Patent Description:
The present invention relates to a packer machine for the production of pouches containing portions of a loose product. The present invention finds advantageous application to the production of snus pouches (namely, permeable pouches each containing a prepacked portion of a loose and moist nicotine-based product for oral use), to which the following disclosure will make explicit reference without thereby loosing generality.

As known, snus pouches have a rectangular shape and have a longitudinal seal and a pair of transverse seals.

A known packer machine (for example as described in patent application <CIT>) for the production of snus pouches comprises: a conveyor device for conveying a band of wrapping material along a packing path; a wrapping station arranged along the packing path and where the band of wrapping material is wrapped so as to form a tubular wrap having a longitudinal development; a longitudinal sealing unit to longitudinally seal the tubular wrap in the area of an overlapping section of the band of wrapping material; a feeding device for the loose material to feed, one after the other, the portions of loose product into the tubular wrap; a transverse sealing unit to transversally seal the tubular wrap so as to form an alternating succession of sealing sections and sections containing a portion of loose product; and a cutting unit to transversely cut the tubular wrap in the area of the sealing sections in order to separate the single snus pouches.

In particular, the feeding device ends with a feeding duct (having a circular cross-section) around which the wrapping material is bent so as to form the tubular wrap and which feeds the portions of loose product into the tubular wrap.

The longitudinal sealing unit comprises a heated sealing head (for example a rotating roller) which is movably mounted to be pushed with a calibrated elastic force against a striker element (generally made with a material having a low friction coefficient), which is mounted on the feeding duct and has a flat surface facing the sealing head. In other words, to carry out the longitudinal sealing, the sealing head, and the striker element "pinch," together the overlapping portions of the tubular wrap to simultaneously apply both heat (generated by the sealing head) and mechanical compression.

In the case of a double-line packer machine, all the operating components are "doubled" to simultaneously create two twin and side by side tubular wraps; in this embodiment, the longitudinal sealing unit comprises two heated sealing heads which are arranged next to one another and are mounted on the same movable element which is pushed with a calibrated elastic force generated by a single common actuator device.

The compressed air which is used to feed the portions of loose product into the tubular wrap is vented (namely, it is let out from inside the tubular wrap) between the longitudinal sealing unit and the transverse sealing unit so as to prevent the tubular wrap from inflating like a "balloon. " The compressed air that comes out of the tubular wrap inevitably carries therewith some loose powdered material which must be collected and removed to prevent the same from dirtying the whole packer machine and above all from dirtying both the transverse sealing unit directly and the external surface of the tubular wrap in which the transversal sealing is to be carried out; in fact, in the presence of an excessive quantity of loose powdered product, the cross-sealing could not be carried out correctly. For this purpose, a suction device is arranged between the longitudinal sealing unit and the transverse sealing unit, configured for suctioning as much as possible all the loose powdered material that comes out of the tubular wrap.

The object of the present invention is to provide a packer machine for the production of pouches, each containing a portion of a loose product that allows to reach high productivity while guaranteeing high quality standards and, in particular, which allows to obtain optimal longitudinal seals even in the case of a double production line.

According to the present invention, a packer machine is provided for the production of pouches, each containing a portion of a loose product, according to what is claimed in the attached claims.

The present invention will now be described with reference to the attached drawings, which illustrate some non-limiting embodiments thereof, wherein:.

Number <NUM> in <FIG> denotes, as a whole, a snus pouch that contains inside a portion <NUM> of snus (namely, of a loose and moist nicotine-based product for oral use). The pouch <NUM> is closed by a longitudinal seal <NUM> and by two transverse seals <NUM>.

Number <NUM> in <FIG> and <FIG> denotes, as a whole, a packer machine that produces the snus pouches <NUM>.

The packer machine <NUM> is of the FFS ("Form, Fill and Seal") type, operates on a double line to make two snus pouches <NUM> at a time, and comprises a frame <NUM> (schematically and partially illustrated in <FIG>), which rests on a floor and has a vertical support wall on which all the operating components that contribute to the production of the snus pouches <NUM> are mounted.

