U.S. patent application number 14/892048 was filed with the patent office on 2016-04-21 for device and method for unfolding packaging carton sleeves.
The applicant listed for this patent is SIG TECHNOLOGY AG. Invention is credited to Jurgen BLUMEL, Thomas VETTEN, Bernd VON BIRGELEN, Immo WEIDNER, Franco ZAGAR.
Application Number | 20160107779 14/892048 |
Document ID | / |
Family ID | 50346026 |
Filed Date | 2016-04-21 |
United States Patent
Application |
20160107779 |
Kind Code |
A1 |
WEIDNER; Immo ; et
al. |
April 21, 2016 |
Device and Method for Unfolding Packaging Carton Sleeves
Abstract
A device for unfolding packaging carton sleeves having a
mechanism for providing the flat carton sleeves, a transfer unit,
which can be rotated about a rotational axis, having at least one
suction member for adhering to the carton sleeves and for
transferring the carton sleeves to a conveyor belt, wherein the
suction member is at a distance from the rotational axis. The
conveyor belt includes at least one pocket for receiving the carton
sleeves. The distance between the suction member and the rotational
axis is constant and consequently the carton sleeves are channelled
along a circular track.
Inventors: |
WEIDNER; Immo; (Zetel,
DE) ; BLUMEL; Jurgen; (Linnich, DE) ; VETTEN;
Thomas; (Dusseldorf, DE) ; ZAGAR; Franco;
(Grefrath, DE) ; VON BIRGELEN; Bernd; (Waldfeucht,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIG TECHNOLOGY AG |
Neuthausen am Rheinfall |
|
CH |
|
|
Family ID: |
50346026 |
Appl. No.: |
14/892048 |
Filed: |
March 25, 2014 |
PCT Filed: |
March 25, 2014 |
PCT NO: |
PCT/EP2014/055922 |
371 Date: |
November 18, 2015 |
Current U.S.
Class: |
493/315 |
Current CPC
Class: |
B65B 43/52 20130101;
B65B 43/285 20130101; B65B 43/185 20130101; B65B 43/325 20130101;
B65B 43/205 20130101 |
International
Class: |
B65B 43/28 20060101
B65B043/28; B65B 43/20 20060101 B65B043/20; B65B 43/32 20060101
B65B043/32; B65B 43/18 20060101 B65B043/18; B65B 43/52 20060101
B65B043/52 |
Foreign Application Data
Date |
Code |
Application Number |
May 23, 2013 |
DE |
10 2013 105 260.6 |
Claims
1. A device for unfolding packaging carton sleeves comprising: a
mechanism for providing flat carton sleeves, a transfer unit, which
can be rotated about a rotational axis and which has a plurality of
suction members for adhering to the carton sleeves by suction, and
for transferring the carton sleeves to a conveyor belt, wherein the
suction members are at a distance from the rotational axis, wherein
the conveyor belt comprises at least one pocket for receiving the
carton sleeves, wherein the distance between the suction members
and the rotational axis is constant and consequently the carton
sleeves are channelled along a circular track, and wherein all of
the suction members are arranged at the same distance from the
rotational axis of the transfer unit.
2. The device according to claim 1, wherein the conveyor belt runs
in a straight line in the region of the device.
3. The device according to claim 1, wherein the conveyor belt runs
in a curved direction in the region of the device.
4. The device according to claim 1, wherein the mechanism has at
least one movably mounted finger with a lug for separating the flat
carton sleeves.
5. The device according to claim 1, wherein the mechanism has a
hopper for channelling the carton sleeves, wherein a central plane
of which has an offset in relation to the rotational axis of the
transfer unit.
6. (canceled)
7. The device according to claim 1, wherein the suction members are
inclined at an angle to a tangential plane touching the circular
track.
8. The device according to claim 1, wherein the pockets have two
rigid side walls.
9. The device according to claim 1, wherein the pockets have a
rigid back wall.
10. The device according to claim 8, wherein the side walls of the
pockets protrude vertically from the back wall and/or the conveyor
belt.
11. The device according to claim 1, wherein the pockets have at
least one spring member for clamping the carton sleeve into the
pocket.
12. The device according to claim 11, wherein an end of the spring
member is configured as hook-shaped.
13. The device according to claim 1, wherein a minimum distance
between the circular track of the suction members and a back wall
of the pocket is shorter than a length of the side walls of the
pockets.
14. A method for unfolding packaging carton sleeves comprising the
following steps: a) provision of carton sleeves by a mechanism, b)
adhesion to the carton sleeves by suction and advancement of said
carton sleeves by a transfer unit rotating about a rotational axis
having a plurality of suction members, and c) unfolding the carton
sleeves by inserting said carton sleeves into a pocket attached to
a conveyor belt, wherein the transfer unit channels the carton
sleeves along a circular track at a constant distance between the
suction members and the rotational axis wherein the carton sleeves
are unfolded solely as a result of the effect of the suction
members and the pocket on the carton sleeve.
