CROSS-REFERENCE TO RELATED APPLICATIONS
TECHNICAL FIELD
[0002] The present invention relates to a transport drum.
[0003] The present invention can be applied advantageously to a transport drum for moving
wrapping sheets (in particular made of metallized paper) intended for the production
of wraps of rigid packs of cigarettes with hinged lids, to which the following discussion
will make explicit reference without any loss of generality.
PRIOR ART
[0004] A rigid pack of cigarettes with a hinged lid comprises a wrap consisting of a group
of cigarettes wrapped in a sheet of metallized paper and a rigid outer shell which
houses the wrap therein. The outer shell consists of a cup-shaped container, which
houses the group of cigarettes and has an open upper end, and a lid, which is also
cup-shaped and is hinged to the container so as to rotate, relative to the container,
between an open position and a closed position of the open end.
[0005] A cigarette packer machine, for example as described in the patent application
EP3725691A1, comprises a wrapping unit in which wraps intended to be successively inserted into
rigid outer shells are produced by folding wrapping sheets made of metallized paper
around the respective groups of cigarettes, the wrapping sheets being separated by
transversely cutting a band of wrapping material unwound from a reel. In particular,
a wrapping-sheet supply unit comprises one or more suctioning transport drums (i.e.
provided with a series of suction holes that are cyclically connected to a suction
source) around which the wrapping sheets are wound so as to move the wrapping sheets
towards a folding area.
[0006] To ensure a proper adhesion of a wrapping sheet to the outer surface of a transport
drum, it is necessary for the suction holes to be arranged on two circumferences close
to the edges of the wrapping sheet. To adjust a transport drum to wrapping sheets
of different widths, it is necessary to provide a series of transport drums, each
having the suction holes arranged with different spacings, whereby it is necessary
to mount each time the appropriate transport drum for the format of the wrapping sheet
it is desired to use; however, this solution is particularly expensive (it being necessary
to produce different transport drums) and involves quite a long format-change operation
(removing a transport drum and mounting a new one requires a lot of time and the intervention
of a particularly skilled technician).
[0007] In order to at least partially resolve these drawbacks, it has been proposed to make
a single transport drum with a series of suction-hole circumferences with different
spacings and then to close (by means of disposable plugs which are temporary and removable)
the suction holes that are not used as a function of the format of the wrapping sheet
it is desired to use; this solution greatly reduces costs (the disposable plugs are
small pieces of plastic that are very modest in cost) but still involves a fairly
long format-change operation (removing the old disposable plugs and inserting new
ones when the transport drum is mounted in the packer machine is a relatively simple
operation, but quite slow). The patent application
EP1457444A2 describes a roller for transporting a band or sheet of paper in paper-converting
machines, for example, a rewinding machine, a winding machine, an interfolding machine;
the roller consists of an outer cylindrical body equipped with a plurality of radial
holes, arranged according to longitudinal rows, capable of rotating with respect to
a fixed inner body coaxial to it and connected to a suction system.
[0008] The patent application
US2006261120A1 describes a roller configured to select and remove pieces that have been cut or severed
from a band or sheet of flexible material; the roller comprises an external surface
with a plurality of through apertures and a plurality of valves in fluid communication
with the plurality of apertures.
DESCRIPTION OF THE INVENTION
[0009] The object of the present invention is to provide a transport drum which makes it
possible to perform, quickly and at a lost cost, a format-change operation designed
to allow the supply of a product of a different size.
[0010] According to the present invention, a transport drum is provided as claimed in the
appended claims.
[0011] The claims describe embodiments of the present invention and constitute an integral
part of the present description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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 perspective and schematic view of a part of a cigarette packer machine
provided with a wrapping-sheet supply device;
- Figure 2 is a front perspective view of a transport drum of the supply device of Figure
1;
- Figure 3 is a front perspective and partially sectioned view of the transport drum
of Figure 2;
- Figure 4 is a rear perspective view, with parts removed for clarity, of the transport
drum of Figure 2;
- Figure 5 is a rear perspective and exploded view of the transport drum of Figure 2;
- Figure 6 is a perspective view of a group of distribution pipes of the transport drum
of Figure 2; and
- Figures 7 and 8 are two different cross-sectional views of a part of the transport
drum of Figure 2.
