FIELD OF THE INVENTION
[0001] The invention concerns an apparatus and method to make blanks, in particular of cardboard.
BACKGROUND OF THE INVENTION
[0002] Apparatuses to make cardboard blanks, starting from a sheet of cardboard unwound
from a reel, are known. These known apparatuses can be the continuous or intermittent
type: in the first case the sheet is made to move continuously and in the second with
an intermittent step-wise motion.
[0003] The blanks achieved by the apparatus, once they have been folded by means of a folding
apparatus, are intended to be internal wrappers for a packet of smoking articles.
[0004] An internal wrapper, or so-called "collar", is characterized by a predefined length
(L), measured longitudinally and depending on the packet to which the internal wrapper
will be associated. In the state of the art, the length (L) of the internal wrappers
made by the above apparatuses with intermittent functioning assumes only two values,
that is, it can only be equal to 32 mm or 36 mm. It should be noted that such apparatuses
allow to make blanks of a length equal to the predefined length of the internal wrapper.
[0005] Known apparatuses with continuous functioning comprise unwinding rolls, etching rolls
and a cropper, disposed in succession along a direction of feed of the sheet.
[0006] The unwinding rolls are two mutually contra-rotating rolls, having axes of rotation
substantially orthogonal to the direction of feed, which feed the sheet toward the
etching rolls. The latter are also two contra-rotating rolls, having axes of rotation
substantially orthogonal to the direction of feed. Unlike the unwinding rolls, the
etching rolls are not the same as each other, since only one of the rolls comprises
cutter elements, on one of its external surfaces, to make the etchings and/or cuts
on the sheet, intended in particular to form lines of folding and closing fins in
the blanks. The other roll, without cutter elements, guarantees the correct feed of
the sheet, acting as an abutment and contrast to the shearing force which the cutter
elements exert on the sheet while making the etchings and/or cuts.
[0007] The etching roll, provided with the cutter elements is divided into a number of pre-established
angular portions, each of which extends circumferentially for a length equal to L.
During the rotation of the etching rolls, each angular portion etches and/or cuts
a single blank, therefore, during the complete rotation of the etching rolls, a number
of blanks equal to the number of angular portions of the etching roll provided by
the cutter elements, are etched and/or cut successively and continuously.
[0008] Once the etching rolls have etched and/or cut the sheet, the latter moves toward
the cropper, which comprises blades which shear the sheet almost orthogonally to the
direction of feed so as to obtain the blank. In known apparatuses, functioning continuously,
the cropper is generally conformed as a pair of other contra-rotating rolls on which
suitable cutters are provided. It should be noted that the cutter elements with which
the etching roll is provided are disposed and conformed depending on the desired length
(L) of the blank. For this reason, during use, it is necessary to replace the etching
roll every time that, with the above-mentioned known apparatus, blanks of a different
length (L) from the previous ones are made. In other words, when the apparatus makes
32 mm blanks for example, and subsequently for a different production batch, 36 mm
blanks have to be made, or vice versa, an operator has to replace the pair of etching
rolls of the apparatus with another pair of etching rolls provided with the respective
cutter elements suitable to make the blanks of a different production batch. The rolls
have different diameters and the device has different interaxes with different drive
systems. This is due to the fact that as the length L of the blank varies, the amplitude
of each angular portion of the etching roll provided with cutter elements changes,
and therefore so does the diameter of the roll, which determines a change in the distance
between the respective axes of rotation of the etching rolls.
[0009] A further disadvantage of known apparatuses is that they are not very flexible.
[0010] This entails another disadvantage which characterizes known apparatuses which, as
they are subject to long downtimes to allow the replacement of the etching rolls,
are subject to a reduction in productivity.
[0011] Moreover, it must be taken into consideration that at present new types of packets
for smoking articles are spreading rapidly on the market. These new types of packets,
of different shapes and sizes, comprise internal wrappers of different lengths (L),
which lengths are no longer limited only to the two standard lengths of traditional
packets, that is, 32 mm and 36 mm.
[0012] This makes known apparatuses very expensive, because each different length of the
blanks needs a different pair of etching rolls, which considerably increases the cost
of known apparatuses.
[0013] Known apparatuses with intermittent functioning comprise unwinding rolls structurally
similar to those of known apparatuses with continuous functioning as described above,
and downstream of the latter, in succession, an etching device and a cropping device.
The latter are both provided with mobile blades with alternate motion between a lowered
position in which they do not interact with the sheet and a raised position in which
they cut the sheet when it is stationary. These apparatuses, compared to the above
described continuous functioning apparatuses, have the further disadvantage of having
lower productivity and also have the same disadvantages, inasmuch as the etching device
must be replaced each time that a blank of a different length L is to be produced.
Furthermore, in these apparatuses the blades of the cutter elements wear much more
rapidly and therefore have to be replaced more often, thus increasing the costs of
the apparatus and further reducing the productivity due to the machine downtimes for
maintenance.
[0014] One purpose of the present invention is to provide an apparatus which is more flexible
than known apparatuses.
[0015] A further purpose of the present invention is to provide an apparatus which has high
productivity and does not require long and frequent downtimes of the machine to allow
the operator to equip the apparatus for different production.
[0016] A derived purpose of the invention is to keep constant the diameter of the etching
rolls, replacing only the cutter means which will cover different angles in relation
to the different measurements.
