COMPONENT MADE BY ADDITIVE MANUFACTURING . "

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no . 102020000029408 filed on December 2 , 2020 , the entire disclosure of which is incorporated herein by reference . TECHNICAL FIELD

The present invention relates to an operating machine to process smoking articles , for example a packing machine for the production of packs of cigarettes , a manufacturing machine for the production of cigarettes or cigarette filters , or a filterinserting machine for applying filters to cigarettes .

PRIOR ART

An operating machine to proces s smoking articles comprises numerous components assembled together .

Some of these components must be elastic, namely, they must have elasticity along at least one main direction ( or working direction) ; in other words , an elastic component must have the ability to elastically deform along the main direction .

An example of an elastic component is an application head which is configured to apply a sheet to a pack and has a sucking seat designed to house and hold the sheet ( in this case the main direction is perpendicular to the sucking seat ) . Normally, the application heads are provided in a packing machine to apply sheets (normally tax or closing stamps ) to corresponding packs of cigarettes ; in particular, a linear conveyor , which is configured to move the packs of cigarettes along a path and a rotatable drum, which supports at least one application head to cyclically move the application head between a pick-up station in which the application head picks up a sheet and a release station in which the application head presses the sheet (previously provided with glue ) against a corresponding pack of cigarettes carried by the conveyor are provided .

Currently, the application head is made elastic ( namely, capable of elastically deforming) by inserting a rubber part ; however, rubber has a relatively fast aging (particularly when it is subj ected to continuous mechanical stresses as occurs in a packing machine that performs hundreds of processing cycles per minute ) and therefore must be replaced frequently with consequent machine downtimes ( for maintenance ) which are particularly expensive as they reduce the ef ficiency of the packing machine . It is important to note that the frequent replacement of rubber parts entails a high cost not due to the cost of the rubber parts (which per se have a very low cost ) , but to the cost of the speciali zed operator who must intervene on the packing machine and, above all , for the cost of nonproduction when the packing machine is stopped . Furthermore , the coupling of the rubber part with the application head requires a complex procedure , as the rubber part must be assembled or vulcani zed (with the aid of a speci fic mould) directly on the application head .

The patent application DE102019107313A1 describes a handling or gripping device , in particular a suction clamp, provided with a suspension element which comprises a base body and a connection element elastically connected to the base body by means of a spring element .

DESCRIPTION OF THE INVENTION

The aim of the present invention is to overcome the aforementioned drawbacks , namely, to provide an operating machine to process smoking articles which is free from the drawbacks described above .

This aim is achieved by proposing an operating machine to process smoking articles according to the attached claims . The claims describe preferred embodiments of the present invention forming an integral part of the present description .

BRIEF DESCRIPTION OF THE DRAWINGS

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

• Figure 1 is a schematic and front view of a filter-inserting machine produced in accordance with the present invention;

• Figure 2 is a perspective and partially exploded view of part of a drum of a rotating conveyor of the filter-inserting machine of Figure 1 ;

• Figures 3 and 4 are two di f ferent perspective views of a circular sector of the rotating conveyor of Figure 2 ;

• Figure 5 is a schematic and front view of a labelling unit which is part of a cigarette packing machine ;

• Figure 6 is a schematic and front view of a di f ferent embodiment of the labelling unit of Figure 4 ;

• Figure 7 is a perspective and longitudinal section view of an application head of the labelling unit of Figure 5 or 6 ; and

• Figure 8 is a sectional view of the application head of Figure 7 .

PREFERRED EMBODIMENTS OF THE INVENTION

With reference to Figure 1 , number 1 denotes as a whole a filterinserting machine for applying filters to cigarettes (namely, an operating machine to process smoking articles ) .

The filter-inserting machine 1 comprises a plurality of rotating conveyors 2 , each of which is mounted so as to rotate with continuous motion around a central rotation axis 3 and supports laterally a series of sucking seats 4 ( illustrated in Figures 3 and 4 ) each designed to hold at least one corresponding cigarette and/or at least one corresponding filter . According to what is illustrated in Figures 2 , 3 and 4 , at least one rotating conveyor 2 comprises a central drum 5 ( only partially illustrated in Figure 2 ) which is mounted so as to rotate around the rotation axis 3 ( namely, it is rotatably fixed to a frame of the filter-inserting machine 1 ) and a plurality of circular sectors 6 ( only one of which is illustrated in Figures 3 and 4 ) which are fixed all around the periphery of the drum 5 so as to form a ring that surrounds the drum 5 itsel f . That is , the circular sectors 6 form a ring that covers the drum 5 and forms a shell that covers the drum 5 . The sucking seats 4 are obtained in the circular sectors 6 and openings lead into the periphery of the drum 5 , said openings couple with the circular sectors 6 to provide the circular sectors 6 with the necessary suction .