PREFERRED EMBODIMENTS OF THE INVENTION
[0013] In Figure 1, the reference number 1 indicates, as a whole, a packer machine which
produces a rigid pack 2 of cigarettes with a hinged lid comprising a cup-shaped outer
container made of rigid cardboard or paperboard and a wrap 3 accommodated inside the
container 2. Each wrap 3 consists of a wrapping sheet 4 made of metallized paper,
which is folded around a group 5 of cigarettes that is parallelepiped in shape.
[0014] The packer machine 1 comprises a forming unit (not illustrated) in which the groups
5 of cigarettes are formed in succession, a wrapping unit 6 in which a respective
wrapping sheet 4 is wrapped around each group 5 of cigarettes so as to produce a wrap
3, and a wrapping unit (not illustrated) in which a collar and a blank are wrapped
around each wrap 3 so as to produce an outer container provided with a lid.
[0015] The wrapping unit 6 comprises a supply device 7 which cyclically supplies the wrapping
sheets 4 into the folding area, i.e. arranges each wrapping sheet 4 in such a manner
that the wrapping sheet 4 is intercepted by a corresponding group 5 of cigarettes
moving along a wrapping path. The supply device 7 comprises an unwinding station in
which a band 8 of wrapping material is unwound from a reel 9 and is moved towards
a cutting member 10 of a known type which cyclically performs a cross cut of the band
8 of wrapping material so as to separate the individual wrapping sheets 4 from the
band 8 of wrapping material. Arranged in succession downstream of the cutting member
are two suctioning transport drums 11 (i.e. which hold the wrapping sheets 4 through
suction), which move the wrapping sheets 4 to the wrapping area.
[0016] As illustrated in Figures 2 and 3, each transport drum 11 comprises a cylindrical
body 12, which is mounted in a rotary manner around a rotation axis 13 and which has
a side surface 14 that is cylindrical in shape, around which the wrapping sheets 4
moved by the transport drum 11 are wound in use. A plurality of suction openings 15
open through the side surface 14 and, in use, are connected (in the manner described
in the following) to a suction source 16 (schematically illustrated in Figure 2) so
as to hold the wrapping sheets 4 through suction on the side surface 14.
[0017] The suction openings 15 are arranged in groups 17 configured to adjust to different
formats of the wrapping sheets 4 (in particular to different widths of the wrapping
sheets 4, i.e. to different axial dimensions, measured parallel to the rotation axis
13, of the wrapping sheets 4); in particular, three different groups 17 of suction
openings 15 configured to adjust to three different formats of the wrapping sheets
4 are provided. Each group 17 of suction openings 15 comprises two circular and lateral
rows of suction openings 15 arranged laterally and one circular and central row of
suction openings 15: the one circular and central row of suction openings 15 is common
to all three groups 17 of suction openings 15 while each group 17 of suction openings
15 comprises two circular and lateral rows of dedicated suction openings 15, i.e.
which only form part of one group 17 of suction openings 15 and do not form part of
the other groups 17 of suction openings 15.
[0018] As a function of the format (size) of the wrapping sheets 4 that are to be handled,
each transport drum 11 must be configured so as to enable the group 17 of suction
openings 15 corresponding to the selected format and disable the groups 17 of suction
openings 15 that do not correspond to the selected format; only in this manner, in
fact, is it possible to obtain at the same time an adequate adhesion of the wrapping
sheets 4 to the side surface 14 of the cylindrical body 12 and a congruous
"consumption" of suction (by avoiding the application of suction through suction openings 15 which
in use are never covered by the wrapping sheets 4).
