CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no. 102020000029411 filed on December 2, 2020, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention falls within the technical field of the production of packs for smoking articles. In detail, the present invention relates to a hopper for a packer machine to pack smoking articles.

The present invention finds advantageous application in a cigarette hopper, to which the following specification will make explicit reference without thereby losing generality.

PRIOR ART

As is known, in the production of packs of cigarettes, hoppers are used to sort masses of smoking articles so as to be able to insert them, in groups or rows, into packaging material intended for making a pack.

A known type of hopper has a vertical extension and comprises: an input portion for the entry of cigarettes arranged in disorderly masses into the hopper, a plurality of output mouths, each of which comprises a plurality of vertical channels (or veins) for the exit of the cigarettes from the hopper (with the aid of suitable extracting means), and a connection area, which connects the input portion to the outlet mouths and is delimited by side walls with which the cigarettes come into contact during their descent path.

To date, there is an increasing need to boost the productivity of cigarette packing machines. Therefore, in hoppers, it is necessary to increase the speed of descent of the cigarettes toward the output mouths.

However, the increase in the speed of descent of the cigarettes toward the output mouths often causes blocks or undesired blockages of one or more output mouths in known type hoppers such as the one described above. These blockages are caused both because of the incorrect positioning, or orientation, of one or more cigarettes which, during the descent at high speed, causes the veins of the output mouths to close (or in any case slows down the descent of the other cigarettes) and because of the tobacco powder lost by the cigarettes which, by falling down by gravity, can accumulate in the channels, thereby slowing down or stopping the descent of the cigarettes. In case of blockage of one or more output mouths, it is normally necessary to stop the operation of the packer machine and it is always necessary for an operator to intervene by removing the blockage manually; consequently, blockages in the output mouths tend to decrease the long-term productivity of the packer machine, i.e., the number of packs of cigarettes correctly produced over a long period of time (for example, a conventional 8-hour work shift, a working day, a working week, a working month, a working year). In this regard, it is important to note that the best packer machine is not the one having the highest rated (theoretical) speed, but the one that manages to maintain the highest average speed in the long term.

Patent US4571917A discloses a unit for forming groups of cigarettes for a packer machine configured to pack cigarettes having an oval-shaped cross section.

DESCRIPTION OF THE INVENTION

The object of the present invention is to overcome the aforementioned drawbacks.

This object is achieved by proposing a hopper for a packer machine for smoking articles in accordance with the attached claims.

The claims describe preferred embodiments of the present invention forming an integral part of the present specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment thereof, wherein:

• Figure 1 is a schematic front view of a hopper made in accordance with the present invention;

• Figure 2 is a front perspective view of an output mouth of the hopper in Figure 1 ;

• Figure 3 is a perspective view of a detail of the output mouth in Figure 2;

• Figure 4 is a schematic cross-sectional view of a portion of the output mouth in Figure 2; and

• Figure 5 is a rear perspective view of an output mouth of the hopper in Figure 1. PREFERRED EMBODIMENTS OF THE INVENTION

With reference to Figure 1, number 1 indicates a cigarette hopper which is an (initial) part of a cigarette packing machine.

The hopper 1 has a vertical extension and comprises six output mouths 2 (referenced to by the letters A-F) from which groups of cigarettes are extracted in succession by means of six corresponding extraction devices. Each extraction device is coupled to a corresponding output mouth 2 of the hopper 1 and is designed to cyclically extract a group of cigarettes from the output mouth 2 to insert the group of cigarettes in a corresponding compartment of a forming conveyor stationary in front of the output mouth 2.

The hopper 1 comprises an upper part 3 and a lower part 4, both of which are delimited at the front and at the rear by respective vertical walls. The lower part 4 of the hopper 1 comprises the six lower output mouths 2, which are equidistant from each other and divided internally by a plurality of dividing walls 5 or partitions which define channels 6, within which the cigarettes are arranged in substantially vertical stacks.

Starting from an upper input, the upper part 3 of the hopper 1 is divided into two separate and specular channels 7, which are arranged on the right and the left, respectively, and lead into at least one free chamber 8 belonging to the lower part 4 of the hopper 1 and arranged immediately above the output mouths 2. In the embodiment shown in the attached figure, two twin, specular chambers 8 are provided, which are insulated from each other (i.e., the cigarettes cannot move from one chamber 8 to the other chamber 8), and each chamber 8 receives the cigarettes from a single channel 7 and feeds the cigarettes to three corresponding output mouths 2; according to an alternative embodiment, not shown, a single chamber 8 is provided, which receives the cigarettes from both channels 7 and feeds the cigarettes to all six output mouths 2. According to a further embodiment, not shown, a single channel 7 is provided, which feeds the cigarettes to a single chamber 6.

The cigarettes run through the hopper 1 and descend by gravity from top to bottom along a vertical output direction D; accordingly, the cigarettes entering the hopper 1 from above are divided into two flows which, travelling along the two channels 7, reach the two chambers 8 from which the cigarettes enter the channels 6 which end in the six output mouths 2.

