U.S. patent application number 14/396999 was filed with the patent office on 2015-04-23 for device and method for folding foldable blanks.
This patent application is currently assigned to WINKLER + DUNNEBIER GMBH. The applicant listed for this patent is WINKLER + DUNNEBIER GMBH. Invention is credited to Antonius Kloft.
Application Number | 20150111715 14/396999 |
Document ID | / |
Family ID | 48485097 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150111715 |
Kind Code |
A1 |
Kloft; Antonius |
April 23, 2015 |
DEVICE AND METHOD FOR FOLDING FOLDABLE BLANKS
Abstract
A device for folding foldable blanks device includes a conveyor
belt for conveying the blanks and a folding cylinder for receiving
a first region of a blank from the conveyor belt, wherein the
conveyor belt is provided with a plurality of suction openings
which are arranged such that, by means of a vacuum unit assigned
thereto, the suction openings hold a second region of the foldable
unfashioned piece on the conveyor belt at least during folding.
Inventors: |
Kloft; Antonius; (Hahn am
See, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WINKLER + DUNNEBIER GMBH |
Neuwied |
|
DE |
|
|
Assignee: |
WINKLER + DUNNEBIER GMBH
Neuwied
DE
|
Family ID: |
48485097 |
Appl. No.: |
14/396999 |
Filed: |
April 25, 2013 |
PCT Filed: |
April 25, 2013 |
PCT NO: |
PCT/EP2013/001243 |
371 Date: |
October 24, 2014 |
Current U.S.
Class: |
493/450 |
Current CPC
Class: |
B65H 45/12 20130101;
B65H 2406/3223 20130101; B65H 2701/1916 20130101 |
Class at
Publication: |
493/450 |
International
Class: |
B65H 45/12 20060101
B65H045/12 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2012 |
DE |
10 2012 207 126.1 |
Claims
1-7. (canceled)
8. A device for folding foldable blanks, comprising: a conveyor
belt for conveying the blanks; and a folding cylinder for receiving
a first region of one of the a blanks from the conveyor belt said
conveyor belt being provided with a plurality of suction openings
said suction openings being arranged so that, by means of a vacuum
unit assigned to the suction openings, the suction openings hold a
second region of the blank on the conveyor belt at least during
folding.
9. The device of claim 8, wherein the suction openings are arranged
in a plurality of rows which extend transverse to a conveying
direction of the blank.
10. The device of claim 9, wherein one of the rows of suction
openings is directly adjacent to an intended fold of the blank
resting on the suction openings and has a larger number of suction
openings than any of the remaining rows of suction openings.
11. The device of claim 9, wherein the number of suction openings
in each of the rows either decreases in steps or remains constant,
starting from the intended fold of the blank, and counter to the
conveying direction.
12. The device of claim 8, further comprising a folding plate
arranged downstream of the folding cylinder in the conveying
direction.
13. The device of claim 8, further comprising a plurality of
flattening rollers.
14. A method for folding a foldable blank, comprising: conveying
the blank in a conveying direction by means of a conveyor belt;
holding a first region of the blank on the conveyor belt by means
of a suction device; receiving a second region of the blank,
situated in front of the first region in the conveying direction,
by means of a folding cylinder; folding the blank by guiding the
first region further in the conveying direction and below the
second region; and placing the second region on the first region by
causing the folding cylinder to release the second region.
Description
[0001] The invention relates to a device for folding foldable
blanks, in particular envelopes, comprising a conveyor belt for
conveying the blanks and a folding cylinder for receiving a first
region of a blank from the conveyor belt. The invention further
relates to a method for folding a foldable blank using the method
steps.
[0002] In particular in the production of envelopes, blanks are now
folded in a fully automated manner by corresponding systems. In the
process, high demands are placed on the devices, since large-scale
production is required on one hand, and a clean fold at a precise
position is desired on the other.