[0019] As better illustrated in Figure 3, each transport drum 11 comprises a plurality of
supply channels 18, which are obtained inside the cylindrical body 12, are axially
oriented (i.e. parallel to the rotation axis 13) and are distributed (not completely
uniformly, i.e. not everywhere with the same pitch) around the rotation axis 13. Furthermore,
and as better illustrated in Figures 7 and 8, each transport drum 11 comprises a plurality
of suction ducts 19, each of which is radially oriented (i.e., perpendicularly to
the rotation axis 13), originates from a respective supply channel 18 and is directed
towards the outside of the cylindrical body 12, ending in a respective suction opening
15 which opens through the side surface 14 of the cylindrical body 12. In other words,
each suction opening 15 corresponds to a respective supply channel 18, and vice versa,
so that, exactly as the three groups 17 of suction openings 15 were defined, three
groups 17 of supply channels 18 are defined analogously.
[0020] As better illustrated in Figure 3, each transport drum 11 comprises a plurality of
distribution pipes 20, each of which is inserted inside a respective supply channel
18 so as to rotate around a rotation axis 21 parallel to the rotation axis 13 and
can be connected to the suction source 16. Furthermore, and as better illustrated
in Figures 7 and 8, each distribution pipe 20 comprises a plurality of through holes
22, each of which can be aligned with a corresponding suction duct 19 by suitably
rotating the distribution pipe 20 around the rotation axis 21 in order to establish
a connection between the suction duct 19 and the suction source 16. Figure 7 shows
an example where through holes 22 of a few distribution pipes 20 are not aligned with
the respective suction ducts 19 (so that the suction ducts 19 are isolated from the
respective distribution pipes 20 and from the suction source 16), while Figure 8 shows
an example where through holes 22 of a few distribution pipes 20 are aligned with
the respective suction ducts 19 (so that the suction ducts 19 are connected to the
respective distribution pipes 20 and to the suction source 16).
[0021] As better illustrated in Figures 7 and 8, the through holes 22 of each distribution
pipe 20 are angularly misaligned relative to one another, i.e. in each distribution
pipe 20, only the through holes 22 corresponding to a same format of the wrapping
sheet 4 are angularly aligned with one another. In this manner, the through holes
22 of each distribution pipe 20 are arranged so as to be aligned with a single group
17 of suction ducts 19 at a time depending on the angular position of the distribution
pipe 20 relative to the corresponding supply channel 18.
[0022] As better illustrated in Figures 4, 5 and 6, each transport drum 11 comprises a transmission
system 23, which connects all distribution pipes 20 to one another and synchronizes
the rotation of all distribution pipes 20 relative to the corresponding rotation axes
21. Thus, by imparting a rotation to a single distribution pipe 20, the same identical
rotation is transmitted to all the other distribution pipes 20 because of the action
of the transmission system 23. In particular, the transmission system 23 comprises,
for each distribution pipe 20, a corresponding peripheral (satellite) gear wheel 24,
which is integral to the distribution pipe 20 (for example, is screwed into the distribution
pipe 20); in addition, the transmission system 23 comprises a central (solar) gear
wheel 25, which is mounted in a rotary manner on the cylindrical body 12 so as to
rotate around the rotation axis 13 and meshes with all peripheral gear wheels 24,
so that the rotational movement of all peripheral gear wheels 24 is always synchronized.
[0023] According to a preferred embodiment, the transmission system 23 comprises a braking
device, which applies a friction to the central gear wheel 25 in order to counter
the rotation of the central gear wheel 25 around the first rotation axis 13. Preferably,
the braking device comprises a friction ring 26 made of an elastic material, which
is interposed between the cylindrical body 12 and the central gear wheel 25 and presses
against a surface of the central gear wheel 25. The function of the braking device
is to make the rotation of the central gear wheel 25 relative to the cylindrical body
12 and around the rotation axis 13 (and thus the rotation of all peripheral gear wheels
24 around their respective rotation axes 21)
"difficult", i.e. to require the application of a high driving torque to obtain the rotation of
the central gear wheel 25 relative to the cylindrical body 12 and around the rotation
axis 13 (and thus the rotation of all peripheral gear wheels 24 around their respective
rotation axes 21); in this manner, in use, the peripheral gear wheels 24 do not rotate
around their respective rotation axes 21 in an uncontrolled and undesirable manner
because of the forces to which they are subjected due to the rotation of the cylindrical
body 12 around the rotation axis 13. In other words, the function of the braking device
is to lock the angular position of the peripheral gear wheels 24 (i.e. of the distribution
pipes 20) during normal use of the transport drum 11 in such a manner that the configuration
of the transport drum 11 cannot be modified in an uncontrolled and undesirable manner
during normal use of the transport drum 11.
