MACHINE FOR MAKING SMOKERS' ARTICLES

Technical field

This invention relates to a machine for making smokers' articles.

Background art

Generally speaking, smokers' articles are made by assembling two or more tubular elements or pieces to each other.

In particular, the pieces of smokers' articles are obtained by transversely cutting a single rod or stick whose length is a multiple of the length each individual piece.

The operation of cutting the rod, typically carried out by a disc knife, is of considerable importance because it defines the roundness of the piece obtained therefrom.

The roundness of the piece may cause the piece to be rejected if it does not fall within preset parameters.

In order to give the rod a clean cut, the disk knife is driven in rotation at high speeds and the cutting blade is sharpened periodically as a function of the working cycles of the machine.

Nevertheless, the moment the cutting blade impacts the surface of the rod, it tends to locally deform the rod, causing it to permanently lose its shape at the cut start zone.

This loss of shape, if excessive, may affect the roundness of the cut piece and cause the product to be rejected. Disclosure of the invention

The need is therefore felt for a machine which is capable of overcoming the above mentioned disadvantages.

Brief description of the drawings

The invention is described below with reference to the accompanying drawings, which illustrate a non-limiting embodiment of it and in which:

- Figure 1 is a schematic front view, with some parts cut away to better illustrate others, of a machine for making smokers' articles according to this invention;

- Figure 2 is a schematic perspective view showing a rod from which pieces of smokers' articles are obtained according to a first embodiment;

- Figure 3 is a perspective view, with some parts cut away in order to better illustrate others, of a second embodiment of the rod;

- Figure 4 is a perspective view, with some parts cut away in order to better illustrate others, of a third embodiment of the rod;

- Figure 5 is a schematic front view of a detail of a first embodiment of the machine of Figure 1 in a non-operating configuration;

- Figure 6 illustrates the detail of Figure 5 in an operating configuration;

- Figure 7 is a scaled-up view of a detail from Figure 6;

- Figure 8 illustrates a variant of the operating configuration of the detail of Figure 5;

- Figure 9 is a scaled-up view of a detail from Figure 8;

- Figure 10 is a schematic front view of a detail of a second embodiment of the machine of Figure 1 in a non-operating configuration;

- Figure 1 1 illustrates the detail of Figure 10 in an operating configuration;

- Figure 12 illustrates a variant of the operating configuration of the detail of Figure 1 1 . Detailed description of preferred embodiments of the invention

With reference to Figure 1 , the numeral 1 denotes in its entirety a machine for making smokers' articles not illustrated.

The smokers' articles referred to herein comprise at least one piece 3 of smokers' articles obtained by cutting a rod 2.

Two or more pieces 3 of smokers' articles are obtained by transversely cutting a single rod 2.

The term "rod" 2 is used to denote an at least partly hollow stick.

The rod 2 might, for example, comprise at least one solid portion alternated with at least one hollow portion.

In the embodiments illustrated, the rod 2 is a hollow stick.

The rod 2 has two free ends 8.

More specifically, the rod 2 is a tubular stick with cylindrical cross section. The rod 2 has a main axis "L" of longitudinal extension.

The rod 2 comprises at least one sheet 2a.

In the embodiment illustrated in Figure 2, the rod 2 comprises a single sheet, the outer sheet 2a, wound on itself.

In the embodiment illustrated in Figures 3 and 4, the rod 2 comprises at least one inner sheet 2b at least partly wrapped in the outer sheet 2a. Preferably, the inner sheet 2b is made of metallic material.

Preferably, the inner sheet 2b is made of aluminium.

Preferably, the outer sheet 2a is made of wrapping material.

More specifically, in the second embodiment illustrated in Figure 3, the rod 2 comprises an inner sheet 2b wrapped in the outer sheet 2a.

In this embodiment, the inner sheet 2b is equal in length to the outer sheet 2a or shorter in length than the outer sheet 2a.

In the third embodiment, illustrated in Figure 4, the rod 2 comprises an inner sheet 2b partly wrapped in the outer sheet 2a.

In this embodiment, the inner sheet 2b extends outwards from the end 8 of the outer sheet 2a of the rod 2. In embodiments which are not illustrated, the rod 2 comprises at least one outer sheet 2a and two or more inner sheets 2b wrapped one inside the other in a predetermined order.

In the embodiment illustrated in Figure 2, the rod 2 has a first internal diameter defined by the outer sheet 2a.

In the embodiment illustrated in Figures 3 and 4, the rod 2 has a second internal diameter defined by the inner sheet 2b.

The first internal diameter, defined by the outer sheet 2a, is smaller than the second internal diameter, defined by the inner sheet 2b.

The cross section of the rod 2 may be variable along the longitudinal axis L, in particular having a first internal diameter, defined by the outer sheet 2a, and a second internal diameter, defined by the inner sheet 2b and smaller than the first internal diameter.