[0003] WO 99/47348, for example, discloses a system of this type,
which can fold paper blanks transverse to the conveying direction
at high speed. For this purpose, a roller system is provided, which
comprises a conveying roller and a folding roller for receiving the
region, which is to be folded, of the paper blank. In the process,
the folding roller receives the front edge of the paper blank which
is conveyed along the conveying roller. The remaining region of the
paper blank is then guided below the front edge as a result of the
rotary movement of the conveying roller, whereby a fold is formed
transverse to the conveying direction. The paper blank folded thus
can then be processed further in subsequent method steps.
[0004] As the folding processes became ever more automated, there
was a demand for the item to be packaged, i.e. the content, to be
sent, of the envelope, to have already been fed in or to be fed in
during folding of the envelopes. Therefore, once the folding
process is complete, the envelope has not just been folded and has
to be filled in a downstream filling process and then closed, but
the envelope has already been completely filled following the
folding process. Subsequent method steps for filling the envelope
can thus be avoided.
[0005] U.S. Pat. No. 3,593,486 describes a system of this type, in
which the envelope is filled as early as during folding. In this
case too, the system again comprises a roller system having a
conveying roller for the envelope. The front edge of the paper
blank is also raised again in this case, although this time only by
means of an overpressure system in the conveying roller. During
folding, the item to be sent is now inserted by being slid onto the
fold obliquely to the conveying direction. An adjacent roller then
folds the raised bottom flap of the paper blank onto the item and
the front wall of the envelope.
[0006] A particular drawback of this system is the location at
which the item to be packaged is fed in. Since the item to be
packaged is fed in during the folding process, a folding cylinder
has to be omitted, since the available space, which is only
limited, in the system is required for the feed unit. This also
means that only one feed unit is possible, and therefore the
separate feed of for example correspondence and additional
informational flyers is not possible. Targeted feeding of the item
onto or against the fold also leads to the fold being loaded during
the folding process, and this can lead to damage or displacement of
the fold (if the load from the material fed in is uneven).
[0007] Therefore, the problem addressed by the invention is that of
providing a device and a method in which blanks, in particular for
envelopes, both having and not having an item to be packaged can be
cleanly and precisely folded in large-scale production.
[0008] In terms of the device, this problem is solved according to
the invention by the conveyor belt being provided with a plurality
of suction openings which are arranged such that, by means of a
vacuum unit assigned thereto, they hold a second region of the
foldable unfashioned piece on the conveyor belt at least during
folding. In terms of the method, this problem is solved according
to the invention by the following method steps: [0009] conveying
the blank in a conveying direction x by means of a conveyor belt,
[0010] holding a second region of the blank on the conveyor belt by
means of a suction device, [0011] receiving a first region of the
blank, which is in front of the second region in the conveying
direction x, by means of a folding cylinder, [0012] folding the
blank by the second region being guided further in the conveying
direction x and below the first region, [0013] placing the first
region on the second region by the folding cylinder releasing the
first region.
[0014] Advantageous embodiments form the subject matter of the
dependent claims.
[0015] The invention is based on the consideration that the item to
be packaged should preferably be fed in before the blank is folded,
so that the upstream feed unit can be designed and formed
independently of the folding device, so that even a plurality of
additional items can be packaged together in an extremely simple
manner, and also so that the feed unit does not interrupt, impair
or otherwise, for example owing to the required space, affect the
folding process. The item to be packaged and the unfashioned
envelope piece or paper blank can be fed in with precise
positioning in particular when the blank does not perform a
circular movement, but rather is guided horizontally. A paper blank
can be conveyed horizontally in such a manner by means of a
correspondingly arranged conveyor belt.
[0016] In order to prevent the contents from slipping on the paper
blank during the folding process, but in particular to also prevent
the paper blank from slipping on the conveyor belt, and to thus
allow for a particularly clean and precise fold transverse to the
conveying direction, the conveyor belt is provided with a plurality
of suction openings which securely hold the paper blank on the
conveyor belt by means of a vacuum system. The region to be folded
(generally the bottom flap in the case of envelopes) can now be
raised by the folding cylinder independently of the item to be
packaged, and folded over along the fold.
