U.S. patent application number 14/464883 was filed with the patent office on 2015-02-26 for automatic packaging machine for continuously packaging products each wrapped in a single envelope and method for continuously packaging products each wrapped in a single envelope.
This patent application is currently assigned to SITMA MACHINERY S.p.A.. The applicant listed for this patent is SITMA MACHINERY S.p.A.. Invention is credited to Aris BALLESTRAZZI.
Application Number | 20150052851 14/464883 |
Document ID | / |
Family ID | 49519032 |
Filed Date | 2015-02-26 |
United States Patent
Application |
20150052851 |
Kind Code |
A1 |
BALLESTRAZZI; Aris |
February 26, 2015 |
AUTOMATIC PACKAGING MACHINE FOR CONTINUOUSLY PACKAGING PRODUCTS
EACH WRAPPED IN A SINGLE ENVELOPE AND METHOD FOR CONTINUOUSLY
PACKAGING PRODUCTS EACH WRAPPED IN A SINGLE ENVELOPE
Abstract
Automatic packaging machine (10) for continuously packaging
products (P) each wrapped in a single envelope (B), comprising a
conveyor (12) that defines a conveying plane (PT) for conveying a
continuous sheet (F) of packaging material, in particular paper,
along a conveying direction (DT), said conveying plane (PT)
comprises an entrance end (12a) of the continuous sheet (F) and an
exit end of a plurality of envelopes, each containing a product
(P), in which the entrance end (12a) is associable with a feeding
unit of a plurality of products (P) in succession one after the
other and at a distance one from another on the continuous sheet
(F) fed on the conveying plane (PT), a feeding unit (18) of the
continuous sheet (F) on the conveying plane (PT) and that feeds the
continuous sheet (F) along a feeding plane (PA) that extends below
the conveying plane (PT), is orthogonal or substantially orthogonal
to the conveying direction (DT) and is defined at the entrance end
(12a) of the conveying plane (PT), wherein the continuous sheet (F)
is fed along the feeding plane (PA) according to a feeding
direction (DA) orthogonal or substantially orthogonal to the
conveying plane (PT) and is deviated by a right angle or
substantially a right angle in the passage from the feeding plane
(PA) to the conveying plane (PT), a creasing unit (26) of the
continuous sheet (F) to define a pair of longitudinal creases (C1,
C2) in it for respectively folding a first longitudinal leaf (F1)
that defines the back (B2) of the envelopes (B) and a second
longitudinal leaf (F2) that defines the closing flap (B3) of the
envelopes (B), in which the first longitudinal leaf (F1) and the
second longitudinal leaf (F2) define a longitudinal central portion
(F3) of the continuous sheet that defines the front (B1) of each
envelope (B) and on which the products (P) are fed arranged in
succession one after another and at a distance one from another, in
which the packaging machine (10) comprises at least one die-cutting
unit (27) for die-cutting at least one of the first longitudinal
leaf (F1), or in any case the longitudinal portion of the
continuous sheet that defines it, and the second longitudinal leaf
(F2), or in any case the longitudinal portion of the continuous
sheet that defines it, to respectively die-cut in it the back (B2)
and/or the profile of the back (B2) and the closing flap (B3)
and/or the profile of the closing flap (B2) of each envelope (B),
in which the die-cutting unit (27) is arranged between the entrance
end and the exit end of the conveying plane (PT) to act on the
continuous sheet (F) fed on the conveying plane (PT).
Inventors: |
BALLESTRAZZI; Aris;
(Savignano Sul Panaro, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SITMA MACHINERY S.p.A. |
Spilamberto |
|
IT |
|
|
Assignee: |
SITMA MACHINERY S.p.A.
Spilamberto
IT
|
Family ID: |
49519032 |
Appl. No.: |
14/464883 |
Filed: |
August 21, 2014 |
Current U.S.
Class: |
53/410 ;
53/128.1; 53/206; 53/460 |
Current CPC
Class: |
B65B 9/067 20130101;
B65B 49/00 20130101; B65H 2801/81 20130101; B43M 5/042 20130101;
B65B 61/12 20130101 |
Class at
Publication: |
53/410 ; 53/206;
53/128.1; 53/460 |
International
Class: |
B65B 9/067 20060101
B65B009/067; B65B 61/02 20060101 B65B061/02; B65B 11/48 20060101
B65B011/48; B65B 35/10 20060101 B65B035/10; B65B 49/00 20060101
B65B049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2013 |
IT |
MI2013A 001404 |
Claims
1: An automatic packaging machine for continuously packaging
products each wrapped in a single envelope, comprising: a conveyor
that defines a conveying plane for conveying a continuous sheet of
packaging material along a conveying direction, said conveying
plane comprising an entrance end of said continuous sheet and an
exit end of a plurality of envelopes, each containing one of said
products, wherein said entrance end of said conveyor can be
associated with a feeding unit of a plurality of products in
succession one after another and at a distance one from another on
the continuous sheet fed on said conveying plane, a feeding unit
for feeding said continuous sheet on said conveying plane and that
feeds said continuous sheet along a feeding plane that extends
below said conveying plane, is orthogonal or substantially
orthogonal to said conveying direction and is defined at said
entrance end of said conveying plane, wherein said continuous sheet
is fed along said feeding plane according to a feeding direction
orthogonal or substantially orthogonal to said conveying plane and
is deviated by a right angle or substantially a right angle in the
passage from said feeding plane to said conveying plane, a creasing
unit of said continuous sheet to define a pair of longitudinal
creases in it for respectively folding a first longitudinal leaf
that defines the back of said envelopes and a second longitudinal
leaf that defines the closing flap of said envelopes, wherein said
first longitudinal leaf and said second longitudinal leaf define a
longitudinal central portion of said continuous sheet that defines
the front of each of said envelopes and on which said products are
fed arranged in succession one after another and at a distance one
from another, wherein said packaging machine comprises: at least
one die-cutting unit for die-cutting at least one of said first
longitudinal leaf, or in any case the longitudinal portion of said
continuous sheet that defines said first longitudinal leaf, and
said second longitudinal leaf, or in any case the longitudinal
portion of said continuous sheet that defines said second
longitudinal leaf, to die-cut in it the back and/or the profile of
the back and the closing flap and/or the profile of the closing
flap of each of said envelopes, respectively, wherein said
die-cutting unit is arranged between said entrance end and said
exit end of said conveying plane to act on said continuous sheet
fed on said conveying plane.
2: A packaging machine according to claim 1, wherein said at least
one die-cutting unit is designed to die-cut said second
longitudinal leaf (F2), or in any case the longitudinal portion of
said continuous sheet that defines said second longitudinal leaf,
to die-cut in it said closing flap of each of said envelopes and/or
define in it the profile of said closing flap of each of said
envelopes.
3: The packaging machine according to claim 1, wherein said
creasing unit is arranged at said entrance end of said conveying
plane and in that said at least one die-cutting unit is arranged
downstream, with respect to the sense of forward motion of said
continuous sheet along said conveying direction, of said creasing
unit to act on said continuous sheet fed on said conveying
plane.
4: The packaging machine according to claim 3, wherein it
comprises, downstream, with respect to the sense of forward motion
of said continuous sheet along said conveying direction, of said
creasing unit and also in a different succession, at least the
following operative units: a first folding unit for folding said
first longitudinal leaf on said longitudinal central portion of
said continuous sheet so as to at least partially cover said
products, forming the back of said envelopes and obtaining a
continuous wrapping, or for folding the portion of said first
longitudinal leaf of each longitudinal section of said continuous
sheet that defines a respective envelope on the respective portion
of said longitudinal central portion so as to at least partially
cover the respective product forming the back of the respective
envelope, a pressing unit for exerting a pressure on said first
longitudinal leaf folded on said longitudinal central portion or in
any case on the portion of said first longitudinal leaf of each
longitudinal section of said continuous sheet that defines a
respective envelope folded on the respective portion of said
longitudinal central portion at at least one transversal strip of
adhesive or glue present or in any case applied on said continuous
sheet or on each longitudinal section of said continuous sheet that
defines a respective said envelope at at least one segment of at
least one of the two transversal sides of each said longitudinal
section that defines a corresponding envelope, a transversal
cutting unit for the transversal cutting of said continuous
wrapping or in any case of said continuous sheet between two
successive products so as to obtain a plurality of longitudinal
sections of said continuous wrapping or of continuous sheet that
are separate from each other and each defining a respective
envelope.
5: The packaging machine according to claim 4, wherein said at
least one die-cutting unit is a separate and distinct unit from
each of said operative units and arranged between said entrance end
and said exit end of said conveying plane.
6: The packaging machine according to claim 5, wherein said at
least one die-cutting unit is arranged upstream, with respect to
the sense of forward motion of said continuous sheet along said
conveying direction, with respect to said cutting unit.
7: The packaging machine according to claim 1, wherein said at
least one die-cutting unit comprises a drum-type or drum sector or
segment-type die-cutter that is rotatably supported above said
conveying plane with its own longitudinal axis parallel to said
conveying plane and transversal to said conveying direction and
that is associable with motor means for making it rotate and a
contrast element of said die-cutter arranged with its contrast
surface substantially at the level of said conveying plane.
8: The packaging machine according to claim 4, wherein said at
least one die-cutting unit is integrated or in any case
incorporated in said pressing unit or in said transversal cutting
unit.
9: The packaging machine according to claim 8, wherein said at
least one die-cutting unit is integrated or in any case
incorporated in said pressing unit and in that said pressing unit
comprises a shaft that is rotatably supported above said conveying
plane with its longitudinal axis parallel to said conveying plane
and transversal to said conveying direction and that is associable
with motor means for making it rotate about its own axis and a
pressing element that is mounted on said shaft, wherein said at
least one die-cutting unit comprises a drum-type or drum sector or
segment-type die-cutter that is mounted on said shaft coaxial to it
beside an end of said pressing element.