In the event of a format change, namely, when the filterinserting machine 1 has to process cigarettes ( and filters ) of various si zes ( in particular with a di f ferent diameter ) , it is necessary to modi fy the shape of the sucking seats 4 (which must reproduce the shape of the cigarettes/ filters in negative ) ; this operation requires the replacement of only the circular sectors 6 ( in which the sucking seats 4 are obtained) and does not require the replacement of the drums 5 and consequently is much faster and simpler ( it is much eas ier to disassemble/mount only the circular sectors 6 rather than a whole rotating conveyor 2 ) . In addition, a set of spare parts for a new cigarette/ filter format is signi ficantly cheaper and more compact ( the circular sectors 6 alone require much less material than complete rotating conveyors 2 ) . In other words , in each rotating conveyor 2 the corresponding drum 5 becomes part of a standard machine which is completely disconnected from the format of the smoking articles (namely, it is never replaced or adj usted during a format change ) while only the circular sectors 6 are parts of a format machine that must vary according to the format of the smoking articles (namely, they must be replaced during a format change ) .

Each circular sector 6 has a series of sucking seats 4 ( each designed to hold a substantially cylindrical smoking article ) and is configured to be mounted in a separable manner and with an interlocking system on the periphery of the drum 5 . According to a preferred embodiment illustrated in Figures 2 , 3 and 4 , the interlocking system is a dovetail j oint , namely, one single trapezoidal-shaped slot 7 ( female or mortise ) is obtained inside each circular sector 6 while one single trapezoidal-shaped tooth 8 (male or tenon) , which reproduces the shape of the slot 7 is obtained on the drum 5 ; in this way, the interlocking system only allows an axial sliding, namely, parallel to the rotation axis 3 , of a circular sector 6 relative to the drum 5 .

Each circular sector 6 has a geometric shape which gives the circular sector 6 itsel f an ability to elastically deform more along a main direction DI ( directed circumferentially and therefore perpendicularly to the rotation axis 3 ) than along two secondary directions D2 ( directed radially and therefore perpendicularly to the rotation axis 3 ) and D3 ( directed axially therefore parallel to rotation axis 3 ) which are perpendicular to one another and to the main direction DI . That is , each circular sector 6 has a greater elasticity along the main direction DI than along the two secondary directions D2 and D3 .

Each circular sector 6 is elastically deformed along the main direction DI so as to axially slide relative to the drum 5 and when the circular sector 6 is mounted on the drum 5 it presses elastically against the drum 5 along the main direction DI ; in other words , each tooth 8 of the drum 5 has a minimum circumferential interference with the slot 7 obtained in the circular sector 6 and therefore to fit the slot 7 on the tooth 8 it is necessary to elastically deform the circular sector 6 along the main ( circumferential ) direction DI , namely, it is necessary to circumferentially " widen" the slot 7 . According to a possible embodiment , each main circular sector 6 has a plurality of axially oriented incisions 9 . In particular , each circular sector 6 has an outer surface 10 which is opposite the drum 5 and has an alternation of troughs in the area of the sucking seats 4 and crests arranged between two troughs , or between two sucking seats 4 ; furthermore , each circular sector 6 has an inner surface 11 which is opposite the outer surface 10 , is arranged in contact with the drum 5 and has the plurality of incisions 9 , each of which is placed in the area of a crest of the outer surface 10 (namely, is aligned with a crest of the outer surface 10 ) . Preferably, in the area of each crest the circular sector 6 has a through channel 12 which is axially oriented and is af fected by a respective incision 9 ; namely, each incision 9 leads into a respective through channel 12 .

The open shape of each circular sector 6 gives the circular sector 6 a certain circumferential elasticity independently of the presence of the incisions 9 ; the presence of the incisions 9 considerably increases the circumferential elasticity of a circular sector 6 . By appropriately dimensioning the thickness of a circular sector 6 and the number/width of the incisions 9 , it is possible to change the elasticity of the circular sector 6 along the main direction DI (which, as already mentioned, is oriented circumferentially) .

It is important to underline that the circumferential elasticity of the circular sectors 6 also allows the circular sectors 6 to be created with a greater constructive tolerance , since the deviations from the nominal s i ze can be compensated by the elastic deformation of the circular sectors 6 .

Figures 5 and 6 illustrate a labelling unit 13 ( according to two di f ferent embodiments ) that is part of a packing machine 14 , which produces packs of cigarettes or applies transparent overwraps to packs of cigarettes . The packing machine 14 comprises a belt conveyor 15 which moves the packs of cigarettes along a straight and hori zontal path P and the labelling unit 13 cooperates with the belt conveyor 15 to apply sheets 16 ( typically tax or closing stamps ) to the packs of cigarettes carried by the belt conveyor 15 .

