METHOD AND APPARATUS FOR PRODUCING WRAPPINGS FOR SMOKING ARTICLES

Abstract

In a method of producing wrappings for smoking articles, the wrappings advance intermittently along a forming path with several stations, including a sealing station sealing the wrapping. Each wrapping continuously alternates a period of stop in a station with a period of movement between stations. A first predetermined stop time is associated with a first station, and a second predetermined stop time, greater than the first stop time, is associated with a second station, which is a sealing station. The second station has multiple positions for operating simultaneously on wrappings lots. Between stops in the first station, wrappings advance with a single step, with displacement that brings a wrapping to replace the immediately preceding wrapping. Between stops in the second station, wrappings advance with a multiple step, with a displacement that brings a wrappings lot to replace the immediately preceding lot in the positions of the second station.

Description

This application claims benefit of Italian Patent Application No. 102018000004903, filed 26 Apr. 2018 and which application is incorporated herein by reference. To the extent appropriate, a claim of priority is made to the above-disclosed application.

FIELD OF THE INVENTION

The present invention relates to the methods and apparatuses for producing wrappings for smoking articles or the like,—also including for example articles containing tobacco-based materials of the “heat-not-burn” type—in which the wrappings are advanced intermittently along a forming path which includes several stations, of which at least one station is a sealing station, suitable for performing a sealing operation on the wrapping, so that each wrapping continuously alternates a stop period in one station with a period of movement between one station and another.

BACKGROUND ART

According to the prior art, each individual wrapping is obtained by folding sheet material around a group of smoking articles, for example an ordered group of smoking articles and then, at least in some cases, by sealing the edges of the folded sheet material and containing the group of smoking articles, so as to form a partially or totally sealed wrapping. To this end, each wrapping being formed, consisting of the sheet material folded around a respective group of smoking articles, is advanced along a predetermined path, with intermittent motion, typically starting from a loading station, then through one or more sealing stations, to finally reach a station for unloading the finished or partially finished wrapping. Along the way, the wrappings are therefore subjected in an alternating manner to stop step, during which the different stations along the path operate on the wrappings located at them, and a movement step. In order to limit the accelerations of the conveyor devices, the time dedicated to the movement step is normally a considerable portion of the cycle time. It follows that the residual stop time is normally a portion of the cycle time equal to or less than half the total duration of the cycle. The duration of the stop, which is the shorter the more one tries to increase the speed of production of the machine, constitutes a limit particularly in cases in which sealing stations are provided along the path. In the sealing stations, the sealing is obtained with the use of heating elements which transfer heat to the sheet material forming the wrapping (typically a multilayer sheet which includes at least one layer of heat-sealable plastic material) up to the softening temperature of the sealable layer, at the same time providing for the compression of the edges of the sheet material in order to obtain the sealed connection thereof. The heat transfer is proportional to the temperature difference between the heating bodies and the sheet material and is proportional to the time available for such heating. Since the temperature of the heating bodies cannot exceed the damage temperature of the outer surface of the sheet material, it follows that the sealing time constitutes an inevitable limit to the increase in speed of the machines.

In some cases, this problem has been solved by providing for the execution of the pre-heating and sealing steps in several successive stations. However, this solution does not allow much improving the performance of the machine, since each heating is interspersed with a cooling, which occurs during the transfer of each wrapping from one station to another. Consequently, in these known solutions the total time necessary for the sealing operations does not correspond to the sum of the individual sealing times of the different sealing stations, and above a certain number of sealing stations, no advantageous effect is obtained in practice.

OBJECT OF THE INVENTION

The object of the present invention is to provide a method and an apparatus for producing wrappings for smoking articles, or smoke material in general, which allow drastically increasing productivity, making the stop time of the wrappings independent in each sealing station compared to the stop time of the wrappings in the other stations, so as to be able to reduce the cycle time to a minimum, simultaneously ensuring that the sealing operation is performed correctly and reliably.

A further object of the invention is to provide a method and an apparatus for producing smoking articles which allow achieving the above object with relatively simple and low-cost means.

SUMMARY OF THE INVENTION

In order to achieve one or more of the above objects, the invention relates to a method for producing wrappings for smoking articles or the like, wherein the wrappings are made to advance intermittently along a forming path which includes several stations, of which at least one station is a sealing station suitable for performing a sealing operation on the wrapping, in such a way that each wrapping continuously alternates a period of stop in a station with a period of movement between one station and the other, said method being characterized in that:

• • a first predetermined stop time is associated with at least a first station of said stations and a second predetermined stop time, greater than said first predetermined stop time, is associated with at least one second station of said stations, which is a sealing station,
  • said second station has multiple positions suitable for operating simultaneously on a lot of wrappings,
  • between one stop and the other in said first station, the wrappings are made to advance with a single step, that is, with a displacement that brings a wrapping to replace an immediately adjacent wrapping in the first station, and
  • between one stop and the other in said second station, the wrappings advance with a multiple step, that is, with a displacement that brings a whole lot of wrappings to replace an immediately adjacent lot of wrappings in the above multiple positions of the second station.