15. The method according to claim 14, wherein the transfer unit
rotates at an angular velocity greater than zero.
16. The method according to claim 14, wherein the transfer unit
rotates at a constant angular velocity.
17. The method according to claim 14, wherein the conveyor belt
moves at a speed greater than zero.
18. The method according to claim 14, wherein the conveyor belt
moves at a constant speed.
19. The method according to claim 14, wherein the carton sleeves
are separated in the mechanism by a movably mounted finger, which
has a travel in the range of between 1 cm and 4 cm.
20. The method according to claim 14, wherein the suction members
establish a negative pressure in an angular range of
350.degree.<.phi.<10.degree..
21. The method according to claim 14, wherein the suction members
dissipate the negative pressure in an angular range of
125.degree.<.phi.<145.degree..
22. The method according to claim 14, wherein the suction members
adhere to the carton sleeves by suction at a distance from the
centre thereof, which is in the region of between 0 cm and 6 cm.
Description
[0001] The invention relates to a device for unfolding packaging
carton sleeves having a mechanism for providing the flat carton
sleeves, a transfer unit, which can be rotated about a rotational
axis and which has at least one suction member for adhering to the
carton sleeves by suction, wherein the suction member is at a
distance from the rotational axis, and a conveyor belt with at
least one pocket for receiving the carton sleeves.
[0002] The invention also relates to a method for unfolding
packaging carton sleeves comprising the following steps: provision
of the carton sleeves by a mechanism, adhesion to the carton
sleeves by suction and advancement of said carton sleeves by a
transfer unit rotating about a rotational axis having at least one
suction member, and unfolding of the carton sleeves by inserting
said carton sleeves into a pocket attached to a conveyor belt.
[0003] Numerous devices and methods are known in the field of
packaging technology that can be used to unfold flat carton sleeves
so that said sleeves can then be filled with their respective
contents. Complex unfolding devices are often required here, which
pull the flat carton sleeves apart from both sides in order to
bring them into their unfolded form.
[0004] An unfolding device of this type is known from EP 0 112 605
A2. Suction members adhere to the flat carton sleeves by suction
from both sides. The opposing suction members are then moved apart
from each other and consequently the opposing sides of the carton
sleeve are pulled apart and the carton sleeve is unfolded. The
solution described in EP 0 112 605 A2 has the disadvantage that the
design of the unfolding machine is highly complex since suction
members are intended to adhere to the carton sleeve by suction from
both sides, which suction members can be moved towards and away
from each other.
[0005] A further option for unfolding flat carton sleeves is known
from WO 96/23655 A1. In this folding device, the carton sleeves are
delivered into pockets on a conveyor in a flat state. A rotatable
arm with a suction member is attached to each pocket, which is
intended to unfold the carton sleeve from the flat state into the
tubular state. This unfolding device also has the disadvantage of a
complex design, since a rotatable arm with a suction element has to
be provided at each pocket.
[0006] Separate unfolding devices can be dispensed with, however,
if a relative speed, which occurs, for example, when transferring
carton sleeves from a first station to a second station of a
filling line, is used to unfold the carton sleeves. In other words,
the carton sleeve `abuts` a component part of the second station in
the line whilst said sleeve is still being fed from the first
station in the line, which conveys the sleeve further, and is
folded in this manner.
[0007] A device and method of this type for folding, filling and
sealing cartons is known from U.S. Pat. No. 3,060,654. The carton
sleeves are unfolded by a rotating unit, which withdraws the flat
cartons from a magazine and transfers them to a conveyor belt. This
step is illustrated in particular in FIGS. 15a to 15f. The carton
sleeves are unfolded upon transfer from the rotating unit to the
conveyor belt and clamped between a pair of L-shaped lugs which are
attached to the conveyor belt. One leg of the L-shaped lug is
attached to the conveyor belt; the other leg extends beyond the
conveyor belt and is intended to restrain the carton at the side. A
hook is provided at one end of the protruding leg, which is
intended to hold the carton sleeve in its position between both
lugs. The rotating unit has arms with suction heads, which, in
addition to a rotational movement, also perform a radial movement
in the direction of the conveyor belt in order to transfer the
carton sleeves to the conveyor belt. Insertion of the carton
sleeves between both L-shaped lugs is made possible by inserting
the carton sleeves at a point where the conveyor belt runs in a
curved line and consequently the protruding legs of the L-shaped
lug do not run parallel, but are spread apart. The conveyor belt
travels in a straight line again after the carton sleeves have been
inserted, wherein the spread protruding legs of the lugs return to
their usual position and the carton sleeve is clamped between the
protruding legs of the lugs that now run parallel.