10: The packaging machine according to claim 4, wherein it
comprises a second folding unit arranged downstream, with respect
to the sense of forward motion of said continuous sheet along said
conveying direction, of said first folding unit and of said at
least one die-cutting unit for folding said second longitudinal
leaf on said first longitudinal leaf that has already been folded
or for folding the portion of said second longitudinal leaf of each
longitudinal section of said continuous sheet that defines a
respective envelope on the corresponding portion of said first
longitudinal leaf that has already been folded.
11: The packaging machine according to claim 4, wherein it
comprises a glue application unit arranged downstream, with respect
to the sense of forward motion of said continuous sheet along said
conveying direction, of said at least one die-cutting unit for
applying at least one strip of glue parallel to said conveying
direction on said second longitudinal leaf or on the portion of
said second longitudinal leaf of each longitudinal section of said
continuous sheet that defines a respective envelope.
12: The packaging machine according to claim 3, wherein said at
least one die-cutting unit is designed to die-cut, in said second
longitudinal leaf or in any case in the longitudinal portion of
said continuous sheet that defines said second longitudinal leaf, a
plurality of transversal notches, each of which comprises a first
flank and a second flank that are angled to one another and
convergent towards the respective longitudinal folding crease and
that define the profile at an end of the closing flap of two
consecutive envelopes.
13: The packaging machine according to claim 12, wherein said first
flank and said second flank of each of said transversal notches
intersect one another in a "V" with the vertex of the "V"
substantially at said longitudinal folding crease of said second
longitudinal leaf.
14: The packaging machine according to claim 1, wherein said at
least one die-cutting unit is designed to die-cut, in said first
longitudinal leaf or in any case in the longitudinal portion of
said continuous sheet that defines said first longitudinal leaf
and/or in said second longitudinal leaf or in any case in the
longitudinal portion of said continuous sheet that defines said
second longitudinal leaf, a plurality of perforations, incisions,
toothings or similar, in particular for tamper-proofing.
15: The packaging machine according to claim 1, wherein it
comprises at least one auxiliary die-cutting unit that is
integrated in said feeding unit and is designed to die-cut at least
one of said first longitudinal leaf, or in any case the
longitudinal portion of said continuous sheet that defines said
first longitudinal leaf, and said longitudinal central portion of
said continuous sheet, or in any case the longitudinal portion of
said continuous sheet that defines said longitudinal central
portion, to respectively define in it the profile of the edge that
defines the back of each of said envelopes and a window at the
front of each of said envelopes and/or perforations, holes,
incisions, toothings or similar, in particular for
tamper-proofing.
16: A method for continuously packaging products, each wrapped in a
single envelope, comprising the steps of: feeding a continuous
sheet of packaging material, in particular paper, on a conveying
plane, wherein said conveying plane is movable to transport said
continuous sheet along a conveying direction in a sense of forward
motion between an entrance end of said continuous sheet and an exit
end of a plurality of envelopes each containing a respective
product, wherein said feeding comprises making said continuous
sheet advance along a feeding plane that extends below said
conveying plane, is orthogonal or substantially orthogonal to said
conveying direction and is defined at said entrance end of said
conveying plane, wherein said continuous sheet is fed along said
feeding plane according to a feeding direction orthogonal or
substantially orthogonal to said conveying plane and is deviated by
a right angle or substantially a right angle in the passage from
said feeding plane to said conveying plane; feeding on said
continuous sheet moving forward along said conveying direction a
plurality of products arranged in succession one after another and
at a distance from one another; defining in said continuous sheet
being fed on said conveying plane or moving forward along said
conveying direction a pair of longitudinal creases for folding a
respective longitudinal leaf, a first longitudinal leaf that
defines the back of said envelopes and a second longitudinal leaf
that defines the closing flap of said envelopes, respectively,
wherein said first longitudinal leaf and said second longitudinal
leaf define a longitudinal central portion of said continuous sheet
that defines the front of said envelopes and on which said products
are fed arranged in succession one after another and at a distance
from one another; wherein after said feeding of said continuous
sheet on said conveying plane and before the exit of said envelopes
from said exit end of said conveying plane there is at least one
step of die-cutting at least one of said first longitudinal leaf,
or in any case the longitudinal portion of said continuous sheet
that defines said first longitudinal leaf, and said second
longitudinal leaf, or in any case the longitudinal portion of said
continuous sheet that defines said second longitudinal leaf, to
respectively die-cut in it the back and/or the profile of the back
and the closing flap and/or the profile of the closing flap of each
of said envelopes.
17: The packaging method according to claim 16, wherein said at
least one die-cutting step is provided for die-cutting said second
longitudinal leaf, or in any case the longitudinal portion of said
continuous sheet that defines said second longitudinal leaf, to
die-cut in it the closing flap and/or the profile of the closing
flap of each of said envelopes.
18: The packaging method according to claim 16, wherein said at
least one die-cutting step follows said step of defining in said
continuous sheet said pair of longitudinal folding creases.
19: The packaging method according to claim 18, also comprising,
after said step of defining in said continuous sheet said pair of
longitudinal folding creases, also in a different succession to one
another, at least the operative steps of: folding said first
longitudinal leaf on said longitudinal central portion of said
continuous sheet so as to at least partially cover said products,
forming the back of said envelopes and obtaining a continuous
wrapping, or folding the portion of said first longitudinal leaf of
each longitudinal section of said continuous sheet that defines a
respective envelope on the respective portion of said longitudinal
central portion so as to at least partially cover the respective
product forming the back of the respective envelope, pressing said
first longitudinal leaf folded on said longitudinal central portion
or the portion of said first longitudinal leaf of each longitudinal
section of said continuous sheet that defines a respective envelope
folded on the respective portion of said longitudinal central
portion, exerting a pressure at at least one transversal strip of
adhesive or glue present or in any case applied on said continuous
sheet or on each longitudinal section of said continuous sheet that
defines a respective said envelope at at least one segment of at
least one of the two transversal sides of each said longitudinal
section that defines a corresponding envelope, transversally
cutting said continuous wrapping or said continuous sheet between
two successive products so as to obtain a plurality of longitudinal
sections of said continuous wrapping or of said continuous sheet
that are separate from one another and each defining a respective
envelope.
20: The packaging method according to claim 19, wherein said at
least one die-cutting step takes place at least in part
simultaneously with said pressing step or with said transversal
cutting step.
21: The packaging method according to claim 19, wherein said at
least one die-cutting step is separate and distinct from each of
said operative steps and preferably takes place before said
pressing step and/or before said transversal cutting step.
22: The packaging method according to claim 19, comprising, after
said at least one die-cutting step and after said step of folding
said first longitudinal leaf or the portion of said first
longitudinal leaf of each longitudinal section of said continuous
sheet that defines a respective envelope, a step of folding said
second longitudinal leaf on said first longitudinal leaf that has
already been folded or the portion of said second longitudinal leaf
of each longitudinal section of said continuous sheet that defines
a respective envelope on the corresponding portion of said first
longitudinal leaf that has already been folded.
23: A method according to claim 19, also comprising, after said at
least one die-cutting step, a step of applying, on said second
longitudinal leaf or on the portion of said second longitudinal
leaf of each longitudinal section of said continuous sheet that
defines a respective envelope, a strip of glue parallel to said
conveying direction.
24: The method according to claim 18, wherein said die-cutting step
consists of die-cutting, in said second longitudinal leaf or in any
case in the longitudinal portion of said continuous sheet that
defines said second longitudinal leaf, a plurality of transversal
notches, each of which comprises a first flank and a second flank
that are angled to one another and convergent towards the
respective longitudinal folding crease and that define the profile
of an end of the closing flap of two consecutive envelopes.
25: The method according to claim 24, wherein said first flank and
said second flank of each of said transversal notches intersect in
a "V" with the vertex of the "V" substantially at the longitudinal
folding crease of said second longitudinal leaf.
26: The method according to claim 16, wherein said die-cutting step
consists of die-cutting, in said first longitudinal leaf or in any
case in the longitudinal portion of said continuous sheet that
defines said first longitudinal leaf and/or in said second
longitudinal leaf or in any case in the longitudinal portion of
said continuous sheet that defines said second longitudinal leaf, a
plurality of perforations, incisions, toothings or similar, in
particular for tamper-proofing.
27: The method according to claim 16, also comprising at least one
further die-cutting step carried out during said feeding step to
die-cut at least one of said first longitudinal leaf, or in any
case the longitudinal portion of said continuous sheet that defines
said first longitudinal leaf, and said longitudinal central portion
of said continuous sheet, or in any case the longitudinal portion
of said continuous sheet that defines said longitudinal central
portion, to respectively define in it the profile of the edge that
defines the back of each of said envelopes and a window at the
front of each of said envelopes and/or perforations, holes,
incisions, toothings or similar, in particular for tamper-proofing.
Description
[0001] The present invention refers to an automatic packaging
machine for continuously packaging products each wrapped in a
single envelope.
[0002] The present invention also refers to a method for
continuously packaging products each wrapped in a single
envelope.
[0003] There are known automatic packaging machines that operate
continuously and that are of the type suitable for producing
packages consisting of envelopes, each containing inside it a
product of the type, in particular, of a printed product consisting
of a sheet, a folded sheet, a fascicle of sheets, an insert or
similar.
[0004] These automatic packaging machines are suitable for
producing packages the envelope of which consists of a single front
on which two flaps are folded, the flaps being at least partially
overlapped, wherein one flap defines the actual back of the
envelope and the other defines a closing flap of the envelope
itself--known in the jargon as closing "tab"--and wherein,
moreover, the envelope can be closed at at least one of its two
opposite sides.