In a first embodiment, the method according to the invention is further characterized in that:

• • along the forming path, at least a first lot of wrappings is transported by a first conveyor device and at least a second lot of wrappings is transported by a second conveyor device, separated from the first conveyor device,
  • each conveyor device is controlled with different stop times and displacements depending on whether the lots of wrappings transported thereby are located at said first station or at said second station,
  • when a lot transported by the first conveyor device is located at said first station, in the second station there is a lot transported by the second conveyor device.

In the case of the above first embodiment, the above separate conveyor devices may for example be in the form of belt conveyors or wheel conveyors.

In a second embodiment, all the wrappings are transported along the forming path by the same belt conveyor device. In this case, the support structure of the entire belt conveyor device may be moved intermittently with respect to a stationary structure between two extreme operating positions, along a direction parallel to the longitudinal direction of the belt. In the case of this solution, the above first station is located along a first branch of said belt conveyor device while the above second station is located along a second branch of the belt conveyor device. The belt of the belt conveyor device moves intermittently with a single step, i.e. with a movement that brings each time to said first station a wrapping immediately following the wrapping which was located before in the first station. The movement of the support structure of the belt conveyor device takes place from a first end position to a second end position in an intermittent manner, with synchronous steps and of a length equal to length of each step of the belt with respect to the support structure of the belt, in such a way that while the various wrappings advance through the above first station in succession, the same lot of wrappings remains in the above second station.

In a third embodiment thereof, the method according to the invention is characterized in that said second station with multiple positions has a periodic operating step in which it is translated along said forming path so as to accompany a lot of said wrappings with equal speed of displacement in their movement along the forming path, whereby the stop of said lot of wrappings relative to said second station has a longer duration than the stop of each wrapping in the first station.

In a further embodiment thereof, the method according to the invention is characterized in that all the wrappings are transported along the forming path by the same conveyor device in the form of a linear electric motor with a stator defining a ring, or an elongated ring, on which a series of equipment move independently.

As is apparent from the foregoing, all the embodiments of the invention achieve the object of making the stop time in the second station (typically a sealing station) independent of the stop time in the first station (for example a loading station and/or an unloading station). In this way, the production apparatus can be set to operate with a minimum cycle time, without thereby introducing any risk for the quality and reliability of the sealing operation. The invention therefore allows obtaining an ideal compromise between the need on the one hand for high productivity and the need on the other hand for a high quality of the product.

According to a further aspect, the apparatus of the invention comprises a plurality of drawer supports each intended to receive and support a respective wrapping containing a respective group of smoking articles during transport along said forming path and through said stations,

• • each drawer support comprises at least one first wall and at least one second wall parallel to each other and spaced apart, so as to define a space therebetween for containing the respective group of smoking articles,
  • said first wall and said second wall have lateral edges for the lateral containment of the respective group of smoking articles within said containment space,
  • said walls are configured and arranged in such a way that the containment space defined therebetween is open on two opposite sides and on a third front side, so that said drawer support does not interfere with sealing operations carried out on the edges of the respective wrapping which protrude from said sides of the containment space.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Further features and advantages of the invention will become apparent from the following description made with reference to the accompanying drawings, given purely by way of non-limiting example, in which:

FIG. 1 schematically shows a first embodiment of an apparatus according to the invention,

FIGS. 1A-1F show different operating steps of the apparatus in FIG. 1,

FIG. 2 schematically shows a further solution, alternative to the embodiment in FIG. 1,

FIGS. 2A-2F show different operating steps of the apparatus in FIG. 2,

FIGS. 3A-3C schematically show different operating conditions of a second embodiment of the apparatus according to the invention, and

FIG. 4 schematically shows the different operating conditions of a third embodiment of the apparatus according to the invention,

FIGS. 5, 6 are a perspective view and a front view of a drawer support according to the present invention, and

FIG. 7 is a perspective view of a detail of the two belts provided in the embodiment in FIG. 1, in an example in which drawer supports of the type illustrated in FIGS. 5, 6 are used;

FIGS. 8, 9 and 10 are schematic perspective views of the wrapping in successive process steps;

FIG. 11 is a schematic perspective view of the wrapping obtained by the method.

In FIGS. 1 and 1A-1F, reference numeral 1 indicates as a whole an apparatus for producing wrappings for smoking articles or the like, including for example articles containing tobacco-based materials of the heat-not-burn type. By way of example, such wrappings may be designed to form packages in the form of a rigid box, with the wrapping of the smoking articles arranged inside the box. Or, again by way of example, the wrappings may themselves constitute the packaging, in the event that it does not include a rigid containment box.

Each wrapping consists of sheet material folded around a respective group of smoking articles. According to the prior art, this sheet material can be a multi-layer sheet, including at least one layer of heat-sealable plastic material (for example polyethylene) and one or more further layers, for example aluminium, paper, or plastic.

In the case of the solution illustrated herein by way of example, after the sheet material constituting each wrapping has been folded around a respective group of smoking articles, the edges of the sheet material are sealed together, along one or more sides of the wrapping, to obtain a partially or totally sealed wrapping.