[0017] Another purpose of the invention is to provide an apparatus which is both more economical
than known apparatuses and can be controlled and managed even from remote.
SUMMARY OF THE INVENTION
[0018] According to embodiments, an apparatus to make blanks starting from a sheet of material
fed by feed means in a direction of feed is provided. In one embodiment, said apparatus
comprises etching and cutting means suitable to perform etchings and/or longitudinal
cuts on said sheet, parallel to said direction of feed, and cropping means suitable
to shear said sheet so as to separate said blank from it. The etching and cutting
means comprise at least a first roll to which at least a second roll, parallel to
said first roll, is associated. Said at least a first roll has an external surface.
Said at least a first roll is provided with cutter means on said external surface.
Said cutter means comprises one or more cutters made in correspondence with an angular
portion of said first roll. Said one or more cutters have a circumferential length
correlated to a length of said blank.
[0019] According to further embodiments, a method for making blanks starting from a sheet
of material is provided. In one embodiment, the method comprises:
at least a feed step during which said sheet is made to advance, according to an intermittent
step-wise motion, by means of feed means fed step-wise in a direction of feed;
an etching and/or cutting step, during which etchings and/or longitudinal cuts are
made, parallel to said direction of feed, on said sheet by means of etching and cutting
means;
and a separation step, during which said blank is separated from said sheet by means
of cropping means.
[0020] Said etching and/or cutting is performed by at least a first roll associated to a
second roll parallel to said first roll, using cutter means provided on an external
surface of said first roll. Said cutter means comprise one or more cutters made in
correspondence with an angular portion of said first roll. Said one or more cutters
have a circumferential length correlated to a length of said blank.
[0021] According to still further embodiments, a method for making blanks starting from
a sheet of material is provided. In one embodiment, the method comprises: at least
a feed step during which said sheet is made to advance, according to an intermittent
step-wise motion, by means of feed means fed step-wise in a direction of feed;
an etching and/or cutting step, during which etchings and/or longitudinal cuts are
made, parallel to said direction of feed, on said sheet by means of etching and cutting
means comprising at least a first roll provided with cutter means and associated to
a second roll parallel to said first roll;
and a separation step, during which said blank is separated from said sheet by means
of cropping means.
[0022] Said etching and/or cutting step occurs during said feed step and comprises:
a first sub-step in which said first roll and said second roll rotate from an initial
angular position to a final angular position and said cutter means etch and/or cut
said sheet longitudinally in correspondence with a cutting zone, during a specific
tangency sub-step of said first roll with said second roll,
another sub-step in which said first roll and said second roll rotate from said final
angular position to an angular position of disengagement, in which said cutter means
are disengaged from said sheet and do not etch and/or cut said sheet.
[0023] After reaching the disengagement position, the first roll and second roll rotate
to return to the initial angular position and, during the rotation of said first roll
to return to the initial angular position, said feed means are rotated in a direction
inverse to the previous one, in such a manner as to retract said sheet by a quantity
substantially equal to that performed during the rotation of said first roll from
said final angular position to said disengagement position,
[0024] Said feed means and therefore said sheet, are stopped and kept stationary in a pause
position until said first roll reaches said initial angular position.
[0025] These and other features, aspects and advantages of the present disclosure will become
better understood with reference to the following description, the drawings and appended
claims. The drawings, which are incorporated in and constitute a part of this specification,
illustrate embodiments of the present subject matter and, together with the description,
serve to explain the principles of the disclosure.
[0026] The various aspects and features described in the present disclosure can be applied,
individually, wherever possible. These individual aspects, for instance the aspects
and features described in the attached dependent claims, can be made subject of divisional
patent applications.
[0027] It is noted that anything found to be already known during the patenting process
is understood not to be claimed and to be the subject of a disclaimer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention will be better understood and executed with reference to the attached
drawings, which show a non-restrictive example thereof.
- Fig. 1 is a perspective view of an apparatus according to the invention to make blanks;
- Fig.2 is a front view of the apparatus in fig. 1 in which some details have been removed
to better illustrate others;
- Fig. 3 is an enlarged front view of a first version of a roll comprised in the apparatus
of fig. 1 and provided with etching and cutting means;
- Fig. 4 is an enlarged front view of a second version of the roll in fig. 3;
- Fig. 5 is a lateral view of etching rolls comprising the roll in fig. 3;
- Fig. 6 shows blanks made using the apparatus in fig. 1 provided with the roll in fig.
3;
- Fig. 7 shows blanks made using the apparatus in fig.1 provided with the roll in fig.
4;
- Figs. 8 to 11 are front views of the etching means of the apparatus according to the
invention shown in subsequent functioning steps;
- Fig. 12 shows three time-movement Cartesian diagrams associated to different components
of the apparatus in fig. 1.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] Reference will now be made in detail to the various embodiments of the invention,
one or more examples of which are illustrated in the figures. Within the following
description of the drawings, the same reference numbers refer to the same components.
Generally, only the differences with respect to individual embodiments are described.
Each example is provided by way of explanation of the invention and is not meant as
a limitation of the invention. For example, features illustrated or described as part
of one embodiment can be used on or in conjunction with other embodiments to yield
yet a further embodiment. It is intended that the present invention includes such
modifications and variations.