The packer machine <NUM> comprises a conveyor device <NUM> (partially illustrated in <FIG> and <FIG>) for conveying a band of wrapping material along a straight packing path P (schematically illustrated in <FIG>). Along the packing path P a wrapping station S is arranged, where the band of wrapping material is wrapped to form a tubular wrap having a longitudinal development. Along the packing path P and downstream of the wrapping station S, a longitudinal sealing unit <NUM> is arranged to longitudinally seal the tubular wrap in the area of an overlapping section of the band of wrapping material so as to form the longitudinal seal <NUM>. Along the packing path P and downstream of the longitudinal sealing unit <NUM>, a transverse sealing unit <NUM> is arranged to transversely seal the tubular wrap so as to form an alternating succession of sealing sections (in the area of the transverse seals <NUM>) and sections containing a portion of loose product <NUM>. At the wrapping station S a feeding device <NUM> for the loose material is provided to feed, one after the other, the portions of loose product into the tubular wrap. Finally, along the packing path P and downstream of the transverse sealing unit <NUM>, a cutting unit (not illustrated) is arranged to transversely cut the tubular wrap in the area of the sealing sections (namely, the transverse seals <NUM>) so as to separate the single snus pouches <NUM>.

In the embodiment illustrated in the attached figures, the packer machine <NUM> operates on a double line, namely, it wraps two tubular wraps at the same time in order to make two snus pouches <NUM> at a time along two parallel and side by side packing paths P; namely, in a double-line packer machine <NUM>, all the operating components are "doubled" to simultaneously produce two twin and side by side tubular wraps. According to a different embodiment not illustrated, the packer machine <NUM> operates on a single line, namely, it wraps a single tubular wrap to obtain one snus pouch <NUM> at a time.

As illustrated in <FIG>, the feeding device <NUM>, in each production line (namely, in each packing path P), ends with a feeding duct <NUM> around which the wrapping material is bent so as to form the tubular wrap; each feeding duct <NUM> is configured to "shoot" (namely, insert) the portions <NUM> of loose product into the tubular wrap by means of compressed air. In the embodiment illustrated in <FIG>, each feeding duct <NUM> has a circular cross-section.

As illustrated in <FIG>, the longitudinal sealing unit <NUM> comprises along each feeding duct <NUM> a striker element <NUM> arranged upstream and a striker element <NUM> arranged downstream at a given distance from the striker element <NUM>; namely, along each feeding duct <NUM> two striker elements <NUM> and <NUM> are arranged in series, one after the other. In other words, the longitudinal sealing unit <NUM> comprises two striker elements <NUM> mounted next to one another on the two feeding ducts <NUM> and two striker elements <NUM> mounted next to one another on the two feeding ducts <NUM>. Generally, the striker elements <NUM> and <NUM> are made of a material having a low friction coefficient (such as, for example, polytetrafluoroethylene).

The longitudinal sealing unit <NUM> comprises two sealing elements <NUM>, each configured to carry out a longitudinal sealing of the corresponding tubular wrap.

According to the preferred embodiment, each sealing element <NUM> is a sealing roller <NUM>.

As illustrated in <FIG> and <FIG>, the longitudinal sealing unit <NUM> comprises two sealing rollers <NUM> (coaxial with one another), each of which is mounted so as to rotate around a horizontal rotation axis <NUM>, is heated by means of electrical resistance heaters, and is configured to carry out a longitudinal sealing cooperating with a corresponding striker element <NUM>.

Furthermore, the longitudinal sealing unit <NUM> comprises two sealing elements <NUM> each configured to carry out a longitudinal sealing of the corresponding tubular wrap.