All the solutions illustrated in the accompanying drawings refer to an example in which the partially formed wrappings, each consisting of sheet material folded around a respective group of smoking articles, are subjected to a sealing operation in one or more sealing stations. Again by way of example, in all the solutions described and illustrated herein, the wrappings are successively fed to a loading station 2, and are then advanced along a forming path 3 through at least one first sealing station 4, and then also through a second sealing station 5, to then reach an unloading station 6.

However, the invention is generally applicable to any case in which at least one first station is provided along the wrapping path, in which the wrapping must remain at least for a first predetermined stop time and a second station in which the wrappings must remain at least for a second predetermined stop time, greater than the aforementioned first predetermined stop time. The nature of the first station may be any and the nature of the second station may be any.

In the example shown in FIGS. 1 and 1A-1F, the system which advances the wrappings along the forming path 3 comprises two belt conveyor devices 30A, 30B arranged side by side in the direction orthogonal to the plane of such figures. For this reason, the drawings show the closed-loop belt of the device 30A which in some sections is shown interrupted, to show behind it the belt of the second device 30B (drawn blackened for greater clarity of illustration). The belts of the devices 30A, 30B are engaged respectively on wheels 7A, 8A and 7B, 8B. In the drawings, the wheels 7A, 8A are only partially illustrated, to show the wheels 7B, 8B behind them. One of the two wheels of each pair of wheels 7A, 8A and 7B, 8B is controlled by a respective electric motor (not shown). The two electric motors that control the two belt devices 30A, 30B are controlled independently of each other by an electronic controller according to one or more predetermined programs, as will be seen further hereinafter.

In the drawings, the belt devices 30A, 30B define elongated ring paths extended in the vertical direction. However, it is clear that the orientation of the belt devices can be any.

Again only by way of example, FIGS. 1 and 1A-1F show belt devices 30A, 30B in which supports 9 are associated with each belt for receiving and retaining respective wrappings 10 within them. In the drawings, the supports 9 are indicated respectively with 9A or 9B, depending on whether they are anchored to the belt of the belt device 30A or to the belt of the belt device 30B. Moreover, for greater clarity of illustration, the supports 9B are illustrated blackened, so as to distinguish them from the (white) supports 9A.

As is apparent, therefore, the movement of the supports 9A along the path 3 is operated by the belt conveyor device 30A, while the movement of the supports 9B along the forming path 3 is controlled by the second belt conveyor device 30B.

Moreover, in the illustrated example, all the supports 9 arranged along the forming path 3 are distributed in lots, alternately distributed along the closed-loop path. Again in the case of the illustrated example, each lot of supports 9 is formed by three supports 9.

FIGS. 1 and 1A-1F show, by way of example only, a rotor 11 which feeds in succession the partially formed wrappings (each consisting of a sheet material folded around a respective group of smoking articles) to the loading station 2, where each wrapping is picked up by a respective support 9A or 9B.

According to an important feature of this embodiment, each of the belt conveyor devices 30A, 30B is controlled differently along its advancement along the forming path, according to which the groups of supports 9A, 9B associated therewith are located at the loading and unloading stations 2, 6, or at the sealing stations 4, 5.

For example, in the situation illustrated in FIGS. 1A-1C, the supports 9A associated with the belt conveyor device 30A are adjacent to the loading and unloading stations 2, 3. In this step, the belt conveyor device 30A is controlled with intermittent movement and with a step preferably corresponding to the cycle time of the machine, i.e. with a single step, so that each movement between one stop and the other carries a single support 9A to replace the previous support in the loading station 2 or in the unloading station 6. Moreover, in this step the belt device 30A makes stops whose duration corresponds to the minimum time necessary to allow the loading of a wrapping in the station 2 and the unloading of a wrapping from the station 6.

As shown in FIGS. 1A-1C, the three supports 9A shown on the right in the figure move forward in the loading station 2, picking a respective wrapping 10, while the three supports 9A shown on the left in the drawing advance in sequence in the unloading station 6, where they release a finished or partially finished wrapping.

Each of the two belt conveyor devices 30A, 30B is displaced differently when the supports 9 associated therewith are located at the sealing stations 4, 5. Each of these stations has multiple positions (three positions in the example) in which, in a manner known per se, sealing bodies (not shown) are provided, which provide to seal juxtaposed edges of the sheet material wound around the group of smoking articles of each wrapping. For example, in the sealing station 4, the sealing may be performed along the two longitudinal sides of the wrapping, while in the sealing station 5 a third side of the wrapping is sealed, opposite to that corresponding to the bending line of the sheet material. Of course, however, this solution is illustrated herein purely by way of example, it being clear that any other choice is possible as regards the sides of the wrapping which are sealed in the stations 4, 5. When the supports 9A, 9B associated with a given belt conveyor device are located in the sealing stations 4, 5, the belt conveyor device is controlled with a stop time significantly greater than the stop time provided in the loading and unloading stations 2, 6, corresponding to the minimum time necessary to perform a sealing operation in a complete and reliable manner. Furthermore, the step of feeding a lot of wrappings to each of the sealing stations 4, 5 and the step of output of a lot of wrappings from each of such stations are controlled with a multi-step movement of the belt, i.e. with a displacement which brings a whole new lot of wrappings to replace the lot carried by the other belt that was before in the sealing station 4 and in the sealing station 5.