[0030] With reference to figs. 1 and 2, an apparatus 20 to make blanks 30, 130 (visible
in figs. 6 and 7) is shown, starting from a sheet 5 of material, for example a sheet
of cardboard. The sheet 5 is unwound from a reel 11 (fig. 2) and made to move forward
through the apparatus 20 according to a direction of feed A (shown with an arrow in
figs. 1 and 2).
[0031] The apparatus 1 comprises feed means 1, 2 in particular conformed as rolls, so-called
"unwinding rolls" since they contact the sheet 5 and allow it to unwind from the reel
11 and to make it advance in the direction of feed A. The unwinding rolls 1, 2 are
mutually contra-rotating, parallel and tangent with respect to each other, with an
axis of rotation substantially orthogonal to the direction of feed A, and provided
with respective contact surfaces 1a, 2a, intended to contact, during rotation, opposite
sides of the sheet 5 so as to cause a drawing by friction of the latter.
[0032] In the version shown in the drawings, the unwinding rolls comprise four rolls. The
latter comprise two rolls 1 supported in rotation by a drive shaft driven by first
drive means 14, advantageously step-wise rotary motors, and two rolls 2 supported
in rotation by a driven shaft, which is made to rotate by means of a motor transmission
system, for example of the mechanical type with gears, which allows to transmit the
motion of the drive shaft to the driven shaft, and consequently to the two rolls 2.
[0033] In one version, not shown, the unwinding rolls may comprise only two rolls, mutually
contra-rotating around respective parallel axes of rotation, each roll being supported
in rotation by a respective shaft.
[0034] The position of the two rolls 2 is adjustable, also automatically, in an initial
set-up step of the apparatus 20, along a substantially vertical direction, depending
on the thickness of the sheet 5 being worked, thus always guaranteeing contact between
the rolls and the sheet. On the contrary, the position of the two rolls 1 is fixed
in the apparatus 20. Therefore the possibility of adjusting the vertical position
of the two rolls 2 allows the apparatus 20 to work sheets 5 with different thicknesses,
and as a consequence to make blanks of different thicknesses.
[0035] According to a variant, the reciprocal position of the rolls 1 and 2 is adjusted
automatically depending on the thickness of the sheet 5. This automatic positioning
can be obtained with means which move one roll-bearing shaft with respect to the other,
or by providing controlled pressure means which act on one or other of the roll-bearing
shafts.
[0036] Therefore, the strength of contact between the unwinding rolls 1, 2 and the sheet
5 can also be adjusted, acting opportunely on an elastic element, not shown.
[0037] The apparatus 20 also comprises etching and cutting means 3, 4, disposed downstream
of the feed means 1, 2 in the direction of feed A.
[0038] The etching and cutting means 3, 4 are mutually contra-rotating rolls, parallel to
each other, having axes of rotation substantially orthogonal to the direction of feed
A. The etching and cutting means 3, 4 comprise two first rolls 3 (figs. 1, 2 and 5),
equal and coaxial with respect to each other, both having their own determinate external
diameter D1 (figs. 3 and 4). The first two rolls 3 are rotatably supported by the
same drive shaft made to rotate by drive means 17, advantageously step motors. The
second two rolls 4, on the other hand, are rotatably supported by a single driven
shaft, parallel to the drive shaft and made to rotate by means of a motion transmission
system, for example of the mechanical type with gears, which allows to transmit the
motion from the drive shaft to the driven shaft, and consequently to the second rolls
4 themselves.
[0039] In a version not shown, the etching and cutting means may only comprise two rolls,
mutually contra-rotating around respective parallel axes of rotation, each roll being
supported in rotation by a respective shaft.
[0040] The rolls 1, 2, 3 and 4 are mounted on a plate 7, interposed between them and the
drive means 14, 17.
[0041] The drive means 14, 17, and possibly also other drive means 26, described hereafter,
are governed by a control and command unit 36 (fig. 1) which can be associated to
more complex programming and control means 37.
[0042] According to the invention, a sensor mean 38 can be provided suitable both to detect
the presence of the sheet 5 and to possibly read its thickness, in order to control
both the elastic pressure means (not shown) and the possible adjustment means of the
interaxes of the rolls 1, 2, 3 and 4.
[0043] Each first roll 3 comprises a first portion 3a and a second portion 3b. The latter
is conformed as an internal bar, which can be either solid or tubular and has a smaller
diameter d than the external diameter D1 of the roll 3. The portion 3b of each first
roll 3 is rotatably supported by the drive shaft. The first portion 3a is conformed
substantially as a hollow body, substantially cylindrical for example, which at least
partly wraps and surrounds the second portion 3b. In other words, the first portion
3a is substantially coaxial to the second portion 3b and extends longitudinally around
the latter.
[0044] The first portion 3a is removably attached to the second portion 3b by means of suitable
attachment means, of the known type and not shown, and therefore it is made to rotate
by the drive shaft through the second portion 3b.
[0045] The first portion 3a of each first roll 3 is provided with cutter means 9 disposed
on an angular portion 18 of an external surface 19 of the same first roll 3 in order
to make cuts and/or etches on the sheet 5.
[0046] The two first rolls 3 and the two second rolls 4 are disposed so as to define, in
correspondence to a zone of substantial tangency, a cutting zone in which the cutter
means 9 etch and/or cut the sheet 5.