[0005] In these packaging machines the products, which are made to
advance one after the other and at distance one from another, are
fed on a continuous sheet of paper that is unwound continuously
from a reel, is rested on a sliding plane (in practice consisting
of a conveyor belt) and is conveyed by it along a conveying
direction.
[0006] The opposite longitudinal leaves of the continuous sheet of
paper, on which the products have been fed, are then folded one
upon the other to form the back and the closing flap (closing
"tab") of each envelope and thus obtain a tubular, flat and
continuous wrapping containing inside it a plurality of products
that are arranged in succession one after the other and spaced
apart from one another.
[0007] The tubular wrapping thus obtained is then cut between two
successive products so as to obtain single envelopes, each of which
containing a respective product, or pressed at glue strips, which
are previously applied onto the continuous sheet of paper at one or
both of the transversal sides of each longitudinal portion thereof
that defines a corresponding envelope, and then cut between two
successive products so as to obtain single envelopes, each of which
is closed at one or both sides and contains a respective
product.
[0008] In these automatic packaging machines of the known type, the
continuous sheet of paper is fed as the entrance of the sliding
plane simultaneously to the feeding on it of the products to be
packaged.
[0009] For such a purpose, the continuous sheet of paper is unwound
from a reel and fed, by means of a feeding unit with which the
packaging machine itself is equipped, along a feeding plane
substantially orthogonal to the sliding plane and arranged close to
the entrance end of the latter.
[0010] In practice, considering that the sliding plane lies
horizontally, the continuous sheet of paper is fed from the bottom
upwards along a substantially vertical plane close to the entrance
end of the sliding plane itself.
[0011] While passing from the feeding plane (substantially
vertical) to the sliding plane (substantially horizontal), the
continuous sheet of paper undergoes a deviation of about
90.degree..
[0012] During such passage the continuous sheet of paper is creased
longitudinally so as to define the folding lines of two
longitudinal leaves thereof, which are then folded one upon another
on the products already fed onto the sheet itself.
[0013] For such a purpose, known packaging machines are equipped
with a creasing unit that is arranged close to the entrance end of
the sliding plane and that comprises, for each side of the sliding
plane, a block provided with an edge that faces the continuous
sheet of paper that rises along the feeding plane and that is
parallel to the feeding direction of the sheet itself to impress on
the latter a respective longitudinal creasing that defines a
respective longitudinal leaf.
[0014] At each side of the sliding plane a folding bar for folding
the corresponding longitudinal leaf is then arranged.
[0015] Such folding bars are supported at one end by a bridge-type
frame fixed astride of the sliding plane with the interposition of
adjusting means for adjusting the spatial position thereof.
[0016] As the format of the envelope varies, the width of the front
and/or the width of the longitudinal leaves that form the two flaps
(back and closing flap or "tab") of each envelope and/or the degree
of overlapping of the two flaps, as well as the length of the
single envelope, vary.
[0017] The longitudinal edges of the continuous sheet of paper can
be rectilinear and continuous, so that the two flaps that
respectively define the back and the closing flap (closing "tab")
of each envelope are rectangle shaped.
[0018] Alternatively, the longitudinal edge of the continuous sheet
of paper that defines the longitudinal leaf that forms the closing
flaps (closing "tabs") of the envelopes is interrupted by a
plurality of transversal notches, each of which forms the profile
of one of the two opposite ends of the closing flap (closing "tab")
of two successive envelopes. This allows to obtain envelopes that
have an appearance similar to that of standard pre-formed
envelopes.
[0019] According to the prior art, such a longitudinal edge of the
continuous sheet of paper is profiled by die-cutting by means of a
die-cutter that is separate and "off-line" with respect to the
packaging machine or by means of a die-cutter that is separate and
"in line" with the packaging machine.
[0020] In the first case, the continuous sheet of paper is unwound
from the reel to be fed at the entrance of a die-cutter that
performs the profile-forming of the longitudinal edge thereof that
will then define the closing flaps (closing "tabs") of the
envelopes. The die-cutter is separate and remote with respect to
the packaging machine, so that the continuous sheet of paper
exiting from the die-cutter is rewound in a reel which, when
needed, is then used to feed a packaging machine. In this case,
therefore, the continuous sheet of paper that is unwound from the
reel that feeds the packaging machine is already die-cut.
[0021] In the second case, on the other hand, the die-cutter is
arranged "in line" with the packaging machine. In particular, the
die-cutter is arranged between the unreeling unit and the feeding
unit of the packaging machine with the possible interposition of
storage units (so-called "storage unit" or "buffers") that can be
necessary to compensate for the different operating speeds of the
die-cutter and of the packaging machine.
[0022] In both cases, however, the continuous sheet of paper is fed
at the entrance of the packaging machine and, in particular, at the
entrance of the sliding plane already die-cut and profiled.
[0023] FIG. 14A schematically shows a reel 200 of a continuous
sheet of paper that is pre-die-cut, according to the prior art,
"off-line". FIG. 14B schematically shows a portion of a continuous
sheet 201 of paper die-cut, according to the prior art, by a
die-cutter that is separate from the packaging machine and
"off-line" or "in line" with the latter. FIG. 14C shows a detail of
the sheet 201 of FIG. 14B on an enlarged scale.
[0024] FIGS. 14B and 14C represent, with a broken line: a first
longitudinal crease 202, which defines a first longitudinal leaf
201a intended to form the back B2 of each envelope, a second
longitudinal crease 203, which defines a second longitudinal leaf
201b intended to form the closing flap or "tab" B3 of each
envelope, and the separation lines 205 that define two successive
longitudinal portions of the sheet 201 each intended to define a
respective envelope comprising a front B1, a back B2 and a closing
flap or "tab" B3. It should be specified that the first crease 202
and the second crease 203 are defined in the sheet 201 during its
processing carried out by the packaging machine, whereas the
separation line 205 is that at which it is foreseen for the
transversal cut to theoretically take place.
[0025] The outer edge of the second longitudinal leaf 201b is
die-cut and has a plurality of transversal notches 204.
[0026] Each notch 204 has a first flank 204a and a second flank
204b angled to one another and converging towards the second
longitudinal crease 203. The first flank 204a and the second flank
204b of each notch 204 each define a bevelled end of a closing flap
of two successive envelopes.
[0027] It should be noted, in particular, that the first flank 204a
and the second flank 204b of each notch 204 are joined together by
a rectilinear portion 204c of length l that is parallel to the
second longitudinal crease 203 and that is a non-zero distance d
away from the latter.
[0028] Generally, the length l and the distance d are of the order
of a few mm and can reach values of the order of one or two tens of
mm.
[0029] Such a configuration of the notches 204 is required for the
following reasons:
[0030] As stated above, the sheet 201, once already die-cut and
profiled, is fed at the entrance of the packaging machine. At the
entrance of the packaging machine, the sheet 201, passing from the
substantially vertical feeding plane to the substantially
horizontal sliding plane, undergoes a deviation of about
90.degree., during which it is longitudinally creased to define the
first crease 202 and the second crease 203. This passage is a very
critical point of the packaging machine. At this point, indeed, due
to the tensions to which the sheet itself is subjected, the risks
of crinkling and tearing of the sheet are very high and, on the one
hand, do not allow the use of low grammage papers, which would tear
very easily, and, on the other hand, force the advancement speed of
the sheet itself to be kept low and, therefore, slowing down
production. If each notch 204 had a depth such as to reach the
second crease 203, such risks and the consequent effects would be
further accentuated. Therefore, it becomes necessary to distance
the bottom 204c of each notch 204 from the second crease 203 by a
non-zero distance d.
[0031] Moreover, while the continuous sheet advances along the
machine, inevitable slippings or in any case errors in pulling the
sheet itself and/or errors in phasing the various processings
carried out on it may occur. In particular, the transversal cut
that separates the single envelopes is carried out a few metres
after the entrance of the continuous sheet in the machine and, in
particular, a few metres after the folding of the first leaf and of
the second leaf to form the flat tubular wrapping. If the notches
204 were shaped like a "V", it would, therefore, be practically
impossible to centre the transversal cut with the vertex of each
notch 2041. In order, therefore, to mask the phasing error of the
transversal cuts with respect to the position of the notches 204 it
becomes necessary to distance the first flank 204a and the second
flank 204b of each notch by a distance defined by the rectilinear
portion 204c of length l and along which the separation line 205 at
which the transversal cut that separates two successive envelopes
will be defined.
[0032] From what has been outlined above it is clear that the known
solutions impose a series of constraints and limitations to the
design of the envelopes and, in particular, to the design of the
profile of their closing flap or "tab" that, on the one hand, do
not allow the design of standard type pre-formed envelopes to be
exactly copied and, on the other hand, could require the use of a
continuous sheet of paper that is oversized in length and/or in
width that is reflected in greater material costs.
[0033] A further drawback of known solutions consists of the fact
that they require the provision of a die-cutting apparatus, be it
arranged "off-line" or "in line" with the packaging machine, which
can be separate from the latter and that, due to the bulk that it
occupies, requires a space that is not always available.
[0034] In the case in which such a die-cutting apparatus is
arranged "in line" with the packaging machine, moreover, it could
require the preparation of storage units of the sheet of paper that
further complicate the structure, the operation and the management
of the entire packaging plant.
[0035] The die-cutter, indeed, consists of a drum with a
circumference equal to the length of the envelope to be made or to
a multiple of such a length that, for envelopes of standard format
type C6, C5 and C4, varies between about 165 mm, 230 mm and 350 mm
(162 mm, 229 mm and 324 mm, respectively). Envelopes of different
format and, in particular, of different length, correspond to drum
die-cuts with different format. The high inertia of the rotation of
the drum of the die-cutter and the different speed of forward
movement that the continuous sheet of paper can have during
die-cutting and during processing in the machine can, indeed,
require the provision of storage units before and after the
die-cutter itself. As the format of the envelope to be made varies
and, in particular, as the length of the envelopes varies it is
necessary to change the drum of the die-cutter, with complicated
and long replacement operations and, therefore, stopping operations
of the packaging machine.