In particular, the longitudinal sealing unit <NUM> comprises two sealing rollers <NUM> (coaxial one with the other), each of which is arranged downstream of a corresponding sealing roller <NUM>, is mounted so as to rotate around a rotation axis <NUM> parallel to the rotation axis <NUM>, is heated by means of electrical resistance heaters, and is configured to carry out the longitudinal sealing cooperating with a corresponding striker element <NUM>. In other words, the longitudinal sealing unit <NUM> comprises four sealing rollers <NUM> and <NUM>: two sealing rollers <NUM> that are coaxial one with the other and therefore arranged side by side along the packing path P and two sealing rollers <NUM>, which are coaxial one with the other and therefore arranged side by side along the packing path P. Basically, the sealing rollers <NUM> and <NUM> form the heated sealing heads whereas the striker elements <NUM> and <NUM> form the anvils against which the sealing heads press in order to apply the pressure necessary to carry out the heat sealing.

According to a preferred embodiment, the sealing rollers <NUM> have a side surface with a raised texture whereas the sealing rollers <NUM> have a smooth side surface: sealing rollers <NUM> having side surface with a raised texture also apply a longitudinal thrust to the tubular wrap to contribute to the movement of the tubular wrap whereas the sealing rollers <NUM> having smooth side surface only carry out the longitudinal seal <NUM> without applying a longitudinal thrust to the tubular wrap. It is preferable that only the sealing rollers <NUM> or only the sealing rollers <NUM> apply a longitudinal thrust to the tubular wrap, since if all the sealing rollers <NUM> and <NUM> apply a longitudinal thrust to the tubular wrap, between the sealing rollers <NUM> and the sealing rollers <NUM> the tubular wrap could be subjected to traction (in the event that the rotation speeds of the sealing rollers <NUM> and <NUM> were not exactly identical) which could damage the tubular wrap. According to other embodiments, all the sealing rollers <NUM> and <NUM> have a side surface with a raised texture or have a smooth side surface.

The longitudinal sealing unit <NUM> comprises two movable assemblies <NUM>, each of which is mounted on the frame <NUM> so as to move along a pressing direction independently of the other movable assembly <NUM> and supports one single corresponding sealing roller <NUM>. In particular, each movable assembly <NUM> is hinged to the frame <NUM> so as to rotate around a rotation axis <NUM> parallel to the rotation axes <NUM>. Furthermore, the longitudinal sealing unit <NUM> comprises two actuator devices <NUM>, each of which applies an elastic force directed along the pressing direction to a corresponding second movable assembly <NUM> independently of the other actuator device <NUM>.

Similarly, the longitudinal sealing unit <NUM> comprises two movable assemblies <NUM>, each of which is mounted on the frame <NUM> so as to move along a pressing direction independently of the other movable assembly <NUM> and supports one single corresponding sealing roller <NUM>. In particular, each movable assembly <NUM> is hinged to the frame <NUM> so as to rotate around a rotation axis <NUM> parallel to the rotation axes <NUM>. Furthermore, the longitudinal sealing unit <NUM> comprises two actuator devices <NUM>, each of which applies an elastic force directed along the pressing direction to a corresponding second movable assembly <NUM> independently of the other actuator device <NUM>.

In other words, each sealing element (roller) <NUM> or <NUM> perform a movement which is completely independent of the movement of the other sealing elements (rollers) <NUM> and <NUM> and therefore, in use, is completely free to always apply the optimum sealing pressure given by the corresponding actuator device <NUM> or <NUM> without being influenced by the other sealing elements (rollers) <NUM> and <NUM>.

According to a preferred embodiment, each actuator device <NUM> or <NUM> comprises a pneumatic spring provided with a pressure adjuster; in this way, in use, it is possible to precisely adjust the thrust that the actuator device <NUM> or <NUM> exerts on the corresponding sealing element (roller) <NUM> or <NUM> and therefore the pressure with which the corresponding sealing element (roller) <NUM> or <NUM> carries out the sealing. For example, a commercially available pressure adjuster allows the pressure inside the pneumatic springs to be varied with a resolution of the order of <NUM> bar, thus allowing a very fine adjustment of the thrust that the actuator device <NUM> or <NUM> exerts on the corresponding sealing element (roller) <NUM> or <NUM>.