As shown in Figure 2, each output mouth 2 consists of one single monolithic piece consisting of one single indivisible body manufactured as a whole, seamlessly. In particular, each output mouth 2 is manufactured by means of additive manufacturing (also called 3D printing), that is by means of an industrial process which, starting from a digital 3D model, creates the piece by adding one layer on top of the other (some examples of technologies that can be used in additive manufacturing are stereolithography, fused deposition modelling, also called FDM, selective laser sintering, also called SLS, or direct laser melting, i.e., DLM). According to a preferred embodiment, each output mouth 2 is made entirely of metal material (for example aluminium) to better resist wear and since the thickness of some parts is very thin (and therefore not very resistant if made of plastic material). According to a different embodiment, each output mouth 2 could in any case be made entirely of plastic material (plastic or resin), or of non-metallic material (essentially to reduce production cost and weight), since each output mouth 2 in use is not subjected to significant mechanical stress (it only has to guide the descent of the cigarettes laterally by gravity). Optionally, the plastic material of which each output mouth 2 is made could be filled (reinforced) with carbon or glass to enhance the structural characteristics (for example, Nylon 12CF is a carbon-filled thermoplastic composite for 3D printing with excellent structural characteristics).

Each output mouth 2 has a flat rear wall 9 (better shown in Figure 5) from which the dividing walls 5 delimiting the channels 6 rise up perpendicularly; as stated above, the dividing walls 5 are not connected successively to the rear wall 9 but form one single indivisible body seamlessly with the rear wall 9.

As better shown in Figures 3 and 4, each dividing wall 5 has a central part which, instead of being flat, has a series of ribs 10, which alternate crests 11 (which rise up towards the centre of the corresponding channel 6) and troughs 12 (further away from the centre of the corresponding channel 6). When the cigarettes (shown in broken lines in Figure 4) descend inside the channels 6, they only rest on the crests (peaks) 11 of the ribs 10, and therefore the contact surface between a cigarette and the dividing walls 5 delimiting the channel 6 in which the cigarette is located is extremely limited, since it essentially only consists of the crests 11 of the ribs 10.

In one face of each dividing wall 5, the ribs 10 are parallel to one another and are oriented longitudinally relative to the corresponding channel 6; that is, the ribs 10 have a substantially vertical orientation which extends from top to bottom following the course of the corresponding channel 6.

According to a preferred embodiment shown in the accompanying figures, each rib 10 has, in cross-section, a triangular (equilateral) shape; moreover, each crest 11 of a rib 10 (coinciding with a vertex of the triangular cross-section) has a sharp edge (i.e., an acute, non-bevelled and non-rounded edge).

According to a preferred embodiment shown in the accompanying figures, each dividing wall 5 has (centrally) a central portion provided with the ribs 10, and (laterally) two smooth side portions (i.e., flat, therefore without ribs 10), which are arranged on the opposite sides of the central portion.

The embodiments described herein may be combined with each other without departing from the scope of protection of the present invention.

The hopper 1 described above has many advantages.

Firstly, the hopper 1 described above makes it possible to significantly reduce, at the same speed of descent of the cigarettes, the frequency of obstruction of the output mouths 2, i.e., blockages that prevent the cigarettes from falling properly and that usually have to be manually removed by an operator.

The reduction in the blockage iteration of the output mouths 2 is obtained by reducing the friction between the cigarettes and the dividing walls 5 of the channels 6 (due to the presence of the ribs 10), which favours the downward fall of the tobacco powder lost by the cigarettes, thus preventing the tobacco powder from stopping on the dividing walls 5 of the channels 6, which increases the friction coefficient of the dividing walls 5. Furthermore, the reduction of the friction between the cigarettes and the dividing walls 5 of the channels 6 (due to the presence of the ribs 10) also allows a more fluid descent of the cigarettes along the channels 6 and therefore lowers the stresses transmitted to the cigarettes contained in the chambers 8, thus reducing the possibility that the cigarettes contained in the chambers 8 receive abnormal thrusts which may trigger a “sideways positioning". In particular, the friction between the cigarettes and the dividing walls 5 of the channels is reduced by the presence of the ribs 10, both because the ribs 10 considerably decrease the contact surface between the dividing walls 5 of the channels 6, and because the ribs 10 facilitate (favour) the downward fall of the tobacco powder into the free spaces between the crests 11 (i.e., into the troughs 12).

Moreover, the increase in the production cost of the hopper 1 described above is modest compared to a similar known hopper; in fact, when the output mouths 2 of the hopper 1 described above are produced by means of additive manufacturing, the hopper 1 as a whole has a lower production cost than a similar known hopper (even in the absence of the ribs 10). In fact, a known output mouth has a higher number of components (generally thirteen-fifteen) compared to an output mouth 2 manufactured by means of additive manufacturing (which, instead, is made of a single component), and therefore, an output mouth 2 manufactured by means of additive manufacturing has a zero assembly time (since it is a single piece, it has no components to be assembled together); moreover, an output mouth 2 manufactured by means of additive manufacturing has a 30-40% less weight compared to a known output mouth. Overall, an output mouth 2 manufactured by means of additive manufacturing allows a 20-25% reduction in production cost compared to a similar known output mouth. It is therefore clear that it is advantageous to provide an output mouth 2 by means of additive manufacturing regardless of the presence of the ribs 10.

Lastly, it is simple to update an existing hopper 1 only by replacing the existing output mouths with corresponding output mouths 2 manufactured by means of additive manufacturing and provided with the ribs 10.