[0036] Known solutions, moreover, are expensive to install,
maintain and manage, which reflects in a greater unitary cost of
the single envelopes produced.
[0037] Yet another drawback of known solutions consists of the fact
that the presence in the continuous sheet of paper of transversal
notches that are pre-formed in it before it is fed at the entrance
of the packaging machine itself further weakens the sheet itself,
making its passage from the feeding plane to the sliding plane with
a deviation of about 90.degree. particularly critical. Known
solutions, therefore, do not allow low grammage papers to be used,
which would tear very easily and force the advancement speed of the
sheet itself to be kept low and, therefore, forcing production to
be slowed down.
[0038] Yet another drawback of known solutions consists of the fact
that they require the die-cutting of the continuous sheet of paper
to be carried out before it is fed to the packaging machine, which,
in particular in the case in which the die-cutting is carried out
"off-line", slows down production further, being it necessary to
prepare the reels of pre-die-cut sheet before the start of the
packaging processing of the envelopes.
[0039] The purpose of the present invention is to make an automatic
packaging machine for continuously packaging products, each wrapped
in a single envelope, and to propose a method for continuously
packaging products, each wrapped in a single envelope, which allow
the drawbacks of the prior art to be avoided.
[0040] In this general purpose, a particular purpose of the present
invention is to make an automatic packaging machine for
continuously packaging products, each wrapped in a single envelope,
and to propose a method for continuously packaging products, each
wrapped in a single envelope, which allow to obtain envelopes the
design of which copies that of standard pre-formed envelopes and to
keep low the dimensions of the continuous sheet of paper necessary
to make them, with consequent reduction of the material costs.
[0041] Yet another purpose of the present invention is to make an
automatic packaging machine for continuously packaging products,
each wrapped in a single envelope, and to propose a method for
continuously packaging products, each wrapped in a single envelope,
which allow to also use low grammage papers and/or to increase the
operating packaging speed, with a consequent increase in production
and reduction of the material costs.
[0042] Yet another purpose of the present invention is to make an
automatic packaging machine for continuously packaging products,
each wrapped in a single envelope, which is structurally and
constructively simple and the operation of which is flexible and
versatile making it easier, in particular, to change format of the
envelope to be obtained and reducing the time for processing the
single formats and for changing them.
[0043] These purposes according to the present invention are
accomplished by making an automatic packaging machine for
continuously packaging products, each wrapped in a single envelope,
as outlined in claim 1.
[0044] These purposes according to the present invention are
accomplished with a method for continuously packaging products,
each wrapped in a single envelope, as outlined in claim 16.
[0045] Further characteristics are provided in the dependent
claims.
[0046] The characteristics and advantages of an automatic packaging
machine for continuously packaging products, each wrapped in a
single envelope, and of a method for continuously packaging
products, each wrapped in a single envelope, according to the
present invention will become clearer from the following
description, given as an example and not for limiting purposes,
referring to the attached schematic drawings, in which:
[0047] FIG. 1 is a schematic axonometric view of an automatic
packaging machine according to the present invention associated
with a feeding unit of products to be packaged and with an
unwinding unit of the continuous sheet of packaging material from a
reel;
[0048] FIG. 2 is a schematic axonometric view of the entrance end
of the conveyor of the machine of FIG. 1;
[0049] FIG. 3 is a schematic view of a detail of the machine of
FIG. 1 on an enlarged scale and seen axonometrically from
above;
[0050] FIG. 4 is a schematic view of the sole die-cutting unit of
the machine of FIG. 1;
[0051] FIG. 5 is a schematic axonometric view of the die-cutting
unit of the machine of FIG. 1 with a unit for removing the
die-cutting waste applied;
[0052] FIG. 6 is a schematic axonometric view of a detail of the
die-cutting unit of FIG. 4 or 5;
[0053] FIG. 7 is a schematic axonometric view of a detail of a
first possible alternative embodiment of the packaging machine
according to the present invention;
[0054] FIG. 8 is a schematic axonometric view of a second possible
alternative embodiment of the packaging machine according to the
present invention associated with a feeding unit of products to be
packaged and with a unit for unwinding the continuous sheet of
packaging material from a reel;
[0055] FIG. 9 is a schematic axonometric view of a detail of the
packaging machine of FIG. 8;
[0056] FIG. 10 is a schematic view of the detail of FIG. 9 from a
different angle;
[0057] FIG. 11 shows a detail of FIG. 10 on an enlarged scale;
[0058] FIGS. 12A to 12D schematically show the sequence of stages
in which the die-cutting step according to the present invention
develops, carried out, at least in part, at the same time as the
pressing step;
[0059] FIGS. 13A and 13B respectively show a portion of the
continuous sheet of packaging material after the die-cutting
carried out on the packaging machine according to the present
invention and a detail thereof on an enlarged scale;
[0060] FIGS. 14A and 14B respectively show a reel of a pre-die-cut
sheet and a portion of a pre-die-cut sheet according to the prior
art;
[0061] FIG. 14C shows a detail of FIG. 14B on an enlarged
scale;
[0062] FIG. 15 schematically and axonometrically shows the entrance
end of a third possible alternative embodiment of the packaging
machine according to the present invention.
[0063] With reference to the attached figures, reference numeral 10
wholly indicates an automatic packaging machine for continuously
packaging products P each wrapped in a single envelope B obtained
from a continuous sheet F according to the present invention.
[0064] The sheet F is made of packaging material consisting, in
particular, of paper, although it should not be excluded the
possibility that the sheet F be made of different packaging
materials. In the rest of the description, for the sake of
simplicity, reference will be made to a continuous sheet F of
paper.
[0065] The machine 10 is of the type suitable for producing
packages consisting of envelopes B each containing inside it a
product P of the type, in particular, of a printed product, whether
it consists of a sheet, a folded sheet, a fascicle of sheets, an
insert or similar.
[0066] The machine 10, in particular, is of the type suitable for
producing packages the envelope B of which consists of a single
front B1 and of a back in turn consisting of two flaps B2 and B3 at
least partially overlapped and a first flap B2 of which is of
greater height and defines the actual back of the envelope B and a
second flap B3 of which is of lesser height and defines the closing
flap or closing "tab" of the envelope B. The envelope B can be
closed at least at one of the opposite sides B4 and B5, as well as
longitudinally at the portion of the closing flap or "tab" B3 which
is overlapped on the back B2, by means of strips of adhesive or
glue applied to the sheet F.
[0067] The machine 10 is of the automatic and continuously
operating type.
[0068] The machine 10 comprises a support frame 11 for resting on
the ground, said frame being associated with a conveyor 12 defining
a conveying plane, indicated by the line PT, for conveying the
sheet F along a conveying direction indicated by the line DT.
[0069] The conveyor 12, as will become clearer hereafter, does not
necessarily have a uniform and continuous structure and, can
consist, for some portions thereof, of conveyor belts 13, 13', 13''
and 14 and, for some other portions thereof, of conveying rollers
15, 16, 17 that are arranged between successive conveyor belts 13'
and 13'' and 13 and 14 and that also act as contrast elements of
members of corresponding operative units of the machine 10.
[0070] In any case, the conveyor 12 defines a movable conveying
plane PT that allows the sheet F to be moved forward along the
conveying direction DT in the sense indicated by the arrow A2.
[0071] The conveying plane PT or in any case the conveyor 12
defines an entrance end 12a of the sheet F and an exit end 12b of
the packaged envelopes B and each containing a product P and
schematically indicated in FIGS. 1, 2 and 8 by respective
lines.
[0072] Moreover, the conveying plane PT or in any case the conveyor
12 has two opposite sides parallel to the conveying direction
DT.
[0073] The frame 11 supports a feeding unit 18 of the sheet F which
is arranged below the conveyor 12.
[0074] The feeding unit 18 receives at the entrance the sheet F
unwound from a reel 19 by an unwinding unit 20 associated with the
machine 10.
[0075] The feeding unit 18 comprises a plurality of return rollers
and deviator rollers generically indicated with 21 that deviate and
move forward the sheet F unwound from the reel 19 along a feeding
plane indicated by the line PA along a direction of forward
movement DA substantially orthogonal to the conveying plane PT and
in the sense of feeding indicated by the arrow A1.
[0076] The feeding plane PA extends below the conveying plane PT,
is orthogonal or substantially orthogonal to the conveying
direction DT and is defined at the entrance end 12a of the conveyor
12 or in any case at the conveying plane PT (FIGS. 1, 2 and 8).
[0077] It should be specified that the feeding plane PA is
orthogonal or substantially orthogonal to the conveying direction
DT except for an angle that is generally less than 30.degree. and
equal, in particular, to 4.degree.-5.degree..
[0078] It should also be specified that the feeding direction DA is
orthogonal or substantially orthogonal to the conveying plane PT
except for an angle that is generally less than 30.degree. and
equal, in particular, to 4.degree.-5.degree..
[0079] In practice, the conveying plane PT is substantially
horizontal and the feeding plane PA is substantially vertical.
[0080] While passing from the feeding plane PA to the conveying
plane PT, the sheet F is therefore deviated from the bottom upwards
by a right angle or substantially a right angle.
[0081] The feeding unit 18 can also comprise application devices
for applying, on the face of the sheet F that, considering the
sheet F resting on the conveying plane PT, faces upwards or in any
case opposite to the conveying plane PT itself, strips S', S'' of
glue or adhesive at the transversal portions thereof intended to
constitute the closures at the sides B4 and/or B5 of each envelope
B and, possibly, longitudinal strips S''' of glue along the
longitudinal sections of the sheet F intended to form the closing
flaps or closing "tabs" B3 of the single envelopes B. These
application devices of strips of glue or adhesive are not
represented in the attached figures (except for FIG. 7), since they
are of the type known to the person skilled in the art.