[0008] The solution disclosed in U.S. Pat. No. 3,060,654 firstly
has the disadvantage that it is extremely complex in terms of
design. The reason for this is that the arms of the rotating
mechanism are intended to perform not only a rotational movement,
but also a movement in a radial direction in order to draw the
carton sleeves from the magazine and channel them towards the
conveyor belt. A further disadvantage is the lack of variability of
the configuration. Since the carton sleeves are intended to be
clamped between a pair of L-shaped lugs in the manner described
above, the carton sleeves have to be inserted into the lugs at a
point where the conveyor belt moves from a curved course to a
straight course. Provision is not made, however, for inserting and
fixing the carton sleeves upstream or downstream of this
transitional region.
[0009] The invention is therefore based on the problem of refining
and developing the device referred to at the start and presented in
detail above, as well as the method also referred to at the start
and presented in detail above, such that reliable unfolding and
transfer of the carton sleeves to the conveyor belt is possible
even with a simple design and a simple procedure.
[0010] This problem is solved in a device according to the preamble
of claim 1 in that the distance between the suction member and the
rotational axis is constant and consequently the carton sleeves are
channelled along a circular track.
[0011] One aspect of the present invention is that suction members
and thus also the carton sleeves to which the suction members
adhere by suction are guided or channelled along a circular track.
As a result of this geometrically simple guiding of the suction
members and the carton sleeves, the transfer unit can be designed
in a particularly uncomplicated and cost-effective way. For
example, the transfer unit may have a cylindrical drum as the main
component. More particularly, it is not necessary to mount the
suction members so that they are moveable in a radial direction.
This facilitates the mounting and/or attachment of the suction
members to the transfer unit considerably. Supplying the suction
members with negative pressure is also facilitated as a result of
the unchanging position of the suction members. Finally, the
transfer unit in a device according to the invention is
characterised by particularly strong robustness since moving parts
can largely be dispensed with. The omission of moving parts also
has advantages in terms of (food) hygiene since the lubrication of
said parts is not applicable.
[0012] Provision is made according to one embodiment of the
invention that the conveyor belt runs in a straight line in the
region of the device. Insertion of the carton sleeves into the
pockets attached to the conveyor belt is facilitated by the
conveyor belt running in a straight line as the pockets are located
sufficiently close to the transfer unit for a longer section than
when the belt runs in a curved line. In addition, there are no
centrifugal forces when the belt runs in a straight line which is
particularly advantageous at high operating speeds. However, when
the conveyor belt leaves the region of the device, it is no longer
necessary for the conveyor belt to run in a straight line; the
conveyor belt can also be diverted in this region. Alternatively,
provision can be made for the conveyor belt to run in a curved
direction in the region of the device. More particularly, the
conveyor belt may run along a circular track in the region of the
device. The arrangement of the device in a curved or circular
section of the conveyor belt has the advantage that those regions
into which the conveyor belt is diverted can also be used. This
makes a particularly compact design of a system for unfolding,
filling and sealing carton sleeves possible.
[0013] A further design of the invention makes provision that the
mechanism has at least one movably mounted finger with a lug for
separating the flat carton sleeves. The height of said lug
preferably corresponds to the height of a flat folded carton. The
finger can be moved forwards and backwards. This linear movement in
a longitudinal direction can be intersected by a movement in a
transverse direction and consequently overall, the finger moves
along an approximately oval trajectory. This design means that that
the finger engages with precisely one carton sleeve in each
movement cycle with the lug and pushes said carton sleeve away from
the stack. The finger can have a precisely defined travel and
consequently the carton sleeve removed from the stack can be
advanced into a desired position where it can be adhered by suction
by the suction members. The place where the suction members engage
with the carton sleeves can be changed by varying the travel. For
example, the travel can be in the region of between 1 cm and 4 cm,
more particularly between 2 cm and 3 cm.
[0014] Provision is made according to a further teaching of the
invention that the mechanism has a hopper for channelling the
carton sleeves, the central plane of which has an offset in
relation to the rotational axis of the transfer unit. The length of
the offset may be in the region of between 1 cm and 6 cm, for
example, more particularly between 2 cm and 4 cm. The offset means
that the suction members do not adhere to the carton sleeves by
suction centrally, but on their edge regions. This facilitates the
insertion of the carton sleeves into the pockets since the carton
sleeves protrude particularly far from the suction members when
they are adhered by suction on the edge regions thereof.