The machine 1 comprises a hopper 4 for containing a mass 5 of filter rods 2.

The machine 1 comprises a roller 6 for withdrawing the rods 2 and located downstream of the hopper 4. More specifically, the bottom of the hopper 4 is closed by the withdrawal roller 6.

With reference to Figure 1 , the roller 6 rotates in anticlockwise direction about its axis of rotation 6a. The axis of rotation 6a is a horizontal axis normal to the plane of Figure 1 .

The withdrawal roller 6 is peripherally provided with a plurality of longitudinal flutes 9 running parallel to the axis 6a, each of which is capable of picking up and retaining a single rod 2 by suction.

The machine 1 comprises a transfer and retaining roller 10 located downstream of the hopper 4, in particular downstream of the withdrawal roller 6.

With reference to Figure 1 , the roller 10 rotates in a clockwise direction about its axis of rotation 10a. The axis of rotation 10a of the transfer and retaining roller 10 is a horizontal axis normal to the plane of Figure 1 . In particular, the transfer and retaining roller 10 rotates in a direction opposite to the rotation direction of the withdrawal roller 6.

The transfer and retaining roller 10 is peripherally provided with a plurality of longitudinal flutes 1 1 running parallel to the axis 10a, each of which is capable of retaining by suction a single rod 2 or pieces 3 obtained by cutting the rod.

The machine 1 comprises cutting means 12, in particular for transversely cutting the rods 2 into pieces 3.

In other words, the cutting means 12 cut the rods 2 transversely in such a way as to divide them into pieces 3.

More specifically, each rod 2 is divided into a first and a second piece 3a, 3b. Preferably, the pieces 3 are equal in length.

Preferably, the cutting means 12 are counter-rotating relative to the transfer and retaining roller 10 and, with reference to Figure 1 , rotate in anticlockwise direction.

The cutting means 12 face the transfer and retaining roller 10 and define therewith at least one cutting station 13.

Each flute 1 1 on the transfer and retaining roller 10, besides acting as an element for retaining individual rods 2, also acts as opposing means for opposing the cutting means 12 during the operation by which the rods 2 are cut.

The cutting means 12 comprise at least one disc knife 14 which rotates about its axis of rotation 14a, in particular parallel to the axis of rotation 10 of the transfer and retaining roller 10, and which has a circumferential cutting blade 15.

More precisely, at the cutting station 13, each disc knife 14 passes through respective radial slots made in the transfer and retaining roller 10 transversely to each flute 1 1 , in such a way as to cut each rod 2 transversely.

Each rod 2 has a cut start zone 18 where contact between the cutting means 12, in particular between the blade 15 of the disc knife 14, and the rod 2 first occurs.

In the embodiment described, the cut start zone 18 is exactly half way along the rod 2.

At the cut start zone 18, the cutting means 12 cut at least into a portion of the outer sheet 2a of the rod.

In the embodiment of the rod 2 illustrated in Figures 3 and 4, at the cut start zone 18, the cutting means 12 cut into a portion of the outer sheet 2a of the rod and of the inner sheet 2b beneath it.

Cutting of the rod 2, once started, is completed during the rotation of the transfer and retaining roller 10 about its axis 10a.

Downstream of the transfer and retaining roller 10, next along the path P, there is a staggering roller 16 whose function is to pick up the pieces 3 cut from a respective rod 2, stagger the positions of their axes and then transfer them towards the next operating station.

According to this invention, the machine 1 comprises opposing means 17 for opposing the cutting means 12 and capable, during the cutting action, of supporting from the inside of the rod 2 at least the portion of rod 2 in the proximity of the cut start zone 18.

The opposing means 17 oppose the action of the cutting blade 15 and hold in place at least the portion of rod 2 situated in the proximity of the cut start zone 18 of the rod 2.

With reference to the embodiment illustrated, the opposing means 17 are capable of supporting at least part of the inner sheet 2b of the rod 2 in the proximity of the cut start zone 18 of the rod 2.

This prevents deformation of the inner sheet 2b of the rod 2 caused by the localized pressure of the cutting means 12, in particular of the blade 15, on the rod 2 at the cut start zone 18

In this case, the opposing means 17 support the outer sheet 2a of the rod 2 at the portion of it which surrounds the respective portion of the inner sheet 2b on which the opposing means 17 operate.

The opposing means 17 are movable towards and away from the rod 2 to pass from a non-operating configuration to an operating configuration and vice versa.

The opposing means 17 move translationally at least in an axial direction defined by the longitudinal axis L of the rod 2.

More specifically, to pass from a non-operating configuration to an operating configuration, the opposing means 17 move translationally towards the rod 2.

To pass from an operating configuration to a non-operating configuration, the opposing means 17 move translationally away from the rod 2.

The opposing means 17 comprise a first and a second opposing element 19 and 20, each of which passes from a non-operating configuration to an operating configuration, and vice versa, relative to a respective end 8 of the rod 2.