[0024] According to a preferred embodiment, each peripheral gear wheel 24 has, at the centre,
a dead hole 27 (so as to maintain the pneumatic isolation of the respective distribution
pipe 20), which has a non-circular shape (for example, a hexagonal shape as illustrated
in Figures 7 and 8 or a star shape) and is designed to be engaged by a tip of a tool
shaped so as to apply a rotational torque. Typically, the tool is inserted inside
a distribution pipe 20 from the side opposite the peripheral gear wheel 24 and thus
has an appropriate length (i.e. longer than the axial length of the distribution pipe
20).
[0025] According to a preferred embodiment best illustrated in Figure 3, each supply channel
18 is a through channel so that a rear end of each distribution pipe 20 axially projects
out of the cylindrical body 12 and supports the respective peripheral gear wheel 24.
[0026] Each transport drum 11 comprises a pneumatic distributor (known and not illustrated),
which is arranged at an end of the cylindrical body 12 opposite the end at which the
peripheral gear wheels 24 are arranged and which is configured to connect the distribution
pipes 20 to the suction source 16.
[0027] In the non-limiting embodiment described above, the suctioning transport drum 11
is configured to move a wrapping sheet 4; according to other embodiments not illustrated,
the transport drum 11 could be configured to move another type of product of a flat
shape or even of another shape (for example of a cylindrical shape such as cigarettes,
cigarette filters, cigarette components, components for cigarette filters...).
[0028] The embodiments described herein can be combined with one another without departing
from the scope of protection of the present invention.
[0029] The transport drum 11 described in the foregoing has numerous advantages.
[0030] First, the transport drum 11 described above makes it possible to perform, quickly
and at a low cost, a format-change operation designed to allow the supply of a product
of a different size; in fact, it is sufficient to apply a rotation (with an ordinary
tool available in any workshop) to a peripheral gear wheel 24 in order to transmit
the same rotation to all other peripheral gear wheels 24 and thereby quickly adjust
the angular position of all distribution pipes 20 and establish which group 17 of
suction openings 15 (or which group 17 of suction ducts 19) must be pneumatically
connected to the distribution pipes 20 so as to receive suction from the distribution
pipes 20.
[0031] Furthermore, by calibrating the angular position of the distribution pipes 20, it
is also possible to not open the passage to the suction ducts 19 completely, thereby
throttling the suctioning action and thus mechanically calibrating the degree of suction
that is exerted through the suction openings 15.
[0032] Finally, the transport drum 11 described above is of a relatively simple and economical
design.
LIST OF THE REFERENCE NUMBERS OF THE FIGURES
[0033]
- 1
- packer machine
- 2
- pack of cigarettes
- 3
- wrap
- 4
- wrapping sheet
- 5
- group of cigarettes
- 6
- wrapping unit
- 7
- supply device
- 8
- band
- 9
- reel
- 10
- cutting member
- 11
- transport drums
- 12
- cylindrical body
- 13
- rotation axis
- 14
- side surface
- 15
- suction opening
- 16
- suction source
- 17
- group
- 18
- supply channels
- 19
- suction ducts
- 20
- distribution pipes
- 21
- rotation axis
- 22
- through holes
- 23
- transmission system
- 24
- peripheral gear wheel
- 25
- central gear wheel
- 26
- friction ring
- 27
- dead hole
1. A transport drum (11) to transport a product (4) and comprising:
a cylindrical body (12), which is mounted in a rotary manner around a first rotation
axis (13);
a plurality of supply channels (18), which are obtained inside the cylindrical body
(12), are axially oriented and are distributed around the first rotation axis (13);
and
a plurality of suction ducts (19), each of which is radially oriented, originates
from a respective supply channel (18) and is directed towards the outside of the cylindrical
body (12);
the transport drum (11) is characterized in that:
a plurality of distribution pipes (20) is provided, each of which is inserted inside
a respective supply channel (18) so as to rotate around a second rotation axis (21)
parallel to the first rotation axis (13) and can be connected to a suction source
(16); and
each distribution pipe (20) comprises a plurality of through holes (22), each of which
can be aligned with a corresponding suction duct (19) by suitably rotating the distribution
pipe (20) around the second rotation axis (21) in order to establish a connection
between the suction duct (19) and the suction source (16).