[0017] In order to hold the blank particularly strongly on the
conveyor belt, in an advantageous embodiment the suction openings
are arranged in rows which extend parallel to the fold and thus
transverse to the conveying direction. In this case, in a
particularly advantageous embodiment the row of suction openings
that is directly adjacent to the fold comprises the highest number
of suction holes. The blank is thus held particularly strongly on
the conveyor belt at the precise point where most of the forces act
on the second region of the blank during folding, which forces
could cause the blank to slip.
[0018] However, the trailing regions of the blank, i.e. the regions
that follow when viewed in the conveying direction of the fold, are
not subjected to such great forces, but nevertheless have to be
held firmly and in a slip-proof and rotation-proof manner. For
energy saving reasons, in an advantageous embodiment the number of
suction openings therefore reduces with each row. Therefore, the
number of suction openings becomes smaller or at most remains
constant with each additional row further away from the fold. The
rear regions are thus also adequately held without the need for an
unnecessarily large vacuum system.
[0019] To assist the folding process and for a particularly clean
and precise fold, in a preferred embodiment the device comprises a
folding plate which is arranged downstream of the folding cylinder
in the folding process. Owing to its arrangement, this folding
plate favours uniform placement of the raised first region on the
second region of the blank or on the item to be packaged that is
resting on the second region of the blank.
[0020] For uniform pressing and thus flat resting of the raised
first region, in an advantageous embodiment a plurality of
flattening rollers are provided, which can be arranged upstream
and/or downstream of the folding plate depending on the
configuration. When corresponding adhesive strips are attached to
the first or second region of the blank, said flattening rolls also
promote the bonding of the folded blank.
[0021] The advantages obtained with the invention are in particular
that, by using a conveyor belt having suction openings not only to
supply the blank but also when the blank is folded, folding can
also take place even if there is already an item to be packaged on
the blanks. The item to be packaged thus barely impairs and affects
the folding. The particular arrangement of the hole pattern of the
suction openings also achieves a particularly secure hold of the
blank on the conveyor belt, while the vacuum unit is used in an
energy-efficient manner at the same time.
[0022] An embodiment of the invention will be described in greater
detail with reference to the drawings, in which:
[0023] FIG. 1 shows a device for folding a foldable blank;
[0024] FIG. 2 shows a schematic detail of FIG. 1;
[0025] FIG. 3 is a schematic view of the method steps;
[0026] FIG. 4 shows a conveyor belt having suction openings.
[0027] Like parts are provided with the same reference numerals in
all the drawings.
[0028] An embodiment of a device 1 for folding foldable blanks
(envelopes in the embodiment) is shown in FIG. 1 and a schematic
detail of the device is shown in FIG. 2. In this case, the device 1
comprises a conveyor belt 2, on which unfashioned envelope pieces
provided as blanks 4 to be folded are located and are conveyed in
the conveying direction x. In this case, the conveyor belt 2
conveys the blanks 4 prior to folding, during folding and also
following folding, and then transfers said blanks to an additional
device for further processing of the blank 4, for example for
folding its side flaps. To convey the blanks 4 in a uniform and
controlled manner, the device 1 comprises a driving roller 6 and a
plurality of guide rollers 8, which are arranged such that the
conveyor belt 2 is sufficiently taut and thus flat on one hand, and
such that the blanks 4 can be conveyed horizontally on the other
hand.
[0029] A vacuum unit 10 is provided below the horizontal portion of
the conveyor belt 2 and thus below the portion of the conveyor belt
2 along which the blanks or unfashioned envelope pieces are
conveyed. Said vacuum unit 10 sucks the blanks 4 by means of a
plurality of suction openings 12 on the conveyor belt 2, so that
said blanks are held in a slip-proof manner during conveyance. In
this context, just one vacuum chamber 10 is provided in the present
embodiment, which chamber extends over the short portion in which
the blank 4 has to be held during the folding process. Depending on
the application, however, it is also possible to form the vacuum
unit 10 over the entire conveying path, so that the blank 4 is
constantly held in a slip-proof manner.