That way, in their operating configuration, the first and second opposing elements 19 and 20 each act in conjunction with the respective end 8 of the rod 2.

In other words, the first and second opposing elements 19 and 20 are located on opposite sides of the rod 2.

To pass from a non-operating configuration to an operating configuration, and vice versa, the first and second opposing elements 19 and 20 move translationally in opposite directions along the same axial line.

In a first embodiment, illustrated in Figures 5 to 9, the first and second opposing elements 19 and 20 are configured to be inserted at least partly into the rod 2 through a respective end 8 of the rod 2.

The first and second opposing elements 19 and 20 have respective end portions 19a and 20a whose radial dimensions are smaller than the internal diameter of the cross section of the rod 2.

In the operating configuration, the first and second opposing elements 19 and 20 are positioned inside the rod 2 in such a way as to define a respective radial gap "R" with the portion of rod 2 in the proximity of the cut start zone 18, in particular with the inner sheet 2b of the rod 2.

In the operating configuration, the first and second opposing elements 19 and 20 are positioned inside the rod 2 in such a way as to define, relative to the longitudinal axis "L" of the rod 2, an axial distance "d" from each other which is just larger than the thickness of the cutting means 12, in particular of the cutting blade 15 of the disc knife 14.

In a variant of the first embodiment, in order to reduce or cancel the radial gap "R", the opposing means 17 are movable in a radial direction transverse to the longitudinal axis of extension L of the rod 2.

Thus, the possibility of the rod 2 being deformed at the cut start zone 18 is further reduced.

In order to reduce or cancel the radial gap "R", the first and second opposing elements 19 and 20 move translationally along the radial direction of the rod 2 after their translational movement along the rod's longitudinal axis "L" to be inserted into the rod 2, as illustrated in Figures 8 and 9.

In this case, the first and second opposing elements 19 and 20 along a respective radial line in the same feed direction.

Alternatively, the first and second opposing elements 19 and 20 rotate about an axis of rotation which is offset from the longitudinal axis "L" of the rod 2.

After the radial movement, the first and second opposing elements 19 and 20 are positioned inside the rod 2 in such a way as to contact respective portions of rod 2 in the proximity of the cut start zone 18, in particular respective portions of the inner sheet 2b of the rod 2 in the proximity of the cut start zone 18.

The end portions 19a and 20a of the first and second opposing elements 19 and 20 have respective surfaces which are shaped to mate with the portions of rod 2 contacted in the proximity of the cut start zone 18, in particular with the portions of the inner sheet 2b of the rod 2 in the proximity of the cut start zone 18.

More specifically, the end portions 19a and 20a of the first and second opposing elements 19 and 20 have respective cylindrical surfaces.

Once the rod 2 has been cut, the first and second opposing elements 19 and 20 move away from the respective portions of rod 2 in order to disengage them-

In a second embodiment, illustrated in Figures 10 to 12, at least one between the first and the second opposing element 19 and 20 is capable of conveying a pressurized fluid, in particular air, into the rod 2 through the respective end 8 of the rod 2 in such a way as to keep under tension at least the portion of rod 2 in the proximity of the cut start zone 18, in particular at least the portion of the inner sheet 2b of the rod 2 in the proximity of the cut start zone 18.

Advantageously, the tension inside the rod 2 created by the pressurized fluid prevents deformation of the rod 2 while it is being cut.

In a first variant, illustrated in Figures 10 and 1 1 , both the first and the second opposing element 19 and 20 are capable of conveying a pressurized fluid, in particular air, through the respective end 8 of the rod 2.

In a second variant, illustrated in Figure 12, the first opposing element 19 is capable of conveying a pressurized fluid, in particular air, through the respective end 8 of the rod 2, and the second opposing element 20 acts as a plug at the opposite end 8 of the rod 2.

In an alternative embodiment, the first and second opposing elements 19 and 20 contact the respective end 8 of the rod 2 in such a way as to create a fluid tight coupling, as illustrated for example in Figures 10 and 1 1 .

For this purpose, the respective end portions 19a and 20a of the first and second opposing elements 19 and 20 are made of a deformable material. To receive the end 8 of the rod 2, the end portions 19a and 20a each have a socket 21 for receiving the respective end 8 of the rod 2.

Alternatively, the first and second opposing elements 19 and 20 each draw near a respective end 8 of the rod 2 in such a way as to define therewith a gap 22 through which the pressurized fluid can flow, as illustrated for example in Figure 12.

Owing to the size of the rod 2 and the fluid pressures directed therein, the gap 22 does not negatively affect the pneumatic action of the opposing means 17 inside the rod 2.

In this case, the respective end portions 19a and 20a of the first and second opposing elements 19 and 20 are made of a rigid material.

Advantageously, this alternative solution allows limiting wear caused by friction on the ends 19a and 20a of the first and second opposing elements 19 and 20, thus increasing their working life.