[0015] Provision is made in a further embodiment of the invention
that all suction members are arranged at the same distance from the
rotational axis of the transfer unit. The transfer unit may have
more than one suction member. If several suction members are
present on the transfer unit, it is advantageous to arrange all
suction members at the same radial distance from the rotational
axis of the transfer unit in order to be able to adhere to the
carton sleeves by suction reliably. The suction members may be
arranged in a row such that each carton sleeve is adhered to by
suction by a plurality of suction members at the same time. A
plurality of rows of suction members may also be provided on the
transfer unit. In this manner, a plurality of carton sleeves can be
adhered to by suction and unfolded with each rotation of the
transfer unit. In a preferred embodiment, the rows of suction
members are uniformly arranged over the area of the transfer unit
at identical distances from each other.
[0016] Provision is made according to a further embodiment of the
invention that the suction members are inclined at an angle to a
tangential plane touching the circular track. The angle may be in
the region of between 1.degree. and 10.degree., for example, more
particularly between 3.degree. and 6.degree.. Preferably the
suction members are inclined towards the rotational direction of
the transfer unit. This inclination has the advantage that the
suction members do not remain hanging on the carton sleeves stored
in the magazine. This risk exists due to the fact that the
circumferential edges of non-inclined suction members lie in a
tangential plane and consequently the foremost and very back point
of a non-inclined suction member seen in the direction of rotation
are spaced at a greater radial distance from the rotational axis
than the centre of the suction members, which lies precisely on the
circular track along which the suction members are guided. It can
be achieved in particular by inclining the suction members that the
foremost point of the suction element seen from the direction
rotation again lies within the circular track along which the
suction members are guided. The secondary effects of reducing the
risk of collision, the suction members can be attached to the
carton sleeves better as a result of the inclination.
Alternatively, or in addition to the inclination of the suction
members, the magazine which contains the carton sleeves may also be
inclined at an appropriate angle.
[0017] Provision is made in a further embodiment of the invention
that the pockets have two rigid side walls. A rigid back wall can
also be provided. A rigid wall is understood as being a wall, which
is resistant to bending and more particularly, cannot be tilted or
folded down. Rigid side walls offer a better stop point for the
carton sleeves than flexible or expandable side walls, which
facilitates the unfolding of the carton sleeves. A rigid back wall
provides a good attachment option for the side walls.
[0018] It is further suggested in relation to said embodiments that
the side walls of the pockets protrude vertically from the back
wall and/or the conveyor belt. The unfolding of the carton sleeves
is supported by the vertical line of the side walls as the carton
sleeves are also intended to be at a 90.degree. angle in the
unfolded state.
[0019] A further teaching of the invention makes the provision that
the pockets have at least one spring member for clamping the carton
sleeve in a pocket. The flexible spring member allows particularly
reliable securing of the carton sleeve inside the pocket. The
spring member can be pushed back by the carton sleeve or bent to
the side in order to insert a carton sleeve into the pockets.
Particularly in the case of rigid pockets, the spring member
ensures the secure retention of the carton sleeves as rigid pockets
themselves do not have a strong clamping effect. In rigid pockets
without a spring member, the clamping effect therefore has to be
applied solely through the elasticity of the carton sleeve which
has proven less reliable than the use of spring members, especially
at high operating speeds.
[0020] It is further suggested in relation to this teaching that
the end of the spring member is configured in the shape of a hook.
The hook shape enables particularly good engagement behind the
carton sleeves and reliable retention inside the pocket.
[0021] Provision is made in a further embodiment of the invention
that the minimum distance between the circular track of the suction
members and the back wall of the pocket is shorter than the length
of the side walls of the pockets. This arrangement means that the
suction members are directed very close to the side walls of a
pocket and even `dip into` a pocket in the region between both side
walls. This ensures complete unfolding of the carton sleeves as
said sleeves are pressed deep into the pockets and the forces
required for unfolding are introduced to the carton sleeves solely
by the suction members and the pocket. The depth to which the
suction members `dip into` the pockets may be in the region of
between 1 mm and 10 mm depending on the carton sleeve format.
[0022] The problem described above is solved in a method according
to the preamble of claim 14 in that the transfer unit channels the
carton sleeves along a circular track at a constant distance
between the suction members and the rotational axis.
[0023] As has already been explained in connection with the device
according to the invention, guiding or channeling the carton
sleeves along a circular track has the advantage of being a
particularly simple procedure. More particularly there is no need
for the carton sleeves to be moved in a radial direction.
[0024] It is suggested according to an embodiment of the method
that the transfer unit rotates at an angular velocity that is
always greater than zero. The transfer unit should therefore not be
stopped at any time as would be the case in intermittent operation.