[0047] With reference to figs. 3 and 4 two different forms of embodiment of the first roll
3 are shown.
[0048] In a first form of embodiment of the present invention, shown in fig. 3, the first
portion 3a is removably attached to the second portion 3b and comprises a very wide
angular portion 18, for example 110°, on which the cutter means 9 are made, which
comprise, in correspondence to a central part, a first substantially C-shaped cutter
21. The cutter means 9 also comprise second cutters 22 extending, mutually parallel,
on the external surface 19, for a determinate circumferential length or extension
L1 and interrupted in correspondence to the central part of the angular portion 18
where the first cutter 21 is made. This is better seen in the lateral view 15 in fig.
5, while the function of the first cutter 21 and of the second cutters 22 will be
explained in more detail hereafter.
[0049] In a second form of embodiment of the invention, shown in fig. 4, the first portion
3a is removably attached to the second portion 3b and comprises a very narrow angular
portion 18, for example 45°, on which the cutter means 9 are made which comprise the
first C-shaped cutter 21, and a plurality of third cutters 23, aligned and parallel
with respect to each other, which extend on the external surface 19 for a determinate
circumferential length or extension L2, less than the circumferential length L1 of
the first and second cutters 21 and 22.
[0050] The cutter means 9 (that is, the first cutter 21, the second cutters 22 and the third
cutters 23) project radially by a determinate height H beyond the external diameter
D1 of the external surface 19 so as to be able to interact with the sheet 5 to be
worked without the remaining parts of the external surface 19 interfering thus with
the etching and cutting operations.
[0051] Moreover, it should be noted that the circumferential lengths or extensions L1 and
L2 of the angular portion 18, that is, the part of the surface provided with the cutters
21; 22 or 23 is less than or at most equal to a length L of the blanks 30, 130 (figs.
6 and 7).
[0052] Advantageously, the first portion 3a (figs. 3 and 4) of each first roll 3 can be
easily removed from the corresponding second portion 3b and replaced by another, for
example provided with different cutters 21, 22 and/or 23, having circumferential lengths
equal to or different from L1 or L2, although the external diameter D1 remains the
same, so that it is not necessary to vary, merely because of the replacement, the
interaxis between the first rolls 3 and the second rolls 4.
[0053] The height H of each of the cutters 21, 22 and/or 23 can instead be varied, depending
on the etching and/or cutting operations to be carried out on sheet 5.
[0054] Each second roll 4, of which one surface contacts a side of the sheet 5, acts as
a contrast mean to contrast the action exerted by the first roll 3 on the sheet 5.
[0055] The position of the second roll 4 is adjustable in a substantially vertical direction
approaching or moving away from the first roll 3. The adjustment allows on the one
hand to work sheets 5 having different thicknesses, and on the other, once the thickness
of the sheets and the height of the cutter means 9 are known, to define a desired
amount of penetration of the latter into the sheets 5, so as to make etchings (if
the cutter of the cutter means 9 does not pass through the sheet 5 for the whole of
its thickness), or cuts (if the cutter of the cutter means 9 passes through the sheet
5 for the whole of its thickness).
[0056] Fig. 5 shows a lateral view of the etching means 3, 4 comprising the first roll shown
in fig. 3, by which it is possible to make one blank 30, shown in fig. 6.
[0057] The blank 30 is provided with four lines prepared for folding 31, hereafter defined
as lines of intended folding, in correspondence to which the blank 30 will be folded
to make an internal wrapper. In particular, the lines of intended folding 31 comprise
two external lines of intended folding 31 a and two lines of intended folding 31 b.
[0058] The latter are made with etching means visible in figs. 3 and 5 comprising the first
roll. Each internal line of intended folding 31b comprises a pre-creasing and a closing
fin 32 with which a lid of a packet for smoking articles to which the internal wrapper
is associated will engage. In particular, the closing fin 32 is made using the cutter
21, and the pre-creasing of the internal lines of intended folding 31 b is made using
the other cutters 22. The external lines of intended folding 31a are defined by a
continuous pre-creasing, longitudinal and substantially parallel to that of the internal
lines of intended folding 31 b. The pre-creasings of the external lines of intended
folding 31 a are made, for example, using an alternative version of the feed means
1, 2 of the apparatus 20, not shown. In this version, unlike the feed means 1, 2 shown
in figs. 1, 2 in which the respective contact surfaces 1a, 2a are smooth and mainly
perform a drawing function on the sheet 5, etching elements are made on the contact
surfaces 1a, 2a, for example in correspondence to a median portion thereof. In particular,
the etching elements can be complementary in shape, that is, they are disposed so
that, in correspondence to protrusions of the etching elements, they face recesses
of the other etching elements, and vice-versa. In this way, during use, as well as
moving the sheet 5 by drawing, the feed means 1, 2 also allow to carry out the continuous
pre-creasing of the external lines of intended folding 31a.
[0059] The blank 30, and consequently the internal wrapper that can be obtained from it,
have a length L, measured longitudinally and equal to 80 mm for example. The internal
wrapper wraps the smoking articles on four sides, since the internal wrapper is obtained
by folding the blank 30 along the four lines of intended folding 31.