The longitudinal sealing unit <NUM> comprises an actuator device <NUM> (generally a rotary electric motor) which is configured to cause the rotation (at least) of the sealing rollers <NUM> around the respective rotation axes <NUM>. According to a possible embodiment, the actuator device <NUM> is configured to cause the rotation around the respective rotation axes <NUM> only of the two sealing rollers <NUM>, which hence are driving elements, whereas the sealing rollers <NUM> are hinged in an idle manner around the respective rotation axes <NUM> and are driven elements; namely, the sealing rollers <NUM> exert a forward thrust on the tubular wrap whereas the sealing rollers <NUM> receive a forward thrust from the tubular wrap. According to an alternative embodiment, the sealing rollers <NUM> are driven while the sealing rollers <NUM> are driving. According to a further embodiment, all the sealing rollers <NUM> and <NUM> are driven or all the sealing rollers <NUM> and <NUM> are driving.

<FIG> and <FIG> illustrate the embodiment in which all the sealing rollers <NUM> and <NUM> are driving and in this embodiment, a corresponding toothed gear <NUM> is associated with each sealing roller <NUM> or <NUM>, which is carried by the respective movable assembly <NUM> or <NUM> and is angularly integral with the respective sealing roller <NUM> or <NUM>. The longitudinal sealing unit <NUM> comprises further toothed gears which are mounted on the same shaft caused to rotate by the actuator device <NUM> and each mesh with a corresponding toothed gear <NUM> so as to transmit the rotary motion to the respective sealing roller <NUM> or <NUM>. Thanks to the fact of using a single actuator device <NUM> to rotate all the driving sealing rollers <NUM> and <NUM>, all the driving sealing rollers <NUM> and <NUM> always rotate synchronously (namely, with the same rotation speed and with the same phase).

In other words, the longitudinal sealing unit <NUM> comprises heated sealing heads formed by the sealing elements (rollers) <NUM> and <NUM> that are movably mounted to be pushed with a calibrated elastic force (generated by the actuator devices <NUM> and <NUM>) against the respective striker elements <NUM> and <NUM>, which are mounted on the feeding ducts <NUM> and have a flat surface facing the sealing head. Therefore, in order to make the longitudinal seals <NUM>, the heated sealing heads made up of the sealing elements (rollers) <NUM> and <NUM> and the striker elements <NUM> and <NUM> "pinch" together the overlapping portion of the tubular wrap to simultaneously apply both heat (generated by the heated sealing heads) and mechanical compression.

According to the embodiment illustrated in <FIG> and <FIG>, each feeding duct <NUM> has a circular cross-section; according to a different embodiment illustrated in <FIG>, each feeding duct <NUM> has a cross-sectional shape with no circular symmetry and having a major axis <NUM> oriented (horizontally) parallel to a contact surface of the corresponding striker element <NUM> or <NUM> and a minor axis <NUM> oriented (vertically) perpendicularly to the contact surface of the corresponding striker element <NUM> or <NUM>. In this way, each element <NUM> or <NUM> can be wider and therefore provide a larger contact area for making the longitudinal seal <NUM> thus allowing to carry out a more solid longitudinal seal <NUM>. In this regard it is important to note that each element <NUM> or <NUM> cannot be wider than the respective feeding duct <NUM> to avoid having sharp edges which could lead to the tearing of the tubular wrap during its formation and its movement. Preferably, but not necessarily, each feeding duct <NUM> has an elliptical shape in cross section.

As better illustrated in <FIG> and <FIG>, the transverse sealing unit <NUM> comprises two opposite sealing rollers <NUM> that cooperate together to press one against the other (namely, together) the tubular wrap. The two sealing rollers <NUM> are mounted so as to rotate around two corresponding horizontal rotation axes (parallel to the rotation axes <NUM> and <NUM> of the sealing rollers <NUM> and <NUM>) and are rotated by the same actuator device.

