 28) communicating with said vacuum generating means, in order to provide for a suction action when said first and second movable roll (15, 23) are approached to each other, and into contact with the two sides of the continuous band (6), and are displaced in the said first or second position thereof, and are also provided with said sealing means (31, 44) which are activated when said first and second movable roll (15, 23) are displaced into said second position, in a manner to seal contemporaneously the head of a bag and the bottom of the subsequent bag.
Machine according to claim 3, characterized in that said first movable roll (15) is also provided with said cutting means (cutting blade 29), situated on a position spaced away from that of said sealing means (31) and acting against the two sides of the continuous band (6) before the action of the same sealing means.
Machine according to claim 4, characterized in that said first and second grasping means comprise respectively a first fixed pliers carrying support (32), pivoted in the load carrier framework (7) on a position corresponding to that of said first movable roll (15), and a second movable pliers carrying support (37) pivoted in said carriage (24) on a position corresponding to that of said second movable roll (23), said first and second pliers carrying support (32, 37) being shaped respectively with an upper flat surface (33, 38) in which at least a corresponding short flat pliers (34, 39) is applied in the machine transversal direction, which pliers is provided with a relative terminal edge (35, 40) inclined downward and situated above the corresponding movable roll (15, 23), wherein said pliers (34, 39) are disposed aligned to each other, said first and second pliers carrying support (32, 37) being actuated by control means (pneumatic, hydraulic cylinder 36, 41 or the like) in the rotating direction, from said first to said second position, and vice versa.
Machine according to claim 4, characterized in that said detaching means comprise at least a pushing cylinder (42) secured into said carriage (24) on a position below said second movable roll (23), and at least a sprung stud (43) supported on a position below said first movable roll (15) and opposite to said pushing cylinder (42), said pushing cylinder and stud (42, 43) being situated at the two sides of each bag and adapted to act against the same sides after the bag has been sealed, in order to provide for and make easier the detaching of the same bag.