FIGS. 1D-1F illustrate operating steps in which the supports 9A associated with the belt conveyor device 30A remain in the sealing stations 4, 5, thus allowing the wrappings to remain in the sealing stations for a time adequate to complete the sealing operation in a correct and reliable manner.

As already indicated, the movement of the supports through the loading and unloading stations 2, 6 is an intermittent movement with a single step, while the movement of the supports entering and leaving the sealing stations 4, 5 is a movement in multiple steps, which allows a whole lot of wrappings to be alternated in each sealing station, with respect to the preceding lot.

During the execution of the sealing operations, the two belt devices 30A, 30B operate in counter-phase, meaning that when one of the belt devices maintains the respective supports 9A or 9B for a prolonged time in the sealing stations 4, 5, the other belt conveyor device intermittently advances its supports through the loading and unloading stations, with a single-step movement and with relatively short stops. Thus, for example, FIGS. 1A-1C show the steps in which the supports 9B are kept stationary in the sealing stations 4, 5 while the supports 9A advance intermittently through the loading and unloading stations 2, 6. FIGS. 1D-1F show that while the belt conveyor device 30A keeps its supports 9A still in the sealing stations 4, 5, the belt conveyor device 30B intermittently advances its supports 9B through the loading and unloading stations 2, 6.

When instead the sealing operation is completed and it is necessary to replace the lot of supports 9B (or 9A) which is in each sealing station with a new lot of supports 9A (or 9B), both belt devices 30A, 30B are controlled in synchronism with a multiple step. Thus, for example, in the transition from the step in FIG. 10 to the step in FIG. 1D, the two belt conveyors 30A, 30B move simultaneously to replace the lots of supports 9B with lots of supports 9A in the sealing stations 4, 5. Likewise, from the step illustrated in FIG. 1F, we return to the step illustrated in FIG. 1A through a simultaneous control with multiple steps of the two belt conveyor devices 30A, 30B, so as to replace the lots of supports 9A in the sealing stations 4, 5 with lots of supports 9B.

From the foregoing, the advantage obtained is clear. The stop time in the sealing station can be relatively long, so as to ensure the quality of the sealing operation, while the stop time in the loading and unloading stations can be reduced to a minimum. It follows that the total time to subject each wrapping to the complete cycle of operations can be drastically reduced with respect to the known solutions, which allows significantly increasing the productivity of the machine. At the same time, as is evident, this result is obtained with extremely simple and low-cost means.

FIGS. 2 and 2A-2F show a variant of the first embodiment illustrated in FIGS. 1 and 1A-1F. This variant operates substantially according to the same operating principle of the embodiment in FIGS. 1 and 1A-1F with the exception that the two conveyor devices 30A, 30B consist of two wheel conveyor devices, instead of two belt conveyor devices. The wheel conveyor device 30A includes three wheel spokes 300A, each of which carries three supports 9A, each of which can receive and hold a respective wrapping 10. The wheel conveyor device 30B comprises three spokes 300B arranged alternating with the spokes 300A. Each of the spokes 300B carries three supports 9B each of which is suitable for receiving and retaining a respective wrapping 10. The wrappings 10 to be formed are received at a loading station 2 and after forming are released into an unloading station 6. Similarly to the solution in FIGS. 1-6, two sealing stations 4, 5 are provided to carry out the sealing of different sides of each wrapping in succession.

The two wheel conveyor devices 30A, 30B are coaxially mounted on the same axis 12 and are controlled independently of each other by two electric motors (not shown). Similarly to the solution in FIGS. 1 and 1A-1F, the electric motors for driving the wheel conveyor devices 30A, 30B are controlled by one or more electronic controllers according to predetermined programs, in a similar way to what has been illustrated for the solution in FIGS. 1 and 1A-1F. Each wheel conveyor device 30A, 30B, therefore, in some operating steps is controlled by an intermittent single-step movement, to bring the supports 9 associated therewith in succession to the loading and unloading stations 2, 6. When one of the two wheel conveyor devices is in this condition, the other wheel conveyor device is stationary and keeps the wrappings associated therewith stationary in the sealing stations 4, 5. In the transition from one condition to another, both wheel conveyor devices are controlled simultaneously with a multi-step movement, so as to replace a whole lot of wrappings located in each of the two sealing stations with a new lot of wrappings. Thus, for example, FIGS. 2A-2C show the step in which the wheel conveyor device 30A is at a standstill and maintains two of the three lots of supports 9A associated therewith in the sealing stations 4, 5. At the same time, the wheel conveyor device 30B is controlled with an intermittent single-step movement, to bring supports 9B in succession at the loading station 2 and at the unloading station 6. FIGS. 2D-2F show an inverted condition, in which the wheel conveyor device 30A moves with an intermittent single-step movement, to bring the supports associated therewith in succession at the loading and unloading stations 2, 6, while the wheel conveyor device 30B remains stationary, in order to maintain two lots of wrappings 10 associated therewith stationary in the two sealing stations 4, 5. In the steps of transition from the condition in FIG. 2C to the condition in FIG. 2D, and from the condition in FIG. 2F back to the condition in FIG. 2A, the two wheel conveyor devices 30A, 30B are controlled simultaneously with a multi-step movement to replace the lot of wrappings located in each sealing station with a new lot of wrappings.