[0082] Upstream of the entrance end 12a of the conveyor 12 or in
any case of the conveying plane PT there is a feeding unit 22 for
feeding the products P to be packaged in single envelopes B and
which are fed in succession one after the other and at a distance
from one another on the sheet F entering the conveying plane
PT.
[0083] The feeding unit 22 in turn comprises a support frame 23 for
resting on the ground and that supports a continuous conveyor of
the type, for example, using belts or chains 24 equipped with a
plurality of so-called "carriers" 25 that separate and push the
single products P one in succession after the other and one spaced
from the other along a conveying direction coinciding with the
conveying direction DT of the sheet F and in the same sense of
forward motion A2.
[0084] At the entrance end 12a of the conveyor 12 or in any case of
the conveying plane PT there is a creasing unit 26 of the sheet F
that is designed to define in the sheet F a pair of longitudinal
folding creases, each of which defines a respective continuous
longitudinal leaf of the sheet F, and to accompany the overturning
of these two longitudinal leaves from the feeding plane PA to the
conveying plane PT.
[0085] In more detail, the creasing unit 26 defines in the sheet F
a first longitudinal crease C1, which defines a first continuous
longitudinal leaf F1 of the sheet F and that is intended to
constitute the back B2 of the envelopes B, and a second
longitudinal crease C2, which defines a second continuous
longitudinal leaf F2 of the sheet F and that is intended to
constitute the closing flap or "tab" B3 of the envelopes B. Between
the first longitudinal leaf F1 and the second longitudinal leaf F2
a longitudinal central portion F3 of the sheet F is defined, on
which central portion the products P, which are fed by the feeding
unit 22 in succession one after another and at a distance one from
another, are arranged.
[0086] The creasing unit 26 comprises for each of the two opposite
sides of the conveyor 12 or in any case of the conveying plane PT a
respective block 26' provided with a rectilinear edge that faces
the feeding plane PA and that is substantially parallel to the
feeding direction DA so as to define a longitudinal creasing
element of the sheet F for folding a corresponding longitudinal
leaf F1, F2 thereof or corresponding parts thereof.
[0087] In the attached figures, the creasing elements are only
schematically represented in FIG. 2, being of the type known to the
person skilled in the art.
[0088] According to a peculiar feature of the present invention,
the packaging machine 10 comprises at least one die-cutting unit 27
for die-cutting at least one of the first longitudinal leaf F1, or
in any case the longitudinal portion of the sheet F that defines
the first longitudinal leaf F1, and the second longitudinal leaf
F2, or in any case the longitudinal portion of the sheet F that
defines the second longitudinal leaf F2, to die-cut in it the back
B2 and/or the profile of the back B2 and the closing flap or "tab"
B3 and/or the profile of the closing flap or "tab" B3,
respectively, in which such a die-cutting unit 27 is arranged
between the entrance end 12a and the exit end 12b of the conveying
plane PT to act on the sheet F fed on the conveying plane PT, after
such a sheet F has undergone the deviation by 90.degree. to pass
from the feeding plane PA to the conveying plane PT.
[0089] As will become clearer from the following description, the
at least one die-cutting unit 27 can consist of a unit separate and
distinct from the remaining operative units arranged along the
conveying plane PT to carry out the different processing operations
necessary to obtain the single envelopes B or it can be integrated
or in any case incorporated in one of such operative units, like
for example the pressing unit or the transversal cutting unit
described hereafter.
[0090] The at least one die-cutting unit 27 is provided for
die-cutting, in particular, the outer longitudinal edge,
respectively, of the first longitudinal leaf F1 and/or of the
second longitudinal leaf F2, i.e. the longitudinal edge of the
first longitudinal leaf F1 and/or of the second longitudinal leaf
F2 opposite, respectively, to the first longitudinal crease C1 and
to the second longitudinal crease C2.
[0091] In particular, the at least one die-cutting unit 27 is
arranged to die-cut the second longitudinal leaf F2 to define in it
the profile of the closing flap or "tab" B3 of the envelopes B,
i.e. the profile of the outer longitudinal edge of the second
longitudinal leaf F2 opposite to the second longitudinal crease C2
and/or to define in it a plurality of perforations, toothings or
incisions for tamper-proofing that, in other words, highlight the
fact that the envelope B has been opened.
[0092] With reference to the first embodiment represented in FIGS.
1 to 6, the machine 10 comprises a first folding unit 28 for
folding the first longitudinal leaf F1 on the longitudinal central
portion F3 of the sheet F so as to at least partially cover the
products P present on it and form the back B2 of the envelopes B
and thus obtain a continuous wrapping containing the products P,
closed along the side defined by the first longitudinal crease C1
and open at the opposite side.
[0093] The first folding unit 28 is arranged downstream, with
respect to the sense of forward motion A2 of the sheet F along the
conveying direction DT, of the creasing unit 26 and comprises, in a
known manner, folding bars 28' that extend above the conveying
plane PT and incident and/or parallel to it.
[0094] The second longitudinal leaf F2, on the other hand, remains
laid on the conveying plane PT and, if in the passage from the
feeding plane PA to the conveying plane PT it is accompanied by a
partial folding, once the conveying plane PT has been reached it
would be reopened and laid on it.
[0095] The machine 10 also comprises, in succession one after the
other in the sense of forward motion A2 of the sheet F along the
conveying direction DT: a pressing unit 29 arranged downstream of
the first folding unit 28 and a transversal cutting unit 30
arranged downstream of the pressing unit 29.
[0096] The pressing unit 29 is designed to exert a pressure on the
first longitudinal leaf F1 folded over the longitudinal central
portion F3 at the transversal strips S', S'' of adhesive or glue
present or in any case applied on the face of the sheet F opposite
to the one resting on the conveying plane PT at at least one
segment of at least one of the two transversal sides of each
longitudinal section of the sheet F that defines a corresponding
envelope B, so that each envelope B is closed on one or both of the
opposite sides B4 and B5.
[0097] The transversal cutting unit 30 is designed to transversally
cut the continuous wrapping obtained by folding at least the first
longitudinal leaf F1 on the longitudinal central portion F3 (and
possibly by folding the second longitudinal leaf F2 on the first
longitudinal leaf F1 that is already folded) between two successive
products P so as to obtain a plurality of longitudinal sections of
such a continuous wrapping that are separate from one another and
each defining a respective envelope B.
[0098] In such an embodiment, the die-cutting unit 27 is arranged
between the creasing unit 26 and the transversal cutting unit 30
and, preferably, is arranged downstream, i.e. after, of the first
folding unit 28 and upstream, i.e. before, of the pressing unit
29.
[0099] In more detail and with reference to the embodiment
represented in FIGS. 1 to 6, the die-cutting unit 27 consists of a
separate and independent unit that is arranged between the first
folding unit 28 and the pressing unit 29 between two successive
portions 13' and 13'' of the conveyor belt 13. This does not
exclude alternative embodiments, in which, for example, the
die-cutting unit 27 consists of a separate unit arranged between
the pressing unit 29 and the cutting unit 30.
[0100] It should be noted that, in a known manner, the conveyor
belt 13, or in any case its portions 13', 13'', and the conveyor
belt 14 each have perforations 130, 140 that are in communication
with a suction unit to hold the sheet F, the sections thereof or
the envelopes B adhering to the conveyor belts themselves and allow
them to be moved forward along the conveying direction DT. For this
purpose, moreover, a plurality of pressure rollers 31 is arranged
above the conveying plane PT to cooperate with the conveyor belts
13 and 14.
[0101] The die-cutting unit 27 comprises an own shaft 32 that is
rotatably supported above the conveying plane PT by means of a pair
of supports 33, is arranged with its longitudinal axis parallel to
the conveying plane PT and orthogonal to the conveying direction DT
and is associated with own motor means 34 controlled by the control
unit, not shown.
[0102] A die-cutter 35 is mounted on the shaft 32 in a fixed manner
with respect to translation and rotation, which die-cutter consists
of a drum sector or segment on the outer side surface of which a
die-cutting cutting profile 36 is defined.
[0103] The die-cutter 35 is mounted on the shaft 32 at the
longitudinal portion thereof that is arranged above the second
longitudinal leaf F2.
[0104] The die-cutting unit 27 also comprises a contrast element
for contrasting the die-cutter 35 and which is of the type of a
roller 17, a belt or similar, which simultaneously acts as a
conveying element.
[0105] The roller 17 is arranged between the portions 13' and 13''
of the conveyor belt 13 and is made to rotate in the opposite sense
to that of the shaft 32 by a transmission unit, not
represented.
[0106] The cutting profile 36 is configured to define in the second
longitudinal leaf F2 a plurality of transversal notches I,
described later on, which define the profile of the closing flap or
"tab" B3 of each envelope B. In an alternative embodiment, not
shown, the cutting profile 36 is configured to define in the second
longitudinal leaf F2 a plurality of perforations or incisions for
tamper-proofing.
[0107] This does not exclude alternative embodiments, wherein the
same die-cutter 35 is equipped with more than one cutting profile
operating in succession and/or at least in part simultaneously with
one another or wherein the packaging machine 10 comprises more than
one die-cutting unit 27 each suitable for carrying out different
die-cutting on the second longitudinal leaf F2, for example one to
carry out a plurality of tamper-proofing perforations in it and one
to carry out a plurality of transversal notches I in it defining
the profile of the closing flap or "tab" B3 of each envelope. The
same die-cutter 35 could also consist of a full drum with diameter
substantially equal to the length of the envelopes B to be made,
and this, in particular, in the case in which it is wished to make
perforations or incisions along the entire length of each closing
flap and/or it is wished to rotate the die-cutter always at the
same speed of forward motion of the sheet F along the conveying
plane PT.