[0060] With reference to fig. 7, a blank 130 is shown made with etching means 3, 4 comprising
the first roll 3 shown in fig. 4. The blank 130 is provided with two longitudinal
lines of intended folding 131, in correspondence to which the blank 130 will be folded
to make an internal wrapper 133. Each line of intended folding 131 is formed by a
plurality of cuts 135 separated by join points. Each line of intended folding 131,
in a portion without the cuts 135 separated by the join points, comprises a closing
fin 132 with which a lid of a packet for smoking articles to which the internal wrapper
will be associated will engage. The closing fin 132 is made using the cutter 21 and
the cuts 135 are made using the plurality of other cutters 23.
[0061] The blank 130, and consequently the internal wrapper 133 that can be obtained from
it, have a length L, measured longitudinally and equal to 32 mm for example. The internal
wrapper surrounds the smoking articles on three sides.
[0062] The apparatus 20 also comprises a cropper 8, disposed downstream of the etching and
cutting means 3, 4 in the direction of feed A and shown in figs. 1 and 2. The cropper
means 8 comprise blade means 8a mobile according to an alternate motion, and a fixed
support 6 supporting a fixed blade 6a, disposed to cut the blank 30. 130 in cooperation
with the blade means 8a.
[0063] The blade means 8a are driven between a lowered position in which they do not interact
with the blank 30, 130 (shown in fig. 2) and a raised position in which they interact
with the blank 30, 130 in order to separate each blank 30, 130 from the sheet 5 from
which they have been obtained. The blade means 8a are driven by other drive means
26 which drive a connecting rod-handle mechanism 27 to which the blade means 8a are
connected.
[0064] The latter define the profile and the length of the cut, features which it is possible
to modify by replacing the blade means 8a.
[0065] It should be noted that, during their travel (which is fixed and dependent on the
connecting rod-handle mechanism 27), the cropping means 8 make a cut which is substantially
perpendicular to the direction of feed A along the cutting lines 34, 134 (shown in
figs. 6 and 7) which separate two adjacent blanks. The cropping means 8 also comprise
gripping means, of a known type and therefore not shown, such as suckers, which pick
up the blank 30, 130 once it has been cut and separated from the sheet 5 in order
to deliver it to a pick-up device located downstream of the apparatus 20.
[0066] In an initial set-up step of the apparatus 20, it is possible to adjust the position
of the blade 6a with respect to the blade means 8a so as to make a high quality cut.
[0067] In order to make the cut correctly along the cutting lines 34, 134, the cropping
means 8 must be positioned at a distance from the etching and cutting means 3, 4 (in
particular from the tangency zone defined between the first rolls 3 and the second
rolls 4) equal to the length L of the blank 30, 130 being worked, or to integer multiples
of the length L.
[0068] In use, with reference to figs. 8 to 11, four successive configurations are shown
which the etching and/or cutting means 3, 4 assume during the functioning of the apparatus
20.
[0069] The functioning method of the apparatus 20 that will now be described allows to obtain
blanks 30, 130 starting from a sheet 5 of material, in particular cardboard. The method
comprises a feed step during which the sheet 5 is fed forward, with an intermittent
step-wise motion, by the feed means 1, 2 (that is, the unwinding rolls) and an etching
and/or cutting step, simultaneous with the feed step, to obtain on the sheet 5 etchings
31, 131 and/or longitudinal cuts 32, 132, 135 by the etching and/or cutting means
3, 4. Subsequently, the method also comprises a separation step to separate a blank
30, 130 from the sheet 5 from which it is obtained, by means of the cropping means
8.
[0070] The cutter means 3, 4 comprise at least a first roll 3 and at least a second roll
4 which, for the entire range of measurements provided, remain the same, that is,
they keep the same external diameter D1, and only the cutter means 9 (cutters 21,
21 and/or 23) are replaced, which, depending on the sizes of the cut, will cover different
angles in the rolls 3 and/or 4. The first rolls 3 are made to rotate as indicated
by arrow R1, while the second rolls 4 are made to rotate as indicated by arrow R2,
rotation R1 being opposite to the rotation R2.
[0071] In order to make the cuts and/or etchings, the method according to the present invention
provides an assembly step, before the above steps, in order to removably connect the
first portion 3a of the first rolls 3 to the second portion 3b, the first portion
3a being first provided with cutter means 9 to make the etchings 31; 131 and/or the
longitudinal cuts 32; 132, 135.
[0072] In a first sub-step, while the sheet 5 is advancing in the direction of feed A by
a quantity equal to the length L of the blank, the first rolls 3 and the second rolls
4 assume in succession the configurations shown in figs. 8 to 10, that is, they rotate
between an initial angular position B (fig. 8) and a final angular position D (fig.