Of course, the above description with reference to the structure and operation of the embodiments illustrated in the accompanying drawings is provided purely by way of example. In particular, the laws of motion of the two conveyor devices may be any, different from those described herein and also different from each other.

FIGS. 3A, 3B and 3C of the accompanying drawings show three different operative steps of a second embodiment of the invention. In the case of this embodiment, a single belt conveyor device 30 is provided, including a belt 31 engaged on wheels 32, 33. Reference numeral 34 indicates the support structure (illustrated only schematically) of the belt conveyor device 30 on which the wheels 32, 33 are rotatably mounted. An electric motor is also associated with one of these wheels, which is also mounted on the support structure 34.

In the solution shown herein, the support structure 34 is in turn mounted movable with respect to a stationary structure 35 (also illustrated only schematically in the drawings) in the longitudinal direction X of the belt conveyor device, between two extreme positions, illustrated respectively in FIG. 3A and in FIG. 3C.

In FIGS. 3A-3B, reference numerals 2, 6 indicate the loading and unloading stations of the wrapping, provided along the upper branch of the belt, while reference numerals 4, 5 indicate the two sealing stations, provided along the lower branch. The supports 31 are associated with the supports 9 intended to receive and hold the wrappings at the loading station 2 and to release them at the unloading station 6. In the drawings, the direction of rotation of the belt is clockwise, so that in the upper branch the supports 9 advance through the loading and unloading stations 2, 6 moving from left to right, while in the lower branch the supports 9 move through the sealing stations 4, 5 moving from right to left.

In the steps illustrated in FIGS. 3A-3C, the belt is moved with an intermittent single step movement, so that each movement between one stop and the other carries a new support 9 to replace the immediately preceding support 9 in the loading station 2 and in the unloading station 6. Each belt stop between one movement and another has a duration corresponding to the minimum time necessary to perform the loading operation and the unloading operation. During each stop of the belt, the entire belt conveyor device 30 with its support structure 34 also remains stationary. Instead, during each movement of the belt 31, the structure 34 which supports the belt device 30 moves one step from its extreme left position to its extreme right position.

Thus, for example, FIG. 3B shows a step subsequent to that in FIG. 3A, in which the belt 31 has moved one step, so that a support 9x (illustrated blackened for clarity) which was in the loading station 2 has moved to a position immediately downstream of the loading station 2, while a support 9y (also blackened for clarity) which was in the unloading station 6 has been brought to the position immediately downstream of the unloading station 6 (with reference to the direction of movement of the belt 31). During the movement of the belt 31 between the stop illustrated in FIG. 3A and the stop illustrated in FIG. 3B, the entire belt device 30, with its support structure 34, moves with respect to the stationary structure 35 by one step to the right (with reference to the drawings). The length of each step performed by the support structure 34 is equal to the length of each step performed by the belt 31 with respect to the support structure 34. Therefore, along the lower branch of the belt, the displacement to the left (with reference to the drawing) of each support 9, due to the movement of the belt, is cancelled by the displacement towards the right of the support structure 34. This means that the two lots of supports 9z which in the condition in FIG. 3A were in the sealing stations 4 and 5, remain in these sealing stations even in the condition shown in FIG. 3B. FIG. 3C illustrates a subsequent step, in which the belt 31 has moved again by one step (whereby the supports 9x, 9y are each two positions further downstream with respect to the loading station 2 and to the unloading station 6), while the support structure 34 of the belt device 30 has moved another step in its horizontal movement, until it reaches the extreme right position, so that the two lots of supports 9z that previously were in the sealing stations 4, 5 continue to remain in such stations. Once the support structure 34 of the belt device 30 has reached the extreme position on the right illustrated in FIG. 3C, it quickly returns to its extreme left position, with a multi-step movement, which involves the replacement of the entire lot of supports 9z which is located in each of the sealing stations 4, 5 with a new lot of supports.

FIG. 4 schematically shows a third embodiment, in which any transport device (for example a belt conveyor device) provides to intermittently advance a succession of supports 9 along a longitudinal direction X. The set of supports 9 moves between one stop and the other with a single-step movement, that is, such as to involve the replacement of the support 9 which was previously in the loading station 2 and in the unloading station 6 with the subsequent support 9. Reference numerals 4, 5 always indicate the two sealing stations, which in this case consist of two structures movable in the direction x and carrying all the apparatuses necessary to carry out the sealing operations. During the advancement of the set of supports 9 along the direction X, the movable structures constituting the sealing stations 4, 5 move at the same speed in the direction X, so as to remain in a fixed position relative to the supports 9 which are located in each sealing station.