An upper sucking device <NUM> is provided (illustrated in <FIG>), which is arranged between the longitudinal sealing unit <NUM> and the transverse sealing unit <NUM> above the tubular wraps (namely, above the packing path P) and has an upper suction opening <NUM> facing the tubular wraps (namely, the packing path P). Furthermore, a lower sucking device <NUM> is provided (illustrated in <FIG>), which is arranged between the longitudinal sealing unit <NUM> and the transverse sealing unit <NUM> under the tubular wraps (namely, under the packing path P) and has a lower suction opening <NUM> facing the tubular wraps (namely, the packing path P). In other words, the two sucking devices <NUM> and <NUM> are opposite one another to enclose the tubular wraps (namely, the packing path P) and therefore the two suction openings <NUM> and <NUM> face and are aligned to one another.

According to a preferred embodiment, the distance between the two suction openings <NUM> and <NUM> is shorter than twice the thickness of the tubular wraps; in this way the two suction openings <NUM> and <NUM> define between one another a relatively small volume (in any case sufficient to allow easy passage of the tubular wraps) and therefore the suction action exerted by the two sucking devices <NUM> and <NUM> is more effective.

According to a preferred embodiment, the suction opening <NUM> or <NUM> of each sucking device <NUM> or <NUM> lies on a plane parallel to the packing path P. According to a preferred embodiment, the suction opening <NUM> or <NUM> of each sucking device <NUM> or <NUM> has a rectangular shape.

The compressed air which is used to feed ("shoot") the portions <NUM> of loose product into the tubular wraps through the feeding ducts <NUM> is vented (namely, it is let out from inside the tubular wrap) between the longitudinal sealing unit <NUM> and the transverse sealing unit <NUM> in order to prevent the same from inflating the tubular wraps like "balloons". The compressed air that comes out of the tubular wraps inevitably carries therewith loose powdered material (lost from the portions <NUM> of loose product) which must be removed to prevent the same from dirtying the whole packer machine <NUM> and above all from directly dirtying the transverse sealing unit <NUM>, and the outer surface of the tubular wrap where the transversal sealing is to be carried out. In fact, in the presence of an excessive quantity of loose powdered product, the transverse seal <NUM> could not be carry outed correctly. For this purpose, the upper sucking device <NUM> (which is located above the tubular wrap, namely, above the packing path P) and the lower sucking device <NUM> (which is located under the tubular wrap, namely, under the packing path P) are arranged between the longitudinal sealing unit <NUM> and the transverse sealing unit <NUM>, and are configured for suctioning, as much as possible, all the loose powdered material that comes out of the tubular wraps.

According to a preferred embodiment illustrated in <FIG> and <FIG>, two nozzles <NUM> are provided, each of which is arranged upstream of the transverse sealing unit <NUM> along the packing path P and is configured to emit a jet of compressed air directed towards the transverse sealing unit <NUM>; in particular, the jets of compressed air emitted by the nozzles <NUM> are directed against a section sandwiched between the two sealing rollers <NUM> (namely, the area of the packing path P). Preferably, each nozzle <NUM> is arranged inside a respective sucking device <NUM> or <NUM> and is configured to emit the jet of compressed air through the suction opening <NUM> or <NUM> of the respective sucking device <NUM> or <NUM>. According to a different embodiment not illustrated, only one of the two nozzles <NUM> is provided instead of both nozzles <NUM>. The function of the nozzles <NUM> is to keep the transverse sealing unit <NUM> cleaner (particularly in the area comprised between the two sealing rollers <NUM>) to prevent the "dispersed" loose powdered material from negatively interfering with the execution of the transverse seals <NUM>.

According to a preferred embodiment illustrated in <FIG> and <FIG>, a cooling device <NUM> is provided, which is arranged downstream of the transverse sealing unit <NUM> along the packing path P and is configured to emit a jet of compressed air directed towards the tubular wraps (namely, towards the packing paths P). According to a preferred embodiment, the cooling device <NUM> comprises two parallel nozzles, each of which emits a jet of air directed towards a respective tubular wrap (namely, towards a respective packing path P). The cooling device <NUM> comprises a narrowing to cool the compressed air by means of the Venturi effect; namely, each nozzle of the cooling device <NUM> is fed through (at least) one duct in which a narrowing is made to cool the compressed air by means of the Venturi effect. In this way, the compressed air blown towards the tubular wraps after carrying out the transverse seals <NUM> is colder than the environment temperature and can cool the tubular wraps more effectively, stabilizing the just newly carried out seals <NUM> and <NUM> more quickly.