[0108] At an end of the shaft 32 there is a joint 37 with an
air-suction/blowing circuit, not represented since it is of the
type easy for the person skilled in the art to understand. The
joint 37 is in fluid communication with a hole 38 formed near the
cutting profile 36, to hold, during die-cutting, the cutting waste
and to release it, after die-cutting, so that it is removed by a
removal or discharging unit 39 schematically represented in FIG.
5.
[0109] Downstream, with respect to the sense of forward motion A2
of the sheet F along the conveying direction DT, of the die-cutting
unit 27 a second folding unit 40 is arranged for folding the second
longitudinal leaf F2 on the already folded first longitudinal leaf
F1, so that the portions thereof that define the closing flaps or
"tabs" B3 of each envelope B at least partially overlap on the
first longitudinal leaf F1 already folded to define the
corresponding back B2.
[0110] In the embodiment represented in FIGS. 1 and 3, the second
folding unit 40 is arranged between the die-cutting unit 27 and the
pressing unit 29, the sheet F fed at the entrance of the conveying
plane PT being already provided with longitudinal strips S''' of
glue applied along portions of the second longitudinal leaf F2
corresponding to the closing flaps or "tabs" B3.
[0111] In an alternative embodiment of the packaging machine 10 as
represented in FIG. 7, the sheet F fed on the conveying plane PT
lacks the longitudinal strips S''' of glue and downstream, with
respect to the sense of forward motion A2 of the sheet F along the
conveying direction DT, of the die-cutting unit 27 and upstream of
the second folding unit 40 an application unit 41 of the
longitudinal strips S''' of glue is arranged. Also in this case the
second folding unit 40 and, therefore, the application unit 41 that
precedes it, is arranged between the die-cutting unit 27 and the
pressing unit 29. However, this does not exclude the possibility
that both the application unit 41 and the second folding unit 40 or
even just the second folding unit 40 are arranged downstream of the
transversal cutting unit 30.
[0112] Again with reference to the embodiments represented in FIGS.
1 to 7, the pressing unit 29 comprises a shaft 42 that is rotatably
supported about its longitudinal axis and above the conveying plane
PT by a pair of supports 43.
[0113] The shaft 42 extends parallel to the conveying plane PT and
perpendicular to the conveying direction DT and it is associated
with motor means suitable for making it to rotate. The motor means
are of the electric type and are commanded by a control unit, not
represented in the attached figures and that controls the operation
of the entire machine 10.
[0114] At least one pressing element 44 is mounted on the shaft 42
in a fixed manner with respect to rotation and translation, the
pressing element consists of a sector of a cylindrical drum that is
coaxial to the shaft 42 itself and that extends for a length
substantially equal to that of the longitudinal central portion F3
of the sheet F and at the latter.
[0115] The pressing unit 29 also comprises the roller 15 that is
rotatably supported about its longitudinal axis by respective
supports and that is arranged below the shaft 42 with its axis
parallel to that of the shaft 42, to act simultaneously as
conveying element and as contrast element of the pressing element
44.
[0116] The transversal cutting unit 30 in turn comprises a drum 45
that is mounted on a shaft rotatably supported above the conveying
plane PT by a pair of respective supports and that is arranged with
its longitudinal axis parallel to the conveying plane PT and
orthogonal to the conveying direction DT. Motor means make support
shaft of the drum 45 rotate. The drum 45 in turn carries one or
more cutting blades or elements that are arranged along radial
planes thereof to cut the continuous wrapping--which consists of
the sheet F with the first longitudinal leaf F1 folded over the
longitudinal central portion F3 to cover the products P and the
second longitudinal leaf F2 die-cut and folded over the first
longitudinal leaf F1--between two successive products P. In this
case the conveying roller 16 acts as contrast element of the
cutting elements or blades and is arranged below the drum 45 with
its axis parallel to that of the drum 45 itself. The drum 45 and
the conveying roller 16 rotate in opposite senses.
[0117] The pressing unit 29 and the transversal cutting unit 30 are
not detailed any further, being of the known type.
[0118] The alternative embodiment of the packaging machine 10
represented in FIGS. 8 to 12D, differs from the one represented in
FIGS. 1 to 7 in that the die-cutting unit 27, which is designed to
die-cut the second longitudinal leaf F2 to die-cut in it the
closing flap or "tab" B3 of each envelope B or define its profile,
is integrated or in any case incorporated in the pressing unit
29.
[0119] In describing such an alternative embodiment of the
packaging machine 10 elements corresponding to those of the
packaging machine 10 represented in FIGS. 1 to 7 will be indicated
with the same reference numeral possibly indexed.
[0120] In more detail, the die-cutting unit 27 is integrated or in
any case incorporated in the pressing unit 29 and comprises a
die-cutter 35' consisting of a drum sector or segment mounted
coaxially to the shaft 42 of the pressing unit 29 so as to rotate
and translate as a unit with it.
[0121] The die-cutter 35' is mounted close to the end of the
pressing element 44 facing towards the second longitudinal crease
C2.
[0122] The roller 15 extends below the die-cutter 35' to act as
contrast element also of the latter.
[0123] In a totally analogous way to the embodiment represented in
FIGS. 1 to 6, the die-cutter 35' comprises a cutting profile 36'
and the shaft 42 has, at one end, a joint 37' to an air
suction/blowing unit that is in fluid communication with a hole 38'
formed near to the cutting profile 36' for holding and removing the
die-cutting waste carried out by a removal or discharging unit
analogous to the one represented in FIG. 5.
[0124] As can be seen from FIGS. 12A-12D the arc of circumference
that defines the die-cutter 35' has a greater width than the arc of
circumference that defines the pressing element 44, such arcs being
mutually centred and symmetrically arranged with respect to a
radial plane of the shaft 42.
[0125] The shaft 42 of the pressing unit 29, therefore,
simultaneously makes both the pressing element 44 and the
die-cutter 35' rotate, the intervention times of these on the sheet
F overlap and coincide for the angle of rotation of the shaft 42
corresponding to the angle subtended to the arc of circumference
that defines the pressing element 44.
[0126] Also in this case, alternative embodiments of the die-cutter
35' as described above with reference to the embodiment of FIGS.
1-7 are not excluded.
[0127] Downstream, with respect to the sense of forward motion A2
of the sheet F along the conveying direction DT, of the cutting
unit 30 a second folding unit 40 is arranged for folding the
closing flap B3 of each envelope B over the respective back B2.
[0128] In the embodiment represented in FIGS. 8 to 12D, the sheet F
fed at the entrance of the conveying plane PT is already provided
with longitudinal strips S''' of glue applied along portions of the
second longitudinal leaf corresponding to the closing flaps or
"tabs" B3.
[0129] In an alternative embodiment of the packaging machine 10,
not represented, the sheet F fed on the conveying plane PT lacks
the longitudinal strips S''' of glue and downstream, with respect
to the sense of forward motion A2 of the sheet F along the
conveying direction DT, of the transversal cutting unit 30 and
upstream of the second folding unit 40 an application unit 41 is
arranged for applying the longitudinal strips S''' of glue. Also in
this case, the second folding unit 40 and, therefore, the
application unit 41 that precedes it, are arranged downstream of
the transversal cutting unit 30.
[0130] In the embodiments represented in the attached figures, the
die-cutter 35, 35' is equipped with a cutting profile 36, 36'
designed to die-cut in the second longitudinal leaf F2 a plurality
of transversal notches I.
[0131] Each notch I comprises a first flank I1 and a second flank
I2 that are angled to one another and convergent towards the second
longitudinal crease C2 and that define the profile at an end of the
closing flap B3 of two consecutive envelopes B.
[0132] As can be noted from FIGS. 13A and 13B, the first flank I1
and the second flank I2 of each transversal notch I intersect in a
"V" with the vertex of the "V" substantially at the second
longitudinal folding crease C2 of the second longitudinal leaf F2,
i.e. in correspondence with it except for processing
tolerances.
[0133] With reference to the embodiment of the packaging machine 10
represented in FIG. 15, at least one auxiliary die-cutting unit
270, which is integrated or in any case incorporated in the feeding
unit 18, is provided to die-cut, in the longitudinal central
portion F3 or in any case in the portion of the sheet F that
defines it, a window FS at each front B1 of each envelope. As an
alternative to the window FS, the auxiliary die-cutting unit 270
could define holes of different shape or in any case openings,
perforations or other in the longitudinal central portion F3.
[0134] Moreover, the same or other auxiliary die-cutting unit 270
could be provided for die-cutting the first longitudinal leaf F1 or
in any case the longitudinal portion of the sheet F that defines it
to define in it the profile of the edge that defines the back B2 of
each envelope and/or perforations, incisions, toothings, in
particular for tamper-proofing.
[0135] Advantageously, the die-cutting unit 270 is arranged to act
on the sheet F moving forward along the feeding plane PA and
comprises a shaft 271 that is rotatably supported with its axis
parallel to the plane PA and orthogonal to the feeding direction DA
and that is associated with motor means, not represented, suitable
for making it rotate.
[0136] On the shaft 271 a respective die-cutter 272 is mounted, the
die-cutter being provided with a drum sector or segment having a
cutting profile 273.
[0137] The die-cutting unit 270 also comprises a contrast element
for contrasting the die-cutter 272, said contrast element being
opposite the shaft 271 and consisting of a roller, a belt or
similar.
[0138] It should be specified that the auxiliary die-cutting unit
270 could be applied on a packaging machine 10 as represented in
FIGS. 1 to 12D, i.e. wherein a further die-cutting unit 27 is
arranged between the entrance end 12a and the exit end 12b of the
conveying plane to die-cut the sheet F and, in particular, the
second longitudinal leaf F2 thereof, only after it has been fed on
the conveying plane PT after the deviation at 90.degree., as well
as on packaging machines of the known type, i.e. in which the sheet
F fed is already pre-die-cut.