With reference to FIG. 4, letter A shows an initial situation, in which in the loading station 2 there is a support 9x (illustrated blackened for clarity) and in the unloading station 6 there is a support 9y (also illustrated blackened for clarity). During the stops of the supports 9x, 9y in the stations 2, 6, the structures constituting the sealing stations 4, 5 are also stationary and perform each the sealing operations on the wrappings carried by a respective lot of supports 9. During the subsequent movement of the conveyor line, the set of supports 9 moves one step, whereby the support 9x moves to the position immediately downstream of the loading station 2 and the support 9y moves to the position immediately downstream of the unloading station 6, while in the above loading and unloading stations the subsequent support 9 is introduced. During the movement of the conveyor line from the position in FIG. 4A to the position in FIG. 4B, the structures constituting the two sealing stations 4, 5 also move by one step, so that they continue to operate on the same wrappings which they were previously inside them. A similar operation occurs when from the position shown in FIG. 4B one transitions to the position illustrated in FIG. 4C. At the end of the stop in the position shown in FIG. 4C, the two structures constituting the sealing stations 4, 5 are rapidly moved with multiple steps in the direction opposite to the direction X so as to move to a starting position similar to that in FIG. 4A. At the same time, the conveyor line advances the set of supports 9 by a further step, so that in each sealing station 4, 5, the lot of supports 9 is replaced with a new lot. FIG. 4D illustrates again an intermediate situation, in which the succession of supports 9 must still complete its advancement in such a way as to completely replace the lot of supports 9 which was previously in each of the two sealing stations.

As is apparent from the above description, also the embodiments in FIGS. 3A-3C and 4 achieve all the advantages that have been outlined above.

Of course, any further conveyor system capable of achieving the objects that have been indicated herein may be used. For example, it may be provided that all the wrappings are transported along the forming path by the same conveyor device in the form of a linear electric motor, of the known type, with a stator defining a ring, or an elongated ring, on which a series of equipment move independently.

According to a further and independent aspect, the invention relates to an apparatus comprising a plurality of drawer supports C (FIGS. 5-7) each intended to receive and support a respective wrapping 10 containing a respective group of smoking articles S during transport along the forming path.

Each drawer support C can also be used in devices completely different from those described herein by way of example. C

With reference to FIGS. 5 and 6, each drawer support C comprises a first wall 101 and a second wall 102 mutually parallel and spaced, so as to define a space therebetween for containing the respective group of smoking articles S. In the illustrated example, the wall 101 is divided into two walls 101A, 101B separated by a slit 103 which extends over the entire length thereof. Again in the case of the specific example illustrated, the walls 101A, 101B and 102 project cantilevering from an end portion 104. The function of the slit 103 is to allow the insertion therethrough of an extractor knife which is pushed against the rear part of a wrapping 10 contained in the drawer support C when it is necessary to extract the wrapping from the drawer support C. As shown in particular in FIG. 6, the walls 101A, 101B and 102 have lateral sides (in the illustrated example defined by raised portions of the facing surfaces of said walls) for the lateral containment of the respective group of smoking articles within said containment space.

the walls 101A, 101B and 102 are configured and arranged in such a way that the containment space defined therebetween is open on two opposite sides and on a third front side, so that said drawer support does not interfere with sealing operations carried out on the edges of the respective wrapping which protrude from said sides of the containment space. FIG. 6 shows by way of example how the heating bodies W can engage with the edges of the wrapping projecting from the two opposite sides of the containment space to carry out the sealing of such edges. FIG. 7 shows the application of the drawer supports C in FIGS. 5, 6 to a device of the type shown in FIG. 1. The figure shows two drawer supports C mounted on two respective supports 9A, 9B which are in turn secured to the two belts 30A, 30B respectively.

The sheet material constituting each wrapping 10 is obtained by cutting starting from the tape being fed, in a cutting station. In the cutting station, transversal cuts are formed in succession in an advancing tape. The cuts define the tape portion 212 (FIG. 8) intended to constitute each wrapping 10. The sheets 212, separated from the tape, are advanced towards a station for folding each sheet 212 around a respective group 214 of smoking articles S (for example cigarettes). FIG. 8 schematically illustrates a single sheet 212 in the initial non-folded condition (shown in broken lines) and in the configuration folded on the two sides of a group 214 of cigarettes S.

Associated with the folding station is a device for feeding in succession groups 214 of cigarettes S to the folding station, where each sheet 212 is folded over a respective group 214 of cigarettes.

Again with reference to the illustrated example, once a sheet 212 has been folded so as to cover the major faces of the respective group 214 of cigarettes S, the assembly thus obtained is advanced through one or more sealing stations where the edges of the sheet 212 projecting along the two sides of the respective group 214 of cigarettes are juxtaposed to each other and sealed, so as to form two lateral flanges 212B (see FIG. 9). The fourth side of the wrapping thus formed is instead left open.

Of course, the tape is made of a plastic material which is also heat-sealable.

Means are provided for the purpose of folding the flanges 212B, after sealing, against the two sides of the wrapping 10 thus formed.

As already indicated, in this step of this embodiment of the method, one side of the wrapping consisting of the sheet 212 is still open and extends beyond the ends of the cigarettes S contained therein (see FIG. 9).

Again with reference to FIG. 8, the wrapping exiting from the station continues towards one or more heating stations.