The angular velocity may fluctuate around an average value, for
example, wherein the characteristics of the angular velocity are
repeated in the same manner for each carton sleeve. A cyclical
variation of the angular velocity enables optimisation of the
insertion of the carton sleeves into the pockets. The transfer unit
can also rotate at a constant angular velocity. A constant angular
velocity has the advantage of a particularly efficient process.
More particularly, no additional energy needs to be used to speed
up and slow down the transfer unit. A constant angular velocity
also has a positive effect on the useful life of the machine,
whereas operation at variable angular velocity or even intermittent
operation generally shortens useful life.
[0025] Provision is made in a further embodiment of the method that
the conveyor belt moves at a speed which is always greater than
zero. As has already been stated in respect of the angular velocity
of the transfer unit, the conveyor belt should not be stopped at
any time either. However, a cyclical variation of the speed, for
example a fluctuation around an average value, is possible. In
order to ensure synchronisation between transfer unit and conveyor
belt, the characteristics of the speed must also be repeated here
in the same manner for each carton sleeve. The conveyor belt can
also move at a constant speed. Both the amount and the direction of
speed of the conveyor belt may be constant. Preferably, the speed
of the conveyor belt corresponds more or less to the track speed at
which the suction members are guided along the circular track. In
the event of a cyclical variation of the angular velocity of the
transfer unit and the speed of the conveyor belt, said equivalence
should, however, be observed for the average speeds and more
particularly for speeds at the point of transfer of the carton
sleeves. In this manner a synchronous run can be achieved between
transfer unit and conveyor belt and it can be ensured that the
carton sleeves to which the suction members adhere by suction and
the pockets assigned to said sleeves are brought together at
precisely the same time. The unfolding of the carton sleeves is
successful nevertheless since the front edge of the carton sleeve
is at a greater radial distance from the rotational axis of the
transfer unit than the suction members and therefore also has a
higher track speed than the suction members and the pockets.
[0026] It is suggested in a further embodiment of the method that
the carton sleeves are separated in the mechanism by a movably
mounted finger, which has a travel in the range of between 1 cm and
4 cm. The travel in the direction of a carton sleeve corresponds to
the distance which an unstacked carton sleeve is advanced. The
engagement position of the suction members in relation to the
carton sleeves can be changed by varying the travel.
[0027] It is suggested according to one development of the method
that the suction members establish a negative pressure in an
angular range of 350.degree.<.phi.<10.degree.. Provision can
be made in particular that the suction members build up negative
pressure in an angular range of approx. .phi.=0.degree.. The angle
of rotation .phi. starts at 0.degree. in the region of the magazine
and increases during the course of rotation of the transfer unit.
Negative pressure can therefore be built up to 10.degree. prior to
reaching the magazine. In the region of the minimal distance
between suction members and conveyor belt, the angle of rotation is
preferably approx. 180.degree.. Depending on the arrangement of
magazine and conveyor belt, the angle of rotation in the region of
the conveyor belt may have other values and for example, be in the
region of between .phi.=120.degree. and .phi.=270.degree.. Negative
pressure should preferably be established shortly before reaching
the magazine by extracting air by suction.
[0028] Provision is made in a further embodiment of the method that
the suction members dissipate the negative pressure in an angular
range of 125.degree.<.phi.<145.degree.. Provision can be made
in particular that the suction members dissipate the negative
pressure again in an angular range of approx. .phi.=135.degree..
The negative pressure should be dissipated in order to release the
carton sleeve. This occurs, for example, by ending the suction
process. The negative pressure should be dissipated after the
carton sleeve has contact with the pocket, however, before the
suction members have reached their minimum distance from the
conveyor belt. In an arrangement of the conveyor belt in the region
of .phi.=180.degree., the negative pressure should therefore be
dissipated again in the region of between 125.degree. (i.e.
55.degree. prior to reaching the minimum distance from the conveyor
belt) and 145.degree. (i.e. 35.degree. prior to reaching the
minimum distance from the conveyor belt). In an arrangement of the
conveyor belt, which differs from the 180.degree. position, a
different rotational angular range is produced in a corresponding
manner for dissipating the negative pressure.
[0029] Finally, it is suggested that the suction members adhere to
the carton sleeves by suction at a distance from their centre,
which is in the range between 0 cm and 6 cm, in particular between
1 cm and 3 cm. The distance to the centre may be between 10% and
40% of the width of the carton sleeves. As a result of the
eccentric adhesion to the carton sleeves by suction, the front edge
of the carton sleeve is clearly further away from the suction
members than the back edge. This facilitates a sufficiently deep
insertion of the carton sleeves into the pockets.
[0030] The invention is explained in more detail below using a
drawing which shows only one preferred embodiment. In the
drawing:
[0031] FIG. 1A shows a blank for folding a carton sleeve known from
the prior art,
[0032] FIG. 1B shows a carton sleeve in a flat folded state known
from the prior art, which is formed from the blank shown in FIG.