[0030] By contrast, a folding cylinder 14 or a vibrator roller is
arranged above the horizontal portion of the conveyor belt 2 and
can receive and raise, from the conveyor belt 2, each unfashioned
envelope piece or blank 4 or part 16 of the blank 4. For this
purpose, the folding cylinder 14 also comprises a vacuum unit and a
plurality of suction openings 18 which are arranged on the
circumferential surface of the folding cylinder 14 and can suck and
thus raise the side, facing away from the conveyor belt 2, of the
first region 16 of the blanks 4. A folding plate 20, which promotes
the folding process, is also arranged above the horizontal portion
of the conveyor belt 2 downstream of the folding cylinder 14 in the
folding process. Downstream of the folding plate 20 in the folding
process, a flattening roller 22 is also arranged, which promotes
clean folding. In an alternative configuration or within the scope
of an additional configuration, however, said flattening roller 22
can also be arranged directly upstream of the folding plate 20 by
means of a second flattening roller.
[0031] The folding process is shown in a schematic view in FIG. 3
in 5 method steps selected by way of example. [0032] (1) In this
case, the blank 4 rests on the conveyor belt 2 and is held in a
slip-proof manner by suction openings 12 in the conveyor belt 2, to
which openings a vacuum is applied. In this context, the suction
openings 12 act only on a second region 24, typically the front
wall and optionally the side flaps, and not on a first region 16,
typically the bottom flap of the blank 4, since said bottom flap is
raised during the subsequent folding process. [0033] (2) Once the
front edge of the bottom flap 16 passes the folding cylinder 14,
said bottom flap is raised by means of suction holes 18, which are
arranged in the circumferential surface of the folding cylinder 14
and to which a vacuum is likewise applied, and guided along the
folding cylinder 14 (anti-clockwise in the point of view shown). In
this method step, the blank 4 is thus held by two independent
vacuum systems, the direction of movement of which is different.
The front wall 24 of the blank 4 is also held on the conveyor belt
2 and moved in the conveying direction x, while the bottom flap 16
is raised and guided along the folding cylinder 14 on a circular
path. [0034] (3) As soon as the whole of the bottom flap 16, which
is to be folded, has been raised, the vacuum in the folding
cylinder is released and the bottom flap 16 is no longer held by
the folding cylinder 14. The front wall of the blank, however, is
still held on the conveyor belt 2 and moved in the conveying
direction x. This continuation of the movement of the front wall 24
now leads to the bottom flap 16 being folded along the bottom fold
26. In this case, a folding plate 20, which is arranged downstream
of the folding cylinder 14 in the folding process, promotes the
placement of the bottom flap 16 onto the front wall 24. In an
alternative configuration of the folding cylinder 14, said cylinder
can actively promote the folding process when a vacuum is applied
and by means of a clockwise rotation. [0035] (4) A flattening
roller 22, which can be arranged downstream of the folding plate 20
in the folding process, provides for clean folding and tight
resting of the bottom flap 16 on the front wall 24. [0036] (5) As
soon as the blank 4 has passed the folding cylinder 14, the folding
plate 20 and the flattening roller 22, the folding of the bottom
flap 16 is complete. In this case, the folded blank 4 is still on
the conveyor belt 2 and can be held in a slip-proof manner by means
of a plurality of suction openings 12 to which a vacuum is applied.
The folded blank 4 can now be transferred to a downstream device
for further processing, for example further folding of or printing
on the bottom flap 16.
[0037] It is also possible for an adhesive or bonding strip to be
attached to the blank 4 in a preceding step by means of a bonding
unit, so that folding bonds the front wall 24 or side flaps to the
bottom flap 16. As already mentioned, it is likewise provided that
a plurality of additional blanks, for example an item 28 to be
packaged that is covered or packaged by the folding of the bottom
flap 16, is optionally located on the front wall 24 of the blank 4.
In this process, these items 28 to be packaged or enclosed are held
on the region of the front wall 24 of the blank 4 by means of a top
belt 30, which runs at the same speed as the conveyor belt 2 formed
as a suction belt. For this reason, in the present configuration
the folding cylinder 14 also comprises two individual, narrow
folding rollers which are arranged at a distance from one another
on a common rotary shaft 32. The top belt 30 projects into said gap
between the two folding rollers, so that the item 28 to be packaged
can be held on the blank 4 until the folding process.