2. The transport drum (11) according to claim 1, wherein the through holes (22) of each
distribution pipe (20) are angularly misaligned relative to one another.
3. The transport drum (11) according to claim 1 or 2, wherein:
in each distribution pipe (20), only the through holes (22) corresponding to a same
format of the product (4) are angularly aligned with one another; and
at least two different groups of through holes (22) corresponding to different formats
of the product (4) are present.
4. The transport drum (11) according to claim 1, 2 or 3, wherein the suction ducts (19)
are divided into at least two distinct groups (17) configured to adjust to two different
formats of the product (4).
5. The transport drum (11) according to claim 4, wherein the through holes (22) of each
distribution pipe (20) are arranged so as to be aligned with a single group (17) of
suction ducts (19) at a time depending on the angular position of the distribution
pipe (20) relative to the corresponding supply channel (18).
6. The transport drum (11) according to one of the claims from 1 to 5 and comprising
a transmission system (23), which connects all distribution pipes (20) to one another
and synchronizes the rotation of all distribution pipes (20) relative to the corresponding
second rotation axes (21).
7. The transport drum (11) according to claim 6, wherein, by imparting a rotation to
a single distribution pipe (20), the same identical rotation is transmitted to all
the other distribution pipes (20) because of the action of the transmission system
(23).
8. The transport drum (11) according to claim 6 or 7, wherein the transmission system
(23) comprises, for each distribution pipe (20), a corresponding peripheral gear wheel
(24), which is integral to the distribution pipe (20).
9. The transport drum (11) according to claim 8, wherein the transmission system (23)
comprises a central gear wheel (25), which is mounted in a rotary manner on the cylindrical
body (12) so as to rotate around the first rotation axis (13) and meshes with all
peripheral gear wheels (24).
10. The transport drum (11) according to claim 9, wherein the transmission system (23)
comprises a braking device, which applies a friction to the central gear wheel (25)
in order to counter the rotation of the central gear wheel (25) around the first rotation
axis (13).
11. The transport drum (11) according to claim 10, wherein the braking device comprises
a friction ring (26) made of an elastic material, which is interposed between the
cylindrical body (12) and the central gear wheel (25) and presses against a surface
of the central gear wheel (25).
12. The transport drum (11) according to one of the claims from 8 to 11, wherein each
supply channel (18) is a through channel so that a rear end of each distribution pipe
(20) axially projects out of the cylindrical body (12) and supports the respective
peripheral gear wheel (24).
13. The transport drum (11) according to one of the claims from 8 to 12, wherein each
peripheral gear wheel (24) has, at the centre, a dead hole (27), which has a non-circular
shape and is designed to be engaged by a tip of a tool shaped so as to apply a rotation
torque.
14. The transport drum (11) according to one of the claims from 6 to 13, wherein the transmission
system (23) comprises a braking device, which applies a friction to each distribution
pipe (20) in order to counter the rotation of the distribution pipe (20) around the
respective second rotation axis (21).
15. The transport drum (11) according to one of the claims from 1 to 14 and comprising
a pneumatic distributor, which is arranged at an end of the cylindrical body (12)
and is configured to connect the distribution pipes (20) to the suction source (16).
16. The transport drum (11) according to one of the claims from 1 to 15, wherein each
suction duct (19) leads to a suction opening (15), which opens through a side surface
(14) of the cylindrical body (12).
17. The transport drum (11) according to one of the claims from 1 to 16, wherein the transport
drum (11) is configured to move a wrapping sheet (4), which is held, through suction,
on a side surface (14) of the cylindrical body (12).
18. A device (7) to supply wrapping sheets (4) in a packer machine (1), preferably for
smoking articles; the supply device (7) comprises at least one transport drum (11)
according to one of the claims from 1 to 17.