1A,
[0033] FIG. 1C shows the carton sleeve from FIG. 1B in an unfolded
state,
[0034] FIG. 2 shows a top view of a device according to the
invention for unfolding carton sleeves, and
[0035] FIG. 3 shows a system known from the prior art for filling
packagings with foodstuffs.
[0036] FIG. 1A shows a blank 1 known from the prior art from which
a carton sleeve can be formed. The blank 1 may comprise several
layers of different materials, for example, paper, cardboard,
plastic or metal, more particularly aluminium. The blank 1 has a
plurality of folding lines 2 which are intended to facilitate the
folding of blank 1 and divide the blank 1 into several panels. The
blank 1 can be divided into a first side panel 3, a second side
panel 4, a front panel 5, a rear panel 6, a sealing panel 7, four
base panels 8 and four gable panels 9. A carton sleeve can be
formed from the blank 1 by folding the blank 1 such that the
sealing panel 7 can be attached to the front panel 5, more
particularly fused.
[0037] FIG. 1B shows a carton sleeve 10 in a flat folded state
known from the prior art. The features already described in
connection with FIG. 1A are provided with corresponding reference
signs in FIG. 1B. The carton sleeve 10 is formed from the blank 1
shown in FIG. 1A. The blank 1 has been folded for this purpose such
that the sealing panel 7 and the front panel 5 are overlapping and
consequently both panels can be fused together flat. This results
in a longitudinal seam 11. The carton sleeve 10 is shown in a flat
folded state in FIG. 1B. In said state, a side panel 4 (hidden in
FIG. 1B) lies underneath the front panel 5 whereas the other side
panel 3 lies on top of the rear panel 6 (hidden in FIG. 1B). A
plurality of carton sleeves 10 can be stacked in the flat folded
state in a particularly space saving manner. The carton sleeves 10
are therefore often stacked at the place where they are produced
and transported stack by stack to the place where they are filled.
The carton sleeves are not unstacked and unfolded in order to be
filled with content, for example foodstuffs, until they arrive
here.
[0038] FIG. 1C shows the carton sleeve 10 from FIG. 1B in an
unfolded state. Here, the features already described in connection
with FIG. 1A or FIG. 1B are provided with corresponding reference
signs. The unfolded state is understood as a configuration where an
angle of approx. 90.degree. is formed between both respectively
adjacent panels 3, 4, 5, 6, and consequently the carton sleeve 10
has a square or rectangular cross-section depending on the shape of
said panels. Accordingly, the opposite side panels, 3, 4, are
arranged parallel to each other. The same applies to the front
panel 5 and the rear panel 6.
[0039] The carton sleeve 10 used may have different dimensions
(`formats`). The width of the side panels 3, 4 may be in the region
of between 30 mm and 80 mm. The width of the front panel 5 and the
rear panel 6 may be in the region of between 40 mm and 120 mm. Flat
folded carton sleeves 10 therefore have a width in the region of
between 70 mm (30 mm+40 mm) and 200 mm (80 mm+120 mm). Finally, the
height of the side panels 3, 4 and the front and rear panels 5, 6
may be in the region of between 50 mm and 250 mm. For example, a
filled and sealed carton sleeve with a filling volume of 80 ml will
have external dimensions of 47 mm.times.32.5 mm 55 mm. Accordingly,
a carton with a filling volume of 2000 ml will have external
dimensions of 114 mm.times.74 mm.times.245 mm.
[0040] FIG. 2 shows a top view of a device 12 according to the
invention for unfolding carton sleeves 10. The device 12 comprises
a mechanism 13 for providing, in particular for separating flat
carton sleeves 10, a transfer unit 14 and a conveyor belt 15.
[0041] The mechanism 13, which is also described as `magazine`, has
a housing 16 with a hopper 17, into which a stack of flat carton
sleeves 10 can be placed. The hopper 17 has a central plane 18,
which runs centrally through the carton sleeves 10 placed into said
hopper 17. As shown in FIG. 2, the central plane 18 may be aligned
vertically in relation to the conveyor belt 15. Alternatively, the
central plane 18 may also be inclined in relation to said vertical.
The mechanism 13 also has a plurality of fingers 19 arranged in a
row one behind the other, each of which has a lug 20. The height of
the lug 20 more or less corresponds to the height of a flat folded
carton sleeve 10. The fingers 19 perform a cyclical movement to
unstack the carton sleeves 10, the travel 21 of which movement is
shown by an arrow in FIG. 2. The backwards and forwards movement of
the fingers 19 cause the fingers 19 to push with their lugs 20 a
carton sleeve 10 out of the mechanism 13 in each movement cycle
through an opening 22 from where said carton sleeves can be
transferred to the transfer unit 14. The remaining carton sleeves
10 are fed constantly by a force F directed towards the fingers 19
and consequently continuous unstacking and separation of the carton
sleeves 10 is ensured.