10). In fig. 8, the first rolls 3 are in the initial angular position B, where an
initial end of their angular portion 18 contacts the lower face of the sheet 5 substantially
in correspondence with the tangency zone between the first rolls 3 and the second
rolls 4. In this way, the cutter means 9, protruding radially outside the external
diameter of the external surface 19, are positioned so as to start to engage with
the sheet 5. In this moment, points of the sheet 5 that will form the cutting lines
34, 134 on which the cropping means 8 will cut, are almost in correspondence with
the tangency zone, in other words, it is important that one edge of the blank 30,
130 is substantially in correspondence with the tangency zone. Subsequently, the first
rolls 3 and the second rolls 4 are rotated in direction R1, first reaching an intermediate
angular position C (shown in fig. 9) and then the final angular position D, shown
in fig. 10. In the intermediate angular position C the cutter means 9 engage with
the sheet 5 to make the cuts 135 on it, the pre-creases that will form the lines of
intended bending 31, 131, and the closing fins 32, 132. In the final angular position
D, a terminal end of the angular portion 18 is almost aligned with the tangency zone,
in correspondence with which the points of the sheet 5 are positioned which will define
the cutting lines 34, 134, that is, the edge points of the blank 30, 130. In this
step, the cutter means 9 have finished making the cuts, the pre-creases and the closing
fins on the sheet 5, even if they are still engaged with the sheet, at least partly
penetrating it.
[0073] After the first sub-step, the method comprises another sub-step in which the first
rolls 3 and the second rolls 4 rotate from the final angular position D to a position
of disengagement E, in which the cutter means 9 no longer engage with the sheet 5
and therefore do not etch and/or cut the sheet 5.
[0074] During the first sub-step and the second sub-step, the unwinding rolls 1, 2 have
to move with the same law of motion as the first rolls 3 and the second rolls 4 to
avoid ripping or lacerating the sheet 5. In this way, however, the unwinding rolls
1, 2 unwind from the reel 11 a greater quantity of material than the length L of the
blank, in particular a quantity L' equal to the quantity unwound during the rotation
of the first rolls 3 and the second rolls 4 from the final angular position D to the
disengagement position E.
[0075] Therefore, after reaching the disengagement position E, while the first and second
rolls 3, 4 rotate as indicated by arrow R1 to return to the initial angular position
B, shown in fig. 8, the unwinding rolls 1, 2 invert their respective rotations (segment
Z visible in the diagram in fig. 12) by a quantity equal to that by which they rotated
during the rotation of the first and second rolls 3, 4 from the final angular position
D to the disengagement position E, so as to retract the sheet 5 by a quantity L'.
[0076] When the unwinding rolls 1, 2 have inverted their rotation as described above, they
are again ready to perform a new work cycle of the apparatus 20 and remain stationary,
in a pause position S (shown in the diagram in fig. 12), until the first and second
rolls 3, 4 again reach the initial angular position B.
[0077] During the pause step of the unwinding rolls 1, 2 in position S, while the first
and second rolls 3, 4 return to the first step B without contacting the sheet 5, the
cropping means 8, in particular the blade means 8a, carry out their outward travel
X from their lowered position to the raised position during which they penetrate through
the sheet 5 in correspondence with the cutting line 34, 134. Afterward, once they
have reached their end-of-travel, the blade means 8a, after a short stop with a duration
T, carry out their return travel Y from their raised position to their lowered position
during which they again pass through the sheet 5. At this point, the work cycle of
the apparatus 20 has been completed, and has obtained a blank 30, 130.
[0078] The apparatus 20 also comprises a control and management unit 36, 37, which allows
to adjust the functioning of the apparatus 20, that is, in particular, to drive, advantageously
step-wise, the drive means 14, 17, 26 so as to coordinate the movement of the unwinding
rolls 1, 2 with that of the first and second rolls 3, 4 and that of the cropping means
8 according to the functioning of the apparatus 20 described above.
[0079] The steps of the work cycle described above, with particular reference to the unwinding
rolls 1, 2, the first and second rolls 3, 4, and the cropping means 8, are also illustrated
by the movement-time Cartesian diagram in fig. 12.
[0080] Thanks to the invention, it is possible to obtain an apparatus 20 to achieve blanks
30, 130, in particular to form an internal casing (or "collar") for a packet for smoking
articles, which is very flexible.
[0081] Indeed, the apparatus 20 can obtain blanks 30, 130 having any desired length L, simply
by replacing the first portion 3a, the so-called "format part", of the first rolls
3 with another first portion suitable for the blank to be made. In particular, the
first portion 3a will be replaced in such a way that the cutter means 9 which it is
provided with extend circumferentially for an arc having a length substantially equal
to length L of the blank to be produced, keeping the external diameter D1 constant.
[0082] This replacement operation can be carried out by an operator quite quickly, since
the second portion 3b of the first rolls 3 does not need to be replaced. For this
reason, the apparatus 20 has a higher productivity than known apparatuses.
[0083] Furthermore, the apparatus 20 does not oblige the operator to entirely replace the
etching and/or cutting means 3, 4 for every different length of the blank, because
it is enough to replace the first portion 3a, without this causing a variation in
the diameter of the first rolls 3. Therefore, it is no longer necessary to replace
the second rolls 4 as well. This entails a considerable reduction in costs, because
it is not necessary to have available a large number of first and second rolls 3,
4, in particular equal to the number of different types of blanks to be made with
the apparatus.