According to a possible embodiment illustrated in <FIG>, the packer machine <NUM> comprises a support plate <NUM> which directly supports the movable assemblies <NUM> and <NUM> and is mounted on the frame <NUM> so as to slide perpendicularly to the packing path P and perpendicularly to the rotation axes <NUM> and <NUM> between a work position (illustrated in the attached figures) in which the sealing rollers <NUM> and <NUM> are arranged along the packing path P and a maintenance position (not illustrated) in which the two sealing rollers <NUM> are separated (raised upwards) from the packing path P (to allow quick and easy access to the feeding ducts <NUM> of the feeding device <NUM>).

The packer machine <NUM> described above has numerous advantages. In the first place, the packer machine <NUM> described above allows to achieve high hourly productivity while ensuring a high-quality standard. This result is obtained, among other things, thanks to the fact that the packer machine <NUM> described above allows to obtain optimal longitudinal seals even in the case of a double production line; in particular, by making the movements of the sealing elements (rollers) <NUM> and <NUM> independent, each sealing element (roller) <NUM> and <NUM> always applies the optimum sealing pressure without being influenced by the other sealing elements (rollers) <NUM> and <NUM>. An independent adjustment of the movements of the sealing elements (rollers) <NUM> and <NUM> is particularly important, since the sealing elements (rollers) <NUM> and <NUM> press against the striker elements <NUM> and <NUM> (acting as anvils) that are integral with feeding the ducts <NUM>, which are mounted in a cantilevered manner and therefore are subject to variable, not entirely predictable, and significant flexures in use. This result is also obtained by using, on each production line, two successive sealing elements (rollers) <NUM> and <NUM>, which carry out the longitudinal seal <NUM> in two consecutive steps. This result is also obtained by increasing the quality of the transverse seals <NUM> thanks to the fact that the loose powdered material that comes out from the tubular wraps upstream of the transverse sealing unit <NUM> is effectively collected and removed, preventing the same from interfering negatively with the carrying out of the transverse seals <NUM>.

Furthermore, the packer machine <NUM> is particularly compact and allows an operator who is near the packer machine <NUM> to reach by hand all the various parts of the packer machine <NUM> without having to carry out unnatural movements.

Claim 1:
A packer machine (<NUM>) for the production of pouches (<NUM>) containing portions (<NUM>) of a loose product, in particular of the tobacco industry; the packer machine (<NUM>) comprises:
a frame (<NUM>);
a conveyor device (<NUM>) configured to move two bands of wrapping materials along two parallel packing paths next to one another;
a wrapping station (S) arranged along each packing path (P) and where the corresponding band of wrapping material is wrapped so as to form a tubular wrap having a longitudinal development;
a longitudinal sealing unit (<NUM>) to longitudinally seal each tubular wrap in the area of an overlapping section of the band of wrapping material; and
a feeding device (<NUM>) comprising two feeding ducts (<NUM>), around each of which a band of wrapping material is bent so as to form the corresponding tubular wrap and each of which is configured to feed, one after the other, the portions (<NUM>) of loose product into the corresponding tubular wrap;
wherein the longitudinal sealing unit (<NUM>) comprises two first sealing elements (<NUM>), each configured to carry out a longitudinal sealing of the corresponding tubular wrap;
the packer machine (<NUM>) is characterized in that the longitudinal sealing unit (<NUM>) comprises:
two first movable assemblies (<NUM>), each of which is mounted on the frame (<NUM>) so as to move along a pressing direction independently of the other first movable assembly (<NUM>) and supports one single corresponding first sealing element (<NUM>); and
two first actuator devices (<NUM>), each of which applies an elastic force directed along the pressing direction to a corresponding first movable assembly (<NUM>) independently of the other first actuator device (<NUM>).