[0042] The transfer unit 14 comprises a drum 23 onto which a
plurality of suction members 24 are attached. The drum 23 shown in
FIG. 2 and preferred in this respect has a cylindrical shape and
thus a circular cross-sectional area. The four rows of suction
members 24 are arranged on a circular track 25 at a constant
distance 26 or radius respectively, wherein the circular track 25
runs through the central points of the suction members 24. The
suction members 24 are fixed in position and consequently all
suction members 24 are always at the same, constant distance from a
rotational axis 27 about which the drum 23 rotates at an angular
velocity w and an angle of rotation cp. The mechanism 13 and the
transfer unit 14 are arranged such that an offset 28 is created
between the rotational axis 27 of the transfer unit 14 and the
central plane 18 of the mechanism 13. The travel 21 of the fingers
19 and the offset 28 causes the suction members 24 not to adhere to
the carton sleeves 10 by suction centrally, but on the edges
thereof.
[0043] The suction members 24 may be charged with negative pressure
via cables (not shown in FIG. 2) in order to adhere to the carton
sleeves 10 by suction in the region of the mechanism 13 (at an
approx. angle of rotation of .phi.=0.degree.) and during the
further rotation of the drum 23 transfer said carton sleeves to the
conveyor belt 15 (at an approx. angle of rotation of
.phi.=180.degree.). The suction members 24 are preferably slightly
inclined and consequently the edges of the suction members 24 lie
on a plane 29, which is inclined at an angle a in relation to the
tangential plane 30 of the circular track 25. In this manner the
suction members 24 are inclined slightly towards the direction of
rotation of the drum 23 and are in a better position to adhere to
the carton sleeves 10 by suction.
[0044] The conveyor belt 15 runs in a straight line in the section
shown in FIG. 2 and has a speed v. The conveyor belt 15 may be a
belt or a chain. Several pockets 31 are attached to the conveyor
belt 15 which serve to receive the carton sleeves 10. The pockets
31 comprise a back wall 32 and two side walls 33. The back wall 32
runs parallel to the conveyor belt 15 and is connected thereto.
Both side walls 33 protrude vertically from the back wall 32; they
are therefore arranged parallel to one another. The rear wall 32
and both side walls 33 are made of metal and have no hinges or
similar and consequently a rigid pocket 31 is involved here. The
pockets 31 have two spring members 34, wherein a spring member 34
is arranged preferably on each side wall 33. The spring members 34
are made of an elastic material, for example spring steel or
flexible plastic, and have a protruding end 35 which is configured
in the shape of a hook. The hook shape allows the spring members 34
to retain or firmly clamp the carton sleeves 10 in place in the
pockets 31.
[0045] The pockets 31 are arranged at a constant distance from each
other, which is also described as `pass`. Said distance 36
corresponds approximately to the length of an arc segment which
runs along the circular track 25 between two adjacent suction
members; in the case of four suction members 24, the distance 36
corresponds to approx. one quarter of the circumference of the
circular track 25. The transfer unit 14 is arranged opposite the
conveyor belt 15 such that there is a minimum distance 37 between
the circular track 25 of the suction members 24 and the back wall
32 of the pockets 31, which is slightly shorter than the length of
the side walls 33 of the pockets 31, and consequently the suction
members 24 `dip into` the pockets in the region between both side
walls 33 of the pocket to a depth 37'. Collisions can be prevented
in that recesses are provided in the side walls 33 of the pockets
31 and in the spring members 34 through which the suction members
24 can be guided.
[0046] The carton sleeves 10 are unfolded through the following
steps: Firstly a carton sleeve 10 is pushed out of the feeding
mechanism 13 through the opening 22 by the lug 20 of the finger 19.
There a suction member 24 of the transfer unit 14 adheres to the
carton sleeve 10 by suction and advances said sleeve along the
circular track 25. After approx. a third rotation of the drum 23
(angle of rotation of .phi.=120.degree.) the carton sleeve 10
approaches the conveyor belt 15 and the pocket 31 assigned thereto.