[0139] In both cases, a possible application unit for applying a
transparent film on each window FS could be arranged downstream of
the auxiliary die-cutting unit 270 and before the feeding of the
products P on the longitudinal central portion F3 of the sheet
F.
[0140] The operation of a machine 10 according to the present
invention can be immediately understood by a person skilled in the
art in light of the attached figures and the description given
above.
[0141] With reference to the embodiment represented in FIGS. 1 to
6, the sheet F is unwound from the reel 19 by the unreeling unit 20
that feeds it at the entrance of the feeding unit 18 of the machine
10.
[0142] The feeding unit 18 deviates and feeds the sheet F along the
substantially vertical feeding plane PA. Along the path followed by
the sheet F while passing through the feeding unit 18 at least one
application device is arranged for applying a plurality of strips
S', S'' of glue or adhesive on the face of the sheet F intended to
constitute the inside of each envelope B and on at least one
segment of at least one of the two transversal sides of each
longitudinal portion of the sheet F that defines a corresponding
envelope B.
[0143] Along the path followed by the sheet F while passing through
the feeding unit 18, moreover, at least one further application
device is arranged for applying a plurality of strips S''' of glue
or adhesive on the face of the sheet F intended to constitute the
inside of each envelope B and on the portions of the second
longitudinal leaf F2 intended to form the flap or the closing "tab"
B3 of each envelope B.
[0144] While passing from the feeding plane PA to the conveying
plane PT, undergoing a deviation and an overturning of about
90.degree., the sheet F is creased by the creasing unit 26 that
defines in it the first longitudinal crease C1 and the second
longitudinal crease C2 for respectively folding the first
longitudinal leaf F1 and the second longitudinal leaf F2.
[0145] At the entrance end 12a of the conveyor 12 or in any case of
the conveying plane PT, the feeding unit 22 associated with the
machine 10 feeds the products P one in succession of the other and
one after another on the longitudinal central portion F3 of the
sheet F defined by the first longitudinal leaf F1 and by the second
longitudinal leaf F2, so that each product P rests on the
longitudinal portion of the sheet F intended to form a respective
envelope B and is arranged between the transversal strips S', S''
of glue or adhesive at the opposite sides B4 and B5 of the
respective envelope B.
[0146] The first folding unit 28 folds the first longitudinal leaf
F1 on the longitudinal central portion F3 so as to cover the
products P and obtain a continuous wrapping closed along the first
longitudinal crease C1 and open along the opposite side, where the
second longitudinal leaf F2 rests on the conveying plane PT.
[0147] The continuous wrapping thus obtained passes through the
die-cutting unit 27 that die-cuts the second longitudinal leaf F2
cutting a plurality of transversal notches I in it. During the
angle of rotation of the shaft 32 necessary to carry out the
die-cutting and for an angle of rotation subsequent to it, the
cutting waste is held stuck to the die-cutter 35 by means of a
suction action applied through the hole 38. After this, the cutting
waste is removed by the removal unit 39 that, for example, sucks it
up, while an air jet is blown through the hole 38.
[0148] At the exit from the die-cutting unit 27 the second
longitudinal leaf F2 has a plurality of transversal notches I the
flanks I1 and I2 of which define the bevel at one of the opposite
ends of the closing flaps or "tabs" B3 of two successive
envelopes.
[0149] At the exit from the die-cutting unit 27 the second
longitudinal leaf F2 thus die-cut is folded by the second folding
unit 40 on the continuous wrapping to form the closing flaps or
"tabs" B3 of the single envelopes B.
[0150] The continuous tubular wrapping thus obtained then passes
through the pressing unit 29, which presses the first longitudinal
leaf F1 on the longitudinal central portion F3 at the transversal
strips of glue S' and S''', and then the transversal cutting unit
30 that cuts the continuous tubular wrapping between two successive
products at the separation line LS that is centred with respect to
the corresponding pair of transversal strips S', S'' of glue and to
the vertex of the corresponding notch I, thus obtaining single
closed envelopes B.
[0151] The operation of the packaging machine 10 represented in
FIG. 7 is totally analogous to that indicated above, excluding the
fact that the longitudinal strips of glue S''' are applied
downstream of the die-cutting unit 27 and upstream of the second
folding unit 40.
[0152] The operation of the packaging machine 10 represented in
FIGS. 8 to 12D differs from that described above in that the
continuous wrapping exiting from the first folding unit 28 passes
through the pressing unit 29 in which the die-cutting unit 27 is
integrated, so that the die-cutting of the second longitudinal leaf
F2 is carried out at least in part simultaneously with the pressing
of the transversal strips of glue S' and S''.
[0153] As schematically represented in FIGS. 12A to 12D as the
tubular wrapping moves forwards in the sense of forward motion A2
along the conveying direction DT, the shaft 42 makes the die-cutter
35' to act on the second longitudinal leaf F2 where it starts to
cut the first flank I1 of a transversal notch I.
[0154] After the shaft 42 has completed a rotation by an angle
.alpha..sub.1 from the start of the intervention of the die-cutter
35' on the second longitudinal leaf F2, the pressing element 44
starts to contact the first longitudinal leaf F1 pressing it on the
longitudinal central portion F3 of the sheet F at the transversal
strip S' of glue applied at the end of the longitudinal portion of
the sheet F that defines the side B5 of an envelope B.
[0155] During a subsequent angle of rotation .alpha..sub.2 of the
shaft 42 and substantially equal to the angle subtended at the arc
of circumference that defines the pressing element 44, the
die-cutter 35' and the pressing element 44 act simultaneously
respectively to press the first longitudinal leaf F1 on the
longitudinal central portion F3 of the sheet F at the transversal
strips S' and S'' of glue applied to the adjacent ends of two
successive longitudinal portions of the sheet F that define the
side B5 and the side B4 of two successive envelopes and to start to
notch the second flank I2 of the transversal notch I.
[0156] During a subsequent angle of rotation .alpha..sub.3 of the
shaft 42, the die-cutter 35' completes the incision of the second
flank I2 of the transversal notch I, the pressing element 44 having
already ended its pressing action.
[0157] At the exit from the pressing unit 29 having the die-cutting
unit 27 integrated thereto, the second longitudinal leaf F2 has a
plurality of transversal notches I, the flanks I1 and I2 of which
define the bevel at one of the opposite ends of the closing flaps
or "tabs" B3 of two successive envelopes, and the first
longitudinal leaf F1 folded on the longitudinal central portion F3
adheres to the latter at the transversal strips of glue S' and
S''.
[0158] The continuous wrapping thus obtained then passes through
the transversal cutting unit 30 that cuts it at the separation line
LS between two successive longitudinal sections of the sheet F that
define a respective envelope B and that is centred with respect to
the corresponding pair of transversal strips S', S'' of glue and to
the vertex of the corresponding notch I.
[0159] At the exit from the transversal cutting unit 30 single
envelopes B are thus obtained each containing a product P and
closed at the opposite sides B4 and B5 and with the closing flap B3
profiled at the opposite ends with a respective bevel defined,
respectively, by the second flank I2 and by the first flank I1 of
two successive transversal notches I.
[0160] The closing flap B3 of each envelope B is then folded on the
back B2 thereof by the second folding unit 40.
[0161] From the above it is clear, therefore, that the rotation of
the shaft which carries the die-cutter 35, 35' (being it a
dedicated shaft 32 or the shaft 42 of the pressing unit 29 or of
another operative unit) between two successive die-cutting (and
possibly pressing or other processing) operations and during which
neither the die-cutter 35, 35' nor any other possible operative
element (the pressing element 44) supported by such a same shaft is
in contact with the tubular wrapping can be controlled at a
different speed from that of forward movement of the tubular
wrapping itself along the direction of forward movement DT. This
allows to vary the length of the envelopes B by just accelerating
or decelerating the shaft that carries the die-cutter 35, 35'
between two successive operations by means of electrical-electronic
controls, without the need to change the die-cutter 35, 35' or any
other component or to create storage units of the sheet F.
[0162] If, on the other hand, the die-cutter 35, 35' consists of a
full drum of circumference substantially equal to the length of a
single envelope B, it is possible to operate at constant rotation
speeds thereof.
[0163] An object of the present invention is also a method for
continuously packaging products P, each wrapped in a single
envelope B.
[0164] The method according to the present invention comprises the
steps of:
[0165] feeding a continuous sheet F of packaging material, in
particular paper, on a conveying plane PT, wherein the conveying
plane PT is movable to convey the sheet F along a conveying
direction DT in a sense of forward motion A2 between an entrance
end 12a of the continuous sheet F and an exit end 12b of a
plurality of envelopes B each containing a respective product
P,
[0166] feeding on the continuous sheet F moving forward along the
conveying direction DT a plurality of products P arranged in
succession one after another and at a distance one from
another;
[0167] defining in the sheet F being fed on the conveying plane PT
or moving forward along the conveying direction DT a pair of
longitudinal creases C1, C2 for folding a respective longitudinal
leaf, a first longitudinal leaf F1 that defines the back B2 of the
envelopes B and a second longitudinal leaf F2 that defines the
closing flap B3 of the envelopes B, respectively, in which the
first longitudinal leaf F1 and the second longitudinal leaf F2
define a longitudinal central portion F3 of the sheet F that
defines the front B1 of the envelopes B and on which the products P
are fed arranged in succession one after another and at a distance
one from another;
Wherein, after the step of feeding the sheet F on the conveying
plane PT and before the envelopes B exit from the exit end 12b of
the conveying plane PT, there is at least one step of
[0168] die-cutting at least one of the first longitudinal leaf F1,
or in any case the longitudinal portion of the sheet F that defines
the first longitudinal leaf F1, and the second longitudinal leaf
F2, or in any case the longitudinal portion of the sheet F that
defines the second longitudinal leaf F2, to die-cut in it the back
B2 and/or the profile of the back B2 and the closing flap B3 and/or
the profile of the closing flap B3 of each envelope B,
respectively.