The labelling unit 13 comprises a rotating conveyor 17 which is mounted so as to rotate around a rotation axis 18 and supports at least one application head 19 to cyclically move the application head 19 between a pick-up station in which the application head 19 picks up a sheet 16 and a release station in which the application head 19 presses the sheet 16 (previously provided with glue ) against a pack of cigarettes carried by the belt conveyor 15 . In particular, each application head 19 has a sucking seat 20 (better illustrated in Figures 7 and 8 ) designed to house and hold a corresponding sheet 16 .

In the embodiment illustrated in Figure 5 , the rotating conveyor 17 supports a plurality of application heads 19 while in the embodiment illustrated in Figure 6 , the rotating conveyor 17 supports a single application head 19 .

As illustrated in Figures 7 and 8 , each application head 19 has a geometric shape which gives the application head 19 itsel f the ability to elastically deform more along a main direction DI ( directed perpendicularly to the sucking seat 20 and therefore radially relative to the rotation axis 18 ) than along to two secondary directions D2 and D3 (both directed parallel to the sucking seat 20 ) which are perpendicular to one another and to the main direction DI . That is , each application head 19 has a greater elasticity along the main direction DI than along two secondary directions D2 and D3 .

According to a preferred embodiment , each application head 19 has an intermediate portion 21 which is shaped like a bellows and extends along the main direction DI ; consequently, the bellows-like intermediate portion 21 gives the application head 19 an adequate ability to deform elastically along the main direction DI . By appropriately si zing the extension and thickness of the bellows-like intermediate portion 21 , it is possible to change the elasticity of the application head 19 along the main direction DI ; in particular, the more extended the bellows-like intermediate portion 21 , the greater the length of the maximum elastic deformation and the thinner the bellowslike intermediate portion 21 , the lower the elastic constant of the bellows-like intermediate portion 21 .

The circular sectors 6 of the filter-inserting machine 1 and the application heads 19 of the packing machine 14 are examples of components of an operating machine to process smoking articles which are advantageously manufactured by means of additive manufacturing; namely, each component ( circular sector 6 or application head 19 ) is one single monolithic piece , consists of one single indivisible body manufactured as a whole seamlessly and is manufactured by means of additive manufacturing . As previously stated, each component ( circular sector 6 or application head 19 ) has a geometric shape which gives the component an ability to deform more elastically along the main direction DI than along the two secondary directions D2 and D3 ; namely, the elasticity of each component ( circular sector 6 or application head 19 ) is not obtained using more elastic materials , but is obtained solely, thanks to the shape ( i . e . , the geometric shape ) that generates the desired elasticity . Consequently, each component ( circular sector 6 or application head 19 ) has a greater elasticity only along the main direction DI and not along the two secondary directions D2 and D3 .

Each component is made by additive manufacturing ( also called 3D printing) , or by an industrial process that 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 or Selective Laser Sintering also called SLS , Direct Laser Microfusion or DLM) .

According to a possible embodiment , at least one component ( circular sector 6 or application head 19 ) is made entirely of plastic material (plastic or resin) , namely, not of metal material ( essentially to reduce the production cost and weight ) , as each component in use is not subj ected to signi ficant mechanical stresses . Eventually the plastic material with which each component is made could be loaded ( reinforced) with carbon or glass to increase the structural characteristics ( for example Nylon 12CF is a carbon- f illed thermoplastic composite for 3D printing with excellent structural characteristics ) .

According to a di f ferent embodiment , at least one component ( circular sector 6 or application head 19 ) is made entirely of metal material .

Generally, the circular sector 6 is preferably made (by additive manufacturing) of a metal material since in use it is subj ected to greater mechanical stresses , while the application head 19 is preferably made (by additive manufacturing) of plastic material since , in use , is subj ected to lesser mechanical stresses .

The operating machine described above has numerous advantages .

Firstly, the components ( circular sectors 6 or appl ication heads 19 ) of the operating machine described above , which require a certain elasticity, obtain the desired elasticity without using rubber elements and therefore have an extremely long operating li fe ( therefore they do not need to be frequently replaced) .

Furthermore , the construction of the operating machine described above is particularly simple and inexpensive since the components ( circular sectors 6 or application heads 19 ) of the operating machine described above , which require a certain elasticity, can be manufactured quickly and inexpensively thanks to the manufacturing additive ; in fact the components ( circular sectors 6 or application heads 19 ) of the operating machine described above , which require a certain elasticity, are all manufactured in one piece without requiring any further mounting, assembly or co-moulding operations .