The, or each, heating station includes a heating device, configured and controlled so as to obtain the heat-shrinking of the sheet 212 around the group of cigarettes contained therein. For example, hot air heating may be provided, or heating by one or more infrared lamps, or heating by hot metal plates. In any case, the examples of heaters provided herein should not be understood in a limiting sense. Each station may be for example in the form of a tunnel, through which the wrappings are made to advance by means of conveyor means, with continuous or intermittent movement, the tunnel containing one or more heating devices therein.

Therefore, the degree of heating of the wrappings in the heating station can be regulated both by adjusting the heating device, or the heating devices provided therein, and by adjusting the moving speed of the wrappings through the heating station and consequently the residence time of the wrapping in the heating station.

In the example of the embodiment in FIGS. 8-10, the heat-shrinking of the sheet material constituting the wrapping 212 is obtained when the wrapping still has an open side, which allows the air to escape from the wrapping during the heat-shrinking of the wrapping. At the exit from the heating station, the wrapping therefore has the appearance shown in FIG. 10, with the sheet material retracted against the cigarettes S contained in the wrapping, and one side of the wrapping still open.

In the case of the example illustrated in FIGS. 8-10, downstream of the station, the wrappings 10 thus formed are carried through one or more sealing stations where the sealing of the wrappings is completed, bringing the edges of the open side of the wrapping into juxtaposed position and forming a further sealed flange by heat sealing, so that the final wrapping, after sealing the last side of the wrapping, has the appearance that is shown in FIG. 11.

In a further embodiment, the sealing also of the last open side of the wrapping is carried out in the sealing station (or stations) upstream of the heating station or stations. Therefore, in this embodiment, the wrapping is heat-shrunk when it is already completely sealed, so that the air contained in the wrapping cannot escape from the wrapping during the wrapping retraction step. In this case the wrapping obtained has the “swollen” appearance shown in FIG. 11.

Once again, one of the essential features of the method consists in the fact of making the wrapping 10 with sheet material which at least partly comprises heat-shrinkable material and in the fact of providing, along the wrapping forming process, a heating step such as to bring the sheet material into a heat-shrunk condition, engaging around the smoking articles contained in the wrapping.

According to an embodiment, a method for forming a wrapping 10 around a group of smoking articles 214 or smoking material in general, comprising the step of folding a sheet material 212 around the group 214 of smoking articles S, or the step of arranging smoking material within the sheet material 212 after it has been folded.

Said method provides that said sheet material 212 comprises wholly or partially heat-shrinkable material and that said process comprises a step of heating the sheet material 212.

Said heating step is such as to bring the sheet material 212 into a heat-shrinking condition around the group 214 of smoking articles S or around the smoking material.

According to an embodiment; the method comprising the step of advancing a tape in the longitudinal direction of the tape through a cutting station, then through one or more stations for folding and loading the smoking articles S or the smoking material, and then through one or more sealing stations so as to produce in succession a series of wrappings 10, each having a group 214 of smoking articles S or smoking material therein. Downstream of said one or more stations for folding and loading the smoking articles or the smoking material, the wrappings 10 are made to advance through one or more heating stations to cause the heat-shrinking of the wrappings around the contents thereof.

As is apparent from the foregoing, the drawer support according to the invention solves the problem of maintaining the composition of the bundle consisting of the wrapping stable with the relative group of smoking articles during the transfer to the sealing station, as well as the problem of allowing access to the sealing bodies.

In theory, an improvement in the stability of the bundle could be obtained by inserting an internal cardboard, folded in a U shape, so as to make a tray, but the internal cardboard involves a complication, an increase in the cost of the wrapping and tends to absorb moisture from the product, thus altering the features that the sealed wrapping aims to maintain.

As indicated above, the drawer support is an independent aspect of the present invention and can be used in any transport system forming part of any type of apparatus for forming wrappings for smoking articles.

Of course, moreover, without prejudice to the principle of the invention, the details of construction and the embodiments may widely vary with respect to what has been described and illustrated purely by way of example, without departing from the scope of the present invention.

It should in particular be noted that the present invention applies not only to the forming of wrappings intended to come into direct contact with the smoking articles, but also to the forming of external wrappings, intended to wrap packages for smoking articles or the like.

Claims

1. Method for producing wrappings for smoking articles and the like, comprising advancing the wrappings intermittently along a forming path which includes a plurality of stations, of which at least one station is a sealing station for performing a sealing operation on the wrapping, so that each wrapping continuously alternates a period of stop in a station with a period of movement between one station and a next station, said method wherein:

a first predetermined stop time is associated with at least a first station of said stations and a second predetermined stop time, greater than said first predetermined stop time, is associated with at least one second station of said stations, which is a sealing station,

said second station has a plurality of positions for operating simultaneously on a lot of the wrappings,

between one stop and the other in said first station the wrappings advance with a single step, with a displacement that brings a wrapping to replace an immediately adjacent wrapping in the first station, and

between one stop and the next stop in said second station, the wrappings advance with a multiple step, with a displacement that brings a whole lot of the wrappings to replace an immediately adjacent lot of the wrappings in multiple positions of the second station.