[0169] The step of feeding the sheet F on the conveying plane PT
comprises moving the sheet F forward along a feeding plane PA which
extends below the conveying plane PT, is orthogonal or
substantially orthogonal to the conveying direction DT and is
defined at the entrance end 12a of the conveying plane PT, wherein
the sheet F is fed along the feeding plane PA according to a
feeding direction DA orthogonal or substantially orthogonal to the
conveying plane PT and is deviated by a right angle or
substantially a right angle in the passage from the feeding plane
PA to the conveying plane PT.
[0170] In particular, the at least one die-cutting step is carried
out after the sheet F has been deviated by about 90.degree. to pass
from the feeding plane PA to the conveying plane PT and, even more
specifically, after the first longitudinal crease C1 and the second
longitudinal crease C2 have been defined in it.
[0171] The at least one die-cutting step, therefore, takes place
when the sheet F moves forward along the conveying direction
DT.
[0172] The at least one die-cutting step, moreover, is provided, in
particular, to die-cut the second longitudinal leaf F2, or in any
case the longitudinal portion of the continuous sheet that defines
the second longitudinal leaf F2, to die-cut in it the closing flap
B3 and/or the profile of the closing flap B3 of each envelope
B.
[0173] Such an at least one die-cutting step is carried out, in
particular, to define in the second longitudinal leaf F2 a
plurality of transversal notches I as described above and/or a
plurality of incisions, toothings, perforations for tamper-proofing
aimed at highlighting when the envelopes have been opened.
[0174] There could also be more than one die-cutting step and they
could be carried out simultaneously or in succession after one
another.
[0175] The method according to the present invention also
comprises, after the step of defining in the sheet F the pair of
longitudinal folding creases C1 and C2, even in a different
succession to one another, at least the operative steps of:
[0176] folding the first longitudinal leaf F1 on the longitudinal
central portion F3 of the sheet F so as to at least partially cover
the products P, forming the back B2 of the envelopes B and
obtaining a continuous wrapping, or folding the portion of the
first longitudinal leaf F1 of each longitudinal section of the
sheet F that defines a respective envelope B on the respective
portion of the longitudinal central portion F3 so as to at least
partially cover the respective product P forming the back B2 of the
respective envelope B;
[0177] pressing the first longitudinal leaf F1 folded on the
longitudinal central portion F3 or the portion of the first
longitudinal leaf F1 of each longitudinal section of the sheet F
that defines a respective envelope B folded on the respective
portion of the longitudinal central portion F3, exerting a pressure
on them at at least one transversal strip S', S'' of adhesive or
glue present or in any case applied on the sheet F or on each
longitudinal section of the sheet F that defines a respective
envelope B at at least one segment of at least one of the two
transversal sides of each longitudinal section that defines a
corresponding envelope B;
[0178] transversally cutting the continuous wrapping obtained by
the folding at least the first longitudinal leaf or in any case the
sheet F between two successive products P so as to obtain a
plurality of longitudinal sections that are separated from one
another and each defining a respective envelope B.
[0179] In the method according to the present invention, the at
least one die-cutting step, in particular the at least one
die-cutting step of the second longitudinal leaf F2, is carried out
after the step of folding the first longitudinal leaf F1 on the
longitudinal central portion F3 so as to at least partially cover
the products P and obtain a continuous wrapping and before the step
of transversally cutting such a continuous wrapping between two
successive products P.
[0180] The at least one die-cutting step, in particular the at
least one die-cutting step of the second longitudinal leaf F2, is
carried out separately from the other operative steps or at least
in part simultaneously with one of them.
[0181] For example, the at least one die-cutting step can be
carried out separately and distinctly before the pressing step or
after the pressing step and before the transversal cutting
step.
[0182] Alternatively, the at least one die-cutting step can be
carried out at least in part simultaneously with the pressing step
or with the transversal cutting step.
[0183] After the at least one die-cutting step of the second
longitudinal leaf F2 and after the folding step of the first
longitudinal leaf F1 or in any case of the portion of the first
longitudinal leaf F1 of each longitudinal section of the sheet F
that defines a respective envelope B, there is a step of folding
the second longitudinal leaf F2 thus die-cut on the first
longitudinal leaf F1 or in any case the portion of the second
longitudinal leaf F2 of each longitudinal section of the sheet F
defines a respective envelope B on the corresponding portion of the
first longitudinal leaf F1 already folded.
[0184] The step of folding the second longitudinal leaf F2 that is
already die-cut can, in other words, be carried out before or after
the transversal cutting step; if it is carried out before, then the
entire die-cut second longitudinal leaf F2 is folded on the first
longitudinal leaf F1 that is already folded, whereas if it is
carried out after, on the other hand, the single portions thereof
corresponding to each longitudinal section of the sheet F are
folded on the respective portion of the first longitudinal leaf F1
that is already folded.
[0185] Such a folding step, moreover, can be preceded by a step of
applying, on the second longitudinal leaf F2 or on the portion of
the second longitudinal leaf F2 of each longitudinal section of the
sheet F that defines a respective envelope B, a strip S''' of glue
parallel to the conveying direction DT.
[0186] In a possible alternative embodiment of the method according
to the present invention, there is a further die-cutting step
carried out during the feeding step to die-cut the longitudinal
central portion F3 of the sheet F or in any case the longitudinal
portion of the sheet F that defines the longitudinal central
portion F3 to define a window FS, a hole or other in it, at the
front B1 of each envelope B.
[0187] Such a further die-cutting step can also or alternatively be
provided to die-cut the first longitudinal leaf F1, or in any case
the longitudinal portion of the sheet F that defines it to define
in it the profile of the edge that defines the back B2 of each
envelope B and/or transversal notches and/or perforations, holes,
incisions, toothings or similar, in particular for tamper-proofing.
Such a further die-cutting step could also take place in a
packaging method that does not provide the at least one die-cutting
step for die-cutting the first or the second longitudinal leaf.
[0188] In practice it has been noted how the present invention
achieves the predetermined purposes.
[0189] The machine and the method for packaging according to the
present invention, indeed, allow to carry out the die-cutting that
defines the profile of the free edge of the closing flap of each
envelope directly on the machine itself and during the packaging of
the products in single envelopes, eliminating the need for
dedicated "on line" or "off-line" die-cutting apparatuses and thus
eliminating the installation, management and maintenance costs of
the latter and the bulk occupied by them.
[0190] The machine and the method for packaging according to the
present invention allow to carry out the die-cutting that defines
the profile of the free edge of the closing flap of each envelope
directly on the machine itself and during the packaging of the
products in single envelopes, in particular, after the deviation by
about 90.degree. that the continuous sheet of paper undergoes when
entering while passing from the feeding plane to the conveying
plane. This allows to more safely preserve the integrity of the
continuous sheet of paper--that, in such passage, lacks transversal
notches--and consequently allows, on the one hand, to also use
higher speeds than those currently possible for the same type of
packaging material, in particular paper, and packaging format and,
on the other hand, to use types of packaging material, in
particular paper, even with low grammage and, therefore, of lower
cost, and not usable up to now.
[0191] The machine and the method for packaging according to the
present invention also allow to obtain profiles of the free edge of
the closing flap of the envelopes that copy those of standard
pre-formed envelopes and, consequently, to reduce the dimensions of
the continuous sheet of paper necessary to package them.
[0192] The machine and the method for packaging according to the
present invention also allow to carry out the die-cutting that
defines the profile of the free edge of the closing flap of each
envelope directly on the machine itself and during the packaging of
the products in single envelopes and, in particular, during and
simultaneously to the pressing for closing one or both of the
adjacent transversal sides of two successive envelopes. This allows
to reduce the packaging times, with evident advantages in terms of
production.
[0193] The machine and the method for packaging according to the
present invention also allow to easily manage, for the same
profile, the change in length of the single envelopes. For this
purpose, indeed, it is no longer necessary to replace any
processing unit and, in particular, any die-cutter, being
sufficient to manage the speed of rotation of the die-cutter
outside of each die-cutting operation. The die-cutter itself,
moreover, consists of a drum sector and not a full drum, with a
consequent reduction of the inertias involved and, therefore, the
possibility of being able to make it rotate at a tangential speed
equal to that of forward movement of the continuous sheet of paper
along the conveying plane, without the need to provide buffers for
the storage of the sheet itself upstream and/or downstream of
it.
[0194] The machine and the method for packaging according to the
present invention also allow to carry out the die-cutting that
defines the profile of the free edge of the closing flap of each
envelope directly on the machine itself and during the packaging of
the products in single envelopes and, in particular, just before
the operation of cutting and separating the single envelopes. This
allows eliminating the phasing errors of the cutting operation with
the forward movement of the continuous sheet of paper and,
therefore, to centre the cutting at the separation line of two
successive longitudinal portions of the sheet itself that each
define a respective envelope. Therefore, it is no longer necessary
to provide astride of such a same separation line an auxiliary
compensation portion of the position errors of the transversal cut
with consequent further reduction of the dimensions of the sheet
needed to obtain the same number of envelopes with respect to the
prior art.
[0195] The possible presence of an auxiliary die-cutting unit to
form a window in the front of each envelope allows to use the
machine to carry out operations that are currently carried out with
separate apparatuses.
[0196] The automatic packaging machine for continuously packaging
products each wrapped in a single envelope and the method for
continuously packaging products each wrapped in a single envelope
thus conceived can undergo numerous modifications and variants, all
of which are covered by the invention; moreover, all of the details
can be replaced by technically equivalent elements. In practice,
the materials used, as well as the sizes, can be whatever according
to the technical requirements.
* * * * *