The transfer unit 14 and the conveyor belt 15 are arranged relative
to each other such that an edge 38 of the carton sleeve 10, lying
in the direction of rotation as seen from the front, abuts the
pocket 31 first. Technically speaking, a corner between the back
wall 32 and one of the side walls 33 of the pocket 31 serves as a
stop for the edge 38. As soon as the edge 38 of the carton sleeve
10 touches the pocket 31, forces (apart from centrifugal forces)
are only introduced to the carton sleeve 10 in two places: firstly,
in the region of the suction member 24, which channels the carton
sleeve 10, and secondly, on the front edge 38 of the carton sleeve
10. Both these places are spaced at a distance 39 apart. A specific
arrangement of the transfer unit 14 relative to the conveyor belt
15 and specific movement speeds and movement directions of transfer
unit 14 and conveyor belt 15 achieves the result that the distance
39 is continuously reduced during the insertion of the carton
sleeve 10 into the pocket 31. In this manner, two reciprocally
aligned forces 40, 41 are introduced to the carton sleeve 10, which
lead to the unfolding of the carton sleeve 10. The carton sleeves
10 are unfolded solely as a result of the effect of the suction
members 24 and the pocket 31 on the carton sleeve 10; separate
devices for unfolding are not, however, required.
[0047] Precise and sufficiently deep insertion of the carton
sleeves 10 into the pockets 31 is required for the type of
unfolding described. This happens successfully in spite of the
single rotational movement of the drum 23 due primarily to the fact
that the suction members 24 do not adhere to the carton sleeves 10
by suction centrally, but at a distance 42 from the centre thereof.
This distance 42 corresponds more or less to the sum total of the
travel 21 and the offset 28 and may, for example, be in the region
of between 0 cm and 6 cm, and more particularly, between 1 cm and 3
cm. In relation to the width of the carton sleeves 10, the distance
42 to the centre may be in the region of between 10% and 40% of the
width of the carton sleeves 10.
[0048] FIG. 3 shows a system 43 for filling cartons with foodstuffs
known from the prior art (EP 0 112 605 A2). The individual stations
of the system 43 are only shown schematically in FIG. 3 as FIG. 3
is only intended to serve as an illustration of a potential area of
application for a device 12 according to the invention for
unfolding carton sleeves 10. The carton sleeves 10 (not shown in
FIG. 3) are unfolded by a station 44 and transferred to the pockets
31 on the conveyor belt 15. The station 44 can be replaced by the
device 12 according to the invention. The system 43 comprises a
first carousel 45 in which the gable panels 9 of the carton sleeves
10 are pre-folded. The carton sleeves 10 then pass through a
station 46 in which the base panels 8 of the carton sleeves 10 are
pre-folded. After pre-folding, the base panels 8 of the carton
sleeves 10 are folded together and sealed at a station 47. The
conveyor belt 15 is then guided around a second carousel 48 in
which the carton sleeves 10 sealed on the bottom side are filled
with foodstuffs. At a further station 49, the gable panels 9 of the
carton sleeves 10 are folded together and sealed. The now filled
and sealed carton sleeves 10 are then removed from the pockets 31
of the conveyor belt 15 at a further station 50 and discharged from
the system 43.
LIST OF REFERENCE SIGNS
[0049] 1 Blank
[0050] 2 Folding line
[0051] 3, 4 Side panels
[0052] 5 Front panel
[0053] 6 Rear panel
[0054] 7 Sealing panel
[0055] 8 Base panel
[0056] 9 Gable panel
[0057] 10 Carton sleeve
[0058] 11 Longitudinal seam
[0059] 12 Device for unfolding carton sleeves
[0060] 13 Mechanism for providing carton sleeves
[0061] 14 Transfer unit
[0062] 15 Conveyor belt
[0063] 16 Housing
[0064] 17 Hopper
[0065] 18 Central plane
[0066] 19 Finger
[0067] 20 Lug
[0068] 21 Travel
[0069] 22 Opening
[0070] 23 Drum
[0071] 24 Suction member
[0072] 25 Circular track
[0073] 26 Distance
[0074] 27 Rotational axis
[0075] 28 Offset
[0076] 29 Plane
[0077] 30 Tangential plane
[0078] 31 Pocket
[0079] 32 Back wall
[0080] 33 Side wall
[0081] 34 Spring member
[0082] 35 End of spring member
[0083] 36 Distance between pockets
[0084] 37 Minimum distances
[0085] 37' Depth
[0086] 38 Edge of carton sleeve
[0087] 39 Distance
[0088] 40, 41 Forces
[0089] 42 Distance
[0090] 43 System
[0091] 44 Station (unfolding)
[0092] 45 Carousel (pre-folding of gable panels)
[0093] 46 Station (pre-folding base panels)
[0094] 47 Station (base sealing)
[0095] 48 Carousel (filling)
[0096] 49 Station (gable sealing)
[0097] 50 Station (discharging)
[0098] F Force
[0099] .omega. Angular velocity of the transfer unit
[0100] .phi. Angle of rotation of the transfer unit
[0101] v Speed of the conveyor belt
[0102] .alpha. Angle of inclination
* * * * *