[0038] FIG. 4 shows one embodiment of a conveyor belt 2 having an
exemplary hole pattern of suction openings 12. In this case, two
unfashioned envelope pieces 4 are shown on the suction belt 2,
which pieces are held on the conveyor belt 2 in a slide-proof
manner by means of the suction openings 12 and are moved in the
conveying direction x together with and/or by the conveyor belt 2.
In this context, the suction openings 12 on the conveyor belt 2 are
not uniformly distributed over the conveyor belt 2, but rather are
arranged in specific places where particularly good adhesion of the
unfashioned envelope piece 4 is desired during folding.
[0039] It has been found in this context that good adhesion of the
blank 4, which is to be folded, to the conveyor belt 2 is desirable
directly along the fold 26 and on the side thereof with the front
wall 24. For this reason, in the present case of the transverse
folding of the bottom flap 16 of the unfashioned envelope piece, a
particularly high number of suction openings 12 are provided in a
portion b.sub.1 of the front wall 24 that is adjacent to the fold
26, which openings extend substantially over the entire width of
the conveyor belt 2. In the present case, the portions b.sub.1,
b.sub.2 . . . b.sub.n are selected such that each row of suction
openings 12 is in its own portion b.sub.1, b.sub.2 . . . b.sub.n.
However, in the subsequent portions b.sub.2, b.sub.3 . . . b.sub.n
of the front wall 24, which are further away from the fold 26, a
lower density of suction openings 12 is provided. In the present
embodiment, at first this density of suction openings 12 decreases
constantly the further away the region is from the fold 26 until
said density then remains constant, before no more suction holes 12
are provided. In this case, the number of portions b.sub.1, b.sub.2
. . . b.sub.n in which suction openings 12 are provided is adapted
to the size of the blanks 4 to be folded, and preferably extends at
least over the entire length of the front wall 24. The number of
portions b.sub.1, b.sub.2 . . . b.sub.n and also the number of
suction openings 12 or the width over which the suction holes 12
extend transverse to the conveying direction x in the region of the
fold 6 are thus adapted to the largest format to be folded of a
blank 4. As a result, it is possible to process any given formats
of blanks 4 without changing the conveyor belt 2 or shutting down
the device 1.
[0040] The result of this specific hole pattern and the particular
distribution of the suction openings 12 is that the bottom flap 16
of the unfashioned envelope piece 4 can be raised in a particularly
simple manner, since no suction openings 12 are provided in this
region. The folding itself can, however, be carried out
particularly precisely, since the front wall 24 of the unfashioned
envelope piece 4 is held on the conveyor belt 2, in the region of
the fold 26, by means of a plurality of suction openings 12 along
the fold 26. Since the remaining region of the front wall 24 is
also intended to be held on the conveyor belt 2 in a slide-proof
and in particular also a rotation-proof manner, although, as has
been shown, it is not necessary to apply such high pressures here
as are desired along the fold 26, there is no need to distribute
the suction openings 12 along the entire width of the suction belt
2. This is also desirable in particular for energy saving reasons.
The extension of the resultant triangular or T-shape of the hole
pattern of the suction openings 12 both along the conveyor belt and
transverse thereto prevents rotation of the blank 4, which is to be
folded, in a particularly effective manner.
LIST OF REFERENCE NUMERALS
[0041] 1. Folding device [0042] 2. Conveyor belt [0043] 4. Blank
[0044] 6. Driving roller [0045] 8. Deflection roller [0046] 10.
Vacuum unit [0047] 12. Suction openings [0048] 14. Folding cylinder
[0049] 16. First region of the blank [0050] 18. Suction holes
[0051] 20. Folding plate [0052] 22. Flattening roller [0053] 24.
Second region of the blank [0054] 26. Fold [0055] 28. Item [0056]
30. Top belt [0057] 32. Rotary shaft [0058] x Conveying direction
[0059] b.sub.1, b.sub.2 . . . b.sub.n Portions of the blank
* * * * *