2. Method according to claim 1, wherein:

along the forming path, at least a first lot of the wrappings is transported by a first conveyor device and at least a second lot of the wrappings is transported by a second conveyor device separated from the first conveyor device,

each conveyor device is controlled with different stop times and displacements depending on whether the lots of the wrappings transported by the conveyor device are located at said first station or at said second station,

when a lot transported by the first conveyor device is located at said first station, in the second station a lot is transported by the second conveyor device.

3. Method according to claim 2, wherein said separate conveyor devices are belt conveyors.

4. Method according to claim 2, wherein said separate conveyor devices are wheel conveyors.

5. Method according to claim 1, wherein all the wrappings are transported along the forming path by a same belt conveyor device, and wherein the support structure of the entire belt conveyor device is translatable intermittently with respect to a stationary structure between two extreme operating positions, along a direction parallel to a longitudinal direction of the belt conveyor device, and wherein:

the first station is located along a first branch of said belt conveyor device, and the second station is located along a second branch of the belt conveyor device.

the belt of the belt conveyor device moves intermittently with a single step, with a movement that brings to the first station a wrapping immediately following the wrapping which was located before in the first station;

movement of the support structure of the belt conveyor device takes place from a first end position to a second end position in an intermittent manner, with steps synchronous to the steps of the belt and of a length equal to length of each step of the belt with respect to the support structure of the belt conveyor device, so that while a plurality of wrappings advance through the first station, the same lot of wrappings remains in the second station,

the movement of the support structure of the belt conveyor device from the second end position to the first end position takes place with a single movement having a length as to cause a replacement of the entire lot of wrappings that was before in the second station with a new lot of wrappings.

6. Method according to claim 1, wherein said second station with multiple positions has a periodic operating step in which it is translated along said forming path so as to accompany a lot of said wrappings with equal speed of displacement in their movement along the forming path, whereby the stop of said lot of wrappings relative to said second station has a longer duration than the stop of each wrapping in the first station.

7. Apparatus for producing wrappings for smoking articles and the like, comprising a conveyor device for intermittently advancing the wrappings along a forming path which includes a plurality of stations, of which at least one station is a sealing station, for performing a sealing operation on the wrapping, in such a way that each wrapping continuously alternates a period of stop in a station with a period of movement between one station and the other, said apparatus wherein:

said conveyor device is configured and controlled in such a way that a first predetermined stop time is associated with at least a first station of said stations and a second predetermined stop time, greater than said first predetermined stop time, is associated with at least one second station of said stations, which is a sealing station,

said second station has multiple positions for operating simultaneously on a lot of wrappings,

between one stop and the other in said first station the conveyor device is configured and controlled to advance the wrappings with a single step, that is, with a displacement that brings a wrapping to replace the immediately adjacent wrapping in the first station, and

between one stop and the other in said second station, the conveyor device is configured and controlled to advance the wrappings with a multiple step, that is, with a displacement that brings a whole lot of wrappings to replace an immediately adjacent lot in the multiple positions of the second station.

8. Apparatus according to claim 7, wherein:

the conveyor system comprises a first conveyor device for transporting at least a first lot of wrappings along the forming path, and a second conveyor device, separated from the first conveyor device, for transporting at least one second lot of wrappings along the forming path,

each of the two conveyor devices is associated with a control device programmed for controlling the respective conveyor device with different stop times and displacements depending on whether the lots of wrappings transported are located at said first station or at said second station,

the two conveyor devices are configured so that when a lot of wrappings transported by the first conveyor device is located at said first station, in the second station a lot of wrappings is transported by the second conveyor device.

9. Apparatus according to claim 8, wherein said separate conveyor devices are belt conveyors.

10. Apparatus according to claim 8, wherein said separate conveyor devices are wheel conveyors.

11. Apparatus according to claim 7, wherein all the wrappings are transported along the forming path by a same belt conveyor device, and wherein the support structure of the entire belt conveyor device is translatable intermittently with respect to a stationary structure between two extreme operating positions, along a direction parallel to the longitudinal direction of the belt conveyor device.

12. Apparatus according to claim 7, wherein said second station with multiple positions is translatable along the forming path to accompany a lot of said wrappings with equal speed of displacement in movement along the forming path, whereby the stop of said lot of wrappings relative to said second station has a longer duration than the stop of each wrapping in the first station.

13. Apparatus according to claim 7, wherein all the wrappings are transported along the forming path by the same conveyor device comprising a linear electric motor, with a stator defining a ring, or an elongated ring, on which a series of equipment move independently.

14. Apparatus according to claim 7, wherein:

the apparatus comprises a plurality of drawer supports each of the supports receiving and support a respective wrapping containing a respective group of smoking articles during transport along said forming path and through said stations,

each drawer support comprises at least one first wall and at least one second wall parallel to each other and spaced apart, to define a space therebetween for containing the respective group of smoking articles,

said first wall and said second wall have side portions in relief for the lateral containment of the respective group of smoking articles within said containment space,

said walls are configured and arranged so that the containment space defined therebetween is open on two opposite sides and on a third front side, so that said drawer support does not interfere with sealing operations carried out on edges of the respective wrapping which protrude from said sides of the containment space.

15. Apparatus according to claim 14, wherein said first wall is divided into two wall portions separated by a slit which extends over an entire length of the wall.