[0084] In a variant of the invention, not shown, the first and second rolls 3, 4 are replaced
by a punch and counter-punch, the punch being provided with the cutter elements that
etch and/or cut the sheet. The punch is mobile between an operating position in which
the cutter elements with which it is provided interact with the sheet, and an inactive
position in which they do not interact with the sheet. The punch acts in the same
way as the first rolls 3 of the apparatus 20 shown, and comprises a first portion,
called "format part", removably attached to a second portion by attachment means of
a known type. The cutter elements are made on the first portion, which faces the sheet
and the counter-punch. As for the apparatus described above, the cutter elements have
a shape and sizes that are a function of the blank to be obtained. In particular,
the cutter elements will extend longitudinally for a length substantially equal to
the length L of the blank. This variant of the apparatus operates with intermittent
functioning. Therefore, when the unwinding rolls rotate, they feed the sheet forward
by a quantity equal to the length L at every step, and afterward, while they are in
the pause step, the punch moves from the inactive position to the operating position,
in which the cutter elements with which it is provided etch and/or cut the sheet.
Furthermore, again while the unwinding rolls are stationary, after etching and/or
cutting the sheet the punch returns to the inactive position, and the cropping means
crop the sheet in correspondence with cutting lines that separate two adjacent blanks,
so as to achieve a blank separate from the sheet from which it was obtained.
[0085] Variants and/or additions to what is described above and/or what is shown in the
drawings are also possible.
[0086] While the foregoing is directed to embodiments of the invention, other and further
embodiments of the invention may be devised without departing from the basic scope
thereof, and the scope thereof is determined by the claims that follow.
1. Apparatus (20) to make blanks (30; 130) starting from a sheet (5) of material fed
by feed means (1, 2) in a direction of feed (A), comprising etching and cutting means
(3, 4) suitable to perform etchings (31; 131) and/or longitudinal cuts (32; 132, 135)
on said sheet (5), parallel to said direction of feed (A), and cropping means (8)
suitable to shear said sheet (5) so as to separate said blank (30; 130) from it, characterized in that said etching and cutting means (3, 4) comprise at least a first roll (3) to which
at least a second roll (4), parallel to said first roll (3), is associated, said at
least a first roll (3) having an external surface (19), said at least a first roll
(3) being provided with cutter means (9) on said external surface (19), said cutter
means (9) comprising one or more cutters (21, 22, 23) made in correspondence with
an angular portion (18) of said first roll (3), said one or more cutters (21, 22,
23) having a circumferential length (L1, L2) correlated to a length (L) of said blank
(30, 130).
2. Apparatus as in claim 1, characterized in that the circumferential lengths (L1, L2) of the angular portion (18) provided with said
one or more cutters (21, 22, 23) is less than or at most equal to the length (L) of
said blank (30, 130).
3. Apparatus as in claim 1 or 2, characterized in that the angular portion (18) on which the cutter means (9) are made is from 45° to 110°.
4. Apparatus as in claim 1, 2 or 3, characterized in that the angular portion (18) on which the cutter means (9) is made is 110°.
5. Apparatus as in claim 4, characterized in that the cutter means (9) comprise, in correspondence to a central part, a first C-shaped
cutter (21), second cutters (22) extending, mutually parallel, on the external surface
(19), for a determinate circumferential length (L1) and interrupted in correspondence
to the central part of the angular portion (18) where the first C-shaped cutter (21)
is made.
6. Apparatus as in claim 1, 2 or 3, characterized in that the angular portion (18) on which the cutter means (9) is made is 45°.
7. Apparatus as in claim 6, characterized in that the cutter means (9) comprise a first C-shaped cutter (21), and a plurality of third
cutters (23), aligned and parallel with respect to each other, which extend on the
external surface (19) for a determinate circumferential length (L2), less than the
circumferential length (L1) of the first and second cutters (21, 22).
8. Apparatus as in any claims hereinbefore, characterized in that said one or more cutters (21, 22, 23) project radially by a determinate height (H)
beyond an external diameter (D1) of the external surface (19) of said first roll (3),
so as to be able to interact with the sheet (5) to be worked without the remaining
parts of the external surface (19) interfering thus with the etching and cutting operations.
9. Apparatus as in claim 8, characterized in that said external diameter (D1) is pre-determined and constant.
10. Apparatus as in any claims hereinbefore, characterized in that the circumferential length (L1, L2) of said cutter means (9) is variable depending
on the etching and/or cutting operations to be carried out on said sheet (5).
11. Apparatus as in any claim hereinbefore, characterized in that said feed means (1, 2) include at least two opposite rolls (1, 2) between which said
sheet (5) is suitable to advance in said direction of feed (A).
12. Apparatus as in any claim hereinbefore, characterized in that said feed means (1, 2) comprise pre-creasing etching means (31a) defining external
lines of preparation for bending in said blank (30).
13. Apparatus as in any claim hereinbefore, characterized in that said cropping means (8) are positioned at a distance from a cutting zone, defined
by a tangency zone in which said first roll (3) is substantially tangent to said second
roll (4), at least for an extension equal to the length (L) of said blank (30; 130),
or to integer multiples of said length (L).
14. Apparatus as in any claim hereinbefore, characterized in that said cropping means (8) comprise a support (6) equipped with at least first fixed
blade means (6a).
15. Apparatus as in claim 14, characterized in that other blade means (8a) are present, cooperating with said first blade means (6a)
to shear said sheet (5) so as to achieve said blank (30; 130) and to separate it from
said sheet (5), and in that said other blade means (8a) present a raised operating position, and a lowered non-operating
position.
16. Apparatus as in any claim hereinbefore, characterized in that at least said feed means (1, 2) are driven by their own drive member (14) governed
by a control and command unit (36) which controls it step-wise.
17. Apparatus as in any claim hereinbefore, characterized in that at least said feed means (1, 2) include automatic interaxis adjustment means, according
to the sheet (5) to be fed.
18. Apparatus as in any claim hereinbefore, characterized in that said cutter means (9) are replaceable.
19. Method for making blanks (30; 130) starting from a sheet (5) of material, comprising
at least a feed step during which said sheet (5) is made to advance, according to
an intermittent step-wise motion, by means of feed means (1, 2) fed step-wise in a
direction of feed (A); an etching and/or cutting step, during which etchings (31;
131) and/or longitudinal cuts (32; 132, 135) are made, parallel to said direction
of feed (A), on said sheet (5) by means of etching and cutting means (3, 4), and a
separation step, during which said blank (30; 130) is separated from said sheet (5)
by means of cropping means (8), characterized in that said etching and/or cutting is performed by at least a first roll (3) associated
to a second roll (4) parallel to said first roll (3), using cutter means (9) provided
on an external surface (19) of said first roll (3), said cutter means (9) comprising
one or more cutters (21, 22, 23) made in correspondence with an angular portion (18)
of said first roll (3), said one or more cutters (21, 22, 23) having a circumferential
length (L1, L2) correlated to a length (L) of said blank (30; 130).
20. Method as in claim 19, characterized in that said etching and/or cutting step occurs during said feed step and comprises a first
sub-step in which said first roll (3) and said second roll (4) rotate from an initial
angular position (B) to a final angular position (D) and said cutter means (9) etch
and/or cut said sheet (5) longitudinally in correspondence with a cutting zone, during
a specific tangency sub-step of said first roll (3) with said second roll (4), in that said etching and/or cutting step comprises another sub-step in which said first roll
(3) and said second roll (4) rotate from said final angular position (D) to an angular
position of disengagement (E), in which said cutter means (9) are disengaged from
said sheet (5) and do not etch and/or cut said sheet (5) and in that during said first sub-step and during said other sub-step, said first roll (3), said
second roll (4) and said feed means (1, 2) are rotated according to the same law of
motion, controlled by control and command means (36).
21. Method as in claim 20, characterized in that after reaching the disengagement position (E), the first roll (3) and second roll
(4) rotate to return to the initial angular position (B), and in that during the rotation of said first roll (3) to return to the initial angular position
(B), said feed means (1, 2) are rotated in a direction (Z) inverse to the previous
one, in such a manner as to retract said sheet (5) by a quantity (L') substantially
equal to that performed during the rotation of said first roll (3) from said final
angular position (D) to said disengagement position (E) and in that said feed means (1, 2) and therefore said sheet (5), are stopped and kept stationary
in a pause position (S) until said first roll (3) reaches said initial angular position
(B).
22. Method for making blanks (30; 130) starting from a sheet (5) of material, comprising
at least a feed step during which said sheet (5) is made to advance, according to
an intermittent step-wise motion, by means of feed means (1, 2) fed step-wise in a
direction of feed (A); an etching and/or cutting step, during which etchings (31;
131) and/or longitudinal cuts (32; 132, 135) are made, parallel to said direction
of feed (A), on said sheet (5) by means of etching and cutting means (3, 4) comprising
at least a first roll (3) provided with cutter means (9) and associated to a second
roll (4) parallel to said first roll (3), and a separation step, during which said
blank (30; 130) is separated from said sheet (5) by means of cropping means (8),
said method being
characterized in that said etching and/or cutting step occurs during said feed step and comprises:
a first sub-step in which said first roll (3) and said second roll (4) rotate from
an initial angular position (B) to a final angular position (D) and said cutter means
(9) etch and/or cut said sheet (5) longitudinally in correspondence with a cutting
zone, during a specific tangency sub-step of said first roll (3) with said second
roll (4),
another sub-step in which said first roll (3) and said second roll (4) rotate from
said final angular position (D) to an angular position of disengagement (E), in which
said cutter means (9) are disengaged from said sheet (5) and do not etch and/or cut
said sheet (5),
in that after reaching the disengagement position (E), the first roll (3) and second roll
(4) rotate to return to the initial angular position (B),
in that during the rotation of said first roll (3) to return to the initial angular position
(B), said feed means (1, 2) are rotated in a direction (Z) inverse to the previous
one, in such a manner as to retract said sheet (5) by a quantity (L') substantially
equal to that performed during the rotation of said first roll (3) from said final
angular position (D) to said disengagement position (E),
and in that said feed means (1, 2) and therefore said sheet (5), are stopped and kept stationary
in a pause position (S) until said first roll (3) reaches said initial angular position
(B).
23. Method as in claim 22, characterized in that during said first sub-step and during said other sub-step, said first roll (3), said
second roll (4) and said feed means (1, 2) are rotated according to the same law of
motion, controlled by control and command means (36).
24. Method as in claim 22 or 23, characterized in that said at least one first roll (3) has an external surface (19), said cutter means
(9) being provided on said external surface (19) and comprising one or more cutters
(21, 22, 23) made in correspondence with an angular portion (18) of said first roll
(3), said one or more cutters (21, 22, 23) having a circumferential length (L1, L2)
correlated to a length (L) of said blank (30, 130).